Impact of Classical Strain Improvement of Penicillium rubens on Amino Acid Metabolism during β-Lactam Production

Abstract

Penicillium rubens is an important industrial producer of β-lactam antibiotics. High levels of penicillin production were enforced through extensive mutagenesis during a classical strain improvement (CSI) program over 70 years. Several mutations targeted amino acid metabolism and resulted in enhanced l -cysteine biosynthesis. This work provides a molecular explanation for the interrelation between secondary metabolite production and amino acid metabolism and how classical strain improvement has resulted in improved production strains.