TRANSFORMATION SYSTEM FOR ASPERGILLUS-ORYZAE WITH DOUBLE AUXOTROPHIC MUTATIONS, NIAD AND SC

We developed a transformation system for Aspergillus oryzae using the Aspergillus nidulans sC gene encoding ATP sulfurylase as a selectable marker, The sC(-) mutants can be readily isolated by positive selectio n for selenate resistance, thereby the niaD(-) mutant strain of A. ory zae was bestowed with the sC(-) mutation, Transformation of the A. ory zae host (niaD(-), sC(-)) with the plasmid carrying A. midulans sC gav e random and multi-copy integrants, while that with the A. oryzae niaD (-) carrying plasmid occurred mainly by single-copy and homologous int egration events (more than 50% frequency), indicating that with this t ransformation system, the transformation marker could be selected acco rding to the integration pattern one desires.