Increasing Ethanol Concentration Research Articles

Synergy of Cellulase Systems between Acetivibrio thermocellus and Thermoclostridium stercorarium in Consolidated-Bioprocessing for Cellulosic Ethanol.

Anaerobes harbor some of the most efficient biological machinery for cellulose degradation, especially thermophilic bacteria, such as Acetivibrio thermocellus and Thermoclostridium stercorarium, which play a fundamental role in transferring lignocellulose into ethanol through consolidated bioprocessing (CBP). In this study, we compared activities of two cellulase systems under varying kinds of hemicellulose and cellulose. A. thermocellus was identified to contribute specifically to cellulose hydrolysis, whereas T. stercorarium contributes to hemicellulose hydrolysis. The two systems were assayed in various combinations to assess their synergistic effects using cellulose and corn stover as the substrates. Their maximum synergy degrees on cellulose and corn stover were, respectively, 1.26 and 1.87 at the ratio of 3:2. Furthermore, co-culture of these anaerobes on the mixture of cellulose and xylan increased ethanol concentration from 21.0 to 40.4 mM with a high cellulose/xylan-to-ethanol conversion rate of up to 20.7%, while the conversion rates of T. stercorarium and A. thermocellus monocultures were 19.3% and 15.2%. The reason is that A. thermocellus had the ability to rapidly degrade cellulose while T. stercorarium co-utilized both pentose and hexose, the metabolites of cellulose degradation, to produce ethanol. The synergistic effect of cellulase systems and metabolic pathways in A. thermocellus and T. stercorarium provides a novel strategy for the design, selection, and optimization of ethanol production from cellulosic biomass through CBP.

The Effects of Proline Isomerization on the Solvation Behavior of Elastin-Like Polypeptides in Water-Ethanol Mixtures.

Elastin-like polypeptides (ELPs) are well-known proline-rich stimulus-responsive polymers. They have broad applications ranging from drug delivery to green chemistry. Recently, the authors have shown that the cis/trans proline isomerization can be used to regulate their conformational behavior while keeping the lower critical solution temperature (LCST) unchanged in pure water. In aqueous ethanol mixtures, ELPs typically exhibit an expanded-collapsed-expanded transition known as the co-non-solvency phenomenon. Since it is unclear how proline isomerization affects the solvation behavior of ELPs in aqueous ethanol mixtures, an all-atom insight on single ELPs has been provided to address this question. It is found that if all proline residues are in the cis state, the peptides only experience a collapsed-expanded transition as ethanol concentration increases, i.e., the initial collapse vanishes because cis isomers prefer the compact structures in pure water. The data from the authors also suggest that proline isomerization does not change the shift in solvation free energy of an ELP with given sequence, but it varies the affinity of the peptide to both the solvent and cosolventmolecules.

Micellization and thermodynamics study of n-alkyl-4-methylpyridinium bromides in water and mixed water–ethanol media

The micellization behaviors of n-decyl-4-methylpyridinium bromide, n-dodecyl-4-methylpyridinium bromide, and n-tetradecyl-4-methylpyridinium bromide were studied in water and mixed water–ethanol media by using conductivity measurements over the temperature range of 293.15–318.15 K. The critical micelle concentrations (CMC) of all n-alkyl-4-methyl pyridinium bromides studied increased with increasing temperature, but they decreased with increasing hydrocarbon chain length. Their CMC values of n-decyl-4-methylpyridinium bromide, n-dodecyl-4-methylpyridinium bromide, and n-tetradecyl-4-methylpyridinium bromide in water at the temperature range of 293.15–318.15 K were determined as in the range of 43.62–46.42, 10.45–11.57, and 2.78–3.20 mM, respectively. Moreover, the lowest CMC values of n-decyl-4-methylpyridinium bromide, n-dodecyl-4-methylpyridinium bromide, and n-tetradecyl-4-methylpyridinium bromide were found with 15, 5, and 5 vol% ethanol additions, respectively. The calculated negative ΔGm0 and ΔHm0 values proved that their micellizations in water and mixed water–ethanol media were spontaneous and exothermic. Also, ΔGm0 values became the more negative with the longer the hydrocarbon chain length. Furthermore, their micellization processes in water were determined to be entropy controlled, however enthalpic contributions in the mixed water–ethanol systems started to predominate with increasing ethanol concentrations and/or temperature.

Binary ethanol-water solvents affect betalain contents and health-promoting properties of red Celosia argentea inflorescence extracts

The present work aimed to compare the betalain profiles and contents in the red inflorescence of Celosia argentea extract obtained using different ethanol-water ratios. The impact of betalain content on the health-promoting properties was also evaluated. Freeze-dried inflorescence powder was extracted three times with aqueous-ethanol (0, 20, 40, 60, and 80% (v/v) ethanol). The highest total betacyanin content was found in the 40 and 60% aqueous-ethanolic extracts. Total phenolic content and antioxidant activities of the extracts increased with increasing ethanol concentration. The antioxidant activities measured by oxygen radical absorbance capacity (ORAC) assay of the 60 and 80% aqueous-ethanolic extracts were significantly higher than that of ascorbic acid. The IC50 of α-glucosidase inhibitory activities of all extracts were comparable to that of acarbose. Phenolics were the major responsible compounds for antioxidant (r = 0.975, p < 0.01 by ORAC assay), α-amylase (r = -0.725, p < 0.01), and lipase (r = 0.607, p < 0.05) inhibitory activities, whilst betacyanins corresponded to α-glucosidase inhibitory activities (r = 0.627, p < 0.05). The 60% aqueous-ethanolic extract was superior to the others in terms of colour, phytochemical contents, and health-promoting activities. These extracts can be utilised as natural food colorant, functional ingredients, and nutraceuticals.

Testing antemortem blood samples for ethanol after four to seven years of refrigerated storage.

The previous studies on ethanol stability in antemortem blood samples stored under various conditions have shown that ethanol concentration decreases with storage. The feasibility of measuring a forensically meaningful blood ethanol concentration in antemortem blood samples stored refrigerated (~4°C) from 4-7years after the blood draw was evaluated in this research. All blood samples were collected into two 10-ml gray top Vacutainer® tubes as part of police driving under the influence investigations. In 29 cases, blood in the tube originally analyzed was retested after 5-7years of refrigerated storage. Blood in 41 cases was analyzed in a previously unopened blood tube from the case after 4-7years of refrigerated storage. The first analysis of blood in each case occurred within 35days of the blood draw. Initial blood ethanol concentrations ranged from 0.094g/dl to 0.301g/dl. No samples showed an increase in ethanol concentration with storage that exceeded the uncertainty of the initial measurement. All decreases in ethanol concentration were less than 0.020g/dl. The mean differences in ethanol concentration in previously opened and unopened tubes were -0.014g/dl and -0.010g/dl, respectively. The results of this research support that antemortem blood in previously opened and unopened refrigerated blood tubes can be analyzed for ethanol content more than 4years and as much as 7years after the blood draw and provide a result consistent with the amount of ethanol loss expected from a test done within 1-3years of the blood draw.

Effects of Different Ethanol/Diesel Blending Ratios on Combustion and Emission Characteristics of a Medium-Speed Diesel Engine

In order to better evaluate the effects of ethanol/diesel blends on engine combustion and emission characteristics, we developed an engine cylinder model using the software CONVERGE combined with the program CHEMKIN. The model was validated experimentally. A modified chemical kinetic mechanism was used to calculate the combustion process of diesel fuel and ethanol for the diesel engine, including 154 reactions and 68 species. Furthermore, the influence of different ethanol proportions on diesel engine combustion and emission characteristics, including power, brake specific fuel consumption, brake thermal efficiency, cylinder pressure, cylinder temperature, nitrogen oxide (NOx), carbon monoxide (CO), and soot emissions, was also investigated. Our results showed that cylinder pressure and temperature increased with increased ethanol content. When the ethanol content increased to 20% at 100% load, the cylinder pressure increased by 0.46%, and the thermal efficiency increased by 3.63%. However, due to the lower calorific value of ethanol, the power decreased by 4.12%, and the brake specific fuel consumption increased by 4.23%. In addition, the ethanol/diesel blends significantly reduced CO and soot emissions. Compared with diesel, soot and CO emissions from the D80E20 at 100% load reduced by 63.25% and 17.24%, respectively. However, NOx emission increased by 1.39%.

The spray ignition characteristics of ethanol blended with hydro-processed renewable diesel in a constant volume combustion chamber

In this study, the ignition characteristics of ethanol blended with hydro-processed renewable diesel (HRD) in a constant volume combustion chamber were conducted in both experiments and zero-dimensional (0-D) chemical kinetic simulations. The experimental results revealed that ignition delay (ID) increased with increasing ethanol concentration. The emissions of carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxides (NOx), and hydrocarbon (HC) under lean and stoichiometric conditions were studied at a chamber pressure (Pchamb) of 7 bar. It was found that CO2 emissions reduced with increasing ethanol concentration. However, opposite trend was observed for NOx emissions. Since ethanol has a lower heating value than HRD fuel, the combustion temperature was reduced with the use of the HRD-ethanol blend, which subsequently resulted in lower NOx formation. The addition of ethanol also increased the oxygen concentration which aided in promoting further oxidization of CO to form CO2, thereby reducing the amount of CO produced. Besides, the effect of the addition of ethanol in HRD on HC emission was also observed whereby increasing its ratio increased the oxygen concentration in fuel which had the advantage of reducing HC emission. A kinetic model of 144 species and 600 reactions for the ethanol blended with HRD was also formulated. The kinetic model reasonably reproduced the measured ID periods at initial pressures of 10–20 bar, temperatures of 600–818 K and equivalence ratios of 0.13–0.354, despite quantitative disagreement with the experiment at the lower temperatures. Additionally, the measured trend where the ID periods elongated with respect to the increase in the ethanol concentration was replicated by the kinetic model.

ANALYSIS OF SUBCRITICAL TO SUPERCRITICAL TRANSITION OF N-HEPTANE/ETHANOL BLENDS BY MOLECULAR DYNAMICS SIMULATION

The transcritical transition of the hydrocarbon/alcohol blends from subcritical to supercritical regime has not been yet well understood. In the present paper, based on the molecular dynamics simulation, the non-equilibrium evaporation and transcritical transition processes of the n-heptane/ethanol mixtures are comprehensively investigated under various ambient conditions, and the development of the vapor-liquid interface is deeply analyzed. Under the subcritical condition, with the increased ethanol concentration, the evaporation rate of liquid film is enhanced because of the decreased vapor pressure and increased thermal conductivity. However, under the supercritical condition, due to the comparable thermal conductivity and diffusion rate of ethanol and n-heptane, the effect of ethanol addition on the mixture temperature becomes slight. In addition, at the moderately high pressure, the increased addition of ethanol leads to the broadened vapor-liquid interface, because of the higher volatility and thermal conductivity of ethanol. Since the interfacial thickness affects the interfacial resistivities and evaporation characteristics in the hydrodynamic framework, the gradually thickened interface indicates the more significant non-equilibrium effect in the vicinity of interface for the mixtures with large ethanol addition. Finally, the transcritical transition time is observed to rapidly decrease with the increased ambient pressure, but the descent gradient gradually decreases with the further increased pressure, because the thermal conductivity becomes less sensitive to the pressure.

FEATURES OF THE CONNECTIVE TISSUE COMPONENT OF THE PALATINE TONSILS IN PATIENTS WITH RECURRENT TONSILLITIS.

The aim: To explore the morphological changes of palatine tonsil at the levels of the epithelial layer and connective tissue; to determine the relative area of the connective tissue component in the tonsillar tissue (fibrosis) in patients with recurrent tonsillitis compared to the control. Materials and methods: This study presents a morphological assessment of the palatine tonsils of 10 people. Tonsils' material with surrounding tissue was fixed in 10% formalin solution. The samples were dehydrated in increasing ethanol concentrations, cleared in xylol, impregnated with paraffin. Microscopy was then performed with samples stained beforehand. Results: In the samples of patients with recurrent tonsillitis pericapsular sclerosis was noted, along with thickening of interlobular septa and pronounced subepithelial fibrosis. A ratio of the dense connective tissue surface area to the total surface area of tonsil tissue was determined. The control group showed a statistically significant decrease in the degree of sclerosis of the tonsil stroma. Conclusions: Multiple changes were found in the tonsils of patients with recurrent tonsillitis at the level of the epithelial layer that manifested in structural alterations. Significant and irreversible changes were also observed in the connective stroma of the tonsil - pericapsular sclerosis, thickening of interlobular septa, and pronounced subepithelial fibrosis. A statistically significant increase in the relative surface area of the connective tissue component of the tonsil (fibrosis) by a factor of 1,26 was noted in patients with recurrent tonsillitis compared to the results of the control group of patients.

Insights into the formation of konjac glucomannan gel induced by ethanol equilibration

Alcogels have attracted increasing interest recently in the development of innovative semi-solid alcohol-containing products. The structural and physicochemical properties of konjac glucomannan (KGM) gels equilibrated in different ethanol concentrations were investigated. The swelling ratio of KGM gels increased with increasing KGM concentration and decreased with increasing ethanol concentration. All gels became stronger after ethanol equilibration; this may be due to the KGM chain aggregation when ethanol molecules gathered around KGM and the water molecules were pushed aside from the KGM chain, strengthening the gel. Increasing the ethanol concentration leads to decreased free water availability around the KGM chains and a more hydrophobic environment for KGM, resulting in a large amount of entanglement that facilitates the production of a local or continuous gel network structure, which was shown by the scanning electron microscopy images and low-field nuclear magnetic resonance results. Moreover, the amount of water was decreased, which was based on the peak related to the -OH bond in the KGM structure identified by Fourier transform infrared spectroscopy. The onset thermal decomposition temperatures of KGM gels equilibrated in solutions with various ethanol concentrations were higher than those of the control. The aggregation structures were altered, which was markedly dependent on ethanol concentration, constituting possible evidence of interactions upon equilibration. These results suggest that KGM gels under controlled concentrations of hydrocolloid and ethanol, have promising potential in developing innovative semi-solid alcohol-containing food products.

Phase Transition of n-Heptane/Ethanol Blends from Subcritical to Supercritical Conditions

In this study, the non-equilibrium evaporation and transcritical transition processes of the n-heptane/ethanol blends under the pure nitrogen condition are firstly analyzed, and a new transcritical criterion for the multi-component mixtures is suggested based on the molecular dynamics simulation. Firstly, the employed force fields for the n-heptane/ethanol blends are validated against the measured vapor-liquid equilibrium phase diagram and density. Then, the azeotropic phenomena are captured by the macroscopic distillation experiments for the n-heptane/ethanol blends. The MD simulation reveals that the near-azeotrope can occur in the thermodynamic non-equilibrium period for the 50%EtOH mixture in the nanometer scale, but not for the 12.5/25%EtOH mixtures. Because the lifetime of the small amount of ethanol molecules is smaller than the timescale of thermodynamic equilibrium in the 12.5/25%EtOH mixtures, which suppresses the near-azeotropic occurrence. This indicates that the non-equilibrium has a large effect on the near-azeotropic occurrence possibility. Besides, it is found that the increased ethanol concentration accelerates the evaporation rate of the n-heptane/ethanol blends in nanometer scale at low pressure, but shows little effect under high pressure conditions. Finally, the classical criterion with the large density gradient and little surface tension, is found to be insufficient to identify the transcritical transition. The molecular clusters with various sizes in the vicinity of high-density fluid and the short isothermal period are suggested to couple with the classical phenomenological criterion to determine the transcritical transition.

Effect of ethanol treatment on morphological and technical properties of corn starch

Solvent exchange is considered an effective method that changes the physicochemical properties of starch, especially the absorption. Ethanol concentration is one of the important influencing factors to form porous pores from the surface to inside starch granules. In this study, the effect of ethanol concentration on technical properties of starch treated by solvents were investigated.
 The ratio of ethanol/water was prepared at 1/9, 3/7, 5/5, 7/3 and 10/0 (w/w), respectively. Corn starch was treated by solvent at 8% concentration. Morphology, oil and water holding capacity, solubility, swelling power, viscosity, and transmittance were studied to elucidate the effect of the ethanol concentration on the morphological and technical properties of corn starch treated by solvent. As a result, starch treated by solvent with different concentrations tended to form wrinkles and pore from the surface to the inside of the starch granules during ethanol immersion. Therefore, the oil and water holding capacity, solubility, swelling and viscosity of the solvent-treated starch samples increase as the concentration of ethanol increases. Otherwise, the transmittance of starch glues tends to decrease when the ethanol concentration increases.

3D-Printed Liquid Cell Resonator with Piezoelectric Actuation for In-Line Density-Viscosity Measurements.

The in-line monitoring of liquid properties, such as density and viscosity, is a key process in many industrial areas such as agro-food, automotive or biotechnology, requiring real-time automation, low-cost and miniaturization, while maintaining a level of accuracy and resolution comparable to benchtop instruments. In this paper, 3D-printed cuboid-shaped liquid cells featuring a rectangular vibrating plate in one of the sides, actuated by PZT piezoelectric layers, were designed, fabricated and tested. The device was resonantly excited in the 3rd-order roof tile-shaped vibration mode of the plate and validated as a density-viscosity sensor. Furthermore, conditioning circuits were designed to adapt the impedance of the resonator and to cancel parasitic effects. This allowed us to implement a phase-locked loop-based oscillator circuit whose oscillation frequency and voltage amplitude could be calibrated against density and viscosity of the liquid flowing through the cell. To demonstrate the performance, the sensor was calibrated with a set of artificial model solutions of grape must, representing stages of a wine fermentation process. Our results demonstrate the high potential of the low-cost sensor to detect the decrease in sugar and the increase in ethanol concentrations during a grape must fermentation, with a resolution of 10 µg/mL and 3 µPa·s as upper limits for the density and viscosity, respectively.

Switching Pathways of Triplet State Formation by Twisted Intramolecular Charge Transfer.

With the aim of constructing efficient photoelectric organic materials, a pyrido[3,2-g]quinoline derivative named LA17b has been synthesized, and its photodynamic relaxation processes in solvents and films were studied by time-resolved fluorescence and femtosecond transient absorption techniques. The steady-state fluorescence spectra show pronounced red-shift with the increase of the solvent polarity as well as in binary solvent hexane/ethanol by increasing ethanol concentration. However, the strong red-shift does not lead to quenching of the fluorescence. This is explained in terms of a twisted intramolecular charge transfer (TICT) state. The TICT state of LA17b in ethanol is highly emissive with a long fluorescence lifetime: 1.1 ns. TICT state was shown to play an important role in enhancement of intersystem crossing rate. TD-DFT calculations confirm the pathways of relaxation of locally excited state via TICT and triplet states. In films, the photodynamic properties are similar to that of LA17b in hexane and the TICT state vanishes due to the rigid environment. The obtained optical properties of this molecule suggest that it can be a promising candidate for various optoelectronic applications.

Pectic polysaccharides extracted from sesame seed hull: Physicochemical and functional properties

The objective of the present investigation was to extract pectic polysaccharides from sesame seed hull and to determine their physicochemical and functional characteristics. The pectic polysaccharides in the seed hull were extracted with HCl and then collected at three ethanol concentrations of 30% (SSP30), 50% (SSP50), and 90% (SSP90). We found that SSP30 represented 75.6% of the total polysaccharides, and that it contained 76.39% galacturonic acid, with many HG domains and few short side chains in the RG-I domains. SSP30 exhibited the strongest hydroxyl radical scavenging activity among the three fractions, and was better able to stabilize the emulsions. Higher Mw pectic polysaccharides were firstly precipitated at lower ethanol concentrations, and the Mw of the precipitated pectic polysaccharides decreased with increasing ethanol concentration. These results provide important information on the structure and functional characteristics of sesame hull polysaccharides. This information can contribute to the future development of sesame hull polysaccharides for industrial purposes.

An Experimental and Kinetic Modelling Study on Laminar Premixed Flame Characteristics of Ethanol/Acetone Mixtures

Since both ethanol and acetone are the main components in many alternative fuels, research on the burning characteristics of ethanol-acetone blends is important to understand the combustion phenomena of these alternative fuels. In the present study, the burning characteristics of ethanol-acetone fuel blends are investigated at a temperature of 358 K and pressure of 0.1 MPa with equivalence ratios ranging from 0.7 to 1.4. Ethanol at 100% vol., 25% vol. ethanol/75% vol. acetone, 50% vol. ethanol/50% vol. acetone, 75% vol. ethanol/25% vol. acetone, and 100% vol. acetone are studied by the constant volume combustion chamber (CVCC) method. The results show that the laminar burning velocities of the fuel blends are between that of 100% vol. acetone and 100% vol. ethanol. As the ethanol content increases, the laminar burning velocities of the mixed fuels increase. Furthermore, a detailed chemical kinetic mechanism (AramcoMech 3.0) is used for simulating the burning characteristics of the mixtures. The directed relation graph (DRG), DRG with error propagation (DRGEP), sensitivity analysis (SA), and full species sensitivity analysis (FSSA) are used for mechanism reduction. The flame structure of the skeletal mechanism does not change significantly, and the concentration of each species remains basically the same value after the reaction. The numbers of reactions and species are reduced by 90% compared to the detailed mechanism. Sensitivity and reaction pathway analyses of the burning characteristics of the mixtures indicate that the reaction C2H2+H(+M)<=>C2H3(+M) is the key reaction.

Cellulase Addition and Pre-hydrolysis Effect of High Solid Fed-Batch Simultaneous Saccharification and Ethanol Fermentation from a Combined Pretreated Oil Palm Trunk.

In the current study, alkaline hydrogen peroxide pretreated oil palm trunk fibers were subjected to ethanol production via simultaneous saccharification and fermentation (SSF). The effect of high substrate loading, enzyme and substrate feeding strategy, and influence of a pre-hydrolysis step in SSF was studied to scale up ethanol production. In the enzyme feeding strategy, the addition of an enzyme at the start of fed-batch SSF significantly (p < 0.05) increased ethanol concentration to 51.05 g/L, ethanol productivity (QP) to 0.61 g/L·h, and ethanol yield (YP/S) to 0.31 g/g, with a theoretical ethanol yield of 60.65%. Furthermore, the initial velocity of the enzyme (V0) in the first 8 h was 2.27 (g/h) with a glucose concentration of 18.17 g/L. On the other hand, the substrate feeding strategy and pre-hydrolysis simultaneous saccharification and fermentation (PSSF) process were studied in a 1 L fermenter. PSSF in fed batch with 10 and 20% (w/v) significantly improved enzyme hydrolysis, circumvent the problems of high viscosity, reduced overall fermentation time, and gave the highest ethanol concentration of 51.66 g/L, ethanol productivity (QP) of 0.72 g/L·h, ethanol yield (YP/S) of 0.31 g/g, and theoretical ethanol yield of 60.66%. In addition, PSSF with 10 and 20% significantly increased the initial velocity of the enzyme (V0) to 4.64 and 4.40 (g/h) and glucose concentration to 37.14 and 35.27 g/L, respectively. This result indicated that ethanol production by PSSF along with substrate feeding could enhance ethanol production efficiently.

Maximizing the freeze-dried extract yield by considering the solvent retention index: Extraction kinetics and characterization of Moringa oleifera leaves extracts

A complete chemical characterization of Moringa oleifera leaves was carried out showing a high content of extractives. Extraction kinetics of bioactive compounds present in this fraction were performed by conventional and ultrasound assisted extraction (UAE). A 50% (v/v) hydroalcoholic mixture led to the highest total phenolic compounds yield by conventional solvent extraction, 29.5 ± 0.3 mg per gram of moringa leaves. UAE did not bring any improvement when using hydroalcoholic mixtures probably due to the physical properties of the ethanol aqueous mixtures that affect the UAE performance, such as viscosity and vapor pressure of the mixture. The retention index of the different solvents in the raffinate phase was determined revealing the highest retention index for water, 9.5, and a continuous decrease by increasing ethanol concentration. Retention index is a key parameter in a solvent extraction process since it determines the number of stages in an industrial separation process and it is not usually reported in bioactive compounds extraction. Solvent extraction capacity and the retention index determined the final freeze-dried extract yield.

Volatility and physicochemical properties of gasoline-ethanol blends with gasoline RON-based 88, 90, and 92

A binary set of gasoline-ethanol (GE) blends from three types of gasoline’s research octane number (RON), i.e., RON 88, RON 90, and RON 92, were formulated. Herein, the volatility characteristics, i.e., vapor pressure and distillation behavior were measured. Also, physiochemical properties, i.e., density and RON for each blend and oxygenating compounds influence from ethanol, were discussed. The obtained result revealed that the vapor pressure of GE blends is highly affected by non-ideal vapor-liquid equilibrium mixture. The initial boiling point of GE blends would gradually increase as the higher ethanol’s concentration. However, the final boiling point of the GE blends never exceeds the final boiling point of the pristine gasoline, yet never less than the final boiling point of pristine ethanol. Furthermore, RON, oxygenate content, and density, showed a linear increment curve by increasing ethanol content on each gasoline type. Finally, the results showed that it might be advantageous to use ethanol to provide the added value of gasoline RON 88, RON 90, or RON 92 to form a new gasoline product by considering a confident RON and the limitations for high and low volatility.

Metabolism analysis of 17α-ethynylestradiol by Pseudomonas citronellolis SJTE-3 and identification of the functional genes

Synthetic estrogens are the most hazardous and persistent environmental estrogenic contaminants, with few reports on their biodegradation. Pseudomonas citronellolis SJTE-3 degraded natural steroids efficiently and metabolized 17α-ethynylestradiol (EE2) with the addition of different easily used energy sources (glucose, peptone, ethanol, yeast extract, fulvic acid and ammonia). Over 92% of EE2 (1 mg/L) and 55% of EE2 (10 mg/L) in culture were removed in seven days with the addition of 0.1% ethanol, and the EE2-biotransforming efficiency increased with the increasing ethanol concentrations. Two novel intermediate metabolites of EE2 (C22H22O and C18H34O2) were identified with high-performance liquid chromatography (HPLC) and GC-Orbitrap/MS. Comparative analysis and genome mining revealed strain SJTE-3 contained a unique genetic basis for EE2 metabolism, and the putative EE2-degrading genes exhibited dispersed distribution. The EE2 metabolism of strain SJTE-3 was inducible and the transcription of eight genes were significantly induced by EE2. Three genes (sdr3, yjcH and cyp2) encoding a short-chain dehydrogenase, a membrane transporter and a cytochrome P450 hydroxylase, respectively, were vital for EE2 metabolism in strain SJTE-3; their over-expression accelerated EE2 metabolic processes and advanced the generation of intermediate metabolites. This work could promote the study of bacterial EE2 metabolism mechanisms and facilitate efficient bioremediation for EE2 pollution.