胶质芽孢杆菌突变株021120的培养条件及发酵工艺优化

对离子束诱变所获得的突变菌株021120进行了培养条件和发酵工艺研究。单因子及正交试验结果表明，碳源对生物量和芽孢形成的影响最大，其次是氮源，磷和钾的影响较小；添加CaCO3和增加氧通量显著促进芽孢的形成。发酵培养基的理想配方为：2%淀粉、0.4% 酵母、0.1% K2HPO4、0.1％ MgSO4·7H20、0.5 ％CaCO3，pH 7.5。种子菌经二级扩大培养后，按6％的接种量接入70 L发酵罐，在32℃进行发酵，氧通量2.0-2.5 vvm，培养周期38-42 h，芽孢量达到9.80×108 cfu ml-1。通过以上培养基和发酵条件的优化，有效控制了多糖荚膜的产生，并促进了芽孢的形成，获得合格产品。

Optimization of Fermentation Conditions of Bacillus mucilaginosus Mutant 021120

Fermentation conditions for the production of spores of Bacillus mucilaginosus mutant 021120 were optimized through the single factor and orthogonal experiments. The results showed that the biomass and formation of spores were obviously affected by carbonate, followed by nitrogen. Addition of CaCO3 and enhancing air flux notably promoted the formation of spores. The optimal culture medium was composed of 2% starch, 0.4% Yeast, 0.1% K2HPO4, 0.1％ MgSO4·7H20 and 0.5 ％CaCO3, pH7.5. 6% of the inoculum prepared with two-stage extensive culture was inoculated into a 70L fermentor. The fermentation was carried out with 2.0-2.5 vvm of air flux at 32℃ for 38-42h, and the spores of 9.80×108 cfu ml-1 was obtained. Under these optimal fermentation conditions, the capsule was successfully controled and the formation of the spores was effectively improved, thus the satisfying bacteial product was obtained.