This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Strobel, H. J. Articles by Dawson, K. A. Search for Related Content PubMed PubMed Citation Articles by Strobel, H. J. Articles by Dawson, K. A. Agricola Articles by Strobel, H. J. Articles by Dawson, K. A.

 Previous Article  |  Next Article 

Appl. Environ. Microbiol., Nov 1995, 4012-4015, Vol 61, No. 11
Copyright © 1995, American Society for Microbiology

Carbohydrate Transport by the Anaerobic Thermophile Clostridium thermocellum LQRI

HJ Strobel, FC Caldwell and KA Dawson
Department of Animal Sciences, University of Kentucky, Lexington, Kentucky 40546-0215

Clostridium thermocellum is an anaerobic thermophilic bacterium which degrades cellulose and ferments the resulting glucose, cellobiose, and cellodextrins predominantly to ethanol. However, relatively little information was available on carbohydrate uptake by this bacterium. Washed cells internalized intact oligomers as large as cellopentaose. Since cellobiose and cellodextrin phosphorylase activities were detected in the cytosol and were not associated with cell membranes, phosphorylation of carbohydrates occurred intracellularly. Kinetic studies indicated that cellobiose and larger cellodextrins were taken up by a common uptake system while glucose entered via a separate mechanism. When cells were treated with metabolic inhibitors including iodoacetate and arsenate, the uptake of radiolabeled glucose or cellobiose was reduced by as much as 90%, and this reduction was associated with a 95% decline in intracellular ATP content. A combination of the ionophores nigericin and valinomycin abolished the proton-motive force but only slightly decreased transport and ATP. These results suggested that the two modes of carbohydrate transport in C. thermocellum were ATP dependent. This work is the first demonstration of cellodextrin transport by a cellulolytic bacterium.

This article has been cited by other articles:

• Ruas-Madiedo, P., Hernandez-Barranco, A., Margolles, A., de los Reyes-Gavilan, C. G. (2005). A Bile Salt-Resistant Derivative of Bifidobacterium animalis Has an Altered Fermentation Pattern When Grown on Glucose and Maltose. Appl. Environ. Microbiol. 71: 6564-6570 [Abstract] [Full Text]  
• Zhang, Y.-H. P., Lynd, L. R. (2005). Cellulose utilization by Clostridium thermocellum: Bioenergetics and hydrolysis product assimilation. Proc. Natl. Acad. Sci. USA 102: 7321-7325 [Abstract] [Full Text]  
• Zhang, Y.-H. P., Lynd, L. R. (2004). Kinetics and Relative Importance of Phosphorolytic and Hydrolytic Cleavage of Cellodextrins and Cellobiose in Cell Extracts of Clostridium thermocellum. Appl. Environ. Microbiol. 70: 1563-1569 [Abstract] [Full Text]  
• Dror, T. W., Morag, E., Rolider, A., Bayer, E. A., Lamed, R., Shoham, Y. (2003). Regulation of the Cellulosomal celS (cel48A) Gene of Clostridium thermocellum Is Growth Rate Dependent. J. Bacteriol. 185: 3042-3048 [Abstract] [Full Text]  
• Kaplan, H., Hutkins, R. W. (2003). Metabolism of Fructooligosaccharides by Lactobacillus paracasei 1195. Appl. Environ. Microbiol. 69: 2217-2222 [Abstract] [Full Text]  
• Lynd, L. R., Weimer, P. J., van Zyl, W. H., Pretorius, I. S. (2002). Microbial Cellulose Utilization: Fundamentals and Biotechnology. Microbiol. Mol. Biol. Rev. 66: 506-577 [Abstract] [Full Text]  
• Desvaux, M., Guedon, E., Petitdemange, H. (2001). Carbon Flux Distribution and Kinetics of Cellulose Fermentation in Steady-State Continuous Cultures of Clostridium cellulolyticum on a Chemically Defined Medium. J. Bacteriol. 183: 119-130 [Abstract] [Full Text]  
• Desvaux, M., Guedon, E., Petitdemange, H. (2000). Cellulose Catabolism by Clostridium cellulolyticum Growing in Batch Culture on Defined Medium. Appl. Environ. Microbiol. 66: 2461-2470 [Abstract] [Full Text]  
• Guedon, E., Desvaux, M., Petitdemange, H. (2000). Kinetic Analysis of Clostridium cellulolyticum Carbohydrate Metabolism: Importance of Glucose 1-Phosphate and Glucose 6-Phosphate Branch Points for Distribution of Carbon Fluxes Inside and Outside Cells as Revealed by Steady-State Continuous Culture. J. Bacteriol. 182: 2010-2017 [Abstract] [Full Text]  
• Kajikawa, H., Masaki, S. (1999). Cellobiose Transport by Mixed Ruminal Bacteria from a Cow. Appl. Environ. Microbiol. 65: 2565-2569 [Abstract] [Full Text]  
• Guedon, E., Payot, S., Desvaux, M., Petitdemange, H. (1999). Carbon and Electron Flow in Clostridium cellulolyticum Grown in Chemostat Culture on Synthetic Medium. J. Bacteriol. 181: 3262-3269 [Abstract] [Full Text]