Effect on alpha-amylase production by employing polyethylene glycol at different concentrations in medium.

摘要

Various bacteria were compared for their ability to produce alpha-amylase, and the effects of PEG 4000 were investigated on alpha-amylase production and recovery from crude extract, concentrate and ultra-filtrate. Bacillus amyloliquefaceins was found to be a better alpha-amylase producer than B. subtilis. Medium containing 7 and 2% PEG demonstrated 30x higher alpha-amylase activity than medium without PEG. In addition, 2% PEG was more effective than 7% PEG. Highest concn. of alpha-amylase (2690 U ml-1) was found in the sample concentrate, which was much higher than that of the original sample (260 U m-1). Theoretically, the ultra filtrate should not contain any amylase activity, but in this study it demonstrated an alpha-amylase activity of 89 U ml-1. Results suggest that B. amyloliquefaceins is the best bacterial strain to produce max. quantities of alpha-amylase in the medium containing 2% PEG.