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Sample records for anabaena sp pcc

  1. Lipopolysaccharide dependence of cyanophage sensitivity and aerobic nitrogen fixation in Anabaena sp. strain PCC 7120.

    OpenAIRE

    Xu, X.; Khudyakov, I; Wolk, C P

    1997-01-01

    Fox- mutants of Anabaena sp. strain PCC 7120 are unable to fix dinitrogen in the presence of oxygen. A fragment of the DNA of Anabaena sp. was cloned by complementation of a spontaneous Fox-, cyanophage-resistant mutant, R56, and characterized. Random insertion of transposon Tn5 delimited the complementing DNA to a 0.6-kb portion of the cloned fragment. Sequencing of this region and flanking DNA showed one complete open reading frame (ORF) similar to the gene rfbP (undecaprenyl-phosphate gala...

  2. Protein tyrosine phosphorylation in the cyanobacterium Anabaena sp. strain PCC 7120.

    OpenAIRE

    McCartney, B; Howell, L.D.; Kennelly, P J; Potts, M.

    1997-01-01

    Components of a protein tyrosine phosphorylation/dephosphorylation network were identified in the cyanobacterium Anabaena sp. strain PCC 7120. Three phosphotyrosine (P-Tyr) proteins of 27, 36, and 52 kDa were identified through their conspicuous immunoreactions with RC20H monoclonal antibodies specific for P-Tyr. These immunoreactions were outcompeted completely by free P-Tyr (5 mM) but not by phosphoserine or phosphothreonine. The P-Tyr content of the three major P-Tyr proteins and several m...

  3. patS Minigenes Inhibit Heterocyst Development of Anabaena sp. Strain PCC 7120

    OpenAIRE

    Wu, Xiaoqiang; Liu, Duan; Lee, Martin H.; Golden, James W.

    2004-01-01

    The patS gene encodes a small peptide that is required for normal heterocyst pattern formation in the cyanobacterium Anabaena sp. strain PCC 7120. PatS is proposed to control the heterocyst pattern by lateral inhibition. patS minigenes were constructed and expressed by different developmentally regulated promoters to gain further insight into PatS signaling. patS minigenes patS4 to patS8 encode PatS C-terminal 4 (GSGR) to 8 (CDERGSGR) oligopeptides. When expressed by PpetE, PpatS, or PrbcL pr...

  4. The Anabaena sp. PCC 7120 Exoproteome: Taking a Peek outside the Box

    Directory of Open Access Journals (Sweden)

    Paulo Oliveira

    2015-01-01

    Full Text Available The interest in examining the subset of proteins present in the extracellular milieu, the exoproteome, has been growing due to novel insights highlighting their role on extracellular matrix organization and biofilm formation, but also on homeostasis and development. The cyanobacterial exoproteome is poorly studied, and the role of cyanobacterial exoproteins on cell wall biogenesis, morphology and even physiology is largely unknown. Here, we present a comprehensive examination of the Anabaena sp. PCC 7120 exoproteome under various growth conditions. Altogether, 139 proteins belonging to 16 different functional categories have been identified. A large fraction (48% of the identified proteins is classified as “hypothetical”, falls into the “other categories” set or presents no similarity to other proteins. The evidence presented here shows that Anabaena sp. PCC 7120 is capable of outer membrane vesicle formation and that these vesicles are likely to contribute to the exoproteome profile. Furthermore, the activity of selected exoproteins associated with oxidative stress has been assessed, suggesting their involvement in redox homeostasis mechanisms in the extracellular space. Finally, we discuss our results in light of other cyanobacterial exoproteome studies and focus on the potential of exploring cyanobacteria as cell factories to produce and secrete selected proteins.

  5. Lipopolysaccharide dependence of cyanophage sensitivity and aerobic nitrogen fixation in Anabaena sp. strain PCC 7120.

    Science.gov (United States)

    Xu, X; Khudyakov, I; Wolk, C P

    1997-05-01

    Fox- mutants of Anabaena sp. strain PCC 7120 are unable to fix dinitrogen in the presence of oxygen. A fragment of the DNA of Anabaena sp. was cloned by complementation of a spontaneous Fox-, cyanophage-resistant mutant, R56, and characterized. Random insertion of transposon Tn5 delimited the complementing DNA to a 0.6-kb portion of the cloned fragment. Sequencing of this region and flanking DNA showed one complete open reading frame (ORF) similar to the gene rfbP (undecaprenyl-phosphate galactosephosphotransferase) and two partial ORFs similar to genes rfbD (GDP-D-mannose dehydratase) and rfbZ (first mannosyl transferase), all of which are active in the synthesis of the O antigen unit of the lipopolysaccharide (LPS) component of the outer membrane of gram-negative bacteria. In a transposon (Tn5-1087b)-induced, Fox-, cyanophage-resistant mutant, B14, the transposon was found within the same rfbP-like ORF. The three ORFs were insertionally inactivated with the omega cassette (P. Prentki and H. M. Krisch, Gene 29:303-313, 1984) or with Tn5::omega. Only the insertions in the rfbZ- and rfbP-like ORFs led to resistance to cyanophages A-1(L) and A-4(L) and to a Fox- phenotype. Electrophoretic analysis showed that interruption of the rfbZ- and rfbP-like ORFs resulted in a change in or loss of the characteristic pattern of the lengths of the LPS, whereas interruption of the rfbD-like ORF merely changed the distribution of the lengths of the LPS to one with a greater prevalence of low molecular weights. According to electron microscopy, interruption of the rfbP-like ORF may have led to aberrant deposition of the layers of the heterocyst envelope, resulting in increased leakage of oxygen into the heterocyst. The results suggest that modified LPS may prevent cyanophage infection of Anabaena sp. vegetative cells and the formation of a functional heterocyst envelope. PMID:9139904

  6. Isolation and complementation of mutants of Anabaena sp. strain PCC 7120 unable to grow aerobically on dinitrogen

    International Nuclear Information System (INIS)

    Mutants of Anabaena sp. strain PCC 7120 unable to grow aerobically on dinitrogen were isolated by mutagenesis with UV irradiation, followed by a period of incubation in yellow light and then by penicillin enrichment. A cosmid vector, pRL25C, containing replicons functional in Escherichia coli and in Anabaena species was constructed. DNA from wild-type Anabaena sp. strain PCC 7120 was partially digested with Sau3AI, and size-fractionated fragments about 40 kilobases (kb) in length were ligated into the phosphatase-treated unique BamHI site of pRL25C. A library of 1054 cosmid clones was generated in E. coli DH1 bearing helper plasmid pDS4101. A derivative of conjugative plasmid RP-4 was transferred to this library by conjugation, and the library was replicated to lawns of mutant Anabaena strains with defects in the polysaccharide layer of the envelopes of the heterocysts. Mutant EF116 was complemented by five cosmids, three of which were subjected to detailed restriction mapping; a 2.8-kb fragment of DNA derived from one of the cosmids was found to complement EF116. Mutant EF113 was complemented by a single cosmid, which was also restriction mapped, and was shown to be complemented by a 4.8-kb fragment of DNA derived from this cosmid

  7. Three fur homologues from Anabaena sp. PCC7120: exploring reciprocal protein-promoter recognition.

    Science.gov (United States)

    Hernández, José A; López-Gomollón, Sara; Bes, M Teresa; Fillat, María F; Peleato, M Luisa

    2004-07-15

    DNA sequence analysis of the Anabaena sp. PCC7120 genome confirmed the presence of three open reading frames (all1691, all2473 and alr0957) containing the histidine-rich region characteristic of the Fur family. The genes coding for the three Fur proteins were cloned and overexpressed in Escherichia coli. The overexpression products, called FurA, FurB and FurC are only distantly related. The ability of the three recombinant proteins to bind iron-boxes identified in the three fur promoter regions was tested by electrophoretical mobility shift assays. FurA binds the three fur promoters with increased affinity in presence of metal. FurB also binds the three fur promoters, and its affinity is increased with DTT. FurC does not bind to furA or furB promoter regions or to its own promoter. However, FurC affects the ability of FurB and FurA to bind their target promoters. PMID:15251208

  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. PMID:26626354

  9. Nuevas funciones de las proteínas Fur en cianobacterias: Contribución a la definición del regulón FurA en Anabaena sp. PCC 7120

    OpenAIRE

    González Rodríguez, Andrés; Fillat Castejón, María Francisca

    2013-01-01

    En el presente trabajo de tesis nos propusimos avanzar en el conocimiento de la funciones de las proteínas Fur en cianobacterias mediante el estudio del regulón FurA de la cianobacteria filamentosa formadora de heterocistos Anabaena sp. PCC 7120. Como herramienta de trabajo para el estudio del regulón construimos una estirpe de sobreexpresión de FurA en Anabaena sp. PCC 7120, empleando un vector lanzadera con orígenes de replicación en E. coli y Anabaena sp. que logró incrementar hasta ~32 ve...

  10. The FurA regulon in Anabaena sp. PCC 7120: in silico prediction and experimental validation of novel target genes

    Science.gov (United States)

    González, Andrés; Angarica, Vladimir Espinosa; Sancho, Javier; Fillat, María F.

    2014-01-01

    In the filamentous cyanobacterium Anabaena sp. PCC 7120, the ferric uptake regulator FurA functions as a global transcriptional regulator. Despite several analyses have focused on elucidating the FurA-regulatory network, the number of target genes described for this essential transcription factor is limited to a handful of examples. In this article, we combine an in silico genome-wide predictive approach with experimental determinations to better define the FurA regulon. Predicted FurA-binding sites were identified upstream of 215 genes belonging to diverse functional categories including iron homeostasis, photosynthesis and respiration, heterocyst differentiation, oxidative stress defence and light-dependent signal transduction mechanisms, among others. The probabilistic model proved to be effective at discerning FurA boxes from non-cognate sequences, while subsequent electrophoretic mobility shift assay experiments confirmed the in vitro specific binding of FurA to at least 20 selected predicted targets. Gene-expression analyses further supported the dual role of FurA as transcriptional modulator that can act both as repressor and as activator. In either role, the in vitro affinity of the protein to its target sequences is strongly dependent on metal co-regulator and reducing conditions, suggesting that FurA couples in vivo iron homeostasis and the response to oxidative stress to major physiological processes in cyanobacteria. PMID:24503250

  11. AhpC (alkyl hydroperoxide reductase) from Anabaena sp. PCC 7120 protects Escherichia coli from multiple abiotic stresses

    International Nuclear Information System (INIS)

    Alkyl hydroperoxide reductase (AhpC) is known to detoxify peroxides and reactive sulfur species (RSS). However, the relationship between its expression and combating of abiotic stresses is still not clear. To investigate this relationship, the genes encoding the alkyl hydroperoxide reductase (ahpC) from Anabaena sp. PCC 7120 were introduced into E. coli using pGEX-5X-2 vector and their possible functions against heat, salt, carbofuron, cadmium, copper and UV-B were analyzed. The transformed E. coli cells registered significantly increase in growth than the control cells under temperature (47 oC), NaCl (6% w/v), carbofuron (0.025 mg ml-1), CdCl2 (4 mM), CuCl2 (1 mM), and UV-B (10 min) exposure. Enhanced expression of ahpC gene as measured by semi-quantitative RT-PCR under aforementioned stresses at different time points demonstrated its role in offering tolerance against multiple abiotic stresses.

  12. Effect of Iron Deficiency on Heterocyst Differentiation and Physiology of the Filamentous Cyanobacterium Anabaena sp. PCC 7120

    Institute of Scientific and Technical Information of China (English)

    XuWen-liang; LiuYong-ding; ZhangCheng-cai

    2003-01-01

    The effect of iron deficiency on heterocyst differentiation and some physiological properties of the filamentous cyanobacterium Anabaena sp. PCC 7120 was investigated. Under moderate iron limitation conditions, achieved by addition of iron chelator 2,2′-Dipyridyl (<80 μmol/L) led to delayed heterocyst differentiation,no heterocyst differentiation was observed under severe iron limitation conditions,when the concentration of 2,2′-Dipyridyl in the medium was more than 100 μmol/L.It seemed that there are certain iron-regulated genes or operons whose function is to control heterocyst development. In addition, iron deficiency impaired the growth.Low-iron cells had a decrease in the quantities of pigment content (chlorophyll and phycocyanin content), the whole cell in vivo absorbance spectra confirmed the decrease, the protein electrophoretic profiles revealed that iron-deficient cells had less protein bands, with the increase of 2,2'-Dipyridyl , the protein bands was more and more less. And differently, iron deficiency also caused an increase of ROS (Reactive Oxygen Species)and SOD activity, it suggests that iron deficiency led to oxidative stress, which uenerallv occured under hiuh-iron conditions.

  13. Effect of Iron Deficiency on Heterocyst Differentiation and Physiology of the Filamentous Cyanobacterium Anabaena sp. PCC 7120

    Institute of Scientific and Technical Information of China (English)

    Zhang Cheng-cai

    2003-01-01

    The effect of iron deficiency on heterocyst differentiation and some physiological properties of the filamentous cyanobacterium Anabaena sp. PCC 7120was investigated. Under moderate iron limitation conditions, achieved by addition of iron chelator 2,2′-Dipyridyl (<80 μmol/L) led to delayed heterocyst differentiation,no heterocyst differentiation was observed under severe iron limitation conditions,when the concentration of 2,2′-Dipyridyl in the medium was more than 100 μmol/L.It seemed that there are certain iron-regulated genes or operons whose function is to control heterocyst development. In addition, iron deficiency impaired the growth.Low-iron cells had a decrease in the quantities of pigment content (chlorophyll and phycocyanin content), the whole cell in vivo absorbance spectra confirmed the de crease, the protein electrophoretic profiles revealed that iron-deficient cells had less protein bands, with the increase of 2,2′ Dipyridyl , the protein bands was more and more less. And differently, iron deficiency also caused an increase of ROS (Reactive Oxygen Species)and SOD activity, it suggests that iron deficiency led to oxidative stress, which generally occured under high-iron conditions.

  14. Genes encoding the alpha, gamma, delta, and four F0 subunits of ATP synthase constitute an operon in the cyanobacterium Anabaena sp. strain PCC 7120.

    OpenAIRE

    McCarn, D F; R A Whitaker; Alam, J; Vrba, J M; Curtis, S E

    1988-01-01

    A cluster of genes encoding subunits of ATP synthase of Anabaena sp. strain PCC 7120 was cloned, and the nucleotide sequences of the genes were determined. This cluster, denoted atp1, consists of four F0 genes and three F1 genes encoding the subunits a (atpI), c (atpH), b' (atpG), b (atpF), delta (atpD), alpha (aptA), and gamma (atpC) in that order. Closely linked upstream of the ATP synthase subunit genes is an open reading frame denoted gene 1, which is equivalent to the uncI gene of Escher...

  15. Construction of shuttle, expression vector of human tumor necrosis factor alpha (hTNF-α) gene and its expression in a cyanobacterium, Anabaena sp. PCC 7120

    Institute of Scientific and Technical Information of China (English)

    刘凤龙; 施定基; 商之狄; 邵宁; 徐旭东; 钟泽璞; 张宏斌; 吴锦银; 王捷; 江悦华; 赵树进; 林晨; 张雪艳; 吴旻; 彭国宏; 张海霞; 曾呈奎

    1999-01-01

    The construction of the shuttle, expression vector of human tumor necrosis factor alpha (hTNF-a) gene and its expression in a cyanobacterium Anabaena sp. PCC 7120 was reported. The 700-bp hTNF cDNA fragments have been recovered from plasmid pRL-rhTNF, then inserted downstream of the promoter PpsbA in the plasmid pRL439. The resultant intermediary plasmid pRL-TC has further been combined with the shuttle vector pDC-8 to get the shuttle, expression vector pDC-TNF. The expression of the rhTNF gene in Escherichia coli has been analyzed by SDS-PAGE and thin-layer scanning, and the results show that the expressed TNF protein with these two vectors is 16.9 percent (pRL-TC) and 15.0 percent (pDC-TNF) of the total proteins in the cells, respectively, while the expression level of TNF gene in plasmid pRL-rhTNF is only 11.8 percent. Combined with the participation of the conjugal and helper plasmids, pDC-TNF has been introduced into Anabaena sp PCC 7120 by triparental conjugative transfer, and the stable transgenic

  16. in-silico analysis suggests alterations in the function of XisA protein as a possible mechanism of butachlor toxicity in the nitrogen fixing cyanobacterium Anabaena sp. PCC 7120

    OpenAIRE

    Singh, Shilpi; Singh, Prem Pal

    2013-01-01

    Butachlor, a commonly used herbicide adversely affects the nitrogen fixing capability of Anabaena, an acclaimed nitrogen fixer in the Indian paddy fields. The nitrogen fixation in Anabaena is triggered by the excision of nifD element by xisA gene leading to rearrangement of nifD forming nifHDK operon in the heterocyst of Anabaena sp. PCC7120. Functional elucidation adjudged through in-silico analysis revealed that xisA belongs to integrase family of tyrosine recombinase. The predicted functio...

  17. Directional RNA deep sequencing sheds new light on the transcriptional response of Anabaena sp. strain PCC 7120 to combined-nitrogen deprivation

    Directory of Open Access Journals (Sweden)

    Head Steven R

    2011-06-01

    Full Text Available Abstract Background Cyanobacteria are potential sources of renewable chemicals and biofuels and serve as model organisms for bacterial photosynthesis, nitrogen fixation, and responses to environmental changes. Anabaena (Nostoc sp. strain PCC 7120 (hereafter Anabaena is a multicellular filamentous cyanobacterium that can "fix" atmospheric nitrogen into ammonia when grown in the absence of a source of combined nitrogen. Because the nitrogenase enzyme is oxygen sensitive, Anabaena forms specialized cells called heterocysts that create a microoxic environment for nitrogen fixation. We have employed directional RNA-seq to map the Anabaena transcriptome during vegetative cell growth and in response to combined-nitrogen deprivation, which induces filaments to undergo heterocyst development. Our data provide an unprecedented view of transcriptional changes in Anabaena filaments during the induction of heterocyst development and transition to diazotrophic growth. Results Using the Illumina short read platform and a directional RNA-seq protocol, we obtained deep sequencing data for RNA extracted from filaments at 0, 6, 12, and 21 hours after the removal of combined nitrogen. The RNA-seq data provided information on transcript abundance and boundaries for the entire transcriptome. From these data, we detected novel antisense transcripts within the UTRs (untranslated regions and coding regions of key genes involved in heterocyst development, suggesting that antisense RNAs may be important regulators of the nitrogen response. In addition, many 5' UTRs were longer than anticipated, sometimes extending into upstream open reading frames (ORFs, and operons often showed complex structure and regulation. Finally, many genes that had not been previously identified as being involved in heterocyst development showed regulation, providing new candidates for future studies in this model organism. Conclusions Directional RNA-seq data were obtained that provide

  18. 鱼腥蓝细菌PCC7120铁吸收机制%Iron Uptake by Anabaena sp.Strain PCC7120

    Institute of Scientific and Technical Information of China (English)

    董妍玲; 潘学武

    2012-01-01

    As a cofactor in photosynthesis, respiration and nitrogen fixation, Iron is essential for cyanobacteria, and iron deficiency would affect the productivity. Iron is present in oxic ecosystems as insoluble iron (III) oxide minerals and thus is not readily available for living organisms to acquire and use. Under iron-limiting conditions, siderophores are exported from the Anabaena cell, where they chelate ferric ions in the environment. Specific ferric-siderophore complexes are recognized by cognate outer-membrane transporters, which initiate the process of iron transport into the cell where the iron becomes available for metabolic functions. Recent progress of siderophores including the types and their biosynthetic pathway was summarized. The components of the putative iron transport system was analyzed. The regulation mechanism of iron uptake was also discussed. This review would provide new evidence for advanced research on iron uptake by Anabaena.%铁离子是鱼腥蓝细菌PCC7120进行呼吸作用、光合作用和固氮作用中相关酶的重要辅基之一,缺铁将严重影响蓝细菌的生存.富氧的生态环境中铁通常以不溶的Fe3+形式存在,不易被细胞吸收利用.低铁条件下,鱼腥蓝细菌PCC7120分泌能螯合铁离子的嗜铁素,通过外膜上相应的转运体将嗜铁素-铁复合物转运到细胞内.综述了近年来在嗜铁素的种类及其生物合成途径、铁吸收系统的组成和功能等方面的最新进展,分析了铁吸收系统的调控机制,为进一步开展鱼腥蓝细菌铁吸收机制的研究提供依据.

  19. Treatment with moderate concentrations of NaHSO{sub 3} enhances photobiological H{sub 2} production in the cyanobacterium Anabaena sp. strain PCC 7120

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lianjun; Chen, Ming; Wei, Lanzhen; Gao, Fudan; Lv, Zhongxian; Wang, Quanxi; Ma, Weimin [College of Life and Environment Sciences, Shanghai Normal University, Guilin Road 100, Shanghai 200234 (China)

    2010-12-15

    In cyanobacteria, treatment with low concentrations of NaHSO{sub 3} can enhance photosynthetic efficiency, whereas NaHSO{sub 3} in high amounts often inhibits cell growth and photosynthesis may even cause death. In the present study, our results showed that treatment with moderate concentrations of NaHSO{sub 3} considerably improved the yield of photobiological H{sub 2} production in the filamentous N{sub 2}-fixing cyanobacterium Anabaena sp. strain PCC 7120. Under steady state conditions, the accumulated H{sub 2} levels in cells treated with 1 mM NaHSO{sub 3} were approximately 10 times higher than that in untreated cells. Such improvement occurred in heterocysts and was most likely caused by increases in the expression and activity of nitrogenase. The effects of treatment with low, moderate, and high concentrations of NaHSO{sub 3} in cyanobacteria were proposed on the basis of the results obtained in the present study and from previous knowledge. (author)

  20. Characterization and responses to environmental cues of a photosynthetic antenna-deficient mutant of the filamentous cyanobacterium Anabaena sp. PCC 7120.

    Science.gov (United States)

    Leganés, Francisco; Martínez-Granero, Francisco; Muñoz-Martín, M Ángeles; Marco, Eduardo; Jorge, Alberto; Carvajal, Laura; Vida, Teresa; González-Pleiter, Miguel; Fernández-Piñas, Francisca

    2014-07-01

    The cyanobacterial phycobilisome (PBS) is a giant pigment-protein complex which harvests light energy for photosynthesis and comprises two structures: a core and peripheral rods. Most studies on PBS structure and function are based on mutants of unicellular strains. In this report, we describe the phenotypic and genetic characterization of a transposon mutant of the filamentous Anabaena sp. strain PCC 7120, denoted LC1, which cannot synthesize the phycobiliprotein phycocyanin (PC), the main component of the rods; in this mutant, the transposon had inserted into the cpcB gene (orf alr0528) which putatively encodes PC-β chain. Mutant LC1 was able to synthesize phycoerythrocyanin (PEC), a phycobiliprotein (PBP) located at the terminal region of the rods; but in the absence of PC, PEC did not attach to the PBSs that only retained the allophycocyanin (APC) core; ferredoxin: NADP+-oxidoreductase (FNR) that is associated with the PBS in the wild type, was not found in isolated PBSs from LC1. The performance of the mutant exposed to different environmental conditions was evaluated. The mutant phenotype was successfully complemented by cloning and transfer of the wild type complete cpc operon to mutant LC1. Interestingly, LC1 compensated its mutation by significantly increasing the number of its core-PBS and the effective quantum yield of photosystem II (PSII) photochemistry; this feature suggests a more efficient energy conversion in the mutant which may be useful for biotechnological applications. PMID:24913049

  1. Effects of environment factors on the culture of recombinant Anabaena sp. PCC7120%环境因子对转基因鱼腥藻培养的影响

    Institute of Scientific and Technical Information of China (English)

    张晨; 刘志伟; 郭勇

    2002-01-01

    摇瓶中对转TNF-α基因鱼腥藻7120(Anabaena sp.PCC7120,pDC-TNF)混合培养条件进行了研究,在含蔗糖9 g/L,NaNO3 2.25 g/L的BG-11培养基混合培养时,得到最适培养条件接种量5%,光照强度为1000Lux,光/暗周期(光照时间/黑暗时间)12h/12h,温度25~30℃,自然初始pH值,100mL摇瓶装液量40mL,转基因鱼腥藻15d生物量可达到3g/L以上,可溶性蛋白含量接近30%,TNF表达水平大于22%,与自养相比,生物量增加82.06%,表达水平提高38.79%.证明混合营养型培养是转rhTNF-α基因鱼腥藻7120实现高密度、高表达培养的途径.

  2. Expression, nucleotide sequence and mutational analysis of two open reading frames in the nif gene region of Anabaena sp. strain PCC7120.

    Science.gov (United States)

    Borthakur, D; Basche, M; Buikema, W J; Borthakur, P B; Haselkorn, R

    1990-04-01

    A 1.8 kb transcript corresponding to a region of the Anabaena 7120 chromosome 4 kb downstream of the nifHDK operon appears 12-18 h after heterocyst induction. The DNA corresponding to this transcript was sequenced and found to contain two open reading frames, designated ORF 1 and ORF 2. Two polypeptides, of 30 kDa and 13 kDa, encoded by these ORFs were expressed in Escherichia coli. An apparent start site for the transcript, detected by S1 nuclease protection, was located 42 bp upstream of the ATG start codon of ORF 1. ORF 2 shows strong sequence similarity to ORF 6 in the nif gene region of Azotobacter vinelandii. ORF 1 was interrupted using a 1.4 kb neomycin resistance cassette and the resulting mutant grew very slowly on medium lacking combined nitrogen. The mutant had 45% of wild-type acetylene reduction activity, which could be complemented by a 2.8 kb EcoRI fragment of wild-type Anabaena DNA containing only ORF 1 and ORF 2. Thus, one or both of these ORFs is required for efficient nitrogen fixation in Anabaena. PMID:2115111

  3. A novel alkyl hydroperoxidase (AhpD) of Anabaena PCC7120 confers abiotic stress tolerance in Escherichia coli.

    Science.gov (United States)

    Shrivastava, Alok Kumar; Singh, Shilpi; Singh, Prashant Kumar; Pandey, Sarita; Rai, L C

    2015-01-01

    In silico analysis together with cloning, molecular characterization and heterologous expression reports that the hypothetical protein All5371 of Anabaena sp. PCC7120 is a novel hydroperoxide scavenging protein similar to AhpD of bacteria. The presence of E(X)11CX HC(X)3H motif in All5371 confers peroxidase activity and closeness to bacterial AhpD which is also reflected by its highest 3D structure homology with Rhodospirillum rubrum AhpD. Heterologous expression of all5371 complimented for ahpC and conferred resistance in MJF178 strain (ahpCF::Km) of Escherichia coli. All5371 reduced the organic peroxide more efficiently than inorganic peroxide and the recombinant E. coli strain following exposure to H2O2, CdCl2, CuCl2, heat, UV-B and carbofuron registered increased growth over wild-type and mutant E. coli transformed with empty vector. Appreciable expression of all5371 in Anabaena sp. PCC7120 as measured by qRT-PCR under selected stresses and their tolerance against H2O2, tBOOH, CuOOH and menadione attested its role in stress tolerance. In view of the above, All5371 of Anabaena PCC7120 emerged as a new hydroperoxide detoxifying protein. PMID:25391500

  4. Regulation of hepA of Anabaena sp. Strain PCC 7120 by Elements 5′ from the Gene and by hepK

    Science.gov (United States)

    Zhu, Jinsong; Kong, Renqiu; Wolk, C. Peter

    1998-01-01

    In Anabaena spp., synthesis of the heterocyst envelope polysaccharide, required if the cell is to fix dinitrogen under aerobic conditions, is dependent on the gene hepA. A transcriptional start site of hepA was localized 104 bp 5′ from its translational initiation codon. A 765-bp open reading frame, denoted hepC, was found farther upstream. Inactivation of hepC led to constitutive expression of hepA and prevented the synthesis of heterocyst envelope polysaccharide. However, the glycolipid layer of the heterocyst envelope was synthesized. A hepK mutation blocked both the synthesis of the heterocyst envelope polysaccharide and induction of hepA. The predicted product of hepK resembles a sensory protein-histidine kinase of a two-component regulatory system. Analysis of the region between hepC and hepA indicated that DNA sequences required for the induction of hepA upon nitrogen deprivation are present between bp −574 and −440 and between bp −340 and −169 relative to the transcriptional start site of hepA. Gel mobility shift assays provided evidence that one or more proteins bind specifically to the latter sequence. The Fox box sequence downstream from hepA appeared inessential for the induction of hepA. PMID:9696774

  5. Mutations in Genes patA and patL of Anabaena sp. Strain PCC 7120 Result in Similar Phenotypes, and the Proteins Encoded by Those Genes May Interact ▿

    OpenAIRE

    Liu, Jinjie; Wolk, C. Peter

    2011-01-01

    PatA resembles a response regulator protein with a defective DNA-binding domain, and PatL (All3305) is a pentapeptide repeat protein. A yeast two-hybrid library identified PatL as a protein with which PatA may interact. Heterocysts of patA and patL Anabaena sp. form nearly exclusively terminally in long filaments, further linking the genes.

  6. Crystallization and preliminary X-ray crystallographic studies of O-methyltransferase from Anabaena PCC 7120

    International Nuclear Information System (INIS)

    The O-methyltransferase (OMT) from the Anabaena PCC 7120 has been overexpressed in a soluble form in E. coli, purified and crystallized. The crystals belonged to space group C2221 and diffracted to 2.4 Å resolution. O-Methyltransferase (OMT) is a ubiquitous enzyme that exists in bacteria, plants and humans and catalyzes a methyl-transfer reaction using S-adenosyl-l-methionine as a methyl donor and a wide range of phenolics as acceptors. To investigate the structure and function of OMTs, omt from Anabaena PCC 7120 was cloned into expression vector pET21a and expressed in a soluble form in Escherichia coli strain BL21 (DE3). The recombinant OMT protein was purified to homogeneity using a two-step strategy. Crystals of OMT that diffracted to a resolution of 2.4 Å were obtained using the hanging-drop vapour-diffusion method. The crystals belonged to space group C2221, with unit-cell parameters a = 131.620, b = 227.994, c = 150.777 Å, α = β = γ = 90°. There are eight molecules per asymmetric unit

  7. Taxonomy Icon Data: Synechocystis sp.PCC 6803 [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available Synechocystis_sp_PCC_6803_NL.png Synechocystis_sp_PCC_6803_S.png Synechocystis_sp_PCC_6803_NS.png http://biosciencedbc.jp/taxonomy..._icon/icon.cgi?i=Synechocystis+sp%2ePCC+6803&t=L http://biosciencedbc.jp/taxonomy_ico...n/icon.cgi?i=Synechocystis+sp%2ePCC+6803&t=NL http://biosciencedbc.jp/taxonomy_ic...on/icon.cgi?i=Synechocystis+sp%2ePCC+6803&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Synechocystis...+sp%2ePCC+6803&t=NS http://togodb.biosciencedbc.jp/togodb/view/taxonomy_icon_comment_en?species_id=69 ...

  8. Regulation of Fructose Transport and Its Effect on Fructose Toxicity in Anabaena spp.▿ †

    OpenAIRE

    Ungerer, Justin L.; Pratte, Brenda S.; Thiel, Teresa

    2008-01-01

    Anabaena variabilis grows heterotrophically using fructose, while the close relative Anabaena sp. strain PCC 7120 does not. Introduction of a cluster of genes encoding a putative ABC transporter, herein named frtRABC, into Anabaena sp. strain PCC 7120 on a replicating plasmid allowed that strain to grow in the dark using fructose, indicating that these genes are necessary and sufficient for heterotrophic growth. FrtR, a putative LacI-like regulatory protein, was essential for heterotrophic gr...

  9. The susceptibility of five African Anopheles species to Anabaena PCC 7120 expressing Bacillus thuringiensis subsp. israelensis mosquitocidal cry genes

    Directory of Open Access Journals (Sweden)

    Ketseoglou Irene

    2012-10-01

    Full Text Available Abstract Background Malaria, one of the leading causes of death in Africa, is transmitted by the bite of an infected female Anopheles mosquito. Problems associated with the development of resistance to chemical insecticides and concerns about the non-target effects and persistence of chemical insecticides have prompted the development of environmentally friendly mosquito control agents. The aim of this study was to evaluate the larvicidal activity of a genetically engineered cyanobacterium, Anabaena PCC 7120#11, against five African Anopheles species in laboratory bioassays. Findings There were significant differences in the susceptibility of the anopheline species to PCC 7120#11. The ranking of the larvicidal activity of PCC 7120#11 against species in the An. gambiae complex was: An. merus An. arabiensis An. gambiae An. quadriannulatus, where 50. The LC50 of PCC 7120#11 against the important malaria vectors An. gambiae and An. arabiensis was 12.3 × 105 cells/ml and 8.10 × 105 cells/ml, respectively. PCC 7120#11 was not effective against An. funestus, with less than 50% mortality obtained at concentrations as high as 3.20 × 107 cells/ml. Conclusions PCC 7120#11 exhibited good larvicidal activity against larvae of the An. gambiae complex, but relatively weak larvicidal activity against An. funestus. The study has highlighted the importance of evaluating a novel mosquitocidal agent against a range of malaria vectors so as to obtain a clear understanding of the agent’s spectrum of activity and potential as a vector control agent.

  10. Expression of holo-proteorhodopsin in Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Chen, Que; van der Steen, Jeroen B; Dekker, Henk L; Ganapathy, Srividya; de Grip, Willem J; Hellingwerf, Klaas J

    2016-05-01

    Retinal-based photosynthesis may contribute to the free energy conversion needed for growth of an organism carrying out oxygenic photosynthesis, like a cyanobacterium. After optimization, this may even enhance the overall efficiency of phototrophic growth of such organisms in sustainability applications. As a first step towards this, we here report on functional expression of the archetype proteorhodopsin in Synechocystis sp. PCC 6803. Upon use of the moderate-strength psbA2 promoter, holo-proteorhodopsin is expressed in this cyanobacterium, at a level of up to 10(5) molecules per cell, presumably in a hexameric quaternary structure, and with approximately equal distribution (on a protein-content basis) over the thylakoid and the cytoplasmic membrane fraction. These results also demonstrate that Synechocystis sp. PCC 6803 has the capacity to synthesize all-trans-retinal. Expressing a substantial amount of a heterologous opsin membrane protein causes a substantial growth retardation Synechocystis, as is clear from a strain expressing PROPS, a non-pumping mutant derivative of proteorhodopsin. Relative to this latter strain, proteorhodopsin expression, however, measurably stimulates its growth. PMID:26869136

  11. 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.

  12. A tightly inducible riboswitch system in Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Ohbayashi, Ryudo; Akai, Hideto; Yoshikawa, Hirofumi; Hess, Wolfgang R; Watanabe, Satoru

    2016-07-14

    Cyanobacteria are photosynthetic microorganisms that serve as experimental model organisms for the study of photosynthesis, environmental stress responses, and the production of biofuels. Genetic tools for bioengineering have been developed as a result of such studies. However, there is still room for improvement for the tight control of experimental protein expression in these microorganisms. Here, we describe an expression system controlled by a theophylline-responsive riboswitch that we have constructed in the cyanobacterium Synechocystis sp. PCC 6803. We demonstrate that, in response to different theophylline concentrations, this riboswitch can tightly control green fluorescence protein expression in Synechocystis. Thus, this system is useful as a tool for genetic engineering and the synthetic biology of cyanobacteria. PMID:27250662

  13. Improved Free Fatty Acid Production in Cyanobacteria with Synechococcus sp. PCC 7002 as Host

    Directory of Open Access Journals (Sweden)

    Anne M Ruffing

    2014-05-01

    Full Text Available 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 RuBisCO. Overexpression of non-native RuBisCO subunits (rbcLS from a psbAI promoter resulted in more than a 3-fold increase in FFA production, with excreted FFA concentrations reaching greater than 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.

  14. 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

  15. DL-7-azatryptophan and citrulline metabolism in the cyanobacterium Anabaena sp. strain 1F

    International Nuclear Information System (INIS)

    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-[14C]glutamate from 2-keto-[1-14C]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 [14C]bicarbonate and L-[1-14C]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

  16. Heterologous expression of Anabaena PCC 7120 all3940 (a Dps family gene) protects Escherichia coli from nutrient limitation and abiotic stresses

    International Nuclear Information System (INIS)

    This study presents first hand data on the cloning and heterologous expression of Anabaena PCC 7120 all3940 (a dps family gene) in combating nutrients limitation and multiple abiotic stresses. The Escherichia coli transformed with pGEX-5X-2-all3940 construct when subjected to iron, carbon, nitrogen, phosphorus limitation and carbofuron, copper, UV-B, heat, salt and cadmium stress registered significant increase in growth over the cells transformed with empty vector under iron (0%), carbon (0.05%), nitrogen (3.7 mM) and phosphorus (2 mM) limitation and carbofuron (0.025 mg ml-1), CuCl2 (1 mM), UV-B (10 min), heat (47 oC), NaCl (6% w/v) and CdCl2 (4 mM) stress. Enhanced expression of all3940 gene measured by semi-quantitative RT-PCR at different time points under above mentioned treatments clearly demonstrates its role in tolerance against aforesaid abiotic stresses. This study opens the gate for developing transgenic cyanobacteria capable of growing successfully under above mentioned stresses.

  17. Biological hydrogen production by Anabaena sp. – Yield, energy and CO2 analysis including fermentative biomass recovery

    OpenAIRE

    Ferreira, Ana F.; Marques, Ana C.; Batista, Ana Paula; Marques, Paula Alexandra; de Gouveia, L.; Carla M. Silva

    2012-01-01

    This paper presents laboratory results of biological production of hydrogen by photoautrotophic cyanobacterium Anabaena sp. Additional hydrogen production from residual Cyanobacteria fermentation was achieved by Enterobacter aerogenes bacteria. The authors evaluated the yield of H2 production, the energy consumption and CO2 emissions and the technological bottlenecks and possible improvements of the whole energy and CO2 emission chain. The authors did not attempt to extrapolate the results to...

  18. CpcM posttranslationally methylates asparagine-71/72 of phycobiliprotein beta subunits in Synechococcus sp. strain PCC 7002 and Synechocystis sp. strain PCC 6803.

    Science.gov (United States)

    Shen, Gaozhong; Leonard, Heidi S; Schluchter, Wendy M; Bryant, Donald A

    2008-07-01

    Cyanobacteria produce phycobilisomes, which are macromolecular light-harvesting complexes mostly assembled from phycobiliproteins. Phycobiliprotein beta subunits contain a highly conserved gamma-N-methylasparagine residue, which results from the posttranslational modification of Asn71/72. Through comparative genomic analyses, we identified a gene, denoted cpcM, that (i) encodes a protein with sequence similarity to other S-adenosylmethionine-dependent methyltransferases, (ii) is found in all sequenced cyanobacterial genomes, and (iii) often occurs near genes encoding phycobiliproteins in cyanobacterial genomes. The cpcM genes of Synechococcus sp. strain PCC 7002 and Synechocystis sp. strain PCC 6803 were insertionally inactivated. Mass spectrometric analyses of phycobiliproteins isolated from the mutants confirmed that the CpcB, ApcB, and ApcF were 14 Da lighter than their wild-type counterparts. Trypsin digestion and mass analyses of phycobiliproteins isolated from the mutants showed that tryptic peptides from phycocyanin that included Asn72 were also 14 Da lighter than the equivalent peptides from wild-type strains. Thus, CpcM is the methyltransferase that modifies the amide nitrogen of Asn71/72 of CpcB, ApcB, and ApcF. When cells were grown at low light intensity, the cpcM mutants were phenotypically similar to the wild-type strains. However, the mutants were sensitive to high-light stress, and the cpcM mutant of Synechocystis sp. strain PCC 6803 was unable to grow at moderately high light intensities. Fluorescence emission measurements showed that the ability to perform state transitions was impaired in the cpcM mutants and suggested that energy transfer from phycobiliproteins to the photosystems was also less efficient. The possible functions of asparagine N methylation of phycobiliproteins are discussed. PMID:18469097

  19. The putative siderophore-dependent iron transport network in Anabaena sp. PCC 7120

    OpenAIRE

    Stevanovic, Mara

    2015-01-01

    Cyanobacteria belong to the most widely distributed microorganisms in the biosphere and contribute significantly to global primary production. Their metabolism is based on oxygenic photosynthesis and some cyanobacteria can fix elemental nitrogen. Obligate photosynthetic diazotrophs have a particularly high iron demand in comparison to heterotrophic bacteria. Nevertheless the understanding of iron acquisition in cyanobacteria is just beginning to emerge. Iron acquisition in bacteria comprises ...

  20. Cryo-imaging of photosystems and phycobilisomes in Anabaena sp PCC 7120 cells

    Czech Academy of Sciences Publication Activity Database

    Steinbach, Gabor; Schubert, F.; Kaňa, Radek

    2015-01-01

    Roč. 152, NOV 2015 (2015), s. 395-399. ISSN 1011-1344 R&D Projects: GA ČR GAP501/12/0304; GA MŠk EE2.3.30.0059; GA MŠk ED2.1.00/03.0110; GA MŠk LO1416 Institutional support: RVO:61388971 Keywords : Confocal microscopy * Cryogenic microscopy * Cyanobacteria Subject RIV: CE - Biochemistry Impact factor: 2.960, year: 2014

  1. Detection of reactive oxygen species (ROS) by the oxidant-sensing probe 2',7'-dichlorodihydrofluorescein diacetate in the cyanobacterium Anabaena variabilis PCC 7937

    Energy Technology Data Exchange (ETDEWEB)

    Rastogi, Rajesh P. [Department of Biology, Friedrich-Alexander University Erlangen-Nuremberg, Staudtstrasse 5, D-91058 Erlangen (Germany); Laboratory of Photobiology and Molecular Microbiology, Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi 221005 (India); Singh, Shailendra P.; Haeder, Donat-P. [Department of Biology, Friedrich-Alexander University Erlangen-Nuremberg, Staudtstrasse 5, D-91058 Erlangen (Germany); Sinha, Rajeshwar P., E-mail: r.p.sinha@gmx.net [Laboratory of Photobiology and Molecular Microbiology, Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi 221005 (India)

    2010-07-02

    The generation of reactive oxygen species (ROS) under simulated solar radiation (UV-B: 0.30 Wm{sup -2}, UV-A: 25.70 Wm{sup -2} and PAR: 118.06 Wm{sup -2}) was studied in the cyanobacterium Anabaena variabilis PCC 7937 using the oxidant-sensing fluorescent probe 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA). DCFH-DA is a nonpolar dye, converted into the polar derivative DCFH by cellular esterases that are nonfluorescent but switched to highly fluorescent DCF when oxidized by intracellular ROS and other peroxides. The images obtained from the fluorescence microscope after 12 h of irradiation showed green fluorescence from cells covered with 295, 320 or 395 nm cut-off filters, indicating the generation of ROS in all treatments. However, the green/red fluorescence ratio obtained from fluorescence microscopic analysis showed the highest generation of ROS after UV-B radiation in comparison to PAR or UV-A radiation. Production of ROS was also measured by a spectrofluorophotometer and results obtained supported the results of fluorescence microscopy. Low levels of ROS were detected at the start (0 h) of the experiment showing that they are generated even during normal metabolism. This study also showed that UV-B radiation causes the fragmentation of the cyanobacterial filaments which could be due to the observed oxidative stress. This is the first report for the detection of intracellular ROS in a cyanobacterium by fluorescence microscopy using DCFH-DA and thereby suggesting the applicability of this method in the study of in vivo generation of ROS.

  2. Detection of reactive oxygen species (ROS) by the oxidant-sensing probe 2',7'-dichlorodihydrofluorescein diacetate in the cyanobacterium Anabaena variabilis PCC 7937

    International Nuclear Information System (INIS)

    The generation of reactive oxygen species (ROS) under simulated solar radiation (UV-B: 0.30 Wm-2, UV-A: 25.70 Wm-2 and PAR: 118.06 Wm-2) was studied in the cyanobacterium Anabaena variabilis PCC 7937 using the oxidant-sensing fluorescent probe 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA). DCFH-DA is a nonpolar dye, converted into the polar derivative DCFH by cellular esterases that are nonfluorescent but switched to highly fluorescent DCF when oxidized by intracellular ROS and other peroxides. The images obtained from the fluorescence microscope after 12 h of irradiation showed green fluorescence from cells covered with 295, 320 or 395 nm cut-off filters, indicating the generation of ROS in all treatments. However, the green/red fluorescence ratio obtained from fluorescence microscopic analysis showed the highest generation of ROS after UV-B radiation in comparison to PAR or UV-A radiation. Production of ROS was also measured by a spectrofluorophotometer and results obtained supported the results of fluorescence microscopy. Low levels of ROS were detected at the start (0 h) of the experiment showing that they are generated even during normal metabolism. This study also showed that UV-B radiation causes the fragmentation of the cyanobacterial filaments which could be due to the observed oxidative stress. This is the first report for the detection of intracellular ROS in a cyanobacterium by fluorescence microscopy using DCFH-DA and thereby suggesting the applicability of this method in the study of in vivo generation of ROS.

  3. Myxoxanthophyll Is Required for Normal Cell Wall Structure and Thylakoid Organization in the Cyanobacterium Synechocystis sp. Strain PCC 6803

    OpenAIRE

    Mohamed, Hatem E.; Allison M. L. van de Meene; Roberson, Robert W.; Vermaas, Wim F. J.

    2005-01-01

    Myxoxanthophyll is a carotenoid glycoside in cyanobacteria that is of unknown biological significance. The sugar moiety of myxoxanthophyll in Synechocystis sp. strain PCC 6803 was identified as dimethyl fucose. The open reading frame sll1213 encoding a fucose synthetase orthologue was deleted to probe the role of fucose and to determine the biological significance of myxoxanthophyll in Synechocystis sp. strain PCC 6803. Upon deletion of sll1213, a pleiotropic phenotype was obtained: when prop...

  4. Characterization of Chlamydomonas reinhardtii phosphatidylglycerophosphate synthase in Synechocystis sp. PCC 6803

    OpenAIRE

    Hung, Chun-Hsien; Endo, Kaichiro; Kobayashi, Koichi; Nakamura, Yuki; Wada, Hajime

    2015-01-01

    Phosphatidylglycerol (PG) is an indispensable phospholipid class with photosynthetic function in plants and cyanobacteria. However, its biosynthesis in eukaryotic green microalgae is poorly studied. Here, we report the isolation and characterization of two homologs (CrPGP1 and CrPGP2) of phosphatidylglycerophosphate synthase (PGPS), the rate-limiting enzyme in PG biosynthesis, in Chlamydomonas reinhardtii. Heterologous complementation of Synechocystis sp. PCC 6803 pgsA mutant by CrPGP1 and Cr...

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

    OpenAIRE

    Zhang, Yanan; Niu, Xiangfeng; Shi, Mengliang; Pei, Guangsheng; Zhang, Xiaoqing; Chen, Lei; Zhang, Weiwen

    2015-01-01

    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 allo...

  6. BMAA Inhibits Nitrogen Fixation in the Cyanobacterium Nostoc sp. PCC 7120

    OpenAIRE

    Birgitta Bergman; Ulla Rasmussen; Johan Eriksson; Sven Erasmie; Narin Celepli; Lotta Berntzon

    2013-01-01

    Cyanobacteria produce a range of secondary metabolites, one being the neurotoxic non-protein amino acid β-N-methylamino-L-alanine (BMAA), proposed to be a causative agent of human neurodegeneration. As for most cyanotoxins, the function of BMAA in cyanobacteria is unknown. Here, we examined the effects of BMAA on the physiology of the filamentous nitrogen-fixing cyanobacterium Nostoc sp. PCC 7120. Our data show that exogenously applied BMAA rapidly inhibits nitrogenase activity (acetylene red...

  7. Production of squalene in Synechocystis sp. PCC 6803.

    Directory of Open Access Journals (Sweden)

    Elias Englund

    Full Text Available In recent years, there has been an increased interest in the research and development of sustainable alternatives to fossil fuels. Using photosynthetic microorganisms to produce such alternatives is advantageous, since they can achieve direct conversion of carbon dioxide from the atmosphere into the desired product, using sunlight as the energy source. Squalene is a naturally occurring 30-carbon isoprenoid, which has commercial use in cosmetics and in vaccines. If it could be produced sustainably on a large scale, it could also be used instead of petroleum as a raw material for fuels and as feedstock for the chemical industry. The unicellular cyanobacterium Synechocystis PCC 6803 possesses a gene, slr2089, predicted to encode squalene hopene cyclase (Shc, an enzyme converting squalene into hopene, the substrate for forming hopanoids. Through inactivation of slr2089 (shc, we explored the possibility to produce squalene using cyanobacteria. The inactivation led to accumulation of squalene, to a level over 70 times higher than in wild type cells, reaching 0.67 mg OD750(-1 L(-1. We did not observe any significant growth deficiency in the Δshc strain compared to the wild type Synechocystis, even at high light conditions, suggesting that the observed squalene accumulation was not detrimental to growth, and that formation of hopene by Shc is not crucial for growth under normal conditions, nor for high-light stress tolerance. Effects of different light intensities and growth stages on squalene accumulation in the Δshc strain were investigated. We also identified a gene, sll0513, as a putative squalene synthase in Synechocystis, and verified its function by inactivation. In this work, we show that it is possible to use the cyanobacterium Synechocystis to generate squalene, a hydrocarbon of commercial interest and a potential biofuel. We also report the first identification of a squalene hopene cyclase, and the second identification of squalene synthase

  8. In vitro antibacterial evaluation of Anabaena sp. against several clinically significant microflora and HPTLC analysis of its active crude extracts

    Directory of Open Access Journals (Sweden)

    Chauhan Abhishek

    2010-01-01

    Full Text Available The present study was conducted to evaluate the possible antibacterial activity of Anabaena extracts. Anabaena was isolated from a natural source and cultured in vitro. after suitable growth, cyanobacterial culture was harvested using different solvents. Extracts, thus prepared, were evaluated for their antibacterial potential by agar-well diffusion assay against bacterial species of clinical significance. MIC values were determined further to check the concentration ranges for significant inhibition. HPTLC analysis was done to separate the components of active crude extract in an attempt to identify the bio-active chemical entity. Methanol extract exhibited more potent activity than that of hexane and ethyl acetate extracts. No inhibitory effect was found against Pseudomonas aeruginosa, Salmonella typhi, and Klebsiella pneumoniae. Staphylococcus aureus required about 256 μg/ml of the crude methanol extract for effective inhibition. HPTLC evaluation at λ 254 nm was performed for the separation of a complex mixture of the methanol extract. The results provide evidence that Anabaena sp. extracts might indeed be potential sources of new antibacterial agents.

  9. Establishment of quantitative PCR methods for the quantification of geosmin-producing potential and Anabaena sp. in freshwater systems.

    Science.gov (United States)

    Su, Ming; Gaget, Virginie; Giglio, Steven; Burch, Michael; An, Wei; Yang, Min

    2013-06-15

    Geosmin has often been associated with off-flavor problems in drinking water with Anabaena sp. as the major producer. Rapid on-site detection of geosmin-producers as well as geosmin is important for a timely management response to potential off-flavor events. In this study, quantitative polymerase chain reaction (qPCR) methods were developed to detect the levels of Anabaena sp. and geosmin, respectively, by designing two PCR primer sets to quantify the rpoC1 gene (ARG) and geosmin synthase one (GSG) in Anabaena sp. in freshwater systems. The ARG density determined by qPCR assay is highly related to microscopic cell count (r(2) = 0.726, p < 0.001), and the limit of detection (LOD) and limit of quantification (LOQ) of the qPCR method were 0.02 pg and 0.2 pg of DNA, respectively. At the same time, the relationship between geosmin concentrations measured by gas chromatography-mass spectrometry (GC-MS) and GSG copies was also established (r(2) = 0.742, p < 0.001) with similar LOD and LOQ values. Using the two qPCR protocols, we succeeded in measuring different levels of ARG and GSG copies in different freshwater systems with high incidence environmental substrata and diverse ecological conditions, showing that the methods developed could be applied for environmental monitoring. Moreover, comparing to the microscopic count and GC-MS analytical methods, the qPCR methods can reduce the time-to-results from several days to a few hours and require considerably less traditional algal identification and taxonomic expertise. PMID:23622984

  10. 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

    2016-09-01

    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. PMID:27372425

  11. Molecular exploration of the highly radiation resistant cyanobacterium Arthrospira sp. PCC 8005

    Science.gov (United States)

    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

  12. 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.

  13. Interplay between Flavodiiron Proteins and Photorespiration in Synechocystis sp. PCC 6803*

    OpenAIRE

    Allahverdiyeva, Yagut; Ermakova, Maria; Eisenhut, Marion; Zhang, Pengpeng; Richaud, Pierre; Hagemann, Martin; Cournac, Laurent; Aro, Eva-Mari

    2011-01-01

    Flavodiiron (Flv) proteins are involved in detoxification of O2 and NO in anaerobic bacteria and archaea. Cyanobacterial Flv proteins, on the contrary, function in oxygenic environment and possess an extra NAD(P)H:flavin oxidoreductase module. Synechocystis sp. PCC 6803 has four genes (sll1521, sll0219, sll0550, and sll0217) encoding Flv proteins (Flv1, Flv2, Flv3, and Flv4). Previous in vitro studies with recombinant Flv3 protein from Synechocystis provided evidence that it functions as a NA...

  14. In Vivo Role of Catalase-Peroxidase in Synechocystis sp. Strain PCC 6803

    OpenAIRE

    Tichy, Martin; Vermaas, Wim

    1999-01-01

    The katG gene coding for the only catalase-peroxidase in the cyanobacterium Synechocystis sp. strain PCC 6803 was deleted in this organism. Although the rate of H2O2 decomposition was about 30 times lower in the ΔkatG mutant than in the wild type, the strain had a normal phenotype and its doubling time as well as its resistance to H2O2 and methyl viologen were indistinguishable from those of the wild type. The residual H2O2-scavenging capacity was more than sufficient to deal with the rate of...

  15. Enhancing biomass and ethanol production by increasing NADPH production in Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Choi, Yun-Nam; Park, Jong Moon

    2016-08-01

    This study demonstrates that increased NADPH production can improve biomass and ethanol production in cyanobacteria. We over-expressed the endogenous zwf gene, which encodes glucose-6-phosphate dehydrogenase of pentose phosphate pathway, in the model cyanobacterium Synechocystis sp. PCC 6803. zwf over-expression resulted in increased NADPH production, and promoted biomass production compared to the wild type in both autotrophic and mixotrophic conditions. Ethanol production pathway including NADPH-dependent alcohol dehydrogenase was also integrated with and without zwf over-expression. Excessive NADPH production by zwf over-expression could improve both biomass and ethanol production in the autotrophic conditions. PMID:26951740

  16. Transcription of the extended hyp-operon in Nostoc sp. strain PCC 7120

    Directory of Open Access Journals (Sweden)

    Lindblad Peter

    2008-04-01

    Full Text Available Abstract Background The maturation of hydrogenases into active enzymes is a complex process and e.g. a correctly assembled active site requires the involvement of at least seven proteins, encoded by hypABCDEF and a hydrogenase specific protease, encoded either by hupW or hoxW. The N2-fixing cyanobacterium Nostoc sp. strain PCC 7120 may contain both an uptake and a bidirectional hydrogenase. The present study addresses the presence and expression of hyp-genes in Nostoc sp. strain PCC 7120. Results RT-PCRs demonstrated that the six hyp-genes together with one ORF may be transcribed as a single operon. Transcriptional start points (TSPs were identified 280 bp upstream from hypF and 445 bp upstream of hypC, respectively, demonstrating the existence of several transcripts. In addition, five upstream ORFs located in between hupSL, encoding the small and large subunits of the uptake hydrogenase, and the hyp-operon, and two downstream ORFs from the hyp-genes were shown to be part of the same transcript unit. A third TSP was identified 45 bp upstream of asr0689, the first of five ORFs in this operon. The ORFs are annotated as encoding unknown proteins, with the exception of alr0692 which is identified as a NifU-like protein. Orthologues of the four ORFs asr0689-alr0692, with a highly conserved genomic arrangement positioned between hupSL, and the hyp genes are found in several other N2-fixing cyanobacteria, but are absent in non N2-fixing cyanobacteria with only the bidirectional hydrogenase. Short conserved sequences were found in six intergenic regions of the extended hyp-operon, appearing between 11 and 79 times in the genome. Conclusion This study demonstrated that five ORFs upstream of the hyp-gene cluster are co-transcribed with the hyp-genes, and identified three TSPs in the extended hyp-gene cluster in Nostoc sp. strain PCC 7120. This may indicate a function related to the assembly of a functional uptake hydrogenase, hypothetically in the

  17. 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-scale ...

  18. Ammonia triggers photodamage of photosystem II in the cyanobacterium Synechocystis sp. strain PCC 6803.

    Science.gov (United States)

    Drath, Miriam; Kloft, Nicole; Batschauer, Alfred; Marin, Kay; Novak, Jens; Forchhammer, Karl

    2008-05-01

    Ammonia has long been known to be toxic for many photosynthetic organisms; however, the target for its toxicity remains elusive. Here, we show that in the cyanobacterium Synechocystis sp. strain PCC 6803, ammonia triggers a rapid photodamage of photosystem II (PSII). Whereas wild-type cells can cope with this damage by turning on the FtsH2-dependent PSII repair cycle, the FtsH2-deficient mutant is highly sensitive and loses PSII activity at millimolar concentration of ammonia. Ammonia-triggered PSII destruction is light dependent and occurs already at low photon fluence rates. Experiments with monochromatic light showed that ammonia-promoted PSII photoinhibition is executed by wavebands known to directly destroy the manganese cluster in the PSII oxygen-evolving complex, suggesting that the oxygen-evolving complex may be a direct target for ammonia toxicity. PMID:18322144

  19. Ammonia Triggers Photodamage of Photosystem II in the Cyanobacterium Synechocystis sp. Strain PCC 68031[OA

    Science.gov (United States)

    Drath, Miriam; Kloft, Nicole; Batschauer, Alfred; Marin, Kay; Novak, Jens; Forchhammer, Karl

    2008-01-01

    Ammonia has long been known to be toxic for many photosynthetic organisms; however, the target for its toxicity remains elusive. Here, we show that in the cyanobacterium Synechocystis sp. strain PCC 6803, ammonia triggers a rapid photodamage of photosystem II (PSII). Whereas wild-type cells can cope with this damage by turning on the FtsH2-dependent PSII repair cycle, the FtsH2-deficient mutant is highly sensitive and loses PSII activity at millimolar concentration of ammonia. Ammonia-triggered PSII destruction is light dependent and occurs already at low photon fluence rates. Experiments with monochromatic light showed that ammonia-promoted PSII photoinhibition is executed by wavebands known to directly destroy the manganese cluster in the PSII oxygen-evolving complex, suggesting that the oxygen-evolving complex may be a direct target for ammonia toxicity. PMID:18322144

  20. Transient Effects of Salt Shock on the Photosynthetic Machinery in Synechocystis sp. PCC 6803

    Institute of Scientific and Technical Information of China (English)

    毛海滨; 阮翔; 李国富; 公衍道; 张秀芳; 赵南明

    2002-01-01

    The transient effects of NaCl on chlorophyll (Chl) fluorescence in Synechocystis sp. PCC 6803 cells were examined. In dark-adapted cells, salt shock induced a transition from state 2 to state 1, and the artificial quinones, phenyl-1,4-benzoquinone (PBQ) and 2,5-dibromo-3-methyl-6-isopropyl-1,4-benzoquinone (DBMIB), quenched the Chl fluorescence markedly after addition of 0.8 mol/L NaCl. In light-adapted cells, the addition of NaCl caused a significant increase in the stationary fluorescence yield, which resulted in a decrease in the quantum yield of photosystem II (PSII). The results indicate that salt shock can induce a change in the affinity between the photosystems and the phycobilisomes (PBS) and can perturb the orientation of the Chl molecules in PSII.

  1. 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.

  2. BMAA inhibits nitrogen fixation in the cyanobacterium Nostoc sp. PCC 7120.

    Science.gov (United States)

    Berntzon, Lotta; Erasmie, Sven; Celepli, Narin; Eriksson, Johan; Rasmussen, Ulla; Bergman, Birgitta

    2013-08-01

    Cyanobacteria produce a range of secondary metabolites, one being the neurotoxic non-protein amino acid β-N-methylamino-L-alanine (BMAA), proposed to be a causative agent of human neurodegeneration. As for most cyanotoxins, the function of BMAA in cyanobacteria is unknown. Here, we examined the effects of BMAA on the physiology of the filamentous nitrogen-fixing cyanobacterium Nostoc sp. PCC 7120. Our data show that exogenously applied BMAA rapidly inhibits nitrogenase activity (acetylene reduction assay), even at micromolar concentrations, and that the inhibition was considerably more severe than that induced by combined nitrogen sources and most other amino acids. BMAA also caused growth arrest and massive cellular glycogen accumulation, as observed by electron microscopy. With nitrogen fixation being a process highly sensitive to oxygen species we propose that the BMAA effects found here may be related to the production of reactive oxygen species, as reported for other organisms. PMID:23966039

  3. BMAA Inhibits Nitrogen Fixation in the Cyanobacterium Nostoc sp. PCC 7120

    Directory of Open Access Journals (Sweden)

    Birgitta Bergman

    2013-08-01

    Full Text Available Cyanobacteria produce a range of secondary metabolites, one being the neurotoxic non-protein amino acid β-N-methylamino-L-alanine (BMAA, proposed to be a causative agent of human neurodegeneration. As for most cyanotoxins, the function of BMAA in cyanobacteria is unknown. Here, we examined the effects of BMAA on the physiology of the filamentous nitrogen-fixing cyanobacterium Nostoc sp. PCC 7120. Our data show that exogenously applied BMAA rapidly inhibits nitrogenase activity (acetylene reduction assay, even at micromolar concentrations, and that the inhibition was considerably more severe than that induced by combined nitrogen sources and most other amino acids. BMAA also caused growth arrest and massive cellular glycogen accumulation, as observed by electron microscopy. With nitrogen fixation being a process highly sensitive to oxygen species we propose that the BMAA effects found here may be related to the production of reactive oxygen species, as reported for other organisms.

  4. Consequences of Decreased Light Harvesting Capability on Photosystem II Function in Synechocystis sp. PCC 6803

    Directory of Open Access Journals (Sweden)

    Aparna Nagarajan

    2014-12-01

    Full Text Available Cyanobacteria use large pigment-protein complexes called phycobilisomes to harvest light energy primarily for photosystem II (PSII. We used a series of mutants with partial to complete reduction of phycobilisomes to examine the effects of antenna truncation on photosystem function in Synechocystis sp. PCC 6803. The antenna mutants CB, CK, and PAL expressed increasing levels of functional PSII centers to compensate for the loss of phycobilisomes, with a concomitant decrease in photosystem I (PSI. This increased PSII titer led to progressively higher oxygen evolution rates on a per chlorophyll basis. The mutants also exhibited impaired S-state transition profiles for oxygen evolution. Additionally, P700+ re-reduction rates were impacted by antenna reduction. Thus, a decrease in antenna size resulted in overall physiological changes in light harvesting and delivery to PSII as well as changes in downstream electron transfer to PSI.

  5. 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

  6. 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.

  7. Coregulated genes link sulfide:quinone oxidoreductase and arsenic metabolism in Synechocystis sp. strain PCC6803.

    Science.gov (United States)

    Nagy, Csaba I; Vass, Imre; Rákhely, Gábor; Vass, István Zoltán; Tóth, András; Duzs, Agnes; Peca, Loredana; Kruk, Jerzy; Kós, Péter B

    2014-10-01

    Although the biogeochemistry of the two environmentally hazardous compounds arsenic and sulfide has been extensively investigated, the biological interference of these two toxic but potentially energy-rich compounds has only been hypothesized and indirectly proven. Here we provide direct evidence for the first time that in the photosynthetic model organism Synechocystis sp. strain PCC6803 the two metabolic pathways are linked by coregulated genes that are involved in arsenic transport, sulfide oxidation, and probably in sulfide-based alternative photosynthesis. Although Synechocystis sp. strain PCC6803 is an obligate photoautotrophic cyanobacterium that grows via oxygenic photosynthesis, we discovered that specific genes are activated in the presence of sulfide or arsenite to exploit the energy potentials of these chemicals. These genes form an operon that we termed suoRSCT, located on a transposable element of type IS4 on the plasmid pSYSM of the cyanobacterium. suoS (sll5036) encodes a light-dependent, type I sulfide:quinone oxidoreductase. The suoR (sll5035) gene downstream of suoS encodes a regulatory protein that belongs to the ArsR-type repressors that are normally involved in arsenic resistance. We found that this repressor has dual specificity, resulting in 200-fold induction of the operon upon either arsenite or sulfide exposure. The suoT gene encodes a transmembrane protein similar to chromate transporters but in fact functioning as an arsenite importer at permissive concentrations. We propose that the proteins encoded by the suoRSCT operon might have played an important role under anaerobic, reducing conditions on primordial Earth and that the operon was acquired by the cyanobacterium via horizontal gene transfer. PMID:25022856

  8. Effects of modified Phycobilin biosynthesis in the Cyanobacterium Synechococcus sp. Strain PCC 7002.

    Science.gov (United States)

    Alvey, Richard M; Biswas, Avijit; Schluchter, Wendy M; Bryant, Donald A

    2011-04-01

    The pathway for phycocyanobilin biosynthesis in Synechococcus sp. strain PCC 7002 comprises two enzymes: heme oxygenase and phycocyanobilin synthase (PcyA). The phycobilin content of cells can be modified by overexpressing genes encoding alternative enzymes for biliverdin reduction. Overexpression of the pebAB and HY2 genes, encoding alternative ferredoxin-dependent biliverdin reductases, caused unique effects due to the overproduction of phycoerythrobilin and phytochromobilin, respectively. Colonies overexpressing pebAB became reddish brown and visually resembled strains that naturally produce phycoerythrin. This was almost exclusively due to the replacement of phycocyanobilin by phycoerythrobilin on the phycocyanin α-subunit. This phenotype was unstable, and such strains rapidly reverted to the wild-type appearance, presumably due to strong selective pressure to inactivate pebAB expression. Overproduction of phytochromobilin, synthesized by the Arabidopsis thaliana HY2 product, was tolerated much better. Cells overexpressing HY2 were only slightly less pigmented and blue-green than the wild type. Although the pcyA gene could not be inactivated in the wild type, pcyA was easily inactivated when cells expressed HY2. These results indicate that phytochromobilin can functionally substitute for phycocyanobilin in Synechococcus sp. strain PCC 7002. Although functional phycobilisomes were assembled in this strain, the overall phycobiliprotein content of cells was lower, the efficiency of energy transfer by these phycobilisomes was lower than for wild-type phycobilisomes, and the absorption cross-section of the cells was reduced relative to that of the wild type because of an increased spectral overlap of the modified phycobiliproteins with chlorophyll a. As a result, the strain producing phycobiliproteins carrying phytochromobilin grew much more slowly at low light intensity. PMID:21296968

  9. Construction and application of the Synechocystis sp. PCC6803-ftnA in microbial contamination control in a coupled cultivation and wastewater treatment.

    Science.gov (United States)

    Zhang, Yalei; Zhang, Chunmin; Zhou, Xuefei; Shen, Zheng; Zhao, Fangchao; Zhao, Jianfu

    2016-08-01

    Inspired by iron fertilization experiments in HNLC (high-nitrate, low-chlorophyll) sea areas, we proposed the use of iron-rich engineered microalgae for microbial contaminant control in iron-free culture media. Based on the genome sequence and natural transformation system of Synechocystis sp. PCC6803, ftnA (encoding ferritin) was selected as our target gene and was cloned into wild-type Synechocystis sp. PCC6803. Tests at the molecular level confirmed the successful construction of the engineered Synechocystis sp. PCC6803-ftnA. After Fe(3+)-EDTA pulsing, the intracellular iron content of Synechocystis sp. PCC6803-ftnA was significantly enhanced, and the algae was used in the microbial contamination control system. In the coupled Synechocystis sp. PCC6803-ftnA production and municipal wastewater (MW, including Scenedesmus obliquus and Bacillus) treatment, Synechocystis sp. PCC6803-ftnA accounted for all of the microbial activity and significantly increased from 70% of the microbial community to 95%. These results revealed that while the stored iron in the Synechocystis sp. PCC6803-ftnA cells was used for growth and reproduction of this microalga in the MW, the growth of other microbes was inhibited because of the iron limitation, and these results provide a new method for microbial contamination control during a coupling process. PMID:27521949

  10. Characterisation of the paralytic shellfish toxin biosynthesis gene clusters in Anabaena circinalis AWQC131C and Aphanizomenon sp. NH-5

    Directory of Open Access Journals (Sweden)

    Neilan Brett A

    2009-03-01

    Full Text Available Abstract Background Saxitoxin and its analogues collectively known as the paralytic shellfish toxins (PSTs are neurotoxic alkaloids and are the cause of the syndrome named paralytic shellfish poisoning. PSTs are produced by a unique biosynthetic pathway, which involves reactions that are rare in microbial metabolic pathways. Nevertheless, distantly related organisms such as dinoflagellates and cyanobacteria appear to produce these toxins using the same pathway. Hypothesised explanations for such an unusual phylogenetic distribution of this shared uncommon metabolic pathway, include a polyphyletic origin, an involvement of symbiotic bacteria, and horizontal gene transfer. Results We describe the identification, annotation and bioinformatic characterisation of the putative paralytic shellfish toxin biosynthesis clusters in an Australian isolate of Anabaena circinalis and an American isolate of Aphanizomenon sp., both members of the Nostocales. These putative PST gene clusters span approximately 28 kb and contain genes coding for the biosynthesis and export of the toxin. A putative insertion/excision site in the Australian Anabaena circinalis AWQC131C was identified, and the organization and evolution of the gene clusters are discussed. A biosynthetic pathway leading to the formation of saxitoxin and its analogues in these organisms is proposed. Conclusion The PST biosynthesis gene cluster presents a mosaic structure, whereby genes have apparently transposed in segments of varying size, resulting in different gene arrangements in all three sxt clusters sequenced so far. The gene cluster organizational structure and sequence similarity seems to reflect the phylogeny of the producer organisms, indicating that the gene clusters have an ancient origin, or that their lateral transfer was also an ancient event. The knowledge we gain from the characterisation of the PST biosynthesis gene clusters, including the identity and sequence of the genes involved

  11. Analysis of carbohydrate storage granules in the diazotrophic cyanobacterium Cyanothece sp. PCC 7822

    Energy Technology Data Exchange (ETDEWEB)

    Welkie, David G. [Purdue Univ., West Lafayette, IN (United States); Sherman, Debra M. [Purdue Univ., West Lafayette, IN (United States); Chrisler, William B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Orr, Galya [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sherman, Louis A. [Purdue Univ., West Lafayette, IN (United States)

    2013-10-19

    The unicellular diazotrophic cyanobacteria of the genus Cyanothece demonstrate oscillations in nitrogenase activity and H2 production when grown under 12h light-12h dark cycles. We established that Cyanothece sp. PCC 7822 allows for the construction of knock-out mutants and our objective was to improve the growth characteristics of this strain and to identify the nature of the intracellular storage granules. We report the physiological and morphological effects of reduction in nitrate and phosphate concentrations in BG-11 media on this strain. We developed a series of BG-11-derived growth media and monitored batch culture growth, nitrogenase activity and nitrogenase-mediated hydrogen production, culture synchronicity, and intracellular storage content. Reduction in NaNO3 and K2HPO4 concentrations from 17.6 and 0.23 mM to 4.41 and 0.06 mM, respectively, improved growth characteristics such as cell size and uniformity, and enhanced the rate of cell division. Cells grown in this low NP BG-11 were less complex, a parameter that related to the composition of the intracellular storage granules. Cells grown in low NP BG-11 had less polyphosphate, fewer polyhydroxybutyrate granules and many smaller granules became evident. Biochemical analysis and transmission electron microscopy using the histocytochemical PATO technique demonstrated that these small granules contained glycogen. The glycogen levels and the number of granules per cell correlated nicely with a 2.3 to 3.3-fold change from the minimum at L0 to the maximum at D0. The differences in granule morphology and enzymes between Cyanothece ATCC 51142 and Cyanothece PCC 7822 provide insights into the formation of large starch-like granules in some cyanobacteria.

  12. Effect of mono- and dichromatic light quality on growth rates and photosynthetic performance of Synechococcus sp. PCC 7002.

    Science.gov (United States)

    Bernstein, Hans C; Konopka, Allan; Melnicki, Matthew R; Hill, Eric A; Kucek, Leo A; Zhang, Shuyi; Shen, Gaozhong; Bryant, Donald A; Beliaev, Alexander S

    2014-01-01

    Synechococcus sp. PCC 7002 was grown to steady state in optically thin turbidostat cultures under conditions for which light quantity and quality was systematically varied by modulating the output of narrow-band LEDs. Cells were provided photons absorbed primarily by chlorophyll (680 nm) or phycocyanin (630 nm) as the organism was subjected to four distinct mono- and dichromatic regimes. During cultivation with dichromatic light, growth rates were generally proportional to the total incident irradiance at values phycobiliprotein content, which increased under severely light-limited growth conditions. Additionally, the ratio of photosystem II to photosystem I increased ~40% over the range of growth rates, although cells grown with 680 nm light only had the highest ratios. These results suggest the presence of effective mechanisms which allow acclimation of Synechococcus sp. PCC 7002 acclimation to different irradiance conditions. PMID:25285095

  13. High-yield production of extracellular type-I cellulose by the cyanobacterium Synechococcus sp. PCC 7002.

    Science.gov (United States)

    Zhao, Chi; Li, Zhongkui; Li, Tao; Zhang, Yingjiao; Bryant, Donald A; Zhao, Jindong

    2015-01-01

    Cellulose synthase, encoded by the cesA gene, is responsible for the synthesis of cellulose in nature. We show that the cell wall of the cyanobacterium Synechococcus sp. PCC 7002 naturally contains cellulose. Cellulose occurs as a possibly laminated layer between the inner and outer membrane, as well as being an important component of the extracellular glycocalyx in this cyanobacterium. Overexpression of six genes, cmc-ccp-cesAB-cesC-cesD-bgl, from Gluconacetobacter xylinus in Synechococcus sp. PCC 7002 resulted in very high-yield production of extracellular type-I cellulose. High-level cellulose production only occurred when the native cesA gene was inactivated and when cells were grown at low salinity. This system provides a method for the production of lignin-free cellulose from sunlight and CO2 for biofuel production and other biotechnological applications. PMID:27462405

  14. Proteolyse in Synechocystis sp. PCC 6803 : Funktion der Methionin-Aminopeptidase 2 und FtsH2-Protease für die Photosystem II-Stressresistenz

    OpenAIRE

    Drath, Miriam

    2008-01-01

    Methionin-Aminopeptidasen sind essentielle und haben physiologisch wichtige Bedeutung in der post- und co-translationellen regulation von Proteinen in Pro- und Eukaryonten. Zu Beginn dieser Dissertation war bekannt, dass die Methionin-Aminopeptidasen (MetAP) 1-3 in Synechocystis sp. PCC 6803 funktionale Aminopeptidasen sind, allerdings waren die physiologischen Funktionen unbekannt. Die Analyse der MetAP2-defizienten Mutante in Synechocystis sp. PCC 6803 stellte ein Ziel dieser Arbeit dar un...

  15. Cloning of a copper resistance gene cluster from the cyanobacterium Synechocystis sp. PCC 6803 by recombineering recovery

    OpenAIRE

    Gittins, John R.

    2015-01-01

    A copper resistance gene cluster (6 genes, ?8.2?kb) was isolated from the cyanobacterium Synechocystis sp. PCC 6803 by recombineering recovery (RR). Following integration of a narrow-host-range plasmid vector adjacent to the target region in the Synechocystis genome (pSYSX), DNA was isolated from transformed cells and the plasmid plus flanking sequence circularized by recombineering to precisely clone the gene cluster. Complementation of a copper-sensitive Escherichia coli mutant demonstrated...

  16. A single vector-based strategy for marker-less gene replacement in Synechocystis sp. PCC 6803

    OpenAIRE

    Viola, Stefania; Rühle, Thilo; Leister, Dario

    2014-01-01

    Background The cyanobacterium Synechocystis sp. PCC 6803 is widely used for research on photosynthesis and circadian rhythms, and also finds application in sustainable biotechnologies. Synechocystis is naturally transformable and undergoes homologous recombination, which enables the development of a variety of tools for genetic and genomic manipulations. To generate multiple gene deletions and/or replacements, marker-less manipulation methods based on counter-selection are generally employed....

  17. 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.

  18. Identification of a Low Molecular Weight Protein Tyrosine Phosphatase and Its Potential Physiological Substrates in Synechocystis sp. PCC 6803

    OpenAIRE

    Mukhopadhyay, Archana

    2006-01-01

    The predicted protein product of open reading frame slr0328 from Synechocystis sp. PCC 6803, SynPTP, possesses significant amino acid sequence similarity with known low molecular weight protein tyrosine phosphatases (PTPs). To determine the gross functional properties of this hypothetical protein, open reading frame slr0328 was cloned, and its predicted protein product was expressed in E. coli. The recombinant protein, SynPTP, was purified by metal ion column chromatography. The catalytic act...

  19. 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: EE - Microbiology, Virology Impact factor: 6.841, year: 2014

  20. Oxygen-responsive genetic circuits constructed in Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Immethun, Cheryl M; Ng, Kenneth M; DeLorenzo, Drew M; Waldron-Feinstein, Ben; Lee, Ying-Chiang; Moon, Tae Seok

    2016-02-01

    As photoautotrophic prokaryotes, cyanobacteria are promising platforms for producing value-added bioproducts. However, few regulatory genetic parts and devices (e.g., inducible promoters and regulatory circuits) have been developed for these potential hosts. Furthermore, the devices that have been created respond only to a single input. To address these issues, we developed an inducible genetic circuit that generates heterologous proteins in response to oxygen, an environmental signal. To test its performance and utility in Synechocystis sp. PCC 6803, a model cyanobacterial strain, we connected this circuit to either heterologous nifHDK genes, which encode oxygen-sensitive nitrogenase's structural proteins, or a fluorescent protein gene. The circuit was transcriptionally activated to generate nifHDK transcripts or fluorescent output only in low oxygen conditions. We expanded the oxygen-responsive circuit into a more complex circuit by building a two-input AND gate, which allows Synechocystis to specifically control expression of the fluorescent reporter in response to two signals, low oxygen and high anhydrotetracycline. To our knowledge, the AND gate is the first complex logic circuit built in a cyanobacterial strain. This work expands the synthetic biology tools available for complex gene expression in cyanobacteria, increasing their potential as biotechnology platforms. Biotechnol. Bioeng. 2016;113: 433-442. © 2015 Wiley Periodicals, Inc. PMID:26264210

  1. Characterization of Chlamydomonas reinhardtii phosphatidylglycerophosphate synthase in Synechocystis sp. PCC 6803

    Directory of Open Access Journals (Sweden)

    Chun-Hsien eHung

    2015-08-01

    Full Text Available Phosphatidylglycerol (PG is an indispensable phospholipid class with photosynthetic function in plants and cyanobacteria. However, its biosynthesis in eukaryotic green microalgae is poorly studied. Here, we report the isolation and characterization of two homologs (CrPGP1 and CrPGP2 of phosphatidylglycerophosphate synthase (PGPS, the rate-limiting enzyme in PG biosynthesis, in Chlamydomonas reinhardtii. Heterologous complementation of Synechocystis sp. PCC 6803 pgsA mutant by CrPGP1 and CrPGP2 rescued the PG-dependent growth phenotype, but the PG level and its fatty acid composition were not fully rescued in the complemented strains. As well, oxygen evolution activity was not fully recovered, although electron transport activity of photosystem II was restored to the wild-type level. Gene expression study of CrPGP1 and CrPGP2 in nutrient-starved C. reinhardtii showed differential response to phosphorus and nitrogen deficiency. Taken together, these results highlight the distinct and overlapping function of PGPS in cyanobacteria and eukaryotic algae.

  2. Monitoring Photosynthesis in Individual Cells of Synechocystis sp. PCC 6803 on a Picosecond Timescale

    Science.gov (United States)

    Krumova, S.B.; Laptenok, S.P.; Borst, J.W.; Ughy, B.; Gombos, Z.; Ajlani, G.; van Amerongen, H.

    2010-01-01

    Picosecond fluorescence kinetics of wild-type (WT) and mutant cells of Synechocystis sp. PCC 6803, were studied at the ensemble level with a streak-camera and at the cell level using fluorescence-lifetime-imaging microscopy (FLIM). The FLIM measurements are in good agreement with the ensemble measurements, but they (can) unveil variations between and within cells. The BE mutant cells, devoid of photosystem II (PSII) and of the light-harvesting phycobilisomes, allowed the study of photosystem I (PSI) in vivo for the first time, and the observed 6-ps equilibration process and 25-ps trapping process are the same as found previously for isolated PSI. No major differences are detected between different cells. The PAL mutant cells, devoid of phycobilisomes, show four lifetimes: ∼20 ps (PSI and PSII), ∼80 ps, ∼440 ps, and 2.8 ns (all due to PSII), but not all cells are identical and variations in the kinetics are traced back to differences in the PSI/PSII ratio. Finally, FLIM measurements on WT cells reveal that in some cells or parts of cells, phycobilisomes are disconnected from PSI/PSII. It is argued that the FLIM setup used can become instrumental in unraveling photosynthetic regulation mechanisms in the future. PMID:20858447

  3. Near infrared fluorescent biliproteins generated from bacteriophytochrome AphB of Nostoc sp. PCC 7120.

    Science.gov (United States)

    Yuan, Che; Li, Hui-Zhen; Tang, Kun; Gärtner, Wolfgang; Scheer, Hugo; Zhou, Ming; Zhao, Kai-Hong

    2016-04-13

    The genome of the cyanobacterium Nostoc sp. PCC 7120 encodes a large number of putative bacteriophytochrome and cyanobacteriochrome photoreceptors that, due to their long-wavelength absorption and fluorescence emission, might serve as fluorescent tags in intracellular investigations. We show that the PAS-GAF domain of the bacteriophytochrome, AphB, binds biliverdin covalently and exhibits, besides its reversible photochemistry, a moderate fluorescence in the near infrared (NIR) spectral region. It was selected for further increasing the brightness while retaining the NIR fluorescence. In the first step, amino acids assumed to improve fluorescence were selectively mutated. The resulting variants were then subjected to several rounds of random mutagenesis and screened for enhanced fluorescence in the NIR. The brightness of optimized PAS-GAF variants increased more than threefold compared to that of wt AphB(1-321), with only insignificant spectral shifts (Amax around 695 nm, and Fmax around 720 nm). In general, the brightness increases with decreasing wavelengths, which allows for a selection of the fluorophore depending on the optical properties of the tissue. A spectral heterogeneity was observed when residue His260, located in close proximity to the chromophore, was mutated to Tyr, emphasizing the strong effects of the environment on the electronic properties of the bound biliverdin chromophore. PMID:27004456

  4. 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)

  5. The Transcriptional Landscape of the Photosynthetic Model Cyanobacterium Synechocystis sp. PCC6803.

    Science.gov (United States)

    Hernández-Prieto, Miguel A; Semeniuk, Trudi Ann; Giner-Lamia, Joaquín; Futschik, Matthias E

    2016-01-01

    Cyanobacteria exhibit a great capacity to adapt to different environmental conditions through changes in gene expression. Although this plasticity has been extensively studied in the model cyanobacterium Synechocystis sp. PCC 6803, a detailed analysis of the coordinated transcriptional adaption across varying conditions is lacking. Here, we report a meta-analysis of 756 individual microarray measurements conducted in 37 independent studies-the most comprehensive study of the Synechocystis transcriptome to date. Using stringent statistical evaluation, we characterized the coordinated adaptation of Synechocystis' gene expression on systems level. Evaluation of the data revealed that the photosynthetic apparatus is subjected to greater changes in expression than other cellular components. Nevertheless, network analyses indicated a significant degree of transcriptional coordination of photosynthesis and various metabolic processes, and revealed the tight co-regulation of components of photosystems I, II and phycobilisomes. Detailed inspection of the integrated data led to the discovery a variety of regulatory patterns and novel putative photosynthetic genes. Intriguingly, global clustering analyses suggested contrasting transcriptional response of metabolic and regulatory genes stress to conditions. The integrated Synechocystis transcriptome can be accessed and interactively analyzed via the CyanoEXpress website (http://cyanoexpress.sysbiolab.eu). PMID:26923200

  6. Metabolic engineering of light-driven cytochrome P450 dependent pathways into Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Wlodarczyk, Artur; Gnanasekaran, Thiyagarajan; Nielsen, Agnieszka Zygadlo; Zulu, Nodumo Nokolunga; Mellor, Silas Busck; Luckner, Manja; Thøfner, Jens Frederik Bang; Olsen, Carl Erik; Mottawie, Mohammed Saddik; Burow, Meike; Pribil, Mathias; Feussner, Ivo; Møller, Birger Lindberg; Jensen, Poul Erik

    2016-01-01

    Solar energy provides the energy input for the biosynthesis of primary and secondary metabolites in plants and other photosynthetic organisms. Some secondary metabolites are high value compounds, and typically their biosynthesis requires the involvement of cytochromes P450s. In this proof of concept work, we demonstrate that the cyanobacterium Synechocystis sp. PCC 6803 is an eminent heterologous host for expression of metabolically engineered cytochrome P450-dependent pathways exemplified by the dhurrin pathway from Sorghum bicolor comprising two membrane bound cytochromes P450s (CYP79A1 and CYP71E1) and a soluble glycosyltransferase (UGT85B1). We show that it is possible to express multiple genes incorporated into a bacterial-like operon by using a self-replicating expression vector in cyanobacteria. We demonstrate that eukaryotic P450s that typically reside in the endoplasmic reticulum membranes can be inserted in the prokaryotic membranes without affecting thylakoid membrane integrity. Photosystem I and ferredoxin replaces the native P450 oxidoreductase enzyme as an efficient electron donor for the P450s both in vitro and in vivo. The engineered strains produced up to 66mg/L of p-hydroxyphenylacetaldoxime and 5mg/L of dhurrin in lab-scale cultures after 3 days of cultivation and 3mg/L of dhurrin in V-shaped photobioreactors under greenhouse conditions after 9 days cultivation. All the metabolites were found to be excreted to the growth media facilitating product isolation. PMID:26548317

  7. Studies on Hemolysis of Hemolysin Produced by Synechocystis sp.PCC 6803

    Institute of Scientific and Technical Information of China (English)

    BI Shuai; WANG Wei; ZHAO Yuanyuan; RU Shaoguo; LIU Yunzhang

    2011-01-01

    Hemolysin produced by various bacteria,may destroy erythrocyte membranes via a pore-forming mechanism,a detergent action,or a lipase activity.Previous to this experiment,the mode of action used by cyanobacterial hemolysin had not been reported.To characterize the action mode of hemolysin produced by the wild-type strain of Synechocystis sp.PCC6803,hemolysis of erythrocytes originating from human,mouse,sheep,rabbit and goldfish was studied.The erythrocytes of mouse,sheep and rabbit were sensitive,while those of human and fish were resistant,to this hemolysin.Using rabbit erythrocytes,it was shown that hemolysis occurred in two steps:a binding step within the first 10min of treatment and a lyric step after 30 min.Both binding and lysis were highly temperature-dependent.Effects of erythrocyte density on hemolysis suggest that the hemolysin might target erythrocytes via a multiple-hit mechanism.In the osmotic protection experiment,all tested osmotic protectants,with molecular diameters ranging from 0.9-5.66 nm,failed to effectively inhibit hemolysis.Scanning electron micrographs showed that the hemolysin caused protuberances or echinocytes in rabbit erythrocytes,and then disrupted and ruptured the erythrocytes.Characteristics of hemolysis showed distinct differences from other pore-forming mechanisms,suggesting that this hemolysin might act through a detergent-like or lipase mechanism,rather than a pore-forming mechanism.

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

    Directory of Open Access Journals (Sweden)

    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.

  9. Flux balance analysis of cyanobacterial metabolism: the metabolic network of Synechocystis sp. PCC 6803.

    Directory of Open Access Journals (Sweden)

    Henning Knoop

    Full Text Available Cyanobacteria are versatile unicellular phototrophic microorganisms that are highly abundant in many environments. Owing to their capability to utilize solar energy and atmospheric carbon dioxide for growth, cyanobacteria are increasingly recognized as a prolific resource for the synthesis of valuable chemicals and various biofuels. To fully harness the metabolic capabilities of cyanobacteria necessitates an in-depth understanding of the metabolic interconversions taking place during phototrophic growth, as provided by genome-scale reconstructions of microbial organisms. Here we present an extended reconstruction and analysis of the metabolic network of the unicellular cyanobacterium Synechocystis sp. PCC 6803. Building upon several recent reconstructions of cyanobacterial metabolism, unclear reaction steps are experimentally validated and the functional consequences of unknown or dissenting pathway topologies are discussed. The updated model integrates novel results with respect to the cyanobacterial TCA cycle, an alleged glyoxylate shunt, and the role of photorespiration in cellular growth. Going beyond conventional flux-balance analysis, we extend the computational analysis to diurnal light/dark cycles of cyanobacterial metabolism.

  10. Interplay between gold nanoparticle biosynthesis and metabolic activity of cyanobacterium Synechocystis sp. PCC 6803

    International Nuclear Information System (INIS)

    Many microorganisms have long been known to be able to synthesize nanoparticles either in extracellular media or inside cells but the biochemical mechanisms involved in biomineralization are still poorly understood. In this paper we report the intracellular synthesis of gold nanoparticles (GNPs) by the cyanobacterium Synechocystis sp. PCC 6803 exposed to an aqueous solution of chloroauric acid. We assess the interplay between the biomineralization process and the metabolic activities (i.e. photosynthesis and respiration) of cyanobacteria cells by correlating the GNP synthesis yield with the amount of respiratory and photosynthetic oxygen exchange. The biogenic GNPs are compared in terms of their internalization and biological effects to GNPs synthesized by a standard citrate reduction procedure (cGNPs). The TEM analysis, in conjunction with spectroscopic measurements (i.e. surface plasmon resonance, fluorescence quenching and surface-enhanced Raman scattering, SERS), reveals the localization of biogenic GNPs at the level of intracytoplasmic membranes whereas the pre-formed cGNPs are located at the level of external cellular membrane. Our findings have implications for better understanding the process of biomineralization and assessing the potential risks associated with the accumulation of nanomaterials by various biological systems.

  11. 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

    2015-11-01

    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.

  12. 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.

  13. Identification of components associated with thermal acclimation of photosystem II in Synechocystis sp. PCC6803.

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    John G Rowland

    Full Text Available BACKGROUND: Photosystem II (PSII is the most thermally sensitive component of photosynthesis. Thermal acclimation of this complex activity is likely to be critically important to the ability of photosynthetic organisms to tolerate temperature changes in the environment. METHODOLOGY/FINDINGS: We have analysed gene expression using whole-genome microarrays and monitored alterations in physiology during acclimation of PSII to elevated growth temperature in Synechocystis sp. PCC 6803. PSII acclimation is complete within 480 minutes of exposure to elevated temperature and is associated with a highly dynamic transcriptional response. 176 genes were identified and classified into seven distinct response profile groups. Response profiles suggest the existence of an early transient phase and a sustained phase to the acclimation response. The early phase was characterised by induction of general stress response genes, including heat shock proteins, which are likely to influence PSII thermal stability. The sustained phase consisted of acclimation-specific alterations that are involved in other cellular processes. Sustained responses included genes involved in phycobillisome structure and modification, photosynthesis, respiration, lipid metabolism and motility. Approximately 60% of genes with sustained altered expression levels have no known function. The potential role of differentially expressed genes in thermotolerance and acclimation is discussed. We have characterised the acclimation physiology of selected gene 'knockouts' to elucidate possible gene function in the response. CONCLUSIONS/SIGNIFICANCE: All mutants show lower PSII rates under normal growth conditions. Basal PSII thermotolerance was affected by mutations in clpB1, cpcC2, hspA, htpG and slr1674. Final PSII thermotolerance was affected by mutations in cpcC2, hik34, hspA and hypA1, suggesting that these gene products play roles in long-term thermal acclimation of PSII.

  14. Interplay between flavodiiron proteins and photorespiration in Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Allahverdiyeva, Yagut; Ermakova, Maria; Eisenhut, Marion; Zhang, Pengpeng; Richaud, Pierre; Hagemann, Martin; Cournac, Laurent; Aro, Eva-Mari

    2011-07-01

    Flavodiiron (Flv) proteins are involved in detoxification of O(2) and NO in anaerobic bacteria and archaea. Cyanobacterial Flv proteins, on the contrary, function in oxygenic environment and possess an extra NAD(P)H:flavin oxidoreductase module. Synechocystis sp. PCC 6803 has four genes (sll1521, sll0219, sll0550, and sll0217) encoding Flv proteins (Flv1, Flv2, Flv3, and Flv4). Previous in vitro studies with recombinant Flv3 protein from Synechocystis provided evidence that it functions as a NAD(P)H:oxygen oxidoreductase, and subsequent in vivo studies with Synechocystis confirmed the role of Flv1 and Flv3 proteins in the Mehler reaction (photoreduction of O(2) to H(2)O). Interestingly, homologous proteins to Flv1 and Flv3 can be found also in green algae, mosses, and Selaginella. Here, we addressed the function of Flv1 and Flv3 in Synechocystis using the Δflv1, Δflv3, and Δflv1/Δflv3 mutants and applying inorganic carbon (C(i))-deprivation conditions. We propose that only the Flv1/Flv3 heterodimer form is functional in the Mehler reaction in vivo. (18)O(2) labeling was used to discriminate between O(2) evolution in photosynthetic water splitting and O(2) consumption. In wild type, ∼20% of electrons originated from water was targeted to O(2) under air level CO(2) conditions but increased up to 60% in severe limitation of C(i). Gas exchange experiments with Δflv1, Δflv3, and Δflv1/Δflv3 mutants demonstrated that a considerable amount of electrons in these mutants is directed to photorespiration under C(i) deprivation. This assumption is in line with increased transcript abundance of photorespiratory genes and accumulation of photorespiratory intermediates in the WT and to a higher extent in mutant cells under C(i) deprivation. PMID:21602273

  15. 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. PMID:27208274

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

    Directory of Open Access Journals (Sweden)

    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.

  17. Lauric acid production in a glycogen-less Synechococcus sp. PCC 7002 mutant

    Directory of Open Access Journals (Sweden)

    Victoria H. Work

    2015-04-01

    Full Text Available The cyanobacterium Synechococcus sp. PCC 7002 was genetically engineered to synthesize biofuel compatible medium-chain fatty acids during photoautotrophic growth. Expression of a heterologous lauroyl-acyl carrier protein (C12:0-ACP thioesterase with concurrent deletion of the endogenous putative acyl-ACP synthetase led to secretion of transesterifiable C12:0 fatty acid in CO2-supplemented batch cultures. When grown at steady state over a range of light intensities in an LED turbidostat photobioreactor, the C12-secreting mutant exhibited a modest reduction in growth rate and increased O2 evolution relative to the wildtype. Inhibition of i glycogen synthesis by deletion of the glgC-encoded ADP-glucose pyrophosphorylase (AGPase, and ii protein synthesis by nitrogen deprivation were investigated as potential mechanisms for metabolite redistribution to increase fatty acid synthesis. Deletion of AGPase led to a ten-fold decrease in reducing carbohydrates and secretion of organic acids during nitrogen deprivation consistent with an energy spilling phenotype. When the carbohydrate-deficient background (∆glgC was modified for C12 secretion, no increase in C12 was achieved during nutrient replete growth, and no C12 was recovered from any strain upon nitrogen deprivation under the conditions used. At steady state, the growth rate of the ∆glgC strain saturated at a lower light intensity than the wildtype, but O2 evolution was not compromised and became increasingly decoupled from growth rate with rising irradiance. Photophysiological properties of the ∆glgC strain suggest energy dissipation from photosystem II and reconfiguration of electron flow at the level of the plastoquinone pool.

  18. Ethylene Regulates the Physiology of the Cyanobacterium Synechocystis sp. PCC 6803 via an Ethylene Receptor.

    Science.gov (United States)

    Lacey, Randy F; Binder, Brad M

    2016-08-01

    Ethylene is a plant hormone that plays a crucial role in the growth and development of plants. The ethylene receptors in plants are well studied, and it is generally assumed that they are found only in plants. In a search of sequenced genomes, we found that many bacterial species contain putative ethylene receptors. Plants acquired many proteins from cyanobacteria as a result of the endosymbiotic event that led to chloroplasts. We provide data that the cyanobacterium Synechocystis (Synechocystis sp. PCC 6803) has a functional receptor for ethylene, Synechocystis Ethylene Response1 (SynEtr1). We first show that SynEtr1 directly binds ethylene. Second, we demonstrate that application of ethylene to Synechocystis cells or disruption of the SynEtr1 gene affects several processes, including phototaxis, type IV pilus biosynthesis, photosystem II levels, biofilm formation, and spontaneous cell sedimentation. Our data suggest a model where SynEtr1 inhibits downstream signaling and ethylene inhibits SynEtr1. This is similar to the inverse-agonist model of ethylene receptor signaling proposed for plants and suggests a conservation of structure and function that possibly originated over 1 billion years ago. Prior research showed that SynEtr1 also contains a light-responsive phytochrome-like domain. Thus, SynEtr1 is a bifunctional receptor that mediates responses to both light and ethylene. To our knowledge, this is the first demonstration of a functional ethylene receptor in a nonplant species and suggests that that the perception of ethylene is more widespread than previously thought. PMID:27246094

  19. Effect of mono- and dichromatic light quality on growth rates and photosynthetic performance of Synechococcus sp. PCC 7002

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, Hans C.; Konopka, Allan; Melnicki, Matthew R.; Hill, Eric A.; Kucek, Leo A.; Zhang, Shuyi; Shen, Gaozhong; Bryant, Donald A.; Beliaev, Alex S.

    2014-09-19

    Synechococcus sp. PCC 7002 was grown to steady state in optically thin turbidostat cultures under conditions for which light quantity and quality was systematically varied by modulating the output of narrow-band LEDs. Cells were provided photons absorbed primarily by chlorophyll (680 nm) or phycocyanin (630 nm) as the organism was subjected to four distinct mono- and dichromatic regimes. During cultivation with dichromatic light, growth rates displayed by Synechococcus sp. PCC 7002 were generally proportional to the total incident irradiance at values < 275 µmol photons m-2 s-1 and were not affected by the ratio of 630:680 nm wavelengths. Notably, under monochromatic light conditions, cultures exhibited similar growth rates only when they were irradiated with 630 nm light; cultures irradiated with only 680 nm light grew at rates that were 60 – 70% of those under other light quality regimes at equivalent irradiances. The functionality of photosystem II and associated processes such as maximum rate of photosynthetic electron transport, rate of cyclic electron flow, and rate of dark respiration generally increased as a function of growth rate. Nonetheless, some of the photophysiological parameters measured here displayed distinct patterns with respect to growth rate of cultures adapted to a single wavelength including phycobiliprotein content, which increased under severely light-limited growth conditions. Additionally, the ratio of photosystem II to photosystem I increased approximately 40% over the range of growth rates, although cells grown with 680 nm light only had the highest ratios. These results suggest the presence of effective mechanisms which allow acclimation of Synechococcus sp. PCC 7002 acclimation to different irradiance conditions.

  20. Engineering limonene and bisabolene production in wild type and a glycogen-deficient mutant of Synechococcus sp. PCC 7002

    Energy Technology Data Exchange (ETDEWEB)

    Davies, Fiona K.; Work, Victoria H.; Beliaev, Alex S.; Posewitz, Matthew C.

    2014-06-19

    The plant terpenoids limonene (C10H16) and α-bisabolene (C15H24) are hydrocarbon precursors to a range of industrially-relevant chemicals. High-titer microbial synthesis of limonene and α- bisabolene could pave the way for advances in in vivo engineering of tailor-made hydrocarbons, and production at commercial scale. We have engineered the fast-growing unicellular euryhaline cyanobacterium Synechococcus sp. PCC 7002 to produce yields of 4 mg L-1 limonene and 0.6 mg L-1 α-bisabolene through heterologous expression of the Mentha spicata L-limonene synthase or the Abies grandis (E)-α-bisabolene synthase genes, respectively. Titers were significantly higher when a dodecane overlay was applied during culturing, suggesting either that dodecane traps large quantities of volatile limonene and α-bisabolene that would otherwise be lost to evaporation, and/or that continuous product removal in dodecane alleviates product feedback inhibition to promote higher rates of synthesis. We also investigate limonene and bisabolene production in the ΔglgC genetic background, where carbon partitioning is redirected at the expense of glycogen biosynthesis. The Synechococcus sp. PCC 7002 ΔglgC mutant excreted a suite of overflow metabolites (α-ketoisocaproate, pyruvate, α-ketoglutarate, succinate and acetate) during nitrogen deprivation, and also at the onset of stationary growth in nutrient-replete media. None of the excreted metabolites, however, appeared to be effectively utilized for terpenoid metabolism. Interestingly, we observed a 1.6 to 2.5-fold increase in the extracellular concentration of most excreted organic acids when the ΔglgC mutant was conferred with the ability to produce limonene. Overall, Synechococcus sp. PCC 7002 provides a highly promising platform for terpenoid biosynthetic and metabolic engineering efforts.

  1. Engineering limonene and bisabolene production in wild type and a glycogen-deficient mutant of Synechococcus sp. PCC 7002

    Directory of Open Access Journals (Sweden)

    Fiona K Davies

    2014-06-01

    Full Text Available The plant terpenoids limonene (C10H16 and α-bisabolene (C15H24 are hydrocarbon precursors to a range of industrially-relevant chemicals. High-titer microbial synthesis of limonene and α-bisabolene could pave the way for advances in in vivo engineering of tailor-made hydrocarbons, and production at commercial scale. We have engineered the fast-growing unicellular euryhaline cyanobacterium Synechococcus sp. PCC 7002 to produce yields of 4 mg L-1 limonene and 0.6 mg L-1 α-bisabolene through heterologous expression of the Mentha spicata L-limonene synthase or the Abies grandis (E-α-bisabolene synthase genes, respectively. Titers were significantly higher when a dodecane overlay was applied during culturing, suggesting either that dodecane traps large quantities of volatile limonene and α-bisabolene that would otherwise be lost to evaporation, and/or that continuous product removal in dodecane alleviates product feedback inhibition to promote higher rates of synthesis. We also investigate limonene and bisabolene production in the ΔglgC genetic background, where carbon partitioning is redirected at the expense of glycogen biosynthesis. The Synechococcus sp. PCC 7002 ΔglgC mutant excreted a suite of overflow metabolites (α-ketoisocaproate, pyruvate, α-ketoglutarate, succinate and acetate during nitrogen deprivation, and also at the onset of stationary growth in nutrient-replete media. None of the excreted metabolites, however, appeared to be effectively utilized for terpenoid metabolism. Interestingly, we observed a 1.6 to 2.5-fold increase in the extracellular concentration of most excreted organic acids when the ΔglgC mutant was conferred with the ability to produce limonene. Overall, Synechococcus sp. PCC 7002 provides a highly promising platform for terpenoid biosynthetic and metabolic engineering efforts.

  2. Effect of mono- and dichromatic light quality on growth rates and photosynthetic performance of Synechococcus sp. PCC 7002

    Directory of Open Access Journals (Sweden)

    Hans C Bernstein

    2014-09-01

    Full Text Available Synechococcus sp. PCC 7002 was grown to steady state in optically thin turbidostat cultures under conditions for which light quantity and quality was systematically varied by modulating the output of narrow-band LEDs. Cells were provided photons absorbed primarily by chlorophyll (680 nm or phycocyanin (630 nm as the organism was subjected to four distinct mono- and dichromatic regimes. During cultivation with dichromatic light, growth rates displayed by Synechococcus sp. PCC 7002 were generally proportional to the total incident irradiance at values < 275 µmol photons m-2 s-1 and were not affected by the ratio of 630:680 nm wavelengths. Notably, under monochromatic light conditions, cultures exhibited similar growth rates only when they were irradiated with 630 nm light; cultures irradiated with only 680 nm light grew at rates that were 60 – 70% of those under other light quality regimes at equivalent irradiances. The functionality of photosystem II and associated processes such as maximum rate of photosynthetic electron transport, rate of cyclic electron flow, and rate of dark respiration generally increased as a function of growth rate. Nonetheless, some of the photophysiological parameters measured here displayed distinct patterns with respect to growth rate of cultures adapted to a single wavelength including phycobiliprotein content, which increased under severely light-limited growth conditions. Additionally, the ratio of photosystem II to photosystem I increased approximately 40% over the range of growth rates, although cells grown with 680 nm light only had the highest ratios. These results suggest the presence of effective mechanisms which allow acclimation of Synechococcus sp. PCC 7002 acclimation to different irradiance conditions.

  3. Global Transcriptional Response of the Alkalitolerant Cyanobacterium Synechocystis sp. Strain PCC 6803 to pH 10.

    OpenAIRE

    Summerfield, Tina C.; Sherman, Louis A.

    2008-01-01

    Many cyanobacterial strains are able to grow at a pH range from neutral to pH 10 or 11. Such alkaline conditions favor cyanobacterial growth (e.g., bloom formation), and cyanobacteria must have developed strategies to adjust to changes in CO2 concentration and ion availability. Synechocystis sp. strain PCC 6803 exhibits similar photoautotrophic growth characteristics at pH 10 and pH 7.5, and we examined global gene expression following transfer from pH 7.5 to pH 10 to determine cellular adapt...

  4. 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

  5. Characterization of a sodium-regulated glutaminase from cyanobacterium Synechocystis sp. PCC 6803

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Glutaminase is widely distributed among microorganisms and mammals with important functions. Lit-tle is known regarding the biochemical properties and functions of the deamidating enzyme glutami-nase in cyanobacteria. In this study a putative glutaminase encoded by gene slr2079 in Synechocystis sp. PCC 6803 was investigated. The slr2079 was expressed as histidine-tagged fusion protein in Es-cherichia coli. The purified protein possessed glutaminase activity, validating the functional assign-ment of the genomic annotation. The apparent Km value of the recombinant protein for glutamine was 26.6 ± 0.9 mmol/L, which was comparable to that for some of other microbial glutaminases. Analysis of the purified protein revealed a two-fold increase in catalytic activity in the presence of 1 mol/L Na+. Moreover, the Km value was decreased to 12.2 ± 1.9 mmol/L in the presence of Na+. These data demon-strate that the recombinant protein Slr2079 is a glutaminase which is regulated by Na+ through in-creasing its affinity for substrate glutamine. The slr2079 gene was successfully disrupted in Synecho-cystis by targeted mutagenesis and the △slr2079 mutant strain was analyzed. No differences in cell growth and oxygen evolution rate were observed between △slr2079 and the wild type under standard growth conditions, demonstrating slr2079 is not essential in Synechocystis. Under high salt stress condition, however, △slr2079 cells grew 1.25-fold faster than wild-type cells. Moreover, the photosyn-thetic oxygen evolution rate of △slr2079 cells was higher than that of the wild-type. To further charac-terize this phenotype, a number of salt stress-related genes were analyzed by semi-quantitative RT-PCR. Expression of gdhB and prc was enhanced and expression of desD and guaA was repressed in △slr2079 compared to the wild type. In addition, expression of two key enzymes of ammonium assimi-lation in cyanobacteria, glutamine synthetase (GS) and glutamate synthase (GOGAT) was examined

  6. Gene expression patterns of sulfur starvation in Synechocystis sp. PCC 6803

    Directory of Open Access Journals (Sweden)

    Pendse Ninad D

    2008-07-01

    Full Text Available Abstract Background The unicellular cyanobacterium Synechocystis sp. PCC 6803 is a model microbe for studying biochemistry, genetics and molecular biology of photobiological processes. Importance of this bacterium in basic and applied research calls for a systematic, genome-wide description of its transcriptional regulatory capacity. Characteristic transcriptional responses to changes in the growth environment are expected to provide a scaffold for describing the Synechocystis transcriptional regulatory network as well as efficient means for functional annotation of genes in the genome. Results We designed, validated and used Synechocystis genome-wide oligonucleotide (70-mer microarray (representing 96.7% of all chromosomal ORFs annotated at the time of the beginning of this project to study transcriptional activity of the cyanobacterial genome in response to sulfur (S starvation. The microarray data were verified by quantitative RT-PCR. We made five main observations: 1 Transcriptional changes upon sulfate starvation were relatively moderate, but significant and consistent with growth kinetics; 2 S acquisition genes encoding for a high-affinity sulfate transporter were significantly induced, while decreased transcription of genes for phycobilisome, photosystems I and II, cytochrome b6/f, and ATP synthase indicated reduced light-harvesting and photosynthetic activity; 3 S starvation elicited transcriptional responses associated with general growth arrest and stress; 4 A large number of genes regulated by S availability encode hypothetical proteins or proteins of unknown function; 5 Hydrogenase structural and maturation accessory genes were not identified as differentially expressed, even though increased hydrogen evolution was observed. Conclusion The expression profiles recorded by using this oligonucleotide-based microarray platform revealed that during transition from the condition of plentiful S to S starvation, Synechocystis undergoes

  7. Heterologous expression and characterization of glycogen branching enzyme from Synechocystis sp. PCC6803.

    Science.gov (United States)

    Lee, Byung-Hoo; Yoo, Young-Hee; Ryu, Je-Hoon; Kim, Tae-Jip; Yoo, Sang-Ho

    2008-08-01

    A gene (sll0158) putatively encoding a glycogen branching enzyme (GBE, E.C. 2.4.1.18) was cloned from Synechocystis sp. PCC6803, and the recombinant protein expressed and characterized. The PCR-amplified putative GBE gene was ligated into a pET-21a plasmid vector harboring a T7 promoter, and the recombinant DNA transformed into a host cell, E. coli BL21(DE3). The IPTG-induced enzymes were then extracted and purified using Ni-NTA affinity chromatography. The putative GBE gene was found to be composed of 2,310 nucleotides and encoded 770 amino acids, corresponding to approx. 90.7 kDa, as confirmed by SDS-PAGE and MALDI-TOF-MS analyses. The optimal conditions for GBE activity were investigated by measuring the absorbance change in iodine affinity, and shown to be pH 8.0 and 30 degrees in a 50 mM glycine-NaOH buffer. The action pattern of the GBE on amylose, an alpha-(1,4)-linked linear glucan, was analyzed using high-performance anion-exchange chromatography (HPAEC) after isoamylolysis. As a result, the GBE displayed alpha-glucosyl transferring activity by cleaving the alpha-(1,4)-linkages and transferring the cleaved maltoglycosyl moiety to form new alpha-(1,6)- branch linkages. A time-course study of the GBE reaction was carried out with biosynthetic amylose (BSAM; Mp approximately = 8,000), and the changes in the branch-chain length distribution were evaluated. When increasing the reaction time up to 48 h, the weight- and number-average DP (DPw and DPn) decreased from 19.6 to 8.7 and from 17.6 to 7.8, respectively. The molecular size (Mp, peak Mw approximately = 2.45-2.75 x 10(5)) of the GBE-reacted product from BSAM reached the size of amylose (AM) in botanical starch, yet the product was highly soluble and stable in water, unlike AM molecules. Thus, GBE-generated products can provide new food and non-food applications, owing to their unique physical properties. PMID:18756098

  8. Regulation of Expression of Nitrate and Dinitrogen Assimilation by Anabaena Species

    OpenAIRE

    Meeks, John C.; Wycoff, Keith L.; Chapman, John S.; Enderlin, Carol S.

    1983-01-01

    Anabaena sp. strain 7120 appeared more responsive to nitrogen control than A. cylindrica. Growth in the presence of nitrate strongly repressed the differentiation of heterocysts and fixation of dinitrogen in Anabaena sp. strain 7120, but only weakly in A. cylindrica. Nitrate assimilation by ammonium-grown cultures was strongly repressed in Anabaena sp. strain 7120, but less so in A. cylindrica. The repressive effect of nitrate on dinitrogen assimilation in Anabaena sp. strain 7120, compared t...

  9. 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.

  10. Characterization of a Synechococcus sp. strain PCC 7002 spontaneous mutant strain defective in accumulation of photosystem II core chlorophyll-protein complexes.

    OpenAIRE

    Webb, R.; Punnett, T

    1989-01-01

    Two photosystem II-associated chlorophyll-protein complexes of Synechococcus sp. strain PCC 7002 were identified. Their polypeptide compositions were similar to those of chlorophyll-containing antenna complexes of other cyanobacteria. Strain GT8B did not possess the complex responsible for 695-nm fluorescence and was unable to grow photoautotrophically; hence, this complex is necessary for photosystem II function in vivo.

  11. Utilization of Anabaena sp. in CO{sub 2} removal processes. Modelling of biomass, exopolysaccharides productivities and CO{sub 2} fixation rate

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Fernandez, J.F.; Gonzalez-Lopez, C.V.; Acien Fernandez, F.G.; Fernandez Sevilla, J.M.; Molina Grima, E. [Almeria Univ. (Spain). Dept. of Chemical Engineering

    2012-05-15

    This paper focuses on modelling the growth rate and exopolysaccharides production of Anabaena sp. ATCC 33047, to be used in carbon dioxide removal and biofuels production. For this, the influence of dilution rate, irradiance and aeration rate on the biomass and exopolysaccharides productivity, as well as on the CO{sub 2} fixation rate, have been studied. The productivity of the cultures was maximum at the highest irradiance and dilution rate assayed, resulting to 0.5 g{sub bio} l{sup -1} day{sup -1} and 0.2 g{sub eps} l{sup -1} day{sup -1}, and the CO{sub 2} fixation rate measured was 1.0 gCO{sub 2} l{sup -1} day{sup -1}. The results showed that although Anabaena sp. was partially photo-inhibited at irradiances higher than 1,300 {mu}E m-2 s{sup -1}, its growth rate increases hyperbolically with the average irradiance inside the culture, and so does the specific exopolysaccharides production rate. The latter, on the other hand, decreases under high external irradiances, indicating that the exopolysaccharides metabolism hindered by photo-damage. Mathematical models that consider these phenomena have been proposed. Regarding aeration, the yield of the cultures decreased at rates over 0.5 v/v/min or when shear rates were higher than 60 s{sup -1}, demonstrating the existence of thus existence of stress damage by aeration. The behaviour of the cultures has been verified outdoors in a pilot-scale airlift tubular photobioreactor. From this study it is concluded that Anabaena sp. is highly recommended to transform CO{sub 2} into valuable products as has been proved capable of metabolizing carbon dioxide at rates of 1.2 gCO{sub 2} l{sup -1} day{sup -1} outdoors. The adequacy of the proposed equations is demonstrated, resulting to a useful tool in the design and operation of photobioreactors using this strain. (orig.)

  12. Cloning of a copper resistance gene cluster from the cyanobacterium Synechocystis sp. PCC 6803 by recombineering recovery.

    Science.gov (United States)

    Gittins, John R

    2015-07-01

    A copper resistance gene cluster (6 genes, ∼8.2 kb) was isolated from the cyanobacterium Synechocystis sp. PCC 6803 by recombineering recovery (RR). Following integration of a narrow-host-range plasmid vector adjacent to the target region in the Synechocystis genome (pSYSX), DNA was isolated from transformed cells and the plasmid plus flanking sequence circularized by recombineering to precisely clone the gene cluster. Complementation of a copper-sensitive Escherichia coli mutant demonstrated the functionality of the pcopM gene encoding a copper-binding protein. RR provides a novel alternative method for cloning large DNA fragments from species that can be transformed by homologous recombination. PMID:25980606

  13. 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.

  14. Complementation of a phycocyanin-bilin lyase from Synechocystis sp. PCC 6803 with a nucleomorph-encoded open reading frame from the cryptophyte Guillardia theta

    Directory of Open Access Journals (Sweden)

    Nyalwidhe Julius

    2008-05-01

    Full Text Available Abstract Background Cryptophytes are highly compartmentalized organisms, expressing a secondary minimized eukaryotic genome in the nucleomorph and its surrounding remnant cytoplasm, in addition to the cell nucleus, the mitochondrion and the plastid. Because the members of the nucleomorph-encoded proteome may contribute to essential cellular pathways, elucidating nucleomorph-encoded functions is of utmost interest. Unfortunately, cryptophytes are inaccessible for genetic transformations thus far. Therefore the functions of nucleomorph-encoded proteins must be elucidated indirectly by application of methods in genetically accessible organisms. Results Orf222, one of the uncharacterized nucleomorph-specific open reading frames of the cryptophyte Guillardia theta, shows homology to slr1649 of Synechocystis sp. PCC 6803. Recently a further homolog from Synechococcus sp. PCC 7002 was characterized to encode a phycocyanin-β155-bilin lyase. Here we show by insertion mutagenesis that the Synechocystis sp. PCC 6803 slr1649-encoded protein also acts as a bilin lyase, and additionally contributes to linker attachment and/or stability of phycobilisomes. Finally, our results indicate that the phycocyanin-β155-bilin lyase of Synechocystis sp. PCC 6803 can be complemented in vivo by the nucleomorph-encoded open reading frame orf222. Conclusion Our data show that the loss of phycocyanin-lyase function causes pleiotropic effects in Synechocystis sp. PCC 6803 and indicate that after separating from a common ancestor protein, the phycoerythrin lyase from Guillardia theta has retained its capacity to couple a bilin group to other phycobiliproteins. This is a further, unexpected example of the universality of phycobiliprotein lyases.

  15. Regulation of Development and Nitrogen Fixation in Anabaena

    Energy Technology Data Exchange (ETDEWEB)

    James W Golden

    2004-08-05

    The nitrogen-fixing filamentous cyanobacterium Anabaena sp. strain PCC 7120 is being used as a simple model of microbial development and pattern formation in a multicellular prokaryotic organism. Anabaena reduces atmospheric nitrogen to ammonia in highly specialized, terminally differentiated cells called heterocysts. Anabaena is an important model system because of the multicellular growth pattern, the suspected antiquity of heterocyst development, and the contribution of fixed nitrogen to the environment. We are especially interested in understanding the molecular signaling pathways and genetic regulation that control heterocyst development. In the presence of an external source of reduced nitrogen, the differentiation of heterocysts is inhibited. When Anabaena is grown on dinitrogen, a one-dimensional developmental pattern of single heterocysts separated by approximately ten vegetative cells is established to form a multicellular organism composed of two interdependent cell types. The goal of this project is to understand the signaling and regulatory pathways that commit a vegetative cell to terminally differentiate into a nitrogen-fixing heterocyst. Several genes identified by us and by others were chosen as entry points into the regulatory network. Our research, which was initially focused on transcriptional regulation by group 2 sigma factors, was expanded to include group 3 sigma factors and their regulators after the complete Anabaena genome sequence became available. Surprisingly, no individual sigma factor is essential for heterocyst development. We have used the isolation of extragenic suppressors to study genetic interactions between key regulatory genes such as patS, hetR, and hetC in signaling and developmental pathways. We identified a hetR R223W mutation as a bypass suppressor of patS overexpression. Strains containing the hetR R223W allele fail to respond to pattern formation signals and overexpression of this allele results in a lethal phenotype

  16. Identification and characterization of a carboxysomal γ-carbonic anhydrase from the cyanobacterium Nostoc sp. PCC 7120.

    Science.gov (United States)

    de Araujo, Charlotte; Arefeen, Dewan; Tadesse, Yohannes; Long, Benedict M; Price, G Dean; Rowlett, Roger S; Kimber, Matthew S; Espie, George S

    2014-09-01

    Carboxysomes are proteinaceous microcompartments that encapsulate carbonic anhydrase (CA) and ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco); carboxysomes, therefore, catalyze reversible HCO3 (-) dehydration and the subsequent fixation of CO2. The N- and C-terminal domains of the β-carboxysome scaffold protein CcmM participate in a network of protein-protein interactions that are essential for carboxysome biogenesis, organization, and function. The N-terminal domain of CcmM in the thermophile Thermosynechococcus elongatus BP-1 is also a catalytically active, redox regulated γ-CA. To experimentally determine if CcmM from a mesophilic cyanobacterium is active, we cloned, expressed and purified recombinant, full-length CcmM from Nostoc sp. PCC 7120 as well as the N-terminal 209 amino acid γ-CA-like domain. Both recombinant proteins displayed ethoxyzolamide-sensitive CA activity in mass spectrometric assays, as did the carboxysome-enriched TP fraction. NstCcmM209 was characterized as a moderately active and efficient γ-CA with a k cat of 2.0 × 10(4) s(-1) and k cat/K m of 4.1 × 10(6) M(-1) s(-1) at 25 °C and pH 8, a pH optimum between 8 and 9.5 and a temperature optimum spanning 25-35 °C. NstCcmM209 also catalyzed the hydrolysis of the CO2 analog carbonyl sulfide. Circular dichroism and intrinsic tryptophan fluorescence analysis demonstrated that NstCcmM209 was progressively and irreversibly denatured above 50 °C. NstCcmM209 activity was inhibited by the reducing agent tris(hydroxymethyl)phosphine, an effect that was fully reversed by a molar excess of diamide, a thiol oxidizing agent, consistent with oxidative activation being a universal regulatory mechanism of CcmM orthologs. Immunogold electron microscopy and Western blot analysis of TP pellets indicated that Rubisco and CcmM co-localize and are concentrated in Nostoc sp. PCC 7120 carboxysomes. PMID:24907906

  17. Integrated Analysis of Engineered Carbon Limitation in a Quadruple CO2/HCO3- Uptake Mutant of Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Orf, Isabel; Klähn, Stephan; Schwarz, Doreen; Frank, Marcus; Hess, Wolfgang R; Hagemann, Martin; Kopka, Joachim

    2015-11-01

    Cyanobacteria have efficient carbon concentration mechanisms and suppress photorespiration in response to inorganic carbon (Ci) limitation. We studied intracellular Ci limitation in the slow-growing CO2/HCO3 (-)-uptake mutant ΔndhD3 (for NADH dehydrogenase subunit D3)/ndhD4 (for NADH dehydrogenase subunit D4)/cmpA (for bicarbonate transport system substrate-binding protein A)/sbtA (for sodium-dependent bicarbonate transporter A): Δ4 mutant of Synechocystis sp. PCC 6803. When cultivated under high-CO2 conditions, ∆4 phenocopies wild-type metabolic and transcriptomic acclimation responses after the shift from high to low CO2 supply. The ∆4 phenocopy reveals multiple compensation mechanisms and differs from the preacclimation of the transcriptional Ci regulator mutant ∆ndhR (for ndhF3 operon transcriptional regulator). Contrary to the carboxysomeless ∆ccmM (for carbon dioxide concentrating mechanism protein M) mutant, the metabolic photorespiratory burst triggered by shifting to low CO2 is not enhanced in ∆4. However, levels of the photorespiratory intermediates 2-phosphoglycolate and glycine are increased under high CO2. The number of carboxysomes is increased in ∆4 under high-CO2 conditions and appears to be the major contributing factor for the avoidance of photorespiration under intracellular Ci limitation. The ∆4 phenocopy is associated with the deregulation of Ci control, an overreduced cellular state, and limited photooxidative stress. Our data suggest multiple layers of Ci regulation, including inversely regulated modules of antisense RNAs and cognate target messenger RNAs and specific trans-acting small RNAs, such as the posttranscriptional PHOTOSYNTHESIS REGULATORY RNA1 (PsrR1), which shows increased expression in ∆4 and is involved in repressing many photosynthesis genes at the posttranscriptional level. In conclusion, our insights extend the knowledge on the range of compensatory responses of Synechocystis sp. PCC 6803 to intracellular Ci

  18. A Cyanobacterium Synechocystis sp. PCC 6803 Glutaredoxin Gene (slr1562 Protects Escherichia coli against Abiotic Stresses

    Directory of Open Access Journals (Sweden)

    Ahmed Gaber

    2012-01-01

    Full Text Available Problem statement: Glutaredoxins (GRXs are ubiquitous small heat stable glutathione-dependent oxidoreductase enzymes that play a crucial role in plant development and response to oxidative stress. Approach: Cyanobacterium Synechocystis strain PCC 6803 contains two genes (slr1562 and ssr2061 encoding glutaredoxins. In the present investigation the slr1562 gene (grxC was isolated and characterized. Results: The results revealed that the amino acid sequence deduced from GrxC protein share high identity with those of GRXs from other organisms and contain the consensus GRX family domain with a CPFC active site. Northern blotting analysis revealed that the expression of slr1562 gene could be induced by oxidative and salt stresses. Moreover, the protein GrxC was successfully overexpressed as a soluble fraction in Escherichia coli JM109. The over-expression of GrxC in Escherichia coli cells significantly increased resistance of cells to oxidative, drought and salt stresses. Conclusion/Recommendations: These results suggest that the slr1562 gene could play an important role in regulating abiotic tolerance against oxidative, drought and salt stresses in different organisms.

  19. 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

  20. CRISPR-Cas Systems in the Cyanobacterium Synechocystis sp. PCC6803 Exhibit Distinct Processing Pathways Involving at Least Two Cas6 and a Cmr2 Protein

    OpenAIRE

    Scholz, Ingeborg; Lange, Sita J.; Hein, Stephanie; Wolfgang R Hess; Backofen, Rolf

    2013-01-01

    The CRISPR-Cas (Clustered Regularly Interspaced Short Palindrome Repeats – CRISPR associated proteins) system provides adaptive immunity in archaea and bacteria. A hallmark of CRISPR-Cas is the involvement of short crRNAs that guide associated proteins in the destruction of invading DNA or RNA. We present three fundamentally distinct processing pathways in the cyanobacterium Synechocystis sp. PCC6803 for a subtype I-D (CRISPR1), and two type III systems (CRISPR2 and CRISPR3), which are locate...

  1. A low molecular weight protein tyrosine phosphatase from Synechocystis sp. strain PCC 6803: enzymatic characterization and identification of its potential substrates

    OpenAIRE

    Mukhopadhyay, Archana; Kennelly, Peter J.

    2011-01-01

    The predicted protein product of open reading frame slr0328 from Synechocystis sp. PCC 6803, SynPTP, possesses significant amino acid sequence similarity with known low molecular weight protein tyrosine phosphatases (PTPs). To determine the functional properties of this hypothetical protein, open reading frame slr0328 was expressed in Escherichia coli. The purified recombinant protein, SynPTP, displayed its catalytic phosphatase activity towards several tyrosine, but not serine, phosphorylate...

  2. 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.

  3. Recombinant PsbF from Synechococcus sp. PCC 7002 forms β:βhomodimeric cytochrome b559

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    All organisms with oxygenic photosynthesis contain two photosystems: photosystemⅠ(PSⅠ) and photosystem-Ⅱ-(PSⅡ). The minimal photosystem-Ⅱ-particles which are photochemically active contain three subunits: D1, D2 and cytochrome b559 (Cyt b559). The function of Cyt b559 remains unclear. We have successfully overexpressed the psbF gene, encoding the - subunit of Cyt b559, from a marine cyanobacterium Synechococcus sp. PCC 7002 as a fusion gene and obtained a redox-active form of Cyt b559. When the N-terminal GST protein of the fusion gene product was removed with thrombin, the PsbF protein was still redox-active, suggesting that the recombinant PsbF can form dimer in Escherichia coli. The absorption spectra of either the oxidized form or the reduced form of both GST fusion protein and the purified PsbF dimer and the difference spectra between the two forms are the same as that of the Cyt b559 isolated from the higher plants. Redox titration analysis of recombinant PsbF showed that the mid-point redox potential of the recombinant Cyt b559 was approximately 50 mV, which is close to the low potential of Cyt b559. The results are helpful to the understanding of localization and function of Cyt b559 on thylakoid membranes.

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

    Directory of Open Access Journals (Sweden)

    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.

  5. Zeaxanthin and Echinenone Protect the Repair of Photosystem II from Inhibition by Singlet Oxygen in Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Kusama, Yuri; Inoue, Shuhei; Jimbo, Haruhiko; Takaichi, Shinichi; Sonoike, Kintake; Hihara, Yukako; Nishiyama, Yoshitaka

    2015-05-01

    Carotenoids are important components of antioxidative systems in photosynthetic organisms. We investigated the roles of zeaxanthin and echinenone in the protection of PSII from photoinhibition in Synechocystis sp. PCC 6803, using mutants of the cyanobacterium that lack these carotenoids. The activity of PSII in mutant cells deficient in either zeaxanthin or echinenone was more sensitive to strong light than the activity in wild-type cells, and the activity in mutant cells deficient in both carotenoids was hypersensitive to strong light, indicating that the absence of these carotenoids increased the extent of photoinhibition. Nonetheless, the rate of photodamage to PSII, as measured in the presence of chloramphenicol, which blocks the repair of PSII, was unaffected by the absence of either carotenoid, suggesting that these carotenoids might act by protecting the repair of PSII. Knockout of the gene for the so-called orange carotenoid protein (OCP), in which the 3'-hydroxyechinenone cofactor, a derivative of echinenone, is responsible for the thermal dissipation of excitation energy, increased the extent of photoinhibition but did not affect photodamage, suggesting that thermal dissipation also protects the repair of PSII. In mutant cells lacking OCP, as well as those lacking zeaxanthin and echinenone, the production of singlet oxygen was stimulated and the synthesis de novo of various proteins, including the D1 protein, was markedly suppressed under strong light. These observations suggest that the carotenoids and thermal dissipation might protect the repair of photodamaged PSII by depressing the levels of singlet oxygen that inhibits protein synthesis. PMID:25663484

  6. FtsH is involved in the early stages of repair of photosystem II in Synechocystis sp PCC 6803.

    Science.gov (United States)

    Silva, Paulo; Thompson, Elinor; Bailey, Shaun; Kruse, Olaf; Mullineaux, Conrad W; Robinson, Colin; Mann, Nicholas H; Nixon, Peter J

    2003-09-01

    When plants, algae, and cyanobacteria are exposed to excessive light, especially in combination with other environmental stress conditions such as extreme temperatures, their photosynthetic performance declines. A major cause of this photoinhibition is the light-induced irreversible photodamage to the photosystem II (PSII) complex responsible for photosynthetic oxygen evolution. A repair cycle operates to selectively replace a damaged D1 subunit within PSII with a newly synthesized copy followed by the light-driven reactivation of the complex. Net loss of PSII activity occurs (photoinhibition) when the rate of damage exceeds the rate of repair. The identities of the chaperones and proteases involved in the replacement of D1 in vivo remain uncertain. Here, we show that one of the four members of the FtsH family of proteases (cyanobase designation slr0228) found in the cyanobacterium Synechocystis sp PCC 6803 is important for the repair of PSII and is vital for preventing chronic photoinhibition. Therefore, the ftsH gene family is not functionally redundant with respect to the repair of PSII in this organism. Our data also indicate that FtsH binds directly to PSII, is involved in the early steps of D1 degradation, and is not restricted to the removal of D1 fragments. These results, together with the recent analysis of ftsH mutants of Arabidopsis, highlight the critical role played by FtsH proteases in the removal of damaged D1 from the membrane and the maintenance of PSII activity in vivo. PMID:12953117

  7. 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

    2014-01-01

    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. PMID:24983765

  8. Genes for phycocyanin subunits in Synechocystis sp. strain PCC 6701 and assembly mutant UV16.

    OpenAIRE

    Anderson, L K; Grossman, A R

    1990-01-01

    The cyanobacterial phycobilisome is a large protein complex located on the photosynthetic membrane. It harvests light energy and transfers it to chlorophyll for use in photosynthesis. Phycobilisome assembly mutants in the unicellular cyanobacterium Synechocystis sp. strain 6701 have been characterized. One such mutant, UV16, contains a defect in the assembly of the biliprotein phycocyanin. We report the cloning and sequencing of the phycocyanin genes from wild-type Synechocystis strain 6701 a...

  9. Regulation of Development and Nitrogen Fixation in Anabaena

    Energy Technology Data Exchange (ETDEWEB)

    James W. Golden

    2008-10-17

    The regulation of development and cellular differentiation is important for all multicellular organisms. The nitrogen-fixing filamentous cyanobacterium Anabaena (also Nostoc) sp. PCC 7120 (hereafter Anabaena) provides a model of multicellular microbial development and pattern formation. Anabaena reduces N2 to ammonia in specialized terminally differentiated cells called heterocysts. A one-dimensional developmental pattern of single heterocysts regularly spaced along filaments of photosynthetic vegetative cells is established to form a multicellular organism composed of these two interdependent cell types. This multicellular growth pattern, the distinct phylogeny of cyanobacteria, and the suspected antiquity of heterocyst development make this an important model system. Our long-term goal is to understand the regulatory network required for heterocyst development and nitrogen fixation. This project is focused on two key aspects of heterocyst regulation: one, the mechanism by which HetR controls the initiation of differentiation, and two, the cis and trans acting factors required for expression of the nitrogen-fixation (nif) genes. HetR is thought to be a central regulator of heterocyst development but the partners and mechanisms involved in this regulation are unknown. Our recent results indicate that PatS and other signals that regulate heterocyst pattern cannot interact, directly or indirectly, with a R223W mutant of HetR. We plan to use biochemical and genetic approaches to identify proteins that interact with the HetR protein, which will help reveal the mechanisms underlying its regulation of development. Our second goal is to determine how the nif genes are expressed. It is important to understand the mechanisms controlling nif genes since they represent the culmination of the differentiation process and the essence of heterocyst function. The Anabaena genome lacks the genes required for expression of nif genes present in other organisms such as rpoN (sigma 54

  10. 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; Forchhammer, Karl

    2015-07-01

    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

  11. Consequences of ccmR deletion on respiration, fermentation and H2 metabolism in cyanobacterium Synechococcus sp. PCC 7002.

    Science.gov (United States)

    Krishnan, Anagha; Zhang, Shuyi; Liu, Yang; Tadmori, Kinan A; Bryant, Donald A; Dismukes, Charles G

    2016-07-01

    CcmR, a LysR-type transcriptional regulator, represses the genes encoding components of the high-affinity carbon concentration mechanism in cyanobacteria. Unexpectedly, deletion of the ccmR gene was found to alter the expression of the terminal oxidase and fermentative genes, especially the hydrogenase operon in the cyanobacterium Synechococcus sp. PCC 7002. Consistent with the transcriptomic data, the deletion strain exhibits flux increases (30-50%) in both aerobic O2 respiration and anaerobic H2 evolution. To understand how CcmR influences anaerobic metabolism, the kinetics of autofermentation were investigated following photoautotrophic growth. The autofermentative H2 yield increased by 50% in the CcmR deletion strain compared to the wild-type strain, and increased to 160% (within 20 h) upon continuous removal of H2 from the medium ("milking") to suppress H2 uptake. Consistent with this greater reductant flux to H2 , the mutant excreted less lactate during autofermentation (NAD(P)H consuming pathway). To enhance the rate of NADH production during anaerobic metabolism, the ccmR mutant was engineered to introduce GAPDH overexpression (more NADH production) and LDH deletion (less NADH consumption). The triple mutant (ccmR deletion + GAPDH overexpression + LDH deletion) showed 6-8-fold greater H2 yield than the WT strain, achieving conversion rates of 17 nmol 10(8)  cells(-1)  h(-1) and yield of 0.87 H2 per glucose equivalent (8.9% theoretical maximum). Simultaneous monitoring of the intracellular NAD(P)H concentration and H2 production rate by these mutants reveals an inverse correspondence between these variables indicating hydrogenase-dependent H2 production as a major sink for consuming NAD(P)H in preference to excretion of reduced carbon as lactate during fermentation. Biotechnol. Bioeng. 2016;113: 1448-1459. © 2015 Wiley Periodicals, Inc. PMID:26704377

  12. Functional studies of the gene slr2049 from Synechocystis sp. PCC6803 and its site-directed mutation.

    Science.gov (United States)

    Liu, Bingjun; Chen, Sili; Zhang, Lei

    2015-06-01

    Phycobiliprotein is a homologous family of light-harvesting chromoproteins existing in cyanobacteria, red algae and cryptophytes. Phycobiliprotein is made up of phycobilin and its corresponding apophycobiliprotein, and they are covalently linked by the thioether bond with the bilin lyase. Using the software BLAST, we have found gene slr2049 in Synechocystis sp. PCC6803 homologous to the biliprotein lyase gene cpeS. This paper investigates the protein expressed by gene slr2049 to find the enzymatic activity characteristics. We cloned slr2049 and its related genes cpcB, ho1, and pcyA which are linked with the synthesis of phycocyanin. Special amino acid mutagenesis was performed on slr2049 to construct eight mutants slr2049 (H21S), slr2049 (L23S), slr2049 (A24S), slr2049 (F25S), slr2049 (W72L), slr2049 (G84S), slr2049 (R107S) and slr2049 (Y124S). These mutants were ligated with vectors pEDFDuet-1 and pET-23a to construct pCDF-cpcB-slr2049 wild-type, pCDF-cpcB-slr2049 mutants and pET-ho1-pcyA, for the purpose of protein expression and analysis. The results showed that the wild-type and mutants slr2049 (H21S), slr2049 (L23S), slr2049 (F25S), slr2049 (W72L), slr2049 (G84S), and slr2049 (Y124S) can catalyze CpcB to couple on PCB correctly and the products have unique spectral characteristics. However mutants slr2049 (A24S) and slr2049 (R107S) have no spectral characteristics. Thus, it is suggested that alanine at position 24 and arginine at position 107 are the active sites. PMID:25791490

  13. Inactivation of nitrate reductase alters metabolic branching of carbohydrate fermentation in the cyanobacterium Synechococcus sp. strain PCC 7002.

    Science.gov (United States)

    Qian, Xiao; Kumaraswamy, G Kenchappa; Zhang, Shuyi; Gates, Colin; Ananyev, Gennady M; Bryant, Donald A; Dismukes, G Charles

    2016-05-01

    To produce cellular energy, cyanobacteria reduce nitrate as the preferred pathway over proton reduction (H2 evolution) by catabolizing glycogen under dark anaerobic conditions. This competition lowers H2 production by consuming a large fraction of the reducing equivalents (NADPH and NADH). To eliminate this competition, we constructed a knockout mutant of nitrate reductase, encoded by narB, in Synechococcus sp. PCC 7002. As expected, ΔnarB was able to take up intracellular nitrate but was unable to reduce it to nitrite or ammonia, and was unable to grow photoautotrophically on nitrate. During photoautotrophic growth on urea, ΔnarB significantly redirects biomass accumulation into glycogen at the expense of protein accumulation. During subsequent dark fermentation, metabolite concentrations--both the adenylate cellular energy charge (∼ATP) and the redox poise (NAD(P)H/NAD(P))--were independent of nitrate availability in ΔnarB, in contrast to the wild type (WT) control. The ΔnarB strain diverted more reducing equivalents from glycogen catabolism into reduced products, mainly H2 and d-lactate, by 6-fold (2.8% yield) and 2-fold (82.3% yield), respectively, than WT. Continuous removal of H2 from the fermentation medium (milking) further boosted net H2 production by 7-fold in ΔnarB, at the expense of less excreted lactate, resulting in a 49-fold combined increase in the net H2 evolution rate during 2 days of fermentation compared to the WT. The absence of nitrate reductase eliminated the inductive effect of nitrate addition on rerouting carbohydrate catabolism from glycolysis to the oxidative pentose phosphate (OPP) pathway, indicating that intracellular redox poise and not nitrate itself acts as the control switch for carbon flux branching between pathways. PMID:26479976

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

    Science.gov (United States)

    Selão, Tiago T; Zhang, Lifang; Knoppová, Jana; Komenda, Josef; Norling, Birgitta

    2016-01-01

    Thylakoid biogenesis is an intricate process requiring accurate and timely assembly of proteins, pigments and other cofactors into functional, photosynthetically competent membranes. PSII assembly is studied in particular as its core protein, D1, is very susceptible to photodamage and has a high turnover rate, particularly in high light. PSII assembly is a modular process, with assembly steps proceeding in a specific order. Using aqueous two-phase partitioning to separate plasma membranes (PM) and thylakoid membranes (TM), we studied the subcellular localization of the early assembly steps for PSII biogenesis in a Synechocystis sp. PCC6803 cyanobacterium strain lacking the CP47 antenna. This strain accumulates the early D1-D2 assembly complex which was localized in TM along with associated PSII assembly factors. We also followed insertion and processing of the D1 precursor (pD1) by radioactive pulse-chase labeling. D1 is inserted into the membrane with a C-terminal extension which requires cleavage by a specific protease, the C-terminal processing protease (CtpA), to allow subsequent assembly of the oxygen-evolving complex. pD1 insertion as well as its conversion to mature D1 under various light conditions was seen only in the TM. Epitope-tagged CtpA was also localized in the same membrane, providing further support for the thylakoid location of pD1 processing. However, Vipp1 and PratA, two proteins suggested to be part of the so-called 'thylakoid centers', were found to associate with the PM. Together, these results suggest that early PSII assembly steps occur in TM or specific areas derived from them, with interaction with PM needed for efficient PSII and thylakoid biogenesis. PMID:26578692

  15. Contributions of DPOR at Low Light Intensity to Chlorophyll Biosynthesis and Growth in the Synechocystis sp.PCC 6803

    Institute of Scientific and Technical Information of China (English)

    黄卫; 吴庆余; 余久久

    2004-01-01

    The chlL gene encoding one component of light-independent (dark) protochlorophyllide oxido reductase (DPOR) was deleted in cyanobacterium Synechocystis sp. PCC 6803 (S.6803). The resulting chlL mutant lost DPOR activity. No significant differences of chlorophyll (Chi) content and growth rate were observed between the wild and the mutant strains grown at 50 μE · m-2· s-1 light intensity for photomixtrophic and photoautotrophic growth. However, differences were observed at 1 μE · m-2 · s-1 light intensity. For photomixtrophic growth, the mutant Chi content was 50% of the wild content with continuous light and 35.7% of the wild content with a 10 h light/14 h dark cycle. For photoautotriphic growth, the mutant Chi level was 76.3% of the wild content with continuous light and 63.2% with a 10 h light/14 h dark cycle. The results indicate that DPOR contributes to Chi synthesis and increases the growth rate in cyanobacteria phototrophically cultured at 1μE · m-2 ·s-1 light intensity. In contrast, the photosynthetic capacity on a per-cell basis of the mutant is 5% higher than that of the wild strain with continuous light and 27% higher than that of the wild strain with a 10 h light/14 h dark cycle at 1 μE · m-2 · s-1 light intensity for photoautotrophic growth. With the low Chi content, the cyanobacteria have the ability to improve their photosynthetic capacity by decreasing the ratio of PSI to PSII by unknown morphological or physiological means.

  16. Effects of heavy metals (Pb2+ and Cd2+) on the ultrastructure, growth and pigment contents of the unicellular cyanobacterium Synechocystis sp. PCC 6803

    Science.gov (United States)

    Arunakumara, K. K. I. U.; Zhang, Xuecheng

    2009-05-01

    The unicellular cyanobacterium Synechocystis sp. PCC 6803, a model organism known for its unique combination of highly desirable molecular genetic, physiological and morphological characteristics, was employed in the present study. The species was cultured in BG11 liquid medium contained various initial concentrations of Pb2+ and Cd2+ (0, 0.5, 1, 2, 4, 6 and 8 mg/L). The experiment was conducted for six days and the metal induced alterations in the ultrastructure, growth and pigment contents were assessed. Alterations in the ultrastructure of the Synechocystis sp. PCC 6803 cells became evident with the increased (>4 mg/L Pb2+) metal concentration. The photosynthetic apparatus (thylakoid membranes) were found to be the worst affected. Deteriorated or completely destroyed thylakoid membranes have made large empty spaces in the cell interior. In addition, at the highest concentration (8 mg/L Pb2+), the polyphosphate granules became more prominent both in size and number. Despite the initial slight stimulations (0.2, 3.8 and 6.5% respectively at 0.5, 1 and 2 mg/L Pb2+), both metals inhibited the growth in a dose-dependent manner as incubation progressed. Pigment contents (chlorophyll α, β carotene and phycocyanin) were also decreased with increasing metal concentration. Cells exposed to 6 mg/L Pb2+, resulted in 36.56, 37.39 and 29.34% reductions of chlorophyll α, β carotene and phycocyanin respectively over the control. Corresponding reductions for the same Cd2+concentrations were 57.83, 48.94 and 56.90%. Lethal concentration (96 h LC50) values (3.47 mg/L Cd2+ and 12.11 mg/L Pb2+) indicated that Synechocystis sp. PCC 6803 is more vulnerable to Cd2+ than Pb2+.

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

    OpenAIRE

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

    2012-01-01

    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 wit...

  18. Global Transcriptional Response of the Alkali-Tolerant Cyanobacterium Synechocystis sp. Strain PCC 6803 to a pH 10 Environment▿ †

    OpenAIRE

    Summerfield, Tina C.; Sherman, Louis A.

    2008-01-01

    Many cyanobacterial strains are able to grow at a pH range from neutral to pH 10 or 11. Such alkaline conditions favor cyanobacterial growth (e.g., bloom formation), and cyanobacteria must have developed strategies to adjust to changes in CO2 concentration and ion availability. Synechocystis sp. strain PCC 6803 exhibits similar photoautotrophic growth characteristics at pH 10 and pH 7.5, and we examined global gene expression following transfer from pH 7.5 to pH 10 to determine cellular adapt...

  19. Protein (Cyanobacteria): 246786 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available SQVLRELENCLAEHAGDYVRLIGIDPKAKSRVMEKIIQRPGDRPAQFSSSSSGNYSSSSSNSYSQNSVSAGGGGSSDLQSQIQQLVNQGYRISLEHADKRRFKANAWNTGPSFGAANS...TQGSSNPNSYSSQSTEMQLNSEVVQDVRQLLSAGYRIGTEHVDQRRFRINSWQSCAPIESIQE...anabaena sp. PCC 7367 MPSRRAPAPPTPWSPTLTNPQIHESSYIHPSSYVIGDVKIGANVLIAPGTSVRADEGTPFYIGSGTNIQDGVVIHGLEQGRIKGNDGKDYSVWVGENS...SITHKALVHGPCYVGDDCFIGFRSTVFNAKVGDGCIVMMHVLIQDVEIPPGKYVPSGAIITTQQQADRLPNVNKDDVEFAHHVVGINEALRSGYQCAESNVCLADFRTHLQNSY...RHRASAWNTGPSFQGSQASSVVKDLRAFLSEHNGEYVKLIGVDPNAKRRISEVVVQQPNGKSINSNSRNSQPSNNGYSSSS

  20. 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

  1. An alternative methionine aminopeptidase, MAP-A, is required for nitrogen starvation and high-light acclimation in the cyanobacterium Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Drath, Miriam; Baier, Kerstin; Forchhammer, Karl

    2009-05-01

    Methionine aminopeptidases (MetAPs or MAPs, encoded by map genes) are ubiquitous and pivotal enzymes for protein maturation in all living organisms. Whereas most bacteria harbour only one map gene, many cyanobacterial genomes contain two map paralogues, the genome of Synechocystis sp. PCC 6803 even three. The physiological function of multiple map paralogues remains elusive so far. This communication reports for the first time differential MetAP function in a cyanobacterium. In Synechocystis sp. PCC 6803, the universally conserved mapC gene (sll0555) is predominantly expressed in exponentially growing cells and appears to be a housekeeping gene. By contrast, expression of mapA (slr0918) and mapB (slr0786) genes increases during stress conditions. The mapB paralogue is only transiently expressed, whereas the widely distributed mapA gene appears to be the major MetAP during stress conditions. A mapA-deficient Synechocystis mutant shows a subtle impairment of photosystem II properties even under non-stressed conditions. In particular, the binding site for the quinone Q(B) is affected, indicating specific N-terminal methionine processing requirements of photosystem II components. MAP-A-specific processing becomes essential under certain stress conditions, since the mapA-deficient mutant is severely impaired in surviving conditions of prolonged nitrogen starvation and high light exposure. PMID:19359320

  2. 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.

  3. Integrated in silico Analyses of Regulatory and Metabolic Networks of Synechococcus sp. PCC 7002 Reveal Relationships between Gene Centrality and Essentiality

    Directory of Open Access Journals (Sweden)

    Hyun-Seob Song

    2015-03-01

    Full Text Available Cyanobacteria dynamically relay environmental inputs to intracellular adaptations through a coordinated adjustment of photosynthetic efficiency and carbon processing rates. The output of such adaptations is reflected through changes in transcriptional patterns and metabolic flux distributions that ultimately define growth strategy. To address interrelationships between metabolism and regulation, we performed integrative analyses of metabolic and gene co-expression networks in a model cyanobacterium, Synechococcus sp. PCC 7002. Centrality analyses using the gene co-expression network identified a set of key genes, which were defined here as “topologically important.” Parallel in silico gene knock-out simulations, using the genome-scale metabolic network, classified what we termed as “functionally important” genes, deletion of which affected growth or metabolism. A strong positive correlation was observed between topologically and functionally important genes. Functionally important genes exhibited variable levels of topological centrality; however, the majority of topologically central genes were found to be functionally essential for growth. Subsequent functional enrichment analysis revealed that both functionally and topologically important genes in Synechococcus sp. PCC 7002 are predominantly associated with translation and energy metabolism, two cellular processes critical for growth. This research demonstrates how synergistic network-level analyses can be used for reconciliation of metabolic and gene expression data to uncover fundamental biological principles.

  4. Regulation of photosynthesis during heterocyst differentiation in Anabaena sp strain PCC 7120 investigated in vivo at single-cell level by chlorophyll fluorescence kinetic microscopy

    Czech Academy of Sciences Publication Activity Database

    Ferimazová, Naila; Felcmanová, Kristina; Šetlíková, Eva; Küpper, H.; Maldener, I.; Hauska, G.; Šedivá, Barbora; Prášil, Ondřej

    2013-01-01

    Roč. 116, č. 1 (2013), s. 79-91. ISSN 0166-8595 R&D Projects: GA ČR GA206/08/1683; GA MŠk(CZ) ED2.1.00/03.0110 Institutional support: RVO:61388971 Keywords : Acclimation to abiotic stress * Heterocyst differentiation * Nitrogen fixation Subject RIV: EE - Microbiology, Virology Impact factor: 3.185, year: 2013

  5. Gene Inactivation in the Cyanobacterium Synechococcus sp. PCC 7002 and the Green Sulfur Bacterium Chlorobium tepidum Using In Vitro-Made DNA Constructs and Natural Transformation

    DEFF Research Database (Denmark)

    Frigaard, Niels-Ulrik; Sakuragi, Yumiko; Bryant, Donald A

    2004-01-01

    Inactivation of a chromosomal gene is a useful approach to study the function of the gene in question and can be used to produce a desired phenotype in the organism. This chapter describes how to generate such mutants of the cyanobacterium Synechococcus sp. PCC 7002 and the green sulfur bacterium...

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

    Science.gov (United States)

    Zavřel, Tomáš; Knoop, Henning; Steuer, Ralf; Jones, Patrik R; Červený, Jan; Trtílek, Martin

    2016-02-01

    The prediction of the world's future energy consumption and global climate change makes it desirable to identify new technologies to replace or augment fossil fuels by environmentally sustainable alternatives. One appealing sustainable energy concept is harvesting solar energy via photosynthesis coupled to conversion of CO2 into chemical feedstock and fuel. In this work, the production of ethylene, the most widely used petrochemical produced exclusively from fossil fuels, in the model cyanobacterium Synechocystis sp. PCC 6803 is studied. A novel instrumentation setup for quantitative monitoring of ethylene production using a combination of flat-panel photobioreactor coupled to a membrane-inlet mass spectrometer is introduced. Carbon partitioning is estimated using a quantitative model of cyanobacterial metabolism. The results show that ethylene is produced under a wide range of light intensities with an optimum at modest irradiances. The results allow production conditions to be optimized in a highly controlled setup. PMID:26708481

  7. Identification of Specific Variations in a Non-Motile Strain of Cyanobacterium Synechocystis sp. PCC 6803 Originated from ATCC 27184 by Whole Genome Resequencing

    Directory of Open Access Journals (Sweden)

    Qinglong Ding

    2015-10-01

    Full Text Available Cyanobacterium Synechocystis sp. PCC 6803 is a widely used model organism in basic research and biofuel biotechnology application. Here, we report the genomic sequence of chromosome and seven plasmids of a glucose-tolerant, non-motile strain originated from ATCC 27184, GT-G, in use at Guangzhou. Through high-throughput genome re-sequencing and verification by Sanger sequencing, eight novel variants were identified in its chromosome and plasmids. The eight novel variants, especially the five non-silent mutations might have interesting effects on the phenotype of GT-G strains, for example the truncated Sll1895 and Slr0322 protein. These resequencing data provide background information for further research and application based on the GT-G strain and also provide evidence to study the evolution and divergence of Synechocystis 6803 globally.

  8. Modulation of Medium-Chain Fatty Acid Synthesis in Synechococcus sp. PCC 7002 by Replacing FabH with a Chaetoceros Ketoacyl-ACP Synthase

    Science.gov (United States)

    Gu, Huiya; Jinkerson, Robert E.; Davies, Fiona K.; Sisson, Lyle A.; Schneider, Philip E.; Posewitz, Matthew C.

    2016-01-01

    The isolation or engineering of algal cells synthesizing high levels of medium-chain fatty acids (MCFAs) is attractive to mitigate the high clouding point of longer chain fatty acids in algal based biodiesel. To develop a more informed understanding of MCFA synthesis in photosynthetic microorganisms, we isolated several algae from Great Salt Lake and screened this collection for MCFA accumulation to identify strains naturally accumulating high levels of MCFA. A diatom, Chaetoceros sp. GSL56, accumulated particularly high levels of C14 (up to 40%), with the majority of C14 fatty acids allocated in triacylglycerols. Using whole cell transcriptome sequencing and de novo assembly, putative genes encoding fatty acid synthesis enzymes were identified. Enzymes from this Chaetoceros sp. were expressed in the cyanobacterium Synechococcus sp. PCC 7002 to validate gene function and to determine whether eukaryotic enzymes putatively lacking bacterial evolutionary control mechanisms could be used to improve MCFA production in this promising production strain. Replacement of the Synechococcus 7002 native FabH with a Chaetoceros ketoacyl-ACP synthase III increased MCFA synthesis up to fivefold. The level of increase is dependent on promoter strength and culturing conditions. PMID:27303412

  9. Alterations in protein synthesis in the cyanobacterium Synechococcus sp. Strain PCC 6301 in response to Calendula Micrantha extract with the Molluscicidal activity

    International Nuclear Information System (INIS)

    The response to the extract of the egyptian wild herb Calendula Micrantha, with the Molluscicidal activity, was examined in the unicellular no bacterium Synechococcus sp. strain PCC 6301. growth and chlorophyll of the cells were only slightly affected by low plant extract concentrations but were drastically reduced by high concentration. the rate of protein synthesis progressively decreased by increasing extract concentration. the cells preferentially induced the synthesis of a limited number of polypeptides in response to the treatment. Among the induced polypeptides were those with apparent molecular weights of 161 K (161.000), 96.7 K, 93.4 K, 69.9 K, 59 K, 49 K, 45 K, 35 K, 32.4 K, 28 K, 24 K, 21.7 K, 18 K and 16 K based on their mobilities in gel electrophoresis. these initial studies suggest that the plant extract exerted certain stress which stimulated alteration in the pattern of protein synthesis in Synechococcus sp. some of induced polypeptides are similar to that known to occur in other stresses specially heat shock stress. 3 figs

  10. A new cyanobacterial species of Anabaena genus (Nostocales, Cyanobacteria) from Bulgaria

    OpenAIRE

    Kirilov Kirjakov, Ivan; Naneva Velichkova, Katya

    2016-01-01

    Una nueva especie de cianobacteria del género Anabaena (Nostocales, Cyanobacteria) de Bulgaria Se describe una nueva especie del género de Cyanobacterias, Anabaena Bory ex Born. et Flah. (Nostocales) de las montañas Ródope de Bulgaria. Anabaena rhodopensis sp. nova. tiene acinetas con paredes celulares esculpidas. Se dan los datos biométricos para el tamaño de las células vegetativas, heterocistos y acinetos. Abstract: A new species of cyanobacterial genus Anabaena Bo...

  11. Diversity and transcription of proteases involved in the maturation of hydrogenases in Nostoc punctiforme ATCC 29133 and Nostoc sp. strain PCC 7120

    Directory of Open Access Journals (Sweden)

    Lindblad Peter

    2009-03-01

    Full Text Available Abstract Background The last step in the maturation process of the large subunit of [NiFe]-hydrogenases is a proteolytic cleavage of the C-terminal by a hydrogenase specific protease. Contrary to other accessory proteins these hydrogenase proteases are believed to be specific whereby one type of hydrogenases specific protease only cleaves one type of hydrogenase. In cyanobacteria this is achieved by the gene product of either hupW or hoxW, specific for the uptake or the bidirectional hydrogenase respectively. The filamentous cyanobacteria Nostoc punctiforme ATCC 29133 and Nostoc sp strain PCC 7120 may contain a single uptake hydrogenase or both an uptake and a bidirectional hydrogenase respectively. Results In order to examine these proteases in cyanobacteria, transcriptional analyses were performed of hupW in Nostoc punctiforme ATCC 29133 and hupW and hoxW in Nostoc sp. strain PCC 7120. These studies revealed numerous transcriptional start points together with putative binding sites for NtcA (hupW and LexA (hoxW. In order to investigate the diversity and specificity among hydrogeanse specific proteases we constructed a phylogenetic tree which revealed several subgroups that showed a striking resemblance to the subgroups previously described for [NiFe]-hydrogenases. Additionally the proteases specificity was also addressed by amino acid sequence analysis and protein-protein docking experiments with 3D-models derived from bioinformatic studies. These studies revealed a so called "HOXBOX"; an amino acid sequence specific for protease of Hox-type which might be involved in docking with the large subunit of the hydrogenase. Conclusion Our findings suggest that the hydrogenase specific proteases are under similar regulatory control as the hydrogenases they cleave. The result from the phylogenetic study also indicates that the hydrogenase and the protease have co-evolved since ancient time and suggests that at least one major horizontal gene transfer

  12. 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

  13. CRISPR-Cas systems in the cyanobacterium Synechocystis sp. PCC6803 exhibit distinct processing pathways involving at least two Cas6 and a Cmr2 protein.

    Directory of Open Access Journals (Sweden)

    Ingeborg Scholz

    Full Text Available The CRISPR-Cas (Clustered Regularly Interspaced Short Palindrome Repeats--CRISPR associated proteins system provides adaptive immunity in archaea and bacteria. A hallmark of CRISPR-Cas is the involvement of short crRNAs that guide associated proteins in the destruction of invading DNA or RNA. We present three fundamentally distinct processing pathways in the cyanobacterium Synechocystis sp. PCC6803 for a subtype I-D (CRISPR1, and two type III systems (CRISPR2 and CRISPR3, which are located together on the plasmid pSYSA. Using high-throughput transcriptome analyses and assays of transcript accumulation we found all CRISPR loci to be highly expressed, but the individual crRNAs had profoundly varying abundances despite single transcription start sites for each array. In a computational analysis, CRISPR3 spacers with stable secondary structures displayed a greater ratio of degradation products. These structures might interfere with the loading of the crRNAs into RNP complexes, explaining the varying abundancies. The maturation of CRISPR1 and CRISPR2 transcripts depends on at least two different Cas6 proteins. Mutation of gene sll7090, encoding a Cmr2 protein led to the disappearance of all CRISPR3-derived crRNAs, providing in vivo evidence for a function of Cmr2 in the maturation, regulation of expression, Cmr complex formation or stabilization of CRISPR3 transcripts. Finally, we optimized CRISPR repeat structure prediction and the results indicate that the spacer context can influence individual repeat structures.

  14. Resistance, accumulation and transformation of selenium by the cyanobacterium Synechocystis sp. PCC 6803 after exposure to inorganic Se{sup VI} or Se{sup IV}

    Energy Technology Data Exchange (ETDEWEB)

    Gouget, B.; Avoscan, L.; Collins, R.; Carriere, M. [Lab. Pierre Suee, CEA-CNRS UMR 9956, CEA/Saclay, Gif-sur-Yvette (France); Sarret, G. [Environmental Geochemistry Group, LGIT, Univ. of Grenoble and CNRS, Grenoble (France)

    2005-07-01

    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.)

  15. Organization of a large gene cluster encoding ribosomal proteins in the cyanobacterium Synechococcus sp. strain PCC 6301: comparison of gene clusters among cyanobacteria, eubacteria and chloroplast genomes.

    Science.gov (United States)

    Sugita, M; Sugishita, H; Fujishiro, T; Tsuboi, M; Sugita, C; Endo, T; Sugiura, M

    1997-08-11

    The structure of a large gene cluster containing 22 ribosomal protein (r-protein) genes of the cyanobacterium Synechococcus sp. strain PCC6301 is presented. Based on DNA and protein sequence analyses, genes encoding r-proteins L3, L4, L23, L2, S19, L22, S3, L16, L29, S17, L14, L24, L5, S8, L6, L18, S5, L15, L36, S13, S11, L17, SecY, adenylate kinase (AK) and the alpha subunit of RNA polymerase were identified. The gene order is similar to that of the E. coli S10, spc and alpha operons. Unlike the corresponding E. coli operons, the genes for r-proteins S4, S10, S14 and L30 are not present in this cluster. The organization of Synechococcus r-protein genes also resembles that of chloroplast (cp) r-protein genes of red and brown algal species. This strongly supports the endosymbiotic theory that the cp genome evolved from an ancient photosynthetic bacterium. PMID:9300823

  16. 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. PMID:23148271

  17. NdhV subunit regulates the activity of type-1 NAD(P)H dehydrogenase under high light conditions in cyanobacterium Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Chen, Xin; He, Zhihui; Xu, Min; Peng, Lianwei; Mi, Hualing

    2016-01-01

    The cyanobacterial NAD(P)H dehydrogenase (NDH-1) complexes play crucial roles in variety of bioenergetic reactions. However, the regulative mechanism of NDH-1 under stressed conditions is still unclear. In this study, we detected that the NDH-1 activity is partially impaired, but the accumulation of NDH-1 complexes was little affected in the NdhV deleted mutant (ΔndhV) at low light in cyanobacterium Synechocystis sp. PCC 6803. ΔndhV grew normally at low light but slowly at high light under inorganic carbon limitation conditions (low pH or low CO2), meanwhile the activity of CO2 uptake was evidently lowered than wild type even at pH 8.0. The accumulation of NdhV in thylakoids strictly relies on the presence of the hydrophilic subcomplex of NDH-1. Furthermore, NdhV was co-located with hydrophilic subunits of NDH-1 loosely associated with the NDH-1L, NDH-1MS' and NDH-1M complexes. The level of the NdhV was significantly increased at high light and deletion of NdhV suppressed the up-regulation of NDH-1 activity, causing the lowered the photosynthetic oxygen evolution at pH 6.5 and high light. These data indicate that NdhV is an intrinsic subunit of hydrophilic subcomplex of NDH-1, required for efficient operation of cyclic electron transport around photosystem I and CO2 uptake at high lights. PMID:27329499

  18. 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.

  19. Anchoring a plant cytochrome P450 via PsaM to the thylakoids in Synechococcus sp. PCC 7002: evidence for light-driven biosynthesis.

    Directory of Open Access Journals (Sweden)

    Lærke Münter Lassen

    Full Text Available Plants produce an immense variety of specialized metabolites, many of which are of high value as their bioactive properties make them useful as for instance pharmaceuticals. The compounds are often produced at low levels in the plant, and due to their complex structures, chemical synthesis may not be feasible. Here, we take advantage of the reducing equivalents generated in photosynthesis in developing an approach for producing plant bioactive natural compounds in a photosynthetic microorganism by functionally coupling a biosynthetic enzyme to photosystem I. This enables driving of the enzymatic reactions with electrons extracted from the photosynthetic electron transport chain. As a proof of concept, we have genetically fused the soluble catalytic domain of the cytochrome P450 CYP79A1, originating from the endoplasmic reticulum membranes of Sorghum bicolor, to a photosystem I subunit in the cyanobacterium Synechococcus sp. PCC 7002, thereby targeting it to the thylakoids. The engineered enzyme showed light-driven activity both in vivo and in vitro, demonstrating the possibility to achieve light-driven biosynthesis of high-value plant specialized metabolites in cyanobacteria.

  20. RNA-seq based identification and mutant validation of gene targets related to ethanol resistance in cyanobacterial Synechocystis sp. PCC 6803

    Directory of Open Access Journals (Sweden)

    Wang Jiangxin

    2012-12-01

    Full Text Available Abstract Background Fermentation production of biofuel ethanol consumes agricultural crops, which will compete directly with the food supply. As an alternative, photosynthetic cyanobacteria have been proposed as microbial factories to produce ethanol directly from solar energy and CO2. However, the ethanol productivity from photoautotrophic cyanobacteria is still very low, mostly due to the low tolerance of cyanobacterial systems to ethanol stress. Results To build a foundation necessary to engineer robust ethanol-producing cyanobacterial hosts, in this study we applied a quantitative transcriptomics approach with a next-generation sequencing technology, combined with quantitative reverse-transcript PCR (RT-PCR analysis, to reveal the global metabolic responses to ethanol in model cyanobacterial Synechocystis sp. PCC 6803. The results showed that ethanol exposure induced genes involved in common stress responses, transporting and cell envelope modification. In addition, the cells can also utilize enhanced polyhydroxyalkanoates (PHA accumulation and glyoxalase detoxication pathway as means against ethanol stress. The up-regulation of photosynthesis by ethanol was also further confirmed at transcriptional level. Finally, we used gene knockout strains to validate the potential target genes related to ethanol tolerance. Conclusion RNA-Seq based global transcriptomic analysis provided a comprehensive view of cellular response to ethanol exposure. The analysis provided a list of gene targets for engineering ethanol tolerance in cyanobacterium Synechocystis.

  1. Fine-Tuning of Photoautotrophic Protein Production by Combining Promoters and Neutral Sites in the Cyanobacterium Synechocystis sp. Strain PCC 6803.

    Science.gov (United States)

    Ng, Andrew H; Berla, Bertram M; Pakrasi, Himadri B

    2015-10-01

    Cyanobacteria are photosynthetic cell factories that use solar energy to convert CO2 into useful products. Despite this attractive feature, the development of tools for engineering cyanobacterial chassis has lagged behind that for heterotrophs such as Escherichia coli or Saccharomyces cerevisiae. Heterologous genes in cyanobacteria are often integrated at presumptively "neutral" chromosomal sites, with unknown effects. We used transcriptome sequencing (RNA-seq) data for the model cyanobacterium Synechocystis sp. strain PCC 6803 to identify neutral sites from which no transcripts are expressed. We characterized the two largest such sites on the chromosome, a site on an endogenous plasmid, and a shuttle vector by integrating an enhanced yellow fluorescent protein (EYFP) expression cassette expressed from either the Pcpc560 or the Ptrc1O promoter into each locus. Expression from the endogenous plasmid was as much as 14-fold higher than that from the chromosome, with intermediate expression from the shuttle vector. The expression characteristics of each locus correlated predictably with the promoters used. These findings provide novel, characterized tools for synthetic biology and metabolic engineering in cyanobacteria. PMID:26209663

  2. Unusual radioresistance of nitrogen-fixing cultures of Anabaena strains

    Indian Academy of Sciences (India)

    Harinder Singh; Tonina Fernandes; Shree Kumar Apte

    2010-09-01

    Nitrogen-fixing cultures of two species of the filamentous, heterocystous cyanobacterium Anabaena, namely Anabaena sp. strain L-31 and Anabaena torulosa were found to be highly tolerant to 60Co gamma radiation. No adverse effect on diazotrophic growth and metabolism were observed up to a dose of 5 kGy. At higher doses, radiation tolerance showed a correspondence with the inherent osmotolerance, with Anabaena L-31 being the more radiation tolerant as well as osmotolerant strain. In Anabaena L-31, exposure to 6 kGy of gamma rays resulted in genome disintegration, but did not reduce viability. Irradiation delayed heterocyst differentiation and nitrogen fixation, and marginally affected diazotrophic growth. All the affected parameters recovered after a short lag, without any discernible post-irradiation phenotype. The radiation tolerance of these Gram-negative photoautodiazotrophs is comparable with that of the adiazotrophic photoautotrophic cyanobacterium Chroococcidiopsis or adiazotrophic heterotroph Deinococcus radiodurans. This is the first report of extreme radioresistance in nitrogen-fixing Anabaena cultures.

  3. IdiA, a 34 kDa protein in the cyanobacteria Synechococcus sp. strains PCC 6301 and PCC 7942, is required for growth under iron and manganese limitations.

    Science.gov (United States)

    Michel, K P; Thole, H H; Pistorius, E K

    1996-09-01

    In the cyanobacteria Synechococcus PCC 6301 and PCC 7942 a protein with an apparent molecular mass of about 34 kDa (called IdiA for iron-deficiency-induced protein A) accumulates under iron and managanese limitation. IdiA from Synechococcus PCC 6301 was partially sequenced, showing that the N-terminal amino acid is an alanine. Moreover, the gene encoding this protein in Synechococcus PCC 6301 has been identified and completely sequenced. The idiA gene codes for a protein starting with valine and consisting of 330 amino acid residues. Thus, IdiA is apparently synthesized as a precursor protein of 36.17 kDa and cleaved to its mature form of 35.01 kDa between two alanine residues at positions 9 and 10. IdiA is a highly basic protein having an isoelectric point of 10.55 (mature protein). Comparison of the amino acid sequence of IdiA with protein sequences in the database revealed that IdiA has similarities to two basic bacterial iron-binding proteins, SfuA from Serratia marcescens and Fbp from Neisseria gonorrhoeae. Insertional inactivation of the idiA gene in Synechococcus PCC 7942 resulted in a mutant which was unable to grow under iron- or manganese-limiting conditions. Manganese limitation of the mutant strain led to a drastic reduction of photosystem II activity (O2 evolution) within less than 48 h, while wild-type cells required a prolonged cultivation in Mn-deficient medium before an effect on photosystem II was observed. Thus, IdiA is a protein involved in the process of providing photosystem II with manganese. PMID:8828233

  4. Role of calcium in acclimation of the cyanobacterium Synechococcus elongatus PCC 7942 to nitrogen starvation.

    Science.gov (United States)

    Leganés, Francisco; Forchhammer, Karl; Fernández-Piñas, Francisca

    2009-01-01

    A Ca2+ signal is required for the process of heterocyst differentiation in the filamentous diazotrophic cyanobacterium Anabaena sp. PCC 7120. This paper presents evidence that a transient increase in intracellular free Ca2+ is also involved in acclimation to nitrogen starvation in the unicellular non-diazotrophic cyanobacterium Synechococcus elongatus PCC 7942. The Ca2+ transient was triggered in response to nitrogen step-down or the addition of 2-oxoglutarate (2-OG), or its analogues 2,2-difluoropentanedioic acid (DFPA) and 2-methylenepentanedioic acid (2-MPA), to cells growing with combined nitrogen, suggesting that an increase in intracellular 2-OG levels precedes the Ca2+ transient. The signalling protein P(II) and the transcriptional regulator NtcA appear to be needed to trigger the signal. Suppression of the Ca2+ transient by the intracellular Ca2+ chelator N,N'-[1,2-ethanediylbis(oxy-2,1-phenylene)]bis[N-[2-[(acetyloxy)methoxy]-2-oxoethyl

  5. Oxidation of a Cysteine Residue in Elongation Factor EF-Tu Reversibly Inhibits Translation in the Cyanobacterium Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Yutthanasirikul, Rayakorn; Nagano, Takanori; Jimbo, Haruhiko; Hihara, Yukako; Kanamori, Takashi; Ueda, Takuya; Haruyama, Takamitsu; Konno, Hiroki; Yoshida, Keisuke; Hisabori, Toru; Nishiyama, Yoshitaka

    2016-03-11

    Translational elongation is susceptible to inactivation by reactive oxygen species (ROS) in the cyanobacterium Synechocystis sp. PCC 6803, and elongation factor G has been identified as a target of oxidation by ROS. In the present study we examined the sensitivity to oxidation by ROS of another elongation factor, EF-Tu. The structure of EF-Tu changes dramatically depending on the bound nucleotide. Therefore, we investigated the sensitivity to oxidation in vitro of GTP- and GDP-bound EF-Tu as well as that of nucleotide-free EF-Tu. Assays of translational activity with a reconstituted translation system from Escherichia coli revealed that GTP-bound and nucleotide-free EF-Tu were sensitive to oxidation by H2O2, whereas GDP-bound EF-Tu was resistant to H2O2. The inactivation of EF-Tu was the result of oxidation of Cys-82, a single cysteine residue, and subsequent formation of both an intermolecular disulfide bond and sulfenic acid. Replacement of Cys-82 with serine rendered EF-Tu resistant to inactivation by H2O2, confirming that Cys-82 was a target of oxidation. Furthermore, oxidized EF-Tu was reduced and reactivated by thioredoxin. Gel-filtration chromatography revealed that some of the oxidized nucleotide-free EF-Tu formed large complexes of >30 molecules. Atomic force microscopy revealed that such large complexes dissociated into several smaller aggregates upon the addition of dithiothreitol. Immunological analysis of the redox state of EF-Tu in vivo showed that levels of oxidized EF-Tu increased under strong light. Thus, resembling elongation factor G, EF-Tu appears to be sensitive to ROS via oxidation of a cysteine residue, and its inactivation might be reversed in a redox-dependent manner. PMID:26786107

  6. Global transcriptional response of the alkali-tolerant cyanobacterium Synechocystis sp. strain PCC 6803 to a pH 10 environment.

    Science.gov (United States)

    Summerfield, Tina C; Sherman, Louis A

    2008-09-01

    Many cyanobacterial strains are able to grow at a pH range from neutral to pH 10 or 11. Such alkaline conditions favor cyanobacterial growth (e.g., bloom formation), and cyanobacteria must have developed strategies to adjust to changes in CO2 concentration and ion availability. Synechocystis sp. strain PCC 6803 exhibits similar photoautotrophic growth characteristics at pH 10 and pH 7.5, and we examined global gene expression following transfer from pH 7.5 to pH 10 to determine cellular adaptations at an elevated pH. The strategies used to develop homeostasis at alkaline pH had elements similar to those of many bacteria, as well as components unique to phototrophic microbes. Some of the response mechanisms previously identified in other bacteria included upregulation of Na+/H+ antiporters, deaminases, and ATP synthase. In addition, upregulated genes encoded transporters with the potential to contribute to osmotic, pH, and ion homeostasis (e.g., a water channel protein, a large-conductance mechanosensitive channel, a putative anion efflux transporter, a hexose/proton symporter, and ABC transporters of unidentified substrates). Transcriptional changes specific to photosynthetic microbes involved NADH dehydrogenases and CO2 fixation. The pH transition altered the CO2/HCO3(-) ratio within the cell, and the upregulation of three inducible bicarbonate transporters (BCT1, SbtA, and NDH-1S) likely reflected a response to this perturbed ratio. Consistent with this was increased transcript abundance of genes encoding carboxysome structural proteins and carbonic anhydrase. Interestingly, the transition to pH 10 resulted in increased abundance of transcripts of photosystem II genes encoding extrinsic and low-molecular-weight polypeptides, although there was little change in photosystem I gene transcripts. PMID:18606800

  7. The optimal mutagen dosage to induce point-mutations in Synechocystis sp. PCC6803 and its application to promote temperature tolerance.

    Directory of Open Access Journals (Sweden)

    Ulrich M Tillich

    Full Text Available Random mutagenesis is a useful tool to genetically modify organisms for various purposes, such as adaptation to cultivation conditions, the induction of tolerances, or increased yield of valuable substances. This is especially attractive for systems where it is not obvious which genes require modifications. Random mutagenesis has been extensively used to modify crop plants, but even with the renewed interest in microalgae and cyanobacteria for biofuel applications, there is relatively limited current research available on the application of random mutagenesis for these organisms, especially for cyanobacteria. In the presented work we characterized the lethality and rate of non-lethal point mutations for ultraviolet radiation and methyl methanesulphonate on the model cyanobacteria Synechocystis sp. PCC6803. Based on these results an optimal dosage of 10-50 J/m(2 for UV and either 0.1 or 1 v% for MMS was determined. A Synechocystis wildtype culture was then mutagenized and selected for increased temperature tolerance in vivo. During the second round of mutagenesis the viability of the culture was monitored on a cell by cell level from the treatment of the cells up to the growth at an increased temperature. After four distinct rounds of treatment (two with each mutagen the temperature tolerance of the strain was effectively raised by about 2°C. Coupled with an appropriate in vivo screening, the described methods should be applicable to induce a variety of desirable characteristics in various strains. Coupling random mutagenesis with high-throughput screening methods would additionally allow to select for important characteristics for biofuel production, which do not yield a higher fitness and can not be selected for in vivo, such as fatty acid concentration. In a combined approach with full genome sequencing random mutagenesis could be used to determine suitable target-genes for more focused methods.

  8. Trade-Off between Growth and Carbohydrate Accumulation in Nutrient-Limited Arthrospira sp. PCC 8005 Studied by Integrating Transcriptomic and Proteomic Approaches.

    Directory of Open Access Journals (Sweden)

    Orily Depraetere

    Full Text Available Cyanobacteria have a strong potential for biofuel production due to their ability to accumulate large amounts of carbohydrates. Nitrogen (N stress can be used to increase the content of carbohydrates in the biomass, but it is expected to reduce biomass productivity. To study this trade-off between carbohydrate accumulation and biomass productivity, we characterized the biomass productivity, biomass composition as well as the transcriptome and proteome of the cyanobacterium Arthrospira sp. PCC 8005 cultured under N-limiting and N-replete conditions. N limitation resulted in a large increase in the carbohydrate content of the biomass (from 14 to 74% and a decrease in the protein content (from 37 to 10%. Analyses of fatty acids indicated that no lipids were accumulated under N-limited conditions. Nevertheless, it did not affect the biomass productivity of the culture up to five days after N was depleted from the culture medium. Transcriptomic and proteomic analysis indicated that de novo protein synthesis was down-regulated in the N-limited culture. Proteins were degraded and partly converted into carbohydrates through gluconeogenesis. Cellular N derived from protein degradation was recycled through the TCA and GS-GOGAT cycles. In addition, photosynthetic energy production and carbon fixation were both down-regulated, while glycogen synthesis was up-regulated. Our results suggested that N limitation resulted in a redirection of photosynthetic energy from protein synthesis to glycogen synthesis. The fact that glycogen synthesis has a lower energy demand than protein synthesis might explain why Arthrospira is able to achieve a similar biomass productivity under N-limited as under N-replete conditions despite the fact that photosynthetic energy production was impaired by N limitation.

  9. Transcription profiling of the model cyanobacterium Synechococcus sp. strain PCC 7002 by NextGen (SOLiD™ Sequencing of cDNA

    Directory of Open Access Journals (Sweden)

    Marcus eLudwig

    2011-03-01

    Full Text Available The genome of the unicellular, euryhaline cyanobacterium Synechococcus sp. PCC 7002 encodes about 3200 proteins. Transcripts were detected for nearly all annotated open reading frames by a global transcriptomic analysis by Next-Generation (SOLiDTM sequencing of cDNA. In the cDNA samples sequenced, ~90% of the mapped sequences were derived from the 16S and 23S ribosomal RNAs and ~10% of the sequences were derived from mRNAs. In cells grown photoautotrophically under standard conditions (38 °C, 1% (v/v CO2 in air, 250 µmol photons m-2 s-1, the highest transcript levels (up to 2% of the total mRNA for the most abundantly transcribed genes (e. g., cpcAB, psbA, psaA were generally derived from genes encoding structural components of the photosynthetic apparatus. High light exposure for one hour caused changes in transcript levels for genes encoding proteins of the photosynthetic apparatus, Type-1 NADH dehydrogenase complex and ATP synthase, whereas dark incubation for one hour resulted in a global decrease in transcript levels for photosynthesis-related genes and an increase in transcript levels for genes involved in carbohydrate degradation. Transcript levels for pyruvate kinase and the pyruvate dehydrogenase complex decreased sharply in cells incubated in the dark. Under dark anoxic (fermentative conditions, transcript changes indicated a global decrease in transcripts for respiratory proteins and suggested that cells employ an alternative phosphoenolpyruvate degradation pathway via phosphoenolpyruvate synthase (ppsA and the pyruvate:ferredoxin oxidoreductase (nifJ. Finally, the data suggested that an apparent operon involved in tetrapyrrole biosynthesis and fatty acid desaturation, acsF2-ho2-hemN2-desF, may be regulated by oxygen concentration.

  10. Far-red light photoacclimation: Chromophorylation of FR induced α- and β-subunits of allophycocyanin from Chroococcidiopsis thermalis sp. PCC7203.

    Science.gov (United States)

    Xu, Qian-Zhao; Han, Jia-Xin; Tang, Qi-Ying; Ding, Wen-Long; Miao, Dan; Zhou, Ming; Scheer, Hugo; Zhao, Kai-Hong

    2016-09-01

    Cyanobacterial light-harvesting complexes, phycobilisomes, can undergo extensive remodeling under varying light conditions. Acclimation to far-red light involves not only generation of red-shifted chlorophylls in the photosystems, but also induction of additional copies of core biliproteins that have been related to red-shifted components of the phycobilisome (Gan et al., Life 5, 4, 2015). We are studying the molecular basis for these acclimations in Chroococcidiopsis thermalis sp. PCC7203. Five far-red induced allophycocyanin subunits (ApcA2, ApcA3, ApcB2, ApcB3 and ApcF2) were expressed in Escherichia coli, together with S-type chromophore-protein lyases and in situ generated chromophore, phycocyanobilin. Only one subunit, ApcF2, shows an unusual red-shift (λAmax~675nm, λFmax~698nm): it binds the chromophore non-covalently, thereby preserving its full conjugation length. This mechanism operates also in two Cys-variants of the induced subunits of bulky APC. All other wild-type subunits bind phycocyanobilin covalently to the conventional Cys-81 under catalysis of the lyase, CpcS1. Although three of them also show binding to additional cysteines, all absorb and fluoresce similar to conventional APC subunits (λAmax~610nm, λFmax~640nm). Another origin of red-shifted complexes was identified, however, when different wild-type α- and β-subunits of the far-red induced bulky APC were combined in a combinatorial fashion. Strongly red-shifted complexes (λFmax≤722nm) were formed when the α-subunit, PCB-ApcA2, and the β-subunit, PCB-ApcB2, were generated together in E. coli. This extreme aggregation-induced red-shift of ~90nm of covalently bound chromophores is reminiscent, but much larger, than the ~30nm observed with conventional APC. PMID:27368145

  11. Photosynthetic Regulation of the Cyanobacterium Synechocystis sp. PCC 6803 Thioredoxin System and Functional Analysis of TrxB (Trx x) and TrxQ (Trx y) Thioredoxins

    Institute of Scientific and Technical Information of China (English)

    M. Esther Pérez-Pérez; Eugenio Martín-Figueroa; Francisco J. Florencio

    2009-01-01

    The expression of the genes encoding the ferredoxin-thioredoxin system including the ferredoxin-thiore-doxin reductase (FTR) genes ftrC and ftrV and the four different thioredoxin genes trxA (m-type; slr0623), trxB (x-type; slr1139), trxC (sll1057) and trxQ (y-type; slr0233) of the cyanobacterium Synechocystis sp. PCC 6803 has been studied according to changes in the photosynthetic conditions. Experiments of light-dark transition indicate that the expression of all these genes except trxQ decreases in the dark in the absence of glucose in the growth medium. The use of two electron transport inhibitors, 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) and 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB), reveals a differential effect on thioredoxin genes expression being trxC and trxQ almost unaf-fected, whereas trxA, trxB, and the ftr genes are down-regulated. In the presence of glucose, DCMU does not affect gene expression but DBMIB still does. Analysis of the single TrxB or TrxQ and the double TrxB TrxQ Synechocystis mutant strains reveal different functions for each of these thioredoxins under different growth conditions. Finally, a Synechocystis strain was generated containing a mutated version of TrxB (TrxBC34S), which was used to identify the potential in-vivo targets of this thioredoxin by a proteomic analysis.

  12. Characterization of the relA/spoT homologue slr1325 (syn-rsh) of the cyanobacterium Synechocystis sp.PCC6803%集胞藻PCC6803中relA/spoT同源基因syn-rsh(slr1325)的鉴定

    Institute of Scientific and Technical Information of China (English)

    缪小刚; 刘惠玲; 宁德刚

    2011-01-01

    [目的]四磷酸或五磷酸鸟苷(Guanosine 3′,5′-bispyrophosphate,(p)ppGpp)是细菌在遭遇环境胁迫时细胞产生应激反应的信号分子,(p)ppGpp由其合成酶RelA或具有合成酶或水解酶双重催化功能的RelA/SpoT合成.本文证明了集胞藻PCC6803(Synechocystis sp.)中唯一编码RelA/SpoT同源蛋白(命名为Syn-RSH)的基因slr1325(syn-rsh)的功能.[方法]通过互补试验证明syn-rsh表达产物的生物学功能;以纤维素薄层层析检测不同条件下Escherichia coli(p)ppGpp合成缺陷突变株及集胞藻PCC6803细胞中的(p)ppGpp.[结果]诱导Syn-RSH表达可使(p)ppGpp合成酶和水解酶基因缺失的E.coli突变株回复野生型表型,并在细胞中积累一定水平的ppGpp;在实验室培养条件下,集胞藻PCC6803细胞中可检测到低水平的ppGpp,氨基酸饥饿可诱导ppGpp水平升高并维持在相应水平.[结论]Syn-RSH具有(p)ppGpp合成酶和水解酶的双重功能,(p)ppGpp是集胞藻PCC6803在实验室生长条件下细胞生长所必需的.

  13. 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

  14. Transducción de señales de estrés por el regulador de respuesta NblR en la cianobacteria Synechococcus sp. PCC7942

    OpenAIRE

    Ruiz Martinich, Diego; Salinas Berná, Paloma; Moronta Barrios, Félix; Cantos Coll, Raquel; Contreras de Vera, Asunción

    2009-01-01

    Mediante el proceso de clorosis o bleaching Synechococcus sp. PCC 7942 degrada los complejos antena del aparato fotosintético en respuesta a carencia prolongada de nitrógeno y otros factores de estrés. La activación del gen nblA, sometido a una compleja regulación, es esencial en este proceso, aunque la adaptación a estrés requiere la regulación de múltiples funciones, la mayoría desconocidas. El regulador de respuesta NblR activa fuertemente a nblA en condiciones de estrés. Además, la histid...

  15. Under light limiting growth, CpcB lyase null mutants of the Cyanobacterium Synechococcus sp. PCC 7002 are capable of producing pigmented beta phycocyanin but with altered chromophore function.

    Science.gov (United States)

    Derks, Allen K; Vasiliev, Serguei; Bruce, Doug

    2008-11-11

    Phycobilisomes are the major light-harvesting complexes for cyanobacteria, and phycocyanin is the primary phycobiliprotein of the phycobilisome rod. Phycocyanobilin chromophores are covalently bonded to the phycocyanin beta subunit (CpcB) by specific lyases which have been recently identified in the cyanobacterium Synechococcus sp. PCC 7002. Surprisingly, we found that mutants missing the CpcB lyases were nevertheless capable of producing pigmented phycocyanin when grown under low-light conditions. Absorbance measurements at 10 K revealed the energy states of the beta phycocyanin chromophores to be slightly shifted, and 77 K steady state fluorescence emission spectroscopy showed that excitation energy transfer involving the targeted chromophores was disrupted. This evidence indicates that the position of the phycocyanobilin chromophore within the binding domain of the phycocyanin beta subunit had been modified. We hypothesize that alternate, less specific lyases are able to add chromophores, with varying effectiveness, to the beta binding sites. PMID:18925744

  16. Proteome Analyses of Strains ATCC 51142 and PCC 7822 of the Diazotrophic Cyanobacterium Cyanothece sp under Culture Conditions Resulting in Enhanced H-2 Production

    Energy Technology Data Exchange (ETDEWEB)

    Aryal, Uma K.; Callister, Stephen J.; Mishra, Sujata; Zhang, Xiaohui; Shutthanandan, Janani I.; Angel, Thomas E.; Shukla, Anil K.; Monroe, Matthew E.; Moore, Ronald J.; Koppenaal, David W.; Smith, Richard D.; Sherman, Louis

    2013-02-01

    Cultures of the cyanobacterial genus Cyanothece have been shown to produce high levels of biohydrogen. These strains are diazotrophic and undergo pronounced diurnal cycles when grown under N2-fixing conditions in light-dark cycles. We seek to better understand the way in which proteins respond to these diurnal changes and we performed quantitative proteome analysis of Cyanothece ATCC 51142 and PCC 7822 grown under 8 different nutritional conditions. Nitrogenase expression was limited to N2-fixing conditions, and in the absence of glycerol, nitrogenase gene expression was linked to the dark period. However, glycerol induced expression of nitrogenase during part of the light period, together with cytochrome c oxidase (Cox), glycogen phosphorylase (Glp), and glycolytic and pentose-phosphate pathway (PPP) enzymes. This indicated that nitrogenase expression in the light was facilitated via higher respiration and glycogen breakdown. Key enzymes of the Calvin cycle were inhibited in Cyanothece ATCC 51142 in the presence of glycerol under H2 producing conditions, suggesting a competition between these sources of carbon. However, in Cyanothece PCC 7822, the Calvin cycle still played a role in cofactor recycling during H2 production. Our data comprise the first comprehensive profiling of proteome changes in Cyanothece PCC 7822, and allows an in-depth comparative analysis of major physiological and biochemical processes that influence H2-production in both the strains. Our results revealed many previously uncharacterized proteins that may play a role in nitrogenase activity and in other metabolic pathways and may provide suitable targets for genetic manipulation that would lead to improvement of large scale H2 production.

  17. Adapting photosynthesis to the near-infrared: non-covalent binding of phycocyanobilin provides an extreme spectral red-shift to phycobilisome core-membrane linker from Synechococcus sp. PCC7335.

    Science.gov (United States)

    Miao, Dan; Ding, Wen-Long; Zhao, Bao-Qing; Lu, Lu; Xu, Qian-Zhao; Scheer, Hugo; Zhao, Kai-Hong

    2016-06-01

    Phycobiliproteins that bind bilins are organized as light-harvesting complexes, phycobilisomes, in cyanobacteria and red algae. The harvested light energy is funneled to reaction centers via two energy traps, allophycocyanin B and the core-membrane linker, ApcE1 (conventional ApcE). The covalently bound phycocyanobilin (PCB) of ApcE1 absorbs near 660nm and fluoresces near 675nm. In cyanobacteria capable of near infrared photoacclimation, such as Synechococcus sp. PCC7335, there exist even further spectrally red shifted components absorbing >700nm and fluorescing >710nm. We expressed the chromophore domain of the extra core-membrane linker from Synechococcus sp. PCC7335, ApcE2, in E. coli together with enzymes generating the chromophore, PCB. The resulting chromoproteins, PCB-ApcE2(1-273) and the more truncated PCB-ApcE2(24-245), absorb at 700nm and fluoresce at 714nm. The red shift of ~40nm compared with canonical ApcE1 results from non-covalent binding of the chromophore by which its full conjugation length including the Δ3,3(1) double bond is preserved. The extreme spectral red-shift could not be ascribed to exciton coupling: dimeric PCB-ApcE2(1-273) and monomeric-ApcE2(24-245) absorbed and fluoresced similarly. Chromophorylation of ApcE2 with phycoerythrobilin- or phytochromobilin resulted in similar red shifts (absorption at 615 and 711nm, fluorescence at 628 or 726nm, respectively), compared to the covalently bound chromophores. The self-assembled non-covalent chromophorylation demonstrates a novel access to red and near-infrared emitting fluorophores. Brightly fluorescent biomarking was exemplified in E. coli by single-plasmid transformation. PMID:27045046

  18. 集胞藻PCC6803中S2P同源蛋白Slr0643及Sll0862金属蛋白酶活性的体外鉴定%Characterization of metalloprotease of Slr0643 and Sll0862, the S2P homologs from Synechocystis sp.PCC6803

    Institute of Scientific and Technical Information of China (English)

    秦春燕; 张旭; 陈谷

    2012-01-01

    [Objective] It is a conserved mechanism in bacteria that metalloprotease site-2 protease ( S2P) cleaves transmembrane anti-sigma factor to release sequestered sigma factor in response to extracytoplasmic stress. However, the function of site-2 protease homologs in cyanobacteria remains elusive, so we investigated the metalloprotease activity of Slr0643 and S110862, the site-2 protease homologs from Synechocystis sp. PCC6803. [Methods] Recombinant Slr0643 and S110862 were constructed and overexpressed in Escherichia coli BL21(CE3). Their protease activities were tested against β-casein and then resolved on SDS-PAGE. [Results] Results from caseinolytic assay indicated that Slr0643 and S110862 have proteolytic activity which is blocked by o-phenanthroline, a metalloprotease inhibitor. These metalloprotease activity of Slr0643 and S110862 in vitro provide the foundation for futher analysis of their substrates in vivo. [Conclusion] The site-2 protease homologs in Synechocystis sp. PCC6803 have metalloprotease activity.%[目的]金属蛋白酶S2P在细菌中通过在膜切割转录调控因子、释放δ因子参与胁迫响应是跨膜信号转导的保守机制,但蓝细菌中S2P的功能还未被鉴定,故我们考察集胞藻PCC6803中的S2P同源蛋白Slr0643及Sll0862的金属蛋白酶活性.[方法]以pET-30b(+)为载体,分别构建重组质粒pF0643和pF0862,在大肠杆菌BL21( CE3)中诱导表达并纯化Slr0643及Sll0862蛋白,以β-酪蛋白为底物检测重组蛋白的酶活性.[结果]体外酶活实验显示重组表达的Slr0643及Sll0862蛋白有内切蛋白酶活性,且其活性受金属螯合剂o-phenanthroline的抑制.体外酶活的鉴定结果为进一步研究Slr0643和Sll0862的体内酶活和生物学功能奠定了基础.[结论]集胞藻PCC6803中的S2P同源蛋白Slr0643及Sll0862具有金属蛋白酶活性.

  19. Viruses Infecting a Freshwater Filamentous Cyanobacterium (Nostoc sp.) Encode a Functional CRISPR Array and a Proteobacterial DNA Polymerase B

    Science.gov (United States)

    Chénard, Caroline; Wirth, Jennifer F.

    2016-01-01

    ABSTRACT   Here we present the first genomic characterization of viruses infecting Nostoc, a genus of ecologically important cyanobacteria that are widespread in freshwater. Cyanophages A-1 and N-1 were isolated in the 1970s and infect Nostoc sp. strain PCC 7210 but remained genomically uncharacterized. Their 68,304- and 64,960-bp genomes are strikingly different from those of other sequenced cyanophages. Many putative genes that code for proteins with known functions are similar to those found in filamentous cyanobacteria, showing a long evolutionary history in their host. Cyanophage N-1 encodes a CRISPR array that is transcribed during infection and is similar to the DR5 family of CRISPRs commonly found in cyanobacteria. The presence of a host-related CRISPR array in a cyanophage suggests that the phage can transfer the CRISPR among related cyanobacteria and thereby provide resistance to infection with competing phages. Both viruses also encode a distinct DNA polymerase B that is closely related to those found in plasmids of Cyanothece sp. strain PCC 7424, Nostoc sp. strain PCC 7120, and Anabaena variabilis ATCC 29413. These polymerases form a distinct evolutionary group that is more closely related to DNA polymerases of proteobacteria than to those of other viruses. This suggests that the polymerase was acquired from a proteobacterium by an ancestral virus and transferred to the cyanobacterial plasmid. Many other open reading frames are similar to a prophage-like element in the genome of Nostoc sp. strain PCC 7524. The Nostoc cyanophages reveal a history of gene transfers between filamentous cyanobacteria and their viruses that have helped to forge the evolutionary trajectory of this previously unrecognized group of phages. PMID:27302758

  20. Mutation of Gly195 of the ChlH Subunit of Mg-chelatase Reduces Chlorophyll and Further Disrupts PS II Assembly in a Ycf48-Deficient Strain of Synechocystis sp. PCC 6803

    Science.gov (United States)

    Crawford, Tim S.; Eaton-Rye, Julian J.; Summerfield, Tina C.

    2016-01-01

    Biogenesis of the photosystems in oxygenic phototrophs requires co-translational insertion of chlorophyll a. The first committed step of chlorophyll a biosynthesis is the insertion of a Mg2+ ion into the tetrapyrrole intermediate protoporphyrin IX, catalyzed by Mg-chelatase. We have identified a Synechocystis sp. PCC 6803 strain with a spontaneous mutation in chlH that results in a Gly195 to Glu substitution in a conserved region of the catalytic subunit of Mg-chelatase. Mutant strains containing the ChlH Gly195 to Glu mutation were generated using a two-step protocol that introduced the chlH gene into a putative neutral site in the chromosome prior to deletion of the native gene. The Gly195 to Glu mutation resulted in strains with decreased chlorophyll a. Deletion of the PS II assembly factor Ycf48 in a strain carrying the ChlH Gly195 to Glu mutation did not grow photoautotrophically. In addition, the ChlH-G195E:ΔYcf48 strain showed impaired PS II activity and decreased assembly of PS II centers in comparison to a ΔYcf48 strain. We suggest decreased chlorophyll in the ChlH-G195E mutant provides a background to screen for the role of assembly factors that are not essential under optimal growth conditions. PMID:27489555

  1. 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

  2. Hydrogen uptake by Azolla-Anabaena

    International Nuclear Information System (INIS)

    The hydrogen uptake in the Azolla-Anabaena system is studied. Tritium is used as tracer. Plants are incubated under different atmosphere composition: a) Air + 3H2; b) Air + CO2 + 3H2 + CO; c) Air + 3H2 + CO; d) Air + CO2 + 3H2 + CO to study the pathway of absorbed hydrogen in the Azolla - Anabaena system. Azolla-Anabaena showed greater hydrogen uptake under argonium atmosphere than under air. Carbon monoxide decreased hydrogen uptake. There are evidences of recycling of the hydrogen evolved through notrogenease. (Author)

  3. Fluorescence changes accompanying short-term light adaptations in photosystem I and photosystem II of the cyanobacterium Synechocystis sp. PCC 6803 and phycobiliprotein-impaired mutants: State 1/State 2 transitions and carotenoid-induced quenching of phycobilisomes.

    Science.gov (United States)

    Stadnichuk, Igor N; Lukashev, Evgeny P; Elanskaya, Irina V

    2009-03-01

    The features of the two types of short-term light-adaptations of photosynthetic apparatus, State 1/State 2 transitions, and non-photochemical fluorescence quenching of phycobilisomes (PBS) by orange carotene-protein (OCP) were compared in the cyanobacterium Synechocystis sp. PCC 6803 wild type, CK pigment mutant lacking phycocyanin, and PAL mutant totally devoid of phycobiliproteins. The permanent presence of PBS-specific peaks in the in situ action spectra of photosystem I (PSI) and photosystem II (PSII), as well as in the 77 K fluorescence excitation spectra for chlorophyll emission at 690 nm (PSII) and 725 nm (PSI) showed that PBS are constitutive antenna complexes of both photosystems. The mutant strains compensated the lack of phycobiliproteins by higher PSII content and by intensification of photosynthetic linear electron transfer. The detectable changes of energy migration from PBS to the PSI and PSII in the Synechocystis wild type and the CK mutant in State 1 and State 2 according to the fluorescence excitation spectra measurements were not registered. The constant level of fluorescence emission of PSI during State 1/State 2 transitions and simultaneous increase of chlorophyll fluorescence emission of PSII in State 1 in Synechocystis PAL mutant allowed to propose that spillover is an unlikely mechanism of state transitions. Blue-green light absorbed by OCP diminished the rout of energy from PBS to PSI while energy migration from PBS to PSII was less influenced. Therefore, the main role of OCP-induced quenching of PBS is the limitation of PSI activity and cyclic electron transport under relatively high light conditions. PMID:19169839

  4. Antibacterial phycocyanin from Anabaena oryzae SOS13

    OpenAIRE

    Mahmoud Sitohy; Ali Osman; Abdel Ghany Abdel Ghany; Ali Salama

    2015-01-01

    Summary. The antimicrobial activity of phycocyanin extracted from Anabaena oryzae SOS13 was assayed against 4 pathogenic bacteria using agar well-diffusion assay and using benzyl Penicillin, Clindamycin, Ofloxacin and Doxycycline as positive controls. The concentration inhibiting 50% bacterial growth and the minimum inhibition concentration (MIC). The mode of action of phycocyanin on bacteria was explored using electron microscopy (SEM & TEM). Phycocyanin from Anabaena oryzae SOS13 has α and ...

  5. COMPARATIVE GROWTH AND BIOCHEMICAL COMPOSITION OF FOUR STRAINS OF Nostoc AND Anabaena (CYANOBACTERIA, NOSTOCALES IN RELATION TO SODIUM NITRATE

    Directory of Open Access Journals (Sweden)

    Néstor Rosales Loaiza

    2016-04-01

    Full Text Available ABSTRACTNitrogen concentration is an essential parameter in cyanobacterial cultures to produce enriched biomass with biotechnological purposes. Growth and biochemical composition of Nostoc LAUN0015, Nostoc UAM206, Anabaena sp.1 and Anabaena sp.2 were compared at 0, 4.25, 8.5 and 17 mM NaNO3. Cultures under laboratory conditions were maintained for 30 days at a volume of 500 mL. Anabaena sp.1 yielded the highest value of dry mass of 0.26 ± 2.49 mg mL-1 at 8.5 mM NaNO3. For chlorophyll, phycocyanin and phycoerythrin, maximum values were achieved at 17 mM NaNO3 with 18.09 ± 1.74, 102.90 ± 6.73 and 53.47 ± 2.40 μg mL-1, respectively. Nostoc LAUN0015 produced its maximum value of protein 644.86 ± 19.77 μg mL-1, and 890 mg mL-1 of carbohydrates in the absence of nitrogen. This comparative study shows that the most efficient strain for the production of protein, carbohydrates and lipids in diazotrophic conditions corresponded to Nostoc LAUN0015. However, Anabaena sp.1 and Anabaena sp.2 required high nitrogen concentrations to achieve higher values of metabolites, comparing with Nostoc strains. Nitrogen dependence for the production of pigments and high protein production in strains of Anabaena and in diazotrophic conditions for Nostoc was demonstrated. Nostoc can be cultured under nitrogen deficiency and Anabaena in sufficiency, for biomass production enriched with proteins and carbohydrates.Comparación del crecimiento y Composición Bioquímica de cuatro cepas de Nostoc y Anabaena (Cyanobacteria, Nostocales en relación con el nitrato de sodioRESUMENLa concentración de nitrógeno constituye un parámetro esencial en cultivos de cianobacterias para la producción de biomasa enriquecida con fines biotecnológicos. Se comparó el crecimiento y composición bioquímica de las cepas Nostoc LAUN0015, Nostoc UAM206, Anabaena sp.1 y Anabaena sp.2 a 0, 4,25; 8,5 y 17 mM NaNO3. Los cultivos en condiciones de laboratorio fueron mantenidos durante 30 d

  6. Relationships between the ABC-exporter HetC and peptides that regulate the spatiotemporal pattern of heterocyst distribution in Anabaena.

    Directory of Open Access Journals (Sweden)

    Laura Corrales-Guerrero

    Full Text Available In the model cyanobacterium Anabaena sp. PCC 7120, cells called heterocysts that are specialized in the fixation of atmospheric nitrogen differentiate from vegetative cells of the filament in the absence of combined nitrogen. Heterocysts follow a specific distribution pattern along the filament, and a number of regulators have been identified that influence the heterocyst pattern. PatS and HetN, expressed in the differentiating cells, inhibit the differentiation of neighboring cells. At least PatS appears to be processed and transferred from cell to cell. HetC is similar to ABC exporters and is required for differentiation. We present an epistasis analysis of these regulatory genes and of genes, hetP and asr2819, successively downstream from hetC, and we have studied the localization of HetC and HetP by use of GFP fusions. Inactivation of patS, but not of hetN, allowed differentiation to proceed in a hetC background, whereas inactivation of hetC in patS or patS hetN backgrounds decreased the frequency of contiguous proheterocysts. A HetC-GFP protein is localized to the heterocysts and especially near their cell poles, and a putative HetC peptidase domain was required for heterocyst differentiation but not for HetC-GFP localization. hetP is also required for heterocyst differentiation. A HetP-GFP protein localized mostly near the heterocyst poles. ORF asr2819, which we denote patC, encodes an 84-residue peptide and is induced upon nitrogen step-down. Inactivation of patC led to a late spreading of the heterocyst pattern. Whereas HetC and HetP appear to have linked functions that allow heterocyst differentiation to progress, PatC may have a role in selecting sites of differentiation, suggesting that these closely positioned genes may be functionally related.

  7. Induction of siderophore activity in Anabaena spp. and its moderation of copper toxicity.

    OpenAIRE

    Clarke, S E; Stuart, J.; Sanders-Loehr, J

    1987-01-01

    Growth of Anabaena sp. strain 7120 (in the absence of chelators or added iron) was inhibited by the addition of 2.1 to 6.5 microM copper and was abolished by copper concentration of 10 microM or higher. When the copper was chelated to schizokinen (the siderophore produced by this organism in response to iron starvation), the toxic effects were eliminated. Analysis of culture filtrates showed that the cupric schizokinen remains in the medium, thereby lowering the amount of copper taken up by t...

  8. A Feed-Forward Loop Consisting of the Response Regulator RpaB and the Small RNA PsrR1 Controls Light Acclimation of Photosystem I Gene Expression in the Cyanobacterium Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Kadowaki, Taro; Nagayama, Ryuta; Georg, Jens; Nishiyama, Yoshitaka; Wilde, Annegret; Hess, Wolfgang R; Hihara, Yukako

    2016-04-01

    Since cyanobacteria need to decrease PSI content to avoid absorption of excess light energy, down-regulation of PSI gene expression is one of the key characteristics of the high-light (HL) acclimation response. The transcriptional regulator RpaB and the small RNA PsrR1 (photosynthesis regulatory RNA1) have been suggested to be the two most critical factors for this response inSynechocystissp. PCC 6803. In this study, we found that the HLR1 DNA-binding motif, the recognition sequence for RpaB, is highly conserved in the core promoter region of thepsrR1gene among cyanobacterial species. Gel mobility shift assay revealed that RpaB binds to the HLR1 sequence ofpsrR1in vitro. RNA gel blot analysis together with chromatin affinity purification (ChAP) analysis suggested that PSI genes are activated and thepsrR1gene is repressed by the binding of RpaB under low-light (LL) conditions. A decrease in DNA binding affinity of RpaB occurs within 5 min after the shift from LL to HL conditions, leading to the prompt decrease in PSI promoter activity together with derepression ofpsrR1gene expression. Accumulating PsrR1 molecules then prevent translation from pre-existing PSI transcripts. By this dual repression at transcriptional and post-transcriptional levels, rapid and strict down-regulation of PSI expression under HL is secured. Our findings suggest that RpaB and PsrR1 constitute a feed-forward loop for the regulation of PSI gene expression to achieve a rapid acclimation response to the damaging HL conditions. PMID:26872833

  9. 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

  10. Comparative transcriptomics between Synechococcus PCC 7942 and Synechocystis PCC 6803 provide insights into mechanisms of stress acclimation.

    Directory of Open Access Journals (Sweden)

    Konstantinos Billis

    Full Text Available Synechococcus sp. PCC 7942 and Synechocystis sp. PCC 6803 are model cyanobacteria from which the metabolism and adaptive responses of other cyanobacteria are inferred. Using stranded and 5' enriched libraries, we measured the gene expression response of cells transferred from reference conditions to stress conditions of decreased inorganic carbon, increased salinity, increased pH, and decreased illumination at 1-h and 24-h after transfer. We found that the specific responses of the two strains were by no means identical. Transcriptome profiles allowed us to improve the structural annotation of the genome i.e. identify possible missed genes (including anti-sense, alter gene coordinates and determine transcriptional units (operons. Finally, we predicted associations between proteins of unknown function and biochemical pathways by revealing proteins of known functions that are co-regulated with the unknowns. Future studies of these model organisms will benefit from the cataloging of their responses to environmentally relevant stresses, and improvements in their genome annotations found here.

  11. Effect of pH on growth and competition of Chlorella vulga and Anabaenasp.strain PCC%pH对鱼腥藻和普通小球藻生长竞争的影响

    Institute of Scientific and Technical Information of China (English)

    陈家长; 王菁; 裘丽萍; 孟顺龙; 范立民; 宋超

    2014-01-01

    pH值是藻类生长环境的重要理化指标,它可以通过改变环境酸碱度和碳酸盐平衡系统及不同形态无机碳分配关系来影响藻类的生长。为揭示水体中常见藻类的生长过程及其与pH的相互关系,设置了6.0,7.0,8.0和9.0等4个pH梯度,通过室内实验模拟水体条件,研究不同pH条件下主要水华藻类--鱼腥藻(Anabaena sp.strain PCC)和常见淡水藻类--普通小球藻(Chlorella vulga)的生长和种间竞争。结果表明,无论是在单种培养还是在共同培养体系中,4个pH条件下两种藻类的最大生物量差异显著(P<0.05),鱼腥藻和普通小球藻的最适pH均为9.0,其中单种培养时鱼腥藻和普通小球藻的最大生物量分别为4473.5×104,689.6×104 cells·mL-1;共同培养时鱼腥藻和普通小球藻的最大生物量分别为2798.0×104,296.5×104 cells·mL-1。竞争试验结果表明,pH对藻类种间竞争抑制参数能够产生显著影响,pH 7.0时普通小球藻对鱼腥藻的竞争抑制参数(β)最大,为12.91;鱼腥藻对普通小球藻的竞争抑制参数(α)则是pH 6.0时最大,为1.778。在4个pH条件下普通小球藻对鱼腥藻的竞争抑制参数(β)均大于鱼腥藻对普通小球藻的竞争抑制参数(α),与单种培养相比,鱼腥藻最大藻细胞数受到明显削弱,说明普通小球藻在竞争中占优势。因此,在水产养殖过程控制和精准培水技术研究,以及控制养殖水体富营养化的过程中,可以通过调节养殖水体pH值以及普通小球藻的浓度来控制鱼腥藻的生长。%Chlorella vulga is a common freshwater algae and Anabaenasp.strain PCC is one of the most common blue-green algae in eutrophication lakes. The pH value is an important physical and chemical indicator of algae growing environment. The growth of algae could be affected by pH value, carbonate balance system and Distribution of inorganic carbon. In

  12. Light Attenuation of Synechocystis sp. PCC 6803 in Photo-bioreactor and Its Growth Dynamics Research%光生物反应器中集胞藻6803的光衰减及其生长动力学研究

    Institute of Scientific and Technical Information of China (English)

    张文婷; 任越; 张英俊; 张志斌

    2010-01-01

    [目的]分析集胞藻6803细胞培养体系的光衰减及分批培养条件下藻细胞的生长特性.[方法]以集胞藻6803(Synechocystis sp. PCC 6803)为供试藻种,用尤尼柯7200型分光光度计测定藻细胞浓度和用ST-85自动量程照度计测定光强在通过不同光程、不同浓度藻液时的变化.[结果]随着藻细胞浓度和光程的增加,光强迅速下降.在同一光程下,光强随着藻细胞浓度的增加而下降.在培养初期藻细胞浓度较低时,光衰减程度较小;在培养后期,随着藻细胞浓度的增加,光衰减程度逐渐增加.在培养过程中藻体细胞的生长规律与微生物发酵过程中菌体的生长规律相似.藻体细胞生物量曲线与微生物发酵时的菌体生长曲线相似.[结论]Lambert-Beer公式Ln(I/I0)=-KaXL能较好描述藻细胞浓度和光程对光衰减的综合影响;Logistic方程能很好描述藻细胞的生长曲线.

  13. 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...

  14. NucA, una nucleasa de baja especifidad de sustrato de las cianobacterias filamentosas formadoras de heterocistos

    OpenAIRE

    Muro Pastor, Alicia María

    1992-01-01

    En este trabajo se aborda la caracterización a nivel molecular de una actividad nucleasa inespecífica presente en las células y el medio extracelular de Anabaena sp. PCC 7120 y Anabaena variabilis ATCC 29413, un aspecto previamente inexplorado de ... la biología de las cianobacterias. Se presenta la clonación del gen nucA de Anabaena sp. PCC 7120, que codifica dicha nucleasa, y la generación, mediante sustitución génica, de estirpes mutantes en este gen derivadas de las estirpes PCC 7120 y AT...

  15. Spectroscopic studies of Synechococcus sp PCC 7002 phycobilisome core mutants

    Energy Technology Data Exchange (ETDEWEB)

    Gindt, Y.M.

    1993-04-01

    The role of the L{sub cm} (I), {beta}{sup 18} (II), and {alpha}{sup AP-B} (III) chromoproteins in the phycobilisome (PBS) core was investigated using genetically engineered strains of Synechococcus missing different polypeptides. Intact cells, isolated PBS, and subcore preparations for each mutant were studied to determine the effect of that mutation on energy transfer within the PBS core and to the reaction centers. Three mutants lacked the II and/or III polypeptides, while the I chromophore was altered in others. A lower energy absorbing chromophore, A{sub max} = 695 nm, was substituted for the I chromophore. The deletion of the II and III subunits had no discernible effect on energy transfer from the PBS to PSII. In cells and isolated PBS, the altered I chromophore acts to quench the PBS complex and to redirect the energy which would be transferred to PSII. In the PBS and subcore preparations, deletion of the III subunit did not alter energy transfer within the core. The deletion of the II subunit from the PBS caused a small decrease in the excited state lifetimes of the final emitters indicating more disorder within the core. The I chromophore was found to absorb at 670nm and to emit at 683nm within the intact PBS. The II chromophore emits at 679nm while the III chromophore emits at 682nm. A strong interaction exists between the I chromophore and the II subunit. Upon deletion of the II subunit from the PBS core, the I chromophore emits at a higher energy. The II subunit could act to stabilize the I chromophore-binding pocket, or exciton coupling could be occurring between the two. The role of the III chromophore is still unclear at this time. The III chromophore does contribute to the RT emission of the isolated PBS, but it transfers energy to I at 77 K. One can conclude that the III subunit is adjacent to the trimer containing the I polypeptide.

  16. Spectroscopic studies of Synechococcus sp PCC 7002 phycobilisome core mutants

    Energy Technology Data Exchange (ETDEWEB)

    Gindt, Y.M.

    1993-04-01

    The role of the L[sub cm] (I), [beta][sup 18] (II), and [alpha][sup AP-B] (III) chromoproteins in the phycobilisome (PBS) core was investigated using genetically engineered strains of Synechococcus missing different polypeptides. Intact cells, isolated PBS, and subcore preparations for each mutant were studied to determine the effect of that mutation on energy transfer within the PBS core and to the reaction centers. Three mutants lacked the II and/or III polypeptides, while the I chromophore was altered in others. A lower energy absorbing chromophore, A[sub max] = 695 nm, was substituted for the I chromophore. The deletion of the II and III subunits had no discernible effect on energy transfer from the PBS to PSII. In cells and isolated PBS, the altered I chromophore acts to quench the PBS complex and to redirect the energy which would be transferred to PSII. In the PBS and subcore preparations, deletion of the III subunit did not alter energy transfer within the core. The deletion of the II subunit from the PBS caused a small decrease in the excited state lifetimes of the final emitters indicating more disorder within the core. The I chromophore was found to absorb at 670nm and to emit at 683nm within the intact PBS. The II chromophore emits at 679nm while the III chromophore emits at 682nm. A strong interaction exists between the I chromophore and the II subunit. Upon deletion of the II subunit from the PBS core, the I chromophore emits at a higher energy. The II subunit could act to stabilize the I chromophore-binding pocket, or exciton coupling could be occurring between the two. The role of the III chromophore is still unclear at this time. The III chromophore does contribute to the RT emission of the isolated PBS, but it transfers energy to I at 77 K. One can conclude that the III subunit is adjacent to the trimer containing the I polypeptide.

  17. Complete genome sequence of Anabaena variabilis ATCC 29413

    Energy Technology Data Exchange (ETDEWEB)

    Thiel, Teresa [University of Missouri, St. Louis; Pratte, Brenda S. [University of Missouri, St. Louis; Zhong, Jinshun [University of Missouri, St. Louis; Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Copeland, A [U.S. Department of Energy, Joint Genome Institute; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Han, Cliff [Los Alamos National Laboratory (LANL); Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute

    2013-01-01

    Anabaena variabilis ATCC 29413 is a filamentous, heterocyst-forming cyanobacterium that has served as a model organism, with an extensive literature extending over 40 years. The strain has three distinct nitrogenases that function under different environmental conditions and is capable of photoautotrophic growth in the light and true heterotrophic growth in the dark using fructose as both carbon and energy source. While this strain was first isolated in 1964 in Mississippi and named Ana-baena flos-aquae MSU A-37, it clusters phylogenetically with cyanobacteria of the genus Nostoc. The strain is a moderate thermophile, growing well at approximately 40 C. Here we provide some additional characteristics of the strain, and an analysis of the complete genome sequence.

  18. 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 ...

  19. AcEST: BP912817 [AcEST

    Lifescience Database Archive (English)

    Full Text Available YMU001_000023_C02 513 Adiantum capillus-veneris mRNA. clone: YMU001_000023_C02. BP912817 - Show ... t sp_hit_id Q06862 Definition sp|Q06862|ACCC_ANASP Biotin ... carboxylase OS=Anabaena sp. (strain PCC 7120) Alig ... cant alignments: (bits) Value sp|Q06862|ACCC_ANASP Biotin ... carboxylase OS=Anabaena sp. (strain ... 245 8e-65 ...

  20. Ethoxyzolamide Inhibition of CO(2)-Dependent Photosynthesis in the Cyanobacterium Synechococcus PCC7942.

    Science.gov (United States)

    Price, G D; Badger, M R

    1989-01-01

    Cells of the cyanobacterium, Synechococcus PCC7942, grown under high inorganic carbon (C(i)) conditions (1% CO(2); pH 8) were found to be photosynthetically dependent on exogenous CO(2). This was judged by the fact that they had a similar photosynthetic affinity for CO(2) (K(0.5)[CO(2)] of 3.4-5.4 micromolar) over the pH range 7 to 9 and that the low photosynthetic affinity for C(i) measured in dense cell suspensions was improved by the addition of exogenous carbonic anhydrase (CA). The CA inhibitor, ethoxyzolamide (EZ), was shown to reduce photosynthetic affinity for CO(2) in high C(i) cells. The addition of 200 micromolar EZ to high C(i) cells increased K(0.5)(CO(2)) from 4.6 micromolar to more than 155 micromolar at pH 8.0, whereas low C(i) cells (grown at 30 microliters CO(2) per liter of air) were less sensitive to EZ. EZ inhibition in high and low C(i) cells was largely relieved by increasing exogenous C(i) up to 100 millimolar. Lipid soluble CA inhibitors such as EZ and chlorazolamide were shown to be the most effective inhibitors of CO(2) usage, whereas water soluble CA inhibitors such as methazolamide and acetazolamide had little or no effect. EZ was found to cause a small drop in photosystem II activity, but this level of inhibition was not sufficient to explain the large effect that EZ had on CO(2) usage. High C(i) cells of Anabaena variabilis M3 and Synechocystis PCC6803 were also found to be sensitive to 200 micromolar EZ. We discuss the possibility that the inhibitory effect of EZ on CO(2) usage in high C(i) cells of Synechococcus PCC7942 may be due to inhibition of a ;CA-like' function associated with the CO(2) utilizing C(i) pump or due to inhibition of an internal CA activity, thus affecting CO(2) supply to ribulose bisphosphate carboxylase-oxygenase. PMID:16666544

  1. PCC/SRC, PCC and SRC Calculation from Multivariate Input for Sensitivity Analysis

    International Nuclear Information System (INIS)

    1 - Description of program or function: PCC/SRC is designed for use in conjunction with sensitivity analyses of complex computer models. PCC/SRC calculates the partial correlation coefficients (PCC) and the standardized regression coefficients (SRC) from the multivariate input to, and output from, a computer model. 2 - Method of solution: PCC/SRC calculates the coefficients on either the original observations or on the ranks of the original observations. These coefficients provide alternative measures of the relative contribution (importance) of each of the various input variables to the observed variations in output. Relationships between the coefficients and differences in their interpretations are identified. If the computer model output has an associated time or spatial history, PCC/SRC will generate a graph of the coefficients over time or space for each input-variable, output- variable combination of interest, indicating the importance of each input value over time or space. 3 - Restrictions on the complexity of the problem - Maxima of: 100 observations, 100 different time steps or intervals between successive dependent variable readings, 50 independent variables (model input), 20 dependent variables (model output). 10 ordered triples specifying intervals between dependent variable readings

  2. Azolla filiculoides Nitrogenase Activity Decrease Induced by Inoculation with Chlamydomonas sp. †

    OpenAIRE

    Habte, Mitiku

    1986-01-01

    Experiments were conducted to determine the influence of Chlamydomonas sp. on nitrogen fixation (C2H2 → C2H4) in Azolla filiculoides and on the nitrogen fixation and growth of free-living Anabaena azollae 2B organisms. Inoculation of azolla medium with Chlamydomonas sp. was associated with decreased nitrogenase activity in A. filiculoides and with increases in the density of a fungal population identified as Acremonium sp. Subsequent inoculation of azolla medium with this fungus was also acco...

  3. Biodegradation of polychlorinated biphenyls (PCBs by the novel identified cyanobacterium Anabaena PD-1.

    Directory of Open Access Journals (Sweden)

    Hangjun Zhang

    Full Text Available Polychlorinated biphenyls (PCBs, a class of hazardous pollutants, are difficult to dissipate in the natural environment. In this study, a cyanobacterial strain Anabaena PD-1 showed good resistance against PCB congeners. Compared to a control group, chlorophyll a content decreased 3.7% and 11.7% when Anabaena PD-1 was exposed to 2 and 5 mg/L PCBs for 7 d. This cyanobacterial strain was capable of decomposing PCB congeners which was conclusively proved by determination of chloride ion concentrations in chlorine-free medium. After 7 d, the chloride ion concentrations in PCB-treated groups (1, 2, 5 mg/L were 3.55, 3.05, and 2.25 mg/L, respectively. The genetic information of strain PD-1 was obtained through 16S rRNA sequencing analysis. The GenBank accession number of 16S rRNA of Anabaena PD-1 was KF201693.1. Phylogenetic tree analysis clearly indicated that Anabaena PD-1 belonged to the genus Anabaena. The degradation half-life of Aroclor 1254 by Anabaena PD-1 was 11.36 d; the total degradation rate for Aroclor 1254 was 84.4% after 25 d. Less chlorinated PCB congeners were more likely to be degraded by Anabaena PD-1 in comparison with highly chlorinated congeners. Meta- and para-chlorines in trichlorodiphenyls and tetrachlorobiphenyls were more susceptible to dechlorination than ortho-chlorines during the PCB-degradation process by Anabaena PD-1. Furthermore, Anabaena PD-1 can decompose dioxin-like PCBs. The percent biodegradation of 12 dioxin-like PCBs by strain PD-1 ranged from 37.4% to 68.4% after 25 days. Results above demonstrate that Anabaena PD-1 is a PCB-degrader with great potential for the in situ bioremediation of PCB-contaminated paddy soils.

  4. Effects of Atmospheric NO2 on Azolla-Anabaena Symbiosis.

    OpenAIRE

    Hur, Jae-Seoun; Wellburn, Alan R.

    1994-01-01

    Cultures of the water fern Azolla pinnata R, Br. exposed for 1 week to atmospheric NO2 (50, 100 or 200 nl l-1) induced additional levels of nitrate reductase (NaR) protein and nitrite reductase (NiR) activity. At low concentrations of NO2 (50 nl l-1), nitrate derived from NO2 provides an alternative N source for Azolla but does not affect rates of acetylene reduction. However, the symbiotic relationship between Azolla and its endosymbiont, Anabaena azollae is only affected adversely by high c...

  5. 光照对普通小球藻和鱼腥藻生长竞争的影响%Effect of Light Intensity on Growth and Competition between Chlorella Vulgaris and Anabaena

    Institute of Scientific and Technical Information of China (English)

    孟顺龙; 邴旭文; 裘丽萍; 王菁; 胡庚东; 瞿建宏; 范立民; 宋超; 吴伟; 陈家长

    2015-01-01

    Chlorella vulgaris and Anabaena sp. are the most common algae in eutrophication ponds. In order to know the growth process of the two species of algae in eutrophication ponds and the relationship between algae growth and light intensity, the experiment was carried out to research the interspecies competition between Chlorella vulgaris and Anabaena sp. at different light intensity (660, 2 200, 4 400, 6 600 lx) by the methods of special growth rate, growth curve and inhibition parameters through indoors experiment. For the experiment could help clarify how to promote the growth of useful algae and restrain the growth of harmful algae by the way of regulating the environment factors, so the study is very important for regulating aquaculture eco-environment and improving primary productivity of water body. The results indicated that maximum biomass of both Chlorella vulgaris and Anabaena sp. increased with the increase of light intensity in the uni-culture system, and the maximum biomass of Chlorella vulgaris in the light intensity of 660, 2200, 4 400, 6 600 lx were 961.2×104, 1 858.3×104, 3 258.8×104, 3 227.2×104 cells·mL-1 respectively, and the maximum biomass of Anabaena sp. in the light intensity of 660, 2 200, 4 400, 6600 lx were 4 018.3×104, 8 325.0×104, 10 552.8×104, 10 073.4×104 cells·mL-1 respectively. Light intensity could influence the competition between Chlorella vulgaris and Anabaena sp. significantly. The results of inhibition parameter of interspecies competition showed that the inhibition parameters of Anabaena sp. against Chlorella vulgaris were all lower than that of Chlorella vulgaris against Anabaena sp. at the experiment condition. The inhibition parameter of Chlorella vulgaris against Anabaena sp. reached the peak at the 6 600 lx group, and the maximum was 7.94. The inhibition parameter of Anabaena sp. against Chlorella vulgaris reached the peak at the 4 400 lx group, and the maximum was 0.45. Chlorella vulgaris dominated in the 2 200

  6. BIODEGRADATION OF TEXTILE DYES BY Anabaena flos-aqual

    Directory of Open Access Journals (Sweden)

    Brigida Pimentel Villar de Queiroz

    2011-04-01

    Full Text Available The pollution caused by dumping of toxic waste into the environment has resulted in impairment of essential natural resources such as water. With population growth and industries, the generation of waste increases substantially. Specifically, about 3,000 were commercial dyes to be carcinogenic and have no longer been manufactured, but in third world countries such as Brazil, some of these dyes high commercial value, are still in use. This study aimed to evaluate the possibility of biodegradation of dyes technical Drim CL 2 R Yellow and Blue Drim CL R. We tested the ability of degradation of these dyes by the cyanobacteria blue-green algae Anabaena flos-aqual. For this, their effectiveness in the degradation was evaluated in terms of discoloration spectrophotometrically. The blue dye was greater than R Drim CL degradation rate compared to the yellow dye Drim CL 2R. The species Anabaena flos-aqual achieved high degradation efficiency compared to blue dye, revealing a high potential applicability in processes of textile biodegradations in the county of Americana.

  7. Azolla-Anabaena relationship. XIII. Fixation of (/sup 13/N)N/sub 2/. [Azolla caroliniana; Anabaena azollae

    Energy Technology Data Exchange (ETDEWEB)

    Meeks, J.C.; Steinberg, N.A.; Enderlin, C.S.; Joseph, C.M.; Peters, G.A.

    1987-07-01

    The major radioactive products of the fixation of (/sup 13/N)N/sub 2/ by Azolla caroliniana willd.-Anabaena azollae Stras. were ammonium, glutamine, and glutamate, plus a small amount of alanine. Ammonium accounted for 70 and 32% of the total radioactivity recovered after fixation for 1 and 10 minutes, respectively. The presence of a substantial pool of (/sup 13/N)N/sub 2/-derived /sup 13/NH/sub 4//sup +/ after long incubation periods was attributed to the spatial separation between the site of N/sub 2/-fixation (Anabaena) and a second, major site of assimilation (Azolla). Initially, glutamine was the most highly radioactive organic product formed from (/sup 13/N)N/sub 2/, but after 10 minutes of fixation glutamate had 1.5 times more radiolabel than glutamine. These kinetics of radiolabeling, along with the effects of inhibitors of glutamine synthetase and glutamate synthase on assimilation of exogenous and (/sup 13/N)N/sub 2/-derived /sup 13/NH/sub 4//sup +/, indicate that ammonium assimilation occurred by the glutamate synthase cycle and that glutamate dehydrogenase played little or no role in the synthesis of glutamate by Azolla-Azabaena.

  8. A novel potassium deficiency-induced stimulon in Anabaena torulosa

    Indian Academy of Sciences (India)

    Anuradha Alahari; Shree Kumar Apte

    2004-06-01

    Potassium deficiency enhanced the synthesis of fifteen proteins in the nitrogen-fixing cyanobacterium Anabaena torulosa and of nine proteins in Escherichia coli. These were termed potassium deficiency-induced proteins or PDPs and constitute hitherto unknown potassium deficiency–induced stimulons. Potassium deficiency also enhanced the synthesis of certain osmotic stress-induced proteins. Addition of K+ repressed the synthesis of a majority of the osmotic stress-induced proteins and of PDPs in these bacteria. These proteins contrast with the dinitrogenase reductase of A. torulosa and the glycine betaine-binding protein of E. coli, both of which were osmo-induced to a higher level in potassium-supplemented conditions. The data demonstrate the occurrence of novel potassium deficiency-induced stimulons and a wider role of K+ in regulation of gene expression and stress responses in bacteria.

  9. UV-inducible DNA repair in the cyanobacteria Anabaena spp

    International Nuclear Information System (INIS)

    Strains of the filamentous cyanobacteria Anabaena spp. were capable of very efficient photoreactivation of UV irradiation-induced damage to DNA. Cells were resistant to several hundred joules of UV irradiation per square meter under conditions that allowed photoreactivation, and they also photoreactivated UV-damaged cyanophage efficiently. Reactivation of UV-irradiated cyanophage (Weigle reactivation) also occurred; UV irradiation of host cells greatly enhanced the plaque-forming ability of irradiated phage under nonphotoreactivating conditions. Postirradiation incubation of the host cells under conditions that allowed photoreactivation abolished the ability of the cells to perform Weigle reactivation of cyanophage N-1. Mitomycin C also induced Weigle reactivation of cyanophage N-1, but nalidixic acid did not. The inducible repair system (defined as the ability to perform Weigle reactivation of cyanophages) was relatively slow and inefficient compared with photoreactivation

  10. 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

  11. Photoreactions and Structural Changes of Anabaena Sensory Rhodopsin

    Directory of Open Access Journals (Sweden)

    Akira Kawanabe

    2009-12-01

    Full Text Available Anabaena sensory rhodopsin (ASR is an archaeal-type rhodopsin found in eubacteria. The gene encoding ASR forms a single operon with ASRT (ASR transducer which is a 14 kDa soluble protein, suggesting that ASR functions as a photochromic sensor by activating the soluble transducer. This article reviews the detailed photoreaction processes of ASR, which were studied by low-temperature Fourier-transform infrared (FTIR and UV-visible spectroscopy. The former research reveals that the retinal isomerization is similar to bacteriorhodopsin (BR, but the hydrogen-bonding network around the Schiff base and cytoplasmic region is different. The latter study shows the stable photoproduct of the all-trans form is 100% 13-cis, and that of the 13-cis form is 100% all-trans. These results suggest that the structural changes of ASR in the cytoplasmic domain play important roles in the activation of the transducer protein, and photochromic reaction is optimized for its sensor function.

  12. The effects of SO sub 2 on Azolla - Anabaena symbiosis

    Energy Technology Data Exchange (ETDEWEB)

    Jaeseoun Hur; Wellburn, A.R. (Lancaster Univ. (United Kingdom))

    1991-05-01

    Cultures of Azolla pinnata containing Anabaena were investigated as a sensitive and reproducible bioindicator of air pollution. Three equal doses of SO{sub 2} (week*ppb: 1*100, 2*50, 4*25) were applied to Azolla cultures growing in nitrogen-free medium in a specially-designed exposure system. Exposure to high concentrations of SO{sub 2} showed highly significant reductions in growth of the fern, while nitrogen fixation and heterocyst development were severely damaged. This was associated with a reduction of protein content in the SO{sub 2}-exposed ferns and again more significant at higher SO{sub 2} levels. There was a variation in the absolute amount of the individual pigments between SO{sub 2} doses and/or treatments which was related to the physiological development of the ferns throughout the fumigations. Moreover, the ratio of violaxanthin to antheraxanthin in the 100 ppb SO{sub 2}-treated ferns was significantly higher than that in the clean air-grown ferns. The results clearly demonstrate that SO{sub 2} has adverse effects on the symbiosis and suggest that this fern is a promising bioindicator of air pollution and a very good model to investigate the inter-relationships between photosynthesis, nitrogen fixation and air pollution stress.

  13. Precipitated calcium carbonate (PCC - cellulose composite fillers: Effects of PCC particle structure on the production and properties of uncoated fine paper

    Directory of Open Access Journals (Sweden)

    Paulapuro, H.

    2007-02-01

    Full Text Available This work examines the precipitation of PCC – pulp composite fillers with varying crystal habits and their effects on the papermaking properties of printing and writing paper. Colloidal (c-PCC, rhombohedral (r-PCC, and scalenohedral types (s-PCC of composite PCCs were produced and compared with commercial reference PCCs. Scanning electron micros-copy showed the c-PCC to be a high-surface-area nano-structured PCC. The rhombohedral composite was formed in clusters like a spider-web structure. Under similar experimental conditions, composite PCC was formed as individual ellipsoidal crystals and some of the particles had malformed structure, in contrast to the structured reference s-PCC. The co-precipitation and the structure of PCC significantly influence the forming, consolidation, and properties of paper, as well as its perform-ance in printing.Composite c-PCC showed the highest retention during forming. At higher filler contents, dewatering was reduced significantly with handsheets containing s- and r-PCC composite fillers. Colloidal composite hand-sheets showed the lowest tensile index and internal bond strength, while the rhombohedral composite gave the highest z-directional bond strength. Compared with the traditional reference samples containing commercial PCCs, paper with s- and r-composites had significantly higher density but similar light scattering ability. Addition of fibrillar fines to fine paper increased print rub fastness significantly in both laser and inkjet printed samples.

  14. Mecanismos de tolerancia del simbiosistema Azolla-Anabaena azollae ante arsénico y cobre.

    OpenAIRE

    Sánchez Viveros, Gabriela

    2012-01-01

    Esta investigación evaluó algunos mecanismos de tolerancia del simbiosistema Azolla-Anabaena azollae ante agua contaminada con arsénico (As+5) y/o cobre (Cu2+). Para lo anterior, se plantearon seis fases experimentales: 1) identificar molecularmente a nivel de especie a diez colectas de Azolla, 2) evaluar la capacidad de acumulación de As+5 y los efectos tóxicos del metaloide en el simbiosistema Azolla-Anabaena azollae, 3) determinar la influencia del As+5 en la concentración de nueve element...

  15. An ecophysiological study of the Azolla filiculoides- Anabaena azollae association

    Science.gov (United States)

    van Kempen, Monique; Smolders, Fons; Speelman, Eveline; Reichart, Gert Jan; Barke, Judith; Brinkhuis, Henk; Lotter, Andy; Roelofs, Jan

    2010-05-01

    The long term effects of salinity stress on the growth, nutrient content and amino acid composition of the Azolla filiculoides - Anabaena azollae association was studied in a laboratory experiment. It was demonstrated that the symbiosis could tolerate salt stress up to 90 mM NaCl, even after a 100 day period of preconditioning at salt concentrations that were 30 mM NaCl lower. In the 120 mM NaCl treatment the Azolla filiculoides survived, but hardly any new biomass was produced. It was shown that during the experiment, A. filiculoides became increasingly efficient in excluding salt ions from the plant tissue and was thus able to increase its salt tolerance. The amino acid analysis revealed that the naturally occurring high glutamine concentration in the plants was strongly reduced at salt concentrations of 120 mM NaCl and higher. This was the result of the reduced nitrogenase activity at these salt concentrations, as was demonstrated in an acetylene reduction assay. We suggest that the high glutamine concentration in the plants might play a role in the osmoregulatory response against salt stress, enabling growth of the A. filiculoides -Anabaena azollae association up to 90 mM NaCl. In a mesocosm experiment it furthermore was demonstrated that Azolla might manipulate its own microenvironment when grown at elevated salt concentration (up to ~50 mmol•L-1) by promoting salinity stratification, especially when it has formed a dense cover at the water surface. Beside salt stress, we also studied the growth of Azolla filiculoides in response to elevated atmospheric carbon dioxide concentration, in combination with different light intensities and different pH of the nutrient solution. The results demonstrated that as compared to the control (ambient pCO2 concentrations), Azolla filiculoides was able to produce twice as much biomass at carbon dioxide concentrations that were five times as high as the ambient pCO2 concentration. However, it was also shown that this

  16. BIOTRANSFORMATION OF 2,4,6-TRINITROTOLUENE (TNT) IN ANABAENA SP. CULTURES. (R825513C013)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  17. Anabaena bergii Ostenf. [f. minor (Kisselev Kossinsk.] (Cyanoprokaryota: The first record in Serbia, its taxonomic status, and that of the genus Anabaena Bory ex Born. & Flah.

    Directory of Open Access Journals (Sweden)

    Cvijan M.

    2009-01-01

    Full Text Available Within the framework of a detailed survey of the algal community in salt marshes of the Vojvodina Province (Northern Serbia, we rather unexpectedly found the blue-green alga Anabaena bergii Ostenf. [forma minor (Kisselev Kossinsk.] in water samples from Slatina Pond near Opovo. Our finding represents its first record in Serbia. The present paper gives general characteristics of this alga and of the habitat in which it was found. Based on analysis of a large number of works dealing with characteristics and the taxonomic status of the genus Anabaena, the species A. bergii, and its forma minor, it is concluded that there are numerous problems in taxonomy of the given genus, with no consensus among researchers. In light of the available data, the authors retain the name of the species A. bergii, but accept forma minor with some reserve.

  18. STARCH-SODIUM STEARATE COMPLEX MODIFIED PCC FILLER AND ITS APPLICATION IN PAPERMAKING

    Directory of Open Access Journals (Sweden)

    Huiming Fan,

    2012-06-01

    Full Text Available The use of fillers tends to reduce paper strength, which can limit their application. Therefore research on filler modification is of significant importance in order to overcome this limitation. In this paper, precipitated calcium carbonate (PCC was modified by starch, sodium stearate, and the starch cross-linking agent sodium hexametaphosphate. The purpose of this research is to provide useful references to the industrial application of modified precipitated calcium carbonate (PCC. Modified precipitated calcium carbonate (PCC was characterized by particle size analyzer and scanning electron microscope (SEM. The analysis showed that the particle size of the modified PCC was significantly increased versus the control. The morphology of modified PCC also greatly changed. The influence of modified and unmodified PCC filled paper on paper physical performance was studied. The experimental results showed that at the same ash content, modified PCC filled paper compared with unmodified PCC filled paper had higher brightness, lower opacity, and higher physical strength. The impact of modified and unmodified PCC on stock retention and the comparison between modified and unmodified PCC were investigated. The experimental results showed that the stock filled with modified PCC had better retention compared to those filled with unmodified PCC.

  19. Anabaena bergii Ostenf. [f. minor (Kisselev) Kossinsk.] (Cyanoprokaryota): The first record in Serbia, its taxonomic status, and that of the genus Anabaena Bory ex Born. & Flah.

    OpenAIRE

    Cvijan M.; Krizmanić Jelena

    2009-01-01

    Within the framework of a detailed survey of the algal community in salt marshes of the Vojvodina Province (Northern Serbia), we rather unexpectedly found the blue-green alga Anabaena bergii Ostenf. [forma minor (Kisselev) Kossinsk.] in water samples from Slatina Pond near Opovo. Our finding represents its first record in Serbia. The present paper gives general characteristics of this alga and of the habitat in which it was found. Based on analysis of a large number of works dealing with char...

  20. Transfected parvalbumin alters calcium homeostasis in teratocarcinoma PCC7 cells

    DEFF Research Database (Denmark)

    Müller, B K; Kabos, P; Belhage, B;

    1996-01-01

    transfected. Parvalbumin-transfected and mock-transfected cells were loaded with the calcium indicator fura-2 and were exposed, in the same dish, to different concentrations of the calcium ionophore A23187 or to KCI. The results show that parvalbumin-transfected PCC7 cells had much better calcium buffering...

  1. Towards PCC for Concurrent and Distributed Systems (Work in Progress)

    Science.gov (United States)

    Henriksen, Anders S.; Filinski, Andrzej

    2009-01-01

    We outline some conceptual challenges in extending the PCC paradigm to a concurrent and distributed setting, and sketch a generalized notion of module correctness based on viewing communication contracts as economic games. The model supports compositional reasoning about modular systems and is meant to apply not only to certification of executable code, but also of organizational workflows.

  2. Transfected parvalbumin alters calcium homeostasis in teratocarcinoma PCC7 cells

    DEFF Research Database (Denmark)

    Müller, B K; Kabos, P; Belhage, B;

    1996-01-01

    Indirect evidence supports a protective role of some EF-hand calcium-binding proteins against calcium-induced neurotoxicity. Little is known about how these proteins influence cytosolic calcium levels. After cloning the parvalbumin cDNA into an expression vector, teratocarcinoma cells (PCC7) were...

  3. GC/MS analysis of piperidinocyclohexanecarbonitrile (PCC) smoking products

    International Nuclear Information System (INIS)

    Piperidinocyclohexanecarbonitrile (PCC), an intermediate in phencyclidine (PCP) synthesis, is a major contaminant of illicit PCP. Due to the frequent abuse of PCP by smoking, this study was conducted to determine the PCC pyrolysis products delivered in smoke. Marihuana placebo cigarettes were impregnated with 3H-piperidino-14C-cyano-PCC (synthesized in the lab and recrystallized twice, m.p. 670C) and burned under conditions which simulated smoking. Mainstream smoke was passed through glass wool filters and H2SO4 and NaOH traps. Tritium and 14C were recovered as 83%, and 56%, respectively, of the starting material. Seventy-six percent of the recovered tritium was found in the glass wool trap followed by 13, 7 and 4% in the acid trap, base trap and in the ash/unburned butt, respectively. Seventy-three percent of the recovered 14C was found in the glass wool filter and 16 and 8% were found in the acid and base traps, respectively. GC/MS analysis revealed the presence of 1-piperidinocyclohexene (30%), PCC (24%), piperidine (7%), and 1-acetyl-piperidine (5%)

  4. GC/MS analysis of piperidinocyclohexanecarbonitrile (PCC) smoking products

    Energy Technology Data Exchange (ETDEWEB)

    Lue, L.P.; Scimeca, J.A.; Thomas, B.F.; Martin, B.R.

    1986-03-05

    Piperidinocyclohexanecarbonitrile (PCC), an intermediate in phencyclidine (PCP) synthesis, is a major contaminant of illicit PCP. Due to the frequent abuse of PCP by smoking, this study was conducted to determine the PCC pyrolysis products delivered in smoke. Marihuana placebo cigarettes were impregnated with /sup 3/H-piperidino-/sup 14/C-cyano-PCC (synthesized in the lab and recrystallized twice, m.p. 67/sup 0/C) and burned under conditions which simulated smoking. Mainstream smoke was passed through glass wool filters and H/sub 2/SO/sub 4/ and NaOH traps. Tritium and /sup 14/C were recovered as 83%, and 56%, respectively, of the starting material. Seventy-six percent of the recovered tritium was found in the glass wool trap followed by 13, 7 and 4% in the acid trap, base trap and in the ash/unburned butt, respectively. Seventy-three percent of the recovered /sup 14/C was found in the glass wool filter and 16 and 8% were found in the acid and base traps, respectively. GC/MS analysis revealed the presence of 1-piperidinocyclohexene (30%), PCC (24%), piperidine (7%), and 1-acetyl-piperidine (5%).

  5. Classification and phylogeny of the cyanobiont Anabaena azollae Strasburger: an answered question?

    Science.gov (United States)

    Pereira, Ana L; Vasconcelos, Vitor

    2014-06-01

    The symbiosis Azolla-Anabaena azollae, with a worldwide distribution in pantropical and temperate regions, is one of the most studied, because of its potential application as a biofertilizer, especially in rice fields, but also as an animal food and in phytoremediation. The cyanobiont is a filamentous, heterocystic cyanobacterium that inhabits the foliar cavities of the pteridophyte and the indusium on the megasporocarp (female reproductive structure). The classification and phylogeny of the cyanobiont is very controversial: from its morphology, it has been named Nostoc azollae, Anabaena azollae, Anabaena variabilis status azollae and recently Trichormus azollae, but, from its 16S rRNA gene sequence, it has been assigned to Nostoc and/or Anabaena, and from its phycocyanin gene sequence, it has been assigned as non-Nostoc and non-Anabaena. The literature also points to a possible co-evolution between the cyanobiont and the Azolla host, since dendrograms and phylogenetic trees of fatty acids, short tandemly repeated repetitive (STRR) analysis and restriction fragment length polymorphism (RFLP) analysis of nif genes and the 16S rRNA gene give a two-cluster association that matches the two-section ranking of the host (Azolla). Another controversy surrounds the possible existence of more than one genus or more than one species strain. The use of freshly isolated or cultured cyanobionts is an additional problem, since their morphology and protein profiles are different. This review gives an overview of how morphological, chemical and genetic analyses influence the classification and phylogeny of the cyanobiont and future research. PMID:24737795

  6. Polyphasic characterization of three strains of .i.Anabaena reniformis./i. and .i.Aphanizomenon aphanizomenoides./i. (cyanobacteria) and their re-classification to .i.Sphaerospermum./i. gen. nov. (incl. .i.Anabaena kisseleviana./i.)

    Czech Academy of Sciences Publication Activity Database

    Zapomělová, Eliška; Jezberová, Jitka; Hrouzek, Pavel; Hisem, D.; Řeháková, Klára; Komárková, Jaroslava

    2009-01-01

    Roč. 45, č. 6 (2009), s. 1363-1373. ISSN 0022-3646 R&D Projects: GA AV ČR(CZ) KJB600960703; GA AV ČR(CZ) IAA600050704; GA ČR(CZ) GA206/06/0462 Institutional research plan: CEZ:AV0Z60170517; CEZ:AV0Z50200510 Keywords : Anabaena reniformis * Aphanizomenon aphanizomenoides * taxonomy * Sphaerospermum * Anabaena kisseleviana Subject RIV: EE - Microbiology, Virology Impact factor: 2.270, year: 2009

  7. Polyphasic characterization of eight planktonic .i.Anabaena./i. strains (Cyanobacteria) with reference to the variability of 61 .i.Anabaena./i. populations observed in the field

    Czech Academy of Sciences Publication Activity Database

    Zapomělová, Eliška; Řeháková, Klára; Jezberová, Jitka; Komárková, Jaroslava

    2010-01-01

    Roč. 639, č. 1 (2010), s. 99-113. ISSN 0018-8158. [IAP /15./. Golan Heights, 23.11.2008-30.11.2008] R&D Projects: GA AV ČR(CZ) KJB600960703; GA ČR(CZ) GA206/06/0462; GA AV ČR(CZ) IAA600050704 Institutional research plan: CEZ:AV0Z60170517 Keywords : Anabaena * taxonomy * morphology * classification * light * nitrogen * phosphorus Subject RIV: EE - Microbiology, Virology Impact factor: 1.964, year: 2010

  8. Identifying Fine Aggregates Prone to Polishing in PCC Pavements

    OpenAIRE

    Fowler, David W; Rached, Marc M.

    2012-01-01

    Surface polishing in portland cement concrete (PCC) pavements leads to higher incidences of skid-related accidents on highways. This type of failure is often associated with the usage of softer fine aggregate such as limestone sands. To identify polish resistance aggregates, state agencies like TxDOT have adopted tests such as the acid insoluble residue test (AIR). Since calcium carbonate is soluble in acid, no carbonate sand passes the AIR test which has a minimum limit of 60% in Texas. This...

  9. Morphological and ultrastructural changes in vegetative cells and heterocysts of Anabaena variabilis grown with fructose.

    OpenAIRE

    Lang, N. J.; Krupp, J M; Koller, A L

    1987-01-01

    The morphology and ultrastructure of Anabaena variabilis grown in medium with and without 40 mM fructose were compared. Vegetative cells and young heterocysts in fructose-supplemented medium were significantly larger, were filled with glycogen granules, and had fewer thylakoids. Developing heterocysts contained large numbers of glycogen granules well into mature stages, and envelope formation was precocious. As heterocysts enlarged in fructose medium, their shape became more broadly oblong co...

  10. Whole Cell Biosensor Using Anabaena torulosa with Optical Transduction for Environmental Toxicity Evaluation

    OpenAIRE

    Ling Shing Wong; Yook Heng Lee; Salmijah Surif

    2013-01-01

    A whole cell-based biosensor using Anabaena torulosa for the detection of heavy metals (Cu, Pb, and Cd), 2,4-dichlorophenoxyacetate (2,4-D), and chlorpyrifos was constructed. The cyanobacteria were entrapped on a cellulose membrane through filtration. Then, the membrane was dried and fixed into a cylindrical well, which was designed to be attached to an optical probe. The probe was connected to fluorescence spectrometer with optical fibre. The presence of the toxicants was indicated by the ch...

  11. Acyl-acyl carrier protein: Lysomonogalactosyldiacylglycerol acyl transferase in Anabaena variabilis

    International Nuclear Information System (INIS)

    Monogalactosyldiacylglycerol was produced when membranes isolated from the cyanobacterium, Anabaena variabilis, and washed free of soluble endogenous constituents, were incubated with (14C)acyl-acyl carrier protein. This enzymatic synthesis of monogalactosyldiacylglycerol localized in the membranes was not dependent on any added cofactors, such as ATP, coenzyme A, and dithiothreitol. Palmitoyl-, stearoyl-, and oleoyl-acyl carrier proteins were approximately equally active as substrates with Km of 0.37, 0.36, and 0.23 μM, respectively. The (14C)acyl group was exclusively transferred to the sn-1 hydroxyl of the glycerol backbone of monogalactosyldiacylglycerol as demonstrated by hydrolysis of all incorporated acyl groups by the lipase from Rhizopus arrhizus delamar. Using a double labelled (14C)acyl-(14C)acyl carrier protein, this enzyme catalyzed the direct transfer of the acyl group from acyl-acyl carrier protein to an endogenous lysomonogalactosyldiacylglycerol to form monogalactosyldiacylglycerol. The transfer reaction mechanism was also confirmed by the increased activity with the addition of the lysomonogalactosyldiacylglycerol suspension. A specific galactolipid acyl hydrolase activity was released into the soluble protein fraction when the membranes of Anabaena variabilis were treated with 2% Triton X-100. The positional specificity of this acyl hydrolase was demonstrated to be similar to that of Rhizopus lipase, i.e. only the acyl group at the sn-1 position was hydrolyzed. The acyl hydrolase which was also localized in the membrane fraction of Anabaena variabilis was presumably responsible for producing endogenous lysomonogalactosyldiacylglycerol used by the acyltransferase

  12. Effect of the cyanobacterium Anabaena spiroides Klebahn on the quantity of bacterioplankton in water of varied trophicity.

    Science.gov (United States)

    Czeczuga, B; Chomutowska, H

    2000-01-01

    The authors investigated the effect of the cyanobacterium Anabaena spiroides on the quantity of bacterioplankton in water of varied trophicity. The cyanobacterium Anabaena spiroides, introduced to the polluted water of the river Biała has the strongest effect on bacterioplankton--the number of bacteria decreases to 31.78%. The spherical:cylindrical ratio changes in favour of the latter when affected by the cyanobacterium. This is the most pronounced in the river Biała, where spherical:cylindrical changes from 1:0.88 to 1:1.96. Anabaena spiroides exerts the most significant effect on the quantity of bacterioplankton in lake Sniardwy and pond Fosa after 24 hours, and in the other water bodies after 72 hours following the introduction of the cyanobacterium. PMID:11712443

  13. Biosorption of cadmium and lead from aqueous solution by fresh water alga Anabaena sphaerica biomass

    OpenAIRE

    Abdel -Aty, Azza M.; Ammar, Nabila S.; Hany H. Abdel Ghafar; Ali, Rizka K.

    2013-01-01

    The present work represents the biosorption of Cd(II) and Pb(II) from aqueous solution onto the biomass of the blue green alga Anabaena sphaerica as a function of pH, biosorbent dosage, contact time, and initial metal ion concentrations. Freundlich, Langmuir, and Dubinin–Radushkevich (D–R) models were applied to describe the biosorption isotherm of both metals by A. sphaerica biomass. The biosorption isotherms studies indicated that the biosorption of Cd(II) and Pb(II) follows the Langmuir an...

  14. Fructose uptake and influence on growth of and nitrogen fixation by Anabaena variabilis.

    OpenAIRE

    Haury, J F; Spiller, H.

    1981-01-01

    Fructose is specifically taken up by nitrogen-fixing cultures of Anabaena variabilis in the light and lowers the doubling time from 24 to 8 h. The kinetics for both fructose-dependent growth and fructose uptake are exponential. The apparent Km for fructose uptake in N2-fixing cultures is 160 microM for cells not previously exposed to fructose and 50 microM in cells adapted to fructose. Picomolar amounts of [14C]fructose are scavenged from the medium and accumulate in filaments. Heterocysts of...

  15. Purification and partial characterization of a calcium-stimulated protease from the cyanobacterium, Anabaena variabilis.

    Science.gov (United States)

    Lockau, W; Massalsky, B; Dirmeier, A

    1988-03-01

    A calcium-stimulated protease was purified to apparent homogeneity from the heterocyst-forming cyanobacterium Anabaena variabilis ATCC 29413. As judged from experiments with inhibitors and chromogenic peptide substrates, the enzyme is a serine protease with a substrate specificity like trypsin. Its apparent relative molecular mass is 52,000. Calcium depletion inhibits the enzymic activity by 92%. Half-maximal activity requires about 0.5 microM free Ca2+. The enzyme binds to a hydrophobic column in a calcium-dependent manner, indicating calcium-induced exposure of a hydrophobic domain. The possible role of the protease in heterocyst differentiation is discussed. PMID:3127208

  16. 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

  17. 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

    2015-07-01

    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.

  18. Protein network signatures associated with exogenous biofuels treatments in cyanobacterium Synechocystis sp. PCC 6803

    Directory of Open Access Journals (Sweden)

    Guangsheng ePei

    2014-11-01

    Full Text Available 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 needs 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 (PPI 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 WGCNA 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.

  19. 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

  20. Protein network signatures associated with exogenous biofuels treatments in cyanobacterium Synechocystis sp. PCC 6803

    OpenAIRE

    Guangsheng ePei; Lei eChen; Jiangxin eWang; jianjun eQiao; Weiwen eZhang

    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 needs 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...

  1. Estudio funcional de la ribonucleasa P de la cianobacteria Synechocystis sp. PCC 6803

    OpenAIRE

    Pascual, Alberto

    1998-01-01

    Los RNA transferentes se sintetizan como precursores y deben ser madurados post-transcripcionalmente a RNA transferentes maduros. La maduración del extremo 5' de los RNAs transferentes la realiza la ribonucleasa P (RNasa P). La RNasa P bacteriana posee dos subunidades, una RNA y otra proteína. El RNA cataliza la reacción en ausencia de proteínas en determinadas condiciones in vitro. En esta tesis se ha estudiado la RNasa P de cianobacterias. Se ha clonado el gen codificante del componente RNA...

  2. Estudio de las glutamato sintasas de la cianobacteria Synechocystis sp. PCC 6803

    OpenAIRE

    Navarro Gómez, Francisco

    1996-01-01

    El objetivo de este trabajo fue, en principio, la caracterización del gen de la Fd-GOGAT de Synechocystis 6803, así como de la proteína correspondiente y el análisis de mutantes del mismo. El descubrimiento de dos enzimas con actividad glutamato sintasa en esta cianobacteria, llevó a un estudio de los genes correspondientes y a un análisis comparativo de los mismos, entre sí y con el resto de secuencias de glutamato sintasas disponibles. La obtención de mutantes simples de cada gen y de mut...

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

    OpenAIRE

    Knoop, Henning; Gründel, Marianne; Zilliges, Yvonne; Lehmann, Robert; Hoffmann, Sabrina; Lockau, Wolfgang; Steuer, Ralf

    2013-01-01

    Cyanobacteria are versatile unicellular phototrophic microorganisms that are highly abundant in many environments. Owing to their capability to utilize solar energy and atmospheric carbon dioxide for growth, cyanobacteria are increasingly recognized as a prolific resource for the synthesis of valuable chemicals and various biofuels. To fully harness the metabolic capabilities of cyanobacteria necessitates an in-depth understanding of the metabolic interconversions taking place during phototro...

  4. The Anabaena sensory rhodopsin transducer defines a novel superfamily of prokaryotic small-molecule binding domains

    Directory of Open Access Journals (Sweden)

    De Souza Robson F

    2009-08-01

    Full Text Available Abstract The Anabaena sensory rhodopsin transducer (ASRT is a small protein that has been claimed to function as a signaling molecule downstream of the cyanobacterial sensory rhodopsin. However, orthologs of ASRT have been detected in several bacteria that lack rhodopsin, raising questions about the generality of this function. Using sequence profile searches we show that ASRT defines a novel superfamily of β-sandwich fold domains. Through contextual inference based on domain architectures and predicted operons and structural analysis we present strong evidence that these domains bind small molecules, most probably sugars. We propose that the intracellular versions like ASRT probably participate as sensors that regulate a diverse range of sugar metabolism operons or even the light sensory behavior in Anabaena by binding sugars or related metabolites. We also show that one of the extracellular versions define a predicted sugar-binding structure in a novel cell-surface lipoprotein found across actinobacteria, including several pathogens such as Tropheryma, Actinomyces and Thermobifida. The analysis of this superfamily also provides new data to investigate the evolution of carbohydrate binding modes in β-sandwich domains with very different topologies. Reviewers: This article was reviewed by M. Madan Babu and Mark A. Ragan.

  5. Effects of lead accumulation on the Azolla caroliniana-Anabaena association.

    Science.gov (United States)

    Roberts, Anne E; Boylen, Charles W; Nierzwicki-Bauer, Sandra A

    2014-04-01

    The effect of lead accumulation on photopigment production, mineral nutrition, and Anabaena vegetative cell size and heterocyst formation in Azolla caroliniana was investigated. Plants were exposed to 0, 1, 5, 10, and 20 mg L(-1) lead acetate for ten days. Lead accumulation increased when plants were treated with higher lead concentrations. Results revealed a statistically significant decline in total chlorophyll, chlorophyll a, chlorophyll b, and carotenoids in 5, 10, and 20 mg Pb L(-1) treatment groups as compared to plants with 0 or 1 mg Pb L(-1) treatments. No statistically significant change in anthocyanin production was observed. Calcium, magnesium, and zinc concentrations in plants decreased in increasing treatment groups, whereas sodium and potassium concentrations increased. Nitrogen and carbon were also found to decrease in plant tissue. Anabaena vegetative cells decreased in size and heterocyst frequency declined rapidly in a Pb dose-dependent manner. These results indicate that, while A. caroliniana removes lead from aqueous solution, the heavy metal causes physiological and biochemical changes by impairing photosynthesis, changing mineral nutrition, and impeding the growth and formation of heterocysts of the symbiotic cyanobacteria that live within leaf cavities of the fronds. PMID:24509077

  6. Ellman’s reagent in promoting crystallization and structure determination of Anabaena CcbP

    International Nuclear Information System (INIS)

    Ellman’s reagent oxidized the free sulfhydryl group of cysteine in Anabaena CcbP protein, facilitating its crystallization. Obtaining crystals presented a bottleneck in the structural study of Anabaena cyanobacterial Ca2+-binding protein (CcbP). In this report, the promoting effect of Ellman’s reagent [5,5′-dithiobis(2-nitrobenzoic acid); DTNB] on the crystallization of CcbP is described. CcbP contains one free cysteine. A quick and simple oxidation reaction with DTNB blocked the free cysteine in purified CcbP and generated a homogenous monomeric protein for crystallization. The crystal structure of DTNB-modified CcbP was determined by the single-wavelength anomalous diffraction method. Structure analysis indicated that DTNB modification facilitated crystallization of CcbP by inducing polar interactions in the crystal lattice. DTNB-mediated cysteine modification was demonstrated to have little effect on the overall structure and the Ca2+ binding of CcbP. Thus, DTNB modification may provide a simple and general approach for protein modification to improve the success of crystallization screening

  7. Energy transfer in Anabaena variabilis filaments under nitrogen depletion, studied by time-resolved fluorescence.

    Science.gov (United States)

    Onishi, Aya; Aikawa, Shimpei; Kondo, Akihiko; Akimoto, Seiji

    2015-08-01

    Some filamentous cyanobacteria (including Anabaena) differentiate into heterocysts under nitrogen-depleted conditions. During differentiation, the phycobiliproteins and photosystem II in the heterocysts are gradually degraded. Nitrogen depletion induces changes in the pigment composition of both vegetative cells and heterocysts, which affect the excitation energy transfer processes. To investigate the changes in excitation energy transfer processes of Anabaena variabilis filaments grown in standard medium (BG11) and a nitrogen-free medium (BG110), we measured their steady-state absorption spectra, steady-state fluorescence spectra, and time-resolved fluorescence spectra (TRFS) at 77 K. TRFS were measured with a picosecond time-correlated single photon counting system. The pigment compositions of the filaments grown in BG110 changed throughout the growth period; the relative phycocyanin levels monotonically decreased, whereas the relative carotenoid (Car) levels decreased and then recovered to their initial value (at day 0), with formation of lower-energy Cars. Nitrogen starvation also altered the fluorescence kinetics of PSI; the fluorescence maximum of TRFS immediately after excitation occurred at 735, 740, and 730 nm after 4, 8, and 15 days growth in BG110, respectively. Based on these results, we discuss the excitation energy transfer dynamics of A. variabilis filaments under the nitrogen-depleted condition throughout the growth period. PMID:25596847

  8. Effects of cadmium and copper on the ultrastructure ofAnkistrodesmus braunii andAnabaena 7120.

    Science.gov (United States)

    Massalski, A; Laube, V M; Kushner, D J

    1981-06-01

    The effects of brief exposure to, or growth in the presence of, lethal and sublethal concentrations of Cu(NO)2 and Cd(NO3) on the ultrastructure of the blue-green algaAnabaena 7120 and the green algaAnkistrodesmus braunii were studied. Exposure to increasing amount of both metal ions led to the appearance of larger proportions of electron-dense cells whose organelles were less well defined than those of untreated cells. Metal-treated cells ofAnabaena 7120 became distorted. Some had a corrugated appearance. Others lysed, leaving a much larger proportion of heterocysts. Such heterocysts were often empty or had a curious collapsed appearance. Growth ofA. braunii in the presence of 10(-4) M Cu(NO2)2 produced substantial numbers of multinucleate giant cells with thick walls; such cells result from repeated mitotic division without subsequent cytokinesis. The giant cells contained centrioles, structures not as yet found in normal cells of the genusAnkistrodesmus. Some nuclei of giant, but not of normal, cells contained deep indentations that appeared as "holes" in cross section. Some giant cells also contained triple parallel strands of endoplasmic reticulum which extended across much of the cell, connecting to the nuclear envelope. Some ultrastructural changes were also noted in algal cells grown over sediment containing Cu or Cd, but these were generally less severe than those occurring when metal ions were added directly to the algal cultures. PMID:24227427

  9. A detailed morphological, phylogenetic and ecophysiological analysis of four benthic Anabaena (Nostocales, Cyanobacteria) strains confirms deep heterogeneity within the genus

    Czech Academy of Sciences Publication Activity Database

    Kust, Andreja; Kozlíková-Zapomělová, Eliška; Mareš, Jan; Řeháková, Klára

    2015-01-01

    Roč. 15, č. 2 (2015), s. 191-202. ISSN 1802-5439 R&D Projects: GA ČR(CZ) GA14-18067S Institutional support: RVO:60077344 Keywords : Anabaena * crossed gradients * ecology * growth optima * morphology * phylogeny * polyphyly Subject RIV: DA - Hydrology ; Limnology Impact factor: 1.930, year: 2014

  10. Shortening the culture time in cytogenetic dosimetry using PCC-R assay

    International Nuclear Information System (INIS)

    The fast assessment of the dose received by exposed persons is crucial in radiological accidents, so the 48 h of cell culture in conventional cytogenetic dosimetry in addition to some limitations after high doses becomes a disadvantage. The premature chromosome condensation (PCC) assay permits to analyse enough cells after high radiation exposure, and the score of PCC-R may reduce the culture time up to 40-42 h. Peripheral whole-blood samples were exposed to 1-10 Gy of gamma radiation and cultured during 40 and 42 h. No statistical difference between frequencies was obtained between 40, 42 and 48 h of culture time, and PCC index decreased with the increase of the dose and increased with the culture time. The protocol proposed allows reduce the culture time down to 40 or 42 h when using the PCC-R assay with adequate precision in dose estimation. (authors)

  11. AcEST: BP912159 [AcEST

    Lifescience Database Archive (English)

    Full Text Available |B4UT81|B4UT81_9FLOR D1 protein (Fragment) OS=Phymatolithon re... 55 6e-15 tr|B4YYW2|B4YYW2_9BACT Photos...GSFSDGMPLGISGTFNFMIVF 186 >sp|Q8YQS7|PSBA3_ANASP Photosystem Q(B) protein 3 OS=Anabaena sp. (strain PCC 7120...GISGTF FMIVF+ Sbjct: 163 IGQGSFSDGMMLGISGTFNFMIVFS 187 >sp|Q3MCT0|PSBA1_ANAVT Photosystem Q(B) protein 1 OS=Anabaena variabilis (stra...DGMMLGISGTFNFMIVFS 187 >sp|Q3M5L6|PSBA4_ANAVT Photosystem Q(B) protein 6 OS=Anabaena variabilis (strain ATCC...>sp|B0CB14|PSBA1_ACAM1 Photosystem Q(B) protein 1 OS=Acaryochloris marina (strain MBIC 11017) GN=psbA1 PE=3

  12. Development and application of the PCC biodosimetry method in emergency preparedness

    International Nuclear Information System (INIS)

    A method for biological assessment of radiation dose for specific application in emergency preparedness was developed. Premature chromosome condensation (PCC) was investigated to provide a potentially faster means of analysis and the ability to assess higher doses than with the dicentric assay which is routinely applied in biodosimetry today. A review of existing methods was made, followed by experiments determine optimal assay conditions, and evaluations to determination of optimal conditions and the most appropriate endpoints for analyses. Twelve different experimental conditions were examined with four different evaluation approaches. Aspects during optimization such as practicality, speed, and reliability were considered. The conclusion from these studies was a PCC protocol utilizing okadaic acid for induction of PCC cells in stimulated lymphocytes but without the use of colcemid for metaphase arrest with the subsequent evaluation of ring chromosomes. Well-defined criteria were established for evaluation of PCC cells and ring chromosome aberrations. An inter-calibration was made by comparing assessment of ring chromosomes between all three laboratories. Agreement was made to count only rings with observable open spaces or large, obvious rings without open spaces. Finally a dose response curve for the PCC method was prepared and a comparison of the PCC method to the traditional dicentric assay in triage mode was made. The triage method requires a minimal number of evaluations so that categorization of high, medium and low doses may be made in an emergency situation where large numbers of people should be evaluated. The comparison of the PCC method with the dicentric assay triage method indicated that the PCC assay performed superior to the dicentric assay for evaluation of samples at higher doses, however, the dicentric assay appeared to provide more accurate dose assessment at lower doses. This project suggests a PCC assay method for biological dose estimates

  13. Development and application of the PCC biodosimetry method in emergency preparedness

    Energy Technology Data Exchange (ETDEWEB)

    Stricklin, D. (Swedish Defence Research Agency, FOI (Sweden)); Lindholm, C. (Finnish Radiation and Nuclear Safety Authority, STUK (Finland)); Jaworska, A. (Norwegian Radiation Protection Authority, NRPA (Norway))

    2008-07-15

    A method for biological assessment of radiation dose for specific application in emergency preparedness was developed. Premature chromosome condensation (PCC) was investigated to provide a potentially faster means of analysis and the ability to assess higher doses than with the dicentric assay which is routinely applied in biodosimetry today. A review of existing methods was made, followed by experiments determine optimal assay conditions, and evaluations to determination of optimal conditions and the most appropriate endpoints for analyses. Twelve different experimental conditions were examined with four different evaluation approaches. Aspects during optimization such as practicality, speed, and reliability were considered. The conclusion from these studies was a PCC protocol utilizing okadaic acid for induction of PCC cells in stimulated lymphocytes but without the use of colcemid for metaphase arrest with the subsequent evaluation of ring chromosomes. Well-defined criteria were established for evaluation of PCC cells and ring chromosome aberrations. An inter-calibration was made by comparing assessment of ring chromosomes between all three laboratories. Agreement was made to count only rings with observable open spaces or large, obvious rings without open spaces. Finally a dose response curve for the PCC method was prepared and a comparison of the PCC method to the traditional dicentric assay in triage mode was made. The triage method requires a minimal number of evaluations so that categorization of high, medium and low doses may be made in an emergency situation where large numbers of people should be evaluated. The comparison of the PCC method with the dicentric assay triage method indicated that the PCC assay performed superior to the dicentric assay for evaluation of samples at higher doses, however, the dicentric assay appeared to provide more accurate dose assessment at lower doses. This project suggests a PCC assay method for biological dose estimates

  14. Differentiation of free-living Anabaena and Nostoc cyanobacteria on the basis of fatty acid composition.

    Science.gov (United States)

    Caudales, R; Wells, J M

    1992-04-01

    The cellular fatty acids of free-living, nitrogen-fixing cyanobacteria belonging to the genera Anabaena and Nostoc were analyzed to differentiate the genera. The fatty acid compositions of 10 Anabaena strains and 10 Nostoc strains that were grown for 12 days on BG-11o medium were determined by gas-liquid chromatography-mass spectroscopy. Of the 53 fatty acids detected, 17 were major components; the average level for each of these 17 fatty acids was at least 0.9% of the total fatty acids (in at least one of the genera). These fatty acids included (with mean percentages in the Anabaena and Nostoc strains, respectively) the saturated fatty acids 16:0 (30.55 and 23.23%) and 18:0 (0.77 and 1.27%); several unsaturated fatty acids, including 14:1 cis-7 (2.50 and 0.11%), 14:1 cis-9 (3.10 and 3.41%), a polyunsaturated 16-carbon (sites undetermined) fatty acid with an equivalent chain length of 15.30 (1.20 and 1.03%), 16:4 cis-4 (0.95 and 0.87%), 16:3 cis-6 (2.16 and 1.51%), 16:1 cis-7 (1.44 and 0.36%), 16:1 cis-9 (6.53 and 18.76%), 16:1 trans-9 (4.02 and 1.35%), 16:1 cis-11 (1.62 and 0.42%), 18:2 cis-9 (10.16 and 12.44%), 18:3 cis-9 (18.19 and 17.25%), 18:1 cis-9 (4.01 and 5.10%), and 18:1 trans-9 (0.92 and 1.94%); and the branched-chain fatty acids iso-16:0 (2.50 and 1.14%) and iso-15:1 (0.34 and 2.05%).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1581185

  15. STARCH-SODIUM STEARATE COMPLEX MODIFIED PCC FILLER AND ITS APPLICATION IN PAPERMAKING

    OpenAIRE

    Huiming Fan,; Daoxuan Wang,; Wenrui Bai,; Jianan Liu

    2012-01-01

    The use of fillers tends to reduce paper strength, which can limit their application. Therefore research on filler modification is of significant importance in order to overcome this limitation. In this paper, precipitated calcium carbonate (PCC) was modified by starch, sodium stearate, and the starch cross-linking agent sodium hexametaphosphate. The purpose of this research is to provide useful references to the industrial application of modified precipitated calcium carbonate (PCC). Modifie...

  16. Solution Structure of Reduced Plastocyanin from the Blue-Green Alga Anabaena Variabilis

    DEFF Research Database (Denmark)

    Led, J.J.; Badsberg, U.; Jørgensen, A.M.;

    1996-01-01

    The three-dimensional solution structure of plastocyanin from Anabaena variabilis (A.v. PCu) has been determined by nuclear magnetic resonance spectroscopy. Sixty structures were calculated by distance geometry from 1141 distance restraints and 46 dihedral angle restraints. The distance geometry...... structures were optimized by simulated annealing and restrained energy minimization. The average rms deviation from the mean structure for the 20 structures with the lowest total energy is 1.25 Angstrom for the backbone atoms and 1.75 Angstrom for all heavy atoms. Overall, the global tertiary fold of A. v...... turn is compensated for by an extension of the small helix [from Ala53(51) to Ser60(58) in A.v. PCu] found in other plastocyanins. Moreover, the extra residues of A.v. PCu from Pro77 to Asp79 form an appended loop. These two features allow A.v. PCu to retain almost the same global fold as observed in...

  17. Effects of atmospheric SO[sub 2] on Azolla and Anabaena symbiosis

    Energy Technology Data Exchange (ETDEWEB)

    Hur, J.-S.; Wellburn, A.R. (Division of Biological Sciences, Institute of Environmental and Biological Sciences, Lancaster Univ., Lancaster (United Kingdom))

    1993-01-01

    The water fern Azolla pinnata R. Br. was fumigated for 1 week with either 25, 50 or 100 nl l[sup -1] SO[sub 2]. The symbiosis of Azolla with Anabaena azollae (spp.) was severely damaged by atmospheric SO[sub 2] even at the lowest concentration studied showing significant reductions in growth, reduction of C[sub 2]H[sub 2], NH[sub 3] assimilation, protein synthesis, and heterocyst development. These disturbances appear to be mainly responsible for the extreme sensitivity of this fern to atmospheric SO[sub 2]. Changes in violaxanthin/antheraxanthin and epoxylutein/lutein ratios also indicate that free radical products are induced by atmospheric SO[sub 2]. These results suggest that the Azolla-Anabeana symbiotic system is a very responsive and reliable lower plant model to study the detailed effects of total sulfur deposition upon the balances between various important plant metabolic processes.

  18. 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.

  19. Nitrogenase activity in cell-free extracts of the blue-green alga, Anabaena cylindrica.

    Science.gov (United States)

    Smith, R V; Evans, M C

    1971-03-01

    Cell-free extracts with high nitrogenase activity were prepared by sonic oscillation and French press treatment from the blue-gree alga Anabaena cylindrica. Extracts were prepared from cells grown on a 95% N(2)-5% CO(2) gas mixture followed by a period of nitrogen starvation under an atmosphere of 95% argon-5% CO(2). No increase in the specific activity of extracts was achieved by breaking heterocysts. Activity (assayed by acetylene reduction) was found to be dependent on adenosine triphosphate (ATP), an ATP-generating system, and a low-potential reductant. Na(2)S(2)O(2) employed as reductant supports higher rates of nitrogenase activity than reduced ferredoxin. The activity is associated with a small-particle fraction that can be sedimented by ultracentrifugation. In contrast to the particulate nitrogenase of Azotobacter, which is stable in air, the A. cylindrica nitrogenase is an oxygen sensitive as nitrogenase prepared from anaerobic bacteria. PMID:4994040

  20. A polyphasic approach leading to the revision of the genus Planktothrix (Cyanobacteria) and its type species, P. agardhii, and proposal for integrating the emended valid botanical taxa, as well as three new species, Planktothrix paucivesiculata sp. nov.ICNP, Planktothrix tepida sp. nov.ICNP, and Planktothrix serta sp. nov.ICNP, as genus and species names with nomenclatural standing under the ICNP.

    Science.gov (United States)

    Gaget, Virginie; Welker, Martin; Rippka, Rosmarie; de Marsac, Nicole Tandeau

    2015-05-01

    Twenty strains of Planktothrix and five of 'Oscillatoria' were characterized by a polyphasic approach, for clarification of their taxonomic relationships. Emphasis was given to the strains (17) of the Pasteur Culture Collection of Cyanobacteria (PCC). Phenotypic characters analyzed comprised morphology, phycobiliprotein composition, temperature and salinity tolerance. The gvpA gas vesicle gene was detected by PCR in all strains, and transmission electron microscopy confirmed gas vesicle formation in the strains of 'Oscillatoria'. MALDI-TOF mass spectrometry revealed 13 chemotypes, nine of which produce microcystins. A multi-locus sequence typing (MLST) analysis was conducted using individual and concatenated nucleotide sequences of the 16S rDNA, internal transcribed spacer (ITS), gyrB, rpoC1 and rpoB. The results highlighted an unexpected diversity within the genus Planktothrix, showing that the five strains of 'Oscillatoria' need to be included in this taxon. Consequently, the genus consists of seven phylogenetic clusters, three of which represent new species, named Planktothrix paucivesiculata sp. nov.ICNP (type strain: PCC 8926T), Planktothrix tepida sp. nov.ICNP (type strain: PCC 9214T) and Planktothrix serta sp. nov.ICNP (type strain: PCC 8927T). These, together with the emended genus Planktothrix and its type species P. agardhii, valid taxa under the ICN, are described/re-described for gaining nomenclatural standing under the ICNP. PMID:25757799

  1. Characterisation of the paralytic shellfish toxin biosynthesis gene clusters in Anabaena circinalis AWQC131C and Aphanizomenon sp. NH-5

    OpenAIRE

    Neilan Brett A; Kellmann Ralf; Mihali Troco K

    2009-01-01

    Abstract Background Saxitoxin and its analogues collectively known as the paralytic shellfish toxins (PSTs) are neurotoxic alkaloids and are the cause of the syndrome named paralytic shellfish poisoning. PSTs are produced by a unique biosynthetic pathway, which involves reactions that are rare in microbial metabolic pathways. Nevertheless, distantly related organisms such as dinoflagellates and cyanobacteria appear to produce these toxins using the same pathway. Hypothesised explanations for ...

  2. Interference of Quorum Sensing by Delftia sp. VM4 Depends on the Activity of a Novel N-Acylhomoserine Lactone-Acylase

    OpenAIRE

    Vimal B Maisuria; Nerurkar, Anuradha S.

    2015-01-01

    Background Turf soil bacterial isolate Delftia sp. VM4 can degrade exogenous N-acyl homoserine lactone (AHL), hence it effectively attenuates the virulence of bacterial soft rot pathogen Pectobacterium carotovorum subsp. carotovorum strain BR1 (Pcc BR1) as a consequence of quorum sensing inhibition. Methodology/Principal Findings Isolated Delftia sp. VM4 can grow in minimal medium supplemented with AHL as a sole source of carbon and energy. It also possesses the ability to degrade various AHL...

  3. Azolla filiculoides Nitrogenase Activity Decrease Induced by Inoculation with Chlamydomonas sp. †

    Science.gov (United States)

    Habte, Mitiku

    1986-01-01

    Experiments were conducted to determine the influence of Chlamydomonas sp. on nitrogen fixation (C2H2 → C2H4) in Azolla filiculoides and on the nitrogen fixation and growth of free-living Anabaena azollae 2B organisms. Inoculation of azolla medium with Chlamydomonas sp. was associated with decreased nitrogenase activity in A. filiculoides and with increases in the density of a fungal population identified as Acremonium sp. Subsequent inoculation of azolla medium with this fungus was also accompanied by a significant decrease in nitrogenase activity of A. filiculoides. However, the extent of depression of nitrogenase activity was significantly higher when azolla medium was inoculated with Chlamydomonas sp. than when it was inoculated with Acremonium sp. Inoculation of nitrogen-free Stanier medium with either Acremonium sp. or Chlamydomonas sp. did not adversely affect the growth or nitrogenase activity of free-living A. azollae. Decreased nitrogenase activity in A. filiculoides is apparently related to the adverse influence of the green alga and the fungus on the macrosymbiont. The mechanisms that might be involved are discussed. PMID:16347211

  4. Chromosome painting and prematurely condensed chromosomes (PCC) - new methods of biological dosimetry

    International Nuclear Information System (INIS)

    Classic methods of biological dosimetry - micronucleus and dicentric assay pose several problems. In the case of micronucleus there is a wide range of spontaneous frequencies and smoking and age are powerfull contributing factors. In the case of dicentrics - low mitotic index in some individuals especially in the elderly or accidentally exposed to high radiation doses. So, there are 2 quite new molecular techniques which at least in part solve these problems: chromosome painting and PCC. Chromosome painting by employing chromosome-specific DNA probes allow easy identification and quantification of translocations. recently, it was shown that calyculin A or okadaic acid, inhibitors of 1 and 2A protein phosphatases, induce PCC in peripheral blood cells. This is an easy biodosimetric method with a high PCC index and independent of the ability of cells to divide e.g. after high (20 Gy) doses when the mitotic index is extremely low. (author)

  5. Case Report: Apixaban-Associated Gluteal Artery Extravasation Reversed With PCC3 Without FFP.

    Science.gov (United States)

    Denetclaw, Tina Harrach; Tam, Jacqueline; Arias, Victor; Kim, Rachel; Martin, Christopher

    2016-08-01

    Apixaban, an oral factor Xa inhibitor, has no commercially available assay to measure its activity and no specific antidote. To date, recommendations for managing bleeding associated with apixaban are based on studies with animal models and healthy volunteers (who do not have identified thrombogenic risk factors) and expert opinion. No clinical experience has been published in the literature. Ideally, apixaban would be reversed sufficiently to stop a perilous bleed without producing more thrombogenic risk than the patients' underlying risk factors. Three-factor prothrombin complex concentrate (PCC3) is the least thrombogenic among the suggested reversal agents. Fresh frozen plasma (FFP) is sometimes recommended to add to PCC3, but it adds considerable volume. We describe successful management of an active left gluteal arterial extravasation due to trauma and associated apixaban, in a patient with aortic stenosis and atrial fibrillation, by administration of PCC3 alone, without the added volume of FFP. PMID:26519251

  6. PCC-ring induction in human lymphocytes exposed to gamma and neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lamadrid B, A.I.; Garcia L, O. [CPHR, Calle 20 No. 4113 e/41 y 47, Playa, La Habana 11300 (Cuba); Delbos, M.; Voisin, P.; Roy, L. [Institut de Radioprotection et de Surete Nucleaire, BP 17, 92262 Fontenay-aux-Roses (France)]. e-mail: ana@cphr.edu.cu

    2006-07-01

    Dose-effect curves for dose assessment in Gamma and neutron overexposures to high doses are presented in this paper for the first time in literature. The relationships were obtained by plotting the Premature Chromosome Condensation -rings (PCC-R) frequencies in PCC Iymphocytes obtained by chemical induction with Calyculin A in vitro, with radiation doses between 5 to 25 Gy. For the elaboration of these curves 9 676 PCC cells in Gl G2 and M stages were analyzed. The results were fitted to a lineal quadratic model in Gamma irradiation. For neutron irradiation the data was fitted to a lineal quadratic model up to 10 Gy and then a markedly cell cycle arrest and saturation was observed. These curves are of particular interest for victims exposed to doses exceeding 5 Gy where it is always very difficult to estimate a dose using the conventional technique. (Author)

  7. Production of precipitated calcium carbonate (PCC) from steelmaking slag for fixation of CO2

    International Nuclear Information System (INIS)

    Highlights: ► Ca extraction efficiency. ► Grain size and solid to liquid ratio. ► Production of PCC. - Abstract: Producing precipitated calcium carbonate (PCC) from steelmaking slag is a technology that contributes to the reduction of carbon dioxide emissions from iron and steel industries. While the carbon dioxide emissions from the sector are large, it could benefit from this option by utilizing its own by-products, i.e. steelmaking slags for fixation of CO2. Since the calcium content of the steelmaking slag is high, a calcium carbonate precipitate can be produced with the method which we have recently developed, and, if fulfilling the requirements (e.g. purity and crystal shape), it can be utilized as PCC. Therefore, the objective of this study is to further evaluate the feasibility of this method. Calcium was extracted selectively from the slag with aqueous solution of ammonium salt (NH4NO3, CH3COONH4 or NH4Cl) in an extraction reactor. After removal of the residual slag, the calcium-rich solution reacted with CO2 in a carbonation reactor producing PCC. Based on the experimental results, the slag’s grain size has a clear effect on the calcium extraction efficiency; the smaller the steel converter slag’s grain size, the larger the surface area, and the better the mass transfer rate which in turn results in a higher extraction efficiency. Grinding to smaller sizes is therefore one strategy towards improved efficiencies and chemical conversion rates. Solid to liquid ratio is another important parameter for improving extraction efficiency. The smallest solid to liquid ratio 5 g/l resulted in the maximum calcium extraction efficiency (73%) while the highest solid to liquid ratio 100 g/l resulted in the lowest extraction efficiency (6%). Consequently this option will be operationally expensive because of larger reactor volumes. The PCC produced from the calcium rich solution is comparable to the PCC produced with conventional methods

  8. Biosorption of cadmium and lead from aqueous solution by fresh water alga Anabaena sphaerica biomass

    Directory of Open Access Journals (Sweden)

    Azza M. Abdel -Aty

    2013-07-01

    Full Text Available The present work represents the biosorption of Cd(II and Pb(II from aqueous solution onto the biomass of the blue green alga Anabaena sphaerica as a function of pH, biosorbent dosage, contact time, and initial metal ion concentrations. Freundlich, Langmuir, and Dubinin–Radushkevich (D–R models were applied to describe the biosorption isotherm of both metals by A. sphaerica biomass. The biosorption isotherms studies indicated that the biosorption of Cd(II and Pb(II follows the Langmuir and Freundlish models. The maximum biosorption capacities (qmax were 111.1 and 121.95 mg/g, respectively, at the optimum conditions for each metal. From the D–R isotherm model, the mean free energy was calculated to be 11.7 and 14.3 kJ/mol indicating that the biosorption mechanism of Cd(II and Pb(II by A. sphaerica was chemisorption. The FTIR analysis for surface function group of algal biomass revealed the existence of amino, carboxyl, hydroxyl, and carbonyl groups, which are responsible for the biosorption of Cd(II and Pb(II. The results suggested that the biomass of A. sphaerica is an extremely efficient biosorbent for the removal of Cd(II and Pb(II from aqueous solutions.

  9. Solution structure of reduced plastocyanin from the blue-green alga Anabaena variabilis

    DEFF Research Database (Denmark)

    Badsberg, U; Jørgensen, A.M.; Gesmar, H;

    1996-01-01

    The three-dimensional solution structure of plastocyanin from Anabaena variabilis (A.v.PCu) has been determined by nuclear magnetic resonance spectroscopy. Sixty structures were calculated by distance geometry from 1141 distance restraints and 46 dihedral angle restraints. The distance geometry...... structures were optimized by simulated annealing and restrained energy minimization. The average rms deviation from the mean structure for the 20 structures with the lowest total energy is 1.25 A for the backbone atoms and 1.75 A for all heavy atoms. Overall, the global tertiary fold of A.v.PCu resembles...... extension of the small helix [from Ala53(51) to Ser60(58) in A.v.PCu] found in other plastocyanins. Moreover, the extra residues of A.v.PCu from Pro77 to Asp79 form an appended loop. These two features allow A.v.PCu to retain almost the same global fold as observed in other plastocyanins. From a comparison...

  10. Azolla-Anabaena's behaviour in urban wastewater and artificial media--influence of combined nitrogen.

    Science.gov (United States)

    Costa, M L; Santos, M C R; Carrapiço, F; Pereira, A L

    2009-08-01

    The results of using the nitrogen fixing symbiotic system Azolla-Anabaena to improve the quality of treated urban wastewater, particularly on what concerns phosphorus removal efficiencies (40-65%), obtained in continuous assays performed during the past few years and presented earlier, were very promising. Nevertheless, the presence of combined nitrogen in some wastewaters can compromise the treatment efficiency. The main goal of this work was to compare plants behaviour in wastewater and in mineral media with and without added nitrogen. Azolla filiculoides's specific growth rates in wastewater and in mineral media without added nitrogen or with low nitrate concentration were very similar (0.122 d(-1)-0.126 d(-1)), but decreased in the presence of ammonium (0.100 d(-1)). The orthophosphate removal rate coefficients were similar in all the growth media (0.210 d(-1)-0.232 d(-1)), but ammonium removal rate coefficient in wastewater was higher (0.117 d(-1)) than in mineral medium using that source of nitrogen (0.077 d(-1)). The ammonium present in wastewater, despite its high concentration (34 mg NL(-1)), didn't seem to inhibit growth and nitrogen fixation, however, in mineral media, ammonium (40 mg NL(-1)) was found to induce, respectively, 18% and 46% of inhibition. PMID:19559459

  11. Development mutants of anabaena doliolum defective in repair of UV-damage

    International Nuclear Information System (INIS)

    Nitrosoguanidine induced 'blue' pigment mutants of the blue-green alga anabaena doliolum were isolated. The blue-mutants on further characterization were grouped into three developmental phenotypes - (i) those forming doli-form blue-spores of heterogenous size i.e., Ad 011, (ii) those forming spheroidal cells in the stationary phase, some of which behave like spores on transfer to fresh medium i.e., Ad 012, and (iii) those showing no sporulation and conditionally producing abnormal cells in the presence of combined nitrogen only i.e., Ad 007. The former two classes of mutants showed the formation of abnormal cells irrespective of the presence or absence of combined nitrogen sources in the medium. The formation of abnormal cells in the filaments of the above mutants were distinguished by their larger size and irregular mode of division leading to true-branch formation. The comparative characterization of these mutant strains with the parental one showed sluggish growth, increased UV-sensitivity, almost unchanged photorepair capacity, a marked change in the pigment composition and relative resistance to nitrosoguanidine. Irregular cell division in both space and time in the mutant strains and their increased sensitivity to ultraviolet irradiation indicate the possible involvement of dark repair system in maintaining the precision of cell cylce in this alga. (orig.) 891 AJ/orig. 892 HIS

  12. 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.

  13. Characterization of Anabaena cylindrica Solution System Using Synchronous- Scan Fluorescence Spectroscopy

    Institute of Scientific and Technical Information of China (English)

    LIU Xian-li; DENG Nan-sheng; TAO Shu

    2005-01-01

    The characterization of the algae Anabaena cylindrica solu tion with Fe (Ⅲ) was investigated using fluorescence emission and syn chronous-scan spectroscopy. The ranges of concentrations of algae and Fe (Ⅲ) in aqueous solutions were 5. 0 × 107-2. 5 × 108 cell/L and 10-60μmol/L, respectively. The effective characterization method used was synchronous-scan fluorescence spectroscopy (SFS). The wavelength difference (△λ) of 90 nm was maintained between excitation wavelength (λex) and emission wavelength(λem ). The peak was observed at about λex 236 nm/λem 326 nm for synchronous-scan fluorescence spectroscopy. The fluorescence quenching in system of algae-Fe( Ⅲ)-HA was studied using synchronous-scan spectroscopy for the first time. Fe(Ⅲ) was clearly the effective quencher. The relationship between I0 / I (quenching efficiency)and c (concentration of Fe (Ⅲ) added) was a linear correlation for the al gae solution with Fe(Ⅲ). Also, Aldrich humic acid (HA) was found to be an effective quencher.

  14. The astaxanthin dideoxyglycoside biosynthesis pathway in Sphingomonas sp. PB304.

    Science.gov (United States)

    Kim, Se Hyeuk; Kim, Jin Ho; Lee, Bun Yeol; Lee, Pyung Cheon

    2014-12-01

    A major carotenoid in Sphingomonas sp. PB304, originally isolated from a river in Daejon City, South Korea, was identified as astaxanthin dideoxyglycoside. Gene clusters encoding the astaxanthin dideoxyglycoside biosynthetic enzymes were identified by screening Sphingomonas sp. PB304 fosmid libraries using degenerate probes that harbor highly conserved sequences from the Sphigomonas elodea-derived crtI and Nostoc sp. PCC 7120-dervied crtW genes. Selected positive gene clusters were fully sequenced and annotated, revealing genes encoding six putative carotenogenic enzymes: phytoene synthase (CrtB), phytoene desaturase (CrtI), lycopene cyclase (CrtY), carotene hydroxylase (CrtZ), carotene ketolase (CrtW), and glycosyltransferase (CrtX). All of the carotenogenic enzymes, except for CrtX, were functional in the recombinant host Escherichia coli expressing synthetic carotenogenic modules from Pantoea agglomerans. CrtX did not take up UDP-glucose or GDP-fucose as sugar substrates during the in vitro reaction. Although no direct experimental evidence was obtained for the function of Sphingomonas sp. PB304 CrtX, it can be categorized as a putative deoxyglycosyltransferase based on the presence of astaxanthin dideoxyglycoside in Sphingomonas sp. PB304, a putative corresponding gene in the carotenoid biosynthetic gene cluster, and high amino acid sequence homology to the existing glycosyltransferases. Therefore, we propose that astaxanthin dideoxyglycoside can be synthesized in Sphingomonas sp. PB304 via sequential reactions of six pathway enzymes, including CrtX on the phytoene intermediate. PMID:25193422

  15. Effect of light on the content of photosynthetically active pigments in plants. Pt. 4. Chromatic adaption in blue-green algae Anabaena cylindrica and A. variabilis

    Energy Technology Data Exchange (ETDEWEB)

    Czeczuga, B.

    1986-07-15

    The photosynthetic pigments (chlorophyll a, carotenoids and phycobiliprotein pigments) of two species of the genus Anabaena grown in white, red, yellow, green and blue light were examined. The highest concentration of the cells was observed in the sample with red light in case of the both species, and the smallest with blue light. The biggest amounts of chlorophyll a and carotenoids were included in the cells of samples with the yellow and the smallest in case of the red light. The ratio of two phycobiliproteins is as follows: - in Anabaena cylindrica: the highest amount of C-phycocyanin in the cells was observed in the case of the red light, and C-phycoerytherin was found in the blue light; - in Anabaena variabiles: the highest amount of C-phycocyanien in the cells was found in case of the yellow light, and allophycocyanin was found in the blue light.

  16. Sistemas de transporte de aminoácidos, amonio y urea en cianobacterias

    OpenAIRE

    Montesinos Gutiérrez, María Luz

    1997-01-01

    Al finalizar esta Tesis Doctoral, hemos sacado las siguientes conclusiones: 1. Las Cianobacterias son capaces de transportar un amplio rango de aminoácidos mediante un bajo número de sistemas de transporte que muestran, en general, baja especificidad de sustrato. Todas las estirpes estudiadas poseen, al menos, un sistema de transporte de aminoácidos neutros. 2. El sistema de transporte de aminoácidos neutros de Synechocystis sp. PCC 6803 y uno de los presentes en Anabaena sp. PCC 7120 son ...

  17. Response of cyanobacteria to low atmosphere pressure

    Science.gov (United States)

    Qin, Lifeng; Ai, Weidang; Guo, Shuangsheng; Tang, Yongkang; Yu, Qingni; Shen, Yunze; Ren, Jin

    Maintaining a low pressure environment would reduce the technological complexity and constructed cost of future lunar base. To estimate the effect of hypobaric of controlled ecological life support system in lunar base on terrestrial life, cyanobacteria was used as the model to exam the response of growth, morphology, physiology to it. The decrease of atmosphere pressure from 100 KPa to 50 KPa reducing the growth rates of Microcystis aeruginosa, Merismopedia.sp, Anabaena sp. PCC 7120, Anabaena Hos-aquae, the chlorophyll a content in Microcystis aeruginosa, Merismopedia.sp, Anabaena Hos-aquae, the carotenoid content in Microcystis aeruginosa, Merismopedia.sp and Anabaena sp. PCC 7120, the phycocyanin content in Microcystis aeruginosa. This study explored the biological characteristics of the cyanobacteria under low pressure condition, which aimed at understanding the response of the earth's life to environment for the future moon base, the results enrich the research contents of the lunar biology and may be referred for the research of other terrestrial life, such as human, plant, microbe and animal living in life support system of lunar base.

  18. The usefulness of premature chromosome condensation (PCC) technique in estimating radiation exposure and in cancer treatment

    International Nuclear Information System (INIS)

    In bio dosimetry, cytogenetic methods are useful to assess the absorbed dose of ionizing radiation and to evaluate the induced damage. Analysis of dicentrics frequencies (DC), translocations by fluorescent in situ hybridization (FISH) and micronuclei (MN) in cytokinesis blocked lymphocytes are the commonly used cytogenetic endpoints. These techniques consume 3-4 days for a sample. The absorbed doses in the range of 100mGy to 6Gy can be detected. As compared to these, premature chromosome condensation (PCC) has less artifacts, retains maximum damage and offers a broad dose-estimate-window ranging 0.03 Gy to 20 Gy. Besides, it facilitates the visualization of the damaged chromosomes in just 4 hours in cells from any part of the body. During accidental- or medical- exposure, the rapidity and sensitivity of PCC commands supremacy over other techniques. Furthermore, a wider dose detection range is an additional advantage. Cell cycle position of the sample can also be understood. PCC is employed to understand the mechanism of DNA repair and the induction of chromosomal aberrations. It has a potential application in diagnosis of genetic defects including ataxia telangiectasia(AT) and genetic disorders involving DNA repair deficiency. The effectiveness of various drugs in treatment of cancer and prognosis can also be assessed by this method. Integrating PCC with FISH, there could be an opportunity of discerning mixed radiation exposure in accident situations. (author)

  19. Dose - Response Curves for Dicentrics and PCC Rings: Preparedness for Radiological Emergency in Thailand

    International Nuclear Information System (INIS)

    Establishing in-vitro dose calibration curves is important for reconstruction of radiation dose in the exposed individuals. The aim of this pioneering work in Thailand was to generate dose-response curves using conventional biological dosimetry: dicentric chromosome assay (DCA) and premature chromosome condensation (PCC) assay. The peripheral blood lymphocytes were irradiated with 137Cs at a dose rate of 0.652 Gy/min to doses of 0.1, 0.25, 0.5, 0.75, 1, 2, 3, 4 and 5 Gy for DCA technique, and 5, 10, 15, 20 and 25 Gy for PCC technique. The blood samples were cultured and processed following the standard procedure given by the IAEA with slight modifications. At least 500-1,000 metaphases or 100 dicentrics/ PCC rings were analyzed using an automated metaphase finder system. The yield of dicentrics with dose was fitted to a linear quadratic model using Chromosome Aberration Calculation Software (CABAS, version 2.0), whereas the dose-response curve of PCC rings was fitted to a linear relationship. These curves will be useful for in-vitro dose reconstruction and can support the preparedness for radiological emergency in the country.

  20. Estructura genética del sistema de asimilación de nitrato y regulación global de la asimilación de nitrógeno en la cianobacteria synechococcus sp.

    OpenAIRE

    Luque Romero, Ignacio

    1994-01-01

    Los objetivos de este trabajo han sido profundizar en el estudio de la estructura genética de los genes implicados en la asimilación de nitrato en Synechococcus sp. PCC 7942, y contribuir al esclarecimiento del mecanismo de regulación de dichos genes mediante la proteína NtcA.

  1. Sequence of the gene coding for the β-subunit of dinitrogenase from the blue-green alga Anabaena

    OpenAIRE

    Mazur, Barbara J.; Chui, Chok-Fun

    1982-01-01

    The nitrogen fixation nif K gene of the blue-green alga Anabaena, which codes for the β-subunit of dinitrogenase, has been subjected to sequence analysis. The nif K protein is predicted to be 512 amino acids long, to have a Mr or 57,583, and to contain six cysteine residues. Three of these cysteines are within peptides homologous to FeS cluster-binding cysteinyl peptides from ferredoxins and from a high potential iron protein and, thus, may be ligands to which FeS clusters bind in dinitrogena...

  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. Protein (Cyanobacteria): 378930 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available ETDPGMSEEPSATDSEMPEETDPGMSEEPSATDSEMPEDGESETSGEFSPDNVEMPEESEPDLSEDSSDTDSEMPEETPSELEEEEEETSGNLEESSDQESQ ... ...tein PCC7418_0631 Halothece sp. PCC 7418 MKSQLIALLIATSIFPLSACATSPQEGEQSPVQEAPDTSDDNYGFPSEKESDPSEKTAPKDSESLEETDPGMSEEPSATDSEMSE

  4. Whole Cell Biosensor Using Anabaena torulosa with Optical Transduction for Environmental Toxicity Evaluation

    Directory of Open Access Journals (Sweden)

    Ling Shing Wong

    2013-01-01

    Full Text Available A whole cell-based biosensor using Anabaena torulosa for the detection of heavy metals (Cu, Pb, and Cd, 2,4-dichlorophenoxyacetate (2,4-D, and chlorpyrifos was constructed. The cyanobacteria were entrapped on a cellulose membrane through filtration. Then, the membrane was dried and fixed into a cylindrical well, which was designed to be attached to an optical probe. The probe was connected to fluorescence spectrometer with optical fibre. The presence of the toxicants was indicated by the change of fluorescence emission, before and after the exposure. The linear detection ranges for Cu, Pb, and Cd were 2.5–10.0 µg/L, 0.5–5.0 µg/L, and 0.5–10.0 µg/L, respectively, while 2,4-D and chlorpyrifos shared similar linear ranges of 0.05–0.75 µg/L. The biosensor showed good sensitivity with the lowest limits of detection (LLD for Cu, Pb, Cd, 2,4-D and chlorpyrifos determined at 1.195 µg/L, 0.100 µg/L, 0.027 µg/L, 0.025 µg/L, and 0.025 µg/L, respectively. The overall reproducibility of the biosensor (n=3 was <±6.35%. The biosensor had been tested with different combinations of toxicants, with the results showing predominantly antagonistic responses. The results confirmed that the biosensor constructed in this report is suitable to be used in quantitative and qualitative detections of heavy metals and pesticides.

  5. Regulation of Three Nitrogenase Gene Clusters in the Cyanobacterium Anabaena variabilis ATCC 29413

    Directory of Open Access Journals (Sweden)

    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.

  6. Structure of an Inward Proton-Transporting Anabaena Sensory Rhodopsin Mutant: Mechanistic Insights.

    Science.gov (United States)

    Dong, Bamboo; Sánchez-Magraner, Lissete; Luecke, Hartmut

    2016-09-01

    Microbial rhodopsins are light-activated, seven-α-helical, retinylidene transmembrane proteins that have been identified in thousands of organisms across archaea, bacteria, fungi, and algae. Although they share a high degree of sequence identity and thus similarity in structure, many unique functions have been discovered and characterized among them. Some function as outward proton pumps, some as inward chloride pumps, whereas others function as light sensors or ion channels. Unique among the microbial rhodopsins characterized thus far, Anabaena sensory rhodopsin (ASR) is a photochromic sensor that interacts with a soluble 14-kDa cytoplasmic transducer that is encoded on the same operon. The sensor itself stably interconverts between all-trans-15-anti and 13-cis-15-syn retinal forms depending on the wavelength of illumination, although only the former participates in a photocycle with a signaling M intermediate. A mutation in the cytoplasmic half-channel of the protein, replacing Asp217 with Glu (D217E), results in the creation of a light-driven, single-photon, inward proton transporter. We present the 2.3 Å structure of dark-adapted D217E ASR, which reveals significant changes in the water network surrounding Glu217, as well as a shift in the carbon backbone near retinal-binding Lys210, illustrating a possible pathway leading to the protonation of Glu217 in the cytoplasmic half-channel, located 15 Å from the Schiff base. Crystallographic evidence for the protonation of nearby Glu36 is also discussed, which was described previously by Fourier transform infrared spectroscopy analysis. Finally, two histidine residues near the extracellular surface and their possible role in proton uptake are discussed. PMID:27602724

  7. PHOTOSYNTHETIC, BIOCHEMICAL AND ENZYMATIC INVESTIGATION OF Anabaena fertilissima IN RESPONSE TO AN INSECTICIDE-HEXACHLORO-HEXAHYDRO-METHANOBENZODIOXATHIEPINE- OXIDE

    Directory of Open Access Journals (Sweden)

    Kumar, Nirmal J.I

    2009-09-01

    Full Text Available A study on the heterocystous, nitrogen fixing cyanobacterium, Anabaena fertilissima was carried out to investigate the effect of an organochlorine insecticide (hexachloro-hexahydro-methano-benzodioxathiepineoxide, called as endosulfan at different concentrations of 3, 6 and 12 μgml-1 on the photosynthetic pigments-Chl-a, Carotenoids and Phycobiliproteins-phycocyanin, allophycocyanin and phycoerythrin, stress metabolites such as carbohydrates, proteins, amino acids, phenols and enzyme activities-nitrate reductase and glutamine synthetase. The insecticide- Endosulfan showed to be deleteriously affecting the activities in the cyanobacterium. As early as the 4th day, chl-a and carotenoids reduced by 38% and 20% respectively. The phycobiliproteins declined by 60%, 64% and 28% with respect to Phycocyanin, Allophycocyanin and Phycoerythrin. Moreover, Endosulfan adversely depleted the cellular activities, leading to a marked decrease in the carbohydrates, proteins, phenols and amino acids and enzymes-nitrate reductase and glutamine synthetase. Despite of deleterious effects of Endosulfan on the cyanobacterium Anabaena fertilissima, a unique regenerating ability in presence of the insecticide was observed by the end of 12 days in the lower doses of insecticide.

  8. Time-dependent growth of crystalline Au(0)-nanoparticles in cyanobacteria as self-reproducing bioreactors: 2. Anabaena cylindrica.

    Science.gov (United States)

    Rösken, Liz M; Cappel, Felix; Körsten, Susanne; Fischer, Christian B; Schönleber, Andreas; van Smaalen, Sander; Geimer, Stefan; Beresko, Christian; Ankerhold, Georg; Wehner, Stefan

    2016-01-01

    Microbial biosynthesis of metal nanoparticles as needed in catalysis has shown its theoretical ability as an extremely environmentally friendly production method in the last few years, even though the separation of the nanoparticles is challenging. Biosynthesis, summing up biosorption and bioreduction of diluted metal ions to zero valent metals, is especially ecofriendly, when the bioreactor itself is harmless and needs no further harmful reagents. The cyanobacterium Anabaena cylindrica (SAG 1403.2) is able to form crystalline Au(0)-nanoparticles from Au(3+) ions and does not release toxic anatoxin-a. X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and laser-induced breakdown spectroscopy (LIBS) are applied to monitor the time-dependent development of gold nanoparticles for up to 40 hours. Some vegetative cells (VC) are filled with nanoparticles within minutes, while the extracellular polymeric substances (EPS) of vegetative cells and the heterocyst polysaccharide layer (HEP) are the regions, where the first nanoparticles are detected on most other cells. The uptake of gold starts immediately after incubation and within four hours the average size remains constant around 10 nm. Analyzing the TEM images with an image processing program reveals a wide distribution for the diameter of the nanoparticles at all times and in all regions of the cyanobacteria. Finally, the nanoparticle concentration in vegetative cells of Anabaena cylindrica is about 50% higher than in heterocysts (HC). These nanoparticles are found to be located along the thylakoid membranes. PMID:27335727

  9. Time-dependent growth of crystalline Au0-nanoparticles in cyanobacteria as self-reproducing bioreactors: 2. Anabaena cylindrica

    Science.gov (United States)

    Rösken, Liz M; Cappel, Felix; Körsten, Susanne; Fischer, Christian B; Schönleber, Andreas; van Smaalen, Sander; Geimer, Stefan; Beresko, Christian; Ankerhold, Georg

    2016-01-01

    Summary Microbial biosynthesis of metal nanoparticles as needed in catalysis has shown its theoretical ability as an extremely environmentally friendly production method in the last few years, even though the separation of the nanoparticles is challenging. Biosynthesis, summing up biosorption and bioreduction of diluted metal ions to zero valent metals, is especially ecofriendly, when the bioreactor itself is harmless and needs no further harmful reagents. The cyanobacterium Anabaena cylindrica (SAG 1403.2) is able to form crystalline Au0-nanoparticles from Au3+ ions and does not release toxic anatoxin-a. X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and laser-induced breakdown spectroscopy (LIBS) are applied to monitor the time-dependent development of gold nanoparticles for up to 40 hours. Some vegetative cells (VC) are filled with nanoparticles within minutes, while the extracellular polymeric substances (EPS) of vegetative cells and the heterocyst polysaccharide layer (HEP) are the regions, where the first nanoparticles are detected on most other cells. The uptake of gold starts immediately after incubation and within four hours the average size remains constant around 10 nm. Analyzing the TEM images with an image processing program reveals a wide distribution for the diameter of the nanoparticles at all times and in all regions of the cyanobacteria. Finally, the nanoparticle concentration in vegetative cells of Anabaena cylindrica is about 50% higher than in heterocysts (HC). These nanoparticles are found to be located along the thylakoid membranes. PMID:27335727

  10. The LysR-type transcription factor PacR is a global regulator of photosynthetic carbon assimilation in Anabaena.

    Science.gov (United States)

    Picossi, Silvia; Flores, Enrique; Herrero, Antonia

    2015-09-01

    Cyanobacteria perform water-splitting photosynthesis and are important primary producers impacting the carbon and nitrogen cycles at global scale. They fix CO2 through ribulose-bisphosphate carboxylase/oxygenase (RuBisCo) and have evolved a distinct CO2 concentrating mechanism (CCM) that builds high CO2 concentrations in the vicinity of RuBisCo favouring its carboxylase activity. Filamentous cyanobacteria such as Anabaena fix CO2 in photosynthetic vegetative cells, which donate photosynthate to heterocysts that rely on a heterotrophic metabolism to fix N2 . CCM elements are induced in response to inorganic carbon limitation, a cue that exposes the photosynthetic apparatus to photodamage by over-reduction. An Anabaena mutant lacking the LysR-type transcription factor All3953 grew poorly and dies under high light. The rbcL operon encoding RuBisCo was induced upon carbon limitation in the wild type but not in the mutant. ChIP-Seq analysis was used to globally identify All3953 targets under carbon limitation. Targets include, besides rbcL, genes encoding CCM elements, photorespiratory pathway- photosystem- and electron transport-related components, and factors, including flavodiiron proteins, with a demonstrated or putative function in photoprotection. Quantitative reverse transcription polymerase chain reaction analysis of selected All3953 targets showed regulation in the wild type but not in the mutant. All3953 (PacR) is a global regulator of carbon assimilation in an oxygenic photoautotroph. PMID:25684321

  11. Sequence of the nifD gene coding for the α subunit of dinitrogenase from the cyanobacterium Anabaena

    Science.gov (United States)

    Lammers, Peter J.; Haselkorn, Robert

    1983-01-01

    The nucleotide sequence of nifD, the structural gene for the α subunit of dinitrogenase from Anabaena 7120, has been determined. The coding sequence contains 1,440 nucleotides, which predict an amino acid sequence of 480 residues and Mr of 54,283. The predicted sequence contains eight cysteines, of which five are conserved with respect to adjoining sequences and position relative to the α subunits of dinitrogenase from Azotobacter, Clostridium, and Klebsiella. Because there are also five conserved cysteines in the β subunit of Anabaena dinitrogenase [Mazur, B. J. & Chiu, C.-F. (1982) Proc. Natl. Acad. Sci. USA 79, 6782-6786], the number of cysteine residues participating as ligands to FeS clusters is likely to be 20 per α2β2 tetramer. This number is sufficient to accommodate the known four Fe4S4 clusters, leaving at least four cysteines to be shared among the two FeMo cofactors and the more poorly characterized two-iron center. Although the α- and β-subunit gene sequences are not recognizably homologous, their secondary structures, predicted from the sequences, indicate similar domains around three of the conserved cysteine residues. PMID:16593347

  12. Genome Sequence of Pectobacterium carotovorum subsp. carotovorum Strain PCC21, a Pathogen Causing Soft Rot in Chinese Cabbage

    OpenAIRE

    Park, Tae-Ho; Choi, Beom-Soon; Choi, Ah-Young; Choi, Ik-Young; Heu, Sunggi; Park, Beom-Seok

    2012-01-01

    Pectobacterium carotovorum is a plant-pathogenic enterobacterium responsible for soft rot in various commercially important plants. Here we report the complete genome sequence and automatic annotation of strain PCC21.

  13. Generation and Evaluation of a Genome-Scale Metabolic Network Model of Synechococcus elongatus PCC7942

    Directory of Open Access Journals (Sweden)

    Julián Triana

    2014-08-01

    Full Text Available The reconstruction of genome-scale metabolic models and their applications represent a great advantage of systems biology. Through their use as metabolic flux simulation models, production of industrially-interesting metabolites can be predicted. Due to the growing number of studies of metabolic models driven by the increasing genomic sequencing projects, it is important to conceptualize steps of reconstruction and analysis. We have focused our work in the cyanobacterium Synechococcus elongatus PCC7942, for which several analyses and insights are unveiled. A comprehensive approach has been used, which can be of interest to lead the process of manual curation and genome-scale metabolic analysis. The final model, iSyf715 includes 851 reactions and 838 metabolites. A biomass equation, which encompasses elementary building blocks to allow cell growth, is also included. The applicability of the model is finally demonstrated by simulating autotrophic growth conditions of Synechococcus elongatus PCC7942.

  14. Growth response of Spirulina platensis PCC9108 to elevated CO2 levels and flue gas

    OpenAIRE

    Seyedmahdi Hoseini; Abbas Almodares; Saeed Afsharzadeh; Mohamad Sadegh Hatamipur; Fatemeh Montazeri

    2014-01-01

    Introduction: Because their ability to capture CO2, photosynthetical microorganisms have some advantages to CO2 mitigation from high CO2 streams such as flue gases and they can use CO2 as carbon source. Recently, experts have made efforts to exploit microorganisms intended for recovering CO2 from power plants. Materials and methods: To achieve this purpose, we studied the growth response of the cyanobacterium Spirulina platensis PCC9108 under different concentrations of carbon dioxide (ra...

  15. Increase of the filler content by using a silica-coated PCC filler

    OpenAIRE

    Lourenço, A.F.; Gamelas, J.A.F.; Ferreira, P. J.

    2014-01-01

    The increase of filler content in paper without significantly sacrificing the paper mechanical resistances is of high interest for papermakers. In this work, precipitated calcium carbonate (PCC) modified with silica was used as filler for papermaking. Handsheets based on a eucalyptus kraft pulp furnish with different amounts of the modified filler, ranging from 16 to 40%, were produced. For similar levels of filler content it was found that the strength properties of the handsheets produce...

  16. Blueprint for a minimal photoautotrophic cell: conserved and variable genes in Synechococcus elongatus PCC 7942

    Directory of Open Access Journals (Sweden)

    Peretó Juli

    2011-01-01

    Full Text Available Abstract Background Simpler biological systems should be easier to understand and to engineer towards pre-defined goals. One way to achieve biological simplicity is through genome minimization. Here we looked for genomic islands in the fresh water cyanobacteria Synechococcus elongatus PCC 7942 (genome size 2.7 Mb that could be used as targets for deletion. We also looked for conserved genes that might be essential for cell survival. Results By using a combination of methods we identified 170 xenologs, 136 ORFans and 1401 core genes in the genome of S. elongatus PCC 7942. These represent 6.5%, 5.2% and 53.6% of the annotated genes respectively. We considered that genes in genomic islands could be found if they showed a combination of: a unusual G+C content; b unusual phylogenetic similarity; and/or c a small number of the highly iterated palindrome 1 (HIP1 motif plus an unusual codon usage. The origin of the largest genomic island by horizontal gene transfer (HGT could be corroborated by lack of coverage among metagenomic sequences from a fresh water microbialite. Evidence is also presented that xenologous genes tend to cluster in operons. Interestingly, most genes coding for proteins with a diguanylate cyclase domain are predicted to be xenologs, suggesting a role for horizontal gene transfer in the evolution of Synechococcus sensory systems. Conclusions Our estimates of genomic islands in PCC 7942 are larger than those predicted by other published methods like SIGI-HMM. Our results set a guide to non-essential genes in S. elongatus PCC 7942 indicating a path towards the engineering of a model photoautotrophic bacterial cell.

  17. Transcriptome landscape of Synechococcus elongatus PCC 7942 for nitrogen starvation responses using RNA-seq.

    Science.gov (United States)

    Choi, Sun Young; Park, Byeonghyeok; Choi, In-Geol; Sim, Sang Jun; Lee, Sun-Mi; Um, Youngsoon; Woo, Han Min

    2016-01-01

    The development of high-throughput technology using RNA-seq has allowed understanding of cellular mechanisms and regulations of bacterial transcription. In addition, transcriptome analysis with RNA-seq has been used to accelerate strain improvement through systems metabolic engineering. Synechococcus elongatus PCC 7942, a photosynthetic bacterium, has remarkable potential for biochemical and biofuel production due to photoautotrophic cell growth and direct CO2 conversion. Here, we performed a transcriptome analysis of S. elongatus PCC 7942 using RNA-seq to understand the changes of cellular metabolism and regulation for nitrogen starvation responses. As a result, differentially expressed genes (DEGs) were identified and functionally categorized. With mapping onto metabolic pathways, we probed transcriptional perturbation and regulation of carbon and nitrogen metabolisms relating to nitrogen starvation responses. Experimental evidence such as chlorophyll a and phycobilisome content and the measurement of CO2 uptake rate validated the transcriptome analysis. The analysis suggests that S. elongatus PCC 7942 reacts to nitrogen starvation by not only rearranging the cellular transport capacity involved in carbon and nitrogen assimilation pathways but also by reducing protein synthesis and photosynthesis activities. PMID:27488818

  18. Application of PCC control strategy%PCC业务管控策略应用探析

    Institute of Scientific and Technical Information of China (English)

    焦金涛; 杨博; 许碧洲; 杨春来

    2014-01-01

    移动互联网的到来乃至物联网的快速发展,正在极大的改变用户行为习惯。同时各种新型终端和应用的大量涌现,对网络流量造成巨大的压力,而现网PCC管控策略的应用效果并不理想。介绍业务管控策略配置原理和部分PCC策略场景的业务流程,分析对现有网络设备的要求,并给出PCC的部署建议。%The rapid development of mobile internet and internet of things have changed people’s behavior and habits greatly. At the same time, a lot of new emerging terminals and applications leave heavy burden on the network traffic, but the work of current PCC control strategy was not ideal. This paper introduces the configuration principle of business control strategy and part of the business process of PCC strategy, makes analysis on existing equipment requirements, and gives suggestions on PCC deployment.

  19. Protein (Cyanobacteria): 69702 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available osphatase Oscillatoria sp. PCC 6506 MNHLIKQADLADRIICDSAGTGGYHVGNPPDRRMAIAASKRELELRGSARKFQRSDFENFDLILAMDKDNYQDILSLDPHGKYRDKVRLMCEFCQKYDLREVPDPYYGGPEGFDRVIDLLWDACEGLLEYVTKEKLIFNS ...

  20. Protein (Cyanobacteria): 316244 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available _3027 Synechocystis sp. PCC 6803 MLKLAGKKASALTCKKTKAKIGILEMDRQWYQSVKRFLCPSFEISAINFQDILFNNVDVGEYHSILVGCGIKYESIDISATLDLVTIIKKLSAKPPALLLITDCADSQITVQARSYLPQIDGVFAKDHDLALLLKVMKIIAKQKYFK ...

  1. Protein (Cyanobacteria): 42724 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available anothece sp. PCC 7425 MAITRWEPFRRIERWEPLREMETLRREMDRLFDRMIPFGDGEEGLLAFTPSVEMEETDEAINLRLEIPGMDPKDLDIQVSEESVSIRGERKSESRTEEQGTIRSEFRYGKFQRIIPLPAHIQTDQVKAENRQGVLHLILPKAEEERRKVVKVQID ...

  2. Protein (Cyanobacteria): 264443 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available Leptolyngbya sp. PCC 7376 MKRLFLSLSVAMVALAIAKPAMAENPDHVARLLETGACQGCNLIGAELSGKHLIGADLRDANLSYANLANANLEGADLTGANLAGADMTEAFLTNAVLNNARLDRVDFTAAKMYDTLVVDASMEDLTLTDAELYNTAISVGGSYEQFVPEGE ...

  3. Protein (Cyanobacteria): 207811 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available bya sp. PCC 7375 MVAPITISPATRNDIPLLFELVMALAEYEDLAHEVSGAPEDLEKYLFGDSPKAHAIVARIDGAPAGFALYFFNFSTFLMKPGIYLEDLFVLPGYRRRGIGTAIFQYLAQTALAKGCGRFEWSVLDWNQPAIDFYRSKGAVMLNDWRTCRVAGIALEELATSEQ ...

  4. Protein (Cyanobacteria): 302381 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available Geitlerinema sp. PCC 7407 MKLSAQSVEKLEKFFARLQSETYPESPSNIHTAITEQMIGFFFQHYSLPASAKVLDVGCGQGVALERFQARGFRPVGITLNETDVRVCQEKGF...EVYQMDQSFLDFDDEQFEFIWCRHCLEHSVFPYFTLSELSRVLKPGGYLYVEVPAPDTVCRHQSNGNHYSVLGKTMWLELFQRSGFRNLNVLDLTFEVVAGPDLYWAFIQQKS ...

  5. Protein (Cyanobacteria): 290162 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available in Cyanothece sp. PCC 7822 MTYQSTSQQKQHFLIVEDDKGRWEISLTEPSYSLGRSPDCDIRLRSQFVSRHHATLVRFVKDDGQSYYRILDGDGKGRPSANGLRINGRKVQGCDLKHGDEVVFSPQVVAVYQYRQRDEFTTQPGNDPFDITLIDPAMMINDDDITEFQ ...

  6. Protein (Cyanobacteria): 447148 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available tein Oscillatoria sp. PCC 6506 MNRNMKSLPECEEYRSDKKIVLQENKSKITFLNLNQDPILIIKVDGCVISDNETLRCDYALIPYDTVEIYVELKGSDTSQAVKQLESTIRLLSKNPQKIKKLCFVVSTRVPQQATTIQQLQIQFKKKFNASFRIKNIQDEYDLSTCIT ...

  7. Protein (Cyanobacteria): 269641 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available ETVLAAFSAGADAYCMKDSRTELLIEAIQATHGGFAWIDPAIARIVLAHAPGAEPSEPSSPSRTSLSYGLTERELEVLQLIVDGCSNADIAEKLYITVGTVKTHVRNILNKLCANDRTQAAVRAIRSGLVN ... ...tis sp. PCC 6803 MEKIRIALIEDEDLIRQGLQDALTMEPSFEWVGEAANGRLGLVMMQQTRPDVVIIDIGLPDMNGIDVTQQLKKGPLNCQCRVVILTLNDQE

  8. Protein (Cyanobacteria): 214831 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available Cyanothece sp. PCC 7424 MQDAITSVINSADVQGKYLDGSAMDKLKSYFSTGELRVRAASVISANAAQIVKEAVAKSLLYSDVTRPGGNMYTTRRYAACIRDLDYYLRYATYAM...LAGDPSILDERVLNGLKETYNSLGVPISSTVQAIQAMKEVTASLVGADAGKEMGVYFDYICSGLS ...

  9. Protein (Cyanobacteria): 305620 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available LVHKIVVILRHNDMLSWGEKIELAKSAISMHFGNDNTLKLLKYYVVKTLRSFDTATLARQDDRFSPQMRNNFYRNRSDTMQPYLGSMEGAVLSGKLTAQAINAAHQSANSYSLQMQNIQPATNAATA ... ...a sp. PCC 7428 MRVAIAGADLAGLSCTKYLTDAGHTPIVWKSQDVSASLIAAWQDNKGDWYERLRICFGTYPKMKLQLLTKHATIFNQPDNLGTHSTVNSDLPA

  10. Protein (Cyanobacteria): 144500 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available GKRTAGIDGQTATTPAERVKLVREMLTYSLWQAKPARRVYIPKANGKQRPLGIPTVKNRVAQAVVKNALEPIWEAEFEANSYGFRPGRSCHDALEQSWIRLQKGMDTWVLDADIKGAFDNISHE ... ...riptase Microcoleus sp. PCC 7113 MKDRFSNEIGAKEPPTEWSDIDWKTIKERVRNLRRRIYRAKQNGQWNKVRSLMKLMLRSYSNLLLSVRRVTQENQ

  11. Protein (Cyanobacteria): 207109 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available ASELNLAEDAEIELGYRLCQSSWGKGYATEGSKALINKGFRELNVKKVCAFALERNKASRRVMEKSGLKIDREFMFTEQQLPYFKEEVDRKGVKYALTQEDFLKINKT ... ...ce sp. PCC 7424 MKVFLETERLILRYLTEADGDNLFQLDQDPQVMYFINGGQPTDYEIIKNKVLPRFLAYYEKYENLGTWGVVEKKTQNFLGWILFRPACEFIF

  12. Protein (Cyanobacteria): 103272 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available LPNTSEVLDQEYLKNADFWTKDALKDRFRTCNKAYQYLQKTYGFKFKPSWDKVLEAFNTGGKRESITLEKEVESLKQTVNLQQQQINKLEQQNTLLEAKLNEVLRLVNSANFQNRKE ... ..._18886 Lyngbya sp. PCC 8106 MPNILETLQDESRFDKINKSINKVNQGVENLSDIAENLADQTVDAVESGMRFGYAYAQVEAGEKQSSNSDEYIDVEVASL

  13. Protein (Cyanobacteria): 358615 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

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

  14. Protein (Cyanobacteria): 208240 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available yanothece sp. PCC 8802 MSKQIKQVDLVPFCQEEDSDRIQFWLNTPHVKKWWINPDNHFNNILNHPSSDHGIIIADGIKVGYLRWQKVDMLELASVGITTIP...EGSIDIDIFIGEKDYIGCGIGSRILKQLVNQLAQDTTIPLIGMATSVDNFIAIKAYQKVGFRCLFQFDSPTYGRCWILALNPQES ...

  15. Protein (Cyanobacteria): 208238 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available ece sp. PCC 8801 MSKQIKQVDLVPFCQEEDSDRIQFWLNTAHVKKWWINPDNHFKNILNHPSSDHGIIIADGIKVGYLRWQKVDMLELASVGITTIPEGSIDI...DIFIGEKDYIGCGIGSRILKQLVNQLAQDTTIPLIGMATSVDNFIAIKAYQKVGFRCLFQFDSPTYGRCWILALNPQES ...

  16. Protein (Cyanobacteria): 194274 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available KFLQHSDQTMLLASHDLEFLLEVCDRIVLIDEGRIIADGDPTEVMGNKAMMEAHGLEKPHSLIPHVEPHHNRPSQGHDYKEKARKT ... ...GTIHLFNKPVEPNKFNPEMGFLFQDPEDQLFSPSVWDDVAFGPQNLGLSDAEVKERVEAALELTGIENLAERPPHHLSGGEKQMVAIAGLLAMGPRVLFYDEPTASLDLRTRRRLI... Leptolyngbya sp. PCC 7376 MTSFSSSTIPSVKIPTRKELLVRPVAIALRDISFSYPDTPNVLSGVNLSIREGERVGLIGHNGCGKTTLFMLVCGLLKPSI

  17. Protein (Cyanobacteria): 320019 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available IPVRKPKKLPAPVYQAEYALEYGTDRLEMHQDAFGNGSRVLIVDDVIATGGTASATAKLVELGGGIVVGFAFLIELSFLSGRLALPANIPIFSLVSY ... ...ferase Synechococcus sp. PCC 7502 MDIKSLIRDIPDFPTPGIMFRDITPVLAHPQGLSEITNGLVNLTQDLHIDYVVGIESRGFILGAPIAYKLQAGF

  18. Protein (Cyanobacteria): 389314 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available DIKNHRTLTRYGITTVGFANATDAEIESYIDTGEPLNCAGCCTLEGLGGFLIEGLEGCHTNVLGLSLPLLREMLQALGYSLKFAGHKVEINPQSF ... ...s sp. PCC 7502 MSPLFVLASASPARRAILIQAGIDPFVAVSNFDEDQITTTDPIELVQILAKSKAEAVQSRFQDQEALILGCDSVMVVDGEIFGKPIYKERAIAMWEKMRGNQGELYTGHCLI

  19. Protein (Cyanobacteria): 255565 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available GVDLSPNALALAQKNLDPFRQVELRETDFLTYLGEANQTAPASFDLIHVGFSLHHLLPEEKEQFFAHCFSLLRPGGCLVIYDVFRQPEQNRQQYIEAYLAKAESQWTALAPDQLQAIAAHIKECDFPELVATMAEIGQKVGFIPPQVLFTEPRGFHHCFAFAISQSGKALAQDGV ... ...352 Synechocystis sp. PCC 6803 MASSPRPTEQTKQFFQQWQTYQQLVDHNYMAHRQIHQAVGALIQQQFDRPFDFLDLGCGDAQAIAKTLTGSKINSYT

  20. Protein (Cyanobacteria): 59184 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available hocystis sp. PCC 6803 MTLNLYFLRHGETTSSQTGTFCGRLDIDLTSHGYQMAHQFAEAYKDVSWTAIFASPLHRTMATATPLSKLINLPIQKRDGLKEIAY...GEWEGKTPAEVNQQFHDDYVRWLADPGWNAPSGGEKGIDIARRSSEVLEEIERTFTTGNVLVVSHKSTIRIMLCSLLGIDIGRFRDRIGMPVAAVSIVTMSEHGPLIEVMGDRSHLNQDLRDRYGT ...

  1. Protein (Cyanobacteria): 69941 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available l regulator Rivularia sp. PCC 7116 MNSLKNKPLDPVNHAGFLIWQVANNWEKQINNELKEFGLNQAEYFHLVSLFWLLENQEEVTQTEIARFADTIPMNTSKIMTKFEKKGLITRVAGSDSRSKSLCITESGEQIAIQATARLSRLSEQFFDKDDDNNFLNYLKYLKTK ...

  2. Protein (Cyanobacteria): 78536 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 4516 Lyngbya sp. PCC 8106 MSFTQPSQPQPHSSLISFSDGWFILPRRVFPHHTDYAGIVWHGTYMTWMEELRVEGLHWLGVNYSDLVAMGCDLPVVELKVRYHLSVKMGMTILIKGQPLPIKGVRMVWDYQIVSEDHQQLYVSGQVTLVPLSRETGKIMRRLPPLLQDAIAQIQG ...

  3. Protein (Cyanobacteria): 19890 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available PNEAKPESTEADRQQATPDEMVTVSVYTIDDQCNEFVEQSVEVPSDQAIATAVGKAMGSVEYNAFKLAGYQVDINGSTAIVDMQLAPGSQRQFVSLSSCEQRALFGSVEETLLNNNDWDVEAVKFTTSGKELIL ... ...2708 Synechococcus sp. PCC 7335 MLYSVLRQMVRLPESIQKHISRQLSQTRTAGLALMLSLVFVGCASAPDTVTVDPEETPTAQIDPPSDEAQAPDKVQ

  4. Protein (Cyanobacteria): 37541 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available GIIMCDPEWKVKIGVEIFIFIHHPNEDFSDLLMRWRLTQVCLDQGYEWVMPHHYSHIYSQEAEKIYPLFVLFSETPERIKRGLQGANLPFVIPALDTTVDPSDYQSIDELDEFDLEHHPEWKSWGDINSDQ ... ...00405 Lyngbya sp. PCC 8106 MPVQQSHYETLLAEYSNAEAAIALLKQHRTYLEMIPSMRRPDESLITIPLPIVRLRDGVSYTGKSGVSITPGQAMCLPCDL

  5. Protein (Cyanobacteria): 69645 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 390 Synechococcus sp. PCC 7335 MDDWLKQLQDEFNTATREASELLEEVAKEAARETERAADQLIEASSLMIDEVDKVIGPAVRSWSDQIDDSLEAGFLYVDQHLTPWIAEVAMPVTHTVNPWLQNHPTCVGCRNYHGTVYGDEMMVCAMHPYGPETDSCRDWESIWPSDQES ...

  6. Prefix list for each organism - Gclust Server | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available ophila melanogaster HSA Homo sapiens SPO Schyzosaccharomyces pombe S99 Synech... 7120 Ava Anabaena variabilis ATCC 29413 Glv Gloeobacter violaceus Npun Nostoc punctiforme sp. PCC73102 Pm1 Proch... Fal Frankia alni ACN14a Fra Frankia sp. CcI3 Gox Gluconobacter_oxydans_621H Hal Halobacterium sp. NRC-1 Mac Methanosarcina ac...hii OT3 Pst Pseudomonas syringae pv. tomato str. DC3000 Rhe Rhizobium_etli_CFN_42 Rle Rhizobium leguminosarum Rso Ralstonia solanac...ococcus sp. CC9902 NCR Neurospora crassa 74-OR23-1A SCE Saccharomyces cerevisiae Joomla SEF URLs by Ar

  7. 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

  8. Comparative growth characterization of frequently used substrains of the model cyanobacterium Synechocystis sp. PCC 6803 under varying culture conditions

    Czech Academy of Sciences Publication Activity Database

    Zavřel, Tomáš; Očenášová, Petra; Sinětova, M. A.; Červený, Jan

    Brno: Global Change Research Centre, The Czech Academy of Sciences, v. v. i., 2015 - (Urban, O.; Šprtová, M.; Klem, K.), s. 154-157 ISBN 978-80-87902-10-3. [Global Change: A Complex Challenge /4th/. Brno (CZ), 23.03.2015-24.03.2015] R&D Projects: GA MŠk(CZ) LO1415; GA MŠk(CZ) ED1.1.00/02.0073; GA MŠk(CZ) EE2.3.20.0256 Institutional support: RVO:67179843 Keywords : growth characterization * cyanobacterium Synechocystis * culture conditions Subject RIV: EH - Ecology, Behaviour

  9. Multi-omics analyses of the molecular physiology and biotechnology of Escherichia coli and Synechocystis sp. PCC6803

    OpenAIRE

    Borirak, O.

    2016-01-01

    The main aim of this thesis was to investigate the physiological response of bacteria responding to physiological- and engineered changes in their central carbon metabolism through the application of multi-omics analyses techniques. The level of the proteome, which is the key functional component of biological systems, and its relationship with its corresponding transcriptome, are the focus of this research. The results described in this thesis have revealed an additional significant layer of...

  10. Biocatalytic role of potato starch synthase III for α-glucan biosynthesis in Synechocystis sp. PCC6803 mutants.

    Science.gov (United States)

    Yoo, Sang-Ho; Lee, Byung-Hoo; Li, Li; Perris, Shayani D N; Spalding, Martin H; Han, Sang Yun; Jane, Jay-lin

    2015-11-01

    A potato starch synthase III (PSSIII) was expressed in the Synechocystis mutants deficient in either glycogen synthase I (M1) or II (M2) to replenish α-(1,4) linkage synthesizing activity, resulting in new mutants, PM1 and PM2, respectively. These mutants were applied to study the role of exogenous plant starch synthase for starch/glycogen biosynthesis mechanism established in the cyanobacteria. The remaining glycogen synthase genes in PM1 and PM2 were further disrupted to make the mutants PM12 and PM21 which contained PSSIII as the sole glycogen/starch synthase. Among wild type and mutants, there were no significant differences in the amount of α-glucan produced. All the mutants harboring active PSSIII produced α-glucans with relatively much shorter and less longer α-1,4 chains than wild-type glycogen, which was exactly in accordance with the increase in glycogen branching enzyme activity. In fact, α-glucan structure of PM1 was very similar to those of PM12 and PM21, and PM2 had more intermediate chains than M2. This result suggests PSSIII may have distributive elongation property during α-glucan synthesis. In conclusion, the Synechocystis as an expression model system of plant enzymes can be applied to determine the role of starch synthesizing enzymes and their association during α-glucan synthesis. PMID:26358554

  11. 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: 2.485, year: 2014

  12. Producción fotosintética de etanol por la cianobacteria Synechocystis sp. PCC 6803

    OpenAIRE

    Vidal Vidal, Rebeca

    2010-01-01

    La preocupación en el ámbito mundial por el calentamiento del planeta, unida al agotamiento de las reservas de petróleo ha generado un gran interés en los últimos años por las fuentes de energía alternativas (Hoffert et al., 2002). Casi una tercera parte de la energía mundial se emplea en el transporte, por lo que los combustibles destinados a este sector constituyen actualmente un objetivo fundamental en las investigaciones destinadas a la reducción de las emisiones de gases de efecto invern...

  13. 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

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

    NARCIS (Netherlands)

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

    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 t

  15. Biomass production and identification of suitable harvesting technique for Chlorella sp. MJ 11/11 and Synechocystis PCC 6803

    OpenAIRE

    Lal, Amrit; Das, Debabrata

    2016-01-01

    Microalgae that can grow fast and convert solar energy into chemical energy efficiently are being considered as a promising feedstock of renewable biofuel. Mass production of microalgal oil faces a number of technical barriers that make the current production of biodiesel economically unfeasible. Small size (≈1–20 μm) and negatively charged surface of the microalgal cells pose difficulties in the process of harvesting. This leads to significant increase in the overall cost of biomass producti...

  16. DNA Probes Show Genetic Variation in Cyanobacterial Symbionts of the Azolla Fern and a Closer Relationship to Free-Living Nostoc Strains than to Free-Living Anabaena Strains

    OpenAIRE

    Plazinski, Jacek; Zheng, Qi; Taylor, Rona; Croft, Lynn; Rolfe, Barry G.; Gunning, Brian E. S.

    1990-01-01

    Twenty-two isolates of Anabaena azollae derived from seven Azolla species from various geographic and ecological sources were characterized by DNA-DNA hybridization. Cloned DNA fragments derived from the genomic sequences of three different A. azollae isolates were used to detect restriction fragment length polymorphism among all symbiotic anabaenas. DNA clones were radiolabeled and hybridized against southern blot transfers of genomic DNAs of different isolates of A. azollae digested with re...

  17. 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...

  18. 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...

  19. Steady state emission of the fluorescent intermediate of Anabaena Sensory Rhodopsin as a function of light adaptation conditions

    Science.gov (United States)

    Cheminal, A.; Léonard, J.; Kim, S. Y.; Jung, K.-H.; Kandori, H.; Haacke, S.

    2013-11-01

    Steady-state fluorescence measurements of the first excited state of the anabaena sensory rhodopsin (ASR), and Bacteriorhodopsin are reported for different light stabilization conditions, including the dark-adapted state. We determine the fluorescence spectra of both all-trans (AT), and 13-cis (13C) protonated Schiff base of retinal, and compare the effect of the proteins. Referenced against the fluorescence quantum yield of AT-bR (2.5 × 10-4) we find for AT-ASR, 13C-ASR, and 13C-bR the values of 3.3 × 10-4, 0.8 × 10-4, and 1.7 × 10-4, respectively. Using reported excited state lifetimes, the radiative rates are deduced, and their differences discussed on the basis of a configuration-dependent oscillator strength.

  20. H2 production by Anabaena variabilis mutant in computer controlled two-stage air-lift tubular photobioreactor

    Science.gov (United States)

    Liu, Jian-Guo; Hall, D. O.; Rao, K. K.; Tsygankov, A. A.; Sveshnikov, D. A.

    2000-06-01

    A 4.34 liter two-stage air-lift photobioreactor incorporating Anabaena variabilis ATCC29413 mutant PK84 was used to study H2 production. Results showed that H2 production increased with increasing light intensity from 47 μE/(m2·s) up to 190 μE/(m2·s), but that further increase of light intensity decreased the H2 production because of the inhibition due to the high pO2. The data also indicated that longer argon gas charge resulted in more H2 produced due to the increase of nitrogenase activities and heterocyst frequency, and that more than 1.3 L net H2 was produced from this computer controlled photobioreactor.

  1. H2 PRODUCTION BY ANABAENA VARIABILIS MUTANT IN COMPUTER CONTROLLED TWO-STAGE AIR-LIFT TUBULAR PHOTOBIOREACTOR

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A 4.34 liter two-stage air-lift photobioreactor incorporating Anabaena variabilis ATCC29413 mutant PK84 was used to study H2 production. Results showed that H2 production increased with increasing light intensity from 47 μE/(m2·s) up to 190 μE/(m2·s), but that further increase of light intensity decreased the H2 production because of the inhibition due to the high pO2. The data also indicated that longer argon gas charge resulted in more H2 produced due to the increase of nitrogenase activities and heterocyst frequency, and that more than 1.3 L net H2 was produced from this computer controlled photobioreactor.

  2. 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

  3. Flexible dynamic operation of solar-integrated power plant with solvent based post-combustion carbon capture (PCC) process

    International Nuclear Information System (INIS)

    Highlights: • Flexible operation of power and PCC plant may significantly increase operational revenue. • Higher optimal carbon capture rates observed with solar thermal energy input. • Solar thermal repowering of the power plant provides highest net revenue. • Constant optimal capture rate observed for one of the flexible operation cases. • Up to 42% higher revenue generation observed between two cases with solar input. - Abstract: This paper examines flexible operation of solvent-based post-combustion carbon capture (PCC) for the reduction of power plant carbon emissions while minimizing revenue loss due to the reduced power plant electricity output. The study is conducted using a model superstructure enveloping three plants; a power plant, a PCC plant and a solar thermal field where the power plant and PCC plant are operated flexibly under the influence of hourly electricity market and weather conditions. Reduced (surrogate) models for the reboiler duty and auxiliary power requirement for the carbon capture plant are generated and applied to simulate and compare four cases, (A) power plant with PCC, (B) power plant with solar assisted PCC, (C) power plant with PCC and solar repowering – variable net electricity output and (D) power plant with PCC and solar repowering – fixed net electricity output. Such analyses are conducted under dynamic conditions including power plant part-load operation while varying the capture rate to optimize the revenue of the power plant. Each case was simulated with a lower carbon price of $25/tonne-CO2 and a higher price of $50/tonne-CO2. The comparison of cases B–D found that optimal revenue generation for case C can be up to 42% higher than that of solar-assisted PCC (case B). Case C is found to be the most profitable with the lowest carbon emissions intensity and is found to exhibit a constant capture rate for both carbon prices. The optimal revenue for case D is slightly lower than case C for the lower carbon

  4. Protein (Cyanobacteria): 464243 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available ein ANA_C10668 Anabaena sp. 90 MCNTSRGASREFWTPNCPFACFWIRFKYDSPLHSYYNICRINLNHSKRFFVVSWHYKIGDSLVALYAIAPQHPQNAIAHNYPNFKRFLGRASLSHPNTPKQRFLGRASLSLTTTLILNELLAAAQRLRSPNLFLNGDSCGALRYRSQPP ...

  5. Protein (Cyanobacteria): 259590 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available NA_C10715 Anabaena sp. 90 MSVGAKHLEDKLSVIAKNSSPNASPVQLSVGAKHLEDKLSVIAKNSSPNASPVQLSVGAKHLEDKLSVIAKNSSPNASPVQLSVGAKHLED...KLSVIAKNSSPNASPVQLSVGAKHLEDKLSVIAKNSSPNASPVQLSVGAKHLEDKLSVIAKNSSPNASPVQLSVGAKHLEDKLSVIAKNSSPNASPVQLSVGAKHLEDKLSVIAKNSSLNASPVQLSVGRNIPPAPCLFCLLL ...

  6. Protein (Cyanobacteria): 259591 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available NA_C20136 Anabaena sp. 90 MVTKFDHNLVVSENVELVNCQLLVGAKHLEDKLSVIAKNSSPNASPVQLLVGAKHLEDKLSVIAKNSSPNASPVQLLVGAKHLED...KLSVIAKNSSANASPVQLLVGAKHLEDKLSVIAKNSSANASPVQLLVGAKHLEDKLSVIAKNSSANASPVQLLVGAKHLEDKLSVIAKNSSANASPVQLLVGAKHLEDKLSVIAKNSSANASPVQLSVAKKYFSSLFPVP ...

  7. Protein (Cyanobacteria): 378103 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available SNAFLGKLDNLFQDLEKQYHNKGIPIKGSIEVKFHKNLFSPIGYYSDSKDCRIAWMYFSHSNGGEYPAFHIGGQELMDDTDNHFEYLWKEAGALLIRITKDPTSSLHDIDIIRSFSNQNQN ... ...AAITIFVLDIGLKRETLEQIQDIINNAKPTRYLKEFFRHKKDYDDLIKNSFNAAIEGQEIRILCLFENEISIFAGSQDLKNIREKIVDGCKLKILILHPESSLLDCLYQSGLARKNNFPLI...tein ANA_C13465 Anabaena sp. 90 MLSKTNKNRFLQLITSTGSKVFKLLFLLGFFGVVLQVTDSYYLQPQCRQQSNPNQQSWKCSIGSPLLGGLGSNFLQ

  8. Protein (Cyanobacteria): 259589 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available NA_C10076 Anabaena sp. 90 MRFYLSVVSCQLSVGAKHLEGKLSVIAKNSSPNASPVQLSVGAKHLEDKLSVIAKNSSPNASPVQLSVGAKHLEDKLSVIAKNSSPNASPV...QLSVGAKHLEDKLSVIAKNSSPNASPVQLSVGAKHLEDKLSVIAKNSSPNASPVQLSVVRIKKEELKRFPCSLFPVIRKVFNC ...

  9. Growth response of Spirulina platensis PCC9108 to elevated CO2 levels and flue gas

    Directory of Open Access Journals (Sweden)

    Seyedmahdi Hoseini

    2014-01-01

    Full Text Available Introduction: Because their ability to capture CO2, photosynthetical microorganisms have some advantages to CO2 mitigation from high CO2 streams such as flue gases and they can use CO2 as carbon source. Recently, experts have made efforts to exploit microorganisms intended for recovering CO2 from power plants. Materials and methods: To achieve this purpose, we studied the growth response of the cyanobacterium Spirulina platensis PCC9108 under different concentrations of carbon dioxide (ranging from 0.036% to 10% and flue gas in a bench-scale system. Preparation of different concentrations of CO2 and injection into Erlenmeyer flasks was performed by a system including air compressor, CO2 capsule, pressure gauge and flow meter. Results: The main goal of studying this paper is a survey of organism's potential to grow by generated CO2 from flue gas of power plant. It already had the potential and highest biomass production recorded at 8% CO2 (v/v. Also we proved that S.platensis PCC9108 can be grown under flue gas, although biomass production decreased fairly. Total lipid content of algae interestingly enhanced with elevated CO2 levels from ambient air to 4% and 6% which ranged from 14.5 to 15.8 and 16 dry weight (wt. % respectively. In contrast, total protein content illustrated no difference between all treatment and its value was about 46 wt.%. Discussion and conclusion: The results of present study suggested that understudied S.platensis PCC9108 is appropriate for mitigating CO2 because of its carbon fixation ability. Also due to its high protein content, this cyanobacterium is a good candidate to produce SCP (single cell protein.

  10. Azolla-Anabaena as a Biofertilizer for Rice Paddy Fields in the Po Valley, a Temperate Rice Area in Northern Italy

    OpenAIRE

    Stefano Bocchi; Antonino Malgioglio

    2010-01-01

    Azolla is a floating pteridophyte, which contains as endosymbiont the nitrogen-fixing cyanobacterium Anabaena azollae (Nostocaceae family). Widely cultivated in the Asian regions, Azolla is either incorporated into the soil before rice transplanting or grown as a dual crop along with rice. To examine the feasibility of its use in flooded rice fields sited in the Temperate European Areas, we carried out a series of experiments in PVC tanks during 2000–2002 in Po Valley (northern Italy) conditi...

  11. Alterations in proteins and amino acids of the Nile cyanobacteria Pseudanabaena limnetica and Anabaena wisconsinense in response to industrial wastewater pollution

    OpenAIRE

    Mostafa Mohamed El-Sheekh; Ahmed Mohamed El-Otify; Hani Saber

    2011-01-01

    The effect of industrial wastewater on the Nile cyanobacteria Pseudanabaena limnetica and Anabaena wisconsinense was investigated. The data showed that P. limnetica was more sensitive to pollution than A. wisconsinense. The treatments with different levels of wastewater exerted pronounced reductions in protein and amino acids content. SDS-PAGE analysis revealed that the cyanobacteria grown in the industrial wastewater showed induction in the synthesis of certain polypeptides and repression of...

  12. Detection of Anatoxin-a and Three Analogs in Anabaena spp. Cultures: New Fluorescence Polarization Assay and Toxin Profile by LC-MS/MS

    OpenAIRE

    Sanchez, Jon A.; Paz Otero; Amparo Alfonso; Vitor Ramos; Vitor Vasconcelos; Romulo Aráoz; Jordi Molgó; Vieytes, Mercedes R.; Botana, Luis M.

    2014-01-01

    Anatoxin-a (ATX) is a potent neurotoxin produced by several species of Anabaena spp. Cyanobacteria blooms around the world have been increasing in recent years; therefore, it is urgent to develop sensitive techniques that unequivocally confirm the presence of these toxins in fresh water and cyanobacterial samples. In addition, the identification of different ATX analogues is essential to later determine its toxicity. In this paper we designed a fluorescent polarization (FP) method to detect ...

  13. PAPR Reduction for PCC-OFDM Systems Using Neural Phase Rotator

    Science.gov (United States)

    Ohta, Masaya; Yamada, Hideyuki; Yamashita, Katsumi

    This paper proposes a novel Orthogonal frequency-division multiplexing (OFDM) system based on polynomial cancellation coded OFDM (PCC-OFDM). This proposed system can reduce peak-to-average power ratio (PAPR) by our neural phase rotator and it does not need any side information to transmit phase rotation factors. Moreover, this system can compensate the common phase error (CPE) by a proposed technique which allows estimating frequency offset at receiver. From numerical experiments, it is shown that our system can reduce PAPR and ICI at the same time and improve BER performance effectively.

  14. El PCC com a document de canvi i d'innovació als centres educatius de primària

    OpenAIRE

    Martínez Mínguez, Maria Lourdes

    2000-01-01

    Consultable des del TDX Títol obtingut de la portada digitalitzada Aquesta tesi pretén: establir quina és la situació real dels Projectes Curriculars de Centre (PCC) a les escoles d'Educació Infantil i Primària de Catalunya; comprovar si el PCC ha estat un instrument de canvi i d'innovació; i configurar propostes per facilitar i redreçar l'elaboració, aplicació i avaluació dels PCC. Per aconseguir aquests propòsits s'ha partit d'una recerca bibliogràfica i documental que ha permès dispo...

  15. Surface modification of PCC with guar gum using organic titanium ionic crosslinking agent and its application as papermaking filler.

    Science.gov (United States)

    Xie, Wei; Song, Zhanqian; Liu, Zhenhua; Qian, Xueren

    2016-10-01

    Utilized the principles of guar gum (GG) gelation and crosslinking, a novel modified precipitated calcium carbonate (MPCC) papermaking filler was prepared by using organic titanium (OT) ionic crosslinking agent. The MPCC was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). FTIR results confirmed that GG had been coated on the surface of PCC particles, XPS analysis indicated the presence of titanium atoms on MPCC particles, and SEM and XRD results showed that the modification treatment did change the surface morphology and crystal structure of PCC particles. The handsheet testing results showed that the strength properties of handsheets were obviously improved when using MPCC as papermaking filler, and the optimum preparation conditions of MPCC were obtained. This research suggests that the GG modified PCC by using OT as crosslinking agent can be used to manufacture high filler content paper products. PMID:27312620

  16. Purification, crystallization and preliminary X-ray diffraction of fluorescence recovery protein from Synechocystis PCC 6803

    International Nuclear Information System (INIS)

    Fluorescence recovery protein from Synechocystis PCC 6803 plays a key role in the orange carotenoid protein-related photoprotective mechanism in cyanobacteria. The full-length form and a truncated form were overexpressed, purified and crystallized, and diffraction was observed to 2.75 Å resolution. Fluorescence recovery protein (FRP), which is encoded by the slr1964 gene in Synechocystis PCC 6803, plays a key role in the orange carotenoid protein-related photoprotective mechanism in cyanobacteria. As the crystal structure of FRP may provide information about the biological functions and mechanism of action of the protein, recombinant full-length FRP and a truncated form were overexpressed, purified and crystallized at 291 K using ethylene imine polymer as the precipitant. An FRP data set was collected to a resolution of 2.75 Å at low temperature (100 K). The crystal belonged to space group P41212, with unit-cell parameters a = b = 61.9, c = 160.7 Å, α = β = γ = 90°. Assuming that the asymmetric unit contains three molecules, the Matthews coefficient was calculated to be 2.1 Å3 Da−1

  17. Ammonium nitrogen removal in batch cultures treating digested piggery wastewater with microalgae Oedogonium sp.

    Science.gov (United States)

    Wang, Haiping; Hu, Zhiquan; Xiao, Bo; Cheng, Qunpeng; Li, Fanghua

    2013-01-01

    Due to the nutrient characteristics of the high concentration of available ammonium in digested piggery wastewater (DPW), microalgae can be used to treat DPW before its final discharge. Four green microalgae (Hydrodictyaceae reticulatum Lag, Scenedesmus obliquus, Oedogonium sp. and Chlorella pyrenoidosa) and three blue-green algae (Anabaena flos-aquae, Oscillatoria amoena Gom and Spirulina platensis) were used to remove the nutrients (N, P, C), especially ammonium nitrogen (NH4(+)-N), from diluted DPW with 300 mg/L algae density in batch tests. The microalgae with the best NH4(+)-N nutrient removal was then selected for further optimization of the variables to improve NH4(+)-N removal efficiency using a central composite design (CCD) experiment. Taking into account the nutrient removal efficiency, Oedogonium sp. showed the best performance (reduction of 95.9% NH4(+)-N, 92.9% total phosphorus (TP) and 62.5% chemical oxygen demand (COD)) based on the results of the batch tests. The CCD results suggested that the optimal values of variables were initial Oedogonium sp. density of 399.2 mg/L and DPW diluted by 16.3, while the predicted value of NH4(+)-N removal efficiency obtained was 97.0%. PMID:23863416

  18. 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 disp

  19. Techniques for induction of premature chromosome condensation (PCC) by Calyculin-A and micronucleus assay for biodosimetry in Vietnam

    International Nuclear Information System (INIS)

    The International Atomic Energy Agency (IAEA) and World Health Organization are interested in biological dosimetry method for radiation emergency medicine currently. Some cytogenetic techniques such as premature chromosome condensation (PCC) induced by Calyculin-A and micronucleus (MN) assay are necessary to develop biodosimetry in Vietnam. In this study, we optimized the condition for MN assay with 6 µg/ml Cytochalasin-B concentration and 72.5 hours for peripheral lymphocyte blood culture. The optimization for PCC method is 50 nM Calyculin-A concentration for 45 minutes peripheral lymphocyte blood treatment. For samples exposed to 3.0 Gy gamma 60Co (dose rate 0.0916 Gy/s), the frequency of MN is 19.02 ± 0.38%, NBP is 1.95 ± 0.28%, dicentric and ring is 41.43 ± 8.12% and frag and min is 63.33 ± 5.16%. For samples exposed to 6.0 Gy gamma 60Co (dose rate 0.0916 Gy/s), the frequency of ring-PCC is 17.73 ± 2.46%, extra unite is 218.91± 7.58%, dicentric is 83.81 ± 1.09%, ring is 10.75 ± 1.74%, fragment and minute is 193.17 ± 13.10%. MN and ring-PCC are specific marker applying for biodosimetry. (author)

  20. Advanced solid-state NMR techniques for characterization of membrane protein structure and dynamics: Application to Anabaena Sensory Rhodopsin

    Science.gov (United States)

    Ward, Meaghan E.; Brown, Leonid S.; Ladizhansky, Vladimir

    2015-04-01

    Studies of the structure, dynamics, and function of membrane proteins (MPs) have long been considered one of the main applications of solid-state NMR (SSNMR). Advances in instrumentation, and the plethora of new SSNMR methodologies developed over the past decade have resulted in a number of high-resolution structures and structural models of both bitopic and polytopic α-helical MPs. The necessity to retain lipids in the sample, the high proportion of one type of secondary structure, differential dynamics, and the possibility of local disorder in the loop regions all create challenges for structure determination. In this Perspective article we describe our recent efforts directed at determining the structure and functional dynamics of Anabaena Sensory Rhodopsin, a heptahelical transmembrane (7TM) protein. We review some of the established and emerging methods which can be utilized for SSNMR-based structure determination, with a particular focus on those used for ASR, a bacterial protein which shares its 7TM architecture with G-protein coupled receptors.

  1. Primary structural response in tryptophan residues of Anabaena sensory rhodopsin to photochromic reactions of the retinal chromophore

    Science.gov (United States)

    Inada, Seisuke; Mizuno, Misao; Kato, Yoshitaka; Kawanabe, Akira; Kandori, Hideki; Wei, Zhengrong; Takeuchi, Satoshi; Tahara, Tahei; Mizutani, Yasuhisa

    2013-06-01

    Anabaena sensory rhodopsin (ASR) is a microbial rhodopsin found in eubacteria and functions as a photosensor. The photoreaction of ASR is photochromic between all-trans, 15-anti (ASRAT), and 13-cis, 15-syn (ASR13C) isomers. To understand primary protein dynamics in the photoreaction starting in ASRAT and ASR13C, picosecond time-resolved ultraviolet resonance Raman spectra were obtained. In the intermediate state appearing in the picosecond temporal region, spectral changes of Trp bands were observed. For both ASRAT and ASR13C, the intensities of the Trp bands were bleached within the instrumental response time and recovered with a time constant of 30 ps. This suggests that the rates of structural changes in the Trp residue in the vicinity of the chromophore do not depend on the direction of the isomerization of retinal. A comparison between spectra of the wild-type and Trp mutants indicates that the structures of Trp76 and Trp46 change upon the primary photoreaction of retinal.

  2. Integrated membrane systems incorporating coagulation, activated carbon and ultrafiltration for the removal of toxic cyanobacterial metabolites from Anabaena circinalis.

    Science.gov (United States)

    Dixon, M B; Richard, Y; Ho, L; Chow, C W K; O'Neill, B K; Newcombe, G

    2011-01-01

    The use of integrated membrane systems (a train of treatment processes incorporating one or more membranes) is increasing globally as the technology is very effective for the production of high quality drinking water. In this investigation a laboratory scale integrated membrane system (IMS) featuring coagulation, powdered activated carbon (PAC) and ultrafiltration (UF) was investigated for the removal of an Australian strain of the cyanobacteria Anabaena circinalis and the cyanotoxin it produced. Three coagulants were compared, aluminium chlorohydrate (ACH), aluminium sulphate (alum) and an engineered aluminium coagulant referred to as high performance aluminium chlorohydrate (HPAC). PAC (Acticarb PS1000) was tested to determine adsorption of extracellular saxitoxin. Removal of A. circinalis cells was 100% by UF alone and the removal of cells prior to the membrane by coagulation reduced fouling attributed to algogenic organic material. Alum was the least efficient coagulant for removal of cells while ACH and HPAC were similar. Saxitoxin removal reached a maximum of 80% using ACH and PAC. The UF-IMS was challenged using a natural bloom of A. circinalis that occurred in the Myponga Reservoir in South Australia. PMID:21508543

  3. Advanced solid-state NMR techniques for characterization of membrane protein structure and dynamics: application to Anabaena Sensory Rhodopsin.

    Science.gov (United States)

    Ward, Meaghan E; Brown, Leonid S; Ladizhansky, Vladimir

    2015-04-01

    Studies of the structure, dynamics, and function of membrane proteins (MPs) have long been considered one of the main applications of solid-state NMR (SSNMR). Advances in instrumentation, and the plethora of new SSNMR methodologies developed over the past decade have resulted in a number of high-resolution structures and structural models of both bitopic and polytopic α-helical MPs. The necessity to retain lipids in the sample, the high proportion of one type of secondary structure, differential dynamics, and the possibility of local disorder in the loop regions all create challenges for structure determination. In this Perspective article we describe our recent efforts directed at determining the structure and functional dynamics of Anabaena Sensory Rhodopsin, a heptahelical transmembrane (7TM) protein. We review some of the established and emerging methods which can be utilized for SSNMR-based structure determination, with a particular focus on those used for ASR, a bacterial protein which shares its 7TM architecture with G-protein coupled receptors. PMID:25637099

  4. 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.

  5. Serotonin Transporter Genotype Modulates Functional Connectivity between Amygdala and PCC/PCu during Mood Recovery

    Directory of Open Access Journals (Sweden)

    Zhuo eFang

    2013-10-01

    Full Text Available The short (S allele of the serotonin transporter-linked polymorphic region (5-HTTLPR has been associated with increased susceptibility to depression. Previous neuroimaging studies have consistently showed increased amygdala activity during the presentation of negative stimuli or regulation of negative emotion in the homozygous short allele carriers, suggesting the key role of amygdala response in mediating increased risk for depression. The default brain network (DMN has also been shown to modulate amygdala activity. However, it remains unclear whether 5-HTTLPR genetic variation modulates functional connectivity between the amygdala and regions of DMN. In this study, we re-analyzed our previous imaging dataset and examined the effects of 5-HTTLPR genetic variation on amygdala connectivity. A total of 15 homozygous short (S/S and 15 homozygous long individuals (L/L were scanned in functional MRI during four blocks: baseline, sad mood, mood recovery, and return to baseline. The S/S and L/L groups showed a similar pattern of functional connectivity and no differences were found between the two groups during baseline and sad mood scans. However, during mood recovery, the S/S group showed significantly reduced anti-correlations between amygdala and posterior cingulate cortex/precuneus (PCC/PCu compared to the L/L group. Moreover, PCC/PCu-amygdala connectivity correlated with amygdala activity in the S/S group but not the L/L group. These results suggest that 5-HTTLPR genetic variation modulates amygdala connectivity which subsequently affects its activity during mood regulation, providing an additional mechanism by which the S allele confers depression risk.

  6. 4-Factor Prothrombin Complex Concentrate (PCC4, Kcentra®) Protocol Reduces Blood Requirements for Heart Transplantation: A Novel Protocol.

    Science.gov (United States)

    Pratt Cleary, Jacqueline; Hodge, Laura; Palmer, Brittany; Barreiro, Christopher J; Ingemi, Amanda

    2016-01-01

    BACKGROUND All patients with a ventricular assist device (VAD) awaiting heart transplantation are anticoagulated with warfarin to prevent thromboembolism. The use of 4 factor prothrombin complex concentrate (PCC4, Kcentra®) for anticoagulation reversal prior to surgery may include benefits such as quicker reversal, longer duration of action, and a reduction in total volume of blood products used compared to other reversal practices. The study objective is to evaluate benefits of using an anticoagulation reversal protocol featuring PCC4, over standard of care in heart transplant patients requiring anticoagulation. MATERIAL AND METHODS This is a single center, combined retrospective and prospective, time-matched cohort study compared 12 patients transplanted pre-protocol and 11 patients transplanted post-protocol. The primary outcome was the total volume of blood and blood products used. Secondary outcomes included length of hospital and ICU stay, safety and adverse events, primary chest closure, and a cost comparison. RESULTS The PCC4 reversal protocol showed a significant reduction in total blood volume received with an overall decrease of 1.76L (4.20L pre-protocol, 2.45L post-protocol, P=0.037), total units of blood products infused (20 units pre, 12 units post, P=0.033), and units of packed red blood cells (7 units pre, 3 units post, P=0.033). All heart transplant recipients were listed Status 1A with the primary indication being infection (n=12; 52%). Baseline characteristics, survival, and cost were not different between the two groups. There were no thrombotic events or patient that experienced serious reactions to PCC4. Secondary outcomes were only significant to time to INR reversal. CONCLUSIONS Patients treated with the PCC4 protocol demonstrated a significant decrease in volume of blood and units of blood products required prior to chest closure for heart transplant patients. PCC4 was found to be a safe and beneficial agent in anticoagulation reversal for

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

    Science.gov (United States)

    Vass, István-Zoltán; Kós, Péter B; Knoppová, Jana; Komenda, Josef; Vass, Imre

    2014-01-01

    The role of the Syn-CRY cryptochrome from the cyanobacterium Synechocystis sp. PCC 6803 has been a subject of research for more than a decade. Recently we have shown that photolyase, showing strong homology with Syn-CRY is required for Photosystem II repair by preventing accumulation of DNA lesions under UV-B (Vass et al. 2013). Here we investigated if Syn-CRY is also involved in PSII repair, either via removal of DNA lesions or other mechanism? The Δsll1629 mutant lacking Syn-CRY lost faster the PSII activity and D1 protein during UV-B or PAR than the WT. However, no detectable damages in the genomic DNA were observed. The transcript levels of the UV-B and light stress indicator gene psbA3, encoding D1, are comparable in the two strains showing that Δsll1629 cells are not defective at the transcriptional level. Nevertheless 2D protein analysis in combination with mass spectrometry showed a decreased accumulation of several, mostly cytoplasmic, proteins including PilA1 and bicarbonate transporter SbtA. Δsll1629 cells exposed to high light also showed a limitation in de novo assembly of PSII. It is concluded that Syn-CRY is required for efficient restoration of Photosystem II activity following UV-B and PAR induced photodamage. This effect is not caused by retardation of DNA repair, instead the synthesis of new D1 (and D2) subunit(s) and/or the assembly of the Photosystem II reaction center complex is likely affected due to the lack of intracellular CO2, or via a so far unidentified pathway that possibly includes the PilA1 protein. PMID:24389045

  8. The structure of allophycocyanin B from Synechocystis PCC 6803 reveals the structural basis for the extreme redshift of the terminal emitter in phycobilisomes.

    Science.gov (United States)

    Peng, Pan Pan; Dong, Liang Liang; Sun, Ya Fang; Zeng, Xiao Li; Ding, Wen Long; Scheer, Hugo; Yang, Xiaojing; Zhao, Kai Hong

    2014-10-01

    Allophycocyanin B (AP-B) is one of the two terminal emitters in phycobilisomes, the unique light-harvesting complexes of cyanobacteria and red algae. Its low excitation-energy level and the correspondingly redshifted absorption and fluorescence emission play an important role in funnelling excitation energy from the hundreds of chromophores of the extramembraneous phycobilisome to the reaction centres within the photosynthetic membrane. In the absence of crystal structures of these low-abundance terminal emitters, the molecular basis for the extreme redshift and directional energy transfer is largely unknown. Here, the crystal structure of trimeric AP-B [(ApcD/ApcB)3] from Synechocystis sp. PCC 6803 at 1.75 Å resolution is reported. In the crystal lattice, eight trimers of AP-B form a porous, spherical, 48-subunit assembly of 193 Å in diameter with an internal cavity of 1.1 × 10(6) Å(3). While the overall structure of trimeric AP-B is similar to those reported for many other phycobiliprotein trimers, the chromophore pocket of the α-subunit, ApcD, has more bulky residues that tightly pack the phycocyanobilin (PCB). Ring D of the chromophores is further stabilized by close interactions with ApcB from the adjacent monomer. The combined contributions from both subunits render the conjugated rings B, C and D of the PCB in ApcD almost perfectly coplanar. Together with mutagenesis data, it is proposed that the enhanced planarity effectively extends the conjugation system of PCB and leads to the redshifted absorption (λmax = 669 nm) and fluorescence emission (679 nm) of the ApcD chromophore in AP-B, thereby enabling highly efficient energy transfer from the phycobilisome core to the reaction centres. PMID:25286841

  9. Conformational dynamics of a seven transmembrane helical protein Anabaena Sensory Rhodopsin probed by solid-state NMR.

    Science.gov (United States)

    Good, Daryl B; Wang, Shenlin; Ward, Meaghan E; Struppe, Jochem; Brown, Leonid S; Lewandowski, Józef R; Ladizhansky, Vladimir

    2014-02-19

    The ability to detect and characterize molecular motions represents one of the unique strengths of nuclear magnetic resonance (NMR) spectroscopy. In this study, we report solid-state NMR site-specific measurements of the dipolar order parameters and (15)N rotating frame spin-lattice (R1ρ) relaxation rates in a seven transmembrane helical protein Anabaena Sensory Rhodopsin reconstituted in lipids. The magnitudes of the observed order parameters indicate that both the well-defined transmembrane regions and the less structured intramembrane loops undergo restricted submicrosecond time scale motions. In contrast, the R1ρ rates, which were measured under fast magic angle spinning conditions, vary by an order of magnitude between the TM and exposed regions and suggest the presence of intermediate time scale motions. Using a simple model, which assumes a single exponential autocorrelation function, we estimated the time scales of dominant stochastic motions to be on the order of low tens of nanoseconds for most residues within the TM helices and tens to hundreds of nanoseconds for the extracellular B-C and F-G loops. These relatively slow time scales could be attributed to collective anisotropic motions. We used the 3D Gaussian axial fluctuations model to estimate amplitudes, directions, and time scales of overall motions for helices and the extracellular B-C and F-G loops. Within this model, the TM helices A,B,C,D,E,F undergo rigid body motions on a time scale of tens of nanoseconds, while the time scale for the seventh helix G approaches 100 ns. Similar time scales of roughly 100-200 ns are estimated for the B-C and F-G loops. PMID:24467417

  10. Cyclic nucleotide binding and structural changes in the isolated GAF domain of Anabaena adenylyl cyclase, CyaB2

    Directory of Open Access Journals (Sweden)

    Kabir Hassan Biswas

    2015-04-01

    Full Text Available GAF domains are a large family of regulatory domains, and a subset are found associated with enzymes involved in cyclic nucleotide (cNMP metabolism such as adenylyl cyclases and phosphodiesterases. CyaB2, an adenylyl cyclase from Anabaena, contains two GAF domains in tandem at the N-terminus and an adenylyl cyclase domain at the C-terminus. Cyclic AMP, but not cGMP, binding to the GAF domains of CyaB2 increases the activity of the cyclase domain leading to enhanced synthesis of cAMP. Here we show that the isolated GAFb domain of CyaB2 can bind both cAMP and cGMP, and enhanced specificity for cAMP is observed only when both the GAFa and the GAFb domains are present in tandem (GAFab domain. In silico docking and mutational analysis identified distinct residues important for interaction with either cAMP or cGMP in the GAFb domain. Structural changes associated with ligand binding to the GAF domains could not be detected by bioluminescence resonance energy transfer (BRET experiments. However, amide hydrogen-deuterium exchange mass spectrometry (HDXMS experiments provided insights into the structural basis for cAMP-induced allosteric regulation of the GAF domains, and differences in the changes induced by cAMP and cGMP binding to the GAF domain. Thus, our findings could allow the development of molecules that modulate the allosteric regulation by GAF domains present in pharmacologically relevant proteins.

  11. The PCC assay can be used to predict radiosensitivity in biopsy cultures irradiated with different types of radiation.

    Science.gov (United States)

    Suzuki, Masao; Tsuruoka, Chizuru; Nakano, Takashi; Ohno, Tatsuya; Furusawa, Yoshiya; Okayasu, Ryuichi

    2006-12-01

    The aim of this study was to identify potential biomarkers for radiosensitivity using the relationship between cell killing and the yield of excess chromatin fragments detected with the premature chromosome condensation (PCC) technique. This method was applied to primary cultured cells obtained from biopsies from patients. Six primary culture biopsies were obtained from 6 patients with carcinoma of the cervix before starting radiotherapy. The cultures were irradiated with two different LET carbon-ion beams (LET = 13 keV/microm, 77.1+/-2.8 keV/microm) and 200 kV X-rays. The carbon-ion beams were produced by Heavy Ion Medical Accelerator in Chiba (HIMAC). PCC was performed using the polyethylene glycol-mediated cell fusion technique. The yield of excess chromatin fragments were measured by counting the number of unrejoined chromatin fragments detected with the PCC technique after a 24-h post-irradiation incubation period. Obtained results indicated that cultures which were more sensitive to killing were also more susceptible to the induction of excess chromatin fragments. Furthermore there was a good correlation between cell killing and excess chromatin fragments among the 6 cell cultures examined. There is also evidence that the induction of excess chromatin fragments increased with increasing LET as well as cell-killing effect in the same cell culture. The data reported here support the idea that the yield of excess chromatin fragments detected with the PCC technique might be useful for predicting the radiosensitivity of cells contained in tumor tissue, and to predict responses to different radiation types. PMID:17089052

  12. Photodegradation of 17α-ethynylestradiol in Aqueous Solution with Anabaena HB101%含鱼腥藻水溶液中17α-乙炔雌二醇光降解

    Institute of Scientific and Technical Information of China (English)

    刘先利; 邓南圣; 徐栋; 邓琳

    2003-01-01

    研究了含鱼腥藻Anabaena HB101水溶液中17α-乙炔雌二醇在250W高压汞灯光照下的光降解,并进行了动力学分析,研究结果表明,水溶液中鱼腥藻Anabaena HB101能促进17α-乙炔雌二醇光降解,随着水溶液中鱼腥藻Anabaena HB101的浓度增大,其光降解效率也增大,表明了鱼腥藻对17α-乙炔雌二醇光降解有明显的催化作用.同时也研究了在紫外光下的光降解情况,结果表明其光降解效率比高压汞灯光照下的光降解效率高,总体上讲,藻具有催化光降解作用.探讨分析了鱼腥藻Anabaena HB101催化17α-乙炔雌二醇光降解的作用与机理.

  13. Heavy ion-induced chromosome breakage studied by premature chromosome condensation (PCC) in Syrian hamster embryo cells

    International Nuclear Information System (INIS)

    The authors studied induction and repair of chromosome damage induced by high linear energy transfer (LET) heavy ions in G1/Go interphase Syrian golden hamster embryo (SHE) cells as revealed by the premature chromosome condensation (PCC) technique. The number of chromosome breaks in condensed chromosomes induced by high LET heavy ions was higher than those induced by 137Cs gamma-rays. Compared with 137 Cs gamma rays, the relative biological effectiveness (RBE) for PCC breaks was 1.5 for 35 keV/μm, 4He ions, 1.9 for 77 keV/μm 4He ions, and 2.5 for 530 keV/μm 14N ions. Although 95% of PCC breaks induced by gamma-rays rejoined during 8 h post-irradiation incubation, only 35-45% of fragments induced by high LET radiations rejoined in the same time. Results suggest that there is a difference, spatial or qualitative in the initial chromosome damage produced by high and low LET radiations. (Author)

  14. Using a Microfluidic Gradient Generator to Characterize BG-11 Medium for the Growth of Cyanobacteria Synechococcus elongatus PCC7942

    Directory of Open Access Journals (Sweden)

    Chih-Chun Yang

    2015-11-01

    Full Text Available The photosynthetic cyanobacterium Synechococcus elongatus PCC7942 has recently gained great attention for its ability to directly convert CO2 into renewable chemicals upon genetic engineering. Thus, it is of great interest to increase the growth speed and lower the medium requirement for cultivating this cyanobacterium. The cultivation medium of Synechococcus elongatus PCC7942 has been developed, which consists of many inorganic and metal ingredients with a specific composition, known as the BG-11 medium. In this work, we analyzed the concentration effect of each ingredient and identified the absolutely essential components in BG-11 medium for cyanobacteria growth using the concentration gradient generator chip (CGGC fabricated by MEMS technology. As shown by our results, removal of the individual component sodium nitrate, potassium phosphate, or magnesium sulfate from the BG-11 medium led to severe growth inhibition of Synechococcus elongatus PCC7942. Contrary to our expectation, increasing concentration of the crucial ingredients showed either insignificant or negative impact on cell growth. Overall, standard growth could be achieved without supplementation of ethylenediaminetetraacetic acid (EDTA disodium, sodium carbonate, or sodium citrate to the culture medium. Further improvement of the CGGC-based microfluidic system based on this preliminary study may broaden its application range to analyze more complicated correlations.

  15. Control of Branchionus sp. and Amoeba sp. in cultures of Arthrospira sp. Control de Branchionus sp. y Amoeba sp. en cultivos de Arthrospira sp.

    OpenAIRE

    Carlos Méndez; Eduardo Uribe

    2012-01-01

    Cultivation of cyanobacterium Arthrospira sp. has been developed in many countries for the production of proteins, pigments and other compounds. Outdoor mass cultures are often affected by biological contamination, drastically reducing productivity as far as bringing death. This study evaluates the control of Branchionus sp. and Amoeba sp. with two chemical compounds: urea (U) and ammonium bicarbonate (AB), in laboratory conditions and outdoor mass culture of Arthrospira sp. The lethal concen...

  16. Protein (Cyanobacteria): 243052 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available FGESIVDHLFQSLELVLSGISKYLPNAFIIAIIIFLTYYLIRIIKPFFTAIERGNLVIPGFYTDWAKPTYNLLLFIIIALAAVLAFPYLPGFDSPAFRGISVFLGLLLSLGSTSAITNVIGGIILI...YTRAFQIGDHIQVGDVIGDIIEKNFLVIRICTPTNQIITIPNSSLLISNVINYSISSRELNKYLILQTTITLGYDVPWQKVYSTLIEAALNTEHIL...N_2652 Synechocystis sp. PCC 6803 substr. PCC-N MKRIGHMLVTFTIFLLLVLTIPTVGVAQNSAQSGVLQSQTQTENAIDGFPVTLDGRPIFFIRRGVSSFSAEDRANAITQRIKRIA...QNYSIALENLKIAPNPYDNSLYLSLDKEVILTITEQDARAYFSTPEVLARDALQSIKDAIEQYRQARRPEQLLRNIIYTAIASFAFLSTVFLI...IKLSGKLFPWFRALIEFHVPGIKIQNAEIISSSKISFLGLRILQIIRLVFLLLLLFSYVAFVLRLFPWTKV

  17. Protein (Cyanobacteria): 255568 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available QQYIEAYLAKAESQWTALAPDQLQAIAAHIKECDFPELVATMAEIGQKVGFIPPQVLFTEPRGFHHCFAFAISQSGKALAQDGV ... ...N_2350 Synechocystis sp. PCC 6803 substr. PCC-N MASSPRPTEQTKQFFQQWQTYQQLVDHNYMAHRQIHQAVGALIQQQFDRPFDFLDLGCGD...AQAIAKTLTGSKINSYTGVDLSPNALALAQKNLDPFRQVELRETDFLTYLGEANQTAPASFDLIHVGFSLHHLLPEEKEQFFAHCFSLLRPGGCLVIYDVFRQPEQNR

  18. Protein (Cyanobacteria): 255567 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available QQYIEAYLAKAESQWTALAPDQLQAIAAHIKECDFPELVATMAEIGQKVGFIPPQVLFTEPRGFHHCFAFAISQSGKALAQDGV ... ...P_2350 Synechocystis sp. PCC 6803 substr. PCC-P MASSPRPTEQTKQFFQQWQTYQQLVDHNYMAHRQIHQAVGALIQQQFDRPFDFLDLGCGD...AQAIAKTLTGSKINSYTGVDLSPNALALAQKNLDPFRQVELRETDFLTYLGEANQTAPASFDLIHVGFSLHHLLPEEKEQFFAHCFSLLRPGGCLVIYDVFRQPEQNR

  19. Effect of Cl- on photosynthetic bicarbonate uptake in two cyanobacteria Microcystis aeruginosa and Synechocystis PCC6803

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhen; CHENG HuiMin; CHEN XiongWen

    2009-01-01

    Photosynthetic inorganic carbon utilization was investigated in two cyanobacteria Microcystis aeruginosa and Synechocystis PCC6803 grown in standing culture. Photosynthetic rates for the two algae reached about 10 times the theoretical CO2 supply rate at low dissolved inorganic carbon (DIC) of 100 μmol/L, and the rates were unaffected by the addition of 20 mmol/L Na+, indicating that the two algae possessed Na+-independent HCO3- utilization for photosynthesis under low DIC. Their photo-synthetic rates at low DIC were inhibited by higher Cl-and the degrees of inhibition were increased with the rise of Cl- concentration, and in the presence of Diphenylamine-2-carboxylate (DPC), a reported Cl-channel inhibitor, the rates decreased by 74%-82%, implying that putative DPC-sensitive Cl- channels participate In Na+-indepandent HCO3- uptake for photosynthesis. The experiment of intracellular 14C-DIC accumulation for photosynthesis showed that internal DIC pools decreased by about 80% with 200 pmol/L DPC and by 64%-70% with 100 mmol/L Cl-. The experiment of chlorophyll a fluorescence quenching showed that initial rates and extents of fluorescence quenching obviously decreased with 200 μmol/L DPC or 100 mmol/L Cl-. The two experiments gave further evidence that putative DPC-sen-sitive Cl- channels participate in Na+-independent HCO3- uptake for photosynthesis in the two algae grown in standing culture.

  20. 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.

  1. 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.

  2. Structural and enzymatic analyses of a glucosyltransferase Alr3699/HepE involved in Anabaena heterocyst envelop polysaccharide biosynthesis.

    Science.gov (United States)

    Wang, Xue-Ping; Jiang, Yong-Liang; Dai, Ya-Nan; Cheng, Wang; Chen, Yuxing; Zhou, Cong-Zhao

    2016-05-01

    Formation of the heterocyst envelope polysaccharide (HEP) is a key process for cyanobacterial heterocyst differentiation. The maturation of HEP inAnabaenasp. strain PCC 7120 is controlled by a gene cluster termed HEP island in addition to an operonalr3698-alr3699, which encodes two putative proteins termed Alr3698/HepD and Alr3699/HepE. Here we report the crystal structures of HepE in the apo-form and three complex forms that bind to UDP-glucose (UDPG), UDP&glucose, and UDP, respectively. The overall structure of HepE displays a typical GT-B fold of glycosyltransferases, comprising two separate β/α/β Rossmann-fold domains that form an inter-domain substrate-binding crevice. Structural analyses combined with enzymatic assays indicate that HepE is a glucosyltransferase using UDPG as a sugar donor. Further site-directed mutageneses enable us to assign the key residues that stabilize the sugar donor and putative acceptor. Based on the comparative structural analyses, we propose a putative catalytic cycle of HepE, which undergoes "open-closed-open" conformational changes upon binding to the substrates and release of products. These findings provide structural and catalytic insights into the first enzyme involved in the HEP biosynthesis pathway. PMID:26692049

  3. The genome and transcriptome of Trichormus sp. NMC-1: insights into adaptation to extreme environments on the Qinghai-Tibet Plateau

    Science.gov (United States)

    Qiao, Qin; Huang, Yanyan; Qi, Ji; Qu, Mingzhi; Jiang, Chen; Lin, Pengcheng; Li, Renhui; Song, Lirong; Yonezawa, Takahiro; Hasegawa, Masami; Crabbe, M. James C.; Chen, Fan; Zhang, Ticao; Zhong, Yang

    2016-01-01

    The Qinghai-Tibet Plateau (QTP) has the highest biodiversity for an extreme environment worldwide, and provides an ideal natural laboratory to study adaptive evolution. In this study, we generated a draft genome sequence of cyanobacteria Trichormus sp. NMC-1 in the QTP and performed whole transcriptome sequencing under low temperature to investigate the genetic mechanism by which T. sp. NMC-1 adapted to the specific environment. Its genome sequence was 5.9 Mb with a G+C content of 39.2% and encompassed a total of 5362 CDS. A phylogenomic tree indicated that this strain belongs to the Trichormus and Anabaena cluster. Genome comparison between T. sp. NMC-1 and six relatives showed that functionally unknown genes occupied a much higher proportion (28.12%) of the T. sp. NMC-1 genome. In addition, functions of specific, significant positively selected, expanded orthogroups, and differentially expressed genes involved in signal transduction, cell wall/membrane biogenesis, secondary metabolite biosynthesis, and energy production and conversion were analyzed to elucidate specific adaptation traits. Further analyses showed that the CheY-like genes, extracellular polysaccharide and mycosporine-like amino acids might play major roles in adaptation to harsh environments. Our findings indicate that sophisticated genetic mechanisms are involved in cyanobacterial adaptation to the extreme environment of the QTP. PMID:27381465

  4. Cadmium toxicity to Microcystis aeruginosa PCC 7806 and its microcystin-lacking mutant.

    Directory of Open Access Journals (Sweden)

    Bin Huang

    Full Text Available The adverse effects of microcystin (MC produced by cyanobacteria have drawn considerable attention from the public. Yet it remains unclear whether MC confers any benefits to the cyanobacteria themselves. One suggested function of MC is complexation, which may influence the bioaccumulation and toxicity of trace metals. To test this hypothesis, we examined Cd toxicity to wild-type Microcystis aeruginosa PCC 7806 (WT and its MC-lacking mutant (MT under nutrient-enriched (+NP, phosphorus-limited (-P, and nitrogen-limited (-N conditions. The accumulation of Cd and the biochemical parameters associated with its detoxification [total phosphorus (TP, inorganic polyphosphate (Poly-P, and glutathione (GSH in the cells as well as intra- and extra-cellular carbohydrates] were quantified. Although the -P cyanobacteria accumulated less Cd than their +NP and -N counterparts, the different nutrient-conditioned cyanobacteria were similarly inhibited by similar free ion concentration of Cd in the medium ([Cd2+]F. Such good toxicity predictability of [Cd2+]F was ascribed to the synchronous decrease in the intracellular concentrations of Cd and TP. Nevertheless, Cd toxicity was still determined by the intracellular Cd to phosphorus ratio (Cd/P, in accordance with what has been reported in the literature. On the other hand, the concentrations of TP, Poly-P, and carbohydrates went up, but GSH concentration dropped down with the enhancement of [Cd2+]F, indicating their association with Cd detoxification. Although the inactivation of MC peptide synthetase gene had some nutrient and Cd concentration dependent effects on the parameters above, both cyanobacterial strains showed the same Cd accumulation ability and displayed similar Cd sensitivity. These results suggest that MC cannot affect metal toxicity either by regulating metal accumulation or by altering the detoxification ability of the cyanobacteria. Other possible functions of MC need to be further investigated.

  5. Factors Altering Pyruvate Excretion in a Glycogen Storage Mutant of the Cyanobacterium, Synechococcus PCC7942.

    Science.gov (United States)

    Benson, Phoebe J; Purcell-Meyerink, Diane; Hocart, Charles H; Truong, Thy T; James, Gabriel O; Rourke, Loraine; Djordjevic, Michael A; Blackburn, Susan I; Price, G D

    2016-01-01

    Interest in the production of carbon commodities from photosynthetically fixed CO2 has focused attention on cyanobacteria as a target for metabolic engineering and pathway investigation. We investigated the redirection of carbon flux in the model cyanobacterial species, Synechococcus elongatus PCC 7942, under nitrogen deprivation, for optimized production of the industrially desirable compound, pyruvate. Under nitrogen limited conditions, excess carbon is naturally stored as the multi-branched polysaccharide, glycogen, but a block in glycogen synthesis, via knockout mutation in the gene encoding ADP-glucose pyrophosphorylase (glgC), results in the accumulation of the organic acids, pyruvate and 2-oxoglutarate, as overflow excretions into the extracellular media. The ΔglgC strain, under 48 h of N-deprivation was shown to excrete pyruvate for the first time in this strain. Additionally, by increasing culture pH, to pH 10, it was possible to substantially elevate excretion of pyruvate, suggesting the involvement of an unknown substrate/proton symporter for export. The ΔglgC mutant was also engineered to express foreign transporters for glucose and sucrose, and then grown photomixotrophically with exogenous organic carbon supply, as added 5 mM glucose or sucrose during N- deprivation. Under these conditions we observed a fourfold increase in extracellular pyruvate excretion when glucose was added, and a smaller increase with added sucrose. Although the magnitude of pyruvate excretion did not correlate with the capacity of the ΔglgC strain for bicarbonate-dependent photosynthetic O2 evolution, or with light intensity, there was, however, a positive correlation observed between the density of the starter culture prior to N-deprivation and the final extracellular pyruvate concentration. The factors that contribute to enhancement of pyruvate excretion are discussed, as well as consideration of whether the source of carbon for pyruvate excretion might be derived from

  6. In Vitro Fatty Acid Synthesis and Complex Lipid Metabolism in the Cyanobacterium Anabaena variabilis: I. Some Characteristics of Fatty Acid Synthesis.

    Science.gov (United States)

    Lem, N W; Stumpf, P K

    1984-01-01

    In vitro fatty acid synthesis was examined in crude cell extracts, soluble fractions, and 80% (NH(4))(2)SO(4) fractions from Anabaena variabilis M3. Fatty acid synthesis was absolutely dependent upon acyl carrier protein and required NADPH and NADH. Moreover, fatty acid synthesis and elongation occurred in the cytoplasm of the cell. The major fatty acid products were palmitic acid (16:0) and stearic acid (18:0). Of considerable interest, both stearoyl-acyl carrier protein and stearoyl-coenzyme A desaturases were not detected in any of the fractions from A. variabilis. The similarities and differences in fatty acid synthesis between A. variabilis and higher plant tissues are discussed with respect to the endosymbiotic theory of chloroplast evolution. PMID:16663367

  7. Sugar supported H/sub 2/ production and C/sub 2/H/sub 2/ reduction by the cyanobiont Anabaena azollae

    Energy Technology Data Exchange (ETDEWEB)

    Rozen, A.; Tel-Or, E.

    1986-01-01

    Sugar supported activities of H/sub 2/ production and C/sub 2/H/sub 2/ reduction were characterized in axenic cell cultures of the cyanobiont Anabaena azollae isolated from the water fern Azolla filiculoides. Fructose was found to be the favoured substrate, enhancing activities in both the light and the dark even at relatively low concentrations of 0.5-1.0 mM. Higher concentrations of sucrose, (10-20mM) also supported H/sub 2/ production and C/sub 2/H/sub 2/ reduction, while glucose was less effective. Levels of H/sub 2/ production were always lower than those of C/sub 2/H/sub 2/ reduction. 13 references.

  8. Physiological Effects of Lanthanum on Cyanobacterium Anabaena azollae%稀土元素镧对满江红鱼腥藻的生理影响

    Institute of Scientific and Technical Information of China (English)

    宋凌云; 胡文月; 赵继贞; 邵宏翔; 张昀

    2000-01-01

    对稀土元素镧(La)对满江红鱼腥藻(Anabaena azollae)的生理影响和满江红鱼腥藻对镧的富集作用进行了研究.结果显示低浓度镧对满江红鱼腥藻生长表现出促进作用,高浓度则表现出抑制作用.镧对满江红鱼腥藻的叶绿素a的合成、光合放氧活性也有影响,同样表现为低浓度促进,高浓度抑制.满江红鱼腥藻对镧的富集作用可能与其光合作用电子传递和能量合成有关.

  9. Copper—Induced Changes in the Urea Uptake and Urease Activity in the Cyanobacteria Anabaena doliolum and Anacystis Nidulans:Interaction With Sulphur Containing Amino Acids

    Institute of Scientific and Technical Information of China (English)

    S.SINGH; B.B.SINGH; 等

    1995-01-01

    Copper-induced changes in the urea uptake and urease activity have been investigated in the cyanobacteria Anabaena doliolum and Anacystis nidulans.Copper,at and above 5μmol/L concentration,inhibited urea uptake and urease activity systems in both the cyanobacteria in a concentration dependent manner,However,the urea uptake and urease activity systems in A.nidulans apeared slightly more tolerant to copper than that of A.doliolum.The inhibitory effect of copeer on urea uptake and urease activity was mitigated by sulphur containing amino acids(cystine and cysteine),however,methionine could not do so,indicating the involvement of sulfhydryl(-SH) groups in the assimilation of urea in cyanobacteria.

  10. Inactivation of uptake hydrogenase leads to enhanced and sustained hydrogen production with high nitrogenase activity under high light exposure in the cyanobacterium Anabaena siamensis TISTR 8012

    Directory of Open Access Journals (Sweden)

    Khetkorn Wanthanee

    2012-10-01

    Full Text Available Abstract Background Biohydrogen from cyanobacteria has attracted public interest due to its potential as a renewable energy carrier produced from solar energy and water. Anabaena siamensis TISTR 8012, a novel strain isolated from rice paddy field in Thailand, has been identified as a promising cyanobacterial strain for use as a high-yield hydrogen producer attributed to the activities of two enzymes, nitrogenase and bidirectional hydrogenase. One main obstacle for high hydrogen production by A. siamensis is a light-driven hydrogen consumption catalyzed by the uptake hydrogenase. To overcome this and in order to enhance the potential for nitrogenase based hydrogen production, we engineered a hydrogen uptake deficient strain by interrupting hupS encoding the small subunit of the uptake hydrogenase. Results An engineered strain lacking a functional uptake hydrogenase (∆hupS produced about 4-folds more hydrogen than the wild type strain. Moreover, the ∆hupS strain showed long term, sustained hydrogen production under light exposure with 2–3 folds higher nitrogenase activity compared to the wild type. In addition, HupS inactivation had no major effects on cell growth and heterocyst differentiation. Gene expression analysis using RT-PCR indicates that electrons and ATP molecules required for hydrogen production in the ∆hupS strain may be obtained from the electron transport chain associated with the photosynthetic oxidation of water in the vegetative cells. The ∆hupS strain was found to compete well with the wild type up to 50 h in a mixed culture, thereafter the wild type started to grow on the relative expense of the ∆hupS strain. Conclusions Inactivation of hupS is an effective strategy for improving biohydrogen production, in rates and specifically in total yield, in nitrogen-fixing cultures of the cyanobacterium Anabaena siamensis TISTR 8012.

  11. Parasitismo por Giardia sp. e Cryptosporidium sp. em Coendou villosus Parasitism by Giardia sp. and Cryptosporidium sp. in Coendou villosus

    Directory of Open Access Journals (Sweden)

    João Fabio Soares

    2008-04-01

    Full Text Available O objetivo deste trabalho foi verificar o possível parasitismo por Giardia sp. e Cryptosporidium sp. em amostras de fezes de ouriço-cacheiro (Coendou villosus. As amostras foram analisadas pelo método de centrífugo-flutuação com sulfato de zinco e apresentaram elevada infecção por cistos de Giardia sp. e por oocistos de Cryptosporidium sp., embora os animais não apresentassem sinal clínico decorrente disso.This research was aimed at verifing the possible parasitism by Giardia sp. and Cryptosporidium sp. in porcupine (Coendou villosus faeces samples. Samples were analyzed by the centrifugal-flotation method with zinc sulphate and showed high infection by cysts of Giardia sp. and by oocysts of Cryptosporidium sp., although the animals did not show any associated clinical sign.

  12. Response of cyanobacteria to low atmospheric pressure

    Science.gov (United States)

    Qin, Lifeng; Yu, Qingni; Ai, Weidang; Tang, Yongkang; Ren, Jin; Guo, Shuangsheng

    2014-10-01

    Maintaining a low pressure environment in a controlled ecological life support system would reduce the technological complexity and resupply cost in the course of the construction of a future manned lunar base. To estimate the effect of a hypobaric environment in a lunar base on biological components, such as higher plants, microbes, and algae, cyanobacteria was used as the model by determining their response of growth, morphology, and physiology when exposed to half of standard atmospheric pressure for 16 days (brought back to standard atmospheric pressure 30 minutes every two days for sampling). The results indicated that the decrease of atmospheric pressure from 100 kPa to 50 kPa reduced the growth rates of Microcystis aeruginosa, Merismopedia sp., Anabaena sp. PCC 7120, and Anabaena flos-aquae. The ratio of carotenoid to chlorophyll a content in the four tested strains increased under low pressure conditions compared to ambient conditions, resulting from the decrease of chlorophyll a and the increase of carotenoid in the cells. Moreover, low pressure induced the reduction of the phycocyanin content in Microcystis aeruginosa, Anabaena sp. PCC 7120, and Anabaena flos-aquae. The result from the ultrastructure observed using SEM indicated that low pressure promoted the production of more extracellular polymeric substances (EPSs) compared to ambient conditions. The results implied that the low pressure environment of 50 kPa in a future lunar base would induce different effects on biological components in a CELSS, which must be considered during the course of designing a future lunar base. The results will be a reference for exploring the response of other biological components, such as plants, microbes, and animals, living in the life support system of a lunar base.

  13. The Synechococcus strain PCC 7942 glnN product (glutamine synthetase III) helps recovery from prolonged nitrogen chlorosis.

    Science.gov (United States)

    Sauer, J; Dirmeier, U; Forchhammer, K

    2000-10-01

    We report the cloning and sequencing of the glnN gene encoding a class III glutamine synthetase from the cyanobacterium Synechococcus strain PCC 7942. Mapping of the transcriptional start site revealed a DNA sequence in the promoter region that resembles an imperfect NtcA binding motif. Expression of glnN is impaired in NtcA- and P(II)-deficient mutants. The only parameter which was negatively affected in the glnN mutant compared to the wild type was the recovery rate of prolonged nitrogen-starved cells with low concentrations of combined nitrogen. PMID:10986271

  14. The Synechococcus Strain PCC 7942 glnN Product (Glutamine Synthetase III) Helps Recovery from Prolonged Nitrogen Chlorosis

    OpenAIRE

    Sauer, Jörg; Dirmeier, Ulrike; Forchhammer, Karl

    2000-01-01

    We report the cloning and sequencing of the glnN gene encoding a class III glutamine synthetase from the cyanobacterium Synechococcus strain PCC 7942. Mapping of the transcriptional start site revealed a DNA sequence in the promoter region that resembles an imperfect NtcA binding motif. Expression of glnN is impaired in NtcA- and PII-deficient mutants. The only parameter which was negatively affected in the glnN mutant compared to the wild type was the recovery rate of prolonged nitrogen-star...

  15. LTE网络引入PCC的业务保障策略分析%Analysis of the Policy of PCC Deployment for Service Control in LTE

    Institute of Scientific and Technical Information of China (English)

    袁鹏辉; 龙彪; 陈洁

    2012-01-01

    简要介绍了PCC系统的基本架构和功能,分析了LTE网络中PCC的业务保障能力和机制,并结合运营商自营视频类业务重点分析了PCC的业务保障流程,最后给出了国内运营商在LTE网络部署PCC保障业务的策略建议.%The PCC architecture and function were introduced firstly, and then the capability and mechanism of service assurance based on PCC architecture were analyzed and the service assurance procedures were shown for a classical video service owned by operators.Finally, suggestions on the deployment of PCC in LTE was presented.

  16. Nezha, a novel active miniature inverted-repeat transposable element in cyanobacteria

    International Nuclear Information System (INIS)

    Miniature inverted-repeat transposable elements (MITEs) were first identified in plants and exerted extensive proliferations throughout eukaryotic and archaeal genomes. But very few MITEs have been characterized in bacteria. We identified a novel MITE, called Nezha, in cyanobacteria Anabaena variabilis ATCC 29413 and Nostoc sp. PCC 7120. Nezha, like most previously known MITEs in other organisms, is small in size, non-coding, carrying TIR and DR signals, and of potential to form a stable RNA secondary structure, and it tends to insert into A+T-rich regions. Recent transpositions of Nezha were observed in A. variabilis ATCC 29413 and Nostoc sp. PCC 7120, respectively. Nezha might have proliferated recently with aid from the transposase encoded by ISNpu3-like elements. A possible horizontal transfer event of Nezha from cyanobacteria to Polaromonas JS666 is also observed

  17. Photojournalism: the assaults of PCC in the pages of Folha and the Estadão Fotojornalismo: os ataques do PCC nas páginas da Folha e do Estadão

    Directory of Open Access Journals (Sweden)

    Paulo Cesar Boni

    2007-01-01

    Full Text Available This article addresses the photojournalistic coverage carried out by Folha de S.Paulo and O Estado de S. Paulo during the assaults of the First Command in the Capital (PCC in May 2006. The methods used here were those of technical deconstruction - to analyze the elements of photographic language in the construction of the message – and comparative analysis - to check the creation of meaning in those messages. Through these methodological procedures, it is inferred that Folha adopted a more sensationalistic feature with spectacularization of those images than Estadão, which adopted a more neutral and realistic posture in the view of the facts. Esse artigo aborda a cobertura fotojornalística realizada pela Folha de S.Paulo e pelo O Estado de S. Paulo durante os ataques do Primeiro Comando da Capital (PCC em maio de 2006. Os métodos utilizados foram o da desconstrução técnica – para análise dos elementos da linguagem fotográfica na construção da mensagem – e análise comparativa – para aferir a geração de sentido nas mensagens. Por esses procedimentos metodológicos, conclui que Folha assumiu um caráter mais sensacionalista, com espetacularização das imagens que o Estadão, que adotou uma postura mais neutra e realista diante dos fatos.

  18. Comparison of denitrification between Paracoccus sp. and Diaphorobacter sp.

    Science.gov (United States)

    Chakravarthy, Srinandan S; Pande, Samay; Kapoor, Ashish; Nerurkar, Anuradha S

    2011-09-01

    Denitrification was compared between Paracoccus sp. and Diaphorobacter sp. in this study, both of which were isolated from activated sludge of a denitrifying reactor. Denitrification of both isolates showed contrasting patterns, where Diaphorobacter sp. showed accumulation of nitrite in the medium while Paracoccus sp. showed no accumulation. The nitrate reduction rate was 1.5 times more than the nitrite reduction in Diaphorobacter sp., as analyzed by the resting state denitrification kinetics. Increasing the nitrate concentration in the medium increased the nitrite accumulation in Diaphorobacter sp., but not in Paracoccus sp., indicating a branched electron transfer during denitrification. Diaphorobacter sp. was unable to denitrify efficiently at high nitrate concentrations from 1 M, but Paracoccus sp. could denitrify even up to 2 M nitrate. Paracoccus sp. was found to be an efficient denitrifier with insignificant amounts of nitrite accumulation, and it could also denitrify high amounts of nitrate up to 2 M. Efficient denitrification without accumulation of intermediates like nitrite is desirable in the removal of high nitrates from wastewaters. Paracoccus sp. is shown to suffice this demand and could be a potential organism to remove high nitrates effectively. PMID:21509603

  19. Flavodoxin from Anabaena 7120: uniform nitrogen-15 enrichment and hydrogen-1, nitrogen-15, and phosphorus-31 NMR investigation of the flavin mononucleotide binding site in the reduced and oxidized states

    International Nuclear Information System (INIS)

    Interactions between flavin mononucleotide (FMN) and apoprotein have been investigated in the reduced and oxidized states of the flavodoxin isolated from Anabaena 7120 (M/sub r/ ∼ 21,000). 1H, 15N, and 31P NMR have been used to characterize the FMN-protein interactions in both redox states. These are compared with those seen in other flavodoxins. Uniformly enriched [15N] flavodoxin was isolated from Anabaena 7120 grown on K15NO3 as the sole nitrogen source. 15N insensitive nucleus enhanced by polarization transfer (INEPT) and nuclear Overhauser effect (NOE) studies of this sample provided information regarding protein structure and dynamics. A 1H-detected 15N experiment allowed the correlation of nitrogen resonances to those of their attached protons. Over 90% of the expected N-H cross peaks could be resolved in this experiment

  20. Identification of a common cyanobacterial symbiont associated with Azolla spp. through molecular and morphological characterization of free-living and symbiotic cyanobacteria.

    OpenAIRE

    Gebhardt, J S; Nierzwicki-Bauer, S A

    1991-01-01

    Symbiotically associated cyanobacteria from Azolla mexicana and Azolla pinnata were isolated and cultured in a free-living state. Morphological analyses revealed differences between the free-living isolates and their symbiotic counterparts, as did restriction fragment length polymorphism (RFLP) analyses with both single-copy glnA and rbcS gene probes and a multicopy psbA gene probe. RFLP analyses with Anabaena sp. strain PCC 7120 nifD excision element probes, including an xisA gene probe, det...

  1. 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

  2. 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

  3. Transcriptional regulator PrqR plays a negative role in glucose metabolism and oxidative stress acclimation in Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Khan, Rezaul Islam; Wang, Yushu; Afrin, Shajia; Wang, Bing; Liu, Yumin; Zhang, Xiaoqing; Chen, Lei; Zhang, Weiwen; He, Lin; Ma, Gang

    2016-01-01

    Plant and cyanobacteria can perceive signals from soluble sugar and reactive oxygen species (ROS) and then coordinate gene expression under stress acclimation, but the underlying mechanism remains unclear. In this study, we found that the transcriptional factor PrqR (Slr0895) in Synechocystis can perceive signals from ROS generated after shifting from prolonged darkness with glucose into high-light. The deletion mutant (DprqR) showed increased growth rate and decreased ROS content, whereas the complementary strain (CprqR) restored the growth characteristics, phenotypes and ROS status of WT, thereby establishing PrqR as a negative regulator of ROS.LC/GC-MS-based metabolic profiling also showed active ROS mitigation in DprqR mutant. Further study by qRT-PCR, ChIP-PCR and deletion of both prqR and prqA (DprqR-DprqA mutant) revealed that PrqR exerts this negative regulation of ROS removal by controlling the expression of sodB and prqA (slr0896). Furthermore, PrqR also found to control glucose metabolism by regulating a positive regulator of glucose metabolism, sigE, and its regulons. Results suggest that PrqR was involved in perceiving signals from ROS under physiological condition, as well as in regulating stress removal and glucose metabolism. PMID:27582046

  4. 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

  5. Complementation of a phycocyanin-bilin lyase from Synechocystis sp. PCC 6803 with a nucleomorph-encoded open reading frame from the cryptophyte Guillardia theta

    OpenAIRE

    Nyalwidhe Julius; Gruenheit Nicole; Prechtl Julia; Kawach Oliver; Bolte Kathrin; Maier Uwe-G

    2008-01-01

    Abstract Background Cryptophytes are highly compartmentalized organisms, expressing a secondary minimized eukaryotic genome in the nucleomorph and its surrounding remnant cytoplasm, in addition to the cell nucleus, the mitochondrion and the plastid. Because the members of the nucleomorph-encoded proteome may contribute to essential cellular pathways, elucidating nucleomorph-encoded functions is of utmost interest. Unfortunately, cryptophytes are inaccessible for genetic transformations thus f...

  6. Effects of Bleaching by Nitrogen Deficiency on the Quantum Yield of Photosystem II in Synechocystis sp. PCC 6803 Revealed by Chl Fluorescence Measurements.

    Science.gov (United States)

    Ogawa, Takako; Sonoike, Kintake

    2016-03-01

    Estimation of photosynthesis by Chl fluorescence measurement of cyanobacteria is always problematic due to the interference from respiratory electron transfer and from phycocyanin fluorescence. The interference from respiratory electron transfer could be avoided by the use of DCMU or background illumination by blue light, which oxidizes the plastoquinone pool that tends to be reduced by respiration. On the other hand, the precise estimation of photosynthesis in cells with a different phycobilisome content by Chl fluorescence measurement is difficult. By subtracting the basal fluorescence due to the phycobilisome and PSI, it becomes possible to estimate the precise maximum quantum yield of PSII in cyanobacteria. Estimated basal fluorescence accounted for 60% of the minimum fluorescence, resulting in a large difference between the 'apparent' yield and 'true' yield under high phycocyanin conditions. The calculated value of the 'true' maximum quantum yield of PSII was around 0.8, which was similar to the value observed in land plants. The results suggest that the cause of the apparent low yield reported in cyanobacteria is mainly ascribed to the interference from phycocyanin fluorescence. We also found that the 'true' maximum quantum yield of PSII decreased under nitrogen-deficient conditions, suggesting the impairment of the PSII reaction center, while the 'apparent' maximum quantum yield showed a marginal change under the same conditions. Due to the high contribution of phycocyanin fluorescence in cyanobacteria, it is essential to eliminate the influence of the change in phycocyanin content on Chl fluorescence measurement and to evaluate the 'true' photosynthetic condition. PMID:26858287

  7. 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 Institutional support: RVO:67179843 Keywords : biofuels * cyanobacteria * photobioreactor * MIMS * biotechnology Subject RIV: EH - Ecology, Behaviour Impact factor: 4.494, year: 2014

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

    Czech Academy of Sciences Publication Activity Database

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

    2016-01-01

    Roč. 202, - (2016), s. 142-151. ISSN 0960-8524 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 Keywords : biofuels * cyanobacteria * photobioreactor * MIMS * biotechnology Subject RIV: EH - Ecology, Behaviour Impact factor: 4.494, year: 2014

  9. 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 constituent of a stress-related operon, and homology to eukaryotic enzymes points to a yet not considered possibility of their being involved in scavenging of apocarotenals. © 2013 FEBS.

  10. The effects of low nitrate levels on the freshwater cyanobacterium Synechocystis sp. strain PCC 6803: construction of a bioreporter assay and molecular characterization by transcriptome and proteome analysis

    OpenAIRE

    Mbeunkui, Flaubert

    2003-01-01

    Since a few decades the so-called blue algal blooms came to public awareness and their occurrence was more frequently reported. These blooms stem from the mass proliferation of some cyanobacterial species and they occur both in the sea as well as in fresh water. The exact reasons for this phenomenon have not been finally clarified, but nutrient availability, limitation and excess, has a proven influence. Some bioavailability patterns of P, N, S and Fe strongly promote cyanobacterial prolifera...

  11. Control of Branchionus sp. and Amoeba sp. in cultures of Arthrospira sp. Control de Branchionus sp. y Amoeba sp. en cultivos de Arthrospira sp.

    Directory of Open Access Journals (Sweden)

    Carlos Méndez

    2012-09-01

    Full Text Available Cultivation of cyanobacterium Arthrospira sp. has been developed in many countries for the production of proteins, pigments and other compounds. Outdoor mass cultures are often affected by biological contamination, drastically reducing productivity as far as bringing death. This study evaluates the control of Branchionus sp. and Amoeba sp. with two chemical compounds: urea (U and ammonium bicarbonate (AB, in laboratory conditions and outdoor mass culture of Arthrospira sp. The lethal concentration 100 (LC100 at 24 h for Branchionus sp. and Amoeba sp. determined was of 60-80 mg L-1 (U and 100-150 mg L-1 (AB. The average effective inhibition concentration for 50% of the population (IC50 in Arthrospira sp., after 72 h, was 80 mg L-1 (U and 150 mg L-1 (AB. The application of doses of 60 mg L-1 (U or 100 mg L-1 (AB in the outdoor mass culture of this contaminated microalga, completely inhibited grazing and did not affect the growth of Arthrospira sp. but rather promoted rapid recovery of algal density at levels prior to infestation. These compounds provided an economical and effective control of predators in cultures of Arthrospira sp.El cultivo de la cianobacteria Arthrospira sp. ha sido desarrollado en muchos países para la obtención de proteínas, pigmentos y otros compuestos. Cultivo que a nivel industrial se ve afectado frecuentemente por contaminación biológica, reduciendo drásticamente la productividad hasta causar la muerte. Este estudio evalúa el control de Branchionus sp. y de Amoeba sp. con dos compuestos químicos, la urea (U y bicarbonato de amonio (AB en cultivos de Arthrospira sp. La concentración letal 100 (LC100 determinada a las 24 h para Branchionus sp. y Amoeba sp. fue de 60-80 mg L-1 (U y 100-150 mg L-1 (AB. La concentración media de inhibición efectiva, después de 72 h, para el 50% de la población (IC50 en Arthrospira fue de 80 mg L-1 (U y 150 mg L-1 (AB. La aplicación de dosis de 60 mg L-1 (U ó 100 mg L-1 (AB en

  12. A newly designed 45 to 60 mer oligonucleotide Agilent platform microarray for global gene expression studies of Synechocystis PCC6803: example salt stress experiment

    NARCIS (Netherlands)

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

    2005-01-01

    A newly designed 45 to 60 mer oligonucleotide Agilent platform microarray for global gene expression studies of Synechocystis PCC6803: example salt stress experiment Eneas Aguirre-von-Wobeser 1, Jef Huisman1, Bas Ibelings2 and Hans C.P. Matthijs1 1 Universiteit van Amsterdam, Amsterdam, The Netherla

  13. 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

  14. A New Real-time Method Monitoring Behaviors of Living Cells In Vitro-PCC%体外实时监测细胞行为的新方法-压电细胞芯片(PCC)

    Institute of Scientific and Technical Information of China (English)

    韦晓兰; 莫志宏

    2006-01-01

    压电细胞芯片(Piezoelectric cell-based chip,PCC)是以压电生物芯片检测技术为基础,结合体外细胞培养技术,将生活细胞作为研究对象或敏感元件,构建出的一种能实时动态监测细胞行为的多参数检测体系.该技术通过检测细胞生长过程中的Δf、ΔZ、ΔD等多种参数,反映细胞生长代谢的基本功能信息.文中介绍了PCC的原理、操作方法、结果与讨论等,并对其发展方向和应用进行了展望.

  15. Expanding the Role of FurA as Essential Global Regulator in Cyanobacteria.

    Directory of Open Access Journals (Sweden)

    Andrés González

    Full Text Available In the nitrogen-fixing heterocyst-forming cyanobacterium Anabaena sp. PCC 7120, the ferric uptake regulator FurA plays a global regulatory role. Failures to eliminate wild-type copies of furA gene from the polyploid genome suggest essential functions. In the present study, we developed a selectively regulated furA expression system by the replacement of furA promoter in the Anabaena sp. chromosomes with the Co2+/Zn2+ inducible coaT promoter from Synechocystis sp. PCC 6803. By removing Co2+ and Zn2+ from the medium and shutting off furA expression, we showed that FurA was absolutely required for cyanobacterial growth. RNA-seq based comparative transcriptome analyses of the furA-turning off strain and its parental wild-type in conjunction with subsequent electrophoretic mobility shift assays and semi-quantitative RT-PCR were carried out in order to identify direct transcriptional targets and unravel new biological roles of FurA. The results of such approaches led us to identify 15 novel direct iron-dependent transcriptional targets belonging to different functional categories including detoxification and defences against oxidative stress, phycobilisome degradation, chlorophyll catabolism and programmed cell death, light sensing and response, heterocyst differentiation, exopolysaccharide biosynthesis, among others. Our analyses evidence novel interactions in the complex regulatory network orchestrated by FurA in cyanobacteria.

  16. Expanding the Role of FurA as Essential Global Regulator in Cyanobacteria

    Science.gov (United States)

    González, Andrés; Bes, M. Teresa; Peleato, M. Luisa; Fillat, María F.

    2016-01-01

    In the nitrogen-fixing heterocyst-forming cyanobacterium Anabaena sp. PCC 7120, the ferric uptake regulator FurA plays a global regulatory role. Failures to eliminate wild-type copies of furA gene from the polyploid genome suggest essential functions. In the present study, we developed a selectively regulated furA expression system by the replacement of furA promoter in the Anabaena sp. chromosomes with the Co2+/Zn2+ inducible coaT promoter from Synechocystis sp. PCC 6803. By removing Co2+ and Zn2+ from the medium and shutting off furA expression, we showed that FurA was absolutely required for cyanobacterial growth. RNA-seq based comparative transcriptome analyses of the furA-turning off strain and its parental wild-type in conjunction with subsequent electrophoretic mobility shift assays and semi-quantitative RT-PCR were carried out in order to identify direct transcriptional targets and unravel new biological roles of FurA. The results of such approaches led us to identify 15 novel direct iron-dependent transcriptional targets belonging to different functional categories including detoxification and defences against oxidative stress, phycobilisome degradation, chlorophyll catabolism and programmed cell death, light sensing and response, heterocyst differentiation, exopolysaccharide biosynthesis, among others. Our analyses evidence novel interactions in the complex regulatory network orchestrated by FurA in cyanobacteria. PMID:26967347

  17. PRR11 regulates late-S to G2/M phase progression and induces premature chromatin condensation (PCC)

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chundong; Zhang, Ying; Li, Yi; Zhu, Huifang; Wang, Yitao; Cai, Wei [Department of Biochemistry and Molecular Biology, Chongqing Medical University, Chongqing 400016 (China); Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016 (China); Zhu, Jiang [Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016 (China); Ozaki, Toshinori [Laboratory of DNA Damage Signaling, Chiba Cancer Center Research Institute, 666-2 Nitona, Chuohku, Chiba 260-8717 (Japan); Bu, Youquan, E-mail: buyqcn@aliyun.com [Department of Biochemistry and Molecular Biology, Chongqing Medical University, Chongqing 400016 (China); Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016 (China)

    2015-03-13

    Recently, we have demonstrated that proline-rich protein 11 (PRR11) is a novel tumor-related gene product likely implicated in the regulation of cell cycle progression as well as lung cancer development. However, its precise role in cell cycle progression remains unclear. In the present study, we have further investigated the expression pattern and functional implication of PRR11 during cell cycle in detail in human lung carcinoma-derived H1299 cells. According to our immunofluorescence study, PRR11 was expressed largely in cytoplasm, the amount of PRR11 started to increase in the late S phase, and was retained until just before mitotic telophase. Consistent with those observations, siRNA-mediated knockdown of PRR11 caused a significant cell cycle arrest in the late S phase. Intriguingly, the treatment with dNTPs further augmented PRR11 silencing-mediated S phase arrest. Moreover, knockdown of PRR11 also resulted in a remarkable retardation of G2/M progression, and PRR11-knockdown cells subsequently underwent G2 phase cell cycle arrest accompanied by obvious mitotic defects such as multipolar spindles and multiple nuclei. In addition, forced expression of PRR11 promoted the premature Chromatin condensation (PCC), and then proliferation of PRR11-expressing cells was massively attenuated and induced apoptosis. Taken together, our current observations strongly suggest that PRR11, which is strictly regulated during cell cycle progression, plays a pivotal role in the regulation of accurate cell cycle progression through the late S phase to mitosis. - Highlights: • PRR11 started to increase in the late S phase and was retained until just before mitotic telophase. • PRR11-knockdown caused a significant cell cycle arrest in the late S phase and G2 phase. • The treatment with dNTPs further augmented PRR11 silencing-mediated S phase arrest. • PRR11-knockdown led to multipolar spindles and multiple nuclei. • Forced expression of PRR11 promoted the PCC and inhibited

  18. PRR11 regulates late-S to G2/M phase progression and induces premature chromatin condensation (PCC)

    International Nuclear Information System (INIS)

    Recently, we have demonstrated that proline-rich protein 11 (PRR11) is a novel tumor-related gene product likely implicated in the regulation of cell cycle progression as well as lung cancer development. However, its precise role in cell cycle progression remains unclear. In the present study, we have further investigated the expression pattern and functional implication of PRR11 during cell cycle in detail in human lung carcinoma-derived H1299 cells. According to our immunofluorescence study, PRR11 was expressed largely in cytoplasm, the amount of PRR11 started to increase in the late S phase, and was retained until just before mitotic telophase. Consistent with those observations, siRNA-mediated knockdown of PRR11 caused a significant cell cycle arrest in the late S phase. Intriguingly, the treatment with dNTPs further augmented PRR11 silencing-mediated S phase arrest. Moreover, knockdown of PRR11 also resulted in a remarkable retardation of G2/M progression, and PRR11-knockdown cells subsequently underwent G2 phase cell cycle arrest accompanied by obvious mitotic defects such as multipolar spindles and multiple nuclei. In addition, forced expression of PRR11 promoted the premature Chromatin condensation (PCC), and then proliferation of PRR11-expressing cells was massively attenuated and induced apoptosis. Taken together, our current observations strongly suggest that PRR11, which is strictly regulated during cell cycle progression, plays a pivotal role in the regulation of accurate cell cycle progression through the late S phase to mitosis. - Highlights: • PRR11 started to increase in the late S phase and was retained until just before mitotic telophase. • PRR11-knockdown caused a significant cell cycle arrest in the late S phase and G2 phase. • The treatment with dNTPs further augmented PRR11 silencing-mediated S phase arrest. • PRR11-knockdown led to multipolar spindles and multiple nuclei. • Forced expression of PRR11 promoted the PCC and inhibited

  19. Preparation of Calibration Standards of N1-H Paralytic Shellfish Toxin Analogues by Large-Scale Culture of Cyanobacterium Anabaena circinalis (TA04

    Directory of Open Access Journals (Sweden)

    Toshiyuki Suzuki

    2011-03-01

    Full Text Available Mouse bioassay is the official testing method to quantify paralytic shellfish toxins (PSTs in bivalves. A number of alternative analytical methods have been reported. Some methods have been evaluated by a single laboratory validation. Among the different types of methods, chemical analyses are capable of identifying and quantifying the toxins, however a shortage of the necessary calibration standards hampers implementation of the chemical analyses in routine monitoring of PSTs in bivalves. In our present study, we studied preparation of major PST analogues as calibrants by large-scale cultivation of toxic freshwater cyanobacteria Anabaena circinalis TA04. The cells were steadily grown in 10 L bottle for 28 days. The primary N1-H toxins, C1/C2, were produced at a concentration of 1.3 ± 0.1 µmol/L. The intracellular and extracellular toxins occupied 80% and 20%, respectively. Over 220 µmol of the toxins was obtained from approximately 200 L of the culture over six months, demonstrating that it is sufficient to prepare saxitoxin analogues. The toxins were chemically converted to six N1-H analogues. Preparation of the analogues was carried out at relatively high yields (50–90%. The results indicate that our preparation method is useful to produce N1-H toxins. In our present study, detailed conditions for preparation of one of the rare N1-H analogues, gonyautoxin-5, were investigated.

  20. Azolla-Anabaena as a Biofertilizer for Rice Paddy Fields in the Po Valley, a Temperate Rice Area in Northern Italy

    Directory of Open Access Journals (Sweden)

    Stefano Bocchi

    2010-01-01

    Full Text Available Azolla is a floating pteridophyte, which contains as endosymbiont the nitrogen-fixing cyanobacterium Anabaena azollae (Nostocaceae family. Widely cultivated in the Asian regions, Azolla is either incorporated into the soil before rice transplanting or grown as a dual crop along with rice. To examine the feasibility of its use in flooded rice fields sited in the Temperate European Areas, we carried out a series of experiments in PVC tanks during 2000–2002 in Po Valley (northern Italy conditions, to study the growth-development dynamics and the resistance/tolerance to low temperatures and to commonly used herbicides of several different Azolla strains. Three out of five strains tested survived the winter, with an increase in biomass from March to May producing approximately 30–40 kg ha−1 of nitrogen. One of these strains, named “Milan”, emerged as the most resistant to herbicide and the most productive. Of the herbicides tested, Propanil permitted the survival of growing Azolla.

  1. Removal of Anabaena flos-aquae in water treatment process using Moringa oleifera and assessment of fatty acid profile of generated sludge.

    Science.gov (United States)

    Moreti, Livia O R; Coldebella, Priscila Ferri; Camacho, Franciele P; Carvalho Bongiovani, Milene; Pereira de Souza, Aloisio Henrique; Kirie Gohara, Aline; Matsushita, Makoto; Fernandes Silva, Marcela; Nishi, Letícia; Bergamasco, Rosângela

    2016-01-01

    This study aimed to evaluate the efficiency of the coagulation/flocculation/dissolved air flotation (C/F/DAF) process using the coagulant Moringa oleifera (MO) seed powder, and to analyse the profile of fatty acids present in the generated sludge after treatment. For the tests, deionized water artificially contaminated with cell cultures of Anabaena flos-aquae was used, with a cell density in the order of 10(4) cells mL(-1). C/F/DAF tests were conducted using 'Flotest' equipment. For fatty acid profile analyses, a gas chromatograph equipped with a flame ionization detector was used. It was seen that the optimal dosage (100 mg L(-1)) of MO used in the C/F/DAF process was efficient at removing nearly all A. flos-aquae cells (96.4%). The sludge obtained after treatment contained oleic acid (61.7%) and palmitic acid (10.8%). Thus, a water treatment process using C/F/DAF linked to integral MO powder seed was found to be efficient in removing cells of cyanobacteria, and produced a sludge rich in oleic acid that is a precursor favourable for obtaining quality biodiesel, thus becoming an alternative application for the recycling of such biomass. PMID:26586082

  2. Proteogenomics of a saxitoxin-producing and non-toxic strain of Anabaena circinalis (cyanobacteria) in response to extracellular NaCl and phosphate depletion.

    Science.gov (United States)

    D'Agostino, Paul M; Song, Xiaomin; Neilan, Brett A; Moffitt, Michelle C

    2016-02-01

    In Australia, saxitoxin production is strain dependent within the bloom-forming freshwater cyanobacterium Anabaena circinalis. Freshwater cyanobacteria are exposed to rapid fluctuations in environmental nutrient concentrations, and their adaption is vital for competition, succession and dominance. Two elements of environmental significance, phosphorus and sodium chloride, are proposed to play a role in bloom development and saxitoxin biosynthesis respectively. The aim of our study was to comparatively analyse the model saxitoxin-producing A. circinalis AWQC131C and non-toxic A. circinalis AWQC310F at the genomic level and proteomic level, in response to phosphate depletion and increased extracellular NaCl. When challenged, photosynthesis, carbon/nitrogen metabolisms, transcription/translation, oxidative stress and nutrient transport functional categories demonstrated the largest changes in protein abundance. In response to increased NaCl, SxtC, a protein conserved in all known saxitoxin biosynthetic pathways, was downregulated. Additionally, toxin quantification revealed a decrease in total saxitoxin and decarbomoyl-gonyautoxin2/3 content in response to the NaCl treatment. In response to phosphate depletion, the toxic and non-toxic strain displayed similar proteomic profiles, although the toxic strain did not alter the abundance of as many proteins as the non-toxic strain. These findings have important implications for the future, since response and adaption mechanisms are directly related to in situ dominance of cyanobacteria. PMID:26568470

  3. SP-100 Test Site

    International Nuclear Information System (INIS)

    Preparatory activities are well under way at Hanford to convert the 309 Containment Building and its associated service wing to a 2.5 MWt nuclear test facility for the SP-100 Ground Engineering System (GES) test. Preliminary design is complete, encompassing facility modifications, a secondary heat transport system, a large vacuum system to enclose the high temperature reactor, a test assembly cell and handling system, control and data processing systems, and safety and auxiliary systems. The design makes extensive use of existing equipment to minimize technical risk and cost. Refurbishment of this equipment is 75% complete. The facility has been cleared of obstructing equipment from its earlier reactor test. Current activities are focusing on definitive design and preparation of the Preliminary Safety Analysis Report (PSAR) aimed at procurement and construction approvals and schedules to achieve reactor criticality by January 1992. 6 refs

  4. 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

  5. Effects of cell density, carbon dioxide and molybdenum concentration on biohydrogen production by Anabaena variabilis ATCC 29413

    International Nuclear Information System (INIS)

    Highlights: • Low concentration of CO2 in headspace (4–8% vol/vol) enhanced hydrogen productivity. • Glucose addition did not cause a high oxygen build-up in the headspace. • Hydrogen productivity was highly optimized at elevated Mo6+ concentration of 1.6 mM. - Abstract: This paper aims to determine the effects of cell density, carbon dioxide, and molybdenum concentration towards hydrogen production rate. Batch cultures of Anabaenavariabilis sp. were incubated in anaerobic environment under continuous indoor illumination of 70 μE m−2 s−1 at 35 °C. The optimal volumetric hydrogen production rate obtained was 44 μmol H2 mg chl a−1 h−1 occurred at cells density of 110 mg L−1, 5% carbon dioxide headspace concentration, and molybdenum concentration of 1.6 mM. The effect of organic carbon source (glucose) was also evaluated in the present study and it was found that the additional carbon produced the highest hydrogen production rate in all conditions. An increased concentration of molybdenum significantly enhanced the hydrogen productivity rate almost to that of glucose-supplemented culture at 49 μmol H2 mg chl a−1 h−1. However, further increase in molybdenum concentration beyond 1.6 mM showed no further improvement in the amount of hydrogen produced

  6. Biogeographically interesting planktonic Nostocales (Cyanobacteria) in the Czech Republic and their polyphasic evaluation resulting in taxonomic revisions of Anabaena bergii Ostenfeld 1908 (Chrysosporum gen. nov.) and A. tenericaulis Nygaard 1949 (Dolichospermum tenericaule comb. nova)

    Czech Academy of Sciences Publication Activity Database

    Zapomělová, Eliška; Skácelová, O.; Pumann, P.; Kopp, R.; Janeček, E.

    2012-01-01

    Roč. 698, č. 1 (2012), s. 353-365. ISSN 0018-8158. [Workshop of the International Association of Phytoplankton Taxonomy and Ecology. Trento, 21.08.2011-28.08.2011] R&D Projects: GA ČR(CZ) GAP504/10/1501; GA ČR(CZ) GA206/09/0309 Institutional research plan: CEZ:AV0Z60170517 Keywords : Anabaena * Dolichospermum * Sphaerospermopsis * taxonomy * identification * morphological variability * 16S rRNA gene * biogeography * alien species * cyanobacteria Subject RIV: EE - Microbiology, Virology Impact factor: 1.985, year: 2012

  7. Effects of an Anatoxin-a(s)-Producing Strain of Anabaena spiroides (Cyanobacteria) on the Survivorship and Somatic Growth of Two Daphnia similis Clones

    OpenAIRE

    Fábio Q. de Abreu; Aloysio da S. Ferrão-Filho

    2013-01-01

    The toxicity of an anatoxin-a(s) producer strain of Anabaena spiroides (ITEP-024) was estimated through sub-chronic bioassays with two clones of Daphnia similis (Labtox and Itajubá), both with intact cells and aqueous extracts of lyophilized material. Animals were grown as clonal cultures in the lab with mineral water plus 20% lake water. The concentrations used in the bioassays were 0.125, 0.25, 0.375, 0.50 and 1.00 mg·L-1 for intact cell cultures and 10, 25, 50 and 100 mg·L-1 for aqueous e...

  8. Bradysia sp. em morangueiro Bradysia sp. in strawberry

    Directory of Open Access Journals (Sweden)

    Bernadete Radin

    2009-04-01

    Full Text Available No trabalho, relatam-se os primeiros registros de Bradysia sp. (Insecta: Diptera: Sciaridae em morangueiro (Fragaria x ananassa Duch., cultivado no Município de Eldorado do Sul, RS. O cultivo foi realizado em sacolas com três metros de comprimento, preenchidas com substrato composto de casca de arroz e turfa, dispostas horizontalmente sobre bancadas de madeira, em ambiente protegido. A presença de Bradysia sp. foi observada na segunda quinzena de agosto de 2005. Neste trabalho, estão descritos os sintomas apresentados no morangueiro pela praga, prováveis conseqüências sobre o aparecimento de doenças e uma breve descrição morfológica da Bradysia sp., adulto e fase larval.This paper describes the first record of Bradysia sp. (Insecta; Diptera; Sciaridae in strawberry (Fragaria x ananassa, cultivated in the city of Eldorado do Sul, RS, Brazil. Strawberry was planted in plastic bags filled with a mixture of burnt rice hulls and peat and cultivated in a greenhouse. The presence of Bradysia sp was noticed in the second fortnight of August, 2005. The symptoms in strawberry and the probable consequences in terms of disease arising were described in the present study, as well as the morphological characterization of Bradysia sp. and its illustrations.

  9. Spectroscopic Study of the CP43′ Complex and the PSI–CP43′ Supercomplex of the Cyanobacterium Synechocystis PCC 6803

    OpenAIRE

    Feng, Ximao; Neupane, Bhanu; Acharya, Khem; Zazubovich, Valter; Picorel Castaño, Rafael; Seibert, Michael; Jankowiak, Ryszard J.

    2011-01-01

    The PSI-CP43' supercomplex of the cyanobacterium Synechocystis PCC 6803, grown under iron-starvation conditions, consists of a trimeric core Photosystem I (PSI) complex and an outer ring of 18 CP43' light-harvesting complexes. We have investigated the electronic structure and excitation energy transfer (EET) pathways within the CP43' (also known as the isiA gene product) ring using low-temperature absorption, fluorescence, fluorescence excitation, and hole-burning (HB) spectroscopies. Analysi...

  10. Analysis of the chromosome damage and repair kinetics in CHL cells after 6'0Co γ-irradiation by PCC technique

    International Nuclear Information System (INIS)

    The kinetics of chromosome damage and repair was determined by PCC. Chromosome damage repair was not detectable until 30 min after irradiation and nearly half of chromosome damage was repaired by 6 h. In contrast, significant DNA repair occurred at 5 min after γ-irradiation measured by FADU technique. These results suggest that the early repairing DNA SSBs are not important in the formation of chromosome aberration, the different repair kinetics between DNA and chromosome damages might reflect their different repair mechanism

  11. Ultraviolet stress delays chromosome replication in light/dark synchronized cells of the marine cyanobacterium Prochlorococcus marinus PCC9511

    Directory of Open Access Journals (Sweden)

    Blot Nicolas

    2010-07-01

    Full Text Available Abstract Background The marine cyanobacterium Prochlorococcus is very abundant in warm, nutrient-poor oceanic areas. The upper mixed layer of oceans is populated by high light-adapted Prochlorococcus ecotypes, which despite their tiny genome (~1.7 Mb seem to have developed efficient strategies to cope with stressful levels of photosynthetically active and ultraviolet (UV radiation. At a molecular level, little is known yet about how such minimalist microorganisms manage to sustain high growth rates and avoid potentially detrimental, UV-induced mutations to their DNA. To address this question, we studied the cell cycle dynamics of P. marinus PCC9511 cells grown under high fluxes of visible light in the presence or absence of UV radiation. Near natural light-dark cycles of both light sources were obtained using a custom-designed illumination system (cyclostat. Expression patterns of key DNA synthesis and repair, cell division, and clock genes were analyzed in order to decipher molecular mechanisms of adaptation to UV radiation. Results The cell cycle of P. marinus PCC9511 was strongly synchronized by the day-night cycle. The most conspicuous response of cells to UV radiation was a delay in chromosome replication, with a peak of DNA synthesis shifted about 2 h into the dark period. This delay was seemingly linked to a strong downregulation of genes governing DNA replication (dnaA and cell division (ftsZ, sepF, whereas most genes involved in DNA repair (such as recA, phrA, uvrA, ruvC, umuC were already activated under high visible light and their expression levels were only slightly affected by additional UV exposure. Conclusions Prochlorococcus cells modified the timing of the S phase in response to UV exposure, therefore reducing the risk that mutations would occur during this particularly sensitive stage of the cell cycle. We identified several possible explanations for the observed timeshift. Among these, the sharp decrease in transcript levels

  12. SP-100 advanced technology program

    International Nuclear Information System (INIS)

    The goal of the triagency SP-100 Program is to develop long-lived, compact, lightweight, survivable nuclear reactor space power systems for application to the power range 50 kWe to 1 MWe. The successful development of these systems should enable or significantly enhance many of the future NASA civil and commercial missions. The NASA SP-100 Advanced Technology Program strongly augments the parallel SP-100 Ground Engineering System Development program and enhances the chances for success of the overall SP-100 program. The purpose of this paper is to discuss the key technical elements of the Advanced Technology Program and the progress made in the initial year and a half of the project

  13. Caracterización citomorfomérica de Anabaena circinalis (Cyanophyta en una proliferación masiva en el embalse Paso de Las Piedras (Provincia de Buenos Aires, Argentina Cytomorphometric characterization of Anabaena circinalis (Cyanophyta from a bloom in the lake Embalse Paso de las Piedras (Buenos Aires Province, Argentina

    Directory of Open Access Journals (Sweden)

    Gimena Argañaraz Bonini

    2005-07-01

    Full Text Available El objetivo principal de este trabajo fue realizar un tratamiento estadístico de los caracteres morfológicos de los individuos de Anabaena circinalis presentes en una proliferación masiva del Embalse Paso de las Piedras (Buenos Aires, Argentina cuya identidad se determinó mediante técnicas moleculares. Se plantearon como objetivos específicos de este trabajo: 1 analizar las dimensiones celulares y parámetros estadísticos de centralización y dispersión; 2 analizar la posición relativa de los heterocistos y las acinetas en el tricoma; 3 analizar la composición porcentual de los distintos tipos de células del tricoma; 4 analizar relación entre valores promedio del ancho y largo celular; y 5 analizar la variación del largo celular en células vegetativas de diferentes tricomas. Los resultados obtenidos sugieren que en condiciones eutróficas: 1 es posible caracterizar a los individuos de Anabaena circinalis mediante parámetros estadísticos referidos a las medidas de las células vegetativas de los tricomas, 2 el criterio basado en los caracteres morfológicos de las acinetas inmaduras no debe ser utilizado para ese fin, dadas la no-maduración de las acinetas en condiciones eutróficas y la tendencia a la uniformidad morfométrica entre las células vegetativas y las acinetas inmaduras, y 3 los heterocistos y las células vegetativas, uniformemente esféricos, sólo pueden diferenciarse entre sí por su tamaño y no por su forma, mientras que ambos a su vez pueden diferenciarse de las acinetas ovoidales por su forma. En cuanto al análisis de la varianza del largo de las células vegetativas, los resultados obtenidos confirman que todos los tricomas pertenecen a una misma especie.The principal goal of the work was to make a statistical analysis of the morphology of individuals of Anabaena circinalis growing in a bloom in Embalse Paso de las Piedras (Provincia de Buenos Aires, Argentina, identified by a gene probe for this species

  14. Biodosimetry estimation using the ratio of the longest: shortest length in the premature chromosome condensation (PCC) method applying autocapture and automatic image analysis

    International Nuclear Information System (INIS)

    The combination of automatic image acquisition and automatic image analysis of premature chromosome condensation (PCC) spreads was tested as a rapid biodosimeter protocol. Human peripheral lymphocytes were irradiated with 60Co gamma rays in a single dose of between 1 and 20 Gy, stimulated with phytohaemaglutinin and incubated for 48 h, division blocked with Colcemid, and PCC-induced by Calyculin A. Images of chromosome spreads were captured and analysed automatically by combining the Metafer 4 and CellProfiler platforms. Automatic measurement of chromosome lengths allows the calculation of the length ratio (LR) of the longest and the shortest piece that can be used for dose estimation since this ratio is correlated with ionizing radiation dose. The LR of the longest and the shortest chromosome pieces showed the best goodness-of-fit to a linear model in the dose interval tested. The application of the automatic analysis increases the potential use of the PCC method for triage in the event of massive radiation causalities. (author)

  15. Organic Nutrition of Beggiatoa sp

    OpenAIRE

    1981-01-01

    Culture OH-75-B of Beggiatoa sp. differed significantly from any described previously in its utilization of organic carbon and reduced sulfur compounds. It deposited internal sulfur granules characteristic of Beggiatoa sp. with either sulfide or thiosulfate in the medium. This strain (OH-75-B, clone 2a) could be grown in agitated liquid cultures on mineral medium with acetate as the only source of organic carbon. The resultant growth yields and rates were comparable to those for typical heter...

  16. CyDiv, a conserved and novel filamentous Cyanobacteria cell division protein involved in septum localization.

    Directory of Open Access Journals (Sweden)

    Dinka eMandakovic

    2016-02-01

    Full Text Available Cell division in bacteria has been studied mostly in Escherichia coli and Bacillus subtilis, model organisms for Gram-negative and Gram-positive bacteria, respectively. However, cell division in filamentous cyanobacteria is poorly understood. Here, we identified a novel protein, named CyDiv (Cyanobacterial Division, encoded by the all2320 gene in Anabaena sp. PCC 7120. We show that CyDiv plays a key role during cell division. CyDiv has been previously described only as an exclusive and conserved hypothetical protein in filamentous cyanobacteria. Using polyclonal antibodies against CyDiv, we showed that it localizes at different positions depending on cell division timing: poles, septum, in both daughter cells, but also in only one of the daughter cells. The partial deletion of CyDiv gene generates partial defects in cell division, including severe membrane instability and anomalous septum localization during late division. The inability to complete knock out CyDiv strains suggests that it is an essential gene. In silico structural protein analyses and our experimental results suggest that CyDiv is an FtsB/DivIC-like protein, and could therefore, be part of an essential late divisome complex in Anabaena sp. PCC 7120.

  17. CyDiv, a Conserved and Novel Filamentous Cyanobacterial Cell Division Protein Involved in Septum Localization

    Science.gov (United States)

    Mandakovic, Dinka; Trigo, Carla; Andrade, Derly; Riquelme, Brenda; Gómez-Lillo, Gabriela; Soto-Liebe, Katia; Díez, Beatriz; Vásquez, Mónica

    2016-01-01

    Cell division in bacteria has been studied mostly in Escherichia coli and Bacillus subtilis, model organisms for Gram-negative and Gram-positive bacteria, respectively. However, cell division in filamentous cyanobacteria is poorly understood. Here, we identified a novel protein, named CyDiv (Cyanobacterial Division), encoded by the all2320 gene in Anabaena sp. PCC 7120. We show that CyDiv plays a key role during cell division. CyDiv has been previously described only as an exclusive and conserved hypothetical protein in filamentous cyanobacteria. Using polyclonal antibodies against CyDiv, we showed that it localizes at different positions depending on cell division timing: poles, septum, in both daughter cells, but also in only one of the daughter cells. The partial deletion of CyDiv gene generates partial defects in cell division, including severe membrane instability and anomalous septum localization during late division. The inability to complete knock out CyDiv strains suggests that it is an essential gene. In silico structural protein analyses and our experimental results suggest that CyDiv is an FtsB/DivIC-like protein, and could therefore, be part of an essential late divisome complex in Anabaena sp. PCC 7120. PMID:26903973

  18. Optimal spænding i kajakken

    DEFF Research Database (Denmark)

    Rossing, Niels Nygaard

    2012-01-01

    Artiklens overordnede fokus er, hvilken betydning den enkelte kajakroers spændingsniveau har for præstationen. Artiklen svarer på, hvad et spændingsniveau er, hvilke kilder der er til spænding, og sidst hvad man kan gøre for at finde sit optimale spændingsniveau....

  19. En moderne spøgelseshistorie

    DEFF Research Database (Denmark)

    Simonsen, Karen-Margrethe

    2011-01-01

    Anmeldelse af César Airas "Spøgelserne". Anmeldelsen indkredser bla. spøgelsernes karakter i denne moderne, interkulturelle historie......Anmeldelse af César Airas "Spøgelserne". Anmeldelsen indkredser bla. spøgelsernes karakter i denne moderne, interkulturelle historie...

  20. Fungi Association with Cedar’s Seeds and Fusarium sp. and Pestalotia sp. Pathogenicities Levantamento de Fungos em Sementes de Cedro e Avaliação da Patogenicidade de Fusarium sp. e Pestalotia sp.

    OpenAIRE

    Sílvia Cristina Benetti; Álvaro Figueredo dos Santos; Antonio Carlos de Souza Medeiros; David de Souza Jaccoud Filho

    2010-01-01

    This research had as main objectives the evaluation of cedar’s seeds seed-borne fungi and the Fusarium
    sp. and Pestalotia sp. pathogenicities. For the fungi detection Potato Dextrose and Agar medium and Blotter
    test methods were used. For the pathogenicity tests, isolates of Fusarium sp. and Pestalotia sp. were used. The following fungi were observed: Pestalotia sp., Fusarium sp., Phomopsis sp., Colletotrichum sp., Macrophomina sp. and Cladosporium sp. The fungi...

  1. Effects of essential oils and plant extracts of several plant species on the growth of Anabaena cylindrica (Cyanophyta) and Cholorella vulgaris (Cholorophyta)

    OpenAIRE

    Monteiro, Liliana; Geraldes, Ana Maria; Barros, Sandra De; Fernandes, Conceição

    2011-01-01

    In the future, the use of plant extracts to control phytoplankton growth might be a promising algal management tool in aquatic ecosystems, dua to its low cost and environmental safeness. In the present research, effects of aqueous extracts and essential oils from rosemary (Rosmarinus officinaLis), lavender (Lavandula sp.), poplar (Populus sp.), ash (Fraxinus angustifofia), laurel (Laurus nobilis), mint (Mentha suavolens) and elder (Sambucus nigra) on the growth of axenic cultur...

  2. Laser Flash-Induced Photoreduction of Photosynthetic Ferredoxins and Flavodoxin By 5-Deazariboflavin and by a Viologen Analogue

    OpenAIRE

    Navarro, José A.; Hervás, Manuel; Pueyo, José J; Medina, Milagros; Gómez-Moreno, Carlos; Rosa, Miguel A. de la; Tollin, Gordon

    1994-01-01

    Lase flash photolysis has been used to compare the kinetics of reduction of ferredoxin isoforms from the green alga Monoraphidium braunii, and the ferredoxin and flavodixin from the cyanobacterium Anabaena PCC7119, by 5-deazariboflavin semiquinone ((dRfH)

  3. Interference of Quorum Sensing by Delftia sp. VM4 Depends on the Activity of a Novel N-Acylhomoserine Lactone-Acylase.

    Directory of Open Access Journals (Sweden)

    Vimal B Maisuria

    Full Text Available Turf soil bacterial isolate Delftia sp. VM4 can degrade exogenous N-acyl homoserine lactone (AHL, hence it effectively attenuates the virulence of bacterial soft rot pathogen Pectobacterium carotovorum subsp. carotovorum strain BR1 (Pcc BR1 as a consequence of quorum sensing inhibition.Isolated Delftia sp. VM4 can grow in minimal medium supplemented with AHL as a sole source of carbon and energy. It also possesses the ability to degrade various AHL molecules in a short time interval. Delftia sp. VM4 suppresses AHL accumulation and the production of virulence determinant enzymes by Pcc BR1 without interference of the growth during co-culture cultivation. The quorum quenching activity was lost after the treatment with trypsin and proteinase K. The protein with quorum quenching activity was purified by three step process. Matrix assisted laser desorption/ionization-time of flight (MALDI-TOF and Mass spectrometry (MS/MS analysis revealed that the AHL degrading enzyme (82 kDa demonstrates homology with the NCBI database hypothetical protein (Daci_4366 of D. acidovorans SPH-1. The purified AHL acylase of Delftia sp. VM4 demonstrated optimum activity at 20-40°C and pH 6.2 as well as AHL acylase type mode of action. It possesses similarity with an α/β-hydrolase fold protein, which makes it unique among the known AHL acylases with domains of the N-terminal nucleophile (Ntn-hydrolase superfamily. In addition, the kinetic and thermodynamic parameters for hydrolysis of the different AHL substrates by purified AHL-acylase were estimated. Here we present the studies that investigate the mode of action and kinetics of AHL-degradation by purified AHL acylase from Delftia sp. VM4.We characterized an AHL-inactivating enzyme from Delftia sp. VM4, identified as AHL acylase showing distinctive similarity with α/β-hydrolase fold protein, described its biochemical and thermodynamic properties for the first time and revealed its potential application as an anti

  4. Protein (Cyanobacteria): 170237 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 8802_4468 Cyanothece sp. PCC 8802 MNFDFPSPISPDSSKQQELSPKKLNPSRIRDHLANERTYLAWMRTAVGLMGFGVVILRIRAFQPPSIPGPGFGWKLGLIFAGVGLLTVLLSTVQYFIVRRDIEEDTYEPPDRWVILFSLTIALLGSGIIYFVSTSSFDLVDIIM ...

  5. Protein (Cyanobacteria): 170238 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 01_4405 Cyanothece sp. PCC 8801 MNFDFPSPISPDSSKQQELSRKKLNPSRIRDHLANERTYLAWMRTAVGLMGFGVVILRIRAFQPPSIPGPGFGWKLGLIFAGVGLLTVLLSTVQYFIVRRDIEEDTYEPPDRWVILFSLAIALLGSGIIYFVSTSSFDLVDIIM ...

  6. Protein (Cyanobacteria): 20524 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 375DRAFT_4878 Leptolyngbya sp. PCC 7375 MELYERIEQIIVTFRPAFSRNATFGWFVLLLWGALLTTQPPAVTSYLNALGLGAEYYHQALHWFHSSGYEMDRVCRRWGRWLSHQTDGYRLKGHRVYVGDGIKVSKEGRKMPGLKACIKSPITSVNQNGYGGIILVRWAF ...

  7. Protein (Cyanobacteria): 26104 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available GQQRLTSLSLLLIFLNNLQKKTSSKTINIESLILSENIFGKSFNLDVPERNACMEALFIDEPFDATQQPDSIVNLVERYNDIEELFPEEIRHEALPFFIFWLQTKVLLVEIE...WFIDSWLNRRLWHFKSNSYSNMSYGIFQITKKIRGLDVETLRTTLIQRFEEVISAEKLDFSNHLYLHKQNSKTLHRQLARMMDWLERECGMNGNYQQYIVRSGKNAYEIEPEVLNDSYKEKKSPLK ... ...echocystis sp. PCC 6803 MQEIQGKTRTVQELLGNAKYGIDYYQREYQWQTKNISELIDDLTNRFLEDYQPGDGETEFAKYGYYFLGSILISVNDTKKFIVD...DIRDRKKDAKPKDFDLIGTEYHRWIRNNAESVGLKTSNSFFKWINNDLNFYARIYKQLLDASKGLTEGWERVRYNADHGFTLQFQLLMAPLQSSDTEEIIKQKVALVA

  8. Protein (Cyanobacteria): 270128 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available family 2 Calothrix sp. PCC 7507 MQSIGIVVIGRNEGNRLHQCLLSVVGEGITVVYVDSGSTDGSVTLARSLGAYIVELDLSIPFTAARARNSGFAYLLQIEPNIE...FVQFVDGDCRVVEGWLELAQRELLTQHDVVVVCGRRREEFPNNSIYNLLCDIEWDTPIGEALACGGDSMMRVTALKNVGGFNPTLIAGEEPELCVRLRQAG...GRILRIDAEMTLHDAQITRLSQWWKRSLRGGHAYAEGSWLHGAAPERHWVRESQRIWFWGLLLPFLAIAAVWSTKGLSILLLLLAYTFLAYRVYQNTRQRGLNTREAISYSLFCVLDKFPQLQGQIQFHLSRLFRQQRTLVEYKN ...

  9. Protein (Cyanobacteria): 197941 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available LVLWVGASLVLDGDLTLGQLIAFRIIAGYVTSPILRLTQLWQNFQETALSLERLADIVDTPQESERDRQNIPMPEIAGEVKFENVSFRFKKQGPLQLNNINLSFPPGT...IVVMIIYSPLLTAVALGIVPIFVILTLVFSPLIRRQLRLKAERNAQTQSYLVEVMSGIQTVKAQNIELRSRWQWQDKYSRYVGAGFNTVITSTLASSSSHFLNQLSGL... sp. PCC 6803 MSLTIADYQSFLREIEPFAQLPAPAIAEIAAKLRPLRFRMGQIILARGKLANNVYFLVSGQARLLGYDPGTGYPATMALLQNGAVIGDNNAIRN...VPCETAIASTETICASLTRDEFLALVDKYPELARVYRHQCGRVELFDLLGEQLQRTAQGNVDLRQLTLEMLPQSQVYELQPGSHSLPSDLPDPERLWLVSSGELEQCP...RGSALPDPDSALVLKAQTLVRLIGLPPLPRFFPGSSGSKTNGNGNGHGEVPLATVTRLAPEDSPWDDIPYADPNQLGEPLPEP

  10. Protein (Cyanobacteria): 156191 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available onent I Cyanothece sp. PCC 7424 MISPTFAEFESLAKQGNFIPVYREWIADLETPVSAWYKVCAGEEYSFLLESVEGGETIGRYSFLGCEPMWVLEARGNTTTQTYRNGNIER...YSHVMHIVSNVVGELAPHKTAWDLLKACFPAGTVSGAPKIRAMEIIQELEPERRGPYSGVYGYYDFEGQLNSAITIRTMIVRPVSANQYIVSVQAGAGLVADSIPEKEYEETLNKARGLLEAIRSLK ... ...FEGNPFEILSSCIDPIKPVKLPQLPPGIGGLFGYWGYELIRWIEPRVPIGEATEKDLPDGIWMQVDNLIIFDQVKRKIWAIAYGDLRDETVSLE...KGHPFDLYRSLRLINPSPYMGFYQFKDWQIIGSSPEVMVKAELNENKTLKATLRPIAGTRPRGKTLAEDLAFEKDLLQDPKEIAEHIMLVDLGRNDLGRVCMKGTVKVDQLMVIER

  11. Protein (Cyanobacteria): 462892 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available I7407_2252 Geitlerinema sp. PCC 7407 MRFKLLVSGLVTAAAIALSGTGAEAQTLMRTGLMRNVLVDALANRSTVFSSGVLADLETDENFGGDYQQIFDYASGILNDYTVVDRGGVFPENAGIPRDRQLPRTDVVYTVFTLDNGNELFLYRSPLEDTARYFIRESVPFGG ...

  12. Protein (Cyanobacteria): 45533 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available LPYEVCGLLARACGQVKGNLPRLDKIRAIEFARAFFQIPIQISTAVEDECIAAVGMAVDYAKGSYDMTYIRLAETLNCQWCTADEQAIRVVPSGFPLHRVLLLSTLR ... ...ding protein, contains PIN domain Microcoleus sp. PCC 7113 MNLPERLVIDASVAAKWFLRDAIESDVDLASDILLASLADEVELHAPQI

  13. Protein (Cyanobacteria): 69673 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 375DRAFT_4511 Leptolyngbya sp. PCC 7375 MDDWLKQLQQDLQEAVHSTLEQTEQFLDVLAEQAVDVVSPVLDAADELADELAEQVVENISPPISQALDE...LETQLDPVVGSVVSWCEQTMAPLHQTLTPWLQNHPKCAGCSYYHGESYGGQMLVCALHPHGPEDYDECPDWESVWPKPDGD ...

  14. Protein (Cyanobacteria): 52198 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 02412 Synechococcus sp. PCC 7502 MKLTPYLFLTITVTAIIGTSVWQSSAQMNKMMNHNMDEMSMELGAADANLDLRFIDAMIPHHQGAVQMAKEALKK...SKRPEIQKLATAIIKAQQEEIAQLQKWRKLWYPNMSSTPMAWHGEMGHMMTMSASQQKAMMMSMDLGAGDAKFDLRFIDAMIPHHEGALTMAQEALSKSKRPEIQKLAKAIITSQKAEIIEMQKWRKAWY ...

  15. Protein (Cyanobacteria): 52216 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available DUF305 Gloeocapsa sp. PCC 7428 MLLKKRFALNIVAIAATGGFIASCAAVPPTPTPRANTQSTQQMPHHGMNHAMAMDLGPADANYDWRFIDAMVPHHQG...AVEMAQAALEKSQRAEIKELATEIIAVQQREIAQLQQWRQAWYPQASNTPVAYNPQTGETVPMSQQQMHSMMMHGDLGAADAEFDRRFIDAMIPHHEGAVIMAQDALNKSQRPEIRKLAQEIINSQEAEIKQMQAWRQAWYQQ ...

  16. Protein (Cyanobacteria): 348661 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available C7001_197 Cyanobium sp. PCC 7001 MSPGADLPDLNVWLALASSQHIHHRQALHYWEQLAAEQVLFCTVTALGLVRLVSQPRLMGDAVKNAAEASELLAAFCRQPGVALAPAEHDGWDVFHRLMRKGELPPRLCTDAHLAALAMTHGWRLVSFDRDFKRFEGLHWLALS ...

  17. Protein (Cyanobacteria): 322932 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 7113_6178 Microcoleus sp. PCC 7113 MDVIALTAFLTPFLPFLIKFGEKSAESVATKFGEDSWNKAKKVWGKLQPKVEAKEDAKSAVNLVSTDPEDEDYRKVFQKQLKKLFDEDQELAEAIAQIMQEKSEATSGTQINQTIQNTKGQVTGQQTGGKSIGNIDAIHGDVNL ...

  18. Protein (Cyanobacteria): 221364 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available DGTNPIYAIIETATPKKYEILLGFSPDCTGGTACRLGVVSAEAVTRSTPRLKGRRVALAKGIAGYFVDFRCGANCSDATLTWRQQGVQYSFGLKAGDRNSLIKMANSAINP ... ...n all1130 Nostoc sp. PCC 7120 MIFGLKSLTNLSILLILVGSNNFYPSAIANTNNQPQLSAQRPARTANSQPHKVFQPILPKLKQKSQIKILLPKYIPES

  19. Protein (Cyanobacteria): 47561 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 76_2553 Leptolyngbya sp. PCC 7376 MGCKREKSSKSVFKKQDSCGTFILFRFSGVTVTMSCNTLDALQYPLNLNQSLVPRPSDTFFFIVEGESGKFLGLDEGDLLVVDRTVSIAPDQMAIAVYDGQFALVQLIEEHKDLSVRLSEKSVKLFADTDLDIWGIVTGLVRQF ...

  20. Protein (Cyanobacteria): 343751 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available c7113_6022 Microcoleus sp. PCC 7113 MNEEAQKCQLIMGQGYFAPTSNHFSANYYPSINLPMRSPNTQPLLHYHAKSAWENGLGYLVDSRGISLPGIT...SILKATKSPQEKAQLSNWRQRVGASEANRISRTSRDRGNLIHKLTKSYFLGESFSCPDSIKPYWDNLLPILQDIHDVRLIEGNVFHYYEGYAGRVDCVASYHGIPCVI

  1. Protein (Cyanobacteria): 16733 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available SLRIGAKPEVILANNRPFEEILRTSSASADLVFLGLAVPHEGGYQAYYQTLQDRVVGLPATVMVLASENLDFSELLQKDVS ... ...LQSPSFRPTFKVHWSLSVLGAIGCIAVMFLINPVATIAALVIVGLIYFWLERRQIESTWGDVRQGIWMTVVRTALLNIDDNADPKNWRPHLLVLSGAPSKRWYLIEMARALTHNRGLI...DPDIESIERYCNTIRVCHGAKRNVVIYRDESGADAPDSLHPPMYADQADQRIDVWWGGLQSNGGLMLILAYLLRTSWQWRSAEIRLKLVVSDEEALEAAEVNLENLTN...echococcus sp. PCC 7335 MTLQSPHPSTLDTQDEAIGLGTFGGVFTPSILTILGVIMYLRFGWVVGQVGLYPTMAIVTIATSITFLTALSISAIATDQVVRAGGAYYMISRSLGIETGG...KIERVGFWAVFAVFFPAVTGIMSGVNMSGDLKDPIRSIPRGTLAAVIVGYIIYMAIPFVLVSRTPTASNALLNPEMMVMKRIAIGGHLLI

  2. Protein (Cyanobacteria): 57220 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available mate transport system, periplasmic component Nostoc sp. PCC 7524 MKIEQILLLIIFTFIIITGCYNYLPQNNTILRSNSDASECKIIKHELGESCIPL...KDALSSIAEITGKSTQAQKLLEQYQQRVQELRQVINHQLKKTTVSVSRFYAGNQVPEFRTKYSFPGSLLMELGIPLPEMQN

  3. Protein (Cyanobacteria): 446991 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available VTHDLEFERWCNKVWNYGSGLGAEVSLADFRKDIIIELMNEAGQVAIAYKVYRCWPSECQALPELDANANAIAFEMVTLQNEGFERDLDVVEPSEPSFVEP ... ...n protein Leptolyngbya sp. PCC 7375 MAQFSVNAQRFDPYKNFKFRVKWDGRYVAGVSKVGALKRTTEVVEHREGGDPSTVRRSPGQSKFEAITLERG

  4. Protein (Cyanobacteria): 279748 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available PATGVAAGAMKGETRTQTAATVPVMPRRPAPPRSPAATRAAAPKPRTAAPPRRSPSPAAPRRTGDPASFPMALFGLIALAVIIGSAIAAFQIQRDRPSAPSPSPAPETPSSEPSPSIAPPIDLAPPEPSE...SPSPEPSVPPEPSPPSPEPSESPSPSPEPTASPSPEPTVSPSPEPVEESPAPEPSPEPPVEPVPPEPEPVPPEVVNPEPVEPAPPPAEPQPPV ... ...ase Geitlerinema sp. PCC 7407 MNSLVGQTLQNGKYTLQEEIGRGGFGVTYKATHHYLGQWVVIKTLNEGMHNHPDFQASEQKFQDEARRLAACSHPNIV

  5. Protein (Cyanobacteria): 446977 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available ITLERGVTHDLDFEKWANKVWSFNNAQAPADSRTQEVSLADFRKDIIIDVYNEAGQKVISYNVFGCWVSEYQALPELDASANAVAIQSITLQNDGWVRDESVVEPSEPSYEDPAA ... ...othetical phage tail region protein Rivularia sp. PCC 7116 MAQFSVNANRFDPYKNFKFRVKWDGKYVAGISKVGMLKRTTEVVEHRVGGDPSTVRTSPGQSKYEP

  6. Protein (Cyanobacteria): 472152 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available ATETESTTEDPSATETETETDPSATETESTTEDPKIMKTSPDADSTSPSGSMEESSPSGTIGEPSSSPSEPGTGSTTSPSGTTAPVESPSGTGQ ... ...otein Ple7327_0897 Pleurocapsa sp. PCC 7327 MKSRSRITFFNLLASLLGATGASIMLGLPTLAQMPESSGTVGSPTEATEAGSSTTPGSGMEVESESTGTPSTSETETETDPS

  7. Protein (Cyanobacteria): 91708 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 5DRAFT_1667 Leptolyngbya sp. PCC 7375 MSSADSRPPEMSNTSSDHNSDASAAANSDSPALKKPPRRPAKPVAPVEEPPKKPTIEAVALKKADALEPTPIVSEPDPKPTESEPTEPSVAEP...PVEDTPTEPETPQPRLQPIAPPSEPMQYRAIGLLKGRYEPSEETFNRGNIVNHDGTTTCAVLLGRTTSLVKKHLDLEKDHLWVVYPRTIFQDDIGMAVQIVGVWEP...INGNIGVKTIGYFWDMHVQRQGNQLILTDGSYVGAVPPKKRSKKKPMGGGGGGGKRRPPSSKRGGRPKPNLVKDDAAKVEKPNADAPKVVKVGNSNEVVDAERSEG ...

  8. Protein (Cyanobacteria): 140857 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available protein Synechococcus sp. PCC 7335 MLRLFEELQPSVVYDYFSHLILQSRCLALSMSLSAACQAQHAKENAITRKWLLVGFVIAVVTPIGLLPLLRFVLPGTSEPS...GESGTIAVDFQINGGNSQSQPSTQETSPGASPATPSNEPTRVNSSEPAAEPTVKPTAASATGPASNQQLVNTQPPDIRGTAASMDATAGAADLADIPSTNLETAPESFEVTSPTTELEPEPTPVPAVAEPPASEPLESEPPASEPPGAEALLSEPDF ... ...AAVSQASGSNIAARGSSATNQPTSTTESGIDRPGASALGPSIARRRQEPISCRYCDPTALLGETASSGARVEPSVRLEYDSDGNVVGARIERSSGDASVDRAAVNAALTFAFNNPS...ARISISIVGPADLQGEIVEAASPPKEVFDFINTAEPTATQRPTDSAPLESGSAITSPTAIRSAPLPTQTSESSSNRSSSNRSSSNRSNSNSESAAAETLDRAPADRTEAHATSEALDNTASE

  9. Protein (Cyanobacteria): 130081 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available n all1672 Nostoc sp. PCC 7120 MFKILFDSDLILDAVMNRTELAEDVRTLLENLHPSIRLYLTDVGLQKVSTYTYCLKNSQIPEIIVDWLQEQIQICPIDQGLLQKARYSPLRDFESAVELACINHYQLNAIVTNKPEDFIVTAHPLCVWSFADLWLRVNLESQLQATIHS ...

  10. Protein (Cyanobacteria): 247172 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available in Synechococcus sp. PCC 6312 MSQSLLNFVFRIFDRFMRDYEKFKIKRMKSCFKSCGNNVEINNVTITPWPKVEIGSNVIINSYTNIFAGGGVIIGSGTLISSN...CVIVSVTHPTDTTDRFNAECIRKPVTIGQNVWIGAGVIVLPGVHIGDNSVVGAGAIVTKDISSNTIVVGNPARTLRTMEF ...

  11. Protein (Cyanobacteria): 187385 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available etical protein Cal6303_4112 Calothrix sp. PCC 6303 MQGFLKSVMTISALSSLVIAPVLLSAGEASAMPKERGTNASYVGGGISAGLTNGGKNGDAATFGGNVAARAKLGNLPVSA...RGQINFSDETSAIIPNVTVDIPILRGTNLYLGGGYQFVEKNGKPTPSGNKDGIAAIAGIESEVARNFLIYSNATVGINAYQNSSASSVSINSGVGFRFK ...

  12. Protein (Cyanobacteria): 467434 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available FPEFDSQSQPEKTEDKNSLENLMLKKATTSYESISAGEKIQVKISDDGVKHIIYNAEFSPLESKEMHTAIYSSASSQRRKVPEPSAMLGLIAFFLLAAKRQKEKGSQTAAQ ... ...protein Riv7116_1449 Rivularia sp. PCC 7116 MTLTINNIRNFALLGTIISASATAPAQAGLPKNINSDDDLTKASEKQTPFENQDILSDKQKCNPTDLCIS

  13. Protein (Cyanobacteria): 64020 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available Leptolyngbya sp. PCC 7376 MFRPLQRLGRHPWLVSVFLWLAMLAPAQAAVDMRIAVSKSAPRVQVGSSTNALVKNGRGQLLGEISAMSAFSVNRQGNQLAF...STTHEAVKATTNQVMTYNGDVILAVFHSSSGGHTENVEDVWTRPLPYLRGVVDYDQSAPVYQWGKNISASRLGQLIGGVGT...VKQIIPQRKTPQGRMVSVKIVGDRGTKNISGDQLRKLLDLRSTLISATIQDGNVYIYGKGFGHGVGLSQWGANGLAQQGIDYQQILAHYYQNVNIAKILK ...

  14. Protein (Cyanobacteria): 190190 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available protein Leptolyngbya sp. PCC 7375 MQIYLDYSATTPPRAEVMAAMGSAMKHSWGNPSSLHNWGSRAATVMETARMQVADLMGASGDAVVFTASGTEANNLAIMGVAQQYRKPRHMIISA...QRLLKLRDRLIEQLQCHPELLLTGHPQQRLPHHVSFYLPNANGEQVSGKTLVRQLNLAGIGISAGSACHSGKLTPSPILQAMGFSNIAAKTGIRLTLGHQTTEADVDWTAMVVRQIIERVMMRQLVTAGVK ... ...VEHSAIAKPITLLEQWGWQITRLPVDSYGQVHPIDLAQALREDTVLVSVIYGQSEVGTIQPITELAAVIKASDHISTPLFHSDAVQVAGRLPIDVQKLGVDLLSIS

  15. Protein (Cyanobacteria): 379652 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available tion DUF1817 Geitlerinema sp. PCC 7407 MTLKIHLTSDALYSLDLSPAEAVLQPLLAEGISAYEQQLQFSIDFPRDSADPRELSEIPEVRLWFVRLDSRYPWLPYLLDWKAGELGRYSAM...LVPHQFSPTEGIQYNPEALEIFLMHKIFVLADWMASQGISAQPRLQGFAQMLGYDLDEGLFSLVCR ...

  16. Protein (Cyanobacteria): 423162 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available brane protein of unknown function Calothrix sp. PCC 6303 MNITSILVAWLVTSASFFVISKLPIGVDIDSPDKTFVSAAVLGIISALVRPLLSFIFQVPNALTFNIFPAFFTFAISAMCFGLAASFVQGFRLRFGAWSAILGAFSLSVVTNLIYQIIPF ...

  17. Protein (Cyanobacteria): 355573 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available RKFPDVFDQLFLSMVGAGEVGGVLDEVLERLAVLMEKNHKTQSEIKSAMSYPKTVLFIAIIIFFAMTIFLLPTFAKIFKDIGADLPAFTLFMLSISA...rotein Oscillatoria sp. PCC 6506 MATNVLREKPKAGLSFEAISHKIELAMSSVTIKDLAIFARQFAAMFNAGVAMVRCLAVLNEQCSNPKLKNALTSISADVEQGSELSTAM...FCTTWPPIPQMTVIGSLIGLSFAYKMYYKTPVGRLQIDKIMLKMPVLGDLLEKSAVARFCIIFGTLTRSGVPILNSLEIVRDVAGNQAIS...NAIEYARTQIMGGGMISIALQEQAVFPALAIQMMAIGEETGELDKMLMKVGAFYETEVEEAVKALTSMMEPLMIVVIGGIVASILLSMYLPMFAVFQKM ...

  18. Protein (Cyanobacteria): 345861 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available protein Riv7116_6552 Rivularia sp. PCC 7116 MKKINAKQKQWLISLHVVFSAMWFGTALCMIAIALINRDTPNGDELYAINSVMKLLDDVVIIPSA...FFSLLSGGLLCWLTIWGFFKHYWVIAKWIGTVTLIVTGSIWLGPWTNAMTAISAEQRLQALQNPLYVFDQKAVFIGAIIQTSSLLFIIAISFVKPWGKRDKKIQKQSSAI ...

  19. Protein (Cyanobacteria): 206538 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available LIWKAALNAALKARDQFGESRVYIQQFENLVTCPEPSLKSLTNWLTLDYEPSMHTVGLVNSSYSNSWSNGSGLSSEPAYRW...FEAYCQLCAQKKNKTIFGEKTPRHIFKIAEILNCYPDAKVICMVRNPGGVIASYRDFWKSQWRSDSSSKSLTEKRRIKNSYNLIIIS...QEKLSDAEVAIFQFCCGQQLLKAGYTKKQVQIPAILIIWLWLTLPFAGLRALLANSNRISNIPQYLWRRLRLVIG ... ...apsa sp. PCC 7428 MEESKNEIAKKSMIFIVGTSRSGTTLMRQILSKHSNVYISKETHYFDDLRVKMSGREQKPLSSQEIQVTEDYFLALTHKAYEAKGDPEQGWMDRMELRSLAQQIGCGTDSY

  20. Protein (Cyanobacteria): 227726 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available ENNDFGVTGVAYGAKIMPVKVLDDSGSGSYSAIANGIYYAVNHGANVINLSLGGDFPNSTLESAIDYASKKGVVVVMAAGNNGYPLVSYPAAYAN...LQYPTASFKLSSTNEVNSVTSRLIPISTSESQSLLANSEIESKFSYYDSTPSSNSYDSLAEDNGWTWKNY ... ...KSGIAVGAVDQNNKMADFSNQPGFSQLAYVTAPGVNVYSTVPGDQYAYYSGTSMATPHVAGVVALMLSANPNLSAEQVRQIITSTAANSSQSLSTSSNTGSLTHQIIADMTGNS... sp. PCC 7507 MPVNYTSQKSFANEGLDVTPLSSADIFHARDDDSLKLSGRSSFDATINDLKADSSNVQKSHSTEAKITSDATTKSYDSNSGYGLVNAGAAVAKS...IGQNTFADVPDLGGNNWGADLVKAPEAWAKGYTGQGVVVAVVDTGVDYNHADLKNNIWTNTKEIADNGIDDDGDGYIDDVRGWNFVNNTNEVMDDNSHGTHVSGTIAG

  1. Protein (Cyanobacteria): 267313 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available sferase Nostoc sp. PCC 7524 MSLVSVIIPVFNGEKTIRKTLDSILSQTLKDLEIIVINDGSSDSTEEIVKNISDERLQIFSYPNAGLPASRNRGVSHANS...EFISFIDADDIWTQNKLESQLKSILASESAAVSYSWTDYIDENGKIVKSGRRVTNVGDVYSKLLISNFLENGSNPLIRRSALATVGGFDESLTAAEDWDMWLRLAAHYDFVIVPEVQILYRISLNS...MSTNLKRQESASLIVIERAFSEPKALALQHLKKRSLAYLYRYLTFKALEANPAQQNSYLALKFLWKCIIHDPSFIKQIKLLSIALVKIYFSHIYYYLIQFKNKI ...

  2. Protein (Cyanobacteria): 161609 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available SQTVKAAKTPKPVILTLVVNWLIKPFTMVVFAQFFLGWLFLPLLKTTEFIHGQQITLANSYIAGCILLGIAPCTAMVLMWGYLSYSNQGHTLVMVAVNSLAMLFLYAPLGKWLLSAN...NLIVPWQTIVLSVLIYVGLPLAAGIYSRYWIFKHKGREWFERKFLHYLTPVAISALLITLILLFAFKGELIV...ein Cyanothece sp. PCC 7822 MANQNFPINPKAVKAGGTLSVFEKYLTVWVILCILAGIALGRFFPGVAQTLDAMSIYQVSLPIAICLFFMMYPIMVKIDF...SNPLHILLIAIPLFIQTNFIFLISYVAAQKLKFTYEDAAPAALIGASNHFEVAIATAVMLFGLNSGAALATVVGVLIEVPVMLMLVEVCKKTAFWFPREPEKASLLDPRCISSIK ...

  3. Protein (Cyanobacteria): 306970 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available AYGMEFIDELPNFNRGFDSSGSGALSRFGRYNTIYRSVDSGAGVIVNHKLNDAITLSAGYIVPDNNANDPANNRGLFNGSYTALGQINFQPTPQLGIGFTYANSYYSGGAVTGGSGVAVSGSTGTTFAN...DPFNGARTSSNSYSVAGTYRFSPQFTIAAWGGYTEATAENTISGATKGNTAEIWNWAVQLGFPDFGGEGNFAGIVFGAPPYAASNQYVSGTNRRTDSNVSYHLEAFYKYKLNDNIAVTPGFITIFDPEGNSSNPTSYVGVVRTTFTF ... ...alothrix sp. PCC 7507 MQKFWLNSLLFSPAVLGALMIFAVPIASAETPEPSAPTNDSTSLAQLTSVSQLSDVRPTDWAFQALQSLVERYGCIAGYPNKTFLG...NRALTRYEFAAGLNACLDQVNQLIAAATTELVTKEDLATLQKLQEEYAAELQSIRGQVDALEARTATLEAQQFSTTTKLRGEVIFALAGVFGDTRALNSDQVRSNAAR

  4. Protein (Cyanobacteria): 306781 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available TLNQGLDVGGGANGAITRFAERNPIFRFDLGGQGFGFKYLASDKLEFSAGYIANSGSDPDKGLTGGSYSALANLVFKPTDRFSAGLTYVRAYDEASGRRFNFGGTGTNFAN...NLASAFGDDVDSNLVFQSKLRMTFVTSFTGKDRLYTRLTGGNIANSFADEIGTNEGRFAYDGVSGNTIILDRFHYKFPVGDKLEVTAMAGLAGHHFYAN...LSSASGLPDIVTGSAVSSNSYGFQTKIDFSPRFSLRGWVGFTDAELRGVGSADILNYAIAMVFPDLFKEGSSGALIVGAAPYLTSLDAPGDPEFSEETPFHIEAFYKYRVSKNITVTPAIVWLTSPDQGRIDNDAFIGTVRTTFSF ... ...baena sp. PCC 7367 MHKVWLKMLAVSSAMLALPVMQAAAQTVKENLEIANEPASSSYVQEYFQQSQDNNIVSQSTLGVRPSSNQAQVTSVSQLSDVQPTDWAF

  5. Protein (Cyanobacteria): 295479 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available LPNPELFYQHFPHDRNKKLILFLGRIDPKKGLDLLASAFAKVHSQFSDTHLIIAGPDNIGFSQTAKNYFANSYCLEAVTFTGMLTGSLKYAALAAASLYVAPSYS...Cyanothece sp. PCC 7424 MKMKILIVTPSLGNIYGGPSKSVIELTQALGDQGVEVDLVTTNANGLSSLDVPLYEWIIKSTYRLQYFSYLSLNDYKFSWSLTKWLFQNVKHYDIVHTNAIFSY...EGFSMSVLEGMASGLPCVITTGCNFPEAAAEKAALVVDIDATQIANALLWCLKNPQQAKAMGDRARHLIFEKYTWEKIAASMISFYGKIIR ...

  6. Protein (Cyanobacteria): 45561 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 1669 Pseudanabaena sp. PCC 7367 MNRPSNRPKQPDRSDRPERPRRPPLNHPQRIHQPGEQLPEITGESPTKAKPRQNAAPLNQFAEENDATGFGEWIEHNSYS...LVTWIGYGLLGLALIDFTFTLVPPRLFDPGWQLDAVGQLVGKVWAPLLGMMLIFFRGRGRIGELEIKILGWVSWIPMIFAVVYLLLIPSTVANSYRLDKNNRDQANTQLVQRTQQISQLETTLAEAN...TAQEVGIVVAQVNRLPGIPRIEPDQVEPLKQELLEQLAAQKVAVETTTNTNIAISQKKLLKNAVRQVISTLLAGLLFLKIWQLSNWARQYSNVVRNQ ...

  7. Protein (Cyanobacteria): 459870 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available protein Riv7116_1034 Rivularia sp. PCC 7116 MVKQASFQSGVTTVEEPFFKLDNLNSYSQSFTSKYANLQCSQNHTTNTPVAECTFLQLDNLQCF...EVVDRQYESKGVLFSNCIAIEPSNPAFPPHSGLIVLMSSPKSGLLEATFVNPVHSVSAFVTSSQRLMLSAYDESRQLLDRAILPSGNLANSDSSLAPNTLLSVTAQNIHSICFHAFEAQFTVDDLSFSY ...

  8. Protein (Cyanobacteria): 161614 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available QAVKAAKTPKPVLLTLVINWLIKPFTMIAFAEFFLGYLFLPFLSETEIILGQSVSIANSYIAGTILLGIAPCTAMVLMWGYLSYSNQGHTLIMVAINSLAMLFLYAPLGKWLLAAN...in Cyanothece sp. PCC 8801 MSNSRPTLNPKAVKAGGSLNIFEKYLTLWVFICIVVGIILGRVFPDVAKTLDSFSLHQVSIPIAICLFFMMYPIMVKIDFS...NPLHIFFIAVPLFIQTNFIFLITYVVGLKLNLYYEDAAPAALIGASNHFEVAIATAVVLFGLNSGAALATVVGVLIEVPVMLMLVEFCKKTAFWFPREPEKATLLDPRCIKPFN ...

  9. Protein (Cyanobacteria): 161589 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available KRAAKTPKPVLLTLVVNWLIKPFTMVVLAQFFLGWLFQPILTGTEIIRGSEVTLANSYIAGAILLGIAPCTAMVMMWGYLSYSNQGHTLVMVAINSLAMLFLYAPLGGWLLSAN...n Leptolyngbya sp. PCC 7375 MTSDYSQAPPQAGGELNIFERYLTLWVAVCIVAGILLGRVFPSVAQTLDAMSVYQVSIPIAICLFCMMYPIMVKIDFSQA...LHILLIAVPLFLQTNFIFLITYVAAQKMGMVYEDAAPAALIGASNHFEVAIATAVTLFGLNSGAALATVVGVLIEVPVMLMLVALCKRTAFWFSREPHKATLPDPRCIRPLS ...

  10. Protein (Cyanobacteria): 161615 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available SQAVKAAKTPKPVLLTLVINWLIKPFTMIAFAQFFLGYLFLPFLSETEIILGQSVSIANSYIAGTILLGIAPCTAMVLMWGYLSYSNQGHTLIMVAINSLAMLFLYAPLGKWLLAAN...ein Cyanothece sp. PCC 8802 MSNSRPTLNPKAVKAGGSLNIFEKYLTLWVFICIVVGIILGRVFPDVAKTLDSFSLHQVSIPIAICLFFMMYPIMVKIDF...NNPLHIFFIAVPLFIQTNFIFLITYVVGLKLNLYYEDAAPAALIGASNHFEVAIATAVVLFGLNSGAALATVVGVLIEVPVMLMLVEFCKKTAFWFPREPEKATLLDPRCIKPFN ...

  11. Protein (Cyanobacteria): 460882 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available tein Oscillatoria sp. PCC 6506 MMAGSYSKINYRIRPAKAVERKIICDSLRCLSPFGELTTYRYVGFGSTYFSDFILFHKSLHIEDMISIEKDSQAKERFEYNKPFGCIEIKYGNSY...EVLPTLEWSKKSIVWLDYDSPLEKTILDDIDTLTTKLASGSVLIVTVSAEPEKPPEEGWNRAKIDKFREDKLQANIPKEKIPPDLEPINL...TGKKLADLYNRIINNQLKQSVSNANSARSEYQKLNYKQIFDFRYADGARMLTVGWLLFEQSYCNLVEQCKFNNNFNITELNKPYEIKVPNLTLKETQYLDSLMPTHDCNGVERICIPLKDIKLYAELYKYFPSFVEMFM ...

  12. Protein (Cyanobacteria): 104396 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available ein Arthrospira sp. PCC 8005 MDVNAIASHDSSIQRVSETSDSVDVNAIASDDSSIQRLPETSDSGDVNNAIASHDSPIQRLPETSDSSPIQRLPETSDSVDVNAIASDDSPSIQRVSETSDS...VEDISNAIAFHDSSIQRLPETSDSSPIQRLPETSDSVDVNAIASHDSSIQRVSETSDSVDVNAIASHDSPIQRLPETSDSSPIQRLPETSDS...VDVNAIASHDSSIQRVSETSDSVDVNAIASHDSPIQRLPETSDSGDVNNAIASHDSTIQRLSETSDSSPIPRLSETSDS...GDVNNAIASHDSTIQPQSETSNSGDITDGISDTNSLFFQPKSDINPGLSDSNKTVKEMLINGGIPEIQRFIKNINKPGFITKNNQKKYDKNKPLNKQKLMKNN

  13. Protein (Cyanobacteria): 24507 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available tical protein Cal6303_0287 Calothrix sp. PCC 6303 MATRKSSTTTFNAIDDSILGDYAVNNYSERVYSKVYYSIRELCGLVAKRSLKEAFDWNNFKERFTSDFGKVEENRYSLEQLLEYANRKFGKTLEDLIVQNQISWQRRQEYTERSNMSYQSKMIEDSTCY ...

  14. Protein (Cyanobacteria): 457348 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available pto7376_2753 Leptolyngbya sp. PCC 7376 MPNDSERRDDPQGYLDLIYLLINSKVKISSKKTSNLTWKITLNNPQINFNLTPFKITINIVQIALVSFFLGGFLAVVLNTNHSLLQQSESSES...SESSESSESSESSESSESSESSESSESSESSESSESSESSESSETRNPLVAHLTYFDSNTSIVFEACLFDDGFYQPEVAVAVCG

  15. Protein (Cyanobacteria): 239611 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available elta' Cyanothece sp. PCC 7424 MNDFTQLIGQGQAIELLQCAIASNRIAPAYLFVGAAGVGRGLAAKCFSCSLLSHHFPPQQQSLIRPKILAGNHPDLLW...VQPTYQHQGKFLTALEAEEAGLKRKSPPQIRIEQIRDITRFLSRPPLEALRTVVVIEDAQTMTESAANALLKTLEEPGRCTLILIAPSTDSLLPTLVSRCQRIPFSRLSDPDMEIILQNNDYENIL...KYPELLGIAQGSPGEAISAYTQLQNLPDELKGSLRQFPKNVMQGLELAKKLTQELDTQMQLWLVDYLQYFYWEQWKNKKLLDVLEKTRQCLLAYVQPRLVWEWTFLELSQFILN ...

  16. Protein (Cyanobacteria): 278248 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available ELDVYLHHQEGYRVPVSVRIAPITDEQGVIVGAVELFLENSSKLALLKELESIKGELFFDPLTHLGNRKLIRIELEHKFEHLYSYSIPFGILFIDLDDFKQINDNYGHNIGDKILI...MAAKTLSNILRNMDIVARWGGDEFLVIIPNIDSKHLKIIANRISSFIKESWLIINDKKVGITASIGGTMAKKEDTIESLIERADREMYKSKMLGRNRVSLSEDQI ... ...diguanylate cyclase Cyanothece sp. PCC 7822 MSPDFYEKLVDNLHDGVYYVDLKKNITYWNQAAERITGYTREQVLGSKCSDNILRHIDEQGRELCIIGCPLVQTLRDGKIR

  17. Protein (Cyanobacteria): 49109 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available IGLGNSSVAQLLSNEQFKLVPIDQIGALQLTQPYLESTIIPKGSYDGGAPIPSEDLPVVSVSALLIANVDAHPDVVKAITRIL...YEHRSELIRINPRTANIQSPENSQNLGFPLHEGARAYYTQDNPSFLVTYAESIGLLMSISILICSSLWQGRQWFISNQKDRADRYNLEILDLIEKIEQAQDFDELQNLRQQLLEILRKVVVDLDIDKISPESFQSFTFPWEVANTAIRHQEIILSGRSTREKKY ... ...ptor, TAXI family Leptolyngbya sp. PCC 7375 MGKWGRWGVGLVVVVSVGVAIASITKLIQEQNRIYIIRLATGSPTGEYYAFGQAIAQVTEANEPKIR...VEVVASPGSNQNMDDVHTHTVDLALVQNDTPTQRNVRAIAQLYPEMFHLIANKDANISNLTDLKGRRIALMPEGSGSYNLFWPLSQHYGLTKNDFQFQSMGVTEAHTALQNGTVDALFRI

  18. Protein (Cyanobacteria): 216780 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available AVGERSLDALLEDKGTIDRSIFEYIRQKTADYGIEVDSVGVKDIILPGEIKTILSKVVEAEKAAQANVVRRREETAATRSMLNTARVMEDNPVALRLKELEVLERIAEKIEKIQVNGSLDSILTELIRINPN ... ...ALVRCGQTWLSVLPNQLRVFWRGFIEVQAHFFNLETNLELPAEFVQQLRGIILSGIKKFPVSEYELGLLYVQNNFVRSLSTGEYAFWSVDRDVSVRTISRLIPNPDFPLEEILI...EQHPDFVATYCETVQLQSQQVAIARYQGKVIAILPPTTRKLFWQGVEVEVIDISTDAKLPTSLIAELVSGSREVV... alr0740 Nostoc sp. PCC 7120 MWKTFYIKPNEIGILYHRSDFKKILQPGTYIYFGRHWQVKTYDLNQPEAKIENLELLLRNHSAELQEHLLIVRTAFNQA...ALSHNYLHLCEVPPQHIGLLYINQEFQAQLPSGKHAWWLFGRSWQTEVFDLRQQTLEVSGQDILSKDKVPLRLNLTAGYRLLDPLRARNGLSDILNYLYKELQFALRG

  19. Protein (Cyanobacteria): 274866 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 9860 Lyngbya sp. PCC 8106 MTSSDSVESWDFDRARRSLRQAMIRYSHKRRQRQNPPELQATLKTQLDILAESLDKLDQGLIRIAVFGLVSRGKSAVLNALLGEHIL...HLEGRSLLALNALVQAREAEKQIAHQTIKLQQTEAEALIWQFTKYKAIAIAINPIAIIDVLATTISDLILIRSLARLYGLPITNYEASQLLRTILLSAGGMILAEWGSGAIL...QTGPLNGVTQWPRSVRWTVPSRYDHQQDSIPVELIDTPGLDEVGGQVRGEMAREVTRQADLILFVVSGDLTRTEYEGLCELRRSTKPLIVVFNKVDLYTDTEQ...QAIYFNLQRLTTPDALNFDFDDLNWDAPTEPLKVGETAKTDSSLLEVVRVAAEPATVQVRVEWPDGRVTSEWESPPPQIDELKSAIVNIL

  20. Protein (Cyanobacteria): 319718 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available YTDPLKVKFPDGYQTAVYRFDTPDQMTLPQTTGAKTVAARIAFDDIFSTQLLRVLIRSGIWRLISGDRFTSLRRSLLYNPGSGASHQIRI...Leptolyngbya sp. PCC 7376 MDIRNSILIAGGYGVVGRQIATLIRDHHPDLPLVIAGRNLKKAEALAQELGNASGLQLDVEQPKPLQENTPRAVIAVVNDSY...DVKGKDAQDLPQKVTATIVDPKGQTHLTALGALIQLERLLGLDGMKPPIPGIIYPDTAPQIKNALQILQEFGVIVTGISEKMFEKIPMTLQEKLPLKILSLSH ... ...DYLLMDAVSKEIPYLDVTRWPERLRQSIDALDEQSLRSPVMFASGWMGGVASVIAVAASQAIATIDSIDISVLFSLKDKAGPNSVEYMDRLATPFETMIAGRTTKVFP