title: Roseibaca ekhonensis gen. nov., sp. nov., an alkalitolerant and aerobic bacteriochlorophyll a-producing alphaproteobacterium from hypersaline Ekho Lake.
abstract: A Gram-negative, aerobic rod was isolated from the hypersaline, heliothermal and meromictic Ekho Lake (East Antarctica) at a depth of 6 m. The novel strain (designated EL-50T) was oxidase-positive and weakly catalase-positive and metabolized a variety of carboxylic acids, alcohols, sugars and lipids. Cells of strain EL-50T had an absolute requirement for artificial seawater or NaCl. Optimum growth occurred at 16 degrees C and at pH values ranging from 7.0 to 9.5. A large in vivo absorption band at 865-866 nm indicated the production of bacteriochlorophyll (bchl) a. The predominant cellular fatty acid of strain EL-50T was 18:1omega7c, with 3-OH 14:1, 16:1omega9c, 16:0 and 18:1omega9c present in lower amounts. Fatty acids 16:0 and 18:1omega9c were probably amide-linked. The main polar lipids were diphosphatidylglycerol, phospatidylethanolamine, phosphatidylglycerol and phosphatidylcholine. Ubiquinone 10 was produced. The cell-wall diamino acid was meso-diaminopimelic acid. The DNA G+C content of strain EL-50T was 61 mol%. 16S rRNA gene sequence comparisons indicated that the novel isolate was phylogenetically most closely related to alkaliphilic Rhodobaca and Roseinatronobacter species (approximately 96% 16S rRNA gene similarity). The organism had no particular relationship to any other cultivated members within the Alphaproteobacteria. The distinct morphological, physiological and genotypic differences from the previously described taxa studied supported the description of a new genus and novel species, for which the name Roseibaca ekhonensis gen. nov., sp. nov. is proposed. The type strain is EL-50T (=DSM 11469T=CECT 7235T).
authors: Institut für Allgemeine Mikrobiologie, Christian-Albrechts-Universität, Kiel, Germany. matthias.labrenz@io-warnemuende.de
authors: Matthias
authors: M
authors: Labrenz
authors: Paul A
authors: PA
authors: Lawson
authors: Brian J
authors: BJ
authors: Tindall
authors: Peter
authors: P
authors: Hirsch
mesh_terms: D000332:Aerobiosis; D000438:Alcohols / Q000378:metabolism; D020561:Alphaproteobacteria / Q000737:chemistry / Q000145:classification* / Q000302:isolation & purification* / Q000502:physiology; D025541:Bacteriochlorophyll A / Q000032:analysis*; D001482:Base Composition; D050260:Carbohydrate Metabolism; D002264:Carboxylic Acids / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005227:Fatty Acids / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000378:metabolism; D010743:Phospholipids / Q000032:analysis; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012965:Sodium Chloride / Q000378:metabolism; D013696:Temperature; D014451:Ubiquinone / Q000032:analysis; D014871:Water Microbiology
chemical_list: D000438:Alcohols; D025541:Bacteriochlorophyll A; D002264:Carboxylic Acids; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005227:Fatty Acids; D010743:Phospholipids; D012336:RNA, Ribosomal, 16S; D014451:Ubiquinone; D012965:Sodium Chloride; D010088:Oxidoreductases; D002374:Catalase