BIODEGRADATION OF HIGH DENSITY POLYETHYLENE BY BACTERIA ISOLATED FROM SOIL COLLECTED AT ARIYAMANGALAM DUMPSITE

Polyethylene (PE) a type of petroleum derived plastic, is the most widely used type across the world. Among the methods being practiced to deal with the increasing rate of plastic accumulation, bioremediation is considered to be a promising solution. Bioremediation is a sustainable approach for the management of environmental pollutants using microbial population. In this study, we have attempted to identify and isolate the PE degrading bacteria from the soil of Ariyamangalam garbage dumpsite, near Trichy, India. Five bacterial isolates that are capable of degrading plastic were identified by clear zone formation test and characterized using several biochemical tests. The physiochemical properties such as pH, temperature, weight, and electrical conductivity were also observed before incubating. High Density Polyethylene (HDPE) bags were cut into pieces; inoculated with each of the five bacterial isolates in the artificial nutrient media and subjected to degradation for 75 days at 37°C with continuous shaking in the incubator. After 75 days of incubation, analytical techniques such as Fourier Transform-Infrared Spectroscopy (FT-IR) and Gas Chromatography Mass Spectrometry (GC-MS) were performed to confirm the degradation of PE and to identify the degraded intermediary compounds present in the inoculum. Some of the intermediary compounds are found to be of pharmaceutical and commercial importance. Scanning Electron Microscope was used to observe the surface erosion of HDPE strips; structure of bacteria. The most efficient HDPE deteriorating bacterial isolates were identified as Staphylococcus sp. with 46% and Bacillus sp. with 43%.