As indicated by Fig. 5, C. curvatus grew well in the fermentor with no lag phase observed. By day two, the biomass DW was 21.6 g/L and the cells exhausted almost all of the sugars initially in the medium. During the first two days, the average biomass productivity was
10.6 g/L-day and the average sugar utilization rate was 21.7 g/L- day. The cell yield was 0.48 g cells/g sugars. After 48 h, however, cell growth slowed down significantly though syrup was supplemented at 48 and 60 h, respectively. From day 2 to day 3, cell growth rate was 2 g/L-day while total sugar utilization rate was 27.7 g/L-day. The low cell yield at this later stage could be due to lack of nutrients since only sugars were added to the fermentor without nitrogen and other elements. Lipid content of the day 3 cells was 50.8 ± 0.3%
measured by the conventional lipid extraction assay. The overall lipid yield was 0.20 g/g sugar which is close to the highest practical yield of 0.20–0.22 g/g glucose [34].