Abstract
This chapter examines the lipid and fatty acid composition of some marine and freshwater microalgae species. We also report some general growth conditions that can be modulated during algal growth for maximum lipid production. Some relevant works in the field of lipid extraction at laboratory scale are summarized, including chemically organic solvents, supercritical methods, and ionic liquids. The algal lipid extracted by organic solvents can be converted into biodiesel through a process similar to that used for any other vegetable oil. Alternatively, supercritical fluid extraction can be used to extract polyunsaturated fatty acids with food grade appeal. The choice of the extraction method will determine the final utilization of lipid and fatty acids towards food and feed application or biodiesel production.