Effects Of Oil Pollution On Soil Microbial Diversity In The Qinghai-tibet Plateau Permafrost Regions

In recent years,accidents occur frequently in Qinghai-Tibet Plateau permafrost region during the extraction,transportation,and refining of petroleum,and the frozen soil environment are polluted by those problems.In this paper,I will study the variety of microorganism in frozen soil that was polluted in Qinghai-Tibet Plateau regions,and continue monitoring the temperature of soil in the north river region,and enrich and sieve the oil indigenous bacteria at low temperature,and analyze the changes of microbial population structure under the oil pollution and oil mixed bacteria species structure by the High-throughput-sequencing,and combine permafrost oil pollution reparative experiment with the low temperature in the laboratory,then we can study prostheses effect of the indigenous bacteria at low temperature in different experimental conditions of oil pollutants in soil,thus,technical support for the the bioremediation of petroleum contaminated project in permafrost region can be offered.The major achievements of this thesis can be discussed in the following aspects :(1)During summer from middle July to early September,the soil temperature peak in Beiluhe area of Qinghai-Tibet Plateau,it is the highest period for microbial activity,and it is also the critical period for microbial remediation of oil pollution.The soil of Beiluhe area shows weak acid,it contents higher organic substance,and there are more nutrient elements that is for the microbial remediation of petroleum pollution in the north river area of soil,the total nitrogen and phosphorus and others can fundamentally satisfy the demand of the microbial remediation of petroleum pollution with a low concentration,when it is a high concentration of oil pollution,we need to adopt the method of adding nutrients to meet the requirements of repair process of nutrient.(2)The oil pollution affects the structure of soil microbial population,the High throughput sequencing shows that there is a quite difference among the non-polluted soil(surface layer,the lower),diesel oil-polluted soil and the engine oil-polluted soil to the advantage bacterium group in the Beiluhe region,which reflects that the oil influents on the structure of soil microbial a lot,and changes the original community structure,and makes some microorganisms extinction,at the same time,the oil degradation bacteria which is adapt to C source proportion is increasing,and the spot oil pollution efficiently helps oil degradation bacteria laboratory screening of domestication.(3)Constant temperature oscillation nutrition box is used for the enrichment and sieving of indigenous bacteria at low temperature,the method of microbial tablets and the electronmicroscope are used for the test,and the result shows that the microbial growth form of the diesel oil and the engine oil is mainly with rods.Cryogenic nutrition article shake flask test shows: low temperature degradation bacteria for diesel oil degradation rate is above 60% in17 days;and in 30 days the oil degradation bacteria at low temperature for diesel oil degradation rate is 54.7%.(4)The High throughput sequencing analysis shows that there are some certain similarity in structure between indigenous low-temperature diesel oil degradation bacteria and engin oil degradation bacteria,that is the main bacteria is proteobacteria.Indigenous low-temperature diesel oil degradation bacteria sequencing shows 71 species,the dominant bacteria are Alkanindiges(54.4%)and Pedobacter(18.2%).Indigenous low-temperature engin oil degradation bacteria sequencing shows that 91 species,the dominant bacteria are PYR10d3_norank(23.0%),Sulfuritalea(19.4%),Parvibaculum(10.94%)and Sphingobium(10.89%).(5)The diesel oil degradation of soil test shows that the psychrophile for diesel oil degradation bacteria liquid has good degradation effect of diesel pollution,improving the ratio of bacteria liquid and adding nutritive salt and surfactant can improve the efficiency of its degradation;in different diesel pollution concentration,the efficiency on microbial degradation diesel soil is different,,the efficiency is far higher than the high intensity of diesel pollution degradation when it is in the low pollution soil concentration.