Microalgae are photoautotrophic organisms with high potential biological, ecological and economic. Due to its great applicability microalgae has been the focus of many studies in recent years. The most common application of microalgae is verified in aquaculture for direct or indirect feeding of aquatic organisms of economic interest. Environmental applications of microalgae include CO2 biofixing and production of biofuels. Studies are being carried out for the use of microalgae in wastewater treatment of industrial process numbers, for biological detoxification , heavy metal removal and as bioindicators. In agriculture the biomass can be used as a soil biofertilizer. Species commonly used in aquaculture such as Nannochloropsis oculata and Thalassiosira weissflogii present a high absorption capacity of atmospheric carbon dioxide.
The biotechnological potential of microalgae is mainly due to the identification of various substances synthesized by these organisms. The immense biodiversity and the consequent variability in the biochemical composition obtained in the biomass microalgal crops, allied to the genetic improvement in large scale, have allowed certain species are used commercially. The main commercially cultivated microalgae are Chlorella and Arthrospira genera for addition to health foods and Haematococcus pluvialis to obtain astaxanthin. In this sense, crops of microalgae have been carried out to produce biomass both for use in food preparation and for obtaining high value natural compounds in the market worldwid e. Among the many compounds can be cited: polyunsaturated fatty acids (PUFA) , carotenoids, phycobilins , polysaccharides, vitamins, sterols and various natural bioactive compounds, such as antioxidants, cholesterol lowering, among others which can be used in functional foods due to their nutritional and pharmaceuticals properties. PUFA have a very promising market in biotechnology, especially in the food industry functional.
Because they are capable of synthesizing toxins, microalgae can produce a range of bioactive molecules with antibiotic, anticancer, anti-inflammatory, antiviral, cholesterol-lowering, enzymatic and other pharmacological properties. Beta carotene can accumulate up to approximately 10% in halotolerant species such as Dunaliella genus and has application as a dye and may act as a pro-vitamin A, antioxidant product and against degenerative diseases such as cancer. Too many compounds of commercial interest can be obtained by cultivating microalgae and the interest in sustainable technologies brings the need to continuous search for strains capable of synthesize large quantities of specific compounds e the knowledge to enhance the synthesis of these products. In this way, they are also research is needed to develop and commercial scale production systems to enable some of the known systems. It is therefore important to identification of products that can be extracted from microalgae, as well as possible biological activities through clinical, metabolic and toxicological studies.