Transcriptional analysis of catabolite repression in Clostridium acetobutylicum growing on mixtures of D-glucose and D-xylose

J Biotechnol. 2010 Nov;150(3):315-23. doi: 10.1016/j.jbiotec.2010.09.938. Epub 2010 Sep 29.


Clostridium acetobutylicum is a strict anaerobic organism that is used for biotechnological butanol fermentation. It ferments various hexoses and pentoses to solvents but prefers glucose presumably using a catabolite repression mechanism. Accordingly during growth on a mixture of D-glucose and D-xylose a typical diauxic growth pattern was observed. We used DNA microarrays and real-time RT-PCR to study gene expression during growth on D-glucose, D-xylose mixtures on a defined minimal medium together with monitoring substrate consumption and product formation. We identified two putative operons involved in D-xylose degradation. The first operon (CAC1344-CAC1349) includes a transporter, a xylulose-kinase, a transaldolase, a transketolase, an aldose-1-epimerase and a putative xylose isomerase that has been annotated as an arabinose isomerase. This operon is induced by D-xylose but was catabolite repressed by D-glucose. A second operon (CAC2610-CAC2612) consists of a xylulose-kinase, a hypothetical protein and a gene that has been annotated as a L-fucose isomerase that might in fact code for a xylose isomerase. This operon was induced by D-xylose but was not subject to catabolite repression. In accordance with these results we identified a CRE site in the catabolite repressed operon but not in the operon that was not subject to catabolite repression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • Butanols / metabolism
  • Clostridium acetobutylicum / enzymology
  • Clostridium acetobutylicum / genetics*
  • Clostridium acetobutylicum / metabolism
  • Fermentation
  • Gene Expression Profiling
  • Gene Expression Regulation, Bacterial
  • Glucose / metabolism*
  • Metabolic Networks and Pathways
  • Oligonucleotide Array Sequence Analysis
  • Phenotype
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism
  • Response Elements / genetics
  • Reverse Transcriptase Polymerase Chain Reaction
  • Xylose / metabolism*


  • Bacterial Proteins
  • Butanols
  • Repressor Proteins
  • Xylose
  • Glucose