Screening Of Hydrocarbon-degrading Bacteria And Research On Simulation Of Marine Spilled Oil Bioremediation

With the development of petroleum industry, people started to set foot in marine petroleum exploitation. Therefore, oil pollution occurs every year and destroys marine environment seriously due to the well blowout, oil leak, transport ships collision and sinking, and petroleum pipeline leak, etc.. So, measures should be taken timely and effectively to clean up spilled oil as soon as possible.There are three kinds of spilled oil clean-up measures: physical method, chemical method and biological method. Bioremediation is the safest and most economic technique to solve oil pollution. Researchers have been studying bioremediation for many years. The research in this area is later in our country, so it should be studied further.The contents of this thesis were divided into six parts: the first part was literature summarization; the second part was screening of hydrocarbon-utilizing bacteria (HDB) and optimization of culture condition; the third part was testing of degradation rate by HDB; the fourth part was affection of biosurfacants on oil degradation; the fifth part was inside simulation of marine oil spill bioremediation; the sixth part was conclusion.In this thesis, four strains of HDB were isolated from seawater samples collected from the coastal areas of Qingdao, and they could degrade hydrocarbons effectively. Affection of biosurfacants on oil degradation was studied briefly. Inside simulation of marine spilled oil bioremediation was researched in the last part of this thesis and gas chromatography-flamed iron detector (GC-FID), Gas chromatography-mass spectrometry (GC-MS) were mainly used in qualitative and quantitative of normal alkanes and aromatic hydrocarbons which showed the fingerprint changes of oil composition. The results of this paper could provide a support for the bioremediation of oil polluted seawater. The main conclusions are as follows:1. Four strains of HDB were isolated from seawater samples collected from the coastal areas of Qingdao and they could degrade hydrocarbons effectively. They were affiliated as Pimelobacter, Marinococcus, Microbacterium, and Planococcus, respectively. All of the strains grew well in neutral-alkaline condition and could withstand high concentrations of salt (NaCl) and the activation of bacteria could be inhibited when the temperature was very low. All of them are fit for marine environment. This study invested the ability of them to utilize some kinds of hydrocarbons. All of them grew well on hexadecane (C16) and strain N4 was the most superior hydrocarbon degrader. The mixture of N1, N2, N3 and N4 has the highest petroleum degradation efficiency and the initial pH being 8 and the concentration of NaCl being 3 %. Oil degradation rates could increase effectively up to 17 % by adding biosurfactant in seawater and adding biosurfactant in advance was favorable.2. Marine spilled oil bioremediation was simulated. The oil biodegradation rate was 34.19 % only with the mixture of four strains, 55.52 % without fermentation liquor, 46.10 % without nutrient and 61.43 % with all of them. Addition of nutrients and fermentation liquor could improve the biodegradability of oil effectively.The results of this paper could provide theoretic basis and technical surport for field application of bioremediation of marine oil spill.