Polyethene Degradation Efficacy of Autochthonous Microbes from a Refuse Dump in Port Harcourt, Rivers State, Nigeria

Abstract

Plastic waste has accumulated significantly in the environment as a result of urbanization and industrialisation. Due to their wide range of uses, plastics are present in many facets of our lives. This study was aimed at assessing the polyethene degradation potency of bacteria and fungi from a refuse dump in Amadi-Ama, Portharcourt Rivers State, Nigeria. The microorganisms were isolated from plastic polyethene wastes deposited in the soil of a refuse dump in Amadi-Ama, Port Harcourt, Rivers State. Experiments were conducted under laboratory conditions to degrade virgin polyethene. The degradation pattern of the polyethene by ethylene-utilising bacteria and fungi in soil and mineral salt medium from the study area followed the same pattern as that of the standard control. The Brucine method was used for nitrate concentration determination in the sample. The APHA 3111 B method was used for the determination of Potassium, Sodium, Magnesium and Calcium concentrations. Results for fungal count were determined after 48 hours of incubation. The mean polyethene weight at the 1st and 35th days in the soil from the study area was14.204± 0.00 and 10.033 ± 0.09 after being acted upon by the ethylene-utilising bacteria, while it was 14.204± 0.00 and 8.580 ± 0.32 after being acted upon by the ethylene-utilising fungi. The mean polyethene weight at the 1st and 35th days in the mineral salt medium from the study area was37.319± 0.86 and 34.467 ± 1.04, respectively, after being acted upon by the ethylene-utilising bacteria, while it was 37.470± 1.05 and 28.184 ± 0.25 after being acted upon by the ethylene-utilising fungi. The mean polyethene weight at the 1st and 35th days in the standard control was137.326± 0.00 and 119.85 ± 1.43 after being acted upon by the ethylene-utilising bacteria, while it was 137.326± 0.00 and 106.416 ± 4.00 after being acted upon by the ethylene-utilising fungi. The percentage change in the degradation pattern of the polyethene by ethylene-utilising bacteria and fungi in soil and mineral salt medium from the study area followed the same pattern as that of the standard control. In conclusion, bacteria and fungi species degraded the polyethene from the refuse dump in Amadi-Ama, Portharcourt Rivers State, Nigeria. The polythene degradation capability of the bacteria was higher than that of the fungi in the refuse dump. The microorganisms can be enhanced in further bioengineering studies to boost their degradation efficacy, which will serve as a viable polyethene pollution control option.