Anaerobic ammonium-oxidizing bacteria in river water treatment wetland.

Anaerobic ammonium-oxidizing (anammox) bacteria play an essential part in nitrogen removal in constructed wetlands. The objective of the present study was to explore the spatiotemporal dynamics of anammox bacterial communities and the associated factors in a full-scale constructed wetland for the treatment of polluted surface water. The abundance and diversity of anammox bacterial communities were characterized using quantitative polymerase chain reaction (PCR) and clone library analysis, respectively. Anammox bacterial diversity, richness, and abundance in the treatment wetland differed considerably among sampling sites and seasons, whereas anammox bacterial community structure tended to change slightly with site and time. Anammox abundance was likely influenced by temperature and the contents of nitrate and nitrite nitrogen. The increase of carbon and nitrogen contents could lower wetland anammox bacterial diversity and richness. Moreover, anammox bacterial diversity, richness, and abundance were also affected by wetland vegetation type. Candidatus Brocadia dominated in the treatment wetland, whereas Candidatus Kuenenia and a novel anammox phylotype were also detected. This work could provide some new insights towards anaerobic ammonium oxidization in surface water treatment wetland.