ANALYTICAL CONSIDERATIONS AND METHODS FOR COMPREHENSIVE ANALYSIS OF BACTERIAL PHOSPHOLIPIDOMICS USING HILIC-MS/MS

Omics technologies have rapidly evolved over the last half century through vast improvements in efficient extraction methodologies, advances in instrumentation for data collection, and a wide assortment of informatics tools to help deconvolute sample data sets. However, there are still untapped pools of molecules that warrant further analytical attention. As the frontline defense of the cell against exterior influences, the phospholipid membrane is key in structure, defense, and signaling, but current omics studies are only just now catching up to the potential hidden within cellular lipid profiles. Examination of shifts in phospholipid speciation and character could provide researchers with a wealth of information about how a cell attempts to adapt and survive when faced with adverse conditions. Application of such information could be valuable to the production of industrially relevant specialized bacterial strains, capable of processing large amounts of waste or feedstock as an affordable and renewable method. Using a flexible lipid extraction method using methyl tert-butyl ether (MTBE) combined with nanoscale hydrophilic interaction chromatography (HILIC) and nano-electrospray (nESI) tandem mass spectrometry (MS/MS), shifts in the lipidomes of several bacteria under consideration as industrial workhorses were investigated under variable growth conditions induced by introduction of toxic chemicals. Specific lipidome shifts were linked to specific growth conditions, which could lead to the production of bacterial strains designed to survive rough environments through genetic modification of phospholipid production.