Kinetic behavior of some polyphosphate-accumulating bacteria isolates in the presence of nitrate and oxygen

This paper studies the phosphate uptake by pure cultures of Aeromonas hydro phila, Klebsiella oxytoca, Agrobacterium tumefaciens, and Aquaspirillum dis par in the presence of both nitrate and oxygen. It is shown that species we re able to respire both electron acceptors for phosphate accumulation. A. t umefaciens and A. dispar accumulated overall phosphate both in oxic and ano xic culture conditions, whereas A. hydrophila and K. oxytoca eliminated ove rall phosphate only in oxic conditions. A. dispar was able to remove phosph ate by reducing oxygen and nitrate simultaneously with the production of di nitrogen gas. The anoxic denitrification observed in the cultures of adapte d and nonadapted cells to nitrate showed that only A. dispar have a denitri fication rate superior when the cells were adapted to nitrate.