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Pechaud Y, Derlon N, Queinnec I, Bessiere Y, Paul E. Modelling biofilm development: The importance of considering the link between EPS distribution, detachment mechanisms and physical properties. WATER RESEARCH 2024; 250:120985. [PMID: 38118257 DOI: 10.1016/j.watres.2023.120985] [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: 09/10/2023] [Revised: 12/02/2023] [Accepted: 12/06/2023] [Indexed: 12/22/2023]
Abstract
In industry, treatments against biofilms need to be optimized and, in the wastewater treatment field, biofilm composition needs to be controlled. Therefore, describing the biochemical and physical structures of biofilms is now required to better understand the influence of operating parameters and treatment on biofilms. The present study aims to investigate how growth conditions influence EPS composition, biofilm physical properties and volume detachment using a 1D biofilm model. Two types of EPS are considered in the present model, proteins and polysaccharides. The main hypotheses are that: (i) the production of polysaccharides occurs mainly under strong nutrient limitation(s) while the production of proteins is coupled to both the substrate uptake rate and the lysis process; (ii) the local biofilm porosity depends on the local biofilm composition. Both volume and surface detachment occur in biofilms and volume detachment extent depends on the biofilm local cohesion and thus on the local composition of biofilms for a given shear stress. The model is based on experimental trends and aims to represent these observations on the basis of biochemical and physical processes. Four case studies covering a wide range of contrasting growth conditions such as different COD/N ratios, applied SOLR and shear stresses are investigated. The model predicts how the biochemical and physical biofilm structures change as a result of contrasting growth conditions. More precisely simulation results are in good agreement with the main experimental observations reported in the literature, such as: (i) a strong nitrogen limitation of growth induces an important accumulation of polysaccharides leading to a more porous and homogenous biofilm, (ii) a high applied surface organic loading load allows to obtain a high biofilm thickness, (iii) a strong shear stress applied during the biofilm growth leads to a reduction of the biofilm thickness and to a consolidation of the biofilm structure. Overall, this model represents a relevant decision tool for the selection of appropriate enzymatic treatments in the context of negative biofilm control. From our results, it appears that protease based treatments should be more appropriate for biofilms developed under low COD/N ratios (about 20 gCOD/gN) whereas both glucosidases and proteases based treatments should be more appropriate for biofilms developed under high COD/N ratio (about 70 gCOD/gN). In addition, the model could be useful for other applications such as resource recovery in biofilms or granules, and help to better understand biological membrane fouling.
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Affiliation(s)
- Y Pechaud
- TBI, CNRS, INRAE, INSA, Université de Toulouse, 35 avenue de Rangueil, Toulouse 31077, France; Laboratoire Géomatériaux et Environnement (EA 4508), Université Gustave Eiffel, Marne-la-Vallée 77454, France.
| | - N Derlon
- EAWAG, Ueberlandstrasse 133, P.O Box 611, Dübendorf 8600, Switzerland
| | - I Queinnec
- CNRS, LAAS, 7 avenue du Colonel Roche, Toulouse F-31400, France
| | - Y Bessiere
- TBI, CNRS, INRAE, INSA, Université de Toulouse, 35 avenue de Rangueil, Toulouse 31077, France
| | - E Paul
- TBI, CNRS, INRAE, INSA, Université de Toulouse, 35 avenue de Rangueil, Toulouse 31077, France.
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2
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Tong CY, Lim SL, Chua MX, Derek CJC. Uncovering the role of algal organic matter biocoating on Navicula incerta cell deposition and biofilm formation. Bioengineered 2023; 14:2252213. [PMID: 37695682 PMCID: PMC10496527 DOI: 10.1080/21655979.2023.2252213] [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: 03/16/2023] [Revised: 05/23/2023] [Accepted: 06/01/2023] [Indexed: 09/13/2023] Open
Abstract
Spontaneous natural biofilm concentrates microalgal biomass on solid supports. However, the biofilm is frequently susceptible to exfoliation upon nutrient deficiency, particularly found in aged biofilm. Therefore, this study highlights a novel biofilm cultivation technique by pre-depositing the algal organic matters from marine diatom, Navicula incerta onto microporous polyvinylidene fluoride membrane to further strengthen the biofilm developed. Due to the improvement in membrane surface roughness and hydrophobicity, cells adhered most abundantly to soluble extrapolymeric substances-coated (sEPS) (76× 106± 16× 106 cells m-2), followed by bounded EPS-coated (57.67× 106± 0.33× 106 cells m-2), internally organic matter (IOM)-coated (39.00× 106± 5.19× 106 cells m-2), and pristine control the least (6.22× 106± 0.77× 106 cells m-2) at 24th h. Surprisingly, only bEPS-coated membrane demonstrated an increase in cell adhesion toward the end of the experiment at 72 h. The application of the bio-coating has successfully increased the rate of cell attachment by at least 45.3% upon inoculation and achieved as high as 89.9% faster attachment at 72 hours compared to the pristine control group. Soluble polysaccharides and proteins might be carried along by the cells adhering onto membranes hence resulting in a built up of EPS hydrophobicity (>70% in average on bio-coated membranes) over time as compared with pristine (control) that only recorded an average of approximately 50% hydrophobicity. Interestingly, cells grown on bio-coated membranes accumulated more internally bounded polysaccharides, though bio-coating had no discernible impact on the production of both externally and internally bounded protein. The collective findings of this study reveal the physiological alterations of microalgal biofilms cultured on bio-coated membranes.
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Affiliation(s)
- C. Y. Tong
- School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, Nibong Tebal, Penang, Malaysia
| | - Siew Li Lim
- School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, Nibong Tebal, Penang, Malaysia
| | - Mei Xia Chua
- School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, Nibong Tebal, Penang, Malaysia
| | - C. J. C. Derek
- School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, Nibong Tebal, Penang, Malaysia
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Yu L, Zhang Q, Li R, Qiao B, Wang Z, Zheng L, Peng D. Extracellular polymeric substances trigger microbial immigration from partial denitrification (PD) to anammox biofilms in a long-term operated PD/anammox process in low-strength wastewater. WATER RESEARCH 2023; 229:119382. [PMID: 36446177 DOI: 10.1016/j.watres.2022.119382] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 10/04/2022] [Accepted: 11/17/2022] [Indexed: 06/16/2023]
Abstract
The immigration of microbial communities in a synergistic partial denitrification/anammox (SPDA) system was investigated in a moving bed biofilm reactor (MBBR) inoculated with partial denitrification (PD) and anaerobic ammonium oxidation (anammox) biofilms. The SPDA system was operated at 25 ± 1 °C over 260 days. The total nitrogen (TN) of the effluent was only 3.71 ± 0.92 mg·L-1 in the stable phase with a TN removal efficiency of 95.23%. The anammox process was the dominant nitrogen removal pathway with an average contribution of 74.31% to TN removal. The results of the in situ activity and key enzymatic activity revealed that the nitrate-reducing bacteria tended to immigrate to anammox biofilms. Correspondingly, the abundance of the genus Thauera, the second most dominant bacteria in anammox biofilms, quickly increased from 0.78 to 10.69% on day 50 and eventually to 16.45% on day 221 according to the Illumina MiSeq sequencing data. The microbial immigration might be caused by different extracellular polymeric substance (EPS)-mediated mechanisms in PD and anammox biofilms. For fast-growing denitrifiers, PD biofilms tend to increase the ability of mass transfer by excreting more polysaccharides to form loosely-bound EPS at the expense of the ability to harbor the nitrate-reducing bacteria. However, for the slow-growing anaerobic ammonium oxidizing bacteria (AnAOB), the anammox biofilms tend to increase the retention of AnAOB by excreting more proteins to form enhanced tightly-bound EPS at the expense of the mass transfer ability, thereby causing the detached nitrate-reducing bacteria to immigrate into anammox biofilms.
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Affiliation(s)
- Lifang Yu
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, 13#, Yanta Road, Xi'an 710055, China.
| | - Qiong Zhang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, 13#, Yanta Road, Xi'an 710055, China
| | - Ren Li
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, 13#, Yanta Road, Xi'an 710055, China
| | - Bingchuang Qiao
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, 13#, Yanta Road, Xi'an 710055, China
| | - Ze Wang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, 13#, Yanta Road, Xi'an 710055, China
| | - Lanxiang Zheng
- College of Ecology and Environment, Ningxia University, Yinchuan 750021, China; China Wine Industry Technology Institute, Yinchuan 750021, China
| | - Dangcong Peng
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, 13#, Yanta Road, Xi'an 710055, China
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BOU-SARKIS A, PAGLIACCIA B, RIC A, DERLON N, PAUL E, BESSIERE Y, GIRBAL-NEUHAUSER E. Effects of alkaline solvents and heating temperatures on the solubilization and degradation of gel-forming Extracellular Polymeric Substances extracted from aerobic granular sludge. Biochem Eng J 2022. [DOI: 10.1016/j.bej.2022.108500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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5
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Feng Q, Luo L, Chen X, Zhang K, Fang F, Xue Z, Li C, Cao J, Luo J. Facilitating biofilm formation of Pseudomonas aeruginosa via exogenous N-Acy-L-homoserine lactones stimulation: Regulation on the bacterial motility, adhesive ability and metabolic activity. BIORESOURCE TECHNOLOGY 2021; 341:125727. [PMID: 34411944 DOI: 10.1016/j.biortech.2021.125727] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 07/31/2021] [Accepted: 08/04/2021] [Indexed: 06/13/2023]
Abstract
The N-Acy-L-homoserine lactones (AHLs) mediated quorum sensing (QS) system exhibited important ecological significance in bacterial biofilm formation. However, the previous studies mainly focused on indigenous AHLs while the role of exogenous AHLs has remained unclear. This study evaluated the roles of exogenous AHLs on the biofilm formation of Pseudomonas aeruginosa. Both the C6-HSL and C8-HSL promoted the biofilm formation of P. aeruginosa with an enhancement of 2.47 and 1.88 times, respectively. Further analysis showed that exogenous AHLs contributed greatly to the adhesive ability instead of growth rate. Also, the bacterial motility and metabolic activities were significantly improved by AHLs. Moreover, the microbial functional genes (i.e. lasI, lasR, rhlI and rhlR) involved in regulating the biofilm formation were highly expressed in AHLs reactors. These findings expanded the knowledge of AHLs functions in mediating biofilm formation, and provided insightful guidance on the biofilm regulation in the wastewater treatment via biofilm technology.
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Affiliation(s)
- Qian Feng
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Laiwei Luo
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Xindi Chen
- Department of Hydraulic Engineering, Tsinghua University, Beijing 100091, China
| | - Kaijie Zhang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Fang Fang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Zhaoxia Xue
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Chao Li
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Jiashun Cao
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Jingyang Luo
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China.
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6
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Liou HC, Sabba F, Wang Z, Wells G, Balogun O. Layered viscoelastic properties of granular biofilms. WATER RESEARCH 2021; 202:117394. [PMID: 34256191 DOI: 10.1016/j.watres.2021.117394] [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: 03/12/2021] [Revised: 06/22/2021] [Accepted: 06/23/2021] [Indexed: 06/13/2023]
Abstract
Granular biofilms are dense spherical complex biological systems composed mainly of multi-microbial cells, water, and extracellular polymeric substances (EPS). They facilitate efficient purification and settling of activated sludge in wastewater treatment processes. The viscoelastic properties of these complex biofilm systems are important characteristics that control their growth and dictate how they respond to hydrodynamic forces and chemical stimuli. However, the viscoelastic properties of granular biofilms are poorly understood. In this paper, we study granular biofilms' viscoelastic properties using optical coherence elastography (OCE), a nondestructive method that integrates optical coherence tomography (OCT) with elastic wave propagation. While quantitative viscoelastic characterization of granular biofilms is challenging due to their heterogeneous properties, we show that elastic waves are suitable for this purpose. First, we employ guided elastic waves in a thin section of a granular biofilm to reveal a two-layered profile for the viscoelastic properties. Next, we utilize circumferential elastic waves that propagate near the surface of a non-sectioned spherical biofilm to quantify the layered system's viscoelastic properties. To the best of our knowledge, this work is the first quantitative study that characterizes the layered viscoelastic properties of granular biofilms. The measurement approach may provide a platform to study the interplay between the viscoelastic properties and other characteristics of granular biofilms such as the complex microbial system, morphology, and oxygen distribution.
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Affiliation(s)
- Hong-Cin Liou
- Mechanical Engineering Department, Northwestern University, Evanston, IL 60208, United States
| | - Fabrizio Sabba
- Civil and Environmental Engineering Department, Northwestern University, Evanston, IL 60208, United States
| | - Ziwei Wang
- Mechanical Engineering Department, Northwestern University, Evanston, IL 60208, United States
| | - George Wells
- Civil and Environmental Engineering Department, Northwestern University, Evanston, IL 60208, United States
| | - Oluwaseyi Balogun
- Mechanical Engineering Department, Northwestern University, Evanston, IL 60208, United States; Civil and Environmental Engineering Department, Northwestern University, Evanston, IL 60208, United States.
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7
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Chen GQ, Wu YH, Wang YH, Chen Z, Tong X, Bai Y, Luo LW, Xu C, Hu HY. Effects of microbial inactivation approaches on quantity and properties of extracellular polymeric substances in the process of wastewater treatment and reclamation: A review. JOURNAL OF HAZARDOUS MATERIALS 2021; 413:125283. [PMID: 33582467 DOI: 10.1016/j.jhazmat.2021.125283] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 01/25/2021] [Accepted: 01/29/2021] [Indexed: 06/12/2023]
Abstract
Microbial extracellular polymeric substances (EPS) have a profound role in various wastewater treatment and reclamation processes, in which a variety of technologies are used for disinfection and microbial growth inhibition. These treatment processes can induce significant changes in the quantity and properties of EPS, and altered EPS could further adversely affect the wastewater treatment and reclamation system, including membrane filtration, disinfection, and water distribution. To clarify the effects of microbial inactivation approaches on EPS, these effects were classified into four categories: (1) chemical reactions, (2) cell lysis, (3) changing EPS-producing metabolic processes, and (4) altering microbial community. Across these different effects, treatments with free chlorine, methylisothiazolone, TiO2, and UV irradiation typically enhance EPS production. Among the residual microorganisms in EPS matrices after various microbial inactivation treatments, one of the most prominent is Mycobacterium. With respect to EPS properties, proteins and humic acids in EPS are usually more susceptible to treatment processes than polysaccharides. The affected EPS properties include changes in molecular weight, hydrophobicity, and adhesion ability. All of these changes can undermine wastewater treatment and reclamation processes. Therefore, effects on EPS quantity and properties should be considered during the application of microbial inactivation and growth inhibition techniques.
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Affiliation(s)
- Gen-Qiang Chen
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing 100084, PR China; Beijing Laboratory for Environmental Frontier Technologies, Beijing 100084, PR China
| | - Yin-Hu Wu
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing 100084, PR China; Beijing Laboratory for Environmental Frontier Technologies, Beijing 100084, PR China.
| | - Yun-Hong Wang
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing 100084, PR China; Beijing Laboratory for Environmental Frontier Technologies, Beijing 100084, PR China
| | - Zhuo Chen
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing 100084, PR China; Beijing Laboratory for Environmental Frontier Technologies, Beijing 100084, PR China
| | - Xing Tong
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing 100084, PR China; Beijing Laboratory for Environmental Frontier Technologies, Beijing 100084, PR China
| | - Yuan Bai
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing 100084, PR China; Beijing Laboratory for Environmental Frontier Technologies, Beijing 100084, PR China
| | - Li-Wei Luo
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing 100084, PR China; Beijing Laboratory for Environmental Frontier Technologies, Beijing 100084, PR China
| | - Chuang Xu
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing 100084, PR China; Beijing Laboratory for Environmental Frontier Technologies, Beijing 100084, PR China
| | - Hong-Ying Hu
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment, Tsinghua University, Beijing 100084, PR China; Beijing Laboratory for Environmental Frontier Technologies, Beijing 100084, PR China; Shenzhen Environmental Science and New Energy Technology Engineering Laboratory, Tsinghua-Berkeley Shenzhen Institute, Shenzhen 518055, PR China
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8
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Ou Q, Xu Y, Li X, He Q, Liu C, Zhou X, Wu Z, Huang R, Song J, Huangfu X. Interactions between activated sludge extracellular polymeric substances and model carrier surfaces in WWTPs: A combination of QCM-D, AFM and XDLVO prediction. CHEMOSPHERE 2020; 253:126720. [PMID: 32464762 DOI: 10.1016/j.chemosphere.2020.126720] [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: 02/21/2020] [Revised: 03/23/2020] [Accepted: 04/04/2020] [Indexed: 06/11/2023]
Abstract
To understand the biofilm formation of biofilm-based processes in wastewater treatment plants (WWTPs), the interaction mechanisms between extracted extracellular polymeric substances (EPS) and three model carrier surfaces (i.e., negatively charged hydrophilic silica, positively charged hydrophilic alumina, and neutral charged hydrophobic polystyrene) were investigated employing a laboratory quartz crystal microbalance with dissipation monitoring equipment (QCM-D) and an atomic force microscope (AFM). The data suggested that surface charge and hydrophobicity of both EPS and carriers played significant roles in the interaction behaviors. Moreover, increases in ionic strength could lead to the increasing zeta potential and hydrophobicity of EPS. It is worth noting that long-range DLVO forces dominated the EPS deposition on carriers in lower ionic strength while short-range Lewis acid-base (AB) interaction controlled the adhesion behaviors in higher ionic strength. Besides, the presence of calcium ions contributed to the adhesion behaviors because of strong charge neutralization and hydrophobic effect. Bound EPS (BEPS) showed higher affinity to model carriers than dissolved EPS (DEPS), which conformed to XDLVO prediction rather than classical DLVO model. Overall, these results provide insights into the influence mechanisms of carrier characteristics, ionic strength, calcium ion and EPS components on the interaction between EPS and representative carriers, contributing to predict and regulate biofilm formation in biofilm-based processes.
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Affiliation(s)
- Qin Ou
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Faculty of Urban Construction and Environmental Engineering, Chongqing University, 400044, China
| | - Yanghui Xu
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Faculty of Urban Construction and Environmental Engineering, Chongqing University, 400044, China
| | - Xiaoling Li
- School of Civil Engineering, Key Laboratory of Water Supply & Sewage Engineering (Ministry of Housing and Urban-Rural Development), Chang'an University, Xi'an, 710054, PR China
| | - Qiang He
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Faculty of Urban Construction and Environmental Engineering, Chongqing University, 400044, China
| | - Caihong Liu
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Faculty of Urban Construction and Environmental Engineering, Chongqing University, 400044, China
| | - Xiaojun Zhou
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Faculty of Urban Construction and Environmental Engineering, Chongqing University, 400044, China
| | - Zhengsong Wu
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Faculty of Urban Construction and Environmental Engineering, Chongqing University, 400044, China
| | - Ruixing Huang
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Faculty of Urban Construction and Environmental Engineering, Chongqing University, 400044, China
| | - Jiahui Song
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Faculty of Urban Construction and Environmental Engineering, Chongqing University, 400044, China
| | - Xiaoliu Huangfu
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Faculty of Urban Construction and Environmental Engineering, Chongqing University, 400044, China.
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9
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Chen S, Dong B, Yang D, Li N, Dai X. Micron-sized silica particles in wastewater influenced the distribution of organic matters in sludge and their anaerobic degradation. JOURNAL OF HAZARDOUS MATERIALS 2020; 393:122340. [PMID: 32213426 DOI: 10.1016/j.jhazmat.2020.122340] [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: 10/10/2019] [Revised: 02/12/2020] [Accepted: 02/15/2020] [Indexed: 06/10/2023]
Abstract
The influence of micron-sized silica particles on the distribution of organic matters in sludge and anaerobic degradation of macromolecular organic components (MOCs) in sludge was investigated. With the addition of micron-sized particles in the influent (VS/TS decreased gradually from 90.46 ± 0.21 % to 33.36 ± 0.17 %), the protein degradation percentage was significantly promoted while the polysaccharides degradation percentage was largely inhibited, resulting in the total MOCs degradation and methane production increasing firstly (with the promotion extent within 10 %) and then declining slightly, with the peak value at VS/TS of 56.03 ± 0.21 %. The shifted degradation percentage of protein and polysaccharides were caused by the significant changed distribution of organic matters in sludge. With the addition of micron-sized silica particles, the MW of EPS and secondary structure of protein in EPS changed little, which brought about little influence. While, the promoted extracellular protein content (so that the total protein content) and declined extracellular carbohydrates content (so that the total polysaccharides content), were found to be strongly correlated to the enhanced protein degradation and inhibited polysaccharides degradation. The results suggested that large amounts of grit in sludge might not be the main reason for lower degradability of sewage sludge in China.
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Affiliation(s)
- Sisi Chen
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China
| | - Bin Dong
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China.
| | - Dianhai Yang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China.
| | - Ning Li
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China
| | - Xiaohu Dai
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China
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10
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Farhat NM, Javier L, Van Loosdrecht MCM, Kruithof JC, Vrouwenvelder JS. Role of feed water biodegradable substrate concentration on biofouling: Biofilm characteristics, membrane performance and cleanability. WATER RESEARCH 2019; 150:1-11. [PMID: 30508707 DOI: 10.1016/j.watres.2018.11.054] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Revised: 10/25/2018] [Accepted: 11/19/2018] [Indexed: 06/09/2023]
Abstract
Biofouling severely impacts operational performance of membrane systems increasing the cost of water production. Understanding the effect of critical parameters of feed water such as biodegradable substrate concentration on the developed biofilm characteristics enables development of more effective biofouling control strategies. In this study, the effect of substrate concentration on the biofilm characteristics was examined using membrane fouling simulators (MFSs). A feed channel pressure drop (PD) increase of 200 mbar was used as a benchmark to study the developed biofilm. The amount and characteristics of the formed biofilm were analysed in relation to membrane performance indicators: feed channel pressure drop and permeate flux. The effect of the characteristics of the biofilm developed at three substrate concentrations on the removal efficiency of the different biofilms was evaluated applying acid/base cleaning. Results showed that a higher feed water substrate concentration caused a higher biomass amount, a faster PD increase, but a lower permeate flux decline. The permeate flux decline was affected by the spatial location and the physical characteristics of the biofilm rather than the total amount of biofilm. The slower growing biofilm developed at the lowest substrate concentration was harder to remove by NaOH/HCl cleanings than the biofilm developed at the higher substrate concentrations. Effective biofilm removal is essential to prevent a fast biofilm regrowth after cleaning. While substrate limitation is a generally accepted biofouling control strategy delaying biofouling, development of advanced cleaning methods to remove biofilms formed under substrate limited conditions is of paramount importance.
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Affiliation(s)
- N M Farhat
- King Abdullah University of Science and Technology (KAUST), Water Desalination and Reuse Center (WDRC), Division of Biological and Environmental Science and Engineering (BESE), Thuwal, 23955-6900, Saudi Arabia.
| | - L Javier
- King Abdullah University of Science and Technology (KAUST), Water Desalination and Reuse Center (WDRC), Division of Biological and Environmental Science and Engineering (BESE), Thuwal, 23955-6900, Saudi Arabia
| | - M C M Van Loosdrecht
- Delft University of Technology, Faculty of Applied Sciences, Department of Biotechnology, Van der Maasweg 9, 2629, HZ, Delft, the Netherlands
| | - J C Kruithof
- Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911, MA, Leeuwarden, the Netherlands
| | - J S Vrouwenvelder
- King Abdullah University of Science and Technology (KAUST), Water Desalination and Reuse Center (WDRC), Division of Biological and Environmental Science and Engineering (BESE), Thuwal, 23955-6900, Saudi Arabia; Delft University of Technology, Faculty of Applied Sciences, Department of Biotechnology, Van der Maasweg 9, 2629, HZ, Delft, the Netherlands
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Nandu TG, Subramenium GA, Shiburaj S, Viszwapriya D, Iyer PM, Balamurugan K, Rameshkumar KB, Karutha Pandian S. Fukugiside, a biflavonoid from Garcinia travancorica inhibits biofilm formation of Streptococcus pyogenes and its associated virulence factors. J Med Microbiol 2018; 67:1391-1401. [PMID: 30052177 DOI: 10.1099/jmm.0.000799] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
PURPOSE Streptococcus pyogenes, a notorious human pathogen thatis responsible for various invasive and non-invasive diseases, possesses multiple virulence armaments, including biofilm formation. The current study demonstrates the anti-biofilm and anti-virulence potential of fukugiside, a biflavonoid isolated from Garciniatravancorica, against S. pyogenes. METHODOLOGY The anti-biofilm activity of fukugiside was assessed and established using microdilution and microscopic analysis. Biochemical assays were performed to assess the effects of fukugiside on important virulence factors, which were further validated using quantitative real-time PCR and in vivo analysis in Caenorhabditis elegans. RESULTS Fukugiside exhibited concentration-dependent biofilm inhibition (79 to 96 %) against multiple M serotypes of S. pyogenes (M1, M56, M65, M74, M100 and st38) with a minimum biofilm inhibitory concentration of 80 µg ml-1. Electron microscopy and biochemical assay revealed a significant reduction in extracellular polymeric substance production. The results for the microbial adhesion to hydrocarbon assay, extracellular protease quantification and differential regulation of the dltA, speB, srv and ropB genes suggested that fukugiside probably inhibits biofilm formation by lowering cell surface hydrophobicity and destabilizing the biofilm matrix. The enhanced susceptibility to phagocytosis evidenced in the blood survival assay goes in unison with the downregulation of mga. The downregulation of important virulence factor-encoding genes such as hasA, slo and col370 suggested impaired virulence. In vivo analysis in C. elegans evinced the non-toxic nature of fukugiside and its anti-virulence potential against S. pyogenes. CONCLUSION Fukugiside exhibits potent anti-biofilm and anti-virulence activity against different M serotypes of S. pyogenes. It is also non-toxic, which augurs well for its clinical application.
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Affiliation(s)
- Thrithamarassery Gangadharan Nandu
- 1Division of Microbiology, Jawaharlal Nehru Tropical Botanic Garden and Research Institute, Palode, Thiruvananthapuram-695562, Kerala, India
| | | | - Sugathan Shiburaj
- 1Division of Microbiology, Jawaharlal Nehru Tropical Botanic Garden and Research Institute, Palode, Thiruvananthapuram-695562, Kerala, India
| | - Dharmaprakash Viszwapriya
- 2Department of Biotechnology, Alagappa University, Science Campus, Karaikudi 630 004, Tamil Nadu, India
| | - Prasanth Mani Iyer
- 2Department of Biotechnology, Alagappa University, Science Campus, Karaikudi 630 004, Tamil Nadu, India
| | - Krishnaswamy Balamurugan
- 2Department of Biotechnology, Alagappa University, Science Campus, Karaikudi 630 004, Tamil Nadu, India
| | - Koranappallil Bahuleyan Rameshkumar
- 3Division of Phytochemistry and Phytopharmacology, Jawaharlal Nehru Tropical Botanic Garden and Research Institute, Palode, Thiruvananthapuram-695562, Kerala, India
| | - Shunmugiah Karutha Pandian
- 2Department of Biotechnology, Alagappa University, Science Campus, Karaikudi 630 004, Tamil Nadu, India
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Characterization and Production of Extracellular Polysaccharides (EPS) by Bacillus Pseudomycoides U10. ENVIRONMENTS 2018. [DOI: 10.3390/environments5060063] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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13
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Cao F, Bourven I, Lens PNL, van Hullebusch ED, Pechaud Y, Guibaud G. Hydrophobic features of EPS extracted from anaerobic granular sludge: an investigation based on DAX-8 resin fractionation and size exclusion chromatography. Appl Microbiol Biotechnol 2016; 101:3427-3438. [PMID: 28012045 DOI: 10.1007/s00253-016-8053-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 11/14/2016] [Accepted: 12/05/2016] [Indexed: 12/23/2022]
Abstract
The hydrophobic fractionation of extracellular polymeric substances (EPS) extracted from anaerobic granular sludge was performed on the DAX-8 resin (two elution pH conditions, i.e., pH 2 and pH 5 were tested). The impact of seven different EPS extraction methods on EPS hydrophobicity features was assessed. The results showed that the extraction methods and bulk solution pH influenced dramatically the biochemical composition of the EPS, and in turn, the hydrophobicity determined. Besides, EPS extracting reagents i.e., formaldehyde, ethanol, sodium dodecyl sulfate (SDS), and Tween 20 not only introduced extra carbon content in the total organic carbon (TOC) measurement but also interacted with the DAX-8 resin. By comparing the apparent molecular weight (aMW) distribution of untreated and pH-adjusted EPS samples, more complete EPS aMW information was preserved at pH 5. Thus, elution at pH 5 was preferred in this study for the qualitative analysis of EPS hydrophobic features. The hydrophobic fraction of EPS retained by the resin at pH 5 was ascribed to a wide aMW range, ranging from >440 to 0.3 kDa. Within this range, EPS molecules ranging from 175 to 31 kDa were mostly retained by the DAX-8 resin, which indicates that these EPS molecules are highly hydrophobic.
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Affiliation(s)
- Feishu Cao
- Laboratoire Géomatériaux et Environnement (EA 4508), Université Paris-Est, UPEM, 77454, Marne-la-Vallée, France.,Groupement de Recherche Eau Sol Environnement (EA 4330), Faculté des Sciences et Techniques, Université de Limoges, 123 Avenue A. Thomas, 87060, Limoges Cedex, France.,UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX, Delft, The Netherlands
| | - Isabelle Bourven
- Groupement de Recherche Eau Sol Environnement (EA 4330), Faculté des Sciences et Techniques, Université de Limoges, 123 Avenue A. Thomas, 87060, Limoges Cedex, France
| | - Piet N L Lens
- UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX, Delft, The Netherlands
| | - Eric D van Hullebusch
- Laboratoire Géomatériaux et Environnement (EA 4508), Université Paris-Est, UPEM, 77454, Marne-la-Vallée, France.,UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX, Delft, The Netherlands
| | - Yoan Pechaud
- Laboratoire Géomatériaux et Environnement (EA 4508), Université Paris-Est, UPEM, 77454, Marne-la-Vallée, France
| | - Gilles Guibaud
- Groupement de Recherche Eau Sol Environnement (EA 4330), Faculté des Sciences et Techniques, Université de Limoges, 123 Avenue A. Thomas, 87060, Limoges Cedex, France.
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Viszwapriya D, Prithika U, Deebika S, Balamurugan K, Pandian SK. In vitro and in vivo antibiofilm potential of 2,4-Di- tert -butylphenol from seaweed surface associated bacterium Bacillus subtilis against group A streptococcus. Microbiol Res 2016; 191:19-31. [DOI: 10.1016/j.micres.2016.05.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 04/11/2016] [Accepted: 05/20/2016] [Indexed: 02/08/2023]
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15
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Saur T, Escudié R, Santa-Catalina G, Bernet N, Milferstedt K. Conservation of acquired morphology and community structure in aged biofilms after facing environmental stress. WATER RESEARCH 2016; 88:164-172. [PMID: 26492343 DOI: 10.1016/j.watres.2015.10.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 09/28/2015] [Accepted: 10/08/2015] [Indexed: 06/05/2023]
Abstract
The influence of growth history on biofilm morphology and microbial community structure is poorly studied despite its important role for biofilm development. Here, biofilms were exposed to a change in hydrodynamic conditions at different growth stages and we observed how biofilm age affected the change in morphology and bacterial community structure. Biofilms were developed in two bubble column reactors, one operated under constant shear stress and one under variable shear stress. Biofilms were transferred from one reactor to the other at different stages in their development by withdrawing and inserting the support medium from one reactor to the other. The developments of morphology and microbial community structure were followed by image analysis and molecular tools. When transferred early in biofilm development, biofilms adapted to the new hydrodynamic conditions and adopted features of the biofilm already developed in the receiving reactor. Biofilms transferred at a late state of biofilm development continued their initial trajectories of morphology and community development even in a new environment. These biofilms did not immediately adapt to their new environment and kept features acquired during their early growth phase, a property we called memory effect.
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Affiliation(s)
- T Saur
- INRA, UR0050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, F-11100 Narbonne, France
| | - R Escudié
- INRA, UR0050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, F-11100 Narbonne, France
| | - G Santa-Catalina
- INRA, UR0050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, F-11100 Narbonne, France
| | - N Bernet
- INRA, UR0050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, F-11100 Narbonne, France
| | - K Milferstedt
- INRA, UR0050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, F-11100 Narbonne, France.
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Mercier A, Bertaux J, Lesobre J, Gravouil K, Verdon J, Imbert C, Valette E, Héchard Y. Characterization of biofilm formation in natural water subjected to low-frequency electromagnetic fields. BIOFOULING 2016; 32:287-299. [PMID: 26905178 DOI: 10.1080/08927014.2015.1137896] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Electromagnetic field (EMF) treatment has proven to be effective against mineral scaling in water systems. Therefore, it should be assessed for the treatment of other deposits such as biofilms. In this study, a commercial device producing low-frequency EMF (1-10 kHz) was applied to a reactor fed with natural water for 45 days. The treatment promoted the concentration of microorganisms in suspension and limited the amount of sessile microorganisms in the biofilm, as determined by the measurement of total DNA, qPCR and microscopy. The structure of the bacterial community was assessed by t-RFLP and pyrosequencing analysis. The results showed that EMF treatment affected both planktonic and sessile community composition. EMFs were responsible for a shift in classes of Proteobacteria during development of the biofilm. It may be speculated that the EMF treatment affected particle solubility and/or microorganism hydration. This study indicated that EMFs modulated biofilm formation in natural water.
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Affiliation(s)
- Anne Mercier
- a Equipe Microbiologie de l'Eau, Ecologie et Biologie des Interactions, Centre National de la Recherche Scientifique UMR 7267 , Université de Poitiers , Poitiers , France
| | - Joanne Bertaux
- b Equipe Ecologie Evolution Symbiose, Ecologie et Biologie des Interactions, Centre National de la Recherche Scientifique UMR 7267 , Université de Poitiers , Poitiers , France
| | - Jérôme Lesobre
- a Equipe Microbiologie de l'Eau, Ecologie et Biologie des Interactions, Centre National de la Recherche Scientifique UMR 7267 , Université de Poitiers , Poitiers , France
- b Equipe Ecologie Evolution Symbiose, Ecologie et Biologie des Interactions, Centre National de la Recherche Scientifique UMR 7267 , Université de Poitiers , Poitiers , France
| | - Kevin Gravouil
- c Laboratoire coopératif ThanaplastSP-EBI-Carbios Bioplastics, Ecologie et Biologie des Interactions, Centre National de la Recherche Scientifique UMR 7267 , Université de Poitiers , Poitiers , France
| | - Julien Verdon
- a Equipe Microbiologie de l'Eau, Ecologie et Biologie des Interactions, Centre National de la Recherche Scientifique UMR 7267 , Université de Poitiers , Poitiers , France
| | - Christine Imbert
- a Equipe Microbiologie de l'Eau, Ecologie et Biologie des Interactions, Centre National de la Recherche Scientifique UMR 7267 , Université de Poitiers , Poitiers , France
| | - Eric Valette
- d Planet Horizons Technologies , Technopole 5, Sierre , Switzerland
| | - Yann Héchard
- a Equipe Microbiologie de l'Eau, Ecologie et Biologie des Interactions, Centre National de la Recherche Scientifique UMR 7267 , Université de Poitiers , Poitiers , France
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Bourven I, Bachellerie G, Costa G, Guibaud G. Evidence of glycoproteins and sulphated proteoglycan-like presence in extracellular polymeric substance from anaerobic granular sludge. ENVIRONMENTAL TECHNOLOGY 2015; 36:2428-2435. [PMID: 25812669 DOI: 10.1080/09593330.2015.1034186] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The protein fraction of extracellular polymeric substance (EPS) from two anaerobic granular sludge samples was characterized with sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and a far western blotting method. SDS-PAGE was used with various staining applications to obtain a protein (silver), glycoprotein [periodic acid-Shiff's (PAS)] or proteoglycan-like (Alcian blue at pH 2.5 (carboxylic group) or 1 (sulphated group)) fingerprint. The fingerprints of the EPS denatured protein from the two sludge samples differed. Some proteins are specific to Soluble (S) or Bound (B)-EPS (20-100 kDa). Denatured proteins with a polysaccharide moieties characterization are more present in B-EPS. Glycoproteins with α-d-mannosyl and/or α-d-glucosyl (90, 50, 40 kDa) were detected. Proteoglycan-like and sulphated proteoglycan-like substances are also detected, mainly in B-EPS. A 68 kDa sulphated proteoglycan-like substance contains two glucidic residue types: α-d-mannosyl and/or α-d-glucosyl and N-acetyl-β-d-glucosamine. Such heteroproteins are present around the membrane as well as the surface-layer from Archaea and from some bacteria. The glycoprotein and sulphated proteoglycan-like substance are assumed to contribute to anaerobic granule strength, thanks to their ability to perform interactions of various nature (ionic, hydrophobic, Ca(2+) as divalent cation bridging, etc.).
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Affiliation(s)
- Isabelle Bourven
- a Faculté des Sciences et Techniques , Université de Limoges, Groupement de Recherche Eau Sol Environnement (EA 4330) , 123 Av. Albert Thomas, 87060 Limoges , France
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Zhu Y, Zhang Y, Ren HQ, Geng JJ, Xu K, Huang H, Ding LL. Physicochemical characteristics and microbial community evolution of biofilms during the start-up period in a moving bed biofilm reactor. BIORESOURCE TECHNOLOGY 2015; 180:345-51. [PMID: 25636169 DOI: 10.1016/j.biortech.2015.01.006] [Citation(s) in RCA: 120] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 01/01/2015] [Accepted: 01/03/2015] [Indexed: 05/06/2023]
Abstract
This study aimed to investigate biofilm properties evolution coupled with different ages during the start-up period in a moving bed biofilm reactor system. Physicochemical characteristics including adhesion force, extracellular polymeric substances (EPS), morphology as well as volatile solid and microbial community were studied. Results showed that the formation and development of biofilms exhibited four stages, including (I) initial attachment and young biofilm formation, (II) biofilms accumulation, (III) biofilm sloughing and updating, and (IV) biofilm maturation. During the whole start-up period, adhesion force was positively and significantly correlated with the contents of EPS, especially the content of polysaccharide. In addition, increased adhesion force and EPS were beneficial for biofilm retention. Gram-negative bacteria mainly including Sphaerotilus, Zoogloea and Haliscomenobacter were predominant in the initial stage. Actinobacteria was beneficial to resist sloughing. Furthermore, filamentous bacteria were dominant in maturation biofilm.
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Affiliation(s)
- Yan Zhu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Yan Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Hong-Qiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China.
| | - Jin-Ju Geng
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Ke Xu
- 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
| | - Li-Li Ding
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China.
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Haq IU, Zhang M, Yang P, van Elsas JD. The interactions of bacteria with fungi in soil: emerging concepts. ADVANCES IN APPLIED MICROBIOLOGY 2014; 89:185-215. [PMID: 25131403 DOI: 10.1016/b978-0-12-800259-9.00005-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In this chapter, we review the existing literature on bacterial-fungal interactions in soil, exploring the role fungi may play for soil bacteria as providers of hospitable niches. A focus is placed on the mycosphere, i.e., the narrow zone of influence of fungal hyphae on the external soil milieu, in which hypha-associated bacterial cells dwell. Evidence is brought forward for the contention that the hyphae of both mycorrhizal and saprotrophic fungi serve as providers of ecological opportunities in a grossly carbon-limited soil, as a result of their release of carbonaceous compounds next to the provision of a colonizable surface. Soil bacteria of particular nature are postulated to have adapted to such selection pressures, evolving to the extent that they acquired capabilities that allow them to thrive in the novel habitat created by the emerging fungal hyphae. The mechanisms involved in the interactions and the modes of genetic adaptation of the mycosphere dwellers are discussed, with an emphasis on one key mycosphere-adapted bacterium, Burkholderia terrae BS001. In this discussion, we interrogate the positive interactions between soil fungi and bacteria, and refrain from considering negative interactions.
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Affiliation(s)
- Irshad Ul Haq
- Department of Microbial Ecology, Center for Ecological and Evolutionary Studies (CEES), University of Groningen, Groningen, The Netherlands
| | - Miaozhi Zhang
- Department of Microbial Ecology, Center for Ecological and Evolutionary Studies (CEES), University of Groningen, Groningen, The Netherlands
| | - Pu Yang
- Department of Microbial Ecology, Center for Ecological and Evolutionary Studies (CEES), University of Groningen, Groningen, The Netherlands
| | - Jan Dirk van Elsas
- Department of Microbial Ecology, Center for Ecological and Evolutionary Studies (CEES), University of Groningen, Groningen, The Netherlands.
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Abstract
We present a model of biofilm growth in a long channel where the biomass is assumed to have the rheology of a viscous polymer solution. We examine the competition between growth and erosion-like surface detachment due to the flow. A particular focus of our investigation is the effect of the biofilm growth on the fluid flow in the pores, and the issue of whether biomass can grow sufficiently to shut off fluid flow through the pores, thus clogging the pore space. Net biofilm growth is coupled along the pore length via flow rate and nutrient transport in the pore flow. Our 2D model extends existing results on stability of 1D steady state biofilm thicknesses to show that, in the case of flows driven by a fixed pressure drop, full clogging of the pore can indeed happen in certain cases dependent on the functional form of the detachment term.
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