酶法转化五倍子单宁酸生产没食子酸

概述了黑曲霉单宁酶酶法转化五倍子单宁酸生产没食子酸的原理和方法、酶源菌种的分离和选育、工艺技术的特点、产品质量规格及在国内食品、医药行业相关部门的应用等。该酶法生产工艺具有原辅料来源易得、菌种单宁酶活力高、生产性能较稳定、生产成本低廉、工艺操作方便、产品质量优等特点。     

L-苯丙氨酸的产业化开发

L-苯丙氨酸一直是临床医药氨基酸输液和食品添加剂的重要组成部分,近年来,随着阿斯巴甜成为国际最流行的甜味剂产品,市场对L-苯丙氨酸的需求激增。国际上L-苯丙氨酸的生产厂家主要集中在美国、日本和韩国,我国目前的年生产能力不足600t/a,无法满足需求。国内的L-苯丙氨酸生产方法有发酵法与酶法,本文介绍的海因酶法生产工艺已经达到国际先进水平。     

科技动态

合成苯丙酮酸 江苏省江都化肥厂研制成功氯苄催化羰基合成法生产苯丙酮酸的新工艺,并形成300吨的年产能力。经中国药科大学生物技术中心检测和试用,转氨酶活力、水溶性、纯度等指标超过从美国西格玛公司进口的同类产品,完全符合固定化酶转化生产L-苯丙氨酸的要求。 新工艺具有产品质量好、收率高、成本低等优点,达到国际先进水平。新工艺的研制成功表明我国即将结束进口L-苯丙氨酸的历史。目前我国L-苯丙氨酸主     

我国酶法生产L-苯丙氨酸的十年研发历程及产业化前景

L-苯丙氨酸(L-Phe)是医药输液制品和食品添加剂APM(健康糖)的必需成分,全球每年需求量为3万t,主要由美国孟山都公司、日本味之素公司、韩国大象公司、德国迪高萨公司等几家大公司生产,我国1998年以前所需要的L-Phe全部依靠进口.中国科学院成都生物研究所于1991年成功开发了红酵母苯丙氨酸解氨酶(PAL)/肉桂酸技术途径生产L-Phe,并于1998年与企业合作建成了一套100t/a生产装置,使得我国成为继美、日、德、韩之后又一个能够工业化生产这一重要氨基酸产品并自主开发这一高新技术的国家.目前,我国L-Phe的实际产量只有500～600t/a,进口量达700t/a,因此,未来L-Phe发展前景看好.     

酶法转化体系中L-苯丙氨酸的络合萃取

L-苯丙氨酸的分离提取对于促进酶法制备工艺的产业化进程具有重要价值。利用络合萃取分配系数、分离选择性高的特点,对苯丙酮酸酶法制备L-苯丙氨酸转化体系中L-苯丙氨酸的络合萃取进行了研究。以二(2-乙基己基)磷酸为萃取剂,研究了水相平衡pH、萃取剂浓度和稀释剂的种类对分配系数的影响;并利用D2EHPA-正辛醇体系对酶法制备L-苯丙氨酸的转化液进行了络合萃取研究,经4次萃取和1次反萃,L-苯丙氨酸的萃取率达到98 15%;经1次反萃,L-苯丙氨酸的收率达94 33%。     

膜分离技术在酶法生产L-苯丙氨酸中的应用

酶法生产L-苯丙氨酸的工艺中，反应液中含有大量的菌体及其碎片、酶和生物大分子等杂质。要去除这些杂质，得到高质量的清液很困难，以往采用分离机来分离反应液，清液质量很不理想。改用超滤分离技术后，解决了这一难题。超滤能有效截留反应液中的杂质，清液透光率达90％以上，而且费用低、效率高，保证了后续工序的顺利进行，极大地提高了产品质量，取得了明显的经济效益。     

对我国L-苯丙氨酸产业化发展的一些看法

编者按:杨顺楷研究员,一直在中国科学院成都生物研究所应用与环境微生物中心生物转化实验室从事甾体和非甾体化合物微生物转化及酶法加工的研究开发工作,已有多项生物转化技术成果应用于我国药物及食品工业生产郜门,1996年起享受国务院政府特殊津贴,现任中国化工学会生物化工专业委员会和中国微生物学会酶工程专业委员会委员.杨顺楷老师于1991年成功开发了"红酵母苯丙氨酸解氨酶/肉桂酸技术途径生产L-苯丙氨酸"工艺,并于1998年成功实现产业化连续生产. 国家自"七五"攻关开始对"L-苯丙氨酸的产业化"进行立项,时至今日已经过去23年,其发展道路不可谓不曲折.针对目前网络上关于L-苯并氨酸的虚假新闻,杨顺楷老师在自己的博客(http://www.sciencenet.cn/blog/user_content.aspx?id=35353)中以亲历者的身份,科学、严谨地提出"我国L-苯丙氨酸产业化之路为何如此艰难曲折?" 本文为杨顺楷老师专门为本刊撰写的关于"L-笨丙氨酸"产业化的一些看法,抛砖引玉,欢迎有兴趣的业内人士本着学术民主、思想开放、公平竞争、造福国民的理念积极参与评述"我国L-苯丙氨酸的产业化之路".     

重组大肠杆菌苯丙氨酸解氨酶稳定性和反式肉桂酸的转化

为了提高反式肉桂酸合成L-苯丙氨酸的产率,研究了效应物、还原剂和金属离子对重组大肠杆菌苯丙氨酸解氨酶(PAL)稳定性的影响,并利用响应面法优化了反式肉桂酸的转化条件.结果表明,体积浓度为10%的甘油水溶液可以显著提高酶稳定性,巯基乙醇、蔗糖、Mg2 能提高比酶活,但Cu2 和 Co2 使PAL失活.响应面分析结果表明,当pH为9.85,肉桂酸浓度为6.058 g/L, 底物与酶量的体积比率为3.3时, 反式肉桂酸转化率为80.5 %,比不优化条件下的转化率提高了15.7%.     

DL-氨基己内酰胺的合成

近年来,日本东丽公司应用化学合成与酶法相结合的新工艺,以环己烯为原料,经加成、氨化、贝克曼重排三步化学反应制成DL-氨基己内酰胺,再用双酶转化DL-氨基己内酰胺得到L-赖氨酸。应用DL-氨基己内酰胺中间体制备L-赖氨酸的主要特点是,既解决了用化工原料代替农副产品生产L-赖氨酸,又找到     

离子交换法分离高盐体系中的L-苯丙氨酸

引　言Ｌ -苯丙氨酸 (Ｌ -Ｐｈｅ)是自 2 0世纪 80年代以来市场需求增长较快的氨基酸品种之一 ,以它为原料生产的甜味剂阿斯巴甜已在世界近百个国家批准使用 ,Ｌ -苯丙氨酸的工业化具有可观的经济效益和社会效益 .Ｌ -苯丙氨酸生产主要有发酵法、化学拆分和前体酶法合成法 .目前研究较多且工业化最为成功的是前体酶法合成Ｌ -苯丙氨酸的生产工艺 .以海因为前体的酶法制备Ｌ -苯丙氨酸路线具有酶活高、耐受性好和生产条件粗放等优点 ,因此该工艺被工业研究部门认为是最经济、最直接的Ｌ -苯丙氨酸生产方法[1] .Ｌ -苯丙氨酸的分离主要有锌盐…     

Early Phenylpropanoid Biosynthetic Steps in Cannabis sativa: Link between Genes and Metabolites

Phenylalanine ammonia-lyase (PAL), Cinnamic acid 4-hydroxylase (C4H) and 4-Coumarate: CoA ligase (4CL) catalyze the first three steps of the general phenylpropanoid pathway whereas chalcone synthase (CHS) catalyzes the first specific step towards flavonoids production. This class of specialized metabolites has a wide range of biological functions in plant development and defence and a broad spectrum of therapeutic activities for human health. In this study, we report the isolation of hemp PAL and 4CL cDNA and genomic clones. Through in silico analysis of their deduced amino acid sequences, more than an 80% identity with homologues genes of other plants was shown and phylogenetic relationships were highlighted. Quantitative expression analysis of the four above mentioned genes, PAL and 4CL enzymatic activities, lignin content and NMR metabolite fingerprinting in different Cannabis sativa tissues were evaluated. Furthermore, the use of different substrates to assay PAL and 4CL enzymatic activities indicated that different isoforms were active in different tissues. The diversity in secondary metabolites content observed in leaves (mainly flavonoids) and roots (mainly lignin) was discussed in relation to gene expression and enzymatic activities data.     

第三单体SIPM合成工艺的探讨

介绍了以间苯二甲酸(IPA)合成阳离子第三单体SIPM的工艺方法。重点介绍了提高反应速率,抑制副反应和提高产品品质的方法与途径。该合成工艺产品总收率71.9％,为文献指导使用20％发烟硫酸磺化工艺国内先进水平。     

Quick identification of a simple enzyme deactivation model for an extended-Michaelis-Menten reaction type. Exemplification for the D-glucose oxidation with a complex enzyme deactivation kinetics

One essential engineering problem when developing an industrial enzymatic process concerns the model-based design and optimal operation of the enzymatic reactor based on the process and enzyme inactivation kinetics. For a complex enzymatic system, the “default” used first-order enzyme deactivation model has been proved to lead to inadequate process design or sub-optimal operating policies. The present study investigates if a complex enzyme deactivation can be approximated with simple 1st, 2nd, or a novel proposed model with variable deactivation constant. The approached complex enzymatic system is those of the oxidation of D-glucose to 2-keto-D-glucose in the presence of pyranose 2-oxidase. The necessary “simulated experimental data” have been generated by means of an extended kinetic model from literature used to simulate a batch reactor under well-defined nominal conditions. The proposed enzyme deactivation model has been found to be the best lumping alternative, presenting several advantages: simplicity, flexibility, and a very good adequacy.     

Novel Optical Resolution of Phenylalanine Racemate Utilizing Enzyme Reaction and Membrane Extraction

Abstract

A novel optical resolution method for d,l-phenylalanine in which an enzyme reaction and a membrane extraction are combined has been designed. In the first stage only the l-isomer of the racemic phenylalanine methyl ester was selectively hydrolyzed by the enzyme α-chymotrypsin. Further, the unreacted ester was selectively recovered from the mixture of the transferred amino acid and the ester form by a membrane extractor. Effects of operation conditions in the enzyme reaction and the membrane extraction on the separation efficiency were investigated. The pH in the material sources is found to be an important factor in the activity and selectivity for the enzymatic resolution. A novel immobilized enzyme enables the expensive enzyme to be reused in the feed solutions. The hollow-fiber membrane extractor was a good separator for an amino acid and its ester derivative, because only the ester was selectively extracted into an organic phase. The novel separation system becomes a very useful process for the optical resolution of amino acids by combining the enzyme reaction with a membrane extraction.     

铝及铝合金化学浸镀仿金工艺研究

为了拓展铝及铝合金的应用范围,采用二次浸锌+碱性化学镀镍+酸性化学镀镍+化学浸镀仿金的组合工艺,开发了一种新的铝及铝合金化学浸镀仿金工艺,探讨了主要成分和工艺条件对仿金镀层质量的影响,确定工艺条件如下:SnSO48~10 g/L,CuSO41.2~1.5 g/L,配位剂(酒石酸或柠檬酸)10~15 g/L,H2SO410~20 mL/L,XT-08B稳定剂10~12 mL/L,氢氟酸40~50 mL/L,氟化铵1~2 g/L,温度15~35°C,时间10~15 min。所得仿金镀层色泽典雅纯正,结合力好,工艺操作简便,对环境污染小,耐蚀性可与电镀仿金层媲美,具有较好的应用前景。     

2012年上半年我国硫酸磷肥行业运行形势分析

2012年上半年国民经济增速总体放缓,磷肥行业受出口政策收紧的抑制,磷肥产量仅有1.5%的小幅增长,影响了硫酸总体消费量,1—7月全国硫酸产量43 832 kt,增幅下降到5.9%。今年有一批新装置投产,供大于求的形势更加严峻,冶炼酸在硫酸市场上占据优势,硫铁矿制酸依靠烧渣占据一定市场,硫磺制酸受国际高价硫磺影响艰难运行。由于回收硫磺量的增加,加上其他硫资源的回收,我国硫资源对外依存度将有所下降。     

煤制低碳烯烃工业示范工程最新进展

介绍了神华包头煤制低碳烯烃示范工程的工艺总流程,包括煤气化,合成气变换与净化,甲醇合成,甲醇制烯烃,烯烃分离,烯烃聚合生产聚乙烯、聚丙烯等工艺过程。总结该工程在建设和生产运营过程中,开发和掌握了煤制烯烃系统集成技术、工程化技术、开工和运行技术、C4深加工技术、污水处理技术等。文章还介绍了工程商业化运行情况,指出3年的商业化运行结果表明,煤制烯烃示范工程运行安全稳定,并创造了较好的经济效益。总结指出煤制烯烃示范工程的成功运营使中国成为世界上首个掌握此项工业化技术的国家,对中国降低石油和基础化工原料对外依存度具有重要意义。     

膜反应萃取过程酶法拆分N-乙酰-D,L-苯丙氨酸乙酯

<正>手性是自然界的本质属性之一,作为生命活动重要物质基础的生物大分子和许多作用于受体的活性物质均具有手性特征,因此分子的不对称性在生命过程中起着重要作用.近年来,随着不对称合成和手性开关技术的迅速发展,单一对映体的工业化生产成为可能.L-苯丙氨酸是人和动物必需的氨基酸,不能在体内合成,必须从外界摄取,近年来由于它在医药制剂和高甜度天冬甜精等方面的需求量剧增,对其研究和开发日益增多.酶膜反应萃取器集固定化酶膜反应与液液萃取于一体,能大大提高反应和分离效率,Matson、Scheper、Ha、Chang等利用酶膜反应萃取和乳化液膜酶反应过程,已成功地实现了一些消旋物的拆分.本文选择苯丙氨酸的拆分为研究对象,利用酶膜反应萃取过程进行L-苯丙氨酸的合成,探讨过程的可行性和影响因素.     

Theoretical and experimental assessment of a novel method to establish the complete measurement range of the calorimeter and its limit of detection and quantification

For determining the accuracy of a calorimeter over the instrument’s entire measuring range, a novel method has been established. For this new approach, (a) benzoic acid (C₆H₅CO₂H) as a certified reference material (CRM), (b) SiO₂ and (c) a mixture of CRM benzoic acid and SiO₂ have been used. To illustrate the essential difference between 1) the novel analytical method for control of the entire measurement range and 2) the calorimeter calibration, both applications of benzoic acid (BA) have been demonstrated. An experimental result showed that BA was successfully used to check the whole calorimeter measurement range. The results also showed that the same new method was successfully applied to determine the limit of detection and quantification. A new instrument testing process and a new measurement technique have thus been established. In this way, the cost of using CRM to control the accuracy of measuring the entire measuring range of the calorimeter, as shown in this paper, is minimized. The requirements of the ISO/IEC 17025:2017 standard are satisfied. ISO/IEC 17025:2017, together with ISO 9001:2015 (quality management systems), ISO 14001:2015 (relate to environmental protection) and ISO 45001:2018 (occupational safety), constitute an integrated quality system by which a testing laboratory may also accredit.