Intraspecific, interspecific, and intergeneric recombination in ?-lactam producing fungi via protoplast fusion

Abstract

Five β-lactam producing fungi were selected to elaborate techniques for parasexual recombination with respect to a transgression of the species and genus limits. 1. These fungi, obtained from strain collections, were reclassified according to the morphological properties and in using biochemical methods as: Emericellopsis glabra, Emericellopsis salmosynnemata, Cephalosporium acremonium, Cephalosporium spec., and Paecilomyces carneus. 2. Techniques were developped to produce variants as genetic markers and heterokaryons via protoplast fusion. 3. It was possible to obtain parasexual recombinants of the marker genes not only in intraspecific but also in interspecific and intergeneric crosses. However, the number of recombinants decreased from 10−4 via 5 · 10−5 to 10−5 with increasing taxonomic diversity. 4. Mophological characters, such as conidiation and to a certain extent also the ability to produce antibiotics, may be transferred via protoplast fusion and subsequent parasexual recombination. It becomes obvious that this technique may be used for strain improvement in Biotechnology.