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چکیده
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Every year, human activities introduce large amounts of synthetic plastics into the environment. Forasmuch as, decomposition of the plastic derivatives is very difficult and time consuming, it is essential to eliminate these pollutants using different methods. Bioremediation, is suitable option, because of the low cost and environmentally safe. In this research, degradation of low-density polyethylene (LDPE) was investigated by Stenotrophomonas sp. and Alcaligenaceae bacterium, isolated from Hamedan landfill soil. After identification by 16srDNA primers, their abilities to form biofilm and biodegradation of polyethylene sheets treated with ultraviolet rays were examined by Fourier transform infrared (FTIR), SEM and Gas Chromatography–Mass Spectrometry (GC-MS). Using media contain polyethylene) after and before addition of bacteria), toxicity test was conducted by measuring the germination index, root and hypocotyl length of Lactuca sativa seed. After 3 months, 10.13% weight loss of LDPE achieved through strain Stenotrophomonas sp. degradation. Both strains had high biofilm formation capacity, confirmed by Electron microscope images and FTIR analysis. GC-MS confirmed the presence of the end-product of LDPE degradation (Pentacosane, Hexacosane, and Octadecane). Both, Stenotrophomonas sp. and Alcaligenaceae bacterium had significant detoxification ability, however presence of in LDPE media (without bacteria) prevented the seed germination.
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