ISU Microbiology Graduate Program

Michelle Chamberlain and members of the Swanner lab recently presented at AbSciCon in Madison, Wisconsin. Michelle gave a talk about the interplay between phosphorus cycling and Cyanobacteria activity in a ferruginous lake. This work can provide insights into nutrient cycling and mineral formation on ancient Earth and Mars.

Caleb Skow and Logan C. Ott of Dr. Mellata’s lab recently published an article in Frontiers in Microbiology titled, “A defined microbiota mouse model for Salmonella Paratyphi A oral infection”. In this article, Dr. Mellata’s lab employs gnotobiotic mice harboring the altered Schaedler flora from multiple genetic backgrounds as a model for oral acquisition and pathogenesis of human-host-restricted pathogen Salmonella Paratyphi A.

Frontiers | A defined microbiota mouse model for Salmonella Paratyphi A oral infection IntroductionSalmonella Paratyphi A (SPtA) is an emerging pathogen that primarily infects humans and causes enteric fever, yet it has not received sufficient ...

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:

Lowering the Mo limit for nitrogen fixation by Mo-nitrogenase - Communications Earth & Environment Substantial nitrogen fixation at sub-nanomolar molybdenum concentrations without alternative nitrogenases, with important implications for early Earth primary productivity, according to results from a ferruginous, low-sulfate, low-Mo, cyanobacteria-dominated lake.