ABSTRACT
In addition to the techniques described in Chapter 8, molecular tools have become increasingly important in the study of the presence, activity, and mechanisms of catalysis by geomicrobial organisms. Today, various molecules (deoxyribonucleic acid [DNA], ribonucleic acid [RNA], protein, and lipids) are used to detect specic geomicrobial agents in situ and to make inferences about their metabolic activity. DNA sequencing has become routine, expanding our appreciation of the genetic potential of uncultivated organisms and complex natural communities from the environment. Isotope labeling approaches allow us to measure metabolic activity more directly and to specically link organisms with geochemical uxes. Finally, the application of molecular genetic, cell biological, and biochemical
techniques to study the genes and gene products that catalyze geochemically signicant reactions is unraveling the mechanisms underlying these processes. Together, these molecular approaches provide a window into the interactions between microorganisms and their geochemical environment and enable predictions about how these geomicrobial processes may be altered in response to environmental perturbations.
