Study on characteristics of phosphorus release and accumulation of the two different strains of Escherichia

Cultured with different carbon sources and different concentrations of phosphorus under anaerobic/aerobic condition, the characteristics of phosphorus release and accumulation of the two strains of Escherichia DCJ-1, DCJ-2 were discussed. DCJ-1 fed with acetate, considerable phosphorus was released and accumulated at 40mg/L PO₄^3-; and DCJ-1 had the capacity of phosphorus release and accumulation when the ratios of acetate/propionate were 5:1, 2:1, 1:2 and 1:5. DCJ-2 had a rather weaker capability of phosphorus release and accumulation in any ratios of acetate/propionate with the phosphorus concentration range from 10 mg/L to 40mg/L; and its capacity of phosphorus release was greater than accumulation. It was shown that the characteristics of phosphorus release and accumulation of the two strains were different. At the phosphorus concentrations of 50-60mg/L, DCJ-1 and DCJ-2 only released but did not accumulate phosphorus. It is implied that in different EPBRs, the phosphorus removal of the same bacteria is different owing to the different strains of bacterium in it, and different growing characteristics of strains resulted in different levels of phosphorus release and accumulation.