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Liu L, Xu S, Wang F, Yan Z, Tian Z, Ji M. Effect of exogenous N-acyl-homoserine lactones on the anammox process at 15 ℃: Nitrogen removal performance, gene expression and metagenomics analysis. BIORESOURCE TECHNOLOGY 2021; 341:125760. [PMID: 34454237 DOI: 10.1016/j.biortech.2021.125760] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 08/07/2021] [Accepted: 08/10/2021] [Indexed: 06/13/2023]
Abstract
In this study, C6-HSL and C8-HSL were separately introduced into anammox biofilm reactors to facilitate the anammox performance at 15 ℃. After operation 138 d, total nitrogen removal efficiencies in reactors with amendment C6-HSL or C8-HSL at 15 ℃ reached 76.2% and 74.6%, respectively. Content of extracellular polymeric substances increased by 19.8%, 67.7% and 121.2% in control group, C6-HSL and C8-HSL addition group, respectively. Genes associated with nitrogen removal (i.e., hzo, hzsB, nirS, and ccsB) showed higher expression level at amendment C6-HSL or C8-HSL group. Metagenomics analysis found that amendment of C6-HSL or C8-HL resulted in an increased abundance of genes related to the tricarboxylic acid cycle, amino sugar and nucleotide sugar metabolism, and also genes associated with amino acid biosynthesis pathways. Overall, amendment C6-HSL or C8-HSL had been confirmed as the effective method to improve the performance of anammox bioreactor at 15 ℃.
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Affiliation(s)
- Lingjie Liu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Sihan Xu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Fen Wang
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China.
| | - Zhao Yan
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Zhongke Tian
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Min Ji
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
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52
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Star polymer-mediated in-situ synthesis of silver-incorporated reverse osmosis membranes with excellent and durable biofouling resistance. J Memb Sci 2021. [DOI: 10.1016/j.memsci.2021.119778] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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53
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Wang X, Yu D, Chen G, Liu C, Xu A, Tang Z. Effects of interactions between quorum sensing and quorum quenching on microbial aggregation characteristics in wastewater treatment: A review. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2021; 93:2883-2902. [PMID: 34719836 DOI: 10.1002/wer.1657] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 10/14/2021] [Accepted: 10/26/2021] [Indexed: 06/13/2023]
Abstract
Due to the increasingly urgent demand for effective wastewater denitrification and dephosphorization systems, there is a need to improve the performance of existing biological treatment technologies. As a bacteria-level communication mechanism, quorum sensing (QS) synchronizes gene expression in a density-dependent manner and regulates bacterial physiological behavior. On this basis, the QS-based bacterial communication mechanism and environmental factors affecting QS are discussed. This paper reviews the influence of QS on sludge granulation, biofilm formation, emerging contaminants (ECs) removal, and horizontal gene transfer in sewage treatment system. Furthermore, the QS inhibition strategies are compared. Based on the coexistence and balance of QQ and QS in the long-term operation system, QQ, as an effective tool to regulate the growth density of microorganisms, provides a promising exogenous regulation strategy for residual sludge reduction and biofilm pollution control. This paper reviews the potential of improving wastewater treatment efficiency based on QS theory and points out the feasibility and prospect of exogenous regulation strategy. PRACTITIONER POINTS: The mechanism of bacterial communication based on QS and the environmental factors affecting QS were discussed. The application of QS and QQ in improving the sludge performance of biological treatment systems was described. The significance of QS and QQ coexistence in sewage treatment process was described.
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Affiliation(s)
- Xueping Wang
- School of Environmental Science and Engineering, Qingdao University, Qingdao, China
| | - Deshuang Yu
- School of Environmental Science and Engineering, Qingdao University, Qingdao, China
| | - Guanghui Chen
- School of Environmental Science and Engineering, Qingdao University, Qingdao, China
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing, China
| | - Chengju Liu
- School of Environmental Science and Engineering, Qingdao University, Qingdao, China
| | - Ao Xu
- School of Environmental Science and Engineering, Qingdao University, Qingdao, China
| | - Zhihao Tang
- School of Environmental Science and Engineering, Qingdao University, Qingdao, China
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Zhu Z, Zhang Y, Li J, Dong H. Insight into quorum sensing and microbial community of an anammox consortium in response to salt stress: From "Candaditus Brocadia" to "Candaditus Scalindua". THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 796:148979. [PMID: 34274671 DOI: 10.1016/j.scitotenv.2021.148979] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/04/2021] [Accepted: 07/07/2021] [Indexed: 06/13/2023]
Abstract
The shift of microbial community and signaling molecules release were studied to explore the potential mechanism of anammox consortium under salt stress. Due to increased salinity, the abundance of "Candidatus Brocadia" decreased from 29.5% to 1.9%. "Candidatus Brocadia" was reduced by the salinity shock. Besides, "Candidatus Scalindua", marine anammox bacteria, was detected at 18 g L-1 NaCl and dominated the reactor. Principle coordinates analysis further proved that salinity was the driving force on the distribution and diversity of anammox consortium. Also, quorum sensing feedback mechanism of anammox bacteria under salt stress was investigated for the first time. The concentration of N-(3-oxohexanoyl)-DL-homoserine lactone (3OC6-HSL) increased from 0.27 ± 0.02 to 1.24 ± 0.09 μM at 7 to 9 g L-1 NaCl. The concentration of 3OC6-HSL maintained at a high level at 9 to 12 g L-1 NaCl. Nacylated-l-homoserine lactones (AHLs)-mediated QS became more active and then improved the coordinated interaction in anammox consortium. High concentration of AHLs promoted the bacteria to produce more extracellular polymeric substances, which increased the bacterial tolerance to salt stress.
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Affiliation(s)
- Zebang Zhu
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, China
| | - Yulong Zhang
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, China
| | - Jin Li
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, China.
| | - Huiyu Dong
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-environmental Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100085, China
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55
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Rilstone V, Vignale L, Craddock J, Cushing A, Filion Y, Champagne P. The role of antibiotics and heavy metals on the development, promotion, and dissemination of antimicrobial resistance in drinking water biofilms. CHEMOSPHERE 2021; 282:131048. [PMID: 34470147 DOI: 10.1016/j.chemosphere.2021.131048] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 05/23/2021] [Accepted: 05/26/2021] [Indexed: 06/13/2023]
Abstract
Antimicrobial resistance (AMR), as well as the development of biofilms in drinking water distribution systems (DWDSs), have become an increasing concern for public health and management. As bulk water travels from source to tap, it may accumulate contaminants of emerging concern (CECs) such as antibiotics and heavy metals. When these CECs and other selective pressures, such as disinfection, pipe material, temperature, pH, and nutrient availability interact with planktonic cells and, consequently, DWDS biofilms, AMR is promoted. The purpose of this review is to highlight the mechanisms by which AMR develops and is disseminated within DWDS biofilms. First, this review will lay a foundation by describing how DWDS biofilms form, as well as their basic intrinsic and acquired resistance mechanisms. Next, the selective pressures that further induce AMR in DWDS biofilms will be elaborated. Then, the pressures by which antibiotic and heavy metal CECs accumulate in DWDS biofilms, their individual resistance mechanisms, and co-selection are described and discussed. Finally, the known human health risks and current management strategies to mitigate AMR in DWDSs will be presented. Overall, this review provides critical connections between several biotic and abiotic factors that influence and induce AMR in DWDS biofilms. Implications are made regarding the importance of monitoring and managing the development, promotion, and dissemination of AMR in DWDS biofilms.
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Affiliation(s)
- Victoria Rilstone
- Beaty Water Research Centre, Department of Civil Engineering, Union Street, Queen's University, Kingston, K7L 3Z6, Canada
| | - Leah Vignale
- Beaty Water Research Centre, Department of Civil Engineering, Union Street, Queen's University, Kingston, K7L 3Z6, Canada
| | - Justine Craddock
- Beaty Water Research Centre, Department of Civil Engineering, Union Street, Queen's University, Kingston, K7L 3Z6, Canada
| | - Alexandria Cushing
- Beaty Water Research Centre, Department of Civil Engineering, Union Street, Queen's University, Kingston, K7L 3Z6, Canada
| | - Yves Filion
- Beaty Water Research Centre, Department of Civil Engineering, Union Street, Queen's University, Kingston, K7L 3Z6, Canada.
| | - Pascale Champagne
- Beaty Water Research Centre, Department of Civil Engineering, Union Street, Queen's University, Kingston, K7L 3Z6, Canada; Institut National de la Recherche Scientifique (INRS), 490 rue de la Couronne, Québec City, Québec, G1K 9A9, Canada
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56
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Das S, Das S, Ghangrekar MM. Bacterial signalling mechanism: An innovative microbial intervention with multifaceted applications in microbial electrochemical technologies: A review. BIORESOURCE TECHNOLOGY 2021; 344:126218. [PMID: 34728350 DOI: 10.1016/j.biortech.2021.126218] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 10/20/2021] [Accepted: 10/22/2021] [Indexed: 02/05/2023]
Abstract
Microbial electrochemical technologies (METs) are a set of inventive tools that generate value-added by-products with concomitant wastewater remediation. However, due to the bottlenecks, like higher fabrication cost and inferior yield of resources, these inventive METs are still devoid of successful field-scale implementation. In this regard, application of quorum sensing (QS) mechanism to improve the power generation of the METs has gained adequate attention. The QS is an intercellular signalling mechanism that controls the bacterial social network in its vicinity via the synthesis of diffusible signal molecules labelled as auto inducers, thus ameliorating yield of valuables produced through METs. This state-of-the-art review elucidates different types of QS molecules and their working mechanism with the special focus on the widespread application of QS in the field of METs for their performance enhancement. Thus, this review intends to guide the researchers in rendering scalability to METs by integrating innovative QS mechanisms into them.
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Affiliation(s)
- Swati Das
- PK Sinha Centre for Bioenergy & Renewables, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India
| | - Sovik Das
- Department of Civil Engineering, Indian Institute of Technology Kharagpur, Kharagpur 21302, West Bengal, India
| | - M M Ghangrekar
- PK Sinha Centre for Bioenergy & Renewables, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India; Department of Civil Engineering, Indian Institute of Technology Kharagpur, Kharagpur 21302, West Bengal, India.
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57
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Cong S, Xu Y, Lu Y. Growth Coordination Between Butyrate-Oxidizing Syntrophs and Hydrogenotrophic Methanogens. Front Microbiol 2021; 12:742531. [PMID: 34603271 PMCID: PMC8481629 DOI: 10.3389/fmicb.2021.742531] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 08/18/2021] [Indexed: 11/13/2022] Open
Abstract
Syntrophy is a thermodynamically required mutualistic cooperation between fatty acid-oxidizing bacteria and methanogens that plays the important role in organic decomposition and methanogenesis in anoxic environments. In this study, three experiments were conducted to evaluate the cell-to-cell interaction in a thermophilic coculture consisting of Syntrophothermus lipocalidus and Methanocella conradii and a mesophilic coculture consisting of Syntrophomonas wolfei and Methanococcus maripaludis. First, syntrophs and methanogens were inoculated at different initial cell ratios to evaluate the growth synchronization. The quantitative PCR analysis revealed that the organism with a lower relative abundance at the beginning always grew faster, and the cell ratio converged over time to relative constant values in both the thermophilic and mesophilic cocultures. Next, intermittent ultrasound and constant shaking treatments were used to evaluate the influence of physical disturbance on microbial aggregation in the mesophilic coculture. The fluorescence in situ hybridization and scanning electron microscopy revealed that the tendency of syntrophic aggregation was not affected by the physical disturbances, although the activity was slightly depressed. Syntrophomonas dominated in the initial microbial aggregates, which, however, did not grow until Methanococcus was attached and increased to a significant extent, indicating the local growth synchronization during the formation and maturation of syntrophic aggregates. Last, microfluidic experiments revealed that whether or not Syntrophomonas or Methanococcus was loaded first, the second organism preferred moving to the place where the first organism was located, suggesting the cell-to-cell attraction between Syntrophomonas and Methanococcus. Collectively, our study demonstrated the growth synchronization and cell-to-cell attraction between the butyrate-oxidizing bacteria and methanogens for optimizing the syntrophic cooperation.
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Affiliation(s)
- Shuqi Cong
- College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Yiqin Xu
- College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Yahai Lu
- College of Urban and Environmental Sciences, Peking University, Beijing, China
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58
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Yan H, Li J, Meng J, Li J, Kumar Jha A, Zhang Y, Fan Y, Wang X. Effects of reflux ratio on the anaerobic sludge and microbial social behaviors in an expanded granular sludge bed reactor: From the perspective of acyl-homoserine lactones-mediated quorum sensing. BIORESOURCE TECHNOLOGY 2021; 337:125360. [PMID: 34116282 DOI: 10.1016/j.biortech.2021.125360] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 05/24/2021] [Accepted: 05/28/2021] [Indexed: 06/12/2023]
Abstract
Performance of anaerobic sludge and microbial social behaviors in an expanded granular sludge bed (EGSB) were evaluated by increasing reflux ratio from 50% to 500% stage by stage, with a constant influent chemical oxygen demand (COD) of 5500 mg/L at hydraulic retention time 12 h. The results indicated that the reflux ratio of 100% - 200% was more favorable for the EGSB with a methane production of 2.4 m3/m3·d. It was found that acyl-homoserine lactones (AHLs)-mediated quorum sensing (QS) could balance various microbial populations in the anaerobic digestion process. C4-HSL and C8-HSL were identified as the specific AHLs in enhancing granulation of anaerobic sludge by stimulating protein secretion into extracellular polymeric substances (EPS). 3-oxo-C6-HSL and 3-oxo-C14-HSL were verified for the enhancement of methanogenesis. The present study showed a novel perspective on the performance of EGSB with reflux ratios based on the AHLs-mediated QS.
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Affiliation(s)
- Han Yan
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, PR China
| | - Jianzheng Li
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, PR China.
| | - Jia Meng
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, PR China
| | - Jiuling Li
- Advanced Water Management Centre, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Avinash Kumar Jha
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, PR China
| | - Yafei Zhang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, PR China
| | - Yiyang Fan
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, PR China
| | - Xin Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, PR China
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59
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Zhou Q, Xie X, Feng F, Huang S, Sun Y. Impact of acyl-homoserine lactones on the response of nitrogen cycling in sediment to florfenicol stress. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 785:147294. [PMID: 33932672 DOI: 10.1016/j.scitotenv.2021.147294] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 04/17/2021] [Accepted: 04/17/2021] [Indexed: 06/12/2023]
Abstract
Antibiotic residuals disrupt environmental microbial metabolism and can alter the nitrogen cycle. Quorum sensing has both inter- and intra-species effects that are directly related to the population densities necessary for microbial nitrogen cycling. Here, we explored how acyl-homoserine lactones (AHLs) can change the response of nitrogen cycling to florfenicol in sediments. AHLs might promote microbial reproduction in sediment under florfenicol stress. The relative abundances of Proteobacteria and Euryarchaeota in the antibiotic and AHL treatment groups were higher than those in the control group. AHLs reduced the effects of antibiotics on the abundance of Nitrospira at sampling times of 3d, 10d, and 20d. In the annotation results, nitrate reductase showed the highest abundance, followed by nitrite reductase, nitrogenase, nitric oxide (NO) reductase, nitrous oxide reductase, and ammonia monooxygenase. The abundances of these genes have changed in response to pressure by florfenicol and the addition of AHLs. We also found significant associations between the nitrogen cycle-related functional genes and dominant genera. In particular, glutamate metabolic enzymes and nitrate/nitrite transporters were the primary participants in correlation. Florfenicol can rapidly alter microbial community structures in sediments, affect the functional diversity of microorganisms, and hinder the nitrogen cycle. The response of microorganisms to florfenicol was regulated by the addition of AHLs. This process might alter the use and production of nitrogenous substances in the environment by functional communities in sediments.
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Affiliation(s)
- Qin Zhou
- National Laboratory of Safety Evaluation (Environmental Assessment) of Veterinary Drugs, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, 483 Wushan Road, Guangzhou 510642, China; College of Life Sciences and Engineering, Foshan University, Foshan, Guangdong Province, China
| | - Xiying Xie
- National Laboratory of Safety Evaluation (Environmental Assessment) of Veterinary Drugs, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, 483 Wushan Road, Guangzhou 510642, China
| | - Fengling Feng
- National Laboratory of Safety Evaluation (Environmental Assessment) of Veterinary Drugs, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, 483 Wushan Road, Guangzhou 510642, China
| | - Shujian Huang
- College of Life Sciences and Engineering, Foshan University, Foshan, Guangdong Province, China
| | - Yongxue Sun
- National Laboratory of Safety Evaluation (Environmental Assessment) of Veterinary Drugs, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, 483 Wushan Road, Guangzhou 510642, China.
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60
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Zhang S, He X, Prodanovic V, Zhang K. Effect of filling ratio and backwash on performance of a continuous-flow SPD reactor packed with PCL as carbon source. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2021; 93:1381-1390. [PMID: 33539591 DOI: 10.1002/wer.1530] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/24/2021] [Accepted: 01/27/2021] [Indexed: 06/12/2023]
Abstract
In this study, three up-flow fixed-bed bioreactors, named as A, B, and C, packed with polycaprolactone (PCL) under different filling ratios (31%, 62%, and 93%, respectively), were investigated over a long period (96 days). During the stable period, the mean effluent NO 3 - - N concentrations in reactors A, B, and C were 1.35 ± 0.50, 1.07 ± 0.41, and 1.03 ± 0.27 mg/L, respectively, which showed the removal of NO 3 - - N was not closely related to filling ratio (p > 0.05, one-way ANOVA). However, it was found that biomass in reactor A was 2.13 and 5.55 times in B and C, respectively. Excessively thick biofilm refrained the enzymatic hydrolysis of PCL and biofilm's specific denitrification rate (SDNR). Backwash stimulated organic matter release and enabled biofilm to restore its denitrification activity. The maximum cycle of backwash was 6 days for the lowest filling ratio reactor. Additionally, the utilization rates for denitrification were 83.3%, 86.4%, and 60.5% in reactors A, B, and C, respectively, which was higher after backwash than before backwash. PRACTITIONER POINTS: Excessively thick biofilm refrained the enzymatic hydrolysis of PCL. Backwash stimulated organic matter release and enabled biofilm to restore its denitrification activity. The maximum cycle of backwash was 6 days for the lowest filling ratio reactor. A higher utilization rate of PCL for denitrification was observed after backwash.
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Affiliation(s)
- Shiyang Zhang
- School of Civil Engineering and Architecture, Wuhan University of Technology, Wuhan, China
| | - Xin He
- School of Civil Engineering and Architecture, Wuhan University of Technology, Wuhan, China
| | - Veljko Prodanovic
- Water Research Centre, School of Civil and Environmental Engineering, UNSW, Sydney, Australia
| | - Kefeng Zhang
- Water Research Centre, School of Civil and Environmental Engineering, UNSW, Sydney, Australia
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Dong Y, Sui M, Wang X, Zhang P, Jiang Y, Wu J. Responses of electroactive biofilms to chronic chlorine exposure: Insights from the composition and spatial structure of extracellular polymeric substances. Bioelectrochemistry 2021; 142:107894. [PMID: 34371350 PMCID: PMC8492042 DOI: 10.1016/j.bioelechem.2021.107894] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 07/20/2021] [Accepted: 07/21/2021] [Indexed: 11/29/2022]
Abstract
Extensive amounts of chlorine disinfectants have been applied to wastewater system since the outbreak of coronavirus disease 2019 (COVID-19), which inevitably affects the pollutant degradation via interfering with electron transfer mediated by electroactive bacteria. Herein, the response of electroactive biofilm (EAB) to chronic chlorine exposure was investigated. Results showed the EAB formed without exposure (EAB-0) exhibited a 53% and 123% higher current output than that formed with 0.1 mg L−1 (EAB-0.1) and 0.5 mg L−1 (EAB-0.5) chlorine, respectively. The chronic chlorine exposure of EAB boosted the contents of extracellular polymeric substances (EPS) in EAB-0.1 and EAB-0.5 by over secretion of extracellular polysaccharides. The EAB-0.1 and EAB-0.5 also presented lower electron exchange capacities (EECs) of EPS, coincided with reduced relative abundance of Geobacter from 61% in EAB-0 to 52% in EAB-0.5. This study provided new insights into the application of engineered EAB for wastewater treatment in a disinfection environment.
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Affiliation(s)
- Yue Dong
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China
| | - Mingrui Sui
- College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing 210098, China.
| | - Xin Wang
- MOE Key Laboratory of Pollution Processes and Environmental Criteria and Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Peng Zhang
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
| | - Yiying Jiang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China
| | - Jianyu Wu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China
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Wu S, Li S, Yin J, Yu Z. Hfq and sRNA00002 positively regulate the LuxI/LuxR-type quorum sensing system in Pseudoalteromonas. Biochem Biophys Res Commun 2021; 571:1-7. [PMID: 34298336 DOI: 10.1016/j.bbrc.2021.07.058] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 07/16/2021] [Indexed: 11/17/2022]
Abstract
Pseudoalteromonas spp. are Gram-negative bacteria which are ubiquitous in marine environments. Our previous work found that there is a classic LuxI/LuxR-type quorum sensing (QS) system which was named YasI/YasR in Pseudoalteromonas sp. R3, but the factors that control QS in strain R3 are unclear yet. Here, we found that the deficiency of hfq encoding RNA chaperon Hfq down-regulated the transcription levels of yasI encoding acyl-homoserine lactones (AHLs) synthase and yasR encoding AHLs receptor in strain R3. The assay based on fusion reporter of yasI-lacZ showed that Hfq regulates the expression of yasR at both transcriptional and translational levels. In addition, Hfq affects the expression of yasI via yasR. Further analysis indicated that the 5'UTR region of yasR is necessary for Hfq to control QS. In addition, the deletion of hfq increases the unstability of the target yasR mRNA. Based on transcriptome sequencing and bioinformatic analysis together with molecular experiments, Hfq-dependent sRNA00002 was identified to be involved in positively regulating QS in Pseudoalternas sp. R3. It was found that sRNA00002 deficiency causes the decrease in expression of yasI and yasR, and thus abolishes the production of AHLs in strain R3. It was concluded that Hfq-dependent sRNA00002 regulates yasR expression by base-pairing with target yasR mRNA at 5'UTR region and altering the stability of yasR mRNA. Our work paves the way for understanding the regulation mechanism of Hfq-dependent sRNAs on QS in Pseudoalteromonas.
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Affiliation(s)
- Shijun Wu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Shuangjia Li
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Jianhua Yin
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Zhiliang Yu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China.
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Liu Q, Wang J, Ren H. Bacterial assembly and succession in the start-up phase of an IFAS metacommunity: The role of AHL-driven quorum sensing. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 777:145870. [PMID: 33689899 DOI: 10.1016/j.scitotenv.2021.145870] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/07/2021] [Accepted: 02/09/2021] [Indexed: 05/06/2023]
Abstract
Quorum sensing (QS) plays an important role in biofilm formation and the start-up of biofilm-based reactors, while its involvement in bacterial assembly throughout biofilm development remains underexplored. We investigated the assembly and succession of the bacterial community in a full-scale integrated fixed-film activated sludge (IFAS) process, with emphasis on N-acylhomoserine lactone (AHL)-driven QS. Biofilm development could be divided into two major periods, (i) young biofilm formation phase and (ii) biofilm maturity and update phase. Mature biofilms exhibited lower levels of AHLs compared with young biofilms (p > 0.05). A structural equation model, constructed to assess the linkages between AHL level and bacterial community composition as well as environmental factors, indicated that pH significantly influenced both bacterial community composition and AHL content. Along with biofilm development, there was a negative correlation between AHL concentration and community composition variation (coefficients of -0.367 and -0.329). Regarding the lower AHL level in mature biofilms, these results were consistent with the phylogenetic molecular ecological networks (pMENs) analysis, indicating that quorum-quenching (QQ) bacteria occur in keystone taxa in mature biofilms. In addition, based on the pMENs results, the proportion of positive interactions increased from 77.64 to 82.39% in mature biofilms compared to young biofilms, indicating that bacterial cooperation was strengthened in mature biofilms. The QS bacteria were predominant in the keystone taxa of pMENs, with proportions being increased to 62% in mature biofilms, which is conducive for biofilm development. Overall, this study improves our understanding of the involvement of AHL-mediated QS in biofilm development.
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Affiliation(s)
- Qiuju Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Jinfeng Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China.
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Gao H, Zhang W, Zhang J, Huang Y, Zhang J, Tian J, Niu Y, Zou C, Jia C, Chang Z, Yang X, Jiang D. Methionine biosynthesis pathway genes affect curdlan biosynthesis of Agrobacterium sp. CGMCC 11546 via energy regeneration. Int J Biol Macromol 2021; 185:821-831. [PMID: 34216670 DOI: 10.1016/j.ijbiomac.2021.06.189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 06/08/2021] [Accepted: 06/28/2021] [Indexed: 11/28/2022]
Abstract
Curdlan is a water-insoluble exopolysaccharide produced by Agrobacterium species under nitrogen starvation. The curdlan production in the ΔmdeA, ΔmetA, ΔmetH, and ΔmetZ mutants of methionine biosynthesis pathway of Agrobacterium sp. CGMCC 11546 were significantly impaired. Fermentation profiles of four mutants showed that the consumption of ammonia and sucrose was impaired. Transcriptome analysis of the ΔmetH and ΔmetZ mutants showed that numerous differentially expressed genes involved in the electron transfer chain (ETC) were significantly down-regulated, suggesting that methionine biosynthesis pathway affected the production of energy ATP during the curdlan biosynthesis. Furthermore, metabolomics analysis of the ΔmetH and ΔmetZ mutants showed that ADP and FAD were significantly accumulated, while acetyl-CoA was diminished, suggesting that the impaired curdlan production in the ΔmetH and ΔmetZ mutants might be caused by the insufficient supply of energy ATP. Finally, the addition of both dibasic sodium succinate as a substrate of FAD recycling and methionine significantly restored the curdlan production of four mutants. In conclusion, methionine biosynthesis pathway plays an important role in curdlan biosynthesis in Agrobacterium sp. CGMCC 11546, which affected the sufficient supply of energy ATP from the ETC during the curdlan biosynthesis.
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Affiliation(s)
- Hongliang Gao
- School of Life Sciences, East China Normal University, Shanghai 200241, PR China
| | - Wei Zhang
- School of Life Sciences, East China Normal University, Shanghai 200241, PR China
| | - Jing Zhang
- School of Life Sciences, East China Normal University, Shanghai 200241, PR China
| | - Yimin Huang
- School of Life Sciences, East China Normal University, Shanghai 200241, PR China
| | - Jingyu Zhang
- School of Life Sciences, East China Normal University, Shanghai 200241, PR China
| | - Jiangtao Tian
- School of Life Sciences, East China Normal University, Shanghai 200241, PR China
| | - Yanning Niu
- School of Life Sciences, East China Normal University, Shanghai 200241, PR China
| | - Chunjing Zou
- School of Life Sciences, East China Normal University, Shanghai 200241, PR China
| | - Caifeng Jia
- School of Life Sciences, East China Normal University, Shanghai 200241, PR China
| | - Zhongyi Chang
- School of Life Sciences, East China Normal University, Shanghai 200241, PR China
| | - Xuexia Yang
- College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, PR China.
| | - Deming Jiang
- School of Life Sciences, East China Normal University, Shanghai 200241, PR China.
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Wang N, Gao J, Liu Y, Wang Q, Zhuang X, Zhuang G. Realizing the role of N-acyl-homoserine lactone-mediated quorum sensing in nitrification and denitrification: A review. CHEMOSPHERE 2021; 274:129970. [PMID: 33979914 DOI: 10.1016/j.chemosphere.2021.129970] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 02/04/2021] [Accepted: 02/08/2021] [Indexed: 06/12/2023]
Abstract
Nitrification and denitrification are crucial processes in the nitrogen cycle, a vital microbially driven biogeochemical cycle. N-acyl-homoserine lactone (AHL)-mediated quorum sensing (QS) is widespread in bacteria and plays a key role in their physiological status. Recently, there has been an increase in research into how the AHL-mediated QS system is involved in nitrification and denitrification. Consequentially, the AHL-mediated QS system has been considered a promising regulatory approach in nitrogen metabolism processes, with high potential for real-world applications. In this review, the universal presence of QS in nitrifiers and denitrifiers is summarized. Many microorganisms taking part in nitrification and denitrification harbor QS genes, and they may produce AHLs with different chain lengths. The phenotypes and processes affected by QS in real-world applications are also reviewed. In wastewater bioreactors, QS could affect nitrogen metabolism efficiency, granule aggregation, and biofilm formation. Furthermore, methods commonly used to identify the existence and functions of QS, including physiological tests, genetic manipulation and omics analyses are discussed.
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Affiliation(s)
- Na Wang
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jie Gao
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Ying Liu
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; School of Life Sciences, University of Science and Technology of China, Hefei, 230026, China
| | - Qiuying Wang
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xuliang Zhuang
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Guoqiang Zhuang
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China.
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Cui Y, Gao H, Yu R, Gao L, Zhan M. Biological-based control strategies for MBR membrane biofouling: a review. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2021; 83:2597-2614. [PMID: 34115616 DOI: 10.2166/wst.2021.168] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Membrane bioreactor (MBR) technology has been paid extensive attention for wastewater treatment because of its advantages of high effluent quality and minimized occupation space and sludge production. However, the membrane fouling is always an inevitable problem, which causes high operation and maintenance costs and prevents the wide use of MBR technology. The membrane biofouling is the most complicated and has relatively slow progress among all types of fouling. In recent years, many membrane biofouling control methods have been developed. Different from the physical or chemical methods, the biological-based strategies are not only more effective for membrane biofouling control, but also milder and more environment-friendly and, therefore, have been increasingly employed. This paper mainly focuses on the mechanism, unique advantages and development of biological-based control strategies for MBR membrane biofouling such as quorum quenching, uncoupling, flocculants and so on. The paper summarizes the up-to-date development of membrane biofouling control strategies, emphasizes the advantages and promising potential of biological-based ones, and points out the direction for future studies.
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Affiliation(s)
- Yin Cui
- Department of Environmental Science and Engineering, School of Energy and Environment, Wuxi Engineering Research Center of Taihu Lake Water Environment, Southeast University, Nanjing, Jiangsu 210096, China and Key Laboratory of Environmental Medicine Engineering, Ministry of Education, Southeast University, Nanjing, Jiangsu 210009, China E-mail:
| | - Huan Gao
- Department of Environmental Science and Engineering, School of Energy and Environment, Wuxi Engineering Research Center of Taihu Lake Water Environment, Southeast University, Nanjing, Jiangsu 210096, China and Key Laboratory of Environmental Medicine Engineering, Ministry of Education, Southeast University, Nanjing, Jiangsu 210009, China E-mail:
| | - Ran Yu
- Department of Environmental Science and Engineering, School of Energy and Environment, Wuxi Engineering Research Center of Taihu Lake Water Environment, Southeast University, Nanjing, Jiangsu 210096, China and Key Laboratory of Environmental Medicine Engineering, Ministry of Education, Southeast University, Nanjing, Jiangsu 210009, China E-mail:
| | - Lei Gao
- Department of Environmental Science and Engineering, School of Energy and Environment, Wuxi Engineering Research Center of Taihu Lake Water Environment, Southeast University, Nanjing, Jiangsu 210096, China and Key Laboratory of Environmental Medicine Engineering, Ministry of Education, Southeast University, Nanjing, Jiangsu 210009, China E-mail:
| | - Manjun Zhan
- Nanjing Research Institute of Environmental Protection, Nanjing Environmental Protection Bureau, Nanjing, Jiangsu 210013, China
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Uman AE, Bair RA, Yeh DH. Assessment of an Anaerobic Membrane Bioreactor (AnMBR) Treating Medium-Strength Synthetic Wastewater under Cyclical Membrane Operation. MEMBRANES 2021; 11:415. [PMID: 34072658 PMCID: PMC8226899 DOI: 10.3390/membranes11060415] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/24/2021] [Accepted: 05/28/2021] [Indexed: 12/30/2022]
Abstract
A lab-scale (6.2 L) anaerobic membrane bioreactor combined with a tubular, cross-flow, PVDF ultrafiltration membrane was developed and operated to assess the long-term fouling behavior of a cyclically operated anaerobic membrane bioreactor (AnMBR). The AnMBR was operated at 35 ± 1 °C for 200 days with a synthetic influent of 501 mg·L-1 COD to mimic municipal wastewater. The system exhibited high treatment performance with an average COD removal efficiency of 86.5 ± 6.4% (n = 20) and an average permeate COD concentration of 63.9 ± 31.1 mg·L-1. A clear permeate with an average turbidity of 0.6 ± 0.2 NTU, was achieved. Permeate TN and TP concentrations were 22.7 ± 5.1 mg·L-1 and 6.9 ± 2.0 mg·L-1 corresponding to removal efficiencies of 20.6% and 49.3%, respectively, likely due to membrane rejection of particulate, colloidal, and organic fractions. A stable membrane flux of 4.3 L.m-2.h-1 (LMH) was maintained for 183 days without gas-lift, gas sparge, or chemical cleaning. Cyclical operation with frequent relaxation (60 s for every 30 min of the permeate production run) and periodic permeate backwash (15 s for every 186 min) maintained stable membrane operation with an average TMP of 0.25 bar and a fouling rate of 0.007 kPa/h for the entire operating period. The comparison revealed frequent backwashing and relaxation is a sustainable strategy for operation of the AnMBR.
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Affiliation(s)
- Ahmet E. Uman
- Department of Civil and Environmental Engineering, University of South Florida, Tampa, FL 33617, USA; (R.A.B.); (D.H.Y.)
- Bioengineering Department, Istanbul Medeniyet University, Istanbul 34000, Turkey
| | - Robert A. Bair
- Department of Civil and Environmental Engineering, University of South Florida, Tampa, FL 33617, USA; (R.A.B.); (D.H.Y.)
| | - Daniel H. Yeh
- Department of Civil and Environmental Engineering, University of South Florida, Tampa, FL 33617, USA; (R.A.B.); (D.H.Y.)
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N-acyl homoserine lactone molecules assisted quorum sensing: effects consequences and monitoring of bacteria talking in real life. Arch Microbiol 2021; 203:3739-3749. [PMID: 34002253 DOI: 10.1007/s00203-021-02381-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 05/10/2021] [Accepted: 05/11/2021] [Indexed: 12/19/2022]
Abstract
Bacteria utilize small signal molecules to monitor population densities. Bacteria arrange gene regulation in a method called Quorum Sensing (QS). The most widespread signalling molecules are N-Acyl Homoserine Lactones (AHLs/HSLs) for Gram-negative bacteria communities. QS plays significant role in the organizing of the bacterial gene that adapts to harsh environmental conditions for bacteria. It is involved in the arrangement of duties, such as biofilm formation occurrence, virulence activity of bacteria, production of antibiotics, plasmid conjugal transfer incident, pigmentation phenomenon and production of exopolysaccharide (EPS). QS obviously impacts on human health, agriculture and environment. AHL-related QS researches have been extensively studied and understood in depth for cell to cell intercommunication channel in Gram-negative bacteria. It is understood that AHL-based QS research has been extensively studied for cell-to-cell communication in Gram-negative bacteria; hence, a comprehensive study of AHLs, which are bacterial signal molecules, is required. The purpose of this review is to examine the effects of QS-mediated AHLs in many areas by looking at them from a different perspectives, such as clinic samples, food industry, aquatic life and wastewater treatment system.
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Liu J, Wu P, Guo Q, Lai X, Ruan B, Wang H, Rehman S, Chen M. Kaolinite weakens the co-stress of ampicillin and tetracycline on Escherichia coli through multiple pathways. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:25228-25240. [PMID: 33453031 DOI: 10.1007/s11356-021-12356-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Accepted: 01/02/2021] [Indexed: 06/12/2023]
Abstract
Ampicillin and tetracycline are common antibiotics and can threaten humans by inducing antibiotic resistance in bacteria. Microorganisms are usually exposed to a mixed antibiotic system in the environment. However, there are few researches on the specific regulatory mechanisms of clay on microorganisms under the stress of complex antibiotics. In this study, tandem mass tag-based coupled with two-dimensional liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) was employed to recognize and quantify changes in protein expression of Escherichia coli (E. coli) after culture for 15 days, with or without kaolinite in the co-stress of ampicillin and tetracycline. The results indicated that kaolinite could activate metabolic pathways of E. coli such as the energy metabolism, the biosynthesis of other secondary metabolites, and the metabolism of cofactors and vitamins. Particularly, the fatty acid degradation pathway has also been promoted, indicating that in the same unfavorable environment, kaolinite might influence the composition of E. coli cell membranes. This might be due to the change in membrane composition that was a kind of adaptive strategy of bacterial evolution. Moreover, kaolinite could promote multidrug efflux system to export the bacterial intracellular toxic substances, making E. coli survive better in an adverse environment. Consequently, this study not only disclosed the regulation of kaolinite on E. coli in a complex antibiotic environment but also provided new insights into the environmental process of antibiotic resistance.
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Affiliation(s)
- Juan Liu
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, People's Republic of China
| | - Pingxiao Wu
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, People's Republic of China.
- The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou, 510006, People's Republic of China.
- Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, South China University of Technology, Guangzhou, 510006, People's Republic of China.
- Guangdong Provincial Engineering and Technology Research Center for Environmental Risk Prevention and Emergency Disposal, Guangzhou, 510006, People's Republic of China.
- Guangdong Engineering and Technology Research Center for Environmental Nanomaterials, Guangzhou, 510006, People's Republic of China.
| | - Qing Guo
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, People's Republic of China
| | - Xiaolin Lai
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, People's Republic of China
| | - Bo Ruan
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, People's Republic of China
| | - Huimin Wang
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, People's Republic of China
| | - Saeed Rehman
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, People's Republic of China
| | - Meiqing Chen
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, People's Republic of China
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Wang J, Liu Q, Dong D, Hu H, Wu B, Ren H. AHLs-mediated quorum sensing threshold and its response towards initial adhesion of wastewater biofilms. WATER RESEARCH 2021; 194:116925. [PMID: 33609904 DOI: 10.1016/j.watres.2021.116925] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/29/2021] [Accepted: 02/11/2021] [Indexed: 06/12/2023]
Abstract
Quorum sensing (QS) plays a crucial role during initial biofilm formation, however the QS threshold and the response of biofilm formation towards N-acyl-homoserine lactones (AHLs) remains largely unknown due to the limitation of nondestructive online methods for monitoring bacterial adherence and the complexity of QS system, which limits the application of QS signal reagents in biofilm reactors. In this study, bacterial QS threshold and its response of biofilm formation to AHLs in purely cultured Sphingomonas rubra biofilm as well as in three different wastewater biofilms #1-3 were investigated via real time cell analysis (RTCA). The main perspective was to study the biomass adherence in response to 12 different forms of AHLs at different concentrations. Results showed that bacterial adhesion was significantly improved by exogenous AHLs with the maximum increase of 2.26-, 2.36-, 2.52-, and 2.80- times biomass production in the four respective biofilms. Although the preferred form of AHL differed for various biofilms, the long-chain AHLs (12-14 carbons) resulted in an overall improvement of bacterial adhesion due to their stronger hydrophobicity and hydrolysis resistance. In addition, bacterial QS threshold of AHLs was observed to have a wide range of concentration from 10 ng/L to 10 μg/L. Meanwhile, QS response time to AHLs also showed a significant difference in different biofilms. Biofilm #2 inoculated with bulking sludge had lower QS threshold of 10 ng/L and faster response to most AHLs that is less than 6 h. Thus, considering the improvement of biofilm adhesion by AHLs, 10 ng/L of C12-HSL, 10 ng/L of C12-HSL, and 10 ng/L of C6-HSL were preferentially selected for wastewater biofilms #1-3 respectively. Unexpectedly, adding high-concentration of AHLs detected in sludges did not significantly improved the bacterial adhesion. Infact the addition of these AHLs at low concentrations or even undetected concentrations substantially improved bacterial adhesion, which could be explained by bacterial communities composition. According to the Pearson correlation analysis, 62% of the top 50 most abundant genera in bacterial communities were significantly negatively related to the response time of multiple AHLs, representing their fast QS response. The QS bacteria, Dechloromonas and Nitrospira have fast QS response for C4-HSL and C8-HSL while, Comamonadaceae has fast QS response for 3OC8-HSL, 3OC10-HSL, 3OC12-HSL, and 3OC14-HSL. In contrast, the rest 38% of the top most abundant genera, such as Ferruginibacter, Hyphomicrobium, and Terrimonas quickly responded to only one AHL, showing significant negative relationship with the response time of C6-HSL. Overall, this study provides an effective and convenient means to select appropriate AHL reagents to promote bacterial adhesion in biofilm systems. Moreover, it also suggests that exogenous AHLs may be useful in improving the settling property of bulking sludge.
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Affiliation(s)
- Jinfeng Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, P.R. China
| | - Qiuju Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, P.R. China
| | - Deyuan Dong
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, P.R. China
| | - Haidong Hu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, P.R. China
| | - Bing Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, P.R. China
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, P.R. China.
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Wang Q, Zhang T, Wu G, Xu Q. Deciphering acyl-homoserine lactones-mediated quorum sensing on geotextile bio-clogging in municipal solid waste and bottom ash co-disposal landfills. WASTE MANAGEMENT (NEW YORK, N.Y.) 2021; 124:136-143. [PMID: 33621757 DOI: 10.1016/j.wasman.2021.02.001] [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: 08/19/2020] [Revised: 01/19/2021] [Accepted: 02/01/2021] [Indexed: 06/12/2023]
Abstract
Bottom ash co-disposed in landfills accelerates geotextile clogging and decreases landfill stability. As the main contributor to clogging, bio-clogging may be associated with quorum sensing (QS) in microbial communities. This study investigated the potential roles of acyl-homoserine lactones (AHLs)-mediated QS in geotextile bio-clogging under different landfill conditions, including municipal solid waste landfill and bottom ash co-disposal landfill. The unit area of geotextile bio-clogging mass in the municipal solid waste landfill (MSW_G) ranged from 5.2 × 10-3 to 8.2 × 10-3 g/cm2, while it was in the range of 8.4 × 10-3 to 1.2 × 10-2 g/cm2 in the bottom ash co-disposal landfill (BA_G). Two types of AHLs were detected and the total AHLs content in the MSW_G (1,616.9 ± 103.8 ng/g VSS) was half of that in the BA_G (3,233.0 ± 646.8 ng/g VSS). High contents of the AHLs could increase bio-clogging. The bio-clogging was also attributed to QS genes and extracellular polymeric substances (EPS). EPS aggregation was stimulated due to the higher Ca2+ and Mg2+ in the BA_G. These results suggested that the co-disposal of bottom ash could increase the AHLs content, resulting in accelerated bio-clogging.
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Affiliation(s)
- Qian Wang
- School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Tianqi Zhang
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Guangxue Wu
- Civil Engineering, School of Engineering, College of Science and Engineering, National University of Ireland, Galway, Galway, Ireland
| | - Qiyong Xu
- School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
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Li M, Wu Y, Wang Z, Fu W, Dang W, Chen Y, Ning Y, Wang S. Improvement in calcified anaerobic granular sludge performance by exogenous acyl-homoserine lactones. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 210:111874. [PMID: 33421723 DOI: 10.1016/j.ecoenv.2020.111874] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 12/24/2020] [Accepted: 12/26/2020] [Indexed: 06/12/2023]
Abstract
Given the high content of Ca2+ in waste paper recycling wastewater, the anaerobic granular sludge (AnGS) undergoes calcification during wastewater treatment and affects the treatment efficiency. To restore the activity of calcified AnGS and improve the performance of AnGS, four types of N-acyl-homoserine lactones (AHLs) were added to the AnGS system while papermaking wastewater treatment. The addition of N-butyryl-DL-homoserine lactone(C4-HSL) and N-octanoyl-DL-homoserine lactone (C8-HSL) had an inhibitory affect the COD removal efficiency and SMA of sludge at the inception. The addition of N-hexanoyl-L-homoserine lactone (C6-HSL) has no obvious effect on the COD removal efficiency, but can improve the SMA of sludge more obviously. The addition of N-(β-ketocaproyl)-DL-homoserine lactone (3O-C6-HSL) can increased COD removal efficiency and promoted SMA together obviously. The addition of C6-HSL and 3O-C6-HSL can increase volatile suspended solid (VSS)/total suspended solid (TSS), and regulate extracellular polymeric substance (EPS) secretion in AnGS. Analysis of microbial sequencing revealed changes in the microbial community structure following AHL addition, which enhanced the methane metabolism pathway in sludge. The addition of C6-HSL, C8-HSL, and 3O-C6-HSL increased Methanosaeta population, thus increasing the aceticlastic pathway in sludge. Thus, exogenous AHLs can play an important role in regulating microbial community structure, and in improving the performance of AnGS.
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Affiliation(s)
- Meiling Li
- Guangxi Key Lab of Clean Pulp & Papermaking and Pollution Control, Light Industrial and Food Engineering College, Guangxi University, Nanning 530004, China
| | - Yueru Wu
- Guangxi Key Lab of Clean Pulp & Papermaking and Pollution Control, Light Industrial and Food Engineering College, Guangxi University, Nanning 530004, China
| | - Zhiwei Wang
- Guangxi Key Lab of Clean Pulp & Papermaking and Pollution Control, Light Industrial and Food Engineering College, Guangxi University, Nanning 530004, China; Guangxi Bossco Environment Protection Technology Co., Ltd, Nanning 530007, China.
| | - Wencai Fu
- Guangxi Key Lab of Clean Pulp & Papermaking and Pollution Control, Light Industrial and Food Engineering College, Guangxi University, Nanning 530004, China
| | - Wenhao Dang
- Guangxi Key Lab of Clean Pulp & Papermaking and Pollution Control, Light Industrial and Food Engineering College, Guangxi University, Nanning 530004, China
| | - Yongli Chen
- Key Laboratory of Pulp and Paper Science & Technology of Ministry of Education/Shandong Province, Qilu University of Technology, Jinan 250353, China
| | - Yi Ning
- Key Laboratory of Pulp and Paper Science & Technology of Ministry of Education/Shandong Province, Qilu University of Technology, Jinan 250353, China
| | - Shuangfei Wang
- Guangxi Key Lab of Clean Pulp & Papermaking and Pollution Control, Light Industrial and Food Engineering College, Guangxi University, Nanning 530004, China.
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Hu H, Luo F, Liu Y, Zeng X. Function of quorum sensing and cell signaling in wastewater treatment systems. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2021; 83:515-531. [PMID: 33600358 DOI: 10.2166/wst.2020.601] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Quorum sensing (QS) is a communication mode between microorganisms to regulate bacteria ecological relations and physiological behaviors, thus achieve the physiological function that single bacteria cannot complete. This phenomenon plays important roles in the formation of biofilm and granular sludge, and may be related to enhancement of some functional bacteria activity in wastewater treatment systems. There is a need to better understand bacterial QS in engineered reactors, and to assess how designs and operations might improve the removal efficiency. This article reviewed the recent advances of QS in several environmental systems and mainly analyzed the regulation mechanism of QS-based strategies for biofilm, granular sludge, functional bacteria, and biofouling control. The co-existences of multiple signal molecules in wastewater treatment (WWT) processes were also summarized, which provide basis for the future research on the QS mechanism of multiple signal molecules' interaction in WWT. This review would present some prospects and suggestions which are of practical significance for further application.
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Affiliation(s)
- Huizhi Hu
- Faculty of Resources and Environmental Science, Hubei University, Wuhan 430062, China; Hubei Key Laboratory of Regional Development and Environmental Response, Wuhan 430062, China
| | - Feng Luo
- Faculty of Resources and Environmental Science, Hubei University, Wuhan 430062, China
| | - Yirong Liu
- Faculty of Resources and Environmental Science, Hubei University, Wuhan 430062, China
| | - Xiangguo Zeng
- Wuhan planning and design co., LTD, Wuhan 430010, China E-mail:
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Zhu Z, Shan L, Zhang X, Hu F, Zhong D, Yuan Y, Zhang J. Effects of bacterial community composition and structure in drinking water distribution systems on biofilm formation and chlorine resistance. CHEMOSPHERE 2021; 264:128410. [PMID: 33002803 DOI: 10.1016/j.chemosphere.2020.128410] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 08/25/2020] [Accepted: 09/19/2020] [Indexed: 06/11/2023]
Abstract
Community-intrinsic properties affect the composition and function of a microbial community. Understanding the microbial community-intrinsic properties in drinking water distribution systems (DWDS) could help to select disinfection strategies and aid in the prevention of waterborne infectious diseases. In this study, we investigated the formation of multi-species biofilms in six groups, each consisting of four or five mixed bacterial strains isolated from a simulated DWDS, at different incubation times (24, 48, and 72 h). We then evaluated the chlorine resistance of the 72-h multi-species biofilms in the presence of 0.3, 0.6, 1, 2, 4, and 10 mg/L residual chlorine. Microbacterium laevaniformans inhibited the formation of multi-species biofilms, Sphingomonas sp., Acinetobacter sp. and A. deluvii had the effect of promoting their growth, and B. cereus has little effect on the growth of multi-species biofilms. However, these inhibition and promotion effects were weak and inadequate to completely control the growth of multi-species biofilms. All multi-species produced strong biofilms after 72 h incubation, which could be due to microbial community-intrinsic properties. Community-intrinsic properties could maintain high EPS production and cell-to-cell connections in multi-species biofilms, and could affect the formation of multi-species biofilms. The chlorine resistance of multi-species biofilms was significantly improved by B. cereus, but significantly reduced by M. laevaniformans. These results indicated that the microbial community-intrinsic properties were influenced by the environment. At a relatively low disinfectant concentration (<2 mg/L residual chlorine), the community-intrinsic properties were maintained; however, when the disinfectant concentration was increased to 2-4 mg/L residual chlorine, the community-intrinsic properties weakened, and significantly affected the resistance of the microbial communities to the disinfectant. With further increases in concentration, to >4 mg/L residual chlorine, no significant difference was observed in the disinfectant resistance of the microbial community.
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Affiliation(s)
- Zebing Zhu
- School of Civil Engineering and Architecture, East China Jiao Tong University, Nanchang, 330013, PR China; State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, PR China.
| | - Lili Shan
- School of Civil Engineering and Architecture, East China Jiao Tong University, Nanchang, 330013, PR China
| | - Xinyun Zhang
- School of Civil Engineering and Architecture, East China Jiao Tong University, Nanchang, 330013, PR China
| | - Fengping Hu
- School of Civil Engineering and Architecture, East China Jiao Tong University, Nanchang, 330013, PR China.
| | - Dan Zhong
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, PR China
| | - Yixing Yuan
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, PR China
| | - Jie Zhang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, PR China
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75
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Pavissich JP, Li M, Nerenberg R. Spatial distribution of mechanical properties in Pseudomonas aeruginosa biofilms, and their potential impacts on biofilm deformation. Biotechnol Bioeng 2021; 118:1564-1575. [PMID: 33415727 DOI: 10.1002/bit.27671] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 01/01/2021] [Accepted: 01/04/2021] [Indexed: 11/08/2022]
Abstract
The mechanical properties of biofilms can be used to predict biofilm deformation under external forces, for example, under fluid flow. We used magnetic tweezers to spatially map the compliance of Pseudomonas aeruginosa biofilms at the microscale, then applied modeling to assess its effects on biofilm deformation. Biofilms were grown in capillary flow cells with Reynolds numbers (Re) ranging from 0.28 to 13.9, bulk dissolved oxygen (DO) concentrations from 1 mg/L to 8 mg/L, and bulk calcium ion (Ca2+ ) concentrations of 0 and 100 mg CaCl2 /L. Higher Re numbers resulted in more uniform biofilm morphologies. The biofilm was stiffer at the center of the flow cell than near the walls. Lower bulk DO led to more stratified biofilms. Higher Ca2+ concentrations led to increased stiffness and more uniform mechanical properties. Using the experimental mechanical properties, fluid-structure interaction models predicted up to 64% greater deformation for heterogeneous biofilms, compared with a homogeneous biofilms with the same average properties. However, the deviation depended on the biofilm morphology and flow regime. Our results show significant spatial mechanical variability exists at the microscale, and that this variability can potentially affect biofilm deformation. The average biofilm mechanical properties, provided in many studies, should be used with caution when predicting biofilm deformation.
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Affiliation(s)
- Juan P Pavissich
- Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Santiago, Chile.,Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile.,Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Mengfei Li
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Robert Nerenberg
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana, USA
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76
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Ranava D, Backes C, Karthikeyan G, Ouari O, Soric A, Guiral M, Cárdenas ML, Giudici-Orticoni MT. Metabolic Exchange and Energetic Coupling between Nutritionally Stressed Bacterial Species: Role of Quorum-Sensing Molecules. mBio 2021; 12:e02758-20. [PMID: 33468690 PMCID: PMC7845633 DOI: 10.1128/mbio.02758-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 11/18/2020] [Indexed: 12/29/2022] Open
Abstract
Formation of multispecies communities allows nearly every niche on earth to be colonized, and the exchange of molecular information among neighboring bacteria in such communities is key for bacterial success. To clarify the principles controlling interspecies interactions, we previously developed a coculture model with two anaerobic bacteria, Clostridium acetobutylicum (Gram positive) and Desulfovibrio vulgaris Hildenborough (Gram negative, sulfate reducing). Under conditions of nutritional stress for D. vulgaris, the existence of tight cell-cell interactions between the two bacteria induced emergent properties. Here, we show that the direct exchange of carbon metabolites produced by C. acetobutylicum allows D vulgaris to duplicate its DNA and to be energetically viable even without its substrates. We identify the molecular basis of the physical interactions and how autoinducer-2 (AI-2) molecules control the interactions and metabolite exchanges between C. acetobutylicum and D. vulgaris (or Escherichia coli and D. vulgaris). With nutrients, D. vulgaris produces a small molecule that inhibits in vitro the AI-2 activity and could act as an antagonist in vivo Sensing of AI-2 by D. vulgaris could induce formation of an intercellular structure that allows directly or indirectly metabolic exchange and energetic coupling between the two bacteria.IMPORTANCE Bacteria have usually been studied in single culture in rich media or under specific starvation conditions. However, in nature they coexist with other microorganisms and build an advanced society. The molecular bases of the interactions controlling this society are poorly understood. Use of a synthetic consortium and reducing complexity allow us to shed light on the bacterial communication at the molecular level. This study presents evidence that quorum-sensing molecule AI-2 allows physical and metabolic interactions in the synthetic consortium and provides new insights into the link between metabolism and bacterial communication.
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Affiliation(s)
- David Ranava
- CNRS, Aix-Marseille University, Bioenergetic and Protein Engineering Laboratory, Mediterranean Institute of Microbiology, Marseille, France
| | - Cassandra Backes
- CNRS, Aix-Marseille University, Bioenergetic and Protein Engineering Laboratory, Mediterranean Institute of Microbiology, Marseille, France
| | | | - Olivier Ouari
- Aix-Marseille University, CNRS, UMR 7273, ICR, Marseille, France
| | - Audrey Soric
- Aix-Marseille University, CNRS, Centrale Marseille, M2P2, Marseille, France
| | - Marianne Guiral
- CNRS, Aix-Marseille University, Bioenergetic and Protein Engineering Laboratory, Mediterranean Institute of Microbiology, Marseille, France
| | - María Luz Cárdenas
- CNRS, Aix-Marseille University, Bioenergetic and Protein Engineering Laboratory, Mediterranean Institute of Microbiology, Marseille, France
| | - Marie Thérèse Giudici-Orticoni
- CNRS, Aix-Marseille University, Bioenergetic and Protein Engineering Laboratory, Mediterranean Institute of Microbiology, Marseille, France
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77
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Schiller H, Schulze S, Mutan Z, de Vaulx C, Runcie C, Schwartz J, Rados T, Bisson Filho AW, Pohlschroder M. Haloferax volcanii Immersed Liquid Biofilms Develop Independently of Known Biofilm Machineries and Exhibit Rapid Honeycomb Pattern Formation. mSphere 2020; 5:e00976-20. [PMID: 33328348 PMCID: PMC7771232 DOI: 10.1128/msphere.00976-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 11/19/2020] [Indexed: 12/21/2022] Open
Abstract
The ability to form biofilms is shared by many microorganisms, including archaea. Cells in a biofilm are encased in extracellular polymeric substances that typically include polysaccharides, proteins, and extracellular DNA, conferring protection while providing a structure that allows for optimal nutrient flow. In many bacteria, flagella and evolutionarily conserved type IV pili are required for the formation of biofilms on solid surfaces or floating at the air-liquid interface of liquid media. Similarly, in many archaea it has been demonstrated that type IV pili and, in a subset of these species, archaella are required for biofilm formation on solid surfaces. Additionally, in the model archaeon Haloferax volcanii, chemotaxis and AglB-dependent glycosylation play important roles in this process. H. volcanii also forms immersed biofilms in liquid cultures poured into petri dishes. This study reveals that mutants of this haloarchaeon that interfere with the biosynthesis of type IV pili or archaella, as well as a chemotaxis-targeting transposon and aglB deletion mutants, lack obvious defects in biofilms formed in liquid cultures. Strikingly, we have observed that these liquid-based biofilms are capable of rearrangement into honeycomb-like patterns that rapidly form upon removal of the petri dish lid, a phenomenon that is not dependent on changes in light or oxygen concentration but can be induced by controlled reduction of humidity. Taken together, this study demonstrates that H. volcanii requires novel, unidentified strategies for immersed liquid biofilm formation and also exhibits rapid structural rearrangements.IMPORTANCE This first molecular biological study of archaeal immersed liquid biofilms advances our basic biological understanding of the model archaeon Haloferax volcanii Data gleaned from this study also provide an invaluable foundation for future studies to uncover components required for immersed liquid biofilms in this haloarchaeon and also potentially for liquid biofilm formation in general, which is poorly understood compared to the formation of biofilms on surfaces. Moreover, this first description of rapid honeycomb pattern formation is likely to yield novel insights into the underlying structural architecture of extracellular polymeric substances and cells within immersed liquid biofilms.
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Affiliation(s)
- Heather Schiller
- Department of Biology, Leidy Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Stefan Schulze
- Department of Biology, Leidy Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Zuha Mutan
- Department of Biology, Leidy Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Charlotte de Vaulx
- Department of Biology, Leidy Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Catalina Runcie
- Department of Biology, Leidy Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jessica Schwartz
- Department of Biology, Leidy Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Theopi Rados
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, Massachusetts, USA
| | - Alexandre W Bisson Filho
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, Massachusetts, USA
| | - Mechthild Pohlschroder
- Department of Biology, Leidy Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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78
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Jeon S, Lee JH. Rationally designed in-situ fabrication of thin film nanocomposite membranes with enhanced desalination and anti-biofouling performance. J Memb Sci 2020. [DOI: 10.1016/j.memsci.2020.118542] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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79
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Li K, Qian J, Wang P, Wang C, Lu B, Jin W, He X, Tang S, Zhang C, Gao P. Effects of aging and transformation of anatase and rutile TiO 2 nanoparticles on biological phosphorus removal in sequencing batch reactors and related toxic mechanisms. JOURNAL OF HAZARDOUS MATERIALS 2020; 398:123030. [PMID: 32492616 DOI: 10.1016/j.jhazmat.2020.123030] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 05/22/2020] [Accepted: 05/22/2020] [Indexed: 06/11/2023]
Abstract
The effect of nanomaterials aging, namely the transformation of comprehensive characteristics after experiencing real or complex environmental behaviors, on their ecotoxicology is still lacking. Moreover, the mechanisms by which NPs influence biological phosphorus (P) removal during sewage treatment require further elucidation. Therefore, we used both pristine and aged anatase (TiO2-A) and rutile (TiO2-R) NPs to investigate the mechanisms by which NPs affect P removal in a SBR. At 0.1 mg/L, the four types of NPs (pristine and aged) had no significant effect on sludge purification after acute (72-h) exposure under simulated sunlight. However, at 50 mg/L-regardless of the crystalline phase of the NPs-SOP and COD removal efficiency dropped steeply to approximately 42.2-82.4 % (p < 0.05) and 69.8-83.3 % (p < 0.05), respectively, especially in the pristine TiO2-NPs groups because of decrease of richness and diversity of genus level of PAOs and enzyme activity of both PPK and PPX, and the sluggish transformation of PHA and glycogen. Aging reduced the ability of NPs toxicity. The toxicity mechanisms of TiO2-NPs included lipid peroxidation and contact damage, or leakage from bacterial cytoplasmic membrane, which are closely related to photooxidation capacity and aqueous solution stability-i.e., nanoscale effects-and the impacts of aging or inclusion.
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Affiliation(s)
- Kun Li
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Jin Qian
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China.
| | - Peifang Wang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China.
| | - Chao Wang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Bianhe Lu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Wen Jin
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Xixian He
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Sijing Tang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Chao Zhang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Pan Gao
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
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Diversity of Acyl Homoserine Lactone Molecules in Anaerobic Membrane Bioreactors Treating Sewage at Psychrophilic Temperatures. MEMBRANES 2020; 10:membranes10110320. [PMID: 33143124 PMCID: PMC7693955 DOI: 10.3390/membranes10110320] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 10/23/2020] [Accepted: 10/25/2020] [Indexed: 12/14/2022]
Abstract
This study explores the types of acyl homoserine lactone (AHL) and their concentrations in different compartments of different conventional anaerobic bioreactors: (i) an upflow anaerobic membrane bioreactor (UAnMBR, biofilm/mixed liquor (sludge)); (ii) an anaerobic membrane bioreactor (AnMBR, biofilm/mixed liquor (sludge)); and (iii) an upflow sludge blanket (UASB, sludge only), all operating at 15 °C. Ten types of the AHL, namely C4-HSL, 3-oxo-C4-HSL, C6-HSL, 3-oxo-C6-HSL, C8-HSL, 3-oxo-C8-HSL, C10-HSL, 3-oxo-C10-HSL, C12-HSL, and 3-oxo-C12-HSL, which were investigated in this study, were found in UAnMBR and UASB, whilst only six of them (C4-HSL, 3-oxo-C4-HSL, C8-HSL, C10-HSL, 3-oxo-C10-HSL, and C12-HSL) were found in AnMBR. Concentrations of total AHL were generally higher in the biofilm than the sludge for both membrane bioreactors trialed. C10-HSL was the predominant AHL found in all reactors (biofilm and sludge) followed by C4-HSL and C8-HSL. Overall, the UAnMBR biofilm and sludge had 10-fold higher concentrations of AHL compared to the AnMBR. C10-HSL was only correlated with bacteria (p < 0.05), whilst other types of AHL were correlated with both bacteria and archaea. This study improves our understanding of AHL-mediated Quorum Sensing (QS) in the biofilms/sludge of UAnMBR and AnMBR, and provides new information that could contribute to the development of quorum quenching anti-fouling strategies in such systems.
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81
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Li Q, Gu P, Luo X, Zhang H, Huang S, Zhang J, Zheng Z. Pilot-scale study on the effects of cyanobacterial blooms on Vallisneria natans and biofilms at different phosphorus concentrations. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 265:114996. [PMID: 32593921 DOI: 10.1016/j.envpol.2020.114996] [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: 03/07/2020] [Revised: 06/02/2020] [Accepted: 06/06/2020] [Indexed: 06/11/2023]
Abstract
Cyanobacterial blooms cause potential risk to submerged macrophytes and biofilms in eutrophic environments. This pilot-scale study investigated the growth, oxidative responses, and detoxification activity of aquatic plants in response to cyanobacterial blooms under different phosphorus concentrations. Variations of extracellular polymeric substances (EPSs) and microbial community composition were also assessed. Results showed that the biomass of Vallisneria natans increased with exposure to cyanobacterial blooms at higher phosphorous concentrations (P > 0.2 mg L-1). The amount of microcystin compounds (MC-LR) released into the water and the accumulation of MC-LR into both plant tissue and biofilms changed according to the phosphorus concentration. Furthermore, a certain degree of oxidative stress was induced in the plants, as evidenced by increased activity of superoxide dismutase, catalase, and peroxidase, as well as increased malondialdehyde concentrations; significant differences were also seen in acid phosphatase and glutathione S-transferase activities, as well as in glutathione concentrations. Together, these responses indicate potential mechanisms of MC-LR detoxification. Broader α-D-glucopyranose polysaccharides (PS) increased with increasing phosphorous and aggregated into clusters in biofilm EPS in response to the cyanobacterial blooms. In addition, alterations were seen in the abundance and structure of the microbial communities present in exposed biofilms. These results demonstrate that cyanobacterial blooms under different concentrations of phosphorus can induce differential responses, which can have a significant impact on aquatic ecosystems.
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Affiliation(s)
- Qi Li
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, PR China
| | - Peng Gu
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, PR China
| | - Xin Luo
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, PR China
| | - Hao Zhang
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, PR China
| | - Suzhen Huang
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, PR China
| | - Jibiao Zhang
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, PR China
| | - Zheng Zheng
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, PR China.
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82
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Iron interferes with quorum sensing-mediated cooperation in Pseudomonas aeruginosa by affecting the expression of ppyR and mexT, in addition to rhlR. J Microbiol 2020; 58:938-944. [PMID: 32997304 DOI: 10.1007/s12275-020-0264-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 07/28/2020] [Accepted: 08/03/2020] [Indexed: 10/23/2022]
Abstract
The stabilization of quorum sensing (QS) is vital for bacterial survival in various environments. Although the mechanisms of QS stabilization in certain conditions have been well studied, the impact of environmental factors has received much less attention. In this study, we show that the supplementation of 25 µM iron in competition experiments and 50 µM in evolution experiments to casein growth cultures significantly increased the possibility of population collapse by affecting elastase production. However, the expression of lasI and lasR remained constant regardless of iron concentration and hence this effect was not through interference with the LasIR circuit, which mainly regulates the secretion of elastase in Pseudomonas aeruginosa. However, the expression of rhlR was significantly inhibited by iron treatment, which could affect the production of elastase. Further, based on both reverse transcription quantitative polymerase chain reaction and gene knock-out assays, we show that iron inhibits the transcription of ppyR and enhances the expression of mexT, both of which decrease elastase production and correspondingly interfere with QS stabilization. Our findings show that environmental factors can affect the genes of QS circuits, interfering with QS stabilization. These findings are not only beneficial in understanding the mechanistic effect of iron on QS stabilization, but also demonstrate the complexity of QS stabilization by linking non-QS-related genes with QS traits.
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83
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Zeng YH, Cai ZH, Zhu JM, Du XP, Zhou J. Two hierarchical LuxR-LuxI type quorum sensing systems in Novosphingobium activate microcystin degradation through transcriptional regulation of the mlr pathway. WATER RESEARCH 2020; 183:116092. [PMID: 32622230 DOI: 10.1016/j.watres.2020.116092] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/18/2020] [Accepted: 06/19/2020] [Indexed: 06/11/2023]
Abstract
Microcystins (MCs) are the most common cyanotoxins produced by harmful cyanobacterial blooms and pose an increasing global threat to human health and ecosystems. Microbial degradation represents an efficient and sustainable approach for the removal of MCs. Although the enzymatic pathway for biodegradation of MCs has been characterized, the regulatory mechanisms underlying the degradation processes remain unclear. Quorum sensing (QS) is a cell-density-dependent regulatory mechanism that enables bacteria to orchestrate collective behaviors. The acyl-homoserine lactone (AHL)-mediated QS system regulates the biodegradation of many organic pollutants. However, it is not known whether this QS system is involved in the degradation of MCs. This study aimed to fill this knowledge gap. In this study, the proportion of culturable AHL-producers increased significantly after enrichment of MCs, and AHL-based QS systems were present in all genome-sequenced MC-degrading strains, supporting the hypothesis that QS participates in the degradation of MCs. Two bifunctional Novosphingobium strains (with MC-degrading and AHL-producing abilities) were isolated using a novel primer pair targeting mlrA, the marker gene of mlr degradation pathway. Biochemical and genetic analysis revealed that the MC-degrading bacterium Novosphingobium sp. ERW19 encodes two hierarchical regulatory QS systems designated novR1/novI1 and novR2/novI2. Gene knockout and complementation experiments indicated that both systems were required for efficient degradation of MCs. Transcriptomic analyses revealed that the QS systems positively regulate degradation of MCs through transcriptional activation of MC-degrading genes, especially mlrA. Given that QS may be a common trait within mlr pathway-dependent MC-degrading bacterial strains and the degradation activity is directly regulated by QS, manipulation of the QS systems may be a promising strategy to control biodegradation of MCs.
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Affiliation(s)
- Yan-Hua Zeng
- Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, Guangdong Province, PR China
| | - Zhong-Hua Cai
- Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, Guangdong Province, PR China
| | - Jian-Ming Zhu
- Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, Guangdong Province, PR China
| | - Xiao-Peng Du
- Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, Guangdong Province, PR China
| | - Jin Zhou
- Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, Guangdong Province, PR China.
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Yang J, Feng L, Pi S, Cui D, Ma F, Zhao HP, Li A. A critical review of aerobic denitrification: Insights into the intracellular electron transfer. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 731:139080. [PMID: 32417477 DOI: 10.1016/j.scitotenv.2020.139080] [Citation(s) in RCA: 96] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 04/04/2020] [Accepted: 04/26/2020] [Indexed: 05/23/2023]
Abstract
Aerobic denitrification is a novel biological nitrogen removal technology, which has been widely investigated as an alternative to the conventional denitrification and for its unique advantages. To fully comprehend aerobic denitrification, it is essential to clarify the regulatory mechanisms of intracellular electron transfer during aerobic denitrification. However, reports on intracellular electron transfer during aerobic denitrification are rather limited. Thus, the purpose of this review is to discuss the molecular mechanism of aerobic denitrification from the perspective of electron transfer, by summarizing the advancements in current research on electron transfer based on conventional denitrification. Firstly, the implication of aerobic denitrification is briefly discussed, and the status of current research on aerobic denitrification is summarized. Then, the occurring foundation and significance of aerobic denitrification are discussed based on a brief review of the key components involved in the electron transfer of denitrifying enzymes. Moreover, a strategy for enhancing the efficiency of aerobic denitrification is proposed on the basis of the regulatory mechanisms of denitrification enzymes. Finally, scientific outlooks are given for further investigation on aerobic denitrification in the future. This review could help clarify the mechanism of aerobic denitrification from the perspective of electron transfer.
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Affiliation(s)
- Jixian Yang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, People's Republic of China
| | - Liang Feng
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, People's Republic of China
| | - Shanshan Pi
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, People's Republic of China
| | - Di Cui
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, People's Republic of China; Engineering Research Center for Medicine, College of Pharmacy, Harbin University of Commerce, Harbin 150076, People's Republic of China
| | - Fang Ma
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, People's Republic of China
| | - He-Ping Zhao
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China
| | - Ang Li
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, People's Republic of China.
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85
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Wang Y, Wang H, Wang X, Xiao Y, Zhou Y, Su X, Cai J, Sun F. Resuscitation, isolation and immobilization of bacterial species for efficient textile wastewater treatment: A critical review and update. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 730:139034. [PMID: 32416505 DOI: 10.1016/j.scitotenv.2020.139034] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 04/23/2020] [Accepted: 04/25/2020] [Indexed: 06/11/2023]
Abstract
Given highly complex and recalcitrant nature of synthetic dyes, textile wastewater poses a serious challenge on surrounding environments. Until now, biological treatment of textile wastewater using efficient bacterial species is still considered as an environmentally friendly and cost-effective approach. The advances in resuscitating viable but non-culturable (VBNC) bacteria via signaling compounds such as resuscitation-promoting factors (Rpfs) and quorum sensing (QS) autoinducers, provide a vast majority of potent microbial resources for biological wastewater treatment. So far, textile wastewater treatment from resuscitating and isolating VBNC state bacteria has not been critically reviewed. Thus, this review aims to provide a comprehensive picture of resuscitation, isolation and application of bacterial species with this new strategy, while the recent advances in synthetic dye decolorization were also elaborated together with the mechanisms involved. Discussion was further extended to immobilization methods to tackle its application. We concluded that the resuscitation of VBNC bacteria via signaling compounds, together with biochar-based immobilization technologies, may lead to an appealing biological treatment of textile wastewater. However, further development and optimization of the integrated process are still required for their wide applications.
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Affiliation(s)
- Yuyang Wang
- College of Geography and Environmental Science, Zhejiang Normal University, Jinhua 321004, China
| | - Hangli Wang
- College of Geography and Environmental Science, Zhejiang Normal University, Jinhua 321004, China
| | - Xiaomin Wang
- Zhejiang Environmental Science Research Institute Co., Ltd., Hangzhou 310007, China
| | - Yeyuan Xiao
- Department of Civil and Environmental Engineering, Shantou University, Shantou 515063, China
| | - Yan Zhou
- Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 637141, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, 639798, Singapore
| | - Xiaomei Su
- College of Geography and Environmental Science, Zhejiang Normal University, Jinhua 321004, China
| | - Jiafang Cai
- College of Geography and Environmental Science, Zhejiang Normal University, Jinhua 321004, China
| | - Faqian Sun
- College of Geography and Environmental Science, Zhejiang Normal University, Jinhua 321004, China.
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86
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Xu B, Ng TCA, Huang S, Ng HY. Effect of quorum quenching on EPS and size-fractioned particles and organics in anaerobic membrane bioreactor for domestic wastewater treatment. WATER RESEARCH 2020; 169:115251. [PMID: 32388050 DOI: 10.1016/j.watres.2019.115251] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 10/10/2019] [Accepted: 10/27/2019] [Indexed: 05/06/2023]
Abstract
Quorum quenching (QQ) has been applied as a promising membrane fouling control strategy for anaerobic membrane bioreactors (AnMBRs). Nevertheless, long-term operation of AnMBRs for real domestic wastewater (DWW) treatment needs to be systematically studied to evaluate comprehensive membrane fouling mechanisms and bioprocess performance. In this study, the impact of QQ on membrane fouling was investigated using a quorum quenching AnMBR (QQAnMBR) deploying a bead-entrapped facultative quorum quenching consortium (FQQ) to treat DWW. FQQ was shown to prolong membrane filtration operation by an average of 75%. Reduced proteins (p < 0.005) and carbohydrates (p < 0.005) in the extracellular polymeric substances (EPS) of mixed liquor (ML) were key differentiators that led to lower cake layer (CL) formation. Additionally, reduced biopolymers production (p < 0.05) in EPS improved sludge dewaterability. The findings suggested that QQ could alter fluorescent microbial metabolites of both EPS and CL as unveiled by excitation-emission matrix spectra pattern. Furthermore, colloidal particles (i.e., particles with size larger than 0.45 μm in ML supernatants) production was retarded by QQ, thereafter, also contributed to the reduced CL formation. Pore blockage was slightly increased by QQ, which might be attributed to pore blockage by large (∼230 nm) and small organic compounds (∼51 nm) in soluble microbial products (SMP). However, QQ had no significant impact on organic concentration of SMP, and QQ was not associated with particle size distribution of biomass. QQ performance was further affirmed through suppressed production of C4-HSL, 3-OXO-C6-HSL, and C6-HSL. The overall AHLs degradability of FQQ was well-maintained even after five membrane service cycles (total operation of 70 d). Moreover, QQ had no compromised impact on treatment performance (i.e., chemical oxygen demand (COD) removal and methane yield). Collectively, this study bridged the knowledge gap to bring forward QQ technology in AnMBR for widespread domestic wastewater treatment application.
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Affiliation(s)
- Boyan Xu
- Centre for Water Research, Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, 117576, Singapore
| | - Tze Chiang Albert Ng
- Centre for Water Research, Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, 117576, Singapore
| | - Shujuan Huang
- Centre for Water Research, Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, 117576, Singapore
| | - How Yong Ng
- Centre for Water Research, Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, 117576, Singapore; National University of Singapore Environmental Research Institute, 5A Engineering Drive 1, 117411, Singapore.
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87
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Li Q, Gu P, Zhang C, Luo X, Zhang H, Zhang J, Zheng Z. Combined toxic effects of anatoxin-a and microcystin-LR on submerged macrophytes and biofilms. JOURNAL OF HAZARDOUS MATERIALS 2020; 389:122053. [PMID: 31978825 DOI: 10.1016/j.jhazmat.2020.122053] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 01/07/2020] [Accepted: 01/07/2020] [Indexed: 06/10/2023]
Abstract
Hazardous substances, such as anatoxin-a and microcystin-LR, are released into the aquatic environment during cyanobacterial blooms, causing significant ecological risk. To assess the toxic effects of anatoxin-a, microcystin-LR and their combined exposure on submerged macrophytes and biofilms, Vallisneria natans was exposed to solutions containing different concentrations of anatoxin-a and microcystin-LR (0.05-5.00 μg L-1). Results showed that Vallisneria natans was sensitive to anatoxin-a of 0.05 μg L-1, and antagonistic effects were induced at combined microcystin-LR and anatoxin-a exposure. Single and combined exposure effectively induced antioxidant responses such as promoted activities of superoxide dismutase, peroxidase and catalase, as well as increased glutathione S-transferase, glutathione and malondialdehyde content. In addition, anatoxin-a and microcystin-LR could also be absorbed by Vallisneria natans and trigger plant defense responses, generating increased concentrations of the phytohormones abscisic acid and strigolactones. Moreover, the abundances and structure of the microbial community in periphyton biofilms were altered by combined anatoxin-a and microcystin-LR exposure. The enhanced concentration of N-acylated-l-homoserine lactone indicated that the assessed cyanotoxins had a significant influence on quorum-sensing in biofilm microbial communities. These results demonstrated that anatoxin-a and microcystin-LR at environmentally relevant concentrations could disrupt homeostasis, induce effective defense mechanisms of Vallisneria natans and alter biofilms in aquatic ecosystems.
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Affiliation(s)
- Qi Li
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China
| | - Peng Gu
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China
| | - Chen Zhang
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China
| | - Xin Luo
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China
| | - Hao Zhang
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China
| | - Jibiao Zhang
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China.
| | - Zheng Zheng
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China.
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88
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Waheed H, Xiao Y, Hashmi I, Zhou Y. The selective pressure of quorum quenching on microbial communities in membrane bioreactors. CHEMOSPHERE 2020; 247:125953. [PMID: 32069724 DOI: 10.1016/j.chemosphere.2020.125953] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 11/30/2019] [Accepted: 01/17/2020] [Indexed: 06/10/2023]
Abstract
In conventional membrane bioreactor (MBR) treatment systems, Gram-negative bacterial population appears to be always outnumbered Gram-positive community. Thereby, acyl homoserine lactones (AHLs), major signaling molecules utilized by Gram-negative bacteria, have been targeted for biofouling control in quorum quenching (QQ) based studies. This study investigated the impact of AHL and autoinducer-2 (AI-2)-degrading QQ consortium on the selective accumulation of microbial communities in a QQ MBR (MBR-QQb). The results show that addition of the QQ consortium (in the form of beads) increased the filtration time of MBR-QQb by 3.5 times. The distribution of mixed liquor extracellular polymeric substances (EPS), especially the tightly bound (TB) proteinous EPS and the floc size were strongly affected by the QQ activity, and the endless 'battle' between QQ and quorum sensing (QS). More importantly, QQ induced the significant suppression of Gram-negative bacterial community. The average abundance of Gram-positive bacteria at the genus level in the biocake of MBR-QQb (51%) was significantly higher than that of the control MBR (11%) and the MBR with vacant beads (28%). These findings suggest that an unintended condition is created to favor the growth of Gram-positive bacteria in QQ MBRs, resulting in a distinct microbial social network in both bulk sludge and biocake.
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Affiliation(s)
- Hira Waheed
- Department of Civil and Environmental Engineering, Shantou University, Guangdong, 515063, China; Institute of Environmental Sciences and Engineering, School of Civil and Environmental Engineering, National University of Sciences and Technology, H-12 Sector, Islamabad, Pakistan; Advanced Environmental Biotechnology Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
| | - Yeyuan Xiao
- Department of Civil and Environmental Engineering, Shantou University, Guangdong, 515063, China; Advanced Environmental Biotechnology Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, Singapore, 639798, Singapore.
| | - Imran Hashmi
- Institute of Environmental Sciences and Engineering, School of Civil and Environmental Engineering, National University of Sciences and Technology, H-12 Sector, Islamabad, Pakistan.
| | - Yan Zhou
- Advanced Environmental Biotechnology Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, Singapore, 639798, Singapore.
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89
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Cui B, Yang Q, Liu X, Wu W, Liu Z, Gu P. Achieving partial denitrification-anammox in biofilter for advanced wastewater treatment. ENVIRONMENT INTERNATIONAL 2020; 138:105612. [PMID: 32155511 DOI: 10.1016/j.envint.2020.105612] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/09/2020] [Accepted: 02/25/2020] [Indexed: 05/14/2023]
Abstract
Recently, partial denitrification (PDN) - anaerobic ammonium oxidation (anammox) process has been widely studied in activated sludge for nitrate wastewater treatment. However, achieving PDN-Anammox in biofilter for domestic wastewater treatment was never reported. In this study, two lab-scale PDN biofilter and Anammox biofilter were built up to treat simulated domestic wastewater. The results showed that stable nitrogen removal performance was kept with averaged effluent nitrogen of 10.2 mg/L. Stable nitrite accumulation performance was achieved with low abundance of nitrite reductase gene, while influent composition influenced nitrogen transformation pathway in PDN biofilter. When treating domestic wastewater, nitrification and partial denitrification led to the higher nitrite accumulation ratio of 75.4%. The percentage contribution of anammox biofilter was 74.6% for nitrogen removal, and Candidatus Brocadia was dominant genus. After long-term operation, limited substrate concentration caused interspecific competition among various anammox bacteria, leading to an increasing proportion of Candidatus Brocadia fulgida. PDN-Anammox biofilter is a feasible process to advanced wastewater treatment, which could save aeration consumption and carbon source addition, and reduce sludge production.
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Affiliation(s)
- Bin Cui
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, PR China
| | - Qing Yang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, PR China.
| | - Xiuhong Liu
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, PR China
| | - Wenjun Wu
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, PR China
| | - Zhibin Liu
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, PR China
| | - Pengchao Gu
- Beijing Drainage Grp Co. Ltd BDG, Beijing 100022, PR China
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90
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Yin Q, Gu M, Hermanowicz SW, Hu H, Wu G. Potential interactions between syntrophic bacteria and methanogens via type IV pili and quorum-sensing systems. ENVIRONMENT INTERNATIONAL 2020; 138:105650. [PMID: 32182450 DOI: 10.1016/j.envint.2020.105650] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 03/04/2020] [Accepted: 03/09/2020] [Indexed: 06/10/2023]
Abstract
Interspecies electron transfer plays an important role in syntrophic methanogenesis. Direct interspecies electron transfer (DIET) between syntrophic oxidizers and methanogens via conductive pili has been only confirmed in some specific co-cultures. This study examined potential syntrophic cooperation via type IV pili and quorum sensing between widespread syntrophic bacteria and methanogens through a metagenomic analysis of 12 anaerobic sludge samples. We found that Methanosaeta and Methanosarcina, which are reported to have DIET ability, were dominant in most methanogenic samples. Putative conductive pili genes were found in some typical syntrophic bacteria, which has rarely been reported previously. The existence of diverse quorum-sensing genes suggested that various quorum-sensing systems might participate in the communication of anaerobic microorganisms. Specifically, the diffusible signal factor and 3'-5' cyclic diguanosine monophosphate related genes were mainly assigned to syntrophic bacteria. These results suggest that the combined regulation of these signals might be responsible for the biosynthesis of type IV pili and affect syntrophic interaction during methanogenesis. These novel results provide fresh evidence to support the widespread existence of DIET in anaerobic methanogenic systems; therefore, regulating the quorum-sensing system may promote syntrophic interaction.
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Affiliation(s)
- Qidong Yin
- Shenzhen Environmental Science and New Energy Technology Engineering Laboratory, Tsinghua-Berkeley Shenzhen Institute, Shenzhen 518055, Guangdong, China
| | - Mengqi Gu
- Key Laboratory of Microorganism Application and Risk Control (MARC) of Shenzhen, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, Guangdong, China
| | - Slawomir W Hermanowicz
- Shenzhen Environmental Science and New Energy Technology Engineering Laboratory, Tsinghua-Berkeley Shenzhen Institute, Shenzhen 518055, Guangdong, China; Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720, USA
| | - Hongying Hu
- Shenzhen Environmental Science and New Energy Technology Engineering Laboratory, Tsinghua-Berkeley Shenzhen Institute, Shenzhen 518055, Guangdong, China
| | - Guangxue Wu
- Key Laboratory of Microorganism Application and Risk Control (MARC) of Shenzhen, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, Guangdong, China.
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91
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Feng X, Guo W, Zheng H, Yang S, Du J, Wu Q, Luo H, Zhou X, Jin W, Ren N. Inhibition of biofouling in membrane bioreactor by metabolic uncoupler based on controlling microorganisms accumulation and quorum sensing signals secretion. CHEMOSPHERE 2020; 245:125363. [PMID: 31877457 DOI: 10.1016/j.chemosphere.2019.125363] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Revised: 11/10/2019] [Accepted: 11/12/2019] [Indexed: 06/10/2023]
Abstract
Biofouling is a limiting bottleneck in the development of membrane bioreactor (MBR) since the birth of this technology. Recently, the biofouling control strategy based on interfering with the bacterial quorum sensing (QS) system is highly desirable for biofouling control in MBR. In this study, three lab-scale parallel MBR systems were operated over 100 days to investigate the inhibitory effect of a metabolic uncoupler (3,3',4',5-tetrachlorosalicylanilide, TCS) on biofouling and the potential mechanism for biofouling control. Compared to the control MBR, the fouling cycle duration of MBR 2 with 100 μg/L TCS extended over two times. The attached biomass on membrane in MBR 2 decreased over 50% at the end of each operating period, which indicated that the addition of TCS significantly mitigated microorganisms accumulation on membrane. The content of interspecies QS signal (autoinducer-2) and intraspecific QS signals (N-octanoyl-dl-homoserine lactone, C8-HSL) was reduced by the TCS, suggesting the secretion of QS signals in MBR were affected by uncoupler. Although the addition of TCS induced brief fluctuations of extracellular proteins and polysaccharides, microorganisms seemed to rapidly acclimatize to the presence of TCS and then the secretion of extracellular polymeric substances (EPS) was inhibited by 100 μg/L TCS. The continuous operation of MBR was not be affected by the low-concentration uncoupler via the analysis of substrate removal and sludge growth. This study systematically evaluated the effect and inhibitory efficiency of TCS on biofouling, biomass accumulation, QS signals, EPS and treatment performances, demonstrating the feasibility of metabolic uncoupler for biofouling control in MBR.
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Affiliation(s)
- Xiaochi Feng
- School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, Guangdong, 518055, PR China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, PR China
| | - Wanqian Guo
- School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, Guangdong, 518055, PR China.
| | - Heshan Zheng
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar, 161006, China
| | - Shanshan Yang
- School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, Guangdong, 518055, PR China
| | - Juanshan Du
- School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, Guangdong, 518055, PR China
| | - Qinglian Wu
- School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, Guangdong, 518055, PR China
| | - Haichao Luo
- School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, Guangdong, 518055, PR China
| | - Xu Zhou
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, PR China
| | - Wenbiao Jin
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, PR China
| | - Nanqi Ren
- School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, Guangdong, 518055, PR China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, PR China.
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92
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Li S, Li D, Wang Y, Zeng H, Yuan Y, Zhang J. Startup and stable operation of advanced continuous flow reactor and the changes of microbial communities in aerobic granular sludge. CHEMOSPHERE 2020; 243:125434. [PMID: 31995884 DOI: 10.1016/j.chemosphere.2019.125434] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 11/07/2019] [Accepted: 11/20/2019] [Indexed: 05/20/2023]
Abstract
In this study, the granular sludge was operated under low aeration condition in sequencing batch reactor (SBR) and advanced continuous flow reactor (ACFR), respectively. Through increasing the sludge retention time (SRT) from 22 days to 33 days, the ACFR was successful startup in 30 days and achieved long term stable operation. Under SBR operation condition, the aerobic granular sludge (AGS) showed good nitrogen (60%), phosphorus (96%) and COD removal performance. During stable operation of continuous-flow, the nitrogen removal efficiency was increasing to 70%, however, the phosphorus removal efficiency could only be restored to 65%. Meanwhile, the sludge discharge volume from ACFR was about half of that in SBR. Results of high-throughput pyrosequencing illustrated that methanogenic archaea (MA), ammonia oxidizing archaea (AOA), denitrifying bacteria (DNB), denitrifying polyphosphate-accumulating organisms (DPAOs) played an important role in the removal of nutrients in ACFR. This study could have positive effect on the practical application of AGS continuous flow process for simultaneous biological nutrient removal (SBNR).
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Affiliation(s)
- Shuai Li
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China.
| | - Dong Li
- Key Laboratory of Water Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing, 100123, China.
| | - Yingqiao Wang
- Key Laboratory of Water Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing, 100123, China.
| | - Huiping Zeng
- Key Laboratory of Water Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing, 100123, China.
| | - Yixing Yuan
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China.
| | - Jie Zhang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China; Key Laboratory of Water Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing, 100123, China.
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93
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Liu L, Ji M, Wang F, Tian Z, Wang T, Wang S, Wang S, Yan Z. Insight into the short-term effect of fulvic acid on nitrogen removal performance and N-acylated- L-homoserine lactones (AHLs) release in the anammox system. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 704:135285. [PMID: 31822421 DOI: 10.1016/j.scitotenv.2019.135285] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 10/09/2019] [Accepted: 10/28/2019] [Indexed: 05/06/2023]
Abstract
Fulvic acid (FA) can serve as electron shuttles between bacteria and electron acceptors. It explored the short-term effect of FA dose on nitrogen removal performance and N-acylated-L-homoserine lactones (AHLs) release change in the anaerobic ammonium oxidation (anammox) system. The results demonstrated that the total inorganic nitrogen removal efficiency increased with the FA dosages from 0.5 mM to 1 mM. FA addition improved anammox bacteria activity, together with extracellular polymeric substances production. FA addition from 0.5 mM to 1 mM stimulated AHLs release in both water and biomass phases, which indicated that the quorum sensing could be improved. These findings revealed that the addition of FA could improve quorum sensing and then enhance nitrogen removal performance.
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Affiliation(s)
- Lingjie Liu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, PR China
| | - Min Ji
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, PR China
| | - Fen Wang
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, PR China.
| | - Zhongke Tian
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, PR China
| | - Tianyi Wang
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, PR China
| | - Shuya Wang
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, PR China
| | - Siyu Wang
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, PR China
| | - Zhao Yan
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, PR China
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94
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Li K, Qian J, Wang P, Wang C, Lu B, Tian X, Jin W, He X, Chen H, Zhang Y, Liu Y. Differential responses of encoding-amoA nitrifiers and nir denitrifiers in activated sludge to anatase and rutile TiO 2 nanoparticles: What is active functional guild in rate limiting step of nitrogen cycle? JOURNAL OF HAZARDOUS MATERIALS 2020; 384:121388. [PMID: 31668758 DOI: 10.1016/j.jhazmat.2019.121388] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 09/26/2019] [Accepted: 10/02/2019] [Indexed: 06/10/2023]
Abstract
The long-terms effects of different crystal-composition TiO2 nanoparticles (NPs) on nitrogen-cycle-related functional guilds in activated sludge remain unclear, especially under natural light irradiation. Accordingly, activated sludge was exposed to anatase TiO2-NPs (TiO2-A) and rutile TiO2-NPs (TiO2-R) for up to 45 days. With markedly (p < 0.05) reducing nitrification-/denitrification-enzymatic-activities and abundances of ammonia-oxidizing-microorganisms (AOMs) and nitrite-reducing-bacteria (NRB), TiO2-NPs triggered bacteria and archaea UPGMA clustering and a deep modification of N-cycling functional diversity guided by crystal structure. in situ13C-DNA-SIP confirmed ammonia-oxidizing-bacteria (AOB) (Nitrosomonas and Nitrosospira) in original sludge as main active AOMs with 75.4 times more abundance than ammonia-oxidizing-archaea (AOA), while AOA within Nitrosopumilus and Nitrososphaera genera were the main active AOMs and tended to aggregate inside sludge after 10-mg/L TiO2-NPs exposure. Encoding-nirK NRB were more sensitive, while encoding-nirS Zoogloea with a total share of 4.97% to 14.93%, etc. were the main active NRB. AOB was more sensitive to TiO2-A, while TiO2-R showed the stronger toxicity to AOA and NRB resulting from differences in water environmental behaviors and crystal characteristics of two TiO2-NPs. This work expands understanding of the ecological risks of titanium-dioxide-crystal-NPs in aquatic environment and may help devise better methods to alleviate environmental stress caused by NPs at wastewater treatment plants.
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Affiliation(s)
- Kun Li
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Jin Qian
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China.
| | - Peifang Wang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China.
| | - Chao Wang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Bianhe Lu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Xin Tian
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Wen Jin
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Xixian He
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Hao Chen
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Yuhang Zhang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Yin Liu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
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95
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Wang J, Liu Q, Li X, Ma S, Hu H, Wu B, Zhang XX, Ren H. In-situ monitoring AHL-mediated quorum-sensing regulation of the initial phase of wastewater biofilm formation. ENVIRONMENT INTERNATIONAL 2020; 135:105326. [PMID: 31794939 DOI: 10.1016/j.envint.2019.105326] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Revised: 10/05/2019] [Accepted: 11/11/2019] [Indexed: 06/10/2023]
Abstract
Initial attachment plays an important role in biofilm formation in wastewater treatment processes. However, the initial attachment process mediated by N-acyl-homoserine lactones (AHLs) is difficult to be fully understood due to the lack of non-invasive and on-line investigation techniques. In this study, the AHL-regulated wastewater biofilm attachment was quantified using ultrasonic time-domain reflectometry (UTDR) as an in-situ and non-invasive monitoring technique. Results demonstrated that the reversible adhesion time in municipal and industrial wastewaters was significantly decreased in the presence of exogenous AHLs. Biofilm thickness in municipal and industrial wastewaters increased significantly with the addition of exogenous AHLs. Also, the addition of acylase delayed the initial biofilm formation (lengthened reversible adhesion time and decreased biofilm thickness and density). Compared with biofilm behavior in the presence of low concentrations of AHLs (4.92 ± 0.17 μg/L), both reversible adhesion time and biofilm thickness were not significantly increased (p > 0.05) with an increase in AHL concentration (9.75 ± 0.41 μg/L). Furthermore, the addition of exogenous AHLs resulted in significant changes in the attached bacterial community structures, in which both QS and quorum-quenching (QQ) bacteria were stimulated. The current work presents an effective approach to in-situ monitoring of the regulation of AHL-mediated QS in the initial attachment of biofilms, especially in the reversible adhesion process, which may provide a potential strategy to facilitate biofilm establishment in wastewater treatment processes.
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Affiliation(s)
- Jinfeng Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Qiuju Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Xianhui Li
- Department of Civil Engineering, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Sijia Ma
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Haidong Hu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Bing Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Xu-Xiang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, China.
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96
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Li Q, Gu P, Zhang H, Luo X, Zhang J, Zheng Z. Response of submerged macrophytes and leaf biofilms to the decline phase of Microcystis aeruginosa: Antioxidant response, ultrastructure, microbial properties, and potential mechanism. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 699:134325. [PMID: 31678882 DOI: 10.1016/j.scitotenv.2019.134325] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 09/02/2019] [Accepted: 09/05/2019] [Indexed: 06/10/2023]
Abstract
Decaying cyanobacterial blooms carry a potential risk for submerged macrophyte and periphyton biofilms in aquatic environments. This study comprehensively studied the responses in growth, oxidative response, detoxification pathway, and ultrastructure characteristics of aquatic plants to Microcystis aeruginosa (M. aeruginosa) exudates and extracts released during the decline phase. Particular emphasis was placed on the variation of extracellular polymeric substances (EPS) and quorum-sensing signaling molecules. The results showed that superoxide dismutase, peroxidase, and glutathione S-transferase were significantly induced as antioxidant response, and the malondialdehyde content increased. Increased content of MC-LR (1.129 μg L-1) and NH4+-N (1.35 mg L-1) were found in the decline phase of M. aeruginosa, which played a vital role in the damage to submerged plants. In addition, a change in the amount of osmiophilic granules and a variation of organelles and membranes was observed. A broad distribution of α-d-glucopyranose polysaccharides was dominant and aggregated into clusters in biofilm EPS in response to exposure to decaying M. aeruginosa. Furthermore, exposure to exudates and extracts changed the abundance and structure of the microbial biofilm community. Increased contents of N-acylated-L-homoserine lactone signal molecule might result in a variation of biofilm EPS production in response to decaying M. aeruginosa. These results expand the understanding of how submerged macrophyte and periphyton biofilms respond to environmental stress caused by exudates and extracts of decaying M. aeruginosa.
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Affiliation(s)
- Qi Li
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China
| | - Peng Gu
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China
| | - Hao Zhang
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China
| | - Xin Luo
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China
| | - Jibiao Zhang
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China.
| | - Zheng Zheng
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China.
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97
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Zhu L, Chen T, Xu L, Zhou Z, Feng W, Liu Y, Chen H. Effect and mechanism of quorum sensing on horizontal transfer of multidrug plasmid RP4 in BAC biofilm. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 698:134236. [PMID: 31493577 DOI: 10.1016/j.scitotenv.2019.134236] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 08/28/2019] [Accepted: 08/31/2019] [Indexed: 06/10/2023]
Abstract
The widespread emergence of antibiotic resistance genes (ARGs) in drinking water systems endangers human health, and may be exacerbated by their horizontal gene transfer (HGT) among microbiota. In our previous study, Quorum sensing (QS) molecules produced by bacteria from biological activated carbon (BAC) biofilms were demonstrated to influence the transfer efficiency of a model conjugative plasmid, here RP4. In this study, we further explored the effect and mechanism of QS on conjugation transfer. The results revealed that Acyl-homoserine lactones producing (AHL-producing) bacteria isolated from BAC biofilm play a role in the propagation of ARGs. We selected several quorum sensing inhibitors (QSIs) to study their effects on AHL-producing bacteria, including the formation of biofilm and the regulating effect on conjugation transfer. In addition, the possible molecular mechanisms for AHLs that promote conjugative transfer were attributable to enhancing the mRNA expression, which involved altered expressions of conjugation-related genes. We also found that QSIs could inhibit conjugative transfer by downregulating the conjugation-relevant genes. We believe that this is the first insightful exploration of the mechanism by which AHLs will facilitate and QSIs will inhibit the conjugative transfer of ARGs. These results provide creative insight into ARG pollution control that involves blocking QS during BAC treatment in drinking water systems.
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Affiliation(s)
- Lin Zhu
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Tao Chen
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Lan Xu
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Zhenchao Zhou
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Wanqiu Feng
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yang Liu
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Hong Chen
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
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98
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Mathews ER, Wood JL, Phillips D, Billington N, Barnett D, Franks AE. Town-scale microbial sewer community and H 2S emissions response to common chemical and biological dosing treatments. J Environ Sci (China) 2020; 87:133-148. [PMID: 31791487 DOI: 10.1016/j.jes.2019.06.011] [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: 03/04/2019] [Revised: 06/15/2019] [Accepted: 06/17/2019] [Indexed: 06/10/2023]
Abstract
Controlling hydrogen sulfide (H2S) odors and emissions using a single, effective treatment across a town-scale sewer network is a challenge faced by many water utilities. Implementation of a sewer diversion provided the opportunity to compare the effectiveness of magnesium hydroxide (Mg(OH)2) and two biological dosing compounds (Bioproducts A and B), with different modes of action (MOA), in a field-test across a large sewer network. Mg(OH)2 increases sewer pH allowing suppression of H2S release into the sewer environment while Bioproduct A acts to disrupt microbial communication through quorum sensing (QS), reducing biofilm integrity. Bioproduct B reduces H2S odors by scouring the sewer of fats, oils and grease (FOGs), which provide adhesion points for the microbial biofilm. Results revealed that only Mg(OH)2 altered the microbial community structure and reduced H2S emissions in a live sewer system, whilst Bioproducts A and B did not reduce H2S emissions or have an observable effect on the composition of the microbial community at the dosed site. Study results recommend in situ testing of dosing treatments before implementation across an operational system.
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Affiliation(s)
- Elizabeth R Mathews
- Department of Physiology, Anatomy and Microbiology, La Trobe University, Melbourne, Australia
| | - Jennifer L Wood
- Department of Physiology, Anatomy and Microbiology, La Trobe University, Melbourne, Australia; Centre for Future Landscapes, La Trobe University, Melbourne, Australia; Faculty of Science, Engineering and Technology, Swinburne University of Technology, Melbourne, Australia
| | | | | | | | - Ashley E Franks
- Department of Physiology, Anatomy and Microbiology, La Trobe University, Melbourne, Australia; Centre for Future Landscapes, La Trobe University, Melbourne, Australia.
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99
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Gao M, Liu YJ, Liu Z, Li HT, Zhang AN. Dynamic characteristics of AHLs-secreting strain Aeromonas sp. A-L2 and its bioaugmentation during quinoline biodegradation. J Appl Microbiol 2019; 128:1060-1073. [PMID: 31770483 DOI: 10.1111/jam.14530] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 10/31/2019] [Accepted: 11/21/2019] [Indexed: 11/29/2022]
Abstract
AIMS In order to probe a more environmentally friendly method of pollutant treatment based on microbial bioaugmentation and quorum sensing (QS) effects. METHODS AND RESULTS The dynamic characteristics and QS effects of the acylated homoserine lactones (AHLs)-secreting strain Aeromonas sp. A-L2 (A-L2), which was isolated from the activated sludge system, was discussed. According to the liquid chromatography-mass spectrometry results, N-butyryl-homoserine lactone (C4-HSL) and N-hexanoyl-homoserine lactone (C6-HSL) were the major AHLs secreted by strain A-L2, and the swarming of strain Ochrobactrum sp. LC-1 (LC-1) was induced by these compounds. The extracellular polymeric substance secretion of the strain LC-1 was mainly led by C6-HSL, and the biofilm formation ability was mainly influenced by C6-HSL or C4-HSL (60 μg l-1 ). The optimal AHLs secretion conditions of strain A-L2 were also studied. Drawing support from the AHLs-secreting strain A-L2 during quinoline degradation by strain LC-1, the degradation time was greatly shortened. CONCLUSIONS Hence, AHLs-secreting strain A-L2 can be useful as an AHLs continuous supplier during bioaugmentation and pollutant biodegradation. SIGNIFICANCE AND IMPACT OF THE STUDY The bioaugmentation process of strain A-L2 on quinoline biodegradation based on QS effects would lay a certain theoretical and practical significance for large-scale applications.
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Affiliation(s)
- M Gao
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, PR China
| | - Y J Liu
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, PR China.,Key Lab of Northwest Water Resource, Ecology and Environment, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an, PR China
| | - Z Liu
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, PR China.,Key Lab of Northwest Water Resource, Ecology and Environment, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an, PR China
| | - H T Li
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, PR China
| | - A N Zhang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, PR China.,Key Lab of Northwest Water Resource, Ecology and Environment, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an, PR China
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100
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Fan X, Peng P, Huang H, Peng C, Gao Y, Ren H. Undesirable effects of exogenous N-acyl homoserine lactones on moving bed biofilm reactor treating medium-strength synthetic wastewater. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 696:134061. [PMID: 31465921 DOI: 10.1016/j.scitotenv.2019.134061] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/21/2019] [Accepted: 08/21/2019] [Indexed: 06/10/2023]
Abstract
Exogenous AHLs are gradually reported to facilitate biofilm growth, however, whether they play a universal role in promoting biofilm formation and pollutants removal remains to be investigated. The pollutant removal, biofilm properties, microbial community and the distribution of AHLs were investigated in three lab-scale MBBRs by continuous dosing 100 nM N-Hexanoyl-L-homoserine lactone (C6-HSL) and N-Octanoyl-L-homoserine lactone (C8-HSL) in synthetic wastewater under normal nutrition (40 mg/L NH4+-N with C/N = 20). Results showed that adding AHLs didn't affect organics removal and exogenous C6-HSL even significantly suppressed NH4+-N removal by 0.44-20.29% after 16 days (p < 0.05). The introduction of AHLs both facilitated biofilm growth and extracellular polymeric substances secretion while suppressed ATP production especially during the stable operation period, with 48.96% by C6-HSL (p < 0.05) and 27.25% by C8-HSL, respectively. Exogenous AHLs inhibited the proliferation of Chryseobacterium, resulting in improvement in biofilm growth and it probably mediated ATP synthesis through regulating the release of 3OHC12-HSL in aqueous phase. Organics removal and biofilm growth were mainly attributed to the combined actions of multitudinous AHLs in biofilm phase rather than that in aqueous phase. The counterintuitive conclusions obtained in this study highlighted the importance of legitimately applying exogenous AHLs to accelerate biofilm formation and the start-up of MBBR in wastewater treatment.
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Affiliation(s)
- Xuan Fan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Pengcheng Peng
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Hui Huang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China.
| | - Chong Peng
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Yilin Gao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
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