食品科学 ›› 2018, Vol. 39 ›› Issue (12): 185-190.doi: 10.7506/spkx1002-6630-201812029

• 生物工程 • 上一篇    下一篇

拮抗砀山梨炭疽菌的内生菌筛选及抑菌效果分析

郭志华,段腾飞,江翠翠,王芳   

  1. (宿州学院生物与食品工程学院,安徽?宿州 234000)
  • 出版日期:2018-06-25 发布日期:2018-06-15
  • 基金资助:
    宿州学院高校优秀青年人才支持计划重点项目(2016XQNRL005); 安徽省高校优秀青年人才支持计划项目(gxyq2018101);宿州区域发展协同创新中心项目(2016szxt04)

Isolation of Endophytic Bacteria from Dangshan Pear and Their Antagonistic Effect against Colletotrichum gloeosporioides

GUO Zhihua, DUAN Tengfei, JIANG Cuicui, WANG Fang   

  1. (School of Biological and Food Engineering, Suzhou University, Suzhou 234000, China)
  • Online:2018-06-25 Published:2018-06-15

摘要: 从健康砀山梨中分离出15 株内生菌,筛选出1 株对砀山梨胶孢炭疽菌抑菌活性较高的菌株,命名为DSL-9,初步鉴定为枯草芽孢杆菌(Bacillus subtilis)。DSL-9菌株对炭疽菌的抑制主要是通过胞外分泌物作用的结果。采用硫酸铵沉淀法获得DSL-9的粗蛋白提取液,蛋白提取液在30~60?℃抑菌率无明显变化,大于60?℃抑菌率下降;在pH?7~10区间抑菌活性较高,且无明显变化;紫外线对抑菌物质无明显影响;蛋白提取液经蛋白酶处理后,抑菌活性下降。研究内生菌DSL-9对感染炭疽菌砀山梨防御酶活性的影响,发现内生菌DSL-9可提高砀山梨果实对病菌的抗性。从砀山梨中分离筛选的枯草芽孢杆菌DSL-9?对砀山梨炭疽病害的生物防治具有潜在的应用价值。

关键词: 砀山梨, 内生菌, 胶孢炭疽菌, 防御酶

Abstract: In this study, 15 strains of endophytic bacteria were isolated from healthy Dangshan pear. Out of these, one isolate, designated DSL-9, was screened for its strong inhibitory activity against Colletotrichum gloeosporioides. This strain was tentatively identified as Bacillus subtilis based on its morphological characteristics and 16S rDNA sequence. The results showed that the antifungal effect of strain DSL-9 was mediated mainly by the extracellular compounds secreted by it. A crude protein extract from DSL-9 was obtained by ammonium sulfate precipitation. The antifungal activity of the extract was not significantly changed at 30–60 ℃ but was decreased at temperatures higher than 60 ℃. In the pH range of 7 to 10, high antifungal activity was obtained without significant changes. Ultraviolet (UV) light had no significant influence on the antifungal extract. After protease treatment, the antifungal activity was declined. DSL-9 could improve resistance to C. gloeosporioides in Dangshan pear as reflected by its effect on defense enzyme activities in infected pear fruits. B. subtilis DSL-9 will have potential application in biological control of C. gloeosporioides in Dangshan pear.

Key words: Dangshan pear, endophytic bacteria, Colletotrichum gloeosporioides, defense enzymes

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