Keiji Takeuchi

Molecular cloning of lipase genes from alcaligenes dentrificans and their expression in Escheirchia coli

Abstract The lipase genes of Alcaligenes denitrificans TK7 and Pseudomonas aeruginosa OL1 were transferred to Escherichia coli JA2211 using RP4::Mu plasmid. Recombinant clones carrying the foreign lipase (lip) genes had 80 to 115% of the lipase activity of the donor strains of the lip genes. Cloning of the lip genes of A. denitrificans TK7 onto pBR322 revealed two Lip+ recombinant plasmids harboring 15.7 Kb and 4.9 Kb foreign DNA segments, which were designated pYU1 and pYU2, respectively. That these two lip genes originated from A. denitrificans TK7 was demonstrated by Southerns blot analysis. The lip gene of pYU1 was localized within a 1.1 Kb BglII-SalI segment and the lip gene of pYU2 was localized in a 0.8 Kb HpaI-PstI segment. E. coli harboring one of these derivatives produced 16 to 20 times more lipase than did A. denitrificans TK7.