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Ju CJ, Niyazi S, Cao WY, Wang Q, Chen RP, Yu L. Characteristics and comparisons of the aerobic and anaerobic denitrification of a Klebsiella oxytoca strain: Performance, electron transfer pathway, and mechanism. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 338:117787. [PMID: 36965422 DOI: 10.1016/j.jenvman.2023.117787] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 03/10/2023] [Accepted: 03/20/2023] [Indexed: 06/18/2023]
Abstract
The performance and electron (e-) transfer mechanisms of anaerobic and aerobic denitrification by strain Klebsiella were investigated in this study. The RT-PCR results demonstrated that the membrane bound nitrate reductase gene (narG) and Cu-nitrite reductase gene (nirK) were responsible for both aerobic and anerobic denitrification. The extreme low gene relative abundance of nirK might be responsible for the severe accumulation of NO2--N (nitrogen in the form of NO2- ion) under anaerobic condition. Moreover, the nitrite reductase (Nir) activity was 0.31 μg NO2--N min-1 mg-1 protein under anaerobic conditions, which was lower than that under aerobic conditions (0.38 μg NO2--N min-1 mg-1 protein). By using respiration chain inhibitors, the e- transfer pathways of anaerobic and aerobic denitrification of Klebsiella strain were constructed. Fe-S protein and Complex III were the core components under anaerobic conditions, while Coenzyme Q (CoQ), Complexes I and III played a key role in aerobic denitrification. Nitrogen assimilation was found to be the main way to generate NH4+-N (nitrogen in the form of NH4+ ion) during anaerobic denitrification, and also served as the primary nitrogen removal way under aerobic condition. The results of this study may help to improve the understanding of the core components of strain Klebsiella during aerobic and anaerobic denitrifications, and may suggest potential applications of the strain for nitrogen-containing wastewater.
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Affiliation(s)
- Cheng-Jia Ju
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China; College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China
| | - Shareen Niyazi
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China
| | - Wen-Yin Cao
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China
| | - Quan Wang
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China
| | - Rong-Ping Chen
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China
| | - Lei Yu
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China; College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China.
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Cheng WX, Wang LL, Xu Y, Li SJ, Wang Q, Chen RP, Yu L. Performance and mechanism of different pretreatment methods for inoculated sludge in biohydrogen production. BIORESOURCE TECHNOLOGY 2023:129234. [PMID: 37244304 DOI: 10.1016/j.biortech.2023.129234] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Revised: 05/19/2023] [Accepted: 05/21/2023] [Indexed: 05/29/2023]
Abstract
A comparison was conducted between pre-culture bacteria (PCB) and heat treatment anaerobic granular sludge (HTAGS) for hydrogen production, and it was found that hydrogen molar yield (HMY) of PCB was 21-35% higher than that of HTAGS. The addition of biochar increased hydrogen production in both cultivation methods by acting as an electron shuttle to enhance extracellular electron transfers of Clostridium and Enterobacter. On the other hand, Fe3O4 did not promote hydrogen production in PCB experiments but had a positive effect on HTAGS experiments. This was due to the fact that PCB was mainly composed of Clostridium butyricum, which could not reduce extracellular iron oxide, resulting in a lack of respiratory driving force. In contrast, HTAGS retained a significant amount of Enterobacter, which possess the ability of extracellular anaerobic respiration. Different pretreatment methods of inoculum resulted in significant changes in the sludge community, thus exerting a noticeable impact on biohydrogen production.
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Affiliation(s)
- Wei-Xin Cheng
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China; College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China
| | - Ling-Ling Wang
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China
| | - Yun Xu
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China
| | - Si-Jia Li
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China
| | - Quan Wang
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China; College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China
| | - Rong-Ping Chen
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China
| | - Lei Yu
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China; College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China.
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Yu L, Ju CJ, Jing KY, Wang ZY, Niyazi S, Wang Q. The role of anthraquinone-2-sulfonate on intra/extracellular electron transfer of anaerobic nitrate reduction. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 333:117455. [PMID: 36758409 DOI: 10.1016/j.jenvman.2023.117455] [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: 12/23/2022] [Revised: 01/31/2023] [Accepted: 02/02/2023] [Indexed: 06/18/2023]
Abstract
To improve the electron (e-) transfer efficiency, exogenous redox mediators (RMs) were usually employed to enhance the denitrification efficiency due to the electron shuttling. Previous studies were mainly focused on how to improve the extracellular electron transfer (EET) by exogenous RMs. However, the intracellular electron transfer (IET), another crucial e- transfer pathway, of biological denitrification was scarcely reported, especially for the relationship between the denitrification and IET. In this study, Coenzyme Q, Complexes I, II and III were determined as the core components in the IET chain of denitrification by using four specific respiration chain inhibitors (RCIs). Anthraquinone-2-sulfonate (AQS) partially recovered the IET of denitrification from NO3--N to N2 gas when the RCIs were added. Specifically, the generations of N2 gas were improved by 9.68%-18.25% in the experiments with RCIs and AQS, comparing to that with RCIs. nrfA gene was not detected by reverse transcription-polymerase chain reaction, suggesting that Klebsiella oxytoca strain could not conduct dissimilatory nitrate reduction to ammonium. Nitrate assimilation was considered as the main NH4+-N formation way of K. oxytoca strain. The two e- transfer pathways of denitrification were constructed and the roles of AQS on the IET and EET of denitrification were specifically discussed. The results of this study provided a better understanding of the e- transfer pathways of denitrification, and suggested a potential practical use of exogenous RM on bio-treatment of nitrate-containing wastewater.
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Affiliation(s)
- Lei Yu
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China; College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China
| | - Cheng-Jia Ju
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China
| | - Kai-Yan Jing
- College of Ecology and Environmental Sciences, East China Normal University, Shanghai, 200241, China
| | - Zi-Yang Wang
- Soil Environment Research Institute, Jiangsu Provincial Academy of Environmental Science, 210003, Nanjing, China
| | - Shareen Niyazi
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China
| | - Quan Wang
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China; College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China.
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Tan Z, Yang X, Liu Y, Chen L, Xu H, Li Y, Gong B. The capability of chloramphenicol biotransformation of Klebsiella sp. YB1 under cadmium stress and its genome analysis. CHEMOSPHERE 2023; 313:137375. [PMID: 36435315 DOI: 10.1016/j.chemosphere.2022.137375] [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: 06/05/2022] [Revised: 09/30/2022] [Accepted: 11/22/2022] [Indexed: 06/16/2023]
Abstract
Co-contamination by antibiotics and heavy metal is common in the environment, however, there is scarce information about antibiotics biodegradation under heavy metals stress. In this study, Klebsiella sp. Strain YB1 was isolated which is capable of biodegrading chloramphenicol (CAP) with a biodegradation efficiency of 22.41% at an initial CAP of 10 mg L-1 within 2 days. CAP biodegradation which fitted well with the first-order kinetics. YB1 still degrades CAP under Cd stress, however 10 mg L-1 Cd inhibited CAP biodegradation by 15.1%. Biotransformation pathways remained the same under Cd stress, but two new products (Cmpd 19 and Cmpd 20) were identified. Five parallel metabolism pathways of CAP were proposed with/without Cd stress, including one novel pathway (pathway 5) that has not been reported before. In pathway 5, the initial reaction was oxidation of CAP by disruption of C-C bond at the side chain of C1 and C2 with the formation of 4-nitrobenzyl alcohol and CY7, then these intermediates were oxidized into p-nitrobenzoic acid and CY1, respectively. CAP acetyltransferase and nitroreductase and 2,3/4,5-dioxygenase may play an important role in CAP biodegradation through genome analysis and prediction. This study deepens our understanding of mechanism of antibiotic degradation under heavy metal stress in the environment.
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Affiliation(s)
- Zewen Tan
- College of Natural Resources and Environment, Joint Institute for Environment & Education, South China Agricultural University, Guangzhou, 510642, PR China
| | - Xiuyue Yang
- College of Natural Resources and Environment, Joint Institute for Environment & Education, South China Agricultural University, Guangzhou, 510642, PR China
| | - Yiling Liu
- College of Natural Resources and Environment, Joint Institute for Environment & Education, South China Agricultural University, Guangzhou, 510642, PR China
| | - Lian Chen
- College of Natural Resources and Environment, Joint Institute for Environment & Education, South China Agricultural University, Guangzhou, 510642, PR China
| | - Huijuan Xu
- College of Natural Resources and Environment, Joint Institute for Environment & Education, South China Agricultural University, Guangzhou, 510642, PR China
| | - Yongtao Li
- College of Natural Resources and Environment, Joint Institute for Environment & Education, South China Agricultural University, Guangzhou, 510642, PR China
| | - Beini Gong
- College of Natural Resources and Environment, Joint Institute for Environment & Education, South China Agricultural University, Guangzhou, 510642, PR China.
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Yu L, Cheng WX, Wang Q. The enhancement on biohydrogen production by the driving forces from extracellular iron oxide respiration. BIORESOURCE TECHNOLOGY 2022; 361:127679. [PMID: 35878766 DOI: 10.1016/j.biortech.2022.127679] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 07/18/2022] [Accepted: 07/19/2022] [Indexed: 06/15/2023]
Abstract
Biohydrogen productions from xylose and glucose under dark condition were enhanced by the presence of natural Fe3O4. The electron equivalent of H2 fractions accounted for 4.55 % and 5.69 % of the total given xylose and glucose in the experiments without Fe3O4, and that were correspondingly increased to 5.14 % and 6.50 % in the experiments with 100 mg/L of Fe3O4, respectively. Moreover, Fe3O4 increased the total intracellular NAD(H) concentrations by 8.84 % and 8.37 %, and boosted the ratios of NADH/NAD+ by 8.33 % and 17.72 % in xylose and glucose fermentation, respectively, comparing to the corresponding control experiments. The formation of electron couples of Fe(III)/Fe(II) during the iron oxide respiration and more generation of active extracellular polymeric substances components were determined as the important reasons for the improved biohydrogen production performance. Thus, a promotion mechanism of the internal "driving forces" from extracellular iron oxide respiration on the biohydrogen production was proposed.
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Affiliation(s)
- Lei Yu
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China; College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China
| | - Wei-Xin Cheng
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China
| | - Quan Wang
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China; College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China.
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Deng Y, Zhang K, Zou J, Li X, Wang Z, Hu C. Electron shuttles enhanced the removal of antibiotics and antibiotic resistance genes in anaerobic systems: A review. Front Microbiol 2022; 13:1004589. [PMID: 36160234 PMCID: PMC9490129 DOI: 10.3389/fmicb.2022.1004589] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 08/19/2022] [Indexed: 11/13/2022] Open
Abstract
The environmental and epidemiological problems caused by antibiotics and antibiotic resistance genes have attracted a lot of attention. The use of electron shuttles based on enhanced extracellular electron transfer for anaerobic biological treatment to remove widespread antibiotics and antibiotic resistance genes efficiently from wastewater or organic solid waste is a promising technology. This paper reviewed the development of electron shuttles, described the mechanism of action of different electron shuttles and the application of enhanced anaerobic biotreatment with electron shuttles for the removal of antibiotics and related genes. Finally, we discussed the current issues and possible future directions of electron shuttle technology.
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Chang ZY, Wang ZY, Zhang R, Yu L. Acceleration of biotic decolorization and partial mineralization of methyl orange by a photo-assisted n-type semiconductor. CHEMOSPHERE 2022; 291:132846. [PMID: 34767853 DOI: 10.1016/j.chemosphere.2021.132846] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 10/19/2021] [Accepted: 11/07/2021] [Indexed: 06/13/2023]
Abstract
In this study, a n-type semiconductor perylene diimide (PDI) was coupled with biodegradation to accelerate the biotic decolorization and mineralization of methyl orange (MO) under light condition. The decolorization rates (k1) of MO in pure and mixed cultures with PDI were promoted by 1.35 and 1.79 folds, respectively, comparing to the cultures without PDI. The total mineralization efficiency of 4-aminobenzenesulfonic acid (4-ABA) was achieved to 22.10 ± 0.84% when in the presence of PDI. The quinone-like group and oxidation-reduction capacity of PDI were detected by Fourier transform infrared spectroscopy and cyclic voltammetry, respectively, but the enhancement on the biotic decolorization of MO was not promoted under dark condition indicating that microbial extracellular electron transfer was not promoted. The 4-ABA was confirmed to be partially mineralized when the PDI exposure to light. The generated free radicals i.e., h+, ⸱OH, was demonstrated as active species to accelerate the decolorization and mineralization of MO by ESR test and radical quenching experiments. The bond breaking of MO and 4-ABA molecules were successfully predicted by density functional theory calculations and were further proven by liquid-chromatography mass spectra. The synergistic mechanism of decolorization and mineralization of MO by microorganism and photocatalysis was proposed. Moreover, High-throughput sequencing and Live/dead cell results indicated that the presence of PDI has no obvious toxicity to the microorganisms and will not change the microbial communities during the short-term treatment period. The results of study provided a biological intimate photocatalytic material and suggested a feasible way for its combination with biodegradation of azo dyes.
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Affiliation(s)
- Zhong-Yue Chang
- Department of Environmental Engineering, Nanjing Forestry University, Nanjing, 210037, China
| | - Zi-Yang Wang
- Department of Environmental Engineering, Nanjing Forestry University, Nanjing, 210037, China
| | - Rui Zhang
- Department of Environmental Engineering, Nanjing Forestry University, Nanjing, 210037, China
| | - Lei Yu
- Department of Environmental Engineering, Nanjing Forestry University, Nanjing, 210037, China.
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