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Sample records for cyanobacterium synechocystis pcc6803

  1. Effects of overexpressing photosynthetic carbon flux control enzymes in the cyanobacterium Synechocystis PCC 6803.

    Science.gov (United States)

    Liang, Feiyan; Lindblad, Peter

    2016-11-01

    Synechocystis PCC 6803 is a model unicellular cyanobacterium used in e.g. photosynthesis and CO 2 assimilation research. In the present study we examined the effects of overexpressing Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO), sedoheptulose 1,7-biphosphatase (SBPase), fructose-bisphosphate aldolase (FBA) and transketolase (TK), confirmed carbon flux control enzymes of the Calvin-Bassham-Benson (CBB) cycle in higher plants, in Synechocystis PCC 6803. Overexpressing RuBisCO, SBPase and FBA resulted in increased in vivo oxygen evolution (maximal 115%), growth rate and biomass accumulation (maximal 52%) under 100μmolphotonsm -2 s -1 light condition. Cells overexpressing TK showed a chlorotic phenotype but increased biomass by approximately 42% under 100μmolphotonsm -2 s -1 light condition. Under 15μmolphotonsm -2 s -1 light condition, cells overexpressing TK showed enhanced in vivo oxygen evolution. This study demonstrates increased growth and biomass accumulation when overexpressing selected enzymes of the CBB cycle. RuBisCO, SBPase, FBA and TK are identified as four potential targets to improve growth and subsequently also yield of valuable products from Synechocystis PCC 6803. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  2. Role of the PsbI protein in Photosystem II assembly and repair in the cyanobacterium Synechocystis sp. PCC 6803

    Czech Academy of Sciences Publication Activity Database

    Dobáková, Marika; Tichý, Martin; Komenda, Josef

    2007-01-01

    Roč. 145, - (2007), s. 1681-1691 ISSN 0032-0889 R&D Projects: GA ČR GA206/06/0322 Institutional research plan: CEZ:AV0Z50200510 Keywords : photosystem II * cyanobacterium * synechocystis sp. pcc 6803 Subject RIV: EE - Microbiology, Virology Impact factor: 6.367, year: 2007

  3. Seawater cultivation of freshwater cyanobacterium Synechocystis sp. PCC 6803 drastically alters amino acid composition and glycogen metabolism

    OpenAIRE

    Iijima, Hiroko; Nakaya, Yuka; Kuwahara, Ayuko; Hirai, Masami Yokota; Osanai, Takashi

    2015-01-01

    Water use assessment is important for bioproduction using cyanobacteria. For eco-friendly reasons, seawater should preferably be used for cyanobacteria cultivation instead of freshwater. In this study, we demonstrated that the freshwater unicellular cyanobacterium Synechocystis sp. PCC 6803 could be grown in a medium based on seawater. The Synechocystis wild-type strain grew well in an artificial seawater (ASW) medium supplemented with nitrogen and phosphorus sources. The addition of HEPES bu...

  4. Diurnal Regulation of Cellular Processes in the Cyanobacterium Synechocystis sp. Strain PCC 6803: Insights from Transcriptomic, Fluxomic, and Physiological Analyses.

    Science.gov (United States)

    Saha, Rajib; Liu, Deng; Hoynes-O'Connor, Allison; Liberton, Michelle; Yu, Jingjie; Bhattacharyya-Pakrasi, Maitrayee; Balassy, Andrea; Zhang, Fuzhong; Moon, Tae Seok; Maranas, Costas D; Pakrasi, Himadri B

    2016-05-03

    Synechocystis sp. strain PCC 6803 is the most widely studied model cyanobacterium, with a well-developed omics level knowledgebase. Like the lifestyles of other cyanobacteria, that of Synechocystis PCC 6803 is tuned to diurnal changes in light intensity. In this study, we analyzed the expression patterns of all of the genes of this cyanobacterium over two consecutive diurnal periods. Using stringent criteria, we determined that the transcript levels of nearly 40% of the genes in Synechocystis PCC 6803 show robust diurnal oscillating behavior, with a majority of the transcripts being upregulated during the early light period. Such transcripts corresponded to a wide array of cellular processes, such as light harvesting, photosynthetic light and dark reactions, and central carbon metabolism. In contrast, transcripts of membrane transporters for transition metals involved in the photosynthetic electron transport chain (e.g., iron, manganese, and copper) were significantly upregulated during the late dark period. Thus, the pattern of global gene expression led to the development of two distinct transcriptional networks of coregulated oscillatory genes. These networks help describe how Synechocystis PCC 6803 regulates its metabolism toward the end of the dark period in anticipation of efficient photosynthesis during the early light period. Furthermore, in silico flux prediction of important cellular processes and experimental measurements of cellular ATP, NADP(H), and glycogen levels showed how this diurnal behavior influences its metabolic characteristics. In particular, NADPH/NADP(+) showed a strong correlation with the majority of the genes whose expression peaks in the light. We conclude that this ratio is a key endogenous determinant of the diurnal behavior of this cyanobacterium. Cyanobacteria are photosynthetic microbes that use energy from sunlight and CO2 as feedstock. Certain cyanobacterial strains are amenable to facile genetic manipulation, thus enabling

  5. Diurnal Regulation of Cellular Processes in the Cyanobacterium Synechocystis sp. Strain PCC 6803: Insights from Transcriptomic, Fluxomic, and Physiological Analyses

    Directory of Open Access Journals (Sweden)

    Rajib Saha

    2016-05-01

    Full Text Available Synechocystis sp. strain PCC 6803 is the most widely studied model cyanobacterium, with a well-developed omics level knowledgebase. Like the lifestyles of other cyanobacteria, that of Synechocystis PCC 6803 is tuned to diurnal changes in light intensity. In this study, we analyzed the expression patterns of all of the genes of this cyanobacterium over two consecutive diurnal periods. Using stringent criteria, we determined that the transcript levels of nearly 40% of the genes in Synechocystis PCC 6803 show robust diurnal oscillating behavior, with a majority of the transcripts being upregulated during the early light period. Such transcripts corresponded to a wide array of cellular processes, such as light harvesting, photosynthetic light and dark reactions, and central carbon metabolism. In contrast, transcripts of membrane transporters for transition metals involved in the photosynthetic electron transport chain (e.g., iron, manganese, and copper were significantly upregulated during the late dark period. Thus, the pattern of global gene expression led to the development of two distinct transcriptional networks of coregulated oscillatory genes. These networks help describe how Synechocystis PCC 6803 regulates its metabolism toward the end of the dark period in anticipation of efficient photosynthesis during the early light period. Furthermore, in silico flux prediction of important cellular processes and experimental measurements of cellular ATP, NADP(H, and glycogen levels showed how this diurnal behavior influences its metabolic characteristics. In particular, NADPH/NADP+ showed a strong correlation with the majority of the genes whose expression peaks in the light. We conclude that this ratio is a key endogenous determinant of the diurnal behavior of this cyanobacterium.

  6. Biosafety of biotechnologically important microalgae: intrinsic suicide switch implementation in cyanobacterium Synechocystis sp. PCC 6803

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    Helena Čelešnik

    2016-04-01

    Full Text Available In recent years, photosynthetic autotrophic cyanobacteria have attracted interest for biotechnological applications for sustainable production of valuable metabolites. Although biosafety issues can have a great impact on public acceptance of cyanobacterial biotechnology, biosafety of genetically modified cyanobacteria has remained largely unexplored. We set out to incorporate biocontainment systems in the model cyanobacterium Synechocystis sp. PCC 6803. Plasmid-encoded safeguards were constructed using the nonspecific nuclease NucA from Anabaena combined with different metal-ion inducible promoters. In this manner, conditional lethality was dependent on intracellular DNA degradation for regulated autokilling as well as preclusion of horizontal gene transfer. In cells carrying the suicide switch comprising the nucA gene fused to a variant of the copM promoter, efficient inducible autokilling was elicited. Parallel to nuclease-based safeguards, cyanobacterial toxin/antitoxin (TA modules were examined in biosafety switches. Rewiring of Synechocystis TA pairs ssr1114/slr0664 and slr6101/slr6100 for conditional lethality using metal-ion responsive promoters resulted in reduced growth, rather than cell killing, suggesting cells could cope with elevated toxin levels. Overall, promoter properties and translation efficiency influenced the efficacy of biocontainment systems. Several metal-ion promoters were tested in the context of safeguards, and selected promoters, including a nrsB variant, were characterized by beta-galactosidase reporter assay.

  7. Regulation of the scp Genes in the Cyanobacterium Synechocystis sp. PCC 6803--What is New?

    Science.gov (United States)

    Cheregi, Otilia; Funk, Christiane

    2015-08-12

    In the cyanobacterium Synechocystis sp. PCC 6803 there are five genes encoding small CAB-like (SCP) proteins, which have been shown to be up-regulated under stress. Analyses of the promoter sequences of the scp genes revealed the existence of an NtcA binding motif in two scp genes, scpB and scpE. Binding of NtcA, the key transcriptional regulator during nitrogen stress, to the promoter regions was shown by electrophoretic mobility shift assay. The metabolite 2-oxoglutarate did not increase the affinity of NtcA for binding to the promoters of scpB and scpE. A second motif, the HIP1 palindrome 5' GGCGATCGCC 3', was detected in the upstream regions of scpB and scpC. The transcription factor encoded by sll1130 has been suggested to recognize this motif to regulate heat-responsive genes. Our data suggest that HIP1 is not a regulatory element within the scp genes. Further, the presence of the high light regulatory (HLR1) motif was confirmed in scpB-E, in accordance to their induced transcriptions in cells exposed to high light. The HLR1 motif was newly discovered in eight additional genes.

  8. Advances in the Function and Regulation of Hydrogenase in the Cyanobacterium Synechocystis PCC6803

    Science.gov (United States)

    Cassier-Chauvat, Corinne; Veaudor, Théo; Chauvat, Franck

    2014-01-01

    In order to use cyanobacteria for the biological production of hydrogen, it is important to thoroughly study the function and the regulation of the hydrogen-production machine in order to better understand its role in the global cell metabolism and identify bottlenecks limiting H2 production. Most of the recent advances in our understanding of the bidirectional [Ni-Fe] hydrogenase (Hox) came from investigations performed in the widely-used model cyanobacterium Synechocystis PCC6803 where Hox is the sole enzyme capable of combining electrons with protons to produce H2 under specific conditions. Recent findings suggested that the Hox enzyme can receive electrons from not only NAD(P)H as usually shown, but also, or even preferentially, from ferredoxin. Furthermore, plasmid-encoded functions and glutathionylation (the formation of a mixed-disulfide between the cysteines residues of a protein and the cysteine residue of glutathione) are proposed as possible new players in the function and regulation of hydrogen production. PMID:25365180

  9. Phosphoproteome of the cyanobacterium Synechocystis sp. PCC 6803 and its dynamics during nitrogen starvation.

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    Philipp eSpät

    2015-03-01

    Full Text Available Cyanobacteria have shaped the earth’s biosphere as the first oxygenic photoautotrophs and still play an important role in many ecosystems. The ability to adapt to changing environmental conditions is an essential characteristic in order to ensure survival. To this end, numerous studies have shown that bacteria use protein post-translational modifications such as Ser/Thr/Tyr phosphorylation in cell signalling, adaptation and regulation. Nevertheless, our knowledge of cyanobacterial phosphoproteomes and their dynamic response to environmental stimuli is relatively limited. In this study, we applied gel-free methods and high accuracy mass spectrometry towards the unbiased detection of Ser/Thr/Tyr phosphorylation events in the model cyanobacterium Synechocystis sp. PCC 6803. We could identify over 300 phosphorylation events in cultures grown on nitrate as exclusive nitrogen source. Chemical dimethylation labelling was applied to investigate proteome and phosphoproteome dynamics during nitrogen starvation. Our dataset describes the most comprehensive (phosphoproteome of Synechocystis to date, identifying 2,382 proteins and 183 phosphorylation events and quantifying 2,111 proteins and 148 phosphorylation events during nitrogen starvation. Global protein phosphorylation levels were increased in response to nitrogen depletion after 24 hours. Among the proteins with increased phosphorylation, the PII signalling protein showed the highest fold-change, serving as positive control. Other proteins with increased phosphorylation levels comprised functions in photosynthesis and in carbon and nitrogen metabolism. This study reveals dynamics of Synechocystis phosphoproteome in response to environmental stimuli and suggests an important role of protein Ser/Thr/Tyr phosphorylation in fundamental mechanisms of homeostatic control in cyanobacteria.

  10. Global transcriptional profiles of the copper responses in the cyanobacterium Synechocystis sp. PCC 6803.

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    Joaquin Giner-Lamia

    Full Text Available Copper is an essential element involved in fundamental processes like respiration and photosynthesis. However, it becomes toxic at high concentration, which has forced organisms to control its cellular concentration. We have recently described a copper resistance system in the cyanobacterium Synechocystis sp. PCC 6803, which is mediated by the two-component system, CopRS, a RND metal transport system, CopBAC and a protein of unknown function, CopM. Here, we report the transcriptional responses to copper additions at non-toxic (0.3 µM and toxic concentrations (3 µM in the wild type and in the copper sensitive copR mutant strain. While 0.3 µM copper slightly stimulated metabolism and promoted the exchange between cytochrome c6 and plastocyanin as soluble electron carriers, the addition of 3 µM copper catalyzed the formation of ROS, led to a general stress response and induced expression of Fe-S cluster biogenesis genes. According to this, a double mutant strain copRsufR, which expresses constitutively the sufBCDS operon, tolerated higher copper concentration than the copR mutant strain, suggesting that Fe-S clusters are direct targets of copper toxicity in Synechocystis. In addition we have also demonstrated that InrS, a nickel binding transcriptional repressor that belong to the CsoR family of transcriptional factor, was involved in heavy metal homeostasis, including copper, in Synechocystis. Finally, global gene expression analysis of the copR mutant strain suggested that CopRS only controls the expression of copMRS and copBAC operons in response to copper.

  11. Stable transformation of the cyanobacterium Synechocystis sp. PCC 6803 induced by UV irradiation

    International Nuclear Information System (INIS)

    Dzelzkalns, V.A.; Bogorad, L.

    1986-01-01

    Irradiation of the photoheterotrophic cyanobacterium Synechocystis sp. PCC 6803 with low levels of UV light allows for stable, integrative transformation of these cells by heterologous DNA. In this system, transformation does not rely on an autonomously replicating plasmid and is independent of homologous recombination. Cells treated with UV light in the absence of DNA and cells given DNA but not exposed to UV do not yield antibiotic-resistant colonies in platings of up to 2 x 10 8 cells. Optimal conditions for this UV-induced transformation are described. Analysis of the transformants indicates that (i) only a segment of the introduced plasmid is found in the DNA of the transformed cells; (ii) in independently isolated clones, DNA insertion apparently occurs at different sites in the chromosome; and (iii) hybridization data suggest that insertion in one of the transformants may have occurred into a region of the chromosome that is repeated or that integration of plasmid DNA may have been accompanied by a rearrangement or duplication of DNA sequences near the insertion site. DNA isolated from the primary transformants as well as a cloned fragment containing the UV- inserted plasmid sequence and flanking cyanobacterial DNA transform wild-type cells at a high frequency (5.0 x 10 -4 and 1.5 x 10 -5 , respectively). Possible mechanisms of this transformation system are discussed, as are the potential uses of this system as an integrative cloning-complementation vector and as a mutagenic agent in which the genetic lesion is already tagged with a selectable marker

  12. The PsaE subunit of photosystem I prevents light-induced formation of reduced oxygen species in the cyanobacterium Synechocystis sp. PCC 6803

    NARCIS (Netherlands)

    Jeanjean, R.; Latifi, A.; Matthijs, H.C.P.; Havaux, M.

    2008-01-01

    The PsaE protein is located at the reducing side of photosystem I (PSI) and is involved in docking the soluble electron acceptors, particularly ferredoxin. However, deletion of the psaE gene in the cyanobacterium Synechocystis sp. strain PCC 6803 inhibited neither photoautotrophic growth, nor in

  13. An integrative approach to energy, carbon, and redox metabolism in the cyanobacterium Synechocystis sp. PCC 6803

    Energy Technology Data Exchange (ETDEWEB)

    Overbeek, Ross; Fonstein, Veronika; Osterman, Andrei; Gerdes, Svetlana; Vassieva, Olga; Zagnitko, Olga; Rodionov, Dmitry

    2005-02-15

    The team of the Fellowship for Interpretation of Genomes (FIG) under the leadership of Ross Overbeek, began working on this Project in November 2003. During the previous year, the Project was performed at Integrated Genomics Inc. A transition from the industrial environment to the public domain prompted us to adjust some aspects of the Project. Notwithstanding the challenges, we believe that these adjustments had a strong positive impact on our deliverables. Most importantly, the work of the research team led by R. Overbeek resulted in the deployment of a new open source genomic platform, the SEED (Specific Aim 1). This platform provided a foundation for the development of CyanoSEED a specialized portal to comparative analysis and metabolic reconstruction of all available cyanobacterial genomes (Specific Aim 3). The SEED represents a new generation of software for genome analysis. Briefly, it is a portable and extendable system, containing one of the largest and permanently growing collections of complete and partial genomes. The complete system with annotations and tools is freely available via browsing or via installation on a user's Mac or Linux computer. One of the important unique features of the SEED is the support of metabolic reconstruction and comparative genome analysis via encoding and projection of functional subsystems. During the project period, the FIG research team has validated the new software by developing a significant number of core subsystems, covering many aspects of central metabolism (Specific Aim 2), as well as metabolic areas specific for cyanobacteria and other photoautotrophic organisms (Specific Aim 3). In addition to providing a proof of technology and a starting point for further community-based efforts, these subsystems represent a valuable asset. An extensive coverage of central metabolism provides the bulk of information required for metabolic modeling in Synechocystis sp.PCC 6803. Detailed analysis of several subsystems

  14. Alcohol dehydrogenase AdhA plays a role in ethanol tolerance in model cyanobacterium Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Vidal, Rebeca

    2017-04-01

    The protein AdhA from the cyanobacterium Synechocystis sp. PCC 6803 (hereafter Synechocystis) has been previously reported to show alcohol dehydrogenase activity towards ethanol and both NAD and NADP. This protein is currently being used in genetically modified strains of Synechocystis capable of synthesizing ethanol showing the highest ethanol productivities. In the present work, mutant strains of Synechocystis lacking AdhA have been constructed and tested for tolerance to ethanol. The lack of AdhA in the wild-type strain reduces survival to externally added ethanol at lethal concentration of 4% (v/v). On the other hand, the lack of AdhA in an ethanologenic strain diminishes tolerance of cells to internally produced ethanol. It is also shown that light-activated heterotrophic growth (LAHG) of the wild-type strain is impaired in the mutant strain lacking AdhA (∆adhA strain). Photoautotrophic, mixotrophic, and photoheterotrophic growth are not affected in the mutant strain. Based on phenotypic characterization of ∆adhA mutants, the possible physiological function of AdhA in Synechocystis is discussed.

  15. Identification of a transporter Slr0982 involved in ethanol tolerance in cyanobacterium Synechocystis sp. PCC 6803

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    Yanan eZhang

    2015-05-01

    Full Text Available Cyanobacteria have been engineered to produce ethanol through recent synthetic biology efforts. However, one major challenge to the cyanobacterial systems for high-efficiency ethanol production is their low tolerance to the ethanol toxicity. With a major goal to identify novel transporters involved in ethanol tolerance, we constructed gene knockout mutants for 58 transporter-encoding genes of Synechocystis sp. PCC 6803 and screened their tolerance change under ethanol stress. The efforts allowed discovery of a mutant of slr0982 gene encoding an ATP-binding cassette transporter which grew poorly in BG11 medium supplemented with 1.5% (v/v ethanol when compared with the wild type, and the growth loss could be recovered by complementing slr0982 in the ∆slr0982 mutant, suggesting that slr0982 is involved in ethanol tolerance in Synechocystis. To decipher the tolerance mechanism involved, a comparative metabolomic and network-based analysis of the wild type and the ethanol-sensitive ∆slr0982 mutant was performed. The analysis allowed the identification of four metabolic modules related to slr0982 deletion in the ∆slr0982 mutant, among which metabolites like sucrose and L-pyroglutamic acid which might be involved in ethanol tolerance, were found important for slr0982 deletion in the ∆slr0982 mutant. This study reports on the first transporter related to ethanol tolerance in Synechocystis, which could be a useful target for further tolerance engineering. In addition, metabolomic and network analysis provides important findings for better understanding of the tolerance mechanism to ethanol stress in Synechocystis.

  16. Transcriptomic response to prolonged ethanol production in the cyanobacterium Synechocystis sp. PCC6803.

    Science.gov (United States)

    Dienst, Dennis; Georg, Jens; Abts, Thomas; Jakorew, Lew; Kuchmina, Ekaterina; Börner, Thomas; Wilde, Annegret; Dühring, Ulf; Enke, Heike; Hess, Wolfgang R

    2014-02-06

    The production of biofuels in photosynthetic microalgae and cyanobacteria is a promising alternative to the generation of fuels from fossil resources. To be economically competitive, producer strains need to be established that synthesize the targeted product at high yield and over a long time. Engineering cyanobacteria into forced fuel producers should considerably interfere with overall cell homeostasis, which in turn might counteract productivity and sustainability of the process. Therefore, in-depth characterization of the cellular response upon long-term production is of high interest for the targeted improvement of a desired strain. The transcriptome-wide response to continuous ethanol production was examined in Synechocystis sp. PCC6803 using high resolution microarrays. In two independent experiments, ethanol production rates of 0.0338% (v/v) ethanol d-1 and 0.0303% (v/v) ethanol d-1 were obtained over 18 consecutive days, measuring two sets of biological triplicates in fully automated photobioreactors. Ethanol production caused a significant (~40%) delay in biomass accumulation, the development of a bleaching phenotype and a down-regulation of light harvesting capacity. However, microarray analyses performed at day 4, 7, 11 and 18 of the experiment revealed only three mRNAs with a strongly modified accumulation level throughout the course of the experiment. In addition to the overexpressed adhA (slr1192) gene, this was an approximately 4 fold reduction in cpcB (sll1577) and 3 to 6 fold increase in rps8 (sll1809) mRNA levels. Much weaker modifications of expression level or modifications restricted to day 18 of the experiment were observed for genes involved in carbon assimilation (Ribulose bisphosphate carboxylase and Glutamate decarboxylase). Molecular analysis of the reduced cpcB levels revealed a post-transcriptional processing of the cpcBA operon mRNA leaving a truncated mRNA cpcA* likely not competent for translation. Moreover, western blots and zinc

  17. Characterization of three bioenergetically active respiratory terminal oxidases in the cyanobacterium Synechocystis sp. strain PCC 6803.

    Science.gov (United States)

    Pils, D; Schmetterer, G

    2001-09-25

    Synechocystis sp. PCC 6803 contains three respiratory terminal oxidases (RTOs): cytochrome c oxidase (Cox), quinol oxidase (Cyd), and alternate RTO (ARTO). Mutants lacking combinations of the RTOs were used to characterize these key enzymes of respiration. Pentachlorophenol and 2-heptyl-4-hydroxy-quinoline-N-oxide inhibited Cyd completely, but had little effect on electron transport to the other RTOs. KCN inhibited all three RTOs but the in vivo K(I) for Cox and Cyd was quite different (7 vs. 27 microM), as was their affinity for oxygen (K(M) 1.0 vs. 0.35 microM). ARTO has a very low respiratory activity. However, when uptake of 3-O-methylglucose, an active H+ co-transport, was used to monitor energization of the cytoplasmic membrane, ARTO was similarly effective as the other RTOs. As removal of the gene for cytochrome c(553) had the same effects as removal of ARTO genes, we propose that the ARTO might be a second Cox. The possible functions, localization and regulation of the RTOs are discussed.

  18. Genomic responses to arsenic in the cyanobacterium Synechocystis sp. PCC 6803.

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    Ana María Sánchez-Riego

    Full Text Available Arsenic is a ubiquitous contaminant and a toxic metalloid which presents two main redox states in nature: arsenite [As(III] and arsenate [As(V]. Arsenic resistance in Synechocystis sp. strain PCC 6803 is mediated by the arsBHC operon and two additional arsenate reductases encoded by the arsI1 and arsI2 genes. Here we describe the genome-wide responses to the presence of arsenate and arsenite in wild type and mutants in the arsenic resistance system. Both forms of arsenic produced similar responses in the wild type strain, including induction of several stress related genes and repression of energy generation processes. These responses were transient in the wild type strain but maintained in time in an arsB mutant strain, which lacks the arsenite transporter. In contrast, the responses observed in a strain lacking all arsenate reductases were somewhat different and included lower induction of genes involved in metal homeostasis and Fe-S cluster biogenesis, suggesting that these two processes are targeted by arsenite in the wild type strain. Finally, analysis of the arsR mutant strain revealed that ArsR seems to only control 5 genes in the genome. Furthermore, the arsR mutant strain exhibited hypersentivity to nickel, copper and cadmium and this phenotype was suppressed by mutation in arsB but not in arsC gene suggesting that overexpression of arsB is detrimental in the presence of these metals in the media.

  19. Function and Regulation of Ferredoxins in the Cyanobacterium, Synechocystis PCC6803: Recent Advances.

    Science.gov (United States)

    Cassier-Chauvat, Corinne; Chauvat, Franck

    2014-11-07

    Ferredoxins (Fed), occurring in most organisms, are small proteins that use their iron-sulfur cluster to distribute electrons to various metabolic pathways, likely including hydrogen production. Here, we summarize the current knowledge on ferredoxins in cyanobacteria, the prokaryotes regarded as important producers of the oxygenic atmosphere and biomass for the food chain, as well as promising cell factories for biofuel production. Most studies of ferredoxins were performed in the model strain, Synechocystis PCC6803, which possesses nine highly-conserved ferredoxins encoded by monocistronic or operonic genes, some of which are localized in conserved genome regions. Fed1, encoded by a light-inducible gene, is a highly abundant protein essential to photosynthesis. Fed2-Fed9, encoded by genes differently regulated by trophic conditions, are low-abundant proteins that play prominent roles in the tolerance to environmental stresses. Concerning the selectivity/redundancy of ferredoxin, we report that Fed1, Fed7 and Fed9 belong to ferredoxin-glutaredoxin-thioredoxin crosstalk pathways operating in the protection against oxidative and metal stresses. Furthermore, Fed7 specifically interacts with a DnaJ-like protein, an interaction that has been conserved in photosynthetic eukaryotes in the form of a composite protein comprising DnaJ- and Fed7-like domains. Fed9 specifically interacts with the Flv3 flavodiiron protein acting in the photoreduction of O2 to H2O.

  20. Function and Regulation of Ferredoxins in the Cyanobacterium, Synechocystis PCC6803: Recent Advances

    Directory of Open Access Journals (Sweden)

    Corinne Cassier-Chauvat

    2014-11-01

    Full Text Available Ferredoxins (Fed, occurring in most organisms, are small proteins that use their iron-sulfur cluster to distribute electrons to various metabolic pathways, likely including hydrogen production. Here, we summarize the current knowledge on ferredoxins in cyanobacteria, the prokaryotes regarded as important producers of the oxygenic atmosphere and biomass for the food chain, as well as promising cell factories for biofuel production. Most studies of ferredoxins were performed in the model strain, Synechocystis PCC6803, which possesses nine highly-conserved ferredoxins encoded by monocistronic or operonic genes, some of which are localized in conserved genome regions. Fed1, encoded by a light-inducible gene, is a highly abundant protein essential to photosynthesis. Fed2-Fed9, encoded by genes differently regulated by trophic conditions, are low-abundant proteins that play prominent roles in the tolerance to environmental stresses. Concerning the selectivity/redundancy of ferredoxin, we report that Fed1, Fed7 and Fed9 belong to ferredoxin-glutaredoxin-thioredoxin crosstalk pathways operating in the protection against oxidative and metal stresses. Furthermore, Fed7 specifically interacts with a DnaJ-like protein, an interaction that has been conserved in photosynthetic eukaryotes in the form of a composite protein comprising DnaJ- and Fed7-like domains. Fed9 specifically interacts with the Flv3 flavodiiron protein acting in the photoreduction of O2 to H2O.

  1. Seawater cultivation of freshwater cyanobacterium Synechocystis sp. PCC 6803 drastically alters amino acid composition and glycogen metabolism

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    Hiroko eIijima

    2015-04-01

    Full Text Available Water use assessment is important for bioproduction using cyanobacteria. For eco-friendly reasons, seawater should preferably be used for cyanobacteria cultivation instead of freshwater. In this study, we demonstrated that the freshwater unicellular cyanobacterium Synechocystis sp. PCC 6803 could be grown in a medium based on seawater. The Synechocystis wild-type strain grew well in an artificial seawater (ASW medium supplemented with nitrogen and phosphorus sources. The addition of HEPES buffer improved cell growth overall, although the growth in ASW medium was inferior to that in the synthetic BG-11 medium. The levels of proteins involved in sugar metabolism changed depending on the culture conditions. The biosynthesis of several amino acids including aspartate, glutamine, glycine, proline, ornithine, and lysine, was highly up-regulated by cultivation in ASW. Two types of natural seawater (NSW were also made available for the cultivation of Synechocystis cells, with supplementation of both nitrogen and phosphorus sources. These results revealed the potential use of seawater for the cultivation of freshwater cyanobacteria, which would help to reduce freshwater consumption during biorefinery using cyanobacteria.

  2. Distinguishing the Roles of Thylakoid Respiratory Terminal Oxidases in the Cyanobacterium Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Ermakova, Maria; Huokko, Tuomas; Richaud, Pierre; Bersanini, Luca; Howe, Christopher J; Lea-Smith, David J; Peltier, Gilles; Allahverdiyeva, Yagut

    2016-06-01

    Various oxygen-utilizing electron sinks, including the soluble flavodiiron proteins (Flv1/3), and the membrane-localized respiratory terminal oxidases (RTOs), cytochrome c oxidase (Cox) and cytochrome bd quinol oxidase (Cyd), are present in the photosynthetic electron transfer chain of Synechocystis sp. PCC 6803. However, the role of individual RTOs and their relative importance compared with other electron sinks are poorly understood, particularly under light. Via membrane inlet mass spectrometry gas exchange, chlorophyll a fluorescence, P700 analysis, and inhibitor treatment of the wild type and various mutants deficient in RTOs, Flv1/3, and photosystem I, we investigated the contribution of these complexes to the alleviation of excess electrons in the photosynthetic chain. To our knowledge, for the first time, we demonstrated the activity of Cyd in oxygen uptake under light, although it was detected only upon inhibition of electron transfer at the cytochrome b6f site and in ∆flv1/3 under fluctuating light conditions, where linear electron transfer was drastically inhibited due to impaired photosystem I activity. Cox is mostly responsible for dark respiration and competes with P700 for electrons under high light. Only the ∆cox/cyd double mutant, but not single mutants, demonstrated a highly reduced plastoquinone pool in darkness and impaired gross oxygen evolution under light, indicating that thylakoid-based RTOs are able to compensate partially for each other. Thus, both electron sinks contribute to the alleviation of excess electrons under illumination: RTOs continue to function under light, operating on slower time ranges and on a limited scale, whereas Flv1/3 responds rapidly as a light-induced component and has greater capacity. © 2016 American Society of Plant Biologists. All Rights Reserved.

  3. RNA-seq profiling reveals novel target genes of LexA in the cyanobacterium Synechocystis sp. PCC 6803

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    Ayumi eKizawa

    2016-02-01

    Full Text Available LexA is a well-established transcriptional repressor of SOS genes induced by DNA damage in E. coli and other bacterial species. However, LexA in the cyanobacterium Synechocystis sp. PCC 6803 has been suggested not to be involved in SOS response. In this study, we performed RNA-seq analysis of the wild-type strain and the lexA-disrupted mutant to obtain the comprehensive view of LexA-regulated genes in Synechocystis. Disruption of lexA positively or negatively affected expression of genes related to various cellular functions such as phototactic motility, accumulation of the major compatible solute glucosylglycerol and subunits of bidirectional hydrogenase, photosystem I and phycobilisome complexes. We also observed increase in the expression level of genes related to iron and manganese uptake in the mutant at the later stage of cultivation. However, none of the genes related to DNA metabolism were affected by disruption of lexA. DNA gel mobility shift assay using the recombinant LexA protein suggested that LexA binds to the upstream region of pilA7, pilA9, ggpS and slr1670 to directly regulate their expression, but changes in the expression level of photosystem I genes by disruption of lexA is likely a secondary effect.

  4. Metabolic engineering of the pentose phosphate pathway for enhanced limonene production in the cyanobacterium Synechocysti s sp. PCC 6803.

    Science.gov (United States)

    Lin, Po-Cheng; Saha, Rajib; Zhang, Fuzhong; Pakrasi, Himadri B

    2017-12-13

    Isoprenoids are diverse natural compounds, which have various applications as pharmaceuticals, fragrances, and solvents. The low yield of isoprenoids in plants makes them difficult for cost-effective production, and chemical synthesis of complex isoprenoids is impractical. Microbial production of isoprenoids has been considered as a promising approach to increase the yield. In this study, we engineered the model cyanobacterium Synechocystis sp. PCC 6803 for sustainable production of a commercially valuable isoprenoid, limonene. Limonene synthases from the plants Mentha spicata and Citrus limon were expressed in cyanobacteria for limonene production. Production of limonene was two-fold higher with limonene synthase from M. spicata than that from C. limon. To enhance isoprenoid production, computational strain design was conducted by applying the OptForce strain design algorithm on Synechocystis 6803. Based on the metabolic interventions suggested by this algorithm, genes (ribose 5-phosphate isomerase and ribulose 5-phosphate 3-epimerase) in the pentose phosphate pathway were overexpressed, and a geranyl diphosphate synthase from the plant Abies grandis was expressed to optimize the limonene biosynthetic pathway. The optimized strain produced 6.7 mg/L of limonene, a 2.3-fold improvement in productivity. Thus, this study presents a feasible strategy to engineer cyanobacteria for photosynthetic production of isoprenoids.

  5. Construction of a stepwise gene integration system by transient expression of actinophage R4 integrase in cyanobacterium Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Miura, Takamasa; Nishizawa, Akito; Nishizawa, Tomoyasu; Asayama, Munehiko; Takahashi, Hideo; Shirai, Makoto

    2014-08-01

    The integrase of actinophage R4, which belongs to the large serine-recombinase family, catalyzes site-specific recombination between two distinct attachment site sequences of the phage (attP) and actinomycete Streptomyces parvulus 2297 chromosome (attB). We previously reported that R4 integrase (Sre) catalyzed site-specific recombination both in vivo and in vitro. In the present study, a Sre-based system was developed for the stepwise site-specific integration of multiple genes into the chromosome of cyanobacterium Synechocystis sp. PCC 6803 (hereafter PCC 6803). A transgene-integrated plasmid with two attP sites and a non-replicative sre-containing plasmid were co-introduced into attB-inserted PCC 6803 cells. The transiently expressed Sre catalyzed highly efficient site-specific integration between one of the two attP sites on the integration plasmid and the attB site on the chromosome of PCC 6803. A second transgene-integrated plasmid with an attB site was integrated into the residual attP site on the chromosome by repeating site-specific recombination. The transformation frequencies (%) of the first and second integrations were approximately 5.1 × 10(-5) and 8.2 × 10(-5), respectively. Furthermore, the expression of two transgenes was detected. This study is the first to apply the multiple gene site-specific integration system based on R4 integrase to cyanobacteria.

  6. Glutaredoxins are essential for stress adaptation in the cyanobacterium Synechocystis sp. PCC 6803.

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    Ana M Sánchez-Riego

    2013-11-01

    Full Text Available Glutaredoxin are small redox proteins able to reduce disulfides and mixed disulfides between GSH and proteins. Synechocystis sp. PCC 6803 contains three genes coding for glutaredoxins: ssr2061 (grxA and slr1562 (grxB code for dithiolic glutaredoxins while slr1846 (grxC codes for a monothiolic glutaredoxin. We have analyzed the expression of these glutaredoxins in response to different stresses, such as high light, H2O2 and heat shock. Analysis of the mRNA levels showed that grxA is only induced by heat while grxC is repressed by heat shock and is induced by high light and H2O2. In contrast, grxB expression was maintained almost constant under all conditions. Analysis of GrxA and GrxC protein levels by western blot showed that GrxA increases in response to high light, heat or H2O2 while GrxC is only induced by high light and H2O2, in accordance with its mRNA levels. In addition, we have also generated mutants that have interrupted one, two or three glutaredoxin genes. These mutants were viable and did not show any different phenotype from the WT under standard growth conditions. Nevertheless, analysis of these mutants under several stress conditions revealed that single grxA mutants grow slower after H2O2, heat and high light treatments, while mutants in grxB are indistinguishable from WT. grxC mutants were hypersensitive to treatments with H2O2, heat, high light and metals. A double grxAgrxC mutant was found to be even more sensitive to H2O2 than each corresponding single mutants. Surprisingly a mutation in grxB suppressed totally or partially the phenotypes of grxA and grxC mutants except the H2O2 sensitivity of the grxC mutant. This suggests that grxA and grxC participate in independent pathways while grxA and grxB participate in a common pathway for H2O2 resistance. The data presented here show that glutaredoxins are essential for stress adaptation in cyanobacteria, although their targets and mechanism of action remain unidentified.

  7. Regulation of the scp Genes in the Cyanobacterium Synechocystis sp. PCC 6803—What is New?

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    Otilia Cheregi

    2015-08-01

    Full Text Available In the cyanobacterium Synechocystis sp. PCC 6803 there are five genes encoding small CAB-like (SCP proteins, which have been shown to be up-regulated under stress. Analyses of the promoter sequences of the scp genes revealed the existence of an NtcA binding motif in two scp genes, scpB and scpE. Binding of NtcA, the key transcriptional regulator during nitrogen stress, to the promoter regions was shown by electrophoretic mobility shift assay. The metabolite 2-oxoglutarate did not increase the affinity of NtcA for binding to the promoters of scpB and scpE. A second motif, the HIP1 palindrome 5ʹ GGCGATCGCC 3ʹ, was detected in the upstream regions of scpB and scpC. The transcription factor encoded by sll1130 has been suggested to recognize this motif to regulate heat-responsive genes. Our data suggest that HIP1 is not a regulatory element within the scp genes. Further, the presence of the high light regulatory (HLR1 motif was confirmed in scpB-E, in accordance to their induced transcriptions in cells exposed to high light. The HLR1 motif was newly discovered in eight additional genes.

  8. Biosynthesis of platform chemical 3-hydroxypropionic acid (3-HP) directly from CO2 in cyanobacterium Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Wang, Yunpeng; Sun, Tao; Gao, Xingyan; Shi, Mengliang; Wu, Lina; Chen, Lei; Zhang, Weiwen

    2016-03-01

    3-hydroxypropionic acid (3-HP) is an important platform chemical with a wide range of applications. So far large-scale production of 3-HP has been mainly through petroleum-based chemical processes, whose sustainability and environmental issues have attracted widespread attention. With the ability to fix CO2 directly, cyanobacteria have been engineered as an autotrophic microbial cell factory to produce fuels and chemicals. In this study, we constructed the biosynthetic pathway of 3-HP in cyanobacterium Synechocystis sp. PCC 6803, and then optimized the system through the following approaches: i) increasing expression of malonyl-CoA reductase (MCR) gene using different promoters and cultivation conditions; ii) enhancing supply of the precursor malonyl-CoA by overexpressing acetyl-CoA carboxylase and biotinilase; iii) improving NADPH supply by overexpressing the NAD(P) transhydrogenase gene; iv) directing more carbon flux into 3-HP by inactivating the competing pathways of PHA and acetate biosynthesis. Together, the efforts led to a production of 837.18 mg L(-1) (348.8 mg/g dry cell weight) 3-HP directly from CO2 in Synechocystis after 6 days cultivation, demonstrating the feasibility photosynthetic production of 3-HP directly from sunlight and CO2 in cyanobacteria. In addition, the results showed that overexpression of the ribulose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco) gene from Anabaena sp. PCC 7120 and Synechococcus sp. PCC 7942 led to no increase of 3-HP production, suggesting CO2 fixation may not be a rate-limiting step for 3-HP biosynthesis in Synechocystis. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  9. An Integrative Approach to Energy, Carbon, and Redox Metabolism in the Cyanobacterium Synechocystis sp. PCC 6803. Special Report

    Energy Technology Data Exchange (ETDEWEB)

    Overbeek, R.

    2003-06-30

    The main objectives for the first year were to produce a detailed metabolic reconstruction of synechocystis sp. PCC 6803 especially in interrelated areas of photosynthesis, respiration, and central carbon metabolism to support a more complete understanding and modeling of this organism. Additionally, Integrated Genomics, Inc., provided detailed bioinformatic analysis of selected functional systems related to carbon and energy generation and utilization, and of the corresponding pathways, functional roles and individual genes to support wet lab experiments by collaborators.

  10. The LexA transcription factor regulates fatty acid biosynthetic genes in the cyanobacterium Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Kizawa, Ayumi; Kawahara, Akihito; Takashima, Kosuke; Takimura, Yasushi; Nishiyama, Yoshitaka; Hihara, Yukako

    2017-10-01

    Specific transcription factors have been identified in various heterotrophic bacterial species that regulate the sets of genes required for fatty acid metabolism. Here, we report that expression of the fab genes, encoding fatty acid biosynthetic enzymes, is regulated by the global regulator LexA in the photoautotrophic cyanobacterium Synechocystis sp. PCC 6803. Sll1626, an ortholog of the well-known LexA repressor involved in the SOS response in heterotrophic bacteria, was isolated from crude extracts of Synechocystis by DNA affinity chromatography, reflecting its binding to the upstream region of the acpP-fabF and fabI genes. An electrophoresis mobility shift assay revealed that the recombinant LexA protein can bind to the upstream region of each fab gene tested (fabD, fabH, fabF, fabG, fabZ and fabI). Quantitative RT-PCR analysis of the wild type and a lexA-disrupted mutant strain suggested that LexA acts as a repressor of the fab genes involved in initiation of fatty acid biosynthesis (fabD, fabH and fabF) and the first reductive step in the subsequent elongation cycle (fabG) under normal growth conditions. Under nitrogen-depleted conditions, downregulation of fab gene expression is partly achieved through an increase in LexA-repressing activity. In contrast, under phosphate-depleted conditions, fab gene expression is upregulated, probably due to the loss of repression by LexA. We further demonstrate that elimination of LexA largely increases the production of fatty acids in strains modified to secrete free fatty acids. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  11. Engineered xylose utilization enhances bio-products productivity in the cyanobacterium Synechocystis sp. PCC 6803

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Tai-Chi; Xiong, Wei; Paddock, Troy; Carrieri, Damian; Chang, Ing-Feng; Chiu, Hui-Fen; Ungerer, Justin; Hank Juo, Suh-Hang; Maness, Pin-Ching; Yu, Jianping

    2015-06-12

    Hydrolysis of plant biomass generates a mixture of simple sugars that is particularly rich in glucose and xylose. Fermentation of the released sugars emits CO2 as byproduct due to metabolic inefficiencies. Therefore, the ability of a microbe to simultaneously convert biomass sugars and photosynthetically fix CO2 into target products is very desirable. In this work, the cyanobacterium, Synechocystis 6803, was engineered to grow on xylose in addition to glucose. Both the xylA (xylose isomerase) and xylB (xylulokinase) genes from Escherichia coli were required to confer xylose utilization, but a xylose-specific transporter was not required. Introducing xylAB into an ethylene-producing strain increased the rate of ethylene production in the presence of xylose. Additionally, introduction of xylAB into a glycogen-synthesis mutant enhanced production of keto acids. Moreover, isotopic tracer studies found that nearly half of the carbon in the excreted keto acids was derived from the engineered xylose metabolism, while the remainder was derived from CO2 fixation.

  12. Inhibition of hydrogen uptake in Escherichia coli by expressing the hydrogenase from the cyanobacterium Synechocystis sp. PCC 6803

    Directory of Open Access Journals (Sweden)

    Wood Thomas K

    2007-05-01

    Full Text Available Abstract Background Molecular hydrogen is an environmentally-clean fuel and the reversible (bi-directional hydrogenase of the cyanobacterium Synechocystis sp. PCC 6803 as well as the native Escherichia coli hydrogenase 3 hold great promise for hydrogen generation. These enzymes perform the simple reaction 2H+ + 2e- ↔ H2 (g. Results Hydrogen yields were enhanced up to 41-fold by cloning the bidirectional hydrogenase (encoded by hoxEFUYH from the cyanobacterium into E. coli. Using an optimized medium, E. coli cells expressing hoxEFUYH also produced twice as much hydrogen as the well-studied Enterobacter aerogenes HU-101, and hydrogen gas bubbles are clearly visible from the cultures. Overexpression of HoxU alone (small diaphorase subunit accounts for 43% of the additional hydrogen produced by HoxEFUYH. In addition, hydrogen production in E. coli mutants with defects in the native formate hydrogenlyase system show that the cyanobacterial hydrogenase depends on both the native E. coli hydrogenase 3 as well as on its maturation proteins. Hydrogen absorption by cells expressing hoxEFUYH was up to 10 times lower than cells which lack the cloned cyanobacterial hydrogenase; hence, the enhanced hydrogen production in the presence of hoxEFUYH is due to inhibition of hydrogen uptake activity in E. coli. Hydrogen uptake by cells expressing hoxEFUYH was suppressed in three wild-type strains and in two hycE mutants but not in a double mutant defective in hydrogenase 1 and hydrogenase 2; hence, the active cyanobacterial locus suppresses hydrogen uptake by hydrogenase 1 and hydrogenase 2 but not by hydrogenase 3. Differential gene expression indicated that overexpression of HoxEFUYH does not alter expression of the native E. coli hydrogenase system; instead, biofilm-related genes are differentially regulated by expression of the cyanobacterial enzymes which resulted in 2-fold elevated biofilm formation. This appears to be the first enhanced hydrogen production

  13. Protein Network Signatures Associated with Exogenous Biofuels Treatments in Cyanobacterium Synechocystis sp. PCC 6803

    International Nuclear Information System (INIS)

    Pei, Guangsheng; Chen, Lei; Wang, Jiangxin; Qiao, Jianjun; Zhang, Weiwen

    2014-01-01

    Although recognized as a promising microbial cell factory for producing biofuels, current productivity in cyanobacterial systems is low. To make the processes economically feasible, one of the hurdles, which need to be overcome is the low tolerance of hosts to toxic biofuels. Meanwhile, little information is available regarding the cellular responses to biofuels stress in cyanobacteria, which makes it challenging for tolerance engineering. Using large proteomic datasets of Synechocystis under various biofuels stress and environmental perturbation, a protein co-expression network was first constructed and then combined with the experimentally determined protein–protein interaction network. Proteins with statistically higher topological overlap in the integrated network were identified as common responsive proteins to both biofuels stress and environmental perturbations. In addition, a weighted gene co-expression network analysis was performed to distinguish unique responses to biofuels from those to environmental perturbations and to uncover metabolic modules and proteins uniquely associated with biofuels stress. The results showed that biofuel-specific proteins and modules were enriched in several functional categories, including photosynthesis, carbon fixation, and amino acid metabolism, which may represent potential key signatures for biofuels stress responses in Synechocystis. Network-based analysis allowed determination of the responses specifically related to biofuels stress, and the results constituted an important knowledge foundation for tolerance engineering against biofuels in Synechocystis.

  14. Protein Network Signatures Associated with Exogenous Biofuels Treatments in Cyanobacterium Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Pei, Guangsheng; Chen, Lei; Wang, Jiangxin; Qiao, Jianjun; Zhang, Weiwen

    2014-01-01

    Although recognized as a promising microbial cell factory for producing biofuels, current productivity in cyanobacterial systems is low. To make the processes economically feasible, one of the hurdles, which need to be overcome is the low tolerance of hosts to toxic biofuels. Meanwhile, little information is available regarding the cellular responses to biofuels stress in cyanobacteria, which makes it challenging for tolerance engineering. Using large proteomic datasets of Synechocystis under various biofuels stress and environmental perturbation, a protein co-expression network was first constructed and then combined with the experimentally determined protein-protein interaction network. Proteins with statistically higher topological overlap in the integrated network were identified as common responsive proteins to both biofuels stress and environmental perturbations. In addition, a weighted gene co-expression network analysis was performed to distinguish unique responses to biofuels from those to environmental perturbations and to uncover metabolic modules and proteins uniquely associated with biofuels stress. The results showed that biofuel-specific proteins and modules were enriched in several functional categories, including photosynthesis, carbon fixation, and amino acid metabolism, which may represent potential key signatures for biofuels stress responses in Synechocystis. Network-based analysis allowed determination of the responses specifically related to biofuels stress, and the results constituted an important knowledge foundation for tolerance engineering against biofuels in Synechocystis.

  15. Altering the Structure of Carbohydrate Storage Granules in the Cyanobacterium Synechocystis sp. Strain PCC 6803 through Branching-Enzyme Truncations

    Science.gov (United States)

    Welkie, David G.; Lee, Byung-Hoo

    2015-01-01

    ABSTRACT Carbohydrate storage is an important element of metabolism in cyanobacteria and in the chloroplasts of plants. Understanding how to manipulate the metabolism and storage of carbohydrate is also an important factor toward harnessing cyanobacteria for energy production. While most cyanobacteria produce glycogen, some have been found to accumulate polysaccharides in the form of water-insoluble α-glucan similar to amylopectin. Notably, this alternative form, termed “semi-amylopectin,” forms in cyanobacterial species harboring three branching-enzyme (BE) homologs, designated BE1, BE2, and BE3. In this study, mutagenesis of the branching genes found in Synechocystis sp. strain PCC 6803 was performed in order to characterize their possible impact on polysaccharide storage granule morphology. N-terminal truncations were made to the native BE gene of Synechocystis sp. PCC 6803. In addition, one of the two native debranching enzyme genes was replaced with a heterologous debranching enzyme gene from a semi-amylopectin-forming strain. Growth and glycogen content of mutant strains did not significantly differ from those of the wild type, and ultrastructure analysis revealed only slight changes to granule morphology. However, analysis of chain length distribution by anion-exchange chromatography revealed modest changes to the branched-chain length profile. The resulting glycogen shared structure characteristics similar to that of granules isolated from semi-amylopectin-producing strains. IMPORTANCE This study is the first to investigate the impact of branching-enzyme truncations on the structure of storage carbohydrates in cyanobacteria. The results of this study are an important contribution toward understanding the relationship between the enzymatic repertoire of a cyanobacterial species and the morphology of its storage carbohydrates. PMID:26668264

  16. Development of a quantitative SRM-based proteomics method to study iron metabolism of Synechocystis sp PCC 6803

    NARCIS (Netherlands)

    Vuorijoki, L.; Isojärvi, J.; Kallio, P.; Kouvonen, P.; Aro, E.M.; Corthals, G.L.; Jones, P.R.; Muth-Pawlak, D.

    2016-01-01

    The cyanobacterium Synechocystis sp. PCC 6803 (S. 6803) is a well-established model species in oxygenic photosynthesis research and a potential host for biotechnological applications. Despite recent advances in genome sequencing and microarray techniques applied in systems biology, quantitative

  17. Enhanced accumulation of glycogen, lipids and polyhydroxybutyrate under optimal nutrients and light intensities in the cyanobacterium Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Monshupanee, T; Incharoensakdi, A

    2014-04-01

    Glycogen (GL) and lipids (LP) are efficient biofuel substrates, whereas polyhydroxybutyrate (PHB) is a potent biodegradable plastic. This study aimed to increase accumulation of these three compounds in Synechocystis sp. PCC 6803. Under autophototrophic growth, co-accumulation of the three compounds reached maximum level in a mid-stationary phase at 39·2% of dry weight (22·7% GL, 14·1% LP and 2·4% PHB). Nitrogen deprivation increased this to 61·5% (36·8% GL, 11·2% LP and 13·5% PHB), higher than that achieved by phosphorus, sulfur, iron or calcium deprivation. Combining nitrogen deprivation with 0·4% (w/v) glucose addition for heterophototrophic growth and optimizing the light intensity (200 μmol photons m(-2) s(-1) ) synergistically enhanced combined accumulation to 71·1% of biomass (41·3% GL, 16·7% LP and 13·1% PHB), a higher level than previously reported in Synechocystis. However, the maximum coproductivity of GL, LP and PHB (at 0·72 g l(-1) ) was obtained in the 12-day heterophototrophic culture without nitrogen deprivation. Accumulation of GL, LP and PHB was enhanced under both autophototrophic and heterophototrophic conditions by optimizations of nutrient and light supplies. This study provides a means for increasing co-production of potent bioenergy substrates and useful biomaterials in Synechocystis which may also be applicable to other cyanobacteria. © 2013 The Society for Applied Microbiology.

  18. Biotransformation of 6-deoxypseudoanisatin by Synechocystis sp. PCC6803

    Directory of Open Access Journals (Sweden)

    Zhi Wang

    2014-10-01

    Conclusion: Thus, the study appears to demonstrate that Synechocystis sp. PCC6803 can transform 6-deoxypseudoanisatin. The polarity of the converted product is less than that of 6-deoxypseudoanisatin.

  19. Genetics of the Blue Light-Dependent Signal Cascade That Controls Phototaxis in the Cyanobacterium Synechocystis sp. PCC6803.

    Science.gov (United States)

    Sugimoto, Yuki; Nakamura, Hiroshi; Ren, Shukun; Hori, Koichi; Masuda, Shinji

    2017-03-01

    The Synechocystis sp. PCC6803 can move on a solid surface in response to light, a phenomenon called phototaxis. Although many of the photoreceptors involved in phototaxis have been identified, the mechanisms that regulate directional motility of Synechocystis are not well understood. Previous studies showed that a mutant lacking the blue light-using flavin (BLUF) photoreceptor PixD exhibits negative phototaxis under conditions where the wild type responds positively. PixD interacts with the pseudo-response regulator-like protein PixE in a light-dependent manner, suggesting that this intermolecular interaction is important for phototaxis regulation, although genetic evidence has been lacking. To gain further insight into phototaxis regulation by PixD-PixE signaling, we constructed the deletion mutants ΔPixE and ΔPixD-ΔPixE, and characterized their phenotypes, which matched those of the wild type (positive phototaxis). Because ΔPixD exhibited negative phototaxis, PixE must function downstream of PixD. Under intense blue light (>100 μmol m-2 s-1; 470 nm) the wild type exhibited negative phototaxis, but ΔPixD-PixE exhibited positive phototaxis toward low-intensity blue light (∼0.8 μmol m-2 s-1; 470 nm). These results suggest that an unknown light-sensing system(s), that is necessary for directional cell movement, can be activated by low-intensity blue light; on the other hand, PixD needs high-intensity blue light to be activated. We also isolated spontaneous mutants that compensated for the pixE deletion. Genome-wide sequencing of the mutants revealed that the uncharacterized gene sll2003 regulates positive and negative phototaxis in response to light intensity. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  20. Polyhydroxybutyrate particles in Synechocystis sp PCC 6803: facts and fiction

    Energy Technology Data Exchange (ETDEWEB)

    Tsang, TK; Roberson, RW; Vermaas, WFJ

    2013-09-20

    Transmission electron microscopy has been used to identify poly-3-hydroxybutyrate (PHB) granules in cyanobacteria for over 40 years. Spherical inclusions inside the cell that are electron-transparent and/or slightly electron-dense and that are found in transmission electron micrographs of cyanobacteria are generally assumed to be PHB granules. The aim of this study was to test this assumption in different strains of the cyanobacterium Synechocystis sp. PCC 6803. Inclusions that resemble PHB granules were present in strains lacking a pair of genes essential for PHB synthesis and in wild-type cells under conditions that no PHB granules could be detected by fluorescence staining of PHB. Indeed, in these cells PHB could not be demonstrated chemically by GC/MS either. Based on the results gathered, it is concluded that not all the slightly electron-dense spherical inclusions are PHB granules in Synechocystis sp. PCC 6803. This result is potentially applicable to other cyanobacteria. Alternate assignments for these inclusions are discussed.

  1. A photosystem 1 psaFJ-null mutant of the cyanobacterium Synechocystis PCC 6803 expresses the isiAB operon under iron replete conditions

    NARCIS (Netherlands)

    Jeanjean, Robert; Zuther, Ellen; Yeremenko, Nataliya; Havaux, Michel; Matthijs, Hans C. P.; Hagemann, Martin

    2003-01-01

    A psaFJ-null mutant of Synechocystis sp. strain PCC 6803 was characterised. As opposed to similar mutants in chloroplasts of green algae, electron transfer from plastocyanin to photosystem 1 was not affected. Instead, a restraint in full chain photosynthetic electron transfer was correlated to

  2. Impact of different group 2 sigma factors on light use efficiency and high salt stress in the cyanobacterium Synechocystis sp. PCC 6803.

    Directory of Open Access Journals (Sweden)

    Taina Tyystjärvi

    Full Text Available Sigma factors of RNA polymerase recognize promoters and have a central role in controlling transcription initiation and acclimation to changing environmental conditions. The cyanobacterium Synechocystis sp. PCC 6803 encodes four non-essential group 2 sigma factors, SigB, SigC, SigD and SigE that closely resemble the essential SigA factor. Three out of four group 2 sigma factors were simultaneously inactivated and acclimation responses of the triple inactivation strains were studied. All triple inactivation strains grew slowly in low light, and our analysis suggests that the reason is a reduced capacity to adjust the perception of light. Simultaneous inactivation of SigB and SigD hampered growth also in high light. SigB is the most important group 2 sigma factor for salt acclimation, and elimination of all the other group 2 sigma factors slightly improved the salt tolerance of Synechocystis. Presence of only SigE allowed full salt acclimation including up-regulation of hspA and ggpS genes, but more slowly than SigB. Cells with only SigD acclimated to high salt but the acclimation processes differed from those of the control strain. Presence of only SigC prevented salt acclimation.

  3. Acetylome analysis reveals the involvement of lysine acetylation in photosynthesis and carbon metabolism in the model cyanobacterium Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Mo, Ran; Yang, Mingkun; Chen, Zhuo; Cheng, Zhongyi; Yi, Xingling; Li, Chongyang; He, Chenliu; Xiong, Qian; Chen, Hui; Wang, Qiang; Ge, Feng

    2015-02-06

    Cyanobacteria are the oldest known life form inhabiting Earth and the only prokaryotes capable of performing oxygenic photosynthesis. Synechocystis sp. PCC 6803 (Synechocystis) is a model cyanobacterium used extensively in research on photosynthesis and environmental adaptation. Posttranslational protein modification by lysine acetylation plays a critical regulatory role in both eukaryotes and prokaryotes; however, its extent and function in cyanobacteria remain unexplored. Herein, we performed a global acetylome analysis on Synechocystis through peptide prefractionation, antibody enrichment, and high accuracy LC-MS/MS analysis; identified 776 acetylation sites on 513 acetylated proteins; and functionally categorized them into an interaction map showing their involvement in various biological processes. Consistent with previous reports, a large fraction of the acetylation sites are present on proteins involved in cellular metabolism. Interestingly, for the first time, many proteins involved in photosynthesis, including the subunits of phycocyanin (CpcA, CpcB, CpcC, and CpcG) and allophycocyanin (ApcA, ApcB, ApcD, ApcE, and ApcF), were found to be lysine acetylated, suggesting that lysine acetylation may play regulatory roles in the photosynthesis process. Six identified acetylated proteins associated with photosynthesis and carbon metabolism were further validated by immunoprecipitation and Western blotting. Our data provide the first global survey of lysine acetylation in cyanobacteria and reveal previously unappreciated roles of lysine acetylation in the regulation of photosynthesis. The provided data set may serve as an important resource for the functional analysis of lysine acetylation in cyanobacteria and facilitate the elucidation of the entire metabolic networks and photosynthesis process in this model cyanobacterium.

  4. Increased biomass production and glycogen accumulation in apcE gene deleted Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Joseph, Ancy; Aikawa, Shimpei; Sasaki, Kengo; Matsuda, Fumio; Hasunuma, Tomohisa; Kondo, Akihiko

    2014-01-01

    The effect of phycobilisome antenna-truncation in the cyanobacterium Synechocystis sp. PCC 6803 on biomass production and glycogen accumulation have not yet been fully clarified. To investigate these effects here, the apcE gene, which encodes the anchor protein linking the phycobilisome to the thylakoid membrane, was deleted in a glucose tolerant strain of Synechocystis sp. PCC 6803. Biomass production of the apcE-deleted strain under photoautotrophic and atmospheric air conditions was 1.6 times higher than that of strain PCC 6803 (1.32 ± 0.01 versus 0.84 ± 0.07 g cell-dry weight L(-1), respectively) after 15 days of cultivation. In addition, the glycogen content of the apcE-deleted strain (24.2 ± 0.7%) was also higher than that of strain PCC 6803 (11.1 ± 0.3%). Together, these results demonstrate that antenna truncation by deleting the apcE gene was effective for increasing biomass production and glycogen accumulation under photoautotrophic and atmospheric air conditions in Synechocystis sp. PCC 6803.

  5. Co-ordination of NDH and Cup proteins in CO2 uptake in cyanobacterium Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Han, Xunling; Sun, Nan; Xu, Min; Mi, Hualing

    2017-06-01

    High and low affinity CO2-uptake systems containing CupA (NDH-1MS) and CupB (NDH-1MS'), respectively, have been identified in Synechocystis sp. PCC 6803, but it is yet unknown how the complexes function in CO2 uptake. In this work, we found that deletion of cupB significantly lowered the growth of cells, and deletion of both cupA and cupB seriously suppressed the growth below pH 7.0 even under 3% CO2. The rate of photosynthetic oxygen evolution was decreased slightly by deletion of cupA but significantly by deletion of cupB and more severely by deletion of both cupA and cupB, especially in response to changed pH conditions under 3% CO2. Furthermore, we found that assembly of CupB into NDH-1MS' was dependent on NdhD4 and NdhF4. NDH-1MS' was not affected in the NDH-1MS-degradation mutant and NDH-1MS was not affected in the NDH-1MS'-degradation mutants, indicating the existence of independent CO2-uptake systems under high CO2 conditions. The light-induced proton gradient across thylakoid membranes was significantly inhibited in ndhD-deletion mutants, suggesting that NdhDs functions in proton pumping. The carbonic anhydrase activity was suppressed partly in the cupA- or cupB-deletion mutant but severely in the mutant with both cupA and cupB deletion, indicating that CupA and CupB function in conversion of CO2 to HCO3-. In turn, deletion of cup genes lowered the transthylakoid membrane proton gradient and deletion of ndhDs decreased the CO2 hydration. Our results suggest that NDH-1M provides an alkaline region to activate Cup proteins involved in CO2 uptake. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  6. Outer Membrane Permeability of Cyanobacterium Synechocystis sp. Strain PCC 6803: Studies of Passive Diffusion of Small Organic Nutrients Reveal the Absence of Classical Porins and Intrinsically Low Permeability

    Science.gov (United States)

    Kowata, Hikaru; Tochigi, Saeko; Takahashi, Hideyuki

    2017-01-01

    ABSTRACT The outer membrane of heterotrophic Gram-negative bacteria plays the role of a selective permeability barrier that prevents the influx of toxic compounds while allowing the nonspecific passage of small hydrophilic nutrients through porin channels. Compared with heterotrophic Gram-negative bacteria, the outer membrane properties of cyanobacteria, which are Gram-negative photoautotrophs, are not clearly understood. In this study, using small carbohydrates, amino acids, and inorganic ions as permeation probes, we determined the outer membrane permeability of Synechocystis sp. strain PCC 6803 in intact cells and in proteoliposomes reconstituted with outer membrane proteins. The permeability of this cyanobacterium was >20-fold lower than that of Escherichia coli. The predominant outer membrane proteins Slr1841, Slr1908, and Slr0042 were not permeable to organic nutrients and allowed only the passage of inorganic ions. Only the less abundant outer membrane protein Slr1270, a homolog of the E. coli export channel TolC, was permeable to organic solutes. The activity of Slr1270 as a channel was verified in a recombinant Slr1270-producing E. coli outer membrane. The lack of putative porins and the low outer membrane permeability appear to suit the cyanobacterial autotrophic lifestyle; the highly impermeable outer membrane would be advantageous to cellular survival by protecting the cell from toxic compounds, especially when the cellular physiology is not dependent on the uptake of organic nutrients. IMPORTANCE Because the outer membrane of Gram-negative bacteria affects the flux rates for various substances into and out of the cell, its permeability is closely associated with cellular physiology. The outer membrane properties of cyanobacteria, which are photoautotrophic Gram-negative bacteria, are not clearly understood. Here, we examined the outer membrane of Synechocystis sp. strain PCC 6803. We revealed that it is relatively permeable to inorganic ions but is

  7. Cloning of a Nitrilase Gene from the Cyanobacterium Synechocystis sp. Strain PCC6803 and Heterologous Expression and Characterization of the Encoded Protein

    Science.gov (United States)

    Heinemann, Ute; Engels, Dirk; Bürger, Sibylle; Kiziak, Christoph; Mattes, Ralf; Stolz, Andreas

    2003-01-01

    The gene encoding a putative nitrilase was identified in the genome sequence of the photosynthetic cyanobacterium Synechocystis sp. strain PCC6803. The gene was amplified by PCR and cloned into an expression vector. The encoded protein was heterologously expressed in the native form and as a His-tagged protein in Escherichia coli, and the recombinant strains were shown to convert benzonitrile to benzoate. The active enzyme was purified to homogeneity and shown by gel filtration to consist probably of 10 subunits. The purified nitrilase converted various aromatic and aliphatic nitriles. The highest enzyme activity was observed with fumarodinitrile, but also some rather hydrophobic aromatic (e.g., naphthalenecarbonitrile), heterocyclic (e.g., indole-3-acetonitrile), or long-chain aliphatic (di-)nitriles (e.g., octanoic acid dinitrile) were converted with higher specific activities than benzonitrile. From aliphatic dinitriles with less than six carbon atoms only 1 mol of ammonia was released per mol of dinitrile, and thus presumably the corresponding cyanocarboxylic acids formed. The purified enzyme was active in the presence of a wide range of organic solvents and the turnover rates of dodecanoic acid nitrile and naphthalenecarbonitrile were increased in the presence of water-soluble and water-immiscible organic solvents. PMID:12902216

  8. The small CAB-like proteins of the cyanobacterium Synechocystis sp. PCC 6803: their involvement in chlorophyll biogenesis for Photosystem II.

    Science.gov (United States)

    Hernandez-Prieto, Miguel A; Tibiletti, Tania; Abasova, Leyla; Kirilovsky, Diana; Vass, Imre; Funk, Christiane

    2011-09-01

    The five small CAB-like proteins (ScpA-E) of the cyanobacterium Synechocystis sp. PCC 6803 belong to the family of stress-induced light-harvesting-like proteins, but are constitutively expressed in a mutant deficient of Photosystem I (PSI). Using absorption, fluorescence and thermoluminescence measurements this PSI-less strain was compared with a mutant, in which all SCPs were additionally deleted. Depletion of SCPs led to structural rearrangements in Photosystem II (PSII): less photosystems were assembled; and in these, the Q(B) site was modified. Despite the lower amount of PSII, the SCP-deficient cells contained the same amount of phycobilisomes (PBS) as the control. Although the excess PBS were functionally disconnected, their fluorescence was quenched under high irradiance by the activated Orange Carotenoid Protein (OCP). Additionally the amount of OCP, but not of the iron-stress induced protein (isiA), was higher in this SCP-depleted mutant compared with the control. As previously described, the lack of SCPs affects the chlorophyll biosynthesis (Vavilin, D., Brune, D. C., Vermaas, W. (2005) Biochim Biophys Acta 1708, 91-101). We demonstrate that chlorophyll synthesis is required for efficient PSII repair and that it is partly impaired in the absence of SCPs. At the same time, the amount of chlorophyll also seems to influence the expression of ScpC and ScpD. 2011 Elsevier B.V. All rights reserved.

  9. Premethylation of Foreign DNA Improves Integrative Transformation Efficiency in Synechocystis sp. Strain PCC 6803

    OpenAIRE

    Wang, Bo; Yu, Jianping; Zhang, Weiwen; Meldrum, Deirdre R.

    2015-01-01

    Restriction digestion of foreign DNA is one of the key biological barriers against genetic transformation in microorganisms. To establish a high-efficiency transformation protocol in the model cyanobacterium, Synechocystis sp. strain PCC 6803 (Synechocystis 6803), we investigated the effects of premethylation of foreign DNA on the integrative transformation of this strain. In this study, two type II methyltransferase-encoding genes, i.e., sll0729 (gene M) and slr0214 (gene C), were cloned fro...

  10. A functional compartmental model of the Synechocystis PCC 6803 phycobilisome

    NARCIS (Netherlands)

    van Stokkum, Ivo H. M.; Gwizdala, Michal; Tian, Lijin; Snellenburg, Joris J.; van Grondelle, Rienk; van Amerongen, Herbert; Berera, Rudi

    In the light-harvesting antenna of the Synechocystis PCC 6803 phycobilisome (PB), the core consists of three cylinders, each composed of four disks, whereas each of the six rods consists of up to three hexamers (Arteni et al., Biochim Biophys Acta 1787(4):272–279, 2009). The rods and core contain

  11. A functional compartmental model of the Synechocystis PCC 6803 phycobilisome

    NARCIS (Netherlands)

    Stokkum, van Ivo H.M.; Gwizdala, Michal; Tian, Tian; Snellenburg, Joris J.; Grondelle, van Rienk; Amerongen, van Herbert; Berera, Rudi

    2018-01-01

    In the light-harvesting antenna of the Synechocystis PCC 6803 phycobilisome (PB), the core consists of three cylinders, each composed of four disks, whereas each of the six rods consists of up to three hexamers (Arteni et al., Biochim Biophys Acta 1787(4):272–279, 2009). The rods and core contain

  12. The Nitrogen-regulated Response Regulator NrrA Controls Cyanophycin Synthesis and Glycogen Catabolism in the Cyanobacterium Synechocystis sp. PCC 6803*

    Science.gov (United States)

    Liu, Deng; Yang, Chen

    2014-01-01

    The cellular metabolism in cyanobacteria is extensively regulated in response to changes of environmental nitrogen availability. Multiple regulators are involved in this process, including a nitrogen-regulated response regulator NrrA. However, the regulatory role of NrrA in most cyanobacteria remains to be elucidated. In this study, we combined a comparative genomic reconstruction of NrrA regulons in 15 diverse cyanobacterial species with detailed experimental characterization of NrrA-mediated regulation in Synechocystis sp. PCC 6803. The reconstructed NrrA regulons in most species included the genes involved in glycogen catabolism, central carbon metabolism, amino acid biosynthesis, and protein degradation. A predicted NrrA-binding motif consisting of two direct repeats of TG(T/A)CA separated by an 8-bp A/T-rich spacer was verified by in vitro binding assays with purified NrrA protein. The predicted target genes of NrrA in Synechocystis sp. PCC 6803 were experimentally validated by comparing the transcript levels and enzyme activities between the wild-type and nrrA-inactivated mutant strains. The effect of NrrA deficiency on intracellular contents of arginine, cyanophycin, and glycogen was studied. Severe impairments in arginine synthesis and cyanophycin accumulation were observed in the nrrA-inactivated mutant. The nrrA inactivation also resulted in a significantly decreased rate of glycogen degradation. Our results indicate that by directly up-regulating expression of the genes involved in arginine synthesis, glycogen degradation, and glycolysis, NrrA controls cyanophycin accumulation and glycogen catabolism in Synechocystis sp. PCC 6803. It is suggested that NrrA plays a role in coordinating the synthesis and degradation of nitrogen and carbon reserves in cyanobacteria. PMID:24337581

  13. TonB-Dependent Utilization of Dihydroxamate Xenosiderophores in Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Babykin, Michael M; Obando, Tobias S A; Zinchenko, Vladislav V

    2018-02-01

    In Gram-negative bacteria, transport of ferric siderophores through outer membrane is a complex process that requires specific outer membrane transporters and energy-transducing TonB-ExbB-ExbD system in the cytoplasmic membrane. The genome of the non-siderophore-producing cyanobacterium Synechocystis sp. PCC 6803 encodes all putative components of the siderophore-mediated iron uptake system. So far, there has been no experimental evidence for the existence of such a pathway in this organism. On the contrary, its reductive iron uptake pathway has been studied in detail. We demonstrate that Synechocystis sp. PCC 6803 is capable of using dihydroxamate xenosiderophores, either ferric schizokinen (FeSK) or a siderophore of the filamentous cyanobacterium Anabaena variabilis ATCC 29413 (SAV), as the sole source of iron. Inactivation of the tonB gene or the exbB1-exbD1 gene cluster resulted in an inability to utilize these siderophores. At the same time, the inactivation of the feoB gene encoding FeoB plasma membrane ferrous iron transporter, or one of the futB or futC genes encoding permease and ATPase subunit of FutABC ferric iron transporter, did not impair the ability of cells to utilize FeSK or SAV as the sole source of iron for growth. Our data suggest that cyanobacterium Synechocystis sp. PCC 6803 is capable of acquiring iron-siderophore complexes in a TonB-dependent manner without iron reduction in the periplasm.

  14. Sll0528, a Site-2-Protease, Is Critically Involved in Cold, Salt and Hyperosmotic Stress Acclimation of Cyanobacterium Synechocystis sp. PCC 6803

    Directory of Open Access Journals (Sweden)

    Haijin Lei

    2014-12-01

    Full Text Available Site-2-proteases (S2Ps mediated proteolysis of transmembrane transcriptional regulators is a conserved mechanism to regulate transmembrane signaling. The universal presence of S2P homologs in different cyanobacterial genomes suggest conserved and fundamental functions, though limited data has been available. Here we provide the first evidence that Sll0528, a site-2-protease in Synechocystis sp. PCC 6803 is crucial for salt, cold and hyperosmotic stress acclimation. Remarkable induction of sll0528 gene expression was observed under salt, cold and hyperosmotic stress, much higher than induction of the other three S2Ps. Knock-out of sll0528 gene in wild type Synechocystis sp. PCC 6803 increased their sensitivity to salt, cold and hyperosmotic stress, as revealed by retarded growth, reduced pigments and disrupted photosystems. The sll0528 gene was induced to a much smaller extent by high light and mixotrophic growth with glucose. Similar growth responses of the sll0528 knockout mutant and wild type under high light and mixotrophic growth indicated that sll0528 was dispensable for these conditions. Recombinant Sll0528 protein could cleave beta-casein into smaller fragments. These results together suggest that the Sll0528 metalloprotease plays a role in the stress response and lays the foundation for further investigation of its mechanism, as well as providing hints for the functional analysis of other S2Ps in cyanobacteria.

  15. Carbon sink removal: Increased photosynthetic production of lactic acid by Synechocystis sp. PCC6803 in a glycogen storage mutant

    NARCIS (Netherlands)

    van der Woude, A.D.; Angermayr, S.A.; Puthan Veetil, V.; Osnato, A.; Hellingwerf, K.J.

    2014-01-01

    Deletion of pathways for carbon-storage in the cyanobacterium Synechocystis sp. PCC6803 has been suggested as a strategy to increase the size of the available pyruvate pool for the production of (heterologous) chemical commodities. Here we show that deletion of the pathway for glycogen synthesis

  16. Synthesis of Chlorophyll-Binding Proteins in a Fully Segregated Delta ycf54 Strain of the Cyanobacterium Synechocystis PCC 6803

    Czech Academy of Sciences Publication Activity Database

    Hollingshead, S.; Kopečná, Jana; Armstrong, D.R.; Bučinská, Lenka; Jackson, P. J.; Chen, G.E.; Dickman, M. J.; Williamson, M.P.; Sobotka, Roman; Hunter, C. N.

    2016-01-01

    Roč. 7, March 2016 (2016), s. 292 ISSN 1664-462X R&D Projects: GA ČR(CZ) GA14-13967S; GA MŠk(CZ) LO1416 Institutional support: RVO:61388971 Keywords : Ycf54 * Synechocystis 6803 * chlorophyll Subject RIV: EF - Botanics Impact factor: 4.298, year: 2016

  17. Protein engineering of α-ketoisovalerate decarboxylase for improved isobutanol production in Synechocystis PCC 6803.

    Science.gov (United States)

    Miao, Rui; Xie, Hao; M Ho, Felix; Lindblad, Peter

    2018-03-01

    Protein engineering is a powerful tool to modify e.g. protein stability, activity and substrate selectivity. Heterologous expression of the enzyme α-ketoisovalerate decarboxylase (Kivd) in the unicellular cyanobacterium Synechocystis PCC 6803 results in cells producing isobutanol and 3-methyl-1-butanol, with Kivd identified as a potential bottleneck. In the present study, we used protein engineering of Kivd to improve isobutanol production in Synechocystis PCC 6803. Isobutanol is a flammable compound that can be used as a biofuel due to its high energy density and suitable physical and chemical properties. Single replacement, either Val461 to isoleucine or Ser286 to threonine, increased the Kivd activity significantly, both in vivo and in vitro resulting in increased overall production while isobutanol production was increased more than 3-methyl-1-butanol production. Moreover, among all the engineered strains examined, the strain with the combined modification V461I/S286T showed the highest (2.4 times) improvement of isobutanol-to-3M1B molar ratio, which was due to a decrease of the activity towards 3M1B production. Protein engineering of Kivd resulted in both enhanced total catalytic activity and preferential shift towards isobutanol production in Synechocystis PCC 6803. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  18. FLAVODIIRON2 and FLAVODIIRON4 Proteins Mediate an Oxygen-Dependent Alternative Electron Flow in Synechocystis sp. PCC 6803 under CO2-Limited Conditions1[OPEN

    Science.gov (United States)

    Shimakawa, Ginga; Shaku, Keiichiro; Nishi, Akiko; Hayashi, Ryosuke; Yamamoto, Hiroshi; Sakamoto, Katsuhiko; Makino, Amane; Miyake, Chikahiro

    2015-01-01

    This study aims to elucidate the molecular mechanism of an alternative electron flow (AEF) functioning under suppressed (CO2-limited) photosynthesis in the cyanobacterium Synechocystis sp. PCC 6803. Photosynthetic linear electron flow, evaluated as the quantum yield of photosystem II [Y(II)], reaches a maximum shortly after the onset of actinic illumination. Thereafter, Y(II) transiently decreases concomitantly with a decrease in the photosynthetic oxygen evolution rate and then recovers to a rate that is close to the initial maximum. These results show that CO2 limitation suppresses photosynthesis and induces AEF. In contrast to the wild type, Synechocystis sp. PCC 6803 mutants deficient in the genes encoding FLAVODIIRON2 (FLV2) and FLV4 proteins show no recovery of Y(II) after prolonged illumination. However, Synechocystis sp. PCC 6803 mutants deficient in genes encoding proteins functioning in photorespiration show AEF activity similar to the wild type. In contrast to Synechocystis sp. PCC 6803, the cyanobacterium Synechococcus elongatus PCC 7942 has no FLV proteins with high homology to FLV2 and FLV4 in Synechocystis sp. PCC 6803. This lack of FLV2/4 may explain why AEF is not induced under CO2-limited photosynthesis in S. elongatus PCC 7942. As the glutathione S-transferase fusion protein overexpressed in Escherichia coli exhibits NADH-dependent oxygen reduction to water, we suggest that FLV2 and FLV4 mediate oxygen-dependent AEF in Synechocystis sp. PCC 6803 when electron acceptors such as CO2 are not available. PMID:25540330

  19. Identification and localization of the CupB protein involved in constitutive CO2 uptake in the cyanobacterium, Synechocystis sp. strain PCC 6803.

    Science.gov (United States)

    Xu, Min; Ogawa, Teruo; Pakrasi, Himadri B; Mi, Hualing

    2008-06-01

    Antibody against cMyc cross-reacted strongly with the CupB protein tagged with His6-cMyc (HM) in thylakoid membrane of Synechocystis sp. strain PCC 6803 but only faintly with the cytoplasmic membrane fraction. The protein was not detected in the membranes of the DeltandhD4 and DeltandhF4 mutants in which CupB was tagged with HM. We concluded that a CupB complex containing NdhD4 and NdhF4 is largely, if not exclusively, confined to the thylakoid membrane. Both CupB and NdhH were detected in a fraction containing protein complexes of > 450 kDa, obtained after nickel column and gel filtration chromatography of the membranes solubilized with n-dodecyl-beta-maltoside.

  20. Resistance, accumulation and transformation of selenium by the cyanobacterium Synechocystis sp. PCC 6803 after exposure to inorganic SeVI or SeIV

    International Nuclear Information System (INIS)

    Gouget, B.; Avoscan, L.; Collins, R.; Carriere, M.; Sarret, G.

    2005-01-01

    Our purpose was to investigate the ability of Synechocystis sp. PCC 6803, a photosynthetic prokaryote isolated from fresh water, to resist, incorporate and reduce the oxidized forms of selenium including selenite and selenate, the major selenium species present in aquatic systems. Selenium speciation and the chemical intermediates during selenium transformation were determined by X-ray absorption near edge structure (XANES) spectroscopy. The possible internalisation pathways involving selenium and the metabolic fate of selenate and selenite were examined. Selenate metabolism seemed to proceed via the sulfate reduction pathway resulting in the formation of the R-Se-H, R-Se-R and R-Se-Se-R species. The transformation of selenate to toxic amino acids may explain the high sensitivity of Synechocystis to selenate. Several mechanisms of selenium reduction seem to complete during selenite assimilation. A specific mechanism may transform internalised selenite into selenide and, subsequently induce the biosynthesis of selenoproteins. A non-specific mechanism may interfere with thiols, such as glutathione in the cell cytoplasm, or with proteins in the periplasm of the bacteria, notably thioredoxins. Several hypotheses concerning the complex transformation of selenium in Synechocystis could therefore be proposed. (orig.)

  1. Bioinformatic evaluation of L-arginine catabolic pathways in 24 cyanobacteria and transcriptional analysis of genes encoding enzymes of L-arginine catabolism in the cyanobacterium Synechocystis sp. PCC 6803

    Directory of Open Access Journals (Sweden)

    Pistorius Elfriede K

    2007-11-01

    Full Text Available Abstract Background So far very limited knowledge exists on L-arginine catabolism in cyanobacteria, although six major L-arginine-degrading pathways have been described for prokaryotes. Thus, we have performed a bioinformatic analysis of possible L-arginine-degrading pathways in cyanobacteria. Further, we chose Synechocystis sp. PCC 6803 for a more detailed bioinformatic analysis and for validation of the bioinformatic predictions on L-arginine catabolism with a transcript analysis. Results We have evaluated 24 cyanobacterial genomes of freshwater or marine strains for the presence of putative L-arginine-degrading enzymes. We identified an L-arginine decarboxylase pathway in all 24 strains. In addition, cyanobacteria have one or two further pathways representing either an arginase pathway or L-arginine deiminase pathway or an L-arginine oxidase/dehydrogenase pathway. An L-arginine amidinotransferase pathway as a major L-arginine-degrading pathway is not likely but can not be entirely excluded. A rather unusual finding was that the cyanobacterial L-arginine deiminases are substantially larger than the enzymes in non-photosynthetic bacteria and that they are membrane-bound. A more detailed bioinformatic analysis of Synechocystis sp. PCC 6803 revealed that three different L-arginine-degrading pathways may in principle be functional in this cyanobacterium. These are (i an L-arginine decarboxylase pathway, (ii an L-arginine deiminase pathway, and (iii an L-arginine oxidase/dehydrogenase pathway. A transcript analysis of cells grown either with nitrate or L-arginine as sole N-source and with an illumination of 50 μmol photons m-2 s-1 showed that the transcripts for the first enzyme(s of all three pathways were present, but that the transcript levels for the L-arginine deiminase and the L-arginine oxidase/dehydrogenase were substantially higher than that of the three isoenzymes of L-arginine decarboxylase. Conclusion The evaluation of 24

  2. Flux coupling and transcriptional regulation within the metabolic network of the photosynthetic bacterium Synechocystis sp. PCC6803

    DEFF Research Database (Denmark)

    Montagud, Arnau; Zelezniak, Aleksej; Navarro, Emilio

    2011-01-01

    Synechocystis sp. PCC6803 is a model cyanobacterium capable of producing biofuels with CO2 as carbon source and with its metabolism fueled by light, for which it stands as a potential production platform of socio-economic importance. Compilation and characterization of Synechocystis genome...... networks, surrounded by a stable core of pathways leading to biomass building blocks. This analysis identified potential bottlenecks for hydrogen and ethanol production. Integration of transcriptomic data with the Synechocystis flux coupling networks lead to identification of reporter flux coupling pairs...... and reporter flux coupling groups - regulatory hot spots during metabolic shifts triggered by the availability of light. Overall, flux coupling analysis provided insight into the structural organization of Synechocystis sp. PCC6803 metabolic network toward designing of a photosynthesis-based production...

  3. Effect of malic enzyme on ethanol production by Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Yoshikawa, Katsunori; Hirasawa, Takashi; Shimizu, Hiroshi

    2015-01-01

    We investigated effects of malic enzyme on ethanol production by Synechocystis sp. PCC 6803 under autotrophic conditions. Deletion of me, which encodes malic enzyme, decreased ethanol production, whereas its overexpression had no effect. Our results suggest that maintaining optimal malic enzyme activity controls ethanol production by Synechocystis sp. PCC 6803. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  4. Free fatty acid production in the cyanobacterium Synechocystis sp. PCC 6803 is enhanced by deletion of the cyAbrB2 transcriptional regulator.

    Science.gov (United States)

    Kawahara, Akihito; Sato, Yusuke; Saito, Yujiro; Kaneko, Yasuko; Takimura, Yasushi; Hagihara, Hiroshi; Hihara, Yukako

    2016-02-20

    The cyAbrB2 (Sll0822) transcriptional regulator in Synechocystis sp. PCC 6803 is involved in coordination of carbon and nitrogen metabolism and its deletion causes distinct phenotypes such as decreased expression levels of nitrogen-regulated genes and high accumulation of glycogen granules. From the viewpoint of metabolic engineering, the highly accumulated glycogen granules in the ΔcyabrB2 mutant could be a valuable source for the production of biofuels. Here, by disruption of the aas gene (slr1609) encoding acyl-acyl carrier protein synthetase and introduction of a gene encoding thioesterase from Umbellularia californica (UcTE), we conferred the ability of production and secretion of free fatty acids on the ΔcyabrB2 mutant. Notable features of the resulting ΔcyabrB2Δaas::UcTE strain compared with ΔcyabrB2 by RNA-seq analysis were decrease in expression levels of genes related to uptake and subsequent metabolism of nitrogen and carbon and increase in the expression level of sigE encoding a group 2 sigma factor. These changes in gene expression profile were not observed when the same genetic modification was introduced in the wild-type background. The ΔcyabrB2Δaas::UcTE strain showed two-folds higher free fatty acid productivity on a per OD730 basis compared with the Δaas::UcTE strain, without expense of the accumulated glycogen granules. This shows the potential of the ΔcyabrB2 mutant as the platform of biofuel production. The effective utilization of the accumulated glycogen must be the next task to be pursued. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Translation efficiency of heterologous proteins is significantly affected by the genetic context of RBS sequences in engineered cyanobacterium Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Thiel, Kati; Mulaku, Edita; Dandapani, Hariharan; Nagy, Csaba; Aro, Eva-Mari; Kallio, Pauli

    2018-03-02

    Photosynthetic cyanobacteria have been studied as potential host organisms for direct solar-driven production of different carbon-based chemicals from CO 2 and water, as part of the development of sustainable future biotechnological applications. The engineering approaches, however, are still limited by the lack of comprehensive information on most optimal expression strategies and validated species-specific genetic elements which are essential for increasing the intricacy, predictability and efficiency of the systems. This study focused on the systematic evaluation of the key translational control elements, ribosome binding sites (RBS), in the cyanobacterial host Synechocystis sp. PCC 6803, with the objective of expanding the palette of tools for more rigorous engineering approaches. An expression system was established for the comparison of 13 selected RBS sequences in Synechocystis, using several alternative reporter proteins (sYFP2, codon-optimized GFPmut3 and ethylene forming enzyme) as quantitative indicators of the relative translation efficiencies. The set-up was shown to yield highly reproducible expression patterns in independent analytical series with low variation between biological replicates, thus allowing statistical comparison of the activities of the different RBSs in vivo. While the RBSs covered a relatively broad overall expression level range, the downstream gene sequence was demonstrated in a rigorous manner to have a clear impact on the resulting translational profiles. This was expected to reflect interfering sequence-specific mRNA-level interaction between the RBS and the coding region, yet correlation between potential secondary structure formation and observed translation levels could not be resolved with existing in silico prediction tools. The study expands our current understanding on the potential and limitations associated with the regulation of protein expression at translational level in engineered cyanobacteria. The acquired

  6. Premethylation of foreign DNA improves integrative transformation efficiency in Synechocystis sp. strain PCC 6803.

    Science.gov (United States)

    Wang, Bo; Yu, Jianping; Zhang, Weiwen; Meldrum, Deirdre R

    2015-12-01

    Restriction digestion of foreign DNA is one of the key biological barriers against genetic transformation in microorganisms. To establish a high-efficiency transformation protocol in the model cyanobacterium, Synechocystis sp. strain PCC 6803 (Synechocystis 6803), we investigated the effects of premethylation of foreign DNA on the integrative transformation of this strain. In this study, two type II methyltransferase-encoding genes, i.e., sll0729 (gene M) and slr0214 (gene C), were cloned from the chromosome of Synechocystis 6803 and expressed in Escherichia coli harboring an integration plasmid. After premethylation treatment in E. coli, the integration plasmid was extracted and used for transformation of Synechocystis 6803. The results showed that although expression of methyltransferase M had little impact on the transformation of Synechocystis 6803, expression of methyltransferase C resulted in 11- to 161-fold-higher efficiency in the subsequent integrative transformation of Synechocystis 6803. Effective expression of methyltransferase C, which could be achieved by optimizing the 5' untranslated region, was critical to efficient premethylation of the donor DNA and thus high transformation efficiency in Synechocystis 6803. Since premethylating foreign DNA prior to transforming Synechocystis avoids changing the host genetic background, the study thus provides an improved method for high-efficiency integrative transformation of Synechocystis 6803. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  7. Ethylene production with engineered Synechocystis sp PCC 6803 strains.

    Science.gov (United States)

    Veetil, Vinod Puthan; Angermayr, S Andreas; Hellingwerf, Klaas J

    2017-02-23

    Metabolic engineering and synthetic biology of cyanobacteria offer a promising sustainable alternative approach for fossil-based ethylene production, by using sunlight via oxygenic photosynthesis, to convert carbon dioxide directly into ethylene. Towards this, both well-studied cyanobacteria, i.e., Synechocystis sp PCC 6803 and Synechococcus elongatus PCC 7942, have been engineered to produce ethylene by introducing the ethylene-forming enzyme (Efe) from Pseudomonas syringae pv. phaseolicola PK2 (the Kudzu strain), which catalyzes the conversion of the ubiquitous tricarboxylic acid cycle intermediate 2-oxoglutarate into ethylene. This study focuses on Synechocystis sp PCC 6803 and shows stable ethylene production through the integration of a codon-optimized version of the efe gene under control of the Ptrc promoter and the core Shine-Dalgarno sequence (5'-AGGAGG-3') as the ribosome-binding site (RBS), at the slr0168 neutral site. We have increased ethylene production twofold by RBS screening and further investigated improving ethylene production from a single gene copy of efe, using multiple tandem promoters and by putting our best construct on an RSF1010-based broad-host-self-replicating plasmid, which has a higher copy number than the genome. Moreover, to raise the intracellular amounts of the key Efe substrate, 2-oxoglutarate, from which ethylene is formed, we constructed a glycogen-synthesis knockout mutant (ΔglgC) and introduced the ethylene biosynthetic pathway in it. Under nitrogen limiting conditions, the glycogen knockout strain has increased intracellular 2-oxoglutarate levels; however, surprisingly, ethylene production was lower in this strain than in the wild-type background. Making use of different RBS sequences, production of ethylene ranging over a 20-fold difference has been achieved. However, a further increase of production through multiple tandem promoters and a broad-host plasmid was not achieved speculating that the transcription strength and

  8. Scaffold-fused riboregulators for enhanced gene activation in Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Sakai, Yuta; Abe, Koichi; Nakashima, Saki; Ellinger, James J; Ferri, Stefano; Sode, Koji; Ikebukuro, Kazunori

    2015-08-01

    Cyanobacteria are an attractive host for biofuel production because they can produce valuable chemical compounds from CO2 fixed by photosynthesis. However, the available genetic tools that enable precise gene regulation for the applications of synthetic biology are insufficient. Previously, we engineered an RNA-based posttranscriptional regulator, termed riboregulator, for the control of target gene expression in cyanobacterium Synechocystis sp. PCC 6803. Moreover, we enhanced the gene regulation ability of the riboregulators in Escherichia coli by fusing and engineering a scaffold sequence derived from naturally occurring E. coli noncoding small RNAs. Here, we demonstrated that the scaffold sequence fused to the riboregulators improved their gene regulation ability in Synechocystis sp. PCC 6803. To further improve gene regulation, we expressed an exogenous RNA chaperone protein that is responsible for noncoding small RNA-mediated gene regulation, which resulted in higher target gene expression. The scaffold sequence derived from natural E. coli noncoding small RNAs is effective for designing RNA-based genetic tools and scaffold-fused riboregulators are a strong RNA-tool to regulate gene expression in cyanobacteria. © 2015 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  9. Microevolution in cyanobacteria: re-sequencing a motile substrain of Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Trautmann, Danika; Voss, Björn; Wilde, Annegret; Al-Babili, Salim; Hess, Wolfgang R

    2012-12-01

    Synechocystis sp. PCC 6803 is a widely used model cyanobacterium for studying photosynthesis, phototaxis, the production of biofuels and many other aspects. Here we present a re-sequencing study of the genome and seven plasmids of one of the most widely used Synechocystis sp. PCC 6803 substrains, the glucose tolerant and motile Moscow or 'PCC-M' strain, revealing considerable evidence for recent microevolution. Seven single nucleotide polymorphisms (SNPs) specifically shared between 'PCC-M' and the 'PCC-N and PCC-P' substrains indicate that 'PCC-M' belongs to the 'PCC' group of motile strains. The identified indels and SNPs in 'PCC-M' are likely to affect glucose tolerance, motility, phage resistance, certain stress responses as well as functions in the primary metabolism, potentially relevant for the synthesis of alkanes. Three SNPs in intergenic regions could affect the promoter activities of two protein-coding genes and one cis-antisense RNA. Two deletions in 'PCC-M' affect parts of clustered regularly interspaced short palindrome repeats-associated spacer-repeat regions on plasmid pSYSA, in one case by an unusual recombination between spacer sequences.

  10. A bioelectrochemical approach to characterize extracellular electron transfer by Synechocystis sp. PCC6803.

    Directory of Open Access Journals (Sweden)

    Angelo Cereda

    Full Text Available Biophotovoltaic devices employ photosynthetic organisms at the anode of a microbial fuel cell to generate electrical power. Although a range of cyanobacteria and algae have been shown to generate photocurrent in devices of a multitude of architectures, mechanistic understanding of extracellular electron transfer by phototrophs remains minimal. Here we describe a mediatorless bioelectrochemical device to measure the electrogenic output of a planktonically grown cyanobacterium, Synechocystis sp. PCC6803. Light dependent production of current is measured, and its magnitude is shown to scale with microbial cell concentration and light intensity. Bioelectrochemical characterization of a Synechocystis mutant lacking Photosystem II demonstrates conclusively that production of the majority of photocurrent requires a functional water splitting aparatus and electrons are likely ultimately derived from water. This shows the potential of the device to rapidly and quantitatively characterize photocurrent production by genetically modified strains, an approach that can be used in future studies to delineate the mechanisms of cyanobacterial extracellular electron transport.

  11. Biochemical analysis of three putative KaiC clock proteins from Synechocystis sp. PCC 6803 suggests their functional divergence.

    Science.gov (United States)

    Wiegard, Anika; Dörrich, Anja K; Deinzer, Hans-Tobias; Beck, Christian; Wilde, Annegret; Holtzendorff, Julia; Axmann, Ilka M

    2013-05-01

    Cyanobacteria have been shown to have a circadian clock system that consists mainly of three protein components: KaiA, KaiB and KaiC. This system is well understood in the cyanobacterium Synechococcus elongatus PCC 7942, for which robust circadian oscillations have been shown. Like many other cyanobacteria, the chromosome of the model cyanobacterium Synechocystis sp. PCC 6803 contains additional kaiC and kaiB gene copies besides the standard kaiABC gene cluster. The respective gene products differ significantly in their amino acid sequences, especially in their C-terminal regions, suggesting different functional characteristics. Here, phosphorylation assays of the three Synechocystis sp. PCC 6803 KaiC proteins revealed that KaiC1 phosphorylation depends on KaiA, as is well documented for the Synechococcus elongatus PCC 7942 KaiC protein, whereas KaiC2 and KaiC3 autophosphorylate independently of KaiA. This was confirmed by in vivo protein-protein interaction studies, which demonstrate that only KaiC1 interacts with KaiA. Furthermore, we demonstrate that the three different Kai proteins form only homomeric complexes in vivo. As only KaiC1 phosphorylation depends on KaiA, a prerequisite for robust oscillations, we suggest that the kaiAB1C1 gene cluster in Synechocystis sp. PCC 6803 controls circadian timing in a manner similar to the clock described in Synechococcus elongatus PCC 7942.

  12. Improved sugar-free succinate production by Synechocystis sp. PCC 6803 following identification of the limiting steps in glycogen catabolism

    Directory of Open Access Journals (Sweden)

    Tomohisa Hasunuma

    2016-12-01

    Full Text Available Succinate produced by microorganisms can replace currently used petroleum-based succinate but typically requires mono- or poly-saccharides as a feedstock. The cyanobacterium Synechocystis sp. PCC6803 can produce organic acids such as succinate from CO2 not supplemented with sugars under dark anoxic conditions using an unknown metabolic pathway. The TCA cycle in cyanobacteria branches into oxidative and reductive routes. Time-course analyses of the metabolome, transcriptome and metabolic turnover described here revealed dynamic changes in the metabolism of Synechocystis sp. PCC6803 cultivated under dark anoxic conditions, allowing identification of the carbon flow and rate-limiting steps in glycogen catabolism. Glycogen biosynthesized from CO2 assimilated during periods of light exposure is catabolized to succinate via glycolysis, the anaplerotic pathway, and the reductive TCA cycle under dark anoxic conditions. Expression of the phosphoenolpyruvate (PEP carboxylase gene (ppc was identified as a rate-limiting step in succinate biosynthesis and this rate limitation was alleviated by ppc overexpression, resulting in improved succinate excretion. The sugar-free succinate production was further enhanced by the addition of bicarbonate. In vivo labeling with NaH13CO3 clearly showed carbon incorporation into succinate via the anaplerotic pathway. Bicarbonate is in equilibrium with CO2. Succinate production by Synechocystis sp. PCC6803 therefore holds significant promise for CO2 capture and utilization. Keywords: Autofermentation, Cyanobacteria, Dynamic metabolic profiling, Metabolomics, Succinate, Synechocystis

  13. FLAVODIIRON2 and FLAVODIIRON4 proteins mediate an oxygen-dependent alternative electron flow in Synechocystis sp. PCC 6803 under CO2-limited conditions.

    Science.gov (United States)

    Shimakawa, Ginga; Shaku, Keiichiro; Nishi, Akiko; Hayashi, Ryosuke; Yamamoto, Hiroshi; Sakamoto, Katsuhiko; Makino, Amane; Miyake, Chikahiro

    2015-02-01

    This study aims to elucidate the molecular mechanism of an alternative electron flow (AEF) functioning under suppressed (CO2-limited) photosynthesis in the cyanobacterium Synechocystis sp. PCC 6803. Photosynthetic linear electron flow, evaluated as the quantum yield of photosystem II [Y(II)], reaches a maximum shortly after the onset of actinic illumination. Thereafter, Y(II) transiently decreases concomitantly with a decrease in the photosynthetic oxygen evolution rate and then recovers to a rate that is close to the initial maximum. These results show that CO2 limitation suppresses photosynthesis and induces AEF. In contrast to the wild type, Synechocystis sp. PCC 6803 mutants deficient in the genes encoding FLAVODIIRON2 (FLV2) and FLV4 proteins show no recovery of Y(II) after prolonged illumination. However, Synechocystis sp. PCC 6803 mutants deficient in genes encoding proteins functioning in photorespiration show AEF activity similar to the wild type. In contrast to Synechocystis sp. PCC 6803, the cyanobacterium Synechococcus elongatus PCC 7942 has no FLV proteins with high homology to FLV2 and FLV4 in Synechocystis sp. PCC 6803. This lack of FLV2/4 may explain why AEF is not induced under CO2-limited photosynthesis in S. elongatus PCC 7942. As the glutathione S-transferase fusion protein overexpressed in Escherichia coli exhibits NADH-dependent oxygen reduction to water, we suggest that FLV2 and FLV4 mediate oxygen-dependent AEF in Synechocystis sp. PCC 6803 when electron acceptors such as CO2 are not available. © 2015 American Society of Plant Biologists. All Rights Reserved.

  14. Forced symbiosis between Synechocystis spp. PCC 6803 and apo-symbiotic Paramecium bursaria as an experimental model for evolutionary emergence of primitive photosynthetic eukaryotes.

    Science.gov (United States)

    Ohkawa, Hiroshi; Hashimoto, Naoko; Furukawa, Shunsuke; Kadono, Takashi; Kawano, Tomonori

    2011-06-01

    Single-cell green paramecia (Paramecium bursaria) is a swimming vehicle that carries several hundred cells of endo-symbiotic green algae. Here, a novel model for endo-symbiosis, prepared by introducing and maintaining the cells of cyanobacterium (Synechocystis spp. PCC 6803) in the apo-symbiotic cells of P. bursaria is described.

  15. Two essential FtsH proteases control the level of the Fur repressor during iron deficiency in the cyanobacterium Synechocystis sp. PCC 6803

    Czech Academy of Sciences Publication Activity Database

    Krynická, Vendula; Tichý, Martin; Krafl, Jaroslav; Jianfeng, Y.; Kaňa, Radek; Boehm, M.; Nixon, P. J.; Komenda, Josef

    2014-01-01

    Roč. 94, č. 3 (2014), s. 609-624 ISSN 0950-382X R&D Projects: GA MŠk ED2.1.00/03.0110; GA ČR GBP501/12/G055 Institutional support: RVO:61388971 Keywords : Synechocystis sp. * FtsH proteases * cyanobacterium * iron deficiency Subject RIV: EE - Microbiology, Virology Impact factor: 4.419, year: 2014

  16. The effect of enhanced acetate influx on Synechocystis sp. PCC 6803 metabolism.

    Science.gov (United States)

    Thiel, Kati; Vuorio, Eerika; Aro, Eva-Mari; Kallio, Pauli Tapio

    2017-02-02

    Acetate is a common microbial fermentative end-product, which can potentially be used as a supplementary carbon source to enhance the output of biotechnological production systems. This study focuses on the acetate metabolism of the photosynthetic cyanobacterium Synechocystis sp. PCC 6803 which is unable to grow on acetate as a sole carbon source but still can assimilate it via acetyl-CoA-derived metabolic intermediates. In order to gain insight into the acetate uptake, associated limitations and metabolic effects, a heterologous acetate transporter ActP from Escherichia coli was introduced into Synechocystis to facilitate the transport of supplemented acetate from the medium into the cell. The results show that enhanced acetate intake can efficiently promote the growth of the cyanobacterial host. The effect is apparent specifically under low-light conditions when the photosynthetic activity is low, and expected to result from increased availability of acetyl-CoA precursors, accompanied by changes induced in cellular glycogen metabolism which may include allocation of resources towards enhanced growth instead of glycogen accumulation. Despite the stimulated growth of the mutant, acetate is shown to suppress the activity of the photosynthetic apparatus, further emphasizing the contribution of glycolytic metabolism in the acetate-induced effect. The use of acetate by the cyanobacterium Synechocystis sp. PCC 6803 is at least partially restricted by the import into the cell. This can be improved by the introduction of a heterologous acetate transporter into the system, thereby providing a potential advantage by expanding the scope of acetate utilization for various biosynthetic processes.

  17. Bioinformatic evaluation of L-arginine catabolic pathways in 24 cyanobacteria and transcriptional analysis of genes encoding enzymes of L-arginine catabolism in the cyanobacterium Synechocystis sp. PCC 6803

    OpenAIRE

    Schriek, Sarah; R?ckert, Christian; Staiger, Dorothee; Pistorius, Elfriede K; Michel, Klaus-Peter

    2007-01-01

    Abstract Background So far very limited knowledge exists on L-arginine catabolism in cyanobacteria, although six major L-arginine-degrading pathways have been described for prokaryotes. Thus, we have performed a bioinformatic analysis of possible L-arginine-degrading pathways in cyanobacteria. Further, we chose Synechocystis sp. PCC 6803 for a more detailed bioinformatic analysis and for validation of the bioinformatic predictions on L-arginine catabolism with a transcript analysis. Results W...

  18. The Psb27 Assembly Factor Binds to the CP43 Complex of Photosystem II in the Cyanobacterium Synechocystis sp PCC 6803

    Czech Academy of Sciences Publication Activity Database

    Komenda, Josef; Knoppová, Jana; Kopečná, Jana; Sobotka, Roman; Halada, Petr; Yu, J.; Nickelsen, J.; Boehm, M.; Nixon, P. J.

    2012-01-01

    Roč. 158, č. 1 (2012), s. 476-486 ISSN 0032-0889 R&D Projects: GA ČR(CZ) GAP501/11/0377; GA ČR GAP501/10/1000; GA MŠk LC07017 Institutional research plan: CEZ:AV0Z50200510 Keywords : MEMBRANE-PROTEIN COMPLEXES * SP PCC-6803 * D1 PROTEIN Subject RIV: EE - Microbiology, Virology Impact factor: 6.555, year: 2012

  19. The antisense RNA As1_flv4 in the Cyanobacterium Synechocystis sp. PCC 6803 prevents premature expression of the flv4-2 operon upon shift in inorganic carbon supply.

    Science.gov (United States)

    Eisenhut, Marion; Georg, Jens; Klähn, Stephan; Sakurai, Isamu; Mustila, Henna; Zhang, Pengpeng; Hess, Wolfgang R; Aro, Eva-Mari

    2012-09-28

    The functional relevance of natural cis-antisense transcripts is mostly unknown. Here we have characterized the association of three antisense RNAs and one intergenically encoded noncoding RNA with an operon that plays a crucial role in photoprotection of photosystem II under low carbon conditions in the cyanobacterium Synechocystis sp. PCC 6803. Cyanobacteria show strong gene expression dynamics in response to a shift of cells from high carbon to low levels of inorganic carbon (C(i)), but the regulatory mechanisms are poorly understood. Among the most up-regulated genes in Synechocystis are flv4, sll0218, and flv2, which are organized in the flv4-2 operon. The flavodiiron proteins encoded by this operon open up an alternative electron transfer route, likely starting from the Q(B) site in photosystem II, under photooxidative stress conditions. Our expression analysis of cells shifted from high carbon to low carbon demonstrated an inversely correlated transcript accumulation of the flv4-2 operon mRNA and one antisense RNA to flv4, designated as As1_flv4. Overexpression of As1_flv4 led to a decrease in flv4-2 mRNA. The promoter activity of as1_flv4 was transiently stimulated by C(i) limitation and negatively regulated by the AbrB-like transcription regulator Sll0822, whereas the flv4-2 operon was positively regulated by the transcription factor NdhR. The results indicate that the tightly regulated antisense RNA As1_flv4 establishes a transient threshold for flv4-2 expression in the early phase after a change in C(i) conditions. Thus, it prevents unfavorable synthesis of the proteins from the flv4-2 operon.

  20. The Antisense RNA As1_flv4 in the Cyanobacterium Synechocystis sp. PCC 6803 Prevents Premature Expression of the flv4-2 Operon upon Shift in Inorganic Carbon Supply*

    Science.gov (United States)

    Eisenhut, Marion; Georg, Jens; Klähn, Stephan; Sakurai, Isamu; Mustila, Henna; Zhang, Pengpeng; Hess, Wolfgang R.; Aro, Eva-Mari

    2012-01-01

    The functional relevance of natural cis-antisense transcripts is mostly unknown. Here we have characterized the association of three antisense RNAs and one intergenically encoded noncoding RNA with an operon that plays a crucial role in photoprotection of photosystem II under low carbon conditions in the cyanobacterium Synechocystis sp. PCC 6803. Cyanobacteria show strong gene expression dynamics in response to a shift of cells from high carbon to low levels of inorganic carbon (Ci), but the regulatory mechanisms are poorly understood. Among the most up-regulated genes in Synechocystis are flv4, sll0218, and flv2, which are organized in the flv4-2 operon. The flavodiiron proteins encoded by this operon open up an alternative electron transfer route, likely starting from the QB site in photosystem II, under photooxidative stress conditions. Our expression analysis of cells shifted from high carbon to low carbon demonstrated an inversely correlated transcript accumulation of the flv4-2 operon mRNA and one antisense RNA to flv4, designated as As1_flv4. Overexpression of As1_flv4 led to a decrease in flv4-2 mRNA. The promoter activity of as1_flv4 was transiently stimulated by Ci limitation and negatively regulated by the AbrB-like transcription regulator Sll0822, whereas the flv4-2 operon was positively regulated by the transcription factor NdhR. The results indicate that the tightly regulated antisense RNA As1_flv4 establishes a transient threshold for flv4-2 expression in the early phase after a change in Ci conditions. Thus, it prevents unfavorable synthesis of the proteins from the flv4-2 operon. PMID:22854963

  1. Synechocystis PCC 6803 overexpressing RuBisCO grow faster with increased photosynthesis

    Directory of Open Access Journals (Sweden)

    Feiyan Liang

    2017-06-01

    Full Text Available The ribulose-1,5-bisphosphate (RuBP oxygenation reaction catalyzed by Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO is competing with carboxylation, being negative for both energy and carbon balances in photoautotrophic organisms. This makes RuBisCO one of the bottlenecks for oxygenic photosynthesis and carbon fixation. In this study, RuBisCO was overexpressed in the unicellular cyanobacterium Synechocystis PCC 6803. Relative RuBisCO levels in the engineered strains FL50 and FL52 increased 2.1 times and 1.4 times, respectively, and both strains showed increased growth, photosynthesis and in vitro RuBisCO activity. The oxygen evolution rate increased by 54% and 42% on per chlorophyll basis, while the in vitro RuBisCO activity increased by 52% and 8.6%, respectively. The overexpressed RuBisCO were tagged with a FLAG tag, in strain FL50 on the N terminus of the large subunit while in strain FL52 on the C terminus of the small subunit. The presence of a FLAG tag enhanced transcription of the genes encoding RuBisCO, and, with high possibility, also enhanced the initiation of translation or stability of the enzyme. However, when using a streptavidin-binding tag II (strep-tag II, we did not observe a similar effect. Tagged RuBisCO offers an opportunity for further studying RuBisCO expression and stability. Increased levels of RuBisCO can further improve photosynthesis and growth in the cyanobacterium Synechocystis PCC 6803 under certain growth conditions.

  2. Phenotypic characterization of Synechocystis sp. PCC 6803 substrains reveals differences in sensitivity to abiotic stress.

    Directory of Open Access Journals (Sweden)

    Tomáš Zavřel

    Full Text Available Synechocystis sp. PCC 6803 is a widely used model cyanobacterium, whose substrains can vary on both genotype and phenotype levels. Previously described phenotypic variations include ability of mixotrophic growth, ability of movement on agar plates and variations in pigments composition or cell size. In this study, we report for the first time significant variation among Synechocystis substrains in complex cellular traits such as growth rate, photosynthesis efficiency, cellular dry weight and cellular composition (including protein or carbohydrates content. We also confirmed previously reported differences in cell size. Synechocystis cultures were cultivated in controlled environment of flat panel photobioreactors under red, blue and white light of intensities up to 790 μmol(photons m-2 s-1, temperatures 23°C-60°C, input CO2 concentrations ranging from 400 to 15 000 ppm and in BG11 cultivation medium with and without addition of NaCl. Three Synechocystis substrains were used for the comparative experiments: GT-L, GT-B (Brno, CZ and PCC-B (Brno, CZ. Growth rates of Synechocystis GT-B were inhibited under high intensities of red light (585-670 nm, and growth rates of both substrains GT-B and PCC-B were inhibited under photons of wavelengths 485-585 nm and 670-700 nm. Synechocystis GT-B was more sensitive to low temperatures than the other two tested substrains, and Synechocystis GT-L was sensitive to the presence of NaCl in the cultivation media. The results suggest that stress sensitivity of commonly used Synechocystis substrains can strongly vary, similarly as glucose tolerance or motility as reported previously. Our study further supports the previous statement that emphasizes importance of proper Synechocystis substrains selection and awareness of phenotypical differences among Synechocystis substrains which is crucial for comparative and reproducible research. This is highly relevant for studies related to stress physiology and development

  3. Phenotypic characterization of Synechocystis sp. PCC 6803 substrains reveals differences in sensitivity to abiotic stress.

    Science.gov (United States)

    Zavřel, Tomáš; Očenášová, Petra; Červený, Jan

    2017-01-01

    Synechocystis sp. PCC 6803 is a widely used model cyanobacterium, whose substrains can vary on both genotype and phenotype levels. Previously described phenotypic variations include ability of mixotrophic growth, ability of movement on agar plates and variations in pigments composition or cell size. In this study, we report for the first time significant variation among Synechocystis substrains in complex cellular traits such as growth rate, photosynthesis efficiency, cellular dry weight and cellular composition (including protein or carbohydrates content). We also confirmed previously reported differences in cell size. Synechocystis cultures were cultivated in controlled environment of flat panel photobioreactors under red, blue and white light of intensities up to 790 μmol(photons) m-2 s-1, temperatures 23°C-60°C, input CO2 concentrations ranging from 400 to 15 000 ppm and in BG11 cultivation medium with and without addition of NaCl. Three Synechocystis substrains were used for the comparative experiments: GT-L, GT-B (Brno, CZ) and PCC-B (Brno, CZ). Growth rates of Synechocystis GT-B were inhibited under high intensities of red light (585-670 nm), and growth rates of both substrains GT-B and PCC-B were inhibited under photons of wavelengths 485-585 nm and 670-700 nm. Synechocystis GT-B was more sensitive to low temperatures than the other two tested substrains, and Synechocystis GT-L was sensitive to the presence of NaCl in the cultivation media. The results suggest that stress sensitivity of commonly used Synechocystis substrains can strongly vary, similarly as glucose tolerance or motility as reported previously. Our study further supports the previous statement that emphasizes importance of proper Synechocystis substrains selection and awareness of phenotypical differences among Synechocystis substrains which is crucial for comparative and reproducible research. This is highly relevant for studies related to stress physiology and development of sustainable

  4. Rubisco mutagenesis provides new insight into limitations on photosynthesis and growth in Synechocystis PCC6803

    Science.gov (United States)

    Marcus, Yehouda; Altman-Gueta, Hagit; Wolff, Yael; Gurevitz, Michael

    2011-01-01

    Orthophosphate (Pi) stimulates the activation of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) while paradoxically inhibiting its catalysis. Of three Pi-binding sites, the roles of the 5P- and latch sites have been documented, whereas that of the 1P-site remained unclear. Conserved residues at the 1P-site of Rubisco from the cyanobacterium Synechocystis PCC6803 were substituted and the kinetic properties of the enzyme derivatives and effects on cell photosynthesis and growth were examined. While Pi-stimulated Rubisco activation diminished for enzyme mutants T65A/S and G404A, inhibition of catalysis by Pi remained unchanged. Together with previous studies, the results suggest that all three Pi-binding sites are involved in stimulation of Rubisco activation, whereas only the 5P-site is involved in inhibition of catalysis. While all the mutations reduced the catalytic turnover of Rubisco (Kcat) between 6- and 20-fold, the photosynthesis and growth rates under saturating irradiance and inorganic carbon (Ci) concentrations were only reduced 40–50% (in the T65A/S mutants) or not at all (G404A mutant). Analysis of the mutant cells revealed a 3-fold increase in Rubisco content that partially compensated for the reduced Kcat so that the carboxylation rate per chlorophyll was one-third of that in the wild type. Correlation between the kinetic properties of Rubisco and the photosynthetic rate (Pmax) under saturating irradiance and Ci concentrations indicate that a >60% reduction in Kcat can be tolerated before Pmax in Synechocystsis PCC6803 is affected. These results indicate that the limitation of Rubisco activity on the rate of photosynthesis in Synechocystis is low. Determination of Calvin cycle metabolites revealed that unlike in higher plants, cyanobacterial photosynthesis is constrained by phosphoglycerate reduction probably due to limitation of ATP or NADPH. PMID:21551078

  5. Genome-wide responses of Synechocystis PCC6803 to nitrogen deprivation

    NARCIS (Netherlands)

    Krasikov, V.; Aguirre von Wobeser, E.; Huisman, J.; Ibelings, B; Matthijs, H.C.P.; Matthijs, H. C. P.

    2005-01-01

    Genome-wide responses of Synechocystis PCC6803 to nitrogen deprivation Vladimir Krasikov1, Eneas Aguirre-von-Wobeser1, Jef Huisman1, Bas Ibelings2, Hans C.P. Matthijs1 1Universiteit van Amsterdam, Amsterdam, the Netherlands; 2Netherlands Institute of Ecology, Limnological Institute, Nieuwersluis,

  6. Phenotypic characterization of Synechocystis sp PCC 6803 substrains reveals differences in sensitivity to abiotic stress

    Czech Academy of Sciences Publication Activity Database

    Zavřel, Tomáš; Očenášová, Petra; Červený, Jan

    2017-01-01

    Roč. 12, č. 12 (2017), č. článku e0189130. E-ISSN 1932-6203 R&D Projects: GA MŠk(CZ) LO1415; GA ČR(CZ) GA15-17367S; GA ČR(CZ) GA15-17367S Institutional support: RVO:86652079 Keywords : sp strain pcc-6803 * high-temperature * sp pcc6803 * cyanobacterium * growth * responses * acclimation * gene * photobioreactor * identification Subject RIV: EI - Biotechnology ; Bionics OBOR OECD: Environmental biotechnology Impact factor: 2.806, year: 2016

  7. Daily expression pattern of protein-encoding genes and small noncoding RNAs in synechocystis sp. strain PCC 6803.

    Science.gov (United States)

    Beck, Christian; Hertel, Stefanie; Rediger, Anne; Lehmann, Robert; Wiegard, Anika; Kölsch, Adrian; Heilmann, Beate; Georg, Jens; Hess, Wolfgang R; Axmann, Ilka M

    2014-09-01

    Many organisms harbor circadian clocks with periods close to 24 h. These cellular clocks allow organisms to anticipate the environmental cycles of day and night by synchronizing circadian rhythms with the rising and setting of the sun. These rhythms originate from the oscillator components of circadian clocks and control global gene expression and various cellular processes. The oscillator of photosynthetic cyanobacteria is composed of three proteins, KaiA, KaiB, and KaiC, linked to a complex regulatory network. Synechocystis sp. strain PCC 6803 possesses the standard cyanobacterial kaiABC gene cluster plus multiple kaiB and kaiC gene copies and antisense RNAs for almost every kai transcript. However, there is no clear evidence of circadian rhythms in Synechocystis sp. PCC 6803 under various experimental conditions. It is also still unknown if and to what extent the multiple kai gene copies and kai antisense RNAs affect circadian timing. Moreover, a large number of small noncoding RNAs whose accumulation dynamics over time have not yet been monitored are known for Synechocystis sp. PCC 6803. Here we performed a 48-h time series transcriptome analysis of Synechocystis sp. PCC 6803, taking into account periodic light-dark phases, continuous light, and continuous darkness. We found that expression of functionally related genes occurred in different phases of day and night. Moreover, we found day-peaking and night-peaking transcripts among the small RNAs; in particular, the amounts of kai antisense RNAs correlated or anticorrelated with those of their respective kai target mRNAs, pointing toward the regulatory relevance of these antisense RNAs. Surprisingly, we observed that the amounts of 16S and 23S rRNAs in this cyanobacterium fluctuated in light-dark periods, showing maximum accumulation in the dark phase. Importantly, the amounts of all transcripts, including small noncoding RNAs, did not show any rhythm under continuous light or darkness, indicating the absence

  8. The gamma-aminobutyric acid shunt contributes to closing the tricarboxylic acid cycle in Synechocystis sp PCC 6803

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, W; Brune, D; Vermaas, WFJ

    2014-07-16

    A traditional 2-oxoglutarate dehydrogenase complex is missing in the cyanobacterial tricarboxylic acid cycle. To determine pathways that convert 2-oxoglutarate into succinate in the cyanobacterium Synechocystis sp. PCC 6803, a series of mutant strains, Delta sll1981, Delta slr0370, Delta slr1022 and combinations thereof, deficient in 2-oxoglutarate decarboxylase (Sll1981), succinate semialdehyde dehydrogenase (Slr0370), and/or in gamma-aminobutyrate metabolism (Slr1022) were constructed. Like in Pseudomonas aeruginosa, N-acetylornithine aminotransferase, encoded by slr1022, was shown to also function as gamma-aminobutyrate aminotransferase, catalysing gamma-aminobutyrate conversion to succinic semialdehyde. As succinic semialdehyde dehydrogenase converts succinic semialdehyde to succinate, an intact gamma-aminobutyrate shunt is present in Synechocystis. The Delta sll1981 strain, lacking 2-oxoglutarate decarboxylase, exhibited a succinate level that was 60% of that in wild type. However, the succinate level in the Delta slr1022 and Delta slr0370 strains and the Delta sll1981/Delta slr1022 and Delta sll1981/Delta slr0370 double mutants was reduced to 20-40% of that in wild type, suggesting that the gamma-aminobutyrate shunt has a larger impact on metabolite flux to succinate than the pathway via 2-oxoglutarate decarboxylase. C-13-stable isotope analysis indicated that the gamma-aminobutyrate shunt catalysed conversion of glutamate to succinate. Independent of the 2-oxoglutarate decarboxylase bypass, the gamma-aminobutyrate shunt is a major contributor to flux from 2-oxoglutarate and glutamate to succinate in Synechocystis sp. PCC 6803.

  9. Synthesis of chlorophyll-binding proteins in a fully-segregated ∆ycf54 strain of the cyanobacterium Synechocystis PCC 6803

    Directory of Open Access Journals (Sweden)

    Sarah eHollingshead

    2016-03-01

    Full Text Available In the chlorophyll (Chl biosynthesis pathway the formation of protochlorophyllide is catalyzed by Mg-protoporphyrin IX methyl ester (MgPME cyclase. The Ycf54 protein was recently shown to form a complex with another component of the oxidative cyclase, Sll1214 (CycI, and partial inactivation of the ycf54 gene leads to Chl deficiency in cyanobacteria and plants. The exact function of the Ycf54 is not known, however, and further progress depends on construction and characterisation of a mutant cyanobacterial strain with a fully inactivated ycf54 gene. Here, we report the complete deletion of the ycf54 gene in the cyanobacterium Synechocystis 6803; the resulting ycf54 strain accumulates huge concentrations of the cyclase substrate MgPME together with another pigment, which we identified using nuclear magnetic resonance as 3-formyl MgPME. The detection of a small amount (~13% of Chl in the ycf54 mutant provides clear evidence that the Ycf54 protein is important, but not essential, for activity of the oxidative cyclase. The greatly reduced formation of protochlorophyllide in the ycf54 strain provided an opportunity to use 35S protein labelling combined with 2D electrophoresis to examine the synthesis of all known Chl-binding protein complexes under drastically restricted de novo Chl biosynthesis. We show that although the ycf54 strain synthesizes very limited amounts of photosystem I and the CP47 and CP43 subunits of photosystem II (PSII, the synthesis of PSII D1 and D2 subunits and their assembly into the reaction centre (RCII assembly intermediate were not affected. Furthermore, the levels of other Chl complexes such as cytochrome b6f and the HliD– Chl synthase remained comparable to wild-type. These data demonstrate that the requirement for de novo Chl molecules differs completely for each Chl-binding protein. Chl traffic and recycling in the cyanobacterial cell as well as the function of Ycf54 are discussed.

  10. Physical, chemical, and metabolic state sensors expand the synthetic biology toolbox for Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Immethun, Cheryl M; DeLorenzo, Drew M; Focht, Caroline M; Gupta, Dinesh; Johnson, Charles B; Moon, Tae Seok

    2017-07-01

    Many under-developed organisms possess important traits that can boost the effectiveness and sustainability of microbial biotechnology. Photoautotrophic cyanobacteria can utilize the energy captured from light to fix carbon dioxide for their metabolic needs while living in environments not suited for growing crops. Various value-added compounds have been produced by cyanobacteria in the laboratory; yet, the products' titers and yields are often not industrially relevant and lag behind what have been accomplished in heterotrophic microbes. Genetic tools for biological process control are needed to take advantage of cyanobacteria's beneficial qualities, as tool development also lags behind what has been created in common heterotrophic hosts. To address this problem, we developed a suite of sensors that regulate transcription in the model cyanobacterium Synechocystis sp. PCC 6803 in response to metabolically relevant signals, including light and the cell's nitrogen status, and a family of sensors that respond to the inexpensive chemical, l-arabinose. Increasing the number of available tools enables more complex and precise control of gene expression. Expanding the synthetic biology toolbox for this cyanobacterium also improves our ability to utilize this important under-developed organism in biotechnology. Biotechnol. Bioeng. 2017;114: 1561-1569. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  11. Mutational analysis of photosystem I polypeptides in the cyanobacterium Synechocystis sp. PCC 6803. Targeted inactivation of psaI reveals the function of psaI in the structural organization of psaL

    Science.gov (United States)

    Xu, Q.; Hoppe, D.; Chitnis, V. P.; Odom, W. R.; Guikema, J. A.; Chitnis, P. R.; Spooner, B. S. (Principal Investigator)

    1995-01-01

    We cloned, characterized, and inactivated the psaI gene encoding a 4-kDa hydrophobic subunit of photosystem I from the cyanobacterium Synechocystis sp. PCC 6803. The psaI gene is located 90 base pairs downstream from psaL, and is transcribed on 0.94- and 0.32-kilobase transcripts. To identify the function of PsaI, we generated a cyanobacterial strain in which psaI has been interrupted by a gene for chloramphenicol resistance. The wild-type and the mutant cells showed comparable rates of photoautotrophic growth at 25 degrees C. However, the mutant cells grew slower and contained less chlorophyll than the wild-type cells, when grown at 40 degrees C. The PsaI-less membranes from cells grown at either temperature showed a small decrease in NADP+ photoreduction rate when compared to the wild-type membranes. Inactivation of psaI led to an 80% decrease in the PsaL level in the photosynthetic membranes and to a complete loss of PsaL in the purified photosystem I preparations, but had little effect on the accumulation of other photosystem I subunits. Upon solubilization with nonionic detergents, photosystem I trimers could be obtained from the wild-type, but not from the PsaI-less membranes. The PsaI-less photosystem I monomers did not contain detectable levels of PsaL. Therefore, a structural interaction between PsaL and PsaI may stabilize the association of PsaL with the photosystem I core. PsaL in the wild-type and PsaI-less membranes showed equal resistance to removal by chaotropic agents. However, PsaL in the PsaI-less strain exhibited an increased susceptibility to proteolysis. From these data, we conclude that PsaI has a crucial role in aiding normal structural organization of PsaL within the photosystem I complex and the absence of PsaI alters PsaL organization, leading to a small, but physiologically significant, defect in photosystem I function.

  12. A role of the C-terminal extension of the Photosystem II D1 protein in sensitivity of the cyanobacterium Synechocystis PCC 6803 to photoinhibition

    Czech Academy of Sciences Publication Activity Database

    Kuviková, Stanislava; Tichý, Martin; Komenda, Josef

    2005-01-01

    Roč. 4, - (2005), s. 1044-1048 ISSN 1474-905X Institutional research plan: CEZ:AV0Z50200510 Keywords : c-terminal * synechocystis * photosystem II Subject RIV: EE - Microbiology, Virology Impact factor: 2.117, year: 2005

  13. Open reading frame ssr2016 is required for antimycin A-sensitive photosystem I-driven cyclic electron flow in the cyanobacterium Synechocystis sp. PCC 6803

    NARCIS (Netherlands)

    Yeremenko, Nataliya; Jeanjean, Robert; Prommeenate, Peerada; Krasikov, Vladimir; Nixon, Peter J.; Vermaas, Wim F. J.; Havaux, Michel; Matthijs, Hans C. P.

    2005-01-01

    Open reading frame ssr2016 encodes a protein with substantial sequence similarities to PGR5 identified as a component of the antimycin A-sensitive ferredoxin:plastoquinone reductase (FQR) in PSI cyclic photophosphorylation in Arabidopsis thaliana. We studied cyclic electron flow in Synechocystis sp.

  14. Potential of Synechocystis PCC 6803 as a novel cyanobacterial chassis for heterologous expression of enzymes in the trans-resveratrol biosynthetic pathway.

    Science.gov (United States)

    Tantong, Supaluk; Incharoensakdi, Aran; Sirikantaramas, Supaart; Lindblad, Peter

    2016-05-01

    Selected model strains of phototrophic cyanobacteria have been genetically engineered for heterologous expression of numerous enzymes. In the present study, we initially explored the heterologous expression of enzymes involved in trans-resveratrol production, namely, the production of tyrosine ammonia-lyase, coumaroyl CoA-ligase, and stilbene synthase, in the unicellular cyanobacterium Synechocystis PCC 6803. Under the promoters Ptrc1Ocore and Ptrc1O, the respective genes were transcribed and translated into the corresponding soluble proteins at concentrations of 16-34 μg L(-1). The expression levels of these enzymes did not affect the growth rate of the cyanobacterial cells. Interestingly, coumaroyl CoA-ligase expression slightly increased the chlorophyll a content of the cells. Overall, our results suggest that the complete pathway of trans-resveratrol production can be engineered in Synechocystis PCC 6803. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. The Synechocystis sp. PCC6803 Sfp-type phosphopantetheinyl transferase does not possess characteristic broad-range activity.

    Science.gov (United States)

    Roberts, Alexandra A; Copp, Janine N; Marahiel, Mohamed A; Neilan, Brett A

    2009-07-20

    The cyanobacterium Synechocystis sp. PCC6803 harbours one phosphopantetheinyl transferase (PPTase), Sppt. Protein modelling supported previous bioinformatics analyses, which suggested that Sppt is a Sfp-type PPTase with the potential to phosphopantetheinylate a broad range of carrier proteins from both primary and secondary metabolism. However, no natural products are synthesised by this species, which raises interesting evolutionary and functional questions. Phosphopantetheinylation assays and kinetic data demonstrate that Sppt was able to activate its cognate fatty acid synthesis carrier protein, SACP, but was unable to effectively activate various cyanobacterial carrier proteins from secondary metabolism or glycolipid biosynthesis pathways. To our knowledge, this is the first example of a PPTase with a Sfp-type structure, but with activity more closely resembling AcpS-type enzymes. The broad-range PPTase from Nodularia spumigena NSOR10 was introduced into Synechocystis sp. PCC6803 and was shown to activate a noncognate carrier protein, in vivo. This engineered strain could provide a future biotechnological platform for the heterologous expression of cyanobacterial biosynthetic gene clusters.

  16. Metabolic Changes in Synechocystis PCC6803 upon Nitrogen-Starvation: Excess NADPH Sustains Polyhydroxybutyrate Accumulation

    Science.gov (United States)

    Hauf, Waldemar; Schlebusch, Maximilian; Hüge, Jan; Kopka, Joachim; Hagemann, Martin; Forchhammer, Karl

    2013-01-01

    Polyhydroxybutyrate (PHB) is a common carbon storage polymer among heterotrophic bacteria. It is also accumulated in some photoautotrophic cyanobacteria; however, the knowledge of how PHB accumulation is regulated in this group is limited. PHB synthesis in Synechocystis sp. PCC 6803 is initiated once macronutrients like phosphorus or nitrogen are limiting. We have previously reported a mutation in the gene sll0783 that impairs PHB accumulation in this cyanobacterium upon nitrogen starvation. In this study we present data which explain the observed phenotype. We investigated differences in intracellular localization of PHB synthase, metabolism, and the NADPH pool between wild type and mutant. Localization of PHB synthase was not impaired in the sll0783 mutant; however, metabolome analysis revealed a difference in sorbitol levels, indicating a more oxidizing intracellular environment than in the wild type. We confirmed this by directly measuring the NADPH/NADP ratio and by altering the intracellular redox state of wild type and sll0783 mutant. We were able to physiologically complement the mutant phenotype of diminished PHB synthase activity by making the intracellular environment more reducing. Our data illustrate that the NADPH pool is an important factor for regulation of PHB biosynthesis and metabolism, which is also of interest for potential biotechnological applications. PMID:24957892

  17. Metabolic Changes in Synechocystis PCC6803 upon Nitrogen-Starvation: Excess NADPH Sustains Polyhydroxybutyrate Accumulation

    Directory of Open Access Journals (Sweden)

    Waldemar Hauf

    2013-02-01

    Full Text Available Polyhydroxybutyrate (PHB is a common carbon storage polymer among heterotrophic bacteria. It is also accumulated in some photoautotrophic cyanobacteria; however, the knowledge of how PHB accumulation is regulated in this group is limited. PHB synthesis in Synechocystis sp. PCC 6803 is initiated once macronutrients like phosphorus or nitrogen are limiting. We have previously reported a mutation in the gene sll0783 that impairs PHB accumulation in this cyanobacterium upon nitrogen starvation. In this study we present data which explain the observed phenotype. We investigated differences in intracellular localization of PHB synthase, metabolism, and the NADPH pool between wild type and mutant. Localization of PHB synthase was not impaired in the sll0783 mutant; however, metabolome analysis revealed a difference in sorbitol levels, indicating a more oxidizing intracellular environment than in the wild type. We confirmed this by directly measuring the NADPH/NADP ratio and by altering the intracellular redox state of wild type and sll0783 mutant. We were able to physiologically complement the mutant phenotype of diminished PHB synthase activity by making the intracellular environment more reducing. Our data illustrate that the NADPH pool is an important factor for regulation of PHB biosynthesis and metabolism, which is also of interest for potential biotechnological applications.

  18. PfsR is a key regulator of iron homeostasis in Synechocystis PCC 6803.

    Directory of Open Access Journals (Sweden)

    Dan Cheng

    Full Text Available Iron is an essential cofactor in numerous cellular processes. The iron deficiency in the oceans affects the primary productivity of phytoplankton including cyanobacteria. In this study, we examined the function of PfsR, a TetR family transcriptional regulator, in iron homeostasis of the cyanobacterium Synechocystis PCC 6803. Compared with the wild type, the pfsR deletion mutant displayed stronger tolerance to iron limitation and accumulated significantly more chlorophyll a, carotenoid, and phycocyanin under iron-limiting conditions. The mutant also maintained more photosystem I and photosystem II complexes than the wild type after iron deprivation. In addition, the activities of photosystem I and photosystem II were much higher in pfsR deletion mutant than in wild-type cells under iron-limiting conditions. The transcripts of pfsR were enhanced by iron limitation and inactivation of the gene affected pronouncedly expression of fut genes (encoding a ferric iron transporter, feoB (encoding a ferrous iron transporter, bfr genes (encoding bacterioferritins, ho genes (encoding heme oxygenases, isiA (encoding a chlorophyll-binding protein, and furA (encoding a ferric uptake regulator. The iron quota in pfsR deletion mutant cells was higher than in wild-type cells both before and after exposure to iron limitation. Electrophoretic mobility shift assays showed that PfsR bound to its own promoter and thereby auto-regulated its own expression. These data suggest that PfsR is a critical regulator of iron homeostasis.

  19. Mechanisms of High Temperature Resistance of Synechocystis sp. PCC 6803: An Impact of Histidine Kinase 34

    Directory of Open Access Journals (Sweden)

    Jan Červený

    2015-03-01

    Full Text Available Synechocystis sp. PCC 6803 is a widely used model cyanobacterium for studying responses and acclimation to different abiotic stresses. Changes in transcriptome, proteome, lipidome, and photosynthesis in response to short term heat stress are well studied in this organism, and histidine kinase 34 (Hik34 is shown to play an important role in mediating such response. Corresponding data on long term responses, however, are fragmentary and vary depending on parameters of experiments and methods of data collection, and thus are hard to compare. In order to elucidate how the early stress responses help cells to sustain long-term heat stress, as well as the role of Hik34 in prolonged acclimation, we examined the resistance to long-term heat stress of wild-type and ΔHik34 mutant of Synechocystis. In this work, we were able to precisely control the long term experimental conditions by cultivating Synechocystis in automated photobioreactors, measuring selected physiological parameters within a time range of minutes. In addition, morphological and ultrastructural changes in cells were analyzed and western blotting of individual proteins was used to study the heat stress-affected protein expression. We have shown that the majority of wild type cell population was able to recover after 24 h of cultivation at 44 °C. In contrast, while ΔHik34 mutant cells were resistant to heat stress within its first hours, they could not recover after 24 h long high temperature treatment. We demonstrated that the early induction of HspA expression and maintenance of high amount of other HSPs throughout the heat incubation is critical for successful adaptation to long-term stress. In addition, it appears that histidine kinase Hik34 is an essential component for the long term high temperature resistance.

  20. Metabolic engineering of Synechocystis sp. PCC 6803 for enhanced ethanol production based on flux balance analysis.

    Science.gov (United States)

    Yoshikawa, Katsunori; Toya, Yoshihiro; Shimizu, Hiroshi

    2017-05-01

    Synechocystis sp. PCC 6803 is an attractive host for bio-ethanol production due to its ability to directly convert atmospheric carbon dioxide into ethanol using photosystems. To enhance ethanol production in Synechocystis sp. PCC 6803, metabolic engineering was performed based on in silico simulations, using the genome-scale metabolic model. Comprehensive reaction knockout simulations by flux balance analysis predicted that the knockout of NAD(P)H dehydrogenase enhanced ethanol production under photoautotrophic conditions, where ammonium is the nitrogen source. This deletion inhibits the re-oxidation of NAD(P)H, which is generated by ferredoxin-NADP + reductase and imposes re-oxidation in the ethanol synthesis pathway. The effect of deleting the ndhF1 gene, which encodes NADH dehydrogenase subunit 5, on ethanol production was experimentally evaluated using ethanol-producing strains of Synechocystis sp. PCC 6803. The ethanol titer of the ethanol-producing ∆ndhF1 strain increased by 145%, compared with that of the control strain.

  1. Photoautotrophic Production of Biomass, Laurate, and Soluble Organics by Synechocystis sp. PCC 6803

    Science.gov (United States)

    Nguyen, Binh Thanh

    Photosynthesis converts sunlight to biomass at a global scale. Among the photosynthetic organisms, cyanobacteria provide an excellent model to study how photosynthesis can become a practical platform of large-scale biotechnology. One novel approach involves metabolically engineering the cyanobacterium Synechocystis sp. PCC 6803 to excrete laurate, which is harvested directly. This work begins by defining a working window of light intensity (LI). Wild-type and laurate-excreting Synechocystis required an LI of at least 5 muE/m2-s to sustain themselves, but are photo-inhibited by LI of 346 to 598 muE/m2-s. Fixing electrons into valuable organic products, e.g., biomass and excreted laurate, is critical to success. Wild-type Synechocystis channeled 75% to 84% of its fixed electrons to biomass; laurate-excreting Synechocystis fixed 64 to 69% as biomass and 6.6% to 10% as laurate. This means that 16 to 30% of the electrons were diverted to non-valuable soluble products, and the trend was accentuated with higher LI. How the Ci concentration depended on the pH and the nitrogen source was quantified by the proton condition and experimentally validated. Nitrate increased, ammonium decreased, but ammonium nitrate stabilized alkalinity and Ci. This finding provides a mechanistically sound tool to manage Ci and pH independently. Independent evaluation pH and Ci on the growth kinetics of Synechocystis showed that pH 8.5 supported the fastest maximum specific growth rate (mumax): 2.4/day and 1.7/day, respectively, for the wild type and modified strains with LI of 202 muE/m2-s. Half-maximum-rate concentrations (KCi) were less than 0.1 mM, meaning that Synechocystis should attain its mumax with a modest Ci concentration (≥1.0 mM). Biomass grown with day-night cycles had a night endogenous decay rate of 0.05-1.0/day, with decay being faster with higher LI and the beginning of dark periods. Supplying light at a fraction of daylight reduced dark decay rate and improved overall

  2. Effects of fatty acid activation on photosynthetic production of fatty acid-based biofuels in Synechocystis sp. PCC6803

    Directory of Open Access Journals (Sweden)

    Gao Qianqian

    2012-03-01

    Full Text Available Abstract Background Direct conversion of solar energy and carbon dioxide to drop in fuel molecules in a single biological system can be achieved from fatty acid-based biofuels such as fatty alcohols and alkanes. These molecules have similar properties to fossil fuels but can be produced by photosynthetic cyanobacteria. Results Synechocystis sp. PCC6803 mutant strains containing either overexpression or deletion of the slr1609 gene, which encodes an acyl-ACP synthetase (AAS, have been constructed. The complete segregation and deletion in all mutant strains was confirmed by PCR analysis. Blocking fatty acid activation by deleting slr1609 gene in wild-type Synechocystis sp. PCC6803 led to a doubling of the amount of free fatty acids and a decrease of alkane production by up to 90 percent. Overexpression of slr1609 gene in the wild-type Synechocystis sp. PCC6803 had no effect on the production of either free fatty acids or alkanes. Overexpression or deletion of slr1609 gene in the Synechocystis sp. PCC6803 mutant strain with the capability of making fatty alcohols by genetically introducing fatty acyl-CoA reductase respectively enhanced or reduced fatty alcohol production by 60 percent. Conclusions Fatty acid activation functionalized by the slr1609 gene is metabolically crucial for biosynthesis of fatty acid derivatives in Synechocystis sp. PCC6803. It is necessary but not sufficient for efficient production of alkanes. Fatty alcohol production can be significantly improved by the overexpression of slr1609 gene.

  3. 1H, 13C and 15N resonance assignments of the arsenate reductase from Synechocystis sp. strain PCC 6803.

    Science.gov (United States)

    Yu, Caifang; Xia, Bin; Jin, Changwen

    2011-04-01

    Arsenate reductases (ArsC) are a group of enzymes that play essential roles in biological arsenic detoxification pathways by catalyzing the intracellular reduction of arsenate to arsenite, which is subsequently extruded from the cells by specific transport systems. The ArsC protein from cyanobacterium Synechocystis sp. strain PCC 6803 (SynArsC) is related to the thioredoxin-dependent ArsC family, but uses the glutathione/glutaredoxin system for arsenate reduction. Therefore, it is classified to a novel thioredoxin/glutaredoxin hybrid arsenate reductase family. Herein we report the chemical shift assignments of (1)H, (13)C and (15)N atoms for the reduced form of SynArsC, which provides a starting point for further structural analysis and elucidation of its enzymatic mechanism.

  4. Comparative genome analysis of the closely related Synechocystis strains PCC 6714 and PCC 6803.

    Science.gov (United States)

    Kopf, Matthias; Klähn, Stephan; Pade, Nadin; Weingärtner, Christian; Hagemann, Martin; Voß, Björn; Hess, Wolfgang R

    2014-06-01

    Synechocystis sp. PCC 6803 is the most popular cyanobacterial model for prokaryotic photosynthesis and for metabolic engineering to produce biofuels. Genomic and transcriptomic comparisons between closely related bacteria are powerful approaches to infer insights into their metabolic potentials and regulatory networks. To enable a comparative approach, we generated the draft genome sequence of Synechocystis sp. PCC 6714, a closely related strain of 6803 (16S rDNA identity 99.4%) that also is amenable to genetic manipulation. Both strains share 2838 protein-coding genes, leaving 845 unique genes in Synechocystis sp. PCC 6803 and 895 genes in Synechocystis sp. PCC 6714. The genetic differences include a prophage in the genome of strain 6714, a different composition of the pool of transposable elements, and a ∼ 40 kb genomic island encoding several glycosyltransferases and transport proteins. We verified several physiological differences that were predicted on the basis of the respective genome sequence. Strain 6714 exhibited a lower tolerance to Zn(2+) ions, associated with the lack of a corresponding export system and a lowered potential of salt acclimation due to the absence of a transport system for the re-uptake of the compatible solute glucosylglycerol. These new data will support the detailed comparative analyses of this important cyanobacterial group than has been possible thus far. Genome information for Synechocystis sp. PCC 6714 has been deposited in Genbank (accession no AMZV01000000). © The Author 2014. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

  5. Analysis of proteins involved in the production of MAA׳s in two Cyanobacteria Synechocystis PCC 6803 and Anabaena cylindrica.

    Science.gov (United States)

    Rahman, Md Akhlaqur; Sinha, Sukrat; Sachan, Shephali; Kumar, Gaurav; Singh, Shailendra Kumar; Sundaram, Shanthy

    2014-01-01

    Mycosporine- like amino acids (MAAs) are small (MAAs is presumed to occur via the first part of shikimate pathway. In the present work two cyanobacteria Synechocystis PCC 6803 and Anabaena cylindrica were tested for their ability to synthesize MAAs and protein involved in the production of MAAs. It was found that protein sequence 3-phosphoshikimate 1-carboxyvinyltransferase is involved in producing mycosporine glycine in Synechocystis PCC 6803 and 3-dehydroquinate synthase is involved for producing shinorine in Anabaena cylindrica. Phylogenetic and bioinformatic analysis of Mycosporine like amino acid producing protein sequence of both cyanobacterial species Synechocystis PCC 6803 and Anabaena cylindrica provide a useful framework to understand the relationship of the different forms and how they have evolved from a common ancestor. These products seem to be conserved but the residues are prone to variation which might be due the fact that different cyanobacteria show different physiological process in response of Ultraviolet stress.

  6. Quantitative proteomics reveals dynamic responses of Synechocystis sp. PCC 6803 to next-generation biofuel butanol.

    Science.gov (United States)

    Tian, Xiaoxu; Chen, Lei; Wang, Jiangxin; Qiao, Jianjun; Zhang, Weiwen

    2013-01-14

    Butanol is a promising biofuel, and recent metabolic engineering efforts have demonstrated the use of photosynthetic cyanobacterial hosts for its production. However, cyanobacteria have very low tolerance to butanol, limiting the economic viability of butanol production from these renewable producing systems. The existing knowledge of molecular mechanism involved in butanol tolerance in cyanobacteria is very limited. To build a foundation necessary to engineer robust butanol-producing cyanobacterial hosts, in this study, the responses of Synechocystis PCC 6803 to butanol were investigated using a quantitative proteomics approach with iTRAQ - LC-MS/MS technologies. The resulting high-quality dataset consisted of 25,347 peptides corresponding to 1452 unique proteins, a coverage of approximately 40% of the predicted proteins in Synechocystis. Comparative quantification of protein abundances led to the identification of 303 differentially regulated proteins by butanol. Annotation and GO term enrichment analysis showed that multiple biological processes were regulated, suggesting that Synechocystis probably employed multiple and synergistic resistance mechanisms in dealing with butanol stress. Notably, the analysis revealed the induction of heat-shock protein and transporters, along with modification of cell membrane and envelope were the major protection mechanisms against butanol. A conceptual cellular model of Synechocystis PCC 6803 responses to butanol stress was constructed to illustrate the putative molecular mechanisms employed to defend against butanol stress. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Increasing the Photoautotrophic Growth Rate of Synechocystis sp. PCC 6803 by Identifying the Limitations of Its Cultivation.

    Science.gov (United States)

    van Alphen, Pascal; Abedini Najafabadi, Hamed; Branco Dos Santos, Filipe; Hellingwerf, Klaas J

    2018-03-25

    Many conditions have to be optimized in order to be able to grow the cyanobacterium Synechocystis sp. PCC 6803 (Synechocystis) for an extended period of time under physiologically well-defined and constant conditions. It is still poorly understood what limits growth of this organism in batch and continuous cultures in BG-11, the standard medium used to grow Synechocystis. Through a series of batch experiments in flasks and continuous mode experiments in advanced photobioreactors, it is shown that the limiting nutrient during batch cultivation is sulfate, the depletion of which leads to ROS formation and rapid bleaching of pigments after entry into stationary phase. In continuous mode, however, the limiting nutrient is iron. Optimizing these growth conditions resulted in a so far highest growth rate of 0.16 h -1 (4.3 h doubling time), which is significantly higher than the textbook value of 0.09 h -1 (8 h doubling time). An improved medium, BG-11 for prolonged cultivation (BG-11-PC) is introduced, that allows for controlled, extended cultivation of Synechocystis, under well-defined physiological conditions. The data present here have implications for mass-culturing of cyanobacteria. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Computational protein structure modeling and analysis of UV-B stress protein in Synechocystis PCC 6803.

    Science.gov (United States)

    Rahman, Md Akhlaqur; Chaturvedi, Navaneet; Sinha, Sukrat; Pandey, Paras Nath; Gupta, Dwijendra Kumar; Sundaram, Shanthy; Tripathi, Ashutosh

    2013-01-01

    This study focuses on Ultra Violet stress (UVS) gene product which is a UV stress induced protein from cyanobacteria, Synechocystis PCC 6803. Three dimensional structural modeling of target UVS protein was carried out by homology modeling method. 3F2I pdb from Nostoc sp. PCC 7120 was selected as a suitable template protein structure. Ultimately, the detection of active binding regions was carried out for characterization of functional sites in modeled UV-B stress protein. The top five probable ligand binding sites were predicted and the common binding residues between target and template protein was analyzed. It has been validated for the first time that modeled UVS protein structure from Synechocystis PCC 6803 was structurally and functionally similar to well characterized UVS protein of another cyanobacterial species, Nostoc sp PCC 7120 because of having same structural motif and fold with similar protein topology and function. Investigations revealed that UVS protein from Synechocystis sp. might play significant role during ultraviolet resistance. Thus, it could be a potential biological source for remediation for UV induced stress.

  9. Coping with iron limitation: a metabolomic study of Synechocystis sp PCC 6803

    Czech Academy of Sciences Publication Activity Database

    Rivas-Ubach, A.; Poret-Peterson, A. T.; Penuelas, J.; Sardans, J.; Pérez-Trujillo, M.; Legido-Quigley, C.; Oravec, Michal; Urban, Otmar; Elser, J. J.

    2018-01-01

    Roč. 40, č. 2 (2018), č. článku 28. ISSN 0137-5881 R&D Projects: GA MŠk(CZ) LO1415; GA MŠk(CZ) LM2015061 Institutional support: RVO:86652079 Keywords : sp strain pcc-6803 * ocean acidification * unicellular cyanobacterium * marine-phytoplankton * foliar metabolomes * nitrogen-fixation * metal homeostasis * oxidative stress * pacific-ocean * responses * Metabolomics * Metallomics * Iron limitation * Cyanobacteria * Ecological stoichiometry Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 1.364, year: 2016

  10. Involvement of sulfoquinovosyl diacylglycerol in DNA synthesis in Synechocystis sp. PCC 6803

    Directory of Open Access Journals (Sweden)

    Aoki Motohide

    2012-02-01

    Full Text Available Abstract Background Sulfoquinovosyl diacylglycerol (SQDG is present in the membranes of cyanobacteria and their postulated progeny, plastids, in plants. A cyanobacterium, Synechocystis sp. PCC 6803, requires SQDG for growth: its mutant (SD1 with the sqdB gene for SQDG synthesis disrupted can grow with external supplementation of SQDG. However, upon removal of SQDG from the medium, its growth is retarded, with a decrease in the cellular content of SQDG throughout cell division, and finally ceases. Concomitantly with the decrease in SQDG, the maximal activity of photosynthesis at high-light intensity is repressed by 40%. Findings We investigated effects of SQDG-defect on physiological aspects in Synechocystis with the use of SD1. SD1 cells defective in SQDG exhibited normal photosynthesis at low-light intensity as on culturing. Meanwhile, SD1 cells defective in SQDG were impaired in light-activated heterotrophic growth as well as in photoautotrophic growth. Flow cytometric analysis of the photoautotrophically growing cells gave similar cell size histograms for the wild type and SD1 supplemented with SQDG. However, the profile of SD1 defective in SQDG changed such that large part of the cell population was increased in size. Of particular interest was the microscopic observation that the mitotic index, i.e., population of dumbbell-like cells with a septum, increased from 14 to 29% in the SD1 culture without SQDG. Flow cytometric analysis also showed that the enlarged cells of SD1 defective in SQDG contained high levels of Chl, however, the DNA content was low. Conclusions Our experiments strongly support the idea that photosynthesis is not the limiting factor for the growth of SD1 defective in SQDG, and that SQDG is responsible for some physiologically fundamental process common to both photoautotrophic and light-activated heterotrophic growth. Our findings suggest that the SQDG-defect allows construction of the photosynthetic machinery at an

  11. Identification of Substrain-Specific Mutations by Massively Parallel Whole-Genome Resequencing of Synechocystis sp. PCC 6803

    Science.gov (United States)

    Kanesaki, Yu; Shiwa, Yuh; Tajima, Naoyuki; Suzuki, Marie; Watanabe, Satoru; Sato, Naoki; Ikeuchi, Masahiko; Yoshikawa, Hirofumi

    2012-01-01

    The cyanobacterium, Synechocystis sp. PCC 6803, was the first photosynthetic organism whose genome sequence was determined in 1996 (Kazusa strain). It thus plays an important role in basic research on the mechanism, evolution, and molecular genetics of the photosynthetic machinery. There are many substrains or laboratory strains derived from the original Berkeley strain including glucose-tolerant (GT) strains. To establish reliable genomic sequence data of this cyanobacterium, we performed resequencing of the genomes of three substrains (GT-I, PCC-P, and PCC-N) and compared the data obtained with those of the original Kazusa strain stored in the public database. We found that each substrain has sequence differences some of which are likely to reflect specific mutations that may contribute to its altered phenotype. Our resequence data of the PCC substrains along with the proposed corrections/refinements of the sequence data for the Kazusa strain and its derivatives are expected to contribute to investigations of the evolutionary events in the photosynthetic and related systems that have occurred in Synechocystis as well as in other cyanobacteria. PMID:22193367

  12. Glycogen synthase isoforms in Synechocystis sp. PCC6803: identification of different roles to produce glycogen by targeted mutagenesis.

    Directory of Open Access Journals (Sweden)

    Sang-Ho Yoo

    Full Text Available Synechocystis sp. PCC6803 belongs to cyanobacteria which carry out photosynthesis and has recently become of interest due to the evolutionary link between bacteria and plant species. Similar to other bacteria, the primary carbohydrate storage source of Synechocystis sp. PCC6803 is glycogen. While most bacteria are not known to have any isoforms of glycogen synthase, analysis of the genomic DNA sequence of Synechocystis sp. PCC6803 predicts that this strain encodes two isoforms of glycogen synthase (GS for synthesizing glycogen structure. To examine the functions of the putative GS genes, each gene (sll1393 or sll0945 was disrupted by double cross-over homologous recombination. Zymogram analysis of the two GS disruption mutants allowed the identification of a protein band corresponding to each GS isoform. Results showed that two GS isoforms (GSI and GSII are present in Synechocystis sp. PCC6803, and both are involved in glycogen biosynthesis with different elongation properties: GSI is processive and GSII is distributive. Total GS activities in the mutant strains were not affected and were compensated by the remaining isoform. Analysis of the branch-structure of glycogen revealed that the sll1393- mutant (GSI- produced glycogen containing more intermediate-length chains (DP 8-18 at the expense of shorter and longer chains compared with the wild-type strain. The sll0945- mutant (GSII- produced glycogen similar to the wild-type, with only a slightly higher proportion of short chains (DP 4-11. The current study suggests that GS isoforms in Synechocystis sp. PCC6803 have different elongation specificities in the biosynthesis of glycogen, combined with ADP-glucose pyrophosphorylase and glycogen branching enzyme.

  13. Isolation and Structural Characterization of Monomeric and Trimeric Photosystem I Complexes (P700·FA/FB and P700·Fx) from the Cyanobacterium Synechocystis PCC 6803

    NARCIS (Netherlands)

    Kruip, Jochen; Boekema, Egbert J.; Bald, Dirk; Boonstra, Arjen F.; Rögner, Matthias

    1993-01-01

    An isolation procedure was developed for the cyanobacterium Synechocystis 6803 (and 6714) which yields both monomeric and trimeric photosystem I complexes (P700·FA/FB complexes) depleted of the stroma-exposed subunits PsaC, -D, and -E (P700·FX complexes). Analysis by high resolution gel

  14. ISOLATION AND STRUCTURAL CHARACTERIZATION OF MONOMERIC AND TRIMERIC PHOTOSYSTEM-I COMPLEXES (P700-CENTER-DOT-FA/FB AND P700-CENTER-DOT-FX) FROM THE CYANOBACTERIUM SYNECHOCYSTIS PCC-6803

    NARCIS (Netherlands)

    KRUIP, J; BOEKEMA, EJ; BALD, D; BOONSTRA, AF; ROGNER, M

    1993-01-01

    An isolation procedure was developed for the cyanobacterium Synechocystis 6803 (and 6714) which yields both monomeric and trimeric photosystem I complexes (P700.F(A)/F(B) complexes) depleted of the stroma-exposed subunits PsaC, -D, and -E (P700-F(x) complexes). Analysis by high resolution gel

  15. Deletion of the Synechocystis sp. PCC 6803 kaiAB1C1 gene cluster causes impaired cell growth under light-dark conditions.

    Science.gov (United States)

    Dörrich, Anja K; Mitschke, Jan; Siadat, Olga; Wilde, Annegret

    2014-11-01

    In contrast to Synechococcus elongatus PCC 7942, few data exist on the timing mechanism of the widely used cyanobacterium Synechocystis sp. PCC 6803. The standard kaiAB1C1 operon present in this organism was shown to encode a functional KaiC protein that interacted with KaiA, similar to the S. elongatus PCC 7942 clock. Inactivation of this operon in Synechocystis sp. PCC 6803 resulted in a mutant with a strong growth defect when grown under light-dark cycles, which was even more pronounced when glucose was added to the growth medium. In addition, mutants showed a bleaching phenotype. No effects were detected in mutant cells grown under constant light. Microarray experiments performed with cells grown for 1 day under a light-dark cycle revealed many differentially regulated genes with known functions in the ΔkaiABC mutant in comparison with the WT. We identified the genes encoding the cyanobacterial phytochrome Cph1 and the light-repressed protein LrtA as well as several hypothetical ORFs with a complete inverse behaviour in the light cycle. These transcripts showed a stronger accumulation in the light but a weaker accumulation in the dark in ΔkaiABC cells in comparison with the WT. In general, we found a considerable overlap with microarray data obtained for hik31 and sigE mutants. These genes are known to be important regulators of cell metabolism in the dark. Strikingly, deletion of the ΔkaiABC operon led to a much stronger phenotype under light-dark cycles in Synechocystis sp. PCC 6803 than in Synechococcus sp. PCC 7942. © 2014 The Authors.

  16. Respiratory terminal oxidases alleviate photo-oxidative damage in photosystem I during repetitive short-pulse illumination in Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Shimakawa, Ginga; Miyake, Chikahiro

    2018-03-08

    Oxygenic phototrophs are vulnerable to damage by reactive oxygen species (ROS) that are produced in photosystem I (PSI) by excess photon energy over the demand of photosynthetic CO 2 assimilation. In plant leaves, repetitive short-pulse (rSP) illumination produces ROS to inactivate PSI. The production of ROS is alleviated by oxidation of the reaction center chlorophyll in PSI, P700, during the illumination with the short-pulse light, which is supported by flavodiiron protein (FLV). In this study, we found that in the cyanobacterium Synechocystis sp. PCC 6803 P700 was oxidized and PSI was not inactivated during rSP illumination even in the absence of FLV. Conversely, the mutant deficient in respiratory terminal oxidases was impaired in P700 oxidation during the illumination with the short-pulse light to suffer from photo-oxidative damage in PSI. Interestingly, the other cyanobacterium Synechococcus sp. PCC 7002 could not oxidize P700 without FLV during rSP illumination. These data indicate that respiratory terminal oxidases are critical to protect PSI from ROS damage during rSP illumination in Synechocystis sp. PCC 6803 but not Synechococcus sp. PCC 7002.

  17. Proteomic analysis reveals resistance mechanism against biofuel hexane in Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Liu, Jie; Chen, Lei; Wang, Jiangxin; Qiao, Jianjun; Zhang, Weiwen

    2012-09-07

    Recent studies have demonstrated that photosynthetic cyanobacteria could be an excellent cell factory to produce renewable biofuels and chemicals due to their capability to utilize solar energy and CO2 as the sole energy and carbon sources. Biosynthesis of carbon-neutral biofuel alkanes with good chemical and physical properties has been proposed. However, to make the process economically feasible, one major hurdle to improve the low cell tolerance to alkanes needed to be overcome. Towards the goal to develop robust and high-alkane-tolerant hosts, in this study, the responses of model cyanobacterial Synechocystis PCC 6803 to hexane, a representative of alkane, were investigated using a quantitative proteomics approach with iTRAQ - LC-MS/MS technologies. In total, 1,492 unique proteins were identified, representing about 42% of all predicted protein in the Synechocystis genome. Among all proteins identified, a total of 164 and 77 proteins were found up- and down-regulated, respectively. Functional annotation and KEGG pathway enrichment analyses showed that common stress responses were induced by hexane in Synechocystis. Notably, a large number of transporters and membrane-bound proteins, proteins against oxidative stress and proteins related to sulfur relay system and photosynthesis were induced, suggesting that they are possibly the major protection mechanisms against hexane toxicity. The study provided the first comprehensive view of the complicated molecular mechanism employed by cyanobacterial model species, Synechocystis to defend against hexane stress. The study also provided a list of potential targets to engineer Synechocystis against hexane stress.

  18. Engineering Synechocystis PCC6803 for hydrogen production: influence on the tolerance to oxidative and sugar stresses.

    Directory of Open Access Journals (Sweden)

    Marcia Ortega-Ramos

    Full Text Available In the prospect of engineering cyanobacteria for the biological photoproduction of hydrogen, we have studied the hydrogen production machine in the model unicellular strain Synechocystis PCC6803 through gene deletion, and overexpression (constitutive or controlled by the growth temperature. We demonstrate that the hydrogenase-encoding hoxEFUYH operon is dispensable to standard photoautotrophic growth in absence of stress, and it operates in cell defense against oxidative (H₂O₂ and sugar (glucose and glycerol stresses. Furthermore, we showed that the simultaneous over-production of the proteins HoxEFUYH and HypABCDE (assembly of hydrogenase, combined to an increase in nickel availability, led to an approximately 20-fold increase in the level of active hydrogenase. These novel results and mutants have major implications for those interested in hydrogenase, hydrogen production and redox metabolism, and their connections with environmental conditions.

  19. The rnb gene of Synechocystis PCC6803 encodes a RNA hydrolase displaying RNase II and not RNase R enzymatic properties.

    Directory of Open Access Journals (Sweden)

    Rute G Matos

    Full Text Available Cyanobacteria are photosynthetic prokaryotic organisms that share characteristics with bacteria and chloroplasts regarding mRNA degradation. Synechocystis sp. PCC6803 is a model organism for cyanobacteria, but not much is known about the mechanism of RNA degradation. Only one member of the RNase II-family is present in the genome of Synechocystis sp PCC6803. This protein was shown to be essential for its viability, which indicates that it may have a crucial role in the metabolism of Synechocystis RNA. The aim of this work was to characterize the activity of the RNase II/R homologue present in Synechocystis sp. PCC6803. The results showed that as expected, it displayed hydrolytic activity and released nucleoside monophosphates. When compared to two E. coli counterparts, the activity assays showed that the Synechocystis protein displays RNase II, and not RNase R characteristics. This is the first reported case where when only one member of the RNase II/R family exists it displays RNase II and not RNase R characteristics.

  20. Identification of gene disruptions for increased poly-3-hydroxybutyrate accumulation in Synechocystis PCC 6803.

    Science.gov (United States)

    Tyo, Keith E J; Jin, Yong-Su; Espinoza, Freddy A; Stephanopoulos, Gregory

    2009-01-01

    Inverse metabolic engineering (IME) is a combinatorial approach for identifying genotypes associated with a particular phenotype of interest. In this study, gene disruptions that increase the biosynthesis of poly-3-hydroxybutyrate (PHB) in the photosynthetic bacterium Synechocystis PCC6803 were identified. A Synechocystis mutant library was constructed by homologous recombination between the Synechocystis genome and a mutagenized genomic plasmid library generated through transposon insertion. Using a fluorescence-activated cell sorting-based high throughput screen, high PHB accumulating mutants from the library grown in different nutrient conditions were isolated and characterized. While several mutants isolated from the screen had increased PHB accumulation, transposon insertions in only two ORFs could be linked to increased PHB production. Disruptions of sll0461, coding for gamma-glutamyl phosphate reductase (proA), and sll0565, a hypothetical protein, resulted in increased accumulation in standard growth media and acetate supplemented media. These genetic perturbations have increased PHB accumulation in Synechocystis and serve as markers for engineering increased polymer production in higher photosynthetic organisms. 2009 American Institute of Chemical Engineers Biotechnol.

  1. Isobutanol production in Synechocystis PCC 6803 using heterologous and endogenous alcohol dehydrogenases

    Directory of Open Access Journals (Sweden)

    Rui Miao

    2017-12-01

    Full Text Available Isobutanol is a flammable compound that can be used as a biofuel due to its high energy density and suitable physical and chemical properties. In this study, we examined the capacity of engineered strains of Synechocystis PCC 6803 containing the α-ketoisovalerate decarboxylase from Lactococcus lactis and different heterologous and endogenous alcohol dehydrogenases (ADH for isobutanol production. A strain expressing an introduced kivd without any additional copy of ADH produced 3 mg L−1 OD750−1 isobutanol in 6 days. After the cultures were supplemented with external addition of isobutyraldehyde, the substrate for ADH, 60.8 mg L−1 isobutanol was produced after 24 h when OD750 was 0.8. The in vivo activities of four different ADHs, two heterologous and two putative endogenous in Synechocystis, were examined and the Synechocystis endogenous ADH encoded by slr1192 showed the highest efficiency for isobutanol production. Furthermore, the strain overexpressing the isobutanol pathway on a self-replicating vector with the strong Ptrc promoter showed significantly higher gene expression and isobutanol production compared to the corresponding strains expressing the same operon introduced on the genome. Hence, this study demonstrates that Synechocystis endogenous AHDs have a high capacity for isobutanol production, and identifies kivd encoded α-ketoisovalerate decarboxylase as one of the likely bottlenecks for further isobutanol production.

  2. Long-Term Acclimation of the Cyanobacterium Synechocystis sp PCC 6803 to High Light Is Accompanied by an Enhanced Production of Chlorophyll That Is Preferentially Channeled to Trimeric Photosystem I

    Czech Academy of Sciences Publication Activity Database

    Kopečná, Jana; Komenda, Josef; Bučinská, Lenka; Sobotka, Roman

    2012-01-01

    Roč. 160, č. 4 (2012), s. 2239-2250 ISSN 0032-0889 R&D Projects: GA MŠk(CZ) ED2.1.00/03.0110; GA ČR GAP501/10/1000; GA ČR GBP501/12/G055 Institutional support: RVO:61388971 Keywords : CAB-LIKE-PROTEINS * SP PCC-6803 * PHOTOSYNTHETIC APPARATUS Subject RIV: EE - Microbiology, Virology Impact factor: 6.555, year: 2012

  3. A systems biology approach to reconcile metabolic network models with application to Synechocystis sp. PCC 6803 for biofuel production.

    Science.gov (United States)

    Mohammadi, Reza; Fallah-Mehrabadi, Jalil; Bidkhori, Gholamreza; Zahiri, Javad; Javad Niroomand, Mohammad; Masoudi-Nejad, Ali

    2016-07-19

    Production of biofuels has been one of the promising efforts in biotechnology in the past few decades. The perspective of these efforts can be reduction of increasing demands for fossil fuels and consequently reducing environmental pollution. Nonetheless, most previous approaches did not succeed in obviating many big challenges in this way. In recent years systems biology with the help of microorganisms has been trying to overcome these challenges. Unicellular cyanobacteria are widespread phototrophic microorganisms that have capabilities such as consuming solar energy and atmospheric carbon dioxide for growth and thus can be a suitable chassis for the production of valuable organic materials such as biofuels. For the ultimate use of metabolic potential of cyanobacteria, it is necessary to understand the reactions that are taking place inside the metabolic network of these microorganisms. In this study, we developed a Java tool to reconstruct an integrated metabolic network of a cyanobacterium (Synechocystis sp. PCC 6803). We merged three existing reconstructed metabolic networks of this microorganism. Then, after modeling for biofuel production, the results from flux balance analysis (FBA) disclosed an increased yield in biofuel production for ethanol, isobutanol, 3-methyl-1-butanol, 2-methyl-1-butanol, and propanol. The numbers of blocked reactions were also decreased for 2-methyl-1-butanol production. In addition, coverage of the metabolic network in terms of the number of metabolites and reactions was increased in the new obtained model.

  4. NblA1/A2-Dependent Homeostasis of Amino Acid Pools during Nitrogen Starvation in Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Kiyota, Hiroshi; Hirai, Masami Yokota; Ikeuchi, Masahiko

    2014-06-30

    Nutrient balance is important for photosynthetic growth and biomass production in microalgae. Here, we investigated and compared metabolic responses of amino acid pools to nitrogen and sulfur starvation in a unicellular model cyanobacterium, Synechocystis sp. PCC 6803, and its mutant nblA1/A2. It is known that NblA1/A2-dependent and -independent breakdown of abundant photosynthetic phycobiliproteins and other cellular proteins supply nutrients to the organism. However, the contribution of the NblA1/A2-dependent nutrient supply to amino acid pool homeostasis has not been studied. Our study demonstrates that changes in the pool size of many amino acids during nitrogen starvation can be categorized as NblA1/A2-dependent (Gln, Glu, glutathione, Gly, Ile, Leu, Met, Phe, Pro, Ser, Thr, Tyr and Val) and NblA1/A2-independent (Ala, Asn, Lys, and Trp). We also report unique changes in amino acid pool sizes during sulfur starvation in wild type and the mutant and found a generally marked increase in the Lys pool in cyanobacteria during nutrient starvation. In conclusion, the NblA1/A2-dependent protein turnover contributes to the maintenance of many amino acid pools during nitrogen starvation.

  5. NblA1/A2-Dependent Homeostasis of Amino Acid Pools during Nitrogen Starvation in Synechocystis sp. PCC 6803

    Directory of Open Access Journals (Sweden)

    Hiroshi Kiyota

    2014-06-01

    Full Text Available Nutrient balance is important for photosynthetic growth and biomass production in microalgae. Here, we investigated and compared metabolic responses of amino acid pools to nitrogen and sulfur starvation in a unicellular model cyanobacterium, Synechocystis sp. PCC 6803, and its mutant nblA1/A2. It is known that NblA1/A2-dependent and -independent breakdown of abundant photosynthetic phycobiliproteins and other cellular proteins supply nutrients to the organism. However, the contribution of the NblA1/A2-dependent nutrient supply to amino acid pool homeostasis has not been studied. Our study demonstrates that changes in the pool size of many amino acids during nitrogen starvation can be categorized as NblA1/A2-dependent (Gln, Glu, glutathione, Gly, Ile, Leu, Met, Phe, Pro, Ser, Thr, Tyr and Val and NblA1/A2-independent (Ala, Asn, Lys, and Trp. We also report unique changes in amino acid pool sizes during sulfur starvation in wild type and the mutant and found a generally marked increase in the Lys pool in cyanobacteria during nutrient starvation. In conclusion, the NblA1/A2-dependent protein turnover contributes to the maintenance of many amino acid pools during nitrogen starvation.

  6. Proteomic analysis reveals resistance mechanism against biofuel hexane in Synechocystis sp. PCC 6803

    Directory of Open Access Journals (Sweden)

    Liu Jie

    2012-09-01

    Full Text Available Abstract Background Recent studies have demonstrated that photosynthetic cyanobacteria could be an excellent cell factory to produce renewable biofuels and chemicals due to their capability to utilize solar energy and CO2 as the sole energy and carbon sources. Biosynthesis of carbon-neutral biofuel alkanes with good chemical and physical properties has been proposed. However, to make the process economically feasible, one major hurdle to improve the low cell tolerance to alkanes needed to be overcome. Results Towards the goal to develop robust and high-alkane-tolerant hosts, in this study, the responses of model cyanobacterial Synechocystis PCC 6803 to hexane, a representative of alkane, were investigated using a quantitative proteomics approach with iTRAQ - LC-MS/MS technologies. In total, 1,492 unique proteins were identified, representing about 42% of all predicted protein in the Synechocystis genome. Among all proteins identified, a total of 164 and 77 proteins were found up- and down-regulated, respectively. Functional annotation and KEGG pathway enrichment analyses showed that common stress responses were induced by hexane in Synechocystis. Notably, a large number of transporters and membrane-bound proteins, proteins against oxidative stress and proteins related to sulfur relay system and photosynthesis were induced, suggesting that they are possibly the major protection mechanisms against hexane toxicity. Conclusion The study provided the first comprehensive view of the complicated molecular mechanism employed by cyanobacterial model species, Synechocystis to defend against hexane stress. The study also provided a list of potential targets to engineer Synechocystis against hexane stress.

  7. The photosynthetic bacteria Rhodobacter capsulatus and Synechocystis sp. PCC 6803 as new hosts for cyclic plant triterpene biosynthesis.

    Directory of Open Access Journals (Sweden)

    Anita Loeschcke

    Full Text Available Cyclic triterpenes constitute one of the most diverse groups of plant natural products. Besides the intriguing biochemistry of their biosynthetic pathways, plant triterpenes exhibit versatile bioactivities, including antimicrobial effects against plant and human pathogens. While prokaryotes have been extensively used for the heterologous production of other classes of terpenes, the synthesis of cyclic triterpenes, which inherently includes the two-step catalytic formation of the universal linear precursor 2,3-oxidosqualene, is still a major challenge. We thus explored the suitability of the metabolically versatile photosynthetic α-proteobacterium Rhodobacter capsulatus SB1003 and cyanobacterium Synechocystis sp. PCC 6803 as alternative hosts for biosynthesis of cyclic plant triterpenes. Therefore, 2,3-oxidosqualene production was implemented and subsequently combined with different cyclization reactions catalyzed by the representative oxidosqualene cyclases CAS1 (cycloartenol synthase, LUP1 (lupeol synthase, THAS1 (thalianol synthase and MRN1 (marneral synthase derived from model plant Arabidopsis thaliana. While successful accumulation of 2,3-oxidosqualene could be detected by LC-MS analysis in both hosts, cyclase expression resulted in differential production profiles. CAS1 catalyzed conversion to only cycloartenol, but expression of LUP1 yielded lupeol and a triterpenoid matching an oxidation product of lupeol, in both hosts. In contrast, THAS1 expression did not lead to cyclic product formation in either host, whereas MRN1-dependent production of marnerol and hydroxymarnerol was observed in Synechocystis but not in R. capsulatus. Our findings thus indicate that 2,3-oxidosqualene cyclization in heterologous phototrophic bacteria is basically feasible but efficient conversion depends on both the respective cyclase enzyme and individual host properties. Therefore, photosynthetic α-proteo- and cyanobacteria are promising alternative candidates

  8. Structural integrity of Synechocystis sp. PCC 6803 phycobilisomes evaluated by means of differential scanning calorimetry.

    Science.gov (United States)

    Petrova, Nia; Todinova, Svetla; Laczko-Dobos, Hajnalka; Zakar, Tomas; Vajravel, Sindhujaa; Taneva, Stefka; Gombos, Zoltan; Krumova, Sashka

    2018-01-10

    Phycobilisomes (PBSs) are supramolecular pigment-protein complexes that serve as light-harvesting antennae in cyanobacteria. They are built up by phycobiliproteins assembled into allophycocyanin core cylinders (ensuring the physical interaction with the photosystems) and phycocyanin rods (protruding from the cores and having light-harvesting function), the whole PBSs structure being maintained by linker proteins. PBSs play major role in light-harvesting optimization in cyanobacteria; therefore, the characterization of their structural integrity in intact cells is of great importance. The present study utilizes differential scanning calorimetry and spectroscopy techniques to explore for the first time, the thermodynamic stability of PBSs in intact Synechocystis sp. PCC 6803 cells and to probe its alteration as a result of mutations or under different growth conditions. As a first step, we characterize the thermodynamic behavior of intact and dismantled PBSs isolated from wild-type cells (having fully assembled PBSs) and from CK mutant cells (that lack phycocyanin rods and contain only allophycocyanin cores), and identified the thermal transitions of phycocyanin and allophycocyanin units in vitro. Next, we demonstrate that in intact cells PBSs exhibit sharp, high amplitude thermal transition at about 63 °C that strongly depends on the structural integrity of the PBSs supercomplex. Our findings implicate that calorimetry could offer a valuable approach for the assessment of the influence of variety of factors affecting the stability and structural organization of phycobilisomes in intact cyanobacterial cells.

  9. Metabolic flux analysis of the hydrogen production potential in Synechocystis sp. PCC6803

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, E. [Departamento de Lenguajes y Ciencias de la Computacion, Campus de Teatrinos, Universidad de Malaga, 29071 Malaga (Spain); Montagud, A.; Fernandez de Cordoba, P.; Urchueguia, J.F. [Instituto Universitario de Matematica Pura y Aplicada, Universidad Politecnica de Valencia, Camino de Vera 14, 46022 Valencia (Spain)

    2009-11-15

    Hydrogen is a promising energy vector; however, finding methods to produce it from renewable sources is essential to allow its wide-scale use. In that line, biological hydrogen production, although it is considered as a possible alternative, requires substantial improvements to overcome its present low yields. In that direction, genetic manipulation probably will play a central role and from that point of view metabolic flux analysis (MFA) constitutes an important tool to guide a priori most suitable genetic modifications oriented to a hydrogen yield increase. In this work MFA has been applied to analyze hydrogen photoproduction of Synechocystis sp. PCC6803. Flux analysis was carried out based on literature data and several basic fluxes were estimated in different growing conditions of the system. From this analysis, an upper limit for hydrogen photoproduction has been determined indicating a wide margin for improvement. MFA was also used to find a feasible operating space for hydrogen production, which avoids oxygen inhibition, one of the most important limitations to make hydrogen production cost effective. In addition, a set of biotechnological strategies are proposed that would be consistent with the performed mathematical analysis. (author)

  10. Strain of Synechocystis PCC 6803 with Aberrant Assembly of Photosystem II Contains Tandem Duplication of a Large Chromosomal Region.

    Science.gov (United States)

    Tichý, Martin; Bečková, Martina; Kopečná, Jana; Noda, Judith; Sobotka, Roman; Komenda, Josef

    2016-01-01

    Cyanobacterium Synechocystis PCC 6803 represents a favored model organism for photosynthetic studies. Its easy transformability allowed construction of a vast number of Synechocystis mutants including many photosynthetically incompetent ones. However, it became clear that there is already a spectrum of Synechocystis "wild-type" substrains with apparently different phenotypes. Here, we analyzed organization of photosynthetic membrane complexes in a standard motile Pasteur collection strain termed PCC and two non-motile glucose-tolerant substrains (named here GT-P and GT-W) previously used as genetic backgrounds for construction of many photosynthetic site directed mutants. Although, both the GT-P and GT-W strains were derived from the same strain constructed and described by Williams in 1988, only GT-P was similar in pigmentation and in the compositions of Photosystem II (PSII) and Photosystem I (PSI) complexes to PCC. In contrast, GT-W contained much more carotenoids but significantly less chlorophyll (Chl), which was reflected by lower level of dimeric PSII and especially trimeric PSI. We found that GT-W was deficient in Chl biosynthesis and contained unusually high level of unassembled D1-D2 reaction center, CP47 and especially CP43. Another specific feature of GT-W was a several fold increase in the level of the Ycf39-Hlip complex previously postulated to participate in the recycling of Chl molecules. Genome re-sequencing revealed that the phenotype of GT-W is related to the tandem duplication of a large region of the chromosome that contains 100 genes including ones encoding D1, Psb28, and other PSII-related proteins as well as Mg-protoporphyrin methylester cyclase (Cycl). Interestingly, the duplication was completely eliminated after keeping GT-W cells on agar plates under photoautotrophic conditions for several months. The GT-W strain without a duplication showed no obvious defects in PSII assembly and resembled the GT-P substrain. Although, we do not exactly

  11. Isolation of cyanobacterial mutants exhibiting growth defects under microoxic conditions by transposon tagging mutagenesis of Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Terauchi, Kazuki; Sobue, Riho; Furutani, Yuho; Aoki, Rina; Fujita, Yuichi

    2017-05-12

    Cyanobacteria are photosynthetic prokaryotes that perform oxygenic photosynthesis by extracting electrons from water, with the generation of oxygen as a byproduct. Cyanobacteria use oxygen not only for respiration to produce energy in the dark but also for biosynthesis of various metabolites, such as heme and chlorophyll. Oxygen levels dynamically fluctuate in the field environments, from hyperoxic at daytime to almost anaerobic at night. Thus, adaptation to anaerobiosis should be important for cyanobacteria to survive in low-oxygen and anaerobic environments. However, little is known about the molecular mechanisms of cyanobacterial anaerobiosis because cyanobacteria have been regarded as aerobic organisms. As a first step to elucidate cyanobacterial adaptation mechanisms to low-oxygen environments, we isolated five mutants, T-1-T-5, exhibiting growth defects under microoxic conditions. The mutants were obtained from a transposon-tagged mutant library of the cyanobacterium Synechocystis sp. PCC 6803, which was produced by in vitro transposon tagging of cyanobacterial genomic DNA. Southern blot analysis indicated that a kanamycin resistance gene was inserted in the genome as a single copy. We identified the chromosomal transposon-tagged locus in T-5. Two open reading frames (sll0577 and sll0578) were partially deleted by the insertion of the kanamycin resistance gene in T-5. A reverse transcription polymerase chain reaction suggested that these co-transcribed genes are constitutively expressed under both aerobic and microoxic conditions. Then, we isolated two mutants in which one of the two genes was individually disrupted. Only the mutants partially lacking an intact sll0578 gene showed growth defects under microoxic conditions, whereas it grew normally under aerobic conditions. sll0578 is annotated as purK encoding N 5 -carboxy-aminoimidazole ribonucleotide synthetase involved in purine metabolism. This result implies the unexpected physiological importance of Pur

  12. Synechocystis sp. PCC 6803 CruA (sll0147) encodes lycopene cyclase and requires bound chlorophyll a for activity.

    Science.gov (United States)

    Xiong, Wei; Shen, Gaozhong; Bryant, Donald A

    2017-03-01

    The genome of the model cyanobacterium, Synechococcus sp. PCC 7002, encodes two paralogs of CruA-type lycopene cyclases, SynPCC7002_A2153 and SynPCC7002_A0043, which are denoted cruA and cruP, respectively. Unlike the wild-type strain, a cruA deletion mutant is light-sensitive, grows slowly, and accumulates lycopene, γ-carotene, and 1-OH-lycopene; however, this strain still produces β-carotene and other carotenoids derived from it. Expression of cruA from Synechocystis sp. PCC 6803 (cruA 6803 ) in Escherichia coli strains that synthesize either lycopene or γ-carotene did not lead to the synthesis of either γ-carotene or β-carotene, respectively. However, expression of this orthologous cruA 6803 gene (sll0147) in the Synechococcus sp. PCC 7002 cruA deletion mutant produced strains with phenotypic properties identical to the wild type. CruA 6803 was purified from Synechococcus sp. PCC 7002 by affinity chromatography, and the purified protein was pale yellow-green due to the presence of bound chlorophyll (Chl) a and β-carotene. Native polyacrylamide gel electrophoresis of the partly purified protein in the presence of lithium dodecylsulfate at 4 °C confirmed that the protein was yellow-green in color. When purified CruA 6803 was assayed in vitro with either lycopene or γ-carotene as substrate, β-carotene was synthesized. These data establish that CruA 6803 is a lycopene cyclase and that it requires a bound Chl a molecule for activity. Possible binding sites for Chl a and the potential regulatory role of the Chl a in coordination of Chl and carotenoid biosynthesis are discussed.

  13. Physiological and molecular characterization of a Synechocystis sp. PCC 6803 mutant lacking histidine kinase Slr1759 and response regulator Slr1760.

    Science.gov (United States)

    Nodop, Anke; Suzuki, Iwane; Barsch, Aiko; Schröder, Ann-Kristin; Niehaus, Karsten; Staiger, Dorothee; Pistorius, Elfriede K; Michel, Klaus-Peter

    2006-01-01

    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 Hikl4 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.

  14. Photophysiological and photosynthetic complex changes during iron starvation in Synechocystis sp. PCC 6803 and Synechococcus elongatus PCC 7942.

    Science.gov (United States)

    Fraser, Jared M; Tulk, Sarah E; Jeans, Jennifer A; Campbell, Douglas A; Bibby, Thomas S; Cockshutt, Amanda M

    2013-01-01

    Iron is an essential component in many protein complexes involved in photosynthesis, but environmental iron availability is often low as oxidized forms of iron are insoluble in water. To adjust to low environmental iron levels, cyanobacteria undergo numerous changes to balance their iron budget and mitigate the physiological effects of iron depletion. We investigated changes in key protein abundances and photophysiological parameters in the model cyanobacteria Synechococcus PCC 7942 and Synechocystis PCC 6803 over a 120 hour time course of iron deprivation. The iron stress induced protein (IsiA) accumulated to high levels within 48 h of the onset of iron deprivation, reaching a molar ratio of ~42 IsiA : Photosystem I in Synechococcus PCC 7942 and ~12 IsiA : Photosystem I in Synechocystis PCC 6803. Concomitantly the iron-rich complexes Cytochrome b6f and Photosystem I declined in abundance, leading to a decrease in the Photosystem I : Photosystem II ratio. Chlorophyll fluorescence analyses showed a drop in electron transport per Photosystem II in Synechococcus, but not in Synechocystis after iron depletion. We found no evidence that the accumulated IsiA contributes to light capture by Photosystem II complexes.

  15. The role of Slr0151, a tetratricopeptide repeat protein from Synechocystis sp. PCC 6803, during Photosystem II assembly and repair

    Directory of Open Access Journals (Sweden)

    Anna eRast

    2016-05-01

    Full Text Available The assembly and repair of photosystem II (PSII is facilitated by a variety of assembly factors. Among those, the tetratricopeptide repeat (TPR protein Slr0151 from Synechocystis sp. PCC 6803 (hereafter Synechocystis has previously been assigned a repair function under high light conditions (Yang et al., 2014, J. Integr. Plant Biol. 56, 1136-50. Here, we show that inactivation of Slr0151 affects thylakoid membrane ultrastructure even under normal light conditions. Moreover, the level and localization of Slr0151 are affected in a variety of PSII-related mutants. In particular, the data suggest a close functional relationship between Slr0151 and Sll0933, which interacts with Ycf48 during PSII assembly and is homologous to PAM68 in Arabidopsis thaliana. Immunofluorescence analysis revealed a punctate distribution of Slr0151 within several different membrane types in Synechocystis cells.

  16. A synthetic DNA and fusion PCR approach to the ectopic expression of high levels of the D1 protein of photosystem II in Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Nagarajan, Aparna; Winter, Regan; Eaton-Rye, Julian; Burnap, Robert

    2011-01-01

    A hybrid approach involving synthetic DNA, fusion PCR, and ectopic expression has been used to genetically manipulate the expression of the D1 protein of photosystem II (PSII) in the model cyanobacterium Synechocystis sp. PCC6803. Due to the toxicity of the full-length psbA gene in E. coli, a chimeric psbA2 gene locus was commercially synthesised and cloned in two halves. High-fidelity fusion PCR utilizing sequence overlap between the two synthetic gene halves allowed the production of a DNA fragment that was able to recombine the full-length psbA2 gene into the Synechocystis chromosome at an ectopic (non-native) location. This was accomplished by designing the synthetic DNA/fusion PCR product to have the psbA2 gene, with control sequences, interposed between chimeric sequences corresponding to an ectopic target chromosomal location. Additionally, a recipient strain of Synechocystis lacking all three psbA genes was produced by a combination of traditional marker replacement and markerless replacement techniques. Transformation of this multiple deletion strain by the synthetic DNA/fusion PCR product faithfully restored D1 expression in terms of its expression and PSII repair capacity. The advantages and potential issues for using this approach to rapidly introduce chimeric sequence characteristics as a general tool to produce novel genetic constructs are discussed. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. NDH-1 Is Important for Photosystem I Function of Synechocystis sp. Strain PCC 6803 under Environmental Stress Conditions

    Directory of Open Access Journals (Sweden)

    Jiaohong Zhao

    2018-01-01

    Full Text Available Cyanobacterial NDH-1 interacts with photosystem I (PSI to form an NDH-1-PSI supercomplex. Here, we observed that absence of NDH-1 had little, if any, effect on the functional fractions of PSI under growth conditions, but significantly reduced the functional fractions of PSI when cells of Synechocystis sp. strain PCC 6803 were moved to conditions of multiple stresses. The significant reduction in NDH-1-dependent functional fraction of PSI was initiated after PSII activity was impaired. This finding is consistent with our observation that the functional fraction of PSI under growth conditions was rapidly and significantly decreased with increasing concentrations of DCMU, which rapidly and significantly suppressed PSII activity by blocking the transfer of electrons from QA to QB in the PSII reaction center. Furthermore, absence of NDH-1 resulted in the PSI limitation at the functionality of PSI itself but not its donor-side and acceptor-side under conditions of multiple stresses. This was supported by the result of a significant destabilization of the PSI complex in the absence of NDH-1 but the presence of multiple stresses. Based on the above results, we propose that NDH-1 is important for PSI function of Synechocystis sp. strain PCC 6803 mainly via maintaining stabilization of PSI under conditions of environmental stresses.

  18. A Toxin-Antitoxin System VapBC15 from Synechocystis sp. PCC 6803 Shows Distinct Regulatory Features

    Directory of Open Access Journals (Sweden)

    Qian Fei

    2018-03-01

    Full Text Available Type II toxin–antitoxin (TA systems play important roles in bacterial stress survival by regulating cell growth or death. They are highly abundant in cyanobacteria yet remain poorly characterized. Here, we report the identification and regulation of a putative type II TA system from Synechocystis PCC6803, VapBC15. The VapBC15 system is encoded by the chromosomal operon vapBC15. Exogenous expression of VapC15 dramatically arrested cell growth of Escherichia coli and reduced the numbers of colony-forming units (CFU. The VapC15 toxicity could be which was counteracted neutralized by simultaneous or delayed production of VapB15. Biochemical analysis demonstrated the formation of VapB15-VapC15 complexes by the physical interaction between VapB15 and VapC15. Notably, the VapB15 antitoxin up-regulated the transcription of the vapBC15 operon by directly binding to the promoter region, and the VapC15 toxin abolished the up-regulatory effect by destabilizing the binding. Moreover, VapB15 can be degraded by the proteases Lons and ClpXP2s from Synechocystis PCC6803, thus activating the latent toxicity of VapBC15. These findings suggest that VapBC15 represents a genuine TA system that utilizes a distinct mechanism to regulate toxin activity.

  19. Flux Balance Analysis of Cyanobacterial Metabolism.The Metabolic Network of Synechocystis sp. PCC 6803

    Czech Academy of Sciences Publication Activity Database

    Knoop, H.; Gründel, M.; Zilliges, Y.; Lehmann, R.; Hoffmann, S.; Lockau, W.; Steuer, Ralf

    2013-01-01

    Roč. 9, č. 6 (2013), e1003081-e1003081 ISSN 1553-7358 R&D Projects: GA MŠk(CZ) EE2.3.20.0256 Institutional support: RVO:67179843 Keywords : SP STRAIN PCC-6803 * SP ATCC 51142 * photoautotrophic metabolism * anacystis-nidulans * reconstructions * pathway * plants * models * growth Subject RIV: EI - Biotechnology ; Bionics Impact factor: 4.829, year: 2013

  20. Transgenic expression of delta-6 and delta-15 fatty acid desaturases enhances omega-3 polyunsaturated fatty acid accumulation in Synechocystis sp. PCC6803.

    Science.gov (United States)

    Chen, Gao; Qu, Shujie; Wang, Qiang; Bian, Fei; Peng, Zhenying; Zhang, Yan; Ge, Haitao; Yu, Jinhui; Xuan, Ning; Bi, Yuping; He, Qingfang

    2014-03-01

    Polyunsaturated fatty acids (PUFAs), which contain two or more double bonds in their backbone, are the focus of intensive global research, because of their nutritional value, medicinal applications, and potential use as biofuel. However, the ability to produce these economically important compounds is limited, because it is both expensive and technically challenging to separate omega-3 polyunsaturated fatty acids (ω-3 PUFAs) from natural oils. Although the biosynthetic pathways of some plant and microalgal ω-3 PUFAs have been deciphered, current understanding of the correlation between fatty acid desaturase content and fatty acid synthesis in Synechocystis sp. PCC6803 is incomplete. We constructed a series of homologous vectors for the endogenous and exogenous expression of Δ6 and Δ15 fatty acid desaturases under the control of the photosynthesis psbA2 promoter in transgenic Synechocystis sp. PCC6803. We generated six homologous recombinants, harboring various fatty acid desaturase genes from Synechocystis sp. PCC6803, Gibberella fujikuroi and Mortierella alpina. These lines produced up to 8.9 mg/l of α-linolenic acid (ALA) and 4.1 mg/l of stearidonic acid (SDA), which are more than six times the corresponding wild-type levels, at 20°C and 30°C. Thus, transgenic expression of Δ6 and Δ15 fatty acid desaturases enhances the accumulation of specific ω-3 PUFAs in Synechocystis sp. PCC6803. In the blue-green alga Synechocystis sp. PCC6803, overexpression of endogenous and exogenous genes encoding PUFA desaturases markedly increased accumulation of ALA and SDA and decreased accumulation of linoleic acid and γ-linolenic acid. This study lays the foundation for increasing the fatty acid content of cyanobacteria and, ultimately, for producing nutritional and medicinal products with high levels of essential ω-3 PUFAs.

  1. Degradation of phycobilisomes in Synechocystis sp. PCC6803: evidence for essential formation of an NblA1/NblA2 heterodimer and its codegradation by A Clp protease complex.

    Science.gov (United States)

    Baier, Antje; Winkler, Wiebke; Korte, Thomas; Lockau, Wolfgang; Karradt, Anne

    2014-04-25

    When cyanobacteria acclimate to nitrogen deficiency, they degrade their large (3-5-MDa), light-harvesting complexes, the phycobilisomes. This massive, yet specific, intracellular degradation of the pigmented phycobiliproteins causes a color change of cyanobacterial cultures from blue-green to yellow-green, a process referred to as chlorosis or bleaching. Phycobilisome degradation is induced by expression of the nblA gene, which encodes a protein of ~7 kDa. NblA most likely acts as an adaptor protein that guides a Clp protease to the phycobiliproteins, thereby initiating the degradation process. Most cyanobacteria and red algae possess just one nblA-homologous gene. As an exception, the widely used "model organism" Synechocystis sp. PCC6803 expresses two such genes, nblA16803 and nblA26803, both of whose products are required for phycobilisome degradation. Here, we demonstrate that the two NblA proteins heterodimerize in vitro and in vivo using pull-down assays and a Förster energy-transfer approach, respectively. We further show that the NblA proteins form a ternary complex with ClpC (the HSP100 chaperone partner of Clp proteases) and phycobiliproteins in vitro. This complex is susceptible to ATP-dependent degradation by a Clp protease, a finding that supports a proposed mechanism of the degradation process. Expression of the single nblA gene encoded by the genome of the N2-fixing, filamentous cyanobacterium Nostoc sp. PCC7120 in the nblA1/nblA2 mutant of Synechocystis sp. PCC6803 induced phycobilisome degradation, suggesting that the function of the NblA heterodimer of Synechocystis sp. PCC6803 is combined in the homodimeric protein of Nostoc sp. PCC7120.

  2. The non-coding RNA Ncr0700/PmgR1 is required for photomixotrophic growth and the regulation of glycogen accumulation in the cyanobacterium Synechocystis sp. PCC 6803

    DEFF Research Database (Denmark)

    de Porcellinis, Alice Jara; Klähn, Stephan; Rosgaard, Lisa

    2016-01-01

    activity and possible factors acting downstream of PmgA are unknown. Here, a genome-wide microarray analysis of a ΔpmgA strain identified the expression of 36 protein-coding genes and 42 non-coding transcripts as significantly altered. From these, the non-coding RNA Ncr0700 was identified as the transcript...... most strongly reduced in abundance. Ncr0700 is widely conserved among cyanobacteria. In Synechocystis its expression is inversely correlated with light intensity. Similarly to a ΔpmgA mutant, a Δncr0700 deletion strain showed an approximately 2-fold increase in glycogen content under photoautotrophic...

  3. Increased bioplastic production with an RNA polymerase sigma factor SigE during nitrogen starvation in Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Osanai, Takashi; Numata, Keiji; Oikawa, Akira; Kuwahara, Ayuko; Iijima, Hiroko; Doi, Yoshiharu; Tanaka, Kan; Saito, Kazuki; Hirai, Masami Yokota

    2013-12-01

    Because cyanobacteria directly harvest CO2 and light energy, their carbon metabolism is important for both basic and applied sciences. Here, we show that overexpression of the sigma factor sigE in Synechocystis sp. PCC 6803 widely changes sugar catabolism and increases production of the biodegradable polyester polyhydroxybutyrate (PHB) during nitrogen starvation. sigE overexpression elevates the levels of proteins implicated in glycogen catabolism, the oxidative pentose phosphate pathway, and polyhydroxyalkanoate biosynthesis. PHB accumulation is enhanced by sigE overexpression under nitrogen-limited conditions, yet the molecular weights of PHBs synthesized by the parental glucose-tolerant and sigE overexpression strain are similar. Although gene expression induced by nitrogen starvation is changed and other metabolites (such as GDP-mannose and citrate) accumulate under sigE overexpression, genetic engineering of this sigma factor altered the metabolic pathway from glycogen to PHB during nitrogen starvation.

  4. Structural and biochemical characterization of MCAT from photosynthetic microorganism Synechocystis sp. PCC 6803 reveal its stepwise catalytic mechanism.

    Science.gov (United States)

    Liu, Yinghui; Feng, Yanbin; Wang, Yayue; Li, Xia; Cao, Xupeng; Xue, Song

    2015-02-13

    Malonyl-coenzyme A: acyl-carrier protein transacylase (MCAT) catalyzes the transfer of malonyl group from malonyl-CoA to the holo-acyl carrier protein (Holo-ACP), yielding malonyl-ACP. The overall reaction has been extensively studied in heterotrophic microorganisms, while its mechanism in photosynthetic autotrophs as well as the stepwise reaction information remains unclear. Here the 2.42 Å crystal structure of MCAT from photosynthetic microorganism Synechocystis sp. PCC 6803 is presented. It demonstrates that Arg113, Ser88 and His188 constitute catalytic triad. The second step involved ACP-MCAT-malonyl intermediate is speed-limited instead of the malonyl-CoA-MCAT intermediate in the first step. Therefore His87, Arg113 and Ser88 render different contributions for the two intermediates. Additionally, S88T mutant initializes the reaction by H87 deprotonating S88T which is different from the wild type. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Metabolic Engineering of Light and Dark Biochemical Pathways in Wild-Type and Mutant Strains of Synechocystis PCC 6803 for Maximal, 24-Hour Production of Hydrogen Gas

    Energy Technology Data Exchange (ETDEWEB)

    Ely, Roger L.; Chaplen, Frank W.R.

    2014-03-11

    This project used the cyanobacterial species Synechocystis PCC 6803 to pursue two lines of inquiry, with each line addressing one of the two main factors affecting hydrogen (H2) production in Synechocystis PCC 6803: NADPH availability and O2 sensitivity. H2 production in Synechocystis PCC 6803 requires a very high NADPH:NADP+ ratio, that is, the NADP pool must be highly reduced, which can be problematic because several metabolic pathways potentially can act to raise or lower NADPH levels. Also, though the [NiFe]-hydrogenase in PCC 6803 is constitutively expressed, it is reversibly inactivated at very low O2 concentrations. Largely because of this O2 sensitivity and the requirement for high NADPH levels, a major portion of overall H2 production occurs under anoxic conditions in the dark, supported by breakdown of glycogen or other organic substrates accumulated during photosynthesis. Also, other factors, such as N or S limitation, pH changes, presence of other substances, or deletion of particular respiratory components, can affect light or dark H2 production. Therefore, in the first line of inquiry, under a number of culture conditions with wild type (WT) Synechocystis PCC 6803 cells and a mutant with impaired type I NADPH-dehydrogenase (NDH-1) function, we used H2 production profiling and metabolic flux analysis, with and without specific inhibitors, to examine systematically the pathways involved in light and dark H2 production. Results from this work provided rational bases for metabolic engineering to maximize photobiological H2 production on a 24-hour basis. In the second line of inquiry, we used site-directed mutagenesis to create mutants with hydrogenase enzymes exhibiting greater O2 tolerance. The research addressed the following four tasks: 1. Evaluate the effects of various culture conditions (N, S, or P limitation; light/dark; pH; exogenous organic carbon) on H2 production profiles of WT cells and an NDH-1 mutant; 2. Conduct metabolic flux analyses for

  6. Subunit composition of CP43-less photosystem II complexes of Synechocystis sp. PCC 6803: implications for the assembly and repair of photosystem II.

    Science.gov (United States)

    Boehm, M; Yu, J; Reisinger, V; Beckova, M; Eichacker, L A; Schlodder, E; Komenda, J; Nixon, P J

    2012-12-19

    Photosystem II (PSII) mutants are useful experimental tools to trap potential intermediates involved in the assembly of the oxygen-evolving PSII complex. Here, we focus on the subunit composition of the RC47 assembly complex that accumulates in a psbC null mutant of the cyanobacterium Synechocystis sp. PCC 6803 unable to make the CP43 apopolypeptide. By using native gel electrophoresis, we showed that RC47 is heterogeneous and mainly found as a monomer of 220 kDa. RC47 complexes co-purify with small Cab-like proteins (ScpC and/or ScpD) and with Psb28 and its homologue Psb28-2. Analysis of isolated His-tagged RC47 indicated the presence of D1, D2, the CP47 apopolypeptide, plus nine of the 13 low-molecular-mass (LMM) subunits found in the PSII holoenzyme, including PsbL, PsbM and PsbT, which lie at the interface between the two momomers in the dimeric holoenzyme. Not detected were the LMM subunits (PsbK, PsbZ, Psb30 and PsbJ) located in the vicinity of CP43 in the holoenzyme. The photochemical activity of isolated RC47-His complexes, including the rate of reduction of P680(+), was similar to that of PSII complexes lacking the Mn(4)CaO(5) cluster. The implications of our results for the assembly and repair of PSII in vivo are discussed.

  7. Development of a high-frequency in vivo transposon mutagenesis system for Synechocystis sp. PCC 6803 and Synechococcus elongatus PCC 7942.

    Science.gov (United States)

    Watabe, Kazuyuki; Mimuro, Mamoru; Tsuchiya, Tohru

    2014-11-01

    Synechocystis sp. PCC 6803 (Synechocystis) is the first sequenced photosynthetic organism and has two advantages: natural transformation and light-activated heterotrophic growth. Such characteristics have mainly promoted reverse genetic analysis in this organism, however, to date approximately 50% of genes are still annotated as 'unknown protein' or 'hypothetical protein'. Therefore, forward genetic analysis is required for the identification of significant genes responsible for photosynthesis and other physiological phenomena among the genes of unknown function. The in vivo transposon mutagenesis system is one of the major methods for random mutagenesis. However, present in vivo transposon mutagenesis systems for cyanobacteria face problems such as relatively low frequency of transposition and repeated transposition in the host cells. In this study, we constructed vectors based on a mini-Tn5-derived vector that was designed to prevent repeated transposition. Our vectors carry a hyperactive transposase and optimized recognition sequence of transposase, which were reported to enhance frequency of transposition. Using the vector, we succeeded in highly frequent transposition (9×10(-3) per recipient cell) in Synechocystis. Transposon insertion sites of 10 randomly selected mutants indicated that the insertion sites spread throughout the genome with low sequence dependency. Furthermore, one of the 10 mutants exhibited the slow-growing phenotype, and the mutant was functionally complemented by using our expression vector. Our system also worked with another model cyanobacterium, Synechococcus elongatus PCC 7942, with high frequency. These results indicate that the developed system can be applied to the forward genetic analysis of a broad range of cyanobacteria. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  8. Accumulation of the D2 Protein Is a Key Regulatory Step for Assembly of the Photosystem II Reaction Center Complex in Synechocystis PCC 6803

    Czech Academy of Sciences Publication Activity Database

    Komenda, Josef; Reisinger, V.; Muller, B. Ch.; Dobáková, Marika; Granvogl, B.; Eichacker, L. A.

    2004-01-01

    Roč. 279, č. 47 (2004), s. 48620-48629 ISSN 0021-9258 R&D Projects: GA MŠk LN00A141 Grant - others:GA Deutsche Forschungsgemeinschaft Grants(DE) SFB TR1; GA Deutsche Forschungsgemeinschaft Grants(DE) SFB 594 Institutional research plan: CEZ:AV0Z5020903 Keywords : synechocystis PCC 6803 * D2 protein * photosystem PSII Subject RIV: EE - Microbiology, Virology Impact factor: 6.355, year: 2004

  9. The FtsH protease slr0228 is important for quality control of photosystem II in the thylakoid membrane of Synechocystis sp. PCC 6803

    Czech Academy of Sciences Publication Activity Database

    Komenda, Josef; Barker, M.; Kuviková, Stanislava; de Vries, R.; Mullineaux, C.W.; Tichý, Martin; Nixon, P.

    2006-01-01

    Roč. 281, č. 2 (2006), s. 1145-1151 ISSN 0021-9258 R&D Projects: GA ČR GA203/04/0800; GA MŠk LN00A141 Institutional research plan: CEZ:AV0Z50200510 Keywords : photosystem II * synechocystis sp. pcc 6803 * ftsh protease Subject RIV: EE - Microbiology, Virology Impact factor: 5.808, year: 2006

  10. Reconstruction and comparison of the metabolic potential of cyanobacteria Cyanothece sp. ATCC 51142 and Synechocystis sp. PCC 6803.

    Directory of Open Access Journals (Sweden)

    Rajib Saha

    Full Text Available Cyanobacteria are an important group of photoautotrophic organisms that can synthesize valuable bio-products by harnessing solar energy. They are endowed with high photosynthetic efficiencies and diverse metabolic capabilities that confer the ability to convert solar energy into a variety of biofuels and their precursors. However, less well studied are the similarities and differences in metabolism of different species of cyanobacteria as they pertain to their suitability as microbial production chassis. Here we assemble, update and compare genome-scale models (iCyt773 and iSyn731 for two phylogenetically related cyanobacterial species, namely Cyanothece sp. ATCC 51142 and Synechocystis sp. PCC 6803. All reactions are elementally and charge balanced and localized into four different intracellular compartments (i.e., periplasm, cytosol, carboxysome and thylakoid lumen and biomass descriptions are derived based on experimental measurements. Newly added reactions absent in earlier models (266 and 322, respectively span most metabolic pathways with an emphasis on lipid biosynthesis. All thermodynamically infeasible loops are identified and eliminated from both models. Comparisons of model predictions against gene essentiality data reveal a specificity of 0.94 (94/100 and a sensitivity of 1 (19/19 for the Synechocystis iSyn731 model. The diurnal rhythm of Cyanothece 51142 metabolism is modeled by constructing separate (light/dark biomass equations and introducing regulatory restrictions over light and dark phases. Specific metabolic pathway differences between the two cyanobacteria alluding to different bio-production potentials are reflected in both models.

  11. The deg proteases protect Synechocystis sp. PCC 6803 during heat and light stresses but are not essential for removal of damaged D1 protein during the photosystem two repair cycle.

    Science.gov (United States)

    Barker, Myles; de Vries, Remco; Nield, Jon; Komenda, Josef; Nixon, Peter J

    2006-10-13

    Members of the DegP/HtrA (or Deg) family of proteases are found widely in nature and play an important role in the proteolysis of misfolded and damaged proteins. As yet, their physiological role in oxygenic photosynthetic organisms is unclear, although it has been widely speculated that they participate in the degradation of the photodamaged D1 subunit in the photosystem two complex (PSII) repair cycle, which is needed to maintain PSII activity in both cyanobacteria and chloroplasts. We have examined the role of the three Deg proteases found in the cyanobacterium Synechocystis sp. PCC 6803 through analysis of double and triple insertion mutants. We have discovered that these proteases show overlap in function and are involved in a number of key physiological responses ranging from protection against light and heat stresses to phototaxis. In previous work, we concluded that the Deg proteases played either a direct or an indirect role in PSII repair in a glucose-tolerant version of Synechocystis 6803 (Silva, P., Choi, Y. J., Hassan, H. A., and Nixon, P. J. (2002) Philos. Trans. R. Soc. Lond. B Biol. Sci. 357, 1461-1467). In this work, we have now been able to demonstrate unambiguously, using a triple deg mutant created in the wild type strain of Synechocystis 6803, that the Deg proteases are not obligatory for PSII repair and D1 degradation. We therefore conclude that although the Deg proteases are needed for photoprotection of Synechocystis sp. PCC 6803, they do not play an essential role in D1 turnover and PSII repair in vivo.

  12. N-Terminal Lipid Modification Is Required for the Stable Accumulation of CyanoQ in Synechocystis sp. PCC 6803.

    Directory of Open Access Journals (Sweden)

    Andrea D Juneau

    Full Text Available The CyanoQ protein has been demonstrated to be a component of cyanobacterial Photosystem II (PS II, but there exist a number of outstanding questions concerning its physical association with the complex. CyanoQ is a lipoprotein; upon cleavage of its transit peptide by Signal Peptidase II, which targets delivery of the mature protein to the thylakoid lumenal space, the N-terminal cysteinyl residue is lipid-modified. This modification appears to tether this otherwise soluble component to the thylakoid membrane. To probe the functional significance of the lipid anchor, mutants of the CyanoQ protein have been generated in Synechocystis sp. PCC 6803 to eliminate the N-terminal cysteinyl residue, preventing lipid modification. Substitution of the N-terminal cysteinyl residue with serine (Q-C22S resulted in a decrease in the amount of detectable CyanoQ protein to 17% that of the wild-type protein. Moreover, the physical properties of the accumulated Q-C22S protein were consistent with altered processing of the CyanoQ precursor. The Q-C22S protein was shifted to a higher apparent molecular mass and partitioned in the hydrophobic phase in TX-114 phase-partitioning experiments. These results suggest that the hydrophobic N-terminal 22 amino acids were not properly cleaved by a signal peptidase. Substitution of the entire CyanoQ transit peptide with the transit peptide of the soluble lumenal protein PsbO yielded the Q-SS mutant and resulted in no detectable accumulation of the modified CyanoQ protein. Finally, the CyanoQ protein was present at normal amounts in the PS II mutant strains ΔpsbB and ΔpsbO, indicating that an association with PS II was not a prerequisite for stable CyanoQ accumulation. Together these results indicate that CyanoQ accumulation in Synechocystis sp. PCC 6803 depends on the presence of the N-terminal lipid anchor, but not on the association of CyanoQ with the PS II complex.

  13. comparative transcriptomics between Synechococcus PCC 7942 and Synechocystis PCC 6803 provide insights into mechanisms of adaptation to stress.

    Energy Technology Data Exchange (ETDEWEB)

    Konstantinos, Billis [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); European Bioinformatics Inst., Hinxton, Cambridge (United Kingdom). European Molecular Biology Lab.; Aristotle Univ., Thessaloniki (Greece). Dept. of Genetics; Billini, Maria [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Max Planck Inst. for Terrestrial Microbiology, Marburg (Germany); Tripp, Harry J. [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Kyrpides, Nikos C. [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Mavrommatis, Konstantinos [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Celgene Corp, San Francisco, CA (United States)

    2014-03-21

    Background: Synechococcus sp. PCC 7942 and Synechocystis sp. PCC 6803 are model cyanobacteria from which the metabolism and adaptive responses of other cyanobacteria are inferred. Here we report the gene expression response of these two strains to a variety of nutrient and environmental stresses of varying duration, using transcriptomics. Our data comprise both stranded and 5? enriched libraries in order to elucidate many aspects of the transcriptome. Results: Both organisms were exposed to stress conditions due to nutrient deficiency (inorganic carbon) or change of environmental conditions (salinity, temperature, pH, light) sampled at 1 and 24 hours after the application of stress. The transcriptome profile of each strain revealed similarities and differences in gene expression for photosynthetic and respiratory electron transport chains and carbon fixation. Transcriptome profiles also helped us improve the structural annotation of the genome and identify possible missed genes (including anti-sense) and determine transcriptional units (operons). Finally, we predicted association of proteins of unknown function biochemical pathways by associating them to well-characterized ones based on their transcript levels correlation. Conclusions: Overall, this study results an informative annotation of those species and the comparative analysis of the response of the two organisms revealed similarities but also significant changes in the way they respond to external stress and the duration of the response

  14. Effects of selected electron transport chain inhibitors on 24-h hydrogen production by Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Burrows, Elizabeth H; Chaplen, Frank W R; Ely, Roger L

    2011-02-01

    One factor limiting biosolar hydrogen (H(2)) production from cyanobacteria is electron availability to the hydrogenase enzyme. In order to optimize 24-h H(2) production this study used Response Surface Methodology and Q2, an optimization algorithm, to investigate the effects of five inhibitors of the photosynthetic and respiratory electron transport chains of Synechocystis sp. PCC 6803. Over 3 days of diurnal light/dark cycling, with the optimized combination of 9.4 mM KCN (3.1 μmol 10(10) cells(-1)) and 1.5 mM malonate (0.5 μmol 10(10) cells(-1)) the H(2) production was 30-fold higher, in EHB-1 media previously optimized for nitrogen (N), sulfur (S), and carbon (C) concentrations (Burrows et al., 2008). In addition, glycogen concentration was measured over 24 h with two light/dark cycling regimes in both standard BG-11 and EHB-1 media. The results suggest that electron flow as well as glycogen accumulation should be optimized in systems engineered for maximal H(2) output. Copyright © 2010 Elsevier Ltd. All rights reserved.

  15. Flavodiiron proteins in oxygenic photosynthetic organisms: photoprotection of photosystem II by Flv2 and Flv4 in Synechocystis sp. PCC 6803.

    Directory of Open Access Journals (Sweden)

    Pengpeng Zhang

    Full Text Available BACKGROUND: Flavodiiron proteins (FDPs comprise a group of modular enzymes that function in oxygen and nitric oxide detoxification in Bacteria and Archaea. The FDPs in cyanobacteria have an extra domain as compared to major prokaryotic enzymes. The physiological role of cyanobacteria FDPs is mostly unknown. Of the four putative flavodiiron proteins (Flv1-4 in the cyanobacterium Synechocystis sp. PCC 6803, a physiological function in Mehler reaction has been suggested for Flv1 and Flv3. PRINCIPAL FINDINGS: We demonstrate a novel and crucial function for Flv2 and Flv4 in photoprotection of photosystem II (PSII in Synechocystis. It is shown that the expression of Flv2 and Flv4 is high under air level of CO(2 and negligible at elevated CO(2. Moreover, the rate of accumulation of flv2 and flv4 transcripts upon shift of cells from high to low CO(2 is strongly dependent on light intensity. Characterization of FDP inactivation mutants of Synechocystis revealed a specific decline in PSII centers and impaired translation of the D1 protein in Delta flv2 and Delta flv4 when grown at air level CO(2 whereas at high CO(2 the Flvs were dispensable. Delta flv2 and Delta flv4 were also more susceptible to high light induced inhibition of PSII than WT or Delta flv1 and Delta flv3. SIGNIFICANCE: Analysis of published sequences revealed the presence of cyanobacteria-like FDPs also in some oxygenic photosynthetic eukaryotes like green algae, mosses and lycophytes. Our data provide evidence that Flv2 and Flv4 have an important role in photoprotection of water-splitting PSII against oxidative stress when the cells are acclimated to air level CO(2. It is conceivable that the function of FDPs has changed during evolution from protection against oxygen in anaerobic microbes to protection against reactive oxygen species thus making the sustainable function of oxygen evolving PSII possible. Higher plants lack FDPs and distinctly different mechanisms have evolved for

  16. Metabolic flux of the oxidative pentose phosphate pathway under low light conditions in Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Ueda, Kentaro; Nakajima, Tsubasa; Yoshikawa, Katsunori; Toya, Yoshihiro; Matsuda, Fumio; Shimizu, Hiroshi

    2018-02-27

    The role of the oxidative pentose phosphate pathway (oxPPP) in Synechocystis sp. PCC 6803 under mixotrophic conditions was investigated by 13 C metabolic flux analysis. Cells were cultured under low (10 μmol m -2  s -1 ) and high light intensities (100 μmol m -2  s -1 ) in the presence of glucose. The flux of CO 2 fixation by ribulose bisphosphate carboxylase/oxygenase under the high light condition was approximately 3-fold higher than that under the low light condition. Although no flux of the oxPPP was observed under the high light condition, flux of 0.08-0.19 mmol gDCW -1  h -1 in the oxPPP was observed under the low light condition. The balance between the consumption and production of NADPH suggested that approximately 10% of the total NADPH production was generated by the oxPPP under the low light condition. The growth phenotype of a mutant with deleted zwf, which encodes glucose-6-phosphate dehydrogenase in the oxPPP, was compared to that of the parental strain under low and high light conditions. Growth of the Δzwf mutant nearly stopped during the late growth phase under the low light condition, whereas the growth rates of the two strains were identical under the high light condition. These results indicate that NADPH production in the oxPPP is essential for anabolism under low light conditions. The oxPPP appears to play an important role in producing NADPH from glucose and ATP to compensate for NADPH shortage under low light conditions. Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  17. Photoautotrophic Polyhydroxybutyrate Granule Formation Is Regulated by Cyanobacterial Phasin PhaP in Synechocystis sp. Strain PCC 6803

    Science.gov (United States)

    Hauf, Waldemar; Watzer, Björn; Roos, Nora; Klotz, Alexander

    2015-01-01

    Cyanobacteria are photoautotrophic microorganisms which fix atmospheric carbon dioxide via the Calvin-Benson cycle to produce carbon backbones for primary metabolism. Fixed carbon can also be stored as intracellular glycogen, and in some cyanobacterial species like Synechocystis sp. strain PCC 6803, polyhydroxybutyrate (PHB) accumulates when major nutrients like phosphorus or nitrogen are absent. So far only three enzymes which participate in PHB metabolism have been identified in this organism, namely, PhaA, PhaB, and the heterodimeric PHB synthase PhaEC. In this work, we describe the cyanobacterial PHA surface-coating protein (phasin), which we term PhaP, encoded by ssl2501. Translational fusion of Ssl2501 with enhanced green fluorescent protein (eGFP) showed a clear colocalization to PHB granules. A deletion of ssl2501 reduced the number of PHB granules per cell, whereas the mean PHB granule size increased as expected for a typical phasin. Although deletion of ssl2501 had almost no effect on the amount of PHB, the biosynthetic activity of PHB synthase was negatively affected. Secondary-structure prediction and circular dichroism (CD) spectroscopy of PhaP revealed that the protein consists of two α-helices, both of them associating with PHB granules. Purified PhaP forms oligomeric structures in solution, and both α-helices of PhaP contribute to oligomerization. Together, these results support the idea that Ssl2501 encodes a cyanobacterial phasin, PhaP, which regulates the surface-to-volume ratio of PHB granules. PMID:25911471

  18. Identification of a New Target slr0946 of the Response Regulator Sll0649 Involving Cadmium Tolerance in Synechocystis sp. PCC 6803

    Directory of Open Access Journals (Sweden)

    Tao Sun

    2017-08-01

    Full Text Available Survival of photosynthetic cyanobacteria is challenged by environmental contaminations like heavy metals. Among them, deciphering the regulatory mechanisms for cadmium (Cd in cyanobacteria would facilitate the construction of Cd-resistant strains. In this study, the DNA-Affinity-Purified-chromatin immunoprecipitation assay was employed to identify the direct targets of Sll0649, which was a Cd2+-related response regulator identified in our previous work in model cyanobacteria Synechocystis sp. PCC 6803. As a result, the promoter region of slr0946 encoding the arsenate reductase was enriched fourfolds by quantitative real time PCR analysis. Further, deletion of slr0946 led to a sensitive phenotype to Cd2+ stress compared with the wild type (WT and the sensitive phenotype of Δslr0946 could be rescued by complementation assay via introducing slr0946 back into Δslr0946. Finally, individually overexpression of slr0946 as well as two Cd2+-related genes identified priviously (i.e., sll1598 and slr0798 in WT could significantly improve the tolerance of Synechocystis sp. PCC 6803 to Cd2+. This study provided a better understanding of the tolerance mechanism to Cd2+ in cyanobacteria and also feasible strategies for tolerance modifications to heavy metals in the future.

  19. The cyanobacterial homologue of HCF136/YCF48 is a component of an early photosystem II assembly complex and is important for both the efficient assembly and repair of photosystem II in Synechocystis sp. PCC 6803

    Czech Academy of Sciences Publication Activity Database

    Komenda, Josef; Mickelsen, J.; Tichý, Martin; Prášil, Ondřej; Eichacker, L. A.; Nixon, P. J.

    2008-01-01

    Roč. 283, č. 33 (2008), s. 22390-22399 ISSN 0021-9258 R&D Projects: GA ČR GA206/06/0322; GA AV ČR IAA400200801 Institutional research plan: CEZ:AV0Z50200510 Keywords : photosystem II * algae * synechocystis sp. pcc 6803 Subject RIV: EE - Microbiology, Virology Impact factor: 5.520, year: 2008

  20. Kinetic analysis of cysteine desulfurase CD0387 from Synechocystis sp. PCC 6803: formation of the persulfide intermediate.

    Science.gov (United States)

    Behshad, Elham; Bollinger, J Martin

    2009-12-22

    Stopped-flow absorption and isotope effect experiments have been used to dissect the mechanism of formation of the enzyme cysteinyl persulfide intermediate in the reaction of a cysteine desulfurase (CD), CD0387 from Synechocystis sp. strain PCC 6803. Seven accumulating intermediates have been identified and tentatively mapped onto the CD chemical mechanism originally proposed by Dean, White, and co-workers [Zheng, L., White, R. H., Cash, V. L., and Dean, D. R. (1994) Biochemistry 33, 4714-4720]. The first intermediate with lambda(max) approximately 350 nm is assigned as either a gem-diamine complex or a thiol adduct formed by nucleophilic attack of either the amine group or the sulfhydryl group of the substrate on the internal aldimine form of the pyridoxal 5'-phosphate (PLP) cofactor. The second intermediate, with absorption features at approximately 417 and approximately 340 nm, is assigned as Cys aldimine and Cys ketimine forms in rapid equilibrium. In agreement with this assignment, a significant substrate alpha-deuterium equilibrium isotope effect ((2)H-EIE) favoring the aldimine form (417 nm) is observed in the second state produced in either wild-type CD0387 or the inactive C326A variant protein, which lacks the nucleophilic cysteine residue and is thus unable to proceed beyond this state unless "rescued" by a high concentration of an exogenous thiol. The third intermediate has an additional approximately 506 nm feature, characteristic of a quinonoid form, along with the features of the previous state. Its assignment as Ala aldimine, quinonoid, and ketimine forms in rapid equilibrium, which associates its formation with C-S bond cleavage and persulfide formation, is supported by its failure to develop in the C326A variant and the normal kinetic isotope effect ((2)H-KIE) on its formation, which is similar in magnitude to the (2)H-EIE disfavoring Cys-ketimine (from which the third state forms) in the second state. Decay of the Ala quinonoid absorption is

  1. The Cyanobacterial Ribosomal-Associated Protein LrtA Is Involved in Post-Stress Survival in Synechocystis sp. PCC 6803.

    Directory of Open Access Journals (Sweden)

    Carla V Galmozzi

    Full Text Available A light-repressed transcript encodes the LrtA protein in cyanobacteria. We show that half-life of lrtA transcript from Synechocystis sp. PCC 6803 is higher in dark-treated cells as compared to light-grown cells, suggesting post-transcriptional control of lrtA expression. The lrtA 5´ untranslated leader region is involved in that darkness-dependent regulation. We also found that Synechocystis sp. PCC 6803 LrtA is a ribosome-associated protein present in both 30S and 70S ribosomal particles. In order to investigate the function of this protein we have constructed a deletion mutant of the lrtA gene. Cells lacking LrtA (∆lrtA had significantly lower amount of 70S particles and a greater amount of 30S and 50S particles, suggesting a role of LrtA in stabilizing 70S particles. Synechocystis strains with different amounts of LrtA protein: wild-type, ∆lrtA, and LrtAS (overexpressing lrtA showed no differences in their growth rate under standard laboratory conditions. However, a clear LrtA dose-dependent effect was observed in the presence of the antibiotic tylosin, being the LrtAS strains the most sensitive. Similar results were obtained under hyperosmotic stress caused by sorbitol. Conversely, after prolonged periods of starvation, ∆lrtA strains were delayed in their growth with respect to the wild-type and the LrtAS strains. A positive role of LrtA protein in post-stress survival is proposed.

  2. Lack of Phosphatidylglycerol Inhibits Chlorophyll Biosynthesis at Multiple Sites and Limits Chlorophyllide Reutilization in Synechocystis sp Strain PCC 6803

    Czech Academy of Sciences Publication Activity Database

    Kopečná, Jana; Pilný, Jan; Krynická, Vendula; Tomčala, Aleš; Kis, M.; Gombos, Z.; Komenda, Josef; Sobotka, Roman

    2015-01-01

    Roč. 169, č. 2 (2015), s. 1307-1317 ISSN 0032-0889 R&D Projects: GA MŠk LO1416; GA MŠk EE2.3.30.0059; GA ČR GBP501/12/G055 Institutional support: RVO:61388971 ; RVO:60077344 Keywords : II REACTION-CENTER * PHOTOSYSTEM-II * SP PCC-6803 Subject RIV: CE - Biochemistry Impact factor: 6.280, year: 2015

  3. Metabolic Flux Analysis of the Synechocystis sp. PCC 6803 ΔnrtABCD Mutant Reveals a Mechanism for Metabolic Adaptation to Nitrogen-Limited Conditions.

    Science.gov (United States)

    Nakajima, Tsubasa; Yoshikawa, Katsunori; Toya, Yoshihiro; Matsuda, Fumio; Shimizu, Hiroshi

    2017-03-01

    Metabolic flux redirection during nitrogen-limited growth was investigated in the Synechocystis sp. PCC 6803 glucose-tolerant (GT) strain under photoautotrophic conditions by isotopically non-stationary metabolic flux analysis (INST-MFA). A ΔnrtABCD mutant of Synechocystis sp. PCC 6803 was constructed to reproduce phenotypes arising during nitrogen starvation. The ΔnrtABCD mutant and the wild-type GT strain were cultured under photoautotrophic conditions by a photobioreactor. Intracellular metabolites were labeled over a time course using NaH13CO3 as a carbon source. Based on these data, the metabolic flux distributions in the wild-type and ΔnrtABCD cells were estimated by INST-MFA. The wild-type GT and ΔnrtABCD strains displayed similar distribution patterns, although the absolute levels of metabolic flux were lower in ΔnrtABCD. Furthermore, the relative flux levels for glycogen metabolism, anaplerotic reactions and the oxidative pentose phosphate pathway were increased in ΔnrtABCD. This was probably due to the increased expression of enzyme genes that respond to nitrogen depletion. Additionally, we found that the ratio of ATP/NADPH demand increased slightly in the ΔnrtABCD mutant. These results indicated that futile ATP consumption increases under nitrogen-limited conditions because the Calvin-Benson cycle and the oxidative pentose phosphate pathway form a metabolic futile cycle that consumes ATP without CO2 fixation and NADPH regeneration. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  4. Measurement of the mechanical properties of single Synechocystis sp. strain PCC6803 cells in different osmotic concentrations using a robot-integrated microfluidic chip.

    Science.gov (United States)

    Chang, Di; Sakuma, Shinya; Kera, Kota; Uozumi, Nobuyuki; Arai, Fumihito

    2018-03-23

    Synechocystis sp. strain PCC6803 (Synechocystis) is a model microorganism and its mechanosensitive (MS) channels play important roles in its osmoadaptation mechanism. When the osmotic concentration of the culture environment changes, the inner pressure of the cell also changes due to the transportation of water through ion channels. Because the tension in the cell membrane relates to the inner pressure, we expect that the response of the MS channels to an osmotic concentration change could be evaluated by measuring their mechanical properties. Here, we propose a system for the measurement of the mechanical properties of a single Synechocystis cell. We developed a robot-integrated microfluidic chip combined with optical tweezers. The chip has an external actuated pushing probe and a force sensor probe. A single cell was located between the tip of both probes using the optical tweezers and was then deformed using the probes. As a result, we could measure the force and deformation and compare the Young's moduli of two groups: a group of wild type cells and a group of mutant (genetically modified) cells with a defect in the MS channels, at three different osmotic concentrations. The results showed that the Young's modulus of each group changed according to the osmotic concentration, while changes in cell size were too small to be detected. These results confirmed that the proposed evaluation method provides an understanding of the physiological function of MS channels for keeping the cell integrity of microorganisms when the cells are exposed to different external osmotic changes.

  5. Role of phosphatidylglycerol in the function and assembly of Photosystem II reaction center, studied in a cdsA-inactivated PAL mutant strain of Synechocystis sp. PCC6803 that lacks phycobilisomes

    Czech Academy of Sciences Publication Activity Database

    Laczkó-Dobos, H.; Ughy, B.; Tóth, S. Z.; Komenda, Josef; Zsiros, O.; Domonkos, I.; Párducz, A.; Bogos, B.; Komura, M.; Itoh, S.; Gombos, Z.

    2008-01-01

    Roč. 1777, č. 9 (2008), s. 1184-1194 ISSN 0005-2728 R&D Projects: GA AV ČR IAA400200801 Grant - others:HU(HU) OTKA T60109; HU(HU) OTKA T68692 Institutional research plan: CEZ:AV0Z50200510 Keywords : synechocystis sp. pcc6803 * phosphatidylglycerol * photosystem II Subject RIV: EE - Microbiology, Virology Impact factor: 4.447, year: 2008

  6. Improved sugar-free succinate production bySynechocystissp. PCC 6803 following identification of the limiting steps in glycogen catabolism.

    Science.gov (United States)

    Hasunuma, Tomohisa; Matsuda, Mami; Kondo, Akihiko

    2016-12-01

    Succinate produced by microorganisms can replace currently used petroleum-based succinate but typically requires mono- or poly-saccharides as a feedstock. The cyanobacterium Synechocystis sp. PCC6803 can produce organic acids such as succinate from CO 2 not supplemented with sugars under dark anoxic conditions using an unknown metabolic pathway. The TCA cycle in cyanobacteria branches into oxidative and reductive routes. Time-course analyses of the metabolome, transcriptome and metabolic turnover described here revealed dynamic changes in the metabolism of Synechocystis sp. PCC6803 cultivated under dark anoxic conditions, allowing identification of the carbon flow and rate-limiting steps in glycogen catabolism. Glycogen biosynthesized from CO 2 assimilated during periods of light exposure is catabolized to succinate via glycolysis, the anaplerotic pathway, and the reductive TCA cycle under dark anoxic conditions. Expression of the phospho enol pyruvate (PEP) carboxylase gene ( ppc ) was identified as a rate-limiting step in succinate biosynthesis and this rate limitation was alleviated by ppc overexpression, resulting in improved succinate excretion. The sugar-free succinate production was further enhanced by the addition of bicarbonate. In vivo labeling with NaH 13 CO 3 clearly showed carbon incorporation into succinate via the anaplerotic pathway. Bicarbonate is in equilibrium with CO 2 . Succinate production by Synechocystis sp. PCC6803 therefore holds significant promise for CO 2 capture and utilization.

  7. Photosynthetic Electron Transport Involved in PxcA-Dependent Proton Extrusion in Synechocystis sp. Strain PCC6803: Effect of pxcA Inactivation on CO2, HCO3−, and NO3− Uptake

    OpenAIRE

    Sonoda, Masatoshi; Katoh, Hirokazu; Vermaas, Wim; Schmetterer, George; Ogawa, Teruo

    1998-01-01

    The product of pxcA (formerly known as cotA) is involved in light-induced Na+-dependent proton extrusion. In the presence of 2,5-dimethyl-p-benzoquinone, net proton extrusion by Synechocystis sp. strain PCC6803 ceased after 1 min of illumination and a postillumination influx of protons was observed, suggesting that the PxcA-dependent, light-dependent proton extrusion equilibrates with a light-independent influx of protons. A photosystem I (PS I) deletion mutant extruded a large number of prot...

  8. Microbial Carbonate Precipitation by Synechococcus PCC8806, LS0519 and Synechocystis PCC6803 on Concrete Surfaces and in Low Saturation Solution

    Science.gov (United States)

    Zhu, T.; Lin, Y.; Dittrich, M.

    2015-12-01

    Microbial carbonate precipitation (MCP) by cyanobacteria has been recognized in a variety of environment such as freshwater, marine, cave, and even desert. Recently, their calcification potential has been tested in an emerging technology-- bioconcrete. This study is to explore the calcification by three cyanobacteria strains under different environmental conditions. Experiment A was carried out in 2mM NaHCO3 and 5mM CaCl2, with a cell concentration of 107 cells L-1. In experiment B, one side of the concrete surface was treated with bacteria and then immersed in the solution containing 0.4 mM NaHCO3 and 300 mM CaCl2. In experiment A, the pH of the abiotic condition remained constant around 8.55, while that of biotic conditions increased by 0.15 units in the presence of LS0519, and by 0.3 units in the presence of PCC8806 or PCC6803 within 8 hours. Over a period of 30 hours, PCC8806, LS0519 and PCC6803 removed 0.1, 0.12 and 0.2 mM calcium from the solution respectively. After 30 hours, the alkalinity of the solution decreased by 30 mg/L, 10 mg/L and 5 mg/L respectively in the presence of PCC6803, LS0519 and PCC8806. Under scanning electron microscopy (SEM), no precipitate was found in the abiotic condition, while calcium carbonate was associated by all the three strains. Among them, PCC6803 precipitated more carbonates. In experiment B, LS0519 and PCC8806 increased the pH with a value of 0.25, while PCC6803 increased the pH by 0.33 units. SEM shows LS0519 was less likely attached to the concrete surface. Neither did the precipitates on concrete surface differ from that in the abiotic condition. In comparison, PCC8806 and PCC6803 were closely associated with 8-μm porous precipitates. Cells were either found enclosed in precipitates or connecting two precipitates. In conclusion, all the three strains triggered the calcium carbonate precipitation. LS0519 has a little impact on the carbonate precipitation in the solution, but negligent influence on the concrete surface

  9. Strain of Synechocystis PCC 6803 with Aberrant Assembly of Photosystem NN Contains Tandem Duplication of a Large Chromosomal Region

    Czech Academy of Sciences Publication Activity Database

    Tichý, Martin; Bečková, Martina; Kopečná, Jana; Noda, J.; Sobotka, Roman; Komenda, Josef

    2016-01-01

    Roč. 7, May 12 (2016), s. 648 ISSN 1664-462X R&D Projects: GA MŠk(CZ) LO1416 Institutional support: RVO:61388971 Keywords : Synechocystis 6803 * chlorophyll * photosystem I Subject RIV: EE - Microbiology, Virology Impact factor: 4.298, year: 2016

  10. The cry-DASH cryptochrome encoded by the sll1629 gene in the cyanebacterium Synechocystis PCC 6803 is required for Photosystem II repair

    Czech Academy of Sciences Publication Activity Database

    Vass, I.; Kós, Peter B.; Knoppová, Jana; Komenda, Josef; Vass, I. Jr.

    2014-01-01

    Roč. 130, č. 4 (2014), s. 318-326 ISSN 1011-1344 R&D Projects: GA MŠk ED2.1.00/03.0110; GA ČR GBP501/12/G055 Institutional support: RVO:61388971 Keywords : Synechocystis sp. * cyanobacterium * DNA repair Subject RIV: EE - Microbiology, Virology Impact factor: 2.960, year: 2014

  11. Export of Extracellular Polysaccharides Modulates Adherence of the Cyanobacterium Synechocystis

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, ML; Allen, R; Luo, YQ; Curtiss, R

    2013-09-10

    The field of cyanobacterial biofuel production is advancing rapidly, yet we know little of the basic biology of these organisms outside of their photosynthetic pathways. We aimed to gain a greater understanding of how the cyanobacterium Synechocystis PCC 6803 (Synechocystis, hereafter) modulates its cell surface. Such understanding will allow for the creation of mutants that autoflocculate in a regulated way, thus avoiding energy intensive centrifugation in the creation of biofuels. We constructed mutant strains lacking genes predicted to function in carbohydrate transport or synthesis. Strains with gene deletions of slr0977 (predicted to encode a permease component of an ABC transporter), slr0982 (predicted to encode an ATP binding component of an ABC transporter) and slr1610 (predicted to encode a methyltransferase) demonstrated flocculent phenotypes and increased adherence to glass. Upon bioinformatic inspection, the gene products of slr0977, slr0982, and slr1610 appear to function in O-antigen (OAg) transport and synthesis. However, the analysis provided here demonstrated no differences between OAg purified from wild-type and mutants. However, exopolysaccharides (EPS) purified from mutants were altered in composition when compared to wild-type. Our data suggest that there are multiple means to modulate the cell surface of Synechocystis by disrupting different combinations of ABC transporters and/or glycosyl transferases. Further understanding of these mechanisms may allow for the development of industrially and ecologically useful strains of cyanobacteria. Additionally, these data imply that many cyanobacterial gene products may possess as-yet undiscovered functions, and are meritorious of further study.

  12. Mutational analysis of photosystem I of Synechocystis sp. PCC 6803: the role of four conserved aromatic residues in the j-helix of PsaB.

    Directory of Open Access Journals (Sweden)

    Wu Xu

    Full Text Available Photosystem I is the light-driven plastocyanin-ferredoxin oxidoreductase in the photosynthetic electron transfer of cyanobacteria and plants. Two histidyl residues in the symmetric transmembrane helices A-j and B-j provide ligands for the P700 chlorophyll molecules of the reaction center of photosystem I. To determine the role of conserved aromatic residues adjacent to the histidyl molecule in the helix of B-j, we generated six site-directed mutants of the psaB gene in Synechocystis sp. PCC 6803. Three mutant strains with W645C, W643C/A644I and S641C/V642I substitutions could grow photoautotrophically and showed no obvious reduction in the photosystem I activity. Kinetics of P700 re-reduction by plastocyanin remained unaltered in these mutants. In contrast, the strains with H651C/L652M, F649C/G650I and F647C substitutions could not grow under photoautotrophic conditions because those mutants had low photosystem I activity, possibly due to low levels of proteins. A procedure to select spontaneous revertants from the mutants that are incapable to photoautotrophic growth resulted in three revertants that were used in this study. The molecular analysis of the spontaneous revertants suggested that an aromatic residue at F647 and a small residue at G650 may be necessary for maintaining the structural integrity of photosystem I. The (P700⁺-P700 steady-state absorption difference spectrum of the revertant F647Y has a ∼5 nm narrower peak than the recovered wild-type, suggesting that additional hydroxyl group of this revertant may participate in the interaction with the special pair while the photosystem I complexes of the F649C/G650T and H651Q mutants closely resemble the wild-type spectrum. The results presented here demonstrate that the highly conserved residues W645, W643 and F649 are not critical for maintaining the integrity and in mediating electron transport from plastocyanin to photosystem I. Our data suggest that an aromatic residue is

  13. Conserved Chloroplast Open-reading Frame ycf54 Is Required for Activity of the Magnesium Protoporphyrin Monomethylester Oxidative Cyclase in Synechocystis PCC 6803

    Czech Academy of Sciences Publication Activity Database

    Hollingshead, S.; Kopečná, Jana; Jackson, P. J.; Canniffe, D. P.; Davidson, P. A.; Dickman, M. J.; Sobotka, Roman; Hunter, C. N.

    2012-01-01

    Roč. 287, č. 33 (2012), s. 27823-27833 ISSN 0021-9258 R&D Projects: GA ČR GAP501/10/1000; GA MŠk(CZ) ED2.1.00/03.0110 Institutional support: RVO:61388971 Keywords : CHLOROPHYLL ISOCYCLIC RING * RHODOBACTER-SPHAEROIDES * SP PCC-6803 Subject RIV: CE - Biochemistry Impact factor: 4.651, year: 2012

  14. Structural and mutational analysis of band 7 proteins in the cyanobacterium Synechocystis sp. strain PCC 6803

    Czech Academy of Sciences Publication Activity Database

    Boehm, M.; Nield, J.; Zhang, P.; Aro, E.-M.; Komenda, Josef; Nixon, P. J.

    2009-01-01

    Roč. 191, č. 20 (2009), s. 6425-6435 ISSN 0021-9193 R&D Projects: GA AV ČR IAA400200801 Institutional research plan: CEZ:AV0Z50200510 Keywords : BLUE NATIVE ELECTROPHORESIS * PHOTOSYSTEM-II COMPLEX * COLI PLASMA-MEMBRANE Subject RIV: EE - Microbiology, Virology Impact factor: 3.940, year: 2009

  15. Synechocystis

    Science.gov (United States)

    Liang, Feiyan; Lindblad, Peter

    2017-06-01

    The ribulose-1,5-bisphosphate (RuBP) oxygenation reaction catalyzed by Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) is competing with carboxylation, being negative for both energy and carbon balances in photoautotrophic organisms. This makes RuBisCO one of the bottlenecks for oxygenic photosynthesis and carbon fixation. In this study, RuBisCO was overexpressed in the unicellular cyanobacterium Synechocystis PCC 6803. Relative RuBisCO levels in the engineered strains FL50 and FL52 increased 2.1 times and 1.4 times, respectively, and both strains showed increased growth, photosynthesis and in vitro RuBisCO activity. The oxygen evolution rate increased by 54% and 42% on per chlorophyll basis, while the in vitro RuBisCO activity increased by 52% and 8.6%, respectively. The overexpressed RuBisCO were tagged with a FLAG tag, in strain FL50 on the N terminus of the large subunit while in strain FL52 on the C terminus of the small subunit. The presence of a FLAG tag enhanced transcription of the genes encoding RuBisCO, and, with high possibility, also enhanced the initiation of translation or stability of the enzyme. However, when using a streptavidin-binding tag II (strep-tag II), we did not observe a similar effect. Tagged RuBisCO offers an opportunity for further studying RuBisCO expression and stability. Increased levels of RuBisCO can further improve photosynthesis and growth in the cyanobacterium Synechocystis PCC 6803 under certain growth conditions.

  16. Functional Expression of the Arachis hypogaea L. Acyl-ACP Thioesterases AhFatA and AhFatB Enhances Fatty Acid Production in Synechocystis sp. PCC6803

    Directory of Open Access Journals (Sweden)

    Gao Chen

    2017-12-01

    Full Text Available Palmitoleic acid (C16:1 and stearic acid (C18:0 are precursors of polyunsaturated fatty acids, which are the focus of intensive global research due to their nutritional value, medicinal applications, and potential use as biofuel. Acyl-acyl carrier protein (ACP thioesterases are intraplastidial enzymes that determine the types and amounts of fatty acids produced in plants and release fatty acids into the cytosol to be incorporated into glycerolipids. Based on amino acid sequence identity and substrate specificity, these enzymes are classified into two families, FatA and FatB. In this study, we cloned FatA and FatB thioesterases from Arachis hypogaea L. seeds and functionally expressed these genes, both individually and in tandem, in a blue-green alga Synechocystis sp. PCC6803. The heterologous expression of these genes in Synechocystis altered the fatty acid composition of lipids, resulting in a 29.5–31.6% increase in palmitoleic acid production and a 22.5–35.5% increase in stearic acid production. Moreover, the transgenic Synechocystis cells also showed significant increases in levels of oleic acid (C18:1, OA, linoleic acid (C18:2, LA, and α-linolenic acid (C18:3n3, ALA. These results suggest that the fatty acid profile of algae can be significantly improved by the heterologous expression of exogenous genes. This study not only provides insight into fatty acid biosynthesis, but also lays the foundation for manipulating the fatty acid content of cyanobacteria.

  17. The C-terminal extension of ferrochelatase is critical for enzyme activity and for functioning of the tetrapyrrole pathway in Synechocystis strain PCC 6803

    Czech Academy of Sciences Publication Activity Database

    Sobotka, Roman; McLean, S.; Zuberová, M.; Hunter, C. N.; Tichý, Martin

    2008-01-01

    Roč. 190, č. 6 (2008), s. 2086-2095 ISSN 0021-9193 Grant - others:GB(GB) BBSRC Institutional research plan: CEZ:AV0Z50200510 Keywords : enzyme activity * synechocystis * ferrochelatase Subject RIV: EE - Microbiology, Virology Impact factor: 3.636, year: 2008

  18. Photosystem II Assembly in CP47 Mutant of Synechocystis sp. PCC 6803 Is Dependent on the Level of Chlorophyll Precursors Regulated by Ferrochelatase

    Czech Academy of Sciences Publication Activity Database

    Sobotka, Roman; Komenda, Josef; Bumba, Ladislav; Tichý, Martin

    2005-01-01

    Roč. 280, č. 36 (2005), s. 31595-31602 ISSN 0021-9258 R&D Projects: GA AV ČR KJB5817301 Institutional research plan: CEZ:AV0Z50510513; CEZ:AV0Z50200510 Keywords : photosystem II * synechocystis Subject RIV: EE - Microbiology, Virology Impact factor: 5.854, year: 2005

  19. Subunit composition of CP43-less photosystem II complexes of Synechocystis sp PCC 6803: implications for the assembly and repair of photosystem II

    Czech Academy of Sciences Publication Activity Database

    Boehm, M.; Yu, J.; Reisinger, V.; Bečková, Martina; Eichacker, L. A.; Schlodder, E.; Komenda, Josef; Nixon, P. J.

    2012-01-01

    Roč. 367, č. 1608 (2012), s. 3444-3454 ISSN 0962-8436 R&D Projects: GA ČR(CZ) GAP501/11/0377; GA MŠk(CZ) ED2.1.00/03.0110 Institutional support: RVO:61388971 Keywords : Synechocystis * RC47 * low-molecular-mass subunit Subject RIV: EE - Microbiology, Virology Impact factor: 6.230, year: 2012

  20. Association of Psb28 and Psb27 Proteins with PSII-PSI Supercomplexes upon Exposure of Synechocystis sp PCC 6803 to High Light

    Czech Academy of Sciences Publication Activity Database

    Bečková, Martina; Gardian, Zdenko; Yu, J.F.; Koník, Peter; Nixon, P. J.; Komenda, Josef

    2017-01-01

    Roč. 10, č. 1 (2017), s. 62-72 ISSN 1674-2052 R&D Projects: GA ČR GBP501/12/G055; GA MŠk(CZ) LO1416; GA MŠk(CZ) ED2.1.00/19.0392 Institutional support: RVO:61388971 ; RVO:60077344 Keywords : Psb28 proteins * photosystem I and II * Synechocystis Subject RIV: EE - Microbiology, Virology; CE - Biochemistry (BC-A) OBOR OECD: Microbiology; Biochemistry and molecular biology (BC-A) Impact factor: 8.827, year: 2016

  1. The transporter SynPAM71 is located in the plasma membrane and thylakoids, and mediates manganese tolerance in Synechocystis PCC6803

    DEFF Research Database (Denmark)

    Gandini, Chiara; Schmidt, Sidsel Birkelund; Husted, Søren

    2017-01-01

    Manganese (Mn) is an essential constituent of photosystem II (PSII) and therefore indispensable for oxygenic photosynthesis. Very little is known about how Mn is transported, delivered and retained in photosynthetic cells. Recently, the thylakoid-localized transporter PAM71 has been linked...... to chloroplast Mn homeostasis in Arabidopsis thaliana. Here, we characterize the function of its homolog in Synechocystis (SynPAM71). We used a loss-of-function line (ΔSynPAM71), wild-type (WT) cells exposed to Mn stress and strains expressing a tagged variant of SynPAM71 to characterize the role of SynPAM71...... in cyanobacterial Mn homeostasis. The ΔSynPAM71 strain displays an Mn-sensitive phenotype with reduced levels of chlorophyll and PSI accumulation, defects in PSII photochemistry and intracellular Mn enrichment, particularly in the thylakoid membranes. These effects are attributable to Mn toxicity, as very similar...

  2. Photosystem II Assembly Steps Take Place in the Thylakoid Membrane of the Cyanobacterium Synechocystis sp PCC6803

    Czech Academy of Sciences Publication Activity Database

    Sealo, T.T.; Zhang, L.; Knoppová, Jana; Komenda, Josef; Norling, B.

    2016-01-01

    Roč. 57, č. 1 (2016), s. 95-104 ISSN 0032-0781 R&D Projects: GA ČR GBP501/12/G055; GA MŠk LO1416 Institutional support: RVO:61388971 Keywords : Aqueous two-phase partitioning * Cyanobacteria * Photosystem II biogenesis Subject RIV: EE - Microbiology, Virology Impact factor: 4.760, year: 2016

  3. Characterization of a model cyanobacterium Synechocystis sp. PCC 6803 autotrophic growth in a flat-panel photobioreactor

    Czech Academy of Sciences Publication Activity Database

    Zavřel, T.; Sinětova, M. A.; Búzová, Diana; Literáková, Petra; Červený, Jan

    2015-01-01

    Roč. 15, č. 1 (2015), s. 122-132 ISSN 1618-0240 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073; GA MŠk(CZ) EE2.3.20.0256 Institutional support: RVO:67179843 Keywords : Carbon dioxide * Exponential phase * Growth optimization * Light * Temperature Subject RIV: EH - Ecology, Behaviour Impact factor: 2.168, year: 2015

  4. Secondary structure estimation of recombinant psbH, encoding a photosynthetic membrane protein of cyanobacterium Synechocystis sp. PCC 6803

    Czech Academy of Sciences Publication Activity Database

    Štys, Dalibor

    2005-01-01

    Roč. 43, č. 3 (2005), s. 421-424 ISSN 0300-3604 Institutional research plan: CEZ:AV0Z60870520; MSM6007665808 Keywords : protein Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.810, year: 2005

  5. CyanoP is Involved in the Early Steps of Photosystem II Assembly in the Cyanobacterium Synechocystis sp PCC 6803

    Czech Academy of Sciences Publication Activity Database

    Knoppová, Jana; Yu, J.; Koník, P.; Nixon, P.; Komenda, Josef

    2016-01-01

    Roč. 57, č. 9 (2016), s. 1921-1931 ISSN 0032-0781 R&D Projects: GA ČR GBP501/12/G055; GA MŠk(CZ) LM2015055; GA MŠk(CZ) LO1416 Institutional support: RVO:61388971 Keywords : Cyanobacteria * CyanoP * Photosynthesis Subject RIV: EE - Microbiology, Virology Impact factor: 4.760, year: 2016

  6. The ORF slr0091 of Synechocystis sp. PCC6803 encodes a high-light induced aldehyde dehydrogenase converting apocarotenals and alkanals

    KAUST Repository

    Trautmann, Danika

    2013-07-05

    Oxidative cleavage of carotenoids and peroxidation of lipids lead to apocarotenals and aliphatic aldehydes called alkanals, which react with vitally important compounds, promoting cytotoxicity. Although many enzymes have been reported to deactivate alkanals by converting them into fatty acids, little is known about the mechanisms used to detoxify apocarotenals or the enzymes acting on them. Cyanobacteria and other photosynthetic organisms must cope with both classes of aldehydes. Here we report that the Synechocystis enzyme SynAlh1, encoded by the ORF slr0091, is an aldehyde dehydrogenase that mediates oxidation of both apocarotenals and alkanals into the corresponding acids. Using a crude lysate of SynAlh1-expressing Escherichia coli cells, we show that SynAlh1 converts a wide range of apocarotenals and alkanals, with a preference for apocarotenals with defined chain lengths. As suggested by in vitro incubations and using engineered retinal-forming E. coli cells, we found that retinal is not a substrate for SynAlh1, making involvement in Synechocystis retinoid metabolism unlikely. The transcript level of SynAlh1 is induced by high light and cold treatment, indicating a role in the stress response, and the corresponding gene is a constituent of a stress-related operon. The assumptions regarding the function of SynAlh are further supported by the surprisingly high homology to human and plant aldehyde dehydrogenase that have been assigned to aldehyde detoxification. SynAlh1 is the first aldehyde dehydrogenase that has been shown to form both apocarotenoic and fatty acids. This dual function suggests that its eukaryotic homologs may also be involved in apocarotenal metabolism, a function that has not been considered so far. Aldehyde dehydrogenases play an important role in detoxification of reactive aldehydes. Here, we report on a cyanbacterial enzyme capable in converting two classes of lipid-derived aldehydes, apocaotenals and alkanals. The corresponding gene is a

  7. Dissecting the hydrogenase expression and activity of transformed escherichia coli with the bidirectional NiFe-hydrogenase from synechocystis sp. PCC 6803

    International Nuclear Information System (INIS)

    Moon, Yu Ran; Lee, Min Hee; An, Byung Chull; Chung, Byung Yeoup; Kim, Jae Sung; Kim, Jin Hong; Park, Youn Il; Kim, Cha Soon

    2009-01-01

    Synechocystis bidirectional hydrogenase genes (hoxEFUYH) and their putative promoter regions and transformed into E. coli. The hox genes were transcribed in the E. coli cells carrying the vector construct of pCCIFOS::phox::hox or pCCIFOS::pT7::hox and translated into HoxEFUYH proteins, suggesting that the putative hox promoter can be constitutively activated in E. coli. Accordingly, the total hydrogenase activity was markedly increased up to 192% or 169% in the transformed cells, while the hydrogen uptake was decreased up to about 30% of the negative control. Although the gene expression of LexA, the only one transcription regulator proven for the hox genes, was substantially decreased in the pCCIFOS::phox::hox cells after γ-irradiation of 30 Gy, the expression levels of HoxEFUYH proteins were not altered significantly. Thus, it is also suggested that other transcription regulators as well as LexA might contribute to activation of the hox promoter in E. coli

  8. Overexpression of plastid terminal oxidase inSynechocystissp. PCC 6803 alters cellular redox state.

    Science.gov (United States)

    Feilke, Kathleen; Ajlani, Ghada; Krieger-Liszkay, Anja

    2017-09-26

    Cyanobacteria are the most ancient organisms performing oxygenic photosynthesis, and they are the ancestors of plant plastids. All plastids contain the plastid terminal oxidase (PTOX), while only certain cyanobacteria contain PTOX. Many putative functions have been discussed for PTOX in higher plants including a photoprotective role during abiotic stresses like high light, salinity and extreme temperatures. Since PTOX oxidizes PQH 2 and reduces oxygen to water, it is thought to protect against photo-oxidative damage by removing excess electrons from the plastoquinone (PQ) pool. To investigate the role of PTOX we overexpressed rice PTOX fused to the maltose-binding protein (MBP-OsPTOX) in Synechocystis sp. PCC 6803, a model cyanobacterium that does not encode PTOX. The fusion was highly expressed and OsPTOX was active, as shown by chlorophyll fluorescence and P 700 absorption measurements. The presence of PTOX led to a highly oxidized state of the NAD(P)H/NAD(P) + pool, as detected by NAD(P)H fluorescence. Moreover, in the PTOX overexpressor the electron transport capacity of PSI relative to PSII was higher, indicating an alteration of the photosystem I (PSI) to photosystem II (PSII) stoichiometry. We suggest that PTOX controls the expression of responsive genes of the photosynthetic apparatus in a different way from the PQ/PQH 2 ratio.This article is part of the themed issue 'Enhancing photosynthesis in crop plants: targets for improvement'. © 2017 The Author(s).

  9. An Integrative Approach to Energy Carbon and Redox Metabolism In Cyanobacterium Synechocystis

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Ross Overbeek

    2003-06-30

    The main objectives for the first year were to produce a detailed metabolic reconstruction of synechocystis sp.pcc6803 especially in interrelated arrears of photosynthesis respiration and central carbon metabolism to support a more complete understanding and modeling of this organism. Additionally, IG, Inc. provided detailed bioinformatic analysis of selected functional systems related to carbon and energy generation and utilization, and of the corresponding pathways functional roles and individual genes to support wet lab experiments by collaborators.

  10. Identification of alcohol stress tolerance genes ofSynechocystissp. PCC 6803 using adaptive laboratory evolution.

    Science.gov (United States)

    Matsusako, Takuya; Toya, Yoshihiro; Yoshikawa, Katsunori; Shimizu, Hiroshi

    2017-01-01

    Synechocystis sp. PCC 6803 is an attractive organism for the production of alcohols, such as isobutanol and ethanol. However, because stress against the produced alcohol is a major barrier for industrial applications, it is highly desirable to engineer organisms with strong alcohol tolerance. Isobutanol-tolerant strains of Synechocystis sp. PCC 6803 were obtained by long-term passage culture experiments using medium containing 2 g/L isobutanol. These evolved strains grew on medium containing 5 g/L isobutanol on which the parental strain could not grow. Mutation analysis of the evolved strains revealed that they acquired resistance ability due to combinatorial malfunctions of slr1044 ( mcpA ) and slr0369 ( envD ), or slr0322 ( hik43 ) and envD . The tolerant strains demonstrated stress resistance against isobutanol as well as a wide variety of alcohols such as ethanol, n -butanol, and isopentanol. As a result of introducing an ethanol-producing pathway into the evolved strain, its productivity successfully increased to 142% of the control strain. Novel mutations were identified that improved the stress tolerance ability of various alcohols in Synechocystis sp. PCC 6803.

  11. The exposed N-terminal tail of the D1 subunit is required for rapid D1 degradation during Photosystem II repair in Synechocystis sp

    Czech Academy of Sciences Publication Activity Database

    Komenda, Josef; Tichý, Martin; Prášil, Ondřej; Knoppová, Jana; Kuviková, Stanislava; de Vries, R.; Nixon, P. J.

    2007-01-01

    Roč. 19, - (2007), s. 2839-2854 ISSN 1040-4651 R&D Projects: GA MŠk LN00A141; GA ČR GA203/04/0800; GA ČR GA206/06/0322 Institutional research plan: CEZ:AV0Z50200510 Keywords : photosystem II * cyanobacterium * synechocystis sp. pcc 6803 Subject RIV: EE - Microbiology, Virology Impact factor: 9.653, year: 2007

  12. The Deg proteases protect Synechocystis sp. PCC 6803 during heat and light stresses but are not essential for removal of damaged D1 protein during the Photosystem two repair cycle

    Czech Academy of Sciences Publication Activity Database

    Barker, M.; de Vries, R.; Nield, J.; Komenda, Josef; Nixon, P.

    2006-01-01

    Roč. 281, č. 41 (2006), s. 30347-30355 ISSN 0021-9258 Institutional research plan: CEZ:AV0Z50200510 Keywords : synechocystis 6803 * photosystem II * proteases Subject RIV: EE - Microbiology, Virology Impact factor: 5.808, year: 2006

  13. Inhibition of chlorophyll biosynthesis at the protochlorophyllide reduction step results in the parallel depletion of Photosystem I and Photosystem II in the cyanobacterium Synechocystis PCC 6803

    Czech Academy of Sciences Publication Activity Database

    Kopečná, Jana; Sobotka, Roman; Komenda, Josef

    2013-01-01

    Roč. 237, č. 2 (2013), s. 497-508 ISSN 0032-0935 R&D Projects: GA ČR GAP501/10/1000; GA ČR GBP501/12/G055; GA MŠk(CZ) ED2.1.00/03.0110 Institutional support: RVO:61388971 Keywords : Chlorophyll biosynthesis * Cyanobacteria * Photosystems Subject RIV: EE - Microbiology, Virology Impact factor: 3.376, year: 2013

  14. The PsbH protein is associated with the inner antenna CP47 and facilitates D1 processing and incorporation into PSII in the cyanobacterium Synechocystis PCC 6803

    Czech Academy of Sciences Publication Activity Database

    Komenda, Josef; Tichý, Martin; Eichacker, L. A.

    2005-01-01

    Roč. 46, č. 9 (2005), s. 1477-1483 ISSN 0032-0781 Institutional research plan: CEZ:AV0Z50200510 Keywords : CP47 * D1 protein * Photosysnthesis Subject RIV: EE - Microbiology, Virology Impact factor: 3.317, year: 2005

  15. Small CAB-like proteins prevent formation of singlet oxygen in the damaged photosystem II complex of the cyanobacterium Synechocystis sp PCC 6803

    Czech Academy of Sciences Publication Activity Database

    Sinha, R. K.; Komenda, Josef; Knoppová, Jana; Sedlářová, M.; Pospíšil, P.

    2012-01-01

    Roč. 35, č. 4 (2012), s. 806-818 ISSN 0140-7791 R&D Projects: GA MŠk(CZ) ED2.1.00/03.0110; GA ČR(CZ) GAP501/11/0377 Institutional research plan: CEZ:AV0Z50200510 Keywords : oxidative stress * photoinhibition * reactive oxygen species Subject RIV: EE - Microbiology, Virology Impact factor: 5.135, year: 2012

  16. A quantitative evaluation of ethylene production in the recombinant cyanobacterium Synechocystis sp PCC 6803 harboring the ethylene-forming enzyme by membrane inlet mass spectrometry

    Czech Academy of Sciences Publication Activity Database

    Zavřel, Tomáš; Knoop, H.; Steuer, R.; Jones, P. R.; Červený, Jan; Trtílek, M.

    2016-01-01

    Roč. 202, feb (2016), s. 142-151 ISSN 0960-8524 R&D Projects: GA MŠk(CZ) LO1415; GA ČR(CZ) GA15-17367S Institutional support: RVO:67179843 Keywords : biofuels * cyanobacteria * photobioreactor * MIMS * biotechnology Subject RIV: EH - Ecology, Behaviour Impact factor: 5.651, year: 2016

  17. A novel ATP-binding cassette transporter is responsible for resistance to viologen herbicides in the cyanobacterium Synechocystis sp. PCC 6803

    Czech Academy of Sciences Publication Activity Database

    Prosecká, J.; Orlov, V. N.; Fantin, Y. S.; Zinchenko, V. V.; Babykin, M. M.; Tichý, Martin

    2009-01-01

    Roč. 276, č. 15 (2009), s. 4001-4011 ISSN 1742-464X R&D Projects: GA MŠk ME 881 Institutional research plan: CEZ:AV0Z50200510 Keywords : ABC-type transporter * cyanobacteria * oxidative stress Subject RIV: EE - Microbiology, Virology Impact factor: 3.042, year: 2009

  18. Small Antisense RNA RblR Positively Regulates RuBisCo inSynechocystissp. PCC 6803.

    Science.gov (United States)

    Hu, Jinlu; Li, Tianpei; Xu, Wen; Zhan, Jiao; Chen, Hui; He, Chenliu; Wang, Qiang

    2017-01-01

    Small regulatory RNAs (sRNAs) function as transcriptional and post-transcriptional regulators of gene expression in organisms from all domains of life. Cyanobacteria are thought to have developed a complex RNA-based regulatory mechanism. In the current study, by genome-wide analysis of differentially expressed small RNAs in Synechocystis sp. PCC 6803 under high light conditions, we discovered an asRNA (RblR) that is 113nt in length and completely complementary to its target gene rbcL , which encodes the large chain of RuBisCO, the enzyme that catalyzes carbon fixation. Further analysis of the RblR(+)/(-) mutants revealed that RblR acts as a positive regulator of rbcL under various stress conditions; Suppressing RblR adversely affects carbon assimilation and thus the yield, and those phenotypes of both the wild type and the overexpressor could be downgraded to the suppressor level by carbonate depletion, indicated a regulatory role of RblR in CO 2 assimilation. In addition, a real-time expression platform in Escherichia coli was setup and which confirmed that RblR promoted the translation of the rbcL mRNA into the RbcL protein. The present study is the first report of a regulatory RNA that targets RbcL in Synechocystis sp. PCC 6803, and provides strong evidence that RblR regulates photosynthesis by positively modulating rbcL expression in Synechocystis .

  19. Awakening of a Dormant Cyanobacterium from Nitrogen Chlorosis Reveals a Genetically Determined Program

    Czech Academy of Sciences Publication Activity Database

    Klotz, A.; Georg, J.; Bučinská, Lenka; Watanabe, S.; Reimann, V.; Januszewski, W.; Sobotka, Roman; Jendrossek, D.; Hess, W. R.; Forchhammer, K.

    2016-01-01

    Roč. 26, č. 21 (2016), s. 2862-2872 ISSN 0960-9822 R&D Projects: GA MŠk(CZ) LO1416 Institutional support: RVO:61388971 Keywords : SP PCC 6803 * SYNECHOCYSTIS STRAIN PCC-6803 * STARVATION-INDUCED CHLOROSIS Subject RIV: EE - Microbiology, Virology Impact factor: 8.851, year: 2016

  20. NDH-1 Is Important for Photosystem I Function ofSynechocystissp. Strain PCC 6803 under Environmental Stress Conditions.

    Science.gov (United States)

    Zhao, Jiaohong; Gao, Fudan; Fan, Da-Yong; Chow, Wah Soon; Ma, Weimin

    2017-01-01

    Cyanobacterial NDH-1 interacts with photosystem I (PSI) to form an NDH-1-PSI supercomplex. Here, we observed that absence of NDH-1 had little, if any, effect on the functional fractions of PSI under growth conditions, but significantly reduced the functional fractions of PSI when cells of Synechocystis sp. strain PCC 6803 were moved to conditions of multiple stresses. The significant reduction in NDH-1-dependent functional fraction of PSI was initiated after PSII activity was impaired. This finding is consistent with our observation that the functional fraction of PSI under growth conditions was rapidly and significantly decreased with increasing concentrations of DCMU, which rapidly and significantly suppressed PSII activity by blocking the transfer of electrons from Q A to Q B in the PSII reaction center. Furthermore, absence of NDH-1 resulted in the PSI limitation at the functionality of PSI itself but not its donor-side and acceptor-side under conditions of multiple stresses. This was supported by the result of a significant destabilization of the PSI complex in the absence of NDH-1 but the presence of multiple stresses. Based on the above results, we propose that NDH-1 is important for PSI function of Synechocystis sp. strain PCC 6803 mainly via maintaining stabilization of PSI under conditions of environmental stresses.

  1. Accumulation of the Type IV prepilin triggers degradation of SecY and YidC and inhibits synthesis of Photosystem II proteins in the cyanobacterium Synechocystis PCC 6803

    Czech Academy of Sciences Publication Activity Database

    Linhartová, Markéta; Bučinská, Lenka; Halada, Petr; Ječmen, T.; Šetlík, Jiří; Komenda, Josef; Sobotka, Roman

    2014-01-01

    Roč. 93, č. 6 (2014), s. 1207-1223 ISSN 0950-382X R&D Projects: GA MŠk CZ.2.16/3.1.00/24023; GA ČR GA14-13967S Institutional support: RVO:61388971 Keywords : prepilin * cab-like proteins * Synechocystit Subject RIV: EE - Microbiology, Virology Impact factor: 4.419, year: 2014

  2. Role of FtsH2 in the repair of Photosystem II in mutants of the cyanobacterium Synechocystis PCC 6803 with impaired assembly or stability of the CaMn4 cluster

    Czech Academy of Sciences Publication Activity Database

    Komenda, Josef; Knoppová, Jana; Krynická, Vendula; Nixon, P. J.; Tichý, Martin

    2010-01-01

    Roč. 1797, č. 5 (2010), s. 566-575 ISSN 0005-2728 R&D Projects: GA AV ČR IAA400200801 Institutional research plan: CEZ:AV0Z50200510 Keywords : CtpA protease * D1 degradation and maturation * FtsH protease Subject RIV: EE - Microbiology, Virology Impact factor: 5.132, year: 2010

  3. Degradation of the Photosystem II D1 and D2 proteins in different strains of the cyanobacterium Synechocystis PCC 6803 varying with respect to the type and level of psbA transcript

    Czech Academy of Sciences Publication Activity Database

    Komenda, Josef; Hassan, H. A. G.; Diner, B. A.; Debus, R. J.; Barber, J.; Nixon, P. J.

    2000-01-01

    Roč. 42, - (2000), s. 635-645 ISSN 0167-4412 R&D Projects: GA ČR GA204/95/1043; GA ČR GA204/98/0418; GA AV ČR KSK2052601 Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.226, year: 2000

  4. Histidine residue 252 of the Photosystem II D1 polypeptide is involved in a light-induced cross-linking of the polypeptide with the & subunit of cytochrome b-559: study of a site-directed mutant of Synechocystis PCC 6803

    Czech Academy of Sciences Publication Activity Database

    Lupínková, Lenka; Metz, J. G.; Diner, B. A.; Vass, I.; Komenda, Josef

    2002-01-01

    Roč. 1554, - (2002), s. 192-201 ISSN 0005-2728 R&D Projects: GA ČR GA203/00/1257; GA MŠk LN00A141 Institutional research plan: CEZ:AV0Z5020903 Keywords : cyanobacterium * d1 polypeptide * photoinhibition Subject RIV: CE - Biochemistry Impact factor: 4.678, year: 2002

  5. Adaptation of a cyanobacterium to a biochemically rich environment in experimental evolution as an initial step toward a chloroplast-like state.

    Science.gov (United States)

    Hosoda, Kazufumi; Habuchi, Masumi; Suzuki, Shingo; Miyazaki, Mikako; Takikawa, Go; Sakurai, Takahiro; Kashiwagi, Akiko; Sueyoshi, Makoto; Matsumoto, Yusuke; Kiuchi, Ayako; Mori, Kotaro; Yomo, Tetsuya

    2014-01-01

    Chloroplasts originated from cyanobacteria through endosymbiosis. The original cyanobacterial endosymbiont evolved to adapt to the biochemically rich intracellular environment of the host cell while maintaining its photosynthetic function; however, no such process has been experimentally demonstrated. Here, we show the adaptation of a model cyanobacterium, Synechocystis sp. PCC 6803, to a biochemically rich environment by experimental evolution. Synechocystis sp. PCC 6803 does not grow in a biochemically rich, chemically defined medium because several amino acids are toxic to the cells at approximately 1 mM. We cultured the cyanobacteria in media with the toxic amino acids at 0.1 mM, then serially transferred the culture, gradually increasing the concentration of the toxic amino acids. The cells evolved to show approximately the same specific growth rate in media with 0 and 1 mM of the toxic amino acid in approximately 84 generations and evolved to grow faster in the media with 1 mM than in the media with 0 mM in approximately 181 generations. We did not detect a statistically significant decrease in the autotrophic growth of the evolved strain in an inorganic medium, indicating the maintenance of the photosynthetic function. Whole-genome resequencing revealed changes in the genes related to the cell membrane and the carboxysome. Moreover, we quantitatively analyzed the evolutionary changes by using simple mathematical models, which evaluated the evolution as an increase in the half-maximal inhibitory concentration (IC50) and estimated quantitative characteristics of the evolutionary process. Our results clearly demonstrate not only the potential of a model cyanobacterium to adapt to a biochemically rich environment without a significant decrease in photosynthetic function but also the properties of its evolutionary process, which sheds light of the evolution of chloroplasts at the initial stage.

  6. ORF Sequence: NC_000911 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available Synechocystis sp. PCC 6803] MYFLLVTLVILVFPLLSIALEWTTSGNSQALVDVLARWFVFWGVGVRLFLAGVVQITKPSFTAEKILGVQSQDSLILVKELGIGNLAIASVALGSIFVNAWVLGAALAGGIFYLLAGINHILQPERNAKENYAMATDLFLGLLLGGILFFAWQP

  7. Photosynthetic poly-β-hydroxybutyrate accumulation in unicellular cyanobacterium Synechocystis sp. PCC 6714.

    Science.gov (United States)

    Kamravamanesh, Donya; Pflügl, Stefan; Nischkauer, Winfried; Limbeck, Andreas; Lackner, Maximilian; Herwig, Christoph

    2017-12-01

    Poly-β-hydroxybutyrate (PHB) production from CO 2 has the potential to reduce the production cost of this biodegradable polyesters, and also to make the material more sustainable compared to utilization of sugar feedstocks. In this study the unicellular cyanobacterium, Synechocystis sp. PCC 6714 has been identified as an unexplored potential organism for production of PHB. Synechocystis sp. PCC 6714 was studied under various cultivation conditions and nutritional limitations. Combined effects of nitrogen and phosphorus deficiency led to highest PHB accumulation under photoautotrophic conditions. Multivariate experimental design and quantitative bioprocess development methodologies were used to identify the key cultivation parameters for PHB accumulation. Biomass growth and PHB accumulation were studied under controlled defined conditions in a lab-scale photobioreactor. Specific growth rates were fourfold higher in photobioreactor experiments when cultivation conditions were controlled. After 14 days of cultivation in nitrogen and phosphorus, limited media intracellular PHB levels reached up to 16.4% from CO 2 . The highest volumetric production rate of PHB was 59 ± 6 mg L -1  day -1 . Scanning electron microscopy of isolated PHB granules of Synechocystis sp. PCC 6714 cultivated under nitrogen and phosphorus limitations showed an average diameter of 0.7 µm. The results of this study might contribute towards a better understanding of photoautotrophic PHB production from cyanobacteria.

  8. Photosynhesis in dynamic light: systems biology of unconventional chlorophyll fluorescence transients in Synechocystis sp. PCC 6803

    Czech Academy of Sciences Publication Activity Database

    Nedbal, Ladislav

    2005-01-01

    Roč. 84, 1-3 (2005), s. 99-106 ISSN 0166-8595 Institutional research plan: CEZ:AV0Z60870520; MSM6007665808 Keywords : photosynthetic Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.295, year: 2005

  9. A method to decompose spectral changes in Synechocystis PCC 6803 during light-induced state transitions

    Czech Academy of Sciences Publication Activity Database

    Acuna, A.M.; Kaňa, Radek; Gwizdala, M.; Snellenburg, J.J.; van Alphen, P.; van Oort, B.; Kirilovsky, D.; van Grondelle, R.; van Stokkum, I.H.M.

    2016-01-01

    Roč. 130, 1-3 SI (2016), s. 237-249 ISSN 0166-8595 R&D Projects: GA ČR GBP501/12/G055; GA MŠk(CZ) LO1416; GA MŠk(CZ) ED2.1.00/19.0392 Institutional support: RVO:61388971 Keywords : Cyanobacteria * Spectrally resolved fluorometry * Singular value decomposition Subject RIV: EF - Botanics Impact factor: 3.864, year: 2016

  10. Genetic engineering of Synechocystis PCC6803 for the photoautotrophic production of the sweetener erythritol

    NARCIS (Netherlands)

    van der Woude, A.D.; Perez Gallego, R.; Vreugdenhil, A.; Puthan Veetil, V.; Chroumpi, T.; Hellingwerf, K.J.

    2016-01-01

    BACKGROUND: Erythritol is a polyol that is used in the food and beverage industry. Due to its non-caloric and non-cariogenic properties, the popularity of this sweetener is increasing. Large scale production of erythritol is currently based on conversion of glucose by selected fungi. In this study,

  11. Responses of Synechocystis sp. PCC 6803 to heterologous biosynthetic pathways

    DEFF Research Database (Denmark)

    Vavitsas, Konstantinos; Rue, Emil Østergaard; Stefánsdóttir, Lára Kristín

    2017-01-01

    of cellular metabolism. Regulation and response mechanisms are largely unknown, and even the metabolic pathways themselves are not fully elucidated. This poses a clear limitation in exploiting the rich biosynthetic potential of cyanobacteria. RESULTS: In this work, we focused on the production of two......BACKGROUND: There are an increasing number of studies regarding genetic manipulation of cyanobacteria to produce commercially interesting compounds. The majority of these works study the expression and optimization of a selected heterologous pathway, largely ignoring the wholeness and complexity......, and chlorophylls. This allowed us to identify metabolic crosstalk between the native and the introduced metabolic pathways. Most results and simulations highlight the metabolic robustness of cyanobacteria, suggesting that the host organism tends to keep metabolic fluxes and metabolite concentrations steady...

  12. Expression, purification and preliminary crystallization study of RpaC protein from Synechocystis sp PCC6803

    Czech Academy of Sciences Publication Activity Database

    Cséfalvay, Eva; Lapkouski, Mikalai; Komárek, Ondřej

    2009-01-01

    Roč. 3, č. 47 (2009), s. 355-362 ISSN 0300-3604 R&D Projects: GA ČR GA206/07/0917 Institutional research plan: CEZ:AV0Z60870520 Keywords : affinity chromatography * photosystem * phycobilisome – PSII supercomplex Subject RIV: CE - Biochemistry Impact factor: 1.072, year: 2009

  13. Transition from exponential to linear photoautotrophic growth changes the physiology of Synechocystis sp. PCC 6803

    NARCIS (Netherlands)

    Schuurmans, R.M.; Matthijs, J.C.P.; Hellingwerf, K.J.

    Phototrophic microorganisms like cyanobacteria show growth curves in batch culture that differ from the corresponding growth curves of chemotrophic bacteria. Instead of the usual three phases, i.e., lag-, log-, and stationary phase, phototrophs display four distinct phases. The extra growth phase is

  14. Mechanisms of High Temperature Resistance of Synechocystis sp. PCC 6803: An Impact of Histidine Kinase 34

    Czech Academy of Sciences Publication Activity Database

    Červený, Jan; Sinětova, M. A.; Zavřel, Tomáš; Los, D. A.

    2015-01-01

    Roč. 5, č. 1 (2015), s. 676-699 ISSN 2075-1729 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073; GA MŠk(CZ) EE2.3.20.0256; GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 Keywords : photosynthesis * pigments * ultrastructure * heat stress proteins * photobioreactor * cyanobacteria Subject RIV: EH - Ecology, Behaviour

  15. Dispensability of a sulfolipid for photoautotrophic cell growth and photosynthesis in a marine cyanobacterium, Synechococcus sp. PCC 7002.

    Science.gov (United States)

    Sato, Norihiro; Kamimura, Ryohei; Tsuzuki, Mikio

    2016-09-02

    Sulfoquinovosyl diacylglycerol, which mainly comprises thylakoid membranes in oxygenic photosynthetic organisms, plays species-dependent roles in freshwater microbes. In this study, a sulfoquinovosyl-diacylglycerol deficient mutant was generated in a cyanobacterium, Synechococcus sp. PCC 7002, for the first time among marine microbes to gain more insight into its physiological significance. The mutation had little deleterious impact on photoautotrophic cell growth, and functional and structural properties of the photosystem II complex. These findings were similar to previous observations for a freshwater cyanobacterium, Synechococcus elongatus PCC 7942, but were distinct from those for another freshwater cyanobacterium, Synechocystis sp. PCC 6803, and a green alga, Chlamydomonas reinhardtii, both of which require sulfoquinovosyl diacylglycerol for cell growth and/or photosystem II. Therefore, the functionality of PSII to dispense with sulfoquinovosyl diacylglycerol in Synechococcus sp. PCC 7002, similar to that in Synechococcus elongatus PCC 7942, seemed to have been excluded from the evolution of the PSII complex from cyanobacteria to green algal chloroplasts. Meanwhile, sulfoquinovosyl diacylglycerol was found to contribute to photoheterotrophic growth of Synechococcus sp. PCC 7002, which revealed a novel species-dependent strategy for utilizing SQDG in physiological processes. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Radiation characteristics and effective optical properties of dumbbell-shaped cyanobacterium Synechocystis sp.

    Science.gov (United States)

    Heng, Ri-Liang; Pilon, Laurent

    2016-05-01

    This study presents experimental measurements of the radiation characteristics of unicellular freshwater cyanobacterium Synechocystis sp. during their exponential growth in F medium. Their scattering phase function at 633 nm average spectral absorption and scattering cross-sections between 400 and 750 nm were measured. In addition, an inverse method was used for retrieving the spectral effective complex index of refraction of overlapping or touching bispheres and quadspheres from their absorption and scattering cross-sections. The inverse method combines a genetic algorithm and a forward model based on Lorenz-Mie theory, treating bispheres and quadspheres as projected area and volume-equivalent coated spheres. The inverse method was successfully validated with numerically predicted average absorption and scattering cross-sections of suspensions consisting of bispheres and quadspheres, with realistic size distributions, using the T-matrix method. It was able to retrieve the monomers' complex index of refraction with size parameter up to 11, relative refraction index less than 1.3, and absorption index less than 0.1. Then, the inverse method was applied to retrieve the effective spectral complex index of refraction of Synechocystis sp. approximated as randomly oriented aggregates consisting of two overlapping homogeneous spheres. Both the measured absorption cross-section and the retrieved absorption index featured peaks at 435 and 676 nm corresponding to chlorophyll a, a peak at 625 nm corresponding to phycocyanin, and a shoulder around 485 nm corresponding to carotenoids. These results can be used to optimize and control light transfer in photobioreactors. The inverse method and the equivalent coated sphere model could be applied to other optically soft particles of similar morphologies.

  17. Anilofos tolerance and its mineralization by the cyanobacterium Synechocystis sp. strain PUPCCC 64.

    Directory of Open Access Journals (Sweden)

    D P Singh

    Full Text Available This study deals with anilofos tolerance and its mineralization by the common rice field cyanobacterium Synechocystis sp. strain PUPCCC 64. The organism tolerated anilofos up to 25 mg L(-1. The herbicide caused inhibitory effects on photosynthetic pigments of the test organism in a dose-dependent manner. The organism exhibited 60, 89, 96, 85 and 79% decrease in chlorophyll a, carotenoids, phycocyanin, allophycocyanin and phycoerythrin, respectively, in 20 mg L(-1 anilofos on day six. Activities of superoxide dismutase, catalase and peroxidase increased by 1.04 to 1.80 times over control cultures in presence of 20 mg L(-1 anilofos. Glutathione content decreased by 26% while proline content was unaffected by 20 mg L(-1 anilofos. The test organism showed intracellular uptake and metabolized the herbicide. Uptake of herbicide by test organism was fast during initial six hours followed by slow uptake until 120 hours. The organism exhibited maximum anilofos removal at 100 mg protein L(-1, pH 8.0 and 30°C. Its growth in phosphate deficient basal medium in the presence of anilofos (2.5 mg L(-1 indicated that herbicide was used by the strain PUPCCC 64 as a source of phosphate.

  18. Genetic analysis of amino acid transport in the facultatively heterotrophic cyanobacterium Synechocystis sp. Strain 6803

    International Nuclear Information System (INIS)

    Labarre, J.; Thuriaux, P.; Chauvat, F.

    1987-01-01

    The existence of active transport systems (permeases) operating on amino acids in the photoautotrophic cyanobacterium Synechocystis sp. strain 6803 was demonstrated by following the initial rates of uptake with 14 C-labeled amino acids, measuring the intracellular pools of amino acids, and isolating mutants resistant to toxic amino acids. One class of mutants (Pfa1) corresponds to a regulatory defect in the biosynthesis of the aromatic amino acids, but two other classes (Can1 and Aza1) are defective in amino acid transport. The Can1 mutants are defective in the active transport of three basic amino acids (arginine, histidine, and lysine) and in one of two transport systems operating on glutamine. The Aza1 mutants are not affected in the transport of the basic amino acids but have lost the capacity to transport all other amino acids except glutamate. The latter amino acid is probably transported by a third permease which could be identical to the Can1-independent transport operating on glutamine. Thus, genetic evidence suggests that strain 6803 has only a small number of amino acid transport systems with fairly broad specificity and that, with the exception of glutamine, each amino acid is accumulated by only one major transport system. Compared with heterotrophic bacteria such as Escherichia coli, these permeases are rather inefficient in terms of affinity (apparent K/sub m/ ranging from 6 to 60 μM) and of V/sub max/

  19. Chemoheterotrophic growth of the Cyanobacterium Anabaena sp. strain PCC 7120 dependent on a functional cytochrome c oxidase.

    Science.gov (United States)

    Stebegg, Ronald; Wurzinger, Bernhard; Mikulic, Markus; Schmetterer, Georg

    2012-09-01

    Anabaena sp. strain PCC 7120 is a filamentous cyanobacterium commonly used as a model organism for studying cyanobacterial cell differentiation and nitrogen fixation. For many decades, this cyanobacterium was considered an obligate photo-lithoautotroph. We now discovered that this strain is also capable of mixotrophic, photo-organoheterotrophic, and chemo-organoheterotrophic growth if high concentrations of fructose (at least 50 mM and up to 200 mM) are supplied. Glucose, a substrate used by some facultatively organoheterotrophic cyanobacteria, is not effective in Anabaena sp. PCC 7120. The gtr gene from Synechocystis sp. PCC 6803 encoding a glucose carrier was introduced into Anabaena sp. PCC 7120. Surprisingly, the new strain containing the gtr gene did not grow on glucose but was very sensitive to glucose, with a 5 mM concentration being lethal, whereas the wild-type strain tolerated 200 mM glucose. The Anabaena sp. PCC 7120 strain containing gtr can grow mixotrophically and photo-organoheterotrophically, but not chemo-organoheterotrophically with fructose. Anabaena sp. PCC 7120 contains five respiratory chains ending in five different respiratory terminal oxidases. One of these enzymes is a mitochondrial-type cytochrome c oxidase. As in almost all cyanobacteria, this enzyme is encoded by three adjacent genes called coxBAC1. When this locus was disrupted, the cells lost the capability for chemo-organoheterotrophic growth.

  20. Diel regulation of photosynthetic activity in the oceanic unicellular diazotrophic cyanobacterium Crocosphaera watsonii WH8501

    Czech Academy of Sciences Publication Activity Database

    Masuda, Takako; Bernát, Gábor; Bečková, Martina; Kotabová, Eva; Lawrenz, Evelyn; Lukeš, Martin; Komenda, Josef; Prášil, Ondřej

    2018-01-01

    Roč. 20, č. 2 (2018), s. 546-560 ISSN 1462-2912 R&D Projects: GA MŠk(CZ) LO1416; GA MŠk(CZ) ED2.1.00/19.0392; GA ČR GA16-15467S Institutional support: RVO:61388971 Keywords : NORTH PACIFIC-OCEAN * SYNECHOCYSTIS SP PCC-6803; * PHOTOSYSTEM-II Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 5.395, year: 2016

  1. The distribution of phosphorus and its transformations during batch growth of Synechocystis.

    Science.gov (United States)

    Zhou, Yun; Nguyen, Binh T; Zhou, Chen; Straka, Levi; Lai, YenJung Sean; Xia, Siqing; Rittmann, Bruce E

    2017-10-01

    Phosphorus (P) is an essential nutrient that affects the growth and metabolism of microalgal biomass. Despite the obvious importance of P, the dynamics of how it is taken up and distributed in microalgae are largely undefined. In this study, we tracked the fate of P during batch growth of the cyanobacterium Synechocystis sp. PCC 6803. We determined the distribution of P in intracellular polymeric substances (IPS), extracellular polymeric substances (EPS), and soluble microbial products (SMP) for three initial ortho-phosphate concentrations. Results show that the initial P concentration had no impact on the production of biomass, SMP, and EPS. While the initial P concentration affected the rate and the timing of how P was transformed among internal and external forms of inorganic P (IP) and organic P (OP), the trends were the same no matter the starting P concentration. Initially, IP in the bulk solution was rapidly and simultaneously adsorbed by EPS (IP EPS ) and taken up as internal IP (IP int ). As the bulk-solution's IP was depleted, desorption of IP EPS became the predominant source for IP that was taken up by the growing cells and converted into OP int . At the end of the 9-d batch experiments, almost all P was OP, and most of the OP was intracellular. Based on all of the results, we propose a set of transformation pathways for P during the growth of Synechocystis. Key is that EPS and intracellular P pool play important and distinct roles in the uptake and storage of P. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Global Proteomics Reveal An Atypical Strategy for Carbon/Nitrogen Assimilation by a Cyanobacterium Under Diverse Environmental Perturbations

    Energy Technology Data Exchange (ETDEWEB)

    Wegener, Kimberly M.; Singh, Abhay K.; Jacobs, Jon M.; Elvitigala, Thanura R.; Welsh, Eric A.; Keren, Nir S.; Gritsenko, Marina A.; Ghosh, Bijoy K.; Camp, David G.; Smith, Richard D.; Pakrasi, Himadri B.

    2010-12-01

    Cyanobacteria, the only prokaryotes capable of oxygenic photosynthesis, are present in diverse ecological niches and play crucial roles in global carbon and nitrogen cycles. To proliferate in nature, cyanobacteria utilize a host of stress responses to accommodate periodic changes in environmental conditions. A detailed knowledge of the composition of, as well as the dynamic changes in, the proteome is necessary to gain fundamental insights into such stress responses. Toward this goal, we have performed a largescale proteomic analysis of the widely studied model cyanobacterium Synechocystis sp. PCC 6803 under 33 different environmental conditions. The resulting high-quality dataset consists of 22,318 unique peptides corresponding to 1,955 proteins, a coverage of 53% of the predicted proteome. Quantitative determination of protein abundances has led to the identification of 1,198 differentially regulated proteins. Notably, our analysis revealed that a common stress response under various environmental perturbations, irrespective of amplitude and duration, is the activation of atypical pathways for the acquisition of carbon and nitrogen from urea and arginine. In particular, arginine is catabolized via putrescine to produce succinate and glutamate, sources of carbon and nitrogen, respectively. This study provides the most comprehensive functional and quantitative analysis of the Synechocystis proteome to date, and shows that a significant stress response of cyanobacteria involves an uncommon mode of acquisition of carbon and nitrogen. Oxygenic phototrophic prokaryotes, the progenitors of the chloroplast, are crucial to global oxygen production and worldwide carbon and nitrogen cycles. These microalgae are robust organisms capable carbon neutral biofuel production. Synechocystis sp. PCC 6803 has historically been a model cyanobacterium for photosynthetic research and is emerging as a promising biofuel platform. Cellular responses are severely modified by environmental

  3. Lipid and carotenoid cooperation-driven adaptation to light and temperature stress in Synechocystis sp. PCC6803

    Czech Academy of Sciences Publication Activity Database

    Zakar, T.; Herman, E.; Vajravel, S.; Kovács, L.; Knoppová, Jana; Komenda, Josef; Domonkos, I.; Kis, M.; Gombos, Z.; Laczko-Dobos, H.

    2017-01-01

    Roč. 1858, č. 5 (2017), s. 337-350 ISSN 0005-2728 R&D Projects: GA MŠk(CZ) LM2015055; GA MŠk(CZ) LO1416 Institutional support: RVO:61388971 Keywords : Lipid-carotenoid-protein interactions * Lipid remodeling * Xanthophylls Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 4.932, year: 2016

  4. Chirality Matters: Synthesis and Consumption of the d-Enantiomer of Lactic Acid by Synechocystis sp. Strain PCC6803

    NARCIS (Netherlands)

    Angermayr, S.A.; van der Woude, A.D.; Correddu, D.; Kern, R.; Hagemann, M.; Hellingwerf, K.J.

    2015-01-01

    Both enantiomers of lactic acid, l-lactic acid and d-lactic acid, can be produced in a sustainable way by a photosynthetic microbial cell factory and thus from CO2, sunlight, and water. Several properties of polylactic acid (a polyester of polymerized lactic acid) depend on the controlled blend of

  5. Involvement of carotenoids in the synthesis and assembly of protein subunits of photosynthetic reaction centers of Synechocystis sp. PCC 6803

    Czech Academy of Sciences Publication Activity Database

    Sozer, O.; Komenda, Josef; Ughy, B.; Domonkos, I.; Laczkó-Dobos, H.; Malec, P.; Gombos, Z.; Kis, M.

    2010-01-01

    Roč. 51, č. 5 (2010), s. 823-835 ISSN 0032-0781 R&D Projects: GA AV ČR IAA400200801 Institutional research plan: CEZ:AV0Z50200510 Keywords : Carotenoidless mutant * crtB * Membrane protein synthesis Subject RIV: EE - Microbiology, Virology Impact factor: 4.257, year: 2010

  6. Diversity in photosynthetic electron transport under [CO2]-limitation: the cyanobacterium Synechococcus sp. PCC 7002 and green alga Chlamydomonas reinhardtii drive an O2-dependent alternative electron flow and non-photochemical quenching of chlorophyll fluorescence during CO2-limited photosynthesis.

    Science.gov (United States)

    Shimakawa, Ginga; Akimoto, Seiji; Ueno, Yoshifumi; Wada, Ayumi; Shaku, Keiichiro; Takahashi, Yuichiro; Miyake, Chikahiro

    2016-12-01

    Some cyanobacteria, but not all, experience an induction of alternative electron flow (AEF) during CO 2 -limited photosynthesis. For example, Synechocystis sp. PCC 6803 (S. 6803) exhibits AEF, but Synechococcus elongatus sp. PCC 7942 does not. This difference is due to the presence of flavodiiron 2 and 4 proteins (FLV2/4) in S. 6803, which catalyze electron donation to O 2 . In this study, we observed a low-[CO 2 ] induced AEF in the marine cyanobacterium Synechococcus sp. PCC 7002 that lacks FLV2/4. The AEF shows high affinity for O 2 , compared with AEF mediated by FLV2/4 in S. 6803, and can proceed under extreme low [O 2 ] (about a few µM O 2 ). Further, the transition from CO 2 -saturated to CO 2 -limited photosynthesis leads a preferential excitation of PSI to PSII and increased non-photochemical quenching of chlorophyll fluorescence. We found that the model green alga Chlamydomonas reinhardtii also has an O 2 -dependent AEF showing the same affinity for O 2 as that in S. 7002. These data represent the diverse molecular mechanisms to drive AEF in cyanobacteria and green algae. In this paper, we further discuss the diversity, the evolution, and the physiological function of strategy to CO 2 -limitation in cyanobacterial and green algal photosynthesis.

  7. Protein (Cyanobacteria): 450480 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available CCP_1839 Synechocystis sp. PCC 6803 substr. PCC-P MNIQEIQTIANQLTLTLDSPQSVKLQVKQINLAQKQLRAIKKEINAHIRQINQDASQAYSDSIVSVGLDIFGKNKWAGRVRAETRRMIERNKKDARQPYMELKDYIDQLILKGDKLKLSAEQYLLSRE ...

  8. Protein (Cyanobacteria): 450478 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available TI_1840 Synechocystis sp. PCC 6803 substr. GT-I MNIQEIQTIANQLTLTLDSPQSVKLQVKQINLAQKQLRAIKKEINAHIRQINQDASQAYSDSIVSVGLDIFGKNKWAGRVRAETRRMIERNKKDARQPYMELKDYIDQLILKGDKLKLSAEQYLLSRE ...

  9. Inquisition of Microcystis aeruginosa and Synechocystis nanowires: characterization and modelling.

    Science.gov (United States)

    Sure, Sandeep; Torriero, Angel A J; Gaur, Aditya; Li, Lu Hua; Chen, Ying; Tripathi, Chandrakant; Adholeya, Alok; Ackland, M Leigh; Kochar, Mandira

    2015-11-01

    Identification of extracellular conductive pilus-like structures (PLS) i.e. microbial nanowires has spurred great interest among scientists due to their potential applications in the fields of biogeochemistry, bioelectronics, bioremediation etc. Using conductive atomic force microscopy, we identified microbial nanowires in Microcystis aeruginosa PCC 7806 which is an aerobic, photosynthetic microorganism. We also confirmed the earlier finding that Synechocystis sp. PCC 6803 produces microbial nanowires. In contrast to the use of highly instrumented continuous flow reactors for Synechocystis reported earlier, we identified simple and optimum culture conditions which allow increased production of nanowires in both test cyanobacteria. Production of these nanowires in Synechocystis and Microcystis were found to be sensitive to the availability of carbon source and light intensity. These structures seem to be proteinaceous in nature and their diameter was found to be 4.5-7 and 8.5-11 nm in Synechocystis and M. aeruginosa, respectively. Characterization of Synechocystis nanowires by transmission electron microscopy and biochemical techniques confirmed that they are type IV pili (TFP) while nanowires in M. aeruginosa were found to be similar to an unnamed protein (GenBank : CAO90693.1). Modelling studies of the Synechocystis TFP subunit i.e. PilA1 indicated that strategically placed aromatic amino acids may be involved in electron transfer through these nanowires. This study identifies PLS from Microcystis which can act as nanowires and supports the earlier hypothesis that microbial nanowires are widespread in nature and play diverse roles.

  10. Structural insights into enzymatic activity and substrate specificity determination by a single amino acid in nitrilase from Syechocystis sp. PCC6803.

    Science.gov (United States)

    Zhang, Lujia; Yin, Bo; Wang, Chao; Jiang, Shuiqin; Wang, Hualei; Yuan, Y Adam; Wei, Dongzhi

    2014-11-01

    Nitrilases are enzymes widely expressed in prokaryotes and eukaryotes that utilize a Cys–Glu–Lys catalytic triad to hydrolyze non-peptide carbon–nitrogen bonds. Nitrilase from Syechocystis sp. Strain PCC6803 (Nit6803) shows hydrolysis activity towards a broad substrate spectrum, ranging from mononitriles to dinitriles and from aromatic nitriles to aliphatic nitriles. Yet, the structural principle of the substrate specificity of this nitrilase is still unknown. We report the crystal structure of Nit6803 at 3.1 Å resolution and propose a structural mechanism of substrate selection. Our mutagenesis data exhibited that the aromaticity of the amino acid at position 146 of Nit6803 is absolutely required for its nitrilase activity towards any substrates tested. Moreover, molecular docking and dynamic simulation analysis indicated that the distance between the sulfhydryl group of the catalytic cysteine residue and the cyano carbon of the substrate plays a crucial role in determining the nitrilase catalytic activity of Nit6803 and its mutants towards different nitrile substrates.

  11. Native isolation of the CesB protein from Synechocystis sp.PCC 6803 involved in cytochrome f maturation in cyanobacteria and plastids

    Czech Academy of Sciences Publication Activity Database

    Tichý, Martin

    2003-01-01

    Roč. 41, č. 4 (2003), s. 583-588 ISSN 0300-3604 R&D Projects: GA AV ČR IAB5020002; GA MŠk LN00A141 Institutional research plan: CEZ:AV0Z5020903 Keywords : doubling time * mutants * photrosystem2 Subject RIV: EE - Microbiology, Virology Impact factor: 0.661, year: 2003

  12. Absence of the psbH gene product destabilizes photosystem II complex and bicarbonate binding on its acceptor side in Synechocystis PCC 6803

    Czech Academy of Sciences Publication Activity Database

    Komenda, Josef; Lupínková, Lenka; Kopecký, Jiří

    2002-01-01

    Roč. 269, - (2002), s. 610-619 ISSN 0014-2956 R&D Projects: GA MŠk LN00A141 Institutional research plan: CEZ:AV0Z5020903 Keywords : cyanobacteria * d1 protein * photosystem Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.999, year: 2002

  13. Investigating the early stages of Photosystem II assembly in Synechocystis sp. PCC 6803: isolation of CP47 and CP43 complexe

    Czech Academy of Sciences Publication Activity Database

    Boehm, M.; Romero, E.; Reisinger, V.; Yu, J.; Komenda, Josef; Eichacker, L. A.; Dekker, J. P.; Nixon, P. J.

    2011-01-01

    Roč. 286, č. 17 (2011), 14812-14819 ISSN 0021-9258 R&D Projects: GA AV ČR IAA400200801 Institutional research plan: CEZ:AV0Z50200510 Keywords : ENERGY CHLOROPHYLL STATES * ANTENNA PROTEIN COMPLEX * OXYGEN-EVOLVING CENTER Subject RIV: EE - Microbiology, Virology Impact factor: 4.773, year: 2011

  14. Inactivation of the conserved open reading frame ycf34 of Synechocystis sp PCC 6803 interferes with the photosynthetic electron transport chain

    Czech Academy of Sciences Publication Activity Database

    Wallner, T.; Hagiwara, Y.; Bernát, G.; Sobotka, Roman; Reijerse, E. J.; Frankenberg-Dinkel, N.; Wilde, A.

    2012-01-01

    Roč. 1817, č. 11 (2012), s. 2016-2026 ISSN 0005-2728 R&D Projects: GA MŠk(CZ) ED2.1.00/03.0110 Institutional support: RVO:61388971 Keywords : Hypothetical chloroplast open reading frame * Iron-sulphur protein * Phycobilisome Subject RIV: EE - Microbiology, Virology Impact factor: 4.624, year: 2012

  15. Supercomplexes of IsiA and photosystem I in a mutant lacking subunit PsaL

    NARCIS (Netherlands)

    Kouril, R.; Yeremenko, N.; D'Haene, S.; Oostergetel, G.T.; Matthijs, H.C.P.; Dekker, J.P.; Boekema, E.J.

    2005-01-01

    The cyanobacterium Synechocystis PCC 6803 grown under short-term iron-deficient conditions assembles a supercomplex consisting of a trimeric Photosystem I (PSI) complex encircled by a ring of 18 IsiA complexes. Furthermore, it has been shown that single or double rings of IsiA with up to 35 copies

  16. Synechocystis ferredoxin-NADP(+) oxidoreductase is capable of functioning as ferric reductase and of driving the Fenton reaction in the absence or presence of free flavin.

    Science.gov (United States)

    Sato, Junichi; Takeda, Kouji; Nishiyama, Rika; Watanabe, Toshihiro; Abo, Mitsuru; Yoshimura, Etsuro; Nakagawa, Junichi; Abe, Akira; Kawasaki, Shinji; Niimura, Youichi

    2011-04-01

    We purified free flavin-independent NADPH oxidoreductase from Synechocystis sp. PCC6803 based on NADPH oxidation activity elicited during reduction of t-butyl hydroperoxide in the presence of Fe(III)-EDTA. The N-terminal sequencing of the purified enzyme revealed it to be ferredoxin-NADP(+) oxidoreductase (FNR( S )). The purified enzyme reacted with cytochrome c, ferricyanide and 2,6-dichloroindophenol (DCIP). The substrate specificity of the enzyme was similar to the known FNR. DNA degradation occurring in the presence of NADPH, Fe(III)-EDTA and hydrogen peroxide was potently enhanced by the purified enzyme, indicating that Synechocystis FNR( S ) may drive the Fenton reaction. The Fenton reaction by Synechocystis FNR( S ) in the presence of natural chelate iron compounds tended to be considerably lower than that in the presence of synthetic chelate iron compounds. The Synechocystis FNR( S ) is considered to reduce ferric iron to ferrous iron when it evokes the Fenton reaction. Although Synechocystis FNR( S ) was able to reduce iron compounds in the absence of free flavin, the ferric reduction by the enzyme was enhanced by the addition of free flavin. The enhancement was detected not only in the presence of natural chelate iron compounds but also synthetic chelate iron compounds.

  17. Unraveling photosystems. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-09-01

    This report highlights four main points. (1) A residue substitution in phosphoribulokinase of Synechocystis PCC 6803 renders the mutant light-sensitive. The authors isolated a light-sensitive mutant (BRLS) of the photosynthetic cyanobacterium Synechocystis 6803 that does not survive exposure to bright light; 70% of BRLS cells die upon exposure to light of > 3000 lux for 2 hr. (2) Excitation energy transfer from phycocyanin to chlorophyll in an apcA-defective mutant of Synechocystis sp. PCC 6803. A greenish mutant of the normally bule-green cyanobacterium Synechocystis sp. PC 6803, designated UV6p, was isolated and characterized. UV6p possesses functional photosystems I and II but lacks normal light harvesting phycobilisomes because allophycocyanin is absent and core-specific linker proteins are almost entirely absent. (3) Deletion of the psbG1 gene of the cyanobacterium Synechocystis sp. PCC 6803 leads to the activation of the cryptic psbG2 gene. The genes psbG1 and psbG2 in cyanobacterium Synechocystis sp. PCC 6803 are homologous. The psbG1 gene is located on the chromosome and is part of the ndhC-psbG1-ORF157 operon, while psbG2 is located on a plasmid and is not flanked by equivalent ndhC or ORF157 genes. (4) Deletion of the structural gene for the NADH-dehydrogenase subunit 4 of Synechocystis 6803 alters respiratory properties. Chloroplasts and cyanobacteria contain genes encoding polypeptides homologous to some subunits of the mitochondrial respiratory NADH-ubiquinol oxidoreductase complex (NADH dehydrogenase). Nothing is known of the role of the NADH dehydrogenase complex in photosynthesis, respiration, or other functions in chloroplasts, and little is known about their specific roles in the perhaps 42 subunits of this complex in the mitochondrion.

  18. Carotenóides da cianobactéria Synechocystis pevalekii produzida em condições normais e sob limitação de nutrientes Carotenoids of the cyanobacterium Synechocystis pevalekii produced under normal conditions and under nutrient limitation

    Directory of Open Access Journals (Sweden)

    Marcos Coelho Müller

    2003-12-01

    -²-carotene, echinenone, ²-cryptoxanthin, 3-hydroxy-4'-ketocarotenoid, zeaxanthin and 3,3-dihydroxy-4'-ketocarotenoid were identified in the cyanobacterium Synechocystis pevalekii. The cianobacterium was green because of the presence of chlorophylls. When cultivated under stress (80% reduction of nutrient content of the original Conway medium the chlorophylls disappeared and the cyanobacterium assumed an orange color. ²-Carotene decreased from 307 to 248 µg/g and ²-cryptoxanthin from 94 to 13 µg/g. On the other hand, zeaxanthin increased from 29 to 220 µg/g. Thus, S. pevalekii appears to have commercial potential as source of zeaxanthin, which is implicated in the reduction of the risk of macular degeneration and cataract, together with lutein. The results also showed that conditions for the production of the cyanobacterium can be established so that the biosynthesis of carotenoids important to human health, but difficult to obtain, can be favored. There are already several commercial sources of ²-carotene, but sources of zeaxanthin are rare.

  19. Chlorophyll b can serve as the major pigment in functional photosystem II complexes of cyanobacteria

    OpenAIRE

    Xu, Hong; Vavilin, Dmitrii; Vermaas, Wim

    2001-01-01

    An Arabidopsis thaliana chlorophyll(ide) a oxygenase gene (cao), which is responsible for chlorophyll b synthesis from chlorophyll a, was introduced and expressed in a photosystem I-less strain of the cyanobacterium Synechocystis sp. PCC 6803. In this strain, most chlorophyll is associated with the photosystem II complex. In line with observations by Satoh et al. [Satoh, S., Ikeuchi, M., Mimuro, M. & Tanaka, A. (2001) J. Biol. Chem. 276, 4293–4297], chlorophyll b was made but accounted for le...

  20. Effects of phosphate limitation on soluble microbial products and microbial community structure in semi-continuous Synechocystis-based photobioreactors.

    Science.gov (United States)

    Zevin, Alexander S; Nam, Taekgul; Rittmann, Bruce; Krajmalnik-Brown, Rosa

    2015-09-01

    All bacteria release organic compounds called soluble microbial products (SMP) as a part of their normal metabolism. In photobioreactor (PBR) settings, SMP produced by cyanobacteria represent a major pool of carbon and electrons available to heterotrophic bacteria. Thus, SMP in PBRs are a major driver for the growth of heterotrophic bacteria, and understanding the distribution of SMP in PBRs is an important step toward proper management of PBR microbial communities. Here, we analyzed the SMP and microbial communities in two Synechocystis sp. PCC6803-based PBRs. The first PBR (PBRP0) became phosphate limited after several days of operation, while the second PBR (PBRP+) did not have phosphate limitation. Heterotrophic bacteria were detected in both PBRs, but PBRP0 had a much higher proportion of heterotrophic bacteria than PBRP+. Furthermore, PBRP+ had greater biomass production and lower SMP production per unit biomass than PBRP0. Carbohydrates that were most likely derived from hydrolysis of extracellular polymeric substances (EPS) dominated the SMP in PBRP0, while products resulting from cell lysis or decay dominated the SMP in PBRP+. Together, our data support that maintaining phosphate availability in Synechocystis-based PBRs is important for managing SMP and, thus, the heterotrophic community. © 2015 Wiley Periodicals, Inc.

  1. Cleavage after residue Ala352 in the C-terminal extension is an early step in the maturation of the D1 subunit of Photosystem II in Synechocystis PCC 6803

    Czech Academy of Sciences Publication Activity Database

    Komenda, Josef; Kuviková, Stanislava; Granvogl, B.; Eichacker, L. A.; Diner, B. A.; Nixon, P. J.

    2007-01-01

    Roč. 1767, - (2007), s. 829-837 ISSN 0005-2728 Institutional research plan: CEZ:AV0Z50200510 Keywords : ctpa protease * d1 maturation * photosystem II Subject RIV: EE - Microbiology, Virology Impact factor: 3.835, year: 2007

  2. Functional assignments for the carboxyl-terminal domains of the ferrochelatase from Synechocystis PCC 6803: The CAB domain plays a regulatory role, and region II is essential for catalysis

    Czech Academy of Sciences Publication Activity Database

    Sobotka, Roman; Tichý, Martin; Wilde, A.; Hunter, C. N.

    2011-01-01

    Roč. 155, č. 4 (2011), 1735-1747 ISSN 0032-0889 R&D Projects: GA ČR GAP501/10/1000 Institutional research plan: CEZ:AV0Z50200510 Keywords : TRANSFER-RNA REDUCTASE * DELTA-AMINOLEVULINIC-ACID * PHOTOSYSTEM-II Subject RIV: EE - Microbiology, Virology Impact factor: 6.535, year: 2011

  3. Global Proteomic Analysis Reveals an Exclusive Role of Thylakoid Membranes in Bioenergetics of a Model Cyanobacterium

    Energy Technology Data Exchange (ETDEWEB)

    Liberton, Michelle; Saha, Rajib; Jacobs, Jon M.; Nguyen, Amelia Y.; Gritsenko, Marina A.; Smith, Richard D.; Koppenaal, David W.; Pakrasi, Himadri B.

    2016-04-07

    Cyanobacteria are photosynthetic microbes with highly differentiated membrane systems. These organisms contain an outer membrane, plasma membrane, and an internal system of thylakoid membranes where the photosynthetic and respiratory machinery are found. This existence of compartmentalization and differentiation of membrane systems poses a number of challenges for cyanobacterial cells in terms of organization and distribution of proteins to the correct membrane system. Proteomics studies have long sought to identify the components of the different membrane systems, and to date about 450 different proteins have been attributed to either the plasma membrane or thylakoid membrane. Given the complexity of these membranes, many more proteins remain to be identified in these membrane systems, and a comprehensive catalog of plasma membrane and thylakoid membrane proteins is needed. Here we describe the identification of 635 proteins in Synechocystis sp. PCC 6803 by quantitative iTRAQ isobaric labeling; of these, 459 proteins were localized to the plasma membrane and 176 were localized to the thylakoid membrane. Surprisingly, we found over 2.5 times the number of unique proteins identified in the plasma membrane compared to the thylakoid membrane. This suggests that the protein composition of the thylakoid membrane is more homogeneous than the plasma membrane, consistent with the role of the plasma membrane in diverse cellular processes including protein trafficking and nutrient import, compared to a more specialized role for the thylakoid membrane in cellular energetics. Overall, the protein composition of the Synechocystis 6803 plasma membrane and thylakoid membrane is quite similar to the E.coli plasma membrane and Arabidopsis thylakoid membrane, respectively. Synechocystis 6803 can therefore be described as a gram-negative bacterium that has an additional internal membrane system that fulfils the energetic requirements of the cell.

  4. Global Proteomic Analysis Reveals an Exclusive Role of Thylakoid Membranes in Bioenergetics of a Model Cyanobacterium

    Energy Technology Data Exchange (ETDEWEB)

    Liberton, Michelle; Saha, Rajib; Jacobs, Jon M.; Nguyen, Amelia Y.; Gritsenko, Marina A.; Smith, Richard D.; Koppenaal, David W.; Pakrasi, Himadri B.

    2016-04-07

    Cyanobacteria are photosynthetic microbes with highlydifferentiated membrane systems. These organisms contain an outer membrane, plasma membrane, and an internal system of thylakoid membranes where the photosynthetic and respiratory machinery are found. This existence of compartmentalization and differentiation of membrane systems poses a number of challenges for cyanobacterial cells in terms of organization and distribution of proteins to the correct membrane system. Proteomics studies have long sought to identify the components of the different membrane systems in cyanobacteria, and to date about 450 different proteins have been attributed to either the plasma membrane or thylakoid membrane. Given the complexity of these membranes, many more proteins remain to be identified, and a comprehensive catalogue of plasma membrane and thylakoid membrane proteins is needed. Here we describe the identification of 635 differentially localized proteins in Synechocystis sp. PCC 6803 by quantitative iTRAQ isobaric labeling; of these, 459 proteins were localized to the plasma membrane and 176 were localized to the thylakoid membrane. Surprisingly, we found over 2.5 times the number of unique proteins identified in the plasma membrane compared with the thylakoid membrane. This suggests that the protein composition of the thylakoid membrane is more homogeneous than the plasma membrane, consistent with the role of the plasma membrane in diverse cellular processes including protein trafficking and nutrient import, compared with a more specialized role for the thylakoid membrane in cellular energetics. Thus, our data clearly define the two membrane systems with distinct functions. Overall, the protein compositions of the Synechocystis 6803 plasma membrane and thylakoid membrane are quite similar to that of the plasma membrane of Escherichia coli and thylakoid membrane of Arabidopsis chloroplasts, respectively. Synechocystis 6803 can therefore be described as a Gram

  5. Species-specific differences of the spectroscopic properties of P700 - Analysis of the influence of non-conserved amino acid residues by site-directed mutagenesis of photosystem I from Chlamydomonas reinhardtii

    NARCIS (Netherlands)

    Witt, H.; Bordignon, E.; Carbonera, D.; Dekker, J.P.; Karapetyan, N.; Teutloff, C.; Webber, A.; Lubitz, W.; Schlodder, E.

    2003-01-01

    We applied optical spectroscopy, magnetic resonance techniques, and redox titrations to investigate the properties of the primary electron donor P700 in photosystem I (PS I) core complexes from cyanobacteria (Thermosynechococcus elongatus, Spirulina platensis, and Synechocystis sp. PCC 6803), algae

  6. ORF Alignment: NC_000911 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available ... dbj|BAA18187.1| sll1895 [Synechocystis sp. PCC 6803] ... Length = 103 ... Query: 2 ... LYQLVVDSPSFKKVIRLQNSCYSIGRHP...SNTIVIPSPQISRRHATLIKKINPNLDISFHI 61 ... LYQLVVDSPSFKKVIRLQNSCYSIGRHP...SNTIVIPSPQISRRHATLIKKINPNLDISFHI Sbjct: 1 ... LYQLVVDSPSFKKVIRLQNSCYSIGRHPSNTIVIPSPQISRRHATLIKKINPNLDISFHI 60 ...

  7. Downstream Processing of Synechocystis for Biofuel Production

    Science.gov (United States)

    Sheng, Jie

    Lipids and free fatty acids (FFA) from cyanobacterium Synechocystis can be used for biofuel (e.g. biodiesel or renewable diesel) production. In order to utilize and scale up this technique, downstream processes including culturing and harvest, cell disruption, and extraction were studied. Several solvents/solvent systems were screened for lipid extraction from Synechocystis. Chloroform + methanol-based Folch and Bligh & Dyer methods were proved to be "gold standard" for small-scale analysis due to their highest lipid recoveries that were confirmed by their penetration of the cell membranes, higher polarity, and stronger interaction with hydrogen bonds. Less toxic solvents, such as methanol and MTBE, or direct transesterification of biomass (without preextraction step) gave only slightly lower lipid-extraction yields and can be considered for large-scale application. Sustained exposure to high and low temperature extremes severely lowered the biomass and lipid productivity. Temperature stress also triggered changes of lipid quality such as the degree of unsaturation; thus, it affected the productivities and quality of Synechocystis-derived biofuel. Pulsed electric field (PEF) was evaluated for cell disruption prior to lipid extraction. A treatment intensity > 35 kWh/m3 caused significant damage to the plasma membrane, cell wall, and thylakoid membrane, and it even led to complete disruption of some cells into fragments. Treatment by PEF enhanced the potential for the low-toxicity solvent isopropanol to access lipid molecules during subsequent solvent extraction, leading to lower usage of isopropanol for the same extraction efficiency. Other cell-disruption methods also were tested. Distinct disruption effects to the cell envelope, plasma membrane, and thylakoid membranes were observed that were related to extraction efficiency. Microwave and ultrasound had significant enhancement of lipid extraction. Autoclaving, ultrasound, and French press caused significant

  8. Engineering cyanobacteria for photosynthetic production of 3-hydroxybutyrate directly from CO2.

    Science.gov (United States)

    Wang, Bo; Pugh, Shawn; Nielsen, David R; Zhang, Weiwen; Meldrum, Deirdre R

    2013-03-01

    (S)- and (R)-3-hydroxybutyrate (3HB) are precursors to synthesize the biodegradable plastics polyhydroxyalkanoates (PHAs) and many fine chemicals. To date, however, their production has been restricted to petroleum-based chemical industry and sugar-based microbial fermentation, limiting its sustainability and economical feasibility. With the ability to fix CO2 photosynthetically, cyanobacteria have attracted increasing interest as a biosynthesis platform to produce fuels and chemicals from alternative renewable resources. To this end, synthesis metabolic pathways have been constructed and optimized in cyanobacterium Synechocystis sp. PCC 6803 to photosynthetically produce (S)- and (R)-3HB directly from CO2. Both types of 3HB molecules were produced and readily secreted from Synechocystis cells without over-expression of transporters. Additional inactivation of the competing pathway by deleting slr1829 and slr1830 (encoding PHB polymerase) from the Synechocystis genome further promoted the 3HB production. Up to 533.4mg/L 3HB has been produced after photosynthetic cultivation of the engineered cyanobacterium Synechocystis TABd for 21 days. Further analysis indicated that the phosphate consumption during the photoautrophic growth and the concomitant elevated acetyl-CoA pool acted as a key driving force for 3HB biosynthesis in Synechocystis. For the first time, the study has demonstrated the feasibility of photosynthetic production of (S)- and (R)-3HB directly from sunlight and CO2. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Development of Synechocystis sp. PCC 6803 as a Phototrophic Cell Factory

    Directory of Open Access Journals (Sweden)

    Fuzhong Zhang

    2013-08-01

    Full Text Available Cyanobacteria (blue-green algae play profound roles in ecology and biogeochemistry. One model cyanobacterial species is the unicellular cyanobacterium Synechocystis sp. PCC 6803. This species is highly amenable to genetic modification. Its genome has been sequenced and many systems biology and molecular biology tools are available to study this bacterium. Recently, researchers have put significant efforts into understanding and engineering this bacterium to produce chemicals and biofuels from sunlight and CO2. To demonstrate our perspective on the application of this cyanobacterium as a photosynthesis-based chassis, we summarize the recent research on Synechocystis 6803 by focusing on five topics: rate-limiting factors for cell cultivation; molecular tools for genetic modifications; high-throughput system biology for genome wide analysis; metabolic modeling for physiological prediction and rational metabolic engineering; and applications in producing diverse chemicals. We also discuss the particular challenges for systems analysis and engineering applications of this microorganism, including precise characterization of versatile cell metabolism, improvement of product rates and titers, bioprocess scale-up, and product recovery. Although much progress has been achieved in the development of Synechocystis 6803 as a phototrophic cell factory, the biotechnology for “Compounds from Synechocystis” is still significantly lagging behind those for heterotrophic microbes (e.g., Escherichia coli.

  10. Phototaxis of Cyanobacteria under Complex Light Environments

    Directory of Open Access Journals (Sweden)

    Minsu Kim

    2017-04-01

    Full Text Available Photosynthetic bacteria are capable of producing their own food via photosynthesis. Unsurprisingly, they evolved the ability to move toward better light conditions (i.e., phototaxis. In a recent article in mBio, Chau et al. tuned the wavelength, flux, direction, and timing of light input and characterized the motility of the unicellular cyanobacterium Synechocystis sp. strain PCC6803 (R. M. W. Chau, D. Bhaya, and K. C. Huang, mBio 8:e02330-16, 2017, https://doi.org/10.1128/mBio.02330-16. The results revealed an intricate dependence of the motility on various light inputs, laying the fundamental groundwork toward understanding phototaxis under complex and dynamic light environments.

  11. UP Finder: A COBRA toolbox extension for identifying gene overexpression strategies for targeted overproduction

    Directory of Open Access Journals (Sweden)

    Xi Wang

    2017-12-01

    Full Text Available Overexpression of key genes is a basic strategy for overproducing target products via metabolic engineering. Traditionally, identifying those key genes/pathways largely relies on the knowledge of biochemistry and bioinformatics. In this study, a modeling tool named UP Finder was developed to facilitate the rapid identification of gene overexpression strategies. It was based on the COBRA toolbox under MATLAB environment. All the key gene/pathway targets are identified in one click after simply loading a Systems Biology Markup Language model and specifying a metabolite as the targeted product. The outputs are also quantitatively ranked to show the preference for determining overexpression strategies in pathway design. Analysis examples for overproducing lycopene precursor in Escherichia coli and fatty acyl-ACP in the cyanobacterium Synechocystis sp. PCC 6803 by the UP Finder showed high degree of agreement with the reported key genes in the literatures.

  12. Glycogen Production in Marine Cyanobacterial Strain Synechococcus sp. NKBG 15041c.

    Science.gov (United States)

    Badary, Amr; Takamatsu, Shouhei; Nakajima, Mitsuharu; Ferri, Stefano; Lindblad, Peter; Sode, Koji

    2018-01-12

    An important feature offered by marine cyanobacterial strains over freshwater strains is the capacity to grow in seawater, replacing the need for often-limited freshwater. However, there are only limited numbers of marine cyanobacteria that are available for genetic manipulation and bioprocess applications. The marine unicellular cyanobacteria Synechococcus sp. strain NKBG 15041c (NKBG15041c) has been extensively studied. Recombinant DNA technologies are available for this strain, and its genomic information has been elucidated. However, an investigation of carbohydrate production, such as glycogen production, would provide information for inevitable biofuel-related compound production, but it has not been conducted. In this study, glycogen production by marine cyanobacterium NKBG15041c was investigated under different cultivation conditions. NKBG15041c yielded up to 399 μg/ml/OD 730 when cells were cultivated for 168 h in nitrogen-depleted medium (marine BG11 ΔN ) after medium replacement (336 h after inoculation). Cultivation under nitrogen-limited conditions also yielded an accumulation of glycogen in NKBG15041c cells (1 mM NaNO 3 , 301 μg/ml/OD 730 ; 3 mM NaNO 3 , 393 μg/ml/OD 730 ; and 5 mM NaNO 3 , 328 μg/ml/OD 730 ) under ambient conditions. Transcriptional analyses were carried out for 13 putative genes responsible for glycogen synthesis and catabolism that were predicted based on homology analyses with Synechocystis sp. PCC 6803 (PCC6803) and Synechococcus sp. PCC7002 (PCC7002). The transcriptional analyses revealed that glycogen production in NKBG15041c under nitrogen-depleted conditions can be explained by the contribution of both increased carbon flux towards glycogen synthesis, similar to PCC6803 and PCC7002, and increased transcriptional levels of genes responsible for glycogen synthesis, which is different from the conventionally reported phenomenon, resulting in a relatively high amount of glycogen under ambient conditions compared to

  13. Genetically engineering Synechocystis sp. Pasteur Culture Collection 6803 for the sustainable production of the plant secondary metabolite p-coumaric acid.

    Science.gov (United States)

    Xue, Yong; Zhang, Yan; Cheng, Dan; Daddy, Soumana; He, Qingfang

    2014-07-01

    p-Coumaric acid is the precursor of phenylpropanoids, which are plant secondary metabolites that are beneficial to human health. Tyrosine ammonia lyase catalyzes the production of p-coumaric acid from tyrosine. Because of their photosynthetic ability and biosynthetic versatility, cyanobacteria are promising candidates for the production of certain plant metabolites, including phenylpropanoids. Here, we produced p-coumaric acid in a strain of transgenic cyanobacterium Synechocystis sp. Pasteur Culture Collection 6803 (hereafter Synechocystis 6803). Whereas a strain of Synechocystis 6803 genetically engineered to express sam8, a tyrosine ammonia lyase gene from the actinomycete Saccharothrix espanaensis, accumulated little or no p-coumaric acid, a strain that both expressed sam8 and lacked slr1573, a native hypothetical gene shown here to encode a laccase that oxidizes polyphenols, produced ∼82.6 mg/L p-coumaric acid, which was readily purified from the growth medium.

  14. Malonylome Analysis Reveals the Involvement of Lysine Malonylation in Metabolism and Photosynthesis in Cyanobacteria.

    Science.gov (United States)

    Ma, Yanyan; Yang, Mingkun; Lin, Xiaohuang; Liu, Xin; Huang, Hui; Ge, Feng

    2017-05-05

    As a recently validated reversible post translational modification, lysine malonylation regulates diverse cellular processes from bacteria to mammals, but its existence and function in photosynthetic organisms remain unknown. Cyanobacteria are the most ancient group of photosynthetic prokaryotes and contribute about 50% of the total primary production on Earth. Previously, we reported the lysine acetylome in the model cyanobacterium Synechocystis sp. PCC 6803 (Synechocystis). Here we performed the first proteomic survey of lysine malonylation in Synechocystis using highly accurate tandem mass spectrometry in combination with affinity purification. We identified 598 lysine malonylation sites on 339 proteins with high confidence in total. A bioinformatic analysis suggested that these malonylated proteins may play various functions and were distributed in diverse subcellular compartments. Among them, many malonylated proteins were involved in cellular metabolism. The functional significance of lysine malonylation in the metabolic enzyme activity of phosphoglycerate kinase (PGK) was determined by site-specific mutagenesis and biochemical studies. Interestingly, 27 proteins involved in photosynthesis were found to be malonylated for the first time, suggesting that lysine malonylation may be involved in photosynthesis. Thus our results provide the first lysine malonylome in a photosynthetic organism and suggest a previously unexplored role of lysine malonylation in the regulation of metabolic processes and photosynthesis in Synechocystis as well as in other photosynthetic organisms.

  15. Oxidative-stress detoxification and signalling in cyanobacteria: the crucial glutathione synthesis pathway supports the production of ergothioneine and ophthalmate.

    Science.gov (United States)

    Narainsamy, Kinsley; Farci, Sandrine; Braun, Emilie; Junot, Christophe; Cassier-Chauvat, Corinne; Chauvat, Franck

    2016-04-01

    Using genetics and metabolomics we investigated the synthesis (gshA and gshB genes) and catabolism (ggt) of the conserved antioxidant glutathione in the model cyanobacterium Synechocystis PCC6803. These three genes are crucial to Synechocystis, in agreement with the proposed invention of glutathione by ancient cyanobacteria to protect themselves against the toxicity of oxygen they produced through photosynthesis. Consistent with their indispensability, gshA and gshB also operate in the production of another antioxidant, ergothioneine, as well as of the glutathione analogues ophthalmate and norophthalmate. Furthermore, we show that glutathione, ophthalmate and norophthalmate are accumulated in cells stressed by glucose, and that the two glutathione-dependent glyoxalase enzymes operate in the protection against glucose and its catabolite methylglyoxal. These findings are interesting because ophthalmate and norophthalmate were observed only in mammals so far, where ophthalmate is regarded as a biomarker of glutathione depletion. Instead, our data suggest that ophthalmate and norophthalmate are stress-induced markers of cysteine depletion triggered by its accelerated incorporation into glutathione, to face its increased demand for detoxification purposes. Hence, Synechocystis is an attractive model for the analysis of the role of glutathione, ergothioneine, ophthalmate and norophthalmate, in signalling and detoxification of oxidants and metabolic by-products. © 2015 John Wiley & Sons Ltd.

  16. Over-production, renaturation and reconstitution of delta and epsilon subunits from chloroplast and cyanobacterial F1

    NARCIS (Netherlands)

    Steinemann, D.; Lill, H; Junge, Wolfgang; Engelbrecht, Siegfried

    1994-01-01

    We studied the functioning of chimeric F0F1-ATPases by replacing subunits delta and epsilon of spinach CF1 with their counterparts from Synechocystis sp. PCC 6803. The sequence identities between these subunits are 26 and 41%, respectively. For a systematic approach to such studies and later

  17. Accessibility controls selective degradation of photosystem II subunits by FtsH protease

    Czech Academy of Sciences Publication Activity Database

    Krynická, Vendula; Shao, S.; Nixon, P.J.; Komenda, Josef

    2015-01-01

    Roč. 1, č. 12 (2015), UNSP 15168 ISSN 2055-026X R&D Projects: GA MŠk(CZ) LO1416; GA ČR GBP501/12/G055 Institutional support: RVO:61388971 Keywords : SYNECHOCYSTIS SP PCC-6803 * DRIVEN SYNTHESIS * COMPLEX Subject RIV: EE - Microbiology, Virology

  18. Electric field effects on red chlorophylls, b-carotenes and P700 in cyanobacterial photosystem I complexes.

    NARCIS (Netherlands)

    Frese, R.N.; Palacios, M.A.; Azzizi, A.; van Stokkum, I.H.M.; Kruip, J.; Rögner, M.; Karapetyan, N.V.; Schlodder, E.; van Grondelle, R.; Dekker, J.P.

    2002-01-01

    We have probed the absorption changes due to an externally applied electric field (Stark effect) of Photosystem I (PSI) core complexes from the cyanobacteria Synechocystis sp. PCC 6803, Synechococcus elongatus and Spirulina platensis. The results reveal that the so-called C719 chlorophylls in S.

  19. Degradation of PsbO by the Deg protease HhoA Is thioredoxin dependent.

    Directory of Open Access Journals (Sweden)

    Irma N Roberts

    Full Text Available The widely distributed members of the Deg/HtrA protease family play an important role in the proteolysis of misfolded and damaged proteins. Here we show that the Deg protease rHhoA is able to degrade PsbO, the extrinsic protein of the Photosystem II (PSII oxygen-evolving complex in Synechocystis sp. PCC 6803 and in spinach. PsbO is known to be stable in its oxidized form, but after reduction by thioredoxin it became a substrate for recombinant HhoA (rHhoA. rHhoA cleaved reduced eukaryotic (specifically, spinach PsbO at defined sites and created distinct PsbO fragments that were not further degraded. As for the corresponding prokaryotic substrate (reduced PsbO of Synechocystis sp. PCC 6803, no PsbO fragments were observed. Assembly to PSII protected PsbO from degradation. For Synechocystis sp. PCC 6803, our results show that HhoA, HhoB, and HtrA are localized in the periplasma and/or at the thylakoid membrane. In agreement with the idea that PsbO could be a physiological substrate for Deg proteases, part of the cellular fraction of the three Deg proteases of Synechocystis sp. PCC 6803 (HhoA, HhoB, and HtrA was detected in the PSII-enriched membrane fraction.

  20. Protein (Cyanobacteria): 359322 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available ynechocystis sp. PCC 6803 MYFLLVTLVILVFPLLSIALEWTTSGNSQALVDVLARWFVFWGVGVRLFLAGVVQITKPSFTAEKILGVQSQDSLILVKELGIGNLAIASVALGSIFVNAWVLGAALAGGIFYLLAGINHILQPERNAKENYAMATDLFLGLLLGGILFFAWQP ...

  1. A Novel Redoxin in the Thylakoid Membrane Regulates the Titer of Photosystem I.

    Science.gov (United States)

    Zhu, Yuehui; Liberton, Michelle; Pakrasi, Himadri B

    2016-09-02

    In photosynthetic organisms like cyanobacteria and plants, the main engines of oxygenic photosynthesis are the pigment-protein complexes photosystem I (PSI) and photosystem II (PSII) located in the thylakoid membrane. In the cyanobacterium Synechocystis sp. PCC 6803, the slr1796 gene encodes a single cysteine thioredoxin-like protein, orthologs of which are found in multiple cyanobacterial strains as well as chloroplasts of higher plants. Targeted inactivation of slr1796 in Synechocystis 6803 resulted in compromised photoautotrophic growth. The mutant displayed decreased chlorophyll a content. These changes correlated with a decrease in the PSI titer of the mutant cells, whereas the PSII content was unaffected. In the mutant, the transcript levels of genes for PSI structural and accessory proteins remained unaffected, whereas the levels of PSI structural proteins were severely diminished, indicating that Slr1796 acts at a posttranscriptional level. Biochemical analysis indicated that Slr1796 is an integral thylakoid membrane protein. We conclude that Slr1796 is a novel regulatory factor that modulates PSI titer. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  2. Spatial separation of photosynthesis and ethanol production by cell type-specific metabolic engineering of filamentous cyanobacteria.

    Science.gov (United States)

    Ehira, Shigeki; Takeuchi, Takuto; Higo, Akiyoshi

    2018-02-01

    Cyanobacteria, which perform oxygenic photosynthesis, have drawn attention as hosts for the direct production of biofuels and commodity chemicals from CO 2 and H 2 O using light energy. Although cyanobacteria capable of producing diverse chemicals have been generated by metabolic engineering, anaerobic non-photosynthetic culture conditions are often necessary for their production. In this study, we conducted cell type-specific metabolic engineering of the filamentous cyanobacterium Anabaena sp. PCC 7120, which forms a terminally differentiated cell called a heterocyst with a semi-regular spacing of 10-15 cells. Because heterocysts are specialized cells for nitrogen fixation, the intracellular oxygen level of heterocysts is maintained very low even when adjacent cells perform oxygenic photosynthesis. Pyruvate decarboxylase of Zymomonas mobilis and alcohol dehydrogenase of Synechocystis sp. PCC 6803 were exclusively expressed in heterocysts. Ethanol production was concomitant with nitrogen fixation in genetically engineered Anabaena sp. PCC 7120. Engineering of carbon metabolism in heterocysts improved ethanol production, and strain ET14, with an extra copy of the invB gene expressed from a heterocyst-specific promoter, produced 130.9 mg L -1 of ethanol after 9 days. ET14 produced 1681.9 mg L -1 of ethanol by increasing the CO 2 supply. Ethanol production per heterocyst cell was approximately threefold higher than that per cell of unicellular cyanobacterium. This study demonstrates the potential of heterocysts for anaerobic production of biofuels and commodity chemicals under oxygenic photosynthetic conditions.

  3. Sulfur mobilization in cyanobacteria: the catalytic mechanism of L-cystine C-S lyase (C-DES) from synechocystis.

    Science.gov (United States)

    Campanini, Barbara; Schiaretti, Francesca; Abbruzzetti, Stefania; Kessler, Dorothea; Mozzarelli, Andrea

    2006-12-15

    Sulfur mobilization represents one of the key steps in ubiquitous Fe-S clusters assembly and is performed by a recently characterized set of proteins encompassing cysteine desulfurases, assembly factors, and shuttle proteins. Despite the evolutionary conservation of these proteins, some degree of variability among organisms was observed, which might reflect functional specialization. L-Cyst(e)ine lyase (C-DES), a pyridoxal 5'-phosphatedependent enzyme identified in the cyanobacterium Synechocystis, was reported to use preferentially cystine over cysteine with production of cysteine persulfide, pyruvate, and ammonia. In this study, we demonstrate that C-DES sequences are present in all cyanobacterial genomes and constitute a new family of sulfur-mobilizing enzymes, distinct from cysteine desulfurases. The functional properties of C-DES from Synechocystis sp. PCC 6714 were investigated under pre-steady-state and steady-state conditions. Single wavelength and rapid scanning stopped-flow kinetic data indicate that the internal aldimine reacts with cystine forming an external aldimine that rapidly decays to a transient quinonoid species and stable tautomers of the alpha-aminoacrylate Schiff base. In the presence of cysteine, the transient formation of a dipolar species precedes the selective and stable accumulation of the enolimine tautomer of the external aldimine, with no formation of the alpha-aminoacrylate Schiff base under reducing conditions. Effective sulfur mobilization from cystine might represent a mechanism that allows adaptation of cyanobacteria to different environmental conditions and to light-dark cycles.

  4. Phosphorus Physiology of the Marine Cyanobacterium Trichodesmium

    Science.gov (United States)

    2010-02-01

    Carribean ; Romans e al. 1994), the presence of high percentages of polyP in Trichodesmium from the Sargasso Sea is unlikely to be due to luxury uptake...2010-06 DOCTORAL DISSERTATION by Elizabeth Duncan Orchard February 2010 Phosphorus Physiology of the Marine Cyanobacterium Trichodesmium MIT/WHOI...2010-06 Phosphorus Physiology of the Marine Cyanobacterium Trichodesmium by Elizabeth Duncan Orchard Massachusetts Institute of Technology Cambridge

  5. Production of γ-linolenic acid and stearidonic acid by Synechococcus sp. PCC7002 containing cyanobacterial fatty acid desaturase genes

    Science.gov (United States)

    Dong, Xuewei; He, Qingfang; Peng, Zhenying; Yu, Jinhui; Bian, Fei; Li, Youzhi; Bi, Yuping

    2016-07-01

    Genetic modification is useful for improving the nutritional qualities of cyanobacteria. To increase the total unsaturated fatty acid content, along with the ratio of ω-3/ω-6 fatty acids, genetic engineering can be used to modify fatty acid metabolism. Synechococcus sp. PCC7002, a fast-growing cyanobacterium, does not contain a Δ6 desaturase gene and is therefore unable to synthesize γ-linolenic acid (GLA) and stearidonic acid (SDA), which are important in human health. In this work, we constructed recombinant vectors Syd6D, Syd15D and Syd6Dd15D to express the Δ15 desaturase and Δ6 desaturase genes from Synechocystis PCC6803 in Synechococcus sp. PCC7002, with the aim of expressing polyunsaturated fatty acids. Overexpression of the Δ15 desaturase gene in Synechococcus resulted in 5.4 times greater accumulation of α-linolenic acid compared with the wild-type while Δ6 desaturase gene expression produced both GLA and SDA. Co-expression of the two genes resulted in low-level accumulation of GLA but much larger amounts of SDA, accounting for as much to 11.64% of the total fatty acid content.

  6. Managing the Microbial Ecology of a Cyanobacteria-Based Photosynthetic Factory Direct!, Final Report for EE0006100

    Energy Technology Data Exchange (ETDEWEB)

    Rittmann, Bruce [Arizona State Univ., Tempe, AZ (United States); Krajmalnik‐Brown, Rosa [Arizona State Univ., Tempe, AZ (United States); Zevin, Alexander [Arizona State Univ., Tempe, AZ (United States); Nguyen, Binh [Arizona State Univ., Tempe, AZ (United States); Patel, Megha [Arizona State Univ., Tempe, AZ (United States)

    2015-02-28

    The grandest challenge facing human society today is providing large amounts of energy and industrial chemicals that are renewable and carbon-neutral. An outstanding opportunity lies in employing photosynthetic microorganisms, which have the potential to generate energy and chemical feedstock from sunlight and CO2 at rates 10 to 100 times greater than plants. Major challenges for solar-powered production using photosynthetic microorganisms are associated with the harvesting and downstream processing of biomass to yield the usable energy or material feedstock e.g. The technical challenges and costs of downstream processing could be avoided if, powered by solar energy, the photosynthetic microorganisms were to convert CO2 directly to the desired product, which they release for direct harvesting. This approach creates a true photosynthetic factory, our goal for Photosynthetic Factory Direct! Our team is able to genetically modify the cyanobacterium Synechocystis sp. PCC 6803 so that it produces and excretes a range of renewable energy and chemical products directly from CO2 and sunlight. Essential to realizing the potential of the photosynthetic factory is an engineered Advanced Photobioreactor (APBR) for reliable synthesis and harvest of the products.

  7. A novel potassium channel in photosynthetic cyanobacteria.

    Directory of Open Access Journals (Sweden)

    Manuela Zanetti

    Full Text Available Elucidation of the structure-function relationship of a small number of prokaryotic ion channels characterized so far greatly contributed to our knowledge on basic mechanisms of ion conduction. We identified a new potassium channel (SynK in the genome of the cyanobacterium Synechocystis sp. PCC6803, a photosynthetic model organism. SynK, when expressed in a K(+-uptake-system deficient E. coli strain, was able to recover growth of these organisms. The protein functions as a potassium selective ion channel when expressed in Chinese hamster ovary cells. The location of SynK in cyanobacteria in both thylakoid and plasmamembranes was revealed by immunogold electron microscopy and Western blotting of isolated membrane fractions. SynK seems to be conserved during evolution, giving rise to a TPK (two-pore K(+ channel family member which is shown here to be located in the thylakoid membrane of Arabidopsis. Our work characterizes a novel cyanobacterial potassium channel and indicates the molecular nature of the first higher plant thylakoid cation channel, opening the way to functional studies.

  8. Slowdown of surface diffusion during early stages of bacterial colonization

    Science.gov (United States)

    Vourc'h, T.; Peerhossaini, H.; Léopoldès, J.; Méjean, A.; Chauvat, F.; Cassier-Chauvat, C.

    2018-03-01

    We study the surface diffusion of the model cyanobacterium Synechocystis sp. PCC6803 during the incipient stages of cell contact with a glass surface in the dilute regime. We observe a twitching motility with alternating immobile tumble and mobile run periods, resulting in a normal diffusion described by a continuous-time random walk with a coefficient of diffusion D . Surprisingly, D is found to decrease with time down to a plateau. This is observed only when the cyanobacterial cells are able to produce released extracellular polysaccharides, as shown by a comparative study between the wild-type strain and various polysaccharides-depleted mutants. The analysis of the trajectories taken by the bacterial cells shows that the temporal characteristics of their intermittent motion depend on the instantaneous fraction of visited sites during diffusion. This describes quantitatively the time dependence of D , related to the progressive surface coverage by the polysaccharides. The observed slowdown of the surface diffusion may constitute a basic precursor mechanism for microcolony formation and provides clues for controlling biofilm formation.

  9. Hole burning study of cyanobacterial Photosystem II complexes differing in the content of small putative chlorophyll-binding proteins

    Energy Technology Data Exchange (ETDEWEB)

    Dedic, R. E-mail: roman@kchf-43.karlov.mff.cuni.cz; Promnares, K.; Psencik, J.; Svoboda, A.; Korinek, M.; Tichy, M.; Komenda, J.; Funk, C.; Hala, J

    2004-05-01

    This contribution presents low-temperature absorption, both broad-band and site-selective excited fluorescence, and persistent hole burning spectra of Photosystem II complexes from the Photosystem I-lacking strains of the cyanobacterium Synechocystis sp. PCC 6803 differing in the content of small putative chlorophyll-binding proteins (Scps). These proteins are homologous to light-harvesting complex of higher plants and may bind pigments. The excited state lifetimes of the complexes were determined from zero-phonon hole widths extrapolated to zero-burning dose. The area and spectral position of a phonon side-band with respect to the zero-phonon hole provided additional information concerning chlorophyll-protein coupling and the Stokes shift. Decrease of three absorption subbands at (670.0, 672.9, and 675.7 nm) in the Photosystem II isolated from the strain lacking ScpC and ScpD is in agreement with a hypothesis about the role of Scps in the chlorophyll binding. In addition, narrowing of the zero-phonon hole in Photosystem II without both Scps indicates slowering of the excitation energy transfer which may be explained by the absence of a protective excitation energy quenching related to the presence of Scps.

  10. A Practical Solution for 77 K Fluorescence Measurements Based on LED Excitation and CCD Array Detector.

    Directory of Open Access Journals (Sweden)

    Jacob Lamb

    Full Text Available The fluorescence emission spectrum of photosynthetic microorganisms at liquid nitrogen temperature (77 K provides important insights into the organization of the photosynthetic machinery of bacteria and eukaryotes, which cannot be observed at room temperature. Conventionally, to obtain such spectra, a large and costly table-top fluorometer is required. Recently portable, reliable, and largely maintenance-free instruments have become available that can be utilized to accomplish a wide variety of spectroscopy-based measurements in photosynthesis research. In this report, we show how to build such an instrument in order to record 77K fluorescence spectra. This instrument consists of a low power monochromatic light-emitting diode (LED, and a portable CCD array based spectrometer. The optical components are coupled together using a fiber optic cable, and a custom made housing that also supports a dewar flask. We demonstrate that this instrument facilitates the reliable determination of chlorophyll fluorescence emission spectra for the cyanobacterium Synechocystis sp. PCC 6803, and the green alga Chlamydomonas reinhardtii.

  11. Genetic engineering and metabolite profiling for overproduction of polyhydroxybutyrate in cyanobacteria.

    Science.gov (United States)

    Hondo, Sayaka; Takahashi, Masatoshi; Osanai, Takashi; Matsuda, Mami; Hasunuma, Tomohisa; Tazuke, Akio; Nakahira, Yoichi; Chohnan, Shigeru; Hasegawa, Morifumi; Asayama, Munehiko

    2015-11-01

    Genetic engineering and metabolite profiling for the overproduction of polyhydroxybutyrate (PHB), which is a carbon material in biodegradable plastics, were examined in the unicellular cyanobacterium Synechocystis sp. PCC 6803. Transconjugants harboring cyanobacterial expression vectors that carried the pha genes for PHB biosynthesis were constructed. The overproduction of PHB by the engineering cells was confirmed through microscopic observations using Nile red, transmission electron microscopy (TEM), or nuclear magnetic resonance (NMR). We successfully recovered PHB from transconjugants prepared from nitrogen-depleted medium without sugar supplementation in which PHB reached approximately 7% (w/w) of the dry cell weight, showing a value of 12-fold higher productivity in the transconjugant than that in the control strain. We also measured the intracellular levels of acetyl-CoA, acetoacetyl-CoA, and 3-hydroxybutyryl-CoA (3HB-CoA), which are intermediate products for PHB. The results obtained indicated that these products were absent or at markedly low levels when cells were subjected to the steady-state growth phase of cultivation under nitrogen depletion for the overproduction of bioplastics. Based on these results, efficient factors were discussed for the overproduction of PHB in recombinant cyanobacteria. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  12. Recapitulating the Structural Evolution of Redox Regulation in Adenosine 5'-Phosphosulfate Kinase from Cyanobacteria to Plants.

    Science.gov (United States)

    Herrmann, Jonathan; Nathin, David; Lee, Soon Goo; Sun, Tony; Jez, Joseph M

    2015-10-09

    In plants, adenosine 5'-phosphosulfate (APS) kinase (APSK) is required for reproductive viability and the production of 3'-phosphoadenosine 5'-phosphosulfate (PAPS) as a sulfur donor in specialized metabolism. Previous studies of the APSK from Arabidopsis thaliana (AtAPSK) identified a regulatory disulfide bond formed between the N-terminal domain (NTD) and a cysteine on the core scaffold. This thiol switch is unique to mosses, gymnosperms, and angiosperms. To understand the structural evolution of redox control of APSK, we investigated the redox-insensitive APSK from the cyanobacterium Synechocystis sp. PCC 6803 (SynAPSK). Crystallographic analysis of SynAPSK in complex with either APS and a non-hydrolyzable ATP analog or APS and sulfate revealed the overall structure of the enzyme, which lacks the NTD found in homologs from mosses and plants. A series of engineered SynAPSK variants reconstructed the structural evolution of the plant APSK. Biochemical analyses of SynAPSK, SynAPSK H23C mutant, SynAPSK fused to the AtAPSK NTD, and the fusion protein with the H23C mutation showed that the addition of the NTD and cysteines recapitulated thiol-based regulation. These results reveal the molecular basis for structural changes leading to the evolution of redox control of APSK in the green lineage from cyanobacteria to plants. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  13. Recapitulating the Structural Evolution of Redox Regulation in Adenosine 5′-Phosphosulfate Kinase from Cyanobacteria to Plants*

    Science.gov (United States)

    Herrmann, Jonathan; Nathin, David; Lee, Soon Goo; Sun, Tony; Jez, Joseph M.

    2015-01-01

    In plants, adenosine 5′-phosphosulfate (APS) kinase (APSK) is required for reproductive viability and the production of 3′-phosphoadenosine 5′-phosphosulfate (PAPS) as a sulfur donor in specialized metabolism. Previous studies of the APSK from Arabidopsis thaliana (AtAPSK) identified a regulatory disulfide bond formed between the N-terminal domain (NTD) and a cysteine on the core scaffold. This thiol switch is unique to mosses, gymnosperms, and angiosperms. To understand the structural evolution of redox control of APSK, we investigated the redox-insensitive APSK from the cyanobacterium Synechocystis sp. PCC 6803 (SynAPSK). Crystallographic analysis of SynAPSK in complex with either APS and a non-hydrolyzable ATP analog or APS and sulfate revealed the overall structure of the enzyme, which lacks the NTD found in homologs from mosses and plants. A series of engineered SynAPSK variants reconstructed the structural evolution of the plant APSK. Biochemical analyses of SynAPSK, SynAPSK H23C mutant, SynAPSK fused to the AtAPSK NTD, and the fusion protein with the H23C mutation showed that the addition of the NTD and cysteines recapitulated thiol-based regulation. These results reveal the molecular basis for structural changes leading to the evolution of redox control of APSK in the green lineage from cyanobacteria to plants. PMID:26294763

  14. Introducing extra NADPH consumption ability significantly increases the photosynthetic efficiency and biomass production of cyanobacteria.

    Science.gov (United States)

    Zhou, Jie; Zhang, Fuliang; Meng, Hengkai; Zhang, Yanping; Li, Yin

    2016-11-01

    Increasing photosynthetic efficiency is crucial to increasing biomass production to meet the growing demands for food and energy. Previous theoretical arithmetic analysis suggests that the light reactions and dark reactions are imperfectly coupled due to shortage of ATP supply, or accumulation of NADPH. Here we hypothesized that solely increasing NADPH consumption might improve the coupling of light reactions and dark reactions, thereby increasing the photosynthetic efficiency and biomass production. To test this hypothesis, an NADPH consumption pathway was constructed in cyanobacterium Synechocystis sp. PCC 6803. The resulting extra NADPH-consuming mutant grew much faster and achieved a higher biomass concentration. Analyses of photosynthesis characteristics showed the activities of photosystem II and photosystem I and the light saturation point of the NADPH-consuming mutant all significantly increased. Thus, we demonstrated that introducing extra NADPH consumption ability is a promising strategy to increase photosynthetic efficiency and to enable utilization of high-intensity lights. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  15. Detecting Molecular Properties by Various Laser-Based Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Hsin, Tse-Ming [Iowa State Univ., Ames, IA (United States)

    2007-01-01

    Four different laser-based techniques were applied to study physical and chemical characteristics of biomolecules and dye molecules. These techniques are liole burning spectroscopy, single molecule spectroscopy, time-resolved coherent anti-Stokes Raman spectroscopy and laser-induced fluorescence microscopy. Results from hole burning and single molecule spectroscopy suggested that two antenna states (C708 & C714) of photosystem I from cyanobacterium Synechocystis PCC 6803 are connected by effective energy transfer and the corresponding energy transfer time is ~6 ps. In addition, results from hole burning spectroscopy indicated that the chlorophyll dimer of the C714 state has a large distribution of the dimer geometry. Direct observation of vibrational peaks and evolution of coumarin 153 in the electronic excited state was demonstrated by using the fs/ps CARS, a variation of time-resolved coherent anti-Stokes Raman spectroscopy. In three different solvents, methanol, acetonitrile, and butanol, a vibration peak related to the stretch of the carbonyl group exhibits different relaxation dynamics. Laser-induced fluorescence microscopy, along with the biomimetic containers-liposomes, allows the measurement of the enzymatic activity of individual alkaline phosphatase from bovine intestinal mucosa without potential interferences from glass surfaces. The result showed a wide distribution of the enzyme reactivity. Protein structural variation is one of the major reasons that are responsible for this highly heterogeneous behavior.

  16. Metals in cyanobacteria: analysis of the copper, nickel, cobalt and arsenic homeostasis mechanisms.

    Science.gov (United States)

    Huertas, María José; López-Maury, Luis; Giner-Lamia, Joaquín; Sánchez-Riego, Ana María; Florencio, Francisco Javier

    2014-12-09

    Traces of metal are required for fundamental biochemical processes, such as photosynthesis and respiration. Cyanobacteria metal homeostasis acquires an important role because the photosynthetic machinery imposes a high demand for metals, making them a limiting factor for cyanobacteria, especially in the open oceans. On the other hand, in the last two centuries, the metal concentrations in marine environments and lake sediments have increased as a result of several industrial activities. In all cases, cells have to tightly regulate uptake to maintain their intracellular concentrations below toxic levels. Mechanisms to obtain metal under limiting conditions and to protect cells from an excess of metals are present in cyanobacteria. Understanding metal homeostasis in cyanobacteria and the proteins involved will help to evaluate the use of these microorganisms in metal bioremediation. Furthermore, it will also help to understand how metal availability impacts primary production in the oceans. In this review, we will focus on copper, nickel, cobalt and arsenic (a toxic metalloid) metabolism, which has been mainly analyzed in model cyanobacterium Synechocystis sp. PCC 6803.

  17. Destruction of Raman biosignatures by ionising radiation and the implications for life detection on Mars.

    Science.gov (United States)

    Dartnell, Lewis R; Page, Kristian; Jorge-Villar, Susana E; Wright, Gary; Munshi, Tasnim; Scowen, Ian J; Ward, John M; Edwards, Howell G M

    2012-04-01

    Raman spectroscopy has proven to be a very effective approach for the detection of microorganisms colonising hostile environments on Earth. The ExoMars rover, due for launch in 2018, will carry a Raman laser spectrometer to analyse samples of the martian subsurface collected by the probe's 2-m drill in a search for similar biosignatures. The martian surface is unprotected from the flux of cosmic rays, an ionising radiation field that will degrade organic molecules and so diminish and distort the detectable Raman signature of potential martian microbial life. This study employs Raman spectroscopy to analyse samples of two model organisms, the cyanobacterium Synechocystis sp. PCC 6803 and the extremely radiation resistant polyextremophile Deinococcus radiodurans, that have been exposed to increasing doses of ionising radiation. The three most prominent peaks in the Raman spectra are from cellular carotenoids: deinoxanthin in D. radiodurans and β-carotene in Synechocystis. The degradative effect of ionising radiation is clearly seen, with significant diminishment of carotenoid spectral peak heights after 15 kGy and complete erasure of Raman biosignatures by 150 kGy of ionising radiation. The Raman signal of carotenoid in D. radiodurans diminishes more rapidly than that of Synechocystis, believed to be due to deinoxanthin acting as a superior scavenger of radiolytically produced reactive oxygen species, and so being destroyed more quickly than the less efficient antioxidant β-carotene. This study highlights the necessity for further experimental work on the manner and rate of degradation of Raman biosignatures by ionising radiation, as this is of prime importance for the successful detection of microbial life in the martian near subsurface.

  18. Improving cyanobacterail O2-tolerance using CBS hydrogenase for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Maness, Pin-Ching [National Renewable Energy Lab. (NREL), Golden, CO (United States); Eckert, Carrie [National Renewable Energy Lab. (NREL), Golden, CO (United States); Wawrousek, Karen [National Renewable Energy Lab. (NREL), Golden, CO (United States); Noble, Scott [National Renewable Energy Lab. (NREL), Golden, CO (United States); Pennington, Grant [National Renewable Energy Lab. (NREL), Golden, CO (United States); Yu, Jianping [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-11-11

    Cyanobacterial H2 production is a viable path to renewable H2 with water serving as the electron donor and sunlight the energy source. A grand challenge is the sensitivity of the underlying hydrogenase to O2, the latter an inherent byproduct of oxygenic photosynthesis. This challenge has been identified as a technical barrier in the Fuel Cell Technologies Office (FCTO) Multi-year Research, Development and Deployment Plan. One solution is to express in cyanobacterium an O2-tolerant hydrogenase to circumvent this barrier. We have uncovered an O2-tolerant hydrogenase from a photosynthetic bacterium Rubrivivax gelatinosus CBS (Casa Bonita Strain; hereafter “CBS”) with a half-life near 21 h when exposed to ambient O2. We sequenced the CBS genome and identified two sets of maturation machineries hyp1 and hyp2. Transcripts expression analysis and mutagenesis revealed that hyp1 is responsible for the assembly of the O2-tolerant CO-oxidation (Coo) hydrogenase and hyp2 is involved in the maturation of a H2-uptake hydrogenase. The structural genes encoding the O2-tolerant hydrogenase (cooLXUH) and maturation genes hyp1FABCDE were therefore cloned and expressed in the model cyanobacterium Synechocystis sp. PCC 6803. We obtained several recombinants displaying hydrogenase activity in a Synechocystis host lacking background activity, suggesting that the CBS hydrogenase is active in Synechocystis. Yet the activity is extremely low. To ensure balanced protein expression, we systematically optimized heterologous expression of 10 CBS genes by using stronger promoters and better ribosome binding site. Moreover we attempted the expression of cooM and cooK genes, verified to be important in CBS to afford activity. CooM is a very large protein and both CooM and CooK are membrane-associated. These properties limited our success in expressing both genes in Synechocystis, although they

  19. Extracellular glycoconjugates produced by cyanobacterium Wollea saccata

    Czech Academy of Sciences Publication Activity Database

    Ray, B.; Bandyopadhyay, S. S.; Capek, P.; Kopecký, Jiří; Hindák, F.; Lukavský, Jaromír

    2011-01-01

    Roč. 48, č. 4 (2011), s. 553-557 ISSN 0141-8130 Institutional research plan: CEZ:AV0Z50200510; CEZ:AV0Z60050516 Keywords : Cyanobacterium * Wollea saccata * Mucilage Subject RIV: CE - Biochemistry Impact factor: 2.453, year: 2011

  20. Growth Characteristics of an Estuarine Heterocystous Cyanobacterium

    NARCIS (Netherlands)

    Guimarães, P.; Yunes, J.S.; Cretoiu, M.S.; Stal, L.J.

    2017-01-01

    A new estuarine filamentous heterocystous cyanobacterium was isolated from intertidal sediment of the Lagoa dos Patos estuary (Brazil). The isolate may represent a new genus related to Cylindrospermopsis. While the latter is planktonic, contains gas vesicles, and is toxic, the newly isolated strain

  1. Photoacclimation of cultured strains of the cyanobacterium

    NARCIS (Netherlands)

    Bañares-España, E.; Kromkamp, J.C.; López-Rodas, V.; Costas, E.; Flores-Moya, A.

    2013-01-01

    The cyanobacterium Microcystis aeruginosa forms blooms that can consist of colonies. We have investigated how M.aeruginosa acclimatizes to changing light conditions such as can occur during blooms. Three different strains were exposed to two irradiance levels: lower (LL) and higher (HL) than the

  2. Nitrogen uptake dynamics of a persistent cyanobacterium ...

    African Journals Online (AJOL)

    Worldwide, persistent cyanobacterial blooms are becoming more frequent and are often associated with effects of global climate change. In June 2009, a widespread bloom of the unicellular cyanobacterium, Cyanothece sp., appeared in North Lake and False Bay of Lake St Lucia – a large (360 km2) estuarine lake system ...

  3. Algal photosynthesis as the primary driver for a sustainable development in energy, feed, and food production.

    Science.gov (United States)

    Anemaet, Ida G; Bekker, Martijn; Hellingwerf, Klaas J

    2010-11-01

    High oil prices and global warming that accompany the use of fossil fuels are an incentive to find alternative forms of energy supply. Photosynthetic biofuel production represents one of these since for this, one uses renewable resources. Sunlight is used for the conversion of water and CO₂ into biomass. Two strategies are used in parallel: plant-based production via sugar fermentation into ethanol and biodiesel production through transesterification. Both, however, exacerbate other problems, including regional nutrient balancing and the world's food supply, and suffer from the modest efficiency of photosynthesis. Maximizing the efficiency of natural and engineered photosynthesis is therefore of utmost importance. Algal photosynthesis is the system of choice for this particularly for energy applications. Complete conversion of CO₂ into biomass is not necessary for this. Innovative methods of synthetic biology allow one to combine photosynthetic and fermentative metabolism via the so-called Photanol approach to form biofuel directly from Calvin cycle intermediates through use of the naturally transformable cyanobacterium Synechocystis sp. PCC 6803. Beyond providing transport energy and chemical feedstocks, photosynthesis will continue to be used for food and feed applications. Also for this application, arguments of efficiency will become more and more important as the size of the world population continues to increase. Photosynthetic cells can be used for food applications in various innovative forms, e.g., as a substitute for the fish proteins in the diet supplied to carnivorous fish or perhaps--after acid hydrolysis--as a complex, animal-free serum for growth of mammalian cells in vitro.

  4. Nitrogen-Dependent Carbon Fixation by Picoplankton In Culture and in the Mississippi River

    Energy Technology Data Exchange (ETDEWEB)

    Aubrey Smith; Marguerite W. Coomes; Thomas E. Smith

    2005-04-30

    The pepc gene, which encodes phosphoenolpyruvate carboxylase (PEPC), of the marine cyanobacterium Synechococcus PCC 7002, was isolated and sequenced. PEPC is an anaplerotic enzyme, but it may also contribute to overall CO2 fixation through β-carboxylation reactions. A consensus sequence generated by aligning the pepc genes of Anabaena variabilis, Anacystis nidulans and Synechocystis PCC 6803 was used to design two sets of primers that were used to amplify segments of Synechococcus PCC 7002 pepc. In order to isolate the gene, the sequence of the PCR product was used to search for the pepc nucleotide sequence from the publicly available genome of Synechococcus PCC 7002. At the time, the genome for this organism had not been completed although sequences of a significant number of its fragments are available in public databases. Thus, the major challenge was to find the pepc gene among those fragments and to complete gaps as necessary. Even though the search did not yield the complete gene, PCR primers were designed to amplify a DNA fragment using a high fidelity thermostable DNA polymerase. An open reading frame (ORF) consisting of 2988 base pairs coding for 995 amino acids was found in the 3066 bp PCR product. The pepc gene had a GC content of 52% and the deduced protein had a calculated molecular mass of 114,049 Da. The amino acid sequence was closely related to that of PEPC from other cyanobacteria, exhibiting 59-61% identity. The sequence differed significantly from plant and E. coli PEPC with only 30% homology. However, comparing the Synechococcus PCC 7002 sequence to the recently resolved E. coli PEPC revealed that most of the essential domains and amino acids involved in PEPC activity were shared by both proteins. The recombinant Synechococcus PCC 7002 PEPC was expressed in E. coli.

  5. Structure of Psb29/Thf1 and its association with the FtsH protease complex involved in photosystem II repair in cyanobacteria.

    Science.gov (United States)

    Bec Ková, Martina; Yu, Jianfeng; Krynická, Vendula; Kozlo, Amanda; Shao, Shengxi; Koník, Peter; Komenda, Josef; Murray, James W; Nixon, Peter J

    2017-09-26

    One strategy for enhancing photosynthesis in crop plants is to improve their ability to repair photosystem II (PSII) in response to irreversible damage by light. Despite the pivotal role of thylakoid-embedded FtsH protease complexes in the selective degradation of PSII subunits during repair, little is known about the factors involved in regulating FtsH expression. Here we show using the cyanobacterium Synechocystis sp. PCC 6803 that the Psb29 subunit, originally identified as a minor component of His-tagged PSII preparations, physically interacts with FtsH complexes in vivo and is required for normal accumulation of the FtsH2/FtsH3 hetero-oligomeric complex involved in PSII repair. We show using X-ray crystallography that Psb29 from Thermosynechococcus elongatus has a unique fold consisting of a helical bundle and an extended C-terminal helix and contains a highly conserved region that might be involved in binding to FtsH. A similar interaction is likely to occur in Arabidopsis chloroplasts between the Psb29 homologue, termed THF1, and the FTSH2/FTSH5 complex. The direct involvement of Psb29/THF1 in FtsH accumulation helps explain why THF1 is a target during the hypersensitive response in plants induced by pathogen infection. Downregulating FtsH function and the PSII repair cycle via THF1 would contribute to the production of reactive oxygen species, the loss of chloroplast function and cell death.This article is part of the themed issue 'Enhancing photosynthesis in crop plants: targets for improvement'. © 2017 The Authors.

  6. Comparison of excitation energy transfer in cyanobacterial photosystem I in solution and immobilized on conducting glass.

    Science.gov (United States)

    Szewczyk, Sebastian; Giera, Wojciech; D'Haene, Sandrine; van Grondelle, Rienk; Gibasiewicz, Krzysztof

    2017-05-01

    Excitation energy transfer in monomeric and trimeric forms of photosystem I (PSI) from the cyanobacterium Synechocystis sp. PCC 6803 in solution or immobilized on FTO conducting glass was compared using time-resolved fluorescence. Deposition of PSI on glass preserves bi-exponential excitation decay of ~4-7 and ~21-25 ps lifetimes characteristic of PSI in solution. The faster phase was assigned in part to photochemical quenching (charge separation) of excited bulk chlorophylls and in part to energy transfer from bulk to low-energy (red) chlorophylls. The slower phase was assigned to photochemical quenching of the excitation equilibrated over bulk and red chlorophylls. The main differences between dissolved and immobilized PSI (iPSI) are: (1) the average excitation decay in iPSI is about 11 ps, which is faster by a few ps than for PSI in solution due to significantly faster excitation quenching of bulk chlorophylls by charge separation (~10 ps instead of ~15 ps) accompanied by slightly weaker coupling of bulk and red chlorophylls; (2) the number of red chlorophylls in monomeric PSI increases twice-from 3 in solution to 6 after immobilization-as a result of interaction with neighboring monomers and conducting glass; despite the increased number of red chlorophylls, the excitation decay accelerates in iPSI; (3) the number of red chlorophylls in trimeric PSI is 4 (per monomer) and remains unchanged after immobilization; (4) in all the samples under study, the free energy gap between mean red (emission at ~710 nm) and mean bulk (emission at ~686 nm) emitting states of chlorophylls was estimated at a similar level of 17-27 meV. All these observations indicate that despite slight modifications, dried PSI complexes adsorbed on the FTO surface remain fully functional in terms of excitation energy transfer and primary charge separation that is particularly important in the view of photovoltaic applications of this photosystem.

  7. Protein-folding location can regulate manganese-binding versus copper- or zinc-binding.

    Science.gov (United States)

    Tottey, Steve; Waldron, Kevin J; Firbank, Susan J; Reale, Brian; Bessant, Conrad; Sato, Katsuko; Cheek, Timothy R; Gray, Joe; Banfield, Mark J; Dennison, Christopher; Robinson, Nigel J

    2008-10-23

    Metals are needed by at least one-quarter of all proteins. Although metallochaperones insert the correct metal into some proteins, they have not been found for the vast majority, and the view is that most metalloproteins acquire their metals directly from cellular pools. However, some metals form more stable complexes with proteins than do others. For instance, as described in the Irving-Williams series, Cu(2+) and Zn(2+) typically form more stable complexes than Mn(2+). Thus it is unclear what cellular mechanisms manage metal acquisition by most nascent proteins. To investigate this question, we identified the most abundant Cu(2+)-protein, CucA (Cu(2+)-cupin A), and the most abundant Mn(2+)-protein, MncA (Mn(2+)-cupin A), in the periplasm of the cyanobacterium Synechocystis PCC 6803. Each of these newly identified proteins binds its respective metal via identical ligands within a cupin fold. Consistent with the Irving-Williams series, MncA only binds Mn(2+) after folding in solutions containing at least a 10(4) times molar excess of Mn(2+) over Cu(2+) or Zn(2+). However once MncA has bound Mn(2+), the metal does not exchange with Cu(2+). MncA and CucA have signal peptides for different export pathways into the periplasm, Tat and Sec respectively. Export by the Tat pathway allows MncA to fold in the cytoplasm, which contains only tightly bound copper or Zn(2+) (refs 10-12) but micromolar Mn(2+) (ref. 13). In contrast, CucA folds in the periplasm to acquire Cu(2+). These results reveal a mechanism whereby the compartment in which a protein folds overrides its binding preference to control its metal content. They explain why the cytoplasm must contain only tightly bound and buffered copper and Zn(2+).

  8. Molecular cloning and functional analyses of glutathione peroxidase homologous genes from Chlorella sp. NJ-18.

    Science.gov (United States)

    Wang, Xin; Xu, Xudong

    2012-06-10

    Photosynthetic organisms often encounter oxidative stresses due to changes of environmental conditions. In this study, two glutathione peroxidase (GPX) homologous genes, namely NJ-18Gpx1 and NJ-18Gpx2, were identified in Chlorella sp. NJ-18, a single-celled green alga. The two NJ-18Gpx genes can produce 2 or 3 transcript variants by alternative splicing, predicted to encode 4 non-selenium GPX proteins (NS-GPX). Expression of the two genes was analyzed by quantitative RT-PCR in Chlorella sp. NJ-18 exposed to various treatments known to generate reactive oxygen species. Neutral red, a singlet oxygen-generating photosensitizer, significantly increased the expression of NJ-18Gpx1 within 5 h. Exposure of algal culture to UV-B for 3h caused up-regulation of mRNA levels of NJ-18Gpx1 and NJ-18Gpx2 by 4- and 50-folds, respectively. Similar to CrGPX5 and CrGPX3 in Chlamydomonas reinhardtii, purified recombinant NJ-18GPXs showed activities of thioredoxin-dependent peroxidases that catalyze the reduction of hydrogen peroxide and organic hydroperoxides. The V(max) values for NJ-18GPX1 toward different peroxides were approximately 10-fold higher than those for NJ-18GPX2. In addition, overexpression of NJ-18Gpx1 in Synechocystis sp. PCC 6803, a cyanobacterium, enhanced its tolerance to neutral red and H(2)O(2). These results indicate that NJ-18GPXs can act as efficient peroxide scavengers protecting cells from oxidative damages in Chlorella. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Prerequisite for highly efficient isoprenoid production by cyanobacteria discovered through the over-expression of 1-deoxy-d-xylulose 5-phosphate synthase and carbon allocation analysis.

    Science.gov (United States)

    Kudoh, Kai; Kawano, Yusuke; Hotta, Shingo; Sekine, Midori; Watanabe, Takafumi; Ihara, Masaki

    2014-07-01

    Cyanobacteria have recently been receiving considerable attention owing to their potential as photosynthetic producers of biofuels and biomaterials. Here, we focused on the production of isoprenoids by cyanobacteria, and aimed to provide insight into metabolic engineering design. To this end, we examined the over-expression of a key enzyme in 2-C-methyl-d-erythritol 4-phosphate (MEP) pathway, 1-deoxy-d-xylulose 5-phosphate synthase (DXS) in the cyanobacterium Synechocystis sp. PCC6803. In the DXS-over-expression strain (Dxs_ox), the mRNA and protein levels of DXS were 4-times and 1.5-times the levels in the wild-type (WT) strain, respectively. The carotenoid content of the Dxs_ox strain (8.4 mg/g dry cell weight [DCW]) was also up to 1.5-times higher than that in the WT strain (5.6 mg/g DCW), whereas the glycogen content dramatically decreased to an undetectable level. These observations suggested that the carotenoid content in the Dxs_ox strain was increased by consuming glycogen, which is a C-storage compound in cyanobacteria. We also quantified the total sugar (145 and 104 mg/g DCW), total fatty acids (31 and 24 mg/g DCW) and total protein (200 and 240 mg/g DCW) content in the WT and Dxs_ox strains, respectively, which were much higher than the carotenoid content. In particular, approximately 54% of the proteins were phycobiliproteins. This study demonstrated the major destinations of carbon flux in cyanobacteria, and provided important insights into metabolic engineering. Target yield can be improved through optimization of gene expression, the DXS protein stabilization, cell propagation depression and restriction of storage compound synthesis. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  10. Electron self-exchange in hemoglobins revealed by deutero-hemin substitution.

    Science.gov (United States)

    Athwal, Navjot Singh; Alagurajan, Jagannathan; Sturms, Ryan; Fulton, D Bruce; Andreotti, Amy H; Hargrove, Mark S

    2015-09-01

    Hemoglobins (phytoglobins) from rice plants (nsHb1) and from the cyanobacterium Synechocystis (PCC 6803) (SynHb) can reduce hydroxylamine with two electrons to form ammonium. The reaction requires intermolecular electron transfer between protein molecules, and rapid electron self-exchange might play a role in distinguishing these hemoglobins from others with slower reaction rates, such as myoglobin. A relatively rapid electron self-exchange rate constant has been measured for SynHb by NMR, but the rate constant for myoglobin is equivocal and a value for nsHb1 has not yet been measured. Here we report electron self-exchange rate constants for nsHb1 and Mb as a test of their role in hydroxylamine reduction. These proteins are not suitable for analysis by NMR ZZ exchange, so a method was developed that uses cross-reactions between each hemoglobin and its deutero-hemin substituted counterpart. The resulting electron transfer is between identical proteins with low driving forces and thus closely approximates true electron self-exchange. The reactions can be monitored spectrally due to the distinct spectra of the prosthetic groups, and from this electron self-exchange rate constants of 880 (SynHb), 2900 (nsHb1), and 0.05M(-1) s(-1) (Mb) have been measured for each hemoglobin. Calculations of cross-reactions using these values accurately predict hydroxylamine reduction rates for each protein, suggesting that electron self-exchange plays an important role in the reaction. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Cyanobacterial carbon metabolism: Fluxome plasticity and oxygen dependence

    DEFF Research Database (Denmark)

    Wan, Ni; Delorenzo, Drew M.; He, Lian

    2017-01-01

    Synechocystis sp. strain PCC 6803 has been widely used as a photo-biorefinery chassis. Based on its genome annotation, this species contains a complete TCA cycle, an Embden-Meyerhof-Parnas pathway (EMPP), an oxidative pentose phosphate pathway (OPPP), and an Entner-Doudoroff pathway (EDP). To eva......Synechocystis sp. strain PCC 6803 has been widely used as a photo-biorefinery chassis. Based on its genome annotation, this species contains a complete TCA cycle, an Embden-Meyerhof-Parnas pathway (EMPP), an oxidative pentose phosphate pathway (OPPP), and an Entner-Doudoroff pathway (EDP...... through the TCA cycle and the malic shunt. Independent knockouts of 6-phosphogluconate dehydrogenase (gnd) and malic enzyme (me) corroborated these results, as neither mutant could grow under dark heterotrophic conditions. Our data also indicate that Synechocystis 6803 metabolism relies upon oxidative...... phosphorylation to generate ATP from NADPH under dark or insufficient light conditions. The pool sizes of intermediates in the TCA cycle, particularly acetyl-CoA, were found to be several fold lower in Synechocystis 6803 (compared to E. coli metabolite pool sizes), while its sugar phosphate intermediates were...

  12. The ispB gene encoding octaprenyl diphosphate synthase is essential for growth of Escherichia coli.

    OpenAIRE

    Okada, K; Minehira, M; Zhu, X; Suzuki, K; Nakagawa, T; Matsuda, H; Kawamukai, M

    1997-01-01

    The Escherichia coli ispB gene encoding octaprenyl diphosphate synthase is responsible for the synthesis of the side chain of isoprenoid quinones. We tried to construct an E. coli ispB-disrupted mutant but could not isolate the chromosomal ispB disrupted mutant unless the ispB gene or its homolog was supplied on a plasmid. The chromosomal ispB disruptants that harbored plasmids carrying the ispB homologs from Haemophilus influenzae and Synechocystis sp. strain PCC6803 produced mainly ubiquino...

  13. Cyanobacteria contain a structural homologue of the Hfq protein with altered RNA binding properties

    DEFF Research Database (Denmark)

    Bøggild, Andreas; Overgaard, Martin; Valentin-Hansen, Poul

    2009-01-01

    regulating mRNA turnover in eukaryotes. However, bacterial Hfq proteins are homohexameric, whereas eukaryotic Sm/Lsm proteins are heteroheptameric. Recently, Hfq proteins with poor sequence conservation were identified in archaea and cyanobacteria. In this article, we describe crystal structures of the Hfq...... proteins from the cyanobacteria Synechocystis sp. PCC 6803 and Anabaena PCC 7120 at 1.3 and 2.3 A resolution, respectively, and show that they retain the classic Sm fold despite low sequence conservation. In addition, the intersubunit contacts and RNA-binding site are divergent, and we show biochemically...

  14. Cyanobacteria contain a structural homologue of the Hfq protein with altered RNA-binding properties

    DEFF Research Database (Denmark)

    Bøggild, Andreas; Overgaard, Martin; Valentin-Hansen, Poul

    2009-01-01

    regulating mRNA turnover in eukaryotes. However, bacterial Hfq proteins are homohexameric, whereas eukaryotic Sm/Lsm proteins are heteroheptameric. Recently, Hfq proteins with poor sequence conservation were identified in archaea and cyanobacteria. In this article, we describe crystal structures of the Hfq...... proteins from the cyanobacteria Synechocystis sp. PCC 6803 and Anabaena PCC 7120 at 1.3 and 2.3 A resolution, respectively, and show that they retain the classic Sm fold despite low sequence conservation. In addition, the intersubunit contacts and RNA-binding site are divergent, and we show biochemically...

  15. Las cianobacterias y su percepción del medio. Adaptación a la fuente de nitrógeno, cambios redox y metales pesados

    OpenAIRE

    Florencio, F.J.

    2009-01-01

    Las cianobacterias constituyen un grupo de bacterias con una cualidad singular, la de realizar una fotosíntesis oxigénica al igual que las plantas y algas. Su amplia diversidad y capacidad de adaptación han hecho que estos organismos ocupen con gran éxito nichos ecológicos muy diversos. El estudio de esta capacidad de adaptación mediante la utilización de algunas cianobacterias modelos, como es el caso de Synechocystis sp PCC 6803, han permitido estudiar a nivel molecular procesos...

  16. Photosystem I from the unusual cyanobacterium Gloeobacter violaceus

    NARCIS (Netherlands)

    Mangels, D.; Kruip, J.; Berry, S.; Rögner, M.; Boekema, E.J.; Koenig, F.

    2002-01-01

    Photosystem I (PS I) from the primitive cyanobacterium Gloeobacter violaceus has been purified and characterised. Despite the fact that the isolated complexes have the same subunit composition as complexes from other cyanobacteria, the amplitude of flash-induced absorption difference spectra

  17. Antimicrobial and Cytotoxic Assessment of Marine Cyanobacteria - Synechocystis and Synechococcus

    Directory of Open Access Journals (Sweden)

    Vitor M. Vasconcelos

    2008-01-01

    Full Text Available Aqueous extracts and organic solvent extracts of isolated marine cyanobacteria strains were tested for antimicrobial activity against a fungus, Gram-positive and Gram-negative bacteria and for cytotoxic activity against primary rat hepatocytes and HL-60 cells. Antimicrobial activity was based on the agar diffusion assay. Cytotoxic activity was measured by apoptotic cell death scored by cell surface evaluation and nuclear morphology. A high percentage of apoptotic cells were observed for HL-60 cells when treated with cyanobacterial organic extracts. Slight apoptotic effects were observed in primary rat hepatocytes when exposed to aqueous cyanobacterial extracts. Nine cyanobacteria strains were found to have antibiotic activity against two Gram-positive bacteria, Clavibacter michiganensis subsp. insidiosum and Cellulomonas uda. No inhibitory effects were found against the fungus Candida albicans and Gram-negative bacteria. Marine Synechocystis and Synechococcus extracts induce apoptosis in eukaryotic cells and cause inhibition of Gram-positive bacteria. The different activity in different extracts suggests different compounds with different polarities.

  18. Environmental Factors Influencing Blooms of a Neurotoxic Stigonematalan Cyanobacterium Responsible for Avian Vacuolar Myelinopathy

    Science.gov (United States)

    2013-01-01

    filamentous , heterocystous, true branching cyanobacterium. Morphological characteristics place the cyanobacterium in section V, order Stigonematales. All...periods of desiccation. In general, with increasing temperature, the algal group with the highest growth rate changes from diatoms to green algae to...UCB) (Wilde et al. 2005, Williams et al. 2007). ERDC/TN ANSRP-13-1 January 2013 3 This UCB is a true-branching filamentous cyanobacterium that

  19. Colony formation in the cyanobacterium Microcystis.

    Science.gov (United States)

    Xiao, Man; Li, Ming; Reynolds, Colin S

    2018-02-22

    Morphological evolution from a unicellular to multicellular state provides greater opportunities for organisms to attain larger and more complex living forms. As the most common freshwater cyanobacterial genus, Microcystis is a unicellular microorganism, with high phenotypic plasticity, which forms colonies and blooms in lakes and reservoirs worldwide. We conducted a systematic review of field studies from the 1990s to 2017 where Microcystis was dominant. Microcystis was detected as the dominant genus in waterbodies from temperate to subtropical and tropical zones. Unicellular Microcystis spp. can be induced to form colonies by adjusting biotic and abiotic factors in laboratory. Colony formation by cell division has been induced by zooplankton filtrate, high Pb 2+ concentration, the presence of another cyanobacterium (Cylindrospermopsis raciborskii), heterotrophic bacteria, and by low temperature and light intensity. Colony formation by cell adhesion can be induced by zooplankton grazing, high Ca 2+ concentration, and microcystins. We hypothesise that single cells of all Microcystis morphospecies initially form colonies with a similar morphology to those found in the early spring. These colonies gradually change their morphology to that of M. ichthyoblabe, M. wesenbergii and M. aeruginosa with changing environmental conditions. Colony formation provides Microcystis with many ecological advantages, including adaption to varying light, sustained growth under poor nutrient supply, protection from chemical stressors and protection from grazing. These benefits represent passive tactics responding to environmental stress. Microcystis colonies form at the cost of decreased specific growth rates compared with a unicellular habit. Large colony size allows Microcystis to attain rapid floating velocities (maximum recorded for a single colony, ∼ 10.08 m h -1 ) that enable them to develop and maintain a large biomass near the surface of eutrophic lakes, where they may shade

  20. Phosphate transport and arsenate resistance in the cyanobacterium Anabaena variabilis.

    OpenAIRE

    Thiel, T

    1988-01-01

    Cells of the cyanobacterium Anabaena variabilis starved for phosphate for 3 days took up phosphate at about 100 times the rate of unstarved cells. Kinetic data suggested that a new transport system had been induced by starvation for phosphate. The inducible phosphate transport system was quickly repressed by addition of Pi. Phosphate-starved cells were more sensitive to the toxic effects of arsenate than were unstarved cells, but phosphate could alleviate some of the toxicity. Arsenate was a ...

  1. Production of cyanophycin in Rhizopus oryzae through the expression of a cyanophycin synthetase encoding gene.

    Science.gov (United States)

    Meussen, Bas J; Weusthuis, Ruud A; Sanders, Johan P M; Graaff, Leo H de

    2012-02-01

    Cyanophycin or cyanophycin granule peptide is a protein that results from non-ribosomal protein synthesis in microorganisms such as cyanobacteria. The amino acids in cyanophycin can be used as a feedstock in the production of a wide range of chemicals such as acrylonitrile, polyacrylic acid, 1,4-butanediamine, and urea. In this study, an auxotrophic mutant (Rhizopus oryzae M16) of the filamentous fungus R. oryzae 99-880 was selected to express cyanophycin synthetase encoding genes. These genes originated from Synechocystis sp. strain PCC6803, Anabaena sp. strain PCC7120, and a codon optimized version of latter gene. The genes were under control of the pyruvate decarboxylase promoter and terminator elements of R. oryzae. Transformants were generated by the biolistic transformation method. In only two transformants both expressing the cyanophycin synthetase encoding gene from Synechocystis sp. strain PCC6803 was a specific enzyme activity detected of 1.5 mU/mg protein. In one of these transformants was both water-soluble and insoluble cyanophycin detected. The water-soluble fraction formed the major fraction and accounted for 0.5% of the dry weight. The water-insoluble CGP was produced in trace amounts. The amino acid composition of the water-soluble form was determined and constitutes of equimolar amounts of arginine and aspartic acid.

  2. Effects of cyanobacteria Synechocystis spp. in the host-parasite model Crassostrea gasar–Perkinsus marinus

    Energy Technology Data Exchange (ETDEWEB)

    Queiroga, Fernando Ramos [Laboratório de Imunologia e Patologia de Invertebrados (LABIPI), Departamento de Biologia Molecular, Universidade Federal da Paraíba, 58051-900, João Pessoa, Paraíba (Brazil); Marques-Santos, Luis Fernando [Laboratório de Biologia Celular e do Desenvolvimento (LABID), Departamento de Biologia Molecular, Universidade Federal da Paraíba, 58051-900, João Pessoa, Paraíba (Brazil); Hégaret, Hélène [Laboratoire des Sciences de l' Environnement Marin (LEMAR), UMR 6539 CNRS UBO IRD IFREMER, Institut Universitaire Européen de la Mer, Technopôle Brest-Iroise, 29280, Plouzané (France); Sassi, Roberto [Laboratório de Ambientes Recifais e Biotecnologia de Microalgas (LARBIM), Departamento de Sistemática e Ecologia, Universidade Federal da Paraíba, 58051-900, João Pessoa, Paraíba (Brazil); Farias, Natanael Dantas; Santana, Lucas Nunes [Laboratório de Imunologia e Patologia de Invertebrados (LABIPI), Departamento de Biologia Molecular, Universidade Federal da Paraíba, 58051-900, João Pessoa, Paraíba (Brazil); and others

    2017-06-15

    Highlights: • Synechocystis cyanobacteria cause functional weakness of oysters haemocytes. • Synechocystis cyanobacteria cause a strengthening of Perkinsus marinus. • Synechocystis cyanobacteria may contribute to an imbalance of P. marinus–Crassostrea gasar relationship. - Abstract: Perkinsosis is a disease caused by protozoan parasites from the Perkinsus genus. In Brazil, two species, P. beihaiensis and P. marinus, are frequently found infecting native oysters (Crassostrea gasar and C. rhizophorae) from cultured and wild populations in several states of the Northeast region. The impacts of this disease in bivalves from Brazil, as well as the interactions with environmental factors, are poorly studied. In the present work, we evaluated the in vitro effects of the cyanobacteria Synechocystis spp. on trophozoites of P. marinus and haemocytes of C. gasar. Four cyanobacteria strains isolated from the Northeast Brazilian coast were used as whole cultures (WCs) and extracellular products (ECPs). Trophozoites of P. marinus were exposed for short (4 h) and long (48 h and 7 days, the latter only for ECPs) periods, while haemocytes were exposed for a short period (4 h). Cellular and immune parameters, i.e. cell viability, cell count, reactive oxygen species production (ROS) and phagocytosis of inert (latex beads) and biological particles (zymosan and trophozoites of P. marinus) were measured by flow cytometry. The viability of P. marinus trophozoites was improved in response to WCs of Synechocystis spp., which could be a beneficial effect of the cyanobacteria providing nutrients and reducing reactive oxygen species. Long-term exposure of trophozoites to ECPs of cyanobacteria did not modify in vitro cell proliferation nor viability. In contrast, C. gasar haemocytes showed a reduction in cell viability when exposed to WCs, but not to ECPs. However, ROS production was not altered. Haemocyte ability to engulf latex particles was reduced when exposed mainly to ECPs of

  3. Effects of cyanobacteria Synechocystis spp. in the host-parasite model Crassostrea gasar–Perkinsus marinus

    International Nuclear Information System (INIS)

    Queiroga, Fernando Ramos; Marques-Santos, Luis Fernando; Hégaret, Hélène; Sassi, Roberto; Farias, Natanael Dantas; Santana, Lucas Nunes

    2017-01-01

    Highlights: • Synechocystis cyanobacteria cause functional weakness of oysters haemocytes. • Synechocystis cyanobacteria cause a strengthening of Perkinsus marinus. • Synechocystis cyanobacteria may contribute to an imbalance of P. marinus–Crassostrea gasar relationship. - Abstract: Perkinsosis is a disease caused by protozoan parasites from the Perkinsus genus. In Brazil, two species, P. beihaiensis and P. marinus, are frequently found infecting native oysters (Crassostrea gasar and C. rhizophorae) from cultured and wild populations in several states of the Northeast region. The impacts of this disease in bivalves from Brazil, as well as the interactions with environmental factors, are poorly studied. In the present work, we evaluated the in vitro effects of the cyanobacteria Synechocystis spp. on trophozoites of P. marinus and haemocytes of C. gasar. Four cyanobacteria strains isolated from the Northeast Brazilian coast were used as whole cultures (WCs) and extracellular products (ECPs). Trophozoites of P. marinus were exposed for short (4 h) and long (48 h and 7 days, the latter only for ECPs) periods, while haemocytes were exposed for a short period (4 h). Cellular and immune parameters, i.e. cell viability, cell count, reactive oxygen species production (ROS) and phagocytosis of inert (latex beads) and biological particles (zymosan and trophozoites of P. marinus) were measured by flow cytometry. The viability of P. marinus trophozoites was improved in response to WCs of Synechocystis spp., which could be a beneficial effect of the cyanobacteria providing nutrients and reducing reactive oxygen species. Long-term exposure of trophozoites to ECPs of cyanobacteria did not modify in vitro cell proliferation nor viability. In contrast, C. gasar haemocytes showed a reduction in cell viability when exposed to WCs, but not to ECPs. However, ROS production was not altered. Haemocyte ability to engulf latex particles was reduced when exposed mainly to ECPs of

  4. Unraveling the mechanism responsible for the contrasting tolerance of Synechocystis and Synechococcus to Cr(VI): Enzymatic and non-enzymatic antioxidants

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Alka [Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Ballal, Anand, E-mail: aballal@barc.gov.in [Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 40085 (India)

    2015-07-15

    Highlights: • Cr(VI) accumulation generates higher ROS in Synechocystis than in Synechococcus. • Synechococcus exhibits better photosynthetic activity in response to Cr(VI). • Synechococcus has higher enzymatic/non-enzymatic antioxidants than Synechocystis. • Synechococcus shows better tolerance to other oxidative stresses than Synechocystis. • Differential detoxification of ROS is responsible for the contrasting tolerance to Cr(VI) - Abstract: Two unicellular cyanobacteria, Synechocystis and Synechococcus, showed contrasting tolerance to Cr(VI); with Synechococcus being 12-fold more tolerant than Synechocystis to potassium dichromate. The mechanism responsible for this differential sensitivity to Cr(VI) was explored in this study. Total content of photosynthetic pigments as well as photosynthetic activity decreased at lower concentration of Cr(VI) in Synechocystis as compared to Synechococcus. Experiments with {sup 51}Cr showed Cr to accumulate intracellularly in both the cyanobacteria. At lower concentrations, Cr(VI) caused excessive ROS generation in Synechocystis as compared to that observed in Synechococcus. Intrinsic levels of enzymatic antioxidants, i.e., superoxide dismutase, catalase and 2-Cys-peroxiredoxin were considerably higher in Synechococcus than Synechocystis. Content of total thiols (both protein as well as non-protein) and reduced glutathione (GSH) was also higher in Synechococcus as compared to Synechocystis. This correlated well with higher content of carbonylated proteins observed in Synechocystis than Synechococcus. Additionally, in contrast to Synechocystis, Synechococcus exhibited better tolerance to other oxidative stresses like high intensity light and H{sub 2}O{sub 2}. The data indicate that the disparity in the ability to detoxify ROS could be the primary mechanism responsible for the differential tolerance of these cyanobacteria to Cr(VI)

  5. Three New Malyngamides from the Marine Cyanobacterium Moorea producens

    Directory of Open Access Journals (Sweden)

    Kosuke Sueyoshi

    2017-11-01

    Full Text Available Three new compounds of the malyngamide series, 6,8-di-O-acetylmalyngamide 2 (1, 6-O-acetylmalyngamide 2 (2, and N-demethyl-isomalyngamide I (3, were isolated from the marine cyanobacterium Moorea producens. Their structures were determined by spectroscopic analysis and chemical derivatization and degradation. These compounds stimulated glucose uptake in cultured L6 myotubes. In particular, 6,8-di-O-acetylmalyngamide 2 (1 showed potent activity and activated adenosine monophosphate-activated protein kinase (AMPK.

  6. Sodium-coupled motility in a swimming cyanobacterium.

    OpenAIRE

    Willey, J M; Waterbury, J B; Greenberg, E P

    1987-01-01

    The energetics of motility in Synechococcus strain WH8113 were studied to understand the unique nonflagellar swimming of this cyanobacterium. There was a specific sodium requirement for motility such that cells were immotile below 10 mM external sodium and cell speed increased with increasing sodium levels above 10 mM to a maximum of about 15 microns/s at 150 to 250 mM sodium. The sodium motive force increased similarly with increasing external sodium from -120 to -165 mV, but other energetic...

  7. Thermodynamic analysis of computed pathways integrated into the metabolic networks of E. coli and Synechocystis reveals contrasting expansion potential.

    Science.gov (United States)

    Asplund-Samuelsson, Johannes; Janasch, Markus; Hudson, Elton P

    2018-01-01

    Introducing biosynthetic pathways into an organism is both reliant on and challenged by endogenous biochemistry. Here we compared the expansion potential of the metabolic network in the photoautotroph Synechocystis with that of the heterotroph E. coli using the novel workflow POPPY (Prospecting Optimal Pathways with PYthon). First, E. coli and Synechocystis metabolomic and fluxomic data were combined with metabolic models to identify thermodynamic constraints on metabolite concentrations (NET analysis). Then, thousands of automatically constructed pathways were placed within each network and subjected to a network-embedded variant of the max-min driving force analysis (NEM). We found that the networks had different capabilities for imparting thermodynamic driving forces toward certain compounds. Key metabolites were constrained differently in Synechocystis due to opposing flux directions in glycolysis and carbon fixation, the forked tri-carboxylic acid cycle, and photorespiration. Furthermore, the lysine biosynthesis pathway in Synechocystis was identified as thermodynamically constrained, impacting both endogenous and heterologous reactions through low 2-oxoglutarate levels. Our study also identified important yet poorly covered areas in existing metabolomics data and provides a reference for future thermodynamics-based engineering in Synechocystis and beyond. The POPPY methodology represents a step in making optimal pathway-host matches, which is likely to become important as the practical range of host organisms is diversified. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  8. Enhancement of pyrene degradation efficacy of Synechocystis sp., by construction of an artificial microalgal-bacterial consortium

    Directory of Open Access Journals (Sweden)

    Jignasa G. Patel

    2015-12-01

    Full Text Available This study was carried out to investigate the ability of microalgae Synechocystis sp. to high molecular weight Polycyclic Aromatic Hydrocarbon pyrene (PYR and artificial microalgal–bacterial consortium at different concentrations. The consortium consisted of one axenic species Synechocystis sp. and two PYR-degrading bacteria with known complementary degradative capabilities viz. Pseudomonas sp. and Bacillus sp. The influence of PYR on growth in terms of chlorophyll-a were analysed, and it was found that in the presence of bacteria, Synechocystis sp. tremendously increased in growth as well as biodegradation capability, whereas Synechocystis sp. alone exhibited concentration-dependent decrease in growth and biodegradation ability. Degradation of PYR shows that the consortium could eliminate PYR by 94.1% at 50 mg/L; however, Synechocystis sp alone could degrade up to 36% at 1.5 mg/L after 16 days of incubation. The study revealed that microalgae grew better in the presence of the aerobic heterotrophic bacteria and provided them with necessary organics for efficient PYR degradation activities. Moreover, consortium JP-NKA7B2 grows efficiently on other xenobiotic compounds. The artificial consortia JP-NK is thus proven to be an effective and promising system for bioremediating PYR compound and could be suggested in degradation of PYR compound in hydrocarbon-polluted areas in situ and ex situ.

  9. Cyanobacterium sp. host cell and vector for production of chemical compounds in Cyanobacterial cultures

    Energy Technology Data Exchange (ETDEWEB)

    Piven, Irina; Friedrich, Alexandra; Duhring, Ulf; Uliczka, Frank; Baier, Kerstin; Inaba, Masami; Shi, Tuo; Wang, Kui; Enke, Heike; Kramer, Dan

    2016-04-19

    A cyanobacterial host cell, Cyanobacterium sp., that harbors at least one recombinant gene for the production of a chemical compounds is provided, as well as vectors derived from an endogenous plasmid isolated from the cell.

  10. Lipid production in association of filamentous fungi with genetically modified cyanobacterial cells.

    Science.gov (United States)

    Miranda, Ana F; Taha, Mohamed; Wrede, Digby; Morrison, Paul; Ball, Andrew S; Stevenson, Trevor; Mouradov, Aidyn

    2015-01-01

    Numerous strategies have evolved recently for the generation of genetically modified or synthetic microalgae and cyanobacteria designed for production of ethanol, biodiesel and other fuels. In spite of their obvious attractiveness there are still a number of challenges that can affect their economic viability: the high costs associated with (1) harvesting, which can account for up to 50 % of the total biofuel's cost, (2) nutrients supply and (3) oil extraction. Fungal-assisted bio-flocculation of microalgae is gaining increasing attention due to its high efficiency, no need for added chemicals and low energy inputs. The implementation of renewable alternative carbon, nitrogen and phosphorus sources from agricultural wastes and wastewaters for growing algae and fungi makes this strategy economically attractive. This work demonstrates that the filamentous fungi, Aspergillus fumigatus can efficiently flocculate the unicellular cyanobacteria Synechocystis PCC 6803 and its genetically modified derivatives that have been altered to enable secretion of free fatty acids into growth media. Secreted free fatty acids are potentially used by fungal cells as a carbon source for growth and ex-novo production of lipids. For most of genetically modified strains the total lipid yields extracted from the fungal-cyanobacterial pellets were found to be higher than additive yields of lipids and total free fatty acids produced by fungal and Synechocystis components when grown in mono-cultures. The synergistic effect observed in fungal-Synechocystis associations was also found in bioremediation rates when animal husbandry wastewater was used an alternative source of nitrogen and phosphorus. Fungal assisted flocculation can complement and assist in large scale biofuel production from wild-type and genetically modified Synechocystis PCC 6803 strains by (1) efficient harvesting of cyanobacterial cells and (2) producing of high yields of lipids accumulated in fungal-cyanobacterial pellets.

  11. New Cerebroside and Nucleoside Derivatives from a Red Sea Strain of the Marine Cyanobacterium Moorea producens

    OpenAIRE

    Diaa T.A. Youssef; Sabrin R.M. Ibrahim; Lamiaa A. Shaala; Gamal A. Mohamed; Zainy M. Banjar

    2016-01-01

    In the course of our ongoing efforts to identify marine-derived bioactive compounds, the marine cyanobacterium Moorea producens was investigated. The organic extract of the Red Sea cyanobacterium afforded one new cerebroside, mooreaside A (1), two new nucleoside derivatives, 3-acetyl-2′-deoxyuridine (2) and 3-phenylethyl-2′-deoxyuridine (3), along with the previously reported compounds thymidine (4) and 2,3-dihydroxypropyl heptacosanoate (5). The structures of the compounds were determined by...

  12. Structure of plastocyanin from the cyanobacterium Anabaena variabilis

    DEFF Research Database (Denmark)

    Schmidt, Lars; Christensen, Hans Erik Mølager; Harris, Pernille

    2006-01-01

    Plastocyanin from the cyanobacterium Anabaena variabilis was heterologously produced in E. coli and purified. Plate-like crystals were obtained by crystallisation in 1.15 M trisodium citrate and 7.67 mM sodium borate buffer pH 8.5. The crystals belong to the orthorhombic space group P212121...... with cell dimensions a = 67.85 Å, b = 45.81 Å and c = 63.41 Å. The structure of the oxidised protein was solved to a resolution of 1.6 Å using plastocyanin from Phormidium laminosum as search model. Two molecules were found in the asymmetric unit. The electrostatic surface of the basic protein showed...

  13. Ultraviolet radiation effects on pigmentation in the cyanobacterium ''Phormidium uncinatum''

    International Nuclear Information System (INIS)

    Donkor, V.A.; Haeder, D.P.

    1997-01-01

    The Baikal strain of the cyanobacterium Phormidium uncinatum was found to possess the photosynthetic pigments chlorophyll a, carotenoids, phycocyanin and allophycocyanin, while the Tuebingen strain of Phormidium contained, in addition to these, the biliprotein phycoerythrin. Sucrose gradient centrifugation of the pigment extracts resulted in a separation of the phycobiliproteins into several bands, which according to their absorption and fluorescence properties, were identified as monomers, trimers and hexamers. With increasing UV-B irradiation the heavier aggregates were broken down into smaller components. Photobleaching of these accessory pigments also occurred. FPLC gel filtration analyses of the pigments also showed loss of heavier aggregates of the phycobilins and bleaching of the pigments. SDS-polyacrylamide gel electrophoresis of the sucrose gradient and FPLC fractions indicated loss of the biliproteins with increasing UV-B irradiation. The loss of the β- were more rapid than that of the α- subunits. Increasing levels of ultraviolet irradiation is therefore deleterious to these organism. (author)

  14. Zn2+-Inducible Expression Platform for Synechococcus sp. Strain PCC 7002 Based on the smtA Promoter/Operator and smtB Repressor.

    Science.gov (United States)

    Pérez, Adam A; Gajewski, John P; Ferlez, Bryan H; Ludwig, Marcus; Baker, Carol S; Golbeck, John H; Bryant, Donald A

    2017-02-01

    Synechococcus sp. strain PCC 7002 has been gaining significance as both a model system for photosynthesis research and for industrial applications. Until recently, the genetic toolbox for this model cyanobacterium was rather limited and relied primarily on tools that only allowed constitutive gene expression. This work describes a two-plasmid, Zn 2+ -inducible expression platform that is coupled with a zurA mutation, providing enhanced Zn 2+ uptake. The control elements are based on the metal homeostasis system of a class II metallothionein gene (smtA 7942 ) and its cognate SmtB 7942 repressor from Synechococcus elongatus strain PCC 7942. Under optimal induction conditions, yellow fluorescent protein (YFP) levels were about half of those obtained with the strong, constitutive phycocyanin (cpcBA 6803 ) promoter of Synechocystis sp. strain PCC 6803. This metal-inducible expression system in Synechococcus sp. strain PCC 7002 allowed the titratable gene expression of YFP that was up to 19-fold greater than the background level. This system was utilized successfully to control the expression of the Drosophila melanogaster β-carotene 15,15'-dioxygenase, NinaB, which is toxic when constitutively expressed from a strong promoter in Synechococcus sp. strain PCC 7002. Together, these properties establish this metal-inducible system as an additional useful tool that is capable of controlling gene expression for applications ranging from basic research to synthetic biology in Synechococcus sp. strain PCC 7002. This is the first metal-responsive expression system in cyanobacteria, to our knowledge, that does not exhibit low sensitivity for induction, which is one of the major hurdles for utilizing this class of genetic tools. In addition, high levels of expression can be generated that approximate those of established constitutive systems, with the added advantage of titratable control. Together, these properties establish this Zn 2+ -inducible system, which is based on the

  15. Consequences of Modification of Photosystem Stoichiometry and Amount in Cyanobacteria

    Energy Technology Data Exchange (ETDEWEB)

    Vermaas, Willem [Arizona State Univ., Tempe, AZ (United States)

    2016-12-13

    The proposed research seeks to address two interconnected, important questions that impact photosynthetic processes and that reflect key differences between the photosynthetic systems of cyanobacteria and plants or algae. The first question is what are the reasons and consequences of the high photosystem I / photosystem II (PS I/PS II) ratio in many cyanobacteria, vs. a ratio that is close to unity in many plants and algae. The corresponding hypothesis is that most of PS I functions in cyclic electron transport, and that reduction in PS I will result primarily in a shortage of ATP rather than reducing power. This hypothesis will be tested by reducing the amount of PS I by changing the promoter region of the psaAB operon in the cyanobacterium Synechocystis sp. PCC 6803 and generating a range of mutants with different PS I content and thereby different PS I/PS II ratios, with some of the mutants having a PS II/PS I ratio closer to that in plants. The resulting mutants will be probed in terms of their growth rates, electron transfer rates, and P700 redox kinetics. A second question relates to a Mehler-type reaction catalyzed by two flavoproteins, Flv1 and Flv3, that accept electrons from PS I and that potentially function as an electron safety valve leading to no useful purpose of the photosynthesis-generated electrons. The hypothesis to be tested is that Flv1 and Flv3 use the electrons for useful purposes such as cyclic electron flow around PS I. This hypothesis will be tested by analysis of a mutant strain lacking flv3, the gene for one of the flavoproteins. This research is important for a more detailed understanding of the consequences of photosystem stoichiometry and amounts in a living system. Such an understanding is critical for not only insights in the regulatory systems of the organism but also to guide the development of biological or bio-hybrid systems for solar energy conversion into fuels.

  16. Single particle analysis of thylakoid proteins from Thermosynechococcus elongatus and Synechocystis 6803 : Localization of the CupA subunit of NDH-1

    NARCIS (Netherlands)

    Folea, I. Mihaela; Zhang, Pengpeng; Nowaczyk, Marc M.; Ogawa, Teruo; Aro, Eva-Marl; Boekema, Egbert J.; Aro, Eva-Mari

    The larger protein complexes of the cyanobacterial photosynthetic membrane of Thermosynechoccus elongatus and Synechocystis 6803 were studied by single particle electron microscopy after detergent solubilization, without any purification steps. Besides the "standard" L-shaped NDH-1L complex, related

  17. Computational analysis of LexA regulons in Cyanobacteria

    Directory of Open Access Journals (Sweden)

    Su Zhengchang

    2010-09-01

    Full Text Available Abstract Background The transcription factor LexA plays an important role in the SOS response in Escherichia coli and many other bacterial species studied. Although the lexA gene is encoded in almost every bacterial group with a wide range of evolutionary distances, its precise functions in each group/species are largely unknown. More recently, it has been shown that lexA genes in two cyanobacterial genomes Nostoc sp. PCC 7120 and Synechocystis sp. PCC 6803 might have distinct functions other than the regulation of the SOS response. To gain a general understanding of the functions of LexA and its evolution in cyanobacteria, we conducted the current study. Results Our analysis indicates that six of 33 sequenced cyanobacterial genomes do not harbor a lexA gene although they all encode the key SOS response genes, suggesting that LexA is not an indispensable transcription factor in these cyanobacteria, and that their SOS responses might be regulated by different mechanisms. Our phylogenetic analysis suggests that lexA was lost during the course of evolution in these six cyanobacterial genomes. For the 26 cyanobacterial genomes that encode a lexA gene, we have predicted their LexA-binding sites and regulons using an efficient binding site/regulon prediction algorithm that we developed previously. Our results show that LexA in most of these 26 genomes might still function as the transcriptional regulator of the SOS response genes as seen in E. coli and other organisms. Interestingly, putative LexA-binding sites were also found in some genomes for some key genes involved in a variety of other biological processes including photosynthesis, drug resistance, etc., suggesting that there is crosstalk between the SOS response and these biological processes. In particular, LexA in both Synechocystis sp. PCC6803 and Gloeobacter violaceus PCC7421 has largely diverged from those in other cyanobacteria in the sequence level. It is likely that LexA is no longer a

  18. Sucrose secreted by the engineered cyanobacterium and its fermentability

    Science.gov (United States)

    Duan, Yangkai; Luo, Quan; Liang, Feiyan; Lu, Xuefeng

    2016-10-01

    The unicellular cyanobacterium, Synechococcus elongatus PCC 7942 (Syn7942), synthesizes sucrose as the only compatible solute under salt stress. A series of engineered Syn7942 strains for sucrose production were constructed. The overexpression of the native sps (encoding a natively fused protein of sucrose phosphate synthase SPS and sucrose phosphate phosphatase SPP) in Syn7942 wild type caused a 93% improvement of sucrose productivity. The strain FL130 co-overexpressing sps and cscB (encoding a sucrose transporter) exhibited a 74% higher extracellular sucrose production than that overexpressing cscB only. Both results showed the significant improvement of sucrose productivity by the double functional protein SPS-SPP. Afterwards, FL130 was cultivated under a modified condition, and the cell-free culture medium containing 1.5 g L-1 sucrose was pre-treated with an acid hydrolysis technique. Cultivated with the neutralized hydrolysates as the starting media, two widely used microorganisms, Escherichia coli and Saccharomyces cerevisiae, showed a comparable growth with that in the control media supplemented with glucose. These results clearly demonstrated that the cell-free culture of sucrose-secreting cyanobacteria can be applied as starting media in microbial cultivation.

  19. Biolubricant potential of exopolysaccharides from the cyanobacterium Cyanothece epiphytica.

    Science.gov (United States)

    Borah, Dharitri; Nainamalai, Sangeetha; Gopalakrishnan, Subramanian; Rout, Jayashree; Alharbi, Naiyf S; Alharbi, Sulaiman Ali; Nooruddin, Thajuddin

    2018-04-01

    Exopolysaccaharides (EPS) are carbohydrate polymers secreted by microbial cells, as a protective layer termed sheath or capsule. Their composition is variable. Optimisation of nutrient factors and the effect of some simple stresses on the ability of Cyanothece epiphytica to produce EPS were tested. Of the tested stresses, exposure to ozone for 50 s at 0.06 mg/L resulted in a relatively high EPS yield, without any damage to cell structure. EPS was characterised physicochemically. Chemically, it was found to be composed of pentoses arabinose and xylose; hexoses glucose, galactose and mannose; and the deoxyhexose fucose sugars which were sulphated and with different functional groups. EPS from C. epiphytica was found to be a good hydrophobic dispersant, an excellent emulsifier as well as a flocculant. Its potential as a biolubricant with characteristics better than the conventional lubricant 'grease' was revealed through analysis. This study gave the clue for developing a commercial technology to produce a less expensive and more environment-friendly natural lubricant from the cyanobacterium C. epiphytica for tribological applications.

  20. Nitrogen-fixing cyanobacterium with a high phycoerythrin content.

    Science.gov (United States)

    Rodriguez, H; Rivas, J; Guerrero, M G; Losada, M

    1989-03-01

    The elemental and molecular composition, pigment content, and productivity of a phycoerythrin-rich nitrogen-fixing cyanobacterium-an Anabaena strain isolated from the coastal lagoon Albufera de Valencia, Spain-has been investigated. When compared with other heterocystous species, this strain exhibits similar chlorophyll a, carotene, and total phycobiliprotein contents but differs remarkably in the relative proportion of specific phycobiliproteins; the content of C-phycoerythrin amounts to 8.3% (versus about 1% in the other species) of cell dry weight. Absorption and fluorescence spectra of intact phycobilisomes isolated from this Anabaena sp. corroborate the marked contribution of phycoerythrin as an antenna pigment, a circumstance that is unusual for cyanobacteria capable of fixing N(2). The pigment content of cells is affected by variations in irradiance and cell density, these adaptive changes being more patent for C-phycoerythrin than for phycocyanins. The Anabaena strain is clumpy and capable of rapid flocculation. It exhibits outdoor productivities higher than 20 g (dry weight) m day during summer.

  1. Ribulose diphosphate carboxylase of the cyanobacterium Spirulina platensis

    Energy Technology Data Exchange (ETDEWEB)

    Terekhova, I.V.; Chernyad' ev, I.I.; Doman, N.G.

    1986-11-20

    The ribulose diphosphate (RDP) carboxylase activity of the cyanobacterium Spirulina platensis is represented by two peaks when a cell homogenate is centrifuged in a sucrose density gradient. In the case of differential centrifugation (40,000 g, 1 h), the activity of the enzyme was distributed between the supernatant liquid (soluble form) and the precipitate (carboxysomal form). From the soluble fraction, in which 80-95% of the total activity of the enzyme is concentrated, electrophoretically homogeneous RDP carboxylase was isolated by precipitation with ammonium sulfate and centrifugation in a sucrose density gradient. The purified enzyme possessed greater electrophoretic mobility in comparison with the RDP carboxylase of beans Vicia faba. The molecular weight of the enzyme, determined by gel filtration, was 450,000. The enzyme consists of monotypic subunits with a molecular weight of 53,000. The small subunits were not detected in electrophoresis in polyacrylamide gel in the presence of SDS after fixation and staining of the gels by various methods.

  2. Binding characteristics of copper and cadmium by cyanobacterium Spirulina platensis

    Energy Technology Data Exchange (ETDEWEB)

    Fang Linchuan [State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070 (China); Zhou Chen; Cai Peng [Key Laboratory of Subtropical Agricultural Resources and Environment, Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070 (China); Chen Wenli [State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070 (China); Rong Xingmin; Dai Ke; Liang Wei [Key Laboratory of Subtropical Agricultural Resources and Environment, Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070 (China); Gu Jidong [Department of Ecology and Biodiversity, University of Hong Kong, Pokfulam Road, Hong Kong (Hong Kong); Huang Qiaoyun, E-mail: qyhuang@mail.hzau.edu.cn [State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070 (China); Key Laboratory of Subtropical Agricultural Resources and Environment, Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070 (China)

    2011-06-15

    Highlights: {yields} The carboxyl groups play a vital role in the binding of Cu(II) and Cd(II) to S. platensis cells. {yields} Ion exchange and complexation are the dominating mechanism for Cu(II) and Cd(II) adsorption. {yields} XAFS analysis provided evidence for the inner-sphere complexation of Cu by carboxyl ligands and showed that Cu is complexed by two 5-membered chelate rings on S. platensis surface. - Abstract: Cyanobacteria are promising biosorbent for heavy metals in bioremediation. Although sequestration of metals by cyanobacteria is known, the actual mechanisms and ligands involved are not very well understood. The binding characteristics of Cu(II) and Cd(II) by the cyanobacterium Spirulina platensis were investigated using a combination of chemical modifications, batch adsorption experiments, Fourier transform infrared (FTIR) spectroscopy and X-ray absorption fine structure (XAFS) spectroscopy. A significant increase in Cu(II) and Cd(II) binding was observed in the range of pH 3.5-5.0. Dramatical decrease in adsorption of Cu(II) and Cd(II) was observed after methanol esterification of the nonliving cells demonstrating that carboxyl functional groups play an important role in the binding of metals by S. platensis. The desorption rate of Cu(II) and Cd(II) from S. platensis surface was 72.7-80.7% and 53.7-58.0% by EDTA and NH{sub 4}NO{sub 3}, respectively, indicating that ion exchange and complexation are the dominating mechanisms for Cu(II) and Cd(II) adsorption. XAFS analysis provided further evidence on the inner-sphere complexation of Cu by carboxyl ligands and showed that Cu is complexed by two 5-membered chelate rings on S. platensis surface.

  3. Antagonistic interactions between filamentous heterotrophs and the cyanobacterium Nostoc muscorum

    Directory of Open Access Journals (Sweden)

    Wolf Sarah

    2011-09-01

    Full Text Available Abstract Background Little is known about interactions between filamentous heterotrophs and filamentous cyanobacteria. Here, interactions between the filamentous heterotrophic bacteria Fibrella aestuarina (strain BUZ 2 and Fibrisoma limi (BUZ 3 with an axenic strain of the autotrophic filamentous cyanobacterium Nostoc muscorum (SAG 25.82 were studied in mixed cultures under nutrient rich (carbon source present in medium and poor (carbon source absent in medium conditions. Findings F. aestuarina BUZ 2 significantly reduced the cyanobacterial population whereas F. limi BUZ 3 did not. Physical contact between heterotrophs and autotroph was observed and the cyanobacterial cells showed some level of damage and lysis. Therefore, either contact lysis or entrapment with production of extracellular compounds in close vicinity of host cells could be considered as potential modes of action. The supernatants from pure heterotrophic cultures did not have an effect on Nostoc cultures. However, supernatant from mixed cultures of BUZ 2 and Nostoc had a negative effect on cyanobacterial growth, indicating that the lytic compounds were only produced in the presence of Nostoc. The growth and survival of tested heterotrophs was enhanced by the presence of Nostoc or its metabolites, suggesting that the heterotrophs could utilize the autotrophs and its products as a nutrient source. However, the autotroph could withstand and out-compete the heterotrophs under nutrient poor conditions. Conclusions Our results suggest that the nutrients in cultivation media, which boost or reduce the number of heterotrophs, were the important factor influencing the outcome of the interplay between filamentous heterotrophs and autotrophs. For better understanding of these interactions, additional research is needed. In particular, it is necessary to elucidate the mode of action for lysis by heterotrophs, and the possible defense mechanisms of the autotrophs.

  4. Arsenic biotransformation by a cyanobacterium Nostoc sp. PCC 7120.

    Science.gov (United States)

    Xue, Xi-Mei; Yan, Yu; Xiong, Chan; Raber, Georg; Francesconi, Kevin; Pan, Ting; Ye, Jun; Zhu, Yong-Guan

    2017-09-01

    Nostoc sp. PCC 7120 (Nostoc), a typical filamentous cyanobacterium ubiquitous in aquatic system, is recognized as a model organism to study prokaryotic cell differentiation and nitrogen fixation. In this study, Nostoc cells incubated with arsenite (As(III)) for two weeks were extracted with dichloromethane/methanol (DCM/MeOH) and the extract was partitioned between water and DCM. Arsenic species in aqueous and DCM layers were determined using high performance liquid chromatography - inductively coupled plasma mass spectrometer/electrospray tandem mass spectrometry (HPLC-ICPMS/ESIMSMS). In addition to inorganic arsenic (iAs), the aqueous layer also contained monomethylarsonate (MAs(V)), dimethylarsinate (DMAs(V)), and the two arsenosugars, namely a glycerol arsenosugar (Oxo-Gly) and a phosphate arsenosugar (Oxo-PO4). Two major arsenosugar phospholipids (AsSugPL982 and AsSugPL984) were detected in DCM fraction. Arsenic in the growth medium was also investigated by HPLC/ICPMS and shown to be present mainly as the inorganic forms As(III) and As(V) accounting for 29%-38% and 29%-57% of the total arsenic respectively. The total arsenic of methylated arsenic, arsenosugars, and arsenosugar phospholipids in Nostoc cells with increasing As(III) exposure were not markedly different, indicating that the transformation to organoarsenic in Nostoc was not dependent on As(III) concentration in the medium. Our results provide new insights into the role of cyanobacteria in the biogeochemical cycling of arsenic. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Sterol Compositions of the Filamentous Nitrogen-Fixing Terrestrial Cyanobacterium Scytonema sp

    Czech Academy of Sciences Publication Activity Database

    Řezanka, Tomáš; Dembitsky, V. M.; Go, J. V.; Dor, I.; Prell, Aleš; Hanuš, L.

    2003-01-01

    Roč. 48, č. 3 (2003), s. 357-360 ISSN 0015-5632 Institutional research plan: CEZ:AV0Z5020903 Keywords : nitrogen-fixing * cyanobacterium * scytonema Subject RIV: EE - Microbiology, Virology Impact factor: 0.857, year: 2003

  6. A host-vector system for gene cloning in the cyanobacterium Anacystis nidulans R2

    NARCIS (Netherlands)

    Kuhlemeier, C. J.; Thomas, A. A.; van der Ende, A.; van Leen, R. W.; Borrias, W. E.; van den Hondel, C. A.; van Arkel, G. A.

    1983-01-01

    We describe the construction of a series of vectors suitable for gene cloning in the cyanobacterium Anacystis nidulans R2. From the indigenous plasmid pUH24, derivatives were constructed with streptomycin as the selective marker; one of these plasmids was used to construct pUC303, a shuttle vector

  7. Effect of Selected Plant Extracts and D- and L-Lysine on the Cyanobacterium Microcystis aeruginosa

    NARCIS (Netherlands)

    Lurling, M.; Van Oosterhout, F.

    2014-01-01

    We tested extracts from Fructus mume, Salvia miltiorrhiza and Moringa oleifera as well as L-lysine and D-Lysine as curative measures to rapidly suppress the cyanobacterium Microcystis aeruginosa NIVA-CYA 43. We tested these compounds under similar conditions to facilitate comparisons. We

  8. Horizontal transfer of the nitrogen fixation gene cluster in the cyanobacterium Microcoleus chthonoplastes

    NARCIS (Netherlands)

    Bolhuis, H.; Severin, I.; Confurius - Guns, Veronique; Wollenzien, U.I.A.; Stal, L.J.

    2010-01-01

    The filamentous, non-heterocystous cyanobacterium Microcoleus chthonoplastes is a cosmopolitan organism, known to build microbial mats in a variety of different environments. Although most of these cyanobacterial mats are known for their capacity to fix dinitrogen, M. chthonoplastes has not been

  9. Nostoc PCC7524, a cyanobacterium which contains five sequence-specific deoxyribonucleases

    NARCIS (Netherlands)

    Reaston, J.; Duybesteyn, M.G.C.; Waard, Adrian de

    1982-01-01

    Five nucleotide sequence-specific deoxyribonucleases present in cell-free extracts of the filamentous cyanobacterium Nostoc PCC7524 have been purified and characterized. One of these enzymes, designated Nsp(7524)I cleaves at a new kind of nucleotide sequence i.e. 5'-PuCATG λ Py-3'. The other four

  10. Competition between a prochlorophyte and a cyanobacterium under various phosphorus regimes : Comparison with the Droop model

    NARCIS (Netherlands)

    Ducobu, H; Jonker, RR; Mur, LR

    The ecophysiology and competitive behavior of the prochlorophyte Prochlorothrix hollandica Burger-Wiersma, Stal et Mur, and the cyanobacterium Planktothrix agardhii Anagn. et Kom. were investigated in phosphorus-limited continuous cultures. When the species we-re exposed to successive

  11. Competition and facilitation between the marine nitrogen-fixing cyanobacterium Cyanothece and its associated bacterial community

    NARCIS (Netherlands)

    Brauer, V.S.; Stomp, M.; Bouvier, T.; Fouilland, E.; Leboulanger, C.; Confurius-Guns, V.; Weissing, F.J.; Stal, L.J.; Huisman, J.

    2015-01-01

    N2-fixing cyanobacteria represent a major source of new nitrogen and carbon for marine microbial communities, but little is known about their ecological interactions with associated microbiota. In this study we investigated the interactions between the unicellular N2-fixing cyanobacterium Cyanothece

  12. Systematic cyanobacterial membrane proteome analysis by combining acid hydrolysis and digestive enzymes with nano-liquid chromatography-Fourier transform mass spectrometry.

    Science.gov (United States)

    Kwon, Joseph; Oh, Jeehyun; Park, Chiyoul; Cho, Kun; Kim, Seung Il; Kim, Soohyun; Lee, Sunghoon; Bhak, Jong; Norling, Birgitta; Choi, Jong-Soon

    2010-01-15

    The identification of membrane proteins is currently under-represented since the trans-membrane domains of membrane proteins have a hydrophobic property. Membrane proteins have mainly been analyzed by cleaving and identifying exposed hydrophilic domains. We developed the membrane proteomics method for targeting integral membrane proteins by the following sequential process: in-solution acid hydrolysis, reverse phase chromatographic separation, trypsin or chymotrypsin digestion and nano-liquid chromatography-Fourier transform mass spectrometry. When we employed total membrane proteins of Synechocystis sp. PCC 6803, 155 integral membrane proteins out of a predictable 706 were identified in a single application, corresponding to 22% of a genome. The combined methods of acid hydrolysis-trypsin (AT) and acid hydrolysis-chymotrypsin (AC) identified both hydrophilic and hydrophobic domains of integral membrane proteins, respectively. The systematic approach revealed a more concrete data in mapping the repertoire of cyanobacterial membrane and membrane-linked proteome. 2009 Elsevier B.V. All rights reserved.

  13. Tyrosinase-catalyzed site-specific immobilization of engineered C-phycocyanin to surface

    Science.gov (United States)

    Faccio, Greta; Kämpf, Michael M.; Piatti, Chiara; Thöny-Meyer, Linda; Richter, Michael

    2014-06-01

    Enzymatic crosslinking of proteins is often limited by the steric availability of the target residues, as of tyrosyl side chains in the case of tyrosinase. Carrying an N-terminal peptide-tag containing two tyrosine residues, the fluorescent protein C-phycocyanin HisCPC from Synechocystis sp. PCC6803 was crosslinked to fluorescent high-molecular weight forms with tyrosinase. Crosslinking with tyrosinase in the presence of L-tyrosine produced non fluorescent high-molecular weight products. Incubated in the presence of tyrosinase, HisCPC could also be immobilized to amino-modified polystyrene beads thus conferring a blue fluorescence. Crosslinking and immobilization were site-specific as both processes required the presence of the N-terminal peptide in HisCPC.

  14. Single-cell screening of photosynthetic growth and lactate production by cyanobacteria

    DEFF Research Database (Denmark)

    Hammar, Petter; Angermayr, S. Andreas; Sjostrom, Staffan L.

    2015-01-01

    Background: Photosynthetic cyanobacteria are attractive for a range of biotechnological applications including biofuel production. However, due to slow growth, screening of mutant libraries using microtiter plates is not feasible.Results: We present a method for high-throughput, single......-cell analysis and sorting of genetically engineered l-lactate-producing strains of Synechocystis sp. PCC6803. A microfluidic device is used to encapsulate single cells in picoliter droplets, assay the droplets for L-lactate production, and sort strains with high productivity. We demonstrate the separation...... of low- and high-producing reference strains, as well as enrichment of a more productive L-lactate-synthesizing population after UV-induced mutagenesis. The droplet platform also revealed population heterogeneity in photosynthetic growth and lactate production, as well as the presence of metabolically...

  15. Cyanobacteria as a Platform for the High-Value Chemicals Production

    DEFF Research Database (Denmark)

    Wlodarczyk, Artur Jacek

    Emerging problems like increasing global warming and depletion of fossil fuels bring serious concerns regarding production of food and various chemicals in the future. Clearly, there is a need for finding alternative and more sustainable ways of producing chemicals in order to satisfy increasing...... consumer demands of an ever growing population. Considering the ability to convert solar energy and carbon dioxide into biomass, cyanobacteria and microalgae have potential for becoming such alternative in the future. Biosynthesis of a great number of plant high-value secondary metabolites requires...... and cheap fertilizer as a medium for the cultivation of engineered cyanobacterial strains is shown. Alternative strategy to engineer Synechocystis sp. PCC 6803 as a universal platform for the sustainable production of diverse range high-value phenylpropanoids which find use as pharmaceuticals, cosmetics...

  16. Identification of the chlE gene encoding oxygen-independent Mg-protoporphyrin IX monomethyl ester cyclase in cyanobacteria.

    Science.gov (United States)

    Yamanashi, Kaori; Minamizaki, Kei; Fujita, Yuichi

    2015-08-07

    The fifth ring (E-ring) of chlorophyll (Chl) a is produced by Mg-protoporphyrin IX monomethyl ester (MPE) cyclase. There are two evolutionarily unrelated MPE cyclases: oxygen-independent (BchE) and oxygen-dependent (ChlA/AcsF) MPE cyclases. Although ChlA is the sole MPE cyclase in Synechocystis PCC 6803, it is yet unclear whether BchE exists in cyanobacteria. A BLAST search suggests that only few cyanobacteria possess bchE. Here, we report that two bchE candidate genes from Cyanothece strains PCC 7425 and PCC 7822 restore the photosynthetic growth and bacteriochlorophyll production in a bchE-lacking mutant of Rhodobacter capsulatus. We termed these cyanobacterial bchE orthologs "chlE." Copyright © 2015 Elsevier Inc. All rights reserved.

  17. An easy and efficient permeabilization protocol for in vivo enzyme activity assays in cyanobacteria

    DEFF Research Database (Denmark)

    Rasmussen, Randi Engelberth; Erstad, Simon Matthé; Ramos Martinez, Erick Miguel

    2016-01-01

    BACKGROUND: Cyanobacteria are photosynthetic bacteria that thrive in diverse ecosystems and play major roles in the global carbon cycle. The abilities of cyanobacteria to fix atmospheric CO2 and to allocate the fixed carbons to chemicals and biofuels have attracted growing attentions as sustainable...... microbial cell factories. Better understanding of the activities of enzymes involved in the central carbon metabolism would lead to increasing product yields. Currently cell-free lysates are the most widely used method for determination of intracellular enzyme activities. However, due to thick cell walls...... for permeabilization of the cyanobacteria Synechococcus sp. PCC 7002 and Synechocystis sp. PCC 6803, and determination of two intracellular enzymes, ribulose-1,5-bisphosphate carboxylase/decarboxylase (Rubisco) and glucose-6-phosphate dehydrogenase (G6PDH), that play pivotal roles in the central carbon metabolism...

  18. Structural Determinats Underlying Photoprotection in the Photoactive Orange Carotenoid Protein of Cyanobacteria

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Adjele; Kinney, James N.; Zwart, Petrus H.; Punginelli, Claire; D' Haene, Sandrine; Perreau, Francois; Klein, Michael G.; Kirilovsky, Diana; Kerfeld, Cheryl

    2010-04-01

    The photoprotective processes of photosynthetic organisms involve the dissipation of excess absorbed light energy as heat. Photoprotection in cyanobacteria is mechanistically distinct from that in plants; it involves the Orange Carotenoid Protein (OCP), a water-soluble protein containing a single carotenoid. The OCP is a new member of the family of blue light photoactive proteins; blue-green light triggers the OCP-mediated photoprotective response. Here we report structural and functional characterization of the wildtype and two mutant forms of the OCP, from the model organism Synechocystis PCC6803. The structural analysis provides highresolution detail of the carotenoidprotein interactions that underlie the optical properties of the OCP, unique among carotenoid-proteins in binding a single pigment per polypeptide chain. Collectively, these data implicate several key amino acids in the function of the OCP and reveal that the photoconversion and photoprotective responses of the OCP to blue-green light can be decoupled.

  19. Alkane Biosynthesis Genes in Cyanobacteria and Their Transcriptional Organization

    Energy Technology Data Exchange (ETDEWEB)

    Klähn, Stephan; Baumgartner, Desirée; Pfreundt, Ulrike; Voigt, Karsten; Schön, Verena; Steglich, Claudia; Hess, Wolfgang R., E-mail: wolfgang.hess@biologie.uni-freiburg.de [Genetics and Experimental Bioinformatics, Institute of Biology 3, Faculty of Biology, University of Freiburg, Freiburg (Germany)

    2014-07-14

    In cyanobacteria, alkanes are synthesized from a fatty acyl-ACP by two enzymes, acyl–acyl carrier protein reductase and aldehyde deformylating oxygenase. Despite the great interest in the exploitation for biofuel production, nothing is known about the transcriptional organization of their genes or the physiological function of alkane synthesis. The comparison of 115 microarray datasets indicates the relatively constitutive expression of aar and ado genes. The analysis of 181 available genomes showed that in 90% of the genomes both genes are present, likely indicating their physiological relevance. In 61% of them they cluster together with genes encoding acetyl-CoA carboxyl transferase and a short-chain dehydrogenase, strengthening the link to fatty acid metabolism and in 76% of the genomes they are located in tandem, suggesting constraints on the gene arrangement. However, contrary to the expectations for an operon, we found in Synechocystis sp. PCC 6803 specific promoters for the two genes, sll0208 (ado) and sll0209 (aar), which give rise to monocistronic transcripts. Moreover, the upstream located ado gene is driven by a proximal as well as a second, distal, promoter, from which a third transcript, the ~160 nt sRNA SyR9 is transcribed. Thus, the transcriptional organization of the alkane biosynthesis genes in Synechocystis sp. PCC 6803 is of substantial complexity. We verified all three promoters to function independently from each other and show a similar promoter arrangement also in the more distant Nodularia spumigena, Trichodesmium erythraeum, Anabaena sp. PCC 7120, Prochlorococcus MIT9313, and MED4. The presence of separate regulatory elements and the dominance of monocistronic mRNAs suggest the possible autonomous regulation of ado and aar. The complex transcriptional organization of the alkane synthesis gene cluster has possible metabolic implications and should be considered when manipulating the expression of these genes in cyanobacteria.

  20. Alkane Biosynthesis Genes in Cyanobacteria and Their Transcriptional Organization

    International Nuclear Information System (INIS)

    Klähn, Stephan; Baumgartner, Desirée; Pfreundt, Ulrike; Voigt, Karsten; Schön, Verena; Steglich, Claudia; Hess, Wolfgang R.

    2014-01-01

    In cyanobacteria, alkanes are synthesized from a fatty acyl-ACP by two enzymes, acyl–acyl carrier protein reductase and aldehyde deformylating oxygenase. Despite the great interest in the exploitation for biofuel production, nothing is known about the transcriptional organization of their genes or the physiological function of alkane synthesis. The comparison of 115 microarray datasets indicates the relatively constitutive expression of aar and ado genes. The analysis of 181 available genomes showed that in 90% of the genomes both genes are present, likely indicating their physiological relevance. In 61% of them they cluster together with genes encoding acetyl-CoA carboxyl transferase and a short-chain dehydrogenase, strengthening the link to fatty acid metabolism and in 76% of the genomes they are located in tandem, suggesting constraints on the gene arrangement. However, contrary to the expectations for an operon, we found in Synechocystis sp. PCC 6803 specific promoters for the two genes, sll0208 (ado) and sll0209 (aar), which give rise to monocistronic transcripts. Moreover, the upstream located ado gene is driven by a proximal as well as a second, distal, promoter, from which a third transcript, the ~160 nt sRNA SyR9 is transcribed. Thus, the transcriptional organization of the alkane biosynthesis genes in Synechocystis sp. PCC 6803 is of substantial complexity. We verified all three promoters to function independently from each other and show a similar promoter arrangement also in the more distant Nodularia spumigena, Trichodesmium erythraeum, Anabaena sp. PCC 7120, Prochlorococcus MIT9313, and MED4. The presence of separate regulatory elements and the dominance of monocistronic mRNAs suggest the possible autonomous regulation of ado and aar. The complex transcriptional organization of the alkane synthesis gene cluster has possible metabolic implications and should be considered when manipulating the expression of these genes in cyanobacteria.

  1. Alkane biosynthesis genes in cyanobacteria and their transcriptional organization

    Directory of Open Access Journals (Sweden)

    Stephan eKlähn

    2014-07-01

    Full Text Available In cyanobacteria, alkanes are synthesized from a fatty acyl-ACP by two enzymes, acyl-acyl carrier protein reductase (AAR and aldehyde deformylating oxygenase (ADO. Despite the great interest in the exploitation for biofuel production, nothing is known about the transcriptional organization of their genes or the physiological function of alkane synthesis. The comparison of 115 microarray datasets indicates the relatively constitutive expression of aar and ado genes. The analysis of 181 available genomes showed that in 90% of the genomes both genes are present, likely indicating their physiological relevance. In 61% of them they cluster together with genes encoding acetyl-CoA carboxyl transferase and a short chain dehydrogenase, strengthening the link to fatty acid metabolism and in 76% of the genomes they are located in tandem, suggesting constraints on the gene arrangement. However, contrary to the expectations for an operon, we found in Synechocystis sp. PCC 6803 specific promoters for the two genes, sll0208 (ado and sll0209 (aar, that give rise to monocistronic transcripts. Moreover, the upstream located ado gene is driven by a proximal as well as a second, distal, promoter, from which a third transcript, the ~160 nt sRNA SyR9 is transcribed. Thus, the transcriptional organization of the alkane biosynthesis genes in Synechocystis sp. PCC 6803 is of substantial complexity. We verified all three promoters to function independently from each other and show a similar promoter arrangement also in the more distant Nodularia spumigena, Trichodesmium erythraeum, Anabaena sp. PCC 7120, Prochlorococcus MIT9313 and MED4. The presence of separate regulatory elements and the dominance of monocistronic mRNAs suggest the possible autonomous regulation of ado and aar. The complex transcriptional organization of the alkane synthesis gene cluster has possible metabolic implications and should be considered when manipulating the expression of these genes in

  2. Toxic effects of amoxicillin on the photosystem II of Synechocystis sp. characterized by a variety of in vivo chlorophyll fluorescence tests

    International Nuclear Information System (INIS)

    Pan Xiangliang; Deng Chunnuan; Zhang Daoyong; Wang Jianlong; Mu Guijin; Chen Ying

    2008-01-01

    Amoxicillin is one of the widely used antibiotics of environmental concern. This study shows that amoxicillin has toxic effects on the photosynthesis of Synechocystis sp. Its inhibitory effects on photosystem II (PSII) of Synechocystis sp. were investigated by using a variety of in vivo chlorophyll fluorescence tests. The inhibitory effects of amoxicillin on PSII activity of Synechocystis sp. are concentration-dependent. Amoxicillin exposure leads to slowing down of electron transport on both donor side and acceptor side and causes accumulation of P680 + . Q A - reoxidation test revealed that amoxicillin hinders electron transfer from Q A - to Q B /Q B - and more Q A - is oxidized through S 2 (Q A Q B ) - charge recombination. Analysis of PSII heterogeneity demonstrated that an exposure to amoxicillin increases the proportion of inactive PSII (PSII X ) centers and the proportion of PSII centers with small antenna (PSIIβ). These changes finally result in deterioration of full photosynthesis performance

  3. Cyanobacteria Biorefinery - Production of poly(3-hydroxybutyrate) with Synechocystis salina and utilisation of residual biomass.

    Science.gov (United States)

    Meixner, K; Kovalcik, A; Sykacek, E; Gruber-Brunhumer, M; Zeilinger, W; Markl, K; Haas, C; Fritz, I; Mundigler, N; Stelzer, F; Neureiter, M; Fuchs, W; Drosg, B

    2018-01-10

    This study evaluates a biorefinery concept for producing poly(3-hydroxybutyrate) (PHB) with the cyanobacterial strain Synechocystis salina. Due to this reason, pigment extraction and cell disruption were investigated as pre-treatment steps for the harvested cyanobacterial biomass. The results demonstrated that at least pigment removal was necessary to obtain PHB with processable quality (weight average molecular weight: 569-988kgmol -1 , melting temperature: 177-182°C), which was comparable to heterotrophically produced PHB. The removed pigments could be utilised as additional by-products (chlorophylls 0.27-1.98mgg -1 TS, carotenoids 0.21-1.51mgg -1 TS, phycocyanin 0-127mgg -1 TS), whose concentration depended on the used nutrient source. Since the residual biomass still contained proteins (242mgg -1 TS), carbohydrates (6.1mgg -1 TS) and lipids (14mgg -1 TS), it could be used as animal feed or converted to biomethane (348 m n 3 t -1 VS) and fertiliser. The obtained results indicate that the combination of photoautotrophic PHB production with pigment extraction and utilisation of residual biomass offer the highest potential, since it contributes to decrease the environmental footprint of the process and because biomass could be used in a cascading way and the nutrient cycle could be closed. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Statistical evaluation of nutritional components impacting phycocyanin production in Synechocystis SP

    Directory of Open Access Journals (Sweden)

    Devendra V. Deshmukh

    2012-03-01

    Full Text Available Alkaliphilic cyanobacterial cultures were isolated from Lonar lake (MS, India. Among the set of cultures, Synechocystis sp, was studied for phycocyanin production. A maximum yield was obtained in BG-11 medium at optimized conditions (pH 10 and 16 h light. In order to increase the phycocyanin yield media optimization based on the eight media components a Plackett-Burman design of the 12 experimental trials was used. As per the analysis CaCl2.2H2O and Na2CO3 have been found to be the most influencing media components at 95% significance. Further the optimum concentrations of these components were estimated following a Box Wilson Central Composite Design (CCD with four star points and five replicates at the center points for each of two factors was adopted for optimization of these two media components. The results indicated that there was an interlinked influence of CaCl2.2H2O and Na2CO3 on 98% significance. The maximum yield of phycocyanin (12% of dry wt could be obtained at 0.058 g/l and 0.115 g/l of CaCl2.2H2O and Na2CO3, respectively.

  5. Spectral characteristic of fluorescence induction in a model cyanobacterium, Synechococcus sp. (PCC 7942)

    Czech Academy of Sciences Publication Activity Database

    Kaňa, Radek; Prášil, Ondřej; Komárek, Ondřej; Papageorgiou, G. C.; Govindjee, G.

    2009-01-01

    Roč. 1787, č. 10 (2009), s. 1170-1178 ISSN 0005-2728 R&D Projects: GA ČR GP206/09/P094; GA ČR GA206/07/0917; GA AV ČR IAA608170603 Institutional research plan: CEZ:AV0Z50200510; CEZ:AV0Z60870520 Keywords : fluorescence induction * cyanobacterium * PCC 7942 Subject RIV: EE - Microbiology, Virology Impact factor: 3.688, year: 2009

  6. Isolation and description of a globally distributed cryosphere cyanobacterium from Antarctica

    OpenAIRE

    Ji Won Hong; Sung Hong Kim; Han-Gu Choi; Sung-Ho Kang; Ho-Sung Yoon

    2013-01-01

    A previously uncultured cyanobacterium, strain KNUA009, was axenically isolated from a meltwater stream on Barton Peninsula, King George Island, South Shetland Islands, Antarctica. Molecular evidences showed that the isolate belongs to groups of globally distributed cryosphere cyanobacterial clones and this new isolate represents the first laboratory culture to be assigned to these groups. Strain KNUA009 was able to thrive at low temperatures ranging between 5°C and 20°C, but did not survive ...

  7. Discovery of a Chllorophyll Binding Protein Complex Involved in the Early Steps of Photosystem II Assembly in Synechocystis

    Czech Academy of Sciences Publication Activity Database

    Knoppová, Jana; Sobotka, Roman; Tichý, Martin; Jianfeng, Yu; Koník, P.; Halada, Petr; Nixon, P. J.; Komenda, Josef

    2014-01-01

    Roč. 26, č. 4 (2014), s. 1200-1212 ISSN 1040-4651 R&D Projects: GA ČR P501/11/0377; GA MŠk ED2.1.00/03.0110 Grant - others:UK Biotechnology and Biological Sciences Research Council(GB) BB/F020554/1; UK Biotechnology and Biological Sciences Research Council(GB) BB/L003260/1; Magistrát hl. m. Prahy(CZ) CZ.2.16/3.1.00/24023 Institutional support: RVO:61388971 Keywords : Synechocystis * photosystem II * assembly * proteins Subject RIV: EE - Microbiology, Virology Impact factor: 9.338, year: 2014

  8. An Alcohol Dehydrogenase Gene from Synechocystis sp. Confers Salt Tolerance in Transgenic Tobacco

    Directory of Open Access Journals (Sweden)

    So Young Yi

    2017-11-01

    Full Text Available Synechocystis salt-responsive gene 1 (sysr1 was engineered for expression in higher plants, and gene construction was stably incorporated into tobacco plants. We investigated the role of Sysr1 [a member of the alcohol dehydrogenase (ADH superfamily] by examining the salt tolerance of sysr1-overexpressing (sysr1-OX tobacco plants using quantitative real-time polymerase chain reactions, gas chromatography-mass spectrometry, and bioassays. The sysr1-OX plants exhibited considerably increased ADH activity and tolerance to salt stress conditions. Additionally, the expression levels of several stress-responsive genes were upregulated. Moreover, airborne signals from salt-stressed sysr1-OX plants triggered salinity tolerance in neighboring wild-type (WT plants. Therefore, Sysr1 enhanced the interconversion of aldehydes to alcohols, and this occurrence might affect the quality of green leaf volatiles (GLVs in sysr1-OX plants. Actually, the Z-3-hexenol level was approximately twofold higher in sysr1-OX plants than in WT plants within 1–2 h of wounding. Furthermore, analyses of WT plants treated with vaporized GLVs indicated that Z-3-hexenol was a stronger inducer of stress-related gene expression and salt tolerance than E-2-hexenal. The results of the study suggested that increased C6 alcohol (Z-3-hexenol induced the expression of resistance genes, thereby enhancing salt tolerance of transgenic plants. Our results revealed a role for ADH in salinity stress responses, and the results provided a genetic engineering strategy that could improve the salt tolerance of crops.

  9. Improved biomass and lipid production in Synechocystis sp. NN using industrial wastes and nano-catalyst coupled transesterification for biodiesel production.

    Science.gov (United States)

    Jawaharraj, Kalimuthu; Karpagam, Rathinasamy; Ashokkumar, Balasubramaniem; Kathiresan, Shanmugam; Moorthy, Innasi Muthu Ganesh; Arumugam, Muthu; Varalakshmi, Perumal

    2017-10-01

    In this study, the improved biomass (1.6 folds) and lipid (1.3 folds) productivities in Synechocystis sp. NN using agro-industrial wastes supplementation through hybrid response surface methodology-genetic algorithm (RSM-GA) for cost-effective methodologies for biodiesel production was achieved. Besides, efficient harvesting in Synechocystis sp. NN was achieved by electroflocculation (flocculation efficiency 97.8±1.2%) in 10min when compared to other methods. Furthermore, different pretreatment methods were employed for lipid extraction and maximum lipid content of 19.3±0.2% by Synechocystis sp. NN was attained by ultrasonication than microwave and liquid nitrogen assisted pretreatment methods. The highest FAME (fatty acid methyl ester) conversion of 36.5±8.3mg FAME/g biomass was obtained using titanium oxide as heterogeneous nano-catalyst coupled whole-cell transesterification based method. Conclusively, Synechocystis sp. NN may be used as a biodiesel feedstock and its fuel production can be enriched by hybrid RSM-GA and nano-catalyst technologies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Psb28 protein is involved in the biogenesis of the photosystem II inner antenna CP47 (PsbB) in the cyanobacterium Synechocystis sp. PCC 68031[W][OA

    Czech Academy of Sciences Publication Activity Database

    Dobáková, Marika; Sobotka, Roman; Tichý, Martin; Komenda, Josef

    2009-01-01

    Roč. 179, - (2009), s. 1076-1086 ISSN 0032-0889 R&D Projects: GA ČR GA206/06/0322; GA AV ČR IAA400200801 Institutional research plan: CEZ:AV0Z50200510 Keywords : REACTION-CENTER COMPLEX * ARABIDOPSIS-THALIANA * MUTANTS Subject RIV: EE - Microbiology, Virology Impact factor: 6.235, year: 2009

  11. ORF Alignment: NC_000911 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available p. (strain PCC 6803) ... Length = 180 ... Query: 1034 KQVLIVDDNETNRRILQDQCQAWGLVCHCFTSGESALDWFARC...PDLDAAILDLQMPNMDG 1093 ... KQVLIVDDNETNRRILQDQCQAWGLVCHCFTSGESALDWFARCPDLDAAILDL...QMPNMDG Sbjct: 1 ... KQVLIVDDNETNRRILQDQCQAWGLVCHCFTSGESALDWFARCPDLDAAILDLQMPNMDG 60 ... Query: 1154 GLADYAPQFDQ

  12. First description of a cyanophage infecting the cyanobacterium Arthrospira platensis (Spirulina)

    Digital Repository Service at National Institute of Oceanography (India)

    Jacquet, S.; Zhong, X.; Parvathi, A.; Ram, A.S.P.

    CARRTEL, 75 Avenue de Corzent, 74203 Thonon-les-Bains cx, France 2. National Institute of Oceanography, Dr Salim Ali Road, PO Box 1913, Kochi, 682018 India 3. Laboratoire Microorganismes : Génome et Environnment, UMR CNRS 6023, Clermont Université... obtained from “le chant de l’eau”, an exploitation based in the south of France (Fuilla) and consisting of 8 pools of 70 -200 m2. Growth conditions of the cyanobacterium have been described in Jourdan (2006). Briefly, A. platensis grew in outdoor...

  13. Cyanobacteria as an Experimental Platform for Modifying Bacterial and Plant Photosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Poul Erik [Copenhagen Plant Science Center (CPSC), Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen (Denmark); Leister, Dario, E-mail: leister@lmu.de [Copenhagen Plant Science Center (CPSC), Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen (Denmark); Plant Molecular Biology (Botany), Department of Biology I, Ludwig-Maximilians-University Munich, Munich (Germany)

    2014-04-21

    One of the fascinating characteristics of photosynthesis is its capacity for repair, self-renewal, and energy storage within chemical bonds. Given the evolutionary history of plant photosynthesis and the patchwork nature of many of its components, it is safe to assume that the light reactions of plant photosynthesis can be improved by genetic engineering (Leister, 2012). The evolutionary precursor of chloroplasts was a microorganism whose biochemistry was very similar to that of present-day cyanobacteria. Many cyanobacterial species are easy to manipulate genetically and grow robustly in liquid cultures that can be easily scaled up into photobioreactors. Therefore, cyanobacteria such as Synechocystis sp. PCC 6803 (hereafter “Synechocystis”) have widely been used for decades as model systems to study the principles of photosynthesis (Table 1). Indeed, genetic engineering based on homologous recombination is well-established in Synechocystis. Moreover, new genetic engineering toolkits, including marker-less gene deletion and replacement strategies needing only a single transformation step (Viola et al., 2014) and novel approaches for chromosomal integration and expression of synthetic gene operons (Bentley et al., 2014), allow for large-scale replacement and/or integration of dozens of genes in reasonable time frames. This makes Synechocystis a very attractive basis for the experimental modification of important processes like photosynthesis, and it also suggests innovative ways of improving modules of related eukaryotic pathways, among them the combination of cyanobacterial and eukaryotic elements using the tools of synthetic biology.

  14. Cyanobacteria as an Experimental Platform for Modifying Bacterial and Plant Photosynthesis

    International Nuclear Information System (INIS)

    Jensen, Poul Erik; Leister, Dario

    2014-01-01

    One of the fascinating characteristics of photosynthesis is its capacity for repair, self-renewal, and energy storage within chemical bonds. Given the evolutionary history of plant photosynthesis and the patchwork nature of many of its components, it is safe to assume that the light reactions of plant photosynthesis can be improved by genetic engineering (Leister, 2012). The evolutionary precursor of chloroplasts was a microorganism whose biochemistry was very similar to that of present-day cyanobacteria. Many cyanobacterial species are easy to manipulate genetically and grow robustly in liquid cultures that can be easily scaled up into photobioreactors. Therefore, cyanobacteria such as Synechocystis sp. PCC 6803 (hereafter “Synechocystis”) have widely been used for decades as model systems to study the principles of photosynthesis (Table 1). Indeed, genetic engineering based on homologous recombination is well-established in Synechocystis. Moreover, new genetic engineering toolkits, including marker-less gene deletion and replacement strategies needing only a single transformation step (Viola et al., 2014) and novel approaches for chromosomal integration and expression of synthetic gene operons (Bentley et al., 2014), allow for large-scale replacement and/or integration of dozens of genes in reasonable time frames. This makes Synechocystis a very attractive basis for the experimental modification of important processes like photosynthesis, and it also suggests innovative ways of improving modules of related eukaryotic pathways, among them the combination of cyanobacterial and eukaryotic elements using the tools of synthetic biology.

  15. Genetic and nutrient modulation of acetyl-CoA levels in Synechocystis for n-butanol production

    DEFF Research Database (Denmark)

    Anfelt, Josefine; Kaczmarzyk, Danuta; Shabestary, Kiyan

    2015-01-01

    There is a strong interest in using photosynthetic cyanobacteria as production hosts for biofuels and chemicals. Recent work has shown the benefit of pathway engineering, enzyme tolerance, and co-factor usage for improving yields of fermentation products. An n-butanol pathway was inserted...... productivity than CBB-Embden-Meyerhof-Parnas and a reduced butanol ATP demand. These results demonstrate that phosphoketolase overexpression and modulation of nitrogen levels are two attractive routes toward increased production of acetyl-CoA derived products in cyanobacteria and could be implemented...... into a Synechocystis mutant deficient in polyhydroxybutyrate synthesis. We found that nitrogen starvation increased specific butanol productivity up to threefold, but cessation of cell growth limited total n-butanol titers. Metabolite profiling showed that acetyl-CoA increased twofold during nitrogen starvation...

  16. Biotechnological potential of Synechocystis salina co-cultures with selected microalgae and cyanobacteria: Nutrients removal, biomass and lipid production.

    Science.gov (United States)

    Gonçalves, Ana L; Pires, José C M; Simões, Manuel

    2016-01-01

    Cultivation of microalgae and cyanobacteria has been the focus of several research studies worldwide, due to the huge biotechnological potential of these photosynthetic microorganisms. However, production of these microorganisms is still not economically viable. One possible alternative to improve the economic feasibility of the process is the use of consortia between microalgae and/or cyanobacteria. In this study, Chlorella vulgaris, Pseudokirchneriella subcapitata and Microcystis aeruginosa were co-cultivated with Synechocystis salina to evaluate how dual-species cultures can influence biomass and lipid production and nutrients removal. Results have shown that the three studied consortia achieved higher biomass productivities than the individual cultures. Additionally, nitrogen and phosphorus consumption rates by the consortia provided final concentrations below the values established by European Union legislation for these nutrients. In the case of lipid productivities, higher values were determined when S. salina was co-cultivated with P. subcapitata and M. aeruginosa. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Integrated Bacillus sp. immobilized cell reactor and Synechocystis sp. algal reactor for the treatment of tannery wastewater.

    Science.gov (United States)

    Sekaran, G; Karthikeyan, S; Nagalakshmi, C; Mandal, A B

    2013-01-01

    The wastewater discharged from leather industries lack biodegradability due to the presence of xenobiotic compounds. The primary clarification and aerobic treatment in Bacillus sp. immobilized Chemo Autotrophic Activated Carbon Oxidation (CAACO) reactor removed considerable amount of pollution parameters. The residual untreated organics in the wastewater was further treated in algal batch reactor inoculated with Synechocystis sp. Sodium nitrate, K(2)HPO(4), MgSO(4).7H(2)O, NH(4)Cl, CaCl(2)·2H(2)O, FeCl(3) (anhydrous), and thiamine hydrochloride, rice husk based activated carbon (RHAC), immobilization of Bacillus sp. in mesoporous activated carbon, sand filter of dimensions diameter, 6 cm and height, 30 cm; and the CAACO reactor of dimensions diameter, 5.5 cm and height, 30 cm with total volume 720 ml, and working volume of 356 ml. In the present investigation, the CAACO treated tannery wastewater was applied to Synechocystis sp. inoculated algal batch reactor of hydraulic residence time 24 h. The BOD(5), COD, and TOC of treated wastewater from algal batch reactor were 20 ± 7, 167 ± 29, and 78 ± 16 mg/l respectively. The integrated CAACO system and Algal batch reactor was operated for 30 days and they accomplished a cumulative removal of BOD(5),COD, TOC, VFA and sulphide as 98 %, 95 %, 93 %, 86 %, and 100 %, respectively. The biokinetic constants for the growth of algae in the batch reactor were specific growth rate, 0.095(day(-1)) and yield coefficient, 3.15 mg of algal biomass/mg of COD destructed. The degradation of xenobiotic compounds in the algal batch reactor was confirmed through HPLC and FT-IR techniques. The integrated CAACO-Algal reactor system established a credible reduction in pollution parameters in the tannery wastewater. The removal mechanism is mainly due to co-metabolism between algae and bacterial species and the organics were completely metabolized rather than by adsorption.

  18. Dynamics of the Toxin Cylindrospermopsin and the Cyanobacterium Chrysosporum (Aphanizomenon ovalisporum in a Mediterranean Eutrophic Reservoir

    Directory of Open Access Journals (Sweden)

    Ali Fadel

    2014-10-01

    Full Text Available Chrysosporum ovalisporum is a cylindrospermopsin toxin producing cyanobacterium that was reported in several lakes and reservoirs. Its growth dynamics and toxin distribution in field remain largely undocumented. Chrysosporum ovalisporum was reported in 2009 in Karaoun Reservoir, Lebanon. We investigated the factors controlling the occurrence of this cyanobacterium and vertical distribution of cylindrospermopsin in Karaoun Reservoir. We conducted bi-weekly sampling campaigns between May 2012 and August 2013. Results showed that Chrysosporum ovalisporum is an ecologically plastic species that was observed in all seasons. Unlike the high temperatures, above 26 °C, which is associated with blooms of Chrysosporum ovalisporum in Lakes Kinneret (Israel, Lisimachia and Trichonis (Greece and Arcos Reservoir (Spain, Chrysosporum ovalisporum in Karaoun Reservoir bloomed in October 2012 at a water temperature of 22 °C during weak stratification. Cylindrospermopsin was detected in almost all water samples even when Chrysosporum ovalisporum was not detected. Chrysosporum ovalisporum biovolumes and cylindrospermopsin concentrations were not correlated (n = 31, r2 = −0.05. Cylindrospermopsin reached a maximum concentration of 1.7 µg L−1. The vertical profiles of toxin concentrations suggested its possible degradation or sedimentation resulting in its disappearance from the water column. The field growth conditions of Chrysosporum ovalisporum in this study revealed that it can bloom at the subsurface water temperature of 22 °C increasing the risk of its development and expansion in lakes located in temperate climate regions.

  19. Diurnal Rhythms Result in Significant Changes in the Cellular Protein Complement in the Cyanobacterium Cyanothece 51142

    Energy Technology Data Exchange (ETDEWEB)

    Stockel, Jana; Jacobs, Jon M.; Elvitigala, Thanura R.; Liberton, Michelle L.; Welsh, Eric A.; Polpitiya, Ashoka D.; Gritsenko, Marina A.; Nicora, Carrie D.; Koppenaal, David W.; Smith, Richard D.; Pakrasi, Himadri B.

    2011-02-22

    Cyanothece sp. ATCC 51142 is a diazotrophic cyanobacterium notable for its ability to perform oxygenic photosynthesis and dinitrogen fixation in the same single cell. Previous transcriptional analysis revealed that the existence of these incompatible cellular processes largely depends on tightly synchronized expression programs involving ,30% of genes in the genome. To expand upon current knowledge, we have utilized sensitive proteomic approaches to examine the impact of diurnal rhythms on the protein complement in Cyanothece 51142. We found that 250 proteins accounting for,5% of the predicted ORFs from the Cyanothece 51142 genome and 20% of proteins detected under alternating light/dark conditions exhibited periodic oscillations in their abundances. Our results suggest that altered enzyme activities at different phases during the diurnal cycle can be attributed to changes in the abundance of related proteins and key compounds. The integration of global proteomics and transcriptomic data further revealed that post-transcriptional events are important for temporal regulation of processes such as photosynthesis in Cyanothece 51142. This analysis is the first comprehensive report on global quantitative proteomics in a unicellular diazotrophic cyanobacterium and uncovers novel findings about diurnal rhythms.

  20. Discovery of an endosymbiotic nitrogen-fixing cyanobacterium UCYN-A in Braarudosphaera bigelowii (Prymnesiophyceae.

    Directory of Open Access Journals (Sweden)

    Kyoko Hagino

    Full Text Available Braarudosphaera bigelowii (Prymnesiophyceae is a coastal coccolithophore with a long fossil record, extending back to the late Cretaceous (ca. 100 Ma. A recent study revealed close phylogenetic relationships between B. bigelowii, Chrysochromulina parkeae (Prymnesiophyceae, and a prymnesiophyte that forms a symbiotic association with the nitrogen-fixing cyanobacterium UCYN-A. In order to further examine these relationships, we conducted transmission electron microscopic and molecular phylogenetic studies of B. bigelowii. TEM studies showed that, in addition to organelles, such as the nucleus, chloroplasts and mitochondria, B. bigelowii contains one or two spheroid bodies with internal lamellae. In the 18S rDNA tree of the Prymnesiophyceae, C. parkeae fell within the B. bigelowii clade, and was close to B. bigelowii Genotype III (99.89% similarity. Plastid 16S rDNA sequences obtained from B. bigelowii were close to the unidentified sequences from the oligotrophic SE Pacific Ocean (e.g. HM133411 (99.86% similarity. Bacterial16S rDNA sequences obtained from B. bigelowii were identical to the UCYN-A sequence AY621693 from Arabian Sea, and fell in the UCYN-A clade. From these results, we suggest that; 1 C. parkeae is the alternate life cycle stage of B. bigelowii sensu stricto or that of a sibling species of B. bigelowii, and 2 the spheroid body of B. bigelowii originated from endosymbiosis of the nitrogen-fixing cyanobacterium UCYN-A.

  1. Aluminum effects on uptake and metabolism of phosphorus by the Cyanobacterium Anabaena cylindrica

    International Nuclear Information System (INIS)

    Pettersson, A.; Haellbom, L.; Bergman, B.

    1988-01-01

    Aluminum severely affects the growth of the cyanobacterium Anabaena cylindrica and induces symptoms indicating phosphorus starvation. Pre- or post-treating the cells with high (90 micromolar) phosphorus reduces the toxicity of aluminum compared to cells receiving a lower orthophosphate concentration. In this study aluminum (ranging from 9 to 36 micromolar) and phosphorus concentrations were chosen so that the precipitation of insoluble AlPO 4 never exceeded 10% of the total phosphate concentration. The uptake of 32 P-phosphorus is not disturbed by aluminium either at high (100 micromolar) or low (10 micromolar) concentrations of phosphate. Also, the rapid accumulation of polyphosphate granules in cells exposed to aluminum indicates that the incorporation of phosphate is not disturbed. However, a significant decrease in the mobilization of the polyphosphates is observed, as is a lowered activity of the enzyme acid phosphatase, in aluminum treated cells. We conclude that aluminum acts on the intracellular metabolism of phosphate, which eventually leads to phosphorus starvation rather than on its uptake in the cyanobacterium A. cylindrica

  2. Collapsing aged culture of the cyanobacterium Synechococcus elongatus produces compound(s toxic to photosynthetic organisms.

    Directory of Open Access Journals (Sweden)

    Assaf Cohen

    Full Text Available Phytoplankton mortality allows effective nutrient cycling, and thus plays a pivotal role in driving biogeochemical cycles. A growing body of literature demonstrates the involvement of regulated death programs in the abrupt collapse of phytoplankton populations, and particularly implicates processes that exhibit characteristics of metazoan programmed cell death. Here, we report that the cell-free, extracellular fluid (conditioned medium of a collapsing aged culture of the cyanobacterium Synechococcus elongatus is toxic to exponentially growing cells of this cyanobacterium, as well as to a large variety of photosynthetic organisms, but not to eubacteria. The toxic effect, which is light-dependent, involves oxidative stress, as suggested by damage alleviation by antioxidants, and the very high sensitivity of a catalase-mutant to the conditioned medium. At relatively high cell densities, S. elongatus cells survived the deleterious effect of conditioned medium in a process that required de novo protein synthesis. Application of conditioned medium from a collapsing culture caused severe pigment bleaching not only in S. elongatus cells, but also resulted in bleaching of pigments in a cell free extract. The latter observation indicates that the elicited damage is a direct effect that does not require an intact cell, and therefore, is mechanistically different from the metazoan-like programmed cell death described for phytoplankton. We suggest that S. elongatus in aged cultures are triggered to produce a toxic compound, and thus, this process may be envisaged as a novel regulated death program.

  3. The Effect of Small Scale Turbulence on the Physiology of Microcystis aeruginosa cyanobacterium

    Science.gov (United States)

    Wilkinson, Anne; Hondzo, Miki; Guala, Michele

    2014-11-01

    Microcystis aeruginosa is a single-celled blue-green alga, or cyanobacterium, that is responsible for poor water quality and microcystin production, which in high concentrations can be harmful to humans and animals. These harmful effects arise during cyanobacterium blooms. Blooms occur mainly in the summer when the algae grow uncontrollably and bond together to form colonies which accumulate on the surface of freshwater ecosystems. The relationship between fluid motion generated by wind and internal waves in stratified aquatic ecosystems and Microcystis can help explain the mechanisms of such blooms. We investigated the effect of small scale fluid motion on the physiology of Microcystis in a reactor with two underwater speakers. Different turbulent intensities were achieved by systematically changing the input signal frequency (30-50 Hz) and magnitude (0.1-0.2V) to the speakers. The role of turbulence is quantified by relating energy dissipation rates with the cell number, chlorophyll amount, dissolved oxygen production/uptake, and pH. The results suggest that turbulence mediates the physiology of Microcystis. The findings could be instrumental in designing restoration strategies that can minimize Microcystis blooms. This work was supported by the NSF Graduate Research Fellowship and University of Minnesota start-up funding.

  4. Growth of Cyanobacterium aponinum influenced by increasing salt concentrations and temperature.

    Science.gov (United States)

    Winckelmann, Dominik; Bleeke, Franziska; Bergmann, Peter; Klöck, Gerd

    2015-06-01

    The increasing requirement of food neutral biofuels demands the detection of alternative sources. The use of non-arable land and waste water streams is widely discussed in this regard. A Cyanobacterium was isolated on the area of a possible algae production side near a water treatment plant in the arid desert region al-Wusta. It was identified as Cyanobacterium aponinum PB1 and is a possible lipid source. To determine its suitability of a production process using this organism, a set of laboratory experiments were performed. Its growth behavior was examined in regard to high temperatures and increasing NaCl concentrations. A productivity of 0.1 g L -1 per day was measured at an alga density below 0.75 g L -1 . C. aponinum PB1 showed no sign of altered growth behavior in media containing 70 g L -1 NaCl or less. Detection of a negative effect of NaCl on the growth using Pulse-Amplitude-Modulation chlorophyll fluorescence analysis was not more sensitive than optical density measurement.

  5. Potassium sensitivity differs among strains of the harmful cyanobacterium Microcystis and correlates with the presence of salt tolerance genes

    NARCIS (Netherlands)

    Sandrini, G.; Huisman, J.; Matthijs, H.C.P.

    2015-01-01

    Microcystis aeruginosa is a ubiquitous harmful cyanobacterium that causes problems in eutrophic lakes. Potassium ion (K+) addition is one of the suggested methods to combat harmful cyanobacterial blooms. To investigate the effectiveness of this method, we compared the potassium ion sensitivity of

  6. A comparison of fermentation in the cyanobacterium Microcystis PCC7806 grown under a light/dark cycle and continuous light

    NARCIS (Netherlands)

    Moezelaar, R.; Stal, L.J.

    1997-01-01

    The cyanobacterium Microcystis PCC7806, grown under continuous light, fermented endogenously stored glycogen to equimolar amounts of acetate and ethanol when incubated anaerobically in the dark. In addition, H-2, CO2 and some L-lactate were produced. This fermentation pattern differed from that

  7. Mono-, di- and trimeric PS I reaction center complexes isolated from the thermophilic cyanobacterium Synechococcus sp. Size, shape and activity

    NARCIS (Netherlands)

    Rögner, M.; Mühlenhoff, U.; Boekema, E.J.; Witt, H.T.

    1990-01-01

    Photosystem I preparations from the cyanobacterium Synechococcus sp. were treated with high concentrations of Tris and octyl glucoside at alkaline pH and elevated temperature. A sucrose density gradient yielded three pigment-protein complexes; these were further purified on a HPLC anion-exchange

  8. Inducible expression of heterologous genes targeted to a chromosomal platform in the cyanobacterium Synechococcus sp. PCC 7942

    NARCIS (Netherlands)

    Geerts, D.; Bovy, A.; de Vrieze, G.; Borrias, M.; Weisbeek, P.

    1995-01-01

    High-level, inducible expression of heterologous genes in the cyanobacterium Synechococcus sp. strain PCC 7942 was obtained using the Escherichia coli trc promoter and lacI repressor. The petE gene of Anabaena sp. strain PCC 7937 encoding plastocyanin precursor protein and the E. coli uidA gene

  9. Two-Step Separation of Nostotrebin 6 from Cultivated Soil Cyanobacterium (Nostoc sp.) by High Performance Countercurrent Chromatography

    Czech Academy of Sciences Publication Activity Database

    Cheel, José; Kučerová, P.; Garrard, I.; Ignatova, S.; Hrouzek, Pavel; Kopecký, Jiří

    2014-01-01

    Roč. 19, č. 4 (2014), s. 8773-8787 ISSN 1420-3049 R&D Projects: GA MŠk ED2.1.00/03.0110; GA MŠk EE2.3.30.0059 Institutional support: RVO:61388971 Keywords : nostotrebin 6 * cyanobacterium * Nostoc * HPLC separation Subject RIV: EE - Microbiology, Virology Impact factor: 2.416, year: 2014

  10. Toxic effects of amoxicillin on the photosystem II of Synechocystis sp. characterized by a variety of in vivo chlorophyll fluorescence tests

    Energy Technology Data Exchange (ETDEWEB)

    Pan Xiangliang [Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumuqi, 830011 (China); State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550002 (China); Deng Chunnuan [Northeast Institute of Geography and Agricultural Ecology, Chinese Academy of Sciences, Changchun, 130012 (China); Yunnan Normal University, Kunming 650092 (China); Zhang Daoyong [Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumuqi, 830011 (China); State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550002 (China)], E-mail: zhangdaoyong@vip.gyig.ac.cn; Wang Jianlong [Institute of Nuclear Energy and Technology, Tsinghua University, Beijing, 100083 (China); Mu Guijin [Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumuqi, 830011 (China); Chen Ying [Yunnan Normal University, Kunming 650092 (China)

    2008-09-29

    Amoxicillin is one of the widely used antibiotics of environmental concern. This study shows that amoxicillin has toxic effects on the photosynthesis of Synechocystis sp. Its inhibitory effects on photosystem II (PSII) of Synechocystis sp. were investigated by using a variety of in vivo chlorophyll fluorescence tests. The inhibitory effects of amoxicillin on PSII activity of Synechocystis sp. are concentration-dependent. Amoxicillin exposure leads to slowing down of electron transport on both donor side and acceptor side and causes accumulation of P680{sup +}. Q{sub A}{sup -} reoxidation test revealed that amoxicillin hinders electron transfer from Q{sub A}{sup -} to Q{sub B}/Q{sub B}{sup -} and more Q{sub A}{sup -} is oxidized through S{sub 2}(Q{sub A}Q{sub B}){sup -} charge recombination. Analysis of PSII heterogeneity demonstrated that an exposure to amoxicillin increases the proportion of inactive PSII (PSII{sub X}) centers and the proportion of PSII centers with small antenna (PSII{beta}). These changes finally result in deterioration of full photosynthesis performance.

  11. Identification and Regulation of Genes for Cobalamin Transport in the Cyanobacterium Synechococcus sp. Strain PCC 7002.

    Science.gov (United States)

    Pérez, Adam A; Rodionov, Dmitry A; Bryant, Donald A

    2016-10-01

    The cyanobacterium Synechococcus sp. strain PCC 7002 is a cobalamin auxotroph and utilizes this coenzyme solely for the synthesis of l-methionine by methionine synthase (MetH). Synechococcus sp. strain PCC 7002 is unable to synthesize cobalamin de novo, and because of the large size of this tetrapyrrole, an active-transport system must exist for cobalamin uptake. Surprisingly, no cobalamin transport system was identified in the initial annotation of the genome of this organism. With more sophisticated in silico prediction tools, a btuB-cpdA-btuC-btuF operon encoding components putatively required for a B12 uptake (btu) system was identified. The expression of these genes was predicted to be controlled by a cobalamin riboswitch. Global transcriptional profiling by high-throughput RNA sequencing of a cobalamin-independent form of Synechococcus sp. strain PCC 7002 grown in the absence or presence of cobalamin confirmed regulation of the btu operon by cobalamin. Pérez et al. (A. A. Pérez, Z. Liu, D. A. Rodionov, Z. Li, and D. A. Bryant, J Bacteriol 198:2743-2752, 2016, http://dx.doi.org/10.1128/JB.00475-16) developed a cobalamin-dependent yellow fluorescent protein reporter system in a Synechococcus sp. strain PCC 7002 variant that had been genetically modified to allow cobalamin-independent growth. This reporter system was exploited to validate components of the btu uptake system by assessing the ability of targeted mutants to transport cobalamin. The btuB promoter and a variant counterpart mutated in an essential element of the predicted cobalamin riboswitch were fused to a yfp reporter. The combined data indicate that the btuB-cpdA-btuF-btuC operon in this cyanobacterium is transcriptionally regulated by a cobalamin riboswitch. With a cobalamin-regulated reporter system for expression of yellow fluorescent protein, genes previously misidentified as encoding subunits of a siderophore transporter were shown to encode components of cobalamin uptake in the

  12. Genetic transformation of marine cyanobacterium Synechococcus sp. CC9311 (Cyanophyceae) by electroporation

    Science.gov (United States)

    Chen, Huaxin; Lin, Hanzhi; Jiang, Peng; Li, Fuchao; Qin, Song

    2013-03-01

    Synechococcus sp. CC9311 is a marine cyanobacterium characterized by type IV chromatic acclimation (CA). A genetic transformation system was developed as a first step to elucidate the molecular mechanism of CA. The results show that Synechococcus sp. CC9311 cells were sensitive to four commonly used antibiotics: ampicillin, kanamycin, spectinomycin, and chloramphenicol. An integrative plasmid to disrupt the putative phycoerythrin lyase gene mpeV, using a kanamycin resistance gene as selectable marker, was constructed by recombinant polymerase chain reaction. The plasmid was then transformed into Synechococcus sp. CC9311 via electroporation. High transformation efficiency was achieved at a field strength of 2 kV/cm. DNA analysis showed that mpeV was fully disrupted following challenge of the transformants with a high concentration of kanamycin. In addition, the transformants that displayed poor growth on agar SN medium could be successfully plated on agarose SN medium.

  13. Metabolism of phenanthrene by the marine cyanobacterium Agmenellum quadruplicatum PR-6.

    Science.gov (United States)

    Narro, M L; Cerniglia, C E; Van Baalen, C; Gibson, D T

    1992-01-01

    Under photoautotrophic growth conditions, the marine cyanobacterium Agmenellum quadruplicatum PR-6 metabolized phenanthrene to form trans-9,10-dihydroxy-9,10-dihydrophenanthrene (phenanthrene trans-9,10-dihydrodiol) and 1-methoxyphenanthrene as the major ethyl acetate-extractable metabolites. Small amounts of phenanthrols were also formed. The metabolites were purified by high-pressure liquid chromatography and identified from their UV, infrared, mass, and proton magnetic resonance spectral properties. A. quadruplicatum PR-6 formed phenanthrene trans-9,10-dihydrodiol with a 22% enantiomeric excess of the (-)-9S,10S-enantiomer. Incorporation experiments with 18O2 showed that one atom of oxygen from O2 was incorporated into the dihydrodiol. Toxicity studies, using an algal lawn bioassay, indicated that 9-phenanthrol and 9,10-phenanthrenequinone inhibit the growth of A. quadruplicatum PR-6. PMID:1599252

  14. Sacrolide A, a new antimicrobial and cytotoxic oxylipin macrolide from the edible cyanobacterium Aphanothece sacrum.

    Science.gov (United States)

    Oku, Naoya; Matsumoto, Miyako; Yonejima, Kohsuke; Tansei, Keijiroh; Igarashi, Yasuhiro

    2014-01-01

    Macroscopic gelatinous colonies of freshwater cyanobacterium Aphanothece sacrum, a luxury ingredient for Japanese cuisine, were found to contain a new oxylipin-derived macrolide, sacrolide A (1), as an antimicrobial component. The configuration of two chiral centers in 1 was determined by a combination of chiral anisotropy analysis and conformational analysis of different ring-opened derivatives. Compound 1 inhibited the growth of some species of Gram-positive bacteria, yeast Saccharomyces cerevisiae and fungus Penicillium chrysogenum, and was also cytotoxic to 3Y1 rat fibroblasts. Concern about potential food intoxication caused by accidental massive ingestion of A. sacrum was dispelled by the absence of 1 in commercial products. A manual procedure for degrading 1 in raw colonies was also developed, enabling a convenient on-site detoxification at restaurants or for personal consumption.

  15. Soft X-ray imaging of cellular carbon and nitrogen distributions in heterocystous cyanobacterium.

    Science.gov (United States)

    Teramoto, Takahiro; Azai, Chihiro; Terauchi, Kazuki; Yoshimura, Masashi; Ohta, Toshiaki

    2018-03-26

    Soft X-ray microscopy (SXM) is a minimally invasive technique for single-cell high-resolution imaging, as well as the visualization of intracellular distributions of light elements such as carbon, nitrogen and oxygen. We used SXM to observe photosynthesis and nitrogen-fixation in the filamentous cyanobacterium Anabaena sp. PCC 7120, which can form heterocysts during nitrogen starvation. Statistical and spectroscopic analyses from soft X-ray microscopic images around the K-absorption edge of nitrogen revealed a significant difference in the carbon-to-nitrogen (C/N) ratio between vegetative cells and heterocysts. Application of this analysis to soft X-ray images of Anabaena revealed inhomogeneous C/N ratios in the cells. Furthermore, soft X-ray tomography of Anabaena revealed differing cellular C/N ratios, indicating different C and N distributions between vegetative cells and heterocysts in three dimensions. {copyright, serif} 2018 American Society of Plant Biologists. All rights reserved.

  16. Natural products chemistry and taxonomy of the marine cyanobacterium Blennothrix cantharidosmum.

    Science.gov (United States)

    Clark, Benjamin R; Engene, Niclas; Teasdale, Margaret E; Rowley, David C; Matainaho, Teatulohi; Valeriote, Frederick A; Gerwick, William H

    2008-09-01

    A Papua New Guinea field collection of the marine cyanobacterium Blennothrix cantharidosmum was investigated for its cytotoxic constituents. Bioassay-guided isolation defined the cytotoxic components as the known compounds lyngbyastatins 1 and 3. However, six new acyl proline derivatives, tumonoic acids D-I, plus the known tumonoic acid A were also isolated. Their planar structures were defined from NMR and MS data, while their stereostructures followed from a series of chiral chromatographies, degradation sequences, and synthetic approaches. The new compounds were tested in an array of assays, but showed only modest antimalarial and inhibition of quorum sensing activities. Nevertheless, these are the first natural products to be reported from this genus, and this inspired a detailed morphologic and 16S rDNA-based phylogenetic analysis of the producing organism.

  17. Synthetic biology toolbox for controlling gene expression in the cyanobacterium Synechococcus sp. strain PCC 7002.

    Science.gov (United States)

    Markley, Andrew L; Begemann, Matthew B; Clarke, Ryan E; Gordon, Gina C; Pfleger, Brian F

    2015-05-15

    The application of synthetic biology requires characterized tools to precisely control gene expression. This toolbox of genetic parts previously did not exist for the industrially promising cyanobacterium, Synechococcus sp. strain PCC 7002. To address this gap, two orthogonal constitutive promoter libraries, one based on a cyanobacterial promoter and the other ported from Escherichia coli, were built and tested in PCC 7002. The libraries demonstrated 3 and 2.5 log dynamic ranges, respectively, but correlated poorly with E. coli expression levels. These promoter libraries were then combined to create and optimize a series of IPTG inducible cassettes. The resultant induction system had a 48-fold dynamic range and was shown to out-perform Ptrc constructs. Finally, a RBS library was designed and tested in PCC 7002. The presented synthetic biology toolbox will enable accelerated engineering of PCC 7002.

  18. Molecular cloning of a recA-like gene from the cyanobacterium Anabaena variabilis

    International Nuclear Information System (INIS)

    Owttrim, G.W.; Coleman, J.R.

    1987-01-01

    A recA-like gene isolated from the cyanobacterium Anabaena variabilis was cloned and partially characterized. When introduced into Escherichia coli recA mutants, the 7.5-kilobase-pair plasmid-borne DNA insert restored resistance to methyl methanesulfonate and UV irradiation, as well as recombination proficiency when measured by Hfr-mediated conjugation. The cyanobacterial recA gene restored spontaneous but not mitomycin C-induced prophage production. Restriction analysis and subcloning yielded a 1.5-kilobase-pair Sau3A fragment which also restored methylmethane sulfonate resistance and coded for a 38- to 40-kilodalton polypeptide when expressed in an in vitro transcription-translation system

  19. Heterologous expression of an algal hydrogenase in a hetero-cystous cyanobacterium

    International Nuclear Information System (INIS)

    Thorsten Heidorn; Peter Lindblad

    2006-01-01

    For the expression of an active algal [FeFe] hydrogenase in the hetero-cystous cyanobacterium Nostoc punctiforme A TCC 29133 the Chlamydomonas reinhardtii hydrogenase gene hydA1 and the accessory genes hydEF and hydG are to be introduced into the cyano-bacterial cells. The genes were amplified by PCR from EST clones, cloned into the cloning vector pBluescript SK+ and sequenced. An expression vector for multi-cistronic cloning, based on pSCR202, was constructed and for a functional test GFP was inserted as a reporter gene. The GFP construct was transformed into Nostoc punctiforme A TCC 29133 by electroporation and expression of GFP was visualized by fluorescence microscopy. (authors)

  20. Genetic Basis for Geosmin Production by the Water Bloom-Forming Cyanobacterium, Anabaena ucrainica

    Directory of Open Access Journals (Sweden)

    Zhongjie Wang

    2014-12-01

    Full Text Available Geosmin is a common, musty-smelling sesquiterpene, principally produced by cyanobacteria. Anabaena ucrainica (Schhorb. Watanabe, a water bloom-forming cyanobacterium, is the geosmin producer responsible for odor problems in Dianchi and Erhai lakes in China. In this study, the geosmin synthase gene (geo of A. ucrainica and its flanking regions were identified and cloned by polymerase chain reaction (PCR and genome walking. The geo gene was found to be located in a transcription unit with two cyclic nucleotide-binding protein genes (cnb. The two cnb genes were highly similar and were predicted members of the cyclic adenosine monophosphate (cAMP receptor protein/fumarate nitrate reductase regulator (Crp–Fnr family. Phylogenetic and evolutionary analyses implied that the evolution of the geosmin genes involved a horizontal gene transfer process in cyanobacteria. These genes showed a close relationship to 2-methylisoborneol genes in origin and evolution.

  1. Engineering of photosynthetic mannitol biosynthesis from CO2 in a cyanobacterium

    DEFF Research Database (Denmark)

    Jacobsen, Jacob Hedemand; Frigaard, Niels-Ulrik

    2014-01-01

    d-Mannitol (hereafter denoted mannitol) is used in the medical and food industry and is currently produced commercially by chemical hydrogenation of fructose or by extraction from seaweed. Here, the marine cyanobacterium Synechococcus sp. PCC 7002 was genetically modified to photosynthetically pr...... concentration of 1.1gmannitolL(-1) and a production rate of 0.15gmannitolL(-1)day(-1). This system may be useful for biosynthesis of valuable sugars and sugar derivatives from CO2 in cyanobacteria....... dry weight in cell cultures deficient in glycogen synthesis; in both cases about 75% of the mannitol was released from the cells into the culture medium by an unknown mechanism. The highest productivity was obtained in a glycogen synthase deficient culture that after 12 days showed a mannitol...

  2. Enhanced production of biomass, pigments and antioxidant capacity of a nutritionally important cyanobacterium Nostochopsis lobatus.

    Science.gov (United States)

    Pandey, Usha; Pandey, J

    2008-07-01

    A diazotrophic cyanobacterium Nostochopsis lobatus was evaluated for enhanced production of biomass, pigments and antioxidant capacity. N. lobatus showed potentially high antioxidant capacity (46.12 microM AEAC) with significant improvement under immobilized cell cultures (87.05 microM AEAC). When a mixture of P and Fe was supplemented, biomass, pigments, nutritive value and antioxidant capacity increased substantially at pH 7.8. When considered separately, P appeared to be a better supplement than Fe for the production of biomass, chlorophyll and carotenoids. However, for phycocyanin, phycoerythrin, nutritive value and antioxidant capacity, Fe appeared more effective than P. Our study indicates N. lobatus to be a promising bioresource for enhanced production of nutritionally rich biomass, pigments and antioxidants. The study also suggests that P and Fe are potentially effective supplements for scale-up production for commercial application.

  3. The complex effects of ocean acidification on the prominent N2-fixing cyanobacterium Trichodesmium.

    Science.gov (United States)

    Hong, Haizheng; Shen, Rong; Zhang, Futing; Wen, Zuozhu; Chang, Siwei; Lin, Wenfang; Kranz, Sven A; Luo, Ya-Wei; Kao, Shuh-Ji; Morel, François M M; Shi, Dalin

    2017-05-05

    Acidification of seawater caused by anthropogenic carbon dioxide (CO 2 ) is anticipated to influence the growth of dinitrogen (N 2 )-fixing phytoplankton, which contribute a large fraction of primary production in the tropical and subtropical ocean. We found that growth and N 2 -fixation of the ubiquitous cyanobacterium Trichodesmium decreased under acidified conditions, notwithstanding a beneficial effect of high CO 2 Acidification resulted in low cytosolic pH and reduced N 2 -fixation rates despite elevated nitrogenase concentrations. Low cytosolic pH required increased proton pumping across the thylakoid membrane and elevated adenosine triphosphate production. These requirements were not satisfied under field or experimental iron-limiting conditions, which greatly amplified the negative effect of acidification. Copyright © 2017, American Association for the Advancement of Science.

  4. Sacrolide A, a new antimicrobial and cytotoxic oxylipin macrolide from the edible cyanobacterium Aphanothece sacrum

    Directory of Open Access Journals (Sweden)

    Naoya Oku

    2014-08-01

    Full Text Available Macroscopic gelatinous colonies of freshwater cyanobacterium Aphanothece sacrum, a luxury ingredient for Japanese cuisine, were found to contain a new oxylipin-derived macrolide, sacrolide A (1, as an antimicrobial component. The configuration of two chiral centers in 1 was determined by a combination of chiral anisotropy analysis and conformational analysis of different ring-opened derivatives. Compound 1 inhibited the growth of some species of Gram-positive bacteria, yeast Saccharomyces cerevisiae and fungus Penicillium chrysogenum, and was also cytotoxic to 3Y1 rat fibroblasts. Concern about potential food intoxication caused by accidental massive ingestion of A. sacrum was dispelled by the absence of 1 in commercial products. A manual procedure for degrading 1 in raw colonies was also developed, enabling a convenient on-site detoxification at restaurants or for personal consumption.

  5. Flocculation properties of several microalgae and a cyanobacterium species during ferric chloride, chitosan and alkaline flocculation.

    Science.gov (United States)

    Lama, Sanjaya; Muylaert, Koenraad; Karki, Tika Bahadur; Foubert, Imogen; Henderson, Rita K; Vandamme, Dries

    2016-11-01

    Flocculation holds great potential as a low-cost harvesting method for microalgae biomass production. Three flocculation methods (ferric chloride, chitosan, and alkaline flocculation) were compared in this study for the harvesting of 9 different freshwater and marine microalgae and one cyanobacterium species. Ferric chloride resulted in a separation efficiency greater than 90% with a concentration factor (CF) higher than 10 for all species. Chitosan flocculation worked generally very well for freshwater microalgae, but not for marine species. Alkaline flocculation was most efficient for harvesting of Nannochloropsis, Chlamydomonas and Chlorella sp. The concentration factor was highly variable between microalgae species. Generally, minimum flocculant dosages were highly variable across species, which shows that flocculation may be a good harvesting method for some species but not for others. This study shows that microalgae and cyanobacteria species should not be selected solely based on their productivity but also on their potential for low-cost separation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Evaluation of antiplasmodial properties of a cyanobacterium, Spirulina platensis and its mechanism of action.

    Science.gov (United States)

    Wulandari, Diah Anggraini; Sidhartha, Elizabeth; Setyaningsih, Iriani; Marbun, Jonathan Marshall; Syafruddin, Din; Asih, Puji Budi Setia

    2017-08-02

    The rapid emergence of antimalarial drug resistance necessitates a continual effort on novel drug discovery. A cyanobacterium, Spirulina platensis, is a potential antimalarial agent that has been widely consumed as food supplement in the form of crude extract. It is known to possess antiviral, antibacterial and antifungi activities. This study examined the antimalarial activities of several Spirulina formulas against Plasmodium falciparum 3D7, in vitro. The tested Spirulina formulas included commercially available capsule, crude extract and alkaloid fraction. Results showed that all tested formula possessed antimalarial activities with the Spirulina capsule exhibited the highest activities (IC 50  = 2.16 μg/mL). Light and electron microscopies revealed interference of the Spirulina with the parasite hemozoin formation. In conclusion, all tested Spirulina formulas and fraction exhibited moderate to high antimalarial activities.

  7. Differences in energy transfer of a cyanobacterium, Synechococcus sp. PCC 7002, grown in different cultivation media.

    Science.gov (United States)

    Niki, Kenta; Aikawa, Shimpei; Yokono, Makio; Kondo, Akihiko; Akimoto, Seiji

    2015-08-01

    Currently, cyanobacteria are regarded as potential biofuel sources. Large-scale cultivation of cyanobacteria in seawater is of particular interest because seawater is a low-cost medium. In the present study, we examined differences in light-harvesting and energy transfer processes in the cyanobacterium Synechococcus sp. PCC 7002 grown in different cultivation media, namely modified A medium (the optimal growth medium for Synechococcus sp. PCC 7002) and f/2 (a seawater medium). The concentrations of nitrate and phosphate ions were varied in both media. Higher nitrate ion and/or phosphate ion concentrations yielded high relative content of phycobilisome. The cultivation medium influenced the energy transfers within phycobilisome, from phycobilisome to photosystems, within photosystem II, and from photosystem II to photosystem I. We suggest that the medium also affects charge recombination at the photosystem II reaction center and formation of a chlorophyll-containing complex.

  8. Transcriptomic Analysis and Microscopic Observations in the Cyanobacterium UCYN-A during Diel Cycles

    Science.gov (United States)

    Muñoz-Marin, M. D. C.; Farnelid, H.; Zehr, J. P.

    2016-02-01

    Candidatus Atelocyanobacterium thalassa (UCYN-A) is a nitrogen-fixing marine cyanobacterium recently recognized for its widespread distribution and significant contributions to oceanic nitrogen (N2)-fixation. UCYN-A is a group of related cyanobacteria that are symbiotic with a single-celled eukaryotic phytoplankter, the haptophyte Braarudosphaera bigelowii. UCYN-A fixes N2 and expresses nitrogenase during the day. Since the nitrogenase is inactivated by oxygen evolved through photosynthesis, most cyanobacteria use temporal or spatial separation of photosynthesis and N2 fixation. Genomic studies revealed that UCYN-A lacks the entire PSII apparatus (photosystem II). The lack of oxygenic photosynthesis at least partially explains why they can fix nitrogen during the day, although the host is a photoautotroph. However, UCYN-A has retained photosystem I (PSI), and PSI activity may be important in the energetics of N2 fixation in the symbiosis. Because UCYN-A lacks photosystem II, which normally supplies electrons to photosystem I from water, UCYN-A needs alternative electron donors if it uses photosystem I to make the reductant NADPH. In order to determine if UCYN-A expresses photosynthetic genes and which other proteins may be involved with energy metabolism, we developed a whole genome array to examine gene transcription over the diel cycle in two strains. Our results show that there is a temporal separation of the expression of photosynthesis genes from the expression of nitrogenase genes. Moreover, the transcription profile of NADH dehydrogenases and hydrogenases suggest they may be involved as alternative electron donors for the N2 fixation. In addition, we used a double-CARD-FISH (Catalyzed Reporter Deposition-Fluorescence in situ Hybridization) assay to study cell division of the host and symbiont during diel cycles in relation to UCYN-A gene expression carried out during the transcriptomic analysis. These results help us move toward a deeper understanding of the

  9. Isolation and Purification of Heterotetrameric Catalase from a Desiccation Tolerant Cyanobacterium Lyngbya arboricola

    Directory of Open Access Journals (Sweden)

    Kapoor, Shivali

    2013-02-01

    Full Text Available The desiccation tolerant cyanobacterium Lyngbya arboricola, isolated from bark surfaces of Mangifera indica, possessed up to four stable isoforms of catalase in addition to other antioxidative enzymes, for several years under a dry state. Purification of the two most persistent isoforms of catalase (Cat has been undertaken by employing acetone precipitation, ethanol: chloroform treatment, gel filtration and ion exchange chromatography. The two isoforms of catalase remained almost unchanged on varying matric and osmotic hydration levels of mats of the cyanobacterium. The purification procedures resulted in a 1.3 % yield of purified single isoform (0.22 mg mL-1 protein with 709 Units mg-1 specific activity and a purity index of 0.83. Five millimolar of dithiothreitol (DTT was observed to be pertinent in maintaining the optimum redox state of the enzyme. The purification procedures additionally facilitated the simultaneous elimination and procurement of phycoerythrins (PE and mycosporine-like amino acids (MAA. Each purified isoform gave a single band (~45kDa upon SDS-PAGE and denaturing urea isoelectric focusing (IEF depicted the presence of 2 subunits each of CatA and CatB. The monoisotopic mass and pI value of CatA and CatB as revealed by LC-MS analysis and internal amino acid sequencing was 78.96, 5.89 and 80.77, 5.92, respectively, showing resemblance with CatA of Erysiphe graminis subs. hordei and CatB of Ajellomyces capsulata. The heterotetrameric monofunctional catalase (~320 kDa, due to its stability in the form of resistance to ethanol: chloroform, its thermoalkaliphilic nature and the presence of innumerable hydrophobic amino acid residues (~40%, thus exhibited its potential for biotechnological applications.

  10. Cellular responses and bioremoval of nonylphenol by the bloom-forming cyanobacterium Planktothrix agardhii 1113

    Science.gov (United States)

    Medvedeva, Nadezda; Zaytseva, Tatyana; Kuzikova, Irina

    2017-07-01

    Nonylphenol (NP) is extensively used in agricultural, industrial and household applications. Moreover, NP is the major breakdown product of the nonionic surfactants, nonylphenol ethoxylates (NPEOs), the most widely used group of surfactants. Nonylphenol is persistent in the environment, highly toxic to aquatic organisms and is a potential endocrine disruptor. NP and NPEOs have been identified as priority hazardous substances under the Environmental Quality Standards Directive 2013/39/EU and are referred to in the list of substances of particular risk to the Baltic Sea. The toxicity of NP to the bloom-forming cyanobacterium Planktothrix agardhii 1113 isolated from the eastern Gulf of Finland, Baltic Sea and the bioremoval of NP by P. agardhii were studied. NP in concentrations > 0.4 mg L- 1 suppressed cyanobacterial growth. The median effective concentration of NP for P. agardhii after 4 days of treatment (EC50) was 1.5 mg L- 1. The removal of NP from the culture medium was primarily due to abiotic processes and biodegradation by the cyanobacterium rather than sorption by the cells. NP significantly increased the photosynthetic pigments, extracellular proteins and soluble exopolysaccharides content. The cyanobacterial growth inhibition was accompanied by the increased synthesis of microcystin dm-RR and of the odorous metabolites, geosmin and 2-methylisoborneol (MIB), by P. agardhii 1113. NP also notably increased the microcystin released into the environment. Increased levels of extracellular proteins, soluble exopolysaccharides, microcystins and odorous metabolites may affect the microbial loop in aquatic ecosystems. An increased level of malondialdehyde (MDA) was indicative of the formation of free radicals in P. agardhii under NP stress, whereas increased levels of superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH) and proline indicated the occurrence of a scavenging mechanism.

  11. Cyanobacterial carbon metabolism: Fluxome plasticity and oxygen dependence.

    Science.gov (United States)

    Wan, Ni; DeLorenzo, Drew M; He, Lian; You, Le; Immethun, Cheryl M; Wang, George; Baidoo, Edward E K; Hollinshead, Whitney; Keasling, Jay D; Moon, Tae Seok; Tang, Yinjie J

    2017-07-01

    Synechocystis sp. strain PCC 6803 has been widely used as a photo-biorefinery chassis. Based on its genome annotation, this species contains a complete TCA cycle, an Embden-Meyerhof-Parnas pathway (EMPP), an oxidative pentose phosphate pathway (OPPP), and an Entner-Doudoroff pathway (EDP). To evaluate how Synechocystis 6803 catabolizes glucose under heterotrophic conditions, we performed 13 C metabolic flux analysis, metabolite pool size analysis, gene knockouts, and heterologous expressions. The results revealed a cyclic mode of flux through the OPPP. Small, but non-zero, fluxes were observed through the TCA cycle and the malic shunt. Independent knockouts of 6-phosphogluconate dehydrogenase (gnd) and malic enzyme (me) corroborated these results, as neither mutant could grow under dark heterotrophic conditions. Our data also indicate that Synechocystis 6803 metabolism relies upon oxidative phosphorylation to generate ATP from NADPH under dark or insufficient light conditions. The pool sizes of intermediates in the TCA cycle, particularly acetyl-CoA, were found to be several fold lower in Synechocystis 6803 (compared to E. coli metabolite pool sizes), while its sugar phosphate intermediates were several-fold higher. Moreover, negligible flux was detected through the native, or heterologous, EDP in the wild type or Δgnd strains under heterotrophic conditions. Comparing photoautotrophic, photomixotrophic, and heterotrophic conditions, the Calvin cycle, OPPP, and EMPP in Synechocystis 6803 possess the ability to regulate their fluxes under various growth conditions (plastic), whereas its TCA cycle always maintains at low levels (rigid). This work also demonstrates how genetic profiles do not always reflect actual metabolic flux through native or heterologous pathways. Biotechnol. Bioeng. 2017;114: 1593-1602. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  12. Cyanobacterial carbon metabolism: Fluxome plasticity and oxygen dependence: Cyanobacterial Carbon Metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Ni [Washington Univ., St. Louis, MO (United States); DeLorenzo, Drew M. [Washington Univ., St. Louis, MO (United States); He, Lian [Washington Univ., St. Louis, MO (United States); You, Le [Washington Univ., St. Louis, MO (United States); Immethun, Cheryl M. [Washington Univ., St. Louis, MO (United States); Wang, George [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Baidoo, Edward E. K. [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hollinshead, Whitney [Washington Univ., St. Louis, MO (United States); Keasling, Jay D. [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Technical Univ. of Denmark, Lyngby (Denmark); Moon, Tae Seok [Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis Missouri 63130; Tang, Yinjie J. [Washington Univ., St. Louis, MO (United States)

    2017-03-30

    Synechocystis sp. strain PCC 6803 has been widely used as a photo-biorefinery chassis. Based on its genome annotation, this species contains a complete TCA cycle, an Embden-Meyerhof-Parnas pathway (EMPP), an oxidative pentose phosphate pathway (OPPP), and an Entner–Doudoroff pathway (EDP). To evaluate how Synechocystis 6803 catabolizes glucose under heterotrophic conditions, we performed 13C metabolic flux analysis, metabolite pool size analysis, gene knockouts, and heterologous expressions. The results revealed a cyclic mode of flux through the OPPP. Small, but non-zero, fluxes were observed through the TCA cycle and the malic shunt. Independent knockouts of 6-phosphogluconate dehydrogenase (gnd) and malic enzyme (me) corroborated these results, as neither mutant could grow under dark heterotrophic conditions. Our data also indicate that Synechocystis 6803 metabolism relies upon oxidative phosphorylation to generate ATP from NADPH under dark or insufficient light conditions. The pool sizes of intermediates in the TCA cycle, particularly acetyl-CoA, were found to be several fold lower in Synechocystis 6803 (compared to E. coli metabolite pool sizes), while its sugar phosphate intermediates were several-fold higher. Moreover, negligible flux was detected through the native, or heterologous, EDP in the wild type or Δgnd strains under heterotrophic conditions. Comparing photoautotrophic, photomixotrophic, and heterotrophic conditions, the Calvin cycle, OPPP, and EMPP in Synechocystis 6803 possess the ability to regulate their fluxes under various growth conditions (plastic), whereas its TCA cycle always maintains at low levels (rigid). This work also demonstrates how genetic profiles do not always reflect actual metabolic flux through native or heterologous pathways. Biotechnol. Bioeng. 2017;114: 1593–1602. © 2017 Wiley Periodicals, Inc.

  13. Adaptation Reactions of Siderophilic Cyanobacteria to High and Low Levels Of Environmental Iron: Implications for Biosphere History

    Science.gov (United States)

    Brown, I. I.; Bryant, D.; Sarkisova, S.; Shen, G.; Garrison, D.; McKay, D. S.

    2009-01-01

    Of all extant environments, iron-depositing hot springs may constitute the most appropriate natural models (Pierson and Parenteau, 2000) for analysis of the ecophysiology of ancient cyanobacteria (CB) which may have emerged in association with hydrothermal activity (Brown et al., 2007) and elevated levels of environmental Fe (Rouxel et al., 2005). Elevated environmental Fe2+ posed a significant challenge to the first oxygenic phototrophs - CB - because reduced Fe2+ induces toxic Fenton reactions (Wiedenheft et al., 2005). Ancient CB could have also been stressed by occasional migrations from the Fe2+-rich Ocean to the basaltic land which was almost devoid of dissolved Fe2+. That is why the study of the adaptation reactions of siderophilic CB, which inhabit iron-depositing hot springs, to up and down shifts in levels of dissolved Fe may shed light on the paleophysiology of ancient oxygenic prokaryotes. Methods. Siderophilic CB (Brown et al., 2007) were cultivated in media with different concentrations of added Fe3+. In some cases basaltic rocks were used as a source of Fe and trace elements. The processes of Fe mineralization and rock dissolution were studied using TEM, SEM and EDS techniques. Fluorescence spectroscopy was used for checking chlorophyll-protein complexes. Results. It was found that five siderophilic isolates Chroogloeocystis siderophila, JSC-1, JSC-3, JSC-11 and JSC-12 precipitated Fe-bearing phases on the exopolymeric sheaths of their cells if [Fe3+] was approx. 400-600 M (high Fe). Same [Fe3+] was most optimal one for the cultures proliferation rate (Brown et al., 2005; Brown et al., 2007). Higher concentrations of Fe3+ repressed the growth of some siderophilic CB (Brown et al., 2005). No mineralized Fe3+ was observed on the sheath of freshwater isolates Synechocystis sp. PCC 6803 and Phormidium aa. Scanning TEM in conjunction with thin-window energy dispersive X-ray spectroscopy (EDS) revealed intracellular Fe-rich phases within all three isolates

  14. Cyanobacteria from the Baltic Sea and Finnish lakes as an energy source and modulators of bioenergetic pathways

    Energy Technology Data Exchange (ETDEWEB)

    Sumathy, S.

    2012-11-01

    Cyanobacteria are a diverse group of oxygenic photosynthetic bacteria that inhabit in a wide range of environments. They are versatile and multifaceted organisms with great possibilities for different biotechnological applications. For example, cyanobacteria produce molecular hydrogen (H{sub 2}), which is one of the most important alternatives for clean and sustainable energy. Apart from being beneficial, cyanobacteria also possess harmful characteristics and may become a source of threat to human health and other living organisms, as they are able to form surface blooms that are producing a variety of toxic or bioactive compounds. The University of Helsinki Culture Collection (UHCC) maintains around 1,000 cyanobacterial strains representing a large number of genera and species isolated from the Baltic Sea and Finnish lakes. The culture collection covers different life forms such as unicellular and filamentous, N{sub 2}-fixing and non-N{sub 2}-fixing strains, and planktonic and benthic cyanobacteria. In this thesis, the UHCC has been screened to identify potential strains for sustainable biohydrogen production and also for strains that produce compounds modifying the bioenergetic pathways of other cyanobacteria or terrestrial plants. Among the 400 cyanobacterial strains screened so far, ten were identified as high H{sub 2}- producing strains. The enzyme systems involved in H2 metabolism of cyanobacteria were analyzed using the Southern hybridization approach. This revealed the presence of the enzyme nitrogenase in all strains tested, while none of them are likely to have contained alternative nitrogenases. All the strains tested, except for two Calothrix strains, XSPORK 36C and XSPORK 11A, were suggested to contain both uptake and bidirectional hydrogenases. Moreover, 55 methanol extracts of various cyanobacterial strains were screened to identify potent bioactive compounds affecting the photosynthetic apparatus of the model cyanobacterium, Synechocystis PCC 6803

  15. Participation of Glutamate-354 of the CP43 Polypeptide in the Ligation of Mn and the Binding of Substrate Water in Photosystem II

    Energy Technology Data Exchange (ETDEWEB)

    Service, Rachel; Yano, Junko; McConnell, Iain; Hwang, Hong Jin; Niks, Dimitri; Hille, Russ; Wydrzynski, Tom; Burnap, Robert; Hillier, Warwick; Debus, Richard

    2010-09-30

    In the current X-ray crystallographic structural models of photosystem II, Glu354 of the CP43 polypeptide is the only amino acid ligand of the oxygen-evolving Mn4Ca cluster that is not provided by the D1 polypeptide. To further explore the influence of this structurally unique residue on the properties of the Mn4Ca cluster, the CP43-E354Q mutant of the cyanobacterium Synechocystis sp. PCC 6803 was characterized with a variety of biophysical and spectroscopic methods, including polarography, EPR, X-ray Absorption, FTIR, and mass spectrometry. The kinetics of oxygen release in the mutant were essentially unchanged from those in wild-type. In addition, the oxygen flash-yields exhibited normal period-four oscillations having normal S state parameters, although the yields were lower, correlating with the mutant?s lower steady-state rate (approx. 20percent compared to wild-type). Experiments conducted with H218O showed that the fast and slow phases of substrate water exchange in CP43-E354Q thylakoid membranes were accelerated 8.5- and 1.8-fold, respectively, in the S3 state compared to wild-type. Purified oxygen-evolving CP43-E354Q PSII core complexes exhibited a slightly altered S1 state Mn-EXAFS spectrum, a slightly altered S2 state multiline EPR signal, a substantially altered S2-minus-S1 FTIR difference spectrum, and an unusually long lifetime for the S2 state (> 10 hours) in a substantial fraction of reaction centers. In contrast, the S2 state Mn-EXAFS spectrum was nearly indistinguishable from that of wild-type. The S2-minus-S1 FTIR difference spectrum showed alterations throughout the amide and carboxylate stretching regions. Global labeling with 15N and specific labeling with L-[1-13C]alanine revealed that the mutation perturbs both amide II and carboxylate stretching modes and shifts the symmetric carboxylate stretching modes of the ?-COO? group of D1-Ala344 (the C-terminus of the D1 polypeptide) to higher frequencies by 3 ? 4 cm-1 in both the S1 and S2 states

  16. Backbone dynamics of reduced plastocyanin from the cyanobacterium Anabaena variabilis: Regions involved in electron transfer have enhanced mobility

    DEFF Research Database (Denmark)

    Ma, L.X.; Hass, M.A.S.; Vierick, N.

    2003-01-01

    The dynamics of the backbone of the electron-transfer protein plastocyanin from the cyanobacterium Anabaena variabilis were determined from the N-15 and C-13(alpha) R-1 and R-2) relaxation rates and steady-state [H-1]-N-15 and [H-1]-C-13 nuclear Overhauser effects (NOEs) using the model-free appr......The dynamics of the backbone of the electron-transfer protein plastocyanin from the cyanobacterium Anabaena variabilis were determined from the N-15 and C-13(alpha) R-1 and R-2) relaxation rates and steady-state [H-1]-N-15 and [H-1]-C-13 nuclear Overhauser effects (NOEs) using the model...... are the "northern" hydrophobic site close to the metal site, the metal site itself, and the "eastern" face of the molecule. In particular, the mobility of the latter region is interesting in light of recent findings indicating that residues also on the eastern face of plastocyanins from prokaryotes are important...

  17. Resistance to the photosystem II herbicide diuron is dominant to sensitivity in the cyanobacterium Synechococcus sp. PCC7942

    OpenAIRE

    Brusslan, Judy; Haselkorn, Robert

    1989-01-01

    The transformable cyanobacterium, Synechococcus sp. PCC7942, was used to study the genetics of resistance to the herbicide diuron. In wild-type cells, diuron binds to one of the core proteins, called D1, of photosystem II reaction centres. This binding prevents the transfer of electrons from QA, the primary quinone acceptor, to QB, which is necessary to create the charge separation that drives ATP synthesis. A single amino acid substitution in the D1 protein reduces diuron binding and confers...

  18. Processing recommendations for using low-solids digestate as nutrient solution for poly-ß-hydroxybutyrate production with Synechocystis salina.

    Science.gov (United States)

    Meixner, K; Fritz, I; Daffert, C; Markl, K; Fuchs, W; Drosg, B

    2016-12-20

    Within the last decades, environmental pollution with persistent plastics steadily increased; therefore the production of biodegradable materials like poly-ß-hydroxybutyrate (PHB) is essential. Currently, PHB is produced with heterotrophic bacteria from crops. This leads to competition with food and feed production, which can be avoided by using photoautotrophic cyanobacteria, as Synechocystis salina, synthesizing PHB from CO 2 at nutrient limitation. This study aims to increase the economic efficiency of PHB production with cyanobacteria by using nutrients from anaerobic digestate. First, growth and PHB production of S. salina in digestate fractions (supernatant and permeate, with/without precipitating agents) and dilutions thereof and then the scale-up (photobioreactor, 200 L working volume) were evaluated. With precipitated and centrifuged digestate diluted 1/3 the highest biomass (1.55gL -1 ) and PHB concentrations (95.4mgL -1 ), being 78% of those in mineral media, were achieved. In the photobioreactor-experiments biomass (1.63gL -1 ) and PHB concentrations (88.7mgL -1 ), being 79% and 72% of those in mineral medium, were reached, but in a cultivation time 10days longer than in mineral medium. The possibility to use digestate as sustainable and low cost nutrient solution for microalgae cultivation and photoautotrophic PHB production, instead of applying it on fields or processing it to achieve discharge limits, makes this application a highly valid option. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Synechocystis DrgA protein functioning as nitroreductase and ferric reductase is capable of catalyzing the Fenton reaction.

    Science.gov (United States)

    Takeda, Kouji; Iizuka, Mayumi; Watanabe, Toshihiro; Nakagawa, Junichi; Kawasaki, Shinji; Niimura, Youichi

    2007-03-01

    In order to identify an enzyme capable of Fenton reaction in Synechocystis, we purified an enzyme catalyzing one-electron reduction of t-butyl hydroperoxide in the presence of FAD and Fe(III)-EDTA. The enzyme was a 26 kDa protein, and its N-terminal amino acid sequencing revealed it to be DrgA protein previously reported as quinone reductase [Matsuo M, Endo T and Asada K (1998) Plant Cell Physiol39, 751-755]. The DrgA protein exhibited potent quinone reductase activity and, furthermore, we newly found that it contained FMN and highly catalyzed nitroreductase, flavin reductase and ferric reductase activities. This is the first demonstration of nitroreductase activity of DrgA protein previously identified by a drgA mutant phenotype. DrgA protein strongly catalyzed the Fenton reaction in the presence of synthetic chelate compounds, but did so poorly in the presence of natural chelate compounds. Its ferric reductase activity was observed with both natural and synthetic chelate compounds with a better efficiency with the latter. In addition to small molecular-weight chemical chelators, an iron transporter protein, transferrin, and an iron storage protein, ferritin, turned out to be substrates of the DrgA protein, suggesting it might play a role in iron metabolism under physiological conditions and possibly catalyze the Fenton reaction under hyper-reductive conditions in this microorganism.

  20. Effects of Cylindrospermopsin Producing Cyanobacterium and Its Crude Extracts on a Benthic Green Alga—Competition or Allelopathy?

    Directory of Open Access Journals (Sweden)

    Viktória B-Béres

    2015-10-01

    Full Text Available Cylindrospermopsin (CYN is a toxic secondary metabolite produced by filamentous cyanobacteria which could work as an allelopathic substance, although its ecological role in cyanobacterial-algal assemblages is mostly unclear. The competition between the CYN-producing cyanobacterium Chrysosporum (Aphanizomenon ovalisporum, and the benthic green alga Chlorococcum sp. was investigated in mixed cultures, and the effects of CYN-containing cyanobacterial crude extract on Chlorococcum sp. were tested by treatments with crude extracts containing total cell debris, and with cell debris free crude extracts, modelling the collapse of a cyanobacterial water bloom. The growth inhibition of Chlorococcum sp. increased with the increasing ratio of the cyanobacterium in mixed cultures (inhibition ranged from 26% to 87% compared to control. Interestingly, inhibition of the cyanobacterium growth also occurred in mixed cultures, and it was more pronounced than it was expected. The inhibitory effects of cyanobacterial crude extracts on Chlorococcum cultures were concentration-dependent. The presence of C. ovalisporum in mixed cultures did not cause significant differences in nutrient content compared to Chlorococcum control culture, so the growth inhibition of the green alga could be linked to the presence of CYN and/or other bioactive compounds.

  1. Responses of a rice-field cyanobacterium Anabaena siamensis TISTR-8012 upon exposure to PAR and UV radiation.

    Science.gov (United States)

    Rastogi, Rajesh P; Incharoensakdi, Aran; Madamwar, Datta

    2014-10-15

    The effects of PAR and UV radiation and subsequent responses of certain antioxidant enzymatic and non-enzymatic defense systems were studied in a rice field cyanobacterium Anabaena siamensis TISTR 8012. UV radiation resulted in a decline in growth accompanied by a decrease in chlorophyll a and photosynthetic efficiency. Exposure of cells to UV radiation significantly affected the differentiation of vegetative cells into heterocysts or akinetes. UV-B radiation caused the fragmentation of the cyanobacterial filaments conceivably due to the observed oxidative stress. A significant increase of reactive oxygen species in vivo and DNA strand breaks were observed in UV-B exposed cells followed by those under UV-A and PAR radiation, respectively. The UV-induced oxidative damage was alleviated due to an induction of antioxidant enzymatic/non-enzymatic defense systems. In response to UV irradiation, the studied cyanobacterium exhibited a significant increase in antioxidative enzyme activities of superoxide dismutase, catalase and peroxidase. Moreover, the cyanobacterium also synthesized some UV-absorbing/screening substances. HPLC coupled with a PDA detector revealed the presence of three compounds with UV-absorption maxima at 326, 331 and 345 nm. The induction of the biosynthesis of these UV-absorbing compounds was found under both PAR and UV radiation, thus suggesting their possible function as an active photoprotectant. Copyright © 2014 Elsevier GmbH. All rights reserved.

  2. Short Communication: Effects of temperature on growth, pigment composition and protein content of an Antarctic Cyanobacterium Nostoc commune

    Directory of Open Access Journals (Sweden)

    RANJANA TRIPATHI

    2012-11-01

    Full Text Available Tripathi R, Dhuldhaj UP, Singh S. 2012. Short Communication: Effects of temperature on growth, pigment composition and protein content of an Antarctic Cyanobacterium Nostoc commune. Nusantara Bioscience 4: 134-137. Effect of temperature variation on biomass accumulation, pigment composition and protein content were studied for the cyanobacterium Nostoc commune, isolated from Antarctica. Results confirmed the psychrotrophic behavior (optimum growth temperature 25◦C of the cyanobacterium. Low temperature increased the duration of lag phase and exponential growth phase. Maximum increase in biomass was recorded on 24th day at 25◦C and on 12th day at 50C. The downshift from 25 to 5◦C had almost negligible effect on chl a content. Maximal protein content was recorded for cultures growing at 50C on 12th day. The carotenoids/chl a ratio was maximum (2.48 at 50C on 9th day. It remained almost constant for cultures growing at 5 and 350C. There was an induction in protein synthesis following downshift in temperature from 25 to 5◦C.

  3. Estimation of the light field inside photosynthetic microorganism cultures through Mittag-Leffler functions at depleted light conditions

    Science.gov (United States)

    Fuente, David; Lizama, Carlos; Urchueguía, Javier F.; Conejero, J. Alberto

    2018-01-01

    Light attenuation within suspensions of photosynthetic microorganisms has been widely described by the Lambert-Beer equation. However, at depths where most of the light has been absorbed by the cells, light decay deviates from the exponential behaviour and shows a lower attenuation than the corresponding from the purely exponential fall. This discrepancy can be modelled through the Mittag-Leffler function, extending Lambert-Beer law via a tuning parameter α that takes into account the attenuation process. In this work, we describe a fractional Lambert-Beer law to estimate light attenuation within cultures of model organism Synechocystis sp. PCC 6803. Indeed, we benchmark the measured light field inside cultures of two different Synechocystis strains, namely the wild-type and the antenna mutant strain called Olive at five different cell densities, with our in silico results. The Mittag-Leffler hyper-parameter α that best fits the data is 0.995, close to the exponential case. One of the most striking results to emerge from this work is that unlike prior literature on the subject, this one provides experimental evidence on the validity of fractional calculus for determining the light field. We show that by applying the fractional Lambert-Beer law for describing light attenuation, we are able to properly model light decay in photosynthetic microorganisms suspensions.

  4. Species-specific roles of sulfolipid metabolism in acclimation of photosynthetic microbes to sulfur-starvation stress.

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    Norihiro Sato

    Full Text Available Photosynthetic organisms utilize sulfate for the synthesis of sulfur-compounds including proteins and a sulfolipid, sulfoquinovosyl diacylglycerol. Upon ambient deficiency in sulfate, cells of a green alga, Chlamydomonas reinhardtii, degrade the chloroplast membrane sulfolipid to ensure an intracellular-sulfur source for necessary protein synthesis. Here, the effects of sulfate-starvation on the sulfolipid stability were investigated in another green alga, Chlorella kessleri, and two cyanobacteria, Synechocystis sp. PCC 6803 and Synechococcus elongatus PCC 7942. The results showed that sulfolipid degradation was induced only in C. kessleri, raising the possibility that this degradation ability was obtained not by cyanobacteria, but by eukaryotic algae during the evolution of photosynthetic organisms. Meanwhile, Synechococcus disruptants concerning sqdB and sqdX genes, which are involved in successive reactions in the sulfolipid synthesis pathway, were respectively characterized in cellular response to sulfate-starvation. Phycobilisome degradation intrinsic to Synechococcus, but not to Synechocystis, and cell growth under sulfate-starved conditions were repressed in the sqdB and sqdX disruptants, respectively, relative to in the wild type. Their distinct phenotypes, despite the common loss of the sulfolipid, inferred specific roles of sqdB and sqdX. This study demonstrated that sulfolipid metabolism might have been developed to enable species- or cyanobacterial-strain dependent processes for acclimation to sulfate-starvation.

  5. A phycocyanin·phellandrene synthase fusion enhances recombinant protein expression and β-phellandrene (monoterpene) hydrocarbons production in Synechocystis (cyanobacteria).

    Science.gov (United States)

    Formighieri, Cinzia; Melis, Anastasios

    2015-11-01

    Cyanobacteria can be exploited as photosynthetic platforms for heterologous generation of terpene hydrocarbons with industrial applications. Transformation of Synechocystis and heterologous expression of the β-phellandrene synthase (PHLS) gene alone is necessary and sufficient to confer to Synechocystis the ability to divert intermediate terpenoid metabolites and to generate the monoterpene β-phellandrene during photosynthesis. However, terpene synthases, including the PHLS, have a slow Kcat (low Vmax) necessitating high levels of enzyme concentration to enable meaningful rates and yield of product formation. Here, a novel approach was applied to increase the PHLS protein expression alleviating limitations in the rate and yield of β-phellandrene product generation. Different PHLS fusion constructs were generated with the Synechocystis endogenous cpcB sequence, encoding for the abundant in cyanobacteria phycocyanin β-subunit, expressed under the native cpc operon promoter. In one of these constructs, the CpcB·PHLS fusion protein accumulated to levels approaching 20% of the total cellular protein, i.e., substantially higher than expressing the PHLS protein alone under the same endogenous cpc promoter. The CpcB·PHLS fusion protein retained the activity of the PHLS enzyme and catalyzed β-phellandrene synthesis, yielding an average of 3.2 mg product g(-1) dry cell weight (dcw) versus the 0.03 mg g(-1)dcw measured with low-expressing constructs, i.e., a 100-fold yield improvement. In conclusion, the terpene synthase fusion-protein approach is promising, as, in this case, it substantially increased the amount of the PHLS in cyanobacteria, and commensurately improved rates and yield of β-phellandrene hydrocarbons production in these photosynthetic microorganisms. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  6. Molecular exploration of the highly radiation resistant cyanobacterium Arthrospira sp. PCC 8005

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    Badri, Hanène; Leys, Natalie; Wattiez, Ruddy

    Arthrospira (Spirulina) is a photosynthetic cyanobacterium able to use sunlight to release oxygen from water and remove carbon dioxide and nitrate from water. In addition, it is suited for human consumption (edible). For these traits, the cyanobacterium Arthrospira sp. PCC 8005 was selected by the European Space Agency (ESA) as part of the life support system MELiSSA for recycling oxygen, water, and food during future long-haul space missions. However, during such extended missions, Arthrospira sp. PCC 8005 will be exposed to continuous artificial illumination and harmful cosmic radiation. The aim of this study was to investigate how Arthrospira will react and behave when exposed to such stress environment. The cyanobacterium Arthrospira sp. PCC 8005 was exposed to high gamma rays doses in order to unravel in details the response of this bacterium following such stress. Test results showed that after acute exposure to high doses of 60Co gamma radiation upto 3200 Gy, Arthrospira filaments were still able to restart photosynthesis and proliferate normally. Doses above 3200 Gy, did have a detrimental effect on the cells, and delayed post-irradiation proliferation. The photosystem activity, measured as the PSII quantum yield immediately after irradiation, decreased significantly at radiation doses above 3200 Gy. Likewise through pigment content analysis a significant decrease in phycocyanin was observed following exposure to 3200 Gy. The high tolerance of this bacterium to 60Co gamma rays (i.e. ca. 1000x more resistant than human cells for example) raised our interest to investigate in details the cellular and molecular mechanisms behind this amazing resistance. Optimised DNA, RNA and protein extraction methods and a new microarray chip specific for Arthrospira sp. PCC 8005 were developed to identify the global cellular and molecular response following exposure to 3200 Gy and 5000 Gy A total of 15,29 % and 30,18 % genes were found differentially expressed in RNA

  7. Lab-Scale Study of the Calcium Carbonate Dissolution and Deposition by Marine Cyanobacterium Phormidium subcapitatum

    Science.gov (United States)

    Karakis, S. G.; Dragoeva, E. G.; Lavrenyuk, T. I.; Rogochiy, A.; Gerasimenko, L. M.; McKay, D. S.; Brown, I. I.

    2006-01-01

    Suggestions that calcification in marine organisms changes in response to global variations in seawater chemistry continue to be advanced (Wilkinson, 1979; Degens et al. 1985; Kazmierczak et al. 1986; R. Riding 1992). However, the effect of [Na+] on calcification in marine cyanobacteria has not been discussed in detail although [Na+] fluctuations reflect both temperature and sea-level fluctuations. The goal of these lab-scale studies therefore was to study the effect of environmental pH and [Na+] on CaCO3 deposition and dissolution by marine cyanobacterium Phormidium subcapitatum. Marine cyanobacterium P. subcapitatum has been cultivated in ASN-III medium. [Ca2+] fluctuations were monitored with Ca(2+) probe. Na(+) concentrations were determined by the initial solution chemistry. It was found that the balance between CaCO3 dissolution and precipitation induced by P. subcapitatum grown in neutral ASN III medium is very close to zero. No CaCO3 precipitation induced by cyanobacterial growth occurred. Growth of P. subcapitatum in alkaline ASN III medium, however, was accompanied by significant oscillations in free Ca(2+) concentration within a Na(+) concentration range of 50-400 mM. Calcium carbonate precipitation occurred during the log phase of P. subcapitatum growth while carbonate dissolution was typical for the stationary phase of P. subcapitatum growth. The highest CaCO3 deposition was observed in the range of Na(+) concentrations between 200-400 mM. Alkaline pH also induced the clamping of P. subcapitatum filaments, which appeared to have a strong affinity to envelop particles of chemically deposited CaCO3 followed by enlargement of those particles size. EDS analysis revealed the presence of Mg-rich carbonate (or magnesium calcite) in the solution containing 10-100 mM Na(+); calcite in the solution containing 200 mM Na(+); and aragonite in the solution containing with 400 mM Na(+). Typical present-day seawater contains xxmM Na(+). Early (Archean) seawater was

  8. Light/dark cyclic movement of algal culture (Synechocystis aquatilis) in outdoor inclined tubular photobioreactor equipped with static mixers for efficient production of biomass.

    Science.gov (United States)

    Ugwu, C U; Ogbonna, J C; Tanaka, H

    2005-01-01

    Synechocystis aquatilis SI-2 was grown outdoors in a 12.5 cm diam. tubular photobioreactor equipped with static mixers. The static mixers ensured that cells were efficiently circulated between the upper (illuminated) and lower (dark) sections of the tubes. The biomass productivity varied from 22 to 45 g m-2 d-1, with an average of 35 g m-2 d-1, etc which corresponded to average CO2 fixation rate of about 57 g CO2 m-2 d-1. The static mixers not only helped in improving the biomass productivities but also have a high potential to lower the photoinhibitory effect of light during the outdoor cultures of algae.

  9. Classical and Alternative Activation of Cyanobacterium Oscillatoria sp. Lipopolysaccharide-Treated Rat Microglia in vitro

    Science.gov (United States)

    Mayer, Alejandro M. S.; Murphy, Joseph; MacAdam, David; Osterbauer, Christopher; Baseer, Imaan; Hall, Mary L.; Feher, Domonkos; Williams, Phillip

    2016-01-01

    The purpose of this investigation was to test the hypothesis that an in vitro exposure to cyanobacterium Oscillatoria sp. Lipopolysaccharide (LPS) might result in classical and alternative activation of rat neonatal microglia. Using Escherichia coli LPS-primed microglia as a positive control, this study revealed that treatment of rat microglia with Oscillatoria sp. LPS for 17 h in vitro resulted in both classical and alternative activation as well as concomitant pro-inflammatory and anti-inflammatory mediator release, in a concentration-dependent manner: (1) treatment with 0.1–10 000 ng/ml Oscillatoria sp. LPS resulted in minimal lactic dehydrogenase (LDH) release, induced concentration-dependent and statistically significant O2− generation, matrix metalloproteinase-9 (MMP-9) release, generation of the cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), and the chemokines macrophage inflammatory protein-2 (MIP-2/CXCL2), interferon γ-induced protein 10 kDa (IP-10/CXCL-10), (MIP-1α/CCL3), monocyte chemotactic protein-1 (MCP-1/CCL2), regulated on activation, normal T cell expressed and secreted (RANTES/CCL5), and the alternative activation cytokine IL-10; (3) in contrast, treatment with 100 000 ng/ml Oscillatoria sp. LPS appeared to damage the microglia cell membrane, because it resulted in minimal O2− generation, statistically significant LDH release, and a decrease in the generation of all the cytokines and chemokines investigated, with the exception of IL-1α and cytokine-induced neutrophil chemoattractant 1 (CINC-1/CXCL1) generation, which was increased. Thus, our results provide experimental support for our working hypothesis, namely that Oscillatoria sp. LPS induces classical and alternative activation of rat brain microglia in vitro in a concentration-dependent manner, namely 0.1–10 000 ng/ml Oscillatoria sp. LPS, when microglia cells were shown to be viable. Furthermore, should cyanobacterium Oscillatoria sp. LPS gain

  10. [Growth and metabolite production of the marine cyanobacterium Synechococcus sp. (Chroococcales) in function to irradiance].

    Science.gov (United States)

    Rosales-Loaiza, Néstor; Guevara, Miguel; Lodeiros, César; Morales, Ever

    2008-06-01

    Changes in salinity, temperature and irradiance during wet and dry seasons have induced metabolic versatility in cyanobacteria from saline environments. Cyanobacteria from these environments have biotechnological potential for the production of metabolites with pharmaceutical and industrial interest. We studied the growth, dry mass and metabolite production of the cyanobacterium Synechococcus sp. MOF-03 in function of irradiance (78, 156 and 234 micromol q m(-2) s(-1)). All batch cultures were maintained by triplicate in constant aeration, 12:12 h photoperiod, 30 +/- 2 degrees C and 35% per hundred. Maximum values of protein, carbohydrates and lipids, of 530.19 +/- 11.16, 408.94 +/- 4.27 and 56.20 +/- 1.17 microg ml(-1), respectively, were achieved at 78 micromol q m(-2) s(-1). Pigments, analyzed by HPLC, showed maximum values at 78 micromol q m(-2) s(-1) for chlorophyll a with 7.72 +/- 0.16 microg ml(-1), and at 234 micromol q m(-2) s(-1) for beta-carotene and zeaxanthin with 0.70 +/- 0.01 and 0.67 +/- 0.05 microg ml(-1). Chlorophyll a:beta-carotene ratio decreased from 17.15 to 6.91 at 78 and 234 micromol q m(-2) s(-'1); whereas beta-carotene:zeaxanthin ratio showed no changes between 78 and 156 micromol q m(-2) s(-1), around 1.21, and decreased at 234 micromol q m(-2) s(-1), to 1.04. Also, this cyanobacterium produced the greatest cell density and dry mass at 156 micromol q m(-2) s(-1), with 406.13 +/- 21.74 x l0(6) cell ml(-1) and 1.49 +/- 0.11 mg ml(-1), respectively. Exopolysaccharide production was stable between 156 y 234 micromol q m(-2) s(-1), around 110 microg ml(-1). This Synechococcus strain shows a great potential for the production of enriched biomass with high commercial value metabolites.

  11. Sustained H(2) production driven by photosynthetic water splitting in a unicellular cyanobacterium.

    Science.gov (United States)

    Melnicki, Matthew R; Pinchuk, Grigoriy E; Hill, Eric A; Kucek, Leo A; Fredrickson, Jim K; Konopka, Allan; Beliaev, Alexander S

    2012-01-01

    The relationship between dinitrogenase-driven H(2) production and oxygenic photosynthesis was investigated in a unicellular cyanobacterium, Cyanothece sp. ATCC 51142, using a novel custom-built photobioreactor equipped with advanced process control. Continuously illuminated nitrogen-deprived cells evolved H(2) at rates up to 400 µmol ⋅ mg Chl(-1) ⋅ h(-1) in parallel with uninterrupted photosynthetic O(2) production. Notably, sustained coproduction of H(2) and O(2) occurred over 100 h in the presence of CO(2), with both gases displaying inverse oscillations which eventually dampened toward stable rates of 125 and 90 µmol ⋅ mg Chl(-1) ⋅ h(-1), respectively. Oscillations were not observed when CO(2) was omitted, and instead H(2) and O(2) evolution rates were positively correlated. The sustainability of the process was further supported by stable chlorophyll content, maintenance of baseline protein and carbohydrate levels, and an enhanced capacity for linear electron transport as measured by chlorophyll fluorescence throughout the experiment. In situ light saturation analyses of H(2) production displayed a strong dose dependence and lack of O(2) inhibition. Inactivation of photosystem II had substantial long-term effects but did not affect short-term H(2) production, indicating that the process is also supported by photosystem I activity and oxidation of endogenous glycogen. However, mass balance calculations suggest that carbohydrate consumption in the light may, at best, account for no more than 50% of the reductant required for the corresponding H(2) production over that period. Collectively, our results demonstrate that uninterrupted H(2) production in unicellular cyanobacteria can be fueled by water photolysis without the detrimental effects of O(2) and have important implications for sustainable production of biofuels. The study provides an important insight into the photophysiology of light-driven H(2) production by the nitrogen-fixing cyanobacterium

  12. CRISPR/Cas9 mediated targeted mutagenesis of the fast growing cyanobacterium Synechococcus elongatus UTEX 2973.

    Science.gov (United States)

    Wendt, Kristen E; Ungerer, Justin; Cobb, Ryan E; Zhao, Huimin; Pakrasi, Himadri B

    2016-06-23

    As autotrophic prokaryotes, cyanobacteria are ideal chassis organisms for sustainable production of various useful compounds. The newly characterized cyanobacterium Synechococcus elongatus UTEX 2973 is a promising candidate for serving as a microbial cell factory because of its unusually rapid growth rate. Here, we seek to develop a genetic toolkit that enables extensive genomic engineering of Synechococcus 2973 by implementing a CRISPR/Cas9 editing system. We targeted the nblA gene because of its important role in biological response to nitrogen deprivation conditions. First, we determined that the Streptococcus pyogenes Cas9 enzyme is toxic in cyanobacteria, and conjugational transfer of stable, replicating constructs containing the cas9 gene resulted in lethality. However, after switching to a vector that permitted transient expression of the cas9 gene, we achieved markerless editing in 100 % of cyanobacterial exconjugants after the first patch. Moreover, we could readily cure the organisms of antibiotic resistance, resulting in a markerless deletion strain. High expression levels of the Cas9 protein in Synechococcus 2973 appear to be toxic and result in cell death. However, introduction of a CRISPR/Cas9 genome editing system on a plasmid backbone that leads to transient cas9 expression allowed for efficient markerless genome editing in a wild type genetic background.

  13. Glycosylated Porphyra-334 and Palythine-Threonine from the Terrestrial Cyanobacterium Nostoc commune

    Science.gov (United States)

    Nazifi, Ehsan; Wada, Naoki; Yamaba, Minami; Asano, Tomoya; Nishiuchi, Takumi; Matsugo, Seiichi; Sakamoto, Toshio

    2013-01-01

    Mycosporine-like amino acids (MAAs) are water-soluble UV-absorbing pigments, and structurally different MAAs have been identified in eukaryotic algae and cyanobacteria. In this study novel glycosylated MAAs were found in the terrestrial cyanobacterium Nostoc commune (N. commune). An MAA with an absorption maximum at 334 nm was identified as a hexose-bound porphyra-334 derivative with a molecular mass of 508 Da. Another MAA with an absorption maximum at 322 nm was identified as a two hexose-bound palythine-threonine derivative with a molecular mass of 612 Da. These purified MAAs have radical scavenging activities in vitro, which suggests multifunctional roles as sunscreens and antioxidants. The 612-Da MAA accounted for approximately 60% of the total MAAs and contributed approximately 20% of the total radical scavenging activities in a water extract, indicating that it is the major water-soluble UV-protectant and radical scavenger component. The hexose-bound porphyra-334 derivative and the glycosylated palythine-threonine derivatives were found in a specific genotype of N. commune, suggesting that glycosylated MAA patterns could be a chemotaxonomic marker for the characterization of the morphologically indistinguishable N. commune. The glycosylation of porphyra-334 and palythine-threonine in N. commune suggests a unique adaptation for terrestrial environments that are drastically fluctuating in comparison to stable aquatic environments. PMID:24065157

  14. Glycosylated Porphyra-334 and Palythine-Threonine from the Terrestrial Cyanobacterium Nostoc commune

    Directory of Open Access Journals (Sweden)

    Toshio Sakamoto

    2013-08-01

    Full Text Available Mycosporine-like amino acids (MAAs are water-soluble UV-absorbing pigments, and structurally different MAAs have been identified in eukaryotic algae and cyanobacteria. In this study novel glycosylated MAAs were found in the terrestrial cyanobacterium Nostoc commune (N. commune. An MAA with an absorption maximum at 334 nm was identified as a hexose-bound porphyra-334 derivative with a molecular mass of 508 Da. Another MAA with an absorption maximum at 322 nm was identified as a two hexose-bound palythine-threonine derivative with a molecular mass of 612 Da. These purified MAAs have radical scavenging activities in vitro, which suggests multifunctional roles as sunscreens and antioxidants. The 612-Da MAA accounted for approximately 60% of the total MAAs and contributed approximately 20% of the total radical scavenging activities in a water extract, indicating that it is the major water-soluble UV-protectant and radical scavenger component. The hexose-bound porphyra-334 derivative and the glycosylated palythine-threonine derivatives were found in a specific genotype of N. commune, suggesting that glycosylated MAA patterns could be a chemotaxonomic marker for the characterization of the morphologically indistinguishable N. commune. The glycosylation of porphyra-334 and palythine-threonine in N. commune suggests a unique adaptation for terrestrial environments that are drastically fluctuating in comparison to stable aquatic environments.

  15. CyanOmics: an integrated database of omics for the model cyanobacterium Synechococcus sp. PCC 7002.

    Science.gov (United States)

    Yang, Yaohua; Feng, Jie; Li, Tao; Ge, Feng; Zhao, Jindong

    2015-01-01

    Cyanobacteria are an important group of organisms that carry out oxygenic photosynthesis and play vital roles in both the carbon and nitrogen cycles of the Earth. The annotated genome of Synechococcus sp. PCC 7002, as an ideal model cyanobacterium, is available. A series of transcriptomic and proteomic studies of Synechococcus sp. PCC 7002 cells grown under different conditions have been reported. However, no database of such integrated omics studies has been constructed. Here we present CyanOmics, a database based on the results of Synechococcus sp. PCC 7002 omics studies. CyanOmics comprises one genomic dataset, 29 transcriptomic datasets and one proteomic dataset and should prove useful for systematic and comprehensive analysis of all those data. Powerful browsing and searching tools are integrated to help users directly access information of interest with enhanced visualization of the analytical results. Furthermore, Blast is included for sequence-based similarity searching and Cluster 3.0, as well as the R hclust function is provided for cluster analyses, to increase CyanOmics's usefulness. To the best of our knowledge, it is the first integrated omics analysis database for cyanobacteria. This database should further understanding of the transcriptional patterns, and proteomic profiling of Synechococcus sp. PCC 7002 and other cyanobacteria. Additionally, the entire database framework is applicable to any sequenced prokaryotic genome and could be applied to other integrated omics analysis projects. Database URL: http://lag.ihb.ac.cn/cyanomics. © The Author(s) 2015. Published by Oxford University Press.

  16. Semicontinuous cultivation of the cyanobacterium Spirulina platensis in a closed photobioreactor

    Directory of Open Access Journals (Sweden)

    C. C. Reichert

    2006-03-01

    Full Text Available The cultivation of photosynthetic microorganisms such as the cyanobacterium Spirulina platensis has been studied by researchers in many countries because these organisms can produce products with industrial potential. We studied the specific growth rate (µx, day-1 and productivity (Px, in mg/L/day of Spirulina platensis biomass, dry weight basis of two S. platensis strains (LEB-52 and Paracas growing in aerated semicontinuous culture in two-liter Erlenmeyer flasks for 90 days (2160 h at 30°C under 2500 lux of illumination in a 12 h photoperiod. Independent of the S. platensis strain used we found that low biomass concentrations (0.50 g/L and high renewal rates (50% v/v resulted in a high specific growth rate (µx = 0.111 day-1 and high productivity (Px = 42.3 mg/L/day. These values are two to four times higher than those obtained in simple batch cultivation and indicate that the semicontinuous cultivation of S. platensis is viable.

  17. Theoretical investigation of biomass productivities achievable in solar rectangular photobioreactors for the cyanobacterium Arthrospira platensis.

    Science.gov (United States)

    Pruvost, Jeremy; Cornet, J F; Goetz, Vincent; Legrand, Jack

    2012-01-01

    Modeling was done to simulate whole-year running of solar rectangular photobioreactors (PBRs). Introducing the concept of ideal reactor, the maximal biomass productivity that could be achieved on Earth on nitrate as N-source was calculated. Two additional factors were also analyzed with respect to dynamic calculations over the whole year: the effect of PBR location and the effects of given operating conditions on the resulting decrease in productivity compared with the ideal one. Simulations were conducted for the cyanobacterium Arthospira platensis, giving an ideal productivity (upper limit) in the range 55-60 tX ha(-1) year(-1) for a sun tracking system (and around 35-40 tX ha(-1) year(-1) for a fixed horizontal PBR). For an implantation in France (Nantes, west coast), the modification in irradiation conditions resulted in a decrease in biomass productivity of 40%. Various parameters were investigated, with special emphasis on the influence of the incident angle of solar illumination on resulting productivities, affecting both light capture and light transfer inside the bulk culture. It was also found that with appropriate optimization of the residence time as permitted by the model, productivities close to maximal could be achieved for a given location. Copyright © 2012 American Institute of Chemical Engineers (AIChE).

  18. Growth enhancing effect of exogenous glycine and characterization of its uptake in halotolerant cyanobacterium Aphanothece halophytica.

    Science.gov (United States)

    Bualuang, Aporn; Incharoensakdi, Aran

    2015-02-01

    Alkaliphilic halotolerant cyanobacterium Aphanothece halophytica showed optimal growth in the medium containing 0.5 M NaCl. The increase of exogenously added glycine to the medium up to 10 mM significantly promoted cell growth under both normal (0.5 M NaCl) and salt stress (2.0 M NaCl) conditions. Salt stress imposed by either 2.0 or 3.0 M NaCl retarded cell growth; however, exogenously added glycine at 10 mM concentration to salt-stress medium resulted in the reduction of growth inhibition particularly under 3.0 M NaCl condition. The uptake of glycine by intact A. halophytica was shown to exhibit saturation kinetics with an apparent K s of 160 μM and V max of 3.9 nmol/min/mg protein. The optimal pH for glycine uptake was at pH 8.0. The uptake activity was decreased in the presence of high concentration of NaCl. Both metabolic inhibitors and ionophores decreased glycine uptake in A. halophytica suggesting an energy-dependent glycine uptake. Several neutral amino acids showed considerable inhibition of glycine uptake with higher than 50 % inhibition observed with serine, cysteine and alanine whereas acidic, basic and aromatic amino acids showed only slight inhibition of glycine uptake.

  19. Proteome-wide analysis and diel proteomic profiling of the cyanobacterium Arthrospira platensis PCC 8005.

    Directory of Open Access Journals (Sweden)

    Sabine Matallana-Surget

    Full Text Available The filamentous cyanobacterium Arthrospira platensis has a long history of use as a food supply and it has been used by the European Space Agency in the MELiSSA project, an artificial microecosystem which supports life during long-term manned space missions. This study assesses progress in the field of cyanobacterial shotgun proteomics and light/dark diurnal cycles by focusing on Arthrospira platensis. Several fractionation workflows including gel-free and gel-based protein/peptide fractionation procedures were used and combined with LC-MS/MS analysis, enabling the overall identification of 1306 proteins, which represents 21% coverage of the theoretical proteome. A total of 30 proteins were found to be significantly differentially regulated under light/dark growth transition. Interestingly, most of the proteins showing differential abundance were related to photosynthesis, the Calvin cycle and translation processes. A novel aspect and major achievement of this work is the successful improvement of the cyanobacterial proteome coverage using a 3D LC-MS/MS approach, based on an immobilized metal affinity chromatography, a suitable tool that enabled us to eliminate the most abundant protein, the allophycocyanin. We also demonstrated that cell growth follows a light/dark cycle in A. platensis. This preliminary proteomic study has highlighted new characteristics of the Arthrospira platensis proteome in terms of diurnal regulation.

  20. Effect of Selected Plant Extracts and D- and L-Lysine on the Cyanobacterium Microcystis aeruginosa

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    Miquel Lürling

    2014-06-01

    Full Text Available We tested extracts from Fructus mume, Salvia miltiorrhiza and Moringa oleifera as well as L-lysine and D-Lysine as curative measures to rapidly suppress the cyanobacterium Microcystis aeruginosa NIVA-CYA 43. We tested these compounds under similar conditions to facilitate comparisons. We hypothesized that for each compound, relatively low concentrations—i.e., 5–50 mg L−1, would reduce M. aeruginosa biomass. At these low concentrations, only L-lysine caused a decline in M. aeruginosa biomass at ≥4.3 mg L−1. F. mume extract was effective to do so at high concentrations, i.e., at ≥240 mg L−1, but the others were virtually non-effective. Low pH caused by organic acids is a probable explanation for the effect of F. mume extract. No complete wipe-outs of the experimental population were achieved as Photosystem II efficiency showed a recovery after six days. L-lysine may be effective at low concentrations—meaning low material costs. However, the effect of L-lysine seems relatively short-lived. Overall, the results of our study did not support the use of the tested plant extracts and amino-acid as promising candidates for curative application in M. aeruginosa bloom control.

  1. Hydrogen sulfide can inhibit and enhance oxygenic photosynthesis in a cyanobacterium from sulfidic springs.

    Science.gov (United States)

    Klatt, Judith M; Haas, Sebastian; Yilmaz, Pelin; de Beer, Dirk; Polerecky, Lubos

    2015-09-01

    We used microsensors to investigate the combinatory effect of hydrogen sulfide (H2 S) and light on oxygenic photosynthesis in biofilms formed by a cyanobacterium from sulfidic springs. We found that photosynthesis was both positively and negatively affected by H2 S: (i) H2 S accelerated the recovery of photosynthesis after prolonged exposure to darkness and anoxia. We suggest that this is possibly due to regulatory effects of H2 S on photosystem I components and/or on the Calvin cycle. (ii) H2 S concentrations of up to 210 μM temporarily enhanced the photosynthetic rates at low irradiance. Modelling showed that this enhancement is plausibly based on changes in the light-harvesting efficiency. (iii) Above a certain light-dependent concentration threshold H2 S also acted as an inhibitor. Intriguingly, this inhibition was not instant but occurred only after a specific time interval that decreased with increasing light intensity. That photosynthesis is most sensitive to inhibition at high light intensities suggests that H2 S inactivates an intermediate of the oxygen evolving complex that accumulates with increasing light intensity. We discuss the implications of these three effects of H2 S in the context of cyanobacterial photosynthesis under conditions with diurnally fluctuating light and H2 S concentrations, such as those occurring in microbial mats and biofilms. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  2. Ultradian metabolic rhythm in the diazotrophic cyanobacterium Cyanothece sp. ATCC 51142.

    Science.gov (United States)

    Červený, Jan; Sinetova, Maria A; Valledor, Luis; Sherman, Louis A; Nedbal, Ladislav

    2013-08-06

    The unicellular cyanobacterium Cyanothece sp. American Type Culture Collection (ATCC) 51142 is capable of performing oxygenic photosynthesis during the day and microoxic nitrogen fixation at night. These mutually exclusive processes are possible only by temporal separation by circadian clock or another cellular program. We report identification of a temperature-dependent ultradian metabolic rhythm that controls the alternating oxygenic and microoxic processes of Cyanothece sp. ATCC 51142 under continuous high irradiance and in high CO2 concentration. During the oxygenic photosynthesis phase, nitrate deficiency limited protein synthesis and CO2 assimilation was directed toward glycogen synthesis. The carbohydrate accumulation reduced overexcitation of the photosynthetic reactions until a respiration burst initiated a transition to microoxic N2 fixation. In contrast to the circadian clock, this ultradian period is strongly temperature-dependent: 17 h at 27 °C, which continuously decreased to 10 h at 39 °C. The cycle was expressed by an oscillatory modulation of net O2 evolution, CO2 uptake, pH, fluorescence emission, glycogen content, cell division, and culture optical density. The corresponding ultradian modulation was also observed in the transcription of nitrogenase-related nifB and nifH genes and in nitrogenase activities. We propose that the control by the newly identified metabolic cycle adds another rhythmic component to the circadian clock that reflects the true metabolic state depending on the actual temperature, irradiance, and CO2 availability.

  3. The stringent response regulates adaptation to darkness in the cyanobacterium Synechococcus elongatus.

    Science.gov (United States)

    Hood, Rachel D; Higgins, Sean A; Flamholz, Avi; Nichols, Robert J; Savage, David F

    2016-08-16

    The cyanobacterium Synechococcus elongatus relies upon photosynthesis to drive metabolism and growth. During darkness, Synechococcus stops growing, derives energy from its glycogen stores, and greatly decreases rates of macromolecular synthesis via unknown mechanisms. Here, we show that the stringent response, a stress response pathway whose genes are conserved across bacteria and plant plastids, contributes to this dark adaptation. Levels of the stringent response alarmone guanosine 3'-diphosphate 5'-diphosphate (ppGpp) rise after a shift from light to dark, indicating that darkness triggers the same response in cyanobacteria as starvation in heterotrophic bacteria. High levels of ppGpp are sufficient to stop growth and dramatically alter many aspects of cellular physiology, including levels of photosynthetic pigments and polyphosphate, DNA content, and the rate of translation. Cells unable to synthesize ppGpp display pronounced growth defects after exposure to darkness. The stringent response regulates expression of a number of genes in Synechococcus, including ribosomal hibernation promoting factor (hpf), which causes ribosomes to dimerize in the dark and may contribute to decreased translation. Although the metabolism of Synechococcus differentiates it from other model bacterial systems, the logic of the stringent response remains remarkably conserved, while at the same time having adapted to the unique stresses of the photosynthetic lifestyle.

  4. Anaerobic biosynthesis of unsaturated fatty acids in the cyanobacterium, Oscillatoria limnetica

    Science.gov (United States)

    Jahnke, L. L.; Lee, B.; Sweeney, M. J.; Klein, H. P.

    1989-01-01

    The mechanism for synthesis of monounsaturated fatty acids under aerobic and anaerobic conditions was studied in the facultative anaerobic cyanobacterium, Oscillatoria limnetica. The hexadecenoic acid (C16:1) of aerobically grown O. limnetica was shown to contain both the delta 7 (79%) and delta 9 (21%) isomers, while the octadecenoic (C18:1) acid was entirely the delta 9 acid. Incorporation of [2-14C] acetate into the fatty acids under aerobic conditions resulted in synthesis of the delta 7 and delta 9 C16:1 and the delta 9 C18:1. Synthesis of unsaturated fatty acids in the presence of DCMU required sulfide. Anaerobic incubations in the presence of DCMU and sulfide (less than 0.003% atmospheric oxygen) resulted in a two-fold increase in monounsaturated fatty acids of both delta 7 and delta 9 C16:1 and delta 9 and delta 11 C18:1. The synthesis of these is characteristic of a bacterial-type, anaerobic pathway.

  5. Accelerating of Pink Pigment Excretion from Cyanobacterium Oscillatoria by Co-Cultivation with Anabaena

    Directory of Open Access Journals (Sweden)

    DWI SUSILANINGSIH

    2007-03-01

    Full Text Available The freshwater cyanobacterium Oscillatoria BTCC/A 0004 excretes pink pigment containing lipoproteins with molecular weights of about 10 kDa. This pigment has surfactant properties with strong emulsification activity toward several hydrocarbons. This extracellular metabolite was suspected as toxin or allelochemical in their habitat. In this study, I investigated the effect of co-cultivation of Oscillatoria with Anabaena variabilis on the pigment excretion to explore the physiological roles of this pigment in its natural environment. The dead or viable cells and medium of A. variabilis were added into Oscillatoria cultures. Results showed that co-cultivation of free viable cells of A. variabilis enhanced the excretion of pigment without effect on the cell growth. Co-cultivation with viable cells in separated method and dead cells did not influenced the pigment production. The addition of A. variabilis medium was slightly increased the excretion of the pigment. Those results indicated that direct contact with A. variabilis caused Oscillatoria released a certain signaling compound.

  6. Interaction between carbon and nitrogen metabolism during akinete development in the cyanobacterium Anabaena torulosa.

    Science.gov (United States)

    Ahuja, Gurpreet; Khattar, Jasvirinder Singh; Sarma, Tangirala Anjaneya

    2008-04-01

    Nutrient enrichment with a nitrogen (as nitrate) or carbon (as fructose) source to unaerated diazo and photoautorophic cultures of the cyanobacterium Anabaena torulosa induced early development of akinetes with high frequency. When cultures under any mode of nutrition were aerated, akinetes were not differentiated. Unaerated cultures with nitrate nitrogen or fructose exhibited higher respiratory rates and nitrogen assimilation compared to aerated cultures. This was evidenced by increased respiratory O2 uptake and high activities of pyruvate kinase, malate dehydrogenase (NAD+), nitrogenase and nitrate reductase signifying that akinete forming unaerated cultures exhibited high carbon dissimilation and nitrogen assimilation resulting in high nitrogenous build up in the cells. Aerated, non-akinete cultures, on the other hand, were associated with low respiratory O2 uptake, low pyruvate kinase and malate dehydrogenase (NAD+) activities, suggesting that carbon dissimilation was not favoured either in presence of nitrate or fructose. Moreover, higher activity of NADP+ linked malate dehydrogenase and lower nitrate reductase activity in aerated cultures led to a high carbon and low nitrogen content of the cells resulting in high cellular C:N ratio. The results suggest that interaction between carbon and nitrogen metabolism regulates akinete development in A. torulosa.

  7. ORGANIZATION OF THE nif GENES OF THE NONHETEROCYSTOUS CYANOBACTERIUM TRICHODESMIUM SP. IMS101.

    Science.gov (United States)

    Dominic, Benny; Zani, Sabino; Chen, Yi-Bu; Mellon, Mark T; Zehr, Jonathan P

    2000-08-26

    An approximately 16-kb fragment of the Trichodesmium sp. IMS101 (a nonheterocystous filamentous cyanobacterium) "conventional"nif gene cluster was cloned and sequenced. The gene organization of the Trichodesmium and Anabaena variabilis vegetative (nif 2) nitrogenase gene clusters spanning the region from nif B to nif W are similar except for the absence of two open reading frames (ORF3 and ORF1) in Trichodesmium. The Trichodesmium nif EN genes encode a fused Nif EN polypeptide that does not appear to be processed into individual Nif E and Nif N polypeptides. Fused nif EN genes were previously found in the A. variabilis nif 2 genes, but we have found that fused nif EN genes are widespread in the nonheterocystous cyanobacteria. Although the gene organization of the nonheterocystous filamentous Trichodesmium nif gene cluster is very similar to that of the A. variabilis vegetative nif 2 gene cluster, phylogenetic analysis of nif sequences do not support close relatedness of Trichodesmium and A. variabilis vegetative (nif 2) nitrogenase genes.

  8. Anoxygenic Photosynthesis Controls Oxygenic Photosynthesis in a Cyanobacterium from a Sulfidic Spring

    KAUST Repository

    Klatt, Judith M.

    2015-03-15

    Before the Earth\\'s complete oxygenation (0.58 to 0.55 billion years [Ga] ago), the photic zone of the Proterozoic oceans was probably redox stratified, with a slightly aerobic, nutrient-limited upper layer above a light-limited layer that tended toward euxinia. In such oceans, cyanobacteria capable of both oxygenic and sulfide-driven anoxygenic photosynthesis played a fundamental role in the global carbon, oxygen, and sulfur cycle. We have isolated a cyanobacterium, Pseudanabaena strain FS39, in which this versatility is still conserved, and we show that the transition between the two photosynthetic modes follows a surprisingly simple kinetic regulation controlled by this organism\\'s affinity for H2S. Specifically, oxygenic photosynthesis is performed in addition to anoxygenic photosynthesis only when H2S becomes limiting and its concentration decreases below a threshold that increases predictably with the available ambient light. The carbon-based growth rates during oxygenic and anoxygenic photosynthesis were similar. However, Pseudanabaena FS39 additionally assimilated NO3 - during anoxygenic photosynthesis. Thus, the transition between anoxygenic and oxygenic photosynthesis was accompanied by a shift of the C/N ratio of the total bulk biomass. These mechanisms offer new insights into the way in which, despite nutrient limitation in the oxic photic zone in the mid-Proterozoic oceans, versatile cyanobacteria might have promoted oxygenic photosynthesis and total primary productivity, a key step that enabled the complete oxygenation of our planet and the subsequent diversification of life.

  9. Effect of solar radiation on photosynthesis and pigmentation in the cyanobacterium microcoleus chtihonoplastes

    International Nuclear Information System (INIS)

    Annan, J.N.; Galyuon, I. K. A.; Donkor, V.A.

    2007-01-01

    The effects of solar radiation on the photosynthetic oxygen production and pigmentation were investigated in the marine filamentous cyanobacterium. Microcoleus chthonoplastes harvested from the intertidal zone of the Biriwa coast in Ghana. The organism was exposed to unfiltered solar radiation (UV-B. UV-A and PAR) and solar radiation filtered through optical filters. WG320 (UV-A and PAR), GG400 (PAR only), and UG5 (only UV-B and UV-A), Photosynthetic oxygen production was impaired. The reduction in the rate of photosynthetic oxygen production took over 2 hours to occur. The photoinhibition due to unfiltered solar radiation and combined UV-A and PAR were most severe. Absorption spectra of the crude extracts of M. chthonoplastes, indicated the presence of chlorophyll a, carotenoids, phycoerythrin and phycocyanin as the photosynthetic pigments, which were significantly bleached under the various solar radiation wavelengths. Generally, the phycobilins were affected most. Fluorescence measurements showed peaks that decreased significantly in amplitude and also underwent a shift towards shorter wavelengths, with prolonged exposure time, indicating that energy transfer from the accessory pigments was adversely affected. The implication is that increased solar radiation may have severe consequences on the marine ecosystem. (au)

  10. Envelope structure of Synechococcus sp. WH8113, a nonflagellated swimming cyanobacterium

    Directory of Open Access Journals (Sweden)

    Reese Thomas S

    2001-04-01

    Full Text Available Abstract Background Many bacteria swim by rotating helical flagellar filaments [1]. Waterbury et al. [15] discovered an exception, strains of the cyanobacterium Synechococcus that swim without flagella or visible changes in shape. Other species of cyanobacteria glide on surfaces [2,7]. The hypothesis that Synechococcus might swim using traveling surface waves [6,13] prompted this investigation. Results Using quick-freeze electron microscopy, we have identified a crystalline surface layer that encloses the outer membrane of the motile strain Synechococcus sp. WH8113, the components of which are arranged in a rhomboid lattice. Spicules emerge in profusion from the layer and extend up to 150 nm into the surrounding fluid. These spicules also send extensions inwards to the inner cell membrane where motility is powered by an ion-motive force [17]. Conclusion The envelope structure of Synechococcus sp. WH8113 provides new constraints on its motile mechanism. The spicules are well positioned to transduce energy at the cell membrane into mechanical work at the cell surface. One model is that an unidentified motor embedded in the cell membrane utilizes the spicules as oars to generate a traveling wave external to the surface layer in the manner of ciliated eukaryotes.

  11. Anoxygenic photosynthesis controls oxygenic photosynthesis in a cyanobacterium from a sulfidic spring.

    Science.gov (United States)

    Klatt, Judith M; Al-Najjar, Mohammad A A; Yilmaz, Pelin; Lavik, Gaute; de Beer, Dirk; Polerecky, Lubos

    2015-03-01

    Before the Earth's complete oxygenation (0.58 to 0.55 billion years [Ga] ago), the photic zone of the Proterozoic oceans was probably redox stratified, with a slightly aerobic, nutrient-limited upper layer above a light-limited layer that tended toward euxinia. In such oceans, cyanobacteria capable of both oxygenic and sulfide-driven anoxygenic photosynthesis played a fundamental role in the global carbon, oxygen, and sulfur cycle. We have isolated a cyanobacterium, Pseudanabaena strain FS39, in which this versatility is still conserved, and we show that the transition between the two photosynthetic modes follows a surprisingly simple kinetic regulation controlled by this organism's affinity for H2S. Specifically, oxygenic photosynthesis is performed in addition to anoxygenic photosynthesis only when H2S becomes limiting and its concentration decreases below a threshold that increases predictably with the available ambient light. The carbon-based growth rates during oxygenic and anoxygenic photosynthesis were similar. However, Pseudanabaena FS39 additionally assimilated NO3 (-) during anoxygenic photosynthesis. Thus, the transition between anoxygenic and oxygenic photosynthesis was accompanied by a shift of the C/N ratio of the total bulk biomass. These mechanisms offer new insights into the way in which, despite nutrient limitation in the oxic photic zone in the mid-Proterozoic oceans, versatile cyanobacteria might have promoted oxygenic photosynthesis and total primary productivity, a key step that enabled the complete oxygenation of our planet and the subsequent diversification of life. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  12. Photosynthetic performance of a helical tubular photobioreactor incorporating the cyanobacterium Spirulina platensis

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Yoshitomo; Hall, D.O. [Univ. of London (United Kingdom); Nouee, J. De La [Univ. Laval, Quebec City, Quebec (Canada). Dept. of Food Science and Technology

    1995-07-20

    The photosynthetic performance of a helical tubular photobioreactor (``Biocoil``), incorporating the filamentous cyanobacterium Spirulina platensis, was investigated. The photobioreactor was constructed in a cylindrical shape with a 0.25-m{sup 2} basal area and a photostage comprising 60 m of transparent PVC tubing of 1.6-cm inner diameter. The inner surface of the cylinder was illuminated with cool white fluorescent lamps; the energy input of photosynthetically active radiation into the photobioreactor was 2,920 kJ per day. An air-lift system incorporating 4% CO{sub 2} was used to circulate the growth medium in the tubing. The maximum productivity achieved in batch culture was 7.18 g dry biomass per day which corresponded to a photosynthetic (PAR) efficiency of 5.45%. The CO{sub 2} was efficiently removed from the gaseous stream; monitoring the CO{sub 2} in the outlet and inlet gas streams showed a 70% removal of CO{sub 2} from the inlet gas over an 8-h period with almost maximum growth rate.

  13. Genomic Structure of an Economically Important Cyanobacterium, Arthrospira (Spirulina) platensis NIES-39

    Science.gov (United States)

    Fujisawa, Takatomo; Narikawa, Rei; Okamoto, Shinobu; Ehira, Shigeki; Yoshimura, Hidehisa; Suzuki, Iwane; Masuda, Tatsuru; Mochimaru, Mari; Takaichi, Shinichi; Awai, Koichiro; Sekine, Mitsuo; Horikawa, Hiroshi; Yashiro, Isao; Omata, Seiha; Takarada, Hiromi; Katano, Yoko; Kosugi, Hiroki; Tanikawa, Satoshi; Ohmori, Kazuko; Sato, Naoki; Ikeuchi, Masahiko; Fujita, Nobuyuki; Ohmori, Masayuki

    2010-01-01

    A filamentous non-N2-fixing cyanobacterium, Arthrospira (Spirulina) platensis, is an important organism for industrial applications and as a food supply. Almost the complete genome of A. platensis NIES-39 was determined in this study. The genome structure of A. platensis is estimated to be a single, circular chromosome of 6.8 Mb, based on optical mapping. Annotation of this 6.7 Mb sequence yielded 6630 protein-coding genes as well as two sets of rRNA genes and 40 tRNA genes. Of the protein-coding genes, 78% are similar to those of other organisms; the remaining 22% are currently unknown. A total 612 kb of the genome comprise group II introns, insertion sequences and some repetitive elements. Group I introns are located in a protein-coding region. Abundant restriction-modification systems were determined. Unique features in the gene composition were noted, particularly in a large number of genes for adenylate cyclase and haemolysin-like Ca2+-binding proteins and in chemotaxis proteins. Filament-specific genes were highlighted by comparative genomic analysis. PMID:20203057

  14. Semicontinuous cultivation of the Cyanobacterium Spirulina platensis in a closed photobioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Reichert, C.C.; Costa, J.A.V. [Fundacao Universidade Federal do Rio Grande (FURG), Rio Grande, RS (Brazil). Dept. de Quimica], Email: dqmjorge@furg.br; Reinehr, C.O. [Universidade de Passo Fundo, RS (Brazil). Centro de Pesquisa em Alimentacao], Email: reinehr@upf.br

    2006-01-15

    The cultivation of photosynthetic microorganisms such as the cyanobacterium Spirulina platensis has been studied by researchers in many countries because these organisms can produce products with industrial potential. We studied the specific growth rate ({mu}{sub x}, day{sup -1}) and productivity (P{sub x}, in mg/L/day of Spirulina platensis biomass, dry weight basis) of two S. platensis strains (LEB-52 and Paracas) growing in aerated semicontinuous culture in two-liter Erlenmeyer flasks for 90 days (2160 h) at 30 deg C under 2500 lux of illumination in a 12 h photoperiod. Independent of the S. platensis strain used we found that low biomass concentrations (0.50 g/L) and high renewal rates (50% v/v) resulted in a high specific growth rate ({mu}{sub x} = 0.111 day{sup -1}) and high productivity (P{sub x} = 42.3 mg/L/day). These values are two to four times higher than those obtained in simple batch cultivation and indicate that the semicontinuous cultivation of S. platensis is viable. (author)

  15. Detection of weed algae in open pond cultures of Cyanobacterium aponinum using PAM

    Directory of Open Access Journals (Sweden)

    Dominik Winckelmann

    2016-02-01

    Full Text Available Abstract The potential use of non-arable land in the al-Wusta region of the Sultanate of Oman for the production of algae biomass was examined. Brackish cleaned production water from oil production supplemented with commercial fertilizer was used as growth medium. The indigenous isolate Cyanobacterium aponinum WP7(1 was grown in open ponds using batch or semi-continuous cultivation. Biomass production rates of 15–24 g/m2/day were achieved. The change of salinity due to evaporation, which was thought to be a major challenge, did not exceed 35 ppt. All cultures showed contaminations with weed algae. Contaminations with green algae or diatoms were detectable using fluorescence pattern excited by four different wavelengths using a pulse-amplitude-modulation chlorophyll fluorometer (PAM. It is possible to estimate the health level and the mayor groups of which a culture is composed using the PAM method. Therefore, the fluorescence of the photosynthetically inactive sample is compared with the fluorescence after all copies of photosystem II were closed by exposing the sample to a high-intensity light beam. A detection limit of one weed algae cell in a hundred cells was achieved.

  16. Toxin release in response to oxidative stress and programmed cell death in the cyanobacterium Microcystis aeruginosa

    Energy Technology Data Exchange (ETDEWEB)

    Ross, Cliff [Smithsonian Marine Station at Fort Pierce, 701 Seaway Drive, Ft. Pierce, FL 34949 (United States)]. E-mail: Ross@sms.si.edu; Santiago-Vazquez, Lory [Department of Chemistry and Biochemistry, Florida Atlantic University, 777 Glades Road, Boca Raton, FL 33431 (United States); Paul, Valerie [Smithsonian Marine Station at Fort Pierce, 701 Seaway Drive, Ft. Pierce, FL 34949 (United States)

    2006-06-10

    An unprecedented bloom of the cyanobacterium Microcystis aeruginosa Kuetz. occurred in the St. Lucie Estuary, FL in the summer of 2005. Samples were analyzed for toxicity by ELISA and by use of the polymerase chain reaction (PCR) with specific oligonucleotide primers for the mcyB gene that has previously been correlated with the biosynthesis of toxic microcystins. Despite the fact that secreted toxin levels were relatively low in dense natural assemblages (3.5 {mu}g l{sup -1}), detectable toxin levels increased by 90% when M. aeruginosa was stressed by an increase in salinity, physical injury, application of the chemical herbicide paraquat, or UV irradiation. The application of the same stressors caused a three-fold increase in the production of H{sub 2}O{sub 2} when compared to non-stressed cells. The application of micromolar concentrations of H{sub 2}O{sub 2} induced programmed cell death (PCD) as measured by a caspase protease assay. Catalase was capable of inhibiting PCD, implicating H{sub 2}O{sub 2} as the inducing oxidative species. Our results indicate that physical stressors induce oxidative stress, which results in PCD and a concomitant release of toxin into the surrounding media. Remediation strategies that induce cellular stress should be approached with caution since these protocols are capable of releasing elevated levels of microcystins into the environment.

  17. Effect of carbon and nitrogen assimilation on chlorophyll fluorescence emission by the cyanobacterium Anacystis nidulans

    Energy Technology Data Exchange (ETDEWEB)

    Romero, J.M.; Lara, C. (Instituto de Bioquimica Vegetal y Fotosintesis, Univ. de Sevilla y CSIC, Sevilla (ES)); Sivak, M.N. (Dept. of Biochemistry, Michigan State Univ., East Lansing (US))

    1992-01-01

    O{sub 2} evolution and chlorophyll A fluorescence emission have been monitored in intact cells of the cyanobacterium Anacystis nidulans 1402-1 to study the influence of carbon and nitrogen assimilation on the operation of the photosynthetic apparatus. The pattern of fluorescence induction in dark-adapted cyanobacterial cells was different from that of higher plants. Cyanobacteria undergo large, rapid state transitions upon illumination, which lead to marked changes in the fluorescence yield, complicating the estimation of quenching coefficients. The Kautsky effect was not evident, although it could be masked by a state II-state I transition, upon illumination with actinic light. The use of inhibitors of carbon assimilation such as D,L-glyceraldehyde or iodoacetamide allowed us to relate changes in variable fluorescence to active CO{sub 2} fixation. Ammonium, but not nitrate, induced non-photochemical fluorescence quenching, in agreement with a previous report on green algae, indicative of an ammonium-induced state i transition. (au).

  18. The success of the cyanobacterium Cylindrospermopsis raciborskii in freshwaters is enhanced by the combined effects of light intensity and temperature

    Directory of Open Access Journals (Sweden)

    Sylvia Bonilla

    2016-06-01

    Full Text Available Toxic cyanobacterial blooms in freshwaters are thought to be a consequence of the combined effects of anthropogenic eutrophication and climate change. It is expected that climate change will affect water mixing regimes that alter the water transparency and ultimately the light environment for phytoplankton. Blooms of the potentially toxic cyanobacterium Cylindrospermopsis raciborskii are expanding from tropical towards temperate regions. Several hypotheses have been proposed to explain this expansion, including an increase in water temperature due to climate change and the high phenotypic plasticity of the species that allows it to exploit different light environments. We performed an analysis based on eight lakes in tropical, subtropical and temperate regions to examine the distribution and abundance of C. raciborskii in relation to water temperature and transparency. We then conducted a series of short-term factorial experiments that combined three temperatures and two light intensity levels using C. raciborskii cultures alone and in interaction with another cyanobacterium to identify its growth capacity. Our results from the field, in contrast to predictions, showed no differences in dominance (>40% to the total biovolume of C. raciborskii between climate regions. C. raciborskii was able to dominate the phytoplankton in a wide range of light environments (euphotic zone = 1.5 to 5 m, euphotic zone/mixing zone ratio <0.5 to >1.5. Moreover, C. raciborskii was capable of dominating the phytoplankton at low temperatures (<15°C. Our experimental results showed that C. raciborskii growing in interaction was enhanced by the increase of the temperature and light intensity. C. raciborskii growth in high light intensities and at a wide range of temperatures, suggests that any advantage that this species may derive from climate change that favors its dominance in the phytoplankton is likely due to changes in the light environment rather than changes in

  19. ATP-binding cassette transporters of the multicellular cyanobacterium Anabaena sp. PCC 7120: a wide variety for a complex lifestyle.

    Science.gov (United States)

    Shvarev, Dmitry; Maldener, Iris

    2018-02-01

    Two hundred genes or 3% of the known or putative protein-coding genes of the filamentous freshwater cyanobacterium Anabaena sp. PCC 7120 encode domains of ATP-binding cassette (ABC) transporters. Detailed characterization of some of these transporters (14-15 importers and 5 exporters) has revealed their crucial roles in the complex lifestyle of this multicellular photoautotroph, which is able to differentiate specialized cells for nitrogen fixation. This review summarizes the characteristics of the ABC transporters of Anabaena sp. PCC 7120 known to date. © FEMS 2018. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Characterization of three putative xylulose 5-phosphate/fructose 6-phosphate phosphoketolases in the cyanobacterium Anabaena sp. PCC 7120.

    Science.gov (United States)

    Moriyama, Takashi; Tajima, Naoyuki; Sekine, Kohsuke; Sato, Naoki

    2015-01-01

    Xylulose 5-phosphate/fructose 6-phosphate phosphoketolase (Xfp) is a key enzyme in the central carbohydrate metabolism in heterofermentative bacteria, in which enzymatic property of Xfps is well characterized. This is not the case in other microbes. The cyanobacterium Anabaena sp. PCC 7120 possesses three putative genes encoding Xfp, all1483, all2567, and alr1850. We purified three putative Xfps as recombinant proteins. The results of gel filtration indicated that these proteins form homomultimer complex. All1483 and All2567 showed phosphoketolase activity, whereas Alr1850 did not show the activity. Kinetic analyses demonstrated that substrates, fructose 6-phosphate and inorganic phosphate, are cooperatively bound to enzymes positively and negatively, respectively.

  1. Genome Sequence and Composition of a Tolyporphin-Producing Cyanobacterium-Microbial Community

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Rebecca-Ayme; Zhang, Yunlong; Zhang, Ran; Williams, Philip G.; Lindsey, Jonathan S.; Miller, Eric S.; Nojiri, Hideaki

    2017-07-28

    ABSTRACT

    The cyanobacterial culture HT-58-2 was originally described as a strain ofTolypothrix nodosawith the ability to produce tolyporphins, which comprise a family of distinct tetrapyrrole macrocycles with reported efflux pump inhibition properties. Upon reviving the culture from what was thought to be a nonextant collection, studies of culture conditions, strain characterization, phylogeny, and genomics have been undertaken. Here, HT-58-2 was shown by 16S rRNA analysis to closely align withBrasilonemastrains and not withTolypothrixisolates. Light, fluorescence, and scanning electron microscopy revealed cyanobacterium filaments that are decorated with attached bacteria and associated with free bacteria. Metagenomic surveys of HT-58-2 cultures revealed a diversity of bacteria dominated byErythrobacteraceae, 97% of which arePorphyrobacterspecies. A dimethyl sulfoxide washing procedure was found to yield enriched cyanobacterial DNA (presumably by removing community bacteria) and sequence data sufficient for genome assembly. The finished, closed HT-58-2Cyano genome consists of 7.85 Mbp (42.6% G+C) and contains 6,581 genes. All genes for biosynthesis of tetrapyrroles (e.g., heme, chlorophylla, and phycocyanobilin) and almost all for cobalamin were identified dispersed throughout the chromosome. Among the 6,177 protein-encoding genes, coding sequences (CDSs) for all but two of the eight enzymes for conversion of glutamic acid to protoporphyrinogen IX also were found within one major gene cluster. The cluster also includes 10 putative genes (and one hypothetical gene) encoding proteins with

  2. Highly plastic genome of Microcystis aeruginosa PCC 7806, a ubiquitous toxic freshwater cyanobacterium

    Directory of Open Access Journals (Sweden)

    Latifi Amel

    2008-06-01

    Full Text Available Abstract Background The colonial cyanobacterium Microcystis proliferates in a wide range of freshwater ecosystems and is exposed to changing environmental factors during its life cycle. Microcystis blooms are often toxic, potentially fatal to animals and humans, and may cause environmental problems. There has been little investigation of the genomics of these cyanobacteria. Results Deciphering the 5,172,804 bp sequence of Microcystis aeruginosa PCC 7806 has revealed the high plasticity of its genome: 11.7% DNA repeats containing more than 1,000 bases, 6.8% putative transposases and 21 putative restriction enzymes. Compared to the genomes of other cyanobacterial lineages, strain PCC 7806 contains a large number of atypical genes that may have been acquired by lateral transfers. Metabolic pathways, such as fermentation and a methionine salvage pathway, have been identified, as have genes for programmed cell death that may be related to the rapid disappearance of Microcystis blooms in nature. Analysis of the PCC 7806 genome also reveals striking novel biosynthetic features that might help to elucidate the ecological impact of secondary metabolites and lead to the discovery of novel metabolites for new biotechnological applications. M. aeruginosa and other large cyanobacterial genomes exhibit a rapid loss of synteny in contrast to other microbial genomes. Conclusion Microcystis aeruginosa PCC 7806 appears to have adopted an evolutionary strategy relying on unusual genome plasticity to adapt to eutrophic freshwater ecosystems, a property shared by another strain of M. aeruginosa (NIES-843. Comparisons of the genomes of PCC 7806 and other cyanobacterial strains indicate that a similar strategy may have also been used by the marine strain Crocosphaera watsonii WH8501 to adapt to other ecological niches, such as oligotrophic open oceans.

  3. CRISPR interference (CRISPRi) for gene regulation and succinate production in cyanobacterium S. elongatus PCC 7942.

    Science.gov (United States)

    Huang, Chun-Hung; Shen, Claire R; Li, Hung; Sung, Li-Yu; Wu, Meng-Ying; Hu, Yu-Chen

    2016-11-15

    Cyanobacterium Synechococcus elongatus PCC 7942 holds promise for biochemical conversion, but gene deletion in PCC 7942 is time-consuming and may be lethal to cells. CRISPR interference (CRISPRi) is an emerging technology that exploits the catalytically inactive Cas9 (dCas9) and single guide RNA (sgRNA) to repress sequence-specific genes without the need of gene knockout, and is repurposed to rewire metabolic networks in various procaryotic cells. To employ CRISPRi for the manipulation of gene network in PCC 7942, we integrated the cassettes expressing enhanced yellow fluorescent protein (EYFP), dCas9 and sgRNA targeting different regions on eyfp into the PCC 7942 chromosome. Co-expression of dCas9 and sgRNA conferred effective and stable suppression of EYFP production at efficiencies exceeding 99%, without impairing cell growth. We next integrated the dCas9 and sgRNA targeting endogenous genes essential for glycogen accumulation (glgc) and succinate conversion to fumarate (sdhA and sdhB). Transcription levels of glgc, sdhA and sdhB were effectively suppressed with efficiencies depending on the sgRNA binding site. Targeted suppression of glgc reduced the expression to 6.2%, attenuated the glycogen accumulation to 4.8% and significantly enhanced the succinate titer. Targeting sdhA or sdhB also effectively downregulated the gene expression and enhanced the succinate titer ≈12.5-fold to ≈0.58-0.63 mg/L. These data demonstrated that CRISPRi-mediated gene suppression allowed for re-directing the cellular carbon flow, thus paving a new avenue to rationally fine-tune the metabolic pathways in PCC 7942 for the production of biotechnological products.

  4. Acidovorax lacteus sp. nov., isolated from a culture of a bloom-forming cyanobacterium (Microcystis sp.).

    Science.gov (United States)

    Chun, Seong-Jun; Cui, Yingshun; Ko, So-Ra; Lee, Hyung-Gwan; Srivastava, Ankita; Oh, Hee-Mock; Ahn, Chi-Yong

    2017-09-01

    A novel Gram-negative, rod-shaped and motile bacterial strain, designated strain M36 T , was isolated from a culture of a bloom-forming cyanobacterium, Microcystis sp., collected from a eutrophic lake in Korea. Its taxonomic position was investigated by using a polyphasic taxonomic approach. The isolate was found to grow aerobically at 15-42 °C (optimum 25 °C), pH 7.0-11.0 (optimum pH 8.0) and in the presence of 0-1.0% (w/v) NaCl (optimum 0% NaCl) on R2A medium. The phylogenetic analysis based on 16S rRNA gene sequences revealed that the strain M36 T is closely related to Acidovorax anthurii DSM 16745 T (98.1%), Acidovorax konjaci DSM 7481 T (97.7%) and Acidovorax avenae DSM 7227 T (97.0%) and also formed a clear phylogenetic lineage with other Acidovorax species. DNA-DNA relatedness between strain M36 T and the closely related species of the genus Acidovorax was <30%. The major fatty acid components identified included summed feature 3 (C 16:1 ω7c and/or C 16:1 ω6c), C 16:0 and summed feature 8 (C 18:0 ω7c and/or C 18:0 ω6c). The DNA G+C content of strain M36 T was determined to be 66.8 mol%. Based on above polyphasic evidence, strain M36 T is concluded to represent a new species of genus Acidovorax, for which the name Acidovorax lacteus sp. nov. is proposed. The type strain is M36 T (=KCTC 52220 T  = JCM 31890 T ).

  5. Dependence of the cyanobacterium Prochlorococcus on hydrogen peroxide scavenging microbes for growth at the ocean's surface.

    Directory of Open Access Journals (Sweden)

    J Jeffrey Morris

    2011-02-01

    Full Text Available The phytoplankton community in the oligotrophic open ocean is numerically dominated by the cyanobacterium Prochlorococcus, accounting for approximately half of all photosynthesis. In the illuminated euphotic zone where Prochlorococcus grows, reactive oxygen species are continuously generated via photochemical reactions with dissolved organic matter. However, Prochlorococcus genomes lack catalase and additional protective mechanisms common in other aerobes, and this genus is highly susceptible to oxidative damage from hydrogen peroxide (HOOH. In this study we showed that the extant microbial community plays a vital, previously unrecognized role in cross-protecting Prochlorococcus from oxidative damage in the surface mixed layer of the oligotrophic ocean. Microbes are the primary HOOH sink in marine systems, and in the absence of the microbial community, surface waters in the Atlantic and Pacific Ocean accumulated HOOH to concentrations that were lethal for Prochlorococcus cultures. In laboratory experiments with the marine heterotroph Alteromonas sp., serving as a proxy for the natural community of HOOH-degrading microbes, bacterial depletion of HOOH from the extracellular milieu prevented oxidative damage to the cell envelope and photosystems of co-cultured Prochlorococcus, and facilitated the growth of Prochlorococcus at ecologically-relevant cell concentrations. Curiously, the more recently evolved lineages of Prochlorococcus that exploit the surface mixed layer niche were also the most sensitive to HOOH. The genomic streamlining of these evolved lineages during adaptation to the high-light exposed upper euphotic zone thus appears to be coincident with an acquired dependency on the extant HOOH-consuming community. These results underscore the importance of (indirect biotic interactions in establishing niche boundaries, and highlight the impacts that community-level responses to stress may have in the ecological and evolutionary outcomes for co

  6. Using oxidized liquid and solid human waste as nutrients for Chlorella vulgaris and cyanobacterium Oscillatoria deflexa

    Science.gov (United States)

    Trifonov, Sergey V.; Kalacheva, Galina; Tirranen, Lyalya; Gribovskaya, Iliada

    At stationary terrestrial and space stations with closed and partially closed substance exchange not only plants, but also algae can regenerate atmosphere. Their biomass can be used for feeding Daphnia and Moina species, which, in their turn, serve as food for fish. In addition, it is possible to use algae for production of biological fuel. We suggested two methods of human waste mineralization: dry (evaporation with subsequent incineration in a muffle furnace) and wet (oxidation in a reactor using hydrogen peroxide). The research task was to prepare nutrient media for green alga Chlorella vulgaris and cyanobacterium Oscillatoria deflexa using liquid human waste mineralized by dry method, and to prepare media for chlorella on the basis of 1) liquid and 2) liquid and solid human waste mineralized by wet method. The algae were grown in batch culture in a climate chamber with the following parameters: illumination 7 klx, temperature 27-30 (°) C, culture density 1-2 g/l of dry weight. The control for chlorella was Tamiya medium, pH-5, and for oscillstoria — Zarrouk medium, pH-10. Maximum permissible concentrations of NaCl, Cl, urea (NH _{2}) _{2}CO, and native urine were established for algae. Missing ingredients (such as salts and acids) for experimental nutrient media were determined: their addition made it possible to obtain the biomass production not less than that in the control. The estimation was given of the mineral and biochemical composition of algae grown on experimental media. Microbiological test revealed absence of foreign microbial flora in experimental cultures.

  7. Comparative genomic analyses of the cyanobacterium, Lyngbya aestuarii BL J, a powerful hydrogen producer.

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    Ankita eKothari

    2013-12-01

    Full Text Available The filamentous, non-heterocystous cyanobacterium Lyngbya aestuarii is an important contributor to marine intertidal microbial mats system worldwide. The recent isolate L. aestuarii BL J, is an unusually powerful hydrogen producer. Here we report a morphological, ultrastructural and genomic characterization of this strain to set the basis for future systems studies and applications of this organism. The filaments contain circa 17 μm wide trichomes, composed of stacked disk-like short cells (2 μm long, encased in a prominent, laminated exopolysaccharide sheath. Cellular division occurs by transversal centripetal growth of cross-walls, where several rounds of division proceed simultaneously. Filament division occurs by cell self-immolation of one or groups of cells (necridial cells at the breakage point. Short, sheath-less, motile filaments (hormogonia are also formed. Morphologically and phylogenetically L. aestuarii belongs to a clade of important cyanobacteria that include members of the marine Trichodesmiun and Hydrocoleum genera, as well as terrestrial Microcoleus vaginatus strains, and alkalyphilic strains of Arthrospira. A draft genome of strain BL J was compared to those of other cyanobacteria in order to ascertain some of its ecological constraints and biotechnological potential. The genome had an average GC content of 41.1 %. Of the 6.87 Mb sequenced, 6.44 Mb was present as large contigs (>10,000 bp. It contained 6515 putative protein-encoding genes, of which, 43 % encode proteins of known functional role, 26 % corresponded to proteins with domain or family assignments, 19.6 % encode conserved hypothetical proteins, and 11.3 % encode apparently unique hypothetical proteins. The strain’s genome reveals its adaptations to a life of exposure to intense solar radiation and desiccation. It likely employs the storage compounds, glycogen and cyanophycin but no polyhydroxyalkanoates, and can produce the osmolytes, trehalose and glycine

  8. Regulation of Three Nitrogenase Gene Clusters in the Cyanobacterium Anabaena variabilis ATCC 29413

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    Teresa Thiel

    2014-12-01

    Full Text Available The filamentous cyanobacterium Anabaena variabilis ATCC 29413 fixes nitrogen under aerobic conditions in specialized cells called heterocysts that form in response to an environmental deficiency in combined nitrogen. Nitrogen fixation is mediated by the enzyme nitrogenase, which is very sensitive to oxygen. Heterocysts are microxic cells that allow nitrogenase to function in a filament comprised primarily of vegetative cells that produce oxygen by photosynthesis. A. variabilis is unique among well-characterized cyanobacteria in that it has three nitrogenase gene clusters that encode different nitrogenases, which function under different environmental conditions. The nif1 genes encode a Mo-nitrogenase that functions only in heterocysts, even in filaments grown anaerobically. The nif2 genes encode a different Mo-nitrogenase that functions in vegetative cells, but only in filaments grown under anoxic conditions. An alternative V-nitrogenase is encoded by vnf genes that are expressed only in heterocysts in an environment that is deficient in Mo. Thus, these three nitrogenases are expressed differentially in response to environmental conditions. The entire nif1 gene cluster, comprising at least 15 genes, is primarily under the control of the promoter for the first gene, nifB1. Transcriptional control of many of the downstream nif1 genes occurs by a combination of weak promoters within the coding regions of some downstream genes and by RNA processing, which is associated with increased transcript stability. The vnf genes show a similar pattern of transcriptional and post-transcriptional control of expression suggesting that the complex pattern of regulation of the nif1 cluster is conserved in other cyanobacterial nitrogenase gene clusters.

  9. Physical and chemical processes promoting dominance of the toxic cyanobacterium Cylindrospermopsis raciborskii

    Science.gov (United States)

    Burford, Michele A.; Davis, Timothy W.

    2011-07-01

    The freshwater cyanobacterium, Cylindrospermopsis raciborskii (Wo'oszyńska) Seenayya and Subba Raju is a common species in lakes and reservoirs globally. In some areas of the world it can produce cyto- and hepatotoxins (cylindrospermopsins, saxitoxins), making blooms of this species a serious health concern for humans. In the last 10-15 years, there has been a considerable body of research conducted on the ecology, physiology and toxin production of this species and this paper reviews these studies with a focus on the cylindrospermopsin (CYN)-producing strains. C. raciborskii has low light requirements, close to neutral buoyancy, and a wide temperature tolerance, giving it the capacity to grow in many lentic waterbodies. It also has a flexible strategy with respect to nitrogen (N) utilisation; being able to switch between utilising fixed and atmospheric N as sources of N fluctuate. Additionally this species has a high phosphate (DIP) affinity and storage capacity. Like many cyanobacteria, it also has the capacity to use dissolved organic phosphorus (DOP). Changes in nutrient concentrations, light levels and temperature have also been found to affect production of the toxin CYN by this species. However, optimal toxin production does not necessarily occur when growth rates are optimal. Additionally, different strains of C. raciborskii vary in their cell quota of CYN, making it difficult to predict toxin concentrations, based on C. raciborskii cell densities. In summary, the ecological flexibility of this organism means that controlling blooms of C. raciborskii is a difficult undertaking. However, improved understanding of factors promoting the species and toxin production by genetically capable strains will lead to improved predictive models of blooms.

  10. Isolation and characterization of the small subunit of the uptake hydrogenase from the cyanobacterium Nostoc punctiforme.

    Science.gov (United States)

    Raleiras, Patrícia; Kellers, Petra; Lindblad, Peter; Styring, Stenbjörn; Magnuson, Ann

    2013-06-21

    In nitrogen-fixing cyanobacteria, hydrogen evolution is associated with hydrogenases and nitrogenase, making these enzymes interesting targets for genetic engineering aimed at increased hydrogen production. Nostoc punctiforme ATCC 29133 is a filamentous cyanobacterium that expresses the uptake hydrogenase HupSL in heterocysts under nitrogen-fixing conditions. Little is known about the structural and biophysical properties of HupSL. The small subunit, HupS, has been postulated to contain three iron-sulfur clusters, but the details regarding their nature have been unclear due to unusual cluster binding motifs in the amino acid sequence. We now report the cloning and heterologous expression of Nostoc punctiforme HupS as a fusion protein, f-HupS. We have characterized the anaerobically purified protein by UV-visible and EPR spectroscopies. Our results show that f-HupS contains three iron-sulfur clusters. UV-visible absorption of f-HupS has bands ∼340 and 420 nm, typical for iron-sulfur clusters. The EPR spectrum of the oxidized f-HupS shows a narrow g = 2.023 resonance, characteristic of a low-spin (S = ½) [3Fe-4S] cluster. The reduced f-HupS presents complex EPR spectra with overlapping resonances centered on g = 1.94, g = 1.91, and g = 1.88, typical of low-spin (S = ½) [4Fe-4S] clusters. Analysis of the spectroscopic data allowed us to distinguish between two species attributable to two distinct [4Fe-4S] clusters, in addition to the [3Fe-4S] cluster. This indicates that f-HupS binds [4Fe-4S] clusters despite the presence of unusual coordinating amino acids. Furthermore, our expression and purification of what seems to be an intact HupS protein allows future studies on the significance of ligand nature on redox properties of the iron-sulfur clusters of HupS.

  11. DL-7-azatryptophan and citrulline metabolism in the cyanobacterium Anabaena sp. strain 1F

    International Nuclear Information System (INIS)

    Chen, C.H.; Van Baalen, C.; Tabita, F.R.

    1987-01-01

    An alternative route for the primary assimilation of ammonia proceeds via glutamine synthetase-carbamyl phosphate synthetase and its inherent glutaminase activity in Anabaena sp. strain 1F, a marine filamentous, heterocystous cyanobacterium. Evidence for the presence of this possible alternative route to glutamate was provided by the use of amino acid analogs as specific enzyme inhibitors, enzymological studies, and radioistopic labeling experiments. The amino acid pool patterns of continuous cultures of Anabaena sp. strain 1F were markedly influenced by the nitrogen source. A relatively high concentration of glutamate was maintained in the amino acid pools of all cultures irrespective of the nitrogen source, reflecting the central role of glutamate in nitrogen metabolism. The addition of 1.0 microM azaserine increased the intracellular pools of glutamate and glutamine. All attempts to detect any enzymatic activity for glutamate synthase by measuring the formation of L-[ 14 C]glutamate from 2-keto-[1- 14 C]glutarate and glutamine failed. The addition of 10 microM DL-7-azatryptophan caused a transient accumulation of intracellular citrulline and alanine which was not affected by the presence of chloramphenicol. The in vitro activity of carbamyl phosphate synthetase and glutaminase increased severalfold in the presence of azatryptophan. Results from radioisotopic labeling experiments with [ 14 C]bicarbonate and L-[1- 14 C]ornithine also indicated that citrulline was formed via carbamyl phosphate synthetase and ornithine transcarbamylase. In addition to its effects on nitrogen metabolism, azatryptophan also affected carbon metabolism by inhibiting photosynthetic carbon assimilation and photosynthetic oxygen evolution

  12. Evidence regarding the possible role of c-phycoerythrin in ultraviolet-B tolerance in a thermophilic cyanobacterium

    International Nuclear Information System (INIS)

    Wingard, C.E.; Castenholz, R.W.

    1997-01-01

    It was recently reported that a strain of Nostoc spongiaeforme (cyanobacteria) with the photopigment c-phycoerythrin (c-PE) may be more tolerant of the adverse effects of UVB radiation than the same strain lacking c-PE due to chromatic adaptation (CA) (Tyagi et al., Photochem. Photobiol. 55, 401-407, 1992). It was proposed that this increased UVB tolerance may be due to the presence of c-PE, perhaps as a function of the ability of strains with c-PE to chromatically adapt. We tested the role of c-PE in UVB tolerance by comparing the short- and long-term effects of UVB exposure on photosynthesis pigmentation and the protein contents of four experimental cultures of the thermophilic cyanobacterium Oscillatoria cf. amphigranulata. These cultures consisted of a wild-type strain that produces c-PE, a green pigment variant (subcloned from the parent wild-type strain) incapable of producing c-PE and two chromatically adapted color forms of the wild-type strain that varied with regard to their total c-PE content. There were no significant results suggesting a role for c-PE in UVB tolerance. It is concluded that the photopigment c-PE does not confer enhanced resistance to the deleterious effects of UVB radiation on photosynthesis in this cyanobacterium. (author)

  13. Characterization of the coccoid cyanobacterium Myxosarcina sp. KIOST-1 isolated from mangrove forest in Chuuk State, Federated States of Micronesia

    Science.gov (United States)

    Kim, Ji Hyung; Lee, JunMo; Affan, Md-Abu; Lee, Dae-Won; Kang, Do-Hyung

    2017-09-01

    Mangrove forests are known to be inhabited by diverse symbiotic cyanobacterial communities that are capable of N2 fixation. To investigate its biodiversity, root sediments were collected from a mangrove forest in Chuuk State, Federated States of Micronesia (FSM), and an entangled yellow-brown coccoid cyanobacterium was isolated. The isolated cyanobacterium was reproduced by multiple fission and eventually produced baeocytes. Phylogenetic analysis revealed that the isolate was most similar to the genera Myxosarcina and Chroococcidiopsis in the order Pleurocapsales. Compositions of protein, lipid and carbohydrate in the cyanobacterial cells were estimated to be 19.4 ± 0.1%, 18.8 ± 0.4% and 31.5 ± 0.1%, respectively. Interestingly, total fatty acids in the isolate were mainly composed of saturated fatty acids and monounsaturated fatty acids, whereas polyunsaturated fatty acids were not detected. Based on the molecular and biochemical characteristics, the isolate was finally classified in the genus Myxosarcina, and designated as Myxosarcina sp. KIOST-1. These results will contribute to better understanding of cyanobacterial biodiversity in the mangrove forest in FSM as well as the genus Myxosarcina, and also will allow further exploitation of its biotechnological potential on the basis of its cellular characteristics.

  14. Enhancement of human adaptive immune responses by administration of a high-molecular-weight polysaccharide extract from the cyanobacterium Arthrospira platensis

    DEFF Research Database (Denmark)

    Pedersen, Morten Løbner; Walsted, Anette; Larsen, Rune

    2008-01-01

    The effect of consumption of Immulina, a high-molecular-weight polysaccharide extract from the cyanobacterium Arthrospira platensis, on adaptive immune responses was investigated by evaluation of changes in leukocyte responsiveness to two foreign recall antigens, Candida albicans (CA) and tetanus...

  15. Biotic factors in induced defence revisited: cell aggregate formation in the toxic cyanobacterium Microcystis aeruginosa PCC 7806 is triggered by spent Daphnia medium and disrupted cells

    NARCIS (Netherlands)

    Becker, S.

    2010-01-01

    Bioassays with the toxic cyanobacterium Microcystis aeruginosa PCC 7806, its non-toxic mutant ΔmcyB, and Daphnia magna as grazer were used to evaluate biotic factors in induced defence, in particular cyanobacterial and grazer-released info-chemicals. Three main questions were addressed in this

  16. Effects of microcystin-free and Microcystin containing strains of the cyanobacterium Microcystis aeruginosa on growth of the grazer Daphnia magna

    NARCIS (Netherlands)

    Lürling, M.

    2003-01-01

    Harmful effects of the common bloom-forming cyanobacterium Microcystis aeruginosa on the grazer Daphnia have been explained from morphological features, nutritional insufficiency, and the production of toxins called microcystins. The effects of four M. aeruginosa strains, including one free of

  17. Systems analysis of ethanol production in the genetically engineered cyanobacteriumSynechococcussp. PCC 7002.

    Science.gov (United States)

    Kopka, Joachim; Schmidt, Stefanie; Dethloff, Frederik; Pade, Nadin; Berendt, Susanne; Schottkowski, Marco; Martin, Nico; Dühring, Ulf; Kuchmina, Ekaterina; Enke, Heike; Kramer, Dan; Wilde, Annegret; Hagemann, Martin; Friedrich, Alexandra

    2017-01-01

    Future sustainable energy production can be achieved using mass cultures of photoautotrophic microorganisms, which are engineered to synthesize valuable products directly from CO 2 and sunlight. As cyanobacteria can be cultivated in large scale on non-arable land, these phototrophic bacteria have become attractive organisms for production of biofuels. Synechococcus sp. PCC 7002, one of the cyanobacterial model organisms, provides many attractive properties for biofuel production such as tolerance of seawater and high light intensities. Here, we performed a systems analysis of an engineered ethanol-producing strain of the cyanobacterium Synechococcus sp. PCC 7002, which was grown in artificial seawater medium over 30 days applying a 12:12 h day-night cycle. Biosynthesis of ethanol resulted in a final accumulation of 0.25% (v/v) ethanol, including ethanol lost due to evaporation. The cultivation experiment revealed three production phases. The highest production rate was observed in the initial phase when cells were actively growing. In phase II growth of the producer strain stopped, but ethanol production rate was still high. Phase III was characterized by a decrease of both ethanol production and optical density of the culture. Metabolomics revealed that the carbon drain due to ethanol diffusion from the cell resulted in the expected reduction of pyruvate-based intermediates. Carbon-saving strategies successfully compensated the decrease of central intermediates of carbon metabolism during the first phase of fermentation. However, during long-term ethanol production the producer strain showed clear indications of intracellular carbon limitation. Despite the decreased levels of glycolytic and tricarboxylic acid cycle intermediates, soluble sugars and even glycogen accumulated in the producer strain. The changes in carbon assimilation patterns are partly supported by proteome analysis, which detected decreased levels of many enzymes and also revealed the stress

  18. Backbone dynamics of reduced plastocyanin from the cyanobacterium Anabaena variabilis: Regions involved in electron transfer have enhanced mobility

    DEFF Research Database (Denmark)

    Ma, L.X.; Hass, M.A.S.; Vierick, N.

    2003-01-01

    The dynamics of the backbone of the electron-transfer protein plastocyanin from the cyanobacterium Anabaena variabilis were determined from the N-15 and C-13(alpha) R-1 and R-2) relaxation rates and steady-state [H-1]-N-15 and [H-1]-C-13 nuclear Overhauser effects (NOEs) using the model......-free approach. The C-13 relaxation studies were performed using C-13 in natural abundance. Overall, it is found that the protein backbone is rigid. However, the regions that are important for the function of the protein show moderate mobility primarily on the microsecond to millisecond time scale. These regions...... are the "northern" hydrophobic site close to the metal site, the metal site itself, and the "eastern" face of the molecule. In particular, the mobility of the latter region is interesting in light of recent findings indicating that residues also on the eastern face of plastocyanins from prokaryotes are important...

  19. Phosphorus addition reverses the positive effect of zebra mussels (Dreissena polymorpha) on the toxic cyanobacterium, Microcystis aeruginosa.

    Science.gov (United States)

    Sarnelle, Orlando; White, Jeffrey D; Horst, Geoffrey P; Hamilton, Stephen K

    2012-07-01

    We tested the hypothesis that zebra mussels (Dreissena polymorpha) have positive effects on the toxin-producing cyanobacterium, Microcystis aeruginosa, at low phosphorus (P) concentrations, but negative effects on M. aeruginosa at high P, with a large-scale enclosure experiment in an oligotrophic lake. After three weeks, mussels had a significantly positive effect on M. aeruginosa at ambient P (total phosphorus, TP ∼10 μg L⁻¹), and a significantly negative effect at high P (simulating a TP of ∼40 μg L⁻¹ in lakes). Positive and negative effects were strong and very similar in magnitude. Thus, we were able to ameliorate a negative effect of Dreissena invasion on water quality (i.e., promotion of Microcystis) by adding P to water from an oligotrophic lake. Our results are congruent with many field observations of Microcystis response to Dreissena invasion across ecosystems of varying P availability. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Microenvironmental Ecology of the Chlorophyll b-containing Symbiotic Cyanobacterium Prochloron in the Didemnid Ascidian Lissoclinum patella

    Directory of Open Access Journals (Sweden)

    Michael eKühl

    2012-11-01

    Full Text Available The discovery of the cyanobacterium Prochloron was the first finding of a bacterial oxyphototroph with chlorophyll (Chl b, in addition to Chl a. It was first described as Prochloron didemni but a number of clades have since been described. Prochloron is a conspicuously large (7-25 µm unicellular cyanobacterium living in a symbiotic relationship, primarily with (sub- tropical didemnid ascidians; it has resisted numerous cultivation attempts and appears truly obligatory symbiotic. Recently, a Prochloron draft genome was published, revealing no lack of metabolic genes that could explain the apparent inability to reproduce and sustain photosynthesis in a free-living stage. Possibly, the unsuccessful cultivation is partly due to a lack of knowledge about the microenvironmental conditions and ecophysiology of Prochloron in its natural habitat. We used microsensors, variable chlorophyll fluorescence imaging and imaging of O2 and pH to obtain a detailed insight to the microenvironmental ecology and photobiology of Prochloron in hospite in the didemnid ascidian Lissoclinum patella. The microenvironment within ascidians is characterized by steep gradients of light and chemical parameters that change rapidly with varying irradiances. The interior zone of the ascidians harboring Prochloron thus became anoxic and acidic within a few min of darkness, while the same zone exhibited O2 super-saturation and strongly alkaline pH after a few min of illumination. Photosynthesis showed lack of photoinhibition even at high irradiances equivalent to full sunlight, and photosynthesis recovered rapidly after periods of anoxia. We discuss these new insights on the ecological niche of Prochloron and possible interactions with its host and other microbes in light of its recently published genome and a recent study of the overall microbial diversity and metagenome of L. patella.

  1. Changes in gene expression, cell physiology and toxicity of the harmful cyanobacterium Microcystis aeruginosa at elevated CO2

    Directory of Open Access Journals (Sweden)

    Giovanni eSandrini

    2015-05-01

    Full Text Available Rising CO2 concentrations may have large effects on aquatic microorganisms. In this study, we investigated how elevated pCO2 affects the harmful freshwater cyanobacterium Microcystis aeruginosa. This species is capable of producing dense blooms and hepatotoxins called microcystins. Strain PCC 7806 was cultured in chemostats that were shifted from low to high pCO2 conditions. This resulted in a transition from a C-limited to a light-limited steady state, with a ~2.7 fold increase of the cyanobacterial biomass and ~2.5 fold more microcystin per cell. Cells increased their chlorophyll a and phycocyanin content, and raised their PSI/PSII ratio at high pCO2. Surprisingly, cells had a lower dry weight and contained less carbohydrates, which might be an adaptation to improve the buoyancy of Microcystis when light becomes more limiting at high pCO2. Only 234 of the 4,691 genes responded to elevated pCO2. For instance, expression of the carboxysome, RuBisCO, photosystem and C metabolism genes did not change significantly, and only a few N assimilation genes were expressed differently. The lack of large-scale changes in the transcriptome could suit a buoyant species that lives in eutrophic lakes with strong CO2 fluctuations very well. However, we found major responses in inorganic carbon uptake. At low pCO2, cells were mainly dependent on bicarbonate uptake, whereas at high pCO2 gene expression of the bicarbonate uptake systems was down-regulated and cells shifted to CO2 and low-affinity bicarbonate uptake. These results show that the need for high-affinity bicarbonate uptake systems ceases at elevated CO2. Moreover, the combination of an increased cyanobacterial abundance, improved buoyancy, and higher toxin content per cell indicates that rising atmospheric CO2 levels may increase the problems associated with the harmful cyanobacterium Microcystis in eutrophic lakes.

  2. The Cyanobacterium Cylindrospermopsis raciborskii (CYRF-01 Responds to Environmental Stresses with Increased Vesiculation Detected at Single-Cell Resolution

    Directory of Open Access Journals (Sweden)

    Victor Zarantonello

    2018-02-01

    Full Text Available Secretion of membrane-limited vesicles, collectively termed extracellular vesicles (EVs, is an important biological process of both eukaryotic and prokaryotic cells. This process has been observed in bacteria, but remains to be better characterized at high resolution in cyanobacteria. In the present work, we address the release of EVs by Cylindrospermopsis raciborskii (CYRF-01, a filamentous bloom-forming cyanobacterium, exposed to environmental stressors. First, non-axenic cultures of C. raciborskii (CYRF-01 were exposed to ultraviolet radiation (UVA + UVB over a 6 h period, which is known to induce structural damage to this species. Second, C. raciborskii was co-cultured in interaction with another cyanobacterium species, Microcystis aeruginosa (MIRF-01, over a 24 h period. After the incubation times, cell density and viability were analyzed, and samples were processed for transmission electron microscopy (TEM. Our ultrastructural analyses revealed that C. raciborskii constitutively releases EVs from the outer membrane during its normal growth and amplifies such ability in response to environmental stressors. Both situations induced significant formation of outer membrane vesicles (OMVs by C. raciborskii compared to control cells. Quantitative TEM revealed an increase of 48% (UV and 60% (interaction in the OMV numbers compared to control groups. Considering all groups, the OMVs ranged in size from 20 to 300 nm in diameter, with most OMVs showing diameters between 20 and 140 nm. Additionally, we detected that OMV formation is accompanied by phosphatidylserine exposure, a molecular event also observed in EV-secreting eukaryotic cells. Altogether, we identified for the first time that C. raciborskii has the competence to secrete OMVs and that under different stress situations the genesis of these vesicles is increased. The amplified ability of cyanobacteria to release OMVs may be associated with adaptive responses to changes in environmental

  3. Proteomic strategy for the analysis of the polychlorobiphenyl-degrading cyanobacterium Anabaena PD-1 exposed to Aroclor 1254.

    Directory of Open Access Journals (Sweden)

    Hangjun Zhang

    Full Text Available The cyanobacterium Anabaena PD-1, which was originally isolated from polychlorobiphenyl (PCB-contaminated paddy soils, has capabilities for dechlorinatin and for degrading the commercial PCB mixture Aroclor 1254. In this study, 25 upregulated proteins were identified using 2D electrophoresis (2-DE coupled with matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS. These proteins were involved in (i PCB degradation (i.e., 3-chlorobenzoate-3,4-dioxygenase; (ii transport processes [e.g., ATP-binding cassette (ABC transporter substrate-binding protein, amino acid ABC transporter substrate-binding protein, peptide ABC transporter substrate-binding protein, putrescine-binding protein, periplasmic solute-binding protein, branched-chain amino acid uptake periplasmic solute-binding protein, periplasmic phosphate-binding protein, phosphonate ABC transporter substrate-binding protein, and xylose ABC transporter substrate-binding protein]; (iii energetic metabolism (e.g., methanol/ethanol family pyrroloquinoline quinone (PQQ-dependent dehydrogenase, malate-CoA ligase subunit beta, enolase, ATP synthase β subunit, FOF1 ATP synthase subunit beta, ATP synthase α subunit, and IMP cyclohydrolase; (iv electron transport (cytochrome b6f complex Fe-S protein; (v general stress response (e.g., molecular chaperone DnaK, elongation factor G, and translation elongation factor thermostable; (vi carbon metabolism (methanol dehydrogenase and malate-CoA ligase subunit beta; and (vii nitrogen reductase (nitrous oxide reductase. The results of real-time polymerase chain reaction showed that the genes encoding for dioxygenase, ABC transporters, transmembrane proteins, electron transporter, and energetic metabolism proteins were significantly upregulated during PCB degradation. These genes upregulated by 1.26- to 8.98-fold. These findings reveal the resistance and adaptation of cyanobacterium to the presence of PCBs, shedding light on the

  4. Photosystem Trap Energies and Spectrally-Dependent Energy-Storage Efficiencies in the Chl d-Utilizing Cyanobacterium, Acaryochloris Marina

    Science.gov (United States)

    Mielke, Steven P.; Kiang, Nancy Y.; Blankenship, Robert E.; Mauzerall, David

    2012-01-01

    Acaryochloris marina is the only species known to utilize chlorophyll (Chl) d as a principal photopigment. The peak absorption wavelength of Chl d is redshifted approx. 40 nm in vivo relative to Chl a, enabling this cyanobacterium to perform oxygenic phototrophy in niche environments enhanced in far-red light. We present measurements of the in vivo energy-storage (E-S) efficiency of photosynthesis in A. marina, obtained using pulsed photoacoustics (PA) over a 90-nm range of excitation wavelengths in the red and far-red. Together with modeling results, these measurements provide the first direct observation of the trap energies of PSI and PSII, and also the photosystem-specific contributions to the total E-S efficiency. We find the maximum observed efficiency in A. marina (40+/-1% at 735 nm) is higher than in the Chl a cyanobacterium Synechococcus leopoliensis (35+/-1% at 690 nm). The efficiency at peak absorption wavelength is also higher in A. marina (36+/-1% at 710 nm vs. 31+/-1% at 670 nm). In both species, the trap efficiencies are approx. 40% (PSI) and approx. 30% (PSII). The PSI trap in A. marina is found to lie at 740+/-5 nm, in agreement with the value inferred from spectroscopic methods. The best fit of the model to the PA data identifies the PSII trap at 723+/-3 nm, supporting the view that the primary electron-donor is Chl d, probably at the accessory (ChlD1) site. A decrease in efficiency beyond the trap wavelength, consistent with uphill energy transfer, is clearly observed and fit by the model. These results demonstrate that the E-S efficiency in A. marina is not thermodynamically limited, suggesting that oxygenic photosynthesis is viable in even redder light environments.

  5. pH-dependent activation of Streptomyces hygroscopicus transglutaminase mediated by intein.

    Science.gov (United States)

    Du, Kun; Liu, Zhongmei; Cui, Wenjing; Zhou, Li; Liu, Yi; Du, Guocheng; Chen, Jian; Zhou, Zhemin

    2014-01-01

    Microbial transglutaminase (MTG) from Streptomyces is naturally secreted as a zymogen (pro-MTG), which is then activated by the removal of its N-terminal proregion by additional proteases. Inteins are protein-intervening sequences that catalyze protein splicing without cofactors. In this study, a pH-dependent Synechocystis sp. strain PCC6803 DnaB mini-intein (SDB) was introduced into pro-MTG to simplify its activation process by controlling pH. The recombinant protein (pro-SDB-MTG) was obtained, and the activation process was determined to take 24 h at pH 7 in vitro. To investigate the effect of the first residue in MTG on the activity and the cleavage time, two variants, pro-SDB-MTG(D1S) and pro-SDB-MTG(ΔD1), were expressed, and the activation time was found to be 6 h and 30 h, respectively. The enzymatic property and secondary structure of the recombinant MTG and two variants were similar to those of the wild type, indicating that the insertion of mini-intein did not affect the function of MTG. This insignificant effect was further illustrated by molecular dynamics simulations. This study revealed a controllable and effective strategy to regulate the activation process of pro-MTG mediated by a mini-intein, and it may have great potential for industrial MTG production.

  6. A Miniaturized Escherichia coli Green Light Sensor with High Dynamic Range.

    Science.gov (United States)

    Ong, Nicholas T; Tabor, Jeffrey J

    2018-02-08

    Genetically engineered photoreceptors enable unrivaled control over gene expression. Previously, we ported the Synechocystis PCC 6803 CcaSR two-component system, which is activated by green light and deactivated by red, into Escherichia coli, resulting in a sensor with a sixfold dynamic range. Later, we optimized pathway protein expression levels and the output promoter sequence to decrease transcriptional leakiness and to increase the dynamic range to approximately 120-fold. These CcaSR v 1.0 and v 2.0 systems have been used for precise quantitative, temporal, and spatial control of gene expression for a variety of applications. Recently, other workers deleted two PAS domains of unknown function from the CcaS sensor histidine kinase in a system similar to CcaSR v 1.0. Here we apply these deletions to CcaSR v 2.0, resulting in a v 3.0 light sensor with an output four times less leaky and a dynamic range of nearly 600-fold. We demonstrate that the PAS domain deletions have no deleterious effect on CcaSR green light sensitivity or response dynamics. CcaSR v 3.0 is the best-performing engineered bacterial green light sensor available, and should have broad applications in fundamental and synthetic biology studies. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Study on production of useful metabolites by development of advanced cell culture techniques using radiation

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Byung Yeoup; Kim, Jin Hong; Lee, Seung Sik; Kim, Jae Sung; An, Byung Chull; Moon, Yu Ran; Lee, Eun Mi; Lee, Min Hee; Lee, Jae Tack [KAERI, Daejeon (Korea, Republic of)

    2010-02-15

    The purpose of this project is improvement of investigation, materialization and evaluation techniques on effectiveness for functional natural compounds throughout development of tissue/cell culture techniques for mass production of useful metabolites using radiation. Research scope includes 1) Development of a technique for radiation tissue and cell culture, 2) Database construction for radiation response in plants and radiation effects, 3) Construction of general-purpose national based techniques of cell culture technique using radiation. Main results are as follow: mass culture of the adventitious roots of mountain ginseng (Panax ginseng C. A. Meyer) roots using rare earth elements in bioreactor: characterization of a transcription factor EoP gene from centipedegrass and the transcription regulation of LexA from Synechocystis sp PCC6803 and E. coli: identification of gamma-ray induced hydrogenase synthesis in hox gene transformed E. coli: transformation and the selection of the EoP transgene from Arabidopsis, rice and lettuce: Identification of the maysin and maysin derivatives in centipedegrass: characterization of gamma-ray induced color change in Taxus cuspidata: verification of the expression of antioxidant proteins (POD, APX and CAT) to gamma-ray in Arabidopsis: comparison of the response of the expression level to gamma-ray or H{sub 2}O{sub 2} in Arabidopsis; verification of the responses and effects to gamma-ray from plants (analysis of NPQ and ROS levels): the development method for rapidly enhancing maysin content of centipede grass; establishment of mass culture system for red beet

  8. In silico analysis and experimental validation of lipoprotein and novel Tat signal peptides processing in Anabaena sp. PCC7120.

    Science.gov (United States)

    Kumari, Sonika; Chaurasia, Akhilesh Kumar

    2015-12-01

    Signal peptide (SP) plays a pivotal role in protein translocation. Lipoprotein- and twin arginine translocase (Tat) dependent signal peptides were studied in All3087, a homolog of competence protein of Synechocystis PCC6803 and in two putative alkaline phosphatases (ALPs, Alr2234 and Alr4976), respectively. In silico analysis of All3087 is shown to possess the characteristics feature of competence proteins such as helix-hairpin-helix, N and C-terminal HKD endonuclease domain, calcium binding domain and N-terminal lipoprotein signal peptide. The SP recognition-cleavage site in All3087 was predicted (AIA-AC) using SignalP while further in-depth analysis using Pred-Lipo and WebLogo analysis for consensus sequence showed it as IAA-C. Activities of putative ALPs were confirmed by heterologous overexpression, activity assessment and zymogram analysis. ALP activity in Anabaena remains cell bound in log-phase, but during late log/stationary phase, an enhanced ALP activity was detected in extracellular milieu. The enhancement of ALP activity during stationary phase was not only due to inorganic phosphate limitation but also contributed by the presence of novel bipartite Tat-SP. The Tat signal transported the folded active ALPs to the membrane, followed by anchoring into the membrane and successive cleavage enabling transportation of the ALPs to the extracellular milieu, because of bipartite architecture and processing of transit Tat-SP.

  9. Quantitative analysis of fatty-acid-based biofuels produced by wild-type and genetically engineered cyanobacteria by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Guan, Wenna; Zhao, Hui; Lu, Xuefeng; Wang, Cong; Yang, Menglong; Bai, Fali

    2011-11-11

    Simple and rapid quantitative determination of fatty-acid-based biofuels is greatly important for the study of genetic engineering progress for biofuels production by microalgae. Ideal biofuels produced from biological systems should be chemically similar to petroleum, like fatty-acid-based molecules including free fatty acids, fatty acid methyl esters, fatty acid ethyl esters, fatty alcohols and fatty alkanes. This study founded a gas chromatography-mass spectrometry (GC-MS) method for simultaneous quantification of seven free fatty acids, nine fatty acid methyl esters, five fatty acid ethyl esters, five fatty alcohols and three fatty alkanes produced by wild-type Synechocystis PCC 6803 and its genetically engineered strain. Data obtained from GC-MS analyses were quantified using internal standard peak area comparisons. The linearity, limit of detection (LOD) and precision (RSD) of the method were evaluated. The results demonstrated that fatty-acid-based biofuels can be directly determined by GC-MS without derivation. Therefore, rapid and reliable quantitative analysis of fatty-acid-based biofuels produced by wild-type and genetically engineered cyanobacteria can be achieved using the GC-MS method founded in this work. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Bioavailable nitrate detection in water by an immobilized luminescent cyanobacterial reporter strain.

    Science.gov (United States)

    Mbeunkui, F; Richaud, C; Etienne, A-L; Schmid, R D; Bachmann, T T

    2002-11-01

    Cyanobacteria are a major group of photosynthetic bacteria that can accumulate in surface water as so-called "blooms" in response to environmental factors such as temperature, light and certain nutrients such as N, P, and Fe. Some species of cyanobacteria produce toxins, causing a considerable danger for human and livestock health. As a consequence, monitoring of bloom formation and toxin production of drinking water supplies has become a major concern. To enable prediction and monitoring of cyanobacterial blooms, tools to detect nutrient bioavailability in water would be advantageous. A whole-cell biosensor was developed for monitoring nitrate (NO(3-)) bioavailability in aquatic ecosystems using the recombinant bioluminescent cyanobacterial strain Synechocystis PCC 6803 harboring an insertion of a luxAB-kmr fusion with nblA1 in its chromosomal DNA, leading to PnblA::luxAB-kmr. This reporter strain was designated N1LuxKm. Cells were immobilized in microtiter plates and showed a dose-dependent response to nitrate deprivation. The resultant CyanoSensor could detect nitrate in the 4-100 micro M concentration range after a sample incubation time of 10 h under continuous illumination (50 micro E m(-2) s(-1)). The optimal temperature for sensor operation was 29 degrees C and the immobilized biosensor could be stored at 4 degrees C in dark for about 1 month without significant loss of sensitivity.

  11. Determination of the Glycogen Content in Cyanobacteria.

    Science.gov (United States)

    De Porcellinis, Alice; Frigaard, Niels-Ulrik; Sakuragi, Yumiko

    2017-07-17

    Cyanobacteria accumulate glycogen as a major intracellular carbon and energy storage during photosynthesis. Recent developments in research have highlighted complex mechanisms of glycogen metabolism, including the diel cycle of biosynthesis and catabolism, redox regulation, and the involvement of non-coding RNA. At the same time, efforts are being made to redirect carbon from glycogen to desirable products in genetically engineered cyanobacteria to enhance product yields. Several methods are used to determine the glycogen contents in cyanobacteria, with variable accuracies and technical complexities. Here, we provide a detailed protocol for the reliable determination of the glycogen content in cyanobacteria that can be performed in a standard life science laboratory. The protocol entails the selective precipitation of glycogen from the cell lysate and the enzymatic depolymerization of glycogen to generate glucose monomers, which are detected by a glucose oxidase-peroxidase (GOD-POD) enzyme coupled assay. The method has been applied to Synechocystis sp. PCC 6803 and Synechococcus sp. PCC 7002, two model cyanobacterial species that are widely used in metabolic engineering. Moreover, the method successfully showed differences in the glycogen contents between the wildtype and mutants defective in regulatory elements or glycogen biosynthetic genes.

  12. Improved Free Fatty Acid Production in Cyanobacteria with Synechococcus sp. PCC 7002 as Host.

    Science.gov (United States)

    Ruffing, Anne M

    2014-01-01

    Microbial free fatty acids (FFAs) have been proposed as a potential feedstock for renewable energy. The ability to directly convert carbon dioxide into FFAs makes cyanobacteria ideal hosts for renewable FFA production. Previous metabolic engineering efforts using the cyanobacterial hosts Synechocystis sp. PCC 6803 and Synechococcus elongatus PCC 7942 have demonstrated this direct conversion of carbon dioxide into FFAs; however, FFA yields in these hosts are limited by the negative impact of FFA production on the host cell physiology. This work investigates the use of Synechococcus sp. PCC 7002 as a cyanobacterial host for FFA production. In comparison to S. elongatus PCC 7942, Synechococcus sp. PCC 7002 strains produced and excreted FFAs at similar concentrations but without the detrimental effects on host physiology. The enhanced tolerance to FFA production with Synechococcus sp. PCC 7002 was found to be temperature-dependent, with physiological effects such as reduced photosynthetic yield and decreased photosynthetic pigments observed at higher temperatures. Additional genetic manipulations were targeted for increased FFA production, including thioesterases and ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO). Overexpression of non-native RuBisCO subunits (rbcLS) from a psbAI promoter resulted in more than a threefold increase in FFA production, with excreted FFA concentrations reaching >130 mg/L. This work illustrates the importance of host strain selection for cyanobacterial biofuel production and demonstrates that the FFA tolerance of Synechococcus sp. PCC 7002 can allow for high yields of excreted FFA.

  13. Efficient purification protocol for bioengineering allophycocyanin trimer with N-terminus Histag

    Directory of Open Access Journals (Sweden)

    Wenjun Li

    2017-03-01

    Full Text Available Allophycocyanin plays a key role for the photon energy transfer from the phycobilisome to reaction center chlorophylls with high efficiency in cyanobacteria. Previously, the high soluble self-assembled bioengineering allophycocyanin trimer with N-terminus polyhistidine from Synechocystis sp. PCC 6803 had been successfully recombined and expressed in Escherichia coli strain. The standard protocol with immobilized metal-ion affinity chromatography with chelating transition metal ion (Ni2+ was used to purify the recombinant protein. Extensive optimization works were performed to obtain the desired protocol for high efficiency, low disassociation, simplicity and fitting for large-scale purification. In this study, a 33 full factorial response surface methodology was employed to optimize the varied factors such as pH of potassium phosphate (X1, NaCl concentration (X2, and imidazole concentration (X3. A maximum trimerization ratio (Y1 of approximate A650 nm/A620 nm at 1.024 was obtained at these optimum parameters. Further examinations, with absorbance spectra, fluorescence spectra and SDS-PAGE, confirmed the presence of bioengineering allophycocyanin trimer with highly trimeric form. All these results demonstrate that optimized protocol is efficient in purification of bioengineering allophycocyanin trimer with Histag.

  14. Expression of acyl-lipid Delta12-desaturase gene in prokaryotic and eukaryotic cells and its effect on cold stress tolerance of potato.

    Science.gov (United States)

    Amiri, Reza Maali; Yur'eva, Natalia O; Shimshilashvili, Khristina R; Goldenkova-Pavlova, Irina V; Pchelkin, Vasiliy P; Kuznitsova, Elmira I; Tsydendambaev, Vladimir D; Trunova, Tamara I; Los, Dmitry A; Jouzani, Gholamreza Salehi; Nosov, Alexander M

    2010-03-01

    We report the expression profile of acyl-lipid Delta12-desaturase (desA) gene from Synechocystis sp. PCC6803 and its effect on cell membrane lipid composition and cold tolerance in prokaryotic (Escherichia coli) and eukaryotic (Solanum tuberosum) cells. For this purpose, a hybrid of desA and reporter gene encoding thermostable lichenase (licBM3) was constructed and used to transform these cells. The expression of this hybrid gene was measured using qualitative (Petri dish test, electrophoregram and zymogram) and quantitative methods (spectrometry and gas liquid chromatography assays). The maximum level of linoleic acid in the bacterial cells containing hybrid gene was 1.9% of total fatty acids. Cold stress tolerance assays using plant damage index and growth parameters showed that cold tolerance was enhanced in primary transgenic lines because of increased unsaturated fatty acid concentration in their lipids. The greatest content of 18:2 and 18:3 fatty acids in primary transgenic plants was observed for lines 2 (73%) and 3 (41%). Finally, our results showed that desaturase could enhance tolerance to cold stress in potato, and desaturase and lichenase retain their functionality in the structure of the hybrid protein where the enzymatic activity of target gene product was higher than in the case of reporter lichenase gene absence in the construction.

  15. A Novel Method for Accurate Operon Predictions in All SequencedProkaryotes

    Energy Technology Data Exchange (ETDEWEB)

    Price, Morgan N.; Huang, Katherine H.; Alm, Eric J.; Arkin, Adam P.

    2004-12-01

    We combine comparative genomic measures and the distance separating adjacent genes to predict operons in 124 completely sequenced prokaryotic genomes. Our method automatically tailors itself to each genome using sequence information alone, and thus can be applied to any prokaryote. For Escherichia coli K12 and Bacillus subtilis, our method is 85 and 83% accurate, respectively, which is similar to the accuracy of methods that use the same features but are trained on experimentally characterized transcripts. In Halobacterium NRC-1 and in Helicobacterpylori, our method correctly infers that genes in operons are separated by shorter distances than they are in E.coli, and its predictions using distance alone are more accurate than distance-only predictions trained on a database of E.coli transcripts. We use microarray data from sixphylogenetically diverse prokaryotes to show that combining intergenic distance with comparative genomic measures further improves accuracy and that our method is broadly effective. Finally, we survey operon structure across 124 genomes, and find several surprises: H.pylori has many operons, contrary to previous reports; Bacillus anthracis has an unusual number of pseudogenes within conserved operons; and Synechocystis PCC6803 has many operons even though it has unusually wide spacings between conserved adjacent genes.

  16. A Deg-protease family protein in marine Synechococcus is involved in outer membrane protein organization

    Directory of Open Access Journals (Sweden)

    Rhona Kayra Stuart

    2014-06-01

    Full Text Available Deg-family proteases are a periplasm-associated group of proteins that are known to be involved in envelope stress responses and are found in most microorganisms. Orthologous genes SYNW2176 (in strain WH8102 and sync_2523 (strain CC9311 are predicted members of the Deg-protease family and are among the few genes induced by copper stress in both open ocean and coastal marine Synechococcus strains. In contrast to the lack of a phenotype in a similar knockout in Synechocystis PCC6803, a SYNW2176 knockout mutant in strain WH8102 was much more resistant to copper than the wild-type. The mutant also exhibited a significantly altered outer membrane protein composition which may contribute to copper resistance, longer lag phase after transfer, low-level consistent alkaline phosphatase activity, and an inability to induce high alkaline phosphatase activity in response to phosphate stress. This phenotype suggests a protein-quality-control role for SYNW2176, the absence of which leads to a constitutively activated stress response. Deg-protease family proteins in this ecologically important cyanobacterial group thus help to determine outer membrane responses to both nutrients and toxins.

  17. Conserved gene clusters in bacterial genomes provide further support for the primacy of RNA

    Science.gov (United States)

    Siefert, J. L.; Martin, K. A.; Abdi, F.; Widger, W. R.; Fox, G. E.

    1997-01-01

    Five complete bacterial genome sequences have been released to the scientific community. These include four (eu)Bacteria, Haemophilus influenzae, Mycoplasma genitalium, M. pneumoniae, and Synechocystis PCC 6803, as well as one Archaeon, Methanococcus jannaschii. Features of organization shared by these genomes are likely to have arisen very early in the history of the bacteria and thus can be expected to provide further insight into the nature of early ancestors. Results of a genome comparison of these five organisms confirm earlier observations that gene order is remarkably unpreserved. There are, nevertheless, at least 16 clusters of two or more genes whose order remains the same among the four (eu)Bacteria and these are presumed to reflect conserved elements of coordinated gene expression that require gene proximity. Eight of these gene orders are essentially conserved in the Archaea as well. Many of these clusters are known to be regulated by RNA-level mechanisms in Escherichia coli, which supports the earlier suggestion that this type of regulation of gene expression may have arisen very early. We conclude that although the last common ancestor may have had a DNA genome, it likely was preceded by progenotes with an RNA genome.

  18. Specific and efficient targeting of cyanobacterial bicarbonate transporters to the inner envelope membrane of chloroplasts in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Susumu eUehara

    2016-02-01

    Full Text Available Installation of cyanobacterial bicarbonate transporters to the inner envelope membrane (IEM of chloroplasts in C3 plants has been thought to improve photosynthetic performance. However, the method to deliver cyanobacterial bicarbonate transporters to the chloroplast IEM remains to be established. In this study, we provide evidence that the cyanobacterial bicarbonate transporters, BicA and SbtA, can be specifically installed into the chloroplast IEM using the chloroplast IEM targeting signal in conjunction with the transit peptide. We fused the transit peptide and the mature portion of Cor413im1, whose targeting mechanism to the IEM has been characterized in detail, to either BicA or SbtA isolated from Synechocystis sp. PCC6803. Among the seven chimeric constructs tested, we confirmed that four chimeric bicarbonate transporters, designated as BicAI, BicAII, SbtAII, and SbtAIII, were expressed in Arabidopsis. Furthermore, these chimeric transporters were specifically targeted to the chloroplast IEM. They were also resistant to alkaline extraction but can be solubilized by Triton X-100, indicating that they are integral membrane proteins in the chloroplast IEM. One of the transporters, BicA, could reside in the chloroplast IEM even after removal of the IEM targeting signal. Taken together, our results indicate that the addition of IEM targeting signal, as well as the transit peptide, to bicarbonate transporters allows us to efficiently target nuclear-encoded chimeric bicarbonate transporters to the chloroplast IEM.

  19. The Structure of a Cyanobacterial Bicarbonate Transport Protein, CmpA

    Energy Technology Data Exchange (ETDEWEB)

    Koropatkin, Nicole M.; Koppenaal, David W.; Pakrasi, Himadri B.; Smith, Thomas J.

    2007-01-26

    Cyanobacteria, blue-green algae, are the most abundant autotrophs in aquatic environments and form the base of the food chain by fixing carbon and nitrogen into cellular biomass. To compensate for the low selectivity of Rubisco for CO₂ over O₂, Cyanobacteria have developed highly efficient CO₂concentrating machinery of which the ABC transport system CmpABCD from Synechocystis PCC 6803 is one component. Here we describe the structure of the bicarbonate binding protein, CmpA, in the absence and presence of bicarbonate and carbonic acid. CmpA is highly homologous to the nitrate transport protein, NrtA. CmpA binds carbonic acid at the entrance to the ligand-binding pocket whereas bicarbonate binds in nearly an identical location compared to nitrate binding to NrtA. Unexpectedly, bicarbonate binding is accompanied by a metal ion, identified as Ca²⁺ via inductively coupled plasma optical emission spectrometry. The binding of bicarbonate and metal is highly cooperative and suggests that CmpA co-transports bicarbonate and calcium.

  20. Selection of microalgae and cyanobacteria strains for bicarbonate-based integrated carbon capture and algae production system.

    Science.gov (United States)

    Chi, Zhanyou; Elloy, Farah; Xie, Yuxiao; Hu, Yucai; Chen, Shulin

    2014-01-01

    Using microalgae to capture CO2 from flue gas is an ideal way to reduce CO2 emission, but this is challenged by the high cost of carbon capture and transportation. To address this problem, a bicarbonate-based integrated carbon capture and algae production system (BICCAPS) has been proposed, in which bicarbonate is used for algae culture, and the regenerated carbonate from this process can be used to capture more CO2. High-concentration bicarbonate is obligate for the BICCAPS. Thus, different strains of microalgae and cyanobacteria were tested in this study for their capability to grow in high-concentration NaHCO3. The highest NaHCO3 concentrations they are tolerant to were determined as 0.30 M for Synechocystis sp. PCC6803, 0.60 M for Cyanothece sp., 0.10 M for Chlorella sorokiniana, 0.60 M for Dunaliella salina, and 0.30 M for Dunaliella viridis and Dunaliella primolecta. In further study, biomass production from culture of D. primolecta in an Erlenmeyer flask with either 0.30 M NaHCO3 or 2 % CO2 bubbling was compared, and no significant difference was detected. This indicates BICCAPS can reach the same biomass productivity as regular CO2 bubbling culture, and it is promising for future application.

  1. Cyanobacterial defense mechanisms against foreign DNA transfer and their impact on genetic engineering

    Directory of Open Access Journals (Sweden)

    Karina Stucken

    2013-01-01

    Full Text Available Cyanobacteria display a large diversity of cellular forms ranging from unicellular to complex multicellular filaments or aggregates. Species in the group present a wide range of metabolic characteristics including the fixation of atmospheric nitrogen, resistance to extreme environments, production of hydrogen, secondary metabolites and exopolysaccharides. These characteristics led to the growing interest in cyanobacteria across the fields of ecology, evolution, cell biology and biotechnology. The number of available cyanobacterial genome sequences has increased considerably in recent years, with more than 140 fully sequenced genomes to date. Genetic engineering of cyanobacteria is widely applied to the model unicellular strains Synechocystis sp. PCC 6803 and Synechococcus elongatus PCC 7942. However the establishment of transformation protocols in many other cyanobacterial strains is challenging. One obstacle to the development of these novel model organisms is that many species have doubling times of 48 h or more, much longer than the bacterial models E. coli or B. subtilis. Furthermore, cyanobacterial defense mechanisms against foreign DNA pose a physical and biochemical barrier to DNA insertion in most strains. Here we review the various barriers to DNA uptake in the context of lateral gene transfer among microbes and the various mechanisms for DNA acquisition within the prokaryotic domain. Understanding the cyanobacterial defense mechanisms is expected to assist in the development and establishment of novel transformation protocols that are specifically suitable for this group.

  2. Effect of partial or complete elimination of light-harvesting complexes on the surface electric properties and the functions of cyanobacterial photosynthetic membranes.

    Science.gov (United States)

    Dobrikova, Anelia G; Domonkos, Ildikó; Sözer, Özge; Laczkó-Dobos, Hajnalka; Kis, Mihály; Párducz, Árpád; Gombos, Zoltán; Apostolova, Emilia L

    2013-02-01

    Influence of the modification of the cyanobacterial light-harvesting complex [i.e. phycobilisomes (PBS)] on the surface electric properties and the functions of photosynthetic membranes was investigated. We used four PBS mutant strains of Synechocystis sp. PCC6803 as follows: PAL (PBS-less), CK (phycocyanin-less), BE (PSII-PBS-less) and PSI-less/apcE(-) (PSI-less with detached PBS). Modifications of the PBS content lead to changes in the cell morphology and surface electric properties of the thylakoid membranes as well as in their functions, such as photosynthetic oxygen-evolving activity, P700 kinetics and energy transfer between the pigment-protein complexes. Data reveal that the complete elimination of PBS in the PAL mutant causes a slight decrease in the electric dipole moments of the thylakoid membranes, whereas significant perturbations of the surface charges were registered in the membranes without assembled PBS-PSII macrocomplex (BE mutant) or PSI complex (PSI-less mutant). These observations correlate with the detected alterations in the membrane structural organization. Using a polarographic oxygen rate electrode, we showed that the ratio of the fast to the slow oxygen-evolving PSII centers depends on the partial or complete elimination of light-harvesting complexes, as the slow operating PSII centers dominate in the PBS-less mutant and in the mutant with detached PBS. Copyright © Physiologia Plantarum 2012.

  3. Physiological tolerance and stoichiometric potential of cyanobacteria for hydrocarbon fuel production.

    Science.gov (United States)

    Kämäräinen, Jari; Knoop, Henning; Stanford, Natalie J; Guerrero, Fernando; Akhtar, M Kalim; Aro, Eva-Mari; Steuer, Ralf; Jones, Patrik R

    2012-11-30

    Cyanobacteria are capable of directly converting sunlight, carbon dioxide and water into hydrocarbon fuel or precursors thereof. Many biological and non-biological factors will influence the ability of such a production system to become economically sustainable. We evaluated two factors in engineerable cyanobacteria which could potentially limit economic sustainability: (i) tolerance of the host to the intended end-product, and (ii) stoichiometric potential for production. Alcohols, when externally added, inhibited growth the most, followed by aldehydes and acids, whilst alkanes were the least inhibitory. The growth inhibition became progressively greater with increasing chain-length for alcohols, whilst the intermediate C6 alkane caused more inhibition than both C3 and C11 alkane. Synechocystis sp. PCC 6803 was more tolerant to some of the tested chemicals than Synechococcus elongatus PCC 7942, particularly ethanol and undecane. Stoichiometric evaluation of the potential yields suggested that there is no difference in the potential productivity of harvestable energy between any of the studied fuels, with the exception of ethylene, for which maximal stoichiometric yield is considerably lower. In summary, it was concluded that alkanes would constitute the best choice metabolic end-product for fuel production using cyanobacteria if high-yielding strains can be developed. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. A micro-sized bio-solar cell for self-sustaining power generation.

    Science.gov (United States)

    Lee, Hankeun; Choi, Seokheun

    2015-01-21

    Self-sustainable energy sources are essential for a wide array of wireless applications deployed in remote field locations. Due to their self-assembling and self-repairing properties, "biological solar (bio-solar) cells" are recently gaining attention for those applications. The bio-solar cell can continuously generate electricity from microbial photosynthetic and respiratory activities under day-night cycles. Despite the vast potential and promise of bio-solar cells, they, however, have not yet successfully been translated into commercial applications, as they possess persistent performance limitations and scale-up bottlenecks. Here, we report an entirely self-sustainable and scalable microliter-sized bio-solar cell with significant power enhancement by maximizing solar energy capture, bacterial attachment, and air bubble volume in well-controlled microchambers. The bio-solar cell has a ~300 μL single chamber defined by laser-machined poly(methyl methacrylate) (PMMA) substrates and it uses an air cathode to allow freely available oxygen to act as an electron acceptor. We generated a maximum power density of 0.9 mW m(-2) through photosynthetic reactions of cyanobacteria, Synechocystis sp. PCC 6803, which is the highest power density among all micro-sized bio-solar cells.

  5. A simple viability analysis for unicellular cyanobacteria using a new autofluorescence assay, automated microscopy, and ImageJ

    Directory of Open Access Journals (Sweden)

    Schulze Katja

    2011-11-01

    Full Text Available Abstract Background Currently established methods to identify viable and non-viable cells of cyanobacteria are either time-consuming (eg. plating or preparation-intensive (eg. fluorescent staining. In this paper we present a new and fast viability assay for unicellular cyanobacteria, which uses red chlorophyll fluorescence and an unspecific green autofluorescence for the differentiation of viable and non-viable cells without the need of sample preparation. Results The viability assay for unicellular cyanobacteria using red and green autofluorescence was established and validated for the model organism Synechocystis sp. PCC 6803. Both autofluorescence signals could be observed simultaneously allowing a direct classification of viable and non-viable cells. The results were confirmed by plating/colony count, absorption spectra and chlorophyll measurements. The use of an automated fluorescence microscope and a novel ImageJ based image analysis plugin allow a semi-automated analysis. Conclusions The new method simplifies the process of viability analysis and allows a quick and accurate analysis. Furthermore results indicate that a combination of the new assay with absorption spectra or chlorophyll concentration measurements allows the estimation of the vitality of cells.

  6. Insights into the Cyanobacterial Deg/HtrA Proteases

    Directory of Open Access Journals (Sweden)

    Otilia eCheregi

    2016-05-01

    Full Text Available Proteins are the main machinery for all living processes in a cell; they provide structural elements, regulate biochemical reactions as enzymes, and are the interface to the outside as receptors and transporters. Like any other machinery proteins have to be assembled correctly and need maintenance after damage, e.g. caused by changes in environmental conditions, genetic mutations, and limitations in the availability of cofactors. Proteases and chaperones help in repair, assembly, and folding of damaged and misfolded protein complexes cost-effective, with low energy investment compared with neo-synthesis. Despite their importance for viability, the specific biological role of most proteases in vivo is largely unknown. Deg/HtrA proteases, a family of serine-type ATP-independent proteases, have been shown in higher plants to be involved in the degradation of the Photosystem II reaction center protein D1. The objective of this review is to highlight the structure and function of their cyanobacterial orthologues. Homology modeling was used to find specific features of the Deg/HtrA proteases of Synechocystis sp. PCC 6803. Based on the available data concerning their location and their physiological substrates we conclude that these Deg proteases not only have important housekeeping and chaperone functions within the cell, but also are needed for remodeling the cell exterior.

  7. Cyanobacterial Sfp-type phosphopantetheinyl transferases functionalize carrier proteins of diverse biosynthetic pathways.

    Science.gov (United States)

    Yang, Guang; Zhang, Yi; Lee, Nicholas K; Cozad, Monica A; Kearney, Sara E; Luesch, Hendrik; Ding, Yousong

    2017-09-19

    Cyanobacteria produce structurally and functionally diverse polyketides, nonribosomal peptides and their hybrids. Sfp-type phosphopantetheinyl transferases (PPTases) are essential to the production of these compounds via functionalizing carrier proteins (CPs) of biosynthetic megaenzymes. However, cyanobacterial Sfp-type PPTases remain poorly characterized, posing a significant barrier to the exploitation of cyanobacteria for biotechnological and biomedical applications. Herein, we describe the detailed characterization of multiple cyanobacterial Sfp-type PPTases that were rationally selected. Biochemical characterization of these enzymes along with the prototypic enzyme Sfp from Bacillus subtilis demonstrated their varying specificities toward 11 recombinant CPs of different types of biosynthetic pathways from cyanobacterial and Streptomyces strains. Kinetic analysis further indicated that PPTases possess the higher binding affinity and catalytic efficiency toward their cognate CPs in comparison with noncognate substrates. Moreover, when chromosomally replacing the native PPTase gene of Synechocystis sp. PCC6803, two selected cyanobacterial PPTases and Sfp supported the growth of resulted mutants. Cell lysates of the cyanobacterial mutants further functionalized recombinant CP substrates. Collectively, these studies reveal the versatile catalysis of selected cyanobacterial PPTases and provide new tools to synthesize cyanobacterial natural products using in vitro and in vivo synthetic biology approaches.

  8. Enhancement of human adaptive immune responses by administration of a high-molecular-weight polysaccharide extract from the cyanobacterium Arthrospira platensis

    DEFF Research Database (Denmark)

    Løbner, Morten; Walsted, Anette; Larsen, Rune

    2008-01-01

    The effect of consumption of Immulina, a high-molecular-weight polysaccharide extract from the cyanobacterium Arthrospira platensis, on adaptive immune responses was investigated by evaluation of changes in leukocyte responsiveness to two foreign recall antigens, Candida albicans (CA) and tetanus......beta, and IL-6 responses, indicating that it acts by inducing a pro-inflammatory state. Taken together, the data suggest that Immulina causes an age-dependent, temporary enhancement of adaptive immune responses....

  9. Draft Genome Sequence of Cyanobacterium sp. Strain HL-69, Isolated from a Benthic Microbial Mat from a Magnesium Sulfate-Dominated Hypersaline Lake

    Energy Technology Data Exchange (ETDEWEB)

    Mobberley, J. M.; Romine, M. F.; Cole, J. K.; Maezato, Y.; Lindemann, S. R.; Nelson, W. C.

    2018-02-08

    ABSTRACT

    The complete genome sequence ofCyanobacteriumsp. strain HL-69 consists of 3,155,247 bp and contains 2,897 predicted genes comprising a chromosome and two plasmids. The genome is consistent with a halophilic nondiazotrophic phototrophic lifestyle, and this organism is able to synthesize most B vitamins and produces several secondary metabolites.

  10. Determination of carbon-to-nitrogen ratio in the filamentous and heterocystous cyanobacterium Anabaena sp. PCC 7120 with single-cell soft X-ray imaging

    Science.gov (United States)

    Teramoto, T.; Yoshimura, M.; Azai, C.; Terauchi, K.; Ohta, T.

    2017-06-01

    Vegetative cells and heterocysts in the filamentous cyanobacterium Anabaena sp. PCC 7120 were observed by soft X-ray microscopy. Carbon-to-nitrogen (C/N) ratio of each cell was estimated by the difference of the absorbance of the images below and above the nitrogen K-edge absorption. It was revealed that the C/N ratios in vegetative cells and heterocysts are 4.54 and 2.46, respectively.

  11. An assessment of the usefulness of the cyanobacterium Synechococcus subsalsus as a source of biomass for biofuel production

    Directory of Open Access Journals (Sweden)

    Bruno R.S. Setta

    2014-05-01

    Full Text Available Nowadays algal biofuels are considered one of the most promising solutions of global energy crisis and climate change for the years to come. By manipulation of the culture conditions, many algal species can be induced to accumulate high concentrations of particular biomolecules and can be directed to the desired output for each fuel. In this context, the present study involved the assessment of the effects of CO2 availability and nitrogen starvation on growth and chemical composition of the cyanobacterium Synechococcus subsalsus, testing a fast-growing native strain. The control experiments were performed with Conway culture medium in 12-day batch cultures, in 6-liter flasks and 12 h photoperiod, with addition of 2 L min-1 filtered air to each flask. Other two experimental conditions were also tested: (i the placement into the cultures of additional dissolved nutrients except nitrogen, one week after the start of growth (N-, and (ii the input of pure CO2 into the flasks from the 5th day of growth (C+. In all cultures, daily cell counts were done throughout the cultivation, as well as measurements of pH and cell biovolumes. Maximum cell yield were found in N-experiments, while cell yields of C+ and control were similar. Dissolved nitrogen was exhausted before the end of the experiments, but dissolved phosphorus was not totally consumed. Protein and chlorophyll-a concentrations decreased from the exponential to the stationary growth phase of all experiments, except for protein in the control. In all experiments, carbohydrate, lipid and total carotenoid increased from the exponential to the stationary growth phase, as an effect of nitrogen limitation. Increments in carbohydrate concentrations were remarkable, achieving more than 42% of the dry weight (dw, but concentrations of lipid were always lower than 13% dw. The addition of pure CO2 did not cause a significant increase in biomass of S. subsalsus nor generated more lipid and carbohydrate than

  12. Probit Analysis of Carbamate-Pesticide-Toxicity at Soil-Water Interface to N2-Fixing Cyanobacterium Cylindrospermum sp

    Directory of Open Access Journals (Sweden)

    Rabindra N. Padhy

    2015-03-01

    Full Text Available Toxicity-data of two carbamate insecticides, carbaryl and carbofuran, and three fungicides, ziram, zineb and mancozeb with rice-field N2-fixing cyanobacterium Cylindrospermum sp., obtained by in vitro growth and at soil-water interface, were analyzed by the probit method. Growth enhancing concentration, no-observed effective concentration, minimum inhibitory concentration, the highest permissive concentration and lethal concentration100 (LC100 were determined experimentally. The LC50 values of carbaryl, carbofuran, ziram, zineb and mancozeb in N2-fixing liquid medium were 56.2, 588.8, 0.07, 4.2 and 3.4 μg/mL, respectively, whereas the corresponding LC100 values were 100.0, 1500.0, 0.17, 25.0 and 9.0 μg/mL, respectively. The LC50 values of these pesticides in succession in N2-fixing agar medium were 44.7, 239.9, 0.07, 1.8 and 2.3 μg/mL, respectively, whereas the corresponding LC100 values were 100.0, 600.0, 0.17, 10.0 and 7.0 μg/mL, respectively. Similar results with nitrate supplemented liquid and agar media indicated that nitrate supplementation had toxicity reducing effect. The LC50 and LC100 values of toxicity in the N2-fixing liquid medium at soil-water interface were 91.2 and 200.0 μg/mL for carbaryl, 2 317 and 6 000 μg/mL for carbofuran, 0.15 and 0.50 μg/mL for ziram, 16.4 and 50.0 μg/mL for zineb, and 7.2 and 25.0 μg/mL for mancozeb, respectively. Each LC100 value at soil-water interface with a pesticide was significantly higher than its corresponding LC100 value at liquid/agar media. It can be concluded that, under the N2-fixing conditions, the cyanobacterium tolerated higher levels of each pesticide at soil-water interface.

  13. Transcriptional analysis of the jamaicamide gene cluster from the marine cyanobacterium Lyngbya majuscula and identification of possible regulatory proteins

    Directory of Open Access Journals (Sweden)

    Dorrestein Pieter C

    2009-12-01

    Full Text Available Abstract Background The marine cyanobacterium Lyngbya majuscula is a prolific producer of bioactive secondary metabolites. Although biosynthetic gene clusters encoding several of these compounds have been identified, little is known about how these clusters of genes are transcribed or regulated, and techniques targeting genetic manipulation in Lyngbya strains have not yet been developed. We conducted transcriptional analyses of the jamaicamide gene cluster from a Jamaican strain of Lyngbya majuscula, and isolated proteins that could be involved in jamaicamide regulation. Results An unusually long untranslated leader region of approximately 840 bp is located between the jamaicamide transcription start site (TSS and gene cluster start codon. All of the intergenic regions between the pathway ORFs were transcribed into RNA in RT-PCR experiments; however, a promoter prediction program indicated the possible presence of promoters in multiple intergenic regions. Because the functionality of these promoters could not be verified in vivo, we used a reporter gene assay in E. coli to show that several of these intergenic regions, as well as the primary promoter preceding the TSS, are capable of driving β-galactosidase production. A protein pulldown assay was also used to isolate proteins that may regulate the jamaicamide pathway. Pulldown experiments using the intergenic region upstream of jamA as a DNA probe isolated two proteins that were identified by LC-MS/MS. By BLAST analysis, one of these had close sequence identity to a regulatory protein in another cyanobacterial species. Protein comparisons suggest a possible correlation between secondary metabolism regulation and light dependent complementary chromatic adaptation. Electromobility shift assays were used to evaluate binding of the recombinant proteins to the jamaicamide promoter region. Conclusion Insights into natural product regulation in cyanobacteria are of significant value to drug discovery

  14. Engineering a cyanobacterium as the catalyst for the photosynthetic conversion of CO2 to 1,2-propanediol

    Directory of Open Access Journals (Sweden)

    Li Han

    2013-01-01

    Full Text Available Abstract Background The modern society primarily relies on petroleum and natural gas for the production of fuels and chemicals. One of the major commodity chemicals 1,2-propanediol (1,2-PDO, which has an annual production of more than 0.5 million tons in the United States, is currently produced by chemical processes from petroleum derived propylene oxide, which is energy intensive and not sustainable. In this study, we sought to achieve phot