Isolation, biochemical and molecular characterization of strains of coliforms from the water sample collected from Shivnath river

Abstract

Coliform bacteria include organisms like Escherichia coli, Enterobacter sp., Klebsiella sp. and Citrobacter sp.and are gram negative, facultative anaerobic, non-sporulating and lactose fermenting organisms. E. coli is used as the indicator organism for detection of faecal contamination of water. Conventional methods for the detection of Coliforms in water include microbial culture technique in lactose containing media, Biochemical characterization, study of cell morphology, colony morphology etc. These methods are time consuming with limited specificity. DNA based molecular techniques like 16S rRNA gene sequencing is highly specific. In this research work, the16S rRNA gene sequencing technique was used to characterize the two isolates from water samples of Shivnath River after the above said preliminary tests were conducted. The two strains of coliforms identified by this technique were Escherichia coli strain GA and Enterobacter cloacae strain AB6.