Pilot scale fermentation was carried out in a 72 L BIOSTAT UD
bioreactor (B-Braun Biotech, Germany) containing 45 L of coffee
pulp hydrolysate and 10 g L1 yeast extract. Fermentation was carried
out at 52 C and pH 6. Due to limitations in coffee pulp, fermentation
was carried out only once. Stirring occurred at
400 rpm using a double Rushton turbine. Regulation of pH was carried
out by adding 20% (w/w) NaOH. A 5% (v/v) inoculum was used.
The inoculum was grown for 17 h in a 5 L fermentation vessel containing
2 L of medium consisting of 66 g L1 dextrose monohydrate
and 15 g L1 yeast extract inoculated with 120 mL MRS culture (see
Section 2.2). Samples were taken regularly and treated as described
in Section 2.4.1. After fermentation, culture broth was inactivated
at 85 C for 30 min and stored at 20 C until used in downstream
processing.
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