[Screening and Identification of Polyvinyl Chloride-degrading Bacteria and Its Degradation Characteristics].

Abstract

Polyvinyl chloride （PVC） has been shown to be degraded by some insect larvae； however, research is scarce on degrading bacteria. This study revealed that Zophobas atratus larvae were able to keep a higher survival rate only when taking in PVC and reached up to 72.33% within 30 d. Fourier transform infrared spectroscopy （FTIR） and thermogravimetric analysis （TGA） showed that the peak values of the major functional groups of PVC in the frass changed significantly, and the thermal stability decreased, indicating that PVC biodegraded in the gut of Z. atratus. Based on these, three PVC-degrading bacteria were isolated from the gut contents of the larvae with PVC as the only carbon source in the culture medium for selection, which were identified to be Enterococcus faecalis, Enterobacter hormaechei, and Bacillus subtilis. The degradation test of PVC showed that C5-1 had the greatest degradation efficiency among the three strains, which resulted in the weight loss of （6.19 ± 0.14） mg, and the water contact angle （WCA） decreased by 9.4° within 50 d, effectively improving the hydrophilicity of PVC. In conclusion, the strain C5-1 isolated from the gut of Z. atratus larvae showed the high potential to be applied to the biodegradation of PVC plastics.