橘小实蝇成虫肠道可培养细菌群落结构分析

【目的】研究橘小实蝇(Bactrocera dorsalis) 3个种群(实验室正常喂养种群、实验室无菌糖水喂养种群和野生种群)成虫肠道可培养细菌的群落结构组成。【方法】利用16S rRNA基因的聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)分析技术，结合菌落形态观察和生理生化特征鉴定细菌种类。【结果】从橘小实蝇3个种群成虫肠道600株可培养细菌得到53种不同细菌遗传型，分属于肠杆菌科(Enterobacteriaceae)、肠球菌科(Enterococcaceae)和芽孢杆菌科(Bacillaceae)等3个科。其中肠杆菌科是肠道可培养细菌最优势的细菌种类。同样以序列相似性大于97%的菌株归为相同的细菌种类为标准，找到了橘小实蝇3个种群可培养细菌的共有菌种，结合菌落形态观察和生理生化特征鉴定，确定共有菌种为肠杆菌属5株，克雷伯氏菌属2株，柠檬酸杆菌属1株，泛菌属1株，肠球菌属2株，以及芽孢杆菌属4株。【结论】通过研究橘小实蝇成虫肠道可培养细菌群落结构组成，可为探讨肠道菌群对寄主的生理功能和生态学意义奠定基础，最终为利用微生物防治此类害虫提供新思路。

The community structure of the intestine cultivable bacteria of Bactrocera dorsalis adults

Objective] In order to identify the community structure of the cultivable bacteria inhabiting the intestinal tract of adult oriental fruit flies (Bactrocera dorsalis) from laboratory-reared, laboratory sterile sugar-reared, and field-collected populations. Methods] 16S rRNA gene PCR-DGGE molecular methods was employed to study the bacterial diversity. At the same time, the common species of cultivable bacteria were identified by colony morphology, physiological and biochemical characteristics tests. Results] Six hundred culturable bacteria in the intestinal tract of adult B. dorsalis from the aboved three populations were classified into 53 unique phylotypes. All sequenced bacteria strains were grouped into three families: Enterobacteriaceae, Enterococcaceae and Bacillaceae. The Enterobacteriaceae was dominated in all the populations. The closely related sequences (>97% sequence similarity) which had been retrieved from culturable bacteria of three populations were grouped as one common species. We determined the common species: five strains of bacteria as Enterobacter, two strains of Klebsiella, one strain of Citrobacter, one strain of Pantoea, two strains of Enterococcus, and four strains of Bacillus. Conclusion] The present study significantly contributes to the available information on bacterial isolates and the biological control of B. dorsalis.