Abundance, diversity, and community composition of anammox bacteria in sediments of Xiangshan Bay, China

Xiangshan Bay (XSB) is a typical semi-closed bay rich in dissolved inorganic nitrogen and anammox is one of the important processes of nitrogen cycle. The anammox bacterial abundance and diversity in XSB sediments was investigated. Five known genera were detected based on the anammox bacterial 16S rRNA gene, namely, Ca. Scalindua, Ca. Brocadia, Ca. Kuenenia, Ca. Jettenia, and Ca. Anammoxoglobus, and hzo genes affiliating with Ca. Scalindua were also discovered. The anammox bacterial 16S rRNA and hzo genes in the sediments varied from 2.10 x 10(6) to 2.18 x 10(7) and from 2.90 x 10(6) to 5.48 x 10(8) copies/g (fresh weight), respectively. Pearson correlation analysis demonstrated that the abundance of the hzo gene was positively correlated with the concentration of NH4+ but negatively correlated with salinity and pH. Redundancy analysis showed that salinity, dissolved oxygen, and temperature were the three main factors influencing the community composition of anammox bacteria obtained by the anammox bacterial 16S rRNA gene. These findings help us to further understand the distribution and community composition of anammox bacteria in estuary sediments. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study identified a variety of anammox bacteria in Xiangshan Bay sediments, including five known genera. The abundance and diversity of anammox bacteria are influenced by factors such as salinity, dissolved oxygen, and temperature.