ANTIFUNGAL ACTIVITY OF METABOLITES OF LACTIC ACID BACTERIA AGAINST OCHRATOXIN PRODUCING PENICILLIUM VERRUCOSUM ISOLATED FROM SOYBEANS

Abstract

Penicillium verrucosum is an ochratoxin-producing and common spoilage mould of oilseeds like soya beans.  The interest and attention to Lactic acid Bacteria such as Lactobacillus species in the biological protection of foodstuffs have grown because they generate antimicrobial compounds. This study aimed to determine the effects of metabolites of Lactobacillus plantarum isolates on P.  verrucosum. P. verrucosum previously isolated from soybeans was obtained from the Microbial culture bank of the Nigerian Stored Products Research Institute. Lactobacillus species were isolated from locust beans. Similarity searches with sequences in the ribosomal data project database revealed 95.90% identity with L. plantarum NRIC 0383 and 83.40% with L. plantarum NCU116. The antifungal efficacy of NCFS of L plantarum NRIC 0383 and L. plantarum NCU116, at different concentrations, was determined using standard protocols. L. plantarum NRIC 0383 showed maximum inhibitory activity of 26.00 ± 1.15 mm, 20.10 ± 0.84 mm and 26.00 ± .68 at concentrations of 50, 75, and 100 µl/ml. In the same vein, the inhibitory activities of L. plantarum NCU116 on the growth of P. verrucosum was 18.30 ± 0.68mm, 14.20 ± 1.33mmm, and 21.30 ± 0.03 mm respectively at 50, 75, 100 µl/ml concentration per volume. From the study, the NCFS of L. plantarum NCU116 and L. plantarum NRIC 0383 had good antifungal activity against the test moulds P. verrucosum. The ability of Lactobacillus species to produce compound antagonists to pathogens existing in the food products can be a helpful and effective step in ensuring the safety of food produce and products.