Fig. 8.

Effect of the addition of different polyamines on growth and penicillin production in liquid cultures of P. chrysogenum. Cultures of P. chrysogenum Wis 54-1255 grown in defined medium were supplemented at inoculation time (0 h) with either 1,3-diaminopropane, putrescine, spermidine, or spermine (5 mM each). The same volume of MilliQ water was added to the control cultures. Samples were taken at 24 h, 48 h, and 72 h. Benzylpenicillin was assessed by HPLC. Relative benzylpenicillin production (%) for each time point was calculated, setting the production that corresponds to the Wis 54-1255 strain at 24 h as 100%.