A PCR method suitable for the isolation of lipase genes directly from environmental DNA is described. The problems associated with the low levels of similarity between lipase genes were overcome by extensive analysis of conserved regions and careful primer design. Using this method, a lipase gene (oli-lipase) was isolated directly from environmental DNA. This lipase showed less than 20% similarity with other known lipases at the amino acid level. The study also revealed that distantly related members of the alpha/beta hydrolase superfamily share similar conserved motifs with the lipases, thus making these genes targets for gene prospecting by PCR.