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Noethen M, Becher J, Menberg K, Blum P, Schüppler S, Metzler E, Rasch G, Griebler C, Bayer P. Environmental impact of an anthropogenic groundwater temperature hotspot. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 955:177153. [PMID: 39442724 DOI: 10.1016/j.scitotenv.2024.177153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2024] [Revised: 10/04/2024] [Accepted: 10/20/2024] [Indexed: 10/25/2024]
Abstract
Heat emitted by buildings and other infrastructure accumulates in the subsurface. This additional heat can cause a pronounced shift in thermal boundary conditions of the important groundwater ecosystem. Shallow groundwater systems in Central Europe are often inhabited by communities of fauna adapted to cold and stable conditions as well as microorganisms, whose activity is dependent on ambient temperatures. At a local groundwater temperature hotspot of up to 23 °C, caused by a water park, we assessed the environmental impact of this thermal alteration on the shallow groundwater system. The results show that the overall groundwater quality at the site is influenced by anthropogenic land use, compared to wells in a nearby water protection zone. However, neither hydrochemical nor ecological characteristics of groundwater from wells in the vicinity of the water park indicate any significant dependence on temperature. Hence, we conclude that in this eutrophic and anoxic aquifer moderate heat stress does not lead to significant alterations in terms of hydrochemistry as well as microbiological properties. Due to the overall low oxygen concentrations (<1 mg/l), stygofauna is present only occasionally and cannot be used as bioindicators. These results have to be verified for other aquifer types and would benefit from a more in-depth analysis of microbial community composition.
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Affiliation(s)
- Maximilian Noethen
- Department of Applied Geology, Institute of Geosciences and Geography, Martin Luther University Halle-Wittenberg (MLU), Germany.
| | - Julia Becher
- Department of Applied Geology, Institute of Geosciences and Geography, Martin Luther University Halle-Wittenberg (MLU), Germany
| | - Kathrin Menberg
- Institute of Applied Geosciences (AGW), Karlsruhe Institute of Technology (KIT), Germany
| | - Philipp Blum
- Institute of Applied Geosciences (AGW), Karlsruhe Institute of Technology (KIT), Germany
| | - Simon Schüppler
- European Institute for Energy Research (EIFER), Karlsruhe, Germany
| | | | - Grit Rasch
- University of Vienna, Department of Functional and Evolutionary Ecology, Vienna, Austria
| | - Christian Griebler
- University of Vienna, Department of Functional and Evolutionary Ecology, Vienna, Austria
| | - Peter Bayer
- Department of Applied Geology, Institute of Geosciences and Geography, Martin Luther University Halle-Wittenberg (MLU), Germany
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2
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Hong JK, Kim SB, Wee GN, Kang BR, No JH, Nishu SD, Park J, Lee TK. Assessing long-term ecological impacts of PCE contamination in groundwater using a flow cytometric fingerprint approach. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 931:172698. [PMID: 38688365 DOI: 10.1016/j.scitotenv.2024.172698] [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: 12/12/2023] [Revised: 04/09/2024] [Accepted: 04/21/2024] [Indexed: 05/02/2024]
Abstract
This study aims to develop and validate a comprehensive method for assessing ecological disturbances in groundwater ecosystems caused by tetrachloroethylene (PCE) contamination, utilizing flow cytometry (FCM) fingerprint approach. We hypothesized that the ecological disturbance resulting from PCE contamination would exhibit 'press disturbance', persisting over extended periods, and inducing notable phenotypic differences in the microbial community compared to undisturbed groundwater. We collected 40 groundwater samples from industrial district with a history of over twenty years of PCE contamination, along with 56 control groundwater from the national surveillance groundwater system. FCM revealed significant alterations in the phenotypic diversity of microbial communities in PCE-contaminated groundwater, particularly during the dry season. The presence of specific dechlorinating bacteria (Dehalococcoides, Dehalogenimonas, and Geobacter) and their syntrophic partners was identified as an indicator of contamination. Phenotypic diversity measures provided clearer and more direct reflections of contamination impact compared to taxonomic diversity measures. This study establishes FCM fingerprinting as a simple, robust, and accurate method for evaluating ecological disturbances, with potential applications in early warning systems and continuous monitoring of groundwater contamination. The findings not only underscore the sensitivity of FCM in detecting phenotypic variations induced by environmental stressors but also highlight its utility in understanding the complex dynamics of microbial communities in contaminated groundwater ecosystems.
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Affiliation(s)
- Jin-Kyung Hong
- Department of Environmental and Energy Engineering, Yonsei University, Wonju 26493, Republic of Korea
| | - Soo Bin Kim
- Department of Environmental and Energy Engineering, Yonsei University, Wonju 26493, Republic of Korea
| | - Gui Nam Wee
- Department of Environmental and Energy Engineering, Yonsei University, Wonju 26493, Republic of Korea
| | - Bo Ram Kang
- Department of Environmental and Energy Engineering, Yonsei University, Wonju 26493, Republic of Korea
| | - Jee Hyun No
- Department of Environmental and Energy Engineering, Yonsei University, Wonju 26493, Republic of Korea
| | - Susmita Das Nishu
- Department of Environmental and Energy Engineering, Yonsei University, Wonju 26493, Republic of Korea
| | - Joonhong Park
- Department of Civil and Environmental Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Tae Kwon Lee
- Department of Environmental and Energy Engineering, Yonsei University, Wonju 26493, Republic of Korea.
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3
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Wang J, Huo L, Bian K, He H, Dodd MC, Pinto AJ, Huang CH. Efficacy and Mechanism of Antibiotic Resistance Gene Degradation and Cell Membrane Damage during Ultraviolet Advanced Oxidation Processes. ACS ES&T WATER 2024; 4:2746-2755. [PMID: 38903200 PMCID: PMC11186015 DOI: 10.1021/acsestwater.4c00350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Revised: 05/21/2024] [Accepted: 05/23/2024] [Indexed: 06/22/2024]
Abstract
Combinations of UV with oxidants can initiate advanced oxidation processes (AOPs) and enhance bacterial inactivation. However, the effectiveness and mechanisms of UV-AOPs in damaging nucleic acids (e.g., antibiotic resistance genes (ARGs)) and cell integrity represent a knowledge gap. This study comprehensively compared ARG degradation and cell membrane damage under three different UV-AOPs. The extracellular ARG (eARG) removal efficiency followed the order of UV/chlorine > UV/H2O2 > UV/peracetic acid (PAA). Hydroxyl radical (•OH) and reactive chlorine species (RCS) largely contributed to eARG removal, while organic radicals made a minor contribution. For intracellular ARGs (iARGs), UV/H2O2 did not remove better than UV alone due to the scavenging of •OH by cell components, whereas UV/PAA provided a modest synergism, likely due to diffusion of PAA into cells and intracellular •OH generation. Comparatively, UV/chlorine achieved significant synergistic iARG removal, suggesting the critical role of the RCS in resisting cellular scavenging and inactivating ARGs. Additionally, flow cytometry analysis demonstrated that membrane damage was mainly attributed to chlorine oxidation, while the impacts of radicals, H2O2, and PAA were negligible. These results provide mechanistic insights into bacterial inactivation and fate of ARGs during UV-AOPs, and shed light on the suitability of quantitative polymerase chain reaction (qPCR) and flow cytometry in assessing disinfection performance.
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Affiliation(s)
- Junyue Wang
- School
of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Linxuan Huo
- School
of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Kaiqin Bian
- School
of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Huan He
- State
Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory
of Yangtze Water Environment, Ministry of Education, College of Environmental
Science and Engineering, Tongji University, Shanghai 200092, P. R. China
| | - Michael C. Dodd
- Department
of Civil and Environmental Engineering, University of Washington (UW), Seattle, Washington 98195-2700, United States
| | - Ameet J. Pinto
- School
of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Ching-Hua Huang
- School
of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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Chen PWY, Olivia M, Gong GC, Jan S, Tsai AY. Viral Dynamics in the Tropical Pacific Ocean: A Comparison between Within and Outside a Warm Eddy. Viruses 2024; 16:937. [PMID: 38932229 PMCID: PMC11209615 DOI: 10.3390/v16060937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2024] [Revised: 06/02/2024] [Accepted: 06/06/2024] [Indexed: 06/28/2024] Open
Abstract
In mesoscale eddies, the chemical properties and biological composition are different from those in the surrounding water due to their unique physical processes. The mechanism of physical-biological coupling in warm-core eddies is unclear, especially because no studies have examined the effects of environmental factors on bacteria and viruses. The purpose of the present study was to examine the influence of an anticyclonic warm eddy on the relationship between bacterial and viral abundances, as well as viral activity (viral production), at different depths. At the core of the warm eddy, the bacterial abundance (0.48 to 2.82 × 105 cells mL-1) fluctuated less than that outside the eddy (1.12 to 7.03 × 105 cells mL-1). In particular, there was a four-fold higher viral-bacterial abundance ratio (VBR) estimated within the eddy, below the layer of the deep chlorophyll maximum, than outside the eddy. An anticyclonic warm eddy with downwelling at its center may contribute to viruses being transmitted directly into the deep ocean through adsorption on particulate organic matter while sinking. Overall, our findings provide valuable insights into the interaction between bacterial and viral abundances and their ecological mechanisms within a warm eddy.
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Affiliation(s)
- Patrichka Wei-Yi Chen
- Institute of Marine Environment and Ecology, National Taiwan Ocean University, Keelung 202-24, Taiwan; (P.W.-Y.C.); (M.O.); (G.-C.G.)
- Doctoral Degree Program in Ocean Resource and Environmental Changes, National Taiwan Ocean University, Keelung 202-24, Taiwan
| | - Madeline Olivia
- Institute of Marine Environment and Ecology, National Taiwan Ocean University, Keelung 202-24, Taiwan; (P.W.-Y.C.); (M.O.); (G.-C.G.)
- Doctoral Degree Program in Ocean Resource and Environmental Changes, National Taiwan Ocean University, Keelung 202-24, Taiwan
| | - Gwo-Ching Gong
- Institute of Marine Environment and Ecology, National Taiwan Ocean University, Keelung 202-24, Taiwan; (P.W.-Y.C.); (M.O.); (G.-C.G.)
- Doctoral Degree Program in Ocean Resource and Environmental Changes, National Taiwan Ocean University, Keelung 202-24, Taiwan
- Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 202-24, Taiwan
| | - Sen Jan
- Institute of Oceanography, National Taiwan University, Taipei 106319, Taiwan;
| | - An-Yi Tsai
- Institute of Marine Environment and Ecology, National Taiwan Ocean University, Keelung 202-24, Taiwan; (P.W.-Y.C.); (M.O.); (G.-C.G.)
- Doctoral Degree Program in Ocean Resource and Environmental Changes, National Taiwan Ocean University, Keelung 202-24, Taiwan
- Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 202-24, Taiwan
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Jenkins JA, Draugelis-Dale RO, Hoffpauir NM, Baudoin BA, Matkin C, Driver L, Hodges S, Brown BL. Flow cytometric assessments of metabolic activity in bacterial assemblages provide insight into ecosystem condition along the Buffalo National River, Arkansas. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 921:170462. [PMID: 38311076 DOI: 10.1016/j.scitotenv.2024.170462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 01/22/2024] [Accepted: 01/24/2024] [Indexed: 02/06/2024]
Abstract
The Buffalo National River (BNR), on karst terrain in Arkansas, is considered an extraordinary water resource. Water collected in Spring 2017 along BNR was metagenomically analyzed using 16S rDNA, and for 17 months (5/2017-11/2018), bacterial responses were measured in relation to nutrients sampled along a stretch of BNR near a concentrated animal feed operation (CAFO) on Big Creek. Because cell count and esterase activity can increase proportionally with organic enrichment, they were hypothesized to be elevated near the CAFO. Counts (colony forming units; CFUs) were different among sites for 73 % of the months; Big Creek generated highest CFUs 27 % of the time, with the closest downstream site at 13.3 %. Esterase activity was different among sites 94 % of the time, with Big Creek exhibiting lowest activity 71 % of the time. Over the months, activity was similar across sites at ~70 % active, except at Big Creek (56 %). The α-diversity of BNR microbial consortia near a wastewater treatment plant (WWTP) and the CAFO was related to distance from the WWTP and CAFO. The inverse relationship between high CFUs and low esterase activity at Big Creek (r = -0.71) actuated in vitro exposures of bacteria to organic wastewater contaminants (OWC) previously identified in the watershed. Exponential-phase Escherichia coli (stock strain), Streptococcus suis (avirulent, from swine), and S. dysgalactiae (virulent, from silver carp, Hypophthalmichthys molitrix) were incubated with atrazine, pharmaceuticals (17 α-ethynylestradiol and trenbolone), and antimicrobials (tylosin and butylparaben). Bacteria were differentially responsive. Activity varied with exposure time and OWC type, but not concentration; atrazine decreased it most. Taken together - the metagenomic taxonomic similarities along BNR, slightly higher bacterial growth and lower bacterial esterase at the CAFO, and the lab exposures of bacterial strains showing that OWC altered metabolism - the results indicated that bioactive OWC entering the watershed can strongly influence microbial processes in the aquatic ecosystem.
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Affiliation(s)
- Jill A Jenkins
- U.S. Geological Survey, Wetland and Aquatic Research Center, 700 Cajundome Blvd., Lafayette, LA 70506, USA.
| | - Rassa O Draugelis-Dale
- U.S. Geological Survey, Wetland and Aquatic Research Center, 700 Cajundome Blvd., Lafayette, LA 70506, USA
| | - Nina M Hoffpauir
- U.S. Geological Survey, Wetland and Aquatic Research Center, 700 Cajundome Blvd., Lafayette, LA 70506, USA
| | - Brooke A Baudoin
- U.S. Geological Survey, Wetland and Aquatic Research Center, 700 Cajundome Blvd., Lafayette, LA 70506, USA
| | - Caroline Matkin
- U.S. Geological Survey, Wetland and Aquatic Research Center, 700 Cajundome Blvd., Lafayette, LA 70506, USA.
| | - Lucas Driver
- U.S. Geological Survey, Lower Mississippi-Gulf Water Science Center, 401 Hardin Rd., Little Rock, AR 72211, USA.
| | - Shawn Hodges
- Buffalo National River, National Park Service, 402 N. Walnut St., Harrison, AR 72601, USA.
| | - Bonnie L Brown
- Department of Biological Sciences, University of New Hampshire, 105 Main St., Durham, NH 03824, USA.
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Egli T, Campostrini L, Leifels M, Füchslin HP, Kolm C, Dan C, Zimmermann S, Hauss V, Guiller A, Grasso L, Shajkofci A, Farnleitner AH, Kirschner AKT. Domestic hot-water boilers harbour active thermophilic bacterial communities distinctly different from those in the cold-water supply. WATER RESEARCH 2024; 253:121109. [PMID: 38377920 DOI: 10.1016/j.watres.2024.121109] [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: 10/28/2023] [Revised: 12/29/2023] [Accepted: 01/04/2024] [Indexed: 02/22/2024]
Abstract
Running cold and hot water in buildings is a widely established commodity. However, interests regarding hygiene and microbiological aspects had so far been focussed on cold water. Little attention has been given to the microbiology of domestic hot-water installations (DHWIs), except for aspects of pathogenic Legionella. World-wide, regulations consider hot (or warm) water as 'heated drinking water' that must comply (cold) drinking water (DW) standards. However, the few reports that exist indicate presence and growth of microbial flora in DHWIs, even when supplied with water with disinfectant residual. Using flow cytometric (FCM) total cell counting (TCC), FCM-fingerprinting, and 16S rRNA-gene-based metagenomic analysis, the characteristics and composition of bacterial communities in cold drinking water (DW) and hot water from associated boilers (operating at 50 - 60 °C) was studied in 14 selected inhouse DW installations located in Switzerland and Austria. A sampling strategy was applied that ensured access to the bulk water phase of both, supplied cold DW and produced hot boiler water. Generally, 1.3- to 8-fold enhanced TCCs were recorded in hot water compared to those in the supplied cold DW. FCM-fingerprints of cold and corresponding hot water from individual buildings indicated different composition of cold- and hot-water microbial floras. Also, hot waters from each of the boilers sampled had its own individual FCM-fingerprint. 16S rRNA-gene-based metagenomic analysis confirmed the marked differences in composition of microbiomes. E.g., in three neighbouring houses supplied from the same public network pipe each hot-water boiler contained its own thermophilic bacterial flora. Generally, bacterial diversity in cold DW was broad, that in hot water was restricted, with mostly thermophilic strains from the families Hydrogenophilaceae, Nitrosomonadaceae and Thermaceae dominating. Batch growth assays, consisting of cold DW heated up to 50 - 60 °C and inoculated with hot water, resulted in immediate cell growth with doubling times between 5 and 10 h. When cold DW was used as an inoculum no significant growth was observed. Even boilers supplied with UVC-treated cold DW contained an actively growing microbial flora, suggesting such hot-water systems as autonomously operating, thermophilic bioreactors. The generation of assimilable organic carbon from dissolved organic carbon due to heating appears to be the driver for growth of thermophilic microbial communities. Our report suggests that a man-made microbial ecosystem, very close to us all and of potential hygienic importance, may have been overlooked so far. Despite consumers having been exposed to microbial hot-water flora for a long time, with no major pathogens so far been associated specifically with hot-water usage (except for Legionella), the role of harmless thermophiles and their interaction with potential human pathogens able to grow at elevated temperatures in DHWIs remains to be investigated.
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Affiliation(s)
- Thomas Egli
- Microbes-in-Water GmbH, Feldmeilen CH-8706, Switzerland.
| | - Lena Campostrini
- Institute for Hygiene and Applied Immunology, Water Microbiology, Medical University of Vienna, Vienna A-1090, Austria; Interuniversity Cooperation Centre Water & Health, Austria
| | - Mats Leifels
- Division of Water Quality and Health, Dept. Pharmacology, Physiology and Microbiology, Karl Landsteiner University, Krems A-3500, Austria; Interuniversity Cooperation Centre Water & Health, Austria
| | | | - Claudia Kolm
- Division of Water Quality and Health, Dept. Pharmacology, Physiology and Microbiology, Karl Landsteiner University, Krems A-3500, Austria; Centre for Water Resource Systems, Vienna University of Technology, Vienna A-1040, Austria; Interuniversity Cooperation Centre Water & Health, Austria
| | - Cheng Dan
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | | | - Vivian Hauss
- bNovate Technologies SA, Zurich CH-8045, Switzerland
| | | | | | | | - Andreas H Farnleitner
- Division of Water Quality and Health, Dept. Pharmacology, Physiology and Microbiology, Karl Landsteiner University, Krems A-3500, Austria; Centre for Water Resource Systems, Vienna University of Technology, Vienna A-1040, Austria; Interuniversity Cooperation Centre Water & Health, Austria
| | - Alexander K T Kirschner
- Institute for Hygiene and Applied Immunology, Water Microbiology, Medical University of Vienna, Vienna A-1090, Austria; Division of Water Quality and Health, Dept. Pharmacology, Physiology and Microbiology, Karl Landsteiner University, Krems A-3500, Austria; Interuniversity Cooperation Centre Water & Health, Austria.
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7
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Campostrini L, Proksch P, Jakwerth S, Farnleitner AH, Kirschner AKT. Introducing bacterial community turnover times to elucidate temporal and spatial hotspots of biological instability in a large Austrian drinking water distribution network. WATER RESEARCH 2024; 252:121188. [PMID: 38324987 DOI: 10.1016/j.watres.2024.121188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 01/16/2024] [Accepted: 01/23/2024] [Indexed: 02/09/2024]
Abstract
Ensuring biological stability in drinking water distribution systems (DWDSs) is important to reduce the risk of aesthetic, operational and hygienic impairments of the distributed water. Drinking water after treatment often changes in quality during transport due to interactions with pipe-associated biofilms, temperature increases and disinfectant residual decay leading to potential biological instability. To comprehensively assess the potential for biological instability in a large chlorinated DWDS, a tool-box of bacterial biomass and activity parameters was applied, introducing bacterial community turnover times (BaCTT) as a direct, sensitive and easy-to-interpret quantitative parameter based on the combination of 3H-leucine incorporation with bacterial biomass. Using BaCTT, hotspots and periods of bacterial growth and potential biological instability could be identified in the DWDS that is fed by water with high bacterial growth potential. A de-coupling of biomass from activity parameters was observed, suggesting that bacterial biomass parameters depict seasonally fluctuating raw water quality rather than processes related to biological stability of the finished water in the DWDS. BaCTT, on the other hand, were significantly correlated to water age, disinfectant residual, temperature and a seasonal factor, indicating a higher potential of biological instability at more distant sampling sites and later in the year. As demonstrated, BaCTT is suggested as a novel, sensitive and very useful parameter for assessing the biological instability potential. However, additional studies in other DWDSs are needed to investigate the general applicability of BaCTT depending on water source, applied treatment processes, biofilm growth potential on different pipe materials, or size, age and complexity of the DWDS.
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Affiliation(s)
- Lena Campostrini
- Medical University of Vienna, Centre for Pathophysiology, Infectiology and Immunology, Institute for Hygiene and Applied Immunology - Water Microbiology, Kinderspitalgasse 15, Vienna A-1090, Austria; Interuniversity Cooperation Centre Water & Health, Austria
| | - Philipp Proksch
- University of Natural Resources and Life Sciences, Vienna, Institute of Sanitary Engineering and Water Pollution Control, Muthgasse 18, Vienna A-1190, Austria
| | - Stefan Jakwerth
- Medical University of Vienna, Centre for Pathophysiology, Infectiology and Immunology, Institute for Hygiene and Applied Immunology - Water Microbiology, Kinderspitalgasse 15, Vienna A-1090, Austria; Interuniversity Cooperation Centre Water & Health, Austria
| | - Andreas H Farnleitner
- Interuniversity Cooperation Centre Water & Health, Austria; Division Water Quality and Health, Karl Landsteiner University of Health Sciences, Dr. Karl Dorrek-Straße 30, Krems A-3500, Austria; Technische Universität Wien, Institute for Chemical, Environmental and Bioscience Engineering, Research Group Microbiology and Molecular Diagnostics 166/5/3, Gumpendorferstraße 1, Vienna A-1060, Austria
| | - Alexander K T Kirschner
- Medical University of Vienna, Centre for Pathophysiology, Infectiology and Immunology, Institute for Hygiene and Applied Immunology - Water Microbiology, Kinderspitalgasse 15, Vienna A-1090, Austria; Interuniversity Cooperation Centre Water & Health, Austria; Division Water Quality and Health, Karl Landsteiner University of Health Sciences, Dr. Karl Dorrek-Straße 30, Krems A-3500, Austria.
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Lima Â, Muzny CA, Cerca N. An Indirect Fluorescence Microscopy Method to Assess Vaginal Lactobacillus Concentrations. Microorganisms 2024; 12:114. [PMID: 38257941 PMCID: PMC10820742 DOI: 10.3390/microorganisms12010114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 12/12/2023] [Accepted: 12/13/2023] [Indexed: 01/24/2024] Open
Abstract
Lactobacillus species are the main colonizers of the vaginal microbiota in healthy women. Their absolute quantification by culture-based methods is limited due to their fastidious growth. Flow cytometry can quantify the bacterial concentration of these bacteria but requires the acquisition of expensive equipment. More affordable non-culturable methods, such as fluorescence microscopy, are hampered by the small size of the bacteria. Herein, we developed an indirect fluorescence microscopy method to determine vaginal lactobacilli concentration by determining the correlation between surface area bacterial measurement and initial concentration of an easily cultivable bacterium (Escherichia coli) and applying it to lactobacilli fluorescence microscopy counts. In addition, vaginal lactobacilli were quantified by colony-forming units and flow cytometry in order to compare these results with the indirect method results. The colony-forming-unit values were lower than the results obtained from the other two techniques, while flow cytometry and fluorescence microscopy results agreed. Thus, our developed method was able to accurately quantify vaginal lactobacilli.
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Affiliation(s)
- Ângela Lima
- Laboratory of Research in Biofilms Rosário Oliveira (LIBRO), Centre of Biological Engineering (CEB), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal;
| | - Christina A. Muzny
- Division of Infectious Diseases, University of Alabama at Birmingham, Birmingham, AL 35233, USA;
| | - Nuno Cerca
- Laboratory of Research in Biofilms Rosário Oliveira (LIBRO), Centre of Biological Engineering (CEB), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal;
- LABBELS—Associate Laboratory, 4710-057 Braga, Portugal
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9
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Priyadarsini M, Kushwaha J, Pandey KP, Rani J, Dhoble AS. Application of flow cytometry for rapid, high-throughput, multiparametric analysis of environmental microbiomes. J Microbiol Methods 2023; 214:106841. [PMID: 37832922 DOI: 10.1016/j.mimet.2023.106841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 10/06/2023] [Accepted: 10/08/2023] [Indexed: 10/15/2023]
Abstract
Quantification of the abundance and understanding of the dynamics of the microbial communities is essential to establish a basis for microbiome characterization. The conventional techniques used for the quantification of microbes are complicated and time-consuming. With scientific advancement, many techniques evolved and came into account. Among them, flow cytometry is a robust, high-throughput technique through which microbial dynamics, morphology, microbial distribution, physiological characteristics, and many more attributes can be studied in a high-throughput manner with comparatively less time and resources. Flow cytometry, when combined with other omics-based methods, offers a rapid and efficient platform to analyze and understand the composition of microbiome at the cellular level. The microbial diversity observed through flow cytometry will not be equivalent to that obtained by sequencing methods, but this integrated approach holds great potential for high throughput characterization of microbiomes. Flow cytometry is regarded as an established characterization tool in haematology, oncology, immunology, and medical microbiology research; however, its application in environmental microbiology is yet to be explored. This comprehensive review aims to delve into the diverse environmental applications of flow cytometry across various domains, including but not limited to bioremediation, landfills, anaerobic digestion, industrial bioprocesses, water quality regulation, and soil quality regulation. By conducting an in-depth analysis, this article seeks to shed light on the potential benefits and challenges associated with the utilization of flow cytometry in addressing environmental concerns.
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Affiliation(s)
- Madhumita Priyadarsini
- School of Biochemical Engineering, Indian Institute of Technology (BHU), Varanasi 221005, Uttar Pradesh, India
| | - Jeetesh Kushwaha
- School of Biochemical Engineering, Indian Institute of Technology (BHU), Varanasi 221005, Uttar Pradesh, India
| | - Kailash Pati Pandey
- School of Biochemical Engineering, Indian Institute of Technology (BHU), Varanasi 221005, Uttar Pradesh, India
| | - Jyoti Rani
- School of Biochemical Engineering, Indian Institute of Technology (BHU), Varanasi 221005, Uttar Pradesh, India
| | - Abhishek S Dhoble
- School of Biochemical Engineering, Indian Institute of Technology (BHU), Varanasi 221005, Uttar Pradesh, India.
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10
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Wallace ML, Tallarida N, Schubert WW, Lambert J. Life Detection on Icy Moons Using Flow Cytometry and Exogenous Fluorescent Stains. ASTROBIOLOGY 2023; 23:1071-1082. [PMID: 37672625 DOI: 10.1089/ast.2023.0016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
Flow cytometry is a potential technology for in situ life detection on icy moons (such as Enceladus and Europa) and on the polar ice caps of Mars. We developed a method for using flow cytometry to positively identify four classes of biomarkers using exogenous fluorescent stains: nucleic acids, proteins, carbohydrates, and lipids. We demonstrated the effectiveness of exogenous stains with six known organisms and known abiotic material and showed that the cytometer is easily able to distinguish between the known organisms and the known abiotic material using the exogenous stains. To simulate a life-detection experiment on an icy world lander, we used six natural samples with unknown biotic and abiotic content. We showed that flow cytometry can identify all four biomarkers using the exogenous stains and can separate the biotic material from the known abiotic material on scatter plots. Exogenous staining techniques would likely be used in conjunction with intrinsic fluorescence, clustering, and sorting for a more complete and capable life-detection instrument on an icy moon lander.
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Affiliation(s)
- Matthew L Wallace
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Nicholas Tallarida
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Wayne W Schubert
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - James Lambert
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
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11
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Hasanin G, Mosquera AM, Emwas AH, Altmann T, Das R, Buijs PJ, Vrouwenvelder JS, Gonzalez-Gil G. The microbial growth potential of antiscalants used in seawater desalination. WATER RESEARCH 2023; 233:119802. [PMID: 36871379 DOI: 10.1016/j.watres.2023.119802] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2022] [Revised: 02/10/2023] [Accepted: 02/23/2023] [Indexed: 06/18/2023]
Abstract
20 years since the first report on the biofouling potential of chemicals used for scale control, still, antiscalants with high bacterial growth potential are used in practice. Evaluating the bacterial growth potential of commercially available antiscalants is therefore essential for a rational selection of these chemicals. Previous antiscalant growth potential tests were conducted in drinking water or seawater inoculated with model bacterial species which do not represent natural bacterial communities. To reflect better on the conditions of desalination systems, we investigated the bacterial growth potential of eight different antiscalants in natural seawater and an autochthonous bacterial population as inoculum. The antiscalants differed strongly in their bacterial growth potential varying from ≤ 1 to 6 μg easily biodegradable C equivalents/mg antiscalant. The six phosphonate-based antiscalants investigated showed a broad range of growth potential, which depended on their chemical composition, whilst the biopolymer and the synthetic carboxylated polymers-based antiscalants showed limited or no significant bacterial growth. Moreover, nuclear magnetic resonance (NMR) scans enabled antiscalant fingerprinting, identifying components and contaminants, providing a rapid and sensitive characterization, and opening opportunities for rational selection of antiscalants for biofouling control.
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Affiliation(s)
- Ghadeer Hasanin
- Biological and Environmental Science and Engineering Division (BESE), Water Desalination and Reuse Center (WDRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Ana Maria Mosquera
- Biological and Environmental Science and Engineering Division (BESE), Water Desalination and Reuse Center (WDRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Abdul-Hamid Emwas
- Advanced Nanofabrication Imaging and Characterization, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Thomas Altmann
- Innovation and New Technology, ACWA Power, 41st Floor, The One Tower, Barsha Heights, Sheikh Zayed Road, Dubai, United Arab Emirates
| | - Ratul Das
- Innovation and New Technology, ACWA Power, 41st Floor, The One Tower, Barsha Heights, Sheikh Zayed Road, Dubai, United Arab Emirates.
| | - Paulus J Buijs
- Biological and Environmental Science and Engineering Division (BESE), Water Desalination and Reuse Center (WDRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Johannes S Vrouwenvelder
- Biological and Environmental Science and Engineering Division (BESE), Water Desalination and Reuse Center (WDRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Graciela Gonzalez-Gil
- Biological and Environmental Science and Engineering Division (BESE), Water Desalination and Reuse Center (WDRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.
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12
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Vucinic L, O'Connell D, Dubber D, Coxon C, Gill L. Multiple fluorescence approaches to identify rapid changes in microbial indicators at karst springs. JOURNAL OF CONTAMINANT HYDROLOGY 2023; 254:104129. [PMID: 36634484 DOI: 10.1016/j.jconhyd.2022.104129] [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: 05/24/2022] [Revised: 12/28/2022] [Accepted: 12/29/2022] [Indexed: 06/17/2023]
Abstract
Karst springs are globally important for drinking water supply but are often also exceptionally vulnerable to contamination. Such springs usually exhibit strong variation in microbial water quality in sharp response to rainfall events, thus, posing a health hazard to consumers of water supplied from these sources. The rapid detection of such changes is extremely important as well as being able to establish a link to the sources of such pollution, so that appropriate measures can be taken both in terms of immediate protection of human health and the management of karst aquifers. In this study, a fluorescence-based multi-parameter approach was trialed in order to evaluate which methods can be used to monitor rainfall-induced rapid changes in microbial water quality at karst springs, as well as determine whether such changes can be linked to sources of human effluent contamination. The results from three monitoring periods at two karst springs revealed marked responses to rainfall events for all of the microbial parameters measured. Total cell count (TCC) measurements using flow cytometry (FCM) showed very strong positive correlations with the more conventionally monitored faecal indicator bacteria (FIB) and total coliforms (TC), indicating that such a fluorescence-based and cultivation-independent technique can be very useful to indicate rapid changes in microbial water quality at karst springs. Furthermore, very strong positive correlations were also found between tryptophan-like fluorescence (TLF) measurements and concentrations of all monitored microbial parameters, again demonstrating that such a fluorescence-based approach can also be useful for detecting rapid changes in concentrations of traditional faecal indicators. Interestingly, it was found that fluorescent whitening compounds (FWCs) signals do not necessarily follow temporal variations of microbial indicators. However, the frequency of detection of positive FWCs signals may still reveal useful information about the overall magnitude of human wastewater effluent impacts on karst aquifer systems.
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Affiliation(s)
- Luka Vucinic
- Department of Civil, Structural and Environmental Engineering, University of Dublin, Trinity College, Dublin, Ireland.
| | - David O'Connell
- Department of Civil, Structural and Environmental Engineering, University of Dublin, Trinity College, Dublin, Ireland
| | - Donata Dubber
- Department of Civil, Structural and Environmental Engineering, University of Dublin, Trinity College, Dublin, Ireland
| | - Catherine Coxon
- Department of Geology, Trinity Centre for the Environment, University of Dublin, Trinity College, Dublin, Ireland
| | - Laurence Gill
- Department of Civil, Structural and Environmental Engineering, University of Dublin, Trinity College, Dublin, Ireland
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13
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Vosloo S, Huo L, Chauhan U, Cotto I, Gincley B, Vilardi KJ, Yoon B, Bian K, Gabrielli M, Pieper KJ, Stubbins A, Pinto AJ. Gradual Recovery of Building Plumbing-Associated Microbial Communities after Extended Periods of Altered Water Demand during the COVID-19 Pandemic. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:3248-3259. [PMID: 36795589 PMCID: PMC9969676 DOI: 10.1021/acs.est.2c07333] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 02/06/2023] [Accepted: 02/06/2023] [Indexed: 06/18/2023]
Abstract
COVID-19 pandemic-related building restrictions heightened drinking water microbiological safety concerns post-reopening due to the unprecedented nature of commercial building closures. Starting with phased reopening (i.e., June 2020), we sampled drinking water for 6 months from three commercial buildings with reduced water usage and four occupied residential households. Samples were analyzed using flow cytometry and full-length 16S rRNA gene sequencing along with comprehensive water chemistry characterization. Prolonged building closures resulted in 10-fold higher microbial cell counts in the commercial buildings [(2.95 ± 3.67) × 105 cells mL-1] than in residential households [(1.11 ± 0.58) × 104 cells mL-1] with majority intact cells. While flushing reduced cell counts and increased disinfection residuals, microbial communities in commercial buildings remained distinct from those in residential households on the basis of flow cytometric fingerprinting [Bray-Curtis dissimilarity (dBC) = 0.33 ± 0.07] and 16S rRNA gene sequencing (dBC = 0.72 ± 0.20). An increase in water demand post-reopening resulted in gradual convergence in microbial communities in water samples collected from commercial buildings and residential households. Overall, we find that the gradual recovery of water demand played a key role in the recovery of building plumbing-associated microbial communities as compared to short-term flushing after extended periods of reduced water demand.
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Affiliation(s)
- Solize Vosloo
- Department
of Civil and Environmental Engineering, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 021115, United States
| | - Linxuan Huo
- School
of Civil and Environmental Engineering, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, Georgia 30318, United States
| | - Umang Chauhan
- Department
of Civil and Environmental Engineering, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 021115, United States
| | - Irmarie Cotto
- Department
of Civil and Environmental Engineering, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 021115, United States
| | - Benjamin Gincley
- School
of Civil and Environmental Engineering, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, Georgia 30318, United States
| | - Katherine J. Vilardi
- Department
of Civil and Environmental Engineering, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 021115, United States
| | - Bryan Yoon
- Department
of Civil and Environmental Engineering, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 021115, United States
| | - Kaiqin Bian
- School
of Civil and Environmental Engineering, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, Georgia 30318, United States
| | - Marco Gabrielli
- Dipartimento
di Ingegneria Civile e Ambientale - Sezione Ambientale, Politecnico di Milano, 20133 Milan, Italy
| | - Kelsey J. Pieper
- Department
of Civil and Environmental Engineering, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 021115, United States
| | - Aron Stubbins
- Department
of Civil and Environmental Engineering, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 021115, United States
| | - Ameet J. Pinto
- School
of Civil and Environmental Engineering, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, Georgia 30318, United States
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14
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Liu X, Pollner B, Paulitsch-Fuchs AH, Fuchs EC, Dyer NP, Loiskandl W, Lass-Flörl C. Investigation of the effect of sustainable magnetic treatment on the microbiological communities in drinking water. ENVIRONMENTAL RESEARCH 2022; 213:113638. [PMID: 35705130 DOI: 10.1016/j.envres.2022.113638] [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: 05/13/2022] [Accepted: 06/05/2022] [Indexed: 06/15/2023]
Abstract
The drinking water scarcity is posing a threat to mankind, hence better water quality management methods are required. Magnetic water treatment, which has been reported to improve aesthetic water quality and reduce scaling problems, can be an important addition to the traditional disinfectant dependent treatment. Despite the extensive market application opportunities, the effect of magnetic fields on (microbial) drinking water communities and subsequently the biostability is still largely unexplored, although the first patent was registered already 1945. Here flow cytometry was applied to assess the effect of weak magnetic fields (≤10 G) with strong gradients (≈800 G/m) on drinking water microbial communities. Drinking water was collected from the tap and placed inside the magnetic field (treated) and 5 m away from the magnet to avoid any background interferences (control) using both a static set-up and a shaking set-up. Samples were collected during a seven-day period for flow cytometry examination. Additionally, the effects of magnetic fields on the growth of Pseudomonas aeruginosa in autoclaved tap water were examined. Based on the fluorescent intensity of the stained nucleic acid content, the microbial cells were grouped into low nucleic acid content (LNA) and high nucleic acid content (HNA). Our results show that the LNA was dominant under nutrient limited condition while the HNA dominates when nutrient is more available. Such behavior of LNA and HNA matches well with the long discussed r/K selection model where r-strategists adapted to eutrophic conditions and K-strategists adapted to oligotrophic conditions. The applied magnetic fields selectively promote the growth of LNA under nutrient rich environment, which indicates a beneficial effect on biostability enhancement. Inhibition on an HNA representative Pseudomonas aeruginosa has also been observed. Based on our laboratory observations, we conclude that magnetic field treatment can be a sustainable method for microbial community management with great potential.
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Affiliation(s)
- Xiaoxia Liu
- Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden, the Netherlands; Institute of Soil Physics and Rural Water Management, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Bernhard Pollner
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Astrid H Paulitsch-Fuchs
- Diagnostic and Research Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Neue Stiftingtalstraße 2, 8010, Graz, Austria; Carinthia University of Applied Sciences, Biomedical Science, St. Veiterstraße 47, 9020 Klagenfurt, Austria
| | - Elmar C Fuchs
- Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden, the Netherlands; Optical Sciences Group, Faculty of Science and Technology (TNW), University of Twente, Drienerlolaan 5, 7522NB Enschede, the Netherlands.
| | - Nigel P Dyer
- Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden, the Netherlands; Coherent Water Systems, 2 Crich Avenue, DE23 6ES Derby, United Kingdom
| | - Willibald Loiskandl
- Institute of Soil Physics and Rural Water Management, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Cornelia Lass-Flörl
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
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15
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Vucinic L, O’Connell D, Teixeira R, Coxon C, Gill L. Flow Cytometry and Fecal Indicator Bacteria Analyses for Fingerprinting Microbial Pollution in Karst Aquifer Systems. WATER RESOURCES RESEARCH 2022; 58:e2021WR029840. [PMID: 35859924 PMCID: PMC9285701 DOI: 10.1029/2021wr029840] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/23/2022] [Accepted: 04/01/2022] [Indexed: 06/15/2023]
Abstract
Microbial pollution of aquifers is a persistent water quality problem globally which poses significant risks to public health. Karst aquifer systems are exceptionally vulnerable to pollution from fecal contamination sources as a result of rapid recharge of water from the surface via discrete pathways linked to highly conductive, solutionally enlarged conduits alongside strong aquifer heterogeneity. Consequently, rapid changes in microbial water quality, which are difficult to monitor with expensive and time-consuming conventional microbiological methods, are a major concern in karst environments. This study examined flow cytometric (FCM) fingerprinting of bacterial cells in groundwater together with fecal indicator bacteria (FIB) at nine separate karst springs of varying catchment size over a 14 month period in order to assess whether such a technique can provide faster and more descriptive information about microbial pollution through such karst aquifer systems. Moreover, the data have also been evaluated with respect to the potential of using turbidity as an easy-to-measure proxy indicator of microbial pollution in a novel way. We argue that FCM provides additional data from which enhanced insights into fecal pollution sources and its fate and transport in such karst catchments can be gained. We also present valuable new information on the potential and limitations of turbidity as an indicator of fecal groundwater contamination in karst. FCM has the potential to become a more widely used tool in the field of contaminant hydrogeology.
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Affiliation(s)
- Luka Vucinic
- Department of Civil, Structural and Environmental EngineeringUniversity of DublinTrinity CollegeDublinIreland
| | - David O’Connell
- Department of Civil, Structural and Environmental EngineeringUniversity of DublinTrinity CollegeDublinIreland
| | - Rui Teixeira
- Department of Civil, Structural and Environmental EngineeringUniversity of DublinTrinity CollegeDublinIreland
| | - Catherine Coxon
- Department of Geology and Trinity Centre for the EnvironmentUniversity of DublinTrinity CollegeDublinIreland
| | - Laurence Gill
- Department of Civil, Structural and Environmental EngineeringUniversity of DublinTrinity CollegeDublinIreland
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16
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Pereira AC, Tenreiro A, Cunha MV. When FLOW-FISH met FACS: Combining multiparametric, dynamic approaches for microbial single-cell research in the total environment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:150682. [PMID: 34600998 DOI: 10.1016/j.scitotenv.2021.150682] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 09/22/2021] [Accepted: 09/26/2021] [Indexed: 06/13/2023]
Abstract
In environmental microbiology, the ability to assess, in a high-throughput way, single-cells within microbial communities is key to understand their heterogeneity. Fluorescence in situ hybridization (FISH) uses fluorescently labeled oligonucleotide probes to detect, identify, and quantify single cells of specific taxonomic groups. The combination of Flow Cytometry (FLOW) with FISH (FLOW-FISH) enables high-throughput quantification of complex whole cell populations, which when associated with fluorescence-activated cell sorting (FACS) enables sorting of target microorganisms. These sorted cells may be investigated in many ways, for instance opening new avenues for cytomics at a single-cell scale. In this review, an overview of FISH and FLOW methodologies is provided, addressing conventional methods, signal amplification approaches, common fluorophores for cell physiology parameters evaluation, and model variation techniques as well. The coupling of FLOW-FISH-FACS is explored in the context of different downstream applications of sorted cells. Current and emerging applications in environmental microbiology to outline the interactions and processes of complex microbial communities within soil, water, animal microbiota, polymicrobial biofilms, and food samples, are described.
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Affiliation(s)
- André C Pereira
- Centre for Ecology, Evolution and Environmental Changes (cE3c), Faculdade de Ciências da Universidade de Lisboa, Lisboa, Portugal; Biosystems & Integrative Sciences Institute (BioISI), Faculdade de Ciências da Universidade de Lisboa, Lisboa, Portugal
| | - Ana Tenreiro
- Biosystems & Integrative Sciences Institute (BioISI), Faculdade de Ciências da Universidade de Lisboa, Lisboa, Portugal
| | - Mónica V Cunha
- Centre for Ecology, Evolution and Environmental Changes (cE3c), Faculdade de Ciências da Universidade de Lisboa, Lisboa, Portugal; Biosystems & Integrative Sciences Institute (BioISI), Faculdade de Ciências da Universidade de Lisboa, Lisboa, Portugal.
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17
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Lindivat M, Bratbak G, Larsen A, Hess-Erga OK, Hoell IA. Flow Cytometric Analysis of Bacterial Protein Synthesis: Monitoring Vitality After Water Treatment. Front Microbiol 2021; 12:772651. [PMID: 34956134 PMCID: PMC8702973 DOI: 10.3389/fmicb.2021.772651] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 11/12/2021] [Indexed: 11/13/2022] Open
Abstract
Bacterial vitality after water disinfection treatment was investigated using bio-orthogonal non-canonical amino acid tagging (BONCAT) and flow cytometry (FCM). Protein synthesis activity and DNA integrity (BONCAT–SYBR Green) was monitored in Escherichia coli monocultures and in natural marine samples after UV irradiation (from 25 to 200 mJ/cm2) and heat treatment (from 15 to 45 min at 55°C). UV irradiation of E. coli caused DNA degradation followed by the decrease in protein synthesis within a period of 24 h. Heat treatment affected both DNA integrity and protein synthesis immediately, with an increased effect over time. Results from the BONCAT method were compared with results from well-known methods such as plate counts (focusing on growth) and LIVE/DEAD™ BacLight™ (focusing on membrane permeability). The methods differed somewhat with respect to vitality levels detected in bacteria after the treatments, but the results were complementary and revealed that cells maintained metabolic activity and membrane integrity despite loss of cell division. Similarly, analysis of protein synthesis in marine bacteria with BONCAT displayed residual activity despite inability to grow or reproduce. Background controls (time zero blanks) prepared using different fixatives (formaldehyde, isopropanol, and acetic acid) and several different bacterial strains revealed that the BONCAT protocol still resulted in labeled, i.e., apparently active, cells. The reason for this is unclear and needs further investigation to be understood. Our results show that BONCAT and FCM can detect, enumerate, and differentiate bacterial cells after physical water treatments such as UV irradiation and heating. The method is reliable to enumerate and explore vitality of single cells, and a great advantage with BONCAT is that all proteins synthesized within cells are analyzed, compared to assays targeting specific elements such as enzyme activity.
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Affiliation(s)
- Mathilde Lindivat
- Faculty of Engineering and Science, Institute of Safety, Chemistry and Biomedical Laboratory Sciences, Western Norway University of Applied Sciences, Haugesund, Norway
| | - Gunnar Bratbak
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | - Aud Larsen
- Department of Biological Sciences, University of Bergen, Bergen, Norway.,NORCE Environment, NORCE Norwegian Research Center AS, Bergen, Norway
| | | | - Ingunn Alne Hoell
- Faculty of Engineering and Science, Institute of Safety, Chemistry and Biomedical Laboratory Sciences, Western Norway University of Applied Sciences, Haugesund, Norway
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18
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Multiscale Convergence of the Inverse Problem for Chemotaxis in the Bayesian Setting. COMPUTATION 2021. [DOI: 10.3390/computation9110119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Chemotaxis describes the movement of an organism, such as single or multi-cellular organisms and bacteria, in response to a chemical stimulus. Two widely used models to describe the phenomenon are the celebrated Keller–Segel equation and a chemotaxis kinetic equation. These two equations describe the organism’s movement at the macro- and mesoscopic level, respectively, and are asymptotically equivalent in the parabolic regime. The way in which the organism responds to a chemical stimulus is embedded in the diffusion/advection coefficients of the Keller–Segel equation or the turning kernel of the chemotaxis kinetic equation. Experiments are conducted to measure the time dynamics of the organisms’ population level movement when reacting to certain stimulation. From this, one infers the chemotaxis response, which constitutes an inverse problem. In this paper, we discuss the relation between both the macro- and mesoscopic inverse problems, each of which is associated with two different forward models. The discussion is presented in the Bayesian framework, where the posterior distribution of the turning kernel of the organism population is sought. We prove the asymptotic equivalence of the two posterior distributions.
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19
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Favere J, Waegenaar F, Boon N, De Gusseme B. Online microbial monitoring of drinking water: How do different techniques respond to contaminations in practice? WATER RESEARCH 2021; 202:117387. [PMID: 34243050 DOI: 10.1016/j.watres.2021.117387] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 06/18/2021] [Accepted: 06/21/2021] [Indexed: 06/13/2023]
Abstract
Safeguarding the microbial water quality remains a challenge for drinking water utilities, and because of population growth and climate change, new issues arise regularly. To overcome these problems, biostable drinking water production and water reuse will become increasingly important. In this respect, high-resolution online microbial monitoring during treatment and distribution could prove essential. Here, we present the first scientific and practical comparison of multiple online microbial monitoring techniques in which six commercially available devices were set up in a full-scale drinking water production plant. Both the devices' response towards operational changes and contaminations, as well as their detection limit for different contaminations were evaluated and compared. During normal operation, all devices were able to detect abrupt operational changes such as backwashing of activated carbon filters and interruption of the production process in a fast and sensitive way. To benchmark their response to contaminations, the calculation of a dynamic baseline for sensitive separation between noise and events is proposed. In order of sensitivity, enzymatic analysis, ATP measurement, and flow cytometric fingerprinting were the most performant for detection of rain- and groundwater contaminations (0.01 - 0.1 v%). On the other hand, optical classification and flow cytometric cell counts showed to be more robust techniques, requiring less maintenance and providing direct information about the cell concentration, even though they were still more sensitive than plate counting. The choice for a certain technology will thus depend on the type of application and is a balance between sensitivity, price and maintenance. All things considered, a combination of several devices and use of advanced data analysis such as fingerprinting may be of added value. In general, the strategic implementation of online microbial monitoring as early-warning system will allow for intensive quality control by high-frequency sampling as well as a short event response timeframe.
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Affiliation(s)
- Jorien Favere
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, B-9000 Gent, Belgium; Centre for Advanced Process Technology for Urban Resource Recovery (CAPTURE), P.O., Frieda Saeysstraat 1, B-9000 Gent, Belgium
| | - Fien Waegenaar
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, B-9000 Gent, Belgium; Centre for Advanced Process Technology for Urban Resource Recovery (CAPTURE), P.O., Frieda Saeysstraat 1, B-9000 Gent, Belgium
| | - Nico Boon
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, B-9000 Gent, Belgium; Centre for Advanced Process Technology for Urban Resource Recovery (CAPTURE), P.O., Frieda Saeysstraat 1, B-9000 Gent, Belgium
| | - Bart De Gusseme
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, B-9000 Gent, Belgium; Centre for Advanced Process Technology for Urban Resource Recovery (CAPTURE), P.O., Frieda Saeysstraat 1, B-9000 Gent, Belgium.
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20
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La Spina R, António DC, Bombera R, Lettieri T, Lequarré AS, Colpo P, Valsesia A. New Detection Platform for Screening Bacteria in Liquid Samples. BIOSENSORS 2021; 11:142. [PMID: 34062907 PMCID: PMC8147366 DOI: 10.3390/bios11050142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 04/21/2021] [Accepted: 04/28/2021] [Indexed: 11/26/2022]
Abstract
The development of sensitive methods for the determination of potential bacterial contamination is of upmost importance for environmental monitoring and food safety. In this study, we present a new method combining a fast pre-enrichment step using a microporous cryogel and a detection and identification step using antimicrobial peptides (AMPs) and labelled antibodies, respectively. The experimental method consists of: (i) the capture of large amounts of bacteria from liquid samples by using a highly porous and functionalized cryogel; (ii) the detection and categorisation of Gram-positive and Gram-negative bacteria by determining their affinities toward a small set of AMPs; and (iii) the identification of the bacterial strain by using labelled detection antibodies. As proof of concept, the assessment of the three steps of the analysis was performed by using Escherichia coli and Bacillus sp. as models for Gram-negative and Gram-positive bacteria, respectively. The use of AMPs with broad specificity combined with labelled antibodies enabled the detection and potential categorization of a large spectrum of unknown or unexpected bacteria.
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Affiliation(s)
- Rita La Spina
- European Commission, Joint Research Centre (JRC), Ispra, Italy; (R.L.S.); (D.C.A.); (R.B.); (T.L.); (P.C.)
| | - Diana C. António
- European Commission, Joint Research Centre (JRC), Ispra, Italy; (R.L.S.); (D.C.A.); (R.B.); (T.L.); (P.C.)
| | - Radoslaw Bombera
- European Commission, Joint Research Centre (JRC), Ispra, Italy; (R.L.S.); (D.C.A.); (R.B.); (T.L.); (P.C.)
| | - Teresa Lettieri
- European Commission, Joint Research Centre (JRC), Ispra, Italy; (R.L.S.); (D.C.A.); (R.B.); (T.L.); (P.C.)
| | | | - Pascal Colpo
- European Commission, Joint Research Centre (JRC), Ispra, Italy; (R.L.S.); (D.C.A.); (R.B.); (T.L.); (P.C.)
| | - Andrea Valsesia
- European Commission, Joint Research Centre (JRC), Ispra, Italy; (R.L.S.); (D.C.A.); (R.B.); (T.L.); (P.C.)
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21
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Haberkorn I, Off CL, Besmer MD, Buchmann L, Mathys A. Automated Online Flow Cytometry Advances Microalgal Ecosystem Management as in situ, High-Temporal Resolution Monitoring Tool. Front Bioeng Biotechnol 2021; 9:642671. [PMID: 33834018 PMCID: PMC8023406 DOI: 10.3389/fbioe.2021.642671] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 02/19/2021] [Indexed: 12/17/2022] Open
Abstract
Microalgae are emerging as a next-generation biotechnological production system in the pharmaceutical, biofuel, and food domain. The economization of microalgal biorefineries remains a main target, where culture contamination and prokaryotic upsurge are main bottlenecks to impair culture stability, reproducibility, and consequently productivity. Automated online flow cytometry (FCM) is gaining momentum as bioprocess optimization tool, as it allows for spatial and temporal landscaping, real-time investigations of rapid microbial processes, and the assessment of intrinsic cell features. So far, automated online FCM has not been applied to microalgal ecosystems but poses a powerful technology for improving the feasibility of microalgal feedstock production through in situ, real-time, high-temporal resolution monitoring. The study lays the foundations for an application of automated online FCM implying far-reaching applications to impel and facilitate the implementation of innovations targeting at microalgal bioprocesses optimization. It shows that emissions collected on the FL1/FL3 fluorescent channels, harnessing nucleic acid staining and chlorophyll autofluorescence, enable a simultaneous assessment (quantitative and diversity-related) of prokaryotes and industrially relevant phototrophic Chlorella vulgaris in mixed ecosystems of different complexity over a broad concentration range (2.2–1,002.4 cells ⋅μL–1). Automated online FCM combined with data analysis relying on phenotypic fingerprinting poses a powerful tool for quantitative and diversity-related population dynamics monitoring. Quantitative data assessment showed that prokaryotic growth phases in engineered and natural ecosystems were characterized by different growth speeds and distinct peaks. Diversity-related population monitoring based on phenotypic fingerprinting indicated that prokaryotic upsurge in mixed cultures was governed by the dominance of single prokaryotic species. Automated online FCM is a powerful tool for microalgal bioprocess optimization owing to its adaptability to myriad phenotypic assays and its compatibility with various cultivation systems. This allows advancing bioprocesses associated with both microalgal biomass and compound production. Hence, automated online FCM poses a viable tool with applications across multiple domains within the biobased sector relying on single cell–based value chains.
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Affiliation(s)
- Iris Haberkorn
- Sustainable Food Processing Laboratory, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
| | - Cosima L Off
- Sustainable Food Processing Laboratory, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
| | | | - Leandro Buchmann
- Sustainable Food Processing Laboratory, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland.,Bühler AG, Uzwil, Switzerland
| | - Alexander Mathys
- Sustainable Food Processing Laboratory, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
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22
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Merino C, Kuzyakov Y, Godoy K, Jofré I, Nájera F, Matus F. Iron-reducing bacteria decompose lignin by electron transfer from soil organic matter. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 761:143194. [PMID: 33183799 DOI: 10.1016/j.scitotenv.2020.143194] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 10/11/2020] [Accepted: 10/17/2020] [Indexed: 06/11/2023]
Abstract
Iron-reducing bacteria (IRB) are crucial for electron transfer in anaerobic soil microsites. The utilization of the energy gathered by this mechanism by decomposers of organic matter is a challenging and fascinating issue. We hypothesized that bacteria reducing Fe(III) (oxyhydr)oxides to soluble Fe(II) obtain electrons from reduced soil organic matter (SOMr) involving lignin oxidation. Iron-reducing bacteria were isolated from topsoils of various climates (humid temperate, cold temperate, subpolar), vegetation types (mostly grasslands and forests), and derived from various parent materials treatments assigned as Granitic, Volcanic-allophanic, Fluvio-glacial, Basaltic-Antarctic and Metamorphic. After the screening of IRB by phospholipid fatty acid (PLFA) analysis and PCR identification (full-length 16S rDNA), the IRB were inoculated to 20 samples (five soils and 4 replicates) and a broad range of parallel processes were traced. Geobacter metallireducens and Geobacter lovleyi were the main Geobacteraceae-strains present in all soils and strongly increased the activity of ligninolytic enzymes: lignin peroxidase and manganese peroxidase. Carbon dioxide (CO2) released from IRB-inoculated soils was 140% higher than that produced by Fenton reactions (induced by H2O2 and Fe(II) addition) but 40% lower than in non-sterile soils. CO2 release was closely correlated with the produced Fe (II) and H2O2 consumption. The highest CO2 was released from Basaltic-Antarctic soils with the highest Fe content and was closely correlated with lignin depolymerization (detection by fluorescence images). All IRB oxidized the lignin contained in the SOM within a wide pH range and in soils from all parent materials. We present a conceptual model showing electron shuttling from SOM containing lignin (as a C and energy source) to IRB to produce energy and promote Fe(III) (oxyhydr)oxides reduction was proposed and discussed.
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Affiliation(s)
- Carolina Merino
- Center of Plant, Soil Interaction and Natural Resources Biotechnology Scientific and Technological Bioresource Nucleus (BIOREN), Temuco, Chile; Laboratory of Conservation and Dynamics of Volcanic Soils, Department of Chemical Sciences and Natural Resources, Universidad de La Frontera, Temuco, Chile; Network for Extreme Environmental Research, Universidad de la Frontera, Temuco, Chile
| | - Yakov Kuzyakov
- Network for Extreme Environmental Research, Universidad de la Frontera, Temuco, Chile; Soil Science of Temperate Ecosystems, Büsgen Institute, Georg-August-Universität Göttingen, Germany; Institute of Environmental Sciences, Kazan Federal University, Kazan, Russia; RUDN, Moscow, Russia
| | - Karina Godoy
- Center of Plant, Soil Interaction and Natural Resources Biotechnology Scientific and Technological Bioresource Nucleus (BIOREN), Temuco, Chile
| | - Ignacio Jofré
- Laboratory of Conservation and Dynamics of Volcanic Soils, Department of Chemical Sciences and Natural Resources, Universidad de La Frontera, Temuco, Chile
| | - Francisco Nájera
- PhD Program in Science of Natural Resource Sciences, Universidad de La Frontera, Chile
| | - Francisco Matus
- Laboratory of Conservation and Dynamics of Volcanic Soils, Department of Chemical Sciences and Natural Resources, Universidad de La Frontera, Temuco, Chile; Network for Extreme Environmental Research, Universidad de la Frontera, Temuco, Chile.
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23
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Abstract
Flow cytometry is an important technology for the study of microbial communities. It grants the ability to rapidly generate phenotypic single-cell data that are both quantitative, multivariate and of high temporal resolution. The complexity and amount of data necessitate an objective and streamlined data processing workflow that extends beyond commercial instrument software. No full overview of the necessary steps regarding the computational analysis of microbial flow cytometry data currently exists. In this review, we provide an overview of the full data analysis pipeline, ranging from measurement to data interpretation, tailored toward studies in microbial ecology. At every step, we highlight computational methods that are potentially useful, for which we provide a short nontechnical description. We place this overview in the context of a number of open challenges to the field and offer further motivation for the use of standardized flow cytometry in microbial ecology research.
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Affiliation(s)
| | - Ruben Props
- Center for Microbial Ecology & Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
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24
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Abstract
The aquatic ecosystem is continuously threatened by the infiltration and discharge of anthropogenic wastewaters. This issue requires the unending improvement of monitoring systems to become more comprehensive and specific to targeted pollutants. This review intended to elucidate the overall aspects explored by researchers in developing better water pollution monitoring tools in recent years. The discussion is encircled around three main elements that have been extensively used as the basis for the development of monitoring methods, namely the dissolved compounds, bacterial indicator, and nucleic acids. The latest technologies applied in wastewater and surface water mapped from these key players were reviewed and categorized into physicochemical and compound characterizations, biomonitoring, and molecular approaches in taxonomical and functional analyses. Overall, researchers are continuously rallying to enhance the detection of causal source for water pollution through either conventional or mostly advanced approaches focusing on spectrometry, high-throughput sequencing, and flow cytometry technology among others. From this review’s perspective, each pollution evaluation technology has its own advantages and it would be beneficial for several aspects of pollutants assessments to be combined and established as a complementary package for better aquatic environmental management in the long run.
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25
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Lu N, Sun S, Chu F, Wang M, Zhao Q, Shi J, Jia R. Identification and inactivation of Gordonia, a new chlorine-resistant bacterium isolated from a drinking water distribution system. JOURNAL OF WATER AND HEALTH 2020; 18:995-1008. [PMID: 33328370 DOI: 10.2166/wh.2020.143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Chlorine-resistant bacteria threaten drinking water safety in water distribution systems. In this study, a novel chlorine-resistant bacterium identified as Gordonia was isolated from the drinking water supply system of Jinan City for the first time. We examined the resistance and inactivation of the isolate by investigating cell survival, changes in cell morphology, and the permeability of cell membranes exposed to chlorine. After 240 min chlorine exposure, the chlorine residual was greater than 0.5 mg L-1 and the final inactivation was about 3 log reduction, which showed that the Gordonia strain had high chlorine tolerance. Flow-cytometric analysis indicated that, following sodium hypochlorite treatments with increasing membrane permeability, culturable cells enter a viable but nonculturable state and then die. We also investigated the inactivation kinetics of Gordonia following chlorine dioxide and ultraviolet radiation treatment. We found that these treatments can effectively inactivate Gordonia, which suggests that they may be used for the regulation of chlorine-resistant microorganisms.
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Affiliation(s)
- Nannan Lu
- Shandong Province Water Supply and Drainage Monitoring Center, No.5111, Aotizhong Road, Jinan, China E-mail:
| | - Shaohua Sun
- Shandong Province Water Supply and Drainage Monitoring Center, No.5111, Aotizhong Road, Jinan, China E-mail:
| | - Fumin Chu
- Shandong Province Water Supply and Drainage Monitoring Center, No.5111, Aotizhong Road, Jinan, China E-mail:
| | - Mingquan Wang
- Shandong Province Water Supply and Drainage Monitoring Center, No.5111, Aotizhong Road, Jinan, China E-mail:
| | - Qinghua Zhao
- Shandong Province Water Supply and Drainage Monitoring Center, No.5111, Aotizhong Road, Jinan, China E-mail:
| | - Jinmiao Shi
- Shandong Province Water Supply and Drainage Monitoring Center, No.5111, Aotizhong Road, Jinan, China E-mail:
| | - Ruibao Jia
- Shandong Province Water Supply and Drainage Monitoring Center, No.5111, Aotizhong Road, Jinan, China E-mail:
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26
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McEvoy B, Lynch M, Rowan NJ. Opportunities for the application of real-time bacterial cell analysis using flow cytometry for the advancement of sterilization microbiology. J Appl Microbiol 2020; 130:1794-1812. [PMID: 33155740 DOI: 10.1111/jam.14876] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 09/10/2020] [Accepted: 09/21/2020] [Indexed: 01/11/2023]
Abstract
Medical devices provide critical care and diagnostic applications through patient contact. Sterility assurance level (SAL) may be defined as the probability of a single viable micro-organism occurring on an item after a sterilization process. Sterilization microbiology often relies upon using an overkill validation method where a 12-log reduction in recalcitrant bacterial endospore population occurs during the process that exploits conventional laboratory-based culture media for enumeration. This timely review explores key assumptions underpinning use of conventional culture-based methods in sterilization microbiology. Consideration is given to how such methods may limit the ability to fully appreciate the inactivation kinetics of a sterilization process such as vaporized hydrogen peroxide (VH2O2) sterilization, and consequently design efficient sterilization processes. Specific use of the real-time flow cytometry (FCM) is described by way of elucidating the practical relevance of these limitation factors with implications and opportunities for the sterilization industry discussed. Application of FCM to address these culture-based limitation factors will inform real-time kinetic inactivation modelling and unlock potential to embrace emerging opportunities for pharma, medical device and sterilization industries including potentially disruptive applications that may involve reduced usage of sterilant.
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Affiliation(s)
- B McEvoy
- STERIS Applied Sterilization Technologies, IDA Business and Technology Park, Tullamore, Ireland
| | - M Lynch
- Centre for Disinfection, Sterilization and Biosecurity, Athlone Institute of Technology, Athlone, Ireland
| | - N J Rowan
- Centre for Disinfection, Sterilization and Biosecurity, Athlone Institute of Technology, Athlone, Ireland
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27
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Zhou J, Wang T, Xie X. Locally Enhanced Electric Field Treatment (LEEFT) Promotes the Performance of Ozonation for Bacteria Inactivation by Disrupting the Cell Membrane. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:14017-14025. [PMID: 32940462 DOI: 10.1021/acs.est.0c03968] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The adoption of ozonation for water disinfection is hindered by its high ozone demand and the resulting high cost. Electric field treatment inactivates bacteria by physically disrupting the integrity of the cell membrane. Assisted by nanowire-modified electrodes, locally enhanced electric field treatment (LEEFT) reduces the required voltage to several volts to induce sufficient electric field strength for efficient bacteria inactivation. In this study, the LEEFT is applied as a pretreatment of ozonation for bacteria inactivation. Our results show that a low-voltage (<0.4 V) LEEFT has no obvious effect on the following ozonation, but a higher-voltage (0.6-1.2 V) LEEFT significantly enhances the ozone inactivation. After the LEEFT, a large number of viable cells with impaired cell membranes are observed, shown by both selective plate count and staining methods. The mechanism inducing the enhancement is explained by the initially reparable pores generated by LEEFT that cannot recover in the subsequent ozonation and the greater intracellular diffusion of ozone after the membrane disruption induced by LEEFT. The application of LEEFT as a pretreatment process is beneficial to reduce the ozone dosage and disinfection by-product formation with a broader inactivation spectrum, which facilitates the application of ozonation in primary water disinfection.
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Affiliation(s)
- Jianfeng Zhou
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Ting Wang
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Xing Xie
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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28
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Computational flow cytometry of planktonic populations for the evaluation of microbiological-control programs in district cooling plants. Sci Rep 2020; 10:13299. [PMID: 32764596 PMCID: PMC7411017 DOI: 10.1038/s41598-020-70198-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 07/23/2020] [Indexed: 11/08/2022] Open
Abstract
Biofouling poses a serious concern for the district cooling (DC) industry. Current industry practises for monitoring biofouling continue to rely on culture-based methods for microbial enumeration, which are ultimately flawed. Computational flow cytometric (cFCM) analyses, which offer enhanced reproducibility and streamlined analytics versus conventional flow cytometry were applied to samples taken from 3 sites in each of 3 plants over a 5-week sampling program. We asked whether the application of cFCM to monitoring planktonic community dynamics in DC plants could be able to provide sufficient information to enhance microbiological-control strategies at site and inform about plant performance impacts. The use of cFCM enabled the evaluation of biocide dosing, deep cleaning treatment efficiencies and routes of microbial ingress into the studied systems. Additionally, inherent risks arising from the reintroduction of microbiological communities into recently cleaned WCT basins from contaminated cooling waters were identified. However, short-term dynamics did not relate with plant performance metrics. In summary, the insights offered by this approach can inform on plant status, enable evaluations of microbial loads during biofouling mitigation programs and, ultimately, enhance industry management of the biofouling process.
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29
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Kundu K, Weber N, Griebler C, Elsner M. Phenotypic heterogeneity as key factor for growth and survival under oligotrophic conditions. Environ Microbiol 2020; 22:3339-3356. [PMID: 32500958 DOI: 10.1111/1462-2920.15106] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 04/09/2020] [Accepted: 05/28/2020] [Indexed: 11/26/2022]
Abstract
Productivity-poor oligotrophic environments are plentiful on earth. Yet it is not well understood how organisms maintain population sizes under these extreme conditions. Most scenarios consider the adaptation of a single microorganism (isogenic) at the cellular level, which increases their fitness in such an environment. However, in oligotrophic environments, the adaptation of microorganisms at population level - that is, the ability of living cells to differentiate into subtypes with specialized attributes leading to the coexistence of different phenotypes in isogenic populations - remains a little-explored area of microbiology research. In this study, we performed experiments to demonstrate that an isogenic population differentiated to two subpopulations under low energy-flux in chemostats. Fluorescence cytometry and turnover rates revealed that these subpopulations differ in their nucleic acid content and metabolic activity. A mechanistic modelling framework for the dynamic adaptation of microorganisms with the consideration of their ability to switch between different phenotypes was experimentally calibrated and validated. Simulation of hypothetical scenarios suggests that responsive diversification upon a change in energy availability offers a competitive advantage over homogenous adaptation for maintaining viability and metabolic activity with time.
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Affiliation(s)
- Kankana Kundu
- Institute of Groundwater Ecology, Helmholtz Zentrum Munchen, Ingolstadter Landstraße 1, 85764 Neuherberg, Bavaria, Germany.,Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, Ghent 9000, Belgium
| | - Nina Weber
- Institute of Groundwater Ecology, Helmholtz Zentrum Munchen, Ingolstadter Landstraße 1, 85764 Neuherberg, Bavaria, Germany
| | - Christian Griebler
- Institute of Groundwater Ecology, Helmholtz Zentrum Munchen, Ingolstadter Landstraße 1, 85764 Neuherberg, Bavaria, Germany.,Division of Limnology, University of Vienna, Department of Functional and Evolutionary Ecology, Althanstrasse 14, Vienna, 1090, Austria
| | - Martin Elsner
- Institute of Groundwater Ecology, Helmholtz Zentrum Munchen, Ingolstadter Landstraße 1, 85764 Neuherberg, Bavaria, Germany.,Chair of Analytical Chemistry and Water Chemistry, Technical University of Munich, Marchioninistrasse 17, D-81377 Munich, Germany
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30
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Gnaim R, Golberg A, Sheviryov J, Rubinsky B, González CA. Detection and differentiation of bacteria by electrical bioimpedance spectroscopy. Biotechniques 2020; 69:384-394. [PMID: 32486835 DOI: 10.2144/btn-2019-0080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Detecting bacteria in samples and differentiating between Gram-negative and Gram-positive species is an important challenge, and the most common method, Gram staining, is very time consuming. The aim of this study was to evaluate the electrical bioimpedance spectroscopy (EBIS) technique as an inexpensive and practical tool for real-time detection of bacteria and differentiation between Gram-positive and Gram-negative species. The relevant sensitivity for differentiating between species was found in the magnitude and phase at frequencies of 158,489 and 5248 Hz, respectively, at a bacterial concentration of 1 μg/μl. Subsequently, the sensitivity was estimated as a function of bacterial concentration. Our results demonstrated that EBIS can potentially distinguish between presence and absence of bacteria as well as between different types of bacteria.
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Affiliation(s)
- Rima Gnaim
- Porter School of Environment & Earth Sciences, Tel Aviv University. Tel Aviv-Yafo, Israel.,The Triangle Regional Research & Development Center, Kfar Qari' 30075, Israel
| | - Alexander Golberg
- Porter School of Environment & Earth Sciences, Tel Aviv University. Tel Aviv-Yafo, Israel
| | - Julia Sheviryov
- Porter School of Environment & Earth Sciences, Tel Aviv University. Tel Aviv-Yafo, Israel
| | - Boris Rubinsky
- Mechanical Engineering Department, University of California-Berkeley, CA, USA
| | - César A González
- Porter School of Environment & Earth Sciences, Tel Aviv University. Tel Aviv-Yafo, Israel.,Escuela Superior de Medicina-Instituto Politécnico Nacional, Mexico City, Mexico
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31
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Ott A, Martin TJ, Acharya K, Lyon DY, Robinson N, Rowles B, Snape JR, Still I, Whale GF, Albright VC, Bäverbäck P, Best N, Commander R, Eickhoff C, Finn S, Hidding B, Maischak H, Sowders KA, Taruki M, Walton HE, Wennberg AC, Davenport RJ. Multi-laboratory Validation of a New Marine Biodegradation Screening Test for Chemical Persistence Assessment. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:4210-4220. [PMID: 32162906 DOI: 10.1021/acs.est.9b07710] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Current biodegradation screening tests are not specifically designed for persistence assessment of chemicals, often show high inter- and intra-test variability, and often give false negative biodegradation results. Based on previous studies and recommendations, an international ring test involving 13 laboratories validated a new test method for marine biodegradation with a focus on improving the reliability of screening to determine the environmental degradation potential of chemicals. The new method incorporated increased bacterial cell concentrations to better represent the microbial diversity; a chemical is likely to be exposed in the sampled environments and ran beyond 60 days, which is the half-life threshold for chemical persistence in the marine environment. The new test provided a more reliable and less variable characterization of the biodegradation behavior of five reference chemicals (sodium benzoate, triethanolamine, 4-nitrophenol, anionic polyacrylamide, and pentachlorophenol), with respect to REACH and OSPAR persistence thresholds, than the current OECD 306 test. The proposed new method provides a cost-effective screening test for non-persistence that could streamline chemical regulation and reduce the cost and animal welfare implications of further higher tier testing.
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Affiliation(s)
- Amelie Ott
- School of Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - Timothy J Martin
- School of Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - Kishor Acharya
- School of Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - Delina Y Lyon
- Shell Oil Company, 150 N. Dairy Ashford Rd., Houston, Texas 77079, United States
| | - Nik Robinson
- European Oilfield Specialty Chemicals Association (EOSCA), Aberdeen AB11 6YQ, United Kingdom
| | - Bob Rowles
- Centre for Environment, Fisheries and Aquaculture Science (Cefas), Pakefield Road, Lowestoft NR33 0HT, United Kingdom
| | - Jason R Snape
- School of Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
- AstraZeneca Global Environment, Mereside, Alderley Park, Macclesfield, Cheshire, SK10 4TF, United Kingdom
- School of Life Sciences, University of Warwick, Gibbet Hill Campus, Coventry CV4 7AL, United Kingdom
| | - Ian Still
- European Oilfield Specialty Chemicals Association (EOSCA), Aberdeen AB11 6YQ, United Kingdom
| | - Graham F Whale
- Risk Science Team, Shell International Ltd., 4 York Road, London SE1 7NA, United Kingdom
| | - Vurtice C Albright
- Toxicology & Environmental Research & Consulting, The Dow Chemical Company, Midland, Michigan 48674, United States
| | - Petra Bäverbäck
- Schlumberger, Sandslikroken 140, Sandsli, Bergen 5254, Norway
| | - Nicola Best
- Covance CRS Research Limited, Shardlow Business Park, London Road, Derby DE72 2GD, United Kingdom
| | - Ruth Commander
- Scymaris Ltd., Brixham Laboratory, Brixham TQ5 8BA, United Kingdom
| | - Curtis Eickhoff
- Nautilus Environmental Company, Inc., Burnaby, BC V5A 4N7, Canada
| | - Sarah Finn
- National Oilwell Varco (NOV), Flotta, Stromness, Orkney, KW16 3NP, United Kingdom
| | - Björn Hidding
- BASF SE, Carl-Bosch-Straße 38, Ludwigshafen am Rhein 67056, Germany
| | - Heiko Maischak
- Noack Laboratorien GmbH, Käthe-Paulus-Straße 1, Sarstedt, Hildesheim 31157, Germany
| | - Katherine A Sowders
- Baker Hughes - Environmental Services Group, 369 Marshall Ave., Webster Groves, Missouri 63119, United States
| | - Masanori Taruki
- Chemicals Evaluation and Research Institute, Japan, Kurume (CERI Kurume), 3-2-7 Miyanojin, Kurume-shi, Fukuoka 839-0801, Japan
| | - Helen E Walton
- Centre for Environment, Fisheries and Aquaculture Science (Cefas), Pakefield Road, Lowestoft NR33 0HT, United Kingdom
| | | | - Russell J Davenport
- School of Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
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32
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Favere J, Buysschaert B, Boon N, De Gusseme B. Online microbial fingerprinting for quality management of drinking water: Full-scale event detection. WATER RESEARCH 2020; 170:115353. [PMID: 31881501 DOI: 10.1016/j.watres.2019.115353] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 11/08/2019] [Accepted: 11/27/2019] [Indexed: 06/10/2023]
Abstract
Microbial regrowth during drinking water distribution can result in a variety of problems such as a deviating taste and odor, and may even pose a risk to public health. Frequent monitoring is essential to anticipate events of biological instability, and relevant microbial parameters for operational control of biostability of drinking water should be developed. Here, online flow cytometry and derived biological metrics were used to assess the biological stability of a full-scale drinking water tower during normal and disturbed flow regime. Pronounced operational events, such as switching from drinking water source, and seasonal changes, were detected in the total cell counts, and regrowth was observed despite the short hydraulic residence time of 6-8 h. Based on the flow cytometric fingerprints, the Bray-Curtis dissimilarity was calculated and was developed as unambiguous parameter to indicate or warn for changing microbial drinking water quality during operational events. In the studied water tower, drastic microbial water quality changes were reflected in the Bray-Curtis dissimilarity, which demonstrates its use as an indicator to follow-up and detect microbial quality changes in practice. Hence, the Bray-Curtis dissimilarity can be used in an online setup as a straightforward parameter during full-scale operation of drinking water distribution, and combined with the cell concentration, it serves as an early-warning system for biological instability.
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Affiliation(s)
- Jorien Favere
- Center for Microbial Ecology and Technology (CMET), Department of Biochemical and Microbial Technology, Ghent University, Coupure Links 653, B-9000, Gent, Belgium
| | | | - Nico Boon
- Center for Microbial Ecology and Technology (CMET), Department of Biochemical and Microbial Technology, Ghent University, Coupure Links 653, B-9000, Gent, Belgium
| | - Bart De Gusseme
- Center for Microbial Ecology and Technology (CMET), Department of Biochemical and Microbial Technology, Ghent University, Coupure Links 653, B-9000, Gent, Belgium; FARYS, TMVW, Stropstraat 1, B-9000, Gent, Belgium.
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33
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Coggins LX, Larma I, Hinchliffe A, Props R, Ghadouani A. Flow cytometry for rapid characterisation of microbial community dynamics in waste stabilisation ponds. WATER RESEARCH 2020; 169:115243. [PMID: 31704461 DOI: 10.1016/j.watres.2019.115243] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 10/11/2019] [Accepted: 10/26/2019] [Indexed: 06/10/2023]
Abstract
Algal and bacterial communities play a major role in the treatment performance and efficiency of waste stabilisation ponds (WSPs); however, the study of these WSP microbial communities has been challenging. Flow cytometry (FCM) has been used widely as a rapid, culture-independent method of characterising algae and/or bacteria in a range of freshwater and marine environments, and in conventional wastewater treatment processes, but its application to WSP wastewater has been underexplored. In this study, a method for the characterisation of both algal and bacterial microbial populations in WSP wastewater is presented and standardised, using cultures and field samples. We show that SYTO 16 dye is more effective than SYBR Green I for the concurrent detection of both algae and bacteria in samples. Through gating and phenotypic diversity analysis, the FCM results show both spatial and temporal shifts in pond microbial communities. The ability to rapidly determine the spatiotemporal shifts in pond populations is not only important for the improvement of pond operation and monitoring strategies, but also for the planning and management. Flow cytometry has the potential to become a diagnostic tool for ponds to assess treatment performance and determine the most optimal operating conditions.
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Affiliation(s)
- Liah X Coggins
- Department of of Civil, Environmental and Mining Engineering, The University of Western Australia, 35 Stirling Highway, M051, Crawley, 6009, Western Australia, Australia.
| | - Irma Larma
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, 35 Stirling Highway, M519, Crawley, 6009, Western Australia, Australia.
| | - Amy Hinchliffe
- Department of of Civil, Environmental and Mining Engineering, The University of Western Australia, 35 Stirling Highway, M051, Crawley, 6009, Western Australia, Australia.
| | - Ruben Props
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, B-9000, Gent, Belgium.
| | - Anas Ghadouani
- Department of of Civil, Environmental and Mining Engineering, The University of Western Australia, 35 Stirling Highway, M051, Crawley, 6009, Western Australia, Australia.
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Kumar V, Roy S, Baruah K, Van Haver D, Impens F, Bossier P. Environmental conditions steer phenotypic switching in acute hepatopancreatic necrosis disease-causing Vibrio parahaemolyticus, affecting PirA VP /PirB VP toxins production. Environ Microbiol 2020; 22:4212-4230. [PMID: 31867836 DOI: 10.1111/1462-2920.14903] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 12/12/2019] [Accepted: 12/18/2019] [Indexed: 12/11/2022]
Abstract
Bacteria in nature are widely exposed to differential fluid shears which are often a trigger for phenotypic switches. The latter mediates transcriptional and translation remodelling of cellular metabolism impacting among others virulence, antimicrobial resistance and stress resistance. In this study, we evaluated the role of fluid shear on phenotypic switch in an acute hepatopancreatic necrosis disease (AHPND)-causing Vibrio parahaemolyticus M0904 strain under both in vitro and in vivo conditions. The results showed that V. parahaemolyticus M0904 grown at lower shaking speed (110 rpm constant agitation, M0904/110), causing low fluid shear, develop cellular aggregates or floccules. These cells increased levan production (as verified by concanavalin binding) and developed differentially stained colonies on Congo red agar plates and resistance to antibiotics. In addition, the phenotypic switch causes a major shift in the protein secretome. At 120 rpm (M0904/120), PirAVP /PirBVP toxins are mainly produced, while at 110 rpm PirAVP /PirBVP toxins production is stopped and an alkaline phosphatase (ALP) PhoX becomes the dominant protein in the protein secretome. These observations are matched with a very strong reduction in virulence of M0904/110 towards two crustacean larvae, namely, Artemia and Macrobrachium. Taken together, our study provides substantial evidence for the existence of two phenotypic forms in AHPND V. parahaemolyticus strain displaying differential phenotypes. Moreover, as aerators and pumping devices are frequently used in shrimp aquaculture facilities, they can inflict fluid shear to the standing microbial agents. Hence, our study could provide a basis to understand the behaviour of AHPND-causing V. parahaemolyticus in aquaculture settings and open the possibility to monitor and control AHPND by steering phenotypes.
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Affiliation(s)
- Vikash Kumar
- Laboratory of Aquaculture & Artemia Reference Center, Faculty of Bioscience Engineering, Department of Animal Sciences and Aquatic Ecology, Ghent University, 9000, Ghent, Belgium.,ICAR - Central Inland Fisheries Research Institute (CIFRI), Barrackpore, 700120, India
| | - Suvra Roy
- Laboratory of Aquaculture & Artemia Reference Center, Faculty of Bioscience Engineering, Department of Animal Sciences and Aquatic Ecology, Ghent University, 9000, Ghent, Belgium.,ICAR - Central Inland Fisheries Research Institute (CIFRI), Barrackpore, 700120, India
| | - Kartik Baruah
- Laboratory of Aquaculture & Artemia Reference Center, Faculty of Bioscience Engineering, Department of Animal Sciences and Aquatic Ecology, Ghent University, 9000, Ghent, Belgium.,Department of Animal Nutrition and Management, Faculty of Veterinary Medicine and Animal Sciences, Swedish University of Agricultural Sciences, Uppsala, 75007, Sweden
| | - Delphi Van Haver
- VIB-UGent Center for Medical Biotechnology, B-9000, Ghent, Belgium.,Department of Biomolecular Medicine, Ghent University, B-9000, Ghent, Belgium.,VIB Proteomics Core, B-9000, Ghent, Belgium
| | - Francis Impens
- VIB-UGent Center for Medical Biotechnology, B-9000, Ghent, Belgium.,Department of Biomolecular Medicine, Ghent University, B-9000, Ghent, Belgium.,VIB Proteomics Core, B-9000, Ghent, Belgium
| | - Peter Bossier
- Laboratory of Aquaculture & Artemia Reference Center, Faculty of Bioscience Engineering, Department of Animal Sciences and Aquatic Ecology, Ghent University, 9000, Ghent, Belgium
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Haberkorn I, Buchmann L, Hiestand M, Mathys A. Continuous nanosecond pulsed electric field treatments foster the upstream performance of Chlorella vulgaris-based biorefinery concepts. BIORESOURCE TECHNOLOGY 2019; 293:122029. [PMID: 31473378 DOI: 10.1016/j.biortech.2019.122029] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Revised: 08/14/2019] [Accepted: 08/16/2019] [Indexed: 06/10/2023]
Abstract
Nanosecond pulsed electric field treatment (nsPEF) is an innovative, technology-driven, and resource-efficient approach to foster the upstream performance of microalgae-based biorefinery concepts to transform microalgae into economic more viable raw materials for the biobased industry. A processing window applying three treatments of 100 ns, 5 Hz, and 10 kV cm-1 to industrially relevant phototrophic Chlorella vulgaris in the early exponential growth phase significantly increased biomass yields by up to 17.53 ± 10.46% (p = 3.18 × 10-5). Treatments had limited effects on the carbon and pigment contents, but the protein content was decreased. The longest possible pulse width (100 ns) resulted in the highest biomass yield indicating underlying working mechanisms of enhanced cell proliferation based on intracellular and plasma membrane-related effects. The applicability to eukaryotes and prokaryotes, such as C. vulgaris and cyanobacteria highlights the possible impacts of nsPEF across multiple domains of the biobased industry relying on single-cell-based value-chains.
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Affiliation(s)
- Iris Haberkorn
- ETH Zurich, Department of Health Sciences and Technology, Institute of Food, Nutrition and Health, Sustainable Food Processing Laboratory, Schmelzbergstrasse 9, Zurich 8092, Switzerland
| | - Leandro Buchmann
- ETH Zurich, Department of Health Sciences and Technology, Institute of Food, Nutrition and Health, Sustainable Food Processing Laboratory, Schmelzbergstrasse 9, Zurich 8092, Switzerland
| | - Michèle Hiestand
- ETH Zurich, Department of Health Sciences and Technology, Institute of Food, Nutrition and Health, Sustainable Food Processing Laboratory, Schmelzbergstrasse 9, Zurich 8092, Switzerland
| | - Alexander Mathys
- ETH Zurich, Department of Health Sciences and Technology, Institute of Food, Nutrition and Health, Sustainable Food Processing Laboratory, Schmelzbergstrasse 9, Zurich 8092, Switzerland.
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Jiang X, Liu S, Yang M, Rasooly A. Amperometric genosensor for culture independent bacterial count. SENSORS AND ACTUATORS. B, CHEMICAL 2019; 299:10.1016/j.snb.2019.126944. [PMID: 32009738 PMCID: PMC6993526 DOI: 10.1016/j.snb.2019.126944] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Bacterial plate count for general assessment of water quality requires lengthy bacterial culturing. We report here a new DNA induced current genosensor for culture independent total bacteria determination. Since the amount of bacterial DNA is correlated to the number of bacteria, the genosensor measures the amount of bacterial DNA to determine bacterial count. The approach relies on bacteria lysis to release DNA which can react with molybdate to form redox molybdophosphate and measured electrochemically. Analysis of E. coli and S. aureus demonstrated that the DNA generated current is highly correlated with the level of bacteria lysis which was confirmed by spectrometric measurement. Culture independent measurement of S. aureus bacterial load suggests limit of detection is 21.9 CFU/mL, with linear range from 3×102 to 3×107 CFU/mL and correlation coefficient of 0.992. For E. coli analysis, the detection limit is 25.1 CFU/mL with the same linear range. The use of electrochemical microbial DNA quantitation for culture independent bacterial count is a new approach, the genosensor measurement is rapid (within 1 h) and has potential use for analysis of broad-spectrum bacteria for various applications.
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Affiliation(s)
- Xingxing Jiang
- Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, College of Chemistry and Chemical Engineering, Central South University, Changsha, China, 410083
| | - Shuping Liu
- Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, College of Chemistry and Chemical Engineering, Central South University, Changsha, China, 410083
| | - Minghui Yang
- Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, College of Chemistry and Chemical Engineering, Central South University, Changsha, China, 410083
- Corresponding Authors: (M. Yang) (A. Rasooly)
| | - Avraham Rasooly
- National Cancer Institute, National Institutes of Health, Rockville, Maryland 20850, United States
- Corresponding Authors: (M. Yang) (A. Rasooly)
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37
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Bonadonna L, Briancesco R, La Rosa G. Innovative analytical methods for monitoring microbiological and virological water quality. Microchem J 2019. [DOI: 10.1016/j.microc.2019.104160] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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38
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Fillinger L, Hug K, Trimbach AM, Wang H, Kellermann C, Meyer A, Bendinger B, Griebler C. The D-A-(C) index: A practical approach towards the microbiological-ecological monitoring of groundwater ecosystems. WATER RESEARCH 2019; 163:114902. [PMID: 31362215 DOI: 10.1016/j.watres.2019.114902] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 07/17/2019] [Accepted: 07/22/2019] [Indexed: 06/10/2023]
Abstract
Groundwater is not only a vital resource, but also one of the largest terrestrial aquatic ecosystems on Earth. However, to date, ecological criteria are often not considered in routine groundwater monitoring, mainly because of the lack of suitable ecological assessment tools. Prokaryotic microorganisms are ubiquitous in groundwater ecosystems even under the harshest conditions, making them ideal bioindicators for ecological monitoring. We have developed a simple, inexpensive approach that enables ecological groundwater monitoring based on three microbiological parameters that can be easily integrated into existing routine monitoring practices: prokaryotic cell density (D) measured by flow cytometry; activity (A) measured as prokaryotic intracellular ATP concentrations using a simple cell-lysis-luminescence assay; and, as an optional parameter, the bioavailable carbon (C) measured as the concentration of assimilable organic carbon in a simple batch growth assay. We analyzed data for three case studies of different disturbances representing some of the main threats to groundwater ecosystems, i.e. organic contamination with hydrocarbons, surface water intrusion, and agricultural land use. For all three disturbances, disturbed samples could be reliably distinguished from undisturbed samples based on a single index value obtained from multivariate outlier analyses of the microbial variables. We could show that this multivariate approach allowed for a significantly more sensitive and reliable detection of disturbed samples compared to separate univariate outlier analyses of the measured variables. Furthermore, a comparison of non-contaminated aquifers from nine different regions across Germany revealed distinct multivariate signatures along the three microbial variables, which should be considered when applying our approach in practice. In essence, our approach offers a practical tool for the detection of disturbances of groundwater ecosystems based on microbial parameters which can be seamlessly extended in the future by additional parameters for higher sensitivity as well as flexibility.
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Affiliation(s)
- Lucas Fillinger
- Helmholtz Zentrum München, Institute of Groundwater Ecology, Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - Katrin Hug
- Helmholtz Zentrum München, Institute of Groundwater Ecology, Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - Anne Madeleine Trimbach
- Hamburg University of Technology, DVGW Research Centre TUHH, Am Schwarzenberg-Campus 3, 21073, Hamburg, Germany
| | - He Wang
- Helmholtz Zentrum München, Institute of Groundwater Ecology, Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - Claudia Kellermann
- Helmholtz Zentrum München, Institute of Groundwater Ecology, Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - Astrid Meyer
- Helmholtz Zentrum München, Institute of Groundwater Ecology, Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - Bernd Bendinger
- Hamburg University of Technology, DVGW Research Centre TUHH, Am Schwarzenberg-Campus 3, 21073, Hamburg, Germany
| | - Christian Griebler
- Helmholtz Zentrum München, Institute of Groundwater Ecology, Ingolstädter Landstraße 1, 85764, Neuherberg, Germany.
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Cheswick R, Cartmell E, Lee S, Upton A, Weir P, Moore G, Nocker A, Jefferson B, Jarvis P. Comparing flow cytometry with culture-based methods for microbial monitoring and as a diagnostic tool for assessing drinking water treatment processes. ENVIRONMENT INTERNATIONAL 2019; 130:104893. [PMID: 31226555 DOI: 10.1016/j.envint.2019.06.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 05/31/2019] [Accepted: 06/02/2019] [Indexed: 06/09/2023]
Abstract
Flow cytometry (FCM) and the ability to measure both total and intact cell populations through DNA staining methodologies has rapidly gained attention and consideration across the water sector in the past decade. In this study, water quality monitoring was undertaken over three years across 213 drinking water treatment works (WTW) in the Scottish Water region (Total n = 39,340). Samples subject to routine regulatory microbial analysis using culture-based methods were also analysed using FCM. In addition to final treated water, the bacterial content in raw water was measured over a one-year period. Three WTW were studied in further detail using on-site inter-stage sampling and analysis with FCM. It was demonstrated that there was no clear link between FCM data and the coliform samples taken for regulatory monitoring. The disinfectant Ct value (Ct = mg·min/L) was the driving factor in determining final water cell viability and the proportion of intact cells (intact/total cells) and the frequency of coliform detections in the water leaving the WTW. However, the free chlorine residual, without consideration of treatment time, was shown to have little impact on coliform detections or cell counts. Amongst the three treatment trains monitored in detail, the membrane filtration WTW showed the greatest log removal and robustness in terms of final water intact cell counts. Flow cytometry was shown to provide insights into the bacteriological quality of water that adds significant value over and above that provided by traditional bacterial monitoring.
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Affiliation(s)
- Ryan Cheswick
- Cranfield Water Science Institute, School of Water, Energy and Environment, Cranfield MK43 0AL, UK; Scottish Water, 6 Castle Drive, Carnegie Campus, Dunfermline KY11 8GG, UK
| | - Elise Cartmell
- Scottish Water, 6 Castle Drive, Carnegie Campus, Dunfermline KY11 8GG, UK
| | - Susan Lee
- Scottish Water, 6 Castle Drive, Carnegie Campus, Dunfermline KY11 8GG, UK
| | - Andrew Upton
- Cranfield Water Science Institute, School of Water, Energy and Environment, Cranfield MK43 0AL, UK; Scottish Water, 6 Castle Drive, Carnegie Campus, Dunfermline KY11 8GG, UK
| | - Paul Weir
- Scottish Water, 6 Castle Drive, Carnegie Campus, Dunfermline KY11 8GG, UK
| | - Graeme Moore
- Scottish Water, 6 Castle Drive, Carnegie Campus, Dunfermline KY11 8GG, UK
| | - Andreas Nocker
- IWW Water Centre, Morizstraße 26, 45476 Mülheim an der Ruhr, Germany
| | - Bruce Jefferson
- Cranfield Water Science Institute, School of Water, Energy and Environment, Cranfield MK43 0AL, UK
| | - Peter Jarvis
- Cranfield Water Science Institute, School of Water, Energy and Environment, Cranfield MK43 0AL, UK.
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40
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Quantification and isolation of Bacillus subtilis spores using cell sorting and automated gating. PLoS One 2019; 14:e0219892. [PMID: 31356641 PMCID: PMC6663000 DOI: 10.1371/journal.pone.0219892] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 07/04/2019] [Indexed: 01/22/2023] Open
Abstract
The Gram-positive bacterium Bacillus subtilis is able to form endospores which have a variety of biotechnological applications. Due to this ability, B. subtilis is as well a model organism for cellular differentiation processes. Sporulating cultures of B. subtilis form sub-populations which include vegetative cells, sporulating cells and spores. In order to readily and rapidly quantify spore formation we employed flow cytometric and fluorescence activated cell sorting techniques in combination with nucleic acid fluorescent staining in order to investigate the distribution of sporulating cultures on a single cell level. Automated gating procedures using Gaussian mixture modeling (GMM) were employed to avoid subjective gating and allow for the simultaneous measurement of controls. We utilized the presented method for monitoring sporulation over time in germination deficient strains harboring different genome modifications. A decrease in the sporulation efficiency of strain Bs02018, utilized for the display of sfGFP on the spores surface was observed. On the contrary, a double knock-out mutant of the phosphatase gene encoding Spo0E and of the spore killing factor SkfA (Bs02025) exhibited the highest sporulation efficiency, as within 24 h of cultivation in sporulation medium, cultures of BS02025 already consisted of 80% spores as opposed to 18% for the control strain. We confirmed the identity of the different subpopulations formed during sporulation by employing sorting and microscopy.
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41
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Deng L, Fiskal A, Han X, Dubois N, Bernasconi SM, Lever MA. Improving the Accuracy of Flow Cytometric Quantification of Microbial Populations in Sediments: Importance of Cell Staining Procedures. Front Microbiol 2019; 10:720. [PMID: 31024498 PMCID: PMC6465615 DOI: 10.3389/fmicb.2019.00720] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 03/21/2019] [Indexed: 12/12/2022] Open
Abstract
The accuracy of flow cytometric (FCM) quantifications of microbial populations in sediments varies with FCM settings, cell extraction and staining protocols, as well as sample types. In the present study, we improve the accuracy of FCM for enumerating microorganisms inhabiting diverse lake and marine sediment types based on extensive tests with FCM settings, extraction buffer chemical compositions, cell separation methods, and staining procedures. Tests on the FCM settings, (e.g., acquisition time, rates of events) and salinity of extraction solutions show minor impacts on FCM enumerations and yields of cell extraction, respectively. Existing methods involving hydrofluoric acid (HF) treatment to release sediment-attached cells into solution prove effective on both marine and freshwater samples. Yet, different staining techniques (direct staining of cell extracts, staining of membrane-filtered cell extracts) produce clear differences in cell number estimates. We demonstrate that, while labor-intensive membrane-staining generates high cell staining efficiency and accurate cell counts that are consistent across FCM and epifluorescence microscopy-based (EFM) quantification methods, accurate cell counts determined by more time- and labor-efficient direct staining require consideration of dye concentration, sample dilution, and lithology. Yet, good agreement between the two staining methods can be achieved through sample-specific adjustments of dye concentrations and sample dilutions during direct staining. We thus present a complete protocol for FCM-based cell quantification, that includes all steps from the initial sample fixation to the final enumeration, with recommendations for buffer compositions, direct and membrane-based staining procedures, and the final FCM assay. This protocol is versatile, accurate, and reliable, as is evident from good agreement with cell quantifications by EFM and quantitative polymerase chain reaction (qPCR) of 16S rRNA genes across a wide range of sedimentary sample types.
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Affiliation(s)
- Longhui Deng
- Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, Zurich, Switzerland
| | - Annika Fiskal
- Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, Zurich, Switzerland
| | - Xingguo Han
- Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, Zurich, Switzerland
| | - Nathalie Dubois
- Surface Waters Research-Management, Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland.,Department of Earth Sciences, ETH Zürich, Zurich, Switzerland
| | | | - Mark Alexander Lever
- Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, Zurich, Switzerland
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42
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Very rapid flow cytometric assessment of antimicrobial susceptibility during the apparent lag phase of microbial (re)growth. Microbiology (Reading) 2019; 165:439-454. [DOI: 10.1099/mic.0.000777] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
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Safford HR, Bischel HN. Flow cytometry applications in water treatment, distribution, and reuse: A review. WATER RESEARCH 2019; 151:110-133. [PMID: 30594081 DOI: 10.1016/j.watres.2018.12.016] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 11/30/2018] [Accepted: 12/01/2018] [Indexed: 06/09/2023]
Abstract
Ensuring safe and effective water treatment, distribution, and reuse requires robust methods for characterizing and monitoring waterborne microbes. Methods widely used today can be limited by low sensitivity, high labor and time requirements, susceptibility to interference from inhibitory compounds, and difficulties in distinguishing between viable and non-viable cells. Flow cytometry (FCM) has recently gained attention as an alternative approach that can overcome many of these challenges. This article critically and systematically reviews for the first time recent literature on applications of FCM in water treatment, distribution, and reuse. In the review, we identify and examine nearly 300 studies published from 2000 to 2018 that illustrate the benefits and challenges of using FCM for assessing source-water quality and impacts of treatment-plant discharge on receiving waters, wastewater treatment, drinking water treatment, and drinking water distribution. We then discuss options for combining FCM with other indicators of water quality and address several topics that cut across nearly all applications reviewed. Finally, we identify priority areas in which more work is needed to realize the full potential of this approach. These include optimizing protocols for FCM-based analysis of waterborne viruses, optimizing protocols for specifically detecting target pathogens, automating sample handling and preparation to enable real-time FCM, developing computational tools to assist data analysis, and improving standards for instrumentation, methods, and reporting requirements. We conclude that while more work is needed to realize the full potential of FCM in water treatment, distribution, and reuse, substantial progress has been made over the past two decades. There is now a sufficiently large body of research documenting successful applications of FCM that the approach could reasonably and realistically see widespread adoption as a routine method for water quality assessment.
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Affiliation(s)
- Hannah R Safford
- Department of Civil and Environmental Engineering, University of California Davis, 2001 Ghausi Hall, 480 Bainer Hall Drive, 95616, Davis, CA, United States
| | - Heather N Bischel
- Department of Civil and Environmental Engineering, University of California Davis, 2001 Ghausi Hall, 480 Bainer Hall Drive, 95616, Davis, CA, United States.
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44
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Ersoy ZG, Dinc O, Cinar B, Gedik ST, Dimoglo A. Comparative evaluation of disinfection mechanism of sodium hypochlorite, chlorine dioxide and electroactivated water on Enterococcus faecalis. Lebensm Wiss Technol 2019. [DOI: 10.1016/j.lwt.2018.12.041] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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45
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Girgin Ersoy Z, Barisci S, Dinc O. Mechanisms of the Escherichia coli and Enterococcus faecalis inactivation by ozone. Lebensm Wiss Technol 2019. [DOI: 10.1016/j.lwt.2018.10.095] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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46
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Props R, Rubbens P, Besmer M, Buysschaert B, Sigrist J, Weilenmann H, Waegeman W, Boon N, Hammes F. Detection of microbial disturbances in a drinking water microbial community through continuous acquisition and advanced analysis of flow cytometry data. WATER RESEARCH 2018; 145:73-82. [PMID: 30121434 DOI: 10.1016/j.watres.2018.08.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Revised: 07/26/2018] [Accepted: 08/06/2018] [Indexed: 06/08/2023]
Abstract
Detecting disturbances in microbial communities is an important aspect of managing natural and engineered microbial communities. Here, we implemented a custom-built continuous staining device in combination with real-time flow cytometry (RT-FCM) data acquisition, which, combined with advanced FCM fingerprinting methods, presents a powerful new approach to track and quantify disturbances in aquatic microbial communities. Through this new approach we were able to resolve various natural community and single-species microbial contaminations in a flow-through drinking water reactor. Next to conventional FCM metrics, we applied metrics from a recently developed fingerprinting technique in order to gain additional insight into the microbial dynamics during these contamination events. Importantly, we found that multiple community FCM metrics based on different statistical approaches were required to fully characterize all contaminations. Furthermore we found that for accurate cell concentration measurements and accurate inference from the FCM metrics (coefficient of variation ≤ 5%), at least 1000 cells should be measured, which makes the achievable temporal resolution a function of the prevalent bacterial concentration in the system-of-interest. The integrated RT-FCM acquisition and analysis approach presented herein provides a considerable improvement in the temporal resolution by which microbial disturbances can be observed and simultaneously provides a multi-faceted toolset to characterize such disturbances.
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Affiliation(s)
- Ruben Props
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, B-9000, Gent, Belgium
| | - Peter Rubbens
- KERMIT, Department of Data Analysis and Mathematical Modelling, Ghent University, Coupure Links 653, B-9000, Ghent, Belgium
| | - Michael Besmer
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600, Duebendorf, Switzerland; Department of Environmental Systems Science, Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, Zürich, Switzerland
| | - Benjamin Buysschaert
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, B-9000, Gent, Belgium
| | - Jurg Sigrist
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600, Duebendorf, Switzerland
| | - Hansueli Weilenmann
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600, Duebendorf, Switzerland
| | - Willem Waegeman
- KERMIT, Department of Data Analysis and Mathematical Modelling, Ghent University, Coupure Links 653, B-9000, Ghent, Belgium
| | - Nico Boon
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, B-9000, Gent, Belgium
| | - Frederik Hammes
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600, Duebendorf, Switzerland.
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Park JW, Lee YJ, Meyer AS, Douterelo I, Maeng SK. Bacterial growth through microfiltration membranes and NOM characteristics in an MF-RO integrated membrane system: Lab-scale and full-scale studies. WATER RESEARCH 2018; 144:36-45. [PMID: 30014977 DOI: 10.1016/j.watres.2018.07.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Revised: 07/07/2018] [Accepted: 07/10/2018] [Indexed: 06/08/2023]
Abstract
Biofilm formation on membrane surfaces causes many operational problems such as a decrease in permeate flux and an increase in hydraulic resistance. In this study, the ability of bacteria to pass through microfiltration (MF) membranes and the growth potential of microfilterable bacteria were investigated in order to understand biofouling in MF-reverse osmosis (RO) integrated membrane systems. Growth of microfilterable bacteria in MF permeate was observed, indicating that not all MF membranes can guarantee the total rejection of bacteria. Changes in natural organic matter (NOM) characteristics and growth potential of bacteria during the treatment process are important factors in the occurrence of biofilm development in water treatment systems. Analysis of protein-like and humic-like substances in NOM of two successive RO stages revealed an increase in the concentrations of both biopolymers and humic substances of RO concentrates. Unexpectedly, the use of antiscalants was seen to enhance the growth of bacteria in the RO feed water in this study. Bacterial 16s rRNA pyrosequencing revealed that passing source water through the MF membranes dramatically changed bacterial community structure. The bacterial communities that passed through the MF steps primarily belonged to the family Comamonadaceae. However, several bacteria groups including Flavobacteriaceae, Sphingobacteriaceae and Sphingomonadaceae selectively composed the biofilm community formed on the RO membranes. Thus, understanding the selectivity and filterability of MF towards microorganisms involved in biofouling on RO membrane surfaces is crucial for the improvement of membrane-related operational processes.
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Affiliation(s)
- Ji Won Park
- Department of Civil and Environmental Engineering, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul, 05006, Republic of Korea
| | - Young Joo Lee
- K-water Convergence Institute, 125 Yuseong-daero 1689 beon-gil, Yuseong-gu, Deajeon, 34045, Republic of Korea
| | - Anne S Meyer
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Isabel Douterelo
- Pennine Water Group, Department of Civil and Structural Engineering, The University of Sheffield, Sheffield, United Kingdom
| | - Sung Kyu Maeng
- Department of Civil and Environmental Engineering, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul, 05006, Republic of Korea.
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48
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Bacteria Detection and Differentiation Using Impedance Flow Cytometry. SENSORS 2018; 18:s18103496. [PMID: 30336557 PMCID: PMC6210208 DOI: 10.3390/s18103496] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 10/11/2018] [Accepted: 10/15/2018] [Indexed: 12/01/2022]
Abstract
Monitoring of bacteria concentrations is of great importance in drinking water management. Continuous real-time monitoring enables better microbiological control of the water and helps prevent contaminated water from reaching the households. We have developed a microfluidic sensor with the potential to accurately assess bacteria levels in drinking water in real-time. Multi frequency electrical impedance spectroscopy is used to monitor a liquid sample, while it is continuously passed through the sensor. We investigate three aspects of this sensor: First we show that the sensor is able to differentiate Escherichia coli (Gram-negative) bacteria from solid particles (polystyrene beads) based on an electrical response in the high frequency phase and individually enumerate the two samples. Next, we demonstrate the sensor’s ability to measure the bacteria concentration by comparing the results to those obtained by the traditional CFU counting method. Last, we show the sensor’s potential to distinguish between different bacteria types by detecting different signatures for S. aureus and E. coli mixed in the same sample. Our investigations show that the sensor has the potential to be extremely effective at detecting sudden bacterial contaminations found in drinking water, and eventually also identify them.
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49
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Helmi K, David F, Di Martino P, Jaffrezic MP, Ingrand V. Assessment of flow cytometry for microbial water quality monitoring in cooling tower water and oxidizing biocide treatment efficiency. J Microbiol Methods 2018; 152:201-209. [PMID: 29958908 DOI: 10.1016/j.mimet.2018.06.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 06/25/2018] [Accepted: 06/25/2018] [Indexed: 10/28/2022]
Abstract
The control of Legionella proliferation in cooling tower water circuits requires regular monitoring of water contamination and effective disinfection procedures. In this study, flow cytometry was assessed to monitor water contamination and disinfection treatment efficiency on bacterial cells regarding nucleic acid injury (SYBR® Green II), cell integrity (SYBR® Green II and propidium iodide) and metabolism activity (ChemChrome V6). A total of 27 cooling tower water samples were analyzed in order to assess water contamination levels regarding viable populations: standard culture, ATP measurement and flow cytometry methods were compared. Flow cytometry and plate counts methods showed a significant correlation for changes in concentrations despite a 1 to 2-log difference regarding absolute quantification. Concerning intracellular activity, the use of two different flow cytometers (FACSCanto™ II and Accuri™ C6) showed no statistical difference while a difference was observed between flow cytometry and usual methods (culture and ATP measurement). The standard culture and flow cytometry methods were also compared for in vitro bacteria inactivation measurements in the presence of 3 different types of oxidizing biocides commonly used for cooling tower disinfection. Reductions observed ranged between 1 and 2 log depending on (1) the detection method, (2) the bacterial population origin and/or (3) the active biocide molecule used. In conclusion, flow cytometry represents an efficient, accurate and fast approach to monitor water contamination and biocide treatment efficiency in cooling towers.
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Affiliation(s)
- Karim Helmi
- Veolia Recherche et Innovation, Chemin de la Digue, 78600 Maisons-Laffitte, France.
| | - Fabienne David
- Veolia Recherche et Innovation, Chemin de la Digue, 78600 Maisons-Laffitte, France
| | - Patrick Di Martino
- Université de Cergy-Pontoise, 5 mail Gay-Lussac, 95031 Cergy-Pontoise cedex, France
| | | | - Valérie Ingrand
- Veolia Recherche et Innovation, Chemin de la Digue, 78600 Maisons-Laffitte, France
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50
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Sorensen JPR, Vivanco A, Ascott MJ, Gooddy DC, Lapworth DJ, Read DS, Rushworth CM, Bucknall J, Herbert K, Karapanos I, Gumm LP, Taylor RG. Online fluorescence spectroscopy for the real-time evaluation of the microbial quality of drinking water. WATER RESEARCH 2018; 137:301-309. [PMID: 29554534 DOI: 10.1016/j.watres.2018.03.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 01/29/2018] [Accepted: 03/01/2018] [Indexed: 05/22/2023]
Abstract
We assessed the utility of online fluorescence spectroscopy for the real-time evaluation of the microbial quality of untreated drinking water. Online fluorimeters were installed on the raw water intake at four groundwater-derived UK public water supplies alongside existing turbidity sensors that are used to forewarn of the presence of microbial contamination in the water industry. The fluorimeters targeted fluorescent dissolved organic matter (DOM) peaks at excitation/emission wavelengths of 280/365 nm (tryptophan-like fluorescence, TLF) and 280/450 nm (humic-like fluorescence, HLF). Discrete samples were collected for Escherichia coli, total bacterial cell counts by flow cytometry, and laboratory-based fluorescence and absorbance. Both TLF and HLF were strongly correlated with E. coli (ρ = 0.71-0.77) and total bacterial cell concentrations (ρ = 0.73-0.76), whereas the correlations between turbidity and E. coli (ρ = 0.48) and total bacterial cell counts (ρ = 0.40) were much weaker. No clear TLF peak was observed at the sites and all apparent TLF was considered to be optical bleed-through from the neighbouring HLF peak. Therefore, a HLF fluorimeter alone would be sufficient to evaluate the microbial water quality at these sources. Fluorescent DOM was also influenced by site operations such as pump start-up and the precipitation of cations on the sensor windows. Online fluorescent DOM sensors are a better indicator of the microbial quality of untreated drinking water than turbidity and they have wide-ranging potential applications within the water industry.
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Affiliation(s)
- J P R Sorensen
- British Geological Survey, Maclean Building, Wallingford, OX10 8BB, UK.
| | - A Vivanco
- British Geological Survey, Maclean Building, Wallingford, OX10 8BB, UK
| | - M J Ascott
- British Geological Survey, Maclean Building, Wallingford, OX10 8BB, UK
| | - D C Gooddy
- British Geological Survey, Maclean Building, Wallingford, OX10 8BB, UK
| | - D J Lapworth
- British Geological Survey, Maclean Building, Wallingford, OX10 8BB, UK
| | - D S Read
- Centre for Ecology & Hydrology, Maclean Building, Wallingford, OX10 8BB, UK
| | - C M Rushworth
- Chelsea Technologies Group, 55 Central Ave, Molesey, West Molesey, KT8 2QZ, UK
| | - J Bucknall
- Portsmouth Water, PO Box 99, West Street, Havant, Hampshire, PO9 1LG, UK
| | - K Herbert
- Wessex Water, Wessex Road, Dorchester, DT1 2NY, UK
| | - I Karapanos
- Affinity Water, Tamblin Way, Hatfield, AL10 9EZ, UK
| | - L P Gumm
- British Geological Survey, Maclean Building, Wallingford, OX10 8BB, UK
| | - R G Taylor
- Department of Geography, University College London, Gower Street, London, WC1E 6BT, UK
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