Isolation and characterization of enterocin SE-K4 produced by thermophilic enterococci, Enterococcus faecalis K-4.
Enterococcus sp. K-4, with a bacteriocin-like activity against E. faecium, was isolated from grass silage in Thailand. Morphological, physiological, and phylogenetic studies clearly identified strain K-4 as a strain of E. faecalis. Strain K-4 produced a maximal amount of bacteriocin at 43-45 degrees C. We purified, for the first time, the bacteriocin produced at high temperature by E. faecalis to homogeneity, using adsorption on cells of the producer strain and reversed-phase liquid chromatography. The bacteriocin, designated enterocin SE-K4, is a peptide of about 5 kDa as measured by SDS-PAGE, and Mass spectrometry analysis found the molecular mass of 5356.2, which is in good agreement. The amino acid sequencing of the N-terminal end of enterocin SE-K4 showed apparent sequence similarity to class IIa bacteriocins. Enterocin SE-K4 was active against E. faecium, E. faecalis, Bacillus subtilis, Clostridium beijerinckii, and Listeria monocytogenes. Enterocin SE-K4 is very heat stable.
Eguchi
T
T
National Food Research Institute, Tsukuba, Ibaraki, Japan.
Kaminaka
K
K
Shima
J
J
Kawamoto
S
S
Mori
K
K
Choi
S H
SH
Doi
K
K
Ohmomo
S
S
Ogata
S
S
D000595:Amino Acid Sequence; D001419:Bacteria / Q000187:drug effects; D001430:Bacteriocins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000494:pharmacology; D004355:Drug Stability; D013293:Enterococcus faecalis / Q000737:chemistry* / Q000145:classification / Q000235:genetics; D006358:Hot Temperature; D008969:Molecular Sequence Data; D008970:Molecular Weight; D017386:Sequence Homology, Amino Acid
D001430:Bacteriocins; C432922:enterocin SE-K4