Effect of ultraviolet radiation on physiological and biochemical properties of yeast Saccharomyces cerevisiae during fermentation of ultradispersed starch raw material

Background: Study of correlation between pretreatment of yeast with ultraviolet radiation and efficiency of further fermentation of wort made of ultrafine grain particles to ethanol. Results: We investigated three races of industrial yeast Saccharomyces cerevisiae (native and irradiated by ultraviolet). Physiological properties during fermentation of starchy wort were tested in all variants. It was shown that activation of the yeast by ultraviolet radiation allows to further increase the ethanol yield by 25% on average compared with the native yeast races when using thin (up to micro- and nano-sized particles) or standard grain grinding. Conclusions: Using mechanical two-stage grinding of starchy raw materials and ultraviolet pretreatment of yeast, the efficiency of saccharification of starch and fermentation of wort to ethanol was increased.

Atomic modifications by synchrotron radiation at the calcite-ethanol interface.

This article reports on studies of the chemical alterations induced by synchrotron radiation at the calcite-ethanol interface, a simple model system for interfaces between minerals and more complex organic molecules containing OH groups. A combination of X-ray reflectivity and X-ray photoelectron spectroscopy of natural calcite, cleaved in distilled ethanol to obtain new clean interfaces, indicated that, during a 5 h period, the two top atomic layers of calcite, CaCO(3), transform into calcium oxide, CaO, by releasing CO(2). Also, the occupation of the first ordered layer of ethanol attached to calcite by hydrogen bonds almost doubles. Comparison between radiated and non-radiated areas of the same samples demonstrate that these effects are induced only by radiation and not caused by aging. These observations contribute to establishing a time limit for synchrotron experiments involving fluid-mineral interfaces where the polar OH group, as present in ethanol, plays a key role in their molecular structure and bonding. Also, the chemical evolution observed in the interface provides new insight into the behavior of some complex organic molecules involved in biomineralization processes.

Effects of curcumin and related compounds on processes involving α-hydroxyethyl radicals.

Effects of curcumin and related compounds on product formation in radiolysis of aerated and deaerated ethanol were studied. Ab initio calculations of enthalpy values relating to O-H bond dissociation and H-atom addition to > C = O bonds of the compounds under study have been performed. The obtained data allowed the conclusion that the presence of a 7-carbon chain containing conjugated > C = C < and > C = O bonds in the structures of curcumin and its analogues makes these compounds capable of inhibiting the reactions involving α-hydroxyl-containing carbon-centered radicals. This finding broadens the existing views concerning radical-regulating properties of curcuminoids, and it should be taken into account when practical use of these compounds is envisaged.

Ultrasound-assisted synthesis of aliphatic acid esters at room temperature.

This work describes the ultrasound-assisted synthesis of saturated aliphatic esters from synthetic aliphatic acids and either methanol or ethanol. The products were isolated in good yields after short reaction times under mild conditions.

Efficient bioconversion of rice straw to ethanol with TiO2/UV pretreatment.

Rice straw is a lignocellulosic biomass that constitutes a renewable organic substance and alternative source of energy; however, its structure confounds the liberation of monosaccharides. Pretreating rice straw using a TiO(2)/UV system facilitated its hydrolysis with Accellerase 1000(™), suggesting that hydroxyl radicals (OH·) from the TiO(2)/UV system could degrade lignin and carbohydrates. TiO(2)/UV pretreatment was an essential step for conversion of hemicellulose to xylose; optimal conditions for this conversion were a TiO(2) concentration of 0.1% (w/v) and an irradiation time of 2 h with a UV-C lamp at 254 nm. After enzymatic hydrolysis, the sugar yields from rice straw pretreated with these parameters were 59.8 ± 0.7% of the theoretical for glucose (339 ± 13 mg/g rice straw) and 50.3 ± 2.8% for xylose (64 ± 3 mg/g rice straw). The fermentation of enzymatic hydrolysates containing 10.5 g glucose/L and 3.2 g xylose/L with Pichia stipitis produced 3.9 g ethanol/L with a corresponding yield of 0.39 g/g rice straw. The maximum possible ethanol conversion rate is 76.47%. TiO(2)/UV pretreatment can be performed at room temperature and atmospheric pressure and demonstrates potential in large-scale production of fermentable sugars.

Ethanol enrichment from ethanol-water mixtures using high frequency ultrasonic atomization.

The influence of high frequency ultrasound on the enrichment of ethanol from ethanol-water mixtures was investigated. Experiments performed in a continuous enrichment system showed that the generated atomized mist was at a higher ethanol concentration than the feed and the enrichment ratio was higher than the vapor liquid equilibrium curve for ethanol-water above 40 mol%. Well-controlled experiments were performed to analyze the effect of physical parameters; temperature, carrier gas flow and collection height on the enrichment. Droplet size measurements of the atomized mist and visualization of the oscillating fountain jet formed during sonication were made to understand the separation mechanism.

Application of ultrasound in the dissolution of potential antiophidian compounds from two ethanolics extracts of two species of Heliconias.

This study evaluates the favorable effects of using ultrasound during the dissolution process of ethanolic extracts of Heliconia psittacorum and Heliconia rostrata (Heliconiaceae), a family of plants reported to have antiophidic activities. The extracts were subjected to an ultrasound treatment before incubation with venom, and carbohydrate and protein contents were calculated. The ultrasound-treated extracts delayed the clotting effect of venom by up to 45.59 s compared to the positive control (venom). The metabolites content increased to 296.6% and 61.6% in protein and carbohydrate content, respectively. Ultrasound increases the amount of primary and secondary metabolites (potentially antiophidics) released from the extract into the media, and thereby enhances the anticoagulant activity of these plants against the Bothrops asper (mapaná X) venom.

An elastically compressible phantom material with mechanical and x-ray attenuation properties equivalent to breast tissue.

We have developed a novel phantom material: a solution of polyvinyl alcohol (PVAL) in ethanol and water, freeze-thawed to produce a solid yet elastically compressible gel. The x-ray attenuation and mechanical properties of these gels are compared with published measurements of breast tissue. Gels with PVAL concentrations from 5 to 20% w/v were produced. The linear x-ray attenuation coefficients of these gels range from 0.76 to 0.86 cm(-1) at 17.5 keV, increasing with PVAL concentration. These values are very similar to the published values of breast tissue at this energy, 0.8-0.9 cm(-1). Under compression cancerous breast tissue is approximately ten times stiffer than healthy breast tissue. The Young's moduli of the gels increase with PVAL concentration. Varying the PVAL concentration from 7.5 to 20% w/v produces gels with Young's moduli from 20 to 220 kPa at 15% strain. These values are characteristic of normal and cancerous breast tissue, respectively.

Ultrasound-assisted one-pot, three-component synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-diones.

Triethylamine was found to be an efficient catalyst for the synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-diones by one-pot reaction of phthalhydrazide, aromatic aldehydes, and malononitrile or ethyl cyanoacetate in ethanol under ultrasonic irradiation. The advantages of this method are the use of an inexpensive and readily available catalyst, easy workup, improved yields, and the use of ethanol as a solvent that is considered to be relatively environmentally benign.

Photocatalytic oxidation of organic pollutants on titania-clay composites.

TiO2/Ca-montmorillonite composites were prepared by wet grinding in an agate mill. Positively charged TiO2 nanoparticles are bound to the surface of the negatively charged montmorillonite layers via heterocoagulation; the clay mineral is used as adsorbent and support for the photooxidation process. Aquatic solution of 0.5mM phenol was degraded by irradiation with UV-VIS light (lambda=250-440 and 540-590 nm) in suspensions of TiO2-clay composites and significant photodegradation was observed at 40-60% TiO2/Ca-montmorillonite compositions. Synergistic effect was detected at solid/liquid interface for degradation of phenol and at solid/gas interface in the recycling flow reactors for photooxidation of ethanol and toluene vapors.

Mathematical model for photocatalytic destruction of organic contaminants in air.

Photocatalytic oxidation (PCO) was investigated in a bench-scale reactor for the abatement of two airborne organic contaminants: toluene and ethanol. A mathematical model that includes the impacts of light intensity, initial contaminant concentration, catalyst thickness, and relative humidity (RH) on the degradation of organic contaminants in a photocatalytic reactor was developed to describe this process. The commercially available catalyst Degussa-PtTiO2 was selected to compare with the MTU-PtTiO2-350 catalyst, which was synthesized by the sol-gel process, platinized, and calcined at 350 degrees C. For toluene removal using the MTU-PtTiO2-350 catalyst, the degradation rate increased with increases in light intensity from 0.2 to 2.2 mW/cm2 and in catalyst thickness from 0.00037 to 0.00361 cm. However, further increases in light intensity and catalyst thickness had only slight effect on the toluene degradation rate. Increasing the initial concentration from 6.29 to 127.9 microg/L and the RH from 10 to 85% resulted in decreases in the toluene degradation rate. For ethanol removal using the MTU-PtTiO2-350 catalyst, the degradation rate increased more rapidly with an increase in RH from 17 to 56%; the RH had little effect on the ethanol degradation rate while it further increased from 56% to 82%. We discuss applicability of the model to estimate the influence of process variables and to evaluate photocatalyst performance.

Neutron response of the chlorobenzene-ethanol-trimethylpentane dosimetry system.

The dosimetric use of the chemical solution chlorobenzene-ethanol-trimethylpentane (CET) is based on the radiolytic formation of hydrochloric acid, which protonates a pH indicator thymolsulphonphthalein. On the basis of the CET solution, an accident and emergency personal dosemeter was designed allowing doses in the range 0.2-15 Gy can be measured. Radiation-chemical yields, G(HCl), for the CET system, and the responses of dosemeters in different neutron fields, ranging from 0.35 to 19.3 MeV mean energy neutrons, are summarised. The relation of G(HCl) to linear energy transfer (LET) of incident heavy charged particles is also evaluated on the basis of the previously published data. The response of the CET system to monoenergetic neutrons was calculated from the measured dependence of the G value upon LET of heavy charged particles and data about the LET distribution for monoenergetic neutrons. A very good agreement between this calculation and the experimental results was obtained. These results enable predictions of the response to be made in radiation fields with the known LET distributions.

Photoirradiation of retinyl palmitate in ethanol with ultraviolet light--formation of photodecomposition products, reactive oxygen species, and lipid peroxides.

We have previously reported that photoirradiation of retinyl palmitate (RP), a storage and ester form of vitamin A (retinol), with UVA light resulted in the formation of photodecomposition products, generation of reactive oxygen species, and induction of lipid peroxidation. In this paper, we report our results following the photoirradiation of RP in ethanol by an UV lamp with approximately equal UVA and UVB light. The photodecomposition products were separated by reversed-phase HPLC and characterized spectroscopically by comparison with authentic standards. The identified products include: 4-keto-RP, 11-ethoxy-12-hydroxy-RP, 13-ethoxy-14-hydroxy-RP, anhydroretinol (AR), and trans- and cis-15-ethoxy-AR. Photoirradiation of RP in the presence of a lipid, methyl linoleate, resulted in induction of lipid peroxidation. Lipid peroxidation was inhibited when sodium azide was present during photoirradiation which suggests free radicals were formed. Our results demonstrate that, similar to irradiation with UVA light, RP can act as a photosensitizer leading to free radical formation and induction of lipid peroxidation following irradiation with UVB light.

Radiolytic transformation of 2,2',4'-trihydroxychalcone.

Radiolysis of 2,2',4'-trihydroxychalcone, a natural antioxidant present in fruit and vegetables, was performed in ethanol in the absence or in the presence of dioxygen. The degradation process of chalcone was followed in de-aerated solution by HPLC, NMR, FAB-LSIMS mass spectroscopy and analytical TLC. Under anaerobic conditions, six new products (three couples of diastereoisomers) were identified. Four of them kept the chalcone skeleton with OCH(2)CH(3), CH(OH)CH(3) and H substitutions on C(alpha) and C(beta). Thus the target was the alpha-beta double bond on which ethanol radicals were added. The two other compounds were formed in a second stage and exhibited a cyclization between the substituent on C(beta) and the carbonyl group. In the presence of dioxygen, these reactions were prevented and chalcone was protected. This study was the first step toward understanding of the behavior chalcone in irradiated fruits and vegetables.

Ligand effects on ESR and optical properties of gold atoms in gamma irradiated organic solid solutions at 77 K.

Ligand effects on ESR and optical properties of Au0 atoms produced at 77 K in gamma irradiated solid solutions of AuCl/MTHF and AuCl/EtOH with and without HCl were investigated. Four groups of ESR lines were observed at 73 K more clearly around the magnetic fields at about 250, 280, 340, and 400 mT for both gamma irradiated MTHF and EtOH solid solutions with HCl than those without HCl. The values of a and g(J) calculated by Breit-Rabi analysis showed a remarkable dependence on the solvent polarity. It was confirmed that the signals were the hyperfine quartet corresponding to the transitions between the Zeeman levels of Au0 atoms with nuclear spin of 3/2 in the ground state, 2S(1/2). It was also confirmed that Au0 atoms produced after gamma irradiation were located in the nuclear environment of isotropic interaction with surrounding ligand molecules. Delocalization of the unpaired spin density of Au0 onto ligands is found to be as large as one in the case of Cu0 atoms. Our previous hypothesis of the occurrence of configuration mixing of d valence orbital into the wave function of the atom in its 2S(1/2) was strongly supported. The dependence of the ESR, optical absorption, and the steady-state emission and excitation characteristics on solvent polarity was cleared in this study. We observed two kinds of emissions i.e., a band at 385 nm and a set of emission bands at 456, 482, 484, and 520 nm. These correspond to two bands out of the six kinds of emissions observed previously. The bands were attributed to exciplex (Au0 x Ln...Au+)* and the excited Au0 atoms trapped in a large cavity, respectively. The negative counterion of Au+ of the gold compound plays an important role for the formation of the exciplexes.

Structure of copper(II) dithiocarbamate mixed-ligand complexes and their photoreactivities in alcohols.

The composition of the co-ordination sphere of Cu(II) dithiocarbamate mixed-ligand complexes Cu(Et2)dtc)X (X = Cl-, Br-) and Cu(Et2)dtc)(+)...Y- (Y- = ClO4-, NO3-) is studied from the combined analysis of spectrophotometric and EPR data. The results obtained about CT-photolysis of the complexes in EtOH and i-PrOH are compared with our previous data of photolysis in chloromethane/ROH solutions. Reaction mechanism and the role of alcohol are discussed on the ground of electronic and EPR spectra and quantum yield results.

Solid-state NMR studies of the adsorption and photooxidation of ethanol on mixed TiO2--SnO2 photocatalysts.

In situ solid-state NMR methodologies have been used to investigate the photocatalytic oxidation of ethanol (CH3CH2OH) over a series of SnO2-based photocatalysts. The adsorption of ethanol on commercially available SnO2 powder was studied using both cross-polarization 13C NMR and REDOR experiments, and showed the formation of two surface ethanol species, hydrogen-bonded ethanol at surface hydroxyl groups and ethanol chemisorbed to the SnO2 surface (Sn--OCH2CH3). 13C NMR of the adsorbed ethanol was used to characterize the surface of monolayer SnO2--TiO2 coupled photocatalysts supported on porous Vycor glass. In situ solid-state NMR studies showed that the photooxidation of ethanol over the monolayer photocatalysts was slower than that over a supported TiO2 monolayer photocatalyst due to the build-up of reaction intermediates such as acetic acid on the catalyst surface. 119Sn NMR experiments characterized the tin species on the porous Vycor glass support.

Effect of photo-irradiation on hardness of soft lining materials for denture base.

Nine photo-activated acrylic-type (EPL) soft lining materials were produced experimentally to examine their durability. The purpose of this study was to investigate the effect of photo-irradiation on the hardness of experimental soft lining materials. The hardness (Hex) of the nine EPLs was increased 4.3-170.1% by exposing them to light. The effect of irradiation on the Hex of the EPLs was remarkable when the material contained much ethylmethacrylate, together with smaller amounts of di-n-butyl phthalate. Moreover, the Hex tended to increase for EPLs in which the liquid portion contained less di-n-butyl phthalate or more ethanol (Et). The weight change ratio (Wc) was greater for EPL specimens containing less Et. The Wcs ranged from 0.118 to 0.661% after 8 weeks. These results showed that the Hexs of six of the EPLs were approximately equal to those of four commercially available soft lining materials, and these six EPLs may have properties favouring their use in clinical dentistry.

Physical aging by soft ultrasonic wave enhances ethanol metabolism: metabolic process of wine as followed by 400 mhz 1H-NMR spectroscopy.

In natural aging of spirits or wine, the dynamic structure of ethanol-water clusters changes to a smaller and more uniform state. Through experience we know that naturally aged ones have higher metabolism than the non-aged ones. Also, the same effect as natural aging can be obtained in various types of spirits or wines by the treatment for a period of time with soft ultrasonic wave (US). In this study, we compared ethanol metabolism in human subjects dosed with non-treated white wine (control = CON) and with US treated wine. Ethanol levels in human sera were followed by 400 MHz 1H-NMR spectroscopy after administration of wine doses. Experimental results indicated that ethanol metabolism was enhanced 18% in subjects when US treated wine was used rather than when non-treated (CON) was used. Other experiments using rabbits showed that a 20% ethanol-aqueous solution was absorbed 18% more rapidly by the group dosed with US wine than by the CON group. From these experimental facts, it was theorized that ethanol metabolism depends on the rapidity of ethanol absorption in the human body. And it can be concluded that US treatment brings about the same effect on spirits or wines as natural aging.

Dehydroepiandrosterone protects low density lipoproteins against peroxidation by free radicals produced by gamma-radiolysis of ethanol-water mixtures.

Oxidized low density lipoproteins (LDL) are believed to play a central role in the events that initiate atherosclerosis. Antioxidants have been shown to decrease the oxidation of LDL, leading to the diminution of atherosclerosis. Since it is well-known that decreased levels of dehydroepiandrosterone (DHEA) are linked to the development of atherosclerosis, we studied the modulation of the oxidation of LDL by DHEA. LDL were obtained from 10 healthy subjects and oxidized by free radicals produced by gamma-radiolysis of ethanol-water mixtures. The formation of conjugated dienes and thiobarbituric acid-reactive substances (TBARS), the vitamin E content, as well as the incorporation of 4-[14C]DHEA in LDL and the chemotactic effect of oxidized LDL in the presence of DHEA towards monocytes, were investigated. It was found that DHEA was able to inhibit the oxidation of LDL by reducing over 90% of the conjugated dienes and TBARS formation, as well as by reducing the vitamin E disappearance and significantly decreasing the chemotactic activity towards monocytes. Our results suggest that DHEA exerts its antioxidative effect by protecting the endogenous vitamin E of LDL.