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南极假丝酵母脂肪酶发酵条件优化及酶学性质 总被引:7,自引:0,他引:7
分别用摇瓶和15L发酵罐,对南极假丝酵母产胞外脂肪酶的培养基成分和操作条件进行了实验研究。得到最优的培养基组成为:豆粉40g/L,淀粉15g/L,豆油5mL/L,K2HPO4g/L,MgsO4·7H2O1g/L,Tween-800.1%,酵母膏5g/L;操作条件为:温度24℃,初始pH值为6.0,通气量为10.0L/min。在此培养条件下,发酵周期缩短至54h。由15L发酵罐生产的酶液酶活达到19.2U/mL。酶液在pH值为4.0~6.0和7.5~9.0范围内较稳定,其最适宜pH值范围为6~8.5;70℃时酶的催化活性最大.在40~70℃的温度范围内保持1h后残留酶活为60%。 相似文献
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硫酸铵-丙酮协同沉淀法纯化南极假丝酵母产脂肪酶 总被引:2,自引:0,他引:2
采用硫酸铵-丙酮协同沉淀法,对南极假丝酵母产脂肪酶(CALB)进行了分离纯化研究.经正交实验确定纯化工艺为:向酶液中加入硫酸铵至饱和度45%的同时加入0.3倍酶液体积的丙酮;离心后再向上清液中加入硫酸铵至饱和度75%,分相后,相界面处沉淀即为脂肪酶粗品.经分离纯化后,酶活回收率为54%、纯化倍数为2.72. 相似文献
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培养条件对产朊假丝酵母合成谷胱甘肽的影响 总被引:11,自引:0,他引:11
考察了培养基组成,培养条件对产朊假丝酵母生长和谷胱甘肽合成的影响,包括不同碳源,氮源及其浓度,pH,装液量,接种量等。确定以葡萄糖、磷酸氢二铵作为碳源和氮源,较佳浓度分别为20g/L和3g/L,接种量为10%,在20 g/L 的糖 浓度时获得的谷胱甘肽总量可达74mg/L,胞内含量为1.4%左右。此外还研究了三种前体氨基酸和ATP的加入量,加入时间对发酵的影响。 相似文献
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固定化假丝酵母脂肪酶催化合成辛酸甘油酯 总被引:2,自引:0,他引:2
以自制固定化假丝酵母脂肪酶作为催化剂,研究了无溶剂体系中辛酸和甘油直接酯化合成辛酸甘油酯的反应条件。考察了酶的种类、底物的物质的量之比、温度、酶量、甘油的初始含水量和反应时间等因素对辛酸转化率和产物组成的影响。结果证明,以纺织物作为载体制备的固定化假丝酵母脂肪酶适宜催化辛酸甘油酯的合成。最优反应条件为:辛酸与甘油的物质的量之比为2∶1,固定化假丝酵母脂肪酶加量为0.5g /0.69g 甘油,温度为40 ℃ ,振荡培养箱转速为190 r/min。最优反应条件下辛酸转化率可以达到94%以上,经过简单处理的固定化酶可以重复使用4批。 相似文献
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温度对产甘油假丝酵母产甘油发酵过程的影响 总被引:1,自引:0,他引:1
研究了温度对产甘油假丝酵母分批发酵生产甘油及其生长动力学的影响。结果表明:在温度为28—36℃时,由于发酵周期随温度升高而显著缩短,导致细胞生长、甘油合成和葡萄糖消耗的比速率也随温度升高逐渐增加;当温度为32℃时最适于产甘油假丝酵母合成甘油,甘油产量、得率和产率分别达到120.3 g/L,0.523 g/g,1.43 g/(L.h);应用Logistic方程对细胞生长动力学进行了模拟,获得不同温度下的生长动力学参数;根据细胞生长动力学参数,得到28—36℃时甘油分批发酵过程中细胞质量浓度同温度、时间之间的一般关系式,经验证该模型在28—36℃范围内可用于预测不同温度下的细胞生长情况。 相似文献
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产朊假丝酵母流加发酵法生产谷胱甘肽 总被引:8,自引:0,他引:8
研究了产朊假丝酵母在不同葡萄糖浓度下的谷胱甘肽(GSH)分批发酵过程,在此基础上进一步考察了重复补料、恒速流加和指数流加等不同培养方式对GSH发酵生产的影响. 结果发现,这几种培养方式都可以实现酵母细胞和GSH的高产. 综合比较,无论是从细胞还是从GSH的产量、得率和生产强度的角度来看,指数流加都是较为理想的选择. 经过48 h的指数流加培养,细胞干重达到40.9 g/L, GSH产量和胞内GSH含量分别达到857.2 mg/L和2.25%. 相似文献
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《广东化工》2021,48(12)
目的:本文以油茶果壳为原料,利用产朊假丝酵母发酵油茶果壳木糖水解液制备木糖醇,得到产朊假丝酵母发酵油茶果壳木糖水解液制备木糖醇的最佳工艺条件,为油茶果壳综合开发提供理论依据及数据参考。方法:采用稀硫酸水解油茶果壳半纤维素,利用Ca(OH)2和活性炭对水解液进行脱色脱毒,再利用产朊假丝酵母发酵水解液制备木糖醇,在单因素实验的基础上,通过响应面法设计实验优化油茶果壳木糖水解液制备木糖醇的工艺条件。结果:最佳优化结果为:初始p H值5.68,发酵温度28℃,装液量53.88 mL,接种量为10%,木糖醇得率优化值为(16.56±0.25)%。结论:方差分析结果表明,所选模型具有显著性(p0.05),相关系数R2=0.9523,验证试验木糖醇得率为(16.56±0.25)%,与预测值16.81%的误差仅为1.48%,证明所得模型可信,优化工艺参数切实可行。 相似文献
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吸附-聚合物修饰组合固定化Candida antarctica脂肪酶研究 总被引:1,自引:0,他引:1
通过吸附法联合PEG非共价修饰,研发了一种固定化南极假丝酵母脂肪酶(Candida antarctica lipase)的新方法,可以有效提高固定化酶在非水介质中的催化活性。最佳固定化条件为硅藻土:酶粉(W/W)=8,PEG4000:酶粉(W/W)=0.6,缓冲液pH7.5。采用三油酸甘油酯与甲醇的转酯化反应,测定了固定化酶的转酯活性。结果表明,固定化酶同时加入PEG进行非共价修饰,可显著提高固定化酶的转酯活力。PEG修饰的固定化酶转酯比活是未经PEG修饰的固定化酶的4.1倍,转酯酶活回收率为604.8%,说明PEG两性分子的特性对制备用于非水介质的固定化酶有重要作用。该固定化方法可显著提高Candida antarctica脂肪酶在非水介质中的催化效率,且固定化方法简单、成本低,具有工业应用价值。 相似文献
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Marianne Wittrup Larsen Dr. Dorota F. Zielinska Mats Martinelle Dr. Aurelio Hidalgo Dr. Lars Juhl Jensen Prof. Uwe T. Bornscheuer Prof. Karl Hult Prof. 《Chembiochem : a European journal of chemical biology》2010,11(6):796-801
A water tunnel in Candida antarctica lipase B that provides the active site with substrate water is hypothesized. A small, focused library created in order to prevent water from entering the active site through the tunnel was screened for increased transacylation over hydrolysis activity. A single mutant, S47L, in which the inner part of the tunnel was blocked, catalysed the transacylation of vinyl butyrate to 20 mM butanol 14 times faster than hydrolysis. The single mutant Q46A, which has a more open outer end of the tunnel, showed an increased hydrolysis rate and a decreased hydrolysis to transacylation ratio compared to the wild‐type lipase. Mutants with a blocked tunnel could be very useful in applications in which hydrolysis is unwanted, such as the acylation of highly hydrophilic compounds in the presence of water. 相似文献
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JL Montesinos E Dalmau C Casas 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2003,78(7):753-761
The yeast Candida rugosa produces multiple extracellular lipases. The production of extra‐ and intracellular lipases was investigated in continuous cultures using a sole or different mixtures of carbon sources. Also, the effect of different C:N ratios was tested. Lipase productivity in continuous cultures increased by 50% compared with data obtained from batch fermentations and depended on the dilution rate applied. Maximum yields relative to consumed substrate were obtained with oleic acid at low dilution rate. It was found that during nitrogen limitation, lipase activity was suppressed. All carbon source mixtures tested allowed both cell growth and lipase production, but extra‐ and intracellular lipase activities were affected by the combination of substrates used. Maximum extracellular lipolytic productivity was attained with lactic and oleic acid mixtures, probably due to the non‐repressor effect of these carbon sources. The chemical composition of the biomass also depended on the type of substrate used and was related to the accumulation of lipidic compounds as intracellular inclusions, which were observed when oleic acid was used as the carbon source. The results obtained were compared with previous data from batch and fed‐batch cultures in order to select the best process strategies for the lipase production with C rugosa. The best lipase yields were obtained in fed‐batch fermentations using oleic acid. Copyright © 2003 Society of Chemical Industry 相似文献