The Production and Selection of a Family of Strains in Penicillium Chrysogenum

Proteomics Shows New Faces for the Old Penicillin ProducerPenicillium chrysogenum

“…It was tested in 300-liter fermentors, yielding over 550  μ g/mL (900 i.u./mL) [27]. This strain represents the origin of the Wisconsin family of superior strains, some producing over 1800  μ g/mL (3000 i.u./mL) [28]. After ultraviolet mutagenesis of strain Q-176, the pigmentless strain BL3-D10 was obtained.…”

“…This was desirable due to commercial purposes, since extraction of the yellow pigment produced naturally by P. chrysogenum gave rise to antibiotic losses during the purification process. Therefore, this strain was selected to produce directly the white commercial product although it involved a 25% reduction in penicillin yield [28]. The BL3-D10 strain was subjected to successive colony selection rounds without mutagenesis to stabilize the mutant strains.…”

The Isolation, Preservation and Improvement of Industrially Important Micro-organisms

“…As discussed in Chapter 6, the morphology of a fungus in submerged culture may be controlled by the level of a spore inoculum and by the medium, but it is also possible to influence the organism's morphology by altering its genotype. Backus and Stauffer (1955) recognized the influence of the genetics of a strain on the morphology of P. chrysogenum in submerged culture and its role in controlling foaming and broth filtration characteristics. Bartholomew et al (1977) selected strains of P. chrysogenum (for penicillin production) which gave a lower viscosity broth which increased the oxygen-transport ability of their fermentation plant equipment.…”

“…Thus, in these circumstances it would be an advantage to alter the strain such that the undesirable product is no longer produced. An example in the penicillin-producing strains is the elimination of the production of the yellow pigment, chrysogenein, by the selection of non-pigmented mutants which made the extraction of the antibiotic much simpler (Backus and Stauffer, 1955). Dolezilova et al (1965) considered the production of fungicidin (nystatin) and cycloheximide by mutants of S. noursei.…”

Induction of Gliotoxin Secretion in Aspergillus fumigatus by Bacteria-Associated Molecules

“…This problem was solved by the discovery of P. chrysogenum , which has much higher levels of constitutive penicillin production. Laborious mutation and selection efforts eventually yielded a P. chrysogenum strain whose penicillin output exceeded that of Fleming’s mold by a factor of 1000 [3].…”