Production optimization of ?-amylase from Bacillus licheniformis

Abstract

Amylases are of great significance in present day biotechnology. They constitute 25% of the industrial market.To meet the industrial demand there is a need of production optimization of ?-amylase from the microbialsource. In the present study, an attempt was made to isolate thermophilic bacterial strain producingthermophilic and alkaliphilic ?-amylase. Among 23 isolates, isolate K7 gave maximum production of ?amylase, which was later identified as Bacillus licheniformis. The organism gave maximum production of ?amylase in medium containing g/l (w/v) beef extract 3.0, peptone 5.0 and starch 1.0%. Starch (1.75%, w/v) andpeptone (0.15%, w/v) were optimized to be best carbon and nitrogen sources for ?-amylase production fromBacillus licheniformis. Optimum production of the enzyme was observed when inoculated medium of pH 8.0was incubated at 50°C for 48 h of incubation time.Further during optimization of reaction conditions, theenzyme gave maximum activity with 0.1 M Tris HCl buffer of pH 8.0 when incubated at a reactiontemperature of 50°C for 10 min of incubation time. The enzyme showed high affinity towards starch (0.15%,w/v) as substrate. The thermophilic and alkaliphilic nature of the enzyme suggest its potential application instarch, detergent and textile industries