Diversity of nonribosomal peptide synthetase and polyketide synthase gene clusters in the genus Acrocarpospora.

Acrocarpospora is a rare, recently established actinomycete genus of the family Streptosporangiaceae. In the present study, we sequenced whole genomes of the type strains of Acrocarpospora corrugate, Acrocarpospora macrocephala, and Acrocarpospora pleiomorpha to assess their potency as secondary metabolite producers; we then surveyed their nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) gene clusters. The genome sizes of A. corrugate NBRC 13972T, A. macrocephala NBRC 16266T, and A. pleiomorpha NBRC 16267T were 9.3 Mb, 12.1 Mb, and 11.8 Mb, respectively. Each genome contained 12-17 modular NRPS and PKS gene clusters. Among the 23 kinds of NRPS and PKS gene clusters identified from the three strains, eight clusters were conserved in all the strains, six were shared between A. macrocephala and A. pleiomorpha, and the remaining nine were strain-specific. We predicted the chemical structures of the products synthesized by these gene clusters based on bioinformatic analyses. Since the chemical structures are diverse, Acrocarpospora strains are considered an attractive source of diverse nonribosomal peptide and polyketide compounds.

Genome analysis-based reclassification of Streptomyces endus and Streptomyces sporocinereus as later heterotypic synonyms of Streptomyces hygroscopicus subsp. hygroscopicus.

The aim of this study was to reclarify the taxonomic relationship among Streptomyces hygroscopicus subsp. hygroscopicus, Streptomyces endus and Streptomyces sporocinereus. Whole genome shotgun sequencing was performed for the type strains of these three taxa. Average nucleotide identity and digital DNA-DNA hybridization values among the three taxa were greater than the thresholds for bacterial species delineation, indicating that they belong to the same genomospecies. In addition, the phenotypic data previously reported also support the synonymy. Therefore, S. endus and S. sporocinereus should be reclassified as later heterotypic synonyms of S. hygroscopicus subsp. hygroscopicus.

Draft genome sequence of Streptomyces sp. TP-A0867, an alchivemycin producer.

Streptomyces sp. TP-A0867 (=NBRC 109436) produces structurally complex polyketides designated alchivemycins A and B. Here, we report the draft genome sequence of this strain together with features of the organism and assembly, annotation, and analysis of the genome sequence. The 9.9 Mb genome of Streptomyces sp. TP-A0867 encodes 8,385 putative ORFs, of which 7,232 were assigned with COG categories. We successfully identified a hybrid polyketide synthase (PKS)/ nonribosomal peptide synthetase (NRPS) gene cluster that could be responsible for alchivemycin biosynthesis, and propose the biosynthetic pathway. The alchivemycin biosynthetic gene cluster is also present in Streptomyces rapamycinicus NRRL 5491T, Streptomyces hygroscopicus subsp. hygroscopicus NBRC 16556, and Streptomyces ascomycinicus NBRC 13981T, which are taxonomically highly close to strain TP-A0867. This study shows a representative example that distribution of secondary metabolite genes is correlated with evolution within the genus Streptomyces.

Draft Genome Sequence of Streptomyces hygroscopicus subsp. hygroscopicus NBRC 16556.

Here, we report the draft genome sequence of strain NBRC 16556, deposited as Streptomyces hygroscopicus subsp. hygroscopicus into the NBRC culture collection. An average nucleotide identity analysis confirmed that the taxonomic identification is correct. The genome sequence will serve as a valuable reference for genome mining to search new secondary metabolites.

Genome-based analysis of non-ribosomal peptide synthetase and type-I polyketide synthase gene clusters in all type strains of the genus Herbidospora.

BACKGROUND: The genus Herbidospora comprises actinomycetes belonging to the family Streptosporangiaceae and currently contains five recognized species. Although other genera of this family often produce bioactive secondary metabolites, Herbidospora strains have not yet been reported to produce secondary metabolites. In the present study, to assess their potential as secondary metabolite producers, we sequenced the whole genomes of the five type strains and searched for the presence of their non-ribosomal peptide synthetase (NRPS) and type-I polyketide synthase (PKS) gene clusters. These clusters are involved in the major secondary metabolite-synthetic pathways in actinomycetes. RESULTS: The genome sizes of Herbidospora cretacea NBRC 15474(T), Herbidospora mongoliensis NBRC 105882(T), Herbidospora yilanensis NBRC 106371(T), Herbidospora daliensis NBRC 106372(T) and Herbidospora sakaeratensis NBRC 102641(T) were 8.3, 9.0, 7.9, 8.5 and 8.6 Mb, respectively. They contained 15-18 modular NRPS and PKS gene clusters. Thirty-two NRPS and PKS pathways were identified, among which 9 pathways were conserved in all 5 strains, 8 were shared in 2-4 strains, and the remaining 15 were strain-specific. We predicted the chemical backbone structures of non-ribosomal peptides and polyketides synthesized by these gene clusters, based on module number and domain organization of NRPSs and PKSs. The relationship between 16S rRNA gene sequence-based phylogeny of the five strains and the distribution of their NRPS and PKS gene clusters were also discussed. CONCLUSIONS: The genomes of Herbidospora strains carry as many NRPS and PKS gene clusters, whose products are yet to be isolated, as those of Streptomyces. Herbidospora members should synthesize large and diverse metabolites, many of whose chemical structures are yet to be reported. In addition to those conserved within this genus, each strain possesses many strain-specific gene clusters, suggesting the diversity of these pathways. This diversity could be accounted for by genus-level vertical inheritance and recent acquisition of these gene clusters during evolution. This genome analysis suggested that Herbidospora strains are an untapped and attractive source of novel secondary metabolites.

Proposal of nine novel species of the genus Lysinimicrobium and emended description of the genus Lysinimicrobium.

Thirteen novel Gram-stain-positive bacteria were isolated from various samples collected from mangrove forests in Japan, and their taxonomic positions were investigated by a polyphasic approach. Phylogenetic analyses based on 16S rRNA gene sequence comparisons showed that the 13 isolates formed a single clade with Lysinimicrobium mangrovi HI08-69T, with a similarity range of 97.6-99.5 %. The peptidoglycan of the isolates was of the A4α type with an interpeptide bridge comprising Ser-Glu and an l-Ser residue at position 1 of the peptide subunit. The predominant menaquinone was demethylmenaquinone DMK-9(H4) and the major fatty acid was anteiso-C15 : 0. These chemotaxonomic characteristics corresponded to those of the genus Lysinimicrobium. On the basis of the phenotypic and phylogenetic data, along with average nucleotide identity values among the isolates, we concluded that the 13 isolates should be assigned to the following nine novel species of the genus Lysinimicrobium: Lysinimicrobium aestuarii sp. nov. (type strain HI12-104T = NBRC 109392T = DSM 28144T), Lysinimicrobium flavum sp. nov. (type strain HI12-45T = NBRC 109391T = DSM 28150T), Lysinimicrobium gelatinilyticum sp. nov. (type strain HI12-44T = NBRC 109390T = DSM 28149T), Lysinimicrobium iriomotense sp. nov. (type strain HI12-143T = NBRC 109399T = DSM 28146T), Lysinimicrobium luteum sp. nov. (type strain HI12-123T = NBRC 109395T = DSM 28147T), Lysinimicrobium pelophilum sp. nov. (type strain HI12-111T = NBRC 109393T = DSM 28148T), Lysinimicrobium rhizosphaerae sp. nov. (type strain HI12-135T = NBRC 109397T = DSM 28152T), Lysinimicrobium soli sp. nov. (type strain HI12-122T = NBRC 109394T = DSM 28151T) and Lysinimicrobium subtropicum sp. nov. (type strain HI12-128T = NBRC 109396T = DSM 28145T). In addition, an emended description of the genus Lysinimicrobium is proposed.

Complete genome sequence of Selenomonas ruminantium subsp. lactilytica will accelerate further understanding of the nature of the class Negativicutes.

Selenomonas ruminantium subsp. lactilytica, a strictly anaerobic ruminal bacterium, possesses typical Gram-negative cell surface structure comprising cytoplasmic membrane, peptidoglycan layer and outer membrane, whereas its 16S rRNA-based taxonomy shows that the bacteria belongs to Gram-positive Firmicutes. Complete genome analysis showed that genes or gene clusters involved in Gram-negative cell structure were scattered in the S. ruminantium genome, and might provide the new insight of phylogenetic relationship between the bacterium and other bacterial species.

Draft genome sequences of eight type strains of the genus demequina.

Here, we report the draft genome sequences of the type strains of Demequina aestuarii, Demequina aurantiaca, Demequina flava, Demequina globuliformis, Demequina lutea, Demequina oxidasica, Demequina salsinemoris, and Demequina sediminicola. The genome sequences presented here will facilitate taxonomical, ecological, and functional studies of members of the genus Demequina.

Draft Genome Sequence of Streptomyces albus Strain NBRC 13014T, the Type Species of the Genus Streptomyces.

Streptomyces albus is the type species of the genus Streptomyces. Here, we report the draft genome sequence of S. albus strain NBRC 13014(T). The genome contains at least seven orphan polyketide synthase and nonribosomal peptide synthetase gene clusters. The genome sequence will also serve as a valuable reference for Streptomyces taxonomy.

Draft genome sequences of six type strains of the genus streptacidiphilus.

Members of the genus Streptacidiphilus are acidophilic actinomycetes with streptomycete-like features. Here, we report the draft genome sequences of the type strains of Streptacidiphilus albus, Streptacidiphilus anmyonensis, Streptacidiphilus carbonis, Streptacidiphilus jiangxiensis, Streptacidiphilus melanogenes, and Streptacidiphilus neutrinimicus. These genome sequences will serve as valuable references for understanding their taxonomic relationships, genetic characteristics, and potentials for industry.

Draft Genome Sequence of Lysinimicrobium mangrovi NBRC 105856T, Isolated from the Rhizosphere of a Mangrove.

Here, we report the draft genome sequence of the only species of the genus Lysinimicrobium, Lysinimicrobium mangrovi NBRC 105856(T), isolated from the rhizosphere of a mangrove. The first genomic sequence of this genus and species presented here will facilitate taxonomical, ecological, and functional studies of this rare actinobacterial group.

Genome-wide survey of polyketide synthase and nonribosomal peptide synthetase gene clusters in Streptomyces turgidiscabies NBRC 16081.

Although members of the genus Streptomyces are useful producers of secondary metabolites, Streptomyces turgidiscabies, a cause of potato scab, has not been investigated for this purpose. To examine the potential of S. turgidiscabies as a secondary metabolite producer, its polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) gene clusters, conferring major biosynthetic pathways in actinomycetes, were surveyed using whole genome analysis of S. turgidiscabies NBRC 16081. This strain possessed seventeen PKS and NRPS gene clusters composed of two type-I PKS, two type-II PKS, seven NRPS, and six PKS/NRPS hybrid clusters. Abundance of these gene clusters was not only comparable to those of industrially useful strains such as S. avermitilis MA-4680 and S. griseus subsp. griseus NBRC 13350, but also superior to those of genetically well-studied S. coelicolor A3(2) and potato scab-causing S. scabiei 87.22. Remarkably, its PKS/NRPS gene clusters were more diverse in their module organization than those of other Streptomyces strains, although it possessed the lowest number of type-I PKS gene clusters. Our results suggest that S. turgidiscabies, unlike S. scabiei, harbors considerable genetic potential for producing diverse polyketide and peptide compounds.

Complete genome sequence of Oscillibacter valericigenes Sjm18-20(T) (=NBRC 101213(T)).

Oscillibacter valericigenes is a mesophilic, strictly anaerobic bacterium belonging to the clostridial cluster IV. Strain Sjm18-20(T) (=NBRC 101213(T) =DSM 18026(T)) is the type strain of the species and represents the genus Oscillibacter Iino et al. 2007. It was isolated from the alimentary canal of a Japanese corbicula clam (Corbicula japonica) collected on a seacoast in Shimane Prefecture in Japan. Phylogenetically, strain Sjm18-20(T) is closest to uncultured bacteria in digestive tracts, including the enriched cells thought to represent Oscillospira guilliermondii Chatton and Perard 1913. The isolated phylogenetic position and some distinct characteristics prompted us to determine the complete genome sequence. The 4,410,036 bp chromosome and the 60,586 bp plasmid were predicted to encode a total of 4,723 protein-coding genes.

Complete genome sequence of Sphingobium sp. strain SYK-6, a degrader of lignin-derived biaryls and monoaryls.

Sphingobium sp. strain SYK-6 is able to grow on an extensive variety of lignin-derived biaryls and monoaryls, and the catabolic genes for these compounds are useful for the production of industrially valuable metabolites from lignin. Here we report the complete nucleotide sequence of the SYK-6 genome which consists of the 4,199,332-bp-long chromosome and the 148,801-bp-long plasmid.

Genomic organization and genomic structural rearrangements of Sphingobium japonicum UT26, an archetypal γ-hexachlorocyclohexane-degrading bacterium.

The complete genome sequencing of a γ-hexachlorocyclohexane-degrading strain, Sphingobium japonicum UT26, revealed that the genome consists of two circular chromosomes [with sizes of 3.5 Mb (Chr1) and 682kb (Chr2)], a 191-kb large plasmid (pCHQ1), and two small plasmids with sizes of 32 and 5kb. The lin genes are dispersed on Chr1, Chr2, and pCHQ1. Comparison of the UT26 genome with those of other sphingomonad strains demonstrated that the "specific"lin genes for conversion of γ-HCH to ß-ketoadipate (linA, linB, linC, linRED, and linF) are located on the DNA regions unique to the UT26 genome, suggesting the acquisition of these lin genes by horizontal transfer events. On the other hand, linGHIJ and linKLMN are located on the regions conserved in the genomes of sphingomonads, suggesting that the linGHIJ-encoded ß-ketoadipate pathway and the LinKLMN-type ABC transporter system are involved in core functions of sphingomonads. Based on these results, we propose a hypothesis that UT26 was created by recruiting the specific lin genes into a strain having core functions of sphingomonads. Most of the specific lin genes in UT26 are associated with IS6100. Our analysis of spontaneous linA-, linC-, and linRED-deletion mutants of UT26 revealed the involvement of IS6100 in their deduced genome rearrangements. These facts strongly suggest that IS6100 plays important roles both in the dissemination of the specific lin genes and in the genome rearrangements.

Monitoring and characterization of oseltamivir-resistant pandemic (H1N1) 2009 virus, Japan, 2009-2010.

To monitor and characterize oseltamivir-resistant (OR) pandemic (H1N1) 2009 virus with the H275Y mutation, we analyzed 4,307 clinical specimens from Japan by neuraminidase (NA) sequencing or inhibition assay; 61 OR pandemic (H1N1) 2009 viruses were detected. NA inhibition assay and M2 sequencing indicated that OR pandemic (H1N1) 2009 virus was resistant to M2 inhibitors, but sensitive to zanamivir. Full-genome sequencing showed OR and oseltamivir-sensitive (OS) viruses had high sequence similarity, indicating that domestic OR virus was derived from OS pandemic (H1N1) 2009 virus. Hemagglutination inhibition test demonstrated that OR and OS pandemic (H1N1) 2009 viruses were antigenically similar to the A/California/7/2009 vaccine strain. Of 61 case-patients with OR viruses, 45 received oseltamivir as treatment, and 10 received it as prophylaxis, which suggests that most cases emerged sporadically from OS pandemic (H1N1) 2009, due to selective pressure. No evidence of sustained spread of OR pandemic (H1N1) 2009 was found in Japan; however, 2 suspected incidents of human-to-human transmission were reported.

Whole-genome analysis of Salmonella enterica serovar Typhimurium T000240 reveals the acquisition of a genomic island involved in multidrug resistance via IS1 derivatives on the chromosome.

Salmonella enterica serovar Typhimurium is frequently associated with life-threatening systemic infections, and the recent global emergence of multidrug resistance in S. enterica isolates from agricultural and clinical settings has raised concerns. In this study, we determined the whole-genome sequence of fluoroquinolone-resistant S. enterica serovar Typhimurium T000240 strain (DT12) isolated from human gastroenteritis in 2000. Comparative genome analysis revealed that T000240 displays high sequence similarity to strain LT2, which was originally isolated in 1940, indicating that progeny of LT2 might be reemerging. T000240 possesses a unique 82-kb genomic island, designated as GI-DT12, which is composed of multidrug resistance determinants, including a Tn2670-like composite transposon (class 1 integron [intI1, bla(oxa-30), aadA1, qacEΔ1, and sul1], mercury resistance proteins, and chloramphenicol acetyltransferase), a Tn10-like tetracycline resistance protein (tetA), the aerobactin iron-acquisition siderophore system (lutA and lucABC), and an iron transporter (sitABCD). Since GI-DT12 is flanked by IS1 derivatives, IS1-mediated recombination likely played a role in the acquisition of this genomic island through horizontal gene transfer. The aminoglycoside-(3)-N-acetyltransferase (aac(3)) gene and a class 1 integron harboring the dfrA1 gene cassette responsible for gentamicin and trimethoprim resistance, respectively, were identified on plasmid pSTMDT12_L and appeared to have been acquired through homologous recombination with IS26. This study represents the first characterization of the unique genomic island GI-DT12 that appears to be associated with possible IS1-mediated recombination in S. enterica serovar Typhimurium. It is expected that future whole-genome studies will aid in the characterization of the horizontal gene transfer events for the emerging S. enterica serovar Typhimurium strains.

Genome sequence of Kitasatospora setae NBRC 14216T: an evolutionary snapshot of the family Streptomycetaceae.

Kitasatospora setae NBRC 14216(T) (=KM-6054(T)) is known to produce setamycin (bafilomycin B1) possessing antitrichomonal activity. The genus Kitasatospora is morphologically similar to the genus Streptomyces, although they are distinguishable from each other on the basis of cell wall composition and the 16S rDNA sequence. We have determined the complete genome sequence of K. setae NBRC 14216(T) as the first Streptomycetaceae genome other than Streptomyces. The genome is a single linear chromosome of 8,783,278 bp with terminal inverted repeats of 127,148 bp, predicted to encode 7569 protein-coding genes, 9 rRNA operons, 1 tmRNA and 74 tRNA genes. Although these features resemble those of Streptomyces, genome-wide comparison of orthologous genes between K. setae and Streptomyces revealed smaller extent of synteny. Multilocus phylogenetic analysis based on amino acid sequences unequivocally placed K. setae outside the Streptomyces genus. Although many of the genes related to morphological differentiation identified in Streptomyces were highly conserved in K. setae, there were some differences such as the apparent absence of the AmfS (SapB) class of surfactant protein and differences in the copy number and variation of paralogous components involved in cell wall synthesis.