- Environmental conditions and microbial lifestyles both influence which metal micronutrients particular microorganisms use.
- Variations in geochemical conditions over eons influenced what metals microorganisms use along with the metabolic apparatus needed to use those metals.
- Global cycles involving oxygen, carbon dioxide, nitrogen, and phosphorus depend on metalloenzymes that incorporate one or more metals and, in at least one case, a rare-earth element.
- Mass spectrometry is giving way to newer analytic methods that allow imaging of metals at parts-per-billion concentrations and that pinpoint metals in microbial cells, aggregates, and biofilms.
- Amid progress, efforts to characterize microbial metalloenzymes are still in their infancy.