Antimicrobial activity of lacticin 3147 against oenological lactic acid bacteria. Combined effect with other antimicrobial agents

Abstract

This study investigated the potential use of lacticin 3147 to control growth of wine lactic acid bacteria (LAB) aiming to develop new approaches for reducing the content of sulphites in wine. Lacticin 3147, potassium metabisulphite and eucalyptus extract interactions were also evaluated. Inhibitory activity of the bacteriocin demonstrated to be strain-dependent and the highest antimicrobial effect was established at the exponential growth phase. Low lacticin 3147 IC50 values (10.46–57.97UA/mL) were measured for most of the strains, except for Lactobacillus casei CIAL-51 which were remarkably resistant (IC50 = 141.70UA/mL); Oenococcus oeni CIAL-117 were the most sensitive strain (IC50 = 10.46UA/mL). A synergistic effect of either lacticin 3147 or eucalyptus extract in combination with metabisulphite in inhibiting LAB growth was measured. Addition of lacticin 3147 to growing cultures of Lactobacillus plantarum CIAL-92 caused effective cell lysis, decrease of cell viability and extensive membrane damage, differing from the effects detected after addition of eucalyptus extract. To our knowledge, this is the first study that reports the inhibitory activity of this bacteriocin against oenological LAB and its potential role in the wine industry. The potential of eucalyptus extract as antimicrobial agent in winemaking is also highlighted. A combination of these two antimicrobials with metabisulphite could represent a promising approach to preserve LAB spoilage in wine and, consequently, eliminate or reduce the addition of SO2.