Pediococcus spp. A potential probiotic isolated from Khadi (an Indian fermented food) and identified by 16S rDNA sequence analysis

Abstract

The probiotic potential of the lactic acid bacteria (LAB) isolated from fermentedKhadi was investigated. The pure culture of the isolate GS4, was subjected to microbiological, biochemical characterization and 16S rDNA gene sequence analysis for species confirmation. Among other probiotic properties, GS4 exhibited antibacterial ability against Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922) and Pseudomonas aeruginosa (ATCC 25619), with an average zone of inhibition of 25.03 ± 2.13 mm, 18.83 ± 0.98 mm and 17.33 ± 0.58 mm respectively. The GS4 showed also significant bile  tolerance and survivability at pH 3.5. Amplification of DNA was carried out by the consensus 16S rDNA primers. Sequencing was performed with the aid of big dye terminator version 3.1 cycle sequencing kit. The data was analysed using software seq scape version 5.2 and was compared by alignment against the 16S rDNA sequences of LAB. Phylogenetic tree was created based on Jukes- cantor corrected distance model and the tree was created using weighbor. The statistical tool used for estimating sample distribution by resampling with replacement from original sample was carried out using Bootstrap method. The sequence of the isolate has been deposited in Genbank repository holding an NCBI accession number HM044322. The sequence reveals the LAB isolate as Pediococcus sp. GS4, a closest homologue to Pediococcus sp. Pom 4 (EF107608) with a similarity score of 0.997. The work looks forward the future use of this probiotic strain in food biotechnology.   Key words: Pediococcus sp. GS4, probiotics, 16S rDNA, antibacterial, survivability.