Effect of solid-liquid interface on metabolic activity of Escherichia coli.

Abstract

Whether and in what manner various solid-liquid interfaces affect the metabolic activities of E. coli was studied using 5 kinds of organic polymers, 4 kinds of clay minerals and 3 kinds of mineral oxides. Rates of glucose uptake and O2 consumption were determined with and without addition of each material. Three materials, styrene-divinylbenzene copolymer (SDB), polytetrafluoroethylene (TFE) and pyrophyllite, significantly increased the respiratory activity and simultaneously decreased the rate of glucose uptake. Other materials showed weak or no effects. When SDB and TFE were removed from the cell suspension, their effects on respiration and glucose uptake disappeared immediately. Thus, these effects were reversible. The glucose respiratory ratio was inversely proportional to the rate of glucose uptake. This relation is discussed in connection with the interface effect on the organism as a living system.