ABSTRACT
Lactic acid bacteria were isolated from dairy food. They were identified on the basis of their morphological, cultural and biochemical characterastics.The cell free supernatant of lactic acid bacteria were able to inhibit the growth of E.coli, Klebsiella aerogens, Salmonella spp. , S.aureus, P.mirabilies and Ps .aeruginosa. The probiotic properties of isolate of lactic acid bacteria (LAB-VI) were investigated. The LAB-VI was susceptible to antibiotics like ampicillin, gentamycin, ciprofloxacin, ofloxacin and streptomycin. Maximum biomass of LAB – VI was obtained at pH: 5, inoculum size 4% v/v & incubation period 48 hrs. Efficacy of coconut extract medium (Type I and Type II) on growth, lactic acid and hydrogen peroxide production by LABVI was studied using laboratory bioreactor in batch fermentation. The type II coconut extract medium gave higher biomass yield than type I (coconut extract medium). The biomass production from MRS was more than coconut extract medium. The formulated coconut extract medium (Type II) should be used to substitute MRS, since the substrate is economical, readily available and reduce quantity of the expensive supplements. The bacteriocin activity of the bacteriocin from fermented Type I & Type II coconut extract media were 1:6 & 1:8 respectively. The bacteriocin activity was tested against Klebsiella aerogens.