Equipe de Biotechnologie, Energie et Environnement, Ecole Supérieure de Technologie, Université Ibn Zohr, Agadir, Morocco.
Can J Microbiol. 2012 May;58(5):596-604. doi: 10.1139/w2012-027. Epub 2012 Apr 3.
The F420 strain, isolated from raw goat milk and identified as Enterococcus hirae, was selected because of its strong activity against gram-positive bacteria, including Listeria monocytogenes. Interestingly, the F420 strain lacks the virulence genes and decarboxylase activity of histidine, lysine, and ornithine, and it is susceptible to 11 of 14 tested antibiotics, including vancomycin. The antimicrobial compounds produced by E. hirae F420 strain showed high resistance to heat treatment and to acidic and basic pHs. The MALDI-TOF mass spectrometry analysis coupled with the sequence of peptide and structural gene analysis of one of the purified enterocins showed 100% identity with enterocin P (EntP), previously described in E. faecium strains. The structural gene for EntP is located on a plasmid of 65 kb. Other enterocins with molecular mass higher than 7 kDa were also detected. This is the first report of the production of EntP by E. hirae species naturally occurring in foods. The biotechnological characteristics of the F420 strain and its enterocins indicate their potential for application in the control of L. monocytogenes and other undesirable bacteria in food systems.
从生羊奶中分离出的、被鉴定为海氏肠球菌的 F420 菌株，因其对革兰氏阳性菌（包括单核细胞增生李斯特菌）具有很强的活性而被选中。有趣的是，F420 菌株缺乏组氨酸、赖氨酸和鸟氨酸的毒力基因和脱羧酶活性，且对 14 种测试抗生素中的 11 种敏感，包括万古霉素。海氏肠球菌 F420 菌株产生的抗菌化合物对热处理、酸性和碱性 pH 值具有很高的抗性。MALDI-TOF 质谱分析结合一种纯化肠球菌素的肽和结构基因分析表明，其与先前在屎肠球菌菌株中描述的肠球菌素 P（EntP）具有 100%的同一性。EntP 的结构基因位于一个 65kb 的质粒上。还检测到其他分子量高于 7 kDa 的肠球菌素。这是首次报道海氏肠球菌自然存在于食品中产生 EntP。F420 菌株及其肠球菌素的生物技术特性表明它们具有在食品系统中控制单核细胞增生李斯特菌和其他不良细菌的潜力。
