Affiliation:
1. Department of Microbiology1 and
2. Department of Biochemistry,2 University of Stellenbosch, Stellenbosch 7600, South Africa, and
3. Federal Research Centre for Nutrition, Institute of Hygiene and Toxicology, D-76131 Karlsruhe, Germany3
Abstract
ABSTRACT
The pH-neutral cell supernatant of
Enterococcus faecalis
BFE 1071, isolated from the feces of minipigs in Göttingen, inhibited the growth of
Enterococcus
spp. and a few other gram-positive bacteria. Ammonium sulfate precipitation and cation-exchange chromatography of the cell supernatant, followed by mass spectrometry analysis, yielded two bacteriocin-like peptides of similar molecular mass: enterocin 1071A (4.285 kDa) and enterocin 1071B (3.899 kDa). Both peptides are always isolated together. The peptides are heat resistant (100°C, 60 min; 50% of activity remained after 15 min at 121°C), remain active after 30 min of incubation at pH 3 to 12, and are sensitive to treatment with proteolytic enzymes. Curing experiments indicated that the genes encoding enterocins 1071A and 1071B are located on a 50-kbp plasmid (pEF1071). Conjugation of plasmid pEF1071 to
E. faecalis
strains FA2-2 and OGX1 resulted in the expression of two active peptides with sizes identical to those of enterocins 1071A and 1071B. Sequencing of a DNA insert of 9 to 10 kbp revealed two open reading frames,
ent
1071A and
ent
1071B, which coded for 39- and 34-amino-acid peptides, respectively. The deduced amino acid sequence of the mature Ent1071A and Ent1071B peptides showed 64 and 61% homology with the α and β peptides of lactococcin G, respectively. This is the first report of two new antimicrobial peptides representative of a fourth type of
E. faecalis
bacteriocin.
Publisher
American Society for Microbiology
Subject
Ecology,Applied Microbiology and Biotechnology,Food Science,Biotechnology
Cited by
107 articles.
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