Abstract

Sunlight drives virtually all life on the Earth’s surface, with about 50% of primary productivity occurring in marine systems. Yet, this traditional view of phototrophy changed radically with the discovery of marine bacterial rhodopsins (i.e., proteorhodopsins; PR), over twenty years ago. PRs are simple light-driven proton pumps present in over 80% of surface bacterioplankton, which allow them to transform light into biochemical energy.

Combining culture-based physiology studies with (meta)-genomics, (meta)-transcriptomics, and environmental quantifications we are just starting to understand the role that PR-based photoheterotrophy plays in the ocean. In this presentation, I will discuss the knowns and unknowns of PR-phototrophy and what we are starting to learn from looking at its natural distributions in different oceanographic basins, ranging from extreme ultraoligotrophic regions to high productivity environments