Alessandra Machado Baron

An efficient system for catalyzing ester synthesis using a lipase from a newly isolated Burkholderia cepacia strain

The synthesis of ethyl-oleate by the lipase from the newly isolated strain Burkholderia cepacia LTEB11 in three different systems has been studied – immobilization on a hydrophobic support (Accurel EP 100®), encapsulation in reverse micelles, and direct addition of powdered free enzyme to the reaction medium. The immobilized enzyme performed best, giving a 70% ester yield in 10 h, this yield being five-fold greater than that obtained for reversed micelles, and two and a half times greater than that obtained for direct addition. An increase in the amount of immobilized enzyme preparation added gave a 100% ester yield in 3 h. The immobilized preparation was quite stable, giving a 100% yield of ethyl-oleate during 11 repeated reactions, and 50% yield after 24 reactions. These results suggest that the lipase of our strain of B. cepacia LTEB11 immobilized on Accurel has good potential for application in biocatalysis in organic media.

SPIL: Simultaneous production and immobilization of lipase from Burkholderia cepacia LTEB11

Abstract We describe a method that we have called SPIL, the ‘simultaneous production and immobilization of lipases’. In this method the lipase of Burkholderia cepacia LTEB11 was immobilized by addition of Accurel EP 100 to the growth medium during culture. A factorially designed experiment was undertaken to optimize the activity adsorbed on the support, with variables being the time of addition of Accurel (0–24 h), the concentration of Accurel (10–30 g L−1) and the concentration of olive oil (0.25–1.0%, v/v). The highest activity loading, of 2600 units of p-nitrophenyl palmitate-hydrolyzing activity per gram of support, was obtained by the addition of 10 g Accurel L−1 at 12 h to a medium containing 1% (v/v) olive oil. This preparation gave threefold higher rates for the esterification of ethyl oleate in n-heptane than did a preparation obtained through the conventional practice of adding Accurel at the end of the fermentation, with a conversion of 95% being attained in 1 h.