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1.
A novel bioactive foam emulsion bioreactor for benzene, toluene and xylene (BTX) contaminated air streams treatment has been developed. The gas-liquid interfacial area by biocompatible foam and driving force for mass transfer by a water immiscible organic phase were increased in this reactor. The effect of several parameters such as gas residence time, oxygen content, and organic phase concentration on bioreactor performance was studied. Experimental results showed an average elimination capacity (EC) of 220 g&;#8226;m-3&;#8226;h-1 with removal efficiency (RE) of 89.59% for BTX inlet concentration of 1 g&;#8226;m-3 at 15 s gas residence time in the bioreactor. The statistical developed model predicted that the maximum elimination capacity of the reactor for BTX could be reached to 423.45 g&;#8226;m-3&;#8226;h-1. Continues operation of the bioreactor with high EC and RE was demonstrated by optimizing the operational parameters of the bioreactor. Overall the results suggest that the bioreactor developed can be very effective systems to treat BTX vapors.  相似文献   

2.
The adsorption and mechanism of Re(VII) on resin D318 were studied using chemical methods and IR spectrometry. At pH 5.2, the static and dynamic saturation adsorption capacities were 351.4 and 366.5 mg&;#8226;g&;#61485;1, respectively. The adsorption behavior obeyed the Freundlich empirical equation and the adsorption rate constant k298 was 6.37×10&;#61485;4 s&;#61485;1. The desorption percentage was up to 99.7% when 2.0 mol&;#8226;L&;#61485;1 KSCN was used for dynamic desorption.  相似文献   

3.
改性超细煤粉对甲基橙的吸附行为研究   总被引:1,自引:0,他引:1       下载免费PDF全文
The adsorption of methyl orange onto ultrafine coal powder (UCP) and modified ultrafine coal powder (MUCP) from aqueous solutions were studied, in which the influence of contact time, dosage, temperature, pH, and methyl orange concentration in the solution were investigated. The adsorption kinetics of methyl orange by UCP and MUCP can be described by the Lagergren first-order and pseudo second-order kinetic models, respectively. The adsorption isotherms of methyl orange onto MUCP at 303, 313 and 323 K follow the Freundlich and Langmuir isotherm equation. Values of G0 for methyl orange adsorption onto MUCP are -22.55, -23.10 and -23.79 kJ•mol-1 at 303, 313, and 323 K, respectively. The values of ΔH0 and ΔS0 are -3.74 kJ•mol-1 and 61.99 J•mol-1, respectively. The adsorption process is spontaneous and exothermic.  相似文献   

4.
Supercritical CO2 (SC-CO2) extraction technology and ultrasonic technology were used to extract two active sex hormones, estradiol and progesterone, and insulin-like growth factor-1 (IGF-1) from antler velvet. The effects of SC-CO2 extraction condition on the extraction yield and content of sex hormones, the ultrasonic extraction condition on the content of IGF-1 and the SC-CO2 extraction condition on the activity remaining of IGF-1 were studied. The optimal conditions were obtained. The experimental results showed that, in presence of 75% ethanol as the co-solvent, the mean yield and content of estradiol and progesterone were 87.67 pg•g-1 and 1224.10 pg•g-1, 12.38 ng•g-1 and 354.06 ng•g-1, respectively, with extraction pressure of 30 MPa, temperature of 35°C, extraction time of 30 min and CO2 consumption of 15 L•g-1 at the flow rate of 2.0 L•min-1. The highest content of IGF-1 was 7425.75 ng•g-1 antler velvet residue, when the pH10 ammonia-ammonium chloride buffer solution was used as the solvent, the ratio of solvent to sample was 20/1 (volume/mass), the extraction temperature was 0-35°C, and the ex-traction time was 4×15 min. Under these conditions, 93.68% activity remaining of IGF-1 in the residue was ob-tained, while little IGF-1 activity exists in traditional residue. The experimental results indicate that the technology of SC-CO2 with co-solvent is of advantage for getting high content sexual hormones and keeping high activity of IGF-1 in the residue, which can not be achieved by traditional extraction methods.  相似文献   

5.
Amine-functionalized mesoporous silica was prepared by using lauric acid and N-stearoyl-l-glutamic acid as structure directing agents via the SN+-I mechanism and applied to CO2 adsorption at room temperature. With γ-aminopropyltriethoxysilane as co-structure directing agent and due to the direct electrostatic interaction with anionic surfactant, most of the amino groups were uniformly distributed at the inner surface of pores and the performance was stable. The amine-functionalized mesoporous silica was characterized by Fourier transform infrared spectrometer, X-ray diffraction, nitrogen physisorption and thermogravimetric analysis. The CO2 adsorption capacity was measured by digital recording balance. At the room temperature and under the atmospheric pres-sure, the adsorption capacity of LAA-AMS-0.2 for CO2 and N2 is 1.40 mmol•g1 and 0.03 mmol•g1, respectively, indicating high separation coefficient of CO2/N2.  相似文献   

6.
The separation of Eu3+ is studied with a dispersion combined liquid membrane (DCLM), in which polyvinylidene fluoride membrane (PVDF) is used as the liquid membrane support, dispersion solution containing HCl solution as the stripping solution, and 2-ethyl hexyl phosphonic acid-mono-2-ethyl hexyl ester (P507) dissolved in kerosene as the membrane solution. The effects of pH value, initial concentration of Eu3+ and different ionic strength in the feed phase, volume ratio of membrane solution to stripping solution, concentration of HCl solution, concentration of carrier, different stripping agents in the dispersion phase on the separation are investigated. The optimum condition for separation of Eu3+ is that concentration of HCl solution is 4.0 mol•L1, concentration of carrier is 0.16 mol•L1, and volume ratio of membrane solution to stripping solution is 30︰30 in the dispersion phase, and pH value is 4.2 in the feed phase. The ionic strength has no significant effect on separation of Eu3+. Under the optimum condition, when the initial concentration of Eu3+ is 0.8×104 mol•L1, the separation percentage of Eu3+ is 95.3% during the separation time of 130 min. The kinetic equation is developed in terms of the law of mass diffusion and the theory of interface chemistry. The diffusion coefficient of Eu3+ in the membrane and the thickness of diffusion layer between feed phase and membrane phase are obtained and their values are 1.48×107 m2•s1 and 36.6 μm, respectively. The results obtained are in good agreement with literature data.  相似文献   

7.
刺芹侧耳多功能过氧化物酶的纯化与鉴定   总被引:1,自引:1,他引:0       下载免费PDF全文
A versatile peroxidase (VP-Peco60-7) was generated and purified from the liquid culture of Pleurotus eryngii. The purification procedure included ammonium sulfate precipitation, ion exchange chromatography, and gel chromatography. The molecular weight and isoelectric point (pI) of VP-Peco60-7 were determined to be approximately 40 kDa and 4.1, respectively. By N-terminal sequence determination and peptide mapping analysis, VP-Peco60-7 was found to be similar to the versatile peroxidase isoenzyme VPL1, which was previously isolated from liquid cultures of the same species. However, the molecular weight and pI of VP-Peco60-7 were different from those of versatile peroxidases of liquid cultures, implying that the VP-Peco60-7 in this study is of a novel type. With 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) as a substrate, the maximal enzyme activity was obtained at 50 °C and pH 3.0. The catalysis of ABTS by VP-Peco60-7 was expressed by the Michaelis-Menten equation. At 50 °C and pH 3.0, the maxi-mum velocity (Vmax) was 188.68 U•mg1 and the michaelis constant (Km) was 203.09 mmol•L1.  相似文献   

8.
A型分子筛对甲烷水合物生成的影响   总被引:2,自引:0,他引:2       下载免费PDF全文
The porous medium has an important effect on hydrate formation. In this paper, the formation process and the gas storage capacity of the methane hydrate were investigated with A-type zeolite and Sodium Dodecyl Sulfate (SDS) existing in the system. The results show that A-type zeolite can influence methane hydrate formation. At the temperature of 273.5 K and pressure of 8.3 MPa, the distilled water with A-type zeolite can form methane hydrate with gaseous methane in 12 hours. The formation process of the system with A-type zeolite was quite steady and the amount of A-type zeolite can influence the gas storage capacity significantly. The adding of A-type zeolite with 0.067 g•(g water)-1 into 2×10-3 g•g-1 SDS-water solution can increase the gas storage capacity, and the maxi-mum increase rate was 31%. Simultaneously the promotion effect on hydrate formation of 3A-type zeolite is much more obvious than that of 5A-type zeolite when the water adding amounts are 0.033 g•g-1 and 0.067 g•g-1 at the experimental conditions.  相似文献   

9.
Baker’s yeast number 6 was selected by screening. It showed good catalytic activity and enantioselectivity for asymmetric reduction of 2,5-hexanedione to produce (2S,5S)-2,5-hexanediol. Gas chromatography-mass spectrometry (GC-MS) revealed that the intermediate was (S)-5-hydroxyhexane-2-one. Reduction of 2,5-hexanedione proceeded in a two-step reaction. The hydroxyketone was initially formed, and this intermediate was further re-duced to the diol. Factors influencing the product yield and the enantiomeric excess of the reduction of 2,5-hexandione catalyzed by baker’s yeast number 6 were investigated. Higher concentration (≤100 mmol•L-1) of 2,5-hexandione did not influence 5-hydroxyhexane-2-one production, but 2,5-hexanediol production was inhibited by excess accumulation (>30 mmol•L-1) of intermediate. The optimal conditions were glucose as the co-substrate at an initial glucose concentration of 20 g•L-1, 34C, pH 7.0 and cell concentration 60 g•L-1 (cell dry mass). Under the optimal condition and an initial substrate concentration of 30 mmol•L-1, the yield of 2,5-hexandiol was 78.7% and the enantiomeric excess of (2S,5S)-2,5-hexandiol was 94.4% for 24-h reduction.  相似文献   

10.
甲苯与叔丁醇在补铝HM沸石催化剂上的烷基化反应   总被引:1,自引:0,他引:1       下载免费PDF全文
The realuminated H-mordenite catalysts (HM1-4) treated with different concentrations of NaOH and NaAlO2 aqueous solutions were prepared, and characterized by inductively coupled plasma (ICP), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR) and temperature-programmed desorption of ammonia, They are of lower Si/Al ratio and higher acid amount while keeping a high relative crystallinity. Their catalytic performances were evaluated with the liquid-phase tert-butylation of toluene with tert-butyl alcohol in a 100 ml stainless steel batch reactor equipped with a stirrer. HM2 zeolite catalyst, obtained by treating HM in 0.1 mol•L-1 NaOH followed by 0.05 mol•L-1 NaAlO2 aqueous solution, shows a higher catalytic activity because of its highest acid amount. For HM2 catalyst the influences of reaction conditions on catalytic performance were investigated. The conversion of toluene is 50.3% and the selectivity of p-tert-butyltoluene is 74.7% at a temperature of 180°C, 2 of molar ratio of tert-butyl alcohol to toluene, 4h of reaction time and 0.2 of M(catalyst)/M(toluene).  相似文献   

11.
Mango peel is a good source of protease but remains an industrial waste. This study focuses on the optimization of polyethylene glycol (PEG)/dextran-based aqueous two-phase system (ATPS) to purify serine protease from mango peel. The activity of serine protease in different phase systems was studied and then the possible relationship between the purification variables, namely polyethylene glycol molecular weight (PEG, 4000-12,000 g·mol(-1)), tie line length (-3.42-35.27%), NaCl (-2.5-11.5%) and pH (4.5-10.5) on the enzymatic properties of purified enzyme was investigated. The most significant effect of PEG was on the efficiency of serine protease purification. Also, there was a significant increase in the partition coefficient with the addition of 4.5% of NaCl to the system. This could be due to the high hydrophobicity of serine protease compared to protein contaminates. The optimum conditions to achieve high partition coefficient (84.2) purification factor (14.37) and yield (97.3%) of serine protease were obtained in the presence of 8000 g·mol(-1) of PEG, 17.2% of tie line length and 4.5% of NaCl at pH 7.5. The enzymatic properties of purified serine protease using PEG/dextran ATPS showed that the enzyme could be purified at a high purification factor and yield with easy scale-up and fast processing.  相似文献   

12.
张佑红  靖志强  马静  徐鹏  陈龙 《化工学报》2010,61(4):942-948
昆虫细胞-杆状病毒表达系统已经广泛应用于生物杀虫剂及重组蛋白的大规模生产。在昆虫细胞-杆状病毒表达系统中,感染策略中的感染复数(MOI)、感染时间(TOI)、细胞初始浓度(ICD)的相互关系还不是很清楚,而且相关报道也很少。本研究在摇瓶中利用正交实验探讨了MOI、TOI及ICD的相互作用关系以及对包涵体病毒(OV)和非包涵体病毒(BV)产量的影响。结果表明,感染复数对OV和BV产量有显著的影响;最佳感染条件为MOI为0.1,TOI为细胞处于对数生长期初期,ICD为2×105cells.ml-1;最大BV病毒滴度为2.0×107TCID50.ml-1。将在摇瓶中获得的最佳条件在气升式反应器进行扩大试验,获得最大病毒滴度为2.13×107TCID50.ml-1。  相似文献   

13.
高强度耐有机溶剂蛋白酶的纯化及性质   总被引:1,自引:0,他引:1  
分离纯化了自行筛选的耐有机溶剂的地衣芽孢杆菌Bacillus licheniformis YP1所产的溶剂稳定性蛋白酶. 发酵液经硫酸铵沉淀、疏水层析及强阳离子交换层析纯化,得到电泳纯的蛋白酶;分子量约为28 kDa,纯化蛋白酶的比酶活达到1.18′105 U/mg,纯化倍数为37.2,酶活回收率为20.8%. 纯化的YP1蛋白酶对50%(j)的多种亲水或疏水有机溶剂具有很高的耐受性,其中50%(j)的DMF和DMSO能显著促进YP1蛋白酶活力. YP1蛋白酶为Zn2+蛋白酶,最适反应温度为55℃,最适反应pH为10.0,pH 8.0~13.0范围内具有高活力. 以酪蛋白为底物,YP1蛋白酶的米氏常数Km为0.048 g/L.  相似文献   

14.
吴庆丽  秦刚  黄艳飞  刘玮  阳淑 《农药》2020,59(5):379-381,390
[目的]为了筛选防治茶尺蠖(Ectropis oblique Prout)的植物源农药。[方法]通过室内活性测定和田间药效试验,研究了3种植物源农药对茶尺蠖的防治效果。[结果]室内测定结果显示:1%苦参·印楝素乳油、1.2%苦参·烟碱乳油2000 mg/L(制剂用量)对茶尺蠖2龄幼虫生物活性最高,其次为1.3%苦参碱水剂2000 mg/L(制剂用量),3种植物源农药药后72 h对该虫的校正死亡率分别为96.65%、91.65%和81.65%。田间防效试验结果显示:1%苦参·印楝素乳油、1.2%苦参·烟碱乳油和1.3%苦参碱水剂2000 mg/L(制剂用量)均表现出了对茶尺蠖较高的田间防效,药后7 d的田间防效分别为95.62%、94.23%和87.96%;苦参碱混剂的田间防效显著高于苦参碱单剂。3种植物源农药对茶尺蠖的防效均显著高于2.5%溴氰菊酯乳油667 mg/L(制剂用量)。[结论]植物源农药1%苦参·印楝素乳油和1.2%苦参·烟碱乳油对茶尺蠖有较高的防效,可用于该虫的防控。  相似文献   

15.
Protease activity was detected in the culture medium of Serratia marcescens AP3801 grown at 10°C, which was isolated from soil collected from the top of a mountain. The enzyme, designated as CP-58 protease, was purified to homogeneity from the culture broth by ion exchange and gel filtration chromatographies. The molecular mass of the protease was 58 kDa, and its isoelectric point was close to 6.0. Maximal activity toward azocasein was observed at 40°C and from pH 6.5 to 8.0. The activity was strongly inhibited by 1,10-phenanthroline, suggesting that the enzyme is a metalloprotease. The N-terminal amino acid sequence was Ser-Leu-Asn-Gly-Lys-Thr-Asn-Gly-Trp-Asp-Ser-Val-Asn-Asp-Leu-Leu-Asn-Tyr-His-Asn-Arg-Gly-Asn (or Asp)-Gly-Thr-Ile-Asn-Asn-Lys-Pro-Ser-Phe-Asp-Ile-Ala. A search through databases for sequence homology aligned CP-58 protease with metalloprotease. The result of the cleavage pattern of oxidized insulin B-chain suggests that CP-58 protease has a broader specificity than other proteases against the peptide substrate.  相似文献   

16.
混合模式吸附层析从猪血浆中分离免疫球蛋白   总被引:8,自引:7,他引:1       下载免费PDF全文
混合模式吸附层析是一种新型的生物分离方法,通常结合了静电和疏水相互作用,具有非盐依赖的吸附特性,在高盐和低盐条件下,都可以高效吸附目标蛋白。本文将混合模式吸附用于从猪血浆中分离免疫球蛋白,首先比较了不同沉淀法从猪血浆中去除纤维蛋白原,确定了最佳硫酸铵沉淀条件;进一步考察了混合模式吸附剂对猪血免疫球蛋白的静态和动态吸附性能,确定了吸附和解吸条件;最后采用混合模式吸附层析,从硫酸铵沉淀的上清液中直接分离免疫球蛋白,得率为11.5 mg·ml~(-1)血浆,SDS-PAGE凝胶图像分析纯度达到77.4%,为猪血资源的综合利用提供了新方法。  相似文献   

17.
The enzyme cellobiose dehydrogenase (CDH), with high ability of electron transport, has been widely used in enzymatic fuel cells or biosensors. In this study, the cellobiose dehydrogenase gene from Phanerochaete chrysosporium KCCM 60256 was amplified and expressed in the methylotrophic yeast Pichia pastoris X-33. The recombinant enzyme (PcCDH) was purified using a metal affinity chromatography under non-denaturing conditions. The purified enzyme was analyzed by SDS-PAGE, confirming a corresponding band about 100 kDa. The enzyme activity of this purified PcCDH was determined as 1,845U/L (65mg/L protein). The enzyme showed the maximum activity at pH 4.5 and high activity in broad ranges of temperature from 30°C to 60°C. Moreover, the application of PcCDH to enzymatic fuel cell (EFC) was demonstrated. Lactose was used as the substrate in the EFC system; anode and cathode were immobilized with PcCDH and laccase, respectively. The cell’s open circuit voltage and maximum power density of the EFC system were, respectively, determined as 0.435 V and 314 μW/cm2 (at 0.247 V) with 10 mM lactose.  相似文献   

18.
重组大肠杆菌VG1(pTU14)产PHB的补料分批培养   总被引:4,自引:0,他引:4       下载免费PDF全文
利用已构建的同时含有透明颤菌血红蛋白基因 (vgb)、λ噬菌体裂解基因 (S-RRz)和PHB合成基因(phbCAB)的产PHB基因工程大肠杆菌VG1(pTU14 ) ,在 5L发酵罐里进行补料分批培养 .研究发现 :碳氮比(C/N) ,DO(溶氧 )及碳源和氮源的浓度是影响菌体生长和PHB积累的重要因素 ;补料时间可以通过DO和 pH值两个参数的变化在线综合识别 ;流加策略应使发酵前期菌体大量生长 ,发酵后期PHB大量积累 .在优化条件下 ,对VG1(pTU14 )进行 6 0h的补料分批培养 ,菌体细胞浓度、PHB浓度和PHB占细胞干质的分数分别高达2 15 .9g·L-1、 193.7g·L-1和 89.7% .  相似文献   

19.
采用十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)、免疫印迹法(WB)和噻唑蓝(MTT)比色法对化妆品中表皮生长因子(EGF)进行快速检测。得到SDS-PAGE和WB的检出限分别为0.500 mg/L和0.005 mg/L;样品1中EGF质量浓度约为2 mg/L,样品2中EGF质量分数约为10μg/g;MTT检测样品1和样品2中EGF的活性分别为1.14×104IU/mL和1.97×105IU/g。结果表明,采用SDS-PAGE、WB、MTT比色法快速检测化妆品中的EGF可行,可为建立EGF类化妆品的质量标准提供实验依据。  相似文献   

20.
γ-谷氨酰转肽酶(GGT;EC2.3.2.2)催化的酰基转移反应可用于制备各种具有生理活性的谷氨酰化合物,对其开展酶活力不可逆抑制动力学研究对于阐明GGT的作用机制具有重要意义。今以化学抑制剂Woodward's Reagent K(WRK)与枯草芽孢杆菌NX-2产出的GGT进行不可逆抑制反应,根据邹氏理论测得WRK对GGT不可逆抑制反应的微观速率常数ki为0.03015s-1,WRK与酶结合常数KI为1.352mmol·L-1。有抑制剂存在下GGT与供体γ-谷氨酰对硝基苯胺的亲和力常数Km*=3.245mmol·L-1,GGT酰基化最大反应速度Vmax*=0.3771mmol·(L·s)-1。通过对GGT的失活动力学分析得到,失活反应级数为1.313,说明在GGT活性部位至少有一个谷氨酸(或天冬氨酸)残基参与催化反应。  相似文献   

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