Optimization, production and partial purification of extracellular α- amylase from Bacillus sp. marini

The aim of the current study was to isolate amylase producing bacteria from the soil samples collected from marine environment of Andaman and Nicobar Islands, India. The isolation was performed by serial dilution and plating method. Total 35 bacteria were isolated from the collected soil samples. All isolates were screened for amylolytic activity by starch agar plate method, among 35 bacterial isolates only 4 isolates showed the amylolytic activity, one isolate was selected for further study. The isolate (potential strain) was identified as Bacillus sp. marini by microscopic, biochemical and molecular experiments. The best enzyme activity was observed at pH 7 and temperature 40°C, 5.5% NaCl concentration, starch as carbon source and yeast extract as nitrogen source. At the optimum conditions B. sp. marini produced 8000 U of amylase per litre of culture broth, which is 3 fold higher than before optimization.