Microbial degradation of polyethylene (PE)

Abstract

Thirty two bacterial isolates were obtained from soil by soil burial method followed by enrichment culture technique in film culturing (FC) media. Bacterial isolates differing in morphology were selected, purified and maintained at 4°C. Thirty % of these isolates were found to be Gram negative and 50% showed positive starch hydrolysis test and were screened for their ability to degrade Low Density Polyethylene (untreated, UV and heat strips) in film culturing media and percent weight loss of polyethylene after 4th week was determined. Among various isolates, highest degradation was by Is 3, Is 22 and Is 31 to the range of 25–27%, of UV treated polyethylene strips. High temperature (40°C), was found to enhance degradation rate of polyethylene more effectively by 24–28% compared to low temperature at 30°C (18–21%). Degradation of treated polyethylene strips (UV, heat steam) was up to 4% by compost treatment as studied by using CO₂ evolution, an estimation tool to analyze % degradation. Bacterial activity was also affected by various environmental factors like sunlight, temperature, oxygen etc.