Any discussion about Omega-3 fatty acids is not complete unless Algae is brought into the picture, for it is the food growing abundantly in the ocean that is eaten by the fish which is the best known source of DHA and EPA, two most widely recognized essential fatty acids needed for healthy living. One of the advantages of Algae being used for direct extraction of Omega-3 acids is that it is free from mercury contamination when produced under controlled conditions. Algae is also a rich source of protein containing branched chain amino acids. In the quest for bio-fuels to substitute the fossil fuels, Algae is considered as a promising future source though price-wise it may not be cost effective at to day's fuel prices.
Algae belong to a large and diverse group of simple auto-tropic microorganisms, some unicellular and others multicellular in nature. In their most complex existence, sea weeds represent the largest form used in the manufacture of functional food ingredients with viscosity modifying properties. Algae is a eukarytic organism with a nucleus enclosed within a membrane and chloroplasts bound in one or more membranes which confers on Algae the photosynthetic capability. All algae have the photosynthetic machinery derived from Cyanobacterium and produce oxygen as a by-product of its growth. There are 6000-7000 species of Algae and their origin dates back to 2 billion years, being the predecessors of the green plants as we see to day. Algae is estimated to provide 90%of oxygen in the planet while plants account for the balance. Algae is increasingly being touted as the most potential CO2 capture module of future, the biomass being considered as a source of high quality proteins, lipids for food purpose as well bio-fuels, nutraceuticals, animal feeds and fertilizers. A startling discovery, confirmed through clinical trials, credits algae with the ability to reduce or prevent side effects of chemotherapy treatment for cancer.
Nanno chloropsis, Chlorella vulgaris and Spirulina sp are being tried for large scale production under controlled conditions.Botryococcus braunii is the most promising organism favored for bio-fuels as 86% of their dry cell mass is long chain hydrocarbons. In place of bio-fuels from food sources, Algae based bio-fuels make much more sense because of higher productivity. The annual yield per hectare can be as high as 100000 liters of bio-fuel compared to only 1413 liters(L) from Castor, 952 L from Sunflower, 779 L from Safflower, 5950 L from Palm, 446 L from Soy or 2689 L from Coconut. There are a number of global projects trying to mass produce Algae to make it a viable proposition. Large Photobioreactors are being designed using artificial light with specific wave length spectrum ideal for optimal growth. In a typical such reactor of capacity 200 L, yield of 140 g has been reported and still it is a long way before efficient large scale reactors become operational. Hybrid systems combining open pond cultivation and photoreactor modules are also being developed, ultimate aim being higher productivity and lower production cost. Algae species rich in oil include Scenedesmus dimorphis (16-40% lipids), Spirogyra sp (33-64% lipids), and Prymnesium parvum (22-38% lipids). Oil yield can be maximized by manipulating the growing conditions, especially the medium composition.
Single Cell Proteins (SCP) was once a prime candidate for meeting the world wide protein malnutrition during nineteen fifties and sixties and Algae fitted the bill admirably well. Species like Scenedesmus obliquus (50-56% protein), Chlorella vulgaris (51-58% protein, Spirulina platinsis (46-63% protein) and Euglina gracilis (39-61% protein) are useful as protein sources. However, high nucleic acid content in some species, as high as 6%, poses problems for use of Algae for edible purpose unless properly processed. Some of the nutraceutical components from Algae include Phycocyanins for defense against oxy radicals, beta carotene for antioxidant defense, Zeaxanthi/Lutin for good eye health, Gamma Linolenic Acid as essential fatty acid and some like calcium spirulan, sulfolipids and glycolipids still being investigated for their health protection role. Algae like Nanno chloropsis and Chlorella vulgaris are priced at about $ 18000-36000 per ton in the market and a $ 27 billion sports nutrition industry makes use of these material for various formulations.
It is time that global efforts and intensified, as is happening in the sustainable energy area, for evolving universally accessible technologies in Algal cultivation for the benefit of people in poor as well as the rich countries of the world. Vast ocean spread, this planet is blessed with, must be utilized to produce algae under controlled conditions, similar to the off shore drilling projects with well designed infrastructure, working to exploit the ocean bed for fossil fuels. This tiny organism, if harnessed collectively, has the potential to dramatically change the face of the world for better, by providing an inexhaustible source of food, feed, fertilizer, fuel and health promoting chemicals in unlimited quantities, for centuries to come..