Ss. Kesava et al., PRODUCTION OF ETHANOL BY IMMOBILIZED WHOLE CELLS OF ZYMOMONAS-MOBILISIN AN EXPANDED BED BIOREACTOR, Process biochemistry, 31(5), 1996, pp. 449-456
Whole cells of Zymomonas mobilis, immobilised on pectin beads, were st
ablised by curing in a mixture of 0.2 M CaCl2 .2H2O and Na2B4O7 . 10H(
2)O for 24 h at 4 degrees C. Ethanol fermentation was studied using di
fferent glucose concentrations (50-200 g/litre) by these immobilised b
eads. The kinetics of this process was studied in a glucose step-feedi
ng system with different total glucose concentrations (150 and 200 g/l
itre) in a specially designed shake flask. Immobilised whole cells wer
e also used for ethanol fermentation in an expanded bed bioreactor and
its performance characteristics were compared with those of a regular
batch mechanically stirred tank bioreactor Fermentation rates and eth
anol yields were higher in the expanded bed bioreactor system than in
the batch mechanically agitated stirred tank bioreactor The stabilised
pectin beads were damaged less in the expanded bioreactor than in the
regular batch stirred tank reactor.