Mangrove‑derived halophilic microbiome as a biocatalyst for polyethylene terephthalate (PET) microplastic breakdown

Mangrove ecosystems are productive coastal habitats that provide important services, including shoreline stabilization, nutrient cycling, and nursery grounds for diverse marine species. Microplastics may represent a threat to many mangrove ecosystems. One of the most significant types of plastics is polyethylene terephthalate (PET), which is notable for its durability and potential to cause serious ecological damage. The use of halophilic and halotolerant microbes offers a promising approach for removing these pollutants in saline environments like mangroves. In this study, a halophilic and halotolerant consortium capable of PET degradation was isolated. This bacterial-fungal consortium, dominated by Methyloligella (32.54%), Truepera (12.25%), and Saccharomyces, showed PET degradation activity under 5% (w/v) NaCl conditions. It achieved a 15.5 ± 0.71% PET degradation efficiency within 50 days, accompanied by a maximum CO₂ concentration rate of 458 ppm. Physicochemical investigations, including Scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and Thermal-gravimetric analysis (TGA), confirmed surface erosion, alterations in chemical bonds, and a higher rate of thermal degradation, respectively. Moreover, Gas chromatography-Mass spectrometry (GC-MS) exhibited the formation of alkanes as PET degradation products. Given the ecological importance of mangrove ecosystems and their increasing exposure to microplastic contamination, these findings demonstrate that this consortium shows potential for PET degradation and could serve as a viable option for bioremediation in saline ecosystems.