Mutation of the murC and murB Genes Impairs Heterocyst Differentiation in Anabaena sp. Strain PCC 7120.

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Videau, Patrick; Rivers, Orion S; Ushijima, Blake; Oshiro, Reid T; Kim, Min Joo; Philmus, Benjamin; Cozy, Loralyn M

2016-04-01

To stabilize cellular integrity in the face of environmental perturbations, most bacteria, including cyanobacteria, synthesize and maintain a strong, flexible, three-dimensional peptidoglycan lattice. Anabaena sp. strain PCC 7120 is a filamentous cyanobacterium capable of differentiating morphologically distinct nitrogen-fixing heterocyst cells in a periodic pattern. While heterocyst development has been shown to require proper peptidoglycan remodeling, the role of peptidoglycan synthesis has remained unclear. Here we report the identification of two peptidoglycan synthesis genes, murC (alr5065) and murB (alr5066), as required for heterocyst development. The murC and murB genes are predicted to encode a UDP-N-acetylmuramate:L-alanine ligase and a UDP-N-acetylenolpyruvoylglucosamine reductase, respectively, and we confirm enzymatic function through complementation of Escherichia coli strains deficient for these enzymes. Cells depleted of either murC or murB expression failed to differentiate heterocysts under normally inducing conditions and displayed decreased filament integrity. To identify the stage(s) of development affected by murC or murB depletion, the spatial distribution of expression of the patterning marker gene, patS, was examined. Whereas murB depletion did not affect the pattern of patS expression, murC depletion led to aberrant expression of patS in all cells of the filament. Finally, expression of gfp controlled by the region of DNA immediately upstream of murC was enriched in differentiating cells and was repressed by the transcription factor NtcA. Collectively, the data in this work provide evidence for a direct link between peptidoglycan synthesis and the maintenance of a biological pattern in a multicellular organism. Multicellular organisms that differentiate specialized cells must regulate morphological changes such that both cellular integrity and the dissemination of developmental signals are preserved. Here we show that the multicellular

Structural and functional analysis of the finished genome of the recently isolated toxic Anabaena sp. WA102.

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Brown, Nathan M; Mueller, Ryan S; Shepardson, Jonathan W; Landry, Zachary C; Morré, Jeffrey T; Maier, Claudia S; Hardy, F Joan; Dreher, Theo W

2016-06-13

Very few closed genomes of the cyanobacteria that commonly produce toxic blooms in lakes and reservoirs are available, limiting our understanding of the properties of these organisms. A new anatoxin-a-producing member of the Nostocaceae, Anabaena sp. WA102, was isolated from a freshwater lake in Washington State, USA, in 2013 and maintained in non-axenic culture. The Anabaena sp. WA102 5.7 Mbp genome assembly has been closed with long-read, single-molecule sequencing and separately a draft genome assembly has been produced with short-read sequencing technology. The closed and draft genome assemblies are compared, showing a correlation between long repeats in the genome and the many gaps in the short-read assembly. Anabaena sp. WA102 encodes anatoxin-a biosynthetic genes, as does its close relative Anabaena sp. AL93 (also introduced in this study). These strains are distinguished by differences in the genes for light-harvesting phycobilins, with Anabaena sp. AL93 possessing a phycoerythrocyanin operon. Biologically relevant structural variants in the Anabaena sp. WA102 genome were detected only by long-read sequencing: a tandem triplication of the anaBCD promoter region in the anatoxin-a synthase gene cluster (not triplicated in Anabaena sp. AL93) and a 5-kbp deletion variant present in two-thirds of the population. The genome has a large number of mobile elements (160). Strikingly, there was no synteny with the genome of its nearest fully assembled relative, Anabaena sp. 90. Structural and functional genome analyses indicate that Anabaena sp. WA102 has a flexible genome. Genome closure, which can be readily achieved with long-read sequencing, reveals large scale (e.g., gene order) and local structural features that should be considered in understanding genome evolution and function.

Characterization and Optimization of Bioflocculant Exopolysaccharide Production by Cyanobacteria Nostoc sp. BTA97 and Anabaena sp. BTA990 in Culture Conditions.

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Tiwari, Onkar Nath; Khangembam, Romi; Shamjetshabam, Minerva; Sharma, Aribam Subhalaxmi; Oinam, Gunapati; Brand, Jerry J

2015-08-01

Bioflocculant exopolysaccharide (EPS) production by 40 cyanobacterial strains during their photoautotrophic growth was investigated. Highest levels of EPS were produced by Nostoc sp. BTA97 and Anabaena sp. BTA990. EPS production was maximum during stationary growth phase, when nitrogenase activity was very low. Maximum EPS production occurred at pH 8.0 in the absence of any combined nitrogen source. The cyanobacterial EPS consisted of soluble protein and polysaccharide that included substantial amounts of neutral sugars and uronic acid. The EPS isolated from Anabaena sp. BTA990 and Nostoc sp. BTA97 demonstrated high flocculation capacity. There was a positive correlation between uronic acid content and flocculation activity. The flocculant bound a cationic dye, Alcian Blue, indicating it to be polyanionic. The 16S rRNA gene sequences for Nostoc sp. BTA97 and Anabaena sp. BTA990 were deposited at NCBI GenBank, and accession numbers were obtained as KJ830951 and KJ830948, respectively. The results of these experiments indicate that strains Anabaena sp. BTA990 and Nostoc sp. BTA97 are good candidates for the commercial production of EPS and might be utilized in industrial applications as an alternative to synthetic and abiotic flocculants.

Utilization of the cyanobacteria Anabaena sp CH1 in biological carbon dioxide mitigation processes

Energy Technology Data Exchange (ETDEWEB)

Chiang, C.L.; Lee, C.M.; Chen, P.C. [Hungkuang University, Taichung (Taiwan)

2011-05-15

Before switching totally to alternative fuel stage, CO{sub 2} mitigation process has considered a transitional strategy for combustion of fossil fuels inevitably. In comparison to other CO{sub 2} mitigation options, such as oceanic or geologic injection, the biological photosynthetic process would present a far superior and sustainable solution under both environmental and social considerations. The utilization of the cyanobacteria Anabaena sp. CH1 in carbon dioxide mitigation processes is analyzed in our research. It was found that an original developed photobioreactor with internal light source exhibits high light utilization. Anabaena sp. CH1 demonstrates excellent CO{sub 2} tolerance even at 15% CO{sub 2} level. This enables flue gas from power plant to be directly introduced to Anabaena sp. CH1 culture. Double light intensity and increased 47% CO{sub 2} bubble retention time could enhance CO{sub 2} removal efficiencies by 79% and 67%, respectively. A maximum CO{sub 2} fixation rate of 1.01 g CO{sub 2} L{sup -1} day{sup -1} was measured experimentally.

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

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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.

Improved Alkane Production in Nitrogen-Fixing and Halotolerant Cyanobacteria via Abiotic Stresses and Genetic Manipulation of Alkane Synthetic Genes.

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Kageyama, Hakuto; Waditee-Sirisattha, Rungaroon; Sirisattha, Sophon; Tanaka, Yoshito; Mahakhant, Aparat; Takabe, Teruhiro

2015-07-01

Cyanobacteria possess the unique capacity to produce alkane. In this study, effects of nitrogen deficiency and salt stress on biosynthesis of alkanes were investigated in three kinds of cyanobacteria. Intracellular alkane accumulation was increased in nitrogen-fixing cyanobacterium Anabaena sp. PCC7120, but decreased in non-diazotrophic cyanobacterium Synechococcus elongatus PCC7942 and constant in a halotolerant cyanobacterium Aphanothece halophytica under nitrogen-deficient condition. We also found that salt stress increased alkane accumulation in Anabaena sp. PCC7120 and A. halophytica. The expression levels of two alkane synthetic genes were not upregulated significantly under nitrogen deficiency or salt stress in Anabaena sp. PCC7120. The transformant Anabaena sp. PCC7120 cells with additional alkane synthetic gene set from A. halophytica increased intracellular alkane accumulation level compared to control cells. These results provide a prospect to improve bioproduction of alkanes in nitrogen-fixing halotolerant cyanobacteria via abiotic stresses and genetic engineering.

Induction of the Nitrate Assimilation nirA Operon and Protein-Protein Interactions in the Maturation of Nitrate and Nitrite Reductases in the Cyanobacterium Anabaena sp. Strain PCC 7120.

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Frías, José E; Flores, Enrique

2015-07-01

Nitrate is widely used as a nitrogen source by cyanobacteria, in which the nitrate assimilation structural genes frequently constitute the so-called nirA operon. This operon contains the genes encoding nitrite reductase (nirA), a nitrate/nitrite transporter (frequently an ABC-type transporter; nrtABCD), and nitrate reductase (narB). In the model filamentous cyanobacterium Anabaena sp. strain PCC 7120, which can fix N2 in specialized cells termed heterocysts, the nirA operon is expressed at high levels only in media containing nitrate or nitrite and lacking ammonium, a preferred nitrogen source. Here we examined the genes downstream of the nirA operon in Anabaena and found that a small open reading frame of unknown function, alr0613, can be cotranscribed with the operon. The next gene in the genome, alr0614 (narM), showed an expression pattern similar to that of the nirA operon, implying correlated expression of narM and the operon. A mutant of narM with an insertion mutation failed to produce nitrate reductase activity, consistent with the idea that NarM is required for the maturation of NarB. Both narM and narB mutants were impaired in the nitrate-dependent induction of the nirA operon, suggesting that nitrite is an inducer of the operon in Anabaena. It has previously been shown that the nitrite reductase protein NirA requires NirB, a protein likely involved in protein-protein interactions, to attain maximum activity. Bacterial two-hybrid analysis confirmed possible NirA-NirB and NarB-NarM interactions, suggesting that the development of both nitrite reductase and nitrate reductase activities in cyanobacteria involves physical interaction of the corresponding enzymes with their cognate partners, NirB and NarM, respectively. Nitrate is an important source of nitrogen for many microorganisms that is utilized through the nitrate assimilation system, which includes nitrate/nitrite membrane transporters and the nitrate and nitrite reductases. Many cyanobacteria

Retinal is formed from apo-carotenoids in Nostoc sp. PCC7120: in vitro characterization of an apo-carotenoid oxygenase

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Scherzinger, Daniel; Ruch, Sandra; Kloer, Daniel P.; Wilde, Annegret; Al-Babili, Salim

2006-01-01

The sensory rhodopsin from Anabaena (Nostoc) sp. PCC7120 is the first cyanobacterial retinylidene protein identified. Here, we report on NosACO (Nostoc apo-carotenoid oxygenase), encoded by the ORF (open reading frame) all4284, as the candidate responsible for the formation of the required chromophore, retinal. In contrast with the enzymes from animals, NosACO converts β-apo-carotenals instead of β-carotene into retinal in vitro. The identity of the enzymatic products was proven by HPLC and gas chromatography–MS. NosACO exhibits a wide substrate specificity with respect to chain lengths and functional end-groups, converting β-apo-carotenals, (3R)-3-hydroxy-β-apo-carotenals and the corresponding alcohols into retinal and (3R)-3-hydroxyretinal respectively. However, kinetic analyses revealed very divergent Km and Vmax values. On the basis of the crystal structure of SynACO (Synechocystis sp. PCC6803 apo-carotenoid oxygenase), a related enzyme showing similar enzymatic activity, we designed a homology model of the native NosACO. The deduced structure explains the absence of β-carotene-cleavage activity and indicates that NosACO is a monotopic membrane protein. Accordingly, NosACO could be readily reconstituted into liposomes. To localize SynACO in vivo, a Synechocystis knock-out strain was generated expressing SynACO as the sole carotenoid oxygenase. Western-blot analyses showed that the main portion of SynACO occurred in a membrane-bound form. PMID:16759173

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

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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 restriction endonucleases. Eight DNA probes were selected to identify the Anabaena strains tested. Two were strain specific and hybridized only to A. azollae strains isolated from Azolla microphylla or Azolla caroliniana. One DNA probe was section specific (hybridized only to anabaenas isolated from Azolla ferns representing the section Euazolla), and five other probes gave finer discrimination among anabaenas representing various ecotypes of Azolla species. These cloned genomic DNA probes identified 11 different genotypes of A. azollae isolates. These included three endosymbiotic genotypes within Azolla filiculoides species and two genotypes within both A. caroliniana and Azolla pinnata endosymbionts. Although we were not able to discriminate among anabaenas extracted from different ecotypes of Azolla nilotica, Azolla mexicina, Azolla rubra and Azolla microphylla species, each of the endosymbionts was easily identified as a unique genotype. When total DNA isolated from free-living Anabaena sp. strain PCC7120 was screened, none of the genomic DNA probes gave detectable positive hybridization. Total DNA of Nostoc cycas PCC7422 hybridized with six of eight genomic DNA fragments. These data imply that the dominant symbiotic organism in association with Azolla spp. is more closely related to Nostoc spp. than to free-living Anabaena spp. Images PMID:16348182

Glycogen production for biofuels by the euryhaline cyanobacteria Synechococcus sp. strain PCC 7002 from an oceanic environment.

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Aikawa, Shimpei; Nishida, Atsumi; Ho, Shih-Hsin; Chang, Jo-Shu; Hasunuma, Tomohisa; Kondo, Akihiko

2014-01-01

Oxygenic photosynthetic microorganisms such as cyanobacteria and microalgae have attracted attention as an alternative carbon source for the next generation of biofuels. Glycogen abundantly accumulated in cyanobacteria is a promising feedstock which can be converted to ethanol through saccharification and fermentation processes. In addition, the utilization of marine cyanobacteria as a glycogen producer can eliminate the need for a freshwater supply. Synechococcus sp. strain PCC 7002 is a fast-growing marine coastal euryhaline cyanobacteria, however, the glycogen yield has not yet been determined. In the present study, the effects of light intensity, CO2 concentration, and salinity on the cell growth and glycogen content were investigated in order to maximize glycogen production in Synechococcus sp. strain PCC 7002. The optimal culture conditions for glycogen production in Synechococcus sp. strain PCC 7002 were investigated. The maximum glycogen production of 3.5 g L(-1) for 7 days (a glycogen productivity of 0.5 g L(-1) d(-1)) was obtained under a high light intensity, a high CO2 level, and a nitrogen-depleted condition in brackish water. The glycogen production performance in Synechococcus sp. strain PCC 7002 was the best ever reported in the α-polyglucan (glycogen or starch) production of cyanobacteria and microalgae. In addition, the robustness of glycogen production in Synechococcus sp. strain PCC 7002 to salinity was evaluated in seawater and freshwater. The peak of glycogen production of Synechococcus sp. strain PCC 7002 in seawater and freshwater were 3.0 and 1.8 g L(-1) in 7 days, respectively. Glycogen production in Synechococcus sp. strain PCC 7002 maintained the same level in seawater and half of the level in freshwater compared with the optimal result obtained in brackish water. We conclude that Synechococcus sp. strain PCC 7002 has high glycogen production activity and glycogen can be provided from coastal water accompanied by a fluctuation

NADPH-thioredoxin reductase C mediates the response to oxidative stress and thermotolerance in the cyanobacterium Anabaena sp. PCC7120.

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ANA MARÍA SÁNCHEZ-RIEGO

2016-08-01

Full Text Available NTRC (NADPH-thioredoxin reductase C is a bimodular enzyme composed of an NADPH-thioredoxin reductase and a thioredoxin domain extension in the same protein. In plants, NTRC has been described to be involved in the protection of the chloroplast against oxidative stress damage through reduction of the 2-Cys peroxiredoxin (2-Cys Prx as well as through other functions related to redox enzyme regulation. In cyanobacteria, the Anabaena NTRC has been characterized in vitro, however nothing was known about its in vivo function. In order to study that, we have generated the first knockout mutant strain (∆ntrC, apart from the previously described in Arabidopsis. Detailed characterization of this strain reveals a differential sensitivity to oxidative stress treatments with respect to the wild-type Anabaena strain, including a higher level of ROS (reactive oxygen species in normal growth conditions. In the mutant strain, different oxidative stress treatments such as hydrogen peroxide, methyl-viologen or high light irradiance provoke an increase in the expression of genes related to ROS detoxification, including AnNTRC and peroxiredoxin genes, with a concomitant increase in the amount of AnNTRC and 2-Cys Prx. Moreover, the role of AnNTRC in the antioxidant response is confirmed by the observation of a pronounced overoxidation of the 2-Cys Prx and a time-delay recovery of the reduced form of this protein upon oxidative stress treatments. Our results suggest the participation of this enzyme in the peroxide detoxification in Anabaena. In addition, we describe the role of Anabaena NTRC in thermotolerance, by the appearance of high molecular mass AnNTRC complexes, showing that the mutant strain is more sensitive to high temperature treatments.

Deep sequencing-based identification of small regulatory RNAs in Synechocystis sp. PCC 6803.

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Wen Xu

Full Text Available Synechocystis sp. PCC 6803 is a genetically tractable model organism for photosynthesis research. The genome of Synechocystis sp. PCC 6803 consists of a circular chromosome and seven plasmids. The importance of small regulatory RNAs (sRNAs as mediators of a number of cellular processes in bacteria has begun to be recognized. However, little is known regarding sRNAs in Synechocystis sp. PCC 6803. To provide a comprehensive overview of sRNAs in this model organism, the sRNAs of Synechocystis sp. PCC 6803 were analyzed using deep sequencing, and 7,951,189 reads were obtained. High quality mapping reads (6,127,890 were mapped onto the genome and assembled into 16,192 transcribed regions (clusters based on read overlap. A total number of 5211 putative sRNAs were revealed from the genome and the 4 megaplasmids, and 27 of these molecules, including four from plasmids, were confirmed by RT-PCR. In addition, possible target genes regulated by all of the putative sRNAs identified in this study were predicted by IntaRNA and analyzed for functional categorization and biological pathways, which provided evidence that sRNAs are indeed involved in many different metabolic pathways, including basic metabolic pathways, such as glycolysis/gluconeogenesis, the citrate cycle, fatty acid metabolism and adaptations to environmentally stress-induced changes. The information from this study provides a valuable reservoir for understanding the sRNA-mediated regulation of the complex physiology and metabolic processes of cyanobacteria.

Regulation of Development and Nitrogen Fixation in Anabaena

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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

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

Czech Academy of Sciences Publication Activity Database

Zavřel, Tomáš; Očenášová, Petra; Červený, Jan

2017-01-01

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

CyanOmics: an integrated database of omics for the model cyanobacterium Synechococcus sp. PCC 7002

OpenAIRE

Yang, Yaohua; Feng, Jie; Li, Tao; Ge, Feng; Zhao, Jindong

2015-01-01

Cyanobacteria are an important group of organisms that carry out oxygenic photosynthesis and play vital roles in both the carbon and nitrogen cycles of the Earth. The annotated genome of Synechococcus sp. PCC 7002, as an ideal model cyanobacterium, is available. A series of transcriptomic and proteomic studies of Synechococcus sp. PCC 7002 cells grown under different conditions have been reported. However, no database of such integrated omics studies has been constructed. Here we present Cyan...

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.

Protein (Cyanobacteria): 515516403 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available hypothetical protein Anabaena sp. PCC 7108 MTVRFLLDSNIISEPSRPIPNIQVLDQLNRYRSEVAIASVVVHEILYGCWRLPPSKRKDSLWKYIQDSVLNLPVFDYNLNAAKWHAQERARLSKIGKTPAFIDGQIASIAFCNDLILVTNNVADFQDFQDLVIENWFI

CyanOmics: an integrated database of omics for the model cyanobacterium Synechococcus sp. PCC 7002.

Science.gov (United States)

Yang, Yaohua; Feng, Jie; Li, Tao; Ge, Feng; Zhao, Jindong

2015-01-01

Cyanobacteria are an important group of organisms that carry out oxygenic photosynthesis and play vital roles in both the carbon and nitrogen cycles of the Earth. The annotated genome of Synechococcus sp. PCC 7002, as an ideal model cyanobacterium, is available. A series of transcriptomic and proteomic studies of Synechococcus sp. PCC 7002 cells grown under different conditions have been reported. However, no database of such integrated omics studies has been constructed. Here we present CyanOmics, a database based on the results of Synechococcus sp. PCC 7002 omics studies. CyanOmics comprises one genomic dataset, 29 transcriptomic datasets and one proteomic dataset and should prove useful for systematic and comprehensive analysis of all those data. Powerful browsing and searching tools are integrated to help users directly access information of interest with enhanced visualization of the analytical results. Furthermore, Blast is included for sequence-based similarity searching and Cluster 3.0, as well as the R hclust function is provided for cluster analyses, to increase CyanOmics's usefulness. To the best of our knowledge, it is the first integrated omics analysis database for cyanobacteria. This database should further understanding of the transcriptional patterns, and proteomic profiling of Synechococcus sp. PCC 7002 and other cyanobacteria. Additionally, the entire database framework is applicable to any sequenced prokaryotic genome and could be applied to other integrated omics analysis projects. Database URL: http://lag.ihb.ac.cn/cyanomics. © The Author(s) 2015. Published by Oxford University Press.

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

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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.

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

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Badri, Hanène; Leys, Natalie; Wattiez, Ruddy

Arthrospira (Spirulina) is a photosynthetic cyanobacterium able to use sunlight to release oxygen from water and remove carbon dioxide and nitrate from water. In addition, it is suited for human consumption (edible). For these traits, the cyanobacterium Arthrospira sp. PCC 8005 was selected by the European Space Agency (ESA) as part of the life support system MELiSSA for recycling oxygen, water, and food during future long-haul space missions. However, during such extended missions, Arthrospira sp. PCC 8005 will be exposed to continuous artificial illumination and harmful cosmic radiation. The aim of this study was to investigate how Arthrospira will react and behave when exposed to such stress environment. The cyanobacterium Arthrospira sp. PCC 8005 was exposed to high gamma rays doses in order to unravel in details the response of this bacterium following such stress. Test results showed that after acute exposure to high doses of 60Co gamma radiation upto 3200 Gy, Arthrospira filaments were still able to restart photosynthesis and proliferate normally. Doses above 3200 Gy, did have a detrimental effect on the cells, and delayed post-irradiation proliferation. The photosystem activity, measured as the PSII quantum yield immediately after irradiation, decreased significantly at radiation doses above 3200 Gy. Likewise through pigment content analysis a significant decrease in phycocyanin was observed following exposure to 3200 Gy. The high tolerance of this bacterium to 60Co gamma rays (i.e. ca. 1000x more resistant than human cells for example) raised our interest to investigate in details the cellular and molecular mechanisms behind this amazing resistance. Optimised DNA, RNA and protein extraction methods and a new microarray chip specific for Arthrospira sp. PCC 8005 were developed to identify the global cellular and molecular response following exposure to 3200 Gy and 5000 Gy A total of 15,29 % and 30,18 % genes were found differentially expressed in RNA

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

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

2017-03-01

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

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

Growth of Chlamydomonas reinhardtii in acetate-free medium when co-cultured with alginate-encapsulated, acetate-producing strains of Synechococcus sp. PCC 7002.

Science.gov (United States)

Therien, Jesse B; Zadvornyy, Oleg A; Posewitz, Matthew C; Bryant, Donald A; Peters, John W

2014-01-01

The model alga Chlamydomonas reinhardtii requires acetate as a co-substrate for optimal production of lipids, and the addition of acetate to culture media has practical and economic implications for algal biofuel production. Here we demonstrate the growth of C. reinhardtii on acetate provided by mutant strains of the cyanobacterium Synechococcus sp. PCC 7002. Optimal growth conditions for co-cultivation of C. reinhardtii with wild-type and mutant strains of Synechococcus sp. 7002 were established. In co-culture, acetate produced by a glycogen synthase knockout mutant of Synechococcus sp. PCC 7002 was able to support the growth of a lipid-accumulating mutant strain of C. reinhardtii defective in starch production. Encapsulation of Synechococcus sp. PCC 7002 using an alginate matrix was successfully employed in co-cultures to limit growth and maintain the stability. The ability of immobilized strains of the cyanobacterium Synechococcus sp. PCC 7002 to produce acetate at a level adequate to support the growth of lipid-accumulating strains of C. reinhartdii offers a potentially practical, photosynthetic alternative to providing exogenous acetate into growth media.

The heterocyst differentiation transcriptional regulator HetR of the filamentous cyanobacterium Anabaena forms tetramers and can be regulated by phosphorylation.

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Valladares, Ana; Flores, Enrique; Herrero, Antonia

2016-02-01

Many filamentous cyanobacteria respond to the external cue of nitrogen scarcity by the differentiation of heterocysts, cells specialized in the fixation of atmospheric nitrogen in oxic environments. Heterocysts follow a spatial pattern along the filament of two heterocysts separated by ca. 10-15 vegetative cells performing oxygenic photosynthesis. HetR is a transcriptional regulator that directs heterocyst differentiation. In the model strain Anabaena sp. PCC 7120, the HetR protein was observed in various oligomeric forms in vivo, including a tetramer that peaked with maximal hetR expression during differentiation. Tetramers were not detected in a hetR point mutant incapable of differentiation, but were conspicuous in an over-differentiating strain lacking the PatS inhibitor. In differentiated filaments the HetR tetramer was restricted to heterocysts, being undetectable in vegetative cells. HetR co-purified with RNA polymerase from Anabaena mainly as a tetramer. In vitro, purified recombinant HetR was distributed between monomers, dimers, trimers and tetramers, and it was phosphorylated when incubated with (γ-(32)P)ATP. Phosphorylation and PatS hampered the accumulation of HetR tetramers and impaired HetR binding to DNA. In summary, tetrameric HetR appears to represent a functionally relevant form of HetR, whose abundance in the Anabaena filament could be negatively regulated by phosphorylation and by PatS. © 2015 John Wiley & Sons Ltd.

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

International Nuclear Information System (INIS)

Chen, C.H.; Van Baalen, C.; Tabita, F.R.

1987-01-01

An alternative route for the primary assimilation of ammonia proceeds via glutamine synthetase-carbamyl phosphate synthetase and its inherent glutaminase activity in Anabaena sp. strain 1F, a marine filamentous, heterocystous cyanobacterium. Evidence for the presence of this possible alternative route to glutamate was provided by the use of amino acid analogs as specific enzyme inhibitors, enzymological studies, and radioistopic labeling experiments. The amino acid pool patterns of continuous cultures of Anabaena sp. strain 1F were markedly influenced by the nitrogen source. A relatively high concentration of glutamate was maintained in the amino acid pools of all cultures irrespective of the nitrogen source, reflecting the central role of glutamate in nitrogen metabolism. The addition of 1.0 microM azaserine increased the intracellular pools of glutamate and glutamine. All attempts to detect any enzymatic activity for glutamate synthase by measuring the formation of L-[ 14 C]glutamate from 2-keto-[1- 14 C]glutarate and glutamine failed. The addition of 10 microM DL-7-azatryptophan caused a transient accumulation of intracellular citrulline and alanine which was not affected by the presence of chloramphenicol. The in vitro activity of carbamyl phosphate synthetase and glutaminase increased severalfold in the presence of azatryptophan. Results from radioisotopic labeling experiments with [ 14 C]bicarbonate and L-[1- 14 C]ornithine also indicated that citrulline was formed via carbamyl phosphate synthetase and ornithine transcarbamylase. In addition to its effects on nitrogen metabolism, azatryptophan also affected carbon metabolism by inhibiting photosynthetic carbon assimilation and photosynthetic oxygen evolution

Variety of DNA Replication Activity Among Cyanobacteria Correlates with Distinct Respiration Activity in the Dark.

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Ohbayashi, Ryudo; Yamamoto, Jun-Ya; Watanabe, Satoru; Kanesaki, Yu; Chibazakura, Taku; Miyagishima, Shin-Ya; Yoshikawa, Hirofumi

2017-02-01

Cyanobacteria exhibit light-dependent cell growth since most of their cellular energy is obtained by photosynthesis. In Synechococcus elongatus PCC 7942, one of the model cyanobacteria, DNA replication depends on photosynthetic electron transport. However, the critical signal for the regulatory mechanism of DNA replication has not been identified. In addition, conservation of this regulatory mechanism has not been investigated among cyanobacteria. To understand this regulatory signal and its dependence on light, we examined the regulation of DNA replication under both light and dark conditions among three model cyanobacteria, S. elongatus PCC 7942, Synechocystis sp. PCC 6803 and Anabaena sp. PCC 7120. Interestingly, DNA replication activity in Synechocystis and Anabaena was retained when cells were transferred to the dark, although it was drastically decreased in S. elongatus. Glycogen metabolism and respiration were higher in Synechocystis and Anabaena than in S. elongatus in the dark. Moreover, DNA replication activity in Synechocystis and Anabaena was reduced to the same level as that in S. elongatus by inhibition of respiratory electron transport after transfer to the dark. These results demonstrate that there is disparity in DNA replication occurring in the dark among cyanobacteria, which is caused by the difference in activity of respiratory electron transport. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

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)

Narayan, Om Prakash; Kumari, Nidhi; Rai, Lal Chand

2010-01-01

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 ), CuCl 2 (1 mM), UV-B (10 min), heat (47 o C), NaCl (6% w/v) and CdCl 2 (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.

Enzyme kinetics, inhibitors, mutagenesis and electron paramagnetic resonance analysis of dual-affinity nitrate reductase in unicellular N(2)-fixing cyanobacterium Cyanothece sp. PCC 8801.

Science.gov (United States)

Wang, Tung-Hei; Chen, Yung-Han; Huang, Jine-Yung; Liu, Kang-Cheng; Ke, Shyue-Chu; Chu, Hsiu-An

2011-11-01

The assimilatory nitrate reductase (NarB) of N(2)-fixing cyanobacterium Cyanothece sp. PCC 8801 is a monomeric enzyme with dual affinity for substrate nitrate. We purified the recombinant NarB of Cyanothece sp. PCC 8801 and further investigated it by enzyme kinetics analysis, site-directed mutagenesis, inhibitor kinetics analysis, and electron paramagnetic resonance (EPR) spectroscopy. The NarB showed 2 kinetic regimes at pH 10.5 or 8 and electron-donor conditions methyl viologen or ferredoxin (Fd). Fd-dependent NR assay revealed NarB with very high affinity for nitrate (K(m)1, ∼1μM; K(m)2, ∼270μM). Metal analysis and EPR results showed that NarB contains a Mo cofactor and a [4Fe-4S] cluster. In addition, the R352A mutation on the proposed nitrate-binding site of NarB greatly altered both high- and low-affinity kinetic components. Furthermore, the effect of azide on the NarB of Cyanothece sp. PCC 8801 was more complex than that on the NarB of Synechococcus sp. PCC 7942 with its single kinetic regime. With 1mM azide, the kinetics of the wild-type NarB was transformed from 2 kinetic regimes to hyperbolic kinetics, and its activity was enhanced significantly under medium nitrate concentrations. Moreover, EPR results also suggested a structural difference between the two NarBs. Taken together, our results show that the NarB of Cyanothece sp. PCC 8801 contains only a single Mo-catalytic center, and we rule out that the enzyme has 2 independent, distinct catalytic sites. In addition, the NarB of Cyanothece sp. PCC 8801 may have a regulatory nitrate-binding site. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

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

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Agervald, Åsa; Stensjö, Karin; Holmqvist, Marie; Lindblad, Peter

2008-01-01

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 assembly of the small subunit of

Construction of new synthetic biology tools for the control of gene expression in the cyanobacterium Synechococcus sp. strain PCC 7002.

Science.gov (United States)

Zess, Erin K; Begemann, Matthew B; Pfleger, Brian F

2016-02-01

Predictive control of gene expression is an essential tool for developing synthetic biological systems. The current toolbox for controlling gene expression in cyanobacteria is a barrier to more in-depth genetic analysis and manipulation. Towards relieving this bottleneck, this work describes the use of synthetic biology to construct an anhydrotetracycline-based induction system and adapt a trans-acting small RNA (sRNA) system for use in the cyanobacterium Synechococcus sp. strain PCC 7002. An anhydrotetracycline-inducible promoter was developed to maximize intrinsic strength and dynamic range. The resulting construct, PEZtet , exhibited tight repression and a maximum 32-fold induction upon addition of anhydrotetracycline. Additionally, a sRNA system based on the Escherichia coli IS10 RNA-IN/OUT regulator was adapted for use in Synechococcus sp. strain PCC 7002. This system exhibited 70% attenuation of target gene expression, providing a demonstration of the use of sRNAs for differential gene expression in cyanobacteria. These systems were combined to produce an inducible sRNA system, which demonstrated 59% attenuation of target gene expression. Lastly, the role of Hfq, a critical component of sRNA systems in E. coli, was investigated. Genetic studies showed that the Hfq homolog in Synechococcus sp. strain PCC 7002 did not impact repression by the engineered sRNA system. In summary, this work describes new synthetic biology tools that can be applied to physiological studies, metabolic engineering, or sRNA platforms in Synechococcus sp. strain PCC 7002. © 2015 Wiley Periodicals, Inc.

Effects of lindane on the photosynthetic apparatus of the cyanobacterium Anabaena: fluorescence induction studies and immunolocalization of ferredoxin-NADP+ reductase.

Science.gov (United States)

Bueno, Marta; Fillat, Maria F; Strasser, Reto J; Maldonado-Rodriguez, Ronald; Marina, Nerea; Smienk, Henry; Gómez-Moreno, Carlos; Barja, Francisco

2004-01-01

Cyanobacteria have the natural ability to degrade moderate amounts of organic pollutants. However, when pollutant concentration exceeds the level of tolerance, bleaching of the cells and death occur within 24 hours. Under stress conditions, cyanobacterial response includes the short-term adaptation of the photosynthetic apparatus to light quality, named state transitions. Moreover, prolonged stresses produce changes in the functional organization of phycobilisomes and in the core-complexes of both photosystems, which can result in large changes in the PS II fluorescence yield. The localization of ferredoxin-NADP+ reductase (FNR) at the ends of some peripheral rods of the cyanobacterial phycobilisomes, makes this protein a useful marker to check phycobilisome integrity. The goal of this work is to improve the knowledge of the mechanism of action of a very potent pesticide, lindane (gamma-hexaclorociclohexane), in the cyanobacterium Anabaena sp., which can be considered a potential candidate for bioremediation of pesticides. We have studied the effect of lindane on the photosynthetic apparatus of Anabaena using fluorescence induction studies. As ferredoxin-NADP+ reductase plays a key role in the response to oxidative stress in several systems, changes in synthesis, degradation and activity of FNR were analyzed. Immunolocalization of this enzyme was used as a marker of phycobilisome integrity. The knowledge of the changes caused by lindane in the photosynthetic apparatus is essential for rational further design of genetically-modified cyanobacteria with improved biorremediation abilities. Polyphasic chlorophyll a fluorescence rise measurements (OJIP) have been used to evaluate the vitality and stress adaptation of the nitrogen-fixing cyanobacterium Anabaena PCC 7119 in the presence of increasing concentrations of lindane. Effects of the pesticide on the ultrastructure have been investigated by electron microscopy, and FNR has been used as a marker of phycobilisome

Expression of organophosphorus-degradation gene ( opd) in aggregating and non-aggregating filamentous nitrogen-fixing cyanobacteria

Science.gov (United States)

Li, Qiong; Tang, Qing; Xu, Xudong; Gao, Hong

2010-11-01

Genetic engineering in filamentous N2-fixing cyanobacteria usually involves Anabaena sp. PCC 7120 and several other non-aggregating species. Mass culture and harvest of such species are more energy consuming relative to aggregating species. To establish a gene transfer system for aggregating species, we tested many species of Anabaena and Nostoc, and identified Nostoc muscorum FACHB244 as a species that can be genetically manipulated using the conjugative gene transfer system. To promote biodegradation of organophosphorus pollutants in aquatic environments, we introduced a plasmid containing the organophosphorus-degradation gene ( opd) into Anabaena sp. PCC 7120 and Nostoc muscorum FACHB244 by conjugation. The opd gene was driven by a strong promoter, P psbA . From both species, we obtained transgenic strains having organophosphorus-degradation activities. At 25°C, the whole-cell activities of the transgenic Anabaena and Nostoc strains were 0.163±0.001 and 0.289±0.042 unit/μg Chl a, respectively. However, most colonies resulting from the gene transfer showed no activity. PCR and DNA sequencing revealed deletions or rearrangements in the plasmid in some of the colonies. Expression of the green fluorescent protein gene from the same promoter in Anabaena sp. PCC 7120 showed similar results. These results suggest that there is the potential to promote the degradation of organophosphorus pollutants with transgenic cyanobacteria and that selection of high-expression transgenic colonies is important for genetic engineering of Anabaena and Nostoc species. For the first time, we established a gene transfer and expression system in an aggregating filamentous N2-fixing cyanobacterium. The genetic manipulation system of Nostoc muscorum FACHB244 could be utilized in the elimination of pollutants and large-scale production of valuable proteins or metabolites.

INFLUENCE OF HIGH LIGHT INTENSITY ON THE CELLS OF CYANOBACTERIA ANABAENA VARIABILIS SP. ATCC 29413

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OPRIŞ SANDA

2012-12-01

Full Text Available In this article is presented the result of research regardind the effect of high light intensity on the cells of Anabaena variabilis sp. ATCC 29413, the main objective is to study the adaptation of photosynthetic apparatus to light stress. Samples were analyzed in the present of herbicide diuron (DCMU which blocks electron flow from photosystem II and without diuron. During treatment maximum fluorescence and photosystems efficiency are significantly reduced, reaching very low values compared with the blank, as a result of photoinhibition installation. Also by this treatment is shown the importance of the mechanisms by which cells detect the presence of light stress and react accordingly.

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

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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

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

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Caroline Chénard

2016-06-01

Full Text Available 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.

Physiological and biochemical responses of Synechococcus sp. PCC7942 to Irgarol 1051 and diuron.

Science.gov (United States)

Deng, Xiangyuan; Gao, Kun; Sun, Junlong

2012-10-15

Cyanobacteria are prokaryotic algae found in oceans and freshwaters worldwide. These organisms are important primary producers in aquatic ecosystems because they can provide essential food for grazers and herbivores. In this study, the physiological and biochemical responses of the freshwater cyanobacterium Synechococcus sp. PCC7942 to two organic booster biocides Irgarol 1051 and diuron were compared and evaluated using 96 h growth tests in a batch-culture system. The 96 h median effective concentrations (EC(50)) were 0.019 and 0.097 μmol L(-1) for Irgarol 1051 and diuron, respectively, which indicate that Irgarol 1051 is about 5 times more toxic than diuron to cyanobacteria. Moreover, remarkable physiological and biochemical responses occurred in the Irgarol 1051 and diuron treatments. Irgarol 1051 and diuron stimulated cyanobacterial growth, increased the soluble protein content, and enhanced the catalase (CAT) activity at low concentrations, but inhibited them at high concentrations. However, the malondialdehyde (MDA) and polysaccharide content of the cyanobacteria were only significantly affected by Irgarol 1051. These observations suggest that Irgarol 1051 and diuron are toxic to Synechococcus sp. PCC7942, and their use should be restricted in maritime industries. Copyright © 2012 Elsevier B.V. All rights reserved.

Effect of OX-VIRIN versus phytoplankton; Eficacia de OX.VIRIN frente a fitoplancton

Energy Technology Data Exchange (ETDEWEB)

Sevilla Miguel, E.; Peleato Sanchez, M. L.; Gomez-Moreno Calera, C.; Oros Monje, J.; Vergara Larrayad, Y.

2003-07-01

The effect of the peroxide biocides OX-VIRIN has been tested on the survival of several representative phytoplankton species. Scenedesmus vacuolatus green algae, Anabaena sp. PCC7120 filamentous cyanobacteria and Microcystis aeruginosa PCC7005 unicellular cyanobacteria have been used. The parameters used to control the effectiveness of the biocide have been the chlorophyll determination and re culture. It has been shown that OX-VIRIN at dosages of 0.2, 0.5 and 1% is lethal against Microcystis, Anabaena, and Scenedesmus vacuolatus (formerly called Chlorella fusca), being the first mentioned organisms the most sensible to the biocide. (Author)

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

Czech Academy of Sciences Publication Activity Database

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

2018-01-01

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

Cell wall amidase AmiC1 is required for cellular communication and heterocyst development in the cyanobacterium Anabaena PCC 7120 but not for filament integrity.

Science.gov (United States)

Berendt, Susanne; Lehner, Josef; Zhang, Yao Vincent; Rasse, Tobias M; Forchhammer, Karl; Maldener, Iris

2012-10-01

Filamentous cyanobacteria of the order Nostocales display typical properties of multicellular organisms. In response to nitrogen starvation, some vegetative cells differentiate into heterocysts, where fixation of N(2) takes place. Heterocysts provide a micro-oxic compartment to protect nitrogenase from the oxygen produced by the vegetative cells. Differentiation involves fundamental remodeling of the gram-negative cell wall by deposition of a thick envelope and by formation of a neck-like structure at the contact site to the vegetative cells. Cell wall-hydrolyzing enzymes, like cell wall amidases, are involved in peptidoglycan maturation and turnover in unicellular bacteria. Recently, we showed that mutation of the amidase homologue amiC2 gene in Nostoc punctiforme ATCC 29133 distorts filament morphology and function. Here, we present the functional characterization of two amiC paralogues from Anabaena sp. strain PCC 7120. The amiC1 (alr0092) mutant was not able to differentiate heterocysts or to grow diazotrophically, whereas the amiC2 (alr0093) mutant did not show an altered phenotype under standard growth conditions. In agreement, fluorescence recovery after photobleaching (FRAP) studies showed a lack of cell-cell communication only in the AmiC1 mutant. Green fluorescent protein (GFP)-tagged AmiC1 was able to complement the mutant phenotype to wild-type properties. The protein localized in the septal regions of newly dividing cells and at the neck region of differentiating heterocysts. Upon nitrogen step-down, no mature heterocysts were developed in spite of ongoing heterocyst-specific gene expression. These results show the dependence of heterocyst development on amidase function and highlight a pivotal but so far underestimated cellular process, the remodeling of peptidoglycan, for the biology of filamentous cyanobacteria.

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

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Tomohisa Hasunuma

2016-12-01

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

Utility of Synechocystis sp. PCC glutaredoxin A as a platform to study high-resolution mutagenesis of proteins.

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David B Knaff

2013-11-01

Full Text Available Glutaredoxin from the cyanobacterium Synechocystis sp. PCC 6803 is a small protein, containing only 88 amino acids, that participates in a large number of redox reactions, serving both as an electron donor for enzyme-catalyzed reductions and as a regulator of diverse metabolic pathways. The crystal structures of glutaredoxins from several species have been solved, including the glutaredoxin A isoform from the cyanobacterium Synechocystis sp. PCC 6803. We have utilized the small size of Synechocystis glutaredoxin A and its propensity to form protein crystals that diffract to high resolution to explore a long-standing question in biochemistry; i.e., what are the effects of mutations on protein structure and function? Taking advantage of these properties, we have initiated a long-term educational project that would examine the structural and biochemical changes in glutaredoxin as a function of single-point mutational replacements. Here, we report some of the mutational effects that we have observed to date.

MapA, an iron-regulated, cytoplasmic membrane protein in the cyanobacterium Synechococcus sp. strain PCC7942.

Science.gov (United States)

Webb, R; Troyan, T; Sherman, D; Sherman, L A

1994-08-01

Growth of Synechococcus sp. strain PCC 7942 in iron-deficient media leads to the accumulation of an approximately 34-kDa protein. The gene encoding this protein, mapA (membrane-associated protein A), has been cloned and sequenced (GenBank accession number, L01621). The mapA transcript is not detectable in normally grown cultures but is stably accumulated by cells grown in iron-deficient media. However, the promoter sequence for this gene does not resemble other bacterial iron-regulated promoters described to date. The carboxyl-terminal region of the derived amino acid sequence of MapA resembles bacterial proteins involved in iron acquisition, whereas the amino-terminal end of MapA has a high degree of amino acid identity with the abundant, chloroplast envelope protein E37. An approach employing improved cellular fractionation techniques as well as electron microscopy and immunocytochemistry was essential in localizing MapA protein to the cytoplasmic membrane of Synechococcus sp. strain PCC 7942. When these cells were grown under iron-deficient conditions, a significant fraction of MapA could also be localized to the thylakoid membranes.

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

Science.gov (United States)

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

2016-07-01

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

Arsenic Demethylation by a C·As Lyase in Cyanobacterium Nostoc sp. PCC 7120.

Science.gov (United States)

Yan, Yu; Ye, Jun; Xue, Xi-Mei; Zhu, Yong-Guan

2015-12-15

Arsenic, a ubiquitous toxic substance, exists mainly as inorganic forms in the environment. It is perceived that organoarsenicals can be demethylated and degraded into inorganic arsenic by microorganisms. Few studies have focused on the mechanism of arsenic demethylation in bacteria. Here, we investigated arsenic demethylation in a typical freshwater cyanobacterium Nostoc sp. PCC 7120. This bacterium was able to demethylate monomethylarsenite [MAs(III)] rapidly to arsenite [As(III)] and also had the ability to demethylate monomethylarsenate [MAs(V)] to As(III). The NsarsI encoding a C·As lyase responsible for MAs(III) demethylation was cloned from Nostoc sp. PCC 7120 and heterologously expressed in an As-hypersensitive strain Escherichia coli AW3110 (ΔarsRBC). Expression of NsarsI was shown to confer MAs(III) resistance through arsenic demethylation. The purified NsArsI was further identified and functionally characterized in vitro. NsArsI existed mainly as the trimeric state, and the kinetic data were well-fit to the Hill equation with K0.5 = 7.55 ± 0.33 μM for MAs(III), Vmax = 0.79 ± 0.02 μM min(-1), and h = 2.7. Both of the NsArsI truncated derivatives lacking the C-terminal 10 residues (ArsI10) or 23 residues (ArsI23) had a reduced ability of MAs(III) demethylation. These results provide new insights for understanding the important role of cyanobacteria in arsenic biogeochemical cycling in the environment.

Antifungal compounds from cyanobacteria.

Science.gov (United States)

Shishido, Tânia K; Humisto, Anu; Jokela, Jouni; Liu, Liwei; Wahlsten, Matti; Tamrakar, Anisha; Fewer, David P; Permi, Perttu; Andreote, Ana P D; Fiore, Marli F; Sivonen, Kaarina

2015-04-13

Cyanobacteria are photosynthetic prokaryotes found in a range of environments. They are infamous for the production of toxins, as well as bioactive compounds, which exhibit anticancer, antimicrobial and protease inhibition activities. Cyanobacteria produce a broad range of antifungals belonging to structural classes, such as peptides, polyketides and alkaloids. Here, we tested cyanobacteria from a wide variety of environments for antifungal activity. The potent antifungal macrolide scytophycin was detected in Anabaena sp. HAN21/1, Anabaena cf. cylindrica PH133, Nostoc sp. HAN11/1 and Scytonema sp. HAN3/2. To our knowledge, this is the first description of Anabaena strains that produce scytophycins. We detected antifungal glycolipopeptide hassallidin production in Anabaena spp. BIR JV1 and HAN7/1 and in Nostoc spp. 6sf Calc and CENA 219. These strains were isolated from brackish and freshwater samples collected in Brazil, the Czech Republic and Finland. In addition, three cyanobacterial strains, Fischerella sp. CENA 298, Scytonema hofmanni PCC 7110 and Nostoc sp. N107.3, produced unidentified antifungal compounds that warrant further characterization. Interestingly, all of the strains shown to produce antifungal compounds in this study belong to Nostocales or Stigonematales cyanobacterial orders.

Antifungal Compounds from Cyanobacteria

Directory of Open Access Journals (Sweden)

Tânia K. Shishido

2015-04-01

Full Text Available Cyanobacteria are photosynthetic prokaryotes found in a range of environments. They are infamous for the production of toxins, as well as bioactive compounds, which exhibit anticancer, antimicrobial and protease inhibition activities. Cyanobacteria produce a broad range of antifungals belonging to structural classes, such as peptides, polyketides and alkaloids. Here, we tested cyanobacteria from a wide variety of environments for antifungal activity. The potent antifungal macrolide scytophycin was detected in Anabaena sp. HAN21/1, Anabaena cf. cylindrica PH133, Nostoc sp. HAN11/1 and Scytonema sp. HAN3/2. To our knowledge, this is the first description of Anabaena strains that produce scytophycins. We detected antifungal glycolipopeptide hassallidin production in Anabaena spp. BIR JV1 and HAN7/1 and in Nostoc spp. 6sf Calc and CENA 219. These strains were isolated from brackish and freshwater samples collected in Brazil, the Czech Republic and Finland. In addition, three cyanobacterial strains, Fischerella sp. CENA 298, Scytonema hofmanni PCC 7110 and Nostoc sp. N107.3, produced unidentified antifungal compounds that warrant further characterization. Interestingly, all of the strains shown to produce antifungal compounds in this study belong to Nostocales or Stigonematales cyanobacterial orders.

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., E-mail: fdavies@mines.edu [Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, CO (United States); Work, Victoria H. [Civil and Environmental Engineering Division, Colorado School of Mines, Golden, CO (United States); Beliaev, Alexander S. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA (United States); Posewitz, Matthew C. [Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, CO (United States)

2014-06-19

The plant terpenoids limonene (C{sub 10}H{sub 16}) and α-bisabolene (C{sub 15}H{sub 24}) 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{sup −1} limonene and 0.6 mg L{sup −1} α-bisabolene through heterologous expression of the Mentha spicatal-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 or 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.

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.

Engineering Limonene and Bisabolene Production in Wild Type and a Glycogen-Deficient Mutant of Synechococcus sp. PCC 7002.

Science.gov (United States)

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

2014-01-01

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 spicatal-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 or 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.

Engineering Limonene and Bisabolene Production in Wild Type and a Glycogen-Deficient Mutant of Synechococcus sp. PCC 7002

International Nuclear Information System (INIS)

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

2014-01-01

The plant terpenoids limonene (C 10 H 16 ) and α-bisabolene (C 15 H 24 ) 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 spicatal-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 or 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.

0589-0600_ESM.docx

Indian Academy of Sciences (India)

Sushila Rajagopal

Characterization of a DUF820 family protein Alr3200 of the cyanobacterium Anabaena sp. strain PCC7120. Prashanth S Raghavan, Gagan D Gupta, Hema Rajaram and Vinay Kumar. Supplementary material. Supplementary figure 1. Multiple Sequence Alignment of Alr3200 protein sequence with other cyanobacterial ...

Genome-derived insights into the biology of the hepatotoxic bloom-forming cyanobacterium Anabaena sp. strain 90

Directory of Open Access Journals (Sweden)

Wang Hao

2012-11-01

Full Text Available Abstract Background Cyanobacteria can form massive toxic blooms in fresh and brackish bodies of water and are frequently responsible for the poisoning of animals and pose a health risk for humans. Anabaena is a genus of filamentous diazotrophic cyanobacteria commonly implicated as a toxin producer in blooms in aquatic ecosystems throughout the world. The biology of bloom-forming cyanobacteria is poorly understood at the genome level. Results Here, we report the complete sequence and comprehensive annotation of the bloom-forming Anabaena sp. strain 90 genome. It comprises two circular chromosomes and three plasmids with a total size of 5.3 Mb, encoding a total of 4,738 genes. The genome is replete with mobile genetic elements. Detailed manual annotation demonstrated that almost 5% of the gene repertoire consists of pseudogenes. A further 5% of the genome is dedicated to the synthesis of small peptides that are the products of both ribosomal and nonribosomal biosynthetic pathways. Inactivation of the hassallidin (an antifungal cyclic peptide biosynthetic gene cluster through a deletion event and a natural mutation of the buoyancy-permitting gvpG gas vesicle gene were documented. The genome contains a large number of genes encoding restriction-modification systems. Two novel excision elements were found in the nifH gene that is required for nitrogen fixation. Conclusions Genome analysis demonstrated that this strain invests heavily in the production of bioactive compounds and restriction-modification systems. This well-annotated genome provides a platform for future studies on the ecology and biology of these important bloom-forming cyanobacteria.

Azolla-Anabaena Relationship

Science.gov (United States)

Ray, Thomas B.; Mayne, Berger C.; Toia, Robert E.; Peters, Gerald A.

1979-01-01

Photosynthesis in the Azolla-Anabaena association was characterized with respect to photorespiration, early products of photosynthesis, and action spectra. Photorespiration as evidenced by an O2 inhibition of photosynthesis and an O2-dependent CO2 compensation concentration was found to occur in the association, and endophyte-free fronds, but not in the endophytic Anabaena. Analysis of the early products of photosynthesis indicated that both the fern and cyanobacterium fix CO2 via the Calvin cycle. The isolated endophytic Anabaena did not release significant amounts of amino acids synthesized from recently fixed carbon. The action spectra for photosynthesis in the Azolla-Anabaena association indicated that the maximum quantum yield is between 650 and 670 nanometers, while in the endophyte the maximum is between 580 and 640 nanometers. Although the endophytic cyanobacterium is photosynthetically competent, any contribution it makes to photosynthesis in the intact association was not apparent in the action spectrum. PMID:16661055

Network analysis of transcriptomics expands regulatory landscapes in Synechococcus sp. PCC 7002

Energy Technology Data Exchange (ETDEWEB)

McClure, Ryan S.; Overall, Christopher C.; McDermott, Jason E.; Hill, Eric A.; Markillie, Lye Meng; McCue, Lee Ann; Taylor, Ronald C.; Ludwig, Marcus; Bryant, Donald A.; Beliaev, Alexander S.

2016-08-27

Cyanobacterial regulation of gene expression must contend with a genome organization that lacks apparent functional context, as the majority of cellular processes and metabolic pathways are encoded by genes found at disparate locations across the genome. In addition, the fact that coordinated regulation of cyanobacterial cellular machinery takes place with significantly fewer transcription factors, compared to other Eubacteria, suggests the involvement of post-transcriptional mechanisms and regulatory adaptations which are not fully understood. Global transcript abundance from model cyanobacterium Synechococcus sp. PCC 7002 grown under 42 different conditions was analyzed using context-likelihood of relatedness. The resulting 903-gene network, which was organized into 11 modules, not only allowed classification of cyanobacterial responses to specific environmental variables but provided insight into the transcriptional network topology and led to the expansion of predicted regulons. When used in conjunction with genome sequence, the global transcript abundance allowed identification of putative post-transcriptional changes in expression as well as novel potential targets of both DNA binding proteins and asRNA regulators. The results offer a new perspective into the multi-level regulation that governs cellular adaptations of fast-growing physiologically robust cyanobacterium Synechococcus sp. PCC 7002 to changing environmental variables. It also extends a methodological knowledge-based framework for studying multi-scale regulatory mechanisms that operate in cyanobacteria. Finally, it provides valuable context for integrating systems-level data to enhance evidence-driven genomic annotation, especially in organisms where traditional context analyses cannot be implemented due to lack of operon-based functional organization.

Enhanced biohydrogen production by the N{sub 2}-fixing cyanobacterium Anabaena siamensis strain TISTR 8012

Energy Technology Data Exchange (ETDEWEB)

Khetkorn, Wanthanee [Program of Biotechnology, Faculty of Science, Chulalongkorn University, Bangkok, 10330 (Thailand); Laboratory of Cyanobacterial Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Phayathai Road, Bangkok, 10330 (Thailand); Department of Photochemistry and Molecular Science, Uppsala University, Box 523, SE-75120, Uppsala (Sweden); Lindblad, Peter [Department of Photochemistry and Molecular Science, Uppsala University, Box 523, SE-75120, Uppsala (Sweden); Incharoensakdi, Aran [Laboratory of Cyanobacterial Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Phayathai Road, Bangkok, 10330 (Thailand)

2010-12-15

The efficiency of hydrogen production depends on several factors. We focused on external conditions leading to enhanced hydrogen production when using the N{sub 2}-fixing cyanobacterium Anabaena siamensis TISTR 8012, a novel strain isolated from a rice paddy field in Thailand. In this study, we controlled key factors affecting hydrogen production such as cell age, light intensity, time of light incubation and source of carbon. Our results showed an enhanced hydrogen production when cells, at log phase, were adapted under N{sub 2}-fixing condition using 0.5% fructose as carbon source and a continuous illumination of 200 {mu}E m{sup -2} s{sup -1} for 12 h under anaerobic incubation. The maximum hydrogen production rate was 32 {mu}mol H{sub 2} mg chl a{sup -1} h{sup -1}. This rate was higher than that observed in the model organisms Anabaena PCC 7120, Nostoc punctiforme ATCC 29133 and Synechocystis PCC 6803. This higher production was likely caused by a higher nitrogenase activity since we observed an upregulation of nifD. The production did not increase after 12 h which was probably due to an increased activity of the uptake hydrogenase as evidenced by an increased hupL transcript level. Interestingly, a proper adjustment of light conditions such as intensity and duration is important to minimize both the photodamage of the cells and the uptake hydrogenase activity. Our results indicate that A. siamensis TISTR 8012 has a high potential for hydrogen production with the ability to utilize sugars as substrate to produce hydrogen. (author)

The use of fluorescence microscopy and image analysis for rapid detection of non-producing revertant cells of Synechocystis sp. PCC6803 and Synechococcus sp. PCC7002.

Science.gov (United States)

Schulze, Katja; Lang, Imke; Enke, Heike; Grohme, Diana; Frohme, Marcus

2015-04-17

Ethanol production via genetically engineered cyanobacteria is a promising solution for the production of biofuels. Through the introduction of a pyruvate decarboxylase and alcohol dehydrogenase direct ethanol production becomes possible within the cells. However, during cultivation genetic instability can lead to mutations and thus loss of ethanol production. Cells then revert back to the wild type phenotype. A method for a rapid and simple detection of these non-producing revertant cells in an ethanol producing cell population is an important quality control measure in order to predict genetic stability and the longevity of a producing culture. Several comparable cultivation experiments revealed a difference in the pigmentation for non-producing and producing cells: the accessory pigment phycocyanin (PC) is reduced in case of the ethanol producer, resulting in a yellowish appearance of the culture. Microarray and western blot studies of Synechocystis sp. PCC6803 and Synechococcus sp. PCC7002 confirmed this PC reduction on the level of RNA and protein. Based on these findings we developed a method for fluorescence microscopy in order to distinguish producing and non-producing cells with respect to their pigmentation phenotype. By applying a specific filter set the emitted fluorescence of a producer cell with a reduced PC content appeared orange. The emitted fluorescence of a non-producing cell with a wt pigmentation phenotype was detected in red, and dead cells in green. In an automated process multiple images of each sample were taken and analyzed with a plugin for the image analysis software ImageJ to identify dead (green), non-producing (red) and producing (orange) cells. The results of the presented validation experiments revealed a good identification with 98 % red cells in the wt sample and 90 % orange cells in the producer sample. The detected wt pigmentation phenotype (red cells) in the producer sample were either not fully induced yet (in 48 h induced

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

Czech Academy of Sciences Publication Activity Database

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

2015-01-01

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

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

2013-01-01

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 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

Concerted changes in gene expression and cell physiology of the cyanobacterium Synechocystis sp. strain PCC 6803 during transitions between nitrogen and light-limited growth

NARCIS (Netherlands)

Aquirre von Wobeser, E.; Ibelings, B.W.; Bok, J.M.; Krasikov, V.; Huisman, J.; Matthijs, H.C.P.

2011-01-01

Physiological adaptation and genome-wide expression profiles of the cyanobacterium Synechocystis sp. strain PCC 6803 in response to gradual transitions between nitrogen-limited and light-limited growth conditions were measured in continuous cultures. Transitions induced changes in pigment

Characterization of a DUF820 family protein Alr3200 of the ...

Indian Academy of Sciences (India)

The hypothetical protein 'Alr3200' of Anabaena sp. strain PCC7120 is highly conserved among cyanobacterialspecies. It is a member of the DUF820 (Domain of Unknown Function) protein family, and is predicted to have aDNase domain. Biochemical analysis revealed a Mg(II)-dependent DNase activity for Alr3200 with a ...

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

Directory of Open Access Journals (Sweden)

Jared M Fraser

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

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.

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.

Hydrogen uptake by Azolla-Anabaena

International Nuclear Information System (INIS)

Ruschel, A.P.; Freitas, J.R. de; Silva, P.M.

1984-01-01

The hydrogen uptake in the Azolla-Anabaena system is studied. Tritium is used as tracer. Plants are incubated under different atmosphere composition: a) Air + 3 H 2 ; b) Air + CO 2 + 3 H 2 + CO; c) Air + 3 H 2 + CO; d) Air + CO 2 + 3 H 2 + 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) [pt

Resistance to the photosystem II herbicide diuron is dominant to sensitivity in the cyanobacterium Synechococcus sp. PCC7942

OpenAIRE

Brusslan, Judy; Haselkorn, Robert

1989-01-01

The transformable cyanobacterium, Synechococcus sp. PCC7942, was used to study the genetics of resistance to the herbicide diuron. In wild-type cells, diuron binds to one of the core proteins, called D1, of photosystem II reaction centres. This binding prevents the transfer of electrons from QA, the primary quinone acceptor, to QB, which is necessary to create the charge separation that drives ATP synthesis. A single amino acid substitution in the D1 protein reduces diuron binding and confers...

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

Science.gov (United States)

Ehira, Shigeki; Takeuchi, Takuto; Higo, Akiyoshi

2018-02-01

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

Crystallization, X-ray diffraction analysis and SIRAS/molecular-replacenent phasing of three crystal forms of Anabaena sensory rhodopsin transducer

International Nuclear Information System (INIS)

Vogeley, Lutz; Luecke, Hartmut

2006-01-01

Crystals of Anabaena sensory rhodopsin transducer, the transducer for the cyanobacterial photosensor Anabaena sensory rhodopsin, obtained in the space groups P4, C2 and P2 1 2 1 2 1 diffract to 1.8, 2.1 and 2.0 Å, respectively. Phases for these crystal forms were obtained by SIRAS phasing using an iodide quick-soak derivative (P4) and molecular replacement (C2 and P2 1 2 1 2 1 ). Anabaena sensory rhodopsin transducer (ASRT) is a 14.7 kDa soluble signaling protein associated with the membrane-embedded light receptor Anabaena sensory rhodopsin (ASR) from Anabaena sp., a freshwater cyanobacterium. Crystals of ASRT were obtained in three different space groups, P4, C2 and P2 1 2 1 2 1 , which diffract to 1.8, 2.1 and 2.0 Å, respectively. Phases for one of these crystal forms (P4) were obtained by SIRAS phasing using an iodide quick-soak derivative and a partial model was built. Phases for the remaining crystal forms were obtained by molecular replacement using the partial model from the P4 crystal form

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

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

2009-01-01

Hfq proteins are common in many species of enterobacteria, where they participate in RNA folding and translational regulation through pairing of small RNAs and messenger RNAs. Hfq proteins share the distinctive Sm fold, and form ring-shaped structures similar to those of the Sm/Lsm proteins...... 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...

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

Hfq proteins are common in many species of enterobacteria, where they participate in RNA folding and translational regulation through pairing of small RNAs and messenger RNAs. Hfq proteins share the distinctive Sm fold, and form ring-shaped structures similar to those of the Sm/Lsm proteins...... 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...

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

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Watabe, Kazuyuki; Mimuro, Mamoru; Tsuchiya, Tohru

2014-11-01

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

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

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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

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

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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.

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

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Tao Sun

2017-08-01

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

The Genome Sequence of the Cyanobacterium Oscillatoria sp. PCC 6506 Reveals Several Gene Clusters Responsible for the Biosynthesis of Toxins and Secondary Metabolites▿

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Méjean, Annick; Mazmouz, Rabia; Mann, Stéphane; Calteau, Alexandra; Médigue, Claudine; Ploux, Olivier

2010-01-01

We report a draft sequence of the genome of Oscillatoria sp. PCC 6506, a cyanobacterium that produces anatoxin-a and homoanatoxin-a, two neurotoxins, and cylindrospermopsin, a cytotoxin. Beside the clusters of genes responsible for the biosynthesis of these toxins, we have found other clusters of genes likely involved in the biosynthesis of not-yet-identified secondary metabolites. PMID:20675499

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

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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.

Arsenic biotransformation by a cyanobacterium Nostoc sp. PCC 7120.

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Xue, Xi-Mei; Yan, Yu; Xiong, Chan; Raber, Georg; Francesconi, Kevin; Pan, Ting; Ye, Jun; Zhu, Yong-Guan

2017-09-01

Nostoc sp. PCC 7120 (Nostoc), a typical filamentous cyanobacterium ubiquitous in aquatic system, is recognized as a model organism to study prokaryotic cell differentiation and nitrogen fixation. In this study, Nostoc cells incubated with arsenite (As(III)) for two weeks were extracted with dichloromethane/methanol (DCM/MeOH) and the extract was partitioned between water and DCM. Arsenic species in aqueous and DCM layers were determined using high performance liquid chromatography - inductively coupled plasma mass spectrometer/electrospray tandem mass spectrometry (HPLC-ICPMS/ESIMSMS). In addition to inorganic arsenic (iAs), the aqueous layer also contained monomethylarsonate (MAs(V)), dimethylarsinate (DMAs(V)), and the two arsenosugars, namely a glycerol arsenosugar (Oxo-Gly) and a phosphate arsenosugar (Oxo-PO4). Two major arsenosugar phospholipids (AsSugPL982 and AsSugPL984) were detected in DCM fraction. Arsenic in the growth medium was also investigated by HPLC/ICPMS and shown to be present mainly as the inorganic forms As(III) and As(V) accounting for 29%-38% and 29%-57% of the total arsenic respectively. The total arsenic of methylated arsenic, arsenosugars, and arsenosugar phospholipids in Nostoc cells with increasing As(III) exposure were not markedly different, indicating that the transformation to organoarsenic in Nostoc was not dependent on As(III) concentration in the medium. Our results provide new insights into the role of cyanobacteria in the biogeochemical cycling of arsenic. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

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Rajib Saha

2016-05-01

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

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

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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.

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

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Rajib Saha

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

Azolla-Anabaena Relationship 1

Science.gov (United States)

Meeks, John C.; Steinberg, Nisan A.; Enderlin, Carol S.; Joseph, Cecillia M.; Peters, Gerald A.

1987-01-01

The major radioactive products of the fixation of [13N]N2 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 [13N]N2-derived 13NH4+ after longer incubation periods was attributed to the spatial separation between the site of N2-fixation (Anabaena) and a second, major site of assimilation (Azolla). Initially, glutamine was the most highly radioactive organic product formed from [13N]N2, 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 [13N]N2-derived 13NH4+, 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-Anabaena. PMID:16665538

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.

The Multiple Functions of Common Microbial Carbon Polymers, Glycogen and PHB, during Stress Responses in the Non-Diazotrophic Cyanobacterium Synechocystis sp. PCC 6803.

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Damrow, Ramon; Maldener, Iris; Zilliges, Yvonne

2016-01-01

Classical microbial carbon polymers such as glycogen and polyhydroxybutyrate (PHB) have a crucial impact as both a sink and a reserve under macronutrient stress conditions. Most microbial species exclusively synthesize and degrade either glycogen or PHB. A few bacteria such as the phototrophic model organism Synechocystis sp. PCC 6803 surprisingly produce both physico-chemically different polymers under conditions of high C to N ratios. For the first time, the function and interrelation of both carbon polymers in non-diazotrophic cyanobacteria are analyzed in a comparative physiological study of single- and double-knockout mutants (ΔglgC; ΔphaC; ΔglgC/ΔphaC), respectively. Most of the observed phenotypes are explicitly related to the knockout of glycogen synthesis, highlighting the metabolic, energetic, and structural impact of this process whenever cells switch from an active, photosynthetic 'protein status' to a dormant 'glycogen status'. The carbon flux regulation into glycogen granules is apparently crucial for both phycobilisome degradation and thylakoid layer disassembly in the presence of light. In contrast, PHB synthesis is definitely not involved in this primary acclimation response. Moreover, the very weak interrelations between the two carbon-polymer syntheses indicate that the regulation and role of PHB synthesis in Synechocystis sp. PCC 6803 is different from glycogen synthesis.

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

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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.

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

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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.

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

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Chénard, Caroline; Wirth, Jennifer F; Suttle, Curtis A

2016-06-14

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. Filamentous cyanobacteria belonging to the genus Nostoc are widespread and ecologically important in freshwater, yet little is known about the genomic content of their viruses. Here we report the first genomic analysis of cyanophages infecting

Nezha, a novel active miniature inverted-repeat transposable element in cyanobacteria

International Nuclear Information System (INIS)

Zhou Fengfeng; Tran Thao; Xu Ying

2008-01-01

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

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)

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

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Ana María Sánchez-Riego

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

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

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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

Looking at the stability of life-support microorganisms in space : the MELGEN activity highlights the cyanobacterium Arthrospira sp. PCC8005

Science.gov (United States)

Morin, Nicolas

The MELGEN activity (MELiSSA Genetic Stability Study) mainly covers the molecular aspects of the regenerative life-support system MELiSSA (Micro-Ecological Life Support System Alternative) of the European Space Agency (ESA). The general objective of MELGEN is to establish and validate methods and the related hardware in order to detect genetic instability and microbial contaminants in the MELISSA compartments. This includes (1) a genetic description of the MELISSA strains, (2) studies of microbial behavior and genetic stability in bioreactors and (3) the detection of chemical, genetical and biological contamination and their effect on microbial metabolism. Selected as oxygen producer and complementary food source, the cyanobacterium Arthrospira sp. PCC8005 plays a major role within the MELiSSA loop. As the genomic information on this organism was insufficient, sequencing of its genome was proposed at the French National Sequencing Center, Genoscope, as a joint effort between ESA and different laboratories. So far, a preliminary assembly of 16 contigs representing circa 6.3 million basepairs was obtained. Even though the finishing of the genome is on its way, automatic annotation of the contigs has already been performed on the MaGe annotation platform, and curation of the sequence is currently being carried out, with a special focus on biosynthesis pathways, photosynthesis, and maintenance processes of the cell. According to the index of repetitiveness described by Haubold and Wiehe (2006), we discovered that the genome of Arthrospira sp. is among the 50 most repeated bacterial genomes sequenced to date. Thanks to the sequencing project, we have identified and catalogued mobile genetics elements (MGEs) dispersed throughout the unique chromosome of this cyanobacterium. They represent a quite large proportion of the genome, as genes identified as putative transposases are indeed found in circa 5 Results : We currently have a first draft of the complete genome of

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

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

Czech Academy of Sciences Publication Activity Database

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

2008-01-01

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

Optimization of pH and nitrogen for enhanced hydrogen production by Synechocystis sp. PCC 6803 via statistical and machine learning methods.

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Burrows, Elizabeth H; Wong, Weng-Keen; Fern, Xiaoli; Chaplen, Frank W R; Ely, Roger L

2009-01-01

The nitrogen (N) concentration and pH of culture media were optimized for increased fermentative hydrogen (H(2)) production from the cyanobacterium, Synechocystis sp. PCC 6803. The optimization was conducted using two procedures, response surface methodology (RSM), which is commonly used, and a memory-based machine learning algorithm, Q2, which has not been used previously in biotechnology applications. Both RSM and Q2 were successful in predicting optimum conditions that yielded higher H(2) than the media reported by Burrows et al., Int J Hydrogen Energy. 2008;33:6092-6099 optimized for N, S, and C (called EHB-1 media hereafter), which itself yielded almost 150 times more H(2) than Synechocystis sp. PCC 6803 grown on sulfur-free BG-11 media. RSM predicted an optimum N concentration of 0.63 mM and pH of 7.77, which yielded 1.70 times more H(2) than EHB-1 media when normalized to chlorophyll concentration (0.68 +/- 0.43 micromol H(2) mg Chl(-1) h(-1)) and 1.35 times more when normalized to optical density (1.62 +/- 0.09 nmol H(2) OD(730) (-1) h(-1)). Q2 predicted an optimum of 0.36 mM N and pH of 7.88, which yielded 1.94 and 1.27 times more H(2) than EHB-1 media when normalized to chlorophyll concentration (0.77 +/- 0.44 micromol H(2) mg Chl(-1) h(-1)) and optical density (1.53 +/- 0.07 nmol H(2) OD(730) (-1) h(-1)), respectively. Both optimization methods have unique benefits and drawbacks that are identified and discussed in this study. (c) 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009.

Proteome analysis reveals distinct uranium stress response in two strains of Cyanobacteria native to Indian paddy fields

International Nuclear Information System (INIS)

Panda, Bandita; Basu, Bhakti; Acharya, Celin; Rajaram, Hema; Apte, Shree Kumar

2017-01-01

Uranium present in phosphate fertilizer contaminates agricultural land. Uranium exerts chemical toxicity to the resident biota as it induces oxidative stress by generating free radicals. Two strains of nitrogen fixing cyanobacteria viz., Anabaena PCC 7120 and L-31 native to Indian paddy, regularly experience oxidative stress induced by different stresses and heavy metals. The present study investigated their response to uranium exposure at proteomic level. LD_5_0 dose for Anabaena 7120 and Anabaena L-31 was determined to be 75 μM and 200 μM uranyl carbonate exposure for 3 h. A total of 79 proteins from Anabaena 7120 and 64 proteins from Anabaena L-31 were identified by MALDI mass spectrometry, of which levels of 45 and 27 proteins respectively were found to be differentially modulated in the two strains in response to uranium exposure. The differentially expressed proteins belonged to the major functional categories of photosynthesis, carbon metabolism and oxidative stress alleviation, commensurate with their uranium tolerance. Better oxidative stress management, and maintenance of metabolic and energy homeostasis lead to superior uranium tolerance in Anabaena L-31 as compared to Anabaena PCC 7120

Penggunaan precipitated calcium carbonate (PCC sebagai filler untuk sol karet sepatu olah raga

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Herminiwati

2010-12-01

Full Text Available Abstract The objective of the research was to investigate the utilization of Precipitated Calcium Carbonate (PCC as filler in producing sport shoe rubber soles. PCC is a white filler needed for production of nonblack colour rubber products. There are four types of PCC that have been used including two local PCC from Wonosari and East Java, and two imported PCC from Japan and Taiwan. The amount of PCC added into the sport shoe sole rubber compound was varied in 30,45,60,75 and 90 per hundred rubber (phr. The compounding was carried-out by using two roll mills machine, and the compound was subsequently measured their optimum vulcanization time by using rheometer. The produced compound was then subjected to vulcanistion process by using hydrolic press at temperature 1500C and pressure 150 kg/ cm2. The quality of shoes sole vulcanisates were compare to standard quality of SNI. 12-7075-2005 about cemented system sport shoes. The results indicated that the best formula of rubber compound for sport shoes sole were made by using NR 80 phr, NBR 20 phr, paraffinic oil 10 phr, aluminium silicate 30 phr, ZnO 5 phr, TiO2 10 phr, stearic acid 1 phr, vulkanox SP 1 phr, paraffin wax 1 phr, TMTD 0,5 phr, CBS 2 phr, sulphur 1,2 phr with the amount of PCC Actifort 700 of 45 phr. The best formula meet the requirement SNI 12-7075-2005 and they were characterized by tensile sterength 16,79 N/mm2, elongation at break 529,92% tear resistance 9,06 N/mm2, specific gravity 1,28 g/cm3, hardness 55 shore A, Grasselli absrassion resistancing filler. The local PCC from Wonosari can be used for substitution of the imported PCC as the white filler for the production of rubber compound sport shoes sole. However, particle size reduction and coating or surface treatment of local PCC were needed for improving the quality and the role of reinforcing filler.

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: 3.035, year: 2015

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

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Pils, D; Schmetterer, G

2001-09-25

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

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

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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

Biochemical Characterization of Putative Adenylate Dimethylallyltransferase and Cytokinin Dehydrogenase from Nostoc sp. PCC 7120.

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Frébortová, Jitka; Greplová, Marta; Seidl, Michael F; Heyl, Alexander; Frébort, Ivo

2015-01-01

Cytokinins, a class of phytohormones, are adenine derivatives common to many different organisms. In plants, these play a crucial role as regulators of plant development and the reaction to abiotic and biotic stress. Key enzymes in the cytokinin synthesis and degradation in modern land plants are the isopentyl transferases and the cytokinin dehydrogenases, respectively. Their encoding genes have been probably introduced into the plant lineage during the primary endosymbiosis. To shed light on the evolution of these proteins, the genes homologous to plant adenylate isopentenyl transferase and cytokinin dehydrogenase were amplified from the genomic DNA of cyanobacterium Nostoc sp. PCC 7120 and expressed in Escherichia coli. The putative isopentenyl transferase was shown to be functional in a biochemical assay. In contrast, no enzymatic activity was detected for the putative cytokinin dehydrogenase, even though the principal domains necessary for its function are present. Several mutant variants, in which conserved amino acids in land plant cytokinin dehydrogenases had been restored, were inactive. A combination of experimental data with phylogenetic analysis indicates that adenylate-type isopentenyl transferases might have evolved several times independently. While the Nostoc genome contains a gene coding for protein with characteristics of cytokinin dehydrogenase, the organism is not able to break down cytokinins in the way shown for land plants.

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

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

2016-04-01

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.

Photosynthetic Versatility in the Genome of Geitlerinema sp. PCC 9228 (Formerly Oscillatoria limnetica 'Solar Lake'), a Model Anoxygenic Photosynthetic Cyanobacterium.

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Grim, Sharon L; Dick, Gregory J

2016-01-01

Anoxygenic cyanobacteria that use sulfide as the electron donor for photosynthesis are a potentially influential but poorly constrained force on Earth's biogeochemistry. Their versatile metabolism may have boosted primary production and nitrogen cycling in euxinic coastal margins in the Proterozoic. In addition, they represent a biological mechanism for limiting the accumulation of atmospheric oxygen, especially before the Great Oxidation Event and in the low-oxygen conditions of the Proterozoic. In this study, we describe the draft genome sequence of Geitlerinema sp. PCC 9228, formerly Oscillatoria limnetica 'Solar Lake', a mat-forming diazotrophic cyanobacterium that can switch between oxygenic photosynthesis and sulfide-based anoxygenic photosynthesis (AP). Geitlerinema possesses three variants of psbA , which encodes protein D1, a core component of the photosystem II reaction center. Phylogenetic analyses indicate that one variant is closely affiliated with cyanobacterial psbA genes that code for a D1 protein used for oxygen-sensitive processes. Another version is phylogenetically similar to cyanobacterial psbA genes that encode D1 proteins used under microaerobic conditions, and the third variant may be cued to high light and/or elevated oxygen concentrations. Geitlerinema has the canonical gene for sulfide quinone reductase (SQR) used in cyanobacterial AP and a putative transcriptional regulatory gene in the same operon. Another operon with a second, distinct sqr and regulatory gene is present, and is phylogenetically related to sqr genes used for high sulfide concentrations. The genome has a comprehensive nif gene suite for nitrogen fixation, supporting previous observations of nitrogenase activity. Geitlerinema possesses a bidirectional hydrogenase rather than the uptake hydrogenase typically used by cyanobacteria in diazotrophy. Overall, the genome sequence of Geitlerinema sp. PCC 9228 highlights potential cyanobacterial strategies to cope with fluctuating

Quantitative iTRAQ LC-MS/MS proteomics reveals metabolic responses to biofuel ethanol in cyanobacterial Synechocystis sp. PCC 6803.

Science.gov (United States)

Qiao, Jianjun; Wang, Jiangxin; Chen, Lei; Tian, Xiaoxu; Huang, Siqiang; Ren, Xiaoyue; Zhang, Weiwen

2012-11-02

Recent progress in metabolic engineering has led to autotrophic production of ethanol in various cyanobacterial hosts. However, cyanobacteria are known to be sensitive to ethanol, which restricts further efforts to increase ethanol production levels in these renewable host systems. To understand the mechanisms of ethanol tolerance so that engineering more robust cyanobacterial hosts can be possible, in this study, the responses of model cyanobacterial Synechocystis sp. PCC 6803 to ethanol were determined using a quantitative proteomics approach with iTRAQ LC-MS/MS technologies. The resulting high-quality proteomic data set consisted of 24,887 unique peptides corresponding to 1509 identified proteins, a coverage of approximately 42% of the predicted proteins in the Synechocystis genome. Using a cutoff of 1.5-fold change and a p-value less than 0.05, 135 and 293 unique proteins with differential abundance levels were identified between control and ethanol-treated samples at 24 and 48 h, respectively. Functional analysis showed that the Synechocystis cells employed a combination of induced common stress response, modifications of cell membrane and envelope, and induction of multiple transporters and cell mobility-related proteins as protection mechanisms against ethanol toxicity. Interestingly, our proteomic analysis revealed that proteins related to multiple aspects of photosynthesis were up-regulated in the ethanol-treated Synechocystis cells, consistent with increased chlorophyll a concentration in the cells upon ethanol exposure. The study provided the first comprehensive view of the complicated molecular mechanisms against ethanol stress and also provided a list of potential gene targets for further engineering ethanol tolerance in Synechocystis PCC 6803.

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

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Hammouda, O H.E. [Botany Department, Faculty of Science, Cairo University, Beni-Suef branch. Beni Suef (Egypt); Borbely, G [Institute of plant physiology, Biological Research Center, Szeged H-6701, (Hungary)

1995-10-01

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.

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)

Hammouda, O.H.E.; Borbely, G.

1995-01-01

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

First report of an Anabaena Bory strain containing microcystin-LR in ...

African Journals Online (AJOL)

In South Africa, little is known about the production of microcystin by the genus Anabaena Bory. In April 2012, during a cyanobacterial bloom event in Theewaterskloof Dam, Western Cape province, the plankton was sampled on 10 occasions. The dominant algae belonged to the genus Anabaena, a family of filamentous ...

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

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Hiroko eIijima

2015-04-01

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

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

Science.gov (United States)

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

2011-02-01

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

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

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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.

Biocomputional construction of a gene network under acid stress in Synechocystis sp. PCC 6803.

Science.gov (United States)

Li, Yi; Rao, Nini; Yang, Feng; Zhang, Ying; Yang, Yang; Liu, Han-ming; Guo, Fengbiao; Huang, Jian

2014-01-01

Acid stress is one of the most serious threats that cyanobacteria have to face, and it has an impact at all levels from genome to phenotype. However, very little is known about the detailed response mechanism to acid stress in this species. We present here a general analysis of the gene regulatory network of Synechocystis sp. PCC 6803 in response to acid stress using comparative genome analysis and biocomputational prediction. In this study, we collected 85 genes and used them as an initial template to predict new genes through co-regulation, protein-protein interactions and the phylogenetic profile, and 179 new genes were obtained to form a complete template. In addition, we found that 11 enriched pathways such as glycolysis are closely related to the acid stress response. Finally, we constructed a regulatory network for the intricate relationship of these genes and summarize the key steps in response to acid stress. This is the first time a bioinformatic approach has been taken systematically to gene interactions in cyanobacteria and the elaboration of their cell metabolism and regulatory pathways under acid stress, which is more efficient than a traditional experimental study. The results also provide theoretical support for similar research into environmental stresses in cyanobacteria and possible industrial applications. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

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

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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

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

International Nuclear Information System (INIS)

Iman, R.L.; Shortencarier, M.J.; Johnson, J.D.

1995-01-01

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

Diversification of DnaA dependency for DNA replication in cyanobacterial evolution.

Science.gov (United States)

Ohbayashi, Ryudo; Watanabe, Satoru; Ehira, Shigeki; Kanesaki, Yu; Chibazakura, Taku; Yoshikawa, Hirofumi

2016-05-01

Regulating DNA replication is essential for all living cells. The DNA replication initiation factor DnaA is highly conserved in prokaryotes and is required for accurate initiation of chromosomal replication at oriC. DnaA-independent free-living bacteria have not been identified. The dnaA gene is absent in plastids and some symbiotic bacteria, although it is not known when or how DnaA-independent mechanisms were acquired. Here, we show that the degree of dependency of DNA replication on DnaA varies among cyanobacterial species. Deletion of the dnaA gene in Synechococcus elongatus PCC 7942 shifted DNA replication from oriC to a different site as a result of the integration of an episomal plasmid. Moreover, viability during the stationary phase was higher in dnaA disruptants than in wild-type cells. Deletion of dnaA did not affect DNA replication or cell growth in Synechocystis sp. PCC 6803 or Anabaena sp. PCC 7120, indicating that functional dependency on DnaA was already lost in some nonsymbiotic cyanobacterial lineages during diversification. Therefore, we proposed that cyanobacteria acquired DnaA-independent replication mechanisms before symbiosis and such an ancestral cyanobacterium was the sole primary endosymbiont to form a plastid precursor.

Approach to improve the productivity of bioactive compounds of the cyanobacterium Anabaena oryzae using factorial design

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Ragaa A. Hamouda

2017-09-01

Full Text Available Cyanobacteria are one of the richest sources of biomedical relevant compounds with extensive therapeutic pharmaceutical applications and are also known as producer of intracellular and extracellular metabolites with diverse biological activities. The genus Anabaena sp. is known to produce antimicrobial compounds, like phycocyanin and others. The goal of this study was to optimize the production of these bioactive compounds. The Plackett–Burman experimental design was used to screen and evaluate the important medium components that influence the production of bioactive compounds. In this present study, eight independent factors including NaNO3, K2HPO4, MgSO4·7H2O, CaCl2, citric acid, ammonium ferric citrate, ethylene diamine tetraacetic acid disodium magnesium salt (EDTA-Na2Mg and Na2CO3 were surveyed and the effective variables for algal components production of Anabaena oryzae were determined using two-levels Plackett–Burman design. Results analysis showed that the best medium components were NaNO3 (2.25 g l−1; K2HPO4 (0.02 g l−1; MgSO4 (0.0375 g l−1; CaCl2 (0.018 g l−1; citric acid (0.009 g l−1; ammonium ferric citrate (0.009 g l−1 and EDTA-Na2 (0.0015 g l−1 respectively. The total chlorophyll-a, carotenoids, phenol, tannic acid and flavonoid contents in crude extract of Anabaena oryzae were determined. They were 47.7, 4.11, 0.256, 1.046 and 1.83 μg/ml, respectively. The antioxidant capacity was 62.81%.

集胞藻PCC6803基因slr2049定点突变及其体内重组功能研究%Site-directed mutation of the gene slr2049 from Synechocy-stis sp.PCC 6803 and the study on the function

Institute of Scientific and Technical Information of China (English)

朱超; 陈思礼

2013-01-01

在Synechocystis sp.PCC 6803中找到与cpeS具有高度同源性的基因slr2049.采用PCR从Synechocystis sp.PCC 6803 DNA中扩增出cpcB,slr2049,hol,pcyA 4个基因；定点突变试剂盒构建8个突变体slr2049 (H21S)、slr2049 (L23S)、slr2049 (A24S)、slr2049 (F25S)、slr2049(W72L)、slr2049(G84S)、slr2049(R107S)和slr2049(Y124S)；将它们与表达载体pCDFDuet-1和pET-23a(+)相连构建pCDF-cpcB-slr2049野生型和pCDF-cpcB-slr2049突变体以及pET-ho1-pcyA,进行高效表达,用亲和层析柱纯化,产物用SDS-PAGE和光谱检测.研究表明:突变体slr2049(H21S)、slr2049(L23S)、slr2049(F25S)、slr2049 (W72L)、slr2049 (G84S)、slr2049(Y124S)与野生型slr2049催化获得的重组藻蓝蛋白β亚基具有与天然藻蓝蛋白β亚基相似的光谱特性,其他2个突变体slr2049 (A24S)和slr2049(R107S)催化的产物则没有光谱特性.由此推测,第24位丙氨酸和第107位精氨酸可能是slr2049酶活性的必需氨基酸,其所处位置是slr2049的活性位点.%We have found gene slr2049 in Synechocystis sp.PCC 6803 which was homol ogous to the bilin lyase gene cpeS by some softwares for homologous analysis.Four genes were amplifed from DNA of Synechocystis sp.PCC 6803 by PCR.Eight mutants which were slr2049 (H21S),slr2049 (L23S),slr2049 (A24S),slr2049 (F25S),slr2049 (W72L),slr2049(G84S),slr2049(R107S)and sl-r2049(Y124S)were constructed by Mutan BEST Kit.pCDF-cpcB-slr2049,pCDF-cpcB-slr2049 mutants and pET-ho1-pcyA were formed from the linkage of four genes and mutants with pCDFDuet-land pET-23a (+).They were expressed and purified by affinity column.Proteins were detected by SDS-PAGE,absorption and fluorescence spectra.The results showed that phycocyanin β-subunit which had the same spectral characteristic with native phycocyanin β-subunit were catalysed by the protein encoded by gene slr2049 and mutants slr2049 (H21S),slr2049(L23S),slr2049(F25S),slr2049 (W72L),slr2049 (G84S),slr2049 (Y124S).The rest of mutants slr2049(A24S

Physiological regulation of isocitrate dehydrogenase and the role of 2-oxoglutarate in Prochlorococcus sp. strain PCC 9511.

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María Agustina Domínguez-Martín

Full Text Available The enzyme isocitrate dehydrogenase (ICDH; EC 1.1.1.42 catalyzes the oxidative decarboxylation of isocitrate, to produce 2-oxoglutarate. The incompleteness of the tricarboxylic acids cycle in marine cyanobacteria confers a special importance to isocitrate dehydrogenase in the C/N balance, since 2-oxoglutarate can only be metabolized through the glutamine synthetase/glutamate synthase pathway. The physiological regulation of isocitrate dehydrogenase was studied in cultures of Prochlorococcus sp. strain PCC 9511, by measuring enzyme activity and concentration using the NADPH production assay and Western blotting, respectively. The enzyme activity showed little changes under nitrogen or phosphorus starvation, or upon addition of the inhibitors DCMU, DBMIB and MSX. Azaserine, an inhibitor of glutamate synthase, induced clear increases in the isocitrate dehydrogenase activity and icd gene expression after 24 h, and also in the 2-oxoglutarate concentration. Iron starvation had the most significant effect, inducing a complete loss of isocitrate dehydrogenase activity, possibly mediated by a process of oxidative inactivation, while its concentration was unaffected. Our results suggest that isocitrate dehydrogenase responds to changes in the intracellular concentration of 2-oxoglutarate and to the redox status of the cells in Prochlorococcus.

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

Science.gov (United States)

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

2017-07-01

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

Absorption and emission spectroscopic characterization of blue-light receptor Slr1694 from Synechocystis sp. PCC6803.

Science.gov (United States)

Zirak, P; Penzkofer, A; Lehmpfuhl, C; Mathes, T; Hegemann, P

2007-01-03

The BLUF protein Slr1694 from the cyanobacterium Synechocystis sp. PCC6803 is characterized by absorption and emission spectroscopy. Slr1694 expressed from E. coli which non-covalently binds FAD, FMN, and riboflavin (called Slr1694(I)), and reconstituted Slr1694 which dominantly contains FAD (called Slr1694(II)) are investigated. The receptor conformation of Slr1694 (dark adapted form Slr1694(r)) is transformed to the putative signalling state (light adapted form Slr1694(s)) with red-shifted absorption and decreased fluorescence efficiency by blue-light excitation. In the dark at 22 degrees C, the signalling state recovers back to the initial receptor state with a time constants of about 14.2s for Slr1694(I) and 17s for Slr1694(II). Quantum yields of signalling state formation of approximately 0.63+/-0.07 for both Slr1694(I) and Slr1694(II) were determined by transient transmission measurements and intensity dependent steady-state transmission measurements. Extended blue-light excitation causes some bound flavin conversion to the hydroquinone form and some photo-degradation, both with low quantum efficiency. The flavin-hydroquinone re-oxidizes slowly back (time constant 5-9 min) to the initial flavoquinone form in the dark. A photo-cycle dynamics scheme is presented.

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

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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.

Photosynthetic versatility in the genome of Geitlerinema sp. PCC 9228 (formerly Oscillatoria limnetica ‘Solar Lake’, a model anoxygenic photosynthetic cyanobacterium

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Sharon L Grim

2016-10-01

Full Text Available Anoxygenic cyanobacteria that use sulfide as the electron donor for photosynthesis are a potentially influential but poorly constrained force on Earth’s biogeochemistry. Their versatile metabolism may have boosted primary production and nitrogen cycling in euxinic coastal margins in the Proterozoic. In addition, they represent a biological mechanism for limiting the accumulation of atmospheric oxygen, especially before the Great Oxidation Event and in the low-oxygen conditions of the Proterozoic. In this study, we describe the draft genome sequence of Geitlerinema sp. PCC 9228, formerly Oscillatoria limnetica ‘Solar Lake’, a mat-forming diazotrophic cyanobacterium that can switch between oxygenic photosynthesis and sulfide-based anoxygenic photosynthesis. Geitlerinema possesses three variants of psbA, which encodes protein D1, a core component of the photosystem II reaction center. Phylogenetic analyses indicate that one variant is closely affiliated with cyanobacterial psbA genes that code for a D1 protein used for oxygen-sensitive processes. Another version is phylogenetically similar to cyanobacterial psbA genes that encode D1 proteins used under microaerobic conditions, and the third variant may be cued to high light and/or elevated oxygen concentrations. Geitlerinema has the canonical gene for sulfide quinone reductase (SQR used in cyanobacterial anoxygenic photosynthesis and a putative transcriptional regulatory gene in the same operon. Another operon with a second, distinct sqr and regulatory gene is present, and is phylogenetically related to sqr genes used for high sulfide concentrations. The genome has a comprehensive nif gene suite for nitrogen fixation, supporting previous observations of nitrogenase activity. Geitlerinema possesses a bidirectional hydrogenase rather than the uptake hydrogenase typically used by cyanobacteria in diazotrophy. Overall, the genome sequence of Geitlerinema sp. PCC 9228 highlights potential

Photosynthetic Versatility in the Genome of Geitlerinema sp. PCC 9228 (Formerly Oscillatoria limnetica ‘Solar Lake’), a Model Anoxygenic Photosynthetic Cyanobacterium

Science.gov (United States)

Grim, Sharon L.; Dick, Gregory J.

2016-01-01

Anoxygenic cyanobacteria that use sulfide as the electron donor for photosynthesis are a potentially influential but poorly constrained force on Earth’s biogeochemistry. Their versatile metabolism may have boosted primary production and nitrogen cycling in euxinic coastal margins in the Proterozoic. In addition, they represent a biological mechanism for limiting the accumulation of atmospheric oxygen, especially before the Great Oxidation Event and in the low-oxygen conditions of the Proterozoic. In this study, we describe the draft genome sequence of Geitlerinema sp. PCC 9228, formerly Oscillatoria limnetica ‘Solar Lake’, a mat-forming diazotrophic cyanobacterium that can switch between oxygenic photosynthesis and sulfide-based anoxygenic photosynthesis (AP). Geitlerinema possesses three variants of psbA, which encodes protein D1, a core component of the photosystem II reaction center. Phylogenetic analyses indicate that one variant is closely affiliated with cyanobacterial psbA genes that code for a D1 protein used for oxygen-sensitive processes. Another version is phylogenetically similar to cyanobacterial psbA genes that encode D1 proteins used under microaerobic conditions, and the third variant may be cued to high light and/or elevated oxygen concentrations. Geitlerinema has the canonical gene for sulfide quinone reductase (SQR) used in cyanobacterial AP and a putative transcriptional regulatory gene in the same operon. Another operon with a second, distinct sqr and regulatory gene is present, and is phylogenetically related to sqr genes used for high sulfide concentrations. The genome has a comprehensive nif gene suite for nitrogen fixation, supporting previous observations of nitrogenase activity. Geitlerinema possesses a bidirectional hydrogenase rather than the uptake hydrogenase typically used by cyanobacteria in diazotrophy. Overall, the genome sequence of Geitlerinema sp. PCC 9228 highlights potential cyanobacterial strategies to cope with

Responses of Synechocystis sp. PCC 6803 to heterologous biosynthetic pathways

DEFF Research Database (Denmark)

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

2017-01-01

BACKGROUND: There are an increasing number of studies regarding genetic manipulation of cyanobacteria to produce commercially interesting compounds. The majority of these works study the expression and optimization of a selected heterologous pathway, largely ignoring the wholeness and complexity...... different compounds, the cyanogenic glucoside dhurrin and the diterpenoid 13R-manoyl oxide in Synechocystis PCC 6803. We used genome-scale metabolic modelling to study fluxes in individual reactions and pathways, and we determined the concentrations of key metabolites, such as amino acids, carotenoids...

Transcript analysis of the extended hyp-operon in the cyanobacteria Nostoc sp. strain PCC 7120 and Nostoc punctiforme ATCC 29133

Science.gov (United States)

2011-01-01

Background Cyanobacteria harbor two [NiFe]-type hydrogenases consisting of a large and a small subunit, the Hup- and Hox-hydrogenase, respectively. Insertion of ligands and correct folding of nickel-iron hydrogenases require assistance of accessory maturation proteins (encoded by the hyp-genes). The intergenic region between the structural genes encoding the uptake hydrogenase (hupSL) and the accessory maturation proteins (hyp genes) in the cyanobacteria Nostoc PCC 7120 and N. punctiforme were analysed using molecular methods. Findings The five ORFs, located in between the uptake hydrogenase structural genes and the hyp-genes, can form a transcript with the hyp-genes. An identical genomic localization of these ORFs are found in other filamentous, N2-fixing cyanobacterial strains. In N. punctiforme and Nostoc PCC 7120 the ORFs upstream of the hyp-genes showed similar transcript level profiles as hupS (hydrogenase structural gene), nifD (nitrogenase structural gene), hypC and hypF (accessory hydrogenase maturation genes) after nitrogen depletion. In silico analyzes showed that these ORFs in N. punctiforme harbor the same conserved regions as their homologues in Nostoc PCC 7120 and that they, like their homologues in Nostoc PCC 7120, can be transcribed together with the hyp-genes forming a larger extended hyp-operon. DNA binding studies showed interactions of the transcriptional regulators CalA and CalB to the promoter regions of the extended hyp-operon in N. punctiforme and Nostoc PCC 7120. Conclusions The five ORFs upstream of the hyp-genes in several filamentous N2-fixing cyanobacteria have an identical genomic localization, in between the genes encoding the uptake hydrogenase and the maturation protein genes. In N. punctiforme and Nostoc PCC 7120 they are transcribed as one operon and may form transcripts together with the hyp-genes. The expression pattern of the five ORFs within the extended hyp-operon in both Nostoc punctiforme and Nostoc PCC 7120 is similar to

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

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Philipp eSpät

2015-03-01

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

Aspects of nitrogen and carbon interchange in the Azolla-Anabaena symbiosis

International Nuclear Information System (INIS)

Peters, G.A.; Kaplan, D.; Meeks, J.C.; Buzby, K.M.; Marsh, B.H.; Corbin, J.L.

1985-01-01

The free-floating aquatic pteridophytes in the genus Azolla contain an N 2 -fixing cyanobacterium, Anabaena azollae, as a symbiont. Six extant species usually are recognized. In each species the symbiotic Anabaena can provide the total N requirement of the association via N 2 fixation and the Azolla sporophytes are capable of prolific vegetative reproduction in the absence of a combined N source. While vegetative reproduction and growth is more common, sexual reproduction occurs and presumably provides a means for survival during unfavorable environmental conditions. Azolla is heterosporous, producing both megasporocarps and microsporocarps on the same plant. Species demarcation is based primarily upon the morphology of these structures. Anabaena filaments are partitioned into both types of sporocarps during their development. The endophyte within the megasporocarp provides an inoculum for the developing sporophyte, maintaining the symbiosis. This report is restricted to studies conducted with the vegetatively propagated Azolla caroliniana - Anabaena azollae symbiosis grown on medium without combined N. It focuses on recent approaches to further elucidate aspects of host-endophyte interaction and incorporates analyses of soluble amino acids and ammonium, assays of ammonia assimilating enzymes, the use of [ 13 N]N 2 and the analysis of soluble sugars as well as 14 CO 2 -pulse chase studies. For orientation purposes the results are preceded by a description of the symbiosis. 39 references, 3 figures, 3 tables

Absorption and emission spectroscopic characterization of BLUF protein Slr1694 from Synechocystis sp. PCC6803 with roseoflavin cofactor.

Science.gov (United States)

Zirak, P; Penzkofer, A; Mathes, T; Hegemann, P

2009-11-09

The wild-type BLUF protein Slr1694 from Synechocystis sp. PCC6803 (BLUF=blue-light sensor using FAD) has flavin adenosine dinucleotide (FAD) as natural cofactor. This light sensor causes positive phototaxis of the marine cyanobacterium. In this study the FAD cofactor of the wild-type Slr1694 was replaced by roseoflavin (RoF) and the roseoflavin derivatives RoFMN and RoFAD during heterologous expression in a riboflavin auxotrophic E. coli strain. An absorption and emission spectroscopic characterization of the cofactor-exchanged-Slr1694 (RoSlr) was carried out both under dark conditions and under illuminated conditions. The behaviour of RoF embedded in RoSlr in aqueous solution at pH 8 is compared with the behaviour of RoF in aqueous solution. The fluorescence of RoF and RoSlr is quenched by photo-induced twisted intra-molecular charge transfer at room temperature with stronger effect for RoF. The fluorescence quenching is diminished at liquid nitrogen temperature. Light exposure of RoSlr causes irreversible conversion of the protein embedded roseoflavins to 8-methylamino-flavins, 8-dimethylamino-lumichrome and 8-methylamino-lumichrome.

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

Science.gov (United States)

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

2018-03-25

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

Effect of culture density on biomass production and light utilization efficiency of Synechocystis sp. PCC 6803.

Science.gov (United States)

Straka, Levi; Rittmann, Bruce E

2018-02-01

The viability of large-scale microalgae cultivation depends on providing optimal growth conditions, for which a key operational parameter is culture density. Using Synechocystis sp. PCC 6803, we conducted a series of fixed-density, steady-state experiments and one batch-growth experiment to investigate the role of culture density on biomass production and light utilization efficiency. In all cases, the fixed-density, steady-state experiments and batch-growth experiment showed good agreement. The highest biomass production rates (260 mg L -1  d -1 ) and efficiency for converting light energy to biomass (0.80 μg (μmol photons) -1 ) occurred together at a culture density near 760 mg L -1 , which approximately corresponded to the lowest culture density where almost all incident light was absorbed. The ratio of OD 680 /OD 735 increased with culture density up to the point of maximum productivity, where it plateaued (at a value of 2.4) for higher culture densities. This change in OD 680 /OD 735 indicates a photoacclimation effect that depended on culture density. Very high culture densities led to a sharp decline in efficiency of biomass production per photons absorbed, likely due to a combination of increased decay relative to growth, metabolic changes due to cell-cell interactions, and photodamage due to mixing between regions with high light intensity and zero light intensity. © 2017 Wiley Periodicals, Inc.

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

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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

CyanoEXpress: A web database for exploration and visualisation of the integrated transcriptome of cyanobacterium Synechocystis sp. PCC6803.

Science.gov (United States)

Hernandez-Prieto, Miguel A; Futschik, Matthias E

2012-01-01

Synechocystis sp. PCC6803 is one of the best studied cyanobacteria and an important model organism for our understanding of photosynthesis. The early availability of its complete genome sequence initiated numerous transcriptome studies, which have generated a wealth of expression data. Analysis of the accumulated data can be a powerful tool to study transcription in a comprehensive manner and to reveal underlying regulatory mechanisms, as well as to annotate genes whose functions are yet unknown. However, use of divergent microarray platforms, as well as distributed data storage make meta-analyses of Synechocystis expression data highly challenging, especially for researchers with limited bioinformatic expertise and resources. To facilitate utilisation of the accumulated expression data for a wider research community, we have developed CyanoEXpress, a web database for interactive exploration and visualisation of transcriptional response patterns in Synechocystis. CyanoEXpress currently comprises expression data for 3073 genes and 178 environmental and genetic perturbations obtained in 31 independent studies. At present, CyanoEXpress constitutes the most comprehensive collection of expression data available for Synechocystis and can be freely accessed. The database is available for free at http://cyanoexpress.sysbiolab.eu.

Roles of xanthophyll carotenoids in protection against photoinhibition and oxidative stress in the cyanobacterium Synechococcus sp. strain PCC 7002.

Science.gov (United States)

Zhu, Yuehui; Graham, Joel E; Ludwig, Marcus; Xiong, Wei; Alvey, Richard M; Shen, Gaozhong; Bryant, Donald A

2010-12-01

Synechococcus sp. strain PCC 7002 is a robust, genetically tractable cyanobacterium that produces six different xanthophyll carotenoids (zeaxanthin, cryptoxanthin, myxoxanthophyll (myxol-2'-fucoside), echinenone, 3'-hydroxyechinenone, and synechoxanthin) and tolerates many environmental stresses, including high light intensities. Targeted mutations were introduced to block the branches of the carotenoid biosynthetic pathway leading to specific xanthophylls, and a mutant lacking all xanthophylls was constructed. Some of the mutants showed severe growth defects at high light intensities, and multi-locus mutants had somewhat lower chlorophyll contents and lower photosystem I levels. The results suggested that xanthophylls, particularly zeaxanthin and echinenone, might play regulatory roles in thylakoid biogenesis. Measurements of reactive oxygen (ROS) and nitrogen (RNS) species in the mutants showed that all xanthophylls participate in preventing ROS/RNS accumulation and that a mutant lacking all xanthophylls accumulated very high levels of ROS/RNS. Results from transcription profiling showed that mRNA levels for most genes encoding the enzymes of carotenogenesis are significantly more abundant after exposure to high light. These studies indicated that all xanthophylls contribute to protection against photo-oxidative stress. Copyright © 2010 Elsevier Inc. All rights reserved.

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. © 2016 American Society of Plant Biologists. All Rights Reserved.

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

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

Science.gov (United States)

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

2015-12-01

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

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

Science.gov (United States)

2009-01-01

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 has occurred. This co

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

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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

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

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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

New Insight into the Cleavage Reaction of Nostoc sp. Strain PCC 7120 Carotenoid Cleavage Dioxygenase in Natural and Nonnatural Carotenoids

Science.gov (United States)

Heo, Jinsol; Kim, Se Hyeuk

2013-01-01

Carotenoid cleavage dioxygenases (CCDs) are enzymes that catalyze the oxidative cleavage of carotenoids at a specific double bond to generate apocarotenoids. In this study, we investigated the activity and substrate preferences of NSC3, a CCD of Nostoc sp. strain PCC 7120, in vivo and in vitro using natural and nonnatural carotenoid structures. NSC3 cleaved β-apo-8′-carotenal at 3 positions, C-13C-14, C-15C-15′, and C-13′C-14′, revealing a unique cleavage pattern. NSC3 cleaves the natural structure of carotenoids 4,4′-diaponeurosporene, 4,4′-diaponeurosporen-4′-al, 4,4′-diaponeurosporen-4′-oic acid, 4,4′-diapotorulene, and 4,4′-diapotorulen-4′-al to generate novel cleavage products (apo-14′-diaponeurosporenal, apo-13′-diaponeurosporenal, apo-10′-diaponeurosporenal, apo-14′-diapotorulenal, and apo-10′-diapotorulenal, respectively). The study of carotenoids with natural or nonnatural structures produced by using synthetic modules could provide information valuable for understanding the cleavage reactions or substrate preferences of other CCDs in vivo and in vitro. PMID:23524669

Colour evaluation of a phycobiliprotein-rich extract obtained from Nostoc PCC9205 in acidic solutions and yogurt.

Science.gov (United States)

de O Moreira, Isabela; Passos, Thaís S; Chiapinni, Claudete; Silveira, Gabrielle K; Souza, Joana C M; Coca-Vellarde, Luis Guillermo; Deliza, Rosires; de Lima Araújo, Kátia G

2012-02-01

Phycobiliproteins are coloured proteins produced by cyanobacteria, which have several applications because of their colour properties. However, there is no available information about the colour stability of phycobiliproteins from Nostoc sp. in food systems. The aim of this work was to study the colour stability of a purple-coloured phycobiliprotein-rich extract from the cyanobacterium Nostoc PCC9205 in acidic solutions and yogurt. Variations of pH for Nostoc PCC9205 extract have shown stability for the L* (lightness) and a* (redness) indexes in the range 1.0-7.0. The b* index (blueness), however, increased at pH values below 4.0, indicating loss of the blue colour. The Nostoc PCC9205 extract was used as colorant in yogurt (pH 4.17) stored for 60 days. Instrumental colour analysis showed no changes for the L* and a* indexes during storage, whereas the b* index changed after 20 days of storage. A multiple comparison test showed colour instability after 20 days of storage. A hedonic scale test performed on the 60th day of storage showed acceptability of the product. The red component of the phycobiliprotein-rich extract from Nostoc PCC9205 presented an improved stability in acidic media and yogurt compared with the blue component of this extract. Copyright © 2011 Society of Chemical Industry.

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

Science.gov (United States)

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

2014-06-30

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

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

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Hiroshi Kiyota

2014-06-01

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

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

Science.gov (United States)

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

2017-12-13

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

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

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Yanan eZhang

2015-05-01

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

Protein (Cyanobacteria): 440680064 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007154859.1 NC_019775 1117:3991 ... 1161:5387 ... 1162:6232 1163:4927 1165:626 272123:626 ... putative addicti...on module antidote protein Anabaena cylindrica PCC 7122 MALTKDFKETVNARIQRDPDFAIVLLDEAISLFLNGELETARLILRNMLNLSHF

CopM is a novel copper-binding protein involved in copper resistance in Synechocystis sp. PCC 6803

Science.gov (United States)

Giner-Lamia, Joaquín; López-Maury, Luis; Florencio, Francisco J

2015-01-01

Copper resistance system in the cyanobacterium Synechocystis sp. PCC 6803 comprises two operons, copMRS and copBAC, which are expressed in response to copper in the media. copBAC codes for a heavy-metal efflux–resistance nodulation and division (HME-RND) system, while copMRS codes for a protein of unknown function, CopM, and a two-component system CopRS, which controls the expression of these two operons. Here, we report that CopM is a periplasmic protein able to bind Cu(I) with high affinity (KD ∼3 × 10−16). Mutants lacking copM showed a sensitive copper phenotype similar to mutants affected in copB, but lower than mutants of the two-component system CopRS, suggesting that CopBAC and CopM constitute two independent resistance mechanisms. Moreover, constitutive expression of copM is able to partially suppress the copper sensitivity of the copR mutant strain, pointing out that CopM per se is able to confer copper resistance. Furthermore, constitutive expression of copM was able to reduce total cellular copper content of the copR mutant to the levels determined in the wild-type (WT) strain. Finally, CopM was localized not only in the periplasm but also in the extracellular space, suggesting that CopM can also prevent copper accumulation probably by direct copper binding outside the cell. PMID:25545960

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

Science.gov (United States)

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

2015-01-01

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

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

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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.

Phylogenetic analysis of the genus Anabaena based on PCR ...

African Journals Online (AJOL)

In this study, ten species of Anabaena were used to test the congruence between the traditional morphological classification system and the present molecular classification system. For morphological classification, strains were categorized into two different groups based on the whether or not the akinetes were directly ...

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

Science.gov (United States)

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

2016-06-01

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

Antibiotic activity of two Anabaena species against four fish ...

African Journals Online (AJOL)

STORAGESEVER

2008-08-04

Aug 4, 2008 ... New antibiotics with high activity and without side effects for human and for .... doses, and n = the total number of used mice. Statistical .... extract of Anabaena variabilis on mice. Dose (mg/kg) ... Tetranychidae). International Conference for Development and the .... Elsevier Scientific, New York. 26. JE Grady,.

[Increasing reductant NADPH content via metabolic engineering of PHB synthesis pathway in Synechocystis sp. PCC 6803].

Science.gov (United States)

Xie, Juan; Zhou, Jie; Zhang, Haifeng; Li, Yin

2011-07-01

Cyanobacteria have become attractive hosts for renewable chemicals production. The low productivity, however, prevents it from industrial application. Reductant NAD(P)H availability is a chief hurdle for the production of reductive metabolites in microbes. To increase NADPH content in Synechocystis sp. PCC 6803, PHB synthase encoding gene phaC and phaE in Synechocystis was inactivated by replacing phaC&E genes with chloromycetin resistance cassette via homologous recombination. PCR analysis showed that mutant S.delta phaC&E with complete genome segregation was generated. The comparison between growth curves of S.wt and S.delta phaC&E indicated the knockout of phaC & phaE genes did not affect obviously the cell growth. Gas chromatography analysis showed that the accumulation of PHB in wild type was about 2.3% of the dry cell weight, whereas no PHB was detected in the mutant S.delta phaC&E. The data indicated that inactivation of PHB synthase gene phaC and phaE interrupted the synthesis of PHB. Further comparative study of wild type and mutant demonstrated that NADPH content in S.delta phaC&E was obviously increased. On the third day, the NADPH content in S.delta phaC&E was up to 1.85 fold higher than that in wild type. These results indicated that deleting PHB synthase gene phaC and phaE not only can block the synthesis of PHB, but also can save NADPH to contribute reductant sink in cyanobacteria. Hence, the engineered cyanobacterial strain S.delta phaC&E, in which carbon flux was redirected and NADPH was increased, will be a potential host strain for chemicals production in cyanobacteria.

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

Science.gov (United States)

Zakar, Tomas; Herman, Eva; Vajravel, Sindhujaa; Kovacs, Laszlo; Knoppová, Jana; Komenda, Josef; Domonkos, Ildiko; Kis, Mihaly; Gombos, Zoltan; Laczko-Dobos, Hajnalka

2017-05-01

Polyunsaturated lipids are important components of photosynthetic membranes. Xanthophylls are the main photoprotective agents, can assist in protection against light stress, and are crucial in the recovery from photoinhibition. We generated the xanthophyll- and polyunsaturated lipid-deficient ROAD mutant of Synechocystis sp. PCC6803 (Synechocystis) in order to study the little-known cooperative effects of lipids and carotenoids (Cars). Electron microscopic investigations confirmed that in the absence of xanthophylls the S-layer of the cellular envelope is missing. In wild-type (WT) cells, as well as the xanthophyll-less (RO), polyunsaturated lipid-less (AD), and the newly constructed ROAD mutants the lipid and Car compositions were determined by MS and HPLC, respectively. We found that, relative to the WT, the lipid composition of the mutants was remodeled and the Car content changed accordingly. In the mutants the ratio of non-bilayer-forming (NBL) to bilayer-forming (BL) lipids was found considerably lower. Xanthophyll to β-carotene ratio increased in the AD mutant. In vitro and in vivo methods demonstrated that saturated, monounsaturated lipids and xanthophylls may stabilize the trimerization of Photosystem I (PSI). Fluorescence induction and oxygen-evolving activity measurements revealed increased light sensitivity of RO cells compared to those of the WT. ROAD showed a robust increase in light susceptibility and reduced recovery capability, especially at moderate low (ML) and moderate high (MH) temperatures, indicating a cooperative effect of xanthophylls and polyunsaturated lipids. We suggest that both lipid unsaturation and xanthophylls are required for providing the proper structure and functioning of the membrane environment that protects against light and temperature stress. Copyright © 2017 Elsevier B.V. All rights reserved.

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

Science.gov (United States)

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

2013-01-14

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

Ethylene Regulates the Physiology of the Cyanobacterium Synechocystis sp. PCC 6803 via an Ethylene Receptor1[OPEN

Science.gov (United States)

2016-01-01

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

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

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

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Ana M Sánchez-Riego

2013-11-01

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

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

Bioselective synthesis of gold nanoparticles from diluted mixed Au, Ir, and Rh ion solution by Anabaena cylindrica

Science.gov (United States)

Rochert, Anna S.; Rösken, Liz M.; Fischer, Christian B.; Schönleber, Andreas; Ecker, Dennis; van Smaalen, Sander; Geimer, Stefan; Wehner, Stefan

2017-11-01

Over the last years, an environmentally friendly and economically efficient way of nanoparticle production has been found in the biosynthesis of metal nanoparticles by bacteria and cyanobacteria. In this study, Anabaena cylindrica, a non-toxic cyanobacterium, is deployed in a diluted ionic aqueous mixture of equal concentrations of gold, iridium, and rhodium, of 0.1 mM each, for the selective biosynthesis of metal nanoparticles (NPs). To analyze the cyanobacterial metal uptake, X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and inductively coupled plasma mass spectrometry (ICP-MS) were applied. Only gold can be found in crystalline and nanoparticle form inside the cells of A. cylindrica, and it is the only metal for which ICP-MS analyses show a rapid decrease of the concentration in the culture medium. A slight decrease of rhodium and none of iridium was observed in the evaluated timeline of 51 h. The average diameter size of the emerging gold nanoparticles increased over the first few days, but is found to be below 10 nm even after more than 2 days. A new evaluation method was used to determine the spatially resolved distribution of the nanoparticles inside the cyanobacterial cells. This new method was also used to analyze TEM images from earlier studies of A. cylindrica and Anabaena sp., both incubated with an overall concentration of 0.8 mM Au3+ to compare the metal uptake. A. cylindrica was found to be highly selective towards the formation of gold nanoparticles in the presence of rhodium and iridium.

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

International Nuclear Information System (INIS)

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

2005-01-01

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

Alkane Biosynthesis Genes in Cyanobacteria and Their Transcriptional Organization

International Nuclear Information System (INIS)

Klähn, Stephan; Baumgartner, Desirée; Pfreundt, Ulrike; Voigt, Karsten; Schön, Verena; Steglich, Claudia; Hess, Wolfgang R.

2014-01-01

In cyanobacteria, alkanes are synthesized from a fatty acyl-ACP by two enzymes, acyl–acyl carrier protein reductase and aldehyde deformylating oxygenase. Despite the great interest in the exploitation for biofuel production, nothing is known about the transcriptional organization of their genes or the physiological function of alkane synthesis. The comparison of 115 microarray datasets indicates the relatively constitutive expression of aar and ado genes. The analysis of 181 available genomes showed that in 90% of the genomes both genes are present, likely indicating their physiological relevance. In 61% of them they cluster together with genes encoding acetyl-CoA carboxyl transferase and a short-chain dehydrogenase, strengthening the link to fatty acid metabolism and in 76% of the genomes they are located in tandem, suggesting constraints on the gene arrangement. However, contrary to the expectations for an operon, we found in Synechocystis sp. PCC 6803 specific promoters for the two genes, sll0208 (ado) and sll0209 (aar), which give rise to monocistronic transcripts. Moreover, the upstream located ado gene is driven by a proximal as well as a second, distal, promoter, from which a third transcript, the ~160 nt sRNA SyR9 is transcribed. Thus, the transcriptional organization of the alkane biosynthesis genes in Synechocystis sp. PCC 6803 is of substantial complexity. We verified all three promoters to function independently from each other and show a similar promoter arrangement also in the more distant Nodularia spumigena, Trichodesmium erythraeum, Anabaena sp. PCC 7120, Prochlorococcus MIT9313, and MED4. The presence of separate regulatory elements and the dominance of monocistronic mRNAs suggest the possible autonomous regulation of ado and aar. The complex transcriptional organization of the alkane synthesis gene cluster has possible metabolic implications and should be considered when manipulating the expression of these genes in cyanobacteria.

Alkane biosynthesis genes in cyanobacteria and their transcriptional organization

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Stephan eKlähn

2014-07-01

Full Text Available In cyanobacteria, alkanes are synthesized from a fatty acyl-ACP by two enzymes, acyl-acyl carrier protein reductase (AAR and aldehyde deformylating oxygenase (ADO. Despite the great interest in the exploitation for biofuel production, nothing is known about the transcriptional organization of their genes or the physiological function of alkane synthesis. The comparison of 115 microarray datasets indicates the relatively constitutive expression of aar and ado genes. The analysis of 181 available genomes showed that in 90% of the genomes both genes are present, likely indicating their physiological relevance. In 61% of them they cluster together with genes encoding acetyl-CoA carboxyl transferase and a short chain dehydrogenase, strengthening the link to fatty acid metabolism and in 76% of the genomes they are located in tandem, suggesting constraints on the gene arrangement. However, contrary to the expectations for an operon, we found in Synechocystis sp. PCC 6803 specific promoters for the two genes, sll0208 (ado and sll0209 (aar, that give rise to monocistronic transcripts. Moreover, the upstream located ado gene is driven by a proximal as well as a second, distal, promoter, from which a third transcript, the ~160 nt sRNA SyR9 is transcribed. Thus, the transcriptional organization of the alkane biosynthesis genes in Synechocystis sp. PCC 6803 is of substantial complexity. We verified all three promoters to function independently from each other and show a similar promoter arrangement also in the more distant Nodularia spumigena, Trichodesmium erythraeum, Anabaena sp. PCC 7120, Prochlorococcus MIT9313 and MED4. The presence of separate regulatory elements and the dominance of monocistronic mRNAs suggest the possible autonomous regulation of ado and aar. The complex transcriptional organization of the alkane synthesis gene cluster has possible metabolic implications and should be considered when manipulating the expression of these genes in

Alkane Biosynthesis Genes in Cyanobacteria and Their Transcriptional Organization

Energy Technology Data Exchange (ETDEWEB)

Klähn, Stephan; Baumgartner, Desirée; Pfreundt, Ulrike; Voigt, Karsten; Schön, Verena; Steglich, Claudia; Hess, Wolfgang R., E-mail: wolfgang.hess@biologie.uni-freiburg.de [Genetics and Experimental Bioinformatics, Institute of Biology 3, Faculty of Biology, University of Freiburg, Freiburg (Germany)

2014-07-14

In cyanobacteria, alkanes are synthesized from a fatty acyl-ACP by two enzymes, acyl–acyl carrier protein reductase and aldehyde deformylating oxygenase. Despite the great interest in the exploitation for biofuel production, nothing is known about the transcriptional organization of their genes or the physiological function of alkane synthesis. The comparison of 115 microarray datasets indicates the relatively constitutive expression of aar and ado genes. The analysis of 181 available genomes showed that in 90% of the genomes both genes are present, likely indicating their physiological relevance. In 61% of them they cluster together with genes encoding acetyl-CoA carboxyl transferase and a short-chain dehydrogenase, strengthening the link to fatty acid metabolism and in 76% of the genomes they are located in tandem, suggesting constraints on the gene arrangement. However, contrary to the expectations for an operon, we found in Synechocystis sp. PCC 6803 specific promoters for the two genes, sll0208 (ado) and sll0209 (aar), which give rise to monocistronic transcripts. Moreover, the upstream located ado gene is driven by a proximal as well as a second, distal, promoter, from which a third transcript, the ~160 nt sRNA SyR9 is transcribed. Thus, the transcriptional organization of the alkane biosynthesis genes in Synechocystis sp. PCC 6803 is of substantial complexity. We verified all three promoters to function independently from each other and show a similar promoter arrangement also in the more distant Nodularia spumigena, Trichodesmium erythraeum, Anabaena sp. PCC 7120, Prochlorococcus MIT9313, and MED4. The presence of separate regulatory elements and the dominance of monocistronic mRNAs suggest the possible autonomous regulation of ado and aar. The complex transcriptional organization of the alkane synthesis gene cluster has possible metabolic implications and should be considered when manipulating the expression of these genes in cyanobacteria.

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

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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.

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

Science.gov (United States)

Červený, Jan; Sinetova, Maria A; Zavřel, Tomáš; Los, Dmitry A

2015-03-02

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.

Phylogenetic analysis of the genus Anabaena based on PCR ...

African Journals Online (AJOL)

STORAGESEVER

2009-12-15

Dec 15, 2009 ... LTRR2. 5'- CTA TCA GGG ATT GAA AG-3'. Rasmussen and. Svenning, 1998 on a 1% agarose gel containing 0.5 X TBE (Tris Borate-EDTA) and. 0.5 µg/ml ethidium bromide. Data analysis. Fingerprints generated from different Anabaena species were compared and all bands were scored. The presence or ...

Management Approaches for Water Quality Enhancement at Whitney Point and East Sidney Lake, New York

Science.gov (United States)

1990-08-01

flos- aguae Anabaena sp. (colonial blue-greens) 8-16-88 Aphanizomenon flos- aguae Anabaena planctonica Coccoid sp. (colonial blue-greens...Goelosphaeriui sp. Microcystis aerug~inosa Comphosphaeria sp. 9-9-88 Aphanizomenon flos- aguae Oscillatoria sp. Melosira spp. Table 9 Dominant Phytoplankton Species...study (Kennedy et al. 1988). Sampling period was initiated in early April, 1988 and completed in early September, 1988. In situ variables, measured at

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

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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.

Production of squalene in Synechocystis sp. PCC 6803.

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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

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

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Qian Fei

2018-03-01

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

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

Science.gov (United States)

Nguyen, Binh Thanh

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

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

Identification of OmpR-family response regulators interacting with thioredoxin in the Cyanobacterium Synechocystis sp. PCC 6803.

Directory of Open Access Journals (Sweden)

Taro Kadowaki

Full Text Available The redox state of the photosynthetic electron transport chain is known to act as a signal to regulate the transcription of key genes involved in the acclimation responses to environmental changes. We hypothesized that the protein thioredoxin (Trx acts as a mediator connecting the redox state of the photosynthetic electron transport chain and transcriptional regulation, and established a screening system to identify transcription factors (TFs that interact with Trx. His-tagged TFs and S-tagged mutated form of Trx, TrxMC35S, whose active site cysteine 35 was substituted with serine to trap the target interacting protein, were co-expressed in E. coli cells and Trx-TF complexes were detected by immuno-blotting analysis. We examined the interaction between Trx and ten OmpR family TFs encoded in the chromosome of the cyanobacterium Synechocystis sp. PCC 6803 (S.6803. Although there is a highly conserved cysteine residue in the receiver domain of all OmpR family TFs, only three, RpaA (Slr0115, RpaB (Slr0947 and ManR (Slr1837, were identified as putative Trx targets [corrected].The recombinant forms of wild-type TrxM, RpaA, RpaB and ManR proteins from S.6803 were purified following over-expression in E. coli and their interaction was further assessed by monitoring changes in the number of cysteine residues with free thiol groups. An increase in the number of free thiols was observed after incubation of the oxidized TFs with Trx, indicating the reduction of cysteine residues as a consequence of interaction with Trx. Our results suggest, for the first time, the possible regulation of OmpR family TFs through the supply of reducing equivalents from Trx, as well as through the phospho-transfer from its cognate sensor histidine kinase.

GC/MS analysis of piperidinocyclohexanecarbonitrile (PCC) smoking products

International Nuclear Information System (INIS)

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

1986-01-01

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 3 H-piperidino- 14 C-cyano-PCC (synthesized in the lab and recrystallized twice, m.p. 67 0 C) and burned under conditions which simulated smoking. Mainstream smoke was passed through glass wool filters and H 2 SO 4 and NaOH traps. Tritium and 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 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%)

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

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Monshupanee, T; Incharoensakdi, A

2014-04-01

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

The cyanobiont in an Azolla fern is neither Anabaena nor Nostoc.

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Baker, Judith A; Entsch, Barrie; McKay, David B

2003-12-05

The cyanobacterial symbionts in the fern Azolla have generally been ascribed to either the Anabaena or Nostoc genera. By using comparisons of the sequences of the phycocyanin intergenic spacer and a fragment of the 16S rRNA, we found that the cyanobiont from an Azolla belongs to neither of these genera.

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

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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. Copyright © 2014. Published by Elsevier Inc.

Algal Production of Extra- and Intra-Cellular Polysaccharides as an Adaptive Response to the Toxin Crude Extract of Microcystis Aeruginosa

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Mostafa Mohamed El-Sheekh

2012-11-01

Full Text Available This is an investigation concerned with studying the possible adaptive response of four different unicellular algae, Anabaena PCC 7120, Oscillatoria angustissima, Scendesmus obliquus and Chlorella vulgaris, to the toxin of Microcystis aeruginosa (Kützing. Theeffects of four different concentrations, 25, 50, 100 and 200 μg mL-1 of microcystins crude extract of M. aeruginosa, on both intra and extra-cellular polysaccharide levels, in log phase,of the four tested algae were studied. The obtained results showed differential increase in the production levels for both intra and extra-cellular polysaccharides by the tested algae,compared with the control. S. obliquus and C. vulgaris showed a resistance to crude toxinhigher than Anabaena PCC 7120 and O. angustissima. The highly production of polysaccharides by green algal species under this toxic stress indicated the involvement of these polysaccharides in protecting the algal cells against toxic species and, reflect thebiological behavior of particular algal species to the environmental stresses.

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

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Anita Loeschcke

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

Structure-Function, Stability, and Chemical Modification of the Cyanobacterial Cytochrome b6f Complex from Nostoc sp. PCC 7120*

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Baniulis, Danas; Yamashita, Eiki; Whitelegge, Julian P.; Zatsman, Anna I.; Hendrich, Michael P.; Hasan, S. Saif; Ryan, Christopher M.; Cramer, William A.

2009-01-01

The crystal structure of the cyanobacterial cytochrome b6f complex has previously been solved to 3.0-Å resolution using the thermophilic Mastigocladus laminosus whose genome has not been sequenced. Several unicellular cyanobacteria, whose genomes have been sequenced and are tractable for mutagenesis, do not yield b6f complex in an intact dimeric state with significant electron transport activity. The genome of Nostoc sp. PCC 7120 has been sequenced and is closer phylogenetically to M. laminosus than are unicellular cyanobacteria. The amino acid sequences of the large core subunits and four small peripheral subunits of Nostoc are 88 and 80% identical to those in the M. laminosus b6f complex. Purified b6f complex from Nostoc has a stable dimeric structure, eight subunits with masses similar to those of M. laminosus, and comparable electron transport activity. The crystal structure of the native b6f complex, determined to a resolution of 3.0Å (PDB id: 2ZT9), is almost identical to that of M. laminosus. Two unique aspects of the Nostoc complex are: (i) a dominant conformation of heme bp that is rotated 180° about the α- and γ-meso carbon axis relative to the orientation in the M. laminosus complex and (ii) acetylation of the Rieske iron-sulfur protein (PetC) at the N terminus, a post-translational modification unprecedented in cyanobacterial membrane and electron transport proteins, and in polypeptides of cytochrome bc complexes from any source. The high spin electronic character of the unique heme cn is similar to that previously found in the b6f complex from other sources. PMID:19189962

Finding novel relationships with integrated gene-gene association network analysis of Synechocystis sp. PCC 6803 using species-independent text-mining.

Science.gov (United States)

Kreula, Sanna M; Kaewphan, Suwisa; Ginter, Filip; Jones, Patrik R

2018-01-01

The increasing move towards open access full-text scientific literature enhances our ability to utilize advanced text-mining methods to construct information-rich networks that no human will be able to grasp simply from 'reading the literature'. The utility of text-mining for well-studied species is obvious though the utility for less studied species, or those with no prior track-record at all, is not clear. Here we present a concept for how advanced text-mining can be used to create information-rich networks even for less well studied species and apply it to generate an open-access gene-gene association network resource for Synechocystis sp. PCC 6803, a representative model organism for cyanobacteria and first case-study for the methodology. By merging the text-mining network with networks generated from species-specific experimental data, network integration was used to enhance the accuracy of predicting novel interactions that are biologically relevant. A rule-based algorithm (filter) was constructed in order to automate the search for novel candidate genes with a high degree of likely association to known target genes by (1) ignoring established relationships from the existing literature, as they are already 'known', and (2) demanding multiple independent evidences for every novel and potentially relevant relationship. Using selected case studies, we demonstrate the utility of the network resource and filter to ( i ) discover novel candidate associations between different genes or proteins in the network, and ( ii ) rapidly evaluate the potential role of any one particular gene or protein. The full network is provided as an open-source resource.

Uptake and utilization of sulfonic acids in the cyanobacterial strains Anabaena variabilis and Plectonema 73110

International Nuclear Information System (INIS)

Biedlingmaier, S.; Schmidt, A.

1987-01-01

Growth of several cyanobacteria was examined on ethane sulfonate and taurine as only sulfur source. Comparing two strains with differential utilization of sulfonic acids (Anabaena variabilis and Synechococcus 6301) demonstrated that actual growth was coupled to the presence of an active sulfonate transport system due to species specific properties and nutritional conditions. Sulfonate uptake in Anabaena variabilis was characterized by a pH optimum of 6.5, a structural specificity for sulfonates, missing Na + dependence, and phosphate stimulation. Radiolabeled ethane sulfonate and taurine was metabolized to products of normal sulfur metabolism. Also considerable amounts of 35 S-labeled volatiles (mercaptanes and sulfide) could be detected, suggesting a degradation mechanism via reduction to mercaptanes and cleavage of the C-S bond. (orig.)

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

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

2017-06-01

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

Photophosphorylation capacity of stable spheroplast preparations of anabaena.

Science.gov (United States)

Spiller, H

1980-09-01

Spheroplasts from Anabaena 7119 (formerly designated Nostoc muscorum) were prepared in the presence of serum albumin in 0.5 molar sucrose. Electron transport and photophosphorylation were preserved (> 70% of the maximum rate for 1 week). The pH profile of electron transport and photophosphorylation in the reactions H(2)O --> NADP, H(2)O --> methyl viologen, and H(2)O --> ferricyanide shows that uncoupling by ammonia is small throughout and increases slightly with higher pH. ADP + Pi increased NADP reduction from H(2)O by 2.5-fold. The ratios of ATP formed per electron pair transported ranged from 0.9 to 1.5. Effects of catalase and superoxide dismutase on the overall O(2) balance implicate pseudocyclic electron transport and phosphorylation. The quenching of 9-aminoacridine fluorescence indicates the formation of a Delta pH from 2 to 2.6 during illumination. This pH gradient is abolished by uncouplers; however, complete uncoupling is achieved only by 3-chlorocarbonyl cyanide phenylhydrazone or valinomycin + NH(4) (+). In the presence of NH(4) (+) alone, the membrane potential may act as the driving force for photophosphorylation.Increasing amounts of bovine serum albumin protected phosphorylation from uncoupling by silicomolybdic acid. 3-(3,4-Dichlorophenyl)-1, 1-dimethylurea-insensitive water oxidation by silicomolybdic acid provides evidence that the site for 3-(3,4-dichlorophenyl)-1, 1-dimethylurea action is on the acceptor and not donor side of photosystem II in the procaryote Anabaena. It is concluded that stable spheroplasts retain coupled electron transport approaching in vivo rates.

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

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

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

2015-02-06

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

Drug-induced premature chromosome condensation (PCC) protocols: cytogenetic approaches in mitotic chromosome and interphase chromatin.

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Gotoh, Eisuke

2015-01-01

Chromosome analysis is a fundamental technique which is used in wide areas of cytogenetic study including karyotyping species, hereditary diseases diagnosis, or chromosome biology study. Chromosomes are usually prepared from mitotic cells arrested by colcemid block protocol. However, obtaining mitotic chromosomes is often hampered under several circumstances. As a result, cytogenetic analysis will be sometimes difficult or even impossible in such cases. Premature chromosome condensation (PCC) (see Note 1) is an alternative method that has proved to be a unique and useful way in chromosome analysis. Former, PCC has been achieved following cell fusion method (cell-fusion PCC) mediated either by fusogenic viruses (e.g., Sendai virus) or cell fusion chemicals (e.g., polyethylene glycol), but the cell fusion PCC has several drawbacks. The novel drug-induced PCC using protein phosphatase inhibitors was introduced about 20 years ago. This method is much simpler and easier even than the conventional mitotic chromosome preparation protocol use with colcemid block and furthermore obtained PCC index (equivalent to mitotic index for metaphase chromosome) is usually much higher than colcemid block method. Moreover, this method allows the interphase chromatin to be condensed to visualize like mitotic chromosomes. Therefore drug-induced PCC has opened the way for chromosome analysis not only in metaphase chromosomes but also in interphase chromatin. The drug-induced PCC has thus proven the usefulness in cytogenetics and other cell biology fields. For this second edition version, updated modifications/changes are supplemented in Subheadings 2, 3, and 4, and a new section describing the application of PCC in chromosome science fields is added with citation of updated references.

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

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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.

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

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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.

Upstream factors affecting Tualatin River algae—Tracking the 2008 Anabaena algae bloom to Wapato Lake, Oregon

Science.gov (United States)

Rounds, Stewart A.; Carpenter, Kurt D.; Fesler, Kristel J.; Dorsey, Jessica L.

2015-12-17

Significant Findings A large bloom that included floating mats of the blue-green algae Anabaena flos-aquae occurred in the lower 20 miles of the Tualatin River in northwestern Oregon between July 7 and July 17, 2008.

TetR Family Transcriptional Regulator PccD Negatively Controls Propionyl Coenzyme A Assimilation in Saccharopolyspora erythraea.

Science.gov (United States)

Xu, Zhen; Wang, Miaomiao; Ye, Bang-Ce

2017-10-15

Propanol stimulates erythromycin biosynthesis by increasing the supply of propionyl coenzyme A (propionyl-CoA), a starter unit of erythromycin production in Saccharopolyspora erythraea Propionyl-CoA is assimilated via propionyl-CoA carboxylase to methylmalonyl-CoA, an extender unit of erythromycin. We found that the addition of n -propanol or propionate caused a 4- to 16-fold increase in the transcriptional levels of the SACE_3398-3400 locus encoding propionyl-CoA carboxylase, a key enzyme in propionate metabolism. The regulator PccD was proved to be directly involved in the transcription regulation of the SACE_3398-3400 locus by EMSA and DNase I footprint analysis. The transcriptional levels of SACE_3398-3400 were upregulated 15- to 37-fold in the pccD gene deletion strain (Δ pccD ) and downregulated 3-fold in the pccD overexpression strain (WT/pIB- pccD ), indicating that PccD was a negative transcriptional regulator of SACE_3398-3400. The Δ pccD strain has a higher growth rate than that of the wild-type strain (WT) on Evans medium with propionate as the sole carbon source, whereas the growth of the WT/pIB- pccD strain was repressed. As a possible metabolite of propionate metabolism, methylmalonic acid was identified as an effector molecule of PccD and repressed its regulatory activity. A higher level of erythromycin in the Δ pccD strain was observed compared with that in the wild-type strain. Our study reveals a regulatory mechanism in propionate metabolism and suggests new possibilities for designing metabolic engineering to increase erythromycin yield. IMPORTANCE Our work has identified the novel regulator PccD that controls the expression of the gene for propionyl-CoA carboxylase, a key enzyme in propionyl-CoA assimilation in S. erythraea PccD represses the generation of methylmalonyl-CoA through carboxylation of propionyl-CoA and reveals an effect on biosynthesis of erythromycin. This finding provides novel insight into propionyl-CoA assimilation, and

First report of an Anabaena Bory strain containing microcystin-LR in a freshwater body in Africa

CSIR Research Space (South Africa)

Oberholster, Paul J

2015-03-11

Full Text Available algae belonged to the genus Anabaena, a family of filamentous cyanobacteria known to produce cyanotoxins such as anatoxin-a, harmful to humans and the aquatic foodweb. The specimens isolated lacked the characteristic akinetes and/or heterocysts...

Evaluating and optimizing recycled concrete fines in PCC mixtures containing supplementary cementitious materials.

Science.gov (United States)

2010-08-01

Portland cement concrete (PCC) is used throughout transportation infrastructure, for roads as well as bridges : and other structures. One of the most effective ways of making PCC more green is to replace a portion of the : portland cement (the ...

Factors Associated with Parental Satisfaction with a Pediatric Crisis Clinic (PCC).

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Lee, Jonathan; Korczak, Daphne

2014-05-01

Little is known about parental satisfaction with pediatric crisis clinics (PCCs) that provide a single consultation to families in need of urgent psychiatric care. Parental satisfaction may improve long-term adherence to physician recommendations. To explore parental satisfaction with a PCC. Parental satisfaction was ascertained by a structured telephone interview following crisis consultation at the PCC of an academic, tertiary care centre. Parents of 71% (n = 124) of 174 pediatric patients seen in the PCC from 2007-2008 participated in the post-consultation interview. The majority of parents stated they were either somewhat satisfied (49/122, 40.2%) or very satisfied (49/122, 40.2%) with the PCC. Parental satisfaction correlated with time between referral and consultation (p<0.05), the degree to which parents felt listened to by the consultant (p<0.01), the amount of psychoeducation parents felt they received (p<0.01), and appointment length (p<0.001). Parents were satisfied overall with an urgent care service model. Satisfaction was correlated with the time between referral and consultation, degree to which they felt their consultant had listened to them, and the amount of information they received at the consultation's conclusion.

Production of nutritionally-deficient mutants of the axenic blue-green alga Anabaena flos-aquae NRC-44-1 by ultraviolet irradiation

Energy Technology Data Exchange (ETDEWEB)

Kumar, H D; Gorham, P R

1975-01-01

Anabaena flos-aquae NRC-44-1 is a freshwater nitrogen fixing blue-green alga of some ecological significance because of its toxicity. In axenic culture and possibly also in nature, the alga is highly susceptible to lysis at certain stages of its growth. Nothing is known about genetic phenomena governing toxin production, nitrogen fixation or other characteristics of this organism, mainly because of unavailability of mutant strains that could be utilized in genetic experiments. With the object of overcoming this obstacle to the eventual study of genetics of Anabaena flos-aquae, attempts were made to produce and isolate nutritionally-deficient mutants of this species.

HupW Protease Specifically Required for Processing of the Catalytic Subunit of the Uptake Hydrogenase in the Cyanobacterium Nostoc sp. Strain PCC 7120

Science.gov (United States)

Lindberg, Pia; Devine, Ellenor; Stensjö, Karin

2012-01-01

The maturation process of [NiFe] hydrogenases includes a proteolytic cleavage of the large subunit. We constructed a mutant of Nostoc strain PCC 7120 in which hupW, encoding a putative hydrogenase-specific protease, is inactivated. Our results indicate that the protein product of hupW selectively cleaves the uptake hydrogenase in this cyanobacterium. PMID:22020512

Heterocyst placement strategies to maximize the growth of cyanobacterial filaments

International Nuclear Information System (INIS)

Brown, Aidan I; Rutenberg, Andrew D

2012-01-01

Under conditions of limited fixed-nitrogen, some filamentous cyanobacteria develop a regular pattern of heterocyst cells that fix nitrogen for the remaining vegetative cells. We examine three different heterocyst placement strategies by quantitatively modelling filament growth while varying both external fixed-nitrogen and leakage from the filament. We find that there is an optimum heterocyst frequency which maximizes the growth rate of the filament; the optimum frequency decreases as the external fixed-nitrogen concentration increases but increases as the leakage increases. In the presence of leakage, filaments implementing a local heterocyst placement strategy grow significantly faster than filaments implementing random heterocyst placement strategies. With no extracellular fixed-nitrogen, consistent with recent experimental studies of Anabaena sp. PCC 7120, the modelled heterocyst spacing distribution using our local heterocyst placement strategy is qualitatively similar to experimentally observed patterns. As external fixed-nitrogen is increased, the spacing distribution for our local placement strategy retains the same shape, while the average spacing between heterocysts continuously increases. (paper)

Biochemical Validation of the Glyoxylate Cycle in the Cyanobacterium Chlorogloeopsis fritschii Strain PCC 9212.

Science.gov (United States)

Zhang, Shuyi; Bryant, Donald A

2015-05-29

Cyanobacteria are important photoautotrophic bacteria with extensive but variable metabolic capacities. The existence of the glyoxylate cycle, a variant of the TCA cycle, is still poorly documented in cyanobacteria. Previous studies reported the activities of isocitrate lyase and malate synthase, the key enzymes of the glyoxylate cycle in some cyanobacteria, but other studies concluded that these enzymes are missing. In this study the genes encoding isocitrate lyase and malate synthase from Chlorogloeopsis fritschii PCC 9212 were identified, and the recombinant enzymes were biochemically characterized. Consistent with the presence of the enzymes of the glyoxylate cycle, C. fritschii could assimilate acetate under both light and dark growth conditions. Transcript abundances for isocitrate lyase and malate synthase increased, and C. fritschii grew faster, when the growth medium was supplemented with acetate. Adding acetate to the growth medium also increased the yield of poly-3-hydroxybutyrate. When the genes encoding isocitrate lyase and malate synthase were expressed in Synechococcus sp. PCC 7002, the acetate assimilation capacity of the resulting strain was greater than that of wild type. Database searches showed that the genes for the glyoxylate cycle exist in only a few other cyanobacteria, all of which are able to fix nitrogen. This study demonstrates that the glyoxylate cycle exists in a few cyanobacteria, and that this pathway plays an important role in the assimilation of acetate for growth in one of those organisms. The glyoxylate cycle might play a role in coordinating carbon and nitrogen metabolism under conditions of nitrogen fixation. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

NMSBA: Aken Technologies Final Report: Toxicity Testing of Liquidoff

Energy Technology Data Exchange (ETDEWEB)

Ruffing, Anne [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jensen, Travis [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Strickland, Lucas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-02-01

To determine the effect of Liquidoff on bacteria, three bacterial strains were tested: Escherichia coli DH5α, Synechococcus sp. PCC 7002, and Synechococcus elongatus PCC 7942. E. coli DH5α is a Gram-negative, aerobic bacterium that is often found in normal gut flora and is commonly used the laboratory due to its fast growth rate. Synechococcus sp. PCC 7002 and S. elongatus PCC 7942 are Gram-negative, aquatic, autophototrophic cyanobacteria. Synechococcus sp. PCC 7002 is a marine cyanobacterium isolated from ‘fish pens’ on Magueyes Island, Puerto Rico in 1962, while S. elongatus PCC 7942 is a freshwater cyanobacterium. It should be noted that no Gram-positive bacterium was tested in this study.

Evaluation of the MIT-Scan-T2 for non-destructive PCC pavement thickness determination.

Science.gov (United States)

2008-07-01

The MIT-Scan-T2 device is marketed as a non-destructive way to determine pavement thickness on both : HMA and PCC pavements. PCC pavement thickness determination is an important incentivedisincentive : measurement for the Iowa DOT and contractors. Th...

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

Science.gov (United States)

van der Woude, Aniek D; Perez Gallego, Ruth; Vreugdenhil, Angie; Puthan Veetil, Vinod; Chroumpi, Tania; Hellingwerf, Klaas J

2016-04-08

Erythritol is a polyol that is used in the food and beverage industry. Due to its non-caloric and non-cariogenic properties, the popularity of this sweetener is increasing. Large scale production of erythritol is currently based on conversion of glucose by selected fungi. In this study, we describe a biotechnological process to produce erythritol from light and CO2, using engineered Synechocystis sp. PCC6803. By functionally expressing codon-optimized genes encoding the erythrose-4-phosphate phosphatase TM1254 and the erythrose reductase Gcy1p, or GLD1, this cyanobacterium can directly convert the Calvin cycle intermediate erythrose-4-phosphate into erythritol via a two-step process and release the polyol sugar in the extracellular medium. Further modifications targeted enzyme expression and pathway intermediates. After several optimization steps, the best strain, SEP024, produced up to 2.1 mM (256 mg/l) erythritol, excreted in the medium.

Removal of Anabaena spiroides by potassium permanganate pre-oxidation: effect on photosynthetic capacity and molecular weight distribution.

Science.gov (United States)

Qiao, Junlian; Zhang, Xiaodong; Lv, Liping

2017-11-01

Bench scale tests were conducted to investigate the effect of potassium permanganate pre-oxidation on the photosynthetic activity and molecular weight distribution of Anabaena spiroides. Different concentrations of potassium permanganate were added into the suspension of Anabaena spiroides, one of the dominant algae in water bloom, and after pre-oxidation of permanganate for 1 h, the results show that the removal rate significantly increases by 33.99~36.35% compared to direct coagulation. Then, the algal characteristics, including photosynthetic ability, the changes in extracellular organic matter three-dimensional fluorescence, and the distribution of molecular weight were conducted and the results show that along with increasing concentration of potassium permanganate, the photosynthetic ability of algae decreases, more extracellular organic matter is secreted, and large molecular weight matter (humic-like and fulvic-like substances) are generated. Therefore, this study demonstrates that potassium permanganate could be used in addressing the algae-rich water.

Hydrogen production by several cyanobacteria

Energy Technology Data Exchange (ETDEWEB)

Kumar, Dhruv; Kumar, H.D. (Banaras Hindu Univ., Varanasi (India). Dept. of Botany)

1992-11-01

Twenty species belonging to eleven genera of nitrogen-fixing and non-nitrogen-fixing cyanobacteria were screened for production of hydrogen. Only one species each of Nostoc and Anabaena showed light-and nitrogenase-dependent aerobic hydrogen production. The highest rate of aerobic hydrogen production was recorded in Anabaena sp. strain CA. When incubated anaerobically under 99% Ar + 1% CO[sub 2], all the tested strains produced hydrogen. Nickel supplementation completely abolished hydrogen production both under aerobic and anaerobic conditions, except in Anabaena sp. strain CA, where only the rate of production was decreased. Species of Plectonema, Oscillatoria and Spirulina showed methyl viologen-dependent (hydrogenase-dependent) hydrogen production. Other physiological activities were also studied with a view to selecting a suitable organism for large-scale production of hydrogen. (author)

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.

Determination of coefficient of thermal expansion effects on Louisiana's PCC pavement design : technical summary report.

Science.gov (United States)

2011-12-01

The coefficient of thermal expansion (CTE) has been widely considered as a fundamental property of : Portland cement concrete (PCC) pavement but has never played an important role in the thickness design : procedure for PCC pavement until recently. I...

NADPH-Thioredoxin Reductase C Mediates the Response to Oxidative Stress and Thermotolerance in the Cyanobacterium Anabaena sp PCC7120

NARCIS (Netherlands)

Sanchez-Riego, Ana M.; Mata-Cabana, Alejandro; Galmozzi, CarlaV.; Florencio, Francisco J.

2016-01-01

NADPH-thioredoxin reductase C (NTRC) is a bimodular enzyme composed of an NADPH-thioredoxin reductase and a thiioredoxin domain extension in the same protein. In plants, NTRC has been described to be involved in the protection of the chloroplast against oxidative stress damage through reduction of

Protein (Cyanobacteria): 414076585 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available pothetical protein ANA_C11310 Anabaena sp. 90 MSVGAKHLEDELSVIAKNSSPNASPVQLLVGGKHLEDKLSVIAKNSSPNASPVQLSVGAKHLEDKLSVIAKNSSPNASPVQLSVVICPENNPKEQIICAVICGVEEKSNEITAIPELIKVLDMTGCLYSTHLNYLI

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)

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)

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

International Nuclear Information System (INIS)

Lamadrid B, A.I.; Garcia L, O.; Delbos, M.; Voisin, P.; Roy, L.

2006-01-01

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)

Offshore distribution patterns of the cyanobacterium Trichodesmium erythraeum ehrenberg and associated phyto- and bacterioplankton in the southern Atlantic coast (Paraná, Brazil

Directory of Open Access Journals (Sweden)

Siqueira Adriana

2006-01-01

Full Text Available Studies were carried out on Thrichodesmium erythraeum occurring on the inner shelf in the state of Paraná, Brazil. Temperature, salinity, rainfall, wind velocity, total bacteria, bacterial biomass, chlorophyll-a, phytoplankton, Anabaena sp., Merismopedia sp. and T. erythraeum densities were measured in surface water. Centric and pennate diatoms, Anabaena sp. and Merismopedia sp. were most abundant at 15 m isobath, while dinoflagellate abundance was relatively constant among stations. Similarly, total bacterial densities were relatively homogeneous throughout the sampling area, suggesting that blooms of T. erythraeum were not yet in the senescent phase. Results showed that T. erythraeum was capable of surviving in relatively inhospitable environmental conditions, due to its ability to fix nitrogen and to photosynthesis at high light intensities.

Evaluation of MIT-SCAN-T2 for Thickness Quality Control for PCC and HMA Pavements

Science.gov (United States)

2018-02-01

Thickness is currently a pay item for PCC pavements and a quality control item for both PCC and HMA pavements. A change in pavement thickness of 0.5 in. can result in a change of multiple years of service. Current thickness measurements are performed...

UV-inducible DNA repair in the cyanobacteria Anabaena spp

International Nuclear Information System (INIS)

Levine, E.; Thiel, T.

1987-01-01

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

Disruption of the ndhF1 gene affects Chl fluorescence through state transition in the Cyanobacterium Synechocystis sp. PCC 6803, resulting in apparent high efficiency of photosynthesis.

Science.gov (United States)

Ogawa, Takako; Harada, Tetsuyuki; Ozaki, Hiroshi; Sonoike, Kintake

2013-07-01

In Synechocystis sp. PCC 6803, the disruption of the ndhF1 gene (slr0844), which encodes a subunit of one of the NDH-1 complexes (NDH-1L complex) serving for respiratory electron transfer, causes the largest change in Chl fluorescence induction kinetics among the kinetics of 750 disruptants searched in the Fluorome, the cyanobacterial Chl fluorescence database. The cause of the explicit phenotype of the ndhF1 disruptant was examined by measurements of the photosynthetic rate, Chl fluorescence and state transition. The results demonstrate that the defects in respiratory electron transfer obviously have great impact on Chl fluorescence in cyanobacteria. The inactivation of NDH-1L complexes involving electron transfer from NDH-1 to plastoquinone (PQ) would result in the oxidation of the PQ pool, leading to the transition to State 1, where the yield of Chl fluorescence is high. Apparently, respiration, although its rate is far lower than that of photosynthesis, could affect Chl fluorescence through the state transition as leverage. The disruption of the ndhF1 gene caused lower oxygen-evolving activity but the estimated electron transport rate from Chl fluorescence measurements was faster in the mutant than in the wild-type cells. The discrepancy could be ascribed to the decreased level of non-photochemical quenching due to state transition. One must be cautious when using the Chl fluorescence parameter to estimate photosynthesis in mutants defective in state transition.

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

Energy Technology Data Exchange (ETDEWEB)

Lamadrid Boada, Ana I; Garcia Lima, Omar [Centro de Proteccion e Higiene de las Radiaciones (CPHR), La Habana (Cuba); Delbos, Martine; Voisin, Philipe; Roy, Laurence [Institut de Radioprotection et de Surete Nucleaire, Fontenay-aux-Roses (France)

2008-07-01

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 lymphocytes 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 G1 G2 and M stages were analyzed. The results were fitted to a lineal quadratic model in Gamma irradiation and showed saturation starting from 20 Gy. 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)

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

International Nuclear Information System (INIS)

Lamadrid Boada, Ana I.; Garcia Lima, Omar; Delbos, Martine; Voisin, Philipe; Roy, Laurence

2008-01-01

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 lymphocytes 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 G1 G2 and M stages were analyzed. The results were fitted to a lineal quadratic model in Gamma irradiation and showed saturation starting from 20 Gy. 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)

Effect of Hydraulic Activity on Crystallization of Precipitated Calcium Carbonate (PCC) for Eco-Friendly Paper

Science.gov (United States)

Kim, Jung-Ah; Han, Gi-Chun; Lim, Mihee; You, Kwang-Suk; Ryu, Miyoung; Ahn, Ji-Whan; Fujita, Toyohisa; Kim, Hwan

2009-01-01

Wt% of aragonite, a CaCO3 polymorph, increased with higher hydraulic activity (°C) of limestone in precipitated calcium carbonate (PCC) from the lime-soda process (Ca(OH)2-NaOH-Na2CO3). Only calcite, the most stable polymorph, was crystallized at hydraulic activity under 10 °C, whereas aragonite also started to crystallize over 10 °C. The crystallization of PCC is more dependent on the hydraulic activity of limestone than CaO content, a factor commonly used to classify limestone ores according to quality. The results could be effectively applied to the determination of polymorphs in synthetic PCC for eco-friendly paper manufacture. PMID:20087470

Effect of water curing duration on strength behaviour of portland composite cement (PCC) mortar

Science.gov (United States)

Caronge, M. A.; Tjaronge, M. W.; Hamada, H.; Irmawaty, R.

2017-11-01

Cement manufacturing of Indonesia has been introduced Portland Composite Cement (PCC) to minimize the rising production cost of cement which contains 80% clinker and 20% mineral admixture. A proper curing is very important when the cement contains mineral admixture materials. This paper reports the results of an experimental study conducted to evaluate the effect of water curing duration on strength behaviour of PCC mortar. Mortar specimens with water to cement ratio of (W/C) 0.5 were casted. Compressive strength, flexural strength and concrete resistance were tested at 7, 28 and 91 days cured water. The results indicated that water curing duration is essential to continue the pozzolanic reaction in mortar which contributes to the development of strength of mortar made with PCC.

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

International Nuclear Information System (INIS)

Rungsimaphorn, B.; Rerkamnuaychoke, B.; Sudprasert, W.

2014-01-01

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 137 Cs 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.

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.

Secondary metabolite from Nostoc XPORK14A inhibits photosynthesis and growth of Synechocystis PCC 6803.

Science.gov (United States)

Shunmugam, Sumathy; Jokela, Jouni; Wahlsten, Matti; Battchikova, Natalia; Ateeq ur Rehman; Vass, Imre; Karonen, Maarit; Sinkkonen, Jari; Permi, Perttu; Sivonen, Kaarina; Aro, Eva-Mari; Allahverdiyeva, Yagut

2014-06-01

Screening of 55 different cyanobacterial strains revealed that an extract from Nostoc XPORK14A drastically modifies the amplitude and kinetics of chlorophyll a fluorescence induction of Synechocystis PCC6803 cells.After 2 d exposure to the Nostoc XPORK14A extract, Synechocystis PCC 6803 cells displayed reduced net photosynthetic activity and significantly modified electron transport properties of photosystem II under both light and dark conditions. However, the maximum oxidizable amount of P700 was not strongly affected. The extract also induced strong oxidative stress in Synechocystis PCC 6803 cells in both light and darkness. We identified the secondary metabolite of Nostoc XPORK14A causing these pronounced effects on Synechocystis cells. Mass spectrometry and nuclear magnetic resonance analyses revealed that this compound, designated as M22, has a non-peptide structure. We propose that M22 possesses a dualaction mechanism: firstly, by photogeneration of reactive oxygen species in the presence of light, which in turn affects the photosynthetic machinery of Synechocystis PCC 6803; and secondly, by altering the in vivo redox status of cells, possibly through inhibition of protein kinases.

Computational prediction of cAMP receptor protein (CRP binding sites in cyanobacterial genomes

Directory of Open Access Journals (Sweden)

Su Zhengchang

2009-01-01

Full Text Available Abstract Background Cyclic AMP receptor protein (CRP, also known as catabolite gene activator protein (CAP, is an important transcriptional regulator widely distributed in many bacteria. The biological processes under the regulation of CRP are highly diverse among different groups of bacterial species. Elucidation of CRP regulons in cyanobacteria will further our understanding of the physiology and ecology of this important group of microorganisms. Previously, CRP has been experimentally studied in only two cyanobacterial strains: Synechocystis sp. PCC 6803 and Anabaena sp. PCC 7120; therefore, a systematic genome-scale study of the potential CRP target genes and binding sites in cyanobacterial genomes is urgently needed. Results We have predicted and analyzed the CRP binding sites and regulons in 12 sequenced cyanobacterial genomes using a highly effective cis-regulatory binding site scanning algorithm. Our results show that cyanobacterial CRP binding sites are very similar to those in E. coli; however, the regulons are very different from that of E. coli. Furthermore, CRP regulons in different cyanobacterial species/ecotypes are also highly diversified, ranging from photosynthesis, carbon fixation and nitrogen assimilation, to chemotaxis and signal transduction. In addition, our prediction indicates that crp genes in modern cyanobacteria are likely inherited from a common ancestral gene in their last common ancestor, and have adapted various cellular functions in different environments, while some cyanobacteria lost their crp genes as well as CRP binding sites during the course of evolution. Conclusion The CRP regulons in cyanobacteria are highly diversified, probably as a result of divergent evolution to adapt to various ecological niches. Cyanobacterial CRPs may function as lineage-specific regulators participating in various cellular processes, and are important in some lineages. However, they are dispensable in some other lineages. The

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.

Backbone dynamics of reduced plastocyanin from the cyanobacterium Anabaena variabilis: Regions involved in electron transfer have enhanced mobility

DEFF Research Database (Denmark)

Ma, L.X.; Hass, M.A.S.; Vierick, N.

2003-01-01

The dynamics of the backbone of the electron-transfer protein plastocyanin from the cyanobacterium Anabaena variabilis were determined from the N-15 and C-13(alpha) R-1 and R-2) relaxation rates and steady-state [H-1]-N-15 and [H-1]-C-13 nuclear Overhauser effects (NOEs) using the model...

The hetC Gene Is a Direct Target of the NtcA Transcriptional Regulator in Cyanobacterial Heterocyst Development

Science.gov (United States)

Muro-Pastor, Alicia M.; Valladares, Ana; Flores, Enrique; Herrero, Antonia

1999-01-01

The heterocyst is the site of nitrogen fixation in aerobically grown cultures of some filamentous cyanobacteria. Heterocyst development in Anabaena sp. strain PCC 7120 is dependent on the global nitrogen regulator NtcA and requires, among others, the products of the hetR and hetC genes. Expression of hetC, tested by RNA- DNA hybridization, was impaired in an ntcA mutant. A nitrogen-regulated, NtcA-dependent putative transcription start point was localized at nucleotide −571 with respect to the hetC translational start. Sequences upstream from this transcription start point exhibit the structure of the canonical cyanobacterial promoter activated by NtcA, and purified NtcA protein specifically bound to a DNA fragment containing this promoter. Activation of expression of hetC during heterocyst development appears thus to be directly operated by NtcA. NtcA-mediated activation of hetR expression was not impaired in a hetC mutant, indicating that HetC is not an NtcA-dependent element required for hetR induction. PMID:10542167

Identification of a common cyanobacterial symbiont associated with Azolla spp. through molecular and morphological characterization of free-living and symbiotic cyanobacteria.

Science.gov (United States)

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, detected homologous sequences in DNA extracted from the free-living isolates. Sequences homologous to these probes were not detected in DNA from the symbiotically associated cyanobacteria. These analyses indicated that the isolates were not identical to the major cyanobacterial symbiont species residing in leaf cavities of Azolla spp. Nevertheless, striking similarities between several free-living isolates were observed. In every instance, the isolate from A. pinnata displayed banding patterns virtually identical to those of free-living cultures previously isolated from Azolla caroliniana and Azolla filiculoides. These results suggest the ubiquitous presence of a culturable minor cyanobacterial symbiont in at least three species of Azolla. Images PMID:1685078

Sintesa Precipitated Calcium Carbonate (PCC) dari Cangkang Kerang Darah (Anadara Granosa) dengan Variasi Ukuran Partikel dan Waktu Karbonasi

OpenAIRE

Rahmawati, Lucy; Amri, Amun; Zultiniar, Zultiniar; Yelmida, Yelmida

2015-01-01

Precipitated Calcium Carbonate (PCC) is a product of the processing of natural materials containing calcium carbonate resulting from the precipitation process with high purity. Bloodcockle shell can be used as a source of calcium for precipitated Calcium Carbonate. The purpose of this study to produce PCC of waste shells blood with carbonation method and determine the particle size of the PCC and the best carbonation time. Synthesis performed using carbonation method by adding nitric acid to ...

Protein (Cyanobacteria): 218248342 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available ... hypothetical protein PCC8801_3595 Cyanothece sp. PCC 8801 MSIQYLLDENLPHLYREQLLRLKSDLTVWIIGDPGVPPKSTLDPEILIWCEQNKFILVTNNRASMPVHLADHLSQNRHIPGIFVLRPKASIGEIIDDLILIDELGNPQDYQDCISHIPFI

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

International Nuclear Information System (INIS)

Qadir, Abdul; Sharma, Manish; Parvareh, Forough; Khalilpour, Rajab; Abbas, Ali

2015-01-01

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-CO 2 and a higher price of $50/tonne-CO 2 . 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

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

Czech Academy of Sciences Publication Activity Database

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

2007-01-01

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

Fundamental Frequency Estimation of the Speech Signal Compressed by MP3 Algorithm Using PCC Interpolation

Directory of Open Access Journals (Sweden)

MILIVOJEVIC, Z. N.

2010-02-01

Full Text Available In this paper the fundamental frequency estimation results of the MP3 modeled speech signal are analyzed. The estimation of the fundamental frequency was performed by the Picking-Peaks algorithm with the implemented Parametric Cubic Convolution (PCC interpolation. The efficiency of PCC was tested for Catmull-Rom, Greville and Greville two-parametric kernel. Depending on MSE, a window that gives optimal results was chosen.

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

Directory of Open Access Journals (Sweden)

Tim Crawford

2016-07-01

Full Text Available 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.

AcEST: DK957899 [AcEST

Lifescience Database Archive (English)

Full Text Available en family member 3 OS=Homo sapiens ... 45 2e-04 sp|Q753M3|PCC1_ASHGO Polarized growth chromatin-associated c...MQRFG 138 >sp|Q753M3|PCC1_ASHGO Polarized growth chromatin-associated controller

Evaluation of MIT-SCAN-T2 for thickness quality control for PCC and HMA pavements : research project capsule.

Science.gov (United States)

2013-04-01

Thickness is currently a pay item for portland cement concrete (PCC) pavements : and a quality control item for both PCC and hot mix asphalt (HMA) pavements. : A change in pavement thickness of 0.5 in. can result in a reduction of multiple : years of...

Determination of The Adaptation of Some Azolla (Azolla anabaena L) Genotypes to The Mediterranean and Aegean Coastline Ecological Conditions

OpenAIRE

GEVREK, Mithat Nuri

2015-01-01

u çalışmada bazı azolla (Azolla anabaena L.) genotiplerinin Akdeniz-Ege kıyı kuşağına adaptasyonunun belirlenmesi amaçlanmıştır. Araştırma 20022003 ve 2003-2004 yıllarında Ege Üniversitesi Ziraat Fakültesi’nin Menemen

Morphological diversity of coiled planktonic types of the genus .i.Anabaena./i. (cyanobacteria) in natural populations – taxonomic consequences

Czech Academy of Sciences Publication Activity Database

Zapomělová, Eliška; Řeháková, Klára; Znachor, Petr; Komárková, Jaroslava

2007-01-01

Roč. 28, č. 4 (2007), s. 353-371 ISSN 0181-1568 R&D Projects: GA ČR(CZ) GA206/06/0462; GA AV ČR(CZ) KJB600960703 Institutional research plan: CEZ:AV0Z60170517 Keywords : Anabaena * cyanobacteria * morphological diversity * natural populations * species identification * taxonomy Subject RIV: EE - Microbiology, Virology Impact factor: 0.483, year: 2007

Potential of Microalgae Cultivation in Dairy Wastewater as a Step in Low-Cost Biofuel Production

Directory of Open Access Journals (Sweden)

Basma Abbas Abdulmajeed

2018-04-01

Full Text Available The present study addresses adopting the organic and nutritious materials in dairy wastewater as media for cultivation of microalgae, which represent an important source of renewable energy. This study was carried out through cultivation of three types of microalgae; Chlorella sp., Synechococcus, and Anabaena. The results shows the success the cultivation of the Synechococcus and Chlorella Sp, while the Anabaena microalgae were in low-growth level. The highest growth was in the Synechococcus farm, followed by Chlorella and Anabaena. However, the growth of Synechococcus required 10 days to achieve this increase that represents a negative indicator of the adoption of this type of microalgae in this media to meet the desired aims. While Chlorella needs less than two days to start growing. Moreover, the data obtained from the experiment show that removal of chemical oxygen demand in Chlorella cultures was (72% more than that obtained from cultivation of other microalgae. Thus this microalgae is more efficient in wastewater treatment than other types.

Removal of uranyl ions from residual waters using some algae types

International Nuclear Information System (INIS)

Cecal, A.; Palamaru, I.; Humelnicu, D.; Popa, K.; Salaru, V.V.; Rudic, V.; Gulea, A.

1999-01-01

This paper deals with a study on the bioaccumulation of uranyl ions resulted from residual effluents by means of some microbiological collectors: Scenedesmus quadricauda, Anabaena karakumica, Calothrix brevissima, Penicillinium sp, as well as the Glucid extract of Porphyridium cruentum, under various experimental conditions. The retaining degree of the bioaccumulated uranyl ions, as well as the leaching degree, in HCl and H 2 O media, of the same ions previously retained on algae were established. The retaining degree decreases in the series: Scenedesmus quadricauda > Anabaena karakumica > Penicillinium sp > Calothrix brevissima. The leaching effect of bioaccumulated uranyl ions is higher in hydrochloric acid than in water. (author)

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...

EasyPCC: Benchmark Datasets and Tools for High-Throughput Measurement of the Plant Canopy Coverage Ratio under Field Conditions

Directory of Open Access Journals (Sweden)

Wei Guo

2017-04-01

Full Text Available Understanding interactions of genotype, environment, and management under field conditions is vital for selecting new cultivars and farming systems. Image analysis is considered a robust technique in high-throughput phenotyping with non-destructive sampling. However, analysis of digital field-derived images remains challenging because of the variety of light intensities, growth environments, and developmental stages. The plant canopy coverage (PCC ratio is an important index of crop growth and development. Here, we present a tool, EasyPCC, for effective and accurate evaluation of the ground coverage ratio from a large number of images under variable field conditions. The core algorithm of EasyPCC is based on a pixel-based segmentation method using a decision-tree-based segmentation model (DTSM. EasyPCC was developed under the MATLAB® and R languages; thus, it could be implemented in high-performance computing to handle large numbers of images following just a single model training process. This study used an experimental set of images from a paddy field to demonstrate EasyPCC, and to show the accuracy improvement possible by adjusting key points (e.g., outlier deletion and model retraining. The accuracy (R2 = 0.99 of the calculated coverage ratio was validated against a corresponding benchmark dataset. The EasyPCC source code is released under GPL license with benchmark datasets of several different crop types for algorithm development and for evaluating ground coverage ratios.

Biocatalytic synthesis of flavones and hydroxyl-small molecules by recombinant Escherichia coli cells expressing the cyanobacterial CYP110E1 gene

Directory of Open Access Journals (Sweden)

Makino Takuya

2012-07-01

Full Text Available Abstract Background Cyanobacteria possess several cytochrome P450s, but very little is known about their catalytic functions. CYP110 genes unique to cyanaobacteria are widely distributed in heterocyst-forming cyanobacteria including nitrogen-fixing genera Nostoc and Anabaena. We screened the biocatalytic functions of all P450s from three cyanobacterial strains of genus Nostoc or Anabaena using a series of small molecules that contain flavonoids, sesquiterpenes, low-molecular-weight drugs, and other aromatic compounds. Results Escherichia coli cells carrying each P450 gene that was inserted into the pRED vector, containing the RhFRed reductase domain sequence from Rhodococcus sp. NCIMB 9784 P450RhF (CYP116B2, were co-cultured with substrates and products were identified when bioconversion reactions proceeded. Consequently, CYP110E1 of Nostoc sp. strain PCC 7120, located in close proximity to the first branch point in the phylogenetic tree of the CYP110 family, was found to be promiscuous for the substrate range mediating the biotransformation of various small molecules. Naringenin and (hydroxyl flavanones were respectively converted to apigenin and (hydroxyl flavones, by functioning as a flavone synthase. Such an activity is reported for the first time in prokaryotic P450s. Additionally, CYP110E1 biotransformed the notable sesquiterpene zerumbone, anti-inflammatory drugs ibuprofen and flurbiprofen (methylester forms, and some aryl compounds such as 1-methoxy and 1-ethoxy naphthalene to produce hydroxylated compounds that are difficult to synthesize chemically, including novel compounds. Conclusion We elucidated that the CYP110E1 gene, C-terminally fused to the P450RhF RhFRed reductase domain sequence, is functionally expressed in E. coli to synthesize a robust monooxygenase, which shows promiscuous substrate specificity (affinity for various small molecules, allowing the biosynthesis of not only flavones (from flavanones but also a variety of

Determination of the glycogen content in cyanobacteria

DEFF Research Database (Denmark)

Porcellinis, Alice De; Frigaard, Niels-Ulrik; Sakuragi, Yumiko

2017-01-01

of glycogen to generate glucose monomers, which are detected by a glucose oxidase-peroxidase (GOD-POD) enzyme coupled assay. The method has been applied to Synechocystis sp. PCC 6803 and Synechococcus sp. PCC 7002, two model cyanobacterial species that are widely used in metabolic engineering. Moreover...

Molecular cloning of a recA-like gene from the cyanobacterium Anabaena variabilis

International Nuclear Information System (INIS)

Owttrim, G.W.; Coleman, J.R.

1987-01-01

A recA-like gene isolated from the cyanobacterium Anabaena variabilis was cloned and partially characterized. When introduced into Escherichia coli recA mutants, the 7.5-kilobase-pair plasmid-borne DNA insert restored resistance to methyl methanesulfonate and UV irradiation, as well as recombination proficiency when measured by Hfr-mediated conjugation. The cyanobacterial recA gene restored spontaneous but not mitomycin C-induced prophage production. Restriction analysis and subcloning yielded a 1.5-kilobase-pair Sau3A fragment which also restored methylmethane sulfonate resistance and coded for a 38- to 40-kilodalton polypeptide when expressed in an in vitro transcription-translation system

Final Techno-Economic Analysis of 550 MWe Supercritical PC Power Plant CO₂ Capture with Linde-BASF Advanced PCC Technology

Energy Technology Data Exchange (ETDEWEB)

Bostick, Devin [Linde LLC, Murray Hill, NJ (United States); Stoffregen, Torsten [Linde AG Linde Engineering Division, Dresden (Germany); Rigby, Sean [BASF Corporation, Houston, TX (United States)

2017-01-09

This topical report presents the techno-economic evaluation of a 550 MWe supercritical pulverized coal (PC) power plant utilizing Illinois No. 6 coal as fuel, integrated with 1) a previously presented (for a subcritical PC plant) Linde-BASF post-combustion CO₂ capture (PCC) plant incorporating BASF’s OASE® blue aqueous amine-based solvent (LB1) [Ref. 6] and 2) a new Linde-BASF PCC plant incorporating the same BASF OASE® blue solvent that features an advanced stripper interstage heater design (SIH) to optimize heat recovery in the PCC process. The process simulation and modeling for this report is performed using Aspen Plus V8.8. Technical information from the PCC plant is determined using BASF’s proprietary thermodynamic and process simulation models. The simulations developed and resulting cost estimates are first validated by reproducing the results of DOE/NETL Case 12 representing a 550 MWe supercritical PC-fired power plant with PCC incorporating a monoethanolamine (MEA) solvent as used in the DOE/NETL Case 12 reference [Ref. 2]. The results of the techno-economic assessment are shown comparing two specific options utilizing the BASF OASE® blue solvent technology (LB1 and SIH) to the DOE/NETL Case 12 reference. The results are shown comparing the energy demand for PCC, the incremental fuel requirement, and the net higher heating value (HHV) efficiency of the PC power plant integrated with the PCC plant. A comparison of the capital costs for each PCC plant configuration corresponding to a net 550 MWe power generation is also presented. Lastly, a cost of electricity (COE) and cost of CO₂ captured assessment is shown illustrating the substantial cost reductions achieved with the Linde-BASF PCC plant utilizing the advanced SIH configuration in combination with BASF’s OASE® blue solvent technology as compared to the DOE/NETL Case 12 reference. The key factors contributing to the reduction of COE and the cost of CO₂ captured

Temperature induced changes in the heterocyst glycolipid composition of N

NARCIS (Netherlands)

Bauersachs, T.; Stal, L.J.; Grego, M.; Schwark, L.; Schwark, L.

2014-01-01

We investigated the effect of temperature on the heterocyst glycolipid (HG) composition of the diazotrophic heterocystous cyanobacteria Anabaena sp. strain CCY9613 and Nostoc sp. strain CCY9926 grown at 9, 12, 16, 20 and 24 degrees C. Both strains contained an overall similar composition of

Temperature induced changes in the heterocyst glycolipid composition of N2-fixing heterocystous cyanobacteria

NARCIS (Netherlands)

Bauersachs, T.; Stal, L.J.; Grego, M.; Schwark, L.

2014-01-01

We investigated the effect of temperature on the heterocyst glycolipid (HG) composition of the diazotrophic heterocystous cyanobacteria Anabaena sp. strain CCY9613 and Nostoc sp. strain CCY9926 grown at 9, 12, 16, 20 and 24 °C. Both strains contained an overall similar composition of heterocyst

Synthesis of Hydroxyapatite using Precipitated Calcium Carbonate (PCC) from Limestones

Science.gov (United States)

Wardhani, Sri; Isnaini Azkiya, Noor; Triandi Tjahjanto, Rachmat

2018-01-01

Hydroxyapatite (HAp) is a material that widely applied in bone and teeth implant due to its biocompatibility and bioactivity. This material can be prepared from PCC by precipitation method using CaO and H3PO4 in ethanol. In this work, variations of phosphoric acid amount and aging time were investigated. The synthesized HAp was characterized by FT-IR, AAS, UV-Vis Spectrophotometer, PSA, SEM, and powder XRD. The results showed that the high concentration of calcium in PCC gives better yields in which PCC obtained from carbonation method has higher yield than that of caustic soda method. The determination of optimum phosphoric acid addition based on targeted Ca/P ratio (1.67) from HAp was obtained on the addition of 0.1271 mol phosphoric acid with Ca/P ratio of 1.66. The aging time gave significant effect to the particle size of synthesised HAp. The smallest particle size was obtained in aging time for 48 hours as high as 49.25 μm. FTIR spectra of the synthesized HAp show the presence of hydroxyl (-OH) group at 3438.8 cm-1, PO4 3- at 557.39 and 1035.7 cm-1, and CaO at 1413.72 cm-1. The synthesized HAp forms agglomeration solid based on the SEM analysis. The powder XRD data shows three highest peaks at 2θ i.e. 27.8296; 31.1037; and 34.3578 which corresponds to β-TCP (tricalcium phosphate) in accordance with JCPDS no.09-0169. The characteristic 2θ peak of hydroxyapatite with low intensity is observed from the synthesized HAp refer to the JCPDS data no. 09-0432.

Determination of DPPH Radical Oxidation Caused by Methanolic Extracts of Some Microalgal Species by Linear Regression Analysis of Spectrophotometric Measurements

Directory of Open Access Journals (Sweden)

Ulf-Peter Hansen

2007-10-01

Full Text Available The demonstrated modified spectrophotometric method makes use of the 2,2-diphenyl-1-picrylhydrazyl (DPPH radical and its specific absorbance properties. Theabsorbance decreases when the radical is reduced by antioxidants. In contrast to otherinvestigations, the absorbance was measured at a wavelength of 550 nm. This wavelengthenabled the measurements of the stable free DPPH radical without interference frommicroalgal pigments. This approach was applied to methanolic microalgae extracts for twodifferent DPPH concentrations. The changes in absorbance measured vs. the concentrationof the methanolic extract resulted in curves with a linear decrease ending in a saturationregion. Linear regression analysis of the linear part of DPPH reduction versus extractconcentration enabled the determination of the microalgae’s methanolic extractsantioxidative potentials which was independent to the employed DPPH concentrations. Theresulting slopes showed significant differences (6 - 34 μmol DPPH g-1 extractconcentration between the single different species of microalgae (Anabaena sp.,Isochrysis galbana, Phaeodactylum tricornutum, Porphyridium purpureum, Synechocystissp. PCC6803 in their ability to reduce the DPPH radical. The independency of the signal on the DPPH concentration is a valuable advantage over the determination of the EC50 value.

Molecular Diffusion through Cyanobacterial Septal Junctions

Directory of Open Access Journals (Sweden)

Mercedes Nieves-Morión

2017-01-01

Full Text Available Heterocyst-forming cyanobacteria grow as filaments in which intercellular molecular exchange takes place. During the differentiation of N2-fixing heterocysts, regulators are transferred between cells. In the diazotrophic filament, vegetative cells that fix CO2 through oxygenic photosynthesis provide the heterocysts with reduced carbon and heterocysts provide the vegetative cells with fixed nitrogen. Intercellular molecular transfer has been traced with fluorescent markers, including calcein, 5-carboxyfluorescein, and the sucrose analogue esculin, which are observed to move down their concentration gradient. In this work, we used fluorescence recovery after photobleaching (FRAP assays in the model heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120 to measure the temperature dependence of intercellular transfer of fluorescent markers. We find that the transfer rate constants are directly proportional to the absolute temperature. This indicates that the “septal junctions” (formerly known as “microplasmodesmata” linking the cells in the filament allow molecular exchange by simple diffusion, without any activated intermediate state. This constitutes a novel mechanism for molecular transfer across the bacterial cytoplasmic membrane, in addition to previously characterized mechanisms for active transport and facilitated diffusion. Cyanobacterial septal junctions are functionally analogous to the gap junctions of metazoans.

Protein (Cyanobacteria): 414077569 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available lasmid addiction system poison protein Anabaena sp. 90 MLINLNENINYTVVIGIDAQDFFESASATLQKKLDRCFEILKIEPRNYPNIKALKGEFSGYYRYRVGDYRVIYEIDDNSKLVTILLIAHRSKVYE ... YP_006996887.1 NC_019440 1117:5824 ... 1161:889 ... 1162:2120 1163:3278 46234:816 ... p

The Ribosome-Bound Protein Pam68 Promotes Insertion of Chlorophyll into the CP47 Subunit of Photosystem II

Czech Academy of Sciences Publication Activity Database

Bučinská, Lenka; Kiss, Eva; Koník, Peter; Knoppová, Jana; Komenda, Josef; Sobotka, Roman

2018-01-01

Roč. 176, č. 4 (2018), s. 2931-2942 ISSN 0032-0889 R&D Projects: GA MŠk(CZ) LO1416; GA MŠk(CZ) ED2.1.00/19.0392 Institutional support: RVO:61388971 Keywords : SYNECHOCYSTIS SP PCC-6803 * SP PCC 6803 * ESCHERICHIA-COLI Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 6.456, year: 2016

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

Science.gov (United States)

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

2012-09-28

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

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

Science.gov (United States)

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

2012-01-01

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

ORGANIZATION OF THE nif GENES OF THE NONHETEROCYSTOUS CYANOBACTERIUM TRICHODESMIUM SP. IMS101.

Science.gov (United States)

Dominic, Benny; Zani, Sabino; Chen, Yi-Bu; Mellon, Mark T; Zehr, Jonathan P

2000-08-26

An approximately 16-kb fragment of the Trichodesmium sp. IMS101 (a nonheterocystous filamentous cyanobacterium) "conventional"nif gene cluster was cloned and sequenced. The gene organization of the Trichodesmium and Anabaena variabilis vegetative (nif 2) nitrogenase gene clusters spanning the region from nif B to nif W are similar except for the absence of two open reading frames (ORF3 and ORF1) in Trichodesmium. The Trichodesmium nif EN genes encode a fused Nif EN polypeptide that does not appear to be processed into individual Nif E and Nif N polypeptides. Fused nif EN genes were previously found in the A. variabilis nif 2 genes, but we have found that fused nif EN genes are widespread in the nonheterocystous cyanobacteria. Although the gene organization of the nonheterocystous filamentous Trichodesmium nif gene cluster is very similar to that of the A. variabilis vegetative nif 2 gene cluster, phylogenetic analysis of nif sequences do not support close relatedness of Trichodesmium and A. variabilis vegetative (nif 2) nitrogenase genes.

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.

The persistence and ecological impacts of a cyanobacterium genetically engineered to express mosquitocidal Bacillus thuringiensis toxins.

Science.gov (United States)

Ketseoglou, Irene; Bouwer, Gustav

2016-05-10

The cyanobacterium Anabaena PCC 7120#11 has been genetically engineered to act as a delivery vehicle for Bacillus thuringiensis subspecies israelensis mosquitocidal toxins. To address ecological concerns about releasing this genetically engineered microorganism into the environment for mosquito larva control, the persistence and ecological impacts of PCC 7120#11 was evaluated using multi-species, standardized aquatic microcosms. The microcosms were set up as described in ASTM E1366-02 (Standard Practice for Standardized Aquatic Microcosms: Fresh Water), with a few modifications. The treatment group microcosms were inoculated with PCC 7120#11 and key water quality parameters and non-target effects were compared between the treatment and control groups over a period of 35 days. PCC 7120#11 decreased from a concentration of 4.50 × 10(6) cells/ml (at inoculation) to 1.32 × 10(3) cells/ml after 4 weeks and larvicidal activity against third instar larvae of Anopheles arabiensis was only evident for two weeks after treatment. Both treatment and the interaction of treatment and time had a significant effect on nitrate, phosphate and photosynthetic microorganism concentrations. Treatment with PCC 7120#11 caused a temporary spike in ammonia in the microcosms a week after treatment, but the concentrations were well below acute and chronic criteria values for ammonia in freshwater ecosystems. Cyprinotus vidua concentrations were not significantly different between PCC 7120#11 and control microcosms. In PCC 7120#11 microcosms, Daphnia pulex concentrations were significantly lower than control concentrations between days 18 and 25. By the end of the experiment, none of the measured variables were significantly different between the treatment groups. The standard aquatic microcosm experiments provided more data on the ecological impacts of PCC 7120#11 than single-organism assessments would have. On the basis of the relatively minor, short-term effects that PCC 7120

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.

The effect of coatings and coating weight by two types of PCC on barrier and optical properties and roughness of paper

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rouzbeh asadi khansari

2017-08-01

Full Text Available The objective of this work is to investigate the use of PCC, and the impact of its coating weight on paper coating. In this study, two base papers from Mazandaran Wood and Paper Industries (APC and NS, and two coating compositions with the solid content of 25% containing PCC filler (100 parts, PVA binder (14 parts and dispersant (1 part were used. The first composition included PCC B102 for opacity increment, and the second one PCC 9020 for the improvement of brightness. Two rod RDS14 and RDS30 were used for different coating weights. After coating, the treated samples were dried in room conditions at air temperature of 25◦C and relative humidity of 54%. Physical and optical properties of control and treated samples such as air resistance, thickness, Cobb60, brightness, yellowness, opacity and roughness were determined. In comparison to the control group, all the treated samples showed improvement in brightness, opacity, yellowness and air resistance. By the two different formulations and two rods, paper roughness was increased, and the increment of water absorption was due to capillary development in coating texture. The analysis of variances showed that the usage of PCC 9020 had considerable effect on roughness of papers. In NS papers, change of PCC caused significant difference in brightness and roughness, but in APC papers did not. The change of coating rod in APC papers had significant effect on water absorption, brightness and opacity but did not show in NS.

Nostoc PCC7524, a cyanobacterium which contains five sequence-specific deoxyribonucleases

NARCIS (Netherlands)

Reaston, J.; Duybesteyn, M.G.C.; Waard, Adrian de

1982-01-01

Five nucleotide sequence-specific deoxyribonucleases present in cell-free extracts of the filamentous cyanobacterium Nostoc PCC7524 have been purified and characterized. One of these enzymes, designated Nsp(7524)I cleaves at a new kind of nucleotide sequence i.e. 5'-PuCATG λ Py-3'. The other four

Presence and expression of hydrogenase specific C-terminal endopeptidases in cyanobacteria

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Lindblad Peter

2003-05-01

Full Text Available Abstract Background Hydrogenases catalyze the simplest of all chemical reactions: the reduction of protons to molecular hydrogen or vice versa. Cyanobacteria can express an uptake, a bidirectional or both NiFe-hydrogenases. Maturation of those depends on accessory proteins encoded by hyp-genes. The last maturation step involves the cleavage of a ca. 30 amino acid long peptide from the large subunit by a C-terminal endopeptidase. Until know, nothing is known about the maturation of cyanobacterial NiFe-hydrogenases. The availability of three complete cyanobacterial genome sequences from strains with either only the uptake (Nostoc punctiforme ATCC 29133/PCC 73102, only the bidirectional (Synechocystis PCC 6803 or both NiFe-hydrogenases (Anabaena PCC 7120 prompted us to mine these genomes for hydrogenase maturation related genes. In this communication we focus on the presence and the expression of the NiFe-hydrogenases and the corresponding C-terminal endopeptidases, in the three strains mentioned above. Results We identified genes encoding putative cyanobacterial hydrogenase specific C-terminal endopeptidases in all analyzed cyanobacterial genomes. The genes are not part of any known hydrogenase related gene cluster. The derived amino acid sequences show only low similarity (28–41% to the well-analyzed hydrogenase specific C-terminal endopeptidase HybD from Escherichia coli, the crystal structure of which is known. However, computational secondary and tertiary structure modeling revealed the presence of conserved structural patterns around the highly conserved active site. Gene expression analysis shows that the endopeptidase encoding genes are expressed under both nitrogen-fixing and non-nitrogen-fixing conditions. Conclusion Anabaena PCC 7120 possesses two NiFe-hydrogenases and two hydrogenase specific C-terminal endopeptidases but only one set of hyp-genes. Thus, in contrast to the Hyp-proteins, the C-terminal endopeptidases are the only known

CalA, a Cyanobacterial AbrB Protein, Interacts with the Upstream Region of hypC and Acts as a Repressor of Its Transcription in the Cyanobacterium Nostoc sp. Strain PCC 7120▿ †

Science.gov (United States)

Agervald, Åsa; Zhang, Xiaohui; Stensjö, Karin; Devine, Ellenor; Lindblad, Peter

2010-01-01

The filamentous, heterocystous, nitrogen-fixing cyanobacterium Nostoc sp. strain PCC 7120 may contain, depending on growth conditions, up to two hydrogenases directly involved in hydrogen metabolism. HypC is one out of at least seven auxiliary gene products required for synthesis of a functional hydrogenase, specifically involved in the maturation of the large subunit. In this study we present a protein, CalA (Alr0946 in the genome), belonging to the transcription regulator family AbrB, which in protein-DNA assays was found to interact with the upstream region of hypC. Transcriptional investigations showed that calA is cotranscribed with the downstream gene alr0947, which encodes a putative protease from the abortive infection superfamily, Abi. CalA was shown to interact specifically not only with the upstream region of hypC but also with its own upstream region, acting as a repressor on hypC. The bidirectional hydrogenase activity was significantly downregulated when CalA was overexpressed, demonstrating a correlation with the transcription factor, either direct or indirect. In silico studies showed that homologues to both CalA and Alr0947 are highly conserved proteins within cyanobacteria with very similar physical organizations of the corresponding structural genes. Possible functions of the cotranscribed downstream protein Alr0947 are presented. In addition, we present a three-dimensional (3D) model of the DNA binding domain of CalA and putative DNA binding mechanisms are discussed. PMID:20023111

Production of precipitated calcium carbonate from industrial byproduct slags; Saostetun kalsiumkarbonaatin tuotanto karbonaattivapaista kuonatuotteista (SLAG2PCC)

Energy Technology Data Exchange (ETDEWEB)

Zevenhoven, R. [Aabo Akademi, Turku (Finland). Heat Engineering Lab.; Teir, S.; Eloneva, S.; Savolahti, J. [Helsinki Univ. of Technology, Espoo (Finland). Energy Technology and Environmental Protection

2006-12-19

Production of precipitate calcium carbonate from industrial by- product slags-project, 'SLAG2PCC', is a spin-off from ClimBus technology programme CO{sub 2} Nordic Plus-project, financed by the Finnish Technology Agency Tekes and the Finnish Recovery Boiler Committee. 'SLAG2PCC'-project is financed by Tekes, Ruukki Productions, UPM Kymmene and Waertsilae Finland. The possibility to produce precipitated calcium carbonate, PCC, from carbonate free industrial by-products (slags), combined with binding of carbon dioxide for climate change mitigation is studied in this project. The suitability of a process found from the literature, in which calcium used for carbonation is dissolved from calcium silicates using acetic acid as a solvent, is investigated for the carbonation of slags from the steel industry. During the calcium extraction experiments performed in the CO2 Nordic Plus - project it was found out that calcium is rapidly extracted from blast furnace and basic oxygen furnace slags. Atmospheric carbonation of the solution containing the dissolved slag and acetic acid directly has not succeeded yet due to low pH of the solution. Addition of NaOH, to increase of the solution pH, resulted in calcium carbonate precipitate in atmospheric pressure. The future goal of the project is to optimize process conditions so that the formed calcium carbonate is suitable for use as PCC. (orig.)

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

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Liz M. Rösken

2016-03-01

Full Text Available 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.

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.

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

International Nuclear Information System (INIS)

Pham Ngoc Duy; Tran Que; Hoang Hung Tien; Bui Thi Kim Luyen; Nguyen Thi Kim Anh; Ha Thi Ngoc Lien

2014-01-01

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 60 Co (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 60 Co (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)

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

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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.

Degradation of textile dyes by cyanobacteria.

Science.gov (United States)

Dellamatrice, Priscila Maria; Silva-Stenico, Maria Estela; Moraes, Luiz Alberto Beraldo de; Fiore, Marli Fátima; Monteiro, Regina Teresa Rosim

Dyes are recalcitrant compounds that resist conventional biological treatments. The degradation of three textile dyes (Indigo, RBBR and Sulphur Black), and the dye-containing liquid effluent and solid waste from the Municipal Treatment Station, Americana, São Paulo, Brazil, by the cyanobacteria Anabaena flos-aquae UTCC64, Phormidium autumnale UTEX1580 and Synechococcus sp. PCC7942 was evaluated. The dye degradation efficiency of the cyanobacteria was compared with anaerobic and anaerobic-aerobic systems in terms of discolouration and toxicity evaluations. The discoloration was evaluated by absorption spectroscopy. Toxicity was measured using the organisms Hydra attenuata, the alga Selenastrum capricornutum and lettuce seeds. The three cyanobacteria showed the potential to remediate textile effluent by removing the colour and reducing the toxicity. However, the growth of cyanobacteria on sludge was slow and discoloration was not efficient. The cyanobacteria P. autumnale UTEX1580 was the only strain that completely degraded the indigo dye. An evaluation of the mutagenicity potential was performed by use of the micronucleus assay using Allium sp. No mutagenicity was observed after the treatment. Two metabolites were produced during the degradation, anthranilic acid and isatin, but toxicity did not increase after the treatment. The cyanobacteria showed the ability to degrade the dyes present in a textile effluent; therefore, they can be used in a tertiary treatment of effluents with recalcitrant compounds. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Effects of UV-B irradiation on growth, survival, pigmentation and nitrogen metabolism enzymes in Cyanobacteria

Energy Technology Data Exchange (ETDEWEB)

Sinha, R.P.; Hader, D.P. [Institut fuer Botanik und Pharmazeutische Biologie, Friedrich-Alexander Universitaet, Erlangen (Germany); Kumar, H.D.; Kumar, A. [Banaras Hindu University, Varanasi (India)

1995-12-31

The effects of artificial UV-B irradiation on growth, survival, pigmentation, nitrate reductase (NR), glutamine synthetase (GS) and total protein profile have been studied in a number of N{sub 2}-fixing cyanobacterial strains isolated from rice (paddy) fields in India. Different organisms show different effects in terms of growth and survival. Complete killing of Anabaena sp. and Nostoc carmium occurs after 120 min of UV-B exposure, whereas the same occurs only after 150 min of exposure in the case of Nostoc commune and Scytonema sp. Growth patterns of the cells treated with UV-B revealed that Nostoc commune and Scytonema sp. are comparatively more tolerant than Anabaena sp. and Nostoc carmium. Pigment content, particularly phycocyanin, was severely decreased following UV-B irradiation in all strains tested so far. In vivo NR activity was found to increase, while in vivo GS activity was decreased following exposure to UV-B for different durations in all test organisms; although complete inhibition of GS activity did not occur even after 120 min of UV-B exposure. (author). 37 refs, 6 figs.

Effects of UV-B irradiation on growth, survival, pigmentation and nitrogen metabolism enzymes in Cyanobacteria

International Nuclear Information System (INIS)

Sinha, R.P.; Hader, D.P.; Kumar, H.D.; Kumar, A.

1995-01-01

The effects of artificial UV-B irradiation on growth, survival, pigmentation, nitrate reductase (NR), glutamine synthetase (GS) and total protein profile have been studied in a number of N 2 -fixing cyanobacterial strains isolated from rice (paddy) fields in India. Different organisms show different effects in terms of growth and survival. Complete killing of Anabaena sp. and Nostoc carmium occurs after 120 min of UV-B exposure, whereas the same occurs only after 150 min of exposure in the case of Nostoc commune and Scytonema sp. Growth patterns of the cells treated with UV-B revealed that Nostoc commune and Scytonema sp. are comparatively more tolerant than Anabaena sp. and Nostoc carmium. Pigment content, particularly phycocyanin, was severely decreased following UV-B irradiation in all strains tested so far. In vivo NR activity was found to increase, while in vivo GS activity was decreased following exposure to UV-B for different durations in all test organisms; although complete inhibition of GS activity did not occur even after 120 min of UV-B exposure. (author)

Discovery of Rare and Highly Toxic Microcystins from Lichen-Associated Cyanobacterium Nostoc sp. Strain IO-102-I

Science.gov (United States)

Oksanen, Ilona; Jokela, Jouni; Fewer, David P.; Wahlsten, Matti; Rikkinen, Jouko; Sivonen, Kaarina

2004-01-01

The production of hepatotoxic cyclic heptapeptides, microcystins, is almost exclusively reported from planktonic cyanobacteria. Here we show that a terrestrial cyanobacterium Nostoc sp. strain IO-102-I isolated from a lichen association produces six different microcystins. Microcystins were identified with liquid chromatography-UV mass spectrometry by their retention times, UV spectra, mass fragmentation, and comparison to microcystins from the aquatic Nostoc sp. strain 152. The dominant microcystin produced by Nostoc sp. strain IO-102-I was the highly toxic [ADMAdda5]microcystin-LR, which accounted for ca. 80% of the total microcystins. We assigned a structure of [DMAdda5]microcystin-LR and [d-Asp3,ADMAdda5]microcystin-LR and a partial structure of three new [ADMAdda5]-XR type of microcystin variants. Interestingly, Nostoc spp. strains IO-102-I and 152 synthesized only the rare ADMAdda and DMAdda subfamilies of microcystin variants. Phylogenetic analyses demonstrated congruence between genes involved directly in microcystin biosynthesis and the 16S rRNA and rpoC1 genes of Nostoc sp. strain IO-102-I. Nostoc sp. strain 152 and the Nostoc sp. strain IO-102-I are distantly related, revealing a sporadic distribution of toxin production in the genus Nostoc. Nostoc sp. strain IO-102-I is closely related to Nostoc punctiforme PCC 73102 and other symbiotic Nostoc strains and most likely belongs to this species. Together, this suggests that other terrestrial and aquatic strains of the genus Nostoc may have retained the genes necessary for microcystin biosynthesis. PMID:15466511

Growth and cellular ion content of a salt-sensitive symbiotic system Azolla pinnata-Anabaena azollae under NaCl stress.

Science.gov (United States)

Rai, Vandna; Sharma, Naveen Kumar; Rai, Ashwani K

2006-09-01

Salinity, at a concentration of 10 mM NaCl affected the growth of Azolla pinnata-Anabaena azollae association and became lethal at 40 mM. Plants exposed up to 30 mM NaCl exhibited longer roots than the control, especially during the beginning of incubation. Average root number in plants exposed to 10 and 20 mM NaCl remained almost the same as in control. A further rise in NaCl concentration to 30 mM reduced the root number, and roots shed off at 40 mM NaCl. Presence of NaCl in the nutrient solution increased the cellular Na+ of the intact association exhibiting differential accumulation by individual partners, while it reduced the cellular Ca2+ level. However, cellular K+ content did not show significant change. Cellular Na+ based on fresh weight of respective individual partners (host tissues and cyanobiont) remained higher in the host tissues than the cyanobiont, while reverse was true for K+ and Ca2+ contents. The contribution of A. azollae in the total cellular ion content of the association was a little because of meagre contribution of the cyanobiont mass (19-21%). High salt sensitivity of Azolla-Anabaena complex is due to an inability of the association to maintain low Na+ and high Ca2+ cellular level.

Effect of addition of Navicula sp. on plankton composition and postlarvae growth of Litopenaeus vannamei reared in culture tanks with zero water exchange

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Yllana Ferreira-Marinho

2014-07-01

Full Text Available The aim of this study was to evaluate the effect of the addition of Navicula sp. on plankton composition and postlarvae growth of Litopenaeus vannamei reared in culture tanks with zero water exchange systems. Four treatments were considered: zero water exchange (ZWE; ZWE with the addition of feed (ZWE-F; ZWE with the addition of Navicula sp. (ZWE-N and ZWE with the addition of feed and Navicula sp. (ZWE-FN, all in triplicate. Shrimp of 17.7 ± 0.02 mg were stocked at a density of 2500 shrimp m-3 and microalgae added on the 1st, 5th and 15th day at a density of 5x10(4 cell mL-1. The shrimp were fed a commercial feed composed by 42% crude protein four times a day except in the ZWE treatment. For data analysis we used Cochran, Shapiro-Wilk, ANOVA, Tukey and Student-t tests (P < 0.05. The most frequent genera were: Anabaena, Arcella, Asplanchma, Bosmina, Brachionus, Cylindrotheca, Daphnia, Fragilaria, Hemiaulus, Keratella, Orthoseira, Oscillatoria, Phymatodocis, Rhabdonema, Skeletonema, Sckizothrix and Ulothrix. Significant differences between treatments were observed for TAN, NO2-N, alkalinity, final weight, weight gain, final biomass, biomass gain, feed conversion ratio, specific growth rate and survival. The ZWE-FN treatment showed better production parameters, indicating the benefits of the addition of Navicula sp. as a natural food source for L. vannamei postlarvae in zero water exchange systems.

Genetic Basis for Geosmin Production by the Water Bloom-Forming Cyanobacterium, Anabaena ucrainica

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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.

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

Energy Technology Data Exchange (ETDEWEB)

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

2005-04-30

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

ORF Sequence: NC_000911 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available Synechocystis sp. PCC 6803] MYFLLVTLVILVFPLLSIALEWTTSGNSQALVDVLARWFVFWGVGVRLFLAGVVQITKPSFTAEKILGVQSQDSLILVKELGIGNLAIASVALGSIFVNAWVLGAALAGGIFYLLAGINHILQPERNAKENYAMATDLFLGLLLGGILFFAWQP

Protein (Cyanobacteria): 359322 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

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

ORF Sequence: NC_003240 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available Nostoc sp. PCC 7120] MEYPQINIKLLSEEDRELVKQAKQRAEDLRLTFKEFVLDCIRNALFEESPDDADSATAAEIEALKAQIAALSEKVNIPSASKTEVHTLQERLNQLRVGISNEIKKDREQLASLALALSRLESQIEQLVPSLNLQVDGEVNSNSDGDWLFGEDSGAELPLT

3D-nuclear heat generation in PCC-charcoal filter in TAPP-3 and 4

International Nuclear Information System (INIS)

Kaushal, Manish; Pradhan, A.S.; Kumar, A.N.

2006-01-01

This paper deals with the calculations of 3D nuclear heat generation profile in the charcoal filter and subsequently the commencement time of Primary Containment Cleanup (PCC) system of 540MWe Pressurized Heavy Water Reactor (PHWR). Fuel failure is predicted due to overheating of the fuel under loss of Coolant Accident (LOCA) without Emergency Core Cooling System (LOCA without ECCS). Subsequently fission product gasses along with water vapours are released to Reactor Building (RB) atmosphere. Plate-out and water trapping mechanism stabilizes the concentration of significant fission products i.e. radioiodines in about 4 hours before being circulated through charcoal filters of Containment Cleanup system. After cleaning up the RB atmosphere, it is discharged to outside atmosphere through stack. The isotopes of radioiodine emit beta and gamma radiations. Gamma radiations are partly stopped within the charcoal and heat is generated. The part of gamma radiations escaping the bed produce heat in the adjacent beds also. PCC system can be operated, after 4 hours of LOCA, based on radioiodine concentration in RB atmosphere. During iodine removal, the iodine concentration in the charcoal filter goes through a peak value. Maximum heat is generated in the filter if PCC fans stops eventually when iodine concentration in the filter is maximum. Analysis done by TRAFIC code indicates that the system can be commenced after 7 hrs of LOCA so that desorption temperature of charcoal is not reached. Accuracy in estimating heat generation rates in charcoal helps in deciding commencement of the system after LOCA

Protein (Cyanobacteria): 208270 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available transferase Halothece sp. PCC 7418 MKIVIARDFNDFARCIMIRTQVFVMEQGISAEIETDEWENHSTHYLAGDGEKALATARSRLINNQTAKIERVAVLKEARSQGVGTELMRYILQEIHSYSNIQTIKLGSQNSAIPFYEKLGFQVIGEEYLDAGIPHHLMMQRINT ...

Proteomic strategy for the analysis of the polychlorobiphenyl-degrading cyanobacterium Anabaena PD-1 exposed to Aroclor 1254.

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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

Multiple ketolases involved in light regulation of canthaxanthin biosynthesis in Nostoc punctiforme PCC 73102.

Science.gov (United States)

Schöpf, Lotte; Mautz, Jürgen; Sandmann, Gerhard

2013-05-01

In the genome of Nostoc punctiforme PCC 73102, three functional β-carotene ketolase genes exist, one of the crtO and two of the crtW type. They were all expressed and their corresponding enzymes were functional inserting 4-keto groups into β-carotene as shown by functional pathway complementation in Escherichia coli. They all synthesized canthaxanthin but with different efficiencies. Canthaxanthin is the photoprotective carotenoid of N. punctiforme PCC 73102. Under high-light stress, its synthesis was enhanced. This was caused by up-regulation of the transcripts of two genes in combination. The first crtB-encoding phytoene synthase is the gate way enzyme of carotenogenesis resulting in an increased inflow into the pathway. The second was the ketolase gene crtW148 which in high light takes over β-carotene conversion into canthaxanthin from the other ketolases. The other ketolases were down-regulated under high-light conditions. CrtW148 was also exclusively responsible for the last step in 4-keto-myxoxanthophyll synthesis.

Protein (Cyanobacteria): 518320325 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available ... hypothetical protein Calothrix sp. PCC 7103 MDYVHPFQMELHKLESMIVHVQYADIKEVDKTLASNDAVSTQAVGEEGGTKVSTRALGEEGGNILTTYAVGEEGGNILTTYAVGEEGGDKVTTQAVGEEGGTRVTTYAVGEEGGGRVTTKAVGEEGGSIIRR

Protein (Cyanobacteria): 52198 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available 02412 Synechococcus sp. PCC 7502 MKLTPYLFLTITVTAIIGTSVWQSSAQMNKMMNHNMDEMSMELGAADANLDLRFIDAMIPHHQGAVQMAKEALKK...SKRPEIQKLATAIIKAQQEEIAQLQKWRKLWYPNMSSTPMAWHGEMGHMMTMSASQQKAMMMSMDLGAGDAKFDLRFIDAMIPHHEGALTMAQEALSKSKRPEIQKLAKAIITSQKAEIIEMQKWRKAWY ...

Protein (Cyanobacteria): 504930526 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available hetical protein Rivularia sp. PCC 7116 MAEDNNLTNNSATNISSESQTLNKDIEELVTRQAKAWENADSEAIIADFAENGAFIAPGTSLKGKADIKKAAEDYFKEFTDTKVKITRIFSDGKEGGVEWTWSDKNKKTGEKSLIDDAIIFEIKDGKIIYWREYFDKQTVSS

Protein (Cyanobacteria): 69941 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

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

Protein (Cyanobacteria): 427708671 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available H endonuclease Nostoc sp. PCC 7107 MSSLYINAELRRLVARRADYICEYCLVSESDRSSGCQVDHIISVKHGGATTADNLCYACIFCNLQKGTDLGSINWQTGELVRFFNPRRDFWGEHFRLGEGVIQPLTDIGEVTARIFDFNCDERVIERQALILSGQYPSKSALKRINK

ORF Sequence: NC_003272 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available rotein [Nostoc sp. PCC 7120] MALMGATGSGKSTLLENLIGIKQPQSGKIWINDISLEPQTLPQVRRYIGFGFQDANDQLFMPTILEDITFGPLNYGVPAAIARDQARQLLADFGLEAYANRSAH...ELSGGQRRLAALAAILALEPAILILDEPTTGLDPAWRRHLARVLFNLPVQVMLIASHELHWLGKVTQRALVLSNGRIQLDNEIQPLLQNGEILEQLGLPIDW

Protein (Cyanobacteria): 7241 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available ulator Leptolyngbya sp. PCC 7375 MDAHAIAEQLGISAMAVRQHLYALQDEQLIAYEEEPRPMGRPAKLWHLTAAADRFFPEGYAELTLSLIHSVTEAFGADGLERLLDIRT...REQLGAYLAQMDGQDSWQDRLETLADIRTREGYMANVLPQEDGSMLLVENHCPICAAAEACTGLCDRELEIFQIVLGVEVERTEHILSGARRCAYRVVLDENQDE ...

Protein (Cyanobacteria): 39628 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available 3_3832 Microcoleus sp. PCC 7113 MQFPRRYFVLLPLTAVLSLLMVSCSESKVSQCNKIIKVANKAADEAKAITNGGKESDPKAMLKAADALDKASQEMESIKVSDDKLRDYQGRFFVMYRDTSKSTRDFITAFEKKDRPAAEAAIVKLQKTTALETPLVQEINKYCQPEK ...

Protein (Cyanobacteria): 504984031 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available DKRLFSQAVVQFQKALKAKDLEGDENTALIYNGLGYAHAAQEQYDIAIRQYKEALKLKPDYVVAFNNLGFAYEKKQLSAQALEAYESALALDPNNPTAKRRVEPLRKLYAPSAS ...pothetical protein Geitlerinema sp. PCC 7407 MDNSLTLSYLSLLLLLLAVASFFILRQVIRTRRTESTLSRLQNALKGGQGSAKDHYELGGIYL

Protein (Cyanobacteria): 652337765 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available othetical protein Fischerella sp. PCC 9605 MLTSYNIKDYEKAIFDFSKAIALEPNNPINHYERGNAYFLLKDYQRAIADYSKAIELKPNDSNAYELRGFAYFYLKGYQRAIA...DYTKVLELKTNDANAYELRGFAYFYLKGYQRAIADYSKAIELKPNNTNAYVLRGLAYYKLLDYQKAITDVQQASRLYYQQNNREGFQKAEDLLQELQSLINN

Protein (Cyanobacteria): 130081 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available n all1672 Nostoc sp. PCC 7120 MFKILFDSDLILDAVMNRTELAEDVRTLLENLHPSIRLYLTDVGLQKVSTYTYCLKNSQIPEIIVDWLQEQIQICPIDQGLLQKARYSPLRDFESAVELACINHYQLNAIVTNKPEDFIVTAHPLCVWSFADLWLRVNLESQLQATIHS ...

Protein (Cyanobacteria): 504944154 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available LLIFVFVISMSLVLIITSGKPPSFPASIPDQILGLLGISSTSYVLGKALQGIKPSSAEEPSSVATAASPPPSPEPQSYDGQDLPPS ...etical protein Calothrix sp. PCC 7507 MPNINDLFTILALVIGCIITIFVAVLEIFILIFIWDGTWNVNTRKGKRRGINLEKLISESSGDASLARFQ

Protein (Cyanobacteria): 205740 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available r protein) Oscillatoria sp. PCC 6506 MNNELLHSQFNATAVEFDPFASGEILVTAPATEAQKEIWLSVQMGDEANCAFNESQSLRLRGPLNLEILRS...SFQAIVQRHEALRTTLSADGSTLCITESLNLEIPLIDLSALSEQERKIQLAQLRRQAVEQPFNLEHGPLLRVQIIKLQAEEHLAIITAHHIICDGWSWGVFIPDLGAI

Protein (Cyanobacteria): 504943534 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available tical protein Calothrix sp. PCC 7507 MYSQQLRTAIYGFFKRSHHLQLNCIDLQLNCIDLQLSCIDLQLSCIDLQLSCIDLQLNCIDLQLSCIDLQLSCIDLQLSCIDLQLSCIDLQLSCI...DLQLSCIDLQLSCIDLQLSCIDLQLSCIDLQSLNYPFLHFTDSFFVVMGTLKI

Protein (Cyanobacteria): 515895859 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available 302 ... hypothetical protein Synechococcus sp. PCC 7336 MADRNESFTPQSCRHILSVEDCDGLRDHALGAPKYFIGRDIANDICLNSQFASRYHALLLRVPAEREGEYFYRLLDGDLEGKPSTNGLTVNGLKVSAHELHEGDEISFGPDAKATYRVECLSADAK

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

Czech Academy of Sciences Publication Activity Database

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

2016-01-01

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

Protein (Cyanobacteria): 464885 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available tein Nos7524_5075 Nostoc sp. PCC 7524 MSLSYDISSILNLLRSLPSTELRTVKEEIDSILKERGTTIRIPDPFKIVPAQVVLKDSNLEESTSEVKLEEEYQQINEDISEPSGVLNLSSIKDATDNKAEKKEAIQEIPRPLGIWKGKVEISEDFYETTNDILSEFGIEE ...

Protein (Cyanobacteria): 428225094 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available :1456 ... dihydroneopterin aldolase Geitlerinema sp. PCC 7407 MDRLQVCGIRCYGYTGFFEEERKLGQWFEVDLVFGLDVRAAGASDRL...DDTLDYGGAVQRVQSLVRQARFATIERLATAIAEDILHHTVAEEVTVRLTKVSPPIPDFGGHIALEITRSRAELHPGT

Protein (Cyanobacteria): 516255172 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available 7:613 ... hypothetical protein Geitlerinema sp. PCC 7105 MKNKATAALFAFFLGFLGIHKFYLGQNFSGVLYLILSWTGIPAILAIFDFLGLLLMSDATFNVRYNNMVTVVRDNLVVTPSPDRSRSATEITRALADLKKLYEVGAVTAEEYEEKRQKLLSEL

The Effect of Detergent Effluent on the Physico-Chemical ...

African Journals Online (AJOL)

MICHAEL HORSFALL

abundance of Anabaena and Oscillatoria sp. which are pollution indicator ... negative effect the effluent from the detergent factory has on the stream, thus ... in aquatic ecosystems and represents one of the most .... American Public Health Association (1998). ... (Cyanophyta) in Nigeria coastal waters. The ... South Western.

Quantification of Concentration of Microalgae Anabaena Cylindrica, Coal-bed Methane Water Isolates Nannochloropsis Gaditana and PW-95 in Aquatic Solutions through Hyperspectral Reflectance Measurement and Analytical Model Establishment

Science.gov (United States)

Zhou, Z.; Zhou, X.; Apple, M. E.; Spangler, L.

2017-12-01

Three species of microalgae, Anabaena cylindrica (UTEX # 1611), coal-bed methane water isolates Nannochloropsis gaditana and PW-95 were cultured for the measurements of their hyperspectral profiles in different concentrations. The hyperspectral data were measured by an Analytical Spectral Devices (ASD) spectroradiomter with the spectral resolution of 1 nanometer over the wavelength ranges from 350nm to 1050 nm for samples of microalgae of different concentration. Concentration of microalgae was measured using a Hemocytometer under microscope. The objective of this study is to establish the relation between spectral reflectance and micro-algal concentration so that microalgae concentration can be measured remotely by space- or airborne hyperspectral or multispectral sensors. Two types of analytical models, linear reflectance-concentration model and Lamber-Beer reflectance-concentration model, were established for each species. For linear modeling, the wavelength with the maximum correlation coefficient between the reflectance and concentrations of algae was located and then selected for each species of algae. The results of the linear models for each species are shown in Fig.1(a), in which Refl_1, Refl_2, and Refl_3 represent the reflectance of Anabaena, N. Gaditana, and PW-95 respectively. C1, C2, and C3 represent the Concentrations of Anabaena, N. Gaditana, and PW-95 respectively. The Lamber-Beer models were based on the Lambert-Beer Law, which states that the intensity of light propagating in a substance dissolved in a fully transmitting solvent is directly proportional to the concentration of the substance and the path length of the light through the solution. Thus, for the Lamber-Beer modeling, a wavelength with large absorption in red band was selected for each species. The results of Lambert-Beer models for each species are shown in Fig.1(b). Based on the Lamber-Beer models, the absorption coefficient for the three different species will be quantified.

Cianobactérias e algas reduzem os sintomas causados por Tobacco vosaic virus (tmv em plantas de fumo

Directory of Open Access Journals (Sweden)

André B. Beltrame

2011-06-01

Full Text Available As algas e as cianobactérias produzem uma grande diversidade de compostos com atividade biológica direta sobre microrganismos ou agem como ativadores de mecanismos de resistência em plantas. Em vista disso, foi investigada a manifestação dos sintomas causados pelo Tobacco mosaic virus (TMV em plantas de fumo previamente tratadas com cianobactérias ou algas. Quando as folhas plantas de fumo foram tratadas dois dias antes da inoculação, foi verificado que suspensões de células dos isolados de cianobactérias 004/02, 008/02, Anabaena sp. e Nostoc sp. 61; e do isolado de alga 061/02, bem como as preparações do conteúdo intracelular do isolado 004/02 (4 C e do filtrado do meio de cultivo do isolado 061/02 (61 M apresentaram efeito na redução do número de lesões locais provocadas por TMV em folhas de plantas fumo, cultivar TNN. Além disso, foi observado que os isolados Anabaena sp., Nostoc sp. 21 (cianobactéria, Nostoc sp. 61 e 090/02 (alga mostraram efeito direto sobre o vírus semi-purificado. Em vista disso, pode-se sugerir que os isolados estudados sintetizam compostos que agem diretamente sobre o TMV e/ou ativam o mecanismo de defesa de plantas contra fitopatógenos.

A comparison of G2 phase radiation-induced chromatid break kinetics using calyculin-PCC with those obtained using colcemid block.

Science.gov (United States)

Bryant, Peter E; Mozdarani, Hossein

2007-09-01

To study the possible influence of cell-cycle delay on cells reaching mitosis during conventional radiation-induced chromatid break experiments using colcemid as a blocking agent, we have compared the chromatid break kinetics following a single dose of gamma rays (0.75 Gy) in metaphase CHO cells using calyculin-induced premature chromosome condensation (PCC), with those using colcemid block. Calyculin-induced PCC causes very rapid condensation of G2 cell chromosomes without the need for a cell to progress to mitosis, hence eliminating any effect of cell-cycle checkpoint on chromatid break frequency. We found that the kinetics of the exponential first-order decrease in chromatid breaks with time after irradiation was similar (not significantly different) between the two methods of chromosome condensation. However, use of the calyculin-PCC technique resulted in a slightly increased rate of disappearance of chromatid breaks and thus higher frequencies of breaks at 1.5 and 2.5 h following irradiation. We also report on the effect of the nucleoside analogue ara A on chromatid break kinetics using the two chromosome condensation techniques. Ara A treatment of cells abrogated the decrease in chromatid breaks with time, both using the calyculin-PCC and colcemid methods. We conclude that cell-cycle delay may be a factor determining the absolute frequency of chromatid breaks at various times following irradiation of cells in G2 phase but that the first-order disappearance of chromatid breaks with time and its abrogation by ara A are not significantly influenced by the G2 checkpoint.

Draft genome sequences of six neonatal meningitis-causing escherichia coli isolates (SP-4, SP-5, SP-13, SP-16, SP-46, and SP-65)

Science.gov (United States)

Neonatal meningitis Escherichia coli isolates (SP-4, SP-5, SP-13, SP-16, SP-46, and SP-65) were recovered from infants in the Netherlands from 1989 to 1997. Here, we report the draft genome sequences for these six E. coli isolates, which are currently being used to validate food safety processing te...

Protein (Cyanobacteria): 516325726 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available 8:1201 ... hypothetical protein Oscillatoria sp. PCC 10802 MGHIPSSSFPDNRRAFSLWLWWGGLIEHRHVVAKIWALEIPGMNPTPQPPPRVRGGGERD...GFGGGGLIEHRHVVAKISALEIPGMNPAPQPPPRVRGGGERDGFGGGGFIDIRHVVAKIAGEPAPTNHRHPVSGEAADATHYIYADFEG

Protein (Cyanobacteria): 428309600 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available :1418 ... nitrogen fixation protein Microcoleus sp. PCC 7113 MTATNTTTETTTEEILAKPLMQELVKQIRGQDSYGTYRTWSDELLLKPFIVSKERKRKISVDGDVDLVTKARI...MAFYRAIAARIEQETGLLGQVIIDLSHEGFGWALVFCGRLLVVAKTLRDAQRFGFDSFEKLDAEGEKLLQKGIDLAKRYPEVGNI

Protein (Cyanobacteria): 176056 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available in Cal7507_4468 Calothrix sp. PCC 7507 MYSQQLRTAIYGFFKRSHHLQLNCIDLQLNCIDLQLSCIDLQLSCIDLQLSCIDLQLNCIDLQLSCIDLQLSCIDLQLSCIDLQLSCI...DLQLSCIDLQLSCIDLQLSCIDLQLSCIDLQLSCIDLQSLNYPFLHFTDSFFVVMGTLKI ...

Protein (Cyanobacteria): 518333301 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available othetical protein Pleurocapsa sp. PCC 7319 MKFDLNLLKVLPLATLSIALLAPGKIAEAAGGYGAETGYGAETSYGADAGHGPATGGYGAETGYGADAGHGPATGGYGAETGHGADA...GHGPATGGYGAETGYGADAGHGPATGGYGTDAGHGADAGHGSATGGYGADAGHGADAGHGPATGGYGADAGHGADAGHGADAGHGADAGHGADAGHGADAGHGADA...GHGADAGHGADAGHGADAAGGPLGIPEFLVSKKAQRIEFFSFLTAIGLGIIIPEFVYKPRKNSQSQNSSANQQEQTAEIKQDTPSLKVVSENTKTLSVAADNTEKSNNQDTIEFKNQSEQDQEDQKAA

Protein (Cyanobacteria): 516258751 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available 27:2058 ... hypothetical protein Geitlerinema sp. PCC 7105 MAVWKFALGSIAGVLVGTSPSLALPGQTVEEVQTWIQTNPLLPRGLEGSL...RVSRSDIPGQRFTFTALKTLPTDSNLVVGGRYIRSERLEVLDYENGVTRDRLVSTLRSIYDLDIYRDYRDAEVVYDYVSPAGREMQDVYRGVLLKGDRFGYWIEITEREGIEPVIGHLAIVLAEDVETLETQLRNR

Protein (Cyanobacteria): 516257059 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available 7:780 ... hypothetical protein Geitlerinema sp. PCC 7105 MSDKLEDFNGRNLDTKKSEGVERRKENRGKLLIDATVAPADIKYPTDVELLN...QARKTTELILDILYKSLKGQLYKKPRTHRKLARKEYLKFAKKRRPSRKERRNAVKKQLQYLQRNFRNIEKLIEKGASLECLSRRQYRNLLVSSEITRQQQWMWSNQ

Protein (Cyanobacteria): 504985034 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available ater-soluble carotenoid protein Geitlerinema sp. PCC 7407 MTQSLVPQQPVTQPLSAVASQFPVIQQYFDALNGETYPEAASLFEEAGVL...RAPFEQPVQGREAIAAYLSQEARGMVLQPDQGTVASTAYGAEITIQGKVQTRLFKVNVAWIFEVVSARSALASVQVKLLASPQELLKLRR

Protein (Cyanobacteria): 516255830 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available 7:918 ... hypothetical protein Geitlerinema sp. PCC 7105 MLYIYNHKLRRPSPLYIFKNFFESKAVENLLGEGIKAEYLNDDRLGRVLDKI...YRFGLNRIFVAIALATVKKYELTVNSNHLDSSSFHVHGDYPNSGESGTIEITYGYSRDHRPDLKQFLMNLICTGDGDVPLWMKMGSGNDSDSKQFGRSMVEFKKHFSLKV

Protein (Cyanobacteria): 648405821 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available 27:2531 ... hypothetical protein Geitlerinema sp. PCC 7105 MLMNIIFLTSAITTAAIATYFITHRLGGFRTVATLLCLGLLAGTGSLPAL...ASTDIAALGAKSNTLEQGQQQLEEDLKLTPTGGQYSGIEYAKGAERGEPMTDRKIRETILSDTSEDLTVNVASGSVILSGTVRDKDRAREIVDEIKGISGVHEITFELGLEEGQSS

Protein (Cyanobacteria): 516258198 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available 7:1853 ... hypothetical protein Geitlerinema sp. PCC 7105 MQKKYIVRLTAEERHQLQAVIKKLNGSSQKVRRAQILLKADADGPNWTDQQ...IAEAFDCRTKTVENIRRRLVEQGFEITLNGVKRTRPPTDKRLDGEQEAQVIAMRLGPPPAGYANWSLRLLARKVVELGLVEAVSHETVRQTLKKTG

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.

Protein (Cyanobacteria): 26322 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available n of unknown function DUF1830 Calothrix sp. PCC 6303 MAQILDSLPPEQSGKILCCYVNATSKIQVARITNIPNWYFERVVFPGQRLAFEAPRAAHLEIHTGMMASAILSDNIPCDRLVISEPSDPEPETNSTTEDENTCKNTIAPSIDNSTGDTPKNFKIAGLV ...

Protein (Cyanobacteria): 505001956 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available protein of unknown function DUF1818 Gloeocapsa sp. PCC 7428 MERVVKSGTGWRVGWNPHAAKYQALIGTDDWAIELTSAEFYDFCRLAVQLTEAIAQISQELMDEEKISCEAESDLVWMEVTGYPHAYSLHFILHTGRGVEGTWTPQAVPHLIQAVQMIQVF

Protein (Cyanobacteria): 427719678 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available ... hypothetical protein Cal7507_4468 Calothrix sp. PCC 7507 MYSQQLRTAIYGFFKRSHHLQLNCIDLQLNCIDLQLSCIDLQLSCIDLQLSCIDLQLNCIDLQLSCIDLQLSCI...DLQLSCIDLQLSCIDLQLSCIDLQLSCIDLQLSCIDLQLSCIDLQLSCIDLQSLNYPFLHFTDSFFVVMGTLKI

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

International Nuclear Information System (INIS)

Tiwari, D.N.; Singh, C.B.

1980-01-01

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

Protein (Cyanobacteria): 428297532 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available 0562:1027 ... hypothetical protein Cal6303_0799 Calothrix sp. PCC 6303 MSNLSHGGFDDSKPTIDENSFWQYIRSLHPQTVKQLNKPSSTDVVETINLTVATILDHISDDSSDSQIVTSHDELGMLLGSVMIDGYFLRNAEQRMELDHIFQELGTGGEQE

Protein (Cyanobacteria): 504986075 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available photosystem II reaction center protein Psb28 Geitlerinema sp. PCC 7407 MAQIQFSPGVSEAVIPDVRLTRARDGSSGTATFYFERPQALVGESNAEITGMYLVDEEGQVMTREVKAKFINGQPEALEATYIMRSSEEWDRFMRFMERYAEEHGLGFSKS

Protein (Cyanobacteria): 428223918 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available :617 ... hypothetical protein GEI7407_0462 Geitlerinema sp. PCC 7407 MEKIESLPIIGWREWLALPELGISAIKTKVDTGARSSALH...AFDLRRFCQAGQEWVRFTIHPYQHDLQQTVVATARVIDERQVRTSSGHTELRPVIHTPILLGGCQWPIEITLTNRDVMGFRMLLGRQAIRQRFLVDPGHSFLLSSLRLPLRSPTSRSQPL

Protein (Cyanobacteria): 422782 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available center protein PsaF subunit III Geitlerinema sp. PCC 7407 MRRLFALVLVVFLWIGFAPPASADVAGLTPCGDSPAFLQRAKNATTPGAK...ARFERYAESQVLCGPEGLPHLIVDGRLDHAGEFLIPGLLFLYIAGWIGWAGRSYIIAIRKEGNPEEKEIIIDIPLALKLSLAALAWPATALKEILSGEIAAKNEEITVSPR ...

Protein (Cyanobacteria): 428224977 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available :1268 ... hypothetical protein GEI7407_1530 Geitlerinema sp. PCC 7407 MAQLQRLDIVGDDGQTIEIFVEEKDAPVLATSPNRDGRP...SMGAGSPSVKMQQMQQVIRGYATYALNAFKDFSAAEVEEITLMFGVKLSASAGIPYIANGTTDSNLEVQVKCRFPAKDG

Protein (Cyanobacteria): 428225310 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available 848 ... peptidoglycan-binding domain 1 protein Geitlerinema sp. PCC 7407 MKLQTIFRLLTIAVGLLGGSFTQPAIAHSLASQQTS...PVLIATAYTDLTLPTLRQGDRGRSVELLQNILLDNGFLGAAGVRLGNPQGAIVDGIFGEITAAAIRDLQRRYEIPVTGQVNPTTWEVLDMYENPYRSPLPWKQ

Nitrogen-fixing cyanobacterium with a high phycoerythrin content.

Science.gov (United States)

Rodriguez, H; Rivas, J; Guerrero, M G; Losada, M

1989-03-01

The elemental and molecular composition, pigment content, and productivity of a phycoerythrin-rich nitrogen-fixing cyanobacterium-an Anabaena strain isolated from the coastal lagoon Albufera de Valencia, Spain-has been investigated. When compared with other heterocystous species, this strain exhibits similar chlorophyll a, carotene, and total phycobiliprotein contents but differs remarkably in the relative proportion of specific phycobiliproteins; the content of C-phycoerythrin amounts to 8.3% (versus about 1% in the other species) of cell dry weight. Absorption and fluorescence spectra of intact phycobilisomes isolated from this Anabaena sp. corroborate the marked contribution of phycoerythrin as an antenna pigment, a circumstance that is unusual for cyanobacteria capable of fixing N(2). The pigment content of cells is affected by variations in irradiance and cell density, these adaptive changes being more patent for C-phycoerythrin than for phycocyanins. The Anabaena strain is clumpy and capable of rapid flocculation. It exhibits outdoor productivities higher than 20 g (dry weight) m day during summer.

Komposit Nano TiO2 Dengan PCC, Zeolit atau Karbon Aktif Untuk Menurunkan Total Krom dan Zat Organik Pada Air Limbah Industri Penyamakan Kulit

Directory of Open Access Journals (Sweden)

Bumiarto Nugroho Jati

2012-04-01

Full Text Available Telah dilakukan penelitian untuk menurunkan total krom dan zat organik pada limbah industri penyamakan kulit dengan menggunakan nano TiO2 yang dikompositkan dengan adsorben karbon aktif, zeolit, dan precipitated calcium carbonate (PCC dalam suatu reaktor fotokatalitik yang disusun secara batch dan dilengkapi dengan 6 buah lampu UV dan magnetic stirrer. Penurunan kadar krom total diukur dengan menggunakan Atomic Absorption Spectro-photometer (AAS dan penurunan zat organik dianalisa dengan menggunakan titrasi permanganatometri. Hasil penelitian menunjukkan pengolahan terbaik untuk penurunan kadar krom total adalah dengan menggunakan komposit TiO2:PCC = 8:2 yang dapat menurunkan total krom hampir 100% pada menit ke-170 dengan konsentrasi awal 214,35 mg/L. Untuk penurunan kadar zat organik, pengolahan terbaik dengan menggunakan komposit TiO2:PCC = 9:1 yang dapat menurunkan kadar zat organik hingga 100% pada menit ke-180. 

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.

Protein (Cyanobacteria): 516255382 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available 7:713 ... 7-cyano-7-deazaguanine reductase Geitlerinema sp. PCC 7105 MSDLHSVSNSISENETAEAATEVKYGEREIQEGKLITFPN...PRVGRRYEIQITLPEFTCKCPFSGYPDFATIEITYVPDERVVELKAIKLYINSYRDRYISHEESANQILDDFVAACDPLEVRLKADFSPRGNVHTVIEVQHVKGDSL

Protein (Cyanobacteria): 428225641 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available 5:1771 ... hypothetical protein GEI7407_2207 Geitlerinema sp. PCC 7407 MKSLSLCVLLSAGVLSLGALPSQAMAPAELVETPPNHS...VAIHRSEGNCPAQVDLWVQSRYYEGGGEFSALVDTAAIAGRAVFLEAKQDFVEFAAPLKPQYASCYGYVVSSDEPQYNLWFYKGYVYFRFDLQSLPGRPLSEITSQAIIEDRPFMRWAIAD

Feasibility Report and Final Environmental Impact Statement, Wisconsin River at Portage, Wisconsin, Feasibility Study for Flood Control. Appendixes.

Science.gov (United States)

1983-12-01

practical. A second option is to purchase floodplain property in fee, demolish existing floodprone structures, and reuse the land for agriculture or other...Aphanizomenon flos- aguae (a blue-green alga) and Cocconeis sp. (a pennate diatom). Station 1 had fewer species and fewer individuals than did Stations 2 and 3...algae were present in-each 7° river during the summer sampling period. Blue-green algae (Anabaena sp. and Aphanizomenon flos- aguae ) were the most abundant

Protein (Cyanobacteria): 516255090 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available 7:572 ... 30S ribosomal protein S11 Geitlerinema sp. PCC 7105 MARQSGKKSGARKQKRHVPNGVAYIQSTFNNTIVTITDPRGETISWA...SAGSSGFKGAKKGTPYAAQTAAESAARRASDQGMRQIEVMVSGPGSGRETAIRAIQGAGLEITLIRDITPIPHNGCRPPKRRRV

Bioconversion of oil sludge into biomass of lipid metabolites for use as a source of biofuel

Science.gov (United States)

Shchemelinina, T. N.; Matistov, N. V.; Markarova, M. Yu; Anchugova, E. M.

2018-01-01

The possibilities for the generation of biofuel from the results of the accumulation of lipids in oil-contaminated environments were studied. This type of accumulation occurs in the biomass of yeast strains Rhodotorula sp. VKM Y-2993D; in bacteria like Pseudomonas libanensis B-3041D and in consortia of microalgal strains such as Acutodesmus obliquus Syko-A Ch-055-12, Chlorella sp. SYKO A Ch-011-10, Monoraphidium sp., and Anabaena sp. The most promising of these for processing petroleum hydrocarbons into biofuels was found to be the consortium of microalgal strains, the content of palmitic acid of which reached 49.0 %, thereby achieving a mid-range cetane number.

African Journal of Biotechnology - Vol 15, No 27 (2016)

African Journals Online (AJOL)

Optimization of biomass production of Acetobacter pasteurianus KU710511 as a potential starter for fruit vinegar production · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD ... Effect of pond depth and lining plastic color on growth and nitrogen fixing capacity of the cyanobacteria, Anabaena sp. E3 · EMAIL ...

Na(+) regulation by combined nitrogen in Azolla pinnata-Anabaena azollae symbiotic association during salt toxicity.

Science.gov (United States)

Singh, Satya S; Singh, Santosh K; Mishra, Arun K

2008-01-01

To study the regulation of Na(+) ion by combined-N sources in Azolla pinnata-Anabaena azollae, Na(+) influx, intracellular Na(+) and Na(+) efflux were investigated in the presence of different N-sources (N(2), NH(4)(+), NO(3)(-) and urea) and various NaCl concentrations. Sodium influx by Azolla pinnata fronds was minimum in the presence of NO(3)(-). Almost identical levels of intracellular sodium, although less than N(2) and NH(4)(+) incubated fronds were observed in the presence of NO(3)(-) and urea. Efflux of sodium was minimum in urea and NO(3)(-) grown fronds. A low residual sodium was observed in the fronds incubated in NO(3)(-) and urea supplemented media. Results suggest that nitrate and urea curtailed the entry of sodium, reduced salt toxicity maximally by maintaining the minimum level of sodium and also conserved energy due to slow influx and efflux of Na(+) within the fronds during salt shock and the process of adaptation.

Protein (Cyanobacteria): 504984120 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available photosystem I reaction center protein PsaF subunit III Geitlerinema sp. PCC 7407 MRRLFALVLVVFLWIGFAPPASADVA...GLTPCGDSPAFLQRAKNATTPGAKARFERYAESQVLCGPEGLPHLIVDGRLDHAGEFLIPGLLFLYIAGWIGWAGRSYIIAIRKEGNPEEKEIIIDIPLALKLSLAALAWPATALKEILSGEIAAKNEEITVSPR

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

United States Air Force Research on Airfield Pavement Repairs Using Precast Portland Cement Concrete (PCC) Slabs (BRIEFING SLIDES)

National Research Council Canada - National Science Library

Saeed, Athar

2008-01-01

...) slab repairs using precast PCC slab panels. AFRL is leading the technology development by critically reviewing the research conducted to date in this arena by the Air Force and the highway and civil aviation agencies and adopting...

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

Characterization of nifB, nifS, and nifU genes in the cyanobacterium Anabaena variabilis: NifB is required for the vanadium-dependent nitrogenase.

OpenAIRE

Lyons, E M; Thiel, T

1995-01-01

Anabaena variabilis ATCC 29413 is a heterotrophic, nitrogen-fixing cyanobacterium containing both a Mo-dependent nitrogenase encoded by the nif genes and V-dependent nitrogenase encoded by the vnf genes. The nifB, nifS, and nifU genes of A. variabilis were cloned, mapped, and partially sequenced. The fdxN gene was between nifB and nifS. Growth and acetylene reduction assays using wild-type and mutant strains indicated that the nifB product (NifB) was required for nitrogen fixation not only by...

Protein (Cyanobacteria): 123924 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available family enzyme, subfamily IA,REG-2-like HAD hydrolase, subfamily IA Leptolyngbya sp. PCC 7375 MTIPKVIFLDAVGTLFGVKGSVGEVYQALAQQAGVQASAH...ELDKAFYRSFAVANAMAFPGVPDVEIPHQEYLWWLAIAKDTFQRAGVFQEFSDFEVFFEGLYQHFATAAPWMVYQDTVNSLKR

ORF Alignment: NC_003272 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available ... - Nostoc sp. (strain PCC 7120) ... Length = 66 ... Query: 5 ... ESQTPVTLSDRELQIIDLVAAGLTNQEIAAKLEISKRTVDNHIS...NILDKTRTENRVALVR 64 ... ESQTPVTLSDRELQIIDLVAAGLTNQEIAAKLEISKRTVDNHISNILDKTRTENRVALVR Sbjct: 1 ... ESQTPVTLSDRELQIIDLVAAGLTNQEIAAKLEISKRTVDNHISNILDKTRTENRVALVR 60 ...

Seroprevalencia de Leptospira sp., Rickettsia sp. Ehrlichia sp. en trabajadores rurales del departamento de Sucre, Colombia Seroprevalence of Leptospira sp., Rickettsia sp. and Ehrlichia sp. in rural workers of Sucre, Colombia

Directory of Open Access Journals (Sweden)

Rodrigo Ríos

2008-06-01

Full Text Available Objective. Determinar la seroprevalencia de Leptospira sp., Rickettsia sp. y Ehrlichia sp. en trabajadores de áreas rurales del departamento de Sucre. Material y métodos. Se realizó un estudio escriptivo, prospectivo, de corte transversal, que pretendió determinar la seroprevalencia e Leptospira sp., Rickettsia sp. y Ehrlichia sp. en 90 trabajadores de áreas rurales del departamento de Sucre. Se estableció la presencia de anticuerpos séricos anti-IgM específicos anti-Leptospira por la técnica de ELISA indirecta. Para la determinación de Rickettsia sp. y Ehrlichia sp. se uso la técnica de inmunofluorescencia indirecta. Resultados. La población evaluada estaba compuesta por 27 (30% ordeñadores, 21 (23% jornaleros, 18 (20% profesionales del campo y 24 (27% que realizaban otras actividades. Ventidós (24% muestras resultaron positivas en alguna de las pruebas. De éstas, 12 (13,3% fueron positivas para Leptospira sp., 7 (7,8% para Rickettsia sp. y 3 (3,3% ara Ehrlichia sp. Conclusión. Este fue el primer estudio que se llevó a cabo en el departamento de Sucre y permitió demostrar que existe una prevalencia importante de Leptospira p.,Rickettsia sp. y Ehrlichia sp.. Los factores de riesgo ocupacional fueron factores determinantes en la seropositividad.Objective. To determine the seroprevalence of Leptospira sp., Rickettsia sp. and Ehrlichia sp. in agricultural workers of Sucre. Methods. A descriptive prospective cross-sectional study was conducted in ninety rural workers of Sucre. Presence of serum antibodies anti-IgM specific anti-Leptospira by indirect ELISA was established. For the determination of Rickettsia and Ehrlichia indirect inmunoflorescence was used. Results.The population was composed by 27 (30% milkers, 21 (23% day workers, 18 farm professionals (20% and 24 (26% workers in others activities. A total of 22 (24% samples were positive to some test. Twelve (13.3% were positive to Leptospira sp., seven (7.8% to Rickettsia sp

ORF Alignment: NC_003272 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available ... family [Nostoc sp. PCC 7120] ... Length = 102 ... Query: 48 ... IGIDLEYLRPTSD...LESLAKRFFLPREYELLRSLPDEQKQKIFFRYWTCKEAYLKATGDGI 107 ... IGIDLEYLRPTSDLESLAKRFFLPREYELLRSLPDEQ...KQKIFFRYWTCKEAYLKATGDGI Sbjct: 1 ... IGIDLEYLRPTSDLESLAKRFFLPREYELLRSLPDEQKQKIFFRYWTCKEAYLKATGDGI 60 ...

ORF Alignment: NC_000911 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available ... thioredoxin [Synechocystis sp. PCC 6803] ... Length = 92 ... Query: 2 ... SLLEITDAEFEQETQGQTKPVLVYFWASWCGPCRLMAPA...IQAIAKDYGDKLKVLKLEVDP 61 ... SLLEITDAEFEQETQGQTKPVLVYFWASWCGPCRLMAPA...IQAIAKDYGDKLKVLKLEVDP Sbjct: 1 ... SLLEITDAEFEQETQGQTKPVLVYFWASWCGPCRLMAPAIQAIAKDYGDKLKVLKLEVDP 60 ...

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

International Nuclear Information System (INIS)

Liu, Ting; Shuai, Yingli; Zhou, Honggang

2011-01-01

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 P4 1 2 1 2, 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 Å 3 Da −1

Localization and prediction of malignant potential in recurrent pheochromocytoma/paraganglioma (PCC/PGL) using 18F-FDG PET/CT.

Science.gov (United States)

Fikri, Ahmad Saad Fathinul; Kroiss, A; Ahmad, A Z F; Zanariah, H; Lau, W F E; Uprimny, C; Donnemiller, E; Kendler, D; Nordin, A J; Virgolini, I J

2014-06-01

To our knowledge, data are lacking on the role of 18F-FDG PET/CT in the localization and prediction of neuroendocrine tumors, in particular the pheochromocytoma/paraganglioma (PCC/PGL) group. To evaluate the role of 18F-FDG PET/CT in localizing and predicting the malignant potential of PCC/PGL. Twenty-three consecutive patients with a history of PCC/PGL, presenting with symptoms related to catecholamine excess, underwent 18F-FDG PET/CT. Final confirmation of the diagnosis was made using the composite references. PET/CT findings were analyzed on a per-lesion basis and a per-patient basis. Tumor SUVmax was analyzed to predict the dichotomization of patient endpoints for the local disease and metastatic groups. We investigated 23 patients (10 men, 13 women) with a mean age of 46.43 ± 3.70 years. Serum catecholamine levels were elevated in 82.60% of these patients. There were 136 sites (mean SUVmax: 16.39 ± 3.47) of validated disease recurrence. The overall sensitivities for diagnostic CT, FDG PET, and FDG PET/CT were 86.02%, 87.50%, and 98.59%, respectively. Based on the composite references, 39.10% of patients had local disease. There were significant differences in the SUVmax distribution between the local disease and metastatic groups; a significant correlation was noted when a SUVmax cut-off was set at 9.2 (Plocalization of recurrent tumors. Tumor SUVmax is a potentially useful predictor of malignant tumor potential. © The Foundation Acta Radiologica 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

ORF Alignment: NC_003272 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available stidine kinase ... [Nostoc sp. PCC 7120] ... Length = 73 ... Query: 410 ADLIQLNRLKDEFLACISH...ELKTPLTAVLGLSRLLVDQQLGELNERQARYAGLIHQSGRH 469 ... ADLIQLNRLKDEFLACISHELKTPLTAVLG...LSRLLVDQQLGELNERQARYAGLIHQSGRH Sbjct: 1 ... ADLIQLNRLKDEFLACISHELKTPLTAVLGLSRLLVDQQLGELNERQARYAGLIHQSGRH 60 ...

ORF Alignment: NC_000911 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available ... protein - Synechocystis sp. (strain PCC 6803) ... Length = 227 ... Query: 40 ... SRQTIIVATEPTFPPFEMTDE...ATGQLTGFDVDLIQAIGEAAQVTVDIQGYPFDGIIPALQ 99 ... SRQTIIVATEPTFPPFEMTDEATGQLTGFDVDLIQAIGEAAQVTVDIQGYPFDG...IIPALQ Sbjct: 1 ... SRQTIIVATEPTFPPFEMTDEATGQLTGFDVDLIQAIGEAAQVTVDIQGYPFDGIIPALQ 60

Protein (Cyanobacteria): 384770 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007109191.1 1117:24406 1150:4823 63132:1446 1173025:1446 dihydroneopterin aldolase Geit...lerinema sp. PCC 7407 MDRLQVCGIRCYGYTGFFEEERKLGQWFEVDLVFGLDVRAAGASDRLDDTLDYGGAVQRVQSLVRQARFATIERLATAIAEDILHHTVAEEVTVRLTKVSPPIPDFGGHIALEITRSRAELHPGT ...

Use of HPLC for the detection of iron chelators in cultures of bacteria, fungi, and algae

International Nuclear Information System (INIS)

Boyer, G.L.; Speirs, R.J.; Morse, P.D.

1990-01-01

Iron is essential for the growth of living cells. To meet biochemical needs, microorganisms, including algae, produce high affinity chelators termed siderophores. These compounds solubilize Fe and increase its bioavailability. We have developed a new method to study siderophore formation in cultured and natural environments. Based on the fact siderophores tightly bind 55-Fe, the radioactive complexes can be separated by HPLC using an inert PRP-1 column and detected by scintillation counting. This method cleanly resolves several known siderophores, including ferrichrome A, ferrichrome, desferal, and rhodotorulic acid. The optimization of the method and its use for analysis of siderophore formation in bacteria (E. coli, and Bacillus megaterium), fungi (Ustilago sphaerogena), and cyanobacteria (Anabaena flos-aqua UTEX 1444 and Anabaena sp. ATCC 27898) will be presented

ORF Alignment: NC_000911 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available ... slr2001 [Synechocystis sp. PCC 6803] ... Length = 228 ... Query: 10 ... LIIGGAEDKVHGREILQTFWSRSGGNDAIIGIIPSAS...REPLLIGERYQTIFSDMGVKELK 69 ... LIIGGAEDKVHGREILQTFWSRSGGNDAIIGIIPSAS...REPLLIGERYQTIFSDMGVKELK Sbjct: 1 ... LIIGGAEDKVHGREILQTFWSRSGGNDAIIGIIPSASREPLLIGERYQTIFSDMGVKELK 60 ... Quer

Protein (Cyanobacteria): 422295 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007108243.1 1117:25160 1150:6231 63132:809 1173025:809 iojap-like protein Geitle...rinema sp. PCC 7407 MMNFDTSDNRPTTSFEPLPTEAPVPSSDSQEAHELVKTIVEAAEDRKGAEITVLRVSEVSYLADYFVIVTGFSTTQVRAIARSIEAKVEEAWQRQPRKNEGINEGKWVLQDYGDVIVHVFMPQEREFYSLEAFWGHADRLTLPNLELAQEA ...

Protein (Cyanobacteria): 387469 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007107568.1 1117:24454 1150:5233 63132:9 1173025:9 3-dehydroquinate dehydratase Geit...lerinema sp. PCC 7407 MLSVLVLHGPNLNLLGLREPEVYGRSTLDDVNRLLEEEARSLQAEITALQSNHEGVLIDAIQAARGKHHGLLINPGAYTHTSVAIRDAIAGVAIPTVEVHLSNIHRREAFRHHSYIAPVAIGQISGFGVESYRLGLRALVAHLQSLDPA ...

Protein (Cyanobacteria): 302380 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007111107.1 1117:5803 1150:2099 63132:201 1173025:201 Methyltransferase type 11 Geit...lerinema sp. PCC 7407 MISSNHVLWQQQHVVDVRDAAFAARTYREHADVRALLRRVTGAERLQSACEVGAGYGRMTVVLTEFAEQVTGLERERHFVEEATRLLPEIT

Protein (Cyanobacteria): 504985318 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available WP_015172420.1 ... 1117:22013 ... 1150:56822 1301283:78524 ... 63132:1744 1173025:1864 ... ... hypothetical protein Geitlerinema sp. PCC 7407 MTTANFSHKDVAEITEAEVAALANRLEDDDYSSVFEGLEDWHLLRAIAFQRPELVEPYIHLLDLEAYDEA

Protein (Cyanobacteria): 504985975 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available WP_015173077.1 ... 1117:22894 ... 1150:58400 1301283:80278 ... 63132:3164 1173025:2236 ... ... hypothetical protein Geitlerinema sp. PCC 7407 MAKPWQKVLLAVALVGGVWGVSPAIAGTCASNCGPKPLQFIPGQQVKLQIINRTASIIEIQKVYGTDPVALRPGQEIT

Protein (Cyanobacteria): 504984488 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available WP_015171590.1 ... 1117:23095 ... 1150:57940 1301283:79766 ... 63132:2750 1173025:1386 ... ... hypothetical protein Geitlerinema sp. PCC 7407 MTQSSDSSTSQAKHQRSFAEWVSFAIAAAIIASVLGLVAYTWATGDTQPPVLETEITPEV

LOFT CIS analysis: 1''-PCC-76-A inside containment penetration S-1A. Internal technical report

International Nuclear Information System (INIS)

Nitzel, M.E.

1978-01-01

The stress analysis performed on the 1''-PCC-76-A piping system inside containment penetration S-1A is described. Deadweight, thermal expansion, and seismic loads were considered. Results of this analysis show that the subject piping system will meet ASME Boiler and Pressure Vessel Code, Section III, Class 2 requirements provided that supports S8 and S9 are installed as recommended

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.

ORF Alignment: NC_003272 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available bosomal protein L22 ... [Nostoc sp. PCC 7120] ... Length = 111 ... Query: 7 ... EVKAIARFIRMS...PYKVRRVLDQIRGLSYREALIILEFMPYRATEPVLTLLRSAAANAEHN 66 ... EVKAIARFIRMSPYKVRRVLDQIRG...LSYREALIILEFMPYRATEPVLTLLRSAAANAEHN Sbjct: 1 ... EVKAIARFIRMSPYKVRRVLDQIRGLSYREALIILEFMPYRATEPVLTLLRSAAANAEHN 60 ...

Protein (Cyanobacteria): 270085 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007109143.1 1117:4837 1150:2767 63132:154 1173025:154 response regulator receiver protein Geit...lerinema sp. PCC 7407 MTFKILLVEDDFLLARGTAKLLQRLGDHSVEITDDPATIFQRCESGEIDLVMMDVNLPGAQWEGHPVSGADLAQRLKTKSSTAHIPIIIVSAYAMLSERQTLLKVSLADEFCTKPITDYEALLRLIEELVARSPQVERLH ...

Protein (Cyanobacteria): 504983711 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available WP_015170813.1 ... 1117:4710 ... 1150:56664 1301283:78348 ... 63132:1601 1173025:861 ... hypothetical protein Geit...lerinema sp. PCC 7407 MGIKRQIEITPLHCIHPGKGLEICPLDQAATATHTNAEQPTWGHETTLVTLAPGTIEDLFVH

Protein (Cyanobacteria): 504983895 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available WP_015170997.1 ... 1117:21655 ... 1150:57681 1301283:79478 ... 63132:2517 1173025:996 ... hypothetical protein Geit...lerinema sp. PCC 7407 MFSSDLPEPDLLKTVLLPLLEDFQYWFGRSRSLLESEEITFLSQDQQADLLARVCQAQQEVMAAQALFNATDGQVGVETAALMPWHQLVTECWQVGMRLRTEKSRS

Protein (Cyanobacteria): 504984996 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available WP_015172098.1 ... 1117:412 ... 1150:57188 1301283:78930 ... 63132:2073 1173025:1687 ... cyanate lyase Geit...lerinema sp. PCC 7407 MSIPEITEKLLAAKKAKDMTFADLEQILGRDEVWIASVIYRQASASEEEAQKIVEALGLGPEVAIALTD

Protein (Cyanobacteria): 504983646 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available WP_015170748.1 ... 1117:22225 ... 1150:58729 1301283:80642 ... 63132:3460 1173025:812 ... hypothetical protein Geit...lerinema sp. PCC 7407 MASTYSFDIVSDFDRQELVNAIDQTTREIGTRYDLKDTKTTLELGEDEITVNTDSEFTLTA

Protein (Cyanobacteria): 504984487 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available WP_015171589.1 ... 1117:22124 ... 1150:57295 1301283:79049 ... 63132:217 1173025:1268 ... hypothetical protein Geit...lerinema sp. PCC 7407 MAQLQRLDIVGDDGQTIEIFVEEKDAPVLATSPNRDGRPSMGAGSPSVKMQQMQQVIRGYATYALNAFKDFSAAEVEEITLMFGVKLSASAGIPYIANGTTDSNLEVQVKCRFPAKDG

Protein (Cyanobacteria): 504985936 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available WP_015173038.1 ... 1117:4673 ... 1150:58391 1301283:80267 ... 63132:3156 1173025:2219 ... hypothetical protein Geit...lerinema sp. PCC 7407 MNKLLTLTVLGCVLSAAPAAIAAEWREITRNDVGDRFMIDTSSLDRRGSSVWFWEYRDFPQ

Protein (Cyanobacteria): 504983317 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available WP_015170419.1 ... 1117:23009 ... 1150:58655 1301283:80560 ... 63132:3394 1173025:527 ... hypothetical protein Geit...lerinema sp. PCC 7407 MAASDDFKQQIRDGNLSDALKLALSEAIHLEITTWVSSPEQGDRAAMPGSRMRTRINVVDG

Protein (Cyanobacteria): 504983362 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available WP_015170464.1 ... 1117:946 ... 1150:58664 1301283:80570 ... 63132:3401 1173025:562 ... hypothetical protein Geit...lerinema sp. PCC 7407 MTGFGAGESGQAPERSGFEPELGGFLRDAAQRSGLEPELGGVLRQRGVYVDEITCIGCKHCAH

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.

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

Persistence of Only a Minute Viable Population in Chlorotic Microcystis aeruginosa PCC 7806 Cultures Obtained by Nutrient Limitation.

Directory of Open Access Journals (Sweden)

Diogo de Abreu Meireles

Full Text Available Cultures from the cyanobacterial strain Microcystis aeruginosa PCC 7806 submitted to nutrient limitation become chlorotic. When returned to nutrient rich conditions these cultures regain their green colour. The aim of this study was to verify whether the cells in these cultures could be considered resting stages allowing the survival of periods of nutrient starvation as has been reported for Synechococcus PCC 7942. The experiments with Microcystis were carried out in parallel with Synechococcus cultures to rule out the possibility that any results obtained with Microcystis were due to our particular experimental conditions. The results of the experiments with Synechococcus PCC 7942 cultures were comparable to the reported in the literature. For Microcystis PCC 7806 a different response was observed. Analysis of chlorotic Microcystis cultures by flow cytometry showed that the phenotype of the cells in the population was not homogenous: the amount of nucleic acids was about the same in all cells but only around one percent of the population emitted red autofluorescence indicating the presence of chlorophyll. Monitoring of the reversion of chlorosis by flow cytometry showed that the re-greening was most likely the result of the division of the small population of red autofluorescent cells originally present in the chlorotic cultures. This assumption was confirmed by analysing the integrity of the DNA and the membrane permeability of the cells of chlorotic cultures. Most of the DNA of these cultures was degraded and only the autofluorescent population of the chlorotic cultures showed membrane integrity. Thus, contrary to what has been reported for other cyanobacterial genera, most of the cells in chlorotic Microcystis cultures are not resting stages but dead. It is interesting to note that the red autofluorescent cells of green and chlorotic cultures obtained in double strength ASM-1 medium differ with respect to metabolism: levels of emission of

Persistence of Only a Minute Viable Population in Chlorotic Microcystis aeruginosa PCC 7806 Cultures Obtained by Nutrient Limitation.

Science.gov (United States)

Meireles, Diogo de Abreu; Schripsema, Jan; Arnholdt, Andrea Cristina Vetö; Dagnino, Denise

2015-01-01

Cultures from the cyanobacterial strain Microcystis aeruginosa PCC 7806 submitted to nutrient limitation become chlorotic. When returned to nutrient rich conditions these cultures regain their green colour. The aim of this study was to verify whether the cells in these cultures could be considered resting stages allowing the survival of periods of nutrient starvation as has been reported for Synechococcus PCC 7942. The experiments with Microcystis were carried out in parallel with Synechococcus cultures to rule out the possibility that any results obtained with Microcystis were due to our particular experimental conditions. The results of the experiments with Synechococcus PCC 7942 cultures were comparable to the reported in the literature. For Microcystis PCC 7806 a different response was observed. Analysis of chlorotic Microcystis cultures by flow cytometry showed that the phenotype of the cells in the population was not homogenous: the amount of nucleic acids was about the same in all cells but only around one percent of the population emitted red autofluorescence indicating the presence of chlorophyll. Monitoring of the reversion of chlorosis by flow cytometry showed that the re-greening was most likely the result of the division of the small population of red autofluorescent cells originally present in the chlorotic cultures. This assumption was confirmed by analysing the integrity of the DNA and the membrane permeability of the cells of chlorotic cultures. Most of the DNA of these cultures was degraded and only the autofluorescent population of the chlorotic cultures showed membrane integrity. Thus, contrary to what has been reported for other cyanobacterial genera, most of the cells in chlorotic Microcystis cultures are not resting stages but dead. It is interesting to note that the red autofluorescent cells of green and chlorotic cultures obtained in double strength ASM-1 medium differ with respect to metabolism: levels of emission of red autofluorescence

Protein (Cyanobacteria): 118891 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007110526.1 1117:2337 1150:9795 63132:2205 1173025:2205 hypothetical protein GEI7407_3004 Geit...lerinema sp. PCC 7407 MNKLLTLTVLGCVLSAAPAAIAAEWREITRNDVGDRFMIDTSSLDRRGSSVWFWEYRDFPQPNNAFLEETVD

Protein (Cyanobacteria): 444358 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007109074.1 1117:25729 1150:9238 63132:1257 1173025:1257 hypothetical protein GEI7407_1530 Geit...lerinema sp. PCC 7407 MAQLQRLDIVGDDGQTIEIFVEEKDAPVLATSPNRDGRPSMGAGSPSVKMQQMQQVIRGYATYALNAFKDFSAAEVEEITLMFGVKLSASAGIPYIANGTTDSNLEVQVKCRFPAKDG ...

Protein (Cyanobacteria): 462887 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007109749.1 1117:35991 1150:9729 63132:1766 1173025:1766 hypothetical protein GEI7407_2218 Geit...lerinema sp. PCC 7407 MAEITDPEGEHRRIHWAAEQTDVATLINAYRGWYHWADAKEWASGAAFLRRLSQVGAGSPEAIALFIEQMNFHAQSRTKSGKYIYSAAKDALKALAEQGDPSAIAAWEEMQSSSEKP ...

Protein (Cyanobacteria): 334532 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007109075.1 1117:10916 1150:5016 63132:1375 1173025:1375 hypothetical protein GEI7407_1531 Geit...lerinema sp. PCC 7407 MTQSSDSSTSQAKHQRSFAEWVSFAIAAAIIASVLGLVAYTWATGDTQPPVLETEITPEVRQAGSQFYIPFSVTNTGGGTAESVQVIAELRVNGEVIETGEQQFDFLSGGEKAEGAFVFQRDPAQGDLSLRVASYSLP ...

Protein (Cyanobacteria): 428225487 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007109584.1 NC_019703 1117:412 ... 1150:57188 1301283:78930 ... 63132:2073 1173025:...1687 ... cyanate lyase Geitlerinema sp. PCC 7407 MSIPEITEKLLAAKKAKDMTFADLEQILGRDEVWIASVIYRQASASEEEAQKIVEALGLG

Protein (Cyanobacteria): 134448 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007108952.1 1117:2626 1150:6080 63132:1307 1173025:1307 hypothetical protein GEI7407_1406 Geit...lerinema sp. PCC 7407 MFQPSTVLPSSDRPVSHEIRYERSFLLDLKNLEPAVYQRVFQFVFQDKLTLTQIQEMPGFRQIYASPIFYRFELSDCLIGVEITGQIVKFLRVIPKPDI ...

Protein (Cyanobacteria): 504983657 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available WP_015170759.1 ... 1117:22502 ... 1150:57505 1301283:79283 ... 63132:2359 1173025:820 ... iojap family protein Geit...lerinema sp. PCC 7407 MMNFDTSDNRPTTSFEPLPTEAPVPSSDSQEAHELVKTIVEAAEDRKGAEITVLRVSEVSY

Protein (Cyanobacteria): 345257 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007108297.1 1117:12245 1150:7393 63132:850 1173025:850 hypothetical protein GEI7407_0747 Geit...lerinema sp. PCC 7407 MGIKRQIEITPLHCIHPGKGLEICPLDQAATATHTNAEQPTWGHETTLVTLAPGTIEDLFVHHFQTDQLLVVQ

Protein (Cyanobacteria): 40520 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007107948.1 1117:753 1150:5622 63132:560 1173025:560 hypothetical protein GEI7407_0395 Geit...lerinema sp. PCC 7407 MTGFGAGESGQAPERSGFEPELGGFLRDAAQRSGLEPELGGVLRQRGVYVDEITCIGCKHCAHVARNTFYIEPDY

Protein (Cyanobacteria): 261579 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007109407.1 1117:4756 1150:3024 63132:837 1173025:837 Peptidoglycan-binding domain 1 protein Geit...lerinema sp. PCC 7407 MKLQTIFRLLTIAVGLLGGSFTQPAIAHSLASQQTSPVLIATAYTDLTLPTLRQGDRGRSVELLQNILLDNGFLGAAGVRLGNPQGAIVDGIFGEITAAAIRDLQRRYEIPVTGQVNPTTWEVLDMYENPYRSPLPWKQ ...

Protein (Cyanobacteria): 4022 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007110171.1 1117:85 1150:6948 63132:2007 1173025:2007 hypothetical protein GEI7407_2646 Geit...lerinema sp. PCC 7407 MDPLFWLGLSILLVAVSLTALLFVAIPAFQELGRAARSAEKLFDTLNRELPPTLESIRLTGLEITELTEDVSDG

Protein (Cyanobacteria): 207028 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007109341.1 1117:3927 1150:1735 63132:1535 1173025:1535 hypothetical protein GEI7407_1805 Geit...lerinema sp. PCC 7407 MKIETRRFLLRDFIPADDAAFLAYHVEPRFAEFCSPAEITPSFNRNLLQQFNQWANEYPRHNYQLAIVSRRD

Removal of uranyl ions from residual waters using some algae types

International Nuclear Information System (INIS)

Cecal, Al.; Rudic, V.; Gulea, A.; Palamaru, I.; Humelnicu, D.; Salaru, V.V.; Popa, K.

1997-01-01

This paper deals with a study on the bioaccumulation of uranyl ions resulted from residual effluents, by means of some microbiological collectors: Scenedesmus quadricauda, Anabaena karakumica, Calothrix brevissima, Penicillium sp, as well as the Glucide extract of Porphyridium cruentum, in several experimental conditions. The retaining degree of the bioaccumulated uranyl ions, as well as the leaching degree, in HCl and H 2 O media, of the same ions previously retained on algae, were karakumica >Penicillium sp> Calothrix brevissima. The leaching effect of bioaccumulated uranyl ions is higher in hydrochloric acid then in water. (authors)

Protein (Cyanobacteria): 406385 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007108576.1 1117:24712 1150:4580 63132:1053 1173025:1053 LSU ribosomal protein L10P Geit...lerinema sp. PCC 7407 MGRTLEDKKAIVAELKETLSTAQMTFVIDYKGLSVSEITDLRNRLRPAGAVCKVTKNTLMRIAVDGSENWQPLTELLS

Protein (Cyanobacteria): 438962 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007108482.1 1117:25386 1150:6507 63132:985 1173025:985 Protein of unknown function DUF2605 Geit...lerinema sp. PCC 7407 MFSSDLPEPDLLKTVLLPLLEDFQYWFGRSRSLLESEEITFLSQDQQADLLARVCQAQQEVMAAQALFNATDGQVGVETAALMPWHQLVTECWQVGMRLRTEKSRS ...

Protein (Cyanobacteria): 109715 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007108354.1 1117:2126 1150:6302 63132:896 1173025:896 SSU ribosomal protein S11P Geit...lerinema sp. PCC 7407 MARQTKKTGAKKQKRNVPSGVAHIQSTFNNTIVTITAPNGEVISWASAGSSGFKGAKKGTPFAAQTASESAARRATDQGMRQIEVMVSGPGAGRETAIRALQGAGLEITLIRDVTPIPHNGCRPPKRRRV ...

Protein (Cyanobacteria): 343318 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007108232.1 1117:12067 1150:5751 63132:801 1173025:801 protein of unknown function DUF520 Geit...lerinema sp. PCC 7407 MASTYSFDIVSDFDRQELVNAIDQTTREIGTRYDLKDTKTTLELGEDEITVNTDSEFTLTAVHTILQTKAAK

Protein (Cyanobacteria): 405174 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007110665.1 1117:24697 1150:4821 63132:2039 1173025:2039 photosystem II reaction... center protein Psb28 Geitlerinema sp. PCC 7407 MAQIQFSPGVSEAVIPDVRLTRARDGSSGTATFYFERPQALVGESNAEITGMYLVDEEGQVMTREVKAKFINGQPEALEATYIMRSSEEWDRFMRFMERYAEEHGLGFSKS ...

Aquatic Studies of the Main Channel Border Habitat of Pool 5A on the Upper Mississippi River,

Science.gov (United States)

1984-01-01

result of Location 6 being shallow and sheltered, and thus easily affected by solar heating . 2-2 44 ct a: 0 5~ o; co 0 04 0 CS 0 4 Ls~ CD v, ICD 0 ’a Go0...upepnora maty Keribaud CYANOPHYTA (Blue-green Algae) *-Pinnuari nodsa (Ehrenberg) W. Smith Anabaena spp. inn ara SP __ p. p~hanizomenon flos- aguae

Protein (Cyanobacteria): 428777672 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007169459.1 NC_019779 1117:22154 ... 1118:7682 1301283:23924 92682:2160 ... 76023:2160 65093:2160 ... creatini...nase Halothece sp. PCC 7418 MLLHLQTWQEVEQYLEQSRGMIIPIGSTEQHGPTGLIGTDAICAEVIAKGVGENT

Protein (Cyanobacteria): 15634 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007110409.1 1117:287 1150:4700 63132:1220 1173025:1220 Proto-chlorophyllide reductase 57 kD subunit Geit...lerinema sp. PCC 7407 MSDACQWTPEAEARLKEIPFFVRPAARKKIEKFAQDAGITEITAEVYDQAKQKFGSN ...

Safety study of PCC 2140 and ALILOG 21 used as part of safety measurement systems

International Nuclear Information System (INIS)

Meriaux, Pierre; Adnot, Serge; Rayrolles, Catherine.

1978-03-01

The PCC 2140 and ALILOG 21 equipment may be used at C.E.A. or E.D.F., as part of safety measurement systems. In a study of a similar, but earlier equipment, it was noticed that certain types of failures caused the system to switch to the least sensitive measurement range, which was detrimental to safety. This report analyses failure modes leading to unsafe failures and evaluates the risks ran into taking in account tests during use [fr

Alterations in the antibacterial potential of Synechococcus spp. PCC7942 under the influence of UV-B radiations on skin pathogens

Directory of Open Access Journals (Sweden)

Nida Fatima

2017-11-01

Full Text Available Marine organisms are seen as a source of novel drugs and the discovery of new pharmaceutical is increasingly in demand. Cyanobacteria are regarded as a potential target for this as antibacterial, antiviral, antifungal, algicide and cytotoxic activities have been reported in these organisms. They have been identified as a new and rich source of bioactive compounds belonging to diversified groups. Radiation in the UV-B range interferes with various metabolic reactions by generating free radicals and active oxygen species. These deleterious compounds are inactivated by antioxidants. Among them are the carotenoids and phycocyanin which protect against photodynamic action in different ways. Stress plays an important role in the production of bioactive metabolites from organisms. Synechococcus spp. PCC7942 was studied for antibacterial activity against various pathogenic bacteria resistant to a number of available antibiotics after being exposed to UV-B radiation. The antibacterial activity of Synechococcus spp. PCC7942 was studied on five potent skin pathogens. The highest antibacterial activity was seen the methanol extracts of 24 h UV-B exposed cultures of Synechococcus spp. PCC7942. It can be concluded that there was moderate antibacterial activity. Results showed stress, solvent and dose-dependent activity. This antibacterial activity might be due to the enhanced synthesis of carotenoids and phycocyanin under UV-B stress. The purpose of the present study was to relate the inhibitory effects of the cyanobacterial compounds specifically on skin pathogens with exposure to UV-B radiation as UV protecting compounds are already reported in these organisms.

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

NARCIS (Netherlands)

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

2005-01-01

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

Protein (Cyanobacteria): 504995873 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available Hydrogenase-3 nickel incorporation protein HypA Microcoleus sp. PCC 7113 MHEVGIMQNTLDIALEYANRQGAAQIHRMTLRIGQ... WP_015182975.1 ... 1117:21745 ... 1150:36937 1301283:56429 ... 44471:3321 1173027:436 ...

Protein (Cyanobacteria): 504985265 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available poration protein HypA Geitlerinema sp. PCC 7407 MTKALLMTLHDWWESQPDRPKIDKVHLVVGQFTCV... WP_015172367.1 ... 1117:21745 ... 1150:57512 1301283:79291 ... 63132:2365 1173025:1620 ... hydrogenase nickel incor

Protein (Cyanobacteria): 504993053 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available Hydrogenase-3 nickel incorporation protein HypA Microcoleus sp. PCC 7113 MHETDMTKALIVTVRDWWEAQPEHPKISHIYLTVG... WP_015180155.1 ... 1117:21745 ... 1150:36937 1301283:56429 ... 44471:3321 1173027:436 ...

Protein (Cyanobacteria): 279234 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available ZP_09781866.1 1117:4884 1150:2505 35823:234 376219:95 putative Diguanylate cyclase with PAS/PAC and GAF sens...ors Arthrospira sp. PCC 8005 MNQLMEDRSKILWIAGNVGNDNHSLPQSILQNNGYEVHLVIGLKPAYNAIQSWP

Protein (Cyanobacteria): 279247 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available ZP_09782276.1 1117:4884 1150:2505 35823:234 376219:114 putative Diguanylate cyclase with PAS/PAC and GAF sen...sors Arthrospira sp. PCC 8005 MMDKYLCPCCSEPLLIHIIAHKKIGFCMNCHQEMPLIEQSRQMATVTEPVDVS

Protein (Cyanobacteria): 504928995 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available WP_015116097.1 ... 1117:4682 ... 1161:4218 ... 1162:3122 1177:1104 317936:3404 ... NADPH-d...ependent 7-cyano-7-deazaguanine reductase Nostoc sp. PCC 7107 MTQDTSEVKYGERNIAEGNLITFPNPRVGRRYDINITLPEFTCKCP

Protein (Cyanobacteria): 648410610 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available WP_026102361.1 NZ_KB235920 1117:21745 ... 52604:1915 ... 44474:816 118161:1544 ... hydrogenase nickel incorpora...tion protein HypA Pleurocapsa sp. PCC 7319 MHETDMTKALILTMKDWYVSQPEQRKIEKVHLIVGQFTCV

Protein (Cyanobacteria): 493566136 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available 29:4530 ... putative DNA alkylation repair enzyme Leptolyngbya sp. PCC 7375 MTAKDISKILRDLADPVIAEHSQRFFKTGKGEY... WP_006519474.1 NZ_JH993796 1117:18358 ... 1150:46430 1301283:66978 ... 47251:4271 1021

Protein (Cyanobacteria): 428299087 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007137393.1 NC_019751 1117:18359 ... 1161:10603 ... 1185:1278 1186:1626 32054:1873 1170562:1873 ... DNA alkyla...tion repair protein Calothrix sp. PCC 6303 MAQYLITQLQEQLAQADDSKTKEWWEAYLKHSLPFRGLKL

Protein (Cyanobacteria): 428298871 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007137177.1 NC_019751 1117:18359 ... 1161:10603 ... 1185:1278 1186:1626 32054:1873 1170562:1873 ... DNA alkyla...tion repair protein Calothrix sp. PCC 6303 MAQYLITQLQEQLAQAGDSKTKEWWEAYLKHSLPFRGLKL

Protein (Cyanobacteria): 275943 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007168782.1 1117:4879 1118:3357 92682:39 76023:39 65093:39 diguanylate cyclase with PAS/PAC and GAF senso...rs Halothece sp. PCC 7418 MDKYLARRTQDLRQQAQARLEQRERETDLNEMTPAELAHELEIHQTELEIQYEELQR

Protein (Cyanobacteria): 493968234 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available 1:1983 ... 7-cyano-7-deazaguanine reductase Cyanobium sp. PCC 7001 MTASHPPASSQGAPAAAASQAEPDGATRTPLYGERAIAEASL... WP_006911498.1 NZ_DS990557 1117:4682 ... 1118:6723 1301283:22859 ... 167375:1134 18028

Screening of Various Herbicide Modes of Action for Selective Control of Algae Responsible for Harmful Blooms

Science.gov (United States)

2009-01-01

included, Scenedesmus quadricauda and Selenastrum sp. After a two-week exposure period, all flasks were filtered. The planktonic algae were measured...activity against the various algal species tested (Figures 1 through 7). Aside from the reduction in biomass of the green alga Scenedesmus by...controls (Figures 1 through 7). Penoxsulam was highly active against the blue-greens Cylindrospermopsis and Anabaena, and the green alga Scenedesmus

Protein (Cyanobacteria): 285307 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available ith PAS/PAC and Chase2 sensors Nostoc sp. PCC 7107 MSKQLGKSFVSSNLNLNLKQLLDRKYRQLVVAFSVAVCIILLRSVGMFQSLELAGLD...YP_007048593.1 1117:4890 1161:684 1162:948 1177:381 317936:58 diguanylate cyclase w

Protein (Cyanobacteria): 286149 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_007068440.1 1117:4890 1161:684 1185:224 1186:169 99598:92 diguanylate cyclase with PAS/PAC and Chase2 sen...sors Calothrix sp. PCC 7507 MSKQLGKCLVKFIFGLKQSLGRGHRELITASSVVICILFLRSIGLLQFLELAALD

Protein (Cyanobacteria): 307154701 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available YP_003890085.1 NC_014501 1117:8352 ... 1118:3762 1301283:19569 ... 43988:641 497965:226 ... PAS/PAC and GAF sens...ors-containing diguanylate cyclase Cyanothece sp. PCC 7822 MWEFISNFLAPKSYIPHGHCYLWQ

New genome sequence data and molecular tools promote the use of photosynthetic and edible cyanobacteria in bioregenerative systems to support human space exploration.

Science.gov (United States)

Leys, Natalie; Morin, Nicolas; Janssen, Paul; Mergeay, Max

Cyanobacteria are daily used as nutritional supplements (e.g. Spirulina) and are considered for promising applications beyond Earth, in space, where they can play a crucial role in closed miniaturised biological waste recycling systems that are currently developed to support future long-term space missions. Cyanobacteria can be cultured with artificial light in controllable photobioreactors, and used for the efficient removal of CO2 from and production of O2 in the at-mosphere of the confined spacecraft, for removal of nitrate from waste water that is recycled to potable water, and as complementary food source. In this context, the filamentous cyanobac-terium Arthrospira sp. PCC 8005 was selected as part of the bio-regenerative life-support system MELiSSA from the European Space Agency. For bioprocess control and optimisation, the access to its genetic information and the development of molecular tools is crucial. Here we report on our efforts to determine the full genome of the cyanobacterium Arthrospira sp. PCC 8005. The obtained sequence data were analysed in detail to gain a better insight in the photosynthetic, nutritive, or potential toxic potential of this strain. In addition, the sensitivity of PCC 8005 to ionizing radiation was investigated because prolonged exposure of PCC 8005 to cosmic radiation in space might have a deleterious effect on its metabolism and oxygenic properties. To our knowledge, of the 6 different research groups across the globe trying to sequence Arthrospira strains, none of them, including us, were yet able to obtain a complete genome sequence. For Arthrospira sp. strain PCC 8005, we obtained 119 contigs (assembled in 16 scaffolds), representing 6,3 Mb, with 5,856 predicted protein-coding sequences (CDSs) and 176 genes encoding RNA. The PCC 8005 genome displays an unusual high number of large repeated sequences, covering around 8% of the genome, which likely hampered the sequenc-ing. The PCC 8005 genome is also ridden by mobile

Fertilizer effect Azolla - Anabaena in maize (Zea mays L.

Directory of Open Access Journals (Sweden)

Aldás-Jarrín Juan Carlos

2016-11-01

Full Text Available The deterioration of natural resources in agricultural activities, has motivated the search for new alternatives to enrich the soil with macro and micro nutrients sustainably, for the benefit of future generations, just as you think about the conservation and maintenance of water, avoiding eutrophication problems by the accumulation of fertilizers (nitrates and nitrites leached and deposited in natural sources, for this purpose they have been measured several agro ecological options that provide proper nutrition and a delicate ecological balance; in this investigation at field level in maize cultivation and different states it applied dose of azolla as a natural source of nitrogen to enrich the soil in the canton Cevallos, Tungurahua province. Anabaena floors of the town, based on the state of azolla and the level established for such preparation, the states of azolla. Six mixtures were prepared substrates azolla studied were: Dry A1 and A2 in the fresh state; the doses were established in relation to the volume of azolla against soil volume used: (0.5: 1 (0.75: 1 and (1: 1. The data collected were plant height and percentage of nitrogen in dry matter at 15, 30, 60 and 90 days. All this in order to establish the amount of nitrogen contributed by azolla as biofertilizer in growing corn. The best results were presented at the A1D3 (azolla dry-Dose 1: 1 treatment given plant height 15.02 cm at 15 days, 35.88 cm 30 days, 53.22 cm 60 66.12 days and 90 days; to 0.54% nitrogen percentage at 15 days, 0.90% at 30 days, 1.68% at 60 days and 2.08% after 90 days. In conclusion, the use of Azolla as a bio-fertilizer rich in nitrogen is feasible, as has been demonstrated in this research that the corn plant benefits from the contribution of this material, improving sustainable agricultural practices. It is recommended to expand this research in the same crop or other commercially important crops until the end of its production cycle, to report the results of

Nostoc thermotolerans sp. nov., a soil-dwelling species of Nostoc (Cyanobacteria).

Science.gov (United States)

Suradkar, Archana; Villanueva, Chelsea; Gaysina, Lira A; Casamatta, Dale A; Saraf, Aniket; Dighe, Gandhali; Mergu, Ratnaprabha; Singh, Prashant

2017-05-01

A filamentous, soil-dwelling cyanobacterial strain (9C-PST) was isolated from Mandsaur, Madhya Pradesh, India, and is described as a new species of the genus Nostoc. Extensive morphological and molecular characterization along with a thorough assessment of ecology was performed. The style of filament orientation, type and nature of the sheath (e.g. distribution and visibility across the trichome), and vegetative and heterocyte cell dimensions and shape were assessed for over one year using both the laboratory grown culture and the naturally occurring samples. Sequencing of the 16S rRNA gene showed 94 % similarity with Nostocpiscinale CENA21 while analyses of the secondary structures of the 16S-23S ITS region showed unique folding patterns that differentiated this strain from other species of Nostoc. The level of rbcl and rpoC1 gene sequence similarity was 91 and 94 % to Nostocsp. PCC 7524 and Nostocpiscinale CENA21, respectively, while the nifD gene sequence similarity was found to be 99 % with Nostocpiscinale CENA21. The phenotypic, ecological, genetic and phylogenetic observations indicate that the strain 9C-PST represents a novel species of the genus Nostoc with the name proposed being Nostoc thermotolerans sp. nov. according to the International Code of Nomenclature for Algae, Fungi, and Plants.

Small proteins in cyanobacteria provide a paradigm for the functional analysis of the bacterial micro-proteome.

Science.gov (United States)

Baumgartner, Desiree; Kopf, Matthias; Klähn, Stephan; Steglich, Claudia; Hess, Wolfgang R

2016-11-28

Despite their versatile functions in multimeric protein complexes, in the modification of enzymatic activities, intercellular communication or regulatory processes, proteins shorter than 80 amino acids (μ-proteins) are a systematically underestimated class of gene products in bacteria. Photosynthetic cyanobacteria provide a paradigm for small protein functions due to extensive work on the photosynthetic apparatus that led to the functional characterization of 19 small proteins of less than 50 amino acids. In analogy, previously unstudied small ORFs with similar degrees of conservation might encode small proteins of high relevance also in other functional contexts. Here we used comparative transcriptomic information available for two model cyanobacteria, Synechocystis sp. PCC 6803 and Synechocystis sp. PCC 6714 for the prediction of small ORFs. We found 293 transcriptional units containing candidate small ORFs ≤80 codons in Synechocystis sp. PCC 6803, also including the known mRNAs encoding small proteins of the photosynthetic apparatus. From these transcriptional units, 146 are shared between the two strains, 42 are shared with the higher plant Arabidopsis thaliana and 25 with E. coli. To verify the existence of the respective μ-proteins in vivo, we selected five genes as examples to which a FLAG tag sequence was added and re-introduced them into Synechocystis sp. PCC 6803. These were the previously annotated gene ssr1169, two newly defined genes norf1 and norf4, as well as nsiR6 (nitrogen stress-induced RNA 6) and hliR1(high light-inducible RNA 1) , which originally were considered non-coding. Upon activation of expression via the Cu 2+. responsive petE promoter or from the native promoters, all five proteins were detected in Western blot experiments. The distribution and conservation of these five genes as well as their regulation of expression and the physico-chemical properties of the encoded proteins underline the likely great bandwidth of small protein

An easy and efficient permeabilization protocol for in vivo enzyme activity assays in cyanobacteria

DEFF Research Database (Denmark)

Rasmussen, Randi Engelberth; Erstad, Simon Matthé; Ramos Martinez, Erick Miguel

2016-01-01

microbial cell factories. Better understanding of the activities of enzymes involved in the central carbon metabolism would lead to increasing product yields. Currently cell-free lysates are the most widely used method for determination of intracellular enzyme activities. However, due to thick cell walls...... used directly in the assays, the permeabilized cells exhibited the enzyme activities that are comparable or even higher than those detected for cell-free lysates. Moreover, the permeabilized cells could be stored at -20 °C without losing the enzyme activities. The permeabilization process...... for permeabilization of the cyanobacteria Synechococcus sp. PCC 7002 and Synechocystis sp. PCC 6803, and determination of two intracellular enzymes, ribulose-1,5-bisphosphate carboxylase/decarboxylase (Rubisco) and glucose-6-phosphate dehydrogenase (G6PDH), that play pivotal roles in the central carbon metabolism...

Recent developments in therapeutic applications of Cyanobacteria.

Science.gov (United States)

Raja, Rathinam; Hemaiswarya, Shanmugam; Ganesan, Venkatesan; Carvalho, Isabel S

2016-05-01

The cyanobacteria (blue-green algae) are photosynthetic prokaryotes having applications in human health with numerous biological activities and as a dietary supplement. It is used as a food supplement because of its richness in nutrients and digestibility. Many cyanobacteria (Microcystis sp, Anabaena sp, Nostoc sp, Oscillatoria sp., etc.) produce a great variety of secondary metabolites with potent biological activities. Cyanobacteria produce biologically active and chemically diverse compounds belonging to cyclic peptides, lipopeptides, fatty acid amides, alkaloids and saccharides. More than 50% of the marine cyanobacteria are potentially exploitable for extracting bioactive substances which are effective in killing cancer cells by inducing apoptotic death. Their role as anti-viral, anti-tumor, antimicrobial, anti-HIV and a food additive have also been well established. However, such products are at different stages of clinical trials and only a few compounds have reached to the market.

Protein (Cyanobacteria): 493967532 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available WP_006910818.1 NZ_DS990557 1117:3961 ... 1118:8120 1301283:24412 ... 167375:439 180281:1513 ... DNA internalizat...ion competence protein, ComEC/Rec2 family protein Cyanobium sp. PCC 7001 MLLGAVLPLG

Protein (Cyanobacteria): 493967295 [PGDBj - Ortholog DB

Lifescience Database Archive (English)

Full Text Available WP_006910587.1 NZ_DS990557 1117:3961 ... 1118:8120 1301283:24412 ... 167375:439 180281:1345 ... DNA internalizat...ion competence protein, ComEC/Rec2 family protein Cyanobium sp. PCC 7001 MWGALVLLVL

ORF Alignment: NC_000911 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available ... dbj|BAA10428.1| slr0204 [Synechocystis sp. PCC 6803] ... Length = 125 ... Query: 3 ... TFTYERQVYLADTDGAGVVYFNQFLQMCHEAYESWL...SSEHLSLQNIISVGDFALPLVHAS 62 ... TFTYERQVYLADTDGAGVVYFNQFLQMCHEAYESWL...SSEHLSLQNIISVGDFALPLVHAS Sbjct: 1 ... TFTYERQVYLADTDGAGVVYFNQFLQMCHEAYESWLSSEHLSLQNIISVGDFALPLVHAS 60 ... Query: 123 PLPQP 127 ... PLPQP Sbjct: 121 PLPQP 125

Silencing the SpMPK1, SpMPK2, and SpMPK3 Genes in Tomato Reduces Abscisic Acid—Mediated Drought Tolerance

Directory of Open Access Journals (Sweden)

Yan Liang

2013-11-01

Full Text Available Drought is a major threat to agriculture production worldwide. Mitogen-activated protein kinases (MAPKs play a pivotal role in sensing and converting stress signals into appropriate responses so that plants can adapt and survive. To examine the function of MAPKs in the drought tolerance of tomato plants, we silenced the SpMPK1, SpMPK2, and SpMPK3 genes in wild-type plants using the virus-induced gene silencing (VIGS method. The results indicate that silencing the individual genes or co-silencing SpMPK1, SpMPK2, and SpMPK3 reduced the drought tolerance of tomato plants by varying degrees. Co-silencing SpMPK1 and SpMPK2 impaired abscisic acid (ABA-induced and hydrogen peroxide (H2O2-induced stomatal closure and enhanced ABA-induced H2O2 production. Similar results were observed when silencing SpMPK3 alone, but not when SpMPK1 and SpMPK2 were individually silenced. These data suggest that the functions of SpMPK1 and SpMPK2 are redundant, and they overlap with that of SpMPK3 in drought stress signaling pathways. In addition, we found that SpMPK3 may regulate H2O2 levels by mediating the expression of CAT1. Hence, SpMPK1, SpMPK2, and SpMPK3 may play crucial roles in enhancing tomato plants’ drought tolerance by influencing stomatal activity and H2O2 production via the ABA-H2O2 pathway.

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

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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.

Ovos de Toxocara sp. e larvas de Ancylostoma sp. em praça pública de Lavras, MG Toxocara sp. eggs and Ancylostoma sp. larva in public parks, Brazil

Directory of Open Access Journals (Sweden)

Antônio Marcos Guimarães

2005-04-01

Full Text Available Larva migrans visceral e cutânea são zoonoses parasitárias causadas pela infecção da larva de Toxocara sp. e Ancylostoma sp., respectivamente. O objetivo do estudo foi verificar a contaminação por ovos de Toxocara sp. e ovos e larvas de Ancylostoma sp. em amostras de solos coletadas de praças públicas e de áreas de recreação infantil de Lavras, Estado de Minas Gerais, por meio da técnica de centrífugo-flutuação e do método de Baermann. A ocorrência de ovos de Toxocara sp. e, ovos e larvas de Ancylostoma sp. foi observada em 69,6% (16/23 das amostras de solo coletadas de praças públicas. A contaminação somente por ovos de Ancylostoma sp. em amostras de solo coletadas em escolas/creches foi de 22,2% (4/18. A percentagem de amostras de areia coletadas de escolas/creches contaminadas somente com larvas de Ancylostoma sp. foi de 11,1% (2/18. Praças públicas são as áreas com maior risco potencial de infecção por Toxocara sp. e Ancylostoma sp. Exame coproparasitológico realizado em 174 amostras de fezes de cães observou 58% e 23%, respectivamente, com ovos de Ancylostoma sp. e Toxocara sp.Visceral and cutaneous larva migrans are parasitic zoonoses caused by the infection of larval nematodes Toxocara sp. and Ancylostoma sp. respectively. The objective of this study was to investigate the contamination by Toxocara sp. eggs and Ancylostoma sp. eggs and larva of soil samples collected from public parks and children's playground areas in state of Minas Gerais, Brazil, using both Baermann's method and centrifugal flotation technique. Toxocara sp. and Ancylostoma sp. eggs were observed in soil samples collected from public squares in 17.4% (4/23 and 69.6 (16/23 respectively. In schools and child day care settings the contamination by Ancylostoma sp. larva in sand samples was 11.1% (2/18. Public parks are settings of more potential risk of Toxocara sp. eggs and Ancylostoma sp. infection. Stool parasitology testing of 174 stool

Effects of UV-B and heavy metals on nitrogen and phosphorus metabolism in three cyanobacteria.

Science.gov (United States)

Yadav, Shivam; Prajapati, Rajesh; Atri, Neelam

2016-01-01

Cyanobacteria sp. (diazotrophic and planktonic) hold a major position in ecosystem, former one due to their intrinsic capability of N2-fixation and later because of mineralization of organic matter. Unfortunately, their exposure to variety of abiotic stresses is unavoidable. Comparative analysis of interactive effect of UV-B and heavy metals (Cd/Zn) on nitrogen and phosphorus metabolism of three cyanobacteria (Anabaena, Microcystis, Nostoc) revealed additive inhibition (χ(2) significant p cyanobacteria suggests UV-B-induced structural change(s) in the enzyme/carriers. Metals seem to compete for the binding sites of the enzymes and carriers; as noticed for Anabaena and Microcystis showing change in Km while no change in the Km value of Nostoc suggests non-competitive nutrient uptake. Higher accumulation and more adverse effect on Na(+) and K(+) efflux proposes Cd as more toxic compared to Zn. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

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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.

Analysis of Combustion Process in Industrial Gas Engine with Prechamber-Based Ignition System

Directory of Open Access Journals (Sweden)

Rafał Ślefarski

2018-02-01

Full Text Available Application of a pre-combustion chamber (PCC ignition system is one of the methods to improve combustion stability and reduce toxic compounds emission, especially NOx. Using PCC allows the operation of the engine at lean combustion conditions or the utilization of low calorific gaseous fuels such as syngas or biogas. The paper presents the results of an experimental study of the combustion process in two stroke, large bore, stationary gas engine GMVH 12 equipped with two spark plugs (2-SP and a PCC ignition system. The experimental research has been performed during the normal operation of the engine in an industrial compression station. It was observed that application of PCC provides less cycle-to-cycle combustion variation (more than 10% and nitric oxide and carbon monoxide emissions decreased to 60% and 26% respectively. The total hydrocarbon (THC emission rate is 25% higher for the engine equipped with PCC, which results in roughly two percent engine efficiency decrease. Another important criterion of engine retrofitting was the PCC location in the engine head. The experimental results show that improvement of engine operating parameters was recorded only for a configuration with one port offset by 45° from the axis of the main chamber. The study of the ignition delay angle and equivalence ratio in PCC did not demonstrate explicit influence on engine performance.

Antibacterial Actions and Potential Phototoxic Effects of Volatile oils of Foeniculum sp. (fennel, Salvia sp. (sage, Vitis sp. (grape, Lavandula sp. (lavender

Directory of Open Access Journals (Sweden)

Elif Ayse Erdogan Eliuz

2016-09-01

Full Text Available In the present study, the volatile compounds of essential oil of Foeniculum vulgare (fennel, Salvia officinalis (sage, Vitis vinifera (grape, Lavandula angustifolia (lavender were analysed by gas chromatography-mass spectrometry (GC-MS using the Nist and Willey libraries. It was determined that the main components of Foeniculum sp. were anethole (41.11%, carvacrol (9.18%. whereas main components of Salvia sp were 1.8 cineole (34.09%, caryophyllene (10.95%, camphor (9.44%, α-pinene (8.42%. Vitis sp. contained linoleic acid (36.98%, 2,4-decadienal (30.79%. Finally, volatile component of Lavandula sp. was linalool (33.57%, linalyl acetate (30.74%. Photoxic antibacterial activity of volatile oil of those plants against Escherichia coli (ATCC 25293, Klebsiella pneumoniae (10031, Salmonella thyphimurium, Bacillus subtilis (ATCC 6633, Staphylococcus aureus (ATCC 25925, Enterococcus feacalis (ATCC 29212 were examined by using disc diffusion method. We demonstrated that volatile oil effectively can be activated by a standard LED light. In vitro, significant phototoxicity was demonstrated by volatile oil of Foeniculum sp. and Vitis sp. (P < 0.05, while minor phototoxicity was induced by Lavandula sp. Therefore, volatile oil of plant can be considered as a potential photosensitizer in the photochemical therapy.

Energy transfer in Anabaena variabilis filaments adapted to nitrogen-depleted and nitrogen-enriched conditions studied by time-resolved fluorescence.

Science.gov (United States)

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

2017-09-01

Nitrogen is among the most important nutritious elements for photosynthetic organisms such as plants, algae, and cyanobacteria. Therefore, nitrogen depletion severely compromises the growth, development, and photosynthesis of these organisms. To preserve their integrity under nitrogen-depleted conditions, filamentous nitrogen-fixing cyanobacteria reduce atmospheric nitrogen to ammonia, and self-adapt by regulating their light-harvesting and excitation energy-transfer processes. To investigate the changes in the primary processes of photosynthesis, we measured the steady-state absorption and fluorescence spectra and time-resolved fluorescence spectra (TRFS) of whole filaments of the nitrogen-fixing cyanobacterium Anabaena variabilis at 77 K. The filaments were grown in standard and nitrogen-free media for 6 months. The TRFS were measured with a picosecond time-correlated single photon counting system. Despite the phycobilisome degradation, the energy-transfer paths within phycobilisome and from phycobilisome to both photosystems were maintained. However, the energy transfer from photosystem II to photosystem I was suppressed and a specific red chlorophyll band appeared under the nitrogen-depleted condition.

Systems-Level Synthetic Biology for Advanced Biofuel Production

Energy Technology Data Exchange (ETDEWEB)

Ruffing, Anne [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jensen, Travis J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Strickland, Lucas Marshall [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Meserole, Stephen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Tallant, David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-03-01

Cyanobacteria have been shown to be capable of producing a variety of advanced biofuels; however, product yields remain well below those necessary for large scale production. New genetic tools and high throughput metabolic engineering techniques are needed to optimize cyanobacterial metabolisms for enhanced biofuel production. Towards this goal, this project advances the development of a multiple promoter replacement technique for systems-level optimization of gene expression in a model cyanobacterial host: Synechococcus sp. PCC 7002. To realize this multiple-target approach, key capabilities were developed, including a high throughput detection method for advanced biofuels, enhanced transformation efficiency, and genetic tools for Synechococcus sp. PCC 7002. Moreover, several additional obstacles were identified for realization of this multiple promoter replacement technique. The techniques and tools developed in this project will help to enable future efforts in the advancement of cyanobacterial biofuels.

Bradysia sp. em morangueiro Bradysia sp. in strawberry

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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.

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

NARCIS (Netherlands)

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

2003-01-01

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

Oxygen and the light-dark cycle of nitrogenase activity in two unicellular cyanobacteria

NARCIS (Netherlands)

Compaore, J.; Stal, L.J.

2010-01-01

Cyanobacteria capable of fixing dinitrogen exhibit various strategies to protect nitrogenase from inactivation by oxygen. The marine Crocosphaera watsonii WH8501 and the terrestrial Gloeothece sp. PCC6909 are unicellular diazotrophic cyanobacteria that are capable of aerobic nitrogen fixation. These

INTERAKSI ANTARA Trichoderma Harzianum, Penicillium SP. DAN Pseudomonas SP. SERTA KAPASITAS ANTAGONISMENYA TERHADAP Phytophthora CapsicilN VITRO*[Interaction Among Trichoderma Harzianum, Penicillium SP., Pseudomonas SP. and Antagonism Capacities Against Phy

OpenAIRE

Suharna, Nandang

2003-01-01

A preliminary study has been done to know antagonism capacities of three isolates of Trichoderma harzianum, two isolates of Penicillium sp.and one isolate of Pseudomonas sp.against Phytophthora capsici in vitro and interaction among those six antagonists.The highest antagonism capacity possessed by Penicillium sp. KN1, respectively followed by Penicillium sp.KN2,Pseudomonas sp. GH1 and the three T. harzianum isolates. Except for those three T. harzianum isolates, the two Penicillium sp.isolat...

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)

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

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

Differences in nutrient uptake capacity of the benthic filamentous algae Cladophora sp., Klebsormidium sp. and Pseudanabaena sp. under varying N/P conditions.

Science.gov (United States)

Liu, Junzhuo; Vyverman, Wim

2015-03-01

The N/P ratio of wastewater can vary greatly and directly affect algal growth and nutrient removal process. Three benthic filamentous algae species Cladophora sp., Klebsormidium sp. and Pseudanabaena sp. were isolated from a periphyton bioreactor and cultured under laboratory conditions on varying N/P ratios to determine their ability to remove nitrate and phosphorus. The N/P ratio significantly influenced the algal growth and phosphorus uptake process. Appropriate N/P ratios for nitrogen and phosphorus removal were 5-15, 7-10 and 7-20 for Cladophora sp., Klebsormidium sp. and Pseudanabaena sp., respectively. Within these respective ranges, Cladophora sp. had the highest biomass production, while Pseudanabaena sp. had the highest nitrogen and phosphorus contents. This study indicated that Cladophora sp. had a high capacity of removing phosphorus from wastewaters of low N/P ratio, and Pseudanabaena sp. was highly suitable for removing nitrogen from wastewaters with high N/P ratio. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

First report of Anisakis sp. in Epinephelus sp. in East Indonesia

OpenAIRE

Annytha Ina Rohi Detha; Diana Agustiani Wuri; Julianty Almet; Yuni Riwu; Christin Melky

2018-01-01

Objective: The present research was conducted to identify the prevalence of Anisakis sp. as fish-borne zoonoses in Epinephelus sp. in territorial waters of East Nusa Tenggara, Indonesia. Materials and methods: A total of 50 fish (Epinephelus sp.) were collected from Kupang Fish Market in East Nusa Tenggara. Identification of Anisakis sp. was performed based on morphological observations considering shape of ventriculus, boring tooth, and mucron using binocular microscope. Results: Prev...

Protection against salt toxicity in Azolla pinnata-Anabaena azollae symbiotic association by using combined-N sources.

Science.gov (United States)

Mishra, A K; Singh, Satya S

2006-09-01

Protection from salt stress was observed in the terms of yield (fresh and dry weight, chlorophyll and protein) and nitrogenase activity. Azollapinnata appeared highly sensitive to 40 mM external NaCl stress. Fronds of Azolla unable to grow beyond a concentration of 30 mM NaCl and accordingly death was recorded at 40 mM NaCl on the 6th day of incubation. Yield was inhibited by various levels of NaCl (0, 10, 20 and 30 mM). Addition of combined-N to the growth medium protected the association partially from salt toxicity. Among the N-sources (NO3-, NH4+ and urea) tried, urea mitigated the salt-induced toxicity most efficiently. Reduction in nitrogenase activity was observed when intact Azolla was grown in nutrient medium either supplemented with different levels of NaCl or combined nitrogen. Only NO3- (5 mM) protected the enzymatic activity from salt toxicity while other concentrations of ammonium, nitrate and urea slowed down the salt-induced inhibition of enzyme activity in Azolla-Anabaena association. These results suggested that an optimum protection from salt stress could be obtained by using a combination of combined nitrogen sources. The reason for this protection might be due to the availability of combined nitrogen to the association, nitrogen is only available through the biological nitrogen fixation which is the most sensitive to salt stress.

Relationship between sodium influx and salt tolerance of nitrogen-fixing cyanobacteria

Energy Technology Data Exchange (ETDEWEB)

Apte, S.K.; Reddy, B.R.; Thomas, J.

1987-08-01

The relationship between sodium uptake and cyanobacterial salt (NaCl) tolerance has been examined in two filamentous, heterocystous, nitrogen-fixing species of Anabaena. During diazotrophic growth at neutral pH of the growth medium, Anabaena sp. strain L-31, a freshwater strain, showed threefold higher uptake of Na+ than Anabaena torulosa, a brackish-water strain, and was considerably less salt tolerant (50% lethal dose of NaCl, 55 mM) than the latter (50% lethal dose of NaCl, 170 mM). Alkaline pH or excess K+ (more than 25 mM) in the medium causes membrane depolarization and inhibits Na+ influx in both cyanobacteria (S.K. Apte and J. Thomas, Eur. J. Biochem. 154:395-401, 1986). The presence of nitrate or ammonium in the medium caused inhibition of Na+ influx accompanied by membrane depolarization. These experimental manipulations affecting Na+ uptake demonstrated a good negative correlation between Na+ influx and salt tolerance. All treatments which inhibited Na+ influx (such as alkaline pH, K+ above 25 mM, NO3-, and NH4+), enhanced salt tolerance of not only the brackish-water but also the freshwater cyanobacterium. The results indicate that curtailment of Na+ influx, whether inherent or effected by certain environmental factors (e.g., combined nitrogen, alkaline pH), is a major mechanism of salt tolerance in cyanobacteria. (Refs. 27)

Computational analysis of LexA regulons in Cyanobacteria

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Su Zhengchang

2010-09-01

Full Text Available Abstract Background The transcription factor LexA plays an important role in the SOS response in Escherichia coli and many other bacterial species studied. Although the lexA gene is encoded in almost every bacterial group with a wide range of evolutionary distances, its precise functions in each group/species are largely unknown. More recently, it has been shown that lexA genes in two cyanobacterial genomes Nostoc sp. PCC 7120 and Synechocystis sp. PCC 6803 might have distinct functions other than the regulation of the SOS response. To gain a general understanding of the functions of LexA and its evolution in cyanobacteria, we conducted the current study. Results Our analysis indicates that six of 33 sequenced cyanobacterial genomes do not harbor a lexA gene although they all encode the key SOS response genes, suggesting that LexA is not an indispensable transcription factor in these cyanobacteria, and that their SOS responses might be regulated by different mechanisms. Our phylogenetic analysis suggests that lexA was lost during the course of evolution in these six cyanobacterial genomes. For the 26 cyanobacterial genomes that encode a lexA gene, we have predicted their LexA-binding sites and regulons using an efficient binding site/regulon prediction algorithm that we developed previously. Our results show that LexA in most of these 26 genomes might still function as the transcriptional regulator of the SOS response genes as seen in E. coli and other organisms. Interestingly, putative LexA-binding sites were also found in some genomes for some key genes involved in a variety of other biological processes including photosynthesis, drug resistance, etc., suggesting that there is crosstalk between the SOS response and these biological processes. In particular, LexA in both Synechocystis sp. PCC6803 and Gloeobacter violaceus PCC7421 has largely diverged from those in other cyanobacteria in the sequence level. It is likely that LexA is no longer a

Genetic diversity among and within cultured cyanobionts of diverse species of Azolla.

Science.gov (United States)

Sood, A; Prasanna, R; Prasanna, B M; Singh, P K

2008-01-01

The cyanobionts isolated from 10 Azolla accessions belonging to 6 species (Azolla mexicana, A. microphylla, A. rubra, A. caroliniana, A. filiculoides, A. pinnata) were cultured under laboratory conditions and analyzed on the basis of whole cell protein profiles and molecular marker dataset generated using repeat sequence primers (STRR(mod) and HipTG). The biochemical and molecular marker profiles of the cyanobionts were compared with those of the free-living cyanobacteria and symbiotic Nostoc strains from Anthoceros sp., Cycas sp. and Gunnera monoika. Cluster analysis revealed the genetic diversity among the selected strains, and identified 3 distinct clusters. Group 1 included cyanobionts from all the 10 accessions of Azolla, group 2 comprised all the symbiotic Nostoc strains, while group 3 included the free-living cyanobacteria belonging to the genera Nostoc and Anabaena. The interrelationships among the Azolla cyanobionts were further revealed by principal component analysis. Cyanobionts from A. caroliniana-A. microphylla grouped together while cyanobionts associated with A. mexicana-A. filiculoides along with A. pinnata formed another group. A. rubra cyanobionts had intermediate relationship with both the subgroups. This is the first study analyzing the diversity existing among the cultured cyanobionts of diverse Azolla species through the use of biochemical and molecular profiles and also the genetic distinctness of these free-living cyanobionts as compared to cyanobacterial strains of the genera Anabaena and Nostoc.

STRUCTURA TAXONOMICĂ ŞI ECOLOGICĂ A ALGOFLOREI EDAFICE DIN SERELE SATULUI CHIŞTELNIŢA, RAIONUL TELENEŞTI

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Alina TROFIM

2016-02-01

Full Text Available În articol sunt redate particularităţile structurale ale algoflorei edafice din serele s. Chiştelniţa. Structura taxonomică este constituită din 53 de specii şi varietăţi intraspecifice de alge, care aparţin la 31 genuri, 22 familii, 16 ordine şi 7 clase, dintre care cea mai înaltă diversitate au clasele Hormogoniophyceae – cu 16 specii şi Xanthophyceae – cu 14 specii. Carac­te­ristica ecologică a algoflorei demonstrează predominarea ecobiomorfelor P, care sunt lipsite de heterocisteşi răspân­dite printre particulele de sol sau se dezvoltă la suprafaţa lui. În algoflora solurilor au fost depistate 4 specii ce aparţin ecobio­morfei CF şi sunt azotfixatoare: Anabaena sp., Cylindrospermum licheniforme (Bory. Kütz., Nostoc linckia (Roth. Born. et Flah. şi Nostoc sp., care, în conformitate cu datele din literatura de specialitate, reprezintă tulpini de perspectivă pentru promovarea agriculturii ecologice. TAXONOMIC AND ECOLOGICAL STRUCTURE OF EDAPHICAL ALGAL FLORA FROM GREENHOUSE OF VILLAGE CHISTELNITA, DISTRICT TELENESTIIn this article are presented structural features of edaphical algal flora of greenhouses from village Chistelnita. Taxonomic structure consists of 53 species and varieties of algae belonging to 31 genera, 22 families, 16 orders and 7 classes, of which the highest diversity have Hormogoniophyceae and Xanthophyceae classes, with 16 and 14 species. Ecological characteristics of algal flora demonstrates the predominance of P ecobiomorphic, which are devoid of heterocyst and spread through the particles of ground or on the surface of it. In soils algal flora were discovered four species belonging to CF ecobiomorphic and they are nitrogen fixing: Anabaena sp., Cylindrospermum licheniforme (Bory. Kutz., Nostoc linckia (Roth. Born. et Flah. and Nostoc sp., which according to data from the literature, is promising strains for promoting organic farming. 

Penicillium araracuarense sp. nov., Penicillium elleniae sp. nov., Penicillium penarojense sp. nov., Penicillium vanderhammenii sp. nov. and Penicillium wotroi sp. nov., isolated from leaf litter.

Science.gov (United States)

Houbraken, Jos; López-Quintero, Carlos A; Frisvad, Jens C; Boekhout, Teun; Theelen, Bart; Franco-Molano, Ana Esperanza; Samson, Robert A

2011-06-01

Several species of the genus Penicillium were isolated during a survey of the mycobiota of leaf litter and soil in Colombian Amazon forest. Five species, Penicillium penarojense sp. nov. (type strain CBS 113178(T) = IBT 23262(T)), Penicillium wotroi sp. nov. (type strain CBS 118171(T) = IBT 23253(T)), Penicillium araracuarense sp. nov. (type strain CBS 113149(T) = IBT 23247(T)), Penicillium elleniae sp. nov. (type strain CBS 118135(T) = IBT 23229(T)) and Penicillium vanderhammenii sp. nov. (type strain CBS 126216(T) = IBT 23203(T)) are described here as novel species. Their taxonomic novelty was determined using a polyphasic approach, combining phenotypic, molecular (ITS and partial β-tubulin sequences) and extrolite data. Phylogenetic analyses showed that each novel species formed a unique clade for both loci analysed and that they were most closely related to Penicillium simplicissimum, Penicillium janthinellum, Penicillium daleae and Penicillium brasilianum. An overview of the phylogeny of this taxonomically difficult group is presented, and 33 species are accepted. Each of the five novel species had a unique extrolite profile of known and uncharacterized metabolites and various compounds, such as penicillic acid, andrastin A, pulvilloric acid, paxillin, paspaline and janthitrem, were commonly produced by these phylogenetically related species. The novel species had a high growth rate on agar media, but could be distinguished from each other by several macro- and microscopical characteristics.

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

NARCIS (Netherlands)

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

2002-01-01

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

Dicty_cDB: Contig-U16081-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available 1291 |pid:none) Cyanothece sp. PCC 7424, comple... 81 4e-37 AJ535197_1( AJ535197 |pid:none) Propionibacterium freud...eumoniae 342, comp... 75 4e-32 AJ535196_1( AJ535196 |pid:none) Propionibacterium freudenreichii s... 72 4e-3

Phylogenetic and taxonomic position of the genus Wollea with the description of Wollea salina sp. nov. (Cyanobacteria, Nostocales).

Czech Academy of Sciences Publication Activity Database

Kozlíková-Zapomělová, Eliška; Chatchawan, T.; Kaštovský, J.; Komárek, Jiří

2016-01-01

Roč. 16, č. 1 (2016), s. 43-55 ISSN 1802-5439 R&D Projects: GA ČR GAP506/12/1818; GA ČR(CZ) GA14-18067S; GA ČR(CZ) GA15-11912S Institutional support: RVO:60077344 ; RVO:67985939 Keywords : Anabaena * Cyanobacteria * ecology * molecular analyses * morphology * polyphasic approach * taxonomy * Wollea Subject RIV: EF - Botanics Impact factor: 1.350, year: 2016

Accessibility controls selective degradation of photosystem II subunits by FtsH protease

Czech Academy of Sciences Publication Activity Database

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

2015-01-01

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

Fatty acid composition of Spirulina sp., Chlorella sp. and Chaetoceros sp. microalgae and introduction as potential new sources to extinct omega 3 and omega 6

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Homan Gorjzdadeh

2016-05-01

Full Text Available Background: This study was carried out to determine the oil fatty acids from two special species of microalgae; Spirulina sp.,Chlorella sp. and also Chaetoceros sp. collected from Bahmanshir River. Materials and Methods: Sampling of microalgae Chaetoceros sp. from Bahmanshir River was under taken using bottle samplers during spring season of 2013. Microalgae Spirulina sp. and Chlorella sp. were supplied from Shrimp Research Institute of Iran in Bushehr Province. Samples then were cultured under controlled laboratory conditions and mass culture for 100 liters was undertaken. Isolation of microalgae species from water of cultured media was carried out using filtration and centrifugation methods. The fatty acid compositions were determined by Gas – FID chromatography. Results: Results showed that regarding Saturated Fatty Acids (SFA obtained from purified culture of Chaetoceros sp., Spirulina sp. and Chlorella sp. the maximum amount of total fatty acids were belonged to palmitic acids (C16:0 with 15.21%, 30.1% and 25.17% of total fatty acids  respectively. Analysis of Mono Unsaturated Fatty Acids (MUFA showed that in the Oleic acid was maximum amount of 34% in Spirulina sp. In addition the amount of MUFA in Chlorella sp. was 16.37% of total fatty acids. On the other hand the amount of palmeotic acid in purified culture of Chaetoceros sp. was 30.33% from total content of fatty acids. Analysis of Poly Unsaturated Fatty Acids (PUFA, Linoleic acid (C18:2 (Omega 6, revealed maximum percentage in Spirulina sp. with 18.8%. Results of Alpha linoleic acid (C18:3 (Omega3 analysis showed maximum amount of 9.66% in Chlorella sp. compared to other microalgae with lower omega 3 contents. Spirulina sp. contained maximum amount of Linoleic acid (C18:2 with 18.8% of total fatty acids. Therefore, Spirulina sp. can be considered as a rich source of omega 6 for the purpose of fatty acid extractions. The presence of PUFA in Chlorella sp. and Spirulina sp. was

Different activation of opercular and posterior cingulate cortex (PCC) in patients with complex regional pain syndrome (CRPS I) compared with healthy controls during perception of electrically induced pain: a functional MRI study.

Science.gov (United States)

Freund, Wolfgang; Wunderlich, Arthur P; Stuber, Gregor; Mayer, Florian; Steffen, Peter; Mentzel, Martin; Weber, Frank; Schmitz, Bernd

2010-05-01

Although the etiology of complex regional pain syndrome type 1 (CRPS 1) is still debated, many arguments favor central maladaptive changes in pain processing as an important causative factor. To look for the suspected alterations, 10 patients with CRPS affecting the left hand were explored with functional magnetic resonance imaging during graded electrical painful stimulation of both hands subsequently and compared with healthy participants. Activation of the anterior insula, posterior cingulate cortex (PCC), and caudate nucleus was seen in patients during painful stimulation. Compared with controls, CRPS patients had stronger activation of the PCC during painful stimulation of the symptomatic hand. The comparison of insular/opercular activation between controls and patients with CRPS I during painful stimulation showed stronger (posterior) opercular activation in controls than in patients. Stronger PCC activation during painful stimulation may be interpreted as a correlate of motor inhibition during painful stimuli different from controls. Also, the decreased opercular activation in CRPS patients shows less sensory-discriminative processing of painful stimuli.These results show that changed cerebral pain processing in CRPS patients is less sensory-discriminative but more motor inhibition during painful stimuli. These changes are not limited to the diseased side but show generalized alterations of cerebral pain processing in chronic pain patients.

Isolation Of PS II Nanoparticles And Oxygen Evolution Studies In Synechococcus Spp. PCC 7942 Under Heavy Metal Stress

Science.gov (United States)

Ahmad, Iffat Zareen; Sundaram, Shanthy; Tripathi, Ashutosh; Soumya, K. K.

2009-06-01

The effect of heavy metals was seen on the oxygen evolution pattern of a unicellular, non-heterocystous cyanobacterial strain of Synechococcus spp. PCC 7942. It was grown in a BG-11 medium supplemented with heavy metals, namely, nickel, copper, cadmium and mercury. Final concentrations of the heavy metal solution used in the culture were 0.1, 0.4 and 1 μM. All the experiments were performed in the exponential phase of the culture. Oxygen-evolving photosystem II (PS II) particles were purified from Synechococcus spp. PCC 7942 by a single-step Ni2+-affinity column chromatography after solubilization of thylakoid membranes with sucrose monolaurate. Oxygen evolution was measured with Clark type oxygen electrode fitted with a circulating water jacket. The light on the surface of the vessel was 10 w/m2. The cultures were incubated in light for 15 minutes prior to the measurement of oxygen evolution. Oxygen evolution was measured in assay mixture containing phosphate buffer (pH-7.5, 0.1 M) in the presence of potassium ferricyanide as the electron acceptor. The preparation from the control showed a high oxygen-evolving activity of 2, 300-2, 500 pmol O2 (mg Chl)-1 h-1 while the activity was decreased in the cultures grown with heavy metals. The inhibition of oxygen evolution shown by the organism in the presence of different metals was in the order Hg>Ni>Cd>Cu. Such heavy metal resistant strains will find application in the construction of PS II- based biosensors for the monitoring of pollutants.

A homozygous recA mutant of Synechocystis PCC6803: construction strategy and characteristics eliciting a novel RecA independent UVC resistance in dark.

Science.gov (United States)

Minda, Renu; Ramchandani, Jyoti; Joshi, Vasudha P; Bhattacharjee, Swapan Kumar

2005-12-01

We report here the construction of a homozygous recA460::cam insertion mutant of Synechocystis sp. PCC 6803 that may be useful for plant molecular genetics by providing a plant like host free of interference from homologous recombination. The homozygous recA460::cam mutant is highly sensitive to UVC under both photoreactivating and non-photoreactivating conditions compared to the wild type (WT). The liquid culture of the mutant growing in approximately 800 lx accumulates nonviable cells to the tune of 86% as estimated by colony counts on plates incubated at the same temperature and light intensity. The generation time of recA mutant in standard light intensity (2,500 lx) increases to 50 h compared to 28 h in lower light intensity (approximately 800 lx) that was used for selection, thus explaining the earlier failures to obtain a homozygous recA mutant. The WT, in contrast, grows at faster rate (23 h generation time) in standard light intensity compared to that at approximately 800 lx (26 h). The Synechocystis RecA protein supports homologous recombination during conjugation in recA (-) mutant of Escherichia coli, but not the SOS response as measured by UV sensitivity. It is suggested that using this homozygous recA460::cam mutant, investigations can now be extended to dissect the network of DNA repair pathways involved in housekeeping activities that may be more active in cyanobacteria than in heterotrophs. Using this mutant for the first time we provide a genetic evidence of a mechanism independent of RecA that causes enhanced UVC resistance on light to dark transition.

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

NARCIS (Netherlands)

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

1994-01-01

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

Eficiencia de pseudomonas sp, rhodopseudomonas sp, micrococcus sp y bacillus sp empleados como cultivos individuales y en consorcio, en la degradación de petróleo diesel ii

OpenAIRE

Otiniano García, Nélida Milly Esther

2010-01-01

In order to evaluate the efficiency of Pseudomonas sp, Rhodopseudomonas sp, Micrococcus sp, Bacillus sp, and the consortium formed by these four microorganisms in the diesel II petroleum degradation, it was worked in 5 bioreactors of aerated and shaken tank of 1.5 litters of capacity, with speed agitation of 120 rpm, and air flow of 0.5 vvm; in which were placed; 940 mL of Minimum Broth of Davies pH 7.0; 50 mL of diesel II petroleum as source of carbon and 10 mL of a suspension of approx...

Selection of bioindicators to detect lead pollution in Ebro delta microbial mats, using high-resolution microscopic techniques

Energy Technology Data Exchange (ETDEWEB)

Maldonado, J.; Sole, A.; Puyen, Z.M. [Departament de Genetica i Microbiologia, Facultat de Biociencies, Universitat Autonoma de Barcelona, Edifici C, Campus de la UAB, Cerdanyola del Valles, Bellaterra (Spain); Esteve, I., E-mail: isabel.esteve@uab.cat [Departament de Genetica i Microbiologia, Facultat de Biociencies, Universitat Autonoma de Barcelona, Edifici C, Campus de la UAB, Cerdanyola del Valles, Bellaterra (Spain)

2011-07-15

Lead (Pb) is a metal that is non-essential to any metabolic process and, moreover, highly deleterious to life. In microbial mats - benthic stratified ecosystems - located in coastal areas, phototrophic microorganisms (algae and oxygenic phototrophic bacteria) are the primary producers and they are exposed to pollution by metals. In this paper we describe the search for bioindicators among phototrophic populations of Ebro delta microbial mats, using high-resolution microscopic techniques that we have optimized in previous studies. Confocal laser scanning microscopy coupled to a spectrofluorometric detector (CLSM-{lambda}scan) to determine in vivo sensitivity of different cyanobacteria to lead, and scanning electron microscopy (SEM) and transmission electron microscopy (TEM), both coupled to energy dispersive X-ray microanalysis (EDX), to determine the extra- and intracellular sequestration of this metal in cells, were the techniques used for this purpose. Oscillatoria sp. PCC 7515, Chroococcus sp. PCC 9106 and Spirulina sp. PCC 6313 tested in this paper could be considered bioindicators for lead pollution, because all of these microorganisms are indigenous, have high tolerance to high concentrations of lead and are able to accumulate this metal externally in extracellular polymeric substances (EPS) and intracellularly in polyphosphate (PP) inclusions. Experiments made with microcosms demonstrated that Phormidium-like and Lyngbya-like organisms selected themselves at the highest concentrations of lead assayed. In the present study it is shown that all cyanobacteria studied (both in culture and in microcosms) present PP inclusions in their cytoplasm and that these increase in number in lead polluted cultures and microcosms. We believe that the application of these microscopic techniques open up broad prospects for future studies of metal ecotoxicity.

Selection of bioindicators to detect lead pollution in Ebro delta microbial mats, using high-resolution microscopic techniques

International Nuclear Information System (INIS)

Maldonado, J.; Sole, A.; Puyen, Z.M.; Esteve, I.

2011-01-01

Lead (Pb) is a metal that is non-essential to any metabolic process and, moreover, highly deleterious to life. In microbial mats - benthic stratified ecosystems - located in coastal areas, phototrophic microorganisms (algae and oxygenic phototrophic bacteria) are the primary producers and they are exposed to pollution by metals. In this paper we describe the search for bioindicators among phototrophic populations of Ebro delta microbial mats, using high-resolution microscopic techniques that we have optimized in previous studies. Confocal laser scanning microscopy coupled to a spectrofluorometric detector (CLSM-λscan) to determine in vivo sensitivity of different cyanobacteria to lead, and scanning electron microscopy (SEM) and transmission electron microscopy (TEM), both coupled to energy dispersive X-ray microanalysis (EDX), to determine the extra- and intracellular sequestration of this metal in cells, were the techniques used for this purpose. Oscillatoria sp. PCC 7515, Chroococcus sp. PCC 9106 and Spirulina sp. PCC 6313 tested in this paper could be considered bioindicators for lead pollution, because all of these microorganisms are indigenous, have high tolerance to high concentrations of lead and are able to accumulate this metal externally in extracellular polymeric substances (EPS) and intracellularly in polyphosphate (PP) inclusions. Experiments made with microcosms demonstrated that Phormidium-like and Lyngbya-like organisms selected themselves at the highest concentrations of lead assayed. In the present study it is shown that all cyanobacteria studied (both in culture and in microcosms) present PP inclusions in their cytoplasm and that these increase in number in lead polluted cultures and microcosms. We believe that the application of these microscopic techniques open up broad prospects for future studies of metal ecotoxicity.

Selection of bioindicators to detect lead pollution in Ebro delta microbial mats, using high-resolution microscopic techniques.

Science.gov (United States)

Maldonado, J; Solé, A; Puyen, Z M; Esteve, I

2011-07-01

Lead (Pb) is a metal that is non-essential to any metabolic process and, moreover, highly deleterious to life. In microbial mats - benthic stratified ecosystems - located in coastal areas, phototrophic microorganisms (algae and oxygenic phototrophic bacteria) are the primary producers and they are exposed to pollution by metals. In this paper we describe the search for bioindicators among phototrophic populations of Ebro delta microbial mats, using high-resolution microscopic techniques that we have optimized in previous studies. Confocal laser scanning microscopy coupled to a spectrofluorometric detector (CLSM-λscan) to determine in vivo sensitivity of different cyanobacteria to lead, and scanning electron microscopy (SEM) and transmission electron microscopy (TEM), both coupled to energy dispersive X-ray microanalysis (EDX), to determine the extra- and intracellular sequestration of this metal in cells, were the techniques used for this purpose. Oscillatoria sp. PCC 7515, Chroococcus sp. PCC 9106 and Spirulina sp. PCC 6313 tested in this paper could be considered bioindicators for lead pollution, because all of these microorganisms are indigenous, have high tolerance to high concentrations of lead and are able to accumulate this metal externally in extracellular polymeric substances (EPS) and intracellularly in polyphosphate (PP) inclusions. Experiments made with microcosms demonstrated that Phormidium-like and Lyngbya-like organisms selected themselves at the highest concentrations of lead assayed. In the present study it is shown that all cyanobacteria studied (both in culture and in microcosms) present PP inclusions in their cytoplasm and that these increase in number in lead polluted cultures and microcosms. We believe that the application of these microscopic techniques open up broad prospects for future studies of metal ecotoxicity. Copyright © 2011 Elsevier B.V. All rights reserved.

Pengendalian Hayati Penyakit Layu Fusarium Pisang (Fusarium oxysporum f.sp. cubense dengan Trichoderma sp.

Directory of Open Access Journals (Sweden)

Albertus Sudirman

2011-07-01

Full Text Available The aim of this research was to study the inhibiting ability of Trichoderma sp. to control fusarium wilt of banana in greenhouse condition. The experiments consisted of the antagonism test between Trichoderma sp. and Fusarium oxysporum f.sp. cubense (Foc in vitro using dual culture method and glass house experiment which was arranged in 3×3 Factorial Complete Randomized Design. First factor of the latter experiment was the dose of Trichoderma sp. culture (0, 25, and 50 g per polybag, second factor was time of Trichoderma culture application (2 weeks before Foc inoculation, at same time with Foc inoculation and 2 weeks after Foc inoculation. Trichoderma sp. was cultured in mixed rice brand and chaff medium. The disease intensity was observed with scoring system of wilting leaves (0–4. The results showed that Trichoderma sp. was antagonistic against Foc in vitro and inhibited 86% of Foc colony development. Mechanism of antagonism between Trichoderma sp. and Foc was hyperparasitism. Trichoderma hyphae coiled around Foc hyphae. Lysis of Foc hyphae was occurred at the attached site of Trichoderma hyphae on Foc hyphae. Added banana seedling with Trichoderma sp. Culture reduced disease intensity of Fusarium wilt. Suggested dose of Trichoderma culture application in glass house was 25 g/polybag, given at the same time with Foc inoculation. Penelitian ini bertujuan untuk mengetahui kemampuan Trichoderma sp. untuk pengendalian penyakit layu fusarium pisang di rumah kaca. Penelitian meliputi pengujian daya hambat Fusarium oxysporum f.sp. cubense (Foc in vitro dan kemampuan menekan intensitas penyakit di rumah kaca. Penelitian in vitro meliputi uji antagonisme dan mekanismenya yang dilakukan secara dual culture. Uji pengaruh Trichoderma sp. terhadap penyakit layu Fusarium dilakukan di rumah kaca dengan Rancangan Acak Lengkap Faktorial. Faktor pertama adalah dosis biakan Trichoderma sp., dengan tiga aras (0, 25, 50 g/per bibit dalam polibag. Faktor kedua

SP140L, an Evolutionarily Recent Member of the SP100 Family, Is an Autoantigen in Primary Biliary Cirrhosis

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Mario Saare

2015-01-01

Full Text Available The SP100 family members comprise a set of closely related genes on chromosome 2q37.1. The widely expressed SP100 and the leukocyte-specific proteins SP110 and SP140 have been associated with transcriptional regulation and various human diseases. Here, we have characterized the SP100 family member SP140L. The genome sequence analysis showed the formation of SP140L gene through rearrangements of the two neighboring genes, SP100 and SP140, during the evolution of higher primates. The SP140L expression is interferon-inducible with high transcript levels in B cells and other peripheral blood mononuclear cells. Subcellularly, SP140L colocalizes with SP100 and SP140 in nuclear structures that are devoid of SP110, PML, or p300 proteins. Similarly to SP100 and SP140 protein, we detected serum autoantibodies to SP140L in patients with primary biliary cirrhosis using luciferase immunoprecipitation system and immunoblotting assays. In conclusion, our results show that SP140L is phylogenetically recent member of SP100 proteins and acts as an autoantigen in primary biliary cirrhosis patients.

Environmental conditions affecting exopolysaccharide production by Pseudomonas aeruginosa, Micrococcus sp., and Ochrobactrum sp.

Science.gov (United States)

Kiliç, Nur Koçberber; Dönmez, Gönül

2008-06-15

Three different chromium-resistant microorganisms (Pseudomonas aeruginosa, Micrococcus sp., and Ochrobactrum sp.) were tested with regard to their EPS production at different pH levels, temperatures, Cr(VI) concentrations, and incubation periods. The optimum pH level was 7 for P. aeruginosa and Micrococcus sp., while it was 8 for Ochrobactrum sp. according to the highest EPS amount at 100 mg/L Cr(VI) concentration. The highest production of EPSs by the three bacteria was obtained under different environmental conditions. P. aeruginosa produced the highest EPS (863.3 mg/L) after incubation for 96 h on media with 50 mg/L Cr(VI) at 20 degrees C, Micrococcus sp. gave the highest yield (444.6 mg/L) after incubation for 72 h on media with 100 mg/L Cr(VI) at the same temperature, and Ochrobactrum sp. had the highest production (430.5 mg/L) on media with 150 mg/L Cr(VI) at 30 degrees C at the end of 48 h of incubation.

Superhard sp2–sp3 hybrid carbon allotropes with tunable electronic properties

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Meng Hu

2016-05-01

Full Text Available Four sp2–sp3 hybrid carbon allotropes are proposed on the basis of first principles calculations. These four carbon allotropes are energetically more favorable than graphite under suitable pressure conditions. They can be assembled from graphite through intralayer wrinkling and interlayer buckling, which is similar to the formation of diamond from graphite. For one of the sp2–sp3 hybrid carbon allotropes, mC24, the electron diffraction patterns match these of i-carbon, which is synthesized from shock-compressed graphite (H. Hirai and K. Kondo, Science, 1991, 253, 772. The allotropes exhibit tunable electronic characteristics from metallic to semiconductive with band gaps comparable to those of silicon allotropes. They are all superhard materials with Vickers hardness values comparable to that of cubic BN. The sp2–sp3 hybrid carbon allotroes are promising materials for photovoltaic electronic devices, and abrasive and grinding tools.

Selective C(sp2)-C(sp) bond cleavage: the nitrogenation of alkynes to amides.

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Qin, Chong; Feng, Peng; Ou, Yang; Shen, Tao; Wang, Teng; Jiao, Ning

2013-07-22

Breakthrough: A novel catalyzed direct highly selective C(sp2)-C(sp) bond functionalization of alkynes to amides has been developed. Nitrogenation is achieved by the highly selective C(sp2)-C(sp) bond cleavage of aryl-substituted alkynes. The oxidant-free and mild conditions and wide substrate scope make this method very practical. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cultivation and complete genome sequencing of Gloeobacter kilaueensis sp. nov., from a lava cave in Kīlauea Caldera, Hawai'i.

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Jimmy H W Saw

Full Text Available The ancestor of Gloeobacter violaceus PCC 7421(T is believed to have diverged from that of all known cyanobacteria before the evolution of thylakoid membranes and plant plastids. The long and largely independent evolutionary history of G. violaceus presents an organism retaining ancestral features of early oxygenic photoautotrophs, and in whom cyanobacteria evolution can be investigated. No other Gloeobacter species has been described since the genus was established in 1974 (Rippka et al., Arch Microbiol 100:435. Gloeobacter affiliated ribosomal gene sequences have been reported in environmental DNA libraries, but only the type strain's genome has been sequenced. However, we report here the cultivation of a new Gloeobacter species, G. kilaueensis JS1(T, from an epilithic biofilm in a lava cave in Kīlauea Caldera, Hawai'i. The strain's genome was sequenced from an enriched culture resembling a low-complexity metagenomic sample, using 9 kb paired-end 454 pyrosequences and 400 bp paired-end Illumina reads. The JS1(T and G. violaceus PCC 7421(T genomes have little gene synteny despite sharing 2842 orthologous genes; comparing the genomes shows they do not belong to the same species. Our results support establishing a new species to accommodate JS1(T, for which we propose the name Gloeobacter kilaueensis sp. nov. Strain JS1(T has been deposited in the American Type Culture Collection (BAA-2537, the Scottish Marine Institute's Culture Collection of Algae and Protozoa (CCAP 1431/1, and the Belgian Coordinated Collections of Microorganisms (ULC0316. The G. kilaueensis holotype has been deposited in the Algal Collection of the US National Herbarium (US# 217948. The JS1(T genome sequence has been deposited in GenBank under accession number CP003587. The G+C content of the genome is 60.54 mol%. The complete genome sequence of G. kilaueensis JS1(T may further understanding of cyanobacteria evolution, and the shift from anoxygenic to oxygenic photosynthesis.

The Relationship Between Iron and Nitrogen Fixation in Trichodesmium spp.

Science.gov (United States)

2009-06-01

Genes essential to iron transport in the cyanobacterium Synechocystis sp. strain PCC 6803. J Bacteriol 183: 2779-2784. Keren, N., Aurora , R., and...where surface salinity measurements indicate that we were sampling in the Amazon River plume. At E21, the surface salinity measured by the CTD was 32.5

In vitro cytotoxicity evaluation of nano-carbon particles with different sp{sup 2}/sp{sup 3} ratios

Energy Technology Data Exchange (ETDEWEB)

Li, S.S.; Wu, B.J.; Deng, Q.Y. [Key Laboratory for Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Guo, Y.B. [The Third People' s Hospital of Chengdu, Sichuan 610031 (China); Leng, Y.X., E-mail: yxleng@263.net [Key Laboratory for Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Huang, N. [Key Laboratory for Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China)

2017-06-01

Graphitization occurs during the long-term service of a diamond-like carbon (DLC) modified artificial joint. Then, DLC wear debris, which are carbon particles with different sp{sup 2}/sp{sup 3} ratios and sizes ranging from the nano- to micro-meter scale produced. In this paper, to promote the application of DLC coating for artificial joint modification, the cytotoxicity of DLC debris (nano-carbon particles, NCs) with different sp{sup 2}/sp{sup 3} ratios was studied. The microstructure and physical characteristics of NCs with different sp{sup 2}/sp{sup 3} ratios were investigated by Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Transmission Electron Microscope (TEM) and Dynamic Light Scattering (DLS). Meanwhile, osteoblasts and macrophages were applied to characterize the cytotoxicity of the NCs. In vitro cytotoxicity assay results indicated that cells incubated with NCs of different sp{sup 2}/sp{sup 3} ratios had greater osteogenic capacity, and these particles caused a weaker immune response in comparison with CoCrMo particles. Taken together, the results indicated that NCs with different sp{sup 2}/sp{sup 3} ratios presented a good cytocompatibility than CoCrMo particles. But no significant differences were observed among NCs with different sp{sup 2}/sp{sup 3} ratios. The better cytocompatibility of NCs is mainly attributable to their surface charge. - Highlights: • NCs with different sp{sup 2}/sp{sup 3} ratios have been successfully prepared by annealing treatment. • NCs with different sp{sup 2}/sp{sup 3} ratios show good osteogenic capacity and lower immune response. • The good cytocompatibility of NCs is mainly dependent on its surface charge.

Xylanolytic enzyme systems in Arthrobacter sp MTCC 5214 and Lactobacillus sp.

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Khandeparker, R.; Jalal, T.

The production of extracellular xylanolytic enzymes such as xylanase, alfa-L-arabinofuranosidase (alfa-l-AFase), and acetyl xylan esterase (Axe) by marine Arthrobacter sp and Lactobacillus sp was investigated using different carbon sources Induction...

A comparative genomics approach to understanding the biosynthesis of the sunscreen scytonemin in cyanobacteria

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Potrafka Ruth M

2009-07-01

Full Text Available Abstract Background The extracellular sunscreen scytonemin is the most common and widespread indole-alkaloid among cyanobacteria. Previous research using the cyanobacterium Nostoc punctiforme ATCC 29133 revealed a unique 18-gene cluster (NpR1276 to NpR1259 in the N. punctiforme genome involved in the biosynthesis of scytonemin. We provide further genomic characterization of these genes in N. punctiforme and extend it to homologous regions in other cyanobacteria. Results Six putative genes in the scytonemin gene cluster (NpR1276 to NpR1271 in the N. punctiforme genome, with no previously known protein function and annotated in this study as scyA to scyF, are likely involved in the assembly of scytonemin from central metabolites, based on genetic, biochemical, and sequence similarity evidence. Also in this cluster are redundant copies of genes encoding for aromatic amino acid biosynthetic enzymes. These can theoretically lead to tryptophan and the tyrosine precursor, p-hydroxyphenylpyruvate, (expected biosynthetic precursors of scytonemin from end products of the shikimic acid pathway. Redundant copies of the genes coding for the key regulatory and rate-limiting enzymes of the shikimic acid pathway are found there as well. We identified four other cyanobacterial strains containing orthologues of all of these genes, three of them by database searches (Lyngbya PCC 8106, Anabaena PCC 7120, and Nodularia CCY 9414 and one by targeted sequencing (Chlorogloeopsis sp. strain Cgs-089; CCMEE 5094. Genomic comparisons revealed that most scytonemin-related genes were highly conserved among strains and that two additional conserved clusters, NpF5232 to NpF5236 and a putative two-component regulatory system (NpF1278 and NpF1277, are likely involved in scytonemin biosynthesis and regulation, respectively, on the basis of conservation and location. Since many of the protein product sequences for the newly described genes, including ScyD, ScyE, and ScyF, have

Removal of Anabaena flos-aquae in water treatment process using Moringa oleifera and assessment of fatty acid profile of generated sludge.

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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.

Sp6 and Sp8 Transcription Factors Control AER Formation and Dorsal-Ventral Patterning in Limb Development

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Haro, Endika; Delgado, Irene; Junco, Marisa; Yamada, Yoshihiko; Mansouri, Ahmed; Oberg, Kerby C.; Ros, Marian A.

2014-01-01

The formation and maintenance of the apical ectodermal ridge (AER) is critical for the outgrowth and patterning of the vertebrate limb. The induction of the AER is a complex process that relies on integrated interactions among the Fgf, Wnt, and Bmp signaling pathways that operate within the ectoderm and between the ectoderm and the mesoderm of the early limb bud. The transcription factors Sp6 and Sp8 are expressed in the limb ectoderm and AER during limb development. Sp6 mutant mice display a mild syndactyly phenotype while Sp8 mutants exhibit severe limb truncations. Both mutants show defects in AER maturation and in dorsal-ventral patterning. To gain further insights into the role Sp6 and Sp8 play in limb development, we have produced mice lacking both Sp6 and Sp8 activity in the limb ectoderm. Remarkably, the elimination or significant reduction in Sp6;Sp8 gene dosage leads to tetra-amelia; initial budding occurs, but neither Fgf8 nor En1 are activated. Mutants bearing a single functional allele of Sp8 (Sp6−/−;Sp8+/−) exhibit a split-hand/foot malformation phenotype with double dorsal digit tips probably due to an irregular and immature AER that is not maintained in the center of the bud and on the abnormal expansion of Wnt7a expression to the ventral ectoderm. Our data are compatible with Sp6 and Sp8 working together and in a dose-dependent manner as indispensable mediators of Wnt/βcatenin and Bmp signaling in the limb ectoderm. We suggest that the function of these factors links proximal-distal and dorsal-ventral patterning. PMID:25166858

Activity of glycosidases from freshwater heterotrophic microorganisms on the degradation of extracellular polysaccharide produced by Anabaena spiroides (Cyanobacteria Atividade de glicosidases liberadas por microorganismos heterotróficos de água doce na degradação do polissacarídeo extracelular produzido por Anabaena spiroides (Cyanobacteria

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Vanessa Colombo

2004-06-01

Full Text Available The activity of specific glycosidases during the degradation of the extracellular polysaccharide (EPS produced by Anabaena spiroides was determined using MUF-substrates (MUF-monosaccharides. Polysaccharide degradation was found to occur in a two-phase process. The first consisted of high enzymatic activity that consumed 41% of the EPS at a relatively high rate, while the second consumed the remaining polysaccharide (59% at a slower rate. A transition phase from the higher to the slower degradation rates was marked by a replacement of bacterial populations from coccoid to bacillus cells. During the degradation process, the bacterial biomass increased with the decrease of EPS, as revealed by bacterial cell counts. The enzymatic activity detected through the substrates MUF-alpha-D- and MUF-beta-D-glucoside was higher than that detected by other substrates tested. The remaining glycosides were MUF-alpha-L-rhamnopyranoside, MUF-beta-D-galactoside, MUF-alpha-D-mannopyranoside, MUF-beta-D-fucoside, MUF-beta-D-mannopyranoside, MUF-alpha-L-arabinopyranoside, and MUF-beta-L-fucoside. The fluorescence emitted by each MUF-substrate was proportional to the concentration of the corresponding monosaccharide in A. spiroides EPS. This demonstrates the susceptibility of EPS produced by A. spiroides to enzymatic attack by bacterial populations.A atividade de glicosidases durante a degradação do polissacarídeo extracelular (EPS produzido por Anabaena spiroides foi detectada e quantificada utilizando-se MUF-substratos (MUF-monossacarídeos. O consumo total do polissacarídeo efetuou-se em duas fases, uma primeira de alta atividade enzimática que rapidamente consumiu 41% do polissacarídeo e uma segunda, mais lenta, que consumiu o polissacarídeo restante (59%. A mudança de fase coincidiu com a sucessão de uma população de bactérias cocóides por outra de bacilos. A biomassa bacteriana, quantificada por contagens de células, aumentou com a degradação do

Fresh Water Cyanobacteria Geitlerinema sp. CCC728 and Arthrospira sp. CCC729 as an Anticancer Drug Resource

OpenAIRE

Srivastava, Akanksha; Tiwari, Ratnakar; Srivastava, Vikas; Singh, Tej Bali; Asthana, Ravi Kumar

2015-01-01

An increasing number of cancer patients worldwide, especially in third world countries, have raised concern to explore natural drug resources, such as the less explored fresh water filamentous cyanobacteria. Six strains of cyanobacteria (Phormidium sp. CCC727, Geitlerinema sp. CCC728, Arthrospira sp. CCC729, Phormidium sp. CCC731, Phormidium sp. CCC730, and Leptolyngbya sp. CCC732) were isolated (paddy fields and ponds in the Banaras Hindu University, campus) and five strains screened for ant...

Pengendalian Hayati Penyakit Layu Fusarium Pisang (Fusarium Oxysporum F.sp. Cubense) dengan Trichoderma SP.

OpenAIRE

Sudirman, Albertus; Sumardiyono, Christanti; Widyastuti, Siti Muslimah

2011-01-01

The aim of this research was to study the inhibiting ability of Trichoderma sp. to control fusarium wilt of banana in greenhouse condition. The experiments consisted of the antagonism test between Trichoderma sp. and Fusarium oxysporum f.sp. cubense (Foc) in vitro using dual culture method and glass house experiment which was arranged in 3×3 Factorial Complete Randomized Design. First factor of the latter experiment was the dose of Trichoderma sp. culture (0, 25, and 50 g per polybag), second...

The Pkn22 Ser/Thr kinase in Nostoc PCC 7120: role of FurA and NtcA regulators and transcript profiling under nitrogen starvation and oxidative stress.

Science.gov (United States)

Yingping, Fan; Lemeille, Sylvain; González, Andrés; Risoul, Véronique; Denis, Yann; Richaud, Pierre; Lamrabet, Otmane; Fillat, Maria F; Zhang, Cheng-Cai; Latifi, Amel

2015-07-29

The filamentous cyanobacterium Nostoc sp. strain PCC 7120 can fix N2 when combined nitrogen is not available. Furthermore, it has to cope with reactive oxygen species generated as byproducts of photosynthesis and respiration. We have previously demonstrated the synthesis of Ser/Thr kinase Pkn22 as an important survival response of Nostoc to oxidative damage. In this study we wished to investigate the possible involvement of this kinase in signalling peroxide stress and nitrogen deprivation. Quantitative RT-PCR experiments revealed that the pkn22 gene is induced in response to peroxide stress and to combined nitrogen starvation. Electrophoretic motility assays indicated that the pkn22 promoter is recognized by the global transcriptional regulators FurA and NtcA. Transcriptomic analysis comparing a pkn22-insertion mutant and the wild type strain indicated that this kinase regulates genes involved in important cellular functions such as photosynthesis, carbon metabolism and iron acquisition. Since metabolic changes may lead to oxidative stress, we investigated whether this is the case with nitrogen starvation. Our results rather invalidate this hypothesis thereby suggesting that the function of Pkn22 under nitrogen starvation is independent of its role in response to peroxide stress. Our analyses have permitted a more complete functional description of Ser/Thr kinase in Nostoc. We have decrypted the transcriptional regulation of the pkn22 gene, and analysed the whole set of genes under the control of this kinase in response to the two environmental changes often encountered by cyanobacteria in their natural habitat: oxidative stress and nitrogen deprivation.

The Effect of Acupuncture to SP6 on Skin Temperature Changes of SP6 and SP10: An Observation of “Deqi”

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Jia-Min Yang

2014-01-01

Full Text Available Background. Deqi sensation is a complex but an important component for acupuncture effect. In this study, we tried to observe the relationship between Deqi and skin temperature changes and whether there was some relativity between Deqi and needle stimulations on cold congealing and dysmenorrhea rat model. Thirty-two female Sprague Dawley (SD rats were randomly divided into four groups (Saline Control Group, Model Group, Group A with strong stimulation, and Group B with small stimulation. Group A and Group B were performed with different stimulations. We found that, compared with saline control group, model group, and Group B, Group A showed that the skin temperature changes on right acupoint SP6 and SP10 increased significantly at 5 min–10 min interval. The skin temperature changes on left SP6 decreased at instant–5 min interval. The skin temperature changes on right SP10 decreased significantly at instant–5 min interval and 10 min–20 min interval. Thermogenic action along Spleen Meridian of Foot Greater Yin was manifested as simultaneous skin temperature increase on right SP6 and SP10 at 5 min–10 min interval after needling SP6, which was helpful to illustrate the relationship between the characteristic of Deqi and needle stimulations.

Is Monoglucosyldiacylglycerol a Precursor to Monogalactosyldiacylglycerol in All Cyanobacteria?

Science.gov (United States)

Sato, Naoki

2015-10-01

Monogalactosyldiacylglycerol (MGDG) is ubiquitous in the photosynthetic membranes of cyanobacteria and chloroplasts. It is synthesized by galactosylation of diacylglycerol (DAG) in the chloroplasts, whereas it is produced by epimerization of monoglucosyldiacylglycerol (GlcDG) in at least several cyanobacteria that have been analyzed such as Synechocystis sp. PCC 6803. A previous study, however, showed that the mgdE gene encoding the epimerase is absent in some cyanobacteria such as Gloeobacter violaceus, Thermosynechococcus elongatus and Acaryochloris marina. In addition, the N-terminal 'fatty acid hydroxylase' domain is lacking in the MgdE protein of Prochlorococcus marinus. These problems may cast doubt upon the general (or exclusive) role of MgdE in the epimerization of GlcDG to MGDG in cyanobacteria. In addition, GlcDG is usually present at a very low level, and the structural determination of endogenous GlcDG has not been accomplished with cyanobacterial samples. In this study, I determined the structure of GlcDG from Anabaena variabilis by (1)H- and (13)C-nuclear magnetic resonance (NMR) spectroscopy. I then showed that G. violaceus, T. elongatus, A. marina and P. marinus contain GlcDG. In all cases, GlcDG consisted of fewer unsaturated molecular species than MGDG, providing further evidence that GlcDG is a precursor to MGDG. The conversion of GlcDG to MGDG was also demonstrated by radiolabeling and chase experiments in G. violaceus and P. marinus. These results demonstrate that all the analyzed cyanobacteria contain GlcDG, which is converted to MGDG, and suggest that an alternative epimerase is required for MGDG synthesis in these cyanobacteria. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Interaction of Sp1 zinc finger with transport factor in the nuclear localization of transcription factor Sp1

International Nuclear Information System (INIS)

Ito, Tatsuo; Kitamura, Haruka; Uwatoko, Chisana; Azumano, Makiko; Itoh, Kohji; Kuwahara, Jun

2010-01-01

Research highlights: → Sp1 zinc fingers themselves interact with importin α. → Sp1 zinc finger domains play an essential role as a nuclear localization signal. → Sp1 can be transported into the nucleus in an importin-dependent manner. -- Abstract: Transcription factor Sp1 is localized in the nucleus and regulates the expression of many cellular genes, but the nuclear transport mechanism of Sp1 is not well understood. In this study, we revealed that GST-fused Sp1 protein bound to endogenous importin α in HeLa cells via the Sp1 zinc finger domains, which comprise the DNA binding domain of Sp1. It was found that the Sp1 zinc finger domains directly interacted with a wide range of importin α including the armadillo (arm) repeat domain and the C-terminal acidic domain. Furthermore, it turned out that all three zinc fingers of Sp1 are essential for binding to importin α. Taken together, these results suggest that the Sp1 zinc finger domains play an essential role as a NLS and Sp1 can be transported into the nucleus in an importin-dependent manner even though it possesses no classical NLSs.

Role of surfactant protein A (SP-A)/lipid interactions for SP-A functions in the lung.

Science.gov (United States)

Casals, C

2001-01-01

Surfactant protein A (SP-A), an oligomeric glycoprotein, is a member of a group of proteins named collectins that contain collagen-like and Ca(2+)-dependent carbohydrate recognition domains. SP-A interacts with a broad range of amphipathic lipids (glycerophospholipids, sphingophospholipids, glycosphingolipids, lipid A, and lipoglycans) that are present in surfactant or microbial membranes. This review summarizes SP-A/lipid interaction studies regarding the lipid system used (i.e., phospholipid vesicles, phospholipid monolayers, and lipids immobilized on silica or adsorbed on a solid support). The effect of calcium, ionic strength, and pH on the binding of SP-A to lipids and the subsequent lipid aggregation process is discussed. Current evidence suggests that hydrophobic-binding forces are involved in the peripherical association of SP-A to membranes. It is also proposed that fluid and liquid-ordered phase coexistence in surfactant membranes might favor partition of SP-A into those membranes. The binding of SP-A to surfactant membranes containing hydrophobic surfactant peptides makes possible the formation of a membrane reservoir in the alveolar fluid that is protected by SP-A against inactivation and improves the rate of surfactant film formation. In addition, the interaction of SP-A with membranes might enhance the affinity of SP-A for terminal carbohydrates of glycolipids or glycoproteins on the surface of invading microorganisms.

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

Science.gov (United States)

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

2014-01-01

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

Five novel Wickerhamomyces- and Metschnikowia-related yeast species, Wickerhamomyces chaumierensis sp. nov., Candida pseudoflosculorum sp. nov., Candida danieliae sp. nov., Candida robnettiae sp. nov. and Candida eppingiae sp. nov., isolated from plants

NARCIS (Netherlands)

Groenewald, Marizeth; Robert, Vincent; Smith, Maudy Th

On the basis of nucleotide divergences in the D1/D2 domain of the 26S rRNA gene and the internal transcribed spacers (ITS) domain of the rRNA gene, five novel yeast species, Wickerhamomyces chaumierensis sp. nov. (CBS 8565(T)  = JCM 17246(T)), Candida pseudoflosculorum sp. nov. (CBS 8584(T)  = JCM

Phylogenetically distant clade of Nostoc-like taxa with the description of Aliinostoc gen. nov. and Aliinostoc morphoplasticum sp. nov.

Science.gov (United States)

Bagchi, Suvendra Nath; Dubey, Neelam; Singh, Prashant

2017-09-01

Nostoc is a complex and tough genus to differentiate, and its morphological plasticity makes it taxonomically complicated. Its cryptic diversity and almost no distinguishable morphological characteristics make this genus incredibly heterogeneous to evaluate on taxonomic scales. The strain NOS, isolated from a eutrophic water body, is being described as a new genus Aliinostoc with the strain showing motile hormogonia with gas vesicles as an atypical feature, which is currently considered as the diacritical feature of the genus but should be subjected to critical evaluation in the near future. The phylogenetic placement of Aliinostoc along with some other related sequences of Nostoc clearly separated this clade from Nostoc sensu stricto with high bootstrap support and robust topology in all the methods tested, thus providing strong proof of the taxa being representative of a new genus which morphologically appears to be Nostoc-like. Subsequent phylogenetic assessment using the rbcL, psbA, rpoC1 and tufA genes was done with the aim of facilitating future multi-locus studies on the proposed genus for better taxonomic clarity and resolution. Folding of the 16S-23S internal transcribed spacer region and subsequent comparisons with members of the genera Nostoc, Anabaena, Aulosira, Cylindrospermum, Sphaerospermopsis, Raphidiopsis, Desmonostoc and Mojavia gave entirely new secondary structures for the D1-D1' and box-B helix. Clear and separate clustering from Nostoc sensu stricto supports the establishment of Aliinostoc gen. nov. with the type species being Aliinostoc morphoplasticum sp. nov. in accordance with the International Code of Nomenclature for algae, fungi and plants.