DETERMINATION OF THE EFFICACY OF LACTOBACILLUS PLANTARUM AND PEDIOCOCCUS PENTOSACEOUS BACTERIA WITH PROBIOTIC PROPERTIES AGAINST FOOD ORIGINATED GRAM-POSITIVE AND GRAM-NEGATIVE PATHOGENS

Abstract

Background: Probiotic bacteria, especially lactic acid bacteria (LAB), are famous for their health benefits. This study examined the inhibitory effects of two LAB strains, Pediococcus pentosaceus and Lactobacillus plantarum, on several food pathogens.

Materials & Methods: This in vitro laboratory study conducted over a 3-month period, examines the inhibitory effects of two LAB strains, P. pentosaceus and L. plantarum, on several food pathogens. Cell-free supernatants (CFS), planktonic cells, and biofilms of the LAB strains were tested against bacteria. The microplate technique and crystal violet staining measured the antibacterial activities of the CFS. The spread plate method was used to evaluate the antagonistic action of planktonic cells and biofilms.

Results: The results showed that a 48-hour incubation was optimal for biofilm production. While the planktonic cells reduced pathogen growth by 0.25-1.17 log CFU/mL for L. plantarum and 0.38-1.56 log CFU/mL for P. pentosaceus. P. pentosaceus biofilm is more effective against B. subtilis and S. Typhimurium, reducing their growth by 1.49 and 1.17 log CFU/mL, respectively. The CFS of P. pentosaceus shown more inhibition of food pathogens than L. plantarum.

Conclusion: L. plantarum exhibited greater biofilm-producing ability compared to P. pentosaceus, and both biofilm and planktonic forms of these two LAB strains effectively inhibited the growth of foodborne pathogenic bacteria.