精养草鱼池塘底泥微生物群落结构分析

Microbial Community Structure in Sediments in an Intensive Grass Carp Ctenopharyngodon idellus Culture Pond

2018年4—11月,在南昌市南昌县蒋巷镇相同养殖模式的3口草鱼精养池塘中每月用彼得森采泥器采集表层底泥样品(约200 g),用MiSeq测序技术测定、分析底泥微生物群落结构。从样品中得到有效序列为47743~65233条,可归为14027~21098个运算分类单元。分析结果表明,样品中的微生物可归为54~60个门,各月主要优势门均为变形菌门,其他优势门类各月不同;各月微生物群落结构差异不显著,但10月样品主要种与其他月存在差异;5月和11月物种数丰富度达高峰,5月多样性达高峰;各月核心种主要是厌氧菌地杆菌和厌氧粘细菌,兼性厌氧菌Desulfatiglans、Candidatus competibacter、脱氯单胞菌和Crenothrix等主要在无氧或低溶解氧条件下还原有机物和硫化物的菌种;除10月外,各月核心种种类差别不大,但各月核心种丰度不同。综上,草鱼池塘底泥微生物群落结构相对稳定,存在缓慢的演替;改善底部溶解氧状态是修护草鱼养殖池塘环境最主要的措施。

The microflora community structure of sediment was monthly determined and analyzed in the samples of surface sediment(about 200 g)collected in three intensive grass carp(Ctenopharyngodon idellus)culture ponds in Jiangxiang Town,Nanchang County,Jiangxi Province from April to November 2018 by Peterson mud collector by the Illumina MiSeq sequencing technique.It was found that the microflora in all samples were classified into 54—60 phyla,among which Proteobacteria was the maximal dominant phyla,and the other dominant phyla were varied with months.There was no significant difference in the structure of microbial community in each month,while the main species were different in October from other months,with the peak of species abundance in May and November,and the maximal diversity in May.The core species included the anaerobic bacteria Geobacter and Anaeromyxobacter,and the facultative anaerobes Desulfatlans,Candidatus Competibacter,Dechloromonas and Crenothrix.These species bacteria reduced organic matter and sulfide under anaerobic or low dissolved oxygen conditions.Except in October,no significant difference in core species was observed in all months.However,the abundance of species is varied with month.In conclusion,the microflora structure in intensive grass carp culture pond sediments was relatively stable,with slow successive evolution,and increase in bottom dissolved oxygen level is the most important measure to repair the pond environment.