Microbial interactions facilitating efficient methane driven denitrification via in-situ utilization of short chain fatty acids

Zihan Wang; Chuan Chen; Minli Xiong; Jingyan Tan; Kaikai Wu; Heng Liu; De-Feng Xing; Aijie Wang; Nanqi Ren; Lei Zhao

doi:10.1016/j.scitotenv.2024.172901

Microbial interactions facilitating efficient methane driven denitrification via in-situ utilization of short chain fatty acids

Sci Total Environ. 2024 Apr 30:931:172901. doi: 10.1016/j.scitotenv.2024.172901. Online ahead of print.

Authors

Zihan Wang¹, Chuan Chen¹, Minli Xiong¹, Jingyan Tan¹, Kaikai Wu¹, Heng Liu², De-Feng Xing¹, Aijie Wang³, Nanqi Ren¹, Lei Zhao⁴

Affiliations

¹ State Key Laboratory of Urban Water Resources and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
² School of Biopharmaceuticals, Heilongjiang Agricultural Engineering Vocational College, Harbin 150090, China.
³ Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. Electronic address: ajwang@rcees.ac.cn.
⁴ State Key Laboratory of Urban Water Resources and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China. Electronic address: lzhao@hit.edu.cn.

PMID: 38697549
DOI: 10.1016/j.scitotenv.2024.172901

Abstract

High nitrate pollution in agriculture and industry poses a challenge to emerging methane oxidation coupled denitrification. In this study, an efficient nitrate removal efficiency of 100 % was achieved at an influent loading rate of 400 mg-N/L·d, accompanied by the production of short chain fatty acids (SCFAs) with a maximum value of 80.9 mg/L. Batch tests confirmed that methane was initially converted to acetate, which then served as a carbon source for denitrification. Microbial community characterization revealed the dominance of heterotrophic denitrifiers, including Simplicispira (22.8 %), Stappia (4.9 %), and the high‑nitrogen-tolerant heterotrophic denitrifier Diaphorobacter (19.0 %), at the nitrate removal rate of 400 mg-N/L·d. Notably, the low abundance of methanotrophs ranging from 0.24 % to 3.75 % across all operational stages does not fully align with the abundance of pmoA genes, suggesting the presence of other functional microorganisms capable of methane oxidation and SCFAs production. These findings could facilitate highly efficient denitrification driven by methane and contributed to the development of denitrification using methane as an electron donor.

Keywords: CH(4); Denitrification; MBfR; Methane oxidation; SCFAs.