To explore the optimal fermentation conditions and biocontrol efficacy of Bacillus amyloliq-uefaciens SH-53,single-factor and response surface tests were designed and performed to optimize the fermentation condition with the OD600nm 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 seed-lings and effect on the activity of root defense enzymes were tested using pot experiments in the labora-tory.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,Na-NO3 15.00 g/L,Na2HPC4 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 OD600nm 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 opti-mal fermentation broth could significantly improve the plant height,stem diameter,root length and oth-er agronomic traits.In addition,the activities of peroxidase,catalase,polyphenol oxidase and superox-ide dismutase also increased in tomato roots.The colonization amount of strain SH-53 on the root sur-face of tomato seedling was 1.25x108 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.
关键词
解淀粉芽胞杆菌/发酵条件优化/番茄枯萎病/根系定殖/根系防御酶
Key words
Bacillus amyloliquefaciens/optimization of fermentation condition/tomato Fusarium wilt/root colonization/root defense enzyme
维普
万方数据