Identification of Core Microorganism in Anammox Consortia Obtained from Different Incubation Environments

Anammox is a novel and sustainable wastewater treatment technology which attracts much attention. The impossible isolation of pure anammox bacteria makes the issue about which bacteria types mainly involved in the anammox consortia meaningful but still lacks of investigation nowadays. In order to elucidate the core constituent of anammox consortia, we investigated microbial communities of six anammox consortia with different origins and activities by cloning 16S rRNA gene region. It is found that the stable anammox consortia have similar community structure, even with different origins (e.g. activated sludge and ground water). The bacteria species belonging to Chlorobi, Chloroflexi, Bacteroidetes, Proteobacterium, Nitrosomonas and Armatimonadetes are the common accompanying bacteria with Plantomycetes in anammox consortia, serving as core microorganisms. The further nitrogen removal profile analysis suggested that, high nitrogen removal activity corresponded to high Plantomycetes percentage. On the contrary, the bacteria species of Rhodocyclaceae, Acidobacteria and Verrucomicrobia mainly present in anammox consortia with abnormal nitrogen removal performance, such as under conditions of bacteria being inhibited. These findings would advance the understanding of anammox microbial community, which correlates with the stability and robustness of anammox consortia.