Production of Alcaligenes faecalis penicillin G acylase in Bacillus subtilis WB600 (pMA5) fed with partially hydrolyzed starch

摘要: In this study, a recombinant strain Bacillus subtilis WB600 (pMA5) was used to produce Alcaligenes faecalis penicillin G acylase (PGA). The PGA activity and overall productivity were respectively 378 7.13 U/l h in batch culture using complex medium containing 25 g/l of soluble starch. Fed-batch cultures indicated that glucose had negative effect on the production PGA. Starch is good carbon source, but it could not be directly as feed due high viscosity after heat sterilization. A prepared by limited hydrolysis starch with small amount α-amylase, which greatly improved fluidity little formation glucose. increased 546 feeding partially hydrolyzed When mixture Tryptone added pH-stat strategy, reached 1960 U/l, over five-fold obtained culture, 19.6 h, more than two-fold culture.