Growth Conditions Shape the Fatty Acid Composition of Pedobacter lusitanus NL19

Pedobacter lusitanus NL19 is a Gram-negative bacterium recognized for its potential to produce various antimicrobial metabolites, including lipids. However, how growth conditions regulate this production capability remains poorly understood. Like other bacteria, P. lusitanus NL19 adapts its membrane fatty acid (FA) composition in response to environmental conditions, a process that appears closely linked to its antimicrobial activity. In this study, we used GC-MS to identify and quantify FA, using alkaline transmethylation to produce FAME from esterified FA, and to track how different culture media (M9, R2A-B, PC25, and TSB) drive membrane FA remodeling in P. lusitanus NL19. The results revealed that cultivation in media associated previously with antimicrobial activity triggered an increase in monounsaturated and hydroxylated FA, in contrast to the saturated profiles observed under nutrient-rich conditions. This metabolic flexibility highlights an interplay between nutrient availability and membrane composition. Further research should evaluate whether FA provision triggers the release or excretion of bioactive secondary metabolites. Ultimately, this research advances our understanding of how environmental factors regulate lipid biosynthesis in P. lusitanus NL19.