Physiology and methodology of chromium toxicity using alga Scenedesmus quadricauda as model object
Jazyk angličtina Země Anglie, Velká Británie Médium print-electronic
Typ dokumentu časopisecké články, práce podpořená grantem
PubMed
24972306
DOI
10.1016/j.chemosphere.2014.05.074
PII: S0045-6535(14)00720-6
Knihovny.cz E-zdroje
- Klíčová slova
- Antioxidative enzymes, Bioaccumulation, Confocal/fluorescence microscopy, Heavy metals, Oxidative stress,
- MeSH
- chlorofyl metabolismus MeSH
- chrom chemie toxicita MeSH
- fluorescence MeSH
- koncentrace vodíkových iontů MeSH
- látky znečišťující životní prostředí chemie toxicita MeSH
- mitochondriální proteiny metabolismus MeSH
- oxidace-redukce MeSH
- peroxidace lipidů účinky léků MeSH
- reaktivní formy kyslíku metabolismus MeSH
- Scenedesmus účinky léků fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- chlorofyl MeSH
- chrom MeSH
- látky znečišťující životní prostředí MeSH
- mitochondriální proteiny MeSH
- reaktivní formy kyslíku MeSH
Physiological responses of Scenedesmus quadricauda to Cr(VI) and Cr(III) excess were studied in buffer with circumneutral pH (6.5). Total Cr content was similar in low (1 μM of both oxidation states) but higher in 10 μM Cr(VI) treatment and high accumulation potential was detected (80-82% and 41-65% in 1 and 10 μM treatments, respectively). Specific fluorescence indicator (6-((anthracen-9-yl) methyleneamino)-2H-chromen-2-one) confirmed partial reduction of Cr(VI) to Cr(III) under exposure conditions. Viability and chlorophyll autofluorescence were more depleted by Cr(VI) while Cr(III) stimulated increase in ROS and lipid peroxidation. Antioxidative enzyme activities showed significantly higher values in 10 μM treatments of both Cr oxidation states. Depletion of mitochondrial proteins was not reflected in alteration of total soluble proteins indicating sensitivity of this organelle to Cr and TTC test showed no clear oxidation state-related effect. In this view, "Cr(VI) is not more toxic than Cr(III)" at least for some parameters. Subsequent study with the application of 10 μM Cr(VI) confirmed that HEPES buffer is more suitable exposure solution for toxicological studied than water or inorganic salts (higher chlorophyll autofluorescence was observed) and pH 6.5 is more suitable than low or high pH (4.5 or 8.5) in terms of Cr uptake. Another known Cr(III) fluorescence indicator (naphthalimide-rhodamine) also confirmed partial reduction of Cr(VI) to Cr(III) at acidic pH but only traces were seen at alkaline pH.
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