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1.
用双层平板法和液体培养法对蛭弧菌裂解泛耐药菌进行研究. 结果表明: 该株蛭弧菌能裂解泛耐药鲍曼不动杆菌、泛耐药铜绿假单胞菌、大肠杆菌这3株革兰氏阴性菌, 不能裂解凝结芽孢杆菌、金黄色葡萄球菌这2株革兰氏阳性细菌.以泛耐药鲍曼不动杆菌为宿主菌, 研究影响蛭弧菌生长和发挥噬菌特性的因素. 35℃是蛭弧菌发挥噬菌作用的最适温度. 蛭弧菌的数量在pH75时达到最大值. 浓度为1%的NaCl有利于蛭弧菌发挥噬菌特性. 在培养蛭弧菌时添加0005mol/L的Mg2+、0003mol/L的Ca2+可以提高蛭弧菌的裂解活性. 0001mol/L的谷氨酸钠可提升蛭弧菌的裂解能力. 氯仿会将蛭弧菌全部灭活.  相似文献   

2.
济南地区蛭弧菌(Bdellovibrio)的初步研究   总被引:1,自引:0,他引:1  
从济南地区的生活污水、湖水和土壤中分离到9株蛭弧菌。它们均为直或弯曲的杆状或弧状,大小为0.20~0.31μm×0.66~1.01μm。单根极生鞭毛。在其中2株蛭弧菌的细胞两端还发现有数根须状结构。蛭弧菌 No.1对氯仿敏感,它的增殖并不依赖于其寄主的增殖。它们的寄主范围较广,可以跨越属或科。温度对于蛭弧菌 No.1的增殖速度有显著影响。每个 E.coliK_(12)细胞约释放2个蛭弧菌 No.1细胞。  相似文献   

3.
为了优化蛭弧菌的生长条件,在前期研究确定适于蛭弧菌BD1生长的最佳pH、盐度、二价金属离子(Ca2+、Mg2+)、谷氨酸钠的浓度范围的基础上,综合考虑4个因子对蛭弧菌BD1生长的影响,利用Design Expert 6.0软件进行响应面分析,优化菌体生长条件,得到该菌株生长模型,并在模型最优值时得到各因子的水平。结果表明:BD1的最优培养条件为盐度(NaCl浓度)为2.9%,培养液pH值为7.4,Ca2+、Mg2+浓度为6.4 mmol,谷氨酸钠浓度为4.2 mmol。菌体生长过程中,盐度和二价金属离子,谷氨酸钠和二价金属离子,谷氨酸钠与盐度交互作用不显著,pH与盐度,pH与谷氨酸钠,pH与二价金属离子交互作用显著。菌体生长模型达到显著水平,可以对BD1在不同条件下的生长情况进行分析和预测。  相似文献   

4.
自生活污水中分离得到了蛭弧菌 Bd—No.2,用超声波破碎仪处理了 Bd—No.2的寄主 E.coli K_(12)和非寄主革氏负(G~+)根瘤菌1.174、革氏正(G~+)枯草芽孢杆菌及卡氏酵母菌,用它们细胞匀浆液的稀释液培养蛭弧菌 Bd—No.2,双层平板计数确证它们都能使 Bd—No.2增殖,说明可以“腐生”培养。表明某些菌体不为蛭弧菌利用是与它们细胞壁的屏障作用有关。  相似文献   

5.
淤泥容纳、滋生和释放病原微生物威胁城市景观水环境安全。利用陶化后的淤泥颗粒固定蛭弧菌净化城市景观水体中病原微生物,可避免物化消毒对景观水体中其他动植物造成伤害。陶化淤泥颗粒固定蛭弧菌及固定化蛭弧菌对大肠杆菌、实际景观水体中总大肠菌群和粪大肠菌群裂解的试验结果表明:淤泥陶化温度为800℃、吸附时间为6 h、培养温度为30℃、摇床转速为140 r/min时,蛭弧菌固定化的效果最好;在此条件下固定的蛭弧菌,在72 h的试验周期内,对大肠杆菌的去除率达到97.4%,远超对照组的38.4%;采用陶化淤泥颗粒固定蛭弧菌去除城市景观水体中总大肠菌群和粪大肠菌群两种指示性病原微生物,去除率分别达到97.5%和78%。  相似文献   

6.
蛭弧菌对草鱼池水质及细菌类群的影响   总被引:1,自引:0,他引:1  
研究了蛭弧菌对草鱼池水质及细菌类群的影响,结果表明:蛭弧菌对养殖环境的主要水化指标具有明显的改善作用,实验组的平均COD、NH3-N、硫化物值显著低于对照组(P<0.05),实验组的DO显著高于对照组(P<0.05),而实验组与对照组的pH值差异不显著(P>0.05);池水细菌总数及致病菌的数量也随着蛭弧菌浓度的增加而发生几何级数减少.  相似文献   

7.
蛭弧菌指示和净化海水的研究   总被引:19,自引:0,他引:19  
厦门近岸海水海洋噬菌蛭弧菌的数量与海水中弧菌类的数量成正相关.灭菌海水中只加蛭弧菌,其数量出现负增长.若同时加入蛭弧菌和宿主菌鳗弧菌8927菌株,则蛭弧菌数增加、增加速率随宿主菌浓度增加而增加,并导致宿主菌数减少,此时宿主菌随培养时间延长而减少,但减少速度缓慢,15d仅减少26%.  相似文献   

8.
海洋噬菌蛭弧菌对对虾病原菌及其他细菌的寄生作用   总被引:20,自引:0,他引:20  
用宿主双层琼脂平板法,测定海洋噬菌蛭弧菌对25株对虾病原菌和大肠杆菌、枯草杆菌、绿脓杆菌及金黄色葡萄球菌的寄生作用,结果表明噬菌蛭弧菌菌株不同寄生的范围不同,但所有供试寄主细菌都能被某些蛭弧菌寄生,形成清晰的噬斑.用相差显微镜和电镜观察蛭弧菌的形态及噬菌过程  相似文献   

9.
有益微生物在暗尾东方鲀养殖中应用的研究   总被引:1,自引:0,他引:1  
研究结果表明噬菌蛭弧菌和光合细菌结合使用对暗尾东方鲀养殖环境具有明显的改善作用,并能有效提高暗尾东方鲀的成活率,对暗尾东方鲀也有一定的促生长作用.25 d后实验组比对照组池塘中的细菌总数少2个数量级,70 d后实验组比对照组池塘中的细菌总数少3个数量级;25 d后对照组COD为6.45 mg/L,使用噬菌蛭弧菌浓度为3、5、10 mL/m3及光合细菌皆为5 mL/m3,实验组的COD分别为4.66、4.46、4.38 mg/L;25 d后对照组NH3-N为0.53 mg/L,使用噬菌蛭弧菌浓度为3、5、10 mL/m3及光合细菌皆为5 mL/m3,实验组的NH3-N分别为0.38、0.35、0.34 mg/L;90 d后对照组NH3-N为0.52 mg/L,使用噬菌蛭弧菌浓度为3、5、10 mL/m3及光合细菌皆为5 mL/m3,实验组的NH3-N分别为0.25、0.23、0.22 mg/L;25 d后对照组硫化物为0.018 mg/L,使用噬菌蛭弧菌浓度为3、5、10 mL/m3及光合细菌皆为5 mL/m3,实验组的NH3-N分别为0.014、0.012、0.010 mg/L,90 d后对照组硫化物为0.018 mg/L,使用噬菌蛭弧菌浓度为3、5、10 mL/m3及光合细菌皆为5 mL/m3,实验组的硫化物分别为0.009、0.008、0.007 mg/L.使用噬菌蛭弧菌浓度为3、5、10 mL/m3及光合细菌皆为5 mL/m3,实验组暗尾东方鲀的成活率分别比对照组提高3.3%、7.6%、7.4%;使用噬菌蛭弧菌浓度为3、5、10 mL/m3及光合细菌皆为5 mL/m3,实验组暗尾东方鲀分别比对照组平均净增长12、17、15 g.  相似文献   

10.
通过对凡纳滨对虾育苗过程中细菌的数量、组成以及部分水质因子进行全程跟踪检测,分析了甲醛和抗生素对育苗水体细菌的影响,研究了蛭弧菌微生态制剂的水质调节效果.结果表明,使用甲醛和抗生素不能有效控制育苗水体的细菌总数,但能改变水体的优势菌群和组成,保持水体蛭弧菌的优势地位对控制细菌总数有较为明显的效果.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
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   

14.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

15.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
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   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

20.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

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