Microbiology of the Chicxulub Impact Crater

深层地下被认为是一个支持大量和多样化微生物生物圈的环境，但我们仍然对微生物如何在这种环境中生长，它们的空间多样性是什么，以及这种多样性如何受到地下地球化学条件的控制知之甚少。以前的研究主要集中在深海沉积物上。在这些环境中所做的工作表明，地球化学界面对确定地下生物圈的多样性很重要。关于海洋环境中的地下生物圈与大陆地下环境中的生物圈相比，人们知之甚少。我们的实验室将获取2016年4月至5月IODP 364探险期间从墨西哥湾下方6600万年历史的Chixulub撞击结构峰环收集的岩心样本。这种白垩纪末期的撞击结构被认为是导致恐龙灭绝和当时所有其他生命的~75%的原因。钻芯将通过微生物污染控制被取回到约1.5公里深。因此，钻探岩芯提供了机会来研究大陆遗址的地下微生物学，以及微生物多样性与独特但明确的地下岩性序列的关系。在这个项目中，我们建议使用这些岩芯来获得对地下微生物多样性的新见解。在这个项目中，我们将：1)量化通过岩芯的微生物生物量，并将其与岩性相关联，以了解大陆深层地下的微生物生命如何受到岩性的影响；2)具体研究微生物的丰度和多样性如何与影响岩性相关联，以了解影响如何扰乱深层地下生物圈；3)培养和使用诸如元基因组学等‘组学’方法，以了解生物的功能能力和代谢如何与环境和岩性通过岩心相关联，以更好地了解总体上，特别是在撞击坑中的深层次表层的微生物生物地球化学过程，4)使用上述数据来更全面地了解生命重新定居如何影响陨石坑，以及陨石坑如何为生命提供栖息地，尽管否则会对大型地表生物造成灾难性影响。

The deep subsurface is recognised to be an environment that supports a large and diverse microbial biosphere, and yet we still know very little about how microorganisms grow in this environment, what their spatial diversity is and how this diversity is controlled by subsurface geochemical conditions. Previous research has primarily focused on deep-ocean sediments. Work in these environments has shown that geochemical interfaces are important for determining the diversity of the subsurface biosphere. Little is known about how the subsurface biosphere in marine environments compares to that in continental subsurface environments.Our laboratory will acquire core samples collected from the peak ring of the 66 million-year old Chicxulub impact structure buried beneath the Gulf of Mexico in April-May 2016 during IODP Expedition 364. This end-Cretaceous impact structure is hypothesised to have been responsible for causing the extinction of the dinosaurs and ~75% of all other life at this time. The drill core will be retrieved with microbiological contamination control to ~1.5 km depth. Thus, the drill core offers the opportunity to investigate the subsurface microbiology of a continental site and also how the microbial diversity relates to a unique, but well-defined subsurface lithologic sequence. In this project we propose to use these cores to gain new insights into the diversity of microorganisms in the subsurface. In this project we will: 1) Quantify the biomass of microorganisms through the core and correlate it to the lithologies to understand how microbial life in the continental deep subsurface is influenced by lithology, 2) Specifically investigate how microbial abundance and diversity is correlated to impact lithologies to understand how impacts can disrupt the deep subsurface biosphere, 3) Culture and use '-omics' methods such as metagenomics to understand how the functional capabilities and metabolisms of organisms correlate to the environment and lithology through the core to gain a better understanding of microbial biogeochemical processes in the deep subsurface in general and specifically in an impact crater, 4) Use the above data to understand more generally how life recolonises impact craters and how craters might provide a habitat for life despite otherwise catastrophic effects on large surface dwelling life.