Integration of Biochar with Atoxigenic Strains of A. flavus Can Effectively Control Aflatoxin Contamination in Groundnuts (Arachis hypogaea L.)

Abstract

In a March 2022 In Vitro study conducted at the NM-AIST Laboratory in Arusha, Tanzania, researchers investigated the efficacy of Biochar in managing aflatoxin contamination in groundnuts, both independently and in combination with Aflasafe. Various concentrations (2 X 10², 2 X 10⁴, 2 X 10⁶, and 2 X 10⁸) of atoxigenic biocontrol strains extracted from AflasafeTZ01 were introduced to the groundnut grains treated with 5%, 10%, 15%, and 20% maize cob Biochar. All groundnuts were then inoculated with atoxigenic A. flavus (2 x 10⁶) and incubated at 30°C for seven days before aflatoxin quantification using HPLC.

The Analysis of Variance (ANOVA) conducted on the data revealed a significant (P < 0.001)  difference among the means in reducing aflatoxins B₁, B₂, G₁, and G₂. Notably, there existed an inverse relationship between the concentration of Biochar and aflatoxin content, with the most substantial reduction observed at a 10% Biochar rate. However, above this rate, there was a slight increase in aflatoxin content.

Moreover, integrating Biochar with the Aflasafe biocontrol option further decreased aflatoxin contamination. For example, the application of 10% Biochar along with 2 x 10⁶ Aflasafe resulted in an impressive 99.99% reduction compared to the control. In comparison, using Biochar or Aflasafe alone led to reductions of 80.6% and 90%, respectively.

These findings hold significant implications for the agricultural sector, suggesting that the strategic utilization of Biochar and Aflasafe can substantially mitigate aflatoxin contamination in groundnuts, thereby bolstering food and nutrition safety standards.