Salzano G, Villani F, Pepe O, Sorrentino E, Moschetti G, Coppola S
Istituto di Microbiologia Agraria e Stazione di Microbiologia Industriale, Universitè degli Studi di Napoli Federico II, Portici, Italy.
FEMS Microbiol Lett. 1992 Nov 15;78(1):1-6. doi: 10.1016/0378-1097(92)90279-w.
Enterococcus faecalis 226 NWC, isolated from natural whey cultures utilized as starter in water-buffalo Mozzarella cheese manufacture, produces a bacteriocin, designated Enterocin 226 NWC, which is inhibitory to Listeria monocytogenes. Plasmid analysis of E. faecalis 226 NWC showed a single 5.2-kb plasmid, pEF226. In conjugation experiments, pEF226 was transferred into a plasmid-free strain of E. faecalis JH2-2. The transfer required direct cell-to-cell contact and was not inhibited by DNase. The identity of conjugation was confirmed by digestion with SmaI restriction endonuclease and subsequent pulsed-field gel electrophoresis (PFGE) of the genomic DNA of E. faecalis 226, E. faecalis JH2-2 and of the isolates after the mating. The data indicate that the ability of E. faecalis 226 NWC to produce the bacteriocin is linked to the 5.2-kb conjugative plasmid pEF226.
从用作水牛奶酪制作发酵剂的天然乳清培养物中分离出的粪肠球菌226 NWC，可产生一种名为肠球菌素226 NWC的细菌素，它对单核细胞增生李斯特菌具有抑制作用。对粪肠球菌226 NWC进行质粒分析，结果显示有一个5.2 kb的单一质粒，即pEF226。在接合实验中，pEF226被转入无质粒的粪肠球菌JH2-2菌株。这种转移需要细胞与细胞直接接触，且不受DNA酶抑制。通过用SmaI限制性内切酶消化以及随后对粪肠球菌226、粪肠球菌JH2-2以及交配后分离株的基因组DNA进行脉冲场凝胶电泳（PFGE），证实了接合现象。数据表明，粪肠球菌226 NWC产生细菌素的能力与5.2 kb的接合性质粒pEF226有关。
