Limnologica. 2014 Jan;44:72– 80.
Iara
Rocchetta, Betina J. Lomovasky, Maria S. Yusseppone, Sebastián E.
Sabatini,Flavia Bieczynski, María C. Ríos de Molina, Carlos M. Luquet.
rocchetta@bg.fcen.uba.ar,irocchetta@gmail.com
(I. Rocchetta).
Abstract
Three populations of Diplodon
chilensis (Hiridae, Bivalvia) from North Patagonia (Lacar lake, Argentina) have
been studied to determine how organic matter (OM) influence their growth,
density, morphometric and metabolic parameters in two pristine sites (Yuco and
Nonthué) and in a growing touristic locality (SanMartín de los Andes Bay, site
SMA) affected by urban discharges. In Nonthué (chemical and biologicaloxygen
demand ratio COD/BOD ratio of 4.7), a dense neighboring forest provides higher
quantities of vegetal detritus compared to Yuco, while in SMA the OM input
increase is related to anthropogenic impact, mainly sewage discharges, which is
more biodegradable (COD/BOD ratio of 1.7). Our results show that population’s
size distribution and growth rates are affected positively by increased OM,
independently of its natural or anthropogenic origin. The modal shell length
interval for SMA and Nonthué is two-fold higher (70 mm), in agreement to the
growth rate increase (k = 0.079), compared to Yuco (35 mm,k = 0.045). The
morphometric relationships between size–size and size–mass show a higher slope
for SMA and Nonthué, which underline allometric differences between these two
populations and the Yuco’s one. The lower population densities in both sites
(SMA 33 ind./m2 and Nonthué 76 ind./m2) compare to Yuco (176 ind./m2) and the
absence of individuals younger than 7 and 5 years old, respectively, in SMA
and Nonthué could be related to the higher allochthonous OM content in the
sediments and total suspended solids in water. Increased OM due to urban
pollution in SMA bivalves leads to higher oxidative damage to lipids, which is
not counter balanced by the higher detoxification enzyme
glutathione-S-transferaseactivity. Hence, we can conclude that pollution would
explain the drastic reduction in population density,probably related to a high
impair in the juvenile’s survival/recruitment, the higher observed mortality and
the lower population longevity. When increased OM is supply by the forest, like
in Nonthué, this hasless negative effect on population density and no effect on
longevity at all. However, a negative effect of oxygen depletion due to
increased OM (either anthropogenic or natural) on juvenile survival cannot
be discarded, but further studies should be carried out to support this idea.
Aquatic Toxicology. 2013 Nov 15;144-145:26-35.
Karina
Bianco, María Soledad Yusseppone, Sofía Otero, Carlos Luquet, María del Carmen
Ríos de Molina, Gisela Kristoff
gkristoff@qb.fcen.uba.ar,
giselakristoff@hotmail.com
Abstract
In the Upper Valley of Río
Negro and Río Neuquén in Argentina, agriculture represents the second most
important economic activity. Azinphos-methyl has been found in water from this
region throughout the year at a maximum concentration of 22.48 μg L-1 during
the application period. Toxicological studies on local non-target species have
been performed mostly on vertebrates, while mollusks, which could be more
sensitive, have not been studied so far. This work aims to characterize
cholinesterase (ChE) and
38 carboxilesterase (CE)
activities of Chilina gibbosa, a freshwater gastropod native to southern
Argentina and Chile. These enzymes, together with neurotoxicity signals, are
evaluated herein after as sensitive biomarkers of exposure to azinphos-methyl
at environmentally relevant concentrations. Effects of azinphos-methyl on
antioxidant defenses: glutathione (GSH), catalase (CAT), superoxide dismutase
(SOD) and glutathione S-transferase (GST) are also studied in order to complete
a set of biomarkers with different sensitivity and specificity, to propose C.
gibbosa as a sentinel species. The highest specific activity was obtained with
acetylthiocholine as substrate, followed by propionylthiocholine (83 % in
comparison to acetylthiocholine ) and butyrylthiocholine (19 %).The lowest Km
and the highest efficiency for ChE were obtained with acetylthiocholine. Regarding
CEs activities, a higher efficiency was obtained with p-nitrophenyl butyrate
than with p-nitrophenyl acetate. Eserine produced significant inhibition of ChE
activity (81 % with 0.001 mM and 98 % with 1 mM) while iso-OMPA did not produce
any significant effect on ChE. Our results show that C. gibbosa ChE is very
sensitive to azinphos-methyl (CI50 0.02 μg L-1) while CEs are inhibited at
higher concentrations (CI50 1000 μg L-1). CEs have been reported to be more
sensitive to OPs than ChEs in most of the aquatic invertebrates protecting the
organisms from neurotoxic effects. In contrast, C. gibbosa, has ChE which are
much more sensitive to azinphos-methyl than CEs and shows marked signs of
neurotoxicity. Regarding antioxidant defenses, GSH levels were significantly
increased by 0.02 and 20 μg L-1 azinphos-methyl (80 and 103 %, respectively),
CAT activity was increased 85% only at 0.02 μg L-1 and SOD and GST did not show
any significant response. Since ChE activity, neurotoxicity
signs, GSH and CAT are sensitive biomarkers of acute exposure to
azinphos-methyl at environmental concentrations C. gibbosa could be included as
sentinel species in monitoring programs of pesticide hazard in regions of
Argentina and Chile.
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Marine Environmental Research. 2013 Oct. In Press (ISSN: 0141-1136).
Pablo Di
Salvatore; Javier A Calcagno; Nicolás Ortíz; María del Carmen Ríos de Molina;
Sebastián E. Sabatini
sabatini@bg.fcen.uba.ar
Abstract
This study investigated the effects of pollution and its
interaction with temperature on the oxidative status of the ribbed mussel
Aulacomya atra in the southern Atlantic Patagonian coast. Animals were
collected from four sites with different degree and type of human activity
impact, during the summer and winter of 2011. Seawater chromium, copper,
manganese, nickel and zinc concentrations were measured, as well as metal
accumulation, lipid peroxidation, protein oxidation, reduced glutathione
levels, and enzymatic activities of superoxide dismutase and glutathione-S-
transferase in gills and digestive glands.
Metal bioacumulation and oxidative stress responses in both tissues were
generally higher in mussels from harbor areas. Water temperature had a
remarkable effect on gill SOD activity and protein oxidation during winter in
mussels from all locations.
Methodologically, we conclude that measuring both metal bioaccumulation
and oxidative stress responses allowed for a more accurate assessment of the
biological effects of metal present in seawater.
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Environmental Toxicology and Chemistry. 2012 May; 31(5):968-972.
Oxidative damage and antioxidant response of Allium cepa meristematic and elongation cells exposed to Metronidazole.
Nancy Andrioli, Sebastián E. Sabatini, Marta D. Mudry, María del Carmen Ríos de Molina
Nancy Andrioli, Sebastián E. Sabatini, Marta D. Mudry, María del Carmen Ríos de Molina
sabatini@bg.fcen.uba.ar
The toxicity of metronidazole (MTZ) in meristematic and
elongation zones of Allium cepa roots was analyzed for 30 hours of exposition.
Toxic effects were evaluated by lipid peroxidation (content of thiobarbituric
reactive substances -TBARS-), reduced glutathione (GSH) levels, ascorbate acid
(AA) and dehydroascorbate acid (DHA) content and enzymatic activities of
superoxide dismutase (SOD) and catalase (CAT). The root zones showed
differentiated susceptibility to MTZ. In the elongation zone, MTZ induced an increase
of TBARS content, and a significant rise in GSH levels, whereas in the
meristematic zone, lipid peroxidation was not observed and all antioxidant
defense parameters analyzed were significantly incremented. These results
indicate that MTZ exposure induced oxidative stress in A. cepa roots, and the
antioxidant defenses in the meristematic zone are more efficient in comparison
to the elongation zone, which is probably related to higher oxidative
metabolism of meristematic tissue.
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Phycologia. 2012 Mar; 51(2):135-143.
Abelardo A.
Sztrum, Sebastián E. Sabatini, María C. Rodríguez.
sabatini@bg.fcen.uba.ar
Abstract
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Limnologica- Ecology and Management of Inland Waters. 2011 Dec; 41(4):356-362.
Sebastián
E. Sabatini, Iara Rocchetta, Carlos Luquet, Mariana I. Guido, María del Carmen
Ríos de Molina.
sabatini@bg.fcen.uba.ar
The effect of chronic exposure to Escherichia coli on morphometrical parameters, different antioxidant defenses, lipid peroxidation and protein oxidation has been studied in digestive gland of the freshwater clam Diplodon chilensis in the laboratory during six weeks. In, a parallel field study, we evaluated morphometrical and oxidative stress parameters in digestive glands of clams collected from a sewage polluted area (SMA) and from a pristine area (control). Both sites were characterized by analyzing bacteriological and physic-chemical parameters. In the laboratory D. chilensis was able to filter bacteria at high concentrations with a clearing rate of 0.510 ± 0.036 L/h per gram of dry soft tissue mass. The digestive gland mass to shell length ratio (DGM/SL), reduced glutathione (GSH), lipid peroxidation, as concentration of thiobartituric acid reactive substances (TBARS), and Glutathione-S transferase (GST) activity of clams fed with bacteria were significantly higher than those of control clams after the fourth week. Fecal bacteria in lake water samples were undetectable in the control, and higher than 24000 MPN (most probable number) /100 mL in SMA. DGM/SL was higher in SMA. No differences between sites were observed in total lipid and protein content, neither in superoxide dismutase activity. GSH content was higher in SMA, with no difference in the oxidized form. GST activity and MDA were significantly higher in SMA but protein oxidation was not affected. Escherichia coli on morphometrical parameters,different antioxidant defenses, lipid peroxidation and protein oxidation has been studied in digestive gland of the freshwater clam Diplodon chilensis in the laboratory during six weeks. In, a parallel field study, we evaluated morphometrical and oxidative stress parameters in digestive glands of clams collected from a sewage polluted area (SMA) and from a pristine area (control). Both sites were characterized by analyzing bacteriological and physic-chemical parameters. In the laboratory D. chilensis was able to filter bacteria at high concentrations with a clearing rate of 0.510 ± 0.036 L/h per gram of dry soft tissue mass. The digestive gland mass to shell length ratio (DGM/SL), reduced glutathione (GSH), lipid peroxidation, as concentration of thiobartituric acid reactive substances (TBARS), and Glutathione-S transferase (GST) activity of clams fed with bacteria were significantly higher than those of control clams after the fourth week. Fecal bacteria in lake water samples were undetectable in the control, and higher than 24000 MPN (most probable number) /100 mL in SMA. DGM/SL was higher in SMA. No differences between sites were observed in total lipid and protein content, neither in superoxide dismutase activity. GSH content was higher in SMA, with no difference in the oxidized form. GST activity and MDA were significantly higher in SMA but protein oxidation was not affected.
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Comparative Biochemistry and Physiology, Part C. 2011 Nov; 154:391-398.Oxidative stress and histological alterations produced by dietary copper in the fresh water bivalve Diplodon chilensis.
Sebastián E. Sabatini, Iara Rocchetta, Daniel E. Nahabedian, Carlos M. Luquet, Maria Rosa Eppis, Laura Bianchi, María del Carmen Ríos de Molina
sabatini@bg.fcen.uba.ar
Abstract
The aim of this work was to study the oxidative stress effects and histological alterations caused by dietary copper on the filter-feeding freshwater mussel Diplodon chilensis. Bivalves were fed during 6 weeks with the green algae Scenedesmus vacuolatus previously exposed to copper. Metal concentration in algae cultures and bivalve digestive gland was measured by TXRF. A maximum accumulation of 0.49 ìg Cu/mg proteins was detected at week 6. Also at this week, the hepatosomatic index (HSI) showed the highest decrease (50%) in response to Cu exposure. SOD and GST activities were significantly increased at weeks 4, 5 and 6, reaching an activity on average 50% higher than in controls for GST. CAT activity and GSH increased significantly at weeks 5 and 6. Despite this response, oxidative damage measured as TBARS and carbonyl groups contents increased significantly at weeks 4, 5 and 6, respectively. Digestive tubule and duct atrophy and cell-type replacement in treated mussels were observed by histological studies. The presence of intracellular rhodanine-positive granules, suggests copper accumulation in intracellular vacuoles of digestive cells. Bivalves were fed during 6 weeks with the green algae Scenedesmus vacuolatus previously exposed to copper. Metal concentration in algae cultures and bivalve digestive gland was measured by TXRF. A maximum accumulation of 0.49 ug Cu/mg proteins was detected at week 6. Also at this week, the hepatosomatic index (HSI) showed the highest decrease (50%) in response to Cu exposure. SOD and GST activities were significantly increased at weeks 4, 5 and 6, reaching an activity on average 50% higher than in controls for GST. CAT activity and GSH increased significantly at weeks 5 and 6. Despite this response, oxidative damage measured as TBARS and carbonyl groups contents increased significantly at weeks 4, 5 and 6, respectively. Digestive tubule and duct atrophy and cell-type replacement in treated mussels were observed by histological studies. The presence of intracellular rhodanine-positive granules, suggests copper accumulation in intracellular vacuoles of digestive cells.
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Ecotoxicology and Environmental Safety. Jul 2011; 74:1188-1194.Microcystin accumulation and antioxidant responses in the freshwater clam Diplodon chilensis patagonicus upon subchronic exposure to toxic Microcystis aeruginosa.
Sebastián E. Sabatini, Beatriz M. Brena, Carlos M. Luquet, Magdalena San Julian, Macarena Pirez, María del Carmen Ríos de Molina.
sabatini@bg.fcen.uba.ar
Abstract
We investigated the accumulation and toxicity of microcystin-LR (MCLR) in the digestive gland of the fresh water clam Diplodon chilensis patagonicus. Treated clams were fed with a toxic strain of Microcystis aeruginosa (NPJB1)during 6 weeks and control clams received the non-toxic strain NPDC1.Filtration rate was estimated for both groups. Toxic effects were evaluated through the hepatosomatic index (HSI) and different oxidative stress biomarkers, lipid peroxidation (content of thiobarbituric reactive substances-TBARS), protein oxidation (carbonylgroups) and reduced glutathione (GSH) levels,and enzymatic activities of superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase(GST). The extractable MCLR measured by ELISA in digestive gland extracts showed little or no change during the first 3 weeks and increased significantly at weeks 5 and 6. HSI was reduced by 30 % intreated clams at weeks 5 and 6. No significant oxidative damage to lipids or proteins was observed. All the antioxidant defense parameters analyzed were significantly increased at week 5 or 6. GSH increased in treated clams at week 5, reaching 62 % increase at week 6. SOD, CAT and GST activities were significantly increased in treated clams by 50 %, 66 % and 60 %, respectively, at the end of the experiment. D. chilensis patagonicus can be exposed to prolonged cyanobacterial blooms accumulating significant quantities of MCLR,which could be a risk for mammals and birds, which feed on this species and, in a lesser extent, to humans.
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Phycologia. 2011 Jan; 50(1):78-88.Responses to sublethal copper exposure in two strains of Chlamydomonas reinhardtii in autotrophic and mixotrophic conditions
Sebastián E. Sabatini, Patricia I. Leonardi, María C. Rodríguez.
sabatini@bg.fcen.uba.ar
Abstract
The aim of this work was to determine the responses to sublethal copper exposure (20 and 40 mM CuCl) in two Chlamydomonas reinhardtii strains: the wild type 4A+ and the pleiotropic mutant cur9, originally selected as a copper-tolerant phenotype in mixotrophic conditions. Bioassays were performed in both autotrophic and mixotrophic media, under low irradiation (50 mol -2-1). At the onset, Cu2+ concentration in culture media was estimated by MINEQL software. Oxidative stress indicators, such as changes in photosynthetic pigment ratios, catalase activity, concentration of thiobartituric acid reactive substances (TBARS) and growth rate demonstrated a better performance of the wild type and the mutant strain in autotrophic and mixotrophic conditions, respectively. Moderate oxidative stress was accompanied by ultrastructural changes, such as accumulation of starch and vacuoles with electronic-dense deposits and membranous structures together with mild thylakoidal and mitochondrial crest disorganization. In mixotrophic conditions isocitrate lyase (ICL) activity peaked after 72-hour incubation. An inverse relation between catalase and ICL activities was verified and proved to be a good indicator of oxidative stress correlating consistently with other characteristic features such as, depression in growth rate or increase in TBARS dosage.
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Comparative Biochemistry and Physiology, Part C. 2009 Nov; 150(4):521-527.Dietary copper effects in the estuarine crab, Neohelice (Chasmagnathus) granulata, maintained at two different salinities
Sebastián E. Sabatini, Gabriela Chaufan, Ángela B. Juárez, Isis Coalova, Laura Bianchi, Maria R. Eppis, María del Carmen Ríos de Molina.
sabatini@bg.fcen.uba.ar
Abstract
We have analyzed the dietary copper effects in the estuarine crab Neohelice (Chasmagnathus) granulata and its interaction with water salinity. Crabs were maintained at 2 ‰ and 30 ‰ salinity for 5 weeks and they were fed with commercial food supplemented with the green alga Scenedesmus vacuolatus previously exposed to copper. No mortalities were observed, but crabs maintained at 2 ‰ salinity accumulated on average 40 % more copper compared to animals maintained at 30 ‰ salinity. At 2 ‰ salinity, SOD activity and GSH levels were increased at the first and second weeks, respectively, while lipid peroxidation and protein oxidation were evident after four weeks of copper exposure. At 30 ‰ salinity, all measured variables increased progressively but were significantly higher only at the end of the assay (5 week), except for protein oxidation that remained unchanged throughout the experiment. The hepatosomatic index (HSI) was significant decreased in response to copper exposure, but only in crabs acclimated to 2 ‰. These findings have suggested that dietary copper exposure induces greater metal accumulation and larger oxidative stress responses in crabs maintained at 2 ‰ salinity.
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Ecotoxicology and Environmental Safety. 2009 May; 72(4):1200-1206.Oxidative stress and antioxidant defenses in two green microalgae exposed to copper.
Sebastián E. Sabatini, Ángela B. Juárez, Maria R. Eppis, Laura Bianchi, Carlos M. Luquet, María del Carmen Ríos de Molina
sabatini@bg.fcen.uba.ar
Abstract
Copper content was determined in both strains by total X-ray reflection fluorescencean analysis (TXRF). In S. vacuolatus, the increase of medium copper concentration induced an augmentation of protein and MDA content, and a significant decrease in the chlorophyll a/chlorophyll b ratio. S. vacuolatus showed a significant increase of catalase activity in 210 and 414 uM of copper, and a significant increment of SOD activity and GSH content only in 414 uM of copper. On the contrary, C. kessleri did not show significant differences in these parameters between 6.2 and 108 uM of copper. Increased copper in the environment evokes oxidative stress and an increase in the antioxidant defenses of S. vacuolatus.
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American Journal of Physiology. Regulatory, Integrative and Comparative Physiology. 2008 Mar; 294(3): 1033–1043.Regulation of ion transport by pH and [HCO3-] in isolated gills of the crab Neohelice (Chasmagnathus) granulata
Tresguerres, Martin; Parks, Scott; Sabatini, Sebastián; Goss, Greg; Luquet, Carlos.
sabatini@bg.fcen.uba.ar
Abstract
Posterior isolated gills of Neohelice (Chasmagnathus) granulatus were symmetrically perfused with hemolymph-like saline of varying [HCO3] and pH. Elevating [HCO3] in the saline from 2.5 to 12.5 mmol/l (pH 7.75 in both cases) induced a significant increase in the transepithelial potential difference (Vte), a measure of ion transport. The elevation in [HCO3] also induced a switch from acid secretion (43.7+-22.5 equiv kg h) in controls to base secretion (84.7+-14.4 equiv kg h). The HCO3 -induced Vte increase was inhibited by basolateral acetazolamide (200 _mol/l), amiloride (1 mmol/l), and ouabain (5 mmol/l) but not by bafilomycin (100 nmol/l). The Vte response to HCO3 did not take place in Cl_-free conditions; however, it was unaffected by apical SITS (2 mmol/l) or DIDS (1 mmol/l). A decrease in pH from 7.75 to 7.45 pH units in the perfusate also induced a significant increase in Vte, which was matched by a net increase in acid secretion of 67.8 _ 18.4 _equiv kg_1 h_1. This stimulation was sensitive to basolateral acetazolamide, bafilomycin, DIDS, and Na_-free conditions, but it still took place in Cl_-free saline. Therefore, the cellular response to low pH is different from the HCO3 -stimulated response. We also report V-H_-ATPase- and Na_- K_-ATPase-like immunoreactivity in gill sections for the first time in this crab. Our results suggest that carbonic anhydrase (CA), basolateral Na_/H_ exchangers and Na_-K_-ATPase and apical anion exchangers participate in the HCO3 -stimulated response, while CA, apical V-H_-ATPase and basolateral HCO3 -dependent cotransporters mediate the response to low pH.
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Toxicity of hexachlorobenzene and its transference from microalgae (Chlorella kessleri) to crabs (Chasmagnathus granulatus)
Chaufan G, Juárez A, Basack S, Ithuralde E, Sabatini SE, Genovese G, Oneto ML, Kesten E, Ríos de Molina M del C.
Chaufan G, Juárez A, Basack S, Ithuralde E, Sabatini SE, Genovese G, Oneto ML, Kesten E, Ríos de Molina M del C.
gchaufan@qb.fcen.uba.ar
Abstract
Abstract
Abstract
The aim of this work was to study the transference of hexachlorobenzene from a green alga (Chlorella kessleri) to an estuary crab (Chasmagnathus granulatus), and to analyze the toxic effects that the xenobiotic has on the latter. The effect of hexachlorobenzene uptake was evaluated measuring oxidative stress, Uroporphyrinogen decarboxylase activity and morphometric parameter alteration, and also performing a histological analysis of crab hepatopancreas. Results demonstrated that hexachlorobenzene enters the alga, is accumulated in it, and then transferred into the crab, causing a decrease in Uroporphyrinogen decarboxylase activity in both organisms. The high malondialdehyde levels detected in crab hepatopancreas after the toxic treatment suggested the existence of hexachlorobenzene-induced lipid peroxidation. Antioxidant defenses such as superoxide dismutase activity and reduced glutathione content fell below normal values on the fourth week of treatment. At the same time, the hepatosomatic index, used as a morphometric parameter, reduced 20% with respect to the control. The histological analysis revealed epithelium disorganization in hepatopancreas tubules, confirming the existence of structural damage caused by hexachlorobenzene.
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Environmental Pollution.2006 May;141(2):353-358.
Effect of chromium on the fatty acid composition of two strains of Euglena gracilis
Iara Rocchetta, Marcia Mazzuca, Visitación Conforti, Laura Ruiz, Vilma Balzaretti, María del Carmen Ríos de Molina
Effect of chromium on the fatty acid composition of two strains of Euglena gracilis
Iara Rocchetta, Marcia Mazzuca, Visitación Conforti, Laura Ruiz, Vilma Balzaretti, María del Carmen Ríos de Molina
rocchetta@bg.fcen.uba.ar
Abstract
The effect of hexavalent chromium on fatty acid composition was studied in two strains of Euglena gracilis; UTEX 753 (from the Culture Collection of Algae of Texas University, USA) and MAT (isolated from a highly polluted River). Both were grown in photoauxotrophic and photoheterotrophic conditions and exposed to two metal concentrations, one below and one above IC50. The high malondialdehyde (MDA) levels (3 to 7-fold) obtained with chromium concentration above IC50, suggested the existence of metal-induced lipid peroxidation. Total lipid content increased only with concentration below IC50, whereas it was inhibited by higher metal concentration. Photoheterotrophic control strains exhibited a significantly higher proportion of saturated and polyunsaturated fatty acids. Polyunsaturated acids were most affected by chromium, especially those related to chloroplast structures. Ultra-structure studies showed clear thylakoid disorganization in all treated cells. The results indicate that hexavalent chromium affects levels of fatty acids, especially those related to photosynthetic activity.
