Microbial Degradation of Polyethylene carry Bags of Low Density

Abstract

Now management of plastic waste has emerged as a major challenge; biodegradation of LDPE can become an alternative solution to reduce polythene waste. The aim of study was to isolate low density polythene degrading microorganisms (bacteria and fungi) from soil of different landfill sites of Agra. 18 types of fungi and 5 types of bacteria were isolated from 10 different dumping sites of Agra. Out of 18 fungi only 2 fungi and only one bacterium exhibited maximum growth on screening medium and were selected for further degradation process. Selected fugal strains were identified as A. flavus and A.terreus and bacterial strain was identified as Bacillus subtilis by molecular characterization. The biodegradation of LDPE film was achieved using the isolated (A. flavus and A. terreus) and procured fungi (Penicillium chrysogenum and Phanerochaete chrysosporium)) and isolated bacteria (Bacillus subtilis) and procured bacteria (Brevibacillus borstelensis) were also used. Extent of degradation of LDPE film was analyzed through, Weight reduction method, SEM, FTIR and CO2 Analysis. Reduction in weight of LDPE film confirmed its biodegradation. Changes in the surface of LDPE film before and after biodegradation such as corrosion, cracks, cavities and fissure etc was analyzed by SEM. Modifications in the functional group confirmed that the chemical structure of LDPE film changed due to the biodegradation as monitored by the FTIR tool. Evolution of CO2 showed effective mineralization after biodegradation. This study reports for first time the use of consortium of fungi Aspergillus flavus, Aspergillus terreus, Penicillium chrysogenum and Phanerochaete chrysosporium and consortium of bacteria Bacillus subtilis and Brevibacillus borstelensis to increase the biodegradation of LDPE film. The maximum weight loss of LDPE was observed by consortium of isolated fungal species A. flavus and A. terreus 62.4% and 61.5 % after 9 months in soil and after 4 months in synthetic medium respectively and consortium of Bacillus subtilis and Brevibacillus borstelensis 39% after 9 months in soil and 42.2% after 4 months in liquid synthetic weight loss of LDPE. newline