A Label-Free Approach for Relative Spatial Quantitation of c-di-GMP in Microbial Biofilms

Anal Chem. 2024 May 28;96(21):8308-8316. doi: 10.1021/acs.analchem.3c04687. Epub 2024 May 16.

Abstract

Microbial biofilms represent an important lifestyle for bacteria and are dynamic three-dimensional structures. Cyclic dimeric guanosine monophosphate (c-di-GMP) is a ubiquitous signaling molecule that is known to be tightly regulated with biofilm processes. While measurements of global levels of c-di-GMP have proven valuable toward understanding the genetic control of c-di-GMP production, there is a need for tools to observe the local changes of c-di-GMP production in biofilm processes. We have developed a label-free method for the direct detection of c-di-GMP in microbial colony biofilms using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI). We applied this method to the enteric pathogen Vibrio cholerae, the marine symbiont V. fischeri, and the opportunistic pathogen Pseudomonas aeruginosa PA14 and detected spatial and temporal changes in c-di-GMP signal that accompanied genetic alterations in factors that synthesize and degrade the compound. We further demonstrated how this method can be simultaneously applied to detect additional metabolites of interest from a single sample.

MeSH terms

  • Aliivibrio fischeri / metabolism
  • Biofilms*
  • Cyclic GMP* / analogs & derivatives
  • Cyclic GMP* / analysis
  • Cyclic GMP* / metabolism
  • Pseudomonas aeruginosa* / metabolism
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization* / methods
  • Vibrio cholerae* / metabolism

Substances

  • Cyclic GMP
  • bis(3',5')-cyclic diguanylic acid