Induction and catabolite repression of alpha-amylase synthesis in Bacilluslicheniformis SKB4

Abstract

Microbial amylases have an exciting potentiality and are being used extensively in different industries. In this study, regulation of amylase biosynthesis was examined in Bacillus licheniformis SKB4 (wild type) and its mutant strain (8b). The mutant strain was developed by using UV exposure. Expression of the a-amylase gene of Bacillus licheniformis was activated by inducer and subject to catabolite repression. Addition of exogenous glucose or sucrose repressed bio-synthesis of a-amylase which was concentration (0.05-1.0% w/v) dependent. However, mutant strain could enable to overrule the glucose mediated repressive effect. Supplementation of second messenger like cyclic adenosine 3',5'-monophosphate (cAMP, 5 mM) along with glucose could a little bit improve amylase synthesis in wild strain. Antibiotics like rifampicin and tetracycline (ribonucleic acid and protein synthesis inhibitor; 100mg/ml) had stopped the release of enzyme in both wild and mutant strain. Amylase production was also inhibited in presence of respiratory inhibitor 2,4-dinitrophenol (uncoupler) at (5mM) concentration. Thus, the pattern of regulation of a-amylase production in the present strain was in multiple forms; it showed the classical glucose effect without stimulation of second messenger system.