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Chen YC, Destouches L, Cook A, Fedorec AJH. Synthetic microbial ecology: engineering habitats for modular consortia. J Appl Microbiol 2024; 135:lxae158. [PMID: 38936824 DOI: 10.1093/jambio/lxae158] [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: 04/27/2024] [Revised: 06/13/2024] [Accepted: 06/26/2024] [Indexed: 06/29/2024]
Abstract
Microbiomes, the complex networks of micro-organisms and the molecules through which they interact, play a crucial role in health and ecology. Over at least the past two decades, engineering biology has made significant progress, impacting the bio-based industry, health, and environmental sectors; but has only recently begun to explore the engineering of microbial ecosystems. The creation of synthetic microbial communities presents opportunities to help us understand the dynamics of wild ecosystems, learn how to manipulate and interact with existing microbiomes for therapeutic and other purposes, and to create entirely new microbial communities capable of undertaking tasks for industrial biology. Here, we describe how synthetic ecosystems can be constructed and controlled, focusing on how the available methods and interaction mechanisms facilitate the regulation of community composition and output. While experimental decisions are dictated by intended applications, the vast number of tools available suggests great opportunity for researchers to develop a diverse array of novel microbial ecosystems.
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Affiliation(s)
- Yue Casey Chen
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
| | - Louie Destouches
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
| | - Alice Cook
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
| | - Alex J H Fedorec
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
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2
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Pluym T, Waegenaar F, De Gusseme B, Boon N. Microbial drinking water monitoring now and in the future. Microb Biotechnol 2024; 17:e14532. [PMID: 39051617 PMCID: PMC11270321 DOI: 10.1111/1751-7915.14532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2024] [Accepted: 07/08/2024] [Indexed: 07/27/2024] Open
Abstract
Over time, humanity has addressed microbial water contamination in various ways. Historically, individuals resorted to producing beer to combat the issue. Fast forward to the 19th century, and we witnessed a scientific approach by Robert Koch. His groundbreaking gelatine plating method aimed to identify and quantify bacteria, with a proposed limit of 100 colony-forming units per millilitre (CFU/mL) to avoid Cholera outbreaks. Despite considerable advancements in plating techniques through experimentation with media compositions and growth temperatures, the reliance on a century-old method for water safety remains the state-of-the-art. Even though most countries succeed in producing qualitative water at the end of the production centres, it is difficult to control, and guarantee, the same quality during distribution. Rather than focusing solely on specific sampling points, we propose a holistic examination of the entire water network to ensure comprehensive safety. Current practices leave room for uncertainties, especially given the low concentrations of pathogens. Innovative methods like flow cytometry and flow cytometric fingerprinting offer the ability to detect changes in the microbiome of drinking water. Additionally, molecular techniques and emerging sequencing technologies, such as third-generation sequencing (MinION), mark a significant leap forward, enhancing detection limits and emphasizing the identification of unwanted genes rather than the unwanted bacteria/microorganisms itself. Over the last decades, there has been the realization that the drinking water distribution networks are complex ecosystems that, beside bacteria, comprise of viruses, protozoans and even isopods. Sequencing techniques to find eukaryotic DNA are necessary to monitor the entire microbiome of the drinking water distribution network. Or will artificial intelligence, big data and machine learning prove to be the way to go for (microbial) drinking water monitoring? In essence, it is time to transcend century-old practices and embrace modern technologies to ensure the safety of our drinking water from production to consumption.
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Affiliation(s)
- Thomas Pluym
- Center for Microbial Ecology and Technology (CMET), Department of BiotechnologyGhent UniversityGhentBelgium
- Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE)GhentBelgium
| | - Fien Waegenaar
- Center for Microbial Ecology and Technology (CMET), Department of BiotechnologyGhent UniversityGhentBelgium
- Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE)GhentBelgium
| | - Bart De Gusseme
- Center for Microbial Ecology and Technology (CMET), Department of BiotechnologyGhent UniversityGhentBelgium
- Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE)GhentBelgium
- Farys, Department R&D – Innovation WaterGhentBelgium
| | - Nico Boon
- Center for Microbial Ecology and Technology (CMET), Department of BiotechnologyGhent UniversityGhentBelgium
- Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE)GhentBelgium
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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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Waegenaar F, García-Timermans C, Van Landuyt J, De Gusseme B, Boon N. Impact of operational conditions on drinking water biofilm dynamics and coliform invasion potential. Appl Environ Microbiol 2024; 90:e0004224. [PMID: 38647288 PMCID: PMC11107155 DOI: 10.1128/aem.00042-24] [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: 01/17/2024] [Accepted: 03/27/2024] [Indexed: 04/25/2024] Open
Abstract
Biofilms within drinking water distribution systems serve as a habitat for drinking water microorganisms. However, biofilms can negatively impact drinking water quality by causing water discoloration and deterioration and can be a reservoir for unwanted microorganisms. In this study, we investigated whether indicator organisms for drinking water quality, such as coliforms, can settle in mature drinking water biofilms. Therefore, a biofilm monitor consisting of glass rings was used to grow and sample drinking water biofilms. Two mature drinking water biofilms were characterized by flow cytometry, ATP measurements, confocal laser scanning microscopy, and 16S rRNA sequencing. Biofilms developed under treated chlorinated surface water supply exhibited lower cell densities in comparison with biofilms resulting from treated groundwater. Overall, the phenotypic as well as the genotypic characteristics were significantly different between both biofilms. In addition, the response of the biofilm microbiome and possible biofilm detachment after minor water quality changes were investigated. Limited changes in pH and free chlorine addition, to simulate operational changes that are relevant for practice, were evaluated. It was shown that both biofilms remained resilient. Finally, mature biofilms were prone to invasion of the coliform, Serratia fonticola. After spiking low concentrations (i.e., ±100 cells/100 mL) of the coliform to the corresponding bulk water samples, the coliforms were able to attach and get established within the mature biofilms. These outcomes emphasize the need for continued research on biofilm detachment and its implications for water contamination in distribution networks. IMPORTANCE The revelation that even low concentrations of coliforms can infiltrate into mature drinking water biofilms highlights a potential public health concern. Nowadays, the measurement of coliform bacteria is used as an indicator for fecal contamination and to control the effectiveness of disinfection processes and the cleanliness and integrity of distribution systems. In Flanders (Belgium), 533 out of 18,840 measurements exceeded the established norm for the coliform indicator parameter in 2021; however, the source of microbial contamination is mostly unknown. Here, we showed that mature biofilms, are susceptible to invasion of Serratia fonticola. These findings emphasize the importance of understanding and managing biofilms in drinking water distribution systems, not only for their potential to influence water quality, but also for their role in harboring and potentially disseminating pathogens. Further research into biofilm detachment, long-term responses to operational changes, and pathogen persistence within biofilms is crucial to inform strategies for safeguarding drinking water quality.
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Affiliation(s)
- Fien Waegenaar
- Department of Biotechnology, Center for Microbial Ecology and Technology (CMET), Ghent University, Ghent, Belgium
- Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Ghent, Belgium
| | - Cristina García-Timermans
- Department of Biotechnology, Center for Microbial Ecology and Technology (CMET), Ghent University, Ghent, Belgium
- Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Ghent, Belgium
| | - Josefien Van Landuyt
- Department of Biotechnology, Center for Microbial Ecology and Technology (CMET), Ghent University, Ghent, Belgium
- Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Ghent, Belgium
| | - Bart De Gusseme
- Department of Biotechnology, Center for Microbial Ecology and Technology (CMET), Ghent University, Ghent, Belgium
- Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Ghent, Belgium
- Farys, Department R&D – Innovation Water, Ghent, Belgium
| | - Nico Boon
- Department of Biotechnology, Center for Microbial Ecology and Technology (CMET), Ghent University, Ghent, Belgium
- Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Ghent, Belgium
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Budzinski L, Radbruch A, Chang HD. Single-cell multi-parametric characterization of microbiota by flow cytometry. Methods Cell Biol 2024; 186:91-106. [PMID: 38705607 DOI: 10.1016/bs.mcb.2024.02.023] [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] [Indexed: 05/07/2024]
Abstract
It has become evident, that the microbes colonizing the human body have a great impact on health and disease. Investigations of microbiota currently primarily rely on culturomics, high-throughput sequencing and metaproteomics which have considerably advanced our knowledge regarding the role of the microbiota in our environment and for our health. While single-cell phenotyping of immune cells and other somatic cells by flow cytometry has become widely used, the detailed analysis of bacterial cells such as the human microbiota on the single-cell level, is lagging behind. Here, we outline a protocol for the single-cell characterization of bacterial cells from complex microbiota samples, such as stool, by multi-parametric flow cytometry. Our protocol describes the isotype-specific detection of host-antibody coating of intestinal bacteria ex vivo, which together with quantitative DNA staining and light scatter detection comprise an individual's microbiota fingerprint. Cryoconservation and appropriate staining controls ensure reliable, reproducible data generation and analysis. We have automated the analysis of the multi-dimensional data using a segmentation approach by self-organizing map (SOM) algorithm for downstream comparative analyses. Our protocol can be adapted to integrate further phenotypic markers and uses the power of analytical cytometry for the characterization of bacteria on the single-cell level.
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Affiliation(s)
- Lisa Budzinski
- Deutsches Rheuma-Forschungszentrum Berlin, a Leibniz Institute, Berlin, Germany; Institute for Biotechnology, Technische Universität Berlin, Berlin, Germany
| | - Andreas Radbruch
- Deutsches Rheuma-Forschungszentrum Berlin, a Leibniz Institute, Berlin, Germany
| | - Hyun-Dong Chang
- Deutsches Rheuma-Forschungszentrum Berlin, a Leibniz Institute, Berlin, Germany; Institute for Biotechnology, Technische Universität Berlin, Berlin, Germany.
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Mermans F, De Baets H, García-Timermans C, Teughels W, Boon N. Unlocking the mechanism of action: a cost-effective flow cytometry approach for accelerating antimicrobial drug development. Microbiol Spectr 2024; 12:e0393123. [PMID: 38483479 PMCID: PMC10986550 DOI: 10.1128/spectrum.03931-23] [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: 11/14/2023] [Accepted: 03/04/2024] [Indexed: 04/06/2024] Open
Abstract
Antimicrobial resistance is one of the greatest challenges to global health. While the development of new antimicrobials can combat resistance, low profitability reduces the number of new compounds brought to market. Elucidating the mechanism of action is crucial for developing new antimicrobials. This can become expensive as there are no universally applicable pipelines. Phenotypic heterogeneity of microbial populations resulting from antimicrobial treatment can be captured through flow cytometric fingerprinting. Since antimicrobials are classified into limited groups, the mechanism of action of known compounds can be used for predictive modeling. We demonstrate a cost-effective flow cytometry approach for determining the mechanism of action of new compounds. Cultures of Actinomyces viscosus and Fusobacterium nucleatum were treated with different antimicrobials and measured by flow cytometry. A Gaussian mixture mask was applied over the data to construct phenotypic fingerprints. Fingerprints were used to assess statistical differences between mechanism of action groups and to train random forest classifiers. Classifiers were then used to predict the mechanism of action of cephalothin. Statistical differences were found among the different mechanisms of action groups. Pairwise comparison showed statistical differences for 35 out of 45 pairs for A. viscosus and for 32 out of 45 pairs for F. nucleatum after 3.5 h of treatment. The best-performing random forest classifier yielded a Matthews correlation coefficient of 0.92 and the mechanism of action of cephalothin could be successfully predicted. These findings suggest that flow cytometry can be a cheap and fast alternative for determining the mechanism of action of new antimicrobials.IMPORTANCEIn the context of the emerging threat of antimicrobial resistance, the development of novel antimicrobials is a commonly employed strategy to combat resistance. Elucidating the mechanism of action of novel compounds is crucial in this development but can become expensive, as no universally applicable pipelines currently exist. We present a novel flow cytometry-based approach capable of determining the mechanism of action swiftly and cost-effectively. The workflow aims to accelerate drug discovery and could help facilitate a more targeted approach for antimicrobial treatment of patients.
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Affiliation(s)
- Fabian Mermans
- Center for Microbial Ecology and Technology, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium
- Department of Oral Health Sciences, KU Leuven & Dentistry (Periodontology), University Hospitals Leuven, Leuven, Belgium
| | - Hanna De Baets
- Center for Microbial Ecology and Technology, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium
| | - Cristina García-Timermans
- Center for Microbial Ecology and Technology, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium
| | - Wim Teughels
- Department of Oral Health Sciences, KU Leuven & Dentistry (Periodontology), University Hospitals Leuven, Leuven, Belgium
| | - Nico Boon
- Center for Microbial Ecology and Technology, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium
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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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Budzinski L, von Goetze V, Chang HD. Single-cell phenotyping of bacteria combined with deep sequencing for improved contextualization of microbiome analyses. Eur J Immunol 2024; 54:e2250337. [PMID: 37863831 DOI: 10.1002/eji.202250337] [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: 04/28/2023] [Revised: 10/17/2023] [Accepted: 10/19/2023] [Indexed: 10/22/2023]
Abstract
Great effort was made to characterize the bacterial communities inhabiting the human body as a factor in disease, resulting in the realization that a wide spectrum of diseases is associated with an altered composition of the microbiome. However, the identification of disease-relevant bacteria has been hindered by the high cross-sectional diversity of individual microbiomes, and in most cases, it remains unclear whether the observed alterations are cause or consequence of disease. Hence, innovative analysis approaches are required that enable inquiries of the microbiome beyond mere taxonomic cataloging. This review highlights the utility of microbiota flow cytometry, a single-cell analysis platform to directly interrogate cellular interactions, cell conditions, and crosstalk with the host's immune system within the microbiome to take into consideration the role of microbes as critical interaction partners of the host and the spectrum of microbiome alterations, beyond compositional changes. In conjunction with advanced sequencing approaches it could reveal the genetic potential of target bacteria and advance our understanding of taxonomic diversity and gene usage in the context of the microenvironment. Single-cell bacterial phenotyping has the potential to change our perspective on the human microbiome and empower microbiome research for the development of microbiome-based therapy approaches and personalized medicine.
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Affiliation(s)
- Lisa Budzinski
- Schwiete Laboratory for Microbiota and Inflammation, German Rheumatism Research Centre Berlin - A Leibniz Institute, Berlin, Germany
| | - Victoria von Goetze
- Schwiete Laboratory for Microbiota and Inflammation, German Rheumatism Research Centre Berlin - A Leibniz Institute, Berlin, Germany
| | - Hyun-Dong Chang
- Schwiete Laboratory for Microbiota and Inflammation, German Rheumatism Research Centre Berlin - A Leibniz Institute, Berlin, Germany
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Minnebo Y, De Paepe K, Raes J, Van de Wiele T. Eating patterns contribute to shaping the gut microbiota in the mucosal simulator of the human intestinal microbial ecosystem. FEMS Microbiol Ecol 2023; 99:fiad149. [PMID: 37974054 DOI: 10.1093/femsec/fiad149] [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: 05/26/2023] [Revised: 11/13/2023] [Accepted: 11/15/2023] [Indexed: 11/19/2023] Open
Abstract
Eating patterns, i.e. meal frequency and circadian timing of meals, are often modified in weight loss and metabolic healing strategies. However, in-depth research into the effects on the gut microbiome remains scarce, particularly across various colon regions and niches. We identified eating patterns to contribute in shaping the in vitro gut biomass production, metabolism, and microbial community compositions by subjecting four faecal microbiomes to a pattern that is standardized for a dynamic gut model (feeding at 09, 17, and 01 h), a typical Western (breakfast, lunch, and dinner at 09, 13, and 19 h, respectively), and a time-restricted pattern (single meal at 09 h). While eating patterns moderately affected the microbiome (2.4% and 1.8% significant variation in proportional and quantitative microbial compositions, respectively), significant changes were noted in the time-restricted pattern, including increased Bacteroides, Butyricicoccus, Dialister, and Faecalibacterium abundances. Sampling every 4 h revealed no significant circadian fluctuations in biomass production, microbial community compositions, or functionality. Longer fasting times favoured the growth of slower-growing species, such as Akkermansia, Dialister, and Parasutterella over faster-growers, such as Pseudomonas and Stenotrophomonas. Our findings illustrate the importance of recording and considering eating patterns as a gut microbiome determinant in in vivo and in vitro dietary intervention studies.
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Affiliation(s)
- Yorick Minnebo
- Center for Microbial Ecology and Technology, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Kim De Paepe
- Center for Microbial Ecology and Technology, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Jeroen Raes
- Laboratory of Molecular Bacteriology, Department of Microbiology and Immunology, KU Leuven, Herestraat 49, 3000 Leuven, Belgium
- Center for Microbiology, VIB, Herestraat 49, 3000 Leuven, Belgium
| | - Tom Van de Wiele
- Center for Microbial Ecology and Technology, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
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Castro GM, Vargens RP, Carlos-Júnior LA, Cardoso FC, Salomon PS, Tenório MMB, Bastos AC, Oliveira N, Ghisolfi RD, Cordeiro RTS, Moura RL. Incised valleys drive distinctive oceanographic processes and biological assemblages within rhodolith beds. PLoS One 2023; 18:e0293259. [PMID: 37956173 PMCID: PMC10642839 DOI: 10.1371/journal.pone.0293259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 10/09/2023] [Indexed: 11/15/2023] Open
Abstract
Continental shelves encompass gently sloped seascapes that are highly productive and intensively exploited for natural resources. Islands, reefs and other emergent or quasi-emergent features punctuate these shallow (<100 m) seascapes and are well known drivers of increased biomass and biodiversity, as well as predictors of fishing and other human uses. On the other hand, relict mesoscale geomorphological features that do not represent navigation hazards, such as incised valleys (IVs), remain poorly charted. Consequently, their role in biophysical processes remains poorly assessed and sampled. Incised valleys are common within rhodolith beds (RBs), the most extensive benthic habitat along the tropical and subtropical portions of the mid and outer Brazilian shelf. Here, we report on a multi-proxy assessment carried out in a tropical-subtropical transition region (~20°S) off Eastern Brazil, contrasting physicochemical and biological variables in IVs and adjacent RBs. Valleys interfere in near bottom circulation and function as conduits for water and propagules from the slope up to the mid shelf. In addition, they provide a stable and structurally complex habitat for black corals and gorgonians that usually occur in deeper water, contrasting sharply with the algae-dominated RB. Fish richness, abundance and biomass were also higher in the IVs, with small planktivores and large-bodied, commercially important species (e.g. groupers, snappers and grunts) presenting smaller abundances or being absent from RBs. Overall, IVs are unique and vulnerable habitats that sustain diverse assemblages and important ecosystem processes. As new IVs are detected by remote sensing or bathymetric surveys, they can be incorporated into regional marine management plans as conservation targets and priority sites for detailed in situ surveys.
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Affiliation(s)
- Guilherme M. Castro
- Instituto de Biologia and SAGE/COPPE, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Rafaela P. Vargens
- Departamento de Biologia, Pontifícia Universidade Católica do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Lélis A. Carlos-Júnior
- Departamento de Biologia, Pontifícia Universidade Católica do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Fernando C. Cardoso
- Instituto de Biologia and SAGE/COPPE, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Paulo S. Salomon
- Instituto de Biologia and SAGE/COPPE, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Márcio M. B. Tenório
- Instituto de Biologia and SAGE/COPPE, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Alex C. Bastos
- Departamento de Oceanografia, Universidade Federal do Espírito Santo, Vitória, Brazil
| | - Natacha Oliveira
- Departamento de Oceanografia, Universidade Federal do Espírito Santo, Vitória, Brazil
| | - Renato D. Ghisolfi
- Departamento de Oceanografia, Universidade Federal do Espírito Santo, Vitória, Brazil
| | - Ralf T. S. Cordeiro
- Departamento de Biologia, Universidade Federal Rural de Pernambuco, Recife, PE, Brazil
| | - Rodrigo L. Moura
- Instituto de Biologia and SAGE/COPPE, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
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11
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Minnebo Y, Delbaere K, Goethals V, Raes J, Van de Wiele T, De Paepe K. Gut microbiota response to in vitro transit time variation is mediated by microbial growth rates, nutrient use efficiency and adaptation to in vivo transit time. MICROBIOME 2023; 11:240. [PMID: 37926855 PMCID: PMC10626715 DOI: 10.1186/s40168-023-01691-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 10/05/2023] [Indexed: 11/07/2023]
Abstract
BACKGROUND Transit time is an important modulator of the human gut microbiome. The inability to modify transit time as the sole variable hampers mechanistic in vivo microbiome research. We singled out gut transit time in an unprecedented in vitro approach by subjecting faecal microbial communities from six individuals with either short, medium or long in vivo transit times, to three different colonic transit times of 21, 32 and 63 h in the validated human gut in vitro model, SHIME. RESULTS Transit time was identified as the single most important driver of microbial cell concentrations (52%), metabolic activity (45%) and quantitative (24%) and proportional (22%) community composition. Deceleration of transit was characterised by a significant decrease of specific Bifidobacterium and Veillonella spp. and increase of specific fibre degrading bacteria and nutrient specialists, such as Bacteroides, Prevotella, Ruminococcus, Bilophila and Akkermansia spp. These microbial communities reached a higher population density and net carbohydrate fermentation, leading to an increased SCFA production at longer transit times. In contrast, the carbohydrate-to-biomass production efficiency was increased at shorter transits, particularly in well-adapted faecal microbiomes from donors with short in vivo transit. Said adaptation was also reflected in the carbohydrate-to-SCFA conversion efficiency which varied with donor, but also colon region and SCFA chain length. A long transit time promoted propionate production, whereas butyrate production and butyrate producers were selectively enriched in the proximal colon at medium transit time. CONCLUSION Microbial growth rates and nutrient utilisation efficiency mediate the species-specific gut microbiota response to in vitro transit time variation, which is the main driver of in vitro microbial load, metabolism and community composition. Given the in vivo transit time variation within and between individuals, the personalisation of in vitro transit time based on in vivo data is required to accurately study intra- and inter-individual differences in gut microbiome structure, functionality and interactions with host and environmental modulators. Video Abstract.
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Affiliation(s)
- Yorick Minnebo
- Center for Microbial Ecology and Technology, Department of Biotechnology, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Karen Delbaere
- Center for Microbial Ecology and Technology, Department of Biotechnology, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Valerie Goethals
- Center for Microbial Ecology and Technology, Department of Biotechnology, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Jeroen Raes
- Laboratory of Molecular Bacteriology, Department of Microbiology and Immunology, KU Leuven, Herestraat 49, 3000, Leuven, Belgium
- Center for Microbiology, VIB, Herestraat 49, 3000, Leuven, Belgium
| | - Tom Van de Wiele
- Center for Microbial Ecology and Technology, Department of Biotechnology, Ghent University, Coupure Links 653, 9000, Ghent, Belgium.
| | - Kim De Paepe
- Center for Microbial Ecology and Technology, Department of Biotechnology, Ghent University, Coupure Links 653, 9000, Ghent, Belgium.
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12
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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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13
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Marcos-Fernández R, Sánchez B, Ruiz L, Margolles A. Convergence of flow cytometry and bacteriology. Current and future applications: a focus on food and clinical microbiology. Crit Rev Microbiol 2023; 49:556-577. [PMID: 35749433 DOI: 10.1080/1040841x.2022.2086035] [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: 07/19/2021] [Revised: 05/12/2022] [Accepted: 05/31/2022] [Indexed: 11/03/2022]
Abstract
Since its development in the 1960s, flow cytometry (FCM) was quickly revealed a powerful tool to analyse cell populations in medical studies, yet, for many years, was almost exclusively used to analyse eukaryotic cells. Instrument and methodological limitations to distinguish genuine bacterial signals from the background, among other limitations, have hampered FCM applications in bacteriology. In recent years, thanks to the continuous development of FCM instruments and methods with a higher discriminatory capacity to detect low-size particles, FCM has emerged as an appealing technique to advance the study of microbes, with important applications in research, clinical and industrial settings. The capacity to rapidly enumerate and classify individual bacterial cells based on viability facilitates the monitoring of bacterial presence in foodstuffs or clinical samples, reducing the time needed to detect contamination or infectious processes. Besides, FCM has stood out as a valuable tool to advance the study of complex microbial communities, or microbiomes, that are very relevant in the context of human health, as well as to understand the interaction of bacterial and host cells. This review highlights current developments in, and future applications of, FCM in bacteriology, with a focus on those related to food and clinical microbiology.
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Affiliation(s)
- Raquel Marcos-Fernández
- Department of Microbiology and Biochemistry of Dairy Products, Dairy Research Institute of Asturias, Spanish National Research Council (IPLA-CSIC), Asturias, Spain
- Functionality and Ecology of Beneficial Microbes (MicroHealth) Group, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Asturias, Spain
| | - Borja Sánchez
- Department of Microbiology and Biochemistry of Dairy Products, Dairy Research Institute of Asturias, Spanish National Research Council (IPLA-CSIC), Asturias, Spain
- Functionality and Ecology of Beneficial Microbes (MicroHealth) Group, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Asturias, Spain
| | - Lorena Ruiz
- Department of Microbiology and Biochemistry of Dairy Products, Dairy Research Institute of Asturias, Spanish National Research Council (IPLA-CSIC), Asturias, Spain
- Functionality and Ecology of Beneficial Microbes (MicroHealth) Group, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Asturias, Spain
| | - Abelardo Margolles
- Department of Microbiology and Biochemistry of Dairy Products, Dairy Research Institute of Asturias, Spanish National Research Council (IPLA-CSIC), Asturias, Spain
- Functionality and Ecology of Beneficial Microbes (MicroHealth) Group, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Asturias, Spain
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14
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Sabbe K, D'Haen L, Boon N, Ganigué R. Predicting the performance of chain elongating microbiomes through flow cytometric fingerprinting. WATER RESEARCH 2023; 243:120323. [PMID: 37459796 DOI: 10.1016/j.watres.2023.120323] [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: 03/23/2023] [Revised: 06/29/2023] [Accepted: 07/06/2023] [Indexed: 09/07/2023]
Abstract
As part of the circular bio-economy paradigm shift, waste management and valorisation practices have moved away from sanitation and towards the production of added-value compounds. Recently, the development of mixed culture bioprocess for the conversion of waste(water) to platform chemicals, such as medium chain carboxylic acids, has attracted significant interest. Often, the microbiology of these novel bioprocesses is less diverse and more prone to disturbances, which can lead to process failure. This issue can be tackled by implementing an advanced monitoring strategy based on the microbiology of the process. In this study, flow cytometry was used to monitor the microbiology of lactic acid chain elongation for the production of caproic acid, and assess its performance both qualitatively and quantitatively. Two continuous stirred tank reactors for chain elongation were monitored flow cytometrically for over 336 days. Through community typing, four specific community types could be identified and correlated to both a specific functionality and genotypic diversity. Additionally, the machine-learning algorithms trained in this study demonstrated the ability to predict production rates of, amongst others, caproic acid with high accuracy in the present (R² > 0.87) and intermediate accuracy in the near future (R² > 0.63). The identification of specific community types and the development of predictive algorithms form the basis of advanced bioprocess monitoring based on flow cytometry, and have the potential to improve bioprocess control and optimization, leading to better product quality and yields.
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Affiliation(s)
- Kevin Sabbe
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium; Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Frieda Saeysstraat 1, 9052 Ghent, Belgium
| | - Liese D'Haen
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Nico Boon
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium; Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Frieda Saeysstraat 1, 9052 Ghent, Belgium
| | - Ramon Ganigué
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium; Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Frieda Saeysstraat 1, 9052 Ghent, Belgium.
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15
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Mermans F, Mattelin V, Van den Eeckhoudt R, García-Timermans C, Van Landuyt J, Guo Y, Taurino I, Tavernier F, Kraft M, Khan H, Boon N. Opportunities in optical and electrical single-cell technologies to study microbial ecosystems. Front Microbiol 2023; 14:1233705. [PMID: 37692384 PMCID: PMC10486927 DOI: 10.3389/fmicb.2023.1233705] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 08/03/2023] [Indexed: 09/12/2023] Open
Abstract
New techniques are revolutionizing single-cell research, allowing us to study microbes at unprecedented scales and in unparalleled depth. This review highlights the state-of-the-art technologies in single-cell analysis in microbial ecology applications, with particular attention to both optical tools, i.e., specialized use of flow cytometry and Raman spectroscopy and emerging electrical techniques. The objectives of this review include showcasing the diversity of single-cell optical approaches for studying microbiological phenomena, highlighting successful applications in understanding microbial systems, discussing emerging techniques, and encouraging the combination of established and novel approaches to address research questions. The review aims to answer key questions such as how single-cell approaches have advanced our understanding of individual and interacting cells, how they have been used to study uncultured microbes, which new analysis tools will become widespread, and how they contribute to our knowledge of ecological interactions.
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Affiliation(s)
- Fabian Mermans
- Center for Microbial Ecology and Technology (CMET), Department of Biotechnology, Ghent University, Ghent, Belgium
- Department of Oral Health Sciences, KU Leuven, Leuven, Belgium
| | - Valérie Mattelin
- Center for Microbial Ecology and Technology (CMET), Department of Biotechnology, Ghent University, Ghent, Belgium
| | - Ruben Van den Eeckhoudt
- Micro- and Nanosystems (MNS), Department of Electrical Engineering (ESAT), KU Leuven, Leuven, Belgium
| | - Cristina García-Timermans
- Center for Microbial Ecology and Technology (CMET), Department of Biotechnology, Ghent University, Ghent, Belgium
| | - Josefien Van Landuyt
- Center for Microbial Ecology and Technology (CMET), Department of Biotechnology, Ghent University, Ghent, Belgium
| | - Yuting Guo
- Center for Microbial Ecology and Technology (CMET), Department of Biotechnology, Ghent University, Ghent, Belgium
| | - Irene Taurino
- Micro- and Nanosystems (MNS), Department of Electrical Engineering (ESAT), KU Leuven, Leuven, Belgium
- Semiconductor Physics, Department of Physics and Astronomy, KU Leuven, Leuven, Belgium
| | - Filip Tavernier
- MICAS, Department of Electrical Engineering (ESAT), KU Leuven, Leuven, Belgium
| | - Michael Kraft
- Micro- and Nanosystems (MNS), Department of Electrical Engineering (ESAT), KU Leuven, Leuven, Belgium
- Leuven Institute of Micro- and Nanoscale Integration (LIMNI), KU Leuven, Leuven, Belgium
| | - Hira Khan
- Center for Microbial Ecology and Technology (CMET), Department of Biotechnology, Ghent University, Ghent, Belgium
| | - Nico Boon
- Center for Microbial Ecology and Technology (CMET), Department of Biotechnology, Ghent University, Ghent, Belgium
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16
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Wijaya W, Suhaimi Z, Chua CX, Sunil RS, Kolundžija S, Rohaizat AMB, Azmi NBM, Hazrin-Chong NH, Lauro FM. Frequent pulse disturbances shape resistance and resilience in tropical marine microbial communities. ISME COMMUNICATIONS 2023; 3:55. [PMID: 37280348 PMCID: PMC10244338 DOI: 10.1038/s43705-023-00260-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 05/02/2023] [Accepted: 05/24/2023] [Indexed: 06/08/2023]
Abstract
The Johor Strait separates the island of Singapore from Peninsular Malaysia. A 1-kilometer causeway built in the early 1920s in the middle of the strait effectively blocks water flowing to/from either side, resulting in low water turnover rates and build-up of nutrients in the inner Strait. We have previously shown that short-term rather than seasonal environmental changes influence microbial community composition in the Johor Strait. Here, we present a temporally-intensive study that uncovers the factors keeping the microbial populations in check. We sampled the surface water at four sites in the inner Eastern Johor Strait every other day for two months, while measuring various water quality parameters, and analysed 16S amplicon sequences and flow-cytometric counts. We discovered that microbial community succession revolves around a common stable state resulting from frequent pulse disturbances. Among these, sporadic riverine freshwater input and regular tidal currents influence bottom-up controls including the availability of the limiting nutrient nitrogen and its biological release in readily available forms. From the top-down, marine viruses and predatory bacteria limit the proliferation of microbes in the water. Harmful algal blooms, which have been observed historically in these waters, may occur only when there are simultaneous gaps in the top-down and bottom-up controls. This study gains insight into complex interactions between multiple factors contributing to a low-resistance but high-resilience microbial community and speculate about rare events that could lead to the occurrence of an algal bloom.
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Affiliation(s)
- Winona Wijaya
- Asian School of the Environment, Nanyang Technological University, Singapore, Singapore
| | - Zahirah Suhaimi
- Department of Anthropology, University of California Santa Cruz, Santa Cruz, CA, USA
- Center for Southeast Asian Coastal Interactions, Santa Cruz, CA, USA
| | - Cherlyn Xin'Er Chua
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Rohan Shawn Sunil
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Sandra Kolundžija
- Asian School of the Environment, Nanyang Technological University, Singapore, Singapore
| | | | - Norzarifah Binti Md Azmi
- Department of Biological Sciences and Biotechnology, Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia
| | - Nur Hazlin Hazrin-Chong
- Department of Biological Sciences and Biotechnology, Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia
| | - Federico M Lauro
- Asian School of the Environment, Nanyang Technological University, Singapore, Singapore.
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore.
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17
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Mattelin V, Verfaille L, Kundu K, De Wildeman S, Boon N. A New Colorimetric Test for Accurate Determination of Plastic Biodegradation. Polymers (Basel) 2023; 15:polym15102311. [PMID: 37242886 DOI: 10.3390/polym15102311] [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: 04/07/2023] [Revised: 05/03/2023] [Accepted: 05/06/2023] [Indexed: 05/28/2023] Open
Abstract
As plastic waste is accumulating in both controlled waste management settings and natural settings, much research is devoted to search for solutions, also in the field of biodegradation. However, determining the biodegradability of plastics in natural environments remains a big challenge due to the often very low biodegradation rates. Many standardised test methods for biodegradation in natural environments exist. These are often based on mineralisation rates in controlled conditions and are thus indirect measurements of biodegradation. It is of interest for both researchers and companies to have tests that are more rapid, easier, and more reliable to screen different ecosystems and/or niches for their plastic biodegradation potential. In this study, the goal is to validate a colorimetric test, based on carbon nanodots, to screen biodegradation of different types of plastics in natural environments. After introducing carbon nanodots into the matrix of the target plastic, a fluorescent signal is released upon plastic biodegradation. The in-house-made carbon nanodots were first confirmed regarding their biocompatibility and chemical and photostability. Subsequently, the effectivity of the developed method was evaluated positively by an enzymatic degradation test with polycaprolactone with Candida antarctica lipase B. Finally, validation experiments were performed with enriched microorganisms and real environmental samples (freshwater and seawater), of which the results were compared with parallel, frequently used biodegradation measures such as O2 and CO2, dissolved organic carbon, growth and pH, to assess the reliability of the test. Our results indicate that this colorimetric test is a good alternative to other methods, but a combination of different methods gives the most information. In conclusion, this colorimetric test is a good fit to screen, in high throughput, the depolymerisation of plastics in natural environments and under different conditions in the lab.
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Affiliation(s)
- Valérie Mattelin
- Center for Microbial Ecology and Technology (CMET), Ghent University, 9000 Ghent, Belgium
| | - Lennert Verfaille
- Center for Microbial Ecology and Technology (CMET), Ghent University, 9000 Ghent, Belgium
| | - Kankana Kundu
- Center for Microbial Ecology and Technology (CMET), Ghent University, 9000 Ghent, Belgium
| | | | - Nico Boon
- Center for Microbial Ecology and Technology (CMET), Ghent University, 9000 Ghent, Belgium
- Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), 9000 Ghent, Belgium
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18
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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: 3] [Impact Index Per Article: 3.0] [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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19
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Shan Y, Guo Y, Jiao W, Zeng P. Single-Cell Techniques in Environmental Microbiology. Processes (Basel) 2023. [DOI: 10.3390/pr11041109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023] Open
Abstract
Environmental microbiology has been an essential part of environmental research because it provides effective solutions to most pollutants. Hence, there is an interest in investigating microorganism behavior, such as observation, identification, isolation of pollutant degraders, and interactions between microbial species. To comprehensively understand cell heterogeneity, diverse approaches at the single-cell level are demanded. Thus far, the traditional bulk biological tools such as petri dishes are technically challenging for single cells, which could mask the heterogeneity. Single-cell technologies can reveal complex and rare cell populations by detecting heterogeneity among individual cells, which offers advantages of higher resolution, higher throughput, more accurate analysis, etc. Here, we overviewed several single-cell techniques on observation, isolation, and identification from aspects of methods and applications. Microscopic observation, sequencing identification, flow cytometric identification and isolation, Raman spectroscopy-based identification and isolation, and their applications are mainly discussed. Further development on multi-technique integrations at the single-cell level may highly advance the research progress of environmental microbiology, thereby giving more indication in the environmental microbial ecology.
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Affiliation(s)
- Yongping Shan
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yuting Guo
- Flow Cytometry Center, National Institute of Biological Sciences, Beijing 102206, China
| | - Wentao Jiao
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Ping Zeng
- Department of Urban Water Environmental Research, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
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20
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Hyun BS, Cape MR, Ribalet F, Bien J. MODELING CELL POPULATIONS MEASURED BY FLOW CYTOMETRY WITH COVARIATES USING SPARSE MIXTURE OF REGRESSIONS. Ann Appl Stat 2023; 17:357-377. [PMID: 37485300 PMCID: PMC10360992 DOI: 10.1214/22-aoas1631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
The ocean is filled with microscopic microalgae, called phytoplankton, which together are responsible for as much photosynthesis as all plants on land combined. Our ability to predict their response to the warming ocean relies on understanding how the dynamics of phytoplankton populations is influenced by changes in environmental conditions. One powerful technique to study the dynamics of phytoplankton is flow cytometry which measures the optical properties of thousands of individual cells per second. Today, oceanographers are able to collect flow cytometry data in real time onboard a moving ship, providing them with fine-scale resolution of the distribution of phytoplankton across thousands of kilometers. One of the current challenges is to understand how these small- and large-scale variations relate to environmental conditions, such as nutrient availability, temperature, light and ocean currents. In this paper we propose a novel sparse mixture of multivariate regressions model to estimate the time-varying phytoplankton subpopulations while simultaneously identifying the specific environmental covariates that are predictive of the observed changes to these subpopulations. We demonstrate the usefulness and interpretability of the approach using both synthetic data and real observations collected on an oceanographic cruise conducted in the northeast Pacific in the spring of 2017.
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Affiliation(s)
- By Sangwon Hyun
- Department of Data Sciences and Operations, University of Southern California
| | | | | | - Jacob Bien
- Department of Data Sciences and Operations, University of Southern California
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21
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Winners and Losers of Atlantification: The Degree of Ocean Warming Affects the Structure of Arctic Microbial Communities. Genes (Basel) 2023; 14:genes14030623. [PMID: 36980894 PMCID: PMC10048660 DOI: 10.3390/genes14030623] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/24/2023] [Accepted: 02/25/2023] [Indexed: 03/06/2023] Open
Abstract
Arctic microbial communities (i.e., protists and bacteria) are increasingly subjected to an intrusion of new species via Atlantification and an uncertain degree of ocean warming. As species differ in adaptive traits, these oceanic conditions may lead to compositional changes with functional implications for the ecosystem. In June 2021, we incubated water from the western Fram Strait at three temperatures (2 °C, 6 °C, and 9 °C), mimicking the current and potential future properties of the Arctic Ocean. Our results show that increasing the temperature to 6 °C only minorly affects the community, while an increase to 9 °C significantly lowers the diversity and shifts the composition. A higher relative abundance of large hetero- and mixotrophic protists was observed at 2 °C and 6 °C compared to a higher abundance of intermediate-sized temperate diatoms at 9 °C. The compositional differences at 9 °C led to a higher chlorophyll a:POC ratio, but the C:N ratio remained similar. Our results contradict the common assumption that smaller organisms and heterotrophs are favored under warming and strongly indicate a thermal limit between 6 °C and 9 °C for many Arctic species. Consequently, the magnitude of temperature increase is a crucial factor for microbial community reorganization and the ensuing ecological consequences in the future Arctic Ocean.
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22
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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: 4.0] [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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Pernice MC, Gasol JM. Automated flow cytometry as a tool to obtain a fine-grain picture of marine prokaryote community structure along an entire oceanographic cruise. Front Microbiol 2023; 13:1064112. [PMID: 36687618 PMCID: PMC9853387 DOI: 10.3389/fmicb.2022.1064112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 12/12/2022] [Indexed: 01/08/2023] Open
Abstract
On a standard oceanographic cruise, flow cytometry data are usually collected sparsely through a bottle-based sampling and with stations separated by kilometers leading to a fragmented view of the ecosystem; to improve the resolution of the datasets produced by this technique here it is proposed the application of an automatic method of sampling and staining. The system used consists of a flow-cytometer (Accuri-C6) connected to an automated continuous sampler (OC-300) that collects samples of marine surface waters every 15 min. We tested this system for five days during a brief Mediterranean cruise with the aim of estimating the abundance, relative size and phenotypic diversity of prokaryotes. Seawater was taken by a faucet linked to an inlet pump (ca. 5 m depth). Once the sample was taken, the Oncyt-300 stained it and sent it to the flow cytometer. A total of 366 samples were collected, effectively achieving a fine-grained scale view of microbial community composition both through space and time. A significative positive relationship was found comparing data obtained with the automatic method and 10 samples collected from the faucet but processed with the standard protocol. Abundance values retrieved varied from 3.56·105 cell mL-1 in the coastal area till 6.87 105 cell mL-1 in open waters, exceptional values were reached in the harbor area where abundances peaked to 1.28 106 cell mL-1. The measured features (abundance and size) were associated with metadata (temperature, salinity, conductivity) also taken in continuous, of which conductivity was the one that better explained the variability of abundance. A full 24 h measurement cycle was performed resulting in slightly higher median bacterial abundances values during daylight hours compared to night. Alpha diversity, calculated using computational cytometry techniques, showed a higher value in the coastal area above 41° of latitude and had a strong inverse relationship with both salinity and conductivity. This is the first time to our knowledge that the OC-300 is directly applied to the marine environment during an oceanographic cruise; due to its high-resolution, this set-up shows great potential both to cover large sampling areas, and to monitor day-night cycles in situ.
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24
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Zayed N, Figueiredo J, Van Holm W, Boon N, Bernaerts K, Teughels W. Mode of killing determines the necrotrophic response of oral bacteria. J Oral Microbiol 2023; 15:2184930. [PMID: 36926228 PMCID: PMC10013485 DOI: 10.1080/20002297.2023.2184930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023] Open
Abstract
Background Bacteria respond to changes in their environment, such as nutrient depletion and antimicrobials exposure. Antimicrobials result not only in bacterial death, but also have a hand in determining species abundances and ecology of the oral biofilms. Proximity of dead bacterial cells to living ones is an important environmental change or stress factor. Dead bacteria represent high concentrations of nutrients, such as proteins, lipids, sugars, and nucleic acids. Living bacteria can use these biomasses as a nutrients source, which is termed necrotrophy. Aim This study investigates the effect of exposing living oral bacteria (planktonic and biofilms) to their dead siblings after being killed by heat or hydrogen peroxide. Results Tested bacterial species showed different responses towards the dead cells, depending on the mode of killing, the nutritional value of the culture media, and the the dead cells density. The multispecies oral biofilms showed different responses towards the supplementation of dead cells during biofilm development, while matured biofilms were more resilient. Conclusion This study indicates that dead bacteria resulting from antiseptics use may imbalance the nutrient availability in the oral cavity, resulting in overgrowth of opportunistic species, and hence ecological changes in oral communities, or introducing new bacterial phenotypes.
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Affiliation(s)
- Naiera Zayed
- Department of Oral Health Sciences, University of Leuven (KU Leuven), Leuven, Belgium.,Center for Microbial Ecology and Technology (CMET), Ghent University (UGent), Gent, Belgium.,Faculty of Pharmacy, Menoufia University, Shebin El-Kom, Egypt
| | - Joana Figueiredo
- Faculty of bioscience engineering, University of Minho, Braga, Portugal
| | - Wannes Van Holm
- Department of Oral Health Sciences, University of Leuven (KU Leuven), Leuven, Belgium.,Center for Microbial Ecology and Technology (CMET), Ghent University (UGent), Gent, Belgium
| | - Nico Boon
- Center for Microbial Ecology and Technology (CMET), Ghent University (UGent), Gent, Belgium
| | - Kristel Bernaerts
- Chemical and Biochemical Reactor Engineering and Safety, Department of Chemical Engineering, University of Leuven (KU Leuven), Leuven Chem&Tech, Leuven, Belgium
| | - Wim Teughels
- Department of Oral Health Sciences, University of Leuven (KU Leuven), Leuven, Belgium
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25
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Mijnendonckx K, Bleyen N, Van Gompel A, Coninx I, Leys N. pH and microbial community determine the denitrifying activity in the presence of nitrate-containing radioactive waste. Front Microbiol 2022; 13:968220. [PMID: 36338040 PMCID: PMC9634998 DOI: 10.3389/fmicb.2022.968220] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 09/20/2022] [Indexed: 01/24/2023] Open
Abstract
An important fraction of the currently stored volume of long-lived intermediate-level radioactive waste in Belgium contains large amounts of NaNO3 homogeneously dispersed in a hard bituminous matrix. Geological disposal of this waste form in a water-saturated sedimentary formation such as Boom Clay will result in the leaching of high concentrations of NaNO3, which could cause a geochemical perturbation of the surrounding clay, possibly affecting some of the favorable characteristics of the host formation. In addition, hyper-alkaline conditions are expected for thousands of years, imposed by the cementitious materials used as backfill material. Microbial nitrate reduction is a well-known process and can result in the accumulation of nitrite or nitrogenous gases. This could lead to the oxidation of redox-active Boom Clay components, which could (locally) decrease the reducing capacity of the clay formation. Here, we compared nitrate reduction processes between two microbial communities at different pH related to a geological repository environment and in the presence of a nitrate-containing waste simulate during 1 year in batch experiments. We showed that the microbial community from in Boom Clay borehole water was able to carry out nitrate reduction in the presence of acetate at pH 10.5, although the maximum rate of 1.3 ± 0.2 mM NO3 -/day was much lower compared to that observed at pH 9 (2.9 mM NO3 -/day). However, microbial activity at pH 10.5 was likely limited by a phosphate shortage. This study further confirmed that the Harpur Hill sediment harbors a microbial community adapted to high pH conditions. It reduced twice as much nitrate at pH 10.5 compared to pH 9 and the maximum nitrate reduction rate was higher at pH 10.5 compared to that at pH 9, i.e., 3.4 ± 0.8 mM NO3 -/day versus 2.2 ± 0.4 mM NO3 -/day. Both communities were able to form biofilms on non-radioactive Eurobitum. However, for both microbial communities, pH 12.5 seems to be a limiting condition for microbial activity as no nitrate reduction nor biofilm was observed. Nevertheless, pH alone is not sufficient to eliminate microbial presence, but it can induce a significant shift in the microbial community composition and reduce its nitrate reducing activity. Furthermore, at the interface between the cementitious disposal gallery and the clay host rock, the pH will not be sufficiently high to inhibit microbial nitrate reduction.
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Affiliation(s)
- Kristel Mijnendonckx
- Unit of Microbiology, SCK CEN, Mol, Belgium,*Correspondence: Kristel Mijnendonckx,
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26
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Lee TA, Steel H. Cybergenetic control of microbial community composition. Front Bioeng Biotechnol 2022; 10:957140. [PMID: 36277404 PMCID: PMC9582452 DOI: 10.3389/fbioe.2022.957140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 09/20/2022] [Indexed: 11/13/2022] Open
Abstract
The use of bacterial communities in bioproduction instead of monocultures has potential advantages including increased productivity through division of labour, ability to utilise cheaper substrates, and robustness against perturbations. A key challenge in the application of engineered bacterial communities is the ability to reliably control the composition of the community in terms of its constituent species. This is crucial to prevent faster growing species from outcompeting others with a lower relative fitness, and to ensure that all species are present at an optimal ratio during different steps in a biotechnological process. In contrast to purely biological approaches such as synthetic quorum sensing circuits or paired auxotrophies, cybergenetic control techniques - those in which computers interface with living cells-are emerging as an alternative approach with many advantages. The community composition is measured through methods such as fluorescence intensity or flow cytometry, with measured data fed real-time into a computer. A control action is computed using a variety of possible control algorithms and then applied to the system, with actuation taking the form of chemical (e.g., inducers, nutrients) or physical (e.g., optogenetic, mechanical) inputs. Subsequent changes in composition are then measured and the cycle repeated, maintaining or driving the system to a desired state. This review discusses recent and future developments in methods for implementing cybergenetic control systems, contrasts their capabilities with those of traditional biological methods of population control, and discusses future directions and outstanding challenges for the field.
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27
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Wennberg AC, Meland S, Grung M, Lillicrap A. Unravelling reasons for variability in the OECD 306 marine biodegradation test. CHEMOSPHERE 2022; 300:134476. [PMID: 35367489 DOI: 10.1016/j.chemosphere.2022.134476] [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: 01/04/2022] [Revised: 03/26/2022] [Accepted: 03/28/2022] [Indexed: 06/14/2023]
Abstract
The recommended test for assessing if a chemical can be biodegraded in the marine environment is performed according to the Organisation for Economic Cooperation and Development Marine biodegradation test guideline (OECD 306). However, this test is known to generate highly variable test results when comparing interlaboratory test results for the same compound. One reason can be the relatively low bacterial content compared to the inoculum used for OECD readily biodegradation tests (OECD 301). Some of the variability in data obtained from OECD 306 tests can also be due to the flexibility on how to store the seawater inoculum before starting a test. Another variable in the seawater inoculum is the source of seawater used by different laboratories, i.e., geographical location and anthropogenic activities at the source. In this study, the effect of aging seawater and the source of seawater (sample time and depth) were investigated to determine differences in the biodegradation of the reference compound aniline. Aging the seawater before starting the test is recommended in OECD 306 to reduce the background levels of organic carbon in the water. However, it also functions to acclimatize the bacterial community from the environmental source temperature to the test temperature (normally 20 °C). Herein, the microbial community was monitored using flowcytometer during the aging process. As expected, the microbial community changed over time. In one experiment, aging significantly improved the biodegradation of aniline, while in two experiments, there was no significant difference in biodegradation. Interestingly however, there was significant variability in the biodegradation of aniline between sampling seasons and depths, even when all experiments were performed in the same lab, by the same operator and seawater obtained from the same source. This highlights the need for a more robust and consistent microbial inoculum source to reduce variability in seawater biodegradation tests.
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Affiliation(s)
| | - Sondre Meland
- Norwegian Institute for Water Research (NIVA), Økernveien 94, NO-0579, Oslo, Norway
| | - Merete Grung
- Norwegian Institute for Water Research (NIVA), Økernveien 94, NO-0579, Oslo, Norway
| | - Adam Lillicrap
- Norwegian Institute for Water Research (NIVA), Økernveien 94, NO-0579, Oslo, Norway
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In vitro triple coculture with gut microbiota from spondyloarthritis patients is characterized by inter-individual differences in inflammatory responses. Sci Rep 2022; 12:10475. [PMID: 35729185 PMCID: PMC9213446 DOI: 10.1038/s41598-022-13582-7] [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: 02/07/2022] [Accepted: 05/25/2022] [Indexed: 11/08/2022] Open
Abstract
Spondyloarthritis is a group of chronic inflammatory diseases that primarily affects axial or peripheral joints and is frequently associated with inflammation at non-articular sites. The disease is multifactorial, involving genetics, immunity and environmental factors, including the gut microbiota. In vivo, microbiome contributions are difficult to assess due to the multifactorial disease complexity. In a proof-of-concept approach, we therefore used a triple coculture model of immune-like, goblet and epithelial cells to investigate whether we could detect a differential impact from spondyloarthritis- vs. healthy-derived gut microbiota on host cell response. Despite their phylogenetic resemblance, flow cytometry-based phenotypic clustering revealed human-derived gut microbiota from healthy origin to cluster together and apart from spondyloarthritis donors. At host level, mucus production was higher upon exposure to healthy microbiota. Pro-inflammatory cytokine responses displayed more inter-individual variability in spondyloarthritis than in healthy donors. Interestingly, the high dominance in the initial sample of one patient of Prevotella, a genus previously linked to spondyloarthritis, resulted in the most differential host response upon 16 h host-microbe coincubation. While future research should further focus on inter-individual variability by using gut microbiota from a large cohort of patients, this study underscores the importance of the gut microbiota during the SpA disease course.
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29
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Bacterial, Phytoplankton, and Viral Distributions and Their Biogeochemical Contexts in Meromictic Lake Cadagno Offer Insights into the Proterozoic Ocean Microbial Loop. mBio 2022; 13:e0005222. [PMID: 35726916 PMCID: PMC9426590 DOI: 10.1128/mbio.00052-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lake Cadagno, a permanently stratified high-alpine lake with a persistent microbial bloom in its chemocline, has long been considered a model for the low-oxygen, high-sulfide Proterozoic ocean. Although the lake has been studied for over 25 years, the absence of concerted study of the bacteria, phytoplankton, and viruses, together with primary and secondary production, has hindered a comprehensive understanding of its microbial food web. Here, the identities, abundances, and productivity of microbes were evaluated in the context of Lake Cadagno biogeochemistry. Photosynthetic pigments together with 16S rRNA gene phylogenies suggest the prominence of eukaryotic phytoplankton chloroplasts, primarily chlorophytes. Chloroplasts closely related to those of high-alpine-adapted Ankyra judayi persisted with oxygen in the mixolimnion, where photosynthetic efficiency was high, while chloroplasts of Closteriopsis-related chlorophytes peaked in the chemocline and monimolimnion. The anoxygenic phototrophic sulfur bacterium Chromatium dominated the chemocline along with Lentimicrobium, a genus of known fermenters. Secondary production peaked in the chemocline, which suggested that anoxygenic primary producers depended on heterotrophic nutrient remineralization. The virus-to-microbe ratio peaked with phytoplankton abundances in the mixolimnion and were at a minimum where Chromatium abundance was highest, trends that suggest that viruses may play a role in the modulation of primary production. Through the combined analysis of bacterial, eukaryotic, viral, and biogeochemical spatial dynamics, we provide a comprehensive synthesis of the Lake Cadagno microbial loop. This study offers a new ecological perspective on how biological and geochemical connections may have occurred in the chemocline of the Proterozoic ocean, where eukaryotic microbial life is thought to have evolved.
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30
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Schmiester M, Maier R, Riedel R, Durek P, Frentsch M, Kolling S, Mashreghi MF, Jenq R, Zhang L, Peterson CB, Bullinger L, Chang HD, Na IK. Flow cytometry can reliably capture gut microbial composition in healthy adults as well as dysbiosis dynamics in patients with aggressive B-cell non-Hodgkin lymphoma. Gut Microbes 2022; 14:2081475. [PMID: 35634713 PMCID: PMC9154785 DOI: 10.1080/19490976.2022.2081475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Modulation of commensal gut microbiota is increasingly recognized as a promising strategy to reduce mortality in patients with malignant diseases, but monitoring for dysbiosis is generally not routine clinical practice due to equipment, expertise and funding required for sequencing analysis. A low-threshold alternative is microbial diversity profiling by single-cell flow cytometry (FCM), which we compared to 16S rRNA sequencing in human fecal samples and employed to characterize longitudinal changes in the microbiome composition of patients with aggressive B-cell non-Hodgkin lymphoma undergoing chemoimmunotherapy. Diversity measures obtained from both methods were correlated and captured identical trends in microbial community structures, finding no difference in patients' pretreatment alpha or beta diversity compared to healthy controls and a significant and progressive loss of alpha diversity during chemoimmunotherapy. Our results highlight the potential of FCM-based microbiome profiling as a reliable and accessible diagnostic tool that can provide novel insights into cancer therapy-associated dysbiosis dynamics.
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Affiliation(s)
- Maren Schmiester
- Department of Hematology, Oncology and Tumor Immunology, Charité-Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany,Berlin Institute of Health at Charité, Universitätsmedizin Berlin, Berlin, Germany,CONTACT Maren Schmiester Department of Hematology, Oncology and Tumor Immunology, Charité-Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin', Berlin, Germany
| | - René Maier
- Deutsches Rheuma-Forschungszentrum Berlin (DRFZ), an Institute of the Leibniz Association, Berlin, Germany
| | - René Riedel
- Deutsches Rheuma-Forschungszentrum Berlin (DRFZ), an Institute of the Leibniz Association, Berlin, Germany
| | - Pawel Durek
- Deutsches Rheuma-Forschungszentrum Berlin (DRFZ), an Institute of the Leibniz Association, Berlin, Germany
| | - Marco Frentsch
- BIH Center for Regenerative Therapies (BCRT), Berlin Institute of Health at Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Stefan Kolling
- BIH Center for Regenerative Therapies (BCRT), Berlin Institute of Health at Charité – Universitätsmedizin Berlin, Berlin, Germany,Berlin School of Integrative Oncology, Berlin, Germany
| | - Mir-Farzin Mashreghi
- BIH Center for Regenerative Therapies (BCRT), Berlin Institute of Health at Charité – Universitätsmedizin Berlin, Berlin, Germany,(DRFZ), an Institute of the Leibniz AssociationTherapeutic Gene Regulation, Deutsches Rheuma-Forschungszentrum, Berlin, Germany
| | - Robert Jenq
- Department of Genomic Medicine, the University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Liangliang Zhang
- Department of Population and Quantitative Health Sciences, Case Western Reserve University, Cleveland, OH, USA
| | - Christine B. Peterson
- Department of Biostatistics, the University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Lars Bullinger
- Department of Hematology, Oncology and Tumor Immunology, Charité-Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany,German Cancer Research Center (DKFZ), Heidelberg, Germany,German Cancer Consortium (DKTK), Berlin, Germany
| | - Hyun-Dong Chang
- Deutsches Rheuma-Forschungszentrum Berlin (DRFZ), an Institute of the Leibniz Association, Berlin, Germany,Institute of Biotechnology, Technische Universität Berlin, Germany
| | - Il-Kang Na
- Department of Hematology, Oncology and Tumor Immunology, Charité-Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany,BIH Center for Regenerative Therapies (BCRT), Berlin Institute of Health at Charité – Universitätsmedizin Berlin, Berlin, Germany,German Cancer Consortium (DKTK), Berlin, Germany,ECRC Experimental and Clinical Research Center, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Berlin, Germany
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31
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Technical pipeline for screening microbial communities as a function of substrate specificity through fluorescent labelling. Commun Biol 2022; 5:444. [PMID: 35545700 PMCID: PMC9095699 DOI: 10.1038/s42003-022-03383-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 04/20/2022] [Indexed: 12/16/2022] Open
Abstract
The study of specific glycan uptake and metabolism is an effective tool in aiding with the continued unravelling of the complexities in the human gut microbiome. To this aim fluorescent labelling of glycans may provide a powerful route towards this target. Here, we successfully used the fluorescent label 2-aminobenzamide (2-AB) to monitor and study microbial degradation of labelled glycans. Both single strain and co-cultured fermentations of microbes from the common human-gut derived Bacteroides genus, are able to grow when supplemented with 2-AB labelled glycans of different monosaccharide composition, degrees of acetylation and polymerization. Utilizing a multifaceted approach that combines chromatography, mass spectrometry, microscopy and flow cytometry techniques, it is possible to better understand the metabolism of labelled glycans in both supernatants and at a single cell level. We envisage this combination of complementary techniques will help further the understanding of substrate specificity and the role it plays within microbial communities. A reductive amination-based fluorophore labelling of complex wood-derived glycans provides a proof-of-principle multi-modal platform for monitoring glycan uptake by bacteria.
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El Mujtar VA, Chirdo F, Lagares A, Wall L, Tittonell P. Soil bacterial biodiversity characterization by flow cytometry: The bottleneck of cell extraction from soil. Methods Ecol Evol 2022. [DOI: 10.1111/2041-210x.13876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Verónica A. El Mujtar
- Agroecology, Environment and Systems Group, Instituto de Investigaciones Forestales y Agropecuarias de Bariloche (IFAB) INTA‐CONICET, San Carlos de Bariloche Río Negro Argentina
| | - Fernando Chirdo
- Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP)(UNLP‐CONICET), Facultad de Ciencias Exactas Universidad Nacional de La Plata La Plata Argentina
| | - Antonio Lagares
- IBBM—Instituto de Biotecnología y Biología Molecular, Facultad de Ciencias Exactas Universidad Nacional de La Plata, CCT‐La Plata CONICET La Plata Argentina
| | - Luis Wall
- Laboratorio de Bioquímica y Microbiología de Suelo, Centro de Bioquímica y Microbiología de Suelos Universidad Nacional de Quilmes Bernal Argentina
| | - Pablo Tittonell
- Agroecology, Environment and Systems Group, Instituto de Investigaciones Forestales y Agropecuarias de Bariloche (IFAB) INTA‐CONICET, San Carlos de Bariloche Río Negro Argentina
- Groningen Institute of Evolutionary Life Sciences Groningen University Groningen The Netherlands
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Gregson BH, Bani A, Steinfield L, Holt D, Whitby C. Anaerobes and methanogens dominate the microbial communities in water harvesting ponds used by Kenyan rural smallholder farmers. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 819:153040. [PMID: 35026246 DOI: 10.1016/j.scitotenv.2022.153040] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 01/06/2022] [Accepted: 01/06/2022] [Indexed: 06/14/2023]
Abstract
Many rural smallholder farmers in Kenya use water-harvesting ponds, to collect rainwater, as sustainable sources of water for domestic and agricultural purposes. There is currently limited information regarding the microbial ecology in these ponds. Here, we used High Throughput Sequencing (HTS) to characterize the microorganisms present (including potential pathogens and indicator species) alongside ion chromatography to measure water chemistry (anion and cation concentration). Fluoride and magnesium concentration were the strongest predictor variables of the microbial community. Obligately or facultatively anaerobic bacterial genera (e.g. Spirochaeta and Opitutus) were abundant within the bacterial community, whilst Woesearchaeota and methanogens dominated the archaeal community. This suggests the water in the ponds is hypoxic or anoxic, and if used for irrigation, may potentially impact crop yield and viability. In addition, the opportunistic pathogen non-tuberculous mycobacteria (NTM), Mycobacterium fortuitum was found, comprising >1% of the bacterial community, suggesting a potential human health risk. Here we suggest low-cost changes to pond management, to improve or ameliorate pond anoxia and remove pathogens to benefit the livelihoods and welfare of these farms. This study also shows the applicability of HTS to broadly screen the microbial communities, assess water quality, and identify potentially pathogenic groups.
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Affiliation(s)
- Benjamin H Gregson
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
| | - Alessia Bani
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
| | | | - Diane Holt
- Center for Enterprise and Entrepreneurship, Leeds University Business School, Leeds LS2 9JT, UK
| | - Corinne Whitby
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK.
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van de Velde CC, Joseph C, Biclot A, Huys GRB, Pinheiro VB, Bernaerts K, Raes J, Faust K. Fast quantification of gut bacterial species in cocultures using flow cytometry and supervised classification. ISME COMMUNICATIONS 2022; 2:40. [PMID: 37938658 PMCID: PMC9723706 DOI: 10.1038/s43705-022-00123-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 03/26/2022] [Accepted: 04/14/2022] [Indexed: 09/07/2023]
Abstract
A bottleneck for microbial community experiments with many samples and/or replicates is the fast quantification of individual taxon abundances, which is commonly achieved through sequencing marker genes such as the 16S rRNA gene. Here, we propose a new approach for high-throughput and high-quality enumeration of human gut bacteria in a defined community, combining flow cytometry and supervised classification to identify and quantify species mixed in silico and in defined communities in vitro. We identified species in a 5-species in silico community with an F1 score of 71%. In addition, we demonstrate in vitro that our method performs equally well or better than 16S rRNA gene sequencing in two-species cocultures and agrees with 16S rRNA gene sequencing data on the most abundant species in a four-species community. We found that shape and size differences alone are insufficient to distinguish species, and that it is thus necessary to exploit the multivariate nature of flow cytometry data. Finally, we observed that variability of flow cytometry data across replicates differs between gut bacterial species. In conclusion, the performance of supervised classification of gut species in flow cytometry data is species-dependent, but is for some combinations accurate enough to serve as a faster alternative to 16S rRNA gene sequencing.
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Affiliation(s)
- Charlotte C van de Velde
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Laboratory of Molecular Bacteriology, B-3000, Leuven, Belgium
| | - Clémence Joseph
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Laboratory of Molecular Bacteriology, B-3000, Leuven, Belgium
| | - Anaïs Biclot
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Laboratory of Molecular Bacteriology, B-3000, Leuven, Belgium
- VIB-KU Leuven, Center for Microbiology, B-3000, Leuven, Belgium
| | - Geert R B Huys
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Laboratory of Molecular Bacteriology, B-3000, Leuven, Belgium
- VIB-KU Leuven, Center for Microbiology, B-3000, Leuven, Belgium
| | - Vitor B Pinheiro
- KU Leuven, Department of Pharmaceutical and Pharmacological Sciences, Rega Institute for Medical Research, Medicinal Chemistry, B-3000, Leuven, Belgium
| | - Kristel Bernaerts
- KU Leuven, Department of Chemical Engineering, Chemical and Biochemical Reactor Engineering and Safety (CREaS), B-3001, Leuven, Belgium
| | - Jeroen Raes
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Laboratory of Molecular Bacteriology, B-3000, Leuven, Belgium
- VIB-KU Leuven, Center for Microbiology, B-3000, Leuven, Belgium
| | - Karoline Faust
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Laboratory of Molecular Bacteriology, B-3000, Leuven, Belgium.
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35
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Thom C, Smith CJ, Moore G, Weir P, Ijaz UZ. Microbiomes in drinking water treatment and distribution: A meta-analysis from source to tap. WATER RESEARCH 2022; 212:118106. [PMID: 35091225 DOI: 10.1016/j.watres.2022.118106] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 01/12/2022] [Accepted: 01/16/2022] [Indexed: 06/14/2023]
Abstract
A meta-analysis of existing and available Illumina 16S rRNA datasets from drinking water source, treatment and drinking water distribution systems (DWDS) were collated to compare changes in abundance and diversity throughout. Samples from bulk water and biofilm were used to assess principles governing microbial community assembly and the value of amplicon sequencing to water utilities. Individual phyla relationships were explored to identify competitive or synergistic factors governing DWDS microbiomes. The relative importance of stochasticity in the assembly of the DWDS microbiome was considered to identify the significance of source and treatment in determining communities in DWDS. Treatment of water significantly reduces overall species abundance and richness, with chlorination of water providing the most impact to individual taxa relationships. The assembly of microbial communities in the bulk water of the source, primary treatment process and DWDS is governed by more stochastic processes, as is the DWDS biofilm. DWDS biofilm is significantly different from bulk water in terms of local contribution to beta diversity, type and abundance of taxa present. Water immediately post chlorination has a more deterministic microbial assembly, highlighting the significance of this process in changing the microbiome, although elevated levels of stochasticity in DWDS samples suggest that this may not be the case at customer taps. 16S rRNA sequencing is becoming more routine, and may have several uses for water utilities, including: detection and risk assessment of potential pathogens such as those within the genera of Legionella and Mycobacterium; assessing the risk of nitrification in DWDS; providing improved indicators of process performance and monitoring for significant changes in the microbial community to detect contamination. Combining this with quantitative methods like flow cytometry will allow a greater depth of understanding of the DWDS microbiome.
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Affiliation(s)
- Claire Thom
- Infrastructure and Environment Research Division, James Watt School of Engineering, University of Glasgow, UK; Scottish Water, 6 Castle Drive Dunfermline, KY11 8GG, UK.
| | - Cindy J Smith
- Infrastructure and Environment Research Division, James Watt School of Engineering, University of Glasgow, UK
| | - Graeme Moore
- Scottish Water, 6 Castle Drive Dunfermline, KY11 8GG, UK
| | - Paul Weir
- Scottish Water, 6 Castle Drive Dunfermline, KY11 8GG, UK
| | - Umer Z Ijaz
- Infrastructure and Environment Research Division, James Watt School of Engineering, University of Glasgow, UK
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36
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Heins A, Hoang MD, Weuster‐Botz D. Advances in automated real-time flow cytometry for monitoring of bioreactor processes. Eng Life Sci 2022; 22:260-278. [PMID: 35382548 PMCID: PMC8961054 DOI: 10.1002/elsc.202100082] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 10/22/2021] [Accepted: 10/27/2021] [Indexed: 12/18/2022] Open
Abstract
Flow cytometry and its technological possibilities have greatly advanced in the past decade as analysis tool for single cell properties and population distributions of different cell types in bioreactors. Along the way, some solutions for automated real-time flow cytometry (ART-FCM) were developed for monitoring of bioreactor processes without operator interference over extended periods with variable sampling frequency. However, there is still great potential for ART-FCM to evolve and possibly become a standard application in bioprocess monitoring and process control. This review first addresses different components of an ART-FCM, including the sampling device, the sample-processing unit, the unit for sample delivery to the flow cytometer and the settings for measurement of pre-processed samples. Also, available algorithms are presented for automated data analysis of multi-parameter fluorescence datasets derived from ART-FCM experiments. Furthermore, challenges are discussed for integration of fluorescence-activated cell sorting into an ART-FCM setup for isolation and separation of interesting subpopulations that can be further characterized by for instance omics-methods. As the application of ART-FCM is especially of interest for bioreactor process monitoring, including investigation of population heterogeneity and automated process control, a summary of already existing setups for these purposes is given. Additionally, the general future potential of ART-FCM is addressed.
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Affiliation(s)
- Anna‐Lena Heins
- Institute of Biochemical EngineeringTechnical University of MunichGarchingGermany
| | - Manh Dat Hoang
- Institute of Biochemical EngineeringTechnical University of MunichGarchingGermany
| | - Dirk Weuster‐Botz
- Institute of Biochemical EngineeringTechnical University of MunichGarchingGermany
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37
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Ogundero A, Vignola M, Connelly S, Sloan WT. Validating Flow Cytometry as a Method for Quantifying Bdellovibrio Predatory Bacteria and Its Prey for Microbial Ecology. Microbiol Spectr 2022; 10:e0103321. [PMID: 35196816 PMCID: PMC8865432 DOI: 10.1128/spectrum.01033-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 01/31/2022] [Indexed: 12/19/2022] Open
Abstract
Bdellovibrio bacteriovorus is a predatory, Gram-negative bacteria that feeds on many pathogenic bacteria and has been investigated as a possible solution for mitigating biofilms in different fields. The application depends on more fundamental ecological studies into the dynamics between Bdellovibrio and their prey. To do so requires an accurate, reliable, and, preferably rapid, way of enumerating the cells. Flow cytometry (FCM) is potentially a rapid, accurate, and inexpensive tool for this, but it has yet to be validated in the enumeration of Bdellovibrio. In this study, we developed a protocol to measure the number of Bdellovibrio in samples of various densities using FCM and compared the results with those of other methods: optical density (OD), PFU assay (PFU), and quantitative PCR (qPCR). We observed a strong correlation between values obtained using FCM and PFU (ρ = 0.923) and FCM and qPCR (ρ = 0.987). Compared to optical density there was a much weaker correlation (ρ = 0.784), which was to be expected given the well-documented uncertainty in converting optical density (OD) to cell numbers. The FCM protocol was further validated by demonstrating its ability to distinguish and count mixed populations of Bdellovibrio and the prey Pseudomonas. Thus, the accuracy of FCM as well as its speed and reproducibility make it a suitable alternative for measuring Bdellovibrio cell numbers, especially where many samples are required to capture the dynamics of predator-prey interactions. IMPORTANCE The rise of antibiotic resistance and the unwanted growth of bacteria is a universally growing problem. Predatory bacteria can be used as a biological alternative to antibiotics because they grow by feeding on other bacteria. To apply this effectively requires further study and a deeper understanding of the forces that drive a prey population to elimination. Initially, such studies require more reliable methods to count these cells. Flow cytometry (FCM) is potentially a rapid, accurate, and inexpensive tool for this, but it has yet to be validated for predatory bacteria. This study develops a protocol to count the predatory bacteria Bdellovibrio bacteriovorus and its Pseudomonas prey using FCM and compare the results with those of other methods, demonstrating its ability for studies into B. bacteriovorus predation dynamics. This could lead to the use of B. bacteriovorus for killing bacterial biofilms in fields, such as drinking water and agriculture.
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Affiliation(s)
- Ayo Ogundero
- Infrastructure and Environment, School of Engineering, University of Glasgow, Glasgow, UK
| | - Marta Vignola
- Infrastructure and Environment, School of Engineering, University of Glasgow, Glasgow, UK
| | - Stephanie Connelly
- Infrastructure and Environment, School of Engineering, University of Glasgow, Glasgow, UK
| | - William T. Sloan
- Infrastructure and Environment, School of Engineering, University of Glasgow, Glasgow, UK
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Rogiers T, Merroun ML, Williamson A, Leys N, Houdt RV, Boon N, Mijnendonckx K. Cupriavidus metallidurans NA4 actively forms polyhydroxybutyrate-associated uranium-phosphate precipitates. JOURNAL OF HAZARDOUS MATERIALS 2022; 421:126737. [PMID: 34388922 DOI: 10.1016/j.jhazmat.2021.126737] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 07/21/2021] [Accepted: 07/22/2021] [Indexed: 06/13/2023]
Abstract
Cupriavidus metallidurans is a model bacterium to study molecular metal resistance mechanisms and its use for the bioremediation of several metals has been shown. However, its mechanisms for radionuclide resistance are unexplored. We investigated the interaction with uranium and associated cellular response to uranium for Cupriavidus metallidurans NA4. Strain NA4 actively captured 98 ± 1% of the uranium in its biomass after growing 24 h in the presence of 100 µM uranyl nitrate. TEM HAADF-EDX microscopy confirmed intracellular uranium-phosphate precipitates that were mainly associated with polyhydroxybutyrate. Furthermore, whole transcriptome sequencing indicated a complex transcriptional response with upregulation of genes encoding general stress-related proteins and several genes involved in metal resistance. More in particular, gene clusters known to be involved in copper and silver resistance were differentially expressed. This study provides further insights into bacterial interactions with and their response to uranium. Our results could be promising for uranium bioremediation purposes with the multi-metal resistant bacterium C. metallidurans NA4.
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Affiliation(s)
- Tom Rogiers
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium; Center for Microbial Ecology and Technology (CMET), UGent, Ghent, Belgium.
| | | | - Adam Williamson
- Center for Microbial Ecology and Technology (CMET), UGent, Ghent, Belgium.
| | - Natalie Leys
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium.
| | - Rob Van Houdt
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium.
| | - Nico Boon
- Center for Microbial Ecology and Technology (CMET), UGent, Ghent, Belgium.
| | - Kristel Mijnendonckx
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium.
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39
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Ntagia E, Chatzigiannidou I, Carvajal-Arroyo JM, Arends JBA, Rabaey K. Continuous H 2/CO 2 fermentation for acetic acid production under transient and continuous sulfide inhibition. CHEMOSPHERE 2021; 285:131536. [PMID: 34273695 DOI: 10.1016/j.chemosphere.2021.131536] [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: 03/31/2021] [Revised: 07/08/2021] [Accepted: 07/09/2021] [Indexed: 06/13/2023]
Abstract
Waste gas fermentation powered by renewable H2 is reaching kiloton scale. The presence of sulfide, inherent to many waste gases, can cause inhibition, requiring additional gas treatment. In this work, acetogenesis and methanogenesis inhibition by sulfide were studied in a 10-L mixed-culture fermenter, supplied with CO2 and connected with a water electrolysis unit for electricity-powered H2 supply. Three cycles of inhibition (1.3 mM total dissolved sulfide (TDS)) and recovery were applied, then the fermenter was operated at 0.5 mM TDS for 35 days. During operation at 0.5 mM TDS the acetate production rate reached 7.1 ± 1.5 mmol C L-1 d-1. Furthermore, 43.7 ± 15.6% of the electrons, provided as H2, were distributed to acetate and 7.7 ± 4.1% to butyrate, the second most abundant fermentation product. Selectivity of sulfide as inhibitor was demonstrated by a 7 days lag-phase of methanogenesis recovery, compared to 48 h for acetogenesis and by the less than 1% electrons distribution to CH4, under 0.5 mM TDS. The microbial community was dominated by Eubacterium, Proteiniphilum and an unclassified member of the Eggerthellaceae family. The taxonomic diversity of the community decreased and conversely the phenotypic diversity increased, during operation. This work illustrated the scale-up potential of waste gas fermentations, by elucidating the effect of sulfide as a common gas impurity, and by demonstrating continuous, potentially renewable supply of electrons.
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Affiliation(s)
- Eleftheria Ntagia
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000, Gent, Belgium; CAPTURE, www.capture-resources.be, Belgium
| | - Ioanna Chatzigiannidou
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000, Gent, Belgium
| | - Jose M Carvajal-Arroyo
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000, Gent, Belgium
| | - Jan B A Arends
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000, Gent, Belgium; CAPTURE, www.capture-resources.be, Belgium
| | - Korneel Rabaey
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000, Gent, Belgium; CAPTURE, www.capture-resources.be, Belgium.
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40
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Ott A, Quintela-Baluja M, Zealand AM, O'Donnell G, Haniffah MRM, Graham DW. Improved quantitative microbiome profiling for environmental antibiotic resistance surveillance. ENVIRONMENTAL MICROBIOME 2021; 16:21. [PMID: 34794510 PMCID: PMC8600772 DOI: 10.1186/s40793-021-00391-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 11/04/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Understanding environmental microbiomes and antibiotic resistance (AR) is hindered by over reliance on relative abundance data from next-generation sequencing. Relative data limits our ability to quantify changes in microbiomes and resistomes over space and time because sequencing depth is not considered and makes data less suitable for Quantitative Microbial Risk Assessments (QMRA), critical in quantifying environmental AR exposure and transmission risks. RESULTS Here we combine quantitative microbiome profiling (QMP; parallelization of amplicon sequencing and 16S rRNA qPCR to estimate cell counts) and absolute resistome profiling (based on high-throughput qPCR) to quantify AR along an anthropogenically impacted river. We show QMP overcomes biases caused by relative taxa abundance data and show the benefits of using unified Hill number diversities to describe environmental microbial communities. Our approach overcomes weaknesses in previous methods and shows Hill numbers are better for QMP in diversity characterisation. CONCLUSIONS Methods here can be adapted for any microbiome and resistome research question, but especially providing more quantitative data for QMRA and other environmental applications.
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Affiliation(s)
- Amelie Ott
- School of Engineering, Newcastle University, Cassie Building, Newcastle upon Tyne, NE1 7RU, UK
| | - Marcos Quintela-Baluja
- School of Engineering, Newcastle University, Cassie Building, Newcastle upon Tyne, NE1 7RU, UK
| | - Andrew M Zealand
- School of Engineering, Newcastle University, Cassie Building, Newcastle upon Tyne, NE1 7RU, UK
| | - Greg O'Donnell
- School of Engineering, Newcastle University, Cassie Building, Newcastle upon Tyne, NE1 7RU, UK
| | | | - David W Graham
- School of Engineering, Newcastle University, Cassie Building, Newcastle upon Tyne, NE1 7RU, UK.
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41
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Seller C, Özel Duygan BD, Honti M, Fenner K. Biotransformation of Chemicals at the Water–Sediment Interface─Toward a Robust Simulation Study Setup. ACS ENVIRONMENTAL AU 2021; 1:46-57. [PMID: 37101935 PMCID: PMC10114792 DOI: 10.1021/acsenvironau.1c00006] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Studying aquatic biotransformation of chemicals in laboratory experiments, i.e., OECD 308 and OECD 309 studies, is required by international regulatory frameworks to prevent the release of persistent chemicals into natural water bodies. Here, we aimed to address several previously described shortcomings of OECD 308/309 studies regarding their variable outcomes and questionable environmental relevance by broadly testing and characterizing a modified biotransformation test system in which an aerated water column covers a thin sediment layer. Compared to standard OECD 308/309 studies, the modified system showed little inter-replicate variability, improved observability of biotransformation, and consistency with first-order biotransformation kinetics for the majority of 43 test compounds, including pharmaceuticals, pesticides, and artificial sweeteners. To elucidate the factors underlying the decreased inter-replicate variability compared to OECD 309 outcomes, we used multidimensional flow cytometry data and a machine learning-based cell type assignment pipeline to study cell densities and cell type diversities in the sediment and water compartments. Our here presented data on cell type composition in both water and sediment allows, for the first time, to study the behavior of microbial test communities throughout different biotransformation simulation studies. We found that sediment-associated microbial communities were generally more stable throughout the experiments and exhibited higher cell type diversity than the water column-associated communities. Consistently, our data indicate that aquatic biotransformation of chemicals can be most robustly studied in test systems providing a sufficient amount of sediment-borne biomass. While these findings favor OECD 308-type systems over OECD 309-type systems to study biotransformation at the water-sediment interface, our results suggest that the former should be modified toward lower sediment-water ratios to improve observability and interpretability of biotransformation.
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Affiliation(s)
- Carolin Seller
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
- Department of Chemistry, University of Zürich, 8057 Zürich, Switzerland
| | - Birge D. Özel Duygan
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
- Institute of Microbiology, CHUV, 1011 Lausanne, Switzerland
- Department of Fundamental Microbiology, University of Lausanne, 1015 Lausanne, Switzerland
| | - Mark Honti
- MTA-BME Water Research Group, 1111 Budapest, Hungary
| | - Kathrin Fenner
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
- Department of Chemistry, University of Zürich, 8057 Zürich, Switzerland
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42
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Lam KN, Spanogiannopoulos P, Soto-Perez P, Alexander M, Nalley MJ, Bisanz JE, Nayak RR, Weakley AM, Yu FB, Turnbaugh PJ. Phage-delivered CRISPR-Cas9 for strain-specific depletion and genomic deletions in the gut microbiome. Cell Rep 2021; 37:109930. [PMID: 34731631 PMCID: PMC8591988 DOI: 10.1016/j.celrep.2021.109930] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/13/2021] [Accepted: 10/12/2021] [Indexed: 01/04/2023] Open
Abstract
Mechanistic insights into the role of the human microbiome in the predisposition to and treatment of disease are limited by the lack of methods to precisely add or remove microbial strains or genes from complex communities. Here, we demonstrate that engineered bacteriophage M13 can be used to deliver DNA to Escherichia coli within the mouse gastrointestinal (GI) tract. Delivery of a programmable exogenous CRISPR-Cas9 system enables the strain-specific depletion of fluorescently marked isogenic strains during competitive colonization and genomic deletions that encompass the target gene in mice colonized with a single strain. Multiple mechanisms allow E. coli to escape targeting, including loss of the CRISPR array or even the entire CRISPR-Cas9 system. These results provide a robust and experimentally tractable platform for microbiome editing, a foundation for the refinement of this approach to increase targeting efficiency, and a proof of concept for the extension to other phage-bacterial pairs of interest.
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Affiliation(s)
- Kathy N Lam
- Department of Microbiology & Immunology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Peter Spanogiannopoulos
- Department of Microbiology & Immunology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Paola Soto-Perez
- Department of Microbiology & Immunology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Margaret Alexander
- Department of Microbiology & Immunology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Matthew J Nalley
- Department of Microbiology & Immunology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Jordan E Bisanz
- Department of Microbiology & Immunology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Renuka R Nayak
- Department of Microbiology & Immunology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Allison M Weakley
- Chan-Zuckerberg Biohub, San Francisco, CA 94158, USA; Stanford ChEM-H: Chemistry, Engineering and Medicine for Human Health, Stanford University, Stanford, CA 94305, USA
| | - Feiqiao B Yu
- Chan-Zuckerberg Biohub, San Francisco, CA 94158, USA
| | - Peter J Turnbaugh
- Department of Microbiology & Immunology, University of California, San Francisco, San Francisco, CA 94143, USA; Chan-Zuckerberg Biohub, San Francisco, CA 94158, USA.
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43
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Predicting the Presence and Abundance of Bacterial Taxa in Environmental Communities through Flow Cytometric Fingerprinting. mSystems 2021; 6:e0055121. [PMID: 34546074 PMCID: PMC8547484 DOI: 10.1128/msystems.00551-21] [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] [Indexed: 11/30/2022] Open
Abstract
Microbiome management research and applications rely on temporally resolved measurements of community composition. Current technologies to assess community composition make use of either cultivation or sequencing of genomic material, which can become time-consuming and/or laborious in case high-throughput measurements are required. Here, using data from a shrimp hatchery as an economically relevant case study, we combined 16S rRNA gene amplicon sequencing and flow cytometry data to develop a computational workflow that allows the prediction of taxon abundances based on flow cytometry measurements. The first stage of our pipeline consists of a classifier to predict the presence or absence of the taxon of interest, with yielded an average accuracy of 88.13% ± 4.78% across the top 50 operational taxonomic units (OTUs) of our data set. In the second stage, this classifier was combined with a regression model to predict the relative abundances of the taxon of interest, which yielded an average R2 of 0.35 ± 0.24 across the top 50 OTUs of our data set. Application of the models to flow cytometry time series data showed that the generated models can predict the temporal dynamics of a large fraction of the investigated taxa. Using cell sorting, we validated that the model correctly associates taxa to regions in the cytometric fingerprint, where they are detected using 16S rRNA gene amplicon sequencing. Finally, we applied the approach of our pipeline to two other data sets of microbial ecosystems. This pipeline represents an addition to the expanding toolbox for flow cytometry-based monitoring of bacterial communities and complements the current plating- and marker gene-based methods. IMPORTANCE Monitoring of microbial community composition is crucial for both microbiome management research and applications. Existing technologies, such as plating and amplicon sequencing, can become laborious and expensive when high-throughput measurements are required. In recent years, flow cytometry-based measurements of community diversity have been shown to correlate well with those derived from 16S rRNA gene amplicon sequencing in several aquatic ecosystems, suggesting that there is a link between the taxonomic community composition and phenotypic properties as derived through flow cytometry. Here, we further integrated 16S rRNA gene amplicon sequencing and flow cytometry survey data in order to construct models that enable the prediction of both the presence and the abundances of individual bacterial taxa in mixed communities using flow cytometric fingerprinting. The developed pipeline holds great potential to be integrated into routine monitoring schemes and early warning systems for biotechnological applications.
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44
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Hong JK, Kim SB, Ahn SH, Choi Y, Lee TK. Flow cytometric monitoring of the bacterial phenotypic diversity in aquatic ecosystems. J Microbiol 2021; 59:879-885. [PMID: 34554452 DOI: 10.1007/s12275-021-1443-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 09/15/2021] [Accepted: 09/15/2021] [Indexed: 11/30/2022]
Abstract
Flow cytometry is a promising tool used to identify the phenotypic features of bacterial communities in aquatic ecosystems by measuring the physical and chemical properties of cells based on their light scattering behavior and fluorescence. Compared to molecular or culture-based approaches, flow cytometry is suitable for the online monitoring of microbial water quality because of its relatively simple sample preparation process, rapid analysis time, and high-resolution phenotypic data. Advanced statistical techniques (e.g., denoising and binning) can be utilized to successfully calculate phenotypic diversity by processing the scatter data obtained from flow cytometry. These phenotypic diversities were well correlated with taxonomic-based diversity computed using next-generation 16S RNA gene sequencing. The protocol provided in this paper should be a useful guide for a fast and reliable flow cytometric monitoring of bacterial phenotypic diversity in aquatic 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
| | - Seok Hyun Ahn
- Department of Environmental and Energy Engineering, Yonsei University, Wonju, 26493, Republic of Korea
| | - Yongjoo Choi
- Research Institute for Global Change, Japan Agency for Marine-Earth Science and Technology, Yokohama, 236-0001, Japan
| | - Tae Kwon Lee
- Department of Environmental and Energy Engineering, Yonsei University, Wonju, 26493, Republic of Korea.
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45
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De Vrieze J, Heyer R, Props R, Van Meulebroek L, Gille K, Vanhaecke L, Benndorf D, Boon N. Triangulation of microbial fingerprinting in anaerobic digestion reveals consistent fingerprinting profiles. WATER RESEARCH 2021; 202:117422. [PMID: 34280807 DOI: 10.1016/j.watres.2021.117422] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/01/2021] [Accepted: 07/07/2021] [Indexed: 06/13/2023]
Abstract
The anaerobic digestion microbiome has been puzzling us since the dawn of molecular methods for mixed microbial community analysis. Monitoring of the anaerobic digestion microbiome can either take place via a non-targeted holistic evaluation of the microbial community through fingerprinting or by targeted monitoring of selected taxa. Here, we compared four different microbial community fingerprinting methods, i.e., amplicon sequencing, metaproteomics, metabolomics and cytomics, in their ability to characterise the full-scale anaerobic digestion microbiome. Cytometric fingerprinting through cytomics reflects a, for anaerobic digestion, novel, single cell-based approach of direct microbial community fingerprinting by flow cytometry. Three different digester types, i.e., sludge digesters, digesters treating agro-industrial waste and dry anaerobic digesters, each reflected different operational parameters. The α-diversity analysis yielded inconsistent results, especially for richness, across the different methods. In contrast, β-diversity analysis resulted in comparable profiles, even when translated into phyla or functions, with clear separation of the three digester types. In-depth analysis of each method's features i.e., operational taxonomic units, metaproteins, metabolites, and cytometric traits, yielded certain similar features, yet, also some clear differences between the different methods, which was related to the complexity of the anaerobic digestion process. In conclusion, cytometric fingerprinting through flow cytometry is a reliable, fast method for holistic monitoring of the anaerobic digestion microbiome, and the complementary identification of key features through other methods could give rise to a direct interpretation of anaerobic digestion process performance.
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Affiliation(s)
- Jo De Vrieze
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, B-9000, Gent, Belgium; Division of Soil and Water Management, Department of Earth and Environmental sciences, KU Leuven, Kasteelpark Arenberg 20, PO box 2411, B-3001, Leuven, Belgium; Bio- and Chemical Systems Technology, Reactor Engineering and Safety (CREaS), Department of Chemical Engineering, KU Leuven, Celestijnenlaan 200F, PO box 2424, B-3001, Leuven, Belgium.
| | - Robert Heyer
- Bioprocess Engineering, Otto von Guericke University, Universitätsplatz 2, 39106, Magdeburg, Germany
| | - Ruben Props
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, B-9000, Gent, Belgium
| | - Lieven Van Meulebroek
- Laboratory of Chemical Analysis, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium
| | - Karen Gille
- Bioprocess Engineering, Otto von Guericke University, Universitätsplatz 2, 39106, Magdeburg, Germany
| | - Lynn Vanhaecke
- Laboratory of Chemical Analysis, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium
| | - Dirk Benndorf
- Bioprocess Engineering, Otto von Guericke University, Universitätsplatz 2, 39106, Magdeburg, Germany; Bioprocess Engineering, Max Planck Institute for Dynamics of Complex Technical Systems, Sandtorstraße 1, 39106, Magdeburg, Germany; Microbiology, Anhalt University of Applied Sciences, Bernburger Straße 55, 06354, Köthen, Germany
| | - Nico Boon
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, B-9000, Gent, Belgium
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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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Kerckhof FM, Sakarika M, Van Giel M, Muys M, Vermeir P, De Vrieze J, Vlaeminck SE, Rabaey K, Boon N. From Biogas and Hydrogen to Microbial Protein Through Co-Cultivation of Methane and Hydrogen Oxidizing Bacteria. Front Bioeng Biotechnol 2021; 9:733753. [PMID: 34527661 PMCID: PMC8435580 DOI: 10.3389/fbioe.2021.733753] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 08/13/2021] [Indexed: 01/23/2023] Open
Abstract
Increasing efforts are directed towards the development of sustainable alternative protein sources among which microbial protein (MP) is one of the most promising. Especially when waste streams are used as substrates, the case for MP could become environmentally favorable. The risks of using organic waste streams for MP production-the presence of pathogens or toxicants-can be mitigated by their anaerobic digestion and subsequent aerobic assimilation of the (filter-sterilized) biogas. Even though methane and hydrogen oxidizing bacteria (MOB and HOB) have been intensively studied for MP production, the potential benefits of their co-cultivation remain elusive. Here, we isolated a diverse group of novel HOB (that were capable of autotrophic metabolism), and co-cultured them with a defined set of MOB, which could be grown on a mixture of biogas and H2/O2. The combination of MOB and HOB, apart from the CH4 and CO2 contained in biogas, can also enable the valorization of the CO2 that results from the oxidation of methane by the MOB. Different MOB and HOB combinations were grown in serum vials to identify the best-performing ones. We observed synergistic effects on growth for several combinations, and in all combinations a co-culture consisting out of both HOB and MOB could be maintained during five days of cultivation. Relative to the axenic growth, five out of the ten co-cultures exhibited 1.1-3.8 times higher protein concentration and two combinations presented 2.4-6.1 times higher essential amino acid content. The MP produced in this study generally contained lower amounts of the essential amino acids histidine, lysine and threonine, compared to tofu and fishmeal. The most promising combination in terms of protein concentration and essential amino acid profile was Methyloparacoccus murrelli LMG 27482 with Cupriavidus necator LMG 1201. Microbial protein from M. murrelli and C. necator requires 27-67% less quantity than chicken, whole egg and tofu, while it only requires 15% more quantity than the amino acid-dense soybean to cover the needs of an average adult. In conclusion, while limitations still exist, the co-cultivation of MOB and HOB creates an alternative route for MP production leveraging safe and sustainably-produced gaseous substrates.
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Affiliation(s)
- Frederiek-Maarten Kerckhof
- Center for Microbial Ecology and Technology, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium
- Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Gent, Belgium
| | - Myrsini Sakarika
- Center for Microbial Ecology and Technology, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium
- Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Gent, Belgium
| | - Marie Van Giel
- Center for Microbial Ecology and Technology, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium
| | - Maarten Muys
- Research Group of Sustainable Energy, Air and Water Technology, Department of Bioscience Engineering, University of Antwerp, Antwerpen, Belgium
| | - Pieter Vermeir
- Laboratory of Chemical Analysis, Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Jo De Vrieze
- Center for Microbial Ecology and Technology, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium
| | - Siegfried E. Vlaeminck
- Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Gent, Belgium
- Research Group of Sustainable Energy, Air and Water Technology, Department of Bioscience Engineering, University of Antwerp, Antwerpen, Belgium
| | - Korneel Rabaey
- Center for Microbial Ecology and Technology, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium
- Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Gent, Belgium
| | - Nico Boon
- Center for Microbial Ecology and Technology, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium
- Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Gent, Belgium
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Minnebo Y, De Paepe K, Raes J, Van de Wiele T. Nutrient load acts as a driver of gut microbiota load, community composition and metabolic functionality in the simulator of the human intestinal microbial ecosystem. FEMS Microbiol Ecol 2021; 97:6329685. [PMID: 34320208 DOI: 10.1093/femsec/fiab111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 07/26/2021] [Indexed: 11/13/2022] Open
Abstract
A recently introduced quantitative framework for gut microbiota analysis indicated that microbial load alterations can be linked to various diseases, making it essential to pinpoint its determinants. We identified nutrient load as a main driver of the quantitative microbial community composition and functionality in vitro by stepwise decreasing standardised feed concentrations from 100% to 33, 20 and 10% in five-day intervals. While the proportional composition and metabolic profile were mainly determined by the inter-individual variability (35 and 41%), nutrient load accounted for 58%, 23% and 65% of the observed variation in the microbial load, quantitative composition and net daily metabolite production, respectively. After the tenfold nutrient reduction, the microbial load decreased by 79.72 ± 9% and 82.96 ± 1.66% in the proximal and distal colon, respectively, while the net total short-chain fatty acid production dropped by 79.42 ± 4.42% and 84.58 ± 2.42%, respectively. The majority of microbial taxa quantitatively decreased, whereas a select group of nutritional specialists, such as Akkermansia muciniphila and Bilophila wadsworthia and a number of opportunistic pathogens remained unaffected. This shows that nutrient load is an important driver of the human gut microbiome and should be considered in future in vitro and in vivo dietary research.
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Affiliation(s)
- Yorick Minnebo
- Center for Microbial Ecology and Technology, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Kim De Paepe
- Center for Microbial Ecology and Technology, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Jeroen Raes
- Laboratory of Molecular Bacteriology, Department of Microbiology and Immunology, KU Leuven, Herestraat 49, 3000 Leuven, Belgium.,Center for Microbiology, VIB, Herestraat 49, 3000 Leuven, Belgium
| | - Tom Van de Wiele
- Center for Microbial Ecology and Technology, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
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Ex and In Situ Reactivity and Sorption of Selenium in Opalinus Clay in the Presence of a Selenium Reducing Microbial Community. MINERALS 2021. [DOI: 10.3390/min11070757] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
79Se is a critical radionuclide concerning the safety of deep geological disposal of certain radioactive wastes in clay-rich formations. To study the fate of selenium oxyanions in clayey rocks in the presence of a selenium reducing microbial community, in situ tests were performed in the Opalinus Clay at the Mont Terri Rock Laboratory (Switzerland). Furthermore, biotic and abiotic batch tests were performed to assess Se(VI) and Se(IV) reactivity in the presence of Opalinus Clay and/or stainless steel, in order to support the interpretation of the in situ tests. Geochemical modeling was applied to simulate Se(VI) reduction, Se(IV) sorption and solubility, and diffusion processes. This study shows that microbial activity is required to transform Se(VI) into more reduced and sorbing Se species in the Opalinus Clay, while in abiotic conditions, Se(VI) remains unreactive. On the other hand, Se(IV) can be reduced by microorganisms but can also sorb in the presence of clay without microorganisms. In situ microbial reduction of Se oxyanions can occur with electron donors provided by the clay itself. If microorganisms would be active in the clay surrounding a disposal facility, microbial reduction of leached Se could thus contribute to the overall retention of Se in clayey host rocks.
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Alfredo K. The "Burn": water quality and microbiological impacts related to limited free chlorine disinfection periods in a chloramine system. WATER RESEARCH 2021; 197:117044. [PMID: 33799083 DOI: 10.1016/j.watres.2021.117044] [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: 11/02/2020] [Revised: 03/09/2021] [Accepted: 03/10/2021] [Indexed: 06/12/2023]
Abstract
To control microbial proliferation and nitrification within distribution systems, utilities practicing secondary disinfection chloramination often discontinue their ammonia feed and provide a short, free chlorine disinfection period (FClP), commonly referred to as a "chlorine burn". However, the success and practicality of this approach is often criticized because of the return to nitrification; yet, previous studies conducted in full-scale distribution systems do not contain the sampling frequency to determine how quickly nitrification can return. In this research, a total of 15 hydrants distributed across hydraulically modeled water ages were sampled for 21 sampling events over a period spanning two annual FClPs (2018 and 2019) to investigate the water quality, planktonic community, and, using a new sampling technique, established biofilm community impacts within a single, distribution system pressure zone. Hydrants measured elevated nitrite only 10 weeks after the end of the FClP and live cell counts in the bulk and scour samples statistically significantly increased within two weeks after the FClP ended and chloramine disinfection resumed, indicating limited impacts from a FClP. Furthermore, the FClP significantly increased iron concentrations during the period of free chlorine disinfection creating a consumer water quality concern. Microbial fingerprint analysis using flow cytometry revealed that beta diversity did not significantly change for sampling locations that experienced even periodic low total chlorine concentrations. Only locations that maintained high chlorine residuals throughout both chloramine and free chlorine disinfection periods demonstrated significant changes in bulk water microbial community. Even for these locations, microbial communities of the scoured biofilms remained similar over the course of the study.
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Affiliation(s)
- Katherine Alfredo
- Department of Civil and Environmental Engineering, University of South Florida, Tampa, FL.
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