Lactic acid bacteria (Leuconostoc mesenteroides) as bioprotective agents against some pathogenic fungi in common bean

Abstract

Abstract The common bean (Phaseolus vulgaris L.) is the most important edible food legume in the world. However, its cultivation encounters several phytopathogens. Our study aims to improve food quality and safety through more natural protection methods such as the use of microorganisms that allows us to avoid and minimize pesticide risks. For this purpose, we tested the antagonistic capacity of lactic acid bacteria isolated from raw goat’s milk against four fungal strains isolated from P. vulgaris var. djedida. In this study, lactic acid bacteria (LAB) (Leuconostoc mesenteroides) were screened in vitro for antifungal activity at 28 °C against Fusarium oxysporum, Botrytis cinerea, Aspergillus flavus, and Alternaria alternata. The statistical analysis of the antifungal activity of LAB showed significant differences after a seven-day period. The results of the direct confrontation on the PDA (Potato Dextrose Agar) and MRS (de Man, Rogosa, and Sharpe) Agar medium showed better inhibition by the lactic acid strain on MRS Agar medium. L. mesenteroides gave the highest inhibition rate of 57.6% for the pathogen B. cinerea and 29.1%, 33.3%, and 26.7%, respectively, for the pathogens A. alternata, B. cinerea, F. oxysporum, and A. flavus on the solid PDA medium. However, on the MRS Agar medium, inhibition rates of 88.1% and 80.5% were observed for the pathogens B. cinerea and A. flavus and a total inhibition of 100% on A. alternata and F. oxysporum in the presence of the strain L. mesenteroides. This study led to suggest that food-derived LAB strains could be selected for biotechnological application to control phytopathogenic fungi.