Protoplast production and transformation of morphological mutants of the Quorn 2 myco - protein fungus , Fusarium graminearum A 3 / 5 , using the hygromycin B resistance plasmid pAN 7 - 1

A protocol for the generation of high yields of viable protoplasts has been developed for several highly branched (colonial) strains of the Quorn2 myco-protein fungus, Fusarium graminearum A3}5. Driselase was found to produce higher protoplast yields (ca 10* g−" wet weight) than the other lytic enzymes tested (Glucanex, Novozyme, β-glucuronidase, Sigma lytic enzyme, or ICN lytic enzyme), although yields differed for the various strains. Protoplast regeneration frequencies of 25–50% were observed when glucose (1±0 ) or sucrose (1±0 ) was used as the osmotic stabilizer. A highly branched strain of F. graminearum CC1-5, which grows better in submerged culture than the more sparsely branched wild-type strain (A3}5) was transformed using the hygromycin B resistance plasmid pAN7-1.