日照贝类养殖区海水微生物群落结构特征及其影响因素

Characteristics and Impact Factors of Seawater Microbial Community Structure in Rizhao Shellfish Aquaculture Area

微生物群落结构和组成差异是反映海洋生态系统环境健康的有效指标,对生态环境监测和管理具有重要意义,同时可以为水产养殖活动提供启示。本文针对日照某贝类养殖区及非养殖区水体环境的微生物群落结构进行了测序和分析,并探讨了环境因子对微生物群落结构和多样性的影响。结果显示,变形菌门(Proteobacteria)是养殖区海水的优势细菌类群,其次是蓝细菌门(Cyanobacteria)和放线菌门(Actinobacteria)。养殖区表层海水中蓝细菌门的相对丰度(P=0.003)以及8 m深度水层中变形菌门的相对丰度(P=0.027)显著高于非养殖区。微生物多样性分析表明,4月至11月养殖区表层及8 m水层的微生物Shannon指数范围分别为5.59~6.92和5.33~7.08,与非养殖区无明显差异,但养殖区的微生物丰富度指数(表层Chao1=1 088.86,8 m深度水层Chao1=1 158.77)略低于非养殖区(表层Chao1=1 108.63,8 m深度水层Chao1=1 210.30)。典型相关性分析(CCA)和Spearman相关性分析结果表明,温度(P=0.003)、盐度(P=0.001)、悬浮物(P=0.001)和溶解氧(P=0.001)是影响养殖区微生物群落结构的主要环境因素。弧菌属细菌数量在5月养殖区8 m深度水层发生了爆发式增长,平均相对丰度达到51.21%,显著高于养殖区表层和非养殖区表层及8 m水层。本文结果可为贝类健康养殖及养殖海域生态系统保护提供参考。

Microbial community structure and composition difference are an effective indicator of the environmental health of marine ecosystems,which are crucial for ecological monitoring and management,as well as providing insight into aquaculture activities.In this paper,the gene sequencing and analysis were conducted to reveal the seawater microbial community structure of shellfish aquaculture and non-aquaculture area in Rizhao,and the effects of environmental factors on the microbial community structure and diversity were explored.Results showed that the most abundant microbial taxa in seawater from the aquaculture area were Proteobacteria,followed by Cyanobacteria and Actinobacteria.The relative abundance of Cyanobacteria(P=0.003)in the surface layer and Actinobacteria(P=0.027)in the 8-meter water layer were significantly higher in the aquaculture area than in nonaquaculture area.Microbial diversity analysis showed that from April to November,the Shannon values in the surface layer and the 8-meter water layer of aquaculture area were ranged from 5.59−6.92 and 5.33−7.08 respectively,which were not significantly different compared from those in the non-aquaculture area,but the microbial abundance in aquaculture area(Chao1=1088.86 in the surface layer,Chao1=1158.77 in the 8-meter water layer)was slightly lower than that in the non-aquaculture area(Chao1=1108.63 in the surface layer,Chao1=1210.30 in the 8-meter water layer).According to canonical correspondence analysis(CCA)and Spearman's correlation analysis,the temperature(P=0.003),salinity(P=0.001),suspended solids(P=0.001)and dissolved oxygen(P=0.001)were the main environmental factors affecting the microbial community structure in aquaculture area.In May,pathogenic bacteria of the genus Vibrio increased dramatically in 8-meter water layer of aquaculture area,with an average relative abundance of 51.21%,significantly higher than that of othe layers of aquaculture and non-culture area.This research will provide a reference for maintaining a healthy shellfish culture and protecting the ecosystem of aquaculture area.