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枯草芽孢杆菌中怀植酸酶的纯化和酶学性质 总被引:19,自引:0,他引:19
从土壤中分离到了产中性植酸酶的枯草芽孢杆菌菌株并对所产植酸酶进行了分离纯化,此中性植酸酶的反应最适pH为7.5,最适温度为55度,在37度下以植酸钠为底物的Km值为0.19mmol/L,植酸酶活性依赖Ca^2 的存在,酶蛋白的分子量大小约为45kD,纯酶蛋白N端序列为Lys-His-Lys-Leu-Ser-Asp-Pro-Tyr-His-Phe-Thr。 相似文献
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枯草芽孢杆菌中性植酸酶的纯化和酶学性质 总被引:1,自引:0,他引:1
从土壤中分离到了产中性植酸酶的枯草芽孢杆菌菌株并对所产植酸酶进行了分离纯化。此中性植酸酶的反应最适 pH为 7 5,最适温度为 55℃ ,在 37℃下以植酸钠为底物的Km值为 0 1 9mmol/L ,植酸酶活性依赖Ca2 +的存在。酶蛋白的分子量大小约为 45kD ,纯酶蛋白N端序列为Lys His Lys Leu Ser Asp Pro Tyr His Phe Thr。 相似文献
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植酸酶产生菌的选育及固态产酶条件研究 总被引:11,自引:0,他引:11
植酸酶催化植酸,并将其盐类水解成肌醇和磷酸,因此植酸酶的使用可以提高植酸磷的吸收利用率,降低饲料成本,同时还可保护生态环境.经分离和亚硝基胍诱变选育,得到一株植酸酶高产菌株绿色木霉LH374,并对该菌株固态发酵产植酸酶的条件和扩大生产进行了研究.结果表明,固态发酵的最佳条件:稻草和米糠的比例为8:2,培养基起始pH为6.5,最适温度为30℃,最适培养时间为96 h,含水量为60%,硫酸铵的流加量为2%.绿色木霉LH37在上述最适条件下生产植酸酶平均可达1 580 U·g-1. 相似文献
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黑曲霉WY-6植酸酶的表达、纯化及性质研究 总被引:1,自引:0,他引:1
目的:表达黑曲霉WY-6植酸酶基因及研究重组酶的性质。方法:通过PCR方法从黑曲霉WY-6基因组中扩增出植酸酶基因,并将该基因表达在毕赤酵母中,再利用蛋白质分离纯化技术对重组酶进行纯化,并测定其性质。结果:黑曲霉WY-6植酸酶基因成功表达在毕赤酵母中,重组植酸酶经饱和硫酸铵分级沉淀、超滤和阴离子交换层析步骤后得以纯化,纯化后的植酸酶比活力为147U/mg,分子量为67kDa,两个最适pH分别为3.0和5.5,最适温度为55℃,与胃蛋白酶以0.01的比率(胃蛋白酶/植酸酶,wt/wt)混合作用2h后仍保留70.9%残余活力。结论:获得了具有商业应用潜能的基因工程植酸酶。 相似文献
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植酸酶产生菌黑曲霉N14的诱变选育及其基因分析 总被引:1,自引:0,他引:1
以植酸酶产生菌黑曲霉03214为出发菌株,经紫外线和亚硝基胍诱变,获得了产酶活性较出发菌株提高了22.3%,达422IU/ml发酵液的突变菌株黑曲霉N14,其最适pH值为2.5,最适温度为50℃。通过对黑曲霉N14植酸酶phyA基因进行PCR扩增,获得了一条长约1.5kb的特异性产物。以pMD18-T为载体,构建了含有目的基因片段的重组质粒。DNA序列测定表明,目的基因片段含有植酸酶phyA基因的完整序列(GenBank Accession:AY426977),phyA基因全长1506bp,其中包含一段长102bp的内含子,编码467个氨基酸,有10个潜在的糖基化位点,5’端有一编码19个氨基酸的信号肽序列。实验结果为植酸酶基因工程菌的构建奠定了基础。 相似文献
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枯草芽孢杆菌WHNB02植酸酶的酶学性质研究 总被引:1,自引:0,他引:1
从118份样品中分离到1株产植酸酶的枯草芽孢杆菌(Bacillus subtilis,WHNB02),其发酵液经乙醇沉淀、硫酸铵分级沉淀及Sephadex G-100柱层析等步骤后分离纯化了该酶,纯化倍数约为31.5倍,回收率为13.0%。该酶为单体酶,SDS-PAGE测得的分子量约为43ku,以植酸钠为底物的Km值为0.5mmol/L,酶反应的最适温度为60℃,80℃作用10min酶活保存61%,最适pH为7.0,在pH6.0~10.0范围内稳定,酶活性及稳定性都需Ca2 存在。EDTA、Mn2 、Ba2 (5mmol/L)对酶活具有很大的抑制作用。 相似文献
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PEERS FG 《The Biochemical journal》1953,53(1):102-110
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Secreted phytase activities of yeasts 总被引:11,自引:0,他引:11
The enzyme phytase dephosphorylates phytin (inositol hexaphosphate), a major phosphate reserve in plants. We found that a large number of yeast species secreted a phytase. Several species were identified as high phytase producers. The yeast enzymes had an optimal activity at pH 4-5 and generally a very high optimal temperature, ranging from 60 degrees C to 80 degrees C. 相似文献
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A. I. Akhmetova Ch. Nyamsuren N. P. Balaban M. R. Sharipova 《Russian Journal of Bioorganic Chemistry》2013,39(4):384-389
From cell lysates of a recombinant Escherichia coli strain, Bacillus ginsengihumi phytase has been isolated and studied for the first time. The enzyme has been purified to homogeneity, and its primary structure has been determined. It has been concluded that phytase belongs to the class of β-propeller phosphatases. The molecular weight of the protein is 41 kDa, and pI is 4.8. Some physicochemical properties of the enzyme have been investigated. 相似文献
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The extracellular activity ofAspergillus niger phytase at the end of the growth phase was 132 nkat/mL in a laboratory bioreactor. The purified enzyme has molar mass approximately
100 kDa, pH optimum at 5.0, temperature optimum at 55°C and high pH and temperature stability. TheK
m for dodecasodium phytate, calcium phytate and 4-nitrophenyl phosphate are 0.44, 0.45 and 1.38 mmol/L, respectively. The enzyme
is noncompetively inhibited by inorganic monophosphate (K
i=2.85 mmol/L) and by Cu2+, Zn2+, Hg2+, Sn2+, Cd2+ ions and strongly by F− ones; it is activated by Ca2+, Mg2+ and Mn2+ ions. The substrate specificity of phytase is broad with the highest affinity to calcium phytate. 相似文献
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Over 200 fungal strains were screened for phytase production using a two-step procedure. The best strain, an Aspergillus sp., produced phytase almost equally active at both pH 5.0 and 2.5. Synthesis of the enzyme was limited by content of inorganic phosphorus above 20mg/dm. 相似文献
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Some properties of phytase from cotton plant seeds were studied. The phytase activity was shown to increase during seed germination. The enzyme from cotton sprouts is not activated by Ca2+, Mg2+ and K+ and has the pH optimum of 5,0 and temperature optimum of 50 degrees. The molecular weight of the enzyme as determined by gel-filtration is 36000. 相似文献