464040 Construction of a Synergetic Carbon Utilization Mechanism for Biosynthesis of Glucose-Based Compounds

Tuesday, November 15, 2016: 9:24 AM
Continental 6 (Hilton San Francisco Union Square)
Yifei Wu1, Xinxiao Sun1, Yuheng Lin2, Xiaolin Shen1,2, Yaping Yang2, Rachit Jain2, Qipeng Yuan1 and Yajun Yan2, (1)College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China, (2)College of Engineering, University of Georgia, Athens, GA

Conventional glucose utilization in Escherichia coli depends on glycolysis and pentose phosphate pathway to achieve catabolism. During this process, important catabolites such as acetyl-CoA and pyruvate contribute to cell growth and product synthesis. Unconventional utilization of glucose involves applying glucose as a C6 building block for production of glucose-based compounds. This non-catabolic usage of glucose conflicts with the catabolism which naturally leads to breakdown of glucose for biomass. To reserve glucose as a building block, blocking catabolic pathways leads to cell growth retardation and thus low productivity. To address this conflict, we introduce a second carbon source glycerol and design a synergetic carbon utilization mechanism to strengthen the connection between glucose and glycerol utilization. This new mechanism couples glucose uptake and catabolism of glycerol via the phosphoenolpyruvate (PEP) as a driving force for glucose transport. We validate the mechanism by introducing glucose-based trehalose biosynthesis model. Before introducing the mechanism, the titer of trehalose is only 1.22 g l-1 by consuming 7.39 g l-1 glucose in 48 h. After enhancement and optimization of the mechanism, the titer of trehalose is 3.67 g l-1 in 48 h by consuming 5.86 g l-1 glucose. The conversion efficiency of glucose to trehalose is improved from 0.16 g trehalose/g glucose to 0.63 g trehalose/g glucose. After extension of cultivation time to 96h, 8.20 g l-1 trehalose is produced in shake flasks. Remarkably, the conversion efficiency of glucose to trehalose reaches 0.86 g trehalose/g glucose, which represents 91% of the theoretic maximum. Hence, this synergetic carbon utilization mechanism, which is established and demonstrated for the first time, can be applied for non-catabolic use of glucose as C6 building block for synthesis of glucose-based compounds. It also provides a novel strategy for industrial microbial production of trehalose.

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See more of this Session: Advances in Metabolic Engineering
See more of this Group/Topical: Food, Pharmaceutical & Bioengineering Division