Biodegradation of Azo Dye by Listeria Sp

Abstract

In this study azo dye degrading bacteria was isolated from various textile industries in and around Rajapalayam. The four bacterial strains effectively degrading the textile dyes were isolated, screened and analyzed. The toxic level of the dye and its metabolites were successfully estimated and it was found that the concentration of the protein in the culture increases with the increase in the concentration of the dye. Thus the stress is the main reason for the production of protein which in tum responsible for degradation. Phytotoxicity study was conducted in rice seed and monitoring the germination and growth rate of the seed. The results indicated that the growth of the plant is arrested when the seeds are soaked in the dye. Seed germination of the rice have a very low growth and germination rate with respect to the concentration of the dye and the degraded products showed higher in toxic level. This confirms the formation of toxic aromatic amines. Finally biochemical analysis was done for the identification of the bacterial strains responsible for the degradation of the dyes. Among the four screened isolates Listeria sp., was found to be more effective.