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101.
This report presents results in the composition of major carotenoids of various coloured mutants of the genusRhodotorula and of mating types of the genusRhodosporidium. The separation of carotenoid intermediates was carried out by thin layer chromatography using Silufol 254 Kavalier and the determination of eluated spots by spectrophotometry. There was found no difference in carotenoid composition of both mating typesa and α of individual species of the genusRhodosporidium. The vegetative and sexual reproduction ofRhodotorula andRhodosporidium can be separated from the carotenogenesis using 10?4 mol diphenylamine. It was concluded that lycopene could be the intermediate to mono- and dicyclic carotenoids; in the case of partial inhibition of the dehydrogenation step the direct cyclization of neurosporene to β-zeacarotene can be expected. An unknown compound, probably lycopersene was found and was considered to be the precursor of phytoene. Phytoene and phytofluene were proved in all studied samples. Nutritional conditions (vitamins, sulfur amino acids, etc.) are able to shift the ratios between major carotenoids. Rhodotorula aurantiaca strains were observed to be auxotrophic mutants of various characters and the existence of this species as independent one, was denied.  相似文献   
102.
103.
In der ArtVicia sepium L. kann man in Mitteleuropa und in südlichen Teilen von Nordeuropa drei Varietäten unterscheiden: 1. var.sepium mit breiten Blättchen und einem kahlen bis angedrückt behaarten Kelch, 2. var.montana Koch mit schmalen Blättchen und einem kahlen oder zerstreut angedrückt behaarten Kelch, und 3. var.eriocalyx ?elak. mit breiten bis mittelbreiten Blättchen und einem abstehend langbehaarten Kelch, noch mit einer niedrigen und einer hohen Wuchsform. Bei allen Proben wurde die Chromosomezahl 2n=14 festgestellt.  相似文献   
104.
Lotus krylovii Schischk. etSerg. undL. corniculatus L. subsp.frondosus Freyn sind zwei unterschiedliche Taxa, gekennzeichnet durch einige morphologische Merkmale.L. krylovii ist am nächsten mitL. tenuis Waldst. etKit. verwandt;L. corniculatus subsp.frondosus gehört in den Umkreis der Unterart vonL. corniculatus L., die im östlichen Teil des Areals der Art verbreitet ist. Nach ihrer Haupt-Verbreitung gehören die beiden Taxa zu den westasiatischen Arten.  相似文献   
105.
The authors submit a taxonomic evaluation of an intermediate group of strains between the speciesSaccharomyces carlsbergensis Hansen andSaccharomyces cerevisiae Hansen. The material consisted of atypical strains of “bottom” brewer’s yeasts and the synonymous strainsSaccharomyces monacensis Hansen andSaccharomyces mandshuricus Saito. It was found that there were two different serological types in the speciesSaccharomyces carlsbergensis, one of which was characterized by the presence of antigen “C” and was typical for this species, while the other possessed antigen “M” and was grouped roundSaccharomyces monacensis. This second serological type merges with a group of strains which gives only one third fermentation of raffinose, so that it is actually an intermediate betweenSaccharomyces cerevisiae Hansen andSaccharomyces carlsbergensis Hansen and indicates the course of progressive development from the former species to the latter. No close similarity was found betweenSaccharomyces mandshuricus Saito and some of the strains of the transitional group or typical representatives of the two main species, and the authors therefore consider that there is some obscurity as to its synonymity withSaccharomyces carlsbergensis.  相似文献   
106.
Chromosome numbers of the Czechoslovak species of the genusLotus, from various localities have been determined. The paper includes the speciesLotus uliginosus Schkuhr,L.tenuis Waldst. etKit. andL. borbásii Ujhelyi.  相似文献   
107.
Summary The influence of temperature on NO 3 - and NH 4 + uptake, and the activity of the assimilatory enzyme NO 3 - reductase (NR) was compared to inorganic C uptake (photosynthesis) in natural assemblages of Antarctic sea-ice microalgae. NO 3 - and NH 4 + uptake reached a maximum between 0.5°–2.0°C and 2.0°–3.0°C, respectively, which was close to that for photosynthesis (2.5°–3.0°C). NR showed a distinctly higher temperature maximum (10.0°–12.0°C) and a lower Q10 value than inorganic N and C transport. Our data imply that, owing to differential temperature characteristics between N transport and N assimilation at in situ temperature (-1.9°C), the incorporation of extracellular NO 3 - into cellular macromolecules, may be limited by transport of NO 3 - into the cell rather than the intracellular reduction of NO 3 - to NH 4 + . Despite differences in temperature maxima between N transport and N assimilation, the overall low temperature maxima of inorganic N metabolism characterizes Antarctic sea-ice microalgae as psychrophilic. Our study is the first to examine the temperature dependence of inorganic N uptake and assimilation in sea-ice microbial communities.  相似文献   
108.
Most anti-nicotinic acetylcholine receptor (AChR) antibodies in myasthenia gravis are directed against an immunodominant epitope or epitopes [main immunogenic region (MIR)] on the AChR alpha-subunit. Thirty-two synthetic peptides, corresponding to the complete Torpedo alpha-subunit sequence and to a segment of human muscle alpha-subunit, were used to map the epitopes for 11 monoclonal antibodies (mAbs) directed against the Torpedo and/or the human MIR and for a panel of anti-AChR mAbs directed against epitopes on the alpha-subunit other than the MIR. A main constituent loop of the MIR was localized within residues alpha 67-76. Residues 70 and 75, which are different in the Torpedo and human alpha-subunits, seem to be crucial in determining the binding profile for several mAbs whose binding to the peptides correlated very well with their binding pattern to native Torpedo and human AChRs. This strongly supports the identification of the peptide loop alpha 67-76 as the actual location of the MIR on the intact AChR molecule. Residues 75 and 76 were necessary for binding of some mAbs and irrelevant for others, in agreement with earlier suggestions that the MIR comprises overlapping epitopes. Structural predictions for the sequence segment alpha 67-76 indicate that this segment has a relatively high segmental mobility and a very strong turning potential centered around residues 68-71. The most stable structure predicted for this segment, in both the Torpedo and human alpha-subunits, is a hairpin loop, whose apex is a type I beta-turn and whose arms are beta-strands. This loop is highly hydrophilic, and its apex is negatively charged. All these structural properties have been proposed as characteristic of antibody binding sites. We also localized the epitopes for mAbs against non-MIR regions. Among these, the epitope for a monoclonal antibody (mAb 13) that noncompetitively inhibits channel function was localized within residues alpha 331-351.  相似文献   
109.
We previously observed that whenAzotobacter vinelandii was transformed by different broad-host-range plasmids, normal cellular functions such as growth and siderophore production are impaired. In the present work, whenA. vinelandii was transformed with the low copy number plasmid pRK290, the extent of this metabolic impairment was lessened, as evidenced by increased siderophore production and moderate levels of growth on medium that lacks added iron. It is concluded that the severity of the plasmid-induced metabolic load reflects the relative level of expression of plasmid-encoded proteins.  相似文献   
110.
Incubation of synaptosomes from rat brain with DL-2-amino-5-phosphonovalerate (APV) stimulated an increased release of dopamine, and this effect was strictly dependent on the extrasynaptosomal calcium level. APV increased biosynthesis of dopamine from tyrosine by 30%, whereas monoamine oxidase activity was inhibited by 30%. When synaptosomes were incubated with radioactive dopamine, APV caused a large decrease in incorporation of label into 3,4-dihydroxyphenylacetic acid but greatly increased incorporation into norepinephrine and its N-methyl derivatives. Quantification of dopamine and its metabolites in synaptosomes, using electrochemical detection, indicated that the presence of APV resulted in changes in the absolute levels of the aforementioned dopamine metabolites similar to the changes in radiolabel incorporation. Omission of Ca2+ from the extrasynaptosomal medium greatly diminished the APV-induced changes in catecholamine metabolism. The metabolic changes appear to largely result from an increased intrasynaptosomal Ca2+ level due to the APV-induced increase in calcium permeability of the plasma membrane.  相似文献   
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