低高径比喷射环流生化反应器流体力学和发酵性能的研究

对高径比s≤2．5喷射环流生化反应器的流体力学和传质特性进行了系统的研究,选出反应器的最佳结构,关联出氧的体积传递系数(k_La)表达式。在此基础上,进行了谷氨酸发酵试验,摸索出用该设备进行各氨酸发酵的最佳工艺条件,使5批一次性投糖发酵的糖酸转化率达到50％以上。     

磷脂模型膜的时间分辨纳秒荧光光谱的研究

叙述了用时间分辨率纳秒荧光技术研究大豆磷脂或合成磷脂模型膜（脂质体）的物理状态变化与荧光寿命以及时间分辨各向异性测量参数变化相关性的实验结果。用荧光探剂ＭＣ５４０标记模型膜的结果表明,荧光寿命（τ）的变化与脂质／探剂比例、磷脂组成、磷脂的极性头部、脂肪酸酰链长度等有关。用ＤＰＨ（１,６－ｄｉｐｈｅｎｙｌ－１,３,５－ｈｅｘａｔｒｉｅｎｅ）标记磷脂模型膜的时间分辨各向异性分析结果表明,序参数（Ｓ）、     

Territrems, tremorgenic mycotoxins of Aspergillus terreus.

The tremorgenic mycotoxins isolated from Aspergillus terreus were given the trivial names territrem A and B instead of their previous designations of C1 and C2 respectively. High-resolution mass spectral data suggested the molecular formula of territrem A to be C28H30O9 and that of territrem B,C29H34O9. They were partially characterized by ultraviolet, infrared, proton magnetic resonance, and mass spectroscopy. The spectroscopic evidence indicated that their chemical structures were very similar. The procedures of purification were also revised for the complete separation of these two chemically related compounds.     

Purification of chicken brain choline acetyltransferase

Chicken brain choline acetyltransferase was purified to homogeneity using ammonium sulfate fractionation, followed by chromatography on DEAE-Sephadex (A-25), hydroxyapatite, Sephadex G-150, immunoabsorption and Sepharose-CoA columns. A purification of 3500-fold was achieved and the final preparation had a specific activity of 2:32 μmol acetylcholine formed per minute per milligram protein. The purified chicken choline acetyltransferase migrated as a single band on polyacrylamide gel electrophoresis in the presence and absence of sodium deodecyl sulfate. The native enzyme, with a molecular weight of 67,000 daltons, consists of two subunits of identical molecular weight. Chicken choline acetyltransferase has a sharp pH optimum of 7.4. It is activated by sodium chloride and potassium chloride but inhibited by cupric ion and N-ethylmaleimide.     

猕猴桃品种‘金桃’采收指标与果实软熟品质相关性研究

分别对河南省27个果园的中华猕猴桃（Actinidia chinensis Planch.）品种‘金桃’果实的5项采收生理指标及果实软熟时的8项品质性状进行测定,采用主成分分析法对果实软熟时的品质指标进行综合评分,并对果实的采收生理指标、果实软熟品质指标及综合分值间进行相关性分析。结果显示,采收时的生理指标（干物质、色度角、硬度和可溶性固形物）均与果实软熟品质综合分值间呈极显著相关,其中干物质相关系数最高,为0.437。干物质与体现果实软熟品质的关键指标（可溶性固形物、总糖和糖酸比）均呈极显著性相关。研究结果表明‘金桃’果实采收时,干物质含量是果实软熟时品质的重要评价指标,而可溶性固形物和色度角是评判采收期的辅助指标。     

两株粗糙型沙门氏菌对小鼠抗异源G~-杆菌攻击的免疫保护研究

本文对引自日本的一株粗糙化学型变异株明尼苏达沙门氏菌Re595(J)和引自美国的一株Re595(A)对小鼠异源性G~-杆菌主动和被动保护作用进行了比较。结果表明,两株菌对异源G~-杆菌的大肠杆菌和变形杆菌攻击均有良好的保护作用,但Re595(J)对抗肺炎克雷伯氏杆菌攻击的保护作用明显优于Re595(A),而Re595(A)抗绿脓杆菌攻击的保护作用则明显优于Ke595(J)。表明两株Re595的免疫原存在着差异。     

菌种与品种最佳组合的选育及增产效果

本文通过多年多点的田间接种试验,分析了大豆根瘤菌C_(33)(系VSDA_(110)的突变株)的增产效应.在合丰25号大豆接种C_(33)取得明显的增产效果,两年平均比CK增产28.55%,比61A76增产24.5%;C_(33)接种在其他品种以及在不同类型和肥力的土壤上增产效果也均高于CK和61A76,说明大豆根瘤菌C_(33)比当前生产上应用的61A76更具有广谱性和高效性.     

The yeast GLC7 gene required for glycogen accumulation encodes a type 1 protein phosphatase.

The glc7 mutant of the yeast Saccharomyces cerevisiae does not accumulate glycogen due to a defect in glycogen synthase activation (Peng, Z., Trumbly, R. J., and Reimann, E.M. (1990) J. Biol. Chem. 265, 13871-13877) whereas wild-type strains accumulate glycogen as the cell cultures approach stationary phase. We isolated the GLC7 gene by complementation of the defect in glycogen accumulation and found that the GLC7 gene is the same as the DIS2S1 gene (Ohkura, H., Kinoshita, N., Miyatani, S., Toda, T., and Yanagida, M. (1989) Cell 57, 997-1007). The protein product predicted by the GLC7 DNA sequence has a sequence that is 81% identical with rabbit protein phosphatase 1 catalytic subunit. Protein phosphatase 1 activity was greatly diminished in extracts from glc7 mutant cells. Two forms of protein phosphatase 1 were identified after chromatography of extracts on DEAE-cellulose. Both forms were diminished in the glc7 mutant and were partly restored by transformation with a plasmid carrying the GLC7 gene. Southern blots indicate the presence of a single copy of GLC7 in S. cerevisiae, and gene disruption experiments showed that the GLC7 gene is essential for cell viability. The GLC7 mRNA was identified as a 1.4-kilobase RNA that increases 4-fold at the end of exponential growth in wild-type cells, suggesting that activation of glycogen synthase is mediated by increased expression of protein phosphatase 1 as cells reach stationary phase.     

Fulvic acid disturbs processing of procollagen II in articular cartilage of embryonic chicken and may also cause Kashin-Beck disease.

Kashin-Beck disease is an endemic osteoarthropathy in China which may lead to skeletal deformation and dwarfism. We have analysed articular cartilage from two patients and found an accumulation of the precursor molecule, pro-pN-collagen II (pN, peptide attached at the amino-terminus) which was not present in extracts of control fetal cartilage. In addition, collagen II isolated from the same tissue by limited pepsin digestion had a decreased electrophoretic mobility, increased proline hydroxylation and decreased thermal stability. Previously, a genetic defect in pro-pN-collagen-I processing has been described in calf and sheep (dermatosparaxis) and man (Ehlers-Danlos, type VII) which caused an extreme fragility of the skin [Lenaers, A., Ansay, M., Nusgens, B.V. & Lapière, C.M. (1971) Eur. J. Biochem. 23, 533-541; Helle, O. & Nes, N.J. (1972) Acta Vet. Scand. 13, 443-445; Lichtenstein, J.R., Martin, G.R., Kohn, L.D., Byers, P.H. & McKusick, V.A. (1973) Science 182, 298-300]. Accordingly, one may assume that the impaired conversion of pro-pN-collagen II to collagen II and the structural alteration of collagen II, presumably caused by fulvic acid and other environmental factors, play an important role in the pathogenesis of Kashin-Beck disease.