Transcriptomics Analysis of Formic Acid Stress Response in Saccharomyces Cerevisiae

Abstract Formic acid is a representative small molecule acid cell inhibitor in lignocellulosic hydrolysate, which can inhibit the growth of yeast cells in the process of alcohol fermentation. However, the mechanism of formic acid cytotoxicity remains largely unknown. This study aimed to study the cytotoxicity of formic acid stress to Saccharomyces cerevisiae . We evaluated the effects of formic acid on growth metabolism and cell morphology of yeast cells, and comprehensively and systematically analyzed the molecular mechanism of formic acid stress tolerance through transcriptome technology. The results showed that when the concentration of formic acid was 1.8 g/L, the growth of yeast cells was significantly inhibited, the cell surface was wrinkled, and the adhesion between cells was observed, and the cell wall and cell membrane of yeast were destroyed by changing the structure of proteins and carbohydrates, resulting in cell damage. Transcriptome sequencing results showed that formic acid stress inhibited protein biosynthesis, induced oxidative stress, resulted in autophagy, impaired intracellular ATP production and increased consumption, and then impaired normal physiological and metabolic functions of cells. Yeast cells provide sufficient ATP by accelerating glucose metabolism, enhancing electron transport and ATP synthesis more energy to resist formic acid stress, and reduce the expression of genes related to energy metabolism such as intracellular amino acids to achieve an energy-saving strategy, In addition, it can also induce sexual reproduction and spore formation to improve cell tolerance to formic acid. This study initially revealed the molecular response mechanism of S. cerevisiae under formic acid stress, and provided a scientific basis for further research on methods to improve the tolerance of cell inhibitors in lignocellulose hydrolysate.