Antifungal effectiveness of metabolites produced by lactic acid bacteria.

TORRES M.J., GEREZ C.L., TORRES LEAL G., FONT DE VALDEZ G Y ROLLÁN G.

BIOCELL

Año: 2008 vol. 32 p. 42 - 42

0327-9545

The antifungal activity of lactic acid bacteria (LAB) was demonstrated in previous studies. The aim of this work was to identify the biofungicide compounds (BF)  and to evaluate their effectiveness respect to the chemical additives (CQ) used in the industry for conservation purposes. The BF were identified in the LAB cultures by HPLC method. The capacity of the BF to inhibit the conidia germination was evaluated. The BF are acidic in nature, and related to lactic, acetic, and phenyl lactic acid (PLA). The antifungal activity was directly proportional to the acid concentration and depended on the fungi species. Lactic acid was the least and PLA the most effective BF identified. The effectiveness of the BF was determined by comparing its lethal dose 80 (LD) respect to different CQ. Sorbate, a CQ frequently used in the food industry, showed lower effectiveness (LD:35mM) than PLA (LD:21mM). The inhibitory effect of CQ was directly correlated to its concentration, except for the imazalyl activity that decreased at greater concentrations. The use of BAL and/or the BF as "Bio-conservative" is an alternative to reduce the use of CQ in the agro industry.