Polyurethane biodegradation by Fusarium parceramosum with insights into kinetic modelling and metabolic pathway

Polyurethane (PU) is an industrially versatile polymer whose environmental persistence pose significant waste management challenges. Although several PU-degrading microorganisms have been reported, studies evaluating degradation across chemically distinct PU substrate remain limited. The present study explores PU biodegradation potential of a soil-borne fungus Fusarium parceramosum, with two chemically different PU substrates-Impranil (PU dispersion), and PU foam-under unoptimized conditions. The fungus achieved 92% degradation of Impranil within 192 h, and 31.29% weight loss of PU foam over 60 d. Degradation kinetics were evaluated using zero-order, first-order, Langmuir, and Freundlich models, with zero-and first-order models showing best fit with experimental data. Enzymatic assay revealed significant urease and aliphatic carbamate-hydrolyzing activities associated with degradation. For Impranil, urease and aliphatic carbamate-hydrolyzing activities were 202.03 U/mL and 412.47 U/mL, respectively, whereas for PU foam they were 338.12 U/mL and 284.17 U/mL, respectively. Structural and chemical alterations were confirmed through SEM, FTIR, XRD and GC-MS analysis. Metabolite identification indicated the formation of degradation intermediates, suggesting their possible involvement in subsequent microbial processes. Overall, this study provides the first evidence of dual-substrate specificity of Fusarium parceramosum highlighting its potential in sustainable waste management approaches.