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手性拆分环氧氯丙烷菌株的筛选、鉴定及产酶条件研究 总被引:2,自引:0,他引:2
从土壤中筛选到5株环氧化物水解酶生产菌,并通过ITS序列鉴定了其中的C375菌,结果为黑曲霉(Aspergillus nigerZJB-09103)。考察了培养基不同碳源、氮源、金属离子和pH等对产酶的影响,得到了较佳的培养基条件:淀粉16g/L,豆饼粉3g/L,蛋白胨3g/L,KH2PO4 0.4g/L,K2HPO4 0.8g/L,MgSO4 0.2g/L,ZnSO4 0.03g/L,pH6.5。采用优化后的培养基条件,酶活力达到156.1U/L,比优化前初始发酵培养条件下的酶活提高了252%,当环氧化物水解酶催化时间为10h时,(s)-环氧氯丙烷的对映体过量值(e.e.)可达99.0%。产率为18.6%。 相似文献
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目的比较羊血、马血巧克力平板痰培养流感嗜血杆菌的检出率和生长情况。方法将送检的痰标本及流感嗜血杆菌标准菌株ATCC10211分别接种于羊血、马血巧克力平板上,置烛缸中,36气培养24h,比较流感嗜血杆菌检出率及其生长情况。结果(1)2种巧克力平板痰培养流感嗜血杆菌的检出率分别为8%、34.5%。(2)标准菌株ATCC10211在马血巧克力平板上生长良好,菌落直径0.5-1.0mm,而在羊血巧克力平板上生长差,菌落大小如“沙粒”,肉眼难见。结论痰培养流感嗜血杆菌使用马血巧克力平板效果优于羊血巧克力平板。 相似文献
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木聚糖酶产生菌的选育及发酵条件研究 总被引:15,自引:2,他引:15
采用富集培养、透明圈平板筛选,从长期在其上堆放秸秆的土壤中分离到-株木聚糖酶产生菌黑曲霉C2。对该菌株进行紫外线诱变处理,然后采用自然选育的方法筛选到-株木聚糖酶高产菌株C2—56,并对该菌株的适宜发酵条件和酶学特性进行了初步研究。结果表明,C2—56三角瓶发酵酶活达656.8U/g,比出发菌株C2提高了140%;发酵条件以80%麸皮和20%玉米芯为培养基,采用3%接种量,在曲盘上发酵72h为宜,酶活达1750U/g;该菌株产生的木聚糖酶具有较差的热稳定性和较好的pH稳定性,适宜反应温度和pH分别为50℃和pH4.2。 相似文献
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植物油对虫霉菌液体培养与保存的作用 总被引:3,自引:0,他引:3
在萨氏营养液(SDB)中加入用0.1%蔗糖脂肪酸酯-15(SE15)乳化的0.50%芝麻油,可使在SDB中生长慢而结块的新蚜虫疠霉、飞虱虫疠霉和根虫瘟霉等四种虫霉的五个菌株形成均匀分散的菌丝体和能稳定转接的菌液。在SDB中加入乳化芝麻油(0.25%-1.5%)、菜籽油(0.50%-1.5%)和色拉油(80%花生油和20%菜籽油,0.75%-1.5%),能明显提高新蚜虫疠霉F98018的生物量;而在SDB中加入0.50%乳化芝麻油,可使液培菌丝产孢量增加近一倍;在SDB中加入的三种植物油(0.75%),在F98018生长4d后,含量分别下降了85%-94%,但其中脂肪酸相对组成基本不变,表明该菌生长能充分利用植物油中各脂肪酸。用萨氏培养基(SDAY)、加入0.50%乳化芝麻油的SDAY(OSSDAY)和牛奶蛋黄培养基(SEMA)培养安徽虫瘟霉F97028和新蚜虫疠霉F98028,两菌株在SEMA上生长最快;在OS-SDAY以较慢速度正常生长;而在SDAY上,两菌株或不能生长,或在第二次培养时出现明显退化。用SEMA和OS-SDAY上,两菌株或不能生长,或在第二次培养时出现明显退化。用SEMA和OS-SDAY在3℃下来保上述四种虫霉的七个菌株,在OS-SDAY上,所有菌株在9个月后仍保持活性,而在SEMA上有五个菌株死亡;同时比较F97028和F98028在用OS-SDAY保存前后的生长速度和菌落形态,无退化产生。 相似文献
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大花飞燕草的组织培养及植株再生 总被引:4,自引:1,他引:4
1植物名称大花飞燕草(Delphiniumgrandiflorum),商品名“美丽飞燕草太平洋混色”。2材料类别无菌种子苗真叶。3培养条件基本培养基为MS。(1)种子萌发培养基:1/2MS+6-BA0.sing·L(单位下同)+NAA0.2;(2)愈伤组织诱导培养基:MS十6-BAZ5十NAA0.5十IAA0.2;(S)芽分化培养基:MS+6-BA3+NAA0.3;(4)生根培养基:MS+IBA0.5。培养基(1)、(2)中添加3%蔗糖、0.3%琼脂,培养基(3)、(4)中添加3%蔗糖、0.8%琼脂,PHS.8。培养温度25士loC,光照14h·d‘,光照度1500lX。4生长与分化情况4.1… 相似文献
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绿巨人茎尖的离体培养及快速繁殖 总被引:5,自引:0,他引:5
1植物名称绿巨人(SpathiphyllumKochii)。2材料类别带顶芽茎段经表面消毒后从顶端分离出的2mm茎尖。3培养条件培养基:(1)1/2MS+6-BA0.1mg·L-1(单位下同)+IAA0.3;(2)MS+6-BA0.5+NAA0.5;(3)1/2MS+6-BA0.1+IBA0.5。以上培养基均含3%蔗糖、0.8%琼脂,pH5.8。培养温度28~30℃,照光12h·d-1,光照度2000lx。4生长与分化情况4.1茎尖的制备与培养从盆栽的生长旺盛、粗壮无病虫害的绿巨人植株上切取4cm带顶芽的茎段,除去叶片和大部分叶柄后,置烧杯中,加入1滴中性洗涤液及少量自来水,用细软的… 相似文献
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乳糖作为诱导剂对人β-防御素3蛋白表达的影响 总被引:1,自引:0,他引:1
对人β-防御素3基因工程菌株BL21-pET-hBD3的乳糖诱导条件进行了研究。乳糖浓度、诱导时间和诱导温度对菌株生长和目的蛋白表达的试验结果显示,高浓度乳糖对菌株生长有抑制作用(P〈0.01),对目的蛋白的表达无显著影响(P〉0.05),延长诱导时间对菌株生长有利(P〈0.01),但对蛋白的表达无显著影响(P〉0.05)。以0.5%乳糖在37℃诱导4h对目的蛋白的表达有利,目的蛋白的含量可达28,1%。控制好诱导条件,乳糖与IPTC的诱导效果基本相当。 相似文献
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对1株产抑菌物质的海洋真菌Caldariomyces fumago S-5的培养条件的优化进行研究,探讨该菌株的发酵产抑菌物质的性能。通过抗菌谱实验、单因素及正交实验设计研究了该菌株所产抗菌物质的押菌特征和最适发酵条件。结果表明,S-5菌株发酵液对几种G^+和G^-致病细菌具有快速的生长抑制作用,而对真菌没有明显抗菌性。发酵条件优化结果表明:菌株在葡萄糖4%、(NH4)2SO4 0.2%、KCl 0.2%、K2HPO40.2%、Fe2SO4·7H2O 0.002%、MgSO4-2H2O 0.1%、20%马铃薯浸出液的培养基中,控制发酵温度25℃,pH值5.0,接种量1-2cm。菌苔/100mL培养液,摇瓶转速240r/min条件下培养120h,发酵液中抑菌效价最高。实验结果可为该海洋微生物资源的开发利用提供依据。 相似文献
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产低温脂肪酶非极端细菌的筛选、产酶发酵及粗酶性质研究 总被引:2,自引:1,他引:1
目的:筛选产低温脂肪酶非极端细菌菌株,扩大脂肪酶的应用范围。方法:利用维多利亚蓝B平板显色法和摇瓶发酵法,从土壤中筛选产脂肪酶菌株,通过菌落形态和菌体特征观察初步对菌种进行鉴定,并对该菌株的产酶发酵培养基进行了优化。结果:得到一株产低温脂肪酶非极端细菌菌株sybc—li一1,该菌株适宜产酶培养基(%)为淀粉1、牛肉浸膏1、NaNO3 0.08、CaCl2 0.04、MgSO4 0.04、橄榄油2和OP1;初始DH8、30℃、200r/min培养72h,脂肪酶活力可高达到30.2U/mL;所产脂肪酶粗酶最适作用温度20℃,最适pH9.5,0℃时仍能保持70%的酶活性,属于低温酶;该酶与目前报道的低温脂肪酶相比,有较好的热稳定性,粗酶在pH8.5、70℃条件下保温60mla,酶活力损失30%。结论:该菌株为自然环境中筛选的非极端细菌,所产脂肪酶为低温脂肪酶,在开发应用上有良好的前景。 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