居间驹形氏杆菌发酵大豆糖蜜生产细菌纤维素条件的优化

Optimization of Bacterial Cellulose Production by Fermented Soybean Molasses with Komagataeibacter intermedius

通过居间驹形氏杆菌(Komagataeibacter intermedius CGMCC12562)发酵生产细菌纤维素,以大豆糖蜜作主要发酵原料,优化发酵工艺参数,提高细菌纤维素产量。在单因素试验的基础上,筛选出对细菌纤维素产量影响较大的4个因素,即大豆糖蜜可溶性固形物含量、玉米蛋白粉、ZnSO_4及苹果酸添加量,并通过Design-Expert响应面分析对这4个因素进行优化,得到最优的培养基及发酵工艺为:大豆糖蜜可溶性固形物含量14.13°Brix、玉米蛋白粉添加量1.6%、ZnSO_4添加量0.11%、苹果酸添加量0.41%;在30℃、接种量10%、装料量16%、初始pH 6.0的条件下静置培养7d,细菌纤维素产量高达(15.68±0.82)g/L。

In this study,Komagataeibacter intermedius CGMCC12562was employed to produce bacterial cellulose(BC)from soybean molasses.The fermentation process was optimized to improve BC yield.Through one-factor-at-a-time experiments,the soluble solids content(SSC)of soybean molasses,and corn gluten meal,ZnSO4and malic acid were selected as the factors with a significant influence on BC production for optimization by response surface methodology.It was found that the optimized culture medium consisted of soybean molasses with an SSC level of14.13°Brix,1.6%corn gluten meal,0.11%ZnSO4and0.41%malic acid.The BC yield was as high as(15.68±0.82)g/L after7days of culture at30℃for in a250-mL conical flask containing16%of the medium with an inoculum size of10%at an initial pH of6.0under static cultivation conditions.