• Title/Summary/Keyword: synechocystis PCC 6803

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Cyanobacterial bioreporters for detection of heavy metals, herbicide, and antibiotics (중금속, 제초제 및 항생제 검출용 남세균 유래 바이오 리포터)

  • Kim, Soo-Youn;Jeong, Won-Joong;Suh, Kye-Hong;Liu, Jang-Ryol;Park, Youn-Il
    • Journal of Plant Biotechnology
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    • v.35 no.2
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    • pp.141-145
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    • 2008

  • In this study, glucose-inducible intergenic sequences were used to generate bioreporters of the cyanobacterium Synechocystis sp. PCC 6803 that could monitor environmental pollutants. Luciferase genes LuxAB from the marine bacterium Vibrio fischeri under the control of glucose-inducible intergenic seqeucens of eight genes (atpI, ndbA, ctaD1, tkt, pgi, pdh, ppc, and cydA) were successfully expressed in the cyano-bacterial transformants, showing 5-25 fold increases in biolumeniscence upon exposure to glucose. In addition, glucose-inducible cyanobacterial bioreporters were very sensitive to various chemicals such as heavy metals ($Hg^{2+}$, $Cu^{2+}$, $Zn^{2+}$), electron transport inhibitors (DCMU, DBMIB, $CN^-$), and antibiotics (chloramphenicol and rifampicin). These glucose-inducible cyanobacterial bioreporters would be useful to develop biosensors for rapid screening of environmental samples.

  • https://doi.org/10.5010/JPB.2008.35.2.141 인용 PDF KSCI

Inhibition of Polyphosphate Degradation in Synechocystis sp. PCC6803 through Inactivation of the phoU Gene

  • Han-bin Ryu;Mi-Jin Kang;Kyung-Min Choi;Il-Kyu Yang;Seong-Joo Hong;Choul-Gyun Lee
    • Journal of Microbiology and Biotechnology
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    • v.34 no.2
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    • pp.407-414
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    • 2024

  • Phosphorus is an essential but non-renewable nutrient resource critical for agriculture. Luxury phosphorus uptake allows microalgae to synthesize polyphosphate and accumulate phosphorus, but, depending on the strain of algae, polyphosphate may be degraded within 4 hours of accumulation. We studied the recovery of phosphorus from wastewater through luxury uptake by an engineered strain of Synechocystis sp. with inhibited polyphosphate degradation and the effect of this engineered Synechocystis biomass on lettuce growth. First, a strain (∆phoU) lacking the phoU gene, which encodes a negative regulator of environmental phosphate concentrations, was generated to inhibit polyphosphate degradation in cells. Polyphosphate concentrations in the phoU knock-out strain were maintained for 24 h and then decreased slowly. In contrast, polyphosphate concentrations in the wild-type strain increased up to 4 h and then decreased rapidly. In addition, polyphosphate concentration in the phoU knockout strain cultured in semi-permeable membrane bioreactors with artificial wastewater medium was 2.5 times higher than that in the wild type and decreased to only 16% after 48 h. The biomass of lettuce treated with the phoU knockout strain (0.157 mg P/m2) was 38% higher than that of the lettuce treated with the control group. These results indicate that treating lettuce with this microalgal biomass can be beneficial to crop growth. These results suggest that the use of polyphosphate-accumulating microalgae as biofertilizers may alleviate the effects of a diminishing phosphorous supply. These findings can be used as a basis for additional genetic engineering to increase intracellular polyphosphate levels.

  • https://doi.org/10.4014/jmb.2311.11046 인용 PDF

A NOVEL PHOTOHETEROTROPHIC MUTANT FOR psaB GENE OF Synechocystis sp. PCC 6803 GENERATED FROM TARGETED MUTAGENESIS

  • Kim, Soohyun;Kim, Seung-Il;Choi, Jong-Soon;Chung, Young-Ho;Chun, Soon-Bai;Park, Young-Mok
    • Journal of Photoscience
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    • v.3 no.1
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    • pp.23-28
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    • 1996

  • To investigate the structure and function of photosystem I, cartridge mutagenesis technique was used to inactivate the psaB gene of photosystem I. From the screen, many strains which have potential defects in photosystem I were generated. Biochemical analysis revealed that B2, one of the mutant, had a reduced amount of chlorophyll. Electron transfer activitx from photosystem II to photosystem I as oxygen uptake was the rate of 64 % of wild type. Also B2 showed a decreased photosystem I activity when measured by 77 K fluorescence emission spectrum. Particularly, immunodetection analysis showed that the B2 had reduced amount of PsaA/PsaB, but a normal range of PsaC and PsaD. Here we present a photoheterotrophic mutant for psaB gene as a unique model strain for future study of structural/functional relationship and biogenesis of photosystem I.

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