Astaxanthin production optimization from Rhodosporidium toruloides G17 using potato hydrolysate and its antioxidant activity

Astaxanthin (ASTX), a fat-soluble red pigment, belongs to a group of carotenoids with various compounds that are responsible for biological activities. This research investigated the ASTX production of gamma-mutated yeast strain Rhodosporidium toruloides G17 using potato hydrolysate and urea as replacement medium components. Under optimal conditions, the gamma-mutated yeast G17 was cultivated in 29.39 g/L total sugar from potato hydrolysate, 1.02 g/L urea as a nitrogen source, 4.09 g/L MgSO 4 , and 10.05% yeast, resulting in the highest ASTX yield of 2,181.14 μg/mL. For the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, at an IC 50 = 9.98 μg/mL, the ASTX crude extract showed greater antioxidant activity than α-tocopherol (IC 50 = 119.66 μg/mL). This research suggests that ASTX from R. toruloides G17 is a promising antioxidant agent for nutraceutical and pharmaceutical applications and that potato hydrolysate is an efficient carbon source for yeast culturing in batch mode to obtain ASTX.