A comparative study of the synthesis of n-butyl-oleate using a crude lipolytic extract of Penicillum coryophilum in water-restricted environments

We evaluated the potential of a lipolytic extract from Penicillium corylophilum for use in biocatalysis. Lipolytic activity was stable when the extract was incubated in the presence of hydrophobic solvents. In fact, when the extract was incubated in n-heptane with an initial water activity of 0.95, the activity increased by 30%. Synthesis of n-butyl-oleate in different systems was compared. In AOT/n-heptane reverse micelles, a 100% yield of ester was obtained within 12 h, with a water content (W0, [H2O]/[AOT]) of 10. Several macro-heterogeneous systems involving n-heptane as the solvent were also compared. Direct addition of lyophilised enzymatic preparation to this system gave a 100% yield in 48 h, with an initial water activity of 0.11. Performance was poorer with direct addition of enzymatic preparation co-lyophilised with β-cyclodextrin and with addition of enzymatic preparation immobilized on a hydrophobic gel, with yields significantly less than 100%. We conclude that the lipolytic extract of P. corylophilum can be used in synthesis reactions in low-water systems, which justifies further efforts to purify lipolytic enzymes from the extract and to undertake an in-depth evaluation of their potential for use in biocatalysis, for the production of fine chemicals.