FIG 4 - uploaded by Dale A. Casamatta
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(A and B) Arthronema gygaxiana UTCC393, showing involution cell (A) and asymmetric cell division (B). (C and D) Pseudanabaena tremula UTCC471, showing typical unconstricted trichomes without sheaths (C) as well as rare subtly constricted trichomes with sheaths (D). (E-H) Leptolyngbya angustata UTCC 473, showing false branching (E), hormogonia (F), tapered hormogonium (G), and multiple trichomes in a common sheath (H). (I) Leptolyngbya tenerrima. Scale bars, 10 mm.
Source publication
An approximately 1400-bp region of the 16S rRNA gene was sequenced for 10 polar or near-polar strains putatively placed in the Oscillatorialean genera Oscillatoria, Phormidium, and Lyngbya obtained from the University of Toronto Culture Collection to assess phylogenetic relationships. The strains were also examined for thylakoid structure and cell...
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Citations
... The 50 μL PCR reaction contained: 27 μL DNA containing supernatant, 0.5 μL of each primer (0.01 mM concentration), and 22 μL PCR Master Mix (Promega, Madison, WI, USA). PCR amplification proceeded as detailed in Casamatta et al. (2005), and products were frozen and sent to Eurofins Scientific (Louisville, Kentucky) for Sanger sequencing. ...
High‐sulfur, low‐oxygen environments formed by underwater sinkholes and springs create unique habitats populated by microbial mat communities. To explore the diversity and biogeography of these mats, samples were collected from three sites in Alpena, Michigan, one site in Monroe, Michigan, and one site in Palm Coast, Florida. Our study investigated previously undescribed eukaryotic diversity in these habitats and further explored their bacterial communities. Mat samples and water parameters were collected from sulfur spring sites during the spring, summer, and fall of 2022. Cyanobacteria and diatoms were cultured from mat subsamples to create a culture‐based DNA reference library. Remaining mat samples were used for metabarcoding of the 16S and rbc L regions to explore bacterial and diatom diversity, respectively. Analyses of water chemistry, alpha diversity, and beta diversity articulated a range of high‐sulfur, low‐oxygen habitats, each with distinct microbial communities. Conductivity, pH, dissolved oxygen, temperature, sulfate, and chloride had significant influences on community composition but did not describe the differences between communities well. Chloride concentration had the strongest correlation with microbial community structure. Mantel tests revealed that biogeography contributed to differences between communities as well. Our results provide novel information on microbial mat composition and present evidence that both local conditions and biogeography influence these unique communities.
... The name of Phormidium was considered an invalid name due to more than 100 years of taxonomic confusion 40 . However, Casamatta et al. (2005) 41 did not agree with the fact totally but concluded that generic and subgeneric categorizations in this genus should not essentially correspond to systematic relations. The genus was revised and grouped using morphological and ultrastructural criteria to ease the identification process 1 . ...
Filamentous non-heterocystous cyanobacterial taxa from 8 genera were collected from different ecological niches like high altitudes, plains and estuaries of eastern India. The systematic accounts of 23 taxa were investigated with a polyphasic approach considering morpho taxonomy, cultural behavior, and molecular phylogenetic analysis with 16S and 16S-23S Internal Transcribed Spacer (ITS) regions as molecular markers. The collected taxa were from the families Oscillatoriaceae, Phormidiaceae and Pseudanabaenaceae with 8 representative genera viz. Lyngbya, Plectonema, Oscillatoria, Limnothrix, Leptolyngbya, Planktothrix, Desertifilum and Phormidium. The 16S-23S ITS region-based molecular characterization of 13 species from Oscillatoriaceae, 6 species from Phormidiaceae, and 4 species from Pseudanabaenaceae were found to be congruent with earlier phylogenetic studies using other markers. Phylogenetic tree analysis revealed habitat-specific clustering of ITS sequences of the investigated taxa. The 16S molecular marker-based phylogenetic analysis, along with cultural studies of the Lyngbya-Plectonema clade, highlighted the need for morphotaxonomic reconsideration of Lyngbya birgei and Plectonema tomasinianum related to the formation of false branching. The present study affirmed that 98% sequence similarity in the ITS region can be considered as a threshold percentage for conspecificity determination in the Lyngbya genus. Keywords: Cyanobacteria; ITS; Oscillatoriaceae; Phormidiaceae; Phylogenetic tree; Pseudanabaenaceae.
... The name of Phormidium was considered an invalid name due to more than 100 years of taxonomic confusion 40 . However, Casamatta et al. (2005) 41 did not agree with the fact totally but concluded that generic and subgeneric categorizations in this genus should not essentially correspond to systematic relations. The genus was revised and grouped using morphological and ultrastructural criteria to ease the identification process 1 . ...
Filamentous non-heterocystous cyanobacterial taxa from 8 genera were collected from different ecological niches like high altitudes, plains and estuaries of eastern India. The systematic accounts of 23 taxa were investigated with a polyphasic approach considering morpho taxonomy, cultural behavior, and molecular phylogenetic analysis with 16S and 16S-23S Internal Transcribed Spacer (ITS) regions as molecular markers. The collected taxa were from the families Oscillatoriaceae, Phormidiaceae and Pseudanabaenaceae with 8 representative genera viz. Lyngbya, Plectonema, Oscillatoria, Limnothrix, Leptolyngbya, Planktothrix, Desertifilum and Phormidium. The 16S-23S ITS region-based molecular characterization of 13 species from Oscillatoriaceae, 6 species from Phormidiaceae, and 4 species from Pseudanabaenaceae were found to be congruent with earlier phylogenetic studies using other markers. Phylogenetic tree analysis revealed habitat-specific clustering of ITS sequences of the investigated taxa. The 16S molecular marker-based phylogenetic analysis, along with cultural studies of the Lyngbya-Plectonema clade, highlighted the need for morphotaxonomic reconsideration of Lyngbya birgei and Plectonema tomasinianum related to the formation of false branching. The present study affirmed that 98% sequence similarity in the ITS region can be considered as a threshold percentage for conspecificity determination in the Lyngbya genus. Keywords: Cyanobacteria; ITS; Oscillatoriaceae; Phormidiaceae; Phylogenetic tree; Pseudanabaenaceae
... With the gradual application of electron microscopy and 16S rRNA gene sequence analyses, the cyanobacterial taxonomic system has undergone extensive reconstruction and revision in recent decades (Anagnostidis & Komárek 1985;Komárek et al. 2014). Modern cyanobacterial taxonomy seeks to establish monophyletic groups at order, family, genus, and species levels, and in this regard, a polyphasic approach, which combines morphological, ecological, molecular sequence, and phylogenetic analyses, has gradually emerged as the most suitable strategy for characterizing and describing cyanobacterial taxa (Anagnostidis & Komárek 1985;Casamatta et al. 2005;Siegesmund et al. 2008;Perkerson et al. 2011;Komárek et al. 2014). ...
... Many of the morphological characteristics that were traditionally used as indicators of phylogeny have been proven to be variable. Additionally, phylogenetic reconstructions demonstrated that a large number of genera previously regarded to have consistent morphological traits were polyphyletic [6,7]. These polyphyletic genera, sometimes referred to as cryptogenera, may have resulted from multiple lineages of cyanobacteria undergoing frequent evolutionary convergence [8][9][10]. ...
During the study of diversity in filamentous cyanobacteria in China, two strains (WZU0719 and WZU0723) with the form of thin filaments were isolated from the surface of Qiandao Lake, a large freshwater lake in Zhejiang Province, China. A comprehensive analysis was conducted, incorporating morphological, ecological, and molecular data. The morphological examination provided an initial identification as a Leptolyngbya-like cyanobacterium. Genetic characterization was also performed by amplifying the 16S rRNA gene and the 16S-23S rRNA internal transcribed spacer (ITS) region. The phylogenetic grouping based on the 16S rRNA gene demonstrates that the examined strain is unequivocally assigned to the Pegethrix genus. However, it possesses distinct phylogenetic divergence from the six described Pegethrix species. Additionally, discrepancies in habitat further differentiate it from other members of this genus. Employing the polyphasic approach, we present a comprehensive account of the newly discovered taxa: Pegethrix qiandaoensis sp. nov. The novel taxonomic finding in this research significantly contributes to enhancing the comprehension of Pegethrix diversity across various habitats.
... Most of the filamentous taxa in the Synechococcales are cryptic in nature: they share a similar set of morphological features but are genetically very different. Leptolyngbyaceae is the largest family of Synechococcales, and it has been examined more intensively than any other synechococcalean families in recent times, in an attempt to establish monophyletic taxa (Casamatta et al. 2005;Johansen et al. 2008;Zammit et al. 2012;Komárek et al. 2014). Family-level taxonomic evaluation was performed and four monophyletic families, consisting of the two previously described families Leptolyngbyaceae and Prochlorotrichaceae, and the two new families Oculatellaceae and Trichocoleaceae, were proposed based on the polyphasic approach of taxonomic studies (Mai et al. 2018). ...
Three simple filamentous cyanobacteria (strains S1, S6 and S10) were isolated from the upper surface of intertidal soil of an Indian mangrove forest, the Sundarbans. The three cyanobacterial strains formed a new cluster within the phylogenetic tree calculated based on 16S rRNA gene sequences, which was distinctive from the clade of the ecologically and morphologically most similar genus, Euryhalinema. Moreover, the sequence similarity of 16S rRNA gene was less than 94.4% compared with the reference strain of Euryhalinema, which confirmed that the new strains belonged to a novel genus. The folded secondary structure of D1-D1’, Box-B and V3 helices of the internal transcribed spacer (ITS) region were different from those of Euryhalinema and other members of family Nodosilineaceae. P-distance analysis of the ITS region of the test strains showed 22.2% dissimilarity with the reference genus Euryhalinema,
which exceeded the cut off (7%) and strongly supported that it is a novel species within a novel genus.
Differential morphological and ultrastructural characters, such as the presence of various cellular inclusions
(prominent large cyanophycin granule, glycogen α granules, lipid β granules and mucilaginous
sheath), conical-shaped apical cell as well as cell width, supported the description of a new taxon.
Therefore, based on morphological, ultrastructural and molecular analysis we propose that cyanobacterial
strains S1, S6 and S10 belong to a new monophyletic genus and species Almyronema epifaneia gen.
& sp. nov., in the recently established family Nodosilineaceae.
... Однако многие исследователи отмечают трудности как с выделением изолятов цианобактерий в лабораторные культуры, так и с их последующим изучением молекулярно-генетическими методами (Rippka et al., 1979;Komárek et al., 2008;Cornet et al., 2018). В частности, трудно изолируемыми считаются некоторые коккоидные и плеврокапсовые формы, в то время как нитчатые гомоцитные цианобактерии успешнее культивируются в лабораторных условиях (Gordon et al., 2000;Nadeau et al., 2001;Casamatta et al., 2005;Jungblut et al., 2005;Taton et al., 2006Taton et al., , 2011. В связи с этим, изучение водорослевых сообществ необходимо начинать с описания состава, структуры и морфологических особенностей образующих его видов, которые в дальнейшем следует идентифицировать с помощью культуральных и молекулярно-генетических методов. ...
... Furthermore, the new genus is phylogenetically distant from the strain used to describe the genus Arthronema (CCALA 020). The phylogenetic position of known Arthronema strains, the closest morphologic genus, presents some challenges: (1) A. africanum SAG 12.89 formed a separate and distinct clade in the Leptolyngbyaceae; (2) A. gygaxiana, described in Casamatta et al. (2005) depicting the characteristic involution cells, was positioned within the Pseudanabena spp. clade; and (3) A. africanum SAG 1.89 and A. africanum CCALA 020 were placed in the Leptolyngbya sensu stricto clade, a well-defined and recognized clade containing the type species L. boryana. ...
Simple filamentous cyanobacteria comprise a diverse and polyphyletic group of species, primarily in the orders Leptolyngbyales and Oscillatoriales, that need more sampling to improve their taxonomy. Oceanic islands, such as the Azores archipelago, present unique habitats and biogeographic conditions that harbor an unknown range of diversity of microorganisms. Filamentous cyanobacteria isolated from aquatic habitats in the Azores and maintained in the BACA culture collection were described using morphology, both light and transmission electron microscopy, ecology, and genetic data of the 16S rRNA gene sequences and 16S-23S Internal Transcribed Spacer (ITS) rRNA region secondary structure. Our analyses revealed two new monophyletic genera: Tumidithrix elongata gen. sp. nov. (Pseudanabaenaceae) and Radiculonema aquaticum gen. sp. nov. (Leptolyngbyaceae). In addition, two new species Leptodesmis lacustris sp. nov. (Leptolyngbyaceae) and Pycnacronema la-custrum sp. nov. (Wilmottiaceae) are reported as the first aquatic species for these genera. The description of these new taxa and the genetic study of an isolate of Leptodesmis alaskaensis from the Azores followed the polyphasic approach, identifying diacritical features. Our results reinforce the need for taxonomic studies on cyanobacteria from less-studied habits and geographic regions, which have a potential for new taxa description.
... The genus should be narrowed to just those species belonging to the same clade as the type species, L. boryana (Gomont) Anagnostidis & Komárek [36]. This species has been sequenced and is quite close to other species in the genus, including L. angustata Casamatta & Johansen [55], L. corticola Johansen, Kováčik, Cassamata, Fučíková & Kaštovský [56], L. foveolarum (Gomont) Anagnostidis & Komárek [36] and L. tenerrima (Hansgirg) Komárek [57]. Plectolyngbya is phylogenetically very close to Leptolyngbya, but was initially recognized for its double false branching. ...
: In 2019, cyanobacterial samples were collected from thermal sites in Yellowstone National Park. In this paper, we discuss the considerable richness of representatives of simple filamentous cyanobacteria. Using a polyphasic approach, one new genus, Copelandiella, with two species (C. yellowstonensis and C. thermalis) and eight additional new species Albertania prattii, K. anagnostidisii, Kovacikia brockii, Leptolyngbya tildenae, L. vaporiphila, Nodosilinea calida, N. igneolacustris, and Oculatella castenholzii were described. At the same time, by analyzing our new molecular data, we concluded that other genera of trichal cyanobacteria can be merged with existing genera: species within the genus Plectolyngbya are herein transferred to Leptolyngbya, and if some nomenclatural issues are resolved, species within the genus Leptothermofonsia will be subsequently transferred to the genus Kovacikia, an earlier synonym.
... To better understand the role of these Oscillatorean cyanobacteria in the Water Diversion Process, it is much necessary to accurately describe and correctly characterize them based on the modern cyanobacterial taxonomy. Modern cyanobacterial taxonomic system aims to accurately identify and revise the complex polyphyletic taxa (families, genera, and species) in cyanobacteria, and promote the classification system to monophyletic, clear, and narrowly defined levels (Anagnostidis and Komárek, 1985;Casamatta et al., 2005;Siegesmund et al., 2008;Komárek et al., 2014). The current taxonomy system does not solve the polyphyletic origination in cyanobacteria at the family and genus level. ...
A new filamentous cyanobacterial strain (CHAB 4127) was successfully isolated from the algal mat during the field investigation of the open channel from Luanhe River to Tianjin, China. The polyphasic approach combining morphological, ultrastructural, ecological, and molecular features was used to characterize this studied strain. The strain is morphologically similar to the Microcoleus-like cyanobacterial taxa under light microscopy, and the radial arrangement of thylakoids is also consistent with that of Microcoleus-like groups. The phylogenetic position of CHAB 4127 based on 16S rRNA gene sequences, is shown to be clearly clustered into an independent clade with the newly established genus Microcoleusiopsis. The maximum similarity of 16S rRNA gene of the studied strain with other existing related cyanobacterial taxa is 93.97%, and the ITS secondary structures is also obviously different from other members of Microcoleaceae. Based on all the above evidence, we proposed the establishment of this novel cyanobacterial genus as Neomicrocoleus, with its type species, Neomicrocoleus tianjinensis.
