Biomedical subjects

M Kantorová

Publications and source records attributed to M Kantorová.

6 recordsLinked to original sources

PubMed2005

Oligosaccharides produced by submerged cultures of Claviceps africana and Claviceps sorghi.

Oligosaccharides produced by submerged cultures of C. africana and C. sorghi were isolated by semipreparative HPLC. Structure of 6-O-beta-D-fructofuranosyl-D-glucopyranose (blastose), 1,6-bis-O-(beta-D-fructofuranosyl)-alpha-D-glucopyranoside (neokestose) and two sugar alcohols, 1-O-beta-D-fructofuranosyl-D-mannitol (fructosylmannitol) and 1,6-bis-O-(beta-D-fructofuranosyl)-D-mannitol (bisfructosylmannitol) was determined by NMR spectrometry. MALDI TOF MS analysis revealed molecular ions [M+Na]+ that indicate the presence of other tetra- and pentasaccharides (m/z = 689.4 and 851.5, respectively) and corresponding sugar alcohol (m/z = 691.4). Rapid conversion of sucrose into series of oligosaccharides and corresponding sugar alcohols was observed in all tested strains.

Chromatography, High Pressure Liquid↗

PubMed2004

Preparation of nanoparticles by electrocoagulation from soluble exopolysaccharide produced by Claviceps viridis.

Electrocoagulation is an evolving technology that has been effectively applied for wastewater treatment but its applications in biotechnology and nanotechnology are very limited. This method was applied for the preparation of nanoparticles from soluble exopolysaccharide (EPS) produced by Claviceps viridis in a submerged batch culture. A cathode/anode pair electrode (Al or Fe) system was used for determination of the separation rates of electrocoagulation and the yields of EPS nanoparticles production. The separation rates of 0.170 +/- 0.003 mg EPS/sec (Fe electrodes) and 0.250 +/- 0.003 mg EPS/sec (Al electrodes) were calculated for voltage gradient 1 V/1 cm of electrodes distance and were constant during experiments. The specific yield of EPS nanoparticles production based on the consumed electric power was dependent on the material of the electrodes and its value was determined as 0.71 +/- 0.01 mg EPS/W for Fe electrodes and 0.91 +/- 0.01 mg EPS/W for Al electrodes, respectively.

Chemical Precipitation↗

PubMed2004

Physiological dendrogram of Claviceps spp. based on sucrose metabolism in submerged cultures and its comparison with phylogenetic tree.

Sixteen isolates of Claviceps spp. were analyzed for the production of polysaccharides, oligosaccharides, and sucrose metabolism under conditions of submerged fermentation. Physiological markers calculated by the Verhulst-Pearl law were used for hierarchical cluster analysis. Low correlation was found between physiologically based dendrogram and phylogenetic analysis constructed from an alignment of rDNA sequences. To confirm the intraspecific uniformity of physiological markers three isolates of C. africana from different hosts and locations were included. The influence of genotype, physiological variability, environmental location and habitat on metabolite production is discussed.

Claviceps↗

PubMed2003

Biodegradable plastics from renewable sources.

Plastic waste disposal is a huge ecotechnological problem and one of the approaches to solving this problem is the development of biodegradable plastics. This review summarizes data on their use, biodegradability, commercial reliability and production from renewable resources. Some commercially successful biodegradable plastics are based on chemical synthesis (i.e. polyglycolic acid, polylactic acid, polycaprolactone, and polyvinyl alcohol). Others are products of microbial fermentations (i.e. polyesters and neutral polysaccharides) or are prepared from chemically modified natural products (e.g., starch, cellulose, chitin or soy protein).

Bacteria↗

PubMed2003

Kinetics of soluble glucan production by Claviceps viridis.

Among 18 tested strains of Claviceps spp., 7 produced significant amounts of exocellular polysaccharide (EPS). The maximum production of EPS was found in fermentation broth of Claviceps viridis. The kinetics of growth, substrate consumption, and EPS production in the batch, aerobic, submerged culture of this fungus were investigated in detail. The experimental data were processed by a simple mathematical model describing mass balance of growth, substrate consumption, formation of intermediates, and production of EPS. The parameters of the model were estimated from data obtained in cultivation performed in flasks and two laboratory fermentors of different size. Physiological similarity was obtained during process scale-up in volumetric ratio 1:100. The sugar consumption efficiency (52%) and observed EPS productivity (1.9 kg/m3 per d) were comparable with literature data.

Biomass↗

PubMed1999

Tumor necrosis factor alpha in various tissues of insulin-resistant obese Koletsky rats: relations to insulin receptor characteristics.

Tumor necrosis factor alpha (TNFalpha) was found to be significantly increased in skeletal muscles and retroperitoneal fat of obese insulin-resistant Koletsky rats as compared to control Wistar rats. This increase was accompanied by a depression of insulin receptor protein tyrosine kinase (PTK) activity. Neither the insulin-binding capacity nor insulin receptor affinity were related to this TNFalpha increase in these tissues. In the liver, no significant changes of TNFalpha content and only a lowering of insulin-binding capacity were found. It is concluded that an increased TNFalpha content in muscles and fat (but not in the liver) contributes to insulin resistance by lowering insulin receptor protein tyrosine kinase activity, while other insulin receptor characteristics (insulin-binding capacity and affinity of insulin receptors to the hormone) do not seem to be influenced by this factor.

Adipose Tissue↗