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Effects of Nicotine, a Plant Secondary Metabolite, on Protective Enzyme and Detoxification Enzyme of Frankliniella occidentalis 预览
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作者 Liu Jiani Su Yuan +3 位作者 Wei Wei Zhong Yu Chen Zebin Yu Lei 《Plant Diseases and Pests(植物病虫害研究:英文版)》 CAS 2019年第2期7-10,共4页
[Objective] The paper was to explore the effects of plant secondary metabolite on protective enzymes and detoxification enzymes of quarantine pest Frankliniella occidentalis.[Method] F.occidentalis were continuously e... [Objective] The paper was to explore the effects of plant secondary metabolite on protective enzymes and detoxification enzymes of quarantine pest Frankliniella occidentalis.[Method] F.occidentalis were continuously exposed to artificial diets containing nicotine from the second to fifth instars for five generations, and the effects of nicotine on protective enzymes and detoxification enzymes of larvae were determined.[Result] The activities of carboxylate esterase (CarE) and glutathione-S-transferase (GST) in midgut of the fifth instar larvae were significantly increased, and reached the maximum at the third generation (1.86 times and 1.59 times, respectively). Nicotine inhibited the activities of superoxide dismutase (SOD) and catalase (CAT). With the increase of feeding generations, the inhibitory effect of nicotine weakened. Nicotine significantly increased the activities of peroxidase (POD).[Conclusion] F. occidentalis will gradually adapt to the harm of plant toxins by starting its own detoxification enzyme system and regulating protective enzyme system after feeding on plant secondary substance nicotine. 展开更多
关键词 NICOTINE FRANKLINIELLA OCCIDENTALIS DETOXIFICATION ENZYME Protective ENZYME
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影响多步脱氢酶CrtI功能的关键结构特征探索 预览
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作者 陈琛 王颖 +3 位作者 刘宏 陈艳 姚明东 肖文海 《化工学报》 EI CAS CSCD 北大核心 2019年第1期189-198,共10页
在生物体内存在可催化多步连续反应的通用酶,对生物代谢过程具有重要作用。八氢番茄红素脱氢酶(CrtI)作为典型代表,可以催化多步连续脱氢反应,生成番茄红素等具有重要价值的产物。本文以酿酒酵母为底盘研究CrtI的催化功能特征。首先通... 在生物体内存在可催化多步连续反应的通用酶,对生物代谢过程具有重要作用。八氢番茄红素脱氢酶(CrtI)作为典型代表,可以催化多步连续脱氢反应,生成番茄红素等具有重要价值的产物。本文以酿酒酵母为底盘研究CrtI的催化功能特征。首先通过组合设计与筛选番茄红素合成路径中的三种外源酶CrtE、CrtB和CrtI,发现CrtI是主要的限制因素,且三孢布拉氏霉菌来源的CrtI(BtCrtI)表现出优异的催化功能。通过生物信息学与蛋白结构分析发现BtCrtI的S311残基是连接和稳定活性中心结构的关键。随后通过分析该位点的饱和突变结果,揭示了该位点的氨基酸残基类型对活性中心结构和功能的显著作用,为酶的设计和改造提供了新的思路。同时发现CrtI的活性差异未对合成路径中的类胡萝卜素的代谢流造成扰动,表明CrtI是番茄红素的产量和纯度的决定因素. 展开更多
关键词 合成生物学 生物催化 八氢番茄红素脱氢酶 多步脱氢反应 酶的活性中心结构
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低温等离子体预处理酶对苎麻织物的脱胶研究 预览
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作者 汤云高 祁丽 龙家杰 《纺织科学与工程学报》 CAS 2019年第3期52-58,共7页
将低温等离子体预处理后的脱胶酶用于苎麻织物的脱胶前处理,对其主要影响因素进行了探讨,并通过正交试验和配方试验进行了优化。结果表明,低温等离子预处理酶种类对苎麻织物的脱胶失重率、毛效、白度有非常显著的影响,而脱胶处理时间对... 将低温等离子体预处理后的脱胶酶用于苎麻织物的脱胶前处理,对其主要影响因素进行了探讨,并通过正交试验和配方试验进行了优化。结果表明,低温等离子预处理酶种类对苎麻织物的脱胶失重率、毛效、白度有非常显著的影响,而脱胶处理时间对织物失重率有显著的影响,脱胶温度则对织物白度有显著影响;但溶液pH值及其他工艺因素,以及因素间的交互作用对脱胶效果影响不显著;经正交试验优选后的推荐脱胶工艺为:脱胶温度为55.0℃,溶液pH为4.0,处理时间为100.0min;配方试验显示,经低温等离子体预处理后的混合生物酶,以脱胶失重率为指标的最佳比例为木聚糖酶:果胶酶=0.57:0.43,混合酶总用量为8.0%(o.m.f)。实验同时表明,低温等离子体预处理脱胶酶对苎麻织物的脱胶效率得到显著改善。 展开更多
关键词 苎麻织物 生物酶 脱胶 低温等离子体 预处理酶
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Ionic Liquid-Polypyrrole-Gold Composites as Enhanced Enzyme Immobilization Platforms forHydrogen Peroxide Sensing 预览
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作者 Meng Li Jing Wu +3 位作者 Haiping Su Yazhuo Shang Yifan He Honglai Liu 《北京日化》 2019年第2期15-32,共18页
In this work, three different aqueous solutions containing imidazole-based ILs w让h different alkyl chain lengths ([Cnmim]Br, n = 2Z 6,12) were adopted as the medium for the synthesis of ionic liquid-polypyrrole (IL-P... In this work, three different aqueous solutions containing imidazole-based ILs w让h different alkyl chain lengths ([Cnmim]Br, n = 2Z 6,12) were adopted as the medium for the synthesis of ionic liquid-polypyrrole (IL-PPy) composites. Herein, the ILs undertook the roles of the pyrrole solvent, the media for emulsion polymerization of PPy and PPy dopants, respectively. The electrochemical performances of the three IL-PPy composites on a glassy carbon electrode (GCE) were investigated by electrochemical experiments, which indicated that [Ci2mim]Br-PPy (Ci2~PPy) composites displayed better electrochemical performance due to their larger surface area and firmer immobilization on the GCE. Further, Ci2?PPy/GCE were decorated with Au microparticles by electrodeposition that can not only increase the conductivity, but also immobilize sufficient biomolecules on the electrode. Then, the obtained Ci2~PPy~Au/GCE with outstanding electrochemical performance was employed as a horseradish peroxidase (HRP) immobilization platform to fabricate a novel Ci2-PPy-Au-HRP/GCE biosensor for H2O2 detection. The results showed that the prepared Ci2-PPy-Au-HRP/GCE biosensor exhibited high sensitivity, fast response, and a wide detection range as well as low detection limit towards H2O2. This work not only provides an outstanding biomolecule immobilization matrix for the fabrication of highly sensitive biosensors, but also advances the understanding of the roles of ILs in improving the electrochemical performance of biosensors. 展开更多
关键词 ionic liquids (ILs) POLYPYRROLE (PPy) GOLD particles HORSERADISH PEROXIDASE (HRP) enzyme immobilization hydrogen PEROXIDE sensor
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日立7080酶法检测钠交叉污染的查找和清除 预览
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作者 李伟波 李娟 贾黎方 《检验医学与临床》 CAS 2019年第1期54-56,60共4页
目的探讨日立7080酶法检测钠的交叉污染的清除问题。方法首先通过试验检查样品针是否携带污染,然后通过试验发现试剂间有无交叉污染,进而查找试剂间交叉污染发生的位置,最终采取相应的措施消除交叉污染。结果试剂针被污染时,总胆红素(TB... 目的探讨日立7080酶法检测钠的交叉污染的清除问题。方法首先通过试验检查样品针是否携带污染,然后通过试验发现试剂间有无交叉污染,进而查找试剂间交叉污染发生的位置,最终采取相应的措施消除交叉污染。结果试剂针被污染时,总胆红素(TBIL)和低密度脂蛋白胆固醇(LDL-C)2个项目对酶法检测钠有显著影响。结论生化分析仪试剂针老化导致酶法检测钠发生交叉污染后,只能更换试剂针R1和R2,污染才能彻底消除。 展开更多
关键词 酶法 交叉污染
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糯米发酵酱姜风味酵素饮品配方及工艺优化研究 预览
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作者 朱建华 邹秀容 +4 位作者 刘日斌 黄静梅 林如 古丽容 刘波 《江西农业学报》 CAS 2019年第7期92-97,共6页
采用糯米发酵酱姜提取液为基料,然后以感官评分、可溶性固形物含量及粒度参数为综合指标,在单因素实验的基础上进行正交试验,优化得出糯米发酵酱姜基料风味饮品的最佳配方参数:柠檬酸0.10%(w/w),白砂糖7.0%(w/w),酱姜浸提液基料30%(w/w)... 采用糯米发酵酱姜提取液为基料,然后以感官评分、可溶性固形物含量及粒度参数为综合指标,在单因素实验的基础上进行正交试验,优化得出糯米发酵酱姜基料风味饮品的最佳配方参数:柠檬酸0.10%(w/w),白砂糖7.0%(w/w),酱姜浸提液基料30%(w/w),卡拉胶0.02%(w/w)。在该最优条件下制备的酱姜风味酵素饮品具有最佳的品质和最好的储存稳定性。 展开更多
关键词 糯米 酱姜 酵素 风味饮品 配方优化 粒度
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Recovery of Chitin and Protein from Shrimp Head Waste by Endogenous Enzyme Autolysis and Fermentation 预览
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作者 GUO Na SUN Jianan +1 位作者 ZHANG Zhaohui MAO Xiangzhao 《中国海洋大学学报:英文版》 SCIE CAS CSCD 2019年第3期719-726,共8页
The industrial processing of shrimp produces massive quantities of solid waste that is a notable source of animal protein, chitin, carotenoids, and other bioactive compounds that are not appropriately utilized. In the... The industrial processing of shrimp produces massive quantities of solid waste that is a notable source of animal protein, chitin, carotenoids, and other bioactive compounds that are not appropriately utilized. In the present study, chitin and protein extraction from shrimp head with autolysis and fermentation using Bacillus licheniformis were investigated. The results showed that when shrimp heads were autolyzed with a natural pH at 50℃ for 4 h, the total amino acid nitrogen in the supernatant was 5.01 mg mL^-1. Then, when a 50%(v/m) inoculum of the hydrolysate was incubated at 60℃ for 10 h, a deproteinization rate of 88.3% could be obtained. The fermented supernatant was processed into a dry protein powder, while the residues were demineralized by 10% citric acid for chitin. The recovered protein powder contained 5.5% moisture, 11.5% ash, and 66.7% protein, while the chitin contained 3.5% moisture, 2.1% ash, and 3.1% protein. In addition, amino acids, minerals, heavy metals, the degree of acetylation, microstructure, and Fourier-transform infrared(FT-IR) spectroscopy results were analyzed. Furthermore, the statistics of the large scale trial after treatment with 20 kg of shrimp heads were analyzed. Thus, this work made the shrimp waste utilization environmentally sound and valuable. 展开更多
关键词 shrimp head WASTE ENDOGENOUS ENZYME AUTOLYSIS FERMENTATION CHITIN
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淀粉表面施胶剂制备系统常见故障与处理 预览
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作者 吕晓峰 钱雪峰 张小红 《中华纸业》 CAS 2019年第10期61-63,共3页
淀粉是一种重要的造纸表面施胶剂原料。由于原淀粉黏度高,流动性差,易产生凝沉现象,因此需要对淀粉进行改性,使其在较高浓度时仍具有较低的黏度,满足纸页表面施胶处理的要求。在实际生产中,商品淀粉是不溶性的白色粉末,厂家应根据需要... 淀粉是一种重要的造纸表面施胶剂原料。由于原淀粉黏度高,流动性差,易产生凝沉现象,因此需要对淀粉进行改性,使其在较高浓度时仍具有较低的黏度,满足纸页表面施胶处理的要求。在实际生产中,商品淀粉是不溶性的白色粉末,厂家应根据需要完成淀粉悬浮液的“糊化”过程,制备淀粉胶[1]。目前,大型纸机都会配置淀粉连续制备设备,用于制备淀粉胶。连续蒸煮设备自动运行,不需要人为操作,具有质量稳定、产量高等优点[2]。比较常见的制备工艺如图1。 展开更多
关键词 淀粉 淀粉酶 故障 处理
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Benefits of Biochars and NPK Fertilizers for Soil Quality and Growth of Cowpea (Vigna unguiculata L. Walp.) in an Acid Arenosol
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作者 Rogerio Borguete Alves RAFAEL Maria Luisa FERNANDEZ-MARCOS +3 位作者 Stefania COCCO Maria Letizia RUELLO Flavio FORNASIER Giuseppe CORTI 《土壤圈:英文版》 SCIE CAS CSCD 2019年第3期311-333,共23页
Fertilization is required for optimum plant growth, particularly in unfertile soils, while optimizing nutrient use effciency is an alternative to reduce inorganic fertilizer needs and reduce environmental problems cau... Fertilization is required for optimum plant growth, particularly in unfertile soils, while optimizing nutrient use effciency is an alternative to reduce inorganic fertilizer needs and reduce environmental problems caused by nutrient leaching. This study investigated soil properties and cowpea yield responses to biochars(BCs) made from different feedstocks, baby corn peel biochar(BC1), branches of mango tree biochar(BC2), and rice husk biochar(BC3), applied in combination with nitrogen-phosphorus-potassium(NPK) fertilizers.The experiment was conducted in a greenhouse, using an acid sandy soil(Arenosol) that was submitted for 70 d to the following eight treatments: i) control;ii) full dose of NPK(a commercial compound fertilizer(12-24-12 of N-P2O5-K2O)+ urea(46% N));iii) BC1+ half dose of NPK;iv) BC1 + full dose of NPK;v) BC2 + half dose of NPK;vi) BC2 + full dose of NPK;vii) BC3 + half dose of NPK;and viii) BC3 + full dose of NPK. All biochars were applied at a rate of 0.9%(weight/weight), and each type of biochar was combined with half and full doses of NPK fertilizers. Soil pH increased significantly(P < 0.05) in treatments with BC1 and BC2,while cation exchange capacity(CEC) and available P were higher in the treatments with BC1;BC1 and BC2 also induced higher activity of enzymes related to the P cycle and higher cowpea yield. Similar soil properties and cowpea yield parameters were obtained with the full and half doses of NPK fertilizers for each type of biochar used. In conclusion, biochars in the combination with NPK fertilizers improved soil chemistry and enzymatic activities, allowing reduced fertilizer application and food production costs in the acid soil studied. 展开更多
关键词 ACID SOIL NUTRIENT use effciency organic amendment plant GROWTH potential enzyme activity SOIL FERTILITY SOIL pH
脑脊液酶谱在阿尔茨海默病中的研究进展 预览
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作者 张齐皓 刘辰庚 王培昌 《中国医药导报》 CAS 2019年第14期19-22,共4页
阿尔茨海默病(AD)是一种与年龄相关的、渐进性的神经系统变性疾病,是导致老年期痴呆最常见的病因。AD进展缓慢,病情呈进行性加重,在AD的发生发展中,不同的阶段伴随着相应的病理生理改变,在AD痴呆阶段之前还存在一个从几年到几十年的痴... 阿尔茨海默病(AD)是一种与年龄相关的、渐进性的神经系统变性疾病,是导致老年期痴呆最常见的病因。AD进展缓慢,病情呈进行性加重,在AD的发生发展中,不同的阶段伴随着相应的病理生理改变,在AD痴呆阶段之前还存在一个从几年到几十年的痴呆前阶段,而AD患者脑脊液中的酶可作为反映疾病变化过程的生物标志物,对于AD的早期诊治具有重要的意义。本文将对脑脊液中的一些酶在AD中的研究现状进行综述。 展开更多
关键词 阿尔茨海默病 脑脊液 BACE1 KLK6 基质金属蛋白酶
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柠檬苦素降解菌C6降解特性及活性降解酶的分离纯化 预览
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作者 张锦华 臧三丽 +2 位作者 白宝清 岳建伟 范三红 《山西农业科学》 2019年第2期143-151,共9页
对从新鲜醋醅中分离到的一株柠檬苦素降解菌C6(Raoultella ornithinolytica)在酸性条件下的柠檬苦素降解特性进行了研究,并对相关酶系进行了分离纯化。分别从菌龄、接种量、培养时间、柠檬苦素浓度4个因素考察了该菌株对柠檬苦素的降解... 对从新鲜醋醅中分离到的一株柠檬苦素降解菌C6(Raoultella ornithinolytica)在酸性条件下的柠檬苦素降解特性进行了研究,并对相关酶系进行了分离纯化。分别从菌龄、接种量、培养时间、柠檬苦素浓度4个因素考察了该菌株对柠檬苦素的降解情况,结合响应面优化了该菌株的降解条件,并在最适条件下对其降解速率进行评价。进一步通过硫酸铵沉淀、Sephadex G-100凝胶过滤层析及DEAE-纤维素柱层析对菌株C6发酵上清液中的柠檬苦素降解酶逐步纯化。结果表明,菌龄10 h、底物柠檬苦素质量浓度为4 mg/L、接种量1%的条件下,作用时间为12 h时菌株C6对柠檬苦素的降解速率可达到91.28%±0.17%,其中作用时间9 h以后降解速率显著增加,经纯化后获得相对分子量约为27 ku的电泳纯柠檬苦素降解酶,纯化倍数为9.44。结果可为该菌株及其酶的进一步开发利用提供理论依据。 展开更多
关键词 柠檬苦素降解菌 降解特性 响应面优化 分离纯化
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亚麻浸泡脱胶与短时间浸渍脱胶的比较 预览
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作者 田英华 张羽飞 +1 位作者 刘晓兰 王路 《毛纺科技》 CAS 北大核心 2019年第4期34-37,共4页
为进一步研究浸泡法与短时浸渍法亚麻脱胶体系,优化酶法亚麻脱胶工艺,分别研究了酶用量及pH值对浸泡法和浸渍法2种脱胶体系中还原糖、总糖含量及脱胶后亚麻纤维分裂度的影响。结果表明:2个脱胶体系的适宜酶用量均为5 g/L,浸泡法脱胶适... 为进一步研究浸泡法与短时浸渍法亚麻脱胶体系,优化酶法亚麻脱胶工艺,分别研究了酶用量及pH值对浸泡法和浸渍法2种脱胶体系中还原糖、总糖含量及脱胶后亚麻纤维分裂度的影响。结果表明:2个脱胶体系的适宜酶用量均为5 g/L,浸泡法脱胶适宜pH值为3.7~4.0,短时浸渍法脱胶适宜pH值为4.8。浸泡法亚麻脱胶体系中还原糖和总糖含量均高于短时浸渍法脱胶,浸泡法脱胶的纤维一致性较好,而短时浸渍法脱胶在纤维分离度及酶液用量方面更具优势。 展开更多
关键词 亚麻 脱胶 浸泡法 短时浸渍法
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ARTP诱变技术在食品和饲料加工生物催化剂改造中的应用进展 预览
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作者 张雪 吴亦楠 +4 位作者 马飞 王立言 张翀 李和平 邢新会 《生物产业技术》 2019年第3期13-24,共12页
食品和饲料的生物催化转化和发酵技术成为保障餐桌安全及绿色发展的重要领域,其用酶量在工业酶制剂市场中占比最大,且增长最快。性能优良的酶制剂能显著缩短发酵周期,降低生产成本,提高目标产物的转化率,进而提高市场竞争力。食品和饲... 食品和饲料的生物催化转化和发酵技术成为保障餐桌安全及绿色发展的重要领域,其用酶量在工业酶制剂市场中占比最大,且增长最快。性能优良的酶制剂能显著缩短发酵周期,降低生产成本,提高目标产物的转化率,进而提高市场竞争力。食品和饲料加工产业除了应用分离提取的酶制剂外,很多发酵过程仍以微生物为细胞工厂进行多种酶催化转化。该发酵过程通常涉及复杂的代谢网络和调控机制,且很多体系不能采用基因工程技术,因此理性基因工程改造通常难以满足应用需求。诱变育种仍然是食品和饲料加工用酶及微生物菌株改造的主要手段,需要与时俱进不断发展新技术。近年发展起来的常压室温等离子体(ARTP)诱变育种技术因其具有操作简单、安全、环境友好、突变率高、突变库容大等特点,在食品和饲料加工微生物育种中得到了广泛应用,取得了良好的成效。重点介绍近年ARTP在食品与饲料加工酶制剂及发酵微生物改造中的相关应用进展。 展开更多
关键词 常压室温等离子体(ARTP) 酶制剂 食品和饲料加工 微生物发酵 诱变育种
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酶及其生物催化技术的研究与应用 预览
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作者 杨林 陈志 +1 位作者 姜水琴 魏东芝 《生物产业技术》 2019年第3期25-35,共11页
与传统化学催化工艺相比,基于酶的生物催化工艺具有反应条件温和、环境友好、操作简便、立体选择性优良等优势。当前已有多个生物催化工艺应用于生产精细大宗化学品和高附加值医药中间体,此外在食品、化妆品等领域也有广泛的应用。主要... 与传统化学催化工艺相比,基于酶的生物催化工艺具有反应条件温和、环境友好、操作简便、立体选择性优良等优势。当前已有多个生物催化工艺应用于生产精细大宗化学品和高附加值医药中间体,此外在食品、化妆品等领域也有广泛的应用。主要综述了酶及其生物催化技术的研究进展,包括酶序的构建、酶的定向进化,以及酶与生物催化技术在大宗化学品、医药中间体、食品、化妆品、纺织以及纸浆造纸工业中的应用。 展开更多
关键词 生物催化 选择性 精细大宗化学品 高附加值医药中间体
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Construction of an efficient genomic editing system with CRISPR/Cas9 in the vector mosquito Aedes albopictus
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作者 Tong Liu Wen-Qiang Yang +8 位作者 Yu-Gu Xie Pei-Wen Liu Li-Hua Xie Feng Lin Chen-Ying Li Jin-Bao Gu Kun Wu Gui-Yun Yan Xiao-Guang Chen 《昆虫科学:英文版》 SCIE CAS CSCD 2019年第6期1045-1054,共10页
Aedes (Stegomyia) albopictus, also known as the Asian tiger mosquito, is a mosquito which originated in Asia. In recent years, it has become increasingly rampant throughout the world. This mosquito can transmit severa... Aedes (Stegomyia) albopictus, also known as the Asian tiger mosquito, is a mosquito which originated in Asia. In recent years, it has become increasingly rampant throughout the world. This mosquito can transmit several arboviruses, including dengue, Zika and chikungunya viruses, and is considered a public health threat. Despite the urgent need of genome engineering to analyze specific gene functions, progress in genetical manipulation of Ae. albopictus has been slow due to a lack of efficient methods and genetic markers. In the present study, we established targeted disruptions in two genes, kynurenine hydroxylase (kh) and dopachrome conversion enzyme (yellow), to analyze the feasibility of generating visible phenotypes with genome editing by the clustered regularly interspaced short palindromic repeats (CRISPR)/ CRISPR-associated protein 9 (Cas9) system in Ae. albopictus. Following Cas9 single guide RNA ribonucleoprotein injection into the posterior end of pre-blastoderm embryos, 30%-50% of fertile survivors produced alleles that failed to complement existing kh and yellow mutations. Complete eye and body pigmentation defects were readily observed in GI pupae and adults, indicating successful generation of highly heritable mutations. We conclude that the CRISPR/Cas9-mediated gene editing system can be used mAe. albopictus and that it can be adopted as an efficient tool for genome-scale analysis and biological study. 展开更多
关键词 AEDES ALBOPICTUS CRISPR/Cas9 dopachrome conversion enzyme (yellow) gene EDITING KYNURENINE HYDROXYLASE (kh)
Engineering the Biosynthesis of Caffeic Acid in Saccharomyces cerevisiae with Heterologous Enzyme Combinations 预览
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作者 Lanqing Liu Hong Liu +4 位作者 Wei Zhang Mingdong Yao Bingzhi Li Duo Liu Yingjin Yuan 《工程(英文)》 2019年第2期287-295,共9页
Engineering the biosynthesis of plant-derived natural products in microbes presents several challenges, especially when the expression and activation of the plant cytochrome P450 enzyme is required. By recruiting two ... Engineering the biosynthesis of plant-derived natural products in microbes presents several challenges, especially when the expression and activation of the plant cytochrome P450 enzyme is required. By recruiting two enzymes—HpaB and HpaC—from several bacteria, we constructed functional 4- hydroxyphenylacetate 3-hydroxylase (4HPA3H) in Saccharomyces cerevisiae to take on a role similar to that of the plant-derived cytochrome P450 enzyme and produce caffeic acid. Along with a common tyrosine ammonia lyase (TAL), the different combinations of HpaB and HpaC presented varied capabilities in producing the target product, caffeic acid, from the substrate, L-tyrosine. The highest production of caffeic acid was obtained with the enzyme combination of HpaB from Pseudomonas aeruginosa and HpaC from Salmonella enterica, which yielded up to (289.4 ± 4.6) mg-L1 in shake-flask cultivation. The compatibility of heterologous enzymes within a yeast chassis was effectively improved, as the caffeic acid production was increased by 40 times from the initial yield. Six key amino acid residues around the flavin adenine dinucleotide (FAD) binding domain in HpaB from Pseudomonas aeruginosa were differentiate from those other HpaBs, and might play critical roles in affecting enzyme activity. We have thus established an effective approach to construct a highly efficient yeast system to synthesize non-native hydroxylated phenylpropanoids. 展开更多
关键词 SACCHAROMYCES CEREVISIAE Caffeic acid HETEROLOGOUS enzyme CYTOCHROME P450 Synthetic biology
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数据与计算驱动的蛋白质元件预测和设计
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作者 刘海燕 陈泉 +3 位作者 龙朋朋 黄斌 许洋 陈耀晞 《生命科学》 CSCD 北大核心 2019年第4期357-363,共7页
为实现特定合成生物系统,需要使用恰当的蛋白质元件,即具有所需的特异性分子识别、酶催化活性等功能的天然蛋白质或工程改造蛋白质。以转录因子所识别的DNA序列的预测以及蛋白质-小分子特异性结合口袋的预测和设计为例,介绍计算方法在... 为实现特定合成生物系统,需要使用恰当的蛋白质元件,即具有所需的特异性分子识别、酶催化活性等功能的天然蛋白质或工程改造蛋白质。以转录因子所识别的DNA序列的预测以及蛋白质-小分子特异性结合口袋的预测和设计为例,介绍计算方法在蛋白质功能预测和设计中的作用。强调了不同类型计算工具的整合以及它们与生物背景知识整合、计算方法通用性和准确性之间的平衡;讨论了有待解决的问题、计算的潜力和新方法的发展需求。 展开更多
关键词 计算方法 转录因子 DNA结合预测 结合口袋设计
应用胶黏物控制酶的工厂试验 预览
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作者 马小清 王海荣 +5 位作者 郭启程 张安钵 聂义彬 王友成 韩国栋 许永刚 《中华纸业》 CAS 2019年第8期46-48,共3页
华泰集团12#机采用100%废新闻纸生产新闻纸过程中,胶黏物给生产和产品质量带来严重问题。用生物酶控制胶黏物在12#机进行了工厂中试。中试结果表明:经过酶处理后,成浆池纸浆中胶黏物含量和数量减少,纸机前烘刮刀上的胶黏物明显减少,黏... 华泰集团12#机采用100%废新闻纸生产新闻纸过程中,胶黏物给生产和产品质量带来严重问题。用生物酶控制胶黏物在12#机进行了工厂中试。中试结果表明:经过酶处理后,成浆池纸浆中胶黏物含量和数量减少,纸机前烘刮刀上的胶黏物明显减少,黏性降低,并且纸机车速提高。 展开更多
关键词 废新闻纸 生物酶 胶黏物 纸机
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合成烷基糖苷催化剂研究进展 预览
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作者 钱锋 华平 +3 位作者 喻红梅 胡圣洁 郭雨晨 冯娇娇 《精细石油化工进展》 CAS 2019年第1期30-32,38共4页
介绍了合成烷基糖苷过程有关催化剂的研究进展,包括生物酶催化剂、无机酸催化剂、有机酸催化剂和固体酸催化剂。为开发高效催化剂,生产质量高、性能稳定的APG提供理论参考。
关键词 烷基糖苷 合成 催化剂 生物酶
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含硫酸根的高碳氮比废水产甲烷强化技术及酶学机制
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作者 苏建聪 何青山 +2 位作者 李秀芬 王新华 任月萍 《环境化学》 CAS CSCD 北大核心 2019年第1期217-223,共7页
污泥蛋白质回收已成为剩余污泥资源化的有效途径之一,研究其提取残液的产甲烷强化技术不仅可助力剩余污泥蛋白质提取技术的应用进程,也可为化工、食品行业高硫酸根和高碳氮比废水的厌氧生物处理提供有益参考.结果表明,铁及其螯合物添加... 污泥蛋白质回收已成为剩余污泥资源化的有效途径之一,研究其提取残液的产甲烷强化技术不仅可助力剩余污泥蛋白质提取技术的应用进程,也可为化工、食品行业高硫酸根和高碳氮比废水的厌氧生物处理提供有益参考.结果表明,铁及其螯合物添加不仅可有效促进水解酸化与产甲烷过程关键酶的活性,还可显著抑制亚硫酸盐还原酶的活性,产气效果得到明显提高.当添加10μmol·L-1氨三乙酸与40 mg·L-1零价铁时,累积产气率达196.2 m L·g-1COD,与对照实验相比,提高了123.97%.多糖是含硫酸根的高碳氮比废水产甲烷的主要底物.结合关键酶活性的变化发现,与酸化过程相比,多糖与蛋白质水解是提高产甲烷效果的限速步骤. 展开更多
关键词 碳氮比 SO42- 甲烷 污泥
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