Synergistic effect of Lactobacillus paracasei (T1–9) and Lactobacillus bulgaricus Dangxiong LB-III (DB–3) on Degradation of Biodegradable Plastics Poly(butylene Adipate- co -terephthalate)-Based Materials

The increasing use of poly(butylene adipate-co-terephthalate) (PBAT) poses potential ecological risks due to improper disposal and low biodegradability. Developing environmentally safe and efficient PBAT-degrading microorganisms remains a critical prerequisite. Here, a cocultivation of the Lactobacillus paracasei (T1-9) with Lactobacillus bulgaricus Dangxiong LB-III (DB-3) significantly enhanced the degradation of PBAT-based films, achieving a weight loss of 29.22 ± 0.21 wt % for PBAT/CaCO₃ composite in the FT coculture system and 14.64 ± 0.83 wt % for PBAT/TPS blend in the FD coculture system over 42 days. Enzyme activity results demonstrated that the FT and FD coculture system significantly enhanced the secretion and activity of lipases and cutinases, facilitating the cleavage of ester bonds and increasing surface hydrophilicity and microcrack formation. Meanwhile, LC-QTOF-MS results validated the presence of intermediate products. This work highlights the promising potential of probiotic coculture systems to enhance the biodegradation of PBAT-based materials, offering a novel strategy for sustainable polymer waste management.