酶偶联分光光度法测定胞内黄嘌呤氧化酶活性

建立了新的酶反应体系显色分光光度法检测节杆菌胞内黄嘌吟氧化酶的活性。考察了温度、pH值和底物浓度对检测体系的影响,确定了黄嘌呤氧化酶活性检测的最优条件,获得了良好的检测线性关系。此检测方法操作简便,结果准确可靠,可作为普通实验室和临床上测定黄嘌呤氧化酶活性的有效生化手段。     

辣根过氧化物酶降解苯酚废水催化特性研究

采用辣根过氧化物酶催化降解苯酚,研究了辣根过氧化物酶浓度、pH值、反应温度对苯酚去除率的影响。结果表明,辣根过氧化物酶生物催化体系对苯酚有良好的降解效果。当温度为30℃,pH值为6时,在苯酚、H2O2、辣根过氧化物酶浓度分别为1 mmol/L,1.2 mmol/L,0.5μg/mL条件下,反应25 min,可以获得70%左右的苯酚去除率。利用双倒数作图法测定了不同酶浓度的催化动力学参数,动力学参数Kcat,Kcat/Km表明,苯酚的去除率和催化反应速率随着酶浓度的增加而增大;辣根过氧化物酶的催化效率与催化体系中酶和底物浓度有关,过高的底物浓度会降低酶的催化效率。     

Kinetic degradation of amoxicillin by using the electro-Fenton process in the presence of a graphite rods from used batteries

This study reports the removal of amoxicillin(AMX) in aqueous media using the electro-Fenton process in the presence of a graphite cathode recovered from used batteries.The impact of the relevant parameters on the electro-Fenton process,namely the applied current intensity,the temperature,the initial concentration of AMX and the initial concentration of ferrous ions were investigated.The results showed that the optimal values were:I=600 mA,T=25℃,[AMX]_0=0.082 mmol·L~(-1) and [Fe~(2+])=1 mmol·L~(-1),leading to 95% degradation and 74% mineralization.The model parameters of AMX mineralization were determined using nonlinear methods,showing that it follows a pseudo-second-order kinetic.The Energy consumption(EC) calculated under the optimal values was found to be 0.79 kW·h·g~(-1) which was of the same order of magnitude of those reported in other findings;while it is noteworthy that the electrodes used in our study are of a lower cost.     

腈水解酶重组菌发酵产酶条件的优化及应用

优化了重组菌E.coli BL21(DE3)/pET28b(+)-NIT发酵产腈水解酶的条件,确定最适发酵培养基为:玉米浆粉25g.L-1,酵母浸出汁5g.L-1,NaCl 10g.L-1,Fe3+0.5mmol.L-1,初始pH值7.5;最适诱导产酶条件为:诱导剂乳糖0.5g.L-1,诱导剂加入时间为接种6h后,诱导温度30℃,诱导时间28h,在此条件下产酶量达到6161.46U.L-1。所得菌体用于不对称转化R,S-扁桃腈生成R-(-)-扁桃酸,转化率达92.02%,产物e.e.值达99%。     

响应面法优化微胶囊固定化粘红酵母生产L-苯丙氨酸的工艺条件

以微胶囊固定化粘红酵母为研究对象。考察了粘红酵母转化反式肉桂酸（t-CA）生成L-苯丙氨酸过程中转化体系温度、pH值、CNH＋4／C1-CA对L-苯丙氨酸积累量的影响,并通过响应面法对转化条件进行了优化,得到最佳转化条件为：温度30．75℃、pH值11．58、CNH＋4=4．77mol·L-1、C1-CA=10g·L-1,在该条件下,L-苯丙氨酸积累量为27．5g·L-1。     

离子液体超声-微波协同制取洋葱精油

以离子液体［BMIM〖DK〗］PF₆作为生物催化介质,结果显示洋葱蒜氨酸酶在含25%［BMIM］PF₆催化体系中的活性比在纯缓冲液介质中明显要高,对高温变性作用的抵抗能力也相应增强,但若离子液体浓度过高会对酶催化作用的发挥产生阻碍。以洋葱蒜氨酸为底物,测得离子液体［BMIM］PF₆/缓冲液两相体系中蒜氨酸酶的米氏常数为0.591 mmol·L^-1,最大反应速率为0.316 mmol·L^-1·min^-1,V_max/K_m约为缓冲液单相体系中的两倍。实验还尝试发挥疏水性离子液体［BMIM］PF₆作为生物催化介质和萃取剂的双重功能,并将其与超声-微波协同萃取技术相结合应用于洋葱精油制取的酶解和萃取过程,明显提高了酶解效率和精油得率,将制得的精油经GC-MS分析,共鉴定出22种物质,其中19种为含硫化合物。     

利用肺炎克雷伯氏菌以葡萄糖和磷酸铵盐为底物生产2,3-丁二醇

1 INTRODUCTION Interest in microbial production of 2,3-butanediol has been increasing recently due to the extensive indus-trial application of this product. This colorless and odorless liquid with a high boiling point and a low freezing point is a potential valuable fuel additive. Its heating value is 27.198kJ·g-1, which is quite near the value of ethanol (29.055kJ·g-1). Besides, condensation of diol to methyl ethyl ketone (MEK) coupled with subsequent hydrogenation yields octane isom…     

Fenton氧化法深度处理苇浆造纸废水研究

采用Fenton氧化法对苇浆造纸厂二级生化出水进行深度处理。探讨了废水初始pH、H2O2投加量、FeSO4和PAM用量、反应温度和时间对COD和色度去除效果的影响。结果表明,当体系pH为4、H2O2投加量为10 mmol.L-1、FeSO4投加量为2.5 mmol.L-1、PAM用量为0.75 mg.L-1、反应温度为20℃和时间为40 min时,COD可降至60 mg.L-1以下,色度去除率在90%以上。     

Synthesis of activated carbon from spent tea leaves for aspirin removal

Adsorption capacity of activated carbon prepared from spent tea leaves(STL-AC) for the removal of aspirin from aqueous solution was investigated in this study. Preliminary studies have shown that treatment with phosphoric acid(H_3PO_4) increased removal efficiency of STL-AC. Characterizations on STL-AC revealed excellent textural properties(1200 m~2·g~(-1), 51% mesoporosity), as well as distinctive surface chemistry(1.08 mmol·g~(-1) and 0.54 mmol·g~(-1) for acidic and basic oxygenated groups, pH_(pzc)= 2.02). Maximum removal efficiency of aspirin observed was 94.28% after 60 min when the initial concentration was 100 mg·L~(-1), 0.5 g of adsorbent used,pH 3 and at a temperature of 30 ℃. The adsorption data were well fitted to the Freundlich isotherm model and obeyed the pseudo-second order kinetics model. The adsorption of aspirin onto STL-AC was exothermic in nature(ΔH~Θ=~(-1)3.808 k J·mol~(-1)) and had a negative entropy change, ΔS~Θ(-41.444 J·mol~(-1)). A negative Gibbs free energy, ΔG~Θ was obtained indicating feasibility and spontaneity of the adsorption process. The adsorption capacity of AC-STL(178.57 mg·g~(-1)) is considerably high compared to most adsorbents synthesized from various sources, due to the well-defined textural properties coupled with surface chemistry of STL-AC which favors aspirin adsorption. The results demonstrate the potential of STL-AC as aspirin adsorbent.     

利用响应面法优化出芽短梗霉As3．933产普鲁兰多糖发酵培养基

采用响应面分析法对出芽短梗霉As3．933产普鲁兰多糖的发酵培养基进行优化。首先利用Plackett-Bur-man实验筛选出影响普鲁兰多糖产量的主要因素为酵母膏、（NH4）zSO4和K2HPO4,再利用最陡爬坡实验逼近最大响应区域,最后通过Box-Behnken实验并运用Design-Expert8．0软件优化发酵培养基。确定优化培养基组成为：蔗糖62．5g·L-1,（NH4）2S040．67g·L-1,酵母膏2．84g·L-1,K2HPO47．12g·L-1,NaCl1．25g·L-1,MgS04·7H200．25g·L-1,pH值6．5,优化后的普鲁兰多糖产量达到22．29g·L-1,较初始液体发酵培养基（17．32g·L-1）提高了28．70％。     

Fenton法处理模拟偶氮染料废水的研究

采用Fenton法对模拟偶氮染料废水进行了处理。考察了废水初始pH值、H2O2和Fe2＋投加量、反应时间及反应温度等对模拟染料废水COD去除率的影响。实验结果表明,在甲基红的初始浓度为200mg.L-1,初始pH值为3.0,H2O2和Fe2＋投加量分别为20mmol.L-1和1mmol.L-1,反应温度为50℃,反应时间为60min的条件下,废水中COD的去除率可达83.5%。     

D318阴离子交换树脂对铼（VII）的吸附

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.     

Study on extraction kinetics of α-cyclopentylmandelic acid enantiomers with hydroxyethyl-β-cyclodextrin as chiral selector

In this work,the kinetic study on reactive extraction ofα-cyclopentylmandelic acid(α-CPMA)enantiomers was performed in a Lewis cell using hydroxyethyl-β-cyclodextrin(HE-β-CD)as chiral selector.The enantioselective complexation equilibrium between HE-β-CD andα-CPMA enantiomers was studied by phase solubility method.The important process parameters affecting the initial extraction rate were separately studied and the reaction rate equations were deduced.The optimal conditions for kinetic study were as follows:stirring speed of 75 r·min~(-1),interfacial area of 12.56 cm~2,pH of 2.5,initial HE-β-CD concentration of 0.05 mol·L~(-1),initialα-CPMA concentration of 5 mmol·L~(-1),and temperature of 278 K.The reaction has been found to be first order inα-CPMA and second order in HE-β-CD with the forward rate constants of 2.056×10~(-3)m~6·mol~(-2)·s~(-1)and 1.459×10~(-3)m~6·mol~(-2)·s~(-1)for(S)-α-CPMA and(R)-α-CPMA,respectively.The complexation equilibrium constants were evaluated as 61 L·mol~(-1) and 117 L·mol~(-1)for(S)-α-CPMA and(R)-α-CPMA,and the intrinsic enantioselectivity is estimated as 1.92.     

坡柳皂苷对马铃薯块茎蛾产卵选择性的影响研究

为探明坡柳皂苷对马铃薯块茎蛾产卵行为的影响,以开发生物农药,在室内采用选择性产卵实验方法分别测定了5种不同质量浓度的坡柳皂苷对马铃薯块茎蛾产卵选择性的影响.结果表明：从产卵量来看,各处理组与对照之间差异极显著,其中10.000 g·L-1处理组与对照的落卵量差别较大、卡方位达到131.120,0.080 g·L-1处理组次之、卡方值为92.395,2.000 g·L-1处理组与对照的落卵量差别较小、卡方位仅为24.599;从驱避效果来看,当坡柳皂苷浓度为10.000 g·L-1、0.080 g·L-1时驱避效果较好,驱避引诱指教分别为0.1891、0.1881,但是当坡柳皂苷浓度为0.400 g·L-1时,无驱避效果,驱避引诱指数为-0.1056,其它处理组驱避效果较弱;从整体上来看,坡柳皂苷对马铃薯块茎蛾产卵有驱避作用;坡柳皂苷对马铃薯块茎蛾的交配影响较小,0.016 g·L-1、0.080 g·L-1、0.400 g·L-1、2.000g·L-1、10.000 g·L-1处理组的交配率分别为60.00％、67.50％、67.50％％、67.50％、72.50％.表明,坡柳皂苷对马铃薯块茎蛾具有一定的产卵驱避作用,有望成为一种绿色环保的马铃薯块茎蛾产卵驱避剂.     

微流控芯片测定盐酸倍他司汀片中盐酸倍他司汀

采用微流控芯片非接触电导检测法测定片剂中的盐酸倍他司汀.采用1 mmol·L-1HAc和2 mmol·L-1NaAc(pH 4.5)为缓冲溶液,0.1 mmol·L-1SDS为添加剂,以2.40kV分离电压,10 s进样时间,盐酸倍他司汀2 min内可实现快速分离和检测.盐酸倍他司汀的线性范围为10～140μg·mL-...     

耐热石油降解混合菌群的降解性能研究

针对极端环境下石油污染土壤的生物修复,从克拉玛依油田石油污染土壤中筛选获得一组最适生长温度为45～55℃、最高耐受温度为75℃的耐热石油降解混合菌群KLO-8,该混合菌群由4株单菌组成,16S rDNA序列分析鉴定表明,其中3株为芽孢杆菌(Bacillus sp.)、1株为地芽孢杆菌(Geobacillus sp.)....     

巨大芽孢杆菌Bacillus megaterium NCIB8508蔗糖磷酸化酶生物催化合成α-熊果苷的研究

利用巨大芽孢杆菌Bacillus megaterium NCIB 8508蔗糖磷酸化醇生物催化合成α-熊果苷.考察了缓冲溶液pH值、缓冲溶液浓度、对苯二酚浓度、反应物摩尔比及反应时间等因素对反应的影响.结果表明,以湿菌体50 mg·mL-1破碎细胞粗酶液催化合成α-熊果苷,在pH值为6.5的30 mmol·L-1磷酸盐...     

Tailoring polymeric composite gel beads-encapsulated microorganism for efficient degradation of phenolic compounds

Phenol and its derivatives are highly toxic pollutants in industrial wastewater for the ecological environ-ments, so there is essential attention to develop effective means of removing these harmful substances from water. In this work, the microorganism was immobilized into polymeric composite gel beads pre-pared by the effective recombination of natural abundant chitosan (CS) and industrial polyvinyl alcohol (PVA) for treating phenolic compounds. The degradation rate of 99.5％ can be achieved to treat 100 mg·L-1 of phenol at 30 ℃ using the fresh resultant immobilized microorganism, where only 21.1％degradation rate was obtained by the free microorganism under the identical conditions. The recycling experiments of repeated 90 times to treat 100 mg·L-1 of phenol displayed that the degradation rate of phenol was stable to 99％with the appearance of beads unchanged significantly, indicating the immobi-lized microorganism possessed excellent operating stability. Moreover, while the phenol derivatives of 100 mg·L-1 were treated catalytically including p-methylphenol, catechol, and o-aminophenol for 24 h by the immobilized microorganism, the degradation rates were all above 95％. The immobilized microor-ganism into PVA-CS polymeric composite with excellent operating stability and degradation activity would provide a feasible solution for treating phenolic compounds in water in industrial applications.     

腈水解酶重组茵发酵产酶条件的优化及应用

摘要：优化了重组茵E．coliBL21（DE3）／pET28b（＋）-NIT发酵产腈水解酶的条件,确定最适发酵培养基为：玉米浆粉25g·L-1,酵母浸出汁5g·L-1,NaCl10g·L-1,Fe3＋0．5mmol·L-1。初始pH值7．5;最适诱导产酶条件为：诱导剂乳糖0．5g·L-1,诱导剂加入时间为接种6h后,诱导温度30℃,诱导时间28h,在此条件下产酶量达到6161．46U·L-1。所得茵体用于不对称转化R,S-扁桃腈生成R-（-）-扁桃酸,转化率达92．02％,产物e．e．值达99％。     

EDTA—NaOH—Fe2（SO4）3改性沸石除氟性能静态实验研究

为提高天然沸石除氟性能,比较了不同方法改性的沸石对水样的除氟效果,并通过静态吸附实验对其中效果最好的EDTA-NaOH—Fe2（SO4）3改性沸石进行了除氟条件优化。结果表明;以EDTA-NaOH—Fe2（SO4）3改性沸石除氟时,EDTA、NaOH和Fe2（SO4）3的最佳浓度分别为0．2mol·L-1、1．0mol·L-1和1．0mol·L-1,最佳粒径、投料量、水样pH值、吸附时间和水样温度分别为60目、5．0g·（100mL）-1、7．0、60min和50℃。含氟20．0mg·L-1的高氟水经改性沸石处理2次后,F-浓度降至1．0mg·L-1以下,符合国家生活饮用水标准。