B. Braun Biotech

Braun Potter-S tissue homogenizer (B. Braun Biotech Co., Melsungen, Germany)... 

The pH was maintained at 5.0 by the addition of 2 M NaOH (Micro DCU-300 B. Braun Biotech). The fermentation temperature was 30°C and the stirrer speed was 500 rpm (MCU-200 B. Braun Biotech). Cell mass was produced in an initial batch phase using a glucose concentration of 64 g/L. The concentrations of mineral salts, trace metals, vitamins, and Ergosterol/ Tween-80 were the same as in the fed-batch experiments. When the glucose in the batch medium was completely consumed, 1.9 L of dilute-acid hydrolysate was pumped into the reactor at maximum pump speed, by using a peristaltic pump (Ul-M Alitea AB). The ratio between batch volume and the final volume (i.e., after all the hydrolysate had been added) was similar to the ratio in the PDU fed-batch experiments, approx 1 4. The reactor medium was sparged with nitrogen (600 mL/min). The C02 content in the exhaust gas was measured with a gas analyzer (TanDem Adaptive Biosystems, Luton, UK). 

B. Braun Biotech International GmbH POBox 1120 D-34209 Melsungen Germany... 

The enzymatic reactor consisted of a 500 mL-continuous tank reactor BIOSTAT Q (Braun-Biotech International) coupled to the ultrafiltration membrane. The additional volume of the ultrafiltration unit and piping was around 150 mL. Three solutions were added to the reactor by means of three variable speed peristaltic pumps, containing (a) Orange II, Mn2+ and oxalic acid (b) H2O2 and (c) MnP. Another peristaltic pump was used in order to feed the effluent into the ultrafiltration unit (Fig. 10.3). The recycling feed flow ratio was maintained at 12 1, as this flow rate allowed an adequate homogeneity of the enzymatic mixture but prevented the polarization or fouling of the membrane. 

B. Braun Melsungen Aktiengesellschaft Amersham Pharmacia Biotech FMC Corp. 

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