Biodegradation of poly(butylene succinate-co-butylene adipate) by Aspergillus versicolor

We have studied the biodegradation behaviour and mechanism of poly(butylene succinate-co-butylene adipate) (PBSA) by Aspergillus versicolor isolated from compost. Analysis of weight loss showed that more than 90% of PBSA film was assimilated within 25 days. There was also a rapid decrease in molecular weight characterized by gel permeation chromatography (GPC). A number of cracks and round holes were observed on the eroded film surface through scanning electron microscopy (SEM). These results revealed the fast degradation of PBSA film in the presence of A. versicolor. As a comparison, the hydrolysis of the same sample was much slower in the corresponding abiotic medium. The analyses of 1H NMR and differential scanning calorimetry (DSC) indicate that the preferred degradation takes place in the adipate units and the succinate units are relatively recalcitrant to A. versicolor.