Microbial consortia for multi-plastic waste biodegradation: Selection and validation

The accumulation of plastic waste in the environment poses significant ecological and health risks. This study evaluates the effectiveness of microbial consortia in degrading various types of plastics, including low-density polyethylene (LDPE), low linear-density polyethylene (LLDPE), polyethylene terephthalate (PET) and polystyrene (PS). Qualitative enzyme assays for esterases and ligninases, which are related to plastic biodegradation, were conducted in five microbial strains. Four microbial consortia, combining bacterial and fungal strains, were assembled based on the enzyme profile of their components and evaluated for their ability to degrade both virgin and recycled plastics. The results showed that consortia C2 (Bacillus subtilis RBM2, Fusarium oxysporum RHM1, and Alternaria alternata RHM4) and C4 ( Bacillus subtilis RBM2 and Pseudomonas alloputida REBP7) exhibited the highest biodegradation efficiency, particularly achieving significant weight loss in recycled LDPE, virgin LLDPE and recycled PET. The biodegradation was further confirmed by FTIR analysis, which revealed changes in the chemical composition and functional groups of the treated plastics, indicating microbial interaction and degradation. This study underscores the potential of microbial consortia in addressing plastic pollution, highlighting the importance of strategic consortia design based on enzymatic profiles and plastic colonization capabilities. These promising results suggest that further optimization of microbial consortia could offer a viable solution for large-scale plastic waste management.