Search results for "Lecithin"
showing 10 items of 61 documents
Chromosome-Encoded Hemolysin, Phospholipase, and Collagenase in Plasmidless Isolates of Photobacterium damselae subsp. damselae Contribute to Virulen…
2017
ABSTRACT Photobacterium damselae subsp. damselae is a pathogen of marine animals, including fish of importance in aquaculture. The virulence plasmid pPHDD1, characteristic of highly hemolytic isolates, encodes the hemolysins damselysin (Dly) and phobalysin (PhlyP). Strains lacking pPHDD1 constitute the vast majority of the isolates from fish outbreaks, but genetic studies to identify virulence factors in plasmidless strains are scarce. Here, we show that the chromosome I-encoded hemolysin PhlyC plays roles in virulence and cell toxicity in pPHDD1-negative isolates of this pathogen. By combining the analyses of whole genomes and of gene deletion mutants, we identified two hitherto uncharacte…
Impact of Lipid Components and Emulsifiers on Plant Sterols Bioaccessibility from Milk-Based Fruit Beverages.
2016
Sterol bioaccessibility (BA) of three plant sterol (PS)-enriched milk-based fruit beverages (MFb) with different fat contents (1.1–2.4%), lipid sources (animal or vegetable), and without or with emulsifiers (whey proteins enriched with milk fat globule membrane (MFGM) or soy lecithin) was evaluated after simulated gastrointestinal digestion. The BA of total PS followed the order 31.4% (MFbM containing milk fat and whey proteins enriched with MFGM) = 28.2% (MFbO containing extra virgin olive oil and soy lecithin) > 8.7% (MFb without fat addition). Total and individual PS content in the bioaccessible fractions followed the order MFbM > MFbO > MFb. Consequently, formulation with MFGM is propos…
The effect of organic solvents on selected microorganisms and model liposome membrane
2019
The effect of methanol, ethanol, acetone, N,N-dimethylformamide (DMF), dimethyl sulfoxide and Nujol on the growth of Escherichia coli DH5α, Bacillus subtilis and Saccharomyces cerevisiae D273 was investigated. All of the tested cultures appeared susceptible to the organic media they were treated with, which evinced in apparent hindering of cell development. The observed diverse solvent tolerance, except from their different biochemical activity, may also be related to the changes in cell membrane fluidity induced by the solvent species. Parallel electron paramagnetic resonance investigations using egg yolk lecithin model liposomes revealed that the fluidity of the phospholipid system in cel…
The influence of natural and model forms of humic acids on the dynamic parameters of model membranes
2016
In this paper the influence of humic acid concentrations extracted from Histosols (HA-A) and their model forms (HA-B) separated from humic substances commercially produced by Carl Roth GmbH + Co.KG on the dynamic properties of liposome membranes was determined. Differences in the quality of the humic acids (HA-A and HA-B) were determined by the 1HNMR and FTIR methods. Liposomes from the sonication of egg yolk lecithin (EYL) in an aqueous solution and synthetic Dipalmitoylphosphatidylcholine (DPPC) were used. Fluidity of liposome membranes was determined by the EPR technique with spin probes (TEMPO, 16DOIXYL). The electrical parameters of membranes were found using a Keithley 6517 electromet…
Physico-chemical investigation of the state of cyanamide confined in AOT and lecithin reversed micelles
2004
Sodium bis(2-ethylhexyl)sulfosuccinate (AOT) and lecithin reversed micelles containing cyanamide have been investigated by small-angle X-ray scattering, FT-IR, and 1H NMR spectroscopy at various cyanamide-to-surfactant molar ratio (X) and at fixed surfactant concentration (0.1 mol kg-1). Experimental data are consistent with a model of cyanamide molecules confined in reversed micelles, quite uniformly distributed among them and mainly located among surfactant headgroups. SAXS data analysis leads also to hypothesize a unidimensional growth of the reversed micelles with increasing the X value. Moreover, the cyanamide state and the cyanamide/cyanamide interactions in reversed micelles have bee…
Changes in plasma lecithin: cholesterol acyltransferase activity, HDL2, HDL3 amounts and compositions in patients with chronic renal failure after di…
2002
The aim of this study was to investigate the effect of hemodialysis duration on HDL(2) and HDL(3) compositions and lecithin:cholesterol acyltransferase (LCAT) activity in 58 patients on acetate hemodialysis using cuprophane membrane, after different periods of dialysis. Patients were divided into three groups-GI1 year, GII 1-5 years, GIII 5-13 years of dialysis and were compared with 22 controls. Increase by 34% of triacylglycerols (TG) was noted in GI and by 36% in GII versus GI. Hypertriglyceridemia was correlated with hemodialysis duration (HD) (r=0.75, P0.05). The LCAT activity decrease by 25% was noted in GII versus GI (P0.05) and by 45% in GIII versus GI (P0.01), this activity was neg…
Calorimetric investigation of water/lecithin/cyclohexane microemulsions
1997
The enthalpies of dilution of water/lecithin/cyclohexane microemulsion-gels at variousR values (R=[water]/[lecithin]) and molar enthalpies of solution of water in lecithin/cyclohexane at a fixed lecithin concentration were determined calorimetrically at 25°C. Through a description of the process of dilution of water/lecithin/cyclohexane microemulsion-gels as one involving mainly the scission of lecithin reversed micelles in to smaller ones, the concentration dependence of the enthalpy was rationalized. Surprisingly, in order to account for the dilution enthalpies, it was not necessary to hypothesize a thermal effect arising from the breakage of the micellar network present in the micremulsi…
Determination of lecithin and soybean oil in dietary supplements using partial least squares-Fourier transform infrared spectroscopy.
2008
Lecithin and soybean oil in dietary supplements were determined by Fourier transform infrared spectrometry transmission measurements in dichloromethane in combination with a partial least squares (PLS) regression. Two different PLS models were developed, using 16 synthetic mixtures of analytes in dichloromethane, making measurements in the spectral range from 931.8 to 1252.3 cm(-1) for lecithin and from 911.4 to 1246.9 cm(-1) and 1695.3 to 1774.5 cm(-1) for soybean oil. Seven products from the Spanish market with lecithin concentrations between 21.1% and 99.1% and soybean oil concentrations between 0% and 37.2% were analyzed by the proposed method and the data was compared to a chromatograp…
FT-IR investigation of the urea state in lecithin and sodium bis(2-ethylhexyl)phosphate reversed micelles
2003
Abstract FT-IR spectra of urea/lecithin/CCl4 and urea/sodium bis(2-ethylhexyl) phosphate (NaDEHP)/CCl4 systems as a function of the urea-to-surfactant molar ratio (Rurea) at a fixed surfactant concentration (0.1 mol kg−1) have been recorded at 25 °C. Analysis of the absorption spectra leads the to hypothesis that urea is confined within the hydrophilic micellar core of lecithin and NaDEHP reversed micelles. The encapsulation of urea involves some changes of the urea NH stretching band with respect to that of the pure solid urea, attributable to confinement effects. The stretching modes of the surfactant head group are affected by the presence of urea, indicating specific urea-surfactant hea…
On-line gel permeation chromatography–attenuated total reflectance–Fourier transform infrared determination of lecithin and soybean oil in dietary su…
2007
Gel permeation chromatography (GPC) with attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrometry detection has been proposed for the simultaneous determination of lecithin and soybean oil in dietary supplements. The method involves the extraction of analytes with dichloromethane in an ultrasound water bath and the injection of 2 ml of centrifuged and filtered extracts into the system integrated by two Envirogel GPC columns (19 mm x150 mm, 19 mm x 300 mm) coupled on-line. Dichloromethane was used as mobile phase. A method has been developed to select the most appropriated wavenumber to be used for the determination of each considered compound from the calculation of a…