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Gobezie MY, Hassen M, Tesfaye NA, Solomon T, Demessie MB, Kassa TD, Wendie TF, Andualem A, Alemayehu E, Belayneh YM. Prevalence of meropenem-resistant Pseudomonas Aeruginosa in Ethiopia: a systematic review and meta‑analysis. Antimicrob Resist Infect Control 2024; 13:37. [PMID: 38600535 PMCID: PMC11005134 DOI: 10.1186/s13756-024-01389-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Accepted: 03/23/2024] [Indexed: 04/12/2024] Open
Abstract
INTRODUCTION Antimicrobial resistance (AMR) is a pressing global health concern, particularly pronounced in low-resource settings. In Ethiopia, the escalating prevalence of carbapenem-resistant Pseudomonas aeruginosa (P. aeruginosa) poses a substantial threat to public health. METHODS A comprehensive search of databases, including PubMed, Scopus, Embase, Hinari, and Google Scholar, identified relevant studies. Inclusion criteria encompassed observational studies reporting the prevalence of meropenem-resistant P. aeruginosa in Ethiopia. Quality assessment utilized JBI checklists. A random-effects meta-analysis pooled data on study characteristics and prevalence estimates, with subsequent subgroup and sensitivity analyses. Publication bias was assessed graphically and statistically. RESULTS Out of 433 studies, nineteen, comprising a total sample of 11,131, met inclusion criteria. The pooled prevalence of meropenem-resistant P. aeruginosa was 15% (95% CI: 10-21%). Significant heterogeneity (I2 = 83.6%) was observed, with the number of P. aeruginosa isolates identified as the primary source of heterogeneity (p = 0.127). Subgroup analysis by infection source revealed a higher prevalence in hospital-acquired infections (28%, 95% CI: 10, 46) compared to community settings (6%, 95% CI: 2, 11). Geographic based subgroup analysis indicated the highest prevalence in the Amhara region (23%, 95% CI: 8, 38), followed by Addis Ababa (21%, 95% CI: 11, 32), and lower prevalence in the Oromia region (7%, 95% CI: 4, 19). Wound samples exhibited the highest resistance (25%, 95% CI: 25, 78), while sputum samples showed the lowest prevalence. Publication bias, identified through funnel plot examination and Egger's regression test (p < 0.001), execution of trim and fill analysis resulted in an adjusted pooled prevalence of (3.7%, 95% CI: 2.3, 9.6). CONCLUSION The noteworthy prevalence of meropenem resistance among P. aeruginosa isolates in Ethiopia, particularly in healthcare settings, underscores the urgency of implementing strict infection control practices and antibiotic stewardship. Further research is imperative to address and mitigate the challenges posed by antimicrobial resistance in the country.
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Affiliation(s)
- Mengistie Yirsaw Gobezie
- Department of Clinical Pharmacy, School of Pharmacy, College of Medicine and Health Sciences, Wollo University, Dessie, Ethiopia.
| | - Minimize Hassen
- Department of Clinical Pharmacy, School of Pharmacy, College of Medicine and Health Sciences, Wollo University, Dessie, Ethiopia
| | - Nuhamin Alemayehu Tesfaye
- Department of Clinical Pharmacy, School of Pharmacy, College of Medicine and Health Sciences, Wollo University, Dessie, Ethiopia
| | - Tewodros Solomon
- Department of Clinical Pharmacy, School of Pharmacy, College of Medicine and Health Sciences, Wollo University, Dessie, Ethiopia
| | - Mulat Belete Demessie
- Department of Clinical Pharmacy, School of Pharmacy, College of Medicine and Health Sciences, Wollo University, Dessie, Ethiopia
| | - Tesfaye Dessale Kassa
- Department of Clinical Pharmacy, College of Health Sciences, Mekelle University, Mekelle, Ethiopia
| | - Teklehaimanot Fentie Wendie
- Department of Clinical Pharmacy, School of Pharmacy, College of Medicine and Health Sciences, Wollo University, Dessie, Ethiopia
| | - Abel Andualem
- Department of Pharmacology, School of Pharmacy, College of Medicine and Health Sciences, Wollo University, Dessie, Ethiopia
| | - Ermiyas Alemayehu
- Department of Medical Laboratory Sciences, College of Medicine and Health Sciences, Wollo University, Dessie, Ethiopia
| | - Yaschilal Muche Belayneh
- Department of Pharmacology, School of Pharmacy, College of Medicine and Health Sciences, Wollo University, Dessie, Ethiopia
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Cheng W, Yin Y, Li Y, Li B, Liu D, Ye L, Fu C. Nitrogen removal by a strengthened comprehensive floating bed with embedded pellets made by a newly isolated Pseudomonas sp. Y1. ENVIRONMENTAL TECHNOLOGY 2024; 45:208-220. [PMID: 35876098 DOI: 10.1080/09593330.2022.2102940] [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: 05/24/2022] [Accepted: 07/09/2022] [Indexed: 06/15/2023]
Abstract
A newly heterotrophic nitrification aerobic denitrification(HN-AD) bacterium Pseudomonas sp. Y1 with highly nitrogen removal ability was isolated from the activated sludge, TN removal rate of which was 99.73%. In this study, two types of different ecology floating bed systems were designed to achieve efficient nitrogen removal in the urban eutrophic landscape water body, one is the comprehensive ecological floating bed(CEFB) system with only Lythrum salicari and the other is the strengthened comprehensive ecological floating bed (SCEFB) system with both Lythrum and embedded pellets made by Y1. The TN removal rates of the CEFB system were 33.82%, 83.84% and 88.91% at 8±1℃, 15±1℃ and 25±1℃, respectively, while the TN removal rates of the SCEFB system increased by nearly 40%, 16% and 11% at the same environment, respectively. The result shows that the SCEFB system can purify the simulated water from surface water body class V to class IV. Thus it has a broad application prospect in the urban eutrophic landscape water body.
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Affiliation(s)
- Wanyun Cheng
- School of Resource and Environmental Engineering, Wuhan University of Technology, Wuhan, People's Republic of China
| | - Yixin Yin
- School of Resource and Environmental Engineering, Wuhan University of Technology, Wuhan, People's Republic of China
- Shanghai Honess Environmental Technology Co.,Ltd., Shanghai, People's Republic of China
| | - Ye Li
- School of Resource and Environmental Engineering, Wuhan University of Technology, Wuhan, People's Republic of China
| | - Bolin Li
- School of Resource and Environmental Engineering, Wuhan University of Technology, Wuhan, People's Republic of China
| | - Dongxue Liu
- School of Resource and Environmental Engineering, Wuhan University of Technology, Wuhan, People's Republic of China
| | - Lingfeng Ye
- School of Resource and Environmental Engineering, Wuhan University of Technology, Wuhan, People's Republic of China
| | - Chengbin Fu
- School of Resource and Environmental Engineering, Wuhan University of Technology, Wuhan, People's Republic of China
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Valk LC, Peces M, Singleton CM, Laursen MD, Andersen MH, Mielczarek AT, Nielsen PH. Exploring the microbial influence on seasonal nitrous oxide concentration in a full-scale wastewater treatment plant using metagenome assembled genomes. WATER RESEARCH 2022; 219:118563. [PMID: 35594748 DOI: 10.1016/j.watres.2022.118563] [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: 02/11/2022] [Revised: 05/05/2022] [Accepted: 05/06/2022] [Indexed: 06/15/2023]
Abstract
Nitrous oxide is a highly potent greenhouse gas and one of the main contributors to the greenhouse gas footprint of wastewater treatment plants (WWTP). Although nitrous oxide can be produced by abiotic reactions in these systems, biological N2O production resulting from the imbalance of nitrous oxide production and reduction by microbial populations is the dominant cause. The microbial populations responsible for the imbalance have not been clearly identified, yet they are likely responsible for strong seasonal nitrous oxide patterns. Here, we examined the seasonal nitrous oxide concentration pattern in Avedøre WWTP alongside abiotic parameters, the microbial community composition based on 16S rRNA gene sequencing and already available metagenome-assembled genomes (MAGs). We found that the WWTP parameters could not explain the observed pattern. While no distinct community changes between periods of high and low dissolved nitrous oxide concentrations were determined, we found 26 and 28 species with positive and negative correlations to the seasonal N2O concentrations, respectively. MAGs were identified for 124 species (approximately 31% mean relative abundance of the community), and analysis of their genomic nitrogen transformation potential could explain this correlation for four of the negatively correlated species. Other abundant species were also analysed for their nitrogen transformation potential. Interestingly, only one full-denitrifier (Candidatus Dechloromonas phosphorivorans) was identified. 59 species had a nosZ gene predicted, with the majority identified as a clade II nosZ gene, mainly from the phylum Bacteroidota. A correlation of MAG-derived functional guilds with the N2O concentration pattern showed that there was a small but significant negative correlation with nitrite oxidizing bacteria and species with a nosZ gene (N2O reducers (DEN)). More research is required, specifically long-term activity measurements in relation to the N2O concentration to increase the resolution of these findings.
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Affiliation(s)
- Laura Christina Valk
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg, Denmark
| | - Miriam Peces
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg, Denmark
| | - Caitlin Margaret Singleton
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg, Denmark
| | - Mads Dyring Laursen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg, Denmark
| | | | | | - Per Halkjær Nielsen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg, Denmark.
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Song T, Zhang X, Li J, Wu X, Feng H, Dong W. A review of research progress of heterotrophic nitrification and aerobic denitrification microorganisms (HNADMs). THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 801:149319. [PMID: 34428659 DOI: 10.1016/j.scitotenv.2021.149319] [Citation(s) in RCA: 100] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 07/23/2021] [Accepted: 07/24/2021] [Indexed: 06/13/2023]
Abstract
Traditional nitrogen removal relies on the autotrophic nitrification and anaerobic denitrification process. In the system, autotrophic microorganisms achieve nitrification under aerobic condition and heterotrophic microorganisms complete the denitrification in anaerobic condition. As the two types of microorganisms have different tolerance on oxygen concentration, nitrification and denitrification are normally set in two compartments for high nitrogen removal. Therefore, large land occupying is required. In fact, there is a special type of microorganism called heterotrophic nitrification & aerobic denitrification microorganisms (HNADMs) which can oxidize ammonium nitrogen, and perform denitrification in the presence of oxygen. HNADMs have been reported in many environments. It was found that HNADMs could simultaneously achieve nitrification and denitrification. In addition, some HNADMs not only have the ability to remove nitrogen, but also have the ability to remove phosphorus. It suggests that HNADMs have great potential for pollution removal from wastewater. So far, individual work on single strain was carried out. Comprehensive summary of the HNADMs would provide a better picture for understanding and directing its application. In this paper, the studies related on HNADMs were reviewed. The nitrogen metabolism pathway of HNADMs was summarized. The impact of pH, DO, carbon source, and C/N on HNADMs growth and metabolism were discussed. In addition, the extracellular polymeric substance (EPS) production, quorum sensing (QS) secretion and P removal by HNADMs were displayed.
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Affiliation(s)
- Tao Song
- School of Civil and Environmental Engineering, Shenzhen Key Laboratory of Water Resource Application and Environmental Pollution Control, Harbin Institute of Technology, Shenzhen 518055, Guangdong, PR China
| | - Xiaolei Zhang
- School of Civil and Environmental Engineering, Shenzhen Key Laboratory of Water Resource Application and Environmental Pollution Control, Harbin Institute of Technology, Shenzhen 518055, Guangdong, PR China
| | - Ji Li
- School of Civil and Environmental Engineering, Shenzhen Key Laboratory of Water Resource Application and Environmental Pollution Control, Harbin Institute of Technology, Shenzhen 518055, Guangdong, PR China.
| | - Xinyu Wu
- School of Civil and Environmental Engineering, Shenzhen Key Laboratory of Water Resource Application and Environmental Pollution Control, Harbin Institute of Technology, Shenzhen 518055, Guangdong, PR China
| | - Haixia Feng
- Shenzhen Municipal Engineering Consulting Center CO., LTD, Shenzhen 518028, Guangdong, PR China
| | - Wenyi Dong
- School of Civil and Environmental Engineering, Shenzhen Key Laboratory of Water Resource Application and Environmental Pollution Control, Harbin Institute of Technology, Shenzhen 518055, Guangdong, PR China
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Fang S, Nan H, Lv D, You X, Chen J, Li C, Zhang J. Effects of sulfoxaflor on greenhouse vegetable soil N 2O emissions and its microbial driving mechanism. CHEMOSPHERE 2021; 267:129248. [PMID: 33321281 DOI: 10.1016/j.chemosphere.2020.129248] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 11/29/2020] [Accepted: 12/06/2020] [Indexed: 06/12/2023]
Abstract
The wide application of pesticides ensures the safety of food production, but it also has a serious impact on soil ecosystem. Although sulfoxaflor as a pesticide has great potential for application due to its excellent insecticidal activity and low crossresistance, little is known about its soil environmental safety risks. In this study, the effects of sulfoxaflor on N2O emissions and microorganisms in greenhouse vegetable soils were studied by indoor simulation culture experiments. Dynamic changes of soil main inorganic N and N2O emission rate were tested, and the abundance and community of total bacteria and microorganisms related to N cycle were analyzed. The results indicated that soil microorganisms rapidly degraded sulfoxaflor, and the N2O emissions rate and ammonium nitrogen (NH4+-N) content significantly increased, while nitrate nitrogen (NO3--N) content was significantly decreased. Sulfoxaflor significantly changed the abundance and community of total bacteria, nitrite reducing and nitrous oxide reducing bacteria, but had no significant effect on ammoxidation microorganisms. The N2O emission rate was positively correlated with gene abundance of denitrifying microorganisms. Under 65% soil maximum water holding capacity, sulfoxaflor may broke the dynamic balance of N2O production and consumption in the denitrification process, which caused a significant increase in N2O emission. Therefore, the application of sulfoxaflor had a certain effect on N cycling and utilization in greenhouse vegetable soil.
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Affiliation(s)
- Song Fang
- National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Tai'an, Shandong, 271018, China; Laboratory of Tobacco and Aromatic Plants Quality and Safety Risk Assessment, Ministry of Agriculture and Rural Affairs, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Hai Nan
- Laboratory of Tobacco and Aromatic Plants Quality and Safety Risk Assessment, Ministry of Agriculture and Rural Affairs, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Dongqing Lv
- National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Tai'an, Shandong, 271018, China
| | - Xiangwei You
- Laboratory of Tobacco and Aromatic Plants Quality and Safety Risk Assessment, Ministry of Agriculture and Rural Affairs, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Jianqiu Chen
- State Key Laboratory of Nutrition Resources Integrated Utilization, Kingenta Ecological Engineering Co., Ltd., Linshu, 276700, China
| | - Chengliang Li
- National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Tai'an, Shandong, 271018, China.
| | - Jiguang Zhang
- Laboratory of Tobacco and Aromatic Plants Quality and Safety Risk Assessment, Ministry of Agriculture and Rural Affairs, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao, 266101, China.
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6
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Neissi A, Rafiee G, Farahmand H, Rahimi S, Mijakovic I. Cold-Resistant Heterotrophic Ammonium and Nitrite-Removing Bacteria Improve Aquaculture Conditions of Rainbow Trout (Oncorhynchus mykiss). MICROBIAL ECOLOGY 2020; 80:266-277. [PMID: 32162039 PMCID: PMC7371659 DOI: 10.1007/s00248-020-01498-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 02/19/2020] [Indexed: 05/31/2023]
Abstract
The aim of this study was isolation and characterization of heterotrophic bacteria capable of ammonium and nitrite removal at 15 °C (optimal temperature for growing rainbow trout Oncorhynchus mykiss). Environmental isolates were grown in liquid media containing ammonium or nitrite, and best strains in terms of growth and ammonium or nitrite removal were identified via 16S rRNA sequencing. Dyadobacter sp. (no. 68) and Janthinobacterium sp. (no. 100) were selected for optimal adaptation to growth at 15 °C and best ammonium and nitrite removal (P < 0.05), respectively. A heterotrophic ammonium and nitrite removal (HAN) microbial complex, containing selected strains, was prepared and applied in a trout culture system. After 10 days, the effect of microbial HAN complex was investigated in terms of ammonium and nitrite removal, as well as stress and immune indices present in the plasma of cultivated trout. Compared to a standard cultivation setup, addition of the HAN complex had a clear beneficial effect on keeping the un-ionized ammonia and nitrite level below prescribed standards (P < 0.05). This resulted in reduction of stress and immune reactions of cultivated fish (P < 0.05), leading to an augmentation of final weight and survival. Application of the selected microbial complex resulted in a significant improvement of the aquaculture ecosystem.
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Affiliation(s)
- Alireza Neissi
- Department of Fisheries Sciences, Faculty of Natural Resources, University of Tehran, Karaj, 331585-4314, Iran
| | - Gholamreza Rafiee
- Department of Fisheries Sciences, Faculty of Natural Resources, University of Tehran, Karaj, 331585-4314, Iran.
| | - Hamid Farahmand
- Department of Fisheries Sciences, Faculty of Natural Resources, University of Tehran, Karaj, 331585-4314, Iran
| | - Shadi Rahimi
- Division of Systems & Synthetic Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 41296, Gothenburg, Sweden
| | - Ivan Mijakovic
- Division of Systems & Synthetic Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 41296, Gothenburg, Sweden.
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Lyngby, Denmark.
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Silva LCF, Lima HS, Mendes TADO, Sartoratto A, Sousa MP, de Souza RS, de Paula SO, de Oliveira VM, Silva CC. Physicochemical characterization of Pseudomonas stutzeri UFV5 and analysis of its transcriptome under heterotrophic nitrification/aerobic denitrification pathway induction condition. Sci Rep 2020; 10:2215. [PMID: 32042029 PMCID: PMC7010759 DOI: 10.1038/s41598-020-59279-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 01/20/2020] [Indexed: 02/02/2023] Open
Abstract
Biological ammonium removal via heterotrophic nitrification/aerobic denitrification (HN/AD) presents several advantages in relation to conventional removal processes, but little is known about the microorganisms and metabolic pathways involved in this process. In this study, Pseudomonas stutzeri UFV5 was isolated from an activated sludge sample from oil wastewater treatment station and its ammonium removal via HN/AD was investigated by physicochemical and molecular approaches to better understand this process and optimize the biological ammonium removal in wastewater treatment plants. Results showed that P. stutzeri UFV5 removed all the ammonium in 48–72 hours using pyruvate, acetate, citrate or sodium succinate as carbon sources, C/N ratios 6, 8, 10 and 12, 3–6% salinities, pH 7–9 and temperatures of 20–40 °C. Comparative genomics and PCR revealed that genes encoding the enzymes involved in anaerobic denitrification process are present in P. stutzeri genome, but no gene that encodes enzymes involved in autotrophic nitrification was found. Furthermore, transcriptomics showed that none of the known enzymes of autotrophic nitrification and anaerobic denitrification had their expression differentiated and an upregulation of the biosynthesis machinery and protein translation was observed, besides several genes with unknown function, indicating a non-conventional mechanism involved in HN/AD process.
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Affiliation(s)
| | - Helena Santiago Lima
- Department of Microbiology, Federal University of Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil
| | | | - Adilson Sartoratto
- Pluridisciplinary Center for Chemical, Biological and Agricultural Research, Campinas State University, Campinas, São Paulo, 13083-970, Brazil
| | - Maira Paula Sousa
- Petrobras - Research and Development Center (CENPES), Petrobras, Rio de Janeiro, 21941-915, Brazil
| | - Rodrigo Suhett de Souza
- Petrobras - Research and Development Center (CENPES), Petrobras, Rio de Janeiro, 21941-915, Brazil
| | - Sérgio Oliveira de Paula
- Department of General Biology, Federal University of Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil
| | - Valéria Maia de Oliveira
- Pluridisciplinary Center for Chemical, Biological and Agricultural Research, Campinas State University, Campinas, São Paulo, 13083-970, Brazil
| | - Cynthia Canedo Silva
- Department of Microbiology, Federal University of Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil.
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Ren LF, Chen R, Zhang X, Shao J, He Y. Phenol biodegradation and microbial community dynamics in extractive membrane bioreactor (EMBR) for phenol-laden saline wastewater. BIORESOURCE TECHNOLOGY 2017; 244:1121-1128. [PMID: 28869125 DOI: 10.1016/j.biortech.2017.08.121] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 08/14/2017] [Accepted: 08/18/2017] [Indexed: 06/07/2023]
Abstract
An extractive membrane bioreactor (EMBR) for phenol-laden saline wastewater was set up in this study to investigate the variations of phenol removal, extracellular polymeric substance (EPS) release and microbial community dynamics. The gradual release of phenol and the total separation of salt were achieved by silicon rubber tube membrane. Only phenol (55.6-273.9mg/L) was extracted into microorganism unit from wastewaters containing 1.0-5.0g/L phenol and 35.0g/L NaCl. After 82d of EMBR operation, maximal 273.9mg/L of phenol was removed in EMBR. Low concentration of phenol in wastewater (2.5g/L) played a favorable effect on the microbial community structure, community and dynamics. The enumeration of Proteobacteria (30,499 sequences) significantly increased with more released EPS (82.82mg/gSS) to absorb and degrade phenol, compared to the virgin data without phenol addition. However, high concentration of phenol showed adverse effects on EPS release, microbial abundance and biodiversity.
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Affiliation(s)
- Long-Fei Ren
- School of Environmental Science and Engineering, Shanghai Jiaotong University, No. 800 Dongchuan Road, Shanghai 200240, Shanghai, PR China
| | - Rui Chen
- School of Environmental Science and Engineering, Shanghai Jiaotong University, No. 800 Dongchuan Road, Shanghai 200240, Shanghai, PR China
| | - Xiaofan Zhang
- School of Environmental Science and Engineering, Shanghai Jiaotong University, No. 800 Dongchuan Road, Shanghai 200240, Shanghai, PR China
| | - Jiahui Shao
- School of Environmental Science and Engineering, Shanghai Jiaotong University, No. 800 Dongchuan Road, Shanghai 200240, Shanghai, PR China.
| | - Yiliang He
- School of Environmental Science and Engineering, Shanghai Jiaotong University, No. 800 Dongchuan Road, Shanghai 200240, Shanghai, PR China
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Potential for aerobic NO 2- reduction and corresponding key enzyme genes involved in Alcaligenes faecalis strain NR. Arch Microbiol 2017; 200:147-158. [PMID: 28879417 DOI: 10.1007/s00203-017-1428-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 08/27/2017] [Accepted: 08/31/2017] [Indexed: 10/18/2022]
Abstract
The potential for aerobic NO2- removal by Alcaligenes faecalis strain NR was investigated. 35 mg/L of NO2--N was removed by strain NR under aerobic conditions in the presence of NH4+. 15N-labeling experiment demonstrated that N2O and N2 were possible products during the aerobic nitrite removal process by strain NR. The key enzyme genes of nirK, norB and nosZ, which regulate the aerobic nitrite denitrification process, were successfully amplified from strain NR. The gene sequence analysis indicates that copper-containing nitrite reductase (NIRK) and periplasmic nitrous oxide reductase (NOSZ) were both hydrophilic protein and the transmembrane structures were absent, while nitric oxide reductase large subunit (NORB) was a hydrophobic and transmembrane protein. According to the three-dimensional structure and binding site analysis, the bulky and hydrophobic methionine residue proximity to the nitrite binding sites of NIRK was speculated to be related to the oxygen tolerance of NIRK from strain NR.
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Microbial community shift in a suspended stuffing biological reactor with pre-attached aerobic denitrifier. World J Microbiol Biotechnol 2017. [PMID: 28634714 DOI: 10.1007/s11274-017-2288-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Bioaugmentation is substantially determined by pre-attached communities in biological stuffing systems. However, the inevitable changes of microbial community shift occurred between pre-attached microorganisms on stuffing material and other existing communities in wastewater. Targeting at nitrogen removal in aerobic denitrification reactors, biological augmentation was built by polyurethane supporting material and aerobic denitrification bacteria of Pseudomonas stutzeri strains were primarily colonized. The total nitrogen removal reached a high efficiency of 77 ± 6%, resulting from a relative high nitrate removal (90%) and a low nitrite production of 24 mg l-1. The nitrate removal was kept 10% higher using preattached strains than that using wastewater communities. During the bioaugmentation process, abundant bacteria related to nitrogen removal were evolutively enriched to compete with preattached Pseudomonas stutzeri. The most abundant bacteria growing up in the biofilm belonged to various Classes of Proteobacteria Phylum. A noticeable nitrite production with a relative low TN removal efficiency occurred when Brucella sp. and Brevundimonas sp. were simultaneously enriched in place of Pseudomonas, because Brevundimonas also accumulated nitrite during denitrification under an aerobic condition. The results indicated that pre-attached denitrifiers in comprehensive communities on stuffing material can be established for the efficient nitrogen and COD removal in aerobic denitrification reactors.
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Erdirencelebi D, Koyuncu S. Operational strategies and environmental conditions inducing aerobic denitritation in short-cut biological nitrogen removal at side-line treatment. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2017; 52:607-615. [PMID: 28281935 DOI: 10.1080/10934529.2017.1293994] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Factors promoting aerobic denitritation in a pilot-scale short-cut biological nitrogen removal (SBNR) process were investigated. The study implemented optimization of nitrogen removal in the anaerobic reject water (ARW) having a low organic C:N ratio ARW was produced in a large-scale municipal wastewater treatment plant (WWTP). Aerobic denitritation occurred consistently during study of a specific period of sequential batch reactor (SBR) where nitrite removal under fully aerobic conditions was obtained with a switch from oxygen to nitrite respiration, creating an aerobic (high oxidation-reduction potential) condition. Specific factors inducing aerobic denitritation were found related to several parameters as ammonium concentration, temperature, feeding mode, duration of the oxic stage and substrate availability due to beta-oxidation of lipid matter. Microbial analyses indicated a higher increase in nitrite reducing than ammonium oxidizing activity, as an evidence for nitrifying denitrifier bacterial dominance in the biomass. The reaction induced a reduction in the inhibitory products of the process as volatile fatty acids (VFAs) and free nitrous oxide (FNA), produced bicarbonate and increased removal efficiency of ammonium and nitrite, thus, total nitrogen. The outcome presents potential ways for further saving on aeration and chemical need via operational means, while taking advantage of the slowly degrading organic matter on SBNR performance.
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Affiliation(s)
- Dilek Erdirencelebi
- a Environmental Engineering Department , Engineering Faculty, Selcuk University , Konya , Turkey
| | - Serdar Koyuncu
- b Konya Water and Sewerage Administration , Konya , Turkey
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12
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Du C, Cui CW, Qiu S, Shi SN, Li A, Ma F. Nitrogen removal and microbial community shift in an aerobic denitrification reactor bioaugmented with a Pseudomonas strain for coal-based ethylene glycol industry wastewater treatment. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:11435-11445. [PMID: 28316045 DOI: 10.1007/s11356-017-8824-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 03/13/2017] [Indexed: 06/06/2023]
Abstract
An aerobic denitrification system, initially bioaugmented with Pseudomonas strain T13, was established to treat coal-based ethylene glycol industry wastewater, which contained 3219 ± 86 mg/L total nitrogen (TN) and 1978 ± 14 mg/L NO3--N. In the current study, a stable denitrification efficiency of 53.7 ± 4.7% and nitrite removal efficiency of 40.1 ± 2.7% were achieved at different diluted influent concentrations. Toxicity evaluation showed that a lower toxicity of effluent was achieved when industry wastewater was treated by stuffing biofilm communities compared to suspended communities. Relatively high TN removal (~50%) and chemical oxygen demand removal percentages (>65%) were obtained when the influent concentration was controlled at below 50% of the raw industry wastewater. However, a further increased concentration led to a 20-30% decrease in nitrate and nitrite removal. Microbial network evaluation showed that a reduction in Pseudomonas abundance was induced during the succession of the microbial community. The napA gene analysis indicated that the decrease in nitrate and nitrite removal happened when abundance of Pseudomonas was reduced to less than 10% of the overall stuffing biofilm communities. Meanwhile, other denitrifying bacteria, such as Paracoccus, Brevundimonas, and Brucella, were subsequently enriched through symbiosis in the whole microbial network.
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Affiliation(s)
- Cong Du
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), Harbin, 150090, China
| | - Chong-Wei Cui
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), Harbin, 150090, China.
| | - Shan Qiu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), Harbin, 150090, China
| | - Sheng-Nan Shi
- School of Life Science, Liaoning Normal University, Dalian, 116029, China
| | - Ang Li
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), Harbin, 150090, China
| | - Fang Ma
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), Harbin, 150090, China.
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13
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Impacts of chemical gradients on microbial community structure. ISME JOURNAL 2017; 11:920-931. [PMID: 28094795 PMCID: PMC5363838 DOI: 10.1038/ismej.2016.175] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Revised: 10/25/2016] [Accepted: 11/08/2016] [Indexed: 12/05/2022]
Abstract
Succession of redox processes is sometimes assumed to define a basic microbial community structure for ecosystems with oxygen gradients. In this paradigm, aerobic respiration, denitrification, fermentation and sulfate reduction proceed in a thermodynamically determined order, known as the ‘redox tower'. Here, we investigated whether redox sorting of microbial processes explains microbial community structure at low-oxygen concentrations. We subjected a diverse microbial community sampled from a coastal marine sediment to 100 days of tidal cycling in a laboratory chemostat. Oxygen gradients (both in space and time) led to the assembly of a microbial community dominated by populations that each performed aerobic and anaerobic metabolism in parallel. This was shown by metagenomics, transcriptomics, proteomics and stable isotope incubations. Effective oxygen consumption combined with the formation of microaggregates sustained the activity of oxygen-sensitive anaerobic enzymes, leading to braiding of unsorted redox processes, within and between populations. Analyses of available metagenomic data sets indicated that the same ecological strategies might also be successful in some natural ecosystems.
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Zhou S, Huang T, Ngo HH, Zhang H, Liu F, Zeng M, Shi J, Qiu X. Nitrogen removal characteristics of indigenous aerobic denitrifiers and changes in the microbial community of a reservoir enclosure system via in situ oxygen enhancement using water lifting and aeration technology. BIORESOURCE TECHNOLOGY 2016; 214:63-73. [PMID: 27128190 DOI: 10.1016/j.biortech.2016.04.071] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Revised: 04/13/2016] [Accepted: 04/15/2016] [Indexed: 06/05/2023]
Abstract
Indigenous aerobic denitrifiers of a reservoir system were enhanced in situ by water lifting and aeration technology. Nitrogen removal characteristics and changes in the bacterial community were investigated. Results from a 30-day experiment showed that the TN in the enhanced water system decreased from 1.08-2.02 to 0.75-0.91mg/L and that TN removal rates varied between 21.74% and 52.54% without nitrite accumulation, and TN removal rate of surface sediments reached 41.37±1.55%. The densities of aerobic denitrifiers in the enhanced system increased. Furthermore, the enhanced system showed a clear inhibition of Fe, Mn, and P performances. Community analysis using Miseq showed that diversity was higher in the in situ oxygen enhanced system than in the control system. In addition, the microbial composition was significantly different between systems. It can be concluded that in situ enhancement of indigenous aerobic denitrifiers is very effective in removing nitrogen from water reservoir systems.
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Affiliation(s)
- Shilei Zhou
- Key Lab of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Tinglin Huang
- Key Lab of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, China.
| | - Huu Hao Ngo
- School of Civil and Environmental Engineering, Faculty of Engineering and Information Technology, University of Technology Sydney, NSW 2007, Australia
| | - Haihan Zhang
- Key Lab of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Fei Liu
- Key Lab of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Mingzheng Zeng
- Key Lab of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Jianchao Shi
- Key Lab of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Xiaopeng Qiu
- Key Lab of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, China
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15
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Wang T, Dang Q, Liu C, Yan J, Fan B, Cha D, Yin Y, Zhang Y. Heterotrophic nitrogen removal by a newly-isolated alkalitolerant microorganism, Serratia marcescens W5. BIORESOURCE TECHNOLOGY 2016; 211:618-627. [PMID: 27043057 DOI: 10.1016/j.biortech.2016.03.142] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 03/25/2016] [Accepted: 03/26/2016] [Indexed: 06/05/2023]
Abstract
A new microbe, Serratia marcescens W5 was successfully isolated. Its feasibility in purification of excessively nitrogen-containing wastewater was evaluated using inorganic nitrogen media. Single factor tests showed that W5 exhibited high ammonium removal rates (above 80%) under different culture conditions (pH 7-10, C/N ratios of 6-20, 15-35°C, 0-2.5% of salinity, respectively). Besides various organic carbon sources, W5 was able to utilize calcium carbonate with 28.05% of ammonium removed. Further experiments indicated that W5 was capable of resisting high-strength ammonium (1200mg/L) with the maximum removal rate of 514.13mgL(-1)d(-1). The nitrogen removal pathway of W5 was also tested, showing that both nitrite and nitrate were efficiently removed only in the presence of ammonium, with hydroxylamine as intermediate, which was different from the conventional nitrogen removal pathway. All the results verified that W5 was a good candidate for the purification of excessively nitrogenous wastewater.
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Affiliation(s)
- Teng Wang
- College of Marine Life Science, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China
| | - Qifeng Dang
- College of Marine Life Science, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China
| | - Chengsheng Liu
- College of Marine Life Science, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China.
| | - Jingquan Yan
- School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China
| | - Bing Fan
- Qingdao Aorun Biotechnology Co. Ltd., Room 602, Century Mansion, 39 Donghaixi Road, Qingdao 266071, PR China
| | - Dongsu Cha
- The Graduate School of Biotechnology, Korea University, Seoul 136-701, South Korea
| | - Yanyan Yin
- College of Marine Life Science, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China
| | - Yubei Zhang
- College of Marine Life Science, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China
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16
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Xue D, Yang M, Wang ZL. Assessing the Effects of Acidification on N Dynamics in Jiyun River System of Tianjin, China. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2015; 95:822-829. [PMID: 26499323 DOI: 10.1007/s00128-015-1681-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 10/17/2015] [Indexed: 06/05/2023]
Abstract
Alterations in pH have significant effects on nitrification and denitrification processes in aquatic systems. The Jiyun River in northern China experiences significant acid precipitation, and as such was selected to investigate the effects of decreasing pH (river pH at 8.2, pH at 6 and 5) on N dynamics via incubation experiments (35 and 10°C). Statistical results indicated that the NO3 (-) concentrations of the control (pH at 8.2) were either significantly lower (at 35°C) or significantly higher (at 10°C) than the treatments of pH at 6 and 5 at the alpha level of 0.05 in the incubation. However, the NO3 (-) concentrations of the two pH treatments showed significant difference during part of the reaction stage at 35°C and no difference at 10°C. Analysis indicated that nitrification and coupled nitrification-aerobic denitrification occurred for all treatments, which resulted in NO3 (-) being either accumulated or removed at the end of the incubation.
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Affiliation(s)
- Dongmei Xue
- Tianjin Key Laboratory of Water Resources and Environment, Tianjin Normal University, Tianjin, 300387, China
| | - Mengfan Yang
- Tianjin Key Laboratory of Water Resources and Environment, Tianjin Normal University, Tianjin, 300387, China
- Urban and Environmental Science College, Tianjin Normal University, Tianjin, 300387, China
| | - Zhong-Liang Wang
- Tianjin Key Laboratory of Water Resources and Environment, Tianjin Normal University, Tianjin, 300387, China.
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550002, China.
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17
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18
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Babatsouli P, Fodelianakis S, Paranychianakis N, Venieri D, Dialynas M, Kalogerakis N. Single stage treatment of saline wastewater with marine bacterial-microalgae consortia in a fixed-bed photobioreactor. JOURNAL OF HAZARDOUS MATERIALS 2015; 292:155-163. [PMID: 25804790 DOI: 10.1016/j.jhazmat.2015.02.060] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 02/20/2015] [Accepted: 02/21/2015] [Indexed: 06/04/2023]
Abstract
Currently, the treatment of aquaculture-origin effluents is mainly performed through land-based recirculating aquaculture systems (RAS). In this study, we evaluate and introduce a novel immobilized/packed bed bioreactor which uses a synthetic textile as the support medium. A marine microbial consortium was developed on the textile by its inoculation with the microalgae Picochlorum sp. The bioreactor was tested with variable loadings of C and N and showed outstanding performance approaching removal rates up to 95% within a few hours (4-5h) of operation. Pyrosequencing analysis revealed a novel microbial consortium consisting mainly of chitrinomycetes, Pseudomonas sp. and the absence of β-proteobacteria, which is the Class encompassing autotrophic nitrifiers. Quantitative polymerase chain reaction further confirmed these findings suggesting heterotrophic nitrification and aerobic denitrification as the principal mechanisms of N-removal from the bioreactor. Overall our findings reveal the potential of the AdvanTex System for the treatment of marine aquaculture effluents-COD reduction and N-removal, in a single stage.
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Affiliation(s)
- P Babatsouli
- School of Environmental Engineering, Technical University of Crete, Chania, Greece
| | - S Fodelianakis
- School of Environmental Engineering, Technical University of Crete, Chania, Greece
| | - N Paranychianakis
- School of Environmental Engineering, Technical University of Crete, Chania, Greece
| | - D Venieri
- School of Environmental Engineering, Technical University of Crete, Chania, Greece
| | - M Dialynas
- DIALYNAS S.A., El. Venizelou 15, Chania, Greece
| | - N Kalogerakis
- School of Environmental Engineering, Technical University of Crete, Chania, Greece.
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19
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Yang M, Xue D, Meng F, Wang ZL. The effects of salinity on coupled nitrification and aerobic denitrification in an estuarine system. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2015; 71:1718-1726. [PMID: 26038938 DOI: 10.2166/wst.2015.159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Salinity has significant effects on nitrification and denitrification processes, particularly in estuarine systems. A dissolved oxygen-enriched river and its estuary in northern China were selected to investigate the impact of salinity gradients (0.6, 4, 7.6, 11.4 and 14.7‰) obtained from the mixing of river samples and estuarine samples with different proportions on coupled nitrification and aerobic denitrification via incubation experiments (35 and 10 °C). Results indicated that: (a) nitrification and coupled nitrification-aerobic denitrification occurred for all treatments, which resulted in NO3- being either accumulated or removed at the end of the incubation; (b) a suitable range of salinity is 4.0-11.4‰ for nitrification and 4.0-7.6‰ for coupled nitrification-aerobic denitrification; and (c) the relatively higher temperature (35 °C) can effectively stimulate N transformation processes compared to the lover temperature (10 °C) in the incubation experiment.
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Affiliation(s)
- Mengfan Yang
- Tianjin Key Laboratory of Water Resources and Environment, Tianjin Normal University, Tianjin 300387, China E-mail: ; Urban and Environmental Science College, Tianjin Normal University, Tianjin 300387, China
| | - Dongmei Xue
- Tianjin Key Laboratory of Water Resources and Environment, Tianjin Normal University, Tianjin 300387, China E-mail:
| | - Fanqiao Meng
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Zhong-Liang Wang
- Tianjin Key Laboratory of Water Resources and Environment, Tianjin Normal University, Tianjin 300387, China E-mail: ; State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China
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20
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Cydzik-Kwiatkowska A, Rusanowska P, Zielińska M, Bernat K, Wojnowska-Baryła I. Structure of nitrogen-converting communities induced by hydraulic retention time and COD/N ratio in constantly aerated granular sludge reactors treating digester supernatant. BIORESOURCE TECHNOLOGY 2014; 154:162-70. [PMID: 24384323 DOI: 10.1016/j.biortech.2013.11.099] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 11/25/2013] [Accepted: 11/30/2013] [Indexed: 05/27/2023]
Abstract
This study investigated how hydraulic retention time (HRT) and COD/N ratio affect nitrogen-converting consortia in constantly aerated granules treating high-ammonium digester supernatant. Three HRTs (10, 13, 19 h) were tested at COD/N ratios of 4.5 and 2.3. Denaturing gradient gel electrophoresis and relative real-time PCR were used to characterize the microbial communities. When changes in HRT and COD/N increased nitrogen loading, the ratio of the relative abundance of aerobic to anaerobic ammonium-oxidizers decreased. The COD/N ratio determined the species composition of the denitrifiers; however, Thiobacillus denitrificans, Pseudomonas denitrificans and Azoarcus sp. showed a high tolerance to the environmental conditions and occurred in the granules from all reactors. Denitrifier genera that support granule formation were identified, such as Pseudomonas, Shinella, and Flavobacterium. In aerated granules, nirK-possessing bacteria were more diverse than nirS-possessing bacteria. At a low COD/N ratio, N2O-reducer diversity increased because of the presence of bacteria known as aerobic denitrifiers.
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Affiliation(s)
- Agnieszka Cydzik-Kwiatkowska
- Department of Environmental Biotechnology, University of Warmia and Mazury in Olsztyn, Słoneczna 45 G, 10-709 Olsztyn, Poland.
| | - Paulina Rusanowska
- Department of Environmental Biotechnology, University of Warmia and Mazury in Olsztyn, Słoneczna 45 G, 10-709 Olsztyn, Poland
| | - Magdalena Zielińska
- Department of Environmental Biotechnology, University of Warmia and Mazury in Olsztyn, Słoneczna 45 G, 10-709 Olsztyn, Poland
| | - Katarzyna Bernat
- Department of Environmental Biotechnology, University of Warmia and Mazury in Olsztyn, Słoneczna 45 G, 10-709 Olsztyn, Poland
| | - Irena Wojnowska-Baryła
- Department of Environmental Biotechnology, University of Warmia and Mazury in Olsztyn, Słoneczna 45 G, 10-709 Olsztyn, Poland
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21
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Liu J, Sun F, Wang L, Ju X, Wu W, Chen Y. Molecular characterization of a microbial consortium involved in methane oxidation coupled to denitrification under micro-aerobic conditions. Microb Biotechnol 2013; 7:64-76. [PMID: 24245852 PMCID: PMC3896940 DOI: 10.1111/1751-7915.12097] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 10/07/2013] [Indexed: 11/29/2022] Open
Abstract
Methane can be used as an alternative carbon source in biological denitrification because it is nontoxic, widely available and relatively inexpensive. A microbial consortium involved in methane oxidation coupled to denitrification (MOD) was enriched with nitrite and nitrate as electron acceptors under micro-aerobic conditions. The 16S rRNA gene combined with pmoA phylogeny of methanotrophs and nirK phylogeny of denitrifiers were analysed to reveal the dominant microbial populations and functional microorganisms. Real-time quantitative polymerase chain reaction results showed high numbers of methanotrophs and denitrifiers in the enriched consortium. The 16S rRNA gene clone library revealed that Methylococcaceae and Methylophilaceae were the dominant populations in the MOD ecosystem. Phylogenetic analyses of pmoA gene clone libraries indicated that all methanotrophs belonged to Methylococcaceae, a type I methanotroph employing the ribulose monophosphate pathway for methane oxidation. Methylotrophic denitrifiers of the Methylophilaceae that can utilize organic intermediates (i.e. formaldehyde, citrate and acetate) released from the methanotrophs played a vital role in aerobic denitrification. This study is the first report to confirm micro-aerobic denitrification and to make phylogenetic and functional assignments for some members of the microbial assemblages involved in MOD.
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Affiliation(s)
- Jingjing Liu
- Institute of Environmental Science and Technology, Zhejiang University, Yuhangtang Road 866#, Hangzhou, 310058, China; Department of Architecture and Resources Engineering, Jiangxi University of Science and Technology Nanchang Compus, Shuanggang East Road 1180#, Nanchang, 310013, China
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22
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Saggar S, Jha N, Deslippe J, Bolan NS, Luo J, Giltrap DL, Kim DG, Zaman M, Tillman RW. Denitrification and N2O:N2 production in temperate grasslands: processes, measurements, modelling and mitigating negative impacts. THE SCIENCE OF THE TOTAL ENVIRONMENT 2013; 465:173-95. [PMID: 23260378 DOI: 10.1016/j.scitotenv.2012.11.050] [Citation(s) in RCA: 156] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 11/11/2012] [Accepted: 11/12/2012] [Indexed: 05/02/2023]
Abstract
In this review we explore the biotic transformations of nitrogenous compounds that occur during denitrification, and the factors that influence denitrifier populations and enzyme activities, and hence, affect the production of nitrous oxide (N2O) and dinitrogen (N2) in soils. Characteristics of the genes related to denitrification are also presented. Denitrification is discussed with particular emphasis on nitrogen (N) inputs and dynamics within grasslands, and their impacts on the key soil variables and processes regulating denitrification and related gaseous N2O and N2 emissions. Factors affecting denitrification include soil N, carbon (C), pH, temperature, oxygen supply and water content. We understand that the N2O:N2 production ratio responds to the changes in these factors. Increased soil N supply, decreased soil pH, C availability and water content generally increase N2O:N2 ratio. The review also covers approaches to identify and quantify denitrification, including acetylene inhibition, (15)N tracer and direct N2 quantification techniques. We also outline the importance of emerging molecular techniques to assess gene diversity and reveal enzymes that consume N2O during denitrification and the factors affecting their activities and consider a process-based approach that can be used to quantify the N2O:N2 product ratio and N2O emissions with known levels of uncertainty in soils. Finally, we explore strategies to reduce the N2O:N2 product ratio during denitrification to mitigate N2O emissions. Future research needs to focus on evaluating the N2O-reducing ability of the denitrifiers to accelerate the conversion of N2O to N2 and the reduction of N2O:N2 ratio during denitrification.
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Affiliation(s)
- Surinder Saggar
- Ecosystems & Global Change Team, Landcare Research, Private Bag 11052, Palmerston North 4442, New Zealand.
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23
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Zhao Y, Huang J, Zhao H, Yang H. Microbial community and N removal of aerobic granular sludge at high COD and N loading rates. BIORESOURCE TECHNOLOGY 2013; 143:439-46. [PMID: 23827440 DOI: 10.1016/j.biortech.2013.06.020] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 06/04/2013] [Accepted: 06/08/2013] [Indexed: 05/27/2023]
Abstract
An aerobic granular sludge, cultivated with modified piggery wastewater, was capable of simultaneously removing COD and N at high COD and N loading rates. Confirmed to be identical with the DGGE band B9, isolate Thauera strain TN9 was the most dominant microorganism in the granular sludge. NirS and NosZ gene were amplified and sequenced from strain TN9 suggested it is crucial to N removal. Some other dominant DGGE bands belonged to Zoogloea and TM7, might play important roles in the formation and the stabilization of the granules. Meanwhile, no AOA amoA or anammox bacterium hzo gene was detected in the granules. All amoA clone libraries of AOB were clustered to Nitrosomonas. Yet those AOB were not present in DGGE dominant bands. Therefore, the heterotrophic nitrification and autotrophic nitrification coexist in the granules, the heterotrophic nitrification might contribute more to the N removal at high COD and N loading rates.
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Affiliation(s)
- Yonggui Zhao
- Key Laboratory of Environmental and Applied Microbiology, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
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24
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Hu Z, Zhang J, Li S, Xie H. Impact of carbon source on nitrous oxide emission from anoxic/oxic biological nitrogen removal process and identification of its emission sources. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2013; 20:1059-1069. [PMID: 22684879 DOI: 10.1007/s11356-012-1018-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 05/28/2012] [Indexed: 06/01/2023]
Abstract
Wastewater treatment is an important source of nitrous oxide (N(2)O), which is a strong greenhouse gas and dominate ozone-depleting substance. The purpose of this study was to evaluate the effect of carbon source on N(2)O emission from anoxic/oxic biological nitrogen removal process. The mechanisms of N(2)O emission were also studied. Long-term experiments were operated to evaluate the effect of three different carbon sources (i.e., glucose, sodium acetate, and soluble starch) on N(2)O emission characteristics. And batch experiments, in the presence or absence of specific inhibitors, were carried out to identify the sources of N(2)O emission. The ammonia-oxidizing bacteria (AOB) and denitrifiers community compositions under different circumstances were also analyzed based on which the underlying mechanisms of N(2)O emission were elucidated. The conversion ratios of N(2)O in reactors with glucose, sodium acetate, and soluble starch were 5.3 %, 8.8 %, and 2.8 %, respectively. The primary process responsible for N(2)O emission was nitrifier denitrification by Nitrosomonas-like AOB, while denitrification by heterotrophic denitrifiers acted as the sink. Reactor with sodium acetate showed the highest N(2)O emission, together with the highest nitrogen and phosphate removal ratios. Carbon source has a significant impact on N(2)O emission quantity and relatively minor effect on its production mechanism.
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Affiliation(s)
- Zhen Hu
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 27 Shanda Nanlu, Jinan, 250100 Shandong, People's Republic of China
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25
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Velusamy K, Krishnani KK. Heterotrophic Nitrifying and Oxygen Tolerant Denitrifying Bacteria from Greenwater System of Coastal Aquaculture. Appl Biochem Biotechnol 2013; 169:1978-92. [DOI: 10.1007/s12010-013-0109-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 01/14/2013] [Indexed: 10/27/2022]
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26
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Chen J, Strous M. Denitrification and aerobic respiration, hybrid electron transport chains and co-evolution. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1827:136-44. [PMID: 23044391 DOI: 10.1016/j.bbabio.2012.10.002] [Citation(s) in RCA: 250] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 09/26/2012] [Accepted: 10/01/2012] [Indexed: 11/18/2022]
Abstract
This paper explores the bioenergetics and potential co-evolution of denitrification and aerobic respiration. The advantages and disadvantages of combining these two pathways in a single, hybrid respiratory chain are discussed and the experimental evidence for the co-respiration of nitrate and oxygen is critically reviewed. A scenario for the co-evolution of the two pathways is presented. This article is part of a Special Issue entitled: The evolutionary aspects of bioenergetic systems.
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Affiliation(s)
- Jianwei Chen
- Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, D-28359 Bremen, Germany
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27
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Zhang C, Wang L, Yan N, Zhang Y, Liu R. Air-lift internal loop biofilm reactor for realized simultaneous nitrification and denitrification. Bioprocess Biosyst Eng 2012; 36:597-602. [DOI: 10.1007/s00449-012-0814-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Accepted: 08/15/2012] [Indexed: 10/27/2022]
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Zhao B, An Q, He YL, Guo JS. N2O and N2 production during heterotrophic nitrification by Alcaligenes faecalis strain NR. BIORESOURCE TECHNOLOGY 2012; 116:379-385. [PMID: 22534373 DOI: 10.1016/j.biortech.2012.03.113] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Revised: 03/28/2012] [Accepted: 03/29/2012] [Indexed: 05/27/2023]
Abstract
A heterotrophic nitrifier, strain NR, was isolated from a membrane bioreactor. Strain NR was identified as Alcaligenes faecalis by Auto-Microbic system and 16S rRNA gene sequence analysis. A. faecalis strain NR shows a capability of heterotrophic nitrification and N(2)O and N(2) production as well under the aerobic condition. Further tests demonstrated that neither nitrite nor nitrate could be denitrified aerobically by strain NR. However, when hydroxylamine was used as the sole nitrogen source, nitrogenous gases were detected. With an enzyme assay, a 0.063 U activity of hydroxylamine oxidase was observed, while nitrate reductase and nitrite reductase were undetectable. Thus, nitrogenous gas was speculated to be produced via hydroxylamine. Therefore, two different metabolic pathways might exist in A. faecalis NR. One is heterotrophic nitrification by oxidizing ammonium to nitrite and nitrate. The other is oxidizing ammonium to nitrogenous gas directly via hydroxylamine.
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Affiliation(s)
- Bin Zhao
- The Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Chongqing University, Chongqing 400045, PR China.
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29
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Kraft B, Strous M, Tegetmeyer HE. Microbial nitrate respiration – Genes, enzymes and environmental distribution. J Biotechnol 2011; 155:104-17. [DOI: 10.1016/j.jbiotec.2010.12.025] [Citation(s) in RCA: 223] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Revised: 12/07/2010] [Accepted: 12/20/2010] [Indexed: 01/13/2023]
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30
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Dalsgaard T, Revsbech NP. Regulating factors of denitrification in trickling filter biofilms as measured with the oxygen/nitrous oxide microsensor. FEMS Microbiol Ecol 2011. [DOI: 10.1111/j.1574-6941.1992.tb01651.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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31
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Kim JH, Ha CY, Oa SW, Lee JW, Park SH, Kwon SY, Kim S, Kim Y. Assessing the activity and diversity of fumarate-fed denitrifying bacteria by performing field single-well push-pull tests. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2011; 46:33-41. [PMID: 21104493 DOI: 10.1080/10934529.2011.526080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In situ biological denitrification has been proposed as an important metabolic activity in the remediation of nitrate-contaminated groundwater. In this study, the effects of fumarate, an electron donor for biological denitrification, on the in situ denitrifying activity were determined by using three types of single-well push-pull tests; transport, biostimulation and activity tests. During the tests, changes in microbial community composition were also investigated using denaturing gradient gel electrophoresis (DGGE) of 16S rRNA genes. Transport test demonstrated that non-reactive tracer and biologically reactive solutes behaved similarly. A biostimulation test was conducted to stimulate the denitrifying activities of native microorganisms, which were monitored by detecting the simultaneous production of CO(2) and drastic degradations of both nitrate and fumarate after the injection of fumarate as an electron donor and/or carbon source, with nitrate as an electron acceptor. A phylogenetic analysis suggested that the taxonomic affiliation of the dominant species before biostimulation was γ-Proteobacteria, including Acinetobacter species and Pseudomonas fluorescens, while the dominant species after biostimulation were affiliated with β-Proteobacteria, cytophaga-Flavobacterium-Bacteroides and high G+C gram-positive bacteria. These results suggest that the analyses of groundwater samples using a combination of single well push pull tests with DGGE can be applied to investigate the activity, diversity and composition shift of denitrifying bacteria in a nitrate-contaminated aquifer.
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Affiliation(s)
- Jin-Hoon Kim
- Sudo Kwong Landfill Site Management Co., Incheon, Korea
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32
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Xiao J, Zhu C, Sun D, Guo P, Tian Y. Removal of ammonium-N from ammonium-rich sewage using an immobilized Bacillus subtilis AYC bioreactor system. J Environ Sci (China) 2011; 23:1279-1285. [PMID: 22128534 DOI: 10.1016/s1001-0742(10)60542-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A self-design bioreactor system employing a fixed bed operation process with immobilized Bacillus subtilis AYC beads for NH4+-N removal from slightly polluted water was proposed. Polyvinyl alcohol and Na-alginate were used as a gel matrix to entrap Bacillus subtilis AYC to form the immobilized beads. The NH4+-N removal process was studied in a intermittent operation mode to examine the start-up and steady state behaviors of the immobilized AYC in the reactor. The results indicated that the reactor was in the start-up state during the first week. NH4+-N began to be steadily removal since the second week, and the nitrogen removal rate was between 84.61% and 96.19% when the hydraulic retention time (HRT) was 30 min. To apply Bacillus subtilis AYC to develop a practical nitrogen removal system and further understand its nitrogen removal ability, the bioreactor was continuously operated under different experimental perameters. The results showed that under the optimum conditions of an HRT of 20 min and DO of 3.77-5.80 mg/L, the NH4+-N removal rate reached 99.55%. The NH4+-N removal rate increased as the C/N ratio increased. However, a high C/N may cause a high residual carbon level in the effluent, therefore, the most suitable C/N ratio was 10. In addition, the results showed that the bioreactor system could remove many types of nitrogen such as NH4+-N, NO3--N and organic-N, and had a good performance for inorganic nitrogen removal from sewage.
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Affiliation(s)
- Jingjing Xiao
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy ofAgricultural Sciences, Beijing 100081, China.
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33
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Lam P, Kuypers MMM. Microbial nitrogen cycling processes in oxygen minimum zones. ANNUAL REVIEW OF MARINE SCIENCE 2011; 3:317-45. [PMID: 21329208 DOI: 10.1146/annurev-marine-120709-142814] [Citation(s) in RCA: 253] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Oxygen minimum zones (OMZs) harbor unique microbial communities that rely on alternative electron acceptors for respiration. Conditions therein enable an almost complete nitrogen (N) cycle and substantial N-loss. N-loss in OMZs is attributable to anammox and heterotrophic denitrification, whereas nitrate reduction to nitrite along with dissimilatory nitrate reduction to ammonium are major remineralization pathways. Despite virtually anoxic conditions, nitrification also occurs in OMZs, converting remineralized ammonium to N-oxides. The concurrence of all these processes provides a direct channel from organic N to the ultimate N-loss, whereas most individual processes are likely controlled by organic matter. Many microorganisms inhabiting the OMZs are capable of multiple functions in the N- and other elemental cycles. Their versatile metabolic potentials versus actual activities present a challenge to ecophysiological and biogeochemical measurements. These challenges need to be tackled before we can realistically predict how N-cycling in OMZs, and thus oceanic N-balance, will respond to future global perturbations.
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Affiliation(s)
- Phyllis Lam
- Nutrient Group, Max Planck Institute for Marine Microbiology, D-28359 Bremen, Germany.
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34
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Bhunia P, Yan S, LeBlanc RJ, Tyagi RD, Surampalli RY, Zhang TC. Insight into Nitrous Oxide Emissions from Biological Wastewater Treatment and Biosolids Disposal. ACTA ACUST UNITED AC 2010. [DOI: 10.1061/(asce)hz.1944-8376.0000029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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35
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Dissimilatory reduction of nitrate in seawater by a Methylophaga strain containing two highly divergent narG sequences. ISME JOURNAL 2010; 4:1302-13. [DOI: 10.1038/ismej.2010.47] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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36
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Physiological and molecular biological characteristics of heterotrophic ammonia oxidation by Bacillus sp. LY. World J Microbiol Biotechnol 2010. [DOI: 10.1007/s11274-010-0336-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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37
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Pei Y, Wang J, Wang Z, Yang Z. Characteristics of Ammonia-oxidizing and Denitrifying Bacteria at the River-sediment Interface. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/j.proenv.2010.10.214] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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38
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Quinoline biodegradation and its nitrogen transformation pathway by a Pseudomonas sp. strain. Biodegradation 2009; 21:335-44. [DOI: 10.1007/s10532-009-9304-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2009] [Accepted: 10/13/2009] [Indexed: 10/20/2022]
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39
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Kampschreur MJ, Temmink H, Kleerebezem R, Jetten MSM, van Loosdrecht MCM. Nitrous oxide emission during wastewater treatment. WATER RESEARCH 2009; 43:4093-4103. [PMID: 19666183 DOI: 10.1016/j.watres.2009.03.001] [Citation(s) in RCA: 645] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Revised: 12/24/2008] [Accepted: 03/02/2009] [Indexed: 05/27/2023]
Abstract
Nitrous oxide (N(2)O), a potent greenhouse gas, can be emitted during wastewater treatment, significantly contributing to the greenhouse gas footprint. Measurements at lab-scale and full-scale wastewater treatment plants (WWTPs) have demonstrated that N(2)O can be emitted in substantial amounts during nitrogen removal in WWTPs, however, a large variation in reported emission values exists. Analysis of literature data enabled the identification of the most important operational parameters leading to N(2)O emission in WWTPs: (i) low dissolved oxygen concentration in the nitrification and denitrification stages, (ii) increased nitrite concentrations in both nitrification and denitrification stages, and (iii) low COD/N ratio in the denitrification stage. From the literature it remains unclear whether nitrifying or denitrifying microorganisms are the main source of N(2)O emissions. Operational strategies to prevent N(2)O emission from WWTPs are discussed and areas in which further research is urgently required are identified.
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Affiliation(s)
- Marlies J Kampschreur
- Delft University of Technology, Department of Biotechnology, Julianalaan 67, 2628 BC, Delft, Netherlands.
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40
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Fu S, Fan H, Liu S, Liu Y, Liu Z. A bioaugmentation failure caused by phage infection and weak biofilm formation ability. J Environ Sci (China) 2009; 21:1153-1161. [PMID: 19862932 DOI: 10.1016/s1001-0742(08)62396-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Two biological aerated filters (BAF) were setup for ammonia removal treatment of the circulation water in a marine aquaculture. One of the BAFs was bioaugmented with a heterotrophic nitrifying bacterium, Lutimonas sp. H10, where the ammonia removal was not improved and the massive inoculation was even followed by a nitrification breakdown from day 9 to 18. The nitrification was remained stable in control BAF operated under the same conditions. Fluorescent in situ hybridization (FISH) with rRNA-targeted probes and cultivable method revealed that Lutimonas sp. H10 almost disappeared from the bioaugomented BAF within 3 d, and this was mainly due to the infection of a specific phage as revealed by flask experiment, plaque assay and transmission electron observation. Analyses of 16S rRNA gene libraries showed that bacterial groups from two reactors evolved differently and an overgrowth of protozoa was observed in the bioaugmented BAF. Therefore, phage infection and poor biofilm forming ability of the inoculated strain are the main reasons for bioaugmentation failure. In addition, grazing by protozoa of the bacteria might be the reason for the nitrification breakdown in bioaugmented BAF during day 9-18.
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Affiliation(s)
- Songzhe Fu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
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41
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Taylor SM, He Y, Zhao B, Huang J. Heterotrophic ammonium removal characteristics of an aerobic heterotrophic nitrifying-denitrifying bacterium, Providencia rettgeri YL. J Environ Sci (China) 2009; 21:1336-1341. [PMID: 19999986 DOI: 10.1016/s1001-0742(08)62423-7] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Bacterium Providencia rettgeri YL was found to exhibit an unusual ability to heterotrophically nitrify and aerobically denitrify various concentrations of ammonium (NH4+-N). In order to further understand its removal ability, several experiments were conducted to identify the growth and ammonium removal response at different carbon to nitrogen (C/N) mass ratios, shaking speeds, temperatures, ammonium concentrations and to qualitatively verify the production of nitrogen gas using gas chromatography techniques. Results showed that under optimum conditions (C/N 10, 30 degrees C, 120 r/min), YL can significantly remove low and high concentrations of ammonium within 12 to 48 h of growth, respectively. The nitrification products hydroxylamine (NH2OH), nitrite (NO2(-)) and nitrate (NO3(-)) as well as the denitrification product, nitrogen gas (N2), were detected under completely aerobic conditions.
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Affiliation(s)
- Shauna M Taylor
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
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42
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Morley N, Baggs EM, Dörsch P, Bakken L. Production of NO, N2O and N2 by extracted soil bacteria, regulation by NO2(-) and O2 concentrations. FEMS Microbiol Ecol 2008; 65:102-12. [PMID: 18462397 DOI: 10.1111/j.1574-6941.2008.00495.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
The oxygen control of denitrification and its emission of NO/N2O/N2 was investigated by incubation of Nycodenz-extracted soil bacteria in an incubation robot which monitors O2, NO, N2O and N2 concentrations (in He+O2 atmosphere). Two consecutive incubations were undertaken to determine (1) the regulation of denitrification by O2 and NO2(-) during respiratory O2 depletion and (2) the effects of re-exposure to O2 of cultures with fully expressed denitrification proteome. Early denitrification was only detected (as NO and N2O) at <or=80 microM O2 in treatments with NO2(-), and the rates were three orders of magnitude lower than the rates observed after oxygen depletion (with N2 as the primary product). When re-exposed to O2, the cultures continued to denitrify (8-55% of the rates during the foregoing anoxic phase), but its main product was N2O. The N2O reductase activity recovered as oxygen was being depleted. The results suggest that expression of the denitrifying proteome may result in significant subsequent aerobic denitrification, and this has profound implications for the understanding and modelling of denitrification and N2O emission. Short anoxic spells caused by transient flooding during rainfall, could lead to subsequent unbalanced aerobic denitrification, in which N2O is a major end product.
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Affiliation(s)
- Nicholas Morley
- School of Biological Sciences, Plant and Soil Science, University of Aberdeen, Aberdeen, UK.
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43
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Oguz MT, Robinson KG, Layton AC, Sayler GS. Concurrent nitrite oxidation and aerobic denitrification in activated sludge exposed to volatile fatty acids. Biotechnol Bioeng 2007; 97:1562-72. [PMID: 17304559 DOI: 10.1002/bit.21379] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The goal of this research was to investigate the simultaneous occurrence of nitrification and denitrification by activated sludge exposed to volatile fatty acids (VFAs) during aerobic wastewater treatment using a single-stage reactor. A mixture of VFAs was spiked directly into a continuous-stirred tank reactor (CSTR) to assess subsequent impacts on nitrite removal, nitrate formation, CO(2) fixation, total bacterial density, and dominant nitrite oxidizing bacteria (NOB) concentration (i.e., Nitrospira). The activity of the periplasmic nitrate reductase (NAP) enzyme and the presence of nap gene were also measured. A rapid decrease in the nitrate formation rate (>70% reduction) was measured for activated sludge exposed to VFAs; however, the nitrite removal rate was not reduced. The total bacterial density and Nitrospira concentration remained essentially constant; therefore, the reduction in nitrate formation rate was likely not due to heterotrophic uptake of nitrogen or to a decrease in the dominant NOB population. Additionally, VFA exposure did not impact microbial CO(2) fixation efficiency. The activity of NAP enzyme increased in the presence of VFAs suggesting that nitrate produced as a consequence of nitrite oxidation was likely further reduced to gaseous denitrification products via catalysis by NAP. Little, if any, nitrogen was discharged in the aqueous effluent of the CSTR after exposure to VFAs demonstrating that activated sludge treatment yielded compounds other than those typically produced solely by nitrification.
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Affiliation(s)
- Merve T Oguz
- Department of Civil and Environmental Engineering, The University of Tennessee, Knoxville, Tennessee 37996, USA
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44
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Su JJ, Yeh KS, Tseng PW. A Strain of Pseudomonas sp. Isolated from Piggery Wastewater Treatment Systems with Heterotrophic Nitrification Capability in Taiwan. Curr Microbiol 2006; 53:77-81. [PMID: 16775792 DOI: 10.1007/s00284-006-0021-x] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2006] [Accepted: 03/15/2006] [Indexed: 11/30/2022]
Abstract
A high concentration of NH(4) (+) in piggery wastewater is major problem in Taiwan. Therefore, in our study, we isolated native heterotrophic nitrifiers for piggery wastewater treatment. Heterotrophic nitrifier AS-1 was isolated and characterized from the activated sludge of a piggery wastewater system. Sets of triplicate crimp-sealed serum bottles were used to demonstrate the heterotrophic nitrifying capability of strain AS-1 in an incubator at 30 degrees C. All serum bottles contained 80 mL medium, and the remainder of the bottle headspace was filled with pure oxygen. The experimental results showed that 2.5 +/- 0.2 mmol L(-1) NH(4) (+) was removed by 58 hours, and, eventually, 1.5 +/- 0.5 mmol L(-1) N(2) and 0.2 +/- 0.0 mmol L(-1) N(2)O were produced. The removal rate of NH(4) (+) by the strain AS-1 was 1.75 mmol NH(4) (+) g cell(-1) h(-1). This strain was then identified as Pseudomonas alcaligenes (97% identity) by sequencing its 16S rDNA and comparing it with other microorganisms. Thus, strain AS-1 displays high promise for future application for in situ NH(4) (+) removal from piggery wastewater.
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Affiliation(s)
- Jung-Jeng Su
- Division of Applied Biology, Animal Technology Institute Taiwan, Ding-Pu, Chunan, Miaoli, Taiwan, Republic of China.
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45
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46
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Oguz MT, Robinson KG, Layton AC, Sayler GS. Volatile fatty acid impacts on nitrite oxidation and carbon dioxide fixation in activated sludge. WATER RESEARCH 2006; 40:665-74. [PMID: 16436292 DOI: 10.1016/j.watres.2005.12.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2005] [Revised: 12/05/2005] [Accepted: 12/07/2005] [Indexed: 05/06/2023]
Abstract
Batch test were performed to assess nitrite removal, nitrate formation, CO2 fixation, gaseous nitrogen production and microbial density in activated sludge exposed to volatile fatty acid (VFA) mixtures. Nitrite removal and nitrate formation were both affected by the presence of VFAs, but to different degrees. Nitrate formation rates were reduced to a greater extent (79%) than nitrite removal rates (36%) resulting in an apparent unbalanced nitrite oxidation reaction. Since the total bacterial density and the nitrite oxidizing bacteria (NOB, Nitrospira) concentration remained essentially constant under all test conditions, the reduction in rates was not due to heterotrophic uptake of nitrogen or to a decrease in the NOB population. In contrast to the nitrogen results, VFAs were not found to impact CO2 fixation efficiency. It appeared that nitrite oxidation occurred when VFAs were present since the oxidation of nitrite provides energy for CO2 fixation. However, nitrate produced from the oxidation of nitrite was reduced to gaseous nitrogen products. N2O gas was detected in the presence of VFAs which was a clear indication that VFAs stimulated an alternative pathway, such as aerobic denitrification, during biotransformation of nitrogen in activated sludge.
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Affiliation(s)
- Merve T Oguz
- Department of Civil and Environmental Engineering, The University of Tennessee, Knoxville, TN 37996-2010, USA
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47
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Frette L, Gejlsbjerg B, Westermann P. Aerobic denitrifiers isolated from an alternating activated sludge system. FEMS Microbiol Ecol 2006. [DOI: 10.1111/j.1574-6941.1997.tb00453.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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48
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Rock JD, Mahnane MR, Anjum MF, Shaw JG, Read RC, Moir JWB. The pathogen Neisseria meningitidis requires oxygen, but supplements growth by denitrification. Nitrite, nitric oxide and oxygen control respiratory flux at genetic and metabolic levels. Mol Microbiol 2006; 58:800-9. [PMID: 16238628 DOI: 10.1111/j.1365-2958.2005.04866.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The human pathogen Neisseria meningitidis is the major causative agent of bacterial meningitis. The organism is usually treated as a strict aerobe and is cultured under fully aerobic conditions in the laboratory. We demonstrate here that although N. meningitidis fails to grow under strictly anaerobic conditions, under oxygen limitation the bacterium expresses a denitrification pathway (reduction of nitrite to nitrous oxide via nitric oxide) and that this pathway supplements growth. The expression of the gene aniA, which encodes nitrite reductase, is regulated by oxygen depletion and nitrite availability via transcriptional regulator FNR and two-component sensor-regulator NarQ/NarP respectively. Completion of the two-step denitrification pathway requires nitric oxide (NO) reduction, which proceeds after NO has accumulated during batch growth under oxygen-limited conditions. During periods of NO accumulation both nitrite and NO reduction are observed aerobically, indicating N. meningitidis can act as an aerobic denitrifier. However, under steady-state conditions in which NO is maintained at a low concentration, oxygen respiration is favoured over denitrification. NO inhibits oxidase activity in N. meningitidis with an apparent Ki NO = 380 nM measured in intact cells. The high respiratory flux to nitrite after microaerobic growth and the finding that accumulation of the denitrification intermediate NO inhibits oxygen respiration support the view that denitrification is a pathway of major importance in N. meningitidis.
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Affiliation(s)
- Jonathan D Rock
- Department of Biology (Area 10), University of York, Heslington, York YO10 5YW, UK
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49
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Qureshi N, Annous BA, Ezeji TC, Karcher P, Maddox IS. Biofilm reactors for industrial bioconversion processes: employing potential of enhanced reaction rates. Microb Cell Fact 2005; 4:24. [PMID: 16122390 PMCID: PMC1236956 DOI: 10.1186/1475-2859-4-24] [Citation(s) in RCA: 178] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2005] [Accepted: 08/25/2005] [Indexed: 12/13/2022] Open
Abstract
This article describes the use of biofilm reactors for the production of various chemicals by fermentation and wastewater treatment. Biofilm formation is a natural process where microbial cells attach to the support (adsorbent) or form flocs/aggregates (also called granules) without use of chemicals and form thick layers of cells known as "biofilms." As a result of biofilm formation, cell densities in the reactor increase and cell concentrations as high as 74 gL-1 can be achieved. The reactor configurations can be as simple as a batch reactor, continuous stirred tank reactor (CSTR), packed bed reactor (PBR), fluidized bed reactor (FBR), airlift reactor (ALR), upflow anaerobic sludge blanket (UASB) reactor, or any other suitable configuration. In UASB granular biofilm particles are used. This article demonstrates that reactor productivities in these reactors have been superior to any other reactor types. This article describes production of ethanol, butanol, lactic acid, acetic acid/vinegar, succinic acid, and fumaric acid in addition to wastewater treatment in the biofilm reactors. As the title suggests, biofilm reactors have high potential to be employed in biotechnology/bioconversion industry for viable economic reasons. In this article, various reactor types have been compared for the above bioconversion processes.
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Affiliation(s)
- Nasib Qureshi
- National Center for Agricultural Utilization Research, United States Department of Agriculture**, Agricultural Research Service, Fermentation Biotechnology Unit, 1815 N University Street, Peoria, IL 61604, USA
| | - Bassam A Annous
- Eastern Regional Research Center, United States Department of Agriculture, Agricultural Research Service, 600E Mermaid Lane, Wyndmoor, PA 19038, USA
| | - Thaddeus C Ezeji
- University of Illinois, Biotechnology & Bioengineering Group, Department of Food Science & Human Nutrition, 1207 W Gregory Drive, Urbana, IL 61801, USA
| | - Patrick Karcher
- University of Illinois, Biotechnology & Bioengineering Group, Department of Food Science & Human Nutrition, 1207 W Gregory Drive, Urbana, IL 61801, USA
| | - Ian S Maddox
- Massey Univesity, Institute of Engineering & Technology, Palmerston North, New Zealand
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50
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Holloway JM. Nitrogen and carbon flow from rock to water: Regulation through soil biogeochemical processes, Mokelumne River watershed, California, and Grand Valley, Colorado. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2004jf000124] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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