Search results for "SUCROSE"
showing 10 items of 178 documents
Bee pollen, a substrate that stimulates ochratoxin A production by Aspergillus ochraceus Wilh.
2004
The capacity of bee pollen as a substrate for production of ochratoxin A (OTA) by a strain of Aspergillus ochraceus was studied. For control purposes corn, wheat and rice grains, and eleven liquid media were assayed. They were Yeast Extract Sucrose broth (YES), YES supplemented with 0.05, 0.1, 0.5, 1 and 5% bee pollen, YES supplemented with 0.5% peptone, 50% must, Wickerham medium, Aflatoxin Production medium and Coconut Broth Medium. Cultures were maintained at 28 degrees C for 4 weeks and were analyzed every seven days for OTA by liquid chromatography with fluorescence detection. OTA production in bee pollen was significantly (P < 0.01) higher than production in corn, wheat and rice grain…
Myoglobin embedded in saccharide amorphous matrices: water-dependent domains evidenced by small angle X-ray scattering
2010
We report Small Angle X-ray Scattering (SAXS) measurements performed on samples of carboxy-myoglobin (MbCO) embedded in low-water trehalose glasses. Results showed that, in such samples, "low-protein" trehalose-water domains are present, surrounded by a protein-trehalose-water background; such finding is supported by Infrared Spectroscopy (FTIR) measurements. These domains, which do not appear in the absence of the protein and in analogous sucrose systems, preferentially incorporate the incoming water at the onset of rehydration, and disappear following large hydration. This observation suggests that, in organisms under anhydrobiosis, analogous domains could play a buffering role against th…
Choice alters Drosophila oviposition site preference on menthol
2013
Summary Food choice and preference relies on multiple sensory systems that are under the control of genes and sensory experience. Exposure to specific nutrients and nutrient-related molecules can change food preference in vertebrates and invertebrates. For example, larval exposure of several holometabolous insects to menthol can change their adult response to this molecule. However, studies involving Drosophila melanogaster exposure to menthol produced controversial results due maybe to methodological differences. Here, we compared the oviposition-site preference of wild-type D. melanogaster lines freely or forcibly exposed to menthol-rich food. After 12 generations, oviposition-site prefer…
Determination of sugars in depilatory formulations: a green analytical method employing infrared detection and partial least squares regression.
2011
A green analytical method was developed for the analysis of sugar-based depilatories. Three independent partial least squares (PLS) regression models were built for the direct determination of glucose, fructose and maltose without any sample pretreatment based on their attenuated total reflectance - Fourier transform infrared (ATR-FTIR) spectra. The models showed adequate prediction capabilities with root-mean-square-errors of prediction ranging from 7.04 to 12.55 mg sugar g(-1) sample. As a reference procedure, gradient liquid chromatography with on-line infrared detection, employing background correction based on cubic smoothing splines, was used. The analysis revealed changes in the suga…
Reversion of 7-methylguanosine 5′-phosphate inhibition of mRNA translation by polysomal and soluble factors isolated from Saccharomyces cerevisiae
1987
Abstract Protein fractions that overcome m7GMP inhibition of mRNA translation have been purified from the yeast S. cerevisiae . An active fraction isolated from polysomes contains two polypeptides of 220- and 190-kDa. The active fraction isolated from postribosomal supernatant contains a major polypeptide of 28-kDa and other species of 32-, 24-, 22- and 21-kDa, and sediments in sucrose gradients as a high molecular weight complex of about 200000. This fraction restored yeast mRNA translation in reticulocyte lysates under conditions of yeast and globin mRNA competition; however, this effect was not observed with the 220- and 190-kDa polypeptides from polysomes. Nevertheless, translation of y…
Comparative evaluation of Nano-Hydroxyapatite preparation and Calcium Sucrose Phosphate on microhardness of deciduous teeth after iron drop exposure …
2016
Background To evaluate and compare the microhardness of deciduous teeth treated with nano-hydroxyapatite and calcium sucrose phosphate after iron drop exposure. Material and Methods Twenty healthy anterior deciduous teeth were collected and stored in 0.9% saline solution at room temperature. All the teeth were immersed in artificial saliva in an incubator shaker at 37° for an hour and then subjected to Vickers microhardness test at 100g load for 5 seconds. The teeth were then immersed in iron drop for 5 minutes, twice daily, rinsed with distilled water and kept in artificial saliva. This procedure was repeated for 7 days and teeth were subjected to microhardness testing. Further, the teeth …
Roles of sorbitol and sucrose in growth and respiration of ‘Encore’ peach fruit in the three developmental stages
2002
In peach [Prunus persica (L.) Batsch (Peach Group)], both sorbitol and sucrose are utilized for source to sink carbon (C) transport, yet their specific functions in fruit growth and development remain unclear. Growth rate (GR), respiration rate (R), carbohydrate content, and the activities of sorbitol dehydrogenase (SDH), sorbitol oxidase (SOX), sucrose synthase (SS), acid invertase (AI), and neutral invertase (NI) were determined in ‘Encore’ peach fruit to study the specific functions of sorbitol and sucrose in each phase of fruit development (an early period of rapid cell division, a relatively inactive intermediate stage where endocarp (pit) hardening occurs, and a final swelling due to …
Effect of different cryopreservation protocols on the metaphase II spindle in human oocytes.
2008
The aim of this study was to evaluate the impact of different cryopreservation protocols on the repolymerization of metaphase (M)II spindles in human oocytes. Fresh aspirated donor oocytes were cryopreserved 3–4 h after retrieval using four different protocols: slow freezing using 1.5 mol/l 1,2-propanediol (PROH) + 0.2 mol/l sucrose (n = 36); 1.5 mol/l PROH + 0.3 mol/l sucrose (n = 34); 1.5 mol/l PROH + 0.3 mol/l sucrose with Na + depleted–choline replaced media (n = 27), and vitrification by the Cryotip method (n = 23). The control group comprised 34 fresh oocytes. Three hours after thawing, surviving and control oocytes were fixed for meiotic spindle/chromatin assessment. Survival rates w…
SAXS Study on Myoglobin Embedded in Amorphous Saccharide Matrices
2011
We report on Small Angle X-ray Scattering (SAXS) measurements performed on samples of carboxy-myoglobin and met-myoglobin embedded in low hydrated matrices of four different saccharides (trehalose, sucrose, maltose and lactose). Results confirm the already reported occurrence of inhomogeneities, which are not peculiar of trehalose samples, but appear also in maltose and lactose, and in some cases also sucrose, being dependent on the sample hydration and on the presence of sodium dithionite. This behaviour confirms our previous interpretation about the nature of the inhomogeneities, and prompt it as a possible general behaviour for highly concentrated sugar matrices.
Levansucrases from Pseudomonas syringae pv. tomato and P. chlororaphis subsp. aurantiaca: Substrate specificity, polymerizing properties and usage of…
2011
Levansucrases of Pseudomonas syringae pv. tomato DC3000 (Lsc3) and Pseudomonas chlororaphis subsp. aurantiaca (also Pseudomonas aurantiaca) (LscA) have 73% identity of protein sequences, similar substrate specificity and kinetic properties. Both enzymes produce levan and fructooligosaccharides (FOS) of varied length from sucrose, raffinose and sugar beet molasses. A novel high-throughput chip-based nanoelectrospray mass spectrometric method was applied to screen alternative fructosyl acceptors for levansucrases. Lsc3 and LscA could both transfructosylate D-xylose, D-fucose, L- and D-arabinose, D-ribose, D-sorbitol, xylitol, xylobiose, D-mannitol, D-galacturonic acid and methyl-α-D-glucopyra…