Wolinella succinogenes
A Microbial Biorealm page on the genus Wolinella succinogenes
Classification
Higher order taxa
cellular organisms; Bacteria; Proteobacteria; delta/epsilon subdivisions; Epsilonproteobacteria; Campylobacterales; Helicobacteraceae; Wolinella
Species
succinogenes
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NCBI: Taxonomy |
Description and significance
Wolinella succinogenes belongs to the epsilon subclass of Proteobacteria along with its close relatives Helicobacter pylori, Helicobacter hepaticus, and Campylobacter jejuni. H.pyori and C. jejuni are of the groups Helicobacteraceae and Campylobacteraceae respectively which are harmful pathogens in humans and animals. H. pylori has been associated with ulcers and gastric cancer and C. jejuni has been found to cause the illness Guillain-Barre syndrome. Although the name Wolinella succinogenes has been coined as a member of Helicobacteraceae, the species exists phylogenetically as an intermediate between the two groups mentioned. It was originally isolated from cattle rumen where it resides and then was re-isolated by other molecular methods. Although it is found to be a nonpathogenic host-associated organism, it contains many virulence genes that are identical to those throughout the rest of the Helicobacteraceae and Campylobacteraceae groups.(3)
Genome structure
Shotgun sequencing of the Wolinella succinogenes genome revealed that it is composed of a circular chromosome of 2,110,355 base pairs. No plasmids were found (1). Having a larger genome content than its relatives H. pylori, H. hepiticus,and C.jejuni, enables W.succinogenes to adapt to its bovine host rather its counterparts that occupy humans and rodents. "The close relatedness W. succinogenes has to the other three species, [H.pylori, H. hepiticus, C.jejuni], has been demonstrated using morphological, physiological, and molecular classification methods, and this reflected in their gene content as they share ~50% of their genes". (2) This large range of uniformity in genomic content along with W.succinogenes having a larger genomic content suggests that the four relatives stem from a larger ancestral genome. Flexibe genomic islands and islets have been observed in particular regions of the genome suggesting that recent gene transfer into W. succinogenes may have occured. Therefore, "The 29% larger genome of W. succinogenes codes for genes not found in any of its epsilon-proteobacterial relatives...seem[ing] likely that W. succinogenes may not be restricted to its ecological niche in the bovine rumen."(1)
Cell structure and metabolism
Wolinella succinogenes is a cylindrical shaped organism with a single flagella at one of its poles. It is a nonfermenting bacterium with fumurate as its sole carbon source. Therefore it undergoes anaerobic fumerate respiration. Wolinella succinogenes also contains protective enzymes that allow the bacteria to deal with reactive oxygen that may alter the cell. There is no evidence for glucose fermentation however the phosofructokinase-encoding gene provides a pathway from glucose-6 phosphate to pyruvate suggesting that "W.succinogenes uses glycolytic enzynes solely for gluconeogenisis." (1)
Ecology
The most useful aspect of research of Wolinella succinogenes is the contribution of furthur understanding the existing pathogens in its relatives. With increased knowledge of structure and function, the structure and function of closely related species can also be better understood.
Pathology
There is no current evidence indicating that Wolinella succinogenes itself is pathogenic although its close relatives are. There are however identical virulance factors seen in W. succinogenes that are also seen elsewhere. Although H. pylori is a very close relative, it has be found that W.succinogenes contains many genes that have been identified as virulance factors in C.jujeni. In particular, the key pathogen agent of C.jejuni, "antigen B", is also found in W.succinogenes but not in any of the other close relatives. (1)
Application to Biotechnology
W. succinogenes is known to have the largest density of Two Component Signal Transduction (TCST) proteins. These proteins enable the bacterium to monitor stimuli in its environment. W.succinogenes' wide variety of TCST's suggests a capability to reside in more than one biological niche. "Extensive two-component signaling networks have been considered a hallmark of environmental strains capable of dwelling in a wide variety of growth conditions and bacteria with complex life cycles" (1)
Current Research
1. Stephan C. Schuster, Associate Professor of Biochemistry and Molecular Biology has provided much information of his work on Wolinella succinogenes. Current research in his lab at Penn State University is working toward identifying genes unique to W. succinogenes, C. jejuni, and H. pylori. He states that "by studying those genes that are being shared by all three organisms, [he] can identify essential molecular mechanisms used by symbiotic, commensal or pathogenic bacteria to maintain themselves in a vertebrate host environment.(4)
2. The work described in reference #3, as noted by author, "provides the basis for further functional and structural studies of these membrane–protein complexes and for the screening of new and highly effective inhibitors." Their research on the membrane bound proteins observed in W.succinogenes will help for further understanding in this arena.(3)
3. Research of genes common to more than one species has greatly advanced the knowledge of pathogenic mechanisms. Further research in other common genes and expressions of them will add to the current understanding thus far. (2)
References
(1) Baar C et al. (2003)
Baar, C., Eppinger, M., Raddatz, G., Simon, J., Lanz, C., Klimmek, O., Nandakumar, R., Gross, R., Rosinus, A., Keller, H., Jagtap, P., Linke, B., Meyer, F., Lederer, H., and Schuster, S.C. "Complete genome sequence and analysis of Wolinella succinogenes." Proc. Natl. Acad. Sci. USA (2003) 100:11690-11695.
(2)Epinge, M., Baar, C., Raddarz, G., Huson, D., Schuster, S. "Comparative Analysis of Four Campylobacterales." Nature Reviews Microbiology, 2, 872-885.
(3)Mileni, M., MacMillan, F., Tziatzios, C., Zwicker, K., Haas, A., Mäntele, W., Simon, J., Lancaster, C. "Heterologous production in Wolinella succinogenes and characterization of the quinol:fumarate reductase enzymes from Helicobacter pylori and Campylobacter jejun." Biochem J. 2006 April 1; 395(Pt 1): 191–201.
Published online 2006 March 15. Prepublished online 2005 December 21. doi: 10.1042/BJ20051675.
Copyright The Biochemical Society, London.
(4) Stephan C. Schuster. Associate Professor of Biochemistry and Molecular Biology. "Genome evolution in host-adapted bacteria." website: http://www.bmb.psu.edu/faculty/schuster/schuster.html
Edited by Desiree Navadeh, student of Rachel Larsen and Kit Pogliano
