Striking mycotoxin tolerance and zearalenone elimination capacity of the decaying wood associated yeast Sugiyamaella novakii (Trichomonascaceae).

BACKGROUND: Mycotoxin-producing fungal species and their mycotoxins pose a global threat for crop production and for human and animal health. Given the increasing demand for healthier food and feed, alternative non-pesticide approaches for reducing fungal infections in crops and eliminating mycotoxin contamination in feedstock are becoming more prevalent. For such purposes, yeast species can be good candidates. Thus, the present study examined the mycotoxin tolerance and mycotoxin elimination ability of several yeast strains belonging to the Trichomonascaceae family.

RESULTS: While none of the tested yeasts inhibited the growth of different Fusarium species, several yeast strains exhibited tolerance to Fusarium mycotoxins such as deoxynivalenol, zearalenone, T-2 toxin, and fumonisin B1. Sugiyamaella novakii strains displayed exceptional tolerance for the tested mycotoxins. Besides, phylogenetic analyses suggested that tolerant species clustered more closely to each other than to the sensitive species. Although whole genome sequencing of S. novakii NCAIM Y.00986 revealed several enzyme-coding genes that may have a role in mycotoxin elimination, significant mycotoxin elimination was not achieved in the case of deoxynivalenol, T-2 toxin, and fumonisin B1. However, S. novakii successfully eliminated zearalenone, likely due to cell wall adsorption rather than enzymatic degradation.

CONCLUSIONS: This study highlights the potential of S. novakii for zearalenone detoxification and emphasizes the role of yeast cell walls in mycotoxin mitigation strategies.