金属离子对酵母胞内核黄素产量的影响

研究了金属离子对脆壁酵母 (Saccharomycesefragilis)RY 5胞内核黄素积累的影响 ,运用均匀设计方法进行了培养基优化。结果表明 :Mg2 + ,Zn2 + ,Fe2 + 对RY 5的核黄素产量有着显著影响 ,培养基中金属离子的最佳浓度为 :MgSO4·7H2 O 1 .1g/L ;CoSO4·7H2 O 2 8mg/L ;CuSO4·5H2 O 0 .0 1mg/L ;MnCl2 0 .0 2mg/L ;ZnSO4·7H2 O 3 4mg/L ;FeSO4·7H2 O 1 4mg/L ,RY 5的核黄素产量可达 1 40mg/kg。     

球衣菌合成聚羟基烷酸(PHA)的发酵研究

研究了球衣菌 (Sphaerotilussp.)W991 3 6合成聚羟基烷酸 (PHA)的培养基配方及发酵条件。结果表明 ,W991 3 6适宜发酵培养基配方为 :葡萄糖 1 0 2 5g/L ,蛋白胨 2 6 3g/L ,MgSO4·7H2 O 0 1 7g/L ,CaCl2 0 0 5g/L ,NaH2 PO4·2H2 O 0 0 2g/L ,K2 HPO40 0 4g/L ,KH2 PO40 0 3g/L ;最佳接种量为 0 1 3 8g (干 ) / 1 0 0mL ,培养基适宜初     

青霉菌m8产胞外木聚糖酶的纯化及其性质研究

青霉菌m8产胞外木聚糖酶的适合培养基 (g/L) :含麦草粉 4 0 ,(NH4) 2 SO44.5 ,KH2 PO41.0 ,MgSO4·7H2 O 0 .5 ,NaCl 0 .3,Tween80 3.0 ,CaCO3 1.0。培养物中该酶经过离子交换和分子筛层析两步处理 ,粗酶被浓缩了 31倍 ,比活力达 4 6 7,收率为 5 0 %。该酶的最适 pH值为 4 .5 ,最适反应温度为 5 5℃ ,可被K+ ,Ca2 + ,Mg2 + 离子激活 ,而被Ag+ ,Fe3 + 和Cu2 + 离子纯化 ,其Km值为 4 .8× 10 -2 g/L。     

青霉LQ-7植酸酶产生条件研究

筛选到一株植酸酶高产菌株 ,对其进行诱变并研究了该菌株产植酸酶的最适条件。优化产酶液体培养基组成为 :3%可溶性淀粉 ,0 5 %蛋白胨 ,0 5 %NH4NO3 ,0 0 5 %MgSO4·7H2 O ,0 0 5 %FeSO4·7H2 O ,0 0 0 1%MnSO4·4H2 O ;发酵培养基的起始pH为 6 5 ,接种量 4%的条件下 30℃ ,135r min培养 72h可获得较高的植酸酶产量。少量 (2 5mg)植酸盐的加入对植酸酶有促进作用 ,但过量 (10mg以上 )时则会产生抑制作用。     

青霉菌m8产半纤维素酶条件及酶性质研究

半纤维素酶可用于造纸工业的生物制浆和废水处理。通过碳、氮源对产胞外半纤维素酶的影响确定了青霉菌m8的适宜培养基 ,即 4 .5 %麦草粉 ,0 .5 0 % (NH4 ) 2 SO4 ,0 .1%KH2 PO4 ,0 .0 5 %MgSO4 ·7H2 O ,0 .0 3%NaCl,0 .33%Tween80 ,0 .15 %CaCO3。在上述培养基中 ,2 8℃恒温振荡 (12 0r min)培养 4 - 6d ,半纤维素酶活力可达 80u ml左右。用DNS法研究了该酶的性质。结果表明 ,其最适pH值为 4 .5 ,最适反应温度为 5 5℃ ;表观Km值为 4 .6× 10 - 2 g L ;该酶的耐热性比较强 ,可被K+ 、Ca2 + 、Mg2 + 离子激活 ,而被Ag+ 、Fe3+ 和Cu2 + 离子抑制。     

用正交试验法筛选樟芝菌适宜发酵培养基

用正交试验法对樟芝菌 (AntrodiacamphorataZang&Su)的发酵培养基进行了研究。选取马铃薯淀粉、葡萄糖、麦芽糖、酵母膏、蛋白胨、麸皮、KH2 PO4 、MgSO4 ·7H2 O等作为试验因素 ,采用L2 7(31. 3)正交表设计五因素、三水平的正交试验 ,对所选各因素的添加量分别作了试验 ,对菌丝干重和发酵液多糖含量结果作了方差分析 ,确定了合适的发酵培养基。试验结果表明 :樟芝菌的深层发酵适宜培养基是 :马铃薯淀粉 1 .0 0 % ,葡萄糖2. 0 0 % ,酵母膏 0 . 10 % ,蛋白胨 0 . 10 % ,麸皮 1 .0 0 % (或 0. 5 0 % ) ,KH2 PO4 0 . 10 % ,MgSO4 ·7H2 O 0 . 0 5 %。     

雾灵山地区野生樱花的组织培养与快速繁殖

1　植物名称　樱花 (Prunusserrulata) ,又名山樱花。2　材料类别　 5月初采集河北省兴隆县雾灵山北麓的野生樱花 ,取叶腋处未见任何突起的带叶柄茎段为外植体。3　培养条件　诱导腋芽培养基 :( 1 )MS + 6 BA 2 .0mg·L- 1 (单位下同 ) +IAA 0 .5 ;( 2 )MS + 6 BA 2 .0+IAA 1 .0 ;( 3)MS + 6 BA 2 .0 +IAA 1 .5 ;( 4 )MS+ 6 BA 3.0 +IAA 0 .5 ;( 5 )MS + 6 BA 3.0 +IAA1 .0 ;( 6)MS + 6 BA 3.0 +IAA 1 .5。诱导丛生芽与芽增殖培养基 :( 7)改良MS(NH4NO3、KNO3减半 ,MgSO4·7H2 O、ZnSO4·7H2 O加倍的MS) + 6 BA …     

金针菇FV908菌株液体培养工艺的研究

通过单因子试验统计分析 ,优化筛选了适于金针菇 (Flammulinavelutipes)FV90 8的适宜培养基和摇瓶培养条件 ,结果表明 ,其适宜的液体培养基组成为玉米粉 5 .0 % ,麸皮 2 .0 % ,KH2 PO4 0 .1% ,MgSO4 ·7H2 O 0 .0 5 % ,10 μgVB1/ 10 0mL ,5 0 μgVB2 / 10 0mL ;适宜的摇瓶培养条件为 :培养基的起始pH 6 .0～ 7.0 ,5 0 0mL摇瓶装量为15 0mL ,接种量为 10 % ,培养温度 2 5℃ ,摇床转速为 12 0r/min ,菌丝干收率 39g/L。     

被孢霉菌发酵产生花生四烯酸的研究

研究了温度、培养基初始pH、碳源、氮源对被孢霉(Mortierella sp.)产生花生四烯酸的影响。正交试验结果表明,Mortierella sp.M10最佳培养基组成为(g/L):葡萄糖100,酵母膏10,KNO_3 4.0,KH_2PO_4 2.0,CaCl_2·2H_2O 0.1,MgSO_4·7H_2O 0.5,FeCl_3·6H_2O0.015,ZnSO_4·7H_2O 0.0075,CuSO_4·5H_2O 0.0005。采用最佳培养基及发酵条件,细胞干重和花生四烯酸产量分别为33.51g/L和0.827g/L。同时对摇瓶发酵过程进行了分析。     

非洲菊组织培养与快速繁殖

植物名称　非洲菊 (Ｇｅｒｂｅｒａｊａｍｅｓｏｎｉｉ) ,又名扶郎花。2　材料类别　黄色和玫瑰红色的花托。3　培养条件　以 1 / 2ＭＳ(大量元素和微量元素减半 )和ＭＳ为基本培养基。诱导培养基附加 :(1 ) 6 ＢＡ1 0ｍｇ·Ｌ-1(单位下同 ) ＮＡＡ1 .0 ,(2 ) 6 ＢＡ 7 ＮＡＡ 0 .7,(3) 6 ＢＡ 5 ＮＡＡ0 .5 ,(4) 6 ＢＡ 2 ＮＡＡ 0 .2 ;增殖培养基 :ＭＳ 6 ＢＡ 0 .1～ 0 .5 ＮＡＡ 0 .0 1～ 0 .0 5 ;生根培养基 :ＭＳ。上述培养基均为固体培养基 ,3%蔗糖、0 .4%琼脂粉 ,ｐＨ 5 .8,培养温度(2 5± 2 )℃ ,光照 1 2～ 1 4ｈ·ｄ…     

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.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

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.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

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.     

肝癌中HBV和HCV基因和抗原的分布及意义

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     

Selection with two alleles and complete dominance

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.