Investigation of probiotic potential of human-derived Lactobacillus plantarum B14

Lactic acid bacteria (LAB) which are major probiotic microorganisms and essential components of the gut microbiota of humans and other mammals, have significant positive impact on the host's health. Therefore, discovering new probiotics with novel probiotic properties would be immensely appreciated by the medical, scientific, and food industries. Despite the fact that probiotic strains can be obtained from a variety of sources, one of the most important criteria for probiotics to be applied for humans is being human originated. The aim of this study is in-vitro characterization of probiotic potential of Lactobacillus Plantarum B14 originated from human gastro intestinal system (GIS). Probiotic features of this strain was examined using several tests, including acid, bile salts and phenol tolerance, antibiotic susceptibility, anti microbial activity, acidification capacity and aggregation ability. Molecular identification by PCR and gene cloning was also used for bacteriocin gene secreening. The results showed L. Plantarum B14 had a high tolerance to varying acid and bile conditions, and high tolerance to different phenol concentration (0.1%, 0.2%, 0.3%, 0.4%), susceptibility to ampicillin, and showed antimicrobial activity against three pathogenic bacteria which are Staphylococcus aureus, Escherichia coli, Listeria monocytogenes RSKK. L. Plantarum B14 was found to be slow acidifier also showed high auto aggregation reaching 100% after 5 h of incubation and high coaggregation ability with all five tested pathogens. In-silico analysis for cloned PCR product showed that bacteriocin coding gene was not detected and further investigation is required to determine bacteriocins coding genes in this strain. The results of these tests indicate that L. Plantarum B14 possess desirable probiotic properties and can be a candidate for further in vivo research aimed in developing a novel probiotic starter cultures.