[Penicillium chrysogenum mycelial productivity in the 1st phase of penicillin biosynthesis]

The course of the mycelium low productivity during the first phase of the usual two-stage process of penicillin biosynthesis was studied. It was found that the low productivity of the mycelium at the beginning of the fermentation process was probably associated with catabolic regression of the penicillin-producing system. The high specific growth rate registered in the experiments (0.06-0.08 hours-1) had no negative effect on the mycelium productivity. It was not possible to connect the productivity level with the mycelium age, because young and mature mycelium had the same producitivity levels at any developmental stage under the same conditions.