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1.
紫外诱变原生质体选育碱性蛋白酶高产菌株的研究   总被引:8,自引:1,他引:8  
以地衣状芽孢杆菌53-A6为出发菌株,考察了各种因素对原生质体形成和再生的影响,在原生质体形成和再生的最佳条件下制备原生质体,53-A6菌原生质体形成率和再生率分别达99.7%和30.9%,通过光学显微镜和电镜技术,观察了原生质体形成再生和原生质体聚集现象。  相似文献   

2.
以地衣状芽孢杆菌53-A6为出发菌株,考察了各种因素对原生质体形成和再生的影响.在原生质体形成和再生的最佳条件下制备原生质体,53-A6菌原生质体形成率和再生率分别达99.7%和30.9%。通过光学显微镜和电镜技术,观察了原生质体形成再生和原生质体聚集现象。  相似文献   

3.
本文研究了钝齿棒状杆菌(Corynebacterium crenatum AS1.542)原生质体形成和再生的条件。结果表明:菌体培养至对数生长期,用1.Oμg/ml青霉素G处理4小时,再以1000μg/ml蛋清溶菌酶在37℃下处理14小时原生质体形成率达99.0%,在含0.5M蔗糖的高渗完全基上,它的再生率为20.0~50.0%。高渗缓冲液DF比NSM和SMM更适合于原生质体的再生,高渗稳定剂0.5mol/L蔗糖优于0.5mol/LNaCl。用电镜观察了菌体和原生质体的形态结构。  相似文献   

4.
以产L-甲硫氨酸芽孢杆菌M0658为出发菌株,考察了各种因素对原生质体形成和再生的影响.在原生质体形成和再生的最佳条件下,M0658原生质体形成率和再生率分别达到96.4%和75.3%,并在光学显微镜下观察了原生质体和原菌的形态差别.  相似文献   

5.
本文研究了钝齿棒状杆菌(Corynebacterium crenatum AS1.542)原生质体形成和再生的条件。结果表明:菌体培养至对数生长期,用1.0 μg/ml青霉素G处理4小时,再以1000μg/ml蛋清溶菌酶在37℃下处理14小时原生质体形成率达99.0%,在含0.5M蔗糖的高渗完全基上,它的再生率为20.0~50.0%。高渗缓冲液DF比NSM和SMM更适合于原生质体的再生,高渗稳定剂0.5 mol/L蔗糖优于0.5 mol/L NaCl。用电镜观察了菌体和原生质体的形态结构。  相似文献   

6.
以地衣芽孢杆菌(Bacillus licheniformis)JF-20菌为出发菌株,对原生质体制备及再生的各种影响因素进行了研究,在原生质体形成及再生的最佳条件下制备原生质体。结果发现:JF-20菌的原生质体形成率及再生率分别达到以86.9%和38.4%,并通过光学显微镜技术,观察了原生质体形成及再生的有关现象。  相似文献   

7.
金针菇原生质体制备和再生条件实验   总被引:1,自引:0,他引:1  
本文采用溶壁酶(Lyuvllzyme)、蜗牛酶(Snailase)、纤维素酶(Cellulase)制备金针菇(Flammulina Velutipes)的原生质体.比较了酶的浓度、渗透压稳定剂、温度、酶解时间、菌龄等因素对原生质体形成和再生的作用.1%蜗牛酶和1.5%溶壁酶酶解金针菇菌丝获得了高产量的原生质体.无机盐(kcl,Nacl,Mgso_4)和甘露醇是制备金针菇原生质体的有效稳定剂.35℃、酶解1小时、菌龄3~4天的菌丝是制备金针菇原生质体的最佳条件.不同的再生菌丝生长速度和子实体形成的时间有很大的差异.  相似文献   

8.
6株谷氨酸产生菌以甘氨酸、青霉素和溶菌酶不同组合处理,对其原生质体形成进行了比较,在最佳条件下,原生质体形成率可达95~100%。B9-15 菌株细胞形态特殊,表面呈凹陷状,仅在含1.5~2.0%甘氨酸的高渗培养液中就能形成原生质体,在加有壁制剂的丁二酸钠高渗培养基上,所试菌株的原生质体再生率从10.5%~61.8%,差异性较大。  相似文献   

9.
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   

10.
一株耐盐性酵母的原生质体化及再生条件的优化研究   总被引:3,自引:0,他引:3  
对一株耐盐性酵母Zygosaccharomyces rouxii的原生质体化及再生条件进行了实验研究.结果表明:用0.5 mg/mL(10 unit/mL)细胞壁溶解酶zymolyase20T在1.0~1.5 mol/L山梨糖醇渗透压调节剂的浓度范围内,原生质体化率可达99%以上,再生率在2%~11%之间,而且用磷酸钾缓冲液比用Tris-HCl缓冲液再生率高.在山梨糖醇浓度1.5 mol/L,zymolyase20T浓度0.5 mg/mL,磷酸钾缓冲液0.1 mol/L(pH6.0)时,30℃、60 min,再生率达30%以上.  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.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
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   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  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.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

18.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

19.
20.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

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