1
|
Tian H, Liu J, Zhang Y, Liu Q. Stress response and signalling of a low-temperature bioaugmentation system in decentralized wastewater treatment: Degradation characteristics, community structure, and bioaugmented mechanisms. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 342:118257. [PMID: 37290305 DOI: 10.1016/j.jenvman.2023.118257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 05/16/2023] [Accepted: 05/23/2023] [Indexed: 06/10/2023]
Abstract
Low temperatures present challenges for stable wastewater treatment operations in cold regions. Low-temperature effective microorganisms (LTEM) were added as a bioaugmentation strategy at a decentralized treatment facility to improve performance. The effects of a low-temperature bioaugmentation system (LTBS) with LTEM at low temperatures (4 °C) on organic pollutant performance, microbial community changes, and the metabolic pathways of functional genes and functional enzymes were studied. To explore the bioaugmentation mechanism of LTBS based on stress response and signalling. The results showed that the start-up time of the LTBS (S2) with LTEM was shorter (8 days) and that it removed COD and NH4+-N at higher rates (87 % and 72 %, respectively) at 4 °C. LTEM effectively degraded complex macromolecular organics into small molecular organics, and decomposing sludge flocs and the changing the extracellular polymeric substances (EPS) structure removed more organics and nitrogen. LTEM and local microbial communities (nitrifying and denitrifying bacteria) improved the ability of organic matter degradation and denitrification of the LTBS and formed a core microbial community dominated by LTEM (Bacillus and Pseudomonas). Finally, based on the functional enzymes and metabolic pathways of the LTBS, a low-temperature strengthening mechanism consisting of 6 cold stress responses and signal pathways under low temperatures was formed. This study demonstrated that the LTEM-dominated LTBS could provide an engineering alternative for future decentralized wastewater treatment in cold regions.
Collapse
Affiliation(s)
- Hongyu Tian
- School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China; Key Laboratory of Urban Stormwater System and Water Environment (Beijing University of Civil Engineering and Architecture), Ministry of Education, Beijing, 100044, China
| | - Jianwei Liu
- Beijing Engineering Research Center of Sustainable Urban Sewage System Construction and Risk Control, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China; Key Laboratory of Urban Stormwater System and Water Environment (Beijing University of Civil Engineering and Architecture), Ministry of Education, Beijing, 100044, China.
| | - Yuxiu Zhang
- School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China.
| | - Qianqian Liu
- School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China
| |
Collapse
|
2
|
Gao Z, Chen H, Wang Y, Lv Y. Advances in AHLs-mediated quorum sensing system in wastewater biological nitrogen removal: mechanism, function, and application. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2022; 86:1927-1943. [PMID: 36315086 DOI: 10.2166/wst.2022.305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Biological nitrogen removal process is to convert organic nitrogen and ammonia nitrogen into nitrogen via a series of reactions by microorganisms, and is widely used in wastewater treatment for its costless, high-effective, secondary pollution-free characteristics. Quorum sensing (QS) is a communication mode for microorganisms to regulate bacteria's physiological behaviors in response to environmental changes. N-acyl-homoserine lactones (AHLs)-mediated QS system is widespread in nitrogen removal-related functional bacteria and promotes biological nitrogen removal performance by regulating bacteria behavior. Recently, there has been an increasingly investigated AHLs-mediated QS system in wastewater biological nitrogen removal process. Consequently, the AHLs-mediated QS system is considered a promising regulatory strategy in the biological nitrogen removal process. This article reviewed the QS mechanism in various nitrogen removal-related functional bacteria and analyzed its effect on biological nitrogen removal performance. Combined with the application research of the QS system for enhanced biological nitrogen removal, it further put forward some prospects and suggestions which are of practical significance in practical application.
Collapse
Affiliation(s)
- Zhixiang Gao
- State Key Laboratory of Clean and Efficient Coal Utilization, Taiyuan University of Technology, Taiyuan 030024, China E-mail:
| | - Hu Chen
- College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China; Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering, Taiyuan 030024, China
| | - Ying Wang
- State Key Laboratory of Clean and Efficient Coal Utilization, Taiyuan University of Technology, Taiyuan 030024, China E-mail: ; Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering, Taiyuan 030024, China
| | - Yongkang Lv
- State Key Laboratory of Clean and Efficient Coal Utilization, Taiyuan University of Technology, Taiyuan 030024, China E-mail: ; Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering, Taiyuan 030024, China
| |
Collapse
|
3
|
Weng X, Mao Z, Fu HM, Chen YP, Guo JS, Fang F, Xu XW, Yan P. Biofilm formation during wastewater treatment: Motility and physiological response of aerobic denitrifying bacteria under ammonia stress based on surface plasmon resonance imaging. BIORESOURCE TECHNOLOGY 2022; 361:127712. [PMID: 35908635 DOI: 10.1016/j.biortech.2022.127712] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 07/24/2022] [Accepted: 07/26/2022] [Indexed: 06/15/2023]
Abstract
A bacterial image analysis system based on surface plasmon resonance imaging was established to investigate the effect of bacterial motility on biofilm formation under high ammonia nitrogen at the single-cell level. The results showed that the bacterial mean rotation speed and vertical motility distance decreased with the increasing concentration of ammonia nitrogen. Ammonia nitrogen inhibited the metabolic activity of the bacteria, decreasing bacterial motility. Bacterial motility was negatively correlated with the biofilm-formation ability. The biofilm formation ability of Enterobacter cloacae strain HNR exposed to ammonia nitrogen was enhanced by reducing its movement and promoting EPS secretion. Genes related to the tricarboxylic acid cycle and oxidative phosphorylation were down-regulated, indicating inhibition of microbial energy metabolism. Genes related to bacterial secretion and lipopolysaccharide synthesis were up-regulated, facilitating the formation of biofilms and enabling the bacteria to resist ammonia nitrogen stress. This study provides new insights into the biofilm formation under ammonia stress.
Collapse
Affiliation(s)
- Xun Weng
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China; College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Zheng Mao
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China; College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Hui-Min Fu
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China; College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - You-Peng Chen
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China; College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Jin-Song Guo
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China; College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Fang Fang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China; College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Xiao-Wei Xu
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China; College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Peng Yan
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China; College of Environment and Ecology, Chongqing University, Chongqing 400045, China.
| |
Collapse
|
4
|
Zulkifli M, Abu Hasan H, Sheikh Abdullah SR, Muhamad MH. A review of ammonia removal using a biofilm-based reactor and its challenges. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 315:115162. [PMID: 35561462 DOI: 10.1016/j.jenvman.2022.115162] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 04/16/2022] [Accepted: 04/22/2022] [Indexed: 06/15/2023]
Abstract
Extensive growth of industries leads to uncontrolled ammonia releases to environment. This can result in significant degradation of the aquatic ecology as well as significant health concerns for humans. Knowing the mechanism of ammonia elimination is the simplest approach to comprehending it. Ammonia has been commonly converted to less hazardous substances either in the form of nitrate or nitrogen gas. Ammonia has been converted into nitrite by ammonia-oxidizing bacteria and further reduced to nitrate by nitrite-oxidizing bacteria in aerobic conditions. Denitrification takes place in an anoxic phase and nitrate is converted into nitrogen gas. It is challenging to remove ammonia by employing technologies that do not incur particularly high costs. Thus, this review paper is focused on biofilm reactors that utilize the nitrification process. Many research publications and patents on biofilm wastewater treatment have been published. However, only a tiny percentage of these projects are for full-scale applications, and the majority of the work was completed within the last few decades. The physicochemical approaches such as ammonia adsorption, coagulation-flocculation, and membrane separation, as well as conventional biological treatments including activated sludge, microalgae, and bacteria biofilm, are briefly addressed in this review paper. The effectiveness of biofilm reactors in removing ammonia was compared, and the microbes that effectively remove ammonia were thoroughly discussed. Overall, biofilm reactors can remove up to 99.7% ammonia from streams with a concentration in range of 16-900 mg/L. As many challenges were identified for ammonia removal using biofilm at a commercial scale, this study offers future perspectives on how to address the most pressing biofilm issues. This review may also improve our understanding of biofilm technologies for the removal of ammonia as well as polishing unit in wastewater treatment plants for the water reuse and recycling, supporting the circular economy concept.
Collapse
Affiliation(s)
- Maryam Zulkifli
- Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia.
| | - Hassimi Abu Hasan
- Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia; Research Centre for Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia.
| | - Siti Rozaimah Sheikh Abdullah
- Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia; Research Centre for Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia.
| | - Mohd Hafizuddin Muhamad
- Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia.
| |
Collapse
|
5
|
Fu HM, Wang J, Ren H, Ding L. Acceleration of start-up of moving bed biofilm reactor at low temperature by adding specialized quorum sensing bacteria. BIORESOURCE TECHNOLOGY 2022; 358:127249. [PMID: 35500834 DOI: 10.1016/j.biortech.2022.127249] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/25/2022] [Accepted: 04/27/2022] [Indexed: 06/14/2023]
Abstract
This study aims to accelerate biofilm formation and operational performance of moving bed biofilm reactor (MBBR) at 5 ℃ by adding specialized Quorum Sensing bacteria (sphingomonas rubra BH3T). Results showed that bio augmented MBBR (RS) achieved a higher chemical oxygen demand and NH4+-N removal rate (93% and 75%), which in accordance with its increased biofilm thickness, higher biofilm activity, and nitrifying bacteria abundance (Nitrospira). The increased biofilm thickness (60.23 %) during the whole operating time, accompanied by more potent adhesion force (61.59 %), was related to increased polysaccharides and proteins in the biofilm. Pyrosequencing analysis indicated that BH3T contributed to higher species richness and triggered the rapid growth of precursor microorganisms (Nakamurella, Micropruina, and Zoogloea) and the enrichment of multifunctional microorganisms (Pseudomonas, Aeromonas, Arcobacter, Dechloromonas, and Flavobacterium) at low temperatures. This study provides an economical and practical new insight into accelerating start-up of MBBR system at low temperature.
Collapse
Affiliation(s)
- Hui-Min Fu
- 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
| | - Lili Ding
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China.
| |
Collapse
|
6
|
Chattopadhyay I, J RB, Usman TMM, Varjani S. Exploring the role of microbial biofilm for industrial effluents treatment. Bioengineered 2022; 13:6420-6440. [PMID: 35227160 PMCID: PMC8974063 DOI: 10.1080/21655979.2022.2044250] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Biofilm formation on biotic or abiotic surfaces is caused by microbial cells of a single or heterogeneous species. Biofilm protects microbes from stressful environmental conditions, toxic action of chemicals, and antimicrobial substances. Quorum sensing (QS) is the generation of autoinducers (AIs) by bacteria in a biofilm to communicate with one other. QS is responsible for the growth of biofilm, synthesis of exopolysaccharides (EPS), and bioremediation of environmental pollutants. EPS is used for wastewater treatment due to its three-dimensional matrix which is composed of proteins, polysaccharides, humic-like substances, and nucleic acids. Autoinducers mediate significantly the degradation of environmental pollutants. Acyl-homoserine lactone (AHL) producing bacteria as well as quorum quenching enzyme or bacteria can effectively improve the performance of wastewater treatment. Biofilms-based reactors due to their economic and ecofriendly nature are used for the treatment of industrial wastewaters. Electrodes coated with electro-active biofilm (EAB) which are obtained from sewage sludge, activated sludge, or industrial and domestic effluents are getting popularity in bioremediation. Microbial fuel cells are involved in wastewater treatment and production of energy from wastewater. Synthetic biological systems such as genome editing by CRISPR-Cas can be used for the advanced bioremediation process through modification of metabolic pathways in quorum sensing within microbial communities. This narrative review discusses the impacts of QS regulatory approaches on biofilm formation, extracellular polymeric substance synthesis, and role of microbial community in bioremediation of pollutants from industrial effluents.
Collapse
Affiliation(s)
| | - Rajesh Banu J
- Department of Life Sciences, Central University of Tamil Nadu, Thiruvarur, India
| | - T M Mohamed Usman
- Department of Civil Engineering, PET Engineering College, Vallioor, Tirunelveli, India
| | - Sunita Varjani
- Paryavaran Bhavan, Gujarat Pollution Control Board, Gandhinagar, India
| |
Collapse
|
7
|
Salzmann RD, Ackerman JN, Cicek N. Pilot-scale, on-site investigation of crushed recycled glass as tertiary filter media for municipal lagoon wastewater treatment. ENVIRONMENTAL TECHNOLOGY 2022; 43:51-59. [PMID: 32463350 DOI: 10.1080/09593330.2020.1775711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 05/22/2020] [Indexed: 06/11/2023]
Abstract
ABSTRACTGlass recycling is a process that faces many obstacles, especially in the closed-loop context. Waste glass separation and transportation can become quite expensive, turning glass collection for remanufacture unfeasible. For this reason, it is important that alternative markets for waste glass are sought. This study evaluated crushed recycled glass as tertiary media in subsurface pilot-scale filters for on-site municipal wastewater treatment, using control sand media filters. Filters were operated over 128 days at a 24-h hydraulic retention time, treating secondary lagoon effluent from the rural municipality of Dunnottar, Manitoba, Canada. Crushed recycled glass filters removed 92%, 90% and 45% of the total suspended solids (TSS), ammonium nitrogen (NH4+-N) and chemical oxygen demand (COD), respectively. Total suspended solids were removed equally well in sand and crushed recycled glass filters (α = 0.05), whereas NH4+-N and COD reductions were 10% and 21% greater in sand media, respectively. Both sand and crushed recycled glass filters failed to achieve phosphorus (P) discharge guidelines. This study shows that there is potential for crushed recycled glass in wastewater filtration, especially to achieve TSS, COD and NH4+-N removal. Small communities served by waste stabilization ponds could benefit from glass media filters, as waste glass could be diverted from curbside collection and utilized locally to polish municipal lagoon effluent.
Collapse
Affiliation(s)
- Rena D Salzmann
- Department of Biosystems Engineering, University of Manitoba, Winnipeg, Canada
| | - Joe N Ackerman
- Department of Biosystems Engineering, University of Manitoba, Winnipeg, Canada
| | - Nazim Cicek
- Department of Biosystems Engineering, University of Manitoba, Winnipeg, Canada
| |
Collapse
|
8
|
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.
Collapse
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:
| |
Collapse
|
9
|
Liu T, Xu J, Tian R, Quan X. Enhanced simultaneous nitrification and denitrification via adding N-acyl-homoserine lactones (AHLs) in integrated floating fixed-film activated sludge process. Biochem Eng J 2021. [DOI: 10.1016/j.bej.2020.107884] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
10
|
Wang S, Zhi L, Shan W, Lu H, Xu Q, Li J. Correlation of extracellular polymeric substances and microbial community structure in denitrification biofilm exposed to adverse conditions. Microb Biotechnol 2020; 13:1889-1903. [PMID: 32700468 PMCID: PMC7533329 DOI: 10.1111/1751-7915.13633] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Accepted: 07/01/2020] [Indexed: 01/24/2023] Open
Abstract
Microbial community may respond to different adverse conditions and result in the variation of extracellular polymeric substances (EPS) in denitrification biofilm; this study discovered the role of EPS in accordance with the analysis of cyclic diguanylate (c-di-GMP) and electron equilibrium (EE) under low organic loading rate, shock organic loading rate and low temperature conditions. Good nitrate removal performance could be achieved under shock organic loading rate and low temperature conditions; however, owing to the low organic loading rate, the carbon source was preferentially utilized for biomass growth. Tightly bound EPS (TB-EPS) contents progressively increased and facilitated cell adhesion and biofilm formation. The stable TB protein (TB-PN) content in TB-EPS built a cross-linked network to maintain internal biofilm structure and led to the rapid biosynthesis of polysaccharides, which could further enhance microbial adhesion and improve nitrate removal. C-di-GMP played an important role in biomass retention and biofilm formation, based on the correlation analysis of c-di-GMP and EPS. TB polysaccharide (TB-PS) contents presented a significant positive correlation with c-di-GMP content, microbial adhesion and biofilm stabilization was further enhanced through c-di-GMP regulation. In addition, a remarkable negative correlation between electron deletion rate (EDR) and TB-PN and TB-PS was discovered, and TB-PS was required to serve as energy source to enhance denitrification according to EE analysis. Surprisingly, dynamic microbial community was observed due to the drastic community succession under low temperature conditions, and the discrepancy between the dominant species for denitrification was found under shock organic loading rate and low temperature conditions. The notable increase in bacterial strains Simlicispira, Pseudomonas and Chryseobacterium was conducive to biofilm formation and denitrification under shock organic loading rate, while Dechloromonas and Zoogloea dramatically enriched for nitrate removal under low temperature conditions. The high abundance of Dechloromonas improved the secretion of EPS through the downstream signal transduction, and the c-di-GMP conserved in Pseudomonas concurrently facilitated to enhance exopolysaccharide production to shock organic loading rate and low temperature conditions.
Collapse
Affiliation(s)
- Shuo Wang
- Jiangsu Key Laboratory of Anaerobic BiotechnologySchool of Environment and Civil EngineeringJiangnan UniversityWuxi214122China
- Jiangsu Engineering Laboratory for Biomass Energy and Carbon Reduction TechnologyJiangnan UniversityWuxi214122China
- Jiangsu College of Water Treatment Technology and Material Collaborative Innovation CenterSuzhou215009China
- Department of Civil EngineeringSchulich School of EngineeringUniversity of CalgaryCalgaryT2N 1N4Canada
| | - Liling Zhi
- Jiangsu Key Laboratory of Anaerobic BiotechnologySchool of Environment and Civil EngineeringJiangnan UniversityWuxi214122China
| | - Wei Shan
- Jiangsu Key Laboratory of Anaerobic BiotechnologySchool of Environment and Civil EngineeringJiangnan UniversityWuxi214122China
| | - Hui Lu
- School of Environmental Science and EngineeringSun Yat‐sen UniversityGuangzhou510006China
| | - Qiao Xu
- Jiangsu Key Laboratory of Anaerobic BiotechnologySchool of Environment and Civil EngineeringJiangnan UniversityWuxi214122China
| | - Ji Li
- Jiangsu Key Laboratory of Anaerobic BiotechnologySchool of Environment and Civil EngineeringJiangnan UniversityWuxi214122China
- Jiangsu Engineering Laboratory for Biomass Energy and Carbon Reduction TechnologyJiangnan UniversityWuxi214122China
- Jiangsu College of Water Treatment Technology and Material Collaborative Innovation CenterSuzhou215009China
| |
Collapse
|
11
|
Wang S, Zou L, Li H, Zheng K, Wang Y, Zheng G, Li J. Full-scale membrane bioreactor process WWTPs in East Taihu basin: Wastewater characteristics, energy consumption and sustainability. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 723:137983. [PMID: 32222501 DOI: 10.1016/j.scitotenv.2020.137983] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 03/12/2020] [Accepted: 03/15/2020] [Indexed: 06/10/2023]
Abstract
Based on the collection and analysis of essential data from wastewater treatment plants (WWTPs) in recent ten years, the work provides the wastewater characteristics and energy consumption performance in full-scale membrane bioreactor (MBR) process in East Taihu basin, China. High-quality effluent was achieved although the influent carbon source was not beneficial to total nitrogen and total phosphorus removal. The average specific energy consumption (SEC) was 0.52 kWh/m3, which was remarkably lower than that of full-scale MBR process in developed countries, however, the average SEC value was higher than that of conventional activated sludge (CAS) process in China. In addition, the SEC value was largely reduced in 2018, and the regulation of suction pump and aeration mode were considered as the main control methods. Energy consumption will increase along with the influent volume, while the elevation of COD and NH4+-N reduction will bring about relatively low energy consumption. Furthermore, sustainability index was established to comprehensively evaluate the performance of full-scale MBR process, meaning that with relatively low permeate ratio of effluent, full-scale MBR process presented to be inferior to CAS process in sustainability and not feasible to be applied in the upgradation and construction of WWTPs.
Collapse
Affiliation(s)
- Shuo Wang
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China; Jiangsu College of Water Treatment Technology and Material Collaborative Innovation Center, Suzhou 215009, China; Department of Civil Engineering, Schulich School of Engineering, University of Calgary, Calgary T2N 1N4, Canada
| | - Luxi Zou
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China
| | - Huaibo Li
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China
| | - Kaikai Zheng
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China
| | - Yan Wang
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China
| | - Guochen Zheng
- Songliao River Basin Administration of Water Resources Protection, Changchun 130021, China
| | - Ji Li
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China; Jiangsu College of Water Treatment Technology and Material Collaborative Innovation Center, Suzhou 215009, China.
| |
Collapse
|
12
|
Fredendall RJ, Stone JL, Pehl MJ, Orwin PM. Transcriptome profiling of Variovorax paradoxus EPS under different growth conditions reveals regulatory and structural novelty in biofilm formation. Access Microbiol 2020; 2:acmi000121. [PMID: 32974586 PMCID: PMC7494200 DOI: 10.1099/acmi.0.000121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 02/07/2020] [Indexed: 12/15/2022] Open
Abstract
We used transcriptome analysis by paired-end strand-specific RNA-seq to evaluate the specific changes in gene expression associated with the transition to static biofilm growth in the rhizosphere plant growth-promoting bacterium Variovorax paradoxus EPS. Triplicate biological samples of exponential growth, stationary phase and static biofilm samples were examined. DESeq2 and Rockhopper were used to identify robust and widespread shifts in gene expression specific to each growth phase. We identified 1711 protein-coding genes (28%) using DESeq2 that had altered expression greater than twofold specifically in biofilms compared to exponential growth. Fewer genes were specifically differentially expressed in stationary-phase culture (757, 12%). A small set of genes (103/6020) were differentially expressed in opposing fashions in biofilm and stationary phase, indicating potentially substantial shifts in phenotype. Gene-ontology analysis showed that the only class of genes specifically upregulated in biofilms was associated with nutrient transport, highlighting the importance of nutrient uptake in the biofilm. The biofilm-specific genes did not overlap substantially with the loci identified by mutagenesis studies, although some were present in both sets. The most highly upregulated biofilm-specific gene is predicted to be a part of the RNA degradosome, which indicates that RNA stability is used to regulate the biofilm phenotype. Two small putative proteins, Varpa_0407 and Varpa_3832, are highly expressed specifically in biofilms and are predicted to be secreted DNA-binding proteins, which may stabilize extracellular DNA as a component of the biofilm matrix. An flp/tad type-IV pilus locus (Varpa_5148-60) is strongly downregulated specifically in biofilms, in contrast with results from other systems for these pili. Mutagenesis confirms that this locus is important in surface motility rather than biofilm formation. These experimental results suggest that V. paradoxus EPS biofilms have substantial regulatory and structural novelty.
Collapse
Affiliation(s)
- Richard J. Fredendall
- Biology Department, California State University San Bernardino, San Bernardino, CA, USA
| | - Jenny L. Stone
- Biology Department, California State University San Bernardino, San Bernardino, CA, USA
| | - Michael J. Pehl
- Biology Department, California State University San Bernardino, San Bernardino, CA, USA
| | - Paul M. Orwin
- Biology Department, California State University San Bernardino, San Bernardino, CA, USA
| |
Collapse
|
13
|
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.
Collapse
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.
| |
Collapse
|