An aerobic, saccharolytic, obligately thermophilic, motile, non-spore-forming bacterium, strain T49T, was isolated from geothermally heated soil at Hell’s Gate, Tikitere, New Zealand. On the basis of 16S rRNA gene sequence similarity, T49T is the first representative of a new class in the newly described phylum Armatimonadetes, formerly known as candidate division OP10. Cells of strain T49T stained Gram-negative and were catalase-positive and oxidase-negative. Cells possessed a highly corrugated outer membrane. The major fatty acids were 16 : 0, i17 : 0 and ai17 : 0. The G+C content of the genomic DNA was 54.6 mol%. Strain T49T grew at 50–73 °C with an optimum temperature of 68 °C, and at pH 4.7–5.8 with an optimum growth pH of 5.3. A growth rate of 0.012 h−1 was observed under optimal temperature and pH conditions. The primary respiratory quinone was MK-8. Optimal growth was achieved in the absence of NaCl, although growth was observed at NaCl concentrations as high as 2 % (w/v). Strain T49T was able to utilize mono- and disaccharides such as cellobiose, lactose, mannose and glucose, as well as branched or amorphous polysaccharides such as starch, CM-cellulose, xylan and glycogen, but not highly linear polysaccharides such as crystalline cellulose or cotton. On the basis of its phylogenetic position and phenotypic characteristics, we propose that strain T49T represents a novel bacterial genus and species within the new class Chthonomonadetes classis nov. of the phylum Armatimonadetes. The type strain of Chthonomonas calidirosea gen. nov., sp. nov. is T49T ( = DSM 23976T = ICMP 18418T).

Three thermophilic Nanoarchaeota-Crenarchaeota symbiotic systems have been described. We obtained another stable anaerobic enrichment culture at 80°C, pH 6.0 from a New Zealand hot spring. The nanoarchaeote (Ncl-1) and its host (NZ3) were isolated in co-culture and their genomes assembled. The small (∼200nm) flagellated cocci were often attached to larger cocci. Based on 16S rRNA gene similarity (88.4%) and average amino acid identity (52%), Ncl-1 is closely related to Candidatus Nanopusillus acidilobi. Their genomes both encode for archaeal flagella and partial glycolysis and gluconeogenesis pathways, but lack ATP synthase genes. Like Nanoarchaeum equitans, Ncl-1 has a CRISPR-Cas system. Ncl-1 also relies on its crenarchaeotal host for most of its biosynthetic needs. The host NZ3 was isolated and grows on proteinaceous substrates but not on sugars, alcohols, or fatty acids. NZ3 requires thiosulfate and grows best at 82°C, pH 6.0. NZ3 is most closely related to the Desulfurococcaceae, Ignisphaera aggregans (∼92% 16S rRNA gene sequence similarity, 45% AAI). Based on phylogenetic, physiological and genomic data, Ncl-1 and NZ3 represent novel genera in the Nanoarchaeota and the Desulfurococcaceae, respectively, with the proposed names Candidatus Nanoclepta minutus and Zestosphaera tikiterensis gen. nov., sp. nov., type strain NZ3 (=DSMZ 107634=OCM 1213).

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Pyrinomonas methylaliphatogenes gen. nov., sp. nov., a novel group 4 thermophilic member of the phylum Acidobacteria from geothermal soils An aerobic, thermophilic, moderately acidophilic non-spore-forming bacterium, strain K22 T , was isolated from geothermally heated soil at Mount Ngauruhoe, New Zealand. On the basis of 16S rRNA gene sequence similarity, K22 T was shown to belong to subdivision 4 of the phylum Acidobacteria and to be most closely related to 'Candidatus Chloracidobacterium thermophilum' (86 %) and Blastocatella fastidiosa (86 %). Cells stained Gram-negative and were catalase and oxidase-positive. The major fatty acids detected were iso-C 15 : 0 , iso-C 17 : 0 , iso-C 19 : 0 and iso-C 21 : 0 when standard lipid extraction protocols were employed. Analysis of the total cell lipid acid hydrolysate also detected membrane-spanning and ether lipids, which made up approximately 40 % of the total membrane composition. These lipids included dicarboxylic (iso-diabolic) acid and the glyceryl ether of alkyl analogues of iso-C 15 : 0 and iso-diabolic acid. The G+C content of the genomic DNA was 59.6 mol% and the primary respiratory quinone was MK-8. Strain K22 T grew at 50-69 6C with an optimum temperature of 65 6C and at pH 4.1-7.8 with an optimum growth pH of 6.5. NaCl tolerance was up to 1 % (w/v). Cells displayed a chemoheterotrophic and obligately aerobic metabolism. Cells grew on nutrient broth, alginate, arabinose, Casamino acids, glucose, lactate, formate, mannose, sodium alginate, peptone, sucrose, tryptone, xanthan, xylan, xylose and yeast extract. Nitrogen sources included nitrate, ammonium, urea, yeast extract and Casamino acids, but not dinitrogen gas. The distinct phylogenetic position and the phenotypic characteristics separate strain K22 T from all other members of the class Acidobacteria and indicate that it represents a novel species and genus, for which the name Pyrinomonas methylaliphatogenes gen. nov., sp. nov. is proposed. The type strain of the type species is K22The Acidobacteria are a large and diverse bacterial phylum detected over a range of environments (Barns et al., 1999), particularly in soil ecosystems (Janssen, 2006). There are currently a total of 7734 16S rRNA gene non-redundant phylotypes grouping within the phylum Acidobacteria as per the latest version of the ARB-SILVA (SSU r113 NR) database (Pruesse et al., 2007). However, to date, only 15 genera in five of the approximately 26 subdivisions in this phylum (Barns et al.,

Nine non-pigmented, motile, Gram-negative bacteria originally designated as Alteromonas macleodii deep-sea ecotypes, were isolated from seawater samples collected from four separate locations; two deep-sea sites in the Mediterranean Sea and surface water of the Aegean Sea and English Channel. The six strains studied in vitro were found to tolerate up to 20 % NaCl. The DNA-DNA relatedness between the deep-sea ecotype strains was found to be between 75 and 89 %, whilst relatedness with the validly named Alteromonas species was found to be between 31 and 69 %. The average nucleotide identity (ANI) amongst the deep-sea ecotype strains was found to be 98-100 %; the in silico genome-to-genome distance (GGD), 85-100 %; the average amino acid identity (AAI) of all conserved protein-coding genes, 95-100 %; and the strains possessed 30-32 of the Karlin's genomic signature dissimilarity. The ANI between the deep-sea ecotype strains and A. macleodii ATCC 27126(T) and Alteromonas australica H 17(T) was found to be 80.6 and 74.6 %, respectively. A significant correlation was observed between the phenotypic data obtained in vitro and data retrieved in silico from whole genome sequences. The results of a phylogenetic study that incorporated a 16S rRNA gene sequence analysis, multilocus phylogenetic analysis (MLPA) and genomic analysis, together with the physiological, biochemical and chemotaxonomic data, clearly indicated that the group of deep-sea ecotype strains represents a distinct species within the genus Alteromonas. Based on these data, a new species, Alteromonas mediterranea, is proposed. The type strain is DE(T) ( = CIP 110805(T) = LMG 28347(T) = DSM 17117(T)).