Abstract

Bacterial colonies were obtained from water samples collected from sea-coast of Machilipatnam, Andhra Pradesh in South India. The isolates were cultured, named as M1, M2, M3 etc., and screened for antibacterial action. Among the 40 representative isolates obtained, three isolates showed substantial antibacterial activity with more than 10 mm of zone of inhibition against two test bacteria used in preliminary screening. These three isolates marked as M20, M22 and M23 showed most outstanding results against all the test bacteria used in further testing of antibacterial activity. The isolate M20 showed the highest activity with a zone of inhibition of 1a6mm against Serratia marcescens, 14 mm against E.coli and Shigella, and with 12 mm against Salmonella paratyphi and Bacillus cereus. The isolates M20, M22 and M23 were analyzed for their morphological, biochemical and physiological characteristics and tentatively identified as Alcaligenes sp. (M20), Bacillus sp. (M22) and Bacillus sp. (M23) from the performed biochemical tests.

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