Exploring influence mechanism of small-molecule carbon source on heterotrophic nitrification-aerobic denitrification process from carbon metabolism, nitrogen metabolism and electron transport process

Juntong Leng; Jiyan Lu; Chao Hai; Xinyi Liu; Pei Wu; Yan Sun; Chunbo Yuan; Jianqiang Zhao; Bo Hu

doi:10.1016/j.biortech.2023.129681

Exploring influence mechanism of small-molecule carbon source on heterotrophic nitrification-aerobic denitrification process from carbon metabolism, nitrogen metabolism and electron transport process

Bioresour Technol. 2023 Nov:387:129681. doi: 10.1016/j.biortech.2023.129681. Epub 2023 Aug 14.

Authors

Juntong Leng¹, Jiyan Lu¹, Chao Hai¹, Xinyi Liu¹, Pei Wu², Yan Sun¹, Chunbo Yuan¹, Jianqiang Zhao³, Bo Hu⁴

Affiliations

¹ School of Civil Engineering, Chang'an University, The Middle Section of the South 2(nd) Ring Road, 710064 Xi'an, Shaanxi Province, China; Key Laboratory of Water Supply & Sewage Engineering, Ministry of Housing and Urban-rural Development Chang'an University, The Middle Section of the South 2(nd) Ring Road, 710064 Xi'an, Shaanxi Province, China.
² School of Civil Engineering, Chang'an University, The Middle Section of the South 2(nd) Ring Road, 710064 Xi'an, Shaanxi Province, China; Key Laboratory of Water Supply & Sewage Engineering, Ministry of Housing and Urban-rural Development Chang'an University, The Middle Section of the South 2(nd) Ring Road, 710064 Xi'an, Shaanxi Province, China. Electronic address: peterwoody@chd.edu.cn.
³ Key Laboratory of Water Supply & Sewage Engineering, Ministry of Housing and Urban-rural Development Chang'an University, The Middle Section of the South 2(nd) Ring Road, 710064 Xi'an, Shaanxi Province, China; School of Water and Environment, Chang'an University, The Middle Section of the South 2(nd) Ring Road, 710064 Xi'an, Shaanxi Province, China.
⁴ School of Civil Engineering, Chang'an University, The Middle Section of the South 2(nd) Ring Road, 710064 Xi'an, Shaanxi Province, China; Key Laboratory of Water Supply & Sewage Engineering, Ministry of Housing and Urban-rural Development Chang'an University, The Middle Section of the South 2(nd) Ring Road, 710064 Xi'an, Shaanxi Province, China. Electronic address: hubo1983@chd.edu.cn.

PMID: 37586428
DOI: 10.1016/j.biortech.2023.129681

Abstract

The heterotrophic nitrification-aerobic denitrification (HNAD) process can remove nitrogen and organic carbon under aerobic conditions. To get the in-depth mechanism of the HAND process, a strain named Acinetobacter johnsonii ZHL01 was isolated, and enzyme activity, electron transport, energy production, and gene expression of the strain were studied with small-molecule carbon sources, including sodium citrate, sodium acetate, sodium fumarate, and sodium succinate. The HNAD pathway of ZHL01 was NH₄⁺→NH₂OH → NO, and nitrogen balance analysis shows that ZHL01 could assimilate and denitrify 58.29 ± 1.05 % and 16.58 ± 1.07 % of nitrogen, respectively. The assimilation, the nitrification/denitrification, and the respiration processes were regulated by the concentration of reduced nicotinamide adenine dinucleotide (NADH) produced from the different metabolic pathways of small-molecule carbon sources. The HNAD process occurs to reduce intracellular redox levels related to NADH concentrations. This discovery provides a theoretical basis for the practical application of HAND bacteria.

Keywords: Carbon source; Electron transport; Enzyme activity; Heterotrophic nitrification-aerobic denitrification; Prokaryotic strand specific transcriptome.

MeSH terms

Aerobiosis
Carbon / metabolism
Denitrification*
Electron Transport
Heterotrophic Processes
NAD / metabolism
Nitrification*
Nitrites / metabolism
Nitrogen / metabolism

Substances

Carbon
NAD
Nitrogen
Nitrites