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微生物主要包括细菌、真菌、古菌、病毒等类群, 是地球上出现时间最早、分布最广泛、个体数量最多, 以及物种和基因多样性十分丰富的生物类群。为了适应各种生境, 微生物衍生出腐生、寄生、共生等多样的生存策略, 在生物地球化学循环、生态系统演替与稳定性、环境修复以及人类健康等方面发挥着重要作用。传统的微生物监测方法限制了我们对微生物多样性的认知; 但是, 近年来高通量测序技术和生物信息学的发展极大推动了微生物多样性的研究进展。本文概述了近年来在微生物多样性分布格局与维持、群落构建以及功能属性多样性的最新进展; 总结分析了细菌、古菌、真菌的多样性纬度分布格局及其驱动因子, 选择、扩散、成种、漂变等过程对细菌、古菌、真菌的群落构建的贡献, 以及细菌和真菌的形态、生理生化、生长繁殖、扩散、基因组等功能性状的多样性; 提出了未来微生物多样性研究的重要领域: 环境宏真菌组研究, 微生物多样性与生态系统多功能性的关系研究, 以及微生物互作网络的生态功能研究。 相似文献
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伊南 《基因组学与应用生物学》2010,29(2)
细菌具有强大的环境适应能力,能够在低温条件下存活.有研究表明一种名为"冷休克蛋白"的蛋白质与微生物对冷环境的适应及多种细胞功能有关,是细菌低温存活的关键,但它发挥作用的机制一直是个谜.小分子冷休克蛋白(cold shock protein.,Csps)是微生物在适应低温生长条件下,细胞诱导合成的一系列分子量为7ku左右的蛋白质.冷休克蛋白首先在大肠杆菌中被发现. 相似文献
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深海微生物多样性 总被引:1,自引:0,他引:1
海洋面积约占地球总面积的70%,平均深度3,800 m,海底平均压力38 MPa,海水以下更是包含有物理化学性质迥异的多种地质结构,例如海洋沉积物、洋壳、热液口以及冷泉等.这些性质迥异的地质结构环境造就了丰富的生物多样性,构成了地球上最大的微生物生态系统.深海海水中最主要的微生物类群是α-,γ-变形菌(Alpha-&Gammaproteobacteria),以及海洋古菌群I(Marine Group I).深海沉积物中微生物含量与有机物含量和距离大陆板块的距离相关,以异养微生物为主.深海冷泉区富集了厌氧甲烷氧化古菌ANME和硫酸盐还原菌(Deltaproteobacteria);深海热液区由于具有化学物质的多样性和快速的动态变化而导致形成微生物的高度多样性.洋壳主要由基性、超基性岩构成,含有丰富的矿物,其中不乏参与铁、锰、硫等关键代谢反应的化能自养微生物.同时,由于环境中99%以上的微生物没有已培养的亲缘种,因此对深海微生物的多样性、生理功能特性以及生物地球化学作用的理解和研究仍然存在巨大的挑战.本文将尝试从不同的深海环境分区来综述深海海水、沉积物、洋壳,以及冷泉区和热液口等特殊生态环境中微生物的分布和多样性. 相似文献
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微生物对低温极端环境适应性的研究进展 总被引:1,自引:0,他引:1
嗜冷微生物是地球寒冷环境中最主要的生物类群,并且是驱动全球生物地球化学循环的关键环节。嗜冷微生物在适应策略上显示出应对多种极端环境因素的巨大潜力,研究其适应和进化机制有助于更好地理解微生物与环境之间相互作用过程,并有效利用极端环境微生物资源。近年来,随着分子生物学和基因组学技术的高速发展,对微生物适应寒冷环境的机制及嗜冷微生物在指示气候变化和工农业应用方面均有一系列的突破。在此,本文将从基因组的GC含量、蛋白质稳定性、转录翻译调控、细胞膜流动性、渗透压调节、抗氧化损失和基因组适应性进化等方面总结当前在微生物适应低温环境机制上所取得的进展,并展望低温环境微生物在指示气候变化和工农业应用中的前景。 相似文献
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适冷微生物及其适冷机制研究进展 总被引:7,自引:0,他引:7
地球上许多生境为永久低温或季节性低温环境,适冷微生物在自然界中广泛存在。适冷微生物在环境净化、饲料、食品、奶制品、化妆品、皮革加工、洗涤等行业中具有广泛的应用前景。对适冷微生物的多样性、适冷的分子基础和适冷代谢机制进行了综述。 相似文献
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内陆土壤冷适应细菌的筛选分类与细胞膜脂肪酸的适冷机制 总被引:1,自引:0,他引:1
嗜冷菌及耐冷菌是冷适应酶及生物活性物质的重要资源。本研究从内陆土壤筛得33株冷适应细菌,包括6株革兰氏阳性菌与27株革兰氏阴性菌。通过细胞膜脂肪酸分析表明,革兰氏阳性菌的膜脂肪酸主要为分支脂肪酸,推测分支结构是阳性菌膜脂的主要适冷机制。革兰氏阴性菌呈现了不饱和、分支、短链等多样的膜脂适冷调节方式。根据脂肪酸组分的多样性,选择并鉴定了17株嗜冷及耐冷菌分布在11个属中,细胞膜脂肪酸组成的变化规律与细菌16SrRNA的进化分布高度一致。研究还表明同为不饱和脂肪酸为主的革兰氏阴性菌呈现了不同的适冷机理。相关研究不仅阐述了冷适应细菌的细胞膜脂肪酸的适应机制,而且为相关适冷酶源的开发利用提供了宝贵的资源。 相似文献
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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. 相似文献
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正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases 相似文献
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Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme
responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare
the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show
that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by
distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of
demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least
one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of
the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable
potent antiproliferative synthetic drugs. 相似文献
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RICHARD E. NORRIS 《Botanical journal of the Linnean Society. Linnean Society of London》1991,106(1):1-40
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
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JOAN VALUÈS MONTSERRAT TORRELL NÚRIA GARCIA JACAS 《Botanical journal of the Linnean Society. Linnean Society of London》2001,137(4):399-407
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