Response surface methodology used for statistical optimization of jiean-peptide production by Bacillus subtilis cells adsorbed on wood chips

Abstract

Response surface methodology (RSM) was used for statistical optimization of jiean-peptide (JAA) production by Bacillus subtilis ZK8 cells adsorbed on wood chips to form a novel fermentation system. The Plackett-Burman design was used in the first step to evaluate the effects of eight factors, including six fermentation medium components and two cell adsorption conditions. Among the variables screened, soybean meal hydrolysate (SMH) and MgSO₄·7H₂O in the fermentation medium had significanteffects on JAA production. In the second step, the concentrations of SMH and MgSO₄·7H₂O were further optimized using central composite designs and response surface analysis. The optimized concentration of SMH and MgSO₄·7H₂O was 24% (v/v) and 0.38% (w/v), respectively, which increased the production of JAA in a shake flask system by 41% relative to optimization of a single variable component of the culture medium.