Biodegradation of polyethylene via complete solubilization by the action of Pseudomonas fluorescens, biosurfactant produced by Bacillus licheniformis and anionic surfactant

BACKGROUNDLong hydrocarbon (approximate to CH2) chain, absence of polar bonds and highly hydrophobic nature of polyethylene, make it one of most difficult environmental pollutants to degrade. In the present study, commercially available polyethylenes were treated with biosurfactant produced by Bacillus licheniformis, anionic surfactant and bacterially treated with Pseudomonas fluorescens in different combinations to achieve higher biodegradation. RESULTSPolyethylene was slightly oxidized by P. fluorescens in the first month and the oxidation of polyethylene induced by the biosurfactant during the second month was enhanced by the presence of lower amounts of carbonyl groups as observed in FTIR analysis. During the third month, highly oxidized polyethylene was entirely solubilized by the action of 10% SDS forming two-layered liquid consisting of yellow oil-like liquid as upper layer and an aqueous colourless lower layer. Biodegradable aliphatic acids, alcohols and short hydrocarbon molecules of 10-30 carbon chains were identified by GC-MS analysis in the aqueous solution. Weight loss of 7.13 0.05% was also observed in polyethylene samples which were treated with SDS in the first month, then bacterially treated with P. fluorescens in the second month and finally treated with biosurfactant in the third month. CONCLUSIONSPolyethylene became biodegradable after complete solubilization in water by treating consecutively with Pseudomonas fluorescens in the first month, then with biosurfactant in the second month and finally treating with 10% sodium dodecyl sulphate (SDS) at 60 degrees C for the third month. Simultaneous treatment of polyethylene with P. fluorescens, surfactant and biosurfactant has a tremendous effect on the oxidation and biodegradation of polyethylene. (c) 2017 Society of Chemical Industry