2026 年 94 巻 10 号 p. 103001
Yeast cell counting and viability assessment are crucial for industrial processes utilizing yeast cells. However, conventional methods for yeast cell counting and viability assessment are often time-consuming, labor-intensive, and less suitable for rapid microbial studies and acute cytotoxicity research in the food and pharmaceutical industries. Therefore, the development of rapid and sensitive methods for yeast cell counting and viability evaluation is highly desirable. In this study, we employed a chronoamperometric technique based on a widely used 1-methoxy-5-methylphenazinium methyl sulfate (mPMS)/[Fe(CN)6]3− (FeCN) double-mediator system for yeast cell counting through the electrochemical monitoring of intracellular NADH, a key indicator of cellular metabolic activity. The oxidation current in chronoamperometry measured at +0.5 V versus Ag/AgCl using a screen-printed carbon electrode (SPCE) exhibited an excellent linear relationship with the number of metabolically active fission yeast cells. The linear detection range of our electrochemical counting method was wider than that of the conventional colorimetric water-soluble tetrazolium (WST-1) assay. Furthermore, the electrochemical approach overcomes several limitations associated with conventional optical methods, including scattering effects, turbidity of cell-suspended media, and prolonged incubation times. In addition, this method can be applied for evaluating the acute cytotoxicity of fast-acting compounds such as itaconic acid (IA) in yeast cells.
