ISOLATION OF A NEW TYPE OF POLYPHOSPHATE ACCUMULATING BACTERIUM AND ITS PHOSPHATE REMOVAL CHARACTERISTICS

Polyphosphate accumulating bacteria were isolated from activated sludge cultured in a fill and draw system with alternating anaerobic and aerobic conditions. One of the isolates, strain NM-1 tentatively identified with the genus Micrococcus accumulated a large amount of phosphorus and its content reached 166 mg of phosphorus per g of cells. This strain accumulated phosphorus rapidly under aerobic conditions in the absence of any organic substrates, and when glucose was supplied to this strain under anaerobic conditions, it released phosphate and took up glucose in a similar manner to activated sludge that has good phosphorus eliminating capacity. Micro-aerophilic growth conditions were required for the induction of phosphorus accumulating activity.