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 Han, J.
Right arrow Articles by Xiang, H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Han, J.
Right arrow Articles by Xiang, H.
Agricola
Right arrow Articles by Han, J.
Right arrow Articles by Xiang, H.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, October 2007, p. 6058-6065, Vol. 73, No. 19
0099-2240/07/$08.00+0     doi:10.1128/AEM.00953-07
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Molecular Characterization of the phaECHm Genes, Required for Biosynthesis of Poly(3-Hydroxybutyrate) in the Extremely Halophilic Archaeon Haloarcula marismortui{triangledown}

Jing Han,1,2,{dagger} Qiuhe Lu,1,2,{dagger} Ligang Zhou,1,2 Jian Zhou,1 and Hua Xiang1*

State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences,1 Graduate University of Chinese Academy of Sciences, Beijing, People's Republic of China2

Received 28 April 2007/ Accepted 28 July 2007

Although many haloarchaea produce biodegradable polyhydroxyalkanoates (PHAs), the genes involved in PHA synthesis in the domain of Archaea have not yet been experimentally investigated yet. In this study, we revealed that Haloarcula marismortui was able to accumulate poly(3-hydroxybutyrate) (PHB) up to 21% of cellular dry weight when cultured in a minimal medium with excessive glucose and identified the phaEHm and phaCHm genes, probably encoding two subunits of a class III PHA synthase. These two genes were adjacent and directed by a single promoter located 26 bp upstream of the transcriptional start site and were constitutively expressed under both nutrient-rich and -limited conditions. Interestingly, PhaCHm was revealed to be strongly bound with the PHB granules, but PhaEHm seemed not to be. Introduction of either the phaEHm or phaCHm gene into Haloarcula hispanica, which harbors highly homologous phaECHh genes, could enhance the PHB synthesis in the recombinant strains, while coexpression of the both genes always generated the highest PHB yield. Significantly, knockout of the phaECHh genes in H. hispanica led to a complete loss of the PHA synthase activity. Complementation with phaECHm genes, but not a single one, restored the capability of PHB accumulation as well as the PHA synthase activity in this phaEC-deleted haloarchaeon. These results indicated that the phaEC genes are required for biosynthesis of PHB and might encode an active PHA synthase in the Haloarcula species.

* Corresponding author. Mailing address: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Datun Road, Chaoyang District, Beijing 100101, People's Republic of China. Phone: (86) 10-6480-7472. Fax: (86) 10-6480-7472. E-mail: xiangh{at}sun.im.ac.cn

{triangledown} Published ahead of print on 3 August 2007.

{dagger} J.H. and Q.L. contributed equally to this paper.

Applied and Environmental Microbiology, October 2007, p. 6058-6065, Vol. 73, No. 19
0099-2240/07/$08.00+0     doi:10.1128/AEM.00953-07
Copyright © 2007, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Han, J., Lu, Q., Zhou, L., Liu, H., Xiang, H. (2009). Identification of the Polyhydroxyalkanoate (PHA)-Specific Acetoacetyl Coenzyme A Reductase among Multiple FabG Paralogs in Haloarcula hispanica and Reconstruction of the PHA Biosynthetic Pathway in Haloferax volcanii. Appl. Environ. Microbiol. 75: 6168-6175 [Abstract] [Full Text]  
  • Jahns, A. C., Rehm, B. H. A. (2009). Tolerance of the Ralstonia eutropha Class I Polyhydroxyalkanoate Synthase for Translational Fusions to Its C Terminus Reveals a New Mode of Functional Display. Appl. Environ. Microbiol. 75: 5461-5466 [Abstract] [Full Text]  
  • Jendrossek, D. (2009). Polyhydroxyalkanoate Granules Are Complex Subcellular Organelles (Carbonosomes). J. Bacteriol. 191: 3195-3202 [Full Text]  
  • Lu, Q., Han, J., Zhou, L., Zhou, J., Xiang, H. (2008). Genetic and Biochemical Characterization of the Poly(3-Hydroxybutyrate-co-3-Hydroxyvalerate) Synthase in Haloferax mediterranei. J. Bacteriol. 190: 4173-4180 [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»