Biodegradation of polyethylene thermolysis residue.

摘要

The ability of several microorganisms to degrade polyethylene thermolysis residue was investigated. This residue is mainly comprised of n-alkanes and n-1-alkenes ranging in chain length of 15 to 45 carbon units and therefore resembles crude oil. The microorganisms investigated were: Y. lipolytica ATCC 8662, Y. lipolytica ATCC 20460, A. paraffineus ATCC 19558, P. aeruginosa PAO1, P. putida ATCC 12633, R. rhodochrous ATCC 21766 and Rhodococcus sp. ATCC 29671. It was found that all seven microorganisms tested were able to degrade the polyethylene thermolysis residue. Results suggest that R. rhodochrous produced a biosurfactant when growing on the polyethylene thermolysis residue.; It was also found that the acclimation of the microorganism to the substrate was an important factor in the degradation of the residue. Using two different acclimation times, two different strains of R. rhodochrous were selected for in the acclimation step. The two different strains showed very different degradation patterns of the polyethylene thermolysis residue. Strain A showed almost no effect of chain length on the degradation rate of the hydrocarbons while the degradation rate of the hydrocarbons for strain B decreased with increasing chain length. This difference in the degradation pattern was attributed to the varying amounts of enzymes present in each strain. Another factor found to affect the degradation pattern was the liquidity of the polyethylene thermolysis residue.