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 pH conditions, and showed a relatively narrow spectrum of activity with notable activity 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.