ABSTRACT
Two fundamental goals in aquatic microbial ecology are to elucidate the pathways and to quantify the fluxes of carbon and energy through microbial communities in nature. David M. Karl and colleagues have described novel approaches for the independent estimation of energy flux and carbon flux by direct measurements of the turnover of the cellular adenosine triphosphate (ATP) and total adenine nucleotide (TAN) pools. The central role of ATP in the stoichiometric coupling of energy-yielding and energy-requiring metabolic reactions has been known since the pioneering research of R. Lipmann. From time-course information on the change in ATP and TAN pool specific radioactivity, the turnover rates can be quantified and the results extrapolated to estimates of energy flux and specific growth rate. Karl and P. Bossard devised a novel method for ATP pool turnover in cell cultures or natural populations of microorganisms.
