Degradation of 6-aminoaphthalene-2-sulphonic acid by mixed cultures: kinetic analysis

Degradation of 6-aminoaphthalene-2-sulphonic acid (6A2NS) by a mixed bacterial culture (BN6/BN9/escorting strain) and a defined mixed culture (BN6/BN11) via an interspecies transfer of 5-amino-salicylic acid (5AS) was investigated using a continuous culture. Steady-state values were obtained from the mixed bacterial culture but not the defined 2-species culture. The conversion of 6A2NS to 5AS was rate-determining. The Monod equation and an extended model regarding the interspecies transfer of 5AS were suitable for describing the relationship between biomass and substrate concentration depending on the flow rate of continuous culture.