主养草鱼池塘底泥微生物群落多样性研究

摘要

To investigate the microbial diversity in fish pond sediment, the total DNA of the sediment was extracted from a pond mainly farmed with grass carp ( Ctenopharyngodon idellus) in Shishou, Hubei province, China. The 16S rDNA was amplified using bacteria universal primers 27F and 1492R to construct a clone library. According to the 16S rDNA library, the bacterial community structure in the pond sediment was determined. It showed that the bacteria were high in species di versity. The shannon diversity index, chaol richness index, and the evenness index were 3.85, 185, and 0.96, re spectively. The community was comprised of bacterial members from the phyla of Proteobacteria (53. 66% ) , Firmicutes (14.63%), Acidobacteria (7.32%), Bacteroidetes (7.32%), Chloroflexi (3.66%), Actinobacteria (3.66%), Planctomycetes (2.44% ) and unclassified bacteria (7. 32% ). The members of Proteobacteria, especially γ-Proteobacte-ria(21.95%), predominated the community. In addition, the presence of organophosphorus-degrading bacterium, En terobacter cloacae, and pathogenic bacterium of fish disease, Acinetobacter Iwoffii, suggested that the sediment was not on ly a bacterial source for ecological restoration, but also a reservoir for pathogens of infectious diseases.%为研究主养草鱼池塘底泥微生物多样性,采用细菌通用引物27F和1492R扩增了湖北石首一草鱼(Ctenopharyngodon idellus)养殖池塘底泥细菌16S rDNA片段,构建了底泥细菌16S rDNA克隆文库,并对该文库中的微生物群落进行了分析.结果显示,该文库的Shannon多样性指数(H′)为3.85,Schao1丰富度指数为185,Evenness 均匀度指数(E)为0.96.池塘底泥中主要的细菌类群为:变形菌门(Proteobacteria) (53.66％)、厚壁菌门(Firmicutes)( 14.63％)、酸杆菌门(Acidobacteria) (7.32％)、拟杆菌门(Bacteroidetes) (7.32％)、绿弯菌门(Cbloroflexi)(3.66％)、放线菌门(Actinobacteria) (3.66％)、浮霉菌门(Planctomycetes)(2.44％)和分类地位未知(Unclassified bacteria) (7.32％)的种类.其中,变形菌门中的γ-变形菌纲(γ-Proteobacteria)是明显的优势类群(21.95％).草鱼养殖池塘底泥中微生物种类丰富,而磷代谢功能菌Enterobacter cloacae和鱼类病原菌Acinetobacter lwoffii的出现表明池塘底泥既是生态修复功能菌的资源库,也是鱼类细菌性疾病的病原库.