GENETIC-TRANSFORMATION OF ASTAXANTHIN MUTANTS OF PHAFFIA-RHODOZYMA

Stable red astaxanthin-producing transformants were obtained after gen etic transformation of two Phaffia rhodozyma mutants. A yellow mutant, accumulating beta-carotene, and an albino mutant, accumulating phytoe ne, from P. rhodozyma were transformed using a genomic library of wild -type strain UCD 67-385 in the pBluescript vector. Hybridization assay s, using the pBluescript DNA as a radioactive probe, indicate integrat ion of vector sequences into the genome of the transformants. Transfor mants DNA was digested with restriction endonucleases, ligated with T4 DNA ligase and then used to transform E. coli. Ampicillin resistant p lasmids, containing 0.1, 0.2, and 2.5 kb DNA inserts of P. rhodozyma, were rescued from the yeast red transformants. The molecular analysis indicate that transformation has occurred by an integration event of d onor DNA into the genome of the host strains.