AUTHOR=Yang Ruigang , Zhu Lingyun , Li Tao , Zhu Lv-yun , Ye Zi , Zhang Dongyi 

TITLE=Photosynthetic Conversion of CO2 Into Pinene Using Engineered Synechococcus sp. PCC 7002

JOURNAL=Frontiers in Bioengineering and Biotechnology

VOLUME=9

YEAR=2021

URL=https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2021.779437

DOI=10.3389/fbioe.2021.779437

ISSN=2296-4185

ABSTRACT=<p>Metabolic engineering of cyanobacteria has received much attention as a sustainable strategy to convert CO<sub>2</sub> 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 <italic>Abies grandis</italic> pinene synthase into the model cyanobacterium <italic>Synechococcus</italic> sp. PCC 7002 through homologous recombination. The genetically modified cyanobacteria achieved a pinene titer of 1.525 ± 0.l45 mg L<sup>−1</sup> in the lab-scale tube photobioreactor with CO<sub>2</sub> aeration. Specifically, the results showed a mixture of <italic>α</italic>- and <italic>β</italic>-pinene (∼33:67 ratio). The ratio of <italic>β</italic>-pinene in the product was significantly increased compared with that previously reported in the engineered <italic>Escherichia coli</italic>. Furthermore, we investigated the photoautotrophic growth performances of <italic>Synechococcus</italic> overlaid with different concentrations of dodecane. The work demonstrates that the engineered <italic>Synechococcus</italic> is a suitable potential platform for <italic>β</italic>-pinene production.</p>