Comparative proteomic profile of Aspergillus niger in response to polytetrafluoroethylene and irradiated polytetrafluoroethylene for enhanced bioremoval

Polytetrafluoroethylene (PTFE) is a widely used fluoropolymer known for its chemical stability and resistance to degradation, making it a persistent environmental pollutant. The bioremediation of PTFE has proven challenging due to its inert nature. The aim of the present study is to characterize how changes in PTFE and irradiated PTFE may affect the proteomic profile of Aspergillus niger to propose protein biomarkers and depict bioremoval strategies. The results show that irradiating PTFE causes structural and spectral changes that increase with the increase of electron beam irradiation doses at 20, 40, 80, 160, and 320 kGy as compared to the control. PTFE and irradiated PTFE were added to a 24 h Aspergillus niger culture, and the proteomic profile was studied using quantitative protein assay and a high-throughput Ultra Performance Liquid Chromatography (UPLC) proteomics approach. The resultant chromatograms show that peak shifts can serve as a rapid indicator of PTFE and irradiated PTFE, highlighting the potential of proteomic profiling as a rapid screening tool. Energy Dispersive X-Ray (EDX) mapping images show fluoride attached to A. niger mycelia, while quanitative SPADNS Fluoride assay revealed deflourination % of 28.0 and 31.6% for 80 and 320 kGy irradiated PTFE culture, respectively, as compared 11.2% for non-irradiated PTFE. These findings suggest that 1) high electron beam irradiation doses enhance PTFE degradation, 2) the proteomic profile can be used as a biomarker to detect the presence of PTFE or irradiated PTFE, and 3) A. niger can be further exploited for both PTFE and irradiated PTFE bioremoval via deflourination or adsorption on mycelial network. Further research is needed to enhance the deflourination process.