Optimization of riboflavin production by recombinant Bacillus subtilis X42 using statistical designs

摘要

A sequential optimization strategy, based on statistical experimental designs, was used to enhance the production of riboflavin by recombinant Bacillus subtilis X42. The two-level Plackett-Burman (PB) design was implemented to screen medium components that significantly influence riboflavin production. Among the 11 variables tested, glucose, yeast powder, MgSO_4·7H_2O, urea, CuCl_2, MnCl_2 were identified as the most significant factors (confidence levels above 95%) for riboflavin production. The selected significant parameters such as yeast powder, urea and CuCl_2 were further optimized using a central composite design. The optimum medium was (in g/L): yeast powder, 20.8; urea, 4.8; CuCl_2, 0.024; glucose, 100; MgSO_4·7H_2O, 0.5; K_2HPO_4, 0.5; KH_2PO_4, 1; FeCl_2, 0.02. The optimum medium led to a maximum riboflavin concentration of 7.9 g/L in shake flasks, which was 11.2% higher than the control medium.