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Radford EJ, Whitworth DE. The genetic basis of predation by myxobacteria. Adv Microb Physiol 2024; 85:1-55. [PMID: 39059819 DOI: 10.1016/bs.ampbs.2024.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2024]
Abstract
Myxobacteria (phylum Myxococcota) are abundant and virtually ubiquitous microbial predators. Facultatively multicellular organisms, they are able to form multicellular fruiting bodies and swarm across surfaces, cooperatively hunting for prey. Myxobacterial communities are able to kill a wide range of prey microbes, assimilating their biomass to fuel population growth. Their mechanism of predation is exobiotic - hydrolytic enzymes and toxic metabolites are secreted into the extracellular environment, killing and digesting prey cells from without. However, recent observations of single-cell predation and contact-dependent prey killing challenge the dogma of myxobacterial predation being obligately cooperative. Regardless of their predatory mechanisms, myxobacteria have a broad prey range, which includes Gram-negative bacteria, Gram-positive bacteria and fungi. Pangenome analyses have shown that their extremely large genomes are mainly composed of accessory genes, which are not shared by all members of their species. It seems that the diversity of accessory genes in different strains provides the breadth of activity required to prey upon such a smorgasbord of microbes, and also explains the considerable strain-to-strain variation in predatory efficiency against specific prey. After providing a short introduction to general features of myxobacterial biology which are relevant to predation, this review brings together a rapidly growing body of work into the molecular mechanisms and genetic basis of predation, presenting a summary of current knowledge, highlighting trends in research and suggesting strategies by which we can potentially exploit myxobacterial predation in the future.
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Affiliation(s)
- Emily J Radford
- Department of Life Sciences, Aberystwyth University, Aberystwyth, Ceredigion, United Kingdom
| | - David E Whitworth
- Department of Life Sciences, Aberystwyth University, Aberystwyth, Ceredigion, United Kingdom.
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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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Contreras-Moreno FJ, Moraleda-Muñoz A, Marcos-Torres FJ, Cuéllar V, Soto MJ, Pérez J, Muñoz-Dorado J. Siderophores and competition for iron govern myxobacterial predation dynamics. THE ISME JOURNAL 2024; 18:wrae077. [PMID: 38696719 PMCID: PMC11388931 DOI: 10.1093/ismejo/wrae077] [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: 03/23/2024] [Revised: 04/23/2024] [Accepted: 04/29/2024] [Indexed: 05/04/2024]
Abstract
Bacterial predators are decisive organisms that shape microbial ecosystems. In this study, we investigated the role of iron and siderophores during the predatory interaction between two rhizosphere bacteria: Myxococcus xanthus, an epibiotic predator, and Sinorhizobium meliloti, a bacterium that establishes nitrogen-fixing symbiosis with legumes. The results show that iron enhances the motility of the predator and facilitates its predatory capability, and that intoxication by iron is not used by the predator to prey, although oxidative stress increases in both bacteria during predation. However, competition for iron plays an important role in the outcome of predatory interactions. Using combinations of predator and prey mutants (nonproducers and overproducers of siderophores), we have investigated the importance of competition for iron in predation. The results demonstrate that the competitor that, via the production of siderophores, obtains sufficient iron for growth and depletes metal availability for the opponent will prevail in the interaction. Consequently, iron fluctuations in soils may modify the composition of microbial communities by altering the activity of myxobacterial predators. In addition, siderophore overproduction during predation can alter soil properties, affecting the productivity and sustainability of agricultural operations.
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Affiliation(s)
| | - Aurelio Moraleda-Muñoz
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, E-18071 Granada, Spain
| | | | - Virginia Cuéllar
- Departamento de Biotecnología y Protección Ambiental, Estación Experimental del Zaidín, CSIC, E-18008 Granada, Spain
| | - María José Soto
- Departamento de Biotecnología y Protección Ambiental, Estación Experimental del Zaidín, CSIC, E-18008 Granada, Spain
| | - Juana Pérez
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, E-18071 Granada, Spain
| | - José Muñoz-Dorado
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, E-18071 Granada, Spain
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Santamaría RI, Martínez-Carrasco A, Tormo JR, Martín J, Genilloud O, Reyes F, Díaz M. Interactions of Different Streptomyces Species and Myxococcus xanthus Affect Myxococcus Development and Induce the Production of DK-Xanthenes. Int J Mol Sci 2023; 24:15659. [PMID: 37958645 PMCID: PMC10649082 DOI: 10.3390/ijms242115659] [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: 09/19/2023] [Revised: 10/19/2023] [Accepted: 10/24/2023] [Indexed: 11/15/2023] Open
Abstract
The co-culturing of microorganisms is a well-known strategy to study microbial interactions in the laboratory. This approach facilitates the identification of new signals and molecules produced by one species that affects other species' behavior. In this work, we have studied the effects of the interaction of nine Streptomyces species (S. albidoflavus, S. ambofaciens, S. argillaceus, S. griseus, S. lividans, S. olivaceus, S. parvulus, S. peucetius, and S. rochei) with the predator bacteria Myxococcus xanthus, five of which (S. albidoflavus, S. griseus, S. lividans, S. olivaceus, and S. argillaceus) induce mound formation of M. xanthus on complex media (Casitone Yeast extract (CYE) and Casitone tris (CTT); media on which M. xanthus does not form these aggregates under normal culture conditions. An in-depth study on S. griseus-M. xanthus interactions (the Streptomyces strain producing the strongest effect) has allowed the identification of two siderophores produced by S. griseus, demethylenenocardamine and nocardamine, responsible for this grouping effect over M. xanthus. Experiments using pure commercial nocardamine and different concentrations of FeSO4 show that iron depletion is responsible for the behavior of M. xanthus. Additionally, it was found that molecules, smaller than 3 kDa, produced by S. peucetius can induce the production of DK-xanthenes by M. xanthus.
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Affiliation(s)
- Ramón I. Santamaría
- Instituto de Biología Funcional y Genómica (IBFG), Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Salamanca, C/Zacarías González, nº 2, 37007 Salamanca, Spain;
| | - Ana Martínez-Carrasco
- Instituto de Biología Funcional y Genómica (IBFG), Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Salamanca, C/Zacarías González, nº 2, 37007 Salamanca, Spain;
| | - José R. Tormo
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucía, Avda. del Conocimiento 34, 18016 Granada, Spain; (J.R.T.); (J.M.); (O.G.); (F.R.)
| | - Jesús Martín
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucía, Avda. del Conocimiento 34, 18016 Granada, Spain; (J.R.T.); (J.M.); (O.G.); (F.R.)
| | - Olga Genilloud
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucía, Avda. del Conocimiento 34, 18016 Granada, Spain; (J.R.T.); (J.M.); (O.G.); (F.R.)
| | - Fernando Reyes
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucía, Avda. del Conocimiento 34, 18016 Granada, Spain; (J.R.T.); (J.M.); (O.G.); (F.R.)
| | - Margarita Díaz
- Instituto de Biología Funcional y Genómica (IBFG), Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Salamanca, C/Zacarías González, nº 2, 37007 Salamanca, Spain;
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Granada Agudelo M, Ruiz B, Capela D, Remigi P. The role of microbial interactions on rhizobial fitness. FRONTIERS IN PLANT SCIENCE 2023; 14:1277262. [PMID: 37877089 PMCID: PMC10591227 DOI: 10.3389/fpls.2023.1277262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 09/22/2023] [Indexed: 10/26/2023]
Abstract
Rhizobia are soil bacteria that can establish a nitrogen-fixing symbiosis with legume plants. As horizontally transmitted symbionts, the life cycle of rhizobia includes a free-living phase in the soil and a plant-associated symbiotic phase. Throughout this life cycle, rhizobia are exposed to a myriad of other microorganisms that interact with them, modulating their fitness and symbiotic performance. In this review, we describe the diversity of interactions between rhizobia and other microorganisms that can occur in the rhizosphere, during the initiation of nodulation, and within nodules. Some of these rhizobia-microbe interactions are indirect, and occur when the presence of some microbes modifies plant physiology in a way that feeds back on rhizobial fitness. We further describe how these interactions can impose significant selective pressures on rhizobia and modify their evolutionary trajectories. More extensive investigations on the eco-evolutionary dynamics of rhizobia in complex biotic environments will likely reveal fascinating new aspects of this well-studied symbiotic interaction and provide critical knowledge for future agronomical applications.
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Affiliation(s)
- Margarita Granada Agudelo
- Laboratoire des Interactions Plantes Microbes Environnement (LIPME), Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | - Bryan Ruiz
- Laboratoire des Interactions Plantes Microbes Environnement (LIPME), Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | - Delphine Capela
- Laboratoire des Interactions Plantes Microbes Environnement (LIPME), Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | - Philippe Remigi
- Laboratoire des Interactions Plantes Microbes Environnement (LIPME), Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
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Soto MJ, Pérez J, Muñoz-Dorado J, Contreras-Moreno FJ, Moraleda-Muñoz A. Transcriptomic response of Sinorhizobium meliloti to the predatory attack of Myxococcus xanthus. Front Microbiol 2023; 14:1213659. [PMID: 37405170 PMCID: PMC10315480 DOI: 10.3389/fmicb.2023.1213659] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 06/01/2023] [Indexed: 07/06/2023] Open
Abstract
Bacterial predation impacts microbial community structures, which can have both positive and negative effects on plant and animal health and on environmental sustainability. Myxococcus xanthus is an epibiotic soil predator with a broad range of prey, including Sinorhizobium meliloti, which establishes nitrogen-fixing symbiosis with legumes. During the M. xanthus-S. meliloti interaction, the predator must adapt its transcriptome to kill and lyse the target (predatosome), and the prey must orchestrate a transcriptional response (defensome) to protect itself against the biotic stress caused by the predatory attack. Here, we describe the transcriptional changes taking place in S. meliloti in response to myxobacterial predation. The results indicate that the predator induces massive changes in the prey transcriptome with up-regulation of protein synthesis and secretion, energy generation, and fatty acid (FA) synthesis, while down-regulating genes required for FA degradation and carbohydrate transport and metabolism. The reconstruction of up-regulated pathways suggests that S. meliloti modifies the cell envelop by increasing the production of different surface polysaccharides (SPSs) and membrane lipids. Besides the barrier role of SPSs, additional mechanisms involving the activity of efflux pumps and the peptide uptake transporter BacA, together with the production of H2O2 and formaldehyde have been unveiled. Also, the induction of the iron-uptake machinery in both predator and prey reflects a strong competition for this metal. With this research we complete the characterization of the complex transcriptional changes that occur during the M. xanthus-S. meliloti interaction, which can impact the establishment of beneficial symbiosis with legumes.
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Affiliation(s)
- María José Soto
- Departamento de Biotecnología y Protección Ambiental, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - Juana Pérez
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Granada, Spain
| | - José Muñoz-Dorado
- 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
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Phillips KE, Akbar S, Stevens DC. Concepts and conjectures concerning predatory performance of myxobacteria. Front Microbiol 2022; 13:1031346. [PMID: 36246230 PMCID: PMC9556981 DOI: 10.3389/fmicb.2022.1031346] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 09/14/2022] [Indexed: 01/28/2023] Open
Abstract
Myxobacteria are excellent model organisms for investigation of predator-prey interactions and predatory shaping of microbial communities. This review covers interdisciplinary topics related to myxobacterial predation and provides current concepts and challenges for determining predatory performance. Discussed topics include the role of specialized metabolites during predation, genetic determinants for predatory performance, challenges associated with methodological differences, discrepancies between sequenced and environmental myxobacteria, and factors that influence predation.
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Affiliation(s)
- Kayleigh E. Phillips
- Department of BioMolecular Sciences, The University of Mississippi, Oxford, MS, United States
| | - Shukria Akbar
- Division of Pharmaceutical Sciences, School of Pharmacy, University of Wisconsin-Madison, Madison, WI, United States,Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, United States
| | - D. Cole Stevens
- Department of BioMolecular Sciences, The University of Mississippi, Oxford, MS, United States,*Correspondence: D. Cole Stevens,
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Pérez J, Contreras-Moreno FJ, Muñoz-Dorado J, Moraleda-Muñoz A. Development versus predation: Transcriptomic changes during the lifecycle of Myxococcus xanthus. Front Microbiol 2022; 13:1004476. [PMID: 36225384 PMCID: PMC9548883 DOI: 10.3389/fmicb.2022.1004476] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 09/08/2022] [Indexed: 11/13/2022] Open
Abstract
Myxococcus xanthus is a multicellular bacterium with a complex lifecycle. It is a soil-dwelling predator that preys on a wide variety of microorganisms by using a group and collaborative epibiotic strategy. In the absence of nutrients this myxobacterium enters in a unique developmental program by using sophisticated and complex regulatory systems where more than 1,400 genes are transcriptional regulated to guide the community to aggregate into macroscopic fruiting bodies filled of environmentally resistant myxospores. Herein, we analyze the predatosome of M. xanthus, that is, the transcriptomic changes that the predator undergoes when encounters a prey. This study has been carried out using as a prey Sinorhizobium meliloti, a nitrogen fixing bacteria very important for the fertility of soils. The transcriptional changes include upregulation of genes that help the cells to detect, kill, lyse, and consume the prey, but also downregulation of genes not required for the predatory process. Our results have shown that, as expected, many genes encoding hydrolytic enzymes and enzymes involved in biosynthesis of secondary metabolites increase their expression levels. Moreover, it has been found that the predator modifies its lipid composition and overproduces siderophores to take up iron. Comparison with developmental transcriptome reveals that M. xanthus downregulates the expression of a significant number of genes coding for regulatory elements, many of which have been demonstrated to be key elements during development. This study shows for the first time a global view of the M. xanthus lifecycle from a transcriptome perspective.
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Akbar S, Stevens DC. Functional genomics study of Pseudomonas putida to determine traits associated with avoidance of a myxobacterial predator. Sci Rep 2021; 11:16445. [PMID: 34385565 PMCID: PMC8360965 DOI: 10.1038/s41598-021-96046-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 07/28/2021] [Indexed: 12/13/2022] Open
Abstract
Predation contributes to the structure and diversity of microbial communities. Predatory myxobacteria are ubiquitous to a variety of microbial habitats and capably consume a broad diversity of microbial prey. Predator-prey experiments utilizing myxobacteria have provided details into predatory mechanisms and features that facilitate consumption of prey. However, prey resistance to myxobacterial predation remains underexplored, and prey resistances have been observed exclusively from predator-prey experiments that included the model myxobacterium Myxococcus xanthus. Utilizing a predator-prey pairing that instead included the myxobacterium, Cystobacter ferrugineus, with Pseudomonas putida as prey, we observed surviving phenotypes capable of eluding predation. Comparative transcriptomics between P. putida unexposed to C. ferrugineus and the survivor phenotype suggested that increased expression of efflux pumps, genes associated with mucoid conversion, and various membrane features contribute to predator avoidance. Unique features observed from the survivor phenotype when compared to the parent P. putida include small colony variation, efflux-mediated antibiotic resistance, phenazine-1-carboxylic acid production, and increased mucoid conversion. These results demonstrate the utility of myxobacterial predator-prey models and provide insight into prey resistances in response to predatory stress that might contribute to the phenotypic diversity and structure of bacterial communities.
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Affiliation(s)
- Shukria Akbar
- Department of BioMolecular Sciences, University of Mississippi, University, MS, USA
| | - D Cole Stevens
- Department of BioMolecular Sciences, University of Mississippi, University, MS, USA.
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Li YP, Fekih IB, Fru EC, Moraleda-Munoz A, Li X, Rosen BP, Yoshinaga M, Rensing C. Antimicrobial Activity of Metals and Metalloids. Annu Rev Microbiol 2021; 75:175-197. [PMID: 34343021 DOI: 10.1146/annurev-micro-032921-123231] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Competition shapes evolution. Toxic metals and metalloids have exerted selective pressure on life since the rise of the first organisms on the Earth, which has led to the evolution and acquisition of resistance mechanisms against them, as well as mechanisms to weaponize them. Microorganisms exploit antimicrobial metals and metalloids to gain competitive advantage over other members of microbial communities. This exerts a strong selective pressure that drives evolution of resistance. This review describes, with a focus on arsenic and copper, how microorganisms exploit metals and metalloids for predation and how metal- and metalloid-dependent predation may have been a driving force for evolution of microbial resistance against metals and metalloids. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Yuan Ping Li
- Institute of Environmental Microbiology, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 35002, China;
| | - Ibtissem Ben Fekih
- Institute of Environmental Microbiology, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 35002, China;
| | - Ernest Chi Fru
- Centre for Geobiology and Geochemistry, School of Earth and Ocean Sciences, Cardiff University, CF10 3AT Cardiff, United Kingdom
| | - Aurelio Moraleda-Munoz
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Granada 18071, Spain
| | - Xuanji Li
- Department of Biology, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Barry P Rosen
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida 33199, USA
| | - Masafumi Yoshinaga
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida 33199, USA
| | - Christopher Rensing
- Institute of Environmental Microbiology, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 35002, China;
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Solís-Moreno CA, Cervantes-González E, Saavedra-Leos MZ. Use and treatment of chicken feathers as a natural adsorbent for the removal of copper in aqueous solution. JOURNAL OF ENVIRONMENTAL HEALTH SCIENCE & ENGINEERING 2021; 19:707-720. [PMID: 34150268 PMCID: PMC8172749 DOI: 10.1007/s40201-021-00639-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 02/18/2021] [Indexed: 06/12/2023]
Abstract
PURPOSE Copper is a heavy metal that causes considerable deterioration to human health and ecosystems, so their elimination in water bodies is of great interest. Present investigation shows the efficiency of chicken feather as a natural adsorbent and its subsequent degradation in order to have an integral treatment and avoid the unconscious disposition. METHODS Optimal conditions of adsorption process were determined using the Response Surface Methodology (RSM)-Box-Behnken design (BBD) with three variables (pH, temperature and adsorbent dose). After that, the optimal conditions were used to analize the adsorption isotherms by Langmuir, Freundlich and Temkin models; also thermodynamics parameters Gibbs free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) were obtained. Finally, the biodegradation of the residue denominated "adsorbent-adsorbate" complex was evaluated through monitoring the soluble protein production, keratinolytic activity, ninhydrin positive products, sulfhydryl groups, and gravimetrically analysis. RESULTS The optimum conditions for the adsorption were 30°C and pH 3, the Langmuir model was better described the adsorption process at 30°C, while at 40°C was Temkin model. The chicken feather turned out a natural adsorbent competitive with respect to others used in the removal of copper in liquid systems; obtaining qmax of 7.84 and 11.48 mg/g at 30 and 40°C, respectively; it was also a favorable and spontaneous process. Finally the adsorbent used was degraded by a keratinolytic consortium. CONCLUSIONS In this study, chicken feather was used as a low cost adsorbent for copper efficiently and with the feasibility that the adsorbent can be biodegraded and release the metal.
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Affiliation(s)
- C. A. Solís-Moreno
- Universidad Autónoma de San Luis Potosí, Coordinación Académica Región Altiplano, Carretera a Cedral Km 5+600, San José de las Trojes, Matehuala, 78700 San Luis Potosí, México
| | - E. Cervantes-González
- Universidad Autónoma de San Luis Potosí, Coordinación Académica Región Altiplano, Carretera a Cedral Km 5+600, San José de las Trojes, Matehuala, 78700 San Luis Potosí, México
| | - M. Z. Saavedra-Leos
- Universidad Autónoma de San Luis Potosí, Coordinación Académica Región Altiplano, Carretera a Cedral Km 5+600, San José de las Trojes, Matehuala, 78700 San Luis Potosí, México
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12
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Peng W, Yang X, Yan K, Chen H, Yuan F, Bei W. CopA Protects Actinobacillus pleuropneumoniae against Copper Toxicity. Vet Microbiol 2021; 258:109122. [PMID: 34052743 DOI: 10.1016/j.vetmic.2021.109122] [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: 10/18/2020] [Accepted: 05/13/2021] [Indexed: 11/24/2022]
Abstract
Actinobacillus pleuropneumoniae is a Gram-negative bacterium causing porcine pleuropneumonia and severe economic losses in the global swine industry. The toxic trace element copper is required for many physiological and pathological processes in organisms. However, CopA, one of the most well-characterized P-type ATPases contributing to copper resistance, has not been characterized in A. pleuropneumoniae. We used quantitative PCR analysis to examine expression of the copA gene in A. pleuropneumoniae and investigated sequence conservation among serotypes and other Gram-negative bacteria. Growth characteristics were determined using growth curve analyses and spot dilution assays of the wild-type strain and a △copA mutant. We also used flame atomic absorption spectrophotometry to determine intracellular copper content and examined the virulence of the △copA mutant in a mouse model. The copA expression was induced by copper, and its nucleotide sequence was highly conserved among different serotypes of A. pleuropneumoniae. The amino acid sequence of CopA shared high identity with CopA sequences reported from several Gram-negative bacteria. Furthermore, the △copA mutant exhibited impaired growth and had higher intracellular copper content compared with the wild-type strain when supplemented with copper. The mouse model revealed that CopA had no influence on the virulence of A. pleuropneumoniae. In conclusion, these results demonstrated that CopA is required for resistance of A. pleuropneumoniae to copper and protects A. pleuropneumoniae against copper toxicity via copper efflux.
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Affiliation(s)
- Wei Peng
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Xia Yang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Kang Yan
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Huanchun Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Fangyan Yuan
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture), Institute of Animal Husbandry and Veterinary Sciences, Hubei Academy of Agricultural Sciences, Wuhan, China.
| | - Weicheng Bei
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China; State Key Laboratory of Genetically Engineered Veterinary Vaccines, Qingdao, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China.
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13
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Sydney N, Swain MT, So JMT, Hoiczyk E, Tucker NP, Whitworth DE. The Genetics of Prey Susceptibility to Myxobacterial Predation: A Review, Including an Investigation into Pseudomonas aeruginosa Mutations Affecting Predation by Myxococcus xanthus. Microb Physiol 2021; 31:57-66. [PMID: 33794538 DOI: 10.1159/000515546] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 02/22/2021] [Indexed: 11/19/2022]
Abstract
Bacterial predation is a ubiquitous and fundamental biological process, which influences the community composition of microbial ecosystems. Among the best characterised bacterial predators are the myxobacteria, which include the model organism Myxococcus xanthus. Predation by M. xanthus involves the secretion of antibiotic metabolites and hydrolytic enzymes, which results in the lysis of prey organisms and release of prey nutrients into the extracellular milieu. Due to the generalist nature of this predatory mechanism, M. xanthus has a broad prey range, being able to kill and consume Gram-negative/positive bacteria and fungi. Potential prey organisms have evolved a range of behaviours which protect themselves from attack by predators. In recent years, several investigations have studied the molecular responses of a broad variety of prey organisms to M. xanthus predation. It seems that the diverse mechanisms employed by prey belong to a much smaller number of general "predation resistance" strategies. In this mini-review, we present the current state of knowledge regarding M. xanthus predation, and how prey organisms resist predation. As previous molecular studies of prey susceptibility have focussed on individual genes/metabolites, we have also undertaken a genome-wide screen for genes of Pseudomonas aeruginosa which contribute to its ability to resist predation. P. aeruginosa is a World Health Organisation priority 1 antibiotic-resistant pathogen. It is metabolically versatile and has an array of pathogenic mechanisms, leading to its prevalence as an opportunistic pathogen. Using a library of nearly 5,500 defined transposon insertion mutants, we screened for "prey genes", which when mutated allowed increased predation by a fluorescent strain of M. xanthus. A set of candidate "prey proteins" were identified, which shared common functional roles and whose nature suggested that predation resistance by P. aeruginosa requires an effective metal/oxidative stress system, an intact motility system, and mechanisms for de-toxifying antimicrobial peptides.
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Affiliation(s)
- Natashia Sydney
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, United Kingdom
| | - Martin T Swain
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, United Kingdom
| | - Jeffery M T So
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
| | - Egbert Hoiczyk
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
| | - Nicholas P Tucker
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - David E Whitworth
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, United Kingdom
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14
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Galeb HA, Wilkinson EL, Stowell AF, Lin H, Murphy ST, Martin‐Hirsch PL, Mort RL, Taylor AM, Hardy JG. Melanins as Sustainable Resources for Advanced Biotechnological Applications. GLOBAL CHALLENGES (HOBOKEN, NJ) 2021; 5:2000102. [PMID: 33552556 PMCID: PMC7857133 DOI: 10.1002/gch2.202000102] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 11/04/2020] [Indexed: 05/17/2023]
Abstract
Melanins are a class of biopolymers that are widespread in nature and have diverse origins, chemical compositions, and functions. Their chemical, electrical, optical, and paramagnetic properties offer opportunities for applications in materials science, particularly for medical and technical uses. This review focuses on the application of analytical techniques to study melanins in multidisciplinary contexts with a view to their use as sustainable resources for advanced biotechnological applications, and how these may facilitate the achievement of the United Nations Sustainable Development Goals.
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Affiliation(s)
- Hanaa A. Galeb
- Department of ChemistryLancaster UniversityLancasterLA1 4YBUK
- Department of ChemistryScience and Arts CollegeRabigh CampusKing Abdulaziz UniversityJeddah21577Saudi Arabia
| | - Emma L. Wilkinson
- Department of Biomedical and Life SciencesLancaster UniversityLancasterLA1 4YGUK
| | - Alison F. Stowell
- Department of Organisation, Work and TechnologyLancaster University Management SchoolLancaster UniversityLancasterLA1 4YXUK
| | - Hungyen Lin
- Department of EngineeringLancaster UniversityLancasterLA1 4YWUK
| | - Samuel T. Murphy
- Department of EngineeringLancaster UniversityLancasterLA1 4YWUK
- Materials Science InstituteLancaster UniversityLancasterLA1 4YBUK
| | - Pierre L. Martin‐Hirsch
- Lancashire Teaching Hospitals NHS TrustRoyal Preston HospitalSharoe Green LanePrestonPR2 9HTUK
| | - Richard L. Mort
- Department of Biomedical and Life SciencesLancaster UniversityLancasterLA1 4YGUK
| | - Adam M. Taylor
- Lancaster Medical SchoolLancaster UniversityLancasterLA1 4YWUK
| | - John G. Hardy
- Department of ChemistryLancaster UniversityLancasterLA1 4YBUK
- Materials Science InstituteLancaster UniversityLancasterLA1 4YBUK
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15
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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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