Caloramator mitchellensis sp. nov., a thermoanaerobe isolated from the geothermal waters of the Great Artesian Basin of Australia, and emended description of the genus Caloramator

Abstract

A strictly thermophilic anaerobe, designated strain VF08T, was isolated from a water sample collected from a Great Artesian Basin bore (registered bore number 22981) situated at Mitchell, QLD, Australia. Cells of isolate VF08T were slightly curved, non-sporulating rods (1.5–3.5×0.4–0.8 μm), which stained Gram-negative but possessed a Gram-positive cell-wall ultrastructure. The strain grew optimally in tryptone-yeast extract-glucose (TYEG) medium at 55 °C (temperature growth range between 37 and 60 °C) and a pH of 7 (pH growth range, 6.0–9.0). Yeast extract or tryptone was required for growth on glucose, fructose, xylose, maltose, sucrose, raffinose, cellobiose, ribose, pyruvate, tryptone, peptone, Casamino acids, amyl media and serine, but could also support growth as the sole carbon source. End products from glucose fermentation were acetate, ethanol, CO2 and H2. The strain reduced vanadium(V), but not iron(III), manganese(IV), elemental sulfur, sulfate, thiosulfate, sulfite, nitrate or nitrite in the presence of 0.2 % yeast extract, peptone, tryptone, glucose, sucrose and Casamino acids, but an increase in the growth rate or cell yield was not observed. Growth was inhibited by chloramphenicol, streptomycin, tetracycline, penicillin, ampicillin and ≥2 % NaCl (w/v). The G+C content of the DNA was 38.4±0.8 mol% as determined by the thermal denaturation (T m) method. 16S rRNA gene sequence analysis revealed that isolate VF08T was a member of the genus Caloramator with Caloramator australicus and Caloramator fervidus (formerly Clostridium fervidus) being the closest relatives with similarity values of 85.0 and 86.1 %, respectively, when helix 6 nucleotides were included in the analysis, and 95.2 % and 94 %, respectively, when these nucleotides were masked from the analysis. Further analysis revealed that strain VF08T formed an individual cluster (cluster II) within the genus Caloramator and could be distinguished from other species within the genus Caloramator (clusters I, III and IV) on the basis of signature nucleotides and differences in phenotypic traits. These data suggest that strain VF08T is a novel species of the genus Caloramator, for which the name Caloramator mitchellensis sp. nov. is proposed. The type strain is VF08T (=JCM 15828T=KCTC 5735T). An emended description of the genus Caloramator is also provided.

Comparison of prokaryotic communities among fields exhibiting different disinfestation effects by anaerobic soil disinfestation

“…Therefore, environmental changes might have promoted the increased abundance of Clostridia, some of which play important roles in the suppression of pathogen growth and proliferation. Caloramator are rod-shaped, obligate anaerobic, thermophilic endospore-producers that ferment several sugars and produce acetate, isobutyrate, lactate, and other volatile fatty acids (VFAs) but do not degrade cellulose [25,29]. More than half of clostridial clones that were increased after ASD treatment belonged to Clostridium cluster I, which included the Oxobacter and Caloramator groups [30].…”

Caloramator quimbayensis sp. nov., an anaerobic, moderately thermophilic bacterium isolated from a terrestrial hot spring

“…Genomic DNA was isolated from cells of the novel strain and purified by chromatography on hydroxyapatite before its G+C content (32.6 mol%) Table 1. Phenotypic traits of strain USBA A T and established members of the genus Caloramator Strains: 1, USBA A T (data from this study); 2, C. mitchellensis VF08 T (Ogg & Patel, 2011a); 3, C. australicus RC3 T (Ogg & Patel, 2009); 4, C. viterbiensis JW/MS-VS5 T (Seyfried et al, 2002); 5, C. coolhaasii Z T (Plugge et al, 2000); 6, C. proteoclasticus U T (Tarlera et al, 1997); 7, C. indicus IndiB4 T (Chrisostomos et al, 1996); 8, C. fervidus Rt4-B1 T (Patel et al, 1987). Cells of strain USBA A T and the type strains of C. mitchellensis, C. australicus, C. viterbiensis are Gram-staining-positive whereas those of the type strains of C. coolhaasii, C. proteoclasticus, C. indicus and C. fervidus are Gram-staining-negative even though they have a cell-wall ultrastructure of the Gram-positive-type.…”

“…The current, established members of the genus Caloramator, 'Caloramator uzoniensis' and Thermobrachium celere were recently separated into four clusters (I, II, III and IV) on the basis of 14 key signature nucleotides in their 16S rRNA genes (Ogg & Patel, 2011a). In comparisons based on 13 such signature nucleotides, strain USBA A T was found to have nine, five, seven and nine signatures in common with clusters I, II, III and IV, respectively.…”

“…At the time of writing, all members of the genus Caloramator are strict anaerobes and ferment carbohydrate (particularly glucose, fructose, maltose, galactose and sucrose) in the presence of trace amounts of yeast extract. Recently the members of the genus were differentiated into four clusters based on the signature nucleotides of their 16S rRNA genes (Ogg & Patel, 2011a), and the complete genome of C. australicus was also sequenced (Ogg & Patel, 2011b). In this paper, the characteristics of a novel Caloramator-like bacterium that was isolated from a hot spring in the Andes mountains are described.…”

Draft Genome Sequence of Caloramator australicus Strain RC3 T , a Thermoanaerobe from the Great Artesian Basin of Australia

“…T (ϭ JCM 15081 T ϭ KCTC 5601 T ) is a Gram-positive thermoanaerobe of the phylum Firmicutes which was isolated from a gelatinous red microbial mat thriving at 66°C in the runoff channel of a Great Artesian Basin (GAB) bore (New Lorne bore, registered number 17263) (2,5,6). C. australicus and C. proteoclasticus are the only members of the 10 species of the genus Caloramator which utilize a variety of metals [iron(III), manganese(IV), and vanadium(V)] as the terminal electron acceptor.…”