Antagonistic effects of volatile organic compounds of Saccharomyces cerevisiae NJ-1 on the growth and toxicity of Aspergillus flavus

Aspergillus flavus is capable of producing highly toxic aflatoxins that can infest grains, cereals and nuts, causing serious economic losses and food safety concerns. Therefore, it is especially necessary to study safe and efficient biological control methods. In this paper, an edible strain of Saccharomyces cerevisiae NJ-1 was isolated from pomace of Ficus carica, the inhibitory effects of S. cerevisiae NJ-1 volatile organic compounds (VOCs) on the growth and aflatoxin production of A. flavus were studied, and the mechanisms of inhibitory effects were initially investigated. The results revealed that the inhibitory effects of S. cerevisiae NJ-1 VOCs on the growth, sporulation, and conidial germination of A. flavus varied significantly with the preculture time. Scanning electron microscopy (SEM) images showed that the morphology of the mycelium of A. flavus treated with VOCs was distorted. Meanwhile, the absorbance at 260 nm and 280 nm had a significant increasing trend, which indicated that the cell membrane was one of the action targets of S. cerevisiae NJ-1 VOCs. A total of nine compounds were identified from S. cerevisiae NJ-1 VOCs by headspace solid-phase microextraction gas chromatography (GC/MS). Among them, 3-methyl-1-butanol showed a significant inhibitory effect on A. flavus and may play an important role in the inhibitory effect of NJ-1 VOCs. The study showed that S. cerevisiae NJ-1 VOCs have great potential to be developed as biopesticides for the control of A. flavus.