The genome sequence has been submitted to the EMBL database under accession number FN869568.
A blueprint of ectoine metabolism from the genome of the industrial producer Halomonas elongata DSM 2581T
Article first published online: 16 SEP 2010
© 2010 Society for Applied Microbiology and Blackwell Publishing Ltd
Thematic Issue: Extremophiles. Guest Editors: Ricardo Cavicchioli, Ricardo Amils, Dirk Wagner, Terry McGenity
Volume 13, Issue 8, pages 1973–1994, August 2011
How to Cite
Schwibbert, K., Marin-Sanguino, A., Bagyan, I., Heidrich, G., Lentzen, G., Seitz, H., Rampp, M., Schuster, S. C., Klenk, H.-P., Pfeiffer, F., Oesterhelt, D. and Kunte, H. J. (2011), A blueprint of ectoine metabolism from the genome of the industrial producer Halomonas elongata DSM 2581T. Environmental Microbiology, 13: 1973–1994. doi: 10.1111/j.1462-2920.2010.02336.x
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- Issue published online: 21 AUG 2011
- Article first published online: 16 SEP 2010
- Received 13 January, 2010; accepted 3 August, 2010.
The halophilic γ-proteobacterium Halomonas elongata DSM 2581T thrives at high salinity by synthesizing and accumulating the compatible solute ectoine. Ectoine levels are highly regulated according to external salt levels but the overall picture of its metabolism and control is not well understood. Apart from its critical role in cell adaptation to halophilic environments, ectoine can be used as a stabilizer for enzymes and as a cell protectant in skin and health care applications and is thus produced annually on a scale of tons in an industrial process using H. elongata as producer strain. This paper presents the complete genome sequence of H. elongata (4 061 296 bp) and includes experiments and analysis identifying and characterizing the entire ectoine metabolism, including a newly discovered pathway for ectoine degradation and its cyclic connection to ectoine synthesis. The degradation of ectoine (doe) proceeds via hydrolysis of ectoine (DoeA) to Nα-acetyl-l-2,4-diaminobutyric acid, followed by deacetylation to diaminobutyric acid (DoeB). In H. elongata, diaminobutyric acid can either flow off to aspartate or re-enter the ectoine synthesis pathway, forming a cycle of ectoine synthesis and degradation. Genome comparison revealed that the ectoine degradation pathway exists predominantly in non-halophilic bacteria unable to synthesize ectoine. Based on the resulting genetic and biochemical data, a metabolic flux model of ectoine metabolism was derived that can be used to understand the way H. elongata survives under varying salt stresses and that provides a basis for a model-driven improvement of industrial ectoine production.