which is the best species of algae for highest oil content? The decades-long research undertaken by NREL of USA – called the Aquatic Species Program did in-depth research on this topic and in the end, has said that there is no one strain or species of algae that can be said to be the best in terms of oil yield. However they did conclude that the diatoms and secondly green algae were the most promising. The following species listed are currently being studied for their suitability as a mass-oil producing crop, across various locations worldwide: - Neochloris oleoabundans: Neochloris oleoabundans is a microalga belonging in the class Chlorophyceae - Scenedesmus dimorphus: Scenedesmus dimorphus is a unicellular algae in the class Chlorophyceae. While this is one of the preferred species for oil yield, particularly for biodiesel, one of the problems with Scenedesmus is that it's heavy, and forms thick sediments if not kept in constant agitation. - Euglena gracilis - Phaeodactylum tricornutum: Phaeodactylum tricornutum is a diatom - Pleurochrysis carterae: Pleurochrysis carterae is a unicellular coccolithophorid alga that has the ability to calcify subcellularly. It is a member of the class Haptophyta (Prymnesiophyceae) - Prymnesium parvum: Prymnesium parvum is a toxic algae - Tetraselmis chui: Tetraselmis chui is a marine unicellular alga - Tetraselmis suecica - Isochrysis galbana: Isochrysis galbana is a microalga. - Nannochloropsis salina: This is also called Nannochloris oculata. In the same group are Nannochloris atomus Butcher, Nannochloris maculata Butcher, Nannochloropsis gaditana Lubian, and Nannochloropsis oculata (Droop) - Algal strains such as Botryococcus braunii can produce long chain hydrocarbons representing 86% of its dry weight. The green alga Botryococcus is unique in the quality and quantity of the liquid hydrocarbons it produces. Some scientists consider the ancestors of Botryococcus to be responsible for many of the world's fossil fuel deposits. - Dunaliella tertiolecta: This strain is reported to have oil yield of about 37% (organic basis). D. tertiolecta is a fast growing strain and that means it has a high CO2 sequestration rate as well. - Nannochloris sp. - Spirulina species The strains of Algae most favoured by the NREL researchers were Chlorophyceae (green algae). Green algae tend to produce starch, rather than lipids. Green algae have very high growth rates at 30oC and high light in a water solution of type I at 55 mmho/cm. The other favoured algae (by NREL researchers) is Bacilliarophy (diatom algae). However, the diatom algae needs silicon in the water to grow, whereas green algae requires nitrogen to grow. Under nutrient deficiency the algae produced more oils per weight of algae, however the algae growths also were significantly less. While certain green algae strains are very tolerant to temperature fluctuations, diatoms have a fairly narrow temperature range.

Strain Scenedesmus dimorphus Protein 8-18 Carbohydrates 21-52 Lipids 16-40 http://www.fao.org/docrep/w7241e/w7241e0h.htm