固定化微生物处理氨氮废水的研究进展

生物方法因其高效、持久及无二次污染已经成为治理水污染的重要方法,固定化微生物不仅加强微生物治理效果,更能保证微生物生存稳定,是现阶段生物方法治理水污染的主要组分。近年来学者们也做了很多固定化微生物处理各类废水的研究,并取得了大量优异成果。文章对固定化微生物技术进行剖析,分析各类固定化载体材料及各种固定化方法优缺点;解析利用固定化微生物处理氨氮废水效果研究及固定化微生物处理效果影响因素;综述近年来固定化微生物处理氨氮废水应用情况;最后进行总结,并提出自己的展望。     

发酵技术中新的生物催化剂—联合固定化系统

常用的固定化生物催化剂是将一种酶或一种微生物固定化,制成固定化酶或固定化细胞。近年来,德国、丹麦等科学家报道了一种新的联合固定化方法。该法是将一种微生物与另一种来源的酶固定在同一载体上,以形成联合固定化系统。目前已报道了两种联合固定化方法,一是将酶首先固定在载体上,再将微生物细胞包埋到固定酶中;二是将一种酶溶液与一种微生物混合,再经戊二醛或单宁等处理得到联合固定化物。丹麦Godtfzedson等人报道了将一种酶交联在葡聚糖凝胶上,再将不溶性的固定化葡聚     

微生物固定化技术在河流治理中的应用及研究进展

微生物在污染物去除中发挥着重要作用,但是河流自身条件会限制微生物持久有效的发挥净化功能,微生物固定化技术则可以改善这种状况,起到强化微生物处理效果的作用。分析了微生物直接用于受污染河流治理的限制因素,阐述了微生物固定化技术的高效作用机理和改进方法,并对当前该技术应用存在的问题进行分析和未来研究的方向进行展望,以期为固定化技术用于河流污染治理提供理论参考和技术借鉴。     

固定化微生物菌剂与蕹菜对中华鳖养殖污水的净化效果研究

为解决中华鳖(Trionyx sinensis)养殖所造成的水环境污染问题,研究利用海藻酸钠、沸石对复合光合菌剂和枯草芽孢杆菌菌剂分别进行固定化,并研究了不同固定化微生物菌剂与蕹菜对中华鳖养殖污水的净化效果。结果表明:净化处理15d后,利用固定化微生物菌剂与蕹菜共同处理组对中华鳖养殖污水的净化处理效果最好,养殖污水的CODMn、NH 4+-N、NO3-N、NO 2-N、PO34的去除率分别为88.7%、87.3%、90.8%、98.3%、74.9%。蕹菜处理组对于NO3-N、NO 2-N、NH 4+-N的去除率显著高于固定化复合光合菌剂处理组和固定化枯草芽孢杆菌处理组。固定化复合光合菌剂处理组对于NO3-N、NO 2-N、NH 4+-N的去除率显著高于固定化枯草芽孢杆菌菌剂处理组,但固定化枯草芽孢杆菌处理组对于污水的CODMn的去除率最高,可达90.6%。     

固定化枯草杆菌生物吸附去除水中Cd的研究

采用明胶、琼脂、海藻酸钠作为载体对枯草杆菌进行固定,通过对三种载体的包埋效果、传质性能及操作难易的比较来选择适宜的固定化载体,比较固定化微生物与游离微生物及固定化载体海藻酸钠处理含镉废水的效果,并研究温度、pH值等环境因子对固定化枯草杆菌处理含镉废水效果的影响。结果表明：海藻酸钠作为固定化载体其传质性能强、方法简便,机械强度好;固定化枯草杆菌对含镉废水去除效果明显高于游离枯草杆菌。且随着废水中Cd浓度的变化,固定化枯草杆菌处理效果存在差异,在Cd浓度为1．0mg．L^-1 ～20mg．L^-1时,Cd的去除率在24h呈现3次曲线回归,而48h以4次多项式拟合;pH值对固定化枯草杆菌处理效果产生一定影响,在pH5．0-pH7．0,随pH值升高去除效率下降,温度在20℃-30℃,固定化枯草杆菌均有较好的处理效果。     

固定化对微生物生理变化的影响

固定化微生物技术近年来得到了广泛的应用研究,然而,人们关于固定化对微生物生理特性影响方面的知识还很缺乏,文献报道不多且比较零散,严重滞后于固定化微生物的应用研究。综述了固定化对微生物生理特性方面的影响,包括固定化对微生物生长速率、对微生物活性、对有毒物质的耐受性以及对细胞中DNARNA总量变化等方面的影响。     

包埋法固定化微生物技术的载体选择

微生物技术具有处理效果理想、适用范围广泛、成本优势明显的优点。自20世纪70、80年代以来，微生物技术一直是水处理研究领域的热点，文章综述了固定化微生物载体材料的种类和特点以及琼脂、海藻酸钠、聚乙烯醇三种常用包埋载体的特点；最后对微生物固定化载体的发展方向进行了展望。     

微生物固定化处理甲醇废水的实验研究

将具有降解甲醇能力的微生物固定于颗粒活性炭,组成固定化微生物反应器,考察其对甲醇废水的处理效果,结果表明,微生物固定化生物反应器处理甲醇废水的最佳条件是ｐＨ７－８,温度２０～３０℃,空气曝 气,甲醇去除率在９０％以上。     

微生物固定化及其在环境污染治理中的应用研究进展

微生物固定化技术广泛应用于食品、轻化以及环保领域,其具有微生物密度高、生物活性好、环境适应性强、可反复利用等优点。本文对微生物固定化技术进行了概述,并通过典型案例重点阐释了其在水、土和大气等环境污染治理领域的应用进展。在水环境中,固定化载体可为不同类型微生物提供生存微环境和各自所需的生态位,提高了系统负荷和处理效能;在土壤环境中,其重要作用在于提高土壤中污染物的生物有效性,从而提升微生物修复效果;空气污染治理领域则更注重载体的机械强度及气液传质能力的提高。本文比较总结了微生物固定化技术在不同环境治理领域中的应用特点和优势,以期为今后的环境污染治理提供一定的参考。     

最新专利文摘

CN102398992A一种复合载体固定化氨氧化细菌的方法本发明公开了一种固定氨氧化细菌的方法。该法是将固定后的氨氧化细菌投放到污水中进行硝化处理,能极大地提高脱氮启动速率和氨氮去除效率。为高COD浓度废水的脱氮处理提供了良好的技术保障。所采用的复合材料和纤维状材料的固定化颗粒具有比普通固定化微生物更高的力学强度和传质性能。     

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.