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Haloquadratum walsbyi gen. nov., sp. nov., the square haloarchaeon of Walsby, isolated from saltern crystallizers in Australia and Spain

Burns, David G. and Janssen, Peter H. and Itoh, Takashi and Kamekura, Masahiro and Li, Zhuo and Jensen, Grant J. and Rodríguez-Valera, Francisco and Bolhuis, Henk and Dyall-Smith, Mike L. (2007) Haloquadratum walsbyi gen. nov., sp. nov., the square haloarchaeon of Walsby, isolated from saltern crystallizers in Australia and Spain. International Journal of Systematic and Evolutionary Microbiology, 57 (2). pp. 387-392. ISSN 1466-5026. doi:10.1099/ijs.0.64690-0.

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Strains C23^T and HBSQ001 were isolated from solar salterns and are novel square-shaped, aerobic, extremely halophilic members of the domain Archaea and family Halobacteriaceae. Cells stained Gram-negative and grew optimally in media containing 18 % salts at around neutral pH. Mg^(2+) is not required. The DNA G+C content of both isolates was 46.9 mol% and DNA–DNA cross-hybridization showed a relatedness of 80 %. Their 16S rRNA gene sequences showed only 2 nucleotide differences (99.9 % identity) and phylogenetic tree reconstructions with other recognized members of the Halobacteriaceae indicated that they formed a distinct clade, with the closest relative being Halogeometricum borinquense PR 3^T (91.2 % sequence identity). The major polar glycolipid of both isolates was the sulfated diglycosyl diether lipid S-DGD-1. Electron cryomicrosopy of whole cells revealed similar internal structures, such as gas vesicles and polyhydroxyalkanoate granules, but the cell wall of isolate HBSQ001 displayed a more complex S-layer compared with that of isolate C23^T. The phenotypic characterization and phylogenetic data support the placement of isolates C23^T and HBSQ001 in a novel species in a new genus within the Halobacteriaceae, for which we propose the name Haloquadratum walsbyi gen. nov., sp. nov. The type strain of Haloquadratum walsbyi is C23^T (=JCM 12705^T=DSM 16854^T).

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Jensen, Grant J.0000-0003-1556-4864
Additional Information:Copyright © 2007 International Union of Microbiological Societies. The authors thank Professor Dr Hans G. Trüper for his advice regarding nomenclature. We thank Dr Jane Ding for her help in writing a module of measuring the distance between membrane layers. D. G. B. was supported by an Australian Post-graduate Award. M. L. D.-S. was supported by a University of Melbourne MRGS award in 2005 and by the Department of Microbiology and Immunology. G. J. was supported by NIH grant R01 AI067548. H. B. was supported by a grant from the Netherlands Organization of Science NWO/ALW/NPP-851.20.023. The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA gene sequences of isolates C23^T and HBSQ001 are respectively AY676200 and AM180088.
Funding AgencyGrant Number
Australian Post-graduate AwardUNSPECIFIED
University of MelbourneUNSPECIFIED
NIHR01 AI067548
Netherlands Organization of ScienceNWO/ALW/NPP-851.20.023
Issue or Number:2
Record Number:CaltechAUTHORS:20110803-134318931
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:24663
Deposited By: George Porter
Deposited On:03 Aug 2011 21:30
Last Modified:09 Nov 2021 16:25

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