Activity of Yeast Cells Solubilized in a Water-in-Oil Microemulsion

Abstract

The respiration of Baker’s yeast solubilized in a water-in-oil microemulsion (water content up to 4% (v:v)) was investigated by following the consumption of oxygen after addition of glucose by a Clark electrode. The activity of cells in the concentration range 1-100 mg/mL (ca. 106-108 cells/mL) could thus be measured in the organic medium and followed as a function of time. The influence of added ethanol and of fermentable sugars has also been tested. The results show that the polarographic method is reliable for studies of cells solubilized in organic solvents and that yeast in this organic medium although displaying lower rates, has the same behavior as in water concerning the oxygen consumption and ethanol fermentation.