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1.
为了提高Monacolin K的产量,以紫红曲霉M2为出发菌株进行诱变育种(紫外诱变、常压室温等离子体ARTP诱变),通过构巢曲霉对峙培养、高效液相色谱HPLC等方法筛选高产Monacolin K的优秀突变菌株。结果显示:相对于原始出发菌株M2,两种方法均能够高效筛选到红曲菌株,对6株高产Monacolin K诱变菌株进行5次传代培养,发现诱变菌株产Monacolin K的能力均有下降;但紫外诱变菌株Z-4和ARTP诱变菌株M-43的Monacolin K产量分别下降2.83%和1.97%,表现为良好的遗传稳定性,说明Z-4和M-43具有潜在应用价值。  相似文献   

2.
采用常压室温等离子体(atmospheric and room temperature plasma,ARTP)诱变脱氮假单胞菌(Pseudomonas denitrificans)并从中筛选高产维生素B12突变株,确定等离子诱变最优处理时间75,s、输出功率100,W.通过流式细胞仪并结合核糖开关(riboswitch)感应元件检测其荧光值以初筛诱变后高产菌株,并利用48孔板高通量培养发酵,酶标仪快速检测维生素B_(12)产量,建立完整的诱变后高通量筛选体系.通过4轮ARTP诱变,筛选得到的突变株PA320-M4-1B1在250,mL摇瓶发酵6,d的条件下,维生素B_(12)产量达到(103.2±2.1)mg/L,较初始菌株PA320的(71.9±1.8)mg/L提高了43.8%,且遗传性状稳定.  相似文献   

3.
以皮状丝孢酵母GIM 2.68为出发菌株,利用紫外线(UV)进行诱变,以筛选高产油脂突变菌株.通过测定吸光度和致死率绘制出发菌株的生长曲线与致死曲线,根据形态学和生理生化特征观察对菌种进行初筛,根据生物量和油脂产量检测对菌种进行复筛.研究结果表明:出发菌株生长周期为36 h,培养12 h后进入对数生长期;利用25W紫外灯,在照射距离为36 cm条件下,照射时间为50 s,可以筛选出生物量为1.047 g/(100 mL)、油脂产量为0.374 8g/(100 mL)的突变菌株Tc3,油脂得率为35.8%,与出发菌株相比,生物量提高38.81%,油脂产量提高86.10%,油脂得率提高34.09%.  相似文献   

4.
利用空间诱变选育辅酶Q10高产菌   总被引:2,自引:0,他引:2  
 以空间搭载为诱变手段,筛选可用于工业化生产的辅酶Q10高产菌株。以类球红细菌(Rhodobacter sphaeroides)为出发菌株进行空间搭载,根据菌落形态进行初筛,摇瓶发酵进行复筛,HPLC检测含量等方法筛选辅酶Q10高产菌株。最终得到名为Shenzhou6的突变株产量比对照菌株提高30%,产量可达(0.8+0.02)g/L,经过优化培养可满足工业生产需要。同时也说明空间诱变因其复杂的空间环境条件,可以作为一种诱变手段进行工业化菌样的筛选。  相似文献   

5.
链霉菌702在林可霉素致死剂量下UV诱变研究   总被引:1,自引:0,他引:1  
徐平  熊智强  涂国全 《江西科学》2006,24(3):258-261
在林可霉素致死剂量下UV诱变筛选链霉菌702产抗细菌活性物质高产菌种,试验结果表明,紫外作用20 s对林可霉素致死突变率达到20.77%,抗药性致死突变菌株与该菌产抗细菌活性物质的高产菌株的正突变率达25%,效价提高20%以上达10%,从突变菌株中摇瓶筛选到42-3473菌株,摇瓶发酵生物效价达2062μg/mL,比诱变出发菌株生物效价提高了70%。  相似文献   

6.
为探讨海盐田中的嗜盐真菌类型及其抗肿瘤作用,采用稀释涂布法和平板划线法分离海盐田中的可培养真菌,并基于ITS基因序列分析鉴定菌株,通过FGFR2过表达和未过表达的肿瘤细胞增殖抑制活性以及酶联免疫吸附法(Enzyme-Linked Immunosorbent Assay,ELISA)评价真菌的抗肿瘤作用。本研究分离得到11种嗜盐真菌,隶属于3科4属。真菌Epicoccum sorghinum(编号GXIMD02001)的提取物对FGFR2过表达的乳腺癌细胞MDA-MB-231-(S252W)增殖有较强的抑制作用,其半抑制浓度IC50为11.02 μg/mL,而对FGFR2未过表达乳腺癌细胞MDA-MB-231几乎没有抑制活性,该提取物在1 mg/mL浓度下对FGFR2蛋白激酶活性抑制率为91.5%;两株真菌(编号GXIMD02004和GXIMD02009)对FGFR2表达乳腺癌细胞MDA-MB-231和MDA-MB-231(S252W)增殖抑制的IC50为11.94-16.41 μg/mL;5株真菌的IC50为219.2-449.7 μg/mL。嗜盐真菌(编号GXIMD02001)是首次报道具有靶向FGFR2抗肿瘤作用的海洋真菌,部分嗜盐真菌具有较好抗肿瘤作用,本研究为北部湾海洋微生物来源的抗肿瘤药物开发利用提供科学依据。  相似文献   

7.
为了获得高产的工业用酿酒酵母(Saccharomyces cerevisiae)菌株,利用己烯雌酚(DES)和UV对酿酒酵母菌QD进行连续复合诱变,采用改进的发酵小管集气法结合乙醇定量测定来进行突变株的筛选,并与常规复合诱变及筛选方法进行比较.结果表明:连续复合诱变的正向突变率最大值为18.9%,与常规诱变方法的最大正向突变率15.6%相比提高了21.2%,说明运用该诱变方法能获得较高的正向突变率;改进的筛选方法可以快速筛选出目的突变株,同时,获得了一株高产乙醇的突变株,在甘蔗汁发酵培养基中其乙醇产量达到9 720 mg/100 mL,比常规诱变方法筛选到的突变株乙醇产量(9 170 mg/100 mL)高出6.0%;与常规诱变方法相比,连续复合诱变方法不仅能够得到较高的正向突变率,而且能够获得更加高产的突变株.  相似文献   

8.
将常温常压等离子体(Atmospheric and Room Temperature Plasma,ARTP)诱变和无水亚硫酸钠构建的氧限制筛选模型相结合,通过适合辅酶Q10生产菌株的24孔板高通量快速培养技术,选育了类球红细菌Rhodobacter sphaeroides耐氧限的高性能突变株.实验结果表明:该菌株诱变...  相似文献   

9.
为提高真菌Aspergillus sp.GXIMD02003的曲酸产量,本研究对其利用大米固体培养基发酵的条件进行优化,旨在获得成本低廉的曲酸原料,促进曲酸的工业化生产。研究采用单因素控制变量法考察最佳盐度和最佳发酵时间,通过HPLC法测定曲酸的产量。结果表明真菌Aspergillus sp.GXIMD02003产曲酸的最佳发酵条件为在2%海盐的大米固体培养基中发酵30 d,在此条件下1 000 g大米培养基能够发酵产生24.2 g曲酸。因此,海洋来源真菌Aspergillus sp.GXIMD02003可以作为曲酸的生产菌株,海盐浓度影响该菌株的曲酸代谢。  相似文献   

10.
为研究海洋来源真菌橘青霉(Penicillium citrinum)的次生代谢产物及其活性,采用凝胶柱层析、正相硅胶柱层析以及高效液相色谱等方法对菌株发酵液的乙酸乙酯提取物进行分离,通过LC-MS、NMR结构鉴定和文献数据对比等方法进行鉴定。结果表明,分离到的7个已知化合物经鉴定分别为3,3-二吲哚烷基-1,2-丙二醇(1)、robillafuran (2)、asperfuran A (3)、gamahorin (4)、7-羟基-5-甲氧基-4,6-二甲基-异苯并呋喃酮(5)、5-甲氧基-4,6-二甲基-7-氧-α-L-鼠李糖基-异苯并呋喃酮(6)、pestynol (7)。化合物1-7均为首次从青霉属真菌中分离得到,化合物1首次从真菌的次生代谢产物中发现。活性筛选结果表明,化合物7具有抗菌活性,化合物17对Marc-145细胞具有较强的细胞毒活性,半数致死浓度(Median Lethal Concentration,LC50)值分别为57.397 μg/mL和35.386 μg/mL;在LPS诱导的BV-2细胞模型中,化合物24在浓度为12 μg/mL时,BV-2细胞的存活率分别为76.77%和69.69%,具有潜在的抗神经炎症活性。  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.
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.
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   

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.
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   

18.
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   

19.
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   

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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