SOME PHYSIOLOGICAL-CHARACTERISTICS OF A PHOSPHATE REMOVING BACTERIUM ISOLATED FROM ANAEROBIC AEROBIC ACTIVATED-SLUDGE/

We succeeded in the isolation of a phosphate removing bacterium which takes up casamino acids while releasing phosphate anaerobically and ta kes up phosphate aerobically. The function of excess phosphate accumul ation was induced by alternating anaerobic incubation with organic sub strates and aerobic incubation without organic substrates. The followi ng physiological characteristics were shown by further investigation. (1) The presence of casamino acids in aerobic incubation did not inhib it greatly the induction of excess phosphate accumulation, but suppres sed the uptake of phosphate because the cells take up casamino acids u sing the energy produced by the hydrolysis of polyphosphate even in ae robic conditions. (2) Within one hour in anaerobic conditions the cell s had taken up casamino acids to as much as 25% of the cell dry weight aid the rate of ammonium excretion was small against that in oxidativ e metabolism. In anaerobic conditions the synthesis of DNA did not occ ur and the ratio of excreted phosphorus to removed glutamic acid was a bout 0.5 M/M. This value is very small against that required for the p olymerization of the substrate. Therefore a large amount of low molecu lar weight material, such as amino acids, seems to be accumulated in t he cells.