Relationship between bacterial community structure and nitrification rate in freshwater aquaculture water
HE Mengying, XIONG Ying, CHENG Kai
(Hubei Key Laboratory of Ecological Restoration for River-Lakes and Algal Utilization,College of Resources and Environmental Engineering,Hubei University of Technology,Wuhan 430068,China)
Abstract:To study the relationship between bacterial community structure and nitrification rate in three types of freshwater aquaculture water(i.e. intensive shrimp & crab farming pond, aquaculture lake and intensive fish farming pond), 16S rRNA high-throughput sequencing and flow cytometer were used to analyze the bacterial community structure and total bacterial concentration, respectively, in 15 aquaculture waters. Also, the nitrification rate was measured. The results showed that the dominant phyla in freshwater aquaculture water were Proteobacteria, Actinobacteria and Bacteroidetes, and the diversity of bacterial community in summer was significantly higher than that in spring(p〈0.05). In spring, the nitrite-oxidizing bacteria (NOB) were Nitrotoga and Nitrobacter, and the abundance of Nitrobacter was significantly positively correlated with nitrification rate (p〈0.05), and the abundance of NOB in intensive fish farming pond was significantly higher than other waters (p〈0.05). In summer, Nitrospira was the dominant NOB, and its abundance was significantly positively correlated with nitrification rate (p〈0.05), and the abundance of NOB in aquaculture lake was significantly higher than other waters (p〈0.05). In addition, the abundances of Xanthomonadales in spring and summer were all positively correlated with nitrification rate. The results showed that the distribution of NOB in aquaculture water was affected by season and type of aquaculture water, and the nitrification rate was affected by the combined influence of various sorts of bacteria.