Thermal stability of partially purified α-amylase produced by Brevibacillus borstelensis R1 from the coastal waters of Bay of Bengal, Visakhapatnam

Highest alpha-amylase activity of Brevibacillus borstelensis R1 was observed at 37 degrees C (6133+58U/ml). The alpha-amylase retained its activity after 10hrs exposure to 4 degrees C with negligible variations in its activity. Alpha-amylase have several applications in starch processing, desizing of textiles, paper sizing, detergent additive, bread improvement, ethanol production, sewage treatment, effluent treatment and other fermentation processes. Highest alpha-amylase activity was observed at 37 degrees C (6133 +/- 58U/ml), while the lowest at 70 degrees C (2360 +/- 40U/ml). Only 38.47% activity remained at 70 degrees C. Optimum temperature of partially purified enzyme was similar to the crude enzyme. Partially purified enzyme was tested for its stability (1-10hours) at temperatures ranging from 4 degrees C to 70 degrees C. At 20 degrees C it retained 34.2% activity, at 25 degrees C 44.1%, at 37 degrees C 34.7%, at 50 degrees C 56.2%, at 60 degrees C 38.2% and at 70 degrees C it retained 30.8% activity upon exposure for about 10 hrs.