title: Improvement of xylose utilization in Clostridium acetobutylicum via expression of the talA gene encoding transaldolase from Escherichia coli.
abstract: Clostridium acetobutylicum ATCC 824 was metabolically engineered for improved xylose utilization. The gene talA, which encodes transaldolase from Escherichia coli K-12, was cloned and overexpressed in C. acetobutylicum ATCC 824. Compared with C. acetobutylicum ATCC 824 (824-WT), the transformant bearing the E. coli talA gene (824-TAL) showed improved ability on xylose utilization and solvents production using xylose as the sole carbon source. During the fermentation of xylose and glucose mixtures with three xylose/glucose ratios (approximately 1:2, 1:1 and 2:1), the rate of xylose consumption and final solvents titers of 824-TAL were all higher than those of 824-WT, despite glucose repression on xylose uptake still existing. These results suggest that the insufficiency of transaldolase in the pentose phosphate pathway (PPP) of C. acetobutylicum is one of the bottlenecks for xylose metabolism and therefore, overexpressing the gene encoding transaldolase is able to improve xylose utilization and solvent production.
authors.affiliation: Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Gu
authors.forename: Jian
authors.initials: J
authors.lastname: Li
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.forename: Lixia
authors.initials: L
authors.lastname: Niu
authors.forename: Yunliu
authors.initials: Y
authors.lastname: Yang
authors.forename: Sheng
authors.initials: S
authors.lastname: Yang
authors.forename: Weihong
authors.initials: W
authors.lastname: Jiang
mesh_terms: D018929:Cell Culture Techniques / Q000379:methods; D046969:Clostridium acetobutylicum / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D003470:Culture Media; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D029968:Escherichia coli Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D005285:Fermentation; D015870:Gene Expression; D005947:Glucose / Q000378:metabolism; D012997:Solvents / Q000378:metabolism; D014153:Transaldolase / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D014994:Xylose / Q000378:metabolism*
chemical_list: D003470:Culture Media; D029968:Escherichia coli Proteins; D012997:Solvents; D014994:Xylose; D014153:Transaldolase; D005947:Glucose