Culture continuous heat sterilization

The basic raw materials required include starting culture E. coli cells), nutrients (glucose and salts), tryptophan, water, ammonia and air. The process equipment includes fermentor, mixing tank, continuous heat sterilizer, centrifugal compressor, air filter and storage tank. 

The fermentation is usually continuous it proceeds under sterile conditions, at constant temperature, and is started with a defined starter culture to avoid side products as far as possible. Several processes were developed Shell had originally introduced a process that used methane (natural gas) as the feedstock for SCP production. The microorganisms are cultured in an aqueous medium at temperatures of 42 to 45°C and at a pH value of 6.8 under semisterile conditions. The final fermentation broth contains protein at a concentration of 25 g/L. The biomass is concentrated in large sedimentation tanks and then spray-dried. The mass balance equation (Eq. 9.3) shows that large volumes of oxygen are needed and that carbon dioxide and heat must be removed from the reactor. 

The sterilized and clarified must is now ready for its fermentation. An active culture of yeast is added in about a proportion of 2-10% by volume of the must. The temperature must be raised if necessary to 8o° F. so that the yeast multiplies rapidly and continues its activity until enough alcohol is formed to protect the wine against disease. In small wineries heating is done by suspending a milk can or bucket of hot water in the must. The... 

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