TY  - CONF
AU  - Žižić, Milan
AU  - Macura, Melanija
AU  - Zakrzewska, Joanna
AU  - Cvetić-Antić, Tijana
AU  - Zivić, Miroslav
AU  - Stanić, Marina
PY  - 2021
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1470
AB  - Selenium represents an essential microelement for many organisms, and exists in
several oxidation states. Selenite (Se4+) is often toxic due to its water solubility and bioavailability,
but can be reduced to insoluble Se0 by many microorganisms including fungi. Fungus
Phycomyces blakesleeanus reduces Se4+ to Se0 and forms selenium nanoparticles (BioSeNPs) as
witnessed by red coloration of the mycelium after 24h of treatment with 2, 5 and 10 mM Se4+. SEM
micrographics and EDS spectra confirmed presence of BioSeNPs with characteristic peaks at 1.4
(SeLα), 11.2 (SeKα) and 12.5 (SeKβ) keV. One of the mechanisms of selenite toxicity is considered
to be production of reactive oxygen species that then triggers response of cellular antioxidative
systems, among which important part is played by thiols such as glutathione. Glutathione is also
believed to play a more direct role in reduction of Se4+ to Se0 as proposed by the Painter reaction.
Thiol specific biradical EPR probe (RSSR) was used for EPR in vivo detection of intracellular thiolgroup modifications in mycelium of fungus P. blakesleanus treated by 0.1, 0.5, 1, 2, 5 and 10 mM
selenite (Na2SeO3) for 24 h. Decrease of available –SH groups is detected as the decrease in ratio
of mono- and biradical peak in the spectrum of the given sample. This ratio was 43.05 for control,
and didn’t change with 0.1 mM treatment (42.23), but halved to 23.55 with 0.5 mM Se4+. It further
decreased 10 × to minimal values of 4.31, 4.21, 4.1 and 3.5 with 1, 2, 5 and 10 mM Se4+, respectively.
This cannot be solely attributed to biomass decrease as it never decreased more than 45%. P.
blakesleeanus forms BioSeNPs from Se4+ and intracellular thiols are involved in this process
either through neutralization of ROS or directly in the reduction of Se4+, but most probably both.
PB  - Elsevier Science Inc, New York
C3  - Free Radical Biology and Medicine
T1  - Production of BioSeNPs in fungus Phycomyces blakesleanus is accompanied by decrease in intracellular thiols as detected by in vivo EPR
VL  - 177
DO  - 10.1016/j.freeradbiomed.2021.08.204
ER  - 

@conference{
author = "Žižić, Milan and Macura, Melanija and Zakrzewska, Joanna and Cvetić-Antić, Tijana and Zivić, Miroslav and Stanić, Marina",
year = "2021",
abstract = "Selenium represents an essential microelement for many organisms, and exists in
several oxidation states. Selenite (Se4+) is often toxic due to its water solubility and bioavailability,
but can be reduced to insoluble Se0 by many microorganisms including fungi. Fungus
Phycomyces blakesleeanus reduces Se4+ to Se0 and forms selenium nanoparticles (BioSeNPs) as
witnessed by red coloration of the mycelium after 24h of treatment with 2, 5 and 10 mM Se4+. SEM
micrographics and EDS spectra confirmed presence of BioSeNPs with characteristic peaks at 1.4
(SeLα), 11.2 (SeKα) and 12.5 (SeKβ) keV. One of the mechanisms of selenite toxicity is considered
to be production of reactive oxygen species that then triggers response of cellular antioxidative
systems, among which important part is played by thiols such as glutathione. Glutathione is also
believed to play a more direct role in reduction of Se4+ to Se0 as proposed by the Painter reaction.
Thiol specific biradical EPR probe (RSSR) was used for EPR in vivo detection of intracellular thiolgroup modifications in mycelium of fungus P. blakesleanus treated by 0.1, 0.5, 1, 2, 5 and 10 mM
selenite (Na2SeO3) for 24 h. Decrease of available –SH groups is detected as the decrease in ratio
of mono- and biradical peak in the spectrum of the given sample. This ratio was 43.05 for control,
and didn’t change with 0.1 mM treatment (42.23), but halved to 23.55 with 0.5 mM Se4+. It further
decreased 10 × to minimal values of 4.31, 4.21, 4.1 and 3.5 with 1, 2, 5 and 10 mM Se4+, respectively.
This cannot be solely attributed to biomass decrease as it never decreased more than 45%. P.
blakesleeanus forms BioSeNPs from Se4+ and intracellular thiols are involved in this process
either through neutralization of ROS or directly in the reduction of Se4+, but most probably both.",
publisher = "Elsevier Science Inc, New York",
journal = "Free Radical Biology and Medicine",
title = "Production of BioSeNPs in fungus Phycomyces blakesleanus is accompanied by decrease in intracellular thiols as detected by in vivo EPR",
volume = "177",
doi = "10.1016/j.freeradbiomed.2021.08.204"
}

Žižić, M., Macura, M., Zakrzewska, J., Cvetić-Antić, T., Zivić, M.,& Stanić, M.. (2021). Production of BioSeNPs in fungus Phycomyces blakesleanus is accompanied by decrease in intracellular thiols as detected by in vivo EPR. in Free Radical Biology and Medicine
Elsevier Science Inc, New York., 177.
https://doi.org/10.1016/j.freeradbiomed.2021.08.204

Žižić M, Macura M, Zakrzewska J, Cvetić-Antić T, Zivić M, Stanić M. Production of BioSeNPs in fungus Phycomyces blakesleanus is accompanied by decrease in intracellular thiols as detected by in vivo EPR. in Free Radical Biology and Medicine. 2021;177.
doi:10.1016/j.freeradbiomed.2021.08.204 .

Žižić, Milan, Macura, Melanija, Zakrzewska, Joanna, Cvetić-Antić, Tijana, Zivić, Miroslav, Stanić, Marina, "Production of BioSeNPs in fungus Phycomyces blakesleanus is accompanied by decrease in intracellular thiols as detected by in vivo EPR" in Free Radical Biology and Medicine, 177 (2021),
https://doi.org/10.1016/j.freeradbiomed.2021.08.204 . .