CPL - Chalmers Publication Library
| Utbildning | Forskning | Styrkeområden | Om Chalmers | In English In English Ej inloggad.

Genetic and nutrient modulation of acetyl-CoA levels in Synechocystis for n-butanol production

J. Anfelt ; D. Kaczmarzyk ; K. Shabestary ; B. Renberg ; J. Rockberg ; Jens B. Nielsen (Institutionen för biologi och bioteknik, Systembiologi) ; M. Uhlen ; E. P. Hudson
Microbial Cell Factories (1475-2859). Vol. 14 (2015), p. 12.
[Artikel, refereegranskad vetenskaplig]

Background: There is a strong interest in using photosynthetic cyanobacteria as production hosts for biofuels and chemicals. Recent work has shown the benefit of pathway engineering, enzyme tolerance, and co-factor usage for improving yields of fermentation products. Results: An n-butanol pathway was inserted into a Synechocystis mutant deficient in polyhydroxybutyrate synthesis. We found that nitrogen starvation increased specific butanol productivity up to threefold, but cessation of cell growth limited total n-butanol titers. Metabolite profiling showed that acetyl-CoA increased twofold during nitrogen starvation. Introduction of a phosphoketolase increased acetyl-CoA levels sixfold at nitrogen replete conditions and increased butanol titers from 22 to 37 mg/L at day 8. Flux balance analysis of photoautotrophic metabolism showed that a Calvin-Benson-Bassham-Phosphoketolase pathway had higher theoretical butanol productivity than CBB-Embden-Meyerhof-Parnas and a reduced butanol ATP demand. Conclusion: These results demonstrate that phosphoketolase overexpression and modulation of nitrogen levels are two attractive routes toward increased production of acetyl-CoA derived products in cyanobacteria and could be implemented with complementary metabolic engineering strategies.

Nyckelord: Cyanobacteria, Butanol, Biofuel, Metabolic engineering, Phosphoketolase, Starvation



Denna post skapades 2016-01-07. Senast ändrad 2016-01-18.
CPL Pubid: 230026

 

Läs direkt!

Lokal fulltext (fritt tillgänglig)

Länk till annan sajt (kan kräva inloggning)


Institutioner (Chalmers)

Institutionen för biologi och bioteknik, Systembiologi

Ämnesområden

Mikrobiologi

Chalmers infrastruktur