Protection of nitrogenase from photosynthetic O evolution in : methodological pitfalls and advances over 30 years of research.

The genus comprises some of the most abundant N-fixing organisms in oligotrophic marine ecosystems. Since nitrogenase, the key enzyme for N fixation, is irreversibly inhibited upon O exposure, these organisms have to coordinate their N-fixing ability with simultaneous photosynthetic O production. Although being the principal object of many laboratory and field studies, the overall process of how reconciles these two mutually exclusive processes remains unresolved. This is in part due to contradictory results that fuel the enigma. In this review, we sift through methodological details that could potentially explain the discrepancy between findings related to 's physiology. In doing so, we exhaustively contrast studies concerning both spatial and temporal nitrogenase protective strategies, with particular attention to more recent insights. Finally, we suggest new experimental approaches for solving the complex orchestration of N fixation and photosynthesis in .