Research on microbial structures, functions and metabolic pathways in an advanced denitrification system coupled with aerobic methane oxidation based on metagenomics

Dengping Liu; Yanan Yang; Jia Ai; Yancheng Li; Yi Xing; Jiang Li

doi:10.1016/j.biortech.2021.125047

Research on microbial structures, functions and metabolic pathways in an advanced denitrification system coupled with aerobic methane oxidation based on metagenomics

Bioresour Technol. 2021 Jul:332:125047. doi: 10.1016/j.biortech.2021.125047. Epub 2021 Mar 26.

Authors

Dengping Liu¹, Yanan Yang², Jia Ai¹, Yancheng Li³, Yi Xing⁴, Jiang Li⁵

Affiliations

¹ College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang 500025, China.
² College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang 500025, China; Sinopec Great Wall Energy and Chemical (Guizhou) Co., LTD, Zhijin, Guizhou 552100, China.
³ College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang 500025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang, Guizhou 550025, China. Electronic address: ycli3@gzu.edu.cn.
⁴ College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang 500025, China; School of Energy and Environmental Engineering, University of Science & Technology Beijing, Beijing 100083, China.
⁵ College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang 500025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang, Guizhou 550025, China.

PMID: 33839509
DOI: 10.1016/j.biortech.2021.125047

Abstract

Methanotrophs can oxidize methane as the sole carbon and energy, and the resulting intermediate products can be simultaneously utilized by coexistent denitrifying bacteria to remove the nitrogen, which named Aerobic Methane Oxidation Coupled to Denitrification (AME-D). In this paper, an AME-D system was built in an improved denitrification bio-filter, to analyze the nitrogen removal efficiency and mechanism. The maximum TN removal rate reached 95.05%. As shown in Raman spectroscopy, in the effluent wave crests generated by the symmetric expansion and contraction of NO₃^- disappeared, and the distortion of olefin CH₂ and C-OH stretching of alcohols appeared. Metagenomics revealed Methylotenera and Methylobacter were the dominated methanotrophs. There was a completed methane and nitrogen metabolism pathway with the synergism of nxrAB, narGHI, nasAB, pmo-amoABC and mmo genes. Dissimilatory reduction pathway was the primary nitrate removal pathway. Moreover, Bradyrhizobium could participate in methane and nitrogen metabolism simultaneously.

Keywords: Advanced nitrogen removal; Metagenomics; Methanotrophs; Raman spectroscopy; Tail water.

MeSH terms

Bioreactors
Denitrification*
Metabolic Networks and Pathways
Metagenomics
Methane*
Nitrogen
Oxidation-Reduction

Substances

Nitrogen
Methane