栖热菌属高温菌RH99-02菌株产类胡萝卜素的研究

从腾冲热海分离到最高生长温度达80℃的一株嗜热非芽孢菌RH99-02菌株,经鉴定属Thermus属,对其所产类胡萝卜素进行了吸收光谱扫描及薄层层析分析。发酵研究表明振荡培养时的菌体生物量和色素产量上均高于静置培养,培养至50h菌体生物量和色素产量达到最大值,菌体色素产量为762μg/g干重。     

栖热菌属高温菌RH99-02菌株产类胡萝卜素的研究*

从腾冲热海分离到最高生长温度达 80℃的一株嗜热非芽孢菌RH99- 0 2菌株 ,经鉴定属Thermus属。对其所产类胡萝卜素进行了吸收光谱扫描及薄层层析分析。发酵研究表明振荡培养时的菌体生物量和色素产量上均高于静置培养 ,培养至 50h菌体生物量和色素产量达到最大值 ,菌体色素产量为 762 μg/g干重。     

甲型副伤寒沙门菌培养条件的优化

优化甲型副伤寒沙门菌的培养条件,提高菌体产量。方法通过单因素及正交试验,对影响甲型副伤寒沙门菌生长的培养温度、NaCl浓度和pH等条件进行优化。结果甲型副伤寒沙门菌在NaCl浓度0.75%、温度35℃、pH6.5时菌体产量最高。结论通过对甲型副伤寒沙门菌培养条件进行优化,获得较高的菌体产量,为后期诊断试剂盒的开发奠定了基础。     

优美红游动菌类胡萝卜素的提取条件研究

研究了优美红游动菌(Rhodoplanes elegans)的生长以及类胡萝卜素的产生,通过比较4种广泛采用的细胞破碎方法,对优美红游动菌(Rhodoplanes elegans)类胡萝卜素的提取条件进行了研究,结果表明:类胡萝卜素的产生与菌种的生长曲线相符合,菌种活化后培养45h,类胡萝卜素的含量趋于稳定;取此时培养液,采用超声波法破碎细胞(破碎功率640W,时间10min),类胡萝卜素提取效果最好,初提液类胡萝卜素的提取率约为7.62mg·(g干菌体)^-1;酸热法对色素的破坏严重。这为进一步开发利用天然色素资源提供了一定的理论依据。     

一株产苝醌光敏化合物的真菌成分分析

本文报道人工培养的一株菌寄生菌属Ｈｙｐｏｎｇｃｅｓｓｐ．真菌菌体化学成分的研究与分析结果,证明该菌主要次生代谢产物为醌类光敏色素,还含有较丰富的甘露醇和长链烷烃及其衍生物,是一株优良的具有实用开发价值的菌种。     

不同的底物流加方式对Alcaligenes faecalis发酵生产热凝胶的影响

目的：研究了在不同阶段、不同的底物流加方式及底物浓度对菌体生长和热凝胶合成的影响,并对粪产碱杆菌WX—C12（Alcaligenes faecalis）发酵生产热凝胶的补料工艺进行了优化。方法：15L发酵罐发酵生产热凝胶,改变培养基中氮源、碳源浓度及流加方式,测定残氮、残糖、菌体浓度及热凝胶产量的变化,确定较优的补料工艺。结果：在菌体生长阶段用氨水控制pH在7．0,可使培养基中氮源浓度维持相对稳定状态,且NH,a初始浓度较低（O．5gtL）更适合菌体生长;热凝胶合成阶段采用葡萄糖连续流加优于间歇补加培养。菌体浓度为11．9g／L时,热凝胶产量最高（72g／L）,产物得率Vp／s为78．8％;当菌体浓度再增加时,热凝胶产量反而下降。结论：确定了粪产碱杆菌发酵生产热凝胶的较优工艺条件,热凝胶产量最高为72g／L,比分批发酵28g/L增加了157％。     

高产腺苷蛋氨酸菌株的诱变选育及培养方式研究

以清酒酵母SAM-04-01为出发菌株,通过紫外线-氯化锂复合诱变的方法,来筛选高产腺苷蛋氨酸菌株。筛菌最终得到一支正突变菌株,其摇瓶产量达到1.0 g/L,比原始菌产量提高了17%。经传代培养考察,该突变菌具有良好的遗传稳定性。同时还考察了两种不同培养方式对腺苷蛋氨酸积累的影响,结果发现一次性补加L-蛋氨酸和葡萄糖溶液对菌体生长有一定的抑制作用,而在菌体达到最大浓度时开始流加前体L-蛋氨酸和葡萄糖溶液则是一种比较好的培养方式,其产量达到了5.34 g/L。     

嗜热脂肪土芽孢杆菌CHB1生长特性与培养条件研究

目的:研究嗜热脂肪土芽孢杆菌CHB1的生长特性与培养条件。方法:以菌体生长量为主要评价指标,利用单因子试验与正交试验相结合的方法对影响CHB1生长的主要因素进行分析。结果:CHB1最低和最高生长温度分别为45℃和74℃,最佳培养温度为60℃;最低和最高起始生长pH值分别为6.5和9.0,最适起始pH为8.0;菌体生长到达对数期的时间为15~18h;接种量2%,装液量40mL,转速180r/min。结论:CHB1为高温菌,生长pH范围偏碱性,条件优化后总菌体浓度可达1.1×109CFU/mL。     

一株刚果红降解菌的筛选、鉴定和性质的初步研究

通过稀释划线的方法,从土壤中分离到一株能降解刚果红的菌株(T1),从菌落和孢子形态来判断该菌为放线菌的链霉菌属。T1菌在含刚果红(100 mg.L-1)高氏液体培养基中培养6 d后,脱色率高达90%。对培养液进行200~800 nm波长扫描的结果表明,培养基中部分刚果红被T1菌降解,其余部分被菌体吸附。活菌体对染料的吸附效率比死菌体高。T1菌对刚果红的脱色主要是通过生物降解和菌体吸附作用来完成。     

假蜜环菌液体深层发酵条件的研究

对该真菌菌丝体的液体深层培养条件进行了探讨为进一步工业化发酵提供参考数据。方法：在基本培养基的基础上分别改变碳源、氮源、无机元素和C／N比对该菌的液体深层发酵情况,包括测量各培养条件下耗糖情况、绘制生长曲线,观察菌体的生长形态等等。结果：假蜜环菌的菌丝产量在第6d可达到最大值,其后会逐渐降低,并伴有溶菌的现象发生。在培养初期加入微量钴元素有利于刺激糖代谢提高菌体对糖的利用率,其作用主要是缩短延滞期。进入指数生长期后连续补加碳源有利于菌体迅速生长。优化后培养基组成为：葡萄糖l％和蔗糖1％为碳源,以酵母浸膏l％为氮源,KH2PO4 0．1％,MgSO4 0．05％Z,元素钴适量。液体深层发酵培养6d后菌丝生长状态已达到最佳,在此条件下搅拌发酵培养可收获20mg/ml(干重)的菌丝体。     

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.