酯酶

ABSTRACT Immobilized penicillin acylase (from E.coli) was used to catalyze 7 phenylacetamido 3 E propenyl cephalosporanic acid hydrolyzation into 7 amino 3 E propenyl cephalosporanic acid. Then, trans APRA was acylated with hydroxyethyl ester of 4 hydroxy D phenylglycine to obtain trans cefprozil.

以7 苯乙酰氨基 3 E 丙烯基 3 头孢菌素 4 羧酸为原料，在青霉素酰化酶作用下，首先酶法水解得到3 E 丙烯基 3 头孢菌素 4 羧酸，过滤固相酶，滤液调pH分离得到反式APRA固体；在青霉素酰化酶作用下，反式APRA再与对羟基苯甘氨酸乙二醇酯缩合，得到反式头孢丙烯；酶法合成所得的产品与进口反式头孢丙烯对照品一致。

Compared with the previous method, the improved route can provide directly a spheroid form of immobilized lipase particles of which the size can be controlled by adding non-ionic surfactants during the preparation process so as to increase the recovery rate of enzyme as well as decrease the external diffusional restriction which can diminish the enzyme activity. The improved method can also alter the hydrophobicity and microstructure of the immobilized enzyme matrix by changing the molar ratios of different alkoxyl silanes so as to enhance the enzyme activity by a"surface active effect"and eliminating the internal diffusional restriction.

与前人的制备方法相比，改进的方法可直接制得球形的固定化酶颗粒，而且颗粒的大小可以通过在制备过程中加入非离子型表面活性剂加以控制，从而可以提高固定化过程的酶活回收率和减小外扩散效应对酶的表观催化活力的影响；改进的方法还可以通过改变原料硅氧烷的种类及配比来改变最终制得的固定化载体的疏水性质及微观结构，从而通过对脂肪酶的&界面活化&作用和减小内扩散效应提高固定化脂肪酶的表观酯化活力。

The recombinant enzyme hydrolyzed p-nitrophenyl esters but not tributyrin and tricaprylin, and exhibited the highest specific activity (1.1 μmol min-1 mg-1) to p-nitrophenyl caprylate.

SsoPEst不水解三酰甘油酯，可以水解对硝基苯酚酯，对对硝基苯酚辛酯水解活力最高，为1.1 μmol min-1 mg-1，催化对硝基苯酚酯水解的最适pH为5.5，最适温度为80 °C，酶溶液置于80 °C 热处理1小时仍有60 %活力。

The baseline-sensitivity of Cladosporium fulvum to azoxystrobin was established,the present resistance situation of C.fulvum in different areas to Azoxystrobin was studied,and the resistant risk of C.fulvum to azoxystrobin was also assessed in laboratory.Resistance mechanism of C.fulvum to azoxystrobin was studied preliminarily.The results are shown as follows.

本试验建立了番茄叶霉病菌对嘧菌酯的敏感性基线：研究了目前不同地区的番茄叶霉病菌对嘧菌酯的抗药性现状；进行了番茄叶霉病菌对嘧菌酯的室内抗药性风险评估；对番茄叶霉病菌对嘧菌酯的抗性与苯丙氨酸解氨酶的活性进行了初步探讨，获得了如下研究结果： 1。

The inhibitory potency of geranyl gallate is as about six times as that of lauryl gallate on mushroom tyrosinase. Lauryl gallate was determined to be an uncompetitive inhibitor while geranyl gallate belongs to be a mixed-type inhibitor.

没食子酸香叶酯对蘑菇酪氨酸酶的抑制作用比没食子酸十二烷基酯更强，没食子酸十二烷基酯表现为反竞争性抑制类型，而没食子酸香叶酯表现为混合型抑制类型。

A sort of lipase producing strain with relatively high esterification rate of ethyl hexanoate was obtained was isolated from Lavandula vera L. root soil. The strain was identified and named as Arthrobacter Y-605. The optimal lipase producing conditions of the strain was indicated in details and the results were as follows:2% maize meal, 1% soy flours, 0.1% urea, 0.05% MgSO4, 0.1% K2HPO4, 0.15% KCl.

以有机相中合成酶活为指标，通过对薰衣草根际土壤产脂肪酶菌株的筛选，获得了一株在有机相中合成己酸乙酯转化率相对较高的细菌Arthrobacter Y-605，其己酸乙酯转化率为67.53%。

We use plate to check the lipase activity ,the lipase activity is very low, Compared to the wild type , the mutant could not form the clear halo on the olive oil plate but tributyrin plate, it showed that the 227 th Serine was essential for the lipase activity.

与野生型相比，突变体脂肪酶的酶活很低，不能在橄榄油平板上形成透明圈，但可以在以三丁酸甘油酯为底物的平板上形成透明圈，表明第227位丝氨酸可能对脂肪酶酶酶活具有重要影响。

Fat tissue is hydrolyzed and released fatty acid as well triolein by lipase; on the other hand, high fat diet can't be directly absorbed across the intestinal mucosa.it must be firstly decomposed into one 2-monoglyceride and two free fatty acids by pancreatic lipase ,which is delivered into the lumen of the gut as a constituent of pancreatic juice.

脂肪酶能够使体内的多余脂肪组织分解成三酸甘油酯，另一方面，人体摄入高脂肪食物，并不能直接被小肠粘膜吸收，而是先被小肠内的胰脂肪酶分解成2-单酸甘油酯和两个游离脂肪酸，然后和胰液一起被运输到肠道的内腔被吸收。

Enzymatic synthesis of glycerides directly from glycerol and polyunsaturated fatty acids was studied.

研究了在脂肪酶N435的催化作用下，游离多不饱和脂肪酸与甘油酯化合成的工艺，分别考察了甘油与脂肪酸的质量比、反应时间、反应温度、酶用量、初始加水量等单因素对酯化效果的影响。

Application of reverse micella enzyme system in oil industry;2. Synthesis of ethyl oleate catalyzed by Lipex lipase in AOT/isooctane reverse micella r system was studied.

在二-(2-乙基己基)琥珀酸酯磺酸钠和异辛烷构建的逆胶束体系中，以Lipex脂肪酶为催化剂，合成了油酸乙酯，考察了各影响因素对其产率的影响，并进行了脂肪酶紫外荧光检测和体系粒度分析。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。