Low-Density Polyethylene (LDPE) Degradation by Consortia of Chryseobacterium Sp. and Methylorubrum Spp. Isolated From a Solid Waste Landfill

Abstract

Plastics are ubiquitous materials; however, their improper disposal and slow degradation make them environmental pollutants. This study aimed to analyze the degradation of low-density polyethylene (LDPE) by bacterial consortia isolated from a solid waste landfill. LDPE-utilizing bacteria were isolated and selected based on their 2,3,5-triphenyltetrazolium chloride (TTC) reduction time. These were then formulated and evaluated as three bacterial consortia. From 160 isolated bacterial strains, 28.1% demonstrated LDPE-degrading capabilities. The three bacterial consortia degraded LDPE more effectively (5.71%–7.11% weight loss) compared to the individual constituent bacteria (5.41%–5.95%). Consortium 6, comprising Chryseobacterium cucumeris and Methylorubrum strains, achieved the highest polymer weight loss (7.11%), with a degradation rate of 0.00123 g·day−1, a residual LDPE half-life of 563.41 days, a 31.86% reduction in tensile strength, and notable functional groups changes compared to an uninoculated control. These results demonstrate the high LDPE degradation potential of landfill-isolated bacteria. These ubiquitous, nutritionally versatile, and adverse-conditions-tolerant bacteria, when combined in consortia, exhibit synergistic effects that accelerate polymer degradation.