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An enrichment culture which converted acetate to methane at 60°C was obtained from a thermophilic anaerobic bioreactor. The predominant morphotype in the enrichment was a sheathed gas-vacuolated rod with marked resemblence to the mesophile Methanothrix soehngenii. This organism was isolated using vancomycin treatments and serial dilutions and was named Methanothrix sp. strain CALS-1. Strain CALS-1 grew as filaments typically 2–5 cells long, and cultures showed opalescent turbidity rather than macroscopic clumps. The cells were enclosed in a striated subunit-type sheath and there were distinct cross-walls between the cells, similar to M. soehngenii. The gas vesicles in cells were typically 70 nm in diameter and up to 0.5 m long, and were collapsed by pressures over 3 atm (ca. 300 kPa). Stationary-phase cells tended to have a higher vesicle content than did growing cells, and occasionally bands of cells were seen floating at the top of the liquid in stationary-phase cultures. Acetate was the only substrate of those tested which was used for methanogenesis by strain CALS-1, and acetate was decarboxylated by the aceticlastic reaction. The optimum temperature for growth of strain CALS-1 was near 60°C (doubling time=24–26 h), with no growth occurring at 70°C and 37°C. The optimum pH value for growth was near 6.5 in bicarbonate/CO2 buffered medium and no growth occurred at pH 5.5 or pH 8.4. No growth was obtained below pH 7 when the medium was buffered with 20 mM phosphate. Strain CALS-1 grew in a chemically defined medium and required biotin. Sulfide concentrations over 1 mM were inhibitory to the culture, and growth was more rapid with 1 mM 2-mercaptoethane sulfonate (coenzyme M) or 1 mM titanium citrate as an accessory reductant than with 1 mM cysteine. It is likely that strain CALS-1 represents a new species in the genus Methanothrix. 相似文献
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G. Albin Matson H. Eldon Sutton B. Etcheverry Raul Jane Swanson Abner Robinson 《American journal of physical anthropology》1967,27(2):157-193
This is the fourth paper in a series on the distribution of blood groups among Indians of South America. It reports the findings on the Indians of Chile and the Polynesians of Chile's Easter Island. Blood specimens were procured from the following putatively pure Indians and unmixed Polynesians: 44 Alacaluf of Puerto Eden, Isla Wellington, 141 Mapuche (Araucanian) of Lonquimay, Malleco Province, 80 Atacameños of Antofagasta Province, and 45 Polynesians of Easter Island. These 310 samples were tested for blood factors in the A-B-O, M-N-S-s, P, Rh-Hr, Lutheran, K-k, Lewis, Duffy, Kidd and Diego systems, and for the Wright (Wra) agglutinogen. Serum samples were tested for haptoglobins and transferrins. Hemolysates prepared from the blood clots were tested for hemoglobin types. The results are presented as phenotype incidences and calculated gene frequencies in appropriate tables. Locations of the populations from which blood samples were procured are shown on two maps. The high frequencies for the O gene usually reported for South American Indians obtain in putatively pure Chilean Indians but A1 is high in Easter Island Polynesians. In both Indians and Polynesians M, s, R1 (CDe), R2 (cDE), Lub, k, LeH, and Fya gene frequencies are high and B, N, S, Mia, Vw, Rº (cDe), r (cde), Lua, K, Le1, Fyb, and Wra (Ca) are low or absent. The Diego (Di) gene is present in the Mapuche and Atacameños but absent in the Alacaluf and Polynesians. Hp1 gene frequencies were determined only in the Alacaluf and Atacameños, in which they are 0.48 and 0.67 respectively. Transferrins were determined for the Alacaluf and Atacameños Indians and all were classified as Tf C. All Chilean Indian and Polynesian specimens were tested electrophoretically for hemoglobin types and all contained only hemoglobin (A) as a major component. 相似文献
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A replication-thermosensitive, pSC101-derived plasmid containing the int gene and RHS-2 from the integron in Tn21 and a kanamycin resistance marker has been constructed and used to obtain Tn21 integrase (Int21)-mediated plasmid integration in the Escherichia coli chromosome. Colonies carrying an integrated plasmid were obtained after growth at 42 degrees C. Southern hybridization and PCR experiments indicated that they contained the plasmid specifically integrated through the RHS into different positions in the E. coli chromosome. Nucleotide sequence determination of the plasmid-chromosome junctions showed that integration sites in the chromosome were pentanucleotides with the sequence described for Int21 secondary sites. 相似文献
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Anthony T.W. Cheung Richard B. Moss Geoffrey Kurland Albin B. Leong William J. Novick 《Journal of medical primatology》1993,22(4):257-262
We have recently established a rhesus monkey model of chronic Pseudomonas aeruginosa (PA) endobronchitis by bronchoscopic instillation of PA-embedded agar beads. All experimental animals developed chronic neutrophilic endobronchitis similar to chronic PA endobronchitis in cystic fibrosis (CF). Histopathologic studies further confirmed similarities to chronic PA endobronchitis in CF, including marked peribronchial inflammation, epithelial damage, presence of degraded cilia and ciliary abnormalities, appearance of PA bacterial clusters, mucosal hyperplasia, goblet cell hypertrophy/hypersecretion, airway obstruction, alveolar abnormalities, bronchiectasis, and fibrosis. 相似文献
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Michael Neubeck Elmar Prenner Predrag Horvat Rudolfo Bona Albin Hermetter Anton Moser 《Archives of microbiology》1993,160(2):101-107
The bacterial secretion of glutamate was studied through plasma membrane fluidity, measured by anisotropy using the fluorophore TMA-DPH incorporated in the lipid part of the cell membrane. Cells of Brevibacterium sp. ATCC 13869 (wild type) were switched from the biotin-limited, producing state to the biotin-supplemented, non-producing state, and back. The following conclusions could be drawn: 1. It was not possible to detect any change in anisotropy by switching the cells from biotin-limited biotin-supplemented, as well as from biotin-supplemented, to biotin-limited, media. 2. The anisotropy value in the glutamic acid fermentation remains constant during the lag, exponential, growth, production and stationary phases. 3. The treatment of cells with a neutral synthetic polyester of ethylene-and propyleneoxide with soya oil-fatty acids increased the anisotropy values, indicating incorporation of the surfactant. 4. Glutamate secretion is not coupled with membrane fluidity, so a leak providing a general fluidization of the membrane could not be detected. 相似文献
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