Pretreatment with an esterase from the yeast Pseudozyma antarctica accelerates biodegradation of plastic mulch film in soil under laboratory conditions

The yeast Pseudozyma antarctica secretes a concentrated biodegradable plastic (BP)-degrading enzyme when cultivated with xylose. Treatment with the culture filtrate reduced the puncture strength of commercial BP mulch films. After burying the film in soil, the residual amount of solid film was reduced significantly, and none was recovered after 5 weeks. The dynamics of soil fungal communities were analyzed weekly after burying the film using 18S rDNA polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) profiling of soil DNA. In the soil containing enzyme-treated film, the native community essentially recovered within 24 weeks. In comparison, the untreated solid film remained in the soil for 12 weeks and the response of the soil-fungal community was relatively slow; it had not recovered within 24 weeks.