Characterization of Aeromonas hydrophila strains and their evaluation for biodegradation of night soil

Among 67 psychrotrophic bacterial isolates of Leh, India screened for produ ction of hydrolytic enzymes at 10 degreesC, four belonging to Aeromonas hyd rophila were characterized and evaluated for biodegradation of night soil. All strains produced metalloproteases on a variety of carbon and nitrogen s ources. Strains LA1 and LA15 also produced alpha -amylase and PC5 both alph a- & beta -amylase. No amylase was produced by PN7, however it produced lip ase. Casein and glucose induced maximum enzyme activity (protease and amyla se) in LA15 and PC5, respectively. In LA1, maximum induction of protease wa s observed with casein and of amylase with maltose. Corn oil/tributyrin ser ved as the best inducers for protease and lipase production by PN7. A. hydr ophila strains were found to be psychrotrophic with optimum growth and enzy me activity at 20 and 37 degreesC, respectively. Maximum biodegradation of night soil was observed by strain LA1 at 5-20 degreesC.