Bacterial strain isolated from different sources of Burdwan town and their potentiality towards decolouration of azo and non-azo dyes

Abstract

Microorganisms play a remarkable role in decomposition and mineralization of various azo dyes. Bacterial decolorization of azo dyes has gained importance in recent times as they are easy to cultivate and grow quickly. The aim of the present study is to evaluate the potentiality of bacterial strain isolated from Burdwan municipal waste dumping centre, automobile sludge and drain water to decolourise azo and non-azo dyes (Congo red, methyl orange and methylene blue). The study of biochemical test of isolated strain-1 and strain-3 showed positive results for gelatin hydrolysis, citrate utilization, methylene blue and catalase whereas negative results recorded for Indole and voges-proskaur test. On the other hand staining showed positive results for endospore, capsule and gram’s staining. But negative results was obtained for acid fast. The study of biochemical test of isolated strain-2 showed positive result for only catalase and methylene blue. Whereas negative results was recorded for gelatin agar hydrolysis, citrate utilization, indole and voges-proskaur test. The dye accumulation study revealed that all the bacterial strain (1, 2 and 3) showed higher percentage of dye accumulation at 20 mg/l followed by 5mg/l and lowest at 10 mg/l for methyl orange. Almost similar results were recorded for Congo red. All the three strain showed good dye accumulation percentage at higher concentration (20 mg/l), but strain-2 and 3 showed higher accumulations at 5 mg/l and 10 mg/l, respectively. On the other hand strain-1 showed higher performance for dye accumulation at lower concentration (5 mg/l) followed by 20mg/l and 10mg/l for methylene blue after 24h of incubation. Genotoxicity study suggests that there is no abnormality during cell division of Allium Cepa with dyes after twenty four hours of inoculation with dye and isolated microbes.