Back in 1976...ICI's Pruteen
What is claimed to be the world's largest fermenter will form the heart of a novel operation due to go up at Imperial Chemical Industries' Billingham complex on England's east coast. Inside will grow bacteria that after harvesting and drying will be the basis of a high-protein animal feed supplement, tradenamed Pruteen. Annual output capability will be 50,000 to 75,000 metric tons. When the $70 million facility begins operation late in 1979, it will mark a new phase in the activities of ICT's agricultural division.
Apart from the unusual fermenter, the technology will include a number of unique features. The bacteria, a strain of Methylophilus methylotrophus, will grow on a mixture of air, ammonia, methanol, and nutrient salts. Fermentation will be continuous. A novel flocculation and flotation technique will be used to recover the bacteria. And the entire operation will run under sterile conditions.
Came online in the early 80s and I think died a death due to Methanol being an expensive fuel for fermentation. However, the learnings went-on to deliver Quorn with Rank Hovis McDougall.
As a Food student at the time it was a brave new world!
The rest is history....
https://en.wikipedia.org/wiki/Quorn