STEPWISE INTRODUCTION OF REGULATORY GENES STIMULATING PRODUCTION OF ALPHA-AMYLASE INTO BACILLUS-SUBTILIS - CONSTRUCTION OF AN ALPHA-AMYLASE EXTRAHYPER PRODUCING STRAIN

The production of extracellular a-amylase in Bacillus subtilis is probably regulated by many genetic elements, such as amyR, tmrA7, pap, amyB and sacU. Additional genetic elements, C-108 and A-2 for production of the a-amylase were found in D-cyc1oserine and ampicillin resistant mutants (C108 and A2) of B. subtilis 6160, respectively. Strain C108 increased the production of a-amylase about 5 times and protease about 80 times compared to parental 6160 strain. Strain A2 showed a nearly 6-fold increased a-amylase production. These genetic elements displayed a synergistic effect with other genetic factors in production of extracellular a-amylase when these elements were transferred by DNA mediated transformation. By stepwise introduction of these and other genetic elements into B. subtiIis 6160 by transformation and mutation, strains with higher a-amylase producing activity were obtained. The finally obtained strain, T2N26, produced about 1,500 - 2,000 times more (lamylase than parental 6160 strain. © 1979 Taylor & Francis Group, LLC.