Institute of Biochemistry and Biotechnology, University of the Punjab, Lahore, Pakistan.
School of Biological Sciences, University of the Punjab, Lahore, Pakistan.
Microb Pathog. 2019 Jun;131:22-32. doi: 10.1016/j.micpath.2019.03.016. Epub 2019 Mar 19.
Fourteen Lactobacillus plantarum strains isolated from various food sources and two different climatic regions, Ireland and Pakistan were analyzed for their probiotic functions. RecA gene based multiplex PCR amplifications and pulsed-field gel electrophoresis (PFGE) were performed to genetically characterize these strains at subspecies level. All the strains were tested for bacteriocin activity against major food borne pathogens (L. innocua and L. monocytogenes). Bacteriocin was further purified using HPLC and identified with MALDI TOF MS analysis. Identification of gene encoding plantaracin 423 along with its enzyme sensitivity assays to protinease K and pepsin were also performed. Probiotic properties of bacteriocin producing strains were also analyzed by acid tolerance, bile salt tolerance, survival in simulated gastric juice and antibiotic resistance tests. Ten distinctly different strains of PFGE patterns were identified following ApaI digestion. Antimicrobial screening showed five L. plantarum strains as the potential producers of bacteriocin, expressing GIZ (Growth inhibition zone) up to 12, 12, 14, 11 and 13 mm, respectively against L. innocua. Molecular characterization of these strains further exhibited that plantaracin gene was present in the genome of L. plantarum strains AS-4, AS-6, AS-7, AS-13 and AS-14. All strains presented significant in vitro functional probiotic potential. Current study therefore, not only highlights bacteriocin regulated probiotic potential of L. plantarum strains isolated from different sources and climatic regions but also designates high heterogeneity in functional properties of the L. plantarum strains.
从不同的食物来源和两个不同的气候地区(爱尔兰和巴基斯坦)分离出的 14 株植物乳杆菌菌株和两株不同的气候地区(爱尔兰和巴基斯坦)分离出的 14 株植物乳杆菌菌株被分析其益生菌功能。基于 RecA 基因的多重 PCR 扩增和脉冲场凝胶电泳 (PFGE) 用于在亚种下对这些菌株进行遗传特征分析。所有菌株均测试了对主要食源性病原体(L. innocua 和 L. monocytogenes)的细菌素活性。细菌素进一步使用 HPLC 进行纯化,并通过 MALDI TOF MS 分析进行鉴定。还进行了编码 plantaracin 423 的基因鉴定及其对蛋白酶 K 和胃蛋白酶的酶敏感性测定。通过耐酸、耐胆盐、模拟胃液中存活和抗生素耐药性试验分析产细菌素菌株的益生菌特性。经 ApaI 消化后,鉴定出 10 种明显不同的 PFGE 模式菌株。抗菌筛选显示,有 5 株植物乳杆菌菌株具有产生细菌素的潜力,对 L. innocua 的生长抑制区(GIZ)分别达到 12、12、14、11 和 13 mm。这些菌株的分子特征进一步表明,plantaracin 基因存在于植物乳杆菌菌株 AS-4、AS-6、AS-7、AS-13 和 AS-14 的基因组中。所有菌株均表现出显著的体外功能性益生菌潜力。因此,本研究不仅突出了从不同来源和气候地区分离出的植物乳杆菌菌株的细菌素调节益生菌潜力,还设计了植物乳杆菌菌株功能特性的高度异质性。