Figure 4

Carotenoid composition of CSR19 during fermentation in 7.5-L bioreactor. HPLC profiles sampling at 24 h (a), 40 h (b), and 60 h (c). Major carotenoid composition monitored at intervals of 8–12 h throughout the culture period (d). Detection wavelength: 480 nm. Details of the two major peaks (1 astaxanthin, 2 HDCO) are shown at upper right corner. The maximal astaxanthin peak was normalized as 100 mAU for evaluation of changes in HDCO proportion. The HDCO proportion increased during cell growth (log and exponential phases and declined ~30% in the stationary phase, during which astaxanthin proportion increased accordingly. At 60 h, astaxanthin (84.0%) and HDCO (13.4%) were the only notable carotenoids; others were present in trace amounts.