Actual coverage will always differ somewhat from what is printed here. Often want to look at balanced equation relative to 6C synthesis. Many different genera of bacteria include members that can induce hydrogenase. When hydrogen disappears, back to heterotrophic life. Hydrogen bacteria are usually facultative chemolithotrophs.
Rivers can run rust red.
Mines have been major sources of pollution. H 2 SO 4 per year. To cure problem, must seal up old mines, prevent oxygen access. Also strip mines must be promptly covered up once mining is done to block access of microbes and oxygen to sulfur. If tailings contain S, microbes will produce H 2 SO 4 .