Abstract
Metabolic engineering of cyanobacteria has received much attention as a sustainable strategy to convert CO2 to various longer carbon chain fuels. Pinene has become increasingly attractive since pinene dimers contain high volumetric energy and have been proposed to act as potential aircraft fuels. However, cyanobacteria cannot directly convert geranyl pyrophosphate into pinene due to the lack of endogenous pinene synthase. Herein, we integrated the gene encoding Abies grandis pinene synthase into the model cyanobacterium Synechococcus sp. PCC 7002 through homologous recombination. The genetically modified cyanobacteria achieved a pinene titer of 1.525 ± 0.l45 mg L−1 in the lab-scale tube photobioreactor with CO2 aeration. Specifically, the results showed a mixture of α- and β-pinene (∼33:67 ratio). The ratio of β-pinene in the product was significantly increased compared with that previously reported in the engineered Escherichia coli. Furthermore, we investigated the photoautotrophic growth performances of Synechococcus overlaid with different concentrations of dodecane. The work demonstrates that the engineered Synechococcus is a suitable potential platform for β-pinene production.
Highlights
Growing concerns about environmental pollution issues and demands for alternative energy have stimulated photosynthetic organisms emerging as powerful platforms converting CO2 to various biobased products
A comparison of the modified Abies grandis PS (AgPS) gene sequence with the codon usage of Synechococcus was predicted with the Graphical Codon Usage Analyser (Fuhrmann et al, 2004), and the results showed that the relative adaptiveness values are all higher than 30% (Supplementary Material S1)
We directly amplified the modified AgPS gene from plasmid pAgGPPS-(GSG)2-AgPS and therewith integrated it into the pAQ1EX vector between the NdeI and BamHI sites
Summary
Growing concerns about environmental pollution issues and demands for alternative energy have stimulated photosynthetic organisms emerging as powerful platforms converting CO2 to various biobased products. As one of the oldest living phyla (Schopf and Packer, 1987), cyanobacteria are oxygenic photosynthetic autotrophic bacteria widely distributed in aquatic and terrestrial habitats (Díez and Ininbergs, 2014). They play a crucial role in the biogeochemical cycles of carbon and nitrogen with the capacity of fixing carbon dioxide and atmospheric nitrogen (Parmar et al, 2011). The increasingly abounding toolboxes for genetic manipulation impel cyanobacteria to become attractive platforms for bio-based production (Markley et al, 2015; Carroll et al, 2018; Sun et al, 2018; Xia et al, 2019).
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
