Malachite green treatment of industrial Penicillium chrysogenum protoplasts results in increased penicillin-V formation

We attempted protoplast fusion in order to generate gene transfer between a n industrial strain of Penicillium chrysogenum and a fission yeast, Schizos accharomyces pombe. The Penicillium strain was treated with malachite green . The S. pombe strain was auxotrophic for lysine. The regenerated colonies showed Penicillium morphology. The number of Penicillium colonies was signi ficantly higher when the inactivated Penicillium protoplasts were fused to S. pombe protoplasts than in the self-fusion control experiments. We random ly isolated colonies from the regeneration plates and measured beta-lactam formation in cultures from shaken flasks. Antibiotic production was increas ed in colonies originated from the malachite green-treated protoplasts.