Purification and Characterization of the (alpha)-Glucuronidase from Thermoanaerobacterium sp. Strain JW/SL-YS485, an Important Enzyme for the Utilization of Substituted Xylans

A cell-associated (alpha)-glucuronidase was purified to gel electrophoretic homogeneity from the thermophilic anaerobic bacterium Thermoanaerobacterium sp. strain JW/SL-YS485. This enzyme had a pI of 4.65, a molecular weight of 130,000, and two subunits; the molecular weight of each subunit was 74,000. The enzyme exhibited the highest level of activity at pH 5.4 and 60(deg)C, as determined by a 5-min assay. The K(infm) and k(infcat) values of the enzyme for 4-methylglucuronosyl xylobiose were 0.76 mM and 1,083 IU/(mu)mol, respectively. The Arrhenius energy was 26.4 kJ/mol. The specific activities of the enzyme with 4-O-methylglucuronosyl xylobiose, 4-O-methylglucuronosyl xylotriose, and 4-O-methylglucuronosyl xylotetraose were 8.4, 4.8, and 3.9 IU/mg, respectively. The purified (alpha)-glucuronidase and a (beta)-xylosidase purified from the same organism interacted synergistically to hydrolyze 4-methylglucuronosyl xylotetraose.     

Comparison of Pseudomonas fragi and Gluconobacter oxydans for production of xylonic acid from hemicellulose hydrolyzates

Summary Xylonic acid was produced efficiently from pure xylose by Pseudomonas fragi ATCC 4973 and Gluconobacter oxydans subsp. suboxydans ATCC 621. The yield from 10% xylose was in both cases over 95% of the theoretical. However, the sensitivities of the strains towards the major inhibitors found in hemicellulose hydrolyzates, ie. acetic acid, furfural and two lignin-derived compounds, varied. G. oxydans tolerated all these inhibitors better than P. fragi. In tests using steamed hemicellulose hydrolyzate, G. oxydans was able to utilize the substrate only at dilute xylose concentrations. After ether extraction or mixed bed resin pretreatment, the fermentability of the hydrolyzate was increased significantly.     

Zum einfluß von niederschlägen auf pollen in der atmosphäre

Pollenkonzentrationsmessungen wurden mit handelsüblichen volumetrischen Pollenfallen in 1,8 und 18 m über Grund an demselben Standort durchgeführt. Das Ziel der Messungen lag in der Untersuchung der möglichen Beeinflussung des Pollenfluges während verschiedener Niederschlagsereignisse.

Die Pollenfallen waren auf dem Meßfeld des Wetteramtes Essen (Deutscher Wetterdienst) aufgestellt. Die Messung des Pollenfluges erfolgte in stündlichen Abständen in den Saisons von 1988 und 1989. Die Daten wurden mit den Ergebnissen eines Regenschreibers an demselben Standort korreliert. Daneben wurden 1988 bei ausgewählten Regenereignissen Regenproben aufgefangen und ihr Pollengehalt untersucht.

Mit beginnendem Niederschlagsbeginn konnte häufig ein schlagartiger Anstieg der Pollenregistrierung der Fallen in Bodennähe festgestellt werden. Analysen von Regentropfen in demselben Zeitraum zeigten dagegen nur einen geringen Pollengehalt. Die Erklärung für diesen Effekt liegt in vertikalen Luftströmungen, die bei Regenbeginn die Pollenkörner turbulent zwischen den Regentropfen aus höheren Luftschichten zur Erde herunterdrücken. Das turbulente Herabdrücken während des Regenschauers ist auch nach Ferntransport möglich.

Weiterhin ist ein Anstieg von Pollenkonzentration in Bodennähe durch die Wirkung von Regentropfen möglich, die die Blüten direkt treffen und damit Pollen aus den Stamina heraussschlagen.

Aus diesen Beobachtungen ist zu folgern, daß sich ein Pollenallergiker während eines Niederschlagsbeginns in einem geschlossenen Raum aufhalten sollte, da aus dem Regenbeginn eine Akkumulation von Pollen in Bodennähe resultieren kann.

Pollen data from two volumetric samplers, located at heights of 1,8 and 18 m above the ground, were used to investigate the influence of rainfall on pollen incidence. The counts were made by means of hourly analysis of the pollen concentration in the pollen season 1988 and 1989. These data were correlated with the data of a rain gauge. The traps were located in Essen in the lower Rhine area at the measurement field of the regional weather bureau of the German Weather Service. Rain samples were analysed for their pollen concentration at the same place in 1988. Besides this rain droplets were analyzed for the pollen content.

With the begin of rainfall the pollen concentration can increase explosively near the ground layer. Rain samples do not contain pollen whereas pollen traps indicate a high air concentration of pollen. The explanation for this effect is seen in air currents which force airborne pollen between the rain droplets turbulent down to the earth after they were dispersed by air convection in higher levels. The turbulent transport of pollen down to the ground can also be observed after long distance transport with rain.

A second observed effect of the begin of rainfall which can explosivly increase the pollen concentration near the ground is the pollen emission caused by the hit of the rain droplets on to the stamina of flowers, which are ready for pollen emission. This effect was only observed with the ground trap, whereas the high level trap did not register similar pollen concentrations.

As a result pollinosis patients are affected by these two impacts and should avoid to go outdoor in beginning rainfall and should close their windows immediately.     

Pollenemission und pollenflug von kräuterpollen

Die anemogamen Sommerkräuter Artemisia, Rumex und Plantago sind die Kräuter mit der höchsten allergologischen Bedeutung. Der Pollenflug dieser Pflanzen wurde in zwei verschiedenen Höhen über.Grund (Essen, 1,8 m und 18 m) an demselben Standort durch stündliche Pollenmessungen in den Saisons von 1988 und 1989 untersucht. Die Pollenfreisetzung von Artemisia vulgaris und des Rumex conglomeratus-Typs (R. acetosella, R. conglomeratus, R. longifolius, R. sanguineus) wird durch deutliche Tagesgänge charakterisiert, bei denen ein morgendlicher Freisetzungsgipfel typisch ist. Die zeitliche Verschiebung und die quantitativen Unterschiede des Tagesganges der Artemisia-Pollen bei bodenfernen und bodennahen Pollenfallen wird durch den Tagesgang der Luftkonvektion beeinflußt, die der wichtigste Faktor für den Vertikaltransport von Pollen ist. Mit dem Sonnenaufgang beginnt ganz allmäblich die Erwärmung des Bodens und es entsteht Thermik (Luftkonvektion) — erst bodennah und dann von Stunde zu Stunde in höhere Schichten hinaufreichend. Daraus folgt, daß eine bodennahe Falle früher die Artemisia-Pollenemission dokumentiert als eine bodenferne Falle und auch quantitativ die bodennahe Falle höhere Beifußkonzentrationen wiedergibt. Dieses gilt auch für den Rumex conglomeratus-Typ, dessen hohes Gewicht zusätzlich einen schlechten Vertikaltransport bedingt.

Die Pollenemission von Plantago lanceolata und Rumex acetosa ist durch keinen typischen Tagesgang ausgezeichnet. Beide Pollentypen können leichter in höhere Luftschichten transportiert werden, weil ihre Pollenkörner nicht in den thermisch ungünstigen Morgenstunden freigesetzt werden. Daher sind in einer bodennahen und einer bodenfernen Falle nahezu identische Pollenkonzentrationen dieser Typen feststellbar.

The wind pollinated summer weeds Artemisia, Rumex and Plantago are the most important weed pollen of allergologie relevance. The pollen flight of these weeds at two different levels (Essen 1,8 m and 18 m above ground) was investigated by hourly pollen analysis during the seasons 1988 and 1989.

The emission of Artemisia vulgaris and Rumex conglomeratus-type pollen (R. acetosella, R. conglomeratus, R. longifolius, R. sanguineus) is characterized by a distinct diurnal pattern with a prominent mid-morning peak.

The phase shift and the quantitative differences for Artemisia pollen registration in a pollen trap at high level is influenced by the daily variation of air convection, which is the most important vertical transport factor for pollen. After sunrise, the ground warms up gradually and the result is the so called thermal current, at first at ground level and in time to higher layers. As a result the ground-level traps register Artemisia pollen earlier and also in greater quantities than those at roof level. This holds also true for the pollen of the Rumex conglomeratus-type.

The pollen emission of Plantago lanceolata and Rumex acetosa can be observed during the whole day. Pollen of these two species can be lifted up easier to higher atmospheric levels than those of Artemisia vulgaris and R. conglomeratus-type because they show a lower gravity and do not emit pollen under unfavorable convection conditions in the morning. Thus, in the same daily variation, a high- and a low-level trap register the same amount of emitted pollen of R. acetosa and P. lanceolata.     

A New Entodiniomorphid Ciliate,Troglocorys cava n. g., n. sp., from the Wild Eastern Chimpanzee (Pan troglodytes schweinfurthii) from Uganda

ABSTRACT. Troglocorys cava n. g., n. sp. is described from the feces of wild eastern chimpanzee, Pan troglodytes schweinfurthii, in Uganda. This new species has a spherical body with a frontal lobe, a long vestibulum, a cytoproct located at the posterior dorsal side of the body, an ovoid macronucleus, a contractile vacuole near the cytoproct, and a large concavity on the left surface of the body. Buccal ciliature is non‐retractable and consists of three ciliary zones: an adoral zone surrounding the vestibular opening, a dorso‐adoral zone extending transversely at the basis of the frontal lobe, and a vestibular zone longitudinally extending in a gently spiral curve to line the surface of the vestibulum. Two non‐retractable somatic ciliary zones comprise arches over the body surface: a short dorsal ciliary arch extending transversely at the basis of the frontal lobe and a wide C‐shaped left ciliary arch in the left concavity. Because of the presence of three ciliary zones in the non‐retractable buccal ciliature, the present genus might be a member of the family Blepharocorythidae, but the large left concavity and the C‐shaped left ciliary arch are unique, such structures have never been described from other blepharocorythids.     

The hydrolysis of steamed birchwood hemicellulose by enzymes produced byTrichoderma reesei andAspergillus awamori

Summary The hemicellulase separated from birchwood by steaming and water extraction comprised mainly of acetyl- and 4-O-methyglucurono-substituted xylo-oligomers. The liberation of the acidic side groups affected the rate and yield of the enzymatic hydrolysis of the xylo-oligomers. The hemicellulase ofTrichoderma reesei was superior to that ofAspergillus awamori both with respect to side group cleavage and xylose yield in hydrolysis.     

Heterologous expression and characterization of a novel branching enzyme from the thermoalkaliphilic anaerobic bacterium Anaerobranca gottschalkii

The gene encoding the branching enzyme (BE) from the thermoalkaliphilic, anaerobic bacterium Anaerobranca gottschalkii was fused with a twin arginine translocation protein secretory-pathway-dependent signal sequence from Escherichia coli and expressed in Staphylococcus carnosus. The secreted BE was purified using hydrophobic interaction and gel filtration chromatography. The monomeric enzyme (72 kDa) shows maximal activity at 50°C and pH 7.0. With amylose the BE displays high transglycosylation and extremely low hydrolytic activity. The conversion of amylose and linear dextrins was analysed by applying high-performance anion exchange chromatography and quantitative size-exclusion chromatography. Amylose (10⁴–4×10⁷ g/mol) was converted to a major extent to products displaying molecular masses of 10⁴–4×10⁵ g/mol, indicating that the enzyme could be applicable for the production of starch or dextrins with narrow molecular mass distributions. The majority of the transferred oligosaccharides, determined after enzymatic hydrolysis of the newly synthesized α-1,6 linkages, ranged between 10³ and 10⁴ g/mol, which corresponds to a degree of polymerisation (DP) of 6–60. The minimal donor chain length is DP 16. Furthermore, the obtained results support the hypotheses of a random endocleavage mechanism of BE and the occurrence of interchain branching.     

The utilization of renewable resources in German industrial production

Renewable resources will be an increasingly important issue for the chemical industry in the future. In the context of white biotechnology, they represent the intersection point of agriculture and the chemical industry. The scarcity and related increase in the price of fossil resources make renewable resources an interesting alternative. If one considers the production of bulk chemicals, it is evident that for this area besides the C sources, sugar and starch, new sources of raw materials must be opened up. One possible solution is to utilize lignocellulose both for materials and energy. This article discusses this interesting prospective for the future, particularly from the point of view of the German industry.     

Reproducibility of Frankfort Horizontal Plane on 3D Multi-Planar Reconstructed MR Images

Objective

The purpose of this study was to determine the accuracy and reliability of Frankfort horizontal plane identification using displays of multi-planar reconstructed MRI images, and propose it as a sufficiently stable and standardized reference plane for craniofacial structures.

Materials and Methods

MRI images of 43 subjects were obtained from the longitudinal population based cohort study SHIP-2 using a T1-weighted 3D sequence. Five examiners independently identified the three landmarks that form FH plane. Intra-examiner reproducibility and inter-examiner reliability, correlation coefficients (ICC), coefficient of variability and Bland-Altman plots were obtained for all landmarks coordinates to assess reproducibility. Intra-examiner reproducibility and inter-examiner reliability in terms of location and plane angulation were also assessed.

Results

Intra- and inter-examiner reliabilities for X, Y and Z coordinates of all three landmarks were excellent with ICC values ranging from 0.914 to 0.998. Differences among examiners were more in X and Z than in Y dimensions. The Bland–Altman analysis demonstrated excellent intra- as well as inter-examiner agreement between examiners in all coordinates for all landmarks. Intra-examiner reproducibility and inter-examiner reliability of the three landmarks in terms of distance showed mean differences between 1.3 to 2.9 mm, Mean differences in plane angulation were between 1.0° to 1.5° among examiners.

Conclusion

This study revealed excellent intra-examiner reproducibility and inter-examiner reliability of Frankfort Horizontal plane through 3D landmark identification in MRI. Sufficiently stable landmark-based reference plane could be used for different treatments and studies.