TY  - CONF
AU  - Santrač, Isidora
AU  - Danilović Luković, Jelena
AU  - Dimitrijević, Milena
AU  - Stanić, Marina
AU  - Tanović, Marija
AU  - Ćurić, Valentina
AU  - Kovačević, Snežana
AU  - Zechmann, Bernd
AU  - Žižić, Milan
AU  - Spasojević, Ivan
PY  - 2023
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/3144
AB  - Haematococcus pluvialis is a unicellular green alga with a complex life cycle and a
remarkable metabolic and structural adaptability that allows it to thrive in metal-infested
environments. H. pluvialis could be potentially used in the remediation of waters polluted
with metals, such as manganese (Mn). Mn is also an essential element involved in different
metabolic processes, such as photosynthesis and antioxidantive defence. Herein, we
examined morphological response of metabolically active green cell type of H. pluvialis
(microzooids) to high Mn concentrations exceeding their physiological quota. When exposed
to 1 mM Mn2+, cell viability remained stable over a 3-day period. Inductively coupled plasma
atomic emission spectroscopy showed the prompt uptake of Mn by the microzooid cells after
1 h of the treatment, with a modest increase of the concentration of Mn in the biomass at 24
h. Scanning electron microscopy revealed granular deposits on microzooid surfaces after 1
hour, likely Mn deposits, while transmission electron microscopy (TEM) micrographs
showed that some cells had wall rupture and degraded intracellular content and damaged
organelles. After 24 and 72 h, a different type of cell morphology emerged, characterized by
thickened cell wall, preserved intracellular compartments, and reduced total area of lipid
droplets. Both cell types exhibited vacuoles containing dark granules, possibly indicative of
Mn accumulations. Quantitative TEM analysis demonstrated that an excess of Mn reduced
cell cross-section and lipid droplet area while increasing vacuole cross-section and cell wall
thickness. The intricate adaptive responses of H. pluvialis to elevated Mn concentrations
exemplified by cell wall thickening, reduction in lipid droplets total area due to increased
energy demand, and the accumulation of Mn in vacuoles, exhibits the impressive structural
adaptability. Further investigation using analytical methods will provide a more profound
understanding of the metabolic dimensions of adaptive response
PB  - UNIVERSITY OF BELGRADE, FACULTY OF TECHNOLOGY AND METALLURGY Karnegijeva 4, Belgrade
C3  - International Conference on Biochemical Engineering and Biotechnology for Young Scientists, December 7-8th 2023, Belgrade, Serbia
T1  - Structural adaptibility of Haematococcus pluvialis green phase cells exposed to manganese excess
EP  - 44
SP  - 44
UR  - https://hdl.handle.net/21.15107/rcub_rimsi_3144
ER  - 

@conference{
author = "Santrač, Isidora and Danilović Luković, Jelena and Dimitrijević, Milena and Stanić, Marina and Tanović, Marija and Ćurić, Valentina and Kovačević, Snežana and Zechmann, Bernd and Žižić, Milan and Spasojević, Ivan",
year = "2023",
abstract = "Haematococcus pluvialis is a unicellular green alga with a complex life cycle and a
remarkable metabolic and structural adaptability that allows it to thrive in metal-infested
environments. H. pluvialis could be potentially used in the remediation of waters polluted
with metals, such as manganese (Mn). Mn is also an essential element involved in different
metabolic processes, such as photosynthesis and antioxidantive defence. Herein, we
examined morphological response of metabolically active green cell type of H. pluvialis
(microzooids) to high Mn concentrations exceeding their physiological quota. When exposed
to 1 mM Mn2+, cell viability remained stable over a 3-day period. Inductively coupled plasma
atomic emission spectroscopy showed the prompt uptake of Mn by the microzooid cells after
1 h of the treatment, with a modest increase of the concentration of Mn in the biomass at 24
h. Scanning electron microscopy revealed granular deposits on microzooid surfaces after 1
hour, likely Mn deposits, while transmission electron microscopy (TEM) micrographs
showed that some cells had wall rupture and degraded intracellular content and damaged
organelles. After 24 and 72 h, a different type of cell morphology emerged, characterized by
thickened cell wall, preserved intracellular compartments, and reduced total area of lipid
droplets. Both cell types exhibited vacuoles containing dark granules, possibly indicative of
Mn accumulations. Quantitative TEM analysis demonstrated that an excess of Mn reduced
cell cross-section and lipid droplet area while increasing vacuole cross-section and cell wall
thickness. The intricate adaptive responses of H. pluvialis to elevated Mn concentrations
exemplified by cell wall thickening, reduction in lipid droplets total area due to increased
energy demand, and the accumulation of Mn in vacuoles, exhibits the impressive structural
adaptability. Further investigation using analytical methods will provide a more profound
understanding of the metabolic dimensions of adaptive response",
publisher = "UNIVERSITY OF BELGRADE, FACULTY OF TECHNOLOGY AND METALLURGY Karnegijeva 4, Belgrade",
journal = "International Conference on Biochemical Engineering and Biotechnology for Young Scientists, December 7-8th 2023, Belgrade, Serbia",
title = "Structural adaptibility of Haematococcus pluvialis green phase cells exposed to manganese excess",
pages = "44-44",
url = "https://hdl.handle.net/21.15107/rcub_rimsi_3144"
}

Santrač, I., Danilović Luković, J., Dimitrijević, M., Stanić, M., Tanović, M., Ćurić, V., Kovačević, S., Zechmann, B., Žižić, M.,& Spasojević, I.. (2023). Structural adaptibility of Haematococcus pluvialis green phase cells exposed to manganese excess. in International Conference on Biochemical Engineering and Biotechnology for Young Scientists, December 7-8th 2023, Belgrade, Serbia
UNIVERSITY OF BELGRADE, FACULTY OF TECHNOLOGY AND METALLURGY Karnegijeva 4, Belgrade., 44-44.
https://hdl.handle.net/21.15107/rcub_rimsi_3144

Santrač I, Danilović Luković J, Dimitrijević M, Stanić M, Tanović M, Ćurić V, Kovačević S, Zechmann B, Žižić M, Spasojević I. Structural adaptibility of Haematococcus pluvialis green phase cells exposed to manganese excess. in International Conference on Biochemical Engineering and Biotechnology for Young Scientists, December 7-8th 2023, Belgrade, Serbia. 2023;:44-44.
https://hdl.handle.net/21.15107/rcub_rimsi_3144 .

Santrač, Isidora, Danilović Luković, Jelena, Dimitrijević, Milena, Stanić, Marina, Tanović, Marija, Ćurić, Valentina, Kovačević, Snežana, Zechmann, Bernd, Žižić, Milan, Spasojević, Ivan, "Structural adaptibility of Haematococcus pluvialis green phase cells exposed to manganese excess" in International Conference on Biochemical Engineering and Biotechnology for Young Scientists, December 7-8th 2023, Belgrade, Serbia (2023):44-44,
https://hdl.handle.net/21.15107/rcub_rimsi_3144 .

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 .