Studies on Low Density Polyethylene (LPDE) Degrading Microorganisms Isolated from Dumpsite Soil

Abstract

Background: Low-density polyethylene (LDPE) is a commonly used thermoplastic material produced from ethylene. Its indiscriminate disposal has led to significant environmental accumulation, posing serious ecological threats. Certain microorganisms, however, can utilize LDPE as a source of carbon and energy. This study investigates the potential for microbial degradation of plastic wastes by isolating and characterizing microorganisms from dumpsite soils containing LDPE. Preliminary findings suggest the presence of microbial species capable of initiating LDPE breakdown, highlighting a possible biotechnological approach to plastic waste management. Aim: This study aimed to determine the biodegradation potential of bacterial and fungal isolates associated with low-density polyethylene (LDPE). Study Design: Laboratory-based experimental research conducted at Ajayi Crowther University, Nigeria, from January to December 2019. Methodology: Soil samples were collected from an LDPE-polluted dumpsite, and microorganisms were isolated using serial dilution and agar media. LDPE-degrading potential was screened using pre-treated LDPE strips in single and mixed cultures. Microbial growth, weight loss, and structural changes in LDPE were monitored, with FTIR used to confirm polymer modification. Isolates were identified through biochemical and molecular techniques. Results: Thirteen microorganisms were isolated, including Bacillus spp. (5), Aspergillus spp. (5), Penicillium spp. (2), and Fusarium spp. (1). Aspergillus niger and Pseudomonas aeruginosa, both individually and in consortium, exhibited the highest LDPE degradation, with 5% weight loss and significant structural modification confirmed by FTIR.