Biodegradation of Plastics using Bacteria Isolated from Wastes Dumping Soil within Sokoto Metropolis

Plastic pollution, particularly polyethylene, has become a significant environmental concern worldwide due to its non-biodegradable nature. In urban areas, waste dumping sites serve as critical hotspots for the accumulation of plastic waste. The microbial degradation of polyethylene offers a promising solution to mitigate this environmental challenge. This study investigates the biodegradation potential of polyethylene plastics by bacteria isolated from the soil of waste dumping sites in Sokoto Metropolis, Nigeria. Soil samples were collected from three waste dumping sites within the metropolis, and bacteria were isolated using standard microbiological techniques. The isolates were screened for their ability to degrade polyethylene by assessing their growth and activity in minimal salt medium (MSM) supplemented with polyethylene strips as the sole carbon source. Key parameters, including pH and temperature, were analysed, and the degradation rate was monitored through weight loss of polyethylene discs, optical density readings, and changes in microbial growth at different time intervals (day 0 to day 28). The results indicated that isolates like Bacillus subtilis, Bacillus cereus, Pseudomonas aeruginosa, Pseudomonas putida and Arthrobacter citreus exhibited significant biodegradation activity, with weight loss of polyethylene ranging from 10% to 50% after 28 days of incubation. The bacterial isolates showed optimal growth at a temperature of 37°C and at a pH of 7.0. Isolates were identified using 16S rRNA gene sequencing, revealing a diverse range of bacteria, including species of Bacillus and Pseudomonas, known for their plastic-degrading capabilities. The findings contribute to the growing body of knowledge on sustainable waste management practices and underscore the importance of harnessing local microbial resources in the fight against plastic pollution. The biodegradation potential of these bacteria could be further explored for bioremediation strategies to mitigate plastic waste in urban environments.