Production of α-Glucosidase Inhibitor and 1-Deoxynojirimycin by Bacillus subtilis MORI

Abstract

Galactose and soybean meal were selected as the best carbon and nitrogen sources, repectively, for the efficient production of α-glucosidase inhibitor (AGI) and 1-deoxynojirimycin (DNJ) by a newly isolated Bacillus subtilis MORI. The optimal concentrations of the galactose and soybean meal for the production of AGI and DNJ were investigated by response surface methodology. For the production of AGI, the optimal galactose and soybean meal concentrations were 4.3% (w/v) and 3.2% (w/v), respectively, and for DNJ, 4.5% (w/v) and 3.0% (w/v), respectively. The nearly identical optimal concentrations of galactose and soybean meal for the production of both AGI and DNJ indicated a close correlation between the production of AGI and DNJ. The maximum production of AGI (50,880 GIU/ml) and DNJ (824 μg/ml) obtained from the statistically optimized medium in a jar fermenter was 2.33 and 2.38-fold, respectively, higher than those (21,798 GIU/ml and 346 μg/ml, respectively) of the pre-optimized medium. The production of both AGI and DNJ was greatly increased by jar fermentation (AGI of 38,524 GIU/ml and DNJ of 491 μg/ml) compared with flask fermentation.