scholarly journals Multigene-Based Analyses of the Phylogenetic Evolution of Oligotrich Ciliates, with Consideration of the Internal Transcribed Spacer 2 Secondary Structure of Three Systematically Ambiguous Genera

2013 ◽  
Vol 12 (3) ◽  
pp. 430-437 ◽  
Author(s):  
Jiamei Li ◽  
Weiwei Liu ◽  
Shan Gao ◽  
Alan Warren ◽  
Weibo Song

ABSTRACT Oligotrichs are ciliates of great abundance, but their molecular systematics are rarely studied. In this study, nine species representing three genera ( Strombidium , Novistrombidium , and Omegastrombidium ) of marine oligotrich ciliates were collected from coastal waters of China. The small subunit (SSU) rRNA gene of two species and the internal transcribed spacers and 5.8S region (ITS1-5.8S-ITS2) for all nine species were sequenced for the first time. Phylogenetic trees using both the SSU rRNA gene and ITS1-5.8S-ITS2 region sequences were generated. In addition, the secondary structures of ITS2 RNA transcripts of 11 taxa representing four genera ( Novistrombidium , Strombidium , Omegastrombidium , and Laboea ) were investigated. The phylogenetic analyses show that (i) the family Strombidiidae is polyphyletic, (ii) the genus Novistrombidium is probably paraphyletic, containing at least two subclades, which is consistent with recent cladistic analyses based on morphological data, and (iii) the tail-less genus Laboea is separate from other genera of Strombidiidae, clustering instead with the tontoniids. Comparisons of the secondary structure of ITS2 regions also show that Laboea is clearly different from other strombidiids. These findings cast doubt on the monophyly of the family Strombidiidae.

2011 ◽  
Vol 61 (4) ◽  
pp. 1001-1010 ◽  
Author(s):  
Ping Sun ◽  
John C. Clamp ◽  
Dapeng Xu ◽  
Yasushi Kusuoka ◽  
Manabu Hori

Little is known about the phylogeny of the family Vorticellidae at the generic level because few comprehensive analyses of molecular phylogenetic relationships between members of this group have, so far, been done. As a result, the phylogenetic positions of some genera that were based originally on morphological analyses remain controversial. In the present study, we performed phylogenetic analyses of vorticellids based on the sequence of the small-subunit (SSU) rRNA gene, including one species of the genus Apocarchesium, for which no sequence has previously been reported. Phylogenetic trees were reconstructed with SSU rRNA gene sequences by using four different methods (Bayesian analysis, maximum-likelihood, neighbour-joining and maximum-parsimony) and had a consistent branching pattern. Members of the genera Vorticella (except V. microstoma) and Carchesium formed a clearly defined, well supported clade that was divergent from the clade comprising members of the genera Pseudovorticella and Epicarchesium, suggesting that the differences in the silverline system (transverse vs reticulate) among vorticellids may be the result of genuine evolutionary divergence. Members of the newly established genus Apocarchesium clustered within the family Vorticellidae basal to the clade containing members of the genera Pseudovorticella and Epicarchesium and were distinct from members of the genus Carchesium, supporting the validity of Apocarchesium as a novel genus. Additional phylogenetic analyses of 21 strains representing seven genera from the families Vorticellidae and Zoothamniidae were performed with single datasets (ITS1–5.8S–ITS2, ITS2 alone) and combined datasets (SSU rRNA+ITS1–5.8S–ITS2, SSU rRNA+ITS2) to explore further the phylogenetic relationship between the three morphologically similar genera Carchesium, Epicarchesium and Apocarchesium, using characteristics not included in previous analyses. The phylogenetic trees reconstructed with combined datasets were more robust and therefore more reliable than those based on single datasets and supported the results of trees based on SSU rRNA sequences.


Author(s):  
Kyung June Yim ◽  
Dong-Hyun Jung ◽  
Seok Won Jang ◽  
Sanghwa Park

A cream-coloured, Gram-stain-negative, rod-shaped bacterium, designated strain KSC-6T, was isolated from soil sampled at the Gapcheon River watershed in Daejeon, Republic of Korea. The organism does not require NaCl for growth and grows at pH 6.0–8.0 (optimum, pH 7.0) and 10–37 °C (optimum, 25 °C). Phylogenetic trees based on the 16S rRNA gene sequences reveal that strain KSC-6T belongs to the family Chitinophagaceae within the order Chitinophagales and is most closely related to Panacibacter ginsenosidivorans Gsoil 1550T (95.9% similarity). The genomic DNA G+C content was 38.9 mol%. The major cellular fatty acids (>8 %) of strain KCS-6T were iso-C15:0, iso-C15 : 1 G and iso-C17 : 0 3-OH. The predominant respiratory quinone was menaquinone 7 and the predominant polar lipids were phosphatidylethanolamine, five unidentified aminolipids and two unidentified lipids. Based on genome analyses, low digital DNA–DNA hybridization, average nucleotide identity and average amino acid identity values with closely related genera, and differential chemotaxonomic and physiological properties, we suggest that strain KCS-6T represents a novel species in a new genus in the family Chitinophagaceae , for which the name Limnovirga soli gen. nov., sp. nov. (type strain KCS-6T=KCCM 43337T=NBRC 114336T) is proposed.


2008 ◽  
Vol 74 (12) ◽  
pp. 3710-3717 ◽  
Author(s):  
Jennifer J. Joyner ◽  
R. Wayne Litaker ◽  
Hans W. Paerl

ABSTRACT Dense blooms of the cyanobacterium Lyngbya wollei are increasingly responsible for declining water quality and habitat degradation in numerous springs, rivers, and reservoirs. This research represents the first molecular phylogenetic analysis of L. wollei in comparison with the traditional morphological characterization of this species. Specimens were collected from several springs in Florida and a reservoir in North Carolina. Segments of the small-subunit (SSU) rRNA and nifH genes were PCR amplified, cloned, and sequenced. The phylogenetic analysis of the SSU rRNA gene revealed sequences that fell into three distinct subclusters, each with >97% sequence similarity. These were designated operational taxonomic unit 1 (OTU1), OTU2, and OTU3. Similarly, the nifH sequences fell into three distinct subclusters named S1, S2, and S3. When either bulk samples or individual filaments were analyzed, we recovered OTU1 with S1, OTU2 with S2, and OTU3 with S3. The coherence between the three SSU rRNA gene and nifH subclusters was consistent with genetically distinct strains or species. Cells associated with subclusters OTU3 and S3 were significantly wider and longer than those associated with other subclusters. The combined molecular and morphological data indicate that the species commonly identified as L. wollei in the literature represents two or possibly more species. Springs containing OTU3 and S3 demonstrated lower ion concentrations than other collection sites. Geographical locations of Lyngbya subclusters did not correlate with residual dissolved inorganic nitrogen or phosphorus concentrations. This study emphasizes the need to complement traditional identification with molecular characterization to more definitively detect and characterize harmful cyanobacterial species or strains.


2012 ◽  
Vol 78 (11) ◽  
pp. 4051-4056 ◽  
Author(s):  
Lisa D. Tymensen ◽  
Tim A. McAllister

ABSTRACTThe diversity of protozoan-associated methanogens in cattle was investigated using five universal archaeal small-subunit (SSU) rRNA gene primer sets.Methanobrevibacterspp. and rumen cluster C (distantly related toThermoplasmaspp.) were predominant. Significant differences in species composition among libraries indicate that some primers used previously to characterize rumen methanogens exhibit biased amplification.


2020 ◽  
Vol 70 (5) ◽  
pp. 3468-3474 ◽  
Author(s):  
Fang-Ling Li ◽  
Xiao-Tong Wang ◽  
Jian-Jie Shan ◽  
Shuai Li ◽  
Ya-Xi Zhang ◽  
...  

A novel Gram-staining-negative, spiral-shaped bacterium, designated strain 64-1T, was isolated from oil reservoir water collected from Liaohe oilfield, north-eastern China. Growth occurred at 15–55 °C and pH 6.0–10.0. The sole respiratory quinone was Q-10. The predominant cellular fatty acids were summed feature 8 (C18 : 1  ω7c /C18 : 1  ω6c), C16 : 0 and C19 : 0 cyclo ω8c. The polar lipids consisted of phosphatidylethanolamine (PE), phosphatidylglycerol (PG), phosphatidylcholine (PC), an unidentified aminophospholipid (UAPL), an unidentified aminolipid (UAL) and two unidentified polar lipids (UPL). The genomic DNA G+C content of strain 64-1T was 64.5 mol%. Strain 64-1T shared the highest 16S rRNA gene sequence similarities with Phaeospirillum chandramohanii JA145T (92.0 %) and Telmatospirillum siberiense 26-4b1T (91.8 %). In the phylogenetic trees, the strain constituted a sub-cluster within the family Rhodospirillaceae . Based on the results of morphological, physiological, biochemical and phylogenetic analysis, strain 64-1T represents a new species of a novel genus within the family Rhodospirillaceae , for which the name Oleiliquidispirillum nitrogeniifigens gen. nov., sp. nov. is proposed. The type strain is 64-1T (=CGMCC 1.16798T=LMG 31399T).


Author(s):  
Ling-Fei Lu ◽  
Yang Yang ◽  
Li-Juan Chai ◽  
Zhen-Ming Lu ◽  
Li-Qiang Zhang ◽  
...  

A novel Gram-positive, non-motile, non-flagellated, strictly anaerobic, non-spore-forming and dumbbell-shaped, coccoid- or chain-shaped bacterium, designated strain LZLJ-3T, was isolated from a mud fermentation cellar which has been used for the production of Chinese strong-flavour liquor for over 100 years. Strain LZLJ-3T grew at 20–40 °C (optimum, 37 °C), at pH 6.0–8.0 (optimum, pH 8.0) and with NaCl concentrations up to 1 % (w/v; optimum, 0 %). Phylogenetic trees established based on 16S rRNA gene sequences showed that strain LZLJ-3T belonged to the genus Blautia of the family Lachnospiraceae, with the highest sequence similarity to Blautia stercoris GAM6-1T (91.7 %) and Blautia faecicola KGMB01111T (91.7 %). Comparative genome analysis showed that the orthologous average nucleotide identity (OrthoANI) and genome-to-genome distance (GGD) values between strain LZLJ-3T and B. stercoris GAM6-1T were respectively 69.1 and 22.9 %; the OrthoANI and GGD values between strain LZLJ-3T and B. faecicola KGMB01111T were respectively 70.86 and 36 % . The DNA G+C content of strain LZLJ-3T genome was 42.1 mol%. The predominant celluar fatty acids (>10 %) of strain LZLJ-3T were C16 : 0 FAME (27.9 %), C14 : 0 FAME (17.6 %) and C16 : 0 DMA (13.0 %). Arabinose, glucose and maltose could be utilized by strain LZLJ-3T as sole carbon sources for growth, with weak utilization of raffinose and l-fucose. API ZYM analysis gave positive reactions with α-galactosidase, β-galactosidase, α-glucosidase and β-glucosidase. The major end product of glucose fermentation was acetic acid. Based on the results of phenotypic, genotypic and phylogenetic analyses, strain LZLJ-3T is considered to represent a novel species of Blautia , for which the name Blautia liquoris sp. nov. is proposed. The type strain is LZLJ-3T (=KCTC 25163T=CGMCC 1.5299T=JCM 34225T).


2014 ◽  
Vol 64 (Pt_2) ◽  
pp. 533-539 ◽  
Author(s):  
Asif Hameed ◽  
Mariyam Shahina ◽  
Shih-Yao Lin ◽  
Wei-An Lai ◽  
You-Cheng Liu ◽  
...  

A Gram-staining-negative, orange-pigmented, strictly aerobic, carotenoid-producing, rod-shaped, non-flagellated, non-spore-forming bacterium, motile by gliding, designated strain CC-AMO-30DT, was isolated from surface seawater collected near Taichung harbour, Taiwan. Strain CC-AMO-30DT shared pairwise 16S rRNA gene sequence similarities of 94.8, 93.7 and 92.5 % with the type strains of the type species of the genera Joostella , Pustulibacterium and Galbibacter , respectively, and formed a distinct monophyletic lineage in phylogenetic trees. The major fatty acids (≥5 % of total) were iso-C15 : 1 G, iso-C15 : 0, iso-C17 : 0 3-OH, iso-C15 : 0 3-OH, iso-C16 : 0 and anteiso-C15 : 0. The polar lipid profile consisted of phosphatidylethanolamine, four unidentified lipids, two unidentified aminolipids and an unidentified phospholipid. The major polyamine was the triamine sym-homospermidine. The DNA G+C content was 47.1 mol% and the predominant respiratory quinone was menaquinone-6 (MK-6). Based on the phylogenetic distinctiveness and distinguishing phenotypic characteristics, strain CC-AMO-30DT represents a novel genus and species of the family Flavobacteriaceae , for which the name Robertkochia marina gen. nov., sp. nov. is proposed; the type strain of the type species Robertkochia marina is CC-AMO-30DT ( = JCM 18552T = BCRC 80469T). Emended descriptions of the genera Joostella and Galbibacter are also proposed.


Author(s):  
Mingchao Xu ◽  
Yan Dai ◽  
Yuyuan Huang ◽  
Jing Yang ◽  
Xin-He Lai ◽  
...  

Two pairs of aerobic, Gram-stain-positive, rod-shaped strains (HY164T/HY044, HY168T/HY211) were isolated from bat faecal samples. Strains HY164T and HY044 were motile with a polar flagellum, and had 16S rRNA gene similarity of 95.1–98.6 % to Haloactinobacterium album YIM 93306T and Haloactinobacterium glacieicola T3246-1T; strains HY168T and HY211 were most similar to Ruania albidiflava DSM 18029T (96.6 %). Phylogenetic trees based on 16S rRNA gene and whole genome sequences revealed affiliation of strains HY164T and HY168T to the family Ruaniaceae , representing novel lineages in the genera Haloactinobacterium and Ruania , respectively, which was also supported by the results for average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH). For all isolates, the principal cellular fatty acids were anteiso-C15 : 0 and iso-C14 : 0. HY164T and HY168T had MK-8(H4) as the predominant isoprenoid quinone, diphosphatidylglycerol, phosphatidylglycerol, several unidentified phospholipids and glycolipids as common polar lipids while the latter strain additionally contained one unidentified aminophospholipid and one unidentified phosphoglycolipid. Besides sharing alanine, glutamic acid and lysine with HY164T, HY168T additionally contained 2,4-diaminobutyric acid in the cell-wall peptidoglycan. The whole-cell sugars of HY164T were ribose and rhamnose, while HY168T only included the latter. The DNA G+C contents of HY164T and HY168T were 71.0 and 69.1 mol%, respectively. Combining the polyphasic taxonomic data, HY164T (=CGMCC 4.7606T=JCM 33464T) is classified as representing a novel species of the genus Haloactinobacterium with the proposed name Haloactinobacterium kanbiaonis sp. nov., and HY168T (=CGMCC 1.16970T=JCM 33465T) is proposed to represent a novel species of the genus Ruania with the name Ruania zhangjianzhongii sp. nov.


2013 ◽  
Vol 63 (Pt_12) ◽  
pp. 4669-4674 ◽  
Author(s):  
Véronique Guérin-Faublée ◽  
Jean-Pierre Flandrois ◽  
Catherine Pichat ◽  
Maria Laura Boschiroli ◽  
Brigitte Lamy

Three independent strains of a rapidly growing, non-chromogenic member of the genus Mycobacterium were isolated from lymph nodes of French cattle. Identification of the isolates was carried out using a polyphasic approach. The nearly complete SSU rRNA gene sequences (>1200 bp) of the strains MLB-A23, MLB-A30 and MLB-A84T were identical. A phylogenetic analysis of these unique SSU rRNA gene sequences showed that these strains were most closely related to Mycobacterium intermedium . Further phylogenetic analysis based on concatenated sequences (2854 bp) of four housekeeping genes (hsp65, rpoB, sodA and tuf), the transfer–messenger RNA (tmRNA) and SSU rRNA genes indicated that these three strains represented a distinct species that shares a common ancestor with M. intermedium . Phylogenetic and phenotypic data strongly indicate that the strains MLB-A23, MLB-A30 and MLB-A84T belong to a novel mycobacterial species for which the name Mycobacterium bourgelatii sp. nov. is proposed. The type strain is MLB-A84T ( = CIP 110557T = DSM 45746T).


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