Expression of α-1,6-dextranase from Penicillium minioluteum in P.pastoris

α-1,6-葡聚糖酶是专一作用于α-1,6糖苷键产生小分子葡聚糖的一类水解酶,广泛的运用于制糖工业和啤酒工业中。采用PCr法扩增朱黄青霉(PEnICIllIuM MInIOluTEuM)C12114的α-1,6-葡聚糖酶基因,将其插入毕赤酵母表达载体PPIC9k。经SACI酶线性化电击转入毕赤酵母基因组,构建重组酵母gS115/PPIC9k-dEX。对构建成功的转化子进行1.5%的甲醇诱导表达,在30℃条件下培养7d时酶活达到最大值,为88.35u/Ml。α-1,6-dextranase,which can hydrolyze dextran specifically by cutting off the α-1,6-glycosidic bond to release shorter saccharides,was widely used in many fields such as sugar industry and beer industry.The gene of α-1,6-dextranase(dex)was amplified through PCR by using Penicillium minioluteum C12114 genomic DNA as template.The amplified gene was cloned into vector pPIC9K and the recombinant plasmid pPIC9K-dex was linearzed with Sac I,then transformed into P.pastoris GS115 by electroporation.The positive transformant was induced to express the enzyme with 1.5% methanol for 7 days under the 30℃,and the activity of the enzyme could reach 88.35U/mL.广东省科技计划项

Effects of Different Concentrations of Alcohol On Spatial Learning and Memory Ability and Hippocampal GFAP/NEUN in Mice

目的 探究长期饮酒对小鼠行为学能力以及空间学习记忆能力的影响。方法 雄性KM小鼠45只,随机分成对照组（Con）,低剂量组（Low）和高剂量组（High）。分别每天对照组0.10 ml/10 g自来水,低剂量组0.05 ml/10 g的56度红星二锅头,高剂量组0.10 ml/10 g的56度红星二锅头进行灌胃。连续灌胃13 d后进行衣架实验测行为学能力,最后取海马做免疫荧光染色观察海马神经元和星形胶质细胞。结果衣架实验得分,自主活动数值总体显示Low组高于其他两组,而且与Con组差异显著;免疫荧光结果显示无论是CA3区,还是DG区,海马的星形胶质细胞含量与神经元细胞含量比值上Con,Low,High三组依次升高,而且Con,High之间对比,P〈0.05,差异有统计学意义。结论 长期大量饮酒会损伤学习记忆能力,但适量饮酒可以促进机体兴奋性和活动度。Objective To investigated the effects of long-term alcohol drinking on the ability of learning and memory in mice. Methods 45 male KM mice were randomly divided into control group （Con）, low dose group （Low） and high dose group （High）. The control group were daily 0.10 ml/10 g tap water, low dose group 0.05 ml/10 g, 56 degree star erguotou, high dose group 0.10 ml/10 g, 56 degree star Erguotou by intragastric administration. After 13 days of continuous feeding, the experiment was conducted to test the behavior of the horse＇s tail, and the hippocampus was observed by immunofluorescence staining. Results The hanger score, numerical display Low overall locomotor activity was higher than the other two groups, and group Con; immunofluorescence results showed that both the CA3 region or DG region, astrocytes and neurons of hippocampus content ratio on Con, Low, High three group were significantly increased, and Con, High had significant difference, Conclusion A large number of long-term drinking will damage the ability of learning and memory, but moderate alcohol consumption can promote the body excitability and activity

Screening of high daptomycin-producing strains by combined antibiotics resistance screening method

作者简介：张智翔，男，生于1985年，在读硕士研究生，主要从事微生物发酵，E-mail: [email protected] *通讯作者，E-mail: [email protected][中文文摘]目的利用组合抗性筛选法选育达托霉素高产菌株。方法以玫瑰孢链霉菌(Streptomyces roseosporus ATCC 11379)为出发菌株,通过在不同浓度梯度的达托霉素和链霉素复合抗性平板上进行抗性筛选。结果筛选到一株高产达托霉素的突变株D1000-S3-2,经摇瓶发酵验证达托霉素发酵单位可达59mg/L,比出发菌株提高了63.8%。结论实验证明组合抗性筛选是一种简单高效筛选方法。[英文文摘]Combined antibiotics resistance screening method was applied to screen daptomycin high-producing strain. Methods Based on the biosynthetic pathway and metabolization mechanism of daptoomycin, combined antibiotics resistance screening method was applied to screen daptomycin high-producing strain from original strain of Streptomyces roseosporus ATCC 11379. Results A mutant strain D1000-S3-2 was obtained. The yield of daptomycin was 59 mg/L in fl ask by the mutant strain, which increased 63.8%, compared to that of the parental strain. Conclusion It was demonstrated that the method provides a fast and effective way of screening S. roseosporus.基金项目：国家自然科学基金(No. 31071488

The Influencing Factors of the Performance of China’s Open-end Stock Funds: An Empirical Study Based on Panel Data Analysis

使用面板数据分析方法对我国开放式股票型基金的业绩影响因素进行实证研究,研究表明,基金的绝对业绩和相对业绩的影响因素比较相似。基金业绩与其股票交易量、资金利用效率、份额增长率、管理费率及股市整体走势呈正相关关系,与机构投资者比例呈负相关关系,与基金规模呈倒u型关系,与基金风险无显著关系。This paper presents the result of the authors' empirical study,conducted by means of panel data analysis,of the influencing factors of the performance of China's open-end stock funds.The authors,through the study,find that the influencing factors of absolute performance are similar to those of relative performance.The paper points out that there is positive correlation between fund performance and the stock exchange volume,efficiency of fund utilization,share growth rate,management fee rate,and the whole trend of the stock market,that there is negative correlation between fund performance and institutional investor proportion,that there is a reversed U relationship between fund performance and fund scale,and that there is no remarkable relation between fund performance and fund risk

激发跃迁速率对热力学非平衡氮气紫外辐射的影响

基于氮气的碰撞-辐射(CR)模型,计算了速度为6.2km/s、初始压力为133Pa的高超声速流动激波中N_2和N_2~+分子电子能级的分布情况,分析了不同激发跃迁速率模型对电子能级分布及辐射光谱模拟的影响。针对流动中热力学非平衡区域和平衡区域,在300～440nm的辐射光谱开展了逐线法的数值模拟,并与激波管实验测量光谱进行了对比。结果表明,目前的激发跃迁速率均存在偏差,综合Park模型的爱因斯坦系数和Johnston模型的碰撞激发速率可以得到与实验结果最为接近的辐射光谱

Screening of Sodium Caprate Resistance Strains for Daptomycin Production and Medium Optimization by Response Surface Methodology

为提高玫瑰孢链霉菌(STrEPTOMyCES rOSEOSPOruS)nrrl 11379产达托霉素的能力,在实验室已有研究基础上对生产菌株进行癸酸钠抗性筛选,得到癸酸钠抗性株d1000-S3-2-P2000,经验证其能够耐受高癸酸钠浓度.此外,使用因子筛选和响应面设计对发酵培养基进行氨基酸、维生素、微量元素种类的筛选和优化,最终确定培养基组成为(g/l):酵母提取物11,(nH4)2fE(SO4)2.6H2O 0.86,葡萄糖10.7,糊精72,糖蜜7.2,组氨酸1.7,天冬氨酸1.3,l-天冬酰胺0.74,硫辛酸0.007 92,znSO4.7H2O 0.55.利用此培养基进行摇瓶和发酵罐分批发酵培养得到达托霉素产量分别为42.38和411Mg/l,分别是优化前的2.52倍和1.46倍.In order to improve the production of daptomycin by Streptomyces roseosporus NRRL 11379,sodium caprate resistance screening method was applied to obtain high sodium caprate resistance strains based on original research.A mutant strain D1000-S3-2-P2000 was achieved and had been proved to be with tolerance in high sodium caprate concentraion.Besides,amino acids,trace elements and vitamins of the medium were screened and further optimized by response surface methodology(RSM).The compositions of the optimized medium were as follows(g/L):yeast extract 11,(NH4)2Fe(SO4)2·6H2O 0.86,glucose 10.7,dextrin 72,molasses 7.2,histidine 1.7,aspartic acid 1.3,L-asparagine 0.74,lipoic acid 0.007 92,ZnSO4·7H2O 0.55.The daptomycin production of 42.38 mg/L(flask) and 411 mg/L(2.5 L-batch) were achieved,which were 2.52 and 1.46-fold of those using original conditions.福建省自然科学基金项目(2011J01058); 福建省产业技术开发项目(闽发改高技[2010]299号); 中央高校基本科研业务费专项(2011121017