Transesterification activity of a mycelium-bound lipase from Aspergillus niger MYA 135

ROMERO C; PERA, LICIA M; BAIGORI M.D

Rosario. Santa Fe, Argentina.

Congreso; SAIB 42 th Annual Meeting. XLII Reunión Anual; 2006

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

Introduction: Lipases (EC 3.1.1.3) can be used for the synthesis of esters by transesterification with acyl donors in organic solvents. These enzymes have moved far from their original application to the biotechnological processing of fat and other lipids. Transesterification is especially useful for the preparation of optically active compounds, which are formed by resolution or asymmetrization of racemic or prochiral suitable substrate. The aim of this work was to determine the transesterification activity of a mycelium-bound lipase from Aspergillus niger MYA 135. Methods: Enzymatic transesterifications were performed in nhexano using p-nitrophenyl palmitate and the assayed alcohol as substrates. Mycelium-bound lipase was directly used as a source of lipase. The released p-nitrophenol was extracted with Na2CO3Aspergillus niger MYA 135. Methods: Enzymatic transesterifications were performed in nhexano using p-nitrophenyl palmitate and the assayed alcohol as substrates. Mycelium-bound lipase was directly used as a source of lipase. The released p-nitrophenol was extracted with Na2CO3p-nitrophenol was extracted with Na2CO3 before measurement at 405 nm. Reaction mixtures without the assayed alcohol were used as a hydrolysis control. Qualitative analyses of alkylpalmitates were done by thin layer chromatography using chloroform as developing solvent. Result and Conclusion: Under our experimental conditions methyl, ethyl, propyl, buthyl, hexyl and hepthyl palmitate were synthesized. The higher specific transesterification activity (mU per g of dry weight) was observed in presence of hexanol (60.8 ± 1.2 mU/g). This work was supported by grants PICTO 761 and PIP 6062