中华绒螯蟹养殖池塘菌群结构和功能特征

Structural and functional characteristics of microbial communities in aquaculture ponds of Chinese mitten crab Eriocheir sisensis L

通过Hiseq高通量测序方法分析了中华绒螯蟹(Eriocheir sisensis L.)养殖池塘和外源河水体的微生物群落结构、功能特征以及与环境因子的关系。结果表明:养殖池水体的6个样本,共得到有效序列541349条,可归纳为2938个OTU;外源河水体的6个样本,共得到有效序列551891条,可归纳为2779个OTU;池塘沉积物的6个样本,共得到有效序列557736条,可归纳为8920个OTU。α-多样性分析表明,养殖池沉积物的Sobs指数、Shannon指数、Simpson指数、Chao指数均显著高于水体样本;β-多样性分析表明,各样本菌群按照菌群结构可以分为两大类,既沉积物组和水体组;在养殖池和外源河水体中,门水平的优势菌群主要有变形菌门(Proteobacteria)、放线菌门(Actinobacteria)、蓝细菌门(Cyanobacteria)、疣微菌门(Verrucomicrobia)、浮霉菌门(Planctomycetes)、拟杆菌门(Bacteroidetes);在养殖池沉积物中,门水平的优势菌群主要有变形菌门(Proteobacteria)、浮霉菌门(Planctomycetes)、酸杆菌门(Acidobacteria)、疣微菌门(Verrucomicrobia)、绿弯菌门(Chloroflexi)、拟杆菌门(Bacteroidetes)。冗余分析表明,温度(r2=0.915,P<0.01)、p H (r2=0.8,P<0.01)、溶氧量(r2=0.65,P<0.01)、水质总硬度(r2=0.756,P<0.01)与菌群结构呈极显著相关,NH3-N、NO2--N、COD、NO3--N、TP、TN与菌群结构无显著相关性。方差分解分析表明,在门水平对水体菌群分布贡献度较大的环境因子为pH、温度和溶氧量,贡献度分别为44.14%、41.20%和33.2%。Tax4Fun对各样本的菌群进行基因功能预测表明,在level 2水平下共得到37个预测功能,水体和沉积物中主要优势功能均为碳水化合物代谢、氨基酸代谢。沉积物菌群中氨基酸代谢、脂类代谢、膜转运、外源性生物降解和代谢的功能基因丰度显著低于养殖水体,能量代谢、多糖生物合成和代谢的功能基因丰度显著高于养殖水体。研究结果为河蟹养殖环境调控和生态环境保护提供了科学基础。

We analyzed the structure and function of microbial community and their relationships with environmental factors in aquaculture ponds of mitten crab and water of exogenous river,based on Illumina Hi Seq high-throughput sequencing technique. A total of 541349 effective tags were obtained in six water samples of ponds,which were clustered into 2938 OTUs( operational taxonomic units). A total of 551891 effective tags were obtained in six water samples of exogenous river,which were clustered into 2779 OTUs. A total of 557736 effective tags were obtained in six sediment samples of ponds,which were clustered into 8920 OTU. The α-diversity( Sobs index,Shannon index,Simpson index,and Chao index) of the sediment samples was significantly higher than that of the water samples. The results of β-diversity analysis showed that the samples could be divided into two groups according to the microbial community structure,i.e.,sediment group and water group. Proteobacteria,Actinobacteria,Cyanobacteria,Verrucomicrobia,Planctomycetes,and Bacteroidetes were the dominant phyla in waters of aquaculture ponds and exogenous river. Proteobacteria,Planctomycetes,Acidobacteria,Verrucomicrobia,Chloroflexi,and Bacteroidetes were the dominant phyla in the sediments. The results of redundancy analysis showed that temperature( r2= 0.915,P<0.01),pH( r2= 0.8,P<0.01),dissolved oxygen( r2=0.65,P<0.01),and total hardness of water( r2= 0.756,P<0.01) were significantly correlated with bacterial community structure,while NH3-N,NO2--N,COD,NO3--N,TP,and TN were not significantly correlated with bacterial community structure. The results of variance partitioning analysis showed that pH,temperature,and dissolved oxygen were highly contributed to the microbial community distribution at phylum level,with a contribution rate of 44.14%,41.20%,and 33.2%,respectively. A total of 37 predicted functions were obtained at level 2 by TaxFun method. Carbohydrate metabolism and amino acid metabolism were the dominant functions in both water and sediment. The abundance of functional genes involved in amino acid metabolism,lipid metabolism,membrane transport,xenobiotic biodegradation and metabolism in the sediments was significantly lower than that in the water,while the abundance of functional genes involved in energy metabolism,glycan biosynthesis and metabolism in the sediments were significantly higher than that in the water. Our results provide a scientific basis for the environmental regulation and ecosystem maintenance of mitten crab culture.