This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Zhang, Y.-H. P.
Right arrow Articles by Lynd, L. R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Zhang, Y.-H. P.
Right arrow Articles by Lynd, L. R.

 Previous Article  |  Next Article 

Journal of Bacteriology, January 2005, p. 99-106, Vol. 187, No. 1
0021-9193/05/$08.00+0     doi:10.1128/JB.187.1.99-106.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.

Regulation of Cellulase Synthesis in Batch and Continuous Cultures of Clostridium thermocellum

Yi-Heng Percival Zhang1 and Lee R. Lynd1,2*

Thayer School of Engineering,1 Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire2

Received 16 July 2004/ Accepted 19 September 2004

Regulation of cell-specific cellulase synthesis (expressed in milligrams of cellulase per gram [dry weight] of cells) by Clostridium thermocellum was investigated using an enzyme-linked immunosorbent assay protocol based on antibody raised against a peptide sequence from the scaffoldin protein of the cellulosome (Zhang and Lynd, Anal. Chem. 75:219-227, 2003). The cellulase synthesis in Avicel-grown batch cultures was ninefold greater than that in cellobiose-grown batch cultures. In substrate-limited continuous cultures, however, the cellulase synthesis with Avicel-grown cultures was 1.3- to 2.4-fold greater than that in cellobiose-grown cultures, depending on the dilution rate. The differences between the cellulase yields observed during carbon-limited growth on cellulose and the cellulase yields observed during carbon-limited growth on cellobiose at the same dilution rate suggest that hydrolysis products other than cellobiose affect cellulase synthesis during growth on cellulose and/or that the presence of insoluble cellulose triggers an increase in cellulase synthesis. Continuous cellobiose-grown cultures maintained either at high dilution rates or with a high feed substrate concentration exhibited decreased cellulase synthesis; there was a large (sevenfold) decrease between 0 and 0.2 g of cellobiose per liter, and there was a much more gradual further decrease for cellobiose concentrations >0.2 g/liter. Several factors suggest that cellulase synthesis in C. thermocellum is regulated by catabolite repression. These factors include: (i) substantially higher cellulase yields observed during batch growth on Avicel than during batch growth on cellobiose, (ii) a strong negative correlation between the cellobiose concentration and the cellulase yield in continuous cultures with varied dilution rates at a constant feed substrate concentration and also with varied feed substrate concentrations at a constant dilution rate, and (iii) the presence of sequences corresponding to key elements of catabolite repression systems in the C. thermocellum genome.

* Corresponding author. Mailing address: Thayer School of Engineering, 8000 Cummings Hall, Dartmouth College, Hanover, NH 03755. Phone: (603) 646-2231. Fax: (603) 646-2277. E-mail: lee.r.lynd{at}dartmouth.edu.

Journal of Bacteriology, January 2005, p. 99-106, Vol. 187, No. 1
0021-9193/05/$08.00+0     doi:10.1128/JB.187.1.99-106.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Abdou, L., Boileau, C., de Philip, P., Pages, S., Fierobe, H.-P., Tardif, C. (2008). Transcriptional Regulation of the Clostridium cellulolyticum cip-cel Operon: a Complex Mechanism Involving a Catabolite-Responsive Element. J. Bacteriol. 190: 1499-1506 [Abstract] [Full Text]  
  • Gold, N. D., Martin, V. J. J. (2007). Global View of the Clostridium thermocellum Cellulosome Revealed by Quantitative Proteomic Analysis. J. Bacteriol. 189: 6787-6795 [Abstract] [Full Text]  
  • Newcomb, M., Chen, C.-Y., Wu, J. H. D. (2007). Induction of the celC operon of Clostridium thermocellum by laminaribiose. Proc. Natl. Acad. Sci. USA 104: 3747-3752 [Abstract] [Full Text]  
  • Lu, Y., Zhang, Y.-H. P., Lynd, L. R. (2006). Enzyme-microbe synergy during cellulose hydrolysis by Clostridium thermocellum. Proc. Natl. Acad. Sci. USA 103: 16165-16169 [Abstract] [Full Text]  
  • Kato, S., Haruta, S., Cui, Z. J., Ishii, M., Igarashi, Y. (2005). Stable Coexistence of Five Bacterial Strains as a Cellulose-Degrading Community. Appl. Environ. Microbiol. 71: 7099-7106 [Abstract] [Full Text]  
  • Stevenson, D. M., Weimer, P. J. (2005). Expression of 17 Genes in Clostridium thermocellum ATCC 27405 during Fermentation of Cellulose or Cellobiose in Continuous Culture. Appl. Environ. Microbiol. 71: 4672-4678 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»