An unstructured model has been used to predict microbial growth based on glycerol consumption and poly-ε-lysine (ε-PL) biosynthesis by Streptomyces noursei NRRL 5126. The logistic and Luedeking-Piret equations have been proposed to describe the time course of ε-PL formation, substrate consumption and cell growth. The shake flask level data from kinetic studies was illustrated and compared with fermenter studies. In all cases, the model simulation matched well with the experimental observations, which made it possible to elucidate the fermentation characteristics of Streptomyces noursei during efficient ε-PL production from glycerol. Optimized oxygen supply into the fermenter shifted mixed growth associated biosynthesis of ε-PL from shake flask level to growth associated biosynthesis.