Engineered xylose utilization enhances bio-products productivity in the cyanobacterium Synechocystis sp. PCC 6803

Journal Article · Fri Jun 12 04:00:00 EDT 2015 · Metabolic Engineering

DOI:https://doi.org/10.1016/j.ymben.2015.06.002· OSTI ID:1225916

Lee, Tai-Chi; Xiong, Wei; Paddock, Troy; Carrieri, Damian; Chang, Ing-Feng; Chiu, Hui-Fen; Ungerer, Justin; Hank Juo, Suh-Hang; Maness, Pin-Ching; Yu, Jianping

Hydrolysis of plant biomass generates a mixture of simple sugars that is particularly rich in glucose and xylose. Fermentation of the released sugars emits CO₂ as byproduct due to metabolic inefficiencies. Therefore, the ability of a microbe to simultaneously convert biomass sugars and photosynthetically fix CO₂ into target products is very desirable. In this work, the cyanobacterium, Synechocystis 6803, was engineered to grow on xylose in addition to glucose. Both the xylA (xylose isomerase) and xylB (xylulokinase) genes from Escherichia coli were required to confer xylose utilization, but a xylose-specific transporter was not required. Introducing xylAB into an ethylene-producing strain increased the rate of ethylene production in the presence of xylose. Additionally, introduction of xylAB into a glycogen-synthesis mutant enhanced production of keto acids. Moreover, isotopic tracer studies found that nearly half of the carbon in the excreted keto acids was derived from the engineered xylose metabolism, while the remainder was derived from CO₂ fixation.

• Research Organization: National Renewable Energy Lab. (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Fuel Cell Technologies Program (EE-3F)
• DOE Contract Number: AC36-08GO28308
• OSTI ID: 1225916
• Report Number(s): NREL/JA--2700-62711
• Journal Information: Metabolic Engineering, Journal Name: Metabolic Engineering Journal Issue: C Vol. 30; ISSN 1096-7176
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
Synechocystis 6803
cyanobacteria
isotopic tracing
photomixotrophic growth
xylose isomerase
xylose utilization
xylulokinase