- Volume 71, Issue 8, 2021
Volume 71, Issue 8, 2021
- Evolution, Phylogeny and Biodiversity
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Genome-based reclassification of Caldicellulosiruptor lactoaceticus and Caldicellulosiruptor kristjanssonii as later heterotypic synonyms of Caldicellulosiruptor acetigenus
More LessThe present study was carried out to re-clarify the taxonomic relationship of Caldicellulosiruptor acetigenus , Caldicellulosiruptor lactoaceticus and Caldicellulosiruptor kristjanssonii . The 16S rRNA sequence similarities between these species of the genus Caldicellulosiruptor were above the threshold values (98.65%) for bacterial species delineation. Similarly, the digital DNA–DNA hybridization and average nucleotide and amino acid identity values were greater than the thresholds for bacterial species delineation. In phylogenetic (based on 16S rRNA gene sequences) and phylogenomic trees Caldicellulosiruptor acetigenus , Caldicellulosiruptor lactoaceticus and Caldicellulosiruptor kristjanssonii clade together. The results of our analysis indicated that these three taxa are conspecific. Therefore, Caldicellulosiruptor lactoaceticus Mladenovska et al. 1997 and Caldicellulosiruptor kristjanssonii Bredholt et al. 1999 should be reclassified as later heterotypic synonyms of Caldicellulosiruptor acetigenus (Nielsen et al. 1994) Onyenwoke et al. 2006.
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Redescription and SSU rRNA gene-based phylogeny of an anaerobic ciliate, Plagiopyla ovata Kahl, 1931 (Ciliophora, Plagiopylea)
The morphology and molecular phylogeny of Plagiopyla ovata Kahl, 1931, a poorly known anaerobic ciliate, were investigated based on a population isolated from sand samples collected from the Yellow Sea coast at Qingdao, PR China. Details of the oral ciliature are documented for the first time to our knowledge and an improved species diagnosis is given. The small subunit ribosomal RNA (SSU rRNA) gene was newly sequenced and phylogenetic analyses revealed that P. ovata clusters within the monophyletic family Plagiopylidae. However, evolutionary relationships within both the family Plagiopylidae and the genus Plagiopyla remain obscure owing to undersampling, the lack of sequence data from known species and low nodal support or unstable topologies in gene trees. A key to the identification of the species of the genus Plagiopyla with validly published names is also supplied.
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Genome-based studies indicate that the Enterococcus faecium Clade B strains belong to Enterococcus lactis species and lack of the hospital infection associated markers
More LessEnterococcus lactis and the heterotypic synonym Enterococcus xinjiangensis from dairy origin have recently been identified as a novel species based on 16S rRNA gene sequence analysis. Enterococcus faecium type strain NCTC 7171T was used as the reference genome for determining E. lactis and E. faecium to be separate species. However, this taxonomic classification did not consider the diverse lineages of E. faecium , and the double nature of hospital-associated (clade A) and community-associated (clade B) isolates. Here, we investigated the taxonomic relationship among isolates of E. faecium of different origins and E. lactis , using a genome-based approach. Additional to 16S rRNA gene sequence analysis, we estimated the relatedness among strains and species using phylogenomics based on the core pangenome, multilocus sequence typing, the average nucleotide identity and digital DNA–DNA hybridization. Moreover, following the available safety assessment schemes, we evaluated the virulence profile and the ampicillin resistance of E. lactis and E. faecium clade B strains. Our results confirmed the genetic and evolutionary differences between clade A and the intertwined clade B and E. lactis group. We also confirmed the absence in these strains of virulence gene markers IS16, hylEfm and esp and the lack of the PBP5 allelic profile associated with ampicillin resistance. Taken together, our findings support the reassignment of the strains of E. faecium clade B as E. lactis .
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Taxonomic status of the species Clostridium methoxybenzovorans Mechichi et al. 1999
More LessThe taxonomic status of the species Clostridium methoxybenzovorans was assessed. The 16S rRNA gene sequence, whole-genome sequence and phenotypic characterizations suggested that the type strain deposited in the American Type Culture Collection ( C. methoxybenzovorans ATCC 700855T) is a member of the species Eubacterium callanderi . Hence, C. methoxybenzovorans ATCC 700855T cannot be used as a reference for taxonomic study. The type strain deposited in the German Collection of Microorganism and Cell Cultures GmbH (DSM 12182T) is no longer listed in its online catalogue. Also, both the 16S rRNA gene and the whole-genome sequences of the original strain SR3T showed high sequence identity with those of Lacrimispora indolis (recently reclassified from Clostridium indolis ) as the most closely related species. Analysis of the two genomes showed average nucleotide identity based on blast and digital DNA–DNA hybridization values of 98.3 and 87.9 %, respectively. Based on these results, C. methoxybenzovorans SR3T was considered to be a member of L. indolis .
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Proposal of Streptomyces aureorectus (ex Taig et al. 1969) Taig and Solovieva 1986 as a later heterotypic synonym of Streptomyces calvus Backus et al. 1957 (Approved Lists 1980) on the basis of a polyphasic taxonomic approach
More LessAs two separate genomic species, Streptomyces calvus and Streptomyces aureorectus were approved in 1980 and 1986, respectively. However, recently, it has been found that the average nucleotide identity and digital DNA–DNA hybridization values between S. calvus JCM 4326T and S. aureorectus DSM 41692T were 99.19 and 92.70 %, respectively, much higher than 95–96 and 70 % cut-off points proposed and the generally accepted species boundaries. These data indicated that they should be classified as the same genomic species. Furthermore, this result was also supported by a comprehensive comparison of phenotypic, chemotaxonomic and physio-biochemical characteristics between the two type strains. All these data indicated that S. calvus and S. aureorectus had the same taxonomic position. In accordance with the principle of priority, it is proposed that S. aureorectus is a later heterotypic synonyms of S. calvus .
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Aestuariisphingobium litorale Li et al. 2020 is a later heterotypic synonym of Chakrabartia godavariana Jani et al. 2019
More LessChakrabartia godavariana PRB40T was compared with Aestuariisphingobium litorale SYSU M10002T to examine the taxonomic relationship between the two type strains. The 16S rRNA gene sequence of C. godavariana PRB40T had high similarity (99.8 %) to that of A. litorale SYSU M10002T. The results of phylogenetic analyses based on 16S rRNA gene sequences indicated that the two strains formed a tight cluster within the genus Chakrabartia . A draft genomic comparison between the two strains revealed an average nucleotide identity of 97.3 % and a digital DNA–DNA hybridization estimate of 79.5±2.9 %, strongly indicating that the two strains represented a single species. In addition, neither strain displayed any striking differences in metabolic, physiological or chemotaxonomic features. Therefore, we propose that Aestuariisphingobium litorale is a later heterotypic synonym of Chakrabartia godavariana .
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Proposal of Lactococcus garvieae subsp. bovis Varsha and Nampoothiri 2016 as a later heterotypic synonym of Lactococcus formosensis Chen et al. 2014 and Lactococcus formosensis subsp. bovis comb. nov.
More LessCurrently, Lactococcus garvieae contains two subspecies: L. garvieae subsp. bovis and L. garvieae subsp. garvieae . In a study by Varsha and Nampoothiri, high pheS (99.7 %) and rpoA (99.6 %) sequence similarities indicated that L. garvieae subsp. bovis and Lactococcus formosensis probably have a close taxonomic relationship; low pheS (92.2 %) and rpoA (97.8 %) sequence similarities and relatively low DNA–DNA hybridization value (75.8 %) indicated that L. garvieae subsp. bovis and L. garvieae subsp. garvieae probably represent two different species. In the present study, the taxonomic relationships between L. garvieae subsp. bovis , L. garvieae subsp. garvieae and L. formosensis were re-examined based on sequence analyses of 16S rRNA, pheS, recA, rpoA and rpoB genes, average nucleotide identity (ANI), digital DNA–DNA hybridization (dDDH) values, average amino acid identity (AAI), fatty acid methyl ester analysis and phenotypic characterization. L. garvieae subsp. bovis LMG 30663T exhibited 97.3 % ANI, 78.3 % dDDH and 96.4 % AAI values to L. formosensis NBRC 109475T, higher than the threshold for species demarcation (95–96, 70 and 95–96 %, respectively), indicating that L. garvieae subsp. bovis LMG 30663T and L. formosensis NBRC 109475T belong to the same species. L. garvieae subsp. bovis LMG 30663T had 91.2 % ANI, 43.3 % dDDH and 92.9–93.0% AAI values with the type strain of L. garvieae subsp. garvieae , indicating that they represent two different species. Because L. formosensis has been proposed and validated before L. garvieae subsp. bovis , L. garvieae subsp. bovis is transferred to L. formosensis as L. formosensis subsp. bovis comb. nov. The type strain of L. formosensis subsp. bovis is BSN307T (=DSM 100577T=MCC 2824T=KCTC 21083T=LMG 30663T). The type strain of L. formosensis subsp. formosensis is 516T (=NBRC 109475T=BCRC 80576T).
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- ICSP Matters
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Emendation of General Consideration 5 and Rules 18a, 24a and 30 of the International Code of Nomenclature of Prokaryotes to resolve the status of the Cyanobacteria in the prokaryotic nomenclature
More LessFollowing the International Committee on Systematics of Prokaryotes electronic discussion and vote on proposals to resolve the status of the Cyanobacteria in the prokaryotic nomenclature, we announce here the results of the ballot. We also present the emended versions of General Consideration 5 and Rules 18a, 24a and 30, based on the outcome of the ballot, to be included in the new revision of the International Code of Nomenclature of Prokaryotes.
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- Corrigenda
Volumes and issues
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Volume 74 (2024)
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Volume 73 (2023)
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Volume 72 (2022 - 2023)
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Volume 71 (2020 - 2021)
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Volume 70 (2020)
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Volume 69 (2019)
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Volume 68 (2018)
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Volume 67 (2017)
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Volume 66 (2016)
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Volume 65 (2015)
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Volume 64 (2014)
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Volume 63 (2013)
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Volume 62 (2012)
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Volume 61 (2011)
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Volume 60 (2010)
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Volume 59 (2009)
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Volume 58 (2008)
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Volume 57 (2007)
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Volume 56 (2006)
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Volume 55 (2005)
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Volume 54 (2004)
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Volume 53 (2003)
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Volume 52 (2002)
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Volume 51 (2001)
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Volume 50 (2000)
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Volume 49 (1999)
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Volume 48 (1998)
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Volume 47 (1997)
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Volume 46 (1996)
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Volume 45 (1995)
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Volume 44 (1994)
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Volume 43 (1993)
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Volume 42 (1992)
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Volume 41 (1991)
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Volume 40 (1990)
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Volume 39 (1989)
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Volume 38 (1988)
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Volume 37 (1987)
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Volume 36 (1986)
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Volume 35 (1985)
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Volume 34 (1984)
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Volume 33 (1983)
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Volume 32 (1982)
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Volume 31 (1981)
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Volume 30 (1980)
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Volume 29 (1979)
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Volume 28 (1978)
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Volume 27 (1977)
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Volume 26 (1976)
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Volume 25 (1975)
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Volume 24 (1974)
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Volume 23 (1973)
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Volume 22 (1972)
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Volume 21 (1971)
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Volume 20 (1970)
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Volume 19 (1969)
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Volume 18 (1968)
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Volume 17 (1967)
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Volume 16 (1966)
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Volume 15 (1965)
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Volume 14 (1964)
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Volume 13 (1963)
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Volume 12 (1962)
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Volume 11 (1961)
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Volume 10 (1960)
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Volume 9 (1959)
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Volume 8 (1958)
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Volume 7 (1957)
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Volume 6 (1956)
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Volume 5 (1955)
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Volume 4 (1954)
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Volume 3 (1953)
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Volume 2 (1952)
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Volume 1 (1951)