Physiological Characteristics and Transcriptomic Analysis of Saccharomyces cerevisiae under Carvacrol Stress

Abstract

This study investigated the effect of carvacrol stress on the physiological characteristics and transcriptome of Saccharomyces cerevisiae, a common spoilage yeast in fruit and vegetable products. The results showed that the minimum inhibitory concentration (MIC) of carvacrol on S. cerevisiae was 160 mg/mL. With the increase in temperature (20–40 ℃), the inhibitory effect of carvacrol (160 mg/mL) on yeast growth gradually increased. Environmental pH (3–4.5) had no significant impact on the inhibitory effect of carvacrol. However, the addition of fructose (20–80 g/L) significantly reduced the antifungal activity. Carvacrol treatment damaged the structure of the cell envelope of S. cerevisiae, increased the plasma membrane permeability and caused plasma membrane depolarization, resulting in leakage of intracellular substances, a decrease in mitochondrial membrane potential, an imbalance in intracellular Ca2＋ homeostasis, and a decrease in intracellular ATP content. The transcriptomic analysis revealed that carvacrol stress inhibited the biosynthesis of mitochondrial respiratory chain complexes, ATP synthase and mitochondrial ribosome (MR) proteins, which could block electron transport along the respiratory chain and interfere with life activities related to MR.

Keywords

• carvacrol; saccharomyces cerevisiae; physiological characteristics; transcriptomic analysis; antimicrobial mechanism