为了提高重组大肠杆菌(Escherichia coli BL21DE3)(pET-28a(+)-bgl)发酵产β-1,3-1,4-葡聚糖酶的能力,研究了发酵培养基中各类碳源及氮源的影响,并通过响应面分析法优化培养基各组分的含量。结果表明,甘油为最适碳源,酵母粉及胰蛋白胨为氮源。优化的培养基组成是:yeast extract终浓度为20 g/L,胰蛋白胨12.5 g/L,甘油14.1 mL/L,KH2PO42.17 g/L,K2HPO42.74 g/L。三角瓶发酵产β-葡聚糖酶酶活(2 978.2 U/mL),与初始培养基(1 671.9 U/mL)相比,提高了1.78倍。研究结果表明,发酵培养基的优化对重组大肠杆菌发酵生产工业酶具有重要作用。

Terrific Broth(TB) medium was proved to be the optimum medium for β-1,3-1,4-glucanase fermentation using recombinant Escherichia coli.Several factors including 10 carbon sources and 9 nitrogen sources were studied in order to improve the productivity of β-1,3-1,4-glucanase by recombinant E.coli BL21DE3(pET-28a(+)-bgl).And glycerin,yeast extract and tryptone were finally selected as the best carbon source and nitrogen sources,respectively.Response surface methodology(RSM),fractional factorial design(FFD),steepest ascent path,and central composite design(CCD) were used to determine the optimum concentrations of each component in TB medium.Finally the concentrations were determined as follows: yeast extract 20 g/L,tryptone 12.5 g/L,glycerin 14.1 mL/L,KH2PO4 2.17 g/L and K2HPO4 2.74 g/L.And activity of β-1,3-1,4-glucanase achieved 2978 U/mL,which was 1.78 times higher than that from original medium.These conclusions will provide theoretical basis for the pilot scale fermentation and further utilization of the β-1,3-1,4-glucanase in industry.