Synthesis of biodiesel was carried out through enzymatic biocatalysis by the transesterification of natural
waste olive oil (alperujo oil) using a recombinant 1,3-positional selective Rhizopus oryzae lipase (rROL).
The most relevant property of this uncommon substrate is the high content of free fatty acids (FFAs),
making it impossible to produce biodiesel through basic catalysis. The synthesis reactions were carried
out in a solvent-free media using a covalent immobilisation on a glutaraldehyde-treated polymethacrylate
amino-epoxide carrier. Methanol was added by stepwise addition to avoid lipase inactivation. FFAs
effects on the kinetics, yields and stability of biocatalysts were studied. It was concluded that the high
free fatty acids content allows an increasing on the initial reaction rate and it gives more stability to
the immobilised enzyme, demonstrating the efficiency of this new substrate for the biodiesel production