Polyethylene Degradation Potential of Comamonas testosteroni and Pseudomonas sp. isolated from soil samples of Plastic Recycling Centre, Lagos, Nigeria.. Polyethylene Degradation Study.

Polyethylene polymer with its advantages of being strong, light-weighted, and durable, however, possesses disadvantages such as resistance to biological degradation and harmful to the natural environment. Solid waste related problems pose threat to megacities like Lagos. In this study, pooled soil samples collected randomly from a plastic recycling centre in Lagos were plated in Minimal Salt Medium with polyethylene as sole carbon source and screened for polyethylene utilization. The total dissolved organic matter was determined using the TOC titrimetric method and Fourier Transform infrared spectroscopy (FTIR) analysis was used to check the functional groups changes of the Low Density polyethylene (LDPE) material during the degradation period. Two bacterial strains Comamonas testosteroni (PRC1) and Pseudomonas sp. (PRC2) able to grow on polyethylene were isolated. The persistence of the two isolates in the liquid medium after three months of incubation showed their ability to utilize the polyethylene material which served as carbon/ energy source for them. There was evolution of carbon (iv) oxide gas from the degradation experiment which was highest at the 15th day when the two isolates were combined as was observed with the TOC; the FTIR revealed disappearances of peaks, formation of new peaks and reduction of some original peaks present in the control sample. Peaks 1471cm-1 and 1647cm-1 corresponding to Alkenyl C=C stretch and 1716 cm-1 for carbonyl group disappeared in the samples treated with PRC1, PRC2 and a combination of the two isolates respectively. The isolates showed degradative ability on the polyethylene (LDPE) material and thus can be used for biodegradation of polyethylene waste materials in the environment.