Antifungal activity of lactic acid bacteria against Fusarium oxysporum f. sp. albedinis isolated from diseased date palm in south Algeria

Abstract

In this study, four lactic acid bacteria (Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. lactis biovar. diacetylactis, Leuconostoc mesenteroides subsp. mesenteroides and Leuconostoc mesenteroides subsp. mesenteroides biovar. dextranicum) were screened in vitro for antifungal activity against twelve strains of Fusarium oxysporum f. sp. albedinis (Foa), causal agent of the "Bayoud", the most destructive disease of date palm (Phoenix dactylifera L.) in Algeria. The results of the direct confrontation of LAB against (Foa) on MRS agar and PDA medium showed that there is a better inhibition by the LAB on MRS agar. Lactococcus lactis subsp. lactis biovar. diacetylactis gave the most effective rate inhibition, between 13.51 and 40.29 % on PDA medium and 41.17 and 100% on MRS Agar medium, followed by the other strains with inhibition reached 35.82 % on PDA medium and between 19.29 and 100 % on MRS agar medium. When we used cell-free supernatant, there was appearance of inhibition zones after 24 h incubation, with a percentage of inhibition reached 49.41 %.The microscopic observations in the areas of confrontation of the fungus with the LAB have shown that there is an inhibition of the conidia germination.

Lactic Acid Bacteria as Biocontrol Agents against Potato (Solanum tuberosum L.) Pathogens

“…Significant growth inhibition was, however, obtained in another study for F. oxysporum [43]. Antifungal activity was previously indicated for Leuconostoc mesenteroides against R. solani [42] and F. oxysporum [43]. Our study confirmed these results only for a single strain of L. mesenteroides (out of nine tested).…”

“…Khalaf and Raizada [42] also reported no activity of L. lactis against R. solani. Significant growth inhibition was, however, obtained in another study for F. oxysporum [43]. Antifungal activity was previously indicated for Leuconostoc mesenteroides against R. solani [42] and F. oxysporum [43].…”