Marine particles as underexplored hotspots for antimicrobial peptide discovery: an ecology-guided frontier in marine natural product bioprospecting

The increasing global antibiotic resistance has created a pressing need for new antimicrobial drugs. Antimicrobial peptides (AMPs) come into the spotlight for their antibacterial properties, particularly against multidrug-resistant pathogens. Because AMPs typically mediate localized interference competition, we hypothesize that spatially confined, highly competitive microbiomes create ecological conditions that favor the evolution, expression, and diversification of AMPs, although spatial structure may equally promote niche partitioning, cooperative interactions, and producer–resistant coexistence. We therefore propose, as a working hypothesis, that marine particles represent promising yet underexplored reservoirs of untapped marine AMPs. Marine particles are ubiquitous throughout the ocean, ranging from the sunlit surface waters to the deepest hadal environments. They are densely colonized microhabitats where nutrient gradients, spatial proximity, chemical signaling, and interspecies competition among microorganisms converge—unique characteristics that position marine particles as natural laboratories for the evolution of novel AMPs. However, most marine microorganisms are challenging to cultivate. Fortunately, metagenomics is greatly expanding the scope of marine AMP discovery by enabling researchers to screen for elusive peptide-encoding genes and complex biosynthetic gene clusters in uncultivated microbial communities. Additionally, advancements in artificial intelligence are further transforming marine AMP bioprospecting by moving from passive exploration to active molecular understanding and navigation. This review synthesizes our current understanding of the microbial ecology and emerging technologies that drive marine AMP discovery, and explores the application potentials of marine AMPs in human medicine, agriculture, and mariculture.