SCREENING AND IDENTIFICATION OF A NOVEL LIPASE FROM BURKHOLDERIA SP. YY62 WHICH HYDROLYZES T-BUTYL ESTERS EFFECTIVELY

Fatty acid esters composed of sterically hindered alcohol are very poo r substrates for known lipases. In order to obtain a novel lipase, t-b utyl octanoate (TBO) was selected as a model substrate to screen for b acteria-producing lipase(s) which can preferentially hydrolyze bulky e sters. Of 279 strains isolated from 350 soil samples based an the abil ity to grow with TBO as a sole carbon source, one strain (YY62) was ch osen for its strong TBO-hydrolyzing activity. Strain YY62 is a Gram-ne gative motile rod and was identified as Burkholderia sp. from the taxo nomic characters and phylogenetic analysis of 16S rDNA nucleotide sequ ences. Using the activity ratio between TBO and p-nitrophenyl acetate as a measure for preference to bulky esters, we confirmed that the lip ase of strain YY62 was 100-fold superior to commercial lipases in term s of TBO-hydrolyzing activity.