生物发光法微生物快速检测试剂的性质及其影响因素研究*

研究了ATP生物发光微生物快速检测试剂的反应动力学、反应最适温度、pH以及各种影响因素。在ATP生物发光反应中,测试系统中D-荧光素用量为40～50μg／mL时对反应已经足够;发光脉冲计数CPM值随反应时间的延长不断降低,开始的1min内,其CPM值下降最快,然后下降速度不断减缓;反应的最适温度为24℃-25℃;而体系的最佳pH为7．2—7．4。配制好的发光试剂溶液置于4℃保存45h,可以保持86％的活力,在25℃时保温1h,活力下降较少,随时间的增加,活力逐渐下降,到6．5h时,仅剩53．5％的活力,而     

木霉菌株T6木聚糖酶固态发酵条件和酶学性质研究

研究了碳源和氮源、起始pH、接种量及温度等条件对一野生型木霉Trichodermasp.T6菌株固态发酵产木聚糖酶的影响。在28℃培养4d后,酶活力可达1918IU／g干培养物。酶的最适反应温度为50℃,最适反应pH4．5。不同温度保温1h后,测定酶的半失活温度为47．7℃,酶的pH稳定性也进行了研究。     

ATP生物发光测定试剂研究进展

萤火虫荧光素酶是ATP生物发光试剂的关键组成部分,可通过萤火虫尾提取纯化或基因工程技术制备,酶的活力和纯度决定了ATP生物发光试剂的性能。迄今许多先进技术在ATP生物发光试剂的制备中均有应用,包括酶基因工程改造技术、ATP循环的酶法放大技术、荧光素酶蛋白的活力及发光稳定技术,特异的细胞ATP提取技术等。ATP生物发光试剂的研究焦点主要集中在提高发光试剂的检测灵敏度和性能、增加产品的适应性等方面。     

木霉菌株T6木聚糖酶固态发酵条件和酶学性质研究*

研究了碳源和氮源、起始pH、接种量及温度等条件对一野生型木霉Trichoderma sp.T6菌株固态发酵产木聚糖酶的影响。在28℃培养4d后,酶活力可达1918IU/g干培养物。酶的最适反应温度为50℃,最适反应pH4.5。不同温度保温1h后,测定酶的半失活温度为47.7℃,酶的pH稳定性也进行了研究。     

黑曲霉A3菌株木聚糖酶粗酶制剂的制备和性质

本文研究了黑曲霉（AspergillusnigerA3）菌株固体发酵培养的产酶过程,发酵3d产木聚糖酶活最高,固体曲最适浸提比为1：7（W／V）,通过60％～65％饱和度的硫酸按盐析,获得的木聚糖酶活力最高。冻干酶粉活力为15400u/g,得率为71％,40℃烘干酶粉活力为15395U／g,得率为51％,酶反应最适温度55℃,最适pH4．6,保温1h半失活温度（t1／2）为54℃,酶对四种不同底物半纤维素水解作用的亲合性为鼓皮最强,稻草最弱。     

壳聚糖固定化德氏根霉脂肪酶的研究

研究了壳聚糖吸附和戊二醛交联对脂肪酶固定化条件,在室温条件下将0．4g酶粉溶于pH6．0缓冲液中,加入10g壳聚糖,摇匀,再加入浓度为0．6％戊二醛交联6h,得到固定化酶,酶活力回收率约为54．2％。固定化酶的半失活温度比游离酶的高,半失活温度由游离酶的47℃提高到100℃,最适反应温度由40℃上升至80℃,最适pH由6下降到5．5,固定化酶K’m值由游离酶的Km 50mg／mL增加到56mg／mL。该固定化脂肪酶用于酯的合成;在80℃条件下经过10批次连续水解植物油反应,固定化酶的活力仍保持在82．6％以上。     

木霉菌株T6木聚糖酶固态发酵条件和酶学性质研究

研究了碳源和氮源、起始pH、接种量及温度等条件对一野生型木霉Trichoderma sp.T6菌株固态发酵产木聚糖酶的影响。在28℃培养4d后,酶活力可达1918IU/g干培养物。酶的最适反应温度为50℃,最适反应pH4.5。不同温度保温1h后,测定酶的半失活温度为47.7℃,酶的pH稳定性也进行了研究。     

微生物酶拆分方法生产D-泛酸的手性中间体D-泛解酸内酯

筛选到一株产D－泛解酸内酯水解酶的串珠镰孢霉菌（Fusarium moniliforme SW-902)。产酶条件研究表明,用甘油作碳源,蛋白胨作氮源,初始pH8.0,温度26℃,摇瓶培养3d,产酶量最高。在60L和1000L发酵罐中通风发酵45－47h,产酶量为6－8g干菌体／L,D－泛解酸内酯水解酶酶活力达到0．87－0．92IU／g干菌体。该酶的最适反应温度为55℃,最适反应pH为7．0－7．5。在酶不对称水解泛解酸内酯过程中,对溶液加酶量5％－10％,底物浓度10％－20％,控制水解率20％－30％,水解效果最好。     

固定化假单胞菌CTP-01细胞分解对硫磷的研究

用明胶-戊二醛(GGA)和聚丙烯酰胺(PAA)包埋的固定化Pseudomonas sp.CTP-01细胞具有降解对硫磷的特性。GGA固定化细胞水解对硫磷的活力比PAA固定化细胞高5.8倍。当保存在4℃时GGA和PAA固定化细胞分别可以保持活力31.3和70%。GGA和PAA包埋的细胞最适反应温度分别为50℃到70℃和60℃到70℃,然而整细胞在温度超过65℃时活力很快下降。GGA和PAA两种固定化细胞最适pH为8.0,当pH低于7.0时活力开始下降,pH4吋则完全失活。     

海洋真菌Asteromyces sp.TM76木聚糖酶生产初步研究

研究了海洋真菌Asteromyces sp．TM76的生长动力学和发酵产酶情况。在生长培养基中,TM76菌的最大比生长速率为1．875（1／d）,倍增时间为8．87h;TM76发酵过程中所产木聚糖酶有两个生产高峰,第7d,有最大木聚糖酶活力470．5U／mL。发酵起始pH为6．5时对产酶最佳。酶学性质研究表明该菌所产木聚糖酶的最适反应pH和温度分别为6．5和55℃,在不同温度保温1h,测定酶的半失活温度为63℃。     

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.