The development of a heterologous transformation system for the cellulolytic fungus Trichoderma reesei based on a pyrG-negative mutant strain.
Six uridine auxotroph mutants of Trichoderma reesei QM 9414 were isolated by resistance to 5-fluoroorotic acid and one strain was identified as OMP-decarboxylase negative (pyr-) by a radiometric enzyme assay. Transformation to uridine prototrophy was achieved with the pyr4 gene of Neurospora crassa (up to 1500 transformants/micrograms) and with pyrA of Aspergillus niger (700-800 transformants/micrograms). In many transformants the PYR+ function seems to be present as extrachromosomal DNA. There is evidence for a correlation between the stability of transformants and integration of the vector in the genome whereas unstable transformants are obtained when autonomous replication of the plasmid occurs.
Gruber
F
F
Abt. Mikrobielle Biochemie, Institut für Biochemische Technologie und Mikrobiologie, TU Wien, Austria.
Visser
J
J
Kubicek
C P
CP
de Graaff
L H
LH
D015139:Blotting, Southern; D002855:Chromatography, Thin Layer; D004352:Drug Resistance, Microbial / Q000235:genetics; D005800:Genes, Fungal; D009154:Mutation; D009963:Orotic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D009964:Orotidine-5'-Phosphate Decarboxylase / Q000172:deficiency* / Q000235:genetics; D014170:Transformation, Genetic; D014242:Trichoderma / Q000235:genetics* / Q000302:isolation & purification; D014529:Uridine / Q000378:metabolism
D009963:Orotic Acid; C001242:5-fluoroorotic acid; D009964:Orotidine-5'-Phosphate Decarboxylase; D014529:Uridine