Biodegradation of polyethylene based films used in water packaging by dumpsite bacteria

Abstract

Water sachet bags are Low-density polyethylene (LDPE) based polymers that are of widespread use in Nigeria. The accumulation of these sachet bags has resulted to severe environmental pollution. Microorganisms have been found to provide an eco-friendly and practical alternative to conventional methods in the clean-up of LDPE wastes in the environment. This study investigated the potentials of six bacteria strains Lysinibacillus xylanilyticus PE4, Pseudomonas aeruginosa PE2, Pseudomonas aeruginosa S1, Stenotrophomonas maltophilia S6, Pseudomonas aeruginosa W5 and Achromobacter xylosoxidans strain to degrade water sachet films. The degradation was monitored for a period of 56 days in vitro and the extent of degradation was measured using Fourier transform infrared spectroscopy and scanning electron microscopy coupled with EDX. FTIR spectroscopy analysis of the bacteria treated LDPE samples revealed changes in functional groups of LDPE samples as a result of hydrolysis and oxidation of bonds in the LDPE polymer. Also, the EDX elemental analysis of the treated LDPE and the untreated control showed a reduction in percentage elemental carbon and increase in the elemental oxygen of the treated LDPE films which is evident of degradation. The findings indicate strongly the degradation potentials of these bacteria strains on LDPE polymer, they therefore show significant promise for bioremediation of plastic wastes.