Ruminococcin A, a new lantibiotic produced by a Ruminococcus gnavus strain isolated from human feces.
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.
Dabard
J
J
Unité d'Ecologie et de Physiologie du Système Digestif, Institut National de la Recherche Agronomique, 78352 Jouy-en-Josas Cedex, France.
Bridonneau
C
C
Phillipe
C
C
Anglade
P
P
Molle
D
D
Nardi
M
M
Ladiré
M
M
Girardin
H
H
Marcille
F
F
Gomez
A
A
Fons
M
M
D000595:Amino Acid Sequence; D000693:Anaerobiosis; D001419:Bacteria / Q000187:drug effects; D001430:Bacteriocins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000494:pharmacology*; D003013:Clostridium / Q000187:drug effects; D003470:Culture Media; D005243:Feces / Q000382:microbiology*; D006095:Gram-Positive Cocci / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D006801:Humans; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014357:Trypsin / Q000378:metabolism
D001430:Bacteriocins; D003470:Culture Media; C439291:ruminococcin A; D014357:Trypsin