biostudies-literatureUnknown10Chen QNational Key Research and Development Program of China<i>Chromochloris zofingiensis</i> has obtained particular interest as a promising candidate for natural astaxanthin production. In this study, we established a two-stage heterotrophic cultivation process, by using which both the growth of <i>C</i>. <i>zofingiensis</i> and astaxanthin accumulation are substantially enhanced. Specifically, the ultrahigh biomass concentration of 221.3 g L^-1 was achieved under the optimum culture conditions in 7.5 L fermenter during 12 days. When scaled-up in the 500 L fermentor, the biomass yield reached 182.3 g L^-1 in 9 days, while the astaxanthin content was 0.068% of DW. To further promote astaxanthin accumulation, gibberellic Acid-3 (GA3) was screened from a variety of phytohormones and was combined with increased C/N ratio and NaCl concentration for induction. When <i>C. zofingiensis</i> was grown with the two-stage cultivation strategy, the astaxanthin yield reached 0.318 g L^-1, of which the biomass yield was 235.4 g L^-1 and astaxanthin content was 0.144% of DW. The content of the total fatty acids increased from 23 to 42% of DW simultaneously. Such an astaxanthin yield was 5.4-fold higher than the reported highest record and surpassed the level of <i>Haematococcus pluvialis</i>. This study demonstrated that heterotrophic cultivation of <i>C. zofingiensis</i> is competitive for industrial astaxanthin production.Frontiers in bioengineering and biotechnology834230https://www.ebi.ac.uk/biostudies/studies/S-EPMC8907917biostudies-literatureEffective Two-Stage Heterotrophic Cultivation of the Unicellular Green Microalga <i>Chromochloris zofingiensis</i> Enabled Ultrahigh Biomass and Astaxanthin Production.PMC8907917Chen QJin HXu QChen YHu QHan DfalseEffective Two-Stage Heterotrophic Cultivation of the Unicellular Green Microalga <i>Chromochloris zofingiensis</i> Enabled Ultrahigh Biomass and Astaxanthin Production.<i>Chromochloris zofingiensis</i> has obtained particular interest as a promising candidate for natural astaxanthin production. In this study, we established a two-stage heterotrophic cultivation process, by using which both the growth of <i>C</i>. <i>zofingiensis</i> and astaxanthin accumulation are substantially enhanced. Specifically, the ultrahigh biomass concentration of 221.3 g L^-1 was achieved under the optimum culture conditions in 7.5 L fermenter during 12 days. When scaled-up in the 500 L fermentor, the biomass yield reached 182.3 g L^-1 in 9 days, while the astaxanthin content was 0.068% of DW. To further promote astaxanthin accumulation, gibberellic Acid-3 (GA3) was screened from a variety of phytohormones and was combined with increased C/N ratio and NaCl concentration for induction. When <i>C. zofingiensis</i> was grown with the two-stage cultivation strategy, the astaxanthin yield reached 0.318 g L^-1, of which the biomass yield was 235.4 g L^-1 and astaxanthin content was 0.144% of DW. The content of the total fatty acids increased from 23 to 42% of DW simultaneously. Such an astaxanthin yield was 5.4-fold higher than the reported highest record and surpassed the level of <i>Haematococcus pluvialis</i>. This study demonstrated that heterotrophic cultivation of <i>C. zofingiensis</i> is competitive for industrial astaxanthin production.2022-01-01T00:00:00Z20222025-04-04T12:56:30.583Z2025-04-04T12:56:30.583ZS-EPMC89079173528440810.3389/fbioe.2022.834230