固定化玫瑰微球菌发酵产海藻糖合成酶系

以聚氨酯为载体固定化培养玫瑰微球菌,发酵生产海藻糖合成酶系麦芽糖苷基海藻糖合成酶MTSase和麦芽糖苷基海藻糖水解酶MTHase。考察了细胞固定化对菌体生长及产酶的影响, 对固定化细胞重复批次发酵换液条件进行了初探。固定化细胞发酵40h,酶活达到最大值,产酶周期缩短了56h,细胞干质量和酶活分别达到12g/L和52u/mL,比游离细胞发酵提高了12%和33%。重复批次发酵最佳的换液条件为发酵40h后,以40%的换液量每隔24h以等量新鲜培养基替换发酵液。在此条件下,重复发酵9批,连续230h菌体生物量及酶活无明显下降。在10L发酵罐中进行放大实验,酶活最高达到80u/mL,重复发酵7批,连续180h菌体生物量及酶活无明显下降,酶的时空产率达到56.9u/(L·h),比单批发酵提高了42.5%。     

产纤维素酶粗糙脉孢菌1602产酶条件优化

通过优化设计,确定纤维素高产菌株Neurosporacrassa1602摇瓶发酵最佳产酶条件为:培养液初始pH值为5.5,培养温度为28℃,摇瓶转速为150rpm,培养96h;300玉米芯粉、0.500麸皮酸水解液(0.6mol/L)能够促进产酶,最适宜的有机氮源为黄豆粉;最适宜的无机氮源为NH4HSO4.在最适发酵条件下,其纤维酶的活力CMCase为10.34IU/ml,FPase为0.71IU/ml.     

以豆粕为原料固态发酵产纳豆激酶工艺的优化

以食品级豆粕为唯一培养基成分,通过纳豆芽孢杆菌固态发酵产纳豆激酶的培养基的优化实验,确定优化条件为:接种量5％,装量为40g于250 mL锥形瓶,培养基含水量60％,浸泡水pH 7.5,发酵温度37℃.在培养24h后达到产酶高峰,产酶活力达到1 662 FU/g.比较了在相同的发酵条件下,以食品级豆粕为培养基比大豆为培...     

一株高温蛋白酶高产菌株产酶条件的优化

对一株高温蛋白酶高产菌株枯草芽孢杆菌BY25的发酵培养基组成与产酶条件进行了优化。正交试验结果显示培养基中各因子对产酶影响从高到低为:豆饼粉、葡萄糖、硫酸镁、麸皮、磷酸氢二钠、氯化钙。在此基础上进行培养基组成优化,将豆饼粉、麸皮混合氮源改为以豆饼粉为单一氮源进行蛋白酶发酵。单因素试验发现,在单一氮源培养条件下,培养基中各因子对产酶影响从高到低依次为:豆饼粉、葡萄糖、氯化钙、磷酸氢二钠。除微量氯化钙外,金属盐,尤其是金属硫酸盐的添加对产酶有显著抑制作用。此外,培养初始pH和培养时间对产酶有显著影响,接种量也有一定影响。通过绘制120 h产酶曲线发现,BY25产酶曲线为双峰,产酶曲线顶峰出现在发酵后72 h,优化后BY25发酵培养基各组分添加量为豆饼粉60 g/L、葡萄糖60 g/L、氯化钙 0.5 g/L、磷酸氢二钠 4 g/L,接种量为4.5%～5%,初始培养pH为8.0。优化产酶培养基和产酶条件后,发酵液酶活力可达到101.1 μmol/(min·mL)。     

产纤维素酶粗糙脉孢菌1602产酶条件优化

通过优化设计，确定纤维素高产菌株Neurospora crassa 1602摇瓶发酵最佳产酶条件为：培养液初始pH值为5、5，培养温度为28℃，摇瓶转速为150rpm，培养96h；3％玉米芯粉、0．5％麸皮酸水解液(0．6mol/L)能够促进产酶，最适宜的有机氮源为黄豆粉；最适宜的无机氮源为NH4HSO4．在最适发酵条件下，其纤维酶的活力CMCase为10．34IU／ml．FPase为0．71IU／ml．     

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%。     

黑曲霉S13液体发酵产木聚糖酶的研究

从 2 0株细菌和霉菌中筛选出一株木聚糖酶高产菌株黑曲霉 S1 3.它的最适产酶培养基为 :半纤维素 1 % ,NH4NO3 0 .3% ,微量元素液 0 .0 0 5 % ,吐温 0 .2 % ,Vogel's母液 4% ,麸皮 0 .2 5 % ,起始 p H为 6.0 .种龄 36h,接种量 5 % ,装液量 60 m L( 2 5 0 m L三角瓶 ) ,摇床转速 1 2 0 r/min,发酵温度 2 8℃ ,发酵时间 48h,液体酶活可达 40 0 .0 IU/m L.     

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%。     

赖氨酸6-氨基转移酶合成条件的优化

以一株从土壤中分离、筛选到轮枝霉菌(Verticillium sp.)2-14为起始菌株,在摇瓶发酵水平上对其产赖氨酸6-氨基转移酶的条件,包括不同碳源、氮源、磷酸盐、表面活性剂等进行了优化,并对基本无机盐离子进行了正交实验分析.结果表明,该菌株产LAT最佳液体发酵培养基为:0 2% L-赖氨酸,3% 可溶性淀粉,0 5% KH2PO4,0 1% MgSO4·7H2O.通过考察菌株生长与产酶进程发现,培养52h时酶活达到峰值1217U·L-1,与优化前相比,酶活力提高一倍.     

海洋细菌NTa发酵产琼胶酶条件的初步优化

利用选择性培养基从厦门红树林泥土样品中分离得到一株具有较高琼胶酶活力的海洋细菌NTa,通过16S rRNA分析,将该菌株归属为Stenotrophomonas sp.NTa.对该菌株发酵产琼胶酶的条件进行初步优化,结果表明:菌株NTa产琼胶酶的最佳碳源是琼脂,氮源是酵母浸膏,NaCl的质量分数为5%,在28 ℃发酵培养40 h,发酵液的酶活力达到1.98 U/mL,比优化前提高了37.35%.     

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.