Microbial detoxification of aflatoxins in poultry feeds: effects on nutrient stability and Detoxification capacity of freeze-dried Bacillus spp. (B285) and Saccharomyces spp. (Y833)

Abstract

Microbial detoxification using Bacillus spp. (B285) and Saccharomyces spp. (Y833) offers a promising alternative to the use of chemical methods to degrade aflatoxins while preserving essential nutrients. This study evaluated the detoxification efficiency of Bacillus spp. (B285) and Saccharomyces spp. (Y833) in aflatoxin-contaminated poultry feeds, their effect on nutrient stability, and their detoxification capacity when freeze-dried. Five broiler starter feeds (four commercial and one lab-formulated) were artificially contaminated with 100 ppb each of AFB₁, AFB₂, AFG₁, and AFG₂. The feeds were subjected to four different treatment conditions, including microbial application of Bacillus spp. (B285) and Saccharomyces spp. (Y833) at 1.5×10⁸ CFU/mL, a chemical binder Bentonite (positive control), and normal saline (negative control). Residual Aflatoxin concentrations were quantified using Liquid Chromatography- Mass Spectrometry (LC-MS) to determine the efficacy of aflatoxin decontamination. Nutrient stability assessment was performed on treated samples to measure the profiles of crude protein, crude fat, fat-soluble vitamins (A, D3, and K1), and 18 amino acids. The detoxification performance of the freeze-dried Bacillus spp. (B285) and Saccharomyces spp. (Y833) incorporated into poultry feed was also assessed over three months. Data were analyzed using RStudio v4.4.2.2024-10-31. Both microbial strains significantly reduced aflatoxin levels by 78.2-81.3% compared with untreated controls (p ≤ 0.05), while Bentonite achieved up to 81.6%. Nutrient stability analysis revealed that crude fat remained unchanged (p > 0.05), whereas crude protein decreased by 18.9% under Bacillus B285 (p = 0.015) but increased by 8.1% under Saccharomyces Y833. Fat-soluble vitamins responded variably: vitamin A1 increased with Bacillus (+38%) and bentonite (+37%) but decreased with yeast (-54%); vitamin D3 was markedly elevated by Bentonite (+93%) and yeast (+82%) compared with baseline (p≤ 0.05-0.001); and vitamin K1 remained stable across all treatments. Amino acid profiles showed sharp decline in case of alanine (72-81%) and histidine (65-97%), while branched- chain amino acids increased significantly, with leucine rising 27-53-fold (p ≤ 0.001) and isoleucine 9-22-fold (p ≤ 0.001). Freeze-dried Bacillus and Saccharomyces retained detoxification capacity during three months of storage, maintaining aflatoxin concentrations below 10 ppb. These findings demonstrate that while bentonite remains the most effective binder, Saccharomyces Y833 and Bacillus B285 offer biologically sustainable detoxification, with variable effects on nutrients. Their efficacy and storage stability highlighted potential for integration into safe feed production systems.