The inhibitory effects and mechanism of eugenol, carvacrol and thymol against Fusarium graminearum were studied by transcriptomics. The effective concentrations of eugenol, carvacrol and thymol against the mycelium growth, spore germination, and deoxynivalenol biosynthesis of F. graminearum were determined through in vitro antifungal tests. At the cellular level, the action sites were further explored by measuring the conductivity, adenosine triphosphate (ATP) level and malondialdehyde (MDA) level of the mycelium solution treated with each of the three compounds. Thymol had the best antifungal activity among the three compounds. All these compounds could damage the cell membrane integrity of F. graminearum, causing electrolyte leakage and an imbalance in energy metabolism. In addition, they could exert antifungal activity against F. graminearum through regulating the ribosome and mitochondrial structure and enzyme synthesis at the transcriptome level.

Nature fermented dry-cured hams may be contaminated by ochratoxin A (OTA) due to the colonization of OTA-producing fungi. Yeast plays essential roles in the formation of the special flavor of ham as well as the potential to retard OTA biosynthesis. In this study, the yeast diversity of Panxian hams fermented from 1 year to 2 years was investigated, revealing a total of 9 yeast genera. The dominant genus switched from Debaryomyces hansenii to Yamadazyma triangularis, while the yeast diversity increased with the prolongation of the fermentation period. Notably, Yarrawia lipolitica GZPX-3Y-1 was identified as a biocontrol yeast strain that can effectively inhibit the OTA biosynthesis up to 82% in OTA-producing modeling mediaand 55% in ham media when cocultivated with a previously identified OTA producing fungi from Panxian ham, specifically Aspergillus niger A-8. The double-plate methods experiment unveiled that Y. lipolitica GZPX-3Y-1 can only inhibit the growth of A. niger A-8 under the anoxic conditions. Characteristics of Y. lipolitica GZPX-3Y-1 were explored, showing its ability to grow at wide range of temperature (18–33 ℃) and pH levels (pH 3–12). Additionally, it exhibited tolerance to high salt conditions (8%) and demonstrated lipolysis ability without hemolytic ability. These findings indicate the great potential of Y. lipolitica GZPX-3Y-1 to be applied in the fermentation of Panxian ham as a biocontrol strain.