Novel organic compounds in tephra as indicators of current and past microbial activity

GSTDTAP

项目编号	NE/R003408/1
	Novel organic compounds in tephra as indicators of current and past microbial activity
	Hayley Rachael Manners
主持机构	University of Plymouth
项目开始年	2017
	2017-12-01
项目结束日期	2018-05-31
资助机构	UK-NERC
项目类别	Research Grant
项目经费	50402(GBP)
国家	英国
语种	英语
英文摘要	The deep biosphere describes any habitat located below the surface of the continents and the bottom of the ocean, and comprises much of Earth's total living biomass. Diverse and mostly uncharacterised microorganisms live in the deep biosphere, potentially playing a role in mediating global biogeochemical processes. Understanding the origin, evolution and significance of this realm is of fundamental importance for elucidating the role of the deep biosphere in Earth's biogeochemistry and understanding how microorganisms thrive in such extreme environments, which in turn may provide insight into life elsewhere in the solar system. Due to the unknown importance the deep biosphere may play on Earth and also in the search for extra-terrestrial life, this realm has received considerable attention in research endeavours over the past three decades. Despite this, it is the most poorly understood ecosystem on Earth. The International Ocean Discovery Program (IODP) provides access to the deep biosphere. Sediment cores recovered from previous expeditions off the coast of Montserrat (Expedition 340, Site U1396) and the Aleutian Islands (Expedition 323, Site U1339) have been characterised in terms of the organic matter present throughout the sections. These sites comprise both background sediments largely derived from settling of the remains of plankton through the water column (high in carbonate at Site U1396 and silica at U1339) and volcanogenic products. The latter source arises because both sites are proximal to volcanoes, resulting in material from erupted volcanoes being rapidly transported to the oceans. Consistently, the organic material preserved in the volcanic material (termed tephra) is very different from that preserved in the background sediments. Of particular interest within the tephra are a series of amide and sulphonamide compounds (compounds with the functional group -NH2) that are either in much lower abundance or completely absent in the background sediments. These compounds have been hypothesised to originate from microbial activity occurring within the tephra. Microbial colonisation of tephra has been found at other locations where water and tephra are in contact and similar compounds have been suggested to be synthesised by various microorganisms. Unfortunately, no microbiology studies were conducted at Sites U1339 and U1396, hence the aim of this study is to further test this hypothesis at a new site off the coast of Muroto, Japan. This site has been drilled before and contains significant volumes of tephra. IODP Expedition 370 aims to drill in this region again, specifically to investigate microorganisms within the deep biosphere, making this an ideal location and time to test our hypothesis. Several questions can be addressed with this research: 1) Are there distinct novel organic compounds associated with microbiological activity over the range of temperature and other environmental factors in the sediments? 2) Does the concentration and composition of these compounds vary according to the intensity of microbial activity? If so, can we use them as a proxy measure of activity? 3) Does the concentration and composition of these compounds vary according to the sediment/porewater composition? 4) Do biomarkers persist in sediments that no longer contain microbial activity? If so, can we use them as biomarkers of past microbial activity? Expedition 370 samples will, for the first time, have well constrained profiles of depth/temperature, microbial lipids and microbial community composition. This presents the opportunity to test our hypothesis and answer the questions outlined in a robust manner, and potentially provide a new suite of biomarkers with which to look for life in extreme environments. Thus, we may be able to use these compounds as tracers of life in extreme/ancient environments such as in the search for life throughout the solar system in areas known to have experienced volcanism (e.g. Mars).
来源学科分类	Natural Environment Research
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/86917
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Hayley Rachael Manners.Novel organic compounds in tephra as indicators of current and past microbial activity.2017.