Abstract:
In this study, a combination of Serratia nematophila L2 and Bacillus velezensis W24 was used to biocontrol Sclerotinia sclerotiorum. When the mixed ratio of L2 to W24 was 1:1, the inhibition rate on the growth of S. sclerotiorum was 88.1 %. To gain a large number of bacteria, the culture medium and conditions were optimized. When the medium formula involved molasses (8.890 g/L), soy peptone (6.826 g/L), and NaCl (6.865 g/L), and the culture conditions were 32 °C, inoculum 4%, rotation speed 200 rpm, and pH 7, the maximum amounts of bacterial cells obtained. In order to prepare microcapsules, spray drying conditions were optimized. These conditions included the soluble starch concentration of 30 g/100 mL, the inlet air temperature of 160 °C, and the feed flow rate of 450 mL/h. Under these optimized conditions to prepare microcapsules, the mixed strain (L2 and W24) exhibited a survival rate of 93.9 ± 0.9% and a viable bacterial count of 6.4 × 1012 cfu/g. In addition, microcapsules (GW24Ms) which contained strains L2 and W24 had good storage stability. In the pot experiment, GW24Ms could effectively reduce the disease of soybean plants and the control effect was 88.4%. Thus, the microbial agent represents a promising biocontrol solution for managing Sclerotinia in soybean.
摘要:
在这项研究中,使用嗜线虫沙雷氏菌L2和维氏芽孢杆菌W24的组合来生物防治菌核病。当L2与W24的混合比例为1:1时,对菌核病菌生长的抑制率为88.1%。为了获得大量的细菌,培养基和条件进行了优化。当培养基配方为糖蜜(8.890g/L)时,大豆蛋白胨(6.826g/L),和NaCl(6.865g/L),培养条件为32℃,接种物4%,转速200转/分,和pH7,获得的细菌细胞的最大量。为了制备微胶囊,优化了喷雾干燥条件。这些条件包括可溶性淀粉浓度为30g/100mL,进气温度为160°C,进料流速为450mL/h。在这些优化条件下制备微胶囊,混合菌株(L2和W24)的存活率为93.9±0.9%,活菌数为6.4×1012cfu/g。此外,含有菌株L2和W24的微胶囊(GW24Ms)具有良好的储存稳定性。在锅实验中,GW24Ms能有效减轻大豆植株病害,防治效果达88.4%。因此,微生物剂代表了一种有前途的生物防治解决方案,用于管理大豆中的菌核病。