Evaluation of Biodegradation Efficiency of Xylene Pretreated Polyethylene Wastes by Isolated Lysinibacillus fusiformis

Abstract

The ability of the bacterial degradation of low-density polyethylene (LDPE) waste by Lysinibacillus fusiformis isolated from hydrocarbon-contaminated soil was investigated in the present study. The potential of the bacterial isolate to utilize LDPE waste bags of two different thicknesses in a month as a sole carbon source in mineral salt media was assessed. Further, the effect of pretreatment by xylene on the bacterial degradation of LDPE waste bags (0.5 percent w/v) in 30 days was investigated. The isolated Lysinibacillus fusiformis was able to degrade 9.51 percent of LDPE with 30 μm thickness but able to degrade only 1.45 percent of LDPE having 50 μm thickness. The bacterial biomass was 1.77 times higher on LDPE- 30 μm containing media in comparison to LDPE- 50 μm. The xylene pretreatment of LDPE wastes enhanced the biodegradation efficiency of isolated Lysinibacillus fusiformis to 12.09 and 1.97 percent respectively in 30 μm and 50 μm thick LDPE bags. The xylene pre-treatment improved the bacterial growth on media with LDPE of both thicknesses. The adherence of bacterium on the surface of LDPE was found more on 50 μm thick xylene treated LDPE compared to its untreated LDPE than 30 μm thick LDPE films. The xylene pre-treatment of polyethylene waste had an additive effect on the biodegradation of waste LDPE films with a significant effect on thickness.