Accumulation and conversion of β-carotene and astaxanthin induced by abiotic stresses in Schizochytrium sp.

Astaxanthin is a kind of ketone carotenoid belonging to tetraterpenoids with an excellent antioxidant activity and it is widely used in nutrition and health-care industries. This study aimed to explore the effect of different abiotic stresses on carotenoid production in Schizochytrium sp. Firstly, the characteristics of carotenoid accumulation were studied in Schizochytrium sp. by monitoring the change of carotenoid yields and gene expressions. Then, different abiotic stresses were systematically studied to regulate the carotenoid accumulation. Results showed that low temperature could advance the astaxanthin accumulation, while ferric ion could stimulate the conversion from carotene to astaxanthin. The glucose and monosodium glutamate ratio of 100:5 was helpful for the accumulation of β-carotene. In addition, micro-oxygen supply conditions could increase the yield of β-carotene and astaxanthin by 25.47% and 14.92%, respectively. This study provided the potential regulation strategies for carotenoid production which might be used in different carotenoid-producing strains.