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1.
野油菜黄单胞菌(Xanthomonascampestris)L4在两吨发酵罐中,以蔗糖为底物发酵72h,发酵液粘度达到6000~12000cp,转化率平均达到62.45%。  相似文献   

2.
以大麦芽、大麦和大米为主料,优质红茶为辅料,依据微生物生理代谢与生态的基本原理,选择了三个菌种混合发酵,开发了一种新型发酵无醇饮料。采用的三个菌种是:酵母菌(Saccharomycescerivisiae),嗜酸乳酸菌(Lactobacillusacidophilus),弱氧化醋酸单胞菌(Acetomonassuboxydans)。将上述菌种按一定比例(1:1:2)接种,接种总量为发酵基质的10%,控制发酵温度20-25℃,发酵时间5天,即可制成风格独特、口味纯正的新型发酵无醇饮料(含醇量<1%)。  相似文献   

3.
以大麦芽、大麦和大米为主料,优质红茶为辅料,依据微生物生理代谢与生态的基本原理,选择了三个菌种混合发酵,开发了一种新型发酵无醇饮料。采用的三个菌种是:酵母菌(Saccharomycescerivisiae),嗜酸乳酸菌(Lactobacillusacidophilus),弱氧化醋酸单胞菌(Acetomonassuboxydans)。将上述菌种按一定比例(1:1:2)接种,接种总量为发酵基质的10%,控制发酵温度20-25℃,发酵时间5天,即可制成风格独特、口味纯正  相似文献   

4.
野油菜黄单胞菌(Xanthomonascampestris)L4在20t发酵罐中,以蔗糖为底物发酵72h,发酵液粘度达到7000~9500cp,产物对底物的转化率平均达到61.6%,为投产奠定了良好的基础。  相似文献   

5.
点状产气单胞菌脯氨酰内肽酶基因克隆与序列测定   总被引:2,自引:0,他引:2  
点状产气单胞菌点状亚种(Aeromonas puncata subsp.punctata)具有脯氨酰内肽酶(prolyl endopeptidase PEP)活性。将其染色体DNA有Eco RⅠ部分酶切后回收8-16kb的DNA片段,与EcoRⅠ消化载体pUC18连接后转化E.coil DH5α,用该酶的专一性底物Benzyloxycarbonyl-Gly-β-naphthylamide从质粒库中  相似文献   

6.
磨盘柿天然发酵制醋的真菌区系鉴定和毒素分析   总被引:2,自引:0,他引:2  
北京地区天然发酵柿醋的真菌区系主要分布在发酵醪表层,10cm以下直菌发生较少。主要发生的真菌有4种:Aspergillus parasiticus发生频率为4.8%;Penicilium canesens发生频率为42.8%;Penicilium expansum发生频率为38.1%;P.crustosum发生频率为14.2%。虽然发现有产毒菌株,但未检测到有黄典霉毒素。所以天然发酵柿醋是符合食品卫生标准的。  相似文献   

7.
本文报道野油菜黄单胞菌(Xanthomonas campcstris)L4以蔗糖为底物在2吨发酵罐中生产的胞外多糖的理化分析结果,并与美国的商品黄单胞菌多糖(Xanthan)相比较。两种多糖纯化后单糖组分的气相色谱分析表明,它们均含有D-葡萄糖和D-甘露糖,克分子比为1:1。糖醛酸含量相同,为19%。 L4多糖和Xanthan的丙酮酸含量也相当,分别为4.23%和4.66%,元素分析和红外光谱分析表明,它们有相似的元素组成和基团吸收。L4多糖的沉降系数S02。W为11.5-11.9 S,比美国商品高(10.10S)。L4多糖的持性粘度[η]=11.8dl/g,偏比容-v=0.55ml/g,分子量为2 2 25 600—378 3000。  相似文献   

8.
两种过路黄的核型研究   总被引:1,自引:0,他引:1  
周筱玲  廖亮  陈晔  徐玲玲   《广西植物》1999,19(3):236-238
对国产报春花科(Primulaceae)珍珠菜属(Lysimachia)植物过路黄(L.christinaeHance)和疏节过路黄(L.remotaPetitm)的核型进行了首次报道。过路黄染色体数目为2n=24,核型公式为2n=24=2m+4sm+6st+12t,核型类型“3A”;疏节过路黄染色体数目为2n=22,核型公式为2n=22=4m+6sm+2st+10t,核型类型“3A”。  相似文献   

9.
郑月慧  吴绮明 《动物学报》1999,45(2):194-199
采用离体孵育大鼠黄体细胞的方法,观察了反义c-fos寡脱氧核苷酸(反义c-fosODN)对hCG诱导的黄体细胞孕酮(P)和雌二醇(E2)产生的影响,同时观察了外源性cAMP和钙离子通道阻断剂维拉帕米对黄体细胞中c-fos蛋白的影响。结果发现,反义c-fosODN能呈剂量相关方式抑制hCG诱导的黄体细胞P和E2的产生,同时使c-fos蛋白染色阳性的黄体细胞百分数下降;而无义tat ODN没有相应的作  相似文献   

10.
响应面法优化赖氨酸发酵培养基   总被引:5,自引:0,他引:5  
宫衡  李小明 《生物技术》1995,5(4):13-15
运用Box-Behken设计的响应面试验(Response-surface experiment)对黄色短杆菌(Breuibacterium flauum)FB42进行赖氨酸发酵的培养基进行了优化。响应面法对72小时分批发酵结果的优化分析表明:硫酸铵、豆饼水解液及玉米浆三种因素对赖氨醚发酵无明显的交互作用,在硫酸铵、豆饼水解液和玉米浆的浓度分别为5%、2%和3%时,发酵液中的产酸达到54.06g/  相似文献   

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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.  相似文献   

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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.  相似文献   

18.
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.  相似文献   

19.
肝癌中HBV和HCV基因和抗原的分布及意义   总被引:1,自引:0,他引:1  
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  相似文献   

20.
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.  相似文献   

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