Characterization of the antagonistic activity of Lactobacillus amylovorus DCE 471 and large scale isolation of its bacteriocin amylovorin L471

Latobacillus amylovorus DCE 471, isolated from corn steep liquor, produces a bacteriocin, called amylovorin L471. The strain displays two different colony morphologies. The protein profiles of both colony types show a very high visual similarity to the type strain of the Lactobacillus acidophilus DNA homology group A3. Amylovorin L471 is identified as a small, thermostable and strongly hydrophobic bacteriocin displaying antagonistic activity towards closely related strains. Production of amylovorin is growth-associated indicating primary metabolite kinetics. It is maximally produced at a controlled pH of 5.0-5.4. Two simple and upscaleable isolation procedures seem to be promising for large-scale isolation of bacteriocins: organic solvent (chloroform/methanol) extraction and precipitation, and expanded bed adsorption.