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991.
Evidence for a correlation between a slow component of delayed light emission and thermoluminescence from photosynthetic membranes is presented. It was observed that the intensity of delayed light measured 2.5 s subsequent to illumination at different temperatures when plotted as a function of temperature reproduces the glow curve pattern. The slow component of delayed light emission is also quantitatively related to the yield of thermoluminescence, the sum of the two remaining constant. 相似文献
992.
Asparagine was a superior nitrogen source for clavine-alkaloid production in Claviceps purpurea. Its transport into the cell excedded the cell's biosynthetic need for this amino acid. Asparagine entered the cell without degradation. This disturbed the relative pool sizes of various amino acids resulting in a change in the genetically determined ratio at which amino acids were utilized for protein synthesis. Overproduction of alkaloids (4500 mug.ml-1) may be associated with increased availability of tryptophan because of the enhanced assimilation of asparagine-derived ammonia via glutamine synthetase (EC 6.3.1.2). However, ammonium salts in the fermentation broth led to a depression of the alkaloid yield. Partial replacement of the ammonium salt by aspartic acid elevated alkaloid production. 相似文献
993.
H. Dave C. Ramakrishna B. D. Bhatt J. D. Desai 《World journal of microbiology & biotechnology》1994,10(6):653-656
Slop oil, i.e. waste oil from a petrochemical complex, contains at least 240 hydrocarbon components, of which 54% are from C5 to C11 and the rest from C12 to C23. Of 22 isolated bacterial cultures that were able to degrade slop oil, seven could each degrade about 40% of the slop oil, and a mixture of all seven could degrade 50% in liquid medium. Bioaugmentation of soil contaminated with slop oil with the mixed bacterial culture gave up to 70% degradation of slop oil after 30 days. This compares with 40% degradation without bioaugmentation. Bioaugmentation led to a significant increase in counts of bacteria able to degrade slop oil. Wheat sown on bioaugmented soil germinated and grew better than on non-augmented soil and led to increased degradation of slop oil (up to 80%). This indicates the potential of mixed culture for bioremediation. 相似文献
994.
R. S. Jadhav N. V. Thaker A. Desai 《World journal of microbiology & biotechnology》1994,10(3):360-361
An iron-inefficient variety of peanut plant, when grown hydroponically with the catechol siderophore of Rhizobium (peanut isolate), showed increased growth and chlorophyll content compared with plants grown with Fe alone. The siderophore, when used in concentrations less than the concentrations of Fe, was still effective in grwoth promotion, indicating that it might function as a shuttle agent, solubilizing and supplying Fe to the plant. Similar results were also obtained with desferrioxamine B.The authors are with the Department of Microbiology and Biotechnology Centre, Faculty of Science, M.S. University of Baroda, Baroda-390 002, Gujarat, India. 相似文献
995.
Evolution can favor antagonistic epistasis 总被引:2,自引:2,他引:0
The accumulation of deleterious mutations plays a major role in evolution, and key to this are the interactions between their fitness effects, known as epistasis. Whether mutations tend to interact synergistically (with multiple mutations being more deleterious than would be expected from their individual fitness effects) or antagonistically is important for a variety of evolutionary questions, particularly the evolution of sex. Unfortunately, the experimental evidence on the prevalence and strength of epistasis is mixed and inconclusive. Here we study theoretically whether synergistic or antagonistic epistasis is likely to be favored by evolution and by how much. We find that in the presence of recombination, evolution favors less synergistic or more antagonistic epistasis whenever mutations that change the epistasis in this direction are possible. This is because evolution favors increased buffering against the effects of deleterious mutations. This suggests that we should not expect synergistic epistasis to be widespread in nature and hence that the mutational deterministic hypothesis for the advantage of sex may not apply widely. 相似文献
996.
Staines HM Alkhalil A Allen RJ De Jonge HR Derbyshire E Egée S Ginsburg H Hill DA Huber SM Kirk K Lang F Lisk G Oteng E Pillai AD Rayavara K Rouhani S Saliba KJ Shen C Solomon T Thomas SL Verloo P Desai SA 《International journal for parasitology》2007,37(5):475-482
The altered permeability characteristics of erythrocytes infected with malaria parasites have been a source of interest for over 30 years. Recent electrophysiological studies have provided strong evidence that these changes reflect transmembrane transport through ion channels in the host erythrocyte plasma membrane. However, conflicting results and differing interpretations of the data have led to confusion in this field. In an effort to unravel these issues, the groups involved recently came together for a week of discussion and experimentation. In this article, the various models for altered transport are reviewed, together with the areas of consensus in the field and those that require a better understanding. 相似文献
997.
Receptor for advanced glycation end products expression on T cells contributes to antigen-specific cellular expansion in vivo 总被引:1,自引:0,他引:1
Moser B Desai DD Downie MP Chen Y Yan SF Herold K Schmidt AM Clynes R 《Journal of immunology (Baltimore, Md. : 1950)》2007,179(12):8051-8058
Receptor for advanced glycation end products (RAGE) is an activation receptor triggered by inflammatory S100/calgranulins and high mobility group box-1 ligands. We have investigated the importance of RAGE on Ag priming of T cells in murine models in vivo. RAGE is inducibly up-regulated during T cell activation. Transfer of RAGE-deficient OT II T cells into OVA-immunized hosts resulted in reduced proliferative responses that were further diminished in RAGE-deficient recipients. Examination of RAGE-deficient dendritic cells did not reveal functional impairment in Ag presentation, maturation, or migratory capacities. However, RAGE-deficient T cells showed markedly impaired proliferative responses in vitro to nominal and alloantigens, in parallel with decreased production of IFN-gamma and IL-2. These data indicate that RAGE expressed on T cells is required for efficient priming of T cells and elucidate critical roles for RAGE engagement during cognate dendritic cell-T cell interactions. 相似文献
998.
Grinevich Dmitry O. Desai Jigar S. Stroup Kevin P. Duan Jiaqi Slabaugh Erin Doherty Colleen J. 《Plant molecular biology》2019,99(1-2):1-15
Plant Molecular Biology - Genome-wide association study of maize plant architecture using F1 populations can better dissect various genetic effects that can provide precise guidance for genetic... 相似文献
999.
Soluble amyloid-beta (Abeta) aggregates are suspected to play a major role in Alzheimer's disease. Zn2+ at a concentration of a few micromolar, which is too dilute to affect the precipitation equilibrium of Abeta, can destabilize these aggregates [Garai, K., Sengupta, P., Sahoo, B., and Maiti, S. (2006) Biochem. Biophys. Res. Commun. 345, 210-215]. Here we investigate the nature of these aggregates in the context of the precipitation pathway, the mechanism underlying their destabilization, and the biological consequences of this destabilization. We show that the larger soluble aggregates (size >10 nm) form only in supersaturated Abeta solutions, implying that they are intermediates in the pathway toward fibril formation. We also show that Zn2+ destabilizes these intermediates by accelerating their aggregation kinetics. The resulting change in the size distribution of the Abeta solution is sufficient to eliminate its toxicity to cultured mammalian neurons. Our results provide an explanation for the existing observations that Zn2+ at a concentration of a few micromolar significantly reduces Abeta toxicity. 相似文献
1000.
The aim of this study was to isolate microorganisms capable of decolourizing and degrading anaerobically treated distillery spent wash. A bacterial consortium DMC comprising of three bacterial cultures was selected on the basis of rapid effluent decolourization and degradation, which exhibited 67 +/- 2% decolourization within 24 h and 51 +/- 2% chemical oxygen demand reduction within 72 h when incubated at 37 degrees C under static condition in effluent supplemented with 0.5% glucose, 0.1% KH(2)PO(4), 0.05% KCl and 0.05% MgSO(4) x 7H(2)O. Addition of organic or inorganic nitrogen sources did not support decolourization. The cultures were identified as Pseudomonas aeruginosa PAO1, Stenotrophomonas maltophila and Proteus mirabilis by the 16S rDNA analysis. 相似文献