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961.
962.
Karl-Heinz Blotevogel Renate Gahl-Janßen Sigrid Jannsen Ulrich Fischer Frank Pilz Georg Auling A. J. L. Macario Brian J. Tindall 《Archives of microbiology》1991,157(1):54-59
A new mesophilic, irregular coccoid methanogen isolated from a river sediment is described. Hydrogen plus carbon dioxide or formate served as substrates for methanogenesis in a mineral salt medium. For growth acetate is strictly required. Elevated levels of sodium chloride were not required and were inhibitory at concentrations above 1.5% (w/v). The optimal growth temperature was at 45°C. The DNA base ratio was 48.6±1 mol% G+C. The polar lipid pattern and the polyamine content were similar to that found in several Methanoculleus species. The new isolate CB-1 was assigned as Methanoculleus oldenburgensis (DSM 6216). 相似文献
963.
Summary An obligate syntrophic culture was selected in mineral medium with phenol as the only carbon and energy source. The consortium consisted of a short and a long rod-shaped bacterium and of low numbers of Desulfovibrio cells, and grew only in syntrophy with methanogens, e. g. Methanospirillum hungatei. Under N2/CO2, phenol was degraded via benzoate to acetate, CH4 and CO2, while in the presence of H2/CO2 benzoate was formed, but not further degraded. When 4-hydroxybenzoate was fed to the mixed culture, it was decarboxylated to phenol prior to benzoate formation and subsequent ring cleavage. Isolation of pure cultures of the two rod-shaped bacteria failed. Microscopic observations during feeding of either 4-hydroxybenzoate, phenol or benzoate implied an obligate syntrophic interdependence of the two different rod-shaped bacteria and of the methanogen. The non-motile rods formed phenol from 4-hydroxybenzoate and benzoate from phenol, requiring an as yet unknown co-substrate or co-factor, probably cross-fed by the short, motile rod. The short, motile rodshaped bacterium grew only in syntrophy with methanogens and degraded benzoate to acetate, CO2 and methane. Desulfovibrio sp., present in low numbers, apparently could not contribute to the degradation of phenol or 4-hydroxybenzoate. 相似文献
964.
The effect of some gastroprotective agents cysteamine, sodium salicylate, atropine, cimetidine, and pyrido-pyrimidine derivatives, rimazolium, Ch-127 and a mast cell stabilizer, BMY-26517-31 was studied on the enhanced vascular permeability of gastric mucosa induced by 100% ethanol, on the enhanced vascular permeability of peritoneal blood vessels due to 0.3% acetic acid and on carrageenin edema test. We found that cysteamine, sodium salicylate, rimazolium and BMY-26517-31 inhibited the alcohol-induced enhanced vascular permeability. They also decreased the carrageenin-induced edema and--with the exception of BMY-26517-31--the acetic-acid-induced enhanced vascular permeability of the peritoneal vessels. These results suggest that similar events are present in the early phase of acute inflammation and chemically induced mucosal lesions. Consequently, antiinflammatory activity might play role in the protective mechanism of some anti-ulcer agents. 相似文献
965.
Volker Weimer und Karl-Heinz Schmidt 《Journal of Ornithology》1998,139(1):3-9
Zusammenfassung In zwei Untersuchungsgebieten mit unterschiedlichem geologischem Untergrund wird die Eiqualität bei der Kohlmeise im Hinblick auf die Gelegegröße, die Eigröße, die Eischalendicke sowie die damit verbundenen Masseverluste der Eier und die Schlüpfrate verglichen. In einem Muschelkalkgebiet mit einer besseren Ca-Versorgung lassen sich höhere Eivolumina, größere Eischalendicken und ein geringerer Masseverlust der Eier bei konstanter Temperatur feststellen als in einem Buntsandsteingebiet. Dies wirkte sich allerdings nicht auf die Schlüpfrate aus. Die Gelegegröße und die Schlüpfrate zeigen keine Unterschiede zwischen den Untersuchungsgebieten.
Studies on the egg quality of the Great Tit (Parus major) in relation to soil-condition
Summary Since the beginning of the 80's it has been evident that the immission of acidifying gases damages the ecosystem forest. The studies carried out since then mainly addressed the effects on invertebrates of aquatic ecosystems, on soils and vegetation.So far very few studies have been conducted which deal with the effects of acidification on indigenous forest birds. In the Netherlands, thin-shelled as well as porous eggs and a lower breeding success were found in areas with soil poor in calcium.In our study areas around Schlüchtern we also observed occasional eggs which had no eggshells at all or which dried out completely during hatching. These observations suggested a closer study of the effects of calcium availability on breeding biology.The favourable location of the Schlüchtern study areas between Spessart, Vogelsberg and Rhön with different geological formations provides good preconditions for establishing whether the various levels of calcium availability due to the different soil conditions affect the breeding biology of the Great Tit. In two study areas with different geological characteristics various aspects of egg quality in the Great Tit are compared: egg volume, eggshell thickness along with the loss of mass caused by evaporation, clutch-size and hatching rate. In a limestone area with a better calcium supply, the egg volume was larger, the shells were thicker and the mass loss of the eggs at constant temperature was smaller than in a sandstone area. Hatching rate was not affected. Clutch-sizes and hatching rates do not show any differences in the two study areas.相似文献
966.
Ferdinand Bohlmann Karl-Heinz Knoll Robert M. King Harold Robinson 《Phytochemistry》1979,18(12):1997-2002
While the roots of Ayapana amygdalina contain typical euparine derivatives, the aerial parts afforded in addition to known compounds two new α-santalene derivatives as well as twelve new labdane derivatives with a partly unusual oxidation pattern, two being norditerpenes. Furthermore, a new bisabolene isomer is present. The structures were elucidated by spectroscopic methods and a few chemical transformations. The chemotaxonomy is discussed briefly. 相似文献
967.
968.
Wolfgang Liebl Josef Gabelsberger Karl-Heinz Schleifer 《Molecular genetics and genomics : MGG》1994,242(1):111-115
The primary structure of the bglA gene region encoding a β-glucosidase of Thermotoga maritima strain MSB8 was determined. The bglA gene has the potential to code for a polypeptide of 446 amino acids with a predicted molecular mass of 51545 Da. The T, maritima β-glucosidase (BglA) was overexpressed in E. coli at a level comprising approximately 15–20% of soluble cellular protein. Based on its amino acid sequence, as deduced from the nucleotide sequence of the gene, BglA can be classified as a broad-specificity β-glucosidase and as a member of the β-glucosidase family BGA, in agreement with the results of enzymatic characterization of the recombinant protein. Comparative sequence analysis revealed distant amino acid sequence similarities between BGA family β-glucosidases, a β-xylosidase, β-1,4-glycanases of the enzyme family F (mostly xylanases), and other families of β-1,4-glycosyl hydrolases. This result indicates that BGA β-glucosidases may comprise one enzyme family within a large ‘enzyme order’ of retaining β-glycosyl hydrolases, and that the members of these enzyme groups may be inter-related at the level of active site architecture and perhaps even on the level of overall three-dimensional fold. 相似文献
969.
B J Knoll 《Journal of molecular biology》1979,132(3):551-555
Efficient lysogenization of Escherichia coli K12 by bacteriophage λ requires the high level of synthesis of the phage repressor shortly after infection. This high level of synthesis of repressor requires the action of the λ eII and cIII proteins. Certain mutants of λ (λcIIIs) appear to have excess activity and can lysogenize more efficiently than λ+. The basis for the enhanced lysogenization is that, while two or more infecting phage are necessary for λ+ to lysogenize, a single infecting λcIIIs particle is sufficient for lysogenization. Also, repressor levels in cells infected with λcIIIs are higher than in those infected with λ+. I report here that repressor overproduction by λcIIIs (1) is due to a much higher rate of repressor synthesis than that of λ+; (2) is most marked at low multiplicities of infection, possibly because λcIIIs produces repressor much more efficiently than λ+ as a singly infecting phage. 相似文献
970.
Intracellular proteases from sporulating Bacillus cereus have been purified by ammonium sulfate fractionation, heat treatment and DEAE cellulose column chromatography. After the last purification step, two protease activities, with an activity ratio of about thirty to one are resolved. Both proteases are resistant to o-phenanthroline but sensitive to phenyl methyl sulfonyl fluoride. Their separation by polyacrylamide gel electrophoresis and DEAE cellulose column chromatography, their difference in heat sensitivity and a mutation affecting only the major intracellular protease (IP1) suggest that the two are products of distinct genes. An IP1 mutant previously shown to produce coat defective spores (4) also turnsover protein with a reduced rate during late sporulation stages. Correlated with the slower turnover rate in this mutant is the more rapid disappearance of IP1. A partial revertant of this mutant has a protein turnover rate intermediate between that of the original mutant and wild type. These correlations imply that IP1 has an important role in protein turnover during sporulation. 相似文献