Effects of β-cyclodextrins on the enzymatical hydrolysis of chiral dichlorprop methyl ester

The effect of β-cyclodextrins(β-CDs) on the enzymatical hydrolysis of chiral dichlorprop methyl ester (DCPPM) was studied.Four kinds of β-cyclodextrins(β-cyclodextrin, Partly methylated-CD( PM-β-CD), hydroxypropyl-cyclodextrin(HP-β-CD) and carboxymethylcyclodextrin(CM-β-CD) ) were used. Compared with 100% DCPPM in the absence of β-cyclodextrins, the activity of lipase decreased with the increase of β-cyclodextrin and PM-β-cyclodextrin. However, CM-β-cyclodextrin stimulated the lipase activity. The inhibition effect of β-cyclodextrin and PM-β-cyclodextrin on the hydrolysis of DCPPM is affected by many factors other than degree of the methylation blocking the active site of lipase. UV-Vis and Fourier transform infrared(FTIR) spectroscopy studies of the complexation of aqueous DCPPM with β-CDs provide fresh insight into the molecular structure of the complex and explain the effects of β-CDs on enzymatical hydrolysis of chiral DCPPM. Data showed that inclusion complexes had formed by complexation of the CM-β-CD with DCPPM and the solubility of DCPPM was increased in water, which leaded to the increased lipase activity.     

基于ELISA的受体竞争结合法检测环境雌激素(Competitive Estrogen Receptor Binding Based ELISA for Detection of Estrogen in Environment)

为建立环境雌激素的体外快速筛选方法,采用免疫测定介导受体竞争结合试验定量检测环境雌激素.将17β-雌二醇-BSA固定在微孔板上,环境雌激素与微孔板上的17β-雌二醇-BSA竞争性地与雌激素受体结合,与微孔板上17β-雌二醇-BSA结合的受体与雌激素受体的抗体、雌激素受体抗体的二抗形成一个三明治形式的复合物,通过显色剂显色,最后用比色法对试验结果进行定量.结果表明,环境雌激素的浓度与溶液吸光度值成负相关.定量研究可以得到环境雌激素剂量-效应关系曲线,在一定浓度范围内(10ng·L-1～100μg·L-1),溶液的吸光度值与环境雌激素的浓度直接呈现良好的线性关系(R2=0.9583).利用这种方法能检测到的标准品雌二醇的最低浓度为10ng·L-1.以上结果表明,本方法检测环境雌激素操作简便,具有广泛的应用前景.     

Extraction of 17p-estradiol in water using non-imprinted polymer submicron particles in membrane filters

17β-Estradiol (E2) is an endocrine disrupting chemical of harm to both animals and human beings at a low concentration level (ng/L).It cannot be completely removed by wastewater treatments,and is often detected in both environment and drinking waters.The purpose of this feasibility study,towards environmental engineering in the field of water analysis and treatment,was to remove E2 by extraction using non-imprinted polymer (NIP) submicron particles.Experimental results showed that 0.5 mg/L of E2 could be completely extracted by adding 10 mg of NIP particles directly into 10 mL of water.However,the extraction efficiency decreased to 64% for 100 mL of water.prefilling the NIP particles inside a membrane filter showed a potential for water treatment of a large volume,requiring no effort to distribute the particles uniformly in the water.High extraction efficiency (80±10)% for E2 was achieved for 100 mL of water.A total mass of 0.29 mg E2 was extracted from 1000 mL of water containing 0.8 mg/L E2 (by using only 10 mg of NIP particles).Both efficiency and mass capacity can be increased,by scaling up the amount of NIP particles,towards environmental engineering applications.     

钛基β-PbO2阳极催化性能及氧化机理研究

采用提拉法和电沉积法制作Ti／SnO2＋Sb2O3／β-PbO2阳极,通过SEM扫描、XRD分析和极化曲线测定表征具有良好结构和催化性能。利用该电极氧化靛红水溶液,表征Ti／SnO2＋Sb2O3／β-PbO2电极氧化机理,阳极氧化以[·OH]氧化有机物,次级氧化以阳极生成的活性相对差、寿命较长的H2O2,O3氧化有机物。Ti／SnO2＋Sb2O3／β-PbO2阳极氧化有机物是湿式氧化费用的30％～50％,具有广泛应用前景。     

固定化菌剂对污水和牛粪中雌二醇和己烯雌酚的去除作用

针对雌二醇(E2)和己烯雌酚(DES)易在污水和牛粪富集的问题,制备了具有去除E2和DES功能的固定化菌剂,并研究了其对污水和牛粪中E2与DES的去除作用.以E2降解菌Rhodococcus sp.JX-2与DES降解菌Serratia sp.S为供试菌,主要通过正交试验确定了固定化菌剂包埋方法,比较了固定化菌剂、游离态菌剂、空白小球对E2与DES的去除效能,并分析了菌剂用量、p H、含水量、翻堆时间对菌剂去除污水和牛粪中E2和DES的影响.结果表明,菌剂制备的最佳固定化条件为菌株JX-2与菌株S菌悬液体积比为1∶1,海藻酸钠质量分数5%,菌胶比为1∶2,Ca Cl2·2H2O质量分数4%.固定化菌剂对溶液中初始浓度为2 mg·L-1E2和DES的去除率分别达99.42%和84.59%.去除污水中E2和DES的最佳固定化菌剂用量为300g·L-1,p H值为5.0~6.0,能完全去除DES,E2去除率为95.85%;去除牛粪中E2和DES的最佳固定化菌剂用量为600g·kg-1,牛粪含水量为70%,翻堆时间间隔为12 h,能完全去除E2,DES去除率为97.41%.     

Inhibitory kinetics of β-N-acetyl-D-glucosaminidase from Nile tilapia (Oreochromis niloticus) by cadmium北大核心CSCD

Cadmium (Cd2+) pollution in an aquatic environment can negatively affect certain reproductive parameters of aquatic animals. β-N-acetyl-D-glucosaminidase (NAGase) is considered to play an important role in the fertilization process. The aim of the present study was to investigate the effect of Cd2+ on the activity of NAGase purified f rom the testis of Nile tilapia, toward contributing new knowledge on the breadth of negative effects of Cd2+ for Nile tilapia production. The kinetic method of substrate reaction was used for this assessment, and an inhibitory model was established to study the kinetics of NAGase under inhibition by Cd2+. The results showed that Cd2+ could reversibly inhibit the enzymatic activity of NAGase, and the half-maximal inhibitory concentration was estimated to be 40.95 mmol/L. Cd2+ was found to be a competitive inhibitor of NAGase, and the inhibitory constant was determined to be 17.13 mmol/L. The microscopic rate constants of inactivation were also determined. Together, these findings demonstrate that Cd2+ is a reversible inhibitor that can competitively inhibit NAGase. These results may provide a theoretical foundation for further studies on the reproduction of tilapia. © 2018 Science Press. All rights reserved.     

聚磷菌胞内多聚物的分析检测方法

PHA、糖原和多聚偏磷酸盐这三种多聚物在聚磷茵（PAOs）体内的代谢和生长有着很重要的作用,它们同时也影响污水处理强化生物除磷系统的处理效果,因此需要对胞内聚合物进行分析测定。本文介绍了监测PHA、糖原和多聚偏磷酸盐的常用定量和定性方法,以及部分方法的提取手段、预处理过程、测定原理以及注意事项。     

催化动力学光度法测定工业废水中的Cr（Ⅵ）

采用β-环糊精作为H₂O₂氧化茜素红褪色反应的增敏剂,建立了催化动力学光度法测定工业废水中Cr（Ⅵ）的新方法。该方法最佳反应条件为：反应体系总体积25 mL,0.1 mol/L的H₂SO₄溶液加入量2.0 mL,1.0×10^-3 mol/L茜素红溶液加入量1.5 mL,30%的H₂O₂溶液加入量4.0 mL,100 g/L的β-环糊精溶液加入量3.0 mL。在最大吸收波长554 nm处测定反应前后溶液的吸光度,Cr（Ⅵ）的质量浓度与吸光度差值（ΔA）在4.0×10^-4~5.4×10^-2 mg/L范围内符合比尔定律,线性回归方程为：ΔA=18.52ρ+ 0.018,相关系数为0.996 6,检出限为3.5×10^-4 mg/L,加标回收率为99.46%~101.3%,6次测定的相对标准偏差小于等于2.4%。该法的测定结果与GB/T 7467-1987中的二苯碳酰二肼分光光度法相近。     

DOM结构特征及其对17β-雌二醇光降解的影响

参照国际腐殖酸协会(IHSS)推荐的方法从滇池底泥提取出胡敏酸(HA)和富里酸(FA),以Sigma Aldrich胡敏酸(SAHA)为参照,利用元素分析、13C核磁共振和紫外-可见光谱对HA和FA的来源和结构进行了表征,并探讨了3种溶解性有机质(DOM)对17β-雌二醇(E2)光降解的影响.结果表明:HA、FA和SAHA具有相似的元素组成,3种腐殖酸的(N+O)/C值分别为0.50、0.82和0.55,与核磁共振13C谱分析的极性指数(0.32、0.42和0.33)一致.HA和FA来自于内源,具有较高的N含量和较多的缔合芳香结构,而SAHA是外源性有机质,具有更高的芳香度.低浓度的3种腐殖酸均能促进E2发生服从准一级动力学规律的光化学降解过程.E2在纯水中光降解速率为0.0071h-1,而在5mgC/L的HA、FA和SAHA作用下,E2光降解速率分别为0.0597、0.1178和0.2048h-1.3种腐殖酸促进E2光降解能力的差异主要是由含氧能团和芳香结构含量差异所致.活性氧分子探针鉴定显示HO?是腐殖酸体系受光照后产生的一种重要活性氧,其氧化降解E2的量占到了E2降解总量的70%左右.与低浓度腐殖酸相比,高浓度的3种腐殖酸均会对E2光降解产生抑制作用.     

Electrokinetic movement of multiple chlorobenzenes in contaminated soils in the presence of β-cyclodextrin

This study investigated the electrokinetic (EK) behavior of multiple chlorobenzenes, including 1,2,3,4-tetrachlorobenzene (TeCB), 1,2,4,5-tetrachlorobenzene (i-TeCB), and 1,2,3-trichlorobenzene (TCB) in contaminated clayed soils. The effect of β-cyclodextrin (β-CD) on the EK removal of the chlorobenzenes was studied. The largest removal was obtained when Na2CO3/NaHCO3 buffer was used as anodic purging solution without β-CD. The removal efficiencies were related to the aqueous solubilities of chlorobenzenes. With the same cumulative electroosmotic flow, greater solubility led to higher removal efficiency. The addition of β-CD inhibited the EK removal efficiency of all chlorobenzenes. The inhibition increased with the increase of β-CD concentration. With the same β-CD concentration, the inhibition increased with the rise of electric potential. It was found that the inclusion compounds between β-CD and chlorobenzenzes were less soluble than chlorobenzenes. The formation of the less soluble inclusion compounds reduced the aqueous solubility of chlorobenzenes and led to the partial immobilization of the chlorobenzenes that desorbed from soil. It was feasible to use the EK technology to remove chlorobenzenes in contaminated soils using water as the anodic flushing solution. The addition of β-CD was not recommended for the EK removal of chlorobenzenes.