Abstract
Alternative microbial hosts have been engineered as biocatalysts for butanol biosynthesis. The butanol synthetic pathway of Clostridium acetobutylicum was first re-constructed in Escherichia coli to establish a baseline for comparison to other hosts. Whereas polycistronic expression of the pathway genes resulted in the production of 34 mg/L butanol, individual expression of pathway genes elevated titers to 200 mg/L. Improved titers were achieved by co-expression of Saccharomyces cerevisiae formate dehydrogenase while overexpression of E. coli glyceraldehyde 3-phosphate dehydrogenase to elevate glycolytic flux improved titers to 580 mg/L. Pseudomonas putida and Bacillus subtilis were also explored as alternative production hosts. Polycistronic expression of butanol biosynthetic genes yielded butanol titers of 120 and 24 mg/L from P. putida and B. subtilis, respectively. Production in the obligate aerobe P. putida was dependent upon expression of bcd-etfAB. These results demonstrate the potential of engineering butanol biosynthesis in a variety of heterologous microorganisms, including those cultivated aerobically.
Original language | English (US) |
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Pages (from-to) | 262-273 |
Number of pages | 12 |
Journal | Metabolic Engineering |
Volume | 11 |
Issue number | 4-5 |
DOIs | |
State | Published - Jul 2009 |
Externally published | Yes |
Keywords
- B. subtilis
- Biofuel
- Butanol
- E. coli
- P. putida
- Product inhibition
- Tolerance
ASJC Scopus subject areas
- Biotechnology
- Bioengineering
- Applied Microbiology and Biotechnology