Using ultra-high resolution mass spectrometry to find what lies beneath the surface

Herein, we will describe the use of ultra-high resolution mass spectrometry (MS) to address the key knowledge gaps in functional understanding of how complex microbiomes influence and are influenced by their environment and present selected applications to oceanic, freshwater and soil microbiome field studies. Fourier transform ion cyclotron resonance (FTICR) MS offers the highest resolution and accuracy of any mass analyzer. And, because all key measures of FTICR MS performance improve with increased magnetic field strength, a 21T FTICR spectrometer recently deployed at EMSL will arguably provide that next level of performance needed to decipher the chemistry and dynamics of the belowground carbon cycle. Characterization and quantitation of intact proteins, so-called top-down MS, will enable physiologically relevant studies of microbes and higher eukaryotes. 21T FTICR MS has a potential to push the current limits of top-down MS and facilitate high-throughput comprehensive characterization of the functional proteomes. Analyses of complex natural organic matter combined with omics workflows and MS imaging will provide identity and quantity of intact molecular structures (e.g. metabolites, proteins) derived from plants and soil microbiome needed to ascertain soil vulnerability and soil-plant-atmosphere ecosystem response to climate change.