In Silico Quantification of Optimal Lysine Synthesis During Growth of Corynebacterium Glutamicum on Mixed Substrates (Glucose and Lactate)

摘要

Corynebacterium glutamicum is an industrially important organism that is used for lysine production. Several process optimization and metabolic engineering strategies have been employed for enhancing lysine productivity. Studies have shown that the fluxes through anaplerotic reactions and glyoxalate shunt play an important role in lysine production. Analysis has also shown that C. glutamicum can grow on lactate activating gluconeogenesis. The current study focused on analyzing the phenotypic state ofC. glutamicum during its growth on a medium containing mixtures of glucose and lactate using elementary mode analysis. In silico studies show that organism was able to grow aerobically on either glucose or lactate or on a medium containing glucose and lactate. Results show that pyruvate carboxylase was more active than phospho-enol-pyruvate carboxylase with no malic enzyme activity during growth on mixed substrates. Further, the optimal phenotypic space representing different objective functions such as biomass and lysine production is presented at varying uptake rates of glucose and lactate.