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玫烟色拟青霉最适液体培养条件的研究 总被引:1,自引:0,他引:1
通过对不同营养和不同培养条件下玫烟色拟青霉菌丝生物量和产孢量的研究,结果表明:葡萄糖为玫烟色拟青霉液体培养的最适碳源,蛋白胨为该菌生长的最适氮源,C/N为10∶1~20∶1最适于玫烟色拟青霉菌丝生长和产孢;25℃2、4 h全光照条件,对该菌生长和产孢均有利。接种后144~168 h时,菌丝生物量和产孢量均达到高峰,分别为31.72 mg/mL、24.62孢子/mL,为黑暗条件下的1.5倍和18.3倍,因此玫烟色拟青霉液体发酵终点应选择在接种后144~168 h为最好。 相似文献
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研究了液态发酵条件下通气量、转速、pH、可溶性淀粉浓度对松茸菌丝生长量的影响,探讨了可溶性淀粉稳定pH的作用机理。试验结果表明:通气量≤0.4vvm时松茸菌丝产量随通气量的增大而增长,当通气量>0.5vvm时,菌丝产量增加不明显;转速增大菌丝产量增加,转速>80r/min,菌丝产量下降;松茸菌丝发酵的最适pH为5.5,初始pH不同,发酵罐中培养基最终的pH趋于6.0;可溶性淀粉是影响松茸菌丝量的重要因子,可溶性淀粉浓度≤4g/100mL时菌丝量随可溶性淀粉浓度的增加而增大,当其浓度为4g/100mL时,菌 相似文献
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黑曲霉GD-6纤维素酶液体发酵条件的研究 总被引:7,自引:0,他引:7
采用黑曲霉 (Aspergillusniger)GD 6液体发酵生产纤维素酶 ,研究了碳源、氮源、培养基起始 pH值、接种量、摇床转速、通气量对该菌株产纤维素酶活力的影响。结果表明 ,GD 6的最适发酵温度为 2 8~ 3 0℃ ,产酶pH为 5 .5~ 6.0 ,摇床最适转速为 1 5 0r/min ,最佳接种量为 1 0 %。在以 6.0 %稻草粉为碳源、1 %豆饼粉为氮源时产酶活力最高。在最适培养条件下 ,发酵周期为 1 2 0h,发酵液中CMC酶活为 1 88.6U/mL ,FP酶活为 2 7.0U/mL。 相似文献
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营养和环境因子对长春花激素自养型细胞生长和阿玛碱生成的影响 总被引:9,自引:0,他引:9
在摇瓶中用液体培养基培养长春花(Catharanthusroseus(L.)G.Don)激素自养型细胞系C20hi,比较了不同初始糖浓度、接种量、初始pH值、光照时间、光质和摇床转速对该培养细胞生长、阿玛碱积累和释放的影响。结果表明,此细胞系具有较强的环境耐受性;一定范围内初始糖浓度增加,有利于细胞生长和生物碱生成;最适的接种量是60gFW/L;一定范围内改变培养基pH值,对生物碱生成没有显著影响;照光后生物碱生成量下降,红光较蓝光更有利于生物碱生成;最适的摇床转速是120r/min。 相似文献
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目的探讨提高海洋红酵母的液体高密度培养方法。方法在摇瓶培养条件下,测定温度、pH、装液量、接种量及摇床转速对海洋红酵母BY2菌株生长的影响,进一步放大培养至50L发酵罐,在培养过程流加氨水以控制pH稳定在5.3~5.5的条件下,考察不同葡萄糖浓度对海洋红酵母BY2菌株发酵菌量的影响。结果摇瓶最适培养条件为温度25℃,pH 5.5,接种量8%、装液量40mL/250mL三角瓶、摇床转速200r/min,在此培养条件下,24h时菌量达到8.9×108 CFU/mL;扩大至50L发酵罐,葡萄糖初始浓度为40、60、80、100g/L各罐20~24h时的菌量相应达到26.6×108、29.5×108、47.8×108、66.8×108 CFU/mL。结论提高初始葡萄糖浓度,流加氨水稳定发酵过程的pH,可以显著提高BY2菌株的发酵菌量。 相似文献
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Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis
It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis. 相似文献
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RICHARD E. NORRIS 《Botanical journal of the Linnean Society. Linnean Society of London》1991,106(1):1-40
Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera. 相似文献
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JOAN VALUÈS MONTSERRAT TORRELL NÚRIA GARCIA JACAS 《Botanical journal of the Linnean Society. Linnean Society of London》2001,137(4):399-407
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted. 相似文献
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肝癌中HBV和HCV基因和抗原的分布及意义 总被引:1,自引:0,他引:1
采用原位分子杂交方法检测HCV
RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV
RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV
RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV
X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV
C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细 相似文献
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H.-R. GREGORIUS 《Biological journal of the Linnean Society. Linnean Society of London》1984,23(2-3):157-165
For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment. 相似文献
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment. 相似文献