Identification of a lys2 mutant of Candida maltosa by means of transformation.

We have isolated five mutants of Candida maltos, which lack the 2-aminoadipate reductase activity, an enzyme involved in the lysine biosynthesis. By means of complementation analysis using protoplast fusion, the isolated mutants were divided into two complementation groups. Thereof the C. maltosa strain G457 could be transformed by the plasmids pDP12 and pDP13, which contain the LYS2-coding gene of Saccharomyces cerevisiae. On the basis of our presented results obtained by studies on hybridization, stability, and recovery of plasmids from C. maltosa transformants, we suggest that transformation does proceed integratively.