Abstract
Metabolomics is a newly emerging field of ‘omics’ research that is used for detection of small molecules or metabolites in biological fluids such as amino acids, sugars, and organic acids. Capillary electrophoresis-mass spectrometry (CE-MS) is one of the most promising approaches for comprehensive and quantitative analysis of the metabolites. The aim of the present study was to investigate the response to environmental stress using model organisms such as yeast (Saccharomyces cerevisiae) cells. CE-MS method was applied to the determination of qualitative and quantitative difference of the cationic metabolites. This paper shows that a stress response to high hydrostatic pressure (40 MPa, 16 hours) resulted in an increase in the concentration of many intracellular amino acids. Amino acid metabolism would be activated in the stress response in the yeast cells. Furthermore, it was particularly noticeable that a series of hydrophobic amino acids, such as valine, leucine, isoleucine, and phenylalanine, was increased. From the results of gene expression, the yeast cells had been damaged by the pressure treatment. Therefore, we speculated that the amino acid increases were observed caused by a decomposition product of proteins.
