Degradation of polyethylene by Penicillium simplicissimum isolated from local dumpsite of Shivamogga district

Penicillium simplicissimum was isolated from a local dumpsite of Shivamogga district for use in the biodegradation of polyethylene. Degradation was carried out using autoclaved, UV-treated and surface-sterilized polyethylene. Degradation was monitored by observing weight loss and changes in physical structure by scanning electron microscopy, Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. P. simplicissimum was able to degrade treated polyethylene (38 %) more efficiently than autoclaved (16 %) and surface-sterilized polyethylene (7.7 %). Enzymes responsible for polyethylene degradation were screened from P. simplicissimum. Enzymes were identified as laccase and manganese peroxidase. These enzymes were produced in large amount, enzyme activity was calculated using spectrophotometric method, and crude extraction of enzymes was carried out. Molecular weight of laccase was determined as 66 kDa and that of manganese peroxidase was 60 kDa. Capacity of crude enzymes to degrade polyethylene was also determined. By observing these results, we can conclude that P. simplicissimum may act as solution for the problem caused by polyethylene in nature.