Protoplast production and transformation of morphological mutants of the Quorn registered myco-protein fungus, Fusarium graminearum A3/5, using the hygromycin B resistance plasmid pAN7-1

A protocol for the generation of high yields of viable protoplasts has been developed for several highly branched (colonial) strains of the Quorn registered myco-protein fungus, Fusarium graminearum A3/5. Driselase was found to produce higher protoplast yields (ca 10 super(9) g super(-1) wet weight) than the other lytic enzymes tested (Glucanex, Novozyme, beta -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 times 0 M) or sucrose (1 times 0 M) 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.