Abstract:

Naphthalene, typical of polycyclic aromatic hydrocarbons, is highly poisonous and hardly degradable. As the typical petroleum hydrocarbon composition, it is a severe environmental pollutant, and therefore there exists great difficulty in the bioremediation of oil-contaminated sites. Due to its poor water solubility, researches on naphthalene degradation are hindered seriously. In this paper, the strain of Acinetobacter johnsonii isolated from waste oil is employed to study naphthalene biodegradation with the ability both to degrade petroleum hydrocarbon and to wet inorganic impurities. The reaction conditions are optimized based on the researches on degradation factors and the biodegradation characteristics of naphthalene are manifested in the range of 50 to 2000 mg·L^-1. The dynamics behavior of A. johnsonii is studied on the degradation of naphthalene through the comparison of the Monod model and the Haldane model. The results indicated that the strain could utilize naphthalene as sole carbon and energy source to metabolize and 2000 mg·L^-1 naphthalene could be entirely degraded within about 146 h at 5% inoculum volume and 37℃. The Haldane model is suitable to describe cell growth and the substrate degradation behaviors while the Monod model is appropriate to depict naphthalene biodegradation with low initial concentration.

Key words: naphthalene, degradation, petroleum, environment, Acinetobacter johnsonii, kinetics, substrate inhibition

摘要：

萘是典型的多环芳烃，毒害大、难降解，既是重要的环境污染物，又是代表性的石油烃成分，成为各类油污染场地生物修复的难点。碍于其水溶性差而制约了相关研究。利用一株从废油中分离得到的兼具石油烃降解能力和润湿反转无机杂质能力的约氏不动杆菌开展了萘的生物降解特性研究。通过研究降解因素优化出基础的降解条件；在此基础上，在50～2000 mg·L^-1范围内研究了该菌对萘的生物降解特性；并利用Monod模型和Haldane模型对比研究了该菌降解萘的动力学行为。结果表明，该菌在以2000 mg·L^-1萘为唯一碳源的特定条件下，以5%的接种量可以在146 h左右实现萘的全降解；Haldane模型适合于描述菌株的生长和底物降解行为，而Monod模型只适合于描述低浓度下萘的生物降解特性。

关键词: 萘, 降解, 石油, 环境, 约氏不动杆菌, 动力学, 底物抑制