Kinetics of Continuous Hydrolysis of Olive Oil by Lipase in Microporous Hydrophobic Membrane Bioreactor

On the performance of a hollow-fiber bioreactor for acidolysis catalyzed by immobilized lipase

“…Therefore, the active conformation of the experimental lipase used might have been reached and locked when physical adsorption onto the hydrophobic matrix occurred (Giorno et al, 1995;Reetz, 1997;Yamane et al, 1986), thus explaining the enhancement in activity which was actually noticed; positive effects of higher water activity cannot be claimed in our case, owing to the hydrophobic nature of the membrane. Alternatively, because the adsorption process may also be considered as a purification step when crude enzyme mixtures containing lipase are used (Malcata et al, 1992a,b,c), as claimed before, selective immobilization of lipase relative to the overall protein inventory of the crude commercial lipase powder may also partially account for the putative hyperactivation.…”

Kinetics and mechanisms of reactions catalyzed by immobilized lipases☆

“…However, activation is not restricted to water/lipid interfaces; extensive evidence of activation of a lipase from Mucor javanicus upon adsorption onto such hydrophobic carriers as octyl-agarose gels [38] and polypropylene hollow-fibers [10] supports postulated hypotheses that lipases can recognize a hydrophobic/hydrophilic interface irrespective of its nature, and that exposure of the big hydrophobic pocket around the active center to substrate occurs as if a classical water/oil interface were present. Such active conformation of lipase might have been duly locked when physical adsorption onto the hydrophobic matrix did extensively occur [32,68,92], as discussed in the previous subsection.…”

“…from Mucor javanicus) occurs upon adsorption onto hydrophobic supports possessing large specific surface area [10,38]; this is in agreement with the postulated hypothesis that lipases recognize such well-defined hydrophobic supports as solid intefaces, and may thus become adsorbed via the external surfaces of the big hydrophobic pocket around the active center of their open and activated structure [38], without involving the active site itself. In this way, the active conformation of the lipases may be locked when physical adsorption onto the hydrophobic matrix occurs [32,68,92], thus providing a rationale for the enhancement in activity usually noticed.…”

Hydrolysis of olive oil using lipase bonded to modified carbon membrane

“…The p K a value is about 5 for fatty acids, which are assumed to be completely ionized. Furthermore, the highly nucleophilic OH − ion combines irreversibly with the carbonyl group (COOH) of fatty acid to form the resonance‐stabilized COO − ions 23‐27. Because the applied pressure is very small, only diffusion resistance to the mass transfer exists.…”