Journal of Pure and Applied MicrobiologyVol. 4 No. 2

Antibacterial Activity of Purple non Sulphur Bacteria against Vibrio spp., Associated with Diseased Shrimp

R. Chandrasekaran and G.V. Ashok Kumar*

PG and Research Department of Botany and Microbiology, AVVM Sri Pushpam College (Autonomous), Poondi, Thanjavur - 613 503, India.

Received on 12 January 2010 and accepted on 24 February 2010



The antibacterial activity of organic solvent extracts from purple non sulphur bacteria (PNSB), isolated from shrimp culture ponds, showed inhibitory activity against the growth of, Vibrio spp., isolated from infected Tiger prawn (Penaeus monodon).The antibiotic activity was studied by Disk diffusion method and Broth tube dilution method. Amongst the purple non sulphur bacterial isolates Rhodobacter sphaeroides showed antagonism against Vibrio harveyi, Vibrio fischeri ,and Vibrio alginolyticus, with an minimum inhibitory concentration (MIC) range of 0.39- 6.25mg/ml. The chloroform extracts showed highest inhibitory zones than other solvents. These results reveal that extracts from the PNSB strains may hold novel bioactive compounds with effective antimicrobial properties

Keywords : Purple non sulphur bacteria, Antimicrobial activity, Shrimp pond, Vibrio harveyi.