外源基因在原核生物和真核生物中的表达(英文)     

雷正玉  张晓 《农业科学与技术》2014,(5):854-857

[目的]研究外源基因在原核生物和真核生物中的表达。[方法]将带有目的基因的表达载体pTYB2-WF转化大肠杆菌ER2566,用IPTG诱导植酸酶基因表达。用SDS-PAGE验证植酸酶融合蛋白表达情况,并进一步对融合蛋白进行纯化。用毕赤酵母表达系统表达植酸酶基因phyA;构建酵母整合载体pPIC9K-phyA,转化毕赤酵母GS115,构建工程菌GS115-pPIC9K-phyA。[结果]在甲醇的诱导下表达植酸酶,经酶活力的测定,其植酸酶活力达7.3μ/ml,构建了毕赤酵母工程菌GS115-pPIC9K-phyA。[结论]甲醇酵母表达机制在分子生物学以及工业应用领域发挥作用。  相似文献   

植酸酶及其应用研究   总被引：1，自引：0，他引：1  

许钦坤  赵翠燕 《安徽农业科学》2007,35(2):366-367

综述了植酸酶的来源、基因工程和蛋白质工程的研究进展,并对其应用进行了展望.  相似文献   

植酸酶后处理技术对植酸酶理化特性的影响     

姜建宏  高志璞  郭宝林 《饲料博览》2006,(12):1-4

植酸酶后处理技术常采用酶的固定化技术,通过物理吸附作用将酶固定在载体上形成致密微丸植酸酶;或通过将无毒无害的耐热物质包被在微丸植酸酶的表面,形成包被型植酸酶,进一步提高了酶的稳定性和抗逆性,使植酸酶的应用效果更加明显。试验比较了普通植酸酶、微丸植酸酶及包被植酸酶单体保存及添加到饲料中保存的稳定性,并且分别考察了他们对高温、高湿的抗性。结果说明微丸植酸酶、包被植酸酶无论是单体还是添加到饲料中,都比普通植酸酶具有明显的稳定性,对高温、高湿的抗性也强。  相似文献   

植酸酶及其在饲料工业中的应用     

董瑞玲 《邯郸农业高等专科学校学报》2001,18(4):22-24

本概述了植酸的抗营养作用，重点综述了植酸酶的来源、特性、作用及在饲料工业中的应用。  相似文献   

非淀粉多糖酶和植酸酶对肉仔鸡生长性能和养分利用性的影响   总被引：14，自引：1，他引：13  

彭玉麟  呙于明 《中国畜牧杂志》2002,38(6):3-5

以 8 8 8只艾维因肉仔鸡为试验动物 ,研究添加非淀粉多糖酶 (40 0mg/kg)和植酸酶 (30 0mg/kg)对肉仔鸡的生长性能和养分利用性的影响。试验结果表明 :玉米 -菜粕 -豆粕日粮中添加非淀粉多糖酶 (减少 1.4 %AME)和植酸酶(减少 0 .0 8%非植酸磷 ) ,甚至再减少 0 .0 1%赖氨酸 ,都不会显著影响肉仔鸡 4 2日龄体重 (P >0 .0 5 ) ,但饲料转化率得到改善 ,死亡率降低。添加非淀粉多糖酶可提高AME和TME(P >0 .0 5 )和氮沉积量和氮表观消化率 (P >0 .0 5 )。非淀粉多糖酶对总磷的消化率没有显著影响 (P >0 .0 5 ) ,但同时添加非淀粉多糖酶和植酸酶 (减少 0 .0 8%非植酸磷 ) ,可显著提高总磷的表观消化率和真消化率分别为 16和 16 .1个百分点 (P <0 .0 5 )。  相似文献   

Phytase activity, phytate, iron, and zinc contents in wheat pearling fractions and their variation across production locations   总被引：2，自引：0，他引：2  

Z.H. Liu  H.Y. Wang  X.E. Wang  G.P. Zhang  P.D. Chen  D.J. Liu   《Journal of Cereal Science》2007,45(3):319-326

Pearling is an effective method for evaluating the distribution of chemical components in wheat grain. Twelve pearling fractions (P₁–P₁₂) of wheat grain were obtained using two rice polishers for 10 cultivars (six soft red wheats and four hard white wheats) grown at two locations with different environmental conditions in Jiangsu Province, China. The results show that the effects of cultivar, location, and pearling on wheat flour phytase activity, phytate, iron, and zinc contents were all significant, with pearling having the greatest effect. All the four components showed a diminishing trend as pearling progressed from the outer layers to the inner part of wheat grain. Generally, the P₂ fraction (the outer 4–8% layer of wheat grain) had the highest phytase activity and phytate and iron contents, whereas the P₁ fraction (the outer 0–4% layer) ranked the highest for zinc content. Growing location had a large influence on grain phytase, phytate, and iron, but the differences between locations decreased as pearling level increased.  相似文献   

Phytase activity in extracts of flour and bran from wheat cultivars: enhanced extractability with β-glucanase and endo-xylanase     

Moses Okot-Kotber  Kwon-Joong Yong  Katherine Bagorogoza  Allan Liavoga 《Journal of Cereal Science》2003,38(3):307-315

Phytase (EC 3.1.3.8) hydrolyzes phytic acid to myo-inositol and inorganic phosphate through intermediate myo-inositol phosphates. Microbial phytase has been employed to minimize the negative effects of phytic acid in cereal-based feeds, however, other sources such as wheat, would be natural alternatives. Investigations were therefore carried out to determine the levels of phytase activity in various cultivars and how the extraction of the enzyme may be enhanced using buffers fortified with glycanases. We screened 23 cultivars and the results showed that bran from hard white wheat cultivars had relatively lower levels of activity, ranging from about 1.5 to about 2.5 FTU/g bran, whereas hard red wheat cultivars had much higher levels, ranging from approximately 2 to 5.5 FTU/g bran. These levels were greatly enhanced, up to 5-fold, when extraction buffer contained a commercial preparation consisting of β-glucanase (EC 3.2.1.6) and endo-xylanase (EC 3.2.1.8) (Natugrain) (opt 1%) from BASF. The effect of glycanases was concentration and cultivar dependent, but not significantly influenced by temperature exposure of mixtures of samples with extraction buffers prior to extraction. Relative increases were more substantial in hard white than in hard red wheat cultivars. The additional value of supplementing grain-based diets with glycanases for monogastric animals is discussed.  相似文献   

Effects of a novel bacterial phytase expressed in Aspergillus Oryzae on digestibility of calcium and phosphorus in diets fed to weanling or growing plgs     

Ferdinando Nielsen  Almeida Rommel  Casilda Sulabo  Hans Henrik  Stein 《畜牧与生物技术杂志(英文版)》2013,(2):102-111

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转植酸酶基因玉米phyA2基因标准质粒分子构建及其检测应用     

张广远  孙红炜  李凡  杨淑珂  路兴波  赵蕾 《作物学报》2013,39(8):1501-1506

质粒分子以其良好的适应性被较多地用作转基因标准材料的替代品。本文根据转植酸酶基因玉米phyA2基因设计引物与探针,并构建了一种包含phyA2基因片段(243 bp)和内标基因片段(178 bp)的质粒分子pPZ。选取不同转基因模板DNA作用于phyA2特异性引物,PCR结果显示只有转植酸酶基因玉米出现131 bp的目的条带;选取不同转基因作物检测体系作用于质粒分子pPZ,只有以pPZ DNA为模板时出现目的条带(131 bp和88 bp)。同时采用pPZ质粒分子和转基因玉米阳性基因组DNA为标准对4个转植酸酶基因玉米混合样品(3.0%、1.0%、0.5%和0.1%)进行定量检测,t检验表明,2种标准产生的斜率、线性相关系数和定值结果没有显著差异。这些结果表明,pPZ质粒分子可以作为转植酸酶基因玉米替代品用于定性和定量检测。  相似文献   

Large variability exits in phytase levels among Indian wheat varieties and synthetic hexaploids     

Sewa Ram  Anukriti Verma  Shikha Sharma 《Journal of Cereal Science》2010,52(3):486

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