The cyanobacterial genus Synechocystis is of particular interest to science and industry because of its efficient phototrophic metabolism, its accumulation of the polymer poly(3-hydroxybutyrate) (PHB) and its ability to withstand or adapt to adverse growing conditions. One such condition is the increased salinity that can be caused by recycled or brackish water used in cultivation. While overall reduced growth is expected in response to salt stress, other metabolic responses relevant to the efficiency of phototrophic production of biomass or PHB (or both) have been experimentally observed in three Synechocystis strains at stepwise increasing salt concentrations. In response to recent reports on metabolic strategies to increase stress tolerance of heterotrophic and phototrophic bacteria, we focused particularly on the stress-induced response of Synechocystis strains in terms of PHB, glycogen and photoactive pigment dynamics. Of the three strains studied, the strain Synechocystis cf. salina CCALA192 proved to be the most tolerant to salt stress. In addition, this strain showed the highest PHB accumulation. All the three strains accumulated more PHB with increasing salinity, to the point where their photosystems were strongly inhibited and they could no longer produce enough energy to synthesize more PHB.

BEST Bioenergy and Sustainable Technologies GmbH Inffeldgasse 21b 8010 Graz Austria

Faculty of Chemistry Brno University of Technology Purkynova 118 612 00 Brno Czech Republic

Faculty of Science Charles University Vinicna 7 128 44 Prague 2 Czech Republic

Institute of Environmental Biotechnology Department of Agrobiotechnology IFA Tulln University of Natural Resources and Life Sciences Vienna Konrad Lorenz Straße 20 3430 Tulln Austria

Institute of Parasitology Biology Centre The Czech Academy of Sciences Branisovska 31 37005 Ceske Budejovice Czech Republic

Institute of Scientific Instruments The Czech Academy of Sciences Královopolská 147 61264 Brno Czech Republic

Zobrazit více v PubMed

Allakhverdiev SI, Murata N. Salt stress inhibits photosystems II and I in cyanobacteria. Photosynth Res. 2008;98:529–539. doi: 10.1007/s11120-008-9334-x. PubMed DOI

Allakhverdiev SI, Nishiyama Y, Miyairi S, Yamamoto H, Ingagaki N, Kanesaki Y, Murata N (2002) Salt stress inhibits the repair of photodamaged Photosystem II by suppressing the transcription and translation of psbA genes in Synechocystis. Plant Physiol 130:1443–1453 PubMed PMC

Bennett A, Bogorad L (1973) Complementary chromatic adaptation in a filamentous blue-green alga. J Cell Biol 58:419–435 PubMed PMC

Damrow R, Maldener I, Zilliges Y (2016) The multiple functions of common microbial carbon polymers, glycogen and PHB, during stress responses in the non-diazotrophic cyanobacterium Synechocystis sp. PCC 6803. Front Microbiol 7:966 PubMed PMC

Dutt V, Srivastava S. Novel quantitative insights into carbon sources for synthesis of poly hydroxybutyrate in Synechocystis PCC 6803. Photosynth Res. 2018;136:303–314. doi: 10.1007/s11120-017-0464-x. PubMed DOI

Fritz I, Meixner K, Neureiter M, Drosg B (2021) Comparing heterotrophic with phototrophic PHA production - Concurring or complementing strategies? In: Koller M (ed) The Handbook of Polyhydroxyalkanoates - Microbial Biosynthesis and Feedstocks, 1st edn. CRC Press, p 453

Fulda S, Huang F, Nilsson F, Persson AL, Pakrasi HB, Andersson B, Norling B. Proteomics of Synechocystis sp. strain PCC 6803. Eur J Biochem. 2000;267:5900–5907. doi: 10.1046/j.1432-1327.2000.01642.x. PubMed DOI

Gänzle M (2021) Carrez-Klärung. In: Böckler F, Dill B, Eisenbrand G, et al. (eds) RÖMPP Lexikon [online]. Georg Thieme Verlag, Stuttgart. https://roempp.thieme.de/DCUK7

Hagemann M, Jeanjean R, Fulda S, Havaux M, Joset F, Erdmann N. Flavodoxin accumulation contributes to enhanced cyclic electron flow around photosystem I in salt-stressed cells of Synechocystis sp. strain PCC 6803. Physiol Plant. 1999;105:670–678. doi: 10.1034/j.1399-3054.1999.105411.x. DOI

Hrubanova K, Nebesarova J, Ruzicka F, Krzyzanek V (2018) The innovation of cryo-SEM freeze-fracturing methodology demonstrated on high pressure frozen biofilm. Micron 110:28–35 PubMed

Huang F, Fulda S, Hagemann M, Norling B. Proteomic screening of salt-stress-induced changes in plasma membranes of Synechocystis sp. strain PCC 6803. Proteomics. 2006;6:910–920. doi: 10.1002/pmic.200500114. PubMed DOI

Husseini NS, Alsaied OA, Thorne RE, Berejnov V. Effects of cryoprotectant concentration and cooling rate on vitrification of aqueous solutions. J Appl Crystallogr. 2006;39:244–251. doi: 10.1107/S0021889806004717. DOI

Karr DB, Waters JK, Emerich DW (1983) Analysis of poly-β-hydroxybutyrate in Rhizobium japonicum bacteroids by ion-exclusion high-pressure liquid chromatography and UV detection. Appl Environ Microbiol 46:1339–1344 PubMed PMC

Klähn S, Hagemann M. Compatible solute biosynthesis in cyanobacteria. Environ Microbiol. 2011;13:551–562. doi: 10.1111/j.1462-2920.2010.02366.x. PubMed DOI

Klotz A, Georg J, Bučinská L, Watanabe S, Reimann V, Januszewski W, Sobotka R, Jendrossek D, Hess WR, Forchhammer K. Awakening of a dormant cyanobacterium from nitrogen chlorosis reveals a genetically determined program. Curr Biol. 2016;26:2862–2872. doi: 10.1016/j.cub.2016.08.054. PubMed DOI

Koch M, Bruckmoser J, Scholl J, Hauf W, Rieger B, Forchhammer K (2020) Maximizing PHB content in Synechocystis sp. PCC 6803: a new metabolic engineering strategy based on the regulator PirC. Microb Cell Fact 19:231 PubMed PMC

Koch M, Doello S, Gutekunst K, Forchhammer K (2019) PHB is produced from glycogen turn-over during nitrogen starvation in Synechocystis sp. PCC 6803. Int J Molec Sci 20:1942 PubMed PMC

Koch M, Forchhammer K (2021) Polyhydroxybutyrate: A useful product of chlorotic cyanobacteria. MIP 31:67–77 PubMed

Kouřilová X, Schwarzerová J, Pernicová I, Sedlář K, Mrázová K, Krzyžánek V, Nebesářová J, Obruča S. The first insight into polyhydroxyalkanoates accumulation in multi-extremophilic Rubrobacter xylanophilus and Rubrobacter spartanus. Microorganisms. 2021;5:909. doi: 10.3390/microorganisms9050909. PubMed DOI PMC

Krasikov V, Aguirre von Wobeser E, Dekker HL, Huisman J, Matthijs HC. Time-series resolution of gradual nitrogen starvation and its impact on photosynthesis in the cyanobacterium Synechocystis PCC 6803. Physiol Plant. 2012;145:426–439. doi: 10.1111/j.1399-3054.2012.01585.x. PubMed DOI

Lichtenthaler HK, Wellburn AR. Determinations of total carotenoids and chlorophylls a and b of leaf extracts in different solvents. Biochem Soc Trans. 1983;11:591–592. doi: 10.1042/bst0110591. DOI

Luan G, Zhang S, Wang M, Lu X. Progress and perspective on cyanobacterial glycogen metabolism engineering. Biotechnol Adv. 2019;37:771–786. doi: 10.1016/j.biotechadv.2019.04.005. PubMed DOI

Luimstra VM, Schuurmans JM, de Carvalho CFM, Matthijs HCP, Hellingwerf KJ, Huisman J. Exploring the low photosynthetic efficiency of cyanobacteria in blue light using a mutant lacking phycobilisomes. Photosynth Res. 2019;141:291–301. doi: 10.1007/s11120-019-00630-z. PubMed DOI PMC

MacColl R, Guard-Friar D. Phycobiliproteins. Boca Raton: CRC Press; 2018.

McDonald K (2007) Cryopreparation methods for electron microscopy of selected model systems. Meth Cell Biol 79:23–56 PubMed

McGee M (2021) Earth’s CO2 Home Page. https://www.co2.earth/. Accessed 8 Aug 2021

Mills LA, McCormick AJ, Lea-Smith DJ (2020) Current knowledge and recent advances in understanding metabolism of the model cyanobacterium Synechocystis sp PCC 6803. Biosci Rep 40:BSR20193325 PubMed PMC

Monshupanee T, Incharoensakdi A (2014) Enhanced accumulation of glycogen, lipids and polyhydroxybutyrate under optimal nutrients and light intensities in the cyanobacterium Synechocystis sp. PCC 6803. J Appl Microbiol 116:830–838 PubMed

Obruca S, Sedlacek P, Koller M. The underexplored role of diverse stress factors in microbial biopolymer synthesis. Bioresour Technoly. 2021;326:124767. doi: 10.1016/j.biortech.2021.124767. PubMed DOI

Obruca S, Sedlacek P, Krzyzanek V, Mravec F, Hrubanova K, Samek O, Kucera D, BenesovaMarova P. Accumulation of poly(3-hydroxybutyrate) helps bacterial cells to survive freezing. PLoS One. 2016;6:e0157778. doi: 10.1371/journal.pone.0157778. PubMed DOI PMC

Obruca S, Sedlacek P, Slaninova E, Fritz I, Daffert C, Meixner K, Sedrlova Z, Koller M. Novel unexpected functions of PHA granules. Appl Microbiol Biotechnol. 2020;104:4795–4810. doi: 10.1007/s00253-020-10568-1. PubMed DOI

Pade N, Mikkat S, Hagemann M. Ethanol, glycogen and glucosylglycerol represent competing carbon pools in ethanol-producing cells of Synechocystis sp. PCC 6803 under high-salt conditions. Microbiology. 2017;163:300–307. doi: 10.1099/mic.0.000433. PubMed DOI

Rezayian M, Niknam V, Ebrahimzadeh H. Stress response in cyanobacteria. Iranian J Plant Physiol. 2019;9:2773–2878.

Rippka R, Deruelles J, Waterbury JB, Herdman M, Stanier RY. Generic assignments, strain histories and properties of pure cultures of cyanobacteria. J Gen Microbiol. 1979;111:1–61.

Ritchie RJ. Consistent sets of spectrophotometric chlorophyll equations for acetone, methanol and ethanol solvents. Photosynth Res. 2006;89:27–41. doi: 10.1007/s11120-006-9065-9. PubMed DOI

Rueda E, García-Galán MJ, Díez-Montero R, Vila J, Grifoll M, García J (2020) Polyhydroxybutyrate and glycogen production in photobioreactors inoculated with wastewater borne cyanobacteria monocultures. Bioresour Technol 295:122233 PubMed

Schubert H, Fulda S, Hagemann M. Effects of adaptation to different salt concentrations on photosynthesis and pigmentation of the cyanobacterium Synechocystis sp. PCC 6803. J Plant Physiol. 1993;142:291–295. doi: 10.1016/S0176-1617(11)80425-6. DOI

Stamatakis K, Tsimilli-Michael M, Papageorgiou GC. On the question of the light-harvesting role of β-carotene in photosystem II and photosystem I core complexes. Plant Physiol Biochem. 2014;81:121–127. doi: 10.1016/j.plaphy.2014.01.014. PubMed DOI

Sudhir P, Murthy SDS. Effects of salt stress on basic processes of photosynthesis. Photosynthetica. 2004;42:481–486. doi: 10.1007/S11099-005-0001-6. DOI

Tanniche I, Collakova E, Denbow C, Senger RS (2020) Characterizing metabolic stress-induced phenotypes of Synechocystis PCC6803 with Raman spectroscopy. PeerJ 8:e8535 PubMed PMC

Velmurugan R, Incharoensakdi A. Disruption of polyhydroxybutyrate synthesis redirects carbon flow towards glycogen synthesis in Synechocystis sp. PCC 6803 overexpressing glgC/glgA. Plant Cell Physiol. 2018;59:2020–2029. doi: 10.1093/pcp/pcy121. PubMed DOI

Wu GF, Shen ZY, Wu QY. Modification of carbon partitioning to enhance PHB production in Synechocystis sp. PCC6803. Enzyme Microbial Technol. 2002;30:710–715. doi: 10.1016/S0141-0229(02)00044-3. DOI

Evaluating stress resilience of cyanobacteria through flow cytometry and fluorescent viability assessment

A Comparison of the Effects of Continuous Illumination and Day/Night Regimes on PHB Accumulation in Synechocystis Cells

Urany-Less Low Voltage Transmission Electron Microscopy: A Powerful Tool for Ultrastructural Studying of Cyanobacterial Cells