芦荟凝胶中海藻糖的提取与检测

从芦荟提取多糖后的“废液”——上清液经过浓缩、脱色后冷冻干燥,得到单糖和寡糖的混合物。经质谱检测证明,该混合糖含有二糖,可能有海藻糖成分;利用高效液相色谱证实其中含有海藻糖、葡萄糖和果糖,含量比为1：62：21。该结果为芦荟强保水能力提供理论依据,而且“废液”的再利用,可以提高芦荟叶片的利用率,充分利用资源,为综合开发利用芦荟开辟一条新路。     

青霉菌胞外半纤维素酶的纯化及其性质研究

半纤维素是由己糖和戊糖组成的异质多糖,约占陆生植物干重的15％～30％,微生物产生的半纤维素酶（hendcellulas）可降解半纤维素生成木糖及其它单糖。研究半纤维素生物转化具有重要意义,如在造纸工业的生物制浆和废水处理;转化半纤维素为单糖。酒精等化工产品等。在国外已有不少有关真菌和细菌降解半纤维素的研究［‘·‘］,国内有关真菌降解半纤维素的研究工作已开始逐步展开【｝‘」,但有关青霉菌胞外半纤维素酶的产酶条件及其性质尚未见报道。本研究在优化青霉菌胞外半纤维素酶发酵条件的基础上,对粗酶液进行f初步纯化,并对其讲…     

稀有糖的生物转化生产策略：Izumoring方法

稀有糖是在自然界中存在但含量极少的一类单糖及衍生物,其在膳食、保健、医药等领域中发挥着重要的功能。本文综述了一种稀有糖的生物转化生产策略----Izumoring方法,即利用D-塔格糖3-差向异构酶、醛糖异构酶和多元醇脱氢酶等进行所有单糖及糖醇之间的相互转化;利用该原则,分别构建了己糖类、戊糖类和丁糖类的Izumoring转化策略,并可获得所有稀有糖的酶反应和生物转化生产途径。同时,展望了稀有糖生物转化生产的研究趋势。     

天然产物中的糖含量测定方法正确性的研究

通过蒽酮-硫酸法和苯酚-硫酸法,采用不同的标准单糖以及不同的单糖组成比来测定天然产物中的糖含量,得到一种比较准确性高的方法,即按多糖中单糖组成比为标准来测定。     

用减糖豆饼消化液制备单糖基础培养基的试验

1．豆饼消化液用大腸杆菌处理后糖分减少,糖氮比例降低,缓冲能力增加,可供制备单糖基础培养基之用。原料成本此蛋白腺水单糖基础培养基的成本约低一半。 2．加少量蛋白胨于未经大腸杆菌处理的豆饼消化渡中,降低其糖氮此例;同时将培养基的pH提高为7．8时,亦可用以制备单糖培养基。 3．未经大腸杆菌处理的豆饼消化液糖氮此例高,不适于制备单糖培养基。本实验由技术员楊燕玲同志协助进行,特此致谢。     

纸浆废液中有机物资源的利用

将硫酸盐纸浆废液浓缩后,100%用作生产木材胶粘剂的原料.对废液中木素进行活化处理,用酚醛树脂、PAPI增强废液胶的效果.结果表明,在废液中加入甲醛后,可提高废液中木素的反应活性;用30%甲阶酚醛树脂或20%PAPI作增强剂,可使废液混合胶代替纯酚醛树脂生产Ⅰ类胶合板;原料成本比纯酚醛树脂分别降低了55.5%和49.0%.该法充分利用了废液中的有机物资源,减少了环境污染,具有较好的经济、社会和生态效益.文中还运用红外光谱分析了废液制胶粘剂方法的可行性.     

三齿草藤(Vicia bungei Ohwi)凝集素糖组分的高效液相色谱分析

本文报道经亲和层析纯化的三齿草藤凝集素(VBL)的糖含量和糖组分的测定结果。经酚-硫酸法测得VBL的总糖含量为4.7％。应用高效液相色谱法对一系列已知标准单糖的定性定量分析条件进行了探索,选用乙腈-水-甲醇=60:30:5体系作流动相,YWG-NH_2作固定相,在高效液相色谱仪中测出VBL含有核糖和鼠李糖,二者摩尔数之比为9.4:1。     

利用肌苷发酵废液生产单细胞蛋白的研究

我国在利用微生物降解酒精废液、造纸厂废液和味精厂废液等方面已有许多报道,但是,利用肌苷发酵废液作为底物进行单细胞生产还未见报道。同时,提取肌苷后的发酵废液,其营养成份仍很丰富,其中,还原糖含量约为2％,总氮含量为300mg/L～400mg/L,以及一些无机盐。COD值高达186276mg/L。目前,一般肌苷生产厂都将废液排放掉,这不仅严重地污染了环境,而且造成很大的浪费。有鉴于此,本课题进行了菌种的筛选和驯化以及工艺方面的试验。     

透明圈法快速筛选半纤维素分解菌

半纤维素是植物性材料的重要组成成分之一 ,占 1 5 - 30 %,是陆生植物细胞壁的一种主要组分 ,较集中于初级和次级细胞壁中。半纤维素是由己糖和戊糖组成的异质多糖[1] 。微生物产生的半纤维素酶可降解半纤维素生成木糖及其它少量单糖 ,研究半纤维素生物转化具有重要意义 ,如在生物制浆 ,转化半纤维素为单糖、酒精 ,处理造纸厂废水的环境污染等方面具有广阔的应用前景 ,国外已有不少的研究者对降解半纤维素的真菌和细菌进行了研究[2 ] 。近年来 ,国内陆续出现了 7篇有关降解半纤维素真菌的研究报道 ,降解半纤维素细菌的报道只有 1篇[3 ] ,从…     

生态系统转换对土壤中碳水化合物的影响

采集贵州省茂兰喀斯特原始红楼梦 林中森林土壤和相邻农田土壤,系统分析其中碳水化合物总量和各单糖的含量。并以此来查明由森林生态系统向农业生态系统转换的过程对土壤碳水化合物的影响,结果表明：相对于森林土壤,农业土壤中碳水化合物总量明显降低。在农田土壤中六糖/五糖比值有升高的趋势,其中以M/X比值最为明显,这说明,在该转换过程中植物来源的单糖组分有所降低,微生物来源的则相对增加。     

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.