0
Article ? AI-assigned paper type based on the abstract. Classification may not be perfect — flag errors using the feedback button. Tier 2 ? Original research — experimental, observational, or case-control study. Direct primary evidence. Environmental Sources Sign in to save

Bacteria isolated from soil degrade low-density polyethylene for growth and polyhydroxyalkanoate synthesis

Journal of Environmental Management 2025 Score: 38 ? 0–100 AI score estimating relevance to the microplastics field. Papers below 30 are filtered from public browse.
Intira Khumthong, Intira Khumthong, Wilailak Siripornadulsil, Surasak Siripornadulsil

Summary

Researchers isolated bacteria from plastic waste-contaminated soils and characterised their ability to degrade low-density polyethylene (LDPE), finding that after 16 weeks a bacterial consortium and Chitinophaga oryzae NT1-2 achieved weight losses of 21.97% and 16.14% respectively. FTIR analysis detected new carbonyl functional groups on degraded LDPE surfaces, alkane hydroxylase and alcohol dehydrogenase activities were quantified across strains, and the LDPE-degrading bacteria were also shown to synthesise polyhydroxyalkanoate (PHA), with C. oryzae NT1-2 producing the highest PHA yield of 26.27 mg/g-glucose.

Polymers

The low-density polyethylene (LDPE) used in food packaging contributes significantly to the environmental accumulation of microplastics and plastic waste. The aim of this study was to identify and characterize bacteria from plastic waste-contaminated soils that degrade LDPEs. After 16 weeks of degradation, the greatest percentage of LDPE weight loss were achieved with the bacterial consortium and Chitinophaga oryzae NT1-2 (21.97 ± 8.81 % and 16.14 ± 0.46 %, respectively). After bacteria were exposed to LDPE, numerous new functional groups, including aldehydes, ketones, and carboxylic acids, were identified by Fourier transform infrared spectroscopy (FTIR) analysis, while field emission scanning electron microscopy showed that the treated LDPE film surface had more grooves and cracks and was rougher than the control LDPE film surface. The highest total (1781.20 ± 42 U/min/mL) and specific (2.53 ± 0.06 U/min/mg protein) activities of alkane hydroxylase were detected in Bothriochloa intermedia MK2-8, whereas the total and specific alcohol dehydrogenase activities of the MK2-8 strain were 95.57 ± 4.16 U/min/mL and 0.14 ± 0.01 U/min/mg protein, respectively. In Pseudomonas aeruginosa CB1-2, the highest total and specific lipase activities were 10.00 ± 0.20 U/min/mL and 0.10 ± 0.03 U/min/mg protein, respectively. These LDPE-degrading bacteria produced polyhydroxyalkanoate (PHA), with C. oryzae NT1-2 giving the highest yield of 26.27 ± 8.40 mg PHA/g-glucose. Thus, bacteria isolated from plastic contaminated soil possess the capability to enzymatically degrade LDPE and convert it into the PHA biopolymer, thereby contributing to environmental sustainability and resource efficiency.

Sign in to start a discussion.

Share this paper