Metabolic engineering of D-xylose pathway in Clostridium beijerinckii to optimize solvent production from xylose mother liquid.
Clostridium beijerinckii is an attractive butanol-producing microbe for its advantage in co-fermenting hexose and pentose sugars. However, this Clostridium strain exhibits undesired efficiency in utilizing D-xylose, one of the major building blocks contained in lignocellulosic materials. Here, we reported a useful metabolic engineering strategy to improve D-xylose consumption by C. beijerinckii. Gene cbei2385, encoding a putative D-xylose repressor XylR, was first disrupted in the C. beijerinckii NCIMB 8052, resulting in a significant increase in D-xylose consumption. A D-xylose proton-symporter (encoded by gene cbei0109) was identified and then overexpressed to further optimize D-xylose utilization, yielding an engineered strain 8052xylR-xylT(ptb) (xylR inactivation plus xylT overexpression driven by ptb promoter). We investigated the strain 8052xylR-xylT(ptb) in fermenting xylose mother liquid, an abundant by-product from industrial-scale xylose preparation from corncob and rich in D-xylose, finally achieving a 35% higher Acetone, Butanol and Ethanol (ABE) solvent titer (16.91 g/L) and a 38% higher yield (0.29 g/g) over those of the wild-type strain. The strategy used in this study enables C. beijerinckii more suitable for butanol production from lignocellulosic materials.
Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
Han
H
Xiao
Zhilin
Z
Li
Yu
Y
Jiang
Yunliu
Y
Yang
Weihong
W
Jiang
Yang
Y
Gu
Sheng
S
Yang
D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics; D003013:Clostridium / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D055785:Gene Knockdown Techniques; D060847:Metabolic Engineering; D009004:Monosaccharide Transport Proteins / Q000096:biosynthesis / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D012997:Solvents / Q000378:metabolism*; D027981:Symporters / Q000096:biosynthesis / Q000235:genetics; D014994:Xylose / Q000235:genetics / Q000378:metabolism
D001426:Bacterial Proteins; D009004:Monosaccharide Transport Proteins; D012097:Repressor Proteins; D012997:Solvents; D027981:Symporters; D014994:Xylose