TY - JOUR
T1 - Modification of carbon metabolism in Synechococcus elongatus PCC 7942 by cyanophage-derived sigma factors for bioproduction improvement
AU - Sawa, Naruhiko
AU - Tatsuke, Tsuneyuki
AU - Ogawa, Atsushi
AU - Hirokawa, Yasutaka
AU - Osanai, Takashi
AU - Hanai, Taizo
N1 - Funding Information:
This study was financially supported by the Core Research of Evolutional Science and Technology (CREST) program from the Japan Science and Technology Agency (JST) .
Publisher Copyright:
© 2018 The Society for Biotechnology, Japan
PY - 2019/2
Y1 - 2019/2
N2 - Many cyanophages, which infect cyanobacteria, most of possess putative sigma factors that have high amino acid sequence homology with the σ70-type sigma factor present in cyanobacteria, allowing them to obtain energy and metabolites for their own propagation. In this study, we aimed to modify the carbon metabolism of Synechococcus elongatus PCC 7942 by expressing putative sigma factors from Synechococcus phages to improve bioproduction. Four cyanophage-derived putative sigma factors—putative RpsD4 from Synechococcus phage S-CBS1, putative RpoD and putative RpoS from S-CBS2, and putative RpsD4 from S-CBS3—were selected for this purpose. These were introduced into S. elongatus PCC 7942, and their expression was controlled with a theophylline-dependent riboswitch. The expression of the putative RpoD from S-CBS2 and putative RpsD4 from S-CBS3 resulted in a significant decrease in the growth rate of S. elongatus PCC 7942. In addition, metabolome analysis showed a 3.2-fold increase in acetyl-CoA concentration with the expression of the putative RpoD from S-CBS2 and a 1.9-fold increase with the putative RpsD4 from S-CBS3. The results of RT-qPCR showed that several sugar metabolism genes were repressed by the putative RpoD and activated by the putative RpsD4. In particular, the engineered strain overexpressing the putative RpsD4 and expressing phosphate acetyltransferase succeeded in improving the productivity of the model target product acetate to 217% of its previous value. To the best of our knowledge, this study is the first to modify the metabolism of S. elongatus PCC 7942 by expressing their putative sigma factors from cyanophages.
AB - Many cyanophages, which infect cyanobacteria, most of possess putative sigma factors that have high amino acid sequence homology with the σ70-type sigma factor present in cyanobacteria, allowing them to obtain energy and metabolites for their own propagation. In this study, we aimed to modify the carbon metabolism of Synechococcus elongatus PCC 7942 by expressing putative sigma factors from Synechococcus phages to improve bioproduction. Four cyanophage-derived putative sigma factors—putative RpsD4 from Synechococcus phage S-CBS1, putative RpoD and putative RpoS from S-CBS2, and putative RpsD4 from S-CBS3—were selected for this purpose. These were introduced into S. elongatus PCC 7942, and their expression was controlled with a theophylline-dependent riboswitch. The expression of the putative RpoD from S-CBS2 and putative RpsD4 from S-CBS3 resulted in a significant decrease in the growth rate of S. elongatus PCC 7942. In addition, metabolome analysis showed a 3.2-fold increase in acetyl-CoA concentration with the expression of the putative RpoD from S-CBS2 and a 1.9-fold increase with the putative RpsD4 from S-CBS3. The results of RT-qPCR showed that several sugar metabolism genes were repressed by the putative RpoD and activated by the putative RpsD4. In particular, the engineered strain overexpressing the putative RpsD4 and expressing phosphate acetyltransferase succeeded in improving the productivity of the model target product acetate to 217% of its previous value. To the best of our knowledge, this study is the first to modify the metabolism of S. elongatus PCC 7942 by expressing their putative sigma factors from cyanophages.
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U2 - 10.1016/j.jbiosc.2018.07.019
DO - 10.1016/j.jbiosc.2018.07.019
M3 - Article
C2 - 30150148
AN - SCOPUS:85052208437
VL - 127
SP - 256
EP - 264
JO - Journal of Bioscience and Bioengineering
JF - Journal of Bioscience and Bioengineering
SN - 1389-1723
IS - 2
ER -