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Ugolini GS, Wang M, Secchi E, Pioli R, Ackermann M, Stocker R. Microfluidic approaches in microbial ecology. Lab Chip 2024; 24:1394-1418. [PMID: 38344937 PMCID: PMC10898419 DOI: 10.1039/d3lc00784g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
Microbial life is at the heart of many diverse environments and regulates most natural processes, from the functioning of animal organs to the cycling of global carbon. Yet, the study of microbial ecology is often limited by challenges in visualizing microbial processes and replicating the environmental conditions under which they unfold. Microfluidics operates at the characteristic scale at which microorganisms live and perform their functions, thus allowing for the observation and quantification of behaviors such as growth, motility, and responses to external cues, often with greater detail than classical techniques. By enabling a high degree of control in space and time of environmental conditions such as nutrient gradients, pH levels, and fluid flow patterns, microfluidics further provides the opportunity to study microbial processes in conditions that mimic the natural settings harboring microbial life. In this review, we describe how recent applications of microfluidic systems to microbial ecology have enriched our understanding of microbial life and microbial communities. We highlight discoveries enabled by microfluidic approaches ranging from single-cell behaviors to the functioning of multi-cellular communities, and we indicate potential future opportunities to use microfluidics to further advance our understanding of microbial processes and their implications.
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Affiliation(s)
- Giovanni Stefano Ugolini
- Department of Civil, Environmental and Geomatic Engineering, Institute of Environmental Engineering, ETH Zurich, Laura-Hezner-Weg 7, 8093 Zurich, Switzerland.
| | - Miaoxiao Wang
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
- Department of Environmental Microbiology, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Duebendorf, Switzerland
| | - Eleonora Secchi
- Department of Civil, Environmental and Geomatic Engineering, Institute of Environmental Engineering, ETH Zurich, Laura-Hezner-Weg 7, 8093 Zurich, Switzerland.
| | - Roberto Pioli
- Department of Civil, Environmental and Geomatic Engineering, Institute of Environmental Engineering, ETH Zurich, Laura-Hezner-Weg 7, 8093 Zurich, Switzerland.
| | - Martin Ackermann
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
- Department of Environmental Microbiology, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Duebendorf, Switzerland
- Laboratory of Microbial Systems Ecology, School of Architecture, Civil and Environmental Engineering (ENAC), École Polytechnique Fédéral de Lausanne (EPFL), Lausanne, Switzerland
| | - Roman Stocker
- Department of Civil, Environmental and Geomatic Engineering, Institute of Environmental Engineering, ETH Zurich, Laura-Hezner-Weg 7, 8093 Zurich, Switzerland.
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2
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Miller IR, Bui H, Wood JB, Fields MW, Gerlach R. Understanding phycosomal dynamics to improve industrial microalgae cultivation. Trends Biotechnol 2024:S0167-7799(23)00342-6. [PMID: 38184438 DOI: 10.1016/j.tibtech.2023.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 12/06/2023] [Accepted: 12/06/2023] [Indexed: 01/08/2024]
Abstract
Algal-bacterial interactions are ubiquitous in both natural and industrial systems, and the characterization of these interactions has been reinvigorated by potential applications in biosystem productivity. Different growth conditions can be used for operational functions, such as the use of low-quality water or high pH/alkalinity, and the altered operating conditions likely constrain microbial community structure and function in unique ways. However, research is necessary to better understand whether consortia can be designed to improve the productivity, processing, and sustainability of industrial-scale cultivations through different controls that can constrain microbial interactions for maximal light-driven outputs. The review highlights current knowledge and gaps for relevant operating conditions, as well as suggestions for near-term and longer-term improvements for large-scale cultivation and polyculture engineering.
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Affiliation(s)
- Isaac R Miller
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA; Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA
| | - Huyen Bui
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA
| | - Jessica B Wood
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA; Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA
| | - Matthew W Fields
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA; Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA; Department of Civil Engineering, Montana State University, Bozeman, MT, USA; Energy Research Institute, Montana State University, Bozeman, MT, USA.
| | - Robin Gerlach
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA; Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA; Energy Research Institute, Montana State University, Bozeman, MT, USA; Department of Biological and Chemical Engineering, Bozeman, MT, USA
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3
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Clerc EE, Raina JB, Keegstra JM, Landry Z, Pontrelli S, Alcolombri U, Lambert BS, Anelli V, Vincent F, Masdeu-Navarro M, Sichert A, De Schaetzen F, Sauer U, Simó R, Hehemann JH, Vardi A, Seymour JR, Stocker R. Strong chemotaxis by marine bacteria towards polysaccharides is enhanced by the abundant organosulfur compound DMSP. Nat Commun 2023; 14:8080. [PMID: 38057294 DOI: 10.1038/s41467-023-43143-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 11/01/2023] [Indexed: 12/08/2023] Open
Abstract
The ability of marine bacteria to direct their movement in response to chemical gradients influences inter-species interactions, nutrient turnover, and ecosystem productivity. While many bacteria are chemotactic towards small metabolites, marine organic matter is predominantly composed of large molecules and polymers. Yet, the signalling role of these large molecules is largely unknown. Using in situ and laboratory-based chemotaxis assays, we show that marine bacteria are strongly attracted to the abundant algal polysaccharides laminarin and alginate. Unexpectedly, these polysaccharides elicited stronger chemoattraction than their oligo- and monosaccharide constituents. Furthermore, chemotaxis towards laminarin was strongly enhanced by dimethylsulfoniopropionate (DMSP), another ubiquitous algal-derived metabolite. Our results indicate that DMSP acts as a methyl donor for marine bacteria, increasing their gradient detection capacity and facilitating their access to polysaccharide patches. We demonstrate that marine bacteria are capable of strong chemotaxis towards large soluble polysaccharides and uncover a new ecological role for DMSP in enhancing this attraction. These navigation behaviours may contribute to the rapid turnover of polymers in the ocean, with important consequences for marine carbon cycling.
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Affiliation(s)
- Estelle E Clerc
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland
| | | | - Johannes M Keegstra
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland
| | - Zachary Landry
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland
| | - Sammy Pontrelli
- Institute of Molecular Systems Biology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Uria Alcolombri
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland
- Institute for Life Sciences, Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Bennett S Lambert
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland
| | - Valerio Anelli
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland
| | - Flora Vincent
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
- Developmental Biology Unit, European Molecular Biological Laboratory, Heidelberg, 69117, Germany
| | | | - Andreas Sichert
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Frédéric De Schaetzen
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland
| | - Uwe Sauer
- Institute of Molecular Systems Biology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Rafel Simó
- Institut de Ciències del Mar, CSIC, Barcelona, Catalonia, Spain
| | | | - Assaf Vardi
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Justin R Seymour
- Climate Change Cluster, University of Technology Sydney, Ultimo, Australia
| | - Roman Stocker
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland.
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4
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Stehnach MR, Henshaw RJ, Floge SA, Guasto JS. Multiplexed microfluidic screening of bacterial chemotaxis. eLife 2023; 12:e85348. [PMID: 37486823 PMCID: PMC10365836 DOI: 10.7554/elife.85348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Accepted: 06/15/2023] [Indexed: 07/26/2023] Open
Abstract
Microorganism sensing of and responding to ambient chemical gradients regulates a myriad of microbial processes that are fundamental to ecosystem function and human health and disease. The development of efficient, high-throughput screening tools for microbial chemotaxis is essential to disentangling the roles of diverse chemical compounds and concentrations that control cell nutrient uptake, chemorepulsion from toxins, and microbial pathogenesis. Here, we present a novel microfluidic multiplexed chemotaxis device (MCD) which uses serial dilution to simultaneously perform six parallel bacterial chemotaxis assays that span five orders of magnitude in chemostimulant concentration on a single chip. We first validated the dilution and gradient generation performance of the MCD, and then compared the measured chemotactic response of an established bacterial chemotaxis system (Vibrio alginolyticus) to a standard microfluidic assay. Next, the MCD's versatility was assessed by quantifying the chemotactic responses of different bacteria (Psuedoalteromonas haloplanktis, Escherichia coli) to different chemoattractants and chemorepellents. The MCD vastly accelerates the chemotactic screening process, which is critical to deciphering the complex sea of chemical stimuli underlying microbial responses.
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Affiliation(s)
- Michael R Stehnach
- Department of Mechanical Engineering, Tufts University, Medford, United States
| | - Richard J Henshaw
- Department of Mechanical Engineering, Tufts University, Medford, United States
| | - Sheri A Floge
- Department of Biology, Wake Forest University, Winston-Salem, United States
| | - Jeffrey S Guasto
- Department of Mechanical Engineering, Tufts University, Medford, United States
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5
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Ferguson C, Zhang Y, Palego C, Cheng X. Recent Approaches to Design and Analysis of Electrical Impedance Systems for Single Cells Using Machine Learning. Sensors (Basel) 2023; 23:5990. [PMID: 37447838 DOI: 10.3390/s23135990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 06/17/2023] [Accepted: 06/26/2023] [Indexed: 07/15/2023]
Abstract
Individual cells have many unique properties that can be quantified to develop a holistic understanding of a population. This can include understanding population characteristics, identifying subpopulations, or elucidating outlier characteristics that may be indicators of disease. Electrical impedance measurements are rapid and label-free for the monitoring of single cells and generate large datasets of many cells at single or multiple frequencies. To increase the accuracy and sensitivity of measurements and define the relationships between impedance and biological features, many electrical measurement systems have incorporated machine learning (ML) paradigms for control and analysis. Considering the difficulty capturing complex relationships using traditional modelling and statistical methods due to population heterogeneity, ML offers an exciting approach to the systemic collection and analysis of electrical properties in a data-driven way. In this work, we discuss incorporation of ML to improve the field of electrical single cell analysis by addressing the design challenges to manipulate single cells and sophisticated analysis of electrical properties that distinguish cellular changes. Looking forward, we emphasize the opportunity to build on integrated systems to address common challenges in data quality and generalizability to save time and resources at every step in electrical measurement of single cells.
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Affiliation(s)
- Caroline Ferguson
- Department of Bioengineering, Lehigh University, Bethlehem, PA 18015, USA
| | - Yu Zhang
- Department of Bioengineering, Lehigh University, Bethlehem, PA 18015, USA
| | - Cristiano Palego
- Department of Computer Science and Electronic Engineering, Bangor University, Bangor LL57 2DG, UK
| | - Xuanhong Cheng
- Department of Bioengineering, Lehigh University, Bethlehem, PA 18015, USA
- Department of Materials Science and Engineering, Lehigh University, Bethlehem, PA 18015, USA
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6
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Raina JB, Giardina M, Brumley DR, Clode PL, Pernice M, Guagliardo P, Bougoure J, Mendis H, Smriga S, Sonnenschein EC, Ullrich MS, Stocker R, Seymour JR. Chemotaxis increases metabolic exchanges between marine picophytoplankton and heterotrophic bacteria. Nat Microbiol 2023; 8:510-21. [PMID: 36759754 DOI: 10.1038/s41564-023-01327-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 01/09/2023] [Indexed: 02/11/2023]
Abstract
Behaviours such as chemotaxis can facilitate metabolic exchanges between phytoplankton and heterotrophic bacteria, which ultimately regulate oceanic productivity and biogeochemistry. However, numerically dominant picophytoplankton have been considered too small to be detected by chemotactic bacteria, implying that cell-cell interactions might not be possible between some of the most abundant organisms in the ocean. Here we examined how bacterial behaviour influences metabolic exchanges at the single-cell level between the ubiquitous picophytoplankton Synechococcus and the heterotrophic bacterium Marinobacter adhaerens, using bacterial mutants deficient in motility and chemotaxis. Stable-isotope tracking revealed that chemotaxis increased nitrogen and carbon uptake of both partners by up to 4.4-fold. A mathematical model following thousands of cells confirmed that short periods of exposure to small but nutrient-rich microenvironments surrounding Synechococcus cells provide a considerable competitive advantage to chemotactic bacteria. These findings reveal that transient interactions mediated by chemotaxis can underpin metabolic relationships among the ocean's most abundant microorganisms.
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7
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Hallstrøm S, Raina JB, Ostrowski M, Parks DH, Tyson GW, Hugenholtz P, Stocker R, Seymour JR, Riemann L. Chemotaxis may assist marine heterotrophic bacterial diazotrophs to find microzones suitable for N 2 fixation in the pelagic ocean. ISME J 2022; 16:2525-2534. [PMID: 35915168 PMCID: PMC9561647 DOI: 10.1038/s41396-022-01299-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 07/18/2022] [Accepted: 07/20/2022] [Indexed: 06/05/2023]
Abstract
Heterotrophic bacterial diazotrophs (HBDs) are ubiquitous in the pelagic ocean, where they have been predicted to carry out the anaerobic process of nitrogen fixation within low-oxygen microenvironments associated with marine pelagic particles. However, the mechanisms enabling particle colonization by HBDs are unknown. We hypothesized that HBDs use chemotaxis to locate and colonize suitable microenvironments, and showed that a cultivated marine HBD is chemotactic toward amino acids and phytoplankton-derived DOM. Using an in situ chemotaxis assay, we also discovered that diverse HBDs at a coastal site are motile and chemotactic toward DOM from various phytoplankton taxa and, indeed, that the proportion of diazotrophs was up to seven times higher among the motile fraction of the bacterial community compared to the bulk seawater community. Finally, three of four HBD isolates and 16 of 17 HBD metagenome assembled genomes, recovered from major ocean basins and locations along the Australian coast, each encoded >85% of proteins affiliated with the bacterial chemotaxis pathway. These results document the widespread capacity for chemotaxis in diverse and globally relevant marine HBDs. We suggest that HBDs could use chemotaxis to seek out and colonize low-oxygen microenvironments suitable for nitrogen fixation, such as those formed on marine particles. Chemotaxis in HBDs could therefore affect marine nitrogen and carbon biogeochemistry by facilitating nitrogen fixation within otherwise oxic waters, while also altering particle degradation and the efficiency of the biological pump.
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Affiliation(s)
- Søren Hallstrøm
- Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - Jean-Baptiste Raina
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Sydney, NSW, Australia
| | - Martin Ostrowski
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Sydney, NSW, Australia
| | - Donovan H Parks
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD, Australia
| | - Gene W Tyson
- Centre for Microbiome Research, School of Biomedical Science, Translational Research Institute, Queensland University of Technology, Woolloongabba, QLD, Australia
| | - Philip Hugenholtz
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD, Australia
| | - Roman Stocker
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland
| | - Justin R Seymour
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Sydney, NSW, Australia
| | - Lasse Riemann
- Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark.
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8
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Raina JB, Lambert BS, Parks DH, Rinke C, Siboni N, Bramucci A, Ostrowski M, Signal B, Lutz A, Mendis H, Rubino F, Fernandez VI, Stocker R, Hugenholtz P, Tyson GW, Seymour JR. Chemotaxis shapes the microscale organization of the ocean's microbiome. Nature 2022; 605:132-138. [PMID: 35444277 DOI: 10.1038/s41586-022-04614-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 03/04/2022] [Indexed: 01/04/2023]
Abstract
The capacity of planktonic marine microorganisms to actively seek out and exploit microscale chemical hotspots has been widely theorized to affect ocean-basin scale biogeochemistry1-3, but has never been examined comprehensively in situ among natural microbial communities. Here, using a field-based microfluidic platform to quantify the behavioural responses of marine bacteria and archaea, we observed significant levels of chemotaxis towards microscale hotspots of phytoplankton-derived dissolved organic matter (DOM) at a coastal field site across multiple deployments, spanning several months. Microscale metagenomics revealed that a wide diversity of marine prokaryotes, spanning 27 bacterial and 2 archaeal phyla, displayed chemotaxis towards microscale patches of DOM derived from ten globally distributed phytoplankton species. The distinct DOM composition of each phytoplankton species attracted phylogenetically and functionally discrete populations of bacteria and archaea, with 54% of chemotactic prokaryotes displaying highly specific responses to the DOM derived from only one or two phytoplankton species. Prokaryotes exhibiting chemotaxis towards phytoplankton-derived compounds were significantly enriched in the capacity to transport and metabolize specific phytoplankton-derived chemicals, and displayed enrichment in functions conducive to symbiotic relationships, including genes involved in the production of siderophores, B vitamins and growth-promoting hormones. Our findings demonstrate that the swimming behaviour of natural prokaryotic assemblages is governed by specific chemical cues, which dictate important biogeochemical transformation processes and the establishment of ecological interactions that structure the base of the marine food web.
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Affiliation(s)
- Jean-Baptiste Raina
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, New South Wales, Australia.
| | - Bennett S Lambert
- Ralph M. Parsons Laboratory, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.,Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, MA, USA.,Center for Environmental Genomics, School of Oceanography, University of Washington, Seattle, WA, USA.,Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland
| | - Donovan H Parks
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Christian Rinke
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Nachshon Siboni
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, New South Wales, Australia
| | - Anna Bramucci
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, New South Wales, Australia
| | - Martin Ostrowski
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, New South Wales, Australia
| | - Brandon Signal
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, New South Wales, Australia
| | - Adrian Lutz
- Metabolomics Australia, Bio21 Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - Himasha Mendis
- Metabolomics Australia, Bio21 Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - Francesco Rubino
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Vicente I Fernandez
- Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland
| | - Roman Stocker
- Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland
| | - Philip Hugenholtz
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Gene W Tyson
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia.,Centre for Microbiome Research, School of Biomedical Sciences, Translational Research Institute, Queensland University of Technology, Woolloongabba, Queensland, Australia
| | - Justin R Seymour
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, New South Wales, Australia.
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9
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Abstract
How bacterial chemotaxis is performed is much better understood than why. Traditionally, chemotaxis has been understood as a foraging strategy by which bacteria enhance their uptake of nutrients and energy, yet it has remained puzzling why certain less nutritious compounds are strong chemoattractants and vice versa. Recently, we have gained increased understanding of alternative ecological roles of chemotaxis, such as navigational guidance in colony expansion, localization of hosts or symbiotic partners and contribution to microbial diversity by the generation of spatial segregation in bacterial communities. Although bacterial chemotaxis has been observed in a wide range of environmental settings, insights into the phenomenon are mostly based on laboratory studies of model organisms. In this Review, we highlight how observing individual and collective migratory behaviour of bacteria in different settings informs the quantification of trade-offs, including between chemotaxis and growth. We argue that systematically mapping when and where bacteria are motile, in particular by transgenerational bacterial tracking in dynamic environments and in situ approaches from guts to oceans, will open the door to understanding the rich interplay between metabolism and growth and the contribution of chemotaxis to microbial life.
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Affiliation(s)
| | - Francesco Carrara
- Institute for Environmental Engineering, ETH Zurich, Zurich, Switzerland
| | - Roman Stocker
- Institute for Environmental Engineering, ETH Zurich, Zurich, Switzerland.
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10
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Larsson ME, Bramucci AR, Collins S, Hallegraeff G, Kahlke T, Raina JB, Seymour JR, Doblin MA. Mucospheres produced by a mixotrophic protist impact ocean carbon cycling. Nat Commun 2022; 13:1301. [PMID: 35288549 PMCID: PMC8921327 DOI: 10.1038/s41467-022-28867-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 02/04/2022] [Indexed: 01/04/2023] Open
Abstract
AbstractMixotrophic protists (unicellular eukaryotes) that engage in both phototrophy (photosynthesis) and phago-heterotrophy (engulfment of particles)—are predicted to contribute substantially to energy fluxes and marine biogeochemical cycles. However, their impact remains largely unquantified. Here we describe the sophisticated foraging strategy of a widespread mixotrophic dinoflagellate, involving the production of carbon-rich ‘mucospheres’ that attract, capture, and immobilise microbial prey facilitating their consumption. We provide a detailed characterisation of this previously undescribed behaviour and reveal that it represents an overlooked, yet quantitatively significant mechanism for oceanic carbon fluxes. Following feeding, the mucospheres laden with surplus prey are discarded and sink, contributing an estimated 0.17–1.24 mg m−2 d−1 of particulate organic carbon, or 0.02–0.15 Gt to the biological pump annually, which represents 0.1–0.7% of the estimated total export from the euphotic zone. These findings demonstrate how the complex foraging behaviour of a single species of mixotrophic protist can disproportionally contribute to the vertical flux of carbon in the ocean.
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11
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Kodera SM, Das P, Gilbert JA, Lutz HL. Conceptual strategies for characterizing interactions in microbial communities. iScience 2022; 25:103775. [PMID: 35146390 PMCID: PMC8819398 DOI: 10.1016/j.isci.2022.103775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Understanding the sets of inter- and intraspecies interactions in microbial communities is a fundamental goal of microbial ecology. However, the study and quantification of microbial interactions pose several challenges owing to their complexity, dynamic nature, and the sheer number of unique interactions within a typical community. To overcome such challenges, microbial ecologists must rely on various approaches to distill the system of study to a functional and conceptualizable level, allowing for a practical understanding of microbial interactions in both simplified and complex systems. This review broadly addresses the role of several conceptual approaches available for the microbial ecologist’s arsenal, examines specific tools used to accomplish such approaches, and describes how the assumptions, expectations, and philosophies underlying these tools change across scales of complexity.
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Affiliation(s)
- Sho M Kodera
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92037, USA
| | - Promi Das
- Center for Microbiome Innovation, University of California San Diego, La Jolla, CA 92093, USA.,Department of Pediatrics, University of California San Diego, La Jolla, CA 92161, USA
| | - Jack A Gilbert
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92037, USA.,Center for Microbiome Innovation, University of California San Diego, La Jolla, CA 92093, USA.,Department of Pediatrics, University of California San Diego, La Jolla, CA 92161, USA
| | - Holly L Lutz
- Center for Microbiome Innovation, University of California San Diego, La Jolla, CA 92093, USA.,Department of Pediatrics, University of California San Diego, La Jolla, CA 92161, USA.,Negaunee Integrative Collections Center, Field Museum of Natural History, Chicago, IL 60605, USA
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12
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Sun N, Jiang F, Zhang L, Feng G. Hyphal exudates of an arbuscular mycorrhizal fungus<italic>Rhizophagus irregularis</italic> induce phosphate-solubilizingbacterium <italic>Rahnella aquatilis</italic> to swim towards its hyphae. Chin Sci Bull 2021. [DOI: 10.1360/tb-2021-0579] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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13
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Jain A, Balmonte JP, Singh R, Bhaskar PV, Krishnan KP. Spatially resolved assembly, connectivity and structure of particle-associated and free-living bacterial communities in a high Arctic fjord. FEMS Microbiol Ecol 2021; 97:fiab139. [PMID: 34626180 PMCID: PMC8536490 DOI: 10.1093/femsec/fiab139] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 10/07/2021] [Indexed: 01/08/2023] Open
Abstract
The assembly processes that underlie the composition and connectivity of free-living (FL) and particle-associated (PA) bacterial communities from surface to deep waters remain little understood. Here, using phylogenetic null modeling, we quantify the relative influence of selective and stochastic mechanisms that assemble FL and PA bacterial communities throughout the water column in a high Arctic fjord. We demonstrate that assembly processes acting on FL and PA bacterial communities are similar in surface waters, but become increasingly distinct in deep waters. As depth increases, the relative influence of homogeneous selection increases for FL but decreases for PA communities. In addition, dispersal limitation and variable selection increase with depth for PA, but not for FL communities, indicating increased residence time of taxa on particles and less frequent decolonization. As a consequence, beta diversity of PA communities is greater in bottom than in surface waters. The limited connectivity between these communities with increasing depth leads to highly distinct FL and PA bacterial communities in bottom waters. Finally, depth-related trends for FL and PA beta diversity and connectivity in this study are consistent with previous observations in the open ocean, suggesting that assembly processes for FL and PA bacterial communities may also be distinct in other aquatic environments.
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Affiliation(s)
- Anand Jain
- Arctic Ecology and Biogeochemistry, National Centre for Polar and Ocean Research, Ministry of Earth Sciences, Vasco da Gama 403 804, Goa, India
| | - John Paul Balmonte
- Department of Ecology and Genetics, Uppsala University, Uppsala 752 36, Sweden
- HADAL and NordCEE, Department of Biology, University of Southern Denmark, Odense, 5230, Denmark
| | - Richa Singh
- Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi 221 005, Uttar Pradesh, India
| | - Parli Venkateswaran Bhaskar
- Ocean Science Group, National Centre for Polar and Ocean Research, Ministry of Earth Sciences, Vasco da Gama 403 804, Goa, India
| | - Kottekkatu Padinchati Krishnan
- Arctic Ecology and Biogeochemistry, National Centre for Polar and Ocean Research, Ministry of Earth Sciences, Vasco da Gama 403 804, Goa, India
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14
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Liu Y, Lehnert T, Gijs MAM. Effect of inoculum size and antibiotics on bacterial traveling bands in a thin microchannel defined by optical adhesive. Microsyst Nanoeng 2021; 7:86. [PMID: 34745645 PMCID: PMC8536744 DOI: 10.1038/s41378-021-00309-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 09/02/2021] [Accepted: 09/03/2021] [Indexed: 06/13/2023]
Abstract
Phenotypic diversity in bacterial flagella-induced motility leads to complex collective swimming patterns, appearing as traveling bands with transient locally enhanced cell densities. Traveling bands are known to be a bacterial chemotactic response to self-generated nutrient gradients during growth in resource-limited microenvironments. In this work, we studied different parameters of Escherichia coli (E. coli) collective migration, in particular the quantity of bacteria introduced initially in a microfluidic chip (inoculum size) and their exposure to antibiotics (ampicillin, ciprofloxacin, and gentamicin). We developed a hybrid polymer-glass chip with an intermediate optical adhesive layer featuring the microfluidic channel, enabling high-content imaging of the migration dynamics in a single bacterial layer, i.e., bacteria are confined in a quasi-2D space that is fully observable with a high-magnification microscope objective. On-chip bacterial motility and traveling band analysis was performed based on individual bacterial trajectories by means of custom-developed algorithms. Quantifications of swimming speed, tumble bias and effective diffusion properties allowed the assessment of phenotypic heterogeneity, resulting in variations in transient cell density distributions and swimming performance. We found that incubation of isogeneic E. coli with different inoculum sizes eventually generated different swimming phenotype distributions. Interestingly, incubation with antimicrobials promoted bacterial chemotaxis in specific cases, despite growth inhibition. Moreover, E. coli filamentation in the presence of antibiotics was assessed, and the impact on motility was evaluated. We propose that the observation of traveling bands can be explored as an alternative for fast antimicrobial susceptibility testing.
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Affiliation(s)
- Yang Liu
- Laboratory of Microsystems, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Thomas Lehnert
- Laboratory of Microsystems, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Martin A. M. Gijs
- Laboratory of Microsystems, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
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15
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Wong GCL, Antani JD, Lele PP, Chen J, Nan B, Kühn MJ, Persat A, Bru JL, Høyland-Kroghsbo NM, Siryaporn A, Conrad JC, Carrara F, Yawata Y, Stocker R, V Brun Y, Whitfield GB, Lee CK, de Anda J, Schmidt WC, Golestanian R, O'Toole GA, Floyd KA, Yildiz FH, Yang S, Jin F, Toyofuku M, Eberl L, Nomura N, Zacharoff LA, El-Naggar MY, Yalcin SE, Malvankar NS, Rojas-Andrade MD, Hochbaum AI, Yan J, Stone HA, Wingreen NS, Bassler BL, Wu Y, Xu H, Drescher K, Dunkel J. Roadmap on emerging concepts in the physical biology of bacterial biofilms: from surface sensing to community formation. Phys Biol 2021; 18. [PMID: 33462162 PMCID: PMC8506656 DOI: 10.1088/1478-3975/abdc0e] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 01/14/2021] [Indexed: 11/29/2022]
Abstract
Bacterial biofilms are communities of bacteria that exist as aggregates that can adhere to surfaces or be free-standing. This complex, social mode of cellular organization is fundamental to the physiology of microbes and often exhibits surprising behavior. Bacterial biofilms are more than the sum of their parts: single-cell behavior has a complex relation to collective community behavior, in a manner perhaps cognate to the complex relation between atomic physics and condensed matter physics. Biofilm microbiology is a relatively young field by biology standards, but it has already attracted intense attention from physicists. Sometimes, this attention takes the form of seeing biofilms as inspiration for new physics. In this roadmap, we highlight the work of those who have taken the opposite strategy: we highlight the work of physicists and physical scientists who use physics to engage fundamental concepts in bacterial biofilm microbiology, including adhesion, sensing, motility, signaling, memory, energy flow, community formation and cooperativity. These contributions are juxtaposed with microbiologists who have made recent important discoveries on bacterial biofilms using state-of-the-art physical methods. The contributions to this roadmap exemplify how well physics and biology can be combined to achieve a new synthesis, rather than just a division of labor.
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Affiliation(s)
- Gerard C L Wong
- Department of Bioengineering, University of California-Los Angeles, Los Angeles, California, CA 90095, United States of America.,Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California, CA 90095, United States of America.,California NanoSystems Institute, University of California-Los Angeles, Los Angeles, California, CA 90095, United States of America
| | - Jyot D Antani
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843, United States of America
| | - Pushkar P Lele
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843, United States of America
| | - Jing Chen
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA24061, United States of America
| | - Beiyan Nan
- Department of Biology, Texas A&M University, College Station, Texas, TX 77845, United States of America
| | - Marco J Kühn
- Institute of Bioengineering and Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Alexandre Persat
- Institute of Bioengineering and Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Jean-Louis Bru
- Department of Molecular Biology & Biochemistry, University of California-Irvine, California, CA 92697, United States of America
| | | | - Albert Siryaporn
- Department of Molecular Biology & Biochemistry, University of California-Irvine, California, CA 92697, United States of America.,Department of Physics & Astronomy, University of California-Irvine, California, CA 92697, United States of America
| | - Jacinta C Conrad
- William A Brookshire Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas, TX 77204, United States of America
| | - Francesco Carrara
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, 8093 Zurich, Switzerland
| | - Yutaka Yawata
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan.,Microbiology Research Center for Sustainability, University of Tsukuba, 305-8572 Tsukuba, Japan
| | - Roman Stocker
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, 8093 Zurich, Switzerland
| | - Yves V Brun
- University of Montreal, Faculty of Medicine, Montreal, Quebec, H3C 3J7, Canada
| | - Gregory B Whitfield
- University of Montreal, Faculty of Medicine, Montreal, Quebec, H3C 3J7, Canada
| | - Calvin K Lee
- Department of Bioengineering, University of California-Los Angeles, Los Angeles, California, CA 90095, United States of America.,Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California, CA 90095, United States of America.,California NanoSystems Institute, University of California-Los Angeles, Los Angeles, California, CA 90095, United States of America
| | - Jaime de Anda
- Department of Bioengineering, University of California-Los Angeles, Los Angeles, California, CA 90095, United States of America.,Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California, CA 90095, United States of America.,California NanoSystems Institute, University of California-Los Angeles, Los Angeles, California, CA 90095, United States of America
| | - William C Schmidt
- Department of Bioengineering, University of California-Los Angeles, Los Angeles, California, CA 90095, United States of America.,Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California, CA 90095, United States of America.,California NanoSystems Institute, University of California-Los Angeles, Los Angeles, California, CA 90095, United States of America
| | - Ramin Golestanian
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), D-37077 Göttingen, Germany.,Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford OX1 3PU, United Kingdom
| | - George A O'Toole
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, United States of America
| | - Kyle A Floyd
- Department of Microbiology and Environmental Toxicology, University of California-Santa Cruz, Santa Cruz, California, CA 95060, United States of America
| | - Fitnat H Yildiz
- Department of Microbiology and Environmental Toxicology, University of California-Santa Cruz, Santa Cruz, California, CA 95060, United States of America
| | - Shuai Yang
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, People's Republic of China
| | - Fan Jin
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, People's Republic of China
| | - Masanori Toyofuku
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan.,Microbiology Research Center for Sustainability, University of Tsukuba, 305-8572 Tsukuba, Japan
| | - Leo Eberl
- Department of Plant and Microbial Biology, University of Zürich, 8008 Zürich, Switzerland
| | - Nobuhiko Nomura
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan.,Microbiology Research Center for Sustainability, University of Tsukuba, 305-8572 Tsukuba, Japan
| | - Lori A Zacharoff
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California, CA 90089, United States of America.,Department of Chemistry, University of Southern California, Los Angeles, California, CA 90089, United States of America
| | - Mohamed Y El-Naggar
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California, CA 90089, United States of America.,Department of Chemistry, University of Southern California, Los Angeles, California, CA 90089, United States of America.,Department of Biological Sciences, University of Southern California, Los Angeles, California, CA 90089, United States of America
| | - Sibel Ebru Yalcin
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, CT 06516, United States of America.,Microbial Sciences Institute, Yale University, New Haven, Connecticut, CT 06516, United States of America
| | - Nikhil S Malvankar
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, CT 06516, United States of America.,Microbial Sciences Institute, Yale University, New Haven, Connecticut, CT 06516, United States of America
| | - Mauricio D Rojas-Andrade
- Department of Materials Science and Engineering, University of California-Irvine, Irvine, California CA 92697, United States of America
| | - Allon I Hochbaum
- Department of Molecular Biology & Biochemistry, University of California-Irvine, California, CA 92697, United States of America.,Department of Materials Science and Engineering, University of California-Irvine, Irvine, California CA 92697, United States of America.,Department of Chemistry, University of California-Irvine, Irvine, California, CA 92697, United States of America.,Department of Chemical and Biomolecular Engineering, University of California-Irvine, Irvine, California, CA 92697, United States of America
| | - Jing Yan
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut, CT 06511, United States of America
| | - Howard A Stone
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey, NJ 08544, United States of America
| | - Ned S Wingreen
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, NJ 08544, United States of America.,Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, NJ 08544, United States of America
| | - Bonnie L Bassler
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, NJ 08544, United States of America.,The Howard Hughes Medical Institute, Chevy Chase, Maryland MD 20815, United States of America
| | - Yilin Wu
- Department of Physics and Shenzhen Research Institute, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, People's Republic of China
| | - Haoran Xu
- Department of Physics and Shenzhen Research Institute, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, People's Republic of China
| | - Knut Drescher
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany.,Department of Physics, Philipps-Universität Marburg, 35043 Marburg, Germany
| | - Jörn Dunkel
- Department of Mathematics, Massachusetts Institute of Technology, Cambridge, Massachusetts, MA 02139-4307, United States of America
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16
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Weiland-Bräuer N. Friends or Foes-Microbial Interactions in Nature. Biology (Basel) 2021; 10:496. [PMID: 34199553 DOI: 10.3390/biology10060496] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 05/27/2021] [Accepted: 05/31/2021] [Indexed: 12/16/2022]
Abstract
Simple Summary Microorganisms like bacteria, archaea, fungi, microalgae, and viruses mostly form complex interactive networks within the ecosystem rather than existing as single planktonic cells. Interactions among microorganisms occur between the same species, with different species, or even among entirely different genera, families, or even domains. These interactions occur after environmental sensing, followed by converting those signals to molecular and genetic information, including many mechanisms and classes of molecules. Comprehensive studies on microbial interactions disclose key strategies of microbes to colonize and establish in a variety of different environments. Knowledge of the mechanisms involved in the microbial interactions is essential to understand the ecological impact of microbes and the development of dysbioses. It might be the key to exploit strategies and specific agents against different facing challenges, such as chronic and infectious diseases, hunger crisis, pollution, and sustainability. Abstract Microorganisms are present in nearly every niche on Earth and mainly do not exist solely but form communities of single or mixed species. Within such microbial populations and between the microbes and a eukaryotic host, various microbial interactions take place in an ever-changing environment. Those microbial interactions are crucial for a successful establishment and maintenance of a microbial population. The basic unit of interaction is the gene expression of each organism in this community in response to biotic or abiotic stimuli. Differential gene expression is responsible for producing exchangeable molecules involved in the interactions, ultimately leading to community behavior. Cooperative and competitive interactions within bacterial communities and between the associated bacteria and the host are the focus of this review, emphasizing microbial cell–cell communication (quorum sensing). Further, metagenomics is discussed as a helpful tool to analyze the complex genomic information of microbial communities and the functional role of different microbes within a community and to identify novel biomolecules for biotechnological applications.
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17
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Ruby E. Getting to know our microbial friends by dropping into their neighbourhood. Environ Microbiol Rep 2021; 13:27-30. [PMID: 33047473 DOI: 10.1111/1758-2229.12895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 10/08/2020] [Indexed: 06/11/2023]
Affiliation(s)
- Edward Ruby
- Kewalo Marine Laboratory, Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, HI, 96813, USA
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18
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Rahman I, Al-Bar AHA, Richard FS, Müller M, Mujahid A. Chemotactic response of Vibrio coralliilyticus to mucus from various coral species. Can J Microbiol 2021; 67:548-552. [PMID: 33417515 DOI: 10.1139/cjm-2020-0287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Vibrio coralliilyticus, a prominent pathogenic bacteria, is known to cause tissue damage in the coral Pocillopora damicornis and is attracted towards the coral via chemotaxis. However, the potential of V. coralliilyticus to infect most of the other coral hosts via chemotaxis is unknown. In this study, we used capillary assays to quantify the chemotactic response of V. coralliilyticus to the mucus of four tank-cultivated coral species (Cataphyllia jardine, Mussidae sp., Nemenzophyllia turbida, and Euphyllia ancora), and mucus from three wild coral species (Acropora sp., Porites sp., and Montipora sp.). The bacteria showed a positive chemotactic response to each coral mucus tested, with the highest response recorded to the mucus of Acropora sp. and the lowest response to the mucus of Montipora sp. A microfluidic chip was then used to assess the chemotactic preference of V. coralliilyticus to the mucus of the tank cultivated corals. Here too, the bacterium showed positive response, but with a slightly different ranking order. The strong chemotactic response of V. coralliilyticus towards the mucus tested could indicate a broader host range of V. coralliilyticus, and by extension, indicate a threat to weakened coral reefs worldwide.
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Affiliation(s)
- Ishraq Rahman
- Swinburne University of Technology Sarawak Campus, Jalan Simpang Tiga, 93350, Kuching, Malaysia
| | - Al-Hussain Ali Al-Bar
- Swinburne University of Technology Sarawak Campus, Jalan Simpang Tiga, 93350, Kuching, Malaysia
| | | | - Moritz Müller
- Swinburne University of Technology Sarawak Campus, Jalan Simpang Tiga, 93350, Kuching, Malaysia
| | - Aazani Mujahid
- Universiti Malaysia Sarawak, Jalan Datuk Mohammad Musa, 94300, Kota Samarahan, Sarawak
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19
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Abstract
Almost every ecosystem on this planet is teeming with microbial communities made of diverse bacterial species. At a reductionist view, many of these bacteria form pairwise interactions, but, as the field of view expands, the neighboring organisms and the abiotic environment can play a crucial role in shaping the interactions between species. Over the years, a strong foundation of knowledge has been built on isolated pairwise interactions between bacteria, but now the field is advancing toward understanding how cohabitating bacteria and natural surroundings affect these interactions. Use of bottom-up approaches, piecing communities together, and top-down approaches that deconstruct communities are providing insight on how different species interact. In this review, we highlight how studies are incorporating more complex communities, mimicking the natural environment, and recurring findings such as the importance of cooperation for stability in harsh environments and the impact of bacteria-induced environmental pH shifts. Additionally, we will discuss how omics are being used as a top-down approach to identify previously unknown interspecies bacterial interactions and the challenges of these types of studies for microbial ecology.
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Affiliation(s)
- Brittany N Ross
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
- Emory-Children's Cystic Fibrosis Center, Atlanta, Georgia, USA
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Marvin Whiteley
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
- Emory-Children's Cystic Fibrosis Center, Atlanta, Georgia, USA
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, Georgia, USA
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20
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Kolmeder CA, de Vos WM. Roadmap to functional characterization of the human intestinal microbiota in its interaction with the host. J Pharm Biomed Anal 2020; 194:113751. [PMID: 33328144 DOI: 10.1016/j.jpba.2020.113751] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 10/28/2020] [Accepted: 10/29/2020] [Indexed: 12/22/2022]
Abstract
It is known for more than 100 years that the intestinal microbes are important for the host's health and the last decade this is being intensely studied with a focus on the mechanistic aspects. Among the fundamental functions of the intestinal microbiome are the priming of the immune system, the production of essential vitamins and the energy harvest from foods. By now, several dozens of diseases, both intestinal and non-intestinal related, have been associated with the intestinal microbiome. Initially, this was based on the description of the composition between groups of different health status or treatment arms based on phylogenetic approaches based on the 16S rRNA gene sequences. This way of analysis has mostly moved to the analysis of all the genes or transcripts of the microbiome i.e. metagenomics and meta-transcriptomics. Differences are regularly found but these have to be taken with caution as we still do not know what the majority of genes of the intestinal microbiome are capable of doing. To circumvent this caveat researchers are studying the proteins and the metabolites of the microbiome and the host via metaproteomics and metabolomics approaches. However, also here the complexity is high and only a fraction of signals obtained with high throughput instruments can be identified and assigned to a known protein or molecule. Therefore, modern microbiome research needs advancement of existing and development of new analytical techniques. The usage of model systems like intestinal organoids where samples can be taken and processed rapidly as well as microfluidics systems may help. This review aims to elucidate what we know about the functionality of the human intestinal microbiome, what technologies are advancing this knowledge, and what innovations are still required to further evolve this actively developing field.
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Affiliation(s)
| | - Willem M de Vos
- Human Microbiome Research Program, Faculty of Medicine, University of Helsinki, Finland; Laboratory of Microbiology, Wageningen University, the Netherlands
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21
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Dabbagh SR, Rabbi F, Doğan Z, Yetisen AK, Tasoglu S. Machine learning-enabled multiplexed microfluidic sensors. Biomicrofluidics 2020; 14:061506. [PMID: 33343782 PMCID: PMC7733540 DOI: 10.1063/5.0025462] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Accepted: 12/01/2020] [Indexed: 05/02/2023]
Abstract
High-throughput, cost-effective, and portable devices can enhance the performance of point-of-care tests. Such devices are able to acquire images from samples at a high rate in combination with microfluidic chips in point-of-care applications. However, interpreting and analyzing the large amount of acquired data is not only a labor-intensive and time-consuming process, but also prone to the bias of the user and low accuracy. Integrating machine learning (ML) with the image acquisition capability of smartphones as well as increasing computing power could address the need for high-throughput, accurate, and automatized detection, data processing, and quantification of results. Here, ML-supported diagnostic technologies are presented. These technologies include quantification of colorimetric tests, classification of biological samples (cells and sperms), soft sensors, assay type detection, and recognition of the fluid properties. Challenges regarding the implementation of ML methods, including the required number of data points, image acquisition prerequisites, and execution of data-limited experiments are also discussed.
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Affiliation(s)
| | - Fazle Rabbi
- Department of Mechanical Engineering, Koç University, Sariyer, Istanbul 34450, Turkey
| | | | - Ali Kemal Yetisen
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, United Kingdom
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22
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Lee JY, Sadler NC, Egbert RG, Anderton CR, Hofmockel KS, Jansson JK, Song HS. Deep learning predicts microbial interactions from self-organized spatiotemporal patterns. Comput Struct Biotechnol J 2020; 18:1259-1269. [PMID: 32612750 PMCID: PMC7298420 DOI: 10.1016/j.csbj.2020.05.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 05/16/2020] [Accepted: 05/17/2020] [Indexed: 12/27/2022] Open
Abstract
Microbial communities organize into spatial patterns that are largely governed by interspecies interactions. This phenomenon is an important metric for understanding community functional dynamics, yet the use of spatial patterns for predicting microbial interactions is currently lacking. Here we propose supervised deep learning as a new tool for network inference. An agent-based model was used to simulate the spatiotemporal evolution of two interacting organisms under diverse growth and interaction scenarios, the data of which was subsequently used to train deep neural networks. For small-size domains (100 µm × 100 µm) over which interaction coefficients are assumed to be invariant, we obtained fairly accurate predictions, as indicated by an average R2 value of 0.84. In application to relatively larger domains (450 µm × 450 µm) where interaction coefficients are varying in space, deep learning models correctly predicted spatial distributions of interaction coefficients without any additional training. Lastly, we evaluated our model against real biological data obtained using Pseudomonas fluorescens and Escherichia coli co-cultures treated with polymeric chitin or N-acetylglucosamine, the hydrolysis product of chitin. While P. fluorescens can utilize both substrates for growth, E. coli lacked the ability to degrade chitin. Consistent with our expectations, our model predicted context-dependent interactions across two substrates, i.e., degrader-cheater relationship on chitin polymers and competition on monomers. The combined use of the agent-based model and machine learning algorithm successfully demonstrates how to infer microbial interactions from spatially distributed data, presenting itself as a useful tool for the analysis of more complex microbial community interactions.
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Affiliation(s)
- Joon-Yong Lee
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Natalie C. Sadler
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Robert G. Egbert
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Christopher R. Anderton
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Kirsten S. Hofmockel
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, USA
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA, USA
| | - Janet K. Jansson
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Hyun-Seob Song
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
- Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA
- Nebraska Food for Health Center, Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, NE, USA
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23
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Gurung JP, Gel M, Baker MAB. Microfluidic techniques for separation of bacterial cells via taxis. Microb Cell 2020; 7:66-79. [PMID: 32161767 PMCID: PMC7052948 DOI: 10.15698/mic2020.03.710] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 12/24/2019] [Accepted: 01/10/2020] [Indexed: 12/22/2022]
Abstract
The microbial environment is typically within a fluid and the key processes happen at the microscopic scale where viscosity dominates over inertial forces. Microfluidic tools are thus well suited to study microbial motility because they offer precise control of spatial structures and are ideal for the generation of laminar fluid flows with low Reynolds numbers at microbial lengthscales. These tools have been used in combination with microscopy platforms to visualise and study various microbial taxes. These include establishing concentration and temperature gradients to influence motility via chemotaxis and thermotaxis, or controlling the surrounding microenvironment to influence rheotaxis, magnetotaxis, and phototaxis. Improvements in microfluidic technology have allowed fine separation of cells based on subtle differences in motility traits and have applications in synthetic biology, directed evolution, and applied medical microbiology.
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Affiliation(s)
- Jyoti P. Gurung
- School of Biotechnology and Biomolecular Science, UNSW Sydney
| | - Murat Gel
- CSIRO Manufacturing, Clayton
- CSIRO Future Science Platform for Synthetic Biology
| | - Matthew A. B. Baker
- School of Biotechnology and Biomolecular Science, UNSW Sydney
- CSIRO Future Science Platform for Synthetic Biology
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Zengler K, Hofmockel K, Baliga NS, Behie SW, Bernstein HC, Brown JB, Dinneny JR, Floge SA, Forry SP, Hess M, Jackson SA, Jansson C, Lindemann SR, Pett-Ridge J, Maranas C, Venturelli OS, Wallenstein MD, Shank EA, Northen TR. EcoFABs: advancing microbiome science through standardized fabricated ecosystems. Nat Methods 2019; 16:567-571. [PMID: 31227812 PMCID: PMC6733021 DOI: 10.1038/s41592-019-0465-0] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Microbiomes play critical roles in ecosystems and human health, yet in most cases scientists lack standardized and reproducible model microbial communities. The development of fabricated microbial ecosystems, which we term EcoFABs, will provide such model systems for microbiome studies.
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Affiliation(s)
- Karsten Zengler
- Department of Pediatrics, University of California, San Diego, CA, USA
- Center for Microbiome Innovation, University of California, San Diego, CA, USA
| | - Kirsten Hofmockel
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, USA
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA, USA
| | - Nitin S Baliga
- Institute for Systems Biology, Seattle, WA, USA
- Departments of Microbiology and Biology, University of Washington, Seattle, WA, USA
- Molecular and Cellular Biology Program, University of Washington, Seattle, WA, USA
| | - Scott W Behie
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Hans C Bernstein
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
- The Norwegian College of Fishery Science and Arctic Centre for Sustainable Energy, UiT-The Arctic University of Norway, Tromsø, Norway
| | - James B Brown
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Centre for Computational Biology, School of Biosciences, University of Birmingham, Birmingham, UK
- Statistics Department, University of California, Berkeley, Berkeley, CA, USA
- Preminon, LLC, Antioch, CA, USA
| | - José R Dinneny
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Sheri A Floge
- Department of Microbiology, The Ohio State University, Columbus, OH, USA
- Department of Biology, Wake Forest University, Winston-Salem, NC, USA
| | - Samuel P Forry
- Biosystems and Biomaterials Division, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Matthias Hess
- Department of Animal Science, University of California, Davis, Davis, CA, USA
| | - Scott A Jackson
- Biosystems and Biomaterials Division, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Christer Jansson
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Stephen R Lindemann
- Whistler Center for Carbohydrate Research, Department of Food Science, Purdue University, West Lafayette, IN, USA
- Department of Nutrition Science, Purdue University, West Lafayette, IN, USA
| | - Jennifer Pett-Ridge
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Costas Maranas
- Department of Chemical Engineering, The Pennsylvania State University, University Park, PA, USA
| | | | - Matthew D Wallenstein
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO, USA
| | - Elizabeth A Shank
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Trent R Northen
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
- DOE Joint Genome Institute, Walnut Creek, CA, USA.
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25
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Li Y, Xuan J, Hu R, Zhang P, Lou X, Yang Y. Microfluidic triple-gradient generator for efficient screening of chemical space. Talanta 2019; 204:569-575. [PMID: 31357335 DOI: 10.1016/j.talanta.2019.06.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 05/27/2019] [Accepted: 06/06/2019] [Indexed: 12/22/2022]
Abstract
Generation of a combinatorial gradient for multiple chemicals is essential for studies of biochemical stimuli, chemoattraction, protein crystallization and others. While currently available platforms require complex design/settings to obtain a double-gradient chemical matrix, we herein report for the first time a simple triple-gradient matrix (TGM) device for efficient screening of chemical space. The TGM device is composed of two glass slides and works following the concept of SlipChip. The device utilizes XYZ space to distribute three chemicals and establishes a chemical gradient matrix within 5 min. The established matrix contains 24 or 104 screening conditions depending on the device used, which covers a concentration range of [0.117-1, 0.117-1 and 0.686-1] and [0.0830-1, 0.0830-1, 0.686-1] respectively for the three chemicals. With the triple gradients built simultaneously, this TGM device provides order-of-magnitude improvement in screening efficiency over existing single- or double-gradient generators. As a proof of concept, we applied the device to screen the crystallization conditions for two model proteins of lysozyme and trypsin and confirmed the crystal structures using X-ray diffraction. Furthermore, we successfully obtained the crystallization condition of adhesin competence repressor, a protein that senses the alterations in intracellular zinc concentrations. We expect the TGM system to be widely used as an analytical platform for material synthesis and chemical screening beyond for protein crystallization.
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Affiliation(s)
- Ying Li
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, Wuhan National Laboratory for Optoelectronics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, Hubei, 430071, China.
| | - Jie Xuan
- Chemistry and Biochemistry Department, Brigham Young University, Provo, UT 84602, USA
| | - Rui Hu
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, Wuhan National Laboratory for Optoelectronics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, Hubei, 430071, China
| | - Pengchao Zhang
- Houston Methodist Research Institute, Houston, TX, 77030, USA
| | - Xiaohua Lou
- Houston Methodist Research Institute, Houston, TX, 77030, USA
| | - Yunhuang Yang
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, Wuhan National Laboratory for Optoelectronics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, Hubei, 430071, China.
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26
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Chen D, Liu SJ, Du W. Chemotactic screening of imidazolinone-degrading bacteria by microfluidic SlipChip. J Hazard Mater 2019; 366:512-519. [PMID: 30562663 DOI: 10.1016/j.jhazmat.2018.12.029] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 11/19/2018] [Accepted: 12/10/2018] [Indexed: 06/09/2023]
Abstract
The group of imidazolinone herbicides, widely used for weed control, is hazardous to some sensitive rotational crops. Thus, rapid elimination of imidazolinones from contaminated soil is significant for the environment. Biodegradation studies have demonstrated the ability of chemotaxis to enhance the biodegradation of pollutants. In this study, we used our newly developed SlipChip device for chemotactic sorting and a microfluidic streak plate device for bacterial cultivation as a new pipeline for screening imidazolinone degraders. The degradation efficiencies of an enrichment consortium and a chemotaxis consortium were determined by HPLC-MS/MS. Both consortia degraded all tested imidazolinones, with the highest efficiency (71.8%) for imazethapyr, and the chemotaxis consortium degraded these compounds approximately 10% more efficiently than the enrichment consortium. Moreover, the community diversities of the enrichment consortium and the chemotaxis consortium were analyzed by 16S rRNA gene amplicon sequencing. The results indicated that members of genus Ochrobactrum primarily contribute to the degradation of imidazolinones. This work proved that chemotaxis toward biodegradable pollutants increases their bioavailability and enhances the biodegradation rate. It also provided a new way to screen effective pollutant degraders and can be applied for the selective isolation of other chemotactic species from environmental samples.
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Affiliation(s)
- Dongwei Chen
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Shuang-Jiang Liu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Wenbin Du
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Savaid Medical School, University of the Chinese Academy of Sciences, Beijing, 100049, China.
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27
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Roggo C, Carraro N, van der Meer JR. Probing chemotaxis activity in Escherichia coli using fluorescent protein fusions. Sci Rep 2019; 9:3845. [PMID: 30846802 DOI: 10.1038/s41598-019-40655-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 02/19/2019] [Indexed: 12/27/2022] Open
Abstract
Bacterial chemotaxis signaling may be interesting for the development of rapid biosensor assays, but is difficult to quantify. Here we explore two potential fluorescent readouts of chemotactically active Escherichia coli cells. In the first, we probed interactions between the chemotaxis signaling proteins CheY and CheZ by fusing them individually with non-fluorescent parts of stable or unstable ‘split’-Green Fluorescent Protein. Wild-type chemotactic cells but not mutants lacking the CheA kinase produced distinguishable fluorescence foci, two-thirds of which localize at the cell poles with the chemoreceptors and one-third at motor complexes. Fluorescent foci based on stable split-eGFP displayed small fluctuations in cells exposed to attractant or repellent, but those based on an unstable ASV-tagged eGFP showed a higher dynamic behaviour both in the foci intensity changes and the number of foci per cell. For the second readout, we expressed the pH-sensitive fluorophore pHluorin in the cyto- and periplasm of chemotactically active E. coli. Calibrations of pHluorin fluorescence as a function of pH demonstrated that cells accumulating near a chemo-attractant temporally increase cytoplasmic pH while decreasing periplasmic pH. Both readouts thus show promise for biosensor assays based on bacterial chemotaxis activity.
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Riordon J, Sovilj D, Sanner S, Sinton D, Young EW. Deep Learning with Microfluidics for Biotechnology. Trends Biotechnol 2019; 37:310-324. [DOI: 10.1016/j.tibtech.2018.08.005] [Citation(s) in RCA: 113] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 08/22/2018] [Accepted: 08/23/2018] [Indexed: 12/13/2022]
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Scheler O, Postek W, Garstecki P. Recent developments of microfluidics as a tool for biotechnology and microbiology. Curr Opin Biotechnol 2019; 55:60-67. [DOI: 10.1016/j.copbio.2018.08.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 07/13/2018] [Accepted: 08/09/2018] [Indexed: 02/07/2023]
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von Hoven G, Neukirch C, Meyenburg M, Schmidt S, Vences A, Osorio CR, Husmann M, Rivas AJ. Cytotoxin- and Chemotaxis-Genes Cooperate to Promote Adhesion of Photobacterium damselae subsp. damselae. Front Microbiol 2019; 9:2996. [PMID: 30619115 PMCID: PMC6300472 DOI: 10.3389/fmicb.2018.02996] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 11/20/2018] [Indexed: 12/21/2022] Open
Abstract
Photobacterium damselae subsp. damselae (Pdd) is an emerging pathogen of marine animals that sometimes causes serious infections in humans. Two related pore forming toxins, phobalysins P and C, and damselysin, a phospholipase D, confer strong virulence of Pdd in mice. Because infections by Pdd are typically caused following exposure of wounds to sea water we investigated how salinity impacts toxin activity, swimming, and association of Pdd with epithelial cells. These activities were low when bacteria were pre-cultured in media with 3.5% NaCl, the global average salinity of sea water. In contrast, lower salinity increased swimming of wild type Pdd peaking at 2% NaCl, hemolysis, and association with epithelial cells peaking at 1-1.5%. Previously, we have found that hemolysin genes enhance the association of Pdd with epithelial cells, but the underlying mechanisms have remained ill-defined. We here searched for potential links between hemolysin-production, chemotaxis and association of Pdd with target cells at varying salt concentrations. Unexpectedly, disruption of chemotaxis regulator cheA not only affected bacterial swimming and association with epithelial cells at intermediate to low salinity, but also reduced the production of plasmid-encoded phobalysin (PhlyP). The results thus reveal unforeseen links between chemotaxis regulators, a pore forming toxin and the association of a marine bacterium with target cells.
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Affiliation(s)
- Gisela von Hoven
- Institute of Medical Microbiology and Hygiene, University Medical Center, Johannes Gutenberg University, Mainz, Germany
| | - Claudia Neukirch
- Institute of Medical Microbiology and Hygiene, University Medical Center, Johannes Gutenberg University, Mainz, Germany
| | - Martina Meyenburg
- Institute of Medical Microbiology and Hygiene, University Medical Center, Johannes Gutenberg University, Mainz, Germany
| | - Sabine Schmidt
- Institute of Medical Microbiology and Hygiene, University Medical Center, Johannes Gutenberg University, Mainz, Germany
| | - Ana Vences
- Departamento de Microbioloxìa e Parasitoloxìa, Instituto de Acuicultura, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Carlos R Osorio
- Departamento de Microbioloxìa e Parasitoloxìa, Instituto de Acuicultura, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Matthias Husmann
- Institute of Medical Microbiology and Hygiene, University Medical Center, Johannes Gutenberg University, Mainz, Germany
| | - Amable J Rivas
- Institute of Medical Microbiology and Hygiene, University Medical Center, Johannes Gutenberg University, Mainz, Germany
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Roggo C, Clerc EE, Hadadi N, Carraro N, Stocker R, van der Meer JR. Heterologous Expression of Pseudomonas putida Methyl-Accepting Chemotaxis Proteins Yields Escherichia coli Cells Chemotactic to Aromatic Compounds. Appl Environ Microbiol 2018; 84:e01362-18. [PMID: 30006400 DOI: 10.1128/AEM.01362-18] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 07/05/2018] [Indexed: 12/17/2022] Open
Abstract
Escherichia coli, commonly used in chemotaxis studies, is attracted mostly by amino acids, sugars, and peptides. We envisioned modifying the chemotaxis specificity of E. coli by expressing heterologous chemoreceptors from Pseudomonas putida enabling attraction either to toluene or benzoate. The mcpT gene encoding the type 40-helical bundle (40H) methyl-accepting chemoreceptor for toluene from Pseudomonas putida MT53 and the pcaY gene for the type 40H receptor for benzoate and related molecules from P. putida F1 were expressed from the trg promoter on a plasmid in motile wild-type E. coli MG1655. E. coli cells expressing McpT accumulated in chemoattraction assays to sources with 60 to 200 μM toluene, although less strongly than the response to 100 μM serine, but statistically significantly stronger than that to sources without any added attractant. An McpT-mCherry fusion protein was detectably expressed in E. coli and yielded weak but distinguishable membranes and polar foci in 1% of cells. E. coli cells expressing PcaY showed weak attraction to 0.1 to 1 mM benzoate, but 50 to 70% of cells localized the PcaY-mCherry fusion to their membrane. We conclude that implementing heterologous receptors in the E. coli chemotaxis network is possible and, upon improvement of the compatibility of the type 40H chemoreceptors, may bear interest for biosensing.IMPORTANCE Bacterial chemotaxis might be harnessed for the development of rapid biosensors, in which chemical availability is deduced from cell accumulation to chemoattractants over time. Chemotaxis of Escherichia coli has been well studied, but the bacterium is not attracted to chemicals of environmental concern, such as aromatic solvents. We show here that heterologous chemoreceptors for aromatic compounds from Pseudomonas putida at least partly functionally complement the E. coli chemotaxis network, yielding cells attracted to toluene or benzoate. Complementation was still inferior to native chemoattractants, like serine, but our study demonstrates the potential for obtaining selective sensing for aromatic compounds in E. coli.
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Abstract
There are more than one million microbial cells in every drop of seawater, and their collective metabolisms not only recycle nutrients that can then be used by larger organisms but also catalyze key chemical transformations that maintain Earth’s habitability. Understanding how these microbes interact with each other and with multicellular hosts is critical to reliably quantify any functional aspect of their metabolisms and to predicting their outcomes on larger scales. There are more than one million microbial cells in every drop of seawater, and their collective metabolisms not only recycle nutrients that can then be used by larger organisms but also catalyze key chemical transformations that maintain Earth’s habitability. Understanding how these microbes interact with each other and with multicellular hosts is critical to reliably quantify any functional aspect of their metabolisms and to predict their outcomes on larger scales. Following a large body of literature pioneered by Farooq Azam and colleagues more than 30 years ago, I emphasize the importance of studying microbial interactions at the appropriate scale if we want to fully decipher the roles that they play in oceanic ecosystems.
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Karbalaei A, Cho HJ. Microfluidic Devices Developed for and Inspired by Thermotaxis and Chemotaxis. Micromachines (Basel) 2018; 9:E149. [PMID: 30424083 PMCID: PMC6187570 DOI: 10.3390/mi9040149] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 03/07/2018] [Accepted: 03/22/2018] [Indexed: 01/08/2023]
Abstract
Taxis has been reported in many cells and microorganisms, due to their tendency to migrate toward favorable physical situations and avoid damage and death. Thermotaxis and chemotaxis are two of the major types of taxis that naturally occur on a daily basis. Understanding the details of the thermo- and chemotactic behavioral response of cells and microorganisms is necessary to reveal the body function, diagnosing diseases and developing therapeutic treatments. Considering the length-scale and range of effectiveness of these phenomena, advances in microfluidics have facilitated taxis experiments and enhanced the precision of controlling and capturing microscale samples. Microfabrication of fluidic chips could bridge the gap between in vitro and in situ biological assays, specifically in taxis experiments. Numerous efforts have been made to develop, fabricate and implement novel microchips to conduct taxis experiments and increase the accuracy of the results. The concepts originated from thermo- and chemotaxis, inspired novel ideas applicable to microfluidics as well, more specifically, thermocapillarity and chemocapillarity (or solutocapillarity) for the manipulation of single- and multi-phase fluid flows in microscale and fluidic control elements such as valves, pumps, mixers, traps, etc. This paper starts with a brief biological overview of the concept of thermo- and chemotaxis followed by the most recent developments in microchips used for thermo- and chemotaxis experiments. The last section of this review focuses on the microfluidic devices inspired by the concept of thermo- and chemotaxis. Various microfluidic devices that have either been used for, or inspired by thermo- and chemotaxis are reviewed categorically.
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Affiliation(s)
- Alireza Karbalaei
- Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, FL 32816, USA.
| | - Hyoung Jin Cho
- Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, FL 32816, USA.
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Nagy K, Ábrahám Á, Keymer JE, Galajda P. Application of Microfluidics in Experimental Ecology: The Importance of Being Spatial. Front Microbiol 2018; 9:496. [PMID: 29616009 PMCID: PMC5870036 DOI: 10.3389/fmicb.2018.00496] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 03/02/2018] [Indexed: 12/21/2022] Open
Abstract
Microfluidics is an emerging technology that is used more and more in biology experiments. Its capabilities of creating precisely controlled conditions in cellular dimensions make it ideal to explore cell-cell and cell-environment interactions. Thus, a wide spectrum of problems in microbial ecology can be studied using engineered microbial habitats. Moreover, artificial microfluidic ecosystems can serve as model systems to test ecology theories and principles that apply on a higher level in the hierarchy of biological organization. In this mini review we aim to demonstrate the versatility of microfluidics and the diversity of its applications that help the advance of microbiology, and in more general, experimental ecology.
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Affiliation(s)
- Krisztina Nagy
- Biological Research Centre, Institute of Biophysics, Hungarian Academy of Sciences, Szeged, Hungary
| | - Ágnes Ábrahám
- Biological Research Centre, Institute of Biophysics, Hungarian Academy of Sciences, Szeged, Hungary
- Doctoral School of Multidisciplinary Medical Science, University of Szeged, Szeged, Hungary
| | - Juan E. Keymer
- School of Biological Sciences and School of Physics, Pontifical Catholic University of Chile, Santiago, Chile
| | - Péter Galajda
- Biological Research Centre, Institute of Biophysics, Hungarian Academy of Sciences, Szeged, Hungary
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Abstract
The concept of symbiosis – defined in 1879 by de Bary as ‘the living together of unlike organisms’ – has a rich and convoluted history in biology. In part, because it questioned the concept of the individual, symbiosis fell largely outside mainstream science and has traditionally received less attention than other research disciplines. This is gradually changing. In nature organisms do not live in isolation but rather interact with, and are impacted by, diverse beings throughout their life histories. Symbiosis is now recognized as a central driver of evolution across the entire tree of life, including, for example, bacterial endosymbionts that provide insects with vital nutrients and the mitochondria that power our own cells. Symbioses between microbes and their multicellular hosts also underpin the ecological success of some of the most productive ecosystems on the planet, including hydrothermal vents and coral reefs. In November 2017, scientists working in fields spanning the life sciences came together at a Company of Biologists’ workshop to discuss the origin, maintenance, and long-term implications of symbiosis from the complementary perspectives of cell biology, ecology, evolution and genomics, taking into account both model and non-model organisms. Here, we provide a brief synthesis of the fruitful discussions that transpired. Summary: At a recent Company of Biologists workshop, evolutionary biologists discussed the major outstanding questions in symbiosis research.
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Affiliation(s)
- Jean-Baptiste Raina
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Laura Eme
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, SE-75123, Uppsala, Sweden
| | - F Joseph Pollock
- Eberly College of Science, Department of Biology, Pennsylvania State University, University Park, PA 16801, USA
| | - Anja Spang
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, SE-75123, Uppsala, Sweden.,NIOZ, Royal Netherlands Institute for Sea Research, Department of Marine Microbiology and Biogeochemistry, and Utrecht University, P.O. Box 59, NL-1790 AB Den Burg, The Netherlands
| | - John M Archibald
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS, B3H 4R2, Canada
| | - Tom A Williams
- School of Biological Sciences, University of Bristol, 24 Tyndall Ave, Bristol, BS8 1TH, UK
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Abstract
Like many organisms, bacteria regularly inhabit environments characterised by spatiotemporal heterogeneity in the availability of resources required for growth and energy generation, meaning they must either tune their metabolism to prevailing conditions or have the capacity to migrate to favourable microenvironments1. To achieve the latter, bacteria measure their resource landscape and suitably direct their locomotion using a behaviour called chemotaxis, which is the ability to guide movement up or down chemical gradients. The capacity to perform chemotaxis is widespread across the bacterial domain, although most of our understanding of this phenotype is derived from enteric bacteria2,3. In the ocean, marine bacteria are often motile4, and in fact capable of much higher swimming speeds5 and chemotactic precision6 than these enteric models for chemotaxis2. Here we discuss the underlying motives and purposes for bacterial chemotaxis in the ocean, by noting that marine bacteria experience a surprisingly heterogeneous chemical seascape7,8, whereby chemotaxis can provide substantial fitness advantages and even influence large-scale processes including marine ecosystem productivity, biogeochemical cycling and disease.
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