Light exposure patterns shape marine microbial biogeography and metabolic strategy

Marine microorganisms drive the Earth’s biogeochemical cycles, yet most cannot be cultured in laboratories, severely limiting in-depth studies of their ecological roles and application potential. In a decade-long study, we isolated 16,931 microbial strains from 1516 sampling sites across seven oceanic regions. By integrating omics and environmental data, we found that light conditions—such as long-term variations in sunlight at different latitudes and depths—are key factors shaping microbial biogeography and metabolic strategies. Moreover, 71.67% of the strains exhibited strict light-pattern specificity, a trait linked to differences in metabolic strategies adapted to their native environments. Based on this, we developed a database to predict optimal culture conditions for uncultured microorganisms, clarified the core reasons for their culturability challenges, and provided a practical pathway for exploring the potential of unknown microbes. Localized light histories control energy-acquisition tactics in marine micro-organisms, according to analyses of isolated microbial strains from sites around the world.