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1.
两歧双歧杆菌固态培养的研究   总被引:3,自引:0,他引:3  
两歧双歧杆菌 (Bifidobacteriumbifidum )ATCC2 95 2 1在含质量分数为 2 0 %惰性固态物质 (纤维素 )的MRS固态培养基中 ,若营养物的质量分数比液体培养基中营养物的质量分数提高 1倍 ,则菌体生长量也相应提高 1倍 (达 1 9× 10 8cfu/ g) .经过 3种固态基质作比较后 ,发现大豆渣和麦麸为佳 ,前者的含菌量最高达 5 4×10 8cfu/ g ,后者含菌量最高可达 2 3× 10 8cfu/ g .通过加入可中和所产酸量的CaCO3 ,并用缓冲液代替水配制培养基 ,结果发现用pH6 8的缓冲液配制培养基 ,培养后含菌量可达 16× 10 8cfu/g ,比对照的液体培养提高了11 4倍 .通过“液 固先后培养”并测定其中活菌数的变化 ,进一步证明了固态培养的优越性 .  相似文献   

2.
以所筛选的硅酸盐细菌RM 0 1菌株为材料 ,对所需的培养基和培养条件进行了研究分析 .在选择的适宜培养基中 (TR复合培养基 ) ,对培养基pH值、培养温度、摇床转速及摇瓶装液量等影响因素进行了正交实验 .结果表明 ,在pH为 7、温度 36℃、转速 2 2 0r/min、装液量 5 0mL时 ;硅酸盐细菌菌量可达 10 .6× 10 8个 /mL  相似文献   

3.
实现了杂交瘤细胞的体外无血清低蛋白培养。考察了血清浓度、基础培养基和接种密度对细胞生长的影响。在含5%血清培养基、1%血清培养基和无血清低蛋白培养基中适应生长的细胞,μ分别为0.68、0.45、0.44d-1,qGlc分别为13.4×10-9、13.1×10-9、19.2×10-9mmol/(cell·分别为39.4×10-9、44.1×10-9、37.7×10-9mg/(cell·d),YMAb/Xv分别为52.6×10-9、d),qMAb57.8×10-9、54.4×10-9mg/cell,YLac/Glc分别为2.0、1.95、2.0mmol/mmol。无血清培养中葡萄糖代谢途径不变,参与细胞维持代谢的葡萄糖比例增大。血清浓度降低,延迟期变长,最大活细胞密度下降。基础培养基影响细胞的最大活细胞密度,不影响生长速率。无血清培养基中细胞的接种密度选择在0.2×106~0.3×106cells/mL。  相似文献   

4.
以玉米粉酶解物和大豆蛋白水解物为主要原料,以蔬菜汁为促生长物质,考察培养基的组成、接种量、起始pH和温度对嗜热链球菌增菌的影响.试验发现,复合蔬菜汁具有协同增菌作用,芹菜汁:胡萝卜汁∶竹笋汁=2∶2∶1时,增菌效果较好;以正交试验设计对影响增菌的培养液组成、复合蔬菜汁添加量和接种量进行优化,得出增菌培养的最佳工艺:在100 mL大豆蛋白水解液和玉米粉酶解物的培养液(体积比为45∶55)中,添加复合蔬菜汁30 mL,以5%的接种量,起始pH 6.8,42℃培养20 h,嗜热链球菌增菌效果最好.  相似文献   

5.
桦褐孔菌深层发酵培养条件的优化   总被引:1,自引:0,他引:1  
目的优化桦褐孔菌深层发酵条件。方法采用L9(34)正交试验法对培养基进行优化。结果桑黄菌体发酵的最优方案是8%葡萄糖,1.60%酵母粉,0.3%KH2PO4,0.15%MgSO4,VB110mg/100mL,pH6.0,接种量为10%,装液量为100mL/300mL三角瓶,150r/min,恒温培养7天,生物量可达1.350g干菌丝每100mL发酵液。结论桦褐孔菌可以用深层液体发酵培养获得菌丝体,桦褐孔菌具有限氧生长的生物学特性。  相似文献   

6.
目的提高苏云金杆菌NU-1制剂的毒力。方法通过苏云金杆菌NU-1在6种培养基中发酵,研究其菌体生长、pH值变化、芽孢形成、伴孢晶体率、发酵周期等。并对其晶体蛋白进行了提纯和测定。结果5号培养基产量最高,30℃发酵40h时菌数可达80.4×108个/mL,伴孢晶体率大于90%,晶体蛋白浓度达6.312mg/mL。结论用5号培养基作的制剂毒力最强。  相似文献   

7.
本文对水葫芦采用不同浓度的NaOH预处理,研究其对水葫芦厌氧发酵产气量的影响. 在培养基中分别加入乙酸钠、碳酸氢钠和发酵上清液培养沙角衣藻,讨论对沙角衣藻生长的影响. 结果发现,2% 浓度的NaOH预处理对根发酵产气最为有利,根叶混合物经预处理后可获得802.6mL/100g新鲜底物的最佳产气量;以乙酸钠作培养基碳源,沙角衣藻生物量能得到明显积累,可从初始的0.4×106个/mL达到10d后的2.84×106个/mL.  相似文献   

8.
为实现酿酒酵母(Saccharomyces cerevisiae)的高密度发酵及在奶啤生产中的应用,对一株来源于新疆传统发酵驼乳中的酿酒酵母TR2生长所需的增殖因子与培养条件进行研究,并建立该菌株的发酵动力学模型。采用单因素实验对培养基中的碳源、氮源以及无机盐的种类与浓度进行筛选,通过响应面试验与正交试验的方法分别优化该菌的培养基成分和发酵条件,采用Matlab软件对该菌株菌体生长和葡萄糖消耗动力学模型分别进行非线性拟合。结果表明,优化培养基配方为葡萄糖53.4g/L、蛋白胨21.5g/L、酵母膏10g/L、磷酸二氢钾2.98g/L,在初始pH值为5.0、摇床转速150r/min、接种量体积分数5%、装液量60mL的条件下28℃发酵16h,细胞数量可达到6.64×108CFU/mL,其菌体生长和葡萄糖消耗动力学模型的预测值与实验值能较好地拟合,拟合度分别为0.9973和0.9784,表明所建模型能较好反映该菌的分批发酵过程。  相似文献   

9.
内生真菌Hd3菌株发酵条件优化研究   总被引:1,自引:1,他引:0  
利用Plackett-Burman设计和响应面设计方法对Hd3菌株的发酵条件进行了优化研究,确定了最佳培养基组成及培养条件.试验结果表明;Hd3菌株的摇瓶培养基配方为葡萄糖24.71 g/L,MgSO4·7H2O 1.08 g/L,土豆244.17 g/L.发酵条件为pH 6~7,250 mL三角瓶装90 mL发酵液,接入9×103 cfu/mL菌量,31℃培养9 d.  相似文献   

10.
LR—98对肝癌细胞增殖的抑制性效应   总被引:1,自引:0,他引:1  
利用在体和离体实验相结合 ,以动物接种肿瘤细胞后的生存时间、瘤重与体重比值、肝癌细胞生存率、超氧化物歧化酶 (SOD)活性及肝癌细胞凋亡为指标 ,研究了不同剂量榄仁树叶提取物 (LR 98)对肝癌细胞增殖的抑制性效应及可能机制 .在体实验结果表明 ,5× 10 - 3g/mLLR 98处理组动物的生存时间较对照组明显延长 (P <0 .0 1) ,不同剂量处理组 (5× 10 - 3g/mL ,2× 10 - 2 g/mL ,5× 10 - 2 g/mL)的瘤重与体重比值均较对照组明显减小 (P <0 .0 5) .体外培养的细胞经不同剂量LR 98(1× 10 - 5g/mL ,5× 10 - 5g/mL ,1× 10 - 4 g/mL)作用后 ,生存率及SOD活性均显著下降 (P <0 .0 1) .流式细胞仪分析表明 ,不同剂量LR 98作用于肝癌细胞 8h后 ,在G1 期前均出现一亚二倍体峰 ,表明均能诱导肝癌细胞发生凋亡 ,凋亡率分别达 2 9.4 4 % ,2 4 .4 5%和 2 5.2 2 % .以上结果说明LR 98可显著抑制肝癌细胞增殖 .降低SOD活性 ,诱导肝癌细胞凋亡可能是LR 98抑制肝癌细胞生长的机理之一 .  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.
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   

14.
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   

15.
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   

16.
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   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

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