Elimination of carbon catabolite repression in Klebsiella oxytoca for efficient 2,3-butanediol production from glucose-xylose mixtures.
Microbial preference for glucose implies incomplete and/or slow utilization of lignocellulose hydrolysates, which is caused by the regulatory mechanism named carbon catabolite repression (CCR). In this study, a 2,3-butanediol (2,3-BD) producing Klebsiella oxytoca strain was engineered to eliminate glucose repression of xylose utilization. The crp(in) gene, encoding the mutant cyclic adenosine monophosphate (cAMP) receptor protein CRP(in), which does not require cAMP for functioning, was characterized and overexpressed in K. oxytoca. The engineered recombinant could utilize a mixture of glucose and xylose simultaneously, without CCR. The profiles of sugar consumption and 2,3-BD production by the engineered recombinant, in glucose and xylose mixtures, were examined and showed that glucose and xylose could be consumed simultaneously to produce 2,3-BD. This study offers a metabolic engineering strategy to achieve highly efficient utilization of sugar mixtures derived from the lignocellulosic biomass for the production of bio-based chemicals using enteric bacteria.
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, No. 5 Xinmofan Road, Nanjing 210009, People's Republic of China.
Xiao-Jun
XJ
Ji
Zhi-Kui
ZK
Nie
He
H
Huang
Lu-Jing
LJ
Ren
Chao
C
Peng
Ping-Kai
PK
Ouyang
D002072:Butylene Glycols / Q000378:metabolism*; D057465:Catabolite Repression; D002373:Cyclic AMP Receptor Protein / Q000096:biosynthesis / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D015870:Gene Expression; D015964:Gene Expression Regulation, Bacterial; D005947:Glucose / Q000378:metabolism*; D041121:Klebsiella oxytoca / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000096:biosynthesis / Q000235:genetics; D017422:Sequence Analysis, DNA; D014994:Xylose / Q000378:metabolism*
D002072:Butylene Glycols; D002373:Cyclic AMP Receptor Protein; D004269:DNA, Bacterial; D050505:Mutant Proteins; C026978:2,3-butylene glycol; D014994:Xylose; D005947:Glucose