LAUSR

This work studied the biodegradative activity of Pseudomonas geniculata WS3 and Stenotrophomonas pavanii CH1, PLA-degrading bacteria, on films with different ratios of polybutylene succinate (PBS)/polylactic acid (PLA), in submerged cultures. Effects of PBS, dicumyl peroxide (DCP) and 2-hydroxypropyl-3-piperazinyl quinoline carboxylic acid methacrylate (HPQM) of in situ compatibilized PBS/PLA blends were also examined under soil burial biodegradation at mesophilic and thermophilic conditions. The results from the submerged experiments showed that the weight loss of PBS/PLA blends increased with increasing PBS content. All blending ratios of PBS/PLA were more degraded by P. geniculata WS3 than S. pavanii CH1. After soil burial, PBS/PLA films with 40/60 wt% showed higher biodegradation than those with 20/80 wt% with or without P. geniculata WS3 inoculation. However, the biodegradation of PBS/PLA blends inoculated with P. geniculata WS3 was higher than that of the uninoculated treatment. The addition of DCP in PBS/PLA blends decreased the biodegradation and weight loss. Unexpectedly, the degree of biodegradation and weight loss of PBS/PLA at a ratio of 20/80 wt% with DCP added were higher than that of PBS/PLA at a ratio of 40/60 wt% with DCP added. The addition of HPQM, showing antibacterial properties, decreased the biodegradation of PBS/PLA blends by 1.4 to 1.8-fold compared to those without HPQM addition. It could be concluded that the inoculation of P. geniculata WS3 mainly promoted the biodegradation of PBS/PLA blends under mesophilic condition. However, the addition of DCP and HPQM decreased the biodegradation of the PBS/PLA blends.