> Just curious, are there lifeforms today that rely on these metals to live in anaerobic environments? Maybe the hydrothermal vents that are talked about?

Yes! There are a few interesting variants called, "dissimilatory metal-reducing microorganisms"[1] and "sulfate-reducing microorganisms." They're a class that's being studied as a model for non-Terran life.

There are actually quite a few environments on Earth that are time capsules / have little ship bottles of very different life inside of them. For example, the Movile cave, https://en.wikipedia.org/wiki/Movile_Cave

    Life in the cave has been separated from the outside for the past 5.5 million years and it is based completely on chemosynthesis. Due to its extreme environment, access to Movile Cave is strictly controlled, and a limited number of researchers have permission to study its conditions.

It's my dream to find one of these sites. I think there are quite a few locations out there yet to be discovered.

[1] https://en.wikipedia.org/wiki/Dissimilatory_metal-reducing_m...

[2] https://en.wikipedia.org/wiki/Sulfate-reducing_microorganism