Figure 7
Biomass and CYP3A4 activity during cultivation of Y. lipolytica YL22 in bioreactor. Time course of biomass concentration and volumetric whole-cell CYP3A4 activity determined during fed-batch cultivation and ethanol induction. Open symbols, biomass concentration determined as cell dry weight; closed symbol, CYP3A4 expression levels measured as volumetric whole-cell activity of 6beta-hydroxyprogesterone formation determined by separate activity assays in test tubes. The Roman numerals show the following process phases: I) batch growth with glucose; II) fed-batch growth over 10 h with exponential addition of glucose at an exponentially increasing feed rate; III) induction phase of about 36 h with a low linear addition of ethanol.