A terrestrial green microalga was isolated at Ås, in Akershus County, Norway. The strain corresponded to a coccoid chlorophyte. Morphological characteristics by light and electron microscopy, in conjunction with DNA amplification and sequencing of the 18 s rDNA gene and ITS sequences, were used to identify the microalgae. The characteristics agree with those of the genus Coelastrella defined by Chodat, and formed a sister group with the recently described C. thermophila var. globulina. Coelastrella is a relatively small numbered genus that has not been observed in continental Norway before; there are no previous cultures available in collections of Norwegian strains. Gas chromatography analyses of the FAME-derivatives showed a high percentage of polyunsaturated fatty acids (44-45%) especially linolenic acid (C18:3n3; 30-34%). After the stationary phase, the cultures were able to accumulate several carotenoids as neoxanthin, pheophytin a, astaxanthin, canthaxanthin, lutein, and violaxanthin. Due to the scarcity of visual characters suitable for diagnostic purposes and the lack of DNA sequence information, there is a high possibility that species of this genus have been neglected in local environmental studies, even though it showed interesting properties for algal biotechnology.
- MeSH
- biologické pigmenty analýza MeSH
- biotechnologie MeSH
- Chlorophyta klasifikace cytologie genetika MeSH
- druhová specificita MeSH
- feofytiny analýza MeSH
- fylogeneze * MeSH
- karotenoidy analýza MeSH
- kyselina alfa-linolenová analýza MeSH
- mastné kyseliny analýza MeSH
- mikrořasy klasifikace cytologie genetika izolace a purifikace MeSH
- ribozomální DNA MeSH
- RNA ribozomální 18S genetika MeSH
- xanthofyly MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Norsko MeSH
Magnetic harvesting of microalgal biomass provides an attractive alternative to conventional methods. The approach to this issue has so far been pragmatic, focused mainly on finding cheap magnetic agents in combination with harvestable microalgae species. The aim of this work was to study experimentally and theoretically the mechanisms leading to cell-magnetic agent attachment/detachment using real experiments and predictions made by colloidal adhesion (XDLVO) model. Two types of well defined magnetic beads (MBs) carrying ion exchange functional groups (DEAE - diethylaminoethyl and PEI - polyethylenimine) were studied in connection with microalgae (Chlorella vulgaris). Optimal harvesting efficiencies (>90%) were found for DEAE and PEI MBs, while efficient detachment was achieved only for DEAE MBs (>90%). These findings were in accordance with the predictions by XDLVO model. Simultaneously there was found a discrepancy between the XDLVO prediction and the poor detachment of PEI MBs from microalgal surface. This can be ascribed to an additional interaction (probably covalent bonds) between PEI and algal surface, which the XDLVO model is unable to capture given by its non-covalent nature.
- MeSH
- biologické modely MeSH
- biomasa MeSH
- buněčná adheze MeSH
- Chlorella vulgaris izolace a purifikace fyziologie MeSH
- ethanolaminy chemie MeSH
- iontová výměna MeSH
- koloidy MeSH
- magnetické jevy MeSH
- magnetické nanočástice chemie MeSH
- mikrořasy izolace a purifikace fyziologie MeSH
- polyethylenimin chemie MeSH
- povrchové vlastnosti MeSH
- průmyslová mikrobiologie metody MeSH
- sladká voda mikrobiologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Microscopic investigations were undertaken to decipher the diversity in the lotic algal communities from acidic waters (pH 2.4-3.2) flowing overland in sheets and channels at an acid mine drainage (AMD) barrens near Kylertown, PA, USA. Microscopic observations, supplemented with taxonomic keys, aided in identification of the dominant algae, and measurement of carbon from adjacent soils was undertaken. The unicellular protist Euglena sp. was most abundant in slower flowing waters (i.e., pool near point of emergence and surficial flow sheets), while Ulothrix sp. was most abundant in faster flowing water from the central stream channel. A diverse range of unicellular microalgae such as Chlorella, Cylindrocystis, Botryococcus, and Navicula and several filamentous forms identified as Microspora, Cladophora, and Binuclearia were also recorded. The observed high algal diversity may be related to the long duration of AMD flow at this site which has led to the development of adapted algal communities. The comparatively higher carbon content in soil materials adjacent to slower flowing water sampling locations provides evidence for the important role of algae as primary producers in this extreme environment.
- MeSH
- biodiverzita MeSH
- Chlorophyta klasifikace cytologie MeSH
- hornictví MeSH
- mikrořasy klasifikace cytologie izolace a purifikace MeSH
- půda chemie MeSH
- voda chemie MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Pennsylvania MeSH
