ABSTRACT
Nutritional composition of algae is described as containing mainly proteins, carbohydrates, lipids and trace nutrients, including vitamins, and trace elements, thus entailing compounds with all characteristics to be a great natural supplement in animal feed. Both micro- and macroalgae have been considered a rich source of different types of carotenoids, highly bioactive compounds, such as antioxidant compounds and so prevent oxidative stress in aquaculture organisms. The macroalgae present a higher content in polysaccharides, important bioactive compounds. Algal species can vary significantly in nutritional value, as a function of the prevailing culture conditions, especially microalgae. Most of studies examining the immunostimulatory ability of algae have been carried out in vitro with algal extracts. Studies on oral administration are scarce and usually include only algal extracts or isolated compounds instead of whole algae. The production of single cell detritus from several genera of macroalgae, such as Laminaria, Macrocystis and Sargasun, can be obtained either by enzymatic or bacterial action or both.
