Biodegradation characterization and mechanism of low-density polyethylene by the enriched mixed-culture from...

Plastic pollution poses significant ecological and health risks. In this study, we enriched microbial consortia from plastic-contaminated soil capable of degrading low-density polyethylene (LDPE) film over a 28-day incubation period. Using two kinds of enriched cultures, the mean film weight loss rate (WLR) of 0.27 ± 0.04 % (p < 0.01) was 9 times higher than the control. Scanning electron microscopy (SEM) revealed a average hole occurrence area of 0.67 ± 0.11 μm² in the topmost sample, while the control had no change. Fourier transform infrared (FTIR) revealed specific changes in hydrophilicity (increased by 5.70 ± 0.02 times) and crystallinity (decreased by 15.73 ± 3.26 %). Meanwhile, FTIR analyses including peak occurrence at 3741 cm^-1, carbonyl index and Lambert-Beer law calculations revealed moisture infiltration and predominant aldehyde carbonyl formation (88.69 % in total carbonyl). The results of high-throughput sequencing indicated Brevibacillus, Bacillus and Sporosarcina were dominate genera in the mixed-cultures, and PICRUSt2 implied they could use LDPE as the sole carbon source. Our study aims to provided theoretical basis driving plastic degradation and to mitigate plastic pollution based on microbial resource development.