Isolation of enterocin SE-K4-encoding plasmid and a high enterocin SE-K4 producing strain of Enterococcus faecalis K-4.
Enterococcus faecalis K-4, which produces a class IIa bacteriocin, enterocin SE-K4, carries two plasmids, pEK4S (approximately 60 kb) and pEK4L (approximately 75 kb). Plasmid-curing experiments showed that pEK4S was involved in the production of and immunity to enterocin SE-K4 in strain K-4. A derivative strain, M6, with pEK4S produced a higher amount of enterocin SE-K4 than the parental strain K-4, although its growth rate was lower than that of parental strain K-4. Phenotypic changes in strain M6 are attributed to an increase in plasmid copy number.
Doi
Katsumi
K
Laboratory of Applied Microbial Genetics, Faculty of Agriculture, Graduate Schools, Kyushu University, Hakozaki, Fukuoka 812-8581, Japan. doi@agr.kyushu-u.ac.jp
Eguchi
Tomoko
T
Choi
Seong-Hyun
SH
Iwatake
Atsushi
A
Ohmomo
Sadahiro
S
Ogata
Seiya
S