A Study On The Function Ability And Optimal Conditions Of Petroleum-Degrading Bacteria From Liaohe Estuary Wetlands

Liaohe Delta is the largest warm temperate coastal wetlands of Asia,with greatenvironment regulation function,economic value and ecological benefit.Because ofhuman pullutant emissions of land-based sources and over-exploitation of wetlandresources,wetland area is shrinking.Wetland ecosystems are being destroyed,andecological restoration of wetlands has become a common concern.Petroleum is one ofthe main pollutains of the Liaohe River Wetland,the oil field development and otherproduction activities result in heavily pollution of acres of land of Liaohe oil field andaround the region.The wetland is destructed by the rapid development of the oilindustry,and control of oil pollution in Liaoche River Wetland needs to be resolvedurgently.There are much research about the oil degrading bacteria at home and abroad,butmost of them are about spill oil pollution from oil well and marine oilpollution.What’s more,less research are to deal with the oil pollution in coastalwetland which have high salt and low temperature.Liaohe mouth wetland’s averagetemperature is low and has serious soil salinity, so common oil degrading bacteriacan’t work effectively.It has a very important significance to screen out highefficiency salt and low temperature tolerant petroleum-degradation strains to deal withthe Liaohe mouth petroleum contaminated soils.This study screen out high efficiencysalt and low temperature tolerant petroleum-degradation strains from the polluted soilof Liaohe mouth wetland.The survey found out the best growth temperature ofbacteria is30℃.Under the condition of high salt,the survey searched the optimizedcondition by adding hydrogen peroxide, twain-80and activated carbon fiber. Thesurvey shows that in order to get the best effect, the additive capacity of the threemedia mentioned above is respectively150mg/L,160mg/L and6g/L.Under threeoptimal conditions,the oil degradation rate all incrsased. After being cultured one week, oil degradation rate of salt tolerant strain (below10℃) is over40%. This ratecan reach80%at the optimal temperature (30℃). Furthermore，the oil degradationrate of reed fibrous root composite carrier immobilized lh-12under10℃and30℃reached58.63%and95.12%respectively，more than the free bacteria lh-1227.75%and18.94%respectively.