The Isolation and Characterization of Microbes from a Serpentinizing Environment

Abstract

An ancient geochemical process known as serpentinization is an environment that contains unique microbial communities and metabolisms. Serpentinization is a reaction between water and ferromagnesian minerals leading to the generation of serpentine minerals and products such as hydrogen, formate, acetate, and methane. The long history of this process along with its ability to produce sustainable energy makes serpentinization a strong candidate as a contributor to the emergence of life. While this process supplies necessary assets needed for microbial life, this process also creates extreme conditions that make life challenging for microorganisms. Serpentinizing environments present challenges such as high pH (>9), lack of inorganic carbon, and reducing conditions (low redox potential). These challenges existing in serpentinizing environments could be a major factor for metabolic influence on the evolution of microbes. Serpentinization is a widespread event occurring in a number of locations across the globe. Interestingly, recent studies using imaging technology reveal that this very exact process may in fact also occur on Mars. Many sites of serpentinization are relatively similar in their geochemical composition. However, among distinct locations, components involved and produced during serpentinization tend to vary in flux and quantity. This has been shown to have an effect on the microbial diversity and microbial abundance seen at varying sites. In this study microbes were cultivated and isolated from rock core samples extracted from the Coastal Range Ophiolite Microbial Observatory (CROMO). A genomic DNA extraction was performed to identify isolates using 16s rRNA sequencing. Metabolic and physiological assays were conducted to understand microbial response to specific environmental pressures as well as potential metabolic pathways utilized. This investigation allowed us to discover the metabolic potential of microbes representative of a serpentinizing environment. As a result, this will allow us to make more accurate projections and notions about microbial communities inhabiting serpentinizing locations and the types of metabolisms needed to navigate this type of environment.