混合载体固定化酵母酒精萃取发酵的研究

以十二烷醇为革取剂,对以海藻酸钠和聚乙烯醇混合载体固定化酒精酵母乙醇发酵进行了研究．探讨了革取剂对酵母细胞的毒性及革取剂用量、搅拌速度、基质浓度等因素与乙醇革取发酵的关系,并测定了革取过程中乙醇的分配系数．为固定化酒精酵母乙醇发酵与溶剂革取耦合新工艺的开发研究提供初步资料．     

山蛭素（haemadin）在毕赤甲醇酵母中的表达及其性质鉴定

人工合成山蛭素基因后,利用基因重组的方法将山蛭素的基因克隆到pPicZαA载体,经过线性化,电转至毕赤酵母GS115中表达。使用浓度高达1500 μg/mL的zeocin筛选得到高拷贝插入的GS115-H菌株,经过优化摇瓶表达条件表达量达到100 mg/L。摇瓶培养物经离心取上清,分别使用3 kD和10 kD的超滤膜超滤,阳离子交换层析和凝胶过滤层析等纯化步骤之后,得到纯度高于95%的目的蛋白,产出量为40 mg/L,回收率为40%。通过以chromozym TH为底物的凝血酶酰胺水解实验证实了其体外生物学活性：其抑制凝血酶常数为(2.46±0.13)×10^-13 mol/L。     

敲除MIG1同时过表达MAL62面包酵母的发酵性能

以亲本面包酵母工业菌株BY-14a为对照,研究了敲除MIG1同时过表达MAL62面包酵母重组菌BPM-M的发酵性能.实验结果表明:重组菌株BPM-M的麦芽糖酶活提高,麦芽糖利用速率较亲本菌株提高29.1%;葡萄糖阻遏减弱38.8%;无糖面团发酵力达到163.4mL/(h·g),较亲本菌株提高了50.6%.     

筛选与拟南芥绒毡层发育过程中重要的转录因子DYT1相互作用的调控蛋白因子

DYT1是拟南芥绒毡层发育过程中重要的转录因子.DYT1的缺失会导致绒毡层相关功能的缺陷.然而,DYT1并不是使绒毡层功能化的充分因素,暗示了DYT1蛋白需要和其他转录因子形成复合物才能发挥功能.利用酵母双杂交技术以DYT1蛋白为诱饵在拟南芥cDNA文库中筛选与DYT1相互作用的蛋白.通过筛选从文库中得到20个阳性克隆,通过BLAST序列比对得到8个候选基因序列,从中鉴定出6种候选基因编码可能的转录因子或者其他调控转录的蛋白因子.其中5个编码调控因子的基因都被证实在花药中表达.更进一步,发现另一个对花药发育所必需的转录因子AMS能与DYT1在酵母体内形成转录复合物.表明这2个蛋白可能形成异源复合物在花药中共同调节下游基因的表达.     

卡波氏肉瘤相关疱疹病毒ORF50结合蛋白的筛选

应用酵母双杂交系统,以包含RTA氮端530个氨基酸的片段插入载体pGBKT7作为诱铒,在人脾脏cDNA文库中,筛选得到4个阳性AD/文库质粒,并用酵母双杂交实验验证了阳性AD/文库质粒与RTA的相互作用.将阳性AD/文库质粒测序并对测序结果做BLAST分析,发现它们分别是:TLE2、RBP-Jk、ZNF-12和WHSC1.     

Thiamine-binding activity ofSaccharomyces cerevisiae plasma membrane

Summary The specific binding activity to [¹⁴C]thiamine was found to be located in the plasma membrane ofSaccharomyces cerevisiae. The activity was inhibited by several thiamine analogs and it was hardly detectable in the plasma membrane from a thiamine transport mutant ofSaccharomyces cerevisiae. Some properties of the thiamine-binding activity of yeast plasma membrane are discussed in connection with those of the thiamine transport system.     

Homologous recombination in fission yeast: Absence of crossover interference and synaptonemal complex

The study of homologous recombination in the fission yeastSchizosaccharomyces pombe has recently been extended to the cytological analysis of meiotic prophase. Unlike in most eukaryotes no tripartite SC structure is detectable, but linear elements resembling axial cores of other eukaryotes are retained. They may be indispensable for meiotic recombination and proper chromosome segregation in meiosis I. In addition fission yeast shows interesting features of chromosome organization in vegetative and meiotic cells: Centromeres and telomeres cluster and associate with the spindle pole body. The special properties of fission yeast meiosis correlate with the absence of crossover interference in meiotic recombination. These findings are discussed. In addition homologous recombination in fission yeast is reviewed briefly.This article is dedicated to Urs Leupold, the founder of fission yeast genetics.     

用固定化啤酒酵母细胞合成胞嘧啶核苷二磷酸胆碱

κ－卡拉胶－魔芋多糖复配胶包埋的啤酒酵母细胞，经冻融处理后用于合成胞嘧啶核苷二磷酸胆碱（CDP－胆碱）。结果表明：250mL摇瓶中加入50mL反应液（葡萄糖400mol/L，CMP10mmol/L，磷酸碍碱50mmol/L,K2HPO4-KH2PO4缓冲液100mmol/L，MgSO410mmol/L,pH=8.0），固定化细胞1200g/L,34℃、150r/min下，反应4h后补加400mmol/L葡萄糖，反应8h可使60％以上的CMP转化为CDP－胆碱。反应液经灭菌和添加辅酶I（NAD^ ）后，固定化细胞可连续使用4次，CDP－胆碱转化率维持在40％以上。     

硒酵母对环磷酰胺诱发骨髓细胞微核的作用

在注射环磷酰胺染毒后 ,小鼠骨髓嗜多染红细胞的微核细胞率与微核率均显著增加 ,而用富硒酵母灌胃预处理一周的小鼠出现微核率显著下降。结果表明 ,富硒酵母对环磷酰胺诱发微核的作用有显著抑制效应 ,富硒酵母对哺乳类细胞染色体断裂剂环磷酰胺的染色体损伤作用具有明显的防护作用     

The comparison of Cu（ll） adsorption capability of baker＇s yeast,nano-titania and their composite adsorbent

The anatase nano-TiO2 powder, with crystal size between 40 and 80 nm, was prepared by the liquid phase hydrolysis of TiCI4. At the same time, the nano-TiO2 was utilized with the baker＇s yeast biomass as a composite adsorbent to adsorb the Cu ions in the artificial aqueous solution. The investigation showed that the composite adsorbent had a fine adsorption efficiency. The TiO2 in the composite adsorbent could cooperate well with baker＇s yeast to improve the adsorbing capability of Cu^2＋ under the following experimental conditions as well： a quantity of composite adsorbent of 5 g·L^-1, pH≥4.0, an adsorption time of 40 min and an initial concentration of Cu ions of 10 mg·L^-1. In addition, the results of measurements, obtained with a scanning electron microscope, an infrared spectrophotometer and a Zeta potential analyzer, revealed that the baker＇s yeast and nano-TiO2 produced the composite adsorbent through coordination and hydrogen bonds in particular, etc. The stability of the composite adsorbent and the amount of titania loaded were largely dependent on the concentration of hydrogen ion in the solution.