排序方式: 共有17条查询结果,搜索用时 15 毫秒
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Eshinimaev BTs Medvedkova KA Khmelenina VN Suzina NE Osipov GA Lysenko AM Trotsenko IuA 《Mikrobiologiia》2004,73(4):530-539
Two pure cultures of obligate methanotrophs, strains H-11 and 0-12, growing in the temperature range from 30 to 61 degrees C with an optimum at 55 degrees C were isolated from samples of silage and manure. Based on the results of analysis of the 16S rRNA genes, membrane-bound methane monooxygenase, and phenotypic properties, the isolates were assigned to the genus Methylocaldum. Significant temperature-dependent variations in morphology and phospholipid and fatty acid composition were revealed. Both strains assimilated methane carbon via the ribulose monophosphate, serine, and ribulose bisphosphate pathways. The activity of hexulose phosphate synthase was independent of the cultivation temperature; however, the activities of hydroxypyruvate reductase and ribulose bisphosphate carboxylase were higher in cells grown at 55 degrees C that in cells grown at 37 degrees C, indicating the important roles of the serine and ribulose bisphosphate pathways in the thermoadaptation of the strains under study. NH4+ assimilation occurred through reductive amination of alpha-ketoglutarate and via the glutamate cycle. The relationship between the physiological-biochemical peculiarities of the isolates and their thermophilic nature is discussed. 相似文献
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N A Ivanov E G Danilova N A Medvedkova A P Pekhov 《Biulleten' eksperimental'no? biologii i meditsiny》1983,96(8):78-80
Crude lysates from staphylococcal strains, containing DNA, were capable of transforming Bacillus subtilis at a rate of 1.68 X 10(-10) - 20.6 X 10(-10) depending on the marker according to which the transformers were selected. In a new host, plasmids showed the same behavior pattern as in the staphylococcus but their spontaneous loss was in all the cases recorded significantly more often. 相似文献
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Moderately thermophilic methanotrophs Methylocaldum szegediense O-12 and Methylococcus
capsulatus Bath exhibit activities of antioxidant protection enzymes: glutathione peroxidase, superoxide dismutase, and cytochrome c peroxidase. The cells of methanotrophs grown at optimal temperatures (57 or 45°C, respectively) produce reactive oxygen species
more actively than those grown at suboptimal temperatures, and exhibit higher activities of the membrane-associated cytochrome
c peroxidase. Glutathione, glutathione peroxidase, and glucose-6-phosphate dehydrogenase levels in Md. szegediense O-12 increased in response to lowering of the cultivation temperature. By contrast, glutathione accumulation in cells of
Mc. capsulatus Bath and the activity of glutathione peroxidase at a suboptimal temperature (29°C) were lower than at the optimal one. The
role of the multilevel system of antioxidant protection in the adaptation of methanotrophs to temperature fluctuations is
discussed. 相似文献
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A P Pekhov E V Shcherbakova N A Medvedkova K S Krivskaia 《Molekuliarnaia genetika, mikrobiologiia i virusologiia》1985,(3):19-22
A model of calculation of molecular weights of fragments EcoRI, Hind III and PvuI is formulated. A restriction site map of factor pAP39 is constructed automatically. Sites to EcoRI and PvuI are distributed in the segment with molecular weight 9.1 MD. 相似文献
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Thermophilic and thermotolerant aerobic methanotrophs 总被引:1,自引:1,他引:0
Yu. A. Trotsenko K. A. Medvedkova V. N. Khmelenina B. Ts. Eshinimayev 《Microbiology》2009,78(4):387-401
The review generalizes the modern data on the taxonomic, structural, and functional diversity of aerobic methanotrophs growing at 25–50°C (Methylococcus capsulatus), 30–62°C (Methylocaldum szegediense, Methylocaldum gracile, and Methylocaldum tepidum), and 50–65°C (Methylothermus thermalis), which belong mainly to the Gammaproteobacteria. The specific features of adaptation of these methanotrophs to the temperature influences are considered on the metabolic and genetic levels. The recent sensational reports on the discovery and primary characterization of thermoacidophilic methanotrophs of the phylum Verrucomicrobia surviving at extreme pH (1–2) and temperature (65°C) values, corresponding to extremely low levels of CH4 and O2 solubility, are analyzed. The possibilities of implementation of the biotechnological potential of thermophilic and thermotolerant methanotrophs are discussed. 相似文献
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