1,721,106 research outputs found
FISH methods in phycology: Phototrophic biofilm and phytoplankton applications
No full textMany photosynthetic microorganisms, living attached to immersed substrates or free in the water column, lack distinct morphological details, are small in size and often unculturable. Thus, whole-cell fluorescence in situ hybridization (FISH) with rRNA-targeted oligonucleotide probes has become a valuable and widely used technique to identify bacteria and protists within their natural communities. FISH methods not only allow direct, cultivation independent determination of community composition, but provide spatio-temporal quantification of microorganisms in the environment. Coupling of FISH techniques to Confocal Laser Scanning Microscopy (CLSM) has become essential for the assessment of diversity and structural integrity in three-dimensional complex biofilm samples. Combining FISH with microautoradiography (FISH-MAR) and microsensors also opens new perspectives in microbial ecology by providing new tools for revealing physiological properties of organisms with single-cell resolution. This paper briefly summarizes the application of FISH methods to phototrophic biofilm and phytoplankton research. The potential of DNA microarray technology in phycological research is highlighted, especially for the fast and accurate identification of HAB (Harmful Algal Bloom) species in marine phytoplankton. Some CLSM and FISH data from phototrophic biofilms from an Italian wastewater treatment plant are shown
Microphytobenthic biomass diversity and exopolymeric substances in a shallow dystrophic coastal lagoon
No full textA Biorefinery Approach to Extract Multiple Bioactive Compounds from the diatom Staurosirella Pinnata for Drug Discovery
No full textBENTOX-NET: A RESEARCH AND MANAGEMENT INITIATIVE ON OSTREOPSIS spp. and other benthic microalgal blooms along the Italian coast
No full textCyanobacterial biofilms in sewage treatment plants along the Tyrrhenian coast (Mediterranean Sea) Italy
No full textOn the presence of Phalacroma rotundatum in the southern Adriatic Sea (Italy)
Full text linkThe genus Dinophysis sensu lato is often involved in episodes of Diarrhetic Shellfish Poisoning (DSP) contaminations and human intoxications. To date, several species of this genus have shown toxin production in the laboratory; however, it is likely that many others could have this capability. Phalacroma rotundatum (Claparede and Lachmann) Kofoid and Michener, allocated by some authors to the genus Dinophysis, is a non-photosynthetic species, which has the potential to produce okadaic acid and its derivatives DTX-1 and DTX-2. This species was observed for the first time along the southern Adriatic coast of Puglia (Italy) during a 2 yr monitoring program on potentially toxic phytoplankton. P. rotundatum dynamics was studied in relation to hydrobiological conditions; its seasonal changes appeared rather independent from chemico-physical factors, but were significantly associated with those of phytoflagellates. A toxicity test (Microtox system) on P. rotundatum cells proved negative
Light-induced changes in photosynthesis and structure of cyanobacteria cultured biofilms from an Italian wastewater treatment plant
No full textThe photosynthetic and light acclimation capability of phototrophic biofilms collected seasonally from the wastewater treatment plant (WWTP) of Fiumicino Airport (Rome, Italy) was tested in culture at different irradiance conditions. Photosynthesis versus Irradiance (P/I) curves were recorded on 15, 30 and 45 day aged communities and chlorophylls, carotenoids and phycobiliproteins quantified. Light microscopy observations were performed to evaluate inoculum species composition and taxonomic shifts over time in cultured biofilms. Phototrophs acclimated to different irradiances by varying the photosynthetic efficiency, maximum photosynthetic rate and pigment content. Community age and biomass variation also affected photosynthesis-light response. Marked shifts towards the prevalence of cyanobacteria were observed in summer and autumn biofilms kept at the highest experimental irradiances. Data indicated high productivity and acclimation potential of cultured phototrophic biofilms in view of their application for bioremediation technologies
Dynamics of Dinophysis sensu lato species (Dinophyceae) in a coastal Mediterranean environment (Adriatic Sea)
No full textSpecies of Dinophysis Ehrenberg sensu lato were collected opportunistically along the southern Adriatic coasts (Apulia, Italy) during a survey of phytoplankton community structure and dynamics carried out from 1995 to 1997. Most previous reports of Dinophysis spp. in the Adriatic Sea concentrated on northern populations, with few data available on phytoplankton inhabiting the southern coastal areas. Thus, the present study is the first on Dinophysis sensu lato species composition and spatio-temporal distribution in these essentially oligotrophic waters. Twelve Dinophysis species were identified; some of which can be assigned to the genus Phalacroma. Dinophysis sacculus, D. fortii, D. caudata, Phalacroma rotundatum and P. mitra are potentially producers of diarrhetic shellfish poisoning. Seasonal changes in Dinophysis and Phalacroma populations are presented, as well as their relationships with hydrographic and biotic factors. These dinoflagellates were associated with mixing conditions, low water temperatures and high nutrient inputs. Furthermore, the statistical analysis evidenced significant correlations of Dinophysis species to chlorophyll a and phytoplankton. Ecological implications arising from the data are discussed. (C) 2001 Elsevier Science Ltd. All rights reserved
Anti-viral and anti-cancer potentials of small metabolites from the mass cultivated diatoms Staurosirella pinnata and Cylindrotheca closterium
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