斜纹夜蛾幼虫肠道细菌分离鉴定及其功能初步分析

Isolation and preliminary functional analysis of the larval gut bacteria from Spodoptera litura

昆虫肠道微生物对其寄主的生长发育、营养代谢、免疫以及农药抗性等方面都发挥着重要作用。为研究斜纹夜蛾Spodoptera litura幼虫肠道细菌的多样性,并为其功能验证做准备,本文利用传统微生物分离纯培养方法从斜纹夜蛾4龄幼虫肠道中共分离鉴定得到10株细菌,分别为属于变形菌门(Proteobacteria)的脱氮假单胞菌(Pseudomonas denitrificans),不动细菌(Acinetobacter sp.),肺炎克雷伯氏菌(Klebsiella pneumoniae)和肠杆菌(Enterobacter sp.);属于厚壁菌门(Firmicutes)的鸡葡萄球菌(Staphylococcus gallinarum),蒙氏肠球菌(Enterococcus mundtii),蜡样芽胞杆菌(Bacillus cereus)和枯草芽胞杆菌(Bacillus subtilis)以及放线菌门(Actinobacteria)的微杆菌(Microbacteriums sp.)和乳酪棒杆菌(Corynebacterium casei)。变形菌门和厚壁菌门是斜纹夜蛾肠道可培养细菌中的优势菌群。功能验证实验表明肠杆菌具备纤维素降解能力,微杆菌具备很强的苯酚降解能力。本研究为未来深入研究斜纹夜蛾肠道微生物的功能提供了方向和菌株材料。

The symbionts of insect gut play important roles in the development, food digestion, immunity and even insecticide resistance of its host insect. In order to study the diversity of the gut bacteria in Spodoptera litura, and prepare bacteria clones for functional verification, ten different strains of bacteria were isolated and identified from the 4th-instar larval gut. The isolated bacteria Pseudomonas denitrificans, Acinetobacter sp. , Klebsiella pneumoniae and Enterobacter sp. were subjected to the phylum of Proteobacteria. The Staphylococcus gallinarum, Enterococcus mundtii, Bacillus cereus, and Bacillus subtilis were members of Firmicutes, the Microbacteriums sp. and Corynebac- terium casei were members of Actinobacteria. The gut bacteria of Spodoptera litura were dominated by Proteobaeteriaand Firmicutes. Preliminary functional analysis has revealed biodegradation activity on cellulose and phenol by the strains of Enterobacter sp. and Microbacterium sp., respectively. This work provides potential orientations and availa- ble strains for functional studies of the gut bacteria in Spodoptera litura.