RECIRCULATION TOWER BIOREACTOR FOR SOLID-STATE FERMENTATION

A method and apparatus for producing single cell proteins or other products from a substrate made up of solid lignocellulosic materials, such as wood chips, wherein a plurality of perforated trays each containing a layer of substrate are loaded one above another in a recirculating tower reactor. After innoculating the layers of substrate with a white rot fungi, such as Polyporus anceps, a nutrient solution is recirculated downwardly through the reactor, at a rate sufficient to keep the microorganism active and the layers of substrate moist, and air is injected upwardly through the reactor at a rate sufficient to maintain aerobic fermentation and about 2-3% carbon dioxide in the exhaust gases.