SCP from carbon dioxide

Figure 7.19 Ultraviolet trace (270 nm) obtained from SFC of a mixture of (A) sulphadoxine (1-SDX), (B) sulphamethazine (2-SMT), (C) sulpha-merazine (3-SMZ), (D) sulphadimethoxine (4-SDM), (E) sulphadiazine (5-SDZ), (F) sulphaquinoxaline (6-SQX), (G) sulphachlorpyridazine (7-SCP), and (H) sulphathiazole (8-STZ) on a 100 x 4.6-mm ID column packed with 5- tm amino-bonded Spherisorb. The mobile phase was initially carbon dioxide modified with 15% methanol at a flow rate of 4 ml/ min. After 4 min, the concentration of methanol was increased to 25%. Column pressure, 361 bars temperature, 90°C. [Reprinted from Ref. 33, J. Chromatogr. 540, 239 (1991) with kind permission of Elsevier Science Publishers, The Netherlands.]...

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. 

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