Yeast suppresses Aspergillus parasiticus growth and aflatoxins synthesis: Finding a new fungal antagonistic strain based on stored marinade

Aspergillus parasiticus is prone to producing toxic and carcinogenic aflatoxins (AFs) and posing risks to food safety. This study aims to explore the effect of yeasts isolated from marinade on the growth of A. parasiticus and to evaluate the inhibitory effects of these yeasts on the biosynthesis of AFs and their ability to remove AFs. Six yeast strains were screened through 18S rDNA and ITS rDNA gene sequence analysis, and among them, Candida tropicalis , Pichia kudriavzevii , Trichosporon asahii , Lodderomyces elongisporus and Pichia fermentans showed vigorous growth activity in the stored marinade. P . fermentans and L. elongisporus culture solutions significantly inhibited the growth and mycelial differentiation of A. parasiticus and effectively removed AFB 1 . The volatile compounds of P . fermentans and L. elongisporus significantly inhibited the growth of A. parasiticus , with inhibition rates of 72.10% and 67.03%, respectively. In addition, P . fermentans and L. elongisporus were co-cultured with A. parasiticus in marinade for seven days. The inhibition rates of AFB 1 synthesis were 69.06% and 61.78%, while the inhibition rates of AFG 1 were 65.89% and 60.02%, respectively. Hence, P . fermentans and L. elongisporus can be used as fungal antagonistic strains to help reduce AFs contamination in the marinade and its products.