Deng Ya-Le, Ruan Yun-Jie, Zhu Song-Ming, Guo Xi-Shan, Han Zhi-Ying, Ye Zhang-Ying, Liu Gang, Shi Ming-Ming
Institute of Agricultural Bio-Environmental Engineering, College of Bio-systems Engineering and Food Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China.
Aquaculture and Fisheries Group, Department of Animal Sciences, Wageningen University, 6708 WD, Wageningen, The Netherlands.
AMB Express. 2017 Dec;7(1):113. doi: 10.1186/s13568-017-0412-3. Epub 2017 Jun 2.
The interactions between environmental factors and bacterial community shift in solid-phase denitrification are crucial for optimum operation of a reactor and to achieve maximum treatment efficiency. In this study, Illumina high-throughput sequencing was applied to reveal the effects of different operational conditions on bacterial community distribution of three continuous operated poly(butylene succinate) biological denitrification reactors used for recirculating aquaculture system (RAS) wastewater treatment. The results indicated that salinity decreased OTU numbers and diversity while dissolved oxygen (DO) had no obvious influence on OTU numbers. Significant microbial community composition differences were observed among and between three denitrification reactors under varied operation conditions. This result was also demonstrated by cluster analysis (CA) and detrended correspondence analysis (DCA). Hierarchical clustering and redundancy analysis (RDA) was performed to test the relationship between environmental factors and bacterial community compositions and result indicated that salinity, DO and hydraulic retention time (HRT) were the three key factors in microbial community formation. Besides, Simplicispira was detected under all operational conditions, which worth drawing more attention for nitrate removal. Moreover, the abundance of nosZ gene and 16S rRNA were analyzed by real-time PCR, which suggested that salinity decreased the proportion of denitrifiers among whole bacterial community while DO had little influence on marine reactors. This study provides an overview of microbial community shift dynamics in solid-phase denitrification reactors when operation parameters changed and proved the feasibility to apply interval aeration for denitrification process based on microbial level, which may shed light on improving the performance of RAS treatment units.
环境因素与固相反硝化中细菌群落变化之间的相互作用对于反应器的最佳运行和实现最大处理效率至关重要。在本研究中，采用Illumina高通量测序技术揭示不同运行条件对用于循环水养殖系统（RAS）废水处理的三个连续运行的聚丁二酸丁二醇酯生物反硝化反应器中细菌群落分布的影响。结果表明，盐度降低了OTU数量和多样性，而溶解氧（DO）对OTU数量没有明显影响。在不同运行条件下，三个反硝化反应器之间以及内部均观察到显著的微生物群落组成差异。聚类分析（CA）和去趋势对应分析（DCA）也证明了这一结果。进行层次聚类和冗余分析（RDA）以检验环境因素与细菌群落组成之间的关系，结果表明盐度、DO和水力停留时间（HRT）是微生物群落形成的三个关键因素。此外，在所有运行条件下均检测到简单螺旋菌属，其在硝酸盐去除方面值得更多关注。此外，通过实时PCR分析了nosZ基因和16S rRNA的丰度，结果表明盐度降低了整个细菌群落中反硝化菌的比例，而DO对海洋反应器影响不大。本研究概述了运行参数变化时固相反硝化反应器中微生物群落的变化动态，并从微生物水平证明了间歇曝气应用于反硝化过程的可行性，这可能为提高RAS处理单元的性能提供思路。
