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Journal of Bacteriology Nov 1944
PubMed: 16560867
DOI: 10.1128/jb.48.5.555-557.1944 -
Journal of Clinical Microbiology Mar 1982A simple new agar medium containing L-canavanine, glycine, and bromthymol blue was found to give a clearer and more accurate distinction between serotype A or D...
A simple new agar medium containing L-canavanine, glycine, and bromthymol blue was found to give a clearer and more accurate distinction between serotype A or D (Cryptococcus neoformans var. neoformans) and serotype B or C (C. neoformans var. gattii) than creatinine-dextrose-bromthymol blue or glycine-cycloheximide-phenol red media. Among 143 isolates of serotype A or D and 70 isolates of serotype B or C, the new medium correlated completely with the serotype, whereas nearly 11% of these isolates gave discrepant reactions with creatinine-dextrose-bromthymol blue and glycine-cycloheximide-phenol red media.
Topics: Cryptococcus; Cryptococcus neoformans; Culture Media; Serotyping
PubMed: 7042750
DOI: 10.1128/jcm.15.3.535-537.1982 -
International Journal of Environmental... Dec 2017The key to obtaining an optimum performance of an enzyme is often a question of devising a suitable enzyme and optimisation of conditions for its immobilization. In this...
Preparation and Optimisation of Cross-Linked Enzyme Aggregates Using Native Isolate White Rot Fungi Trametes versicolor and Fomes fomentarius for the Decolourisation of Synthetic Dyes.
The key to obtaining an optimum performance of an enzyme is often a question of devising a suitable enzyme and optimisation of conditions for its immobilization. In this study, laccases from the native isolates of white rot fungi and/or , obtained from Czech forests, were used. From these, cross-linked enzyme aggregates (CLEA) were prepared and characterised when the experimental conditions were optimized. Based on the optimization steps, saturated ammonium sulphate solution (75 wt.%) was used as the precipitating agent, and different concentrations of glutaraldehyde as a cross-linking agent were investigated. CLEA aggregates formed under the optimal conditions showed higher catalytic efficiency and stabilities (thermal, pH, and storage, against denaturation) as well as high reusability compared to free laccase for both fungal strains. The best concentration of glutaraldehyde seemed to be 50 mM and higher efficiency of cross-linking was observed at a low temperature 4 °C. An insignificant increase in optimum pH for CLEA laccases with respect to free laccases for both fungi was observed. The results show that the optimum temperature for both free laccase and CLEA laccase was 35 °C for and 30 °C for . The CLEAs retained 80% of their initial activity for and 74% for after 70 days of cultivation. Prepared cross-linked enzyme aggregates were also investigated for their decolourisation activity on malachite green, bromothymol blue, and methyl red dyes. Immobilised CLEA laccase from showed 95% decolourisation potential and CLEA from demonstrated 90% decolourisation efficiency within 10 h for all dyes used. These results suggest that these CLEAs have promising potential in dye decolourisation.
Topics: Ammonium Sulfate; Azo Compounds; Bromthymol Blue; Catalysis; Color; Coloring Agents; Cross-Linking Reagents; Enzymes, Immobilized; Glutaral; Laccase; Polyporales; Rosaniline Dyes; Temperature; Trametes
PubMed: 29295505
DOI: 10.3390/ijerph15010023 -
Food Chemistry Jan 2023Intelligent packaging that provides real-time information on food quality is useful for consumers. We developed a kimchi ripening indicator that can determine the...
Intelligent packaging that provides real-time information on food quality is useful for consumers. We developed a kimchi ripening indicator that can determine the ripeness of kimchi inside packaging and evaluated its applicability and limitations. The indicator was made using calcium hydroxide, which captures CO, and four pH-sensitive dyes (cresol red, bromothymol blue, bromocresol purple, and methyl red). Fourier-transform infrared spectra of the prepared powders showed shapes similar to that of calcium hydroxide, and the dyes were evenly distributed on the calcium hydroxide surfaces. When the developed indicators were evaluated for kimchi packaging application, the indicator made from synthesized calcium hydroxide and bromothymol blue was the most reliable and clearly reflected useful kimchi ripening information. The indicator developed in this study is judged to be practically usable at temperatures of 4-15 °C. However, its usefulness is limited in that the seller cannot change the packaging capacity or kimchi capacity.
Topics: Bromcresol Purple; Bromthymol Blue; Calcium Hydroxide; Carbon Dioxide; Coloring Agents; Fermentation; Fermented Foods; Food Packaging; Hydrogen-Ion Concentration
PubMed: 36055147
DOI: 10.1016/j.foodchem.2022.134039 -
Journal of Clinical Microbiology Oct 1977A new plating medium using bromothymol blue (BTB) indicator is described and compared with eosin-methylene blue (EMB), MacConkey, and Endo media. These media were tested... (Comparative Study)
Comparative Study
A new plating medium using bromothymol blue (BTB) indicator is described and compared with eosin-methylene blue (EMB), MacConkey, and Endo media. These media were tested with L-arabinose by plating fermenting and nonfermenting mutant strains of Escherichia coli. The minimum concentrations of L-arabinose that permitted differentiation of these strains were determined. Different concentrations were required for differentiating confluent patches of cells, isolated colonies, and closely spaced or adjacent colonies. L-Arabinose, L-rhamnose, D-lactose, and D-galactose were tested with modified enteric media and with BTB medium, again to determine minimum usable concentrations. BTB media and reformulated conventional media allowed detection of acidification, aerobically, at one-fifth to one-hundredth the (1%, wt/vol) concentration of carbohydrate used in standard indicator plates.
Topics: Aerobiosis; Arabinose; Bacteria; Bromthymol Blue; Carbohydrate Metabolism; Culture Media; Escherichia coli; Hydrogen-Ion Concentration; Indicators and Reagents; Mutation; Peptones; Stereoisomerism; Thymol
PubMed: 21196
DOI: 10.1128/jcm.6.4.343-347.1977 -
European Journal of Biochemistry Mar 1968
Topics: Animals; Anti-Bacterial Agents; Chemical Phenomena; Chemistry; Hydrogen-Ion Concentration; Indicators and Reagents; Membrane Potentials; Membranes; Methods; Mitochondria, Liver; Oxidation-Reduction; Rats; Spectrophotometry; Time Factors
PubMed: 5646151
DOI: 10.1111/j.1432-1033.1968.tb00166.x -
International Journal of Biological... May 2023Continuous wound monitoring is one strategy to minimise infection severity and inform prompt variations in therapeutic care following infection diagnosis. However,...
Continuous wound monitoring is one strategy to minimise infection severity and inform prompt variations in therapeutic care following infection diagnosis. However, integration of this functionality in therapeutic wound dressings is still challenging. We hypothesised that a theranostic dressing could be realised by integrating a collagen-based wound contact layer with previously demonstrated wound healing capability, and a halochromic dye, i.e. bromothymol blue (BTB), undergoing colour change following infection-associated pH changes (pH: 5-6 ➔ >7). Two different BTB integration strategies, i.e. electrospinning and drop-casting, were pursued to introduce long-lasting visual infection detection capability through retention of BTB within the dressing. Both systems had an average BTB loading efficiency of 99 wt% and displayed a colour change within 1 min of contact with simulated wound fluid. Drop-cast samples retained up to 85 wt% of BTB after 96 h in a near-infected wound environment, in contrast to the fibre-bearing prototypes, which released over 80 wt% of BTB over the same time period. An increase in collagen denaturation temperature (DSC) and red shifts (ATR-FTIR) suggest the formation of secondary interactions between the collagen-based hydrogel and the BTB, which are attributed to count for the long-lasting dye confinement and durable dressing colour change. Given the high L929 fibroblast viability in drop-cast sample extracts (92 %, 7 days), the presented multiscale design is simple, cell- and regulatory-friendly, and compliant with industrial scale-up. This design, therefore, offers a new platform for the development of theranostic dressings enabling accelerated wound healing and prompt infection diagnosis.
Topics: Humans; Precision Medicine; Bandages; Collagen; Wound Healing; Surgical Wound Infection; Bromthymol Blue; Hydrogels
PubMed: 36870632
DOI: 10.1016/j.ijbiomac.2023.123866 -
Journal of Agricultural and Food... Nov 2020This work presents a colorimetric dye-based array for naked-eye detection of chicken meat spoilage. The array is obtained by fixing five acid-base indicators, -cresol...
This work presents a colorimetric dye-based array for naked-eye detection of chicken meat spoilage. The array is obtained by fixing five acid-base indicators, -cresol purple (), -cresol red (), bromothymol blue (), thymol blue (), and chlorophenol red (), and a sensing molecule specific for thiols, 5,5'-dithiobis(2-nitrodibenzoic acid), called Ellman's reagent (), on a cellulose-based support. The dyes, being permanently charged, are fixed on the support via ion-exchange. The entire degradation process of beast poultry meat, at ambient temperature and in a domestic fridge, is followed by the change of the color of the array, placed in the headspace over the meat samples. The device is set after selection of the most suitable starting form, which could be the acidic or the basic color of indicators, being the proper dye concentration and the dimension of the spots already established. Basing on sensors colors, we identified three levels of the degradation process of chicken meat, named SAFE, WARNING, and HAZARD. By instrumental analysis, we demonstrated that sensors response was correlated to volatile organic compounds (VOCs) composition in the headspace and, thus, to meat spoilage progress. We demonstrated that biogenic amines (BAs), commonly considered a critical spoilage marker, are indeed produced into the samples but never present in the headspace, even in traces, during the investigated time-lapse. The VOC evolution nevertheless allows one to assign the sample as WARNING and further HAZARD. Some indicators turned out to be more informative than others, and the best candidates for a future industrial application resulted in a bromothymol blue ()-, chlorophenol red ()-, and Ellman's reagent ()-based array.
Topics: Animals; Bromthymol Blue; Chickens; Color; Colorimetry; Coloring Agents; Food Analysis; Food Safety; Meat; Phenolsulfonphthalein; Thymolphthalein; Volatile Organic Compounds
PubMed: 33118801
DOI: 10.1021/acs.jafc.0c03771 -
The Journal of Biological Chemistry Feb 1975The properties of human methemoglobin have been investigated under a wide variety of conditions to determine its conformation and to test for evidence of the T state...
The properties of human methemoglobin have been investigated under a wide variety of conditions to determine its conformation and to test for evidence of the T state conformation which has been proposed by Perutz to exist in the presence of high spin ligands and inositol hexaphosphate (IHP). Subunit dissociation was measured as a criterion for the T state since marked differences in the tetramer-dimer equilibrium exist for oxyhemoglobin (R state) and deoxyhemoglobin (T state). In the absence of IHP, complexes of methemoglobin with both high spin ligands (water, fluoride) or low spin ligands (azide, cyanide) show extensive dissociation in 2,2-bis(hydroxymethyl)-2,2',2"-nitriloethanol buffers, pH 6, 0.1 M NaCl, with values of the tetramer-dimer dissociation constant (K4,2) near 10-5 M. The addition of IHP lowers K4,2 to a value near 10-5 M for all forms of methemoglobin. Combination of IHP with methemoglobin promotes a conformational change, but the change is apparently independence of spin state. The conformation acquired in the presence of IHP is not identical with the T state (K4,2 similar to 10-12 M) and can also occur with hemoglobin in the ferrous form, as revealed by a substantial reduction in K4,2 for CO-hemoglobin upon addition of IHP. Subunit dissociation has also been measured using the haptoglobin reaction, since haptoglobin binds only to hemoglobin dimers. The haptoglobin experiments give results that are qualitatively in agreement with the conclusions reached by ultracentrifuge measurements. Similar results are also obtained by estimating the degree of dissociation on the basis of the material which aggregates following mixing with dithionite. The effect of IHP on azide-binding kinetics with methemoglobin has also been examined. Changes in reactivity is observed upon addition of IHP, but the principal effect is observed upon addition of IHP, but the principal effect is an enhancement of the rate of reaction of the beta chains. Changes in the reactivity of the beta93 sulfhydryl group of methemoglobin also accompany addition of IHP, but in a manner which is largely independent of the spin state of the iron. Similar changes are again found with CO-hemoglobin upon addition of IHP. The rate of binding of bromthymol blue also shows some changes upon addition of IHP, but the changes are more pronounced for deoxyhemoglobin than for methemoglobin. Since the results obtained did not appear to indicate a significant role for spin state in the changes observed, additional studies were undertaken using EPR spectroscopy.
Topics: Azides; Binding Sites; Cyanides; Electron Spin Resonance Spectroscopy; Hemoglobins; Humans; Hydrogen-Ion Concentration; Inositol; Kinetics; Ligands; Macromolecular Substances; Mercuribenzoates; Methemoglobin; Nitriles; Protein Binding; Protein Conformation; Spin Labels; Time Factors; Ultracentrifugation
PubMed: 234444
DOI: No ID Found -
European Journal of Biochemistry Nov 1968
Topics: Adenosine Triphosphate; Animals; Dinitrophenols; Hydrogen-Ion Concentration; Membrane Potentials; Membranes; Mitochondria, Liver; Osmolar Concentration; Phenolphthaleins; Rats; Rotenone; Spectrophotometry; Succinates
PubMed: 5725505
DOI: 10.1111/j.1432-1033.1968.tb00439.x