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1.
Fe^2+和Fe^3+对E.coli DH5α及其耐乙酸突变株DAl9的代谢有较大影响。在以葡萄糖为碳源的基本培养基中,添加Fe^2+或Fe^3+后DH5α生长改善,菌体浓度增加,菌体得率(YX/G)提高,但同时产乙酸量也大为增加,且在添加Fe^2+后增加更多,然而其单位菌体的产乙酸量(YA/X)降低。DAl9在添加Fe^2+或Fe^3+后生长改善,YX/G提高,同时产乙酸大大减少,YA/X和乙酸得率(YA/G)大大降低。DAl9的生长还与Fe^2+的添加时间有关,在培养过程中添加Fe^2+越早,细胞浓度和YX/G增加的幅度越大,同时产乙酸、YA/X及YA/G下降的幅度也越大;在12h及其之后添加对DAl9生长没有明显影响。DH5α和DAl9在添加Fe^2+后生长改善的效果比Fe^3+明显。  相似文献   

2.
氯化汞对南瓜组培苗生长影响的研究   总被引:1,自引:0,他引:1  
本实验是将南瓜组培苗培养在含不同浓度氯化汞的MS培养基上,通过对组培苗的叶片数、株高、鲜重、叶绿素含量等指标的测试,研究重金属汞对组培苗的影响。结果表明,当氯化汞浓度不高于10μg/mL时,对南瓜组培苗的生长无明显影响,南瓜组培苗的鲜重和Ch1.a、Ch1.b的含量略有提高,并且在氯化汞浓度为10μg/mL时,叶绿素含量、鲜重、株高均达到最大值。当浓度高于10μg/mL时,氯化汞对南瓜组培苗产生毒害作用并随着其浓度的升高而增加,当浓度为180μ/mL时,3组组培苗全部死亡。  相似文献   

3.
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   

4.
玫瑰茄细胞生长及其花黄素产生的研究   总被引:1,自引:0,他引:1  
本文对玫瑰茄细胞培养产生产花黄素进行了研究。实验结果表明,细胞在含1μmol/L2,4-d及0.5μmol/LKT的B5悬浮培养基中生长良好,有产生较多的花黄素,为172mg/L,占细胞干重的2.1%。细胞的比生长速率为0..282d^-1,倍增时间为59h,色素产生的动力学方程为:dP/dt=(3.333 0.1830μ)x。2,4-D的浓度升高对色素的产生有抑制作用。蔗糖的最适浓度为3%。培养基中有无Fe^ 对产物形成的影响作用极微,而光照对细胞生长和色素形成都是必需的。  相似文献   

5.
大肠杆菌DH5α及其耐乙酸突变株生长和产乙酸规律   总被引:5,自引:0,他引:5  
大肠杆菌DH5α的耐乙酸突变株DA19在复合培养基中有生长优势,最大比生长速率提高,产乙酸减少,对乙酸的耐受力增加。在基本培养基中DA19生长优势更加明显,消耗葡萄糖速率加快,单位菌体产乙酸得率YA/X比DH5α低,以消耗葡萄糖为基准的菌体得率YX/G提高。在添加乙酸的基本培养基中,DA19细胞浓度高于DH5α,更快利用葡萄糖。DA19在高葡萄糖浓度下(102g/L)也能良好生长,菌体浓度达26g/L,YX/G为0.257g/g。在变速补料分批培养中,DA19可以有效地控制乙酸的生成,细胞浓度达到20g/L,YX/G为0.360g/g,为其在高密度培养中的应用奠定了基础。  相似文献   

6.
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   

7.
分光光度法测定微量铁实验方法的改进   总被引:1,自引:0,他引:1  
建立了邻二氮菲分光光度法测定微量铁的改进方法,显色剂邻二氮菲的浓度为1.0g/L,缓冲液为NaAc—HAc溶液(pH为4.6),盐酸羟胺溶液浓度为10g/L,用1cm比色皿在510nm的波长处测定显色液的吸光度。Fe^2+的浓度在0—2μe,/mL的范围内与吸光度成良好的线性关系(为0.9998),测定结果准确度高。  相似文献   

8.
分析了坛紫菜叶状体细胞对甲醇、乙醇、异丙醇、1,3-丙二醇等4种有机溶剂的敏感性.结果表明:体细胞对1,3-丙二醇敏感.在实验最低剂量(0.2μL/mL)下对紫菜体细胞就表现出较强的致死作用;对甲醇有较强的耐受性.在最高的1.0μL/mL处理浓度组.生长发育状况与对照组无明显差别;乙醇在浓度高于0.6μL/mL时强烈抑制体细胞的分裂;异丙醇随着浓度的升高表现出使体细胞向细胞团方向分化.而叶状体的形成则受到抑制.本实验结果表明.在用外源化合物处理紫菜叶状体细胞时.甲醇在1.0μL/mL浓度范围内可作为合适的有机溶剂。  相似文献   

9.
目的:研究红景天苷对骨髓间充质干细胞(Bonemesenchymalstemcells,BMSCs)生物学活性影响。方法:采用贴壁法分离培养BMSCs,检测细胞表面分子表达对所获干细胞进行鉴定。以终浓度为10¨g/mL红景天苷与BMSCs共培养,通过形态学观察和MTT法分析研究其对BMSCs生物学特性影响。结果:成功培养出BMSCs,免疫荧光染色显示,培养的第3代BMSCs表达CD29、CD44干细胞标志。10μg/mL红景天苷与BMSCs共培养后,较对照组细胞生长更为旺盛,更为规整,形成典型的“鱼群状”。生长曲线显示,实验组细胞较对照组生长稳定,增殖能力活跃。结论:10μg/mL红景天苷可促进BMSCs增殖分化,又不影响细胞增殖分化等生物学特性。  相似文献   

10.
盾叶薯蓣细胞生长特征的研究   总被引:3,自引:0,他引:3  
以MS固体培养基为基本培养基,研究了盾叶薯蓣(Dioscorea zingiberensis C.H.Wright)细胞在不同接种量和NAA,BA浓度配比条件下的生长特征。结果表明:盾叶薯蓣细胞在Ms培养基,附加NAA2.0mg/L,BA0,5mg/L,蔗糖30g/L,琼脂7g/L,pH6.0,接种量0.8~1.2g/瓶条件下,生长较好。应用Logistic方程对薯蓣细胞生长进行模拟能够较好地描述细胞的生长过程,细胞生长曲线呈“S”形,生长过程可分为延迟期、指数生长期和减速期。为发酵培养盾叶薯细胞和研究其次生代谢产物提供了理论依据。  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 Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
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   

15.
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   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
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   

19.
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   

20.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

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