Detoxification of Aflatoxins in Fermented Cereal Gruel (Ogi) by Probiotic Lactic Acid Bacteria and Yeasts with Differences in Amino Acid Profiles

Abstract

Toxigenic members of Aspergillus flavus contaminate cereal grains, resulting in contamination by aflatoxin, a food safety hazard that causes hepatocellular carcinoma. This study identified probiotic strains as aflatoxin detoxifiers and investigated the changes to the grain amino acid concentrations during fermentation with probiotics in the presence of either A. flavus La 3228 (an aflatoxigenic strain) or A. flavus La 3279 (an atoxigenic strain). Generally, higher concentrations (p < 0.05) of amino acids were detected in the presence of toxigenic A. flavus La 3228 compared to the atoxigenic A. flavus La 3279. Compared to the control, 13/17 amino acids had elevated (p < 0.05) concentrations in the presence of the toxigenic A. flavus compared to the control, whereas in systems with the atoxigenic A. flavus 13/17 amino acids had similar (p > 0.05) concentrations to the control. There were interspecies and intraspecies differences in specific amino acid elevations or reductions among selected LAB and yeasts, respectively. Aflatoxins B1 and B2 were detoxified by Limosilactobacillus fermentum W310 (86% and 75%, respectively), Lactiplantibacillus plantarum M26 (62% and 63%, respectively), Candida tropicalis MY115 (60% and 77%, respectively), and Candida tropicalis YY25, (60% and 31%, respectively). Probiotics were useful detoxifiers; however, the extent of decontamination was species- and strain-dependent. Higher deviations in amino acid concentrations in the presence of toxigenic La 3228 compared to atoxigenic La 3279 suggests that the detoxifiers did not act by decreasing the metabolic activity of the toxigenic strain.

Potential of Animal Excreta as a Source of Probiotic Lactic Acid Bacteria for Aflatoxin B1 Detoxification by the Surface Binding Mechanism

“…In the surface binding mechanism for the removal of AFB 1 , the viability of the LAB was found to play a major role because the majority of heatinactivated LAB cells showed high efficiency in the AFB 1 removal, and it was also reported by Banwo et al 38 According to Haskard et al 22 and Peltonen et al, 39 the surface binding phenomenon of AFs with the cell surface of LAB is the involvement of the non-covalent interactions with the specific functional groups that are exposed from the surface of the gram-positive cell wall. Also, some hydrophobic pockets are also involved in the binding.…”

Involved Microorganisms in the Production of Indigenous Fermented Food from West Africa: Technological Characteristics and Probiotic Power

“…• Probiotic LAB strains as aflatoxin detoxifiers in Ogi: Lactiplantibacillus plantarum M26 and Limosilactobacillus fermentum W310 detoxified aflatoxins B1 and B2 [117].…”