枯草芽胞杆菌262XY2x固体发酵条件优化及对马铃薯炭疽病的防治效果

本试验以枯草芽胞杆菌262XY2x为目标菌，通过单因素分析与正交组合试验，筛选其固体发酵基质，优化发酵条件，并对其进行防病促生作用测定。结果表明，枯草芽胞杆菌262XY2x固体发酵最佳培养基配方为：麸皮36.4%、稻壳粉31.8%、玉米面18.2%、豆粕13.6%、乳糖1.0%、尿素1.1%和ZnSO₄ 0.11%；最优发酵条件为：接种量10%，固料添加量44 g/L，料水比1:1.4，发酵温度28℃，发酵初始pH 7.0，发酵时间40～44 h，活菌数可达7.13×10¹⁴ CFU/g。该菌剂用量为1.0%时，马铃薯株高和根长显著高于对照（P<0.05），增长率分别为45.25%和28.43%，体内PAL活性较对照显著增加（P<0.05），增长率为16.57%，且对马铃薯炭疽病的预防效果为63.45%，治疗效果为46.70%。

Optimization of Solid Fermentation Conditions of Bacillus subtilis 262XY2x and Its Control Effect on Colletotrichum coccodes

Bacillus subtilis 262XY2xwas used as antagonistic bacteria in this experiment. The solid fermentation matrix of B. subtilis 262XY2x was screened by one-way analysis of variance (ANOVA) and orthogonal combination test, optimized the fermentation conditions and the function of disease control and promoting growth were determined. The results showed that the optimal medium for solid fermentation of B. subtilis 262XY2x contained bran (36.4%), rice hull powder (31.8%), corn gluten (18.2%), soybean meal (13.6%), lactose (1.0%), urea (1.1%) and ZnSO₄ (40.11%). The viable amounts was up to 7.13×10¹⁴ CFU/g in the optimal fermentation conditions which contained inoculum 10%, solid content 44 g/L, feed water ratio 1:1.4, fermentation temperature 28℃, fermentation initial pH was 7.0 and fermentation time was 40-44 h. When the dosage of the microbial agent was 1.0%, the plant height and root length of the potato were significantly higher than that of the control (P<0.05), and the growth ratios were 45.25% and 28.43%, respectively. The PAL activity in the potato was significantly increased compared with the control (P<0.05) 16.57%, and the preventive effect on Colletotrichum coccodes and the therapeutic effect were 63.45% and 46.70%.