A5059537731- Probiotics and Fermented Foods
- Bacterial Genetics and Biotechnology
- Gut microbiota and health
- Microbial Metabolites in Food Biotechnology
- Genomics and Phylogenetic Studies
- Microbial Fuel Cells and Bioremediation
- Evolution and Genetic Dynamics
- Microbial Community Ecology and Physiology
- RNA and protein synthesis mechanisms
- Legume Nitrogen Fixing Symbiosis
- Chromium effects and bioremediation
- Bacteriophages and microbial interactions
- Clostridium difficile and Clostridium perfringens research
- Vibrio bacteria research studies
- Diet, Metabolism, and Disease
- Digestive system and related health
- Pancreatic function and diabetes
- Glycosylation and Glycoproteins Research
- Enzyme Production and Characterization
- Antimicrobial Peptides and Activities
- Microbial Natural Products and Biosynthesis
- Enzyme Structure and Function
- CRISPR and Genetic Engineering
- Biochemical and Structural Characterization
- Microbial Metabolic Engineering and Bioproduction
Aix-Marseille Université
2014-2024
Centre National de la Recherche Scientifique
2014-2024
Bioénergétique et Ingénierie des Protéines
2016-2023
Institut de Microbiologie de la Méditerranée
2013-2020
Hospital Universitari i Politècnic La Fe
2019
Laboratoire de Chimie Bactérienne
1986-2014
Institut des Sciences Moléculaires de Marseille
2011
Institut de Neurobiologie de la Méditerranée
2002
Institut National de la Recherche Agronomique
1997-2002
Département Génétique Animale
1997-2001
We have shown that bacterial mutation rates change during the experimental colonization of mouse gut. A high rate was initially beneficial because it allowed faster adaptation, but this benefit disappeared once adaptation achieved. Mutator bacteria accumulated mutations that, although neutral in gut, are often deleterious secondary environments. Consistently, competitiveness mutator is reduced transmission to and re-colonization similar hosts. The short-term advantages long-term...
Commensal bacteria often have an especially rich source of glycan-degrading enzymes which allow them to utilize undigested carbohydrates from the food or host. The species Ruminococcus gnavus is present in digestive tract ≥90% humans and has been implicated gut-related diseases such as inflammatory bowel (IBD). Here we analysed ability two R. human strains, E1 ATCC 29149, host glycans. We showed that although both strains could assimilate mucin monosaccharides, only 29149 was able grow on a...
A human-bacterium symbiosis leads to the production of an antipathogenic and safe RiPP with a novel thioether network.
ABSTRACT When cultivated in the presence of trypsin, Ruminococcus gnavus E1 strain, isolated from a human fecal sample, was able to produce an antibacterial substance that accumulated supernatant. This substance, called ruminococcin A, purified homogeneity by reverse-phase chromatography. It shown be 2,675-Da bacteriocin harboring lanthionine structure. The utilization Edman degradation and tandem mass spectrometry techniques, followed DNA sequencing part structural gene, allowed...
The M6 protein from Streptococcus pyogenes is the best-characterized member of a family cell envelope-associated proteins. Based on observation that C-terminal sorting signals these proteins can drive wall anchoring heterologous unanchored proteins, we have cloned and expressed emm6 structural gene for in various lactic acid bacteria (LAB). was successfully lactococcal promoters several Lactococcus lactis strains, an animal-colonizing Lactobacillus fermentum strain, sake, salivarius subsp....
The molecular cross-talk between commensal bacteria and the gut play an important role in maintenance of intestinal homeostasis general health. Here, we studied impact a major Gram-positive anaerobic bacterium human microbiota, that is, Ruminococcus gnavus on glycosylation pattern production mucus by goblet cells.Our results showed R. E1 specifically increases expression level glyco-conjugates cells colonic mucosa mono-associated mice with as well HT29-MTX cells. Such effect was mediated...
ABSTRACT We show in a gnotobiotic mouse model that, addition to direct selection of antibiotic-resistant bacteria, some antibiotic treatments also select for mutator alleles. Because these alleles' high mutation rates, the initial treatment failure increases probability failures subsequent with other drugs.
ABSTRACT Ruminococcus gnavus belongs to the 57 most common species present in 90% of individuals. Previously, we identified an α-galactosidase (Aga1) belonging glycoside hydrolase (GH) family 36 from R. E1 (M. Aguilera, H. Rakotoarivonina, A. Brutus, T. Giardina, G. Simon, and M. Fons, Res. Microbiol. 163:14–21, 2012). Here, a novel GH36-encoding gene same strain termed it aga2 . Although aga1 showed very simple genetic organization, is part operon unique structure, including genes...
The chromate efflux pump encoding gene chrASO was identified on the chromosome of Shewanella oneidensis MR1. Although is expressed without chromate, its expression level increases when Cr(VI) added. When deleted, resulting mutant ΔchrASO exhibits a sensitive phenotype compared to that wild-type strain. Interestingly, heterologous in E. coli confers resistance high concentration. Moreover, S. and significantly improves reduction. This effect could result either from extracytoplasmic reduction...
Soft-rotting Erwinia spp. export degradative enzymes to the cell exterior (Out+), a process contributing their ability macerate plant tissues. Transposon (Tn5, Tn10, Tn10-lacZ) insertion Out- mutants were obtained in carotovora subsp. 71 by using plasmid and bacteriophage lambda delivery systems. In these mutants, pectate lyases, polygalacturonase, cellulase, which are normally excreted into growth medium, accumulated periplasm. However, localization of extracellular protease was not...
The emergence of superbugs developing resistance to antibiotics and the resurgence microbial infections have led scientists start an antimicrobial arms race. In this context, we previously identified active RiPP, Ruminococcin C1, naturally produced by Ruminococcus gnavus E1, a symbiont healthy human intestinal microbiota. This subclassified as sactipeptide, requires host digestive system become against pathogenic Clostridia multidrug-resistant strains. Here report its unique compact...
ABSTRACT Ruminococcin A (RumA) is a trypsin-dependent lantibiotic produced by Ruminococcus gnavus E1, gram-positive strict anaerobic strain isolated from human intestinal microbiota. 12.8-kb region R. E1 chromosome, containing the biosynthetic gene cluster of RumA, has been cloned and sequenced. It consisted 13 open reading frames, organized in three operons with predicted functions biosynthesis, signal transduction regulation, immunity. One unusual feature locus presence almost identical...
Ruminococcin A (RumA) is a lanthipeptide with high activity against pathogenic clostridia and naturally produced by the strict anaerobic bacterium Ruminococcus gnavus E1, isolated from human intestine. Cultivating R. E1 challenging, limiting high-quality production, further biotechnological development therapeutic exploitation of RumA. To supply an alternative production system, gene encoding RumA-modifying enzyme (RumM) unmodified precursor peptide (preRumA) were amplified chromosome...
ABSTRACT Fourteen bacterial strains capable of producing a trypsin-dependent antimicrobial substance active against Clostridium perfringens were isolated from human fecal samples various origins (from healthy adults and children, as well with chronic pouchitis). Identification these showed that they belonged to Ruminococcus gnavus , nexile hansenii species or new operational taxonomic units, all the coccoides phylogenetic group. In hybridization experiments probe specific for structural gene...
Fusions between fnr, the regulatory gene for anaerobic electron transfer, and lacZ were obtained by insertion of MudII1734 bacteriophage in fnr cloned a plasmid. After transfer onto chromosome, study fusion showed that expression is independent anaerobiosis, negatively regulated its own product partly positively controlled cyclic AMP.
Ruminococcin C (RumC) is a trypsin-dependent bacteriocin produced by R uminococcus gnavus E1, gram-positive strict anaerobic strain isolated from human feces. It consists of at least three similar peptides active against lostridium perfringens. In this article, 15-kb region R. E1 chromosome, containing the biosynthetic gene cluster RumC was characterized. harbored 17 open reading frames (called genes) with predicted functions in biosynthesis and post-translational modification, signal...