共查询到20条相似文献,搜索用时 15 毫秒
1.
Li Y Tschaplinski TJ Engle NL Hamilton CY Rodriguez M Liao JC Schadt CW Guss AM Yang Y Graham DE 《Biotechnology for biofuels》2012,5(1):2
Background
The model bacterium Clostridium cellulolyticum efficiently degrades crystalline cellulose and hemicellulose, using cellulosomes to degrade lignocellulosic biomass. Although it imports and ferments both pentose and hexose sugars to produce a mixture of ethanol, acetate, lactate, H2 and CO2, the proportion of ethanol is low, which impedes its use in consolidated bioprocessing for biofuels production. Therefore genetic engineering will likely be required to improve the ethanol yield. Plasmid transformation, random mutagenesis and heterologous expression systems have previously been developed for C. cellulolyticum, but targeted mutagenesis has not been reported for this organism, hindering genetic engineering. 相似文献2.
3.
Sara González-García Carles Martinez Gasol Maria Teresa Moreira Xavier Gabarrell Joan Rieradevall i Pons Gumersindo Feijoo 《The International Journal of Life Cycle Assessment》2011,16(5):465-477
Purpose
Lignocellulosic ethanol has received special research interest, driven by concerns over high fuel prices, security of energy supplies, global climate change as well as the search of opportunities for rural economic development. A well-to-wheel analysis was conducted for ethanol obtained from black locust (Robinia pseudoacacia L.) by means of the life cycle assessment (LCA) methodology. This study assesses the environmental profile of using ethanol in mixtures E10 and E85 as transport fuel in comparison with conventional gasoline (CG). In addition, the best model of black locust cultivation was analysed under an environmental point of view. 相似文献4.
Nuno P Mira Margarida Palma Joana F Guerreiro Isabel Sá-Correia 《Microbial cell factories》2010,9(1):79
Background
Acetic acid is a byproduct of Saccharomyces cerevisiae alcoholic fermentation. Together with high concentrations of ethanol and other toxic metabolites, acetic acid may contribute to fermentation arrest and reduced ethanol productivity. This weak acid is also a present in lignocellulosic hydrolysates, a highly interesting non-feedstock substrate in industrial biotechnology. Therefore, the better understanding of the molecular mechanisms underlying S. cerevisiae tolerance to acetic acid is essential for the rational selection of optimal fermentation conditions and the engineering of more robust industrial strains to be used in processes in which yeast is explored as cell factory. 相似文献5.
Background
Depending on the carbon source, Saccharomyces cerevisiae displays various degrees of respiration. These range from complete respiration as in the case of ethanol, to almost complete fermentation, and thus very low degrees of respiration on glucose. While many key regulators are known for these extreme cases, we focus here on regulators that are relevant at intermediate levels of respiration. 相似文献6.
Yongsheng Chen Imad Zein Everton Alen Brenner Jeppe Reitan Andersen Mathias Landbeck Milena Ouzunova Thomas Lübberstedt 《BMC plant biology》2010,10(1):12
Background
Reduced lignin content leads to higher cell wall digestibility and, therefore, better forage quality and increased conversion of lignocellulosic biomass into ethanol. However, reduced lignin content might lead to weaker stalks, lodging, and reduced biomass yield. Genes encoding enzymes involved in cell wall lignification have been shown to influence both cell wall digestibility and yield traits. 相似文献7.
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Background
Microorganisms possess diverse metabolic capabilities that can potentially be leveraged for efficient production of biofuels. Clostridium thermocellum (ATCC 27405) is a thermophilic anaerobe that is both cellulolytic and ethanologenic, meaning that it can directly use the plant sugar, cellulose, and biochemically convert it to ethanol. A major challenge in using microorganisms for chemical production is the need to modify the organism to increase production efficiency. The process of properly engineering an organism is typically arduous. 相似文献9.
Kyung Yun Lee Jong Myoung Park Tae Yong Kim Hongseok Yun Sang Yup Lee 《Microbial cell factories》2010,9(1):94
Background
Zymomonas mobilis ZM4 is a Gram-negative bacterium that can efficiently produce ethanol from various carbon substrates, including glucose, fructose, and sucrose, via the Entner-Doudoroff pathway. However, systems metabolic engineering is required to further enhance its metabolic performance for industrial application. As an important step towards this goal, the genome-scale metabolic model of Z. mobilis is required to systematically analyze in silico the metabolic characteristics of this bacterium under a wide range of genotypic and environmental conditions. 相似文献10.
Background
Comparison of experimentally determined mesophilic and thermophilic homologous protein structures is an important tool for understanding the mechanisms that contribute to thermal stability. Of particular interest are pairs of homologous structures that are structurally very similar, but differ significantly in thermal stability. 相似文献11.
Fu-Hui Wu Ming-Tsair Chan De-Chih Liao Chen-Tran Hsu Yi-Wei Lee Henry Daniell Melvin R Duvall Choun-Sea Lin 《BMC plant biology》2010,10(1):68
Background
Oncidium spp. produce commercially important orchid cut flowers. However, they are amenable to intergeneric and inter-specific crossing making phylogenetic identification very difficult. Molecular markers derived from the chloroplast genome can provide useful tools for phylogenetic resolution. 相似文献12.
Gregory Heller Aleksandra Adomas Guosheng Li Jason Osborne Len van Zyl Ron Sederoff Roger D Finlay Jan Stenlid Frederick O Asiegbu 《BMC plant biology》2008,8(1):19
Background
Symbiotic ectomycorrhizal associations of fungi with forest trees play important and economically significant roles in the nutrition, growth and health of boreal forest trees, as well as in nutrient cycling. The ecology and physiology of ectomycorrhizal associations with Pinus sp are very well documented but very little is known about the molecular mechanisms behind these mutualistic interactions with gymnosperms as compared to angiosperms. 相似文献13.
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Background
The development of novel yeast strains with increased tolerance toward inhibitors in lignocellulosic hydrolysates is highly desirable for the production of bio-ethanol. Weak organic acids such as acetic and formic acids are necessarily released during the pretreatment (i.e. solubilization and hydrolysis) of lignocelluloses, which negatively affect microbial growth and ethanol production. However, since the mode of toxicity is complicated, genetic engineering strategies addressing yeast tolerance to weak organic acids have been rare. Thus, enhanced basic research is expected to identify target genes for improved weak acid tolerance. 相似文献15.
Maurizio Bettiga Oskar Bengtsson Bärbel Hahn-Hägerdal Marie F Gorwa-Grauslund 《Microbial cell factories》2009,8(1):40-12
Background
Sustainable and economically viable manufacturing of bioethanol from lignocellulose raw material is dependent on the availability of a robust ethanol producing microorganism, able to ferment all sugars present in the feedstock, including the pentose sugars L-arabinose and D-xylose. Saccharomyces cerevisiae is a robust ethanol producer, but needs to be engineered to achieve pentose sugar fermentation. 相似文献16.
Ryosuke Yamada Naho Taniguchi Tsutomu Tanaka Chiaki Ogino Hideki Fukuda Akihiko Kondo 《Biotechnology for biofuels》2011,4(1):8
Background
Hydrolysis of cellulose requires the action of the cellulolytic enzymes endoglucanase, cellobiohydrolase and β-glucosidase. The expression ratios and synergetic effects of these enzymes significantly influence the extent and specific rate of cellulose degradation. In this study, using our previously developed method to optimize cellulase-expression levels in yeast, we constructed a diploid Saccharomyces cerevisiae strain optimized for expression of cellulolytic enzymes, and attempted to improve the cellulose-degradation activity and enable direct ethanol production from rice straw, one of the most abundant sources of lignocellulosic biomass. 相似文献17.
Background
The bioenergetics of Archaea with respect to the evolution of electron transfer systems is very interesting. In contrast to terminal oxidases, a canonical bc 1 complex has not yet been isolated from Archaea. In particular, c -type cytochromes have been reported only for a limited number of species. 相似文献18.
Background
Single cell analysis for bioprocess monitoring is an important tool to gain deeper insights into particular cell behavior and population dynamics of production processes and can be very useful for discrimination of the real bottleneck between product biosynthesis and secretion, respectively. 相似文献19.
Nien-Tzu Keng Hsun-Hsun Lin Huei-Ru Lin Wei-Kung Hsieh Chih-Chia Lai 《Journal of biomedical science》2012,19(1):11
Background
Acute exposure of ethanol (alcohol) inhibits NMDA receptor function. Our previous study showed that acute ethanol inhibited the pressor responses induced by NMDA applied intrathecally; however, prolonged ethanol exposure may increase the levels of phosphorylated NMDA receptor subunits leading to changes in ethanol inhibitory potency on NMDA-induced responses. The present study was carried out to examine whether acute ethanol exposure influences the effects of ketamine, a noncompetitive NMDA receptor antagonist, on spinal NMDA-induced pressor responses. 相似文献20.
Bin Tang Xiaofei Chen Yang Liu Honggang Tian Jian Liu Jian Hu Weihua Xu Wenqing Zhang 《BMC molecular biology》2008,9(1):51