首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
采用灭活龟裂链霉菌原生质体与金霉素链霉菌原生质体在聚乙二醇诱导下进行原生质体种间融合,利用金霉素链霉菌对链霉素的敏感性,建立选择培养基,提高了融合子的检出率。并采用同工酶谱分析及抗生素效价测定,对融合子进行了初步鉴定  相似文献   

2.
黑暗链霉菌与卡那链霉菌原生质体融合研究   总被引:10,自引:0,他引:10       下载免费PDF全文
进行了黑暗链霉菌与卡那链霉菌原生质体融合实验 .结果表明 ,将孢子悬浮液接种于种子培养基 ,然后转移到含 0 .5 %Gly的菌丝体培养基收获的菌丝体对形成原生质体最有利 .分别采用 10mg mL、6 0min及 5mg mL、75min的溶菌酶浓度与酶解时间制备黑暗链霉菌与卡那链霉菌原生质体能达到较高的形成率和再生率 .采用单亲灭活卡那链霉菌原生质体的种间融合法 ,得到与亲株形态明显不同的杂合体菌落 ,并筛选到44株妥布霉素产率提高的菌株 ,幅度最高达到 39% .  相似文献   

3.
林肯链霉菌生长在0.5%甘氨酸的S培养基中,能较好地被溶菌酶破壁形成原生质体。原生质体能在RB培养基上再生,但不能在R_2培养基上再生,这和已报道过的其他链霉菌不同。78-11菌株的再生频率约为25.7%,S-3菌株的再生频率约为20.5%。PEG(聚乙二醇)1000对诱导融合的效果较好,重组频率最高可达10~(-2)。重组子和亲本在培养特性、孢子形态方面无特殊差异,但经C_O~(60)诱变后重组子的正变率超过亲本。  相似文献   

4.
通过金霉素链霉菌和龟裂链霉菌原生质体融合选育的融合子56-2菌株,其酯酶同工酶谱与双亲有显著差异,产抗生素抗生素及遗传稳定均优于金霉素链霉菌2^#,发酵产物四环素符合中国药典的各项指标,并具有抗噬菌体P5,P8的能力。  相似文献   

5.
通过对21株分离自云南省盐碱土样的耐盐碱链霉菌的57项分类特征的聚类分析,将它们在87%Ssm相似水平上分为7个群。根据孢子丝形态,培养特征和生理学特性的差异分别定名为紫边链霉菌(S.violaceolatus),灰肉红链霉菌(S.girseoincarnatus),黄杀菌素链霉菌(S.xanthocidicus),微白色链霉菌(S.albidus),白色链霉菌(S.albus),白长链霉菌(S.albolongns),唐德链霉菌(S.tendae),它们都能在pH10.0,4%NaCl中正常生长,为耐盐碱放线菌。  相似文献   

6.
采用棒状链霉菌种内原生质体融合技术,选育克拉维酸高产菌株.该实验选用舒巴坦钠耐受性高产菌株Streptomyces clavuligerus B71-3-10和甘油耐受性高产菌株Streptomyces clavuligerus B71-14为亲株,优化了原生质体制备条件和融合条件,最终得到遗传稳定性良好的融合子F14.该融合子的克拉维酸产量提高到650.35 mg/L,分别比亲株S.clavuligerus B71-3-10和S.clavuligerus B17-14的克拉维酸产量高36.77%和20.84%.将原生质体融合技术应用到棒状链霉菌克拉维酸高产菌株的选育中,证明了其可行性、高效性及成效显著性.  相似文献   

7.
刺孢吸水链霉菌与淡紫灰链霉菌原生质体制备条件研究   总被引:1,自引:0,他引:1  
通过对甘氨酸浓度、酶解温度、酶浓度、酶解时间等影响因素考察,及正交试验优化,确定了刺孢吸水链霉菌和淡紫灰链霉菌原生质体制备的最佳条件.实验结果表明,刺孢吸水链霉菌最佳原生质体制备条件是:甘氨酸浓度为0.5%,酶解温度28 ℃,溶菌酶浓度为3×10-3 g/mL,酶作用时间60 min;淡紫灰链霉菌:甘氨酸浓度为1.0%,酶解温度32 ℃,溶菌酶浓度4×10-3 g/mL,酶作用时间60min.有效的原生质体保存条件是:-20 ℃,在5 d内,原生质体再生率在15%以上.  相似文献   

8.
利用紫外线诱变原生质体筛选四环素高产菌株的研究   总被引:2,自引:0,他引:2  
以金色链霉菌为出发菌株,经溶菌酶作用制备原生质体,然后以紫外线对原生质体进行诱变处理,在再生培养基上再生培养,获得再生突变株,将其中的单菌落以琼脂挖块法进行初筛获得第20号菌株,其相对效价为1.284。  相似文献   

9.
3个链霉菌新种的多相分类   总被引:2,自引:1,他引:2  
在筛选产生活性物质的过程中,发现4株具有抑菌、杀虫等生物活性的链霉菌.利用形态学、生理生化、化学及分子生物学程序进行了分类鉴定,并与链霉菌属已知相关菌种进行了比较,将YIM32065^T和YIM33176定名为多形链霉菌新种(Streptomyces polyformus sp.nov.),YIM35551^T定名为抗霉链霉菌新种(Streptomyces antifungus sp.nov.),YIM30823^T定名为灰白链霉菌新种(Streptomyces griseoalbus sp.nov.).  相似文献   

10.
他克莫司产生菌原生质体制备、再生与诱变   总被引:3,自引:0,他引:3  
对筑波链霉菌的原生质体制备、再生条件进行了研究,建立了筑波链霉菌的原生质体诱变筛选体系.在此基础上,通过原生质体的紫外诱变处理,筛选得到1株高产菌株,与出发菌株相比,该菌株的平均发酶单位提高51.4%.通过原生质体的紫外诱变来筛选他克莫司高产菌株是一种行之有效的方法.  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.
何延凌 《科技信息》2008,(4):258-258
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.  相似文献   

13.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
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   

19.
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   

20.
<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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号