The Bioremediation And Microbial Diversity Of Petroleum Contaminated Soil

The paper adopted the outdoor potted simulation method, planted4kinds of adapting theloess plateau climate and conditions patience plants under0g/kg,5g/kg,10g/kg,15g/kg,20g/kg oil pollution stress. After seedling adaptation, collected25samples of root soil to exploremicrobial diversity. Used traditional microbiological plating method to discuss species andquantity of culturing microorganisms; Used acid-base titration to measure total microbialrespiration intensity in soil samples and representd the extent of the microbial activity and soilbiochemical intensity; Used biolog automatic detection system, through average well-colordevelopment, diversity index, changes of different carbon source, principal componentanalysis to discuss microbial diversity in soil samples.Based on the research of soil microbial diversity under oil pollution stress, screened oildegradation bacteria and investigated4strains oil composition degradating performance byselecting medium (liquid); Adopted the weighing method to measure crude oil degradatingrate; Used gas chromatography to analysis degradable component content changes; Acidprecipitation method was used to extract strain produced surface active substance, and usedTLC qualitative analysis them. After inquiry strain oil degradation performance,implementated the petroleum contaminated soil bioremediation simulation validation testunder indoor condition with chemical additive. Main conclusions as follows:1. Vegetation can improve the microbial diversity, and high level oil stress on soilmicrobial diversity protection is more obvious. Moreover robinia pseudoacacia soilmicroorganisms’ resistance of oil pollution stress is strongest; Oil pollution stress can promotethe soil microbial diversity. In general, the soil microbial diversity increase within0to10g/kg oil pollution stress level increase, then gradually reduced.2. The overall situation of plant soil microorganisms using carbon source under variableoil pollution stress is different,10g/kg microbial carbon source utilization ability is stronger.As oil pollution stress levels change, plant soil microbial carbon source utilization taxonchange too, then advantage communities change; Plant soil microbial carbon sourceutilization ability in different oil pollution levels appear differentiation, major differentiationinclude carbohydrates, plant-based polymer and amino acids, the corresponding taxa havebigger influence on the microbial diversity. 3. Screening test for4strains with larger bacteria growth, smaller oil viscosity on walland dispersion ability of crude oil are carried out. Number the strains1-32,1-23,2-4, F-1,their diesel oil degradation rate reached66.90%,55.38%,72.31%and55.38%in turn. Threestrains of bacteria identification results are:2-4strains is Rhodococcus rubber.1-32strains isPseudomonas xanthomarina.1-23strains has high sequence similarity (98.4%) withPseudomonas indoloxydans IPL1.4. After4oil degradation bacteria effect crude oil, total group scores compared withcontrast decrease by20.71%~25.00%. Verification test shows that4strains of bacteria areeffective on oil pollution stess degradation, degradation rate range between10.00%~14.00%.The degradation effect begin to play after bacterium joining15d,45d is best and thendecreasing; The chemical additives influence is different between strains, the overall effect isadding anionic surfactants SDS alone better than electron acceptor hydrogen peroxide andbetter than two hybrid adding.