Metabolic pathway analysis of glycerol metabolism in Klebsiella pneumoniae incorporating oxygen regulatory system.

It is well known that environmental and genetic perturbations have major effects on the metabolic behavior of cells. In this work, a model that utilizes existing knowledge of oxygen and redox sensing/regulatory system to assist elementary flux modes (EFMs) has been developed and was carried out to predict the metabolic potential of Klebsiella pneumoniae for the production of 1,3-propanediol (1,3-PD) under anaerobic and aerobic conditions. It was found that the theoretical optimal 1,3-PD yield could reach to 0.844 mol mol(-1) if the pentose phosphate pathway (PPP), and transhydrogenase had a high flux under anaerobic condition. However, PPP had little influence on the theoretical 1,3-PD yield, and the flux through tricarboxylic acid (TCA) cycle was high under aerobic conditions. In addition, the effect of oxygen level on the 1,3-PD and biomass was further analyzed.