秦巴山区野生金荞麦的营养及有效成分研究

对秦巴山区野生金荞麦Fagopyrum cymosum营养成分和有效成分进行分析。结果表明,秦巴山区野生金荞麦营养丰富、有效成分(表儿茶素、芦丁等)含量较高。其中,粗蛋白含量较高,达20.03%,可作为高蛋白的金荞麦育种材料;金荞麦氨基酸总量为15.78%,其中必需氨基酸含量为5.54%,非必需氨基酸含量为10.24%,是一种氨基酸含量较丰富的资源植物。秦巴山区野生金荞麦可作为优良野生牧草资源与药用兼备的多用途植物,具进一步开发利用价值。     

蟹味菇与棕灰口蘑氨基酸组分分析

目的:通过对蟹味菇和贵州产野生棕灰口蘑中的氨基酸组分进行分析来探求其在营养方面的价值。方法:采取酸水解法对氨基酸组分进行分析。结果:研究发现,在这两种食用菌中所含的人体必需氨基酸占各自总氨基酸含量的比例为55.44%和39.44%;相同质量的二者相比较,棕灰口蘑中氨基酸总量明显少于蟹味菇的氨基酸总量。结论:这两种食用菌具有一定的营养保健功能和开发应用价值。     

藜的营养成分及作为新型蔬菜资源的评价

对藜的营养成分进行了测定并对其作为新型蔬菜进行了评价。藜具有较高含量的维生素C,β-胡萝 卜素,以及Fe、Zn、Mn和Cu等微量元素,氨基酸的种类达17种,其中7种为人体必需氨基酸。藜种子中粗脂 肪的含量是16．4％,含有多种油酸,其中亚油酸和亚麻酸是人体必需脂肪酸,尤其是亚油酸含量高达 53．86％。还讨论了藜的生物学特性、对环境的适应性及食用处理方法。并认为藜是一种很有开发利用前景 的野生蔬菜资源。     

人工饲养蕲蛇与野生蕲蛇中重金属元素及氨基酸含量的比较研究

目的:对人工饲养蕲蛇与野生蕲蛇中重金属元素及氨基酸含量进行测定和比较分析研究。方法:采用原子吸收法对蕲蛇中Cu、Hg、Cd、Pb、As含量进行测定;全自动氨基酸分析仪测定蕲蛇中氨基酸含量并进行相关性分析。结果:人工饲养蕲蛇与野生蕲蛇中重金属元素含量为均低于《中国药典》2010版限定值。人工饲养蕲蛇与野生蕲蛇中的氨基酸含量丰富,种类构成完整,均含有17种人体所需要的氨基酸,两者氨基酸含量的相关系数r=0.9991。结论:人工饲养蕲蛇与野生蕲蛇氨基酸含量和组成相似,两者存在线性正相关关系,且蕲蛇中重金属含量符合《中国药典》2010版标准,人工饲养蕲蛇可以作为野生蕲蛇的优良替代品。     

L-异亮氨酸产生菌的选育

为检测不同产地天麻中氨基酸的含量差异,采用日立L-8800氨基酸自动分析仪对7个分别产自四川荥经县、剑阁县和云南小草坝的野生及引种天麻品种的氨基酸含量进行了测定.结果显示,7种天麻的氨基酸种类丰富且含量均较高,其中以四川荥经县野生样品中氨基酸含量最高,四川荥经县引种云南小草坝样品中氨基酸含量最低.结果表明,不同产地的天麻中氨基酸的含量存在差异.     

五种野生食用菌干品营养及鲜味成分分析和评价

对野生松蘑、牛肝菌、白蘑、鸡爪蘑、肉蘑五种食用菌子实体中的蛋白质氨基酸、游离氨基酸和呈味核苷酸进行测定,采用氨基酸评分(AAS)、化学评分(CS)、必需氨基酸指数(EAAI)和等鲜浓度(EUC)评价方法,对五种野生食用菌的营养和鲜味进行评价。结果表明:野生食用菌的AAS、CS、EAAI、EUC存在明显差异。白蘑营养及鲜味最好,其余依次为松蘑、鸡爪蘑、牛肝菌,肉蘑最差。     

五种野生食用菌干品营养及鲜味成分分析和评价北大核心CSCD

对野生松蘑、牛肝菌、白蘑、鸡爪蘑、肉蘑五种食用菌子实体中的蛋白质氨基酸、游离氨基酸和呈味核苷酸进行测定,采用氨基酸评分(AAS)、化学评分(CS)、必需氨基酸指数(EAAI)和等鲜浓度(EUC)评价方法,对五种野生食用菌的营养和鲜味进行评价。结果表明:野生食用菌的AAS、CS、EAAI、EUC存在明显差异。白蘑营养及鲜味最好,其余依次为松蘑、鸡爪蘑、牛肝菌,肉蘑最差。     

诸葛菜的营养成分及作为新型蔬菜的评价

诸葛菜「Ｏｒｙｃｈｏｐｈｒａｇｍｕｓ ｖｉｏｌａｃｅｕｓ（Ｌ．）Ｏ．Ｅ．Ｓｃｈｕｌｚ」的营养成分中,具有较高含量的生素Ｃ,β－胡萝卜素以及Ｆｅ,Ｚｎ等微量元素,氨基酸的种类在１９种,其中７种为必需所基酸。诸葛菜种子发芽率高,营养生长期长达７个月。文中讨论了诸葛菜的生物学特性,生态适应性及食用处理方法,讨为诸葛菜是一种很有开发利用前景的野生蔬菜。     

苣苣菜的营养成分测定

分析测定了山东中部野生苣苣菜的营养成分 ,结果表明 ,其主要营养成分含量与常见蔬菜相当或较高 ,并含有 1 8种氨基酸 ,其中包括 8种必需氨基酸 ,EAA/TAA =3 7.3 % ,接近WHO/FAO参考蛋白模式     

Gynura属3个野生蔬菜营养成分的比较及评价

测定了Gynura属中3个野生蔬菜的营养成分,结果表明,红凤菜有最高的粗蛋白和氨基酸总量,并且富含钾.白子菜-1的Vc含量明显最高,β-胡萝卜素和VE也高于白子菜-2和红凤菜.白子菜-2的粗纤维、粗脂肪、灰份、总黄酮的含量都略高于另外两个野生蔬菜.     

海南野生石斛中必需微量元素与必需氨基酸的分析

本文对几种海南野生石斛(红头金石斛、重唇石斛、流苏金石斛、华石斛、密花石斛、刀叶石斛)及人工栽培的金钗石斛,进行了人体及植物必需微量元素和人体必需氨基酸的含量分析.结果表明:每种石斛中均含有植物和人体所需的7种微量元素和7种人体必需氨基酸,其中流苏金石斛的微量元素和氨基酸含量均高于其他种.人工栽培的金钗石斛其微量元素和氨基酸含量与海南野生石斛比较,差异不大,仅在Fe、Mn两个元素均低于野生种.本文还进行了植物必需微量元素与必需氨基酸相关性的讨论.     

湛江常见野菜安全可食性探讨

对湛江野菜所含的硝酸盐、维生素C、胡萝卜素及氨基酸进行了测定和分析。结果表明,刺苋和野当归富含维生素C和胡萝卜素,硝酸盐含量较低,实为品质上乘野蔬。东风菜和枸杞虽然胡萝卜素含量很高,但前者维生素C和氨基酸含量较低,后者硝酸盐含量已超过三级蔬菜标准。不宜大量食用。其余几种野菜营养成分比传统蔬菜高,属于安全食用性野菜。     

人工培养蛹虫草与野生冬虫夏草氨基酸含量的比较

对人工培养蛹虫草与青海产野生冬虫夏草的氨基酸含量进行测定,结果表明:野生冬虫夏草中所含有的各种氨基酸,在人工培养虫草的子实体及菌丝体中都有存在;且后者的精氨酸及脯氨酸含量明显高于野生冬虫夏草。由此为鉴定人工培养虫草的质量,进一步为工业规模开发与利用人工培养虫草,提供了科学理论依据。     

The accumulation of deleterious mutations in rice genomes: a hypothesis on the cost of domestication

The extent of molecular differentiation between domesticated animals or plants and their wild relatives is postulated to be small. The availability of the complete genome sequences of two subspecies of the Asian rice, Oryza sativa (indica and japonica) and their wild relatives have provided an unprecedented opportunity to study divergence following domestication. We observed significantly more amino acid substitutions during rice domestication than can be expected from a comparison among wild species. This excess is disproportionately larger for the more radical kinds of amino acid changes (e.g. Cys<-->Tyr). We estimate that approximately a quarter of the amino acid differences between rice cultivars are deleterious, not accountable by the relaxation of selective constraints. This excess is negatively correlated with the rate of recombination, suggesting that 'hitchhiking' has occurred. We hypothesize that during domestication artificial selection increased the frequency of many deleterious mutations.     

A rapid method for determining tRNA charging levels in vivo: analysis of yeast mutants defective in the general control of amino acid biosynthesis.

We describe a simple method to quantitate the intracellular levels of charged tRNA species representing all 20 amino acids. Small RNA species are isolated from yeast cells under conditions where amino acids remain bound to their cognate tRNAs. After chromatographic removal of free amino acids, the tRNAs are discharged, and the amounts of the released amino acids are then quantitated. This method was applied to yeast cells from a wild type strain and from three mutant strains that are defective both in the general control of amino acid biosynthesis and in protein synthesis. Two of these mutant strains, previously shown to be defective in the methionine or isoleucine tRNA synthetases, respectively contain undetectable amounts of charged methionine or isoleucine although their levels of the remaining 19 amino acids are similar to a wild type strain. In contrast, a gcd1 mutant strain has normal levels of all 20 amino-acyl tRNA species. Thus, gcd1 strains are defective in general control of amino acid biosynthesis for reasons other than artifactual starvation of an amino acid due to a failure in tRNA changing.     

A relationship between free amino acid and nickel contents in leaves and seeds ofAlyssum bertolonii

Summary Data are given on the aqueous acetone—soluble (free) amino acid composition and total nickel contents of leaves of wild and cultivatedAlyssum bertolonii and of seeds produced by the former. Leaves of the wild plants show a direct relationship between their total free amino acid N and Ni contents. These are highest in February, show a decrease in June and increase again by October. It is inferred that variations in the Ni uptake and free amino acid contents are functions of seasonal factors. Leaves of cultivated plants showed the lowest Ni content but the highest free amino acid content illustrating the influence of environmental factors.     

蔓荆子野生品及不同采收期栽培品氨基酸成分分析

目的比较蔓荆子野生品及不同采收期栽培品中氨基酸成分及含量。方法色谱柱3μm×4.6 mm×60 mm,缓冲液流量0.4 m1.min-1,茚三酮流量0.3 m1.min-1,分析时间30 min。结果蔓荆子生药材中检出17种氨基酸,野生与栽培蔓荆子中氨基酸总量分别为32.5 g.kg-1和46.5 g.kg-1,8月下旬、10月中旬、12月中旬3个采收期栽培蔓荆子中氨基酸总量分别为44.7 g.kg-1、47.5 g.kg-1和47.2 g.kg-1。结论蔓荆子中氨基酸总量与其生长环境及方式有关,栽培品质量优于野生品;不同采收期蔓荆子中氨基酸总量无明显差异。     

Isolation of a Bacillus stearothermophilus mutant exhibiting increased thermostability in its restriction endonuclease.

A procedure was developed for the selection of spontaneous mutants of Bacillus stearothermophilus NUB31 that are more efficient than the wild type in the restriction of phage at elevated temperatures. Inactivation studies revealed that two mutants contained a more thermostable restriction enzyme and one mutant contained three times more enzyme than the wild type. The restriction endonucleases from the wild type and one of the mutants were purified to apparent homogeneity. The mutant enzyme was more thermostable than the wild-type enzyme. The subunit molecular weight, amino acid composition, N-terminal and C-terminal amino acid residues, tryptic peptide map, and catalytic properties of the two enzymes were determined. The two enzymes have similar catalytic properties, but the molecular size of the mutant enzyme is approximately 6 to 7 kilodaltons larger than that of the wild-type enzyme. The mutant enzyme contains 54 additional amino acid residues, of which 26 to 28 are aspartate/asparagine, 8 to 15 are glutamate/glutamine, and 8 to 9 are tyrosine residues. The two enzymes contained similar amounts of the other amino acids, identical N-terminal residues, and different C-terminal residues. Tryptic peptide analyses revealed a high degree of homology between the two enzymes. The increased thermostability observed in the mutant enzyme appears to have been achieved by a mutation that resulted in the addition of amino acid residues to the wild-type enzyme. A number of mechanisms are discussed that could account for the observed difference between the mutant and wild-type enzymes.     

Reduced amino acid content in transgenic potato tubers due to antisense inhibition of the leaf H+/amino acid symporter StAAP1

Transport processes across the plasma membrane of leaf vascular tissue are essential for transport and distribution of assimilates. In potato, leaves are the predominant sites for nitrate reduction and amino acid biosynthesis. From there, assimilated amino acids are exported through the phloem to supply tubers with organic nitrogen. To study the role of amino acid transporters in long-distance transport and allocation of organic nitrogen in potato plants, a gene encoding a functional, leaf-expressed amino acid permease StAAP1 was isolated. Similar to the sucrose transporter SUT1, StAAP1 expression was induced during the sink-to-source transition, indicating a role in phloem loading. To test the role of StAAP1, expression was inhibited by an antisense approach. Transgenic plants with reduced StAAP1 expression were phenotypically indistinguishable from wild type, as were photosynthetic capacity and tuber yield. However, tubers from antisense StAAP1 plants showed up to 50% reduction in free amino acid contents. In comparison, starch content was not affected or tended to increase relative to wild type. The reduction in all amino acids except aspartate in the antisense plants is consistent with the properties of amino acid permeases (AAPs) found in heterologous systems. The results demonstrate an important role for StAAP1 in long-distance transport of amino acids and highlight the importance of plasma membrane transport for nutrient distribution in plants.