Analyzing the Metabolic Network of Zymomonas mobilis ZM4 by Genome-scale Reconstruction for Overproducing Ethanol and Succinic acid

Abstract

Zymomonas mobilis ZM4 is Gram-negative bacterium that can efficiently produce ethanol from glucose, fructose, and sucrose by utilizing the Entner-Doudoroff pathway. To improve its industrial application, the genome-scale metabolic model of Z. mobilis is reconstructed and examined using constraints-based flux analysis. First, the physiological changes of Z. mobilis shifts from anaerobic to aerobic environments were investigated. Then the intensities of flux-sum, and the maximum in silico yields of ethanol for Z. mobilis and Escherichia coli were compared. Furthermore, the substrate utilization range of Z. mobilis was expanded to pentose sugar metabolism. Finally, double gene knock-out simulations were performed to suggest a strategy for overproducing succinic acid.