Characterizing biodegradation of PLA and PLA-g-AA/starch films using a phosphate-solubilizing bacillus species.

The use of PLA and PLA-g-AA/starch as materials for the controlled release of encapsulated PSB was evaluated. The results showed that the bacterium degraded both the PLA and the PLA-g-AA/starch composite films, resulting in cell release. Severe disruption of the film structure occurred after incubation for 60-90 d. The PLA-g-AA/starch (20 wt.-%) films were more biodegradable than those made of PLA and also suffered a more pronounced decrease in molecular weight and intrinsic viscosity. Although blending of starch appeared to enhance the biodegradability of the PLA films, the pattern of degradation was quite similar for both types of films. The rate of cell release depends on the biodegradability of the film.