Biodegradation of Polythene by Fungi Isolated from Waste Disposal Areas in Gusau Metropolis

Indiscriminate disposal of polyethylene materials have become a regular practice among developing nations of Africa, especially in Nigeria. This has resulted in environmental pollution. Their accumulation can be hazardous and can cause various environmental problems. This work was aimed at studying the biodegradation of polythene by fungi isolated from waste disposal areas in North West, (Zamfara state) Nigeria. A total of twenty soil samples were collected from four different locations, such as waste disposal areas, hospitals, roadsides, and petrol pumps station. Spread plate method was carried out on Potato dextrose agar for the growth of fungi. A total 7 fungi were isolated from different areas. The fungal count in hospital ranged from 2 × 10-2 -39 × 10-2 cfu/mL, roadsides ranged from 3 × 10-2 - 70 × 10-2 cfu/mL, petrol pump ranged from 3 × 10-2 - 100 × 10-2 cfu/mL, and waste disposal areas ranged from 2 × 10-2 - 50 × 10-2 cfu/mL. The fungal species associated with the polythene materials were identified as, Aspergillus flavus, Aspergillus fumigatus, Aspergillus nidulans, Aspergillus lentulus, Aspergillus niger, Trichoderma harzianum, Histoplasma capsulatum. The fungal isolates were screened for polyethylene degradation using mineral salt medium containing polyethylene as sole source of carbon and nitrogen for their ability to degrade polyethylene for the period of 2 months. Efficacy of the fungi in degradation of polythene were analyzed using liquid culture method. Among the fungal species Aspergillus flavus degraded at 66.6%, Aspergillus fumigatus degraded 44.4% of polythene in a period of 2 months. This work reveals that the Aspergillus flavus and Aspergillus fumigatus posses greater potential to degrade polythene when compared with other fungi. The use of genetically engineered organisms should be adopted so that they can produce upgraded metabolic enzymes to degrade polythene.