Optimization of Conditions for Naphthalene Biodegradation

Degradation of naphthalene by Burkholderia glathei, Alcaligenes denitrificans and Pseudomonas putida was optimized with respect to various environmental factors such as pH, temperature, salinity and addition of nutrients such as nitrogen and phosphorus. Maximum growth and biodegradation occurred at 1.0% of naphthalene at 30°C, pH 8.0 and 1.5% salinity. Addition of various nitrogen sources such as urea, ammonium nitrate and ammonium chloride as well as phosphorus sources such as KH₂PO₄ and Na₂HPO₄ resulted in an increased rate of biodegradation. A carbon to nitrogen to phosphorus ratio of 93:10:0.09 yielded maximum degradation of naphthalene. The application of the naphthalene degraders in abatement of pollution caused by naphthalene was studied in soil microcosm. The usefulness of immobilization technique for bioremediation showed encouraging results.