Have you ever wondered what concentration of molybdenum (Mo) limits nitrogen fixation? Zak Stevenson (Microbiology PhD ’24) studied Deming Lake, where Mo was barely detectable, and surprisingly, nitrogen fixation was not Mo-limited. This was determined by adding Mo and observing no change in nitrogen fixation rates. One possible explanation is that the very low sulfate in this lake allows for highly efficient Mo uptake without the use of alternative nitrogenases that do not require Mo (i.e., V-Fe, Fe-Fe). Alternative nitrogenases were not detected through metagenomics or metatranscriptomics.
Lead author Zackry Stevenson (Ph.D.) spent extensive time at Itasca Biological Station and Laboratories to carry out this study. This study was also made possible by major contributions from Dylan Schultz (Microbiology PhD ’25) and Michelle Chamberlain (current Microbiology PhD candidate)!
Learn more about this cool study from the link below: