초록
<P><B>Abstract</B></P> <P>In the present study, high light and nitrogen starvation with glucose-fed to the culture was found efficient to induce astaxanthin accumulation in <I>Chlorella zofingiensis</I>. Therefore, a two-step cultivation strategy including high biomass yield fermentation and outdoor induction with an energy-free RFP was conducted. During the fermentation, the highest cell density of 98.4gL<SUP>−1</SUP> and astaxanthin yield of 73.3mgL<SUP>−1</SUP> were achieved, which were higher than those so far reported in <I>C. zofingiensis</I>. During the outdoor induction, astaxanthin content was further increased by 1.5-fold leading to the highest astaxanthin productivity of 5.26mgL<SUP>−1</SUP> day<SUP>−1</SUP> under an optimal dilution of 5-fold. Our work thus provided an effective two-step cultivation strategy for production of astaxanthin by <I>C. zofingiensis</I>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> HL+G−N was found efficient to induce astaxanthin accumulation in fermented cells. </LI> <LI> A two-step cultivation strategy was proposed and conducted <I>in C. zofingiensis</I>. </LI> <LI> Higher cell density and astaxanthin yield were achieved in the fermentation. </LI> <LI> Astaxanthin content in fermented cells was increased during the outdoor induction. </LI> </UL> </P>