Molecular and stable isotopic evidence for anaerobic ammonium-oxidizing bacteria in tidal flow constructed wetlands

• Published in: International biodeterioration & biodegradation Vol. 149; p. 104915
• Main Authors: Zhang, Manping, Huang, Jung-Chen, Sun, Shanshan, Rehman, Muhammad Muneeb Ur, He, Shengbing
• Format: Journal Article
• Language: English
• Published: Barking Elsevier Ltd 01.04.2020; Elsevier BV
• Subjects: Abundance; Ammonia-oxidizing bacteria; Ammonium; Anaerobic processes; Anammox bacteria; Artificial wetlands; Bacteria; Biodiversity; Community composition and abundance; Cores; Estuaries; Gas production; Nitrogen; Nitrogen cycle; Nitrogen gas production; Nitrogen isotopes; Oil and gas production; Oxidation; Potential anammox activities; rRNA 16S; Soil water; Soils; Tidal flow; Tidal flow constructed wetlands; Vertical distribution; Water depth; Wetlands; Tidal flow constructed wetlands; Potential anammox activities; Community composition and abundance; Nitrogen gas production; Anammox bacteria
• ISSN: 0964-8305; 1879-0208
• DOI: 10.1016/j.ibiod.2020.104915

The process of anaerobic ammonium oxidation (anammox) plays a significant part in global nitrogen cycling, yet its depth-specific distribution and importance in tidal flow constructed wetlands (TF CWs) remained unclear. Currently, the abundance, biodiversity, vertical distribution, rates and potential role of the anammox process in two TF CWs of the Yangtze Estuary, China, were explored. The results indicated that anammox bacteria were widely distributed in the TF CWs, and Candidatus Brocadia was the dominant group among the anammox genera. The widespread presence of the anammox bacteria was observed at different water depths of the soil cores, and the abundance of total bacterial 16S rRNA and hzsB genes was 4.47–20.08 × 109 and 0.81–5.91 × 105 copies per gram of dry soil (copies g−1 ds), respectively. The homogenized soils were incubated with stable nitrogen isotope to confirm the rates of anammox in the TF CWs, and the anammox activities were 2.38–6.72 nmol of N2 per gram of dry soil per day (nmol N2 g−1 dry soil d−1), with contributions of 2.7–7.5% nitrogen gas production and anammox that was more active in the deeper layer of the two TF CWs. •Anammox bacteria were widespread across soil profiles in TF CWs.•Candidatus Brocadia was dominant anammox bacterial genus.•Potential anammox rates were higher deep in soil profiles; its contribution to N2 production was 2.7–7.5%.•Nitrite concentrations limited anammox bacterial activity.