海水池塘跑道养殖系统中鱼类肠道及养殖环境的细菌群落研究

Studies on Bacterial Community in Fish Gut and Environment of a Marine in-Pond Raceway Pond System

为查明海水池塘跑道养殖系统(IPRS)的不同生境中细菌群落特征以及不同群落间的相互作用关系,本研究采用16S rRNA基因高通量测序技术对IPRS中鱼类肠道、水体和沉积物的细菌群落组成和结构进行了研究。研究表明,鱼类肠道、水体和沉积物的细菌群落在结构和多样性上均存在显著差异。不同生境中细菌群落的优势组成不同,花鲈(Lateolabrax maculatus)肠道内相对丰度最高的菌门为厚壁菌门(Firmicutes, 57.92%),河鲀(Takifugu rubripes)肠道内为弯曲杆菌门(Campylobacterota, 41.17%),水体和沉积物中均为变形菌门(Proteobacteria),其相对丰度分别达到91.03%和48.06%。LEfSe分析表明,栖粪杆菌属(Faecalibacterium)、拟杆菌属(Bacteroides)和罗氏菌属(Roseburia)等20个菌属在花鲈肠道内显著富集;unclassified_Arcobacteraceae、普雷沃菌属(Prevotellaa)和罗尔斯顿菌属(Ralstonia)等12个菌属在河鲀肠道内显著富集;伍斯菌属(Woeseia)、Muribaculaceae和unclassified_Halieaceae等26个菌属在沉积物中显著富集;Clade_Ⅰa、Clade_Ⅲ和HIMB11等10个菌属在水体中显著富集。IPRS不同功能区的沉积物菌群结构也存在显著差异。其中,固体废物收集区与净水区的差别较大,Sva1033、uncultured_Desulfocapsaceae、unclassified_Flavobacteriaceae和unclassified_Rhodobacteraceae等一些能够降解有机物和去除氮、磷、硫等营养盐的细菌在固体废物收集区沉积物中大量富集,这一群落特征与其功能相匹配。鱼类肠道菌群与水体菌群相似度较小,而与沉积物菌群相似度较大。河鲀和花鲈肠道菌群与沉积物菌群的平均相似度分别为4.00%和2.85%,这表明河鲀肠道菌群受沉积物的影响更大。

In order to identify and characterize the bacterial communities in different habitats of IPRS and the interactions between different communities,the bacterial community composition and structure of the fish gut,water and sediment of a marine in-pond raceway system(IPRS)were investigated using 16S rRNA gene high-throughput sequencing technology in this study.Results showed that the bacterial communities in fish gut,water and sediment were significantly different in diversity and structure.The dominant taxa of bacterial communities in different habitats were different.Firmicutes(57.92%)was the most abundant phylum in the gut of spotted seabass(Lateolabrax maculatus),Campylobacterota(41.17%)in the gut of tiger puffer(Takifugu rubripes),and Proteobacteria in the water(91.03%)and sediment(48.06%).LEfSe analysis showed that 20 genera(Faecalibacterium,Bacteroides,Roseburia,among others)were significantly enriched in the gut of spotted seabass;12 genera(unclassified_Arcobacteraceae,Prevotella,Ralstonia among others)were significantly enriched in the gut of tiger puffer;26 genera(Woeseia,Muribaculaceae,unclassified_Halieaceae,among others)were significantly enriched in the sediment;10 genera(Clade_Ⅰa,Clade_Ⅲ,HIMB11,among others)were significantly enriched in the water.There were also significant differences in the structure of sediment bacterial communities from different functional areas of IPRS.Furthermore,the solid waste collection area was more different from the purification area,and some bacteria capable of degrading organic matter and removing excess nutrients(nitrogen,phosphorus and sulfur),such as Sva1033,uncultured_Desulfocapsaceae,unclassified_Flavobacteriaceae and unclassified_Rhodobacteraceae,were abundantly enriched in the sediment of the solid waste collection area.This community characteristic matched with their functions.The gut bacterial communities of cultured fish were less similar to the water bacterial communities while there was a closer relationship with the sediment bacterial communities.The average similarity between the gut and sediment bacterial communities for tiger puffer and spotted seabass was 4.00%and 2.85%,respectively,indicating that the gut bacterial communities of tiger puffer was relatively more influenced by sediment.