Possible evidence for Arsenic metabolizing microbes in fossilized microbial mats from 2.2 billion year ago



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Project Description

Well preserved rocks from the 2.2 billion-year-old Onega Basin, NW Russia preserve evidence for microbial mats, that lived under a weakly oxgynated water column. These rocks are known to have relatively high levels of arsenic. Recent studies of modern microbes in Mono Lake and other 'extreme' environments have shown that some bacteria use oxidation/reduction reactions to get energy from arsenic compounds, and some studies have suggested that the genes involved in these metabolisms may be very ancient. In fact, given the high levels of arsenic on Early Earth, it may have been a common metabolism among some of the earliest life. Evidence for arsenic metabolism has been documented in microbial mats from 2.7 billion year old rocks from Australia; this project seeks to determine whether there is evidence for arsenic metabolism in these 2.2 billion year old rocks as well. 


Undergraduate Contribution

The student will use a light microscope to look for and photograph microbial mats in rock samples, and use the scanning electron microscope to identify the elemental composition of the mats and map the distribution of arsenic and mat-bearing and non-mat bearing rocks. 


Requirements and/or Application Instructions

Research assistants will be involved in all aspects of the project, including contributing to project code, piloting the study, providing feedback on study design, collecting data, conducting literature reviews to learn about the theoretical background of the project. RAs can also aid in data analysis.