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1.
用平板培养法和多管发酵法对延安大学内的自来水和几种纯净水的细菌学进行了检测。结果表明:自来水和纯净水合格。其中自来水平均细菌总数为21.5CFU/mL,大肠菌群数0MPN/100mL;雅苑校区开水房开水平均细菌总数为0CFU/mL,校本部开水房11CFU/mL,平均大肠茵群数均为0MPN/mL;纯净水中,碧源牌平均细菌总数为10CFU/mL,大肠茵群0MPN/100mL,绿缘牌平均细菌总数为13CFU/mL,大肠茵群0MPN/100mL。  相似文献   

2.
针对传统的菌落总数和大肠菌群检测方法存在耗时长、步骤繁琐、工作量大等问题,提出一种能够快速、灵敏、准确地检测多种不同样品的菌落总数和大肠菌群多道快速检测系统。通过电导电极采集的电导率变化数据和光子接收器采集的吸光度变化数据,由固化在计算机的程序来实现同时检测样品中的菌落总数和大肠菌群。实验结果表明,该检测系统灵敏度高,最低可检测出10个/m L(g)样品,菌浓度在(10~10~6)cfu/m L(g)范围内具有良好的线性关系;检测速度快,当菌浓为10cfu/m L时菌落总数所需的检测时间为13 h,大肠菌群所需时间9 h;准确性好,其检测结果与国标法基本一致,可满足各种环境、食品、药品常见样品菌落总数和大肠菌群的快速检测需求。  相似文献   

3.
宏基因组DNA的成功获取是宏基因组学技术顺利开展的关键.利用溶菌酶-SDS-蛋白酶K法(LSK法)提取活性污泥宏基因组DNA,结合单因素法与表面响应法对提取过程的4个关键步骤进行条件优化,即预处理、细胞裂解、蛋白去除及DNA沉淀过程.确定影响DNA产量的重要因素:预处理缓冲溶液与DNA沉淀剂类型、CTAB质量分数、溶菌酶浓度、37℃水浴时间及SDS质量分数.确定LSK法提取宏基因组DNA的最佳条件:TENC预处理活性污泥;1.5%CTAB;0.5mg/mL溶菌酶,37℃水浴1.4h;2%SDS,200μg/mL蛋白酶,55℃水浴2.5h;异丙醇沉淀DNA 40min.在最佳条件下,活性污泥宏基因组DNA的最大产量为每g污泥170μg.本研究可为环境样品中高质量宏基因组DNA的提取提供有价值的参考.  相似文献   

4.
本文采用FA-1型六级撞击式空气微生物采样器对上海市某区4个功能区的细菌进行了收集,并应用菌落计数器和显微镜对收集到的细菌进行平皿菌落计数以分析空气中细菌总数分布现状.细菌致病性分析采用崂应2050型空气智能中流量采样器对4个功能区的细菌进行了收集,应用环介导等温扩增技术对特定致病细菌进行检测,并对该区的细菌污染状况进行评价.细菌总数和致病细菌检测结果显示:4个监测站点微生物总量的变化范围是294~1 862CFU/m~3,低于3 000CFU/m~3,依据《大气微生物评价分级标准》评价,该区的空气始终处于清洁水平,空气质量较好;夏季空气中检出沙门氏菌和金黄色葡萄球菌的概率比秋季高.  相似文献   

5.
PMA与PCR结合的细菌活细胞检测方法   总被引:1,自引:0,他引:1  
基于PCR的分子生物技术在检测过程中不能有效区分样品中细菌的死活状态,这会导致对细菌数量的错误估计.文中用叠氮溴化丙锭(PMA)对样品基因组提取进行前处理,使PMA与样品中死细胞的DNA分子共价交联,并抑制该DNA分子的PCR扩增.结果表明:当样品中PMA质量浓度大于3μg/mL、曝光时间大于3 min时,PMA可抑制细胞膜破裂的E.coli死细胞DNA的PCR扩增;PMA质量浓度高于50μg/mL时对活细胞DNA的PCR扩增有一定影响;当浊度小于10NTU时,PMA能有效地抑制死细胞DNA的PCR扩增,而当浊度大于100NTU时,PMA失去效果.  相似文献   

6.
利用平板菌落计数法和多管发酵法检测天津海河流域水体和自来水中的细菌总数、总大肠杆菌群及粪大肠菌数,以期对天津海河流域水体微生物污染状况进行分析。结果表明,在1mL的天津自来水水样中总菌数小于1,没有检测出大肠杆菌和粪大肠菌,符合《生活饮用水卫生标准》(GB5749-2005)的规定。对海河水的检测结果为大肠杆菌平均70 000个/L,超出III类水标准,粪大肠菌平均700个/L,属于II类水标准。粪大肠菌群的存在可认为河水直接或间接的受到了比较近期的人或动物粪便污染,应引起人们的重视。  相似文献   

7.
为了得到一种高效的肠道集聚性大肠杆菌基因组脱氧核糖核酸(DNA)提取方法,比较OMEGA、天根、宝生物、全式金4种细菌基因组DNA提取试剂盒对肠道集聚性大肠杆菌基因组DNA的提取效果,并对宝生物、全式金试剂盒提取方法进行优化;测定所提取的基因组DNA的纯度及浓度,并进行基因组完整性检验及特征基因检测。结果表明,使用全式金细菌基因组DNA提取试剂盒提取肠道集聚性大肠杆菌基因组DNA时,通过增加溶菌酶孵育时长至40 min,同时蛋白酶K的用量增加1倍,基因组DNA提取浓度可提高约14.5倍。  相似文献   

8.
对文山州广南县9个具有代表性的农村饮用水源点进行细菌总数和大肠菌群的检测,初步了解云南省文山州广南县农村饮用水卫生状况。在选定的9个水源点进行水样采集,并用平板菌落计数法和多管发酵法分别对水样中细菌总数和大肠菌群进行检测。发现水样6和水样7细菌总数〈100个/mL,其余水样〉100个/mL;9个水样的大肠菌群均有检出。通过检测发现,所抽取9个饮用水水源均不符合我国饮用水卫生标准(GB5749-2006),不适宜直接饮用。  相似文献   

9.
海洋底泥环境DNA提取与纯化方法比较研究   总被引:1,自引:0,他引:1  
为了探索有效的海洋底泥宏基因组DNA提取与纯化方法,分别采用CTAB结合SDS法、CTAB结合玻璃珠法、SDS结合蛋白酶K法和SoilMasterTM试剂盒法提取海洋底泥宏基因组DNA,用柱式腐殖酸清除试剂盒法与电洗脱法纯化宏基因组DNA,并对宏基因组DNA的产量与纯度进行评价.结果表明:SDS结合蛋白酶K法提取率最高,DNA片段完整;SoilMasterTM试剂盒法与CTAB结合SDS法次之;CTAB结合玻璃珠法有严重降解;电洗脱法可以得到高纯度、大于42kb宏基因组DNA片段.因此,SDS结合蛋白酶K法和电洗脱法提取纯化海洋近海底泥宏基因组DNA优于其他方法.  相似文献   

10.
以城市污水活性污泥为材料,经分级粗滤、超滤、等密度梯度离心等方法获得高纯度噬菌体悬液,常规SDS方法提取噬菌体DNA.荧光显微镜观察和计数表明浓缩液中噬菌体的纯度和丰度都显著提高;利用透射电镜对浓缩液进行观察,噬菌体的形态呈杆状、线状等多样;基因组提取结果显示,得到的DNA样品纯度高,大小介于20~25kb之间,电泳条带清晰,整个泳道没有弥散现象;利用细菌通用引物对提取的噬菌体DNA进行16SrDNA扩增阴性,说明所得到的噬菌体纯度较高,没有细菌污染.通过实验获得一种高效快捷的从污水处理系统中纯化浓缩噬菌体并进一步获得噬菌体宏基因组DNA的方法,同时为研究环境噬菌体生态分布、多样性组成奠定基础.  相似文献   

11.
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   

12.
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   

13.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

14.
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   

15.
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  相似文献   

16.
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   

17.
18.
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.  相似文献   

19.
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).  相似文献   

20.
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.  相似文献   

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