Production of L-2,3-butanediol by a new pathway constructed in Escherichia coli.
OBJECTIVE
A metabolic pathway for L-2,3-butanediol (BD) as the main product has not yet been found. To rectify this situation, we attempted to produce L-BD from diacetyl (DA) by producing simultaneous expression of diacetyl reductase (DAR) and L-2,3-butanediol dehydrogenase (BDH) using transgenic bacteria, Escherichia coli JM109/pBUD-comb.


RESULTS
The meso-BDH of Klebsiella pneumoniae was used for its DAR activity to convert DA to L-acetoin (AC) and the L-BDH of Brevibacterium saccharolyticum was used to reduce L-AC to L-BD. The respective gene coding each enzyme was connected in tandem to the MCS of pFLAG-CTC (pBUD-comb). The divided addition of DA as a source, addition of 2% glucose, and the combination of static and shaking culture was effective for the production.


CONCLUSIONS
L-BD (2200 mg l(-1)) was generated from 3000 mg l(-1) added of DA, which corresponded to a 73% conversion rate. Meso-BD as a by-product was mixed by 2% at most.


CONCLUSIONS
An enzyme system for converting DA to L-BD was constructed with a view to using DA-producing bacteria in the future.
Ui
S
S
Department of Applied Chemistry and Biotechnology, Faculty of Engineering, Yamanashi University, Kofu, Yamanashi, Japan. ui@ab11.yamanashi.ac.jp
Takusagawa
Y
Y
Sato
T
T
Ohtsuki
T
T
Mimura
A
A
Ohkuma
M
M
Kudo
T
T
D000094:Acetoin Dehydrogenase / Q000235:genetics / Q000378:metabolism; D000429:Alcohol Oxidoreductases / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics; D001951:Brevibacterium / Q000201:enzymology / Q000235:genetics; D002072:Butylene Glycols / Q000378:metabolism*; D003001:Cloning, Molecular; D003931:Diacetyl / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism*; D005285:Fermentation; D005822:Genetic Vectors; D007700:Kinetics; D007711:Klebsiella pneumoniae / Q000201:enzymology / Q000235:genetics; D010957:Plasmids; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013237:Stereoisomerism
D001426:Bacterial Proteins; D002072:Butylene Glycols; D011994:Recombinant Proteins; C026978:2,3-butylene glycol; D000429:Alcohol Oxidoreductases; D000094:Acetoin Dehydrogenase; C019801:butanediol dehydrogenase; D003931:Diacetyl