Biodegradation of 2,4-dichlorophenoxy acetic acid (2,4-d) by pseudomonas cepacia: Stoichiometric study

Pseudomonas cepacia biodegraded 2,4-dichlorophenoxyacetic acid (2,4-D) according to the following stoichiometric equation: C₈ H₆ Cl₂ O₃ + c₁ O₂ + c₂ NH₃ → c₃ CH_x N_z O_y + c₄ CO₂ + c₅ H₂ O + c₆ Cl_? + c₇ REIM where CH_x N_z O_y represents the bacterial cells and REIM is the residual extracellular intermediate metabolites. The stoichiometric coefficients c₁ to c₇ were determined from C, N, O, H and Cl balances together with the experimental data on the biodegradation of ¹⁴ C-carboxy-labeled-2,4-D and ¹⁴ C-ring-uniformly-labeled-2,4-D. The stoichiometric equation obtained predicted satisfactorily the total oxygen consumption for and the total heat production from the biodegradation of 2,4-D for a wide range of initial concentrations from 80 to 500 mg/L.