1,721,143 research outputs found
Cyanobacteria: the bright and dark sides of a charming group.
No full textThis is an invited review focusing on the phylum Cyanobacteria
Detection of the new cosmopolitan genus Thermoleptolyngbya (Cyanobacteria, Leptolyngbyaceae) using the 16S rRNA gene and 16S–23S ITS region
No full textCyanobacteria are widespread prokaryotes that are able to live in extreme conditions such as thermal
springs. Strains attributable to the genus Leptolyngbya are among the most common cyanobacteria sampled
from thermal environments. Leptolyngbya is a character-poor taxon that was demonstrated to be
polyphyletic based on molecular analyses. The recent joining of 16S rRNA gene phylogenies with 16S–
23S ITS secondary structure analysis is a useful approach to detect new cryptic taxa and has led to the
separation of new genera from Leptolyngbya and to the description of new species inside this genus
and in other related groups.
In this study, phylogenetic investigations based on both the 16S rRNA gene and the 16S–23S ITS region
were performed alongside 16S rRNA and 16S–23S ITS secondary structure analyses on cyanobacteria of
the family Leptolyngbyaceae. These analyses focused on filamentous strains sampled from thermal
springs with a morphology ascribable to the genus Leptolyngbya. The phylogenetic reconstructions
showed that the Leptolyngbya-like thermal strains grouped into a monophyletic lineage that was distinct
from Leptolyngbya. The 16S–23S ITS secondary structure results supported the separation of this cluster.
A new genus named Thermoleptolyngbya was erected to encompass these strains, and two species were
described inside this new taxon: T. albertanoae and T. oregonensis
Some effects of cadmium on Ulva laetevirens Areschoug collected in Lagoon of Venice.
No full textAlthough water bodies are a major vehicle for contamination by cadmium (Cd), works on the morpho-physiological effects of this heavy metal on macroalgae are still very scarce. The aim of this research was to study the damaging effects of 9 day-experimental exposure to 1, 5, 10 and 100 μM of Cd on thalli of Ulva laetevirens Areschoug, a macroalga which grows abundantly in the Lagoon of Venice where heavy metals are found. Cd-treated thalli, compared with control thalli, were less thick and less pigmented, due to reduced chlorophyll contents. These symptoms became more evident as the Cd concentration in the seawater growth medium increased. In proportion to that concentration, thalli accumulated great quantities of the metal, most of which remained outside the cells, bound to anionic polysaccharides in cell walls. In particular, 10 and 100 μM Cd disturbed cell wall organization, affecting the fibrous component, and impaired the thylakoid system of chloroplasts
Risposte morfo-fisiologiche di Scenedesmus rubescens a diverse concentrazioni di ibuprofene.
No full textPolyphasic characterization of a Dixoniella (Dixoniellaceae, Rhodophyta) strain isolated from the Mediterranean Sea
No full textA polyphasic approach was carried out on a Dixoniella (Rhodophyta) strain isolated from the Adriatic Sea and revealed the existence of a new species inside this genus
Cicli nictemerali stagionali nella Laguna di Venezia, bacino di Chioggia (Idrologia e fitoplancton).
No full textDuring four different seasonal periods, samplings were carried out in 24 hours in a sampling station located in the Southern basin of the Venice Lagoon to study the variability of the environmental parameters and the quali-quantitative composition of the phytoplankton.
This study was carried out also to compare the results with those obtained during other samplings as far as the flood and ebb tides.
In the study area the results did not follow the cyclicity expected by the tide trend: anomalies and irregularities confirm that in the sampling stations involved in the water transit and during the syzygy, running and rip water mainly influence not only the abiotic parameters but also the phytoplanktonic communities of these environments
Survey on a microalga collected from an Edmonson Point pond (Victoria Land, Antarctica).
No full textPhytoplancton de la lagune de Venise. II-Bassin Central (Avril 1989-Mars 1990).
No full textTo continue the research on the lagoonal phytoplanktonic communities, we carried out monthly samplings (from April 1989 to March 1990) on four sampling stations, located in the central basin (Malamocco basin) of the Venice lagoon, during the flood and the ebb tide. The same methods were used during the present work and the previous research to compare the results.
Environmental parameters showed the influence of the sea water also in the inner areas. Phytoplankton was influenced by the environment: there were many eupelagic species; the freshwater species, instead, were not abundant. Phytoplankton was constituted by 258 taxa, 75% of them were diatoms. During the summer the phytoplanktonic densities were often higher than 5x105 cells/ml; during the cold season, we registered high density values only in March, due to a bloom of Skeletonema costatum. This diatom was very abundant during the same period also in the Northern and in the Southern basins of the lagoon. Diatoms were present during all the year with fluctuations different among the stations. Microflagellates sometimes were more abundant than diatoms; the other groups, included Dinoflagellates and Euglenophyceans did not show significant density values
A new species of Streblospio (Polychaeta: Spionidae) from the northern Adriatic Sea (Mediterranean Sea)
No full textMunari, Cristina, Wolf, Marion A., Infantini, Vanessa, Moro, Isabella, Sfriso, Adriano, Mistri, Michele (2020): A new species of Streblospio (Polychaeta: Spionidae) from the northern Adriatic Sea (Mediterranean Sea). Zootaxa 4742 (1): 149-167, DOI: https://doi.org/10.11646/zootaxa.4742.1.1
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