Astaxanthin is a main carotenoid pigment. Fed-batch fermentation bioprocesses of
astaxanthin in 2.0 M3 fermentor have been investigated. Moreover, pH shift control was
employed in fed-batch fermentation at 2.0 M3 scale. The results of astaxanthin fermentation
showed that the fed-batch fermentation with pH shift strategy was the best among all
the experiments, and the maximum astaxanthin concentration of 39.47 mg/L was achieved
at 132 h.