BIODEGRADATION OF LOW DENSITY POLYETHYLENE BY BACTERIA ISOLATED FROM OIL CONTAMINATED SOIL
|R.Kavitha*, Anju k. Mohanan, and V.Bhuvaneswari.
Department of Biochemistry, Biotechnology and Bioinformatics, Avinashilingam Institute for Home science and Higher education for women, Coimbatore-641043, India
|Corresponding Author: R.Kavitha, E-mail: [email protected]|
|Received: 05 June 2014 Accepted: 28 June 2014|
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Plastics are composed of petroleum based materials that are resistant to biodegradation. The widespread applications of plastics are not only due to their favourable mechanical and thermal properties but also mainly due to the stability and durability. The most commonly used non-degradable solid waste is polythene which is a linear hydrocarbon polymers consisting of long chains of the ethylene monomers. Most shopping bags are made from polyethylene a chemically inert compound consisting of carbon and hydrogen. Burning of this plastic waste and burying of the plastics releases harmful toxic material which is a major pollutant in environment. Degradation of waste plastics through microorganism use represents one of the alternatives to deal with such problems. The present study aims to investigate the biodegrading potentials of bacteria isolated from oil contaminated soil. The extents of biodegradability of the untreated low density polyethylene film by the isolated bacterial strains were assessed in vitro in the medium containing polyethylene film as the sole carbon source. After 30 days of incubation period, the biodegradation of the polyethylene film was measured in terms of weight loss and physicochemical analysis by scanning electron microscopy and fourier transform infra red spectroscopy. The hydrophobicity of the bacterial isolates was evaluated by BATH test. The results depict that both the isolates were hydrophobic and were able to grow in a medium containing untreated polyethylene as a sole carbon source. Incubation of untreated polyethylene with bacterial isolate 1 and 2 (30 days, 37º c) reduces its mass by 1.29% and 1.3 % respectively. The smooth surface of the untreated polyethylene film became eroded as a result of biodegradation. The FTIR spectra showed changes in the chemical properties of the polyethylene film due to the biodegradation by the bacterial isolates.