Ruminococcin A, a New Lantibiotic Produced by a Ruminococcus gnavu s Strain Isolated from Human Feces

• DOI: 10.1128/aem.67.9.4111-4118.2001
• Publication Date: 2002-07-27T10:00:58Z
• Authors: J. Dabard; C. Bridonneau; C. Phillipe; P. Anglade; D. Molle; M. Nardi; M. Ladiré; H. Girardin; F. Marcille; A. Gomez; M. Fons
• Keywords: [SDV.EE]Life Sciences [q-bio]/Ecology, environment; Clostridium; SUBSTANCE ANTIBACTERIENNE; 0303 health sciences; Bacteria; Molecular Sequence Data; Microbial Sensitivity Tests; Sequence Analysis, DNA; TUBE DIGESTIF; SUBSTANCE ANTIMICROBIENNE; Culture Media; Gram-Positive Cocci; [SDV.EE] Life Sciences [q-bio]/Ecology, environment; Feces; 03 medical and health sciences; Bacteriocins; Humans; Trypsin; Amino Acid Sequence; Anaerobiosis; Sequence Alignment

ABSTRACT

When cultivated in the presence of trypsin, the Ruminococcus gnavus E1 strain, isolated from a human fecal sample, was able to produce an antibacterial substance that accumulated in the supernatant. This substance, called ruminococcin A, was purified to homogeneity by reverse-phase chromatography. It was shown to be a 2,675-Da bacteriocin harboring a lanthionine structure. The utilization of Edman degradation and tandem mass spectrometry techniques, followed by DNA sequencing of part of the structural gene, allowed the identification of 21 amino acid residues. Similarity to other bacteriocins present in sequence libraries strongly suggested that ruminococcin A belonged to class IIA of the lantibiotics. The purified ruminococcin A was active against various pathogenic clostridia and bacteria phylogenetically related to R. gnavus . This is the first report on the characterization of a bacteriocin produced by a strictly anaerobic bacterium from human fecal microbiota.