热预处理对细胞分裂效率的影响

以发酵酵母为研究对象，采用超声波空蚀和高压均质方法对细胞进行机械细胞分裂，研究了热预处理对微生物细胞分裂效率的作用。结果表明：酵母悬浮液的温度经热预处理从室温（22±1）℃上升到40-50℃时，达到相同程度的细胞分裂效率所需的能量降低了；当酵母悬浮液的温度经热预处理上升到50℃时，蛋白质浓度达到最大值，蛋白质发生变质的热预处理温度≥52℃。     

酵母耐高温分子机制的研究进展

耐高温是酵母在工业生产中的重要特性之一.近年来,人们对耐高温酵母的应用研究日益重视并取得较大的进展,但其耐高温分子机制尚未明确.目前的研究结果表明,酵母耐高温机制涉及代谢网络调控、信号转导途径及多基因/蛋白共同作用等方面.本文从代谢途径、基因表达、酶活特性和蛋白质相互作用等4个方面综述当前酵母耐高温分子机制的研究进展,...     

现代生物技术与作物病虫害防治

阐述了现代生物技术与作物病虫害防治的新进展,包括用抑制雌性玉米螟产卵的化学物质杀灭欧洲玉米螟、植入苍蝇抗菌基因使作物抗病虫害、不杀益虫的人工生物大分子灭虫法以及既灭虫又环保的绿色杀虫剂等。     

Recent observations on the structure and the properties of yeast NMN adenylyltransferase

Summary A homogeneous preparation of yeast NMN adenylyltransferase (EC 2.7.7.1) showed microheterogeneity, which was revealed by FPLC (Fast Protein Liquid Chromatography) ion exchange chromatography. The resolved components have been characterized with respect to electrophoretic behavior and adenine content. The results led to a hypothesis about a possible role of poly(ADP-ribosylation) in modulating the enzyme activity.     

Screening of the interacting proteins with NifA in <Emphasis Type="Italic">Azospirillum brasilense</Emphasis> Sp7 by the yeast two-hybrid system

NifA in AzospiriUum brasilense plays a key role in regulating the synthesis and activity of nitrogenase in response to ammonia and oxygen available. In this work we used the yeast two-hybrid system to identify the proteins that interact with NifA. The nifA gene was fused to the yeast two-hybrid vector pGBD-C2, and three A. brasilense Sp7 genomic libraries for use in yeast two-hybrid studies were constructed. Screening of the libraries identified four clones encoding proteins that interact with NifA. The confirmation of the interactions of each gene product of the four clones and NifA were carried out by exchanging the vectors for nifA and the four clones and by mutageneses of the four clones with shift reading frame experiments in yeast two-hybrid studies. DNA sequence analyses showed that two clones encode proteins containing PAS domains that play an important role in signal transduction. One clone has high similarity with the fhuE gene of Escherichia coli, whose gene product is involved in iron uptake and transportation, and the other clone encodes an unknown protein.     

啤酒废酵母中RNA和β-(1,3)-D-葡聚糖的综合提取

为实现RNA和β(1,3)-D-葡聚糖的综合提取,通过碱-酶提取法和优化稀碱提取条件,研究了温度、NaOH质量分数对RNA提取的影响.结果表明:温度为100℃,NaOH质量分数为4％时,提取率为7.65％,纯度为70.24％.进一步比较中性蛋白酶和碱性蛋白酶对β-(1,3)-D-葡聚糖提取的影响,发现中性蛋白酶得到的产物较多,纯度较高,实验结果为进一步的工业化生产奠定了基础.     

固定化酵母发酵法生产女贞子特色保健果酒的研究

主要对固定化酵母的条件及女贞子果酒的发酵工艺进行了研究．采用正交实验法设计优化苹果发酵时酵母的固定化条件为：海藻酸钠浓度为3％,氯化钙浓度为3％,固定化时间为6h．通过对初始糖度及女贞子加入量的单因素实验得出：当初始糖度为18％、女贞子加入量为10g／300mL时,发酵速度较快且具有良好的风味．     

利用酵母双杂交系统筛选IrrE相互作用蛋白

本研究通过酵母双杂交技术,构建了IrrE蛋白为诱饵载体,从拟南芥cDNA文库中筛选与IrrE诱饵蛋白相互作用的功能蛋白.研究结果表明,在所获得的阳性克隆中,发现了一个与拟南芥基因At1g01470所编码的蛋白有较高同源性的蛋白,即LEA14蛋白（晚期胚胎发育富集蛋白）,同源性高达98%.推测IrrE转录因子在提高植物耐盐性的过程中起了重要作用.