31 research outputs found
Flavour production in ewe's milk and ewe's milk yoghurt, by single strains and combinations of Streptococcus thermophilus
Mass transfer phenomena of gaseous hydrocarbons and nitrogen dioxide across gas-inorganic pigments boundaries
Benzene and toluene influence with or without nitrogen dioxide on inorganic pigments of works of art
Environmental catalysis studied by the reversed-flow gas chromatography. Measurements, mechanism and models
Mass transfer phenomena of gaseous hydrocarbons and nitrogen dioxide across gas-inorganic pigments boundaries
Reversed-flow gas chromatography was used to study the kinetics of the action of five hydrocarbons namely, ethane, ethene, ethyne, propene and butene and of the nitrogen dioxide, on three
known and widely used pigments, the white one TiO2, and the yellows CdS and PbCrO4. The calculation of kinetic parameters and mass transfer coefficients is based on an experimental
adsorption isotherm. All these calculations are based on a non linear adsorption isotherm model as it is well accepted that the linear one is inadequate for inorganic substances like these
mentioned in this work. The inadequacy is mainly attributed to the non-uniformity of the solid surface. Five physicochemical parameters have been obtained for each of the twenty heterogeneous
reactions studied. With these systematic experiments under conditions which are similar to the atmospheric ones, an extrapolation of the results obtained to “real" atmospheres with a high
degree of confidence is possible. Some of the calculations were based on the linear model for comparison
Time distribution of adsorption energies, local monolayer capacities, and local isotherms on heterogeneous surfaces by inverse gas chromatography
Chromatographic study of the influence of nitrogen dioxide on the reactions between volatile hydrocarbons and inorganic pigments
Time distribution of adsorption energies, local monolayer capacities, local isotherms and energy distribution functions on catalytic surfaces
Measurement of adsorption energies on heterogeneous surfaces by inverse gas chromatography
Purification and characterization of thermophilin T, a novel bacteriocin produced by Streptococcus thermophilus ACA-DC 0040
ACA-DC 0040 produced an antimicrobial agent, which was named thermophilin T, active against several lactic acid bacteria strains of different species and food spoilage bacteria, such as Clostridium sporogenes C22/10 and Cl. tyrobutyricum NCDO-1754. The crude antimicrobial compound is sensitive to proteolytic enzymes and α-amylase, heat-stable (100 °C for 30 min), resistant to pH exposure at pH 1-12 and demonstrates a bactericidal mode of action against the sensitive strain Lactococcus cremoris CNRZ-117. The production of bacteriocin was optimized approximately 10-fold in an aerobic fermenter held at constant pH 5.8 and 6.2. Ultrafiltration experiments with culture supernatant fluids containing the bacteriocin, and further estimation of molecular weight with gel filtration chromatography, revealed that bacteriocin in the native form has a molecular weight in excess of 300 kDa. SDS-gel electrophoresis of partially purified thermophilin T showed that bacteriocin activity was associated with a protein band of approximately 2.5 kDa molecular mass