Isolation And Characterization Of Marine Petroleum Degrading Bacteria

Petroleum pollution has become a serious environmental problem, especially in marine environments, due to oil production, transportation, and disposal. There have been many incidents of large-scale spills all over the world, the majority with serious consequences to the environment。The technologies commonly used for the oil contaminated sites include physical, chemical, and biological processes. Bioremediation is the promising technology for the treatment of these contaminated sites since it is cost-effective and will lead to complete mineralization.The purpose of this study was to screening the oil-degrading bacteria from surface seawater in the Dalian Port and study its degradation characteristics.The main results are as following:(1) Fourteen petroleum hydrocarbon-degrading bacteria were screened from surface seawater in the Dalian Port. Two dominant bacterial strains(HD-1,HD-2) was selected for the further study.(2) Based on 16S rDNA sequence analysis, the HD-1 was identified as Donghicola xiamenensis while the HD-2 was was identified as Pseudoalteromonas.(3) Under the condition of 22℃,120r/min,7-day degradation rate to 0# diesel oil of Donghicola sp.ED-\and Pseudoalteromonas sp.HD-2 reached 79.6%and 79.6% respectively.(4) After 7-day of cultivation under the condition of 22℃ 120r/min,and analysis of gas chromatography,there comes the conclusion.The Donghicola sp.HD-1 and Pseudoalteromonas sp.HD-2’s degradation rate to the components of n-alkane was 84.4% and 39.6% respectively.Among them, the Donghicola sp.HD-l’s degradation rate for C11 is highest(90.9%) and degradation rate for C25 is lowest(73.3%). Pseudoalteromonas sp.HD-2’degradation rate for C11 is highest(73.8%),and degradation rate for C25 is lowest(27.7%).(5) Use adsorption method to immobilize the experimental strains. Using medical stone and sand hole quality fixed mixed bacteria liquid. Results showed the immobilized strain has higher petroleum hydrocarbon removal efficiency than the free strain. The medical stone removal efficiency of immobilized bacteria was up to 98%.