Ralstonia metalliduransCH34苯酚降解特性的研究

RalstoniametalliduransCH34是从一家锌工厂的沉积物中分离筛选到的一株细菌。对其降解苯酚的特性进行了研究。结果表明R.metalliduransCH34具有很高的降解苯酚的能力,其降解苯酚的速率常数为0.33,降解苯酚的最适条件为pH7.0,温度30℃,装液量20%(v/v)。在高浓度重金属存在的条件下,R.metalliduransCH34仍保持较高的苯酚降解活力。柠檬酸钠、琥珀酸则能促进其对苯酚的降解。     

固定化Ralstonia metallidurans CH34在三相流化床中降解苯酚的研究

通过探索固定化细菌Ralstonia metallidurans CH34在三相流化反应器中降解苯酚的反应条件,对固定化细胞处理工业废水进行模拟研究,以期提高R.metallidurans CH34降解苯酚的能力和效率。结果表明,固定化R.metallidurans CH34在三相流化反应器中明显提高了降解苯酚的能力,耐抗金属性也有较大的提高,而且能够在模拟工业废水中批次培养3-4次,其降酚能力退化并不明显。这为R.metallidurans CH34实际应用提供了可靠的基础。     

固定化Ralstonia metallidurans CH34降解苯酚的研究

将既能耐抗重金属又能降解苯酚的细菌Ralstonia m etalliduransCH34固定化以提高其降酚效率。首先通过正交实验,得到了固定化该菌种的最优制备条件,然后对固定化细胞的降酚效果进行了研究。结果表明,固定化R.m etalliduransCH34的降酚效果明显优于游离细胞;抗重金属毒性方面也有较大提高;在加入额外碳源(甲苯,柠檬酸)情况下,固定化R.m etalliduransCH34进行苯酚降解时所受影响明显要小于游离态菌。     

节杆菌菌株LZP08X的分离鉴定及其降解苯酚特性

目的:从柳州市某钢铁公司焦化污水处理厂的活性污泥中,筛选分离出高效降解苯酚的菌株,对其进行分类鉴定和苯酚降解特性的研究。方法:采用苯酚为唯一碳源和能源的无机盐培养基,经过富集培养,平板分离,耐受性试验和苯酚降解能力测定。结果:获得一株能高效降解苯酚的菌株,命名为LZP08X,通过形态观察和生理生化特征分析,初步鉴定为节杆菌属(Ar-throbacter sp.)。该菌株降解苯酚的最适条件为:温度35℃,pH 9.0,装液量20%(v/v);其降解苯酚过程符合一级反应动力学方程,在苯酚初始浓度为400mg/L时,于12h内,降解率达99%,降解速率常数K值为0.39,半衰期为1.78h。结论:节杆菌属(Arthrobact-er sp.)菌株LZP08X苯酚降解能力较强,对该菌的继续研究,可使其在含酚工业废水处理的实际应用中起到重要作用。     

固定化Ralstonia metallidurans CH34降解苯酚的研究*

将既能耐抗重金属又能降解苯酚的细菌Ralstonia m etalliduransCH34固定化以提高其降酚效率。首先通过正交实验,得到了固定化该菌种的最优制备条件,然后对固定化细胞的降酚效果进行了研究。结果表明,固定化R.m etalliduransCH34的降酚效果明显优于游离细胞;抗重金属毒性方面也有较大提高;在加入额外碳源(甲苯,柠檬酸)情况下,固定化R.m etalliduransCH34进行苯酚降解时所受影响明显要小于游离态菌。     

两株苯酚降解菌的分离及降解特性的初步研究

从南昌钢铁公司焦化污水处理厂的活性污泥中分离出64株能降解苯酚的细菌,通过耐受性试验从中筛选出2株降解活性较高的苯酚降解菌,编号为F-38和F-64。研究表明:F-38和F-64都为G—菌,苯酚浓度越高,生长延滞期越长;两株菌降解苯酚基本发生在对数期,其对苯酚降解适宜条件为温度30℃,pH值8-9,通气有利于苯酚的降解。     

两株苯酚降解茵的分离及降解特性的初步研究

从南昌钢铁公司焦化污水处理厂的活性污泥中分离出64株能降解苯酚的细菌,通过耐受性试验从中筛选出2株降解活性较高的苯酚降解菌,编号为F-38和F-64。研究表明：F-38和F-64都为G-菌,苯酚浓度越高,生长延滞期越长;两株菌降解苯酚基本发生在对数期,其对苯酚降解适宜条件为温度30％,pH值8-9,通气有利于苯酚的降解。     

高效苯酚降解菌细胞固定化方法与条件的研究

含酚废水是一种难降解有机废水,对环境污染非常严重。目前常利用细菌处理含酚废水。但利用细菌处理含酚废水存在一些缺点,为此将1株高效苯酚降解菌进行细胞固定化。采用正交实验设计方法确定了该菌株固定化的最佳条件,并且考察了该固定化细胞降解苯酚的最佳条件。实验表明:该菌株的固定化细胞降解苯酚能力和耐受苯酚能力均大于游离细胞,经36 h可将1 800 mg/L苯酚降解完全。其降解苯酚的最适温度为30℃,最佳pH值为5~9。     

苯酚降解菌ZJ-1的分离及降解特性研究

目的:筛选苯酚降解菌,用于降解苯酚提高氧化塘处理效率.方法:以苯酚为惟一碳源进行选择性培养.结果:从乌鲁木齐市某炼油厂污水池的活性污泥中分离出一株能以苯酚为惟一碳源培养基上生长的菌株,编号为ZJ-1,该菌株最高可耐受1000mg/L的苯酚.对该苯酚降解菌降解性能研究表明:该菌具有较强的降解能力,在32℃、pH 7左右、接种量1%时,摇床振荡速度120r/min的条件下,该菌株在48h内苯酚降解率可达81%以上.培养液中苯酚浓度在300mg/L、500mg/L时,该菌株的降解率比较明显.当苯酚浓度大于1000mg/L时,则元明显降解效果.结论:ZJ-1菌株对苯酚具有较强的降解能力,具有广阔的应用前景.     

3-苯氧基苯甲酸降解菌Sphingomonas sp. SC-1降解苯酚环境条件及其降解中间产物的研究

【目的】探究高效降解3-苯氧基苯甲酸(3-Phenoxybenzoic acid,3-PBA)的鞘氨醇单胞菌(Sphingomonas sp.) SC-1对苯酚的降解特性。【方法】采用HPLC测定微生物降解体系中苯酚残留量,考察环境条件对菌株SC-1降解苯酚的影响;分析不同培养时间苯酚降解体系混合样品的HPLC谱图,确定其降解中间产物。【结果】菌株SC-1能在基础盐培养基中以苯酚为唯一碳源和能源生长,在初始pH 7.0、30 °C条件下,24 h可完全降解100 mg/L苯酚;Cu2+、Ba2+、Mn2+等对其降解苯酚有不同程度的抑制作用;HPLC谱图分析,初步确定邻苯二酚是菌株SC-1降解苯酚的中间产物,且该菌株可在48 h内完全降解100 mg/L邻苯二酚。【结论】菌株SC-1对苯酚及邻苯二酚均有较强的降解能力,为完善3-PBA的降解途径及污染3-PBA或含酚废水或含酚农药残留的降解提供了数据参考。     

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.