Maximizing PHB content in Synechocystis sp. PCC 6803: a new metabolic engineering strategy based on the regulator PirC.
Biopolymers
Cyanobacteria
Metabolic engineering
PHB
Sustainable
Synechocystis 6803
Journal
Microbial cell factories
ISSN: 1475-2859
Titre abrégé: Microb Cell Fact
Pays: England
ID NLM: 101139812
Informations de publication
Date de publication:
22 Dec 2020
22 Dec 2020
Historique:
received:
16
10
2020
accepted:
02
12
2020
entrez:
23
12
2020
pubmed:
24
12
2020
medline:
29
6
2021
Statut:
epublish
Résumé
PHB (poly-hydroxy-butyrate) represents a promising bioplastic alternative with good biodegradation properties. Furthermore, PHB can be produced in a completely carbon-neutral fashion in the natural producer cyanobacterium Synechocystis sp. PCC 6803. This strain has been used as model system in past attempts to boost the intracellular production of PHB above ~ 15% per cell-dry-weight (CDW). We have created a new strain that lacks the regulatory protein PirC (product of sll0944), which exhibits a higher activity of the phosphoglycerate mutase resulting in increased PHB pools under nutrient limiting conditions. To further improve the intracellular PHB content, two genes involved in PHB metabolism, phaA and phaB, from the known producer strain Cupriavidus necator, were introduced under the control of the strong promotor PpsbA2. The resulting strain, termed PPT1 (ΔpirC-REphaAB), produced high amounts of PHB under continuous light as well under a day-night regime. When grown in nitrogen and phosphorus depleted medium, the cells produced up to 63% per CDW. Upon the addition of acetate, the content was further increased to 81% per CDW. The produced polymer consists of pure PHB, which is highly isotactic. The amounts of PHB achieved with PPT1 are the highest ever reported in any known cyanobacterium and demonstrate the potential of cyanobacteria for a sustainable, industrial production of PHB.
Sections du résumé
BACKGROUND
BACKGROUND
PHB (poly-hydroxy-butyrate) represents a promising bioplastic alternative with good biodegradation properties. Furthermore, PHB can be produced in a completely carbon-neutral fashion in the natural producer cyanobacterium Synechocystis sp. PCC 6803. This strain has been used as model system in past attempts to boost the intracellular production of PHB above ~ 15% per cell-dry-weight (CDW).
RESULTS
RESULTS
We have created a new strain that lacks the regulatory protein PirC (product of sll0944), which exhibits a higher activity of the phosphoglycerate mutase resulting in increased PHB pools under nutrient limiting conditions. To further improve the intracellular PHB content, two genes involved in PHB metabolism, phaA and phaB, from the known producer strain Cupriavidus necator, were introduced under the control of the strong promotor PpsbA2. The resulting strain, termed PPT1 (ΔpirC-REphaAB), produced high amounts of PHB under continuous light as well under a day-night regime. When grown in nitrogen and phosphorus depleted medium, the cells produced up to 63% per CDW. Upon the addition of acetate, the content was further increased to 81% per CDW. The produced polymer consists of pure PHB, which is highly isotactic.
CONCLUSION
CONCLUSIONS
The amounts of PHB achieved with PPT1 are the highest ever reported in any known cyanobacterium and demonstrate the potential of cyanobacteria for a sustainable, industrial production of PHB.
Identifiants
pubmed: 33353555
doi: 10.1186/s12934-020-01491-1
pii: 10.1186/s12934-020-01491-1
pmc: PMC7756911
doi:
Substances chimiques
Bacterial Proteins
0
Hydroxybutyrates
0
Polymers
0
Carbon
7440-44-0
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
231Subventions
Organisme : DFG
ID : DFG grant Fo195/9-2
Organisme : RTG Molecular principles of bacterial survival strategies
ID : 1708
Références
Life (Basel). 2020 Apr 22;10(4):
pubmed: 32331427
Proc Natl Acad Sci U S A. 1984 Mar;81(5):1561-5
pubmed: 6324204
Bioresour Technol. 2006 Jul;97(11):1296-301
pubmed: 16046119
DNA Res. 2013 Dec;20(6):525-35
pubmed: 23861321
Metabolites. 2013 Feb 06;3(1):101-18
pubmed: 24957892
Curr Biol. 2016 Nov 7;26(21):2862-2872
pubmed: 27720620
Int J Mol Sci. 2019 Apr 20;20(8):
pubmed: 31010017
Environ Sci Technol. 2018 Sep 18;52(18):10441-10452
pubmed: 30156110
Bioresour Technol. 2001 Jan;76(2):85-90
pubmed: 11131804
Nat Methods. 2009 May;6(5):343-5
pubmed: 19363495
Bioresour Technol. 2018 Oct;266:34-44
pubmed: 29957289
AMB Express. 2017 Dec;7(1):143
pubmed: 28687036
Arch Microbiol. 1998 Sep;170(3):162-70
pubmed: 9683655
Photosynth Res. 2018 Jun;136(3):303-314
pubmed: 29124651
Bioresour Technol. 2011 Dec;102(23):11039-42
pubmed: 21983412
Mol Microbiol. 1998 Mar;27(6):1193-202
pubmed: 9570404
Arch Mikrobiol. 1969;69(2):114-20
pubmed: 4986616
Sci Total Environ. 2016 Oct 1;566-567:333-349
pubmed: 27232963
Chem Soc Rev. 2009 Aug;38(8):2434-46
pubmed: 19623359
PLoS One. 2014 Jan 22;9(1):e86368
pubmed: 24466058
Sci Adv. 2017 Jul 19;3(7):e1700782
pubmed: 28776036
Int J Biol Macromol. 2002 Apr 8;30(2):97-104
pubmed: 11911900
Plant Physiol. 2018 Jun;177(2):594-603
pubmed: 29703865
Bioengineering (Basel). 2018 Dec 18;5(4):
pubmed: 30567391
Plant Physiol. 2014 Apr;164(4):1831-41
pubmed: 24521880
Bioresour Technol. 2016 Jul;212:342-347
pubmed: 27130227
Science. 2015 Feb 13;347(6223):768-71
pubmed: 25678662
FEMS Microbiol Lett. 2017 Nov 1;364(20):
pubmed: 28961962
Sci Rep. 2020 Apr 3;10(1):5932
pubmed: 32246065
Plant Physiol. 2020 Dec;184(4):1792-1810
pubmed: 32900980
Bioresour Technol. 2016 Aug;214:761-768
pubmed: 27213577