Biodegradable plastic-degrading enzyme from Pseudozyma antarctica: cloning, sequencing, and characterization

Pseudozyma antarctica JCM 10317 exhibits a strong degradation activity for biodegradable plastics (BPs) such as agricultural mulch films composed of poly(butylene succinate) (PBS) and poly(butylene succinate-co-adipate) (PBSA). An enzyme named PaE was isolated and the gene encoding PaE was cloned from the strain by functional complementation in Saccharomyces cerevisiae. The deduced amino acid sequence of PaE contains 198 amino acids with a predicted molecular weight of 20,362.41. High identity was observed between this sequence and that of cutinase-like enzymes (CLEs) (61-68 %); therefore, the gene encoding PaE was named PaCLE1. The specific activity of PaE against emulsified PBSA was 54.8 +/- 6.3 U/mg. In addition to emulsified BPs, PaE degraded solid films of PBS, PBSA, poly(epsilon-caprolactone), and poly(lactic acid).