In Vitro Aflatoxin B1 Binding by the Cell Wall and (1→3)-β-d-Glucan of Baker's Yeast

Abstract

The aim of this study was to evaluate the ability of heat-killed baker's yeast (HKBY), the cell wall of baker's yeast (CWBY), and cell wall (1→3)-β-d-glucan of baker's yeast (BGBY) to bind aflatoxin B₁ (AFB₁) in phosphate-buffered saline (PBS) spiked with 0.5 μg/mL AFB₁. Baker's yeast ( Saccharomyces cerevisiae) was heat killed by autoclaving at 121°C for 10 min. The cell wall was physically extracted, and (1→3)-β-d-glucan was extracted by a modified method. The concentration of AFB₁ was determined by high-performance liquid chromatography after exposure to binders for three contact times, 30 min, 5 h, and 24 h, at room temperature. AFB₁ binding by HKBY, CWBY, and BGBY was 6.30 to 46.34%. The lowest binding capacity was found for HKBY with a contact time of 30 min, and the highest binding capacity was found for BGBY with a contact time of 24 h. Among binders, CWBY had the highest binder-AFB₁ complex stability during washing with PBS, and the lowest stability was found for HKBY complexes. Results of this study indicated that BGBY was the most effective binder, and more exposure to BGBY removes more AFB₁ from PBS.

Keywords: (1→3)-β-d-Glucan; Aflatoxin B1; Baker's yeast; Binding capacity; Cell wall.