Abundance of anammox bacteria in different wetland soils

The diversity and activity of anammox bacteria has been studied in various environments, but knowledge about their abundance and population dynamics is scarce and particularly lacking for soils. A SYBR Green qPCR protocol was developed for the quantification of anammox bacterial 16S rRNA gene copies using newly designed primers. This primer set allows specific detection of all currently known anammox candidate genera including members of a new anammox cluster. Seven wetland soils were investigated and anammox bacterial 16S rRNA gene copy numbers of 4.01 x 104 to 6.74 x 106 per gram of fresh soil were detected. Anammox bacteria were also quantified along a Gleysol profile at three different sampling dates. Anammox 16S rRNA gene abundance increased significantly with soil depth and varied only little between seasons, suggesting that anammox bacteria represent a minor but stable microbial population in this soil.