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71.
Production of ethanol and biomass from thin stillage by Neurospora intermedia: A pilot study for process diversification 下载免费PDF全文
Jorge A. Ferreira Patrik R. Lennartsson Mohammad J. Taherzadeh 《Engineering in Life Science》2015,15(8):751-759
Dry mill ethanol processes produce ethanol and animal feed from whole grains, where the wastewater after the distillation and separation of solid materials is called “thin stillage.” In this work, similar production of ethanol (3.5 g/L) and biomass (5 g/L) from thin stillage was obtained during batch cultivation of the edible fungus Neurospora intermedia in a 2‐m high airlift reactor and bubble column. The fungal biomass, containing 50% w/w protein and 12% w/w lipids, was rich in essential amino acids and omega‐3 and ‐6 fatty acids. In a continuous mode of fermentation, dilution rates of up to 0.2 h?1 could be applied without cell washout in the bubble column at 0.5 vvm. At 0.1 h?1, around 5 g/L of ethanol and 4 g/L of biomass containing ca. 50% w/w protein were produced. The fungus was able to assimilate saccharides in the liquid fraction as well as sugar backbones such as xylan and arabinan in the solid fraction. The inclusion of the current process could potentially lead to the production of 11 000 m3 of ethanol (5.5% improvement vs. normal industrial process) and around 6300 tons of high‐quality biomass for animal feed at a typical facility producing 200 000 m3 ethanol per year. 相似文献
72.
目的:探讨连续肾脏替代治疗(CRRT)对脓毒症患者血清中肿瘤坏死因子alpha(TNF-alpha)、白介素-6(IL-6)和白介素-8(IL-8)的
影响。方法:将我院2013 年1 月-2014 年6 月间收治的80 例脓毒症患者随机分为观察组与对照组各40 例,两组患者均给予脓毒
症常规治疗,观察组另给予CRRT 治疗。观察比较两组患者治疗前1 天,治疗后24 h,72 h空腹静脉血TNF-alpha、IL-6、IL-8 水平。结
果:观察组治愈率为85.0%(34/40),明显高于对照组的55.0%(22/40),差异有统计学意义(P<0.05);治疗24h、72h 后两组患者
TNF-alpha、IL-6和IL-8 水平均明显下降,其中观察组下降更显著,差异均有统计学意义(P<0.05)。结论:CRRT 能有效降低脓毒症患
者血清中TNF-alpha、IL-6 和IL-8 水平,有助于对炎症反应的正向调节。 相似文献
73.
Roza K. Sypniewska Nancy J. Millenbaugh Johnathan L. Kiel Robert V. Blystone Heather N. Ringham Patrick A. Mason Frank A. Witzmann 《Bioelectromagnetics》2010,31(8):656-663
A macrophage assay and proteomic screening were used to investigate the biological activity of soluble factors in the plasma of millimeter wave‐exposed rats. NR8383 rat macrophages were incubated for 24 h with 10% plasma from male Sprague–Dawley rats that had been exposed to sham conditions, or exposed to 42 °C environmental heat or 35 GHz millimeter waves at 75 mW/cm2 until core temperature reached 41.0 °C. Two‐dimensional polyacrylamide gel electrophoresis, image analysis, and Western blotting were used to analyze approximately 600 protein spots in the cell lysates for changes in protein abundance and levels of 3‐nitrotyrosine, a marker of macrophage stimulation. Proteins of interest were identified using peptide mass fingerprinting. Compared to plasma from sham‐exposed rats, plasma from environmental heat‐ or millimeter wave‐exposed rats increased the expression of 11 proteins, and levels of 3‐nitrotyrosine in seven proteins, in the NR8383 cells. These altered proteins are associated with inflammation, oxidative stress, and energy metabolism. Findings of this study indicate both environmental heat and 35 GHz millimeter wave exposure elicit the release of macrophage‐activating mediators into the plasma of rats. Bioelectromagnetics 31:656–663, 2010. © 2010 Wiley‐Liss, Inc. 相似文献
74.
Here we extend the classic Hawk-Dove model of animal conflict to allow for continuous variation in fighting strengths. Whereas the winner of a fight is chosen at random in the discrete game, in our continuous game, the winner of any fight is the stronger individual, and costs are higher for more evenly matched opponents. We identify the evolutionary stable strength threshold beyond which an animal should be prepared to engage in aggressive behaviour and show that this threshold increases with variance in fighting strength when the costs of aggression are insensitive to the level of strength asymmetry, but decreases with variance when the costs are sensitive to the level of asymmetry. In contrast to the classic discrete game, population-wide aggressive behaviour occurs only when the costs of fighting are zero. It is now known that animals can eavesdrop on the outcome of contests between neighbours and modify their behaviour towards observed winners and losers. We therefore further extend our model to allow for social eavesdropping within networks comprising three individuals. Whereas earlier work showed that eavesdropping increases the frequency of mutually aggressive contests in the discrete game by enhancing the value of victory, here we show that aggression thresholds in the continuous game are always higher with eavesdropping than without it: for sufficiently weak animals, avoiding the costs of challenging an observed winner over-rides the potential benefit of winning, so that eavesdropping reduces the frequency of aggressive encounters. Thus, even though strength is not directly observable, information is extracted from the variation in fighting ability that the classic Hawk-Dove game ignores. 相似文献
75.
Extracellular human granulocyte-macrophage colony stimulating factor (hGM-CSF) expression was studied under the control of
the GAP promoter in recombinant Pichia pastoris in a series of continuous culture runs (dilution rates from 0.025 to 0.2 h−1). The inlet feed concentration was also varied and the steady state biomass concentration increased proportionally demonstrating
efficient substrate utilization and constancy of the biomass yield coefficient (Yx/s) for a given dilution rate. The specific product formation rate (qP) showed a strong correlation with dilution rates demonstrating growth associated product formation of hGM-CSF. The volumetric
product concentration achieved at the highest feed concentration (4×) and a dilution rate of 0.2 h−1 was 82 mg l−1 which was 5-fold higher compared to the continuous culture run with 1× feed concentration at the lowest dilution rate thus
translating to a 40 fold increase in the volumetric productivity. The specific product yield (YP/X) increased slightly from 2 to 2.5 mg g−1, with increasing dilution rates, while it remained fairly invariant, for all feed concentrations demonstrating negligible
product degradation or feed back inhibition. The robust nature of this expression system would make it easily amenable to
scale up for industrial production. 相似文献
76.
Tetala KK Chen B Visser GM Maruska A Kornysova O van Beek TA Sudhölter EJ 《Journal of biochemical and biophysical methods》2007,70(1):63-69
A simple method for the preparation of an affinity monolithic (also called continuous bed) capillary column for alpha-mannose-specific lectins is described. 2-Hydroxyethyl methacrylate in combination with (+)-N,N -diallyltartardiamide (DATD) and piperazine diacrylamide (PDA, 1,4-bisacryloyl-piperazine) as crosslinkers, were used as monomers for the monolith. After oxidation of DATD with periodate, alpha-mannose with spacer was bound to the aldehyde groups of the polymeric skeleton via reductive amination to form an affinity column for the separation, enrichment or binding studies of mannose-specific lectins. The permeability of the column was excellent. The porosity of the monolith was investigated by scanning electron microscope (SEM) and inverse size exclusion chromatography (ISEC). The affinity of the monolith was evaluated by frontal analysis (FA) and fluorescence microscopy (FM) using fluorescently labeled concanavalin (Con A). Frontal affinity chromatography showed a specific interaction of two different lectins with the alpha-mannose-modified monolith. According to FM the affinity sites were evenly distributed over the monolithic bed. 相似文献
77.
Schmid MG Koidl J Wank P Kargl G Zöhrer H Gübitz G 《Journal of biochemical and biophysical methods》2007,70(1):77-85
Particle-loaded monoliths containing a polymethacrylamide backbone were prepared by suspending a silica-based chiral phase in the mixture of the monomers followed by in-situ polymerization in the capillary. As chiral selector l-4-hydroxyproline chemically bonded to 3 microm silica particles was used following the separation principle of ligand-exchange. Electrolytes containing Cu(II) ions were used. Amino acid enantiomers were separated by capillary-LC and CEC, whereby the latter showed the better resolution properties. For the chiral separation of alpha-hydroxy acids the EOF was reversed by copolymerizing diallyldimethylammonium chloride instead of vinylsulfonic acid as charge providing agent. Short columns of 6 cm were found to be sufficient in the case of CEC for baseline separations of amino acids with alpha values up to 5. 相似文献
78.
The enzymes 6-hydroxymethylpterin pyrophosphokinase (HPPK) and dihydropteroate synthase (DHPS) catalyze sequential steps in folate biosynthesis. They are present in microorganisms but absent in mammals and therefore are especially suitable targets for antimicrobials. Sulfa drugs (sulfonamides and sulfones) currently are used as antimicrobials targeting DHPS, although resistance to these drugs is increasing. The most widely used assay that measures activity of these enzymes, to assess new inhibitors in vitro, is not amenable to automation. This article describes a simple, coupled, enzymatic spectrophotometric assay where the product of the DHPS reaction, dihydropteroate, is reduced to tetrahydropteroate by excess dihydrofolate reductase (DHFR) using the cofactor NADPH. The oxidation of NADPH is monitored at 340 nm. The activity of both HPPK and DHPS can be measured in this assay, and it has been used to measure kinetic parameters of wild-type and sulfa drug-resistant DHPS enzymes to demonstrate the utility of the assay. It is a sensitive and reproducible assay that can be readily automated and used in multiwell plates. This NADPH-coupled microplate photometric assay could be used for rapid screening of chemical libraries for novel inhibitors of folate biosynthesis as the first step in developing new antimicrobial drugs targeting the folate biosynthetic pathway. 相似文献
79.
Hu DN Hwang SM Lin XZ Yang PY Tsai CH Huang Q Huang HY Hwang MH 《In vitro cellular & developmental biology. Animal》2007,43(3-4):105-108
Incidence of colon cancer has increased rapidly in China. Although many colon cancer cell lines have been established previously,
most of them were derived from patients from western countries. Epidemiological, clinical, cytogenetic, and molecular biological
studies showed that there are considerable differences between Chinese and western countries colon cancer patients. Therefore,
establishment of novel colon cancer cell line from Chinese is useful for studying the racial difference of this disease and
can be important for studying the pathogenesis of colon cancer in China. In our laboratory, two novel continuous human colon
cancer cell lines, SHT-1 and SHH-1, have been established in vitro from Chinese patients, and both cell lines have been passaged
for 4 yr, and they have been continuously subcultured with more than 800 population doubling and without signs of senescence.
Both cell lines were obtained from primary tumor tissues during colon cancer surgery. Cells grew rapidly with a doubling time
of 36–39 h and a plating efficiency of 26–28%. These cells exhibited an epithelial morphology and expressed cytokeratin. Tumor
developed in severe combined immunodeficient (SCID) mice 4–6 wk after inoculated subcutaneously with the cultured cancer cells.
Karyotypic analysis and comparative genomic hybridization (CGH) analysis in SHT-1 cells revealed a hypertriploid modal number
of 76 with numerous numerical and structural abnormalities previously linked to colon cancer. In another cell line (SHH-1),
CGH analysis revealed that −1p13 was the only cytogenetic anomaly. 相似文献
80.
The optimal distribution of biocatalyst in a fixed bed operating at steady state was determined to minimize the length of
the bed for a fixed conversion of 95%. The distribution in terms of the biocatalyst loading on an inert support depends upon
the axial distance from the bed entrance (continuous solution) as well as a set of dimensionless parameters that reflect the
bed geometry, the bulk flow, reaction kinetics and diffusional characteristics. A mathematical model of the system with the
following features was used to obtain the results: (1) convective mass transfer and dispersion in the bulk phase; (2) mass
transfer from the bulk phase to the surface of the catalyst particle; and (3) simultaneous diffusion and chemical reaction
in the catalyst particle with Michaelis–Menton kinetics and a reliable diffusion model (Zhao and DeLancey in Biotechnol Bioeng
64:434–441, 1999, 2000). The solution to the mathematical model was obtained with Mathematica utilizing the Runge Kutta 4–5 method. The dimensionless
length resulting from the continuous solution was compared with the optimal length restricted to a uniform or constant cell
loading across the entire bed. The maximum difference in the dimensionless length between the continuous and uniform solutions
was determined to be 6.5%. The model was applied to published conversion data for the continuous production of ethanol that
included cell loading (Taylor et al. in Biotechnol Prog 15:740–751, 2002). The data indicated a minimum production cost at a catalyst loading within 10% of the optimum predicted by the mathematical
model. The production rate versus cell loading in most cases displayed a sufficiently broad optimum that the same (non-optimal)
rate could be obtained at a significantly smaller loading such as a rate at 80% loading being equal to the rate at 20% loading.
These results are particularly important because of the renewed interest in ethanol production (Novozymes and BBI International,
Fuel ethanol: a technological evolution, 2004). 相似文献