Isolation and Characterization of Lactic Acid Bacteria Producing Bacteriocin from Newborn Infants Feces

Ninety-six strains of bacteria were isolated from newborn infants feces. After Antimicrobial activity was screened, these strains showed a broad inhibition spectrum. Particularly, twenty-one strains had antimicrobial abilities to inhibit Escherichia coli ATCC 35150, Micrococcus luteus CICC 10209, Salmonella typhimurium ZJJK 311. Regarding the physiological analysis of strains and BLAST analysis of 16S rDNA sequences, twenty-one strains were divided into six species: Enterococcus faecium (six isolates), Enterococcus faecalis (six isolates), Enterococcus durans (two isolates), Lactobacillus paracasei (one isolate), Lactobacillus rhamnosus (three isolates), and Lactobacillus plantarum (three isolates). All of the selected strains showed antimicrobial activity against six food-borne pathogens. After treatments with proteinase K or Trypsin, L. paracasei (LZ54), Enterococcus faecalis (LZ95), and L. plantarum (LZ222, LZ227) lost antibacterial activity, indicating that the proteinaceous nature of the antimicrobial compounds were produced by these strains. These strains could be introduced as preservatives in the food industry.