喇叭石蕊共生菌藻液体培养的研究(英文)

对喇叭石蕊共生菌、藻液体培养条件进行了研究。结果表明:共生菌生长在以40g/L肌醇为碳源、2g/LL-谷氨酰胺为氮源、起始pH值为7.0的LB液体培养基中,培养温度为20℃时表现最佳。其共生藻的生长在以160g/L葡萄糖为碳源、1.75g/LNaNO3为氮源、起始pH值为5.0的BBM液体培养基中,培养温度为20℃时表现最佳。     

内生解淀粉芽孢杆菌CC09产Iturin A摇瓶发酵条件优化

【目的】提高内生解淀粉芽孢杆菌CC09发酵产抗菌脂肽Iturin A的产量。【方法】首先采用单因子实验研究了碳源、氮源、NaCl浓度、pH、温度、转速和装液量等因子对CC09产Iturin A能力的影响,然后对其中显著性因子:氮源浓度、pH、温度及装液量4个因素进行正交实验,进一步优化发酵条件。【结果】优化培养基组成及发酵条件可以提高CC09菌株的生长速度及产Iturin A的量,其中可溶性淀粉以及一定比例的蛋白胨和酵母粉是CC09菌株产Iturin A的良好碳源和氮源;培养温度、装液量、培养液pH等也对CC09菌株产Iturin A有显著影响。优化后的培养基成分:可溶性淀粉(碳源)5 g/L、比例为3:1的胰蛋白胨酵母粉混合氮源15 g/L、NaCl 1 g/L;最佳培养条件:pH 6.0、28°C、摇床转速120 r/min、培养瓶装液量20%。【结论】在此条件下,Iturin A的产量可达到690 mg/L,较优化前的138 mg/L提高了4倍。     

紫色秃马勃的生物学特性

为研究不同培养条件对紫色秃马勃(Calvatia lilacina)菌丝生长的影响,优选出最适合其菌丝生长的条件。通过单因素试验,以菌丝的生长状态和生长速率为指标,筛选出最佳碳源、氮源、微量元素、培养温度和初始pH;再通过正交试验L_9(3~4),进一步确定最优的培养基配比组成。结果表明:最佳碳源为葡萄糖、最佳氮源为酵母粉、最佳微量元素为MgSO_4,最适合紫色秃马勃菌丝生长的培养基配方为葡萄糖浓度2%、酵母粉浓度1%、MgSO_4浓度0.1%,最适初始pH值6.5,最适培养温度30℃。通过对紫色秃马勃生物学特性的研究,得到了最适合其菌丝生长的培养条件,为紫色秃马勃的进一步研究和开发利用提供依据。     

Sulfolobus acidocaldarius ATCC 33909麦芽寡糖基海藻糖合成酶在Bacillus subtilis中的重组表达和发酵优化

为实现Sulfolobus acidocaldarius ATCC 33909来源的麦芽寡糖基海藻糖合成酶(MTSase)基因tre Y在枯草芽孢杆菌(Bacillus subtilis)中的重组表达,以质粒p ET-24a(+)-tre Y为模板PCR扩增得到目的基因,并与表达载体pHY300PLK连接,转入表达宿主Bacillus subtilis CCTCC M 2016536中,重组菌在TB培养基中培养48 h后MTSase酶活达到17.5 U/m L;在此基础上对重组菌发酵条件进行优化,通过单因素实验(氮源种类、氮源复配、氮源浓度、碳源种类、葡萄糖浓度、初始pH、诱导温度)和正交实验(氮源浓度、葡萄糖浓度、初始pH、诱导温度)确定其摇瓶发酵产酶的最适培养基和培养条件为:氮源(工业蛋白胨∶棉籽粉=3∶1)48.0 g/L、葡萄糖为10.0 g/L、培养基初始pH为7.0,最适培养温度为30℃;在此条件下,MTSase的酶活可达41.5 U/m L,是优化前的2.4倍。     

高产类胡萝卜素酵母菌株LRY-01发酵条件的优化研究

通过单因子实验研究了不同碳源、氮源、生长因子及通气量对菌株LRY-01生产类胡萝卜素的影响。实验表明,碳源、氮源、生长因子对类胡萝卜素产量的影响较大。进一步对上述因子进行了L9(34)正交实验,得到了最佳培养基配方及发酵条件:葡萄糖40g/L,(NH4)2SO41.0g/L,核黄素0.5mL/L,酵母膏0.5g/L,初始pH 4.5,摇瓶装液量为10%。菌株LRY-01在此条件下摇瓶培养72h的生物量和类胡萝卜素的产量分别可达16.19g/L和1000.06μg/g。     

正交实验优选光合细菌混合菌群产氢的最佳条件

对光合细菌混合菌群产氢影响因子进行了实验研究。通过单因素实验和正交实验, 系统考察了碳源、氮源、碳源浓度、氮源浓度、初始pH值、光照方式、接种量等因素对产氢量的影响, 实验得出最佳工艺条件为: 采用3号菌群, 碳源为葡萄糖, 碳源浓度为3 g/L, 氮源为尿素, 氮源浓度为9 g/L, 接种量为10%, pH值为8.5, 光照方式为12 h光照-12 h黑暗交替光照, 培养温度为30°C。菌种、碳源、碳源浓度、氮源是影响产氢量的重要因素。     

三种香蘑属野生食用菌菌株的培养条件优化

【背景】供试菌株分别是分离自山西省宁武县管涔山的肉色香蘑Lepista irina、斑褶香蘑L. panaeolus和山西省蒲县五鹿山的紫丁香蘑L. nuda 3种野生食用菌的子实体。【目的】获得3种野生食用菌的最佳培养条件。【方法】以菌丝生长速度为指标研究不同碳源、氮源、碳氮比、pH和培养温度等各因素对菌丝生长的影响,根据Box-Benhnken中心组合试验设计原理,采用3因素3水平的响应面法确定使菌丝体达到最快生长速度的最佳培养碳源、氮源和pH。【结果】肉色香蘑在葡萄糖20.9 g/L、土豆196.47 g/L、pH 6.0、培养温度21 °C的条件下,菌丝日均生长速度达到最大,为1.13 mm/d;斑褶香蘑在甘露醇17.4 g/L、酵母膏8.1 g/L、B族维生素0.1 g/L、K2HPO4 2.5 g/L、MgSO4 2.5 g/L、pH 7.9、培养温度25 °C的条件下,菌丝日均生长速度达到最大,为0.73 mm/d;紫丁香蘑在土豆200 g/L、可溶性淀粉20.5 g/L、KNO3 2.1 g/L、K2HPO4 2.5 g/L、MgSO4 2.5 g/L、B族维生素0.1 g/L、pH 7.0、培养温度25 °C的条件下,菌丝日均生长速度达到最大,为2.38 mm/d。【结论】获得了3种香蘑属菌株的最佳培养条件,为后续优质野生食用菌的引种驯化积累了相关数据和资源。     

华根霉产纤溶酶液体发酵条件的研究

研究了华根霉TCCC 41014产纤溶酶液态发酵的工艺条件,采用单因素实验对液态发酵培养基的碳源、氮源、初始pH值、温度和装液量进行了优化.结果表明,实验范围内华根霉TCCC41014液态发酵产纤溶酶的适宜培养基组成(g桙L):糊精80,蛋白胨60,豆粕60,初始pH为4.5.适宜培养条件:培养温度为29℃,装液量为5...     

海洋真菌岩藻多糖酶的固态发酵条件研究*

本文对海洋真菌Dendryphiella arenaria(TM94)岩藻多糖酶的固态发酵条件进行了研究,主要内容包括碳源、氮源、添加物、起始pH、接种量及温度等.固态发酵最佳培养基组成麸皮7.5g,葡萄糖0.5g,海带粉0.6g,NaNO3为4g/L最佳培养条件为培养温度28℃,起始pH6,接种量3ml(孢子浓度为106个/ml).在28℃培养24h,酶活力可达35.5IU/g干培养基,比活力为1.39IU/mg蛋白质.对岩藻多糖酶酶学性质也进行了研究.     

樟芝产生三萜类化合物的液体培养条件的响应面法优化

樟芝(Antrodia cinnamomea)是一种非褶菌目、多孔菌科的多年生蕈菌类,樟芝子实体中含有多种生理活性物质包括三萜类化合物,但野生樟芝只生长在台湾特有的牛樟树树干腐朽的心材内壁和枯死倒伏的牛樟树表面,生长极其缓慢,很难获得,价格昂贵。本研究的目的是通过液体培养樟芝的菌丝体以产生三萜类化合物,用响应面法优化了樟芝产生三萜类化合物的液体发酵条件。首先对樟芝的液体发酵的培养基成分及培养条件进行了单因素优化,研究发现樟芝液体发酵产生三萜类化合物的最佳碳源和氮源分别为葡萄糖和酵母提取物,最佳浓度分别为100 g/L和9 g/L,优化的培养基配方为(g/L):葡萄糖100.0,酵母提取物9.0,Mg SO4·7H2O 0.5,KH2PO41.0。优化的培养条件为:初始pH值6.0,温度28℃,接种量10%(v/v),摇床转速180 r/min。在此基础上,用响应面法对樟芝液体发酵产生三萜类化合物影响最大的三个因素即碳源、氮源和培养温度进行了优化,结果优化的三种因素条件为:葡萄糖104.71 g/L,酵母提取物9.93 g/L,温度28.42℃。用优化的培养条件液体培养樟芝,其三萜类化合物的产量达到391.45 mg/L,比优化前的产量223.39 mg/L提高了75.23%,为进一步研究液体培养樟芝产生三萜类化合物奠定了基础。     

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.