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1.
实验研究了雨生红球藻FACHB-712藻株对氨苄青霉素、卡那霉素、链霉素、庆大霉素4种抗生素的敏感性以及这4种抗生素对FACHB-712藻株生长的影响,结果表明:低质量浓度的链霉素、卡那霉素、庆大霉素对FACHB-712藻液中的细菌具有明显的抑制作用.但链霉素和卡那霉素的质量浓度为10μg·m L~(-1)时,雨生红球藻FACHB-712藻株的生长受到明显抑制,庆大霉素的质量浓度低于10μg·m L~(-1)时,对FACHB-712藻株的生长无明显影响.氨苄青霉素质量浓度为10~200μg·m L~(-1)时,对FACHB-712藻株生长具有促进作用,质量浓度为500μg·m L~(-1)时,则对FACHB-712藻株生长有一定的抑制作用.在此基础上,采用6种方法添加抗生素,除了A(300μg·m L~(-1)的氨苄青霉素和5μg·m L~(-1)庆大霉素连续处理6 d)和B(300μg·m L~(-1)的氨苄青霉素和5μg·m L~(-1)卡那霉素连续处理6 d)两种处理方法外,其他处理方法均能获得无菌藻株.无菌藻株与有菌藻株相比较,无菌藻株不易老化,游动营养细胞较多,厚壁孢子数量较少,但无菌藻株与有菌藻株在潜在最大光合效率、潜在最大光合速率、耐受强光的能力以及对光强的利用能力等光合能力方面无统计学上差异(P0.05).  相似文献   

2.
3种常用抗生素应用于海洋微藻无菌化培养的研究   总被引:4,自引:0,他引:4  
采用青霉素、硫酸庆大霉素、头孢他啶3种常用抗生素处理海洋微藻,以确定分离、纯化微藻时对藻细胞无害并能抑制伴生杂菌生长的抗生素浓度和培养时间.结果表明:青霉素的性质比较温和,能广泛地用于微藻的除菌;低剂量的硫酸庆大霉素也可起到类似作用;头孢他啶对各种微藻表现出来的作用并不相同,应慎用.对特征点进行方差分析也证实了以上结果,故建议海洋微藻的除菌以加入300 mg/L的青霉素或100 mg/L的硫酸庆大霉素作为一般用藻的除菌,培养6 d继代.  相似文献   

3.
对影响盐藻生长的NaNO3、NaH2PO4、NaHCO3和VB1、VB12、VH等几种主要营养盐进行了优化,在单因素实验的基础上做了四因素三水平正交实验,实验结果得出优化配方为N/P值固定为f/2培养基,NaNO3和NaH2PO4添加量为f/2培养基的10倍、NaHCO3 0.4g/L、VB1 100μg/L、VB12 1.0μg/L,其他元素按f/2培养基添加.对盐藻的选择标记进行了研究,选择了氯霉素、G418、潮霉素3种抗生素进行实验,得出氯霉素适合作为盐藻基因工程的筛选抗生素,CAT基因为其阳性筛选标记基因,固体培养基筛选浓度为80μg/mL.为该藻的进一步高密度大规模培养和分子水平的研究提供了依据.  相似文献   

4.
研究4种杀虫药物对盐生杜氏藻生长的致毒效应,结果表明:虫敌、纤源净、马拉硫磷、虫水安均不同程度上抑制盐生杜氏藻的生长繁殖,超过一定浓度后引起藻体的负增长,同时采用回归方程求出了4种药物对盐生杜氏藻24、48、72、96 h的半效应浓度EC50.  相似文献   

5.
在实验室条件下,研究了不同氮(0、0.1、0.4、0.8、1.0、1.2 g/L)、磷(0、0.015、0.025、0.030、0.045、0.060 g/L)浓度下杜氏盐藻生长增殖的关系和特征,以及氮磷比(c(N)/c(P))变化等对该藻生长的影响。实验结果表明:杜氏盐藻对氮、磷有着较强的适应能力,浓度增大藻增长率增大,浓度继续增大反而抑制藻的增长,属于营养依赖型藻类。不同氮质量浓度梯度对杜氏盐藻生长具有显著性影响(P<0.05),但对杜氏盐藻生长率K的影响不显著(P>0.05),最适宜的氮浓度为1.0 g/L;不同磷质量浓度梯度对杜氏盐藻的生长和生长率K具有显著性的影响(P<0.05),最适宜的磷浓度为0.025 g/L。当c(N)/c(P)为40时,最适合杜氏盐藻的生长。  相似文献   

6.
为了探究博来霉素对野生型椭圆球藻(Chloroidium ellipsoideum,SD-0701)和导入外源基因Gus的转基因椭圆球藻(SD-0702)生长以及油脂积累的影响,在Knap培养基中添加不同质量的博来霉素,测量2个藻株在不同处理下的细胞密度、藻粉产量以及油脂产量.结果发现,培养基中不添加博来霉素时,SD-0701的生长速率、藻粉和油脂产量均高于SD-0702.培养基中添加博来霉素能够抑制SD-0701和SD-0702的生长,对SD-0701的抑制作用更明显.培养基中博来霉素的质量浓度为4μg/mL时,2个藻株的生长就开始受到抑制,博来霉素对SD-0701的抑制率达到87.31%,对SD-0702的抑制效果不明显,抑制率仅有12.23%. SD-0701对博来霉素更敏感,添加了博来霉素的处理组中,SD-0701的藻粉产量微小无法制备;SD-0702在不同质量浓度的博来霉素培养基中均能够生长,且可获得藻粉和油脂,但产量随着博来霉素质量浓度的增加而降低.博来霉素质量浓度为4μg/mL时,SD-0702的藻粉产量和油脂产量抑制率分别为12.44%和8.49%,博来霉素质量浓度高达16μg/mL时,藻粉产量和油脂产量的抑制率分别为66.31%和75.46%.低质量浓度博来霉素(≤8μg/mL)对SD-0702的含油率有提升作用,高浓度则会降低SD-0702的含油率.以上结果表明,野生型椭圆球藻中导入外源基因Gus会轻微抑制细胞生长,但增强了椭圆球藻对抗生素的抗性,使其能够在低抗生素污染水体中生长并生成代谢物.  相似文献   

7.
研究了纳米Fe2O3颗粒的悬浮液对蛋白核小球藻和斜生栅藻生长的影响.通过生长抑制实验确定了纳米Fe2O3促进2藻种生长的最佳浓度以及临界浓度范围,通过测定光合特性以及氧化应激水平和酶活性层面确定了纳米Fe2O3对2藻种生长的内部物质变化的影响,并分析其具体调节机制.结果表明,纳米Fe2O3颗粒的悬浮液对2藻种生长的最适浓度是6 mg/L,高于此浓度即对藻细胞造成毒性抑制.该实验结果可为工业生产废水的处理排放提供参考.  相似文献   

8.
探讨了营养盐铁、硅及植物激素脱落酸(ABA)单因子对三角褐指藻(Phaeodactylum tricornutum)的生长、油脂含量(%干重)及油脂产量的影响.采用光密度值OD450评价微藻的生长状况,以溶剂浸提法提取油脂.结果表明:(1)铁处理组中,铁浓度在0~46.57 μmol/L范围内时,藻的生长速率随铁浓度提高而增大;铁浓度为11.64 μmol/L时,油脂含量达30%,高于其它铁浓度培养;当铁浓度为11.64 μmol/L时,油脂产量最高--是无铁培养的2.8倍;(2)硅处理组中,低含量硅盐(4.6 μmol/L)不仅促进了藻的生长而且提高了油脂含量,油脂产量比高含量硅盐(42.6 μmol/L)培养提高了40%;(3)ABA处理组中,1 mg/L ABA不仅促进了藻的生长而且提高了油脂含量,油脂产量比对照提高了50%;5 mg/L ABA虽提高了油脂含量但却抑制了藻的生长,油脂产量和对照相当;15 mg/L ABA抑制了藻的生长、降低了油脂含量.用气相色谱分析微藻的脂肪酸组成,结果显示:1 mg/L ABA明显影响了三角褐指藻的脂肪酸组成,以高产量油脂(4.6 μmol/L硅盐、1 mg/L ABA培养)为原料制备出的生物柴油的质量将会提高.  相似文献   

9.
研究不同浓度的过氧化氢对在不同光质(白、红、黄、蓝光)下生长的杜氏盐藻SZ-05(Dunaliella salina SZ-05)生长与代谢产物积累的影响.结果表明,当过氧化氢浓度从10-6 mol·L-1增至10-4 mol·L-1时,对盐藻的生长有微弱的促进作用,各种光质培养条件下盐藻的细胞密度均逐渐增大至最大值,其中红光下的盐藻细胞密度最大,为6.19×106 ml-1;当过氧化氢的浓度增加到10-3 mol·L-1时,细胞密度减小,表现为抑制作用.在过氧化氢浓度为10-6 mol·L-1时,不同光质培养条件下盐藻的单个细胞内β胡萝卜素的含量均达到最大值,其中红光单个细胞内的β胡萝卜素的含量最大,为0.790 pg.当过氧化氢浓度继续增加时,单个细胞内β胡萝卜素的含量降低,表现为抑制作用.在过氧化氢浓度为10-3 mol·L-1时,红光条件下生长的盐藻胞外多糖含量获得最大值,为5.97 pg.  相似文献   

10.
将不同质量浓度的CuCl_2溶液添加到培养基中,研究重金属铜对杜氏盐藻(Dunaliella salina)胁迫的生理响应.分别用不同质量浓度的CuCl_2溶液培养盐藻,检测盐藻的光合色素、可溶性多糖、蛋白质、SOD及MDA质量浓度的变化.结果显示,铜可抑制盐藻细胞的生长,且呈剂量-效应关系,72 h的EC50为9. 55 mg/L.随着铜质量浓度的增加,各质量浓度组盐藻细胞内叶绿素a、b、总叶绿素、类胡萝卜素、多糖和蛋白质质量浓度均显著性降低(P 0. 05或P 0. 01).铜可导致盐藻细胞氧化损伤,随着铜质量浓度的升高,SOD活力先升高后降低,MDA质量浓度升高.表明铜可以抑制盐藻细胞内光合色素、多糖和蛋白质的合成.盐藻对铜胁迫的响应机制可能是通过抗氧化防御系统.  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.
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   

13.
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   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

15.
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   

16.
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   

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.
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   

19.
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   

20.
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