Wee Young-Jung, Yun Jong-Sun, Kang Kui-Hyun, Ryu Hwa-Won
Faculty of Chemical Engineering and Institute of Bioindustrial Technology, Chonnam National University, Gwangju, Korea.
Appl Biochem Biotechnol. 2002 Spring;98-100:1093-104. doi: 10.1385/abab:98-100:1-9:1093.
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).
粪肠球菌RKY1是一种能还原富马酸盐的细菌，被固定在非对称中空纤维生物反应器（HFBR）中用于连续生产琥珀酸。将细胞接种到以横向模式运行的HFBR壳侧。由于在连续运行过程中HFBR内的pH值下降至约5.7，因此有必要在运行24小时后将进料pH从7.0改为8.0，以提高琥珀酸的产量。在含有富马酸盐和甘油的培养基连续运行期间，对于0.1至0.4 h⁻¹的稀释率，当富马酸盐初始浓度为30 g/L时，琥珀酸盐的生产率为3.0 - 10.9 g/(L·h)；当富马酸盐为50 g/L时，生产率为4.9 - 14.9 g/(L·h)；当富马酸盐为80 g/L时，生产率为7.2 - 17.1 g/(L·h)。HFBR获得的琥珀酸盐最大生产率（17.1 g琥珀酸盐/[L·h]）比使用80 g/L富马酸盐的分批生物转化（9.9 g琥珀酸盐/[L·h]）高1.7倍。此外，HFBR的长期稳定性通过连续高效生产琥珀酸超过15天（360小时）得到了证明。
