Degradation of High-density Polyethylene Mediated by Fungus Talaromyces liani JA2HS

Abstract

High density polyethylene (HDPE) waste accumulation in the environment is one among the major threats faced globally for the last quarter of century. The current study deals with isolation, characterization and mycodegradation analysis of the HDPE strips by a potential fungus isolated from garbage dump yard. Based on morphological characterization, the isolated strain was identified and designated as Talaromyces liani strain JA2HS. Until now, there have been no reports of HDPE degradation using T. liani. The HDPE strips were subjected to degradation by the fungal isolate JA2HS for 90 days after optimization of growth and environmental parameters. The extent of degradation was confirmed by measuring the weight of the residual strip and the amount of CO₂ evolution by Sturm test. A partial 72.7% degradation of the HDPE strip was observed, followed by the evolution of 18.5 g/L CO_2. Enzyme studies were conducted to test the presence of ligninolytic enzymes (laccase, manganese peroxidase and lignin peroxidase) responsible for the biodegradation of the plastic strip. The fungal biomass estimation and hydrophobicity test were also performed. Mycodegradation analysis of the HDPE strip was further confirmed using analytical techniques such as FTIR, SEM, and AFM. This is the first study revealing the HDPE degradation using T. liani mediated by ligninolytic enzymes.