L-鸟氨酸的生物功能及生产研究

L-鸟氨酸是人体代谢中必不可少的中间代谢产物，一种非蛋白质氨基酸。鸟氨酸多功能的保健作用使其愈来愈广泛的应用到食品工业和医药工业中。发酵法生产L-鸟氨酸是国内外研究的方向。介绍了L一-鸟氨酸的生物功能及发酵法生产L-鸟氨酸的过程及研究状况，包括产L一鸟氨酸的菌种，发酵条件的摸索及优化和国外L-鸟氨酸的工业化生产情况。     

氨基酸生产技术讲座

九、L-鸟氨酸、L-瓜氨酸、L-精氨酸发酵L-鸟氨酸、L-瓜氨酸和L-精氨酸(以下L-省略)主要用作氨中毒治疗药物和肝功能促进剂。其中精氯酸是含有胍基的碱性氨基酸,对于幼小动物的营养尤其重要,与L-组氨酸合称为半必需氨基酸。早在1957年鹈高就采用谷氨酸棒杆菌的瓜氨酸缺陷株发酵生产鸟氨酸获得成功。1964年奥村等报道枯草杆菌K的精氨酸缺陷株积累著量的瓜氨酸。1966年鹈高等发现了大肠杆菌变异株的精氨酸分泌,然而精氨酸的大量积累则是近十年的事情。现在,这三种氨基酸部主要以发酵法生产,前两者的世界年产量各达50吨,后者则为500吨以上。本章拟叙述鸟氨酸、瓜氨酸和精氨酸的生物合成途径、调节机制,以及用于这三种氨基酸发酵生产的各类变异株,并介绍转导在精氨酸高产菌选育中的应用。     

微生物发酵法生产鸟氨酸

本文介绍了鸟氨酸的生物合成途径及代谢控制育种理论，提出了鸟氨酸积累突变株应具有瓜氨酸或精氨酸缺陷及精氨酸结构类似等遗传标记，并介绍了鸟氨酸的发酵研究情况。     

L一鸟氨酸纸层析定量测定法的研究

本文建立了一种纸层析定量测定L-鸟氨酸的新方法,用苯酚氨水水=511为展开剂能将L-鸟氨酸从发酵液中分开;确定了采用茚三酮为显色剂,90℃～100℃显色5min,硫酸铜乙醇洗脱液洗脱10min后比色等测定条件,并发现滤纸上L-鸟氨酸含量为5～40μg比较合适;绘制了L-鸟氨酸标准曲线,并推出发酵液中L-鸟氨酸含量的计算公式为X=38.46×A×n/v.     

L-鸟氨酸生产菌的选育及其发酵条件的研究

以谷氨酸棒杆菌为出发菌株 ,经硫酸二乙酯、紫外线诱变 ,定向选育出一株鸟氨酸生产菌A1157,其遗传标记为Arg- +D Argr+SGr,并能耐受高浓度葡萄糖。对菌株A1157的发酵条件进行了研究 ,在最佳培养条件下 ,该菌株L 鸟氨酸产量可达 9.85g/L。     

DPS数据处理系统在L-鸟氨酸发酵培养基优化中的应用

利用正交设计与均匀设计试验方法,并采用DPS软件对实验结果进行分析,得出石蜡节杆菌WZFF.X-146菌株生产L-鸟氨酸的最适批式摇瓶发酵培养基配方。结果表明,DPS软件在L-鸟氨酸发酵培养基优化方面取得良好的效果,产酸水平达到19.91g/L,提高了125%以上。     

利用比较基因组学研究弗尼斯弧菌和霍乱弧菌在鸟氨酸脱羧酶试验中不同表型的分子遗传基础

目的:弗尼斯弧菌(Vibrio furnissii)是近年来国内外学者公认的新食源性致病菌,对全球公共卫生和食品安全造成潜在威胁。鸟氨酸脱羧酶试验是区分弗尼斯弧菌和霍乱弧菌的特征性生化指标之一。利用比较基因组学寻找并利用回补试验验证二者鸟氨酸脱羧酶试验差异的分子遗传机制,为今后食品中致病微生物生化反应的基因检测提供分子依据。方法:利用比较基因组学分析弗尼斯弧菌NCTC11218和霍乱弧菌N16961在鸟氨酸脱羧代谢通路中的基因差异。随后,构建携带外源霍乱弧菌基因的弗尼斯回补菌株,利用生化条API20E验证弗尼斯野生株和回补株在鸟氨酸脱羧酶试验中的结果。结果:通过比较基因组学分析发现弗尼斯弧菌缺乏含鸟氨酸脱羧酶基因及腐胺/鸟氨酸逆向转运体基因的整个操纵子区域,弗尼斯弧菌回补株在鸟氨酸脱羧酶试验中呈现阳性。结论:推测弗尼斯弧菌在鸟氨酸脱羧试验中呈现阴性表型的遗传基础,是因其基因组中不存在完整的含有鸟氨酸脱羧酶基因及腐胺/鸟氨酸逆向转运体基因的操纵子序列。     

L-鸟氨酸的细胞转化制备及在卷烟中的应用

利用工程菌中的精氨酸酶转化制备L-鸟氨酸。分析了pH、温度、金属离子、底物浓度等因素对L-鸟氨酸产量的影响。试验结果得出最佳工艺为:pH 10,温度40℃,Mn2+添加量5 mmol/L及L-精氨酸浓度50 g/L,L-鸟氨酸的产量达35.1 g/L,在优化条件下细胞可连续使用4次,且产量稳定。在卷烟中的应用初步研究结果表明:当其用量为0.03%时综合效果最好。     

3-磷酸甘油醛脱氢酶促进谷氨酸棒杆菌发酵生产L-精氨酸和L-鸟氨酸

在谷氨酸棒状杆菌(Corynebacterium glutamicum) SNK118中表达NADP~+依赖型的3-磷酸甘油醛脱氢酶编码基因,提高胞内NADPH水平,以提高L-精氨酸(L-Arginine)和L-鸟氨酸(L-Ornithine)发酵产量。通过NCBI数据库检索,选取了3个不同来源的3-磷酸甘油醛脱氢酶编码基因。经测定酶活力,最终选择糖丁基梭菌(Clostridium saccharobutylicum) DSM 13864来源的NADP~+依赖型的3-磷酸甘油醛脱氢酶基因(Csgap C)。构建了产L-精氨酸的重组菌SNK118/p XMJ19-Csgap C,当摇瓶发酵70 h时产L-精氨酸11. 55 g/L,糖酸转化率0. 13 g/g,与对照菌SNK118/p XMJ19相比,精氨酸产量和糖酸转化率分别提高了26%和10. 2%。在L-鸟氨酸生产菌株SNK118Δarg FΔargR中重组表达Csgap C,重组菌SNK118Δarg FΔargR/p XMJ19-Csgap C摇瓶发酵70 h产L-鸟氨酸27. 76 g/L,糖酸转化率0. 274 g/g,与对照菌SNK118Δarg FΔargR/p XMJ19相比,L-鸟氨酸产量和糖酸转化率分别提高了20. 1%和15. 6%。结果表明,异源表达Csgap C有助于提高谷氨酸棒杆菌发酵生产L-精氨酸和L-鸟氨酸的水平。     

L-鸟氨酸发酵用培养基的改进研究

利用价格低廉的废酵母制作酵母水解液替代酵母浸膏做有机氮源,加入丁二酸做调控物对产L-鸟氨酸的谷氨酸棒杆菌进行发酵培养。结果表明,使用废酵母作为有机氮源后,L-鸟氨酸的产量增加了26.4%。加入1.0%的丁二酸,L-鸟氨酸的产量提高了10.4%。     

蛋白质水解度测定方法综述

对目前国内外常用的蛋白质水解度测定方法进行了综述，其中pH—state方法是通过滴定水解过程中释放的质子测定DH；OPA、TNBS及国内常用的水合茚三酮和甲醛等测定方法是利用游离氨基的反应测定DH。     

SEROLOGIC IDENTIFICATION OF SPECIES OF ORIGIN OF SAUSAGE MEATS

SUMMARY: A partially purified immunoglobulin G (lgG) solution prepared from the serum of species to be tested was heated to the specifications for sausages. The resulting supernatant fluid was decanted and the precipitate washed with saline and used to immunize rabbits. The supernatant fluid was used to sensitize tanned sheep red blood cells. The immune serum was rendered monospecific by absorptions with heterologous, heated lgG precipitates. A sample of monospecific immune serum was absorbed with a washed homogenate of sausage. Aliquots of the monospecific immune serum, both untreated and sausage absorbed, were tested with cells sensitized with the homologous heated lgG supematant fluid. A significant reduction of titer by sausage absorption indicated that the sausages contained the meat homologous to the immune serum.     

BASIS OF STABILITY OF AMINE SALTS OF LINOLEIC ACID

SUMMARY— The mechanism and generality of the known stabilization against autoxidation conferred on linoleic acid by certain basic amino acids, such as lysine and arginine, was investigated. Basic amino acids were the only class of compounds found to confer the effect. However, the smallest basic amino acid, 2,3-diaminopropionic acid, was not effective, nor was αβω-diaminc acid, 3,6-diaminohexanoic acid, although a simple isomer of lysine. The stabilization was observed only in the solid phase. Inclusion of sodium chloride in the solid matrix was deleterious to the effect. A large number of physical and chemical observations were made and correlated but it has not been possible to draw detailed conclusions about the mechanism of stabilization, nor can a detailed structure of the stabilized complex be suggested. The cause of the phenomenon appears to be closely associated with the physical arrangement of the ions in the crystal lattice.     

百年风尚

一场流光溢彩、赏心悦目的展览,一段百年风尚演进的传奇旅程,一次东西方文化艺术的完美对话。2013年9月13日,“博萃臻艺一中西方珍宝艺术展”在辽宁省博物馆举行了隆重的开幕仪式,法兰西共和国驻华大使白林女士、辽宁省文物局局长丁辉先生、辽宁省博物馆馆长马宝杰先生、卡地亚全球总裁兼首席执行官邓阁仕先生、卡地亚区域行政总裁（北亚洲）陆慧全先生、卡地亚中国区首席执行官陆意斯先生、辽宁省文物店总经理张春鹰先生,以及众多文化界与文博界的贵宾齐聚一堂,共同见证了这场文化艺术盛事。     

聚多元羧酸盐的合成及应用

研究了聚多元羧酸盐的合成方法及反应机理,将其应用于洗涤剂和PVC制品中分别代替三聚磷酸钠和邻苯二甲酸二丁酯,证明有良好效果。     

DEVELOPMENT OF CHAINS OF CELLS OF SACCHAROMYCES CEREVISIAE DURING FERMENTATION

The lengths of chains of cells of Saccharomyces cerevisiae were studied during fermentation. Pitching yeast generally contained about half of the total number of cells as two-celled chains. The chain lengths varied during the subsequent fermentation and the variations were characteristic of the strain. Electronic counting assessments of chain length were unreliable.     

STABILITY OF AQUEOUS EMULSIONS OF THE ESSENTIAL OIL OF HOPS

Hop oil emulsions prepared from different varieties of hops have been found to exhibit enhanced physical stability on the addition of blends of the emulsifiers Span 20/Tween 80 or Span 60/Tween 60. Examination of the particle size and volume distributions of an emulsion by use of a Coulter Counter was found to be an excellent method of monitoring its stability. An indication as to the relative efficiency of emulsifiers can be obtained from Coulter Counter measurements on hop oil emulsions after storage for 4 days. The use of an ultracentrifuge provies a rapid means of testing emulsion stability and hence the effectiveness of emulsion stabilizers.     

EFFECTS OF TYPES OF FAT AND OF RATES AND TEMPERATURES OF COMMINUTION ON DISPERSION OF LIPIDS IN FRANKFURTERS

ABSTRACT— The effect of time, temperature and rpm of comminution of emulsions was determined on the dispersion of approximately 25% of beef fat, pork fat or cottonseed oil in frankfurters. The numbers of lipid particles 5 μ or less in diameter increased in frankfurters containing either beef or pork fat as comminution was continued to higher temperatures, with pork fat dispersed more thoroughly. Fat tended to separate from frankfurters containing beef fat in particles 200 μ or more in diameter. In contrast, no specific degree of dispersion of particles 5 μ or less in diameter consistently indicated emulsion stability, or its lack. Increased rpm during comminution produced an increased dispersion of beef or pork fat. Under the same conditions pork fat was dispersed more finely than beef fat. Dispersion of cottonseed oil produced finely dispersed particles beyond the resolution of light microscopy, as was confirmed by electron microscopy which showed a substantial number of particles to be less than 1 μ in diameter.     

矩阵乘积的行式,列式

给出了ｍ×ｍ矩阵与ｍ×ｎ矩阵的行（列）式的表达式．若Ａ＝ａ１１ａ１２…ａ１ｍａ２１ａ２２…ａ２ｍ……ａｍ１ａｍ２…ａｍｍＢ＝ｂ１１ｂ１２…ｂ１ｎｂ２１ｂ２２…ｂ２ｎ……ｂｍ１ｂｍ２…ｂｍｎ分别是ｍ×ｍ，ｍ×ｎ矩阵，则｜Ａ｜｜Ｂ｜＝｜ＡＢ｜＋∑ｉ１＜ｉ２＜…＜ｉｔｊ１＜ｊ２＜…＜ｊｔ１≤ｔ≤ｍｎ－ｔ≥ｍＮＢｉ１ｉ２…ｉｔｊ１ｊ２…ｊｔＮＡＢ１…ｍ（－１）ｓｔ＋１ｊｔ＋１…（－１）ｓｎｊｎ其中ｉ１，ｉ２，…，ｉｔ是１，２，…，ｍ中ｔ个数码；ｊ１，ｊ２，…，ｊｔ，ｊｔ＋１，…，ｊｎ是１，２，…，ｎ的一个排列；ｓｒ＝π（ｊ１，ｊ２，…，ｊｔ，ｊｒ）（ｒ＝１，２，…，ｎ）是排列ｊ１，ｊ２，…，ｊｔ，ｊｒ的反序数．     

ANALYTICAL CHARACTERIZATION OF THE PRODUCTS OF NONENZYMATIC GLYCOSYLATION OF LYSOZYME

The quantitative analysis of the reaction products of the water activity dependent nonenzymatic glycosylation of lysozyme was not straightforward. Difficulties arose in the determination of the number of bound glucose molecules because glycosylation leads to glucose mediated protein aggregation, and the likely presence of a mixture of relatively labile Schiff-base intermediates, and the more stable ketoamine products generated by Amadori rearrangement. Polyacrylamide gel electrophoresis was used to monitor protein aggregation; periodate oxidation, nuclear magnetic resonance (NMR), and oxalic acid hydrolysis combined with HPLC, emerged as the most promising methods to quantitate the degree of glycosylation. Possible interpretations are advanced to explain the apparent discrepancies in degree of glycosylation suggested by the different analytical methods evaluated.