外环流气升式反应器发酵生产聚β-羟基丁酸酯

目的　提高Z5 G菌株发酵生产聚β 羟基丁酸酯(PHB)产量。方法　采用改变营养配比、通气条件,研究了Z5 G菌在3L外环流气升式反应器中的最佳发酵工艺条件。结果　表明该菌株在C源N源配比为4∶1,发酵前期通气量为1L/L·min-1,后期为0 7L/L·min-1,发酵时间为36h,PHB发酵产率可提高10 7%。结论　Z5 G菌株在外环流反应器中发酵PHB比机械搅拌反应器产率高,发酵周期短,从而降低了能耗,对工业化发酵生产PHB具有实用意义。     

甜菜碱对枯草芽孢杆菌合成利巴韦林的影响

以枯草芽孢杆菌TM903为供试菌株,采用摇瓶分批补料发酵的培养方式,考察了甜菜碱添加量对枯草芽孢杆菌合成利巴韦林及其合成途径中嘌呤核苷磷酸化酶(PNPase)活力的影响.结果表明,初始培养基添加0.7g/L的甜菜碱,发酵36 h后每间隔3 h流加0.1g/L甜菜碱,可显著提高PNPase的相对酶活,并且使利巴韦林的产量达4.21 g/L,比未添加前提高了47.2%.     

利用管式反应器室内模拟连续发酵糖蜜乙醇生产工艺

 利用酿酒酵母1912菌株固定化细胞载体,通过管式反应器,以糖蜜为原料进行连续化发酵生产乙醇.通过采取与工厂糖蜜乙醇生产相同的工艺控制方法,考察糖蜜发酵液中不同细胞浓度以及培养液对细胞浓度的不同稀释率条件下管式反应器的连续化发酵情况,该管式反应器能正确反映该菌株连续化乙醇发酵规律.     

Pichia pastoris发酵表达重组人复合α干扰素

在Pichia pastoris表达系统中,研究了甘油补料周期、甲醇流加策略和诱导pH对cIFN表达的影响,优化后的发酵条件是:甘油补料周期为4 h,诱导pH为5.0,基于在线甲醇检测维持甲醇浓度不超过5 g/L。培养96 h后,最大细胞干重、cIFN的表达量和生物活性分别达到168 g/L、1.24 g/L和5.4×107U/mL。     

不同添加物对L-色氨酸补料分批发酵的影响

以谷氨酸棒杆菌TQ2223(Phe^- Tyr^- 5MT^r SG^r 5FT^r CIN^r)为供试菌株，研究了在L-色氨酸低糖流加发酵过程中分别补加(NH4)2SO4、玉米浆及L-苯丙氨酸、L-酪氨酸对发酵的影响，结果表明：在发酵中期分次添加上述物质可以使色氨酸的产酸率最高达到12．1g／L。     

纳他霉素高产菌株选育及发酵工艺优化

以纳塔尔链霉菌(Streptomyces natalensis)4.3505为出发菌株,以紫外线作为诱变方法,筛选抗乙酸钠高产纳他霉素的突变菌株,优化发酵条件,筛选诱导子及添加工艺。研究结果表明:高产突变菌株为纳塔尔链霉菌HW-2,其纳他霉素产量在发酵120 h后达到452.2 mg/L,比原始菌株提高了242.6%,该菌株遗传性能稳定。纳塔尔链霉菌HW-2生产纳他霉素最佳发酵条件:接种量为发酵液总体积的6%,250 mL三角瓶装液量为30 mL,初始pH值为7.5。乙酸钠为最佳前体物质,乙酸钠的质量分数为0.2%,添加时间为发酵后24 h。     

固定化细胞乳酸发酵动力学及工艺的研究

本文对海藻酸钙固定化德氏乳酸杆菌的间歇发酵动力学进行了探讨,并对固定化细胞高糖浓度发酵以及外循环固定化细胞反应器连续发酵工艺条件进行了研究。结果表明:固定化不改变细胞的最适生长温度和pH;底物和产物均对细胞生长有抑制作用;固定化细胞生长的饱和常数和抑制常数增大,比生长速率减小,产酸速率增加;高糖浓度发酵最适工艺条件为初糖浓度120～130g/l,发酵时间68～72h,发酵液中乳酸浓度可达100g/l;外循环固定化细胞反应器连续发酵最适工艺条件为初糖浓度50g/l,稀释速率0.048～0.09l/h,转化率达78％。     

重组胸腺素α1在大肠杆菌中的融合表达及培养条件的优化

采用三角摇瓶来摸索BL21(DE3)/pET28A-Tα1菌种表达目的蛋白的最优发酵条件,并在此基础上在Biotop CF-5L自动控制发酵罐中,利用补料分批培养技术,流加甘油,进行发酵培养;利用Western blotting进行发酵产物鉴定. 摇瓶培养最优条件:10%接种量、25 mL LB培养基、37 ℃培养, 0.02 g/mL的甘油做碳源,接种后4 h加入终浓度为0.75 mmol/L的IPTG,诱导3h后目的蛋白表达量最高. BL21(DE3)/pET28A-Tα1菌种在Biotop CF-5L自动控制发酵罐中的条件为:以10%的接种量接种到3L发酵培养基中,设定溶氧40%,pH7.0,温度37 ℃,通气量3 L/min,快速流加甘油60 g ,培养4 h后,加入终浓度为0.75 mmol/L的IPTG,诱导3 h后终止发酵. 发酵罐中获得的菌体量为36 g/L,蛋白表达率为10%左右.     

重组人角质细胞生长因子-2基因的克隆、表达及活性

从人胚肺成纤维细胞中提取总RNA,利用RT-PCR法获得人角质细胞生长因子-2(hKGF-2)cDNA,并通过PCR方法扩增,再与原核表达载体pET3c连接后转化至BL21(DE3)宿主细胞中获得表达菌株.通过流加补料方式和发酵条件的控制,进行高密度培养,并通过IPTG诱导获得可溶性表达的目的产物.结果表明:目的蛋白占...     

重组人β防御素-3表达条件的优化及其对抑菌活性的影响

探讨表达条件对重组人β防御素-3(rhβD-3)表达量和抑菌活性的影响.对重组酵母菌的摇瓶发酵条件,如pH、发酵温度、甲醇的添加量等进行优化.结果表明,适宜的表达条件为BMMY培养基pH为6.0,装液量50mL/500mL锥形瓶,28℃,290r/min培养48h,每24小时加0.5%(V/V)甲醇.优化后rhβD-3的表达量可提高到340μg/mL,抑菌活性也有所提高.     

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).     

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.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.