Engineering Clostridial Aldehyde/Alcohol Dehydrogenase for Selective Butanol Production

Cited 15 time in webofscience Cited 12 time in scopus
  • Hit : 533
  • Download : 169
Butanol production by Clostridium acetobutylicum is accompanied by coproduction of acetone and ethanol, which reduces the yield of butanol and increases the production cost. Here, we report development of several clostridial aldehyde/alcohol dehydrogenase (AAD) variants showing increased butanol selectivity by a series of design and analysis procedures, including random mutagenesis, substrate specificity feature analysis, and structure-based butanol selectivity design. The butanol/ethanol ratios (B/E ratios) were dramatically increased to 17.47 and 15.91 g butanol/g ethanol for AAD(F716L) and AAD(N655H), respectively, which are 5.8-fold and 5.3fold higher than the ratios obtained with the wild-type AAD. The much-increased B/E ratio obtained was due to the dramatic reduction in ethanol production (0.59 +/- 0.01 g/liter) that resulted from engineering the substrate binding chamber and the active site of AAD. This protein design strategy can be applied generally for engineering enzymes to alter substrate selectivity. IMPORTANCE Renewable biofuel represents one of the answers to solving the energy crisis and climate change problems. Butanol produced naturally by clostridia has superior liquid fuel characteristics and thus has the potential to replace gasoline. Due to the lack of efficient genetic manipulation tools, however, clostridial strain improvement has been slower than improvement of other microorganisms. Furthermore, fermentation coproducing various by-products requires costly downstream processing for butanol purification. Here, we report the results of enzyme engineering of aldehyde/alcohol dehydrogenase (AAD) to increase butanol selectivity. A metabolically engineered Clostridium acetobutylicum strain expressing the engineered aldehyde/alcohol dehydrogenase gene was capable of producing butanol at a high level of selectivity.
Publisher
AMER SOC MICROBIOLOGY
Issue Date
2019-01
Language
English
Article Type
Article
Citation

MBIO, v.10, no.1, pp.1 - 12

ISSN
2150-7511
DOI
10.1128/mBio.02683-18
URI
http://hdl.handle.net/10203/254159
Appears in Collection
BiS-Journal Papers(저널논문)CBE-Journal Papers(저널논문)
Files in This Item
000460314300067.pdf(3.88 MB)Download
This item is cited by other documents in WoS
⊙ Detail Information in WoSⓡ Click to see webofscience_button
⊙ Cited 15 items in WoS Click to see citing articles in records_button

qr_code

  • mendeley

    citeulike


rss_1.0 rss_2.0 atom_1.0