Acuinuga. Acuicultura y Nutrición de Galicia


23-06-11 |

Novel Applications for Microalgae


Our Aquaculture Division is carrying out a R&D Project on new applications for microalgae. Microalgae aquaculture is gaining importance recently, with an estimated world output in excess of 5,000 metric tonnes/year (excluding the addition of value resulting from their processing and refining). Beyond other applications such as biofuel production, our interest derives from their proximate composition, rich in highly digestible proteins and carbohydrates, and containing a lipid fraction comprising up to 70% of their dry weight, which makes them particularly attractive for nutritional applications. Other valuable components present in microalgae are vitamins (A, B, C, E), provitamins and pigments such as chlorophyll, carotenoids (astaxanthin, betacarotene, lutein) and phycobiliproteins, all of them commercially relevant.

The most interesting fatty acids for our aims are those belonging to the omega-3 and omega-6 families. This polyunsaturated fatty acids (PUFAs) cannot be synthesized by most animals, therefore they must be supplied in the diet. The traditional source for these fatty acids is fish oil, with a more competitive market price than PUFAs originating from microalgae.  Recent evidence, however, indicates a more efficient metabolisation of microalgal PUFAs compared to fish oil PUFAs, which combined with several limitations for the use of fish oil (rancidity, toxin accumulation, strong fish flavour, etc.) is pushing forward a number of industrial projects for microalgae cultivation. A good example is the inclusion of microalgae-derived DHA (a PUFA naturally present in breast milk but absent in cow's milk, essential for correct brain, eye and heart development) in infant formulae and adult dietary supplements, with an estimated market value of 10,000 million euro in 2010 and already marketed in 60 different countries worldwide.

We are focusing on the production of Nannochloropsis oculata, possibly the most important microalgae for the cultivation of the rotifer Brachionus plicatilis. This rotifer, in combination with the crustacean Artemia salina is the basis for the larval nutrition of several species on which we are focusing, including sole, turbot, striped mullet, black spot sea bream and sea bass. Containing 47% protein and 23% lipids, of which 36% is EPA and 5% ARA, rich in chlorophyll and vitamin C, Nannochloropsis represents an essential piece in the design of a nutritional strategy for the cultivation of new species. Results obtained to date in this project have been the production of pathogen-free microalgae in different formats (pasteurised fresh, frozen paste and dry powder), and the attainment of output volumes suitable for industrial applications.  With this new product range we complement our catalogue of nutritional tools, allowing also for their further valorisation through the extraction of commercially-relevant components.

Click here to see the Technical Sheet of Nannochloropsis