Nodosilinea signiensis sp. nov. (Leptolyngbyaceae, Synechococcales), a new terrestrial cyanobacterium isolated from mats collected on Signy Island, South Orkney Islands, Antarctica

Abstract

Terrestrial cyanobacteria are very diverse and widely distributed in Antarctica, where they can form macroscopically visible biofilms on the surfaces of soils and rocks, and on benthic surfaces in fresh waters. We recently isolated several terrestrial cyanobacteria from soils collected on Signy Island, South Orkney Islands, Antarctica. Among them, we found a novel species of Nodosilinea, named here as Nodosilinea signiensis sp. nov. This new species is morphologically and genetically distinct from other described species. Morphological examination indicated that the new species is differentiated from others in the genus by cell size, cell shape, filament attenuation, sheath morphology and granulation. 16S rDNA phylogenetic analyses clearly confirmed that N. signiensis belongs to the genus Nodosilinea, but that it is genetically distinct from other known species of Nodosilinea. The D1–D1´ helix of the 16S–23S ITS region of the new species was also different from previously described Nodosilinea species. This is the first detailed characterization of a member of the genus Nodosilinea from Antarctica as well as being a newly described species.

Coexistence of Synechococcus and Microcystis Blooms in a Tropical Urban Reservoir and Their Links with Microbiomes

“…The higher proportion of filamentous cyanobacteria observed in downstream water may be due to the lower nitrogen availability favoring the growth of nitrogen fixers. This is in line with our observation that all the major filamentous cyanobacteria ( Nodosilinea , Planktothricoides , and Raphidiopsis ) are capable of fixing nitrogen. − In terms of coccoid taxa, the increased downstream Synechococcus populations might be a dual effect of the lower nitrogen condition. Synechococcus has better nitrogen assimilation due to a higher surface-to-volume ratio, whereas Microcystis lost colony and buoyancy advantage when nitrogen was limiting …”

Influence of Abiotic Factors on the Growth of Cyanobacteria Isolated from Nakdong River, South Korea1

“…The morphological identification of cyanobacterial isolates was made by using an optical light microscope (Olympus CX 40, Japan) equipped with a digital camera and imaging system (IMTi-solution Inc., Japan). Different parameters of isolated strains were studied for morphological identifications like cell size, cell organization, cell morphology, and color (Radzi et al 2019).…”

“…Different parameters of isolated strains were studied for morphological identifications like cell size, cell organization, cell morphology, and color (Radzi et al. 2019).…”

Comparative growth characteristics and interspecific competitive interaction of two cyanobacteria, Phormidium autumnale and Nostoc sp.

“…The isolated strains were identified morphologically using an optical microscope (CX 40O, Olympus) equipped with a digital camera and imaging system (IMTi Solution, Inc.). The isolates were examined for morphological identifications based on the cell organization, morphology, size, and color (Radzi et al., 2019).…”