Antifungal Properties of Lactic Acid Bacteria Isolated from Pentaclethra macrophylla, Ricinus communis and Zea mays

Abstract

Locally fermented foods can harbour lactic acid bacteria (LAB) with antimicrobial activity that may be useful in food biopreservation. This study investigated the antifungal activity of LAB isolated from Pentaclethra macrophylla, Ricinus communis and Zea mays against selected fungal contaminants. LAB isolates were cultured and characterised using standard microbiological procedures, while fungal isolates were obtained from contaminated plant materials and identified by their macroscopic and cultural characteristics. Antifungal activity was assessed under in vitro agar conditions, and inhibition zones were recorded. The susceptibility pattern differed among the fungal isolates and LAB tested. Aspergillus fumigatus was inhibited by several LAB isolates, with inhibition-zone diameters ranging from 10 to 17 mm among the responding isolates; recorded values included 10 mm for Lactococcus lactis, 15 mm for Streptococcus sp., and 17 mm for Lactobacillus sp. Lactobacillus sp. also inhibited Aspergillus flavus, while Lactococcus lactis inhibited Rhizopus sp. Aspergillus niger was inhibited by Lactococcus lactis and Lactobacillus salivarius. Pediococcus sp. produced no measurable inhibition against the tested fungi under the assay conditions. Overall, the findings demonstrate differential in vitro antifungal activity among the LAB–fungus combinations. Selected isolates may therefore have potential as natural food-grade biopreservative candidates, although their effectiveness requires confirmation in relevant food matrices under appropriate processing and storage conditions before practical application.