Biochemical Analysis of Anabaena variabilis Exposed to Malathion Pesticide with Special Reference to Oxidative Stress and Osmolytes

Cyanobacteria contribute significantly to the maintenance of flooded rice field fertility. In this investigation, the protective effect of osmolytes and antioxidative enzymes was studied on the paddy field cyanobacterial biofertilizer; Anabaena variabilis exposed to Malathion pesticide. With increasing concentration of malathion the test organism showed increased free radical mediated toxicity. The activity of antioxidative enzymes superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) enhanced considerably. Interestingly, osmolytes ─ proline, sucrose, mannitol, trehalose and glycogen levels also increased under the malathion treatment indicating their involvement of this osmoprotectants in a free radical scavenging mechanism. Taken together, our results indicate a probable role of osmolytes in co-operation with antioxidative enzymes in lowering pesticide induced oxidative stress.