• Title, Summary, Keyword: Synechocystis PCC 6803

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Putrescine Transport in a Cyanobacterium Synechocystis sp. PCC 6803

  • Raksajit, Wuttinun;Maenpaa, Pirkko;Incharoensakdi, Aran
    • BMB Reports
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    • v.39 no.4
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    • pp.394-399
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    • 2006
  • The transport of putrescine into a moderately salt tolerant cyanobacterium Synechocystis sp. PCC 6803 was characterized by measuring the uptake of radioactively-labeled putrescine. Putrescine transport showed saturation kinetics with an apparent $K_m$ of $92{\pm}10\;{\mu}M$ and $V_{max}$ of $0.33{\pm}0.05\;nmol/min/mg$ protein. The transport of putrescine was pH-dependent with highest activity at pH 7.0. Strong inhibition of putrescine transport was caused by spermine and spermidine whereas only slight inhibition was observed by the addition of various amino acids. These results suggest that the transport system in Synechocystis sp. PCC 6803 is highly specific for polyamines. Putrescine transport is energy-dependent as evidenced by the inhibition by various metabolic inhibitors and ionophores. Slow growth was observed in cells grown under salt stress. Addition of low concentration of putrescine could restore growth almost to the level observed in the absence of salt stress. Upshift of the external osmolality generated by either NaCl or sorbitol caused an increased putrescine transport with an optimum 2-fold increase at 20 mosmol/kg. The stimulation of putrescine transport mediated by osmotic upshift was abolished in chloramphenicol-treated cells, suggesting possible involvement of an inducible transport system.

Mosquito Larvicidal Activity of Synechocystis PCC6803 Transformed with the cry11Aa gene to Culex tritaeniorhynchus and Anopheles sinensis (Cry11Aa 유전자로 형질전환된 Synechocystis PCC6803의 작은빨간집모기와 중국얼룩날개모기 유충에 대한 살충효과)

  • 이대원
    • Korean journal of applied entomology
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    • v.43 no.1
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    • pp.35-41
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    • 2004
  • Bacillus thuringiensis produces crystal proteins toxic to medically and agriculturally important pests during sporulation. To improve the activity of insecticidal crystal protein in applying to mosquito larval control, an expression vector, pSyn4D harboring the mosquitocidal cry11Aa gene under control of psbA promoter of Amaranthus hybridus was constructed. This expression vector was transformed into Synechocystis PCC6803 and a transformant, Tr2C was selected with kanamycin. The mosquitocidal cry11Aa gene was stably integrated Into genomic DNA of Tr2C in PCR detection using cry11Aa-specific primers. The transformant expressed 72-kDa Cry11Aa protein and median lethal time (LT$\sub$50/) was approximately 2.1 days for Culex tritaeniorhynchus larvae and 0.7 day for Anopheles sinensis larvae, respectively. These results suggest this transformant can be used for mosquito larval control as a biological control agent.

Biological Fixation of Carbon Dioxide by Synechocystis PCC 6803 (Synechocystis PCC 6803에 의한 이산화탄소의 생물학적 고정화)

  • 김장규;원성호;김남기
    • KSBB Journal
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    • v.13 no.1
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    • pp.101-107
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    • 1998
  • Carbon dioxide is estimated to be responsible for 60% of the global warming effect, and this percentage is tending upward. Studies on removal and fixation of $CO_2$ in the flue gas are recognized as one of the important roles of the future biotechnology. Photobiological systems have considerably higher photosynthetic efficiency than conventional biomass system. The experiment for the photosynthetic fixation of $CO_2$ and the biomass production was performed with various initial cell concentration in a tubular photobioreactor and a bubble column $CO_2$ contactor with a gas sparger of $CO_2$ -enriched air(0.03~20%). Synechocystis PCC 6803 could grow at 10~20% $CO_2$ content under pH control. The highest specific growth rate, 0.0258 $h^{-1}$ , was obtained at 5% $CO_2$-air mixture. The maximum cell production rate, 0.2784 g/L.day, was obtained when the initial cell concentration was 0.45 g/L at 5% $CO_2$ -air mixture. The maximum cell concentration was 2.03 g/L in the tubular photobioreactor when the light intensity was $45.5{\mu}$ $E/m^2$ . s. This system showed 0.482 g $CO_2$ /L . day of the $CO_2$ fixation.

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Photokinesis of Cyanobacterium Synechocystis sp. PCC 6803

  • Chung, Young-Ho;Park, Young-Mok;Moon, Yoon-Jung;Lee, Eun-Mi;Choi, Jong-Soon
    • Journal of Photoscience
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    • v.11 no.3
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    • pp.89-94
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    • 2004
  • Motile cyanobacterium Synechocystis sp. PCC 6803 cells show photomovement with respect to the light stimulus. Under lateral irradiation, Synechocystis displays a phototactic gliding movement toward the light source by a twodimensional random biased walk. Under vertical irradiation, Synechocystis decreased the frequency of mean vectorial gliding speed dependent on the applied fluence rate, whereas the deviation distribution width of the speed increased. This strongly suggests the involvement of photokinesis. Evidence for the cyanobacterial photokinesis was discussed in the previous report (Choi et al., 1999. Photochem. Photobiol. 70, 95-102) demonstrating that the gross scalar speed of vertically irradiating cells increased by about 50% compared with that of dark-adapted cells. In the visible wavelength range, Synechocystis cells showed a maximal photokinetic activity at 420 nm and a second maximal activity at 680 nm. The threshold action spectrum for the photokinesis resembles the absorption spectrum of chlorophyll with major differences in the phototaxis action spectrum at 560 nm and 660 nm. We postulate that the cyanobacterial photokinesis is powered by the energy-generating chlorophyll pigments.

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Multi-component kinetics for the growth of the cyanobacterium Synechocystis sp. PCC6803

  • Kim, Hyun-Woo;Park, Seongjun;Rittmann, Bruce E.
    • Environmental Engineering Research
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    • v.20 no.4
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    • pp.347-355
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    • 2015
  • The growth kinetics of phototrophic microorganisms can be controlled by the light irradiance, the concentration of an inorganic nutrient, or both. A multi-component kinetic model is proposed and tested in novel batch experiments that allow the kinetic parameters for each factor to be estimated independently. For the cyanobacterium Synechocystis sp. PCC6803, the estimated parameters are maximum specific growth rate $({\mu}_{max})=2.8/d$, half-maximum-rate light irradiance $(K_L)=11W/m^2$, half-inhibition-rate light irradiance $(K_{L,I})=39W/m^2$, and half-maximum-rate concentration for inorganic carbon $(K_{S,Ci})=0.5mgC/L$, half-maximum-rate concentration for inorganic nitrogen $(K_{S,Ni})=1.4mgN/L$, and half-maximum-rate concentration for inorganic phosphorus $(K_{S,Pi})=0.06mgP/L$. Compared to other phototrophs having ${\mu}max$ estimates, PCC6803 is a fast-growing r-strategist relying on reaction rate. Its half-maximum-rate and half-inhibition rate values identify the ranges of light irradiance and nutrient concentrations that PCC6803 needs to achieve a high specific growth rate to be a sustainable bioenergy source. To gain the advantages of its high maximum specific growth rate, PCC6803 needs to have moderate light illumination ($7-62W/m^2$ for ${\mu}_{syn}{\geq}1/d$) and relatively high nutrient concentrations: $N_i{\geq}2.3 mgN/L$, $P_i{\geq}0.1mgP/L$, and $C_i{\geq}1.0mgC/L$.

Characterization and Functional Study of PyrR Orthologues from Genome Sequences of Bacteria (세균 게놈 유래성 PyrR Orthologue의 기능 분석)

  • 김사열;조현수;설경조;박승환
    • Microbiology and Biotechnology Letters
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    • v.31 no.2
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    • pp.103-110
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    • 2003
  • The regulation of pyrimidine nucleotide synthesis has been proved to be controlled by a regulatory protein PyrR-mediated attenuation in the Gram-positive bacteria. After several bacterial genome sequencing projects, we have discovered the PyrR orthologues in the databases for Haemophilus influenzae and Synechocystis and sp. PCC6803 genome sequences. To investigate whether these PyrR orthologue proteins regulate pyrimidine nucleotide synthesis as well as the cases of Bacillus, the PyrR regions of each strains were amplified by PCR and cloned with pUC19 or T-vector in Escherichia coli and with a shuttle vector pHPS9 for E. coli and B. subtilis. For the regulation test of the PyrR orthologues, the aspartate-transcarbamylase (ATCase) assay was carried out. From the results of the ATCase assay, it was confirmed that Synechocystis sp. PCC6803 could not restore by pyrimidines to a B. subtilis, PyrR but H. influenzae PyrR could. For Purification of PyrR orthologue proteins, PyrR orthologue genes were cloned into the expression vector (pET14b). Over-expressed product of PyrR orthologue genes was purified and analyzed by the SDS-PACE. The purified PyrR orthologue proteins from H. influenzae and Synechocystis sp. PCC6803 turned out to be molecular mass of 18 kDa and 21 kDa, respectively. The result of uracil phosphoribosyl transferase (UPRTase) assay with purified PyrR orthologue proteins showed that H. influenzae PyrR protein only has UPRTase activity. In addition, we could predict several regulatory mechanisms that PyrR orthologue proteins regulate pyrimidine de novo synthesis in bacteria, through phylogenetic analysis for PyrR orthologue protein sequences.

High Throughput Proteomic Approaches for the Dissection of Light Signal Transduction Pathways in Photosynthetic Cyanobacterium Synechocystis sp.PCC 6803

  • Chung Young-Ho;Park Young Mok
    • Proceedings of the Microbiological Society of Korea Conference
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    • pp.203-205
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    • 2002
  • Light is an environmental signal that regulates photomovement and main energy source of photosynthesis in the cyanobacterium Synechocystis sp. PCC 6803 (Syn6803). Syn6803 is a popular model system for study of plant functional genomics. In this report, we adopted 2D gel based proteomics study to investigate proteins related with the light absorption and photo-protection in Syn6803. More than 700 proteins were detected on the SDS-gels stained with silver nitrate. Several proteins showing different expression level under various light conditions were identified with MALDI-TOF Mass spectrometry. As a comparison, we also conducted ICAT-based proteome study using WT and cphl (cyanobacterial phytochrome 1) mutant. A cphl deletion led to changes in the expression of proteins involved in translation, photosynthesis including photosystem and CO2 fixation, and cellular regulation. We are currently involved in TAP-tagging method to study protein-protein interactions in search for the molecular component involved in the light signal transduction of Syn6803 photomovement.

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A Conserved Structure and Function of the YidC Homologous Protein Slr1471 from Synechocystis sp. PCC 6803

  • GathmannI, Sven;Rupprecht, Eva;Kahmann, Uwe;Schneider, Dirk
    • Journal of Microbiology and Biotechnology
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    • v.18 no.6
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    • pp.1090-1094
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    • 2008
  • In this article, we show that the orf slr1471 from Synechocystis sp. PCC 6803 codes for a functional member of the YidC/Alb3/Oxa1 protein family, and the encoded protein has a transmembrane topology with a common core structure. Using specific antibodies raised against the Synechocystis YidC homologous protein, we further show that the Synechocystis YidC protein appears to be predominantly localized in the cyanobacterial cytoplasmic membrane. The impact of the described findings for synthesis of membrane proteins and for protein sorting within cyanobacterial cells is discussed.

Effects of Some Metabolic Inhibitors on Phototactic Movement in Cyanobacterium Synechosystis sp. PCC 6803 PTX (람세균 Synechocystis sp. PCC 6803 PTX의 주광성 운동에 미치는 몇가지 대사 억제제의 효과)

  • 박영총
    • Journal of Plant Biology
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    • v.38 no.1
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    • pp.87-93
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    • 1995
  • For understanding physiological nature of phototaxis in Synechocystis sp. PCC 6803 PTX(S. 6803 PTX), we examined the effects of some metabolic inhibitors and cation ionophore on the phototactic movement. In the presence of DCMU, which blocks the photosynthetic electron transport just after photosystem II acceptor, there was no inhibitory effect on the phototaxis up to $100\;\mu\textrm{M}$. Instead, the respiratory electron chain inhibitor such as sodium azide dramatically impaired the phototaxis in S. 6803 PTX. These observations indicate that the phototaxis is linked not to photo-phosphorylation, but to respiratory phosphorylation. When the cells were treated with un couplers such as CCCP or DNP, which dissipate the electrochemical gradient of proton($\Delta\mu_{H}+$) across the cytoplasmic membrane, these chemicals did not affect phototaxis. In contrast, when cells were treated with DCCD or NBD which deprive cells of A TP but leave $\Delta\mu_{H}+$ intact across the membrane, the phototactic movement was severly reduced. These results imply that ATP production, not proton motive force, is involved in the phototactic movement in this organism as a driving motive force. The application of specific calcium ionophore A23187 strongly impaired positive phototaxis. Calcium fluxes should be engaged in the sensory trans-duction of phototactic orientation. Finally, when ethionine was supplimented to culture media, the photomovement of this organism was inhibited. This implies that methylation/demethylation mechanism controls the process of phototaxis in S. 6803 PTX like chemotaxis in E. coli and Salmonella typhimurium.murium.

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Enhanced PHB Accumulation in Photosystem- and Respiration-defective Mutants of a Cyanobacterium Synechocystis sp. PCC 6803 (Synechocystis sp. PCC 6803의 에너지 대사 결함 돌연변이 균주에서의 Poly(3-hydroxybutyrate) 축적량 증진)

  • Kim Soo-Youn;Choi Gang Guk;Park Youn Il;Park Young Mok;Yang Young Ki;Rhee Young Ha
    • Korean Journal of Microbiology
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    • v.41 no.1
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    • pp.67-73
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    • 2005
  • Photoautotrophic bacteria are promising candidates for the production of poly(3-hydroxybutyrate) (PHB) since they can address the critical problem of substrate costs. In this study, we isolated 25 Tn5-inserted mutants of the Synechocystis sp. PCC 6803 which showed enhanced PHB accumulation compared to the wild-type strain. After 5-days cultivation under nitrogen-limited mixotrophic conditions, the intracellular levels of PHB content in these mutants reached up to $10-30\%$ of dry cell weight (DCW) comparable to $4\%$ of DCW in the wild-type strain. Using the method of inverse PCR, the affected genes of the mutants were mapped on the completely known genome sequence of Synechocystis sp. PCC 6803. As a result, the increased PHB accumulation in 5 mutants were found to be resulted from defects of genes coding for NADH-ubiquinone oxidoreductase, O-succinylbenzoic-CoA ligase, photosystem II PsbT protein or histidine kinase, which are involved in photosystem in thylakoid inner membrane of the cell. The values of $NAD(P)H/NAD(P)^+$ ratio in the cells of these mutants were much higher than that of the wild-type strain as measured by using pulse-amplitude modulated fluorometer, suggesting that PHB synthesis could be enhanced by increasing the level of cellular NAD(P)H which is a limiting substrate for NADPH-dependent acetoacetyl-CoA reductase. From these results, it is likely that NAD(P)H would be a limiting factor for PHB synthesis in Synechocystis sp. PCC 6803.