TY - JOUR
T1 - A microbial platform for renewable propane synthesis based on a fermentative butanol pathway
AU - Menon, Navya
AU - Pásztor, András
AU - Menon, Binuraj R. K.
AU - Kallio, Pauli
AU - Fisher, Karl
AU - Akhtar, M. Kalim
AU - Leys, David
AU - Jones, Patrik R.
AU - Scrutton, Nigel S.
N1 - Funding Information:
The work was supported by a grant from the European Union FP-7 256808 to NSS and PRJ. NSS is an Engineering and Physical Sciences Research Council Established Career Fellow.
Publisher Copyright:
© 2015 Menon et al.; licensee BioMed Central.
PY - 2015/4/10
Y1 - 2015/4/10
N2 - Background: Propane (C3H8) is a volatile hydrocarbon with highly favourable physicochemical properties as a fuel, in addition to existing global markets and infrastructure for storage, distribution and utilization in a wide range of applications. Consequently, propane is an attractive target product in research aimed at developing new renewable alternatives to complement currently used petroleum-derived fuels. This study focuses on the construction and evaluation of alternative microbial biosynthetic pathways for the production of renewable propane. The new pathways utilize CoA intermediates that are derived from clostridial-like fermentative butanol pathways and are therefore distinct from the first microbial propane pathways recently engineered in Escherichia coli. Results: We report the assembly and evaluation of four different synthetic pathways for the production of propane and butanol, designated a) atoB-adhE2 route, b) atoB-TPC7 route, c) nphT7-adhE2 route and d) nphT7-TPC7 route. The highest butanol titres were achieved with the atoB-adhE2 (473 ± 3 mg/L) and atoB-TPC7 (163 ± 2 mg/L) routes. When aldehyde deformylating oxygenase (ADO) was co-expressed with these pathways, the engineered hosts also produced propane. The atoB-TPC7-ADO pathway was the most effective in producing propane (220 ± 3 μg/L). By (i) deleting competing pathways, (ii) including a previously designed ADOA134F variant with an enhanced specificity towards short-chain substrates and (iii) including a ferredoxin-based electron supply system, the propane titre was increased (3.40 ± 0.19 mg/L). Conclusions: This study expands the metabolic toolbox for renewable propane production and provides new insight and understanding for the development of next-generation biofuel platforms. In developing an alternative CoA-dependent fermentative butanol pathway, which includes an engineered ADO variant (ADOA134F), the study addresses known limitations, including the low bio-availability of butyraldehyde precursors and poor activity of ADO with butyraldehyde. Graphical abstract Propane synthesis derived from a fermentative butanol pathway is enabled by metabolic engineering.
AB - Background: Propane (C3H8) is a volatile hydrocarbon with highly favourable physicochemical properties as a fuel, in addition to existing global markets and infrastructure for storage, distribution and utilization in a wide range of applications. Consequently, propane is an attractive target product in research aimed at developing new renewable alternatives to complement currently used petroleum-derived fuels. This study focuses on the construction and evaluation of alternative microbial biosynthetic pathways for the production of renewable propane. The new pathways utilize CoA intermediates that are derived from clostridial-like fermentative butanol pathways and are therefore distinct from the first microbial propane pathways recently engineered in Escherichia coli. Results: We report the assembly and evaluation of four different synthetic pathways for the production of propane and butanol, designated a) atoB-adhE2 route, b) atoB-TPC7 route, c) nphT7-adhE2 route and d) nphT7-TPC7 route. The highest butanol titres were achieved with the atoB-adhE2 (473 ± 3 mg/L) and atoB-TPC7 (163 ± 2 mg/L) routes. When aldehyde deformylating oxygenase (ADO) was co-expressed with these pathways, the engineered hosts also produced propane. The atoB-TPC7-ADO pathway was the most effective in producing propane (220 ± 3 μg/L). By (i) deleting competing pathways, (ii) including a previously designed ADOA134F variant with an enhanced specificity towards short-chain substrates and (iii) including a ferredoxin-based electron supply system, the propane titre was increased (3.40 ± 0.19 mg/L). Conclusions: This study expands the metabolic toolbox for renewable propane production and provides new insight and understanding for the development of next-generation biofuel platforms. In developing an alternative CoA-dependent fermentative butanol pathway, which includes an engineered ADO variant (ADOA134F), the study addresses known limitations, including the low bio-availability of butyraldehyde precursors and poor activity of ADO with butyraldehyde. Graphical abstract Propane synthesis derived from a fermentative butanol pathway is enabled by metabolic engineering.
KW - aldehyde deformylating oxygenase
KW - butanol
KW - cyanobacteria
KW - escherchia coli
KW - microbial pathway engineering
KW - propane
UR - http://www.scopus.com/inward/record.url?scp=84926669094&partnerID=8YFLogxK
U2 - 10.1186/s13068-015-0231-1
DO - 10.1186/s13068-015-0231-1
M3 - Article
AN - SCOPUS:84926669094
SN - 1754-6834
VL - 8
JO - Biotechnology for Biofuels
JF - Biotechnology for Biofuels
IS - 1
M1 - 61
ER -
