Marine Particles as Reservoirs of Novel Antimicrobial Peptides: An Emerging Frontier in Marine Drug Discovery

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. Since AMPs act locally, they achieve optimal antimicrobial effectiveness and face maximum evolutionary pressure within spatially confined, highly competitive microbiomes. This ecological principle justifies marine particles as promising 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 revolutionizing 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.