Polycarbonate biodegradation by isolated molds using clear-zone and atomic force microscopic methods

The accumulation of dry waste containing synthetic polymers due to their resistance to microorganisms and other environmental factors has posed some serious problems to the environment in recent years. On the other hand, plastics constitute the foundations of economy as they are widely used in agriculture, constructions, packaging, health care and also medicine. The aim of this research was to investigate the role of different isolated fungi in the degradation of polycarbonate polymers. For this purpose, sampling was done using the garden soil and waste leachate from Isfahan Waste Management Organization. Samples were enriched in the liquid mineral salt medium supplemented with polycarbonate and then were transferred to the same medium solidified with agar to isolate and identify different fungi. Finally, their biodegradation activity was investigated with the help of clear- zone and atomic force microscopic (AFM) techniques, and also lipase and amylase production was tested. Among 15 isolated genera of mold fungi, Fusarium , Ulocladium , Chrysosporium and Penicillium showed biodegradation activity. According to the diameter of clear zone around the fungal colonies and also AFM results, the highest rate of degradation was related to Fusarium. Lipase activity of all isolated fungi was positive, but amylase activity of Ulocladium was negative. It can be concluded that some fungal strains such as Fusarium can be used for the biodegrada- tion of plastic materials as it leads to a very eco-friendly biodegradation process