@article{mbs:/content/journal/ijsem/10.1099/ijs.0.64690-0, author = "Burns, David G. and Janssen, Peter H. and Itoh, Takashi and Kamekura, Masahiro and Li, Zhuo and Jensen, Grant and Rodríguez-Valera, Francisco and Bolhuis, Henk and Dyall-Smith, Mike L.", title = "Haloquadratum walsbyi gen. nov., sp. nov., the square haloarchaeon of Walsby, isolated from saltern crystallizers in Australia and Spain", journal= "International Journal of Systematic and Evolutionary Microbiology", year = "2007", volume = "57", number = "2", pages = "387-392", doi = "https://doi.org/10.1099/ijs.0.64690-0", url = "https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijs.0.64690-0", publisher = "Microbiology Society", issn = "1466-5034", type = "Journal Article", keywords = "SHOW, square haloarchaea of Walsby", keywords = "PHA, polyhydroxyalkanoate", abstract = "Strains C23T 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. Mg2+ 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 3T (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 C23T. The phenotypic characterization and phylogenetic data support the placement of isolates C23T 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 C23T (=JCM 12705T=DSM 16854T).", }