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Archaea
Volume 2012, Article ID 789278, 12 pages
http://dx.doi.org/10.1155/2012/789278
Research Article

A First Analysis of Metallome Biosignatures of Hyperthermophilic Archaea

1Department of Geosciences and Penn State Astrobiology Research Center, The Pennsylvania State University, University Park, PA 16802, USA
2School of Earth Sciences, University of Bristol, Bristol BS8 1RJ, UK

Received 12 July 2012; Revised 27 September 2012; Accepted 29 September 2012

Academic Editor: Antoine Danchin

Copyright © 2012 Vyllinniskii Cameron et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

To date, no experimental data has been reported for the metallome of hyperthermophilic microorganisms although their metal requirements for growth are known to be unique. Here, experiments were conducted to determine (i) cellular trace metal concentrations of the hyperthermophilic Archaea Methanococcus jannaschii and Pyrococcus furiosus, and (ii) a first estimate of the metallome for these hyperthermophilic species via ICP-MS. The metal contents of these cells were compared to parallel experiments using the mesophilic bacterium Escherichia coli grown under aerobic and anaerobic conditions. Fe and Zn were typically the most abundant metals in cells. Metal concentrations for E. coli grown aerobically decreased in the order Fe > Zn > Cu > Mo > Ni > W > Co. In contrast, M. jannaschii and P. furiosus show almost the reverse pattern with elevated Ni, Co, and W concentrations. Of the three organisms, a biosignature is potentially demonstrated for the methanogen M. jannaschii that may, in part, be related to the metallome requirements of methanogenesis. The bioavailability of trace metals more than likely has varied through time. If hyperthermophiles are very ancient, then the trace metal patterns observed here may begin to provide some insights regarding Earth's earliest cells and in turn, early Earth chemistry.