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A co-culture of a novel thermoacidophilic, obligate symbiotic archaeon, designated as strain MJ1T, with its specific host archaeon Metallosphaera sedula strain MJ1HA was obtained from a terrestrial hot spring in Japan. Strain MJ1T grew in the co-culture under aerobic conditions. Coccoid cells of strain MJ1T were 200–500 nm in diameter, and attached to the MJ1HA cells in the co-culture. The ranges and optima of the growth temperature and pH of strain MJ1T in the co-culture were 60–75 °C (optimum, 65–70 °C) and pH 1.0–4.0 (optimum, pH 2.5), respectively. Core lipids of dialkyl glycerol tetraethers (GDGT)−3 and GDGT-4 were highly abundant in MJ1T cells concentrated from the co-culture. Strain MJ1T has a small genome (0.67 Mbp) lacking genes for biosynthesis of essential biomolecules, such as nucleotides, lipids and ATP. The genomic DNA G+C content was 24.9 mol%. The 16S rRNA gene sequence of strain MJ1T was most closely related to that of the cultivated species, ‘Nanopusillus acidilobi’ strain N7A (85.8 % similarity). Based on phylogenetic and physiological characteristics, we propose the name Nanobdella aerobiophila gen. nov., sp. nov. to accommodate the strain MJ1T (=JCM 33616T=DSM 111728T). In addition, we propose the names Nanobdellaceae fam. nov., Nanobdellales ord. nov., and Nanobdellia class. nov. to accommodate the novel genus.

The frequency of transconjugants were compared for the incompatibility (Inc) P-1 and P-7 plasmids pBP136 and pCAR1 under aerobic and anaerobic conditions. Filter mating assays were performed with one donor strain and one recipient strain using different donors of Pseudomonas and recipient strains, including Pseudomonas, Pantoea, and Buttiauxella. Under anaerobic condition, frequencies of transconjugants for both plasmids were 101-103-fold lower than those under aerobic condition regardless of whether aerobically or anaerobically grown donors and recipients were used. To compare the transconjugant ranges under aerobic and anaerobic conditions, conjugation was performed between the donor of pBP136 and recipient bacteria extracted from environmental samples. Several transconjugants were uniquely obtained from each aerobic or anaerobic condition. Our findings indicate that a plasmid can differently spread among bacteria depending on the oxygen concentrations of the environment.

A novel actinomycete strain, CT2-14T, belonging to the genus Nocardia , was isolated from a soil sample collected from Phichit Province, Thailand. The taxonomic position of the strain was characterized using a polyphasic approach. The strain grew at 15–40 °C (optimum, 28–37 °C), pH 6–11 (optimum, pH 6–8) and on an International Streptomyces Project 2 with 4 % (w/v) NaCl agar plate. Meso-diaminopimelic acid was detected in the cell-wall peptidoglycan. Ribose, arabinose and galactose were detected in its whole-cell hydrolysates. Mycolic acids were present. The strain contained C16 : 0, summed feature 3, C17 : 0 10-methyl and C18 : 1 ω9c as the major fatty acids and MK-8(H4ω-cycl) as the major menaquinone. The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylinositol mannosides. Strain CT2-14T showed the highest 16S rRNA gene similarity to Nocardia veterana JCM 11307T (98.4 %), Nocardia africana JCM 11438T (98.2 %) and Nocardia kruczakiae JCM 13032T (98.0 %). The draft genome of strain CT2-14T was 7.37 Mb with 6685 coding sequences with an average G+C content of 67.9 mol %. Based on the phylogenomic tree analysis, the strain was closely related to Nocardia niigatensis NBRC 100131T. On the basis of polyphasic and genome analyses, strain CT2-14T represented a novel species of the genus Nocardia for which the name Nocardia aurantiaca sp. nov. is proposed. The type strain is CT2-14T (=JCM 33775T=TISTR 2838T).

Two strains of lactic acid bacteria, designated Hs20B0-1T and Hs30E4-3T, were isolated from the gut of the damp-wood termite Hodotermopsis sjostedti. These strains were characterized genetically and phenotypically. Strain Hs20B0-1T was related to Lactococcus piscium DSM 6634T showing 96.3 and 84.2 % sequence similarity in 16S rRNA gene and rpoB gene sequences, respectively. Strain Hs30E4-3T was related to Lactococcus plantarum DSM 20686T showing 94.8 and 82.2 % sequence similarity in 16S rRNA gene and rpoB gene sequences, respectively. The 16S rRNA gene sequence similarity between strains Hs20B0-1T and Hs30E4-3T was 95.7 %. Furthermore, genomic comparisons using pairwise average nucleotide identity (ANI) and digital DNA–DNA hybridization (DDH) analyses between strain Hs20B0-1T and L. piscium DSM 6634T resulted in values of 73.5 and 20.1 %, respectively. Strain Hs30E4-3T had 72.8 % ANI similarity and 21.3 % DDH similarity to L. plantarum DSM 20686T. Strains Hs20B0-1T and Hs30E4-3T had 75.4 % ANI similarity and 21.1 % DDH similarity to each other. The cell-wall peptidoglycan types of strains Hs20B0-1T and Hs30E4-3T were A4α, Lys-Asp and A3α, Lys–Thr–Ala, respectively. The two strains, Hs20B0-1T and Hs30E4-3T, are distinguishable from each other and other established Lactococcus species phylogenetically and phenotypically. In conclusion, two novel species of the genus Lactococcus are proposed, namely Lactococcus insecticola Hs20B0-1T (=JCM 33485T=DSM 110147T) and Lactococcus hodotermopsidis Hs30E4-3T (=JCM 33486T=DSM 110148T), respectively.

A novel actinomycete strain CYP1-5T was isolated from the mountain soil sample collected from Chaiyaphum province, Thailand and its taxonomic position was clarified by using a polyphasic taxonomic approach. The chemotaxonomic properties of strain CYP1-5T were consistent within the genus Actinomadura. Cell-wall peptidoglycan of this strain contained meso-diaminopimelic acid. Galactose, madurose, and ribose were presented as the diagnostic sugars in whole-cell hydrolysates. The major menaquinone was MK-9(H6). Major cellular fatty acids were iso-C16:0 and C16:0. Phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol, and phosphatidylinositol mannoside were observed as predominant phospholipids. Based on the results of phylogenetic analyses of 16S rRNA gene sequence, strain CYP1-5T was constituent with the genus Actinomadura and was closely related to Actinomadura syzygii GKU157T (99.5%) and Actinomadura chibensis IFM 10266T (= JCM 14158T) (98.2%). The draft genome size of strain CYP1-5T was 9.30 Mb with 72.2 mol% of G + C content. Strain CYP1-5T showed ANIb values of 94.9% with A. syzygii GKU157T and 93.2% with A. chibensis JCM 14158T. Phenotypic characteristics, phylogenetic analysis and genome data support that strain CYP1-5T could be discriminated from its closest relatives, representing a novel species of the genus Actinomadura, for which the name Actinomadura decatromicini sp. nov. is proposed. The type strain is CYP1-5T (= JCM 16996T = KCTC 19916T = TISTR 2901T).

The microbiome in the hindgut of wood-feeding termites comprises various species of bacteria, archaea, and protists. This gut community is indispensable for the termite, which thrives solely on recalcitrant and nitrogen-poor wood. However, the difficulty in culturing these microorganisms has hindered our understanding of the function of each species in the gut. Although protists predominate in the termite gut microbiome and play a major role in wood digestion, very few culture-independent studies have explored the contribution of each species to digestion. Here, we report single-cell transcriptomes of four protists species comprising the protist population in worldwide pest Coptotermes formosanus. Comparative transcriptomic analysis revealed that the expression patterns of the genes involved in wood digestion were different among species, reinforcing their division of roles in wood degradation. Transcriptomes, together with enzyme assays, also suggested that one of the protists, Cononympha leidyi, actively degrades chitin and assimilates it into amino acids. We propose that C. leidyi contributes to nitrogen recycling and inhibiting infection from entomopathogenic fungi through chitin degradation. Two of the genes for chitin degradation were further revealed to be acquired via lateral gene transfer (LGT) implying the importance of LGT in the evolution of symbiosis. Our single-cell-based approach successfully characterized the function of each protist in termite hindgut and explained why the gut community includes multiple species.

An endophytic actinomycete, strain 3MP-10T, isolated from the root of Mimosa pudica was taxonomically studied based upon polyphasic approaches. This strain formed spiral spore chains on aerial mycelia. ll-Diaminopimelic acid, glucose and ribose were found in the whole-cell hydrolysates. It belonged to the genus Streptomyces and was closely related to Streptomyces zhaozhouensis DSM 42101T (98.9 %) and Streptomyces sedi JCM 16909T (98.6 %) based on 16S rRNA gene sequence analysis results. The major menaquinones were MK-10(H8), MK-10(H6) and MK-9(H8). The predominant cellular fatty acids were iso-C16 : 0, anteiso-C15 : 0 and anteiso-C17 : 0. The detected phospholipids were diphosphatidylglycerol, phosphatidylinositol mannoside, phosphatidylinositol, phosphatidylethanolamine and phosphatidylglycerol. Strain 3MP-10T had a genome size of 7.2 Mb with a genome G+C content of 73.4 mol%. Results of in silico genome-based similarity analysis revealed ANIb values of 84.94 and 84.77 %, ANIm values of 88.01 and 87.92 %, and dDDH values of 29.9 and 29.6 % when compared with S. zhaozhouensis DSM 42101T and S. sedi JCM 16909T, respectively. Based on the polyphasic approach, digital DNA–DNA relatedness and average nucleotide identity, we propose that the novel actinomycete represents a novel species, Streptomyces mimosae, with type strain 3MP-10T (=JCM 33328T=TISTR 2646T).

An anaerobic and aerotolerant bacterium, strain M12T, was isolated from the meibum of inflamed human meibomian glands. Cells of the strain was Gram-stain-positive, non-spore-forming and non-motile rods. Growth on trypticase soy agar plates supplemented with 5 % sheep blood was fastest at 30–37 °C under anaerobic conditions. The 16S rRNA gene sequence of the strain revealed that it belongs to the genus Cutibacterium with a 98.0 % similarity value to the closest species, Cutibacterium acnes . Genome analysis of the strain with type strains of the other Cutibacterium species resulted in digital DNA–DNA hybridization values of 32.3–22.3% and average nucleotide identity (OrthoANI) values of 86.7–73.6 %. Biochemical and physiological analyses using API rapid ID 32A and API Coryne kits revealed relatively low reactivity of the strain compared with C. acnes and Cutibacterium namnetense . The most abundant major cellular fatty acid was iso-C15 : 0. Fermentation end-products from glucose were propionate, lactate, succinate and acetate. The diagnostic diamino acid of the peptidoglycan was meso-diaminopimelic acid. Major menaquinones were MK-9(H4), MK-9(H2) and MK-9. The major peaks of the MALDI-TOF mass spectrometry spectrum were at 3493, 3712, 6986 and 7424 Da. The DNA G+C content was 59.9 mol%. Based on these findings, we propose a novel species, Cutibacterium modestum. The type strain of C. modestum is M12T (=JCM 33380T=DSM 109769T). On the basis of further genomic analysis, we also provide emended descriptions of Cutibacterium granulosum (Prévot 1938) Scholz and Kilian 2016 and Cutibacterium namnetense (Aubin et al. 2016) Nouioui et al. 2018.

Strain CR1-09T, an actinomycete isolated from the root of Catharanthus roseus, was taxonomically studied based upon polyphasic approaches. The isolate formed a pair of ovular to circular, smooth-surfaced spores on short sporophores alternately branched from aerial mycelia. It contained meso-diaminopimelic acid in cell wall peptidoglycans. The major menaquinones were MK-9 (H4) and MK-9 (H2). The predominant cellular fatty acids were iso-C16 : 0 and C16 : 0. The polar lipids profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, hydroxyl phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannosides, and unidentified ninhydrin positive phosphoglycolipids. Strain CR1-09T showed the highest 16S rRNA gene sequence similarity with Microbispora tritici DSM 104650T (99.5 %). Based on the polyphasic approach, DNA–DNA relatedness and average nucleotide identity (ANI), the strain is considered to represent a novel species of the genus Microbispora , for which the name Microbispora catharanthi is proposed. The type strain is strain CR1-09T (=JCM 30045T=TISTR 2273T).

A moderately thermophilic and heterotrophic bacterial strain, LAT, was isolated from microbial mats sampled at a hot spring in Nakabusa, Nagano, Japan. The cells of strain LAT were aerobic, Gram-stain-negative, non-sporulating, non-motile and rod-shaped (2.0–4.1 µm long). The formation of dense cell aggregates in liquid medium was a unique characteristic of the strain. Strain LAT grew optimally at 50°C and at pH 7.5. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that the nearest neighbour of strain LAT was Schleiferia thermophila JCM 30197T with 94.1 % sequence similarity. The draft genome sequence of strain LAT (2 671 880 bp) showed 18.0 % digital DNA-DNA hybridization, 70.9 % average nucleotide identity and 72.1 % average amino acid identity (AAI) values in comparison with the genome sequence of S. thermophila JCM 30197T (2 606 763 bp); the 16S rRNA gene sequence similarity and AAI values are lower than the cutoffs used for assignment to a separate genus. On the basis of phenotypic features, major cellular fatty acid composition, genome sequencing and phylogenetic position, a novel genus and species are proposed for strain LAT, to be named Thermaurantimonas aggregans (= JCM 31826T=DSM 106522T).

A novel actinomycete strain, Bv016T, belonging to the genus Streptomyces, was isolated from the bark of tree, Bauhinia variegata Linn., collected in Thailand. The taxonomic position of the strain was characterized by using a polyphasic approach. ll-Diaminopimelic acid, glucose, mannose, ribose and galactose were detected in its whole-cell hydrolysates. The N-acyl type of muramic acid was acetyl. The strain contained anteiso-C15 : 0, iso-C16 : 0, iso-C15 : 0 and iso-C14 : 0 as the major fatty acids and MK-9(H8), MK-9(H6) and MK-9(H4) as the major menaquinones. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside. The strain was closely related to Streptomyces griseoluteus JCM 4041T (98.4 %), Streptomyces seoulensis JCM 10116T (98.4 %) and Streptomyces recifensis JCM 4408T (98.2 %). The draft genome of Bv016T was 6.74 Mb with 5949 coding sequences with an average G+C content of 71.7 mol%. The ANIb and ANIm values of strain Bv016T were 94.1 and 95.2 %, respectively, and the digital DNA-DNA hybridization value was 60.6 % in comparison with the draft genome of S. griseoluteus JCM 4765T. The results of the taxonomic analysis suggested that strain Bv016T represented a novel species of the genus Streptomyces for which the name Streptomyces bauhiniae sp. nov. is proposed. The type strain is Bv016T (=JCM 33208T=TISTR 2645T).

Significance The DPANN superphylum is a grouping of symbiotic microorganisms categorized based on their genomic contents and a few examples of cultivation experiments. Although the genome information of DPANN archaea is increasing year by year, most of them have remained uncultivated, limiting our knowledge of these organisms. Herein, a thermoacidophilic symbiotic archaeon (ARM-1) from the DPANN superphylum was successfully cultivated and characterized. We determined its physiological, morphological, and genomic characteristics in detail and obtained experimental evidence of the symbiotic lifestyle of this archaeon. Notably, ARM-1 is a symbiotic archaeal strain that showed dependence on a range of host species in a laboratory culture. The results significantly contribute to the true understanding of the physiology and ecology of DPANN archaea., Decades of culture-independent analyses have resulted in proposals of many tentative archaeal phyla with no cultivable representative. Members of DPANN (an acronym of the names of the first included phyla Diapherotrites, Parvarchaeota, Aenigmarchaeota, Nanohaloarchaeota, and Nanoarchaeota), an archaeal superphylum composed of at least 10 of these tentative phyla, are generally considered obligate symbionts dependent on other microorganisms. While many draft/complete genome sequences of DPANN archaea are available and their biological functions have been considerably predicted, only a few examples of their successful laboratory cultivation have been reported, limiting our knowledge of their symbiotic lifestyles. Here, we investigated physiology, morphology, and host specificity of an archaeon of the phylum “Candidatus Micrarchaeota” (ARM-1) belonging to the DPANN superphylum by cultivation. We constructed a stable coculture system composed of ARM-1 and its original host Metallosphaera sp. AS-7 belonging to the order Sulfolobales. Further host-switching experiments confirmed that ARM-1 grew on five different archaeal species from three genera—Metallosphaera, Acidianus, and Saccharolobus—originating from geologically distinct hot, acidic environments. The results suggested the existence of DPANN archaea that can grow by relying on a range of hosts. Genomic analyses showed inferred metabolic capabilities, common/unique genetic contents of ARM-1 among cultivated micrarchaeal representatives, and the possibility of horizontal gene transfer between ARM-1 and members of the order Sulfolobales. Our report sheds light on the symbiotic lifestyles of DPANN archaea and will contribute to the elucidation of their biological/ecological functions.

An actinomycete strain, LCR2-06T, isolated from a lichen sample on rock collected from Chiang Rai Province (Pong Phra Bat Waterfall), Thailand, was characterized using a polyphasic approach. The strain grew at 25–45 °C, pH 6–11 and on International Streptomyces Project 2 agar plate with 5 % (w/v) NaCl. It contained meso-diaminopimelic acid as the diamino acid in whole-cell hydrolysates. Rhamnose, ribose, xylose, madurose, glucose and galactose were detected as whole-cell sugar hydrolysates. Mycolic acids were absent. The N-acyl type of muramic acid was acetyl. The strain contained C16 : 0, TBSA 10-methyl C18 : 0 and 2-hydroxy C16 : 0 as the predominant fatty acids and MK-9(H6), MK-9(H4) and MK-9(H8) as the major menaquinones. The major polar lipids were diphosphatidylglycerol, phosphatidylinositol and unidentified phospholipid. The draft genome of strain LCR2-06T was closely related to Actinomadura barringtoniae TBRC 7225T (99.2 %), Actinomadura nitritigenes NBRC 15918T (98.8 %), Actinomadura montaniterrae TISTR 2400T (98.5 %) and Actinomadura physcomitrii JCM 33455T (97.9 %). The draft genome of LCR2-06T was 11.1 Mb with 10 588 coding sequences with an average G+C content of 72.7 mol%. Results of genomic analysis revealed that the ANIb and ANIm values between strain LCR2-06T and A. montaniterrae TISTR 2400T were 90.0 and 92.0 %, respectively. The digital DNA–DNA hybridization value was 43.9 % in comparison with the draft genome of A. montaniterrae TISTR 2400T. The strain produced an antibacterial compound active against Bacillus subtilis ATCC 6633 and Kocuria rhizophila ATCC 9341. The results of taxonomic analysis suggested that strain LCR2-06T represented a novel species of the genus Actinomadura for which the name Actinomadura violacea sp. nov. is proposed. The type strain is LCR2-06T (=JCM 33065T=KCTC 49547T=NBRC 114810T=LMG 32136T=TISTR 2935T).

Two obligately anaerobic, Gram-stain-positive, rod-shaped bacteria were isolated from faecal samples of healthy humans in Japan. 16S rRNA gene sequence analysis indicated that these two strains (8CFCBH1T and 9CBH6) belonged to the genus Adlercreutzia , which is known as an equol-producing bacterium. The closest neighbours of strain 8CFCBH1T were Adlercreutzia equolifaciens subsp. equolifaciens DSM 19450T (98.6%), Adlercreutzia equolifaciens subsp. celatus do03T (98.4%), Adlercreutzia muris WCA-131-CoC-2T (96.6%), Parvibacter caecicola NR06T (96.4%), Adlercreutzia caecimuris B7T (95.3%) and Adlercreutzia mucosicola Mt1B8T (95.3%). The closest relatives to strain 9CBH6 were A. equolifaciens subsp. equolifaciens DSM 19450T (99.8%), A. equolifaciens subsp. celatus do03T (99.6%) and A. muris WCA-131-CoC-2T (96.8%). Strain 8CFCBH1T showed 22.3–53.5% digital DNA–DNA hybridization (dDDH) values with its related species. In addition, the average nucleotide identity (ANI) values between strain 8CFCBH1T and its related species ranged from 75.4 to 93.3%. On the other hand, strain 9CBH6 was considered as A. equolifaciens based on the dDDH and ANI values (>70% dDDH and >95–96% ANI). Strain 9CBH6 showed daidzein-converting activity, as expected from the result of genome analysis. The genome of strain 8CFCBH1T lacked four genes involved in equol production. Growing cells of strain 8CFCBH1T were not capable of converting daidzein. Based on the collected data, strain 8CFCBH1T represents a novel species in the genus Adlercreutzia , for which the name Adlercreutzia hattorii sp. nov. is proposed. The type strain of A. hattorii is 8CFCBH1T (=JCM 34083T=DSM 112284T).

Two actinobacteria, designated as strain LDG1-01T and LDG1-06T, were isolated from lichen samples collected in Thailand. Results of morphological characterization, chemotaxonomic studies and 16S rRNA gene analysis indicated that both strains were members of the genus Actinoplanes . MK-9(H4) was found as the major menaquinone. The major fatty acids were anteiso-C15 : 0, iso-C15 : 0, iso-C16 : 0 and anteiso-C17 : 0. Phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol were observed as the polar lipids, but differences in minor unidentified polar lipids were found between the strains. Results of comparative genome analysis based on average nucleotide identity and digital DNA–DNA hybridization calculations revealed that both strains showed values below 95 and 70 %, respectively, from each other and closely related Actinoplanes type strains. Based on data from this polyphasic study, strains LDG1-01T and LDG1-06T represent novel species of the genus Actinoplanes . The names proposed are Actinoplanes lichenicola sp. nov. (type strain, LDG1-01T (=JCM 33066T=TISTR 2982T) and Actinoplanes ovalisporus sp. nov. (type strain, LDG1-06T=JCM 33067T=TISTR 2983T).

A novel endophytic actinomycete strain AZ1-13T was isolated from roots of Azadirachta indica, and its taxonomic position was investigated using a polyphasic approach. Pairwise 16S rRNA gene sequence similarities of strain AZ1-13T and its closest species, Jishegella zingiberis PLAI1-1T and Micromonospora endophytica 202201T, were 99.7 and 99.2 %, respectively. Phylogenetic analyses of the family Micromonosporaceae based on 16S rRNA gene sequences indicated strains AZ1-13T and J. zingiberis PLAI1-1Tare located within the genus Micromonospora . The approximate genome size of the strain was 5.96 Mb with 71.9 mol% of G+C content. The strain AZ1-13T exhibited ANIb values of 87.4 % with J. zingiberis PLAI1-1T and 85.1 % with M. endophytica 202201T. Chemotaxonomic characteristics of strain AZ1-13T were consistent within the genus Micromonospora : cell-wall peptidoglycan of the strain contained meso-diaminopimelic acid; glucose, mannose, ribose and xylose are presented as the whole-cell sugars; the predominant menaquinones were MK-9(H4) and MK-9(H6); major cellular fatty acids were iso-C15 : 0, 10-methyl C17 : 0, C17 : 0, anteiso-C17 : 0 and iso-C17 : 1ω8c; diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol were detected as distinguished phospholipids. Based on phenotypic properties, phylogeny and genomic data, the strain AZ1-13T could be distinguished from its closest neighbours, representing a novel species of the genus Micromonospora , for which the name Micromonospora radicis sp. nov. is proposed. The type strain is AZ1-13T (=KCTC 39786T=NBRC 112324T=JCM 32147T = TISTR 2404T). This study also proposed that J. zingiberis is transferred to the genus Micromonospora as Micromonospora zingiberis comb. nov. (type strain PLAI1-1T=TBRC 7644T=NBRC 113144T=JCM 32592T).

A novel actinomycete, strain PA1-10T, isolated from the leaf of Phyllanthus amarus collected from Bangkok, Thailand, was characterized taxonomically using a polyphasic approach. This strain contained the characteristics consistent with those of members of the genus Nonomuraea. It formed short rugose spore chain on aerial mycelium. The diamino acid in cell wall peptidoglycan was meso-diaminopimelic acid. Galactose, glucose, madurose, mannose, and ribose were found in whole-cell hydrolysates. Predominant menaquinones were MK-9 (H2), MK-9 (H4), and MK-9 (H6). Major cellular fatty acids were iso-C16:0 and C17:0 10-methyl. Phospholipid profiles were composed of phosphatidylinositol mannoside (PIM), lyso-phosphatidylethanolamine (lyso-PE), phosphatidylethanolamine (PE), methylphosphatidylethanolamine (PME), diphosphatidylglycerol (DPG), and phosphatidylglycerol (PG). The G + C content of DNA was 71.2 mol%. Strain PA1-10T showed the highest 16S rRNA gene sequence similarity with Nonomuraea candida JCM 15928T (98.35%) and shared the same node with Nonomuraea maritima JCM 18321T in the phylogenetic tree analysis. Based on the phenotypic characteristics, DNA–DNA relatedness, and average nucleotide identity (ANI), the strain is considered to represent a novel species of the genus Nonomuraea, for which the name Nonomuraea phyllanthi is proposed. The type strain is PA1-10T (= JCM 33073T = NBRC 112774T = TISTR 2497T).

Filamentous fungi produce a variety of proteases with significant biotechnological potential and show diverse substrate specificities. Proteolytic analysis of the industrial enzyme producer Trichoderma reesei has been sparse. Therefore, we determined the substrate specificity of T. reesei secretome and its main protease Trichodermapepsin (TrAsP) up to P1 position using FRETS-25Xaa-libraries. The role of TrAsP was analyzed using T. reesei QM9414 and the deletant QM∆trasp in Avicel. We observed higher activities of CMCase, Avicelase, and Xylanase in QM∆t rasp compared to that of QM9414. Saccharification rate of cellulosic biomass also increased when using secretome of QM∆trasp but the effect was not significant due to the absence of difference in BGL activity compared to QM9414. Higher TrAsP was produced when monosaccharides were used as a carbon source compared to cellulase inducers such as Avicel and α-sophorose. These results elucidate the relationship between TrAsP and cellulase production in T. reesei and suggest a physiological role for TrAsP.

Two novel, obligately anaerobic, Gram-stain-negative, rod or coccoid-shaped bacteria, designated strains 4NBBH2T and 6FBBBH3T, were isolated from faecal samples of a healthy Japanese woman and man. The 16S rRNA gene sequence analysis showed that these strains represent a distinct lineage within the family Sutterellaceae . Strain 4NBBH2T formed a monophyletic branch between the genera Parasutterella and Sutterella , with sequence similarity to Sutterella stercoricanis CCUG 47620T (92.6 %), followed by Sutterella wadsworthensis WAL 7877 (92.4 %), Sutterella parvirubra YIT 11816T (92.1 %) and Parasutterella secunda YIT 12071T (91.8 %). Strain 6FBBBH3T was affiliated to the genus Sutterella , with highest similarity to S. stercoricanis CCUG 47620T (97.1 %), followed by S. parvirubra YIT 11816T (96.6 %) and S. wadsworthensis WAL 7877 (95.2 %). Strains 4NBBH2T and 6FBBBH3T were asaccharolytic. Analysis of fatty acids revealed that strain 4NBBH2T could be differentiated from Sutterella species (including strain 6FBBBH3T) by the presence of a low concentration of C16 : 1ω7c. The major respiratory quinones of strain 4NBBH2T were menaquinone (MK)-6 and methylmenaquinone (MMK)-6, whereas those of strain 6FBBBH3T were MK-5 and MMK-5. The G+C content of the genomic DNA of strains 4NBBH2T and 6FBBBH3T were 56.9 and 62.8 mol%, respectively. On the basis of the collected data, strain 4NBBH2T represents a novel species in a novel genus of the family Sutterellaceae , for which the name Mesosutterella multiformis gen. nov., sp. nov. is proposed. The type strain is 4NBBH2T (=JCM 32464T=DSM 106860T). We also propose a novel Sutterella species, Sutterella megalosphaeroides sp. nov., for strain 6FBBBH3T (=JCM 32470T=DSM 106861T).

Strains DS1-2T and AZ1-7, which were isolated from roots of plants, were taxonomically characterized based on polyphasic taxonomic and taxogenomic approaches. Both strains were Gram-stain-positive and filamentous bacteria which contained LL-diaminopimelic acid in cell-wall peptidoglycan and glucose and ribose in whole-cell hydrolysates. MK-9(H6), MK-10(H6), MK-9(H8), MK-10(H8) and MK-10(H4) were major menaquinones; iso-C16:0 and iso-C16:1G were predominant cellular fatty acids; diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylinositol mannoside presented as major phospholipids; and the DNA G+C contents of 73.2 mol%. Strains DS1-2T and AZ1-7 showed 97.6–98.0 % 16S rRNA gene sequence similarity, 81.0–82.0 % ANIb, 84.8–85.3 % ANIm and 22.0–23.1 % digital DDH to their related type strains: S. specialis GW41-1564T and S. hoynatensis S1412T. Comparative genomics results of these strains and their related type strains also revealed the differences and distributions of key genes associated with stress responses, environmental variables, plant interactions and bioactive metabolites. Based on the phenotypic, chemotaxonomic and genomic data, strains DS1-2T and AZ1-7 could be assigned to the novel species within the genus Streptomyces for which the name Streptomyces radicis sp. nov. is proposed. The type strain is DS1-2T (=JCM 32152T =KCTC 39738T =TISTR 2403T).

A thermoacidophilic, anaerobic, and iron- and sulfur-reducing archaeon, strain NAS-02T, was isolated from a terrestrial hot spring in Japan, as previously reported. This organism is the first non-ammonia-oxidizing isolate in the phylumThaumarchaeota. Here, we proposeConexivisphaera calidagen. nov., sp. nov. to accommodate this strain. The type strain of the type species is NAS-02T(=JCM 31663T=DSM 105898T). The values of 16S rRNA gene similarity and average amino acid identity between NAS-02Tand its closest relatives are Conexivisphaeraceaefam. nov., the orderConexivisphaeralesord. nov. and the classConexivisphaeriaclass. nov. to accommodate the novel genus.

An obligately anaerobic, Gram-positive, non-spore-forming, straight rod-shaped bacterium, designated strain 3BBH22T, was isolated from a faecal sample of a healthy Japanese woman. The 16S rRNA gene sequence analysis showed that strain 3BBH22T formed a monophyletic cluster with species in the genera Pseudoflavonifractor and Flavonifractor within the family Ruminococcaceae and had highest similarity to Pseudoflavonifractor capillosus ATCC 29799T (96.7 % sequence similarity), followed by Flavonifractor plautii ATCC 29863T (96.4 %). Acetate and butyrate were produced by strain 3BBH22T as metabolic end-products. The major cellular fatty acids were C14 : 0, C16 : 0, C18 : 1ω9c, C16 : 0 dimethyl acetal, C18 : 0 and C18 : 2ω6,9c. No respiratory quinones were detected. In contrast to F. plautii JCM 32125T, strain 3BBH22T did not degrade quercetin, one of the flavonoids. P. capillosus JCM 32126T also did not. Strain 3BBH22T was differentiated from P. capillosus JCM 32126T by its inability to hydrolyse aesculin. The G+C content of the genomic DNA was 61.2±1.0 mol%. On the basis of these data and the phylogenetic tree based on 89 proteins, strain 3BBH22T represents a novel species in a novel genus of the family Ruminococcaceae , for which the name Lawsonibacter asaccharolyticus gen. nov., sp. nov. is proposed. The type strain of L. asaccharolyticus is 3BBH22T (=JCM 32166T=DSM 106493T).

Highly thermostable β-mannanase, belonging to glycoside hydrolase family 5 subfamily 7, was purified from the culture supernatant of Talaromyces trachyspermus B168 and the cDNA of its transcript was cloned. The recombinant enzyme showed maximal activity at pH 4.5 and 85 °C. It retained more than 90 % of its activity below 60 °C. Obtaining the crystal structure of the enzyme helped us to understand the mechanism of its thermostability. An antiparallel β-sheet, salt-bridges, hydrophobic packing, proline residues in the loops, and loop shortening are considered to be related to the thermostability of the enzyme. The enzyme hydrolyzed mannans such as locust bean gum, carob galactomannan, guar gum, konjac glucomannan, and ivory nut mannan. It hydrolyzed 50.7 % of the total mannans from coffee waste, producing mannooligosaccharides. The enzyme has the highest optimum temperature among the known fungal β-mannanases and has potential for use in industrial applications.

Cellulolytic flagellated protists inhabit the hindgut of termites. They are unique and essential to termites and related wood-feeding cockroaches, enabling host feeding on cellulosic matter. Protists of two genera in the family Teranymphidae (phylum Parabasalia), Eucomonympha and Teranympha, are phylogenetically closely related and harbor intracellular endosymbiotic bacteria from the genus Treponema. In order to obtain a clearer understanding of the evolutionary history of this triplex symbiotic relationship, the molecular phylogenies of the three symbiotic partners, the Teranymphidae protists, their Treponema endosymbionts, and their host termites, were inferred and compared. Strong congruence was observed in the tree topologies of all interacting partners, implying their cospeciating relationships. In contrast, the coevolutionary relationship between the Eucomonympha protists and their endosymbionts was more complex, and evidence of incongruence against cospeciating relationships suggested frequent host switches of the endosymbionts, possibly because multiple Eucomonympha species are present in the same gut community. Similarities in the 16S rRNA and gyrB gene sequences of the endosymbionts were higher among Teranympha spp. (>99.25% and >97.2%, respectively), whereas those between Teranympha and Eucomonympha were lower (

Termite guts harbor diverse yet-uncultured bacteria, including a non-photosynthetic cyanobacterial group, the class "Melainabacteria". We herein reported the phylogenetic diversity of "Melainabacteria" in the guts of diverse termites and conducted a single-cell genome analysis of a melainabacterium obtained from the gut of the termite Termes propinquus. We performed amplicon sequencing of 16S rRNA genes from the guts of 60 termite and eight cockroach species, and detected melainabacterial sequences in 48 out of the 68 insect species, albeit with low abundances (0.02-1.90%). Most of the melainabacterial sequences obtained were assigned to the order "Gastranaerophilales" and appeared to form clusters unique to termites and cockroaches. A single-cell genome of a melainabacterium, designated phylotype Tpq-Mel-01, was obtained using a fluorescence-activated cell sorter and whole genome amplification. The genome shared basic features with other melainabacterial genomes previously reconstructed from the metagenomes of human and koala feces. The bacterium had a small genome (~1.6 Mb) and possessed fermentative pathways possibly using sugars and chitobiose as carbon and energy sources, while the pathways for photosynthesis and carbon fixation were not found. The genome contained genes for flagellar components and chemotaxis; therefore, the bacterium is likely motile. A fluorescence in situ hybridization analysis showed that the cells of Tpq-Mel-01 and/or its close relatives are short rods with the dimensions of 1.1±0.2 μm by 0.5±0.1 μm; for these bacteria, we propose the novel species, "Candidatus Gastranaerophilus termiticola". Our results provide fundamental information on "Melainabacteria" in the termite gut and expand our knowledge on this underrepresented, non-photosynthetic cyanobacterial group.

Dicationic thiolate-bridged diruthenium complexes bearing sterically bulky alkane substituents on the thiolate ligands such as [Cp*Ru(μ-SiPr)2Ru(OH2)Cp*](OTf)2 have been found to work as effective catalysts toward oxidation of molecular dihydrogen into protons and electrons in protic solvents such as water and methanol. DFT calculations indicate that the sterically bulky alkane substituent in the complex plays an important role in facilitating the reaction step of the coordination of molecular dihydrogen.

Thiolate-bridged diruthenium complexes bearing pendent ethers have been found to work as effective catalysts toward the oxidation of molecular dihydrogen into protons and electrons in water. The pendent ether moiety in the complex plays an important role to facilitate the proton transfer between the metal center and the external proton acceptor.

Propargylic substitution reactions have offered useful synthetic methods because further transformations based on the alkyne moiety in the propargylic substituted products was readily achieved to construct more complex organic compounds. A large number of works have been devoted to enantioselective propargylic substitution reactions with a variety of nucleophiles. However, successful examples of the use of alcohols as nucleophiles have been quite limited until now. To achieve utilization of aliphatic alcohols, herein we report the use of combined catalysis of a copper-pybox complex and a borinic acid. In this catalytic system, aliphatic alcohols such as benzyl alcohol derivatives were successfully applied to afford the corresponding propargylic etherified products in good yields with high enantioselectivities.

A deep-branching clade of Thaumarchaeota, conventionally called Terrestrial hot spring creanarchaeotic group (THSCG), is a missing link between thaumarchaeotic ammonia oxidizers and the deeper-branching non-ammonia oxidizers, such as Crenarchaeota and Candidatus Korarchaeota. Here, we report isolation of the first cultivated representative from the THSCG, named as NAS-02. Physiological characterization demonstrated that the isolate was a thermoacidophilic, sulfur- and iron-reducing organoheterotroph, which was supported by gene contents encoded in its complete genome. There was no evidence for ammonia oxidation by the isolate. Members in THSCG are likely thermophiles, and may play roles in degrading cell debris as a scavenger and in biogeochemical cycling of sulfur and iron in the hot environments, as suggested by the physiological characteristics of the isolate and the geographical distribution of the 16S rRNA gene sequences of THSCG in terrestrial hot springs and marine hydrothermal fields. Phylogenetic analysis suggests that the THSCG lineage represented by NAS-02 has gained the ability of sulfur reduction via horizontal gene transfer. Based on the phylogeny and physiology, we propose the name Conexivisphaera calidus gen. nov., sp. nov. to accommodate the isolate.

Previous analyses based on 16S rRNA and hsp60 genes indicated that Parolsenella catena and Libanicoccus massiliensis were closely related to each other and formed a monophyletic cluster independent of the related Olsenella species. To clarify the relationship of these two species, we determined the genome sequence of P. catena JCM 31932T and compared it with that already sequenced for L. massiliensis Marseille-P3237T. Phylogenetic trees based on the concatenated 37 single-copy ribosomal proteins or RpoB robustly supported the relationship observed in the previous studies. Digital DNA–DNA hybridization and average nucleotide identity (ANI) values between P. catena JCM 31932T and L. massiliensis Marseille-P3237T were 32.6 and 87.8 %, respectively, indicating that P. catena JCM 31932T and L. massiliensis Marseille-P3237T are independent species. Alignment fraction and ANI values between the two genomes were 0.75 and 88.84 %, respectively, thus indicating that the two species should be classified into the same genus. The number of putative orthologous genes shared between the two genomes was 1321, which was significantly larger than those (482–928) reported between L. massiliensis Marseille-P3237T and other closely related species. In addition, the genome of P. catena JCM 31932T had a high degree of synteny conservation with that of L. massiliensis Marseille-P3237T. On the basis of these findings, we propose that L. massiliensis should be reclassified as Parolsenella massiliensis comb. nov.; the type strain is Marseille-P3237T (=JCM 33000T=CCUG 71182T).

Two novel actinobacterial strains, MS1-9T and NGC1-4, were isolated from roots of Musa (ABB) cv. ‘Kluai Namwa’, collected from Chachoengsao province, and Musa (ABB) cv. ‘Kluai Chang’, from Suphan Buri province, Thailand, respectively. Comparative analysis of 16S rRNA gene (98.0 to 98.9% similarity), gyrase subunit B (gyrB) gene and whole-genome sequences emphasised that the strains MS1-9T and NGC1-4 showed closely related with Micromonospora peucetia DSM 43363T, M. krabiensis JCM 12869T and M. avicenniae DSM 45758T, respectively. Strains MS1-9T and NGC1-4 contained meso-diaminopimelic acid in cell-wall peptidoglycan. Whole-cell sugars were glucose, xylose, mannose, and ribose. The acyl type of peptidoglycan was glycolyl. MK-10(H6), MK-9(H6), and MK-10(H8) were presented as the major menaquinones. Diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, and phosphatidylinositol were detected as predominant phospholipid profiles. The major cellular fatty acids consisted of iso-C15:0, anteiso-C15:0, anteiso-C17:0, iso-C17:0 and C17:0. The DNA G + C content of strains MS1-9T and NGC1-4 were 72.2 and 72.3 mol%, respectively. Draft genome sequences indicated by ANI values and digital DNA-DNA hybridisation analysis asserted that the strains MS1-9T and NGC1-4 should be represented as a novel species within the genus Micromonospora for which the name Micromonospora musae sp. nov. is proposed. The type strain is MS1-9T (=JCM 32149T = TISTR 2659T).

“Candidatus Endomicrobium trichonymphae” (Bacteria; Elusimicrobia) is an obligate intracellular symbiont of the cellulolytic protist genus Trichonympha in the termite gut. A previous genome analysis of “Ca. Endomicrobium trichonymphae” phylotype Rs-D17 (genomovar Ri2008), obtained from a Trichonympha agilis cell in the gut of the termite Reticulitermes speratus, revealed that its genome is small (1.1 Mb) and contains many pseudogenes; it is in the course of reductive genome evolution. Here we report the complete genome sequence of another Rs-D17 genomovar, Ti2015, obtained from a different T. agilis cell present in an R. speratus gut. These two genomovars share most intact protein-coding genes and pseudogenes, showing 98.6% chromosome sequence similarity. However, characteristic differences were found in their defense systems, which comprised restriction-modification and CRISPR/Cas systems. The repertoire of intact restriction-modification systems differed between the genomovars, and two of the three CRISPR/Cas loci in genomovar Ri2008 are pseudogenized or missing in genomovar Ti2015. These results suggest relaxed selection pressure for maintaining these defense systems. Nevertheless, the remaining CRISPR/Cas system in each genomovar appears to be active; none of the “spacer” sequences (112 in Ri2008 and 128 in Ti2015) were shared whereas the “repeat” sequences were identical. Furthermore, we obtained draft genomes of three additional endosymbiotic Endomicrobium phylotypes from different host protist species, and discovered multiple, intact CRISPR/Cas systems in each genome. Collectively, unlike bacteriome endosymbionts in insects, the Endomicrobium endosymbionts of termite-gut protists appear to require defense against foreign DNA, although the required level of defense has likely been reduced during their intracellular lives.

A strain of lactic acid bacteria, designated NtB2T, isolated from the gut of the wood-feeding higher termite Nasutitermes takasagoensis, was characterized genetically and phenotypically. Strain NtB2T was related to Lactococcus lacti subsp. tructae JCM 31125T isolated from brown trout, showing 93.2 and 81.0 % similarity in 16S rRNA gene and rpoB gene sequences, respectively. Furthermore, genomic comparisons using pairwise average nucleotide identity analysis and the Genome-to-Genome Distance Calculator between strain NtB2T and L. lacti subsp. tructae JCM 31125T gave values of 81.0 and 23.2 %, respectively. Major cellular fatty acids produced by strain NtB2T were C18 : 1ω9c and C16 : 0. The cell-wall peptidoglycan type of strain NtB2T was A3α, Lys–Gly–Ser–Ala2. Based on the data presented, the isolate represents a novel species of the genus Lactococcus , for which the name Lactococcus termiticola sp. nov. is proposed. The type strain is NtB2T (=JCM 32569T=DSM 107259T).