Ecological interactions and the underlying mechanism of anammox and denitrification across the anammox enrichment with eutrophic lake sediments

Dandan Zhang; Huang Yu; Yuchun Yang; Fei Liu; Mingyue Li; Jie Huang; Yuhe Yu; Cheng Wang; Feng Jiang; Zhili He; Qingyun Yan

doi:10.1186/s40168-023-01532-y

Ecological interactions and the underlying mechanism of anammox and denitrification across the anammox enrichment with eutrophic lake sediments

Microbiome. 2023 Apr 20;11(1):82. doi: 10.1186/s40168-023-01532-y.

Authors

Dandan Zhang¹, Huang Yu¹, Yuchun Yang¹, Fei Liu¹, Mingyue Li¹, Jie Huang², Yuhe Yu², Cheng Wang¹, Feng Jiang¹, Zhili He¹, Qingyun Yan³

Affiliations

¹ Environmental Microbiomics Research Center, School of Environmental Science and Engineering, School of Ecology, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), State Key Laboratory for Biocontrol, Sun Yat-Sen University, Guangzhou, 510006, China.
² Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.
³ Environmental Microbiomics Research Center, School of Environmental Science and Engineering, School of Ecology, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), State Key Laboratory for Biocontrol, Sun Yat-Sen University, Guangzhou, 510006, China. yanqingyun@sml-zhuhai.cn.

Abstract

Background: Increasing attention has recently been devoted to the anaerobic ammonium oxidation (anammox) in eutrophic lakes due to its potential key functions in nitrogen (N) removal for eutrophication control. However, successful enrichment of anammox bacteria from lake sediments is still challenging, partly due to the ecological interactions between anammox and denitrifying bacteria across such enrichment with lake sediments remain unclear.

Results: This study thus designed to fill such knowledge gaps using bioreactors to enrich anammox bacteria with eutrophic lake sediments for more than 365 days. We continuously monitored the influent and effluent water, measured the anammox and denitrification efficiencies, quantified the anammox and denitrifying bacteria, as well as the related N cycling genes. We found that the maximum removal efficiencies of NH₄⁺ and NO₂^- reached up to 85.92% and 95.34%, respectively. Accordingly, the diversity of anammox and denitrifying bacteria decreased significantly across the enrichment, and the relative dominant anammox (e.g., Candidatus Jettenia) and denitrifying bacteria (e.g., Thauera, Afipia) shifted considerably. The ecological cooperation between anammox and denitrifying bacteria tended to increase the microbial community stability, indicating a potential coupling between anammox and denitrifying bacteria. Moreover, the nirS-type denitrifiers showed stronger coupling with anammox bacteria than that of nirK-type denitrifiers during the enrichment. Functional potentials as depicted by metagenome sequencing confirmed the ecological interactions between anammox and denitrification. Metagenome-assembled genomes-based ecological model indicated that the most dominant denitrifiers could provide various materials such as amino acid, cofactors, and vitamin for anammox bacteria. Cross-feeding in anammox and denitrifying bacteria highlights the importance of microbial interactions for increasing the anammox N removal in eutrophic lakes.

Conclusions: This study greatly expands our understanding of cooperation mechanisms among anammox and denitrifying bacteria during the anammox enrichment with eutrophic lake sediments, which sheds new insights into N removal for controlling lake eutrophication. Video Abstract.

Keywords: Anammox enrichment; Denitrification; Lake; Metagenome sequencing; Microbial interactions.

Publication types

Video-Audio Media
Research Support, Non-U.S. Gov't

MeSH terms

Anaerobic Ammonia Oxidation
Bacteria / genetics
Bacteria / metabolism
Bioreactors / microbiology
Denitrification*
Lakes* / microbiology
Oxidation-Reduction