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911.
Javier G. Fernández Velasco Norma L. Pucheu Oscar Romero Norma L. Kerber Raúl A. Fernández Augusto F. García 《Archives of microbiology》1985,143(2):192-195
The conditions under which an oscillatory behaviour is observed during net hydrolysis or synthesis of ATP in chromatophores of Rhodospirillum rubrum FR1 are described. In the case of ATPase the oscillations are observed at low temperature (ca. 11°C) in the dark after an initial transient behaviour. These oscillations are attenuated or disappear by the addition of an uncoupler.Oscillations are also observed during ATP synthesis. At 3°C the oscillations appear spontaneously if photophosphorylation is measured during a sufficiently long time. At 30°C the mere intercalation of a dark period also at 30°C is sufficient to trigger the oscillations in the following light period.Abbreviations Bchl
Bacteriochlorophyll
- FCCP
carbonyl cyanide p-trifluoromethoxyphenyl hydrazone
- PMS
phenazine methosulfate
- TMPD, N,N,N,N
tetramethyl-1,4-phenylenediamine
Dedicated to Prof. Dr. Gerhart Drews as a homage for his permanent example as hard worker and careful scientist and also for his remarkable human quality 相似文献
912.
Francisco Romero Francisco Javier Caballero Francisco Castillo José Manuel Roldán 《Archives of microbiology》1985,143(2):111-116
Anti-glutamine synthetase serum was raised in rabbits by injecting purified glutamine synthetase (GS) of the phototrophic bacterium Rhodopseudomonas capsulata E1F1. The antibodies were purified to monospecificity by immunoaffinity chromatography in GS-sepharose gel. These anti-GS antibodies were used to measure the antigen levels in crude extracts from bacteria, grown phototrophically with dinitrogen, nitrate, nitrite, ammonia, glutamate, glutamine or alanine as nitrogen sources. The amount of GS detected by rocket immunoelectrophoresis was proportional to Mn2+-dependent transferase activity measured in the crude extracts. Addition of GS inhibitor l-methionine-d,l-sulfoximine (MSX) to the actively growing cells promoted increased antigen levels, that were not found in the presence of glutamine or chloramphenicol. The ammonia-induced decrease in GS relative levels was reverted by MSX. GS levels remained constant when phototrophically growing cells were kept in the dark.Abbreviations GS
glutamine synthetase
- MOPS
2-(N-morpholine) propane sulfonate
- MSX
l-methionine-d,l-sulfoximine 相似文献
913.
Expression of the gene encoding protein A in Staphylococcus aureus and coagulase-negative staphylococci 总被引:13,自引:4,他引:9 下载免费PDF全文
Two shuttle vectors containing the gene for protein A (spa) from Staphylococcus aureus have been constructed to study expression of the gene in various strains of S. aureus and in the coagulase-negative species Staphylococcus epidermidis, Staphylococcus capitis, and Staphylococcus xylosus. One plasmid, pSPA15, contains the complete structural gene for protein A, which binds to the cell wall in various Staphylococcus species. The other plasmid, pSPA16, codes for a truncated protein A lacking the C-terminal part called region X. The latter is exclusively extracellular in all Staphylococcus species tested, which confirms the importance of region X for cell wall binding. The expression of the plasmid-coded protein A in various strains of S. aureus is strongly correlated to the expression of the chromosomal spa gene. The coagulase-negative species expressing plasmid-encoded protein A produce 12 to 30% of the amount coded by the chromosomal spa gene in S. aureus strains Cowan I and A676. 相似文献
914.
Formation of protoplasts and their reversion were followed in 7 strains of brevibacteria. The formation of protoplasts and
their reversion differed both between various species of brevibacteria and between various mutant strains of the same species. 相似文献
915.
Reversibility of the respiration-deficient locuspet23 and auxotrophic locuslys2 was followed in the standard (RAD1) and UV sensitive (rad1–2) strains ofSaccharomyces cerevisiae, both after identical doses of UV radiation and at identical survival. When comparing the reversibility after the treatment
with identical doses of UV radiation a much higher reversibility of both loci in strainrad1–2 could be detected. When comparing the reversibility of the loci in question at identical survival of both strains it could
be found that the reversibility of thepet23 locus is again much higher in strainrad1–2, whereas the reversibility of thelys2 locus is roughly identical in the two strains. Thus, the function of geneRAD1 in repair processes is apparently associated with the “error-free” repair, both at low and high doses of ultraviolet radiation. 相似文献
916.
A study was made on the phylogenetic relationships of species of the family Resedaceae, based on morphological features, chromosome meiotic behaviour, karyotype features, size and fertility of pollen grains, nucleotypic parameters, seed protein profiles and esterase isozyme patterns.For the comparison of the seed protein profiles among species a method was developed based on the presence or absence of the bands by means of a computer program. The dendrogram obtained by such a method is in line, to a great extent, with the clusters (sections) obtained within the family based on morphological features.Data on meiotic behaviour and on morphology, such as the type of fruit, carpel numbers and others, suggest that x=5 is the primitive basic chromosome number of this family. x1=6 and x2=7 are considered as secondary basic numbers derived from x=5 through aneuploid changes.The results support a proposed phylogenetic tree of the genera and sections of the genus Reseda represented in the European Flora.The principal phenomena that have operated in the evolution of the Resedaceae seem to be aneuploid changes, polyploidy and structural rearrangements. A trend towards DNA increase in the evolution of this group is also apparent. 相似文献
917.
Recombinant H-2 haplotype of mouse strain B10.D1(R108)/Y (symbol R108) obtained in experiments with skin grafting in the course of developing the CR B10.D1/Y strain (strain DBA/LacY--the donor of H-2q) was studied. Strains with recombinant H-2 haplotypes a, h2, g1, i3, i5, i7, m, y1 were used. Alleles of different H-2 (K, I, D) regions were determined according to the presence or absence of genetic complementation in the F1 test with skin grafts. R108 recombinant was studied by serological methods with panel of anti-H-2 sera. Anti-H-2Kb (H-2.33) and anti-H-2Dq (H-2.30) monospecific antisera were used in microcytotoxicity test and in absorption experiments in vitro. It was concluded that crossing over between H-2b and H-2q chromosomes, which led to formation of recombinant H-2 haplotype of R108 mice, occurred at I region, between IA and IC subregions. The H-2 complex of R108 line has KbIAbIJ?IE?ICqSqDq alleles. bq1 symbol was proposed for the H-2 haplotype of B10.D1(R108)/Y strain. 相似文献
918.
M. Kopecká 《Folia microbiologica》1984,29(6):441-449
The effect of papulacandin B on regenerating protoplasts ofSaccharomyces cerevisiae was studied by light and electron microscopy. In liquid media it inhibited the biogenesis of (1→3)-β-d-glucan fibrillar nets; as a result, the protoplasts did not grow polarly but only spherically. The effect was reversible.
Instead of the nets the inhibited protoplasts synthesized only individual microfibrils soluble in hydroxide; these were not
joined in the nets and were partially masked by amorphous material. The microfibrils disintegrated after lysis and did not
maintain the shape of protoplasts. Protoplasts inhibited in solid media grew spherically up to 25 μm but they did not divide
or revert or revert, in spite of forming cell walls. These walls were amorphous and fragile and they disintegrated during
preparation. Papulacandin B did not decrease the viability of protoplasts and did not interfere with their growth, biogenesis
of alkali-soluble glucan microfibrils or amorphous wall matrix. It inhibited specifically the synthesis of alkali-insoluble
branched (1→3)-β-d-glucan, a necessary building unit required for the formation of the fibrillar component of the cell wall responsible for
the cell wall shape, its rigidity and tensile strength. 相似文献
919.
The addition of 2–4% oils to the synthetic fermentation medium used for the cultivation ofStreptomyces cinnamonensis increased the production of monensin three times on the average. When the amount of the added oil was lower than 2% and higher
than 4% the production sharply decreased. The maximal production preceded the maximal consumption of individual fatty acids
of the added oils, the content of oleic acid decreasing most pronouncedly. 相似文献
920.
Glucose inhibits the inducible synthesis of β-D-glucosidase inStreptomyces granaticolor. Neither cAMP nor cGMP influence the inhibitory effect of glucose. Glucose also inhibits the inducible synthesis of the cellobiose
uptake system but has no effect on its activity. This may be the mechanism underlying glucose inhibition of induction of β-D-glucosidase inS.granaticolor. 相似文献