Sphingobacterium thermophilum sp. nov., of the phylum Bacteroidetes, isolated from compost.

A Gram-negative bacterium, designated CKTN2(T), was isolated from compost. Cells of strain CKTN2(T) were strictly aerobic rods. The isolate grew at 20-50 °C (optimum 40-45 °C), but not below 15 °C or above 52 °C, and at pH 5.9-8.8 (optimum pH 7.0), but not below pH 5.4 or above pH 9.3. The DNA G+C content was 40.3 mol%. The predominant menaquinone was MK-7. The major fatty acids were iso-C15 : 0 (45.2 %), iso-C17 : 0 3-OH (11.1 %) and C18 : 0 (14.5 %). Analysis of the 16S rRNA gene sequence of strain CKTN2(T) revealed that it is a member of the genus Sphingobacterium and is most closely related to Sphingobacterium alimentarium DSM 22362(T) (93.2 % 16S rRNA gene sequence similarity). Strain CKTN2(T) could be distinguished from its closest phylogenetic relatives by different phenotypic characteristics. According to the phenotypic and genotypic characteristics, strain CKTN2(T) represents a novel species of the genus Sphingobacterium, for which the name Sphingobacterium thermophilum sp. nov. is proposed. The type strain is CKTN2(T) ( = JCM 17858(T)  = KCTC 23708(T)).

Thermovum composti gen. nov., sp. nov., an alphaproteobacterium from compost.

A Gram-stain-positive thermophilic bacterium, designated strain Nis3(T), was isolated from compost. The strain grew at 23-57 °C (optimum, 50 °C); no growth was observed below 15 or above 60 °C. The pH range for growth was 5.9-8.8 (optimum, 7.0); no growth was observed below pH 5.4 or above pH 9.3. The DNA G+C content of strain Nis3(T) was 63.4 mol%. The dominant quinone type was ubiquinone Q-10. The major fatty acids were C(18:1)ω7c, C(19:0)ω8c cyclo and C(18:0). The polar lipids comprised phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, hydroxyphosphatidylethanolamine, phosphatidylinositol, phosphatidylmonomethylethanolamine, an unknown glycolipid and a ninhydrin-positive phospholipid. 16S rRNA gene sequence analysis assigned this bacterium to the family Phyllobacteriaceae in the Alphaproteobacteria but it shared less than 95.2% sequence similarity with other members of the family. The chemotaxonomic and phenotypic characteristics of strain Nis3(T) differed in some respects from those of members of the family Phyllobacteriaceae. Therefore, strain Nis3(T) is considered to represent a novel species of a new genus in the family Phyllobacteriaceae, for which the name Thermovum composti gen. nov., sp. nov. is proposed. The type strain is Nis3(T) ( = JCM 17863(T) = KCTC 23707(T)).

Thermasporomyces composti gen. nov., sp. nov., a thermophilic actinomycete isolated from compost.

A thermophilic, Gram-positive bacterium that formed a branched vegetative mycelium was isolated from compost. The strain, designated I3(T), grew at temperatures between 35 and 62 °C, with optimum growth at 50-55 °C. No growth was observed below 29 °C or above 65 °C. The pH range for growth was 5.7-10.0, the pH for optimum growth was 7.0 and no growth was observed below pH 5.6 or above pH 10.8. The DNA G+C content of strain I3(T) was 69.2 mol%. The major fatty acids found were C(15 : 0) iso (14.2 %), C(15 : 0) anteiso (12.1 %), C(17 : 0) iso (16.3 %) and C(17 : 0) anteiso (21.7 %). The major menaquinones were MK-9(H(4)), MK-10(H(4)) and MK-11(H(4)). The cell wall contained glutamic acid, glycine, alanine and ll-diaminopimelic acid in a molar ratio of 1.0 : 3.9 : 0.6 : 0.5. The polar lipids consisted of ninhydrin-positive phosphoglycolipids, phosphatidylglycerol, diphosphatidylglycerol and an unknown glycolipid. The cell-wall sugars were rhamnose and arabinose. 16S rRNA gene sequence analysis assigned this actinomycete to the family Nocardioidaceae, but its 16S rRNA gene sequence shared no more than 95.5 % similarity with those of other members of the family. The chemotaxonomic and phenotypic characteristics of strain I3(T) differed in some respects from those of members of the genus Actinopolymorpha, the most closely related genus. Therefore, strain I3(T) represents a novel species in a new genus of the family Nocardioidaceae, for which the name Thermasporomyces composti gen. nov., sp. nov. is proposed. The type strain of the type species is I3(T) (=JCM 16421(T)=DSM 22891(T)).

Thermogemmatispora onikobensis gen. nov., sp. nov. and Thermogemmatispora foliorum sp. nov., isolated from fallen leaves on geothermal soils, and description of Thermogemmatisporaceae fam. nov. and Thermogemmatisporales ord. nov. within the class Ktedonobacteria.

Two thermophilic, Gram-stain-positive, sporulating bacterial strains, which formed branched vegetative and aerial mycelia, were isolated from fallen leaves sampled from geothermal soils and designated ONI-1(T) and ONI-5(T). Strain ONI-1(T) grew at 50-74 °C, with optimum growth at 60-65 °C, and strain ONI-5(T) grew at 45-74 °C, with optimum growth at 60-65 °C. The pH range for growth of the strains was pH 4.6-8.0, with optimum growth at pH 7.0. The DNA G+C contents of strains ONI-1(T) and ONI-5(T) were 60.2 and 58.1 mol%, respectively. The major fatty acid was iso-C(17 : 0) and the major menaquinone was MK-9(H(2)). The cell walls of the strains contained glutamic acid, serine, glycine, histidine, alanine and ornithine. The polar lipids consisted of phosphatidylinositol, phosphatidylglycerol and a glycolipid. The cell-wall sugar was rhamnose. Detailed phylogenetic analysis based on 16S rRNA gene sequences indicated that the strains belong to the class Ktedonobacteria and that strains ONI-1(T) and ONI-5(T) are most closely related to Thermosporothrix hazakensis SK20-1(T) (85.3 and 84.5 % sequence similarity, respectively). 16S rRNA gene sequence similarity between the two strains was 96.6 %. Based on the phenotypic features and phylogenetic position, we propose that strains ONI-1(T) and ONI-5(T) constitute a novel genus containing two novel species, for which we propose the names Thermogemmatispora onikobensis gen. nov., sp. nov. (the type species; type strain ONI-1(T)  = JCM 16817(T)  = KCTC 19768(T)) and Thermogemmatispora foliorum sp. nov. (type strain ONI-5(T)  = JCM 16818(T)  = KCTC 19767(T)), within the new family Thermogemmatisporaceae fam. nov. and order Thermogemmatisporales ord. nov.

A life cycle of branched aerial mycelium- and multiple budding spore-forming bacterium Thermosporothrix hazakensis belonging to the phylum Chloroflexi.

As far as known, sporulation modes in prokaryotes include formation of endospores exemplified by Firmicutes bacteria, myxospores by myxobacteria and arthrospores by actinomycetes. Here we describe Thermosporothrix hazakensis strain SK20-1(T) belonging to the phylum Chloroflexi with a life cycle including a novel prokaryotic sporulation mode. Microscopic observations showed that strain SK20-1(T) formed multiple exospores per mother cell by budding in branched aerial mycelia. Although branched aerial mycelia are characteristic of actinomycetes, multiple budding sporulation has not been previously described in prokaryotes. The strain SK20-1(T) could be a model microbe for cellular differentiation with multiple budding spore formation.

Thermosporothrix hazakensis gen. nov., sp. nov., isolated from compost, description of Thermosporotrichaceae fam. nov. within the class Ktedonobacteria Cavaletti et al. 2007 and emended description of the class Ktedonobacteria.

We isolated from compost an aerobic, thermophilic, Gram-stain-positive, spore-forming bacterium that formed branched vegetative and aerial mycelia. This strain, designated SK20-1T, grew at 31-58 degrees C, with optimum growth at 50 degrees C, while no growth was observed below 28 or above 60 degrees C. The pH range for growth was 5.4-8.7, with optimum growth at pH 7.0, while no growth was observed below pH 5.0 or above pH 9.1. Strain SK20-1T was able to hydrolyse polysaccharides such as cellulose, xylan and chitin. The DNA G+C content was 54.0 mol%. The major fatty acid was iso-C17:0 and the major menaquinone was MK-9(H2). The cell wall contained glutamic acid, serine, alanine and ornithine in a molar ratio of 1.00:1.07:2.64:0.83. The polar lipids consisted of phosphatidylinositol, phosphatidylinositol mannosides, phosphatidylglycerol, diphosphatidylglycerol and an unknown glycolipid. Cell-wall sugars were rhamnose and mannose. Detailed phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SK20-1T belongs to the class Ktedonobacteria, and that the strain is most closely related to Ktedonobacter racemifer SOSP1-21(T) (88.5 %). On the basis of its phenotypic features and phylogenetic position, we propose that SK20-1T represents a novel genus and species, Thermosporothrix hazakensis gen. nov., sp. nov., within the new family Thermosporotrichaceae fam. nov. The type strain of Thermosporothrix hazakensis is strain SK20-1(T) (=JCM 16142T =ATCC BAA-1881T). In addition, we propose an emended description of the class Ktedonobacteria to classify the class in the phylum Chloroflexi.

Thermaerobacter composti sp. nov., a novel extremely thermophilic bacterium isolated from compost.

A novel extremely thermophilic bacterium (Ni80T) was isolated from food sludge compost in Japan. Cells were Gram-positive, spore-forming, strictly-aerobic and rod-shaped with peritrichous flagella. The novel isolate grew at pH 6.5-10.5 but not at pH 11.0 (optimum pH 8.0) and 52-79 degrees C but not 80 degrees C (optimum 70 degrees C). The strain could not grow in more than 1% NaCl. The G+C content of the genomic DNA is 72 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain Ni80T belonged to the genus Thermaerobacter, and that the strain was most closely related to Thermaerobacter subterraneus ATCC BAA-137T (98.2%), Thermaerobacter nagasakiensis JCM 11223T (98.2%), Thermaerobacter marianensis JCM 10246T (98.0%) and Thermaerobacter litoralis JCM 13210T (97.7%). DNA-DNA hybridization showed relatedness values of less than 10% with these species. On the basis of phenotypic and molecular data, strain Ni80(T) represent a novel species of the genus Thermaerobacter, for which the name Thermaerobacter composti sp. nov. is proposed. The type strain is Ni80T (=JCM 15650T =ATCC BAA-1731T).

Isolation and characterization of predominant microorganisms during decomposition of waste materials in a field-scale composter.

A self-heating field-scale composter treating agro-industrial wastes within a period of 30 d was analyzed by denaturing gradient gel electrophoresis (DGGE) (Pedro et al., J. Biosci. Bioeng., 91, 159-165, 2001). Three major bands were derived from Propionibacterium acnes, Methylobacterium mesophilicum or M. radiotolerans, and Bacillus thermocloacae. Strains MSP09A and MSP06G with close affiliation to P. acnes and B. thermocloacae, respectively, were successfully isolated. Based on quantitative-PCR results, the relative population of MSP09A increased towards the end of the composting process (mesophilic stage) while MSP06G seemed to predominate during the middle period (thermophilic stage). These results correlated highly with their growth temperatures. MSP09A and MSP06G had different metabolic profiles which were largely affected by culture conditions. MSP09A was able to utilize large complex molecules of lipids and proteins. An interspecies relationship in terms of metabolites such as propionic acid was expected between the two microorganisms.