Organic Solvent Tolerance of Bacteria Estimated by a High Cytotoxic Organic Solvent Diluted with <i>n</i>-Hexadecane

Organic synthesis using biocatalysis has been possible by performing reactions in predominantly water-free media, or in water-organic biphasic systems. If whole cells are used for water-organic biphasic systems, organic solvent tolerance is required. Several methods were used for the estimation of organic solvent tolerance in microorganisms. We considered whether the concentration of an organic solvent could be varied in the evaluation of organic solvent tolerance on the solid medium. For this, a method of dilution with a low cytotoxic organic solvent was employed and the cytotoxicity of the organic solvent was decreased with the dilution.