Cooperation between two strains of Enterobacter and Klebsiella in the simultaneous nitrogen removal and phosphate accumulation processes.

•Co-cultured bacteria could remove nitrogen and phosphate.•High removal was achieved by inoculation with the co-strains in wastewater.•The co-strains had a continuous removal effect in the batch reaction.•The napA2, narG and ppk genes in the co-cultures were upregulated.•In the co-cultured conditions, high levels of ATP and NADH were accumulated.