Процесс оценки уровня освоения профессиональных компетенций бакалавров на примере специальности «Землеустройство и кадастры»

В процессе исследования проводился анализ процесса формирования профессиональных компетенций бакалавров, разработка тестовых заданий для измерения профессиональных компетенций бакалавров, измерение профессиональных компетенций бакалавров. В результате исследования выявлены проблемы в процессе оценке уровня сформированности профессиональных компетенций бакалавров.In the course of the research, the analysis of the process of formation of professional competencies of bachelors was carried out, the development of test tasks to measure the professional competencies of bachelors, the measurement of professional competences of bachelors. As a result of the study, problems were identified in the process of assessing the level of formation of professional competencies of bachelors

Structure analysis of carboxymethyl starch by capillary electrophoresis and enzymic degradation

Carboxymethyl starches (CMS) with a degree of substitution (DS) in the range of 1.2 to 1.5 were analysed by capillary electrophoresis (CE) after hydrolysis and reductive amination in a borate buffer. The monomer composition determined was compared to data calculated by the statistical models of Spurlin and Reuben. In addition, the starch derivatives were exhaustively degraded by alpha-amylase and amyloglucosiclase and the amount of glucose liberated was determined. Results were discussed with regard to derivatisation conditions and properties of the carboxymethyl starches

Neue Charakterisierungsmethoden von Polysacchariden. Teilvorhaben: Methodenentwicklung zur Bestimmung der Substituentenverteilung von Cellulose-und Staerkederivaten Schlussbericht

SIGLEAvailable from TIB Hannover: F96B1646+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Galactan biosynthesis in snails: a comparative study of beta -(1 6) galactosyltransferases from Helix pomatia and Biomphalaria glabrata

Adult snails synthesize in their albumen glands a polysaccharide which is composed exclusively of D- or D- and L-galactose (Gal) residues which are interglycosidically linked by 1 → 3 and 1 → 6 bonds. It is the only carbohydrate source for embryos and freshly hatched snails. Two galactosyltransferases are described in this study which are most likely involved in the biosynthesis of this polysaccharide. One identified in Helix pomatia acts on oligosaccharides and could be used to synthesize a tetrasaccharide when the branched trisaccharide D-Gal-β-(1 → 3)-[D-Galβ-(1 → 6)]-D-Galβ-1 → OMe was offered as acceptor. This enzyme, requiring Mg++- and Mn++-ions for activity, introduced a linear β-(1 → 6) linkage at the terminal non-reducing ends and was not detected in Biomphalaria glabrata. The other enzyme, which introduced β-(1 → 6) linkages at subterminal D-Gal residues, thus forming branching points in the polysaccharide, was found in H. pomatia, Arianta arbustorum and B. glabrata with comparable activities. With the enzyme preparation of H. pomatia, up to four D-Gal residues were introduced into vicinal positions, forming single-membered side chains, if a hexasaccharide with five linearly β-(1 → 3)-linked D-Gal residues was offered as a acceptor. The multiple-branched structure formed is typical for snail galactans, making this enzyme a prime candidate for the branching enzyme in galactan synthesis. The enzyme activity could be solubilized and purified by affinity chromatography. In SDS-polyacrylamide electrophoresis, the Helix- derived eluate displayed two bands (68, 37 kDa) and that of Biomphalaria five bands (68, 63, 17.5; 15; 13 kDa). The purified material showed only 8% of the total activity of the crude extracts, but it could be shown that a phosphatase present in the crude extract can degrade UDP formed in the transfer reaction and thus drive the reaction to completion

New approaches to the analysis of enzymatically hydrolyzed methyl cellulose. Part 1. Investigation of the influence of structural parameters on the extent of degradation

Six methyl celluloses (MCs), one with a degree of substitution (DS) of 1.32 and five with DS between 1.83 and 1.88, were thoroughly investigated. Monomer composition and methyl distribution in the polymer chain were analyzed after total or partial random hydrolysis and appropriate derivatization with gas chromatography ( GC) and mass spectrometry (MS), respectively, and used as reference data. The same MCs were then hydrolyzed with an enzyme preparation of Trichoderma longibrachiatum and further investigated with size-exclusion chromatography with multiangle light scattering and refractive index detection (SEC-MALS/RI) and MS. Electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI) in combination with various MS analyzers were compared with respect to quantification of the degradation products directly and after perdeuteriomethylation. The methyl group distribution in the oligomeric fractions and the average DS as a function of chain length were calculated from ESI mass spectra. With help of the reference analysis, patterns could be corrected for the unspecific contribution of end groups. By labeling and ESI tandem MS, our knowledge about the tolerance of the enzymes' sub-sites with respect to the number of methyl groups could be improved

New approaches to the analysis of enzymatically hydrolyzed methyl cellulose. Part 2. Comparison of various enzyme preparations

In this part of our studies, dealing with new approaches to the analysis of enzymatically hydrolyzed methyl cellulose, five different enzymes or enzyme preparations containing endoglucanases (from Bacillus agaradhaerens Cel 5A, Trichoderma reesei, Trichoderma Viride, and two obtained from Trichoderma longibrachiatum) were used to hydrolyze six different methyl celluloses (MCs). The main goal was to investigate whether enzymes could be used for determination of the heterogeneity of the substituent distribution along the cellulose chain. To obtain information about the heterogeneity, it was necessary to gather information on how the enzymes affect hydrolysis. Size exclusion chromatography with multi-angle light scattering and refractive index detection (SEC-MALS/RI) was used to estimate the molar mass distribution of the MCs before and after hydrolysis. A novel internal standard addition method in combination with electrospray ionization ion trap mass spectrometry (ESI-ITMS) was used to determine the amount of formed oligomers. Two MCs, one with a degree of substitution (DS) of 1.8 and one with DS 1.3, were hydrolyzed with all of the five enzymes. The yield of summarized di- and trisaccharides was approximately 2% of the hydrolysis products for the MC with DS 1.8, whereas the product mixture, obtained from a MC with a DS of 1.3, contained 7-16% di- and trisaccharides. By a novel sample preparation method in combination with ESI-IT tandem MS, outlined in part 1 of this work, it was shown that the enzymes produced oligomers with the reducing end bearing no or only one substituent. Comparison of the methyl pattern at the nonreducing ends of the dimers and trimers indicated that the -2 subsite of the active complex is less tolerant than subsites -3 and +1. All enzymes had similar general selectivity toward the methyl substituents but also showed some differences. From both SEC-MALS/RI and ESI-ITMS, differences with respect to substituent distribution of MCs could be recognized but not for each enzyme used. Basic considerations for enzymatic hydrolysis and analysis of methyl cellulose were listed as a consequence of the results from the work

Hydrolysis of maltoheptaose in flow through silicon wafer microreactors containing immobilised alpha-amylase and glycoamylase

In this study,a silicon micro immobilised enzyme reactor (mu IMER) has been applied for hydrolysis of maltoheptaose as a model maltodextrin and starch using immobilised otamylase (from Aspergillus oryzae) and glycoamylase (from Aspergillus niger). The influence of several parameters was investigated such as immobilisation chemistry, buffer constituents, pH, temperature, flow rate and substrate concentration. The conversion efficiency profile of the substrate was measured and the long-term stability of the reactor was tested. For separation and detection of the formed hydrolysis products, high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) was used. The results show that the mu IMERs can also be used for hydrolysis of starch and also additionally be connected directly on-line with, e.g., liquid chromatography, making it possible to perform on-line characterisation and analysis of starch hydrolysis products