Abstracto

Metabolic Adaptations to Arsenic-Induced Oxidative Stress in Hapalosiphon fontinalis-339

Sunaina Zutshi, Fareha Bano, Manikar Ningthoujam, Khalid Habib & Tasneem Fatma

Arsenic is the most common nonessential widely occurring metal with serious hazardous impacts on living organism. Arsenic enriched soils are considered major sources of contamination in the food chains and water supplies. Presence of arsenic is of great environmental concern due to its carcinogenic and mutagenic property in addition to high toxicity. Very little work is done on arsenic induced toxicity and resistance in cyanobacteria who are main producer of aquatic system. Thus during present investigation, in vitro study was done to determine the toxic effect of Sodium Arsenate (0- 100mM) on an aquatic cyanobacteria Hapalosiphon fontinalis-339 with respect to lipid peroxidation, ion leakage, photosynthetic pigments, antioxidant enzymes and non enzymic oxidative substances. 50% decrease in growth (LC50) was observed at 70 mM sodium arsenate. A marked reduction in photosynthetic pigments was observed in test organism at sublethal concentration (100mM sodium arsenate). At this level MDA production was enhanced that probably resulted in decreased growth of the test organism. Accumulation of enzymic and non enzymic substance e.g. superoxide dismutase, catalase, and ascorbate peroxidase activiti