Yeast HXK2 gene reverts glucose regulation mutation of penicillin biosynthesis in P. chrysogenum

Abstract

The mutant Penicillium chrysogenum strain dogR5, derived from strain AS-P-78, does not respond to glucose regulation of penicillin biosynthesis and β-galactosidase, and is partially deficient in D-glucose phosphorilating activity. We have transformed strain dogR5 with the (hexokinase) hxk2 gene from Saccharomyces cerevisiae. Transformants recovered glucose control of penicillin biosynthesis in different degrees, and acquired a hexokinase (fructose phosphorylating) activity absent in strains AS- P-78 and dogR5. Interestingly, they also recovered glucose regulation of β-galactosidase. On the other hand, glucokinase activity was affected in different ways in the transformants; one of which showed a lower activity than the parental dogR5, but normal glucose regulation of penicillin biosynthesis. Our results show that Penicillium chrysogenum AS-P-78 and dogR5 strains lack hexokinase, and suggest that an enzyme with glucokinase activity is involved in glucose regulation of penicillin biosynthesis and β-galactosidase, thus signaling glucose in both primary and secondary metabolism; however, catalytic and signaling activities seem to be independent.

Pcz1 regulates growth, conidiation, conidial germination, and production of penicillin in the filamentous fungus Penicillium rubens (formerly Penicillium chrysogenum)

“…For the production of benzylpenicillin, P. rubens was grown on Power medium agar (Fierro et al 1996) at 28°C for 5 days. All the spores of a plate were collected and inoculated into 50 mL of the MCIP liquid medium (Pérez et al 2014). The culture was incubated at 25°C and 250 rpm for 24 hours.…”

“…The culture was incubated at 25°C and 250 rpm for 24 hours. After that, 10 mL of the culture were taken and inoculated into 100 mL of the MCFP medium (Pérez et al 2014) and incubated under the same conditions at 72 and 96 hrs. The extraction of benzylpenicillin from these broths and its quanti cation were done as described by García-Estrada et al (2007).…”