碳酸钠碱性介质氧脱木素促进火炬松酶解糖化的研究

分别采用硫酸盐法（KP）和绿液法（GL）蒸煮火炬松，并以碳酸钠为碱性介质进行氧脱木素，所得浆料分别标记为KP-OC浆和GL-OC浆，分析了这两种浆料的化学组分，并对这两种浆料进行酶解以提取可发酵单糖。结果显示，在120℃氧脱木素4 h所得的KP-OC浆和GL-OC浆的木素脱出率均明显优于相近条件下以氢氧化钠为碱性介质且脱木素1 h的浆料。对于GL-OC浆和KP-OC浆，当酶用量为10 FPU/g时，酶解单糖得率、总单糖提取率最高分别可达73.2%和95.8%、72.4%和75.7%，均优于相近条件下以氢氧化钠为碱性介质氧脱木素的浆料。     

Preclinical Evaluation of 99mTc-ZHER2:41071, a Second-Generation Affibody-Based HER2-Visualizing Imaging Probe with a Low Renal Uptake

Radionuclide imaging of HER2 expression in tumours may enable stratification of patients with breast, ovarian, and gastroesophageal cancers for HER2-targeting therapies. A first-generation HER2-binding affibody molecule [^99mTc]Tc-ZHER2:V2 demonstrated favorable imaging properties in preclinical studies. Thereafter, the affibody scaffold has been extensively modified, which increased its melting point, improved storage stability, and increased hydrophilicity of the surface. In this study, a second-generation affibody molecule (designated ZHER2:41071) with a new improved scaffold has been prepared and characterized. HER2-binding, biodistribution, and tumour-targeting properties of [^99mTc]Tc-labelled ZHER2:41071 were investigated. These properties were compared with properties of the first-generation affibody molecules, [^99mTc]Tc-ZHER2:V2 and [^99mTc]Tc-ZHER2:2395. [^99mTc]Tc-ZHER2:41071 bound specifically to HER2 expressing cells with an affinity of 58 ± 2 pM. The renal uptake for [^99mTc]Tc-ZHER2:41071 and [^99mTc]Tc-ZHER2:V2 was 25–30 fold lower when compared with [^99mTc]Tc-ZHER2:2395. The uptake in tumour and kidney for [^99mTc]Tc-ZHER2:41071 and [^99mTc]Tc-ZHER2:V2 in SKOV-3 xenografts was similar. In conclusion, an extensive re-engineering of the scaffold did not compromise imaging properties of the affibody molecule labelled with ^99mTc using a GGGC chelator. The new probe, [^99mTc]Tc-ZHER2:41071 provided the best tumour-to-blood ratio compared to HER2-imaging probes for single photon emission computed tomography (SPECT) described in the literature so far. [^99mTc]Tc-ZHER2:41071 is a promising candidate for further clinical translation studies.     

Bioethanol production from corn stalk juice using Saccharomyces cerevisiae TISTR 5020

This study aimed to use sweet corn hybrid hi-brix53 stalk juice for bioethanol production, to give a solution to the growing problem of food vs. fuel and to utilize waste for cheaper production. Hi-brix 53 stalk juice contained 112.07 ± 2.99 g L^?1 of total sugars and 21.83 ± 1.09 g L^?1 of reducing sugars. Through fermentation (24–120 h) using yeast (Saccharomyces cerevisiae), it produced 6.01% (v/v) bioethanol. The final ethanol produce (g L^?1) yield efficiency and volumetric ethanol productivity were at the highest at 24 h with 47.87 L^?1, 87.62% and 1.97 ± 0.06 (g L^?1 h^?1). These results suggest that hi-brix 53 stalk juice is an ideal substrate for bioethanol production.     

Second generation bioethanol (SGB) production potential in Turkey

Energy demand is increasing by the years. Population's needs and technological investments bring the new approach about generating energy. It is considered that fossil fuels will not be able to respond to all energy requirements after approximately 150 years. Turkey imports nearly all of its petroleum and so this causes major economic problems. Turkey, as a major cereal producer, has a huge potential to grow energy crops and other cellulosic biomaterials and can obtain plant's residues, which are suitable to produce second generation bioethanol (SGB). With domestic production, bioethanol can reduce the dependence of petroleum for Turkey, and greenhouse gas emissions can be decreased. Taking into account Turkey's situation in fuel–oil consumption, costliness of gasoline and environmentally hazardous specification of fossil fuels, bioethanol gains more importance and increases in value. Especially, SGB production is rising. Foodstuffs are valuable, and producing ethanol from directly those materials can cause a crisis in Turkey because lignocellulosic bioethanol is becoming prominent. In this regard, bioethanol production in Turkey becomes a major alternative to petroleum and may be a key to new and clean energy source. Copyright © 2013 John Wiley & Sons, Ltd.     

An overview of algae bioethanol production

Because of rapid growth in population and industrialization, worldwide ethanol demand is increasing continuously. The first‐generation and second‐generation biofuels are unable to meet the global demand of bioethanol production because of their primary value of food and feed. Therefore, algae are among the most potentially significant sources of sustainable biofuels in the future of renewable energy because of the accumulating high starch/cellulose and because they are widely distributed in nature. The focus of this paper is to review the production and recent advances in research and development in the algae bioethanol, including pretreatment, hydrolysis, and fermentation of algae biomass. Despite the many developments made in the recent years, commercialization of algal bioethanol remains challenging chiefly because of the techno‐economic constraints. Technological breakthroughs in all major aspects must be overcome before it can be a successfully large‐scale and commercialized product. Copyright © 2014 John Wiley & Sons, Ltd.     

Evaluation of Two Sets of Sorghum Bagasse Samples as the Feedstock for Fermentable Sugar Recovery via the Calcium Capturing by Carbonation (CaCCO) Process

Abstract: Sorghum bagasse samples from two sets (n6 and bmr6; n18 and bmr18) of wild-type and corresponding “brown midrib” (bmr) mutant strains of sweet sorghum were evaluated as the feedstock for fermentable sugar recovery via the calcium capturing by carbonation (CaCCO) process, which involves Ca(OH)₂ pretreatment of bagasse with subsequent neutralization with CO₂ for enzymatic saccharification. Saccharification tests under various pretreatment conditions of the CaCCO process at different Ca(OH)₂ concentrations, temperatures or residence periods indicated that bmr strains are more sensitive to the pretreatment than their counterparts are. It is expected that variant bmr6 is more suitable for glucose recovery than its wild-type counterpart because of the higher glucan content and better glucose recovery with less severe pretreatment. Meanwhile, bmr18showed higher scores of glucose recovery than its counterpart did, only at low pretreatment severity, and did not yield higher sugar recovery under the more severe conditions. The trend was similar to that of xylose recovery data from the two bmr strains. The advantages of bmr strains were also proven by means of simultaneous saccharification and fermentation of CaCCO-pretreated bagasse samples by pentose-fermenting yeast strain Candida shehatae Cs 4R. The amounts needed for production of 1 L of ethanol from n6, bmr6, n18, and bmr18samples were estimated as 4.11, 3.46, 4.03, and 3.95 kg, respectively. The bmr strains seem to have excellent compatibility with the CaCCO process for ethanol production, and it is expected that integrated research from the feedstock to bioprocess may result in breakthroughs for commercialization.     

Evaluation of Barros and Wolf Efficiency Correlations for Conventional and Extractive Distillation Columns in Bioethanol Production Process

In view of the increasing environmental concern, the use of renewable and less pollutant energy sources has been encouraged. In this context, bioethanol has been used as fuel in the anhydrous form, blended with gasoline. In this work, simulations of the extractive distillation process in anhydrous bioethanol production were carried out in Aspen Plus® using nonequilibrium stage model and equilibrium stage model with Barros and Wolf efficiency correlations for plate and component. Equilibrium stage model with plate efficiency determined through Barros and Wolf efficiency correlation showed a satisfactory agreement with results predicted by the nonequilibrium stage model for anhydrous bioethanol production process.     

六碳糖和五碳糖同步糖化与共发酵的数学模型

Reliable production of biofuels and specifically bioethanol has attracted a significant amount of re-search recently.Within this context,this study deals with dynamic simulation of bioethanol production processes and in particular aims at developing a mathematical model for describing simultaneous saccharification and co-fermentation (SSCF) of C6 and C5 sugars.The model is constructed by combining existing mathematical mod-els for enzymatic hydrolysis and co-fermentation.An inhibition of ethanol on cellulose conversion is introduced in order to increase the reliability.The mathematical model for the SSCF is verified by comparing the model predic-tions with experimental data obtained from the ethanol production based on kraft paper mill sludge.When fitting the model to the data,only the yield coefficients for glucose and xylose metabolism were fine-tuned,which were found to be 0.43 g·g-1 (ethanol/glucose) and 0.35 g·g-1 (ethanol/xylose) respectively.These promising validation results encourage further model application to evaluate different process configurations for lignocellulosic bioetha-nol technology.