TY - JOUR
T1 - Modular pathway engineering of Corynebacterium glutamicum to improve xylose utilization and succinate production
AU - Jo, Suah
AU - Yoon, Jinkyung
AU - Lee, Sun Mi
AU - Um, Youngsoon
AU - Han, Sung Ok
AU - Woo, Han Min
PY - 2017/9/20
Y1 - 2017/9/20
N2 - Xylose-negative Corynebacterium glutamicum has been engineered to utilize xylose as the sole carbon source via either the xylose isomerase (XI) pathway or the Weimberg pathway. Heterologous expression of xylose isomerase and overexpression of a gene encoding for xylulose kinase enabled efficient xylose utilization. In this study, we show that two functionally-redundant transcriptional regulators (GntR1 and GntR2) present on xylose repress the pentose phosphate pathway genes. For efficient xylose utilization, pentose phosphate pathway genes and a phosphoketolase gene were overexpressed with the XI pathway in C. glutamicum. Overexpression of the genes encoding for transaldolase (Tal), 6-phosphogluconate dehydrogenase (Gnd), or phosphoketolase (XpkA) enhanced the growth and xylose consumption rates compared to the wild-type with the XI pathway alone. However, co-expression of these genes did not have a synergetic effect on xylose utilization. For the succinate production from xylose, overexpression of the tal gene with the XI pathway in a succinate-producing strain improved xylose utilization and increased the specific succinate production rate by 2.5-fold compared to wild-type with the XI pathway alone. Thus, overexpression of the tal, gnd, or xpkA gene could be helpful for engineering C. glutamicum toward production of value-added chemicals with efficient xylose utilization.
AB - Xylose-negative Corynebacterium glutamicum has been engineered to utilize xylose as the sole carbon source via either the xylose isomerase (XI) pathway or the Weimberg pathway. Heterologous expression of xylose isomerase and overexpression of a gene encoding for xylulose kinase enabled efficient xylose utilization. In this study, we show that two functionally-redundant transcriptional regulators (GntR1 and GntR2) present on xylose repress the pentose phosphate pathway genes. For efficient xylose utilization, pentose phosphate pathway genes and a phosphoketolase gene were overexpressed with the XI pathway in C. glutamicum. Overexpression of the genes encoding for transaldolase (Tal), 6-phosphogluconate dehydrogenase (Gnd), or phosphoketolase (XpkA) enhanced the growth and xylose consumption rates compared to the wild-type with the XI pathway alone. However, co-expression of these genes did not have a synergetic effect on xylose utilization. For the succinate production from xylose, overexpression of the tal gene with the XI pathway in a succinate-producing strain improved xylose utilization and increased the specific succinate production rate by 2.5-fold compared to wild-type with the XI pathway alone. Thus, overexpression of the tal, gnd, or xpkA gene could be helpful for engineering C. glutamicum toward production of value-added chemicals with efficient xylose utilization.
KW - Corynebacterium glutamicum
KW - Metabolic engineering
KW - Phosphoketolase
KW - Synthetic biology
KW - Xylose utilization
UR - http://www.scopus.com/inward/record.url?scp=85011349337&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85011349337&partnerID=8YFLogxK
U2 - 10.1016/j.jbiotec.2017.01.015
DO - 10.1016/j.jbiotec.2017.01.015
M3 - Article
C2 - 28153765
AN - SCOPUS:85011349337
VL - 258
SP - 69
EP - 78
JO - Journal of Biotechnology
JF - Journal of Biotechnology
SN - 0168-1656
ER -