从沉淀亮氨酸母液中分离硷性氨基酸上柱液pH的选择

<正> 我们在我所曾报道的活性炭——离子交换树脂联合柱层析分离猪血粉水解液中L—苯丙氨酸等多种氨基酸的新工艺基础上,最近又进行了应用国产732强酸性阳离子交换树脂,从沉淀亮氨酸母液中单柱体分离硷性氨基酸,着重于上柱液最佳pH的选的择实验研究,现将研究情况报告如下:     

离子交换法对猪血粉水解液脱酸的研究

作者合成了六种不同骨架或功能基的离子交换树脂,测定了它们的物理化学性能。研究了它们对经AAS系列新型吸附树脂脱色的猪血粉水解液的脱酸性能,并与制药行业中和工艺中通用的330脱酸树脂进行了比较。结果表明,在同样条件下七种树脂的脱酸效果为D3945>D3923>D1534>330≈D1523>D390>D396。本文还讨论了各种条件对脱酸的影响。     

从猪血粉水解液中分离L—酪氨酸

<正> L—酪氨酸(L—Tyrosine)即α—氨基—β—对羟苯基丙酸,在医疗、生化、工业、农业各领域的应用日益广泛。我们在酸水解猪血粉制备混合氨基酸注射液时,酪氨酸因水中溶解度极小而首先被分离,鉴于原料来源广、工艺操作简便,又是综合利用,现阶段有实用意义。故将分离操作和产品鉴定结果报告如下:     

活性炭-离子交换树脂联合柱层析分离猪血粉水解液中L-苯丙氨酸等多种氨基酸的新工艺

<正> 本文报道了活性炭——离子交换树脂联合柱层析分离猪血粉水解液中L-苯丙氨酸等多种氨基酸的新工艺。本工艺将猪血粉水解液通过活性炭柱吸附,依次用IN氨水,适当浓度乙醇解吸得到L-苯丙氨酸,L-酪氨酸;活性炭柱流出液再通过离子交换柱交换吸附,依次用0.05、0.1、2N氨水解吸得到L-组氨酸、L-亮氨酸、L-精氨酸、L-赖氨酸。上述六种氨基酸对猪血粉的百分收率分别为2.5、0.8、5.4、4.1、3.4、2.9。     

AAS系列新型吸附树脂对猪血粉水解液脱色性能的研究

本文采用新型AAS系列吸附树脂代替传统的活性炭,对猪血粉水解液进行脱色。本文研究了AAS树脂的脱色容量、吸附速率、脱色过程中的氨基酸损失量等性能,并与H107、NKA、及活性炭作了对比。实验发现,AAS树脂不仅具有优异的吸附性能,而且再生性能好,使用周期长,再生方法简便。本文还讨论了pH对脱色性能的影响,给出最佳脱色酸度范围为pH1～3。     

猪血粉水解液预处理对碱性氨基酸产量的影响

<正> 一、前言以猪血粉为原料,经盐酸水解后,用一强酸性阳离子交换树脂柱同时分离三种碱性氨基酸的生产工艺,国内已有报道。我们重复国内工艺,发现现行工艺生产周期仍较长,驱酸的彻底性对收率影响较大,由于上柱液pH值不当,在洗脱过程中,洗脱液组份     

活性炭色谱法分离苯丙氨酸、酪氨酸

根据活性炭对苯丙氨酸、酪氨酸的选择性吸附特性和二者在活性炭吸附中的差异,通过活性炭吸附与氨水、乙醇二步解吸的活性炭色谱法从多种氨基酸的猪血粉水解液、棉籽蛋白水解液中成功地分离提取了苯丙氨酸、酪氨酸。活性炭色谱法工艺对提取法、发酵法生产苯丙氨酸具有实用价值。还为联合离子交换色谱法分离水解液中其他氨基酸改善了物料条件,从而较好地解决了树脂毒化问题、氨基酸交叉重选问题,并使洗脱溶液中杂质少、纯度高,易于结晶。     

从猪血粉中系统分离缬氨酸、亮氨酸、组氨酸、赖氨酸和精氨酸

本文报道了运用国产强酸性苯乙烯系阳离子交换树脂从批量400kg猪血粉水解物中,分离缬氨酸、亮氨酸、组氨酸和精氨酸的系统方法。每柱产量达到了缬氨酸4.5kg、亮氨酸12kg、组氨酸5kg和精氨酸6kg以上,赖氨酸产量未统计。本文还研究了两类洗脱剂对分离氨基酸的效果和对产品纯化的影响。指出用NH_4Cl作洗脱剂,分离氨基酸的效果较好,而用NH_3—NH_4Cl作洗脱剂,虽然只能获得氨基酸的部分分离,但是有利于产品的纯化。这两类洗脱剂巧妙地配合,就能够在常温下运用强酸性阳离子交换树脂柱从猪血粉水解液中分别获得缬氨酸与亮氨酸,组氨酸、赖氨酸与精氨酸的分离。产品质量符合注射用结晶氨基酸标准。本方法经过半年的试生产,产量和质量是稳定的,适合于工业化生产。     

酸水解法生产复合氨基酸工艺改进

本文在盐酸、血粉水解生产氨基酸的老工艺基础上,提出了以血浆代替血粉及以H_2SO_4代替HCl的新工艺参数,可使工艺路线缩短,生产成本大为降低。     

AAS系列新型吸附树脂对猪血粉水解液脱色机理的研究

AAS系列新型吸附树脂是猪血粉水解液的优良脱色剂。本文测定了其物理参数与化学结构,建立了结构与性能的关系。并根据色素的溶解性能提出缔合溶解模型与竞争吸附机理,解释了该系列树脂性能优异的原因。     

Influence of amino acid supplements on the metabolism of Clostridium acetobutylicum

The effects of organic nitrogen on the metabolism of Clostridium acetobutylicum were investigated in batch fermentations. For this study, amino acids were added to a chemically defined medium in groups from the same biosynthetic pathways. In all cases the addition of amino acids shifted the solvent ratio to higher butanol production at the expense of that of acetone (except for the glutamic acid group) and ethanol (except for histidine). Highest biomass production was obtained from media containing aromatic amino acids and histidine (4.57 g · l⁻¹ and 5.4 g · l⁻¹, respectively). However, the solvent production (ca. 20 g · l⁻¹) and the solvent yield (ca. 33%) in both cases, were similar to those obtained from the synthetic medium. Lower values were obtained from fermentations carried out with other families of amino acids. The strongest inhibition of cell growth (1.13 g · l⁻¹) which related to the lowest solvent production (3.15 g · l⁻¹) was observed on a medium complemented with amino acids of the pyruvic acid group. During the second phase of fermentation, amino acids-complemented media caused a less efficient remetabolization of acetic and butyric acids. Highest production of acids was obtained with the aspartic acid group (7.4 g · l⁻¹). These observations suggest that amino acids can be used as a competitive nitrogen source and also modify the level of enzyme activities involved in acid and solvent production.     

Amino acids and growth substances in barley root excretions (Hordeum distichon L.) and their biological effect

The biological effect of barley root excretions was studied during a 4 to 10 days cultivation period. The effect of root excretions changes according to the cultivation period of barley. It was ascertained by means of a bioassay that growth was either conclusively stimulated or the root excretions did not affect growth of the roots and of the upper part ofNasturtium. No significant inhibitory effect was observed. The effect of the single amino acids and of their mixtures found in the root excretions of barley was quite different. The following amino acids were determined by paper chromatography in root excretions: alanine, asparagine, phenylalanine, glycine, leucine, lysine, serine, tyrosine, glutamic acid and valine plus methionine. During cultivation their total quantity increased from 5·48. 10^?5 up to 1·13. 10^?3 mg per plant. Most of the 20 amino acids observed, displayed in theNasturtium test at a concentration from 0·1 to 1,000 mg/l an inhibitory effect onNasturtium growth. The effect of amino acid mixtures, corresponding qualitatively and quantitatively to the free amino acids in barley root excretions was dependent on their concentration. Growth regulators of the auxin type were found in culture solutions by chromatographic separation and with bioassay. As it may be seen from the results obtained, there are besides amino acids and indole derivatives other non-identified compounds involved in the effect of barley root excretions.     

脑蛋白粉的制备及其酶解方法的研究

研究了以鲜猪脑制备蛋白粉并进行酶水解的方法 ;脑蛋白粉质量、不同酶和加酶方法对水解结果的影响 ;分析了水解液中游离氨基酸和低分子肽谱 ,并与国内外类似研究进行了比较。结果表明 :丙酮、乙醚沉淀制得的脑蛋白粉含氮 9.0 %～ 1 1 .5% ,脂肪 2 .5%～ 4 .0 % ,适于酶解 ;水解液含有 1 6种游离氨基酸 ,总量达 3 2 .4 4mg/ml和 4个分子量小于 1万的肽。提出精制脑蛋白粉进行水解、减压浓缩、超滤是提高水解液有效成分的技术措施。     

Production of single cell protein using waste capsicum powder produced during capsanthin extraction

Aims: To produce single cell protein (SCP) by using waste capsicum powder produced during capsanthin extraction as a substrate. Methods and results: The extraction [CPM (capsicum powder medium)] from waste capsicum powder was used as culture medium to cultivate four yeast strains. The main composition of CPM was determined. The average concentration of total sugar, total nitrogen and phosphorous of CPM were 16·3, 3·7 g l^?1 and 785·4 mg l^?1, respectively. Four yeast strains were cultured in two CPMs, and the cell mass, protein content of cells and specific growth rate of cells were determined. Addition of corn steep liquor significantly increased the cell mass production. Presence of capsaicin in CPM did not show inhibition of cell growth of yeast tested. Conclusions: CPM contained sufficient nutrients and could be used as a good medium to produce SCP. Candida utilis 1769 was chosen as the biomass producer because of its highest SCP formation (6·8 g l^?1) and higher specific growth rate (0·12 h^?1). The amino acid composition of its protein was well balanced. Significance and Impact of the Study: Utilization of waste capsicum powder can reduce environmental pollution and increase protein supply for animal feed.     

Rôle of single amino acids in phagostimulation,growth, and survival of Acyrthosiphon pisum

Twelve amino acids and amides at 0·1 to 0·75 or 1·0% in 35% sucrose solution were individually tested for their rôle in phagostimulation, growth, and survival in Acyrthosiphon pisum. Leucine and phenylalanine were phagostimulatory at all concentrations tested, tryptophan and valine at 0·1, 0·2, and 0·5%, and threonine at 0·1% only. Methionine was reported earlier by us to be phagostimulatory at 0·05 to 0·5%. Histidine and isoleucine had no effect, whereas arginine and lysine HCl reduced uptake when compared to sucrose alone. The non-essential amino acids, canavanine sulphate and glutamine, reduced uptake at all concentrations, whereas homoserine was phagostimulatory at 0·1 and 0·75%.Arginine, canavanine sulphate, glutamine, histidine, homoserine, isoleucine, leucine, and valine increased weight and prolonged survival, whereas lysine HCl, phenylalanine, threonine, and tryptophan neither promoted growth nor increased survival. Radioactive leucine (¹⁴C(U)) was incorporated into the protein fraction of the larval body and exuviae indicating that it took part in protein synthesis. This seems to be the first report in insects where peptide or protein synthesis occurred from single amino acids in sucrose.     

Patterns of nitrogen utilization between the ambrosia beetle Xyleborus dispar and its symbiotic fungus

Some parameters of nitrogen utilization between the ambrosia beetle Xyleborus dispar in mutualistic association with its symbiotic fungus Ambrosiella hartigii, were examined. Qualitative and quantitative analyses of the major nitrogenous excretory products were made on the various life stages of X. dispar. The main nitrogenous product found in excreta and hindguts of beetles, larvae, and pupae, was uric acid (range 7·6–14·8 μg uric acid/beetle). No ninhydrin-positive compounds were located in excreta of the beetles. The concentration of ammonia-nitrogen in the various life stages averaged between 0·70 and 1·13 μg NH₃-N/beetle.Total nitrogen determinations were made on sapwood samples of Malus sylvestris (0·34 ± 0·005% N by dry weight), attacked wood, ‘pre-brood’ (0·31 ± 0·005% N by dry weight), and attacked wood ‘post-brood’ (0·17 ± 0·02% N). Similar determinations of the artificial medium (l-asparagine medium) indicated that a nitrogen requirement of about 0·08–0·1% N by dry weight was necessary before oviposition could occur.Fixation of atmospheric nitrogen by individual X. dispar beetles in vitro was not indicated using the acetylene ethylene reductase method. Proteolytic enzyme activity was not found on examination of diapause beetles, their excreta, larval and pupal excreta, and the ambrosial and mycelial forms of A. hartigii.Comparative concentrations of soluble proteins and free amino acids suggested that fungus in the mycangia was built up from free amino acids of the insects. At the period of emergence, flight, and attack of new hosts, the females were found to have a concentration of soluble proteins more than double that found in the beetles during the remainder of the year. The free amino acids were the lowest values recorded during this period (March–October).     

乙酰乳酸合成酶的制备、分离与纯化

乙酰乳酸合成酶［１］（ａｃｅｔｏｌａｃｔａｔｅｓｙｎｔｈａｓｅ,ＡＬＳ）是目前国际上除草剂研究的前沿热点．它能催化一分子丙酮酸脱羧并与另一分子丙酮酸缩合成一分子乙酰乳酸,从而导致侧链氨基酸缬氨酸、亮氨酸和异亮氨酸的生物合成．存在于细菌和植物组织中［２...     

测定荔枝核中的游离氨基酸

采用氨基酸自动分析仪测定荔枝核水提取液、醇提取液样品。在醇提取液中游离氨基酸的含量高于水提取液,在两种提取液中共检出了21种游离氨基酸(其中4种为未知氨基酸,6种必需氨基酸);已知游离氨基酸的质量分数为307μg.kg-1(醇提取液)和269μg.kg-1(水提取液),总游离氨基酸的质量分数为500μg.kg-1,必需氨基酸的量占总游离氨基酸量的44%。结论:荔枝核中的游离氨基酸具有利用价值。     

Rapid determination of amino acids in biological samples using a monolithic silica column

A high-performance liquid chromatography method in which fluorescence detection is used for the simultaneous determination of 21 amino acids is proposed. Amino acids were derivatized with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) and then separated on a monolithic silica column (MonoClad C18-HS, 150 mm × 3 mm i.d.). A mixture of 25 mM citrate buffer containing 25 mM sodium perchlorate (pH 5.5) and acetonitrile was used as the mobile phase. We found that the most significant factor in the separation was temperature, and a linear temperature gradient from 30 to 49°C was used to control the column temperature. The limits of detection and quantification for all amino acids ranged from 3.2 to 57.2 fmol and 10.8 to 191 fmol, respectively. The calibration curves for the NBD-amino acid had good linearity within the range of 40 fmol to 40 pmol when 6-aminocaproic acid was used as an internal standard. Using only conventional instruments, the 21 amino acids could be analyzed within 10 min. This method was found to be suitable for the quantification of the contents of amino acids in mouse plasma and adrenal gland samples.     

Analysis of all protein amino acids as their tert.-butyldimethylsilyl derivatives by gas-liquid chromatography

A gas chromatographic method for the separation and quantitation of the 20 protein amino acids is described using N-methyl-N(tert.-butyldimethylsilyl)trifluoroacetamide, with 1% tert.-butyldimethylchlorosilane as catalyst, to prepare the tert.-butyldimethylsilyl amino acid derivatives. Alkylsilylation of amino acids proceeds at 140 degrees C in 20 min. The derivatives formed in the one-step reaction are used directly for gas-liquid chromatographic analysis, using a flame-ionization detector, without prior isolation or purification. Complete separation and quantitation of all protein amino acids are readily achieved using a 15-m DB-5 capillary column. Strict linearity extends from less than 15 to about 100 ng for all amino acids except Arg, which has a linear range from 50 to 300 ng. The limits of detection, however, range from one to several hundred nanograms. The method was used to analyze the free amino acid pool in carnation petals.