NSF Postdoctoral Fellowship in Biology FY 2017: Survival in extreme environments through cooperation: biofilms and looking for life on Mars

Prescott Rebecca D, Kailua HI

Investigators

Abstract

This is an NSF Postdoctoral Research Fellowship in Biology for FY 2017, under the program Broadening Participation of Groups Under-represented in Biology. The fellow, Rebecca Prescott, is conducting research and receiving training that is increasing the participation of groups underrepresented in biology, under the mentorship of two sponsoring scientists: Alan Decho (University of South Carolina) and Charles Cockell (University of Edinburgh). This project investigates how biofilms (thin films of microbes attached to surfaces and encased in mucus) survive in harsh environments on Earth and under a simulated early Mars environment. This is important because determining the range of planetary conditions that are favorable for life, detecting life on other planets, and understanding how life evolved on Earth are all important questions in astrobiology. The Fellow is focusing on how biofilms from hypersaline environments may survive through cooperative behavior and chemical communication among microbe cells (referred to as quorum sensing). The fellow is also determining what genes are regulated through quorum sensing, and investigating the response to the extreme environmental conditions these microbes endure on Earth and under simulated early Martian conditions. The questions of how life evolved on Earth are imbedded in cultural traditions across the globe, and the highly interdisciplinary field of astrobiology provides unique opportunities to develop and integrate indigenous cultural perspectives into K-12 classrooms. Thus, the fellow's broadening participation activities include working with the UK Centre for Astrobiology Summer Teacher Academy, and with science teachers from the Eastern Band of Cherokee Indians, to develop teacher training workshops in culture-based science of astrobiology. To enhance our understanding of where microbial life may occur on Mars, past or present, we must understand how microbial communities evolve and function in extreme environments. Quorum sensing is an ancient and well-documented mode of cooperative living, and is a mechanism that may enhance microbial survival in extreme environments. Quorum sensing has not been investigated in an astrobiological context, and this study will be the first to illuminate possible mechanisms of microbial interactions that could increase their adaptability to early Mars conditions on the surface or subsurface. Through collaboration with the University of Edinburgh, the Fellow is using the Planetary Environmental Liquid Simulator (PELS) to evaluate the genomic, transcriptomic, and lipidomic changes of hypersaline biofilm mats from the Bahamas (surface) and biofilms from the Boulby Salt Mine, UK (subsurface) when placed in early Mars conditions in the PELS. The fellow is testing the hypothesis that through cooperative behavior (i.e. quorum sensing), biofilms have an increased chance of surviving under multiple extremes, and evaluating whether the molecules of communication may be preserved in the rock record, providing clues to a community-level response to environmental extremes.