Of four strains of Acinetobacter isolated from a pilot plant exhibiting enhance biological phosphate removal from sewage, two strains (RA3116 and RA3117) accumulated more than 10 times the amount of polyphosphate accumulated by the other two strains (RA3114 and RA3123). Variants isolated from RA3116 and RA3117 showed polyphosphate levels similar to RA3114 and RA 3123. No correlation was found between the polyphosphate content of the strains and levels of several enzymes that have been implicated in polyphosphate formation.