Modular pathway engineering of Corynebacterium glutamicum to improve xylose utilization and succinate production.
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.
Clean Energy Research Center, Korea Institute of Science and Technology, Hwarang-ro 14-gil 5, Seongbuk-gu, Seoul 02792, Republic of Korea; Department of Biotechnology, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea.
Suah
S
Jo
Department of Food Science and Biotechnology, Sungkyunkwan University (SKKU), 2066 Seobu-ro, Jangan-gu, Suwon 16419, Republic of Korea.
Jinkyung
J
Yoon
Clean Energy Research Center, Korea Institute of Science and Technology, Hwarang-ro 14-gil 5, Seongbuk-gu, Seoul 02792, Republic of Korea.
Sun-Mi
SM
Lee
Clean Energy Research Center, Korea Institute of Science and Technology, Hwarang-ro 14-gil 5, Seongbuk-gu, Seoul 02792, Republic of Korea.
Youngsoon
Y
Um
Department of Biotechnology, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea.
Sung Ok
SO
Han
Department of Food Science and Biotechnology, Sungkyunkwan University (SKKU), 2066 Seobu-ro, Jangan-gu, Suwon 16419, Republic of Korea. Electronic address: hmwoo@skku.edu.
Han Min
HM
Woo
D000446:Aldehyde-Lyases / Q000235:genetics / Q000378:metabolism; D001233:Aspergillus nidulans / Q000201:enzymology / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D000070005:Bifidobacterium adolescentis / Q000201:enzymology / Q000235:genetics; D048230:Corynebacterium glutamicum / Q000235:genetics* / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D060847:Metabolic Engineering / Q000379:methods*; D010427:Pentose Phosphate Pathway / Q000235:genetics; D010734:Phosphogluconate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D019802:Succinic Acid / Q000032:analysis / Q000378:metabolism*; D014153:Transaldolase / Q000235:genetics / Q000378:metabolism; D014994:Xylose / Q000378:metabolism*
D001426:Bacterial Proteins; D005656:Fungal Proteins; D011994:Recombinant Proteins; D014994:Xylose; D019802:Succinic Acid; D010734:Phosphogluconate Dehydrogenase; D014153:Transaldolase; D000446:Aldehyde-Lyases; C022367:phosphoketolase
Corynebacterium glutamicum; Metabolic engineering; Phosphoketolase; Synthetic biology; Xylose utilization