【Objective】Poly(butylene adipate-co-terephthalate) (PBAT) serves as a crucial alternative to conventional plastic mulch films. However, the presence of aromatic chains renders PBAT more recalcitrant to biodegradation compared to other biodegradable plastics (e.g., polylactic acid). Moreover, there are limited microbial resources exhibiting efficient PBAT degradation capabilities.【Method】This study employed a soil-compost enrichment approach to screen high-efficiency PBAT-degrading microbial strains. Microbial consortia were enriched at 60 ℃ under thermophilic composting conditions using PBAT as the sole carbon source, yielding six candidate strains (designated B1-B6). Degradation efficacy was comprehensively evaluated through mass loss, surface morphology analysis, and water contact angle measurements.【Result】Strain B3 demonstrated superior PBAT degradation efficiency, achieving a 17.85%±11.22% mass loss within 7 days, exceeding currently reported values for PBAT-degrading microorganisms. Atomic force microscopy (AFM) analysis revealed significant surface modification across all treatment groups, with B3-exposed PBAT exhibiting the most pronounced surface roughness (Ra = 44.84±26.48 nm). Concurrent physicochemical characterization showed a 15.6° reduction in water contact angle, collectively indicating substantial polymer matrix alteration. Taxonomic identification through 16S rRNA gene sequencing classified strain B3 as?Parageobacillus toebii.?In addition, characterization of the degradation performance of the mixed microbial consortium (designated as MIX) showed that MIX achieved a PBAT degradation rate of 12.48%±1.11%. Although the impact on surface roughness of PBAT was relatively minor, MIX induced the most significant changes in water contact angle, indicating a pronounced degradation effect. High-throughput 16S rRNA sequencing analysis revealed that, at the species level, the dominant strain within the MIX consortium was Parageobacillus toebii, accounting for 98.50% of the population. Other minor constituents included Aeribacillus pallidus (1.45%), unclassified_g_Lactobacillus (0.01%), unclassified_c_Bacilli (0.02%), unclassified_k_norank_d_Bacteria (0.01%), and unclassified_g_Clostridium_sensu_stricto_1 (<0.01%). These findings suggest that the PBAT degradation capability of the MIX consortium is primarily attributed to Parageobacillus toebii. Through whole genome sequencing and Kyoto Encyclopedia of Genes and Genomes (KEGG) gene function annotation, it was identified that strain B3 possesses genes encoding enzymes relevant to PBAT degradation, including carboxylesterase, arylesterase, long-chain acyl-CoA synthetase, aldehyde dehydrogenase, alcohol dehydrogenase, and catechol 2,3-dioxygenase. Based on the above results, the potential degradation pathway of PBAT microplastics by the degrading microbes could be inferred as follows: (1) Initial hydrolysis: PBAT ester bonds are first cleaved by carboxylesterases, releasing intermediate products such as terephthalic acid and adipic acid. (2) Aliphatic chain metabolism: Adipic acid is activated into its CoA derivative by long-chain fatty acid-CoA ligase and subsequently undergoes β-oxidation catalyzed by acyl-CoA dehydrogenase to form acetyl-CoA. Short-chain aldehyde/alcohol byproducts generated during aliphatic chain metabolism are further degraded by aldehyde dehydrogenase and alcohol dehydrogenase. (3) Aromatic ring degradation and ring-cleavage: Terephthalic acid undergoes hydroxylation to form catechol, which is then cleaved by dioxygenases, producing intermediates that enter the tricarboxylic acid cycle.【Conclusion】This study successfully isolated Parageobacillus toebii B3 as a high-performance PBAT degrader through multi-parametric characterization (mass loss, surface topography, and hydrophilicity changes). The findings provide both theoretical foundations and practical microbial resources for controlling biodegradable microplastic pollution.