Strains of the cyanobacterial genus Calothrix display pronounced tapering filaments. These cyanobacteria are benthic, have a worldwide distribution and are among the most easily recognizable cyanobacterial genera. However, it is not clear whether cyanobacterial strains assigned to the genus Calothrix constitute a natural monophyletic group. We sequenced 16S rRNA genes from 42 cyanobacterial cultures and environmental samples belonging to the genus Calothrix, and the morphologically similar genera Rivularia, Gloeotrichia and Tolypothrix. Phylogenetic analysis of the 16S rRNA gene identified large sequence diversity among the Calothrix morphotype strains. Our results demonstrate that Calothrix, Gloeotrichia and Tolypothrix do not form a monophyletic group but instead display a high level of genetic diversity. The evolutionary distances between cyanobacteria, morphologically identified as Calothrix, suggest that they belong to at least five different genera. Our results also suggest that the genus Gloeotrichia is distantly related to the genus Calothrix. We found correlations between genetic grouping and morphology in redundancy analysis. However, morphology alone was not sufficiently reliable to distinguish strains from different 16S rRNA gene clusters. The high level of diversity that we observed confirms the hypothesis that the Rivulariaceae are species rich.
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http://dx.doi.org/10.1111/j.1574-6941.2007.00321.x | DOI Listing |
J Phycol
October 2024
Department of Biology, John Carroll University, University Heights, Ohio, USA.
Two new species of Dulcicalothrix, D. adhikaryi sp. nov.
View Article and Find Full Text PDFWater Res
August 2024
State Key Laboratory of Soil and Sustainable Agriculture, Changshu National Agro-Ecosystem Observation and Research Station, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China. Electronic address:
Organic phosphorus (Po) mineralization hydrolyzed by alkaline phosphatase (APase) can replenish bioavailable P load in the sediment water ecosystem of lakes. However, the understanding about the interaction between P load and bacteria community encoding APase generation in the sediment are still limited. Different P pools in the sediments from Taihu Lake, China were measured using sequential extraction procedure.
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May 2022
Department of Botany, School of Biology, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece. Electronic address:
Well-studied thermal spring microbial mat systems continue to serve as excellent models from which to make discoveries of general importance to microbial community ecology in order to address comprehensively the question of "who is there" in a microbial community. Cyanobacteria are highly adaptable and an integral part of many ecosystems including thermal springs. In this context, we sampled disparate thermal springs, spanning from Iceland and Poland to Greece and Tajikistan.
View Article and Find Full Text PDFFEMS Microbiol Lett
June 2021
Laboratory of Cyanobacterial Systematics and Stress Biology, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi-221005, Uttar Pradesh, India.
A freshwater dwelling cyanobacterium (strain MKW3) was isolated from a sample collected from a water logged sugarcane field located in Malkapur, Karad, Maharashtra, India, and was characterized using a polyphasic approach. In the 16S rRNA gene phylogenetic analysis, strain MKW3 clustered with two misidentified strains-Nostoc sp. CENA239 and Calothrix sp.
View Article and Find Full Text PDFiScience
March 2021
Scripps Institution of Oceanography, UC San Diego, 8622 Kennel Way, La Jolla, CA 92037, USA.
Mangrove-dominated estuaries host a diverse microbial assemblage that facilitates nutrient and carbon conversions and could play a vital role in maintaining ecosystem health. In this study, we used 16S rRNA gene analysis, metabolic inference, nutrient concentrations, and δC and δN isotopes to evaluate the impact of land use change on near-shore biogeochemical cycles and microbial community structures within mangrove-dominated estuaries. Samples in close proximity to active shrimp aquaculture were high in NH , NO NO , and PO ; lower in microbial community and metabolic diversity; and dominated by putative nitrifiers, denitrifies, and sulfur-oxidizing bacteria.
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