Patent ID: 7550281

Claim:
A process for production of alpha-a mylase from Bacillus subtilis strain AB101, deposit accession No. CGMCC No. 2740 comprising: a) culturing the Bacillus subtilis strain AB101 under batch fermentation conditions at a temperature of 33-45° C. in a medium comprising assimilable sources of carbon and nitrogen, phosphate, and salts of trace elements, where said medium has a pH of about 5-9 and a dissolved oxygen concentration of 5-40% of air saturation; b) performing a fed-batch step, wherein the concentration of the assimilable carbon source in the medium is kept in a range from 0.1 g/1 to 1 g/1 while maintaining continued growth of the cells, and the dissolved oxygen concentration is adjusted to 5to 40% by passing air into the fermentation broth, which comprises i) inducing the promoter by a heat shock at a temperature of 50 to 53° C. for 5 to 15 minutes when the culture density (A 600nm ) is greater than 3.0, followed by cooling to 37° C. thereby initiating the production of the alpha-amylase, and ii) continuously feeding in assimilable sources of carbon and nitrogen, phosphate, and salts of trace elements; and c) removing the Bacillus subtilis strain AB101 from the medium; wherein the Bacillus subtilis strain AB101 produces alpha-amylase with a productivity of over 600,000 alpha-amylase units per mL in a 10-14 hour period.