Rhizopus oryzae lipase (ROL) was displayed on the cell surface of Saccharomyces cerevisiae via the Flo1N-terminal region (1100 amino acids), which corresponds to a flocculation functional domain. The activity of lipase-displaying yeast whole-cell biocatalysts was enhanced 7.3-fold by incubation of the yeast cells at 20 degrees C in distilled water for 8 days after 8 day cultivation. The amount of lipase molecules present in cell wall and intracellular fractions was found to be increased 4.5- and 1.8-fold, respectively, by incubation, which proves that ROL molecules are expressed during incubation. The ROL-displaying yeast whole-cell biocatalyst with enhanced activity was successfully catalyzed by optical resolution of the pharmaceutical precursor (R, S)-1-benzyloxy-3-chloro-2-propyl monosuccinate. Moreover, it showed stable activity through at least eight reaction cycles. These results demonstrate that ROL-displaying yeast cells with enhanced activity by incubation in distilled water are very effective in industrial bioconversion processes.