Nitrogen and phosphorus optimization using Box-Behnken design to enhance the biodegradation of mixed phenols by a novel Pseudomonas isolate

Ammonium salt and phosphate concentrations in the media were optimized using Box-Behnken statistical design to enhance the biodegradation of mixed phenols by a novel 2,3-dimethylphenol-utilizing Pseudomonas isolate. By regression analysis, a secondary model on the relationship between degradation rates and medium components was established. In all the situations studied, maximum degradation rate (97.3%) was obtained when the concentrations of mixed phenols, ammonium sulfate, and phosphate (dipotassium hydrogen phosphate plus sodium dihydrogen phosphate) were kept at 250 mg/L, 44 mg/L, and 184 mg/L, respectively. The results illustrated the potential of bacterial remediation of phenolic pollutants without eutrophication caused by the addition of excessive nitrogen and phosphorus nutrients.