Study of probiotics strains isolated from fermented foods on UV induced keratinocytes

Abstract

In this study, conventional culture method and 16s r-RNA gene analysis were applied to reveal the composition and diversity of bacteria from fermented food like curd, yakult, rice and bread. For identification of bacteria, bacterial genomic DNA was isolated, which comprises lysis, followed by incubation with a nonspecific protease and a series of extraction before precipitation of the nucleic acids. The sequencing of 16S r-RNA gene indicates that the isolated bacteria belong to genus Lactobacillus, Acinetobacter, Staphylococcus and Klebsiella. Among these isolated bacteria Lactobacillus casei and Streptococcus thermophilus were explored for their potential as probiotics. The extracts of these bacteria showed inhibition of growth of E. coli and S. aureus found out through micro broth dilution assay. When human keratinocyte cell line was treated with UVB (50 mJ) and the extracts of L. casei and S. thermophilus, cells seem to get repaired or condemn the effect of UVB. Cells were seen to grow in a better condition than those treated with only UVB. Thus, this study provides a potential of probiotic bacteria to reduce some of the regular environmental assaults which our body goes through daily like UV radiation. Further studies needs to be carried out in order to explain the mechanism with which the keratinocytes are growing in the presence of bacterial extracts.