The distribution of dissimilatory nitrate reduction to ammonium bacteria in multistage constructed wetland of Jining, Shandong, China

Dissimilatory nitrate reduction to ammonium (DNRA) is an important process of nitrate reduction in the environment. The distribution of DNRA bacteria and the relationships with environmental factors in multistage constructed wetland were investigated in this study. The quantitative real-time polymerase chain reaction analysis showed that the abundance of DNRA bacteria at all sites ranged from 2.10 × 1010 to 1.10 × 1011 copies/g of dry sediments. The Anaeromyxobacter (belong to Deltaproteobacteria) was the most abundant DNRA bacteria at all sites. The Geobater known as DNRA bacteria was also identified in this study. The abundances of DNRA bacteria, denitrifying bacteria, and anammox bacteria were conspicuously negatively correlated with Eh and positively correlated with the NO3--N removal efficency by statistical analysis.