[39] In vivo nuclear magnetic resonance in study of physiology of sulfate-reducing bacteria

Publisher Summary This chapter discusses in vivo nuclear magnetic resonance (NMR) in the study of physiology of sulfate-reducing bacteria (SRB). NMR spectroscopy is one of the most powerful analytical methods, which allows the qualitative and quantitative characterization of chemical mixtures, the determination of the isotopic distribution within molecules, and the measurement of reaction rates in the steady state. For in vivo NMR experiments to yield useful results, the sample must be maintained under defined and homogeneous physiological conditions. Phosphorus-31 is considered the most popular nucleus for in vivo NMR studies, owing to its high relative sensitivity and the importance of phosphorylated metabolites in energy metabolism. The accuracy of the pH measurement by NMR is largely determined by the validity of the titration curve used to relate chemical shift and pH. NMR permits observation only of freely mobile metabolites, therefore higher phosphorylation potentials are measured in some systems by in vivo NMR than by destructive analytical methods.