解淀粉芽孢杆菌GSBa-1产凝乳酶培养基组成的优化

从甜酒曲中分离筛选得到1株解淀粉芽孢杆菌菌株GSBa-1,为了提高该菌株液态发酵产凝乳酶的能力,采用单因素实验和响应面法优化其产酶培养基组成。通过单因素实验分析了碳源、氮源、金属盐、磷源对菌株GSBa-1产凝乳酶的影响,并采用响应面法对产酶培养基中麦芽糖、蛋白胨和酵母浸粉含量3个主要因素的优化组合进行了定量研究,确定解淀粉芽孢杆菌GSBa-1产凝乳酶的优化培养基组成为:麦芽糖1.93g/L、蛋白胨10.89g/L、酵母浸粉2.15g/L。在此优化培养基培养条件下,该菌株产凝乳酶活力可达(562.57±7.67)Su/mL,接近理论预测值537.10Su/mL,且平均误差为4.53%。优化后解淀粉芽孢杆菌GSBa-1产凝乳酶活力比基础培养基提高了1.88倍。     

用于β-半乳糖苷酶高效发酵制备的廉价工业培养基配方开发

以乳清粉为主要成分开发了一套高产β-半乳糖苷酶且廉价的工业培养基配方.首先,考察了乳清粉替代原培养基中碳源(乳糖)和部分氮源的可行性,优化了乳清粉最佳浓度和氮源(酵母膏、蛋白胨)的最佳组合,筛选了利于β-半乳糖苷酶分泌合成的无机盐种类,获得了一套较理想的工业培养基配方:乳清粉60 g/L,酵母膏9 g/L,蛋白胨3 g/L, MnCl₂ 0.03 g/L, ZnCl₂ 0.058 g/L, pH 8.0,应用于乳酸克鲁维酵母发酵制备β-半乳糖苷酶,酶活达到33.4 U/mL(摇瓶培养)和77.47 U/mL(发酵罐培养),单位酶活力达到13.74 U/mg生物量,显著优于传统发酵培养基;且乳清粉廉价易得,特别适合作为工业培养基主成分应用于β-半乳糖苷酶的规模制备.     

茂原链霉菌产谷氨酰胺转氨酶发酵培养基优化

文章考察了不同培养基成分对茂原链霉菌产谷氨酰胺转氨酶的影响,以酶活和生物量为测定指标,采用单因素试验和正交试验确定发酵培养基最适成分及其质量浓度,以期为未来菌株扩大培养和发酵中试化提供参考。试验结果表明,优化后的培养基为:葡萄糖40g/L,蛋白胨40g/L,硝酸铵1g/L,酵母膏2g/L,硫酸镁2g/L,磷酸氢二钾2g/L。该条件下酶活可达(1.30±0.07)U/mL,生物量为(9.69±0.23)g/L。     

产纤维素酶地衣芽孢杆菌B.LY02摇瓶发酵条件优化

为了提高产纤维素酶地衣芽孢杆菌(Bacillus licheniformis LY02,B.LY02)的产酶能力,采用单因素试验对该菌株产酶的摇瓶发酵条件进行了优化。优化结果显示:菌株B.LY02发酵培养基的最适碳源为麦芽糖,氮源为酵母膏,初始pH值为5.0,培养温度为37℃,培养时间为30 h,装液量为60 mL(250 m L三角瓶),接种量(体积分数)为2%,摇床转速180~200 r/min。通过优化发酵条件,菌株B.LY02的产酶活性达到了0.683 5 U/mL,比优化前提高了约27.73%。     

海洋弧菌NTi产琼胶酶的发酵条件优化

以琼胶酶活力为主要指标,采用单因素与响应面相结合的方法,对降解琼胶的海洋弧菌NTi(Vibrio natriegens NTi)发酵产琼胶酶的摇瓶发酵培养基和发酵条件进行优化。结果表明,α-乳糖对菌株产酶具有较强的抑制作用,NH+4不利于菌株生长和产酶。培养基分别以3. 3 g/L琼脂、6. 33 g/L酵母膏为唯一碳源及氮源,添加20 g/L的Na Cl,发酵海洋弧菌V. natriegens NTi产琼胶酶的效果最佳。发酵过程中的p H值、接种量、装液量、温度、发酵时间最优值分别为6. 5、2%、32 m L、27℃和24 h。优化后,该菌产琼胶酶活力达到2. 81 U/m L,比优化前增加了230%。     

β-葡萄糖苷酶高产菌株的筛选及产酶条件优化

利用栀子苷培养基快速筛选β-葡萄糖苷酶产生菌,其中草酸青霉产酶水平较高.通过单因素实验、均匀设计及回归分析优化了发酵培养基配比和摇瓶产酶最佳条件:麸皮4%,牛肉膏0.2%,NaCl 0.1%,CuSO40.08%,EDTA 0.2%,KH2PO4 0.2%,初始pH 7.0,装液量20 mL/250 mL,温度30℃.发酵液上清中的酶活由最初的16.80 U/mL提高到52.18 U/mL.     

产原果胶酶菌株X4的鉴定及其培养基的优化

采用分子生物学的方法对前期实验中获得的一株产原果胶酶菌株X4进行了鉴定. 为了提高菌株X4所产的原果胶酶量, 采用响应面法优化了菌株X4的培养基组分. 结果显示, 菌株X4为Bacillus polyfermenticus, 其主要生长影响因子为淀粉、酵母提取物、胰蛋白胨. 在本实验条件下获得的最优培养基配方为淀粉3.45 g/L, 酵母提取物3.29 g/L, 胰蛋白胨5.68 g/L, 所产原果胶酶的酶活最高为51.35 U/mL, 是优化前的2.74倍.     

一株产普鲁兰酶细菌的分离鉴定及其发酵条件优化

从淀粉加工厂附近土壤中筛选得到一株普鲁兰酶高产菌株,编号为Z-13,其初始酶活达到5.7 U/mL.通过对此菌株的16S rDNA比对,以及生理生化鉴定,鉴定此菌株为克雷伯氏菌(Klebsiella variicola),通过发酵条件优化,确定最佳发酵产酶条件为:玉米淀粉1.5%,蛋白胨2.0%,KH2PO40.05%,MgSO4·7H2O 0.01%.装液量为70 L/250 L,培养基最初pH为6.0,发酵温度30℃,摇床转速200 r/min,发酵时间48 h,优化后菌株产普鲁兰酶的酶活高达67.8 U/mL,是优化前菌株产普鲁兰酶活性的11.89倍.     

响应面法优化苏云金芽孢杆菌产耐热蛋白酶的发酵培养优化

采用二水平Plackett-Burman实验设计对影响发酵培养基的8个成分进行显著性分析,确定最重要的3因素为葡萄糖、酵母膏和ZnSO4;应用响应面分析法对这3个因素进行3水平优化,获得它们的最优组合,得到优化后的最佳发酵培养基配方(g/L):黄豆饼粉12、酵母膏4.24、葡萄糖5.43、KH2PO42、ZnS040.39、MnSO40.42.优化后产酶水平达到6473U/mL,与响应面数学模型的预测值仅有0.49％的误差.     

洗毛用枯草芽孢杆菌产蛋白酶发酵条件优化

 用响应面法(Response Surface Methodology,RSM)对枯草芽孢杆菌（Bacillus subtilis）液体发酵产蛋白酶的发酵条件进行快速优化。首先运用逐因子试验确定Bacillus subtilis产蛋白酶的最佳碳源和氮源分别为糊精和玉米粉。在此基础上,通过Plackett-Burman设计对影响其产酶相关因素进行评估,并筛选出具有显著效应的3个因素：糊精、玉米粉和酵母膏。在用最陡爬坡试验逼近以上3个因子的最大响应区域后,采用RSM法对以上3个显著因子的最佳水平范围进行研究,通过对二次多项回归方程求解,确定其最优发酵条件为：糊精11.568g/L,玉米粉22.462g/L,酵母膏10.202g/L,NaCl 5g/L。初始pH值为7.0,37℃培养48h。最终优化后的酶活达到3281.79U/mL,比初始酶活2463.95U/mL提高了33.19%,证明RSM法优化洗毛用Bacillus subtilis产蛋白酶发酵工艺是可行的。     

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…     

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).     

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.     

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.