Degradation of Polyethylene Using Bacteria from Waste Dump Sites in Obio/Akpor Local Government Area in Rivers State, Nigeria

Abstract

All around the world today, different types of plastics are used for packaging materials, especially in form of low density polyethylene (LDPE). The aim of the study was to degrade polyethylene using bacteria from waste dump sites in Alakahia and Ogbogoro of Obio/ Apkor Local Government Area, Rivers State. Soil samples were randomly collected from Alakahia and Ogbogoro dump sites in Obio/Apkor Local Government Area, in Rivers state. Polyethylene degraders were determined using microscopy and weight loss methods. The total heterotrophic bacterial counts recorded were 3.03 x 106 CFU/g and 1.12 x 106 CFU/g for Ogbogoro and Alakahia samples. The total count of Pseudomonas recorded were 5.0 x 104 CFU/g and 4.9 x 104 CFU/g for Ogbogoro and Alakahia sample. There was no significant difference (P ≤ 0.05) within the counts of the samples. The bacteria isolated from the soil collected from the dumpsites were Bacillus sp, Klebsiella sp, Pseudomonas sp, Staphylococcus sp, Serratia sp, Escherichia coli, Shigella sp, Salmonella sp. The identified bacteria were Pseudomonas proteolytica NR025588.1, Pseudomonas aeruginosa CP0296051 and Bacillus circulans CP026031.1. From the result of the degradative ability by the individual microorganism using weight loss measurement, Pseudomonas aeruginosa CP0296051 showed a greater percentage of degradation of polyethylene of 5% to 27.03% (after 150 days) followed by Pseudomonas proteolytica NR025588.1 which recorded percentage degradation of 6.0% to 23.28% (after 150 days) while Bacillus circulans CP02603.1 recorded the least percentage of 5% to 19.9% (after 150 days). The result of degradative potential of the microbes in consortium set ups showed that the consortium of Pseudomonas aeruginosa CP0296051 and Bacillus circulans CP02603.1 (B8+B6) showed the highest degradation potential producing degradation percentage range of 8.7 to 46.80% after 150 days of the study and the least degradation potential of polyethylene was observed in Pseudomonas aeruginosa CP0296051 and Pseudomonas proteolytica NRO255SS.1 (B6+B3) with the percentage range of 5% to 27.03% after 150 days. From the study, Pseudomonas sp, Bacillus sp and their consortium showed higher potential to degrade low density polyethylene (LDPE) hence the prospect in remediation of polyethylene.