绿豆几丁质酶的纯化和酶学性质分析

利用亲和色谱Affi-gel和离子交换色谱SP-Toyopearl从绿豆种子中分离纯化出几丁质酶.纯化的蛋白通过SDS-聚丙烯酰胺凝胶电泳鉴定达到电泳纯,分子质量为30.8kDa.还原和非还原状态下的几丁质酶蛋白均显示单一区带,说明该几丁质酶为单倍体蛋白.通过等点聚焦法测得pI为6.3.该酶的最适pH为5.4,最适反应温度为40～50℃.     

花生几丁质酶的纯化及酶学性质研究

本课题利用亲和色谱和凝胶过滤色谱法从花生种子中分离得到了几丁质酶.经SDS-PAGE鉴定,该酶蛋白已达电泳纯,分子量约34.4 kD.在还原和非还原状态下均显示单一区带,表明其为单体蛋白.此外,通过等电聚焦法可测得该酶等电点为5.1.而酶学性质的相关研究则表明:该酶最适pH为5.4,最适反应温度为40～50℃.     

甘蔗叶几丁质酶测定条件的优化

以新台糖ROC22号甘蔗为材料,采用还原糖比色法测定几丁质酶的酶活,并对酶的反应条件进行优化.结果表明:最佳显色条件为显色剂3,5-二硝基水杨酸用量为1.89mg/ml,显色时间为10min;甘蔗叶几丁质酶的最适反应时间为1h,最适温度为60℃,最适pH值为7.0.     

南海海域几丁质降解菌的筛选及其特性研究

从南海海域水样和沉积物中分离并筛选到两株几丁质降解菌,分别为SCSS04和SCSWE13.16S rDNA序列分析结果表明,菌株SCSS04属于芽孢杆菌属,菌株SCSWE13属于弧菌属.两株菌几丁质酶的产生均需要几丁质的诱导,并在富营养培养基中产酶量较高.菌株SCSS04在培养第9天产酶量达到最高,所产生的几丁质酶最适反应温度为40～50℃.菌株SCSWE13属于低温酶,在培养第7天产酶量达到最高,所产生的几丁质酶最适反应温度为20～28℃.     

木霉对棉花枯萎病菌和黄萎病菌的作用机理

木霉对棉花枯萎病菌(Fumrium oxysporum f.sp.Vasinfectum)的幼菌丝具有强烈的寄生能力，对于老熟菌丝的寄生能力较弱。木霉能够产生琼脂扩散性和挥发性抑菌物质。绿色木霉LTR-2产生的挥发性抑菌物质能强烈抑制棉花枯萎病菌的菌丝生长。木霉生物防治作用的另外一种方式是与病原菌竞争营养物质，研究发现葡萄糖是竞争对象之一。木霉具有很强的β-1,3-葡聚糖酶和几丁质酶活性。培养液中添加几丁质、木霉菌或者棉花枯萎病菌菌丝干粉后培养木霉，培养液上清能够破坏枯萎病菌的菌丝尖端并导致原生质体的泄露，该现象主要与木霉的几丁质酶活性有关。木霉对棉花黄萎病菌具有相同的作用方式。     

嗜麦芽窄食单胞菌产生的几丁质酶的特性

从土壤中筛选出一株产几丁质酶的革兰氏阴性细菌,通过16S rDNA法对酶活力最高的菌株C进行鉴定,确定为嗜麦芽窄食单胞菌(S.maltophilia)菌株.通过单因素优化法和均匀设计法确定S.maltophilia产几丁质酶的最佳条件:在pH值为7.0的基础培养基中添加质量分数为1.0%的酵母膏、质量分数为0.5%的胶体几丁质,于180 r·min-1,30 ℃的摇床中培养60 h.对硫酸铵沉淀获得的粗酶进行酶学性质研究,结果表明,该几丁质酶的最适反应温度为50 ℃,最适反应pH值为7.2,在55 ℃以上的温度条件下容易失活.通过聚丙烯酰胺凝胶电泳分析,确定S.maltophilia几丁质酶的相对分子质量为6.8×103;以筛选的S.maltophilia菌株的总DNA为模板,利用聚合酶链式反应(PCR)扩增出几丁质酶DNA测序;应用生物信息学手段推导S.maltophilia几丁质酶为分泌型蛋白酶,预测其等电点pI值为5.42,相对分子质量为6.8×103(与实验纯化的酶蛋白电泳结果一致).预测该酶氨基酸序列具有信号肽区(氨基酸残基1～41)、Ⅲ型几丁质结合区(残基47～92)、多囊肾病域(107～194)、类纤维连接蛋白Ⅲ型区(Fn3,201～278)和18家族糖基水解域等5个结构功能区,5个区域被富含Ala,Gly,Pro,Ser和Thr的短序列连接起来;在第400～500个氨基酸残基间有一个螺旋结构.     

黑豆中抗真菌蛋白的纯化及活性鉴定

利用硫酸铵分级沉降、亲和色谱Affi-gel和离子交换色谱SP-Toyopearl从黑豆种子中分离出一种抗菌蛋白,SDS-聚丙烯酰胺凝胶电泳鉴定达到电泳纯.利用SDS-聚丙烯酰胺凝胶电泳标准蛋白迁移率与分子量对数的关系,计算出该抗菌蛋白的分子量为93.3 kDa,还原和非还原状态下均显示单一区带,说明该抗真菌蛋白为单倍体蛋白.抑菌试验结果表明,此纯化的蛋白对植物致病菌瓜果腐霉病菌、棉花枯萎病菌、苹果轮纹病菌、葡萄灰霉病菌和菜豆根腐病菌等5种真菌的生长具有不同的抑制作用.     

枯草芽孢杆菌2-3-2的抗线虫作用和产酶条件与酶特性

为了研究枯草芽孢杆菌2-3-2抗线虫作用与几丁质酶活的关系,对几丁质酶的产酶条件进行优化并探讨酶的特性,通过盆栽试验测定了抗线虫效果,用DNS定糖法测定了几丁质酶活力.实验结果表明:枯草芽孢杆菌2-3-2对南方根结线虫防治效果显著,其抗线虫作用与几丁质酶活性呈正相关.几丁质酶产酶培养基组成为(g/L):胶体几丁质65,酵母膏1,葡萄糖5,KH2PO40.7,K2HPO40.5,MgSO4·7H2O 0.5,FeSO40.01,NaCl 0.5,微量盐1mL/L;起始pH 7.0,温度为30℃、培养时间为72h.与优化前相比,酶活性提高了1.59倍,达到35.17×10-10 mol/s.枯草芽孢杆菌2-3-2几丁质酶最适反应温度为40℃,最适pH为7.0;温度高于50℃及碱性条件下酶活力下降.     

明胶—戊二醛固定化双酶体系的研究

采用明胶包埋、戊二醛交联相结合的方法制备固定化葡萄糖淀粉酶—葡萄糖异构酶双酶体系.该酶制备的最适条件是温度50℃pH值6.5.该酶反应的最适温度为50℃,最适pH为5.4,最适底物浓度为15％,热稳定性在50℃以下.     

蜂房芽孢杆菌B－91几丁质酶的合成条件

从厦门地区牡养殖场分离筛选到一株产几丁质酶活力较高的蜂房芽孢杆菌（Ｂａｃｉｌ－ｌｕｓａｌｖｅｉ）Ｂ－９１，研究了该菌几丁质酶的合成条件。结果表明：该菌在以几丁质为碳氮源的培养基中生长，能合成多量的几丁质酶。酶的合成受各种几丁质诱导。在产酶培养基中添加不同的有机或无机氮源，均能促进酶的合成，而葡萄糖、麦芽糖、蔗糖和乳糖对酶合成有阻遏作用。该菌几丁质酶合成的最适培养基初始ｐＨ为６．８，最适温度为２８℃。在２５０ｍｌ三角瓶装５０ｍｌ培养基，接种量为２％，振荡培养６０ｈ时，培养液中几丁质酶活力可达２２１２ｕ／ｍＬ．     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

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.     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

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。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

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     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.