High Yield and High Selectivity of Reactions in the Frozen State--the Acceptor Reaction of Dextransucrase

Acceptor reactions catalysed by dextransucrase in general yield mixtures of oligosaccharides. Specificity improves with decreasing reaction temperature. Reactions in the frozen state surprisingly give much better yield and selectivity by factors of 2-5.     

远端霉素高产菌株的选育

目的：选育远端霉素高产菌株。方法：以远端霉素产生菌（Streptomyces distallicus）D32为出发菌株,经铜蒸汽激光和5-氟尿嘧啶（5-fu）及其复合处理。结果：在复合诱变组中获得一株远端霉素高产稳产突变株DZ-206,经发酵罐应用后,其产率较出发菌株提高1．38倍。结论：该方法诱变谱广,突变率高,能够快速有效获得抗生素高产菌株。     

高产淀粉型甘薯新品种徐薯27的选育及品质特性

高产淀粉型甘薯新品种徐薯27是以徐薯18为母本,选择遗传背景差异大的20个品种(系)为父本,放任授粉集团杂交后代中筛选。该品种2009年通过山东省农作物品种审定委员会审定。通过对徐薯27农艺性状特征、生产力、抗病性、品质特征性状以淀粉糊化特性等进行研究,结果表明:徐薯27萌芽性好,地上部长势平稳,耐贮藏;高抗根腐病,中抗茎线虫病;鲜薯和薯干产量对照徐薯18,最高增产分别达19.41%和19.21%,具有超高产潜力;徐薯27淀粉RVA谱为A型,不同肥料处理下RVA参数值差异明显,有机肥能明显降低其淀粉最高粘度值(PKV)、最低粘度值(HPV)和最终粘度值(CPV),糊化温度在较高的75～80℃范围。     

High resolution scintiautoradiography

An electron microscopic scintiautoradiographic method for studying histological sections is reported. An increase in the silver grain yield is attained by using a scintillator in embedding medium. The amplification effect for 3H-labeling reaches 3-fold and for 14C reaches a 15-fold. No lessening of autoradiographic resolution was observed. On the basis of these preliminary results only qualitative evaluation of data is discussed.     

High yield chromatographic purification of enzymatically produced tyrosine fructosyl ester

The synthesis of L-tyrosine fructosyl ester, from fructose and L-tyrosine methyl ester, was carried out by a transesterification reaction catalyzed by α-chymotrypsin in water without any organic cosolvent. The yield was optimized by regulating the pH?of the reaction medium and a maximum yield of 63% was obtained. A two-step process of tyrosine fructosyl ester purification was proposed using adsorbent resin and activated carbon. Different elutions and supports easily applicable to industrial process have been studied. Solutions of tyrosine fructosyl ester with a 96% purity and 70% recovery yield were obtained by chromatography on a column of acrylic polyester resins with a solution of 0.5?M NaCl as eluant.     

Enzymatic Synthesis of 5-Methyluridine from Adenosine and Thymine with High Efficiency

5-Methyluridine (5MU) was synthesized efficiently from adenosine, thymine, and phosphate by a combination of adenosine deaminase (ADA), purine nucleoside phosphorylase (PUNP), pyrimidine nucleoside phosphorylase (PYNP), and xanthine oxidase (XOD). Adenosine was converted into inosine first by ADA. 5MU and hypoxanthine were synthesized from inosine and thymine by PUNP and PYNP. The hypoxanthine formed was converted into urate via xanthine by XOD. After inosine was completely consumed, an equilibrium state, in which 5MU, thymine, ribose-1-phosphate, and phosphate were involved, was achieved. At the equilibrium state, the maximum yield of 5MU was obtained. The yield of 5MU was 74%, when the initial concentrations of adenosine, thymine, and phosphate were 5 mM each. On the other hand, in the absence of ADA or XOD the yield of 5MU was 1.8%. Several kinds of nucleosides were also synthesized with high yield by the same method.     

脱落酸对水稻抽穗开花期高温胁迫的诱抗效应

为探究脱落酸(ABA)对水稻(Oryzasativa)抽穗开花期高温胁迫的诱抗效应,以江西省主推水稻品种黄华占为材料,于孕穗期用蒸馏水、ABA溶液(10、50和100μmol·L^-1)、氟啶酮(FLU)和原花青素(PC) 6种溶液进行叶面喷施,然后移入对照(CK)和高温胁迫(HS)环境处理8天,考查籽粒活性氧(ROS)积累、抗氧化防御能力、产量构成及相关基因的表达。结果表明,高温胁迫下,水稻的穗长、穗重、结实率、千粒重和产量与超氧阴离子和过氧化氢含量呈显著负相关。高温胁迫下,喷施ABA显著上调了ABA应答和抗氧化防御基因的表达,籽粒中活性氧含量下降了8.24%–31.35%;喷施ABA显著增加了水稻的穗长、穗重、结实率和千粒重,显著上调了产量形成基因的表达,增产12.73%–20.77%。高温胁迫下,喷施FLU可抑制ABA的生物合成,导致ROS过量积累和水稻减产;喷施抗氧化剂PC则抑制ROS过量积累,使产量增加。以上结果表明,高温胁迫下,孕穗期喷施ABA不仅能够激发ABA信号通路,而且上调抗氧化防御能力和产量形成基因的表达,进而提高水稻在抽穗开花期的耐热性,达到增...     

High yield synthesis of tentoxin, a cyclic tetrapeptide.

Tentoxin is a naturally occurring phytotoxic cyclic tetrapeptide excreted by fungi of the Alternaria alternata family. The four total syntheses of tentoxin published to date give poor total yields, mainly owing to two difficulties, the introduction of the dehydro amino acid and more especially the cyclization step. Here we describe a method that stereospecifically introduces Z-dehydrophenylalanine (deltaZPhe) by a modified Erlenmeyer aldolization reaction. The linear tetrapeptide, Boc-R1Ala-Leu-R2deltaZPhe-G1y-OMe (R1, R2: CH3, 14CH3), the precursor of tentoxin, was obtained in a 72% yield from Boc-Leu-Gly-OH. This linear tetrapeptide, labelled with carbon-14, was used for a comparative study of four cyclization reagents DPPA, DCC-PfpOH, HBTU and HATU. This last was the most effective and gave tentoxin in a 81% cyclization yield. The activated ester formed with this reagent displayed an enhanced capacity for cyclization, permitting cyclization in concentrated medium (10 mM). This new synthetic route gave tentoxin in a 60% yield from Boc-Leu-Gly-OH and offers a means of achieving the synthesis of hitherto elusive analogues.     

大豆高光效育种研究进展

多年的研究证明,提高光合效率是提高大豆产量的重要途径.在高产条件下,高光效大豆(Glycine max L. Merr.)品种与一般品种相比可提高产量30%～40%,表明高光效育种有着广阔的发展前景.高光效育种虽然未能缩短育种时间,但为达到预定的高光效目标提供了"实时"监测,可免除目标的偏离,从而达到高光效与高产的同步提高.大豆叶片与豆荚均存在着高活性的有限的C4途径循环,因此,通过常规育种或基因工程技术提高C4途径酶的表达能力,可能是提高C3植物光合效率的新突破点.     

大豆高光效育种研究进展

多年的研究证明 ,提高光合效率是提高大豆产量的重要途径。在高产条件下 ,高光效大豆 (GlycinemaxL .Merr.)品种与一般品种相比可提高产量 30 %～ 40 %,表明高光效育种有着广阔的发展前景。高光效育种虽然未能缩短育种时间 ,但为达到预定的高光效目标提供了“实时”监测 ,可免除目标的偏离 ,从而达到高光效与高产的同步提高。大豆叶片与豆荚均存在着高活性的有限的C4 途径循环 ,因此 ,通过常规育种或基因工程技术提高C4 途径酶的表达能力 ,可能是提高C3 植物光合效率的新突破点。     

High Light-Induced Reduction and Low Light-Enhanced Recovery of Photon Yield in Triazine-Resistant Brassica napus L

Triazine-resistant and -susceptible Brassica napus L. plants grown under low photon flux density (PFD) have previously been shown to exhibit a similar photon yield. In contrast, high PFD-grown resistant plants have a lower photon yield than high PFD-grown susceptible plants (JJ Hart, A Stemler [1990] Plant Physiol 94: 1295-1300). In this work we tested the hypothesis that high PFD can induce a differential decrease in photon yield in low PFD-grown plants. We measured photon yield, variable fluorescence/maximum fluorescence, and O₂ flash yield in low PFD-grown resistant and susceptible leaf discs before and after exposure to high PFD exposure. The results demonstrated that high PFD exposure results in a greater decrease in photosystem II (PSII) activity in resistant plants. Characteristics of recovery and other evidence suggest that the differential decrease in PSII efficiency in resistant leaf discs is caused by photoinhibitory damage. We propose that the differential reduction in photon yield and photosynthesis often observed in resistant plants is the result of increased sensitivity to photoinhibition.     

High production of D-tagatose by the addition of boric acid

An L-arabinose isomerase mutant enzyme from Geobacillus thermodenitrificans was used to catalyze the isomerization of D-galactose to D-tagatose with boric acid. Maximum production of D-tagatose occurred at pH 8.5-9.0, 60 degrees C, and 0.4 molar ratio of boric acid to D-galactose, and the production increased with increasing enzyme concentration. Under the optimum conditions, the enzyme (10.8 units/mL) converted 300 g/L D-galactose to 230 g/L D-tagatose for 20 h with a yield of 77% (w/w); the production and conversion yield with boric acid were 1.5-fold and 24% higher than without boric acid, respectively. In 24 h, the enzyme produced 370 g/L D-tagatose from 500 g/L D-galactose with boric acid, corresponding to a conversion yield of 74% (w/w) and a production rate of 15.4 g/L.h. The production and yield of D-tagatose obtained in this study are unprecedented.     

高产谷胱甘肽的酵母融合菌株的选育及其培养条件的研究

通过初筛、单倍体分离、诱变及原生质体融合技术选育到一株谷胱甘肽产量明显提高的融合菌株ZJF71,其谷胱甘肽产量分别为亲株的1.59和1.42倍。并对其培养条件进行了研究,结果表明碳源、装液量和培养时间对融合菌株ZJF71生产谷胱甘肽的影响较为显著。在优化的培养条件下,发酵液中谷胱甘肽总量达到185.3mg/L,为初始培养条件下的2.8倍。经遗传稳定性分析,证明融合菌株ZJF-71是遗传稳定的。     

High forskolin production in hairy roots of Coleus forskohlii

Hairy roots of Coleus forskohlii were induced by infection with the Agrobacterium rhizogenes MAFF 03-01724 strain. Growth and forskolin production of two hairy root clones cultured in various liquid media were examined. Hairy root clone B9 grew well in woody plant liquid medium and showed a high forskolin yield (ca. 1.3 mg/ 100 ml flask) after 5 weeks of culture. The time course of growth and forskolin production of the clone B9 cultured in woody plant liquid medium was also examined. Rapid growth started at week 2 and continued until week 5. The highest forskolin yield (ca. 1.6 mg/100 ml flask) was obtained at week 5. Productivity was much higher than that previously reported. Received: 19 June 1997 / Revision received: 6 October 1997 / Accepted: 18 October 1997     

He-Ne激光对金针菇SOD高产株的诱变效应

用He-Ne激光辐照诱金针茹（Flammulina Velutipes）的原生质体、菌丝体片段,分生孢子悬液,并进行初筛、复筛及突变株遗传稳定性研究。结果表明：采用原生质体进行诱变,其正突变率,单株SOD产量提高率,产SOD遗传稳定性均高于菌系体与分生孢子。激光诱变原生质体是获得金针茹SOD高产株的有效途径。     

High Yield Isolation of Nuclei from Plant Protoplasts

Nuclei were isolated from protoplasts obtained from Parthenocissus tricuspidata Crown Gall callus tissues. The effect of various isolation procedures, detergent or ultrasonication, on yield and quality of nuclei was studied. A standard procedure, based on the use of 5 × 10^?3% Triton × 100 — 6% PVP — 20% glycerol, may be carried out in 30 min and gives 80 to 90% yield of nuclei in which RNA polymerase activity is retained.     

冬小麦高产高效栽培投资风险预测模拟

在产量形成规律及投入产出效益规律基础上,建立了冬小麦高产高效栽培投资风险预测模拟模型.并以Window XP为平台,采用VB(Visual Basic)语言编程,建立了相应的可视化模拟系统。通过模拟,生产者可以预测在当时的市场价格下小麦生产的投资风险大小,并预测生产的最大利润及小麦产量.模拟系统还可以用于决策部门对市场价格的宏观调控,如果希望增加农民收入,鼓励农民生产粮食,决策部门可以先定单位面积小麦生产利润值,通过模拟得适宜的肥粮价比,用来调控市场价格,     

发酵生产辅酶Q10高产菌株的选育

以实验室保存的类球红细菌(Rhodobacter sphaeroides)JDW61为出发菌株,考察了紫外、紫外结合氯化锂和亚硝基胍对菌株产生辅酶Q10能力的诱变效应,并结合辅酶Q10的合成途径设计了快速筛选辅酶Q10高产菌株的模型,获得一株辅酶Q10产量提高的突变株CP222,该菌株摇瓶发酵的辅酶Q10产量为276.14mg·L-1,较出发菌株提高了190%,并且遗传性能稳定。     

激光810大豆高产稳产性分析

笔者运用激光技术选育出了激光810大豆,亩产400kg以上,并分析了激光810高产稳产性的原因。     

作物太空育种机理初报

论文从辐照原理出发,提出如何模仿太空环境来进行地面辐射,以大幅度提高农作物产量。