TY  - JOUR
AU  - Vojvodić, Snežana
AU  - Dimitrijević, Milena
AU  - Žižić, Milan
AU  - Dučić, Tanja
AU  - AQUILANTI, Giuliana
AU  - Stanić, Marina
AU  - Zechmann, Bernd
AU  - Danilović Luković, Jelena
AU  - Stanković, Dalibor M.
AU  - Opačić, Miloš
AU  - Morina, Arian
AU  - Pittman, Jon K.
AU  - Spasojević, Ivan
PY  - 2023
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/2378
AB  - Metabolism of metals in microalgae and adaptation to metal excess are of significant environmental importance. We report a three-step mechanism that the green microalga Chlorella sorokiniana activates during the acquisition of and adaptation to manganese (Mn), which is both an essential trace metal and a pollutant of waters. In the early stage, Mn2+ was mainly bound to membrane phospholipids and phosphates in released mucilage. The outer cell wall
was reorganized and lipids were accumulated, with a relative increase in lipid saturation. Intracellular redox settings were rapidly altered in the presence of Mn excess, with increased production of reactive oxygen species that resulted in lipid peroxidation and a decrease in the concentration of thiols. In the later stage, Mn2+ was chelated by polyphosphates and accumulated in the cells. The structure of the inner cell wall was modified and the redox milieu established a new balance. Polyphosphates serve as a transient Mn2+ storage ligand, as proposed previously. In the final stage, Mn was stored in multivalent Mn clusters that resemble the structure of the tetramanganese–calcium core of the oxygen-evolving complex. The present findings elucidate the bioinorganic chemistry and metabolism of Mn in microalgae, and may shed new light on water-splitting Mn clusters.
PB  - Oxford University Press
T2  - Journal of Experimental Botany
T1  - A three-step process of manganese acquisition and storage in the microalga Chlorella sorokiniana
EP  - 1122
IS  - 3
SP  - 1107
VL  - 74
DO  - 10.1093/jxb/erac472
ER  - 

@article{
author = "Vojvodić, Snežana and Dimitrijević, Milena and Žižić, Milan and Dučić, Tanja and AQUILANTI, Giuliana and Stanić, Marina and Zechmann, Bernd and Danilović Luković, Jelena and Stanković, Dalibor M. and Opačić, Miloš and Morina, Arian and Pittman, Jon K. and Spasojević, Ivan",
year = "2023",
abstract = "Metabolism of metals in microalgae and adaptation to metal excess are of significant environmental importance. We report a three-step mechanism that the green microalga Chlorella sorokiniana activates during the acquisition of and adaptation to manganese (Mn), which is both an essential trace metal and a pollutant of waters. In the early stage, Mn2+ was mainly bound to membrane phospholipids and phosphates in released mucilage. The outer cell wall
was reorganized and lipids were accumulated, with a relative increase in lipid saturation. Intracellular redox settings were rapidly altered in the presence of Mn excess, with increased production of reactive oxygen species that resulted in lipid peroxidation and a decrease in the concentration of thiols. In the later stage, Mn2+ was chelated by polyphosphates and accumulated in the cells. The structure of the inner cell wall was modified and the redox milieu established a new balance. Polyphosphates serve as a transient Mn2+ storage ligand, as proposed previously. In the final stage, Mn was stored in multivalent Mn clusters that resemble the structure of the tetramanganese–calcium core of the oxygen-evolving complex. The present findings elucidate the bioinorganic chemistry and metabolism of Mn in microalgae, and may shed new light on water-splitting Mn clusters.",
publisher = "Oxford University Press",
journal = "Journal of Experimental Botany",
title = "A three-step process of manganese acquisition and storage in the microalga Chlorella sorokiniana",
pages = "1122-1107",
number = "3",
volume = "74",
doi = "10.1093/jxb/erac472"
}

Vojvodić, S., Dimitrijević, M., Žižić, M., Dučić, T., AQUILANTI, G., Stanić, M., Zechmann, B., Danilović Luković, J., Stanković, D. M., Opačić, M., Morina, A., Pittman, J. K.,& Spasojević, I.. (2023). A three-step process of manganese acquisition and storage in the microalga Chlorella sorokiniana. in Journal of Experimental Botany
Oxford University Press., 74(3), 1107-1122.
https://doi.org/10.1093/jxb/erac472

Vojvodić S, Dimitrijević M, Žižić M, Dučić T, AQUILANTI G, Stanić M, Zechmann B, Danilović Luković J, Stanković DM, Opačić M, Morina A, Pittman JK, Spasojević I. A three-step process of manganese acquisition and storage in the microalga Chlorella sorokiniana. in Journal of Experimental Botany. 2023;74(3):1107-1122.
doi:10.1093/jxb/erac472 .

Vojvodić, Snežana, Dimitrijević, Milena, Žižić, Milan, Dučić, Tanja, AQUILANTI, Giuliana, Stanić, Marina, Zechmann, Bernd, Danilović Luković, Jelena, Stanković, Dalibor M., Opačić, Miloš, Morina, Arian, Pittman, Jon K., Spasojević, Ivan, "A three-step process of manganese acquisition and storage in the microalga Chlorella sorokiniana" in Journal of Experimental Botany, 74, no. 3 (2023):1107-1122,
https://doi.org/10.1093/jxb/erac472 . .

TY  - CONF
AU  - Dimitrijević, Milena
AU  - Kovačević, Snežana
AU  - Jovanović, Uroš
AU  - Stanić, Marina
AU  - Opačić, Miloš
AU  - Santrač, Isidora
AU  - Tanović, Marija
AU  - Ćurić, Valentina
AU  - Spasojević, Ivan
PY  - 2023
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/2421
AB  - Heavy metals remain a major pollutant in waters near mining sites. Water pollution is a current, longterm problem that affects plants and organisms that live in these water systems, and the effect is very harmful not only for individual species and populations, but also for the entire biological community. This study analyzed the potential of the microalga Chlorella sorokiniana in the adsorption of four selected metals: Fe, Cu, Zn and Ni, all present in high amounts in Lake Robule. This pilot study was conducted to evaluate the potential of these microalgae for possible use in future bioremediation treatment of these water. A laboratory study of metal accumulation in lake water samples lasted for 7 days, after which a total decrease in metal concentration was observed, namely Fe ~25%, Cu ~17%, and Zn ~4% on the seventh day. This study confirms the strong potential of microalgae C. sorokiniana to reduce the presence of heavy metals in conditions known for the low pH value of water with a high percentage of Fe and other heavy metals.
PB  - University of Belgrade
PB  - Technical Faculty in Bor
C3  - 30th international conference ecological truth and environmental research – EcoTER’23. 20-23 June 2023, Mt Stara Planina, Serbia
T1  - Application of microalga Chlorella sorokiniana in wastewater bioremediation – case of lake Robule
EP  - 334
SP  - 330
UR  - https://hdl.handle.net/21.15107/rcub_rimsi_2421
ER  - 

@conference{
author = "Dimitrijević, Milena and Kovačević, Snežana and Jovanović, Uroš and Stanić, Marina and Opačić, Miloš and Santrač, Isidora and Tanović, Marija and Ćurić, Valentina and Spasojević, Ivan",
year = "2023",
abstract = "Heavy metals remain a major pollutant in waters near mining sites. Water pollution is a current, longterm problem that affects plants and organisms that live in these water systems, and the effect is very harmful not only for individual species and populations, but also for the entire biological community. This study analyzed the potential of the microalga Chlorella sorokiniana in the adsorption of four selected metals: Fe, Cu, Zn and Ni, all present in high amounts in Lake Robule. This pilot study was conducted to evaluate the potential of these microalgae for possible use in future bioremediation treatment of these water. A laboratory study of metal accumulation in lake water samples lasted for 7 days, after which a total decrease in metal concentration was observed, namely Fe ~25%, Cu ~17%, and Zn ~4% on the seventh day. This study confirms the strong potential of microalgae C. sorokiniana to reduce the presence of heavy metals in conditions known for the low pH value of water with a high percentage of Fe and other heavy metals.",
publisher = "University of Belgrade, Technical Faculty in Bor",
journal = "30th international conference ecological truth and environmental research – EcoTER’23. 20-23 June 2023, Mt Stara Planina, Serbia",
title = "Application of microalga Chlorella sorokiniana in wastewater bioremediation – case of lake Robule",
pages = "334-330",
url = "https://hdl.handle.net/21.15107/rcub_rimsi_2421"
}

Dimitrijević, M., Kovačević, S., Jovanović, U., Stanić, M., Opačić, M., Santrač, I., Tanović, M., Ćurić, V.,& Spasojević, I.. (2023). Application of microalga Chlorella sorokiniana in wastewater bioremediation – case of lake Robule. in 30th international conference ecological truth and environmental research – EcoTER’23. 20-23 June 2023, Mt Stara Planina, Serbia
University of Belgrade., 330-334.
https://hdl.handle.net/21.15107/rcub_rimsi_2421

Dimitrijević M, Kovačević S, Jovanović U, Stanić M, Opačić M, Santrač I, Tanović M, Ćurić V, Spasojević I. Application of microalga Chlorella sorokiniana in wastewater bioremediation – case of lake Robule. in 30th international conference ecological truth and environmental research – EcoTER’23. 20-23 June 2023, Mt Stara Planina, Serbia. 2023;:330-334.
https://hdl.handle.net/21.15107/rcub_rimsi_2421 .

Dimitrijević, Milena, Kovačević, Snežana, Jovanović, Uroš, Stanić, Marina, Opačić, Miloš, Santrač, Isidora, Tanović, Marija, Ćurić, Valentina, Spasojević, Ivan, "Application of microalga Chlorella sorokiniana in wastewater bioremediation – case of lake Robule" in 30th international conference ecological truth and environmental research – EcoTER’23. 20-23 June 2023, Mt Stara Planina, Serbia (2023):330-334,
https://hdl.handle.net/21.15107/rcub_rimsi_2421 .

TY  - CONF
AU  - Santrač, Isidora
AU  - Dimitrijević, Milena
AU  - Stanić, Marina
AU  - Tanović, Marija
AU  - Ćurić, Valentina
AU  - Kovačević, Snežana
AU  - Spasojević, Ivan
PY  - 2023
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/2416
AB  - Acid mine drainage ponds represents a specific artificial ecosystem that gives advantage to extemophilic microalgae. The mechanisms of adaptaton of such strains to excess metal concentrations that are common for their habitat, are poorly understood. Herein, we analzyed two strains of the green microalga Chlamydomonas acidophila - 137 and PM01, which have been isolated from different mining sites, for their interactions with Mn ions. The effects of different concentrations of Mn2+ were investigated in the late exponential/early stationary phase of culture growth (15 days). Viability was determined by Evans blue assay. No toxic effects were observed at concentrations as high as 2 mM Mn2+. The the time dynamics of Mn accumulation in the biomass was determined using ICP. It was shown that the maximum accumulation of Mn in strain 137 (3.79 ± 0.68 μg/mg) was reached at 24h, while for PM01 the highest uptake (3.23 ± 0.17 μg/mg) was observed at 72 h. Next we analyzed redox settings by measuring the levels of reduced thiols unsing in vivo EPR spin probing. The treatment with 2 mM Mn2+ induced a rapid and irreversible decrease in the level of thiols which indicates that Mn2+ activated prooxidtaive processes. The maximum drop of thios levels were: from 4.80 ± 0.05 to 2.70 ± 0.05nmol/mg fresh weight after 1h for 137; and from 4.70 ± 0.05 to 3.40 ± 0.05 nmol/mg fresh weiht after 30 min for PM01. Further, the level of reactive oxygen species was evaluated using fluorescent probe DCFH-DA assay. The changes were in agreement with thiol levels. Both tested algal strains show resistance to Mn and are therefore good candidates for application in water bioremediation.
PB  - Faculty of Chemistry, Serbian Biochemical Society
C3  - Serbian Biochemical Society Twelfth Conference, “Biochemistry in Biotechnology”, September 21-23, 2023, Belgrade, Serbia
T1  - The accumulation of manganese by Chlamydomonas acidophila strains isolated from acid mine drainage
EP  - 115
SP  - 115
UR  - https://hdl.handle.net/21.15107/rcub_rimsi_2416
ER  - 

@conference{
author = "Santrač, Isidora and Dimitrijević, Milena and Stanić, Marina and Tanović, Marija and Ćurić, Valentina and Kovačević, Snežana and Spasojević, Ivan",
year = "2023",
abstract = "Acid mine drainage ponds represents a specific artificial ecosystem that gives advantage to extemophilic microalgae. The mechanisms of adaptaton of such strains to excess metal concentrations that are common for their habitat, are poorly understood. Herein, we analzyed two strains of the green microalga Chlamydomonas acidophila - 137 and PM01, which have been isolated from different mining sites, for their interactions with Mn ions. The effects of different concentrations of Mn2+ were investigated in the late exponential/early stationary phase of culture growth (15 days). Viability was determined by Evans blue assay. No toxic effects were observed at concentrations as high as 2 mM Mn2+. The the time dynamics of Mn accumulation in the biomass was determined using ICP. It was shown that the maximum accumulation of Mn in strain 137 (3.79 ± 0.68 μg/mg) was reached at 24h, while for PM01 the highest uptake (3.23 ± 0.17 μg/mg) was observed at 72 h. Next we analyzed redox settings by measuring the levels of reduced thiols unsing in vivo EPR spin probing. The treatment with 2 mM Mn2+ induced a rapid and irreversible decrease in the level of thiols which indicates that Mn2+ activated prooxidtaive processes. The maximum drop of thios levels were: from 4.80 ± 0.05 to 2.70 ± 0.05nmol/mg fresh weight after 1h for 137; and from 4.70 ± 0.05 to 3.40 ± 0.05 nmol/mg fresh weiht after 30 min for PM01. Further, the level of reactive oxygen species was evaluated using fluorescent probe DCFH-DA assay. The changes were in agreement with thiol levels. Both tested algal strains show resistance to Mn and are therefore good candidates for application in water bioremediation.",
publisher = "Faculty of Chemistry, Serbian Biochemical Society",
journal = "Serbian Biochemical Society Twelfth Conference, “Biochemistry in Biotechnology”, September 21-23, 2023, Belgrade, Serbia",
title = "The accumulation of manganese by Chlamydomonas acidophila strains isolated from acid mine drainage",
pages = "115-115",
url = "https://hdl.handle.net/21.15107/rcub_rimsi_2416"
}

Santrač, I., Dimitrijević, M., Stanić, M., Tanović, M., Ćurić, V., Kovačević, S.,& Spasojević, I.. (2023). The accumulation of manganese by Chlamydomonas acidophila strains isolated from acid mine drainage. in Serbian Biochemical Society Twelfth Conference, “Biochemistry in Biotechnology”, September 21-23, 2023, Belgrade, Serbia
Faculty of Chemistry, Serbian Biochemical Society., 115-115.
https://hdl.handle.net/21.15107/rcub_rimsi_2416

Santrač I, Dimitrijević M, Stanić M, Tanović M, Ćurić V, Kovačević S, Spasojević I. The accumulation of manganese by Chlamydomonas acidophila strains isolated from acid mine drainage. in Serbian Biochemical Society Twelfth Conference, “Biochemistry in Biotechnology”, September 21-23, 2023, Belgrade, Serbia. 2023;:115-115.
https://hdl.handle.net/21.15107/rcub_rimsi_2416 .

Santrač, Isidora, Dimitrijević, Milena, Stanić, Marina, Tanović, Marija, Ćurić, Valentina, Kovačević, Snežana, Spasojević, Ivan, "The accumulation of manganese by Chlamydomonas acidophila strains isolated from acid mine drainage" in Serbian Biochemical Society Twelfth Conference, “Biochemistry in Biotechnology”, September 21-23, 2023, Belgrade, Serbia (2023):115-115,
https://hdl.handle.net/21.15107/rcub_rimsi_2416 .

TY  - CONF
AU  - Ćukić, Aleksandra
AU  - Dimitrijević, Milena
AU  - Kovačević, Snežana
AU  - Opačić, Miloš
AU  - Stanić, Marina
AU  - Žižić, Milan
AU  - Spasojević, Ivan
PY  - 2022
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/2419
AB  - Индустријализацијом и употребом фосилних горива, водени екосистеми су све више загађени тешким металима, укључујући и никл. Једноћелијске алге представљају значајне карике у процесу биоремедијације отпадних вода. Као стресор, никл доводи до стварања реактивних врста кисеоника (ROS) код зелених алги. Механизми за заштиту од ROS обухватају неензимске и ензимске антиоксидансе као што су глутатион, аскорбат, каротеноиди, супероксид дисмутазe (CuZnSOD, FeSOD и MnSOD), каталаза (CAT), глутатион пероксидаза и глутатион редуктаза. Циљ овог рада је био да се испитају нивои антиоксидативних ензима једноћелијске алге C. sorokiniana гајене у култури и излагане високој али нетоксичној концентрацији јона Ni(II) (1 mM) у трајању од 1 h и 24 h. Методом Western blot детектовани су нивои FeSOD, MnSOD и CAT у ћелијским екстрактима контролних и никлом третираних узорака микроалги. Тренд смањења нивоа FeSOD и MnSOD протеина уочен је након једносатног третмана никлом. Код третмана од 24 h ниво FeSOD остаје смањен, док се ниво MnSOD враћа на контролне вредности. Није било промена у нивоу CAT. Показано је да акутни стрес изазван 1 mM Ni(II), који укључује повећан ниво ROS (што је установљено одговарајућим есејима), не доводи до статистички значајних промена у нивоу испитиваних антиоксидативних ензима код C. sorokiniana. Потребно је испитати остале компоненте антиоксидативне заштите које вероватно учествују у уклањању ROS индукованих на овај начин.
PB  - Srpsko biološko društvo, Beograd, 2022
C3  - Treći kongres biologa Srbije, osnovna i primenjena istraživanja, metodika nastave. Zlatibor, Srbija 21 – 25. 9. 2022.
T1  - Uticaj povećane koncentracije jona Ni(II) na nivo antioksidativnih enzima u jednoćelijskoj algi Chlorella sorokiniana
EP  - 230
SP  - 230
UR  - https://hdl.handle.net/21.15107/rcub_rimsi_2419
ER  - 

@conference{
author = "Ćukić, Aleksandra and Dimitrijević, Milena and Kovačević, Snežana and Opačić, Miloš and Stanić, Marina and Žižić, Milan and Spasojević, Ivan",
year = "2022",
abstract = "Индустријализацијом и употребом фосилних горива, водени екосистеми су све више загађени тешким металима, укључујући и никл. Једноћелијске алге представљају значајне карике у процесу биоремедијације отпадних вода. Као стресор, никл доводи до стварања реактивних врста кисеоника (ROS) код зелених алги. Механизми за заштиту од ROS обухватају неензимске и ензимске антиоксидансе као што су глутатион, аскорбат, каротеноиди, супероксид дисмутазe (CuZnSOD, FeSOD и MnSOD), каталаза (CAT), глутатион пероксидаза и глутатион редуктаза. Циљ овог рада је био да се испитају нивои антиоксидативних ензима једноћелијске алге C. sorokiniana гајене у култури и излагане високој али нетоксичној концентрацији јона Ni(II) (1 mM) у трајању од 1 h и 24 h. Методом Western blot детектовани су нивои FeSOD, MnSOD и CAT у ћелијским екстрактима контролних и никлом третираних узорака микроалги. Тренд смањења нивоа FeSOD и MnSOD протеина уочен је након једносатног третмана никлом. Код третмана од 24 h ниво FeSOD остаје смањен, док се ниво MnSOD враћа на контролне вредности. Није било промена у нивоу CAT. Показано је да акутни стрес изазван 1 mM Ni(II), који укључује повећан ниво ROS (што је установљено одговарајућим есејима), не доводи до статистички значајних промена у нивоу испитиваних антиоксидативних ензима код C. sorokiniana. Потребно је испитати остале компоненте антиоксидативне заштите које вероватно учествују у уклањању ROS индукованих на овај начин.",
publisher = "Srpsko biološko društvo, Beograd, 2022",
journal = "Treći kongres biologa Srbije, osnovna i primenjena istraživanja, metodika nastave. Zlatibor, Srbija 21 – 25. 9. 2022.",
title = "Uticaj povećane koncentracije jona Ni(II) na nivo antioksidativnih enzima u jednoćelijskoj algi Chlorella sorokiniana",
pages = "230-230",
url = "https://hdl.handle.net/21.15107/rcub_rimsi_2419"
}

Ćukić, A., Dimitrijević, M., Kovačević, S., Opačić, M., Stanić, M., Žižić, M.,& Spasojević, I.. (2022). Uticaj povećane koncentracije jona Ni(II) na nivo antioksidativnih enzima u jednoćelijskoj algi Chlorella sorokiniana. in Treći kongres biologa Srbije, osnovna i primenjena istraživanja, metodika nastave. Zlatibor, Srbija 21 – 25. 9. 2022.
Srpsko biološko društvo, Beograd, 2022., 230-230.
https://hdl.handle.net/21.15107/rcub_rimsi_2419

Ćukić A, Dimitrijević M, Kovačević S, Opačić M, Stanić M, Žižić M, Spasojević I. Uticaj povećane koncentracije jona Ni(II) na nivo antioksidativnih enzima u jednoćelijskoj algi Chlorella sorokiniana. in Treći kongres biologa Srbije, osnovna i primenjena istraživanja, metodika nastave. Zlatibor, Srbija 21 – 25. 9. 2022.. 2022;:230-230.
https://hdl.handle.net/21.15107/rcub_rimsi_2419 .

Ćukić, Aleksandra, Dimitrijević, Milena, Kovačević, Snežana, Opačić, Miloš, Stanić, Marina, Žižić, Milan, Spasojević, Ivan, "Uticaj povećane koncentracije jona Ni(II) na nivo antioksidativnih enzima u jednoćelijskoj algi Chlorella sorokiniana" in Treći kongres biologa Srbije, osnovna i primenjena istraživanja, metodika nastave. Zlatibor, Srbija 21 – 25. 9. 2022. (2022):230-230,
https://hdl.handle.net/21.15107/rcub_rimsi_2419 .

TY  - CONF
AU  - Vojvodić, Snežana
AU  - Stanić, Marina
AU  - Danilović Luković, Jelena
AU  - Milivojević, Marija
AU  - Zechmann, Bernd
AU  - Dimitrijević, Milena
AU  - Opačić, Miloš
AU  - Pittman, Jon K.
AU  - Spasojević, Ivan
PY  - 2022
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/2403
AB  - METHODS
The impact of a set of concentrations of Mn2+ and Ni2+ on growth of C. sorokiniana culture in 3N-BBM+V
medium in the early stationary phase was evaluated by changes in optical density at 750 nm and biomass
during 7 days treatment. Mucilage release was analyzed using SEM microscopy. Redox settings were analyzed
by oxidation-sensitive fluorescent probe and assays for thiols.
RESULTS
Ni was more toxic than Mn and affected culture growth at lower concentrations. Microalgal cells started
releasing mucilage polymers within 1 h of exposure to 1 mM Mn2+, whereas no mucilage was observed even
at 24 h of treatment with equimolar Ni2+. The peak of reactive oxygen species production was reached faster
for Ni2+ than Mn2+. Mn-induced drops in the concentration of reduced thiols showed a recovery after 1 h and
24 h. Ni2+-induced drop was irreversible. The observed differences between the impact of Mn and Ni may be
related to different redox and coordinative properties and to higher capacities of microalgae to sequester Mn
in relation to higher quotas than Ni that are required for normal functio
C3  - FEMS Conference on Microbiology (in association with Serbian Society of Microbiology), Belgrade, Serbia.
T1  - Comparative impact of Mn2+ and Ni2+ on the microalga Chlorella sorokiniana
EP  - 748
SP  - 747
UR  - https://hdl.handle.net/21.15107/rcub_rimsi_2403
ER  - 

@conference{
author = "Vojvodić, Snežana and Stanić, Marina and Danilović Luković, Jelena and Milivojević, Marija and Zechmann, Bernd and Dimitrijević, Milena and Opačić, Miloš and Pittman, Jon K. and Spasojević, Ivan",
year = "2022",
abstract = "METHODS
The impact of a set of concentrations of Mn2+ and Ni2+ on growth of C. sorokiniana culture in 3N-BBM+V
medium in the early stationary phase was evaluated by changes in optical density at 750 nm and biomass
during 7 days treatment. Mucilage release was analyzed using SEM microscopy. Redox settings were analyzed
by oxidation-sensitive fluorescent probe and assays for thiols.
RESULTS
Ni was more toxic than Mn and affected culture growth at lower concentrations. Microalgal cells started
releasing mucilage polymers within 1 h of exposure to 1 mM Mn2+, whereas no mucilage was observed even
at 24 h of treatment with equimolar Ni2+. The peak of reactive oxygen species production was reached faster
for Ni2+ than Mn2+. Mn-induced drops in the concentration of reduced thiols showed a recovery after 1 h and
24 h. Ni2+-induced drop was irreversible. The observed differences between the impact of Mn and Ni may be
related to different redox and coordinative properties and to higher capacities of microalgae to sequester Mn
in relation to higher quotas than Ni that are required for normal functio",
journal = "FEMS Conference on Microbiology (in association with Serbian Society of Microbiology), Belgrade, Serbia.",
title = "Comparative impact of Mn2+ and Ni2+ on the microalga Chlorella sorokiniana",
pages = "748-747",
url = "https://hdl.handle.net/21.15107/rcub_rimsi_2403"
}

Vojvodić, S., Stanić, M., Danilović Luković, J., Milivojević, M., Zechmann, B., Dimitrijević, M., Opačić, M., Pittman, J. K.,& Spasojević, I.. (2022). Comparative impact of Mn2+ and Ni2+ on the microalga Chlorella sorokiniana. in FEMS Conference on Microbiology (in association with Serbian Society of Microbiology), Belgrade, Serbia., 747-748.
https://hdl.handle.net/21.15107/rcub_rimsi_2403

Vojvodić S, Stanić M, Danilović Luković J, Milivojević M, Zechmann B, Dimitrijević M, Opačić M, Pittman JK, Spasojević I. Comparative impact of Mn2+ and Ni2+ on the microalga Chlorella sorokiniana. in FEMS Conference on Microbiology (in association with Serbian Society of Microbiology), Belgrade, Serbia.. 2022;:747-748.
https://hdl.handle.net/21.15107/rcub_rimsi_2403 .

Vojvodić, Snežana, Stanić, Marina, Danilović Luković, Jelena, Milivojević, Marija, Zechmann, Bernd, Dimitrijević, Milena, Opačić, Miloš, Pittman, Jon K., Spasojević, Ivan, "Comparative impact of Mn2+ and Ni2+ on the microalga Chlorella sorokiniana" in FEMS Conference on Microbiology (in association with Serbian Society of Microbiology), Belgrade, Serbia. (2022):747-748,
https://hdl.handle.net/21.15107/rcub_rimsi_2403 .

TY  - CONF
AU  - Vojvodić, Snežana
AU  - Opačić, Miloš
AU  - Stanić, Marina
AU  - Dimitrijević, Milena
AU  - Pittman, Jon K.
AU  - Spasojević, Ivan
PY  - 2022
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/2417
AB  - Nickel is utilized by microalgae as a co-factor of urease. On the other hand, this transition metal represents an important pollutant of aquatic ecosystems. The effects of Ni(II) excess on microalgae and the mechanisms of adaptation are poorly understood. Redox processes represent an important component of the mechanisms of interaction of microalgae with transition metals. Pertinent to this, we analyzed redox changes in Chlorella sorokiniana culture that are induced by high levels of Ni(II). The intracellular level of reactive oxygen species (ROS) showed a rapid two-phase increase that took place prior to Ni accumulation in the cell. This was accompanied by oxidation of thiols and drastic deglutathyonilation of proteins. PAM fluorimetry showed that Ni excess induced an increase in the efficiency of photosystem II and promoted electron flow in chloroplasts, which is most likely responsible for ROS rise. In addition, a rising trend in the chlorophyll level was observed. On the other hand, the level of lipid peroxidation and activities of key antioxidative enzymes were not increased, which implies that oxidative stress is not an important player in Ni adaptation/toxicity. After prolonged exposure the efficiency of photosystem II drops, nickel is accumulated in the cells, and new redox balance is established. Our results imply that redox signalling is involved in Ni-induced metabolic activation and that key changes take place in photosynthetic machinery.
PB  - Faculty of Chemistry, Serbian Biochemical Society
C3  - Serbian Biochemical Society Eleventh Conference, “Amazing Biochemistry”. September 22nd and 23rd, 2022, Novi Sad, Serbia
T1  - Redox component in the adaptation of the microalga Chlorella sorokiniana to Ni(II) excess
EP  - 133
SP  - 133
UR  - https://hdl.handle.net/21.15107/rcub_rimsi_2417
ER  - 

@conference{
author = "Vojvodić, Snežana and Opačić, Miloš and Stanić, Marina and Dimitrijević, Milena and Pittman, Jon K. and Spasojević, Ivan",
year = "2022",
abstract = "Nickel is utilized by microalgae as a co-factor of urease. On the other hand, this transition metal represents an important pollutant of aquatic ecosystems. The effects of Ni(II) excess on microalgae and the mechanisms of adaptation are poorly understood. Redox processes represent an important component of the mechanisms of interaction of microalgae with transition metals. Pertinent to this, we analyzed redox changes in Chlorella sorokiniana culture that are induced by high levels of Ni(II). The intracellular level of reactive oxygen species (ROS) showed a rapid two-phase increase that took place prior to Ni accumulation in the cell. This was accompanied by oxidation of thiols and drastic deglutathyonilation of proteins. PAM fluorimetry showed that Ni excess induced an increase in the efficiency of photosystem II and promoted electron flow in chloroplasts, which is most likely responsible for ROS rise. In addition, a rising trend in the chlorophyll level was observed. On the other hand, the level of lipid peroxidation and activities of key antioxidative enzymes were not increased, which implies that oxidative stress is not an important player in Ni adaptation/toxicity. After prolonged exposure the efficiency of photosystem II drops, nickel is accumulated in the cells, and new redox balance is established. Our results imply that redox signalling is involved in Ni-induced metabolic activation and that key changes take place in photosynthetic machinery.",
publisher = "Faculty of Chemistry, Serbian Biochemical Society",
journal = "Serbian Biochemical Society Eleventh Conference, “Amazing Biochemistry”. September 22nd and 23rd, 2022, Novi Sad, Serbia",
title = "Redox component in the adaptation of the microalga Chlorella sorokiniana to Ni(II) excess",
pages = "133-133",
url = "https://hdl.handle.net/21.15107/rcub_rimsi_2417"
}

Vojvodić, S., Opačić, M., Stanić, M., Dimitrijević, M., Pittman, J. K.,& Spasojević, I.. (2022). Redox component in the adaptation of the microalga Chlorella sorokiniana to Ni(II) excess. in Serbian Biochemical Society Eleventh Conference, “Amazing Biochemistry”. September 22nd and 23rd, 2022, Novi Sad, Serbia
Faculty of Chemistry, Serbian Biochemical Society., 133-133.
https://hdl.handle.net/21.15107/rcub_rimsi_2417

Vojvodić S, Opačić M, Stanić M, Dimitrijević M, Pittman JK, Spasojević I. Redox component in the adaptation of the microalga Chlorella sorokiniana to Ni(II) excess. in Serbian Biochemical Society Eleventh Conference, “Amazing Biochemistry”. September 22nd and 23rd, 2022, Novi Sad, Serbia. 2022;:133-133.
https://hdl.handle.net/21.15107/rcub_rimsi_2417 .

Vojvodić, Snežana, Opačić, Miloš, Stanić, Marina, Dimitrijević, Milena, Pittman, Jon K., Spasojević, Ivan, "Redox component in the adaptation of the microalga Chlorella sorokiniana to Ni(II) excess" in Serbian Biochemical Society Eleventh Conference, “Amazing Biochemistry”. September 22nd and 23rd, 2022, Novi Sad, Serbia (2022):133-133,
https://hdl.handle.net/21.15107/rcub_rimsi_2417 .

TY  - CONF
AU  - Vojvodić, Snežana
AU  - Dimitrijević, Milena
AU  - Dučić, Tanja
AU  - Stanković, Dalibor
AU  - Opačić, Miloš
AU  - Stanić, Marina
AU  - Žižić, Milan
AU  - Spasojević, Ivan
PY  - 2021
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/2391
AB  - Microalgae can be implemented in the remediation of mining and other metal-rich wastewaters as pioneer species. On the other hand, metals affect aquatic ecosystems through the negative impact on microalgae which are the primary producers of O2 and biomass. Redox processes represent an important component of the mechanisms of interaction of microalgae with transition metals. We analyzed the redox changes in Chlorella sorokiniana culture that are induced by high levels of Mn(II). Mn is the key metal pollutant, with five main oxidation forms that can bind to a variety of different ligands. Mn (1 mM) induced a significant increase in the intracellular production of reactive oxygen species. The boost appears to show two phases – the first is very fast (observed after 15 min), whereas the second starts after 1 h reaching a plateau at 24 h. The concentration of reduced thiols, which represent important targets of oxidation, appears to parallel this trend. Total glutathione concentration shows a drop at 1 h and recovery at 24 h. This implicates that either a glutathionylation of proteins or a synthesis of phytochelatins - sulfur-rich short-chain peptides that sequester metals, takes place early in the response to Mn. Further, FTIR analysis showed that Mn induced a decrease of C=C levels and CH2/CH3 ratio implicating increased lipid peroxidation. Finally, Mn ions that were accumulated in the cells were extracted with nitric oxide and analyzed by cyclic voltammetry. Two redox forms were detected - Mn(II) and Mn(IV). The latter appears to prevail at higher manganese concentrations and longer periods of incubation. These results demonstrate that redox response of C. sorokiniana to high Mn levels involves at least two phases. Initially, Mn(II) enters the cells and induces pro-oxidative changes that are mitigated by glutathione-based antioxidative defense. Later on, redox homeostasis is reestablished with concomitant inactivation of Mn in the more stable redox form.
PB  - Faculty of Chemistry, Serbian Biochemical Society
C3  - Serbian Biochemical Society Tenth Conference, “Biochemical Insights into Molecular Mechanisms”. 24.09.2021. Kragujevac, Serbia
T1  - Redox changes in microalga Chlorella sorokiniana exposed to high concentrations of Mn(II)
EP  - 174
SP  - 174
UR  - https://hdl.handle.net/21.15107/rcub_rimsi_2391
ER  - 

@conference{
author = "Vojvodić, Snežana and Dimitrijević, Milena and Dučić, Tanja and Stanković, Dalibor and Opačić, Miloš and Stanić, Marina and Žižić, Milan and Spasojević, Ivan",
year = "2021",
abstract = "Microalgae can be implemented in the remediation of mining and other metal-rich wastewaters as pioneer species. On the other hand, metals affect aquatic ecosystems through the negative impact on microalgae which are the primary producers of O2 and biomass. Redox processes represent an important component of the mechanisms of interaction of microalgae with transition metals. We analyzed the redox changes in Chlorella sorokiniana culture that are induced by high levels of Mn(II). Mn is the key metal pollutant, with five main oxidation forms that can bind to a variety of different ligands. Mn (1 mM) induced a significant increase in the intracellular production of reactive oxygen species. The boost appears to show two phases – the first is very fast (observed after 15 min), whereas the second starts after 1 h reaching a plateau at 24 h. The concentration of reduced thiols, which represent important targets of oxidation, appears to parallel this trend. Total glutathione concentration shows a drop at 1 h and recovery at 24 h. This implicates that either a glutathionylation of proteins or a synthesis of phytochelatins - sulfur-rich short-chain peptides that sequester metals, takes place early in the response to Mn. Further, FTIR analysis showed that Mn induced a decrease of C=C levels and CH2/CH3 ratio implicating increased lipid peroxidation. Finally, Mn ions that were accumulated in the cells were extracted with nitric oxide and analyzed by cyclic voltammetry. Two redox forms were detected - Mn(II) and Mn(IV). The latter appears to prevail at higher manganese concentrations and longer periods of incubation. These results demonstrate that redox response of C. sorokiniana to high Mn levels involves at least two phases. Initially, Mn(II) enters the cells and induces pro-oxidative changes that are mitigated by glutathione-based antioxidative defense. Later on, redox homeostasis is reestablished with concomitant inactivation of Mn in the more stable redox form.",
publisher = "Faculty of Chemistry, Serbian Biochemical Society",
journal = "Serbian Biochemical Society Tenth Conference, “Biochemical Insights into Molecular Mechanisms”. 24.09.2021. Kragujevac, Serbia",
title = "Redox changes in microalga Chlorella sorokiniana exposed to high concentrations of Mn(II)",
pages = "174-174",
url = "https://hdl.handle.net/21.15107/rcub_rimsi_2391"
}

Vojvodić, S., Dimitrijević, M., Dučić, T., Stanković, D., Opačić, M., Stanić, M., Žižić, M.,& Spasojević, I.. (2021). Redox changes in microalga Chlorella sorokiniana exposed to high concentrations of Mn(II). in Serbian Biochemical Society Tenth Conference, “Biochemical Insights into Molecular Mechanisms”. 24.09.2021. Kragujevac, Serbia
Faculty of Chemistry, Serbian Biochemical Society., 174-174.
https://hdl.handle.net/21.15107/rcub_rimsi_2391

Vojvodić S, Dimitrijević M, Dučić T, Stanković D, Opačić M, Stanić M, Žižić M, Spasojević I. Redox changes in microalga Chlorella sorokiniana exposed to high concentrations of Mn(II). in Serbian Biochemical Society Tenth Conference, “Biochemical Insights into Molecular Mechanisms”. 24.09.2021. Kragujevac, Serbia. 2021;:174-174.
https://hdl.handle.net/21.15107/rcub_rimsi_2391 .

Vojvodić, Snežana, Dimitrijević, Milena, Dučić, Tanja, Stanković, Dalibor, Opačić, Miloš, Stanić, Marina, Žižić, Milan, Spasojević, Ivan, "Redox changes in microalga Chlorella sorokiniana exposed to high concentrations of Mn(II)" in Serbian Biochemical Society Tenth Conference, “Biochemical Insights into Molecular Mechanisms”. 24.09.2021. Kragujevac, Serbia (2021):174-174,
https://hdl.handle.net/21.15107/rcub_rimsi_2391 .

TY  - CONF
AU  - Vojvodić, Snežana
AU  - Stanić, Marina
AU  - Zechmann, Bernd
AU  - Dimitrijević, Milena
AU  - Opačić, Miloš
AU  - Danilović Luković, Jelena
AU  - Morina, Arian
AU  - Pittman, Jon K.
AU  - Spasojević, Ivan
PY  - 2021
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/2420
AB  - Many neutrophilic and acidophilic microalgal species tolerate high metal concentrations
and can survive or colonize metal-polluted waters. They show significant biotechnological
potential for the remediation and wastewaters processing. On the other hand, negative effects
of metal pollution on microalgae may affect the function of aquatic ecosystems because these
photosynthetic microorganisms represent the primary producers of O2 and biomass. However,
adaptive mechanisms that microalgae employ to detoxify metal excess are largely unknown.
Herein we analyzed the response of the freshwater microalga Chlorella sorokiniana to high
but non-toxic levels of Mn2+. Manganese is a key metal pollutant, with five possible oxidation
forms that can bind to a variety of different ligands. At pH below 7, it is predominantly present in
Mn2+ form. Scanning electron microscopy showed that in response to 1 mM Mn2+, C. sorokiniana
released mucilage polymers within 1 h. Electron paramagnetic resonance spectroscopy (EPR)
showed that the early response involved loose Mn2+ binding to mucilage and/or the cell wall.
The amount of loosely bound Mn2+ was significantly decreased after 24 h, whereas biomass
showed significant accumulation of Mn, O and P, as determined by energy dispersive X-ray
spectrometry, indicating the production of polyphosphates, which may sequester Mn. Further,
it was found that the exposure to Mn2+ resulted in rapid and transient decrease of total free
glutathione concentration; the drop was observed after 1 h, and the concentration returned to
initial values after 24 h. EPR measurements showed a similar trend in the level of reduced thiols.
The observed changes can be explained either by the synthesis of phytochelatins – sulfurrich
short-chain peptides that sequester metals, or by glutathionylation of proteins. Reduced
thiols could not be detected in the extracellular space, indicating that C. sorokiniana did not
release thiols in response to high Mn. These results demonstrate that the adaptive response
of C. sorokiniana to high Mn levels involves multiple components and time phases. The early
phase involves mucilage release, phytochelatins and/or protection of protein thiols, whereas
the successive phase involves Mn coordination by polyphosphates and other mechanisms that
remain to be resolved.
PB  - Elsevier
PB  - Society for Free Radical Research Europe (SFRR-E)
PB  - Ministry of Education, Science and Technological Development (Republic of Serbia)
PB  - Oxygen Club of California
C3  - Redox Biology in the 21st Century: A New Scientific Discipline, Meeting Abstracts
T1  - Mechanisms of detoxification of high manganese concentrations by the microalga Chlorella sorokiniana
EP  - 145
SP  - 145
DO  - 10.1016/j.freeradbiomed.2021.08.148
ER  - 

@conference{
author = "Vojvodić, Snežana and Stanić, Marina and Zechmann, Bernd and Dimitrijević, Milena and Opačić, Miloš and Danilović Luković, Jelena and Morina, Arian and Pittman, Jon K. and Spasojević, Ivan",
year = "2021",
abstract = "Many neutrophilic and acidophilic microalgal species tolerate high metal concentrations
and can survive or colonize metal-polluted waters. They show significant biotechnological
potential for the remediation and wastewaters processing. On the other hand, negative effects
of metal pollution on microalgae may affect the function of aquatic ecosystems because these
photosynthetic microorganisms represent the primary producers of O2 and biomass. However,
adaptive mechanisms that microalgae employ to detoxify metal excess are largely unknown.
Herein we analyzed the response of the freshwater microalga Chlorella sorokiniana to high
but non-toxic levels of Mn2+. Manganese is a key metal pollutant, with five possible oxidation
forms that can bind to a variety of different ligands. At pH below 7, it is predominantly present in
Mn2+ form. Scanning electron microscopy showed that in response to 1 mM Mn2+, C. sorokiniana
released mucilage polymers within 1 h. Electron paramagnetic resonance spectroscopy (EPR)
showed that the early response involved loose Mn2+ binding to mucilage and/or the cell wall.
The amount of loosely bound Mn2+ was significantly decreased after 24 h, whereas biomass
showed significant accumulation of Mn, O and P, as determined by energy dispersive X-ray
spectrometry, indicating the production of polyphosphates, which may sequester Mn. Further,
it was found that the exposure to Mn2+ resulted in rapid and transient decrease of total free
glutathione concentration; the drop was observed after 1 h, and the concentration returned to
initial values after 24 h. EPR measurements showed a similar trend in the level of reduced thiols.
The observed changes can be explained either by the synthesis of phytochelatins – sulfurrich
short-chain peptides that sequester metals, or by glutathionylation of proteins. Reduced
thiols could not be detected in the extracellular space, indicating that C. sorokiniana did not
release thiols in response to high Mn. These results demonstrate that the adaptive response
of C. sorokiniana to high Mn levels involves multiple components and time phases. The early
phase involves mucilage release, phytochelatins and/or protection of protein thiols, whereas
the successive phase involves Mn coordination by polyphosphates and other mechanisms that
remain to be resolved.",
publisher = "Elsevier, Society for Free Radical Research Europe (SFRR-E), Ministry of Education, Science and Technological Development (Republic of Serbia), Oxygen Club of California",
journal = "Redox Biology in the 21st Century: A New Scientific Discipline, Meeting Abstracts",
title = "Mechanisms of detoxification of high manganese concentrations by the microalga Chlorella sorokiniana",
pages = "145-145",
doi = "10.1016/j.freeradbiomed.2021.08.148"
}

Vojvodić, S., Stanić, M., Zechmann, B., Dimitrijević, M., Opačić, M., Danilović Luković, J., Morina, A., Pittman, J. K.,& Spasojević, I.. (2021). Mechanisms of detoxification of high manganese concentrations by the microalga Chlorella sorokiniana. in Redox Biology in the 21st Century: A New Scientific Discipline, Meeting Abstracts
Elsevier., 145-145.
https://doi.org/10.1016/j.freeradbiomed.2021.08.148

Vojvodić S, Stanić M, Zechmann B, Dimitrijević M, Opačić M, Danilović Luković J, Morina A, Pittman JK, Spasojević I. Mechanisms of detoxification of high manganese concentrations by the microalga Chlorella sorokiniana. in Redox Biology in the 21st Century: A New Scientific Discipline, Meeting Abstracts. 2021;:145-145.
doi:10.1016/j.freeradbiomed.2021.08.148 .

Vojvodić, Snežana, Stanić, Marina, Zechmann, Bernd, Dimitrijević, Milena, Opačić, Miloš, Danilović Luković, Jelena, Morina, Arian, Pittman, Jon K., Spasojević, Ivan, "Mechanisms of detoxification of high manganese concentrations by the microalga Chlorella sorokiniana" in Redox Biology in the 21st Century: A New Scientific Discipline, Meeting Abstracts (2021):145-145,
https://doi.org/10.1016/j.freeradbiomed.2021.08.148 . .

TY  - CONF
AU  - Dimitrijević, Milena
AU  - Vojvodić, Snežana
AU  - Opačić, Miloš
AU  - Danilović Luković, Jelena
AU  - Milić, Jelena
AU  - Stanić, Marina
AU  - Spasojević, Ivan
PY  - 2021
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/2392
AB  - Microalgae show significant biotechnological potential for remediation of wastewaters polluted with metals, including nickel. Ni enters aquatic ecosystems from fuel combustion, smelting, mining, and electroplating endeavors, and represents a particularly important problem for the access to safe drinking water. It is noteworthy that microalgae utilize Ni as a co-factor of urease. Herein we analyzed the impact of high levels of Ni(II) on freshwater microalga Chlorella sorokiniana in the stationary phase of culture growth. In the concentration range 0.5 to 30 mM, Ni induced a drop in cell density and biomass after 7 days of incubation, whereas significant negative impact was present as early as 2 days for 30 mM. High concentrations also induced a decrease in the level of chlorophylls (a and b) in biomass. In contrast, microalgae that were exposed to moderate stress (1 and 2 mM of Ni) appear to increase photosynthetic activity, indicating the activation of some adaptive mechanism. Scanning electron microscopy showed that C. sorokiniana does not release significant amounts of mucilage polymers in response to Ni, in contrast to the response to some other metals 3. Further, Ni at 1 mM induced an increase in the intracellular production of reactive oxygen species, which appears to reach a plateau after 1 h. The concentration of free thiol groups showed a gradual drop during 24 h of incubation with the same Ni concentration. On the other hand, the decrease in the concentration of reduced glutathione that was observed after 1 h was reversible for 1 mM Ni at 24 h. Ni at 5 mM had a more lasting impact on glutathione. It is important to stress out that the concentrations of reduced glutathione and total glutathione showed very similar trends. This implies that free thiols and reduced glutathione may be ‘lost’ due to glutathionylation of proteins and synthesis of phytochelatins. Our results demonstrate that the response of C. sorokiniana to high Ni levels involves multiple components that may be different than for other metals. Redox regulation and protection of thiol (switches) may represent a crossroad between adaptation and death.
PB  - Faculty of Chemistry, Serbian Biochemical Society
C3  - Serbian Biochemical Society Tenth Conference, “Biochemical Insights into Molecular Mechanisms”. 24.09.2021. Kragujevac, Serbia
T1  - The effect of increased nickel concentrations on Chlorella sorokiniana culture
EP  - 58
SP  - 57
UR  - https://hdl.handle.net/21.15107/rcub_rimsi_2392
ER  - 

@conference{
author = "Dimitrijević, Milena and Vojvodić, Snežana and Opačić, Miloš and Danilović Luković, Jelena and Milić, Jelena and Stanić, Marina and Spasojević, Ivan",
year = "2021",
abstract = "Microalgae show significant biotechnological potential for remediation of wastewaters polluted with metals, including nickel. Ni enters aquatic ecosystems from fuel combustion, smelting, mining, and electroplating endeavors, and represents a particularly important problem for the access to safe drinking water. It is noteworthy that microalgae utilize Ni as a co-factor of urease. Herein we analyzed the impact of high levels of Ni(II) on freshwater microalga Chlorella sorokiniana in the stationary phase of culture growth. In the concentration range 0.5 to 30 mM, Ni induced a drop in cell density and biomass after 7 days of incubation, whereas significant negative impact was present as early as 2 days for 30 mM. High concentrations also induced a decrease in the level of chlorophylls (a and b) in biomass. In contrast, microalgae that were exposed to moderate stress (1 and 2 mM of Ni) appear to increase photosynthetic activity, indicating the activation of some adaptive mechanism. Scanning electron microscopy showed that C. sorokiniana does not release significant amounts of mucilage polymers in response to Ni, in contrast to the response to some other metals 3. Further, Ni at 1 mM induced an increase in the intracellular production of reactive oxygen species, which appears to reach a plateau after 1 h. The concentration of free thiol groups showed a gradual drop during 24 h of incubation with the same Ni concentration. On the other hand, the decrease in the concentration of reduced glutathione that was observed after 1 h was reversible for 1 mM Ni at 24 h. Ni at 5 mM had a more lasting impact on glutathione. It is important to stress out that the concentrations of reduced glutathione and total glutathione showed very similar trends. This implies that free thiols and reduced glutathione may be ‘lost’ due to glutathionylation of proteins and synthesis of phytochelatins. Our results demonstrate that the response of C. sorokiniana to high Ni levels involves multiple components that may be different than for other metals. Redox regulation and protection of thiol (switches) may represent a crossroad between adaptation and death.",
publisher = "Faculty of Chemistry, Serbian Biochemical Society",
journal = "Serbian Biochemical Society Tenth Conference, “Biochemical Insights into Molecular Mechanisms”. 24.09.2021. Kragujevac, Serbia",
title = "The effect of increased nickel concentrations on Chlorella sorokiniana culture",
pages = "58-57",
url = "https://hdl.handle.net/21.15107/rcub_rimsi_2392"
}

Dimitrijević, M., Vojvodić, S., Opačić, M., Danilović Luković, J., Milić, J., Stanić, M.,& Spasojević, I.. (2021). The effect of increased nickel concentrations on Chlorella sorokiniana culture. in Serbian Biochemical Society Tenth Conference, “Biochemical Insights into Molecular Mechanisms”. 24.09.2021. Kragujevac, Serbia
Faculty of Chemistry, Serbian Biochemical Society., 57-58.
https://hdl.handle.net/21.15107/rcub_rimsi_2392

Dimitrijević M, Vojvodić S, Opačić M, Danilović Luković J, Milić J, Stanić M, Spasojević I. The effect of increased nickel concentrations on Chlorella sorokiniana culture. in Serbian Biochemical Society Tenth Conference, “Biochemical Insights into Molecular Mechanisms”. 24.09.2021. Kragujevac, Serbia. 2021;:57-58.
https://hdl.handle.net/21.15107/rcub_rimsi_2392 .

Dimitrijević, Milena, Vojvodić, Snežana, Opačić, Miloš, Danilović Luković, Jelena, Milić, Jelena, Stanić, Marina, Spasojević, Ivan, "The effect of increased nickel concentrations on Chlorella sorokiniana culture" in Serbian Biochemical Society Tenth Conference, “Biochemical Insights into Molecular Mechanisms”. 24.09.2021. Kragujevac, Serbia (2021):57-58,
https://hdl.handle.net/21.15107/rcub_rimsi_2392 .

TY  - JOUR
AU  - Vojvodić, Snežana
AU  - Stanić, Marina
AU  - Zechmann, Bernd
AU  - Ducic, Tanja
AU  - Žižić, Milan
AU  - Dimitrijević, Milena
AU  - Danilović Luković, Jelena
AU  - Milenković, Milica R.
AU  - Pittman, Jon K.
AU  - Spasojević, Ivan
PY  - 2020
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1354
AB  - Microalgae have evolved mechanisms to respond to changes in copper ion availability, which are very important for normal cellular function, to tolerate metal pollution of aquatic ecosystems, and for modulation of copper bioavailability and toxicity to other organisms. Knowledge and application of these mechanisms will benefit the use of microalgae in wastewater processing and biomass production, and the use of copper compounds in the suppression of harmful algal blooms. Here, using electron microscopy, synchrotron radiation-based Fourier transform infrared spectroscopy, electron paramagnetic resonance spectroscopy, and X-ray absorption fine structure spectroscopy, we show that the microalga Chlorella sorokiniana responds promptly to Cu2+ at high non-toxic concentration, by mucilage release, alterations in the architecture of the outer cell wall layer and lipid structures, and polyphosphate accumulation within mucilage matrix. The main route of copper detoxification is by Cu2+ coordination to polyphosphates in penta-coordinated geometry. The sequestrated Cu2+ was accessible and could be released by extracellular chelating agents. Finally, the reduction in Cu2+ to Cu1+ appears also to take place. These findings reveal the biochemical basis of the capacity of microalgae to adapt to high external copper concentrations and to serve as both, sinks and pools of environmental copper.
PB  - Portland Press Ltd, London
T2  - Biochemical Journal
T1  - Mechanisms of detoxification of high copper concentrations by the microalga Chlorella sorokiniana
EP  - 3741
IS  - 19
SP  - 3729
VL  - 477
DO  - 10.1042/BCJ20200600
ER  - 

@article{
author = "Vojvodić, Snežana and Stanić, Marina and Zechmann, Bernd and Ducic, Tanja and Žižić, Milan and Dimitrijević, Milena and Danilović Luković, Jelena and Milenković, Milica R. and Pittman, Jon K. and Spasojević, Ivan",
year = "2020",
abstract = "Microalgae have evolved mechanisms to respond to changes in copper ion availability, which are very important for normal cellular function, to tolerate metal pollution of aquatic ecosystems, and for modulation of copper bioavailability and toxicity to other organisms. Knowledge and application of these mechanisms will benefit the use of microalgae in wastewater processing and biomass production, and the use of copper compounds in the suppression of harmful algal blooms. Here, using electron microscopy, synchrotron radiation-based Fourier transform infrared spectroscopy, electron paramagnetic resonance spectroscopy, and X-ray absorption fine structure spectroscopy, we show that the microalga Chlorella sorokiniana responds promptly to Cu2+ at high non-toxic concentration, by mucilage release, alterations in the architecture of the outer cell wall layer and lipid structures, and polyphosphate accumulation within mucilage matrix. The main route of copper detoxification is by Cu2+ coordination to polyphosphates in penta-coordinated geometry. The sequestrated Cu2+ was accessible and could be released by extracellular chelating agents. Finally, the reduction in Cu2+ to Cu1+ appears also to take place. These findings reveal the biochemical basis of the capacity of microalgae to adapt to high external copper concentrations and to serve as both, sinks and pools of environmental copper.",
publisher = "Portland Press Ltd, London",
journal = "Biochemical Journal",
title = "Mechanisms of detoxification of high copper concentrations by the microalga Chlorella sorokiniana",
pages = "3741-3729",
number = "19",
volume = "477",
doi = "10.1042/BCJ20200600"
}

Vojvodić, S., Stanić, M., Zechmann, B., Ducic, T., Žižić, M., Dimitrijević, M., Danilović Luković, J., Milenković, M. R., Pittman, J. K.,& Spasojević, I.. (2020). Mechanisms of detoxification of high copper concentrations by the microalga Chlorella sorokiniana. in Biochemical Journal
Portland Press Ltd, London., 477(19), 3729-3741.
https://doi.org/10.1042/BCJ20200600

Vojvodić S, Stanić M, Zechmann B, Ducic T, Žižić M, Dimitrijević M, Danilović Luković J, Milenković MR, Pittman JK, Spasojević I. Mechanisms of detoxification of high copper concentrations by the microalga Chlorella sorokiniana. in Biochemical Journal. 2020;477(19):3729-3741.
doi:10.1042/BCJ20200600 .

Vojvodić, Snežana, Stanić, Marina, Zechmann, Bernd, Ducic, Tanja, Žižić, Milan, Dimitrijević, Milena, Danilović Luković, Jelena, Milenković, Milica R., Pittman, Jon K., Spasojević, Ivan, "Mechanisms of detoxification of high copper concentrations by the microalga Chlorella sorokiniana" in Biochemical Journal, 477, no. 19 (2020):3729-3741,
https://doi.org/10.1042/BCJ20200600 . .

TY  - JOUR
AU  - Vojvodić, Snežana
AU  - Danilović Luković, Jelena
AU  - Zechmann, Bernd
AU  - Jevtović, Mima
AU  - Bogdanović Pristov, Jelena
AU  - Stanić, Marina
AU  - Lizzul, Alessandro Marco
AU  - Pittman, Jon K.
AU  - Spasojević, Ivan
PY  - 2020
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1371
AB  - The impact of ionizing radiation on microorganisms such as microalgae is a topic of increasing importance for understanding the dynamics of aquatic ecosystems in response to environmental radiation, and for the development of efficient approaches for bioremediation of mining and nuclear power plants wastewaters. Currently, nothing is known about the effects of ionizing radiation on the microalgal cell wall, which represents the first line of defence against chemical and physical environmental stresses. Using various microscopy, spectroscopy and biochemical techniques we show that the unicellular alga Chlorella sorokiniana elicits a fast response to ionizing radiation. Within one day after irradiation with doses of 1-5 Gy, the fibrilar layer of the cell wall became thicker, the fraction of uronic acids was higher, and the capacity to remove the main reactive product of water radiolysis increased. In addition, the isolated cell wall fraction showed significant binding capacity for Cu2+, Mn2+, and Cr3+. The irradiation further increased the binding capacity for Cu2+, which appears to be mainly bound to glucosamine moieties within a chitosan-like polymer in the outer rigid layer of the wall. These results imply that the cell wall represents a dynamic structure that is involved in the protective response of microalgae to ionizing radiation. It appears that microalgae may exhibit a significant control of metal mobility in aquatic ecosystems via biosorption by the cell wall matrix.
PB  - Pergamon-Elsevier Science Ltd, Oxford
T2  - Chemosphere
T1  - The effects of ionizing radiation on the structure and antioxidative and metal-binding capacity of the cell wall of microalga Chlorella sorokiniana
VL  - 260
DO  - 10.1016/j.chemosphere.2020.127553
ER  - 

@article{
author = "Vojvodić, Snežana and Danilović Luković, Jelena and Zechmann, Bernd and Jevtović, Mima and Bogdanović Pristov, Jelena and Stanić, Marina and Lizzul, Alessandro Marco and Pittman, Jon K. and Spasojević, Ivan",
year = "2020",
abstract = "The impact of ionizing radiation on microorganisms such as microalgae is a topic of increasing importance for understanding the dynamics of aquatic ecosystems in response to environmental radiation, and for the development of efficient approaches for bioremediation of mining and nuclear power plants wastewaters. Currently, nothing is known about the effects of ionizing radiation on the microalgal cell wall, which represents the first line of defence against chemical and physical environmental stresses. Using various microscopy, spectroscopy and biochemical techniques we show that the unicellular alga Chlorella sorokiniana elicits a fast response to ionizing radiation. Within one day after irradiation with doses of 1-5 Gy, the fibrilar layer of the cell wall became thicker, the fraction of uronic acids was higher, and the capacity to remove the main reactive product of water radiolysis increased. In addition, the isolated cell wall fraction showed significant binding capacity for Cu2+, Mn2+, and Cr3+. The irradiation further increased the binding capacity for Cu2+, which appears to be mainly bound to glucosamine moieties within a chitosan-like polymer in the outer rigid layer of the wall. These results imply that the cell wall represents a dynamic structure that is involved in the protective response of microalgae to ionizing radiation. It appears that microalgae may exhibit a significant control of metal mobility in aquatic ecosystems via biosorption by the cell wall matrix.",
publisher = "Pergamon-Elsevier Science Ltd, Oxford",
journal = "Chemosphere",
title = "The effects of ionizing radiation on the structure and antioxidative and metal-binding capacity of the cell wall of microalga Chlorella sorokiniana",
volume = "260",
doi = "10.1016/j.chemosphere.2020.127553"
}

Vojvodić, S., Danilović Luković, J., Zechmann, B., Jevtović, M., Bogdanović Pristov, J., Stanić, M., Lizzul, A. M., Pittman, J. K.,& Spasojević, I.. (2020). The effects of ionizing radiation on the structure and antioxidative and metal-binding capacity of the cell wall of microalga Chlorella sorokiniana. in Chemosphere
Pergamon-Elsevier Science Ltd, Oxford., 260.
https://doi.org/10.1016/j.chemosphere.2020.127553

Vojvodić S, Danilović Luković J, Zechmann B, Jevtović M, Bogdanović Pristov J, Stanić M, Lizzul AM, Pittman JK, Spasojević I. The effects of ionizing radiation on the structure and antioxidative and metal-binding capacity of the cell wall of microalga Chlorella sorokiniana. in Chemosphere. 2020;260.
doi:10.1016/j.chemosphere.2020.127553 .

Vojvodić, Snežana, Danilović Luković, Jelena, Zechmann, Bernd, Jevtović, Mima, Bogdanović Pristov, Jelena, Stanić, Marina, Lizzul, Alessandro Marco, Pittman, Jon K., Spasojević, Ivan, "The effects of ionizing radiation on the structure and antioxidative and metal-binding capacity of the cell wall of microalga Chlorella sorokiniana" in Chemosphere, 260 (2020),
https://doi.org/10.1016/j.chemosphere.2020.127553 . .

TY  - CONF
AU  - Danilović Luković, Jelena
AU  - Zechmann, Bernd
AU  - Vojvodić, Snežana
AU  - Bogdanović Pristov, Jelena
AU  - Stanić, Marina
AU  - Pittman, Jon K.
AU  - Spasojević, Ivan
PY  - 2019
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/2408
AB  - Cell wall of C. sorokiniana is composed of trilaminar sheath (TLS electron
translucent line inserted between two electron dense lines; the outermost layer is a mature mother
wall, while the thin inner layer is a daughter wall), and fibrilar cell wall. It is noteworthy that the
obtained diameters for untreated microalgae were in accordance with available data. The analysis of TEM micrographs showed that there were no significant changes in the thickness of
TLS for any of the used doses. However, the diameter of fibrillar wall was increased in response
to irradiation for microalgae exposed to 1 Gy and 2 Gy. The thickness of cell wall in microalgae
exposed to 5 Gy was not significantly different than in controls. A similar trend was
observed by gravimetry of dry cell wall isolates normalized to biomass. It is important to note that
no effects of radiation on biomass, at doses applied here, could be observed.
PB  - Institute for Biological Research “Siniša Stanković” and others contributors
C3  - 14th Multinational Congress on Microscopy. September 15–20, 2019, Belgrade, Serbia
T1  - The effects of ionizing radiation on the cell wall of microalgae Chlorella sorokiniana – TEM study
EP  - 153
SP  - 152
UR  - https://hdl.handle.net/21.15107/rcub_rimsi_2408
ER  - 

@conference{
author = "Danilović Luković, Jelena and Zechmann, Bernd and Vojvodić, Snežana and Bogdanović Pristov, Jelena and Stanić, Marina and Pittman, Jon K. and Spasojević, Ivan",
year = "2019",
abstract = "Cell wall of C. sorokiniana is composed of trilaminar sheath (TLS electron
translucent line inserted between two electron dense lines; the outermost layer is a mature mother
wall, while the thin inner layer is a daughter wall), and fibrilar cell wall. It is noteworthy that the
obtained diameters for untreated microalgae were in accordance with available data. The analysis of TEM micrographs showed that there were no significant changes in the thickness of
TLS for any of the used doses. However, the diameter of fibrillar wall was increased in response
to irradiation for microalgae exposed to 1 Gy and 2 Gy. The thickness of cell wall in microalgae
exposed to 5 Gy was not significantly different than in controls. A similar trend was
observed by gravimetry of dry cell wall isolates normalized to biomass. It is important to note that
no effects of radiation on biomass, at doses applied here, could be observed.",
publisher = "Institute for Biological Research “Siniša Stanković” and others contributors",
journal = "14th Multinational Congress on Microscopy. September 15–20, 2019, Belgrade, Serbia",
title = "The effects of ionizing radiation on the cell wall of microalgae Chlorella sorokiniana – TEM study",
pages = "153-152",
url = "https://hdl.handle.net/21.15107/rcub_rimsi_2408"
}

Danilović Luković, J., Zechmann, B., Vojvodić, S., Bogdanović Pristov, J., Stanić, M., Pittman, J. K.,& Spasojević, I.. (2019). The effects of ionizing radiation on the cell wall of microalgae Chlorella sorokiniana – TEM study. in 14th Multinational Congress on Microscopy. September 15–20, 2019, Belgrade, Serbia
Institute for Biological Research “Siniša Stanković” and others contributors., 152-153.
https://hdl.handle.net/21.15107/rcub_rimsi_2408

Danilović Luković J, Zechmann B, Vojvodić S, Bogdanović Pristov J, Stanić M, Pittman JK, Spasojević I. The effects of ionizing radiation on the cell wall of microalgae Chlorella sorokiniana – TEM study. in 14th Multinational Congress on Microscopy. September 15–20, 2019, Belgrade, Serbia. 2019;:152-153.
https://hdl.handle.net/21.15107/rcub_rimsi_2408 .

Danilović Luković, Jelena, Zechmann, Bernd, Vojvodić, Snežana, Bogdanović Pristov, Jelena, Stanić, Marina, Pittman, Jon K., Spasojević, Ivan, "The effects of ionizing radiation on the cell wall of microalgae Chlorella sorokiniana – TEM study" in 14th Multinational Congress on Microscopy. September 15–20, 2019, Belgrade, Serbia (2019):152-153,
https://hdl.handle.net/21.15107/rcub_rimsi_2408 .

TY  - CONF
AU  - Vojvodić, Snežana
AU  - Danilović Luković, Jelena
AU  - Zechmann, Bernd
AU  - Bogdanović Pristov, Jelena
AU  - Stanić, Marina
AU  - Pittman, Jon K.
AU  - Spasojević, Ivan
PY  - 2019
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/2414
AB  - Microalgae are exposed to ionizing radiation from natural (e.g. radionuclides from the soil) and anthropogenic sources (such as radioactive waste, nuclear power accidents, etc). However, the mechanisms of adaptation to radiation are poorly understood. The aim of our study was to determine the effects of X-ray irradiation on the cell wall of Chlorella sorokiniana. C. sorokiniana (CCAP 211/8K) culture was grown in 3N-BBM+V medium, at 22°C with a continuous photon flux of 120 μmol m−2 s−1 for 20 days, reaching stationary phase. Cultures were then exposed to X-rays at doses of 1, 2 and 5 Gy, left under the same conditions for additional 24 h, and analyzed using TEM (postfixation with 1% osmium tetroxide, embedded in resin for soft blocks, and stained with uranyl acetate and lead acetate), and gravimetry. The analysis of TEM micrographs showed that there were no significant changes in the thickness of trilaminar sheath for any of the used doses. However, the diameter of the fibrillar wall was increased in response to irradiation: 105.5 ± 7.5 nm for untreated samples vs. 135.0 ± 9.5 nm (p = 0.015) for microalgae exposed to 1 Gy, and 127.9 ± 7.4 nm (p = 0.036) for exposure to 2 Gy. The thickness of the cell wall in microalgae exposed to 5 Gy (118.6 ± 8.6 nm) was not significantly different than in controls. A similar trend was observed by gravimetry of dry cell wall isolates normalized to biomass. It is important to note that no effects of radiation on biomass, at doses applied here, could be observed. It appears that Chlorella sorokiniana responds promptly to ionizing radiation by fortifying its ‘first line of defense’. The observed changes may be of particular interest for bioremediation, taking into account the capacity of the cell wall to bind water-soluble metals, including radionuclides.
PB  - Taylor & Francis Group
C3  - Journal of Experimental Botany
T1  - Adaptive response of Chlorella sorokiniana to ionizing radiation on the level of cell wall
EP  - 166
IS  - Supp 1
SP  - 166
VL  - 54
DO  - 10.1080/09670262.2019.1626628
ER  - 

@conference{
author = "Vojvodić, Snežana and Danilović Luković, Jelena and Zechmann, Bernd and Bogdanović Pristov, Jelena and Stanić, Marina and Pittman, Jon K. and Spasojević, Ivan",
year = "2019",
abstract = "Microalgae are exposed to ionizing radiation from natural (e.g. radionuclides from the soil) and anthropogenic sources (such as radioactive waste, nuclear power accidents, etc). However, the mechanisms of adaptation to radiation are poorly understood. The aim of our study was to determine the effects of X-ray irradiation on the cell wall of Chlorella sorokiniana. C. sorokiniana (CCAP 211/8K) culture was grown in 3N-BBM+V medium, at 22°C with a continuous photon flux of 120 μmol m−2 s−1 for 20 days, reaching stationary phase. Cultures were then exposed to X-rays at doses of 1, 2 and 5 Gy, left under the same conditions for additional 24 h, and analyzed using TEM (postfixation with 1% osmium tetroxide, embedded in resin for soft blocks, and stained with uranyl acetate and lead acetate), and gravimetry. The analysis of TEM micrographs showed that there were no significant changes in the thickness of trilaminar sheath for any of the used doses. However, the diameter of the fibrillar wall was increased in response to irradiation: 105.5 ± 7.5 nm for untreated samples vs. 135.0 ± 9.5 nm (p = 0.015) for microalgae exposed to 1 Gy, and 127.9 ± 7.4 nm (p = 0.036) for exposure to 2 Gy. The thickness of the cell wall in microalgae exposed to 5 Gy (118.6 ± 8.6 nm) was not significantly different than in controls. A similar trend was observed by gravimetry of dry cell wall isolates normalized to biomass. It is important to note that no effects of radiation on biomass, at doses applied here, could be observed. It appears that Chlorella sorokiniana responds promptly to ionizing radiation by fortifying its ‘first line of defense’. The observed changes may be of particular interest for bioremediation, taking into account the capacity of the cell wall to bind water-soluble metals, including radionuclides.",
publisher = "Taylor & Francis Group",
journal = "Journal of Experimental Botany",
title = "Adaptive response of Chlorella sorokiniana to ionizing radiation on the level of cell wall",
pages = "166-166",
number = "Supp 1",
volume = "54",
doi = "10.1080/09670262.2019.1626628"
}

Vojvodić, S., Danilović Luković, J., Zechmann, B., Bogdanović Pristov, J., Stanić, M., Pittman, J. K.,& Spasojević, I.. (2019). Adaptive response of Chlorella sorokiniana to ionizing radiation on the level of cell wall. in Journal of Experimental Botany
Taylor & Francis Group., 54(Supp 1), 166-166.
https://doi.org/10.1080/09670262.2019.1626628

Vojvodić S, Danilović Luković J, Zechmann B, Bogdanović Pristov J, Stanić M, Pittman JK, Spasojević I. Adaptive response of Chlorella sorokiniana to ionizing radiation on the level of cell wall. in Journal of Experimental Botany. 2019;54(Supp 1):166-166.
doi:10.1080/09670262.2019.1626628 .

Vojvodić, Snežana, Danilović Luković, Jelena, Zechmann, Bernd, Bogdanović Pristov, Jelena, Stanić, Marina, Pittman, Jon K., Spasojević, Ivan, "Adaptive response of Chlorella sorokiniana to ionizing radiation on the level of cell wall" in Journal of Experimental Botany, 54, no. Supp 1 (2019):166-166,
https://doi.org/10.1080/09670262.2019.1626628 . .

TY  - CONF
AU  - Vojvodić, Snežana
AU  - Stanić, Marina
AU  - Jevtović (born Romanović), Mima
AU  - Dimitrijević, Milena
AU  - Bogdanović Pristov, Jelena
AU  - Morina, Arian
AU  - Pittman, Jon
AU  - Spasojević, Ivan
PY  - 2018
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/2962
AB  - Radiation hormesis is a biological phenomenon whereby a relatively low doses of radiation
induce beneficial effects on biological parameters, such as viability, growth, and metabolic
profile 1. A number of studies have documented stimulatory effects of low-dose X- and
gamma radiation on plant growth 2. However, radiation hormesis has not been investigated
in microalgae which are becoming a highly relevant source of lipid-derived biofuels. The
aim of this study was to establish the effects of low-dose X-irradiation on biomass and
lipid production in Chlorella sorokiniana. The microalgae cultures were exposed to total
doses of 10, 20 or 50 Gy at different irradiation rates (0.565; 2.290 and 5.057 Gy/min).
Absorbed doses corresponded to ~10% of the total dose, as determined by dosimetry. Lipid
content was determined 30 days after irradiation using Nile Red fluorescence assay with
excitation/emission maxima at 530/570 nm (total lipids), 480/575 nm (neutral lipids) and
549/628 nm (polar lipids) 3,4. Lipid content was normalized to dry biomass.
C3  - Serbian Biochemical Society Eighth Conference
T1  - Hormetic effects of low-dose radiation on lipid production in Chlorella sorokiniana
EP  - 195
SP  - 193
UR  - https://hdl.handle.net/21.15107/rcub_rimsi_2962
ER  - 

@conference{
author = "Vojvodić, Snežana and Stanić, Marina and Jevtović (born Romanović), Mima and Dimitrijević, Milena and Bogdanović Pristov, Jelena and Morina, Arian and Pittman, Jon and Spasojević, Ivan",
year = "2018",
abstract = "Radiation hormesis is a biological phenomenon whereby a relatively low doses of radiation
induce beneficial effects on biological parameters, such as viability, growth, and metabolic
profile 1. A number of studies have documented stimulatory effects of low-dose X- and
gamma radiation on plant growth 2. However, radiation hormesis has not been investigated
in microalgae which are becoming a highly relevant source of lipid-derived biofuels. The
aim of this study was to establish the effects of low-dose X-irradiation on biomass and
lipid production in Chlorella sorokiniana. The microalgae cultures were exposed to total
doses of 10, 20 or 50 Gy at different irradiation rates (0.565; 2.290 and 5.057 Gy/min).
Absorbed doses corresponded to ~10% of the total dose, as determined by dosimetry. Lipid
content was determined 30 days after irradiation using Nile Red fluorescence assay with
excitation/emission maxima at 530/570 nm (total lipids), 480/575 nm (neutral lipids) and
549/628 nm (polar lipids) 3,4. Lipid content was normalized to dry biomass.",
journal = "Serbian Biochemical Society Eighth Conference",
title = "Hormetic effects of low-dose radiation on lipid production in Chlorella sorokiniana",
pages = "195-193",
url = "https://hdl.handle.net/21.15107/rcub_rimsi_2962"
}

Vojvodić, S., Stanić, M., Jevtović (born Romanović), M., Dimitrijević, M., Bogdanović Pristov, J., Morina, A., Pittman, J.,& Spasojević, I.. (2018). Hormetic effects of low-dose radiation on lipid production in Chlorella sorokiniana. in Serbian Biochemical Society Eighth Conference, 193-195.
https://hdl.handle.net/21.15107/rcub_rimsi_2962

Vojvodić S, Stanić M, Jevtović (born Romanović) M, Dimitrijević M, Bogdanović Pristov J, Morina A, Pittman J, Spasojević I. Hormetic effects of low-dose radiation on lipid production in Chlorella sorokiniana. in Serbian Biochemical Society Eighth Conference. 2018;:193-195.
https://hdl.handle.net/21.15107/rcub_rimsi_2962 .

Vojvodić, Snežana, Stanić, Marina, Jevtović (born Romanović), Mima, Dimitrijević, Milena, Bogdanović Pristov, Jelena, Morina, Arian, Pittman, Jon, Spasojević, Ivan, "Hormetic effects of low-dose radiation on lipid production in Chlorella sorokiniana" in Serbian Biochemical Society Eighth Conference (2018):193-195,
https://hdl.handle.net/21.15107/rcub_rimsi_2962 .

TY  - CONF
AU  - Jevtović (born Romanović), Mima
AU  - Danilović Luković, Jelena
AU  - Morina, Arian
AU  - Kovačević, Snežana
AU  - Stanić, Marina
AU  - Spasojević, Ivan
PY  - 2018
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/2812
AB  - Pozitivan biološki odgovor ćelije ili organizma na stres niskog intenziteta se naziva hormezis. U višim biljkama je hormezis kao odgovor na niske doze zračenja dobro dokumentovan ali ovakva ispitivanja do sada nisu rađena na mikroalgama. Mikroalge su grupa organizama koji se lako prilagođavaju nepovoljnim uslovima sredine i na taj način mogu proizvesti veliku biomasu pri niskom sadržaju nutrijenata.Cilj ove studije je bio da ispita odgovor jednoćelijske zelene alge Chlamydomonas reinhardtii (CCAP 11/32C) na niske doze X-zračenja. Ispitivan je efekat na produkciju biomase kao i na promene u zastupljenosti hlorofila a (Chl a) i b (Chl b) u različitim fazama rasta nakon izlaganja tretmanu. Alge su izlagane zračenju od 10; 20; 50 i 100 Gy pri brzinama od 0,565; 2,290 i 5,057 Gy/min. Tretman od 10 Gy je pri brzini od 0,565 Gy/min doveo do povećanja biomase za 21±15% 15 dana nakon tretmana, a pri brzini od 2,290 Gy/min do povećanja od 19±8% već nakon 5 dana. Tretman od 20 Gy je pri brzini od 0,565 Gy /min doveo do povećanja biomase od 22±12% nakon 15 dana. Svi ostali tretmani ili nisu imali efekta ili su doveli do smanjenja biomase. Meren je i efekat zračenja na sadržaj Chl a i Chl b (μg/mg suve mase). Sadržaj ovih pigmenata vremenom opada ali neki tretmani su doveli do smanjenja ovog efekta. Doza od 20 Gy pri brzini od 2,290 Gy/min je dala najbolje efekte na očuvanje Chl a i Chl b i oni su u odnosu na kontrolu bili veći 31±9% i 31±8%.
PB  - Srpsko biološko društvo
C3  - II Kongres biologa Srbije
T1  - Uticaj niskih doza X zračenja na parametre vijabilnosti jednoćelijske alge Chlamydomonas reinhardtii
EP  - 222
SP  - 222
UR  - https://hdl.handle.net/21.15107/rcub_rimsi_2812
ER  - 

@conference{
author = "Jevtović (born Romanović), Mima and Danilović Luković, Jelena and Morina, Arian and Kovačević, Snežana and Stanić, Marina and Spasojević, Ivan",
year = "2018",
abstract = "Pozitivan biološki odgovor ćelije ili organizma na stres niskog intenziteta se naziva hormezis. U višim biljkama je hormezis kao odgovor na niske doze zračenja dobro dokumentovan ali ovakva ispitivanja do sada nisu rađena na mikroalgama. Mikroalge su grupa organizama koji se lako prilagođavaju nepovoljnim uslovima sredine i na taj način mogu proizvesti veliku biomasu pri niskom sadržaju nutrijenata.Cilj ove studije je bio da ispita odgovor jednoćelijske zelene alge Chlamydomonas reinhardtii (CCAP 11/32C) na niske doze X-zračenja. Ispitivan je efekat na produkciju biomase kao i na promene u zastupljenosti hlorofila a (Chl a) i b (Chl b) u različitim fazama rasta nakon izlaganja tretmanu. Alge su izlagane zračenju od 10; 20; 50 i 100 Gy pri brzinama od 0,565; 2,290 i 5,057 Gy/min. Tretman od 10 Gy je pri brzini od 0,565 Gy/min doveo do povećanja biomase za 21±15% 15 dana nakon tretmana, a pri brzini od 2,290 Gy/min do povećanja od 19±8% već nakon 5 dana. Tretman od 20 Gy je pri brzini od 0,565 Gy /min doveo do povećanja biomase od 22±12% nakon 15 dana. Svi ostali tretmani ili nisu imali efekta ili su doveli do smanjenja biomase. Meren je i efekat zračenja na sadržaj Chl a i Chl b (μg/mg suve mase). Sadržaj ovih pigmenata vremenom opada ali neki tretmani su doveli do smanjenja ovog efekta. Doza od 20 Gy pri brzini od 2,290 Gy/min je dala najbolje efekte na očuvanje Chl a i Chl b i oni su u odnosu na kontrolu bili veći 31±9% i 31±8%.",
publisher = "Srpsko biološko društvo",
journal = "II Kongres biologa Srbije",
title = "Uticaj niskih doza X zračenja na parametre vijabilnosti jednoćelijske alge Chlamydomonas reinhardtii",
pages = "222-222",
url = "https://hdl.handle.net/21.15107/rcub_rimsi_2812"
}

Jevtović (born Romanović), M., Danilović Luković, J., Morina, A., Kovačević, S., Stanić, M.,& Spasojević, I.. (2018). Uticaj niskih doza X zračenja na parametre vijabilnosti jednoćelijske alge Chlamydomonas reinhardtii. in II Kongres biologa Srbije
Srpsko biološko društvo., 222-222.
https://hdl.handle.net/21.15107/rcub_rimsi_2812

Jevtović (born Romanović) M, Danilović Luković J, Morina A, Kovačević S, Stanić M, Spasojević I. Uticaj niskih doza X zračenja na parametre vijabilnosti jednoćelijske alge Chlamydomonas reinhardtii. in II Kongres biologa Srbije. 2018;:222-222.
https://hdl.handle.net/21.15107/rcub_rimsi_2812 .

Jevtović (born Romanović), Mima, Danilović Luković, Jelena, Morina, Arian, Kovačević, Snežana, Stanić, Marina, Spasojević, Ivan, "Uticaj niskih doza X zračenja na parametre vijabilnosti jednoćelijske alge Chlamydomonas reinhardtii" in II Kongres biologa Srbije (2018):222-222,
https://hdl.handle.net/21.15107/rcub_rimsi_2812 .

TY  - JOUR
AU  - Kucirkova, Tereza
AU  - Stiborek, Marek
AU  - Ducka, Monika
AU  - Navratilova, Jarmila
AU  - Bogdanović Pristov, Jelena
AU  - Popovic-Bijelic, Ana
AU  - Vojvodić, Snežana
AU  - Preisler, Jan
AU  - Kanicky, Viktor
AU  - Smarda, Jan
AU  - Spasojević, Ivan
AU  - Benes, Petr
PY  - 2018
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1156
AB  - Wedelactone (WL), a plant polyphenolic derivative of coumestan, represents a promising anti-cancer agent. The underlying mechanisms of its action are not fully understood and appear to involve interplay with copper ions. Herein, we examined coordination and redox interactions of WL with Cu2+ in phosphate buffer (pH 7), and in two breast cancer cell lines. EPR, UV-Vis and fluorescence spectroscopy showed that WL and Cu2+ build a coordination complex with 2:1 stoichiometry and distorted tetrahedral geometry. WL showed strong fluorescence that was quenched by Cu2+. The sequestration of the intracellular copper pool with neocuproine led to a significant drop in the cytotoxic effects of WL, whereas the co-application of Cu2+ and WL and the formation of an extracellular complex suppressed both the cytotoxic effects of WL and copper loading. Fluorescence microscopy showed that WL is mainly localized in the cytosol and significantly less in the nuclei. WL fluorescence was stronger in cells pretreated with neocuproine, implying that the complex of WL and Cu2+ is formed inside the cells. WL caused a two-fold increase in the lysosomal level of copper as well as copper-dependent lysosome membrane permeabilization. On the other hand, the protective effects of overexpression of thioredoxin 1 imply that WL exerts the main oxidative impact inside the nucleus. The interactions of WL with copper may be essential for therapeutic performance and selectivity against cancer cells, taking into account that a number of cancer types, including breast cancer, exhibit increased intratumoral copper levels or altered copper distribution.
PB  - Royal Soc Chemistry, Cambridge
T2  - Metallomics
T1  - Anti-cancer effects of wedelolactone: interactions with copper and subcellular localization
EP  - 1531
IS  - 10
SP  - 1524
VL  - 10
DO  - 10.1039/c8mt00191j
ER  - 

@article{
author = "Kucirkova, Tereza and Stiborek, Marek and Ducka, Monika and Navratilova, Jarmila and Bogdanović Pristov, Jelena and Popovic-Bijelic, Ana and Vojvodić, Snežana and Preisler, Jan and Kanicky, Viktor and Smarda, Jan and Spasojević, Ivan and Benes, Petr",
year = "2018",
abstract = "Wedelactone (WL), a plant polyphenolic derivative of coumestan, represents a promising anti-cancer agent. The underlying mechanisms of its action are not fully understood and appear to involve interplay with copper ions. Herein, we examined coordination and redox interactions of WL with Cu2+ in phosphate buffer (pH 7), and in two breast cancer cell lines. EPR, UV-Vis and fluorescence spectroscopy showed that WL and Cu2+ build a coordination complex with 2:1 stoichiometry and distorted tetrahedral geometry. WL showed strong fluorescence that was quenched by Cu2+. The sequestration of the intracellular copper pool with neocuproine led to a significant drop in the cytotoxic effects of WL, whereas the co-application of Cu2+ and WL and the formation of an extracellular complex suppressed both the cytotoxic effects of WL and copper loading. Fluorescence microscopy showed that WL is mainly localized in the cytosol and significantly less in the nuclei. WL fluorescence was stronger in cells pretreated with neocuproine, implying that the complex of WL and Cu2+ is formed inside the cells. WL caused a two-fold increase in the lysosomal level of copper as well as copper-dependent lysosome membrane permeabilization. On the other hand, the protective effects of overexpression of thioredoxin 1 imply that WL exerts the main oxidative impact inside the nucleus. The interactions of WL with copper may be essential for therapeutic performance and selectivity against cancer cells, taking into account that a number of cancer types, including breast cancer, exhibit increased intratumoral copper levels or altered copper distribution.",
publisher = "Royal Soc Chemistry, Cambridge",
journal = "Metallomics",
title = "Anti-cancer effects of wedelolactone: interactions with copper and subcellular localization",
pages = "1531-1524",
number = "10",
volume = "10",
doi = "10.1039/c8mt00191j"
}

Kucirkova, T., Stiborek, M., Ducka, M., Navratilova, J., Bogdanović Pristov, J., Popovic-Bijelic, A., Vojvodić, S., Preisler, J., Kanicky, V., Smarda, J., Spasojević, I.,& Benes, P.. (2018). Anti-cancer effects of wedelolactone: interactions with copper and subcellular localization. in Metallomics
Royal Soc Chemistry, Cambridge., 10(10), 1524-1531.
https://doi.org/10.1039/c8mt00191j

Kucirkova T, Stiborek M, Ducka M, Navratilova J, Bogdanović Pristov J, Popovic-Bijelic A, Vojvodić S, Preisler J, Kanicky V, Smarda J, Spasojević I, Benes P. Anti-cancer effects of wedelolactone: interactions with copper and subcellular localization. in Metallomics. 2018;10(10):1524-1531.
doi:10.1039/c8mt00191j .

Kucirkova, Tereza, Stiborek, Marek, Ducka, Monika, Navratilova, Jarmila, Bogdanović Pristov, Jelena, Popovic-Bijelic, Ana, Vojvodić, Snežana, Preisler, Jan, Kanicky, Viktor, Smarda, Jan, Spasojević, Ivan, Benes, Petr, "Anti-cancer effects of wedelolactone: interactions with copper and subcellular localization" in Metallomics, 10, no. 10 (2018):1524-1531,
https://doi.org/10.1039/c8mt00191j . .