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Tahovská K, Kaštovská E, Choma M, Čapek P, Bárta J, Oulehle F. Ammonia oxidation and nitrate reduction marker genes are key indicators of nitrogen losses in temperate forest catchments. Environ Microbiol 2023; 25:2049-2053. [PMID: 37286495 DOI: 10.1111/1462-2920.16441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Accepted: 05/30/2023] [Indexed: 06/09/2023]
Abstract
Chronic nitrogen inputs can alleviate N limitation and potentially impose N losses in forests, indicated by soil enrichment in 15 N over 14 N. However, the complexity of the nitrogen cycle hinders accurate quantification of N fluxes. Simultaneously, soil ecologists are striving to find meaningful indicators to characterise the "openness" of the nitrogen cycle. We integrate soil δ15 N with constrained ecosystem N losses and the functional gene potential of the soil microbiome in 14 temperate forest catchments. We show that N losses are associated with soil δ15 N and that δ15 N scales with the abundance of soil bacteria. The abundance of the archaeal amoA gene, representing the first step in nitrification (ammonia oxidation to nitrite), followed by the abundance of narG and napA genes, associated with the first step in denitrification (nitrate reduction to nitrite), explains most of the variability in soil δ15 N. These genes are more informative than the denitrification genes nirS and nirK, which are directly linked to N2 O production. Nitrite formation thus appears to be the critical step associated with N losses. Furthermore, we show that the genetic potential for ammonia oxidation and nitrate reduction is representative of forest soil 15 N enrichment and thus indicative of ecosystem N losses.
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Affiliation(s)
- Karolina Tahovská
- Department of Ecosystem Biology, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Eva Kaštovská
- Department of Ecosystem Biology, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Michal Choma
- Department of Ecosystem Biology, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Petr Čapek
- Department of Ecosystem Biology, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Jiří Bárta
- Department of Ecosystem Biology, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Filip Oulehle
- Department of Environmental Geochemistry and Biogeochemistry, Czech Geological Survey, Prague, Czech Republic
- Department of Biogeochemical and Hydrological Cycles, Global Change Research Institute of the Czech Academy of Sciences, Brno, Czech Republic
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Huang L, Xiong H, Jiang C, He J, Lyu W, Chen Y. Pathways and biological mechanisms of N 2O emission reduction by adding biochar in the constructed wetland based on 15N stable isotope tracing. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 342:118359. [PMID: 37311348 DOI: 10.1016/j.jenvman.2023.118359] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 05/31/2023] [Accepted: 06/07/2023] [Indexed: 06/15/2023]
Abstract
Constructed wetlands (CWs) added with biochar were built to study pollutant removal efficiencies, nitrous oxide (N2O) emission characteristics, and biological mechanisms in nitrogen transformation. The results showed that biochar addition enhanced the average removal rates of ammonium (NH4+-N), total nitrogen, and chemical oxygen demand by 4.03-18.5%, 2.90-4.99%, and 2.87-5.20% respectively while reducing N2O emissions by 25.85-83.41%. Based on 15N stable isotope tracing, it was found that nitrification, denitrification, and simultaneous nitrification and denitrification were the main processes contributing to N2O emission. The addition of biochar resulted in maximum reduction rates of 71.50%, 80.66%, and 73.09% for these three processes, respectively. The relative abundance of nitrogen-transforming microbes, such as Nitrospira, Dechloromonas, and Denitratisoma, increased after the addition of biochar, promoting nitrogen removal and reducing N2O emissions. Adding biochar could increase the functional gene copy number and enzyme activity responsible for nitrogen conversion, which helped achieve efficient NH4+-N oxidation and eliminate nitrite accumulation, thereby reducing N2O emissions.
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Affiliation(s)
- Lei Huang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing, 400715, PR China; Chongqing Key Laboratory of Agricultural Resources and Environment, Chongqing, 400716, PR China; Chongqing Engineering Research Center of Rural Cleaner Production, Chongqing, 400716, PR China.
| | - Haifeng Xiong
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing, 400715, PR China; Chongqing Key Laboratory of Agricultural Resources and Environment, Chongqing, 400716, PR China
| | - Chunli Jiang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing, 400715, PR China; Chongqing Key Laboratory of Agricultural Resources and Environment, Chongqing, 400716, PR China
| | - Jinke He
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing, 400715, PR China; Chongqing Key Laboratory of Agricultural Resources and Environment, Chongqing, 400716, PR China
| | - Wanlin Lyu
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing, 400715, PR China; Chongqing Key Laboratory of Agricultural Resources and Environment, Chongqing, 400716, PR China
| | - Yucheng Chen
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing, 400715, PR China; Chongqing Key Laboratory of Agricultural Resources and Environment, Chongqing, 400716, PR China; Chongqing Engineering Research Center of Rural Cleaner Production, Chongqing, 400716, PR China
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Li Q, Xu Y, Liang C, Peng L, Zhou Y. Nitrogen removal by algal-bacterial consortium during mainstream wastewater treatment: Transformation mechanisms and potential N 2O mitigation. WATER RESEARCH 2023; 235:119890. [PMID: 36958220 DOI: 10.1016/j.watres.2023.119890] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 02/08/2023] [Accepted: 03/17/2023] [Indexed: 06/18/2023]
Abstract
This work investigated nitrogen transformation pathways of the algal-bacterial consortium as well as its potential in reducing nitrous oxide (N2O) emission in enclosed, open and aerated reactors. The results confirmed the superior ammonium removal performance of the algal-bacterial consortium relative to the single algae (Chlorella vulgaris) or the activated sludge, achieving the highest efficiency at 100% and the highest rate of 7.34 mg N g MLSS-1 h-1 in the open reactor with glucose. Enhanced total nitrogen (TN) removal (to 74.6%) by the algal-bacterial consortium was achieved via mixotrophic algal assimilation and bacterial denitrification under oxygen-limited and glucose-sufficient conditions. Nitrogen distribution indicated that ammonia oxidation (∼41.8%) and algal assimilation (∼43.5%) were the main pathways to remove ammonium by the algal-bacterial consortium. TN removal by the algal-bacterial consortium was primarily achieved by algal assimilation (28.1-40.8%), followed by bacterial denitrification (2.9-26.5%). Furthermore, the algal-bacterial consortium contributed to N2O mitigation compared with the activated sludge, reducing N2O production by 35.5-55.0% via autotrophic pathways and by 81.0-93.6% via mixotrophic pathways. Nitrogen assimilation by algae was boosted with the addition of glucose and thus largely restrained N2O production from nitrification and denitrification. The synergism between algae and bacteria was also conducive to an enhanced N2O reduction by denitrification and reduced direct/indirect carbon emissions.
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Affiliation(s)
- Qi Li
- Hubei Key Laboratory of Mineral Resources Processing and Environment, Wuhan University of Technology, Luoshi Road 122, Wuhan 430070, China; School of Resources and Environmental Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan 430070, China
| | - Yifeng Xu
- Hubei Key Laboratory of Mineral Resources Processing and Environment, Wuhan University of Technology, Luoshi Road 122, Wuhan 430070, China; School of Resources and Environmental Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan 430070, China
| | - Chuanzhou Liang
- Hubei Key Laboratory of Mineral Resources Processing and Environment, Wuhan University of Technology, Luoshi Road 122, Wuhan 430070, China; School of Resources and Environmental Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan 430070, China
| | - Lai Peng
- Hubei Key Laboratory of Mineral Resources Processing and Environment, Wuhan University of Technology, Luoshi Road 122, Wuhan 430070, China; School of Resources and Environmental Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan 430070, China.
| | - Yan Zhou
- School of Civil and Environmental Engineering, Nanyang Technological University 639798, Singapore
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Tang Q, Zeng M, Zou W, Jiang W, Kahaer A, Liu S, Hong C, Ye Y, Jiang W, Kang J, Ren Y, Liu D. A new strategy to simultaneous removal and recovery of nitrogen from wastewater without N 2O emission by heterotrophic nitrogen-assimilating bacterium. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 872:162211. [PMID: 36791849 DOI: 10.1016/j.scitotenv.2023.162211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/23/2023] [Accepted: 02/09/2023] [Indexed: 06/18/2023]
Abstract
Biological assimilation that recovery the nitrogen from wastewater in the form of biomass offers a more environmentally friendly solution for the limitations of the conventional wastewater treatments. This study reported the simultaneous removal and recovery of nitrogen from wastewater without N2O emission by a heterotrophic nitrogen-assimilating Acinetobacter sp. DN1 strain. Nitrogen balance, biomass qualitative analysis, genome and enzyme studies have been performed to illustrate the mechanism of nitrogen conversion by strain DN1. Results showed that the ammonium removal followed one direct pathway (GOGAT/GDH) and three indirect pathways (NH4+ → NH2OH → NO → NO2- → NH4+ → GOGAT/GDH; NH4+ → NH2OH → NO → NO2- → NO3- → NO2- → NH4+ → GOGAT/GDH; NH4+ → NH2OH → NO → NO3- → NO2- → NH4+ → GOGAT/GDH). Nitrogen balance and biomass qualitative analysis showed that over 70 % of the ammonium in the wastewater was converted into intracellular nitrogen-containing compounds and stored in the cells of strain DN1. Traditional denitrification pathway was not detected and the ammonium was removed through assimilation, which makes it more energy-saving for nitrogen recovery when compared with Haber-Bosch process. This study provides a new direction for simultaneous nitrogen removal and recovery without N2O emission by the heterotrophic nitrogen-assimilating bacterium.
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Affiliation(s)
- Qian Tang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Wuhan 430074, PR China
| | - Mengjie Zeng
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Wuhan 430074, PR China; Wuhan Municipal Engineering Design & Research Institute Co., Ltd, No. 52 Optics Valley Avenue, Wuhan 430074, PR China
| | - Wugui Zou
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Wuhan 430074, PR China
| | - Wenyu Jiang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Wuhan 430074, PR China
| | - Alimu Kahaer
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Wuhan 430074, PR China
| | - Shixi Liu
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Wuhan 430074, PR China
| | - Chol Hong
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Wuhan 430074, PR China; Heat Engineering Faculty, Kim Chaek University of Technology, Pyongyang 999093, Democratic People's Republic of Korea
| | - Yuanyao Ye
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Wuhan 430074, PR China
| | - Wei Jiang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Wuhan 430074, PR China
| | - Jianxiong Kang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Wuhan 430074, PR China
| | - Yongzheng Ren
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Wuhan 430074, PR China
| | - Dongqi Liu
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Wuhan 430074, PR China.
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Yang R, Yuan L, Wang R. Enzymatic regulation of N 2O production by denitrifying bacteria in the sludge of biological nitrogen removal process. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 846:157513. [PMID: 35872196 DOI: 10.1016/j.scitotenv.2022.157513] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 07/14/2022] [Accepted: 07/16/2022] [Indexed: 06/15/2023]
Abstract
This study analyzed the activities of all denitrifying enzymes involved in the denitrification process under different organic loads in a continuously operating sequencing batch reactor (SBR), to reveal how the denitrifying enzymes performed while the denitrifying bacteria facing changes in organic load, and leading to nitrous oxide (N2O) production by fine-tuning enzyme activities. Results show that the activities of nitrate reductase (Nar), nitrite reductase (Nir), nitric oxide reductase (Nor) and nitrous oxide reductase (N2OR) increased with the increase of organic loads, and the increase of the activity of different enzymes promoted by the organic load increase were as Nar > Nir > Nor > N2OR. Compared with the Nar and Nir, the catalytic processes of the Nor and N2OR were more susceptible to the influence of the substrate concentration and the content of internal and external carbon sources. The Nor usually maintained "excess" catalytic activity to ensure the smooth reduction of nitric oxide when the electron donor and substrate were sufficient. Otherwise, it reduced to a relatively lower catalytic activity and remained stable. The activities of the N2OR were generally weaker than that of other denitrifying enzymes. More N2O was produced in the period feeding with low organic loads (COD/NO3--N ≤ 4.9). The mechanism of the enzyme activities (Nor and N2OR) regulating the total concentrations of N2O was clarified. When the organic load was relatively low (COD/NO3--N ≤ 2.5), the N2OR activity was inhibited due to its inability to acquire enough electrons, resulting the production of N2O. When the organic load was moderate (2.5 < COD/NO3--N ≤ 4.9), the N2OR activity was lower than the Nor activity due to the different activation rates of Nor and N2OR by the substrate in bacteria, resulting the production of N2O.
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Affiliation(s)
- Rui Yang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No.13 Yanta road, Xi'an 710055, PR China; Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, No.13 Yanta road, Xi'an 710055, PR China; Shaanxi Key Lab of Environmental Engineering, Xi'an 710055, PR China
| | - Linjiang Yuan
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No.13 Yanta road, Xi'an 710055, PR China; Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, No.13 Yanta road, Xi'an 710055, PR China; Shaanxi Key Lab of Environmental Engineering, Xi'an 710055, PR China.
| | - Ru Wang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No.13 Yanta road, Xi'an 710055, PR China; Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, No.13 Yanta road, Xi'an 710055, PR China; Shaanxi Key Lab of Environmental Engineering, Xi'an 710055, PR China
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Ye J, Gao H, Wu J, Zhan M, Yang G, Yu R. Transient disturbance of CeO2 nanoparticles enhances N2O emissions during biological wastewater treatment. Biochem Eng J 2022. [DOI: 10.1016/j.bej.2022.108620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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