[Enhancing alpha-ketoglutaric acid production in Torulopsis glabrata: increase of acetyl-CoA availability].
OBJECTIVE
This study aimed at increasing the alpha-ketoglutaric acid production of a multi-vitamin auxotrophic yeast Torulopsis glabrata, by increasing the availability of acetyl-CoA.


METHODS
For this, we expressed ACS2 encoding acetyl-CoA synthase from Saccharomyces cerevisiae in the pyruvate producer Torulopsis glabrata WSH-IP303.


RESULTS
Compared with that of the parent strain, the acetyl-CoA synthase activity of the mutant ACS2-1 increased about 920% and the mutant could use acetate as the sole carbon source for growth (2.6 g/L dry cell weight). When growing with glucose, the acetyl-CoA concentration, alpha-ketoglutaric acid, and the value of C(alpha-KG)/Cpyr were 222%, 105% and 152% higher than those of the parent strain WSH-IP303, respectively. The addition of 4 g/L acetate to the culture broth of mutant ACS-1 led to a significant increase of these values to 355%, 147% and 275%, respectively, compared with that of the parent strain WSH-IP303.


CONCLUSIONS
The alpha-ketoglutaric acid concentration reached 17.8 g/L by increasing the availability of acetyl-CoA and this strategy may provide an alternative approach to enhance metabolite production in yeast.
Liang
Nan
N
The Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China. xushishujun@163.com
Wang
Miao
M
Liu
Liming
L
Du
Guocheng
G
Chen
Jian
J
D000106:Acetate-CoA Ligase / Q000235:genetics / Q000378:metabolism; D000105:Acetyl Coenzyme A / Q000378:metabolism*; D041221:Candida glabrata / Q000166:cytology / Q000378:metabolism*; D049109:Cell Proliferation; D005947:Glucose / Q000378:metabolism; D007656:Ketoglutaric Acids / Q000378:metabolism*; D009154:Mutation; D010957:Plasmids / Q000235:genetics; D016133:Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae / Q000201:enzymology
D007656:Ketoglutaric Acids; D000105:Acetyl Coenzyme A; D000106:Acetate-CoA Ligase; D005947:Glucose