An ethanol-tolerant recombinant Escherichia coli expressing Zymomonas mobilis pdc and adhB genes for enhanced ethanol production from xylose.
An ethanol-tolerant mutant, ET1, was isolated by an enrichment method from Escherichia coli JM109. Strains JM109 and ET1 were transformed with expression vector pZY507bc containing Zymomonas mobilis alcohol dehydrogenase II (adhB) and pyruvate decarboxylase (pdc) genes, resulting in an ethanol-sensitive recombinant strain JMbc and an ethanol-tolerant recombinant strain, ET1bc. Alcohol dehydrogenase and pyruvate decarboxylase activities were 24 and 32% lower, respectively, in JMbc than in ET1bc. ET1bc fermented 10% (w/v) xylose to give 39.4 g ethanol/l (77%, theoretical yield), a 1.3-fold increase compared with the ethanol-sensitive strain JMbc.
Wang
Zhanchao
Z
College of Biological Sciences, China Agricultural University, Beijing 100094, P.R. China.
Chen
Ming
M
Xu
Yuquan
Y
Li
Shuying
S
Lu
Wei
W
Ping
Shuzhen
S
Zhang
Wei
W
Lin
Min
M
D000222:Adaptation, Physiological; D000426:Alcohol Dehydrogenase / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D015870:Gene Expression; D011767:Pyruvate Decarboxylase / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014994:Xylose / Q000378:metabolism*; D017355:Zymomonas / Q000235:genetics*
D001426:Bacterial Proteins; D011994:Recombinant Proteins; D000431:Ethanol; D014994:Xylose; D000426:Alcohol Dehydrogenase; D011767:Pyruvate Decarboxylase