Novel microbial lipases: catalytic activity in reactions in organic media

2,000 microbial strains were isolated from soil samples and tested to deter mine their lipolytic activity by employing screening techniques on solid an d in liquid media. Culture broths were initially tested with 1,2-O-dilauryl -rac-glycero-3-glutaric acid-resorufinyl ester, a chromogenic substrate spe cific for lipases. Fourteen lipase-producing microorganisms were selected a nd their taxonomic identification was carried out. Hydrolysis of tributyrin or olive oil and the esterification of oleic acid with heptanol were selec ted to preliminary evaluate the catalytic activity of these lipases. All th e selected lipases catalysed this esterification reaction with good yields. Resolution of (R,S)-2-(4-isobutylphenyl) propionic acid, (R,S)-1-phenyleth anol, (R,S) 1-phenylethylamine and of (R) or (S) glycidol were performed to evaluate the stereoselectivity of these novel enzymes as biocatalysts in r eactions in organic media. Lipases from the fungi Fusarium oxysporum and Ov adendron sulphureo-ochraceum gave the best yields and enantioselectivities in the resolution of racemic ibuprofen and 1-phenylethanol, Several lipases displayed a high stereoselectivity in the resolution of chiral amines by a n alcoxycarbonylation reaction. (C) 2001 Elsevier Science Inc. All rights r eserved.