大口黑鲈生态塘微生态及水理化指标变化分析

Dynamic Changes in Physical-Chemical Factors and Microbial Diversity in Ecological Culture Ponds of Largemouth Bass Micropterus salmoides

为探究7—9月大口黑鲈生态养殖池塘微生物与水质理化指标的变化及关系,采用高通量测序法测定天津某大口黑鲈生态养殖池塘7—9月的微生物群落结构,并对养殖区和微生态区表层水理化指标进行监测。试验结果显示,该池塘微生物多样性在7—9月发生变化,底泥微生物α多样性始终高于水样和毛刷。各样本中优势菌均包含变形菌门;水体中蓝细菌门在9月发展为优势物种;毛刷样本各月份优势菌不同,9月时厚壁菌门比例最高。水体理化指标在7—9月发生变化,养殖和微生态区水体氨氮含量均在8月达到最高值,9月时两区域的总氮、正磷酸盐、高锰酸盐指数、固体悬浮物质量浓度、pH和总碱度最高。相关性分析表明:微生态区水体中硝态氮含量与毛刷中根瘤菌科丰度显著负相关;养殖区和生态区水中亚硝态氮含量分别与底泥中红杆菌科和毛刷中Norank_o__norank_c__Nitrospira丰度显著负相关(P<0.05)。研究结果可为大口黑鲈7—9月生态池塘水质及微生物的调控和二者相关的后续研究及修复水质功能菌的筛选提供参考。

To explore the changes of microorganisms and water quality physicochemical indices in ecoculture ponds of largemouth bass Micropterus salmoides in July-September and their relationship,the microbial community structure was determine by high throughput sequencing technology and the physico-chemical indices were monitored in surface water in the cultured areas and microecosystem of a largemouth bass ecological culture pond in Tianjin from July to September.After the aquaculture tail water was treated by aquatic vegetables,the surface water entered the micro-ecological filtration area with brush as the matrix,and then the bottom water entered the aquatic vegetable treatment area and finally entered the 300 m 2 culture pond with 4000 individuals of largemouth bass for recycling.The results showed that there was always higherαdiversity of microbial diversity in the sediment than that in water and brush,with the dominant microorganisms in Proteobacteria in all samples.Cyanobacteria in the water was found to be gradually increased to the dominant species in September,with change in the dominant bacteria in the brush samples with the time of cultivation and with the maximal proportion of Firmicutes in September.The maximal content of ammonia nitrogen was observed in the water in the aquaculture area and the microecological area in August,with the maximal contents of total nitrogen,orthophosphates,permanganate index,and suspended solids(SS),and pH and total alkalinity in September in the two regions.The correlation analysis showed that there was a significant negative correlation between the nitrate nitrogen content in the water and the Rhizobiales Incertae Sedis abundance in the brush.There was significant negative correlation between the content of nitrite nitrogen and the abundance of Rhodobacteraceae in sediment and Norank_o__norank_c__Nitrospira in brush(P<0.05).The findings provide a reference for the regulation of water quality and microorganisms in ecological ponds and the subsequent related studies,and the screening of functional bacteria for remediation of water quality in largemouth bass from July to September.