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Cetia pacifica gen. nov., sp. nov., a chemolithoautotrophic, thermophilic, nitrate-ammonifying bacterium from a deep-sea hydrothermal vent

Author:
Grosche, Ashley, Sekaran, Hema, Pérez-Rodríguez, Ileana, Starovoytov, Valentin, Vetriani, Costantino
Source:
International journal of systematic and evolutionary microbiology 2015 v.65 no.Pt 4 pp. 1144-1150
ISSN:
1466-5034
Subject:
DNA, acetates, bacteria, carbon, carbon dioxide, casamino acids, energy, fatty acids, flagellum, gases, genes, growth retardation, hydrogen sulfide, nitrates, oxygen, pH, phylogeny, ribosomal RNA, sodium chloride, sucrose, sulfur, tryptones, yeast extract
Abstract:
A thermophilic, anaerobic, chemolithoautotrophic bacterium, strain TB-6 ᵀ, was isolated from a deep-sea hydrothermal vent located on the East Pacific Rise at 9° N. The cells were Gram-staining-negative and rod-shaped with one or more polar flagella. Cell size was approximately 1–1.5 µm in length and 0.5 µm in width. Strain TB-6 ᵀ grew between 45 and 70 °C (optimum 55–60 °C), 0 and 35 g NaCl l ⁻¹ (optimum 20–30 g l ⁻¹) and pH 4.5 and 7.5 (optimum pH 5.5–6.0). Generation time under optimal conditions was 2 h. Growth of strain TB-6 ᵀ occurred with H ₂ as the energy source, CO ₂ as the carbon source and nitrate or sulfur as electron acceptors, with formation of ammonium or hydrogen sulfide, respectively. Acetate, (+)- d -glucose, Casamino acids, sucrose and yeast extract were not used as carbon and energy sources. Inhibition of growth occurred in the presence of lactate, peptone and tryptone under a H ₂/CO ₂ (80 : 20; 200 kPa) gas phase. Thiosulfate, sulfite, arsenate, selenate and oxygen were not used as electron acceptors. The G+C content of the genomic DNA was 36.8 mol%. Phylogenetic analysis of the 16S rRNA gene of strain TB-6 ᵀ showed that this organism branched separately from the three most closely related genera, Caminibacter , Nautilia and Lebetimonas , within the family Nautiliaceae . Strain TB-6 ᵀ contained several unique fatty acids in comparison with other members of the family Nautiliaceae . Based on experimental evidence, it is proposed that the organism represents a novel species and genus within the family Nautiliaceae , Cetia pacifica, gen. nov., sp. nov. The type strain is TB-6 ᵀ (= DSM 27783 ᵀ = JCM 19563 ᵀ).
Agid:
1326501