TITLE: Xanthanproduktion im Blasensaeulen-Bioreaktor. (Xanthane production in the bubble column bioreactor)

AUTHOR: II-Soon Suh.

INST.  AUTHOR: Technische Univ. Braunschweig (Germany, F.R.). Fakultaet fuer Maschinenbau und Elektrotechnik.

LANGUAGE: German

PUB.  TYPE: Technical Report

PUB.  COUNTRY: Germany Federal Republic

SOURCE: Other [$TFFIZ],  14 May 92,  147p.

NTIS ORDER NO.: TIB/B93-00317INW

ABSTRACT:

The industrial production of xanthane occurs in batch operation in stirred boiler reactors. The enrichment of the product in the culture medium causes an extreme increase of viscosity during strongly pseudoplastic flow behavior. Because of inhomogeneous distribution of the shear gradient in the stirred boiler, local deviations from the optimal fermentation conditions can occur (temperature, pH, oxygen supply); even stagnant regions may form at the walls. The suitability of tower reactors for xanthane production was investigated in the dissertation. The bubble column is by far superior to other reactor types (airlift, three-phase fluidized bed, stirred boiler, immersion-type beam reactor) with regard to good mixing of highly viscous culture broths of Xanthomonas campestris.  The rise of the large bubbles which fill almost the entire column cross-section practically leads to intensive mixing. This not only makes the bubble column suitable for production but allow also the establishment of dependable fundamentals for model formation. (orig./EF). (Copyright (c) 1993 by FIZ. Citation no. 93:000317.)