Contact

  • Academic
    jlee2024@stanford.edu
    University - Student Department: Political Science Position: Undergraduate
    University - Student Department: Ethics In Society Position: Undergraduate
    University - Student Department: Music Position: Undergraduate
    University - Student Department: Iberian and Latin American Cultures Position: Undergraduate
    University - Student Department: Change Leadership for Sustainability Position: Graduate

Additional Info

  • Mail Code: 2070

All Publications

  • Influence of the amyloid dye Congo red on curli, cellulose, and the extracellular matrix in E. coli during growth and matrix purification Influence of the amyloid dye Congo red on curli, cellulose, and the extracellular matrix in E. coli during growth and matrix purification Reichhardt, C., McCrate, O. A., Zhou, X., Lee, J., Thongsonboom, W., Cegelski, L. 2016; 408 (27): 7709-7717

    Abstract

    Microbial biofilms are communities of cells characterized by a hallmark extracellular matrix (ECM) that confers functional attributes to the community, including enhanced cohesion, adherence to surfaces, and resistance to external stresses. Understanding the composition and properties of the biofilm ECM is crucial to understanding how it functions and protects cells. New methods to isolate and characterize ECM are emerging for different biofilm systems. Solid-state nuclear magnetic resonance was used to quantitatively track the isolation of the insoluble ECM from the uropathogenic Escherichia coli strain UTI89 and understand the role of Congo red in purification protocols. UTI89 assembles amyloid-integrated biofilms when grown on YESCA nutrient agar. The ECM contains curli amyloid fibers and a modified form of cellulose. Biofilms formed by UTI89 and other E. coli and Salmonella strains are often grown in the presence of Congo red to visually emphasize wrinkled agar morphologies and to score the production of ECM. Congo red is a hallmark amyloid-binding dye and binds to curli, yet also binds to cellulose. We found that growth in Congo red enabled more facile extraction of the ECM from UTI89 biofilms and facilitates isolation of cellulose from the curli mutant, UTI89ΔcsgA. Yet, Congo red has no influence on the isolation of curli from curli-producing cells that do not produce cellulose. Sodium dodecyl sulfate can remove Congo red from curli, but not from cellulose. Thus, Congo red binds strongly to cellulose and possibly weakens cellulose interactions with the cell surface, enabling more complete removal of the ECM. The use of Congo red as an extracellular matrix purification aid may be applied broadly to other organisms that assemble extracellular amyloid or cellulosic materials. Graphical abstract Solid-state NMR was used to quantitatively track the isolation of the insoluble amyloid-associated ECM from uropathogenic E. coli and understand the role of Congo red in purification protocols.

    View details for DOI 10.1007/s00216-016-9868-2