http://www.mdpi.com/section/green_chemistry Related Special Issues in other Journals Sustainable Approaches within the Chemical Sciences in Sustainability http://www.mdpi.com/1422-0067/11/1/233/ Different types of enzymes such as lipases, several phosphatases, dehydrogenases, oxidases, amylases and others are well suited for the reactions in SC-CO2. The stability and the activity of enzymes exposed to carbon dioxide under high pressure depend on enzyme species, water content in the solution and on the pressure and temperature of the reaction system. The three-dimensional structure of enzymes may be significantly altered under extreme conditions, causing their denaturation and consequent loss of activity. If the conditions are less adverse, the protein structure may be largely retained. Minor structural changes may induce an alternative active protein state with altered enzyme activity, specificity and stability. http://www.mdpi.com/1422-0067/11/1/233/ Tue, 19 Jan 2010 00:00:00 CET International Journal of Molecular Sciences 2010-01-19 11 1 Review 233 253 1422-0067 A Review on the Effects of Supercritical Carbon Dioxide on Enzyme Activity 2010-01-19 doi: 10.3390/ijms11010233 Zdenĕk Wimmer Marie Zarevúcka http://www.mdpi.com/1422-0067/11/1/164/ A novel type of high-pressure membrane reactor has been developed for hydrogenation in supercritical carbon dioxide (scCO2). The main objectives of the design of the reactor are the separate feeding of hydrogen and substrate in scCO2 for safe reactions in a continuous flow process, and to reduce the reaction time. By using this new reactor, hydrogenation of cinnamaldehyde into hydrocinnamaldehyde has been successfully carried out with 100% selectivity at 50 °C in 10 MPa (H2: 1 MPa, CO2: 9 MPa) with a flow rate of substrate ranging from 0.05 to 1.0 mL/min. http://www.mdpi.com/1422-0067/11/1/164/ Wed, 13 Jan 2010 00:00:00 CET International Journal of Molecular Sciences 2010-01-13 11 1 Communication 164 172 1422-0067 Development of a Novel Catalytic Membrane Reactor for Heterogeneous Catalysis in Supercritical CO2 2010-01-13 doi: 10.3390/ijms11010164 Nazrul M. Islam Maya Chatterjee Yutaka Ikushima Toshiro Yokoyama Hajime Kawanami http://www.mdpi.com/1422-0067/10/12/5381/ The crystallization and melting behaviors of linear polylactic acid (PLA) treated by compressed CO2 was investigated. The isothermal crystallization test indicated that while PLA exhibited very low crystallization kinetics under atmospheric pressure, CO2 exposure significantly increased PLA’s crystallization rate; a high crystallinity of 16.5% was achieved after CO2 treatment for only 1 min at 100 °C and 6.89 MPa. One melting peak could be found in the DSC curve, and this exhibited a slight dependency on treatment times, temperatures, and pressures. PLA samples tended to foam during the gas release process, and a foaming window as a function of time and temperature was established. Based on the foaming window, crystallinity, and cell morphology, it was found that foaming clearly reduced the needed time for PLA’s crystallization equilibrium. http://www.mdpi.com/1422-0067/10/12/5381/ Wed, 16 Dec 2009 00:00:00 CET International Journal of Molecular Sciences 2009-12-16 10 12 Article 5381 5397 1422-0067 A Study of the Crystallization, Melting, and Foaming Behaviors of Polylactic Acid in Compressed CO2 2009-12-16 doi: 10.3390/ijms10125381 Wentao Zhai Yoorim Ko Wenli Zhu Anson Wong Chul B. Park http://www.mdpi.com/1422-0067/10/12/5285/ The effects of microwave irradiation (2.45 GHz, 200 W) on glycosylation promoted by a solid super acid in supercritical carbon dioxide was investigated with particular attention paid to the structure of the acceptor substrate. Because of the symmetrical structure and high diffusive property of supercritical carbon dioxide, microwave irradiation did not alter the temperature of the reaction solution, but enhanced reaction yield when aliphatic acceptors are employed. Interestingly, the use of a phenolic acceptor under the same reaction conditions did not show these promoting effects due to microwave irradiation. In the case of aliphatic diol acceptors, the yield seemed to be dependent on the symmetrical properties of the acceptors. The results suggest that microwave irradiation do not affect the reactivity of the donor nor promoter independently. We conclude that the effect of acceptor structure on glycosylation yield is due to electric delocalization of hydroxyl group and dielectrically symmetric structure of whole molecule. http://www.mdpi.com/1422-0067/10/12/5285/ Tue, 08 Dec 2009 00:00:00 CET International Journal of Molecular Sciences 2009-12-08 10 12 Article 5285 5295 1422-0067 Microwave Effect for Glycosylation Promoted by Solid Super Acid in Supercritical Carbon Dioxide 2009-12-08 doi: 10.3390/ijms10125285 Hiroshi Hinou Naohiro Saito Masato Ogawa Takahiko Maeda Shin-Ichiro Nishimura http://www.mdpi.com/1422-0067/10/12/5217/ The use of enzymes in supercritical CO2 (SCCO2) has received extensive attention in recent years. Biocatalysts have the advantage of substrate specificity and SCCO2 offers several advantages over liquid solvents. This work deals with the utilization of SCCO2 as a medium for the enzymatic removal of phenol from aqueous solutions using tyrosinase. Since the presence of oxygen is crucial for the enzyme-catalyzed oxidation, the substantial solvating power of SCCO2 makes it a promising medium for such reactions. The conversion of phenol was higher at 10 MPa. Under near critical conditions (7 MPa, 35 ºC), the addition of air at 5 × 105 Pa of pressure improved phenol removal. http://www.mdpi.com/1422-0067/10/12/5217/ Tue, 01 Dec 2009 00:00:00 CET International Journal of Molecular Sciences 2009-12-01 10 12 Article 5217 5223 1422-0067 Enzymatic Reactions in Near Critical CO2: The Effect of Pressure on Phenol Removal by Tyrosinase 2009-12-01 doi: 10.3390/ijms10125217 Priscilla Amaral Daniela Garcia Miguel Cardoso Marisa Mendes Maria Alice Coelho Fernando Pessoa http://www.mdpi.com/1422-0067/10/11/4805/ Sisal leaf decortications residue (SLDR) is amongst the most abundant agroindustrial residues in Tanzania and is a good feedstock for biogas production. Pretreatment of the residue prior to its anaerobic digestion (AD) was investigated using a twostage pre-treatment approach with two fungal strains, CCHT-1 and Trichoderma reesei in succession in anaerobic batch bioreactors. AD of the pre-treated residue with CCTH-1 at 10% (wet weight inoculum/SLDR) inoculum concentration incubated for four days followed by incubation for eight days with 25% (wet weight inoculum/SLDR) of T. reesei gave a methane yield of 0.292 ± 0.04 m3 CH4/kg volatile solids (VS)added. On reversing the pre-treatment succession of the fungal inocula using the same parameters followed by AD, methane yield decreased by about 55%. Generally, an increment in the range of 30–101% in methane yield in comparison to the un-treated SLDR was obtained. The results confirmed the potential of CCHT-1 followed by Trichoderma reesei fungi pre-treatment prior to AD to achieve significant improvement in biogas production from SLDR. http://www.mdpi.com/1422-0067/10/11/4805/ Fri, 06 Nov 2009 00:00:00 CET International Journal of Molecular Sciences 2009-11-06 10 11 Article 4805 4815 1422-0067 Two-Stage Fungal Pre-Treatment for Improved Biogas Production from Sisal Leaf Decortication Residues 2009-11-06 doi: 10.3390/ijms10114805 Mutemi Muthangya Anthony Manoni Mshandete Amelia Kajumulo Kivaisi http://www.mdpi.com/1422-0067/10/11/4623/ Marine biofouling is of major economic concern to all marine industries. The shipping trade is particularly alert to the development of new antifouling (AF) strategies, especially green AF paint as international regulations regarding the environmental impact of the compounds actually incorporated into the formulations are becoming more and more strict. It is also recognised that vessels play an extensive role in invasive species propagation as ballast waters transport potentially threatening larvae. It is then crucial to develop new AF solutions combining advances in marine chemistry and topography, in addition to a knowledge of marine biofoulers, with respect to the marine environment. This review presents the recent research progress made in the field of new non-toxic AF solutions (new microtexturing of surfaces, foul-release coatings, and with a special emphasis on marine natural antifoulants) as well as the perspectives for future research directions. http://www.mdpi.com/1422-0067/10/11/4623/ Tue, 27 Oct 2009 00:00:00 CET International Journal of Molecular Sciences 2009-10-27 10 11 Review 4623 4637 1422-0067 Challenges for the Development of New Non-Toxic Antifouling Solutions 2009-10-27 doi: 10.3390/ijms10114623 Jean-Philippe Maréchal Claire Hellio http://www.mdpi.com/1422-0067/10/10/4515/ The surge of interest in bioenergy has been marked with increasing efforts in research and development to identify new sources of biomass and to incorporate cutting-edge biotechnology to improve efficiency and increase yields. It is evident that various microorganisms will play an integral role in the development of this newly emerging industry, such as yeast for ethanol and Escherichia coli for fine chemical fermentation. However, it appears that microalgae have become the most promising prospect for biomass production due to their ability to grow fast, produce large quantities of lipids, carbohydrates and proteins, thrive in poor quality waters, sequester and recycle carbon dioxide from industrial flue gases and remove pollutants from industrial, agricultural and municipal wastewaters. In an attempt to better understand and manipulate microorganisms for optimum production capacity, many researchers have investigated alternative methods for stimulating their growth and metabolic behavior. One such novel approach is the use of electromagnetic fields for the stimulation of growth and metabolic cascades and controlling biochemical pathways. An effort has been made in this review to consolidate the information on the current status of biostimulation research to enhance microbial growth and metabolism using electromagnetic fields. It summarizes information on the biostimulatory effects on growth and other biological processes to obtain insight regarding factors and dosages that lead to the stimulation and also what kind of processes have been reportedly affected. Diverse mechanistic theories and explanations for biological effects of electromagnetic fields on intra and extracellular environment have been discussed. The foundations of biophysical interactions such as bioelectromagnetic and biophotonic communication and organization within living systems are expounded with special consideration for spatiotemporal aspects of electromagnetic topology, leading to the potential of multipolar electromagnetic systems. The future direction for the use of biostimulation using bioelectromagnetic, biophotonic and electrochemical methods have been proposed for biotechnology industries in general with emphasis on an holistic biofuel system encompassing production of algal biomass, its processing and conversion to biofuel. http://www.mdpi.com/1422-0067/10/10/4515/ Fri, 23 Oct 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-10-23 10 10 Review 4515 4558 1422-0067 Electromagnetic Biostimulation of Living Cultures for Biotechnology, Biofuel and Bioenergy Applications 2009-10-23 doi: 10.3390/ijms10104515 Ryan W. Hunt Andrey Zavalin Ashish Bhatnagar Senthil Chinnasamy Keshav C. Das http://www.mdpi.com/1422-0067/10/7/3235/ When it comes to the marketing of the bioenergy brand, one of the catchiest slogans out these days is “25 by ‘25”. Adopted and supported by industries, academia and government agencies alike, this organization simply aims to supply 25 percent of our energy from renewable resources by the year 2025. By focusing its future efforts on wind, solar and biomass resources, the “25 by 25” initiative is expected to create new jobs, develop novel technologies, help mitigate the effects of global warming and reduce our dependence on fossil fuels. [...] http://www.mdpi.com/1422-0067/10/7/3235/ Wed, 15 Jul 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-07-15 10 7 Editorial 3235 3236 1422-0067 Fuels for Thought! 2009-07-15 doi: 10.3390/ijms10073235 Clifford Louime http://www.mdpi.com/1422-0067/10/7/3209/ Ecological concerns about antifouling paints containing non-green tin and copper compounds have highlighted the need for environmentally friendly alternatives. We report here a field test conducted in estuarine waters over two months designed to evaluate the efficiency of a number of active natural and man-made chemical ingredients added into a silicon-polyurethane marine paint. Early steps of biofouling in cold seawater of the St. Lawrence Estuary (Canada) were observed. Analyses, including dry biomass, flow cytometry and spectrofluorimetry, demonstrated a short-term antibacterial action of chitosan-based paints although no significant anti-algal action was observed. Cuprous oxide paints were efficient against bacteria and algae invasion in the first two weeks, especially those with added organic biocides such as isothiazolone and copper pyrithione. However, the overall dry biomass and chlorophyll a content were similar for all chitosan- and copper-based paints after 63 days. Microscopic observations revealed variation in the highly diverse benthic diatom population including species Navicula, Melosira, Cocconeis, Nitshzcia, Fragilaria and Amphora. Results suggest no real long-term efficiency for tested antifouling paints and highlight a particular need for green antifouling ingredients that are active under northern estuarine conditions. http://www.mdpi.com/1422-0067/10/7/3209/ Tue, 14 Jul 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-07-14 10 7 Article 3209 3223 1422-0067 Biofouling Growth in Cold Estuarine Waters and Evaluation of Some Chitosan and Copper Anti-Fouling Paints 2009-07-14 doi: 10.3390/ijms10073209 Émilien Pelletier Claudie Bonnet Karine Lemarchand http://www.mdpi.com/1422-0067/10/6/2591/ Ionic liquids, considered “green” chemicals, are widely used in many areas of analytical chemistry due to their unique properties. Recently, ionic liquids have been used as a kind of novel additive in separation and combined with silica to synthesize new stationary phase as separation media. This review will focus on the properties and mechanisms of ionic liquids and their potential applications as mobile phase modifier and surface-bonded stationary phase in reversed-phase high performance liquid chromatography (RP-HPLC). Ionic liquids demonstrate advantages and potential in chromatographic field. http://www.mdpi.com/1422-0067/10/6/2591/ Thu, 04 Jun 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-06-04 10 6 Review 2591 2610 1422-0067 Application of Ionic Liquids in High Performance Reversed-Phase Chromatography 2009-06-04 doi: 10.3390/ijms10062591 Ye Wang Minglei Tian Wentao Bi Kyung Ho Row http://www.mdpi.com/1422-0067/10/3/964/ Kinetics of Cr(III) ions transport through a bulk liquid membrane containing dinonylnaphthalenesulfonic acid (DNNSA) as a carrier, flowing over aqueous phases, has been examined. Special attention has been paid to the effect of the membrane’s velocity flow on the chromium concentration decrease in a feed phase. For the description of relationships of chromium(III) concentration in particular phases with the time, a model based on the assumption of consecutive first-order reactions was proposed. Satisfactory compatibility of experiments and model results have been obtained both for the membrane flow velocities below 0.0034 m·s-1 when the interfaces begin to fluctuate slightly and for low initial Cr(III) concentration in the feed phase. http://www.mdpi.com/1422-0067/10/3/964/ Mon, 09 Mar 2009 00:00:00 CET International Journal of Molecular Sciences 2009-03-09 10 3 Article 964 975 1422-0067 Kinetics of Chromium(III) Transport Through a Liquid Membrane Containing DNNSA as a Carrier 2009-03-09 doi: 10.3390/ijms10030964 Paweł Religa Roman Gawroński Paweł Gierycz http://www.mdpi.com/1422-0067/10/2/559/ In marine environments and water systems, it is easy for many structures to form biofilms on their surfaces and to be deteriorated due to the corrosion caused by biofilm formation by bacteria. The authors have investigated the antibacterial effects of metallic elements in practical steels so far to solve food-related problems, using Escherichia coli and Staphylococcus aureus. However, from the viewpoint of material deterioration caused by bacteria and their antifouling measures, we should consider the biofilm behavior as aggregate rather than individual bacterium. Therefore, we picked up Pseudomonas aeruginosa and Pseudoalteromonas carageenovara in this study, since they easily form biofilms in estuarine and marine environments. We investigated what kind of metallic elements could inhibit the biofilm formation at first and then discussed how the thin films of those inhibitory elements on steels could affect biofilm formation. The information would lead to the establishment of effective antifouling measures against corrosion in estuarine and marine environments. http://www.mdpi.com/1422-0067/10/2/559/ Thu, 12 Feb 2009 00:00:00 CET International Journal of Molecular Sciences 2009-02-12 10 2 Article 559 571 1422-0067 Evaluation of Various Metallic Coatings on Steel to Mitigate Biofilm Formation 2009-02-12 doi: 10.3390/ijms10020559 Hideyuki Kanematsu Hajime Ikigai Michiko Yoshitake http://www.mdpi.com/1422-0067/10/2/518/ The growth response of Chlorella vulgaris was studied under varying concentrations of carbon dioxide (ranging from 0.036 to 20%) and temperature (30, 40 and 50oC). The highest chlorophyll concentration (11 µg mL-1) and biomass (210 µg mL-1), which were 60 and 20 times more than that of C. vulgaris at ambient CO2 (0.036%), were recorded at 6% CO2 level. At 16% CO2 level, the concentrations of chlorophyll and biomass values were comparable to those at ambient CO2 but further increases in the CO2 level decreased both of them. Results showed that the optimum temperature for biomass production was 30oC under elevated CO2 (6%). Although increases in temperature above 30oC resulted in concomitant decrease in growth response, their adverse effects were significantly subdued at elevated CO2. There were also differential responses of the alga, assessed in terms of NaH14CO3 uptake and carbonic anhydrase activity, to increases in temperature at elevated CO2. The results indicated that Chlorella vulgaris grew better at elevated CO2 level at 30oC, albeit with lesser efficiencies at higher temperatures. http://www.mdpi.com/1422-0067/10/2/518/ Thu, 05 Feb 2009 00:00:00 CET International Journal of Molecular Sciences 2009-02-05 10 2 Article 518 532 1422-0067 Biomass Production Potential of a Wastewater Alga Chlorella vulgaris ARC 1 under Elevated Levels of CO2 and Temperature 2009-02-05 doi: 10.3390/ijms10020518 Senthil Chinnasamy Balasubramanian Ramakrishnan Ashish Bhatnagar Keshav C. Das http://www.mdpi.com/1422-0067/9/12/2447/ Different plant products have been subjected to detailed investigations due to their increasing importance for improving human health. Plants are sources of many groups of natural products, of which large number of new compounds has already displayed their high impact in human medicine. This review deals with the natural products which may be found dissolved in lipid phase (phytosterols, vitamins etc.). Often subsequent convenient transformation of natural products may further improve the pharmacological properties of new potential medicaments based on natural products. To respect basic principles of sustainable and green procedures, enzymes are often employed as efficient natural catalysts in such plant product transformations. Transformations of lipids and other natural products under the conditions of enzyme catalysis show increasing importance in environmentally safe and sustainable production of pharmacologically important compounds. In this review, attention is focused on lipases, efficient and convenient biocatalysts for the enantio- and regioselective formation / hydrolysis of ester bond in a wide variety of both natural and unnatural substrates, including plant products, eg. plant oils and other natural lipid phase compounds. The application of enzymes for preparation of acylglycerols and transformation of other natural products provides big advantage in comparison with employing of conventional chemical methods: Increased selectivity, higher product purity and quality, energy conservation, elimination of heavy metal catalysts, and sustainability of the employed processes, which are catalyzed by enzymes. Two general procedures are used in the transformation of lipid-like natural products: (a) Hydrolysis/alcoholysis of triacylglycerols and (b) esterification of glycerol. The reactions can be performed under conventional conditions or in supercritical fluids/ionic liquids. Enzyme-catalyzed reactions in supercritical fluids combine the advantages of biocatalysts (substrate specificity under mild reaction conditions) and supercritical fluids (high mass-transfer rate, easy separation of reaction products from the solvent, environmental benefits based on excluding organic solvents from the production process). http://www.mdpi.com/1422-0067/9/12/2447/ Thu, 04 Dec 2008 00:00:00 CET International Journal of Molecular Sciences 2008-12-04 9 12 Review 2447 2473 1422-0067 Plant Products for Pharmacology: Application of Enzymes in Their Transformations 2008-12-04 doi: 10.3390/ijms9122447 Marie Zarevúcka Zdeněk Wimmer http://www.mdpi.com/1422-0067/9/10/1989/ Tributyltin (TBT) released into seawater from ship hulls is a stable marine pollutant and obviously remains in marine environments. We isolated a TBT resistant marine Pseudoalteromonas sp. TBT1 from sediment of a ship’s ballast water. The isolate (109.3 ± 0.2 colony-forming units mL-1) adsorbed TBT in proportion to the concentrations of TBTCl externally added up to 3 mM, where the number of TBT adsorbed by a single cell was estimated to be 108.2. The value was reduced to about one-fifth when the lysozyme-treated cells were used. The surface of ethanol treated cells became rough, but the capacity of TBT adsorption was the same as that for native cells. These results indicate that the function of the cell surface, rather than that structure, plays an important role to the adsorption of TBT. The adsorption state of TBT seems to be multi-layer when the number of more than 106.8 TBT molecules is adsorbed by a single cell. http://www.mdpi.com/1422-0067/9/10/1989/ Fri, 24 Oct 2008 00:00:00 CEST International Journal of Molecular Sciences 2008-10-24 9 10 Article 1989 2002 1422-0067 Accelerator Analysis of Tributyltin Adsorbed onto the Surface of a Tributyltin Resistant Marine Pseudoalteromonas sp. Cell 2008-10-24 doi: 10.3390/ijms9101989 Haruo Mimura Ryusei Sato Yu Sasaki Yuichi Furuyama Akira Taniike Kazutoshi Yoshida Akira Kitamura http://www.mdpi.com/1422-0067/9/9/1665/ In the present work pyrolysis of pure pine wood and softwood carbohydrates, namely cellulose and galactoglucomannan (the major hemicellulose in coniferous wood), was conducted in a batch mode operated fluidized bed reactor. Temperature ramping (5°C/min) was applied to the heating until a reactor temperature of 460 °C was reached. Thereafter the temperature was kept until the release of non-condensable gases stopped. The different raw materials gave significantly different bio-oils. Levoglucosan was the dominant product in the cellulose pyrolysis oil. Acetic acid was found in the highest concentrations in both the galactoglucomannan and in the pine wood pyrolysis oils. Acetic acid is most likely formed by removal of O-acetyl groups from mannose units present in GGM structure. http://www.mdpi.com/1422-0067/9/9/1665/ Tue, 02 Sep 2008 00:00:00 CEST International Journal of Molecular Sciences 2008-09-02 9 9 Article 1665 1675 1422-0067 Pyrolysis of Softwood Carbohydrates in a Fluidized Bed Reactor 2008-09-02 doi: 10.3390/ijms9091665 Atte Aho Narendra Kumar Kari Eränen Bjarne Holmbom Mikko Hupa Tapio Salmi Dmitry Yu. Murzin http://www.mdpi.com/1422-0067/9/9/1621/ Lignocelluloses are often a major or sometimes the sole components of different waste streams from various industries, forestry, agriculture and municipalities. Hydrolysis of these materials is the first step for either digestion to biogas (methane) or fermentation to ethanol. However, enzymatic hydrolysis of lignocelluloses with no pretreatment is usually not so effective because of high stability of the materials to enzymatic or bacterial attacks. The present work is dedicated to reviewing the methods that have been studied for pretreatment of lignocellulosic wastes for conversion to ethanol or biogas. Effective parameters in pretreatment of lignocelluloses, such as crystallinity, accessible surface area, and protection by lignin and hemicellulose are described first. Then, several pretreatment methods are discussed and their effects on improvement in ethanol and/or biogas production are described. They include milling, irradiation, microwave, steam explosion, ammonia fiber explosion (AFEX), supercritical CO2 and its explosion, alkaline hydrolysis, liquid hot-water pretreatment, organosolv processes, wet oxidation, ozonolysis, dilute- and concentrated-acid hydrolyses, and biological pretreatments. http://www.mdpi.com/1422-0067/9/9/1621/ Mon, 01 Sep 2008 00:00:00 CEST International Journal of Molecular Sciences 2008-09-01 9 9 Review 1621 1651 1422-0067 Pretreatment of Lignocellulosic Wastes to Improve Ethanol and Biogas Production: A Review 2008-09-01 doi: 10.3390/ijms9091621 Mohammad J. Taherzadeh Keikhosro Karimi http://www.mdpi.com/1422-0067/9/8/1416/ A controlled fire burner was constructed where various natural vegetation species could be used as fuel. The burner was equipped with thermocouples to measure fuel surface temperature and used as a cavity for microwaves with a laboratory quality 2- port vector network analyzer to determine electrical conductivity from S-parameters. Electrical conductivity for vegetation material flames is important for numerical prediction of flashover in high voltage power transmission faults research. Vegetation fires that burn under high voltage transmission lines reduce flashover voltage by increasing air electrical conductivity and temperature. Analyzer determined electrical conductivity ranged from 0.0058 - 0.0079 mho/m for a fire with a maximum temperature of 1240 K. http://www.mdpi.com/1422-0067/9/8/1416/ Wed, 13 Aug 2008 00:00:00 CEST International Journal of Molecular Sciences 2008-08-13 9 8 Article 1416 1423 1422-0067 Measurement of Electrical Conductivity for a Biomass Fire 2008-08-13 doi: 10.3390/ijms9081416 Kgakgamatso Mphale Mal Heron http://www.mdpi.com/1422-0067/9/8/1393/ Sunflower (Helianthus annuus L.) oil remains under-utilised albeit one of the major seed oils produced world-wide. Moreover, the high oleic sunflower varieties make the oil attractive for applications requiring high temperature processes and those targeting the C=C double bond functionality. Herein an overview of the recent developments in olefin metathesis of sunflower-based feedstocks is presented. The improved performance of olefin metathesis catalysts leading to high turnover numbers, high selectivity and catalyst recyclability, opens new opportunities for tailoring sunflower-based feedstocks into products required for possible new niche market applications. Promising results in biofuel, biopolymers, fragrances and fine chemicals applications have been reported. http://www.mdpi.com/1422-0067/9/8/1393/ Wed, 13 Aug 2008 00:00:00 CEST International Journal of Molecular Sciences 2008-08-13 9 8 Review 1393 1406 1422-0067 Sunflower-based Feedstocks in Nonfood Applications: Perspectives from Olefin Metathesis 2008-08-13 doi: 10.3390/ijms9081393 Bassie B. Marvey http://www.mdpi.com/1422-0067/9/8/1361/ Eucalyptus species are native to Australia but grown extensively worldwide as short rotation hardwoods for a variety of products and as ornamentals. We describe their general importance with specific emphasis on existing and emerging markets as energy products and the potential to maximize their productivity as short rotation woody crops. Using experience in Florida USA and similar locations, we document their current energy applications and assess their productivity as short-term and likely long-term energy and related products. http://www.mdpi.com/1422-0067/9/8/1361/ Wed, 30 Jul 2008 00:00:00 CEST International Journal of Molecular Sciences 2008-07-30 9 8 Article 1361 1378 1422-0067 Energy Product Options for Eucalyptus Species Grown as Short Rotation Woody Crops 2008-07-30 doi: 10.3390/ijms9081361 Donald L. Rockwood Alan W. Rudie Sally A. Ralph J. Y. Zhu Jerrold E. Winandy http://www.mdpi.com/1422-0067/9/7/1342/ Consolidated bioprocessing (CBP) is a system in which cellulase production, substrate hydrolysis, and fermentation are accomplished in a single process step by cellulolytic microorganisms. CBP offers the potential for lower biofuel production costs due to simpler feedstock processing, lower energy inputs, and higher conversion efficiencies than separate hydrolysis and fermentation processes, and is an economically attractive near-term goal for “third generation” biofuel production. In this review article, production of third generation biofuels from cellulosic feedstocks will be addressed in respect to the metabolism of cellulolytic bacteria and the development of strategies to increase biofuel yields through metabolic engineering. http://www.mdpi.com/1422-0067/9/7/1342/ Tue, 22 Jul 2008 00:00:00 CEST International Journal of Molecular Sciences 2008-07-22 9 7 Review 1342 1360 1422-0067 Third Generation Biofuels via Direct Cellulose Fermentation 2008-07-22 doi: 10.3390/ijms9071342 Carlo R. Carere Richard Sparling Nazim Cicek David B. Levin http://www.mdpi.com/1422-0067/9/7/1241/ Technical specifications of solid biofuels are continuously improved towards the development and promotion of their market. Efforts in the Greek market are limited, mainly due to the climate particularity of the region, which hinders the growth of suitable biofuels. Taking also into account the increased oil prices and the high inputs required to grow most annual crops in Greece, cardoon (Cynara cardunculus L.) is now considered the most important and promising sources for solid biofuel production in Greece in the immediate future. The reason is that cardoon is a perennial crop of Mediterranean origin, well adapted to the xerothermic conditions of southern Europe, which can be utilized particularly for solid biofuel production. This is due to its minimum production cost, as this perennial weed may perform high biomass productivity on most soils with modest or without any inputs of irrigation and agrochemicals. Within this framework, the present research work is focused on the planning and analysis of different land use scenarios involving this specific energy crop and the combustion behaviour characterization for the solid products. Such land use scenarios are based on quantitative estimates of the crop’s production potential under specific soil-climatic conditions as well as the inputs required for its realization in comparison to existing conventional crops. Concerning its decomposition behaviour, devolatilisation and char combustion tests were performed in a non-isothermal thermogravimetric analyser (TA Q600). A kinetic analysis was applied and accrued results were compared with data already available for other lignocellulosic materials. The thermogravimetric analysis showed that the decomposition process of cardoon follows the degradation of other lignocellulosic fuels, meeting high burnout rates. This research work concludes that Cynara cardunculus, under certain circumstances, can be used as a solid biofuel of acceptable quality. http://www.mdpi.com/1422-0067/9/7/1241/ Tue, 15 Jul 2008 00:00:00 CEST International Journal of Molecular Sciences 2008-07-15 9 7 Article 1241 1258 1422-0067 Cultivation and Characterization of Cynara Cardunculus for Solid Biofuels Production in the Mediterranean Region 2008-07-15 doi: 10.3390/ijms9071241 Panagiotis Grammelis Anastasia Malliopoulou Panagiotis Basinas Nicholas G. Danalatos http://www.mdpi.com/1422-0067/9/7/1207/ The 1H-NMR shifts of the imidazolium protons of some novel dimeric ionic liquids were examined in various deuterated solvents. Interactions between the solvent and the imidazolium salt of butyl substituted ionic liquids were observed to give higher chemical shifts than methyl substitution. http://www.mdpi.com/1422-0067/9/7/1207/ Mon, 14 Jul 2008 00:00:00 CEST International Journal of Molecular Sciences 2008-07-14 9 7 Article 1207 1213 1422-0067 Synthesis and Characterization of Novel Dimeric Ionic Liquids by Conventional Approaches 2008-07-14 doi: 10.3390/ijms9071207 Kilivelu Ganesan Yatimah Alias http://www.mdpi.com/1422-0067/9/7/1188/ Renewable and carbon neutral biofuels are necessary for environmental and economic sustainability. The viability of the first generation biofuels production is however questionable because of the conflict with food supply. Microalgal biofuels are a viable alternative. The oil productivity of many microalgae exceeds the best producing oil crops. This paper aims to analyze and promote integration approaches for sustainable microalgal biofuel production to meet the energy and environmental needs of the society. The emphasis is on hydrothermal liquefaction technology for direct conversion of algal biomass to liquid fuel. http://www.mdpi.com/1422-0067/9/7/1188/ Wed, 09 Jul 2008 00:00:00 CEST International Journal of Molecular Sciences 2008-07-09 9 7 Review 1188 1195 1422-0067 Towards Sustainable Production of Biofuels from Microalgae 2008-07-09 doi: 10.3390/ijms9071188 Vishwanath Patil Khanh-Quang Tran Hans Ragnar Giselrød http://www.mdpi.com/1422-0067/9/6/1108/ Thermochemical conversion of biomass offers an efficient and economically process to provide gaseous, liquid and solid fuels and prepare chemicals derived from biomass. Computational fluid dynamic (CFD) modeling applications on biomass thermochemical processes help to optimize the design and operation of thermochemical reactors. Recent progression in numerical techniques and computing efficacy has advanced CFD as a widely used approach to provide efficient design solutions in industry. This paper introduces the fundamentals involved in developing a CFD solution. Mathematical equations governing the fluid flow, heat and mass transfer and chemical reactions in thermochemical systems are described and sub-models for individual processes are presented. It provides a review of various applications of CFD in the biomass thermochemical process field. http://www.mdpi.com/1422-0067/9/6/1108/ Fri, 27 Jun 2008 00:00:00 CEST International Journal of Molecular Sciences 2008-06-27 9 6 Review 1108 1130 1422-0067 CFD Studies on Biomass Thermochemical Conversion 2008-06-27 doi: 10.3390/ijms9061108 Yiqun Wang Lifeng Yan http://www.mdpi.com/1422-0067/9/6/1024/ The paper presents a chemical composition analysis of the gases emanated from geothermal sources in the Herculane Spa area (Romania). The upper homologues of methane have been identified in these gases. An ion-molecule reaction mechanism could be implicated in the formation of the upper homologues of methane. The CH4+ ions that appear under the action of radiation are the starting point of these reactions. The presence of hydrogen in the emanated gases may be also a result of these reactions. http://www.mdpi.com/1422-0067/9/6/1024/ Fri, 20 Jun 2008 00:00:00 CEST International Journal of Molecular Sciences 2008-06-20 9 6 Article 1024 1033 1422-0067 Ion-Molecule Reactions and Chemical Composition of Emanated from Herculane Spa Geothermal Sources 2008-06-20 doi: 10.3390/ijms9061024 Constantin Cosma Ioan Suciu Lorentz Jäntschi Sorana D. Bolboacă http://www.mdpi.com/1422-0067/9/5/807/ We report a new one phase method for the synthesis of uniform monodisperse crystalline Ag nanoparticles in aqueous systems that has been developed by using newly synthesized mono and dihydroxylated ionic liquids and cationic surfactants based on 1,3-disubstituted imidazolium cations and halogens anions. The hydroxyl functionalized ionic liquids (HFILs) and hydroxyl functionalized cationic surfactants (HFCSs) also simultaneously acts both as the reductant and protective agent. By changing the carbon chain length, alcohol structure and anion of the 1,3-imidazolium based HFILs and HFCSs the particle size, uniform and dispersibility of nanoparticles in aqueous solvents could be controlled. Transmission electron microscopy (TEM), electron diffraction, UV-Vis and NMR, were used for characterization of HFILs, HFCSs and silver nanoparticles. TEM studies on the solution showed representative spherical silver nanoparticles with average sizes 2-8 nm, particularly 2.2 nm and 4.5 nm in size range and reasonable narrow particle size distributions (SD-standard distribution) 0.2 nm and 0.5 nm respectively. The all metal nanoparticles are single crystals with face centered cubic (fcc) structure. The silver nanoparticles surface of plasmon resonance band (λmax) around 420 nm broadened and little moved to the long wavelength region that indicating the formation of silver nanoparticles dispersion with broad absorption around infrared (IR) region. Silver complexes of these HFILs as well as different silver nanoparticles dispersions have been tested in vitro against several gram positive and gram negative bacteria and fungus. The silver nanoparticles providing environmentally friendly and high antimicrobial activity agents. http://www.mdpi.com/1422-0067/9/5/807/ Tue, 20 May 2008 00:00:00 CEST International Journal of Molecular Sciences 2008-05-20 9 5 Article 807 820 1422-0067 Synthesis of Silver Nanoparticles Using Hydroxyl Functionalized Ionic Liquids and Their Antimicrobial Activity 2008-05-20 doi: 10.3390/ijms9050807 Demberelnyamba Dorjnamjin Maamaa Ariunaa Young Key Shim http://www.mdpi.com/1422-0067/9/5/768/ The lignocellulose in forage crops represents a second generation of biomass feedstock for conversion into energy-related end products. Some of the most extensively studied species for cellulosic feedstock production include forages such as switchgrass (Panicum virgatum L.), reed canarygrass (Phalaris arundinacea L.), and alfalfa (Medicago sativa L.). An advantage of using forages as bioenergy crops is that farmers are familiar with their management and already have the capacity to grow, harvest, store, and transport them. Forage crops offer additional flexibility in management because they can be used for biomass or forage and the land can be returned to other uses or put into crop rotation. Estimates indicate about 22.3 million ha of cropland, idle cropland, and cropland pasture will be needed for biomass production in 2030. Converting these lands to large scale cellulosic energy farming could push the traditional forage-livestock industry to ever more marginal lands. Furthermore, encouraging bioenergy production from marginal lands could directly compete with forage-livestock production. http://www.mdpi.com/1422-0067/9/5/768/ Tue, 20 May 2008 00:00:00 CEST International Journal of Molecular Sciences 2008-05-20 9 5 Review 768 788 1422-0067 Perennial Forages as Second Generation Bioenergy Crops 2008-05-20 doi: 10.3390/ijms9050768 Matt A. Sanderson Paul R. Adler http://www.mdpi.com/1422-0067/9/5/838/ Bioenergy is fairly recognized as not only a necessity, but an inevitable path to secure the planet future energy needs. There is however a global consensus that the overall feasibility of bioenergy will require an integrated approach based on diversified feedstocks and conversion processes. As illustrated in the Brazilian experience, the thrust of any bioenergy program should be centered on the principles and criteria of sustainable production. In general the trends are towards exploiting low value cellulosic materials to obtain high-end value energy products. To this end, it is expected that scientific or technical innovation will come to play a critical role on the future prospects and potential of any bioenergy initiative. http://www.mdpi.com/1422-0067/9/5/838/ Sat, 17 May 2008 00:00:00 CEST International Journal of Molecular Sciences 2008-05-17 9 5 Editorial 838 841 1422-0067 Cellulosic Ethanol: Securing the Planet Future Energy Needs 2008-05-17 doi: 10.3390/ijms9050838 Clifford Louime Hannah Uckelmann http://www.mdpi.com/1422-0067/9/4/615/ The complexes RuCl2(PCy3)2(=CHPh), 1, and RuCl2(PCy3)(H2IMes)(=CHPh), 2, proved to be active catalysts for the self-metathesis of oleate-type fatty compounds containing the ester, hydroxyl, epoxy and carboxylic acid functional groups. At elevated reaction temperatures 2 showed a higher activity, stability and lower selectivity for primary metathesis products compared to 1. A profound influence of organic functional groups on catalyst activity and selectivity was found and from relative activities and selectivities 2 has proved to be more resistant to deactivation by polar functional groups and more inclined to promote double bond isomerisation than 1. The observed catalyst deactivation by oxygen-containing functional groups could be attributed to a phosphine displacement side reaction. http://www.mdpi.com/1422-0067/9/4/615/ Fri, 18 Apr 2008 00:00:00 CEST International Journal of Molecular Sciences 2008-04-18 9 4 Article 615 625 1422-0067 Ruthenium Carbene Mediated Metathesis of Oleate-Type Fatty Compounds 2008-04-18 doi: 10.3390/ijms9040615 Bassie B. Marvey Constance K. Segakweng Manie H. C. Vosloo http://www.mdpi.com/1422-0067/9/4/542/ A model experiment monitoring the fate of total residue oxidant (TRO) in water at a constant temperature and salinity indicated that it decayed exponentially with time, and with TRO decaying faster in seawater than in distilled water. The reduction of TRO by temperature (°K) was found to fit a curvilinear relationship in distilled water (r2 = 0.997) and a linear relationship in seawater (r2 = 0.996). Based on the decay rate, flow rate, and the length of cooling water flowing through at a given temperature, the TRO level in the cooling water of a power plant could be estimated using the equation developed in this study. This predictive model would provide a benchmark for power plant operators to adjust the addition of chlorine to levels necessary to control bio-fouling of cooling water intake pipelines, but without irritating ambient marine organisms. http://www.mdpi.com/1422-0067/9/4/542/ Fri, 04 Apr 2008 00:00:00 CEST International Journal of Molecular Sciences 2008-04-04 9 4 Article 542 553 1422-0067 A Model to Predict Total Chlorine Residue in the Cooling Seawater of a Power Plant Using Iodine Colorimetric Method 2008-04-04 doi: 10.3390/ijms9040542 Jih-Terng Wang Ming-Hui Chen Hung-Jen Lee Wen-Been Chang Chung-Chi Chen Su-Cheng Pai Pei-Jie Meng http://www.mdpi.com/1422-0067/9/4/512/ The Thermogravimetric Analysis (TGA) techniques and concretely the study of the burning profile provide information that can be used to estimate the behaviour of the combustion of carbonous materials. Commonly, these techniques have been used for the study of carbons, but are also interesting for the analysis of biomass wastes, due to the different species present on the wastes affect directly to its thermal properties. In this work, techniques of thermal analysis have been applied to compare the behaviour of different wastes coming from olive oil mills. From these results, it is remarkable that the Concentrated Olive Mill Waste Water (COMWW) presents more unfavourable conditions for its combustion. http://www.mdpi.com/1422-0067/9/4/512/ Fri, 04 Apr 2008 00:00:00 CEST International Journal of Molecular Sciences 2008-04-04 9 4 Article 512 525 1422-0067 Combustion Analysis of Different Olive Residues 2008-04-04 doi: 10.3390/ijms9040512 Teresa Miranda Alberto Esteban Sebastián Rojas Irene Montero Antonio Ruiz http://www.mdpi.com/1422-0067/9/4/498/ Quartz crystal microbalance with dissipation (QCM-D) monitoring and atomic force microscopy (AFM) were combined to evaluate the defects created by an ionic liquid anion and a cation in a supported phospholipid bilayer composed of zwitterionic lipids on a silica surface. The cation 1-octyl-3-methyl imidazolium (OMIM+) was shown to remove lipids from the bilayer, increase the roughness to approximately 2.8 nm (~0.2 for stable supported bilayer) and possibly redeposit lipids with entrapped water. The anion bis(trifluoromethylsulfonyl)imide (Tf2N-) was found to leave distinct defects within the bilayer that had large pore-like interiors which left the surrounding bilayer intact. However, the ionic liquid 1-butyl-1-methyl pyrrolidinium bis(trifluoromethylsulfonyl)imide (BMP-Tf2N) formed a film over the supported bilayer. This work demonstrates, for the first time, the direct effects common components of ionic liquids have on a supported phospholipids bilayer. http://www.mdpi.com/1422-0067/9/4/498/ Fri, 04 Apr 2008 00:00:00 CEST International Journal of Molecular Sciences 2008-04-04 9 4 Article 498 511 1422-0067 Supported Phospholipid Bilayer Interaction with Components Found in Typical Room-Temperature Ionic Liquids – a QCM-D and AFM Study 2008-04-04 doi: 10.3390/ijms9040498 Kervin O. Evans http://www.mdpi.com/1422-0067/9/3/342/ Techniques in resin blending are simple and efficient method for improving the properties of polymers, and have been used widely in polymer modification field. However, polymer latex blends such as the combination of latexes, especially the latexes with water-soluble polymers, were rarely reported. Here, we report a core-shell composite latex synthesized using methyl methacrylate (MMA), butyl acrylate (BA), 2-ethylhexyl acrylate (EHA) and glycidyl methacrylate (GMA) as monomers and ammonium persulfate and sodium bisulfite redox system as the initiator. Two stages seeded semi-continuous emulsion polymerization were employed for constructing a core-shell structure with P(MMA-co-BA) component as the core and P(EHA-co-GMA) component as the shell. Results of Transmission Electron Microscopy (TEM) and Dynamics Light Scattering (DLS) tests confirmed that the particles obtained are indeed possessing a desired core-shell structural character. Stable reactive latex blends were prepared by adding the latex with waterborne melamine-formaldehyde resin (MF) or urea-formaldehyde resin (UF). It was found that the glass transition temperature, the mechanical strength and the hygroscopic property of films cast from the latex blends present marked enhancements under higher thermal treatment temperature. It was revealed that the physical properties of chemically reactive latexes with core-shell structure could be altered via the change of crosslinking density both from the addition of crosslinkers and the thermal treatment. http://www.mdpi.com/1422-0067/9/3/342/ Wed, 12 Mar 2008 00:00:00 CET International Journal of Molecular Sciences 2008-03-12 9 3 Article 342 354 1422-0067 Synthesis and Characterization of Core-Shell Acrylate Based Latex and Study of Its Reactive Blends 2008-03-12 doi: 10.3390/ijms9030342 Xiang Liu Xiao-Dong Fan Min-Feng Tang Ying Nie http://www.mdpi.com/1422-0067/9/3/247/ The soil microorganism Myxobacter Sp. AL-1 regulates in a differential manner the production of five extracellular cellulases during its life cycle. The nucleotide sequence of a cel9-cel48 cluster from the genome of this microorganism was recently obtained. Cel48 was expressed in Escherichia coli to generate a His6-Cel48 protein and the biochemical properties of the pure protein were determined. Cel48 was more efficient in degrading acid-swollen avicel (ASC) than carboxymethylcellulose (CMC). On the other hand, cel9 was expressed in Bacillus subtilis from an IPTG-inducible promoter. Zymogram analysis showed that after IPTG-induction, Cel9 existed in both the cell fraction and the culture medium of B. subtilis and the secreted protein was purified to homogeneity by FPLC-ionic exchange chromatography. The exocellobiohydrolase Cel48 showed a synergism of 1.68 times with the endocellulase Cel9 during ASC degradation using an 8.1- fold excess of Cel48 over Cel9. Western blot analysis revealed that both proteins were synthesized and secreted to the culture medium of Myxobacter Sp. AL-1. These results show that the cel9-cel48 cluster encodes functional endo- and exo-acting cellulases that allows Myobacter Sp. AL-1 to hydrolyse cellulose. http://www.mdpi.com/1422-0067/9/3/247/ Fri, 29 Feb 2008 00:00:00 CET International Journal of Molecular Sciences 2008-02-29 9 3 Editorial 247 257 1422-0067 Expression, Characterization and Synergistic Interactions of Myxobacter Sp. AL-1 Cel9 and Cel48 Glycosyl Hydrolases 2008-02-29 doi: 10.3390/ijms9030247 Norma Ramírez-Ramírez Eliel R. Romero-García Vianney C. Calderón Claudia I. Avitia Alfredo Téllez-Valencia Mario Pedraza-Reyes http://www.mdpi.com/1422-0067/9/2/169/ Due to the concern on the availability of recoverable fossil fuel reserves and the environmental problems caused by the use those fossil fuels, considerable attention has been given to biodiesel production as an alternative to petrodiesel. However, as the biodiesel is produced from vegetable oils and animal fats, there are concerns that biodiesel feedstock may compete with food supply in the long-term. Hence, the recent focus is to find oil bearing plants that produce non-edible oils as the feedstock for biodiesel production. In this paper, two plant species, soapnut (Sapindus mukorossi) and jatropha (jatropha curcas, L.) are discussed as newer sources of oil for biodiesel production. Experimental analysis showed that both oils have great potential to be used as feedstock for biodiesel production. Fatty acid methyl ester (FAME) from cold pressed soapnut seed oil was envisaged as biodiesel source for the first time. Soapnut oil was found to have average of 9.1% free FA, 84.43% triglycerides, 4.88% sterol and 1.59% others. Jatropha oil contains approximately 14% free FA, approximately 5% higher than soapnut oil. Soapnut oil biodiesel contains approximately 85% unsaturated FA while jatropha oil biodiesel was found to have approximately 80% unsaturated FA. Oleic acid was found to be the dominant FA in both soapnut and jatropha biodiesel. Over 97% conversion to FAME was achieved for both soapnut and jatropha oil. http://www.mdpi.com/1422-0067/9/2/169/ Fri, 08 Feb 2008 00:00:00 CET International Journal of Molecular Sciences 2008-02-08 9 2 Article 169 180 1422-0067 Non-Edible Plant Oils as New Sources for Biodiesel Production 2008-02-08 doi: 10.3390/ijms9020169 Arjun B. Chhetri Martin S. Tango Suzanne M. Budge K. Chris Watts M. Rafiqul Islam http://www.mdpi.com/1422-0067/9/1/33/ Inspired by the concept of ionic liquids (ILs), this study modified the original Mukaiyama’s reagent, 2-chloro-1-methylpyridinium iodide (m.p. 200-dec), from ionic solid into liquids by changing its anion. The esterification of N-acetyl-L-phenylalanine was investigated as a model reaction. The microwave irradiation was more effective in esterifying N-acetyl-L-phenylalanine than the conventional reflux method. The original Mukaiyama’s reagent was modified into ILs through manipulating its anion. However, only non-nucleophilic anions (such as EtSO4- and Tf2N-) were favorable since nucleophilic ones (such as CF3COO- and CH3COO-) could exchange with chlorine resulting in non-reactive coupling reagents. Two modified Mukaiyama’s compounds (i.e. hydrophilic [2- ClMePy][EtSO4] and hydrophobic [2-ClMePy][Tf2N]) have been identified as the best ILtype coupling reagents. The esterification reaction was greatly enhanced by using 1- methylimidazole as the base instead of conventional toxic tertiary amines, and by using excess amount of alcohols as solvents instead of dichloromethane. Overall, the method reported is effective and ‘greener’. http://www.mdpi.com/1422-0067/9/1/33/ Wed, 16 Jan 2008 00:00:00 CET International Journal of Molecular Sciences 2008-01-16 9 1 Article 33 44 1422-0067 Microwave-Assisted Esterification of N-Acetyl-L-Phenylalanine Using Modified Mukaiyama’s Reagents: A New Approach Involving Ionic Liquids 2008-01-16 doi: 10.3390/ijms9010033 Hua Zhao Zhiyan Song Janet V. Cowins Olarongbe Olubajo http://www.mdpi.com/1422-0067/8/9/920/ The cultivation of toxic lignocellulosic hydrolyzates has become a challengingresearch topic in recent decades. Although several cultivation methods have been proposed,numerous questions have arisen regarding their industrial applications. The current workdeals with a solution to this problem which has a good potential application on anindustrial scale. A toxic dilute-acid hydrolyzate was continuously cultivated using a high-cell-density flocculating yeast in a single and serial bioreactor which was equipped with asettler to recycle the cells back to the bioreactors. No prior detoxification was necessary tocultivate the hydrolyzates, as the flocks were able to detoxify it in situ. The experimentswere successfully carried out at dilution rates up to 0.52 h-1. The cell concentration insidethe bioreactors was between 23 and 35 g-DW/L, while the concentration in the effluent ofthe settlers was 0.32 ± 0.05 g-DW/L. An ethanol yield of 0.42-0.46 g/g-consumed sugarwas achieved, and the residual sugar concentration was less than 6% of the initialfermentable sugar (glucose, galactose and mannose) of 35.2 g/L. http://www.mdpi.com/1422-0067/8/9/920/ Mon, 03 Sep 2007 00:00:00 CEST International Journal of Molecular Sciences 2007-09-03 8 9 Article 920 932 1422-0067 A Possible Industrial Solution to Ferment Lignocellulosic Hydrolyzate to Ethanol: Continuous Cultivation with Flocculating Yeast 2007-09-03 doi: 10.3390/i8090920 Ronny Purwadi Tomas Brandberg Mohammad J. Taherzadeh http://www.mdpi.com/1422-0067/8/8/842/ Within the recently launched the spectral-structure activity relationship (S-SAR)analysis, the vectorial anionic-cationic model of a generic ionic liquid is proposed, alongwith the associated algebraic correlation factor in terms of the measured and predictedactivity norms. The reliability of the present scheme is tested by assessing the Hanschfactors, i.e. lipophylicity, polarizability and total energy, to predict the ecotoxicityendpoints of wide types of ionic liquids with ammonium, pyridinium, phosphonium,choline and imidazolium cations on the aquatic bacteria Vibrio fischeri. The results, whileconfirming the cationic dominant influence when only lipophylicity is considered,demonstrate that the anionic effect dominates all other more specific interactions. It wasalso proved that the S-SAR vectorial model predicts considerably higher activity for theionic liquids than for its anionic and cationic subsystems separately, in all consideredcases. Moreover, through applying the least norm-correlation path principle, the completetoxicological hierarchies are presented, unfolding the ecological rules of combined cationicand anionic influences in ionic liquid toxicity. http://www.mdpi.com/1422-0067/8/8/842/ Thu, 23 Aug 2007 00:00:00 CEST International Journal of Molecular Sciences 2007-08-23 8 8 Article 842 863 1422-0067 A Spectral-SAR Model for the Anionic-Cationic Interaction in Ionic Liquids: Application to Vibrio fischeri Ecotoxicity 2007-08-23 doi: 10.3390/i8080842 Ana-Maria Lacrămă Mihai V. Putz Vasile Ostafe http://www.mdpi.com/1422-0067/8/8/777/ This work deals with the application of encapsulation technology to eliminateinhibition by D-limonene in fermentation of orange wastes to ethanol. Orange peel wasenzymatically hydrolyzed with cellulase and pectinase. However, fermentation of thereleased sugars in this hydrolyzate by freely suspended S. cerevisiae failed due to inhibitionby limonene. On the other hand, encapsulation of S. cerevisiae in alginate membranes wasa powerful tool to overcome the negative effects of limonene. The encapsulated cells wereable to ferment the orange peel hydrolyzate in 7 h, and produce ethanol with a yield of 0.44g/g fermentable sugars. Cultivation of the encapsulated yeast in defined medium wassuccessful, even in the presence of 1.5% (v/v) limonene. The capsules’ membranes wereselectively permeable to the sugars and the other nutrients, but not limonene. While1% (v/v) limonene was present in the culture, its concentration inside the capsules was notmore than 0.054% (v/v). http://www.mdpi.com/1422-0067/8/8/777/ Tue, 07 Aug 2007 00:00:00 CEST International Journal of Molecular Sciences 2007-08-07 8 8 Article 777 787 1422-0067 Protective Effect of Encapsulation in Fermentation of Limonene-contained Media and Orange Peel Hydrolyzate 2007-08-07 doi: 10.3390/i8080777 Mohammad Pourbafrani Farid Talebnia Claes Niklasson Mohammad J. Taherzadeh http://www.mdpi.com/1422-0067/8/8/749/ Hydroformylation of cyclohexene was studied with a catalyst system ofRu3(CO)12 and LiCl using H2 and CO2 instead of CO in NMP. The influence of H2 andCO2 pressures on the total conversion and the product distribution was examined. It wasshown that increasing total pressure of H2 and CO2 promoted the reverse water gas shiftreaction and increased the yield of cyclohexanecarboxaldehyde. Its hydrogenation tocyclohexanemethanol was promoted with increasing H2 pressure but suppressed withincreasing CO2 pressure. Cyclohexane was also formed along with those products and thisdirect hydrogenation was suppressed with increasing CO2 pressure. The roles of CO2 as apromoter as well as a reactant were further examined by phase behavior observations andhigh pressure FTIR measurements. http://www.mdpi.com/1422-0067/8/8/749/ Thu, 02 Aug 2007 00:00:00 CEST International Journal of Molecular Sciences 2007-08-02 8 8 Article 749 759 1422-0067 Hydroformylation of Cyclohexene with Carbon Dioxide and Hydrogen Using Ruthenium Carbonyl Catalyst: Influence of Pressures of Gaseous Components 2007-08-02 doi: 10.3390/i8080749 Shin-ichiro Fujita Shuhei Okamura Yoshinari Akiyama Masahiko Arai http://www.mdpi.com/1422-0067/8/8/736/ The salting-out effect produced by the addition of potassium phosphate, K3PO4to aqueous solutions of water-miscible ionic liquids, viz. 1-ethyl-3-methylimidazoliumethyl sulfate, 1-butyl-3-methylimidazolium methyl sulfate, or 1-alkyl-3-methylimidazolium chloride (alkyl = butyl, octyl or decyl) is investigated. The effects areanalyzed using both the corresponding temperature–composition pseudo-binary andcomposition ternary phase diagrams. Different regions of liquid-liquid and solid-liquidphase demixing are mapped. The phase behavior is interpreted taking into account thecomplex and competing nature of the interactions between the ionic liquid, the inorganicsalt and water. In the case of solutions containing 1-octyl- or 1-decyl-3-methylimidazoliumchloride, the smaller magnitude of the salting-out effects is explained in terms of thepossibility of self-aggregation of the ionic liquid. http://www.mdpi.com/1422-0067/8/8/736/ Tue, 31 Jul 2007 00:00:00 CEST International Journal of Molecular Sciences 2007-07-31 8 8 Article 736 748 1422-0067 Salting-out in Aqueous Solutions of Ionic Liquids and K3PO4: Aqueous Biphasic Systems and Salt Precipitation 2007-07-31 doi: 10.3390/i8080736 Vesna Najdanovic-Visak José N. Canongia Lopes Zoran P. Visak J. Trindade Luís P. N. Rebelo http://www.mdpi.com/1422-0067/8/7/680/ A process to produce fibers from Poly(m-phenyleneisophthalamide)(PMIA)solution in an ionic liquid via wet-spinning technology are described. The spinning processwas investigated on a small laboratory scale. Ionic liquid spinning solutions were firstprepared for PMIA fibers, followed by wet spinning. In the course of this research, thephysical properties of the PMIA fibers were estimated. We studied the dependence of themechanical properties of the obtained PMIA fibers on the composition of the coagulationbath, and on the choice of solvent in spinning solution. The morphology of the fibers fromionic liquid and traditional DMAc solvents via wet-spinning process were observed byscanning electrical microscopy(SEM). The differences of morphologies and properties ofthe PMIA fibers obtained from two different solvents are discussed. http://www.mdpi.com/1422-0067/8/7/680/ Tue, 17 Jul 2007 00:00:00 CEST International Journal of Molecular Sciences 2007-07-17 8 7 Article 680 685 1422-0067 The Preparation and Characterization of Poly(m-phenylene- isophthalamide) Fibers Using Ionic Liquids 2007-07-17 doi: 10.3390/i8070680 Tingting Zhao Huaping Wang Yumei Zhang Biao Wang Jianming Jiang http://www.mdpi.com/1422-0067/8/7/628/ The ring hydrogenation of benzoic acid to cyclohexanecarboxylic acid overcharcoal-supported transition metal catalysts in supercritical CO2 medium has been studiedin the present work. The cyclohexanecarboxylic acid can be produced efficiently insupercritical CO2 at the low reaction temperature of 323 K. The presence of CO2 increasesthe reaction rate and several parameters have been discussed. http://www.mdpi.com/1422-0067/8/7/628/ Thu, 12 Jul 2007 00:00:00 CEST International Journal of Molecular Sciences 2007-07-12 8 7 Article 628 634 1422-0067 Catalytic Ring Hydrogenation of Benzoic Acid with Supported Transition Metal Catalysts in scCO2 2007-07-12 doi: 10.3390/i8070628 Hongjun Wang Fengyu Zhao http://www.mdpi.com/1422-0067/8/7/593/ The liquid-liquid equilibrium for the ternary system formed by n-octane andaromatic (alkylbenzenes) and heteroaromatic compounds (nitrogen and sulfur containingheterocyles) and 1-alkyl-3-methylimidazolium ionic liquids (ILs) associated with variousanions has been investigated. The selectivity on the extraction of a specific aromaticcompound is influenced by anion volume, hydrogen bond strength between the anion andthe imidazolium cation and the length of the 1-methyl-3-alkylimidazolium alkyl side chain.The interaction of alkylbenzenes and sulfur heterocyles with the IL is preferentially throughCH-π hydrogen bonds and the quantity of these aromatics in the IL phase decreases withthe increase of the steric hindrance imposed by the substituents on the aromatic nucleus. Inthe case of nitrogen heterocycles the interaction occurs preferentially throughN(heteroaromatic)-H(imidazolium) hydrogen bonds and the extraction process is largelycontrolled by the nitrogen heterocycle pKa. Competitive extraction experiments suggestthat benzene, pyridine and dibenzothiophene do not compete for the same hydrogen bondsites of the IL. http://www.mdpi.com/1422-0067/8/7/593/ Mon, 02 Jul 2007 00:00:00 CEST International Journal of Molecular Sciences 2007-07-02 8 7 Article 593 605 1422-0067 On the Extraction of Aromatic Compounds from Hydrocarbons by Imidazolium Ionic Liquids 2007-07-02 doi: 10.3390/i8070593 Cláudia C. Cassol Alexandre P. Umpierre Günter Ebeling Bauer Ferrera Sandra S. X. Chiaro Jairton Dupont http://www.mdpi.com/1422-0067/8/6/553/ The room temperature ionic liquid [bmim][PF6] was employed as the reactionmedium in the asymmetric glyoxylate-ene reaction of α-methyl styrene (4a) with ethylglyoxylate using chiral palladium(II) complexes as the catalysts. [Pd(S-BINAP)(3,5-CF3-PhCN)2](SbF6)2 (1b) showed the highest catalytic activity. Under the reaction conditionsof 40 oC, 0.5 h, and 1b/4a molar ratio of 0.05, ethyl α-hydroxy-4-phenyl-4-pentenoate wasobtained in excellent chemical yield (94 %) with high enantioselectivity (70 %). Otherα-hydroxy esters can also be obtained in high chemical yields and enantioselectitiesthrough the glyoxylate-ene reactions of alkenes with glyoxylates catalyzed by 1b in[bmim][PF6]. Moreover, the ionic liquid [bmim][PF6] which contained the palladium(II)complex could be recycled and reused several times without significant loss of the catalyticactivity. http://www.mdpi.com/1422-0067/8/6/553/ Fri, 22 Jun 2007 00:00:00 CEST International Journal of Molecular Sciences 2007-06-22 8 6 Article 553 563 1422-0067 Asymmetric Glyoxylate-Ene Reactions Catalyzed by Chiral Pd(II) Complexes in the Ionic Liquid [bmim][PF6] 2007-06-22 doi: 10.3390/i8060553 Xi Jun He Zhen Lu Shen Wei Min Mo Bao Xiang Hu Nan Sun http://www.mdpi.com/1422-0067/8/6/505/ The selective oxidation of alcohols with molecular oxygen was efficientlycompleted in high conversion and selectivity using copper-bisisoquinoline-based catalystsunder mild reaction condition. The effects of various parameters such as reactiontemperature, reaction time, oxidant, ligands, etc, were studied. Solvent effect has been aswell studied in ionic liquids [bmim]PF6, [omim]BF4 and [hmim]BF4, comparing totraditional volatile organic solvent. The use of ionic liquids was found to enhance thecatalytic properties of the catalysts used. http://www.mdpi.com/1422-0067/8/6/505/ Wed, 06 Jun 2007 00:00:00 CEST International Journal of Molecular Sciences 2007-06-06 8 6 Article 505 512 1422-0067 Efficient Copper-bisisoquinoline-based Catalysts for Selective Aerobic Oxidation of Alcohols to Aldehydes and Ketones 2007-06-06 doi: 10.3390/i8060505 Hao-Yu Shen Li-Yan Ying Hai-Liang Jiang Zaher M. A. Judeh http://www.mdpi.com/1422-0067/8/6/470/ Hydrolysis of the ionic liquid Et3NHCl-2AlCl3 and a process for recycling thetriethylamine were studied. When the hydrolysis was carried out at a relatively hightemperature, the released HCl could be absorbed more easily. With addition of sodiumhydroxide to the aqueous hydrolysis solution, a feasible process for recycling triethylaminewas developed, involving first distillation of triethylamine, followed by filtration of thealuminium hydroxide. The yield of recovered triethylamine was about 95%. Thetriethylhydrogenammonium chloride prepared from the recycled triethylamine was of goodpurity and could be reused to synthesize new chloroaluminate ionic liquids. http://www.mdpi.com/1422-0067/8/6/470/ Mon, 04 Jun 2007 00:00:00 CEST International Journal of Molecular Sciences 2007-06-04 8 6 Article 470 477 1422-0067 Hydrolysis and Partial Recycling of a Chloroaluminate Ionic Liquid 2007-06-04 doi: 10.3390/i8060470 Ming-Hong Fang Li-Sheng Wang http://www.mdpi.com/1422-0067/8/5/392/ The combinations of 1-butyl-3-methylimidazolium chloride with NbCl5 yieldedionic mixtures with different melting point temperatures and acidity depending on theniobium molar fraction. The mixtures were characterized by thermal (DSC) andspectroscopic (FT-IR and 1H NMR) analysis. The Pechmann reactions of different phenolswith ethylacetoacetate, producing coumarins, was used as model to evaluate the catalyticbehavior of these mixtures as acid Lewis catalyst. These reactions were carried out usingacidic mixtures of 60 mol%. http://www.mdpi.com/1422-0067/8/5/392/ Fri, 11 May 2007 00:00:00 CEST International Journal of Molecular Sciences 2007-05-11 8 5 Article 392 398 1422-0067 Organo-niobate Ionic Liquids: Synthesis, Characterization and Application as Acid Catalyst in Pechmann Reactions 2007-05-11 doi: 10.3390/i8050392 Valerio C. D. Soares Melquizedeque B. Alves Ernesto R. Souza Ivana O. Pinto Joel C. Rubim Carlos Kleber Z. Andrade Paulo A. Z. Suarez