Microbial Metabolomics’\nLatest SICRIT: Soft\nIonization by Chemical Reaction In-Transfer Mass Spectrometry

Microbial\nmetabolomics studies are a common approach\nfor identifying\nmicrobial strains that have a capacity to produce new chemistries\nboth <i>in vitro</i> and <i>in situ</i>. A limitation\nto applying microbial metabolomics to the discovery of new chemical\nentities is the rediscovery of known compounds, or “known unknowns.”\n One factor contributing to this rediscovery is that the majority\nof laboratories use one ionization sourceelectrospray ionization\n(ESI)to conduct metabolomics studies. Although ESI is an efficient,\nwidely adopted ionization method, its widespread use may contribute\nto the reidentification of known metabolites. Here, we present the\nuse of a dielectric barrier discharge ionization (DBDI) for microbial\nmetabolomics applications through the use of soft ionization chemical\nreaction in-transfer (SICRIT). Additionally, we compared SICRIT to\nESI using two different <i>Vibrio</i> species: <i>Vibrio\nfischeri</i>, a symbiotic marine bacterium, and <i>Vibrio\ncholerae</i>, a pathogenic bacterium. Overall, we found that\nthe SICRIT source ionizes a different set of metabolites than ESI,\nand it has the ability to ionize lipids more efficiently than ESI\nin the positive mode. This work highlights the value of using more\nthan one ionization source for the detection of metabolites.