网箱养殖对升钟湖沉积物细菌群落多样性的影响

Impact of Fish Cage Culture on the Composition and Diversity of Microbial Communities in Sediments of the Shengzhong Lake

微生物在湖泊生态系统的物质循环和能量流动中发挥着重要作用,为了探究网箱养殖对湖泊沉积物细菌群落组成、多样性以及环境因子的影响,研究了在升钟湖采集网箱养鱼区和对照区的沉积物,进行MiSeq测序和化学分析等。结果表明:①网箱养殖导致沉积物的pH值显著降低(P<0.05),NH^(+)_(4)-N、NO^(-)_(3)-N和总氮含量显著升高(P<0.05);②网箱养殖区的细菌ACE指数、Chao1指数、Shannon指数显著高于对照区(P<0.05);③LEfSe多级物种差异判别分析显示网箱养殖区沉积物微生物群落结构发生了显著改变(P<0.05),在门水平上,厚壁菌门(Firmicutes)、放线菌门(Actinobacteria)、蓝藻细菌门(Cyanobacteria)、浮霉菌门(Planctomycete)等门的相对丰度显著增加;在目和属水平上,小梨形菌(Pirellulales)、梭状芽孢杆菌(Clostridiales)、互营杆菌(Syntrophorhabduss)等的相对丰度显著增加(P<0.05);④冗余分析表明,pH、TN、NH^(+)_(4)-N等环境因素对网箱养殖区底泥细菌群落分布影响均不显著(P>0.05)。网箱养鱼显著影响了湖泊沉积物的细菌的群落组成,但所测定的环境因素对微生物菌群结构的影响均不显著,研究结果为探讨网箱养殖对人工湖生态系统结构和功能的影响提供了一定的基础数据。

Microorganisms play an important role in the biological material circulation and energy flow of lake ecosystems.To explore the impact of fish cage culture on the bacterial community structure and diversity of lake sediments,sediment samples were collected from the cage culture area and the control area of the Shengzhong Lake,which is the largest artificial reservoir in the southwest China.The 16S rRNA-based MiSeq high-throughput sequencing technology and chemical analysis method were employed.The results showed that:①The pH values of the sediment samples decreased for the cage culture,whereas the contents of NH^(+)_(4)-N,NO^(-)_(3)-N,and total nitrogen(TN)of the sediment samples increased significantly in the cage culture area.②The ACE index,Chao1 index and Shannon index of the microbial communities in the cage culture area were all higher than those in the control area(P<0.05).③The LEfSe multi-level discriminant analysis of species differences showed that the compositions of microbial communities of the sediment samples were significantly altered by the cage culture in the area(P<0.05).At the phylum level,Firmicutes,Actinobacteria,Cyanobacteria,and Planctomycete were remarkedly enriched in the sediment samples from the cage culture area.At the genus level,the relative abundance of Pirellulales,Clostridiales,Syntrophorhabduss were significantly enriched.④Redundancy analysis showed that the parameters,such as pH,NO^(-)_(3)-N,TN,and NH^(+)_(4)-N,contributed to the variation of the microbial communities,but these factors were all not the significant drivers.These results indicate that the ecology of the sedimental microbial communities is significantly impacted by the fish cage culture.This study provides important reference for the assessment of impacts of the fish cage culture on the functions of lake ecosystem.