Quantifying the metabolic capabilities of engineered Zymomonas mobilis using linear programming analysis

Abstract

Background: The need for discovery of alternative, renewable, environmentally friendly energy sources and the development of cost-efficient, "clean" methods for their conversion into higher fuels becomes imperative. Ethanol, whose significance as fuel has dramatically increased in the last decade, can be produced from hexoses and pentoses through microbial fermentation. Importantly, plant biomass, if appropriately and effectively decomposed, is a potential inexpensive and highly renewable source of the hexose and pentose mixture. Recently, the engineered (to also catabolize pentoses) anaerobic bacterium Zymomonas mobilis has been widely discussed among the most promising microorganisms for the microbial production of ethanol fuel. However, Z. mobilis genome having been fully sequenced in 2005, there is still a small number of published studies of its in vivo physiology and limited use of the metabolic engineering experimental and computational toolboxes to understand its metabolic pathway interconnectivity and regulation towards the optimization of its hexose and pentose fermentation into ethanol.

Genome‐scale modeling and in silico analysis of ethanologenic bacteria Zymomonas mobilis

“…Such genome-scale in silico models have been built for various microbes, for example, E. coli (Feist et al, 2007), S. cerevisiae (Mo et al, 2009), and Pichia pastoris (Chung et al, 2010), and even for mammalian cells (Duarte et al, 2007;Selvarasu et al, 2009). There has been an initial attempt to model the metabolic network of Z. mobilis covering the amino acid biosynthetic pathway with emphasis on the central carbon metabolism (Tsantili et al, 2007). In addition, a dynamic model of Z. mobilis was also developed for analyzing the inhibitory effect of ethanol on glucose and sucrose fermentation (Lee and Huang, 2000).…”

Assessment of Zymomonas mobilis biotechnological potential in ethanol production by flux variability analysis

“…The first stoichiometric models of Z. mobilis were published without available metabolic model files (Lee et al, 2010;Tsantili et al, 2007;Widiastuti et al, 2011) and therefore were not directly applicable for modeling and optimization. In this study the stoichiometric model of Z. mobilis central metabolism (Pentjuss, et al, 2013a) is used.…”

Hardness and Approximability of the Inverse Scope Problem

“…Identifying the biosynthetic capabilities of a given organism is crucial for the development of cost-efficient energy sources, as they are directly related to plant biomass [20], [16], [3]. On the other hand, knowing the compounds necessary for obtaining a desired product can be employed in designing optimal environmental conditions, in the sense of minimizing the nutrients for biosynthesis, and for effective altering of bioprocesses to assist the industrial manufacture of chemicals [4].…”