Einfluß von Montmorillonit auf die Bildung von Biomasse und Stoffwechselzwischenprodukten durch einige Mikroorganismen

Zusammenfassung Die Zugabe von Montmorillonit zu Kulturlösungen verschiedener Mikroorganismen ergab bei Schüttel- oder Standkulturen meist eine Steigerung der Biomasse und einen erhöhten Nährstoffverbaruch. Diese Steigerung wurde besonders unter aeroben Verhältnissen und in den ersten Wachstumsphasen beobachtet. Die Bildung von Äthanol durch S. cerevisiae bzw. Citronensäure durch A. niger war beschleunigt, aber nicht wesentlich erhöht. Manometrische Messungen mit S. cerevisiae ergaben in Abhängigkeit von der Montmorillonit-Konzentration einen höheren RQ. Die Relation der Biomasse zu verbrauchter Glucose deutet auf eine bessere Ausnutzung der Energiequelle für synthetische Prozesse hin.

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Influence of montmorillonite on the formation of biomass and metabolic products by some microorganisms

Summary The addition of montmorillonite to stationary and shake-cultures of various microorganisms usually increased total biomass formation and accelerated the utilization of nutrients. These effects were noted especially under aerobic conditions and during the initial growth phases. The formation of ethanol by S. cerevisiae and citric acid by A. niger was accelerated, but not significantly increased. manometric measurements with S. cerevisiae showed a higher RQ which increased with increasing montmorillonite concentrations. The relation between biomass formation and glucose consumption indicates a more efficient utilization of the energy source for synthetic processes.

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Abkürzung: Montmorillonit wird im Text als M bezeichnet.     

Morphological and Structural Properties of Cathode Compound Material for Lithium-Ion Battery

The combustion method for preparation of compound material like Li Co _0.5 Ni _0.45 Ag_0.05 O₂ cathodes is widely selected because it has the virtue of simplicity and lower cost. It was prepared by firing a mixture of stoichiometric amounts lithium nitrate (LiNO₃), cobalt nitrate (Co(NO₃)₂.6H₂O), nickel nitrate (Ni(NO₃)₂. 6H₂O) and silver nitrates (AgNO₃₎. The as-synthesized material was subjected to (TGA/DSC) analysis to determine the optimum range of annealing temperatures at 800, 900, and 1000 °C for 8 h. The effect of annealing on the structural and morphological features can be represented by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive scattering (EDS), and transmutation electric microscopy (TEM), powders data from this method showed the coexistence of cubic Li Ni₂O₄ spinel structures at 400 °C. The optimum annealing result at 900 °C with constant duration 8 hours showed a single rhombohedra layered type Li Co _0.5 Ni _0.45 Ag_0.05 O₂ and polycrystalline structures.     

In silico docking and molecular dynamics simulation of 3-dehydroquinate synthase (DHQS) from <Emphasis Type="Italic">Mycobacterium tuberculosis</Emphasis>

The shikimate pathway is as an attractive target because it is present in bacteria, algae, fungi, and plants but does not occur in mammals. In Mycobacterium tuberculosis (MTB), the shikimate pathway is integral to the biosynthesis of naphthoquinones, menaquinones, and mycobactin. In these study, novel inhibitors of 3-dehydroquinate synthase (DHQS), an enzyme that catalyzes the second step of the shikimate pathway in MTB, were determined. 12,165 compounds were selected from two public databases through virtual screening and molecular docking analysis using PyRx 8.0 and Autodock 4.2, respectively. A total of 18 compounds with the best binding energies (?13.23 to ?8.22 kcal/mol) were then selected and screened for absorption, distribution, metabolism, excretion, and toxicity (ADMET) analysis, and nine of those compounds were found to satisfy all of the ADME and toxicity criteria. Among those nine, the three compounds—ZINC633887?(binding energy =??10.29 kcal/mol), ZINC08983432?(?9.34 kcal/mol), and PubChem73393?(?8.61 kcal/mol)—with the best binding energies were further selected for molecular dynamics (MD) simulation analysis. The results of the 50-ns MD simulations showed that the two compounds ZINC633887 and PubChem73393 formed stable complexes with DHQS and that the structures of those two ligands remained largely unchanged at the ligand-binding site during the simulations. These two compounds identified through docking and MD simulation are potential candidates for the treatment of TB, and should undergo validation in vivo and in vitro.     

Bacterial decomposition of synthetic 14C-labeled lignin and lignin monomer derivatives.

Nocardia sp. which was isolated from soil is capable of degrading synthetic lignin and utilizing its monomer derivatives. Decomposition was monitored by measuring the 14CO2 evolved and O2 consumed, when the bacterium was grown on a medium containing specifically 14C-labeled ligning or monomer phenolic compounds as major carbon source. The time course of the 14CO2 release and O2 uptake indicates a significant depolymerization and utilization of lignin by the Nocardia sp.     

Biodegradation of C-labeled model and cornstalk lignins, phenols, model phenolase humic polymers, and fungal melanins as influenced by a readily available carbon source and soil

After 6 months of incubation in a fertile neutral sandy loam, about 48% of the ring carbons and 2-carbons and 60% of the OCH(3) carbons of specifically labeled coniferyl alcohol had evolved as CO(2). After 1 year, corresponding values were 55 and 65%. When coniferyl alcohol units were linked into model and cornstalk lignins, about 23% of the ring carbons and 2-carbons and 39% of the OCH(3) carbons had evolved as CO(2) after 6 months. After 1 year, corresponding values were about 28 and 46%. The addition of orange leaves (0.5%, wt/wt) after 6 months did not significantly increase the evolution of CO(2). Addition of orange leaves (0.5%, wt/wt) with specifically C-labeled pyrocatechol, coumaryl alcohol, model lignins, humic acid-type phenolic polymers and of uniformly C-labeled fungal melanins did not increase labeled C losses or C losses from the orange leaves. Decomposition of protein and pyrocatechol linked into model humic acid polymers, coniferyl alcohol C in model lignins, and Eurotium echinulatum melanin in six soils varied from 2 to 14%. Significant differences in C losses were related to soils and were not influenced by orange leaf applications.     

Treatment of atopic eczema in children: clinical trial of 10% sodium cromoglycate ointment.

In a double-blind randomised group-comparative trial 21 children with chronic atopic eczema were treated twice daily for up to 12 weeks with an ointment containing 10% sodium cromoglycate (SCG) in white soft paraffin. A similar group of 21 children was treated for up to 12 weeks with a placebo ointment consisting of the white soft-paraffin base only. The number of patients who withdrew from the trial because treatment was ineffective was significantly greater in the placebo group (16) than in the SCG group (four). Comparison between the two groups also showed significant improvement in inflammation, lichenification, and cracking and the symptoms of itching and sleep disturbance among those on SCG treatment. At the end of treatment significantly more patients in the SCG group (16) had benefited from treatment compared with only two patients in the placebo group. No patients experienced side effects. I conclude that SCG ointment may be a safe alternative to topical steroids in the treatment of atopic eczema in children.     

Comparison of long-term numerical and experimental total knee replacement wear during simulated gait loading

Pre-clinical experimental wear testing of total knee replacement (TKR) components is an invaluable tool for evaluating new implant designs and materials. However, wear testing can be a lengthy and expensive process, and hence parametric studies evaluating the effects of geometric, loading, or alignment perturbations may at times be cost-prohibitive. The objectives of this study were to develop an adaptive FE method capable of simulating wear of a polyethylene tibial insert and to compare predicted kinematics, weight loss due to wear, and wear depth contours to results from a force-controlled experimental knee simulator. Finite element-based computational wear predictions were performed to 5 million gait cycles using both force- and displacement-controlled inputs. The displacement-controlled inputs, by accurately matching the experimental tibiofemoral motion, provided an evaluation of the simple wear theory. The force-controlled inputs provided an evaluation of the overall numerical method by simultaneously predicting both kinematics and wear. Analysis of the predicted wear convergence behavior indicated that 10 iterations, each representing 500,000 gait cycles, were required to achieve numerical accuracy. Using a wear factor estimated from the literature, the predicted kinematics, polyethylene wear contours, and weight loss were in reasonable agreement with the experimental data, particularly for the stance phase of gait. Although further development of the simplified wear theory is important, the initial predictions are encouraging for future use in design phase implant evaluation. In contrast to the experimental testing which occurred over approximately 2 months, computational wear predictions required only 2h.     

Novel insight into the agonistic mechanism of alefacept in vivo: differentially expressed genes may serve as biomarkers of response in psoriasis patients

Alefacept is an LFA3-Ig fusion protein that binds to CD2 and is thought to inhibit T cell activation by antagonism of CD2 signaling or by lysis of CD2(+) cells. Alefacept is potential future therapeutic for organ transplant recipients or graft-vs-host disease and is an approved therapeutic for psoriasis vulgaris, which is a T cell-mediated inflammatory disease. However, alefacept improves psoriasis in only approximately 50% of patients treated for 12 wk. We studied the immunologic effects of alefacept in a group of psoriasis patients during treatment. We found that T cells, especially CD8(+) T cells, were rapidly decreased in the peripheral circulation. Decreases in circulating T cells were not associated with induced apoptosis. Unexpectedly, in addition to suppression of inflammatory genes, we found a marked induction of mRNAs for STAT1, IL-8, and monokine induced by IFN-gamma during the first day of treatment in PBMC. We confirmed the agonistic effects of alefacept in PBMC in vitro, which were similar to CD3/CD28 ligation on T cells. These data establish that alefacept activates gene expression programs in leukocytes and suggest that its therapeutic action may be as a mixed agonist/antagonist. Furthermore, responding patients to alefacept treatment show unique patterns of gene modulation. Whereas alefacept down-regulated TCRs CD3D and CD2 in responders, nonresponders reveal a higher expression of T cell activation genes such as CD69 in pretreatment PBMC. These finding suggest a potential basis for categorizing responders vs nonresponders at an early time point in treatment or before treatment of a broad range of proinflammatory diseases. This study 1) establishes alefacept as a novel CD2 agonist molecule for induction of leukocyte activation genes (prior work proposed its mechanism as a CD2 antagonist) and 2) that differential activation of genes may categorize clinical responders to this agent, critical for cost-effective use of this drug.