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The key catabolic enzymes of D-xylose, an important structural component of different agricultural wastes, were studied in cells of mutant strains of the xylose-assimilating yeast Pachysolen tannophilus. The evaluation of catalytic activity and cofactor specificity of xylose reductase (ЕС 1.1.1.307) and xylitol dehydrogenase (ЕС 1.1.1.9) confirmed the dependence of intracellular catabolic pathway for D-xy lose on the NAD×H/NADP×H ratio, formed under microaerobic conditions. The study of total activity of some NAD+ /NAP×H-dependent dehydrogenases revealed the metabolic characteristics of the yeast cells, which could ensure selective ethanol or xylitol production. Thus, the efficient involvement of D-xylose into the Embden–Meyerhof–Parnas pathway provided not only the high activities of xylose reductase and xylitol dehydrogenase, but also of 1-glycerophosphate dehydrogenase (EC 1.1.1.8) and lactate dehydrogenase (ЕС 1.1.1.27), respectively. The inhibition of activity of these enzymes led to selective production of xylitol from D-xylose. On the base of the experimental results, the principles of metabolic engineering of xylose-assimilating yeasts were formulated. The possibility of bioethanol and xylitol production from different agricultural wastes using xyloseassimilating yeasts are discussed.

Description of the subject. Extracellular enzymes from filamentous fungi are increasingly used in eco-friendly biotransformation processes. Their relevant technological role and their stability towards extreme process conditions make of them the first sustainable solution for the elaboration of bio-based products from biomass conversion. Objectives. This paper describes the isolation of filamentous fungi from decaying plant material in the region of Meknes (northern central Morocco) and the assessment of their ability to breakdown lignocellulose. The objective is to select performant fungi with enzymatic machinery adapted to local environment and with potential for the breakdown of the regional specific lignocellulosic by-products into potentially high-value molecules. Method. Cereals, decaying wood, olive-pomace and -pulp and their composts were used to isolate lignocellulolytic fungi. One hundred twenty-seven pure strains were isolated and screened at 25 °C on selective media with cellulose or lignin as the sole carbon source. Performant strains were validated for the production of ligno-cellulolytic enzymes and identified using molecular technique. Results. Twenty-eight fungi had mycelial diameter on cellulose ≥ 6 cm and cellulolytic index ≥ 0.9. Twenty-two strains had the same profile on lignin medium. The production of endoglucanase, lignin peroxidase and manganese peroxidase enzymes was confirmed in performant strains using qualitative assay and molecular identification revealed that the best performing fungi were Mucor circinelloides, Mucor racemosus, Penicillium brasilianum, Penicillium crustosum, Paecilomyces sp., Fusarium oxysporum, Fusarium solani, Aspergillus fischeri, Curvularia spicifera, Humicola grisea, Trichoderma atroviride and Cosmospora viridescens. Measurement of ligno-cellulolytic activities revealed that Penicillium and Fusarium strains mainly from wood decay and compost had the best profiles among performing strains. Conclusions. Isolated fungi are high decomposers of biomass and represent a prominent solution to develop green bioprocesses in the region.

Pressure is rising to alter the accounting system used to calculate emissions due to bioenergy under the Kyoto Protocol and the EU Emissions Trading Scheme because it does not capture the full extent of greenhouse gas (GHG) emissions from bioenergy use. Both the European Union (EU) and United States (U.S.) are engaged in consultation processes targeted on how to treat emissions connected with use of biomass for energy within regulatory systems hence this discussion of accounting options is timely. The paper first classifies alternative accounting systems into the following three basic approaches: 1) CO2 emissions produced when biomass is burnt for energy are not counted at the point of combustion but are accounted for in the land use sector as carbon stock losses (a combustion factor = 0 approach);. 2) CO2 emissions produced when biomass is burnt for energy are accounted for in the energy sector; uptake of CO2 from the atmosphere by plants and soils may, or may not, be accounted for (a combustion factor = 1 approach); 3) End users are responsible for all or a specified subset of emissions that occur along the bioenergy value chain regardless of where these emissions occur (a value chain approach). The paper then evaluates these approaches against general criteria, and assesses their impacts on a selected set of stakeholder goals. The general criteria are: (a) comprehensiveness; (b) simplicity; and (c) scale independence. Stakeholder goals to be examined are: (a) stimulation of rural economies (b) food security, (c) GHG reductions, and (d) preservation of forests. Given that it is unlikely that all countries will accept greenhouse gas emission targets in the future, we find that: 0-combustion factor accounting systems rank low on comprehensiveness but are relatively simple and scale­independent. Systems with a 1-combustion factor tend to be more comprehensive, and can be both simple and scale­independent. End-user systems vary in comprehensiveness, tend to be complicated and are scale-dependent. While stimulating rural economies, the current system (0-combustion factor) does not foster food security, reduce GHG emissions or preserve forests. 1-combustion factor approaches can support rural economies and food security but tend not to preserve forest. In value-chain approaches, mandates to use biofuels determine impacts on rural economies and food security. These systems can be effective in forest preservation and achieving GHG reductions. Proceedings of the 19th European Biomass Conference and Exhibition, 6-10 June 2011, Berlin, Germany, pp. 2398-2407

{"references": ["European Commission: \"Roadmap to a Single European Transport Area - Towards a competitive and resource-efficient transport system\", pp. 5, 2011.", "G. Szendro, \"Congestion charging in Budapest - a comparison with existing systems\", Periodica Polytechnica, To be published.", "G. Szendro, \"Sustainable biofuels in Hungary and Europe - self-defeating incentives?\" Gazdalkodas Scientific Journal on Agricultural Economics, English Special Edition, pp. 71-78, ISSN 0046-5518, 2010.", "P. R. Ehrlich, J. P. Holdren, \"Impact of population growth\", Science, 1971.", "The World Bank: \"World Development Indicators & Global Development Finance\", 2010", "British Petrol: Statistical Review of World Energy 2011", "G. Szendro, M. Csete, A. Torok,\"Unbridgeable gap between transport policy and practice in Hungary\", Journal of Environmental Engineering and Landscape Management, To be published.", "International Energy Agency, FIA Foundation: \"50 by 50, global fuel economy initiative\", pp. 6., 2008.", "http://www.afdc.energy.gov/afdc/data/vehicles.html,\taccessed \n2011.09.19\n[10] http://www.eurocarblog.com/post/3322/electric-cars-europe-vs-the-us, accessed 2011.09.19"]} The effects of the transport sector on the environment are a well-recognized issue in the European Union and around the world. This area is a subject of much discussion as to how these negative effects could be minimized, especially with regards to impacts contributing to climate change. This paper aims to investigate the results of the economic crisis and how its consequences could be exploited to combat air pollution.

Defining alternatives for non-renewable energy sources constitutes a priority to the development of our societies. One of these alternatives is biofuels production starting from energy crops, agricultural wastes, forest products or wastes. In this context, a "second generation" biofuels production, aiming at utilizing the whole plant, including ligno-cellulosic (hemicelluloses, cellulose, lignin) fractions (Ogier et al., 1999) that are not used for human food, would allow the reduction of the drawbacks of bioethanol production (Schoeling, 2007). However, numerous technical, economical, ethical and environmental questions are still pending. One of the aims of the BioEtha2 project, directed by the Walloon Agricultural Research Centre, is to define the position of bioethanol produced from ligno-cellulosic biomass among the different renewable energy alternatives that could be developed in Wallonia towards 2020. With this aim, and in order to answer the numerous questions in this field, the project aims at using tools and methods coming from the concept of "forecasting scenarios" (Sebillotte, 2002; Slegten et al., 2007; For-learn, 2008). This concept, based on a contemporary reality, aims to explore different possible scenarios for the future development of alternative sources of energy production. The principle is to evaluate, explore, possible futures of the studied problematic, through the establishment of possible evolution trajectories. We contribute to this prospective through a systemic approach (Vanloqueren, 2007) that allows lightening the existing interactions within the system "ligno-cellulosic biomass chain" without isolating it from its environment. We explain and sketch the two contexts needed to identify primary stakes. The global context includes inter-dependant and auto-regulating fields such as society, politics, technology and economy. These four fields influence each part of the "chain" with specific tools. However, the interest and possible action fields lay within the intermediary context representing the "resources" such as agriculture, forestry, "driving" elements such as mobility, mediation elements such as territories and environment and concurrent elements such as non-cellulosic biomass, the energy mix and the non-energy valorization.

One presents the methods to combat the negative effects of any natural and renewable energy sources, which by their inexhaustibility are one self-capable to assure the sustainable development of the humanity. In this aim one considers for the fortuitous energies: solar with waste and axial rotor twisted blades, wave with wind and river energies the possibilities to satisfy the consume requirements by their combine exploitation, as well as the river Dorin Pavel’s complex uses solutions to take away against the floods and also the drought, like the Black Sea deep-water naturalization with energy recoveries.

Among the lignocellulosic materials explored for bioconversion into value-added products, sugarcane bagasse (SB) has shown profound applications. Considering its recalcitrance structure, dilute acid hydrolysis (DAH) is necessary to release fermentable sugars for their subsequent bio-based conversion into products of commercial significance. In addition to sugars, toxic compounds are also released during DAH, which are inhibitors to fermenting microorganisms. Detoxification of SB hydrolysates is necessary to eliminate inhibitors from the hydrolysates. This study aimed to evaluate the process of dilute acid hydrolysis for SB to obtain a hydrolysate rich in xylose followed by its detoxification by overliming and activated charcoal. DAH showed xylose concentration of 12.5 g/L. The obtained hydrolysate was concentrated 3 times by vacuum evaporation and submitted to detoxification by calcium oxide overliming followed by activated charcoal. The concentrated acid hydrolysate after detoxification showed a xylose concentration of 33.0 g/L and a reduction of 81% and 61% for furfural and HFM, respectively. The results obtained from the study are effective to obtain a hydrolysate rich in fermentable sugars, with a low amount of inhibitors compounds which can be directly employed in fermentative process for the production of several commercially important products. Proceedings of the 20th European Biomass Conference and Exhibition, 18-22 June 2012, Milan, Italy, pp. 1603-1606

{"references": ["Alonso, A. et al., Future CO2 concentrations, though not warmer temperatures, enhance wheat photosynthesis temperature responses. Physiologia Plantarum, 2008. 132(1): p. 102-112.", "Fengel, D. and X. Shao, A chemical and ultrastructural study of the bamboo species Phyllostachys makinoi Hay. Wood Science and Technology, 1984. 18(2): p. 103-112.", "Zhong, C., et al., Optimization of enzymatic hydrolysis and ethanol fermentation from AFEX-treated rice straw. Applied microbiology and biotechnology, 2009. 84(4): p. 667-676.", "Niu, K. et al., Enhanced enzymatic hydrolysis of rice straw pretreated by alkali assisted with photocatalysis technology. Journal of Chemical Technology and Biotechnology, 2009. 84(8): p. 1240-1245.", "Zhao, X., Y. Song, and D. Liu, Enzymatic hydrolysis and simultaneous saccharification and fermentation of alkali/peracetic acid-pretreated sugarcane bagasse for ethanol and 2, 3-butanediol production. Enzyme and microbial technology, 2011. 49(4): p. 413-419.", "Buaban, B., et al., Bioethanol production from ball milled bagasse using an on-site produced fungal enzyme cocktail and xylose-fermenting< i> Pichia stipitis. Journal of bioscience and bioengineering, 2010. 110(1): p. 18-25.", "Miller, G.L., et al., Measurement of carboxymethylcellulase activity. Analytical Biochemistry, 1960. 1(2): p. 127-132.", "Kumar, R., S. Singh, and O.V. Singh, Bioconversion of lignocellulosic biomass: biochemical and molecular perspectives. Journal of industrial microbiology & biotechnology, 2008. 35(5): p. 377-391."]} Conversion of lignocellulosic biomass is the basis process for production of fuels, chemicals and materials in the sustainable biorefinery industry. Saccharification of lignocellulosic biomass is an essential step which produces sugars for further conversion to target value-added products e.g. bio-ethanol, bio-plastic, g-valerolactone (GVL), 5-hydroxymethylfuroic acid (HMF), levulinic acid, etc. The goal of this work was to develop an efficient enzyme for conversion of biomass to reducing sugar based on crude fungal enzyme from Chaetomium globosum BCC5776 produced by submerged fermentation and evaluate its activity comparing to a commercial Acremonium cellulase. Five local biomasses in Thailand: rice straw, sugarcane bagasse, corncobs, corn stovers, and palm empty fruit bunches were pretreated and hydrolyzed with varying enzyme loadings. Saccharification of the biomass led to different reducing sugar levels from 115 mg/g to 720 mg/g from different types of biomass using cellulase dosage of 9 FPU/g. The reducing sugar will be further employed as sugar feedstock for production of ethanol or commodity chemicals. This work demonstrated the use of promising enzyme candidate for conversion of local lignocellulosic biomass in biorefinery industry.