Biodegradation of Low Density Polyethylene by Selected Bacillus sp.

Abstract

The necessity of environment friendly disposal policies designed for the biodegradation ofsynthetic plastics is tremendously crucial and need attention in the present scenario, consideringthe hazardous impact of widely used packaging material such as Low Density Polyethylene(LDPE) on the environment. Our study aims to explore the degradation of LDPE by three strainsof Bacillus sp. i.e ISJ51, ISJ55 and ISJ57. The magnitude of biodegradation was evaluated byseveral techniques comprising weight loss of the polyethylene sample, reduction in bacterialhydrophobicity and estimation of biomass attached to the polyethylene film. The maximumbiodegradation i.e., 1.5%, as well as protein content (0.75 µg/cm2) of bacterial biofilm adheredon LDPE was observed in Bacillus sp. strain ISJ55 after 60 days of treatment. ISJ55 alsodemonstrated more hydrophobicity in comparison to ISJ51 and ISJ57, since, a 20.3% reductionin culture turbidity was specifying better attraction towards hydrophobic substances. SEManalysis revealed that ISJ55 exhibited morphological changes in polyethylene surface whileFTIR images showed functional changes after an incubation of 60 days. The establishment ofbiofilms on polyethylene surface and adhesion capabilities of bacteria are deliberated as thefirst step in the process of biodegradation. Therefore these results show that the isolate ISJ55can colonize, modify and utilize LDPE as a sole carbon source, signifying the potential ofBacillus sp. to degrade LDPE film. This manuscript also paves the way for future studies onbiodegradation to resolve the universal issue.