Degradation of microplastics in artificially polluted soil by bacterial and fungal isolates originating from landfill leachate

Abstract

The spread of microplastics in agricultural soil may harm the soil ecosystem and reduce its fertility. This research aims to assess the application of bacterial and fungal isolates from landfill leachate separately so that microplastics in the soil can be degraded. This experiment utilized sterilized soil that was artificially polluted with microplastics made of polyethylene and polypropylene. The treatment involved two bacterial strains (CY1-PE(1) and CC1-10) and two fungal strains (CY3-4FPE(I) and CC2-2F), which were previously isolated from waste leachate. Microplastic-containing soil treated with these microorganisms was incubated, and the microplastics were weighed after 14, 28, 42, and 56 days of incubation. The results showed that polyethylene microplastics were degraded progressively for 56 days by 2.54%, 2.38%, 1.90%, and 1.59%; likewise, polypropylene microplastics by 3.81%, 3.17%, 7.62%, and 7.30%, by CY1-PE(1), CC1-10, CY3-4FPE(I), and CC2-2F, respectively. In addition, changes in the surface appearance of the microplastics, such as the presence of surface irregularities, were observed using a light microscope after incubation. These results were supported by a decrease in pH during incubation. In conclusion, these four microorganisms demonstrated significant potential for development as agents to degrade polyethylene and polypropylene microplastics in soil environments.