The following submission statement was provided by /u/mutherhrg:

Fermentation is a process that uses microbes, to break down compounds to create products like protein or alcohol. This allows for basic raw ingredients such as glucose, starch, carbon monoxide or methane to be used to produce complex food like protein.

Traditional fish food for farmed fish is largely comprised of wild fish or soy. This leads to overfishing and massive amounts of land use for the growing of soy. By using industrial scale fermentation, you can vastly reduce the land and water needed to produce fish food. This technology could also be used to feed other kind of livestock as well.

Please reply to OP's comment here: https://old.reddit.com/r/Futurology/comments/ybs76j/worlds_largest_protein_factory_uses_fermentation/iti67g4/