Proteomic profiling of Ruegeria in response to coral tissue extract

Probiotic applications show great potential for coral restoration, though conventional probiotics may form only transient associations with hosts. A proof-of-concept study revealed that Ruegeria MC10, an evolutionarily endosymbiont lineage, could persistently colonize coral tissue and enhance host health throughout an 8-month field experiment. To elucidate the molecular mechanisms underlying successful symbiosis, we conducted a comparative proteomic analysis of three Ruegeria strains – the MC10 representative MC10-B4 and two coral-derived counterpart, MC0-A5 and MC15-BG7 - in response to metabolites from the coral Acropora pruinosa. Following 4-hour exposures to coral tissue extracts or autoclaved 0.22 μm-filtered seawater (AFSW) controls at 28°C during exponential phase, we performed comprehensive protein characterization by LC-MS/MS. Differential protein expression profiles revealed strain-specific adaptations.