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Wu F, Yuan C, Ruan C, Zheng M, Liu L, Wang G, Chen G. Coagulation promotes the spread of antibiotic resistance genes in secondary effluents. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 355:124245. [PMID: 38810683 DOI: 10.1016/j.envpol.2024.124245] [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: 09/05/2023] [Revised: 05/04/2024] [Accepted: 05/26/2024] [Indexed: 05/31/2024]
Abstract
Wastewater treatment plants (WWTPs) are biological hotspots receiving the residual antibiotics and antibiotic resistant bacteria/genes (ARB/ARGs) that greatly influence the spread of antibiotic resistance in the environment. A common method used in WWTPs for the purification of secondary effluent is coagulation. Notwithstanding the increasing health concern of antibiotic resistance in WWTPs, the impact of coagulation on the emergence and spread of antibiotic resistance remains unclear. To shed light on this, our study investigated the behavior of four representative ARB types (tetracycline, sulfamethoxazole, clindamycin, and ciprofloxacin resistance) during the coagulation process in a model wastewater treatment plant. Our search showed a significant reduction in the presence of ARBs after either PAC or FeCl3 coagulation, with removal efficiencies of 95% and 90%, respectively. However, after 4 days of storage, ARB levels in the coagulated effluent increased by 6-138 times higher than the original secondary effluent. It suggests a potential resurgence and spread of antibiotic resistance after coagulation. Detailed studies suggest that coagulants, particularly PAC, may facilitate the transfer of ARGs among different bacterial species by the enhanced cell-cell contact during coagulation-induced bacterial aggregation. This transfer is further enhanced by the factors such as auxiliary mixing, longer incubation time and ideal operating temperatures. In addition, both PAC and FeCl3 affected gene expression associated with bacterial conjugation, leading to an increase in conjugation efficiency. In conclusion, while coagulation serves as a purification method, it might inadvertently boost the spread of ARGs during tertiary wastewater treatment. This underscores the importance of implementing subsequent measures to mitigate this effect. Our findings provide a deeper understanding of the challenges posed by bacterial antibiotic resistance in wastewater and pave the way for devising more effective ARB and ARG management strategies.
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Affiliation(s)
- Fazhu Wu
- Department of Civil Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Chao Yuan
- Department of Civil Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Chujin Ruan
- Department of Soil and Water Sciences, China Agricultural University, Beijing, 100193, China; Department of Environmental Microbiology, Swiss Federal Institute of Aquatic Science and Technology (Eawag), Dübendorf, 8600, Switzerland
| | - Mengqi Zheng
- Department of Civil Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Li Liu
- Department of Civil Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Gang Wang
- Department of Soil and Water Sciences, China Agricultural University, Beijing, 100193, China
| | - Guowei Chen
- Department of Civil Engineering, Hefei University of Technology, Hefei, 230009, China.
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2
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Zhang JT, Wang JX, Liu Y, Zhang Y, Wang JH, Chi ZY, Kong FT. Microalgal-bacterial biofilms for wastewater treatment: Operations, performances, mechanisms, and uncertainties. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 907:167974. [PMID: 37884155 DOI: 10.1016/j.scitotenv.2023.167974] [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: 07/18/2023] [Revised: 09/28/2023] [Accepted: 10/18/2023] [Indexed: 10/28/2023]
Abstract
Microalgal-bacterial biofilms have been increasingly considered of great potential in wastewater treatment due to the advantages of microalgal-bacterial synergistic pollutants removal/recovery, CO2 sequestration, and cost-effective biomass-water separation. However, such advantages may vary widely among different types of microalgal-bacterial biofilms, as the biofilms could be formed on different shapes and structures of attachment substratum, generating "false hope" for certain systems in large-scale wastewater treatment if the operating conditions and pollutants removal properties are evaluated based on the general term "microalgal-bacterial biofilm". This study, therefore, classified microalgal-bacterial biofilms into biofilms formed on 2D substratum, biofilms formed on 3D substratum, and biofilms formed without substratum (i.e. microalgal-bacterial granular sludge, MBGS). Biofilms formed on 2D substratum display higher microalgae fractions and nutrients removal efficiencies, while the adopted long hydraulic retention times were unacceptable for large-scale wastewater treatment. MBGS are featured with much lower microalgae fractions, most efficient pollutants removal, and acceptable retention times for realistic application, yet the feasibility of using natural sunlight should be further explored. 3D substratum systems display wide variations in operating conditions and pollutants removal properties because of diversified substratum shapes and structures. 2D and 3D substratum biofilms share more common in eukaryotic and prokaryotic microbial community structures, while MGBS biofilms are more enriched with microorganisms favoring EPS production, biofilm formation, and denitrification. The specific roles of stratified extracellular polymeric substances (EPS) in nutrients adsorption and condensation still require in-depth exploration. Nutrients removal uncertainties caused by microalgal-bacterial synergy decoupling under insufficient illumination, limited microbial community control, and possible greenhouse gas emission exacerbation arising from microalgal N2O generation were also indicated. This review is helpful for revealing the true potential of applying various microalgal-bacterial biofilms in large-scale wastewater treatment, and will provoke some insights on the challenges to the ideal state of synergistic pollutants reclamation and carbon neutrality via microalgal-bacterial interactions.
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Affiliation(s)
- Jing-Tian Zhang
- School of Bioengineering, Dalian University of Technology, Dalian 116024, PR China
| | - Jian-Xia Wang
- School of Bioengineering, Dalian University of Technology, Dalian 116024, PR China
| | - Yang Liu
- School of Bioengineering, Dalian University of Technology, Dalian 116024, PR China
| | - Ying Zhang
- School of Bioengineering, Dalian University of Technology, Dalian 116024, PR China
| | - Jing-Han Wang
- School of Bioengineering, Dalian University of Technology, Dalian 116024, PR China; Key Laboratory of Environment Controlled Aquaculture, Dalian Ocean University, Dalian 116023, PR China.
| | - Zhan-You Chi
- School of Bioengineering, Dalian University of Technology, Dalian 116024, PR China
| | - Fan-Tao Kong
- School of Bioengineering, Dalian University of Technology, Dalian 116024, PR China
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3
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Li X, Chen G, Liu L, Wang G. Anaerobic sludge digestion elevates dissemination risks of bacterial antibiotic resistance in effluent supernatant. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 338:117854. [PMID: 37023605 DOI: 10.1016/j.jenvman.2023.117854] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 03/20/2023] [Accepted: 03/30/2023] [Indexed: 06/19/2023]
Abstract
Anaerobic digestion following a variety of pretreatments is a promising technique for the reduction of excess sludge in municipal wastewater treatment plants (MWWTPs), and eliminations of possible pathogens, viruses, protozoa, and other disease-causing organisms. Notwithstanding a rapidly increasing health concern of antibiotic resistant bacteria (ARB) in MWWTPs, dissemination risks of ARB in anaerobic digestion processes are still poorly understood, especially in the digested supernatant. Taking the representative ARB with respect to the common tetracycline-, sulfamethoxazole-, clindamycin- and ciprofloxacin resistance, we investigated the compositions of ARB in the sludge and supernatant, and quantified their variations along the entire anaerobic sludge digestion process following ultrasonication-, alkali-hydrolysis- and alkali-ultrasonication pretreatments, respectively. Results showed that the abundance of ARB was diminished by up to 90% from the sludge along anaerobic digestion coupling with the pretreatments. Surprisingly, pretreatments clearly boosted the abundance of specific ARB (e.g., 2.3 × 102 CFU/mL of tetracycline-resistant bacteria) in the supernatant that otherwise remained relatively low value of 0.6 × 102 CFU/mL from the direct digestion. Measurements of the soluble-, loosely-bound- and tightly-bound extracellular polymeric substances components revealed a gradually intensified destruction of the sludge aggregates along the entire anaerobic digestion processes, which could be likely responsible to the increase of the ARB abundance in the supernatant. Furthermore, analysis of the bacterial community components showed that the ARB populations were strongly correlated with the occurrence of Bacteroidetes, Patescibacteria, and Tenericutes. Interestingly, intensified conjugal transfer (0.015) of antibiotic resistance genes (ARGs) was observed upon returning of the digested supernatant to the biological treatment system. It implies the likelihood of ARGs spreading and subsequent ecological risks upon anaerobic digestion towards reducing excess sludge, and therefore requires further attentions for the excess sludge treatments especially of supernatant.
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Affiliation(s)
- Xia Li
- Department of Municipal Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Guowei Chen
- Department of Municipal Engineering, Hefei University of Technology, Hefei, 230009, China.
| | - Li Liu
- Department of Municipal Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Gang Wang
- Department of Soil and Water Sciences, China Agricultural University, Beijing, 100193, China
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4
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Chen G, Hu Z, Ebrahimi A, Johnson DR, Wu F, Sun Y, Shen R, Liu L, Wang G. Chemotactic movement and zeta potential dominate Chlamydomonas microsphaera attachment and biocathode development. ENVIRONMENTAL TECHNOLOGY 2023; 44:1838-1849. [PMID: 34859742 DOI: 10.1080/09593330.2021.2014575] [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: 07/28/2021] [Accepted: 11/29/2021] [Indexed: 06/13/2023]
Abstract
Microalgal cell attaching and biofilm formation are critical in the application of microalgal biocathode, which severs as one of the hopeful candidates to an original cathode in bioelectrochemical systems. Many efforts have been put in biofilm formation and bioelectrochemical systems for years, but the predominant factors shaping microalgal biocathode formation are sketchy. We launched a pair of researches to investigate microalgal attachment and biofilm formation in the presence/absence of applied voltages using Chlamydomonas microsphaera as a model unicellular motile microalga. In this study, we presented how microalga attached and biofilm formed on a carbon felt surface without applied voltages and try to manifest the most important aspects in this process. Results showed that while nutrient sources did not directly regulate cell attachment onto the carbon felt, limited initial nutrient concentration nevertheless promoted cell attachment. Specifically, nutrient availability did not influence the early stage (20-60 min) of microalgal cell attachment but did significantly impact cell attachment during later stages (240-720 min). Further analysis revealed that nutrient availability-mediated chemotactic movements and zeta potential are crucial to facilitate the initial attachment and subsequent biofilm formation of C. microsphaera onto the surfaces, serving as an important factor controlling microalgal surface attachment. Our results demonstrate that nutrient availability is a dominant factor controlling microalgal surface attachment and subsequent biofilm formation processes. This study provides a mechanistic understanding of microalgal surface attachment and biofilm formation processes on carbon felts surfaces in the absence of applied voltages.
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Affiliation(s)
- Guowei Chen
- Department of Civil Engineering, Hefei University of Technology, Hefei, People's Republic of China
| | - Zhen Hu
- Department of Civil Engineering, Hefei University of Technology, Hefei, People's Republic of China
| | - Ali Ebrahimi
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - David R Johnson
- Department of Environmental Microbiology, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
| | - Fazhu Wu
- Department of Civil Engineering, Hefei University of Technology, Hefei, People's Republic of China
| | - Yifei Sun
- Department of Soil and Water Sciences, China Agricultural University, Beijing, People's Republic of China
| | - Renhao Shen
- Department of Civil Engineering, Hefei University of Technology, Hefei, People's Republic of China
| | - Li Liu
- Department of Civil Engineering, Hefei University of Technology, Hefei, People's Republic of China
| | - Gang Wang
- Department of Soil and Water Sciences, China Agricultural University, Beijing, People's Republic of China
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5
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Lee SA, Kim M, Esterhuizen M, Le VV, Kang M, Ko SR, Oh HM, Kim YJ, Ahn CY. An acceleration of carotenoid production and growth of Haematococcus lacustris induced by host-microbiota network interaction. Microbiol Res 2022; 262:127097. [PMID: 35751943 DOI: 10.1016/j.micres.2022.127097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 06/13/2022] [Accepted: 06/15/2022] [Indexed: 02/07/2023]
Abstract
Haematococcus lacustris is a chlamydomonadalean with high biotechnological interest owing to its capacity to produce astaxanthin, a valuable secondary carotenoid with extraordinary antioxidation properties. However, its prolonged growth has limited its utility commercially. Thus, rapid growth to attain high densities of H. lacustris cells optimally producing astaxanthin is an essential biotechnological target to facilitate profitable commercialisation. Our study focused on characterising the bacterial communities associated with the alga's phycosphere by metagenomics. Subsequently, we altered the bacterial consortia in combined co-culture with key beneficial bacteria to optimise the growth of H. lacustris. The algal biomass increased by up to 2.1-fold in co-cultures, leading to a 1.6-fold increase in the astaxanthin yield. This study attempted to significantly improve the H. lacustris growth rate and biomass yield via Next-Generation Sequencing analysis and phycosphere bacterial augmentation, highlighting the possibility to overcome the hurdles associated with astaxanthin production by H. lacustris at a commercial scale.
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Affiliation(s)
- Sang-Ah Lee
- Environmental Safety Group, Korea Institute of Science and Technology (KIST) Europe, Saarbrücken 66123, Germany; Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea; Department of Environmental Biotechnology, KRIBB School of Biotechnology, University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of Korea
| | - Minsik Kim
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea
| | - Maranda Esterhuizen
- Environmental Safety Group, Korea Institute of Science and Technology (KIST) Europe, Saarbrücken 66123, Germany; Helsinki Institute of Sustainability Science (HELSUS), Fabianinkatu 33, 00014 Helsinki, Finland; University of Helsinki, Ecosystems and Environment Research Programme, Faculty of Biological and Environmental Sciences, Niemenkatu 73, 15140 Lahti, Finland; University of Manitoba, Clayton H. Riddell Faculty of Environment, Earth, and Resources, Wallace Building, 125 Dysart Road, Winnipeg MB R3T 2N2, Canada
| | - Ve Van Le
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea; Department of Environmental Biotechnology, KRIBB School of Biotechnology, University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of Korea
| | - Mingyeong Kang
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea; Department of Environmental Biotechnology, KRIBB School of Biotechnology, University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of Korea
| | - So-Ra Ko
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea
| | - Hee-Mock Oh
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea; Department of Environmental Biotechnology, KRIBB School of Biotechnology, University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of Korea
| | - Young Jun Kim
- Environmental Safety Group, Korea Institute of Science and Technology (KIST) Europe, Saarbrücken 66123, Germany.
| | - Chi-Yong Ahn
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea; Department of Environmental Biotechnology, KRIBB School of Biotechnology, University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of Korea.
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6
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Wang Y, Li J, Lei Y, Li X, Nagarajan D, Lee DJ, Chang JS. Bioremediation of sulfonamides by a microalgae-bacteria consortium - Analysis of pollutants removal efficiency, cellular composition, and bacterial community. BIORESOURCE TECHNOLOGY 2022; 351:126964. [PMID: 35272036 DOI: 10.1016/j.biortech.2022.126964] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 03/02/2022] [Accepted: 03/03/2022] [Indexed: 06/14/2023]
Abstract
Antibiotics in wastewaters (e.g., sulfonamides (SAs)) are not effectively removed by the conventional bacterial processes. In this study, a microalgae (Scenedesmus obliquus)-based process was evaluated for the removal of SAs. The maximum removal efficiency of sulfadiazine (SDZ) and sulfamethoxazole (SMX) by the consortium was 5.85% and 40.84%, respectively. The lower SDZ biodegradation efficiency could be due to the difference in the lipophilic degree related to cell binding. The presence of SAs did not significantly inhibit the biomass production of the consortium (1311-1952 mg/L biomass) but led to a 36-51% decrease in total polysaccharide content and an increase in microalgae's protein content, which caused granule formation. The presence of SMX and SDZ resulted in an increase in lipid peroxidation activity with a 6.2 and 23.5-fold increase in malondialdehyde content, respectively. Rhodobacter and Phreatobacter were abundant in the consortium with SAs' presence, while alinarimonas, Catalinimonas and Cecembia were seen in their absence.
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Affiliation(s)
- Yue Wang
- School of Materials and Environmental Engineering, Yantai University, Yantai 264005, China
| | - Jinghua Li
- School of Materials and Environmental Engineering, Yantai University, Yantai 264005, China
| | - Yao Lei
- School of Materials and Environmental Engineering, Yantai University, Yantai 264005, China
| | - Xiaoqiang Li
- School of Materials and Environmental Engineering, Yantai University, Yantai 264005, China
| | - Dillirani Nagarajan
- Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan; Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan
| | - Duu-Jong Lee
- Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan; Department of Mechanical Engineering, City University of Hong Kong, Kowloon Tang, Hong Kong
| | - Jo-Shu Chang
- Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan; Department of Chemical and Materials Engineering, Tunghai University, Taichung 407, Taiwan; Research Center for Smart Sustainable Circular Economy, Tunghai University, Taichung 407, Taiwan.
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7
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Giri DD, Dwivedi H, Khalaf D Alsukaibi A, Pal DB, Otaibi AA, Areeshi MY, Haque S, Gupta VK. Sustainable production of algae-bacteria granular consortia based biological hydrogen: New insights. BIORESOURCE TECHNOLOGY 2022; 352:127036. [PMID: 35331885 DOI: 10.1016/j.biortech.2022.127036] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 03/15/2022] [Accepted: 03/17/2022] [Indexed: 06/14/2023]
Abstract
Microbes recycling nutrient and detoxifying ecosystems are capable to fulfil the future energy need by producing biohydrogen by due to the coupling of autotrophic and heterotrophic microbes. In granules microbes mutualy exchanging nutrients and electrons for hydrogen production. The consortial biohydrogen production depend upon constituent microbes, their interdependence, competition for resources, and other operating parameters while remediating a waste material in nature or bioreactor. The present review deals with development of granular algae-bacteria consortia, hydrogen yield in coculture, important enzymes and possible engineering for improved hydrogen production.
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Affiliation(s)
- Deen Dayal Giri
- Department of Botany, Maharaj Singh College, Saharanpur-247001,Uttar Pradesh, India
| | - Himanshu Dwivedi
- Department of Botany, Maharaj Singh College, Saharanpur-247001,Uttar Pradesh, India
| | | | - Dan Bahadur Pal
- Department of Chemical Engineering, Birla Institute of Technology, Mesra, Ranchi-835215, Jharkhand, India
| | - Ahmed Al Otaibi
- Department of Chemistry, College of Sciences, University of Ha'il, Ha'il 2440, Saudi Arabia
| | - Mohammed Y Areeshi
- Research and Scientific Studies Unit, College of Nursing, Jazan University, Jazan 45142, Saudi Arabia; Medical Laboratory Technology Department, College of Applied Medical Sciences, Jazan University, Jazan 45142, Saudi Arabia
| | - Shafiul Haque
- Research and Scientific Studies Unit, College of Nursing, Jazan University, Jazan 45142, Saudi Arabia; Bursa Uludağ University Faculty of Medicine,Görükle Campus, 16059, Nilüfer, Bursa, Turkey
| | - Vijai Kumar Gupta
- Center for Safe and Improved Food, SRUC, Kings Buildings, West Mains Road, Edinburgh, EH9 3JG, UK; Biorefining and Advanced Materials Research Center, SRUC, Kings Buildings, West Mains Road, Edinburgh, EH9 3JG, UK.
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8
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Chen G, Hu Z, Ebrahimi A, Johnson DR, Wu F, Sun Y, Shen R, Liu L, Wang G. Electrotaxis-mediated cell motility and nutrient availability determine Chlamydomonas microsphaera-surface interactions in bioelectrochemical systems. Bioelectrochemistry 2022; 143:107989. [PMID: 34735914 DOI: 10.1016/j.bioelechem.2021.107989] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 09/28/2021] [Accepted: 10/23/2021] [Indexed: 12/16/2022]
Abstract
Cell attachment onto electrode-forming biocathodes is a promising alternative to expensive catalysts used for electricity production in bioelectrochemical systems (BESs). Though BESs have been extensively studied for decades, the processes, underlying mechanisms, and determinant driving forces of microalgal biocathode formation remain largely unknown. In this study, we employed a model unicellular motile microalga, Chlamydomonas microsphaera, to investigate the microalgal attachment processes onto the electrode surface of a BES and to identify the determinant factors. Results showed that the initial attachment of C. micrrosphaera cells is determined by the applied external voltage rather than nutrient availability and occurs via electrotaxis-mediated cell motility. The subsequent development of the C. microsphaera biofilm is then increasingly determined by nutrient availability. Our results revealed that, in the absence of an external voltage, nutrient availability remains a dominant factor controlling the fate of the microalgal surface attachment and subsequent biofilm formation processes. Thus, our results show that electrotactic and chemotactic movements are crucial to facilitate the initial attachment and subsequent biofilm formation of C. microsphaera onto the electrode surfaces of BES. This study provides new insights into the mechanisms of microalgal surface attachment and biofilm formation processes on microalgal biocathodes, which hold great promise for improving the electrochemical properties of cathodes.
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Affiliation(s)
- Guowei Chen
- Department of Civil Engineering, Hefei University of Technology, Hefei 230009, China; Anhui Provincial Engineering Laboratory for Rural Water Environment and Resources, Hefei 230009, China; Anhui Province Key Laboratory of Industrial Wastewater and Environmental Treatment, Hefei 230024, China
| | - Zhen Hu
- Department of Civil Engineering, Hefei University of Technology, Hefei 230009, China
| | - Ali Ebrahimi
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - David R Johnson
- Department of Environmental Microbiology, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf 8600, Switzerland
| | - Fazhu Wu
- Department of Civil Engineering, Hefei University of Technology, Hefei 230009, China
| | - Yifeng Sun
- Department of Soil and Water Sciences, China Agricultural University, Beijing 100193, China
| | - Renhao Shen
- Department of Civil Engineering, Hefei University of Technology, Hefei 230009, China
| | - Li Liu
- Department of Civil Engineering, Hefei University of Technology, Hefei 230009, China
| | - Gang Wang
- Department of Soil and Water Sciences, China Agricultural University, Beijing 100193, China.
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9
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Xu L, Zhou Z, Graham NJD, Liu M, Yu W. Enhancing ultrafiltration performance by gravity-driven up-flow slow biofilter pre-treatment to remove natural organic matters and biopolymer foulants. WATER RESEARCH 2021; 195:117010. [PMID: 33714912 DOI: 10.1016/j.watres.2021.117010] [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: 01/16/2021] [Revised: 03/02/2021] [Accepted: 03/03/2021] [Indexed: 06/12/2023]
Abstract
Membrane fouling by influent biopolymers, and the formation of surface biofilms, are major obstacles to the practical application of membrane technologies. Identifying reliable and sustainable pre-treatment methods for membrane filtration remains a considerable challenge and is the subject of continuing research study worldwide. Herein, the performance of a bench-scale gravity-driven up-flow slow biofilter (GUSB) as the pre-treatment for ultrafiltration to reduce membrane fouling is presented. Dissolved organic carbon (DOC) was shown efficiently removed by the GUSB (around 80%) when treating a natural water influent. More significantly, biopolymers, with molecular weight (MW) between 20 kDa and 100 kDa, were effectively removed (62.8% reduction) and this led to a lower rate of transmembrane pressure (TMP) development by the UF membrane. Microbial diversity analysis further unraveled the function of GUSB in shaping microbes to degrade biopolymers, contributing to lower accumulation and different distribution pattern of SMP on the membrane surface. Moreover, the biofilm formed on the membrane surface after the pre-treatment of GUSB was observed to have a relative porous structure compared to the control system, which can also affect the fouling development. Long-term operation of GUSB further revealed its robust performance in reducing both natural organic matters and UF fouling propensity. This study overall has demonstrated the potential advantages of applying a GUSB to enhance UF process performance by reducing biofouling and improving effluent quality.
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Affiliation(s)
- Lei Xu
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
| | - Zheng Zhou
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Nigel J D Graham
- Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom.
| | - Mengjie Liu
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Wenzheng Yu
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
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10
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Cheng Q, Liu Z, Huang Y, Li F, Nengzi L, Zhang J. Influence of temperature on COD Mn and Mn 2+ removal and microbial community structure in pilot-scale biofilter. BIORESOURCE TECHNOLOGY 2020; 316:123968. [PMID: 32781387 DOI: 10.1016/j.biortech.2020.123968] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 07/28/2020] [Accepted: 08/02/2020] [Indexed: 06/11/2023]
Abstract
Test water temperature (TWT) is a significant operational parameter in biofilter. In this study, a pilot-scale biofilter was established to investigate the removal efficiency of CODMn and Mn2+ and the microbial community structure at different TWT. When CODMn and Mn2+ in the influent were 6-8 and 0.9-1.2 mg/L, respectively, the removal rates were 22.61% and 94.28% at the low TWT, while 69.42% and 97.85% at the high TWT, respectively. Biological CODMn and Mn2+ removal followed the first-order reaction, and at the low and high TWT, the k value was 0.00704 and 0.0738 and 0.0313 and 0.113 min-1, respectively. Organic matter oxidizing bacteria (OMOB, Sphingopyxis, Sphingomonas, Amphiplicatus, Novosphingobium, Gemmatimonas, Chryseolinea and Sphingobium) and manganese oxidizing bacteria (MnOB, Hyphomicrobium, Pedomicrobium and Pseudomonas) were coexisted in 0-1.5 m of the biofilter bed at the low and high TWT, and the abundances were not the main factor affecting the removal efficiency, however the activity.
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Affiliation(s)
- Qingfeng Cheng
- College of Resources and Environment, Chengdu University of Information Technology, Chengdu 610225, PR China.
| | - Zongyang Liu
- College of Resources and Environment, Chengdu University of Information Technology, Chengdu 610225, PR China
| | - Yang Huang
- College of Resources and Environment, Chengdu University of Information Technology, Chengdu 610225, PR China
| | - Fengjiao Li
- College of Resources and Environment, Chengdu University of Information Technology, Chengdu 610225, PR China
| | - Lichao Nengzi
- College of Resources and Environment, Xichang University, Xichang 615000, PR China
| | - Jie Zhang
- State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, PR China
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