title: Lipases immobilization for effective synthesis of biodiesel starting from coffee waste oils.
abstract: Immobilized lipases were applied to the enzymatic conversion of oils from spent coffee ground into biodiesel. Two lipases were selected for the study because of their conformational behavior analysed by Molecular Dynamics (MD) simulations taking into account that immobilization conditions affect conformational behavior of the lipases and ultimately, their efficiency upon immobilization. The enzymatic synthesis of biodiesel was initially carried out on a model substrate (triolein) in order to select the most promising immobilized biocatalysts. The results indicate that oils can be converted quantitatively within hours. The role of the nature of the immobilization support emerged as a key factor affecting reaction rate, most probably because of partition and mass transfer barriers occurring with hydrophilic solid supports. Finally, oil from spent coffee ground was transformed into biodiesel with yields ranging from 55% to 72%. The synthesis is of particular interest in the perspective of developing sustainable processes for the production of bio-fuels from food wastes and renewable materials. The enzymatic synthesis of biodiesel is carried out under mild conditions, with stoichiometric amounts of substrates (oil and methanol) and the removal of free fatty acids is not required.
authors: Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Trieste, Piazzale Europa 1, Trieste 34127, Italy. vferrario@units.it.
authors: Valerio
authors: V
authors: Ferrario
authors: Department of Chemical Engineering, Faculty of Engineering, University of Malaya, Malaysia. my_harumi@yahoo.com.
authors: Harumi
authors: H
authors: Veny
authors: Flavia 110, Trieste 34147, Italy. elisabetta.deangelis@illy.com.
authors: Elisabetta
authors: E
authors: De Angelis
authors: Flavia 110, Trieste 34147, Italy. luciano.navarini@illy.com.
authors: Luciano
authors: L
authors: Navarini
authors: Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Trieste, Piazzale Europa 1, Trieste 34127, Italy. ebert@units.it.
authors: Cynthia
authors: C
authors: Ebert
authors: Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Trieste, Piazzale Europa 1, Trieste 34127, Italy. gardossi@units.it.
authors: Lucia
authors: L
authors: Gardossi