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Considering the extraordinary microbial diversity and importance of fungi as enzyme producers, the search for new biocatalysts with special characteristics and possible applications in biocatalysis is of great interest. Here, we report the performance in the resolution of racemic ibuprofen of a native enantioselective lipase from Aspergillus niger, free and immobilized in five types of support (Accurel EP-100, Amberlite MB-1, Celite, Montmorillonite K10 and Silica gel). Amberlite MB-1 was found to be the best support, with a conversion of 38.2%, enantiomeric excess of 50.7% and enantiomeric ratio (E value) of 19 in 72 h of reaction. After a thorough optimization of several parameters, the E value of the immobilized Aspergillus niger lipase was increased (E = 23) in a shorter reaction period (48 h) at 35 degrees C. Moreover, the immobilized Aspergillus niger lipase maintained an esterification activity of at least 80% after 8 months of storage at 4 degrees C and could be reused at least six times.

Resolution of (R,S)-ibuprofen (2-(4-isobutylphenyl)propionic acid) enantiomers by esterification reaction with 1-propanol in different organic solvents was studied using native Aspergillus niger lipase. The main variables controlling the process (enzyme concentration and 1-propanol:ibuprofen molar ratio) have been optimized using response surface methodology based on a five-level, two-variable central composite rotatable design, in which the selected objective function was enantioselectivity. This enzyme preparation showed preferentially catalyzes the esterification of R(-)-ibuprofen, and under optimum conditions (7% w/v of enzyme and molar ratio of 2.41:1) the enantiomeric excess of active S(+)-ibuprofen and total conversion values were 79.1 and 48.0%, respectively, and the E-value was 32, after 168 h of reaction in isooctane.