ISOLATION OF URACIL AUXOTROPHIC MUTANTS OF TRICHODERMA-HARZIANUM AND THEIR TRANSFORMATION WITH HETEROLOGOUS VECTORS

Nine uracil auxotrophic mutants were isolated from a mycoparasitic str ain of Trichoderma harzianum. One of these could be transformed with t he pKIM7 cosmid, which contained the pyr-4 gene of Neurospora crassa. Another uracil-requiring mutant was transformed with heterologous vect ors containing the orotate pyrophosphoribosyl transferase genes of Pod ospora anserina and Trichoderma reesei. The transformation frequencies varied between 150 and 1000 mu g(-1) plasmid DNA. Hybridization analy sis of the transformants revealed distinct locations of integrated vec tors in the genomes, but in some transformants freely replicating plas mids could also be detected.