Tapping into the nativePseudomonasBacterial Biofilm Structure by High-Resolution 1D and 2D MAS solid-state NMR

Abstract

AbstractWe present a high-resolution 1D and 2D magic-angle spinning (MAS) solid-state NMR (ssNMR) study to characterize nativePseudomonas fluorescenscolony biofilms at natural abundance without isotope-labelling. By using a high-resolution INEPT-based 2D1H-13C ssNMR spectrum and thorough peak deconvolution approach at the 1D ssNMR spectra, approximately 80/134 (in 1D/2D) distinct biofilm chemical sites were identified. We compared CP and INEPT13C ssNMR spectra to different signals originating from the mobile and rigid fractions of the biofilm, and qualitative determined dynamical changes by comparing CP buildup behaviors. Protein and polysaccharide signals were differentiated and identified by utilizing FapC signals as a template, a biofilm forming functional amyloid fromPseudomonas. We also attempted to identify biofilm polysaccharide species by using1H/13C chemical shifts obtained from the 2D spectrum. This study marks the first demonstration of high-resolution 2D ssNMR spectroscopy for characterizing native bacterial biofilms and expands the scope of ssNMR in studying biofilms. Our experimental pipeline can be readily applied to other in vitro biofilm model systems and natural biofilms and holds the promise of making a substantial impact on biofilm research, fostering new ideas and breakthroughs to aid in the development of strategic approaches to combat infections caused by biofilm-forming bacteria.