Natranaerobius thermophilus gen. nov., sp. nov., a halophilic, alkalithermophilic bacterium from soda lakes of the Wadi An Natrun, Egypt, and proposal of Natranaerobiaceae fam. nov. and Natranaerobiales ord. nov

• Published in: International journal of systematic and evolutionary microbiology Vol. 57; no. 11; pp. 2507 - 2512
• Main Authors: Mesbah, Noha M, Hedrick, David B, Peacock, Aaron D, Rohde, Manfred, Wiegel, Juergen
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01.11.2007; Society for General Microbiology
• Subjects: Bacterial Typing Techniques; Bacteriology; Biological and medical sciences; Carbonates; DNA, Bacterial - analysis; DNA, Ribosomal - analysis; Egypt; Fatty Acids - analysis; Fresh Water - chemistry; Fresh Water - microbiology; Fundamental and applied biological sciences. Psychology; Genes, rRNA; Genotype; Geologic Sediments - microbiology; Gram-Positive Bacteria - classification; Gram-Positive Bacteria - genetics; Gram-Positive Bacteria - isolation & purification; Gram-Positive Bacteria - physiology; Hot Temperature; Hydrogen-Ion Concentration; Microbiology; Miscellaneous; Molecular Sequence Data; Phenotype; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Sodium Chloride - metabolism; Systematics; Africa; Egypt; New genus; Alkalophily; Halophily; Taxonomy; Bacteria; Thermophily; New species; Soda lake
• ISSN: 1466-5026; 1466-5034
• DOI: 10.1099/ijs.0.65068-0

1 Department of Microbiology, University of Georgia, Athens, GA 30602, USA 2 University of Tennessee, Knoxville, TN 37932, USA 3 Department of Microbial Pathogenicity, Helmholtz Center for Infection, Research, Inhoffenstrasse 7, D-38124 Braunschweig, Germany Correspondence Juergen Wiegel jwiegel{at}uga.edu Novel halophilic, alkalithermophilic, Gram-type-positive bacterial strains were isolated from sediment of alkaline, hypersaline lakes of the Wadi An Natrun, Egypt. Cells of strain JW/NM-WN-LF T were rod-shaped, non-spore-forming and non-motile. Strain JW/NM-WN-LF T grew (at pH 55 °C  9.5) between 35 and 56 °C, with an optimum at 53 °C. The pH 55 °C range for growth was 8.3–10.6, with an optimum at pH 55 °C  9.5 and no growth at pH 55 °C  8.2 or below, or at pH 55 °C  10.8 or above. At the optimum pH and temperature, the strain grew in the Na + range of 3.1–4.9 M (1.5–3.3 M added NaCl) and optimally between 3.3 and 3.9 M Na + (1.7–2.3 M added NaCl). Strain JW/NM-WN-LF T utilized fructose, cellobiose, ribose, trehalose, trimethylamine, pyruvate, Casamino acids, acetate, xylose and peptone as carbon and energy sources. Fumarate (20 mM), S 2 O 3 2– (20 mM), NO 3 – (20 mM) and iron(III) citrate (20 mM) were utilized as electron acceptors. During growth on sucrose, the isolate produced acetate and formate as major fermentation products. Main cellular fatty acids were iso-branched 15 : 0, i17 : 0 dimethylacetal and 16 : 0 dimethylacetal. The G+C content of genomic DNA was 40.4 mol% (HPLC). On the basis of genotypic and phenotypic characteristics, it is proposed that strain JW/NM-WN-LF T represents a novel genus and species, Natranaerobius thermophilus gen. nov., sp. nov. The type strain is JW/NM-WN-LF T (=DSM 18059 T =ATCC BAA-1301 T ). Based on 16S rRNA gene sequence analysis, the strain forms a novel lineage within the class ‘ Clostridia ’ and clusters with uncultivated bacteria and unidentified strains retrieved from alkaline, hypersaline environments. The phylogenetic data suggest that the lineage represents a novel family, Natranaerobiaceae fam. nov., and order, Natranaerobiales ord. nov. Abbreviations: DMA, dimethylacetal; PLFA, phospholipid fatty acid The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain JW/NM-WN-LF T is DQ417202 . A supplementary table showing the PLFA composition of strain JW/NM-WN-LF T and supplementary figures showing the dependence of growth of strain JW/NM-WN-LF T on temperature and medium pH and a Fitch–Margoliash tree based on 16S rRNA gene sequences are available with the online version of this paper.