Haloquadratum walsbyi gen. nov., sp nov., the square haloarchaeon of Walsby, isolated from saltern crystallizers in Australia and Spain
Haloquadratum walsbyi gen. nov., sp nov., the square haloarchaeon of Walsby, isolated from saltern crystallizers in Australia and Spain
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DOI：
10.1099/ijs.0.64690-0
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发表时间：
2007-02-01
影响因子：
2.8
通讯作者：
Dyall-Smith, Mike L.
中科院分区：
文献类型：
--
作者：
Burns, David G.;Janssen, Peter H.;Dyall-Smith, Mike L.
菌株C23（T）和HBSQ 001分离自日光温室，是新的正方形，好氧，极端嗜盐的成员域的嗜盐菌和盐杆菌科。细胞染色为革兰氏阴性，在中性pH值左右的含18%盐的培养基中生长最佳。不需要Mg 2+。DNA G + C含量为46.9mol%，DNA-DNA交叉杂交显示出80%的相关性。它们的16 S rRNA基因序列仅显示2个核苷酸的差异（99.9%的同源性），与盐杆菌科其他已知成员的系统发育树重建表明，它们形成了一个不同的分支，最近的亲戚是Halogeometricum borinquense PR 3（T）（91.2%的序列同源性）。两种分离物的主要极性糖脂是硫酸化二糖基二醚脂质S-DGD-1。全细胞的冷冻电镜观察显示，HBSQ 001的细胞壁具有类似的内部结构，如气泡和聚羟基链烷酸颗粒，但与C23（T）相比，HBSQ 001的细胞壁具有更复杂的S层。表型特征和系统发育数据支持分离物C23（T）和HBSQ 001在盐杆菌科内的一个新属中的一个新种的位置，我们建议将其命名为Haloquadratum walsbyi gen. nov.，模式菌株为C23（T）（= JCM 12705（T）= DSM 16854（T））。
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. 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 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)).