Search results for "Arabinose"
showing 10 items of 15 documents
Recombinant laccase from Pediococcus acidilactici CECT 5930 with ability to degrade tyramine
2017
Biogenic amines degradation by bacterial laccases is little known, so we have cloned and heterologously expressed, in E. coli, a new laccase from Pediococcus acidilactici CECT 5930 (Lpa5930), a lactic acid bacterium commonly found in foods able to degrade tyramine. The recombinant enzyme has been characterized by physical and biochemical assays. Here we report the optimization of expression and purification procedures of this laccase. DNA encoding sequence of laccase from P. acidilactici was amplified by PCR and cloned into the expression plasmid pET28a for induction by isopropyl-β-D-thiogalactoipyranoside. Protein expression was performed in E. coli BL21(DE3) harboring pGro7 plasmid expres…
Ethanol Production by Selected Intestinal Microorganisms and Lactic Acid Bacteria Growing under Different Nutritional Conditions
2016
To gain some specific insight into the roles microorganisms might play in non-alcoholic fatty liver disease (NAFLD), some intestinal and lactic acid bacteria and one yeast (Anaerostipes caccae, Bacteroides thetaiotaomicron, Bifidobacterium longum, Enterococcus fecalis, Escherichia coli, Lactobacillus acidophilus, Lactobacillus fermentum, Lactobacillus plantarum, Weissella confusa, Saccharomyces cerevisiae) were characterized by high performance liquid chromatography for production of ethanol when grown on different carbohydrates: hexoses (glucose and fructose), pentoses (arabinose and ribose), disaccharides (lactose and lactulose), and inulin. Highest amounts of ethanol were produced by S. …
Shell matrices of recent rhynchonelliform brachiopods: microstructures and glycosylation studies.
2007
ABSTRACTLike most metazoan biomineralisations, the brachiopod shell is the end product of a biologically controlled calcification process. The main agent of the control is the extracellular matrix, which is secreted by the outer mantle epithelium. This matrix mediates the calcification process by allowing crystal nucleation and elongation in specific orientations and finally, by stopping crystal growth. The proteinaceous moiety of brachiopod shell matrices has been extensively studied. Less known are the post-translational modifications that occur in these matrices, in particular glycosylations. In this comparison of five species of Recent articulated brachiopods, the ratio of soluble to in…
Water-Soluble Polysaccharides from Ephedra alata Stems: Structural Characterization, Functional Properties, and Antioxidant Activity
2020
In this study, the physicochemical characterization, functional properties, and antioxidant activity of polysaccharides extracted from Ephedra alata (EAP) were investigated. EAP were extracted in water during 3 h with a liquid/solid ratio of 5 in a water bath at 90 °
Photocatalytic formation of H2 and value-added chemicals in aqueous glucose (Pt)-TiO2 suspension
2016
Abstract Commercial and home prepared bare and Pt-supported TiO2 samples were used as the photocatalysts for the aqueous photo-conversion of glucose at ambient pressure and temperature. Aerobic and anaerobic conditions were used to study the products of glucose degradation both in the liquid (arabinose, erythrose, gluconic acid, glucaric acid, fructose and formic acid) and gaseous (H2 and CO2) phases. The distribution of these molecules was different in the presence of the various powders, depending on the structural and physico-chemical properties of the materials, and Pt resulted essential for the anaerobic production of H2. The home prepared samples resulted more active than the commerci…
Influence of nitrogen and carbon sources on the production of ochratoxin A by ochratoxigenic strains of Aspergillus spp. isolated from grapes.
2008
This work studies the influence of nitrogen and carbon source on ochratoxin A production by three Aspergillus isolates A. ochraceus (Aso2), A. carbonarius (Ac25) and A. tubingensis (Bo66), all isolated from grapes. A basal medium (0.01 g/l FeSO4.7H2O, 0.5 g/l MgSO4.7H2O, 0.5 g/l Na2HPO4.2H2O, 1.0 g/l KCl) was prepared. This medium was supplemented with different nitrogen sources, both inorganic [(NH4)3PO(4), 0.3 g/l plus NH4NO3, 0.2 g/l] and organic (histidine, proline, arginine, phenylalanine, tryptophan or tyrosine) at two concentrations (0.05 g/l or 0.3 g/l), and different carbon sources (sucrose, glucose, maltose, arabinose or fructose) at three concentrations (10 g/l, 50 g/l or 150 g/l…
Reaction pathways of glucose oxidation by ozone under acidic conditions.
2009
The ozonation of d-glucose-1-(13)C, 2-(13)C, and 6-(13)C was carried out at pH 2.5 in a semi-batch reactor at room temperature. The products present in the liquid phase were analyzed by GC-MS, HPAEC-PAD, and (13)C NMR spectroscopy. Common oxidation products of glucose have also been submitted to identical ozonation conditions. For the first time, a pentaric acid was identified and its formation quantitatively correlated to the loss of C-6 of glucose in the form of carbon dioxide. Potential mechanisms for the formation of this pentaric acid are discussed. The well-accepted pathway involving the anomeric position in glucose, gluconic acid, arabinose, and carbon dioxide is reinvestigated. The …
A novel galactose- and arabinose-specific lectin from the sponge Pellina semitubulosa: isolation, characterization and immunobiological properties.
1992
A new lectin from the sponge Pellina semitubulosa is derived which was extracted and purified to homogeneity. The purified lectin is probably a hexamer of polypeptide chains (each M(r) 34,000) which are covalently linked via disulfide linkages; the isoelectric point is 6.1. The lectin displays the following specificities: D-galactose (50% inhibition of hemagglutination at 0.2 mM) = L-arabinose (0.2 mM) greater than D-fucose (1.5 mM) greater than D-glucose (3.0 mM). It precipitates human erythrocytes (A1, A2, A1B, B, and O) with a titer between 2(8) and 2(11) and erythrocytes from sheep and rabbits with a titer between 2(5) and 2(10). The Pellina lectin displays a strong mitogenic effect on …