1
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Wang X, Guo N, Zhang Y, Wang G, Shi K. Cross-protection and cross-feeding between Enterobacter and Comamonas promoting their coexistence and cadmium tolerance in Oryza sativa L. Microbiol Res 2024; 286:127806. [PMID: 38924817 DOI: 10.1016/j.micres.2024.127806] [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: 01/27/2024] [Revised: 04/13/2024] [Accepted: 06/06/2024] [Indexed: 06/28/2024]
Abstract
Metabolic cross-feeding is a pervasive interaction between bacteria to acquire novel phenotypes. However, our current understanding of the survival mechanism for cross-feeding in cocultured bacterial biofilms under heavy-metal conditions remains limited. Herein, we found that Comamonas sp. A23 produces L-phenylalanine to activate the L-phenylalanine degradation pathway in Enterobacter sp. A11, enhancing biofilm formation and cadmium [Cd(II)] immobilization in A11. The genes responsible for L-phenylalanine-degradation (paaK) and cell attachment and aggregation (csgAD) are essential for biofilm formation and Cd(II) immobilization in A11 induced by L-phenylalanine. The augmentation of A11 biofilms, in turn, protects A23 under Cd(II) and H2O2 stresses. The plant-based experiments demonstrate that the induction of two rice Cd(II) transporters, OsCOPT4 and OsBCP1, by A11 and A23 enhances rice resistance against Cd(II) and H2O2 stresses. Overall, our findings unveil the mutual dependence between bacteria and rice on L-phenylalanine cross-feeding for survival under abiotic stress.
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Affiliation(s)
- Xing Wang
- National Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Naijiang Guo
- National Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Yao Zhang
- National Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Gejiao Wang
- National Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Kaixiang Shi
- National Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China.
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2
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Robertson JM, Garza EA, Stubbusch AKM, Dupont CL, Hwa T, Held NA. Marine bacteria Alteromonas spp. require UDP-glucose-4-epimerase for aggregation and production of sticky exopolymer. mBio 2024:e0003824. [PMID: 38958440 DOI: 10.1128/mbio.00038-24] [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: 01/06/2024] [Accepted: 05/23/2024] [Indexed: 07/04/2024] Open
Abstract
The physiology and ecology of particle-associated marine bacteria are of growing interest, but our knowledge of their aggregation behavior and mechanisms controlling their association with particles remains limited. We have found that a particle-associated isolate, Alteromonas sp. ALT199 strain 4B03, and the related type-strain A. macleodii 27126 both form large (>500 μm) aggregates while growing in rich medium. A non-clumping variant (NCV) of 4B03 spontaneously arose in the lab, and whole-genome sequencing revealed a partial deletion in the gene encoding UDP-glucose-4-epimerase (galEΔ308-324). In 27126, a knock-out of galE (ΔgalE::kmr) resulted in a loss of aggregation, mimicking the NCV. Microscopic analysis shows that both 4B03 and 27126 rapidly form large aggregates, whereas their respective galE mutants remain primarily as single planktonic cells or clusters of a few cells. Strains 4B03 and 27126 also form aggregates with chitin particles, but their galE mutants do not. Alcian Blue staining shows that 4B03 and 27126 produce large transparent exopolymer particles (TEP), but their galE mutants are deficient in this regard. This study demonstrates the capabilities of cell-cell aggregation, aggregation of chitin particles, and production of TEP in strains of Alteromonas, a widespread particle-associated genus of heterotrophic marine bacteria. A genetic requirement for galE is evident for each of the above capabilities, expanding the known breadth of requirement for this gene in biofilm-related processes. IMPORTANCE Heterotrophic marine bacteria have a central role in the global carbon cycle. Well-known for releasing CO2 by decomposition and respiration, they may also contribute to particulate organic matter (POM) aggregation, which can promote CO2 sequestration via the formation of marine snow. We find that two members of the prevalent particle-associated genus Alteromonas can form aggregates comprising cells alone or cells and chitin particles, indicating their ability to drive POM aggregation. In line with their multivalent aggregation capability, both strains produce TEP, an excreted polysaccharide central to POM aggregation in the ocean. We demonstrate a genetic requirement for galE in aggregation and large TEP formation, building our mechanistic understanding of these aggregative capabilities. These findings point toward a role for heterotrophic bacteria in POM aggregation in the ocean and support broader efforts to understand bacterial controls on the global carbon cycle based on microbial activities, community structure, and meta-omic profiling.
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Affiliation(s)
- Jacob M Robertson
- Division of Biological Sciences, UC San Diego, La Jolla, California, USA
| | - Erin A Garza
- Microbial and Environmental Genomics, J Craig Venter Institute, La Jolla, California, USA
| | - Astrid K M Stubbusch
- Department of Environmental Systems Science, Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, Zürich, Switzerland
- Department of Environmental Microbiology, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
- Department of Earth Sciences, Geological Institute, ETH Zurich, Zurich, Switzerland
| | - Christopher L Dupont
- Microbial and Environmental Genomics, J Craig Venter Institute, La Jolla, California, USA
| | - Terence Hwa
- Division of Biological Sciences, UC San Diego, La Jolla, California, USA
- Department of Physics, UC San Diego, La Jolla, California, USA
| | - Noelle A Held
- Department of Environmental Systems Science, Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, Zürich, Switzerland
- Department of Environmental Microbiology, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
- Department of Biological Sciences, Marine and Environmental Biology Section, University of Southern California, Los Angeles, California, USA
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3
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Huang Y, Mukherjee A, Schink S, Benites NC, Basan M. Evolution and stability of complex microbial communities driven by trade-offs. Mol Syst Biol 2024:10.1038/s44320-024-00051-8. [PMID: 38961275 DOI: 10.1038/s44320-024-00051-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Revised: 06/18/2024] [Accepted: 06/20/2024] [Indexed: 07/05/2024] Open
Abstract
Microbial communities are ubiquitous in nature and play an important role in ecology and human health. Cross-feeding is thought to be core to microbial communities, though it remains unclear precisely why it emerges. Why have multi-species microbial communities evolved in many contexts and what protects microbial consortia from invasion? Here, we review recent insights into the emergence and stability of coexistence in microbial communities. A particular focus is the long-term evolutionary stability of coexistence, as observed for microbial communities that spontaneously evolved in the E. coli long-term evolution experiment (LTEE). We analyze these findings in the context of recent work on trade-offs between competing microbial objectives, which can constitute a mechanistic basis for the emergence of coexistence. Coexisting communities, rather than monocultures of the 'fittest' single strain, can form stable endpoints of evolutionary trajectories. Hence, the emergence of coexistence might be an obligatory outcome in the evolution of microbial communities. This implies that rather than embodying fragile metastable configurations, some microbial communities can constitute formidable ecosystems that are difficult to disrupt.
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Affiliation(s)
- Yanqing Huang
- Harvard Medical School, Department of Systems Biology, Boston, USA
| | - Avik Mukherjee
- Harvard Medical School, Department of Systems Biology, Boston, USA
| | - Severin Schink
- Harvard Medical School, Department of Systems Biology, Boston, USA
| | | | - Markus Basan
- Harvard Medical School, Department of Systems Biology, Boston, USA.
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4
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Silverstein MR, Bhatnagar JM, Segrè D. Metabolic complexity drives divergence in microbial communities. Nat Ecol Evol 2024:10.1038/s41559-024-02440-6. [PMID: 38956426 DOI: 10.1038/s41559-024-02440-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 05/14/2024] [Indexed: 07/04/2024]
Abstract
Microbial communities are shaped by environmental metabolites, but the principles that govern whether different communities will converge or diverge in any given condition remain unknown, posing fundamental questions about the feasibility of microbiome engineering. Here we studied the longitudinal assembly dynamics of a set of natural microbial communities grown in laboratory conditions of increasing metabolic complexity. We found that different microbial communities tend to become similar to each other when grown in metabolically simple conditions, but they diverge in composition as the metabolic complexity of the environment increases, a phenomenon we refer to as the divergence-complexity effect. A comparative analysis of these communities revealed that this divergence is driven by community diversity and by the assortment of specialist taxa capable of degrading complex metabolites. An ecological model of community dynamics indicates that the hierarchical structure of metabolism itself, where complex molecules are enzymatically degraded into progressively simpler ones that then participate in cross-feeding between community members, is necessary and sufficient to recapitulate our experimental observations. In addition to helping understand the role of the environment in community assembly, the divergence-complexity effect can provide insight into which environments support multiple community states, enabling the search for desired ecosystem functions towards microbiome engineering applications.
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Affiliation(s)
- Michael R Silverstein
- Bioinformatics Program, Faculty of Computing and Data Science, Boston University, Boston, MA, USA
- Biological Design Center, Boston University, Boston, MA, USA
| | - Jennifer M Bhatnagar
- Bioinformatics Program, Faculty of Computing and Data Science, Boston University, Boston, MA, USA
- Department of Biology, Boston University, Boston, MA, USA
| | - Daniel Segrè
- Bioinformatics Program, Faculty of Computing and Data Science, Boston University, Boston, MA, USA.
- Biological Design Center, Boston University, Boston, MA, USA.
- Department of Biology, Boston University, Boston, MA, USA.
- Department of Biomedical Engineering and Department of Physics, Boston University, Boston, MA, USA.
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5
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Ho PY, Nguyen TH, Sanchez JM, DeFelice BC, Huang KC. Resource competition predicts assembly of gut bacterial communities in vitro. Nat Microbiol 2024; 9:1036-1048. [PMID: 38486074 DOI: 10.1038/s41564-024-01625-w] [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: 04/30/2023] [Accepted: 01/26/2024] [Indexed: 04/06/2024]
Abstract
Microbial community dynamics arise through interspecies interactions, including resource competition, cross-feeding and pH modulation. The individual contributions of these mechanisms to community structure are challenging to untangle. Here we develop a framework to estimate multispecies niche overlaps by combining metabolomics data of individual species, growth measurements in spent media and mathematical models. We applied our framework to an in vitro model system comprising 15 human gut commensals in complex media and showed that a simple model of resource competition accounted for most pairwise interactions. Next, we built a coarse-grained consumer-resource model by grouping metabolomic features depleted by the same set of species and showed that this model predicted the composition of 2-member to 15-member communities with reasonable accuracy. Furthermore, we found that incorporation of cross-feeding and pH-mediated interactions improved model predictions of species coexistence. Our theoretical model and experimental framework can be applied to characterize interspecies interactions in bacterial communities in vitro.
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Affiliation(s)
- Po-Yi Ho
- Department of Bioengineering, Stanford University, Stanford, CA, USA.
- School of Engineering, Westlake University, Hangzhou, China.
| | - Taylor H Nguyen
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | | | | | - Kerwyn Casey Huang
- Department of Bioengineering, Stanford University, Stanford, CA, USA.
- Chan Zuckerberg Biohub, San Francisco, CA, USA.
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA.
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6
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Luo J, Li J, Wang C, Li M, Hu S, Lu K, Wang G. Rubellicoccus peritrichatus gen. nov., sp. nov., isolated from crustose coralline algae in a coral aquarium. Int J Syst Evol Microbiol 2024; 74. [PMID: 38568201 DOI: 10.1099/ijsem.0.006325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2024] Open
Abstract
A Gram-stain-negative, motile, aerobic, non-spore-forming coccus, designated strain CR14T, was isolated from crustose coralline algae. Cells grew at 20-30 °C (optimum, 25 °C), at pH 6-9 (optimum, pH 7.6) and with NaCl concentrations of 0.5-9 % (w/v; optimum, 2-4 %). Global alignment based on 16S rRNA gene sequences indicated strain CR14T is closest to Ruficoccus amylovorans JCM 31066T with an identity of 92 %. The average nucleotide identity and average amino acid identity values between CR14T and R. amylovorans JCM 31066T were 68.4 and 59.9 %, respectively. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain CR14T forms an independent branch within the family Cerasicoccaeae, which was consistent with the phylogenomic results. The sole isoprenoid quinone was MK-7. The major fatty acids were C14 : 0, C18 : 1 ω9c, C19 : 0 cyc 9,10 DMA, C16 : 0, and C18 : 2 ω6c. The major cellular polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, and two unidentified lipids. The genome DNA G+C content was 48.7 mol%. Based on morphological, physiological and chemotaxonomic characteristics, strain CR14T is suggested to represent a novel species in a new genus, for which the name Rubellicoccus peritrichatus gen. nov., sp. nov. is proposed. The type strain is CR14T (=MCCC 1K03845T=KCTC 72139T).
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Affiliation(s)
- Jixin Luo
- Guangxi Key Laboratory on the Study of Coral Reefs in the South China Sea, Nanning 530004, PR China
- School of Marine Sciences, Guangxi University, Nanning 530004, PR China
| | - Jin Li
- Guangxi Key Laboratory on the Study of Coral Reefs in the South China Sea, Nanning 530004, PR China
- School of Marine Sciences, Guangxi University, Nanning 530004, PR China
| | - Chenyan Wang
- Guangxi Key Laboratory on the Study of Coral Reefs in the South China Sea, Nanning 530004, PR China
- School of Marine Sciences, Guangxi University, Nanning 530004, PR China
| | - Mi Li
- Guangxi Key Laboratory on the Study of Coral Reefs in the South China Sea, Nanning 530004, PR China
- School of Marine Sciences, Guangxi University, Nanning 530004, PR China
| | - Siyu Hu
- Guangxi Key Laboratory on the Study of Coral Reefs in the South China Sea, Nanning 530004, PR China
- School of Marine Sciences, Guangxi University, Nanning 530004, PR China
| | - Kun Lu
- Guangxi Key Laboratory on the Study of Coral Reefs in the South China Sea, Nanning 530004, PR China
- School of Marine Sciences, Guangxi University, Nanning 530004, PR China
| | - Guanghua Wang
- Guangxi Key Laboratory on the Study of Coral Reefs in the South China Sea, Nanning 530004, PR China
- School of Marine Sciences, Guangxi University, Nanning 530004, PR China
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7
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Narla AV, Hwa T, Murugan A. Dynamic coexistence driven by physiological transitions in microbial communities. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.10.575059. [PMID: 38260536 PMCID: PMC10802591 DOI: 10.1101/2024.01.10.575059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Microbial ecosystems are commonly modeled by fixed interactions between species in steady exponential growth states. However, microbes often modify their environments so strongly that they are forced out of the exponential state into stressed or non-growing states. Such dynamics are typical of ecological succession in nature and serial-dilution cycles in the laboratory. Here, we introduce a phenomenological model, the Community State model, to gain insight into the dynamic coexistence of microbes due to changes in their physiological states. Our model bypasses specific interactions (e.g., nutrient starvation, stress, aggregation) that lead to different combinations of physiological states, referred to collectively as "community states", and modeled by specifying the growth preference of each species along a global ecological coordinate, taken here to be the total community biomass density. We identify three key features of such dynamical communities that contrast starkly with steady-state communities: increased tolerance of community diversity to fast growth rates of species dominating different community states, enhanced community stability through staggered dominance of different species in different community states, and increased requirement on growth dominance for the inclusion of late-growing species. These features, derived explicitly for simplified models, are proposed here to be principles aiding the understanding of complex dynamical communities. Our model shifts the focus of ecosystem dynamics from bottom-up studies based on idealized inter-species interaction to top-down studies based on accessible macroscopic observables such as growth rates and total biomass density, enabling quantitative examination of community-wide characteristics.
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Affiliation(s)
| | - Terence Hwa
- Department of Physics, University of California, San Diego
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8
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Narla AV, Hwa T, Murugan A. Dynamic coexistence driven by physiological transitions in microbial communities. ARXIV 2024:arXiv:2401.02556v1. [PMID: 38259349 PMCID: PMC10802671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Microbial ecosystems are commonly modeled by fixed interactions between species in steady exponential growth states. However, microbes often modify their environments so strongly that they are forced out of the exponential state into stressed or non-growing states. Such dynamics are typical of ecological succession in nature and serial-dilution cycles in the laboratory. Here, we introduce a phenomenological model, the Community State model, to gain insight into the dynamic coexistence of microbes due to changes in their physiological states. Our model bypasses specific interactions (e.g., nutrient starvation, stress, aggregation) that lead to different combinations of physiological states, referred to collectively as "community states", and modeled by specifying the growth preference of each species along a global ecological coordinate, taken here to be the total community biomass density. We identify three key features of such dynamical communities that contrast starkly with steady-state communities: increased tolerance of community diversity to fast growth rates of species dominating different community states, enhanced community stability through staggered dominance of different species in different community states, and increased requirement on growth dominance for the inclusion of late-growing species. These features, derived explicitly for simplified models, are proposed here to be principles aiding the understanding of complex dynamical communities. Our model shifts the focus of ecosystem dynamics from bottom-up studies based on idealized inter-species interaction to top-down studies based on accessible macroscopic observables such as growth rates and total biomass density, enabling quantitative examination of community-wide characteristics.
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Affiliation(s)
| | - Terence Hwa
- Department of Physics, University of California, San Diego
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9
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Gralka M. Searching for Principles of Microbial Ecology Across Levels of Biological Organization. Integr Comp Biol 2023; 63:1520-1531. [PMID: 37280177 PMCID: PMC10755194 DOI: 10.1093/icb/icad060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 05/21/2023] [Accepted: 06/01/2023] [Indexed: 06/08/2023] Open
Abstract
Microbial communities play pivotal roles in ecosystems across different scales, from global elemental cycles to household food fermentations. These complex assemblies comprise hundreds or thousands of microbial species whose abundances vary over time and space. Unraveling the principles that guide their dynamics at different levels of biological organization, from individual species, their interactions, to complex microbial communities, is a major challenge. To what extent are these different levels of organization governed by separate principles, and how can we connect these levels to develop predictive models for the dynamics and function of microbial communities? Here, we will discuss recent advances that point towards principles of microbial communities, rooted in various disciplines from physics, biochemistry, and dynamical systems. By considering the marine carbon cycle as a concrete example, we demonstrate how the integration of levels of biological organization can offer deeper insights into the impact of increasing temperatures, such as those associated with climate change, on ecosystem-scale processes. We argue that by focusing on principles that transcend specific microbiomes, we can pave the way for a comprehensive understanding of microbial community dynamics and the development of predictive models for diverse ecosystems.
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Affiliation(s)
- Matti Gralka
- Systems Biology lab, Amsterdam Institute for Life and Environment (A-LIFE), Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, 1081 HV, The Netherlands
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10
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Fu T, Gifford DR, Knight CG, Brockhurst MA. Eco-evolutionary dynamics of experimental Pseudomonas aeruginosa populations under oxidative stress. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001396. [PMID: 37943284 PMCID: PMC10710836 DOI: 10.1099/mic.0.001396] [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: 06/27/2023] [Accepted: 09/26/2023] [Indexed: 11/10/2023]
Abstract
Within-host environments are likely to present a challenging and stressful environment for opportunistic pathogenic bacteria colonizing from the external environment. How populations of pathogenic bacteria respond to such environmental challenges and how this varies between strains is not well understood. Oxidative stress is one of the defences adopted by the human immune system to confront invading bacteria. In this study, we show that strains of the opportunistic pathogenic bacterium Pseudomonas aeruginosa vary in their eco-evolutionary responses to hydrogen peroxide stress. By quantifying their 24 h growth kinetics across hydrogen peroxide gradients we show that a transmissible epidemic strain isolated from a chronic airway infection of a cystic fibrosis patient, LESB58, is much more susceptible to hydrogen peroxide than either of the reference strains, PA14 or PAO1, with PAO1 showing the lowest susceptibility. Using a 12 day serial passaging experiment combined with a mathematical model, we then show that short-term susceptibility controls the longer-term survival of populations exposed to subinhibitory levels of hydrogen peroxide, but that phenotypic evolutionary responses can delay population extinction. Our model further suggests that hydrogen peroxide driven extinctions are more likely with higher rates of population turnover. Together, these findings suggest that hydrogen peroxide is likely to be an effective defence in host niches where there is high population turnover, which may explain the counter-intuitively high susceptibility of a strain isolated from chronic lung infection, where such ecological dynamics may be slower.
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Affiliation(s)
- Taoran Fu
- Division of Evolution, Infection and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, UK
| | - Danna R. Gifford
- Division of Evolution, Infection and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, UK
| | - Christopher G. Knight
- Department of Earth and Environmental Sciences, School of Natural Sciences, Faculty of Science and Engineering, The University of Manchester, Manchester M13 9PT, UK
| | - Michael A. Brockhurst
- Division of Evolution, Infection and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, UK
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11
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D’Souza G, Schwartzman J, Keegstra J, Schreier JE, Daniels M, Cordero OX, Stocker R, Ackermann M. Interspecies interactions determine growth dynamics of biopolymer-degrading populations in microbial communities. Proc Natl Acad Sci U S A 2023; 120:e2305198120. [PMID: 37878716 PMCID: PMC10622921 DOI: 10.1073/pnas.2305198120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 09/12/2023] [Indexed: 10/27/2023] Open
Abstract
Microbial communities perform essential ecosystem functions such as the remineralization of organic carbon that exists as biopolymers. The first step in mineralization is performed by biopolymer degraders, which harbor enzymes that can break down polymers into constituent oligo- or monomeric forms. The released nutrients not only allow degraders to grow, but also promote growth of cells that either consume the degradation products, i.e., exploiters, or consume metabolites released by the degraders or exploiters, i.e., scavengers. It is currently not clear how such remineralizing communities assemble at the microscale-how interactions between the different guilds influence their growth and spatial distribution, and hence the development and dynamics of the community. Here, we address this knowledge gap by studying marine microbial communities that grow on the abundant marine biopolymer alginate. We used batch growth assays and microfluidics coupled to time-lapse microscopy to quantitatively investigate growth and spatial distribution of single cells. We found that the presence of exploiters or scavengers alters the spatial distribution of degrader cells. In general, exploiters and scavengers-which we collectively refer to as cross-feeder cells-slowed down the growth of degrader cells. In addition, coexistence with cross-feeders altered the production of the extracellular enzymes that break down polymers by degrader cells. Our findings reveal that ecological interactions by nondegrading community members have a profound impact on the functions of microbial communities that remineralize carbon biopolymers in nature.
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Affiliation(s)
- Glen D’Souza
- Microbial Systems Ecology Group, Department of Environmental Systems Sciences, Institute of Biogeochemistry and Pollutant Dynamics, ETH-Zurich, Zurich8006, Switzerland
- Department of Environmental Microbiology, Eawag: Swiss Federal Institute of Aquatic Sciences, Duebendorf8600, Switzerland
| | - Julia Schwartzman
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Johannes Keegstra
- Department of Civil, Environmental and Geomatic Engineering, Institute of Environmental Engineering, ETH Zurich, Zurich8093, Switzerland
| | | | - Michael Daniels
- Microbial Systems Ecology Group, Department of Environmental Systems Sciences, Institute of Biogeochemistry and Pollutant Dynamics, ETH-Zurich, Zurich8006, Switzerland
- Department of Environmental Microbiology, Eawag: Swiss Federal Institute of Aquatic Sciences, Duebendorf8600, Switzerland
| | - Otto X. Cordero
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Roman Stocker
- Department of Civil, Environmental and Geomatic Engineering, Institute of Environmental Engineering, ETH Zurich, Zurich8093, Switzerland
| | - Martin Ackermann
- Microbial Systems Ecology Group, Department of Environmental Systems Sciences, Institute of Biogeochemistry and Pollutant Dynamics, ETH-Zurich, Zurich8006, Switzerland
- Department of Environmental Microbiology, Eawag: Swiss Federal Institute of Aquatic Sciences, Duebendorf8600, Switzerland
- Environmental Engineering Institute, School of Architecture, Civil and Environmental Engineering, École polytechnique fédérale de Lausanne, CH-1015Lausanne, Switzerland
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12
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Blumenthal E, Mehta P. Geometry of ecological coexistence and niche differentiation. ARXIV 2023:arXiv:2304.10694v3. [PMID: 37131883 PMCID: PMC10153352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
A fundamental problem in ecology is to understand how competition shapes biodiversity and species coexistence. Historically, one important approach for addressing this question has been to analyze consumer resource models using geometric arguments. This has led to broadly applicable principles such as Tilman's R * and species coexistence cones. Here, we extend these arguments by constructing a novel geometric framework for understanding species coexistence based on convex polytopes in the space of consumer preferences. We show how the geometry of consumer preferences can be used to predict species which may coexist and enumerate ecologically-stable steady states and transitions between them. Collectively, these results provide a framework for understanding the role of species traits within niche theory.
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Affiliation(s)
- Emmy Blumenthal
- Department of Physics, Boston University, Boston, Massachusetts 02215, USA
| | - Pankaj Mehta
- Department of Physics, Boston University, Boston, Massachusetts 02215, USA
- Biological Design Center, Boston University, Boston, Massachusetts 02215, USA
- Faculty of Computing and Data Sciences, Boston University, Boston, Massachusetts 02215, USA
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13
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Gralka M, Pollak S, Cordero OX. Genome content predicts the carbon catabolic preferences of heterotrophic bacteria. Nat Microbiol 2023; 8:1799-1808. [PMID: 37653010 DOI: 10.1038/s41564-023-01458-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 07/24/2023] [Indexed: 09/02/2023]
Abstract
Heterotrophic bacteria-bacteria that utilize organic carbon sources-are taxonomically and functionally diverse across environments. It is challenging to map metabolic interactions and niches within microbial communities due to the large number of metabolites that could serve as potential carbon and energy sources for heterotrophs. Whether their metabolic niches can be understood using general principles, such as a small number of simplified metabolic categories, is unclear. Here we perform high-throughput metabolic profiling of 186 marine heterotrophic bacterial strains cultured in media containing one of 135 carbon substrates to determine growth rates, lag times and yields. We show that, despite high variability at all levels of taxonomy, the catabolic niches of heterotrophic bacteria can be understood in terms of their preference for either glycolytic (sugars) or gluconeogenic (amino and organic acids) carbon sources. This preference is encoded by the total number of genes found in pathways that feed into the two modes of carbon utilization and can be predicted using a simple linear model based on gene counts. This allows for coarse-grained descriptions of microbial communities in terms of prevalent modes of carbon catabolism. The sugar-acid preference is also associated with genomic GC content and thus with the carbon-nitrogen requirements of their encoded proteome. Our work reveals how the evolution of bacterial genomes is structured by fundamental constraints rooted in metabolism.
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Affiliation(s)
- Matti Gralka
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Systems Biology Group, Amsterdam Institute for Life and Environment (A-LIFE) and Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
| | - Shaul Pollak
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Division of Microbial Ecology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Otto X Cordero
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
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14
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Li Z, Sinha V, Kuehn S. Constraints on microbial metabolic complexity. Nat Microbiol 2023; 8:1756-1757. [PMID: 37679599 DOI: 10.1038/s41564-023-01466-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/09/2023]
Affiliation(s)
- Zeqian Li
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Center for the Physics of Evolving Systems, University of Chicago, Chicago, IL, USA
- Department of Ecology and Evolution, University of Chicago, Chicago, IL, USA
| | - Vaibhhav Sinha
- Center for the Physics of Evolving Systems, University of Chicago, Chicago, IL, USA
- Department of Ecology and Evolution, University of Chicago, Chicago, IL, USA
| | - Seppe Kuehn
- Center for the Physics of Evolving Systems, University of Chicago, Chicago, IL, USA.
- Department of Ecology and Evolution, University of Chicago, Chicago, IL, USA.
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15
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Guessous G, Patsalo V, Balakrishnan R, Çağlar T, Williamson JR, Hwa T. Inherited chitinases enable sustained growth and rapid dispersal of bacteria from chitin particles. Nat Microbiol 2023; 8:1695-1705. [PMID: 37580592 DOI: 10.1038/s41564-023-01444-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 07/04/2023] [Indexed: 08/16/2023]
Abstract
Many biogeochemical functions involve bacteria utilizing solid substrates. However, little is known about the coordination of bacterial growth with the kinetics of attachment to and detachment from such substrates. In this quantitative study of Vibrio sp. 1A01 growing on chitin particles, we reveal the heterogeneous nature of the exponentially growing culture comprising two co-existing subpopulations: a minority replicating on chitin particles and a non-replicating majority which was planktonic. This partition resulted from a high rate of cell detachment from particles. Despite high detachment, sustained exponential growth of cells on particles was enabled by the enrichment of extracellular chitinases excreted and left behind by detached cells. The 'inheritance' of these chitinases sustains the colonizing subpopulation despite its reduced density. This simple mechanism helps to circumvent a trade-off between growth and dispersal, allowing particle-associated marine heterotrophs to explore new habitats without compromising their fitness on the habitat they have already colonized.
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Affiliation(s)
- Ghita Guessous
- Department of Physics, University of California at San Diego, La Jolla, CA, USA
| | - Vadim Patsalo
- Department of Integrative Structural and Computational Biology, and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, USA
- DataBricks, San Diego, CA, USA
| | - Rohan Balakrishnan
- Department of Physics, University of California at San Diego, La Jolla, CA, USA
| | - Tolga Çağlar
- Department of Physics, University of California at San Diego, La Jolla, CA, USA
- San Diego Supercomputer Center, La Jolla, CA, USA
| | - James R Williamson
- Department of Integrative Structural and Computational Biology, and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Terence Hwa
- Department of Physics, University of California at San Diego, La Jolla, CA, USA.
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