Nitrate removal characteristics and 13C metabolic pathways of aerobic denitrifying bacterium Paracoccus denitrificans Z195

Haihan Zhang; Sulin Li; Ben Ma; Tinglin Huang; Hui Qiu; Zhenfang Zhao; Xin Huang; Kaiwen Liu

doi:10.1016/j.biortech.2020.123230

Nitrate removal characteristics and ¹³C metabolic pathways of aerobic denitrifying bacterium Paracoccus denitrificans Z195

Bioresour Technol. 2020 Jul:307:123230. doi: 10.1016/j.biortech.2020.123230. Epub 2020 Mar 20.

Authors

Haihan Zhang¹, Sulin Li², Ben Ma², Tinglin Huang², Hui Qiu³, Zhenfang Zhao², Xin Huang², Kaiwen Liu²

Affiliations

¹ Shaanxi Key Laboratory of Environmental Engineering, Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China. Electronic address: zhanghaihan@xauat.edu.cn.
² Shaanxi Key Laboratory of Environmental Engineering, Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China.
³ Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing 210044, China.

PMID: 32222687
DOI: 10.1016/j.biortech.2020.123230

Abstract

Strain Z195 was isolated and identified as Paracoccus denitrificans. Z195 exhibited efficient aerobic denitrification and carbon removal abilities, and removed 93.74% of total nitrogen (TN) and 97.81% of total organic carbon.71.88% of nitrogen was lost as gaseous products.¹³C-metabolic flux analysis revealed that 95% and 132% of the carbon fluxes entered the Entner-Doudoroff (ED) pathway and tricarboxylic acid (TCA) cycle, respectively. Electrons produced by carbon metabolism markedly promoted the processes of nitrogen metabolism process and aerobic respiration. A response surface methodology model demonstrated that the optimal conditions for the maximum TN removal were a C/N ratio of 7.47, shaking speed of 108 rpm, temperature of 31 °C and initial pH of 8.02. Additionally, the average TN and chemical oxygen demand removal efficiencies of raw wastewater were 89% and 91%, respectively. The results give new insight for understanding metabolic flux analysis of aerobic denitrifying bacteria.

Keywords: Aerobic denitrifying; Nitrate removal; Paracoccus denitrificans; Stable isotopic labeling.

MeSH terms

Aerobiosis
Bacteria
Denitrification
Metabolic Networks and Pathways
Nitrates
Nitrification
Nitrogen
Paracoccus denitrificans*

Substances

Nitrates
Nitrogen