共查询到16条相似文献,搜索用时 125 毫秒
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生活在极地、深海等常年低温环境中的低温微生物和部分变温生物,能够通过产生低温酶来适应在低温环境中的生长、繁殖和代谢。这些酶在低温或常温条件下具有很高的催化活性,对热却很敏感,在高温时能够快速失活,因此在实际的生产和生活中具有广泛的应用前景。基于这些特性,低温酶的冷适应性机制研究成为了当前的一个热点。较系统地综述了低温酶的来源、特点、生产状况以及具有代表性的几种低温酶的冷适应性机制。 相似文献
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海洋覆盖了地球表面积的四分之三,它不仅是生命的起源,而且还孕育了各种极端微生物。它们存在于海洋极端环境中,如热液喷口、热泉、咸湖和深海层等,由于生境太过恶劣,一度被认为是生命的禁区。随着人类对深海极端环境微生物研究的不断深入,已经探索到那里具有丰富的菌群资源和具有潜在价值的天然生物活性产物。这些极端微生物能够适应极高温、极低温、高压、高盐、高放射性和极度酸碱性等极端环境,具有特殊的生物多样性、遗传背景和代谢途径,能够产生各种具有特殊功能的酶类及其他活性物质,展现出巨大的研究价值和应用潜力。研究海洋极端微生物对探索生物多样性、新资源开发利用及对地球生物学研究等都具有重要意义。 相似文献
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深海微生物高压适应与生物地球化学循环 总被引:3,自引:0,他引:3
深海是典型的高压环境,嗜压微生物是深海生态系统中的重要类群.随着深海采样技术的发展及高压微生物特殊培养设备的开发,已从深海环境中分离到一系列嗜压微生物,包括一些常压环境不能生长的严格嗜压菌.对这些嗜压菌的研究,不仅对微生物适应极端高压环境的机制有一定了解,而且发现了一些特殊的代谢产物.研究微生物高压嗜压机理,还有助于探索地球生命的温度压力极限及生命起源和演化等科学问题.从深海嗜压微生物多样性、深海微生物高压环境适应机理及深海微生物在生物地球化学循环中的作用等方面对嗜压微生物的研究进展进行综述. 相似文献
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低温微生物修复石油烃类污染土壤研究进展 总被引:3,自引:0,他引:3
耐冷菌、嗜冷菌等低温微生物广泛存在于极地、高山以及高纬度等土壤环境中,是石油烃类污染物在低温条件下降解与转化的重要微生物资源.利用低温微生物的独特优势,石油污染土壤的低温生物修复技术的研究成为当前热点领域.本文系统综述了低温石油烃降解菌的分类及冷适机制,低温微生物对不同类型石油烃组分的降解特征和降解机理,低温环境中接种降解菌、添加营养物质和表面活性剂等强化技术在石油污染土壤中生物修复的应用.以及微生物分子生物学技术在低温微生物降解石油烃的研究现状,为拓展我国石油污染土壤生物修复技术提供参考. 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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极地微生物产生的低温蛋白酶、色素、多不饱和脂肪酸以及抗冻蛋白等生物活性物质,不但可以使极地微生物在苛刻的环境中成功生存,而且这些生物活性物质具有潜在的工业应用价值.极地微生物能够在低温下有效降解多种烃,可以用于解决极地环境的烃类污染问题.极地微生物与天体生物学联系密切,通过极地微生物的研究可以寻找火星上生命存在的证据,进而揭示生命的起源. 相似文献
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Zoran Minic 《Symbiosis (Philadelphia, Pa.)》2009,47(3):121-132
It has been postulated that life originated in a similar environment to those of deep sea hydrothermal vents. These environments
are located along volcanic ridges and are characterized by extreme conditions such as unique physical properties (temperature,
pressure), chemical toxicity, and absence of photosynthesis. However, numerous living organisms have been discovered in these
hostile environments, including a variety of microorganisms and many animal species which live in intimate and complex symbioses
with sulfo-oxidizing and methanotrophic bacteria. Recent proteomic analyses of the endosymbiont ofRiftia pachyptila and genome sequences of some free living and symbiotic bacteria have provided complementary information about the potential
metabolic and genomic capacities of these organisms. The evolution of these adaptive strategies is connected with different
mechanisms of genetic adaptation including horizontal gene transfer and . various structural and functional mutations. Therefore,
the organisms in this environment are good models for studying the evolution of prokaryotes and eukaryotes as well as different
aspects of the biology of adaptation. This review describes some current research concerning metabolic and plausible genetic
adaptations of organisms in a deep sea environment, usingRiftia pachyptila as model. 相似文献
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Disturbance has always shaped the evolution and ecology of organisms and nowhere is this more apparent that on the iceberg gouged continental shelves of the Antarctic Peninsula (AP). The vast majority of currently described polar biodiversity occurs on the Southern Ocean shelf but current and projected climate change is rapidly altering disturbance intensities in some regions. The AP is now amongst the fastest warming and changing regions on earth. Seasonal sea ice has decreased in time and extent, most glaciers in the region have retreated, a number of ice shelves have collapsed, and the surface waters of the seas west of the AP have warmed. Here, we review the influences of disturbance from ice, sedimentation, freshening events, wave action and humans on shallow water benthic assemblages, and suggest how disturbance pressures will change during the 21st century in the West Antarctic Peninsula (WAP) and Scotia Arc region. We suggest that the intensity of ice scouring will increase in the region over the next few decades as a result of decreased winter sea ice periods and increased ice loading into coastal waters. Thus, the most frequently disturbed environment on earth will become more so, which will lead to considerable changes in community structure and species distributions. However, as ice fronts retreat past their respective grounding lines, sedimentation and freshening events will become relatively more important. Human presence in the region is increasing, through research, tourism, and resource exploitation, which represents a considerable threat to polar biodiversity over the next century. Adapting to or tolerating multiple, changing environmental stressors will be difficult for a fauna with typically slow generation turnovers that has evolved largely in isolation. We suggest that intensifying acute and chronic disturbances are likely to cause significant changes in ecosystem structure, and probably a considerable loss of polar marine biodiversity, over relatively short timescales. 相似文献
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The contamination of polar regions with mercury that is transported as inorganic mercury from lower latitudes has resulted in the accumulation of methylmercury in the food chain of polar environments, risking the health of humans and wildlife. This problem is likely to be particularly severe in coastal marine environments where active cycling occurs. Little is currently known about how mercury is methylated in polar environments. Relating observations on mercury deposition and transport through polar regions to knowledge of the microbiology of cold environments and considering the principles of mercury transformations as have been elucidated in temperate aquatic environments, we propose that in polar regions (1) variable pathways for mercury methylation may exist, (2) mercury bioavailability to microbial transformations may be enhanced, and (3) microbial niches within sea ice are sites where active microorganisms are localized in proximity to high concentrations of mercury. Thus, microbial transformations, and consequently mercury biogeochemistry, in the Arctic and Antarctic are both unique and common to these processes in lower latitudes, and understanding their dynamics is needed for the management of mercury-contaminated polar environments. 相似文献
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Breitbart M Wegley L Leeds S Schoenfeld T Rohwer F 《Applied and environmental microbiology》2004,70(3):1633-1640
In extreme thermal environments such as hot springs, phages are the only known microbial predators. Here we present the first study of prokaryotic and phage community dynamics in these environments. Phages were abundant in hot springs, reaching concentrations of a million viruses per milliliter. Hot spring phage particles were resistant to shifts to lower temperatures, possibly facilitating DNA transfer out of these extreme environments. The phages were actively produced, with a population turnover time of 1 to 2 days. Phage-mediated microbial mortality was significant, making phage lysis an important component of hot spring microbial food webs. Together, these results show that phages exert an important influence on microbial community structure and energy flow in extreme thermal environments. 相似文献
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Mya Breitbart Linda Wegley Steven Leeds Tom Schoenfeld Forest Rohwer 《Applied microbiology》2004,70(3):1633-1640
In extreme thermal environments such as hot springs, phages are the only known microbial predators. Here we present the first study of prokaryotic and phage community dynamics in these environments. Phages were abundant in hot springs, reaching concentrations of a million viruses per milliliter. Hot spring phage particles were resistant to shifts to lower temperatures, possibly facilitating DNA transfer out of these extreme environments. The phages were actively produced, with a population turnover time of 1 to 2 days. Phage-mediated microbial mortality was significant, making phage lysis an important component of hot spring microbial food webs. Together, these results show that phages exert an important influence on microbial community structure and energy flow in extreme thermal environments. 相似文献