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The genus Jannaschia is one of the representatives of aerobic anoxygenic phototrophic (AAP) bacteria, which is a strictly aerobic bacterium, producing a photosynthetic pigment bacteriochlorophyll (BChl) a. However, a part of the genus Jannaschia members have not been confirmed the photosynthetic ability. The partly presence of the ability in the genus Jannaschia could suggest the complexity of evolutionary history for anoxygenic photosynthesis in the genus, which is expected as gene loss and/or horizontal gene transfer. Here a novel AAP bacterium designated as strain AI_62 T (= DSM 115720  T  = NBRC 115938  T ), was isolated from coastal seawater around a fish farm in the Uwa Sea, Japan. Its closest relatives were identified as Jannaschia seohaensis SMK-146  T (95.6% identity) and J. formosa 12N15 T (94.6% identity), which have been reported to produce BChl a. The genomic characteristic of strain AI_62 T clearly showed the possession of the anoxygenic photosynthesis related gene sets. This could be a useful model organism to approach the evolutionary mystery of anoxygenic photosynthesis in the genus Jannaschia. Based on a comprehensive consideration of both phylogenetic and phenotypic characteristics, we propose the classification of a novel species within the genus Jannaschia, designated as Jannaschia pagri sp. nov. The type strain for this newly proposed species is AI_62 T (= DSM 115720  T  = NBRC 115938  T )., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Strain KK2020170 T , a Gram-stain negative, yellow colony-forming bacterium, was isolated from surface seawater sampled in Kojima Bay, Okayama, Japan. Phylogenetic analysis based on the 16S rRNA gene revealed that strain KK2020170 T belongs to the genus Flavobacterium, with Flavobacterium haoranii LQY-7 T (98.1% similarity) being its closest relative, followed by Flavobacterium sediminis MEBiC07310 T (96.9%) and Flavobacterium urocaniciphilum YIT 12746 T (96.0%). Whole-genome shotgun sequencing showed that strain KK2020170 T , when paralleled with F. haoranii LQY-7  T , had 81.3% average nucleotide identity, and 24.6% in silico DNA-DNA hybridization values, respectively. The DNA G + C content of strain KK2020170 T was 31.1 mol%. The most abundant fatty acids (> 10%) of strain KK2020170 T were iso-C15: 0, iso-C17: 0 3-OH and iso-C15: 1 G. The dominant respiratory quinone of the strain was menaquinone MK-6. Based on the phylogenetic and phenotypic analysis results, we propose that strain KK2020170 T represents a novel species, for which the name Flavobacterium okayamense sp. nov. has been proposed. The type strain is KK2020170 T (= ATCC TSD-280  T  = NBRC 115344  T )., (© 2023. The Author(s).)

Rhizobiales bacterium strain IZ6 is a novel filterable bacterium that was isolated from a suspension filtrate (<0.22 µm) of soil collected in Shimane Prefecture, western Japan. Additional closely related isolates were recovered from filterable fractions of terrestrial environmental samples collected from other places in Japan; the Gobi Desert, north-central China; and Svalbard, Arctic Norway. These findings indicate a wide distribution of this lineage. This study reports the cell variation and genomic structure of IZ6. When cultured at lower temperatures (4 °C and 15 °C), this strain contained ultra-small cells and cell-like particles in the filtrate. PacBio sequencing revealed that this chromosome (3,114,641 bp) contained 3150 protein-coding, 51 tRNA, and three rRNA genes. IZ6 showed low 16S rRNA gene sequence identity (<97%) and low average nucleotide identity (<76%) with its closest known relative, Flaviflagellibacter deserti . Unlike the methylotrophic bacteria and nitrogen-fixing bacteria in related genera, there were no genes that encoded enzymes for one-carbon-compound utilization and nitrogen fixation in the IZ6 genome; the genes related to nitrate and nitrite reductase are retained and those related to the cell membrane function tend to be slightly enriched in the genome. This genomic information helps elucidate the eco-physiological function of a phenotypically heterogeneous and diverse Rhizobiales group.

Eight strains characterised as Gram-stain-positive, non-spore-forming and non-motile rods were isolated from samples collected from stone chambers of the Takamatsuzuka and Kitora tumuli in Asuka village, Nara Prefecture, Japan. Among them, one strain, T7528-3-6bT, was shown to form a novel lineage within the genus Microbacterium. The most closely phylogenetically related species to T7528-3-6bT was Microbacterium panaciterrae, with 97.8 % sequence similarity. The major isoprenoid quinones of T7528-3-6bT were MK-12, MK-13 and MK-11. The predominant cellular fatty acids for this isolate were anteiso-C15 : 0, anteiso-C17 : 0, iso-C16 : 0 and iso-C15 : 0. The diagnostic diamino acid of the peptidoglycan of this isolate was ornithine. Major polar lipids of the isolate were phosphatidylglycerol, diphosphatidylglycerol and an unknown glycolipid. The G+C content of the genomic DNA of this isolate was 70.1 mol%. On the basis of the results of physiological, biochemical and chemotaxonomic tests and molecular phylogenetic analysis, T7528-3-6bT is considered to represent a novel species of the genus Microbacterium, for which the name M. tumbae sp. nov. has been proposed. The type strain is T7528-3-6bT (=JCM 28836T=NCIMB 15039T). The results of comparisons of both phenotypic and genotypic (16S rRNA gene sequence) characteristics indicated that the remaining seven isolates were very closely related to Microbacterium shaanxiense. Although the sequence similarity between the two was 99.2 %, further detailed multifaceted comparisons are needed to determine their accurate taxonomic assignment.

Microbial outbreaks and related biodeterioration problems have affected the 1300-year-old multicolor (polychrome) mural paintings of the special historic sites Takamatsuzuka Tumulus (TT) and Kitora Tumulus (KT). Those of TT are designated as a national treasure. The microbiomes of these tumuli, both located in Asuka village, Nara, Japan, are critically reviewed as the central subject of this report. Using culture-dependent methods (conventional isolation and cultivation), we conducted polyphasic studies of the these microbial communities and identified the major microbial colonizers (Fusarium spp., Trichoderma spp., Penicillium spp., dark Acremonium spp., novel Candida yeast spp., Bacillus spp., Ochrobactrum spp., Stenotrophomonas tumulicola, and a few actinobacterial genera) and noteworthy microbial members (Kendrickiella phycomyces, Cephalotrichum verrucisporum (≡Doratomyces verrucisporus), Sagenomella striatispora, Sagenomella griseoviridis, two novel Cladophialophora spp., Burgoa anomala, one novel species Prototheca tumulicola, five novel Gluconacetobacter spp., three novel Bordetella spp., and one novel genus and species Krasilnikoviella muralis) involved in the biodeterioration of mural paintings, plaster walls, and stone chamber interiors. In addition, we generated microbial community data from TT and KT samples using culture-independent methods (molecular biological methods, including PCR-DGGE, clone libraries, and pyrosequence analysis). These data are comprehensively presented, in contrast to those derived from culture-dependent methods. Furthermore, the microbial communities detected using both methods are analytically compared, and, as a result, the complementary roles of these methods and approaches are highlighted. In related contexts, knowledge of similar biodeterioration problems affecting other prehistoric cave paintings, mainly at Lascaux in France and Altamira in Spain, are referred to and commented upon. Based on substrate preferences (or ecological grouping) and mapping (plotting detection sites of isolates), we speculate on the possible origins and invasion routes whereby the major microbial colonizers invaded the TT stone chamber interior. Finally, concluding remarks, lessons, and future perspectives based on our microbiological surveys of these ancient tumuli, and similar treasures outside of Japan, are briefly presented. A list of the microbial taxa that have been identified and fully or briefly described by us as known and novel taxa for TT and KT isolates since 2008 is presented in Supplementary Materials.

A Gram-stain-positive, facultatively anaerobic actinomycete, designated strain T6220-5-2bT, was isolated from a sample taken from a mouldy spot on the surface of a mural painting (the white tiger, Byakko) inside the stone chamber of Takamatsuzuka Tumulus in Asuka village, Nara Prefecture, Japan. Based on 16S rRNA gene sequence analysis of the isolate, it was closely related to the genus Promicromonospora, but formed of a novel lineage within the family Promicromonosporaceae. The closest related species to strain T6220-5-2bT was Promicromonospora flava, with which it shared 99.1 % 16S rRNA gene sequence similarity. The isoprenoid quinone systems were menaquinones MK-9(H2), MK-9(H0) and MK-9(H4). The predominant cellular fatty acids for the isolate were anteiso-C15 : 0 and iso-C15 : 0. The peptidoglycan contained glutamic acid, aspartic acid, alanine and lysine, with the last named being the diagnostic diamino acid. The cell-wall acyl type was acetyl. The major polar lipids of the isolate were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol, phosphatidylinositolmannoside, two unknown phospholipids and an unknown phosphoglycolipid. Whole-cell sugars of the isolate were galactose, glucose and ribose. The DNA G+C content of the genomic DNA was 75.2 mol%. Based on the results of phylogenetic, physiological and biochemical analyses and DNA-DNA hybridization experiments, the isolate was considered to represent a novel species of a new genus in the family Promicromonosporaceae, for which the name Krasilnikoviella muralis gen. nov., sp. nov. is proposed. The type strain of Krasilnikoviella muralis is T6220-5-2bT (=JCM 28789T=NCIMB 15040T). The reclassification of Promicromonospora flava as Krasilnikoviella flava comb. nov. is also proposed with the emended description of this species.

During investigation of the biological contamination of the 1300-year-old mural paintings and plaster walls inside the stone chambers of the Takamatsuzuka and Kitora Tumuli (TT and KT) in Asuka-mura, Nara Prefecture, Japan, the identity of 17 bacterial isolates from blackish mouldy spots and viscous gels (biofilms) collected from both tumuli (16 isolates from TT and one from KT) during our 2005-2007 microbiological survey was systematically elucidated. One cluster of the major bacterial isolates was assigned to the genus Stenotrophomonas (class Gammaproteobacteria ) by phylogenetic analysis of the 16S rRNA gene sequences. These isolates were divided into two groups A and B. Group A comprised 15 TT isolates that took a phylogenetic position near Stenotrophomonas chelatiphaga LPM-5 T . Based on our analysis of the phenotypic (cultural, morphological, physiological and chemotaxonomic) characteristics and genotypic/molecular characteristics (DNA base composition, DNA-DNA relatedness, and 16S rRNA and gyrB gene sequences), the novel species name Stenotrophomonas tumulicola sp. nov. is proposed for the group A isolates with the type strain T5916-2-1b T ( = JCM 30961 T  = NCIMB 15009 T ). Group B, which contained only one TT and one KT isolate, was closely related to [ Pseudomonas ] geniculata , [ P .] hibiscicola , [ P .] beteli , Stenotrophomonas maltophilia and Stenotrophomonas pavanii . The two isolates were genotypically and phenotypically assignable to S. maltophilia .

Ten strains of Gram-stain-negative, non-spore-forming, non-motile coccobacilli were isolated from the plaster wall surface of 1300-year-old mural paintings inside the stone chamber of the Takamatsuzuka tumulus in Asuka village (Asuka-mura), Nara Prefecture, Japan. Based on 16S rRNA gene sequence analysis of the isolates, they belonged to the proteobacterial genus Bordetella (class Betaproteobacteria) and could be separated into three groups representing novel lineages within the genus Bordetella. Three isolates were selected, one from each group, and identified carefully using a polyphasic approach. The isolates were characterized by the presence of Q-8 as their major ubiquinone system and C16 : 0 (30.0-41.8 %), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c; 10.1-27.0 %) and C17 : 0 cyclo (10.8-23.8 %) as the predominant fatty acids. The major hydroxy fatty acids were C12 : 0 2-OH and C14 : 0 2-OH. The DNA G+C content was 59.6-60.0 mol%. DNA-DNA hybridization tests confirmed that the isolates represented three separate novel species, for which the names Bordetella muralis sp. nov. (type strain T6220-3-2bT = JCM 30931T = NCIMB 15006T), Bordetella tumulicola sp. nov. (type strain T6517-1-4bT = JCM 30935T = NCIMB 15007T) and Bordetella tumbae sp. nov. (type strain T6713-1-3bT = JCM 30934T = NCIMB 15008T) are proposed. These results support previous evidence that members of the genus Bordetella exist in the environment and may be ubiquitous in soil and/or water.

A phylogenetically novel proteobacterium, strain Shr3(T), was isolated from sand gravels collected from the eastern margin of the Sahara Desert. The isolation strategy targeted bacteria filterable through 0.2-µm-pore-size filters. Strain Shr3(T) was determined to be a Gram-negative, aerobic, non-motile, filamentous bacterium. Oxidase and catalase reactions were positive. Strain Shr3(T) showed growth on R2A medium, but poor or no growth on nutrient agar, trypticase soy agar and standard method agar. The major isoprenoid quinone was menaquinone-7. The dominant cellular fatty acids detected were C16:1ω5c and C16:0, and the primary hydroxy acid present was C12:0 3-OH. The DNA G+C content was 54.0 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain Shr3(T) was affiliated with an uncultivated lineage of the phylum Proteobacteria; the nearest known type strain, with 83% sequence similarity, was Desulfomicrobium orale DSM 12838(T) in the class Deltaproteobacteria. The isolate and closely related environmental clones formed a novel class-level clade in the phylum Proteobacteria with high bootstrap support (96-99%). Based on these results, the novel class Oligoflexia classis nov. in the phylum Proteobacteria and the novel genus and species Oligoflexus tunisiensis gen. nov., sp. nov. are proposed for strain Shr3(T), the first cultivated representative of the Oligoflexia. The type strain of Oligoflexus tunisiensis is Shr3(T) ( = JCM 16864(T) = NCIMB 14846(T)). We also propose the subordinate taxa Oligoflexales ord. nov. and Oligoflexaceae fam. nov. in the class Oligoflexia., (© 2014 IUMS.)

Ten strains of Gram-stain-negative, rod-shaped, non-spore-forming bacteria were isolated from the burial mound soil collected before the dismantling and samples collected during the dismantling work on the Takamatsuzuka Tumulus in Asuka village, Nara Prefecture, Japan in 2007. On the basis of the 16S rRNA gene sequence analysis of the isolates, they were accommodated in the genus Gluconacetobacter (class Alphaproteobacteria) and can be separated into four groups within the cluster containing the genus Gluconacetobacter. One of the groups demonstrated a phylogenetic position identical to that of Gluconacetobacter asukensis, which was isolated from small holes on plaster walls of the stone chamber interior of Kitora Tumulus in Asuka village, Nara Prefecture, Japan. The remaining three groups consisted of novel lineages within the genus Gluconacetobacter. A total of four isolates were selected from each group and carefully identified using a polyphasic approach. The isolates were characterized on the basis of their possessing Q-10 as the major ubiquinone system and C18 : 1ω7c (58.5-65.2 %) as the predominant fatty acid. A DNA-DNA hybridization test was used to determine that the three lineages represented novel species, for which the names Gluconacetobacter tumulisoli sp. nov., Gluconacetobacter takamatsuzukensis sp. nov. and Gluconacetobacter aggeris sp. nov. are proposed. The type strains are T611xx-1-4a(T) ( = JCM 19097(T) = NCIMB 14861(T)), T61213-20-1a(T) ( = JCM 19094(T) = NCIMB 14859(T)) and T6203-4-1a(T) ( = JCM 19092(T) = NCIMB 14860(T)), respectively.

Six Gram-negative, rod-shaped, non-spore-forming bacterial strains were isolated from small holes on plaster walls of the stone chamber interior of the Kitora Tumulus in Asuka village, Nara Prefecture, Japan. These were investigated by means of a polyphasic approach. All the isolates were strictly aerobic and motile by peritrichous flagella. Phylogenetic trees generated based on 16S rRNA gene sequences identified two novel lineages (comprising five isolates and one isolate, respectively) within the genus Gluconacetobacter. The isolates were characterized by having Q-10 as the major ubiquinone system and C(18:1)ω7c (58.7-63.1% of the total) as the predominant fatty acid. DNA-DNA hybridization experiments endorsed the species rank for the two lineages, for which the names Gluconacetobacter tumulicola sp. nov. (type strain K5929-2-1b(T) = JCM 17774(T) = NCIMB 14760(T)) and Gluconacetobacter asukensis sp. nov. (type strain K8617-1-1b(T) = JCM 17772(T) = NCIMB 14759(T)) are proposed.