Research on microbial structures, functions and metabolic pathways in an advanced denitrification system coupled with aerobic methane oxidation based on metagenomics. (July 2021)

• Record Type: Journal Article
• Authors: Liu, Dengping; Yang, Yanan; Ai, Jia; Li, Yancheng; Xing, Yi; Li, Jiang
• Is Part Of: Bioresource technology. Volume 332(2021)
• Publication Date: 2021-07
• Subjects: Methanotrophs -- Metagenomics -- Raman spectroscopy -- Tail water -- Advanced nitrogen removal; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2021.125047
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: An AME-D system was built in an improved denitrification bio-filter. Methylotenera predominate in the AME-D system. The nitrogen removal mechanism in AME-D system was analyzed based on metagenomics. Metabolism pathway were elucidated from the functional genes and enzymes perspective. Bradyrhizobium participated in methane and nitrogen metabolism simultaneously. 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.