Lactobacillus plantarum A7, a potential probiotic strain from infant fecal Flora

Abstract

Lactobacillus plantarum A7 was previously considered in some in vivo studies as a beneficial microorganism. This study deals with characterization of this strain based on general in vitro tests and its clear identification through molecular technique. A subtractive screening process was carried out on 26 lactobacillus strains. Based on tolerance to acid and bile and antibacterial activity against some pathogens, L. plantarum A7 ranked as one of the designated strains and further examined by some tests for probiotic properties like cell surface hydrophobicity, exopolysaccharide (EPS) production and adhesion to glass slides. In addition, antibiotic resistance and hemolytic activity were assessed for safety aspects. Molecular identification of this strain was performed by polymerase chain reaction (PCR), using primers 16 and 23-10c for genus level and planF and pREV for species. L. A7 revealed tolerance to acidic and bile containing environment against tested pathogen. Regarding the cell surface properties, this strain was compatible to commercial probiotic strains posing 53.6a±4 and 72.07 ± 8.79 cell surface hydrophobicity towards toluene and adhesion to glass slid, respectively. This strain meets natural lactobacilli resistance to Vancomycin and lacks transferable resistant to Erythromycin and Cloramphenicol. In order to sequencing the PCR product, it was deposited in the GenBank database as L. plantarum KC355240. The results of this study could be considered as an accomplishing information to what was documented before on this strain with regard to its probiotic potential and it could be recommended to researchers, national and international organizations with high margin of safety. © 2017 Golnoush Madani et al.