摘要
B18是一株对十字花科根肿病菌Plasmodiophora brassicae具有抑制作用的优良生防放线菌,其活菌以及发酵液都可抑制根肿病菌休眠孢子萌发。为提高其菌体量以及孢子萌发抑制率,本文以菌体生物量和发酵液抑制根肿病菌休眠孢子活性为指标,通过单因素试验和正交设计优化B18的发酵培养基组分以及培养条件。结果表明:B18最适发酵培养基(1L)为蔗糖20 g,大豆粉10 g,牛肉膏5 g,NaCl 2.5 g,CaCO32.0 g;且在初始pH 7.0,初始接种量3%~7%,装瓶量150 mL/250 mL,温度25~30℃,150~200 r/min下发酵72 h所得的发酵液对孢子萌发抑制率最高且菌体量最大。随后测定了发酵条件优化后的B18发酵液的热、酸碱、紫外线以及储藏稳定性。结果表明:B18发酵产物的热稳定性较差,40℃以上其抑菌活性随着温度的升高而降低;发酵液在酸性、中性以及弱碱性条件下稳定性较好,在强碱性条件下稳定性变差;发酵液对紫外线不敏感,有较好的稳定性;发酵液在4℃条件下更稳定,30 d时孢子萌发抑制率仍可达到61.58%,常温条件下不稳定,15 d后抑制率明显降低。
Antagonistic Zhihengliuella aestuarii B18 is an excellent biocontrol actinomycetes which can inhibit Plasmodiophora brassicae.The living bacteria and fermentation broth can inhibit the germination of dormant spores.In order to increase the biomass and the inhibition rate of B18,the biomass and the inhibitory activity of fermentation liquid against resting spores of rhizopus were used as indicators,and the media and cultural conditions of strain B18 were optimized by single factor tests and orthogonal design.The results showed that the optimum fermentation medium(1L)for B18 included 20 g sucrose,10 g soybean powder,5 g beef extract,2.5 g NaCl and 2.0 g CaCO3.When fermented at 25-30℃and 150-200 r/min for 72 h,with an initial pH 7.0,initial inoculum amount of 3%-7%and a medium volume of 150 mL in 250 mL flask,the largest volume of B18 and the highest inhibition rate could be achieved.The heat,acid,alkali,ultraviolet and storage stability of B18 fermentation broth were determined.The results showed that the thermal stability of B18 fermentation products was poor;the bacteriostatic activity decreased with increasing temperature after 40℃;the stability of fermentation broth under acidic,neutral and weak alkaline conditions was better;the stability of fermentation broth became worse under strong alkaline conditions;the fermentation broth was insensitive to ultraviolet light and had a strong UV stability;the fermentation broth was more stable under 4℃conditions,and the inhibition rate could reach 61.58%30 d after storage,unstable at room temperature and decreased obviously after 15 d.
作者
蒋欢
唐贵婷
吴朝君
张勇
彭玉梅
苏宇
赵冰峰
王旭祎
JIANG Huan;TANG Guiting;WU Chaojun;ZHANG Yong;PENG Yumei;SU Yu;ZHAO Bingfeng;WANG Xuyi(Southeast Chongqing Academy of Agricultural Sciences, Fuling 408099, China)
出处
《植物保护》
CAS
CSCD
北大核心
2021年第3期127-135,共9页
Plant Protection
基金
农业农村部麻类生物学与加工重点实验室开放课题(KL-IBFC-201905)
重庆市技术创新与应用发展技术专项重点项目(cstc2019jscx-gksbX0140)
重庆市自然科学基金(cstc2019jcyj-msxmX0637)。
关键词
根肿菌
生防菌B18
榨菜
发酵条件
发酵液
Plasmodiophora brassicae
antagonistic actinomycetes strain B18
mustard
fermentation conditions
fermentation broth
