Proposal of the suffix -ota to denote phyla. Addendum to 'Proposal to include the rank of phylum in the International Code of Nomenclature of Prokaryotes'.

As an addendum to the earlier proposal to include the rank of phylum in the International Code of Nomenclature of Prokaryotes (Oren et al., Int J Syst Evol Microbiol 2015;65:4284-4287) we propose the suffix -ota to denote phyla, replacing the somewhat awkward -aeota. We therefore present a new draft modified version of Rule 8 of the International Code of Nomenclature of Prokaryotes and a corrected list of names of phyla to be considered for validation after approval of the proposal to include the rank of phylum in the Code.

Dehalogenimonas formicexedens sp. nov., a chlorinated alkane-respiring bacterium isolated from contaminated groundwater.

A strictly anaerobic, Gram-stain-negative, non-spore-forming bacterium designated NSZ-14T, isolated from contaminated groundwater in Louisiana (USA), was characterized using a polyphasic approach. Strain NSZ-14T reductively dehalogenated a variety of polychlorinated aliphatic alkanes, producing ethene from 1,2-dichloroethane, propene from 1,2-dichloropropane, a mixture of cis- and trans-1,2-dichloroethene from 1,1,2,2-tetrachloroethane, vinyl chloride from 1,1,2-trichloroethane and allyl chloride (3-chloro-1-propene) from 1,2,3-trichloropropane. Formate or hydrogen could both serve as electron donors. Dechlorination occurred between pH 5.5 and 7.5 and over a temperature range of 20-37 °C. Major cellular fatty acids included C18 : 1ω9c, C14 : 0 and C16 : 0. 16S rRNA gene sequence-based phylogenetic analysis indicated that the strain clusters within the class Dehalococcoidia of the phylum Chloroflexi, most closely related to but distinct from type strains of the species Dehalogenimonas alkenigignens (97.63 % similarity) and Dehalogenimonas lykanthroporepellens (95.05 %). A complete genome sequence determined for strain NSZ-14T revealed a DNA G+C content of 53.96 mol%, which was corroborated by HPLC (54.1±0.2 mol% G+C). Genome-wide comparisons based on average nucleotide identity by orthology and estimated DNA-DNA hybridization values combined with phenotypic and chemotaxonomic traits and phylogenetic analysis indicate that strain NSZ-14T represents a novel species within the genus Dehalogenimonas, for which the name Dehalogenimonas formicexedens sp. nov. is proposed. The type strain is NSZ-14T (=HAMBI 3672T=JCM 19277T=VKM B-3058T). An emended description of Dehalogenimonas alkenigignens is also provided.

Genome sequence of the organohalide-respiring Dehalogenimonas alkenigignens type strain (IP3-3(T)).

Dehalogenimonas alkenigignens IP3-3(T) is a strictly anaerobic, mesophilic, Gram negative staining bacterium that grows by organohalide respiration, coupling the oxidation of H2 to the reductive dehalogenation of polychlorinated alkanes. Growth has not been observed with any non-polyhalogenated alkane electron acceptors. Here we describe the features of strain IP3-3(T) together with genome sequence information and its annotation. The 1,849,792 bp high-quality-draft genome contains 1936 predicted protein coding genes, 47 tRNA genes, a single large subunit rRNA (23S-5S) locus, and a single, orphan, small unit rRNA (16S) locus. The genome contains 29 predicted reductive dehalogenase genes, a large majority of which lack cognate genes encoding membrane anchoring proteins.

Proposal to restrict the genus Clostridium Prazmowski to Clostridium butyricum and related species.

The genus Clostridium as presently constituted is phylogenetically and phenotypically incoherent. Data from polyphasic taxonomic studies indicate that the genus comprises a collection of very heterogeneous species. Numerous phylogenetic studies, principally based on sequencing of the 16S rRNA gene, indicate that the genus Clostridium should be restricted to Clostridium cluster I as Clostridium sensu stricto. Despite these findings, authors continue to add novel species to the genus Clostridium that do not fall within the radiation of cluster I and the type species Clostridium butyricum, thus perpetuating the confusion associated with the taxonomy of this group. Here, we formally propose that members of the genus Clostridium Prazmowski be restricted to the type species C. butyricum and cluster I species. Eubacterium moniliforme, Eubacterium tarantellae, Sarcina maxima and Sarcina ventriculi should be transferred to the genus Clostridium as Clostridium moniliforme comb. nov., Clostridium tarantellae comb. nov., Clostridium maximum comb. nov. and Clostridium ventriculi comb. nov. A novel genus, Hathewaya gen. nov., is proposed for the species Clostridium histolyticum, Clostridium limosum and Clostridium proteolyticum as Hathewaya histolytica gen. nov. comb. nov., Hathewaya limosa comb. nov. and Hathewaya proteolytica comb. nov. The type species of the genus Hathewaya is Hathewaya histolytica.

Proposal to include the rank of phylum in the International Code of Nomenclature of Prokaryotes.

The International Code of Nomenclature of Prokaryotes covers the nomenclature of prokaryotes up to the rank of class. We propose here modifying the Code to include the rank of phylum so that names of phyla that fulfil the rules of the Code will obtain standing in the nomenclature.

Reassessment of PCR primers targeting 16S rRNA genes of the organohalide-respiring genus Dehalogenimonas.

Representatives from the genus Dehalogenimonas have the metabolic capacity to anaerobically transform a variety of environmentally important polychlorinated aliphatic compounds. In light of the recent isolation of additional strains, description of a new species, and an expanded number of uncultured DNA sequences, PCR primers and protocols intended to uniquely target members of this organohalide-respiring genus were reevaluated. Nine of fourteen primer combinations reported previously as genus-specific failed to amplify 16S rRNA genes of recently isolated Dehalogenimonas strains. Use of alternative combinations or modified genus-specific primers, however, allowed detection of all presently known Dehalogenimonas strains. Use of a modified primer set in qPCR revealed an approximately two-order of magnitude increase in concentration of Dehalogenimonas 16S rRNA gene copies following subsurface injection of electron donors at a Louisiana Superfund site, demonstrating the utility of the newly developed protocol and suggesting that the genus Dehalogenimonas can respond to biostimulation remediation strategies in a manner similar to that previously reported for other dechlorinating genera such as Dehalococcoides.

Description of two new thermophilic species of the genus Rubrobacter, Rubrobacter calidifluminis sp. nov. and Rubrobacter naiadicus sp. nov., and emended description of the genus Rubrobacter and the species Rubrobacter bracarensis.

Four isolates, designated, RG-1(T), RG-3(T), RG-6 and RG-8 with optimum growth temperatures around 60°C were recovered from a hot stream near Ribeira Grande on the Island of São Miguel in the Azores. These strains were strictly aerobic, catalase and oxidase positive. The organisms could be divided into two groups; one comprising strains RG-1(T) and RG-6, the other formed by strains RG-3(T) and RG-8, with distinctive phenotypic and chemotaxonomic characteristics. Major fatty acids varied between the groups, but all contained iso-branched components such as iso-C16:0 10-methyl and iso-C17:0 10-methyl. Analysis of the 16S rRNA gene shows the strains to cluster with species of the genus Rubrobacter, specifically with Rubrobacter xylanophilus to which they have pairwise sequence similarity in the range of 98.4-98.6%. The DNA-DNA hybridization result show that strains RG-1(T) and RG-3(T) share 72% reassociation. Strains RG-1(T) and RG-3(T) displayed extreme tolerance to desiccation when compared to other species of the genus. Based on genotypic, physiological and biochemical characteristics we describe two new species: Rubrobacter calidifluminis sp. nov., represented by strain RG-1(T) (=CECT 8308(T) =JCM 19154(T)) and Rubrobacter naiadicus sp. nov. represented by strain RG-3(T) (=CECT 8310(T)=JCM 19155(T)). The description of the species Rubrobacter bracarensis[16] is emended to correct the fatty acid composition of these organisms. The discovery of new fatty acids in these species requires emendation of the description of the genus Rubrobacter.

Dehalogenimonas lykanthroporepellens BL-DC-9T simultaneously transcribes many rdhA genes during organohalide respiration with 1,2-DCA, 1,2-DCP, and 1,2,3-TCP as electron acceptors.

The genome sequence of the organohalide-respiring bacterium Dehalogenimonas lykanthroporepellensBL-DC-9(T) contains numerous loci annotated as reductive dehalogenase homologous (rdh) genes based on inferred protein sequence identity with functional dehalogenases of other bacterial species. Many of these genes are truncated, lack adjacent regulatory elements, or lack cognate genes coding for membrane-anchoring proteins typical of the functionally characterized active reductive dehalogenases of organohalide-respiring bacteria. To investigate the expression patterns of the rdh genes in D. lykanthroporepellensBL-DC-9(T), oligonucleotide primers were designed to uniquely target 25 rdh genes present in the genome as well as four putative regulatory genes. RNA extracts from cultures of strain BL-DC-9(T) actively dechlorinating three different electron acceptors, 1,2-dichloroethane, 1,2-dichloropropane, and 1,2,3-trichloropropane were reverse-transcribed and subjected to PCR amplification using rdh-specific primers. Nineteen rdh gene transcripts, including 13 full-length rdhA genes, six truncated rdhA genes, and five rdhA genes having cognate rdhB genes were consistently detected during the dechlorination of all three of the polychlorinated alkanes tested. Transcripts from all four of the putative regulatory genes were also consistently detected. Results reported here expand the diversity of bacteria known to simultaneously transcribe multiple rdh genes and provide insights into the transcription factors associated with rdh gene expression.

Integrating genomics into the taxonomy and systematics of the Bacteria and Archaea.

The polyphasic approach used today in the taxonomy and systematics of the Bacteria and Archaea includes the use of phenotypic, chemotaxonomic and genotypic data. The use of 16S rRNA gene sequence data has revolutionized our understanding of the microbial world and led to a rapid increase in the number of descriptions of novel taxa, especially at the species level. It has allowed in many cases for the demarcation of taxa into distinct species, but its limitations in a number of groups have resulted in the continued use of DNA-DNA hybridization. As technology has improved, next-generation sequencing (NGS) has provided a rapid and cost-effective approach to obtaining whole-genome sequences of microbial strains. Although some 12,000 bacterial or archaeal genome sequences are available for comparison, only 1725 of these are of actual type strains, limiting the use of genomic data in comparative taxonomic studies when there are nearly 11,000 type strains. Efforts to obtain complete genome sequences of all type strains are critical to the future of microbial systematics. The incorporation of genomics into the taxonomy and systematics of the Bacteria and Archaea coupled with computational advances will boost the credibility of taxonomy in the genomic era. This special issue of International Journal of Systematic and Evolutionary Microbiology contains both original research and review articles covering the use of genomic sequence data in microbial taxonomy and systematics. It includes contributions on specific taxa as well as outlines of approaches for incorporating genomics into new strain isolation to new taxon description workflows.

Substrate interactions in dehalogenation of 1,2-dichloroethane, 1,2-dichloropropane, and 1,1,2-trichloroethane mixtures by Dehalogenimonas spp.

When chlorinated alkanes are present as soil or groundwater pollutants, they often occur in mixtures. This study evaluated substrate interactions during the anaerobic reductive dehalogenation of chlorinated alkanes by the type strains of two Dehalogenimonas species, D. lykanthroporepellens and D. alkenigignens. Four contaminant mixtures comprised of combinations of the chlorinated solvents 1,2-dichloroethane (1,2-DCA), 1,2-dichloropropane (1,2-DCP), and 1,1,2-trichloroethane (1,1,2-TCA) were assessed for each species. Chlorinated solvent depletion and daughter product formation determined as a function of time following inoculation into anaerobic media revealed preferential dechlorination of 1,1,2-TCA over both 1,2-DCA and 1,2-DCP for both species. 1,2-DCA in particular was not dechlorinated until 1,1,2-TCA reached low concentrations. In contrast, both species concurrently dechlorinated 1,2-DCA and 1,2-DCP over a comparably large concentration range. This is the first report of substrate interactions during chlorinated alkane dehalogenation by pure cultures, and the results provide insights into the chlorinated alkane transformation processes that may be expected for contaminant mixtures in environments where Dehalogenimonas spp. are present.

Heliimonas saccharivorans gen. nov., sp. nov., a member of the family Chitinophagaceae isolated from a mineral water aquifer, and emended description of Filimonas lacunae.

Two isolates, with optimum growth temperature and pH of about 30 °C and 6.0-7.0, were recovered from a borehole head of a mineral water aquifer in Portugal. The closest relatives based on 16S rRNA gene sequence analysis were species of genera of the family Chitinophagaceae. Strains L2-4(T) and L2-109 formed translucent colonies and non-motile pleomorphic cells. Strains were strictly aerobic, and oxidase- and catalase-positive. The major fatty acids of strains L2-4(T) and L2-109 were 17 : 0 iso 3-OH, 15 : 0 iso and 15 : 1 iso G. The major polar lipids were phosphatidylethanolamine, one unidentified phospholipid, four unidentified aminophospholipids, four unidentified aminolipids and three unidentified polar lipids. Menaquinone 7 was the only respiratory quinone. The G+C content of the DNA of strains L2-4(T) and L2-109 was 42.0 and 41.4 mol%, respectively. Based on 16S rRNA gene sequence analysis, physiological and biochemical characteristics, strains L2-4(T) ( = CECT 8122(T) = LMG 26919(T)) and L2-109 ( = CECT 8121 = LMG 26920) are considered to represent a novel species of a new genus, for which the name Heliimonas saccharivorans gen. nov., sp. nov. is proposed. The type strain of Heliimonas saccharivorans is L2-4(T). Due to additional results obtained in this study an emended description of Filimonas lacunae is provided.

Dehalogenimonas alkenigignens sp. nov., a chlorinated-alkane-dehalogenating bacterium isolated from groundwater.

Two strictly anaerobic bacterial strains, designated IP3-3(T) and SBP-1, were isolated from groundwater contaminated by chlorinated alkanes and alkenes at a Superfund Site located near Baton Rouge, Louisiana (USA). Both strains reductively dehalogenate a variety of polychlorinated aliphatic alkanes, including 1,2-dichloroethane, 1,2-dichloropropane, 1,1,2,2-tetrachloroethane, 1,1,2-trichloroethane and 1,2,3-trichloropropane, when provided with hydrogen as the electron donor. To clarify their taxonomic position, strains IP3-3(T) and SBP-1 were characterized using a polyphasic approach. Both IP3-3(T) and SBP-1 are mesophilic, non-spore-forming, non-motile and Gram-stain-negative. Cells of both strains are irregular cocci with diameters of 0.4-1.1 µm. Both are resistant to ampicillin and vancomycin. The genomic DNA G+C contents of strains IP3-3(T) and SBP-1 are 55.5±0.4 and 56.2±0.2 mol% (HPLC), respectively. Major cellular fatty acids include C18 : 1ω9c, C16 : 0, C14 : 0 and C16 : 1ω9c. 16S rRNA gene sequence based phylogenetic analyses indicated that the strains cluster within the phylum Chloroflexi most closely related to but distinct from the species Dehalogenimonas lykanthroporepellens (96.2 % pairwise similarity) and Dehalococcoides mccartyi (90.6 % pairwise similarity). Physiological and chemotaxonomic traits as well as phylogenetic analysis support the conclusion that these strains represent a novel species within the genus Dehalogenimonas for which the name Dehalogenimonas alkenigignens sp. nov. is proposed. The type strain is IP3-3(T) ( = JCM 17062(T) = NRRL B-59545(T)).

Dehalogenimonas spp. can Reductively Dehalogenate High Concentrations of 1,2-Dichloroethane, 1,2-Dichloropropane, and 1,1,2-Trichloroethane.

The contaminant concentrations over which type strains of the species Dehalogenimonas alkenigignens and Dehalogenimonas lykanthroporepellens were able to reductively dechlorinate 1,2-dichloroethane (1,2-DCA), 1,2-dichloropropane (1,2-DCP), and 1,1,2-trichloroethane (1,1,2-TCA) were evaluated. Although initially isolated from an environment with much lower halogenated solvent concentrations, D. alkenigignens IP3-3T was found to reductively dehalogenate chlorinated alkanes at concentrations comparable to D. lykanthroporepellens BL-DC-9T. Both species dechlorinated 1,2-DCA, 1,2-DCP, and 1,1,2-TCA present at initial concentrations at least as high as 8.7, 4.0, and 3.5 mM, respectively. The ability of Dehalogenimonas spp. to carry out anaerobic reductive dechlorination even in the presence of high concentrations of chlorinated aliphatic alkanes has important implications for remediation of contaminated soil and groundwater.

Oceanicella actignis gen. nov., sp. nov., a halophilic slightly thermophilic member of the Alphaproteobacteria.

Two isolates, designated PRQ-67(T) and PRQ-68, with an optimum growth temperature of about 50°C, growth range in medium containing between 1 and 9% NaCl and an optimum pH for growth between 7.5 and 8.0, were recovered from a shallow marine hot spring on a beach, Praia do Fogo, at Ribeira Quente, on the Island of São Miguel in the Azores. Comparisons of 16S rRNA gene sequences show these strains to be most closely related (93.1-94.7% similarity) to species of the genus Amaricoccus, within the family Rhodobacteraceae. Strains are non-pigmented and form non-motile pleomorphic cells that stain Gram-negative, are aerobic, oxidase and catalase positive. The major fatty acids are C(18:1)ω7c and C(18:1)ω7c 11-methyl. Ubiquinone 10 is the major respiratory quinone. Major polar lipids are phosphatidylcholine, phosphatidylglycerol and one aminolipid. Based on 16S rRNA gene sequence analysis, physiological and biochemical characteristics we describe a new species of a novel genus represented by strain PRQ-67(T) (=DSM 22673(T)=LMG 25334(T)) for which we propose the name Oceanicella actignis.

Complete genome sequence of Dehalogenimonas lykanthroporepellens type strain (BL-DC-9(T)) and comparison to "Dehalococcoides" strains.

Dehalogenimonas lykanthroporepellens is the type species of the genus Dehalogenimonas, which belongs to a deeply branching lineage within the phylum Chloroflexi. This strictly anaerobic, mesophilic, non spore-forming, Gram-negative staining bacterium was first isolated from chlorinated solvent contaminated groundwater at a Superfund site located near Baton Rouge, Louisiana, USA. D. lykanthroporepellens was of interest for genome sequencing for two reasons: (a) an unusual ability to couple growth with reductive dechlorination of environmentally important polychlorinated aliphatic alkanes and (b) a phylogenetic position that is distant from previously sequenced bacteria. The 1,686,510 bp circular chromosome of strain BL-DC-9(T) contains 1,720 predicted protein coding genes, 47 tRNA genes, a single large subunit rRNA (23S-5S) locus, and a single, orphan, small subunit rRNA (16S) locus.

Hydrotalea sandarakina sp. nov., isolated from a hot spring runoff, and emended descriptions of the genus Hydrotalea and the species Hydrotalea flava.

Two bacterial isolates, designated AF-51(T) and AF-50, with an optimum growth temperature of about 45 °C and an optimum pH for growth between 6.0 and 6.5, were recovered from a hot spring in the Furnas, Área da Fonte 1825, on the Island of São Miguel in the Azores. Based on 16S rRNA gene sequence analysis, these strains were related most closely to the type strain of Hydrotalea flava at a pairwise similarity of 95.7%. The two strains were orange-pigmented and formed non-motile, rod-shaped cells that stained Gram-negative and were aerobic and oxidase- and catalase-positive. The major fatty acids were iso-C(15:0), iso-C(17:0) 3-OH and iso-C(16:0). The major respiratory quinone was menaquinone 7. Based on phylogenetic, physiological and biochemical characteristics, these strains from the Azores are considered to represent a single novel species of the genus Hydrotalea, for which the name Hydrotalea sandarakina sp. nov. is proposed. The type strain is AF-51(T) (=DSM 23241(T)=LMG 25526(T)). We provide emended descriptions of the genus Hydrotalea and of H. flava to reflect new results obtained in this study.

Pelosinus defluvii sp. nov., isolated from chlorinated solvent-contaminated groundwater, emended description of the genus Pelosinus and transfer of Sporotalea propionica to Pelosinus propionicus comb. nov.

Two anaerobic bacterial strains, designated SHI-1(T) and SHI-2, were isolated from chlorinated solvent-contaminated groundwater. They were found to be identical in phenotypic properties and shared high (98.5-99.8 %) pairwise 16S rRNA gene sequence similarity. Multiple 16S rRNA genes were found to be present in the isolates as well as Pelosinus fermentans DSM 17108(T) and Sporotalea propionica DSM 13327(T). Strains SHI-1(T) and SHI-2 could be differentiated from their closest phylogenetic relatives, P. fermentans DSM 17108(T) and S. propionica DSM 13327(T), on the basis of their phenotypic and phylogenetic properties. The isolates were Gram-negative, spore-forming, motile rods with peritrichous flagella. Growth occurred at 10-42 °C and pH 5.5-8.5. Fermentative growth was observed on Casamino acids, fructose, fumarate, glucose, glycerol, pyruvate and yeast extract. The major organic acids produced from glucose and glycerol fermentation were propionate and acetate. The major organic acids produced from fermentation of fumarate were propionate, acetate and succinate. The major cellular fatty acids were summed feature 4 (consisting of C(15:1)ω8c and/or C(15:2)), summed feature 8 (consisting of C(17:1)ω8c and/or C(17:2)) and C(14:0) dimethyl aldehyde. The polar lipids comprised aminophospholipids, including phosphatidylethanolamine and phosphatidylserine, and an unknown phospholipid. The genomic DNA G+C content was 39.2 mol%. We propose that strains SHI-1(T) and SHI-2 are assigned to a novel species of the genus Pelosinus, with the name Pelosinus defluvii sp. nov. (type strain SHI-1(T) = NRRL Y-59407(T) = LMG 25549(T)). The description of the genus Pelosinus is emended. We also propose the transfer of S. propionica to the genus Pelosinus as Pelosinus propionicus comb. nov. (type strain TmPN3(T) = DSM 13327(T) = ATCC BAA-626(T)), on the basis of phylogenetic, chemotaxonomic and phenotypic properties.

Actinomyces naturae sp. nov., the first Actinomyces sp. isolated from a non-human or animal source.

Three facultatively anaerobic, Gram-positive staining, rod-shaped, non-spore forming, flagellated bacterial strains, BL-75, BL-79(T) and BL-104, were isolated from chlorinated solvent-contaminated groundwater. Phylogenetic analysis based on 16S rRNA gene sequence comparisons showed them to represent a distinct lineage within the genus Actinomyces with sequence identities in the range of <88-95.4% with previously described Actinomyces species. The strains were oxidase and catalase negative. Nitrate was not reduced. Esculin was hydrolyzed. Growth occurred in the temperature range of 20-43°C (optimum 30-37°C) and pH range 4.5-9.0 (optimum pH 6.5). Substrates supporting growth included various mono-, di-, and tri-saccharides. The end products of glucose fermentation were acetate, lactate, succinate and formate. Fermentative growth was observed in the presence of near saturation concentrations of perchloroethene (PCE) and toluene and in the presence of 1,2-dichloroethane and 1,1,2-trichloroethane at concentrations up to at least 24.4 mM and 11.2 mM, respectively. The dominant cellular fatty acids when grown in peptone/yeast extract/glucose (PYG) medium were C(18:1) ω9c, C(16:0), and C(14:0). The peptidoglycan was found to contain the amino acids alanine, glutamic acid, lysine, and ornithine at approximate molar ratios of 1.7 Ala: 2.3 Glu: 1.3 Lys: 1.0 Orn. The cell wall sugars were found to include rhamnose and mannose. The polar lipids were found to include diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phospholipid (PL), phosphoglycolipids (PGL), and glycolipids (GL). The main respiratory quinone of strain BL-79(T) was MK-9(H(4)), with minor components MK-10(H(4)) and MK-8(H(4)). The DNA mol% G+C content of the type strain is 69.8%. On the basis of phylogenetic and phenotypic characteristics, these strains could be differentiated from previously described species of the genus Actinomyces. Strains BL-75, BL-79(T) and BL-104 are designated as a novel species, for which the name Actinomyces naturae sp. nov. is proposed. This is the first Actinomyces species isolated from an environmental rather than human or animal sources. The type strain of Actinomyces naturae is BL-79(T) (= CCUG 56698(T) = NRRL B-24670(T)).

Gaiella occulta gen. nov., sp. nov., a novel representative of a deep branching phylogenetic lineage within the class Actinobacteria and proposal of Gaiellaceae fam. nov. and Gaiellales ord. nov.

Two isolates, with an optimum growth temperature of about 35-37°C and an optimum pH for growth between 6.5 and 7.5, were recovered from a deep mineral water aquifer in Portugal. Strains form rod-shaped cells and were non-motile. These strains were non-pigmented, strictly aerobic, catalase and oxidase positive. Strains F2-233(T) and F2-223 assimilated carbohydrates, organic acids and amino acids. Major fatty acids were novel iso internally branched such as 17:0 iso 10-methyl, 17:0 iso and 15:0 iso 8-methyl. The peptidoglycan contained meso-diaminopimelic acid and menaquinone MK-7 was the major respiratory quinone. Analysis of the 16S rRNA gene shows the strains to cluster with species of the genera Thermoleophilum, Patulibacter, Conexibacter and Solirubrobacter to which they have pairwise sequence similarity in the range 87-88%. Based on 16S rRNA gene sequence analysis, physiological and biochemical characteristics we describe a new species of a novel genus represented by strain F2-233(T) (=CECT 7815(T)=LMG 26412(T)) for which we propose the name Gaiella occulta gen. nov., sp. nov. We also propose that this organism represents a novel family named Gaiellaceae fam. nov. of a novel order named Gaiellales ord. nov.

Schleiferia thermophila gen. nov., sp. nov., a slightly thermophilic bacterium of the phylum 'Bacteroidetes' and the proposal of Schleiferiaceae fam. nov.

A bacterial isolate, with an optimum growth temperature of about 50 °C and an optimum pH for growth between 7.5 and 8.5, was recovered from a hot spring in the Furnas area of the Island of São Miguel in the Azores. The novel isolate is orange-pigmented, forms non-motile, rod-shaped cells that stain Gram-negative, is strictly aerobic, oxidase-positive and catalase-negative. The major fatty acids of strain TU-20(T) are 16 : 1ω6c, 17 : 0 iso 3-OH and 15 : 0 iso. Menaquinone 6 is the major respiratory quinone. Based on 16S rRNA gene sequence analysis, physiological and biochemical characteristics, we describe a novel species of a novel genus represented by strain TU-20(T) ( = DSM 21410(T ) = LMG 24594(T)) for which we propose the name Schleiferia thermophila gen nov., sp. nov. We also propose the family Schleiferiaceae fam. nov. to accommodate this new genus.