Effect of Desiccation on the Isozyme Profile of Antioxidative Enzyme Catalase in Cyanobacterium Lyngbya Arboricola

Lyngbya arboricola inhabiting the bark of Mangifera indica is known to survive desiccation for a long period. The possible role of the antioxidative enzyme catalase in providing tolerance to the cyanobacterium was studied in desiccated mats both in dark and light conditions. An increase in catalase activity was observed in growing and desiccated (dark, light) conditions. But the increase was upto160% in dark desiccated mats whereas it was only 50% in growing mats. The catalase isoforms were studied with the help of the antibody developed against catalase (anticatalase). The partial purification of the enzyme was carried out on FPLC, a gel filtration column chromatography after sequential precipitation with acetone. The isozyme profile of catalase showed that there was induction of new isoform in mats desiccated in dark in addition to the three isoforms present in the growing mats. These three isoforms were in their native state which was revealed by the immunodiffusion experiments. Residual enzyme activity followed by Quantitative precipitin assay also suggested that there was formation of a new isozyme in addition to those present in the freshly collected mats. There was inactivation of the two isoforms in mats desiccated in light condition which can be inferred from the thickness of the CBB R250 stained precipitin lines.