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Contreras-Moreno FJ, Pérez J, Muñoz-Dorado J, Moraleda-Muñoz A, Marcos-Torres FJ. Myxococcus xanthus predation: an updated overview. Front Microbiol 2024; 15:1339696. [PMID: 38328431 PMCID: PMC10849154 DOI: 10.3389/fmicb.2024.1339696] [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: 11/16/2023] [Accepted: 01/15/2024] [Indexed: 02/09/2024] Open
Abstract
Bacterial predators are widely distributed across a variety of natural environments. Understanding predatory interactions is of great importance since they play a defining role in shaping microbial communities in habitats such as soils. Myxococcus xanthus is a soil-dwelling bacterial predator that can prey on Gram-positive and Gram-negative bacteria and even on eukaryotic microorganisms. This model organism has been studied for many decades for its unusual lifecycle, characterized by the formation of multicellular fruiting bodies filled with myxospores. However, less is known about its predatory behavior despite being an integral part of its lifecycle. Predation in M. xanthus is a multifactorial process that involves several mechanisms working synergistically, including motility systems to efficiently track and hunt prey, and a combination of short-range and contact-dependent mechanisms to achieve prey death and feed on them. In the short-range attack, M. xanthus is best known for the collective production of secondary metabolites and hydrolytic enzymes to kill prey and degrade cellular components. On the other hand, contact-dependent killing is a cell-to-cell process that relies on Tad-like and type III secretion systems. Furthermore, recent research has revealed that metals also play an important role during predation, either by inducing oxidative stress in the prey, or by competing for essential metals. In this paper, we review the current knowledge about M. xanthus predation, focusing on the different mechanisms used to hunt, kill, and feed on its prey, considering the most recent discoveries and the transcriptomic data available.
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Affiliation(s)
| | | | | | - Aurelio Moraleda-Muñoz
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Granada, Spain
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Vasse M, Fiegna F, Kriesel B, Velicer GJ. Killer prey: Ecology reverses bacterial predation. PLoS Biol 2024; 22:e3002454. [PMID: 38261596 PMCID: PMC10805292 DOI: 10.1371/journal.pbio.3002454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 11/30/2023] [Indexed: 01/25/2024] Open
Abstract
Ecological variation influences the character of many biotic interactions, but examples of predator-prey reversal mediated by abiotic context are few. We show that the temperature at which prey grow before interacting with a bacterial predator can determine the very direction of predation, reversing predator and prey identities. While Pseudomonas fluorescens reared at 32°C was extensively killed by the generalist predator Myxococcus xanthus, P. fluorescens reared at 22°C became the predator, slaughtering M. xanthus to extinction and growing on its remains. Beyond M. xanthus, diffusible molecules in P. fluorescens supernatant also killed 2 other phylogenetically distant species among several examined. Our results suggest that the sign of lethal microbial antagonisms may often change across abiotic gradients in natural microbial communities, with important ecological and evolutionary implications. They also suggest that a larger proportion of microbial warfare results in predation-the killing and consumption of organisms-than is generally recognized.
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Affiliation(s)
- Marie Vasse
- MIVEGEC (UMR 5290 CNRS, IRD, UM), CNRS 34394 Montpellier, France
| | - Francesca Fiegna
- Institute for Integrative Biology, ETH Zürich, Zürich, Switzerland
| | - Ben Kriesel
- Institute for Integrative Biology, ETH Zürich, Zürich, Switzerland
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Li L, Huang D, Hu Y, Rudling NM, Canniffe DP, Wang F, Wang Y. Globally distributed Myxococcota with photosynthesis gene clusters illuminate the origin and evolution of a potentially chimeric lifestyle. Nat Commun 2023; 14:6450. [PMID: 37833297 PMCID: PMC10576062 DOI: 10.1038/s41467-023-42193-7] [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: 02/24/2023] [Accepted: 10/02/2023] [Indexed: 10/15/2023] Open
Abstract
Photosynthesis is a fundamental biogeochemical process, thought to be restricted to a few bacterial and eukaryotic phyla. However, understanding the origin and evolution of phototrophic organisms can be impeded and biased by the difficulties of cultivation. Here, we analyzed metagenomic datasets and found potential photosynthetic abilities encoded in the genomes of uncultivated bacteria within the phylum Myxococcota. A putative photosynthesis gene cluster encoding a type-II reaction center appears in at least six Myxococcota families from three classes, suggesting vertical inheritance of these genes from an early common ancestor, with multiple independent losses in other lineages. Analysis of metatranscriptomic datasets indicate that the putative myxococcotal photosynthesis genes are actively expressed in various natural environments. Furthermore, heterologous expression of myxococcotal pigment biosynthesis genes in a purple bacterium supports that the genes can drive photosynthetic processes. Given that predatory abilities are thought to be widespread across Myxococcota, our results suggest the intriguing possibility of a chimeric lifestyle (combining predatory and photosynthetic abilities) in members of this phylum.
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Affiliation(s)
- Liuyang Li
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Danyue Huang
- School of Oceanography, Shanghai Jiao Tong University, Shanghai, 200030, China
| | - Yaoxun Hu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Nicola M Rudling
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Daniel P Canniffe
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Fengping Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
- School of Oceanography, Shanghai Jiao Tong University, Shanghai, 200030, China.
| | - Yinzhao Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
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Yang Y, Tao H, Ma W, Wang N, Chen X, Wang W. Lysis profile and preference of Myxococcus sp. PT13 for typical soil bacteria. Front Microbiol 2023; 14:1211756. [PMID: 37378286 PMCID: PMC10291197 DOI: 10.3389/fmicb.2023.1211756] [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: 04/25/2023] [Accepted: 05/22/2023] [Indexed: 06/29/2023] Open
Abstract
Introduction Myxococcus sp. PT13 is a wild strain with multiple predatory properties that prey on multiple model microorganisms preserved in the laboratory. However, the lysis spectrum of PT13 on typical soil bacteria and its driving effect on soil microecosystems are still unclear. Methods In this study, the lawn predation method was used to determine the predation diameter of 62 typical soil bacteria by myxobacteria PT13 and analyze their lysis spectra. Results and Discussion The results showed that PT13 had a predation diameter greater than 15 mm against typical soil microorganisms such as Aeromonas, Bacillus, Brevibacterium, Fictibacillus, Glutamicibacter, Herbaspirillum, and Leifsonia and had an outstanding lysis effect but a significant preference (p < 0.05). Absolute high-throughput sequencing results showed that PT13 predation drove the microcosmic system composed of 16 bacterial genera, with a significant decrease in the Shannon index by 11.8% (CK = 2.04, D = 1.80) and a significant increase in the Simpson index by 45.0% (CK = 0.20, D = 0.29). The results of principal coordinate analysis (PCoA) showed that myxobacterial addition significantly disturbed the microcosmic microbial community structure (ANOSIM, p < 0.05). LEfSe analysis showed that the relative and absolute abundances (copy numbers) of Bacillus, Pedobacter, Staphylococcus, Streptomyces and Fictibacillus decreased significantly very likely due to myxobacterial predation (p < 0.05). However, the predatory effect of PT13 also increased the relative or absolute abundances of some species, such as Sphingobacterium, Paenarthrobacter, Microbacterium, and Leifsonia. It can be concluded that PT13 has a broad-spectrum lysis spectrum but poor cleavage ability for Streptomyces, and the interaction between complex microorganisms limits the predation effect of PT13 on some prey bacteria. This in turn allows some prey to coexist with myxobacteria. This paper will lay a theoretical foundation for the regulation of soil microecology dominated by myxobacteria.
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Zwarycz AS, Whitworth DE. Myxobacterial Predation: A Standardised Lawn Predation Assay Highlights Strains with Unusually Efficient Predatory Activity. Microorganisms 2023; 11:microorganisms11020398. [PMID: 36838363 PMCID: PMC9967850 DOI: 10.3390/microorganisms11020398] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/30/2023] [Accepted: 02/02/2023] [Indexed: 02/08/2023] Open
Abstract
Myxobacteria prey upon a broad range of microorganisms. Lawn assays are commonly used to quantify myxobacterial predation-myxobacterial suspensions are spotted onto prey lawns, and monitored via spot expansion. The diversity in motility behaviours of myxobacterial strains and differing assay protocols in myxobacteriology laboratories led us to develop a highly-specified assay, which was applied to 28 myxobacterial strains preying on seven phytopathogenic prey species. Generally, prey organisms showed no qualitative differences in their susceptibility/resistance to myxobacterial predation. For most myxobacteria, prey did not stimulate, and in ~50% of cases actively hindered colony expansion. Only ~25% of predator/prey strain combinations exhibited greater colony expansion than in the absence of nutrients. The activity of predatory strains against different prey correlated, implying effective predators may have relatively non-specific predation mechanisms (e.g., broad specificity proteases/lipases), but no correlation was observed between predatory activity and phylogeny. Predation on dead (but intact) or lysed prey cells gave greater colony expansion than on live prey. Occasional strains grew substantially faster on dead compared to lysed cells, or vice-versa. Such differences in accessing nutrients from live, dead and lysed cells indicates there are strain-specific differences in the efficiencies/machineries of prey killing and nutrient acquisition, which has important implications for the ecology of myxobacterial predators and their prey.
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Ibrahimi M, Loqman S, Jemo M, Hafidi M, Lemee L, Ouhdouch Y. The potential of facultative predatory Actinomycetota spp. and prospects in agricultural sustainability. Front Microbiol 2023; 13:1081815. [PMID: 36762097 PMCID: PMC9905845 DOI: 10.3389/fmicb.2022.1081815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 12/28/2022] [Indexed: 01/26/2023] Open
Abstract
Actinomycetota in the phylum of bacteria has been explored extensively as a source of antibiotics and secondary metabolites. In addition to acting as plant growth-promoting agents, they also possess the potential to control various plant pathogens; however, there are limited studies that report the facultative predatory ability of Actinomycetota spp. Furthermore, the mechanisms that underline predation are poorly understood. We assessed the diversity of strategies employed by predatory bacteria to attack and subsequently induce the cell lysing of their prey. We revisited the diversity and abundance of secondary metabolite molecules linked to the different predation strategies by bacteria species. We analyzed the pros and cons of the distinctive predation mechanisms and explored their potential for the development of new biocontrol agents. The facultative predatory behaviors diverge from group attack "wolfpack," cell-to-cell proximity "epibiotic," periplasmic penetration, and endobiotic invasion to degrade host-cellular content. The epibiotic represents the dominant facultative mode of predation, irrespective of the habitat origins. The wolfpack is the second-used approach among the Actinomycetota harboring predatory traits. The secondary molecules as chemical weapons engaged in the respective attacks were reviewed. We finally explored the use of predatory Actinomycetota as a new cost-effective and sustainable biocontrol agent against plant pathogens.
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Affiliation(s)
- Manar Ibrahimi
- Laboratory of Molecular Chemistry, Materials and Catalysis, Faculty of Sciences and Technics, Sultan Moulay Slimane University, Beni-Mellal, Morocco,Higher School of Technology Fkih Ben Salah, Sultan Moulay Slimane University, Fkih Ben Salah, Morocco
| | - Souad Loqman
- Laboratory of Microbiology and Virology, Faculty of Medicine and Pharmacy, Cadi Ayyad University, Marrakesh, Morocco
| | - Martin Jemo
- AgroBiosciences Program, Mohammed VI Polytechnic University (UM6P), Ben Guerir, Morocco
| | - Mohamed Hafidi
- AgroBiosciences Program, Mohammed VI Polytechnic University (UM6P), Ben Guerir, Morocco,Labelled Research Unit N°4 CNRST, Laboratory of Microbial Biotechnologies, Agrosciences and Environment (BioMAgE), Faculty of Sciences Semlalia, Cadi Ayyad University, Marrakesh, Morocco
| | - Laurent Lemee
- Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP–CNRS UMR 7285), Université de Poitiers, Poitiers, France
| | - Yedir Ouhdouch
- AgroBiosciences Program, Mohammed VI Polytechnic University (UM6P), Ben Guerir, Morocco,Labelled Research Unit N°4 CNRST, Laboratory of Microbial Biotechnologies, Agrosciences and Environment (BioMAgE), Faculty of Sciences Semlalia, Cadi Ayyad University, Marrakesh, Morocco,*Correspondence: Yedir Ouhdouch,
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The soil microbial food web revisited: Predatory myxobacteria as keystone taxa? THE ISME JOURNAL 2021; 15:2665-2675. [PMID: 33746204 PMCID: PMC8397742 DOI: 10.1038/s41396-021-00958-2] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 02/24/2021] [Accepted: 03/04/2021] [Indexed: 02/07/2023]
Abstract
Trophic interactions are crucial for carbon cycling in food webs. Traditionally, eukaryotic micropredators are considered the major micropredators of bacteria in soils, although bacteria like myxobacteria and Bdellovibrio are also known bacterivores. Until recently, it was impossible to assess the abundance of prokaryotes and eukaryotes in soil food webs simultaneously. Using metatranscriptomic three-domain community profiling we identified pro- and eukaryotic micropredators in 11 European mineral and organic soils from different climes. Myxobacteria comprised 1.5-9.7% of all obtained SSU rRNA transcripts and more than 60% of all identified potential bacterivores in most soils. The name-giving and well-characterized predatory bacteria affiliated with the Myxococcaceae were barely present, while Haliangiaceae and Polyangiaceae dominated. In predation assays, representatives of the latter showed prey spectra as broad as the Myxococcaceae. 18S rRNA transcripts from eukaryotic micropredators, like amoeba and nematodes, were generally less abundant than myxobacterial 16S rRNA transcripts, especially in mineral soils. Although SSU rRNA does not directly reflect organismic abundance, our findings indicate that myxobacteria could be keystone taxa in the soil microbial food web, with potential impact on prokaryotic community composition. Further, they suggest an overlooked, yet ecologically relevant food web module, independent of eukaryotic micropredators and subject to separate environmental and evolutionary pressures.
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Behavioral Interactions between Bacterivorous Nematodes and Predatory Bacteria in a Synthetic Community. Microorganisms 2021; 9:microorganisms9071362. [PMID: 34201688 PMCID: PMC8307948 DOI: 10.3390/microorganisms9071362] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 06/07/2021] [Accepted: 06/12/2021] [Indexed: 11/17/2022] Open
Abstract
Theory and empirical studies in metazoans predict that apex predators should shape the behavior and ecology of mesopredators and prey at lower trophic levels. Despite the ecological importance of microbial communities, few studies of predatory microbes examine such behavioral res-ponses and the multiplicity of trophic interactions. Here, we sought to assemble a three-level microbial food chain and to test for behavioral interactions between the predatory nematode Caenorhabditis elegans and the predatory social bacterium Myxococcus xanthus when cultured together with two basal prey bacteria that both predators can eat—Escherichia coli and Flavobacterium johnsoniae. We found that >90% of C. elegans worms failed to interact with M. xanthus even when it was the only potential prey species available, whereas most worms were attracted to pure patches of E. coli and F. johnsoniae. In addition, M. xanthus altered nematode predatory behavior on basal prey, repelling C. elegans from two-species patches that would be attractive without M. xanthus, an effect similar to that of C. elegans pathogens. The nematode also influenced the behavior of the bacterial predator: M. xanthus increased its predatory swarming rate in response to C. elegans in a manner dependent both on basal-prey identity and on worm density. Our results suggest that M. xanthus is an unattractive prey for some soil nematodes and is actively avoided when other prey are available. Most broadly, we found that nematode and bacterial predators mutually influence one another’s predatory behavior, with likely consequences for coevolution within complex microbial food webs.
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Baker CA, De J, Schneider KR. Influence of soil microbes on Escherichia coli O157:H7 survival in soil rinse and artificial soil. J Appl Microbiol 2021; 131:1531-1538. [PMID: 33583119 DOI: 10.1111/jam.15039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 01/10/2021] [Accepted: 02/10/2021] [Indexed: 11/27/2022]
Abstract
AIMS This research investigated the influence of soil microbiota on Escherichia coli O157:H7 survival in soil rinse and artificial soil. Additionally, the influence of selected soil bacteria on E. coli O157:H7 in soil environments was determined. METHODS AND RESULTS Escherichia coli O157:H7 counts (log CFU per ml or g-1 ) were determined by spread plating: (i) artificial soil amended with soil rinse (filter-sterilized and unfiltered) at 30°C; (ii) unfiltered soil rinse (50 ml) treated with cycloheximide (200 μg ml-1 ), vancomycin (40 μg ml-1 ), heat (80°C, 15 min) and no treatment (control) for 7 days at 30°C and (iii) filtered soil rinse with selected soil bacterial isolates over 7 days. There was a significant difference (P = 0·027) in E. coli O157:H7 counts after 35 days between artificial soils amended with filtered (4·45 ± 0·29) and non-filtered (1·83 ± 0·33) soil rinse. There were significant differences (P < 0·05) in E. coli O157:H7 counts after 3 days of incubation between soil rinse treatments (heat (7·04 ± 0·03), cycloheximide (6·94 ± 0·05), vancomycin (4·26 ± 0·98) and control (5·00 ± 0·93)). Lastly, a significant difference (P < 0·05) in E. coli O157:H7 counts was observed after 3 days of incubation at 30°C in filtered soil rinse when incubated with Paenibacillus alvei versus other soil bacterial isolates evaluated. CONCLUSIONS Soil microbiota isolated from Florida sandy soil influenced E. coli O157:H7 survival. Specifically, P. alvei reduced E. coli O157:H7 by over 3 log CFU per ml after 3 days of incubation at 30°C in filtered soil rinse. SIGNIFICANCE AND IMPACT OF THE STUDY This research identified soil bacterial isolates that may reduce E. coli O157:H7 in the soil environment and be used in future biocontrol applications.
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Affiliation(s)
- C A Baker
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, FL, USA
| | - J De
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, FL, USA
| | - K R Schneider
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, FL, USA
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Myxococcus xanthus predation of Gram-positive or Gram-negative bacteria is mediated by different bacteriolytic mechanisms. Appl Environ Microbiol 2021; 87:AEM.02382-20. [PMID: 33310723 PMCID: PMC8090889 DOI: 10.1128/aem.02382-20] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Myxococcus xanthus kills other species to use their biomass as energy source. Its predation mechanisms allow feeding on a broad spectrum of bacteria, but the identity of predation effectors and their mode of action remains largely unknown. We initially focused on the role of hydrolytic enzymes for prey killing and compared the activity of secreted M. xanthus proteins against four prey strains. 72 secreted proteins were identified by mass spectrometry, and among them a family 19 glycoside hydrolase that displayed bacteriolytic activity in vivo and in vitro This enzyme, which we name LlpM (lectin/lysozyme-like protein of M. xanthus), was not essential for predation, indicating that additional secreted components are required to disintegrate prey. Furthermore, secreted proteins lysed only Gram-positive, but not Gram-negative species. We thus compared the killing of different preys by cell-associated mechanisms: Individual M. xanthus cells killed all four test strains in a cell-contact dependent manner, but were only able to disintegrate Gram-negative, not Gram-positive cell envelopes. Thus, our data indicate that M. xanthus uses different, multifactorial mechanisms for killing and degrading different preys. Besides secreted enzymes, cell-associated mechanisms that have not been characterized so far, appear to play a major role for prey killing.IMPORTANCEPredation is an important survival strategy of the widespread myxobacteria, but it remains poorly understood on the mechanistic level. Without a basic understanding of how prey cell killing and consumption is achieved, it also remains difficult to investigate the role of predation for the complex myxobacterial lifestyle, reciprocal predator-prey relationships or the impact of predation on complex bacterial soil communities.We study predation in the established model organism Myxococcus xanthus, aiming to dissect the molecular mechanisms of prey cell lysis. In this study, we addressed the role of secreted bacteriolytic proteins, as well as potential mechanistic differences in the predation of Gram-positive and Gram-negative bacteria. Our observation shows that secreted enzymes are sufficient for killing and degrading Gram-positive species, but that cell-associated mechanisms may play a major role for killing Gram-negative and Gram-positive prey on fast timescales.
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Identification of a solo acylhomoserine lactone synthase from the myxobacterium Archangium gephyra. Sci Rep 2021; 11:3018. [PMID: 33542315 PMCID: PMC7862692 DOI: 10.1038/s41598-021-82480-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 01/20/2021] [Indexed: 12/31/2022] Open
Abstract
Considered a key taxon in soil and marine microbial communities, myxobacteria exist as coordinated swarms that utilize a combination of lytic enzymes and specialized metabolites to facilitate predation of microbes. This capacity to produce specialized metabolites and the associated abundance of biosynthetic pathways contained within their genomes have motivated continued drug discovery efforts from myxobacteria. Of all myxobacterial biosynthetic gene clusters deposited in the antiSMASH database, only one putative acylhomoserine lactone (AHL) synthase, agpI, was observed, in genome data from Archangium gephyra. Without an AHL receptor also apparent in the genome of A. gephyra, we sought to determine if AgpI was an uncommon example of an orphaned AHL synthase. Herein we report the bioinformatic assessment of AgpI and discovery of a second AHL synthase from Vitiosangium sp. During axenic cultivation conditions, no detectible AHL metabolites were observed in A. gephyra extracts. However, heterologous expression of each synthase in Escherichia coli provided detectible quantities of 3 AHL signals including 2 known AHLs, C8-AHL and C9-AHL. These results suggest that A. gephyra AHL production is dormant during axenic cultivation. The functional, orphaned AHL synthase, AgpI, is unique to A. gephyra, and its utility to the predatory myxobacterium remains unknown.
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Pérez J, Contreras-Moreno FJ, Marcos-Torres FJ, Moraleda-Muñoz A, Muñoz-Dorado J. The antibiotic crisis: How bacterial predators can help. Comput Struct Biotechnol J 2020; 18:2547-2555. [PMID: 33033577 PMCID: PMC7522538 DOI: 10.1016/j.csbj.2020.09.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 09/07/2020] [Accepted: 09/08/2020] [Indexed: 12/30/2022] Open
Abstract
Discovery of antimicrobials in the past century represented one of the most important advances in public health. Unfortunately, the massive use of these compounds in medicine and other human activities has promoted the selection of pathogens that are resistant to one or several antibiotics. The current antibiotic crisis is creating an urgent need for research into new biological weapons with the ability to kill these superbugs. Although a proper solution requires this problem to be addressed in a variety of ways, the use of bacterial predators is emerging as an excellent strategy, especially when used as whole cell therapeutic agents, as a source of new antimicrobial agents by awakening silent metabolic pathways in axenic cultures, or as biocontrol agents. Moreover, studies on their prey are uncovering mechanisms of resistance that can be shared by pathogens, representing new targets for novel antimicrobial agents. In this review we discuss potential of the studies on predator-prey interaction to provide alternative solutions to the problem of antibiotic resistance.
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Key Words
- AR, antibiotic resistance
- ARB, antibiotic-resistant bacteria
- ARG, antibiotic-resistant gene
- Antibiotic crisis
- BALOs
- BALOs, Bdellovibrio and like organisms
- BGC, biosynthetic gene cluster
- Bacterial predators
- HGT, horizontal gene transfer
- MDRB, multi-drug resistant bacteria
- Myxobacteria
- NRPS, nonribosomal peptide synthetase
- OMV, outer membrane vesicle
- OSMAC, one strain many compounds
- PKS, polyketide synthase
- SM, secondary metabolite
- WHO, World Health Organization
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Affiliation(s)
- Juana Pérez
- Departamento de Microbiología, Facultad de Ciencias, Avda. Fuentenueva s/n, Universidad de Granada, 18071 Granada, Spain
| | | | | | - Aurelio Moraleda-Muñoz
- Departamento de Microbiología, Facultad de Ciencias, Avda. Fuentenueva s/n, Universidad de Granada, 18071 Granada, Spain
| | - José Muñoz-Dorado
- Departamento de Microbiología, Facultad de Ciencias, Avda. Fuentenueva s/n, Universidad de Granada, 18071 Granada, Spain
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Wang S, Mu D, Du ZJ. Persicimonas caeni gen. nov., sp. nov., the Representative of a Novel Wide-Ranging Predatory Taxon in Bradymonadales. Front Microbiol 2020; 11:698. [PMID: 32390976 PMCID: PMC7188933 DOI: 10.3389/fmicb.2020.00698] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 03/25/2020] [Indexed: 11/29/2022] Open
Abstract
A novel bacterial strain, designated YN101T, was isolated from a marine solar saltern in the coast of Weihai, Shandong Province, China. Strain YN101T was Gram-stain negative, facultatively anaerobic, oxidase and catalase negative bacterium with the ability to prey on other microbes. A cross-streaking culture method was utilized to analyze the predatory activity of strain YN101T. The results showed strain YN101T could prey on various bacteria, either Gram-stain negative or Gram-stain positive. According to the predatory assays, different species in the same genus may behave differently when attacked by strain YN101T. The predatory behavior of strain YN101T to four typical species was analyzed, and furthermore, predation to Algoriphagus marinus am2T were quantitatively studied by fluorogenic quantitative PCR, and the gene copies decreased over two magnitudes. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain YN101T shared the greatest sequence similarity of 93.9% to Bradymonas sediminis FA350T. The complete genome sequence of strain YN101T was 8,047,306 bp in size and the genomic DNA G + C content was 63.8 mol%. The digital DNA-DNA hybridization (dDDH) values and average nucleotide identity (ANI) values between strain YN101T and B. sediminis FA350T were 13.9 and 74.0%. The genetic features showed that the biosynthesis of many important compounds was deficient in genome of strain YN101T, which may lead to its predation. Moreover, its genome encoded many genes affiliated with type IV pili, secretion system, membrane proteins and transduction proteins. Similar with myxobacteria and Bdellovibrio and like organisms (BALOs), these genes should play important roles in motility, adhesion or virulence to attack prey cells during predation. The predominant polar lipid profile of strain YN101T consisted of phosphatidylethanolamine (PE), phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), and one unidentified aminophospholipid (APL). The major cellular fatty acid of strain YN101T was iso-C17:0, and the sole respiratory quinone was MK-7. Based on the chemotaxonomic, physiological and biochemical characteristics, strain YN101T represents a novel species of a novel genus in the family Bradymonadaceae, for which the name Persicimonas caeni gen. nov., sp. nov. is proposed. The type strain is YN101T (=KCTC 72083T = MCCC 1H00374T).
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Affiliation(s)
- Shuo Wang
- Marine College, Shandong University, Weihai, China
| | - Dashuai Mu
- Marine College, Shandong University, Weihai, China.,State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Zong-Jun Du
- Marine College, Shandong University, Weihai, China.,State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
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14
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Thiery S, Kaimer C. The Predation Strategy of Myxococcus xanthus. Front Microbiol 2020; 11:2. [PMID: 32010119 PMCID: PMC6971385 DOI: 10.3389/fmicb.2020.00002] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 01/03/2020] [Indexed: 11/20/2022] Open
Abstract
Myxobacteria are ubiquitous in soil environments. They display a complex life cycle: vegetatively growing cells coordinate their motility to form multicellular swarms, which upon starvation aggregate into large fruiting bodies where cells differentiate into spores. In addition to growing as saprophytes, Myxobacteria are predators that actively kill bacteria of other species to consume their biomass. In this review, we summarize research on the predation behavior of the model myxobacterium Myxococcus xanthus, which can access nutrients from a broad spectrum of microorganisms. M. xanthus displays an epibiotic predation strategy, i.e., it induces prey lysis from the outside and feeds on the released biomass. This predatory behavior encompasses various processes: Gliding motility and induced cell reversals allow M. xanthus to encounter prey and to remain within the area to sweep up its biomass, which causes the characteristic “rippling” of preying populations. Antibiotics and secreted bacteriolytic enzymes appear to be important predation factors, which are possibly targeted to prey cells with the aid of outer membrane vesicles. However, certain bacteria protect themselves from M. xanthus predation by forming mechanical barriers, such as biofilms and mucoid colonies, or by secreting antibiotics. Further understanding the molecular mechanisms that mediate myxobacterial predation will offer fascinating insight into the reciprocal relationships of bacteria in complex communities, and might spur application-oriented research on the development of novel antibacterial strategies.
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Affiliation(s)
- Susanne Thiery
- Department of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Christine Kaimer
- Department of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
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15
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Nair RR, Vasse M, Wielgoss S, Sun L, Yu YTN, Velicer GJ. Bacterial predator-prey coevolution accelerates genome evolution and selects on virulence-associated prey defences. Nat Commun 2019; 10:4301. [PMID: 31541093 PMCID: PMC6754418 DOI: 10.1038/s41467-019-12140-6] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 08/22/2019] [Indexed: 01/08/2023] Open
Abstract
Generalist bacterial predators are likely to strongly shape many important ecological and evolutionary features of microbial communities, for example by altering the character and pace of molecular evolution, but investigations of such effects are scarce. Here we report how predator-prey interactions alter the evolution of fitness, genomes and phenotypic diversity in coevolving bacterial communities composed of Myxococcus xanthus as predator and Escherichia coli as prey, relative to single-species controls. We show evidence of reciprocal adaptation and demonstrate accelerated genomic evolution specific to coevolving communities, including the rapid appearance of mutator genotypes. Strong parallel evolution unique to the predator-prey communities occurs in both parties, with predators driving adaptation at two prey traits associated with virulence in bacterial pathogens-mucoidy and the outer-membrane protease OmpT. Our results suggest that generalist predatory bacteria are important determinants of how complex microbial communities and their interaction networks evolve in natural habitats.
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Affiliation(s)
- Ramith R Nair
- Institute for Integrative Biology, ETH Zürich, Zürich, 8092, Switzerland.
| | - Marie Vasse
- Institute for Integrative Biology, ETH Zürich, Zürich, 8092, Switzerland.
| | - Sébastien Wielgoss
- Institute for Integrative Biology, ETH Zürich, Zürich, 8092, Switzerland
| | - Lei Sun
- Institute for Integrative Biology, ETH Zürich, Zürich, 8092, Switzerland
- Department of Systems Biology, Harvard Medical School, 02115, Boston, MA, USA
| | - Yuen-Tsu N Yu
- Institute for Integrative Biology, ETH Zürich, Zürich, 8092, Switzerland
| | - Gregory J Velicer
- Institute for Integrative Biology, ETH Zürich, Zürich, 8092, Switzerland
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16
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Marshall RC, Whitworth DE. Is "Wolf-Pack" Predation by Antimicrobial Bacteria Cooperative? Cell Behaviour and Predatory Mechanisms Indicate Profound Selfishness, Even when Working Alongside Kin. Bioessays 2019; 41:e1800247. [PMID: 30919490 DOI: 10.1002/bies.201800247] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 02/10/2019] [Indexed: 01/27/2023]
Abstract
For decades, myxobacteria have been spotlighted as exemplars of social "wolf-pack" predation, communally secreting antimicrobial substances into the shared public milieu. This behavior has been described as cooperative, becoming more efficient if performed by more cells. However, laboratory evidence for cooperativity is limited and of little relevance to predation in a natural setting. In contrast, there is accumulating evidence for predatory mechanisms promoting "selfish" behavior during predation, which together with conflicting definitions of cooperativity, casts doubt on whether microbial "wolf-pack" predation really is cooperative. Here, it is hypothesized that public-goods-mediated predation is not cooperative, and it is argued that a holistic model of microbial predation is needed, accounting for predator and prey relatedness, social phenotypes, spatial organization, activity/specificity/transport of secreted toxins, and prey resistance mechanisms. Filling such gaps in our knowledge is vital if the evolutionary benefits of potentially costly microbial behaviors mediated by public goods are to be properly understood.
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Affiliation(s)
- Rupert C Marshall
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, Ceredigion SY23 3DA, UK
| | - David E Whitworth
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, Ceredigion SY23 3DA, UK
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17
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Livingstone PG, Millard AD, Swain MT, Whitworth DE. Transcriptional changes when Myxococcus xanthus preys on Escherichia coli suggest myxobacterial predators are constitutively toxic but regulate their feeding. Microb Genom 2018; 4:e000152. [PMID: 29345219 PMCID: PMC5857379 DOI: 10.1099/mgen.0.000152] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 12/21/2017] [Indexed: 01/01/2023] Open
Abstract
Predation is a fundamental ecological process, but within most microbial ecosystems the molecular mechanisms of predation remain poorly understood. We investigated transcriptome changes associated with the predation of Escherichia coli by the myxobacterium Myxococcus xanthus using mRNA sequencing. Exposure to pre-killed prey significantly altered expression of 1319 predator genes. However, the transcriptional response to living prey was minimal, with only 12 genes being significantly up-regulated. The genes most induced by prey presence (kdpA and kdpB, members of the kdp regulon) were confirmed by reverse transcriptase quantitative PCR to be regulated by osmotic shock in M. xanthus, suggesting indirect sensing of prey. However, the prey showed extensive transcriptome changes when co-cultured with predator, with 40 % of its genes (1534) showing significant changes in expression. Bacteriolytic M. xanthus culture supernatant and secreted outer membrane vesicles (OMVs) also induced changes in expression of large numbers of prey genes (598 and 461, respectively). Five metabolic pathways were significantly enriched in prey genes up-regulated on exposure to OMVs, supernatant and/or predatory cells, including those for ribosome and lipopolysaccharide production, suggesting that the prey cell wall and protein production are primary targets of the predator's attack. Our data suggest a model of the myxobacterial predatome (genes and proteins associated with predation) in which the predator constitutively produces secretions which disable its prey whilst simultaneously generating a signal that prey is present. That signal then triggers a regulated feeding response in the predator.
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Affiliation(s)
- Paul G. Livingstone
- IBERS, Aberystwyth University, Cledwyn Building, Penglais Campus, Aberystwyth, Ceredigion, SY23 3DD, UK
| | | | - Martin T. Swain
- IBERS, Aberystwyth University, Cledwyn Building, Penglais Campus, Aberystwyth, Ceredigion, SY23 3DD, UK
| | - David E. Whitworth
- IBERS, Aberystwyth University, Cledwyn Building, Penglais Campus, Aberystwyth, Ceredigion, SY23 3DD, UK
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18
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Zee PC, Liu J, Velicer GJ. Pervasive, yet idiosyncratic, epistatic pleiotropy during adaptation in a behaviourally complex microbe. J Evol Biol 2016; 30:257-269. [PMID: 27862537 DOI: 10.1111/jeb.12999] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 08/29/2016] [Accepted: 10/03/2016] [Indexed: 01/14/2023]
Abstract
Understanding how multiple mutations interact to jointly impact multiple ecologically important traits is critical for creating a robust picture of organismal fitness and the process of adaptation. However, this is complicated by both environmental heterogeneity and the complexity of genotype-to-phenotype relationships generated by pleiotropy and epistasis. Moreover, little is known about how pleiotropic and epistatic relationships themselves change over evolutionary time. The soil bacterium Myxococcus xanthus employs several distinct social traits across a range of environments. Here, we use an experimental lineage of M. xanthus that evolved a novel form of social motility to address how interactions between epistasis and pleiotropy evolve. Specifically, we test how mutations accumulated during selection on soft agar pleiotropically affect several other social traits (hard agar motility, predation and spore production). Relationships between changes in swarming rate in the selective environment and the four other traits varied greatly over time in both direction and magnitude, both across timescales of the entire evolutionary lineage and individual evolutionary time steps. We also tested how a previously defined epistatic interaction is pleiotropically expressed across these traits. We found that phenotypic effects of this epistatic interaction were highly correlated between soft and hard agar motility, but were uncorrelated between soft agar motility and predation, and inversely correlated between soft agar motility and spore production. Our results show that 'epistatic pleiotropy' varied greatly in magnitude, and often even in sign, across traits and over time, highlighting the necessity of simultaneously considering the interacting complexities of pleiotropy and epistasis when studying the process of adaptation.
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Affiliation(s)
- P C Zee
- Department of Biology, Indiana University, Bloomington, IN, USA
| | - J Liu
- Department of Biology, Indiana University, Bloomington, IN, USA
| | - G J Velicer
- Department of Biology, Indiana University, Bloomington, IN, USA
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19
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Unraveling the predator-prey relationship of Cupriavidus necator and Bacillus subtilis. Microbiol Res 2016; 192:231-238. [PMID: 27664741 DOI: 10.1016/j.micres.2016.07.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 07/25/2016] [Accepted: 07/28/2016] [Indexed: 01/31/2023]
Abstract
Cupriavidus necator is a non-obligate bacterial predator of Gram-negative and Gram-positive bacteria. In this study, we set out to determine the conditions, which are necessary to observe predatory behavior of C. necator. Using Bacillus subtilis as a prey organism, we confirmed that the predatory performance of C. necator is correlated with the available copper level, and that the killing is mediated, at least in part, by secreted extracellular factors. The predatory activity depends on the nutrition status of C. necator, but does not require a quorum of predator cells. This suggests that C. necator is no group predator. Further analyses revealed that sporulation enables B. subtilis to avoid predation by C. necator. In contrast to the interaction with predatory myxobacteria, however, an intact spore coat is not required for resistance. Instead resistance is possibly mediated by quiescence.
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20
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Muñoz-Dorado J, Marcos-Torres FJ, García-Bravo E, Moraleda-Muñoz A, Pérez J. Myxobacteria: Moving, Killing, Feeding, and Surviving Together. Front Microbiol 2016; 7:781. [PMID: 27303375 PMCID: PMC4880591 DOI: 10.3389/fmicb.2016.00781] [Citation(s) in RCA: 199] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 05/09/2016] [Indexed: 11/13/2022] Open
Abstract
Myxococcus xanthus, like other myxobacteria, is a social bacterium that moves and feeds cooperatively in predatory groups. On surfaces, rod-shaped vegetative cells move in search of the prey in a coordinated manner, forming dynamic multicellular groups referred to as swarms. Within the swarms, cells interact with one another and use two separate locomotion systems. Adventurous motility, which drives the movement of individual cells, is associated with the secretion of slime that forms trails at the leading edge of the swarms. It has been proposed that cellular traffic along these trails contributes to M. xanthus social behavior via stigmergic regulation. However, most of the cells travel in groups by using social motility, which is cell contact-dependent and requires a large number of individuals. Exopolysaccharides and the retraction of type IV pili at alternate poles of the cells are the engines associated with social motility. When the swarms encounter prey, the population of M. xanthus lyses and takes up nutrients from nearby cells. This cooperative and highly density-dependent feeding behavior has the advantage that the pool of hydrolytic enzymes and other secondary metabolites secreted by the entire group is shared by the community to optimize the use of the degradation products. This multicellular behavior is especially observed in the absence of nutrients. In this condition, M. xanthus swarms have the ability to organize the gliding movements of 1000s of rods, synchronizing rippling waves of oscillating cells, to form macroscopic fruiting bodies, with three subpopulations of cells showing division of labor. A small fraction of cells either develop into resistant myxospores or remain as peripheral rods, while the majority of cells die, probably to provide nutrients to allow aggregation and spore differentiation. Sporulation within multicellular fruiting bodies has the benefit of enabling survival in hostile environments, and increases germination and growth rates when cells encounter favorable conditions. Herein, we review how these social bacteria cooperate and review the main cell–cell signaling systems used for communication to maintain multicellularity.
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Affiliation(s)
- José Muñoz-Dorado
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada Granada, Spain
| | | | - Elena García-Bravo
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada Granada, Spain
| | - Aurelio Moraleda-Muñoz
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada Granada, Spain
| | - Juana Pérez
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada Granada, Spain
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21
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Korp J, Vela Gurovic MS, Nett M. Antibiotics from predatory bacteria. Beilstein J Org Chem 2016; 12:594-607. [PMID: 27340451 PMCID: PMC4902038 DOI: 10.3762/bjoc.12.58] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 03/11/2016] [Indexed: 11/23/2022] Open
Abstract
Bacteria, which prey on other microorganisms, are commonly found in the environment. While some of these organisms act as solitary hunters, others band together in large consortia before they attack their prey. Anecdotal reports suggest that bacteria practicing such a wolfpack strategy utilize antibiotics as predatory weapons. Consistent with this hypothesis, genome sequencing revealed that these micropredators possess impressive capacities for natural product biosynthesis. Here, we will present the results from recent chemical investigations of this bacterial group, compare the biosynthetic potential with that of non-predatory bacteria and discuss the link between predation and secondary metabolism.
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Affiliation(s)
- Juliane Korp
- Leibniz Institute for Natural Product Research and Infection Biology – Hans-Knöll-Institute, Beutenbergstr. 11, 07745 Jena, Germany
| | - María S Vela Gurovic
- Centro de Recursos Naturales Renovables de la Zona Semiárida (CERZOS) -CONICET- Carrindanga Km 11, Bahía Blanca 8000, Argentina
| | - Markus Nett
- Leibniz Institute for Natural Product Research and Infection Biology – Hans-Knöll-Institute, Beutenbergstr. 11, 07745 Jena, Germany
- Department of Biochemical and Chemical Engineering, Technical Biology, Technical University Dortmund, Emil-Figge-Strasse 66, 44227 Dortmund, Germany
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22
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Pérez J, Moraleda-Muñoz A, Marcos-Torres FJ, Muñoz-Dorado J. Bacterial predation: 75 years and counting! Environ Microbiol 2016; 18:766-79. [PMID: 26663201 DOI: 10.1111/1462-2920.13171] [Citation(s) in RCA: 132] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 11/23/2015] [Accepted: 12/01/2015] [Indexed: 11/30/2022]
Abstract
The first documented study on bacterial predation was carried out using myxobacteria three quarters of a century ago. Since then, many predatory strains, diverse hunting strategies, environmental consequences and potential applications have been reported by groups all over the world. Now we know that predatory bacteria are distributed in a wide variety of environments and that interactions between predatory and non-predatory populations seem to be the most important factor in bacterial selection and mortality in some ecosystems. Bacterial predation has now been proposed as an evolutionary driving force. The structure and diversity of the predatory bacterial community is beginning to be recognized as an important factor in biodiversity due to its potential role in controlling and modelling bacterial populations in the environment. In this paper, we review the current understanding of bacterial predation, going over the strategies used by the main predatory bacteria to kill their prey. We have also reviewed and integrated the accumulated advances of the last 75 years with the interesting new insights that are provided by the analyses of genomes, predatomes, predatosomes and other comparative genomics studies, focusing on potential applications that derive from all of these areas of study.
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Affiliation(s)
- Juana Pérez
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Avda. Fuentenueva s/n, E-18071, Granada, Spain
| | - Aurelio Moraleda-Muñoz
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Avda. Fuentenueva s/n, E-18071, Granada, Spain
| | - Francisco Javier Marcos-Torres
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Avda. Fuentenueva s/n, E-18071, Granada, Spain
| | - José Muñoz-Dorado
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Avda. Fuentenueva s/n, E-18071, Granada, Spain
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23
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Keane R, Berleman J. The predatory life cycle of Myxococcus xanthus. Microbiology (Reading) 2016; 162:1-11. [DOI: 10.1099/mic.0.000208] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Ryan Keane
- Department of Biology, Saint Mary's College, Moraga, CA 94556, USA
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - James Berleman
- Department of Biology, Saint Mary's College, Moraga, CA 94556, USA
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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Seccareccia I, Kost C, Nett M. Quantitative Analysis of Lysobacter Predation. Appl Environ Microbiol 2015; 81:7098-105. [PMID: 26231654 PMCID: PMC4579460 DOI: 10.1128/aem.01781-15] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 07/28/2015] [Indexed: 02/01/2023] Open
Abstract
Bacteria of the genus Lysobacter are considered to be facultative predators that use a feeding strategy similar to that of myxobacteria. Experimental data supporting this assumption, however, are scarce. Therefore, the predatory activities of three Lysobacter species were tested in the prey spot plate assay and in the lawn predation assay, which are commonly used to analyze myxobacterial predation. Surprisingly, only one of the tested Lysobacter species showed predatory behavior in the two assays. This result suggested that not all Lysobacter strains are predatory or, alternatively, that the assays were not appropriate for determining the predatory potential of this bacterial group. To differentiate between the two scenarios, predation was tested in a CFU-based bioassay. For this purpose, defined numbers of Lysobacter cells were mixed together with potential prey bacteria featuring phenotypic markers, such as distinctive pigmentation or antibiotic resistance. After 24 h, cocultivated cells were streaked out on agar plates and sizes of bacterial populations were individually determined by counting the respective colonies. Using the CFU-based predation assay, we observed that Lysobacter spp. strongly antagonized other bacteria under nutrient-deficient conditions. Simultaneously, the Lysobacter population was increasing, which together with the killing of the cocultured bacteria indicated predation. Variation of the predator/prey ratio revealed that all three Lysobacter species tested needed to outnumber their prey for efficient predation, suggesting that they exclusively practiced group predation. In summary, the CFU-based predation assay not only enabled the quantification of prey killing and consumption by Lysobacter spp. but also provided insights into their mode of predation.
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Affiliation(s)
- Ivana Seccareccia
- Secondary Metabolism of Predatory Bacteria Junior Research Group, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knöll-Institute, Jena, Germany
| | - Christian Kost
- Experimental Ecology and Evolution Research Group, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Markus Nett
- Secondary Metabolism of Predatory Bacteria Junior Research Group, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knöll-Institute, Jena, Germany
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25
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Mendes-Soares H, Chen ICK, Fitzpatrick K, Velicer GJ. Chimaeric load among sympatric social bacteria increases with genotype richness. Proc Biol Sci 2015; 281:rspb.2014.0285. [PMID: 24870038 DOI: 10.1098/rspb.2014.0285] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The total productivity of social groups can be determined by interactions among their constituents. Chimaeric load--the reduction of group productivity caused by antagonistic within-group heterogeneity--may be common in heterogeneous microbial groups due to dysfunctional behavioural interactions between distinct individuals. However, some instances of chimaerism in social microbes can increase group productivity, thus making a general relationship between chimaerism and group-level performance non-obvious. Using genetically similar strains of the soil bacterium Myxococcus xanthus that were isolated from a single centimetre-scale patch of soil, we tested for a relationship between degree of chimaerism (genotype richness) and total group performance at social behaviours displayed by this species. Within-group genotype richness was found to correlate negatively with total group performance at most traits examined, including swarming in both predatory and prey-free environments and spore production during development. These results suggest that interactions between such neighbouring strains in the wild will tend to be mutually antagonistic. Negative correlations between group performance and average genetic distance among group constituents at three known social genes were not found, suggesting that divergence at other loci that govern social interaction phenotypes is responsible for the observed chimaeric load. The potential for chimaeric load to result from co-aggregation among even closely related neighbours may promote the maintenance and strengthening of kin discrimination mechanisms, such as colony-merger incompatibilities observed in M. xanthus. The findings reported here may thus have implications for understanding the evolution and maintenance of diversity in structured populations of soil microbes.
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Affiliation(s)
| | - I-Chen Kimberly Chen
- Department of Biology, Indiana University, Bloomington, IN 47405, USA Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland
| | - Kara Fitzpatrick
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Gregory J Velicer
- Department of Biology, Indiana University, Bloomington, IN 47405, USA Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland
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26
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Pérez J, Jiménez-Zurdo JI, Martínez-Abarca F, Millán V, Shimkets LJ, Muñoz-Dorado J. Rhizobial galactoglucan determines the predatory pattern of Myxococcus xanthus and protects Sinorhizobium meliloti from predation. Environ Microbiol 2014; 16:2341-50. [PMID: 24707988 PMCID: PMC4079745 DOI: 10.1111/1462-2920.12477] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 03/17/2014] [Accepted: 03/31/2014] [Indexed: 11/29/2022]
Abstract
Myxococcus xanthus is a social bacterium that preys on prokaryotic and eukaryotic microorganisms. Co-culture of M. xanthus with reference laboratory strains and field isolates of the legume symbiont Sinorhizobium meliloti revealed two different predatory patterns that resemble frontal and wolf-pack attacks. Use of mutants impaired in the two types of M. xanthus surface motility (A or adventurous and S or social motility) and a csgA mutant, which is unable to form macroscopic travelling waves known as ripples, has demonstrated that both motility systems but not rippling are required for efficient predation. To avoid frontal attack and reduce killing rates, rhizobial cells require a functional expR gene. ExpR regulates expression of genes involved in a variety of functions. The use of S. meliloti mutants impaired in several of these functions revealed that the exopolysaccharide galactoglucan (EPS II) is the major determinant of the M. xanthus predatory pattern. The data also suggest that this biopolymer confers an ecological advantage to rhizobial survival in soil, which may have broad environmental implications.
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Affiliation(s)
- Juana Pérez
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Avda. Fuentenueva s/n E-18071, Granada, Spain
| | - José I. Jiménez-Zurdo
- Grupo de Ecología Genética de la Rizosfera. Estación Experimental del Zaidín. Consejo Superior de Investigaciones Científicas (CSIC), Granada, Spain
| | - Francisco Martínez-Abarca
- Grupo de Ecología Genética de la Rizosfera. Estación Experimental del Zaidín. Consejo Superior de Investigaciones Científicas (CSIC), Granada, Spain
| | - Vicenta Millán
- Grupo de Ecología Genética de la Rizosfera. Estación Experimental del Zaidín. Consejo Superior de Investigaciones Científicas (CSIC), Granada, Spain
| | | | - José Muñoz-Dorado
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Avda. Fuentenueva s/n E-18071, Granada, Spain
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