Abstract

ISOLATION, SCREENING AND IDENTIFICATION OF BACTERIOCIN PRODUCING LAB FROM CURD

*Sarah Sharmila Samuel and Sangeeta Shukla

Abstract

The aim of the investigation was to isolate and identify Lactic acidbacteria (LAB) from curd, and also to study the Inhibitory activity ofthe bacteriocin against selected pathogens. A total of 180 bacterialisolates were randomly selected. Out of these, 130 isolates wereidentified as Lactobacillus spp. (72.22%), others were identified asBacillus spp. 40 (22.22%) and Streptococcus spp. 10 (5.56%). Thescreening of inhibitory activity revealed, only 24 isolates were able togive inhibition zone of 1 mm. Out of these 24 isolates, 5 were selectedfor further study of inhibitory activity of the bacteriocin. Resultsshowed that the highest inhibition was reported in the strain 31 againstB. cereus (21 mm) and S. typhi (22 mm). While 78 revealed highestresults against S. aureus (24 mm) and E. coli, (21 mm). Highestinhibition zone was reported in case of 112 against S. dysenteriae (19.2mm). The other two strains 28 and 143 had revealed least inhibitory zone against the testorganisms. Thus, the isolates of Lactobacillus spp. found effective against the testmicroorganisms can be further studied and their probiotic and antibacterial properties couldbe utilized in therapeutic and food applications.

Keywords: Curd, LAB, Lactobacillus spp., bacteriocin, inhibitory activity.