ABSTRACT
This chapter shows that the technique of growth yield estimation during continuous culture is an incisive heuristic aid toward enhancing our understanding of microbial bioenergetics. The rate of change of the pH of the growth medium was set by the rate of aeration and the rate of respiration, which in turn could be adjusted by varying the steady-state population density through manipulation of the buffering capacity of the inflowing medium in the reservoir. A variety of carbon sources was employed to limit growth under aerobic and anaerobic conditions. The terms "uncoupled growth," "overflow metabolism", "slip reaction," and "energy spilling" have all been used to describe the apparent inefficiency of utilization of ATP for growth. Upon investigating molar growth yields of Desulfovibrio during sulfate respiration Senez, for example, observed values that were too small to permit the conclusion that full coupling of oxidative phosphorylation to respiration was operative.
