Dilute acid treatment is the best method suited for this purpose: in this method, most of xylose fraction is recovered in the liquid fraction after pretreatment while glucan remains in the solid fraction [5–7]. After the acid pretreatment, the solid cellulose-rich fraction is processed via enzymatic saccharification and fermentation to producing ethanol. The xylose monomers in the hydrolysate, on the other hand, can take a separate pathway and serve as substrate for the cultivation of oil-producing yeasts, producing lipid and then ultimately biodiesel. Since the oleaginous microbes require carbon sources for the growth and lipid production, the xylose can contribute to the improvement of economic viability of the biodiesel production, particularly in heterotrophic cultivation