Marija Lješević, Kristina Kasalica, Ana Medić, Branka Lončarević, Abdullah Khraibah, Yingxi Li, Maxim V. Berezovski, Zoran Minić, Latinka Slavković Beškoski, Lidija Izrael Živković, Gordana GOJGIĆ CVIJOVIĆ, Ivanka Karadžić, Hideyuki Inui, John Giesy, Vladimir Beškoski
Perfluorooctanoic acid (PFOA), increasingly detected at extreme concentrations in industrial hotspots, caused a reduction in growth and a prolonged lag phase in Pseudomonas chlororaphis subsp. aurantiaca . In order to reveal microbial adaptation mechanisms and survival strategies under exposure to PFOA, a comparative proteomic analysis was undertaken. The up-regulation of phosphoglycerol transferase, lipoproteins, and long-chain fatty acid synthesis, together with the down regulation of cis unsaturation of fatty acids and changes in specific membrane-embedded porins, indicate alterations in membrane structure, fluidity, and permeability. The up-regulation of the divalent cation–regulated outer membrane protein H1, accompanied by the down-regulation of zinc and other metal transporters, reflect changes in metal ion homeostasis. In particular, altered iron homeostasis and expression of iron-, Fe-S clusters-, and heme-containing proteins were detected, along with the reduced activity of some iron-containing enzymes, as a result of inhibition by PFOA. Up-regulated enzymes of the methylcitrate and the glyoxylate cycles indicate alterations in central metabolic pathways associated with lipid metabolism in PFOA-treated cells. Changes in the respiratory chain may influence enhanced superoxide radical formation, triggering increased ROS production and the up-regulation of antioxidant enzymes, except those involved in thiol-based redox processes. In addition, PFOA alters the regulation of virulence-associated proteins. • First proteomic study of P. chlororaphis from PFAS-contaminated site. • High PFOA exposure (500 ppm) altered outer membrane and metabolic processes. • PFOA suppressed defense and enhanced invasion-related protein pathways. • Iron homeostasis and metal transport systems were significantly disrupted. • Findings reveal microbial adaptation mechanisms to PFAS exposure.