一个甲烷氧化菌株的分离、鉴定及其特性研究

实验室自行设计方案分离多株以甲烷为唯一碳源的菌株, 对其中的1株QJ16进行了研究, 根据该菌株形态特征与16S rDNA序列的同源性分析, 证实该菌株是一个与其最近的甲基单胞菌属各成员都不相同的菌株。对该菌株的培养条件和利用甲烷的特性进行研究结果表明, 氮源以氯化铵和硝酸钾共同作用最好, 碳源以甲烷最佳, 最佳生长温度为30℃, 最佳生长pH为6~7; 在批式实验时菌株利用甲烷的最适pH为6.5左右, 微量元素Cu2+的浓度为15 mmol/ L。     

一株甲烷氧化菌的分离鉴定与特性

甲烷氧化菌是一类能以甲烷作为唯一碳源和能源进行同化和异化代谢的微生物。从若尔盖高原不同地点采集的样品中筛选得到一株名为XN1的甲烷氧化菌,根据此菌株的形态与16SrRNA序列同源性分析,证实该菌株属于Methylomonas属。对该菌株的培养条件进行研究的结果表明,以甲烷与甲醇共同作为碳源,硝酸钾和氯化铵共同为氮源时菌生长最好,最适生长温度为25℃,最适生长pH为6.5,培养基中CuSO4·5H2O和FeSO4·7H2O的浓度以0.03mg/L和0.4mg/L为宜。     

一株甲烷利用菌的分离及其在甲烷气体测定中的应用

从山西太原晋阳湖水样中分离得到一株能以甲烷为唯一碳源生长的菌株ME16.气相色谱分析表明ME16菌株能利用甲烷.ME16菌株的16S rDNA 序列与铜绿假单胞菌(Pseudomonasaeruginosa,ATCC 10145,AF094713)相似性为99%.该菌株最适培养条件为30℃、2%接种量、25%甲烷含量和培养基pH为6.0.用电化学法研究了ME16固定化细胞体系中不同含量甲烷对溶氧的响应时间以及溶氧变化与甲烷含量的关系.结果表明,加入固定化细胞后.溶氧变化在100s内达到平衡,溶氧消耗量与通入甲烷气体含量在0～16%呈线性关系,相关系数为0.9954.对样品气体8次测量,RSD为3.34%,表明该反应体系重现性良好,为该菌株进一步研究甲烷传感器奠定基础.     

一株甲烷利用菌的分离、鉴定和性能研究

目的：研究土壤中能利用甲烷的细菌类型及特性。方法：运用传统的富集、分离、纯化方法得到1株甲烷利用菌,结果：该菌株在显微镜下呈球形,在液体培养基中生长72h后OD值可达到0.8左右,其最适生长温度30℃,最佳pH值7左右。对该菌株进行了16SrDNA扩增,测序结果表明其与Pseudoxanthomonas菌属的序列相似性为93%,其生理生化特征和分子鉴定结果表明,该菌与假黄单胞菌为不同的属。甲烷消耗气相色谱分析结论显示,120h后培养瓶中的甲烷浓度降低60%左右,说明该菌株具有较好的利用甲烷的性能。     

一株可利用甲烷的克雷伯氏菌的分离及其在甲烷检测中的应用

从山西太原水稻田土壤中,分离得到一株能以甲烷为唯一碳源和能源生长的菌株C611。通过生理生化特征及16SrDNA序列分析,该菌株初步鉴定为克雷伯氏菌(Klebsiella sp.)。采用响应面法优化了该菌株利用甲烷的培养条件,得到最佳培养条件为:温度24.4oC、接种量为6.7%、甲烷含量25%。以C611固定化细菌和溶氧响应仪为体系,采用电化学法研究了不同含量甲烷的响应时间以及溶氧变化与甲烷含量的关系。结果表明,菌株C611能利用甲烷,该反应体系对0～10%甲烷气体测定的响应时间小于100s;溶氧消耗量与通入甲烷气体含量呈线性关系,拟合系数(R2)为0.9994。以3%甲烷气体样品进行8次测量,测定平均值为3.09%,RSD为3.48%,相对误差为3%。表明该反应体系重现性良好,为该菌株进一步研究甲烷传感器奠定基础。     

甲烷利用细菌HG06的筛选鉴定及其对三种有毒物质降解的研究

通过传统微生物学方法,从广西玉林市广西玉林师范学院西校区池塘里土壤中筛选到一株甲烷利用细菌HG06,能以甲烷为惟一碳源和能源的无机培养基上生长.通过形态观察及16S rRNA编码序列同源性比较分析,该菌株初步鉴定为甲基孢囊菌.同时对HG06菌株在不同温度、pH值的生长条件进行研究,初步确定了HG06的最适生长的温度为32℃,最适pH值为7.0.TCE最高的耐受浓度为30mg/L;苯胺最高的耐受浓度为1 500mg/L;苯酚最高的耐受浓度为800mg/L.该菌在环保上有一定的应用价值.     

甲烷利用菌培养条件的优化及其初步应用

利用统计学实验设计（RSM）对能够利用甲烷的假单胞菌菌株ME16主要培养条件进行了优化。以液体无机盐和甲烷气体作为培养基分别进行了温度、接种量、甲烷含量和培养pH对细菌生长影响的研究,并在此基础上,利用响应面法分析优化了ME16菌株的主要培养条件,得到最佳培养条件为：温度29.4℃,接种量1.8%,甲烷含量25%。采用优化培养条件进行培养,细菌生物量增大0.8倍,达到稳定期的培养时间缩短了50h。该菌株初步应用于甲烷气体的脱除,脱除率达65.7 %,表明该菌株能良好的脱除空气中甲烷。     

耐低温甲烷杆菌SHB的分离鉴定与生长特性分析

利用亨盖特厌氧操作技术,从承德塞罕坝湿地污泥中分离出1株耐低温的产甲烷菌SHB。该菌株宽约0.31μm,长约2.87μm,细杆,形成长丝。能够利用H2/CO2和甲钠盐生长,不利用甲醇、三甲胺、乙酸和二级醇类。最适生长温度范围为16～40℃,最适pH为6.0～9.0,能在0%～5%盐浓度范围内生长。该菌株对青霉素、链霉素、罗红霉素、利福平、新霉素有抗性,对氯霉素、四环素、卡那霉素、庆大霉素敏感。经生理、生化及16S rDNA分析,确定该菌株与甲烷杆菌属(Methanobacterium sp.)的亲缘关系最近。该菌株的生长温度和pH范围都很宽,在沼气生产方面有潜在的应用前景。     

丙烯酶催化氧化产生环氧丙烷的研究 I.甲烷氧化菌的筛选及其特性

从甘肃玉门油田土样、油样和水样中分别筛选到具有低碳烃催化氧化活性的菌种。以甲醇为碳源培养的菌体没有丙烯酶催化氧化为环氧丙烷的活力。只有以甲烷作为唯一碳源、能源培养发酵的菌体才有高专一性的酶催化氧化活性,并对筛选到的一株具有较高活性的菌株从形态、营养和生长特征等方面进行了研究,经初步鉴定表明为甲烷氧化菌甲基单胞菌属(Methylomonas sp,)。     

一株毒死蜱降解新菌株Sphingopyxis terrae R17的分离鉴定及降解特性

从农药厂排污沟污泥中分离到一株能降解毒死蜱的新菌株,命名为R17,经生理生化和16S rDNA序列同源性分析,鉴定为Sphingopyxis terrae.R17可以利用毒死蜱作为唯一碳源生长,该菌株的最适生长温度为35℃、最适pH为7～8,在此条件下培养28 h后,菌落浓度达9.18×108cfu/mL.研究了该菌在...     

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.