scholarly journals Morphology of obligate ectosymbionts reveals Paralaxus gen. nov., a new circumtropical genus of marine stilbonematine nematodes

2019 ◽  
Author(s):  
Florian Scharhauser ◽  
Judith Zimmermann ◽  
Jörg A. Ott ◽  
Nikolaus Leisch ◽  
Harald Gruber-Vodicka

AbstractStilbonematinae are a subfamily of conspicuous marine nematodes, distinguished by a coat of sulphur-oxidizing bacterial ectosymbionts on their cuticle. As most nematodes, the worm hosts have a simple anatomy and few taxonomically informative characters, and this has resulted in numerous taxonomic reassignments and synonymizations. Recent studies using a combination of morphological and molecular traits have helped to improve the taxonomy of Stilbonematinae but also raised questions on the validity of several genera. Here we describe a new circumtropically distributed genus Paralaxus (Stilbonematinae) with three species: Paralaxus cocos sp. nov., P. bermudensis sp. nov. and P. columbae sp. nov.. We used single worm metagenomes to generate host 18S rRNA and cytochrome oxidase I (COI) as well as symbiont 16S rRNA gene sequences. Intriguingly, COI alignments and primer matching analyses suggest that the COI is not suitxable for PCR-based barcoding approaches in Stilbonematinae as the genera have a highly diverse base composition and no conserved primer sites. The phylogenetic analyses of all three gene sets however confirm the morphological assignments and support the erection of the new genus Paralaxus as well as corroborate the status of the other stilbonematine genera. Paralaxus most closely resembles the stilbonematine genus Laxus in overlapping sets of diagnostic features but can be distinguished from Laxus by the morphology of the genus-specific symbiont coat. Our re-analyses of key parameters of the symbiont coat morphology as character for all Stilbonematinae genera show that with amended descriptions, including the coat, highly reliable genus assignments can be obtained.

2010 ◽  
Vol 60 (4) ◽  
pp. 828-833 ◽  
Author(s):  
Fergus G. Priest ◽  
Margaret Barker

Phylogenetic analyses of type and reference strains of Obesumbacterium proteus biogroups 1 and 2 plus a novel isolate of biogroup 2 were carried out based on 16S rRNA gene sequences and partial sequences of four protein-coding genes (fusA, leuS, pyrG and rpoB). Both approaches revealed that O. proteus biogroup 1 strains were closely related to Hafnia alvei. Biogroup 2 strains, however, formed a distinct monophyletic clade of generic status that included Escherichia blattae. Phenotypic tests were consistent with the molecular classification and provided diagnostic features. It is proposed that biogroup 2 strains be placed in a new genus, Shimwellia gen. nov., as Shimwellia pseudoproteus sp. nov., with strain 521T (=DSM 3038T=LMG 24835T=NCIMB 14534T) as the type strain, and that Escherichia blattae be transferred to the genus Shimwellia as Shimwellia blattae comb. nov., with strain ATCC 29907T (=DSM 4481T) as the type strain.


2013 ◽  
Vol 63 (Pt_9) ◽  
pp. 3336-3341 ◽  
Author(s):  
Erick Ruiz-Romero ◽  
María de los Angeles Coutiño-Coutiño ◽  
César Valenzuela-Encinas ◽  
María Patricia López-Ramírez ◽  
Rodolfo Marsch ◽  
...  

A novel Gram-positive, rod-shaped, spore-forming bacterium, designated 13CCT was isolated from soil of the former lake Texcoco. The strain was aerobic, catalase-positive and oxidase-negative. It grew at salinities of 0–26 % (w/v) NaCl with an optimum at 9–16 % (w/v) NaCl. The cells contain peptidoglycan type A1γ, A1γ′ with glycine instead of l-alanine and three variations of peptidoglycan type A4γ. The only quinone detected was MK-7. The major fatty acid was anteiso-C15 : 0. The polar lipids fraction consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and three different phospholipids. The DNA G+C content was 37.5 mol%. Maximum-likelihood phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 13CCT was closely related to members of the genus Bacillus and shared 92.35 % similarity with Bacillus agaradhaerens , 92.28 % with Bacillus neizhouensis and 92.21 % with Bacillus locisalis . It is proposed based on the phenotypic, genotypic and phylogenetic analyses that the novel isolate should be classified as a representative of a new genus and novel species, for which the name Texcoconibacillus texcoconensis gen. nov., sp. nov. is proposed. The type strain of Texcoconibacillus texcoconensis is 13CCT ( = JCM 17654T = DSM 24696T).


2011 ◽  
Vol 61 (7) ◽  
pp. 1515-1520 ◽  
Author(s):  
Jaewoo Yoon ◽  
Satoru Matsuda ◽  
Kyoko Adachi ◽  
Hiroaki Kasai ◽  
Akira Yokota

A Gram-negative-staining, obligately aerobic, non-motile, rod-shaped and chemoheterotrophic bacterium, designated strain MN1-1006T, was isolated from an ascidian (sea squirt) sample, and was studied using a polyphasic taxonomic approach. Phylogenetic analyses based on 16S rRNA gene sequences indicated that the new isolate shared approximately 93–99% sequence similarity with recognized species of the genus Rubritalea within the phylum ‘Verrucomicrobia’. DNA–DNA hybridization values between strain MN1-1006T and Rubritalea squalenifaciens HOact23T and Rubritalea sabuli YM29-052T were 57% and 14.5%, respectively. Strain MN1-1006T produced carotenoid compounds that rendered the cell biomass a reddish pink colour. The strain also contained squalene. The cell-wall peptidoglycan of the novel strain contained muramic acid and meso-diaminopimelic acid. The DNA G+C content of strain MN1-1006T was 51.4 mol%. The major cellular fatty acids were iso-C14:0, iso-C16:0 and anteiso-C15:0. The major isoprenoid quinone was MK-9. On the basis of these data, it was concluded that strain MN1-1006T represents a novel species of the genus Rubritalea, for which the name Rubritalea halochordaticola sp. nov. is proposed. The type strain is MN1-1006T ( = KCTC 23186T = NBRC 107102T).


2013 ◽  
Vol 63 (Pt_3) ◽  
pp. 934-938 ◽  
Author(s):  
Wen-Ming Chen ◽  
Rey-Chang Chang ◽  
Chih-Yu Cheng ◽  
Yu-Wen Shiau ◽  
Shih-Yi Sheu

A novel bacterium, designated strain JchiT, was isolated from soil in Taiwan and characterized using a polyphasic approach. Cells of strain JchiT were aerobic, Gram-stain-negative, motile and rod-shaped. They contained poly-β-hydroxybutyrate granules and formed dark-yellow colonies. Growth occurred at 20–37 °C (optimum between 25 and 30 °C), at pH 6.0–8.0 (optimum between pH 7.0 and pH 8.0) and with 0–2 % NaCl (optimum between 0 and 1 %). Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain JchiT belonged to the genus Jeongeupia and that its closest neighbour was Jeongeupia naejangsanensis BIO-TAS4-2T (98.0 % sequence similarity). The major fatty acids (>10 %) of strain JchiT were summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and C18 : 1ω7c. The major cellular hydroxy fatty acid was C12 : 0 3-OH. The isoprenoid quinone was Q-8 and the genomic DNA G+C content was 66.1 mol%. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylserine and two unidentified phospholipids. The DNA–DNA relatedness value between strain JchiT and J. naejangsanensis BIO-TAS4-2T was about 41.0 %. On the basis of the genotypic and phenotypic data, strain JchiT represents a novel species in the genus Jeongeupia , for which the name Jeongeupia chitinilytica sp. nov. is proposed. The type strain is JchiT ( = BCRC 80367T  = KCTC 23701T).


2015 ◽  
Vol 65 (Pt_7) ◽  
pp. 2078-2084 ◽  
Author(s):  
Bo Liu ◽  
Guo-Hong Liu ◽  
Cetin Sengonca ◽  
Peter Schumann ◽  
Ming-Kuang Wang ◽  
...  

A Gram-stain-positive, rod-shaped, endospore-forming, aerobic bacterium (FJAT-14571T) was isolated from a soil sample in Taiwan. Strain FJAT-14571T grew at 20–40 °C (optimum 35 °C), pH 6–10 (optimum pH 8) and 0–2 % (w/v) NaCl (optimum 0 %). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain FJAT-14571T was a member of the genus Bacillus and was most closely related to Bacillus oceanisediminis DSM 24771T (96.2 %). DNA–DNA relatedness between strain FJAT-14571T and B. oceanisediminis DSM 24771T was low (32.0 % ± 0.88 %). The diagnostic diamino acid of the peptidoglycan of strain FJAT-14571T was meso-diaminopimelic acid and the predominant menaquinone was MK-7 (96.6 %). The major cellular fatty acids were iso-C15 : 0 (46.4 %), anteiso-C15 : 0 (7.6 %), iso-C17 : 0 (8.2 %) and iso-C16 : 0 (10.0 %) and the DNA G+C content was 40.8 mol%. Phenotypic, chemotaxonomic and genotypic properties clearly indicated that strain FJAT-14571T represents a novel species within the genus Bacillus, for which the name Bacillus taiwanensis sp. nov. is proposed. The type strain is FJAT-14571T ( = DSM 27845T = CGMCC1.1 2698T).


2015 ◽  
Vol 65 (Pt_12) ◽  
pp. 4410-4416 ◽  
Author(s):  
Soon Dong Lee

A novel actinobacterium, designated strain C4-31T, was isolated from soil collected from a cave. Cells were aerobic, Gram-reaction-positive, oxidase-negative, catalase-positive and non-motile cocci. Comparison of 16S rRNA gene sequences showed that the organism occupied a distinct phylogenetic position within the suborder Frankineae, with sequence similarity values of less than 93.2 % to members of this suborder. The diagnostic diamino acid in the cell-wall peptidoglycan was meso-diaminopimelic acid. The major menaquinone was MK-9(H4). The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside, an unknown aminophospholipid and an unknown phospholipid. The major fatty acids were iso-C16 : 0, C17 : 1ω6c and C16 : 0. The G+C content of the DNA was 62.8 mol%. On the basis of morphological and chemotaxonomic data as well as phylogenetic evidence, strain C4-31T ( = KCTC 39556T = DSM 100065T) is considered to represent the type strain of a novel species of a new genus in the suborder Frankineae, for which the name Antricoccus suffuscus gen. nov., sp. nov. is proposed.


2012 ◽  
Vol 62 (2) ◽  
pp. 397-402 ◽  
Author(s):  
Rosa Margesin ◽  
Peter Schumann ◽  
De-Chao Zhang ◽  
Mersiha Redzic ◽  
Yu-Guang Zhou ◽  
...  

A Gram-stain-positive, aerobic, non-motile, psychrophilic bacterium, designated strain Cr6-08T, was isolated from alpine glacier cryoconite. Growth of strain Cr6-08T occurred at 1–25 °C. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain Cr6-08T is most closely related to members of the genus Arthrobacter. Strain Cr6-08T possessed chemotaxonomic properties consistent with those of the genus Arthrobacter, such as peptidoglycan type A3α (l-Lys–l-Ala4), MK-9(H2) as major menaquinone and anteiso- and iso-branched compounds (anteiso-C15 : 0 and iso-C15 : 0) as major cellular fatty acids. The polar lipid profile contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, one unknown glycolipid and three unknown polar lipids. The genomic DNA G+C content of strain Cr6-08T was 57.3 mol%. On the basis of phenotypic and chemotaxonomic characteristics, phylogenetic analysis and DNA–DNA relatedness data, strain Cr6-08T is considered to represent a novel species of the genus Arthrobacter, for which the name Arthrobacter cryoconiti sp. nov. is proposed. The type strain is Cr6-08T ( = DSM 23324T  = LMG 26052T  = CGMCC 1.10698T).


2010 ◽  
Vol 60 (2) ◽  
pp. 460-468 ◽  
Author(s):  
Miao Miao ◽  
Yangang Wang ◽  
Weibo Song ◽  
John C. Clamp ◽  
Khaled A. S. Al-Rasheid

Recently, an undescribed marine ciliate was isolated from China. Investigation of its morphology and infraciliature revealed it as an undescribed species representing a new genus, Eurystomatella n. gen., the type of the new family Eurystomatellidae n. fam. The new family is defined by close-set, apically positioned oral membranelles and a dominant buccal field that is surrounded by an almost completely circular paroral membrane. The new genus is defined by having a small oral membranelle 1 (M1), bipartite M2 and well-developed M3, a body surface faintly sculptured with a silverline system in a quadrangular, reticulate pattern and a cytostome located at the anterior third of a large buccal field. The type species of the new genus, Eurystomatella sinica n. sp., is a morphologically unique form that is defined mainly by the combination of a conspicuously flattened body, several caudal cilia, extremely long cilia associated with the buccal apparatus and a contractile vacuole located subcaudally. According to phylogenetic analyses of small-subunit (SSU) rRNA gene sequences, Eurystomatella clusters with the genus Cyclidium, as a sister group to the family Pleuronematidae. The great divergence in both buccal and somatic ciliature between Eurystomatella and all other known scuticociliates supports the establishment of a new family for Eurystomatella.


2010 ◽  
Vol 60 (12) ◽  
pp. 2908-2912 ◽  
Author(s):  
Young-Ok Kim ◽  
Hee Jeong Kong ◽  
Sooyeon Park ◽  
So-Jung Kang ◽  
Kyung-Kil Kim ◽  
...  

A Gram-stain-negative, non-motile, non-spore-forming and short rod- or rod-shaped bacterial strain, designated 22-5T, was isolated from a bluespotted cornetfish, Fistularia commersonii, and subjected to taxonomic study. Strain 22-5T grew optimally at 30 °C and in the presence of 2–5 % (w/v) NaCl. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain 22-5T belonged to the genus Paracoccus and joined the cluster comprising Paracoccus homiensis DD-R11T and Paracoccus zeaxanthinifaciens ATCC 21588T, with which strain 22-5T exhibited 97.4 and 96.9 % 16S rRNA gene sequence similarity, respectively. Strain 22-5T exhibited 94.0–96.6 % 16S rRNA gene sequence similarity with the other type strains of species of the genus Paracoccus. Strain 22-5T contained Q-10 as the predominant menaquinone and C18 : 1 ω7c as the predominant fatty acid. In this study, P. zeaxanthinifaciens KCTC 22688T also contained Q-10 as the predominant isoprenoid quinone. The DNA G+C content of strain 22-5T was 63.6 mol%. Strain 22-5T exhibited 44 and 32 % DNA–DNA relatedness to P. homiensis KACC 11518T and P. zeaxanthinifaciens KCTC 22688T, respectively. On the basis of phenotypic, phylogenetic and genetic data, strain 22-5T is considered to represent a novel species of the genus Paracoccus, for which the name Paracoccus fistulariae sp. nov. is proposed. The type strain is 22-5T (=KCTC 22803T =CCUG 58401T).


2013 ◽  
Vol 63 (Pt_5) ◽  
pp. 1906-1911 ◽  
Author(s):  
Shih-Yi Sheu ◽  
Yu-Wen Shiau ◽  
Yan-Ting Wei ◽  
Wen-Ming Chen

To investigate the biodiversity of bacteria in the spring water of the Chengcing Lake Park in Taiwan, a Gram-stain-negative, rod-shaped, non-motile, non-spore-forming and aerobic bacterial strain, designated strain Chen16-4T, was isolated and characterized in a taxonomic study using a polyphasic approach. Phylogenetic analyses based on 16S rRNA gene sequences showed that the closest relatives of strain Chen16-4T were Sphingobium amiense YTT, Sphingobium yanoikuyae GIFU 9882T and Sphingobium scionense WP01T, with sequence similarities of 97.6, 97.1 and 97.0 %, respectively. A phylogenetic tree obtained with 16S rRNA gene sequences indicated that strain Chen16-4T and these three closest relatives formed an independent phylogenetic clade within the genus Sphingobium . The polar lipid pattern, the presence of spermidine and ubiquinone Q-10, the predominance of C18 : 1ω7c in the cellular fatty acid profile and the DNA G+C content also supported affiliation of the isolate to the genus Sphingobium . The DNA–DNA relatedness of strain Chen16-4T with respect to recognized species of the genus Sphingobium was less than 70 %. On the basis of the genotypic, chemotaxonomic and phenotypic data, strain Chen16-4T represents a novel species in the genus Sphingobium , for which the name Sphingobium fontiphilum sp. nov. is proposed. The type strain is Chen16-4T ( = BCRC 80308T = LMG 26342T = KCTC 23559T).


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