Total degradation of 6-aminonaphthalene-2-sulphonic acid by a mixed culture consisting of different bacterial genera

A mixed bacterial culture consisting of eleven different strains was investigated in view of its ability to degrade 6-aminonaphthalene-2-sulphonic acid (6A2NS). Taxonomic characterization of the microorganisms showed that they belonged to three genera: Flavobacterium, Bacillus and Pseudomonas. None of the single strains could degrade 6A2NS. Some of 4–5-member co-cultures degraded it, but lost the ability in future subcultures. Only the mixed culture consisting of all eleven strains were stable and efficacious in degradation through numerous subcultures. The well-adapted mixed culture degraded the compound fast and without accumulation of intermediates, with a low increase in cell biomass and a high degree of mineralization.