曲霉木聚糖酶发酵条件与性质

从实验室培养污染物上分离出一株产木聚糖酶活力高的曲霉（ＡｓｐｅｒｇｉｌｌｕｓＳｐ．）Ａ３菌株。研究了其发酵过程,该菌经３０℃,培养９６小时,酶活力可达３２０ＩＵ／ｍｌ,研究了碳源,氮源,发酵起始ｐＨ值及通风量对产酶的影响。酶的最适反应温度为５５℃,最适ｐＨ值为４．４。在不同温度下保温１小时,测得该酶的半失活温度为５１℃。     

木霉T6木聚糖酶制剂研究

本文研究了木霉Ｔ６（Ｔｒｉｃｈｏｄｅｒｍａ ｓｐ．）产木聚糖酶固态发酵过程和木聚糖酶制剂制备,结果显示,固体曲培养４ｄ时酶活力最高,固体曲最适液固浸提比为７：１。木聚糖酶在６０～６５％硫酸铵饱和度下盐析效果最好。冷冻干燥和４０℃烘干酶粉得率分别为６８．３％和４５．７％。酶最适反应ＰＨ为４．５,最适反应温度５０℃,在不同温度下１小时后的半失活温度为４７．７℃。     

无花果蛋白酶在阴离子交换树脂上的固定化

无花果蛋白酶通过８％戊二醛活化载体,共价结合到聚苯乙烯阴离子交换树脂ＧＭ２０１上,固定化作用在ｐＨ７．７,酶浓度０．８ｍｇ／ｇ树脂,４℃下进行６ｈ。得到的固定化酶表观Ｋ_ｍ值（酪蛋白,１．１１×１０~（－４）ｍｏｌ／Ｌ）小于溶液酶Ｋ_ｍ值（１．９６×１０~（－４）ｍｏｌ／Ｌ）;固定化酶活性在ｐＨ６～８保持稳定,溶液酶最适ｐＨ为７．２;固定化酶最适温度由溶液酶的５０～６０℃移至３７℃;固定化酶２５℃保持７ｄ,重复水解酪蛋白７次后,保留８３．３％活性。固定化酶对酪蛋白水解度达４７．５％,对大豆球蛋白达１１．６％。     

彩绒革盖菌漆酶及多酚氧化酶活性研究

测定了彩绒革盖菌在ＰＤＹ液体培养基中的漆酶和多酚氧化酶活性。在３０℃,１１０ｒ／ｍｉｎ,恒温振荡培养条件下,漆酶第９ｄ达产酶高峰,最高酶活３９５．６ｕ;多酚氧化酶第１４ｄ达产酶高峰,峰值５４９．０ｕ;酶作用的最适酸碱度为：漆酶ｐＨ４．６,多酚氧化酶ｐＨ５．０;最适作用温度漆酶为２５℃,多酚氧化酶为３０℃;Ｋ＾＋、Ｚｎ＾２＋等离子对漆酶有激活作用,Ｍｎ＾２＋、Ｂａ＾２＋、Ｍｇ＾２＋等离子对多酚氧化酶     

黑曲霉（Aspergillus niger）纤维素酶系中内切β—葡聚糖酶性质的研究

对黑曲霉菌株Ｗ２５纤维素酶系中内切β－萄聚糖酶组分的性质进行了研究。Ⅰ－２ａ,Ⅰ－２ｂ,Ⅰ－２ｃ,Ⅰ－２ｄ,Ⅱａ,Ⅱｂ,和Ⅲａ的最适ｐＨ分别为５．５,５．５,５．０,５．５,５．０,５．５和５．５;均在ｐＨ２．０－７．０之间稳定,最适温度分别为５０,５０,５５,５５,５５和６０℃;保温１小时的半失活温度ｔ１／２分别为４９、６１、６３、５２、５７、４７和６７℃。ＳＤＳ－凝胶电脉法测得Ⅰ－２ａ,Ⅰ－２     

适于非水相催化用细菌脂肪酶基本性质的研究

对假单胞菌产脂肪酶的基本酶学性质进行了研究．该酶水解油脂时的最适作用ｐＨ为９．０,最适作用温度为４５℃;在ｐＨ７．０～１０．０范围内稳定,在６０℃以下热稳定性良好．Ｋ＋、Ｃａ２＋、Ｍｇ２＋等金属离子对酶有明显的激活作用,而Ｈｇ２＋、Ｃｕ２＋、Ｓｎ２＋等重金属离子却对酶有较强的抑制作用;几种表面活性剂和胆汁盐均使酶发生不同程度的失活．该酶在水解油脂时表现出１,３－位置专一性,且对不同种类和来源的油脂水解作用速率不同     

吖啶橙失活处理应用于不对称融合初步探讨

马铃薯栽培种和野生种叶肉原生质体经过吖啶橙（ＡＯ）处理后,暗培养两天,再光照４ｈ而失活．失活程度取决于ＡＯ处理时间、ＡＯ浓度、光照时机等．四倍体失活浓度高于二倍体,处理后马上光照失活效果最强烈,８ｄ后光照其小细胞团同未光照处理相差不大。ＡＯ失活的栽培种ＮＯ７同罗丹明６Ｇ（Ｒ６Ｇ）失活的Ｓｏｌａｎｕｍｂｕｌｂｏｃａｓｔａｎｕｍ融合后可以发生代谢互补恢复分裂,已得到假定的杂种小愈伤组织．     

空肠弯曲菌肠毒素理化特性的研究

经ＳＤＳＰＡＧＥ 分析发现,空肠弯曲菌细胞紧张性肠毒素（Ｃｙｔｏｔｏｎｉｃ ｅｎｔｅｒｏｔｏｘｉｎ ,ＣＥ） 的硫酸胺盐析粗提物除有一条６８ｋＤ 的带外,还有一些未分开的小分子物质,而经神经节苷脂ＧＭ１ 亲和层析后仅有６８ＫＤ 的一条带,即表明６８ｋＤ 的蛋白质为ＣＥ 的主要成分。ＣＥ 不耐热、ｐＨ 依赖和对胰酶有抗性。５６ ℃和６０ ℃加热３０ｍｉｎ 、１００ ℃加热１５ｍｉｎ 即可完全失活。其活性在ｐＨ６－０ 时最高,在ｐＨ３－０ 和９－０ 时均可使其完全丧失活性。在４ ℃保存超过３ｄ 后,其活性迅速降低。抗ＬＴ 血清能完全抑制ＣＥ 的活性。     

玉米秸秆酶水解正交试验的研究

经蒸汽爆破预处理的玉米秸杆用里氏木霉（Ｔｒｉｃｈｏｄｅｒｍａ ｒｅｅｓｅｉ Ｒｕｔ Ｃ３０）制备的纤维素酶进行水解,其影响因素主要为ｐＨ值、温度、微量元素,考虑了上述三因素对酶解的影响,以酶解得率为指标来评价酶水解效果,设计了三因素三水平正交实验。研究表明,酶最佳工艺条件为：ｐＨ＝４．８,温度４５℃,微量元素０．５ｍｌ。     

角质蛋白酶固态发酵工艺及酶解条件的研究

曲霉Ａ２８－８是一株优良的角蛋白酶分泌突变菌株。其最佳固体发酵培养基为：２０％羽毛粉,８０％麸皮和微量无机氮（每克培养基中加０．５ｍｇ）;最适产酶条件为：起始ｐＨ７．５～８．０,温度２８℃～３０℃,时间为６０～７０小时,酶活高达２５００ＫＵ／ｇ曲;最适酶解条件为ｐＨ７．０～９．０,温度４５℃～５０℃。     

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.