ABSTRACT
In addition to the classical techniques used in geomicrobiology (described in Chapter 7), in the past three decades, molecular tools have become increasingly important in the study of the presence, activity, and mechanism(s) of catalysis by geomicrobial organisms. Today, various molecules (deoxyribonucleic acid [DNA], ribonucleic acid [RNA], protein, and constituents of lipids) are used to detect speci c geomicrobial agents in situ, and by coupling measurements of their isotopic composition to the identi cation of these molecules, it is possible not only to identify geomicrobial agents but also to make inferences about their metabolic activity. Rapid advances in whole genome sequencing and biophysical sorting are greatly expanding our appreciation of the genetic potential of isolated geomicrobial organisms, as well as uncultured species from the environment. Finally, the application of molecular genetic, cell biological, and biochemical techniques to study the genes and gene products that catalyze geochemically signi cant reactions is permitting geomicrobial processes to be understood mechanistically. Together, these molecular tools can provide us with the information, we need to be able to predict when a geomicrobial process will occur and estimate its impact on the geochemistry of the environment.
