Vulcanisaeta distributa gen. nov., sp. nov., and Vulcanisaeta souniana sp. nov., novel hyperthermophilic, rod-shaped crenarchaeotes isolated from hot springs in Japan.

Abstract

Seventeen strains of rod-shaped, heterotrophic, anaerobic, hyperthermophilic crenarchaeotes were isolated from several hot spring areas in eastern Japan, and eight representative strains were characterized further. Cells of these strains were straight to slightly curved rods, 0.4-0.6 microm in width. Occasionally, cells were branched or bore spherical bodies at the poles. They grew optimally at 85-90 degrees C and at pH 4.0-4.5. They utilized yeast extract, peptone, beef extract, Casamino acids, gelatin, starch, maltose and malate as carbon sources and sulfur and thiosulfate as possible electron acceptors. The DNA G+C contents of the novel isolates were 43.9-46.2 mol%. The lipids were mainly cyclic and acyclic tetraether core lipids. Phylogenetic analysis of the 16S rDNA sequences revealed that they represented an independent lineage in the family Thermoproteaceae. Moreover, comparison of the 16S rDNA sequences and a DNA-DNA hybridization study showed that they comprised two species, which could also be differentiated by the maximal growth temperature and degrees of NaCl tolerance. Therefore, a new genus, Vulcanisaeta gen. nov., in the family Thermoproteaceae is proposed to accommodate two novel species, Vulcanisaeta distributa sp. nov. and Vulcanisaeta souniana sp. nov. The type species is V. distributa and the type strains are V. distributa IC 017T (= JCM 11212T = DSM 14429T) and V. souniana IC-059T (= JCM 11219T = DSM 14430T).

Selective Phylogenetic Analysis Targeting 16S rRNA Genes of Hyperthermophilic Archaea in the Deep-Subsurface Hot Biosphere

“…The phylogenetic analysis revealed that these OTUs belonged to the genera Vulcanisaeta, Archaeoglobus, Methanotorris, and Thermococcus. ARCS-01 and ARCS-02 were closely related to Vulcanisaeta distributa and were members of the Crenarchaeota, which is a group of heterotrophic, anaerobic, hyperthermophilic archaea commonly isolated from terrestrial hot springs (19). The ARCS-01 and ARCS-02 clones accounted for 79.2% of all the clones.…”

Defining the Functional Potential and Active Community Members of a Sediment Microbial Community in a High-Arctic Hypersaline Subzero Spring

“…S5 in the supplemental material). All of these genera are anaerobic sulfur/sulfide-oxidizing microorganisms and may participate in sulfur cycling at LH (97)(98)(99). Among these, the Thermoproteus sp., a sulfide oxidizer, may also be involved in inorganic carbon fixation; the Pyrobaculum sp., a sulfur oxidizer and denitrifier, may utilize sulfur as an electron acceptor anaerobically (98,99).…”

Cryptococcus tepidarius sp. nov., a thermotolerant yeast species isolated from a stream from a hot-spring area in Japan

“…Steam is released continuously from the ground in this area, and the atmosphere is sulfurous. Although the pH and temperature were not measured in the samples, the water in this area is acidic as a result of the presence of sulfuric and/or sulfurous ions (Itoh et al, 2002). Approximately 100 ml water was spread on Sabouraud agar plates containing 50 mg chloramphenicol ml 21 (Sankyo) and incubated at 27 uC and colonies were isolated and examined.…”