小湾库区微生物群落结构多样性与水质状况分析

为了解小湾库区水域微生物多样性,通过16S rDNA基因扩增和高通量测序分析了小湾库区6个采样点水域微生物群落结构组成及多样性差异。结果显示,小湾库区水体整体呈偏碱性,且含氧量丰富,COD含量为14.79~24.47 mg/L,TN浓度为0.53~2.39 mg/L,TP浓度为0.14~1.17 mg/L。不同采样点微生物Chao1指数、覆盖率均较高,Shannon指数为3.42~4.48,Simpson指数为0.029 8~0.091 9,反映出各采样点微生物群落多样性丰富,其中群落丰富度以W06区域最高。各采样点的菌门主要有变形菌门(Proteobacteria)、蓝细菌门(Cyanobacteria)、放线菌门(Actinobacteria)、拟杆菌门(Bacteroidetes)和绿弯菌门(Chloroflexi),丰度之和可达90%以上,且以变形菌门为优势菌门；在属水平上以不动杆菌属(Acinetobacter)为第一优势菌属。POCA分析表明,W05、W06区域聚为一类,而W01、W02、W03、W04区域聚为一类,具有显著差异。结果表明,小湾库区水域整体水质状况良好,但部分区域已出现水体富营养化现象且有扩散趋势,需采取环境治理措施。从渔业可持续发展来看,应通过合理放养、合理捕捞的方式,充分利用水域中天然饵料资源,在保证小湾库区水力发电的正常运行的前提下,适当开发小湾库区渔业潜力。

Microbial Community Diversity and Analysis of Water Quality Status in Xiaowan Reservoir

In order to study the microbial diversity of Xiaowan Reservoir, 16S rDNA gene amplification and high-throughput sequencing were used to analyze the composition and diversity of microbial community in 6 sample sites. The results showed that, the water in Xiaowan reservoir was alkaline and and rich in oxygen, with COD content of 14.79~24.47 mg/L, TN concentration of 0.53~2.39 mg/L, and TP concentration of 0.14~1.17 mg/L. The Chao1 index and coverage rate of different sample sites were high. The Shannon index was 3.42~4.48, Simpson index was 0.029 8~0.091 9, which reflected that the diversity of microbial community was rich, and the community richness was the highest in W09 area. The total abundance of Proteobacteria, Cyanobacteria, Actinobacteria, Bacteroidetes and Chloroflexi was more than 90%, and Proteobacteria was the dominant one. Acinetobacter was the first dominant genus at genus level. Poca analysis showed that W15 and W18 were clustered into one group, while W09, W10, W11 and W12 were clustered into another group, with significant difference. The results show that the overall water quality of Xiaowan reservoir was good, but eutrophication has already happened in some areas and there was a trend of diffusion. Therefore, prevention and control measures should be taken immediately and environmental monitoring should be carried out in Xiaowan Reservoir.