Studies on the Construction of Crude Oil Degrading Bacterial Consortia and the Simulated Remediation of Marine Crude Oil Pollution

Author:Li Zuo Zuo

Supervisor:zhao lin

Database:Doctor

Degree Year:2017

Download:78

Pages:144

Size:4707K

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In June 2011,a serious crude oil spill occurred in China’s Bohai Penglai 19–3 oil field,which seriously influenced the ecology,mariculture and tourism of Liaoning province,Hebei province,Shandong province and Tianjin city.The main research contents and conclusions on remediation of Bohai oil pollution in this study are as follows:In this study,five crude oil degrading bacteria,including TCOB-1(Ochrobactrum)、TCOB-2(Brevundimonas)、TCOB-3(Brevundimonas)、TCOB-4(Bacillus)and TCOB-5(Castellaniella),were isolated from Bohai Bay.Through the analysis of hydrocarbon biodegradation,TCOB-4 was found to biodegrade more middle-chain n-alkanes(from C17 to C23)and long-chain n-alkanes(C31–C36).TCOB-5 capable to degrade more n-alkanes including C24–C30 and aromatics.On the basis of complementary advantages,TCOB-4 and TCOB-5 were chosen to construct a consortium which was capable of degrading about 51.87% of crude oil(2% w/v)after 1 week of incubation in saline MSM(3% NaCl).Its efficiency increased by 45% compared with single strain.AlkB gene and P450 gene of Bacillus TCOB-4,P450 gene of Castellaniella TCOB-5 are studied.Proposed tricosane/naphthalene/phenanthrene degradation pathways by Castellaniella TCOB-5 are studied through GC-MS.Tricosane is degraded through single terminal oxidation.The first step of degradation of naphthalene is oxygenation of C on 1,2.The first step of degradation of phenanthrene is oxygenation of C on 3,4 and 9,10.The results of simulated experiment show that the distribution of crude oil in seawater is influenced by both environmental parameters and microorganism.TCOB-4 and TCOB-5 could degrade crude oil in the early stage of bioaugmentation.However,their superiority decreased with the increase of bacteria abundance.TCOB-5 can continue playing a role because of its high efficiency.In this study,agar was employed as the support matrix for microorganisms(Bacillus TCOB-4 and Castellaniella TCOB-5),crude oil sorbents(Modified fly ash)and nutritive salts.The density of material MOP-1 is 1.00 g/cm3,BET surface area is 18.30 m2/g.About 49.72% crude oil was degraded by MOP-1 in 7 days incubation.