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Wang M, Wang S, Li H, Mao Z, Lu Y, Cheng Y, Han X, Wang Y, Liu Y, Wan S, Zhou LJ, Wu QL. Methylparaben changes the community composition, structure, and assembly processes of free-living bacteria, phytoplankton, and zooplankton. ENVIRONMENTAL RESEARCH 2024; 262:119944. [PMID: 39245310 DOI: 10.1016/j.envres.2024.119944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2024] [Revised: 08/31/2024] [Accepted: 09/05/2024] [Indexed: 09/10/2024]
Abstract
Parabens are common contaminants in river and lake environments. However, few studies have been conducted to determine the effects of parabens on bacteria, phytoplankton, and zooplankton communities in aquatic environments. In this study, the effect of methylparaben (MP) on the diversity and community structure of the aquatic plankton microbiome was investigated by incubating a microcosm with MP at 0.1, 1, 10, and 100 μg/L for 7 days. The results of the Simpson index showed that MP treatment altered the α-diversity of free-living bacteria (FL), phytoplankton, and zooplankton but had no significant effect on the α-diversity of particle-attached bacteria (PA). Further, the relative abundances of the sensitive bacteria Chitinophaga and Vibrionimonas declined after MP addition. Moreover, the relative abundances of Desmodesmus sp. HSJ717 and Scenedesmus armatus, of the phylum Chlorophyta, were significantly lower in the MP treatment group than in the control group. In addition, the relative abundance of Stoeckeria sp. SSMS0806, of the Dinophyta phylum, was higher than that in the control group. MP addition also increased the relative abundance of Arthropoda but decreased the relative abundance of Rotifera and Ciliophora. The β-diversity analysis showed that FL and phytoplankton communities were clustered separately after treatment with different MP concentrations. MP addition changed community assembly mechanisms in the microcosm, including increasing the stochastic processes for FL and the deterministic processes for PA and phytoplankton. Structural equation modeling analysis showed a significant negative relationship between bacteria richness and phytoplankton richness, and a significant positive relationship between phytoplankton (richness and community composition) and zooplankton. Overall, this study emphasizes that MP, at environmental concentrations, can change the diversity and structure of plankton microbial communities, which might have a negative effect on ecological systems.
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Affiliation(s)
- Man Wang
- School of Life Sciences, Institute of Life Science and Green Development, Hebei University, Baoding, 071002, China; Key Laboratory of Lake and Watershed Science for Water Security, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Shengxing Wang
- School of Life Sciences, Institute of Life Science and Green Development, Hebei University, Baoding, 071002, China; Key Laboratory of Lake and Watershed Science for Water Security, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Huabing Li
- Key Laboratory of Lake and Watershed Science for Water Security, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Zhendu Mao
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; Center for Evolution and Conservation Biology, Southern Marine Sciences and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China
| | - Yiwei Lu
- School of Life Sciences, Institute of Life Science and Green Development, Hebei University, Baoding, 071002, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; College of Food Science and Technology, Hebei Agricultural University, Baoding, 071001, China
| | - Yunshan Cheng
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; School of Ecology and Environment, Anhui Normal University, Wuhu, 050031, China
| | - Xiaotong Han
- School of Life Sciences, Institute of Life Science and Green Development, Hebei University, Baoding, 071002, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Yujing Wang
- Key Laboratory of Lake and Watershed Science for Water Security, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Yanru Liu
- School of Life Sciences, Institute of Life Science and Green Development, Hebei University, Baoding, 071002, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Shiqiang Wan
- School of Life Sciences, Institute of Life Science and Green Development, Hebei University, Baoding, 071002, China
| | - Li-Jun Zhou
- Key Laboratory of Lake and Watershed Science for Water Security, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China.
| | - Qinglong L Wu
- Key Laboratory of Lake and Watershed Science for Water Security, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; Center for Evolution and Conservation Biology, Southern Marine Sciences and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China.
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2
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Stehnach MR, Henshaw RJ, Floge SA, Guasto JS. Multiplexed Microfluidic Platform for Parallel Bacterial Chemotaxis Assays. Bio Protoc 2024; 14:e5062. [PMID: 39282234 PMCID: PMC11393045 DOI: 10.21769/bioprotoc.5062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 07/28/2024] [Accepted: 07/30/2024] [Indexed: 09/18/2024] Open
Abstract
The sensing of and response to ambient chemical gradients by microorganisms via chemotaxis regulates many microbial processes fundamental to ecosystem function, human health, and disease. Microfluidics has emerged as an indispensable tool for the study of microbial chemotaxis, enabling precise, robust, and reproducible control of spatiotemporal chemical conditions. Previous techniques include combining laminar flow patterning and stop-flow diffusion to produce quasi-steady chemical gradients to directly probe single-cell responses or loading micro-wells to entice and ensnare chemotactic bacteria in quasi-steady chemical conditions. Such microfluidic approaches exemplify a trade-off between high spatiotemporal resolution of cell behavior and high-throughput screening of concentration-specific chemotactic responses. However, both aspects are necessary to disentangle how a diverse range of chemical compounds and concentrations mediate microbial processes such as nutrient uptake, reproduction, and chemorepulsion from toxins. Here, we present a protocol for the multiplexed chemotaxis device (MCD), a parallelized microfluidic platform for efficient, high-throughput, and high-resolution chemotaxis screening of swimming microbes across a range of chemical concentrations. The first layer of the two-layer polydimethylsiloxane (PDMS) device comprises a serial dilution network designed to produce five logarithmically diluted chemostimulus concentrations plus a control from a single chemical solution input. Laminar flow in the second device layer brings a cell suspension and buffer solution into contact with the chemostimuli solutions in each of six separate chemotaxis assays, in which microbial responses are imaged simultaneously over time. The MCD is produced via standard photography and soft lithography techniques and provides robust, repeatable chemostimulus concentrations across each assay in the device. This microfluidic platform provides a chemotaxis assay that blends high-throughput screening approaches with single-cell resolution to achieve a more comprehensive understanding of chemotaxis-mediated microbial processes. Key features • Microchannel master molds are fabricated using photolithography techniques in a clean room with a mask aligner to fabricate multilevel feature heights. • The microfluidic device is fabricated from PDMS using standard soft lithography replica molding from the master molds. • The resulting microchannel requires a one-time calibration of the driving inlet pressures, after which devices from the same master molds have robust performance. • The microfluidic platform is optimized and tested for measuring chemotaxis of swimming prokaryotes.
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Affiliation(s)
- Michael R Stehnach
- Department of Mechanical Engineering, Tufts University, Medford, MA, USA
- Department of Physics, Brandeis University, Waltham, MA, USA
| | - Richard J Henshaw
- Department of Mechanical Engineering, Tufts University, Medford, MA, USA
- Institute of Environmental Engineering, ETH Zürich, Zürich, Switzerland
| | - Sheri A Floge
- Department of Biology, Wake Forest University, Winston-Salem, NC, USA
| | - Jeffrey S Guasto
- Department of Mechanical Engineering, Tufts University, Medford, MA, USA
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3
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Wheeler JHR, Foster KR, Durham WM. Individual bacterial cells can use spatial sensing of chemical gradients to direct chemotaxis on surfaces. Nat Microbiol 2024; 9:2308-2322. [PMID: 39227714 PMCID: PMC11371657 DOI: 10.1038/s41564-024-01729-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 05/10/2024] [Indexed: 09/05/2024]
Abstract
Swimming bacteria navigate chemical gradients using temporal sensing to detect changes in concentration over time. Here we show that surface-attached bacteria use a fundamentally different mode of sensing during chemotaxis. We combined microfluidic experiments, massively parallel cell tracking and fluorescent reporters to study how Pseudomonas aeruginosa senses chemical gradients during pili-based 'twitching' chemotaxis on surfaces. Unlike swimming cells, we found that temporal changes in concentration did not induce motility changes in twitching cells. We then quantified the chemotactic behaviour of stationary cells by following changes in the sub-cellular localization of fluorescent proteins as cells are exposed to a gradient that alternates direction. These experiments revealed that P. aeruginosa cells can directly sense differences in concentration across the lengths of their bodies, even in the presence of strong temporal fluctuations. Our work thus overturns the widely held notion that bacterial cells are too small to directly sense chemical gradients in space.
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Affiliation(s)
- James H R Wheeler
- Department of Physics and Astronomy, University of Sheffield, Sheffield, UK
- Department of Biology, University of Oxford, Oxford, UK
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Kevin R Foster
- Department of Biology, University of Oxford, Oxford, UK.
- Department of Biochemistry, University of Oxford, Oxford, UK.
| | - William M Durham
- Department of Physics and Astronomy, University of Sheffield, Sheffield, UK.
- Department of Biology, University of Oxford, Oxford, UK.
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Martínez-Pérez C, Zweifel ST, Pioli R, Stocker R. Space, the final frontier: The spatial component of phytoplankton-bacterial interactions. Mol Microbiol 2024. [PMID: 38970428 DOI: 10.1111/mmi.15293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 06/17/2024] [Accepted: 06/24/2024] [Indexed: 07/08/2024]
Abstract
Microscale interactions between marine phytoplankton and bacteria shape the microenvironment of individual cells, impacting their physiology and ultimately influencing global-scale biogeochemical processes like carbon and nutrient cycling. In dilute environments such as the ocean water column, metabolic exchange between microorganisms likely requires close proximity between partners. However, the biological strategies to achieve this physical proximity remain an understudied aspect of phytoplankton-bacterial associations. Understanding the mechanisms by which these microorganisms establish and sustain spatial relationships and the extent to which spatial proximity is necessary for interactions to occur, is critical to learning how spatial associations influence the ecology of phytoplankton and bacterial communities. Here, we provide an overview of current knowledge on the role of space in shaping interactions among ocean microorganisms, encompassing behavioural and metabolic evidence. We propose that characterising phytoplankton-bacterial interactions from a spatial perspective can contribute to a mechanistic understanding of the establishment and maintenance of these associations and, consequently, an enhanced ability to predict the impact of microscale processes on ecosystem-wide phenomena.
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Affiliation(s)
- Clara Martínez-Pérez
- Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland
| | - Sophie T Zweifel
- Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland
| | - Roberto Pioli
- Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland
| | - Roman Stocker
- Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland
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5
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Seymour JR, Brumley DR, Stocker R, Raina JB. Swimming towards each other: the role of chemotaxis in bacterial interactions. Trends Microbiol 2024; 32:640-649. [PMID: 38212193 DOI: 10.1016/j.tim.2023.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 12/18/2023] [Accepted: 12/19/2023] [Indexed: 01/13/2024]
Abstract
Chemotaxis allows microorganisms to direct movement in response to chemical stimuli. Bacteria use this behaviour to develop spatial associations with animals and plants, and even larger microbes. However, current theory suggests that constraints imposed by the limits of chemotactic sensory systems will prevent sensing of chemical gradients emanating from cells smaller than a few micrometres, precluding the utility of chemotaxis in interactions between individual bacteria. Yet, recent evidence has revealed surprising levels of bacterial chemotactic precision, as well as a role for chemotaxis in metabolite exchange between bacterial cells. If indeed widespread, chemotactic sensing between bacteria could represent an important, but largely overlooked, phenotype within interbacterial interactions, and play a significant role in shaping cooperative and competitive relationships.
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Affiliation(s)
- Justin R Seymour
- Climate Change Cluster, University of Technology Sydney, Broadway, New South Wales, Australia.
| | - Douglas R Brumley
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Victoria, Australia.
| | - Roman Stocker
- Institute for Environmental Engineering, Department of Civil, Environmental, and Geomatic Engineering, ETH Zurich, Zurich, Switzerland
| | - Jean-Baptiste Raina
- Climate Change Cluster, University of Technology Sydney, Broadway, New South Wales, Australia.
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6
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Xu Q, Ali S, Afzal M, Nizami AS, Han S, Dar MA, Zhu D. Advancements in bacterial chemotaxis: Utilizing the navigational intelligence of bacteria and its practical applications. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 931:172967. [PMID: 38705297 DOI: 10.1016/j.scitotenv.2024.172967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 04/06/2024] [Accepted: 05/01/2024] [Indexed: 05/07/2024]
Abstract
The fascinating world of microscopic life unveils a captivating spectacle as bacteria effortlessly maneuver through their surroundings with astonishing accuracy, guided by the intricate mechanism of chemotaxis. This review explores the complex mechanisms behind this behavior, analyzing the flagellum as the driving force and unraveling the intricate signaling pathways that govern its movement. We delve into the hidden costs and benefits of this intricate skill, analyzing its potential to propagate antibiotic resistance gene while shedding light on its vital role in plant colonization and beneficial symbiosis. We explore the realm of human intervention, considering strategies to manipulate bacterial chemotaxis for various applications, including nutrient cycling, algal bloom and biofilm formation. This review explores the wide range of applications for bacterial capabilities, from targeted drug delivery in medicine to bioremediation and disease control in the environment. Ultimately, through unraveling the intricacies of bacterial movement, we can enhance our comprehension of the intricate web of life on our planet. This knowledge opens up avenues for progress in fields such as medicine, agriculture, and environmental conservation.
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Affiliation(s)
- Qi Xu
- International Joint Laboratory on Synthetic Biology and Biomass Biorefinery, Biofuels Institute, School of Emergency Management, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, PR China
| | - Shehbaz Ali
- International Joint Laboratory on Synthetic Biology and Biomass Biorefinery, Biofuels Institute, School of Emergency Management, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, PR China; Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou University of Science and Technology, Suzhou 215009, PR China
| | - Muhammad Afzal
- Soil & Environmental Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Faisalabad, Pakistan
| | - Abdul-Sattar Nizami
- Sustainable Development Study Centre, Government College University, Lahore 54000, Pakistan
| | - Song Han
- Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou University of Science and Technology, Suzhou 215009, PR China
| | - Mudasir A Dar
- International Joint Laboratory on Synthetic Biology and Biomass Biorefinery, Biofuels Institute, School of Emergency Management, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, PR China
| | - Daochen Zhu
- International Joint Laboratory on Synthetic Biology and Biomass Biorefinery, Biofuels Institute, School of Emergency Management, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, PR China; Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou University of Science and Technology, Suzhou 215009, PR China.
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7
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Salek MM, Carrara F, Zhou J, Stocker R, Jimenez‐Martinez J. Multiscale Porosity Microfluidics to Study Bacterial Transport in Heterogeneous Chemical Landscapes. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2310121. [PMID: 38445967 PMCID: PMC11132056 DOI: 10.1002/advs.202310121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Indexed: 03/07/2024]
Abstract
Microfluidic models are proving to be powerful systems to study fundamental processes in porous media, due to their ability to replicate topologically complex environments while allowing detailed, quantitative observations at the pore scale. Yet, while porous media such as living tissues, geological substrates, or industrial systems typically display a porosity that spans multiple scales, most microfluidic models to date are limited to a single porosity or a small range of pore sizes. Here, a novel microfluidic system with multiscale porosity is presented. By embedding polyacrylamide (PAAm) hydrogel structures through in-situ photopolymerization in a landscape of microfabricated polydimethylsiloxane (PDMS) pillars with varying spacing, micromodels with porosity spanning several orders of magnitude, from nanometers to millimeters are created. Experiments conducted at different porosity patterns demonstrate the potential of this approach to characterize fundamental and ubiquitous biological and geochemical transport processes in porous media. Accounting for multiscale porosity allows studies of the resulting heterogeneous fluid flow and concentration fields of transported chemicals, as well as the biological behaviors associated with this heterogeneity, such as bacterial chemotaxis. This approach brings laboratory studies of transport in porous media a step closer to their natural counterparts in the environment, industry, and medicine.
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Affiliation(s)
- M. Mehdi Salek
- Department of Biological Engineering, School of EngineeringMassachusetts Institute of TechnologyCambridgeMAUSA
- Department of CivilEnvironmental and Geomatic EngineeringInstitute of Environmental EngineeringETH ZurichZurichSwitzerland
| | - Francesco Carrara
- Department of CivilEnvironmental and Geomatic EngineeringInstitute of Environmental EngineeringETH ZurichZurichSwitzerland
| | - Jiande Zhou
- Department of CivilEnvironmental and Geomatic EngineeringInstitute of Environmental EngineeringETH ZurichZurichSwitzerland
- Microsystems LaboratoryInstitute of MicroengineeringSchool of EngineeringEPFLLausanneSwitzerland
| | - Roman Stocker
- Department of CivilEnvironmental and Geomatic EngineeringInstitute of Environmental EngineeringETH ZurichZurichSwitzerland
| | - Joaquin Jimenez‐Martinez
- Department of CivilEnvironmental and Geomatic EngineeringInstitute of Environmental EngineeringETH ZurichZurichSwitzerland
- Department of Water Resources and Drinking WaterEawagDubendorfSwitzerland
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Ugolini GS, Wang M, Secchi E, Pioli R, Ackermann M, Stocker R. Microfluidic approaches in microbial ecology. LAB ON A 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] [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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Yang J, Xie J, Chen H, Zhu S, Hou X, Zhang Z. Diversity and Biological Characteristics of Seed-Borne Bacteria of Achnatherum splendens. Microorganisms 2024; 12:339. [PMID: 38399743 PMCID: PMC10892246 DOI: 10.3390/microorganisms12020339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 01/29/2024] [Accepted: 02/01/2024] [Indexed: 02/25/2024] Open
Abstract
As a high-quality plant resource for ecological restoration, Achnatherum splendens has strong adaptability and wide distribution. It is a constructive species of alkaline grassland in Northwest China. The close relationship between seed-borne bacteria and seeds causes a specific co-evolutionary effect which can enhance the tolerance of plants under various stresses. In this study, 272 bacterial isolates were isolated from the seeds of Achnatherum splendens in 6 different provinces of China. In total, 41 dominant strains were identified, and their motility, biofilm formation ability and antibiotic resistance were analyzed. The results showed that the bacteria of Achnatherum splendens belonged to 3 phyla and 14 genera, of which Firmicutes was the dominant phylum and Bacillus was the dominant genus. The motility and biofilm formation ability of the isolated strains were studied. It was found that there were six strains with a moving diameter greater than 8 cm. There were 16 strains with strong biofilm formation ability, among which Bacillus with biofilm formation ability was the most common, accounting for 37.5%. The analysis of antibiotic resistance showed that sulfonamides had stronger antibacterial ability to strains. Correlation analysis showed that the resistance of strains to aminoglycosides (kanamycin, amikacin, and gentamicin) was significantly positively correlated with their biofilm formation ability. This study provides fungal resources for improving the tolerance of plants under different stresses. In addition, this is the first report on the biological characteristics of bacteria in Achnatherum splendens.
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Affiliation(s)
| | | | | | | | | | - Zhenfen Zhang
- Key Laboratory of Grassland Ecosystem, Ministry of Education, Pratacultural College, Gansu Agricultural University, Lanzhou 730070, China; (J.Y.); (J.X.); (H.C.); (S.Z.); (X.H.)
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10
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Zhang H, Tan Y, Zhou Y, Liu J, Xia X. Light-dark fluctuated metabolic features of diazotrophic and non-diazotrophic cyanobacteria and their coexisting bacteria. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 910:168702. [PMID: 37992836 DOI: 10.1016/j.scitotenv.2023.168702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 11/17/2023] [Accepted: 11/17/2023] [Indexed: 11/24/2023]
Abstract
Cyanobacteria, the most abundant photosynthetic organisms in oceans, are tightly associated with diverse microbiota. However, the relationships between heterotrophic bacteria and cyanobacteria, particularly the diazotrophic group, are not fully understood. Here, we compared diel gene expressions of N2 fixing cyanobacteria Crocosphaera watsonii WH0003 and non-diazotrophic Synechococcus sp. RS9902 and their associated bacteria using metatranscriptomics approach. WH0003 showed significant up-regulation of O2 restriction and oxidative phosphorylation related genes at nighttime due to large carbon and energy investments for active N2 fixation. In contrast, RS9902 had higher expression for those genes at daytime. The two cyanobacteria hosted distinct bacterial communities with clear separate substrate utilization niches to reduce competition. Light-dark partitioning of nutrient acquisition among the dominant bacterial groups likely contributed to the dynamic balance for community coexistence. Moreover, particle-attached (PA) bacteria in RS9902 largely expressed glycoside hydrolases to hydrolyze complex carbohydrate compounds, while free-living (FL) bacteria priorly assimilated soluble, diffusible molecules. Spatial partitioning of nutrient acquisition between PA and FL bacteria implied that location initially influenced metabolic features of host associated bacteria. Our results advance knowledge on light-dark regulated metabolic activities of diazotrophic and non-diazotrophic cyanobacteria, and provide new insights into the coexisting strategies of different bacterial groups.
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Affiliation(s)
- Hao Zhang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Yehui Tan
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Youping Zhou
- Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Jiaxing Liu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China..
| | - Xiaomin Xia
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China..
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11
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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] [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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12
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Ros-Rocher N, Brunet T. What is it like to be a choanoflagellate? Sensation, processing and behavior in the closest unicellular relatives of animals. Anim Cogn 2023; 26:1767-1782. [PMID: 37067637 PMCID: PMC10770216 DOI: 10.1007/s10071-023-01776-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 04/05/2023] [Accepted: 04/07/2023] [Indexed: 04/18/2023]
Abstract
All animals evolved from a single lineage of unicellular precursors more than 600 million years ago. Thus, the biological and genetic foundations for animal sensation, cognition and behavior must necessarily have arisen by modifications of pre-existing features in their unicellular ancestors. Given that the single-celled ancestors of the animal kingdom are extinct, the only way to reconstruct how these features evolved is by comparing the biology and genomic content of extant animals to their closest living relatives. Here, we reconstruct the Umwelt (the subjective, perceptive world) inhabited by choanoflagellates, a group of unicellular (or facultatively multicellular) aquatic microeukaryotes that are the closest living relatives of animals. Although behavioral research on choanoflagellates remains patchy, existing evidence shows that they are capable of chemosensation, photosensation and mechanosensation. These processes often involve specialized sensorimotor cellular appendages (cilia, microvilli, and/or filopodia) that resemble those that underlie perception in most animal sensory cells. Furthermore, comparative genomics predicts an extensive "sensory molecular toolkit" in choanoflagellates, which both provides a potential basis for known behaviors and suggests the existence of a largely undescribed behavioral complexity that presents exciting avenues for future research. Finally, we discuss how facultative multicellularity in choanoflagellates might help us understand how evolution displaced the locus of decision-making from a single cell to a collective, and how a new space of behavioral complexity might have become accessible in the process.
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Affiliation(s)
- Núria Ros-Rocher
- Evolutionary Cell Biology and Evolution of Morphogenesis Unit, Institut Pasteur, Université Paris-Cité, CNRS UMR3691, 25-28 Rue du Docteur Roux, 75015, Paris, France
| | - Thibaut Brunet
- Evolutionary Cell Biology and Evolution of Morphogenesis Unit, Institut Pasteur, Université Paris-Cité, CNRS UMR3691, 25-28 Rue du Docteur Roux, 75015, Paris, France.
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13
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Zou D, Chen J, Zhang C, Kao SJ, Liu H, Li M. Diversity and salinity adaptations of ammonia oxidizing archaea in three estuaries of China. Appl Microbiol Biotechnol 2023; 107:6897-6909. [PMID: 37702790 DOI: 10.1007/s00253-023-12761-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 07/22/2023] [Accepted: 08/30/2023] [Indexed: 09/14/2023]
Abstract
Ammonia-oxidizing archaea (AOA) are ubiquitously found in diverse habitats and play pivotal roles in the nitrogen and carbon cycle, especially in estuarine and coastal environments. Despite the fact that the diversity and distribution of AOA are thought to be tightly linked to habitats, little is known about the relationship that underpins their genomic traits, adaptive potentials, and ecological niches. Here, we have characterized and compared the AOA community in three estuaries of China using metagenomics. AOA were the dominant ammonia oxidizers in the three estuaries. Through phylogenetic analyses, five major AOA groups were identified, including the Nitrosomarinus-like, Nitrosopumilus-like, Aestuariumsis-like, Nitrosarchaeum-like, and Nitrosopelagicus-like groups. Statistical analyses showed that the aquatic and sedimentary AOA communities were mainly influenced by spatial factors (latitude and water depth) and environmental factors (salinity, pH, and dissolved oxygen) in estuaries, respectively. Compared to AOA dwelling in terrestrial and marine habitats, estuarine AOA encoded more genes involved in glucose and amino acid metabolism, transport systems, osmotic control, and cell motility. The low proteome isoelectric points (pI), high content of acidic amino acids, and the presence of potassium ion and mechanosensitive channels suggest a "salt-in" strategy for estuarine AOA to counteract high osmolarity in their surroundings. Our findings have indicated potential adaptation strategies and highlighted their importance in the estuarine nitrogen and carbon cycles. KEY POINTS: • Spatial and environmental factors influence water and sediment AOA respectively. • Estuarine AOA share low proteome isoelectric value and high acid amino acids content. • AOA adaptation to estuaries is likely resulted from their unique genomic features.
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Affiliation(s)
- Dayu Zou
- Archaeal Biology Center, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China
| | - Jianfang Chen
- Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, 310012, China
| | - Chuanlun Zhang
- Shenzhen Key Laboratory of Marine Archaea Geo-Omics, Southern University of Science and Technology, Shenzhen, 518000, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 510000, China
| | - Shuh-Ji Kao
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361000, China
| | - Hongbin Liu
- Department of Ocean Science and Hong Kong Branch of Southern Marine Science & Engineering Guangdong Laboratory (Guangzhou), The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Meng Li
- Archaeal Biology Center, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China.
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China.
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14
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Jackrel SL, White JD, Perez-Coronel E, Koch RY. Selection for oligotrophy among bacteria inhabiting host microbiomes. mBio 2023; 14:e0141523. [PMID: 37646528 PMCID: PMC10653850 DOI: 10.1128/mbio.01415-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 07/04/2023] [Indexed: 09/01/2023] Open
Abstract
IMPORTANCE Understanding how natural selection has historically shaped the traits of microbial populations comprising host microbiomes would help predict how the functions of these microbes may continue to evolve over space and time. Numerous host-associated microbes have been found to adapt to their host, sometimes becoming obligate symbionts, whereas free-living microbes are best known to adapt to their surrounding environment. Our study assessed the selective pressures of both the host environment and the surrounding external environment in shaping the functional potential of host-associated bacteria. Despite residing within the resource-rich microbiome of their hosts, we demonstrate that host-associated heterotrophic bacteria show evidence of trait selection that matches the nutrient availability of their broader surrounding environment. These findings illustrate the complex mix of selective pressures that likely shape the present-day function of bacteria found inhabiting host microbiomes. Our study lends insight into the shifts in function that may occur as environments fluctuate over time.
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Affiliation(s)
- Sara L. Jackrel
- Department of Ecology, Behavior and Evolution, University of California San Diego, La Jolla, California, USA
| | - Jeffrey D. White
- Department of Biology, Framingham State University, Framingham, Massachusetts, USA
| | - Elisabet Perez-Coronel
- Department of Ecology, Behavior and Evolution, University of California San Diego, La Jolla, California, USA
| | - Ryan Y. Koch
- Department of Ecology, Behavior and Evolution, University of California San Diego, La Jolla, California, USA
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15
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Chen T, Pu M, Subramanian S, Kearns D, Rowe-Magnus D. PlzD modifies Vibrio vulnificus foraging behavior and virulence in response to elevated c-di-GMP. mBio 2023; 14:e0153623. [PMID: 37800901 PMCID: PMC10653909 DOI: 10.1128/mbio.01536-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 08/21/2023] [Indexed: 10/07/2023] Open
Abstract
IMPORTANCE Many free-swimming bacteria propel themselves through liquid using rotary flagella, and mounting evidence suggests that the inhibition of flagellar rotation initiates biofilm formation, a sessile lifestyle that is a nearly universal surface colonization paradigm in bacteria. In general, motility and biofilm formation are inversely regulated by the intracellular second messenger bis-(3´-5´)-cyclic dimeric guanosine monophosphate (c-di-GMP). Here, we identify a protein, PlzD, bearing a conserved c-di-GMP binding PilZ domain that localizes to the flagellar pole in a c-di-GMP-dependent manner and alters the foraging behavior, biofilm, and virulence characteristics of the opportunistic human pathogen, Vibrio vulnificus. Our data suggest that PlzD interacts with components of the flagellar stator to decrease bacterial swimming speed and changes in swimming direction, and these activities are enhanced when cellular c-di-GMP levels are elevated. These results reveal a physical link between a second messenger (c-di-GMP) and an effector (PlzD) that promotes transition from a motile to a sessile state in V. vulnificus.
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Affiliation(s)
- Tianyi Chen
- Department of Biology, Indiana University Bloomington, Bloomington, Indiana, USA
| | - Meng Pu
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
| | - Sundharraman Subramanian
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
| | - Dan Kearns
- Department of Biology, Indiana University Bloomington, Bloomington, Indiana, USA
| | - Dean Rowe-Magnus
- Department of Biology, Indiana University Bloomington, Bloomington, Indiana, USA
- Department of Molecular and Cellular Biochemistry, Indiana University Bloomington, Bloomington, Indiana, USA
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16
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Shoup D, Ursell T. Bacterial bioconvection confers context-dependent growth benefits and is robust under varying metabolic and genetic conditions. J Bacteriol 2023; 205:e0023223. [PMID: 37787517 PMCID: PMC10601612 DOI: 10.1128/jb.00232-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 08/17/2023] [Indexed: 10/04/2023] Open
Abstract
Microbes often respond to environmental cues by adopting collective behaviors-like biofilms or swarming-that benefit the population. During "bioconvection," microbes gather in dense groups and plume downward through fluid environments, driving flow and mixing on the scale of millions of cells. Though bioconvection was observed a century ago, the effects of differing physical and chemical inputs and its potential selective advantages for different species of microbes remain largely unexplored. In Bacillus subtilis, vertical oxygen gradients that originate from air-liquid interfaces create cell-density inversions that drive bioconvection. Here, we develop Escherichia coli as a complementary model for the study of bioconvection. In the context of a still fluid, we found that motile and chemotactic genotypes of both E. coli and B. subtilis bioconvect and show increased growth compared to immotile or non-chemotactic genotypes, whereas in a well-mixed fluid, there is no growth advantage to motility or chemotaxis. We found that fluid depth, cell concentration, and carbon availability affect the emergence and timing of bioconvective patterns. Also, whereas B. subtilis requires oxygen gradients to bioconvect, E. coli deficient in aerotaxis (Δaer) or energy-taxis (Δtsr) still bioconvects, as do cultures that lack an air-liquid interface. Thus, in two distantly related microbes, bioconvection may confer context-dependent growth benefits, and E. coli bioconvection is robustly elicited by multiple types of chemotaxis. These results greatly expand the set of physical and metabolic conditions in which this striking collective behavior can be expected and demonstrate its potential to be a generic force for behavioral selection across ecological contexts. IMPORTANCE Individual microorganisms frequently move in response to gradients in their fluid environment, with corresponding metabolic benefits. At a population level, such movements can create density variations in a fluid that couple to gravity and drive large-scale convection and mixing called bioconvection. In this work, we provide evidence that this collective behavior confers a selective benefit on two distantly related species of bacteria. We develop new methods for quantifying this behavior and show that bioconvection in Escherichia coli is surprisingly robust to changes in cell concentration, fluid depth, interface conditions, metabolic sensing, and carbon availability. These results greatly expand the set of conditions known to elicit this collective behavior and indicate its potential to be a selective pressure across ecological contexts.
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Affiliation(s)
- Daniel Shoup
- Department of Physics, University of Oregon, Eugene, Oregon, USA
- Rocky Mountain National Laboratories (NIH), Hamilton, Montana, USA
| | - Tristan Ursell
- Department of Physics, University of Oregon, Eugene, Oregon, USA
- Material Science Institute, Eugene, Oregon, USA
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon, USA
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17
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Mondal A, Banerjee S. Impact of critical eddy diffusivity on seasonal bloom dynamics of Phytoplankton in a global set of aquatic environments. Sci Rep 2023; 13:17141. [PMID: 37816845 PMCID: PMC10564959 DOI: 10.1038/s41598-023-43745-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 09/27/2023] [Indexed: 10/12/2023] Open
Abstract
The intensity of eddy diffusivity and the spatial average of water velocity at the depths of the water column in oceans and lakes play a fundamental role in phytoplankton production and phytoplankton and zooplankton biomass, and community composition. The critical depth and intensity of turbulent mixing within the water column profoundly affect phytoplankton biomass, which depends on the sinking characteristic of planktonic algal species. We propose an Nutrient-Phytoplankton-Zooplankton (NPZ) model in 3D space with light and nutrient-limited growth in a micro-scale ecological study. To incorporate micro-scale observation of phytoplankton intermittency in bloom mechanism in stationary as well as oceanic turbulent flows, a moment closure method has been applied in this study. Experimental observations imply that an increase in turbulence is sometimes ecologically advantageous for non-motile planktonic algae. How do we ensure whether there will be a bloom cycle or whether there can be any bloom at all when the existing phytoplankton group is buoyant, heavier, motile, or non-motile? To address these questions, we have explored the effects of critical depth, the intensity of eddy diffusivity, spatial average of water velocity, on the concentration as well as horizontal and vertical distribution of phytoplankton and zooplankton biomass using a mathematical model and moment closure technique. We quantify a critical threshold value of eddy diffusivity and the spatial average of water velocity and observe the corresponding changes in the phytoplankton bloom dynamics. Our results highlight the importance of eddy diffusivity and the spatial average of water velocity on seasonal bloom dynamics and also mimic different real-life bloom scenarios in Mikawa Bay (Japan), Tokyo Bay (Japan), Arakawa River (Japan), the Baltic Sea, the North Atlantic Ocean, Gulf Alaska, the North Arabian Sea, the Cantabrian Sea, Lake Nieuwe Meer (Netherlands) and several shallower lakes.
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Affiliation(s)
- Arpita Mondal
- Department of Mathematics, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 247667, India
| | - Sandip Banerjee
- Department of Mathematics, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 247667, India.
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18
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Piskovsky V, Oliveira NM. Bacterial motility can govern the dynamics of antibiotic resistance evolution. Nat Commun 2023; 14:5584. [PMID: 37696800 PMCID: PMC10495427 DOI: 10.1038/s41467-023-41196-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 08/24/2023] [Indexed: 09/13/2023] Open
Abstract
Spatial heterogeneity in antibiotic concentrations is thought to accelerate the evolution of antibiotic resistance, but current theory and experiments have overlooked the effect of cell motility on bacterial adaptation. Here, we study bacterial evolution in antibiotic landscapes with a quantitative model where bacteria evolve under the stochastic processes of proliferation, death, mutation and migration. Numerical and analytical results show that cell motility can both accelerate and decelerate bacterial adaptation by affecting the degree of genotypic mixing and ecological competition. Moreover, we find that for sufficiently high rates, cell motility can limit bacterial survival, and we derive conditions for all these regimes. Similar patterns are observed in more complex scenarios, namely where bacteria can bias their motion in chemical gradients (chemotaxis) or switch between motility phenotypes either stochastically or in a density-dependent manner. Overall, our work reveals limits to bacterial adaptation in antibiotic landscapes that are set by cell motility.
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Affiliation(s)
- Vit Piskovsky
- Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA, UK
- Mathematical Institute, University of Oxford, Woodstock Road, Oxford, OX2 6GG, UK
| | - Nuno M Oliveira
- Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA, UK.
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, CB3 0ES, UK.
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19
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Grognot M, Nam JW, Elson LE, Taute KM. Physiological adaptation in flagellar architecture improves Vibrio alginolyticus chemotaxis in complex environments. Proc Natl Acad Sci U S A 2023; 120:e2301873120. [PMID: 37579142 PMCID: PMC10450658 DOI: 10.1073/pnas.2301873120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 07/10/2023] [Indexed: 08/16/2023] Open
Abstract
Bacteria navigate natural habitats with a wide range of mechanical properties, from the ocean to the digestive tract and soil, by rotating helical flagella like propellers. Species differ in the number, position, and shape of their flagella, but the adaptive value of these flagellar architectures is unclear. Many species traverse multiple types of environments, such as pathogens inside and outside a host. We investigate the hypothesis that flagellar architectures mediate environment-specific benefits in the marine pathogen Vibrio alginolyticus which exhibits physiological adaptation to the mechanical environment. In addition to its single polar flagellum, the bacterium produces lateral flagella in environments that differ mechanically from water. These are known to facilitate surface motility and attachment. We use high-throughput 3D bacterial tracking to quantify chemotactic performance of both flagellar architectures in three archetypes of mechanical environments relevant to the bacterium's native habitats: water, polymer solutions, and hydrogels. We reveal that lateral flagella impede chemotaxis in water by lowering the swimming speed but improve chemotaxis in both types of complex environments. Statistical trajectory analysis reveals two distinct underlying behavioral mechanisms: In viscous solutions of the polymer PVP K90, lateral flagella increase the swimming speed. In agar hydrogels, lateral flagella improve overall chemotactic performance, despite lowering the swimming speed, by preventing trapping in pores. Our findings show that lateral flagella are multipurpose tools with a wide range of applications beyond surfaces. They implicate flagellar architecture as a mediator of environment-specific benefits and point to a rich space of bacterial navigation behaviors in complex environments.
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Affiliation(s)
- Marianne Grognot
- Rowland Institute, Harvard University, Cambridge, MA02142
- Institute of Medical Microbiology, Rheinisch-Westfälische Technische Hochschule University Hospital Aachen, Rheinisch-Westfälische Technische Hochschule University, Aachen52074, Germany
| | - Jong Woo Nam
- Rowland Institute, Harvard University, Cambridge, MA02142
| | | | - Katja M. Taute
- Rowland Institute, Harvard University, Cambridge, MA02142
- Biozentrum, Ludwig-Maximilians-Universität München, Martinsried82152, Germany
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20
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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] [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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21
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Noell SE, Hellweger FL, Temperton B, Giovannoni SJ. A Reduction of Transcriptional Regulation in Aquatic Oligotrophic Microorganisms Enhances Fitness in Nutrient-Poor Environments. Microbiol Mol Biol Rev 2023; 87:e0012422. [PMID: 36995249 PMCID: PMC10304753 DOI: 10.1128/mmbr.00124-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/31/2023] Open
Abstract
In this review, we consider the regulatory strategies of aquatic oligotrophs, microbial cells that are adapted to thrive under low-nutrient concentrations in oceans, lakes, and other aquatic ecosystems. Many reports have concluded that oligotrophs use less transcriptional regulation than copiotrophic cells, which are adapted to high nutrient concentrations and are far more common subjects for laboratory investigations of regulation. It is theorized that oligotrophs have retained alternate mechanisms of regulation, such as riboswitches, that provide shorter response times and smaller amplitude responses and require fewer cellular resources. We examine the accumulated evidence for distinctive regulatory strategies in oligotrophs. We explore differences in the selective pressures copiotrophs and oligotrophs encounter and ask why, although evolutionary history gives copiotrophs and oligotrophs access to the same regulatory mechanisms, they might exhibit distinctly different patterns in how these mechanisms are used. We discuss the implications of these findings for understanding broad patterns in the evolution of microbial regulatory networks and their relationships to environmental niche and life history strategy. We ask whether these observations, which have emerged from a decade of increased investigation of the cell biology of oligotrophs, might be relevant to recent discoveries of many microbial cell lineages in nature that share with oligotrophs the property of reduced genome size.
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Affiliation(s)
- Stephen E. Noell
- Department of Microbiology, Oregon State University, Corvallis, Oregon, USA
| | | | - Ben Temperton
- School of Biosciences, University of Exeter, Exeter, United Kingdom
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22
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Snyder C, Centlivre JP, Bhute S, Shipman G, Friel AD, Viver T, Palmer M, Konstantinidis KT, Sun HJ, Rossello-Mora R, Nadeau J, Hedlund BP. Microbial Motility at the Bottom of North America: Digital Holographic Microscopy and Genomic Motility Signatures in Badwater Spring, Death Valley National Park. ASTROBIOLOGY 2023; 23:295-307. [PMID: 36625891 DOI: 10.1089/ast.2022.0090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Motility is widely distributed across the tree of life and can be recognized by microscopy regardless of phylogenetic affiliation, biochemical composition, or mechanism. Microscopy has thus been proposed as a potential tool for detection of biosignatures for extraterrestrial life; however, traditional light microscopy is poorly suited for this purpose, as it requires sample preparation, involves fragile moving parts, and has a limited volume of view. In this study, we deployed a field-portable digital holographic microscope (DHM) to explore microbial motility in Badwater Spring, a saline spring in Death Valley National Park, and complemented DHM imaging with 16S rRNA gene amplicon sequencing and shotgun metagenomics. The DHM identified diverse morphologies and distinguished run-reverse-flick and run-reverse types of flagellar motility. PICRUSt2- and literature-based predictions based on 16S rRNA gene amplicons were used to predict motility genotypes/phenotypes for 36.0-60.1% of identified taxa, with the predicted motile taxa being dominated by members of Burkholderiaceae and Spirochaetota. A shotgun metagenome confirmed the abundance of genes encoding flagellar motility, and a Ralstonia metagenome-assembled genome encoded a full flagellar gene cluster. This study demonstrates the potential of DHM for planetary life detection, presents the first microbial census of Badwater Spring and brine pool, and confirms the abundance of mobile microbial taxa in an extreme environment.
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Affiliation(s)
- Carl Snyder
- Department of Physics, Portland State University, Portland, Oregon, USA
| | - Jakob P Centlivre
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, Nevada, USA
| | - Shrikant Bhute
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, Nevada, USA
| | - Gözde Shipman
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, Nevada, USA
| | - Ariel D Friel
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, Nevada, USA
| | - Tomeu Viver
- Marine Microbiology Group, Department of Animal and Microbial Biodiversity, Mediterranean Institute for Advanced Studies (CSIC-UIB), Esporles, Illes Balears, Spain
| | - Marike Palmer
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, Nevada, USA
| | | | - Henry J Sun
- Desert Research Institute, Las Vegas, Nevada, USA
| | - Ramon Rossello-Mora
- Marine Microbiology Group, Department of Animal and Microbial Biodiversity, Mediterranean Institute for Advanced Studies (CSIC-UIB), Esporles, Illes Balears, Spain
| | - Jay Nadeau
- Department of Physics, Portland State University, Portland, Oregon, USA
| | - Brian P Hedlund
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, Nevada, USA
- Nevada Institute of Personalized Medicine, Las Vegas, Nevada, USA
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23
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Chemotaxis increases metabolic exchanges between marine picophytoplankton and heterotrophic bacteria. Nat Microbiol 2023; 8:510-521. [PMID: 36759754 DOI: 10.1038/s41564-023-01327-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [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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24
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Noell SE, Brennan E, Washburn Q, Davis EW, Hellweger FL, Giovannoni SJ. Differences in the regulatory strategies of marine oligotrophs and copiotrophs reflect differences in motility. Environ Microbiol 2023. [PMID: 36826469 DOI: 10.1111/1462-2920.16357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Accepted: 02/22/2023] [Indexed: 02/25/2023]
Abstract
Aquatic bacteria frequently are divided into lifestyle categories oligotroph or copiotroph. Oligotrophs have proportionately fewer transcriptional regulatory genes than copiotrophs and are generally non-motile/chemotactic. We hypothesized that the absence of chemotaxis/motility in oligotrophs prevents them from occupying nutrient patches long enough to benefit from transcriptional regulation. We first confirmed that marine oligotrophs are generally reduced in genes for transcriptional regulation and motility/chemotaxis. Next, using a non-motile oligotroph (Ca. Pelagibacter st. HTCC7211), a motile copiotroph (Alteromonas macleodii st. HOT1A3), and [14 C]l-alanine, we confirmed that l-alanine catabolism is not transcriptionally regulated in HTCC7211 but is in HOT1A3. We then found that HOT1A3 took 2.5-4 min to initiate l-alanine oxidation at patch l-alanine concentrations, compared to <30 s for HTCC7211. By modelling cell trajectories, we predicted that, in most scenarios, non-motile cells spend <2 min in patches, compared to >4 min for chemotactic/motile cells. Thus, the time necessary for transcriptional regulation to initiate prevents transcriptional regulation from being beneficial for non-motile oligotrophs. This is supported by a mechanistic model we developed, which predicted that HTCC7211 cells with transcriptional regulation of l-alanine metabolism would produce 12% of their standing ATP stock upon encountering an l-alanine patch, compared to 880% in HTCC7211 cells without transcriptional regulation.
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Affiliation(s)
- Stephen E Noell
- Department of Microbiology, Oregon State University, Corvallis, Oregon, USA
| | - Elizabeth Brennan
- Department of Microbiology, Oregon State University, Corvallis, Oregon, USA
| | - Quinn Washburn
- Department of Microbiology, Oregon State University, Corvallis, Oregon, USA
| | - Edward W Davis
- Center for Quantitative Life Sciences, Oregon State University, Oregon, USA
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25
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Borer B, Zhang IH, Baker AE, O'Toole GA, Babbin AR. Porous marine snow differentially benefits chemotactic, motile, and nonmotile bacteria. PNAS NEXUS 2022; 2:pgac311. [PMID: 36845354 PMCID: PMC9944246 DOI: 10.1093/pnasnexus/pgac311] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 12/23/2022] [Indexed: 12/28/2022]
Abstract
Particulate organic carbon settling through the marine water column is a key process that regulates the global climate by sequestering atmospheric carbon. The initial colonization of marine particles by heterotrophic bacteria represents the first step in recycling this carbon back to inorganic constituents-setting the magnitude of vertical carbon transport to the abyss. Here, we demonstrate experimentally using millifluidic devices that, although bacterial motility is essential for effective colonization of a particle leaking organic nutrients into the water column, chemotaxis specifically benefits at intermediate and higher settling velocities to navigate the particle boundary layer during the brief window of opportunity provided by a passing particle. We develop an individual-based model that simulates the encounter and attachment of bacterial cells with leaking marine particles to systematically evaluate the role of different parameters associated with bacterial run-and-tumble motility. We further use this model to explore the role of particle microstructure on the colonization efficiency of bacteria with different motility traits. We find that the porous microstructure facilitates additional colonization by chemotactic and motile bacteria, and fundamentally alters the way nonmotile cells interact with particles due to streamlines intersecting with the particle surface.
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Affiliation(s)
| | - Irene H Zhang
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology Cambridge, Cambridge, MA 02139, USA
| | - Amy E Baker
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
| | - George A O'Toole
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
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26
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Butterworth NJ, Benbow ME, Barton PS. The ephemeral resource patch concept. Biol Rev Camb Philos Soc 2022; 98:697-726. [PMID: 36517934 DOI: 10.1111/brv.12926] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 12/02/2022] [Accepted: 12/06/2022] [Indexed: 12/23/2022]
Abstract
Ephemeral resource patches (ERPs) - short lived resources including dung, carrion, temporary pools, rotting vegetation, decaying wood, and fungi - are found throughout every ecosystem. Their short-lived dynamics greatly enhance ecosystem heterogeneity and have shaped the evolutionary trajectories of a wide range of organisms - from bacteria to insects and amphibians. Despite this, there has been no attempt to distinguish ERPs clearly from other resource types, to identify their shared spatiotemporal characteristics, or to articulate their broad ecological and evolutionary influences on biotic communities. Here, we define ERPs as any distinct consumable resources which (i) are homogeneous (genetically, chemically, or structurally) relative to the surrounding matrix, (ii) host a discrete multitrophic community consisting of species that cannot replicate solely in any of the surrounding matrix, and (iii) cannot maintain a balance between depletion and renewal, which in turn, prevents multiple generations of consumers/users or reaching a community equilibrium. We outline the wide range of ERPs that fit these criteria, propose 12 spatiotemporal characteristics along which ERPs can vary, and synthesise a large body of literature that relates ERP dynamics to ecological and evolutionary theory. We draw this knowledge together and present a new unifying conceptual framework that incorporates how ERPs have shaped the adaptive trajectories of organisms, the structure of ecosystems, and how they can be integrated into biodiversity management and conservation. Future research should focus on how inter- and intra-resource variation occurs in nature - with a particular focus on resource × environment × genotype interactions. This will likely reveal novel adaptive strategies, aid the development of new eco-evolutionary theory, and greatly improve our understanding of the form and function of organisms and ecosystems.
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Affiliation(s)
- Nathan J. Butterworth
- School of Biological Sciences, Monash University Wellington Road Clayton VIC 3800 Australia
- School of Life Sciences, University of Technology Sydney 15 Broadway Ultimo NSW 2007 Australia
| | - M. Eric Benbow
- Department of Entomology, Department of Osteopathic Medical Specialties, and Ecology, Evolution and Behavior Program Michigan State University 220 Trowbridge Rd East Lansing MI 48824 USA
| | - Philip S. Barton
- Future Regions Research Centre, Federation University University Drive, Mount Helen VIC 3350 Australia
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27
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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. THE ISME JOURNAL 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] [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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28
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Impact of Microbial Uptake on the Nutrient Plume around Marine Organic Particles: High-Resolution Numerical Analysis. Microorganisms 2022; 10:microorganisms10102020. [PMID: 36296296 PMCID: PMC9611091 DOI: 10.3390/microorganisms10102020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 09/21/2022] [Accepted: 09/21/2022] [Indexed: 11/17/2022] Open
Abstract
The interactions between marine bacteria and particulate matter play a pivotal role in the biogeochemical cycles of carbon and associated inorganic elements in the oceans. Eutrophic plumes typically form around nutrient-releasing particles and host intense bacterial activities. However, the potential of bacteria to reshape the nutrient plumes remains largely unexplored. We present a high-resolution numerical analysis for the impacts of nutrient uptake by free-living bacteria on the pattern of dissolution around slow-moving particles. At the single-particle level, the nutrient field is parameterized by the Péclet and Damköhler numbers (0 < Pe < 1000, 0 < Da < 10) that quantify the relative contribution of advection, diffusion and uptake to nutrient transport. In spite of reducing the extent of the nutrient plume in the wake of the particle, bacterial uptake enhances the rates of particle dissolution and nutrient depletion. These effects are amplified when the uptake timescale is shorter than the plume lifetime (Pe/Da < 100, Da > 0.0001), while otherwise they are suppressed by advection or diffusion. Our analysis suggests that the quenching of eutrophic plumes is significant for individual phytoplankton cells, as well as marine aggregates with sizes ranging from 0.1 mm to 10 mm and sinking velocities up to 40 m per day. This microscale process has a large potential impact on microbial growth dynamics and nutrient cycling in marine ecosystems.
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29
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Arandia-Gorostidi N, Berthelot H, Calabrese F, Stryhanyuk H, Klawonn I, Iversen M, Nahar N, Grossart HP, Ploug H, Musat N. Efficient carbon and nitrogen transfer from marine diatom aggregates to colonizing bacterial groups. Sci Rep 2022; 12:14949. [PMID: 36056039 PMCID: PMC9440002 DOI: 10.1038/s41598-022-18915-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 08/22/2022] [Indexed: 11/24/2022] Open
Abstract
Bacterial degradation of sinking diatom aggregates is key for the availability of organic matter in the deep-ocean. Yet, little is known about the impact of aggregate colonization by different bacterial taxa on organic carbon and nutrient cycling within aggregates. Here, we tracked the carbon (C) and nitrogen (N) transfer from the diatom Leptocylindrus danicus to different environmental bacterial groups using a combination of 13C and 15N isotope incubation (incubated for 72 h), CARD-FISH and nanoSIMS single-cell analysis. Pseudoalteromonas bacterial group was the first colonizing diatom-aggregates, succeeded by the Alteromonas group. Within aggregates, diatom-attached bacteria were considerably more enriched in 13C and 15N than non-attached bacteria. Isotopic mass balance budget indicates that both groups showed comparable levels of diatom C in their biomass, accounting for 19 ± 7% and 15 ± 11%, respectively. In contrast to C, bacteria of the Alteromonas groups showed significantly higher levels of N derived from diatoms (77 ± 28%) than Pseudoalteromonas (47 ± 17%), suggesting a competitive advantage for Alteromonas in the N-limiting environments of the deep-sea. Our results imply that bacterial succession within diatom aggregates may largely impact taxa-specific C and N uptake, which may have important consequences for the quantity and quality of organic matter exported to the deep ocean.
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Affiliation(s)
- Nestor Arandia-Gorostidi
- Department of Isotope Biogeochemistry, Helmholtz-Centre for Environmental Research (UFZ), Permoserstrasse 15, 04318, Leipzig, Germany.
- Department of Earth System Science, Stanford University, Green Earth Sciences Building, 367 Panama St., Room 129, Stanford, CA, 94305-4216, USA.
- Department of Marine Sciences, University of Gothenburg, Gothenburg, Sweden.
| | - Hugo Berthelot
- Department of Isotope Biogeochemistry, Helmholtz-Centre for Environmental Research (UFZ), Permoserstrasse 15, 04318, Leipzig, Germany
- Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR 6539 UBO/CNRS/IRD/IFREMER, Institut Universitaire Européen de la Mer (IUEM), Brest, France
- IFREMER, DYNECO, Pelagos Laboratory, Plouzané, France
| | - Federica Calabrese
- Department of Isotope Biogeochemistry, Helmholtz-Centre for Environmental Research (UFZ), Permoserstrasse 15, 04318, Leipzig, Germany
- Department of Organismic and Evolutionary BiologyBiological Laboratories, Harvard University, 16 Divinity Avenue, Cambridge, MA, USA
| | - Hryhoriy Stryhanyuk
- Department of Isotope Biogeochemistry, Helmholtz-Centre for Environmental Research (UFZ), Permoserstrasse 15, 04318, Leipzig, Germany
| | - Isabell Klawonn
- Department of Ecology, Environment and Plant Sciences, Stockholm University, 10691, Stockholm, Sweden
- Leibniz Institute for Baltic Sea Research (IOW), Rostock, Germany
| | - Morten Iversen
- Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany
- Marum and University of Bremen, Bremen, Germany
| | - Nurun Nahar
- Department of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
- Biological and Environmental Sciences, University of Gothenburg, Box 461, 40530, Gothenburg, Sweden
| | - Hans-Peter Grossart
- Institute for Biochemistry and Biology, Potsdam University, Potsdam, Germany
- Department Plankton and Microbial Ecology, Leibniz Institute for Freshwater Ecology and Inland Fisheries, Berlin/Stechlin, Germany
| | - Helle Ploug
- Department of Marine Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Niculina Musat
- Department of Isotope Biogeochemistry, Helmholtz-Centre for Environmental Research (UFZ), Permoserstrasse 15, 04318, Leipzig, Germany.
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30
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Cruz BN, Neuer S. Particle-associated bacteria differentially influence the aggregation of the marine diatom Minutocellus polymorphus. ISME COMMUNICATIONS 2022; 2:73. [PMID: 37938280 PMCID: PMC9723735 DOI: 10.1038/s43705-022-00146-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 06/13/2022] [Accepted: 06/28/2022] [Indexed: 11/09/2023]
Abstract
The aggregation of phytoplankton leads to the settling of particulate organic carbon in the form of marine snow, making it an important process in marine biogeochemical cycles. Diatoms >20 µm in size are considered to contribute appreciably to sinking particle fluxes due to aggregation and the production of transparent exopolymeric particles (TEP), the matrix for marine snow aggregates; however, it is not known whether nano-sized (2-20 µm) diatoms are able to aggregate and produce TEP. Here, we tested the aggregation and production of TEP by the nano-diatom Minutocellus polymorphus and investigated if interactions with bacteria influence aggregation by comparing axenic M. polymorphus cultures with co-cultures of the diatom with bacterial taxa known to colonize marine snow particles. We found that M. polymorphus form sinking aggregates and produce TEP comparably to other phytoplankton groups and that aggregation and TEP production were influenced depending on the species of bacteria added. Aggregation was enhanced in the presence of Marinobacter adhaerens HP15, but not in the presence of Pseudoalteromonas carrageenovora or Vibrio thalassae. Cell aggregation mediated by interactions with specific bacterial species are possible mechanisms behind the export of nano-sized diatoms, such as M. polymorphus, especially in oligotrophic open ocean regions where small phytoplankton dominate.
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Affiliation(s)
- Bianca N Cruz
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
- Center for Fundamental and Applied Microbiomics, Biodesign Institute, Arizona State University, Tempe, AZ, USA
| | - Susanne Neuer
- School of Life Sciences, Arizona State University, Tempe, AZ, USA.
- Center for Fundamental and Applied Microbiomics, Biodesign Institute, Arizona State University, Tempe, AZ, USA.
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31
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Deroy C, Wheeler JHR, Rumianek AN, Cook PR, Durham WM, Foster KR, Walsh EJ. Reconfigurable Microfluidic Circuits for Isolating and Retrieving Cells of Interest. ACS APPLIED MATERIALS & INTERFACES 2022; 14:25209-25219. [PMID: 35604799 PMCID: PMC9185686 DOI: 10.1021/acsami.2c07177] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 05/11/2022] [Indexed: 06/15/2023]
Abstract
Microfluidic devices are widely used in many fields of biology, but a key limitation is that cells are typically surrounded by solid walls, making it hard to access those that exhibit a specific phenotype for further study. Here, we provide a general and flexible solution to this problem that exploits the remarkable properties of microfluidic circuits with fluid walls─transparent interfaces between culture media and an immiscible fluorocarbon that are easily pierced with pipets. We provide two proofs of concept in which specific cell subpopulations are isolated and recovered: (i) murine macrophages chemotaxing toward complement component 5a and (ii) bacteria (Pseudomonas aeruginosa) in developing biofilms that migrate toward antibiotics. We build circuits in minutes on standard Petri dishes, add cells, pump in laminar streams so molecular diffusion creates attractant gradients, acquire time-lapse images, and isolate desired subpopulations in real time by building fluid walls around migrating cells with an accuracy of tens of micrometers using 3D printed adaptors that convert conventional microscopes into wall-building machines. Our method allows live cells of interest to be easily extracted from microfluidic devices for downstream analyses.
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Affiliation(s)
- Cyril Deroy
- Department
of Engineering Science, Osney Thermo-Fluids Laboratory, University of Oxford, Oxford OX2 0ES, U.K.
| | - James H. R. Wheeler
- Department
of Physics and Astronomy, University of
Sheffield, Sheffield S3 7RH, U.K.
- Department
of Zoology, University of Oxford, Oxford OX1 3SZ, U.K.
- Department
of Biochemistry, University of Oxford, Oxford OX1 3QU, U.K.
| | - Agata N. Rumianek
- Sir
William Dunn School of Pathology, University
of Oxford, Oxford OX1 3RE, U.K.
| | - Peter R. Cook
- Sir
William Dunn School of Pathology, University
of Oxford, Oxford OX1 3RE, U.K.
| | - William M. Durham
- Department
of Physics and Astronomy, University of
Sheffield, Sheffield S3 7RH, U.K.
- Department
of Zoology, University of Oxford, Oxford OX1 3SZ, U.K.
| | - Kevin R. Foster
- Department
of Zoology, University of Oxford, Oxford OX1 3SZ, U.K.
- Department
of Biochemistry, University of Oxford, Oxford OX1 3QU, U.K.
| | - Edmond J. Walsh
- Department
of Engineering Science, Osney Thermo-Fluids Laboratory, University of Oxford, Oxford OX2 0ES, U.K.
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32
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Cabugao KGM, Gushgari-Doyle S, Chacon SS, Wu X, Bhattacharyya A, Bouskill N, Chakraborty R. Characterizing Natural Organic Matter Transformations by Microbial Communities in Terrestrial Subsurface Ecosystems: A Critical Review of Analytical Techniques and Challenges. Front Microbiol 2022; 13:864895. [PMID: 35602028 PMCID: PMC9114703 DOI: 10.3389/fmicb.2022.864895] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 03/28/2022] [Indexed: 11/13/2022] Open
Abstract
Determining the mechanisms, traits, and pathways that regulate microbial transformation of natural organic matter (NOM) is critical to informing our understanding of the microbial impacts on the global carbon cycle. The capillary fringe of subsurface soils is a highly dynamic environment that remains poorly understood. Characterization of organo-mineral chemistry combined with a nuanced understanding of microbial community composition and function is necessary to understand microbial impacts on NOM speciation in the capillary fringe. We present a critical review of the popular analytical and omics techniques used for characterizing complex carbon transformation by microbial communities and focus on how complementary information obtained from the different techniques enable us to connect chemical signatures with microbial genes and pathways. This holistic approach offers a way forward for the comprehensive characterization of the formation, transformation, and mineralization of terrestrial NOM as influenced by microbial communities.
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Affiliation(s)
- Kristine Grace M Cabugao
- Department of Ecology, Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Sara Gushgari-Doyle
- Department of Ecology, Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Stephany S Chacon
- Department of Ecology, Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Xiaoqin Wu
- Department of Ecology, Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Amrita Bhattacharyya
- Department of Ecology, Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Nicholas Bouskill
- Department of Ecology, Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Romy Chakraborty
- Department of Ecology, Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
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33
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Sathicq MB, Sabatino R, Di Cesare A, Eckert EM, Fontaneto D, Rogora M, Corno G. PET particles raise microbiological concerns for human health while tyre wear microplastic particles potentially affect ecosystem services in waters. JOURNAL OF HAZARDOUS MATERIALS 2022; 429:128397. [PMID: 35236044 DOI: 10.1016/j.jhazmat.2022.128397] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 01/28/2022] [Accepted: 01/28/2022] [Indexed: 06/14/2023]
Abstract
Although abundant and chemically peculiar, tyre wear microplastic particles (TWP) and their impact on the microbial communities in water are largely understudied. We tested in laboratory based semi-continuous cultures the impact of TWP and of polyethylene terephthalate (PET) derived particles (following a gradient of relative abundance) on the pathobiome (the group of potential human pathogenic bacteria) of a freshwater microbial community exposed to contamination by the effluent of a urban wastewater treatment plant, for a period of 28 days. We could define the modulated impact of the two types of microplastic particles: while PET does not favour bacterial growth, it offers a refuge to several potential pathogens of allochthonous origin (from the treated sewage effluent), TWP act as an additional carbon source, promoting the development and the massive growth of a biofilm composed by fast-growing bacterial genera including species potentially harmful and competitive in abating biodiversity in surface waters. Our results demonstrate the different ecological role and impact on freshwater environments of TWP and PET particles, and the need to approach the study of this pollutant not as a whole, but considering the origin and the chemical composition of the different particles.
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Affiliation(s)
- Maria Belen Sathicq
- National Research Council of Italy - Water Research Institute (CNR-IRSA) Molecular Ecology Group (MEG), Verbania, Italy
| | - Raffaella Sabatino
- National Research Council of Italy - Water Research Institute (CNR-IRSA) Molecular Ecology Group (MEG), Verbania, Italy
| | - Andrea Di Cesare
- National Research Council of Italy - Water Research Institute (CNR-IRSA) Molecular Ecology Group (MEG), Verbania, Italy
| | - Ester M Eckert
- National Research Council of Italy - Water Research Institute (CNR-IRSA) Molecular Ecology Group (MEG), Verbania, Italy
| | - Diego Fontaneto
- National Research Council of Italy - Water Research Institute (CNR-IRSA) Molecular Ecology Group (MEG), Verbania, Italy
| | - Michela Rogora
- National Research Council of Italy - Water Research Institute (CNR-IRSA), Verbania, Italy
| | - Gianluca Corno
- National Research Council of Italy - Water Research Institute (CNR-IRSA) Molecular Ecology Group (MEG), Verbania, Italy.
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34
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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: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [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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35
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He Y, Bai M, He Y, Wang S, Zhang J, Jiang S, Wang G. Suspended particles are hotspots for pathogen-related bacteria and ARGs in coastal beach waters of northern China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 817:153004. [PMID: 35026254 DOI: 10.1016/j.scitotenv.2022.153004] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 01/04/2022] [Accepted: 01/05/2022] [Indexed: 06/14/2023]
Abstract
Marine suspended particles are unique micro-habitats for diverse microbes and also hotspots of microbially metabolic activities. However, the association of bacterial pathogens, especially those carrying antibiotic resistance genes (ARGs), with these particles remain largely unknown in coastal habitats. This study investigated the distribution of pathogen-related bacteria and ARGs in particle-associated (PA) and free-living (FL) fractions of samples collected at three coastal beaches using NextGen sequencing and qPCR. Suspended particles were found to harbor significantly higher abundances of bacteria of pathogen-related genera and ARGs than their counterparts. Functional analysis of microbial community suggested that antibiotic biosynthetic pathways were also more abundant among PA microbiome comparing to FL microbial community, which further facilitated the spread of ARGs. Additionally, 13 pathogen-related genera co-occurred with ARG in PA fraction while only 2 pathogen-related genera co-occurred with ARGs in FL fraction. Overall, our research revealed suspended particles harbored more abundant pathogen-related genera and ARGs comparing with surrounding waters. Thus, suspended particles are hotspots for pathogen-related genera and ARGs and may pose a greater threat to human health in coastal beach.
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Affiliation(s)
- Yike He
- Center for Marine Environmental Ecology, School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Mohan Bai
- Center for Marine Environmental Ecology, School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China; College of Life Science, Zhejiang University, Hangzhou 310058, China
| | - Yaodong He
- Center for Marine Environmental Ecology, School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Suisui Wang
- Center for Marine Environmental Ecology, School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Jiabo Zhang
- The Eighth Geological Brigade, Hebei Geological Prospecting Bureau, Qinhuangdao 066001, China; Marine Ecological Restoration and Smart Ocean Engineering Research Center of Hebei Province, Qinhuangdao 066001, China
| | - Sunny Jiang
- Department of Civil and Environmental Engineering, University of California at Irvine, CA 92697, USA
| | - Guangyi Wang
- Center for Marine Environmental Ecology, School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China; Qingdao Institute Ocean Engineering of Tianjin University, Qingdao 266237, China.
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36
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Indole decreases the virulence of the bivalve model pathogens Vibrio tasmaniensis LGP32 and Vibrio crassostreae J2-9. Sci Rep 2022; 12:5749. [PMID: 35388110 PMCID: PMC8986839 DOI: 10.1038/s41598-022-09799-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 03/17/2022] [Indexed: 12/13/2022] Open
Abstract
Indole signaling plays an important role in bacterial pathogenesis. In this study, the impact of indole on biofilm formation, swimming and swarming motility were explored in Vibrio tasmaniensis LGP32 and Vibrio crassostreae J2-9, two model pathogens of bivalves. The results showed that indole decreased swimming and swarming motility in both strains, and decreased biofilm formation in V. crassostreae J2-9. Furthermore, indole affected a large number of genes at RNA level, including genes related to metabolism, ABC transporters, flagellar assembly, chemotaxis, and response regulators. Finally, the bacterial virulence towards mussel larvae was decreased by pretreatment with indole in both V. tasmaniensis LGP32 and V. crassostreae J2-9. After 5 days, the survival rate of mussel larvae increased 2.4-fold and 2.8-fold in mussel larvae challenged with V. tasmaniensis LGP32 pretreated with 200 µM and 500 µM indole, respectively. The survival rate of mussel larvae increased 1.5-fold and 1.9-fold in mussel larvae challenged with V. crassostreae J2-9 pretreated with 200 µM and 500 µM indole, respectively. These data indicate that indole has a significant impact on the virulence of V. tasmaniensis LGP32 and V. crassostreae J2-9, and indole signaling could be a promising target for antivirulence therapy.
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Moran MA, Kujawinski EB, Schroer WF, Amin SA, Bates NR, Bertrand EM, Braakman R, Brown CT, Covert MW, Doney SC, Dyhrman ST, Edison AS, Eren AM, Levine NM, Li L, Ross AC, Saito MA, Santoro AE, Segrè D, Shade A, Sullivan MB, Vardi A. Microbial metabolites in the marine carbon cycle. Nat Microbiol 2022; 7:508-523. [PMID: 35365785 DOI: 10.1038/s41564-022-01090-3] [Citation(s) in RCA: 46] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 02/23/2022] [Indexed: 01/08/2023]
Abstract
One-quarter of photosynthesis-derived carbon on Earth rapidly cycles through a set of short-lived seawater metabolites that are generated from the activities of marine phytoplankton, bacteria, grazers and viruses. Here we discuss the sources of microbial metabolites in the surface ocean, their roles in ecology and biogeochemistry, and approaches that can be used to analyse them from chemistry, biology, modelling and data science. Although microbial-derived metabolites account for only a minor fraction of the total reservoir of marine dissolved organic carbon, their flux and fate underpins the central role of the ocean in sustaining life on Earth.
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Affiliation(s)
- Mary Ann Moran
- Department of Marine Sciences, University of Georgia, Athens, GA, USA.
| | - Elizabeth B Kujawinski
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, USA.
| | - William F Schroer
- Department of Marine Sciences, University of Georgia, Athens, GA, USA
| | - Shady A Amin
- Division of Science, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Nicholas R Bates
- Bermuda Institute of Ocean Sciences, St George's, Bermuda.,School of Ocean and Earth Sciences, University of Southampton, Southampton, UK
| | - Erin M Bertrand
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Rogier Braakman
- Departments of Earth, Atmospheric and Planetary Sciences, and Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - C Titus Brown
- Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, Davis, CA, USA
| | - Markus W Covert
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Scott C Doney
- Department of Environmental Sciences, University of Virginia, Charlottesville, VA, USA
| | - Sonya T Dyhrman
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA.,Department of Earth and Environmental Science, Columbia University, Palisades, NY, USA
| | - Arthur S Edison
- Departments of Biochemistry and Genetics, Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - A Murat Eren
- Josephine Bay Paul Center, Marine Biological Laboratory, Woods Hole, MA, USA.,Helmholtz-Institute for Functional Marine Biodiversity (HIFMB), University of Oldenburg, Oldenburg, Germany
| | - Naomi M Levine
- Marine and Environmental Biology, Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Liang Li
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Avena C Ross
- Department of Chemistry, Queen's University, Kingston, Ontario, Canada
| | - Mak A Saito
- Department of Marine Sciences, University of Georgia, Athens, GA, USA
| | - Alyson E Santoro
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA, USA
| | - Daniel Segrè
- Department of Biology and Bioinformatics Program, Boston University, Boston, MA, USA
| | - Ashley Shade
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
| | - Matthew B Sullivan
- Departments of Microbiology and Civil, Environmental, and Geodetic Engineering, and Center of Microbiome Science, The Ohio State University, Columbus, OH, USA
| | - Assaf Vardi
- Department of Plant and Environmental Sciences, The Weizmann Institute of Science, Rehovot, Israel
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38
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Ebrahimi A, Goyal A, Cordero OX. Particle foraging strategies promote microbial diversity in marine environments. eLife 2022; 11:e73948. [PMID: 35289269 PMCID: PMC8956285 DOI: 10.7554/elife.73948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 03/01/2022] [Indexed: 11/26/2022] Open
Abstract
Microbial foraging in patchy environments, where resources are fragmented into particles or pockets embedded in a large matrix, plays a key role in natural environments. In the oceans and freshwater systems, particle-associated bacteria can interact with particle surfaces in different ways: some colonize only during short transients, while others form long-lived, stable colonies. We do not yet understand the ecological mechanisms by which both short- and long-term colonizers can coexist. Here, we address this problem with a mathematical model that explains how marine populations with different detachment rates from particles can stably coexist. In our model, populations grow only while on particles, but also face the increased risk of mortality by predation and sinking. Key to coexistence is the idea that detachment from particles modulates both net growth and mortality, but in opposite directions, creating a trade-off between them. While slow-detaching populations show the highest growth return (i.e., produce more net offspring), they are more susceptible to suffer higher rates of mortality than fast-detaching populations. Surprisingly, fluctuating environments, manifesting as blooms of particles (favoring growth) and predators (favoring mortality) significantly expand the likelihood that populations with different detachment rates can coexist. Our study shows how the spatial ecology of microbes in the ocean can lead to a predictable diversification of foraging strategies and the coexistence of multiple taxa on a single growth-limiting resource.
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Affiliation(s)
- Ali Ebrahimi
- Ralph M. Parsons Laboratory for Environmental Science and Engineering, Department of Civil and Environmental Engineering, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Akshit Goyal
- Physics of Living Systems, Department of Physics, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Otto X Cordero
- Ralph M. Parsons Laboratory for Environmental Science and Engineering, Department of Civil and Environmental Engineering, Massachusetts Institute of TechnologyCambridgeUnited States
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39
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Bahnemann J, Grünberger A. Microfluidics in Biotechnology: Overview and Status Quo. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2022; 179:1-16. [DOI: 10.1007/10_2022_206] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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40
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Gao C, Garren M, Penn K, Fernandez VI, Seymour JR, Thompson JR, Raina JB, Stocker R. Coral mucus rapidly induces chemokinesis and genome-wide transcriptional shifts toward early pathogenesis in a bacterial coral pathogen. THE ISME JOURNAL 2021; 15:3668-3682. [PMID: 34168314 PMCID: PMC8630044 DOI: 10.1038/s41396-021-01024-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 05/12/2021] [Accepted: 05/25/2021] [Indexed: 02/06/2023]
Abstract
Elevated seawater temperatures have contributed to the rise of coral disease mediated by bacterial pathogens, such as the globally distributed Vibrio coralliilyticus, which utilizes coral mucus as a chemical cue to locate stressed corals. However, the physiological events in the pathogens that follow their entry into the coral host environment remain unknown. Here, we present simultaneous measurements of the behavioral and transcriptional responses of V. coralliilyticus BAA-450 incubated in coral mucus. Video microscopy revealed a strong and rapid chemokinetic behavioral response by the pathogen, characterized by a two-fold increase in average swimming speed within 6 min of coral mucus exposure. RNA sequencing showed that this bacterial behavior was accompanied by an equally rapid differential expression of 53% of the genes in the V. coralliilyticus genome. Specifically, transcript abundance 10 min after mucus exposure showed upregulation of genes involved in quorum sensing, biofilm formation, and nutrient metabolism, and downregulation of flagella synthesis and chemotaxis genes. After 60 min, we observed upregulation of genes associated with virulence, including zinc metalloproteases responsible for causing coral tissue damage and algal symbiont photoinactivation, and secretion systems that may export toxins. Together, our results suggest that V. coralliilyticus employs a suite of behavioral and transcriptional responses to rapidly shift into a distinct infection mode within minutes of exposure to the coral microenvironment.
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Affiliation(s)
- Cherry Gao
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Civil and Environmental Engineering, Ralph M. Parsons Laboratory, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Civil, Environmental and Geomatic Engineering, Institute of Environmental Engineering, ETH Zurich, Zurich, Switzerland
| | - Melissa Garren
- Working Ocean Strategies LLC, Carmel, CA, USA
- Department of Applied Environmental Science, California State University Monterey Bay, Seaside, CA, USA
| | - Kevin Penn
- Department of Civil and Environmental Engineering, Ralph M. Parsons Laboratory, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Vicente I Fernandez
- Department of Civil, Environmental and Geomatic Engineering, Institute of Environmental Engineering, ETH Zurich, Zurich, Switzerland
| | - Justin R Seymour
- Climate Change Cluster (C3), University of Technology Sydney, Ultimo, NSW, Australia
| | - Janelle R Thompson
- Singapore Center for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- Asian School of the Environment, Nanyang Technological University, Singapore, Singapore
| | - Jean-Baptiste Raina
- Climate Change Cluster (C3), University of Technology Sydney, Ultimo, NSW, Australia
| | - Roman Stocker
- Department of Civil, Environmental and Geomatic Engineering, Institute of Environmental Engineering, ETH Zurich, Zurich, Switzerland.
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41
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Daly G, Perrin E, Viti C, Fondi M, Adessi A. Scaling down the microbial loop: data-driven modelling of growth interactions in a diatom-bacterium co-culture. ENVIRONMENTAL MICROBIOLOGY REPORTS 2021; 13:945-954. [PMID: 34541831 PMCID: PMC9293018 DOI: 10.1111/1758-2229.13010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 09/01/2021] [Accepted: 09/03/2021] [Indexed: 06/13/2023]
Abstract
An intricate set of interactions characterizes marine ecosystems. One of the most important is represented by the microbial loop, which includes the exchange of dissolved organic matter (DOM) from phototrophic organisms to heterotrophic bacteria. Here, it can be used as the major carbon and energy source. This interaction is one of the foundations of the entire ocean food-web. The carbon fixed by phytoplankton can be redirected to bacteria in two main ways; either (i) bacteria feed on dead phytoplankton cells or (ii) DOM is actively released by phytoplankton (a process resulting in up to 50% of the fixed carbon leaving the cell). Here, we have set up a co-culture of the diatom Phaeodactylum tricornutum and the chemoheterotrophic bacterium Pseudoalteromonas haloplanktis TAC125 and used this system to study the interactions between these two representatives of the microbial loop. We show that the bacterium can thrive on diatom-derived carbon and that this growth can be sustained by both diatom dead cells and diatom-released compounds. These observations were formalized in a network of putative interactions between P. tricornutum and P. haloplanktis and implemented in a model that reproduces the observed co-culture dynamics, revealing an overall accuracy of our hypotheses in explaining the experimental data.
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Affiliation(s)
- Giulia Daly
- Department of Agriculture, Food, Environment and ForestryUniversity of Florence, Piazzale delle CascineFlorence18Italy
| | - Elena Perrin
- Department of BiologyUniversity of FlorenceVia Madonna del Piano 6, Sesto F.no, FlorenceItaly
| | - Carlo Viti
- Department of Agriculture, Food, Environment and ForestryUniversity of Florence, Piazzale delle CascineFlorence18Italy
| | - Marco Fondi
- Department of BiologyUniversity of FlorenceVia Madonna del Piano 6, Sesto F.no, FlorenceItaly
- Centro Interdipartimentale per lo Studio delle Dinamiche ComplesseUniversity of FlorenceFlorenceItaly
| | - Alessandra Adessi
- Department of Agriculture, Food, Environment and ForestryUniversity of Florence, Piazzale delle CascineFlorence18Italy
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42
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Host genotype structures the microbiome of a globally dispersed marine phytoplankton. Proc Natl Acad Sci U S A 2021; 118:2105207118. [PMID: 34810258 PMCID: PMC8640791 DOI: 10.1073/pnas.2105207118] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/08/2021] [Indexed: 11/18/2022] Open
Abstract
Microscale interactions between marine phytoplankton and their bacterial microbiomes can influence ecosystem functioning and global biogeochemical cycling through complex exchanges of metabolites and sophisticated ecological processes. Previous investigation of the phytoplankton microbiome has not focused on the role of a host’s underlying genetic background. Through examination of a single phytoplankton species’ microbiome across the global ocean, we found that host genotype strongly influenced microbiome community composition, with associations that potentially persist across generations and ocean basins but assemble rapidly (within days). The long-term association of microbiomes with host genetic background could explain the evolution and maintenance of intricate phytoplankton–bacteria interactions. Phytoplankton support complex bacterial microbiomes that rely on phytoplankton-derived extracellular compounds and perform functions necessary for algal growth. Recent work has revealed sophisticated interactions and exchanges of molecules between specific phytoplankton–bacteria pairs, but the role of host genotype in regulating those interactions is unknown. Here, we show how phytoplankton microbiomes are shaped by intraspecific genetic variation in the host using global environmental isolates of the model phytoplankton host Thalassiosira rotula and a laboratory common garden experiment. A set of 81 environmental T. rotula genotypes from three ocean basins and eight genetically distinct populations did not reveal a core microbiome. While no single bacterial phylotype was shared across all genotypes, we found strong genotypic influence of T. rotula, with microbiomes associating more strongly with host genetic population than with environmental factors. The microbiome association with host genetic population persisted across different ocean basins, suggesting that microbiomes may be associated with host populations for decades. To isolate the impact of host genotype on microbiomes, a common garden experiment using eight genotypes from three distinct host populations again found that host genotype influenced microbial community composition, suggesting that a process we describe as genotypic filtering, analogous to environmental filtering, shapes phytoplankton microbiomes. In both the environmental and laboratory studies, microbiome variation between genotypes suggests that other factors influenced microbiome composition but did not swamp the dominant signal of host genetic background. The long-term association of microbiomes with specific host genotypes reveals a possible mechanism explaining the evolution and maintenance of complex phytoplankton–bacteria chemical exchanges.
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43
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Colin R, Ni B, Laganenka L, Sourjik V. Multiple functions of flagellar motility and chemotaxis in bacterial physiology. FEMS Microbiol Rev 2021; 45:fuab038. [PMID: 34227665 PMCID: PMC8632791 DOI: 10.1093/femsre/fuab038] [Citation(s) in RCA: 113] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 07/02/2021] [Indexed: 12/13/2022] Open
Abstract
Most swimming bacteria are capable of following gradients of nutrients, signaling molecules and other environmental factors that affect bacterial physiology. This tactic behavior became one of the most-studied model systems for signal transduction and quantitative biology, and underlying molecular mechanisms are well characterized in Escherichia coli and several other model bacteria. In this review, we focus primarily on less understood aspect of bacterial chemotaxis, namely its physiological relevance for individual bacterial cells and for bacterial populations. As evident from multiple recent studies, even for the same bacterial species flagellar motility and chemotaxis might serve multiple roles, depending on the physiological and environmental conditions. Among these, finding sources of nutrients and more generally locating niches that are optimal for growth appear to be one of the major functions of bacterial chemotaxis, which could explain many chemoeffector preferences as well as flagellar gene regulation. Chemotaxis might also generally enhance efficiency of environmental colonization by motile bacteria, which involves intricate interplay between individual and collective behaviors and trade-offs between growth and motility. Finally, motility and chemotaxis play multiple roles in collective behaviors of bacteria including swarming, biofilm formation and autoaggregation, as well as in their interactions with animal and plant hosts.
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Affiliation(s)
- Remy Colin
- Max Planck Institute for Terrestrial Microbiology & Center for Synthetic Microbiology (SYNMIKRO), Karl-von-Frisch Strasse 16, Marburg D-35043, Germany
| | - Bin Ni
- Max Planck Institute for Terrestrial Microbiology & Center for Synthetic Microbiology (SYNMIKRO), Karl-von-Frisch Strasse 16, Marburg D-35043, Germany
- College of Resources and Environmental Science, National Academy of Agriculture Green Development, China Agricultural University, Yuanmingyuan Xilu No. 2, Beijing 100193, China
| | - Leanid Laganenka
- Institute of Microbiology, D-BIOL, ETH Zürich, Vladimir-Prelog-Weg 4, Zürich 8093, Switzerland
| | - Victor Sourjik
- Max Planck Institute for Terrestrial Microbiology & Center for Synthetic Microbiology (SYNMIKRO), Karl-von-Frisch Strasse 16, Marburg D-35043, Germany
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44
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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] [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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45
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Gralka M, Szabo R, Stocker R, Cordero OX. Trophic Interactions and the Drivers of Microbial Community Assembly. Curr Biol 2021; 30:R1176-R1188. [PMID: 33022263 DOI: 10.1016/j.cub.2020.08.007] [Citation(s) in RCA: 107] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Despite numerous surveys of gene and species content in heterotrophic microbial communities, such as those found in animal guts, oceans, or soils, it is still unclear whether there are generalizable biological or ecological processes that control their dynamics and function. Here, we review experimental and theoretical advances to argue that networks of trophic interactions, in which the metabolic excretions of one species are the primary resource for another, constitute the central drivers of microbial community assembly. Trophic interactions emerge from the deconstruction of complex forms of organic matter into a wealth of smaller metabolic intermediates, some of which are released to the environment and serve as a nutritional buffet for the community. The structure of the emergent trophic network and the rate at which primary resources are supplied control many features of microbial community assembly, including the relative contributions of competition and cooperation and the emergence of alternative community states. Viewing microbial community assembly through the lens of trophic interactions also has important implications for the spatial dynamics of communities as well as the functional redundancy of taxonomic groups. Given the ubiquity of trophic interactions across environments, they impart a common logic that can enable the development of a more quantitative and predictive microbial community ecology.
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Affiliation(s)
- Matti Gralka
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Rachel Szabo
- Microbiology Graduate Program, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Roman Stocker
- Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich 8093, Switzerland
| | - Otto X Cordero
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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Zhang S, Yang Q, Defoirdt T. Indole decreases the virulence of pathogenic vibrios belonging to the Harveyi clade. J Appl Microbiol 2021; 132:167-176. [PMID: 34297464 DOI: 10.1111/jam.15227] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 06/28/2021] [Accepted: 07/16/2021] [Indexed: 11/29/2022]
Abstract
AIM Indole is a signaling molecule secreted by over 85 species of bacteria, including several Vibrio species, and it has been reported to affect different bacterial phenotypes such as biofilm formation, motility, and virulence. In this study, we aimed at investigating the inter-strain variability of the effect of indole in 12 different strains belonging to the Harveyi clade of vibrios. METHODS AND RESULTS Indole reduced the virulence of all strains towards gnotobiotic brine shrimp larvae. The survival rate of brine shrimp larvae challenged with vibrios pretreated with indole was increased by 1.3-fold to 1.8-fold. Additionally, indole significantly decreased the biofilm formation in all of the strains, decreased the swimming motility in eight of the strains, and decreased swarming motility in five of the strains. When cultured in the presence of exogenous indole, the mRNA level of the pirA and pirB toxin genes were down-regulated to 65% and 46%, and to 62% and 55% in the AHPND-causing strains Vibrio parahaemolyticus M0904 and Vibrio campbellii S01, respectively. CONCLUSIONS These data indicate that indole has a significant impact on the virulence of different strains belonging to the Harveyi clade of vibrios. SIGNIFICANCE AND IMPACT OF THE STUDY Our results suggest that indole signaling is a valid target for the development of novel therapeutics in order to control infections caused by Harveyi clade vibrios in aquaculture.
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Affiliation(s)
- Shanshan Zhang
- Center for Microbial Ecology and Technology (CMET), Ghent University, Gent, Belgium
| | - Qian Yang
- Center for Microbial Ecology and Technology (CMET), Ghent University, Gent, Belgium
| | - Tom Defoirdt
- Center for Microbial Ecology and Technology (CMET), Ghent University, Gent, Belgium
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Karin O, Alon U. Temporal fluctuations in chemotaxis gain implement a simulated-tempering strategy for efficient navigation in complex environments. iScience 2021; 24:102796. [PMID: 34345809 PMCID: PMC8319753 DOI: 10.1016/j.isci.2021.102796] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 03/29/2021] [Accepted: 06/24/2021] [Indexed: 12/01/2022] Open
Abstract
Bacterial chemotaxis is a major testing ground for systems biology, including the role of fluctuations and individual variation. Individual bacteria vary in their tumbling frequency and adaptation time. Recently, large cell-cell variation was also discovered in chemotaxis gain, which determines the sensitivity of the tumbling rate to attractant gradients. Variation in gain is puzzling, because low gain impairs chemotactic velocity. Here, we provide a functional explanation for gain variation by establishing a formal analogy between chemotaxis and algorithms for sampling probability distributions. We show that temporal fluctuations in gain implement simulated tempering, which allows sampling of attractant distributions with many local peaks. Periods of high gain allow bacteria to detect and climb gradients quickly, and periods of low gain allow them to move to new peaks. Gain fluctuations thus allow bacteria to thrive in complex environments, and more generally they may play an important functional role for organism navigation.
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Affiliation(s)
- Omer Karin
- Department Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
- Wellcome Trust–Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge, UK
- Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Cambridge, UK
| | - Uri Alon
- Department Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
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48
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Klawonn I, Van den Wyngaert S, Parada AE, Arandia-Gorostidi N, Whitehouse MJ, Grossart HP, Dekas AE. Characterizing the "fungal shunt": Parasitic fungi on diatoms affect carbon flow and bacterial communities in aquatic microbial food webs. Proc Natl Acad Sci U S A 2021; 118:e2102225118. [PMID: 34074785 PMCID: PMC8201943 DOI: 10.1073/pnas.2102225118] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Microbial interactions in aquatic environments profoundly affect global biogeochemical cycles, but the role of microparasites has been largely overlooked. Using a model pathosystem, we studied hitherto cryptic interactions between microparasitic fungi (chytrid Rhizophydiales), their diatom host Asterionella, and cell-associated and free-living bacteria. We analyzed the effect of fungal infections on microbial abundances, bacterial taxonomy, cell-to-cell carbon transfer, and cell-specific nitrate-based growth using microscopy (e.g., fluorescence in situ hybridization), 16S rRNA gene amplicon sequencing, and secondary ion mass spectrometry. Bacterial abundances were 2 to 4 times higher on individual fungal-infected diatoms compared to healthy diatoms, particularly involving Burkholderiales. Furthermore, taxonomic compositions of both diatom-associated and free-living bacteria were significantly different between noninfected and fungal-infected cocultures. The fungal microparasite, including diatom-associated sporangia and free-swimming zoospores, derived ∼100% of their carbon content from the diatom. By comparison, transfer efficiencies of photosynthetic carbon were lower to diatom-associated bacteria (67 to 98%), with a high cell-to-cell variability, and even lower to free-living bacteria (32%). Likewise, nitrate-based growth for the diatom and fungi was synchronized and faster than for diatom-associated and free-living bacteria. In a natural lacustrine system, where infection prevalence reached 54%, we calculated that 20% of the total diatom-derived photosynthetic carbon was shunted to the parasitic fungi, which can be grazed by zooplankton, thereby accelerating carbon transfer to higher trophic levels and bypassing the microbial loop. The herein termed "fungal shunt" can thus significantly modify the fate of photosynthetic carbon and the nature of phytoplankton-bacteria interactions, with implications for diverse pelagic food webs and global biogeochemical cycles.
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Affiliation(s)
- Isabell Klawonn
- Department of Earth System Science, Stanford University, Stanford, CA 94305;
| | - Silke Van den Wyngaert
- Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, 12587 Berlin, Germany
| | - Alma E Parada
- Department of Earth System Science, Stanford University, Stanford, CA 94305
| | | | - Martin J Whitehouse
- Department of Geosciences, Swedish Museum of Natural History, 104 05 Stockholm, Sweden
| | - Hans-Peter Grossart
- Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, 12587 Berlin, Germany
- Institute of Biochemistry and Biology, Potsdam University, 14476 Potsdam, Germany
| | - Anne E Dekas
- Department of Earth System Science, Stanford University, Stanford, CA 94305;
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49
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Small sinking particles control anammox rates in the Peruvian oxygen minimum zone. Nat Commun 2021; 12:3235. [PMID: 34050175 PMCID: PMC8163745 DOI: 10.1038/s41467-021-23340-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 04/26/2021] [Indexed: 11/15/2022] Open
Abstract
Anaerobic oxidation of ammonium (anammox) in oxygen minimum zones (OMZs) is a major pathway of oceanic nitrogen loss. Ammonium released from sinking particles has been suggested to fuel this process. During cruises to the Peruvian OMZ in April–June 2017 we found that anammox rates are strongly correlated with the volume of small particles (128–512 µm), even though anammox bacteria were not directly associated with particles. This suggests that the relationship between anammox rates and particles is related to the ammonium released from particles by remineralization. To investigate this, ammonium release from particles was modelled and theoretical encounters of free-living anammox bacteria with ammonium in the particle boundary layer were calculated. These results indicated that small sinking particles could be responsible for ~75% of ammonium release in anoxic waters and that free-living anammox bacteria frequently encounter ammonium in the vicinity of smaller particles. This indicates a so far underestimated role of abundant, slow-sinking small particles in controlling oceanic nutrient budgets, and furthermore implies that observations of the volume of small particles could be used to estimate N-loss across large areas. Up to 40% of the ocean’s fixed nitrogen is lost in oxygen minimum zones (OMZs) by anammox, but despite the importance of this process, nitrogen loss patterns in OMZs are difficult to predict. Here the authors show that ammonium release from small particles is a major control of anammox in the Peruvian OMZ.
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50
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Li SW, Lin PH, Ho TY, Hsieh CH, Sun CL. Change in rheotactic behavior patterns of dinoflagellates in response to different microfluidic environments. Sci Rep 2021; 11:11105. [PMID: 34045568 PMCID: PMC8160355 DOI: 10.1038/s41598-021-90622-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 05/12/2021] [Indexed: 11/15/2022] Open
Abstract
Plankton live in dynamic fluid environments. Their ability to change in response to different hydrodynamic cues is critical to their energy allocation and resource uptake. This study used a microfluidic device to evaluate the rheotactic behaviors of a model dinoflagellate species, Karlodinium veneficum, in different flow conditions. Although dinoflagellates experienced forced alignment in strong shear (i.e. “trapping”), fluid straining did not play a decisive role in their rheotactic movements. Moderate hydrodynamic magnitude (20 < |uf| < 40 µm s−1) was found to induce an orientation heading towards an oncoming current (positive rheotaxis), as dinoflagellates switched to cross-flow swimming when flow speed exceeded 50 µm s−1. Near the sidewalls of the main channel, the steric mechanism enabled dinoflagellates to adapt upstream orientation through vertical migration. Under oscillatory flow, however, positive rheotaxis dominated with occasional diversion. The varying flow facilitated upstream exploration with directional controlling, through which dinoflagellates exhibited avoidance of both large-amplitude perturbance and very stagnant zones. In the mixed layer where water is not steady, these rheotactic responses could lead to spatial heterogeneity of dinoflagellates. The outcome of this study helps clarify the interaction between swimming behaviors of dinoflagellates and the hydrodynamic environment they reside in.
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Affiliation(s)
- Si-Wei Li
- Department of Mechanical Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Po-Hsu Lin
- Department of Mechanical Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Tung-Yuan Ho
- Institute of Oceanography, National Taiwan University, Taipei, 10617, Taiwan.,Research Center for Environmental Changes, Academia Sinica, Taipei, 11529, Taiwan
| | - Chih-Hao Hsieh
- Institute of Oceanography, National Taiwan University, Taipei, 10617, Taiwan.,Research Center for Environmental Changes, Academia Sinica, Taipei, 11529, Taiwan.,Institute of Ecology and Evolutionary Biology and Department of Life Science, National Taiwan University, Taipei, 10617, Taiwan.,Mathematics Division, National Center for Theoretical Sciences, Taipei, 10617, Taiwan
| | - Chen-Li Sun
- Department of Mechanical Engineering, National Taiwan University, Taipei, 10617, Taiwan.
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