SOME PHYSIOLOGICAL-CHARACTERISTICS OF A PHOSPHATE-REMOVING BACTERIUM,MICROLUNATUS-PHOSPHOVORUS, AND A SIMPLIFIED ISOLATION AND IDENTIFICATION METHOD FOR PHOSPHATE-REMOVING BACTERIA

Some physiological characteristics of a phosphate (Pi)- removing bacte rium, Microlunatus phosphovorus, are investigated using aerobically gr own cells and cells exhibiting excess Pi accumulation (EPA) in order t o determine a simplified isolation and identification method for other Pi-removing bacteria. Such a method would save on the amount of steri le equipment needed, and reduce the number of experimental steps and l abor time. The EPA activity of the isolate reached a plateau 13 hours into the anaerobic incubation time, but it reached 70% of that level a fter only 5 hours. The EPA activity of the cells during the stationary growth phase was higher than that during the exponential growth phase . Polyphosphate (polyP) accumulated in the cells was shown to be used as an energy storage material (a phosphagen) under both aerobic and an aerobic conditions. During aerobic starvation, the rate of decrease in the ATP concentration of the suspension of cells that contained polyP was markedly less than that of the suspension of cells without polyP. Therefore, bacterial cells rich in polyP survive longer than bacteria l cells lacking polyP. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.