Search results for "DINOFLAGELLATE"
showing 10 items of 20 documents
Suitability of Phytosterols Alongside Fatty Acids as Chemotaxonomic Biomarkers for Phytoplankton
2016
The composition and abundance of phytoplankton is an important factor defining ecological status of marine and freshwater ecosystems. Chemotaxonomic markers (e.g., pigments and fatty acids) are needed for monitoring changes in a phytoplankton community and to know the nutritional quality of seston for herbivorous zooplankton. Here we investigated the suitability of sterols along with fatty acids as chemotaxonomic markers using multivariate statistics, by analyzing the sterol and fatty acid composition of 10 different phytoplankton classes including altogether 37 strains isolated from freshwater lakes. We were able to detect a total of 47 fatty acids and 29 sterols in our phytoplankton sampl…
Organische und kalkige Dinoflagellaten-Zysten aus den Böhlen-Schichten (Rupelium/Oligozän) der Leipziger Bucht (NW-Sachsen/Deutschland)
1996
Rupelian organic-walled and calcareous dinoflagellate cysts from two profiles (brown coal open cast minings Cospuden and Zwenkau) in the Bohlen-Schichten of the Leipzig Bay (E-Germany) are discussed. The sediments of these profiles were deposited in literal to sublitoral areas. The dinoflagellate cysts of Cospuden characterize a nearshore environment, while the associations of Zwenkau are more typical for offshore conditions.
Palynological variations and sedimentary cycles in the Jurassic from the Paris basin
1995
Abstract Two studies, one on Hettangian dolomitic cap rocks over “Gaz de France” gas storage reservoir rocks at Sologne, and the other on two separate sections in Dogger formations in Burgundy, conducted at the Palynology Laboratory of Strasbourg, illustrate that a palynological approach can lead to a considerable refinement of knowledge in sequence stratigraphy. The palynological study of the dolomitic cap rocks at Sologne dates them as Hettangian, distinguishes microfloristical assemblage types within the sequence, and establishes palynofacies variations with basin evolution. The evidence suggests that palynological variations in the Hettangian rocks are attenuated, reflecting restricted …
Dinoflagellates from marine algal blooms produce neurotoxic compounds: effects on free calcium levels in neuronal cells and synaptosomes
2000
In this report, evidence is presented that the marine unicellular eukaryotic dinoflagellates can cause neurotoxicity very likely by an increase in intracellular free calcium ions ([Ca(2+)](i)). Determinations of the effects of culture supernatants from different clones of the dinoflagellate Alexandrium sp. isolated from algal blooms on the viability of rat primary neuronal cells revealed that all clones tested were toxic for these cells. In addition, all Alexandrium clones tested, except for A. ostenfeldii BAH ME-141, were found to be toxic for rat pheochromocytoma PC12 cells. No toxicity was observed for culture supernatants from Gonyaulax and Coolia monotis. Calcium ions are important in …
Metal stresses modify soluble proteomes and toxin profiles in two Mediterranean strains of the distributed dinoflagellate Alexandrium pacificum
2022
WOS:000789651000009; HABs involving Alexandrium pacificum have been reported in metal-contaminated ecosystems, suggesting that this distributed species adapts to and/or can tolerate the effects of metals. Modifications in soluble proteomes and PST contents were characterized in two Mediterranean A. pacificum strains exposed to mono- or polymetallic stresses (zinc, lead, copper, cadmium). These strains were isolated from two anthropized locations: Santa Giusta Lagoon (Italy, SG C10-3) and the Tarragona seaport (Spain, TAR C5-4F). In both strains, metals primarily downregulated key photosynthesis proteins. Metals also upregulated other proteins involved in photosynthesis (PCP in both strains)…
Crypthecodinium cohnii Growth and Omega Fatty Acid Production in Mediums Supplemented with Extract from Recycled Biomass
2022
Crypthecodinium cohnii is a marine heterotrophic dinoflagellate that can accumulate high amounts of omega-3 polyunsaturated fatty acids (PUFAs), and thus has the potential to replace conventional PUFAs production with eco-friendlier technology. So far, C. cohnii cultivation has been mainly carried out with the use of yeast extract (YE) as a nitrogen source. In the present study, alternative carbon and nitrogen sources were studied: the extraction ethanol (EE), remaining after lipid extraction, as a carbon source, and dinoflagellate extract (DE) from recycled algae biomass C. cohnii as a source of carbon, nitrogen, and vitamins. In mediums with glucose and DE, the highest specific biomass gr…
Bacteria of the Genus Roseobacter Associated with the Toxic Dinoflagellate Prorocentrum lima
1998
The dinoflagellate Prorocentrum lima is known to produce diarrhetic shellfish poisons. However, it is yet unclear if the dinoflagellates themselves or the bacteria associated with them produce the toxins. Here we analyze the toxicity as well as the spectrum of bacteria in two cultures of P. lima, namely P. lima-SY and P. lima-ST, which initially derived from the same P. lima strain PL2V. Toxicity tests, applying the Artemia bioassay revealed in both cultures high levels of toxins. The bacteria, associated with the two cultures, were identified by PCR/nucleotide sequence analysis of the 16S rRNA gene. From cultures of P. lima-SY the dominant sequence was found to share a 93.7% similarity wit…
REINSTATEMENT OF THE DINOFLAGELLATE GENUS Tripos TO REPLACE Neoceratium, MARINE SPECIES OF Ceratium (DINOPHYCEAE, ALVEOLATA)
2013
Morphological and molecular data support the split at the genus level of the marine and freshwater species of the dinoflagellate Ceratium (Gonyaulacales, Dinophyceae). A new genus name Neoceratium F. Gomez, D. Moreira & P. Lopez-Garcia was proposed for the marine species. However, it is considered illegitimate (type species is type of Biceratium Vanhoffen), and the nomenclatural priority is here given for the genus Tripos Bory (type species Tripos muelleri ) which replaces Neoceratium . New combinations are proposed for the existing names of species and infraspecific taxa. Reinstalacion del genero de dinoflagelados Tripos para reemplazar a Neoceratium , especies marinas de Ceratium (Dinophy…
Influence of dissolved organic matter from terrestrial origin on the changes of dinoflagellate species composition in the Gulf of Riga, Baltic Sea
2004
A mesocosm experiment was used to investigate the effect of terrestrial-origin dissolved organic matter (DOM) on the development of dinoflagellates in natural summer phytoplankton from the Gulf of Riga. Seawater was collected in the central part of the Gulf of Riga and at the entrance of the Gulf in June 1999. DOM was extracted from Parnu River water by use of tangential ultrafiltration. Experimental series were enriched with DOM, DOM in combination with nitrate and phosphate, and only with inorganic nutrients. Enrichments were added in ranges of their natural concentrations. Dinophysis acuminata, Protoperidinium brevipes and Gymnodinium spp. were dominant species in the initial dinoflagell…
Integrated stratigraphy of the Oxfordian global stratotype section and point (GSSP) candidate in the Subalpine Basin (SE France).
2014
44 pages; International audience; An integrated biostratigraphic approach, based on ammonites, calcareous nannofossils, dinoflagellates, combined with sedimentology, carbon-isotope and physical stratigraphy, is proposed for the Subalpine Basin (Thuoux and Saint-Pierre d'Argençon sections). Within the expanded marl deposits of the Terres Noires Fm., the Callovian-Oxfordian boundary is particularly well defined by ammonite taxa from different families (i.e. Cardioceratidae, Oppeliidae, Aspidoceratidae and Perisphinctidae), calcareous nannoplankton (first occurrence of large-sized Stephanolithion bigotii) and dinoflagellate cysts (first occurrence of Wanaea fimbriata). This precise biostratigr…