Isolation and identification of Lacticaseibacillus rhamnosus YT and the antibacterial characteristics of its cell free supernatant and cells

Abstract

Lactic acid bacteria (LAB) which produce diverse imperative antimicrobial metabolites have an immense number of applications in food industry. Here, human-derived strain YT was isolated due to its cell free supernatant (CFS-YT) and cells (Cs-YT) respectively performed obvious inhibitory ring to Gram positive and negative spoilage bacteria. Strain YT was identified as Lacticaseibacillus rhamnosus YT by 16s rDNA sequence and morphology. The antibacterial activity of CFS-YT was demonstrated to be growth-dependent, pH sensitive, broad thermostable and proteases insensitive. Cs-YT displayed a broad antibacterial spectrum with the action mode of bacteriostatic. The antibacterial activity of Cs-YT was due to substances located at the cell surface which was sensitive to heat, stable at broad pH gradients and sensitive to specific proteases. These data suggested that L. rhamnosus YT could be used as alternative antimicrobial agents against foodborne spoilage bacteria in food industry.

Next-Generation Probiotics as Novel Therapeutics for Improving Human Health: Current Trends and Future Perspectives

“…It has also been shown to have a positive effect on the immune system, enhancing the production of cytokines and increasing the activity of white blood cells [ 155 ]. Additionally, L. rhamnosus has been shown to enhance the immune response against bacterial infections and to have a protective effect against infections caused by E. coli and Salmonella [ 156 , 157 , 158 ]. The L. acidophilus strain has had a positive impact on the gut microbiome, reducing the growth of pathogenic bacteria and promoting the growth of beneficial bacteria.…”