Molecular geomicrobiology: genes and geochemical cycling
Jennifer Macalady 1, Jillian F. Ban¢eld
Department of Earth and Planetary Science and Department of Environmental Sciences, Policy, and Management,
University of California, Berkeley, CA 94720, USA
Received 11 July 2002;received in revised form 30 August 2002;accepted 3 October 2002
Core geosciences concepts are being fundamentally revised as the result of breakthroughs in geomicrobiology.
Revolutionary discoveries have resulted from increased effort devoted to study of microorganisms in the context of
their environments. Much recent progress has been made possible by genetic data, particularly those that allow the
description of microbial populations in situ. New gene and genome sequences are elucidating previously unexpected
or unexplained interactions between microorganisms and Earth materials, with implications for key geological
phenomena such as the formation of ore deposits and the regulation of global climate and surface oxidation state.
Genetic data have also led to extensive revision of our understanding of the pace and mechanisms by which evolution
occurs. Yet, the field of molecular geomicrobiology remains in its infancy. In the foreseeable future, merging of
modern biogeochemistry with molecularly resolved ecological studies will inspire the development of integrated
models for the processes that shape the Earth.
/ 2002 Elsevier Science B.V. All rights reserved.
Keywords: geomicrobiology;geochemistry; evolution;genes;genomes;ecology
What does ‘molecular geomicrobiology’ mean?
Although this could be interpreted as ‘molecular
biology applied to geologic systems’ we use the
term to describe the search for molecular-level
understanding of coupled biological and geo-
chemical processes. Geoscientists have moved
from describing complex mineral surface reactions
using empirical rate laws to analyzing molecular
interactions at a fundamental level to determine
kinetic parameters with predictive value . Sim-