植物内生细菌MY1的发酵条件优化及其抑菌物质稳定性分析

Analysis on Optimization of Fermentation Conditions and Stability of Antimicrobial Substances of Endophytic Bacterial Strain MY1

从曼陀罗叶片中获得的植物内生细菌MY1对多种植物病原菌具有良好的抑菌活性。为进一步开发和利用植物内生细菌MY1,分别采用单因素试验法和正交试验法,优化MY1菌株培养基成分和培养条件。结果表明,菌株MY1的最佳基础培养基为BPY培养基;最优碳源为乳糖,最优氮源为酵母粉和牛肉膏混配;最佳发酵条件为培养温度28℃,转速160 r/min,发酵时间96 h,接种量2%,装液量100 mL/500 mL,pH值9.0;菌株MY1的抑菌物质具有较好的热稳定性和酸碱稳定性,并且对紫外光和自然光照射不敏感,可以耐受较长时间贮存。试验结果可为后续内生细菌MY1生防制剂的开发提供理论依据。

An endophytic bacterium strain MY1 with good antifungal activity against a variety of plant fungal pathogen was obtained from the leaves of Datura stramonium.To further develop and utilize the endophytic bacteria MY1,single factor and orthogonal test were used to optimize the composition of the medium and the culture conditions of MY1strain.The results showed that the optimal basal medium was BPY,the optimal carbon source was lactose,and the optimal nitrogen source was mixing of yeast powder and beef extract.The optimal fermentation conditions were as follows:the temperature 28℃,rotate speed 160 r/min,fermentation time 96 h,inoculum 2%,volume 100 mL/500 mL,initial pH was 9.0.The antifungal components of MY1 had a broad adaption range to pH value and were stable under high temperatures,visible light and UV-treatment,and can be stored for a long time.This study result will provide a theoretical foundation for the development of endophytic MY1 biocontrol.