Cloning, sequence analysis and expression of bacterial lipase-coding DNA fragments from environment in Escherichia coli.

Abstract  Thirteen pairs of primers were designed, synthesized and used to clone the whole coding sequences or mature peptide-coding sequences of lipases. Bacteria producing extracellular lipases were enriched for the extraction of total DNAs. Eight fragments with 500–1,200 bp in length were obtained by using touchdown PCR and sequenced. Five of them were found to be lipase-coding DNAs. One fragment called BL9 that was 95.9% similar to a coding sequence of putative lipase. This lipase contained a Gly-His-Ser-Met-Gly motif which is matched to the consensus Gly-X-Ser-X-Gly conserved among lipolytic enzymes. The BL9 DNA fragment was inserted into the expression vector pET32a(+) of Escherichia coli. A functional product was yielded in the supernatant and produced a hydrolyzed zone on the tributyrin agar. [ABSTRACT FROM AUTHOR]