The Viability Change of Yeast Cell Responding to Trehalose Accumulation and Maintaining Neutral Trehalase Activity under Extracellular pH Acidified by $H_2SO_4$

Saccharomyces cerevisiae KNU5377 (KNU5377) and S. cerevisiae ATCC24858 (ATCC24858) were exposed to $H_2SO_4$ as a stress, which was added at various concentrations to a YPD media. The growth of KNU5377 was reduced to approximately 60% in the YPD media containing 40 nm sulfuric acid when compared to the non-stressed condition. When their growth was monitored during an overnight culture, two strains, KNU5377 and ATCC24858, could not grow when exposed to over 50 mM of sulfuric acid. After a short exposure to this acid for 1 h, KNU5377 exhibited stronger resistance against $H_2SO_4$ than ATCC24858. The neutral trehalase activity of KNU5377 unchanged despite under various concentrations of $H_2SO_4$. In contrast, It at of ATCC24858 was much low at higher $H_2SO_4$concentrations. Trehalose, a non-reducing disaccharide, was maximally accumulated after a short exposure to 60 nm $H_2SO_4$ for KNU5377, but it was reduced under more severe stressful conditions. These results suggest that KNU5377 should modulate the trehalose concentrations under the severe stress condition of high sulfuric acid concentrations. The most highly induced protein in the KNU5377 exposed to sulfuric acid was found to be an approximately 23 kDa protein, which was revealed to be the 605 large subunit ribosomal protein, Ll3 by FASTA search results.