Determinação do perfil de carotenoides microalgal em cultivo heterotrófico

Abstract

Carotenoids are important compounds known for their bioactive activities, and are widely used in the food, chemical and pharmaceutical industries. Among the most well-known carotenoids, β-carotene is the most used commercially; however, lutein has been growing positively on the market, mainly because it is the only carotenoid to accumulate at a specific site in the human body and function as part of the system, along with its oxidized derivatives that accumulate in the macula. Microalgae are recognized as a natural source of carotenoids commonly produced by photoautotrophic cultures; on the other hand, heterotrophic metabolism for the production of natural pigments has attracted much attention for commercial applications, for overcoming difficulties associated with CO2 and light avoid contamination problems. In this sense, the aim of this work was to evaluate the carotenoid profile as a function of the growth curve in Chlorella vulgaris biomass, from the heterotrophic culture, using glucose as an exogenous carbon source. The results showed a profile of 7 compounds with no qualitative changes in the whole growth kinetics, reaching a maximum cell biomass of 2200mg.L-1 and productivity of 12. 15mg.L.h-1. The total carotenoid content was 381. 69μg.g-1, expressing that the best condition for biosynthesis occurred in 96h, with the major carotenoids all-trans-lutein (131, 35μg.g-1) and all-trans-β-carotene (80. 99μg.g-1). However, considering the growing market for lutein and the fact that microalgae produce higher amounts of free lutein compared to current sources, the 72h time is suggested as the best time for production of lutein, where the amount presented was (143. 53μg.g-1). Through the results found, carotenoids have been shown to be synthesized in the dark and heterotrophic cultivation seems to be an interesting option for the commercial production mainly of lutein, since they have advantages with high content of free lutein and a higher rate and growth.