Degradation of chlorobenzoic acids by strains Rhodococcus ruber P25 and Microbacterium oxydans B51 under cometabolism

The destructor strains of polychlorinated biphenyls (PCBs) Rhodococcus ruber P25 and Microbacterium oxydans B51 decompose the main intermediates of aerobic bacterial destruction of PCBs - chlorobenzoic acids (CBC). It was found that when cultivating the M. oxydans B51 strain on biphenyl as a carbon source, colony-forming units increase by four orders of magnitude in 4 days, and when cultured on 2XBC - by three orders of magnitude in three days. The level of destruction of the substrate was 99.0-99.5%. When cultured under cometabolism conditions (CBC and biphenyl are present in the medium), the specific growth rate of M. oxydans strains B51 and R. ruber P25 increased by 1.53-1.58 times, and the destruction efficiency of 2XBC and 4XBC was 98.9-99.2%. The main metabolites of bacterial transformation of biphenyl and CBC in the medium have not been recorded, but the accumulation of chlorine ions has been established (after 5 days. the cultivation concentration was 64.98-98.05% of the maximum possible). The results obtained indicate the effective destruction of CKD by M. oxydans strains B51 and R. ruber P25 in the presence of an additional carbon source.