ISOLATION AND CHARACTERIZATION OF POLYTHENE – DEGRADING MICROORGANISMS FROM POLYTHENE DUMPSITE SOILS IN AKURE, ONDO STATE, NIGERIA

Abstract

Microbial degradation of polythene obtained from the polythene dumpsite at Ondo State Integrated Wastes Recycling and Treatment Project Igbatoro Road Akure, Nigeria was carried out under static in – vitro condition. Soil samples at depth of approximately 10 cm were collected from different locations in the dumpsite. Soils were analysed for mineral composition and physicochemical characteristics. The fungal isolates were screened for polythene degradation using minimal salt medium (MSM) containing polythene as sole source of carbon and nitrogen for their ability to degrade polythene. The isolates that grew on MSM were used for the biodegradation study. Gravimetric analysis and Fourier Transform Infrared Spectroscopy (FTIR) were used to monitor the biodegradation of the polythene strips. Microorganisms associated with the waste dumpsite soils were isolated and identified. Nine bacteria (Bacillus cereus, Proteus vulgaris, Pseudomonas aeroginosa, Escherichia coli, Enterobacter sp, B. sphaericus, Staphylococcus aureus, S. epidermidis and Streptococcus pneumoniae) and seven fungi (Aspergillus flavus, A. nidulans, Penicillium chrysogenum, Mucor mucedo, Eurotium repens, A. fumigatus and Rhizopus stolonifer) were isolated and characterized. Mean microbial count ranges from 1.5 x 107 cfu/g to 2.1 x 107 cfu/g (bacteria) and 1.4 x 107 sfu/g to 8.2 x 108 sfu/g (fungi). Individual weight loss was observed in polythene strip cultured with P. chrysogenum (1%), E. repens (1%) and A. nidulans (2%). The changes observed in the FTIR spectra especially the polythene sample strip inoculated with A. nidulans confirm the significant role of fungi in polythene degradation hence, can be used in the treatment of polythene in the environment which is a cheap eco-friendly method. Hence, fungi namely A. nidulans, E. repens and P. notatum play significant role in the biodegradation of polythene. Incorporating these microorganisms in polythene waste management will help provide a cleaner environment