Conditions for the Production of Carotenoids by Thraustochytrium sp. ATCC 26185 and Aurantiochytrium sp. ATCC PRA-276

ABSTRACT

There is an intensive search for alternative sources of bioactive molecules, including carotenoids, due to their potent antioxidant activities. Some aquatic microorganisms, such as thraustochytrids, have the ability to synthesize large amounts of carotenoids. The objective of this investigation was to study the effect of growth conditions (carbon: total nitrogen ratio and cultivation system) on the production of carotenoids by Thraustochytrium sp. and Aurantiochytrium sp. For Thraustochytrium sp. culture, carotenoid production was lowered by increasing the initial glucose concentration or continuous supply of glucose and nitrogen. For Aurantiochytrium sp. culture, restraining nitrogen supply or especially using a continuous supply of glucose and total nitrogen decreased total carotenoid productivity. The highest total carotenoid production (2.22 mg/L, w/v) was obtained after 192 h of cultivation of Thraustochytrium sp. using initial concentrations of 30 g/L glucose and 2.4 g/L total nitrogen (batch system). The highest production of astaxanthin was achieved in the fed-batch system with a C/N ratio of 6.2 for Thraustochytrium sp. and 40 for Aurantiochytrium sp. Therefore, it was found that the carotenoid profile can be changed by modifying the growth conditions, which can be useful for the food industry and biotechnological applications.

KEYWORDS:

• Carbon source
• carotenoids
• culture system
• nitrogen source
• Thraustochytrids

Acknowledgments

This study was supported by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior of Brazil (CAPES) and developed at the Portuguese Institute of Sea and Atmosphere (IPMA) in Lisbon, PT, with the aid of a scholarship grant awarded to the first author by the Doctoral in the Country with Internship Abroad Programme (PDEE) (grant no. 6906/10-9). The authors also thank the ALGAENE Project and Depsiextracta Biological Technologies, Lda. for their support.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior [6906/10-9].