Production of brevicin 286 by Lactobacillus brevis VB286 and partial characterization

Brevicin 286 was produced by Lactobacillus brevis VB286 isolated from vacuum-packaged meat and was partially purified by ammonium sulphate precipitation, gel filtration and dialysis. The bacteriocin was susceptible to proteolytic enzymes, stable to heating at 100 degrees C particularly under acidic against Listeria sp. Production of brevicin 286 was optimal during exponential growth at 20 degrees C. Higher rates of cell growth occurred between 30 and 37 degrees C but with little or no expression of brevicin 286. A food-grade formulation consisting of 4% yeast extract and 1% glucose was found to be adequate for optimal brevicin 286 production and the bacteriocin-containing culture supernate was successfully spray dried with full recovery of antibacterial activity in the resultant powder.