Sampling, separation, and quantification of <i>N</i> ‐acyl homoserine lactones from marine intertidal sediments

N-acyl homoserine lactones (AHLs) are molecules produced by many Gram-negative bacteria as mediators of cell-cell signaling in a mechanism known quorum sensing (QS). QS is widespread marine regulating diverse processes, such virulence or excretion polymers that mediate biofilm formation. Associated eukaryotes, microalgae, respond to these cues well, leading an intricate network. To date, only very few studies attempted measure AHL concentrations phototrophic microbial communities, which hot spots for bacteria-bacteria well microalgae-bacteria interactions. quantification environmental samples challenging and requires robust reproducible sampling strategy. However, knowing about opens up multiple perspectives from answering fundamental ecological questions deriving guidelines manipulation control biofilms. Here, we present method identification intertidal sediments. The use contact cores sediment ensures sample surface area volume at each location. Flash-freezing the with liquid nitrogen prevents enzymatic degradation between extraction. After solvent extraction, were analyzed ultra-high performance chromatography-high resolution mass spectrometry (UHPLC-HRMS) allows baseline-separate 16 different AHLs less than 10 min. sensitivity sufficient detection cm3.