The histidine kinase Hik33 perceives osmotic stress and cold stress in Synechocystis sp. PCC 6803

2002 ◽  
Vol 46 (4) ◽  
pp. 905-915 ◽  
Author(s):  
Koji Mikami ◽  
Yu Kanesaki ◽  
Iwane Suzuki ◽  
Norio Murata
2005 ◽  
Vol 32 (9) ◽  
pp. 807 ◽  
Author(s):  
Saowarath Jantaro ◽  
Paula Mulo ◽  
Tove Jansén ◽  
Aran Incharoensakdi ◽  
Pirkko Mäenpää

Salinity is considered to be one of the most severe problems in worldwide agricultural production, but the published investigations give contradictory results of the effect of ionic and osmotic stresses on photosynthesis. In the present study, long-term effects of both ionic and osmotic stresses, especially on photosynthesis, were investigated using the moderately halotolerant cyanobacterium Synechocystis sp. PCC 6803. Our results show that the PSII activity and the photosynthetic capacity tolerated NaCl but a high concentration of sorbitol completely inhibited both activities. In line with these results, we show that the amount of the D1 protein of PSII was decreased under severe osmotic stress, whereas the levels of PsaA / B and NdhF3 proteins remained unchanged. However, high concentrations of sorbitol stress led to a drastic decrease of both psbA (encoding D1) and psaA (encoding PsaA) transcripts, suggesting that severe osmotic stress may abolish the tight coordination of transcription and translation normally present in bacteria, at least in the case of the psaA gene. Taken together, our results indicate that the osmotic stress component is more detrimental to photosynthesis than the ionic one and, furthermore, under osmotic stress, the D1 protein appears to be the target of this stress treatment.


2012 ◽  
Vol 194 (24) ◽  
pp. 6828-6836 ◽  
Author(s):  
M. Akai ◽  
K. Onai ◽  
M. Morishita ◽  
H. Mino ◽  
T. Shijuku ◽  
...  

Life ◽  
2015 ◽  
Vol 5 (1) ◽  
pp. 676-699 ◽  
Author(s):  
Jan Červený ◽  
Maria Sinetova ◽  
Tomáš Zavřel ◽  
Dmitry Los

2006 ◽  
Vol 61 (11-12) ◽  
pp. 865-878 ◽  
Author(s):  
Anke Nodop ◽  
Iwane Suzuki ◽  
Aiko Barsch ◽  
Ann-Kristin Schröder ◽  
Karsten Niehaus ◽  
...  

Abstract The hybrid sensory histidine kinase Slr1759 of the cyanobacterium Synechocystis sp. strain PCC 6803 contains multiple sensory domains and a multi-step phosphorelay system. Immuno blot analysis provided evidence that the histidine kinase Slr1759 is associated with the cytoplasmic membrane. The gene slr1759 is part of an operon together with slr1760, encoding a response regulator. A comparative investigation was performed on Synechocystis sp. strain PCC 6803 wild type (WT) and an insertionally inactivated slr1759-mutant (Hik14) which also lacks the transcript for the response regulator Slr1760. The mutant Hik14 grew significantly slower than WT in the early growth phase, when both were inoculated with a low cell density into BG11 medium without additional buffer and when aerated with air enriched with 2% CO2. Since the aeration with CO2-enriched air results in a decrease of the pH value in the medium, the growth experiments indicated that Hik14 is not able to adjust its metabolic activities as rapidly as WT to compensate for a larger decrease of the pH value in the medium. No significant differences in growth between Hik14 and WT were observed when cells were inoculated with a higher cell density in BG11 medium or when the BG11 medium contained 50 mm Epps-NaOH, pH 7.5, to prevent the pH drop. This Hik14 phenotype has so far only been seen under the above defined growth condition. Results of photosynthetic activity measurements as well as Northern blot-, immuno blot-, and metabolite analyses suggest that the two-component system Slr1759/Slr1760 has a function in the coordination of several metabolic activities which is in good agreement with the complex domain structure of Slr1759. The direct targets of this two-component system have so far not been identified.


2020 ◽  
Author(s):  
Wenyang Wu ◽  
Wei Du ◽  
Ruth Perez Gallego ◽  
Klaas J. Hellingwerf ◽  
Aniek D. van der Woude ◽  
...  

Abstract Background Mannitol is a C(6) polyol that is used in the food and medical sector as a sweetener and antioxidant, respectively. The sustainable production of mannitol, especially via the direct conversion of CO 2 by photosynthetic cyanobacteria, has become increasingly appealing. However, previous work aiming to achieve mannitol production in the marine Synechococcus sp. PCC 7002 via heterologous expression of mannitol-1-phosphate-5-dehydrogenase ( mtlD ) and mannitol-1-phosphatase ( m1p , in short: a ‘mannitol cassette’), proved to be genetically unstable. Results Here, we explore the stabilizing effect that mannitol production may have on cells faced with osmotic stress, in the freshwater cyanobacterium Synechocystis sp. PCC 6803. We first validated that mannitol can function as a compatible solute in Synechocystis sp. PCC 6803, and in derivative strains in which the ability to produce one or both of the native compatible solutes was impaired. Wild type Synechocystis , complemented with a mannitol cassette, indeed showed increased salt tolerance, which was even more evident in Synechocystis strains in which the ability to synthesize the endogenous compatible solutes was impaired. Next we tested the genetic stability of all these strains with respect to their mannitol productivity, with and without salt stress, during prolonged turbidostat cultivations. The obtained results show that mannitol production under salt stress conditions in the Synechocystis strain that cannot synthesize its endogenous compatible solutes is remarkably stable, while the control strain completely loses this ability in only 6 days. DNA sequencing results of the control groups that lost the ability to synthesize mannitol revealed that multiple types of mutation occurred in the mtlD gene that can explain the disruption of mannitol production. Conclusions Mannitol production in freshwater Synechocsytis sp. PCC6803 confers it with increased salt tolerance. Under this strategy, genetically instability which was the major challenge for mannitol production in cyanobacteria is tackled. This paper marks the first report of utilization of the response to salt stress as a factor that can increase the stability of mannitol production in a cyanobacterial cell factory.


2020 ◽  
Author(s):  
Wenyang Wu ◽  
Wei Du ◽  
Ruth Perez Gallego ◽  
Klaas J. Hellingwerf ◽  
Aniek D. van der Woude ◽  
...  

Abstract Background Mannitol is a C(6) polyol that is used in the food and medical sector as a sweetener and antioxidant, respectively. The sustainable production of mannitol, especially via the direct conversion of CO 2 by photosynthetic cyanobacteria, has become increasingly appealing. However, previous work aiming to achieve mannitol production in the marine Synechococcus sp. PCC 7002 via heterologous expression of mannitol-1-phosphate-5-dehydrogenase ( mtlD ) and mannitol-1-phosphatase ( m1p , in short: a ‘mannitol cassette’), proved to be genetically unstable. Results Here, we explore the stabilizing effect that mannitol production may have on cells faced with osmotic stress, in the freshwater cyanobacterium Synechocystis sp. PCC 6803. We first validated that mannitol can function as a compatible solute in Synechocystis sp. PCC 6803, and in derivative strains in which the ability to produce one or both of the native compatible solutes was impaired. Wild type Synechocystis , complemented with a mannitol cassette, indeed showed increased salt tolerance, which was even more evident in Synechocystis strains in which the ability to synthesize the endogenous compatible solutes was impaired. Next we tested the genetic stability of all these strains with respect to their mannitol productivity, with and without salt stress, during prolonged turbidostat cultivations. The obtained results show that mannitol production under salt stress conditions in the Synechocystis strain that cannot synthesize its endogenous compatible solutes is remarkably stable, while the control strain completely loses this ability in only 6 days. DNA sequencing results of the control groups that lost the ability to synthesize mannitol revealed that multiple types of mutation occurred in the mtlD gene that can explain the disruption of mannitol production. Conclusions Mannitol production in freshwater Synechocsytis sp. PCC6803 confers it with increased salt tolerance. Under this strategy, genetically instability which was the major challenge for mannitol production in cyanobacteria is tackled. This paper marks the first report of both stable mannitol production directly from CO 2 in cyanobacteria, and of the utilization of the response to salt stress as a factor that can stabilize production in a cyanobacterial cell factory.


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