Similarly, Δ12 desaturase works between carbon 12 and carbon 13 while Δ15 desaturase works between carbon 15 and carbon 16. After completion of the reactions, the fatty acid (stearic acid) will be converted into ALA (Figure 1). When ALA is released from E. coli and absorbed by human cells, ALA will be further converted into docosahexaenoic acid, DHA. Since human cells contain genes encoding the remaining desaturases and elongases that are necessary for the conversion of ALA into
DHA (Innis, 2007), which is our final target product.