Simultaneous removal of nitrogen and arsenite by heterotrophic nitrification and aerobic denitrification bacterium Hydrogenophaga sp. H7

Frontiers in Microbiology

Microbiology

Yongliang Zheng¹  Li Nie²  Zhengjun Chen²  Kaixiang Shi²  Gejiao Wang²  Xia Fan³ 

[1] College of Biology and Agricultural Resources, Huanggang Normal University, Huanggang, China;State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China;State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China;College of Biology and Agricultural Resources, Huanggang Normal University, Huanggang, China;

关键词: Hydrogenophaga;    nitrogen removal;    arsenite oxidation;    wastewater microbial treatment;    cocontamination;   

DOI  :  10.3389/fmicb.2022.1103913

 received in 2022-11-21, accepted in 2022-12-08,  发布年份 2023

来源: Frontiers

【 摘 要 】

IntroductionNitrogen and arsenic contaminants often coexist in groundwater, and microbes show the potential for simultaneous removal of nitrogen and arsenic. Here, we reported that Hydrogenophaga sp. H7 was heterotrophic nitrification and aerobic denitrification (HNAD) and arsenite [As(III)] oxidation bacterium.MethodsThe appearance of nitrogen removal and As(III) oxidation of Hydrogenophaga sp. H7 in liquid culture medium was studied. The effect of carbon source, C/N ratio, temperature, pH values, and shaking speeds were analyzed. The impact of strains H7 treatment with FeCl3 on nitrogen and As(III) in wastewater was assessed. The key pathways that participate in simultaneous nitrogen removal and As(III) oxidation was analyzed by genome and proteomic analysis.Results and discussionStrain H7 presented efficient capacities for simultaneous NH4+-N, NO3−-N, or NO2−-N removal with As(III) oxidation during aerobic cultivation. Strikingly, the bacterial ability to remove nitrogen and oxidize As(III) has remained high across a wide range of pH values, and shaking speeds, exceeding that of the most commonly reported HNAD bacteria. Additionally, the previous HNAD strains exhibited a high denitrification efficiency, but a suboptimal concentration of nitrogen remained in the wastewater. Here, strain H7 combined with FeCl3 efficiently removed 96.14% of NH4+-N, 99.08% of NO3−-N, and 94.68% of total nitrogen (TN), and it oxidized 100% of As(III), even at a low nitrogen concentration (35 mg/L). The residues in the wastewater still met the V of Surface Water Environmental Quality Standard of China after five continuous wastewater treatment cycles. Furthermore, genome and proteomic analyses led us to propose that the shortcut nitrification-denitrification pathway and As(III) oxidase AioBA are the key pathways that participate in simultaneous nitrogen removal and As(III) oxidation.

【 授权许可】

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Copyright © 2023 Fan, Nie, Chen, Zheng, Wang and Shi.