蛹虫草发酵液抗菌活性初步研究

对蛹虫草摇瓶发酵的乙酸乙酯和正丁醇萃取物进行了抗菌实验.结果表明,乙酸乙酯萃取物对细菌中的金黄色葡萄球菌、蜡状芽孢杆菌、变形杆菌、巨大芽孢杆菌、北京棒状杆菌和霉菌中的绿色木霉、黄曲霉有明显的抑菌作用;正丁醇萃取物对细菌中的马铃薯芽孢杆菌、变形杆菌、枯草芽孢杆菌、灵杆菌和霉菌中的绿色木霉以及黄曲霉有明显的抑菌作用,且提取物的抑菌作用随浓度增大而增强,而水相则没有抑菌活性.蛹虫草发酵液中具有抗菌活性物质.     

死谷芽孢杆菌对香菇栽培料中木霉菌的抑制研究

[目的]木霉是食用菌生产过程中侵染率较高的杂菌,通常使用化学药剂消杀,但这会带来农药残留问题,利用死谷芽孢杆菌防治木霉展开研究.[方法]首先确定死谷芽孢杆菌抑制木霉的成分是胞内还是胞外物质;其次有效物质经过提取,分析其理化性质的稳定性;最后研究在香菇栽培料中的初步应用效果.[结果]提取的死谷芽孢杆菌胞外分泌物属于脂肽类,能有效抑制木霉孢子萌发和菌丝生长,0.02 g/L即可达到62.8％的抑菌率,对香菇菌丝生长影响较小,且理化性质比较稳定.香菇栽培料中添加26.6％的36h死谷芽孢杆菌发酵液,对木霉菌丝抑制程度最高,防治效果较理想.[结论]死谷芽孢杆菌产生的胞外分泌物对木霉有良好的抑制作用,虽然对香菇的菌丝萌发也有一定的抑制作用,但从减少农药残留问题考虑,值得进一步研究.     

纤维素酶基因克隆及应用前景

纤维素占植物总干重的30％～50％,是地球上分布最广、含量最丰富的碳水化合物。据报道,全球每年通过光合作用产生的植物物质高达1.55×10~9吨,其中89％尚未被人类利用。我国纤维素资源也很丰富,仅农作物秸杆、皮壳一项,每年即可达数亿吨。纤维素的利用与转化对于解决前世界能源危机,粮食短缺、环境污染等问题具有重要意义。     

康氏木霉REMI突变株的差异表达蛋白分析（简报）

纤维素占植物干重的35%-50%,是地球上分布最广、含量最丰富的碳水化合物,它的利用与转化对于解决目前世界能源危机、粮食短缺、环境污染等问题具有十分重要的意义.     

混合菌发酵转化纤维素生产单细胞蛋白

纤维素是自然界中存在的最丰富的天然资源,合理开发和利用纤维素是科学家们一直致力于研究的重点领域.尽管几十年来人们在纤维素及纤维素酶的理论研究和实践应用方面均取得了较大进步,迄今尚无一种微生物或一套酶系按传统方法用于大规模降解纤维素,并取得显著经济效益[1-3].利用微生物混合发酵,可使纤维素转化为单细胞蛋白.该方面研究不仅可以解决蛋白资源短缺,解决动物饲料需求上的短缺,而且还可以提高和改善饲料中的蛋白含量和营养价值.本文就混合菌发酵转化纤维素合成单细胞蛋白的应用研究进行概述. 1 液态混合菌体系发酵纤维素合成单细胞蛋白     

改良ATMT转化技术在深绿木霉基因敲除中的应用

木霉菌是环境中具有重要经济价值的丝状真菌之一。高效率的基因敲除技术是深入研究木霉菌功能的必要手段。研究改进了传统的农杆菌介导的遗传转化技术(ATMT),成功构建深绿木霉T23中碳代谢抑制因子cre1基因敲除突变株。首先查找深绿木霉全基因组序列,比对并扩增cre1基因侧翼序列,以改造后的p1300qh质粒为骨架构建cre1敲除载体p C1300qh:cre1-up∷hyg∷cre1-down,转化到农杆菌AGL-1。通过优化ATMT转化中木霉菌分生孢子浓度,改良培养方式和延长诱导转化时间等参数,获得最佳转化条件:木霉菌分生孢子浓度为8×10~6,筛选培养基改为IM培养基,诱导转化时间延长,成功筛选到可能的转化子10个。最后,经鉴定有1个转化子为cre1敲除转化子,9个为T-DNA随机插入。因此,为深绿木霉菌基因功能研究提供了可借鉴的高效便捷的遗传转化方法。     

根癌农杆菌介导的木霉遗传转化及应用进展

木霉作为土传植物病原菌的生防真菌,研究其功能基因具有重要的意义。根癌农杆菌介导的遗传转化(ATMT)为木霉功能基因的研究提供了一个强有力的工具。对根癌农杆菌介导木霉遗传转化的机理、特点、方法及其在木霉中的应用进行了综述。     

混合菌发酵转化纤维素生产单细胞蛋白

纤维素是自然界中存在的最丰富的天然资源 ,合理开发和利用纤维素是科学家们一直致力于研究的重点领域。尽管几十年来人们在纤维素及纤维素酶的理论研究和实践应用方面均取得了较大进步 ,迄今尚无一种微生物或一套酶系按传统方法用于大规模降解纤维素 ,并取得显著经济效益[1 3] 。利用微生物混合发酵 ,可使纤维素转化为单细胞蛋白。该方面研究不仅可以解决蛋白资源短缺 ,解决动物饲料需求上的短缺 ,而且还可以提高和改善饲料中的蛋白含量和营养价值。本文就混合菌发酵转化纤维素合成单细胞蛋白的应用研究进行概述。1　液态混合菌体系发酵纤…     

里氏木霉有性生殖的分子机理及其在遗传育种中的应用

将木质纤维素转化为可发酵糖用于生产生物燃料以及生物基化学品是实现碳中和的有效途径之一.木质纤维素降解酶在这一过程中发挥着重要作用.里氏木霉是应用最为广泛的纤维素酶、半纤维素酶工业生产菌株.长期以来,里氏木霉一直被认为是红褐肉座菌的无性型,只能进行无性繁殖,菌种改良以经典诱变、基因育种等为主.直到近些年才证实里氏木霉可以...     

不同诱导方法对农杆菌介导的木霉菌遗传转化效率的影响

[目的]比较不同诱导方法对根癌农杆菌EHA105介导的哈茨木霉T88遗传转化体系转化效率的影响,以确定最佳的诱导方法.[方法]通过对复铺培养基法、转膜培养法和液体共培养法转化效率的比较来确定3种方法的优劣.[结果]复铺培养基法转化效率约为10个转化子/107个木霉孢子,转膜培养法转化效率约为20个转化子/107个木霉孢子,液体共培养法转化效率达到100个转化子/107个木霉孢子.[结论]在农杆菌介导的木霉菌遗传转化体系中,液体共培养法的转化效率最高,是常用的复铺培养基法及转膜培养法转化效率的5-10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.