An adhesion-defective mutant of Ruminococcus albus SY3 is impaired in its capability to degrade cellulose

Miron,; Morag,; Lamed,; Ben-Ghedalia,

doi:10.1046/j.1365-2672.1998.00336.x

Cited by 18 publications

(19 citation statements)

References 6 publications

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“…The putative class III bacteriocins in R. albus AD2013 and R. albus SY3 had identical amino acid sequences. R. albus strain SY3 was isolated from anaerobic cellulose roll tubes (53), and R. albus AD2013 was obtained from the rumen of a New Zealand cow as part of a study to isolate previously uncultured ruminal bacteria (54).…”

Section: Discussionmentioning

confidence: 99%

Distribution and Genetic Diversity of Bacteriocin Gene Clusters in Rumen Microbial Genomes

Azevedo

Bento

Ruiz

et al. 2015

Appl Environ Microbiol

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b Some species of ruminal bacteria are known to produce antimicrobial peptides, but the screening procedures have mostly been based on in vitro assays using standardized methods. Recent sequencing efforts have made available the genome sequences of hundreds of ruminal microorganisms. In this work, we performed genome mining of the complete and partial genome sequences of 224 ruminal bacteria and 5 ruminal archaea to determine the distribution and diversity of bacteriocin gene clusters. A total of 46 bacteriocin gene clusters were identified in 33 strains of ruminal bacteria. Twenty gene clusters were related to lanthipeptide biosynthesis, while 11 gene clusters were associated with sactipeptide production, 7 gene clusters were associated with class II bacteriocin production, and 8 gene clusters were associated with class III bacteriocin production. The frequency of strains whose genomes encode putative antimicrobial peptide precursors was 14.4%. Clusters related to the production of sactipeptides were identified for the first time among ruminal bacteria. BLAST analysis indicated that the majority of the gene clusters (88%) encoding putative lanthipeptides contained all the essential genes required for lanthipeptide biosynthesis. Most strains of Streptococcus (66.6%) harbored complete lanthipeptide gene clusters, in addition to an open reading frame encoding a putative class II bacteriocin. Albusin B-like proteins were found in 100% of the Ruminococcus albus strains screened in this study. The in silico analysis provided evidence of novel biosynthetic gene clusters in bacterial species not previously related to bacteriocin production, suggesting that the rumen microbiota represents an underexplored source of antimicrobial peptides.T he production of low-molecular-weight antimicrobial peptides is a trait widely distributed among species of bacteria and archaea (1). Although a variety of functions has been assigned to these compounds (e.g., toxins, virulence factors, bacterial hormones), the bacteriocins have mainly been investigated due to their potential as alternatives to antibiotics and food preservatives (2-4). With the rise in antibiotic resistance among commensal and pathogenic strains of bacteria, there is an urgent need to identify and develop novel therapeutic strategies for clinical applications in human and animal health (5).Bacteriocins are often defined as ribosomally synthesized antimicrobial peptides produced by bacteria or archaea (6). Bacteriocins show great diversity in their chemical structures and mechanisms of action, and at least four main groups have been proposed to classify these antimicrobial agents (7). Class I contains posttranslationally modified antimicrobial peptides, such as lanthipeptides, sactipeptides, and lasso peptides, which differ in their molecular structures, their mechanisms of action, and the enzymatic apparatuses involved in modifying the precursor peptides (7,8). Class II bacteriocins consist of antimicrobial peptides without posttranslationally modified residues and ca...

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Section: Discussionmentioning

confidence: 99%

Distribution and Genetic Diversity of Bacteriocin Gene Clusters in Rumen Microbial Genomes

Azevedo

Bento

Ruiz

et al. 2015

Appl Environ Microbiol

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“…cocalyx, a fimbria-like structure(s) comprised of the CbpC protein, and cellulosome-like structures may all be involved (23,30,31,34). Western immunoblots showed there were no differences among the wild-type and mutants strains examined with respect to CbpC production, but the adhesion-defective mutants of R. albus strain 20 are known to be defective in production of this protein (34,42).…”

Section: Vol 186 2004 R Albus Mutants Defective In Cellulose Degramentioning

confidence: 99%

Ruminococcus albus 8 Mutants Defective in Cellulose Degradation Are Deficient in Two Processive Endocellulases, Cel48A and Cel9B, Both of Which Possess a Novel Modular Architecture

et al. 2004

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The cellulolytic bacterium Ruminococcus albus 8 adheres tightly to cellulose, but the molecular biology underpinning this process is not well characterized. Subtractive enrichment procedures were used to isolate mutants of R. albus 8 that are defective in adhesion to cellulose. Adhesion of the mutant strains was reduced 50% compared to that observed with the wild-type strain, and cellulose solubilization was also shown to be slower in these mutant strains, suggesting that bacterial adhesion and cellulose solubilization are inextricably linked. Two-dimensional polyacrylamide gel electrophoresis showed that all three mutants studied were impaired in the production of two high-molecular-mass, cell-bound polypeptides when they were cultured with either cellobiose or cellulose. The identities of these proteins were determined by a combination of mass spectrometry methods and genome sequence data for R. albus 8. One of the polypeptides is a family 9 glycoside hydrolase (Cel9B), and the other is a family 48 glycoside hydrolase (Cel48A). Both Cel9B and Cel48A possess a modular architecture, Cel9B possesses features characteristic of the B 2 (or theme D) group of family 9 glycoside hydrolases, and Cel48A is structurally similar to the processive endocellulases CelF and CelS from Clostridium cellulolyticum and Clostridium thermocellum, respectively. Both Cel9B and Cel48A could be recovered by cellulose affinity procedures, but neither Cel9B nor Cel48A contains a dockerin, suggesting that these polypeptides are retained on the bacterial cell surface, and recovery by cellulose affinity procedures did not involve a clostridium-like cellulosome complex. Instead, both proteins possess a single copy of a novel X module with an unknown function at the C terminus. Such X modules are also present in several other R. albus glycoside hydrolases and are phylogentically distinct from the fibronectin III-like and X modules identified so far in other cellulolytic bacteria.

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“…Mosoni and Gaillard-Martinie (33) have reported that an adherence-defective mutant of R. albus 20 displayed slower degradation of cellulose and a longer lag period prior to cellulose degradation, and Miron et al (29) have reported that adherence-defective mutants of R. albus SY3 degraded several types of cellulose more slowly and produced lower titers of cellulase and xylanase than did wild-type cells. However, even among wild-type R. albus isolates, the relationship between adherence and cellulolytic capability varies substantially by strain, leading Miron et al and Morrison and Miron (27,32) to suggest that multiple mechanisms may be involved in adherence.…”

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confidence: 99%

Studies of the Extracellular Glycocalyx of the Anaerobic Cellulolytic Bacterium Ruminococcus albus 7

Weimer

Price

Kroukamp

et al. 2006

Appl Environ Microbiol

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Anaerobic cellulolytic bacteria are thought to adhere to cellulose via several mechanisms, including production of a glycocalyx containing extracellular polymeric substances (EPS). As the compositions and structures of these glycocalyces have not been elucidated, variable-pressure scanning electron microscopy (VP-SEM) and chemical analysis were used to characterize the glycocalyx of the ruminal bacterium Ruminococcus albus strain 7. VP-SEM revealed that growth of this strain was accompanied by the formation of thin cellular extensions that allowed the bacterium to adhere to cellulose, followed by formation of a ramifying network that interconnected individual cells to one another and to the unraveling cellulose microfibrils.

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An adhesion-defective mutant of Ruminococcus albus SY3 is impaired in its capability to degrade cellulose

Cited by 18 publications

References 6 publications

Distribution and Genetic Diversity of Bacteriocin Gene Clusters in Rumen Microbial Genomes

Distribution and Genetic Diversity of Bacteriocin Gene Clusters in Rumen Microbial Genomes

Ruminococcus albus 8 Mutants Defective in Cellulose Degradation Are Deficient in Two Processive Endocellulases, Cel48A and Cel9B, Both of Which Possess a Novel Modular Architecture

Studies of the Extracellular Glycocalyx of the Anaerobic Cellulolytic Bacterium Ruminococcus albus 7

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