Continuous production of succinic acid by a fumarate-reducing bacterium immobilized in a hollow-fiber bioreactor.
Enterococcus faecalis RKY1, a fumarate-reducing bacterium, was immobilized in an asymmetric hollow-fiber bioreactor (HFBR) for the continuous production of succinic acid. The cells were inoculated into the shell side of the HFBR, which was operated in transverse mode. Since the pH values in the HFBR declined during continuous operation to about 5.7, it was necessary to change the feed pH from 7.0 to 8.0 after 24 h of operation in order to enhance production of succinic acid. During continuous operation with a medium containing fumarate and glycerol, the productivity of succinate was 3.0-10.9 g/(L x h) with an initial concentration of 30 g/L of fumarate, 4.9-14.9 g/(L x h) with 50 g/L of fumarate, and 7.2-17.1 g/(L x h) with 80 g/L of fumarate for dilution rates between 0.1 and 0.4 h(-1). The maximum productivity of succinate obtained by the HFBR (17.1 g of succinate/[L x h]) was 1.7 times higher than that of the batch bioconversions (9.9 g of succinate/ [L x h]) with 80 g/L of fumarate. Furthermore, the long-term stability of the HFBR was demonstrated with a continuously efficient production of succinate for more than 15 d (360 h).
Wee
Young-Jung
YJ
Faculty of Chemical Engineering and Institute of Bioindustrial Technology, Chonnam National University, Gwangju, Korea.
Yun
Jong-Sun
JS
Kang
Kui-Hyun
KH
Ryu
Hwa-Won
HW
D001431:Bacteriological Techniques / Q000295:instrumentation / Q000379:methods; D019149:Bioreactors; D002455:Cell Division; D018914:Cells, Immobilized / Q000378:metabolism*; D013293:Enterococcus faecalis / Q000254:growth & development / Q000378:metabolism*; D004867:Equipment Design; D005650:Fumarates / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010084:Oxidation-Reduction; D019802:Succinic Acid / Q000378:metabolism*
D005650:Fumarates; D019802:Succinic Acid