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91.
Decolorization of Fast red by metabolizing cells of <Emphasis Type="Italic">Oenococcus oeni</Emphasis> ML34 总被引:1,自引:1,他引:0
Amani M. D. El Ahwany 《World journal of microbiology & biotechnology》2008,24(8):1521-1527
Three different azo dyes such as Fast red, metanil yellow and Fast orange were examined for their decolorization by O. oeni ML34. Fast red (FR) was decolorized by 68%, whereas the other dyes were removed by only about 30%. The effects of glucose
addition, substrate (dye) concentration and environmental factors (temperature, pH) on decolorization were investigated by
two-level factorial design. The statistical analyses revealed that glucose specifically increases the extent of FR decolorization.
A glucose level of 5 g/l was the optimum concentration for removal of, FR reaching a decolorization percentage of up to 93%. 相似文献
92.
The plant membrane potential reports on the activity of electrogenic plasma membrane transport processes. The membrane potential is widely used to report for early events associated with changes in light regime, hormone action or pathogen attacks. The membrane potentials of guard cells can be precisely measured with microelectrodes, but this technique is not well suited for rapid screens with large sample numbers. To provide the basis for large-scale membrane potential recordings, we took advantage of voltage-sensitive dyes. Using the fluorescent dyes bis-(1,3-dibutylbarbituric acid)-trimethine oxonol (DiBAC(4)(3)) and the FLIPR Membrane Potential Assay Kit (FMP) dye we followed changes in the membrane potential in guard cells and vacuoles. Based on the fluorescence of DiBAC(4)(3) a method was established for quantification of the membrane potential in guard cell protoplasts which should be considered as an excellent system for high-throughput screening of plant cells. In the absence of abscisic acid (ABA), one-third of the guard cell protoplast population spontaneously oscillated for periods of 5-6 min. Upon application of ABA the hyperpolarized fraction ( approximately 50%) of the guard cell protoplast population depolarized within a few minutes. Membrane potential oscillations were terminated by ABA. Oscillations and ABA responses were found in cell populations with active anion channels. Thus time- and voltage-dependent anion channels likely represent the ABA-sensitive conductance and part of the membrane potential oscillator. The suitability of membrane potential dyes was tested on vacuoles, too. Dye-based vacuolar membrane polarization was monitored upon ATP exposure. We conclude that voltage-sensitive dyes provide an excellent tool for the study of changes in the membrane potential in vacuole as well as guard cell populations. 相似文献
93.
Keharia Haresh Patel Hardik Madamwar Datta 《World journal of microbiology & biotechnology》2004,20(4):365-370
The nonspecific ability of anaerobic sludge bacteria obtained from cattle dung slurry was investigated for 17 different dyes
in a batch assay system using sealed serum vials. Experiments using Reactive Violet 5 (RV 5) showed that sludge bacteria could
effectively decolorize solutions having dye concentrations up to 1000 mg l−1 with a decolorization efficiency of above 75% during 48 h of incubation. Headspace gas composition of anaerobic batch systems
for varying dye concentration revealed that lower concentrations of RV 5 (upto 500 mg l−1) were found to be stimulatory to the methanogenic activity of sludge bacteria. However at higher dye concentrations, the
headspace gas composition was found to be similar to batch assay controls without dye, indicating that dye at higher concentrations
was inhibitory to methanogenic bacteria of sludge. The optimum inoculum and incubation temperature for maximum decolorization
of RV 5 was found to be 9.0 g l−1(in terms of total solids) and 37°C, respectively. Of sixteen other dyes tested, nine (Reactive Black 5, Reactive Blue 31,
Reactive Blue 28, Reactive Red HE8B, Reactive Yellow, Reactive Golden Yellow, Mordant Orange, Novatic Olive R S/D & Navilan
Yellow GL) were decolorized with more than 88% efficiency; three (Orange II, Navy Blue HER & Novatic Blue BC S/D) were decolorized
with about 50–65% efficiency, whereas other three dyes (Procion Orange H2R, Procion Brilliant Blue HGR & Novatic Blue BC S/D)
were decolorized with less than 40% efficiency. Though Ranocid Fast Blue was decolorized with about 92.5% efficiency, this
was merely due to sorption, whereas the other dyes were decolorized due to biotransformation. 相似文献
94.
Sörgjerd K Klingstedt T Lindgren M Kågedal K Hammarström P 《Biochemical and biophysical research communications》2008,377(4):1072-1078
Recent studies suggest that soluble, oligomeric species, which are intermediates in the fibril formation process in amyloid disease, might be the key species in amyloid pathogenesis. Soluble oligomers of human wild type transthyretin (TTR) were produced to elucidate oligomer properties. Employing ThT fluorescence, time-resolved fluorescence anisotropy of pyrene-labeled TTR, chemical cross-linking, and electron microscopy we demonstrated that early formed soluble oligomers (within minutes) from A-state TTR comprised on the average 20-30 TTR monomers. When administered to neuroblastoma cells these early oligomers proved highly cytotoxic and induced apoptosis after 48 h of incubation. More mature fibrils (>24 h of fibrillation) were non-toxic. Surprisingly, we also found that native tetrameric TTR, when purified and stored under cold conditions (4 °C) was highly cytotoxic. The effect could be partially restored by increasing the temperature of the protein. The cytotoxic effects of native tetrameric TTR likely stems from a hitherto unexplored low temperature induced rearrangement of the tetramer conformation that possibly is related to the conformation of misfolded TTR in amyloigogenic oligomers. 相似文献
95.
96.
97.
《Bioorganic & medicinal chemistry letters》2014,24(1):314-316
Cy-Cl, a cationic near-infrared cyanine dye, readily reacts with hydrogen sulfide (H2S) via nucleophilic thiolation to give dose-dependent ‘turn-off’ fluorescence and colorimetric read-out, allowing selective detection of low levels of H2S in serum and imaging of mitochondrial H2S in living cells. 相似文献
98.
When intact Toxoplasma trophozoites were stained with isotonic alkaline methylene blue solution, the organelles rich in nucleic acid, i.e., nucleus, free and membrane-bound ribosomes appeared as electron dense areas. When the parasites were incubated with the anti-Toxoplasma antibody and the accessory factor, swelling of the surface membrane occurred first, followed by destruction of the inner structures. In the dye test positive parasites, there were no definite organelles recognizable, as there were in the intact parasites. By the negative staining method, holes (defects) with dark central portions were observed on the surface of the parasites treated with the antibody and the accessory factor, the diameter of the holes measuring about 10–11 nm. These holes, which tended to occur in clusters, were each surrounded by a clear ring. 相似文献
99.
Michael A. Muniak Zachary M. Mayko David K. Ryugo Christine V. Portfors 《Journal of visualized experiments : JoVE》2012,(64)
It is well known that anesthesia alters neural response properties in various regions of the brain.13. In the auditory system, fundamental response properties of brainstem neurons including threshold, frequency specificity, and inhibitory sidebands are altered in significant ways under anesthesia1-2. These observations prompted physiologists to seek ways to record from single neurons without the contaminating effects of anesthesia. One result was a decerebrate preparation, where the brainstem was completely transected at the level of the midbrain4. The drawbacks of this preparation are a formidable surgery, the elimination of descending projections from the forebrain, and an inability to use sensory stimulation to examine structures above the midbrain. A different strategy has been to implant electrode arrays chronically to record from single neurons and multiunit clusters while the animal is awake and/or behaving5,6. These techniques however are not compatible with injecting tracer dyes after first electrophysiologically characterizing a brain structure. To avoid altering neural response properties with anesthetics while recording electrophysiological response properties from single neurons, we have adapted a head restraint technique long used in bats7-9 to mouse10-12. Using this method, we are able to conduct electrophysiological recordings over several days in the unanesthetized mouse. At the end of the recording sessions, we can then inject a dye to reconstruct electrode positions and recording sites or inject a tracer so that pathways to and from the recording loci can be determined. This method allows for well isolated single neuron recordings over multiple days without the use anesthetics. 相似文献
100.
《Biocatalysis and Biotransformation》2013,31(2):255-259
AbstractHydrogen peroxide was produced from bran by a two-step process using cellulase/xylanase and glucose oxidase, sequentially. The decolourization efficiency of the produced reagent was tested using paprika oil dye (effluent from industrial source) and high levels of colour removal (96%) were achieved after saponification pre-treatment and hydrogen peroxide application. The method is economically and environmentally advantageous since lower energy and chemical input are needed and wastewater pollution is considerably reduced. At the same time, the utilization of waste materials was successfully achieved. 相似文献