【摘要】 为探索解淀粉芽胞杆菌Bacillus amyloliquefaciens SH-53的优化发酵条件及其生防作用,以发酵液OD_600nm值和抑菌率为指标,设计单因素试验和响应面试验优化发酵条件,以室内盆栽试验检测优化发酵液对番茄枯萎病防效、番茄苗促生效果及根系防御酶活的影响,并测定菌株SH-53在番茄根系的定殖能力。结果显示:菌株SH-53优化后的发酵条件为蔗糖15.00 g/L、硝酸钠15.00 g/L、磷酸氢二钠5.25 g/L、酵母浸粉5.00 g/L、pH 7.5、温度30℃、转速200 r/min,装液量200 mL培养24 h;优化后SH-53发酵液OD_600nm值及抑菌率分别较优化前显著提升183.01%和14.06%;在保护试验和治疗试验中防效分别为84.44%和64.86%,能显著提高番茄苗株高、茎粗和根长等农艺性状,可增强番茄根系过氧化物酶、过氧化氢酶、多酚氧化酶和超氧化物歧化酶活性。菌株SH-53在番茄苗根系表面定殖量为1.25×10⁸ CFU/mm。表明解淀粉芽胞杆菌SH-53优化发酵后对番茄枯萎病防治效果良好,可在番茄植株根系定殖,促进植株生长。更多还原

【Abstract】 To explore the optimal fermentation conditions and biocontrol efficacy of Bacillus amyloliquefaciens SH-53,single-factor and response surface tests were designed and performed to optimize the fermentation condition with the OD_600nm and the inhibition rate as the indexes.The control efficacy of the optimized fermentation broth on tomato Fusarium wilt,the growth-promoting effect of tomato seedlings and effect on the activity of root defense enzymes were tested using pot experiments in the laboratory.The colonization ability of the strain SH-53 on tomato roots was also detected.The results showed that the optimal fermentation conditions of strain SH-53 were as follows:sucrose 15.00 g/L,NaNO₃ 15.00 g/L,Na₂HPO₄ 5.25 g/L,yeast extract 5.00 g/L,pH 7.5,30℃,200 r/min,cultured in 200 mL liquid for 24 h.After optimization,the OD_{600 nm} value and inhibition rate of the fermented broth of strain SH-53 were increased by 183.01% and 14.06%,respectively.The control efficacy of the optimal fermentation broth in the protection and treatment tests was 84.44% and 64.86%,respectively.The optimal fermentation broth could significantly improve the plant height,stem diameter,root length and other agronomic traits.In addition,the activities of peroxidase,catalase,polyphenol oxidase and superoxide dismutase also increased in tomato roots.The colonization amount of strain SH-53 on the root surface of tomato seedling was 1.25×10⁸ CFU/mm.The results indicated that Bacillus amyloliquefaciens SH-53 had good control efficacy on tomato Fusarium wilt after optimized fermentation,and it could colonize tomato roots to promote plant growth.更多还原