Recombinant oleaginous alga that include one or more heterologous genes that increase the ability of the alga to use one or more natural saccharides such as cellulosic or hemicellulosic sugars for algal growth are described. The recombinant oleaginous algae are transformed to include one or more genes expressing sugar metabolizing enzymes or sugar transporting proteins, along with suitable control elements. Use of natural saccharides as a carbon source can allow the algae to produce biofuel precursors in a relatively efficient manner. Processes for preparing the alga, growing the alga, and extracting the biofuel precursors from the alga are also described.