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1.
豆凝乳酶产生菌的筛选及诱变育种   总被引:16,自引:0,他引:16  
从104份土样中分离到一株产豆凝乳酶的芽孢杆菌(Bacillus sp.),酶活力0.3u/ml。经UV-DES诱变及培养基调整后,酶活可达1.6u/ml以上,其最适产酶培养基组成:麦麸2.5%,(NH4)2SO4 0.5%(NH4)2HPO4 0.5%,CaCl2 0.05%。  相似文献   

2.
本文报道适用于筛选丝状真菌产生β-葡聚糖酶的平板初筛法。即:β-葡聚糖─刚果红营养平板法(GCN平板法).运用此法从分离源中初筛到产酶菌黑曲霉(Aspergillusniger)A21,经UV和NTG多次诱变,获得产酶能力高于亲株1.46倍变异株A2148.在初始pH6.8、温度29℃和以大麦为主碳源培养基中,变株A2148经86h培养产生β-葡聚糖酶[EC,3.2.1.73]128u/ml,并伴有少量糖化酶、中性蛋白酶及α-淀粉酶的产生。实验室规模提取实验表明:发酵液过滤除菌后,经硫胺、丙酮沉淀可得2106u/g左右的粉状酶制剂,酶提取总收率达60%。  相似文献   

3.
研究Banach空间中椭圆变分不等式的扰动问题,得到了扰动问题存在唯一解的一个充分条件;并用它处理了一类半线性微分积分方程的边值问题.设V是可分自反Banach空间,V′是V的对偶空间,K是V中非空闭凸子集,则有定理1设T:V→V′,A:K→V′,且满足(i)T是有界线性算子,存在常数α>0,使得(Tv,v)≥αv2,v∈V;(i)A是伪单调算子,存在常数λ>0,使得(Au-Av,u-v)≤λu-v2,u,v∈K;(ii)α>λ.则存在唯一的u∈K,使得(Tu,v-u)+(Au,v-u)≥(f,v-u),u∈K  相似文献   

4.
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   

5.
本文报道适用于筛选丝状真菌产生β-葡聚糖酶的平板初筛法。即:β葡聚糖-刚果红营养平板法(GCN)平板法。运用此法从分离源中初筛到产酶菌黑曲霉(Aspergillus niger)A21,经UV和NTG多次诱变,获得产酶能力高于亲株1.46倍变异株A2148。在初始PH6.8、温度29℃和以碱产为主碳源培养基中,变株A2148经86h培养产生β-葡聚糖酶128u/ml,并伴有少量糖化酶、中性蛋白酶及  相似文献   

6.
报道少孢酵母用UV处理,经摇瓶筛选获得诱变株M413,其产量为7.2%,发酵力672mL,均超过出发菌株水平.经优选最佳培养基配方为(100mL):糖蜜28Bx、玉米浆3.7g,过磷酸钙0.28g、硫酸铵0.10g、硫酸镁0.04g,用此培养基的酵母规格符合QB929-84面包标准.  相似文献   

7.
通过计算α-LiIO3:Ni^2+晶体零场分裂D和g因子,研究了掺杂Ni^2+的α-LiIO3晶体中Ni^2+_Vu三角中心的局域结构,估算出Ni2+离子应向Li^+空位位移,以及Vu附近的氧离子应位移△x≈0.149A。  相似文献   

8.
催化动力学光度法测定痕量铜(Ⅱ)   总被引:1,自引:0,他引:1       下载免费PDF全文
在V(V) - Mn( Ⅱ) - 二安替比林基( 间一羟基) 苯基甲烷(DAm HM) 显色体系中, Cu ( Ⅱ)具有阻化作用. Cu( Ⅱ) 量在2-0 ~8-0μg/25mL 范围内具有良好的线性关系, 由此建立了测定痕量Cu( Ⅱ) 的催化动力学光度法.  相似文献   

9.
紫红曲的原生质体紫外线诱变育种   总被引:5,自引:0,他引:5       下载免费PDF全文
对紫红曲原生质体进行不同时间紫外线照射诱变,实验表明,采用紫外线(UV)照射60s,可获得高产突变株,该突变株M1-1的红曲色素产量是亲本株的红曲色素产量的2.27倍,说明原生质体进行诱变处理是简单易行的较好方法。  相似文献   

10.
对担子菌LMPQ39菌丝原生质体进行了紫外光──LiCl复合处理后,得到突变株U39,再将其分别用60Co、HNO2两种方法处理,各获得突变株UCo39和UN39,它们的CMC酶活由原来LMPQ39的0.31u分别提高到0.46u和0.576u.酯酶同功酶电泳表明,UCo39、UN39和母株LMPQ39的酶谱出现了6条共同的谱带,同时也出现差异.突变株和母株的拮抗试验呈阳性。  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.
王慧 《科技信息》2008,(10):240-240
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.  相似文献   

14.
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.  相似文献   

15.
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   

16.
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   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
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   

19.
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   

20.
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   

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