ISOLATION OF MICROORGANISMS ASSOCIATED WITH DEGRADATION OF PLASTIC AND POLYTHENE IN SOIL

Biodegradation of polythene bags (PB) and plastic cups (PC) in soil were studied for five weeks using the weight loss method. The results revealed that weight loss begins after the third week, the rate of biodegradation was observed to be minimal and ranged between 2.1 2.4% for PB and 0.17 – 1.2% for PC. Heterotrophic bacterial count ranged between 2.3X10 4 – 6.8 X 10 4 cfu/g for PB and 2.3X104 – 5.4 X 104 cfu/g for PC, while fungal count revealed 2.2 x 10 4 – 8.9 x 10 3 cfu/g for PB and 2.3 X 103 – 8.3 X 103 cfu/g for PC. The following microorganisms were found to be associated with biodegradation of PB and PC in soil: Streptococcus species, Staphylococcus species, Pseudomonas species, Micrococcus species and Aspergillus species. Micrococcus species recorded the highest incidence for both PB and PC amongst the bacterial isolates whereas the fungus, Aspergillus niger occurred frequently for both PC and PB. The results revealed the role of microorganisms in the biodegradation of both PB and PC although at a slow rate.