201
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A novel screen-printed mast cell-based electrochemical sensor for detecting spoilage bacterial quorum signaling molecules (N-acyl-homoserine-lactones) in freshwater fish. Biosens Bioelectron 2018; 102:396-402. [DOI: 10.1016/j.bios.2017.11.040] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 10/23/2017] [Accepted: 11/10/2017] [Indexed: 12/30/2022]
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202
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Effect of fluctuating hydraulic retention time (HRT) on denitrification in the UASB reactors. Biochem Eng J 2018. [DOI: 10.1016/j.bej.2017.12.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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203
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Tang X, Guo Y, Wu S, Chen L, Tao H, Liu S. Metabolomics Uncovers the Regulatory Pathway of Acyl-homoserine Lactones Based Quorum Sensing in Anammox Consortia. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:2206-2216. [PMID: 29378137 DOI: 10.1021/acs.est.7b05699] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Acyl-homoserine lactones (AHLs)-mediated quorum sensing in bacterial communities have been extensively observed. However, the metabolic pathways regulated by AHLs in bacteria remain elusive. Here, we combined long-term reactor operation with microbiological and metabolomics analyses to explore the regulatory pathways for different AHLs in anammox consortia, which perform promising nitrogen removal for wastewater treatment. The results showed that no obvious shifts induced by exogenous AHLs occurred in the microbial community and, mainly, dosing AHLs induced changes in the metabolites. 3OC6-HSL, C6-HSL, and C8-HSL controlled the electron transport carriers that influence the bacterial activity. In contrast, only 3OC6-HSL regulated LysoPC(20:0) metabolism, which affected bacterial growth. AHLs mainly regulated the synthesis of the amino acids Ala, Val, and Glu and selectively regulated Asp and Leu to affect extracellular proteins. Simultaneously, all the AHLs regulated the ManNAc biosynthetic pathways, while OC6-HSL, OC8-HSL, and C6-HSL particularly enriched the UDP-GlcNAc pathway to promote exopolysaccharides, resulting in different aggregation levels of the anammox consortia. Our results not only provide the first metabolic insights into the means by which AHLs affect anammox consortia but also hint at potential strategies for overcoming the limitations of the long start-up period required for wastewater treatment by anammox processing.
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Affiliation(s)
- Xi Tang
- Key Laboratory of Water and Sediment Sciences, Ministry of Education of China , Beijing 100871, China
- College of Environmental Sciences and Engineering, Peking University , Beijing 100871, China
| | - Yongzhao Guo
- Key Laboratory of Water and Sediment Sciences, Ministry of Education of China , Beijing 100871, China
- School of Environment and Energy, Shenzhen Graduate School, Peking University , Shenzhen 518055, China
| | - Shanshan Wu
- Key Laboratory of Water and Sediment Sciences, Ministry of Education of China , Beijing 100871, China
- College of Environmental Sciences and Engineering, Peking University , Beijing 100871, China
| | - Liming Chen
- Key Laboratory of Water and Sediment Sciences, Ministry of Education of China , Beijing 100871, China
- College of Environmental Sciences and Engineering, Peking University , Beijing 100871, China
| | - Huchun Tao
- School of Environment and Energy, Shenzhen Graduate School, Peking University , Shenzhen 518055, China
| | - Sitong Liu
- Key Laboratory of Water and Sediment Sciences, Ministry of Education of China , Beijing 100871, China
- College of Environmental Sciences and Engineering, Peking University , Beijing 100871, China
- School of Environment and Energy, Shenzhen Graduate School, Peking University , Shenzhen 518055, China
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204
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Liébana R, Modin O, Persson F, Wilén BM. Integration of aerobic granular sludge and membrane bioreactors for wastewater treatment. Crit Rev Biotechnol 2018; 38:801-816. [PMID: 29400086 DOI: 10.1080/07388551.2017.1414140] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Environmental deterioration together with the need for water reuse and the increasingly restrictive legislation of water quality standards have led to a demand for compact, efficient and less energy consuming technologies for wastewater treatment. Aerobic granular sludge and membrane bioreactors (MBRs) are two technologies with several advantages, such as small footprint, high-microbial density and activity, ability to operate at high organic- and nitrogen-loading rates, and tolerance to toxicity. However, they also have some disadvantages. The aerobic granular sludge process generally requires post-treatment in order to fulfill effluent standards and MBRs suffer from fouling of the membranes. Integrating the two technologies could be a way of combining the advantages and addressing the main problems associated with both processes. The use of membranes to separate the aerobic granules from the treated water would ensure high-quality effluents suitable for reuse. Moreover, the use of granular sludge in MBRs has been shown to reduce fouling. Several recent studies have shown that the aerobic granular membrane bioreactor (AGMBR) is a promising hybrid process with many attractive features. However, major challenges that have to be addressed include how to achieve granulation and maintain granular stability during continuous operation of reactors. This paper aims to review the current state of research on AGMBR technology while drawing attention to relevant findings and highlight current limitations.
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Affiliation(s)
- Raquel Liébana
- a Division of Water Environment Technology, Department of Architecture and Civil Engineering , Chalmers University of Technology , Gothenburg , Sweden
| | - Oskar Modin
- a Division of Water Environment Technology, Department of Architecture and Civil Engineering , Chalmers University of Technology , Gothenburg , Sweden
| | - Frank Persson
- a Division of Water Environment Technology, Department of Architecture and Civil Engineering , Chalmers University of Technology , Gothenburg , Sweden
| | - Britt-Marie Wilén
- a Division of Water Environment Technology, Department of Architecture and Civil Engineering , Chalmers University of Technology , Gothenburg , Sweden
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205
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Wan X, Gao M, Ye M, Wang YK, Xu H, Wang M, Wang XH. Formation, characteristics and microbial community of aerobic granular sludge in the presence of sulfadiazine at environmentally relevant concentrations. BIORESOURCE TECHNOLOGY 2018; 250:486-494. [PMID: 29197771 DOI: 10.1016/j.biortech.2017.11.071] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 11/19/2017] [Accepted: 11/22/2017] [Indexed: 06/07/2023]
Abstract
The growing occurrence of antibiotics in water environment is causing increasing concern. To investigate the impact of frequently detected sulfadiazine on the formation of aerobic granular sludge, four sequencing batch reactors (SBRs) were set up with different environmentally relevant concentrations of sulfadiazine. Results showed that sulfadiazine pressure could lead to larger and more compact sludge particles and cause slight effect on reactor performance. Presence of sulfadiazine apparently increased the extracellular polymeric substances (EPS) secretion of microorganisms. Quantitative polymerase chain reaction (qPCR) showed that the abundances of sulfanilamide resistance genes in sludge increased with addition of sulfadiazine significantly. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) was used to predict functional genes, results showed that sulfadiazine led to an increase of specific functional genes. Thereby, it concluded that microorganisms could change the community structure by acclimating of functional bacteria and antibiotic resistance species to adapt to the antibiotic stress.
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Affiliation(s)
- Xiaoping Wan
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, China
| | - Mingming Gao
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, China
| | - Maosheng Ye
- China Eastern Route Corporation of South-to-North Water Diversion, Beijing 100038, China
| | - Yun-Kun Wang
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, China
| | - Hai Xu
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan 250100, China
| | - Mingyu Wang
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan 250100, China
| | - Xin-Hua Wang
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, China.
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206
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Wang J, Ding L, Li K, Huang H, Hu H, Geng J, Xu K, Ren H. Estimation of spatial distribution of quorum sensing signaling in sequencing batch biofilm reactor (SBBR) biofilms. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 612:405-414. [PMID: 28858750 DOI: 10.1016/j.scitotenv.2017.07.277] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 07/31/2017] [Accepted: 07/31/2017] [Indexed: 06/07/2023]
Abstract
Quorum sensing (QS) signaling, plays a significant role in regulating formation of biofilms in the nature; however, little information about the occurrence and distribution of quorum sensing molecular in the biofilm of carriers has been reported. In this study, distribution of QS signaling molecules (the acylated homoserine lactones-AHLs, and AI-2), extracellular polymeric substances (EPS) and the mechanical properties in sequencing batch biofilm reactor (SBBR) biofilms have been investigated. Using increased centrifugal force, the biofilms were detached into different fractions. The AHLs ranged from 5.2ng/g to 98.3ng/g in different fractions of biofilms, and N-decanoyl-dl-homoserine lactone (C10-HSL) and N-dodecanoyl-dl-homoserine lactone (C12-HSL) in the biofilms obtained at various centrifugal forces displayed significant differences (p<0.01). Interspecies communication signal autoinducer-2(AI-2) in the biofilms ranged from 79.2ng/g to 98.3ng/g. Soluble EPS and loosely bound EPS content in the different fractions of biofilms displayed significant positive relationship with the distribution of C12-HSL (r=0.86, p<0.05). Furthermore, 49.62% of bacteria in the biofilms were positively related with AHLs with 22.76% was significantly positively (p<0.05) related with AHLs. Biofilm adhesion and compliance was the strongest in the tightly-bound biofilm, the weakest in the supernatant/surface biofilm, which was in accordance with the distribution of C12 HSL(r=0.77, p<0.05) and C10-HSL(r=0.75, p<0.05), respectively. This study addressed on better understanding of possible methods for the improvement of wastewater bio-treatment through biofilm application.
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Affiliation(s)
- Jinfeng Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Lili Ding
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Kan Li
- 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
| | - Haidong Hu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Jinju 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
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China.
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207
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Abstract
One common feature of biofilm development is the active dispersal of cells from the mature biofilm, which completes the biofilm life cycle and allows for the subsequent colonization of new habitats. Dispersal is likely to be critical for species survival and appears to be a precisely regulated process that involves a complex network of genes and signal transduction systems. Sophisticated molecular mechanisms control the transition of sessile biofilm cells into dispersal cells and their coordinated detachment and release in the bulk liquid. Dispersal cells appear to be specialized and exhibit a unique phenotype different from biofilm or planktonic bacteria. Further, the dispersal population is characterized by a high level of heterogeneity, reminiscent of, but distinct from, that in the biofilm, which could potentially allow for improved colonization under various environmental conditions. Here we review recent advances in characterizing the molecular mechanisms that regulate biofilm dispersal events and the impact of dispersal in a broader ecological context. Several strategies that exploit the mechanisms controlling biofilm dispersal to develop as applications for biofilm control are also presented.
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208
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Nancharaiah YV, Kiran Kumar Reddy G. Aerobic granular sludge technology: Mechanisms of granulation and biotechnological applications. BIORESOURCE TECHNOLOGY 2018; 247:1128-1143. [PMID: 28985995 DOI: 10.1016/j.biortech.2017.09.131] [Citation(s) in RCA: 212] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 09/18/2017] [Accepted: 09/19/2017] [Indexed: 05/27/2023]
Abstract
Aerobic granular sludge (AGS) is a novel microbial community which allows simultaneous removal of carbon, nitrogen, phosphorus and other pollutants in a single sludge system. AGS is distinct from activated sludge in physical, chemical and microbiological properties and offers compact and cost-effective treatment for removing oxidized and reduced contaminants from wastewater. AGS sequencing batch reactors have shown their utility in the treatment of abattoir, live-stock, rubber, landfill leachate, dairy, brewery, textile and other effluents. AGS is extensively researched for wide-spread implementation in sewage treatment plants. However, formation of AGS takes relatively much longer time while treating low-strength wastewaters like sewage. Strategies like increased volumetric flow by means of short cycles and mixing of sewage with industrial wastewaters can promote AGS formation while treating low-strength sewage. This article reviewed the state of research on AGS formation mechanisms, bioremediation capabilities and biotechnological applications of AGS technology in domestic and industrial wastewater treatment.
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Affiliation(s)
- Y V Nancharaiah
- Biofouling and Biofilm Processes Section, Water and Steam Chemistry Division, Bhabha Atomic Research Centre, Kalpakkam 603102, Tamil Nadu, India; Homi Bhabha National Institute, Anushakti Nagar, Mumbai 400 094, India.
| | - G Kiran Kumar Reddy
- Biofouling and Biofilm Processes Section, Water and Steam Chemistry Division, Bhabha Atomic Research Centre, Kalpakkam 603102, Tamil Nadu, India; Homi Bhabha National Institute, Anushakti Nagar, Mumbai 400 094, India
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209
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Ma H, Wang X, Zhang Y, Hu H, Ren H, Geng J, Ding L. The diversity, distribution and function of N-acyl-homoserine lactone (AHL) in industrial anaerobic granular sludge. BIORESOURCE TECHNOLOGY 2018; 247:116-124. [PMID: 28946084 DOI: 10.1016/j.biortech.2017.09.043] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 09/05/2017] [Accepted: 09/06/2017] [Indexed: 06/07/2023]
Abstract
Although AHL-mediated quorum sensing (QS) signaling has been proved to be ecologically important in biofilm formation and aerobic granulation process, the biological role of AHL in anaerobic granule has not been experimentally investigated. In this paper, we explored the AHL level in 10 full-scale industrial anaerobic granular bioreactors and detected a total of 4 kinds of AHLs. C8-HSL and C10-HSL were indicated to be the potentially universal QS signal molecules in anaerobic granules and involved in extracellular polymeric substance (EPS) production and granulation process. The add-back experiments further supported the hypothesis that C8-HSL and C10-HSL might play an important role in facilitating anaerobic granulation through regulation of EPS synthesis. 12 Microorganisms might be regulated by AHL to play an important role in EPS production. This study provides a foundation for exploring the function of AHL in anaerobic granular systems, which may shed light on advanced AHL-based anaerobic granulation strategy.
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Affiliation(s)
- Haijun Ma
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Xuezhu Wang
- 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
| | - Haidong Hu
- 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.
| | - Jinju Geng
- 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
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210
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Świątczak P, Cydzik-Kwiatkowska A. Performance and microbial characteristics of biomass in a full-scale aerobic granular sludge wastewater treatment plant. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:1655-1669. [PMID: 29101689 PMCID: PMC5766719 DOI: 10.1007/s11356-017-0615-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 10/24/2017] [Indexed: 05/27/2023]
Abstract
By modification of the operational conditions of batch reactors, a municipal wastewater treatment plant was upgraded from activated sludge to aerobic granular sludge (AGS) technology. After upgrading, the volume of the biological reactors was reduced by 30%, but the quality of the effluent substantially improved. The concentration of biomass in the reactors increased twofold; the average biomass yield was 0.6 g MLVSS/g COD, and excess granular sludge was efficiently stabilized in aerobic conditions. Canonical correspondence analysis based on the results of next-generation sequencing showed that the time of adaptation significantly influenced the microbial composition of the granules. In mature granules, the abundance of ammonium-oxidizing bacteria was very low, while the abundance of the nitrite-oxidizing bacteria Nitrospira sp. was 0.5 ± 0.1%. The core genera were Tetrasphaera, Sphingopyxis, Dechloromonas, Flavobacterium, and Ohtaekwangia. Bacteria belonging to these genera produce extracellular polymeric substances, which stabilize granule structure and accumulate phosphorus. The results of this study will be useful for designers of AGS wastewater treatment plants, and molecular data given here provide insight into the ecology of mature aerobic granules from a full-scale facility.
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Affiliation(s)
- Piotr Świątczak
- Department of Environmental Biotechnology, University of Warmia and Mazury in Olsztyn, Sloneczna 45G, 10-709, Olsztyn, Poland
| | - Agnieszka Cydzik-Kwiatkowska
- Department of Environmental Biotechnology, University of Warmia and Mazury in Olsztyn, Sloneczna 45G, 10-709, Olsztyn, Poland.
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211
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Chen H, Li A, Cui D, Wang Q, Wu D, Cui C, Ma F. N-Acyl-homoserine lactones and autoinducer-2-mediated quorum sensing during wastewater treatment. Appl Microbiol Biotechnol 2017; 102:1119-1130. [DOI: 10.1007/s00253-017-8697-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 12/04/2017] [Accepted: 12/06/2017] [Indexed: 12/16/2022]
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212
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Xu J, Zhang H, Zhao R, Kong F. Enhanced bacterial quorum aggregation on a zeolite capping layer for sustainable inhibition of ammonium release from contaminated sediment. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2017; 76:3428-3440. [PMID: 29236021 DOI: 10.2166/wst.2017.507] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The main objective of this study was to investigate how signal molecules enhance bacterial quorum aggregation on a zeolite capping layer for sustainable inhibition of ammonium release from contaminated sediment. Sediment remediation experiments were carried out by using nitrifying bacteria (WGX10, WGX18), denitrifying bacteria (HF3, HF7) and two kinds of signal molecules (OHHL, C8-HSL). The results showed that nitrifying bacteria and denitrifying bacteria could significantly aggregate on zeolite after adding 1.0 μM OHHL at a C/N ratio of 7. The maximum ammonium removal of five times the amount of ammonium adsorbed was achieved when 1.0 μM OHHL was added at the C/N ratio of 7 (the bio-regeneration rate was up to 88.32%), which was 1.24-2.02 times the ammonium removal amount at C/N ratios of 3, 5, 9. The concentration of total nitrogen in the overlying water was no more than 0.8 mg/L during four rounds of sediment remediation experiments. In addition, the bio-regeneration rate was up to 71.20%, which achieved sustainable inhibition of ammonium release from contaminated sediment.
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Affiliation(s)
- Jinlan Xu
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi Province 710055, China and Key Laboratory of Northwest Water Resources, Environment and Ecology, MOE Xi'an, Shaanxi Province 710055, China E-mail:
| | - Haiyang Zhang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi Province 710055, China and Key Laboratory of Northwest Water Resources, Environment and Ecology, MOE Xi'an, Shaanxi Province 710055, China E-mail:
| | - Rong Zhao
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi Province 710055, China and Key Laboratory of Northwest Water Resources, Environment and Ecology, MOE Xi'an, Shaanxi Province 710055, China E-mail:
| | - Fanxing Kong
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi Province 710055, China and Key Laboratory of Northwest Water Resources, Environment and Ecology, MOE Xi'an, Shaanxi Province 710055, China E-mail:
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213
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Ding Y, Feng H, Shen D, Li N, Wang M, Zhou Y. The effect of organic shock loads on the stability of anaerobic granular sludge. ENVIRONMENTAL TECHNOLOGY 2017; 38:3026-3033. [PMID: 28151054 DOI: 10.1080/09593330.2017.1286388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 12/23/2016] [Indexed: 06/06/2023]
Abstract
UNLABELLED This study investigated the effect of organic shock loads on the stability of anaerobic granular sludge (AnGS). At double and triple shock intensity (8 and 12 kg COD/m3d organic loading rate (OLR), respectively), the accumulation of volatile fatty acids resulted in the decreasing pH of the reactors. The unstable performances of AnGS also appeared in the macroscopic properties, including the decreasing contents of relative hydrophobicity (RH), granular strength and diameter, and the fluctuation of EPS production. Noteworthily, the contents of loosely bound and tightly bound polysaccharide increased obviously and were higher than that in the control under double and triple OLR shock load. However, the growing trend of protein content was only found in the double OLR shock reactor. In addition, the N-hexanoyl-homoserine lactone (C6-HSL) content increased following the shock and then decreased during the recovery. The autoinducer-2 (AI-2) content gradually decreased under OLR shock conditions, and then rapidly increased during the recovery phase. The behaviour of the diffusible signal factor (DSF) was opposite that of AI-2. The combination of C6-HSL, AI-2 and DSF had a degraded effect on the properties of AnGS. The results provide a new reference for further research into the inter-effects among multiple signal molecules in anaerobic sludge. ABBREVIATIONS 3-oxo-C6-HSL: N-3-oxo-hexanoyl-homoserine lactone; AHLs: acyl-homoserine lactone; AI-2: auto-inducers-2; AnGS: anaerobic granular sludge; C4-HSL: N-hydroxybutanoyl-homoserine lactone; C6-HSL: N-hexanoyl-homoserine lactone; COD: chemical oxygen demand; DSF: diffusible signal factor; EPS: extracellular polymeric substance; HPLC: High-performance liquid chromatography; HRT: hydraulic retention time; IC: integrity coefficient; LB-: loosely bound; MLSS: mixed liquor suspended solids; MLVSS: mixed liquor volatile suspended solids; OLR: organic loading rate; PN: protein; PS: polysaccharide; QS: quorum sensing; RH: Relative hydrophobicity; SS: suspended solids; TB-: tightly bound; UPLC-MS/MS: ultra-performance liquid chromatography-tandem mass spectrometry; VFAs: volatile fatty acids.
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Affiliation(s)
- Yangcheng Ding
- a Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling , Zhejiang Gongshang University , Hangzhou , People's Republic of China
| | - Huajun Feng
- a Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling , Zhejiang Gongshang University , Hangzhou , People's Republic of China
| | - Dongsheng Shen
- a Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling , Zhejiang Gongshang University , Hangzhou , People's Republic of China
| | - Na Li
- a Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling , Zhejiang Gongshang University , Hangzhou , People's Republic of China
| | - Meizhen Wang
- a Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling , Zhejiang Gongshang University , Hangzhou , People's Republic of China
| | - Yuyang Zhou
- a Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling , Zhejiang Gongshang University , Hangzhou , People's Republic of China
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214
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Li YS, Pan XR, Cao JS, Song XN, Fang F, Tong ZH, Li WW, Yu HQ. Augmentation of acyl homoserine lactones-producing and -quenching bacterium into activated sludge for its granulation. WATER RESEARCH 2017; 125:309-317. [PMID: 28866446 DOI: 10.1016/j.watres.2017.08.061] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 08/22/2017] [Accepted: 08/28/2017] [Indexed: 06/07/2023]
Abstract
Quorum sensing (QS), especially acyl homoserine lactone (AHL)-mediated QS, in activated sludge arouses great interests because of its vital role in the formation of biofilm and aerobic granules (AG). Although QS is reported to be largely related to the properties of activated sludge, it is not economically feasible to tune QS in an activated sludge reactor through dosing pure AHL or AHL hydrolase. A more reasonable way to tune QS is to augment reactors with AHL-producing or -quenching bacteria. In this work, the impacts of continuous dose of AHL-producing or -quenching strains on the activated sludge during its granulation process were explored. Augmentation of AHL-producing or -quenching strains resulted in up- or down-regulation of the AHL concentration in the reactors. Granulation of activated sludge was also accomplished in all reactors, but the granules showed negligible or slight differences in the physicochemical properties of sludge, such as nutrients removal, biomass concentration, extracellular polymeric substances, and zeta potential. Interestingly, a smaller granule size was observed for both the reactor augmented with either an AHL-quenching strain or an AHL-producing strain, suggesting that the AHL augmentation suppressed the biofilm development. Pyrosequencing analysis reveals that the granules cultured in the reactors varied widely in bacterial community structure, indicating that the AHL augmentation had a greater impact on the bacterial community structure, rather than on the physicochemical properties of activated sludge. These results demonstrate that the role of QS in the biofilm formation in complex wastewater treatment bioreactors should be re-evaluated.
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Affiliation(s)
- Yu-Sheng Li
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, China; CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei, China
| | - Xin-Rong Pan
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei, China
| | - Jia-Shun Cao
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, China
| | - Xiang-Ning Song
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei, China
| | - Fang Fang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, China
| | - Zhong-Hua Tong
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei, China
| | - Wen-Wei Li
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei, China
| | - Han-Qing Yu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei, China.
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215
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Matar GK, Bagchi S, Zhang K, Oerther DB, Saikaly PE. Membrane biofilm communities in full-scale membrane bioreactors are not randomly assembled and consist of a core microbiome. WATER RESEARCH 2017; 123:124-133. [PMID: 28658633 DOI: 10.1016/j.watres.2017.06.052] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 05/12/2017] [Accepted: 06/19/2017] [Indexed: 05/13/2023]
Abstract
Finding efficient biofouling control strategies requires a better understanding of the microbial ecology of membrane biofilm communities in membrane bioreactors (MBRs). Studies that characterized the membrane biofilm communities in lab-and pilot-scale MBRs are numerous, yet similar studies in full-scale MBRs are limited. Also, most of these studies have characterized the mature biofilm communities with very few studies addressing early biofilm communities. In this study, five full-scale MBRs located in Seattle (Washington, U.S.A.) were selected to address two questions concerning membrane biofilm communities (early and mature): (i) Is the assembly of biofilm communities (early and mature) the result of random immigration of species from the source community (i.e. activated sludge)? and (ii) Is there a core membrane biofilm community in full-scale MBRs? Membrane biofilm (early and mature) and activated sludge (AS) samples were collected from the five MBRs, and 16S rRNA gene sequencing was applied to investigate the bacterial communities of AS and membrane biofilms (early and mature). Alpha and beta diversity measures revealed clear differences in the bacterial community structure between the AS and biofilm (early and mature) samples in the five full-scale MBRs. These differences were mainly due to the presence of large number of unique but rare operational taxonomic units (∼13% of total reads in each MBR) in each sample. In contrast, a high percentage (∼87% of total reads in each MBR) of sequence reads was shared between AS and biofilm samples in each MBR, and these shared sequence reads mainly belong to the dominant taxa in these samples. Despite the large fraction of shared sequence reads between AS and biofilm samples, simulated biofilm communities from random sampling of the respective AS community revealed that biofilm communities differed significantly from the random assemblages (P < 0.001 for each MBR), indicating that the biofilm communities (early and mature) are unlikely to represent a random sample of the AS community. In addition to the presence of unique operational taxonomic units in each biofilm sample (early or mature), comparative analysis of operational taxonomic units and genera revealed the presence of a core biofilm community in the five full-scale MBRs. These findings provided insight into the membrane biofilm communities in full-scale MBRs. More comparative studies are needed in the future to elucidate the factors shaping the core and unique biofilm communities in full-scale MBRs.
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Affiliation(s)
- Gerald K Matar
- King Abdullah University of Science and Technology, Biological and Environmental Sciences and Engineering Division, Water Desalination and Reuse Research Center, Thuwal 23955-6900, Saudi Arabia
| | - Samik Bagchi
- King Abdullah University of Science and Technology, Biological and Environmental Sciences and Engineering Division, Water Desalination and Reuse Research Center, Thuwal 23955-6900, Saudi Arabia
| | - Kai Zhang
- Baswood Corporation, Allen, TX 75013, USA
| | - Daniel B Oerther
- Department of Civil, Architectural, and Environmental Engineering, And Environmental Research Center, Missouri University of Science and Technology, Rolla, MO 65409, USA
| | - Pascal E Saikaly
- King Abdullah University of Science and Technology, Biological and Environmental Sciences and Engineering Division, Water Desalination and Reuse Research Center, Thuwal 23955-6900, Saudi Arabia.
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216
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Szabó E, Liébana R, Hermansson M, Modin O, Persson F, Wilén BM. Comparison of the bacterial community composition in the granular and the suspended phase of sequencing batch reactors. AMB Express 2017; 7:168. [PMID: 28871435 PMCID: PMC5583138 DOI: 10.1186/s13568-017-0471-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 08/30/2017] [Indexed: 11/10/2022] Open
Abstract
Granulation of activated sludge is an increasingly important area within the field of wastewater treatment. Granulation is usually achieved by high hydraulic selection pressure, which results in the wash-out of slow settling particles. The effect of the harsh wash-out conditions on the granular sludge ecosystem is not yet fully understood, but different bacterial groups may be affected to varying degrees. In this study, we used high-throughput amplicon sequencing to follow the community composition in granular sludge reactors for 12 weeks, both in the granular phase and the suspended phase (effluent). The microbiome of the washed out biomass was similar but not identical to the microbiome of the granular biomass. Certain taxa (e.g. Flavobacterium spp. and Bdellovibrio spp.) had significantly (p < 0.05) higher relative abundance in the granules compared to the effluent. Fluorescence in situ hybridization images indicated that these taxa were mainly located in the interior of granules and therefore protected from erosion. Other taxa (e.g. Meganema sp. and Zooglea sp.) had significantly lower relative abundance in the granules compared to the effluent, and appeared to be mainly located on the surface of granules and therefore subject to erosion. Despite being washed out, these taxa were among the most abundant members of the granular sludge communities and were likely growing fast in the reactors. The ratio between relative abundance in the granular biomass and in the effluent did not predict temporal variation of the taxa in the reactors, but it did appear to predict the spatial location of the taxa in the granules.
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217
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Membrane fouling induced by AHL-mediated soluble microbial product (SMP) formation by fouling-causing bacteria co-cultured with fouling-enhancing bacteria. Sci Rep 2017; 7:8482. [PMID: 28814755 PMCID: PMC5559553 DOI: 10.1038/s41598-017-09023-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 07/14/2017] [Indexed: 11/24/2022] Open
Abstract
Membrane fouling still remains a major obstacle for wider applications of membrane bioreactor (MBR), which is mainly caused by soluble microbial products (SMP). Identification of key bacteria responsible for SMP production is essential for mitigation of membrane fouling. Here, we investigated the effect of microbial interaction on membrane fouling. We measured the membrane fouling potentials of 13 bacterial strains isolated from a pilot-scale MBR treating domestic wastewater when they were cultivated as single-culture and co-culture. We found that fouling-causing bacteria (FCB) displayed much higher fouling potential when co-cultured even with non-FCB and mixed population (activated sludge). In particular, the fouling potential of strain S26, one of FCB, increased 26.8 times when cultivated with strain S22 (fouling-enhancing bacteria, FEB). The secretion of N-octanoyl-L-homoserine lactone (C8-HSL) was increased by co-cultivating S22 and S26 as compared with cultivating as single culture, which stimulated the production of fouling-causing SMP by S26 and consequently resulted in severe membrane fouling. This result suggests that AHL-mediated quorum-sensing (QS) regulatory system was involved in secretion of fouling-causing SMP.
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218
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Guo Y, Liu S, Tang X, Wang C, Niu Z, Feng Y. Insight into c-di-GMP Regulation in Anammox Aggregation in Response to Alternating Feed Loadings. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:9155-9164. [PMID: 28737376 DOI: 10.1021/acs.est.6b06396] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Substrate concentrations generally fluctuate in wastewaters. However, how anammox biomass behaves to overcome the stress of alternating feed loadings remains unclear. Here, we combined long-term reactor operation, batch tests, 16S rRNA transcript sequencing, and metabolomics analysis to investigate the aggregation of anammox biomass under the regulation of c-di-GMP, a key second messenger, in response to alternating feed loadings. We demonstrated that the aggregation process was significantly faster under alternating loadings and was significantly correlated with higher levels of c-di-GMP and extracellular polymeric substances (EPS) production. The increase in c-di-GMP was positively correlated with a higher relative transcript expression level in the c-di-GMP pathway-dependent community. The targeted metabolomics results indicated that the increased production of fructose 6-phosphate and UDP-N-acetyl-d-glucosamine, the precursor substances for the synthesis of exopolysaccharides, was induced by higher levels of c-di-GMP. Consequently, the granulation process was accelerated via EPS production. Higher levels of intracellular hydrophobic amino acids were also positively correlated with increased extracellular protein levels, considering the significant increase in peptides under alternating loadings. On the basis of our findings, we believe that c-di-GMP regulation and EPS production of the anammox biomass are important mechanisms to enhance its tolerance against unfavorable feed stress. These results highlight the role of c-di-GMP in anammox biomass as it works to survive in unfavorable niches.
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Affiliation(s)
- Yongzhao Guo
- Key Laboratory of Water and Sediment Sciences, Ministry of Education of China, Peking University , Beijing 100871, China
- School of Environment and Energy, Peking University Shenzhen Graduate School , Shenzhen 518055, China
| | - Sitong Liu
- Key Laboratory of Water and Sediment Sciences, Ministry of Education of China, Peking University , Beijing 100871, China
- School of Environment and Energy, Peking University Shenzhen Graduate School , Shenzhen 518055, China
| | - Xi Tang
- Key Laboratory of Water and Sediment Sciences, Ministry of Education of China, Peking University , Beijing 100871, China
| | - Chao Wang
- Key Laboratory of Industrial Ecology and Environmental Engineering, School of Environmental Science and Technology, Dalian University of Technology , Dalian 116024, China
| | - Zhao Niu
- Key Laboratory of Water and Sediment Sciences, Ministry of Education of China, Peking University , Beijing 100871, China
- School of Environment and Energy, Peking University Shenzhen Graduate School , Shenzhen 518055, China
| | - Ying Feng
- Key Laboratory of Water and Sediment Sciences, Ministry of Education of China, Peking University , Beijing 100871, China
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219
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Shi Y, Huang J, Zeng G, Gu Y, Chen Y, Hu Y, Tang B, Zhou J, Yang Y, Shi L. Exploiting extracellular polymeric substances (EPS) controlling strategies for performance enhancement of biological wastewater treatments: An overview. CHEMOSPHERE 2017; 180:396-411. [PMID: 28419953 DOI: 10.1016/j.chemosphere.2017.04.042] [Citation(s) in RCA: 231] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 04/02/2017] [Accepted: 04/10/2017] [Indexed: 06/07/2023]
Abstract
Extracellular polymeric substances (EPS) are present both outside of the cells and in the interior of microbial aggregates, and account for a main component in microbial aggregates. EPS can influence the properties and functions of microbial aggregates in biological wastewater treatment systems, and specifically EPS are involved in biofilm formation and stability, sludge behaviors as well as sequencing batch reactors (SBRs) granulation whereas they are also responsible for membrane fouling in membrane bioreactors (MBRs). EPS exhibit dual roles in biological wastewater treatments, and hence the control of available EPS can be expected to lead to changes in microbial aggregate properties, thereby improving system performance. In this review, current updated knowledge with regard to EPS basics including their formation mechanisms, important properties, key component functions as well as sub-fraction differentiation is given. EPS roles in biological wastewater treatments are also briefly summarized. Special emphasis is laid on EPS controlling strategies which would have the great potential in promoting microbial aggregates performance and in alleviating membrane fouling, including limitation strategies (inhibition of quorum sensing (QS) systems, regulation of environmental conditions, enzymatic degradation of key components, energy uncoupling etc.) and elevation strategies (enhancement of QS systems, addition of exogenous agents etc.). Those strategies have been confirmed to be feasible and promising to enhance system performance, and they would be a research niche that deserves further study.
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Affiliation(s)
- Yahui Shi
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Jinhui Huang
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China.
| | - Guangming Zeng
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China.
| | - Yanling Gu
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Yaoning Chen
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Yi Hu
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Bi Tang
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Jianxin Zhou
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Ying Yang
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Lixiu Shi
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
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220
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Feng S, Tan CH, Constancias F, Kohli GS, Cohen Y, Rice SA. Predation by Bdellovibrio bacteriovorus significantly reduces viability and alters the microbial community composition of activated sludge flocs and granules. FEMS Microbiol Ecol 2017; 93:3044202. [PMID: 28334102 DOI: 10.1093/femsec/fix020] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 02/17/2017] [Indexed: 01/21/2023] Open
Abstract
We recently isolated and characterised a predatory Bdellovibrio bacteriovorus strain from activated sludge (Ulu Pandan Water Reclamation Plant, Singapore), and this strain, B. bacteriovorus UP, was able to prey upon a broad spectrum of bacterial isolates from the activated sludge when grown as planktonic cells or as biofilms. Here, we have tested the effect of Bdellovibrio predation on floccular and granular sludge to determine if the spatial organisation, loosely or tightly aggregated communities, was protective from predation. The effect of predation was assessed using a combination of biomass quantification, cellular activity measurement and microscopic image analysis to determine community viability. Additionally, changes in the microbial communities due to predation by B. bacteriovorus UP were analysed through total RNA sequencing. Predation led to a significant reduction in microbial activity and total biomass for both floccular and granular sludge communities. Predation was also associated with significant changes in the microbial community composition in both communities, with >90% of the community members reduced in relative abundance after 24 h. Of those community members, the dominant organisms, such as Proteobacteria and Bacteroidetes, were the most affected phylotypes. This suggests that predatory bacteria, which display indiscriminant feeding, could significantly shift the species composition and thus, may disturb the operational performance of wastewater treatment systems.
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Affiliation(s)
- Shugeng Feng
- The Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551, Singapore
| | - Chuan Hao Tan
- The Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551, Singapore.,The School of Materials Science and Engineering, Nanyang Technological University, Singapore 637551, Singapore
| | - Florentin Constancias
- The Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551, Singapore
| | - Gurjeet S Kohli
- The Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551, Singapore
| | - Yehuda Cohen
- The Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551, Singapore
| | - Scott A Rice
- The Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551, Singapore.,The School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore.,The Centre for Marine Bio-Innovation, The School of Biological, Earth and Environmental Sciences, The University of New South Wales, Sydney, NSW 2052, Australia
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221
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Utari PD, Vogel J, Quax WJ. Deciphering Physiological Functions of AHL Quorum Quenching Acylases. Front Microbiol 2017; 8:1123. [PMID: 28674525 PMCID: PMC5474475 DOI: 10.3389/fmicb.2017.01123] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 06/01/2017] [Indexed: 11/13/2022] Open
Abstract
N-Acylhomoserine lactone (AHL)-acylase (also known as amidase or amidohydrolase) is a class of enzyme that belongs to the Ntn-hydrolase superfamily. As the name implies, AHL-acylases are capable of hydrolysing AHLs, the most studied signaling molecules for quorum sensing in Gram-negative bacteria. Enzymatic degradation of AHLs can be beneficial in attenuating bacterial virulence, which can be exploited as a novel approach to fight infection of human pathogens, phytopathogens or aquaculture-related contaminations. Numerous acylases from both prokaryotic and eukaryotic sources have been characterized and tested for the interference of quorum sensing-regulated functions. The existence of AHL-acylases in a multitude of organisms from various ecological niches, raises the question of what the physiological roles of AHL-acylases actually are. In this review, we attempt to bring together recent studies to extend our understanding of the biological functions of these enzymes in nature.
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Affiliation(s)
- Putri D Utari
- Chemical and Pharmaceutical Biology Department, University of GroningenGroningen, Netherlands
| | - Jan Vogel
- Chemical and Pharmaceutical Biology Department, University of GroningenGroningen, Netherlands
| | - Wim J Quax
- Chemical and Pharmaceutical Biology Department, University of GroningenGroningen, Netherlands
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222
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Zhang L, Narita Y, Gao L, Ali M, Oshiki M, Okabe S. Maximum specific growth rate of anammox bacteria revisited. WATER RESEARCH 2017; 116:296-303. [PMID: 28347953 DOI: 10.1016/j.watres.2017.03.027] [Citation(s) in RCA: 138] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 02/16/2017] [Accepted: 03/10/2017] [Indexed: 05/21/2023]
Abstract
Anammox bacteria have long been considered to be slow-growing bacteria. However, it has recently been reported that they could grow much faster than previously thought when they were cultivated in a membrane bioreactor (MBR) with a step-wise decrease in the solid retention time (SRT). Here, we reevaluated the maximum specific growth rates (μmax) of three phylogenetically distant anammox bacterial species (i.e. "Ca. Brocadia sinica", "Ca. Jettenia caeni" and "Ca. Scalindua sp.") by directly measuring 16S rRNA gene copy numbers using newly developed quantitative polymerase chain reaction (qPCR) assays. When free-living planktonic "Ca. B. sinica" and "Ca. J. caeni" cells were immobilized in polyvinyl alcohol (PVA) and sodium alginate (SA) gel beads and cultivated in an up-flow column reactor with high substrate loading rates at 37 °C, the μmax were determined to be 0.33 ± 0.02 d-1 and 0.18 d-1 (corresponding doubling time of 2.1 day and 3.9 day) from the exponential increases in 16S rRNA genes copy numbers, respectively. These values were faster than the fastest growth rates reported for these species so far. The cultivation of anammox bacteria in gel beads was achieved less than one month without special cultivation method and selection pressure, and the exponential increase in 16S rRNA gene numbers was directly measured by qPCR with high reproducibility; therefore, the resulting μmax values were considered accurate. Taken together, the fast growth is, therefore, considered to be an intrinsic kinetic property of anammox bacteria.
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Affiliation(s)
- Lei Zhang
- Division of Environmental Engineering, Faculty of Engineering, Hokkaido University, North 13, West 8, Sapporo, Hokkaido 060-8628, Japan
| | - Yuko Narita
- Division of Environmental Engineering, Faculty of Engineering, Hokkaido University, North 13, West 8, Sapporo, Hokkaido 060-8628, Japan
| | - Lin Gao
- Division of Environmental Engineering, Faculty of Engineering, Hokkaido University, North 13, West 8, Sapporo, Hokkaido 060-8628, Japan
| | - Muhammad Ali
- Division of Environmental Engineering, Faculty of Engineering, Hokkaido University, North 13, West 8, Sapporo, Hokkaido 060-8628, Japan; Water Desalination and Reuse Center (WDRC), Biological and Environmental Science and Engineering (BESE) Divison, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Mamoru Oshiki
- Department of Civil Engineering, Nagaoka National College of Technology, 888 Nishikatakaimachi, Nagaoka, Niigata 940-0834, Japan
| | - Satoshi Okabe
- Division of Environmental Engineering, Faculty of Engineering, Hokkaido University, North 13, West 8, Sapporo, Hokkaido 060-8628, Japan.
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223
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Szabó E, Liébana R, Hermansson M, Modin O, Persson F, Wilén BM. Microbial Population Dynamics and Ecosystem Functions of Anoxic/Aerobic Granular Sludge in Sequencing Batch Reactors Operated at Different Organic Loading Rates. Front Microbiol 2017; 8:770. [PMID: 28507540 PMCID: PMC5410608 DOI: 10.3389/fmicb.2017.00770] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 04/13/2017] [Indexed: 11/13/2022] Open
Abstract
The granular sludge process is an effective, low-footprint alternative to conventional activated sludge wastewater treatment. The architecture of the microbial granules allows the co-existence of different functional groups, e.g., nitrifying and denitrifying communities, which permits compact reactor design. However, little is known about the factors influencing community assembly in granular sludge, such as the effects of reactor operation strategies and influent wastewater composition. Here, we analyze the development of the microbiomes in parallel laboratory-scale anoxic/aerobic granular sludge reactors operated at low (0.9 kg m-3d-1), moderate (1.9 kg m-3d-1) and high (3.7 kg m-3d-1) organic loading rates (OLRs) and the same ammonium loading rate (0.2 kg NH4-N m-3d-1) for 84 days. Complete removal of organic carbon and ammonium was achieved in all three reactors after start-up, while the nitrogen removal (denitrification) efficiency increased with the OLR: 0% at low, 38% at moderate, and 66% at high loading rate. The bacterial communities at different loading rates diverged rapidly after start-up and showed less than 50% similarity after 6 days, and below 40% similarity after 84 days. The three reactor microbiomes were dominated by different genera (mainly Meganema, Thauera, Paracoccus, and Zoogloea), but these genera have similar ecosystem functions of EPS production, denitrification and polyhydroxyalkanoate (PHA) storage. Many less abundant but persistent taxa were also detected within these functional groups. The bacterial communities were functionally redundant irrespective of the loading rate applied. At steady-state reactor operation, the identity of the core community members was rather stable, but their relative abundances changed considerably over time. Furthermore, nitrifying bacteria were low in relative abundance and diversity in all reactors, despite their large contribution to nitrogen turnover. The results suggest that the OLR has considerable impact on the composition of the granular sludge communities, but also that the granule communities can be dynamic even at steady-state reactor operation due to high functional redundancy of several key guilds. Knowledge about microbial diversity with specific functional guilds under different operating conditions can be important for engineers to predict the stability of reactor functions during the start-up and continued reactor operation.
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Affiliation(s)
- Enikö Szabó
- Division of Water Environment Technology, Department of Civil and Environmental Engineering, Chalmers University of TechnologyGothenburg, Sweden
| | - Raquel Liébana
- Division of Water Environment Technology, Department of Civil and Environmental Engineering, Chalmers University of TechnologyGothenburg, Sweden
| | - Malte Hermansson
- Department of Chemistry and Molecular Biology, University of GothenburgGothenburg, Sweden
| | - Oskar Modin
- Division of Water Environment Technology, Department of Civil and Environmental Engineering, Chalmers University of TechnologyGothenburg, Sweden
| | - Frank Persson
- Division of Water Environment Technology, Department of Civil and Environmental Engineering, Chalmers University of TechnologyGothenburg, Sweden
| | - Britt-Marie Wilén
- Division of Water Environment Technology, Department of Civil and Environmental Engineering, Chalmers University of TechnologyGothenburg, Sweden
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224
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Guo Y, Liu S, Tang X, Yang F. Role of c-di-GMP in anammox aggregation and systematic analysis of its turnover protein in Candidatus Jettenia caeni. WATER RESEARCH 2017; 113:181-190. [PMID: 28214775 DOI: 10.1016/j.watres.2017.02.018] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Revised: 01/24/2017] [Accepted: 02/10/2017] [Indexed: 06/06/2023]
Abstract
The anaerobic ammonium oxidation (anammox) process has been recognized as a promising sewage treatment approach. Considering the susceptibility, it is meaningful to study the behaviors of anammox bacteria under the unfavorable conditions. Here, we found that anammox bacteria more probably tended to aggregation by the regulation of c-di-GMP against the unfavorable environmental stresses (low temperature, aerobic condition and low pH). Further using multiple protein sequence alignment, we systematically examined the functionality of thirteen genes encoding putative c-di-GMP metabolic enzymes in anammox organism Candidatus Jettenia caeni, revealing most of the predicted enzymes were predicted to be active. Particularly, ectopic expression of jcaA, a gene encoding a protein with both GGDEF domain and EAL domain, suggested that it encoded a functional enzyme capable of both synthesizing and degrading c-di-GMP, which was clearly confirmed by in vitro enzymatic assays and reverse transcription polymerase chain reaction (RT-PCR). Furthermore, the catalytic mechanism was simulated by the means of three-dimensional homology modeling and molecular docking. The identification of c-di-GMP turnover and its role in granulation for anammox organism provides a new perspective for regulation of its aggregation capability and further promotion of anammox performance in the application of wastewater treatment process.
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Affiliation(s)
- Yongzhao Guo
- Key Laboratory of Water and Sediment Sciences, Ministry of Education of China, Beijing, 100871, China; School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Sitong Liu
- Key Laboratory of Water and Sediment Sciences, Ministry of Education of China, Beijing, 100871, China; School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen, 518055, China.
| | - Xi Tang
- Key Laboratory of Water and Sediment Sciences, Ministry of Education of China, Beijing, 100871, China
| | - Fenglin Yang
- Key Laboratory of Industrial Ecology and Environmental Engineering, School of Environmental Science and Technology, Dalian University of Technology, Dalian, China
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225
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Oh HS, Tan CH, Low JH, Rzechowicz M, Siddiqui MF, Winters H, Kjelleberg S, Fane AG, Rice SA. Quorum quenching bacteria can be used to inhibit the biofouling of reverse osmosis membranes. WATER RESEARCH 2017; 112:29-37. [PMID: 28129553 DOI: 10.1016/j.watres.2017.01.028] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 01/16/2017] [Accepted: 01/17/2017] [Indexed: 06/06/2023]
Abstract
Over the last few decades, significant efforts have concentrated on mitigating biofouling in reverse osmosis (RO) systems, with a focus on non-toxic and sustainable strategies. Here, we explored the potential of applying quorum quenching (QQ) bacteria to control biofouling in a laboratory-scale RO system. For these experiments, Pantoea stewartii was used as a model biofilm forming organism because it was previously shown to be a relevant wastewater isolate that also forms biofilms in a quorum sensing (QS) dependent fashion. A recombinant Escherichia coli strain, which can produce a QQ enzyme, was first tested in batch biofilm assays and significantly reduced biofilm formation by P. stewartii. Subsequently, RO membranes were fouled with P. stewartii and the QQ bacterium was introduced into the RO system using two different strategies, direct injection and immobilization within a cartridge microfilter. When the QQ bacterial cells were directly injected into the system, N-acylhomoserine lactone signals were degraded, resulting in the reduction of biofouling. Similarly, the QQ bacteria controlled biofouling when immobilized within a microfilter placed downstream of the RO module to remove QS signals circulating in the system. These results demonstrate the proof-of-principle that QQ can be applied to control biofouling of RO membranes and may be applicable for use in full-scale plants.
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Affiliation(s)
- Hyun-Suk Oh
- Singapore Membrane Technology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore; Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore
| | - Chuan Hao Tan
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore; School of Materials Science & Engineering, Nanyang Technological University, Singapore
| | - Jiun Hui Low
- Singapore Membrane Technology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore; Interdisciplinary Graduate School, Nanyang Technological University, Singapore
| | - Miles Rzechowicz
- Singapore Membrane Technology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore
| | - Muhammad Faisal Siddiqui
- Singapore Membrane Technology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore
| | - Harvey Winters
- Singapore Membrane Technology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore; Fairleigh Dickinson University, 1000 River Road, Teaneck, NJ, USA
| | - Staffan Kjelleberg
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore; The School of Biological Sciences, Nanyang Technological University, Singapore; Centre for Marine Bio-Innovation, University of New South Wales, Sydney, Australia
| | - Anthony G Fane
- Singapore Membrane Technology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, Singapore.
| | - Scott A Rice
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore; The School of Biological Sciences, Nanyang Technological University, Singapore; Centre for Marine Bio-Innovation, University of New South Wales, Sydney, Australia.
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226
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Zhang C, Sun S, Liu X, Wan C, Lee DJ. Influence of operational conditions on the stability of aerobic granules from the perspective of quorum sensing. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:7640-7649. [PMID: 28124264 DOI: 10.1007/s11356-017-8417-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 01/05/2017] [Indexed: 06/06/2023]
Abstract
Integrated aerobic granules were first cultivated in two sequencing batch reactors (SBRs) (A1 and A2). Then, A1's influent organic loading rate (OLR) was changed from alternating to constant (cycling time was still 6 h), while A2's cycling time varied from 6 to 4 h (influent OLR strategy remained alternating). After 30-day operation since the manipulative alternations, granule breakage happened in two reactors at different operational stages, along with the decrease of granule intensity. Granule diameter in A1 declined from the original 0.84 to 0.32 cm during the whole operation, while granules in A2 dwindled to 0.31 cm on day 22 with similar size to A1. Both the amount of total extracellular polymeric substances (EPSs) and the protein were declining throughout the operation, and the large molecular weight of protein was considered closely related to the stability of aerobic granules. The relative AI-2 level decreased at the same time, and influent OLR strategy might had more evident impact on quorum sensing (QS) ability of sludge compared with starvation period. Combined with microbial results, the decline of total EPS amount in two reactors could be concluded as follows: During the reactor operation, some functional bacteria gradually lost their dominance and were eliminated from the reactors, which finally caused granule disintegration. In summary, the results further confirmed that alternating OLR and proper starvation period were two major factors in effective cultivation and stability of aerobic granules from the perspective of QS.
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Affiliation(s)
- Chen Zhang
- Shanghai Municipal Engineering Design General Institute, Shanghai, 200092, China
| | - Supu Sun
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China
| | - Xiang Liu
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China.
| | - Chunli Wan
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China.
| | - Duu-Jong Lee
- Department of Chemical Engineering, National Taiwan University, Taipei, 106, Taiwan
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227
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Influence of Nutrient Availability and Quorum Sensing on the Formation of Metabolically Inactive Microcolonies Within Structurally Heterogeneous Bacterial Biofilms: An Individual-Based 3D Cellular Automata Model. Bull Math Biol 2017; 79:594-618. [PMID: 28127665 DOI: 10.1007/s11538-017-0246-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 01/13/2017] [Indexed: 10/20/2022]
Abstract
The resistance of bacterial biofilms to antibiotic treatment has been attributed to the emergence of structurally heterogeneous microenvironments containing metabolically inactive cell populations. In this study, we use a three-dimensional individual-based cellular automata model to investigate the influence of nutrient availability and quorum sensing on microbial heterogeneity in growing biofilms. Mature biofilms exhibited at least three structurally distinct strata: a high-volume, homogeneous region sandwiched between two compact sections of high heterogeneity. Cell death occurred preferentially in layers in close proximity to the substratum, resulting in increased heterogeneity in this section of the biofilm; the thickness and heterogeneity of this lowermost layer increased with time, ultimately leading to sloughing. The model predicted the formation of metabolically dormant cellular microniches embedded within faster-growing cell clusters. Biofilms utilizing quorum sensing were more heterogeneous compared to their non-quorum sensing counterparts, and resisted sloughing, featuring a cell-devoid layer of EPS atop the substratum upon which the remainder of the biofilm developed. Overall, our study provides a computational framework to analyze metabolic diversity and heterogeneity of biofilm-associated microorganisms and may pave the way toward gaining further insights into the biophysical mechanisms of antibiotic resistance.
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228
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Tan CH, Lee KWK, Burmølle M, Kjelleberg S, Rice SA. All together now: experimental multispecies biofilm model systems. Environ Microbiol 2017; 19:42-53. [DOI: 10.1111/1462-2920.13594] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Chuan Hao Tan
- The Singapore Centre for Environmental Life Sciences EngineeringNanyang Technological University Singapore
| | - Kai Wei Kelvin Lee
- The Singapore Centre for Environmental Life Sciences EngineeringNanyang Technological University Singapore
| | - Mette Burmølle
- Section of Microbiology, Department of BiologyUniversity of CopenhagenCopenhagen Denmark
| | - Staffan Kjelleberg
- The Singapore Centre for Environmental Life Sciences EngineeringNanyang Technological University Singapore
- The School of Biological SciencesNanyang Technological University Singapore
| | - Scott A. Rice
- The Singapore Centre for Environmental Life Sciences EngineeringNanyang Technological University Singapore
- The School of Biological SciencesNanyang Technological University Singapore
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229
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Development of an extraction method and LC–MS analysis for N-acylated-l-homoserine lactones (AHLs) in wastewater treatment biofilms. J Chromatogr B Analyt Technol Biomed Life Sci 2017; 1041-1042:37-44. [DOI: 10.1016/j.jchromb.2016.11.029] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 11/17/2016] [Accepted: 11/20/2016] [Indexed: 11/17/2022]
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230
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Hu H, He J, Yu H, Liu J, Zhang J. A strategy to speed up formation and strengthen activity of biofilms at low temperature. RSC Adv 2017. [DOI: 10.1039/c7ra02223a] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The start-up period of biofilm reactors often takes a long time to obtain a mature and stable biofilm, especially at low temperature.
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Affiliation(s)
- Huizhi Hu
- School of Municipal and Environmental Engineering
- Harbin Institute of Technology
- Harbin
- China
| | - Junguo He
- School of Municipal and Environmental Engineering
- Harbin Institute of Technology
- Harbin
- China
| | - Huarong Yu
- School of Municipal and Environmental Engineering
- Harbin Institute of Technology
- Harbin
- China
| | - Jian Liu
- Central and Southern China Municipal Engineering Design and Research Institute Co., Ltd
- Wuhan
- China
| | - Jie Zhang
- School of Municipal and Environmental Engineering
- Harbin Institute of Technology
- Harbin
- China
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231
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Gsy, a novel glucansucrase from Leuconostoc mesenteroides, mediates the formation of cell aggregates in response to oxidative stress. Sci Rep 2016; 6:38122. [PMID: 27924943 PMCID: PMC5141493 DOI: 10.1038/srep38122] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 11/07/2016] [Indexed: 12/14/2022] Open
Abstract
Leuconostoc mesenteroides is a member of lactic acid bacteria (LAB) with wide applications in the food and medical industries. Species in the genus Leuconostoc are catalase-negative and generally regarded as facultative anaerobic or aerotolerant organisms. Despite their extensive use in industry, certain issues concerning the aerobic life of L. mesenteroides, e.g., the mechanism involved in the tolerance to oxygen, remain to be addressed. In this manuscript, a survival strategy employed by L. mesenteroides BD3749 in response to oxidative stress was elucidated. BD3749 cells cultivated in medium with sucrose available synthesized large amounts of exopolysaccharides, mostly consisting of insoluble EPS. When BD3749 cells were challenged with oxidative stress, the amount of insoluble EPS was greatly enhanced. The synthesized EPSs reduced the accumulation of reactive oxygen species (ROS) in bacterial cells and improved their survival during chronic oxidative stress. Another study showed that Gsy, a novel glucansucrase in the GH70 family that is induced by sucrose and up-regulated following exposure to oxygen, was responsible for the synthesis of insoluble EPS. Gsy was subsequently demonstrated to play pivotal roles in the formation of aggregates to alleviate the detrimental effects on BD3749 cells exerted by oxygen.
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232
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Ma ZP, Lao YM, Jin H, Lin GH, Cai ZH, Zhou J. Diverse Profiles of AI-1 Type Quorum Sensing Molecules in Cultivable Bacteria from the Mangrove ( Kandelia obovata) Rhizosphere Environment. Front Microbiol 2016; 7:1957. [PMID: 27994584 PMCID: PMC5136546 DOI: 10.3389/fmicb.2016.01957] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 11/22/2016] [Indexed: 11/25/2022] Open
Abstract
Mangrove rhizosphere environment harbors diverse populations of microbes, and some evidence showed that rhizobacteria behavior was regulated by quorum sensing (QS). Investigating the diverse profiles of QS molecules in mangrove ecosystems may shed light on the bacterial roles and lead to a better understanding of the symbiotic interactions between plants and microbes. The aims of the current study focus on identifying AI-1 type QS signals, i.e., acyl homoserine lactones (AHLs), in Kandelia obovata rhizosphere environment. Approximately 1200 rhizobacteria were screened and 184 strains (15.3%) tested were positive. Subsequent 16s rRNA gene sequencing and dereplication analyses identified 24 species from the positive isolates, which were affiliated to three different phyla, including Proteobacteria, Firmicutes, and Actinobacteria. Thin-layer chromatography separation of extracts revealed diverse AHL profiles and detected at least one active compound in the supernatant of these 24 cultivable AHL-producers. The active extracts from these bacterial isolates were further evaluated by ultra performance liquid chromatography-mass spectrometry, and the carbon side chain length ranged from C4 to C14. This is the first report on the diversity of AI-1 type auto-inducers in the mangrove plant K. obovata, and it is imperative to expand our knowledge of plant-bacteria interactions with respect to the maintenance of wetland ecosystem health.
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Affiliation(s)
- Zhi P Ma
- The Division of Ocean Science and Technology, Graduate School at Shenzhen, Tsinghua UniversityShenzhen, China; Shenzhen Public Platform for Screening and Application of Marine Microbial ResourcesShenzhen, China
| | - Yong M Lao
- The Division of Ocean Science and Technology, Graduate School at Shenzhen, Tsinghua UniversityShenzhen, China; Shenzhen Public Platform for Screening and Application of Marine Microbial ResourcesShenzhen, China
| | - Hui Jin
- The Division of Ocean Science and Technology, Graduate School at Shenzhen, Tsinghua UniversityShenzhen, China; Shenzhen Public Platform for Screening and Application of Marine Microbial ResourcesShenzhen, China
| | - Guang H Lin
- The Division of Ocean Science and Technology, Graduate School at Shenzhen, Tsinghua University Shenzhen, China
| | - Zhong H Cai
- The Division of Ocean Science and Technology, Graduate School at Shenzhen, Tsinghua UniversityShenzhen, China; Shenzhen Public Platform for Screening and Application of Marine Microbial ResourcesShenzhen, China
| | - Jin Zhou
- The Division of Ocean Science and Technology, Graduate School at Shenzhen, Tsinghua UniversityShenzhen, China; Shenzhen Public Platform for Screening and Application of Marine Microbial ResourcesShenzhen, China
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233
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Coughlan LM, Cotter PD, Hill C, Alvarez-Ordóñez A. New Weapons to Fight Old Enemies: Novel Strategies for the (Bio)control of Bacterial Biofilms in the Food Industry. Front Microbiol 2016; 7:1641. [PMID: 27803696 PMCID: PMC5067414 DOI: 10.3389/fmicb.2016.01641] [Citation(s) in RCA: 168] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 10/03/2016] [Indexed: 12/14/2022] Open
Abstract
Biofilms are microbial communities characterized by their adhesion to solid surfaces and the production of a matrix of exopolymeric substances, consisting of polysaccharides, proteins, DNA and lipids, which surround the microorganisms lending structural integrity and a unique biochemical profile to the biofilm. Biofilm formation enhances the ability of the producer/s to persist in a given environment. Pathogenic and spoilage bacterial species capable of forming biofilms are a significant problem for the healthcare and food industries, as their biofilm-forming ability protects them from common cleaning processes and allows them to remain in the environment post-sanitation. In the food industry, persistent bacteria colonize the inside of mixing tanks, vats and tubing, compromising food safety and quality. Strategies to overcome bacterial persistence through inhibition of biofilm formation or removal of mature biofilms are therefore necessary. Current biofilm control strategies employed in the food industry (cleaning and disinfection, material selection and surface preconditioning, plasma treatment, ultrasonication, etc.), although effective to a certain point, fall short of biofilm control. Efforts have been explored, mainly with a view to their application in pharmaceutical and healthcare settings, which focus on targeting molecular determinants regulating biofilm formation. Their application to the food industry would greatly aid efforts to eradicate undesirable bacteria from food processing environments and, ultimately, from food products. These approaches, in contrast to bactericidal approaches, exert less selective pressure which in turn would reduce the likelihood of resistance development. A particularly interesting strategy targets quorum sensing systems, which regulate gene expression in response to fluctuations in cell-population density governing essential cellular processes including biofilm formation. This review article discusses the problems associated with bacterial biofilms in the food industry and summarizes the recent strategies explored to inhibit biofilm formation, with special focus on those targeting quorum sensing.
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Affiliation(s)
- Laura M. Coughlan
- Teagasc Food Research CentreCork, Ireland
- School of Microbiology, University College CorkCork, Ireland
| | - Paul D. Cotter
- Teagasc Food Research CentreCork, Ireland
- APC Microbiome InstituteCork, Ireland
| | - Colin Hill
- School of Microbiology, University College CorkCork, Ireland
- APC Microbiome InstituteCork, Ireland
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234
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Liu S, Gunawan C, Barraud N, Rice SA, Harry EJ, Amal R. Understanding, Monitoring, and Controlling Biofilm Growth in Drinking Water Distribution Systems. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:8954-8976. [PMID: 27479445 DOI: 10.1021/acs.est.6b00835] [Citation(s) in RCA: 192] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In drinking water distribution systems (DWDS), biofilms are the predominant mode of microbial growth, with the presence of extracellular polymeric substance (EPS) protecting the biomass from environmental and shear stresses. Biofilm formation poses a significant problem to the drinking water industry as a potential source of bacterial contamination, including pathogens, and, in many cases, also affecting the taste and odor of drinking water and promoting the corrosion of pipes. This article critically reviews important research findings on biofilm growth in DWDS, examining the factors affecting their formation and characteristics as well as the various technologies to characterize and monitor and, ultimately, to control their growth. Research indicates that temperature fluctuations potentially affect not only the initial bacteria-to-surface attachment but also the growth rates of biofilms. For the latter, the effect is unique for each type of biofilm-forming bacteria; ammonia-oxidizing bacteria, for example, grow more-developed biofilms at a typical summer temperature of 22 °C compared to 12 °C in fall, and the opposite occurs for the pathogenic Vibrio cholerae. Recent investigations have found the formation of thinner yet denser biofilms under high and turbulent flow regimes of drinking water, in comparison to the more porous and loosely attached biofilms at low flow rates. Furthermore, in addition to the rather well-known tendency of significant biofilm growth on corrosion-prone metal pipes, research efforts also found leaching of growth-promoting organic compounds from the increasingly popular use of polymer-based pipes. Knowledge of the unique microbial members of drinking water biofilms and, importantly, the influence of water characteristics and operational conditions on their growth can be applied to optimize various operational parameters to minimize biofilm accumulation. More-detailed characterizations of the biofilm population size and structure are now feasible with fluorescence microscopy (epifluorescence and CLSM imaging with DNA, RNA, EPS, and protein and lipid stains) and electron microscopy imaging (ESEM). Importantly, thorough identification of microbial fingerprints in drinking water biofilms is achievable with DNA sequencing techniques (the 16S rRNA gene-based identification), which have revealed a prevalence of previously undetected bacterial members. Technologies are now moving toward in situ monitoring of biomass growth in distribution networks, including the development of optical fibers capable of differentiating biomass from chemical deposits. Taken together, management of biofilm growth in water distribution systems requires an integrated approach, starting from the treatment of water prior to entering the networks to the potential implementation of "biofilm-limiting" operational conditions and, finally, ending with the careful selection of available technologies for biofilm monitoring and control. For the latter, conventional practices, including chlorine-chloramine disinfection, flushing of DWDS, nutrient removal, and emerging technologies are discussed with their associated challenges.
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Affiliation(s)
| | - Cindy Gunawan
- ithree institute, University of Technology Sydney , Sydney, NSW 2007, Australia
| | - Nicolas Barraud
- Department of Microbiology, Genetics of Biofilms Unit, Institut Pasteur , Paris 75015, France
| | - Scott A Rice
- The Singapore Centre for Environmental Life Sciences Engineering and School of Biological Sciences, Nanyang Technological University , 639798, Singapore
| | - Elizabeth J Harry
- ithree institute, University of Technology Sydney , Sydney, NSW 2007, Australia
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235
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Identification of Quorum-Sensing Signal Molecules and a Biosynthetic Gene in Alicycliphilus sp. Isolated from Activated Sludge. SENSORS 2016; 16:s16081218. [PMID: 27490553 PMCID: PMC5017383 DOI: 10.3390/s16081218] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 07/19/2016] [Accepted: 07/29/2016] [Indexed: 01/09/2023]
Abstract
Activated sludge is a complicated mixture of various microorganisms that is used to treat sewage and industrial wastewater. Many bacteria produce N-acylhomoserine lactone (AHL) as a quorum-sensing signal molecule to regulate the expression of the exoenzymes used for wastewater treatment. Here, we isolated an AHL-producing bacteria from an activated sludge sample collected from an electronic component factory, which we named Alicycliphilus sp. B1. Clone library analysis revealed that Alicycliphilus was a subdominant genus in this sample. When we screened the activated sludge sample for AHL-producing strains, 12 of 14 the AHL-producing isolates were assigned to the genus Alicycliphilus. A putative AHL-synthase gene, ALISP_0667, was cloned from the genome of B1 and transformed into Escherichia coli DH5α. The AHLs were extracted from the culture supernatants of the B1 strain and E. coli DH5α cells harboring the ALISP_0667 gene and were identified by liquid chromatography-mass spectrometry as N-(3-hydroxydecanoyl)-l-homoserine lactone and N-(3-hydroxydodecanoyl)-l-homoserine lactone. The results of comparative genomic analysis suggested that the quorum-sensing genes in the B1 strain might have been acquired by horizontal gene transfer within activated sludge.
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236
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Huang J, Shi Y, Zeng G, Gu Y, Chen G, Shi L, Hu Y, Tang B, Zhou J. Acyl-homoserine lactone-based quorum sensing and quorum quenching hold promise to determine the performance of biological wastewater treatments: An overview. CHEMOSPHERE 2016; 157:137-151. [PMID: 27213243 DOI: 10.1016/j.chemosphere.2016.05.032] [Citation(s) in RCA: 146] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 04/21/2016] [Accepted: 05/11/2016] [Indexed: 06/05/2023]
Abstract
Quorum sensing (QS) is a communication process between cells, in which bacteria secrete and sense the specific chemicals, and regulate gene expression in response to population density. Quorum quenching (QQ) blocks QS system, and inhibits gene expression mediating bacterial behaviors. Given the extensive research of acyl-homoserine lactone (AHL) signals, existences and effects of AHL-based QS and QQ in biological wastewater treatments are being subject to high concern. This review summarizes AHL structure, synthesis mode, degradation mechanisms, analytical methods, environmental factors, AHL-based QS and QQ mechanisms. The existences and roles of AHL-based QS and QQ in biomembrane processes, activated sludge processes and membrane bioreactors are summarized and discussed, and corresponding exogenous regulation strategy by selective enhancement of AHL-based QS or QQ coexisting in biological wastewater treatments is suggested. Such strategies including the addition of AHL signals, AHL-producing bacteria as well as quorum quenching enzyme or bacteria can effectively improve wastewater treatment performance without killing or limiting bacterial survival and growth. This review will present the theoretical and practical cognition for bacterial AHL-based QS and QQ, suggest the feasibility of exogenous regulation strategies in biological wastewater treatments, and provide useful information to scientists and engineers who work in this field.
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Affiliation(s)
- Jinhui Huang
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan, 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, Hunan, 410082, China.
| | - Yahui Shi
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan, 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, Hunan, 410082, China
| | - Guangming Zeng
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan, 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, Hunan, 410082, China
| | - Yanling Gu
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan, 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, Hunan, 410082, China
| | - Guiqiu Chen
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan, 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, Hunan, 410082, China
| | - Lixiu Shi
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan, 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, Hunan, 410082, China
| | - Yi Hu
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan, 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, Hunan, 410082, China
| | - Bi Tang
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan, 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, Hunan, 410082, China
| | - Jianxin Zhou
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan, 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, Hunan, 410082, China
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237
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Yu H, Liang H, Qu F, He J, Xu G, Hu H, Li G. Biofouling control by biostimulation of quorum-quenching bacteria in a membrane bioreactor for wastewater treatment. Biotechnol Bioeng 2016; 113:2624-2632. [DOI: 10.1002/bit.26039] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Revised: 06/12/2016] [Accepted: 06/23/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Huarong Yu
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE); Harbin Institute of Technology; 73 Huanghe Road, Nangang District Harbin 150090 P.R. China
| | - Heng Liang
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE); Harbin Institute of Technology; 73 Huanghe Road, Nangang District Harbin 150090 P.R. China
| | - Fangshu Qu
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE); Harbin Institute of Technology; 73 Huanghe Road, Nangang District Harbin 150090 P.R. China
| | - Junguo He
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE); Harbin Institute of Technology; 73 Huanghe Road, Nangang District Harbin 150090 P.R. China
| | - Guoren Xu
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE); Harbin Institute of Technology; 73 Huanghe Road, Nangang District Harbin 150090 P.R. China
| | - Huizhi Hu
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE); Harbin Institute of Technology; 73 Huanghe Road, Nangang District Harbin 150090 P.R. China
| | - Guibai Li
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE); Harbin Institute of Technology; 73 Huanghe Road, Nangang District Harbin 150090 P.R. China
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238
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Hu H, He J, Liu J, Yu H, Zhang J. Biofilm activity and sludge characteristics affected by exogenous N-acyl homoserine lactones in biofilm reactors. BIORESOURCE TECHNOLOGY 2016; 211:339-47. [PMID: 27030953 DOI: 10.1016/j.biortech.2016.03.068] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 03/11/2016] [Accepted: 03/13/2016] [Indexed: 05/03/2023]
Abstract
This study verified the effect of N-acyl homoserine lactone (AHL) concentrations on mature biofilm systems. Three concentrations of an AHL mixture were used in the batch test. Introducing of 5nM AHLs significantly increased biofilm activity and increased sludge characteristics, which resulted in better pollutant removal performance, whereas exogenous 50nM and 500nM AHLs limited pollutant removal, especially COD and nitrogen removal. To further identify how exogenous signal molecular affects biofilm system nitrogen removal, analyzing of nitrifying bacteria through real-time polymerase chain reaction (RT-PCR) revealed that these additional signal molecules affect nitrifying to total bacteria ratio. In addition, the running state of the system was stable during 15days of operation without an AHL dose, which suggests that the changes in the system due to AHL are irreversible.
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Affiliation(s)
- Huizhi Hu
- School of Municipal and Environmental Engineering, Harbin Institute of Technology, 73 Huanghe Road, Harbin, China
| | - Junguo He
- School of Municipal and Environmental Engineering, Harbin Institute of Technology, 73 Huanghe Road, Harbin, China.
| | - Jian Liu
- Central and Southern China Municipal Engineering Design and Research Institute Co., Ltd., 41 Jiefang Park Road, Wuhan, China
| | - Huarong Yu
- School of Municipal and Environmental Engineering, Harbin Institute of Technology, 73 Huanghe Road, Harbin, China
| | - Jie Zhang
- School of Municipal and Environmental Engineering, Harbin Institute of Technology, 73 Huanghe Road, Harbin, China
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239
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Recent Advances in the Study of Marine Microbial Biofilm: From the Involvement of Quorum Sensing in Its Production up to Biotechnological Application of the Polysaccharide Fractions. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2016. [DOI: 10.3390/jmse4020034] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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240
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Yu H, Xu G, Qu F, Li G, Liang H. Effect of solid retention time on membrane fouling in membrane bioreactor: from the perspective of quorum sensing and quorum quenching. Appl Microbiol Biotechnol 2016; 100:7887-97. [PMID: 27087526 DOI: 10.1007/s00253-016-7496-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 03/20/2016] [Accepted: 03/22/2016] [Indexed: 10/21/2022]
Abstract
Solid retention time (SRT) is one of the most important operational parameters in membrane bioreactor (MBR), which significantly influences membrane fouling. It is widely recognized that SRT mainly changes biomass characteristics, and then, influences membrane fouling. Effect of SRT on quorum sensing (QS) in MBR, which could also influence fouling by coordinating biofilm formation, has not been reported. In this study, fouling, QS, soluble microbial products (SMP), and extracellular polymer substances (EPS) in MBRs operated under SRTs of 4, 10, and 40 days were investigated. The results showed that as SRT increased, the abundance of quorum quenching (QQ) bacteria increased, the quorum signal degradation activity of activated sludge increased, the concentrations of signal molecules in MBR decreased, the excretion of SMP and EPS decreased, and thus membrane biofouling was alleviated. Therefore, besides altering the biomass physiochemical properties, SRT also changed the balance between QS and QQ in MBR, and in this way, influenced membrane biofouling.
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Affiliation(s)
- Huarong Yu
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), Harbin Institute of Technology, 73 Huanghe Road, Nangang District, Harbin, 150090, People's Republic of China
| | - Guoren Xu
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), Harbin Institute of Technology, 73 Huanghe Road, Nangang District, Harbin, 150090, People's Republic of China.
| | - Fangshu Qu
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), Harbin Institute of Technology, 73 Huanghe Road, Nangang District, Harbin, 150090, People's Republic of China
| | - Guibai Li
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), Harbin Institute of Technology, 73 Huanghe Road, Nangang District, Harbin, 150090, People's Republic of China
| | - Heng Liang
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), Harbin Institute of Technology, 73 Huanghe Road, Nangang District, Harbin, 150090, People's Republic of China.
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241
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Yang J, Wu D, Li A, Guo H, Chen H, Pi S, Wei W, Ma F. The Addition of N-Hexanoyl-Homoserine Lactone to Improve the Microbial Flocculant Production of Agrobacterium tumefaciens Strain F2, an Exopolysaccharide Bioflocculant-Producing Bacterium. Appl Biochem Biotechnol 2016; 179:728-39. [DOI: 10.1007/s12010-016-2027-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2016] [Accepted: 02/19/2016] [Indexed: 11/25/2022]
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242
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Sharma A, Gupta P, Kumar R, Bhardwaj A. dPABBs: A Novel in silico Approach for Predicting and Designing Anti-biofilm Peptides. Sci Rep 2016; 6:21839. [PMID: 26912180 PMCID: PMC4766436 DOI: 10.1038/srep21839] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 01/27/2016] [Indexed: 12/22/2022] Open
Abstract
Increasingly, biofilms are being recognised for their causative role in persistent infections (like cystic fibrosis, otitis media, diabetic foot ulcers) and nosocomial diseases (biofilm-infected vascular catheters, implants and prosthetics). Given the clinical relevance of biofilms and their recalcitrance to conventional antibiotics, it is imperative that alternative therapeutics are proactively sought. We have developed dPABBs, a web server that facilitates the prediction and design of anti-biofilm peptides. The six SVM and Weka models implemented on dPABBs were observed to identify anti-biofilm peptides on the basis of their whole amino acid composition, selected residue features and the positional preference of the residues (maximum accuracy, sensitivity, specificity and MCC of 95.24%, 92.50%, 97.73% and 0.91, respectively, on the training datasets). On the N-terminus, it was seen that either of the cationic polar residues, R and K, is present at all five positions in case of the anti-biofilm peptides, whereas in the QS peptides, the uncharged polar residue S is preponderant at the first (also anionic polar residues D, E), third and fifth positions. Positive predictions were also obtained for 29 FDA-approved peptide drugs and ten antimicrobial peptides in clinical development, indicating at their possible repurposing for anti-biofilm therapy. dPABBs is freely accessible on: http://ab-openlab.csir.res.in/abp/antibiofilm/.
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Affiliation(s)
- Arun Sharma
- Open Source Drug Discovery (OSDD) Unit, Council of Scientific and Industrial Research (CSIR), New Delhi, India.,Academy of Scientific and Innovative Research (AcSIR), CSIR-OSDD Unit, CSIR-HQ, New Delhi, India
| | - Pooja Gupta
- Open Source Drug Discovery (OSDD) Unit, Council of Scientific and Industrial Research (CSIR), New Delhi, India.,Bhaskaracharya College of Applied Sciences, University of Delhi, New Delhi, India
| | - Rakesh Kumar
- Open Source Drug Discovery (OSDD) Unit, Council of Scientific and Industrial Research (CSIR), New Delhi, India.,Academy of Scientific and Innovative Research (AcSIR), CSIR-OSDD Unit, CSIR-HQ, New Delhi, India
| | - Anshu Bhardwaj
- Open Source Drug Discovery (OSDD) Unit, Council of Scientific and Industrial Research (CSIR), New Delhi, India.,Academy of Scientific and Innovative Research (AcSIR), CSIR-OSDD Unit, CSIR-HQ, New Delhi, India
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243
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Lee S, Park SK, Kwon H, Lee SH, Lee K, Nahm CH, Jo SJ, Oh HS, Park PK, Choo KH, Lee CH, Yi T. Crossing the Border between Laboratory and Field: Bacterial Quorum Quenching for Anti-Biofouling Strategy in an MBR. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:1788-95. [PMID: 26771993 DOI: 10.1021/acs.est.5b04795] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Quorum quenching (QQ) has recently been acknowledged to be a sustainable antifouling strategy and has been investigated widely using lab-scale membrane bioreactor (MBR) systems. This study attempted to bring this QQ-MBR closer to potential practical application. Two types of pilot-scale QQ-MBRs with QQ bacteria entrapping beads (QQ-beads) were installed and run at a wastewater treatment plant, feeding real municipal wastewater to test the systems' effectiveness for membrane fouling control and thus the amount of energy savings, even under harsh environmental conditions. The rate of transmembrane pressure (TMP) build-up was significantly mitigated in QQ-MBR compared to that in a conventional-MBR. Consequently, QQ-MBR can substantially reduce energy consumption by reducing coarse bubble aeration without compromising the effluent water quality. The addition of QQ-beads to a conventional MBR substantially affected the EPS concentrations, as well as microbial floc size in the mixed liquor. Furthermore, the QQ activity and mechanical stability of QQ-beads were well maintained for at least four months, indicating QQ-MBR has good potential for practical applications.
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Affiliation(s)
- Seonki Lee
- School of Chemical and Biological Engineering, Seoul National University , Seoul 08826, Republic of Korea
| | - Seung-Kook Park
- Hanwha Engineering and Construction , 76, Gajeong-Ro, Yuseong-Gu, Daejeon 305-804, Republic of Korea
| | - Hyeokpil Kwon
- School of Chemical and Biological Engineering, Seoul National University , Seoul 08826, Republic of Korea
| | - Sang Hyun Lee
- School of Chemical and Biological Engineering, Seoul National University , Seoul 08826, Republic of Korea
| | - Kibaek Lee
- School of Chemical and Biological Engineering, Seoul National University , Seoul 08826, Republic of Korea
| | - Chang Hyun Nahm
- School of Chemical and Biological Engineering, Seoul National University , Seoul 08826, Republic of Korea
| | - Sung Jun Jo
- School of Chemical and Biological Engineering, Seoul National University , Seoul 08826, Republic of Korea
| | - Hyun-Suk Oh
- School of Chemical and Biological Engineering, Seoul National University , Seoul 08826, Republic of Korea
| | - Pyung-Kyu Park
- Department of Environmental Engineering, Yonsei University , Wonju, 220-710, Republic of Korea
| | - Kwang-Ho Choo
- Department of Environmental Engineering, Kyungpook National University , Daegu, 702-701, Republic of Korea
| | - Chung-Hak Lee
- School of Chemical and Biological Engineering, Seoul National University , Seoul 08826, Republic of Korea
| | - Taewoo Yi
- Hanwha Engineering and Construction , 76, Gajeong-Ro, Yuseong-Gu, Daejeon 305-804, Republic of Korea
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244
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Zhang W, Li C. Exploiting Quorum Sensing Interfering Strategies in Gram-Negative Bacteria for the Enhancement of Environmental Applications. Front Microbiol 2016; 6:1535. [PMID: 26779175 PMCID: PMC4705238 DOI: 10.3389/fmicb.2015.01535] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 12/21/2015] [Indexed: 12/12/2022] Open
Abstract
Quorum sensing (QS) is a widespread intercellular form of communication to coordinate physiological processes and cooperative activities of bacteria at the population level, and it depends on the production, secretion, and detection of small diffusible autoinducers, such as acyl-homoserine lactones (AHLs), auto-inducing oligo-peptides (AIPs) and autoinducer 2. In this review, the function of QS autoinducers of gram-negative bacteria in different aspects of wastewater treatment systems is examined. Based on research primarily performed over the past 10 years, QS involvement in the formation of biofilm and aerobic granules and changes of the microbial community and degradation/transformation pathways is discussed. In particular, the QS pathway in the role of bacterial infections and disease prevention in aquaculture is addressed. Interference of QS autoinducer-regulated pathways is considered potential treatment for a variety of environmentally related problems. This review is expected to serve as a stepping stone for further study and development strategies based on the mediation of QS-regulated pathways to enhance applications in both wastewater treatment systems and aquaculture.
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Affiliation(s)
- Weiwei Zhang
- Department of Aquaculture, School of Marine Sciences, Ningbo University Ningbo, China
| | - Chenghua Li
- Department of Aquaculture, School of Marine Sciences, Ningbo University Ningbo, China
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245
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Hu H, He J, Liu J, Yu H, Tang J, Zhang J. Role of N-acyl-homoserine lactone (AHL) based quorum sensing on biofilm formation on packing media in wastewater treatment process. RSC Adv 2016. [DOI: 10.1039/c5ra23466b] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Quorum sensing (QS) signaling has been extensively studied in granules and single species populations.
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Affiliation(s)
- Huizhi Hu
- School of Municipal and Environmental Engineering
- Harbin Institute of Technology
- Harbin
- China
| | - Junguo He
- School of Municipal and Environmental Engineering
- Harbin Institute of Technology
- Harbin
- China
| | - Jian Liu
- School of Municipal and Environmental Engineering
- Harbin Institute of Technology
- Harbin
- China
| | - Huarong Yu
- School of Municipal and Environmental Engineering
- Harbin Institute of Technology
- Harbin
- China
| | - Jian Tang
- School of Municipal and Environmental Engineering
- Harbin Institute of Technology
- Harbin
- China
| | - Jie Zhang
- School of Municipal and Environmental Engineering
- Harbin Institute of Technology
- Harbin
- China
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246
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Understanding of aerobic granulation enhanced by starvation in the perspective of quorum sensing. Appl Microbiol Biotechnol 2015; 100:3747-55. [DOI: 10.1007/s00253-015-7246-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2015] [Revised: 12/08/2015] [Accepted: 12/09/2015] [Indexed: 12/22/2022]
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247
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Yong YC, Wu XY, Sun JZ, Cao YX, Song H. Engineering quorum sensing signaling of Pseudomonas for enhanced wastewater treatment and electricity harvest: A review. CHEMOSPHERE 2015; 140:18-25. [PMID: 25455678 DOI: 10.1016/j.chemosphere.2014.10.020] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2014] [Revised: 07/13/2014] [Accepted: 10/05/2014] [Indexed: 06/04/2023]
Abstract
Cell-cell communication that enables synchronized population behaviors in microbial communities dictates various biological processes. It is of great interest to unveil the underlying mechanisms of fine-tuning cell-cell communication to achieve environmental and energy applications. Pseudomonas is a ubiquitous microbe in environments that had wide applications in bioremediation and bioenergy generation. The quorum sensing (QS, a generic cell-cell communication mechanism) systems of Pseudomonas underlie the aromatics biodegradation, denitrification and electricity harvest. Here, we reviewed the recent progresses of the genetic strategies in engineering QS circuits to improve efficiency of wastewater treatment and the performance of microbial fuel cells.
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Affiliation(s)
- Yang-Chun Yong
- Biofuels Institute, School of the Environment, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, Jiangsu Province, China.
| | - Xiang-Yang Wu
- Biofuels Institute, School of the Environment, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, Jiangsu Province, China
| | - Jian-Zhong Sun
- Biofuels Institute, School of the Environment, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, Jiangsu Province, China
| | - Ying-Xiu Cao
- Key Laboratory of Systems Bioengineering (Ministry of Education), SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; School of Chemical & Biomedical Engineering, and Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore 637457, Singapore
| | - Hao Song
- Key Laboratory of Systems Bioengineering (Ministry of Education), SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; School of Chemical & Biomedical Engineering, and Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore 637457, Singapore.
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248
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Ding Y, Feng H, Huang W, Li N, Zhou Y, Wang M, Zhang X, Shen D. The effect of quorum sensing on anaerobic granular sludge in different pH conditions. Biochem Eng J 2015. [DOI: 10.1016/j.bej.2015.08.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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249
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Ding Y, Feng H, Huang W, Shen D, Wang M. A sustainable method for effective regulation of anaerobic granular sludge: artificially increasing the concentration of signal molecules by cultivating a secreting strain. BIORESOURCE TECHNOLOGY 2015; 196:273-278. [PMID: 26253911 DOI: 10.1016/j.biortech.2015.07.066] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 07/17/2015] [Accepted: 07/20/2015] [Indexed: 06/04/2023]
Abstract
This study introduces sustainable quorum sensing (QS) granulation for anaerobic granular sludge (AnGS) and investigates the efficiency of three types of signal molecules on regulating AnGS granulation. The signal molecules of a secreting strain cultured in a QS regulating reactor increased their concentrations in an expanded granular sludge bed reactor throughout the granulating process. Increasing content of autoinducer-2 (AI-2) strengthened interspecific QS communication and gave a best performance with larger granular diameters, higher extracellular polymeric substance (EPS) production and relative hydrophobicity (RH). N-butyryl-homoserine lactone (C4-HSL) QS regulation was also favorable for granular growth, but its regulation was less than that of AI-2-QS. The AnGS granulated under these two types of QS regulations guided more filamentous bacteria to take part in granulation. Under diffusible signal factor (DSF)-QS regulation, the sludge had a lower granular level with a smaller granule diameter, lower EPS production (RH) when compared that of control medium.
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Affiliation(s)
- Yangcheng Ding
- Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Zhejiang Gongshang University, Hangzhou 310012, China
| | - Huajun Feng
- Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Zhejiang Gongshang University, Hangzhou 310012, China.
| | - Wenkun Huang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Dongsheng Shen
- Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Zhejiang Gongshang University, Hangzhou 310012, China
| | - Meizhen Wang
- Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Zhejiang Gongshang University, Hangzhou 310012, China
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250
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Abstract
A wide variety of organisms communicate via the chemical channel using small molecules. A structural feature quite often found is the lactone motif. In the present paper, the current knowledge on such lactones will be described, concentrating on the structure, chemistry, function, biosynthesis and synthesis of these compounds. Lactone semiochemicals from insects, vertebrates and bacteria, which this article will focus on, are particularly well investigated. In addition, some ideas on the advantageous use of lactones as volatile signals, which promoted their evolutionary development, will be discussed.
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Affiliation(s)
- Stefan Schulz
- Institute of Organic Chemistry, Technische Universität Braunschweig, 38106 Braunschweig, Germany.
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