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  - Santrač, Isidora
AU  - Žižić, Milan
AU  - AQUILANTI, Giuliana
AU  - Gianoncelli, Alessandra
AU  - Bonanni, Valentina
AU  - Danilović Luković, Jelena
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/123456789/3139
AB  - Haematococcus pluvialis is a unicellular green alga of significant environmental and
economic impact, well adapted to life in extreme conditions such as metal pollution.
Manganese is a common pollutant of water bodies that is related to mining and industrial
drainage, and microalgae have been applied in their bioremediation. To study changes in Mn
redox and coordination form upon interaction with H. pluvialis cells, we exposed late
exponential/early stationary green phase culture to 1 mM MnCl2 (Mn2+) for 72 h. Applied
concentration exceeds microalgal physiological quota but it was non-toxic. Structure of
coordinated Mn in the cells was analyzed using X-ray absorption near edge structure
(XANES) and extended X-ray Absorption Fine Structure (EXAFS) spectroscopy, while
visualization and elemental mapping of Mn was performed by micro X-ray fluorescence
(μXRF). XANES spectra showed that the oxidation form of Mn in H. pluvialis biomass
remained 2+. However, EXAFS showed Mn coordination in microalgae is closer to hydrated
MnSO4 with minor deviation of the local geometry. The shorter Mn-O bonds in biomass,
compared to crystal model, implies somewhat more stable complex in H. pluvialis. This
suggests that H. pluvialis may use sulphated polysaccharides for Mn sequestration, which
would be a newly proposed mechanism of metal coordination and storage. μXRF analysis
showed co-localization of Mn with O and Na, with particularly good superimposition for Mn
and O. O-rich regions may represent vacuoles, filled with organic acids including sulphates,
or starch granules and accumulations of sulphated polysaccharides, which are known to be
produced by H. pluvialis. In addition, vacuoles in plant cells are known to act as sinks for
Na+ ions. These findings are in line with structural analysis that showed dark precipitates in
vacuoles, which are likely accumulations of Mn.
C3  - International Conference on Biochemical Engineering and Biotechnology for Young Scientists, December 7-8th 2023, Belgrade, Serbia
T1  - The coordination and storage of manganese in the microalga Haematococcus pluvialis
SP  - 45
UR  - https://hdl.handle.net/21.15107/rcub_rimsi_3139
ER  - 

@conference{
author = "Santrač, Isidora and Žižić, Milan and AQUILANTI, Giuliana and Gianoncelli, Alessandra and Bonanni, Valentina and Danilović Luković, Jelena and Dimitrijević, Milena and Stanić, Marina and Tanović, Marija and Ćurić, Valentina and Kovačević, Snežana and Spasojević, Ivan",
year = "2023",
abstract = "Haematococcus pluvialis is a unicellular green alga of significant environmental and
economic impact, well adapted to life in extreme conditions such as metal pollution.
Manganese is a common pollutant of water bodies that is related to mining and industrial
drainage, and microalgae have been applied in their bioremediation. To study changes in Mn
redox and coordination form upon interaction with H. pluvialis cells, we exposed late
exponential/early stationary green phase culture to 1 mM MnCl2 (Mn2+) for 72 h. Applied
concentration exceeds microalgal physiological quota but it was non-toxic. Structure of
coordinated Mn in the cells was analyzed using X-ray absorption near edge structure
(XANES) and extended X-ray Absorption Fine Structure (EXAFS) spectroscopy, while
visualization and elemental mapping of Mn was performed by micro X-ray fluorescence
(μXRF). XANES spectra showed that the oxidation form of Mn in H. pluvialis biomass
remained 2+. However, EXAFS showed Mn coordination in microalgae is closer to hydrated
MnSO4 with minor deviation of the local geometry. The shorter Mn-O bonds in biomass,
compared to crystal model, implies somewhat more stable complex in H. pluvialis. This
suggests that H. pluvialis may use sulphated polysaccharides for Mn sequestration, which
would be a newly proposed mechanism of metal coordination and storage. μXRF analysis
showed co-localization of Mn with O and Na, with particularly good superimposition for Mn
and O. O-rich regions may represent vacuoles, filled with organic acids including sulphates,
or starch granules and accumulations of sulphated polysaccharides, which are known to be
produced by H. pluvialis. In addition, vacuoles in plant cells are known to act as sinks for
Na+ ions. These findings are in line with structural analysis that showed dark precipitates in
vacuoles, which are likely accumulations of Mn.",
journal = "International Conference on Biochemical Engineering and Biotechnology for Young Scientists, December 7-8th 2023, Belgrade, Serbia",
title = "The coordination and storage of manganese in the microalga Haematococcus pluvialis",
pages = "45",
url = "https://hdl.handle.net/21.15107/rcub_rimsi_3139"
}

Santrač, I., Žižić, M., AQUILANTI, G., Gianoncelli, A., Bonanni, V., Danilović Luković, J., Dimitrijević, M., Stanić, M., Tanović, M., Ćurić, V., Kovačević, S.,& Spasojević, I.. (2023). The coordination and storage of manganese in the microalga Haematococcus pluvialis. in International Conference on Biochemical Engineering and Biotechnology for Young Scientists, December 7-8th 2023, Belgrade, Serbia, 45.
https://hdl.handle.net/21.15107/rcub_rimsi_3139

Santrač I, Žižić M, AQUILANTI G, Gianoncelli A, Bonanni V, Danilović Luković J, Dimitrijević M, Stanić M, Tanović M, Ćurić V, Kovačević S, Spasojević I. The coordination and storage of manganese in the microalga Haematococcus pluvialis. in International Conference on Biochemical Engineering and Biotechnology for Young Scientists, December 7-8th 2023, Belgrade, Serbia. 2023;:45.
https://hdl.handle.net/21.15107/rcub_rimsi_3139 .

Santrač, Isidora, Žižić, Milan, AQUILANTI, Giuliana, Gianoncelli, Alessandra, Bonanni, Valentina, Danilović Luković, Jelena, Dimitrijević, Milena, Stanić, Marina, Tanović, Marija, Ćurić, Valentina, Kovačević, Snežana, Spasojević, Ivan, "The coordination and storage of manganese in the microalga Haematococcus pluvialis" in International Conference on Biochemical Engineering and Biotechnology for Young Scientists, December 7-8th 2023, Belgrade, Serbia (2023):45,
https://hdl.handle.net/21.15107/rcub_rimsi_3139 .

TY  - JOUR
AU  - Žižić, Milan
AU  - Stanić, Marina
AU  - AQUILANTI, Giuliana
AU  - Bajuk-Bogdanovic, Danica
AU  - Branković, Goran
AU  - Rodić, Ivanka
AU  - Živić, Miroslav
AU  - Zakrzewska, Joanna
PY  - 2022
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/2106
AB  - Biotransformation of toxic selenium ions to non-toxic species has been mainly focused on biofortifcation of microorganisms 
and production of selenium nanoparticles (SeNPs), while far less attention is paid to the mechanisms of transformation. 
In this study, we applied a combination of analytical techniques with the aim of characterizing the SeNPs themselves as 
well as monitoring the course of selenium transformation in the mycelium of the fungus Phycomyces blakesleeanus. Red 
coloration and pungent odor that appeared after only a few hours of incubation with 10 mM Se+4 indicate the formation of 
SeNPs and volatile methylated selenium compounds. SEM–EDS confrmed pure selenium NPs with an average diameter 
of 57 nm, which indicates potentially very good medical, optical, and photoelectric characteristics. XANES of mycelium 
revealed concentration-dependent mechanisms of reduction, where 0.5 mM Se+4 led to the predominant formation of Se–S containing organic molecules, while 10 mM Se+4 induced production of biomethylated selenide (Se−2) in the form of volatile 
dimethylselenide (DMSe) and selenium nanoparticles (SeNPs), with the SeNPs/DMSe ratio rising with incubation time. 
Several structural forms of elemental selenium, predominantly monoclinic Se8 chains, together with trigonal Se polymer 
chain, Se8 and Se6 ring structures, were detected by Raman spectroscopy
PB  - Springer-Verlag GmbH Berlin Heidelberg
T2  - Analytical and Bianalytical Chemistry
T1  - Biotransformation of selenium in the mycelium of the fungus  Phycomyces blakesleeanus
EP  - 6222.
IS  - 20
SP  - 6213
VL  - 414
DO  - 10.1007/s00216-022-04191-4
ER  - 

@article{
author = "Žižić, Milan and Stanić, Marina and AQUILANTI, Giuliana and Bajuk-Bogdanovic, Danica and Branković, Goran and Rodić, Ivanka and Živić, Miroslav and Zakrzewska, Joanna",
year = "2022",
abstract = "Biotransformation of toxic selenium ions to non-toxic species has been mainly focused on biofortifcation of microorganisms 
and production of selenium nanoparticles (SeNPs), while far less attention is paid to the mechanisms of transformation. 
In this study, we applied a combination of analytical techniques with the aim of characterizing the SeNPs themselves as 
well as monitoring the course of selenium transformation in the mycelium of the fungus Phycomyces blakesleeanus. Red 
coloration and pungent odor that appeared after only a few hours of incubation with 10 mM Se+4 indicate the formation of 
SeNPs and volatile methylated selenium compounds. SEM–EDS confrmed pure selenium NPs with an average diameter 
of 57 nm, which indicates potentially very good medical, optical, and photoelectric characteristics. XANES of mycelium 
revealed concentration-dependent mechanisms of reduction, where 0.5 mM Se+4 led to the predominant formation of Se–S containing organic molecules, while 10 mM Se+4 induced production of biomethylated selenide (Se−2) in the form of volatile 
dimethylselenide (DMSe) and selenium nanoparticles (SeNPs), with the SeNPs/DMSe ratio rising with incubation time. 
Several structural forms of elemental selenium, predominantly monoclinic Se8 chains, together with trigonal Se polymer 
chain, Se8 and Se6 ring structures, were detected by Raman spectroscopy",
publisher = "Springer-Verlag GmbH Berlin Heidelberg",
journal = "Analytical and Bianalytical Chemistry",
title = "Biotransformation of selenium in the mycelium of the fungus  Phycomyces blakesleeanus",
pages = "6222.-6213",
number = "20",
volume = "414",
doi = "10.1007/s00216-022-04191-4"
}

Žižić, M., Stanić, M., AQUILANTI, G., Bajuk-Bogdanovic, D., Branković, G., Rodić, I., Živić, M.,& Zakrzewska, J.. (2022). Biotransformation of selenium in the mycelium of the fungus  Phycomyces blakesleeanus. in Analytical and Bianalytical Chemistry
Springer-Verlag GmbH Berlin Heidelberg., 414(20), 6213-6222..
https://doi.org/10.1007/s00216-022-04191-4

Žižić M, Stanić M, AQUILANTI G, Bajuk-Bogdanovic D, Branković G, Rodić I, Živić M, Zakrzewska J. Biotransformation of selenium in the mycelium of the fungus  Phycomyces blakesleeanus. in Analytical and Bianalytical Chemistry. 2022;414(20):6213-6222..
doi:10.1007/s00216-022-04191-4 .

Žižić, Milan, Stanić, Marina, AQUILANTI, Giuliana, Bajuk-Bogdanovic, Danica, Branković, Goran, Rodić, Ivanka, Živić, Miroslav, Zakrzewska, Joanna, "Biotransformation of selenium in the mycelium of the fungus  Phycomyces blakesleeanus" in Analytical and Bianalytical Chemistry, 414, no. 20 (2022):6213-6222.,
https://doi.org/10.1007/s00216-022-04191-4 . .