Construction of Multiple Bacterial Consortium and Its Application in Bioremediation of Petroleum-contaminated Soil

Three bacterial strains were isolated from petroleum-contaminated soil and identified as Rhodococcus sp.based on their 16S rRNA gene sequences and morphological,biochemical and physiological characteristics.Abilities to degrade petroleum were studied and compared among three isolates and four strains instored in our laboratory.The seven strains prefered to degrade different component of petroleum respetively.Multiple bacterial consortia were composed by different combination among the seven strains.Consortium D which consists of two strains of Rhodococcus sp,a Gordonia sp and a Pesudomonas sp showed much higher degradating-oil efficiency than any single strains and other consortia.Consortium D could degrade 70.3 % of petroleum totally and 71.4% of aromatic component in petroleum in 5 days incubation.Consortium D could also degrade 99.8% of C13-19 alkanes,92.6 % of C20-26 alkanes,82.2% of C27-32 alkanes and 90.2% phytane in petroleum.When consortium D used in bioremediation of petroleum-contaminated soil,it could remove more than 50% petroleum in soil.In condition of 10~30 ℃,pH 6.5~9.5 and inoculum106 CFU·g-1,the consortium D could degrade petroleum faster.The results indicated that Consortium D had potential used in bioremediation of petroleum-contaminated soil.