Study On Degradation Performance And Optimum Conditions Of Petroleum Hydrocarbon Degrading Bacteria Acinetobacter Venetianus WB1 And Pseudomonas Aeruginosa WB2

In this thesis,we focused on the two petroleum hydrocarbon degrading bacteria: WB1 and WB2,which were obtained from petroleum contaminated soil in Tianjin Binhai New Area.We carried out the study on the identification of these two strains,the performance of petroleum hydrocarbon degradation and the most suitable degradation conditions.The following results were obtained:WB1 was identified as Acinetobacter venetianus,which was oval shaped;WB2 was Pseudomonas aeruginosa,and its morphology was short.Logarithmic phase of WB1 was in 0-18 h and the number of strains grew rapid.WB1 reached saturation at about 18 h and then entered the stable phase.Logarithmic phase of WB2 was in 0-16 h and the number of strains grew rapid.WB2 reached saturation at about 16 h and then entered the stable phase.WB1 and WB2 both have a good degradation effect on petroleum hydrocarbons.The degradation rate of petroleum hydrocarbons was 69.80% and 76.16% respectively in 9 days,which were both proved to be highly efficient hydrocarbon degrading strains.The optimum growth temperature of WB1 and WB2 were 28°C and 35°C,respectively.The growth behavior was increased with the increase in temperature when the temperature was under the optimum growth temperature.The growth behavior was decreased with the increase in temperature when the temperature was above the optimum growth temperature.The optimal pH of WB1 and WB2 were 5 and 7.WB1 grew well under acidic conditions,it was a good acid resistant bacteria,suitable for cultivation under acidic conditions.WB2 in the neutral conditions had the best growth,which was suitable for the cultivation of neutral conditions.The optimum salt concentration of WB1 and WB2 were 0.5% and 2%,respectively.The growth of WB1 was better under the condition of low salt concentration,which was suitable for the low salt concentration conditions.The optimum salt concentration of WB2 was 2%,which was a low salt tolerant bacteria.After 60 days of petroleum contaminated soil bioremediation pilot plant-scale test,oil degrading mixed bacteria whose main components were WB1 and WB2 shown a very good result.It is expected that these two strains can provide potential practical use for in situ remediation of petroleum pollution in the near future.