A protocol for the generation of high yields of viable protoplasts
been developed for several highly branched (colonial) strains
of the Quorn® myco-protein fungus, Fusarium graminearum A3/5.
Driselase was found to produce higher protoplast yields
(ca 109 g−1
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 M) or sucrose (1·0 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.