Past, Present, and Future: Microbial Mats as Models for Astrobiological Research

Abstract

Modern microbial mats have long served as tractable model systems for the emerging field of astrobiology. Whether it be the exploration of past, present, or even future ecosystems on Earth and beyond, microbial mats are ideal model communities for fundamental astrobiological research as they can be experimentally manipulated under in situ, in vitro, and in silico conditions. In this chapter, we discuss those microbial mat systems that lend themselves to experimental manipulation under natural and artificial growth conditions. We discuss the role that microbial mat models have played in the search for chemical biosignatures that may ultimately provide diagnostic tools for screening the geologic record of ancient Earth, Mars, or other putative locales for life. We also discuss the role of microbial mats in the evolution of global climate and their potential role as indicators and tools for the present and future regulation of Earth’s climate. Finally, we examine the use of microbial mat ecosystems to elucidate the molecular infrastructure of modern microbial consortia using metagenomic approaches. By understanding the cell-to-cell interactions within microbial consortia at the molecular level, the underlying genetic and biochemical mechanisms needed for the initiation, maintenance, and possibly the evolution of microbial mats can be delineated.