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.
Biodiversity of deep-sea microorganisms
The oceans,with an average depth of 3,800 meters and an average pressure about 38 MPa,cover about 70％ of the surface of the Earth.Geological structures under the seawater,such as marine sediments,oceanic crust,hydrothermal vents,and the cold seeps,vary significantly with regard to physical and chemical properties.In combination,these diverse environments contain the largest microbial ecosystem in the world.In deep seawater,the major microorganism groups are Alpha-& Gammaproteobacteria,and Marine Group I.In deep-sea sediments,the abundance of microbes is related to the content of organic matter and distance from land.Methane Oxidizing Archaea (ANME) and sulfate reducing bacteria (Deltaproteobacteria) are common in deep-sea cold seep environments; while in hydrothermal vents,the richness and dynamics of chemical substances have led to highly diversified archaeal and bacterial groups.In contrast,the oceanic crust is mainly composed of basic and ultrabasic rocks rich in minerals,and as a result houses microorganisms that are mainly autotrophic,utilizing iron,manganese and sulfur.Because more than 99％ of deep-sea microorganisms cannot be cultured,an understanding of their diversity,physiological features,and biogeochemical roles remains to be fully achieved.In this article,we review and summarize what is known about the distribution and diversity of deep-sea microorganisms in diverse habitats.It is emphasized that there is much to learn about these microbes.
NETL
NSTL
万方数据
维普
