Assessment of Some Potential Plastic Degrading Microbes in Katsina, North Western Nigeria

Abstract

Microorganisms play a significant role in biological decomposition of materials, including synthetic polymers in natural environments. This research was aimed to assess some potential plastic-degrading microbes in Katsina. Soil samples from four different locations of about 15,000 meters apart were used for this study. Portions of the soil samples were dried, ground, and sieved through a 2mm sieve for physico-chemical characterization. The soil temperature ranged from 26.30°C to 29.60°C, pH 5.67 to 6.26, % Nitrate 0.54 to 0.97, % Phosphates 2.03 to 3.83, % organic carbon 1.71 to 3.27, % organic matter 1.97 to 9.43, and % moisture content 7.13 to 16.22. Isolation and the enumeration of bacteria and fungi were done using nutrient agar and potato dextrose agar, respectively. The total populations of bacteria ranged from 1.69 x 10⁵ to 2.94 x 10⁵ CFU/g in the soil, while the fungi ranged from 1.60 x 10⁴ to 8.35 x 10⁴ CFU/g in the soil. The capability of microbial isolates to biodegrade ground polyethylene bags and plastic bottles was tested weekly. Microbes identified include Staphylococcus aureus, Streptococcus lactis, Bacillus subtilis, Diplococcus sp. and Pseudomonas sp. Eight degrading fungal species identified following fungal colony and color include Alternaria alternata, Aspergillus niger, Aspergillus flavus, Aspergillus ornatus, Aspergillus candidus, Aspergillus nidulans, Aspergillus terreus, and Rhizopus stolonifera. It can be concluded that the soil around Kofar Sauri, Kofar Marusa, Kofar Guga, and Kofar Kaura of Katsina metropolis contains some plastic-degrading microbial species. Hence, further investigation using GC-MS to analyze the microbial enzymes or organic acids in degradation of the polythene and plastics in an eco-friendly way is recommended.