What nickname was given to the high-yield NRRL 1951 mould strain?

The high-yield NRRL 1951 mould strain was nicknamed the cantaloupe strain.

In 1943, researchers searching for a better penicillin-producing mould examined samples from around the world. The most productive sample came from a mouldy cantaloupe bought at a fruit market in Peoria, Illinois. The mould was identified as Penicillium chrysogenum and entered the Northern Regional Research Laboratory collection as NRRL 1951.

NRRL 1951 was valuable because it produced substantially more penicillin than Fleming’s original strain and worked well with developing industrial fermentation methods. Researchers then used radiation to create still more productive mutants, including X-1612. Later improvements helped make large-scale penicillin manufacture practical during World War II.

“Moyer strain,” “Peoria blue,” and “Oxford strain” may sound plausible because Moyer worked on production and Peoria was central to the research, but they are not the standard nickname for NRRL 1951.