BACTERICIDAL EFFECT OF PHENOLIC-COMPOUNDS FROM GREEN OLIVES ON LACTOBACILLUS-PLANTARUM

Brines from non-alkali treated green olives were tested for their antimicrobial properties against Lactobacillus plantarum, the lactic acid bacterium involved in Spanish-type brined olive fermentation. They showed a marked bactericidal effect toward 10 L. plantarum strains tested. Aqueous solutions of the total phenolics extracted from these brines had the same bactericidal effect. Transmission electron microscope (TEM) and scanning electron microscope (SEM) preparations showed degradation of cell walls in lactobacilli inoculated in brines or in the total extract of phenolics. Other changes in the cell ultrastructure were observed, such as the presence of mesosomal membranes. Fluorescence microscopy showed adsorption of phenolics to both whole cells and isolated cell walls from L. plantarum. Phenolics in brines were isolated by preparative high-pressure liquid chromatography (HPLC) and identified by gas-liquid chromatography-mass spectrometry (GLC-MS). The degree of antibacterial action toward L. plantarum depended on the phenolic compound. © 1990, Gustav Fischer Verlag, Stuttgart · New York. All rights reserved.