Characterization of the Antagonistic Activity of Lactobacillus amylovorus DCE 471 and Large Scale Isolation of Its Bacteriocin Amylovorin L471

Abstract

Summary Lactobacillus amylovorus DCE 471, isolated from corn steep liquor, produces a bacteriocin, called amy-lovorin 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 bac- teriocins: organic solvent (chloroform/methanol) extraction and precipitation, and expanded bed adsorption.