10.22376/ijpbs.2019.10.1.p1-12 Volume 5 Issue 3 2014 (July- September) The present study compared the antagonistic activity and probiotic properties of two Lactic Acid Bacteria (LAB) such as lessThan i greaterThan Enterococcus faecium lessThan /i greaterThan NCIM 2605 and lessThan i greaterThan Lactococcus lactis lessThan /i greaterThan NCIM 2606. Bacteriocin from both the cultures was produced using MRS broth by shake flask fermentation. In well diffusion method, the cell free supernatant (CFS) of lessThan i greaterThan E. faecium lessThan /i greaterThan showed activity against both gram positive and gram negative organisms especially methicillin resistant lessThan i greaterThan S, aureus lessThan /i greaterThan (MRSA). Maximum inhibition was observed against lessThan i greaterThan B. subtilis lessThan /i greaterThan and lessThan i greaterThan V. parahaemolyticus. lessThan /i greaterThan The CFS of lessThan i greaterThan L. lactis lessThan /i greaterThan showed activity against only gram-positive organisms, but not against MRSA. Both the isolates produced bacteriocin at maximum quantity during the exponential phase at pH 6 and pH 7 when incubated at 37 lessThan sup greaterThan 0 lessThan /sup greaterThan C. The arbitrary unit for lessThan i greaterThan E. faecium lessThan /i greaterThan and lessThan i greaterThan L. lactis lessThan /i greaterThan found to be 3,200 AU/ml and 800AU/ml, respectively. The antimicrobial substances was retaining the activity after treated upto 121 lessThan sup greaterThan 0 lessThan /sup greaterThan C for 15 minutes, stable at pH values between 2.0 and 5.0 and 2.0 and 9.0 for lessThan i greaterThan E. faecium lessThan /i greaterThan and lessThan i greaterThan L. lactis lessThan /i greaterThan respectively. Both the substances were found to be sensitive to proteinase K. The tested two LAB survived for 3 hours in the presence of 0.3% w/v bile and pH 3 at 37 lessThan sup greaterThan 0 lessThan /sup greaterThan C. The strain lessThan i greaterThan E. faecium lessThan /i greaterThan having a broad spectrum of activity, possess probiotic ability than the lessThan i greaterThan L. lactis lessThan /i greaterThan and can be developed as probiotic diary fermented products. SIVARAJ ANBARASU, MANIKKAM RADHAKRISHNAN, ARUMUGAM SURESH, JERRINE JOSEPH AND VANAJA KUMAR Bacteriocin, LAB, probiotic, Nisin, Enterocin 682-690