CHARACTERIZATION OF THE CANDIDA-RUGOSA LIPASE SYSTEM AND OVEREXPRESSION OF THE LIP1 ISOENZYME IN A NONCONVENTIONAL YEAST

The fungus C. rugosa produces lipase isoenzymes (CRLs) homologous to t he Geotrichum candidum and Yarrowia lipolytica lipases to which they s hare ca. 40 and 30% sequence identity, with a domain of sequence conse rvation at the N-terminal half of the protein. CRL proteins have high sequence homology but are not identical in their catalytic activity, t herefore calling for the resolution of isoforms via heterologous expre ssion. The non-conventional use of a serine codon in several Candida s pecies frustrates overexpression in the currently available host syste ms. The LIP1 gene, coding for the major CRL form, was therefore expres sed in C. maltosa, a related fungus with the same codon usage as C. ru gosa. A recombinant lipase was produced and secreted in an active form in the culture medium upon engineering the 5' and 3' ends of the gene . (C) 1998 Published by Elsevier Science Ireland Ltd. All rights reser ved.