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- Wegelius, Adam, et al.
(författare)
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Design and characterization of a synthetic minimal promoter for heterocyst-specific expression in filamentous cyanobacteria
- 2018
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 13:9
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Tidskriftsartikel (refereegranskat)abstract
- Short and well defined promoters are essential for advancing cyanobacterial biotechnology. The heterocyst of Nostoc sp. is suggested as a microbial cell factory for oxygen sensitive catalysts, such as hydrogenases for hydrogen production, due to its microoxic environment. We identified and predicted promoter elements of possible significance through a consensus strategy using a pool of heterocyst-induced DIF+ promoters known from Anabaena sp. PCC 7120. To test if these conserved promoter elements were crucial for heterocyst-specific expression, promoter-yfp reporter constructs were designed. The characterization was accomplished by replacing, -35 and -10 regions and the upstream element, with well described elements from the trc promoter of Escherichia coli, which is also functional in Nostoc sp. From the in vivo spatial fluorescence of the different promoter-yfp reporters in Nostoc punctiforme ATCC 29133, we concluded that both the consensus -35 and extended -10 regions were important for heterocyst-specific expression. Further that the promoter strength could be improved by the addition of an upstream element. We designed a short synthetic promoter of 48 nucleotides, PsynDIF, including a consensus DIF1 sequence, a 17 base pair stretch of random nucleotides and an extended consensus -10 region, and thus generated the shortest promoter for heterocyst-specific expression to date.
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| 2. |
- Wegelius, Adam, et al.
(författare)
-
Generation of a functional, semisynthetic [FeFe]-hydrogenase in a photosynthetic microorganism
- 2018
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Ingår i: Energy & Environmental Science. - : Royal Society of Chemistry (RSC). - 1754-5692 .- 1754-5706. ; 11:11, s. 3163-3167
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Tidskriftsartikel (refereegranskat)abstract
- [FeFe]-Hydrogenases are hydrogen producing metalloenzymes with excellent catalytic capacities, highly relevant in the context of a future hydrogen economy. Here we demonstrate the synthetic activation of a heterologously expressed [FeFe]-hydrogenase in living cells of Synechocystis PCC 6803, a photoautotrophic microbial chassis with high potential for biotechnological energy applications. H-2-Evolution assays clearly show that the non-native, semi-synthetic enzyme links to the native metabolism in living cells.
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