共查询到16条相似文献,搜索用时 54 毫秒
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米黑根毛霉脂肪酶基因在毕赤酵母中的高效表达 总被引:4,自引:0,他引:4
脂肪酶是主要工业用酶制剂之一,在食品、洗涤剂和制药等领域广泛应用。将编码米黑根毛霉(Rhizo-mucor miehei)脂肪酶RML的基因克隆到pPIC9K载体中,构建了分泌型表达载体pPIC9K-RML,载体经线性化后转化Pichia pastorisGS115,G418梯度筛选获得了分泌表达RML的重组毕赤酵母工程菌,SDS-PAGE分析显示表达的脂肪酶分子量大小与预期一致。初步研究表明,重组脂肪酶最适温度为40℃,最适pH值为8.0,以橄榄油为底物时,发酵上清液酶活最大可达102 U/mL,表明构建的重组毕赤酵母工程菌具有较好的工业化生产潜力。 相似文献
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为实现内切葡聚糖酶和木聚糖酶在毕赤酵母中的共分泌表达,进而降低酶制剂的生产成本,构建含木聚糖酶基因的重组表达载体pPICZαA-Aoxyn11A,经SacI线性化后,电转化至含内切葡聚糖酶基因Aucel12A的重组毕赤酵母GSC7中,获得双重重组毕赤酵母GSCX8。经甲醇诱导表达后,GSCX8发酵上清液中内切葡聚糖酶和木聚糖酶的活性分别为47.77IU/mL和192.71IU/mL,为单独表达菌株GSC7和GSX5的85%和80%。酶学性质分析显示,内切葡聚糖酶的最适pH为4.0,在pH3.0~8.5稳定;最适温度为50℃,在60℃以下稳定。木聚糖酶的最适pH为5.5,在pH3.0~10.0稳定;最适温度为55℃,在50℃以下稳定。GSCX8遗传稳定性测试结果表明,内切葡聚糖酶和木聚糖酶在毕赤酵母中实现了稳定的共表达。 相似文献
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从高产糖化酶的黑曲霉的cDNA文库中筛选出糖化酶基因,并研究在毕赤酵母中的表达情况。运用RT-PCR从黑曲霉cDNA文库中克隆糖化酶基因的cDNA片段与载体pPIC9K相连,构建重组载体,电转化毕赤酵母GS115,筛选阳性克隆并进行研究。阳性克隆在MM培养基中发酵72 h和1%的甲醇的诱导的情况下,重组毕赤酵母产生的糖化酶酶活最大为15.6 U/mL。测定结果显示,其糖化酶大小为1 908 bp,编码636个氨基酸残基组成的蛋白质。经柱分离纯化其发酵上清液后,用SDS-PAGE电泳方法,测得分子质量大约为80 ku。黑曲霉糖化酶基因在毕赤酵母GS115中成功得到了表达。 相似文献
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本文通过RT-PCR从Coprinopsis cinerea okayama7#130中克隆得到laccase1,应用SignalP3.0Server软件分析其氨基酸序列后设计不含信号肽序列的新引物扩增得到不含信号肽的漆酶基因1(lac1),并构建重组酵母表达载体pPIC9K-lac1,电击转化毕赤酵母GS1115并用甲醇诱导表达,之后研究重组酶的酶学性质。克隆得到的laccase1全长为1593bp,编码530个氨基酸,其中信号肽包含18个氨基酸。SDS-PAGE显示重组蛋白大小约为65KDa。酶学性质研究表明,该酶最适反应温度为45℃,最适pH为4.3。重组漆酶在45℃保存3h后活性基本保持不变,在pH4.0~10.0的范围内稳定性较好。成功分泌表达的漆酶活力达到1.108U/mL。 相似文献
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Hang H Mu W Jiang B Zhao M Zhou LL Zhang T Miao M 《Journal of Bioscience and Bioengineering》2012,113(1):55-57
An ultrafiltration membrane bioreactor was used for the production of DFA III from enzymatic conversion of inulin. Compared with the traditional batch reactor, the productivity and purity of DFA III could be markedly enhanced and product inhibition was removed and IFTase could be continuously used for six runs in the UF membrane bioreactor. When the substrate concentration was 100 g/L, the concentration of DFA III was about 78.4 g/L, while the productivity and purity of DFA III could attain about 2385 and 92%, respectively. 相似文献
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Nakakubo H Fukuyama H Nakajima M Imada T Uno S Shiota N Takai S Miyazaki M Nakamura N 《Yeast (Chichester, England)》2000,16(4):315-323
We succeeded in expressing in a Pichia pastoris (P. pastoris) host a cDNA encoding a mature human chymase (h-chymase) which was secreted directly into the culture medium. Recombinant human heart chymase (rh-chymase) was purified from the culture medium via a single one-step heparin-agarose column chromatography tracing, using succinyl-Ala-Ala-Pro-Phe-para-nitroanilide (Suc-AAPF-pNA) hydrolysing activity. On SDS-polyacrylamide gel electrophoresis (SDS-PAGE), the rh-chymase showed a diffused protein band with molecular weight of 32-37 kDa. After deglycosylation, however, rh-chymase changed to a sharp protein band with molecular weight 28 kDa, which is equal in size to deglycosylated h-chymase. The rh-chymase had an activity to convert one of the natural substrates, angiotensin I, to angiotensin II. Double reciprocal plot analysis revealed that the K(m) value ofrh-chymase against Suc-AAPF-pNA was approximately 5.1 mM, which is close to that of purified h-chymase. 相似文献
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Zhao M Mu W Jiang B Hang H Zhou L Zhang T 《Journal of the science of food and agriculture》2011,91(15):2715-2721
BACKGROUND: Difructose anhydride (DFA) III is a natural and low‐calorie sweetener. It stimulates the absorption of calcium and other minerals. Inulin fructotransferase (IFTase; EC 4.2.2.18), catalysing inulin hydrolysis to DFA III, is considered to be the most promising enzyme for the production of DFA III. RESULTS: IFTase gene from Arthrobacter aurescens SK 8.001 was cloned and sequenced. Transformant with native IFTase signal peptide was a useful system for extracellular over‐expression of IFTase, and its extracellular IFTase activity reached 81.0 U mL?1. This value was 4.1‐fold of that obtained with A. aurescens SK 8.001 for IFTase production. The recombinant IFTase was purified to electrophoretical homogeneity and characterized. The enzyme showed maximum activity at pH 6.0 and 55 °C, and retained 81.3% of its initial activity after incubation at 60 °C for 4 h. CONCLUSION: IFTase gene from A. aurescens SK 8.001 was cloned, sequenced and over‐expressed in E. coli. IFTase was reported for the first time to be over‐expressed extracellularly. The recombinant IFTase was purified and characterized, and shown to be a good candidate for potential application in DFA III production. Copyright © 2011 Society of Chemical Industry 相似文献
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Meng Zhao Bo Jiang Hua Hang Yapeng Fang Fatang Jiang Glyn O. Phillips 《European Food Research and Technology》2013,236(6):991-998
Inulin fructotransferase (IFTase; EC 4.2.2.18) has received great attention mainly due to its application in producing difructose anhydride III (DFA III), which is a novel functional sweetener. The object of this study was to investigate the induction of IFTase in Arthrobacter aurescens SK 8.001 with various carbon sources, especially inulin and DFA III. IFTase production could be significantly promoted by the supplement of inulin (5–50 g/L) and DFA III (5–20 g/L). Inulin at high initial concentrations gave no indication of catabolite repression, whereas 30 and 40 g/L DFA III intensely inhibited cell growth and IFTase activity. No fructose was detected in broth throughout the cultivation with inulin, and inulin was converted into DFA III and minor fructooligosaccharides. And when DFA III was the carbon source, DFA III was the only sugar detected in the broth. In conclusion, both DFA III and inulin are effective for IFTase induction, and inulin with higher IFTase activity proved to be a more potent inducer. 相似文献
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《食品与发酵工业》2019,(19):58-62
人工设计合成木聚糖酶,为木聚糖酶分子改造研究提供新思路。采用合成生物学思路,以黑曲霉XZ-3S木聚糖酶Xyn ZF-2基因序列为基础,将N端48个氨基酸替换成Ev Xyn11 N端的34个氨基酸;引入芳香族氨基酸P9Y和H14F;在C端引入二硫键Cys38-Cys191;α-螺旋及cord区域分别引入疏水性氨基酸K164M、G166A、N160I、V111A以及G109A,设计杂合酶Xyn ZL。基因全合成后,构建毕赤酵母重组表达质粒p PIC9K-ZL,将其转化酵母菌GS115,对工程菌GS115-XynZL进行单因素发酵条件优化及重组酶酶学性质测定。最佳发酵培养基为土豆培养基,最佳诱导温度为28℃,最佳种龄为20 h,最佳诱导时间为168 h,最佳诱导起始pH值为6. 5,甲醇诱导最佳体积分数为15 mL/L。重组酶酶学性质显示:最佳反应温度为55℃,最适pH值为5. 0,杂合酶Xyn ZL在毕赤酵母中表达后具有特定性质和功能,其设计方法拓宽了木聚糖酶分子改造研究的思路。 相似文献