Abstract:To get a better system for biotransformation and analysis of coumarins, cell suspension cultures of the yeast (Sacharomyces cerevisiae) were established. The best primary cultural density and the pH value of the system for preliminary transformation test of coumarins were determined by investigating the change of cell morphology, growth curve and the pH value of the cultures during a yeast cell growth cycle. Results showed that the best cultural density, temperature, shaking speed and the pH value were 8×106 /ml, 27±1 ℃, 110 r/min and 4.5~5.5, respectively. Besides, dark cultures were preferred. It was concluded that coumarins could be absorbed and transformed in the achieved yeast cell cultures.