AUTHOR=Ming Xiaobing , Wang Yong , Sui Yuan 

TITLE=Pretreatment of the Antagonistic Yeast, Debaryomyces hansenii, With Mannitol and Sorbitol Improves Stress Tolerance and Biocontrol Efficacy

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.00601

DOI=10.3389/fmicb.2020.00601

ISSN=1664-302X

ABSTRACT=<p>The effect of exogenous mannitol and sorbitol on the viability of the antagonist yeast, <italic>Debaryomyces hansenii</italic>, when exposed to oxidative and high-temperature stress was determined. Results indicated that both the 0.1 M mannitol (MT) and 0.1 M sorbitol (ST) treatments improved the tolerance of <italic>D. hansenii</italic> to subsequent oxidative and high-temperature stress. MT or ST cells had a significantly higher level of cell survival, elevated the gene expression of <italic>catalase 1</italic> (<italic>CAT1</italic>) and <italic>copper-zinc superoxide dismutase</italic> (<italic>SOD1</italic>), as well as the corresponding enzyme activity. Treated cells also exhibited a lower accumulation of intracellular reactive oxygen species (ROS), and a higher content of intracellular mannitol and sorbitol relative to non-treated, control yeast cells, when exposed to a subsequent oxidative (30 mM H<sub>2</sub>O<sub>2</sub>) or heat (40.5°C) stress for 30 min. Additionally, MT and ST yeast exhibited a higher growth rate in kiwifruit wounds, and a greater ability to inhibit postharvest blue mold (<italic>Penicillium expansum</italic>) and gray mold (<italic>Botrytis cinerea</italic>) infections. The present study indicates that increased antioxidant response induced by mannitol and sorbitol in <italic>D. hansenii</italic> can enhance stress tolerance and biocontrol performance.</p>