TRANSFORMATIONS OF PENICILLIUM-ISLANDICUM AND PENICILLIUM-FREQUENTANSTHAT PRODUCE ANTHRAQUINONE-RELATED COMPOUNDS

Wild-type strains of Penicillium islandicum and Penicillium frequentan s, which produce anthraquinone and related compounds, were transformed to benomyl and hygromycin B resistance. Plasmids pSV50 and pBT6, with benomyl-resistant beta-tublin genes, and plasmids pAN7-1 and pDH25, w ith a bacterial hygromycin phosphotransferase gene under the control o f Aspergillus nidulans sequences, were used respectively. Transformati on frequencies with these plasmids were 10-20 transformants per mu g o f DNA per 4-8 x 10(7) viable protoplasts. Integration of plasmid DNAs into chromosomal DNAs was confirmed by Southern-blot analysis. Copy nu mbers and sites of integration varied among transformants. The integra ted plasmid DNAs conferring a drug-resistant phenotype were mitoticall y stable with or without selection. The demonstration of such transfor mation systems is the essential first step in the application of recom binant DNA technology to study the biosynthetic genes of anthraquinone and related compounds in P. islandicum and P. frequentans.