Ryu H W, Kang K H, Yun J S
Department of Biochemical Engineering, Chonnam National University, Kwangju, Korea.
Appl Biochem Biotechnol. 1999 Spring;77-79:511-20. doi: 10.1385/abab:78:1-3:511.
In this study, a facultative bacterium that converts fumarate to succinate at a high yield was isolated. The yield of bioconversion was enhanced about 1.2 times by addition of glucose into culture medium at an initial concentration of 6 g/L. When the initial cell density was high (2 g/L), the succinate produced at pH 7.0 for initial fumarate concentrations of 30, 50, 80, and 100 g/L were 29.3, 40.9, 63.6, and 82.5 g/L, respectively, showing an increase with the initial fumarate concentration. The high yield of 96.8%/mole of fumarate in just 4 h was obtained at the initial fumarate concentration of 30 g/L. Comparing these values to those obtained with low cell culture (0.2 g/L), we found that the amount of succinate produced was similar, but the production rate in the high cell culture was about three times higher than was the case in the low cell culture. This strain converted fumarate to succinate at a rate of 3.5 g/L.h under the sparge of CO2.
在本研究中，分离出了一种能将富马酸盐高产转化为琥珀酸盐的兼性细菌。通过向培养基中添加初始浓度为6 g/L的葡萄糖，生物转化率提高了约1.2倍。当初始细胞密度较高（2 g/L）时，对于初始富马酸盐浓度为30、50、80和100 g/L的情况，在pH 7.0条件下产生的琥珀酸盐分别为29.3、40.9、63.6和82.5 g/L，表明随着初始富马酸盐浓度的增加而增加。在初始富马酸盐浓度为30 g/L时，仅4小时内就获得了96.8%/摩尔富马酸盐的高产率。将这些值与低细胞培养（0.2 g/L）获得的值进行比较，我们发现产生的琥珀酸盐量相似，但高细胞培养中的生产率比低细胞培养中的情况高约三倍。在CO2鼓泡条件下，该菌株将富马酸盐转化为琥珀酸盐的速率为3.5 g/L·h。
