四种羊肚菌在固体发酵条件下的菌丝生物量和降解淀粉作用

本文对4种羊肚菌在固体发酵条件下的菌丝生物量和降解淀粉作用进行了研究,结果表明：羊肚菌(Morchella esculenta)、尖顶羊肚菌(M conica)、黑脉羊肚菌(M angusticeps)和皱柄羊肚菌(M. crassipes)在玉米粉培养基或马铃薯粉培养基上进行固体发酵时,菌丝生物量之间无显著差异;但a-淀粉酶活力、淀粉降解率差异显著。4种羊肚菌中,尖顶羊肚菌的降解淀粉能力最强。在培养基中添加Ca²⁺和氮源以及将发酵时间从15天延长到25天均能显著提高羊肚菌的菌丝生物量、a-淀粉酶活力和淀粉降解率。在添加10％黄豆粉、0.1％Ca(Cl)₂25℃发酵25天的玉米粉和马铃薯粉的发酵产物中,尖顶羊肚菌对玉米淀粉的降解率可达到74.2％,对马铃薯淀粉的降解率可达到79.8％。     

提高豆渣固态发酵核黄素产率的研究

在豆渣固态发酵生产核黄素工艺基础上,研究了改变液体种子和固体发酵培养基成分对阿舒假囊酵母菌核黄素产率的影响。结果表明,发酵培养基中添加１０％麦麸或２％小米可使核黄素产率分别提高２５％或１４％,添加２５μｍｏｌ／Ｌ碘乙酸则比对照组核黄素产率提高６．２─１０．４％。正交实验表明,接种量５％,并添加１０％麦麸、２％小米、１％玉米浆和２５μｍｏｌ／ｋｇ碘乙酸可使核黄素的产率最高达到６．１４ｍｇ／ｇ基料,蛋白质含量由１０．２％提高到１５．８％．     

苏云金杆菌33菌株最佳培养基和发酵条件研究

应用正交试验L27(313)对鳞翅目昆虫高毒效的苏云金杆菌33菌株的发酵培养基进行研究,得到了适合其发酵培养的优化复合培养基配方—0.5％玉米粉 2．00％黄豆粉 0．15％酵母粉 0．25％鱼粉 0．075％蛋白胨 0．25％磷酸二氢钾 0．05％碳酸钙 0．035％硫酸镁。另外实验还证实适当增加通气量、发酵初始酸碱度控制在pH7．5、发酵温度30℃、转速180r／min、培养40h更适合该菌株液体深层发酵。     

白僵菌固态发酵试验研究

以产孢量为指标,筛选出白僵菌固态发酵的培养基为：90％麦麸＋5％玉米粉＋5％黄豆粉,原孢粉的产孢量可达244．7亿／g。在25m^3发酵罐内进行浅盘固态发酵,培养基的最适起始含水率为60％～65％;最佳通气条件为：前12h不通气,12～48h通气量为1：2,48～144h的通气量为1：1;而温度只需在12～48＋8h内进行控制。常温干燥能最大限度地维持白僵菌的活孢率。     

解淀粉芽孢杆菌3-2发酵羽毛产氨基酸

【目的】建立废弃羽毛液体发酵工艺,优化发酵条件,提高羽毛降解率及氨基酸产量,研发新型、高效复合氨基酸肥料。【方法】利用解淀粉芽孢杆菌3-2发酵羽毛,探究温度、发酵时间、羽毛含量、单一碳源、复合碳氮源、金属离子等对废弃羽毛降解效果以及发酵液中氨基酸种类和含量的影响。【结果】废弃羽毛降解率与氨基酸总产量呈负相关。随着发酵时间延长,羽毛降解率增加,当发酵温度为37°C、羽毛添加量为1%、以乳糖为外加碳源、添加Mg2+时,羽毛降解率最高,达到81.92%。随着羽毛添加量增加,氨基酸总含量也增加(在20%范围以内),当发酵温度为37°C、降解时间为108 h、羽毛添加量为10%、乳糖添加量为0.5%、不添加复合碳氮源、不添加金属离子时,氨基酸的种类最全(富含17种氨基酸),总含量最高,达到20.861 g/kg。【结论】利用解淀粉芽孢杆菌3-2发酵废弃羽毛生产氨基酸复合肥料是一种可靠、环保、经济的方法,获得的氨基酸肥料营养齐全。研究结果为新型复合氨基酸肥料的研发提供技术支撑。     

花生四烯酸高产突变株的选育及其发酵调控

以拉曼被孢霉（Mortierellaramanniana）SM541为原始菌株,经过紫外线复合氯化锂诱变处理,得到突变株SM541－9,其生物量由126g／L提高到28．8g／L,油脂含量由5．8g／L提高到15.7g／L。花生四烯酸含量由321mg／L增加到623mg／L。传代实验表明,SM541－9具有良好的遗传稳定性,以葡萄糖为碳源,硝酸钾为氮源的最适培养条件下,10L罐发酵,生物量和花生四烯酸含量较原始菌株分别提高了45．2％和109.5％。在液体发酵过程中,菌丝老化、增大溶氧量、间歇流加葡萄糖都有利于花生四烯酸的合成。     

利用多菌种混合发酵降解饼粕中粗蛋白的实验研究

对凝结芽孢杆菌、圆孢芽孢杆菌、短小芽孢杆菌和球形芽孢杆菌在菜籽饼粕中混合发酵降低其大分子粗蛋白含量提高游离氨基酸含量的发酵工艺进行了研究。结果表明其最佳发酵工艺条件：4种菌种接种量比例为(1：1：3：1),含水量60％,接种量15％,发酵25d,粗蛋白降解率达41．98％,游离氨基酸含量提高10．18倍。为工业上生产菌肥提供了理论基础。     

球孢白僵菌固态罐发酵产孢培养的研究

建立了一套两升圆柱体玻璃发酵罐的固态通风培养装置及通风系统。以球孢白僵菌Bb371为生产菌,培养基220g(82％麸皮 4．5％黄豆粉 4．5％玉米粉 9％稻壳)作为生产原料,接种30ml,23℃培养温度下,分阶段调节通风量和空气湿度,培养5d,产孢量可达到116亿／g干培养基。     

耐高温菌的分离及在固态发酵上部烟叶中的应用

从上部低次烟叶中筛选出耐高温淀粉酶产生菌GW-2和耐高温蛋白酶产生菌GW-3,通过对菌落的形态观察、16S rRNA的鉴定和同源性分析,初步确定GW-2为解淀粉芽胞杆菌,GW-3为枯草芽胞杆菌。对上部低次烟叶进行双菌种固态发酵,并优化发酵条件,最佳发酵条件:GW-2菌悬液(OD600=1)接种量为7.5 m L/g,GW-3菌悬液(OD600=1)接种量为10 m L/g,物料填充度为500 m L三角瓶中装50 g烟叶干基,当烟叶发酵水分质量分数为45%时,48℃发酵5 d。在该发酵条件下,上部低次烟叶的淀粉降解率为22.33%,蛋白质降解率为16.74%。烟叶淀粉和蛋白质的质量分数较大幅度下降,其含量指标接近优等烟叶的含量。该发酵方式比传统的贮存式烟叶发酵大大缩短了发酵时间。     

提高蛋白激发子产量的培养基及发酵条件的优化

为了进一步提高极细链格孢菌产蛋白激发子的产量,通过单因子和多因子试验与分析,筛选优化了适于极细链格孢菌产生蛋白激发子的培养基和培养条件,并检测了发酵过程中pH、还原糖、氨基氮和菌丝量变化以及与蛋白激发子产量的关系。结果表明,土豆淀粉和黄豆粉对蛋白激发子产量影响最大,其次是蛋白胨和无机盐。优化的发酵培养基主要成分（g／L）：碳源I 15、葡萄糖5、玉米淀粉5、土豆淀粉20、谷氨酸10、氮源I5、黄豆粉10、硫酸铵5。确定了优化的培养条件,调整培养基起始pH为7．0～7．5,将18h菌龄的种子培养液按10％接种量接种到装液量为75mL的500mL摇瓶中,在温度（28±1）℃、摇床转速180r／min下培养可获得理想的蛋白产量。在优化的培养基和培养条件下,发酵12～48h该菌进入对数生长期,48h进入稳定生长期,60h菌丝扣蛋白激发子产量达最高。蛋白产量与菌体生物量呈正相关,当还原糖、总糖量消耗到最低水平时,菌丝产量和蛋白激发子产量达最高。优化的培养基菌丝干重收率迭3．9g／100mL,蛋白激发子产量达到5．17g／L,比普通的土豆液体培养基提高近4倍。     

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.