In Vitro Efficacy of Selected LAB Strains against Aflatoxigenic Fungi

Abstract

Aflatoxins are secondary metabolites produced by various species of Aspergillus and are responsible for toxic effects on farm animals. The limitation of the mycotoxin contamination of food and feed could be achieved by specific methods that inhibit the fungal growth. The aim of our work was the evaluation the effects of different lactic acid bacteria strains (as potential biocontrol agents) on Aspergillus flavus growth and aflatoxin biosynthesis. Two toxigenic isolates of A. flavus were selected as high aflatoxin producers, based on in vitro observations (fluorescence on coconut medium, after exposure to UV light, and large opaque ring surrounding the fungal colonies cultivated on PDA medium with β-cyclodextrine and sodium deoxycholate). As inhibitory microorganisms were used strains of lactic acid bacteria. Significant morphological effects of lactic acid bacteria on A. flavus mycelium were observed microscopically. For separation of aflatoxins from samples, was used thin-layer chromatography (TLC). Lactobacilus plantarum 58, 35, 45 had inhibitory effects both on fungal growth and aflatoxin level.

Keywords

• aspergillus flavus
• aflatotoxins
• antagonistic
• lactic acid bacteria
• tlc