scholarly journals Phylogenetic and morphological evaluation of the genera Anabaena, Aphanizomenon, Trichormus and Nostoc (Nostocales, Cyanobacteria)

Author(s):  
Pirjo Rajaniemi ◽  
Pavel Hrouzek ◽  
Klára Kaštovská ◽  
Raphaël Willame ◽  
Anne Rantala ◽  
...  

The heterocytous cyanobacteria form a monophyletic group according to 16S rRNA gene sequence data. Within this group, phylogenetic and morphological studies have shown that genera such as Anabaena and Aphanizomenon are intermixed. Moreover, the phylogeny of the genus Trichormus, which was recently separated from Anabaena, has not been investigated. The aim was to study the taxonomy of the genera Anabaena, Aphanizomenon, Nostoc and Trichormus belonging to the family Nostocaceae (subsection IV.I) by morphological and phylogenetic analyses of 16S rRNA gene, rpoB and rbcLX sequences. New strains were isolated to avoid identification problems caused by morphological changes of strains during cultivation. Morphological and phylogenetic data showed that benthic and planktic Anabaena strains were intermixed. In addition, the present study confirmed that Anabaena and Aphanizomenon strains were not monophyletic, as previously demonstrated. The evolutionary distances between the strains indicated that the planktic Anabaena and Aphanizomenon strains as well as five benthic Anabaena strains in cluster 1 could be assigned to a single genus. On the basis of the 16S rRNA, rpoB and rbcLX gene sequences, the Anabaena/Aphanizomenon strains (cluster 1) were divided into nine supported subclusters which could also be separated morphologically, and which therefore might represent different species. Trichormus strains were morphologically and phylogenetically heterogeneous and did not form a monophyletic cluster. These Trichormus strains, which were representatives of three distinct species, might actually belong to three genera according to the evolutionary distances. Nostoc strains were also heterogeneous and seemed to form a monophyletic cluster, which may contain more than one genus. It was found that certain morphological features were stable and could be used to separate different phylogenetic clusters. For example, the width and the length of akinetes were useful features for classification of the Anabaena/Aphanizomenon strains in cluster 1. This morphological and phylogenetic study with fresh isolates showed that the current classification of these anabaenoid genera needs to be revised.

2004 ◽  
Vol 54 (6) ◽  
pp. 2223-2230 ◽  
Author(s):  
Linxian Ding ◽  
Akira Yokota

Two strains of curved bacteria, 7-1T and 7-2T, isolated from well water, were phylogenetically examined to determine their taxonomic position. Strain 7-1T is a Gram-negative, slightly curved rod. Analysis of the 16S rRNA gene sequence showed that strain 7-1T formed a cluster with [Aquaspirillum] delicatum and [Pseudomonas] lanceolata. It has some similar characteristics to [A.] delicatum and [P.] lanceolata, but has sufficient distance to separate it from other genera. DNA–DNA hybridization analysis, as well as chemotaxonomic and morphological studies, demonstrated that strain 7-1T, [A.] delicatum and [P.] lanceolata belong to a new genus, Curvibacter gen. nov. Strain 7-1T (=IAM 15033T=ATCC BAA-807T) is classified as the type strain of Curvibacter gracilis gen. nov., sp. nov., and [A.] delicatum and [P.] lanceolata are classified as Curvibacter delicatus comb. nov. and Curvibacter lanceolatus comb. nov., respectively. Strain 7-2T is a Gram-negative spirillum. Phylogenetic study based on the 16S rRNA gene sequences showed that it formed a cluster with the members of the genus Herbaspirillum, [Pseudomonas] huttiensis and [Aquaspirillum] autotrophicum. The classification is therefore proposed of strain 7-2T (=IAM 15032T=ATCC BAA-806T) as the type strain of Herbaspirillum putei sp. nov., and [P.] huttiensis and [A.] autotrophicum are transferred to the genus Herbaspirillum as Herbaspirillum huttiense comb. nov. and Herbaspirillum autotrophicum comb. nov., respectively.


2013 ◽  
Vol 80 (4) ◽  
pp. 1403-1410 ◽  
Author(s):  
Clare A. Anstead ◽  
Neil B. Chilton

ABSTRACTThe genomic DNA from four species of ixodid ticks in western Canada was tested for the presence ofRickettsiellaby PCR analyses targeting the 16S rRNA gene. Eighty-eight percent of theIxodes angustus(n= 270), 43% of theI. sculptus(n= 61), and 4% of theI. kingi(n= 93) individuals examined were PCR positive forRickettsiella, whereas there was no evidence for the presence ofRickettsiellainDermacentor andersoni(n= 45). Three different single-strand conformation polymorphism profiles of the 16S rRNA gene were detected among amplicons derived fromRickettsiella-positive ticks, each corresponding to a different sequence type. Furthermore, each sequence type was associated with a different tick species. Phylogenetic analyses of sequence data of the 16S rRNA gene and three other genes (rpsA,gidA, andsucB) revealed that all three sequence types were placed in a clade that contained species and pathotypes of the genusRickettsiella. The bacterium inI. kingirepresented the sister taxon to theRickettsiellainI. sculptus, and both formed a clade withRickettsiellagryllifrom crickets (Gryllus bimaculatus) and “R. ixodidis” fromI. woodi. In contrast, theRickettsiellainI. angustuswas not a member of this clade but was placed external to the clade comprising the pathotypes ofR. popilliae. The results indicate the existence of at least two new species ofRickettsiella: one inI. angustusand another inI. kingiandI. sculptus. However, theRickettsiellastrains inI. kingiandI. sculptusmay also represent different species because each had unique sequences for all four genes.


2000 ◽  
Vol 66 (10) ◽  
pp. 4222-4229 ◽  
Author(s):  
Scott R. Miller ◽  
Richard W. Castenholz

ABSTRACT The extension of ecological tolerance limits may be an important mechanism by which microorganisms adapt to novel environments, but it may come at the evolutionary cost of reduced performance under ancestral conditions. We combined a comparative physiological approach with phylogenetic analyses to study the evolution of thermotolerance in hot spring cyanobacteria of the genus Synechococcus. Among the 20 laboratory clones of Synechococcus isolated from collections made along an Oregon hot spring thermal gradient, four different 16S rRNA gene sequences were identified. Phylogenies constructed by using the sequence data indicated that the clones were polyphyletic but that three of the four sequence groups formed a clade. Differences in thermotolerance were observed for clones with different 16S rRNA gene sequences, and comparison of these physiological differences within a phylogenetic framework provided evidence that more thermotolerant lineages of Synechococcus evolved from less thermotolerant ancestors. The extension of the thermal limit in these bacteria was correlated with a reduction in the breadth of the temperature range for growth, which provides evidence that enhanced thermotolerance has come at the evolutionary cost of increased thermal specialization. This study illustrates the utility of using phylogenetic comparative methods to investigate how evolutionary processes have shaped historical patterns of ecological diversification in microorganisms.


2007 ◽  
Vol 57 (11) ◽  
pp. 2462-2466 ◽  
Author(s):  
Jung-Hoon Yoon ◽  
So-Jung Kang ◽  
Tae-Kwang Oh

A Gram-negative, non-motile, rod-shaped bacterial strain, DS-57T, was isolated from soil from Dokdo, Korea, and its taxonomic position was investigated using a polyphasic approach. It grew optimally at 25 °C and in trypticase soy broth without NaCl and trypticase soy broth with 0.5 % NaCl. Strain DS-57T contained MK-7 as the predominant menaquinone and iso-C15 : 0, C16 : 1 ω7c and/or iso-C15 : 0 2-OH and iso-C17 : 0 3-OH as the major fatty acids. The DNA G+C content was 39.7 mol%. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain DS-57T was most closely related to the genus Pedobacter of the family Sphingobacteriaceae, clustering coherently with Pedobacter suwonensis, Pedobacter roseus and Pedobacter sandarakinus. Strain DS-57T exhibited 16S rRNA gene sequence similarity values of 99.2, 97.9 and 97.2 % with respect to the type strains of P. suwonensis, P. roseus and P. sandarakinus, respectively, and values less than 95.6 % with respect to the type strains of other Pedobacter species. Strain DS-57T exhibited levels of DNA–DNA relatedness of 45, 17 and 15 % with respect to the type strains of P. suwonensis, P. roseus and P. sandarakinus, respectively. Differential phenotypic properties, together with the phylogenetic distinctiveness and the DNA–DNA relatedness data, were sufficient to allow the classification of strain DS-57T as a species that is separate from recognized Pedobacter species. On the basis of phenotypic properties and phylogenetic distinctiveness, therefore, strain DS-57T represents a novel species of the genus Pedobacter, for which the name Pedobacter terrae sp. nov. is proposed. The type strain is DS-57T (=KCTC 12762T=DSM 17933T).


2011 ◽  
Vol 61 (6) ◽  
pp. 1259-1264 ◽  
Author(s):  
D. P. Labeda ◽  
M. Goodfellow ◽  
J. Chun ◽  
X.-Y. Zhi ◽  
W.-J. Li

The taxonomic status of the families Actinosynnemataceae and Pseudonocardiaceae was assessed based on 16S rRNA gene sequence data available for the 151 taxa with validly published names, as well as chemotaxonomic and morphological properties available from the literature. 16S rRNA gene sequences for the type strains of all taxa within the suborder Pseudonocardineae were subjected to phylogenetic analyses using different algorithms in arb and phylip. The description of many new genera and species within the suborder Pseudonocardineae since the family Actinosynnemataceae was proposed in 2000 has resulted in a markedly different distribution of chemotaxonomic markers within the suborder from that observed at that time. For instance, it is noted that species of the genera Actinokineospora and Allokutzneria contain arabinose in whole-cell hydrolysates, which is not observed in the other genera within the Actinosynnemataceae, and that there are many genera within the family Pseudonocardiaceae as currently described that do not contain arabinose. Phylogenetic analyses of 16S rRNA gene sequences for all taxa within the suborder do not provide any statistical support for the family Actinosynnemataceae, nor are signature nucleotides found that support its continued differentiation from the family Pseudonocardiaceae. The description of the family Pseudonocardiaceae is therefore emended to include the genera previously classified within the family Actinosynnemataceae and the description of the suborder Pseudonocardineae is also emended to reflect this reclassification.


2005 ◽  
Vol 55 (3) ◽  
pp. 1167-1170 ◽  
Author(s):  
Jung-Hoon Yoon ◽  
Kook Hee Kang ◽  
Soo-Hwan Yeo ◽  
Tae-Kwang Oh

A Gram-negative, non-spore-forming, yellow-pigmented, slightly halophilic bacterial strain, SW-109T, was isolated from a tidal flat of the Yellow Sea in Korea, and subjected to a polyphasic taxonomic study. This isolate did not produce bacteriochlorophyll a and contained ubiquinone-10 as the predominant respiratory lipoquinone and C18 : 1 ω7c as the major fatty acid. The DNA G+C content was 60·3 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain SW-109T is phylogenetically affiliated to the genus Erythrobacter of the family Sphingomonadaceae. Strain SW-109T exhibited levels of 16S rRNA gene sequence similarity to the type strains of Erythrobacter species of 94·0–96·3 %, making it possible to categorize strain SW-109T as a species that is separate from previously recognized Erythrobacter species. On the basis of its phenotypic properties and phylogenetic distinctiveness, SW-109T (=KCTC 12311T=JCM 12599T) was classified as the type strain of a novel Erythrobacter species, for which the name Erythrobacter luteolus sp. nov. is proposed.


2012 ◽  
Vol 62 (Pt_9) ◽  
pp. 2163-2168 ◽  
Author(s):  
Yong-Taek Jung ◽  
Ji-Hoon Kim ◽  
So-Jung Kang ◽  
Tae-Kwang Oh ◽  
Jung-Hoon Yoon

A Gram-staining-negative, non-flagellated, non-gliding and pleomorphic bacterial strain, designated DPG-25T, was isolated from seawater in a seaweed farm in the South Sea in Korea and its taxonomic position was investigated by using a polyphasic approach. Strain DPG-25T grew optimally at 25 °C, at pH 7.0–7.5 and in the presence of 2 % (w/v) NaCl. Flexirubin-type pigments were not produced. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain DPG-25T formed a cluster with the type strains of Actibacter sediminis , Aestuariicola saemankumensis and Lutimonas vermicola . Strain DPG-25T exhibited 16S rRNA gene sequence similarity values of 95.3, 93.1 and 93.6 % to the type strains of Actibacter sediminis , Aestuariicola saemankumensis and L. vermicola , respectively. Strain DPG-25T contained MK-6 as the predominant menaquinone and iso-C15 : 0 and iso-C17 : 0 3-OH as the major fatty acids. The major polar lipids detected in strain DPG-25T were phosphatidylethanolamine and one unidentified lipid. The DNA G+C content was 39.9 mol%. Differential phenotypic properties and the phylogenetic distinctiveness of strain DPG-25T demonstrated that this strain is distinguishable from Actibacter sediminis , Aestuariicola saemankumensis and L. vermicola . On the basis of the data presented here, strain DPG-25T represents a novel species in a novel genus of the family Flavobacteriaceae , for which the name Namhaeicola litoreus gen. nov., sp. nov. is proposed. The type strain of Namhaeicola litoreus is DPG-25T ( = KCTC 23702T  = CCUG 61485T).


2015 ◽  
Vol 65 (Pt_4) ◽  
pp. 1207-1212 ◽  
Author(s):  
Hong-Fei Wang ◽  
Yong-Guang Zhang ◽  
Ji-Yue Chen ◽  
Jian-Wei Guo ◽  
Li Li ◽  
...  

A novel endophytic actinobacterium, designated EGI 6500707T, was isolated from the surface-sterilized root of a halophyte Anabasis elatior (C. A. Mey.) Schischk collected from Urumqi, Xinjiang province, north-west China, and characterized using a polyphasic approach. Cells were Gram-stain-positive, non-motile, short rods and produced white colonies. Growth occurred at 10–45 °C (optimum 25–30 °C), at pH 5–10 (optimum pH 8) and in presence of 0–4 % (w/v) NaCl (optimum 0–3 %). The predominant menaquinone was MK-9. The diagnostic phospholipids were diphosphatidylglycerol and phosphatidylglycerol. The major fatty acids were anteiso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 0. The DNA G+C content of strain EGI 6500707T was 69.1 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain EGI 6500707T should be placed in the genus Frigoribacterium (family Microbacteriaceae , phylum Actinobacteria ), and that the novel strain exhibited the highest 16S rRNA gene sequence similarity to Frigoribacterium faeni JCM 11265T (99.1 %) and Frigoribacterium mesophilum MSL-08T (96.5 %). DNA–DNA relatedness between strain EGI 6500707T and F. faeni JCM 11265T was 47.2 %. On the basis of phenotypic and chemotaxonomic characteristics, phylogenetic analysis and DNA–DNA relatedness data, strain EGI 6500707T represents a novel species of the genus Frigoribacterium , for which the name Frigoribacterium endophyticum sp. nov. is proposed. The type strain is EGI 6500707T ( = JCM 30093T = KCTC 29493T).


Algologia ◽  
2021 ◽  
Vol 31 (1) ◽  
pp. 93-113
Author(s):  
A.R. Nur Fadzliana ◽  
◽  
W.O. Wan Maznah ◽  
S.A.M. Nor ◽  
Choon Pin Foong ◽  
...  

Cyanobacteria are the most widespread group of photosynthetic prokaryotes. They are primary producers in a wide variety of habitats and are able to thrive in harsh environments, including polluted waters; therefore, this study was conducted to explore the cyanobacterial populations inhabiting river tributaries with different levels of pollution. Sediment samples (epipelon) were collected from selected tributaries of the Pinang River basin. Air Terjun (T1) and Air Itam rivers (T2) represent the upper streams of Pinang River basin, while Dondang (T3) and Jelutong rivers (T4) are located at in the middle of the river basin. The Pinang River (T5) is located near the estuary and is subjected to saline water intrusion during high tides. Cyanobacterial community was determined by identifying the taxa via 16S rRNA gene amplicon sequence data. 16S rRNA gene amplicons generated from collected samples were sequenced using illumina Miseq, with the targeted V3 and V4 regions yielding approximately 1 mln reads per sample. Synechococcus, Phormidium, Arthronema and Leptolyngbya were found in all samples. Shannon-Weiner diversity index was highest (H’ = 1.867) at the clean upstream station (T1), while the moderately polluted stream (T3) recorded the lowest diversity (H’ = 0.399), and relatively polluted stations (T4 and T5) recorded fairly high values of H’. This study provides insights into the cyanobacterial community structure in Pinang River basin via cultivation-independent techniques using 16S rRNA gene amplicon sequence. Occurrence of some morphospecies at specific locations showed that the cyanobacterial communities are quite distinct and have specific ecological demands. Some species which were ubiquitous might be able to tolerate varied environmental conditions.


2010 ◽  
Vol 60 (12) ◽  
pp. 2719-2723 ◽  
Author(s):  
Dong-Heon Lee ◽  
Sung-Ran Moon ◽  
Young-Hyun Park ◽  
Jung-Ho Kim ◽  
Hoon Kim ◽  
...  

A novel Gram-negative, aerobic, motile, short rod-shaped bacterium, designated MS-3T, was isolated from a crude oil-contaminated seashore in Taean, Korea. Strain MS-3T grew at 4–30 °C, at pH 6.0–9.5 and with 0–5 % NaCl and was oxidase- and catalase-positive. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain MS-3T was most similar to Pseudomonas marincola KMM 3042T (97.9 % 16S rRNA gene sequence similarity), P. cuatrocienegasensis 1NT (97.8 %), P. borbori R-20821T (97.3 %) and P. lundensis ATCC 49968T (97.1 %). Relatively low levels of DNA–DNA relatedness were found between strain MS-3T and P. cuatrocienegasensis LMG 24676T (57.2 %), P. borbori LMG 23199T (39.7 %), P. marincola KMM 3042T (32.2 %) and P. lundensis KACC 10832T (32.1 %), which support the classification of strain MS-3T within a novel species of the genus Pseudomonas. The G+C content of the genomic DNA of strain MS-3T was 57.6 mol% and the major isoprenoid quinone was Q-9. Strain MS-3T contained summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1 ω7c; 38.0 %), C16 : 0 (24.4 %), C18 : 1 ω7c (12.8 %), C12 : 0 (9.6 %) and C10 : 0 3-OH (4.9 %) as the major cellular fatty acids. On the basis of the phenotypic, genotypic and phylogenetic data, strain MS-3T represents a novel species of the genus Pseudomonas, for which the name Pseudomonas taeanensis sp. nov. is proposed. The type strain is MS-3T (=KCTC 22612T =KACC 14032T =JCM 16046T =NBRL 105641T).


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