INVESTIGADORES
LOTO Flavia Del Valle
artículos
Título:
Specific enzyme-catalyzed hydrolysis and synthesis in aqueous and organic medium using biocatalysts with lipase activity from Aspergillus niger MYA 135
Autor/es:
CINTIA ROMERO; LICIA PERA; FLAVIA LOTO; MARIO BAIGORI
Revista:
CATALYSIS LETTERS
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 2012 p. 25 - 31
ISSN:
1011-372X
Resumen:
In the present study, the specific hydrolyticactivity of three biocatalysts such as the constitutivemycelium-bound lipase, the induced mycelium-boundlipase and the lyophilized induced supernatant fromA. niger MYA 135 was evaluated in both aqueous andorganic media.A direct correlation between activity in waterand n-hexane was not observed for the same hydrolyticreaction. The n-hexane/water activity ratio (RO/A) wasapplied to characterize the activity in organic medium. Thethree biocatalysts showed RO/A values higher than 1 forhydrolysis of long-chain fatty acid esters, demonstrating ahigher specific hydrolytic activity in organic solvent than inwater. A different behavior was observed during hydrolysisof middle-chain fatty acid esters, which was higher inaqueous medium (RO/A\1). Transesterifications of differentalcohols with various p-nitrophenyl derivatives using allthree biocatalysts preparations were also evaluated in nhexane.For methanolysis and ethanolysis, the constitutivemycelium-bound lipase displayed an interesting preferencefor C16 substrate (p-nitrophenyl palmitate). The inducedmycelium-bound lipase showed high specific transesterificationactivities in the presence of water-miscible alcoholsand middle-chain fatty acid esters (p-nitrophenyl caprate andp-nitrophenyl laurate), being the highest specific transesterificationactivity (91.4 ± 1.7 mU/gdw) observed in a reactionmixture containing propanol and p-nitrophenyl laurate.Finally, both p-nitrophenyl caprate (C10) and p-nitrophenyllaurate (C12) were preferentially methanolized by the lyophilized induced supernatant, being this lipase activitythe most specific biocatalyst preparation under transesterificationconditions. A selectivity-based analysis of eachlipase preparation toward transesterification or hydrolysis inorganic medium was evaluated as well.