排序方式: 共有161条查询结果,搜索用时 46 毫秒
41.
Aaron J Lorenz Rob P Anex Asli Isci James G Coors Natalia de Leon Paul J Weimer 《Biotechnology for biofuels》2009,2(1):5-8
Background
Improvement of biofeedstock quality for cellulosic ethanol production will be facilitated by inexpensive and rapid methods of evaluation, such as those already employed in the field of ruminant nutrition. Our objective was to evaluate whether forage quality and compositional measurements could be used to estimate ethanol yield of maize stover as measured by a simplified pretreatment and simultaneous saccharification and fermentation assay. Twelve maize varieties selected to be diverse for stover digestibility and composition were evaluated. 相似文献42.
The inexpensive production of sugars from lignocellulose is an essential step for the use of biomass to produce fuel ethanol.
Olive cake is an abundant by-product of the olive oil industry and represents a potentially significant lignocellulosic source
for bioethanol production in the Mediterranean basin. Furthermore, converting olive cake to ethanol could add further value
to olive production. In the present study, olive cake was evaluated as a feedstock for ethanol production. To this end, the
lignocellulosic component of the olive cake was dilute-acid pretreated at a 13.5% olive-cake loading with 1.75% (w/v) sulfuric
acid and heating at 160°C for 10 min. This was followed by chemical elimination of fermentation inhibitors. Soluble sugars
resulting from the pretreatment process were fermented using E. coli FBR5, a strain engineered to selectively produce ethanol. 8.1 g of ethanol/L was obtained from hydrolysates containing 18.1
g of soluble sugars. Increasing the pretreatment temperature to 180°C resulted in failed fermentations, presumably due to
inhibitory by-products released during pretreatment. 相似文献
43.
44.
45.
James M. Aramini Julie L. Tubbs Sreenivas Kanugula Paolo Rossi Asli Ertekin Melissa Maglaqui Keith Hamilton Colleen T. Ciccosanti Mei Jiang Rong Xiao Ta-Tsen Soong Burkhard Rost Thomas B. Acton John K. Everett Anthony E. Pegg John A. Tainer Gaetano T. Montelione 《The Journal of biological chemistry》2010,285(18):13736-13741
46.
A Murat Aytekin Bulent Alten Selim S Caglar Yusuf Ozbel Sinan Kaynas Fatih M Simsek Ozge Erisoz Kasap Asli Belen 《Journal of vector ecology》2007,32(2):226-234
The wing-shape morphology of local populations of the medically important phlebotomine sand flies, Phlebotomus sergenti, P. papatasi, P. tobbi, and P. similis, were examined in both sexes by using geometric morphometrics. There are three major mountain ranges that may serve as geographical barriers for species distribution in the study area and four main gaps were recognized among these barriers. We found no statistically important differences in wing morphology in all examined species in both sexes for all local populations. These results show that the barriers are not sufficient to stop gene flow among local populations of sand flies. The graphical depiction of PCA, CVA, and F-test confirmed our morphometric study suggesting that the difference in wing morphology between P. similis and P. sergenti indicates that these are clearly different species. These two show sympatric distribution in the Konya Plain of Anatolia. 相似文献
47.
Craig L. Bennett Yingzhang Chen Marissa Vignali Russell S. Lo Amanda G. Mason Asli Unal Nabiha P. Huq Saifee Stanley Fields Albert R. La Spada 《PloS one》2013,8(11)
Senataxin is a large 303 kDa protein linked to neuron survival, as recessive mutations cause Ataxia with Oculomotor Apraxia type 2 (AOA2), and dominant mutations cause amyotrophic lateral sclerosis type 4 (ALS4). Senataxin contains an amino-terminal protein-interaction domain and a carboxy-terminal DNA/RNA helicase domain. In this study, we focused upon the common ALS4 mutation, L389S, by performing yeast two-hybrid screens of a human brain expression library with control senataxin or L389S senataxin as bait. Interacting clones identified from the two screens were collated, and redundant hits and false positives subtracted to yield a set of 13 protein interactors. Among these hits, we discovered a highly specific and reproducible interaction of L389S senataxin with a peptide encoded by the antisense sequence of a brain-specific non-coding RNA, known as BCYRN1. We further found that L389S senataxin interacts with other proteins containing regions of conserved homology with the BCYRN1 reverse complement-encoded peptide, suggesting that such aberrant protein interactions may contribute to L389S ALS4 disease pathogenesis. As the yeast two-hybrid screen also demonstrated senataxin self-association, we confirmed senataxin dimerization via its amino-terminal binding domain and determined that the L389S mutation does not abrogate senataxin self-association. Finally, based upon detection of interactions between senataxin and ubiquitin–SUMO pathway modification enzymes, we examined senataxin for the presence of ubiquitin and SUMO monomers, and observed this post-translational modification. Our senataxin protein interaction study reveals a number of features of senataxin biology that shed light on senataxin normal function and likely on senataxin molecular pathology in ALS4. 相似文献
48.
Erdogan S Kacar A Yilmazer D Satar M Tunali N 《Genetic counseling (Geneva, Switzerland)》2004,15(3):335-339
Renal tubular dysgenesis (RTD), a rare, lethal, autosomal recessive disorder, is characterized by short and poorly differentiated proximal tubules and associated with hypoplastic calvaria. We report two cases of RTD with hypoplasia of the calvaria. Microscopically, proximal tubules in the kidneys were not seen on routine H&E stain. Almost all tubules in the cortex were stained for epithelial membrane antigen (EMA), confirming the absence of proximal tubule differentiation. The autopsy findings, microscopic features and the etiology of this rare condition is discussed and compared with literature data. 相似文献
49.
Aging induces cardiac diastolic dysfunction, oxidative stress, accumulation of advanced glycation endproducts and protein modification 总被引:4,自引:0,他引:4
Li SY Du M Dolence EK Fang CX Mayer GE Ceylan-Isik AF LaCour KH Yang X Wilbert CJ Sreejayan N Ren J 《Aging cell》2005,4(2):57-64
Evidence suggests that aging, per se, is a major risk factor for cardiac dysfunction. Oxidative modification of cardiac proteins by non-enzymatic glycation, i.e. advanced glycation endproducts (AGEs), has been implicated as a causal factor in the aging process. This study was designed to examine the role of aging on cardiomyocyte contractile function, cardiac protein oxidation and oxidative modification. Mechanical properties were evaluated in ventricular myocytes from young (2-month) and aged (24-26-month) mice using a MyoCam system. The mechanical indices evaluated were peak shortening (PS), time-to-PS (TPS), time-to-90% relengthening (TR90) and maximal velocity of shortening/relengthening (+/- dL/dt). Oxidative stress and protein damage were evaluated by glutathione and glutathione disulfide (GSH/GSSG) ratio and protein carbonyl content, respectively. Activation of NAD(P)H oxidase was determined by immunoblotting. Aged myocytes displayed a larger cell cross-sectional area, prolonged TR90, and normal PS, +/- dL/dt and TPS compared with young myocytes. Aged myocytes were less tolerant of high stimulus frequency (from 0.1 to 5 Hz) compared with young myocytes. Oxidative stress and protein oxidative damage were both elevated in the aging group associated with significantly enhanced p47phox but not gp91phox expression. In addition, level of cardiac AGEs was approximately 2.5-fold higher in aged hearts than young ones determined by AGEs-ELISA. A group of proteins with a molecular range between 50 and 75 kDa with pI of 4-7 was distinctively modified in aged heart using one- or two-dimension SDS gel electrophoresis analysis. These data demonstrate cardiac diastolic dysfunction and reduced stress tolerance in aged cardiac myocytes, which may be associated with enhanced cardiac oxidative damage, level of AGEs and protein modification by AGEs. 相似文献
50.
The storage of renewable electrical energy within chemical bonds of biofuels and other chemicals is a route to decreasing petroleum usage. A critical challenge is the efficient transfer of electrons into a biological host that can covert this energy into high energy organic compounds. In this paper, we describe an approach whereby biomass is grown using energy obtained from a soluble mediator that is regenerated electrochemically. The net result is a separate-stage reverse microbial fuel cell (rMFC) that fixes CO2 into biomass using electrical energy. We selected ammonia as a low cost, abundant, safe, and soluble redox mediator that facilitated energy transfer to biomass. Nitrosomonas europaea, a chemolithoautotroph, was used as the biocatalyst due to its inherent capability to utilize ammonia as its sole energy source for growth. An electrochemical reactor was designed for the regeneration of ammonia from nitrite, and current efficiencies of 100% were achieved. Calculations indicated that overall bioproduction efficiency could approach 2.7±0.2% under optimal electrolysis conditions. The application of chemolithoautotrophy for industrial bioproduction has been largely unexplored, and results suggest that this and related rMFC platforms may enable biofuel and related biochemical production. 相似文献