Biochemical characterization of lipopolysaccharides extracted from a hydrophobic strain of Pasteurella multocida

Lipopolysaccharides were extracted from freeze-dried cells of Pasteurella multocida strain P-1581 (serotype 8) by the phenol-chloroform-petroleum ether method and biochemically analysed using standard procedures. The primary neutral sugars were glucose, galactose and heptose. No deoxy sugars were detected. Amino sugars included galactosamine, glucosamine and glucosamine-6-phosphate. 3-Deoxy-d-manno-2-octulosonic acid was present at a relatively low concentration. The analyses included identification and quantification of phosphate and alanine. The primary fatty acids and their approximate relative ratios were 3-hydroxytetradecanoate and tetradecanoate 2:1. Tetradecanoic acid was bound almost exclusively by ester linkages. 3-Hydroxytetradecanoic acid was bound primarily by amide linkages, although significant numbers of ester-bound residues were noted. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis analyses indicated that the lipopolysaccharides were of low molecular weight.Abbreviations KDO 3-deoxy-d-manno-2-octulosonic acid - LPS lipopolysaccharide(s) - SDS-PAGE sodium dodecyl sulphate-polyacrylamide gel electrophoresis     

Application of the Faustmann principle to a short-rotation tree species: an analytical tool for economists,with reference to Kenya and leucaena

Attention has increasingly focussed on fast-growing trees as a potential means of slowing high rates of deforestation and as a source of renewable energy. Unfortunately, the analytical tools for determining economic tractability of tree-growing projects lags behind the popular support to implement them. This paper brings the methodology of the Faustmann Principle, which was established for use with longer growing species, to bear on leucaena, a short-rotation, leguminous tree crop. The principle incorporates biological and economic parameters to derive a function relating the present value of net revenue to rotation length. Additionally, a method of incorporating secondary benefits, such as nitrogen fixation, is demonstrated. Results from the model are applied to Kenya. Research on agro-climatic zones in Kenya is used to indicate the potential volume of leucaena production.     

Aufnahme und Umwandlung von 1-14C-Glycin und35S-Methionin sowie ihr Einbau in das Protein durch isolierte Erbsenwurzeln bei Kultur in vitro

Zusammenfassung Erbsenwurzeln wurden in Nährlösungen nach Bonner und Addicott mit Zusatz von 1-¹⁴C-Glycin oder³⁵S-Methionin kultiviert. Es wurde die Abnahme der Radioaktivität in der Nährlösung, die Radioaktivität der ausgeschiedenen CO₂-Menge, diejenige im pool der alkohollöslichen Substanzen und im Protein an aufeinanderfolgenden Kulturtagen bestimmt. 1-¹⁴C-Glycin beeinträchtigte in der beim Versuch benutzten Substanzmenge und der in ihr enthaltenen Radioaktivität das Wurzelwachstum nicht; jedoch wurde es durch die-Strahlung von³⁵S-Methionin bei einer Substanzmenge, die in inaktiver Form keine erkennbare Wachstumshemmung verursacht, gehemmt. Der CO₂-Partialdruck in den Kulturgefäßen beeinträchtigt das Wurzelwachstum nicht. Die Wurzeln nehmen beide Aminosäuren schnell aus den Lösungen auf, und zwar Glycin schneller als Methionin. Einen großen Teil der¹⁴C-Glycin-Radioaktivität scheiden die Wurzeln als¹⁴CO₂ wieder aus. Die Intensität der¹⁴CO₂-Bildung an aufeinanderfolgenden Tagen ändert sich in gleicher Weise wie die Radioaktivität des pool der löslichen Substanzen. Erbsenwurzeln bilden wie viele andere pflanzliche Gewebe aus 1-¹⁴C-Glycin hauptsächlich¹⁴C-Serin. Daneben wurde ein Teil der Radioaktivität aus dem 1-¹⁴C-Glycin auch in anderen Substanzen vorgefunden.³⁵S-Methionin oxydieren die Wurzeln, vielleicht durch physiologische Vorgänge, zu Methioninsulfon und Methioninsulfoxid. Aus den täglichen Änderungen der gemessenen Radioaktivität und der spezifischen Aktivität im pool der löslichen Substanzen und im Protein kann geschlossen werden, daß die Änderungen der Wachstumsintensität, welche die Wurzeln in den ersten Tagen nach der Isolierung vom Keimling erfahren, von Veränderungen der Intensität der Protein-Bildung oder des Protein-Stoffwechsels begleitet sind.

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Uptake and metabolism of 1-¹⁴C-glycine and³⁵S-methionine and their incorporation into protein by excised pea roots cultivated in vitro

Summary Excised roots of pea seedlings were cultivated in nutrient solution according to Bonner and Addicott additionally containing 1-¹⁴C-glycine or³⁵S-methionine, respectively. The diminution of radioactivity in the culture medium, the radioactivity of CO₂-output, that of the pool of ethanol-soluble substances and that of protein were estimated during subsequent days of culture. The growth of pea roots is not diminished by amount and radioactivity involved of glycine used in experiments. But it was inhibited by-radiation of such concentrations of³⁵S-methionine which does not markedly influence root growth in unlabelled state. Root growth is not affected by CO₂ partial pressure present in the culture flasks. Roots take up both amino acids rapidly, glycine more quickly than methionine. A great part of the¹⁴C-radioactivity of glycine roots do put out as¹⁴CO₂. The intensity of this output shows variations during subsequent days in the same manner as the radioactivity of the pool of soluble substances. From 1-¹⁴C-glycine pea roots synthesize mainly¹⁴C-serine as known from many other plant tissues. Besides some radioactivity originating from 1-¹⁴C-glycine is also found in other substances. Perhaps by physiological pathway pea roots oxidize methionine to methioninesulfone and methionine-sulfoxide. The daily variation of radioactivity and specific activity of the pool of soluble substances and of protein allow the conclusion that changes in growth intensity, which occur during the first days after isolation of roots from seedling, are accompanied by variations of intensity of protein synthesis or protein metabolism.

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1-¹⁴- ³⁵S- in vitro

1-¹⁴- ³⁵S-. : , CO₂, . ; , -, , . CO₂, , . , , . ¹⁴CO₂. ¹⁴CO₂ , . , , 1-¹⁴- ¹⁴-. . , , . , , , , .

     

Quantitative impact of CO2 enriched atmosphere on abundances of methanotrophic bacteria in a meadow soil

In the Giessen free-air CO₂ enrichment (GiFACE) experiment, 5 years of CO₂ enrichment led to decreased CH₄ uptake rates of the investigated meadow soil. In soils, CH₄ is mainly oxidised by methanotrophic bacteria. In the present study, abundances of methanotrophic bacteria and total bacteria in soil samples from the GiFACE experiment were quantified by applying pmoA- and 16S rRNA gene-targeted real-time PCR and fluorescence in situ hybridisation (FISH). Methanotrophic bacteria of the Methylosinus group (Alphaproteobacteria) and the Methylobacter/Methylosarcina group (Gammaproteobacteria) were detectable by real-time PCR as well as by FISH. Both quantitative analytical approaches revealed that abundances of either bacteria or methanotrophic bacteria in soil samples from sites under CO₂-enriched atmosphere were decreased. Compared to ambient site, only 46 and 30.5% of methanotrophic bacteria and 38 and 63.2% of total bacterial cell numbers could be detected under CO₂-enriched atmosphere by FISH and real-time PCR, respectively. These results suggest that significantly decreased abundances of methanotrophic bacteria could explain reduced CH₄ uptake rates.     

Temperature dependence of nitrification,denitrification, and turnover of nitric oxide in different soils

Summary The temperature dependence of the NO production rate and the NO consumption rate constant was measured in an Egyptian soil, a soil from the Bavarian Forest, and a soil from the Donau valley, together with the temperature dependence of the potential rates of ammonium oxidation, nitrite oxidation, and denitrification, and the temperature dependence of the growth of NH _inf4 ^sup+ -oxidizing, NO _inf2 ^sup- -oxidizing, and NO _inf3 ^sup- -reducing bacteria in most probable number assays. In the acidic Bavarian Forest soil, NO production was only stimulated by the addition of NO _inf3 ^sup- but not NH _inf4 ^sup+ . However, NO production showed no temperature optimum, indicating that it was due to chemical processes. Most probable numbers and potential activities of nitrifiers were very low. NO consumption, in contrast, showed a temperature optimum at 25°C, demonstrating that consumption and production of NO were regulated individually by the soil temperature. In the neutral, subtropical Egyptian soil, NO production was stimulated only by the addition of NH _inf4 ^sup+ but not NO _inf3 ^sup- . All activities and most probable numbers showed a temperature optimum at 25° or 30°C and exhibited apparent activation energies between 61 and 202 kJ mol^-1. However, a few nitrifiers and denitrifiers were also able to grow at 8° or 50°C. Similar temperature characteristics were observed in the Donau valley soil, although it originated from a temperate region. In this soil NO production was stimulated by the addition of NH _inf4 ^sup+ or of NO _inf3 ^sup- . Both NO production and consumption were stimulated by drying and rewetting.     

Bovine viral diarrhea virus in New World camelids.

A virus known to cause multiple problems in cattle, bovine viral diarrhea virus, was isolated from 3 different cases in New World camelids. Virus isolation, immunoperoxidase staining, and fluorescent antibody staining were used to detect the virus. The herds involved were screened for antibody titers to bovine viral diarrhea and virus isolation from the buffy coat. Bovine viral diarrhea virus should be considered as a cause of death in young and old New World camelids.     

Neospora-like encephalomyelitis in a calf: pathology, ultrastructure, and immunoreactivity

Protozoal encephalomyelitis was diagnosed in a 3-day-old calf that was stunted, weak, and recumbent. Grossly, the calf had contracted tendons in the forelegs, a slightly doomed skull, a porencephalic cyst in the cerebellum, ulcerative esophagitis, and abomasitis. Histologically, there was a multifocal nonsuppurative encephalomyelitis with clusters of protozoal tachyzoites and numerous protozoal cysts. The porencephalic cyst and gastrointestional lesions appeared to be unrelated to the protozoal infection and were suggestive of a concurrent bovine virus diarrhea infection. A few groups of protozoal tachyzoites and numerous tissue cysts were found in neuropile, particularily in neurons of the spinal cord. By light microscopy, smaller tissue cysts were found in the brain (majority from 14 to 20 microns) than in the spinal cord (majority from 20 to 48 microns). The cyst walls ranged in thickness from less than 1 micron to a maximum of 2 microns wide. Bradyzoites contained PAS-positive slender bradyzoites (5-8 x 1-2 microns). Tissue cysts reacted positively to anti-Neospora caninum sera; but unlike N. caninum, they were positive to 2 of 4 antisera against Toxoplasma gondii and to antisera to H. hammondi. Ultrastructurally, tissue cysts closely resembled a Neospora-like organism, including the finding of interneuronal protozoal cysts, thick cyst walls, a lack of micropores in the bradyzoites, and the presence of numerous micronemes oriented perpendicular to the pellicle. Ultrastructural features in the calf protozoan that have not been reported for N. caninum in dogs included the presence of numerous tubulovesicular structures in the cyst ground substance and bradyzoite vesicles that contained small vesicular structures and short, flat membrane segments.(ABSTRACT TRUNCATED AT 250 WORDS)