Exploring the Compatibility between Kluyveromyces lactis and Probiotic Lactobacillus spp. and their In-vitro Antimicrobial Potential

Abstract

This study investigated symbiotic interactions between dairy yeast and probiotic Lactobacillus spp., where stable coexistence occurs through the shared utilization of common metabolites and environmental conditions. The primary objective was to evaluate the compatibility between the potential probiotic yeast Kluyveromyces lactis (K lactis) and probiotic Lactobacilli strains, namely Lacticaseibacillus paracasei subsp. paracasei, Lactobacillus acidophilus, Lacticaseibacillus rhamnosus, Lactiplantibacillus plantarum subsp. plantarum, and Lactobacillus helveticus. Additionally, the antibacterial activity was explored. The spot assay on MRS agar confirmed equal growth intensity and the absence of incompatibility between K. lactis and probiotic Lactobacilli spp. Their cultures mutually promoted each other's growth. Most probiotic Lactobacillus strains exhibited significant antibacterial activity against tested pathogens, while K. lactis showed no antibacterial activity. Among six strains of Lactobacillus, L rhamnosus displayed the maximum zone of inhibition (cm) with 3.063 ± 0.071, 2.754 ± 0.133, 2.818 ± 0.125 against B cereus, S aureus and E coli, respectively. The minimum activity was observed in L acidophilus and L bulgaricus with no zone of inhibition against S aureus by both bacteria. The findings of this study on the symbiotic interactions and compatibility of dairy yeast and probiotic Lactobacillus strains, as well as their enhanced growth and significant antibacterial activity, provide important insights for the development of innovative probiotic products with potential health benefits.