Transformation of the nematode-trapping fungus Arthrobotrys oligospora

The nematode-trapping fungus Arthrobotrys oligospora was transformed to hyg romycin resistance using the hygromycin-B phosphotransferase gene from Esch erichia coil under the control of various heterologous fungal promoters. Pl asmid DNA was introduced into fungal protoplasts by polyethylene glycol/CaC l2 treatment. Transformation frequencies varied between 1-6 transformants p er mu g DNA. Seven out of 13 integration events analyzed from transformants were single copy integrations, whereas the remaining were multiple and mor e complex integrations. The addition of restriction enzymes during transfor mations increased the frequency of single copy integrations. Co-transformat ion, using the E. coli uidA gene encoding the beta-glucuronidase reporter g ene under the control of an Aspergillus nidulans promoter, occurred at freq uencies of up to 63%. (C) 1999 Federation of European Microbiological Socie ties. Published by Elsevier Science B.V. All rights reserved.