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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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Pasternak Z, Njagi M, Shani Y, Chanyi R, Rotem O, Lurie-Weinberger MN, Koval S, Pietrokovski S, Gophna U, Jurkevitch E. In and out: an analysis of epibiotic vs periplasmic bacterial predators. THE ISME JOURNAL 2014; 8:625-635. [PMID: 24088628 PMCID: PMC3930308 DOI: 10.1038/ismej.2013.164] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 07/14/2013] [Accepted: 08/17/2013] [Indexed: 01/17/2023]
Abstract
Bdellovibrio and like organisms (BALO) are obligate predators of Gram-negative bacteria, belonging to the α- and δ-proteobacteria. BALO prey using either a periplasmic or an epibiotic predatory strategy, but the genetic background underlying these phenotypes is not known. Here we compare the epibiotic Bdellovibrio exovorus and Micavibrio aeruginosavorus to the periplasmic B. bacteriovorus and Bacteriovorax marinus. Electron microscopy showed that M. aeruginosavorus, but not B. exovorus, can attach to prey cells in a non-polar manner through its longitudinal side. Both these predators were resistant to a surprisingly high number of antibiotic compounds, possibly via 26 and 19 antibiotic-resistance genes, respectively, most of them encoding efflux pumps. Comparative genomic analysis of all the BALOs revealed that epibiotic predators have a much smaller genome (ca. 2.5 Mbp) than the periplasmic predators (ca. 3.5 Mbp). Additionally, periplasmic predators have, on average, 888 more proteins, at least 60% more peptidases, and one more rRNA operon. Fifteen and 219 protein families were specific to the epibiotic and the periplasmic predators, respectively, the latter clearly forming the core of the periplasmic 'predatome', which is upregulated during the growth phase. Metabolic deficiencies of epibiotic genomes include the synthesis of inosine, riboflavin, vitamin B6 and the siderophore aerobactin. The phylogeny of the epibiotic predators suggests that they evolved by convergent evolution, with M. aeruginosavorus originating from a non-predatory ancestor while B. exovorus evolved from periplasmic predators by gene loss.
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Affiliation(s)
- Z Pasternak
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, Israel.
| | - M Njagi
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, Israel
| | - Y Shani
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, Israel
| | - R Chanyi
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
| | - O Rotem
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, Israel
| | - M N Lurie-Weinberger
- Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - S Koval
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
| | - S Pietrokovski
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - U Gophna
- Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - E Jurkevitch
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, Israel
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Association of a D-alanyl-D-alanine carboxypeptidase gene with the formation of aberrantly shaped cells during the induction of viable but nonculturable Vibrio parahaemolyticus. Appl Environ Microbiol 2013; 79:7305-12. [PMID: 24056454 DOI: 10.1128/aem.01723-13] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vibrio parahaemolyticus is a halophilic Gram-negative bacterium that causes human gastroenteritis. When the viable but nonculturable (VBNC) state of this bacterium was induced by incubation at 4°C in Morita minimal salt solution containing 0.5% NaCl, the rod-shaped cells became coccoid, and various aberrantly shaped intermediates were formed in the initial stage. This study examined the factors that influence the formation of these aberrantly shaped cells. The proportion of aberrantly shaped cells was not affected in a medium containing D-cycloserine (50 μg/ml) but was lower in a medium containing cephalosporin C (10 μg/ml) than in the control medium without antibiotics. The proportion of aberrantly shaped cells was higher in a culture medium that contained 0.5% NaCl than in culture media containing 1.0 or 1.5% NaCl. The expression of 15 of 17 selected genes associated with cell wall synthesis was enhanced, and the expression of VP2468 (dacB), which encodes D-alanyl-D-alanine carboxypeptidase, was enhanced the most. The proportion of aberrantly shaped cells was significantly lower in the dacB mutant strain than in the parent strain, but the proportion was restored in the presence of the complementary dacB gene. This study suggests that disturbance of the dynamics of cell wall synthesis by enhanced expression of the VP2468 gene is associated with the formation of aberrantly shaped cells in the initial stage of induction of VBNC V. parahaemolyticus cells under specific conditions.
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Dwidar M, Monnappa AK, Mitchell RJ. The dual probiotic and antibiotic nature of Bdellovibrio bacteriovorus. BMB Rep 2012; 45:71-8. [DOI: 10.5483/bmbrep.2012.45.2.71] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Lerner TR, Lovering AL, Bui NK, Uchida K, Aizawa SI, Vollmer W, Sockett RE. Specialized peptidoglycan hydrolases sculpt the intra-bacterial niche of predatory Bdellovibrio and increase population fitness. PLoS Pathog 2012; 8:e1002524. [PMID: 22346754 PMCID: PMC3276566 DOI: 10.1371/journal.ppat.1002524] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 12/21/2011] [Indexed: 11/18/2022] Open
Abstract
Bdellovibrio are predatory bacteria that have evolved to invade virtually all Gram-negative bacteria, including many prominent pathogens. Upon invasion, prey bacteria become rounded up into an osmotically stable niche for the Bdellovibrio, preventing further superinfection and allowing Bdellovibrio to replicate inside without competition, killing the prey bacterium and degrading its contents. Historically, prey rounding was hypothesized to be associated with peptidoglycan (PG) metabolism; we found two Bdellovibrio genes, bd0816 and bd3459, expressed at prey entry and encoding proteins with limited homologies to conventional dacB/PBP4 DD-endo/carboxypeptidases (responsible for peptidoglycan maintenance during growth and division). We tested possible links between Bd0816/3459 activity and predation. Bd3459, but not an active site serine mutant protein, bound β-lactam, exhibited DD-endo/carboxypeptidase activity against purified peptidoglycan and, importantly, rounded up E. coli cells upon periplasmic expression. A ΔBd0816 ΔBd3459 double mutant invaded prey more slowly than the wild type (with negligible prey cell rounding) and double invasions of single prey by more than one Bdellovibrio became more frequent. We solved the crystal structure of Bd3459 to 1.45 Å and this revealed predation-associated domain differences to conventional PBP4 housekeeping enzymes (loss of the regulatory domain III, alteration of domain II and a more exposed active site). The Bd3459 active site (and by similarity the Bd0816 active site) can thus accommodate and remodel the various bacterial PGs that Bdellovibrio may encounter across its diverse prey range, compared to the more closed active site that “regular” PBP4s have for self cell wall maintenance. Therefore, during evolution, Bdellovibrio peptidoglycan endopeptidases have adapted into secreted predation-specific proteins, preventing wasteful double invasion, and allowing activity upon the diverse prey peptidoglycan structures to sculpt the prey cell into a stable intracellular niche for replication. Bdellovibrio bacteriovorus is a small predatory bacterium that invades other bacteria including pathogens of humans and animals. Bdellovibrio digest the pathogens from within, growing at their expense. Bdellovibrio do not attack human, plant or animal cells and so could be applied as “living antibiotics”. Here we have discovered how Bdellovibrio evolved to live inside other bacteria. Evolution has changed (normally housekeeping) genes called dacBs so that their products recognise and modify the different cell walls of a wide range of bacteria. Their action sculpts the cell walls of the invaded bacteria to make a stable “home” for the Bdellovibrio, inside which it kills them. We know the structure and activity of the enzymes and that mutants without them are not as efficient predators. This is relevant to antibacterial therapies because the predatory DacB enzymes themselves act against bacteria and are also a key factor in Bdellovibrio cells being live predators of pathogens.
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Affiliation(s)
- Thomas R. Lerner
- Centre for Genetics and Genomics, School of Biology, University of Nottingham, Medical School, Nottingham, United Kingdom
| | - Andrew L. Lovering
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Nhat Khai Bui
- The Centre for Bacterial Cell Biology, Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Kaoru Uchida
- Department of Life Sciences, Prefectural University of Hiroshima, Shobara, Hiroshima, Japan
| | - Shin-Ichi Aizawa
- Department of Life Sciences, Prefectural University of Hiroshima, Shobara, Hiroshima, Japan
| | - Waldemar Vollmer
- The Centre for Bacterial Cell Biology, Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - R. Elizabeth Sockett
- Centre for Genetics and Genomics, School of Biology, University of Nottingham, Medical School, Nottingham, United Kingdom
- * E-mail:
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Three-dimensional imaging of the highly bent architecture of Bdellovibrio bacteriovorus by using cryo-electron tomography. J Bacteriol 2008; 190:2588-96. [PMID: 18203829 DOI: 10.1128/jb.01538-07] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bdellovibrio bacteriovorus cells are small deltaproteobacterial cells that feed on other gram-negative bacteria, including human pathogens. Using cryo-electron tomography, we demonstrated that B. bacteriovorus cells are capable of substantial flexibility and local deformation of the outer and inner membranes without loss of cell integrity. These shape changes can occur in less than 2 min, and analysis of the internal architecture of highly bent cells showed that the overall distribution of molecular machines and the nucleoid is similar to that in moderately bent cells. B. bacteriovorus cells appear to contain an extensive internal network of short and long filamentous structures. We propose that rearrangements of these structures, in combination with the unique properties of the cell envelope, may underlie the remarkable ability of B. bacteriovorus cells to find and enter bacterial prey.
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A Predatory Patchwork: Membrane and Surface Structures of Bdellovibrio bacteriovorus. Adv Microb Physiol 2008; 54:313-61. [DOI: 10.1016/s0065-2911(08)00005-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Thomashow LS, Rittenberg SC. Waveform analysis and structure of flagella and basal complexes from Bdellovibrio bacteriovorus 109J. J Bacteriol 1985; 163:1038-46. [PMID: 4030690 PMCID: PMC219235 DOI: 10.1128/jb.163.3.1038-1046.1985] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The structure of sheathed flagella from Bdellovibrio bacteriovorus was investigated. The first three periods of these flagella were characterized by progressively smaller wavelengths and amplitudes in periods more distal to the cell. The damped appearance was due to a single nonrandom transition between two helical structures within each filament. The intersection of the two helices, one of which was a threefold-reduced miniature of the other, occurred at a fixed distance along the filament and resulted in a shift in the flagellar axis. Flagella increased in length as the cells aged and assumed a constant miniature waveform at their distal ends. The core filament was the principal determinant of flagellar morphology. It was composed of 28,000- and 29,500-dalton polypeptides. The 28,000-dalton subunits were located in the cell-proximal segment of the filament, and the 29,500-dalton subunits were located in the more distal region. The heteromorphous appearance of bdellovibrio flagella arose from the sequential assembly of these subunits. The basal complex associated with core filaments was examined because of its potential involvement in sheath formation. Bdellovibrio basal organelles were generally similar to those of other gram-negative species, but appeared to lack a disk analogous to the outer membrane-associated L ring which is a normal component of gram-negative basal complexes.
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Diedrich DL, Duran CP, Conti SF. Acquisition of Escherichia coli outer membrane proteins by Bdellovibrio sp. strain 109D. J Bacteriol 1984; 159:329-34. [PMID: 6376474 PMCID: PMC215633 DOI: 10.1128/jb.159.1.329-334.1984] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The ability of Bdellovibrio sp. to acquire the OmpF major outer membrane protein from its Escherichia coli prey was examined to determine if there were other outer membrane proteins which could or could not be acquired. Growth of bdellovibrios on mutant prey which were defective in the expression of outer membrane proteins revealed that Bdellovibrio sp. could acquire the OmpC protein in the absence of the OmpF protein. However, the OmpA, LamB, and protein 2 proteins could not be found in the Bdellovibrio Triton-insoluble outer membrane. The disappearance of the OmpF and OmpC proteins from the bdelloplast surface was measured, and it was determined that Bdellovibrio sp. exhibited a kinetic and temporal preference for the OmpF protein. Bdellovibrios could be grown on porin-deficient prey, and the progeny bdellovibrios possessed outer membranes with a protein mass deficiency.
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Ruby EG, Rittenberg SC. Attachment of diaminopimelic acid to bdelloplast peptidoglycan during intraperiplasmic growth of Bdellovibrio bacteriovorus 109J. J Bacteriol 1984; 158:597-602. [PMID: 6202674 PMCID: PMC215470 DOI: 10.1128/jb.158.2.597-602.1984] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
An early event in the predatory lifestyle of Bdellovibrio bacteriovorus 109J is the attachment of diaminopimelic acid (DAP) to the peptidoglycan of its prey. Attachment occurs over the first 60 min of the growth cycle and is mediated by an extracellular activity(s) produced by the bdellovibrio. Some 40,000 DAP residues are incorporated into the Escherichia coli bdelloplast wall, amounting to ca. 2 to 3% of the total initial DAP content of its prey cells. Incorporation of DAP occurs when E. coli, Pseudomonas putida, or Spirillum serpens are the prey organisms. The structurally similar compounds lysine, ornithine, citrulline, and 2,4-diaminobutyric acid are not attached. The attachment process is not affected by heat-killing the prey nor by the addition of inhibitors of either energy generation (cyanide, azide, or arsenate), protein or RNA synthesis (chloramphenicol and rifamycin), or de novo synthesis of cell wall (penicillin or vancomycin). Approximately one-third of the incorporated DAP is exchangeable with exogenously added unlabeled DAP, whereas the remaining incorporated DPA is solubilized only during the lysis of the bdelloplast wall. Examination of DAP incorporation at low prey cell densities suggests that bdellovibrios closely couple the incorporation to an independent, enzymatic solubilization of DAP by a peptidase. The data indicate that DAP incorporation is a novel process, representing the second example of the ability of the bdellovibrio to biosynthetically modify the wall of its prey.
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Cover WH, Martinez RJ, Rittenberg SC. Permeability of the boundary layers of Bdellovibrio bacteriovorus 109J and its bdelloplasts to small hydrophilic molecules. J Bacteriol 1984; 157:385-90. [PMID: 6363383 PMCID: PMC215259 DOI: 10.1128/jb.157.2.385-390.1984] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Measurements of the sucrose-permeable and -impermeable volumes during Bdellovibrio bacteriovorus attack on Escherichia coli or Pseudomonas putida showed that the volume of the bdelloplast increased over that of the substrate cell. Although the pattern of the increase differed with the two organisms, the volumes reached maximum at about 60 min into the bdellovibrio growth cycle. By this time, the cytoplasmic membranes of the attacked cells were completely permeable to sucrose. The kinetics of increase in sucrosepermeable volumes were similar to the kinetics of attachment and penetration (Varon and Shilo, J. Bacteriol. 95:744-753, 1968). These data show that the original cytoplasmic and periplasmic compartmentalization of the substrate cell ceases to exist with respect to small hydrophilic molecules during bdellovibrio attack. In contrast, the effective pore size of the outer membrane of the substrate cell to small oligosaccharides remains unaltered during bdelloplast formation as was shown by direct measurements of its exclusion limits. The major porin protein of E. coli, OmpF, was recoverable from the bdelloplast outer membrane fraction until the onset of lysis. The Braun lipoprotein was removed from the bdelloplast wall early, and OmpA was lost in the terminal part of the bdellovibrio growth cycle.
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Odelson DA, Patterson MA, Hespell RB. Periplasmic enzymes in Bdellovibrio bacteriovorus and Bdellovibrio stolpii. J Bacteriol 1982; 151:756-63. [PMID: 6124531 PMCID: PMC220322 DOI: 10.1128/jb.151.2.756-763.1982] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
When cells of either Bdellovibrio bacteriovorus 109J or Bdellovibrio stolpii UKi2 were subjected to osmotic shock by treatment with sucrose-EDTA and MgCl2 solutions, only trace amounts of proteins or enzyme activities were released into the shock fluid. In contrast, when nongrowing cells were converted to motile, osmotically stable, peptidoglycan-free spheroplasts by penicillin treatment, numerous proteins were released into the suspending fluid. For both species, this suspending fluid contained substantial levels of 5'-nucleotidase, purine phosphorylase, and deoxyribose-phosphate aldolase. Penicillin treatment also released aminoendopeptidase N from B. bacteriovorus, but not from B. stolpii. Penicillin treatment did not cause release of cytoplasmic enzymes such as malate dehydrogenase. The data indicated that bdellovibrios possess periplasmic enzymes or peripheral enzymes associated with the cell wall complex. During intraperiplasmic bdellovibrio growth, periplasmic and cytoplasmic enzymes of the Escherichia coli substrate cell were not released upon formation of the spherical bdelloplast during bdellovibrio penetration. Most of the E. coli enzymes were retained within the bdelloplast until later in the growth cycle, when they became inactivated or released into the suspending buffer or both.
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Betina V. The use of antibiotics for studies of morphogenesis and differentiation in microorganisms. Folia Microbiol (Praha) 1980; 25:505-23. [PMID: 7002750 DOI: 10.1007/bf02897219] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Numerous antibodies with a known mechanism of action are utilized as possible means for studying morphogenesis and differentiation. Inhibitors of biosynthesis of nucleic acids and proteins, compounds intervening with the synthesis and/or function of cell walls and membranes or compounds influencing the energy metabolism are particularly useful. The use of antibiotics for studies of the life cycle of viruses, bacteria, fungi, myxomycetes, protozoa and algae is analyzed in the present communication. Certain aspects of morphogenesis and functions of mitochondria and plastids were clarified with the aid of antibiotics. Relationships between production of antibiotics and differentiation of their producers are discussed in the final part of the paper.
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Thomashow MF, Rittenberg SC. Intraperiplasmic growth of Bdellovibrio bacteriovorus 109J: attachment of long-chain fatty acids to escherichia coli peptidoglycan. J Bacteriol 1978; 135:1015-23. [PMID: 357411 PMCID: PMC222478 DOI: 10.1128/jb.135.3.1015-1023.1978] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
During the initial stages of intraperiplasmic growth of Bdellovibrio bacteriovorus on Escherichia coli, the peptidoglycan of the E. coli becomes acylated with long-chain fatty acids, primarily palmitic acid (60%) and oleic acid (20%). The attachment of the fatty acids to the peptidoglycan involves a carboxylic-ester bond, i.e., they were removed by treatment with alkaline hydroxylamine. Their linkage to the peptidoglycan does not involve a protein molecule. When the bdelloplast peptidoglycan was digested with lysozyme, the fatty acid-containing split products behaved as lipopeptidoglycan, i.e., they were extracted into the organic phase of 1-butanol:acetic acid:water (4:15) two-phase system; all of the lysozyme split products generated from normal E. coli peptidoglycan were extracted into the water phase. It is suggested that the function of the acylation reaction is to help stabilize the bdelloplast outer membrane against osmotic forces. In addition, a model is presented to explain how a bdellovibrio penetrates, stabilizes, and lyses a substrate cell.
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Thomashow MF, Rittenberg SC. Intraperiplasmic growth of Bdellovibrio bacteriovorus 109J: solubilization of Escherichia coli peptidoglycan. J Bacteriol 1978; 135:998-1007. [PMID: 357428 PMCID: PMC222476 DOI: 10.1128/jb.135.3.998-1007.1978] [Citation(s) in RCA: 72] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
During penetration of Bdellovibrio bacteriovorus into Escherchia coli, two enzymatic activities, a glycanase and a peptidase, rapidly solubilized some 10 to 15% of the E. coli peptidoglycan. The glycanase activity, which solubilizes peptidoglycan amino sugars, came to a sharp halt with completion of the penetration process. Peptidase activity, which cleaves diaminopimelic acid residues from the peptidoglycan, continued, but at a decreasing rate. By 90 min after bdellovibrio attack, some 30% of the initial E. coli diaminopimelic acid residues were solubilized and present in the culture fluid as free diaminopimelic acid. During bdellovibrio penetration some 25% of the lipopolysaccharide glucosamine was also solubilized by an as yet undefined enzymatic activity that yielded products having molecular weights below 2,000. The solubilization of E. coli lipopolysaccharide glucosamine also terminated at completion of bdellovibrio penetration. At the end of bdellovibrio growth, a second period of rapid solubilization of bdelloplast peptidoglycan began which resulted in lysis of the bdelloplast and complete solubilization of the peptidoglycan amino sugars and diaminopimelic acid. The final lytic enzyme(s) was synthesized just before the time of lysis.
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