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Microbial Physiology 2021Predatory bacteria gained interest in the last 20 years. Nevertheless, only a few species are well characterized. The endobiotic predator Bdellovibrio bacteriovorus... (Review)
Review
Predatory bacteria gained interest in the last 20 years. Nevertheless, only a few species are well characterized. The endobiotic predator Bdellovibrio bacteriovorus invades its prey to consume it from the inside, whereas Myxococcus xanthus hunts as a whole group to overcome its prey. Both species were described to prey on cyanobacteria as well. This minireview summarizes the findings of the last 20 years of predatory bacteria of cyanobacteria and is supplemented by new findings from a screening experiment for bacterial predators of the model organism Anabaena variabilis PCC 7937. Known predatory bacteria of cyanobacteria belong to the phyla Proteobacteria, Bacteroidetes, and Firmicutes and follow different hunting strategies. The underlying mechanisms are in most cases not known in much detail. Isolates from the screening experiment were clustered after predation behaviour and analyzed with respect to their size. The effect of predation in high nitrate levels and the occurrence of nitrogen-fixing cells, called heterocysts, are addressed.
Topics: Animals; Bdellovibrio bacteriovorus; Cyanobacteria; Myxococcus xanthus; Predatory Behavior
PubMed: 34010833
DOI: 10.1159/000516427 -
Current Opinion in Cell Biology Jun 2022Bacterial cells are spatiotemporally highly organised with proteins localising dynamically to distinct subcellular regions. Motility in the rod-shaped Myxococcus xanthus... (Review)
Review
Bacterial cells are spatiotemporally highly organised with proteins localising dynamically to distinct subcellular regions. Motility in the rod-shaped Myxococcus xanthus cells represents an example of signal-induced spatiotemporal regulation of cell polarity. M. xanthus cells move across surfaces with defined front-rear polarity; occasionally, they invert polarity and, in parallel, reverse direction of movement. The polarity module establishes front-rear polarity between reversals and consists of the Ras-like GTPase MglA and its cognate GEF and GAP, that all localise asymmetrically to the cell poles. The Frz chemosensory system constitutes the polarity inversion module and interfaces with the proteins of the polarity module, thereby triggering their polar repositioning. As a result, the polarity proteins, over time, toggle between the cell poles causing cells to oscillate irregularly. Here, we review recent progress in how front-rear polarity is established by the polarity module and inverted by the Frz system and highlight open questions for future studies.
Topics: Bacterial Proteins; Cell Polarity; GTP Phosphohydrolases; Myxococcus xanthus
PubMed: 35367928
DOI: 10.1016/j.ceb.2022.102076 -
Journal of Molecular Biology Nov 2015Prokaryotes often reside in groups where a high degree of relatedness has allowed the evolution of cooperative behaviors. However, very few bacteria or archaea have made... (Review)
Review
Prokaryotes often reside in groups where a high degree of relatedness has allowed the evolution of cooperative behaviors. However, very few bacteria or archaea have made the successful transition from unicellular to obligate multicellular life. A notable exception is the myxobacteria, in which cells cooperate to perform group functions highlighted by fruiting body development, an obligate multicellular function. Like all multicellular organisms, myxobacteria face challenges in how to organize and maintain multicellularity. These challenges include maintaining population homeostasis, carrying out tissue repair and regulating the behavior of non-cooperators. Here, we describe the major cooperative behaviors that myxobacteria use: motility, predation and development. In addition, this review emphasizes recent discoveries in the social behavior of outer membrane exchange, wherein kin share outer membrane contents. Finally, we review evidence that outer membrane exchange may be involved in regulating population homeostasis, thus serving as a social tool for myxobacteria to make the cyclic transitions from unicellular to multicellular states.
Topics: Bacterial Outer Membrane Proteins; Myxococcales
PubMed: 26254571
DOI: 10.1016/j.jmb.2015.07.022 -
Current Opinion in Microbiology Jun 2024Bacteria utilize type IV pili (T4P) to interact with their environment, where they facilitate processes including motility, adherence, and DNA uptake. T4P require... (Review)
Review
Bacteria utilize type IV pili (T4P) to interact with their environment, where they facilitate processes including motility, adherence, and DNA uptake. T4P require multisubunit, membrane-spanning nanomachines for assembly. The tight adherence (Tad) pili are an Archaea-derived T4P subgroup whose machinery exhibits significant mechanistic and architectural differences from bacterial type IVa and IVb pili. Most Tad biosynthetic genes are encoded in a single locus that is widespread in bacteria due to facile acquisition via horizontal gene transfer. These loci experience extensive structural rearrangements, including the acquisition of novel regulatory or biosynthetic genes, which fine-tune their function. This has permitted their integration into many different bacterial lifestyles, including the Caulobacter crescentus cell cycle, Myxococcus xanthus predation, and numerous plant and mammalian pathogens and symbionts.
Topics: Fimbriae, Bacterial; Caulobacter crescentus; Bacteria; Bacterial Adhesion; Gene Transfer, Horizontal; Fimbriae Proteins; Bacterial Proteins; Myxococcus xanthus
PubMed: 38579360
DOI: 10.1016/j.mib.2024.102468 -
Frontiers in Microbiology 2020Myxobacteria are ubiquitous in soil environments. They display a complex life cycle: vegetatively growing cells coordinate their motility to form multicellular swarms,... (Review)
Review
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 which can access nutrients from a broad spectrum of microorganisms. 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 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 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.
PubMed: 32010119
DOI: 10.3389/fmicb.2020.00002 -
Frontiers in Chemistry 2022Natural products derived from microorganisms play a prominent role in drug discovery as potential anti-infective agents. Over the past few decades, lipopeptides produced... (Review)
Review
Natural products derived from microorganisms play a prominent role in drug discovery as potential anti-infective agents. Over the past few decades, lipopeptides produced by particularly , , , and cyanobacteria species, have been extensively studied for their antimicrobial potential. Subsequently, daptomycin and polymyxin B were approved by the Food and Drug Administration as lipopeptide antibiotics. Recent studies have however, indicated that , and , as well as predatory bacteria such as , and , hold promise as relatively underexplored sources of novel classes of lipopeptides. This review will thus highlight the structures and the newly discovered scaffolds of lipopeptide families produced by these bacterial genera, with potential antimicrobial activities. Additionally, insight into the mode of action and biosynthesis of these lipopeptides will be provided and the application of a genome mining approach, to ascertain the biosynthetic gene cluster potential of these bacterial genera (genomes available on the National Center for Biotechnology Information) for their future pharmaceutical exploitation, will be discussed.
PubMed: 36277345
DOI: 10.3389/fchem.2022.1025979 -
Nature Communications Sep 2023Many species, such as fish schools or bird flocks, rely on collective motion to forage, prey, or escape predators. Likewise, Myxococcus xanthus forages and moves...
Many species, such as fish schools or bird flocks, rely on collective motion to forage, prey, or escape predators. Likewise, Myxococcus xanthus forages and moves collectively to prey and feed on other bacterial species. These activities require two distinct motility machines enabling adventurous (A) and social (S) gliding, however when and how these mechanisms are used has remained elusive. Here, we address this long-standing question by applying multiscale semantic cell tracking during predation. We show that: (1) foragers and swarms can comprise A- and S-motile cells, with single cells exchanging frequently between these groups; (2) A-motility is critical to ensure the directional movement of both foragers and swarms; (3) the combined action of A- and S-motile cells within swarms leads to increased predation efficiencies. These results challenge the notion that A- and S-motilities are exclusive to foragers and swarms, and show that these machines act synergistically to enhance predation efficiency.
Topics: Animals; Predatory Behavior; Cell Tracking; Cooperative Behavior; Motion; Myxococcus xanthus
PubMed: 37696789
DOI: 10.1038/s41467-023-41193-x -
Viruses Jul 2018Bacteriophages have been used as molecular tools in fundamental biology investigations for decades. Beyond this, however, they play a crucial role in the... (Review)
Review
Bacteriophages have been used as molecular tools in fundamental biology investigations for decades. Beyond this, however, they play a crucial role in the eco-evolutionary dynamics of bacterial communities through their demographic impact and the source of genetic information they represent. The increasing interest in describing ecological and evolutionary aspects of bacteria⁻phage interactions has led to major insights into their fundamental characteristics, including arms race dynamics and acquired bacterial immunity. Here, we review knowledge on the phages of the myxobacteria with a major focus on phages infecting , a bacterial model system widely used to study developmental biology and social evolution. In particular, we focus upon the isolation of myxophages from natural sources and describe the morphology and life cycle parameters, as well as the molecular genetics and genomics of the major groups of myxophages. Finally, we propose several interesting research directions which focus on the interplay between myxobacterial host sociality and bacteria⁻phage interactions.
Topics: Bacteriophages; Evolution, Molecular; Gene Expression Regulation, Bacterial; Genome, Viral; Myxococcus xanthus; Sewage; Soil Microbiology
PubMed: 30021959
DOI: 10.3390/v10070374 -
Microorganisms Jun 2023Predatory bacteria, along with the biology of their predatory behavior, have attracted interest in terms of their ecological significance and industrial applications, a... (Review)
Review
Predatory bacteria, along with the biology of their predatory behavior, have attracted interest in terms of their ecological significance and industrial applications, a trend that has been even more pronounced since the comprehensive review in 2016. This mini-review does not cover research trends, such as the role of outer membrane vesicles in myxobacterial predation, but provides an overview of the classification and newly described taxa of predatory bacteria since 2016, particularly with regard to phylogenetic aspects. Among them, it is noteworthy that in 2020 there was a major phylogenetic reorganization that the taxa hosting and , formerly classified as , were proposed as the new phyla and , respectively. Predatory bacteria have been reported from other phyla, especially from the candidate divisions. Predatory bacteria that prey on cyanobacteria and predatory cyanobacteria that prey on have also been found. These are also covered in this mini-review, and trans-phylum phylogenetic trees are presented.
PubMed: 37512846
DOI: 10.3390/microorganisms11071673 -
Microbiology (Reading, England) Jan 2016Myxococcus xanthus is a predatory bacterium and a model system for social behaviour in bacteria. Myx. xanthus forms thin biofilms, where cells work together to colonize... (Review)
Review
Myxococcus xanthus is a predatory bacterium and a model system for social behaviour in bacteria. Myx. xanthus forms thin biofilms, where cells work together to colonize new territory, invade prey colonies and lyse prey cells. Prey-cell lysis occurs at close proximity, and utilizes antibiotics such as myxovirescin, hydrolytic enzymes such as the protease MepA and extracellular outer-membrane vesicles that may facilitate delivery. Many questions about the mechanism of prey lysis remain, as well as a complete understanding of the vast hydrolytic and secondary metabolite potential present in the Myx. xanthus genome. However, it is clear that predation presents unique challenges for this bacterium, which are solved, in part, through the social behaviours at the disposal of Myx. xanthus. Here, we discuss the life cycle of Myx. xanthus, and the hypothesis that multicellular behaviour in this organism is critical to, and derives from, the challenges of growth as a bacterial predator.
Topics: Bacterial Proteins; Myxococcus xanthus; Spores, Fungal
PubMed: 26518442
DOI: 10.1099/mic.0.000208