Previous Article | Next Article 
Journal of Bacteriology, January 2009, p. 152-160, Vol. 191, No. 1
0021-9193/09/$08.00+0 doi:10.1128/JB.01105-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.
Macroamphiphilic Components of Thermophilic Actinomycetes: Identification of Lipoteichoic Acid in Thermobifida fusca
,
Obaidur Rahman,1
Markus Pfitzenmaier,2
Oxana Pester,1,
Siegfried Morath,3
Stephen P. Cummings,1
Thomas Hartung,4 and
Iain C. Sutcliffe1*
School of Applied Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST, United Kingdom,1 Department of Organic Chemistry, University of Marburg, 35043 Marburg, Germany,2 EU Joint Research Centre, Institute for Health and Consumer Protection In-Vitro Toxicology Unit/European Centre for the Validation of Alternative Methods (ECVAM), T.P. 580, Via E. Fermi 2749, I-21027 Ispra,3 EU Joint Research Centre, Institute for the Protection and the Security of the Citizen (IPSC), Traceability, Risk and Vulnerability Assessment Unit (TRiVA), 21027 Ispra, Italy4
Received 7 August 2008/ Accepted 13 October 2008
The cell envelopes of gram-positive bacteria contain structurally diverse membrane-anchored macroamphiphiles (lipoteichoic acids and lipoglycans) whose functions are poorly understood. Since regulation of membrane composition is an important feature of adaptation to life at higher temperatures, we have examined the nature of the macroamphiphiles present in the thermophilic actinomycetes Thermobifida fusca and Rubrobacter xylanophilus. Following hot-phenol-water extraction and purification by hydrophobic interaction chromatography, Western blotting with a monoclonal antibody against lipoteichoic acid strongly suggested the presence of a polyglycerophosphate lipoteichoic acid in T. fusca. This structure was confirmed by chemical and nuclear magnetic resonance analyses, which confirmed that the lipoteichoic acid is substituted with β-glucosyl residues, in common with the teichoic acid of this organism. In contrast, several extraction methods failed to recover significant macroamphiphilic carbohydrate- or phosphate-containing material from R. xylanophilus, suggesting that this actinomycete most likely lacks a membrane-anchored macroamphiphile. The finding of a polyglycerophosphate lipoteichoic acid in T. fusca suggests that lipoteichoic acids may be more widely present in the cell envelopes of actinomycetes than was previously assumed. However, the apparent absence of macroamphiphiles in the cell envelope of R. xylanophilus is highly unusual and suggests that macroamphiphiles may not always be essential for cell envelope homeostasis in gram-positive bacteria.
* Corresponding author. Mailing address: Biomolecular and Biomedical Research Centre, School of Applied Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST, United Kingdom. Phone: 44 191 227 4071. Fax: 44 191 227 3519. E-mail: iain.sutcliffe{at}unn.ac.uk
Published ahead of print on 17 October 2008.
Supplemental material for this article may be found at http://jb.asm.org/.
Present address: Technische Universität München, Lehrstuhl für Chemie der Biopolymere, Weihenstephaner Berg 3, D-85354 Freising, Germany.
Journal of Bacteriology, January 2009, p. 152-160, Vol. 191, No. 1
0021-9193/09/$08.00+0 doi:10.1128/JB.01105-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»