Comparing the xylose reductase/xylitol dehydrogenase and xylose isomerase pathways in arabinose and xylose fermenting Saccharomyces cerevisiae strains.
Comparing the xylose reductase/xylitol dehydrogenase and xylose isomerase pathways in arabinose and xylose fermenting Saccharomyces cerevisiae strains.
复制标题
DOI：
10.1186/1754-6834-1-16
复制
发表时间：
2008-10-23
影响因子：
6.3
通讯作者：
Gorwa-Grauslund MF
中科院分区：
文献类型：
--
作者：
Bettiga M;Hahn-Hägerdal B;Gorwa-Grauslund MF
木质纤维素生物质的乙醇发酵是生产生物乙醇的一种可持续选择。该工艺将极大地受益于重组酿酒酵母菌株，除了己糖部分外，还能发酵戊糖、阿拉伯糖和木糖。酿酒酵母可以通过不同途径利用阿拉伯糖和木糖。在本研究中，在基因相同的菌株中，细菌阿拉伯糖异构酶途径分别与木糖还原酶/木糖醇脱氢酶和木糖异构酶两种不同的木糖利用途径相结合。比较了两株菌株在阿拉伯糖和木糖的好氧分批培养和葡萄糖、阿拉伯糖和木糖混合物的厌氧分批发酵中的生长情况。木糖还原酶/木糖醇脱氢酶和木糖异构酶菌株的需氧阿拉伯糖生长速率相同，均为0.03 h-1。木糖还原酶/木糖醇脱氢酶菌株在木糖上的好氧生长速率为0.14 h-1，在厌氧间歇发酵中木糖的特定消耗速率为0.09 g (g cells)-1h-1，而木糖异构酶菌株仅为0.03 h-1和0.02 g (g cells)-1h-1。木糖还原酶/木糖醇脱氢酶菌株对总糖的乙醇产量更高，为0.23 g-1，木糖异构酶菌株为0.18 g-1；木糖异构酶菌株对消耗糖的乙醇产量更高，为0.41 g-1，木糖还原酶/木糖醇脱氢酶菌株为0.32 g-1。葡萄糖、阿拉伯糖和木糖混合厌氧发酵产生更高的最终乙醇浓度，木糖还原酶/木糖醇脱氢酶菌株为14.7 g l-1，木糖异构酶菌株为11.8 g l-1；在更高的比乙醇产量方面，木糖还原酶/木糖醇脱氢酶菌株为0.024 g （g细胞）-1 h-1，木糖异构酶菌株为0.01 g （g细胞）-1 h-1。木糖还原酶/木糖醇脱氢酶途径与细菌阿拉伯糖异构体酶途径的结合比木糖异构体酶途径与细菌阿拉伯糖异构体酶途径的结合产生更高的戊糖摄取和更高的总乙醇产量。此外，当与木糖异构酶途径结合时，通过细菌阿拉伯糖途径的通量没有增加。这表明细菌阿拉伯糖途径的低活性不能归因于通过木糖还原酶形成阿拉伯糖醇。
Ethanolic fermentation of lignocellulosic biomass is a sustainable option for the production of bioethanol. This process would greatly benefit from recombinant Saccharomyces cerevisiae strains also able to ferment, besides the hexose sugar fraction, the pentose sugars, arabinose and xylose. Different pathways can be introduced in S. cerevisiae to provide arabinose and xylose utilisation. In this study, the bacterial arabinose isomerase pathway was combined with two different xylose utilisation pathways: the xylose reductase/xylitol dehydrogenase and xylose isomerase pathways, respectively, in genetically identical strains. The strains were compared with respect to aerobic growth in arabinose and xylose batch culture and in anaerobic batch fermentation of a mixture of glucose, arabinose and xylose. The specific aerobic arabinose growth rate was identical, 0.03 h-1, for the xylose reductase/xylitol dehydrogenase and xylose isomerase strain. The xylose reductase/xylitol dehydrogenase strain displayed higher aerobic growth rate on xylose, 0.14 h-1, and higher specific xylose consumption rate in anaerobic batch fermentation, 0.09 g (g cells)-1 h-1 than the xylose isomerase strain, which only reached 0.03 h-1 and 0.02 g (g cells)-1h-1, respectively. Whereas the xylose reductase/xylitol dehydrogenase strain produced higher ethanol yield on total sugars, 0.23 g g-1 compared with 0.18 g g-1 for the xylose isomerase strain, the xylose isomerase strain achieved higher ethanol yield on consumed sugars, 0.41 g g-1 compared with 0.32 g g-1 for the xylose reductase/xylitol dehydrogenase strain. Anaerobic fermentation of a mixture of glucose, arabinose and xylose resulted in higher final ethanol concentration, 14.7 g l-1 for the xylose reductase/xylitol dehydrogenase strain compared with 11.8 g l-1 for the xylose isomerase strain, and in higher specific ethanol productivity, 0.024 g (g cells)-1 h-1 compared with 0.01 g (g cells)-1 h-1 for the xylose reductase/xylitol dehydrogenase strain and the xylose isomerase strain, respectively. The combination of the xylose reductase/xylitol dehydrogenase pathway and the bacterial arabinose isomerase pathway resulted in both higher pentose sugar uptake and higher overall ethanol production than the combination of the xylose isomerase pathway and the bacterial arabinose isomerase pathway. Moreover, the flux through the bacterial arabinose pathway did not increase when combined with the xylose isomerase pathway. This suggests that the low activity of the bacterial arabinose pathway cannot be ascribed to arabitol formation via the xylose reductase enzyme.
登录
查看更多内容
影响因子：
3.8
作者：
Jeppsson, M;Bengtsson, O;Gorwa-Grauslund, MF
通讯作者：
Gorwa-Grauslund, MF
影响因子：
4.4
作者：
Becker, J;Boles, E
通讯作者：
Boles, E
影响因子：
2.6
作者：
Karhumaa, K;Hahn-Hägerdal, B;Gorwa-Grauslund, MF
通讯作者：
Gorwa-Grauslund, MF
DOI：
10.1016/0006-3002(59)90395-6
发表时间：
1959-01-01
期刊：
BIOCHIMICA ET BIOPHYSICA ACTA
影响因子：
--
作者：
CHIANG, C;KNIGHT, SG
通讯作者：
KNIGHT, SG
DOI：
10.1016/0006-3002(61)90750-8
发表时间：
1961-01-01
期刊：
BIOCHIMICA ET BIOPHYSICA ACTA
影响因子：
--
作者：
CHIANG, C;KNIGHT, SG
通讯作者：
KNIGHT, SG