title: Analysis of the Aspergillus fumigatus Biofilm Extracellular Matrix by Solid-State Nuclear Magnetic Resonance Spectroscopy.
abstract: Aspergillus fumigatus is commonly responsible for lethal fungal infections among immunosuppressed individuals. A. fumigatus forms biofilm communities that are of increasing biomedical interest due to the association of biofilms with chronic infections and their increased resistance to antifungal agents and host immune factors. Understanding the composition of microbial biofilms and the extracellular matrix is important to understanding function and, ultimately, to developing strategies to inhibit biofilm formation. We implemented a solid-state nuclear magnetic resonance (NMR) approach to define compositional parameters of the A. fumigatus extracellular matrix (ECM) when biofilms are formed in RPMI 1640 nutrient medium. Whole biofilm and isolated matrix networks were also characterized by electron microscopy, and matrix proteins were identified through protein gel analysis. The (13)C NMR results defined and quantified the carbon contributions in the insoluble ECM, including carbonyls, aromatic carbons, polysaccharide carbons (anomeric and nonanomerics), aliphatics, etc. Additional (15)N and (31)P NMR spectra permitted more specific annotation of the carbon pools according to C-N and C-P couplings. Together these data show that the A. fumigatus ECM produced under these growth conditions contains approximately 40% protein, 43% polysaccharide, 3% aromatic-containing components, and up to 14% lipid. These fundamental chemical parameters are needed to consider the relationships between composition and function in the A. fumigatus ECM and will enable future comparisons with other organisms and with A. fumigatus grown under alternate conditions.
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California, USA.
authors.forename: Courtney
authors.initials: C
authors.lastname: Reichhardt
authors.affiliation: Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, California, USA California Institute for Medical Research, San Jose, California, USA.
authors.forename: Jose A G
authors.initials: JA
authors.lastname: Ferreira
authors.affiliation: Cell Sciences Imaging Facility, Stanford University School of Medicine, Stanford, California, USA.
authors.forename: Lydia-Marie
authors.initials: LM
authors.lastname: Joubert
authors.affiliation: Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, California, USA California Institute for Medical Research, San Jose, California, USA.
authors.forename: Karl V
authors.initials: KV
authors.lastname: Clemons
authors.affiliation: Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, California, USA California Institute for Medical Research, San Jose, California, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Stevens
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California, USA cegelski@stanford.edu.
authors.forename: Lynette
authors.initials: L
authors.lastname: Cegelski
mesh_terms: D001232:Aspergillus fumigatus / Q000378:metabolism / Q000502:physiology*; D018441:Biofilms; D005109:Extracellular Matrix / Q000737:chemistry* / Q000648:ultrastructure; D016326:Extracellular Matrix Proteins / Q000032:analysis; D005656:Fungal Proteins / Q000032:analysis
chemical_list: D016326:Extracellular Matrix Proteins; D005656:Fungal Proteins