An enzymatic transesterification pathway is a biocatalytic reaction using biocatalyst (i. e., lipase enzyme) for biodiesel production (Fig. 10.3). This biochemical approach is able to resolve downstream processing problem that posed by chemical
transesterification (homogeneous and heterogeneous catalyzed reaction). The bio­diesel and glycerol purification steps in chemical reaction will generate huge amount of waste water that eventually increase biodiesel production cost. In contrast, bio­processing of oil via enzymatic reaction for biodiesel production is being simpler, milder reaction condition, lower energy process, less corrosive, and able to simulta­neously catalyze transesterification and esterification in a single-step process with the presence of high FFA oil. However, the enzyme-catalyzed reaction is not sug­gested to be commercially developed due to its higher cost of lipase with its feasibility aspect, and the duration for reaction is still unfavorable compared to chemical reaction.