Abstract:

The fermentation conditions for producing α-glucosidase inhibitor by an endophyte named Bacillus cereus SD6
were optimized using response surface methodology in the present study. The results of Plackett-Burman experiments
showed that glucose concentration, rotation speed and temperature had significant effects on the inhibition of α-glucosidase
by fermentation liquid, with more than 90% confidence. Bex-Behnken experiments were applied for the optimization of the
fermentation conditions through response surface analysis. The optimal conditions for glucose concentration, rotation speed
and fermentation temperature were determined as 48.05 g/L, 200.44 r/min and 27.42 ℃, respectively. Under these fermentation
conditions, the maximum predicted inhibitory rate of the fermentation liquid against α-glucosidase was 39%, agreeing with the
experimental value of 38.52%. The good consistency indicated the feasibility of the developed prediction model.

Key words: response surface methodology, α-glucosidase inhibitors, endophyte