示踪全球环境变化的微生物代用指标  

AN OVERVIEW ON MICROBIAL PROXIES FOR THE RECONSTRUCTION OF PAST GLOBAL ENVIRONMENTAL CHANGE

作　　者：谢树成[1] 黄咸雨[1] 杨欢[1] 秦养民[1] 

机构地区：[1]中国地质大学(武汉)生物地质与环境地质国家重点实验室,武汉430074

出　　处：《第四纪研究》2013年第1期1-18,共18页Quaternary Sciences

基　　金：国家重点基础研究发展规划项目(973项目)(批准号:2011CB808800);国家自然科学基金重点项目(批准号:40930210)共同资助

摘　　要：文章详细总结了示踪全球环境变化的一系列微生物替代指标。重建古温度的定量指标包括藻类长链烯酮的U、古菌甘油二烷基甘油四醚化合物(GDGTs)的TEX_(86)指标、细菌GDGTs的甲基化指数(MBT)与环化指数(CBT)的组合。古温度的定性指标有脂类单体的氢同位素组成、不饱和脂肪酸的相对含量、有孔虫和硅藻的组合及其生物体的同位素组成和微量元素比值。重建古水文的指标包括有壳变形虫组合、细菌GDGTs的环化指数CBT、细菌和古菌GDGTs的陆源输入指数BIT、古菌和细菌GDGTs的相对丰度R、直链脂肪族化合物的碳优势指数CPI、好氧与厌氧微生物的丰度。古大气CO_2分压的估算可采用藻类长链烯酮的碳同位素组成、有孔虫的硼同位素组成。认为这些微生物指标在古环境重建中潜力巨大,并对一些重要微生物指标的应用原理和限定条件进行了分析。有些指标因受多种环境因子和成岩作用的影响,在应用中需特别的注意,不能无限夸大其应用领域。A series of microbial proxies for paleo-environmental conditions were overviewed. The qualitative proxies for paleo-temperature reconstruction include the Uk37 of algal alkenones, TEX86 of archaeal glycerol dialkyl glycerol tetraethers（ GDGTs）, and the combination of methylation index （MBT）with cyclisation ratio （CBT）of bacterial branched tetraethers. The quantitative proxies for paleo-temperature reconstruction are the deuterium content of specific lipid biomarkers,the relative abundance of unsaturated fatty acids,the foraminifera and diatom assemblages and the isotope compositions and the ratios of trace elements in the shells. The microbial proxies for ancient hydrological conditions include testate amoebae assemblages, CBT of bacterial GDGTs, branched and isoprenoid tetraether index（BIT）,and the abundance of total archaeal isoprenoid GDGTs relative to total bacterial branched GDGTs（ Ri/b ） ,carbon preference index（CPI） of straight chained aliphatic compounds,the abundance of aerobic and anaerobic microorganisms. Estimation of ancient atmospheric CO2 concentration could be gained through the measurement of carbon isotope composition of algal alkenones and the boron isotope composition in foraminifera. These microbial proxies for paleo-environmental reconstruction are of significant potential. The application principle and refinement are discussed in the text for some of the microbial proxies. It is emphasized that special care should be taken when some of the proxies are employed to the sediments or even sedimentary rocks due to complicated effects of multiple environmental factors.

关 键 词：地质微生物 地球生物学 全球变化 脂类 

分 类 号：P593[天文地球—地球化学] Q949.3[天文地球—地质学]