Effect of different strains of Saccharomyces cerevisiae on reduction of aflatoxin B1, B2, G1 and G2

Saccharomyces cerevisiae is one of the major microorganisms widely used in food fermentation, and the ability of its strains to reduce the level of aflatoxins has been reported. The aim of this study was to test the capability of S. cerevisiae strains on reduction of aflatoxin B1, B2, G1 and G2 levels. For this reason, standard strains of PTCC 5052 and PTCC 5269 were cultivated on Yeast Mold Agar. Afterwards, cell suspension containing 107 cell/ml was spiked into PBS (pH= 7.2) containing 20 ng/ml of each B1, B2, G2 and G1 aflatoxins. Aflatoxin levels were determined using HPLC and immunoaffinity columns. The results show that different strains of S. cerevisiae reduced the aflatoxin levels in a different rate and various durations. At the time 320 min the PTCC 5052 strain reduced the aflatoxin B1, B2, G1 and G2 levels to 11.2 , 13.9, 8.0 and 8.1%, respectively; meanwhile, these results for the PTCC 5269 strain 9.5, 8.0, 2.3 and 16.2%, respectively. Results suggested that different strains of S. cerevisiae had a different reduction rate on aflatoxins. Moreover, the strains need to have sufficient time to absorb the maximum amounts of aflatoxin.