Periodic Reporting for period 1 - PAERADOX (Precursors to Modern Aerobic Ammonium Oxidation: Oxygenic and Electrogenic Anaerobic Pathways)
Reporting period: 2018-08-01 to 2020-07-31
How did microbes evolve to use O2? How did O2-dependent enzymes and pathways derive from or evolve under anoxic conditions? This central evolutionary mystery remains essentially unresolved, with conflicting opinions and fragments of evidence. PARAEDOX seeks ancient microbial genes to seek answers to those questions. By identifying novel but ancient metabolisms in reconstructing their evolutionary history, it hunts the knowledge of the evolution of aerobiosis on Earth.
I use ammonium oxidizers as a model species in PARAEDOX, a Marie Curie IF project. Findings will provide a major contribution to understanding the transition towards aerobiosis. The overall objectives of PARAEDOX are to discover novel ancient pathways in ammonium oxidizers, to characterize these remnant pathways and to identify their evolutionary history with an ambition to reveal their ancestral relation with aerobic pathways.
Although my analyses are still under progress, the preliminary results revealed that the proposed pathways are ancient and still exist in the modern era. I discovered that a proposed microbial is dominant in oxygen minimum zones. Multiple evidence suggests the activity and expression of the anticipated pathways in ammonia oxidizers.