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沙雷氏菌属(Serratia sp.)中的许多菌株是一些昆虫的机会致病菌,具有一定的杀虫活性。本研究通过从患败血症的松墨天牛(Monochamus alternatus Hope)尸体中分离出一株BRC-CXG2菌株(KT366770),并对该菌株进行形态学鉴定、16S r DNA系统发育分析、生理生化反应、药敏分析以及生物测定。结果表明,分离的菌株BRC-CXG2属于沙雷氏菌属的一种新种,且对头孢哌酮、头孢噻肟、头孢他啶等常见药物具有不同程度的敏感性,其中提取的灵杆菌素对苏云金芽胞杆菌以色列亚种(Bacillus thuringiensis israelensis,Bti)LLP29胞晶混合液杀埃及伊蚊(Aedes aegypti)活性具有显著增效作用(共毒系数为128.06)。本研究为开发Bt增效剂及构建新型工程菌提供了理论基础。
Many strains of Serratia sp. Are opportunistic pathogens of some insects and have certain insecticidal activity. In this study, a strain of BRC-CXG2 (KT366770) was isolated from the septicemia of septicemia Monochamus alternatus Hope. The strain was identified by morphological characterization, 16S rDNA phylogenetic analysis, physiological and biochemical reactions, Drug sensitivity analysis and bioassay. The results showed that the isolated strain BRC-CXG2 belongs to a new species of Serratia and has different degrees of susceptibility to common drugs such as cefoperazone, cefotaxime and ceftazidime. Among them, Bacillus thuringiensis israelensis (Bti) LLP29 cell-crystal mixture has significant synergism against the activity of Aedes aegypti (co-toxicity coefficient is 128.06). This study provides a theoretical basis for the development of Bt synergist and construction of new engineering bacteria.