Lysine regulation of penicillin biosynthesis in low-producing and industrial strains of Penicillium chrysogenum.

The inhibitory effect of L-lysine on penicillin biosynthesis by Penicillium chrysogenum has been compared in a low-producing strain (Wis. 54-1255) and a high-producing strain (ASP-78). Lysine inhibited total penicillin synthesis to a similar extent in both strains. However, in the high-producing strain the onset of penicillin synthesis occurred even at a high lysine concentration, whereas in the low-producing strain lysine had to be depleted before penicillin production commenced.