Isolation and Characterization of Pseudomonas sp nai8 Capable of Naphthalene Degradation

Using the base mineral medium containing 800 mg/L of naphthalene, a degrading bacteria with higher degradation activity was isolated and identified as Pseudomonas sp. based on physiological, biochemical characteristics and 16s rDNA sequence. The effects of Pseudomonas sp. Nai8's degrading ability, e.g., naphthalene concentration, temperature and pH, were investigated. The results showed that under the condition of 30 degrees C, pH 7.0 and concentration of naphthalene of 1000 mg/L, the degradation rate in 48 and 96 h was 70.4 and 96.2 %, respectively. Pseudomonas sp. Nai8 could also degrade other aromatic hydrocarbons, such as dimethylbenzene, phenol, benzyl acid, utilizing each of them as sole carbon and energy source for its growth, which showed the strain Nai8 has good biodegradation diversity. The kinetics of naphthalene degradation by Nai8 was also calculated and the naphthalene biodegradation constant (k) was 0.038 h(-1) with R-2 value 0.9679, which showed that the strain nai8 could degrade naphthalene remarkably.