梨树内生拮抗细菌的筛选及发酵条件的研究

Screening and Study on Fermentation Conditions of Endophytic Antifungal Bacteria Isolated from Pear Plant

以梨黑斑病菌(Alternaria alternata)为指示菌,从梨树木质部分离的8株内生芽孢杆菌中筛选出一株抑菌效果最佳的拮抗菌株LP5。为明确该菌株在发酵生产中的最佳营养组分及发酵条件,运用单因素试验和正交试验方法测定了不同因素下LP5菌株发酵液的OD600值及其抑菌作用。研究结果表明:最有利于菌体生长及抗菌物质积累的营养条件是以含蔗糖1.5%,蛋白胨1.0%,酵母粉0.5%,NaCl 0.5%的液体培养液,最适发酵条件为30℃,pH 7.0,发酵培养48 h^72 h。

With Alternaria alternata as indicator, the strain LP5 was screened from eight strains of endophytic Bacil- lus sp. , which were isolated from xylem of pear plant. To confirm the optimal corrlponents and cultural conditions of strain LP5, the antifungal activity and 00600 of the strain LP5 were studied by the method of single factor and orthogonal design. Results showed that the optimal cultural liquid medium was composed of 1.5% sucrose, 1. 0% protein peptone, 0.5% gyeast extract, 0.5% NaCI, and the optimal fermentation conditions were 30 ℃, pH 7.0 and culturing for 48～72 h.