Hydrolytic activity of immobilized ABL was analyzed using
palm oil as a substrate over pH and temperature ranges of
3.0–13.0 (37 1C) and 20–80 1C (pH 9.0), respectively, to identify
favorable conditions for the lipase reaction. Buffer systems were
acetate (pH 3.0–5.0), phosphate (pH 6.0–7.0), Tris–HCl (pH 7.0–9.0)
and carbonate (pH 9.0–13.0). For solvent stability, immobilized
ABL was mixed with an equal volume of each selected organic
solvent to prepare the 50% organic solution. Mixtures were shaken
and incubated at 37 1C for 6 h at 150 rpm. The solvent contained in
the mixture was partially eliminated by evaporation at 37 1C for
5 min. Residual lipase activity was measured at 37 1C and pH
9.0 and compared to that of the control (no solvent).