ABSTRACT
Bacterial growth is best examined in completely soluble substrates under optimum environmental conditions. Initially, bacterial growth patterns were made on batch-fed systems. Jacques Monod was one of the first bacteriologists to quantitatively examine the growth of bacteria in dilute organic solutions. He demonstrated that growth of bacteria was directly proportional to the substrate metabolism. Growth of large masses of bacteria in batch fed reactors showed that the bacterial mass increased until the substrate was essentially all metabolized and then slowly decreased. L. J. Pirt was one of the first microbiologists to modify Monod’s equations of bacterial metabolism to include endogenous respiration. The uptake of dissolved oxygen by bacteria is a direct measure of the energy used by the bacteria in metabolism of the substrate plus endogenous respiration. Denitrifying bacteria can utilize nitrate salts as electron acceptors for metabolism under the anaerobic environmental conditions.
