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91.
Summary Flocculent cells ofKluyveromyces
marxianus SM 16-10 were used for batch production of ethanol from the inulin sugars derived from Jerusalem artichoke tubers. Using 20% initial sugar concentration, a maximum ethanol concentration of 92 g/l was achieved in 7 h, when the flocculent cell concentration was 30 g dry wt./l bioreactor volume. The same flocculent cells were used repeatedly for 7 batch runs starting with fresh medium at the beginning of each run. The ethanol yield was found to be almost constant at about 94% of the theoretical for all the 7 batch cycles, while the maximum ethanol production rate increased from 17.21 g ethanol/1/h during the first batch run to 21 g ethanol/1/h during the last batch run. 相似文献
92.
93.
Issidora S. Papassideri Kevin R. Leonard Deryck Mills Lukas H. Margaritis 《Journal of structural biology》1999,127(3):258-262
The innermost chorionic layer (ICL) in eggshells of Drosophila melanogaster is a naturally occurring patchwork of thin three-dimensional crystalline plates located between the inner endochorion and the vitelline envelope. The mass-per-unit area of the ICL has been measured from scanning transmission electron microscope images of isolated unstained material and it was possible to distinguish up to four layers with the majority of the crystalline sheets being one to three layers thick. Taking into account the unit cell areas for the different crystals, we have estimated the mean ICL subunit sizes to be 36 kDa for Drosophila melanogaster, 35 kDa for Drosophila auraria, and 33 kDa for Drosophila teissieri. The results suggest that the three different Drosophilidae species have very similar average subunit masses. 相似文献
94.
The phylogeny of selected genera from four subfamilies of fungus gnats (Diptera: Mycetophilidae) – Manotinae, Leiinae, Sciophilinae and Gnoristinae (including Metanepsiini) – is reconstructed based on the combined analysis of five mitochondrial (12S, 16S, COI, COII, cytB) and two nuclear (28S, ITS2) gene markers. Results of the different analyses all support Manotinae as a monophyletic group, with Leiinae as the sister group. Allactoneura DeMeijere is nested in the monophyletic and strongly supported clade of Leiinae. The tribe Metanepsiini is revealed as paraphyletic and the genera Metanepsia Edwards and Chalastonepsia Søli do not appear to be closely related. The genera Docosia Winnertz, Ectrepesthoneura Enderlein, Novakia Strobl and Syntemna Winnertz were placed with a group of genera included traditionally in the Gnoristinae. The monophyly of Dziedzickia Johannsen and Phthinia Winnertz is not supported. The genera of Sciophilinae (excluding Paratinia Mik but including Eudicrana Loew) form a monophyletic group in the Bayesian model. 相似文献
95.
Microbially produced gamma‐polyglutamic acid (γ‐PGA) is a commercially important biopolymer with many applications in biopharmaceutical, food, cosmetic and waste‐water treatment industries. Owing to its increasing demand in various industries, production of γ‐PGA is well documented in the literature, however very few methods have been reported for its recovery. In this paper, we report a novel method for the selective recovery and purification of γ‐PGA from cell‐free fermentation broth of Bacillus licheniformis. The cell‐free fermentation broth was treated with divalent copper ions, resulting in the precipitation of γ‐PGA, which was collected as a pellet by centrifugation. The pellet was resolubilized and dialyzed against de‐ionized water to obtain the purified γ‐PGA biopolymer. The efficiency and selectivity of γ‐PGA recovery was compared with ethanol precipitation method. We found that 85% of the original γ‐PGA content in the broth was recovered by copper sulfate‐induced precipitation, compared to 82% recovery by ethanol precipitation method. Since ethanol is a commonly used solvent for protein precipitation, the purity of γ‐PGA precipitate was analyzed by measuring proteins that co‐precipitated with γ‐PGA. Of the total proteins present in the broth, 48% proteins were found to be co‐precipitated with γ‐PGA by ethanol precipitation, whereas in copper sulfate‐induced precipitation, only 3% of proteins were detected in the final purified γ‐PGA, suggesting that copper sulfate‐induced precipitation offers better selectivity than ethanol precipitation method. Total metal content analysis of the purified γ‐PGA revealed the undetectable amount of copper ions, whereas other metal ions detected were in low concentration range. The purified γ‐PGA was characterized using infrared spectroscopy. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010 相似文献
96.
JEAN‐CLAUDE WALSER MICHAEL B. EVGENEV MARTIN E. FEDER 《Molecular ecology resources》2006,6(2):563-567
We adapted a recently developed nonrestrictional, nonligational genome walking method, Universal Fast Walking (UFW), for detection of length polymorphism in the proximal promoter region of genes. We demonstrate its efficacy at discovering naturally occurring transposition into heat‐shock genes of wild Drosophila and show that it surmounts limitations of simple polymerase chain reaction (PCR) approaches. We further present modifications to the standard UFW protocol and provide some guidelines to improve specificity. Although the resultant banding pattern of a standard UFW can be regarded as a DNA fingerprint, many amplicons result from false priming and not real polymorphisms. We describe ways to distinguish between UFW amplicons and false priming products in a high‐throughput assay. 相似文献
97.
Tissue kallikrein (KLK1) and kallikrein-related peptidases (KLK2-15) comprise a family of 15 highly conserved secreted serine proteases with similar structural characteristics and a wide spectrum of functional properties. Both gene expression and protein activity of KLKs are rigorously controlled at various levels via diverse mechanisms, including extensive steroid hormone regulation, to exert their broad physiological role. Nevertheless, deregulated expression, secretion, and function of KLK family members has been observed in several pathological conditions and, particularly, in endocrine-related human malignancies, including those of the prostate, breast, and ovary. The cancer-related abnormal activity of KLKs upon substrates such as growth factors, cell adhesion molecules, cell surface receptors, and extracellular matrix proteins facilitate both tumorigenesis and disease progression to the advanced stages. The well-documented relationship between KLK status and the clinical outcome of cancer patients has led to their identification as promising diagnostic, prognostic, and treatment response monitoring biomarkers for these complex disease entities. The main objective of this review is to summarize the existing knowledge concerning the role of KLKs in prostate, breast, and ovarian cancers and to highlight their continually evolving biomarker capabilities that can provide significant benefits for the management of cancer patients. 相似文献
98.
The effects of surface properties of Saccharomyces cerevisiae strains 468/pGAC9 and 468 on adhesion to polyethyleneimine (PEI) and/glutaraldehyde (GA) pre-treated cotton (CT), polyester (PE), polyester + cotton (PECT), nylon (NL), polyurethane foam (PUF), and cellulose re-enforced polyurethane (CPU) fibers were investigated. Process parameters (circulation velocity, pH, ionic strength, media composition and surfactants) were also examined. 80%, 90%, and 35% of the cells were adsorbed onto unmodified CT, PUF, and PE, respectively. PEI-GA pre-treated CT and alkali treated PE yielded 25% and 60% cell adhesion, respectively. Adsorption rate (Ka) ranged from 0.06 to 0.17 for CT and 0.06-0.16 for PE at varied pH. Adhesion increased by 15% in the presence of ethanol, low pH and ionic strength, and decreased by 23% in the presence of yeast extract and glucose. Shear flow and 1% Triton X-100 detached 62% and 36% nonviable cells from PE and CT, respectively, suggesting that cell immobilization in fibrous-bed bioreactors can be controlled to optimize cell density for long-term stability. 相似文献
99.
Ivanciu L Toso R Margaritis P Pavani G Kim H Schlachterman A Liu JH Clerin V Pittman DD Rose-Miranda R Shields KM Erbe DV Tobin JF Arruda VR Camire RM 《Nature biotechnology》2011,29(11):1028-1033
Effective therapies are needed to control excessive bleeding in a range of clinical conditions. We improve hemostasis in vivo using a conformationally pliant variant of coagulation factor Xa (FXa(I16L)) rendered partially inactive by a defect in the transition from zymogen to active protease. Using mouse models of hemophilia, we show that FXa(I16L) has a longer half-life than wild-type FXa and does not cause excessive activation of coagulation. Once clotting mechanisms are activated to produce its cofactor FVa, FXa(I16L) is driven to the protease state and restores hemostasis in hemophilic animals upon vascular injury. Moreover, using human or murine analogs, we show that FXa(I16L) is more efficacious than FVIIa, which is used to treat bleeding in hemophilia inhibitor patients. FXa(I16L) may provide an effective strategy to enhance blood clot formation and act as a rapid pan-hemostatic agent for the treatment of bleeding conditions. 相似文献
100.
Mpakou VE Velentzas AD Velentzas PD Margaritis LH Stravopodis DJ Papassideri IS 《Development, growth & differentiation》2011,53(6):804-815
Programmed cell death (PCD) is an evolutionary conserved and genetically regulated form of cell death, in which the cell plays an active role in its own demise. It is widely recognized that PCD can be morphologically classified into three major types: type I, known as apoptosis, type II, called autophagy, and type III, specified as cytoplasmic cell death. So far, PCD has been morphologically analyzed in certain model insect species of the meroistic polytrophic ovary-type, but has never been examined before in insects carrying meroistic telotrophic ovaries. In the present study, we attempted to thoroughly describe the three different types (I, II and III) of PCD occurring during oogenesis in the meroistic telotrophic ovary of the Coleoptera species Adalia bipunctata, at different developmental ages of the adult female insects. We reveal that in the ladybird beetle A. bipunctata, the ovarian tropharia undergo age-dependent forms of apoptotic, autophagic and cytoplasmic (paraptotic-like) cell death, which seem to operate in a rather synergistic fashion, in accordance with previous observations in Diptera and Lepidoptera species. Furthermore, we herein demonstrate the occurrence of morphogenetically abnormal ovarioles in A. bipunctata female insects. These atretic ovarioles collapse and die through a PCD-mediated process that is characterized by the combined activation of all three types of PCD. Conclusively, the distinct cell death programs (I, II and III) specifically engaged during oogenesis of A. bipunctata provide strong evidence for the structural and functional conserved nature of PCD during insect evolution among meroistic telotrophic and meroistic polytrophic ovary-type insects. 相似文献