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Isochrysis galbana is a marine microalga which highlights by containing a great diversity of antioxidant biomolecules. It shows a high content of lipids that can be used in aquaculture and biofuel, its high polyunsaturated fatty acid profile such as DHA (docosahexaenoic acid) or for having high fucoxanthin content (carotenoid group). For a century, this microalga is very well known as feed for bivalves, larva of fish, crustaceans, and mollusks. Transesterification is the necessary reaction to be able to derivative the fatty acids in methylated fatty acids (AGM) and thus be able to identify and quantify them. It is a key step to optimize and therefore know the improvement of the obtained fatty acid profile of study biomass. Hence, this work presents the significant difference of eight methods for obtaining fatty acids from the direct and indirect transesterification reaction (MTD and MTI, respectively). Moreover, acidic and alkaline catalysts were also used (AC1, AC2 and AL1 and AL2). The results presented better contents of AGMs (methylated fatty acids) respecting dry biomass in the MTD-AL1 method with ~ 6% and a relative abundance of DHA of ~ 12 % in MTI-AL2. In addition, the most abundant fatty acid profile was MTD-AL2 with 57.66 % in polyunsaturated. On the other hand, thanks to the addition of an internal standard in the experiences, it was possible to identify that the MTD-AL1 and MTI-AC1 methods were the most efficient in the transesterification obtained with ~ 93 % and ~ 87 %, respectively. Therefore, the method that is selected for the correct reading of fatty acids present in any biomass is relevant to detect a profile with more unsaturation as has been purchased with the microalga I. galbana. [ABSTRACT FROM AUTHOR]

The best choice for feeding the newborn child is breast milk, and when it is not possible to breastfeed a baby, the breast milk is replaced by lacteal formula, which is why numerous studies focus their attention on the analysis of the diverse components of baby formula as well as functions in the breastfed baby. Fatty acids are components of great nutritional importance in the fetus and in the newborn child. Nowadays it is estimated that the fetus, during the last trimester of the gestational period and the newborn child, during the first six months of life, need a great contribution of araquidonic and docosahexaenoic acids, due to the fact that the speed of transformation of the predecessors to the hepatic level are not sufficient to cover the metabolic requirements of these fatty acids and it is the mother who contributes them through placental transport during gestation and her milk during lactation. The Organization of Food and Agriculture (FAO), the World Health Organization (WHO), the European Society of Gastroenterology, Hepatology and Pediatric Nutrition (ESPGHAN) and the American Academy of Pediatrics recommend that lacteal formula imitate the composition of the breast milk, especially in the fatty polyunsaturated acids (PUFA). [ABSTRACT FROM AUTHOR]

Crypthecodinium cohnii is a heterotrophic dinoflagellate that can achieve a lipid content greater than 20% on dry weight. DHA can represent up to 40% of the total fatty acids. Our objective was to investigate the variation in fatty acid content when growth conditions are optimal compared with when there is limited growth, due to the absence of nitrogen in the media. Nitrogen-limited growth conditions caused the cells to stop dividing and accumulate lipids, principally as docohexanoic acid (DHA). Oxygen availability in the culture favoured DHA accumulation. In the cultures without nitrogen and with oxygen availability there was a lipid cell content 3,18 times higher than in the control condition (with nitrogen and air), and 2,25 higher than those without nitrogen and air. C. cohnii can be used as an optimal DHA source for the production of phytodiets in aquaculture. [ABSTRACT FROM AUTHOR]