Melting summer snow in the Austrian Alps exhibited a yellowish bloom that was mainly comprised of an unidentified unicellular chrysophyte. Molecular data (18S rRNA and rbcL genes) showed a close relationship to published sequences from an American pond alga formerly identified as Kremastochrysis sp. The genera Kremastochrysis and Kremastochrysopsis are morphologically distinguished by the number of flagella observed with the light microscope, and therefore we assigned the Austrian snow alga and an American pond alga to the genus Kremastochrysopsis. Transmission and scanning electron microscopy revealed that swimming cells had two flagella oriented in opposite directions, typical for the Hibberdiales. Molecular phylogenetic analyses showed that both new species were closely related to Hibberdia. Kremastochrysopsis ocellata, the type species and only known species, has two chloroplasts per cell and the zoospores have red eyespots. Our two organisms had only a single chloroplast and no zoospore eyespot, but their gene sequences differed substantially. Therefore, we described two new species, Kremastochrysopsis austriaca sp. nov and Kremstochrysopsis americana sp. nov. When grown in culture, both taxa showed a characteristic hyponeustonic growth (hanging below the water surface), whereas older immotile cells grew at the bottom of the culture vessel. Ecologically, Kremastochrysopsis austriaca sp. nov., which caused snow discolorations, had no close phylogenetic relationships to other psychrophilic chrysophytes, for example, Chromulina chionophilia, Hydrurus sp., and Ochromonas-like flagellates.

• MeSH
• chloroplasty * MeSH
• Chrysophyceae * MeSH
• fylogeneze MeSH
• RNA ribozomální 16S MeSH
• RNA ribozomální 18S MeSH
• sekvenční analýza DNA MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Rakousko MeSH

In this study, a unicellular soil alga isolated from farmland in Germany was surveyed. The investigation of the hypervariable molecular markers ITS1 rDNA and ITS2 rDNA identified strain E71.10 as conspecific with Vischeria sp. SAG 51.91 (Eustigmatophyceae). The culture was tested for biomass generation and for the yield of fatty acids and amino acids. The survey included four different culture conditions (conventional, elevated CO2, nitrogen depletion, or sodium chloride stress) at room temperature. The best yield of dry biomass was achieved applying 1% CO2, whereas nitrogen-free medium resulted into least growth. The fatty acid content peaked in nitrogen-free medium at 59% per dry mass. Eicosapentaenoic acid was the most abundant fatty acid in all treatments (except for nitrogen free), accounting for 10.44 to 16.72 g/100 g dry mass. The highest content of amino acids (20%) was achieved under conventional conditions. The results show that abiotic factors strongly influence to which extent metabolites are intracellularly stored and they confirm also for this yet undescribed strain of Vischeria that Eustigmatophyceae are promising candidates for biotechnology.

• MeSH
• aminokyseliny metabolismus   MeSH
• biomasa MeSH
• biotechnologie MeSH
• dusík metabolismus   MeSH
• Heterokontophyta klasifikace   genetika   růst a vývoj   metabolismus   MeSH
• kultivační média chemie   MeSH
• kyselina eikosapentaenová analogy a deriváty   metabolismus   MeSH
• mastné kyseliny metabolismus   MeSH
• mikrořasy metabolismus   MeSH
• půda * MeSH
• ribozomální DNA MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Německo MeSH

Leporelo Máme doma zvířátko je druhým společným počinem hudebníka a spisovatele Josefa Pepsona Snětivého a známé autorky obrázků pro děti Lenky Procházkové. Stejně jako v případě svého prvního leporela Zvířátka ze ZOO představují oba autoři vtipnou a přístupnou formou domácí mazlíčky, a to dětem od nejmenších až po ty, které si verše rády přečtou samy. V leporelu najdou nejen obvyklá zvířátka našich domácností, jako jsou pes, kočka, křeček či andulka, ale i ta exotičtější, která zastupují třeba štír, chameleon nebo leguán.

Melting snowfields in polar and alpine regions often exhibit a red and orange colouration caused by microalgae. The diversity of these organisms is still poorly understood. We applied a polyphasic approach using three molecular markers and light and electron microscopy to investigate spherical cysts sampled from alpine mountains in Europe, North America and South America as well as from both polar regions. Molecular analyses revealed the presence of a single independent lineage within the Chlamydomonadales. The genus Sanguina is described, with Sanguina nivaloides as its type. It is distinguishable from other red cysts forming alga by the number of cell wall layers, cell size, cell surface morphology and habitat preference. Sanguina nivaloides is a diverse species containing a total of 18 haplotypes according to nuclear ribosomal DNA internal transcribed spacer 2, with low nucleotide divergence (≤3.5%). Based on molecular data we demonstrate that it has a cosmopolitan distribution with an absence of geographical structuring, indicating an effective dispersal strategy with the cysts being transported all around the globe, including trans-equatorially. Additionally, Sanguina aurantia is described, with small spherical orange cysts often clustered by means of mucilaginous sheaths, and causing orange blooms in snow in subarctic and Arctic regions.

• MeSH
• Chlorophyta klasifikace   genetika   fyziologie   MeSH
• ekosystém MeSH
• fylogeneze MeSH
• fylogeografie MeSH
• mezerníky ribozomální DNA MeSH
• Rhodophyta MeSH
• sníh mikrobiologie   MeSH
• zmrazování MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Evropa MeSH
• Jižní Amerika MeSH
• Severní Amerika MeSH

A highly prospective drug for the X-ray induced photodynamic therapy (PDTX), LuAG:Pr3+@SiO2-PpIX nanocomposite, was successfully prepared by a three step process: photo-induced precipitation of the Lu3Al5O12:Pr3+(LuAG:Pr3+) core, sol-gel technique for amorphous silica coating, and a biofunctionalization by attaching the protoporphyrin IX (PpIX) molecules. The synthesis procedure provides three-layer nanocomposite with uniform shells covering an intensely luminescent core. Room temperature radioluminescence (RT RL) spectra as well as photoluminescence (RT PL) steady-state and time resolved spectra of the material confirm the non-radiative energy transfer from the core Pr3+ions to the PpIX outer layer. First, excitation of Pr3+ions results in the red luminescence of PpIX. Second, the decay measurements exhibit clear evidence of mentioned non-radiative energy transfer (ET). The singlet oxygen generation in the system was demonstrated by the 3'-(p-aminophenyl) fluorescein (APF) chemical probe sensitive to the singlet oxygen presence. The RT PL spectra of an X-ray irradiated material with the APF probe manifest the formation of singlet oxygen due to which enhanced luminescence around 530 nm is observed. Quenching studies, using NaN3as an1O2inhibitor, also confirm the presence of1O2in the system and rule out the parasitic reaction with OH radicals. To summarize, presented features of LuAG:Pr3+@SiO2-PpIX nanocomposite indicate its considerable potential for PDTX application.

• MeSH
• fotosenzibilizující látky chemie   MeSH
• luminiscenční měření MeSH
• nanokompozity chemie   MeSH
• oxid křemičitý chemie   MeSH
• přenos energie MeSH
• protoporfyriny chemie   MeSH
• singletový kyslík metabolismus   MeSH
• transmisní elektronová mikroskopie MeSH
• Publikační typ
• časopisecké články MeSH

The aim of this study was to assess the phylogenetic relationships, ecology and ecophysiological characteristics of the dominant planktic algae in ice-covered lakes on James Ross Island (northeastern Antarctic Peninsula). Phylogenetic analyses of 18S rDNA together with analysis of ITS2 rDNA secondary structure and cell morphology revealed that the two strains belong to one species of the genus Monoraphidium (Chlorophyta, Sphaeropleales, Selenastraceae) that should be described as new in future. Immotile green algae are thus apparently capable to become the dominant primary producer in the extreme environment of Antarctic lakes with extensive ice-cover. The strains grew in a wide temperature range, but the growth was inhibited at temperatures above 20 °C, indicating their adaptation to low temperature. Preferences for low irradiances reflected the light conditions in their original habitat. Together with relatively high growth rates (0.4-0.5 day(-1)) and unprecedently high content of polyunsaturated fatty acids (PUFA, more than 70% of total fatty acids), it makes these isolates interesting candidates for biotechnological applications.

• MeSH
• biodiverzita * MeSH
• Chlorophyta klasifikace   genetika   metabolismus   MeSH
• fytoplankton klasifikace   genetika   izolace a purifikace   metabolismus   MeSH
• fyziologická adaptace MeSH
• jezera MeSH
• ledový příkrov * MeSH
• nenasycené mastné kyseliny metabolismus   MeSH
• RNA ribozomální 18S genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Antarktida MeSH

Publikace přibližuje problematiku poruch příjmu potravy široké veřejnosti, jak laické, tak odborné, rodičům, učitelům i samotným lidem trpícím mentální anorexií nebo bulimií.

• MeSH
• bulimia nervosa MeSH
• fyziologie výživy MeSH
• mentální anorexie MeSH
• poruchy příjmu potravy MeSH
• psychoterapie MeSH
• služby péče o duševní zdraví MeSH
• Publikační typ
• populární práce MeSH

• Konspekt
• Psychiatrie
• NLK Obory
• psychiatrie

Here, we report an effect of short acclimation to a wide span of temperatures on photosynthetic electron transfer, lipid and fatty acid composition in the snow alga Chlamydomonas cf. nivalis. The growth and oxygen evolution capacity were low at 2 °C yet progressively enhanced at 10 °C and were significantly higher at temperatures from 5 to 15 °C in comparison with the mesophilic control Chlamydomonas reinhardtii. In search of the molecular mechanisms responsible for the adaptation of photosynthesis to low temperatures, we have found unprecedented high rates of QA to QB electron transfer. The thermodynamics of the process revealed the existence of an increased structural flexibility that we explain with the amino acid changes in the D1 protein combined with the physico-chemical characteristics of the thylakoid membrane composed of > 80% negatively charged phosphatidylglycerol.

• MeSH
• chinony metabolismus   MeSH
• Chlamydomonas růst a vývoj   metabolismus   MeSH
• fotosyntéza * MeSH
• fotosystém II (proteinový komplex) chemie   metabolismus   MeSH
• fyziologická adaptace MeSH
• intracelulární membrány metabolismus   MeSH
• konzervovaná sekvence MeSH
• kyslík metabolismus   MeSH
• lipidy MeSH
• metabolismus lipidů MeSH
• molekulární sekvence - údaje MeSH
• nízká teplota MeSH
• sekvence aminokyselin MeSH
• teplota MeSH
• termodynamika MeSH
• transport elektronů MeSH
• tylakoidy metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The main analytical benefit of this study is the development of methods enabling a rapid determination of total lipids of algae by lipidomic analysis and detailed identification and quantification of a complex mixture of natural TAGs by silver-LC/APCI-MS and NARP-LC/APCI-MS. Both types of chromatography can readily identify, both qualitatively and semiquantitatively, triacylglycerols containing 16:3 and 16:4 acids in the molecule. We conclude that the genus Chloromonas is a major producer of C16 PUFAs mostly contained in TAGs. Since more detailed studies in this field have been stymied by the shortage of 16:3 and 16:4 FAs, we decided to study the alga Chloromonas as a potential biotechnological source of C16 PUFAs.

• MeSH
• chromatografie kapalinová metody   MeSH
• hmotnostní spektrometrie s elektrosprejovou ionizací metody   MeSH
• lipidy analýza   chemie   MeSH
• stříbro chemie   MeSH
• triglyceridy analýza   chemie   MeSH
• Volvocida chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• Klíčová slova
• bulimie, postoje,
• MeSH
• bulimia nervosa * diagnóza   etiologie   prevence a kontrola   psychologie   MeSH
• hodnotící studie jako téma MeSH
• lidé MeSH
• mentální anorexie * diagnóza   etiologie   prevence a kontrola   psychologie   MeSH
• mladiství MeSH
• poruchy příjmu potravy diagnóza   etiologie   klasifikace   prevence a kontrola   psychologie   MeSH
• sebepojetí MeSH
• statistika jako téma MeSH
• studenti psychologie   MeSH
• zdraví - znalosti, postoje, praxe * MeSH
• znalosti MeSH
• Check Tag
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH