芽孢杆菌乳酸高产菌株UZ3-15的紫外线诱变选育

为了获得乳酸的高产菌株,以实验室前期筛选获得的产乳酸芽孢杆菌Z-3-1为出发菌株,通过紫外线诱变来选育乳酸高产菌株,紫外线诱变条件为30 W紫外灯,30 cm辐照距离,诱变时间为150 s.采用溶钙圈法对诱变后的菌株进行初步筛选,得到在MRS-CaCO3培养基上产生透明圈直径较大的菌株19株.通过对菌株的发酵液进行乳酸...     

铜抗性菌株的原生质体诱变选育及其吸附能力检测

将酿酒酵母(saccharomyces cerevisiae)菌株Y1单倍体化，筛选得到单倍体出发菌株SY1，通过紫外线(UV)和亚硝基胍(NTG)复合诱变，获得1株高抗性突变菌株，其Cu^2 抗性水平为8mmol／L，是出发菌株的8倍，其Cu^2 吸附量是出发菌株的4．6倍。50世代培养结果表明，其遗传稳定性在96％以上。     

一株降解淀粉填充聚乙烯放线菌的筛选以及诱变选育

目前对聚乙烯降解菌的研究主要集中在细菌和真菌中,放线菌作为聚乙烯降解菌株还鲜有报道.利用添加改良淀粉聚乙烯粉末为唯一碳源和能源的无碳源培养基,从土壤中分离筛选得到一株可以降解淀粉聚乙烯的降解菌LBX-2,通过形态学观察生理生化反应,结合16Sr DNA序列进行分类鉴定,菌株LBX-2与Streptomyces albogriseolus的亲缘关系最近,形态学观察和生理生化指标也与之相符,初步鉴定为白浅灰链霉菌.以筛选得到的降解菌LBX-2作为出发菌株,采用吖啶橙-紫外线复合诱变的方法进行诱变选育,吖啶橙最佳诱变剂量为1×10~(-2)g/m L,紫外线最佳诱变持续时间为50 s,诱变株较之原始菌株降解能力提高了41.80%,是一株具有研究和应用潜力的降解淀粉聚乙烯的菌株.     

液体发酵饲料植物乳杆菌诱变育种的研究

通过紫外线诱变植物乳杆菌选育具有良好发酵性能的液体发酵饲料专用乳酸菌.试验中采用紫外线的最佳诱变时间为120s,并用溶钙圈法对诱变后的菌株进行初步筛选,在MRS-CaCO_3培养基上得到溶钙圈直径较大的菌株79株.通过对这79株菌株的液体发酵饲料进行乳酸含量的测定,最终得到一株乳酸高产菌株UR-3,显著提高了产乳酸量(p0.05),在液体发酵饲料中,该菌株产乳酸能力较出发菌株提高了44.53%.     

好氧反硝化菌的物理诱变法育种研究

以实验室SBR反应器分离出的好氧反硝化菌(WXZ-9)为原始菌株,分别用微波和紫外线诱变.通过反硝化性能测定筛选得到的正突变体WXZ-9-8号,96 h后的TIN去除率达到67.20%,比出发菌株WXZ-9号菌提高了7.07%,NO3--N去除率在24 h达到100%;WXZ-9-8号突变体的最大亚硝基氮还原速率达到52.89 mgNO2--N.L-1.d-1,比WXZ-9号菌株高6.90mgNO2--N.L-1.d-1.结果表明:WXZ-9-8号突变体具有更好的亚硝基氮还原酶的活性,并且比出发菌株有更好的生长适应性.     

α-亚麻酸特异性脂肪酶产生菌的复合诱变研究

将前期实验中经筛选、紫外诱变获得的α-亚麻酸特异性脂肪酶产生菌为诱变出发菌,通过紫外线、硫酸乙二酯和氯化锂的物理—化学复合诱变处理,经平板筛选和摇瓶发酵及发酵液中脂肪酶活性的测定,分离出具有产生更高活力α-亚麻酸特异性脂肪酶的菌株,测试结果显示,其酶活较单一紫外诱变菌种提高了31%.     

不同诱变方法对青霉TS406Y胆固醇氧化酶活性的影响

以青霉Ts406Y(Penicillum sp.)为诱变出发菌株,评价了硫酸二乙酯(DES)、亚硝基胍(NTG)和甲基磺酸乙酯(EMS)对该菌株的诱变效应,发现在常规剂量内达到70%致死率时所需要的时间分别为23,3,90 min.根据使用方便和安全原则,进行了青霉TS406Y的DES诱变和选育,获得了胆固醇氧化酶活性提高84.5%的突变菌株D5,其胆固醇氧化酶活性达到了1 240 U/L,连续传代6次.发现D5菌株具有遗传稳定性.另外还发现,利用紫外线(UV)和EDS对单因素诱变后获得的胆固醇氧化酶高产菌株进行复合诱变.94%的突变菌株为负变菌株.     

一株拮抗猕猴桃叶枯病的美丽短芽孢杆菌NF2的He-Ne激光诱变育种

对一株拮抗猕猴桃叶枯病的美丽短芽孢杆菌NF2进行He-Ne激光诱变育种,通过测定菌株的生长曲线确定诱变时的菌龄为摇瓶培养8h,此时菌体没有产芽孢;分别设置不同的诱变强度和时间,确定最佳的诱变条件为5mW,10min,此时菌株的拮抗效果提高了20.63%;SPSS软件分析诱变后菌株拮抗能力可稳定遗传至少15代。He-Ne激光诱变是一种安全有效的微生物育种技术,低剂量激光辐射更有利于菌株诱变效果的提高。     

枯草芽孢杆菌YYW-1蛋白酶缺陷株诱变与筛选

从羽毛废弃物中筛选出一株高效降解羽毛、产角蛋白酶和蛋白酶的革兰氏阳性芽孢杆菌,经鉴定为枯草芽孢杆菌(Bacillus sublitis),命名为B.sublitisYYW-1。利用紫外线对菌株YYW-1进行诱变,筛选蛋白酶缺陷株,获得蛋白酶活性丧失的诱变株YYW-1-5,其蛋白酶活性残余22.7%,而角蛋白酶活性残余94.7%,没有明显的变化。     

嗜酸性氧化亚铁硫杆菌低温诱变试验研究

嗜酸性氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans,简称A.ferrooxidans菌)在生产实践中有着广泛的运用和发展前景,然而低温是限制其发展的一个重要因素.通过紫外线低温诱变试验探讨A.ferrooxidans菌低温诱变的可行性.结果表明:1)Fe2+浓度随时间变化的曲线呈反"S"型,A.ferrooxidans菌的活性变化符合"S"型增长曲线;2)紫外线诱变可以产生适宜低温生长的A.ferrooxidans菌种,但诱变时间30 s、60 s的效果无显著差异;3)A.ferrooxidans菌的活性是随温度的降低而减小的,诱变产生的菌种并不能逆转这一生长规律;4)3个诱变温度相比较,15℃的诱变效果最佳,诱变组的Fe2+氧化率比未诱变的空白组高了14%,这也表明了A.ferrooxidans菌紫外线低温诱变的可行性,为A.ferrooxidans菌的推广和应用提供一定的理论支持.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with