The Correlation of Bacterial Growth with Oxygen Consumption

Abstract

Although the oxygen consumption of growing cultures of bacteria has been suggested as a possible criterion of growth by a number of investigators (Wohlfield, 1930 and Martin, 1932), few have found any correlatiotk except for a limited incubation time. Generally, the respiration per cell increased to a maximum during the early part of the logarithmic phase of growth, then gradually decreased. This phenomenon has been ascribed by some investigators to inherent differences in the metabolic properties of the cells at different stages of growth. Others have attributed it to changes in cell size or environment. The amount of carbon dioxide evolved by cultures of bacteria as a measurement of metabolic activity was used by Huntington and Winslow (1937)-who attempted to correlate this with cell volume at various stages of growth. They found, however, that the increase in cell volume during growth could not account adequately for the increase in the amount of carbon dioxide produced. Martin (1932) and Clifton (1937) compared the rate of oxygen uptake with the rate of growth of the bacteria. Martin showed that the oxygen consumption per cell and the surface area per cell attained maximum values simultaneously. Clifton suggested on the basis of his experiments that the rate of bacterial metabolism per cell is highest during the early phases of growth because of the increased size of the cells at this time. He stated, however, that attempts to explain the differences in the rate of metabolic activity at various phases of growth on the basis of changes in cell size and physiological activity of the cells had not 549