Volume 8, Issue 2

Downstream regulatory element antagonist modulator (DREAM) protein is a 31 kDa Ca2+-regulated transcriptional repressor. It functions as a silencer of the gene transcription. In low intracellular free Ca2+ concentration DREAM tightly binds to the downstream regulatory element (DRE) of gene promoter and impedes the transcription. In higher Ca2+ concentrations DREAM binds Ca2+ and disconnects from DRE of the gene promoter enabling transcription. We report that DREAM is expressed in different human tissues including the pancreas, where it is located in the islets of Langerhans. Location of DREAM in RIN-F5 cells in cultures is restricted to the nucleus and membranes and changes after increased Ca2+-levels. The proteins dissociate from dimmers to monomers and translocate out of the nucleus. The expression of DREAM in β-cells in the islets of Langerhans regulates the promoter activity of the insulin gene by directly interacting with the sequence located between +52 bp and +81 bp downstream of the transcriptional start site of the promoter. Our results provide evidence for the existence of DRE sequence in the insulin gene promoter. It is suggested that DREAM is a repressor of insulin gene transcription, whose effect is mediated by direct binding to DRE sequence.

Metabolic fluxes are a key parameter of metabolic pathways being closely related to the kinetic properties of enzymes and could be conditional on their sequence characteristics. This study examines possible relationships between the metabolic fluxes and the amino acid (AA) composition (AAC) for enzymes from the yeast Saccharomyces cerevisiae glycolysis pathway. Metabolic fluxes were quantified by the COPASI tool using the kinetic models of Hynne and Teusink at 25 mM, 50 mM, and 100 mM of external glucose or employing literature data for cognate kinetic or stoichiometric models. The enzyme sequences were taken from the UniProtKB, and the AAC computed by the ExPASy/ProtParam tool. Multiple linear regressions (89.07% < R2 adjusted < 91.82%; P<0.00001) were found between the values of metabolic fluxes and the selected sets of AA frequencies (5 to 7 for each model). Selected AA differed from the rest by their physicochemical and structural propensities, thus suggesting a distinctive contribution to the properties of enzymes, and hence the metabolic fluxes. The results provide evidence that metabolic fluxes of the yeast glycolysis pathway are closely related to the AAC of relevant enzymes and support the view that catalytic, binding and structural residues are interdependent to ensure the efficiency of biocatalysts.

A laboratory scale sequencing batch reactor (SBR), fed with synthetic wastewater containing a mixture of organic compounds, was operated for nearly six months. Despite maintaining the same operational conditions, a deterioration of enhanced biological phosphorus removal (EBPR) occurred after 40 days of SBR operation. The Prel/Cupt ratio decreased from 0.28 to 0.06 P-mol C-mol−1, and C requirements increased from 11 to 32 mg C h−1 g−1 of mixed liquor suspended solids. A FISH analysis showed that the percentage of Accumulibacter in an overall community of polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) dropped from 93% to 13%. An increase in abundance of Gammaproteobacteria (from 2.6% to 22%) and Alphaproteobacteria (from 1.8% to 10%) was observed. The number of Competibacter increased from 0.5% to nearly 9%. Clusters 1 and 2 of Defluviicoccus-related GAOs, not detected before deterioration, constituted 35% and 27% of Alphaproteobacteria, respectively. We concluded that lab-scale experiments should not be extended implicitly to full-scale EBPR systems because some bacterial groups are detected mainlyin lab-scale reactors. Well-defined, lab-scale operational conditions reduce the number of ecological niches available to bacteria.

The Diptera community associated with fruit bodies of the wood-decaying fungus Meripilus giganteus (Pers.) P. Karst., 1882 was investigated in two city parks in Opava (Czech Republic, Central Europe) during the years 2009 and 2010. A total of 10,451 adult specimens of Diptera belonging to 66 species and 17 families emerged from this fungus during our rearing experiments. The six most dominant species, Coboldia fuscipes (Meigen, 1830) (D=50.70%), Drosophila funebris (Fabricius, 1787) (D=21.40%), Logima satchelli (Quate, 1955) (D =14.16%), Forcipomyia squamigera Kieffer, 1916 (D=5.48%), Lycoriella ingenua (Dufour, 1839) (D=2.96%) and Apteromyia claviventris (Strobl, 1909) (D=0.95%) represented 95.65% of all reared specimens. Altogether 59 species were reared from M. giganteus for the first time. Comments on host specialization, degree of synynthropy and other aspects of biology of particular species are provided. The qualitative composition of the fly community associated with M. giganteus in an urban habitat, causes of high species richness, and the predominance of polysaprophagous species in the reared material are discussed. The accidentally reared {itOrnitholeria nidicola} Frey, 1930 (Chiropteromyzidae) represents the first family record from the Czech Republic and the first record of the species from Central Europe.

Heavy metals are highly toxic to living organisms even in low concentrations owing to their cumulative effect. In this study the overall content of lead in herbal drugs was determined, as well as the content of lead which was released from tested drugs during the preparation of tea drinks. To determine the content of toxic lead, the highly sensitive microanalytical technique of the potentiometric stripping analysis (PSA) with oxygen as the oxidant was used. The lowest overall content of lead was detected for chamomile and ranged from 0.73 to 0.77 µg/g, while the greatest content of lead was determined in the samples of the frangula bark, and yielded approximately 3 µg/g. The lead content in the prepared tea drinks ranged from 0.26 to 1.23 µg/g and depended on the manner in which tea drink was prepared. All of the herbal drugs in this study contain a certain amount of the toxic metal lead, but at the same time, the contents were below the levels prescribed for this metal. The content of lead released from the herbal drug into the tea drink was three to five times lower than those of the overall content of this metal.

Verbascum species are widely used in folk medicine because of their broad range of biological activities. Harpagoside, an iridoid glycoside isolated from some Verbascum plants is known for its anti-inflammatory properties. In the present study, the effect of five extracts of Verbascum species and harpagosides were evaluated in mouse models of acute and chronic inflammation. The results demonstrate that Verbascum phoeniceum extract strongly inhibits COX-1 (60.2% inhibition vs PMA-stimulated cells) and COX-2 (44.8% inhibition) expression stimulated peritoneal macrophages resulting in reduced paw swelling in carrageenan-induced oedema (55.5% inhibition vs PBS-treated mice). Harpagoside ameliorated the development of zymosaninduced arthritis and reduced pathological changes in joints as shown by the decreased histological score for cell infiltration in synovial cavity (3.5±0.2 in vs 2.0±0.16), cartilage loss (2.5±0.3 vs 1.8±0.5) and bone resorption (2.4±0.2 vs 1.8±0.4). Molecular docking simulations of harpagoside suggest that it may function with increased specific affinity towards COX-1 than COX-2. The potential of harpagoside to be applied as an effective agent for treating joint-related disorders is discussed.

This study reports the first record of Coniochaeta on Laurocerasus officinalis Roem. from the Nitra district. This is the first record of Coniochaeta for Slovakia and also for Europe. The fungus Coniochaeta prunicola Damm & Crous (Coniochaetales, Sordariomycetes, Ascomycota) was isolated from damaged leaves and twigs of host trees. Morphological analyses demonstrate that Coniochaeta prunicola and Coniochaeta velutina are distinct species.

Microbial biofilms from surfaces in contact with water may play a beneficial role in drinking water treatment as biological filters. However, detrimental effects such as biofouling (i.e., biocorrosion and water quality deterioration) may also occur. In this study microbiological processes and factors influencing the activity of bacteria in biofilms were investigated by conventional cultivation methods. The presence of bacteria belonging to different ecophysiological groups was assessed during drinking water treatment, in biofilms developed on concrete, steel and sand surfaces. Influences of the treatment process, type of immersed material and physico-chemical characteristics of raw/bulk water and biofilms upon the dynamics of bacterial communities were evaluated. Results revealed intense microbial activity in biofilms occurring in the drinking water treatment plant of Cluj. Ammonification, iron reduction and manganese oxidation were found to be the predominant processes. Multiple significant correlations were established between the evolution of biofilm bacteria and the physico-chemical parameters of raw/ bulk water. The type of immersed material proved to have no significant influence upon the evolution of microbial communities, but the treatment stage, suggesting that the processes applied restrict microbial growth not only in bulk fluid but in biofilms, too.