Optimization of fermentation conditions for trehalose synthase production by Escherichia coli using response surface method

The fermentation medium composition of Trehalose synthase gene engineering bacteria E.coli BL21 ( p ET15b-Tre S) were optimized for bacteriocin production.The conversion rate of trehalose synthase was used as evaluation index.Firstly, the effects of the single factors on bacterioc in production from strain E.coli BL21 ( p ET15 bTre S) were examined. To obtain the best producing trehalose synthase medium, three key factors influencing the trehalose synthase production: glucose, yeast extract powder and K2HPO4, were determined by Plackett-Burman design experiment.And then response surface methods were applied.Results showed that the best culture media component for the fermentation by E.coli were: glucose 7.2g / L, yeast extract powder 6.6g / L, peptone 10 g / L, ( NH4) 2SO45g / L, K2HPO415.7g / L, KH2PO44 g / L, Mg SO4·7H2O 1.6g / L, mixture of microelement 0.5m L / L. Under this conditions the enzyme activity was 65 U / mg, increased 91.2%.