Hence, it is an important source for screening polyolefin plastics degrading microorganisms. Many hydrocarbon-degrading microorganisms have been isolated from petroleum-contaminated soils, such as Pseudomonas sp. PP3, Pseudomonas sp. PP4, Enterobacter sp. MX1 , Pseudomonas aeruginosa DN1 and Bacillus subtilis DM-04 .