Extraction and characterization of bioactive secondary metabolites from lactic acid bacteria and evaluating their antifungal and antiaflatoxigenic activity.

Aflatoxins are toxic carcinogens and mutagens formed by some moulds, specifically spp. Therefore, this study aimed to extract and identify bioactive secondary metabolites from species, to evaluate their efficacy in reducing fungal growth and aflatoxin production and to investigate their toxicity. The bioactive secondary metabolites of species showed variable degrees of antifungal activity, whereas ethyl acetate extract No. 5 exhibited the highest antifungal activity and, thus, was selected for further identification studies. Data revealed that ethyl acetate extract No. 5 produced various organic acids, volatile organic compounds and polyphenols, displayed antifungal activity against , and triggered morphological changes in fungal conidiophores and conidiospores. ethyl acetate extract No. 5 at a 9 mg/mL concentration reduced AFB production by 99.98%. When the effect of ethyl acetate extract No. 5 on brine shrimp mortality was studied, the extract attained a 100% mortality at a concentration of 400 µg/mL, with an IC of 230 µg/mL. Meanwhile, a mouse bioassay was performed to assess the toxicity of ethyl acetate extract No. 5, whereas there were no harmful effects or symptoms in mice injected with ethyl acetate extract at concentrations of 1, 3, 5, 7, and 9 mg/kg body weight.