香蕉枯萎病拮抗菌CL-1筛选及发酵条件优化

    Screening of antagonistic bacteria CL-1 against banana wilt disease and optimization of fermentation conditions

    • 摘要: 从未发病蕉园根际土壤中分离菌株,以香蕉枯萎病病原菌(Fusarium oxysporum f. sp cubense Tropical Race 4, Foc TR4)为靶标菌,筛选Foc TR4高效拮抗菌株,为香蕉枯萎病绿色防控提供新选择。采集华侨大学园艺温室香蕉园根际土壤,采用稀释涂布和平板对峙法,筛选优良拮抗菌株,并对其进行培养条件优化。结果表明:从蕉园土壤中共分离拮抗菌株3个,其中CL-1菌株拮抗效果最佳,抑菌率达到34.25%,16S rRNA测序结果表明该菌株与Stenotrophomonas maltophilia相似性达到99.38 %,初步鉴定为嗜麦芽窄食单胞菌。对菌株CL-1进行单因素培养条件优化, CL-1菌株的最适培养基为牛肉膏5 g·L−1,蛋白胨10 g·L−1,氯化钙5 g·L−1,优化后抑菌率提高至45.21%。CL-1菌株能够较好抑制香蕉Foc 4生长,具有良好的生防潜力。

       

      Abstract: Microbial strains were isolated from the rhizosphere soil from banana orchard without Fusarium oxysporum f. sp cubense Tropical Race 4(Foc TR4)infection, providing a new option for green prevention and control of banana wilt disease. Rhizosphere soil from banana orchards in Huaqiao University greenhouse was collectted, and dilution coating and plate confrontation methods was used to screen for excellent antagonistic strains, and optimize the growth conditions. The results showed that three antagonistic strains were isolated, among which CL-1 strain had the best antagonistic effect, with inhibition rate of 34.25%. The 16S RNA sequencing results indicated that the strain had a similarity of 99.38% with Stenotrophomonas maltophilia, and was preliminarily identified as Stenotrophomonas maltophilia. Single factor cultivation conditions were optimized for strain CL-1, and the optimal culture medium for CL-1 strain was beef extract 5 g·L−1, peptone 10 g·L−1, and calcium chloride 5 g·L−1. After optimization, the inhibition rate increased to 45.21%. The CL-1 strain can effectively inhibit the growth of banana Foc TR4 and has good biocontrol potential.

       

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