Biodegradation of polyethylene glycol and low-density polyethylene by bacteria isolated from Urdaneta City Sanitary Landfill, Pangasinan.

Abstract

Plastic pollution is a major problem due to the recalcitrant nature of plastics. The most common plastics include polyethylene, which includes polyethylene glycol (PEG) and low-density polyethylene (LDPE), which is often used to make plastic bags and containers such bottles and used for a variety of applications. Bacteria were isolated from Urdaneta City sanitary landfill, Pangasinan and screened for PEG degradation. To our knowledge, this is the first research initiative conducted for this landfill for prospecting plastic degrading bacteria. Four LDPE-degrading bacteria obtained using selective culture isolation were evaluated through a modified Sturm test. The differences in the amount of CO2 gas that evolved from the control and treatment setups were determined to be significant, indicating that the CO2 gas in the treatment bottles may be attributed due to the degradation of the LDPE by the bacterial isolates. Through 16s rRNA gene sequence analysis, the bacteria, namely B6IVA, B6IVB, C4V and E6XIII were identified as Xanthobacter flavus, Enterobacter xiangfangensis, Escherichia hermannii, and Azospirillum fermentarium respectively. Among the four, only Xanthobacter flavus has been previously reported to degrade plastics while the remaining bacterial isolates were previously not linked to PEG nor LDPE degradation.