This work was focused on the possibility of accelerating the biodegradation process of low density polyethylene (LDPE). Comparative studies, between the properties of untreated LDPE pieces and those exposed to UV irradiation and nitric acid plus microbial culture treatment, were performed. The LDPE pieces were irradiated by UV light (254 nm wavelength) for 250 h and incubated with nitric acid (99.0%) at 80 degrees C for 6 days. These pretreated LDPE pieces were used as sole carbon source in mineral salt medium and inoculated with the Fusarium sp. AF4, isolated from soil. The efficiency of the LDPE degradation depended on the growth phase in pure cultivation of the fungus. The changes in the structural properties of LDPE film because of UV-nitric acid and microbial treatment were determined by Fourier transform infrared spectroscopy (FTIR). It was observed that in case of UV and nitric acid treated LDPE, peaks appeared at 1710 cm(-1) and 831, which were then reduced to 1708 cm(-1) and 830 after microbial treatment, indicating breakdown of polymer chain. In this study, it was observed that a synergistic effect of UV-nitric acid and microbial treatment induced oxidation reaction that enhanced and accelerated the biodegradability rate of LDPE pieces. (c) 2007 Wiley Periodicals, Inc.