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831.
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833.
The spores ofBacillus cereus can be germinated in reasonable synchrony in rich media. The survival of germinating cells after UV irradiation is strongly
affected by repair. When plating on mineral agar a linear decrease of survival is obtained between 20–60 min of germination,
whereas the survival on nutrient agar shows only minor fluctuations. The difference in survival on these two media which reached
1–2 orders of magnitude is due mostly to the shape of the shoulder on the survival curve. Survival on mineral agar may be
increased by postincubation in complex media or by preincubation in mineral media. It was concluded that repression and derepression
of biosynthetic pathways was responsible for the different efficiency of repair. 相似文献
834.
It was found that ethionine partially inhibits the transport of the inducer (TMG) of β-galactosidase into the cells ofEscherichia coli ML-30. The synthesis of β-galactosidase-specific messenger RNA is not inhibited. Ethionine appears to be incorporated into
proteins synthesized by the strains used. The incorporation of ethionine into the molecule of β-galactosidase results in the
synthesis of an enzymically inactive, immunologically cross-reacting protein. 相似文献
835.
836.
Polarization of tryptophan fluorescence in muscle 总被引:8,自引:0,他引:8
837.
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839.
The virus origin of a Czechoslovak isolate of potato witches' broom disease is discounted: electron micrographs of ultrathin section of phloem tissues from plants infected with potato witches' broom disease demonstratedMycoplasma-like bodies, spherical or elongated showing binary fission and fragmentation. The minute corpuscles have a diameter of about 50–60 nm, the largest bodies of 1000 nm. The width of elongated filamentous structures is about 200 nm, most oval bodies have a diameter of 250 nm. A weak tetracycline treatment of diseased plants causes a delay of symptom development; a strong dose of tetracycline (applied by means of the wick method into the stem) inhibits symptom appearance completely. Tetracycline produces a phytotoxic effect inhibiting the growth of tomato plants and causing (at higher concentrations) necrosis and death of these plants. There is a note in the paper dealing with the term “mycoplasma”. The word mycoplasma in the sense ofEriksson (1897) or ofMereschkowsky (1910) does not correspond to the genus nameMycoplasma Nowak (1929). 相似文献
840.