Bacterial community in midguts of the silkworm larvae estimated by PCR/DGGE and 16S rDNA gene library analysis
Bacterial community in midguts of the silkworm larvae estimated by PCR/DGGE and 16S rDNA gene library analysis
复制标题
DOI：
--
复制
发表时间：
2007
期刊：
影响因子：
--
通讯作者：
X. Hui
中科院分区：
文献类型：
--
作者：
X. Hui
本文对家蚕单食性品系C108和多食性品系SCN 2幼虫中肠的细菌群落进行了调查，利用16 S PCR-DGGE技术和克隆文库，对一种经济上重要的昆虫-黑腹小蜂进行了研究。文库序列分析表明，PCR 扩增得到的16S rDNA基因代表了家蚕中肠内的41种细菌系统发育型（phylotype），大多数属于Proteobacteria，其次是Lactobacillales。在中肠细菌群落中，以变形菌门和乳酸菌门为主，其次为奇球菌-栖热菌门、芽孢杆菌门、梭菌门和放线菌门。在两种供试菌株中，以肠球菌属的种系型最多，其次是栖热菌属。两株肠球菌的细菌组成或种群结构存在差异，同一株肠球菌在不同饲料下的细菌组成或种群结构也存在差异。特别是在SCN 2菌株饲喂不含桑葚的人工饲料时，中肠葡萄球菌（Staphylococcus）的系统发育型出现的比例较高。DGGE图谱显示，不同年龄幼虫的细菌谱型存在差异。这可能与两个发育阶段的生理差异有关。结果表明，家蚕特殊食性可能与特殊细菌的出现有关，不适宜的饲料可能破坏家蚕中肠菌群的平衡，阻碍家蚕的正常生长。
We inventoried the bacteria community and the effects of diet on bacterial composition in larval midguts of two strains (the monophagous C108 and the polyphagous SCN2) of the silkworm, Bombyx mori L., an economically important insect, using 16S PCR-DGGE and clone libraries. DNA sequence analysis indicated that the PCR-amplified 16S rDNA genes represented 41 phylotypes of bacteria. Most of them belonged to the Proteobacteria and Lactobacillales, whereas less dominant taxa including members of the Deinococcus-Thermus, Bacillales, Clostridiales and Actinobacteria were also found in the midgut bacterial community. Phylotypes of Enterococcus were the most dominant group in both strains tested, followed by Thermus. Bacterial composition or population structure of Enterococcus varied between the two strains and in the same strain fed with different diets. Especially, when strain SCN2 was fed with mulberry-free artificial diet, a midgut phylotype belonging to Staphylococcus appeared with a fairly high proportion. DGGE profiles demonstrated that there were differences in the bacterial pattern between young and old larvae. This might be related with the differences of physiology between the two developmental stages. The results suggested that the appearance of special bacteria might associate with the special phagy of the silkworm, and unfit diet might destroy the balance of midgut microbiota to block normal growth of the silkworm.