Abstract: Bacillus subtilus WSH-062 could produce extracellular poly (vinyl alcohol) (PVA)-degrading enzyme (PVAase) in the flask culture. Optimization of culture conditions was carried out through mono-factor and orthogonal experiments. The results showed that the enzyme produced by this strain was an induced enzyme. The mixed nitrogen sources (the ratio of NaNO3 to yeast extract was 1:1) with concentration of 2 g/L were favorable for cell growth and enzyme synthesis. The results of orthogonal experiment showed that the optimal fermentation conditions were: PVA 30 g/L，yeast extract 8.2 g/L，NaNO3 10.1 g/L，MgSO4·7H2O 0.35 g/L and KH2PO4 3 g/L at pH 7.2. Under this condition，the maximal PVAase activity was about 5.0 U/mL，which was increased by 4.75-fold compared with the value before optimization.

摘要： 枯草芽胞杆菌WSH-062在摇瓶培养中能产生胞外的PVA降解酶。通过单因素及正交实验对其进行了发酵条件的优化。研究结果表明：该菌产生的PVA降解酶为诱导型酶；2 g/L的复合氮源（NaNO3和酵母粉的配比为1∶1）就能满足细胞生长和产酶的营养需要。正交实验分析得到最优的发酵培养基为：PVA 30 g/L，酵母粉12.2 g/L，NaNO3 10.1 g/L，MgSO4·7H2O 0.35 g/L，KH2PO4 3 g/L，pH值7.2。优化之后的PVA降解酶酶活达到5.00 U/mL，比优化前提高了4.75倍，并且重复性较好。