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1.
以地衣芽孢杆菌(BacilusLicheniformis)53号菌为出发菌株,在原生质形成和再生的最佳条件下制备原生质体,并对原生质体进行了多次诱变处理,从大量突变株进行筛选最终获得了高产、稳定、耐热的碱性蛋白酶产生菌株53-G38-6,产酶活力由1104U/ml提高到22080U/ml.该诱变株最适产酶条件为:培养基由质量分数(w/%)为胰蛋白胨1,酵母膏0.5,玉米粉5,Na2HPO412H2O0.4,KH2PO40.03,Na2CO30.1组成,pH自然,培养温度42℃,培养时间44~48h,w/%为0.2的CaCO3可提高酶的产量.酶作用的最适条件:62℃,pH10.0,pH在9~10之间稳定  相似文献   

2.
平菇原生质体制备、再生及灭活研究   总被引:1,自引:0,他引:1  
紫孢侧耳、糙皮侧耳和佛罗里达侧耳的原生质体制备与再生的最佳条件为:用1%溶壁酶+0.5%蜗牛酶的混合酶液酶解培养3~4天的菌丝体,1.5小时后,原生质体产量均可达10 ̄(10)个/L;三种侧耳的最佳再生培养基分别为SM、MP和RP,再生率分别为0.61%、0.67%和0.76%。随着紫外线对原生质体处理时间的加长,再生率逐渐下降,当处理4min时,再生率接近零。  相似文献   

3.
酵母嗜杀质粒融合转移──Ⅰ.融合转移系统的建立   总被引:2,自引:0,他引:2  
以嗜杀酵母ERR1和啤酒生产酵母AS2420出发菌株,建立了供体菌MK2-3:K+R+Leu-ρ+(n)和受体菌AS2420-1:K-R-leu+ρ°(2n).对原生质体制备再生条件的研究结果表明两株菌的原生质体制备条件不尽相同;同一菌株原生质体形成与再生的最佳条件也不相同.有利于融合再生的原生质体制备条件是MK2-3:菌龄30h,蜗牛酶解量30g/L酶解时间30min,此时原生质体形成率为80%,而再生率达17.1%,这些条件对嗜杀活性无影响,再生菌落的嗜杀活性率达100%;而AS2420-1;菌龄24h,蜗牛酶量20g/L,酶解时间30min,原生质体形成率为81%,再生率为18.1%.对四种渗透压稳定剂的再生效果实验表明甘露醇效果最佳,氯化钾次之,考虑到廉价,氯化钾是很好的代用品,在30%PEG6000及Ca2+条件下进行原生质体融合,融合率可达8.9×10-6,对其中的融合子MAR4的遗传性状及嗜杀活性的稳定性检测,DNA含量及细胞大小测定,dsRNA质粒的提取及电泳结果分析和发酵性能测定,结果表明融合子MAR4具有较高的嗜杀活性并可以稳定遗传,有与供体菌MK2-3嗜杀质粒dsRNA相同的电泳行为,  相似文献   

4.
采用0.6%纤维素酶加0.6%蜗牛酶的混合酶由扩展青霉K40中获得大量的原生质体,并比较了菌龄、二硫苏糖醇(DTT)预处理方式、酶解时间、温度、pH、培养基成分及稳定剂等因素对原生质体的形成和再生的作用。选出制备原生质体的最适条件:0.6%纤维素酶+0.6%蜗牛酶,在0.6mol/L NaCl+0.3%CaCl2,DTT预处理0.5h,菌龄为19~20h,pH5.4,28℃酶解3~3.5h,原生质  相似文献   

5.
本研究旨在构建直接发酵淀粉生产酒精的酵母菌.选择具α-淀粉酶和葡萄糖淀粉酶活性的E.fibuligeraE11灭活的原生质体,与耐高温产酒率高的S.cerevisiaeHB-6-9单倍体进行属间原生质体融合.经35%PEG-50mmol/LCaCl2诱导,在再生选择培养基上融合率1.0~1.5×10-6,获得12个性能稳定的融合株.部分融合株生长速度、淀粉水解能力、可溶性淀粉直接发酵酒精的能力明显高于两亲株.  相似文献   

6.
马铃薯叶肉细胞感染Phytophthorainfestans(Mont.)dby的变化   总被引:1,自引:1,他引:0  
P.infestans游动孢子在0.4mol/L甘露醇溶液的Ross原生质体培养基中生长表明。在最初几小时生长的差别不大,只有经过20h之后,在培养基中游动孢了孢芽长度比对照(水中)较长。在液体培养基中共同培养原生质体和孢芽,没有发现游动孢子孢芽营养趋向。同时,P.infestans不同生理小种菌丝体潜育的原生质体的存活率,经过5-6h有显著差别。贝拉(Beella)(R1)品种原生质体在生理小种  相似文献   

7.
通过紫外诱变获得两株稳定的黑曲霉营养缺陷型Mu2(Met-)和D12(Cys-),并首次证实低温黑暗保存数小时对黑曲霉突变株具有稳定作用。系统地研究了菌龄、渗透压稳定剂、温度、酶的浓度和酶解系统等因素对黑曲霉原生质体形成的影响.采用2%溶壁酶加0.5%纤维素酶,获得了大量的原生质体。在显微镜下观察原生质体形成和再生过程, Mu2和 D12再生率分别为 54%和 33%。原生质体在正弦交变电场(1MHz,450 V/cm)作用下形成珠串,在高压电脉冲(强度 9.0 kV/cm、时程 25 μs)触发下,发生融合。  相似文献   

8.
研究了2种类型的乙烯气相聚合高活性催花剂.用SiO2,MgCl2作复合载体,负载TiCl4制得的SM型催化剂,载体中含w(Ti)为2%~3%,w(Ti3+)为35%~59%,比表面积105~120m2/g,催化活性每小时每克催化剂Ti催化得5.0~5.7kg产物PE(kg·g-1·h-1),聚合动力学曲线为衰减型.用镁粉、卤代烷、四氯化钛为主要组分制备的MG-2型催化剂,载体中w(Ti)为6%~7%,w(Ti3+)为55%~69%,比表面积70~85m2/g,催化活性1.8~2.0kg·g-1·h-1,聚合动力学曲线为平稳型.对SM型催化剂扫描电镜及图象分析得到颗粒平均粒径(d),颗粒长短轴比(dl/ds)及颗粒大小粒径比(dmax/dmin)分别为31μm,1.402,4.1,MG-2型催化剂为33μm,1.524,7.0,相应聚合产物颗粒的d,dl/ds,dmax/dmin,SM型催化剂为247μm,1.295,4.6,MG-2型催化剂为263μm,1.540,9.0.显示出SM催化剂更优良的聚合性能.  相似文献   

9.
茴香原生质体培养研究   总被引:1,自引:0,他引:1  
以茴香(FoeniculumvulgareL.)幼苗茎切段在MS附近2,4-D1mg/L、6-BA0.5mg/L的培养基上诱导产生愈伤组织,经4~5次继代后形成胚性愈伤组织。将胚性愈伤组织转至MS+NAA1mg/L+2,4-D0.5mg/L+6-BA0.25mg/L的液体培养基中培养,形成胚性细胞悬浮系。悬浮细胞在含有1.5%纤维素酶、1%果胶酶、0.5%蜗牛酶的混合酶液中酶解得到大量的原生质体,原生质体用修改的KM8P培养基中做液体浅层培养。2天后细胞发生一裂,两个月后形成0.5~1mm大小的小愈伤组织,转入含琼脂糖的固体培养基中3周后形成2~3mm的愈伤组织  相似文献   

10.
黑曲霉和假丝酵母属间原生质体融合的研究   总被引:4,自引:0,他引:4  
用PEG促融剂使经硫酸二乙酯灭活的黑曲霉(Aspergillusniger)W25原生质体与假丝酵母(Candidasp.)Y002原生质体融合,在选择性培养基上获得能利用羧甲基纤维素作唯一碳源生长的杂种酵母FACC.经遗传特性、碳源同化及DNA含量等项目分析,表明杂种菌株FACC与双亲菌株有区别,并进行酶活与SCP产量的比较.  相似文献   

11.
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.  相似文献   

12.
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。  相似文献   

13.
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.  相似文献   

14.
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-  相似文献   

15.
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-  相似文献   

16.
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  相似文献   

17.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

18.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

19.
<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  相似文献   

20.
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