Part of the article is about a 2015 discovery showing that at least some organisms appearing to directly ingest electrons are actually emitting enzymes that gra

Part of the article is about a 2015 discovery showing that at least some organisms appearing to directly ingest electrons are actually emitting enzymes that grab an electron and a proton from the environment, then consuming the resulting hydrogen (search for Spormann). The article also mentions that there is evidence for direct electron transfer, but it is yet unpublished.