Transformation system for an asporogenous methylotrophic yeast, Candida boidinii: cloning of the orotidine-5'-phosphate decarboxylase gene (URA3), isolation of uracil auxotrophic mutants, and use of the mutants for integrative transformation.

An integrative transformation system was established for an asporogenous methylotrophic yeast, Candida boidinii. This system uses a uracil auxotrophic mutant of C. boidinii as the host strain in combination with its URA3 gene as the selectable marker.