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1.
赵乐  郝艳阳  马志斌  王韬 《科技资讯》2011,(10):209-210
本实验针对在阿维菌素发酵过程不同阶段,采用变温控制对发酵效价的影响进行了研究。结果表明,在发酵过程前期(0~72h)温度控制在28.0±0.5℃,中期(73h~168h)提高温度至29.0±0.5℃,发酵后期(168h~240h)温度控制在28.0±0.5℃,得到的发酵液平均效价提高18.7%。  相似文献   

2.
红霉素摇瓶发酵控制条件的优化   总被引:1,自引:0,他引:1  
文章讨论摇瓶发酵控制条件对红霉素发酵水平的影响。通过单因素和正交实验优化,最佳发酵条件为A1B2C2D2:前期发酵、中期和后期发酵三阶段发酵温度分别为31℃、33℃、29℃,发酵起始pH值为6.7,摇床转速控制为:0~48 h为220 r/min,48~96 h为300 r/min,96~144 h为220 r/min,144~168 h为150 r/min。优化后菌株UL5的发酵水平比优化前提高15.54%。  相似文献   

3.
以糯米为原料,以红曲和甜酒曲的混合曲为菌种制作红曲甜酒酿.通过单因素和正交试验对发酵工艺进行优化,确定最佳工艺参数为接种总量1. 5%,红曲与甜酒曲配比1∶1,加水量50%,发酵温度33℃,发酵时间72 h;同时对发酵过程的几个主要指标的变化进行了检测,结果显示,总酸在发酵时间48 h前快速上升,48 h后上升缓慢;糖度前期、中期上升较快,后期上升缓慢;酒精度前期缓慢上升,中后期急剧上升;霉菌数呈先增加后减少的趋势,酵母菌数一直呈上升趋势.  相似文献   

4.
生物农药固态发酵条件的研究   总被引:11,自引:0,他引:11  
探讨了以麸皮为主要原料进行固态发酵生产生物农药的方法,研究了不同培养基成分及培养条件对苏云金杆菌毒力效价的影响.试验结果表明,最适发酵培养基为:麸皮1000g,玉米粉20g.豆粕150g,KH2PO4 2g;最佳发酵条件为:原料含水量为60%,发酵温度30℃、pH为7.5,培养时间48h.结果分析表明,苏云金杆菌的毒力效价达5400IU/mg。  相似文献   

5.
啤酒糟固态发酵生产生物农药条件的优化   总被引:6,自引:0,他引:6  
探讨了以啤酒糟为主要原料进行固态发酵生产生物农药的方法,研究了不同培养基成分及培养条件对苏云金杆菌毒力效价的影响.实验结果表明,最适发酵培养基为:啤酒糟1000g,玉米粉15g,豆粕180g,KH2PO42g;其最适发酵条件为:原料含水量为60%,发酵温度30℃、pH为7.5,培养时间56h.分析结果表明,苏云金杆菌的毒力效价达4960IU/mg.  相似文献   

6.
真菌转化菊糖生产低聚果糖的研究   总被引:2,自引:0,他引:2  
研究了真菌黑曲霉(Aspergillus niger)A97转化菊糖生产果糖的适当条件,结果表明:发酵初始pH为5.5 ̄6.0,菊糖浓度为2%,接种量5%,控制前期发酵温度为28 ̄33℃,36h后发酵温度为32 ̄33℃,发酵周期为42h左右,最高产酶达254.7μ/ml,在10L自控发酵罐中,产酶达到同样水平。产品总还原糖含量68%,其中果糖95%,葡萄糖5%。  相似文献   

7.
通过对茁芽短梗霉As3.2756四次紫外诱变,获得了一株高产普鲁兰的变异株PB518,使糖的转化率达55%以上,经多次传代表明该菌株稳定。同时考察了该变异株的发酵条件,最适条件为起始pH6.0,接种量3.0×10 ̄8个/mL通气量为培养基占摇瓶体积的1/10,发酵温度28℃,发酵时间96h。  相似文献   

8.
金色链霉菌摇瓶培养适宜的接种量为3.2%、接种时间为25h、温度在28℃左右。4g/L的硫酸铵和0.043g/L无机磷有利于产物金霉素(CTC)合成。酵母膏的加入对CTC的合成有一定促进作用,以3g/L的效果较好。在50L发酵罐中,较低浓度的无机磷对CTC发酵有利;酵母膏的加入量以4.2g/L最佳,产物效价比酵母膏加入量为2.8g/L和5.6g/L时高3.1%和9.79/5,优化发酵过程的CTC产率提高了18%。  相似文献   

9.
普洱茶不同发酵时期微生物群落宏转录组学研究   总被引:1,自引:0,他引:1  
分离提取了普洱茶发酵前期和发酵中期茶叶样本中的微生物菌群全mRNA,并通过Illumina测序得到普洱茶发酵前期17376转录文本结果以及普洱茶发酵中期14456个转录文本结果。对测序结果的注释结果表明黑曲霉(Aspergillus niger)在两个阶段都占有绝对优势;对两个样本差异表达部分GO功能和KEGG PATHWAY的对比分析表明,适应渥堆发酵环境变化的微生物(如黑曲霉等)对普洱茶发酵过程起到了决定性的作用。  相似文献   

10.
研究了假丝酵母WHS112以豆油为唯一碳源生产生物表面活性剂甘露糖赤藓糖醇脂的摇瓶发酵条件,得到的最适条件分别为接种量5%-8%,氮源为0.2%NaNO3,温度为25℃,250ml三角瓶装液量为30ml,初pH6.0;通过逐步增大正构烷烃浓度的方法进行了实验室内的菌种诱导改良工作,并通过  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.
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   

13.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
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   

19.
<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   

20.
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