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Sample records for rhodoseudomonas viridis rhodobacter

  1. Correlation of paramagnetic states and molecular structure in bacterial photosynthetic reaction centers: The symmetry of the primary electron donor in Rhodopseudomonas viridis and Rhodobacter sphaeroides R-26

    International Nuclear Information System (INIS)

    Norris, J.R.; Budil, D.E.; Gast, P.; Chang, C.H.; El-Kabbani, O.; Schiffer, M.

    1989-01-01

    The orientation of the principal axes of the primary electron donor triplet state measured in single crystals of photosynthetic reaction centers is compared to the x-ray structures of the bacteria Rhodobacter (Rb.) sphaeroides R-26 and Rhodopseudomonas (Rps.) viridis. The primary donor of Rps. viridis is significantly different from that of Rb. sphaeroides. The measured directions of the axes indicate that triplet excitation is almost completely localized on the L-subunit half of the dimer in Rps. viridis but is more symmetrically distributed on the dimeric donor in Rb. sphaeroides R-26. The large reduction of the zero field splitting parameters relative to monomeric bacteriochlorophyll triplet in vitro suggests significant participation of asymmetrical charge transfer electronic configurations in the special pair triplet state of both organisms

  2. Physiological Investigation Of Rhodobacter Sphaeroides

    OpenAIRE

    Özmeral, Özge

    2013-01-01

    Rhodobacter sphaeroides metabolik olarak geniş bir organizasyona sahip olan α-3 mor non-sülfür bir organizmadır. Oksijensiz ortamda R. sphaeroides hücreleri fotosentez, solunum ve fermantasyon yaparak çoğalabilir. R. sphaeroides hücrelerinde bulunan fotosentez yapımından sorumlu olan fotosentetik yapıları oksijenin varlığında oksijen tarafından zarara uğratıldığından fotosentez sadece oksijensiz ortamda meydana gelebilir. R. sphaeroides hücreleri fotosentezi fotoheterotrofik ve fotoototr...

  3. Bioactive Pentacyclic Triterpene Ester Derivatives from Alnus viridis ssp. viridis Bark.

    Science.gov (United States)

    Novakovic, Miroslav; Nikodinovic-Runic, Jasmina; Veselinovic, Jovana; Ilic-Tomic, Tatjana; Vidakovic, Vera; Tesevic, Vele; Milosavljevic, Slobodan

    2017-05-26

    Seven derivatives of pentacyclic triterpene acids (1-7) were isolated from the bark of Alnus viridis ssp. viridis using a combination of column chromatography and semipreparative HPLC. Compounds 1-3, 6, and 7 were determined to be new after spectroscopic data interpretation and were assigned as 27-hydroxyalphitolic acid derivatives (1-3), a 27-hydroxybetulinic acid derivative (6), and a 3-epi-maslinic acid derivative (7), respectively. Pentacyclic triterpenoids with a C-27 hydroxymethyl group have been found in species of the genus Alnus for the first time. These compounds were subjected to cytotoxicity testing against a number of cancer cell lines. Also, selected pentacyclic triterpenoids were selected as potential inhibitors of topoisomerases I and IIα for an in silico investigation.

  4. Ammonium and methylammonium transport in Rhodobacter sphaeroides

    International Nuclear Information System (INIS)

    Cordts, M.L.; Gibson, J.

    1987-01-01

    Rhodobacter spheroides maintained intracellular ammonium pools of 1.1 to 2.6 mM during growth in several fixed nitrogen sources as well as during diazotrophic growth. Addition of 0.15 mM NH 4 + to washed, nitrogen-free cell suspensions was followed by linear uptake of NH 4 + from the medium and transient formation of intracellular pools of 0.9 to 1.5 mM NH 4 + . Transport of NH 4 + was shown to be independent of assimilation by glutamine synthetase because intracellular pools of over 1 mM represented NH 4 + concentration gradients of at least 100-fold across the cytoplasmic membrane. Ammonium pools of over 1 mM were also found in non-growing cell suspensions in nitrogen-free medium after glutamine synthetase was inhibited with methionine sulfoximine. In NH 4 + -free cell suspensions, methylammonium ( 14 CH 3 NH 3 + ) was taken up rapidly, and intracellular concentrations of 0.4 to 0.5 mM were maintained. The 14 CN 3 NH 3 + pool was not affected by methionine sulfoximine. Unlike NH 4 + uptake, 14 CH 3 NH 3 + uptake in nitrogen-free cell suspensions was repressed by growth in NH 4 + . These results suggest that R. sphaeroides may produce an NH 4 + -specific transport system in addition to the NH 4 + / 14 CH 3 NH 3 + transporter. This second transporter is able to produce normal-size NH 4 + pools but has very little affinity for 14 CH 3 NH 3 + and is not repressed by growth in high concentrations of NH 4 +

  5. Ammonium and methylammonium transport in Rhodobacter sphaeroides

    Energy Technology Data Exchange (ETDEWEB)

    Cordts, M.L.; Gibson, J.

    1987-04-01

    Rhodobacter spheroides maintained intracellular ammonium pools of 1.1 to 2.6 mM during growth in several fixed nitrogen sources as well as during diazotrophic growth. Addition of 0.15 mM NH/sub 4//sup +/ to washed, nitrogen-free cell suspensions was followed by linear uptake of NH/sub 4//sup +/ from the medium and transient formation of intracellular pools of 0.9 to 1.5 mM NH/sub 4//sup +/. Transport of NH/sub 4//sup +/ was shown to be independent of assimilation by glutamine synthetase because intracellular pools of over 1 mM represented NH/sub 4//sup +/ concentration gradients of at least 100-fold across the cytoplasmic membrane. Ammonium pools of over 1 mM were also found in non-growing cell suspensions in nitrogen-free medium after glutamine synthetase was inhibited with methionine sulfoximine. In NH/sub 4//sup +/-free cell suspensions, methylammonium (/sup 14/CH/sub 3/NH/sub 3//sup +/) was taken up rapidly, and intracellular concentrations of 0.4 to 0.5 mM were maintained. The /sup 14/CN/sub 3/NH/sub 3//sup +/ pool was not affected by methionine sulfoximine. Unlike NH/sub 4//sup +/ uptake, /sup 14/CH/sub 3/NH/sub 3//sup +/ uptake in nitrogen-free cell suspensions was repressed by growth in NH/sub 4//sup +/. These results suggest that R. sphaeroides may produce an NH/sub 4//sup +/-specific transport system in addition to the NH/sub 4//sup +///sup 14/CH/sub 3/NH/sub 3//sup +/ transporter. This second transporter is able to produce normal-size NH/sub 4//sup +/ pools but has very little affinity for /sup 14/CH/sub 3/NH/sub 3//sup +/ and is not repressed by growth in high concentrations of NH/sub 4//sup +/.

  6. Tolerance of High Inorganic Mercury of Perna viridis : Laboratory ...

    African Journals Online (AJOL)

    Tolerance of High Inorganic Mercury of Perna viridis : Laboratory Studies of Its Accumulation, Depuration and Distribution. ... coefficient, indicating that it could act as one of the excretion routes for Hg and it can be proposed as a sensitive biomonitoring material for Hg. The fecal materials released by the mussel had elevated ...

  7. Intoxication of sheep exposed to ozark milkweed (Asclepias viridis Walter).

    Science.gov (United States)

    Smith, R A; Scharko, P; Bolin, D; Hong, C B

    2000-12-01

    Some 20 sheep died 1 at a time on a farm in Fleming County, KY, in late July of 1999 after consumption of Asclepias viridis Walter. Major histological lesions were mild multifocal nonsuppurative myocarditis. Gross pathology revealed wet and heavy lungs. Many affected animals had a hunched appearance, and marked posterior paresis was also observed.

  8. Genetic characterization of Perna viridis L. in peninsular Malaysia

    Indian Academy of Sciences (India)

    A total of 19 polymorphic microsatellite loci were used to analyse levels of genetic variation for 10 populations of Perna viridis L. collected from all over peninsular Malaysia. The populations involved in this study included Pulau Aman in Penang, Tanjung Rhu in Kedah, Bagan Tiang in Perak, Pulau Ketam in Selangor, Muar, ...

  9. Population genetics of Setaria viridis, a new model system.

    Science.gov (United States)

    Huang, Pu; Feldman, Maximilian; Schroder, Stephan; Bahri, Bochra A; Diao, Xianmin; Zhi, Hui; Estep, Matt; Baxter, Ivan; Devos, Katrien M; Kellogg, Elizabeth A

    2014-10-01

    An extensive survey of the standing genetic variation in natural populations is among the priority steps in developing a species into a model system. In recent years, green foxtail (Setaria viridis), along with its domesticated form foxtail millet (S. italica), has rapidly become a promising new model system for C4 grasses and bioenergy crops, due to its rapid life cycle, large amount of seed production and small diploid genome, among other characters. However, remarkably little is known about the genetic diversity in natural populations of this species. In this study, we survey the genetic diversity of a worldwide sample of more than 200 S. viridis accessions, using the genotyping-by-sequencing technique. Two distinct genetic groups in S. viridis and a third group resembling S. italica were identified, with considerable admixture among the three groups. We find the genetic variation of North American S. viridis correlates with both geography and climate and is representative of the total genetic diversity in this species. This pattern may reflect several introduction/dispersal events of S. viridis into North America. We also modelled demographic history and show signal of recent population decline in one subgroup. Finally, we show linkage disequilibrium decay is rapid (<45 kb) in our total sample and slow in genetic subgroups. These results together provide an in-depth understanding of the pattern of genetic diversity of this new model species on a broad geographic scale. They also provide key guidelines for on-going and future work including germplasm preservation, local adaptation, crossing designs and genomewide association studies. © 2014 John Wiley & Sons Ltd.

  10. Bioremediation of lead contaminated soil with Rhodobacter sphaeroides.

    Science.gov (United States)

    Li, Xiaomin; Peng, Weihua; Jia, Yingying; Lu, Lin; Fan, Wenhong

    2016-08-01

    Bioremediation with microorganisms is a promising technique for heavy metal contaminated soil. Rhodobacter sphaeroides was previously isolated from oil field injection water and used for bioremediation of lead (Pb) contaminated soil in the present study. Based on the investigation of the optimum culturing conditions and the tolerance to Pb, we employed the microorganism for the remediation of Pb contaminated soil simulated at different contamination levels. It was found that the optimum temperature, pH, and inoculum size for R. sphaeroides is 30-35 °C, 7, and 2 × 10(8) mL(-1), respectively. Rhodobacter sphaeroides did not remove the Pb from soil but did change its speciation. During the bioremediation process, more available fractions were transformed to less accessible and inert fractions; in particular, the exchangeable phase was dramatically decreased while the residual phase was substantially increased. A wheat seedling growing experiment showed that Pb phytoavailability was reduced in amended soils. Results inferred that the main mechanism by which R. sphaeroides treats Pb contaminated soil is the precipitation formation of inert compounds, including lead sulfate and lead sulfide. Although the Pb bioremediation efficiency on wheat was not very high (14.78% root and 24.01% in leaf), R. sphaeroides remains a promising alternative for Pb remediation in contaminated soil. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Optimization of Phenotyping Assays for the Model Monocot Setaria viridis.

    Science.gov (United States)

    Acharya, Biswa R; Roy Choudhury, Swarup; Estelle, Aiden B; Vijayakumar, Anitha; Zhu, Chuanmei; Hovis, Laryssa; Pandey, Sona

    2017-01-01

    Setaria viridis (green foxtail) is an important model plant for the study of C4 photosynthesis in panicoid grasses, and is fast emerging as a system of choice for the study of plant development, domestication, abiotic stress responses and evolution. Basic research findings in Setaria are expected to advance research not only in this species and its close relative S. italica (foxtail millet), but also in other panicoid grasses, many of which are important food or bioenergy crops. Here we report on the standardization of multiple growth and development assays for S. viridis under controlled conditions, and in response to several phytohormones and abiotic stresses. We optimized these assays at three different stages of the plant's life: seed germination and post-germination growth using agar plate-based assays, early seedling growth and development using germination pouch-based assays, and adult plant growth and development under environmentally controlled growth chambers and greenhouses. These assays will be useful for the community to perform large scale phenotyping analyses, mutant screens, comparative physiological analysis, and functional characterization of novel genes of Setaria or other related agricultural crops. Precise description of various growth conditions, effective treatment conditions and description of the resultant phenotypes will help expand the use of S. viridis as an effective model system.

  12. Optimization of Phenotyping Assays for the Model Monocot Setaria viridis

    Directory of Open Access Journals (Sweden)

    Biswa R. Acharya

    2017-12-01

    Full Text Available Setaria viridis (green foxtail is an important model plant for the study of C4 photosynthesis in panicoid grasses, and is fast emerging as a system of choice for the study of plant development, domestication, abiotic stress responses and evolution. Basic research findings in Setaria are expected to advance research not only in this species and its close relative S. italica (foxtail millet, but also in other panicoid grasses, many of which are important food or bioenergy crops. Here we report on the standardization of multiple growth and development assays for S. viridis under controlled conditions, and in response to several phytohormones and abiotic stresses. We optimized these assays at three different stages of the plant’s life: seed germination and post-germination growth using agar plate-based assays, early seedling growth and development using germination pouch-based assays, and adult plant growth and development under environmentally controlled growth chambers and greenhouses. These assays will be useful for the community to perform large scale phenotyping analyses, mutant screens, comparative physiological analysis, and functional characterization of novel genes of Setaria or other related agricultural crops. Precise description of various growth conditions, effective treatment conditions and description of the resultant phenotypes will help expand the use of S. viridis as an effective model system.

  13. The greening of the coasts: review of the Perna viridis success story.

    NARCIS (Netherlands)

    Rajagopal, S.; Venugopalan, V.P.; Velde, G. van der; Jenner, H.A.

    2006-01-01

    The green mussel Perna viridis has been receiving a lot of attention from workers working in the research areas of intertidal ecology, aquaculture, pollution monitoring, biofouling, zoogeography and invasion biology. P. viridis is a remarkable species in terms of its ability to reach very high

  14. Comprehensive EST analysis of the symbiotic sea anemone, Anemonia viridis

    Directory of Open Access Journals (Sweden)

    Deleury Emeline

    2009-07-01

    Full Text Available Abstract Background Coral reef ecosystems are renowned for their diversity and beauty. Their immense ecological success is due to a symbiotic association between cnidarian hosts and unicellular dinoflagellate algae, known as zooxanthellae. These algae are photosynthetic and the cnidarian-zooxanthellae association is based on nutritional exchanges. Maintenance of such an intimate cellular partnership involves many crosstalks between the partners. To better characterize symbiotic relationships between a cnidarian host and its dinoflagellate symbionts, we conducted a large-scale EST study on a symbiotic sea anemone, Anemonia viridis, in which the two tissue layers (epiderm and gastroderm can be easily separated. Results A single cDNA library was constructed from symbiotic tissue of sea anemones A. viridis in various environmental conditions (both normal and stressed. We generated 39,939 high quality ESTs, which were assembled into 14,504 unique sequences (UniSeqs. Sequences were analysed and sorted according to their putative origin (animal, algal or bacterial. We identified many new repeated elements in the 3'UTR of most animal genes, suggesting that these elements potentially have a biological role, especially with respect to gene expression regulation. We identified genes of animal origin that have no homolog in the non-symbiotic starlet sea anemone Nematostella vectensis genome, but in other symbiotic cnidarians, and may therefore be involved in the symbiosis relationship in A. viridis. Comparison of protein domain occurrence in A. viridis with that in N. vectensis demonstrated an increase in abundance of some molecular functions, such as protein binding or antioxidant activity, suggesting that these functions are essential for the symbiotic state and may be specific adaptations. Conclusion This large dataset of sequences provides a valuable resource for future studies on symbiotic interactions in Cnidaria. The comparison with the closest

  15. Comprehensive EST analysis of the symbiotic sea anemone, Anemonia viridis.

    Science.gov (United States)

    Sabourault, Cécile; Ganot, Philippe; Deleury, Emeline; Allemand, Denis; Furla, Paola

    2009-07-23

    Coral reef ecosystems are renowned for their diversity and beauty. Their immense ecological success is due to a symbiotic association between cnidarian hosts and unicellular dinoflagellate algae, known as zooxanthellae. These algae are photosynthetic and the cnidarian-zooxanthellae association is based on nutritional exchanges. Maintenance of such an intimate cellular partnership involves many crosstalks between the partners. To better characterize symbiotic relationships between a cnidarian host and its dinoflagellate symbionts, we conducted a large-scale EST study on a symbiotic sea anemone, Anemonia viridis, in which the two tissue layers (epiderm and gastroderm) can be easily separated. A single cDNA library was constructed from symbiotic tissue of sea anemones A. viridis in various environmental conditions (both normal and stressed). We generated 39,939 high quality ESTs, which were assembled into 14,504 unique sequences (UniSeqs). Sequences were analysed and sorted according to their putative origin (animal, algal or bacterial). We identified many new repeated elements in the 3'UTR of most animal genes, suggesting that these elements potentially have a biological role, especially with respect to gene expression regulation. We identified genes of animal origin that have no homolog in the non-symbiotic starlet sea anemone Nematostella vectensis genome, but in other symbiotic cnidarians, and may therefore be involved in the symbiosis relationship in A. viridis. Comparison of protein domain occurrence in A. viridis with that in N. vectensis demonstrated an increase in abundance of some molecular functions, such as protein binding or antioxidant activity, suggesting that these functions are essential for the symbiotic state and may be specific adaptations. This large dataset of sequences provides a valuable resource for future studies on symbiotic interactions in Cnidaria. The comparison with the closest available genome, the sea anemone N. vectensis, as well as

  16. Anampses viridis Valenciennes 1840 (Pisces: Labridae)--a case of taxonomic con- fusion and mistaken extinction.

    Science.gov (United States)

    Russell, Barry C; Craig, Matthew T

    2013-01-01

    Anampses viridis Valenciennes 1840 is known from only three specimens collected from Mauritius, and despite intensive sampling, the species has not been seen or reported since it was originally described. This apparent failure to 'rediscover' A. viridis at Mauritius has led to speculation that it is extinct, and the species has been widely cited as an example of a marine fish extinction. Far from being extinct, Anampses viridis has been taxonomically confused and actually is the adult male (terminal phase) colour form and a junior synonym of A. caeruleopunctatus Rüppell 1829, a species that is common and widespread throughout the Indo-West Pacific region.

  17. ADP-ribosylation of dinitrogenase reductase in Rhodobacter capsulatus

    International Nuclear Information System (INIS)

    Jouanneau, Y.; Roby, C.; Meyer, C.M.; Vignais, P.M.

    1989-01-01

    In the photosynthetic bacterium Rhodobacter capsulatus, nitrogenase is regulated by a reversible covalent modification of Fe protein or dinitrogenase reductase (Rc2). The linkage of the modifying group to inactive Rc2 was found to be sensitive to alkali and to neutral hydroxylamine. Complete release of the modifying group was achieved by incubation of inactive Rc2 in 0.4 or 1 M hydroxylamine. After hydroxylamine treatment of the Rc2 preparation, the modifying group could be isolated and purified by affinity chromatography and ion-exchange HPLC. The modifying group comigrated with ADP-ribose on both ion-exchange HPLC and thin-layer chromatography. Analyses by 31 P NMR spectroscopy and mass spectrometry provided further evidence that the modifying group was ADP-ribose. The NMR spectrum of inactive Rc2 exhibited signals characteristic of ADP-ribose; integration of these signals allowed calculation of a molar ration ADP-ribose/Rc2 of 0.63. A hexapeptide carrying the ADP-ribose moiety was purified from a subtilisin digest of inactive Rc2. The structure of this peptide, determined by amino acid analysis and sequencing, is Gly-Arg(ADP-ribose)-Gly-Val-Ile-Thr. This structure allows identification of the binding site for ADP-ribose as Arg 101 of the polypeptide chain of Rc2. It is concluded that nitrogenase activity in R. capsulatus is regulated by reversible ADP-ribosylation of a specific arginyl residue of dinitrogenase reductase

  18. SALT EFFECTS ON SWARMERS OF DUNALIELLA VIRIDIS TEOD

    Science.gov (United States)

    Baas-Becking, L. G. M.

    1931-01-01

    1. Dunaliella viridis Teodoresco thrives equally well in solutions of NaCl 1 to 4 mol and pH 6 to 9. 2. The organism is sensitive to calcium and magnesium, especially in acid medium. 3. Calcium and magnesium are antagonistic. In a molar solution of NaCl the antagonistic relation Mg:Ca is 4 to 5. In a 4 molar solution of NaCl the proportion becomes many times as great (20:1). 4. Although the strains used in this investigation did not occur in sea water concentrates, the increase in the antagonistic ratio Mg:Ca in which they can live closely paralleled the changes in this ratio which take place when sea water evaporates. 5. The other organisms which occurred in the cultures each show a specific relation to Ca and Mg. 6. The size of the cells of Dunaliella does not decrease with increasing NaCl content. PMID:19872621

  19. Preliminary study on the bioaccumulation of saxitoxins in Perna viridis through the dissolved pathway

    International Nuclear Information System (INIS)

    Almeida, Carmelo Adrian B.

    2011-03-01

    Paralytic shellfish poisoning (PSP) is a common fear among shellfish consumers. Saxitoxins are the group of compounds that are responsible for PSP. These compounds are produced by Pyrodinium bahamense var compresssum (PbC) which accumulate in perna viridis as they feed on PbC. This study aims to determine the presence of an alternative pathway, called the dissolved pathway, through which saxitoxins accumulate in Perna viridis independent of PbC. Perna viridis were exposed to a certain concentration of saxitoxins for a period of 24 hours and saxitoxin levels were determined at certain times throughout the period. The High Performance Liquid Chromatography (HPLC) - Oshima method was used in the measurement of toxins levels. Results show that mussels accumulate saxitoxins even in the absence of PbC, which supported the hypothesis that an alternative dissolved pathway contributes to the accumulation of saxitoxins in Perna viridis. (author)

  20. DNA damage in male gonad cells of Green mussel (Perna viridis) upon exposure to tobacco products

    Digital Repository Service at National Institute of Oceanography (India)

    Nagarajappa; Ganguly, A.; Goswami, U.

    DNA damage (determined by the Comet Assay) and the occurrence of deformed nuclei were measured as endpoints of genotoxicity in male gonad cells of the marine mussel (Perna viridis). Upon exposure of the organism to varying concentrations...

  1. A serine protease inhibitor from hemolymph of green mussel, Perna viridis

    Digital Repository Service at National Institute of Oceanography (India)

    Khan, M.S.; Goswami, U.; Rojatkar, S.R.; Khan, M.I.

    Bioactivity guided fractions of cell-free hemolymph of bacterially challenged marine mussel, Perna viridis led to the isolation of a novel quaternary alkaloid 1, which was identified by its spectral data. The isolated molecule 1 has been found...

  2. Growth of the green mussel, Perna viridis L., in a sea water circulating system

    Digital Repository Service at National Institute of Oceanography (India)

    Chatterji, A.; Ansari, Z.A.; Ingole, B.S.; Parulekar, A.H.

    Growth of the green mussel, P. viridis L., was studied in a sea water circulating system for 12 months. The maximum growth rate was recorded during March - May, coinciding with the maximum abundance of phytoplankton. The other hydrological...

  3. Methods for performing crosses in Setaria viridis, a new model system for the grasses.

    Science.gov (United States)

    Jiang, Hui; Barbier, Hugues; Brutnell, Thomas

    2013-10-01

    Setaria viridis is an emerging model system for C4 grasses. It is closely related to the bioenergy feed stock switchgrass and the grain crop foxtail millet. Recently, the 510 Mb genome of foxtail millet, S. italica, has been sequenced (1,2) and a 25x coverage genome sequence of the weedy relative S. viridis is in progress. S. viridis has a number of characteristics that make it a potentially excellent model genetic system including a rapid generation time, small stature, simple growth requirements, prolific seed production (3) and developed systems for both transient and stable transformation (4). However, the genetics of S. viridis is largely unexplored, in part, due to the lack of detailed methods for performing crosses. To date, no standard protocol has been adopted that will permit rapid production of seeds from controlled crosses. The protocol presented here is optimized for performing genetic crosses in S. viridis, accession A10.1. We have employed a simple heat treatment with warm water for emasculation after pruning the panicle to retain 20-30 florets and labeling of flowers to eliminate seeds resulting from newly developed flowers after emasculation. After testing a series of heat treatments at permissive temperatures and varying the duration of dipping, we have established an optimum temperature and time range of 48 °C for 3-6 min. By using this method, a minimum of 15 crosses can be performed by a single worker per day and an average of 3-5 outcross progeny per panicle can be recovered. Therefore, an average of 45-75 outcross progeny can be produced by one person in a single day. Broad implementation of this technique will facilitate the development of recombinant inbred line populations of S. viridis X S. viridis or S. viridis X S. italica, mapping mutations through bulk segregant analysis and creating higher order mutants for genetic analysis.

  4. Mapping of HABs Contaminated In Green Shells (Perna viridis) in Semarang Bay

    Science.gov (United States)

    A'in, Churun; Suryanti, Suryanti; Haeruddin, Haeruddin

    2018-02-01

    The existence of Harmful Algae Blooms (HABs) can adversely affect the water like a mass death of fish and oxygen depletion. Some types of HABs can be contaminated with seafood and contain biotoxins that are detrimental to the health of humans who consume them. Green mussels (Perna viridis) has the properties of filter feeders so vulnerable to contamination HABs. This research was conducted to produce spatially thematic maps contaminated HABs in P. viridis so providing information about risk prediction P. viridis when consumed by humans. Sampling was done purposively in three (3) stations that represent the Bay Semarang namely western boundary waters (Kendal), middle (Semarang) and the eastern boundary (Demak). Sampling done two (2) times, namely East season (June -July) and the second transitional season (September) 2016. Analysis of HABs done either in water or body tissues of P. viridis through the analysis of food habit. The results shows that P. viridis genus positive contaminated HABs phytoplankton Tricodesmium and Ceratium. Spatial distribution and abundance of Tricodesmium genus Fitoplankton is wider and taller than the HABs Phytoplankton genus Ceratium. Group HABs are found in the tissues of P. viridis no potential as biotoxin that does not cause adverse health risks.

  5. The Use of Maleic Hydrazide for Effective Hybridization of Setaria viridis.

    Directory of Open Access Journals (Sweden)

    Govinda Rizal

    Full Text Available An efficient method for crossing green foxtail (Setaria viridis is currently lacking. S. viridis is considered to be the new model plant for the study of C4 system in monocots and so an effective crossing protocol is urgently needed. S. viridis is a small grass with C4-NADP (ME type of photosynthesis and has the advantage of having small genome of about 515 Mb, small plant stature, short life cycle, multiple tillers, and profuse seed set, and hence is an ideal model species for research. The objectives of this project were to develop efficient methods of emasculation and pollination, and to speed up generation advancement. We assessed the response of S. viridis flowers to hot water treatment (48°C and to different concentrations of gibberellic acid, abscisic acid, maleic hydrazide (MH, and kinetin. We found that 500 μM of MH was effective in the emasculation of S. viridis, whilst still retaining the receptivity of the stigma to pollination. We also report effective ways to accelerate the breeding cycle of S. viridis for research through the germination of mature as well as immature seeds in optimized culture media. We believe these findings will be of great interest to researchers using Setaria.

  6. Hydrogen production by co-cultures of Lactobacillus and a photosynthetic bacterium, Rhodobacter sphaeroides RV

    Energy Technology Data Exchange (ETDEWEB)

    Asada, Yasuo; Ishimi, Katsuhiro [Department of General Education, College of Science and Technology, Nihon University, Narashinodai, Chiba 274-8501 (Japan); Tokumoto, Masaru; Aihara, Yasuyuki; Oku, Masayo; Kohno, Hideki [Department of Applied Molecular Chemistry, College of Industrial Technology, Nihon University, Izumi-cho, Chiba 275-8575 (Japan); Wakayama, Tatsuki; Miyake, Jun [Research Institute for Cell Engineering, National Institute of Advanced Industrial Science and Technology, Nakoji, Amagasaki, Hyogo 661-0974 (Japan); Tomiyama, Masamitsu [Genetic Diversity Department, National Institute of Agrobiological Science, Tsukuba, Ibaraki 305-8602 (Japan)

    2006-09-15

    Hydrogen production with glucose by using co-immobilized cultures of a lactic acid bacterium, Lactobacillus delbrueckii NBRC13953, and a photosynthetic bacterium, Rhodobacter sphaeroides RV, in agar gels was studied. Glucose was converted to hydrogen gas in a yield of 7.1mol of hydrogen per mole of glucose at a maximum under illuminated conditions. (author)

  7. Electrochemical determination of hydrogen peroxide using Rhodobacter capsulatus cytochrome c peroxidase at a gold electrode

    NARCIS (Netherlands)

    De Wael, K.; Buschop, H.; Heering, H.A.; De Smet, L.; Van Beeumen, J.; Devreese, B.; Adriaens, A.

    2007-01-01

    We describe the redox behaviour of horse heart cytochrome c (HHC) and Rhodobacter capsulatus cytochrome c peroxidase (RcCCP) at a gold electrode modified with 4,4?-bipyridyl. RcCCP shows no additional oxidation or reduction peaks compared to the electrochemistry of only HHC, which indicates that it

  8. ISOLATION AND CHARACTERIZATION OF THE HIGH-AFFINITY K+-TRANSLOCATING ATPASE FROM RHODOBACTER-SPHAEROIDES

    NARCIS (Netherlands)

    ABEE, T; SIEBERS, A; ALTENDORF, K; KONINGS, WN

    1992-01-01

    Cells of the purple nonsulfur bacterium Rhodobacter sphaeroides express a high-affinity K+ uptake system when grown in media with low K+ concentrations. A vanadate-sensitive, K+-stimulated and Mg2+-stimulated ATPase was purified from membranes of these cells by solubilization with

  9. Color-sensitive motility and methanol release responses in Rhodobacter sphaeroides

    NARCIS (Netherlands)

    Kort, R; Crielaard, W.; Spudich, J L; Hellingwerf, K J

    Blue-light-induced repellent and demethylation responses, characteristic of behavioral adaptation, were observed in Rhodobacter sphaeroides. They were analyzed by computer-assisted motion analysis and through the release of volatile tritiated compounds from [methyl-(3)H]methionine-labeled cells,

  10. Reference gene identification for reliable normalisation of quantitative RT-PCR data in Setaria viridis.

    Science.gov (United States)

    Nguyen, Duc Quan; Eamens, Andrew L; Grof, Christopher P L

    2018-01-01

    Quantitative real-time polymerase chain reaction (RT-qPCR) is the key platform for the quantitative analysis of gene expression in a wide range of experimental systems and conditions. However, the accuracy and reproducibility of gene expression quantification via RT-qPCR is entirely dependent on the identification of reliable reference genes for data normalisation. Green foxtail ( Setaria viridis ) has recently been proposed as a potential experimental model for the study of C 4 photosynthesis and is closely related to many economically important crop species of the Panicoideae subfamily of grasses, including Zea mays (maize), Sorghum bicolor (sorghum) and Sacchurum officinarum (sugarcane). Setaria viridis (Accession 10) possesses a number of key traits as an experimental model, namely; (i) a small sized, sequenced and well annotated genome; (ii) short stature and generation time; (iii) prolific seed production, and; (iv) is amendable to Agrobacterium tumefaciens -mediated transformation. There is currently however, a lack of reference gene expression information for Setaria viridis ( S. viridis ). We therefore aimed to identify a cohort of suitable S. viridis reference genes for accurate and reliable normalisation of S. viridis RT-qPCR expression data. Eleven putative candidate reference genes were identified and examined across thirteen different S. viridis tissues. Of these, the geNorm and NormFinder analysis software identified SERINE / THERONINE - PROTEIN PHOSPHATASE 2A ( PP2A ), 5 '- ADENYLYLSULFATE REDUCTASE 6 ( ASPR6 ) and DUAL SPECIFICITY PHOSPHATASE ( DUSP ) as the most suitable combination of reference genes for the accurate and reliable normalisation of S. viridis RT-qPCR expression data. To demonstrate the suitability of the three selected reference genes, PP2A , ASPR6 and DUSP , were used to normalise the expression of CINNAMYL ALCOHOL DEHYDROGENASE ( CAD ) genes across the same tissues. This approach readily demonstrated the suitably of the three

  11. Molecular characterization, ecology, and epidemiology of a novel Tymovirus in Asclepias viridis from Oklahoma.

    Science.gov (United States)

    Min, Byoung-Eun; Feldman, Tracy S; Ali, Akhtar; Wiley, Graham; Muthukumar, Vijay; Roe, Bruce A; Roossinck, Marilyn; Melcher, Ulrich; Palmer, Michael W; Nelson, Richard S

    2012-02-01

    Native virus-plant interactions require more understanding and their study will provide a basis from which to identify potential sources of emerging destructive viruses in crops. A novel tymovirus sequence was detected in Asclepias viridis (green milkweed), a perennial growing in a natural setting in the Tallgrass Prairie Preserve (TGPP) of Oklahoma. It was abundant within and frequent among A. viridis plants and, to varying extents, within other dicotyledonous and one grass (Panicum virgatum) species obtained from the TGPP. Extracts from A. viridis containing the sequence were infectious to a limited number of species. The virus genome was cloned and determined to be closely related to Kennedya yellow mosaic virus. The persistence of the virus within the Oklahoma A. viridis population was monitored for five successive years. Virus was present in a high percentage of plants within representative areas of the TGPP in all years and was spreading to additional plants. Virus was present in regions adjacent to the TGPP but not in plants sampled from central and south-central Oklahoma. Virus was present in the underground caudex of the plant during the winter, suggesting overwintering in this tissue. The RNA sequence encoding the virus coat protein varied considerably between individual plants (≈3%), likely due to drift rather than selection. An infectious clone was constructed and the virus was named Asclepias asymptomatic virus (AsAV) due to the absence of obvious symptoms on A. viridis.

  12. High mortality and poor growth of green mussels, Perna viridis, in high chlorophyll- a environment

    Science.gov (United States)

    Soon, Tan Kar; Denil, Delta Jenetty; Ransangan, Julian

    2016-03-01

    The current study was carried out from May 2014 to April 2015 to estimate the stock status of P. viridis in Marudu Bay. The gonad development was monitored by histological examination, while the population parameters including asymptotic length ( L ∞), growth coefficient ( K), mortality rate ( Z, F and M), exploitation level ( E) and recruitment of P. viridis were estimated using the lengthfrequency data. Results of the current study demonstrated that P. viridis in Marudu Bay spawned throughout the year with two major peaks, one in April to May and another one in October to December. The recruitment pattern was continuous with the peak in May to June 2014, which corresponded to the first spawning peak in April. However, no significant recruitment was observed from the second spawning peak due to the difference in spawning timing between male and female populations. The estimated asymptotic length ( L ∞), growth coefficient ( K), total mortality ( Z), natural mortality ( M), fishing mortality ( F) and growth performance ( φ) of P. viridis in Marudu Bay were estimate to be 117 mm, 0.97 yr-1, 4.39 yr-1, 1.23 yr-1, 3.16 yr-1 and 4.123, respectively. The exponent b of the lengthweight relationship was 2.4 and exploitation level ( E) was 0.72. The high mortality, low condition indices and negative allometric of P. viridis in Marudu Bay is caused by a lack of suitable food in the surrounding water.

  13. Abscission zone development in Setaria viridis and its domesticated relative, Setaria italica.

    Science.gov (United States)

    Hodge, John G; Kellogg, Elizabeth A

    2016-06-01

    Development of an abscission zone (AZ) is needed for dispersal of seeds, and AZ loss was a critical early step in plant domestication. The AZ forms in different tissues in different species of plants, but whether the AZ is developmentally similar wherever it occurs is unknown. AZ development in Setaria viridis was studied as a representative of the previously uncharacterized subfamily Panicoideae. One accession of the wild species S. viridis and two of its domesticate, S. italica, were studied. Strength of the AZ was measured with a force gauge. Anatomy of the AZ was studied throughout development using bright field and confocal microscopy. The force required to remove a spikelet of S. viridis from the parent plant dropped steadily during development, whereas that required to remove spikelets of S. italica increased initially before stabilizing at a high level. Despite the clear difference in tensile strength of the AZ, anatomical differences between S. viridis and S. italica were subtle, and the position of the AZ was not easy to determine in cross sections of pedicel apices. Staining with DAPI showed that nuclei were present up to and presumably through abscission in S. viridis, and acridine orange staining showed much less lignification than in other cereals. The AZ in Setaria is developmentally and anatomically different from that characterized in rice, barley, and many eudicots. In particular, no set of small, densely cytoplasmic cells is obvious. This difference in anatomy could point to differential genetic control of the structure. © 2016 Botanical Society of America.

  14. Assessment of pollution in road runoff using a Bufo viridis biological assay

    International Nuclear Information System (INIS)

    Dorchin, A.; Shanas, U.

    2010-01-01

    Road runoff is a major source of environmental pollution, significantly threatening nearby aquatic habitats. Chemical analyses indicate high pollutant concentrations in the road's 'first flush', but bioassays are more advantageous for addressing the cumulative effects of the numerous pollutants within the runoff. We used Bufo viridis embryos and larvae to assess the toxicity of road runoff from two major highways in Israel. We show, for the first time, that exposure to midseason runoff not only has an adverse effect on growth and development rates of B. viridis larvae but can also lead to increased rates of morphological deformations. Seasonal first flushes, despite having higher metal concentrations, did not adversely affect the toad larvae, apparently due to a counter effect of organic matter that potentially served as a supplementary energy resource. Road runoff can be a major cause for a qualitative decrease in the quality of aquatic habitats threatening amphibians in Israel. - Highway runoff has detrimental effects on the development of B. viridis larvae.

  15. Complete genome sequence of Saccharomonospora viridis type strain (P101T)

    Energy Technology Data Exchange (ETDEWEB)

    Pati, Amrita; Sikorski, Johannes; Nolan, Matt; Lapidus, Alla; Copeland, Alex; Glavina Del Rio, Tijana; Lucas, Susan; Chen, Feng; Tice, Hope; Pitluck, Sam; Cheng, Jan-Fang; Chertkov, Olga; Brettin, Thomas; Han, Cliff; Detter, John C.; Kuske, Cheryl; Bruce, David; Goodwin, Lynne; Chain, Patrick; D' haeseleer, Patrik; Chen, Amy; Palaniappan, Krishna; Ivanova, Natalia; Mavromatis, Konstantinos; Mikhailova, Natalia; Rohde, Manfred; Tindall, Brian J.; Goker, Markus; Bristow, Jim; Eisen, Jonathan A.; Markowitz, Victor; Hugenholtz, Philip; Kyrpides1, Nikos C.; Klenk, Hans-Peter

    2009-05-20

    Saccharomonospora viridis (Schuurmans et al. 1956) Nonomurea and Ohara 1971 is the type species of the genus Saccharomonospora which belongs to the family Pseudonocardiaceae. S. viridis is of interest because it is a Gram-negative organism classified amongst the usually Gram-positive actinomycetes. Members of the species are frequently found in hot compost and hay, and its spores can cause farmer?s lung disease, bagassosis, and humidifier fever. Strains of the species S. viridis have been found to metabolize the xenobiotic pentachlorophenol (PCP). The strain described in this study has been isolated from peat-bog in Ireland. Here we describe the features of this organism, together with the complete genome sequence, and annotation. This is the first complete genome sequence of the family Pseudonocardiaceae, and the 4,308,349 bp long single replicon genome with its 3906 protein-coding and 64 RNA genes is part of the Genomic Encyclopedia of Bacteria and Archaea project.

  16. A simple and highly efficient Agrobacterium-mediated transformation protocol for Setaria viridis

    Directory of Open Access Journals (Sweden)

    Polyana Kelly Martins

    2015-06-01

    Full Text Available The production and use of sugarcane in Brazil is very important for bioenergy production and is recognized as one of the most efficient in the world. In our laboratory, Setaria viridis is being tested as a model plant for sugarcane. S. viridis has biological attributes (rapid life cycle, small genome, diploid, short stature and simple growth requirements that make it suitable for use as a model system. We report a highly efficient protocol for Agrobacterium-mediated genetic transformation of S. viridis. The optimization of several steps in tissue culture allowed the rapid regeneration of plants and increased the rate of transformation up to 29%. This protocol could become a powerful tool for functional genomics in sugarcane.

  17. Abundance and size distribution of the sacoglossan Elysia viridis on co-occurring algal hosts on the Swedish west coast.

    Directory of Open Access Journals (Sweden)

    Finn A Baumgartner

    Full Text Available Sacoglossans are specialized marine herbivores that tend to have a close evolutionary relationship with their macroalgal hosts, but the widely distributed species Elysia viridis can associate with several algal species. However, most previous investigations on the field abundance and size distribution of E. viridis have focussed on Codium spp. in the British Isles, and algae from this genus are considered superior hosts for E. viridis. In the present study, we investigated the abundance and size distribution of E. viridis on 6 potential host algae with differing morphologies (the septate species Cladophora sericea, Cladophora rupestris, Chaetomorpha melagonium, and Ceramium virgatum, as well as the siphonaceous species Codium fragile and Bryopsis sp. at 2 sites on the Swedish west coast over the course of a year. In spring, slugs were almost absent from all algal hosts. In summer and autumn, E. viridis consistently occurred on several of the algal species at both sites. The highest number of small E. viridis were found on C. sericea, intermediate numbers of significantly larger E. viridis were found on C. rupestris, while fewer, intermediate sized animals were found on C. fragile. Throughout the study period, only a few E. viridis individuals were found on C. melagonium, Bryopsis sp., and C. virgatum. Our results indicate that E. viridis is an annual species in Sweden, capable of exploiting co-occurring congeneric and intergeneric algal hosts with differing morphologies. These results corroborate previous findings that E. viridis can exploit several different algal species, but does not indicate that C. fragile is a superior host.

  18. Moessbauer spectroscopy on the reaction center of Rhodopseudomonas viridis

    International Nuclear Information System (INIS)

    Frolov, E.; Goldanskii, V.I.; Birk, A.; Parak, F.; Fritzsch, G.; Sinning, I.; Michel, H.

    1992-01-01

    Proteins called 'reaction centers' (RC) can be isolated from many photosynthetic bacteria. They have one non-heme iron in a quinone acceptor region. The RC of Rhodopseudomonas viridis contains an additional tightly bound tetra-heme cytochrome c subunit. The electronic configuration of both cytochrome and the non-heme iron has been studied in the crystallized protein by Moessbauer spectroscopy at different redox potentials, pH-values, and with an addition of o-phenanthroline. At high potentials (E h =+500 mV) all heme irons are in the low spin Fe 3+ -state, and at low potential (E h = 1 50 mV) they are low spin Fe 2+ with the same Moessbauer parameters for all hemes independent of pH. Redox titrations change the relative area of the reduced and oxidized states in agreement with other methods. The non-heme iron shows a high spin Fe 2+ configuration independent of E h and pH with parameters comparable to those of Rhodopseudomonas sphaeroides. Surprisingly, there is strong evidence for another non-heme iron species in part of the molecules with a Fe 2+ low spin configuration. Incubation with o-phenanthroline decreases the relative Fe 2+ hs-area and increases the contribution of Fe 2+ ls-area. Above 210 K the mean square displacement, 2 >, of the RC-crystals increases more than linearly with temperature. This may be correlated with the increase of the electron transfer rate and indicates that intramolecular mobility influences the functional activity of a protein. (orig.)

  19. Photoresponses of the purple nonsulfur bacteria Rhodospirillum centenum and Rhodobacter sphaeroides.

    OpenAIRE

    Sackett, M J; Armitage, J P; Sherwood, E E; Pitta, T P

    1997-01-01

    We have measured the photoresponse of two purple nonsulfur bacteria, Rhodobacter sphaeroides and Rhodospirillum centenum, under defined conditions in a light beam propagating at 90 degrees to the optical axis of the microscope. This beam presented cells with a steep gradient of intensity perpendicular to the direction of propagation and a shallow gradient in the direction of light propagation. R. centenum, a species that reverses to change direction, accumulated in the light beam, as expected...

  20. Setaria viridis floral-dip: A simple and rapid Agrobacterium-medicated transformation method

    Science.gov (United States)

    Setaria viridis was recently described as a new monocotyledonous model species for C4 photosynthesis research and genetic transformation. It has biological attributes (rapid life cycle, small genome, diploid, short stature and simple growth requirements) that make it suitable for use as a model plan...

  1. Oxygen dynamics and porewater transport in sediments inhabited by the invasive polychaete Marenzelleria viridis

    DEFF Research Database (Denmark)

    Jovanovic, Zeljko; Larsen, Morten; Quintana, Cintia Organo

    2014-01-01

    (rhodamine WT and brilliant blue), we investigated the relationship between irrigation and O2 dynamics in burrows of M. viridis. The investigated animals shifted between 2 modes of ventilation: ciliary pumping for 77% of the time and muscular pumping for 23% of the time. On average, muscular pumping...

  2. The invasive Asian green mussel Perna viridis in South Africa: all ...

    African Journals Online (AJOL)

    The Asian green mussel Perna viridis is an invasive Indo-Pacific species recently reported from South African harbours. To verify the invasion, a phylogenetic (and morphological) analysis of green-shelled mussels (n = 39), found in six South African harbours, was conducted using the mitochondrial cytochrome c oxidase ...

  3. Extract of Indian green mussel, Perna viridis (L.) shows inhibition of blood capillary formation in vitro

    Digital Repository Service at National Institute of Oceanography (India)

    Mirshahi, M.; Mirshahi, P.; Negro, S.; Soria, J.; Sreekumar, P.K.; Kotnala, S.; Therwath, A; Chatterji, A

    The extract of the Indian green mussel (Perna viridis L.) was found to inhibit the formation of endothelial cell capillary tube in a concentration dependent manner in vitro. At a concentration of 5 mg/ml of crude extract, there no formation...

  4. Establishment of primary cell culture from the temperate symbiotic cnidarian, Anemonia viridis.

    Science.gov (United States)

    Barnay-Verdier, Stéphanie; Dall'osso, Diane; Joli, Nathalie; Olivré, Juliette; Priouzeau, Fabrice; Zamoum, Thamilla; Merle, Pierre-Laurent; Furla, Paola

    2013-10-01

    The temperate symbiotic sea anemone Anemonia viridis, a member of the Cnidaria phylum, is a relevant experimental model to investigate the molecular and cellular events involved in the preservation or in the rupture of the symbiosis between the animal cells and their symbiotic microalgae, commonly named zooxanthellae. In order to increase research tools for this model, we developed a primary culture from A. viridis animal cells. By adapting enzymatic dissociation protocols, we isolated animal host cells from a whole tentacle in regeneration state. Each plating resulted in a heterogeneous primary culture consisted of free zooxanthellae and many regular, small rounded and adherent cells (of 3-5 μm diameter). Molecular analyses conducted on primary cultures, maintained for 2 weeks, confirmed a specific signature of A. viridis cells. Further serial dilutions and micromanipulation allowed us to obtain homogenous primary cultures of the small rounded cells, corresponding to A. viridis "epithelial-like cells". The maintenance and the propagation over a 4 weeks period of primary cells provide, for in vitro cnidarian studies, a preliminary step for further investigations on cnidarian cellular pathways notably in regard to symbiosis interactions.

  5. Kleptoplasts photoacclimation state modulates the photobehaviour of the solar-powered sea slug Elysia viridis.

    Science.gov (United States)

    Cartaxana, Paulo; Morelli, Luca; Quintaneiro, Carla; Calado, Gonçalo; Calado, Ricardo; Cruz, Sónia

    2018-04-30

    Some sacoglossan sea slugs incorporate intracellular functional algal chloroplasts (kleptoplasty) for periods ranging from a few days to several months. Whether this association modulates the photobehaviour of solar-powered sea slugs is unknown. In this study, the long-term retention species Elysia viridis showed avoidance of dark independently of light acclimation state. On the contrary, Placida dendritica , which shows non-functional retention of kleptoplasts, showed no preference over dark, low or high light. High light acclimated (HL ac ) E. viridis showed a higher preference for high light than low light acclimated (LL ac ) conspecifics. The position of the lateral folds (parapodia) was modulated by irradiance, with increasing light levels leading to a closure of parapodia and protection of kleptoplasts from high light exposure. Furthermore, closure of parapodia occurred at higher irradiances in HL ac E. viridis Our results strongly indicate that kleptoplasts photoacclimation state modulates the photobehaviour of the solar-powered sea slug E. viridis . © 2018. Published by The Company of Biologists Ltd.

  6. Sex determination in Bonellia viridis (Echiura : Bonelliidae): population dynamics and evolution

    Czech Academy of Sciences Publication Activity Database

    Berec, Luděk; Schembri, P. J.; Boukal S., David

    2005-01-01

    Roč. 108, č. 3 (2005), s. 473-484 ISSN 0030-1299 R&D Projects: GA AV ČR(CZ) KSK6005114; GA AV ČR(CZ) IAB1007201 Institutional research plan: CEZ:AV0Z50070508 Keywords : Bonellia viridis Subject RIV: EH - Ecology, Behaviour Impact factor: 3.309, year: 2005

  7. Content Heavy Metal Pb, Cd In Perna viridis And Sediments In Semarang Bay

    Science.gov (United States)

    Suprapto, D.; Suryanti, S.; Latifah, N.

    2018-02-01

    Waste disposal from human activities, generally contain heavy metals such as Pb and Cd which derived from industrial activities. The aims of the study were to know the concentration of Pb and Cd heavy metals contained in Perna viridis tissue, sediment and water at Semarang Bay. This study was conducted in May 2017 at Semarang Bay. - Samples were collected using purposive sampling method. The heavy metal content in the water and clam was observed using- APHA method and was analyzed using AAS (Atomic Absorption Spectrophotometer). The results showed that concentration of heavy metal of Pb in the water was 0.00-50.5mg/L and the Cd content was of 26.9-51.7 mg/L, whereas the concentration of Pb in the sediment is 445.5-2.053.0mg/L and Cd 963.3-2,150.0 mg/L. Pb content in soft tissue of Perna viridis - is 67.1-1.933.9 mg/L and the concentration of Cd was 203.5-5.787.3 mg/L. The analysis of Pb and Cd in seawater, sediment and soft tissue of Perna viridis according to Enviroment Ministerial decree (KepMenLH ) number 51 of 2004 and applied by NOAA 1999 does not exceed the quality standard, that meant that the Perna viridis has been contaminated by metal Pb it is controversial with the above sentence and Cd. It concluded that the metal content of Pb and Cd in Perna viridis tissue exceeds the quality standard, so it is not suitable to be consumed, especially in high quantity

  8. Modulation of antioxidant and biotransformation enzymes in the gills of Perna viridis (L.) exposed to water accomodate fraction of diesel

    Digital Repository Service at National Institute of Oceanography (India)

    Jena, K.B.; Verlecar, X.N.; Chainy, G.B.N.

    tested for cell damage and antioxidant responses in P. viridis for over 15 day period. The parameters measured included lipid peroxidation (LPX), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR...

  9. Biometric and morphometric studies of Perna viridis and Perna indica along the southwest coast of India: a statistical approach

    Digital Repository Service at National Institute of Oceanography (India)

    Jayalakshmy, K.V.; Nair, M.; DileepKumar, R.; Vijayan, M.

    morphometric gradient groups (spat and adult), indicating the different phenotypic plasticity between them. The factor scores classified P. indica as a unimodal, positively skewed leptokurtic population and P. viridis as a unimodal, negatively skewed...

  10. Response of DNA, proteins, lipids and antioxidant enzymes as measure of toxicity to mercury exposures in green mussel Perna viridis

    Digital Repository Service at National Institute of Oceanography (India)

    Verlecar, X.N.; Jena, K.B.; Chainy, G.B.N.

    Studies on exposures of gills of green-lipped mussel Perna viridis to sublethal levels of mercury (Hg) indicates that oxidative stress marker like lipids peroxidation and protein carbonyl content increase. With the exception of superoxide dismutase...

  11. Hypocholesterolemic Response to Karaya Saponin and Rhodobacter capsulatus in Broiler Chickens

    OpenAIRE

    Afrose, Sadia; Hossain, Md. Sharoare; Maki, Takaaki; Tsujii, Hirotada

    2010-01-01

    Dietary karaya saponin and Rhodobacter capsulatus (R. capsulatus) are known to have hypocholesterolemic actions, as reported in our previous studies. This study examined possible synergistic hypocholesterolemic effects of karaya saponin and R. capsulatus in broilers. A total of 150 broilers were allocated into 10 treatments: control, saponin 25 mg, saponin 50 mg, saponin 75 mg, saponin 25 mg+R. capsulatus 0.2 g, saponin 25 mg+R. capsulatus 0.4 g, saponin 50 mg+R. capsulatus 0.2 g, saponin 50 ...

  12. DNA sequence analysis of the photosynthesis region of Rhodobacter sphaeroides 2.4.1T

    OpenAIRE

    Choudhary, M.; Kaplan, Samuel

    2000-01-01

    This paper describes the DNA sequence of the photosynthesis region of Rhodobacter sphaeroides 2.4.1T. The photosynthesis gene cluster is located within a ~73 kb AseI genomic DNA fragment containing the puf, puhA, cycA and puc operons. A total of 65 open reading frames (ORFs) have been identified, of which 61 showed significant similarity to genes/proteins of other organisms while only four did not reveal any significant sequence similarity to any gene/protein sequences in the database. The da...

  13. Natural high pCO2 increases autotrophy in Anemonia viridis (Anthozoa) as revealed from stable isotope (C, N) analysis

    OpenAIRE

    Horwitz, Rael; Borell, Esther M.; Yam, Ruth; Shemesh, Aldo; Fine, Maoz

    2015-01-01

    Contemporary cnidarian-algae symbioses are challenged by increasing CO2 concentrations (ocean warming and acidification) affecting organisms' biological performance. We examined the natural variability of carbon and nitrogen isotopes in the symbiotic sea anemone Anemonia viridis to investigate dietary shifts (autotrophy/heterotrophy) along a natural pCO2 gradient at the island of Vulcano, Italy. ?13C values for both algal symbionts (Symbiodinium) and host tissue of A. viridis became significa...

  14. Perdas causadas por Coccus viridis (Hemiptera: Coccidae em mudas de Coffea arabica L.

    Directory of Open Access Journals (Sweden)

    Flávio Lemes Fernandes

    2009-08-01

    Full Text Available Coccus viridis (Green danifica plantas jovens e adultas de Coffea arabica Linnaeu. No entanto, nada se sabe sobre a magnitude dos danos causados por esta praga. Assim, este trabalho teve por objetivo estudar as relações entre o ataque de C. viridis e as perdas causadas por este inseto a C. arabica. Este trabalho foi conduzido em casa de vegetação na Universidade Federal de Viçosa. Foram utilizadas sementes da linhagem IAC 15 da variedade “Catuaí vermelho” de café (C. arabica. Para a confecção dos tratamentos esta praga foi criada em casa de vegetação separada do experimento. Os tratamentos foram: plantas infestadas e não infestadas por adultos e ninfas da cochonilha verde. As plantas foram nutridas com solução nutritiva. Durante 110 dias foram avaliados: números de adultos e de ninfas de primeiro, segundo e terceiro ínstares, área foliar, diâmetro do caule, altura das plantas em todas repetições. No final do experimento avaliou-se o peso das raízes, caule, folhas e total. Os pesos das raízes, matéria seca total, área foliar e diâmetro do caule de plantas não atacadas por C. viridis superaram em 1,31; 1,41; 1,50 e 8,93 vezes, respectivamente o peso de plantas atacadas. As variáveis selecionadas foram: diâmetro do caule (cm, área foliar (cm², peso de raízes (g, ninfas, adultos e total das cochonilhas. Concluindo que a planta de C. arabica é afetada de forma diferente entre seus órgãos e que a ninfa de terceiro ínstar e adultos são as fases que mais causam danos a C. arabica.Losses Caused by Coccus viridis (Green (Hemiptera: Coccidae on Seedlings of Coffea arabica L.Abstract. Coccus viridis (Green cause losses on seedling and old plants of Coffea arabica (Green. However, nothing is known about of the damages caused by this pest. Thus, the objective of this work was to evaluate the relations between atack of C. viridis and the losses caused by this insect. on C. arabica. This work was conduced in greenhouse at

  15. Assessment of pollution in road runoff using a Bufo viridis biological assay.

    Science.gov (United States)

    Dorchin, A; Shanas, U

    2010-12-01

    Road runoff is a major source of environmental pollution, significantly threatening nearby aquatic habitats. Chemical analyses indicate high pollutant concentrations in the road's "first flush", but bioassays are more advantageous for addressing the cumulative effects of the numerous pollutants within the runoff. We used Bufo viridis embryos and larvae to assess the toxicity of road runoff from two major highways in Israel. We show, for the first time, that exposure to midseason runoff not only has an adverse effect on growth and development rates of B. viridis larvae but can also lead to increased rates of morphological deformations. Seasonal first flushes, despite having higher metal concentrations, did not adversely affect the toad larvae, apparently due to a counter effect of organic matter that potentially served as a supplementary energy resource. Road runoff can be a major cause for a qualitative decrease in the quality of aquatic habitats threatening amphibians in Israel. Copyright © 2010 Elsevier Ltd. All rights reserved.

  16. Two dimensional crystals of LH2 light-harvesting complexes from Ectothiorhodospira sp. and Rhodobacter capsulatus investigated by electron microscopy

    NARCIS (Netherlands)

    Oling, Frank; Boekema, EJ; deZarate, IO; Visschers, R; vanGrondelle, R; Keegstra, W; Brisson, A; Picorel, R

    1996-01-01

    Two-dimensional crystals of LH2 (B800-850) light-harvesting complexes from Ectothiorhodospira sp, and Rhodobacter capsulatus were obtained by reconstitution of purified protein into phospholipid vesicles and characterized by electron microscopy. The size of the crystals was up to several

  17. A new pathway for transmembrane electron transfer in photosynthetic reaction centers of Rhodobacter sphaeroides not involving the excited special pair.

    NARCIS (Netherlands)

    van Brederode, M.E.; Jones, M.R.; van Mourik, F.; van Stokkum, I.H.M.; van Grondelle, R.

    1997-01-01

    It is generally accepted that electron transfer in bacterial photosynthesis is driven by the first singlet excited state of a special pair of bacteriochlorophylls (P*). We have examined the first steps of electron transfer in a mutant of the Rhodobacter sphaeroides reaction center in which charge

  18. A new pathway for transmembrane electron transfer in photosyntetic reaction centers of Rhodobacter sphaeroides not involving the excited special pair.

    NARCIS (Netherlands)

    van Brederode, M.E.; Jones, M.R.; van Mourik, F.; van Stokkum, I.H.M.; van Grondelle, R.

    1997-01-01

    It is generally accepted that electron transfer in bacterial photosynthesis is driven by the first singlet excited state of a special pair of bacteriochlorophylls (P*). We have examined the first steps of electron transfer in a mutant of the Rhodobacter sphaeroides reaction center in which charge

  19. Direct Visualization of Exciton Reequilibration in the LH1 and LH2 Complexes of Rhodobacter sphaeroides by Multipulse Spectroscopy

    NARCIS (Netherlands)

    Cohen Stuart, T.A.; Vengris, M.; Novoderezhkin, V.I.; Cogdell, R.J.; Hunter, C.N.; van Grondelle, R.

    2011-01-01

    The dynamics of the excited states of the light-harvesting complexes LH1 and LH2 of Rhodobacter sphaeroides are governed, mainly, by the excitonic nature of these ring-systems. In a pump-dump-probe experiment, the first pulse promotes LH1 or LH2 to its excited state and the second pulse dumps a

  20. Hydrogen production by using Rhodobacter capsulatus mutants with genetically modified electron transfer chains

    Energy Technology Data Exchange (ETDEWEB)

    OEztuerk, Yavuz; Yuecel, Meral; Guenduez, Ufuk [Department of Biology, Middle East Technical University, Ankara (Turkey); Daldal, Fevzi [Department of Biology, Plant Science Institute, University of Pennsylvania, Philadelphia, PA 19104-6018 (United States); Mandaci, Sevnur [TUEBITAK Research Institute for Genetic Engineering and Biotechnology, Gebze Kocaeli 41470 (Turkey); Tuerker, Lemi [Department of Chemistry, Middle East Technical University, Ankara (Turkey); Eroglu, Inci [Department of Chemical Engineering, Middle East Technical University, Ankara (Turkey)

    2006-09-15

    In Rhodobacter capsulatus excess reducing equivalents generated by organic acid oxidation is consumed to reduce protons into hydrogen by the activity of nitrogenase. Nitrogenase serves as a redox-balancing tool and is activated by the RegB/RegA global regulatory system during photosynthetic growth. The terminal cytochrome cbb{sub 3} oxidase and the redox state of the cyclic photosynthetic electron transfer chain serve redox signaling to the RegB/RegA regulatory systems in Rhodobacter. In this study, hydrogen production of various R. capsulatus strains harboring the genetically modified electron carrier cytochromes or lacking the cyt cbb{sub 3} oxidase or the quinol oxidase were compared with the wild type. The results indicated that hydrogen production of mutant strains with modified electron carrier cytochromes decreased 3- to 4-fold, but the rate of hydrogen production increased significantly in a cbb{sub 3}{sup -} mutant. Moreover, hydrogen production efficiency of various R. capsulatus strains further increased by inactivation of uptake hydrogenase genes. (author)

  1. Comparative performance of the mussels Perna perna and Perna viridis, cultivated at four different depths

    Directory of Open Access Journals (Sweden)

    Marielyn García

    Full Text Available Abstract This study aims to evaluate the effect of environmental variability on the growth and survival of the subtropical and tropical mussels Perna perna and Perna viridis at four different culture depths in the Gulf of Cariaco during an annual cycle. Juveniles of P. perna (39.1±1.88 mm in shell length and P. viridis (36.7±1.87 mm were sown on nylon ropes (3/4" and suspended from a raft at 1, 3, 6 and 9 m depths. Every six weeks, three replicates of each species were sampled (10 individuals per replicate at each depth. Growth parameters were determined: mass and shell length, dry mass of soft tissues as well as fouling and survival rates. Temperature, transparency, chlorophyll a, oxygen, salinity and particulate organic and inorganic matter were recorded at each culture depth for the purpose of relating growth and survival to environmental change. The results show that the growth of both species was linked to the environment, especially with regard to the influence of the food and temperature. A period of stagnant growth of P. perna was associated with the higher temperature and lower phytoplankton biomass that is characteristic of the season with prevalent water column stratification (August-November 2007. By contrast, the growth of P. viridis did not stagnate, although it was gradual and relatively lower. At the end, P. perna achieved higher growth rates than P. viridis. Possible culture strategies to improve the production of both mussel species are discussed.

  2. Phytolith analysis for differentiating between foxtail millet (Setaria italica) and green foxtail (Setaria viridis).

    OpenAIRE

    Jianping Zhang; Houyuan Lu; Naiqin Wu; Xiaoyan Yang; Xianmin Diao

    2011-01-01

    Foxtail millet (Setaria italica) is one of the oldest domesticated cereal crops in Eurasia, but identifying foxtail millets, especially in charred grains, and differentiating it from its wild ancestor, green foxtail (Setaria viridis), in the archaeobotanical remains, is still problematic. Phytolithic analysis provides a meaningful method for identifying this important crop. In this paper, the silicon structure patterns in the glumes, lemmas, and paleas from inflorescence bracts in 16 modern p...

  3. Disseminated Mycobacterium celatum infection in a white-tailed trogon (Trogon viridis)

    DEFF Research Database (Denmark)

    Bertelsen, M. F.; Grondahl, C.; Giese, Steen Bjørck

    2006-01-01

    An adult female white-tailed trogon (Trogon viridis) was presented with abdominal enlargement and hard subcutaneous masses. Necropsy findings included bony masses extending from skeletal structures, disseminated pale foci in the liver, and a pale mass in the kidney. Histological examination revea...... revealed multifocal to coalescing granulomatous inflammation in the bone, liver, kidney, lung and spleen. Mycobacterium celatum was isolated from the liver and identified by DNA sequencing. This is the first report of M. celatum infection in an avian species....

  4. Antinociceptive and antipyretic activities of Amaranthus viridis Linn. in different experimental models

    Directory of Open Access Journals (Sweden)

    Kumar Ashok B.S.

    2010-01-01

    Full Text Available The methanolic extract of the whole plant extract of Amaranthus viridis L (MEAV was screened for antinociceptive activity using the acetic acid writhing test, hot plate test and tail immersion test in mice and for antipyretic activity using the yeast-induced pyrexia method in rats, at doses of 200 and 400 mg/kg body weight. Significant (p<0.01 dose-dependent antinociceptive and antipyretic properties were observed with 200 and 400 mg/kg.

  5. Setaria viridis as a model system to advance millet genetics and genomics

    Directory of Open Access Journals (Sweden)

    Pu Huang

    2016-11-01

    Full Text Available Millet is a common name for a group of polyphyletic, small-seeded cereal crops that include pearl, finger and foxtail millet. Millet species are an important source of calories for many societies, often in developing countries. Compared to major cereal crops such as rice and maize, millets are generally better adapted to dry and hot environments. Despite their food security value, the genetic architecture of agronomically important traits in millets, including both morphological traits and climate resilience remains poorly studied. These complex traits have been challenging to dissect in large part because of the lack of sufficient genetic tools and resources. In this article, we review the phylogenetic relationship among various millet species and discuss the value of a genetic model system for millet research. We propose that a broader adoption of green foxtail (Setaria viridis as a model system for millets could greatly accelerate the pace of gene discovery in the millets, and summarize available and emerging resources in S. viridis and its domesticated relative S. italica. These resources have value in forward genetics, reverse genetics and high throughput phenotyping. We describe methods and strategies to best utilize these resources to facilitate the genetic dissection of complex traits. We envision that coupling cutting-edge technologies and the use of S. viridis for gene discovery will accelerate genetic research in millets in general. This will enable strategies and provide opportunities to increase productivity, especially in the semi-arid tropics of Asia and Africa where millets are staple food crop.

  6. Setaria viridis as a Model System to Advance Millet Genetics and Genomics.

    Science.gov (United States)

    Huang, Pu; Shyu, Christine; Coelho, Carla P; Cao, Yingying; Brutnell, Thomas P

    2016-01-01

    Millet is a common name for a group of polyphyletic, small-seeded cereal crops that include pearl, finger and foxtail millet. Millet species are an important source of calories for many societies, often in developing countries. Compared to major cereal crops such as rice and maize, millets are generally better adapted to dry and hot environments. Despite their food security value, the genetic architecture of agronomically important traits in millets, including both morphological traits and climate resilience remains poorly studied. These complex traits have been challenging to dissect in large part because of the lack of sufficient genetic tools and resources. In this article, we review the phylogenetic relationship among various millet species and discuss the value of a genetic model system for millet research. We propose that a broader adoption of green foxtail ( Setaria viridis ) as a model system for millets could greatly accelerate the pace of gene discovery in the millets, and summarize available and emerging resources in S. viridis and its domesticated relative S. italica . These resources have value in forward genetics, reverse genetics and high throughput phenotyping. We describe methods and strategies to best utilize these resources to facilitate the genetic dissection of complex traits. We envision that coupling cutting-edge technologies and the use of S. viridis for gene discovery will accelerate genetic research in millets in general. This will enable strategies and provide opportunities to increase productivity, especially in the semi-arid tropics of Asia and Africa where millets are staple food crops.

  7. Setaria viridis as a Model System to Advance Millet Genetics and Genomics

    Science.gov (United States)

    Huang, Pu; Shyu, Christine; Coelho, Carla P.; Cao, Yingying; Brutnell, Thomas P.

    2016-01-01

    Millet is a common name for a group of polyphyletic, small-seeded cereal crops that include pearl, finger and foxtail millet. Millet species are an important source of calories for many societies, often in developing countries. Compared to major cereal crops such as rice and maize, millets are generally better adapted to dry and hot environments. Despite their food security value, the genetic architecture of agronomically important traits in millets, including both morphological traits and climate resilience remains poorly studied. These complex traits have been challenging to dissect in large part because of the lack of sufficient genetic tools and resources. In this article, we review the phylogenetic relationship among various millet species and discuss the value of a genetic model system for millet research. We propose that a broader adoption of green foxtail (Setaria viridis) as a model system for millets could greatly accelerate the pace of gene discovery in the millets, and summarize available and emerging resources in S. viridis and its domesticated relative S. italica. These resources have value in forward genetics, reverse genetics and high throughput phenotyping. We describe methods and strategies to best utilize these resources to facilitate the genetic dissection of complex traits. We envision that coupling cutting-edge technologies and the use of S. viridis for gene discovery will accelerate genetic research in millets in general. This will enable strategies and provide opportunities to increase productivity, especially in the semi-arid tropics of Asia and Africa where millets are staple food crops. PMID:27965689

  8. Setaria viridis and Setaria italica, model genetic systems for the Panicoid grasses.

    Science.gov (United States)

    Li, Pinghua; Brutnell, Thomas P

    2011-05-01

    Setaria italica and its wild ancestor Setaria viridis are diploid C(4) grasses with small genomes of ∼515 Mb. Both species have attributes that make them attractive as model systems. Setaria italica is a grain crop widely grown in Northern China and India that is closely related to the major food and feed crops maize and sorghum. A large collection of S. italica accessions are available and thus opportunities exist for association mapping and allele mining for novel variants that will have direct application in agriculture. Setaria viridis is the weedy relative of S. italica with many attributes suitable for genetic analyses including a small stature, rapid life cycle, and prolific seed production. Setaria sp. are morphologically similar to most of the Panicoideae grasses, including major biofuel feedstocks, switchgrass (Panicum virgatum) and Miscanthus (Miscanthus giganteus). They are broadly distributed geographically and occupy diverse ecological niches. The cross-compatibility of S. italica and S. viridis also suggests that gene flow is likely between wild and domesticated accessions. In addition to serving as excellent models for C(4) photosynthesis, these grasses provide novel opportunities to study abiotic stress tolerance and as models for bioenergy feedstocks.

  9. Parasites and pathological condition in Green mussel Perna viridis Linnaeus, 1758 from western Johor Straits, Malaysia

    Science.gov (United States)

    Azmi, Nur-Fauzana; Ghaffar, Mazlan Abd.; Cob, Zaidi Che

    2018-04-01

    This study describes the parasites and pathological condition of infected organ of the green mussel Perna viridis from Merambong Shoal, Western Johor Straits, Malaysia. Samples were collected randomly in November and December 2013. Histopathology techniques using Masson's Trichrome staining protocol were performed and the thin sections were observed under light microscope. Result showed that gonad was the most infected organ followed by the digestive tubule, adductor muscle, intestine and mantle tissue. The parasites (apicomplexa) such as spore-like Nematopsis, macrogamont-like coccidian, mature oocyst-like coccidian, unidentified coccidian and protozoan were found in the adductor muscle, gonad and mantle. Meanwhile, the pathological conditions were found in all infected organs except the gill, such as particular melanin deposits in cytoplasm, Rickettsia-like or Chlamydiae organism and bacteria-like inclusions. Haemocytic infiltrations were found in the surrounding connective tissues of all infected organs. However, these light infections are not causing morbidity and mortalityof the green mussel P.viridis. This study provides baseline information on health profile of the green mussel P.viridis. Further investigations are needed particularly on parasite species identification and their ecology. Understanding of the morphology and pathology of parasites infecting mollusks are very important for management of the resources.

  10. Timescales of Coherent Dynamics in the Light Harvesting Complex 2 (LH2) of Rhodobacter sphaeroides.

    Science.gov (United States)

    Fidler, Andrew F; Singh, Ved P; Long, Phillip D; Dahlberg, Peter D; Engel, Gregory S

    2013-05-02

    The initial dynamics of energy transfer in the light harvesting complex 2 from Rhodobacter sphaeroides were investigated with polarization controlled two-dimensional spectroscopy. This method allows only the coherent electronic motions to be observed revealing the timescale of dephasing among the excited states. We observe persistent coherence among all states and assign ensemble dephasing rates for the various coherences. A simple model is utilized to connect the spectroscopic transitions to the molecular structure, allowing us to distinguish coherences between the two rings of chromophores and coherences within the rings. We also compare dephasing rates between excited states to dephasing rates between the ground and excited states, revealing that the coherences between excited states dephase on a slower timescale than coherences between the ground and excited states.

  11. In vitro assembly of a prohead-like structure of the Rhodobacter capsulatus gene transfer agent

    International Nuclear Information System (INIS)

    Spano, Anthony J.; Chen, Frank S.; Goodman, Benjamin E.; Sabat, Agnes E.; Simon, Martha N.; Wall, Joseph S.; Correia, John J.; McIvor, Wilson; Newcomb, William W.; Brown, Jay C.; Schnur, Joel M.; Lebedev, Nikolai

    2007-01-01

    The gene transfer agent (GTA) is a phage-like particle capable of exchanging double-stranded DNA fragments between cells of the photosynthetic bacterium Rhodobacter capsulatus. Here we show that the major capsid protein of GTA, expressed in E. coli, can be assembled into prohead-like structures in the presence of calcium ions in vitro. Transmission electron microscopy (TEM) of uranyl acetate staining material and thin sections of glutaraldehyde-fixed material demonstrates that these associates have spherical structures with diameters in the range of 27-35 nm. The analysis of scanning TEM images revealed particles of mass ∼ 4.3 MDa, representing 101 ± 11 copies of the monomeric subunit. The establishment of this simple and rapid method to form prohead-like particles permits the GTA system to be used for genome manipulation within the photosynthetic bacterium, for specific targeted drug delivery, and for the construction of biologically based distributed autonomous sensors for environmental monitoring

  12. Improved hydrogen production by uptake hydrogenase deficient mutant strain of Rhodobacter sphaeroides O.U.001

    Energy Technology Data Exchange (ETDEWEB)

    Kars, Goekhan; Guenduez, Ufuk; Yuecel, Meral [Department of Biological Sciences, Middle East Technical University, 06531 Ankara (Turkey); Rakhely, Gabor; Kovacs, Kornel L. [Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged (Hungary); Eroglu, Inci [Department of Chemical Engineering, Middle East Technical University, 06531 Ankara (Turkey)

    2008-06-15

    Rhodobacter sphaeroides O.U.001 is a purple non-sulfur bacterium producing hydrogen under photoheterotrophic conditions. Hydrogen is produced by Mo-nitrogenase enzyme and substantial amount of H{sub 2} is reoxidized by a membrane-bound uptake hydrogenase in the wild type strain. To improve the hydrogen producing capacity of the cells, a suicide vector containing a gentamicin cassette in the hupSL genes was introduced into R. sphaeroiodes O.U.001 and the uptake hydrogenase genes were destroyed by site directed mutagenesis. The correct integration of the construct was confirmed by uptake hydrogenase activity measurement, PCR and subsequent sequence analysis. The wild type and the mutant cells showed similar growth patterns but the total volume of hydrogen gas evolved by the mutant was 20% higher than that of the wild type strain. This result demonstrated that the hydrogen produced by the nitrogenase was not consumed by uptake hydrogenase leading to higher hydrogen production. (author)

  13. Characterization of glutathione peroxidase diversity in the symbiotic sea anemone Anemonia viridis.

    Science.gov (United States)

    Pey, Alexis; Zamoum, Thamilla; Christen, Richard; Merle, Pierre-Laurent; Furla, Paola

    2017-01-01

    Cnidarians living in symbiosis with photosynthetic dinoflagellates (commonly named zooxanthellae) are exposed to high concentrations of reactive oxygen species (ROS) upon illumination. To quench ROS production, both the cnidarian host and zooxanthellae express a full suite of antioxidant enzymes. Studying antioxidative balance is therefore crucial to understanding how symbiotic cnidarians cope with ROS production. We characterized glutathione peroxidases (GPx) in the symbiotic cnidarian Anemonia viridis by analysis of their isoform diversity, their activity distribution in the three cellular compartments (ectoderm, endoderm and zooxanthellae) and their involvement in the response to thermal stress. We identified a GPx repertoire through a phylogenetic analysis showing 7 GPx transcripts belonging to the A. viridis host and 4 GPx transcripts strongly related to Symbiodinium sp. The biochemical approach, used for the first time with a cnidarian species, allowed the identification of GPx activity in the three cellular compartments and in the animal mitochondrial fraction, and revealed a high GPx electrophoretic diversity. The symbiotic lifestyle of zooxanthellae requires more GPx activity and diversity than that of free-living species. Heat stress induced no modification of GPx activities. We highlight a high GPx diversity in A. viridis tissues by genomic and biochemical approaches. GPx activities represent an overall constitutive enzymatic pattern inherent to symbiotic lifestyle adaptation. This work allows the characterization of the GPx family in a symbiotic cnidarian and establishes a foundation for future studies of GPx in symbiotic cnidarians. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  14. Overexpression of BdMATE Gene Improves Aluminum Tolerance in Setaria viridis

    Directory of Open Access Journals (Sweden)

    Ana P. Ribeiro

    2017-06-01

    Full Text Available Acidic soils are distributed worldwide, predominantly in tropical and subtropical areas, reaching around 50% of the arable soil. This type of soil strongly reduces crop production, mainly because of the presence of aluminum, which has its solubility increased at low pH levels. A well-known physiological mechanism used by plants to cope with Al stress involves activation of membrane transporters responsible for organic acid anions secretion from the root apex to the rhizosphere, which chelate Al, preventing its absorption by roots. In sorghum, a membrane transporter gene belonging to multidrug and toxic compound extrusion (MATE family was identified and characterized as an aluminum-activated citrate transporter gene responsible for Al tolerance in this crop. Setaria viridis is an emerging model for C4 species and it is an important model to validate some genes for further C4 crops transformation, such as sugarcane, maize, and wheat. In the present work, Setaria viridis was used as a model plant to overexpress a newly identified MATE gene from Brachypodium distachyon (BdMATE, closely related to SbMATE, for aluminum tolerance assays. Transgenic S. viridis plants overexpressing a BdMATE presented an improved Al tolerance phenotype, characterized by sustained root growth and exclusion of aluminum from the root apex in transgenic plants, as confirmed by hematoxylin assay. In addition, transgenic plants showed higher root citrate exudation into the rhizosphere, suggesting that Al tolerance improvement in these plants could be related to the chelation of the metal by the organic acid anion. These results suggest that BdMATE gene can be used to transform C4 crops of economic importance with improved aluminum tolerance.

  15. Is Echinometra viridis facilitating a phase shift on an Acropora cervicornis patch reef in Belize?

    Science.gov (United States)

    Stefanic, C. M.; Greer, L.; Norvell, D.; Benson, W.; Curran, H.

    2012-12-01

    Coral reef health is in rapid decline across the Caribbean due to a number of anthropogenic and natural disturbances. A phase shift from coral- to macroalgae-dominant reefs is pervasive and has been well documented. Acropora cervicornis (Staghorn Coral) has been particularly affected by this shift due to mass mortality of this species since the 1980s. In recent years few Caribbean A. cervicornis refugia have been documented. This study characterizes the relationship between coral and grazing urchins on a rare patch reef system dominated by A. cervicornis off the coast of Belize. To assess relative abundance of live A. cervicornis and the urchin Echinometra viridis, photographs and urchin abundance data were collected from 132 meter square quadrats along five transects across the reef. Photographs were digitized and manually segmented using Adobe Illustrator, and percent live coral cover and branch tip densities were calculated using Matlab. Mean percent live coral cover across all transects was 24.4 % with a high of 65% live coral per meter square. Average urchin density was 18.5 per quadrat, with an average density per transect ranging from 22.1 to 0.5 per quadrat. Up to over 400 live A. cervicornis branch tips per quadrat were observed. Data show a positive correlation between E. viridis abundance and live A. cervicornis, suggesting that these urchins are facilitating recovery or persistence of this endangered coral species. These results suggest the relationship between E. viridis and A. cervicornis could be a key element in a future reversal of the coral to macroalgae phase shift on some Caribbean coral reefs.

  16. Karyological and flow cytometric evidence of triploid specimens in Bufo viridis (Amphibia Anura

    Directory of Open Access Journals (Sweden)

    D Cavallo

    2010-01-01

    Full Text Available Karyological and flow cytometric (FCM analyses were performed on a group of 14 green toads of the Bufo viridis species from seven Eurasian populations. Both approaches gave concordant results concerning the DNA ploidy level. All the populations examined were represented exclusively by diploid or tetraploid specimens, except one, where triploids were found. Results evidenced an interpopulation variability in DNA content against the same ploidy level, as well as an unusually high number of triploids in a particular reproductive place. The origin of polyploidy and the presence and persistence of a high number of triploids in a particular population are discussed.

  17. Propagação Assexuada de Chacrona (Psychotria viridis Ruiz & Pavon) Via Estaquia Foliar

    OpenAIRE

    Salgado, Moisés Pereira Galvão; Universidade de Taubaté - UNITAU; Furlan, Marcos Roberto; Universidade de Taubaté; Aoyama, Elisa Mitsuko; Universidade Federal do Espírito Santo - UFES; Rodrigues, Eliana; Universidade Federal de São Paulo; Cruz, Lilian Pereira; Universidade Estadual de Campinas - UNICAMP

    2011-01-01

    This study aimed to assess the asexual propagation of Psychotria viridis by leaf cuttings. The treatments were: A - Whole leaf cuttings, B - leaf cuttings with the top third cut off; C - with the lower third of the cuttings removed; D - with cuts on the primary vein of leaf cuttings, and E - poles with cuts on the leaf ’s secondary veins. The cuttings were immersed in distilled water for a period of 70 days. In all the treatments, the rooting was observed to occur in the region of the cut, or...

  18. High speed translocation of /sup 86/Rb in the phloem of Tradescantia viridis

    Energy Technology Data Exchange (ETDEWEB)

    Penot, M.

    1976-01-01

    An autoradiographic study of the rooted shoots of Tradescantia viridis showed a high speed translocation of /sup 86/Rb applied to a leaf for short periods of time (5 to 2.5 min). The speed of this translocation (between 840 and 1.440 cm h/sup -1/) speaks for the existence of a very rapid phloem component translocating ions to an active sink, represented here by the growing roots. Pretreatment with cycloheximide (48 h, 50 mg 1/sup -1/) decreases the quantity of this long distance transport but not the velocity.

  19. Peucetia viridis (Blackwall, 1858), caracteres y discusión (Aranae, Oxyopidae)

    OpenAIRE

    Barrientos Alfageme, José Antonio

    1991-01-01

    New records of the type-species of the genus Peucetia from the south of the Iberian Peninsula, near the Mediterranean Sea, confirm its presence in Europe. P. viridis has been recently the subject of taxonomical confussion. In this paper a more complete description of the species is proposed, illustraded with drawings of its general aspect and genital organs. Algunas citas nuevas de la banda mediterránea, en el sur de la Península Ibérica, confirman la presencia en Europa de la especie-tipo...

  20. Occurrence of the alien nudibranch Melibe viridis (Kelaart, 1858 (Opisthobranchia, Tethydidae, in the Maltese Islands

    Directory of Open Access Journals (Sweden)

    J.A. BORG

    2009-06-01

    Full Text Available The alien dendronotacean nudibranch Melibe viridis (Kelaart, 1858, a tropical Indo-Pacific species that seems to have been introduced by shipping into the Mediterranean via the Suez Canal, and which has established populations in Greece, Turkey, Cyprus, Montenegro, Croatia, NW Sicily, southern peninsular Italy and Djerba Island in the Gulf of Gabes, is recorded for the first time from Malta. A thriving population was observed on a soft sediment bottom at a depth of 18-20 m off the western coast of the island of Comino (Maltese Islands. It is suggested that this species was introduced into Malta due to a natural range expansion of surrounding populations.

  1. Nidovirus-Associated Proliferative Pneumonia in the Green Tree Python (Morelia viridis)

    Science.gov (United States)

    Dervas, Eva; Hepojoki, Jussi; Laimbacher, Andrea; Romero-Palomo, Fernando; Jelinek, Christine; Keller, Saskia; Smura, Teemu; Hetzel, Udo

    2017-01-01

    ABSTRACT In 2014 we observed a noticeable increase in the number of sudden deaths among green tree pythons (Morelia viridis). Pathological examination revealed the accumulation of mucoid material within the airways and lungs in association with enlargement of the entire lung. We performed a full necropsy and histological examination on 12 affected green tree pythons from 7 different breeders to characterize the pathogenesis of this mucinous pneumonia. By histology we could show a marked hyperplasia of the airway epithelium and of faveolar type II pneumocytes. Since routine microbiological tests failed to identify a causative agent, we studied lung tissue samples from a few diseased snakes by next-generation sequencing (NGS). From the NGS data we could assemble a piece of RNA genome whose sequence was pythons and Indian pythons. We then employed reverse transcription-PCR to demonstrate the presence of the novel nidovirus in all diseased snakes. To attempt virus isolation, we established primary cultures of Morelia viridis liver and brain cells, which we inoculated with homogenates of lung tissue from infected individuals. Ultrastructural examination of concentrated cell culture supernatants showed the presence of nidovirus particles, and subsequent NGS analysis yielded the full genome of the novel virus Morelia viridis nidovirus (MVNV). We then generated an antibody against MVNV nucleoprotein, which we used alongside RNA in situ hybridization to demonstrate viral antigen and RNA in the affected lungs. This suggests that in natural infection MVNV damages the respiratory tract epithelium, which then results in epithelial hyperplasia, most likely as an exaggerated regenerative attempt in association with increased epithelial turnover. IMPORTANCE Novel nidoviruses associated with severe respiratory disease were fairly recently identified in ball pythons and Indian pythons. Herein we report on the isolation and identification of a further nidovirus from green tree

  2. Structural and Phylogenetic Analysis of Rhodobacter capsulatus NifF: Uncovering General Features of Nitrogen-fixation (nif-Flavodoxins

    Directory of Open Access Journals (Sweden)

    Inmaculada Pérez-Dorado

    2013-01-01

    Full Text Available Analysis of the crystal structure of NifF from Rhodobacter capsulatus and its homologues reported so far reflects the existence of unique structural features in nif flavodoxins: a leucine at the re face of the isoalloxazine, an eight-residue insertion at the C-terminus of the 50’s loop and a remarkable difference in the electrostatic potential surface with respect to non-nif flavodoxins. A phylogenetic study on 64 sequences from 52 bacterial species revealed four clusters, including different functional prototypes, correlating the previously defined as “short-chain” with the firmicutes flavodoxins and the “long-chain” with gram-negative species. The comparison of Rhodobacter NifF structure with other bacterial flavodoxin prototypes discloses the concurrence of specific features of these functional electron donors to nitrogenase.

  3. Structural and phylogenetic analysis of Rhodobacter capsulatus NifF: uncovering general features of nitrogen-fixation (nif)-flavodoxins.

    Science.gov (United States)

    Pérez-Dorado, Inmaculada; Bortolotti, Ana; Cortez, Néstor; Hermoso, Juan A

    2013-01-09

    Analysis of the crystal structure of NifF from Rhodobacter capsulatus and its homologues reported so far reflects the existence of unique structural features in nif flavodoxins: a leucine at the re face of the isoalloxazine, an eight-residue insertion at the C-terminus of the 50's loop and a remarkable difference in the electrostatic potential surface with respect to non-nif flavodoxins. A phylogenetic study on 64 sequences from 52 bacterial species revealed four clusters, including different functional prototypes, correlating the previously defined as "short-chain" with the firmicutes flavodoxins and the "long-chain" with gram-negative species. The comparison of Rhodobacter NifF structure with other bacterial flavodoxin prototypes discloses the concurrence of specific features of these functional electron donors to nitrogenase.

  4. The relationship of heavy metals and condition indices of green-lipped mussel perna viridis from contaminated and uncontaminated environments

    International Nuclear Information System (INIS)

    Ahmad Ismail; Yap Chee Kong

    1999-01-01

    Heavy metal concentrations and condition indices of green-fipped mussel Perna viridis were detemiined at two different sites of Peninsular Malaysia. Significant negative correlations (p< 0.001) between condition indices and heavy metals were observed. Samples from Kuala Perlis which relatively showed high heavy metals concentrations in mussels exhibited lower condition index while Kg. Tg. Batu with lower heavy metal levels, showed higher condition index. The environmental stress is believed to be responsible for the different physiological index in green-fipped mussel P. viridis. (author)

  5. Open reading frame 176 in the photosynthesis gene cluster of Rhodobacter capsulatus encodes idi, a gene for isopentenyl diphosphate isomerase.

    OpenAIRE

    Hahn, F M; Baker, J A; Poulter, C D

    1996-01-01

    Isopentenyl diphosphate (IPP) isomerase catalyzes an essential activation step in the isoprenoid biosynthetic pathway. A database search based on probes from the highly conserved regions in three eukaryotic IPP isomerases revealed substantial similarity with ORF176 in the photosynthesis gene cluster in Rhodobacter capsulatus. The open reading frame was cloned into an Escherichia coli expression vector. The encoded 20-kDa protein, which was purified in two steps by ion exchange and hydrophobic...

  6. Structure of the dimeric PufX-containing core complex of Rhodobacter blasticus by in situ atomic force microscopy.

    Science.gov (United States)

    Scheuring, Simon; Busselez, Johan; Lévy, Daniel

    2005-01-14

    We have studied photosynthetic membranes of wild type Rhodobacter blasticus, a closely related strain to the well studied Rhodobacter sphaeroides, using atomic force microscopy. High-resolution atomic force microscopy topographs of both cytoplasmic and periplasmic surfaces of LH2 and RC-LH1-PufX (RC, reaction center) complexes were acquired in situ. The LH2 is a nonameric ring inserted into the membrane with the 9-fold axis perpendicular to the plane. The core complex is an S-shaped dimer composed of two RCs, each encircled by 13 LH1 alpha/beta-heterodimers, and two PufXs. The LH1 assembly is an open ellipse with a topography-free gap of approximately 25 A. The two PufXs, one of each core, are located at the dimer center. Based on our data, we propose a model of the core complex, which provides explanation for the PufX-induced dimerization of the Rhodobacter core complex. The QB site is located facing a approximately 25-A wide gap within LH1, explaining the PufX-favored quinone passage in and out of the core complex.

  7. Accumulation, distribution and excretion of 134Cs and 65Zn by the green mussels (Perna Viridis)

    International Nuclear Information System (INIS)

    Chen Shunhua; Zhong Chuangguang; Yan Yuanyi; Zhao Xiaokui; Peng Yefang; Shi Qiong

    1997-10-01

    Two important radionuclides 134 Cs and 65 Zn were applied to study the accumulation, distribution and excretion of radioactive nuclides in organs and tissues of green mussel Perna Viridis. the results showed that the uptake rate of 134 Cs by green mussels was very low and the concentration factor (CF) for 134 Cs in the byssus approximated to 1. This CF value was lower than that of other tissues and organs of mussels, but its excretion rate was much higher than that of soft tissues. It was also found that the byssus of mussels had a special ability to accumulate 65 Zn. Concentration factor (CF) for 65 Zn in the byssus could reach as high as 900, which was much higher than that of any other tissues. However, its excretion rate was lower than that of other tissues and organs. The uptake rate of 65 Zn by soft tissues was markedly higher than that of 134 Cs. The mussels could also highly concentrate the low level 65 Zn even if specific activity of 65 Zn was very low in the environmental seawater. Results of radioactive trace experiments showed that the absorption of 134 Cs and 65 Zn by Perna Viridis was selective

  8. Chlorogenic acid, rutin and hyperoside content in Fragaria vesca, F. viridis and F. moschata in Lithuania.

    Science.gov (United States)

    Bagdonaite, Edita; Jakstas, Valdas; Raudonis, Raimondas; Janulis, Valdimaras

    2013-01-01

    In Lithuania, two species of the genus Fragaria L. (Rosaceae), F. vesca L. and F. viridis Weston, occur naturally in the wild and two others, F. moschata Weston and F. × ananassa Duchesne ex Rozier are found escaped from cultivation. The main objective of this study was to establish the variation pattern in the content of chlorogenic acid, rutin and hyperoside in leaves and fruits of the native Lithuanian species. In this work, the chemical polymorphisms of different Fragaria species were studied by growing plants side by side under the same cultivated field conditions. F. vesca fruits had the highest rutin (1.38 ± 0.19 mg g(-1) DM), hyperoside (0.69 ± 0.10 mg g(-1) DM) and chlorogenic acid (2.25 ± 0.34 mg g(-1) DM) content, followed by F. viridis and F. moschata. Our results showed that the leaves should be taken into account as important rutin and hyperoside contributors for strawberries.

  9. Fusion and retrotransposition events in the evolution of the sea anemone Anemonia viridis neurotoxin genes.

    Science.gov (United States)

    Moran, Yehu; Weinberger, Hagar; Lazarus, Nimrod; Gur, Maya; Kahn, Roy; Gordon, Dalia; Gurevitz, Michael

    2009-08-01

    Sea anemones are sessile predators that use a variety of toxins to paralyze prey and foe. Among these toxins, Types I, II and III are short peptides that affect voltage-gated sodium channels. Anemonia viridis is the only sea anemone species that produces both Types I and III neurotoxin. Although the two toxin types are unrelated in sequence and three-dimensional structure, cloning and comparative analysis of their loci revealed a highly similar sequence at the 5' region, which encodes a signal peptide. This similarity was likely generated by gene fusion and could be advantageous in transcript stability and intracellular trafficking and secretion. In addition, these analyses identified the processed pseudogenes of the two gene families in the genome of A. viridis, probably resulting from retrotransposition events. As presence of processed pseudogenes in the genome requires transcription in germ-line cells, we analyzed oocyte-rich ovaries and found that indeed they contain Types I and III transcripts. This result raises questions regarding the role of toxin transcripts in these tissues. Overall, the retrotransposition and gene fusion events suggest that the genes of both Types I and III neurotoxins evolved in a similar fashion and share a partial common ancestry.

  10. A taxonomic review of the Dark-winged Trumpeter Psophia viridis (Aves: Gruiformes: Psophiidae

    Directory of Open Access Journals (Sweden)

    Marina Oppenheimer

    2009-01-01

    Full Text Available The Dark-winged Trumpeter, Psophia viridis (Gruiformes, Psophiidae is a Brazilian endemic species and includes three subspecies: Psophia viridis viridis Spix, 1825; Psophia v. dextralis Conover, 1934, and Psophia v. obscura Pelzeln, 1857, as well as P. v. interjecta Griscom & Greenway, 1937, whose validity has been questioned by several authors. These taxa are allopatric in distribution along the south of the Amazon River, although the precise limits of their distribution still remain unknown. This complex has never been taxonomically reviewed and this work aims to test the validity of its taxa based on the Phylogenetic Species Concept. Morphometrical characters and plumage colour patterns were analyzed, and the distribution of the taxa was also revised. In this study, 108 specimens from 41 localities were examined (all types included, with each reliable literature-based locality being included in order to delimit the geographical distribution of the complex. Morphometrical data did not point out significant differences between the taxa, also showing no sexual dimorphism among them. Meanwhile, plumage characters showed consistent and distinct patterns for each of the taxa, except for P. v. interjecta, whose features indicated by authors as diagnosable are the result of individual variation. No clinal variation or intergradation were observed, even at regions close to the rivers headwaters, where supposedly populations could be in contact. It is suggested that the currently accepted subspecies be elevated to the species level, such as: Psophia viridis Spix, 1825, distributed in the Madeira-Tapajós interfluvium, P. dextralis, found in the Tapajós-Tocantins interfluvium, and P. obscura, which occurs from the right bank of the Tocantins River to the west of the State of Maranhão.Os jacamins-de-costas-verdes, Psophia viridis (Gruiformes, Psophiidae são endêmicos da Amazônia brasileira e contam, atualmente, com três subespécies reconhecidas

  11. Acquired phototrophy through retention of functional chloroplasts increases growth efficiency of the sea slug Elysia viridis.

    Directory of Open Access Journals (Sweden)

    Finn A Baumgartner

    Full Text Available Photosynthesis is a fundamental process sustaining heterotrophic organisms at all trophic levels. Some mixotrophs can retain functional chloroplasts from food (kleptoplasty, and it is hypothesized that carbon acquired through kleptoplasty may enhance trophic energy transfer through increased host growth efficiency. Sacoglossan sea slugs are the only known metazoans capable of kleptoplasty, but the relative fitness contributions of heterotrophy through grazing, and phototrophy via kleptoplasts, are not well understood. Fitness benefits (i.e. increased survival or growth of kleptoplasty in sacoglossans are commonly studied in ecologically unrealistic conditions under extended periods of complete darkness and/or starvation. We compared the growth efficiency of the sacoglossan Elysia viridis with access to algal diets providing kleptoplasts of differing functionality under ecologically relevant light conditions. Individuals fed Codium fragile, which provide highly functional kleptoplasts, nearly doubled their growth efficiency under high compared to low light. In contrast, individuals fed Cladophora rupestris, which provided kleptoplasts of limited functionality, showed no difference in growth efficiency between light treatments. Slugs feeding on Codium, but not on Cladophora, showed higher relative electron transport rates (rETR in high compared to low light. Furthermore, there were no differences in the consumption rates of the slugs between different light treatments, and only small differences in nutritional traits of algal diets, indicating that the increased growth efficiency of E. viridis feeding on Codium was due to retention of functional kleptoplasts. Our results show that functional kleptoplasts from Codium can provide sacoglossan sea slugs with fitness advantages through photosynthesis.

  12. Prevalence of airborne allergenic Amaranthus viridis pollen in seven different regions of Saudi Arabia

    International Nuclear Information System (INIS)

    Hasnain, Syed M.; Fatima, K.; Al-Frayh, A.

    2007-01-01

    Amaranthus pollen grains are known to have highly allergenic and potential cause of respiratory allergic diseases. Nevertheless, data on the prevalence of Amaranthus pollen in the environment is limited and almost non-existent for Saudi Arabia. We conducted an investigation to record the airborne incidence of A.viridis and other allergenic pollen in Al-Khobar, Dammam, Hail, Jeddah, Jizan, Qassim and Taif, using Burkard Volumetric Samplers. The samples were operated continuously for one year at each location. The data revealed A.viridis as one of the major components of outdoor airspora, constituting a maximum of 96% of total pollen counts in Hail, followed by Al-Khobar (89%), Jeddah (87%), Qassim (85%), Taif (84%), Dammam (83%) and Jizan (61%). These higher percentages contributed largely to the total weed pollen catch during August to November in all seven regions. In addition, the data also showed that A. virdis pollen were present throughout the year with distinct seasonal variations. The diel periodicities for at least five sites averaged over a year showed mid-day to early evening maxima. The maximum concentration approached 3000 mt. cube of air in October and 1827 mt. cube of air in September. The data also exhibited, a seasonal pattern, in their maximum appearance. Further studies related to biochemical and allergological aspects are needed to confirm the allergenic impact of Amaranthus pollen and sensitization in allergic individuals in the Kingdom of Saudi Arabia. (author)

  13. Comparative venomics of the Prairie Rattlesnake (Crotalus viridis viridis) from Colorado: Identification of a novel pattern of ontogenetic changes in venom composition and assessment of the immunoreactivity of the commercial antivenom CroFab®.

    Science.gov (United States)

    Saviola, Anthony J; Pla, Davinia; Sanz, Libia; Castoe, Todd A; Calvete, Juan J; Mackessy, Stephen P

    2015-05-21

    Here we describe and compare the venomic and antivenomic characteristics of both neonate and adult Prairie Rattlesnake (Crotalus viridis viridis) venoms. Although both neonate and adult venoms contain unique components, similarities among protein family content were seen. Both neonate and adult venoms consisted of myotoxin, bradykinin-potentiating peptide (BPP), phospholipase A2 (PLA2), Zn(2+)-dependent metalloproteinase (SVMP), serine proteinase, L-amino acid oxidase (LAAO), cysteine-rich secretory protein (CRISP) and disintegrin families. Quantitative differences, however, were observed, with venoms of adults containing significantly higher concentrations of the non-enzymatic toxic compounds and venoms of neonates containing higher concentrations of pre-digestive enzymatic proteins such as SVMPs. To assess the relevance of this venom variation in the context of snakebite and snakebite treatment, we tested the efficacy of the common antivenom CroFab® for recognition of both adult and neonate venoms in vitro. This comparison revealed that many of the major protein families (SVMPs, CRISP, PLA2, serine proteases, and LAAO) in both neonate and adult venoms were immunodepleted by the antivenom, whereas myotoxins, one of the major toxic components of C. v. viridis venom, in addition to many of the small peptides, were not efficiently depleted by CroFab®. These results therefore provide a comprehensive catalog of the venom compounds present in C. v. viridis venom and new molecular insight into the potential efficacy of CroFab® against human envenomations by one of the most widely distributed rattlesnake species in North America. Comparative proteomic analysis of venoms of neonate and adult Prairie Rattlesnake (Crotalus viridis viridis) from a discrete population in Colorado revealed a novel pattern of ontogenetic shifts in toxin composition for viperid snakes. The observed stage-dependent decrease of the relative content of disintegrins, catalytically active D49-PLA2s

  14. Changes in microbial communities associated with the sea anemone Anemonia viridis in a natural pH gradient.

    Science.gov (United States)

    Meron, Dalit; Buia, Maria-Cristina; Fine, Maoz; Banin, Ehud

    2013-02-01

    Ocean acidification, resulting from rising atmospheric carbon dioxide concentrations, is a pervasive stressor that can affect many marine organisms and their symbionts. Studies which examine the host physiology and microbial communities have shown a variety of responses to the ocean acidification process. Recently, several studies were conducted based on field experiments, which take place in natural CO(2) vents, exposing the host to natural environmental conditions of varying pH. This study examines the sea anemone Anemonia viridis which is found naturally along the pH gradient in Ischia, Italy, with an aim to characterize whether exposure to pH impacts the holobiont. The physiological parameters of A. viridis (Symbiodinium density, protein, and chlorophyll a+c concentration) and its microbial community were monitored. Although reduction in pH was seen to have had an impact on composition and diversity of associated microbial communities, no significant changes were observed in A. viridis physiology, and no microbial stress indicators (i.e., pathogens, antibacterial activity, etc.) were detected. In light of these results, it appears that elevated CO(2) does not have a negative influence on A. viridis that live naturally in the site. This suggests that natural long-term exposure and dynamic diverse microbial communities may contribute to the acclimation process of the host in a changing pH environment.

  15. Natural high pCO2 increases autotrophy in Anemonia viridis (Anthozoa) as revealed from stable isotope (C, N) analysis.

    Science.gov (United States)

    Horwitz, Rael; Borell, Esther M; Yam, Ruth; Shemesh, Aldo; Fine, Maoz

    2015-03-05

    Contemporary cnidarian-algae symbioses are challenged by increasing CO2 concentrations (ocean warming and acidification) affecting organisms' biological performance. We examined the natural variability of carbon and nitrogen isotopes in the symbiotic sea anemone Anemonia viridis to investigate dietary shifts (autotrophy/heterotrophy) along a natural pCO2 gradient at the island of Vulcano, Italy. δ(13)C values for both algal symbionts (Symbiodinium) and host tissue of A. viridis became significantly lighter with increasing seawater pCO2. Together with a decrease in the difference between δ(13)C values of both fractions at the higher pCO2 sites, these results indicate there is a greater net autotrophic input to the A. viridis carbon budget under high pCO2 conditions. δ(15)N values and C/N ratios did not change in Symbiodinium and host tissue along the pCO2 gradient. Additional physiological parameters revealed anemone protein and Symbiodinium chlorophyll a remained unaltered among sites. Symbiodinium density was similar among sites yet their mitotic index increased in anemones under elevated pCO2. Overall, our findings show that A. viridis is characterized by a higher autotrophic/heterotrophic ratio as pCO2 increases. The unique trophic flexibility of this species may give it a competitive advantage and enable its potential acclimation and ecological success in the future under increased ocean acidification.

  16. Cultivation of green mussel, Perna viridis L., on a floating raft in an estuary along the west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Rivonker, C.U.; Ansari, Z.A.; Parulekar, A.H.

    Total production of green mussels, Perna viridis, grown on a raft (16 m sup(2)) for 1 year was 2144.64 kg and biomass (meat weight) was 1040.00 kg. Annual production (P) and biomass (B) estimated were 33.51 and 16.25 kg m sup(-1) respectively...

  17. Whole transcriptome analysis using next-generation sequencing of model species Setaria viridis to support C4 photosynthesis research.

    Science.gov (United States)

    Xu, Jiajia; Li, Yuanyuan; Ma, Xiuling; Ding, Jianfeng; Wang, Kai; Wang, Sisi; Tian, Ye; Zhang, Hui; Zhu, Xin-Guang

    2013-09-01

    Setaria viridis is an emerging model species for genetic studies of C4 photosynthesis. Many basic molecular resources need to be developed to support for this species. In this paper, we performed a comprehensive transcriptome analysis from multiple developmental stages and tissues of S. viridis using next-generation sequencing technologies. Sequencing of the transcriptome from multiple tissues across three developmental stages (seed germination, vegetative growth, and reproduction) yielded a total of 71 million single end 100 bp long reads. Reference-based assembly using Setaria italica genome as a reference generated 42,754 transcripts. De novo assembly generated 60,751 transcripts. In addition, 9,576 and 7,056 potential simple sequence repeats (SSRs) covering S. viridis genome were identified when using the reference based assembled transcripts and the de novo assembled transcripts, respectively. This identified transcripts and SSR provided by this study can be used for both reverse and forward genetic studies based on S. viridis.

  18. Elucidating the Small Regulatory RNA Repertoire of the Sea Anemone Anemonia viridis Based on Whole Genome and Small RNA Sequencing.

    Science.gov (United States)

    Urbarova, Ilona; Patel, Hardip; Forêt, Sylvain; Karlsen, Bård Ove; Jørgensen, Tor Erik; Hall-Spencer, Jason M; Johansen, Steinar D

    2018-02-01

    Cnidarians harbor a variety of small regulatory RNAs that include microRNAs (miRNAs) and PIWI-interacting RNAs (piRNAs), but detailed information is limited. Here, we report the identification and expression of novel miRNAs and putative piRNAs, as well as their genomic loci, in the symbiotic sea anemone Anemonia viridis. We generated a draft assembly of the A. viridis genome with putative size of 313 Mb that appeared to be composed of about 36% repeats, including known transposable elements. We detected approximately equal fractions of DNA transposons and retrotransposons. Deep sequencing of small RNA libraries constructed from A. viridis adults sampled at a natural CO2 gradient off Vulcano Island, Italy, identified 70 distinct miRNAs. Eight were homologous to previously reported miRNAs in cnidarians, whereas 62 appeared novel. Nine miRNAs were recognized as differentially expressed along the natural seawater pH gradient. We found a highly abundant and diverse population of piRNAs, with a substantial fraction showing ping-pong signatures. We identified nearly 22% putative piRNAs potentially targeting transposable elements within the A. viridis genome. The A. viridis genome appeared similar in size to that of other hexacorals with a very high divergence of transposable elements resembling that of the sea anemone genus Exaiptasia. The genome encodes and expresses a high number of small regulatory RNAs, which include novel miRNAs and piRNAs. Differentially expressed small RNAs along the seawater pH gradient indicated regulatory gene responses to environmental stressors. © The Author(s) 2018. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  19. Trace element profiles of the sea anemone Anemonia viridis living nearby a natural CO2 vent

    Directory of Open Access Journals (Sweden)

    Rael Horwitz

    2014-09-01

    Full Text Available Ocean acidification (OA is not an isolated threat, but acts in concert with other impacts on ecosystems and species. Coastal marine invertebrates will have to face the synergistic interactions of OA with other global and local stressors. One local factor, common in coastal environments, is trace element contamination. CO2 vent sites are extensively studied in the context of OA and are often considered analogous to the oceans in the next few decades. The CO2 vent found at Levante Bay (Vulcano, NE Sicily, Italy also releases high concentrations of trace elements to its surrounding seawater, and is therefore a unique site to examine the effects of long-term exposure of nearby organisms to high pCO2 and trace element enrichment in situ. The sea anemone Anemonia viridis is prevalent next to the Vulcano vent and does not show signs of trace element poisoning/stress. The aim of our study was to compare A. viridis trace element profiles and compartmentalization between high pCO2 and control environments. Rather than examining whole anemone tissue, we analyzed two different body compartments—the pedal disc and the tentacles, and also examined the distribution of trace elements in the tentacles between the animal and the symbiotic algae. We found dramatic changes in trace element tissue concentrations between the high pCO2/high trace element and control sites, with strong accumulation of iron, lead, copper and cobalt, but decreased concentrations of cadmium, zinc and arsenic proximate to the vent. The pedal disc contained substantially more trace elements than the anemone’s tentacles, suggesting the pedal disc may serve as a detoxification/storage site for excess trace elements. Within the tentacles, the various trace elements displayed different partitioning patterns between animal tissue and algal symbionts. At both sites iron was found primarily in the algae, whereas cadmium, zinc and arsenic were primarily found in the animal tissue. Our data

  20. Trace element profiles of the sea anemone Anemonia viridis living nearby a natural CO2 vent.

    Science.gov (United States)

    Horwitz, Rael; Borell, Esther M; Fine, Maoz; Shaked, Yeala

    2014-01-01

    Ocean acidification (OA) is not an isolated threat, but acts in concert with other impacts on ecosystems and species. Coastal marine invertebrates will have to face the synergistic interactions of OA with other global and local stressors. One local factor, common in coastal environments, is trace element contamination. CO2 vent sites are extensively studied in the context of OA and are often considered analogous to the oceans in the next few decades. The CO2 vent found at Levante Bay (Vulcano, NE Sicily, Italy) also releases high concentrations of trace elements to its surrounding seawater, and is therefore a unique site to examine the effects of long-term exposure of nearby organisms to high pCO2 and trace element enrichment in situ. The sea anemone Anemonia viridis is prevalent next to the Vulcano vent and does not show signs of trace element poisoning/stress. The aim of our study was to compare A. viridis trace element profiles and compartmentalization between high pCO2 and control environments. Rather than examining whole anemone tissue, we analyzed two different body compartments-the pedal disc and the tentacles, and also examined the distribution of trace elements in the tentacles between the animal and the symbiotic algae. We found dramatic changes in trace element tissue concentrations between the high pCO2/high trace element and control sites, with strong accumulation of iron, lead, copper and cobalt, but decreased concentrations of cadmium, zinc and arsenic proximate to the vent. The pedal disc contained substantially more trace elements than the anemone's tentacles, suggesting the pedal disc may serve as a detoxification/storage site for excess trace elements. Within the tentacles, the various trace elements displayed different partitioning patterns between animal tissue and algal symbionts. At both sites iron was found primarily in the algae, whereas cadmium, zinc and arsenic were primarily found in the animal tissue. Our data suggests that A. viridis

  1. Transient grating spectroscopy in photosynthetic purple bacteria Rhodobacter sphaeroides 2.4.1

    Energy Technology Data Exchange (ETDEWEB)

    Sugisaki, Mitsuru, E-mail: mitsuru@sci.osaka-cu.ac.j [CREST-JST and Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi, Osaka 558-8585 (Japan); Fujiwara, Masazumi; Fujii, Ritsuko [CREST-JST and Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi, Osaka 558-8585 (Japan); Nakagawa, Katsunori; Nango, Mamoru [CREST-JST and Graduate School of Engineering, Nagoya Institute of Technology, Gokiso, Showa, Nagoya 466-8555 (Japan); Cogdell, Richard J. [Glasgow Biomedical Research Centre, IBLS, University of Glasgow, 126 University Place, Glasgow G12 8TA, Scotland (United Kingdom); Hashimoto, Hideki [CREST-JST and Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi, Osaka 558-8585 (Japan)

    2009-12-15

    The vibronic coherence of photosynthetic pigment-protein complexes has been investigated by means of transient grating spectroscopy using sub 20 fs optical pulses. In the present work, we focus our attention on the LH2 antenna complexes from Rhodobacter sphaeroides 2.4.1 because the information about their structure investigated by the electron and atomic force microscopy is available and the electric levels of pigments are well resolved, resulting in clear absorption spectrum. The vibronic coherent oscillations with a period of a few tens of femtoseconds have been clearly observed. We found that the temporal change of the coherent oscillations reflects the vibrational relaxation in the ground state. Calculations based on the Brownian oscillator model were performed under the impulsive excitation limit. The spectral density has been determined from the Raman measurement of spheroidene. Good agreement between the calculation and the experimental results has been achieved in the linear absorption spectrum and transient grating signal, which strongly supports the validity of our model.

  2. Potential use of thermophilic dark fermentation effluents in photofermentative hydrogen production by Rhodobacter capsulatus

    Energy Technology Data Exchange (ETDEWEB)

    Ozgura, E.; Afsar, N.; Eroglu, I. [Middle East Technical University, Department of Chemical Engineering, 06531 Ankara (Turkey); De Vrije, T.; Claassen, P.A.M. [Wageningen UR, Agrotechnology and Food Sciences Group, Wageningen UR, P.O. Box 17, 6700 AA Wageningen (Netherlands); Yucel, M.; Gunduz, U. [Middle East Technical University, Department of Biology, 06531 Ankara (Turkey)

    2010-12-15

    Biological hydrogen production by a sequential operation of dark and photofermentation is a promising route to produce hydrogen. The possibility of using renewable resources, like biomass and agro-industrial wastes, provides a dual effect of sustainability in biohydrogen production and simultaneous waste removal. In this study, photofermentative hydrogen production on effluents of thermophilic dark fermentations on glucose, potato steam peels (PSP) hydrolysate and molasses was investigated in indoor, batch operated bioreactors. An extreme thermophile Caldicellulosiruptor saccharolyticus was used in the dark fermentation step, and Rhodobacter capsulatus (DSM1710) was used in the photofermentation step. Addition of buffer, Fe and Mo to dark fermentor effluents (DFEs) improved the overall efficiency of hydrogen production. The initial acetate concentration in the DFE needed to be adjusted to 30-40 mM by dilution to increase the yield of hydrogen in batch light-supported fermentations. The thermophilic DFEs are suitable for photofermentative hydrogen production, provided that they are supplemented with buffer and nutrients. The overall hydrogen yield of the two-step fermentations was higher than the yield of single step dark fermentations.

  3. Phytoavailability and geospeciation of cadmium in contaminated soil remediated by Rhodobacter sphaeroides.

    Science.gov (United States)

    Fan, Wenhong; Jia, Yingying; Li, Xiaomin; Jiang, Wei; Lu, Lin

    2012-07-01

    A microorganism was isolated from oil field injection water and identified as Rhodobacter sphaeroides. It was used for the remediation of simulated cadmium-contaminated soil. The phytoavailability of Cd was investigated through wheat seedling method to determine the efficiency of remediation. It was found that after remediation, the accumulation of Cd in wheat roots and leaves decreased by 67% and 53%, respectively. The Cd speciation in soil was determined with Tessier extraction procedure. It was found that the total Cd content in soil did not change during the experiments, but the geo-speciation of Cd changed remarkably. Among the five fractions, the concentration of exchangeable phases decreased by 27-46% and that of the phases bound to Fe-Mn oxides increased by 22-44%. The decrease of Cd accumulation in wheat showed significant positive correlation with the decrease of exchangeable phases. It could be concluded that the remediation of R. sphaeroides was carried out through the conversion of Cd to more stable forms. The decrease of sulfate concentration in supernatant indicated that the R. sphaeroides consumed sulfate. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Early bacteriopheophytin reduction in charge separation in reaction centers of Rhodobacter sphaeroides.

    Science.gov (United States)

    Zhu, Jingyi; van Stokkum, Ivo H M; Paparelli, Laura; Jones, Michael R; Groot, Marie Louise

    2013-06-04

    A question at the forefront of biophysical sciences is, to what extent do quantum effects and protein conformational changes play a role in processes such as biological sensing and energy conversion? At the heart of photosynthetic energy transduction lie processes involving ultrafast energy and electron transfers among a small number of tetrapyrrole pigments embedded in the interior of a protein. In the purple bacterial reaction center (RC), a highly efficient ultrafast charge separation takes place between a pair of bacteriochlorophylls: an accessory bacteriochlorophyll (B) and bacteriopheophytin (H). In this work, we applied ultrafast spectroscopy in the visible and near-infrared spectral region to Rhodobacter sphaeroides RCs to accurately track the timing of the electron on BA and HA via the appearance of the BA and HA anion bands. We observed an unexpectedly early rise of the HA⁻ band that challenges the accepted simple picture of stepwise electron transfer with 3 ps and 1 ps time constants. The implications for the mechanism of initial charge separation in bacterial RCs are discussed in terms of a possible adiabatic electron transfer step between BA and HA, and the effect of protein conformation on the electron transfer rate. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  5. A cryptochrome-like protein is involved in the regulation of photosynthesis genes in Rhodobacter sphaeroides.

    Science.gov (United States)

    Hendrischk, Anne-Kathrin; Frühwirth, Sebastian Walter; Moldt, Julia; Pokorny, Richard; Metz, Sebastian; Kaiser, Gebhard; Jäger, Andreas; Batschauer, Alfred; Klug, Gabriele

    2009-11-01

    Blue light receptors belonging to the cryptochrome/photolyase family are found in all kingdoms of life. The functions of photolyases in repair of UV-damaged DNA as well as of cryptochromes in the light-dependent regulation of photomorphogenetic processes and in the circadian clock in plants and animals are well analysed. In prokaryotes, the only role of members of this protein family that could be demonstrated is DNA repair. Recently, we identified a gene for a cryptochrome-like protein (CryB) in the alpha-proteobacterium Rhodobacter sphaeroides. The protein lacks the typical C-terminal extension of cryptochromes, and is not related to the Cry DASH family. Here we demonstrate that CryB binds flavin adenine dinucleotide that can be photoreduced by blue light. CryB binds single-stranded DNA with very high affinity (K(d) approximately 10(-8) M) but double-stranded DNA and single-stranded RNA with far lower affinity (K(d) approximately 10(-6) M). Despite of that, no in vitro repair activity for pyrimidine dimers in single-stranded DNA could be detected. However, we show that CryB clearly affects the expression of genes for pigment-binding proteins and consequently the amount of photosynthetic complexes in R. sphaeroides. Thus, for the first time a role of a bacterial cryptochrome in gene regulation together with a biological function is demonstrated.

  6. Role of the Irr protein in the regulation of iron metabolism in Rhodobacter sphaeroides.

    Directory of Open Access Journals (Sweden)

    Verena Peuser

    Full Text Available In Rhizobia the Irr protein is an important regulator for iron-dependent gene expression. We studied the role of the Irr homolog RSP_3179 in the photosynthetic alpha-proteobacterium Rhodobacter sphaeroides. While Irr had little effect on growth under iron-limiting or non-limiting conditions its deletion resulted in increased resistance to hydrogen peroxide and singlet oxygen. This correlates with an elevated expression of katE for catalase in the Irr mutant compared to the wild type under non-stress conditions. Transcriptome studies revealed that Irr affects the expression of genes for iron metabolism, but also has some influence on genes involved in stress response, citric acid cycle, oxidative phosphorylation, transport, and photosynthesis. Most genes showed higher expression levels in the wild type than in the mutant under normal growth conditions indicating an activator function of Irr. Irr was however not required to activate genes of the iron metabolism in response to iron limitation, which showed even stronger induction in the absence of Irr. This was also true for genes mbfA and ccpA, which were verified as direct targets for Irr. Our results suggest that in R. sphaeroides Irr diminishes the strong induction of genes for iron metabolism under iron starvation.

  7. Improving the hydrogen production capacity of Rhodobacter capsulatus by genetically modifying redox balancing pathways

    Energy Technology Data Exchange (ETDEWEB)

    Oeztuerk, Yavuz [TUEBITAK Research Institute for Genetic Engineering and Biotechnology, Gebze Kocaeli (Turkey); Goekce, Abdulmecit [Istanbul Technical Univ. (Turkey). Dept. of Molecular Biology and Genetics; Guergan, Muazzez; Yuecel, Meral [Middle East Technical Univ., Ankara (Turkey). Dept. of Biology

    2010-07-01

    In Rhodobacter capsulatus, balancing the oxidation-reduction potential (redox-balance) is maintained via a number of inter-dependent regulatory mechanisms that enable these organisms to accommodate divergent growth modes. In order to maintain redox homeostasis, this bacterium possesses regulatory mechanisms functioning as electron sinks affecting the oxidation-reduction state of the ubiquinone pool. Under the photoheterotrophic growth conditions with reduced carbon sources, the excess reducing equivalents are primarily consumed via the reduction of CO{sub 2} through the Calvin-Benson-Bassham (CBB) pathway or by the reduction of protons into hydrogen with the use of dinitrogenase enzyme system. In this study, our aim was to develop strategies to funnel the excess reducing equivalents to nitrogenase-dependent hydrogen production by blocking the carbon-fixation pathway. To realize this purpose, CO{sub 2} fixation was blocked by inactivating the Phosphoribulokinase (PRK) of CBB pathway in wild type (MT1131), uptake-hydrogenase (YO3) and cyt cbb{sub 3} oxidase deficient (YO4) strains. The hydrogen production capacity of newly generated strains deficient in the Calvin-Benson-Bassham pathway were analyzed and compared with wild type strains. The results indicated that, the hydrogen production efficiency and capacity of R. capsulatus was further improved by directing the excess reducing equivalents to dinitrogenase-dependent hydrogen production. (orig.)

  8. Crystallization of a flavodoxin involved in nitrogen fixation in Rhodobacter capsulatus

    Energy Technology Data Exchange (ETDEWEB)

    Pérez-Dorado, Inmaculada [Grupo de Cristalografía Macromolecular y Biología Estructural, Instituto de Química-Física Rocasolano, CSIC, Serrano 119, 28006 Madrid (Spain); Bortolotti, Ana; Cortez, Néstor [Instituto de Biología Molecular y Celular de Rosario (Universidad Nacional de Rosario y CONICET), Suipacha 531, S2002LRK Rosario (Argentina); Hermoso, Juan A., E-mail: xjuan@iqfr.csic.es [Grupo de Cristalografía Macromolecular y Biología Estructural, Instituto de Química-Física Rocasolano, CSIC, Serrano 119, 28006 Madrid (Spain)

    2008-05-01

    The flavodoxin NifF from R. capsulatus, a candidate for nitrogenase reduction during nitrogen fixation, has been crystallized using the hanging-drop vapour-diffusion method. Preliminary X-ray data processing at 2.17 Å resolution allowed determination of the crystal system and unit-cell parameters. Flavodoxins are small electron-transfer proteins that contain one molecule of noncovalently bound flavin mononucleotide (FMN). The flavodoxin NifF from the photosynthetic bacterium Rhodobacter capsulatus is reduced by one electron from ferredoxin/flavodoxin:NADP(H) reductase and was postulated to be an electron donor to nitrogenase in vivo. NifF was cloned and overexpressed in Escherichia coli, purified and concentrated for crystallization using the hanging-drop vapour-diffusion method at 291 K. Crystals grew from a mixture of PEG 3350 and PEG 400 at pH 5.5 and belong to the tetragonal space group P4{sub 1}2{sub 1}2, with unit-cell parameters a = b = 66.49, c = 121.32 Å. X-ray data sets have been collected to 2.17 Å resolution.

  9. A novel nitrilase from Rhodobacter sphaeroides LHS-305: cloning, heterologous expression and biochemical characterization.

    Science.gov (United States)

    Wang, Hualei; Li, Guinan; Li, Mingyang; Wei, Dongzhi; Wang, Xuedong

    2014-01-01

    In this study, a novel nitrilase gene from Rhodobacter sphaeroides was cloned and overexpressed in Escherichia coli. The open reading frame of the nitrilase gene includes 969 base pairs, which encodes a putative polypeptide of 322 amino acid residues. The molecular weight of the purified native nitrilase was about 560 kDa determined by size exclusion chromatography. This nitrilase showed one single band on SDS-PAGE with a molecular weight of 40 kDa. This suggested that the native nitrilase consisted of 14 subunits with identical size. The optimal pH and temperature of the purified enzyme were 7.0 and 40 °C, respectively. The kinetic parameters V max and K m toward 3-cyanopyridine were 77.5 μmol min(-1) mg(-1) and 73.1 mmol/l, respectively. The enzyme can easily convert aliphatic nitrile and aromatic nitriles to their corresponding acids. Furthermore, this enzyme demonstrated regioselectivity in hydrolysis of aliphatic dinitriles. This specific characteristic makes this nitrilase have a great potential for commercial production of various cyanocarboxylic acids by hydrolyzing readily available dinitriles.

  10. A new nitrilase-producing strain named Rhodobacter sphaeroides LHS-305: biocatalytic characterization and substrate specificity.

    Science.gov (United States)

    Yang, Chunsheng; Wang, Xuedong; Wei, Dongzhi

    2011-12-01

    The characteristics of the new nitrilase-producing strain Rhodobacter sphaeroides LHS-305 were investigated. By investigating several parameters influencing nitrilase production, the specific cell activity was ultimately increased from 24.5 to 75.0 μmol g(-1) min(-1), and hereinto, the choice of inducer proved the most important factor. The aromatic nitriles (such as 3-cyanopyridine and benzonitrile) were found to be the most favorable substrates of the nitrilase by analyzing the substrate spectrum. It was speculated that the unsaturated carbon atom attached to the cyano group was crucial for this type of nitrilase. The value of apparent K (m), substrate inhibition constant, and product inhibition constant of the nitrilase against 3-cyanopyridine were 4.5 × 10(-2), 29.2, and 8.6 × 10(-3) mol L(-1), respectively. When applied in nicotinic acid preparation, the nitrilase is able to hydrolyze 200 mmol L(-1) 3-cyanopyridine with 93% conversion rate in 13 h by 6.1 g L(-1) cells (dry cell weight).

  11. Photodynamics of the small BLUF protein BlrB from Rhodobacter sphaeroides.

    Science.gov (United States)

    Zirak, P; Penzkofer, A; Schiereis, T; Hegemann, P; Jung, A; Schlichting, I

    2006-06-01

    The BLUF protein BlrB from the non-sulphur anoxyphototrophic purple bacterium Rhodobacter sphaeroides is characterized by absorption and emission spectroscopy. BlrB expressed from E. coli binding FAD, FMN, and riboflavin (called BrlB(I)) and recombinant BlrB containing only FAD (called BlrB(II)) are investigated. The dark-adapted proteins exist in two different receptor conformations (receptor states) with different sub-nanosecond fluorescence lifetimes (BLUF(r,f) and BLUF(r,sl)). Some of the flavin-cofactor (ca. 8%) is unbound in thermodynamic equilibrium with the bound cofactor. The two receptor conformations are transformed to putative signalling states (BLUF(s,f) and BLUF(s,sl)) of decreased fluorescence efficiency and shortened fluorescence lifetime by blue-light excitation. In the dark at room temperature both signalling states recover back to the initial receptor states with a time constant of about 2s. Quantum yields of signalling state formation of about 90% for BlrB(II) and about 40% for BlrB(I) were determined by intensity dependent transmission measurements. Extended blue-light excitation causes unbound flavin degradation (formation of lumichrome and lumiflavin-derivatives) and bound cofactor conversion to the semiquinone form. The flavin-semiquinone further reduces and the reduced flavin re-oxidizes back in the dark. A photo-dynamics scheme is presented and relevant quantum efficiencies and time constants are determined.

  12. Absorption and fluorescence spectroscopic characterization of BLUF domain of AppA from Rhodobacter sphaeroides

    Energy Technology Data Exchange (ETDEWEB)

    Zirak, P. [Institut II - Experimentelle und Angewandte Physik, Universitaet Regensburg, Universitaetstrasse 31, D-93053 Regensburg (Germany); Penzkofer, A. [Institut II - Experimentelle und Angewandte Physik, Universitaet Regensburg, Universitaetstrasse 31, D-93053 Regensburg (Germany)], E-mail: alfons.penzkofer@physik.uni-regensburg.de; Schiereis, T. [Institut fuer Biologie, Experimentelle Biophysik, Humboldt-Universitaet zu Berlin, Invalidenstrasse 42, D-10115 Berlin (Germany); Hegemann, P. [Institut fuer Biologie, Experimentelle Biophysik, Humboldt-Universitaet zu Berlin, Invalidenstrasse 42, D-10115 Berlin (Germany); Jung, A. [Max-Planck-Institut fuer medizinische Forschung, Abteilung Biomolekulare Mechanismen, Jahnstrasse 29, D-69120 Heidelberg (Germany); Schlichting, I. [Max-Planck-Institut fuer medizinische Forschung, Abteilung Biomolekulare Mechanismen, Jahnstrasse 29, D-69120 Heidelberg (Germany)

    2005-08-08

    The BLUF domain of the transcriptional anti-repressor protein AppA from the non-sulfur anoxyphototrophic purple bacterium Rhodobacter sphaeroides was characterized by absorption and emission spectroscopy. The BLUF domain constructs AppA{sub 148} (consisting of amino-acid residues 1-148) and AppA{sub 126} (amino-acid residues 1-126) are investigated. The cofactor of the investigated domains is found to consist of a mixture of the flavins riboflavin, FMN, and FAD. The dark-adapted domains exist in two different active receptor conformations (receptor states) with different sub-nanosecond fluorescence lifetimes (BLUF{sub r,f} and BLUF{sub r,sl}) and a small non-interacting conformation (BLUF{sub nc}). The active receptor conformations are transformed to putative signalling states (BLUF{sub s,f} and BLUF{sub s,sl}) of low fluorescence efficiency and picosecond fluorescence lifetime by blue-light excitation (light-adapted domains). In the dark at room temperature both signalling states recover back to the initial receptor states with a time constant of about 17 min. A quantum yield of signalling state formation of about 25% was determined by intensity dependent transmission measurements. A photo-cycle scheme is presented including photo-induced charge transfer complex formation, charge recombination, and protein binding pocket reorganisation.

  13. Absorption and fluorescence spectroscopic characterization of BLUF domain of AppA from Rhodobacter sphaeroides

    Science.gov (United States)

    Zirak, P.; Penzkofer, A.; Schiereis, T.; Hegemann, P.; Jung, A.; Schlichting, I.

    2005-08-01

    The BLUF domain of the transcriptional anti-repressor protein AppA from the non-sulfur anoxyphototrophic purple bacterium Rhodobacter sphaeroides was characterized by absorption and emission spectroscopy. The BLUF domain constructs AppA 148 (consisting of amino-acid residues 1-148) and AppA 126 (amino-acid residues 1-126) are investigated. The cofactor of the investigated domains is found to consist of a mixture of the flavins riboflavin, FMN, and FAD. The dark-adapted domains exist in two different active receptor conformations (receptor states) with different sub-nanosecond fluorescence lifetimes (BLUF r,f and BLUF r,sl) and a small non-interacting conformation (BLUF nc). The active receptor conformations are transformed to putative signalling states (BLUF s,f and BLUF s,sl) of low fluorescence efficiency and picosecond fluorescence lifetime by blue-light excitation (light-adapted domains). In the dark at room temperature both signalling states recover back to the initial receptor states with a time constant of about 17 min. A quantum yield of signalling state formation of about 25% was determined by intensity dependent transmission measurements. A photo-cycle scheme is presented including photo-induced charge transfer complex formation, charge recombination, and protein binding pocket reorganisation.

  14. Absorption and fluorescence spectroscopic characterization of BLUF domain of AppA from Rhodobacter sphaeroides

    International Nuclear Information System (INIS)

    Zirak, P.; Penzkofer, A.; Schiereis, T.; Hegemann, P.; Jung, A.; Schlichting, I.

    2005-01-01

    The BLUF domain of the transcriptional anti-repressor protein AppA from the non-sulfur anoxyphototrophic purple bacterium Rhodobacter sphaeroides was characterized by absorption and emission spectroscopy. The BLUF domain constructs AppA 148 (consisting of amino-acid residues 1-148) and AppA 126 (amino-acid residues 1-126) are investigated. The cofactor of the investigated domains is found to consist of a mixture of the flavins riboflavin, FMN, and FAD. The dark-adapted domains exist in two different active receptor conformations (receptor states) with different sub-nanosecond fluorescence lifetimes (BLUF r,f and BLUF r,sl ) and a small non-interacting conformation (BLUF nc ). The active receptor conformations are transformed to putative signalling states (BLUF s,f and BLUF s,sl ) of low fluorescence efficiency and picosecond fluorescence lifetime by blue-light excitation (light-adapted domains). In the dark at room temperature both signalling states recover back to the initial receptor states with a time constant of about 17 min. A quantum yield of signalling state formation of about 25% was determined by intensity dependent transmission measurements. A photo-cycle scheme is presented including photo-induced charge transfer complex formation, charge recombination, and protein binding pocket reorganisation

  15. Bioremediation of petroleum hydrocarbon contaminated soil by Rhodobacter sphaeroides biofertilizer and plants.

    Science.gov (United States)

    Jiao, Haihua; Luo, Jinxue; Zhang, Yiming; Xu, Shengjun; Bai, Zhihui; Huang, Zhanbin

    2015-09-01

    Bio-augmentation is a promising technique for remediation of polluted soils. This study aimed to evaluate the bio-augmentation effect of Rhodobacter sphaeroides biofertilizer (RBF) on the bioremediation of total petroleum hydrocarbons (TPH) contaminated soil. A greenhouse pot experiment was conducted over a period of 120 days, three methods for enhancing bio-augmentation were tested on TPH contaminated soils, including single addition RBF, planting, and combining of RBF and three crop species, such as wheat (W), cabbage (C) and spinach (S), respectively. The results demonstrated that the best removal of TPH from contaminated soil in the RBF bio-augmentation rhizosphere soils was found to be 46.2%, 65.4%, 67.5% for W+RBF, C+RBF, S+RBF rhizosphere soils respectively. RBF supply impacted on the microbial community diversity (phospholipid fatty acids, PLFA) and the activity of soil enzymes, such as dehydrogenase (DH), alkaline phosphatase (AP) and urease (UR). There were significant difference among the soil only containing crude oil (CK), W, C and S rhizosphere soils and RBF bio-augmentation soils. Moreover, the changes were significantly distinct depended on crops species. It was concluded that the RBF is a valuable material for improving effect of remediation of TPH polluted soils.

  16. Field evidence for the potential of Rhodobacter capsulatus as Biofertilizer for flooded rice.

    Science.gov (United States)

    Gamal-Eldin, Hosny; Elbanna, Khaled

    2011-02-01

    In a previous study, we evaluated the effects of inoculating rice plants with the phototrophic purple nonsulfur bacterium Rhodobacter capsulatus (Rc) on growth and yield of rice in pots and lysimeter experiments and the results obtained have been highly encouraging. In this study, we carried out two field experiments: one in the experimental farm of the Faculty of Agriculture, Fayoum University, and the second in a farmer's field in Kafr El-sheikh, to assess the effects of Rc on growth and yield of rice in comparison and in combination with chemical nitrogen fertilizer (CNF) and farmyard manure. The results indicated that both biological and grain yields in all the Rc inoculated treatments were significantly higher than those in the uninoculated corresponding treatments in both fields. With regard to grain yield, the major factor for determining the effectiveness of any agricultural treatment, inoculation with Rc in combination with 50% of the recommended CNF rate gave a grain yield that was statistically equivalent to that obtained with 100% of the recommended CNF rate. These results provide a clear evidence for the potential of Rc as biofertilizer for flooded rice under field conditions.

  17. Redox potential tuning through differential quinone binding in the photosynthetic reaction center of Rhodobacter sphaeroides.

    Science.gov (United States)

    Vermaas, Josh V; Taguchi, Alexander T; Dikanov, Sergei A; Wraight, Colin A; Tajkhorshid, Emad

    2015-03-31

    Ubiquinone forms an integral part of the electron transport chain in cellular respiration and photosynthesis across a vast number of organisms. Prior experimental results have shown that the photosynthetic reaction center (RC) from Rhodobacter sphaeroides is only fully functional with a limited set of methoxy-bearing quinones, suggesting that specific interactions with this substituent are required to drive electron transport and the formation of quinol. The nature of these interactions has yet to be determined. Through parameterization of a CHARMM-compatible quinone force field and subsequent molecular dynamics simulations of the quinone-bound RC, we have investigated and characterized the interactions of the protein with the quinones in the Q(A) and Q(B) sites using both equilibrium simulation and thermodynamic integration. In particular, we identify a specific interaction between the 2-methoxy group of ubiquinone in the Q(B) site and the amide nitrogen of GlyL225 that we implicate in locking the orientation of the 2-methoxy group, thereby tuning the redox potential difference between the quinones occupying the Q(A) and Q(B) sites. Disruption of this interaction leads to weaker binding in a ubiquinone analogue that lacks a 2-methoxy group, a finding supported by reverse electron transfer electron paramagnetic resonance experiments of the Q(A)⁻Q(B)⁻ biradical and competitive binding assays.

  18. Crystallization of a flavodoxin involved in nitrogen fixation in Rhodobacter capsulatus

    International Nuclear Information System (INIS)

    Pérez-Dorado, Inmaculada; Bortolotti, Ana; Cortez, Néstor; Hermoso, Juan A.

    2008-01-01

    The flavodoxin NifF from R. capsulatus, a candidate for nitrogenase reduction during nitrogen fixation, has been crystallized using the hanging-drop vapour-diffusion method. Preliminary X-ray data processing at 2.17 Å resolution allowed determination of the crystal system and unit-cell parameters. Flavodoxins are small electron-transfer proteins that contain one molecule of noncovalently bound flavin mononucleotide (FMN). The flavodoxin NifF from the photosynthetic bacterium Rhodobacter capsulatus is reduced by one electron from ferredoxin/flavodoxin:NADP(H) reductase and was postulated to be an electron donor to nitrogenase in vivo. NifF was cloned and overexpressed in Escherichia coli, purified and concentrated for crystallization using the hanging-drop vapour-diffusion method at 291 K. Crystals grew from a mixture of PEG 3350 and PEG 400 at pH 5.5 and belong to the tetragonal space group P4 1 2 1 2, with unit-cell parameters a = b = 66.49, c = 121.32 Å. X-ray data sets have been collected to 2.17 Å resolution

  19. Study of the selenite reduction in Rhodobacter sphaeroides f. sp. denitrificans

    International Nuclear Information System (INIS)

    Bernier-Pierru, B.

    2006-05-01

    Selenium is an essential element for all living organisms at the low level; however it becomes toxic and mutagenic at higher concentrations. The predominant forms of selenium in natural environments are selenate and selenite which are toxic. Bacteria can use several mechanisms of detoxification such as methylation in volatile compounds or reduction in elemental selenium. In this way, our model, Rhodobacter sphaeroides f. sp. denitrificans, is able to reduce selenite into selenium. We have combined biochemical and molecular approaches to better characterize the mechanism and protagonists of this reduction. After studying the physiological response of the bacterium in the presence of selenite, we screened a transposon library in order to isolate mutants with a weakened reduction ability. Two of these selected mutants are affected in genes involved in the molybdenum cofactor synthesis, moaA and mogA. Several reductases, the molybdo enzymes, required this cofactor. Furthermore the addition of tungsten, a competitor for the molybdenum, in the culture medium, dramatically reduces the rate of selenite reduction. These results strongly suggest that a molybdo enzyme is involved in one of the selenite reduction pathways. The potential role of different proteins has been investigated, especially for the nitrate reductase, the DMSO reductase and the biotin sulfoxide reductase. We have also selected a mutant affected in the smoM gene which encodes a peri-plasmic component of a TRAP transporter. The phenotype of this mutant suggests the involvement of this transporter in the selenite import. (author)

  20. Pemanfaatan Limbah Cangkang Kerang Hijau (Perna Viridis Menjadi Kitin Sebagai Biokoagulan Air Sungai

    Directory of Open Access Journals (Sweden)

    Syamsidar HS

    2017-06-01

    Full Text Available This study aims to determine the optimum weight of chitin that used as biocoagulant of river water. The water sample is taken from Kajenjeng river and the chitin used for research are isolated from green mussels (Perna viridis shell powder through three steps such as deproteination by NaOH 3%, demineralization by HCl 1,25 N and depigmentation by NaOCl 4%. Then, the obtained chitin are contacted into water with variation of 0,25 gram; 0,5 gram; 0,75 gram and 1 gram in an hour. The result showed that optimum weight of chitin for COD determination, total hardness, calcium and turbidity is 0,75 gram, while optimum weight of chitin for magnesium determination is 0,5 gram.

  1. Larval development and shape variation of the kelpfish Myxodes viridis (Teleostei: Clinidae

    Directory of Open Access Journals (Sweden)

    Francisca Zavala-Muñoz

    2016-03-01

    Full Text Available Larval development and shape ontogeny of the kelpfish Myxodes viridis (Clinidae are described for the first time. A total of 214 individuals ranging between 3.51 and 23.09 mm standard length collected off central Chile were assessed employing classic and geometric morphometrics, illustration with camera lucida and a double-staining technique for cartilaginous and bone structure observation. Based on characteristics such as yolk sac presence and fin formation, six stages of larval development were differentiated: yolk sac, preflexion, flexion, early postflexion, late postflexion and juvenile. Shape changes during development are subtle and occur smoothly, being more significant in the head and preanal length, and ontogenetic allometry accounts for almost 15%. Cartilage formation takes place first at the branchial arches and cranium; then hypural, haemal and neural arches are consecutively formed. Bony structure ossification occurs late in the development. Vertebral centra ossify directly, without cartilaginous matrix replacement.

  2. Identification of Listeria monocytogenes on Green Mussels (Perna viridis and Cockle Shell (Anadara granosa

    Directory of Open Access Journals (Sweden)

    Winiati Puji Rahayu

    2016-12-01

    Full Text Available Green mussel (Perna viridis and cockle shell (Anadara granosa are one of many sources of animalprotein which is many cultivated in Indonesia because their price is relatively affordable. This study wasconducted to identify the presence of Listeria monocytogenes in 27 samples of green mussels and 3 samplesof cockle shells using real-time Polymerase Chain Reaction (real-time PCR and biochemical methods. Thetarget gene for amplification in real-time PCR was an hlyA gene because this gene was a determinant ofvirulence genes that produce listeriolysin O. Primers used in this study were forward primer DG69 (GTGCCG GGT AAA AGA CCA TA and reverse primer DG74 (CGC CAC TGA GAT ACT AT and fluorescencesignals indicator using SYBR Green I. The results of analysis using real-time PCR were negative Listeriamonocytogenes in all samples, while using biochemical methods there was one of 30 samples contaminatedby Listeria welshimeri.

  3. Identification of lysozyme activity from two edible bivalves - Perna viridis (Linnaeus) and Meretrix casta (Chemnitz)

    Digital Repository Service at National Institute of Oceanography (India)

    Sharma, S.; Tanu; Chatterji, A.

    on the column. Fractions of 1 ml each were collected. The absorbance of these fractions was also monitored at 280 nm. The lysozyme activity was checked against Micrococcus luteus. Ion exchange chromatography - The lyophilized active samples (McL2 and PvL2... in the case of M. casta – McL1, McL2 (fr 7), McL3, McL4, McL5 and McL6, and 7 in the case of P. viridis - PvL1, PvL2 (fr 5), PvL3, PvL4, PvL5, PvL6, PvL 7. Fig. 2: Absorbance of Sephadex fractions of M. casta at 280 nm Absorbance at 280 nm Fig. 3...

  4. Chloride transport in toad skin (Bufo viridis). The effect of salt adaptation

    DEFF Research Database (Denmark)

    Katz, U; Larsen, Erik Hviid

    1984-01-01

    The steady-state Cl- current across the skin of Bufo viridis adapted to tap water was found to be rectified. In skins bathed with NaCl Ringer on both sides, a large outward current, carried by influx of Cl-, was observed at a clamping voltage (V) of less than -50 mV (outside of the skin negative......, and apparent leakage conductance was reduced. Application of the phosphodiesterase inhibitor 3-isobutyl-1-methyl-xanthine to skin of fully salt-adapted toads increased the transepithelial Cl- conductance, and the time courses of voltage clamp currents became more like those of water-adapted toads. Apparent...... leakage conductance was increased.(ABSTRACT TRUNCATED AT 400 WORDS)...

  5. Microsporidia in a woodland pool I. Lanatospora costata sp. n. (Opisthosporidia, Microsporidia), parasite of Megacyclops viridis (Crustacea, Copepoda): fine structure and molecular phylogeny

    Czech Academy of Sciences Publication Activity Database

    Vávra, Jiří; Hyliš, M.; Fiala, Ivan; Refardt, D.; Larsson, J.I.R.

    2016-01-01

    Roč. 55, č. 4 (2016), s. 269-280 ISSN 0065-1583 Institutional support: RVO:60077344 Keywords : microsporidian parasite * Megacyclops viridis * SSU rRNA Subject RIV: EE - Microbiology, Virology Impact factor: 1.481, year: 2016

  6. Udbredelsen af den invasive børsteorm, Marenzelleria viridis, langs danske kyster – tegn på økologiske konsekvenser?

    DEFF Research Database (Denmark)

    Banta, Gary Thomas; Christoffersen, Kenn

    ud af de 6 resterende stationer vi undersøgte. Antallet af M. viridis på disse stationer var dog beskeden (... tæthed af M. viridis og en række sediment og abiotiske parametre, hvilket bekræfter artens store tolerance overfor det omskiftelige brakvands miljø og sediment karakteristika, der kendetegner de danske kyster. Disse abiotiske parametre understøtter dog forekomsten af lige netop M. viridis frem for de...... andre søskendearter, da sidstnævnte fortrækker enten lavere salinitet eller lavere temperatur end typisk for de danske kyster. Der blev observerede nogle svage negative sammenhæng mellem Marenzelleria viridis og de naturligt forekommende arter, såsom Hediste (Nereis) diversicolor, Corophium spp. og...

  7. Chemical composition and antifungal activity of the essential oils of Lavandula viridis L'Her.

    Science.gov (United States)

    Zuzarte, Mónica; Gonçalves, Maria José; Cavaleiro, Carlos; Canhoto, Jorge; Vale-Silva, Luís; Silva, Maria João; Pinto, Eugénia; Salgueiro, Lígia

    2011-05-01

    In the present work we report for what we believe to be the first time the antifungal activity and mechanism of action of the essential oils of Lavandula viridis from Portugal. The essential oils were isolated by hydrodistillation and analysed by GC and GC/MS. The MIC and the minimal lethal concentration (MLC) of the essential oil and its major compounds were determined against several pathogenic fungi. The influence of subinhibitory concentrations of the essential oil on the dimorphic transition in Candida albicans was also studied, as well as propidium iodide and FUN-1 staining of Candida albicans cells by flow cytometry following short treatments with the essential oil. The oils were characterized by a high content of oxygen-containing monoterpenes, with 1,8-cineole being the main constituent. Monoterpene hydrocarbons were present at lower concentrations. According to the determined MIC and MLC values, the dermatophytes and Cryptococcus neoformans were the most sensitive fungi (MIC and MLC values ranging from 0.32 to 0.64 µl ml⁻¹), followed by Candida species (at 0.64-2.5 µl ml⁻¹). For most of these strains, MICs were equivalent to MLCs, indicating a fungicidal effect of the essential oil. The oil was further shown to completely inhibit filamentation in Candida albicans at concentrations well below the respective MICs (as low as MIC/16). Flow cytometry results suggested a mechanism of action ultimately leading to cytoplasmic membrane disruption and cell death. Our results show that L. viridis essential oils may be useful in the clinical treatment of fungal diseases, particularly dermatophytosis and candidosis, although clinical trials are required to evaluate the practical relevance of our in vitro research.

  8. MODULACIÓN DE LA SINTESIS DE METALOTIONINAS EN Perna viridis PREEXPUESTOS A COBRE Y EXPUESTOS A CADMIO | MODULATION OF METALLOTHIONEIN SYNTHESIS IN Perna viridis PRE EXPOSED TO COPPER AND EXPOSED TO CADMIUM

    Directory of Open Access Journals (Sweden)

    Marín Lemus,

    2014-02-01

    Full Text Available The metallothioneins (Mts have been used as biomarkers because toxic metals such as Hg, Cd, Cu can induce their synthesis; however, environmental factors and the presence of other xenobiotics can determine the magnitude of the response in future exposures to metal ions. Metallothionein concentration was determinate in the soft tissue of Perna viridis juveniles pre-exposed to Cu and exposed to Cd (Cu/Cd for 21 days. For this, three experimental groups were established: exposed to Cd, pre-exposed to Cu and exposed to Cd and the control group (no metal. Cadmium accumulation in tissues of P. viridis was significantly higher in pre-exposed organisms to Cu, with an average value of 6.6 ± 1.9 mg/g, while in those exposed to Cd, was 4.7 ± 2.4 mg/g. Mts concentrations were also higher in the Cu/Cd experimental group, with a value of 1.36 ± 0.52 mg/g in relation to those exposed to Cd which had a value of 0.79 ± 0.47 mg/g. The relationship between Mts and bioaccumulation of Cd was significant in the group exposed to Cd, but not in the exposed Cu/Cd. These results suggest that Cu possibly acted as an inducer of Mts in the body, which led to increased accumulation of Cd in P. viridis and increase in Mts concentration. Tolerance and bioaccumulation of Cd in P. viridis was determined by previous exposure of the organism and hence its response on levels of MTs also depends on it.

  9. Connectivity of the intracytoplasmic membrane of Rhodobacter sphaeroides: a functional approach.

    Science.gov (United States)

    Verméglio, André; Lavergne, Jérôme; Rappaport, Fabrice

    2016-01-01

    The photosynthetic apparatus in the bacterium Rhodobacter sphaeroides is mostly present in intracytoplasmic membrane invaginations. It has long been debated whether these invaginations remain in topological continuity with the cytoplasmic membrane, or form isolated chromatophore vesicles. This issue is revisited here by functional approaches. The ionophore gramicidin was used as a probe of the relative size of the electro-osmotic units in isolated chromatophores, spheroplasts, or intact cells. The decay of the membrane potential was monitored from the electrochromic shift of carotenoids. The half-time of the decay induced by a single channel in intact cells was about 6 ms, thus three orders of magnitude slower than in isolated chromatophores. In spheroplasts obtained by lysis of the cell wall, the single channel decay was still slower (~23 ms) and the sensitivity toward the gramicidin concentration was enhanced 1,000-fold with respect to isolated chromatophores. These results indicate that the area of the functional membrane in cells or spheroplasts is about three orders of magnitude larger than that of isolated chromatophores. Intracytoplasmic vesicles, if present, could contribute to at most 10% of the photosynthetic apparatus in intact cells of Rba. sphaeroides. Similar conclusions were obtained from the effect of a ∆pH-induced diffusion potential in intact cells. This caused a large electrochromic response of carotenoids, of similar amplitude as the light-induced change, indicating that most of the system is sensitive to a pH change of the external medium. A single internal membrane and periplasmic space may offer significant advantages concerning renewal of the photosynthetic apparatus and reallocation of the components shared with other bioenergetic pathways.

  10. The organization of LH2 complexes in membranes from Rhodobacter sphaeroides.

    Science.gov (United States)

    Olsen, John D; Tucker, Jaimey D; Timney, John A; Qian, Pu; Vassilev, Cvetelin; Hunter, C Neil

    2008-11-07

    The mapping of the photosynthetic membrane of Rhodobacter sphaeroides by atomic force microscopy (AFM) revealed a unique organization of arrays of dimeric reaction center-light harvesting I-PufX (RC-LH1-PufX) core complexes surrounded and interconnected by light-harvesting LH2 complexes (Bahatyrova, S., Frese, R. N., Siebert, C. A., Olsen, J. D., van der Werf, K. O., van Grondelle, R., Niederman, R. A., Bullough, P. A., Otto, C., and Hunter, C. N. (2004) Nature 430, 1058-1062). However, membrane regions consisting solely of LH2 complexes were under-represented in these images because these small, highly curved areas of membrane rendered them difficult to image even using gentle tapping mode AFM and impossible with contact mode AFM. We report AFM imaging of membranes prepared from a mutant of R. sphaeroides, DPF2G, that synthesizes only the LH2 complexes, which assembles spherical intracytoplasmic membrane vesicles of approximately 53 nm diameter in vivo. By opening these vesicles and adsorbing them onto mica to form small, LH2-only membranes for the first time. The transition from highly curved vesicle to the planar sheet is accompanied by a change in the packing of the LH2 complexes such that approximately half of the complexes are raised off the mica surface by approximately 1 nm relative to the rest. This vertical displacement produces a very regular corrugated appearance of the planar membrane sheets. Analysis of the topographs was used to measure the distances and angles between the complexes. These data are used to model the organization of LH2 complexes in the original, curved membrane. The implications of this architecture for the light harvesting function and diffusion of quinones in native membranes of R. sphaeroides are discussed.

  11. Reduction of chalcogen oxyanions and generation of nanoprecipitates by the photosynthetic bacterium Rhodobacter capsulatus

    Energy Technology Data Exchange (ETDEWEB)

    Borghese, Roberto, E-mail: roberto.borghese@unibo.it [Department of Pharmacy and Biotechnology, University of Bologna (Italy); Baccolini, Chiara; Francia, Francesco [Department of Pharmacy and Biotechnology, University of Bologna (Italy); Sabatino, Piera [Department of Chemistry G. Ciamician, University of Bologna (Italy); Turner, Raymond J. [Department of Biological Sciences, University of Calgary, Calgary, Alberta (Canada); Zannoni, Davide, E-mail: davide.zannoni@unibo.it [Department of Pharmacy and Biotechnology, University of Bologna (Italy)

    2014-03-01

    Graphical abstract: - Highlights: • R. capsulatus cells produce extracellular chalcogens nanoprecipitates when lawsone is present. • Lawsone acts as a redox mediator from reducing equivalents to tellurite and selenite. • Nanoprecipitates production depends on carbon source and requires metabolically active cells. • Te{sup 0} and Se{sup 0} nanoprecipitates are identified by X-ray diffraction (XRD) spectroscopy. - Abstract: The facultative photosynthetic bacterium Rhodobacter capsulatus is characterized in its interaction with the toxic oxyanions tellurite (Te{sup IV}) and selenite (Se{sup IV}) by a highly variable level of resistance that is dependent on the growth mode making this bacterium an ideal organism for the study of the microbial interaction with chalcogens. As we have reported in the past, while the oxyanion tellurite is taken up by R. capsulatus cells via acetate permease and it is reduced to Te{sup 0} in the cytoplasm in the form of splinter-like black intracellular deposits no clear mechanism was described for Se{sup 0} precipitation. Here, we present the first report on the biotransformation of tellurium and selenium oxyanions into extracellular Te{sup 0} and Se{sup 0}nanoprecipitates (NPs) by anaerobic photosynthetically growing cultures of R. capsulatus as a function of exogenously added redox-mediator lawsone, i.e. 2-hydroxy-1,4-naphthoquinone. The NPs formation was dependent on the carbon source used for the bacterial growth and the rate of chalcogen reduction was constant at different lawsone concentrations, in line with a catalytic role for the redox mediator. X-ray diffraction (XRD) analysis demonstrated the Te{sup 0} and Se{sup 0} nature of the nanoparticles.

  12. Photo dynamics of BLUF domain mutant H44R of AppA from Rhodobacter sphaeroides

    International Nuclear Information System (INIS)

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

    2007-01-01

    The photo-cycle dynamics of the H44R mutant of the BLUF domain of the transcriptional anti-repressor protein AppA (AppA-H44R) from the non-sulfur anoxyphototropic purple bacterium Rhodobacter sphaeroides is studied in order to gain information on the involvement of His44 in the photo-cyclic mechanism of the AppA BLUF domain and to add information to the involved processes. The amino acid residue histidine at position 44 is replaced by arginine. A 12 nm red-shifted signalling state is formed upon blue-light excitation, while in wild-type AppA (AppA-wt) the red-shift is 16 nm. The recovery to the receptor dark state is approximately a factor of 2.5 faster (τ rec ∼ 6.5 min) than the recovery of the wild-type counterpart. Extended light exposure of the mutant causes photo-degradation of flavin (mainly free flavin conversion to lumichrome and re-equilibration between free and non-covalently bound flavin) and protein aggregation (showing up as light scattering). No photo-degradation was observed for AppA-wt. The quantum efficiency of signalling-state formation determined by intensity dependent absorption measurements is found to be φ s ∼ 0.3 (for AppA-wt: φ s ∼ 0.24). A two-component single-exponential fluorescence relaxation was observed, which is interpreted as fast fluorescence quenching to an equilibrium value by photo-induced electron transfer followed by slower fluorescence decay due to charge recombination. Based on the experimental findings, an extended photo-cycle model for BLUF domains is proposed

  13. Rhodobacter capsulatus gains a competitive advantage from respiratory nitrate reduction during light-dark transitions.

    Science.gov (United States)

    Ellington, M J K; Richardson, D J; Ferguson, S J

    2003-04-01

    Rhodobacter capsulatus N22DNAR(+) possesses a periplasmic nitrate reductase and is capable of reducing nitrate to nitrite under anaerobic conditions. In the absence of light this ability cannot support chemoheterotrophic growth in batch cultures. This study investigated the effect of nitrate reduction on the growth of R. capsulatus N22DNAR(+) during multiple light-dark cycles of anaerobic photoheterotrophic/dark chemoheterotrophic growth conditions in carbon-limited continuous cultures. The reduction of nitrate did not affect the photoheterotrophic growth yield of R. capsulatus N22DNAR(+). After a transition from photoheterotrophic to dark chemoheterotrophic growth conditions, the reduction of nitrate slowed the initial washout of a R. capsulatus N22DNAR(+) culture. Towards the end of a period of darkness nitrate-reducing cultures maintained higher viable cell counts than non-nitrate-reducing cultures. During light-dark cycling of a mixed culture, the strain able to reduce nitrate (N22DNAR(+)) outcompeted the strain which was unable to reduce nitrate (N22). The evidence indicates that the periplasmic nitrate reductase activity supports slow growth that retards the washout of a culture during anaerobic chemoheterotrophic conditions, and provides a protonmotive force for cell maintenance during the dark period before reillumination. This translates into a selective advantage during repeated light-dark cycles, such that in mixed culture N22DNAR(+) outcompetes N22. Exposure to light-dark cycles will be a common feature for R. capsulatus in its natural habitats, and this study shows that nitrate respiration may provide a selective advantage under such conditions.

  14. Reprint of “Extracellular production of tellurium nanoparticles by the photosynthetic bacterium Rhodobacter capsulatus”

    Energy Technology Data Exchange (ETDEWEB)

    Borghese, Roberto, E-mail: roberto.borghese@unibo.it [Dept. of Pharmacy and Biotechnology, University of Bologna (Italy); Brucale, Marco [Institute for the Study of Nanostructured Materials (CNR-ISMN), Rome (Italy); Fortunato, Gianuario [Dept. of Pharmacy and Biotechnology, University of Bologna (Italy); Lanzi, Massimiliano [Dept. of Industrial Chemistry “Toso Montanari”, University of Bologna (Italy); Mezzi, Alessio [Institute for the Study of Nanostructured Materials (CNR-ISMN), Rome (Italy); Valle, Francesco; Cavallini, Massimiliano [Institute for the Study of Nanostructured Materials (CNR-ISMN), Bologna (Italy); Zannoni, Davide [Dept. of Pharmacy and Biotechnology, University of Bologna (Italy)

    2017-02-15

    Highlights: • Tellurite is reduced by R. capsulatus as cytosolic tellurium nanoprecipitates TeNPs. • Lawsone allows R. capsulatus to produce extracellular TeNPs. • Extracellular TeNPs production depends on the carbon source used for cells growth. • Both lawsone concentration and the incubation time determine the TeNPs size. • Extracellular TeNPs are coated with extracellular polymeric substances (EPS). - Abstract: The toxic oxyanion tellurite (TeO{sub 3}{sup 2−}) is acquired by cells of Rhodobacter capsulatus grown anaerobically in the light, via acetate permease ActP2 and then reduced to Te{sup 0} in the cytoplasm as needle-like black precipitates. Interestingly, photosynthetic cultures of R. capsulatus can also generate Te{sup 0} nanoprecipitates (TeNPs) outside the cells upon addition of the redox mediator lawsone (2-hydroxy-1,4-naphtoquinone). TeNPs generation kinetics were monitored to define the optimal conditions to produce TeNPs as a function of various carbon sources and lawsone concentration. We report that growing cultures over a 10 days period with daily additions of 1 mM tellurite led to the accumulation in the growth medium of TeNPs with dimensions from 200 up to 600–700 nm in length as determined by atomic force microscopy (AFM). This result suggests that nucleation of TeNPs takes place over the entire cell growth period although the addition of new tellurium Te{sup 0} to pre-formed TeNPs is the main strategy used by R. capsulatus to generate TeNPs outside the cells. Finally, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) analysis of TeNPs indicate they are coated with an organic material which keeps the particles in solution in aqueous solvents.

  15. Bioremediation of cadmium- and zinc-contaminated soil using Rhodobacter sphaeroides.

    Science.gov (United States)

    Peng, Weihua; Li, Xiaomin; Song, Jingxiang; Jiang, Wei; Liu, Yingying; Fan, Wenhong

    2018-04-01

    Bioremediation using microorganisms is a promising technique to remediate soil contaminated with heavy metals. In this study, Rhodobacter sphaeroides was used to bioremediate soils contaminated with cadmium (Cd) and zinc (Zn). The study found that the treatment reduced the overall bioavailable fractions (e.g., exchangeable and carbonate bound phases) of Cd and Zn. More stable fractions (e.g., Fe-Mn oxide, organic bound, and residual phases (only for Zn)) increased after bioremediation. A wheat seedling experiment revealed that the phytoavailability of Cd was reduced after bioremediation using R. sphaeroides. After bioremediation, the exchangeable phases of Cd and Zn in soil were reduced by as much as 30.7% and 100.0%, respectively; the Cd levels in wheat leaf and root were reduced by as much as 62.3% and 47.2%, respectively. However, when the soils were contaminated with very high levels of Cd and Zn (Cd 54.97-65.33 mg kg -1 ; Zn 813.4-964.8 mg kg -1 ), bioremediation effects were not clear. The study also found that R. sphaeroides bioremediation in soil can enhance the Zn/Cd ratio in the harvested wheat leaf and root overall. This indicates potentially favorable application in agronomic practice and biofortification. Although remediation efficiency in highly contaminated soil was not significant, R. sphaeroides may be potentially and practically applied to the bioremediation of soils co-contaminated by Cd and Zn. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Cloning, DNA sequence, and expression of the Rhodobacter sphaeroides cytochrome c/sub 2/ gene

    Energy Technology Data Exchange (ETDEWEB)

    Donohue, T.J.; McEwan, A.G.; Kaplan, S.

    1986-11-01

    The Rhodobacter sphaeroides cytochrome c/sub 2/ functions as a mobile electron carrier in both aerobic and photosynthetic electron transport chains. Synthetic deoxyoligonucleotide probes, based on the known amino acid sequence of this protein (M/sub r/ 14,000), were used to identify and clone the cytochrome c/sub 2/ structural gene (cycA). DNA sequence analysis of the cycA gene indicated the presence of a typical procaryotic 21-residue signal sequence, suggesting that this periplasmic protein is synthesized in vivo as a precursor. Synthesis of an immunoreactive cytochrome c/sub 2/ precursor protein (M/sub r/ 15,500) was observed in vitro when plasmids containing the cycA gene were used as templates in an R. sphaeroides coupled transcription-translation system. Approximately 500 base pairs of DNA upstream of the cycA gene was sufficient to allow expression of this gene product in vitro. Northern blot analysis with an internal cycA-specific probe identified at least two possibly monocistronic transcripts present in both different cellular levels and relative stoichiometries in steady-state cells grown under different physiological conditions. The ratio of the small (740-mucleotide) and large (920-nucleotide) cycA-specific mRNA species was dependent on cultural conditions but was not affected by light intensity under photosynthetic conditions. These results suggest that the increase in the cellular level of the cytochrome c/sub 2/ protein found in photosynthetic cells was due, in part, to increased transcription of the single-copy cyc operon.

  17. Photo dynamics of BLUF domain mutant H44R of AppA from Rhodobacter sphaeroides

    Energy Technology Data Exchange (ETDEWEB)

    Zirak, P. [Institut II - Experimentelle und Angewandte Physik, Universitaet Regensburg, Universitaetstrasse 31, D-93053 Regensburg (Germany); Penzkofer, A. [Institut II - Experimentelle und Angewandte Physik, Universitaet Regensburg, Universitaetstrasse 31, D-93053 Regensburg (Germany)], E-mail: alfons.penzkofer@physik.uni-regensburg.de; Hegemann, P.; Mathes, T. [Institut fuer Biologie, Experimentelle Biophysik, Humboldt-Universitaet zu Berlin, Invalidenstr. 42, D-10115 Berlin (Germany)

    2007-05-21

    The photo-cycle dynamics of the H44R mutant of the BLUF domain of the transcriptional anti-repressor protein AppA (AppA-H44R) from the non-sulfur anoxyphototropic purple bacterium Rhodobacter sphaeroides is studied in order to gain information on the involvement of His44 in the photo-cyclic mechanism of the AppA BLUF domain and to add information to the involved processes. The amino acid residue histidine at position 44 is replaced by arginine. A 12 nm red-shifted signalling state is formed upon blue-light excitation, while in wild-type AppA (AppA-wt) the red-shift is 16 nm. The recovery to the receptor dark state is approximately a factor of 2.5 faster ({tau}{sub rec} {approx} 6.5 min) than the recovery of the wild-type counterpart. Extended light exposure of the mutant causes photo-degradation of flavin (mainly free flavin conversion to lumichrome and re-equilibration between free and non-covalently bound flavin) and protein aggregation (showing up as light scattering). No photo-degradation was observed for AppA-wt. The quantum efficiency of signalling-state formation determined by intensity dependent absorption measurements is found to be {phi}{sub s} {approx} 0.3 (for AppA-wt: {phi}{sub s} {approx} 0.24). A two-component single-exponential fluorescence relaxation was observed, which is interpreted as fast fluorescence quenching to an equilibrium value by photo-induced electron transfer followed by slower fluorescence decay due to charge recombination. Based on the experimental findings, an extended photo-cycle model for BLUF domains is proposed.

  18. Photo dynamics of BLUF domain mutant H44R of AppA from Rhodobacter sphaeroides

    Science.gov (United States)

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

    2007-05-01

    The photo-cycle dynamics of the H44R mutant of the BLUF domain of the transcriptional anti-repressor protein AppA (AppA-H44R) from the non-sulfur anoxyphototropic purple bacterium Rhodobacter sphaeroides is studied in order to gain information on the involvement of His44 in the photo-cyclic mechanism of the AppA BLUF domain and to add information to the involved processes. The amino acid residue histidine at position 44 is replaced by arginine. A 12 nm red-shifted signalling state is formed upon blue-light excitation, while in wild-type AppA (AppA-wt) the red-shift is 16 nm. The recovery to the receptor dark state is approximately a factor of 2.5 faster ( τrec ≈ 6.5 min) than the recovery of the wild-type counterpart. Extended light exposure of the mutant causes photo-degradation of flavin (mainly free flavin conversion to lumichrome and re-equilibration between free and non-covalently bound flavin) and protein aggregation (showing up as light scattering). No photo-degradation was observed for AppA-wt. The quantum efficiency of signalling-state formation determined by intensity dependent absorption measurements is found to be ϕs ≈ 0.3 (for AppA-wt: ϕs ≈ 0.24). A two-component single-exponential fluorescence relaxation was observed, which is interpreted as fast fluorescence quenching to an equilibrium value by photo-induced electron transfer followed by slower fluorescence decay due to charge recombination. Based on the experimental findings, an extended photo-cycle model for BLUF domains is proposed.

  19. Reusing pulp and paper mill effluent as a bioresource to produce biohydrogen through ultrasonicated Rhodobacter sphaeroides

    International Nuclear Information System (INIS)

    Hay, Jacqueline Xiao Wen; Wu, Ta Yeong; Ng, Boon Junn; Juan, Joon Ching; Md Jahim, Jamaliah

    2016-01-01

    Highlights: • Ultrasonication pretreatment on R. sphaeroides enhanced biohydrogen production. • Pretreatment using amplitude 30% for 10 min gave the highest biohydrogen yield. • Pretreatment using amplitude 45% for 15 min inhibited biohydrogen production. - Abstract: Pulp and paper industry is a water-intensive industry. This industry commonly produces considerable amount of effluent, especially from virgin raw materials processing. The effluent, namely pulp and paper mill effluent has the potential to adversely affect the receiving watercourses. However, the nutrients in the pulp and paper mill effluent could be reused as a substrate in biohydrogen production. In this study, photofermentative biohydrogen production was investigated using Rhodobacter sphaeroides and pulp and paper mill effluent as a substrate. An application of low power ultrasound on R. sphaeroides was predicted to increase photofermentative biohydrogen production but excessive ultrasound effects might inhibit the production due to possible cell disruption. Hence, various ultrasonication duration (5, 10 and 15 min) and amplitude (15%, 30% and 45%) were applied on the bacteria to determine the recommended ultrasonication conditions for improving biohydrogen production. The recommended conditions were operated at ultrasonication amplitude and duration of 30% and 10 min, respectively. A maximum biohydrogen yield of 9.62 mL bioH_2/mL medium was obtained under this condition, which was 66.7% higher than the result obtained using R. sphaeroides without undergoing ultrasonication (control). The light efficiency and cell concentration were increased by 67% and 150%, respectively, using ultrasonication amplitude and duration of 30% and 10 min, respectively as compared to the control. The present results demonstrated that moderate power of ultrasonication applied on R. sphaeroides was an effective method for enhancing photofermentative biohydrogen production using raw pulp and paper mill effluent as a

  20. Electrostatic dominoes: long distance propagation of mutational effects in photosynthetic reaction centers of Rhodobacter capsulatus.

    Science.gov (United States)

    Sebban, P; Maróti, P; Schiffer, M; Hanson, D K

    1995-07-04

    Two point mutants from the purple bacterium Rhodobacter capsulatus, both modified in the M protein of the photosynthetic reaction center, have been studied by flash-induced absorbance spectroscopy. These strains carry either the M231Arg --> Leu or M43ASN --> Asp mutations, which are located 9 and 15 A, respectively, from the terminal electron acceptor QB. In the wild-type Rb. sphaeroides structure, M231Arg is involved in a conserved salt bridge with H125Glu and H232Glu and M43Asn is located among several polar residues that form or surround the QB binding site. These substitutions were originally uncovered in phenotypic revertants isolated from the photosynthetically incompetent L212Glu-L213Asp --> Ala-Ala site-specific double mutant. As second-site suppressor mutations, they have been shown to restore the proton transfer function that is interrupted in the L212Ala-L213Ala double mutant. The electrostatic effects that are induced in reaction centers by the M231Arg --> Leu and M43Asn --> Asp substitutions are roughly the same in either the double-mutant or wild-type backgrounds. In a reaction center that is otherwise wild type in sequence, they decrease the free energy gap between the QA- and QB- states by 24 +/- 5 and 45 +/- 5 meV, respectively. The pH dependences of K2, the QA-QB QAQB- equilibrium constant, are altered in reaction centers that carry either of these substitutions, revealing differences in the pKas of titratable groups compared to the wild type.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Molecular genetic and molecular evolutionary studies on the bacteriochlorophyll synthesis genes of Rhodobacter capsulatus

    Energy Technology Data Exchange (ETDEWEB)

    Burke-Agueero, D.H.

    1992-08-01

    Rhodobacter capsulatus, purple bacterium capable of either aerobic or photosynthetic growth, has proven to be very useful in genetic studies of photosynthesis. Forty-four genes clustered together within a 46 kilobase region are required to establish photosynthetic ability in R. capsulatus. Approximately twenty of these genes are involved in bacteriochlorophyll synthesis of which eight bch'' genes are the subject of this thesis. Six of these genes were found to code for the two ring reductases. The first converts protochlorophyllide (PChlide) into a chlorin, the immediate precursor to chlorophyll a, and then into a bacteriochlorin. Each reductase is shown to be made up of three subunits. PChlide reductase is coded by the genes bchN, bchB, and bchL. Proteins with amino acid sequences markedly similar to those of bchN and bchL have been shown in other organisms to be required for chlorophyll synthesis; hence, their designation as chlN and chlB. A third chloroplast-encoded gene of heretofore unknown function shares amino acid identities with bchB and is probably the third subunit of the plant PChlide reductase. The bchA locus, which encodes the chlorin reductase, is found to be made up of three separate, translationally coupled genes, referred to as bchX, bchY, and bchZ. Amino acid similarities between bchX, bchL, and the nitrogenase reductase protein nifH suggest that all three classes of proteins share certain three-dimensional structural features, including elements that are central to the enzymatic mechanism of nifH. PChlide reductase and chlorin reductase are clearly derived from a common ancestor. Several lines of analysis suggests the ancestor of both enzyme systems reduced PChlide twice to produce bacteriochlorophyll supporting the concept bacteriochlorophyll as the ancestral reaction center pigment.

  2. Molecular genetic and molecular evolutionary studies on the bacteriochlorophyll synthesis genes of Rhodobacter capsulatus

    Energy Technology Data Exchange (ETDEWEB)

    Burke-Agueero, Donald H. [Univ. of California, Berkeley, CA (United States)

    1992-08-01

    Rhodobacter capsulatus, purple bacterium capable of either aerobic or photosynthetic growth, has proven to be very useful in genetic studies of photosynthesis. Forty-four genes clustered together within a 46 kilobase region are required to establish photosynthetic ability in R. capsulatus. Approximately twenty of these genes are involved in bacteriochlorophyll synthesis of which eight ``bch`` genes are the subject of this thesis. Six of these genes were found to code for the two ring reductases. The first converts protochlorophyllide (PChlide) into a chlorin, the immediate precursor to chlorophyll a, and then into a bacteriochlorin. Each reductase is shown to be made up of three subunits. PChlide reductase is coded by the genes bchN, bchB, and bchL. Proteins with amino acid sequences markedly similar to those of bchN and bchL have been shown in other organisms to be required for chlorophyll synthesis; hence, their designation as chlN and chlB. A third chloroplast-encoded gene of heretofore unknown function shares amino acid identities with bchB and is probably the third subunit of the plant PChlide reductase. The bchA locus, which encodes the chlorin reductase, is found to be made up of three separate, translationally coupled genes, referred to as bchX, bchY, and bchZ. Amino acid similarities between bchX, bchL, and the nitrogenase reductase protein nifH suggest that all three classes of proteins share certain three-dimensional structural features, including elements that are central to the enzymatic mechanism of nifH. PChlide reductase and chlorin reductase are clearly derived from a common ancestor. Several lines of analysis suggests the ancestor of both enzyme systems reduced PChlide twice to produce bacteriochlorophyll supporting the concept bacteriochlorophyll as the ancestral reaction center pigment.

  3. The prevalence of gene duplications and their ancient origin in Rhodobacter sphaeroides 2.4.1

    Directory of Open Access Journals (Sweden)

    Cho Hyuk

    2010-12-01

    Full Text Available Abstract Background Rhodobacter sphaeroides 2.4.1 is a metabolically versatile organism that belongs to α-3 subdivision of Proteobacteria. The present study was to identify the extent, history, and role of gene duplications in R. sphaeroides 2.4.1, an organism that possesses two chromosomes. Results A protein similarity search (BLASTP identified 1247 orfs (~29.4% of the total protein coding orfs that are present in 2 or more copies, 37.5% (234 gene-pairs of which exist in duplicate copies. The distribution of the duplicate gene-pairs in all Clusters of Orthologous Groups (COGs differed significantly when compared to the COG distribution across the whole genome. Location plots revealed clusters of gene duplications that possessed the same COG classification. Phylogenetic analyses were performed to determine a tree topology predicting either a Type-A or Type-B phylogenetic relationship. A Type-A phylogenetic relationship shows that a copy of the protein-pair matches more with an ortholog from a species closely related to R. sphaeroides while a Type-B relationship predicts the highest match between both copies of the R. sphaeroides protein-pair. The results revealed that ~77% of the proteins exhibited a Type-A phylogenetic relationship demonstrating the ancient origin of these gene duplications. Additional analyses on three other strains of R. sphaeroides revealed varying levels of gene loss and retention in these strains. Also, analyses on common gene pairs among the four strains revealed that these genes experience similar functional constraints and undergo purifying selection. Conclusions Although the results suggest that the level of gene duplication in organisms with complex genome structuring (more than one chromosome seems to be not markedly different from that in organisms with only a single chromosome, these duplications may have aided in genome reorganization in this group of eubacteria prior to the formation of R. sphaeroides as gene

  4. Algal genotype and photoacclimatory responses of the symbiotic alga Symbiodinium in natural populations of the sea anemone Anemonia viridis

    Science.gov (United States)

    Bythell, J. C.; Douglas, A. E.; Sharp, V. A.; Searle, J. B.; Brown, B. E.

    1997-01-01

    As an approach to investigate the impact of solar radiation on an alga–invertebrate symbiosis, the genetic variation and photosynthetic responses of the dinoflagellate algal symbiosis in an intertidal and a subtidal population of the sea anemone Anemonia viridis were explored. Allozyme analysis of the anemones indicated that the two populations were genetically very similar, with a Nei's index value of genetic identity (I) of 0.998. The algae in all animals examined were identified as Symbiodinium of clade a by PCR-RFLP analysis of the small subunit ribosomal RNA gene. The symbiosis in the two populations did not differ significantly in algal population density, chlorophyll a content per algal cell or any photosynthetic parameter obtained from studies of the relationship between photosynthesis and irradiance. We conclude that there is not necessarily genetic variation or photosynthetic plasticity of the symbiotic algae in Anemonia viridis inhabiting environments characterized by the different solar irradiances of the subtidal and intertidal habitats.

  5. Observations on a population of the sea anemone Anemonia viridis (Forskal, 1775) in the North Aegean Sea

    Energy Technology Data Exchange (ETDEWEB)

    Chariton Chintiroglou, C. [Thessaloniki, Aristotle Univ. (Greece). Dept. of Zoology

    1996-12-31

    The present paper is concerned with the structural aspects of Anemonia viridis populations found in the North Aegean Sea. It was found that mean wet weight and density of anemone populations increases with depth and distance from shore. Differences in the structure of the Anemonia viridis populations were attributed both to the specific hydrodynamic characteristics of the biotopes and to a number biotic interactions. From our results and t previous investigations the adoption of three different lifestyles by the anemones was assumed.: (1) a colonial form, with population densities around 650 individuals per m{sup 2}, found in substrates exposed to increased hydrodynamism; (2) a colonial form, with lower densities (90 indiv. per m{sup 2}), found in less exposed sites; (3) finally, large individuals in deeper waters chose a solitary lifestyle, as mechanical stresses were much lower.

  6. Bases débiles minoritarias de la raíz de Rauvolfia viridis Roem. et Schult.

    Directory of Open Access Journals (Sweden)

    Jorge A Martínez Pérez

    1997-12-01

    Full Text Available Se realizó un estudio químico de la raíz de la especie Rauvolfia viridis Roem. et Schult. que crece en Cuba, con el objetivo de profundizar en este tema. Se aislaron, purificaron y caracterizaron diferentes alcaloides correspondientes a las bases débiles, entre los que se encuentran la ajmalidina, la a-yohimbina, la quebrachidina, la reserpinina y la yohimbina. Se descarta la presencia de reserpina.It was conducted a chemical study of the root of the species Rauwolfia viridis Roem. et Schult. that grows in Cuba aimed at depening in this topic. Different alkaloids corresponding to the weak bases, such as ajmaline, a-yohimbin, quebrachidine, reserpine and yohimbin, were isolated, purified and characterized. The presence of reserpine is discarded.

  7. Complete chloroplast genome sequence of green foxtail (Setaria viridis), a promising model system for C4 photosynthesis.

    Science.gov (United States)

    Wang, Shuo; Gao, Li-Zhi

    2016-09-01

    The complete chloroplast genome of green foxtail (Setaria viridis), a promising model system for C4 photosynthesis, is first reported in this study. The genome harbors a large single copy (LSC) region of 81 016 bp and a small single copy (SSC) region of 12 456  bp separated by a pair of inverted repeat (IRa and IRb) regions of 22 315 bp. GC content is 38.92%. The proportion of coding sequence is 57.97%, comprising of 111 (19 duplicated in IR regions) unique genes, 71 of which are protein-coding genes, four are rRNA genes, and 36 are tRNA genes. Phylogenetic analysis indicated that S. viridis was clustered with its cultivated species S. italica in the tribe Paniceae of the family Poaceae. This newly determined chloroplast genome will provide valuable genetic resources to assist future studies on C4 photosynthesis in grasses.

  8. Partially Purified Extracts of Sea Anemone Anemonia viridis Affect the Growth and Viability of Selected Tumour Cell Lines

    OpenAIRE

    Bulati, Matteo; Longo, Alessandra; Masullo, Tiziana; Vlah, Sara; Bennici, Carmelo; Bonura, Angela; Salamone, Monica; Tagliavia, Marcello; Nicosia, Aldo; Mazzola, Salvatore; Colombo, Paolo; Cuttitta, Angela

    2016-01-01

    In the last few years, marine species have been investigated for the presence of natural products with anticancer activity. Using reversed phase chromatography, low molecular weight proteins were fractionated from the sea anemone Anemonia viridis. Four different fractions were evaluated for their cytotoxic activity by means of erythrocyte haemolysis test, MTS, and LDH assays. Finally, the antiproliferative activities of three of these fractions were studied on PC3, PLC/PRF/5, and A375 human c...

  9. The transcriptomic response to thermal stress is immediate, transient and potentiated by ultraviolet radiation in the sea anemone Anemonia viridis.

    Science.gov (United States)

    Moya, A; Ganot, P; Furla, P; Sabourault, C

    2012-03-01

    Among the environmental threats to coral reef health, temperature and ultraviolet increases have been proposed as major agents, although the relative contribution of each in the cnidarian/zooxanthellae symbiosis breakdown has been poorly addressed. We have investigated the transcriptomic response to thermal stress, with and without ultraviolet radiation (UVR), in the symbiotic sea anemone Anemonia viridis. Using the Oligo2K A. viridis microarray, dedicated to genes potentially involved in the symbiosis interaction, we monitored the gene expression profiles after 1, 2 and 5 days of stresses that further lead to massive losses of zooxanthellae. Each stress showed a specific gene expression profile with very little overlap. We showed that the major response to thermal stress is immediate (24 h) but returns to the baseline gene expression profile after 2 days. UVR alone has little effect but potentiates thermal stress, as a second response at 5 days was observed when the two stresses were coupled. Several pathways were highlighted, such as mesoglea loosening, cell death and calcium homeostasis and described in more details. Finally, we showed that the dermatopontin gene family, potentially involved in collagen fibrillogenesis, issued from actinarian-specific duplication events, with one member preferentially expressed in the gastroderm and specifically responding to stress. Anemonia viridis EST sequences have been deposited into GenBank dbEST ([GenBank:FK719875–FK759813]. © 2012 Blackwell Publishing Ltd.

  10. Characterization of Translationally Controlled Tumour Protein from the Sea Anemone Anemonia viridis and Transcriptome Wide Identification of Cnidarian Homologues.

    Science.gov (United States)

    Nicosia, Aldo; Bennici, Carmelo; Biondo, Girolama; Costa, Salvatore; Di Natale, Marilena; Masullo, Tiziana; Monastero, Calogera; Ragusa, Maria Antonietta; Tagliavia, Marcello; Cuttitta, Angela

    2018-01-11

    Gene family encoding translationally controlled tumour protein (TCTP) is defined as highly conserved among organisms; however, there is limited knowledge of non-bilateria. In this study, the first TCTP homologue from anthozoan was characterised in the Mediterranean Sea anemone, Anemonia viridis . The release of the genome sequence of Acropora digitifera , Exaiptasia pallida , Nematostella vectensis and Hydra vulgaris enabled a comprehensive study of the molecular evolution of TCTP family among cnidarians. A comparison among TCTP members from Cnidaria and Bilateria showed conserved intron exon organization, evolutionary conserved TCTP signatures and 3D protein structure. The pattern of mRNA expression profile was also defined in A. viridis . These analyses revealed a constitutive mRNA expression especially in tissues with active proliferation. Additionally, the transcriptional profile of A. viridis TCTP ( AvTCTP ) after challenges with different abiotic/biotic stresses showed induction by extreme temperatures, heavy metals exposure and immune stimulation. These results suggest the involvement of AvTCTP in the sea anemone defensome taking part in environmental stress and immune responses.

  11. Characterization of Translationally Controlled Tumour Protein from the Sea Anemone Anemonia viridis and Transcriptome Wide Identification of Cnidarian Homologues

    Directory of Open Access Journals (Sweden)

    Aldo Nicosia

    2018-01-01

    Full Text Available Gene family encoding translationally controlled tumour protein (TCTP is defined as highly conserved among organisms; however, there is limited knowledge of non-bilateria. In this study, the first TCTP homologue from anthozoan was characterised in the Mediterranean Sea anemone, Anemonia viridis. The release of the genome sequence of Acropora digitifera, Exaiptasia pallida, Nematostella vectensis and Hydra vulgaris enabled a comprehensive study of the molecular evolution of TCTP family among cnidarians. A comparison among TCTP members from Cnidaria and Bilateria showed conserved intron exon organization, evolutionary conserved TCTP signatures and 3D protein structure. The pattern of mRNA expression profile was also defined in A. viridis. These analyses revealed a constitutive mRNA expression especially in tissues with active proliferation. Additionally, the transcriptional profile of A. viridis TCTP (AvTCTP after challenges with different abiotic/biotic stresses showed induction by extreme temperatures, heavy metals exposure and immune stimulation. These results suggest the involvement of AvTCTP in the sea anemone defensome taking part in environmental stress and immune responses.

  12. Determination of the Phenolic Profile and Antioxidant Properties of Salvia viridis L. Shoots: A Comparison of Aqueous and Hydroethanolic Extracts

    Directory of Open Access Journals (Sweden)

    Izabela Grzegorczyk-Karolak

    2018-06-01

    Full Text Available Salvia viridis L. is an annual herb used in Mediterranean medicine. The purpose of this study was to determine the polyphenol profile of aqueous (decoction and infusion and hydroethanolic extracts of aerial parts of field-grown S.viridis and to evaluate their antioxidant activity. The polyphenol profiling was performed via UPLC-DAD/ESI-MS. Additionally, the total polyphenol content in extracts tested were determined by UV-Vis spectrophotometry using the Folin-Ciocalteu assay. The antioxidant effect was evaluated by the FRAP, DPPH, ABTS, O2•− scavenging and TBARS methods. The hydroethanolic extract gave the highest content of total phenolic compounds, followed by the infusion. The UPLC-DAD/ESI-MS analysis of extracts showed a total of 19 phenolic compounds identified as flavonoids (four compounds, phenylethanoids (eight compounds and phenolic acids (seven compounds. Rosmarinic acid was the predominant phenolic acid, verbascoside was the predominant phenylethanoid, while apigenin glucuronide or methylluteolin glucuronide, depending on the sample, were the predominant flavonoids in the analyzed extracts. The presence of a high polyphenol level indicated a high antioxidant activity of both the infusion and the hydroalcoholic extract. These results indicate that S. viridis is a rich resource of phenolic compounds and can be used in dietary applications with the potential to reduce oxidative stress.

  13. Identification of the upper exciton component of the B850 bacteriochlorophylls of the LH2 antenna complex, using a B800-free mutant of Rhodobacter sphaeroides.

    NARCIS (Netherlands)

    Koolhaas, M.H.C.; Frese, R.N.; Fowler, G.J.S.; Bibby, T.S.; Georgakopoulou, S.; van der Zwan, G.; Hunter, C.N.; van Grondelle, R.

    1998-01-01

    In this paper, we report the circular dichroism (CD) spectra of two types of LH2 -only mutants of Rhodobacter sphaeroides. In the first, only the wild type LH2 is present, while in the second, the B800 binding site of LH2 has been either destabilized or removed. For the first time, we have

  14. Two-dimensional crystals of LH2 light-harvesting complexes from Ectothiorhodospira sp. and Rhodobacter capsulatus investigated by electron microscopy.

    NARCIS (Netherlands)

    Oling, F.; Boekema, E.J.; Ortiz de Zarate, I.; Visschers, R.W.; van Grondelle, R.; Keegstra, W.; Brisson, A.; Picorel, R.

    1996-01-01

    Two-dimensional crystals of LH2 (B800-850) light-harvesting complexes from Ectothiorhodospira sp. and Rhodobacter capsulatus were obtained by reconstitution of purified protein into phospholipid vesicles and characterized by electron microscopy. The size of the crystals was up to several

  15. Exploration of the hydrogen producing potential of Rhodobacter capsulatus chemostat cultures: The application of deceleration-stat and gradient-stat methodology

    NARCIS (Netherlands)

    Hoekema, S.; Breukelen, van F.R.; Janssen, M.G.J.; Tramper, J.; Wijffels, R.H.

    2009-01-01

    In this work, the dependency of the volumetric hydrogen production rate of ammonium-limited Rhodobacter capsulatus chemostat cultures on their imposed biomass concentration and dilution rate was investigated. A deceleration-stat experiment was performed by lowering the dilution rate from 1.0 d-1 to

  16. Bacterial Survival under Extreme UV Radiation: A Comparative Proteomics Study of Rhodobacter sp., Isolated from High Altitude Wetlands in Chile

    Directory of Open Access Journals (Sweden)

    Vilma Pérez

    2017-06-01

    Full Text Available Salar de Huasco, defined as a polyextreme environment, is a high altitude saline wetland in the Chilean Altiplano (3800 m.a.s.l., permanently exposed to the highest solar radiation doses registered in the world. We present here the first comparative proteomics study of a photoheterotrophic bacterium, Rhodobacter sp., isolated from this remote and hostile habitat. We developed an innovative experimental approach using different sources of radiation (in situ sunlight and UVB lamps, cut-off filters (Mylar, Lee filters and a high-throughput, label-free quantitative proteomics method to comprehensively analyze the effect of seven spectral bands on protein regulation. A hierarchical cluster analysis of 40 common proteins revealed that all conditions containing the most damaging UVB radiation induced similar pattern of protein regulation compared with UVA and visible light spectral bands. Moreover, it appeared that the cellular adaptation of Rhodobacter sp. to osmotic stress encountered in the hypersaline environment from which it was originally isolated, might further a higher resistance to damaging UV radiation. Indeed, proteins involved in the synthesis and transport of key osmoprotectants, such as glycine betaine and inositol, were found in very high abundance under UV radiation compared to the dark control, suggesting the function of osmolytes as efficient reactive oxygen scavengers. Our study also revealed a RecA-independent response and a tightly regulated network of protein quality control involving proteases and chaperones to selectively degrade misfolded and/or damaged proteins.

  17. Biochemical analysis and the preliminary crystallographic characterization of D-tagatose 3-epimerase from Rhodobacter sphaeroides.

    Science.gov (United States)

    Qi, Zhengliang; Zhu, Zhangliang; Wang, Jian-Wen; Li, Songtao; Guo, Qianqian; Xu, Panpan; Lu, Fuping; Qin, Hui-Min

    2017-11-09

    D-Tagatose 3-epimerase epimerizes D-fructose to yield D-psicose, which is a rare sugar that exists in small quantities in nature and is difficult to synthesize chemically. We aim to explore potential industrial biocatalysts for commercial-scale manufacture of this rare sugar. A D-tagatose 3-epimerase from Rhodobacter sphaeroides (RsDTE) has recently been identified as a D-tagatose 3-epimerase that can epimerize D-fructose to yield D-psicose with a high conversion rate. The purified RsDTE by Ni-affinity chromatography, ionic exchange chromatography and gel filtration forms a tetramer in solution. The maximal activity was in Tris-HCl buffer pH 8.5, and the optimal temperature was at 35 °C. The product, D-psicose, was confirmed using HPLC and NMR. Crystals of RsDTE were obtained using crystal kits and further refined under crystallization conditions such as 10% PEG 8000,0.1 M HEPES pH 7.5, and 8% ethylene glycol at 20 °C using the sitting-drop vapor diffusion method. The RsDTE homology model showed that it possessed the characteristic TIM-barrel fold. Four residues, Glu156, Asp189, Gln215 and Glu250, forms a hydrogen bond network with the active Mn(II) for the hydride transfer reaction. These residues may constitute the catalytic tetrad of RsDTE. The residues around O1, O2 and O3 of the substrates were conserved. However, the binding-site residues are different at O4, O5 and O6. Arg118 formed the unique hydrogen bond with O4 of D-fructose which indicates RsDTE's preference of D-fructose more than any other family enzymes. RsDTE possesses a different metal-binding site. Arg118, forming unique hydrogen bond with O4 of D-fructose, regulates the substrate recognition. The research on D-tagatose 3-epimerase or D-psicose 3-epimerase enzymes attracts enormous commercial interest and would be widely used for rare sugar production in the future.

  18. Grain dust-induced lung inflammation is reduced by Rhodobacter sphaeroides diphosphoryl lipid A.

    Science.gov (United States)

    Jagielo, P J; Quinn, T J; Qureshi, N; Schwartz, D A

    1998-01-01

    To further determine the importance of endotoxin in grain dust-induced inflammation of the lower respiratory tract, we evaluated the efficacy of pentaacylated diphosphoryl lipid A derived from the lipopolysaccharide of Rhodobacter sphaeroides (RsDPLA) as a partial agonist of grain dust-induced airway inflammation. RsDPLA is a relatively inactive compound compared with lipid A derived from Escherichia coli (LPS) and has been demonstrated to act as a partial agonist of LPS-induced inflammation. To assess the potential stimulatory effect of RsDPLA in relation to LPS, we incubated THP-1 cells with RsDPLA (0.001-100 micrograms/ml), LPS (0.02 microgram endotoxin activity/ml), or corn dust extract (CDE; 0.02 microgram endotoxin activity/ml). Incubation with RsDPLA revealed a tumor necrosis factor (TNF)-alpha stimulatory effect at 100 micrograms/ml. In contrast, incubation with LPS or CDE resulted in TNF-alpha release at 0.02 microgram/ml. Pretreatment of THP-1 cells with varying concentrations of RsDPLA before incubation with LPS or CDE (0.02 microgram endotoxin activity/ml) resulted in a dose-dependent reduction in the LPS- or CDE-induced release of TNF-alpha with concentrations of RsDPLA of up to 10 micrograms/ml but not at 100 micrograms/ml. To further understand the role of endotoxin in grain dust-induced airway inflammation, we utilized the unique LPS inhibitory property of RsDPLA to determine the inflammatory response to inhaled CDE in mice in the presence of RsDPLA. Ten micrograms of RsDPLA intratracheally did not cause a significant inflammatory response compared with intratracheal saline. However, pretreatment of mice with 10 micrograms of RsDPLA intratracheally before exposure to CDE (5.4 and 0.2 micrograms/m3) or LPS (7.2 and 0.28 micrograms/m3) resulted in significant reductions in the lung lavage concentrations of total cells, neutrophils, and specific proinflammatory cytokines compared with mice pretreated with sterile saline. These results confirm the LPS

  19. Multi-PAS domain-mediated protein oligomerization of PpsR from Rhodobacter sphaeroides

    International Nuclear Information System (INIS)

    Heintz, Udo; Meinhart, Anton; Winkler, Andreas

    2014-01-01

    Crystal structures of two truncated variants of the transcription factor PpsR from R. sphaeroides are presented that enabled the phasing of a triple PAS domain construct. Together, these structures reveal the importance of α-helical PAS extensions for multi-PAS domain-mediated protein oligomerization and function. Per–ARNT–Sim (PAS) domains are essential modules of many multi-domain signalling proteins that mediate protein interaction and/or sense environmental stimuli. Frequently, multiple PAS domains are present within single polypeptide chains, where their interplay is required for protein function. Although many isolated PAS domain structures have been reported over the last decades, only a few structures of multi-PAS proteins are known. Therefore, the molecular mechanism of multi-PAS domain-mediated protein oligomerization and function is poorly understood. The transcription factor PpsR from Rhodobacter sphaeroides is such a multi-PAS domain protein that, in addition to its three PAS domains, contains a glutamine-rich linker and a C-terminal helix–turn–helix DNA-binding motif. Here, crystal structures of two N-terminally and C-terminally truncated PpsR variants that comprise a single (PpsR Q-PAS1 ) and two (PpsR N-Q-PAS1 ) PAS domains, respectively, are presented and the multi-step strategy required for the phasing of a triple PAS domain construct (PpsR ΔHTH ) is illustrated. While parts of the biologically relevant dimerization interface can already be observed in the two shorter constructs, the PpsR ΔHTH structure reveals how three PAS domains enable the formation of multiple oligomeric states (dimer, tetramer and octamer), highlighting that not only the PAS cores but also their α-helical extensions are essential for protein oligomerization. The results demonstrate that the long helical glutamine-rich linker of PpsR results from a direct fusion of the N-cap of the PAS1 domain with the C-terminal extension of the N-domain that plays an important

  20. Assembly of functional photosystem complexes in Rhodobacter sphaeroides incorporating carotenoids from the spirilloxanthin pathway

    Science.gov (United States)

    Chi, Shuang C.; Mothersole, David J.; Dilbeck, Preston; Niedzwiedzki, Dariusz M.; Zhang, Hao; Qian, Pu; Vasilev, Cvetelin; Grayson, Katie J.; Jackson, Philip J.; Martin, Elizabeth C.; Li, Ying; Holten, Dewey; Neil Hunter, C.

    2015-01-01

    Carotenoids protect the photosynthetic apparatus against harmful radicals arising from the presence of both light and oxygen. They also act as accessory pigments for harvesting solar energy, and are required for stable assembly of many light-harvesting complexes. In the phototrophic bacterium Rhodobacter (Rba.) sphaeroides phytoene desaturase (CrtI) catalyses three sequential desaturations of the colourless carotenoid phytoene, extending the number of conjugated carbon–carbon double bonds, N, from three to nine and producing the yellow carotenoid neurosporene; subsequent modifications produce the yellow/red carotenoids spheroidene/spheroidenone (N = 10/11). Genomic crtI replacements were used to swap the native three-step Rba. sphaeroides CrtI for the four-step Pantoea agglomerans enzyme, which re-routed carotenoid biosynthesis and culminated in the production of 2,2′-diketo-spirilloxanthin under semi-aerobic conditions. The new carotenoid pathway was elucidated using a combination of HPLC and mass spectrometry. Premature termination of this new pathway by inactivating crtC or crtD produced strains with lycopene or rhodopin as major carotenoids. All of the spirilloxanthin series carotenoids are accepted by the assembly pathways for LH2 and RC–LH1–PufX complexes. The efficiency of carotenoid-to-bacteriochlorophyll energy transfer for 2,2′-diketo-spirilloxanthin (15 conjugated C 000000000000 000000000000 000000000000 111111111111 000000000000 111111111111 000000000000 000000000000 000000000000 C bonds; N = 15) in LH2 complexes is low, at 35%. High energy transfer efficiencies were obtained for neurosporene (N = 9; 94%), spheroidene (N = 10; 96%) and spheroidenone (N = 11; 95%), whereas intermediate values were measured for lycopene (N = 11; 64%), rhodopin (N = 11; 62%) and spirilloxanthin (N = 13; 39%). The variety and stability of these novel Rba. sphaeroides antenna complexes make them useful experimental models for investigating the

  1. Heavy metal bioaccumulation in the soft tissues of the green mussels, Perna viridis (L.) Bivalve: Mytilacea

    International Nuclear Information System (INIS)

    Borbon, V.X.L.

    1991-01-01

    Untreated agro-industrial and domestic waste continuously being damped along the shores of its surrounding provinces and cities pollute the Manila Bay coastal waters. Presumably, its oyster and mussel culture farms are contaminated with toxic heavy metals. Yet, this alarming signs remain barely investigated. Pollution enhanced, the bioavailability and toxicity of heavy metals threaten the flora and fauna of the aquatic ecosystem. Trace concentrations of toxic elements in the marine food chain can trigger deleterious biochemical, physiological and ecological impact. Known to be bio-accumulated by aquatic organisms, the mean concentrations of Hg, Cd, Pb, Cu, and Zn in the edible tissues of Perna viridis were determined. Water and sediments sampled from the mussel culture farms were also analyzed. Results revealed that despite the apparent pollution, except for Cu and Zn, which registered slightly higher values, Hg, Cd and Pb concentrations were much lower than the maximum permissible limits. Even water and sediments samples tested showed that mean concentrations of these elements were still below sublethal limits. (auth.). 79 refs.; 8 figs.; 13 tabs.; 16 plates

  2. Kelayakan Kualitas Perairan Sekitar Mangrove Center Tuban Untuk Aplikasi Alat Pengumpul Kerang Hijau (Perna viridis L.

    Directory of Open Access Journals (Sweden)

    Syarifah Hikmah Julinda Sari

    2015-04-01

    Full Text Available The coastal waters around the Mangrove Center Tuban, East Java is a potential habitat for the green mussel (Perna viridis L.. Therefore, the water quality of this area need to be assessment. The study was aimed to determine the feasibility of water quality in coastal water f Mangrove Center Tuban for application collecting gear of green mussels. The sampling was conducted by set up three stations randomly in studied area. Parameters was measured including temperature, pH, salinity, DO, depth, turbidity, BOD and TSS. The results showed that the coastal waters around the Mangrove Center Tuban, owned temperature that ranged from 29.10 to 30.67 0C, the pH ranged from 8.23 to 8.37, salinity ranged from 26.87 to 30.30 ‰, DO fall in the range of 6,63- 6.87 mg / L, the water depth at the time of measurement ranges from 40-85 cm. TSS ranged from 206.2 mg / L to 353.7 mg / L, BOD value between 4.05 to 12.2 mg / L, while the turbidity ranged from 134 to 400 NTU. Parameters that below the standard namely temperature, pH, DO, salinity and BOD, while TSS and turbidity were exceed the threshold quality standards set by the government.

  3. Feasibility of green mussel, Perna viridis farming in Marudu Bay, Malaysia

    Directory of Open Access Journals (Sweden)

    Tan Kar Soon

    2016-11-01

    Full Text Available Bivalve aquaculture is an important source of affordable animal protein for coastal community. The success and sustainability of this industry is highly influenced by the suitability of the environment in which it is carried out. Present study was carried out to evaluate the feasibility of green mussel (Perna viridis farming in Marudu Bay. The site suitability for green mussel farming was evaluated based on biophysical parameters and food availability. The in situ environmental parameters, phytoplankton abundance and composition were collected from 10 sampling stations on monthly interval from May 2014 to April 2015. The results showed that the environmental parameters and food availability in most of the sampling stations were suitable for green mussel. However, the presence of phytoplankton taxa (Chaetoceraceae which are unfavorable by green mussel in most of the stations located at the bay pocket make those areas less recommended for green mussel farming. In contrast, stations located on the mouth of the bay exhibited high site suitability rating points and hence are highly recommended for cultivation of green mussel.

  4. Detection of Cryptosporidium oocysts in green mussels (Perna viridis from shell-fish markets of Thailand

    Directory of Open Access Journals (Sweden)

    Srisuphanunt M.

    2009-09-01

    Full Text Available Mussels filter large volumes of water and can concentrate pathogenic organisms, which may act as potential vehicles of transmission to the consumer. A survey study was carried out to investigate the presence of Cryptosporidium protozoan parasites in green mussels (Perna viridis, the smussles pecies most destined for consumption in Thailand. In total, 56 samples were examined from Bangkok (n = 24 and Samut Prakan (n = 32 a wholesale shell-fish markets located at the mouth of the Chao Phraya River. The market for green mussels was closed to the mussel culture placed along the coastal line and this localization may have significant economical impact if the mussels’ cultures are found contaminated. Cryptosporidium spp. oocysts were detected by the immunofluorescence antibody method (IFA in 12.5% of the samples examined. The detection of Cryptosporidium oocysts in green mussels’ population of Samut Prakan was higher (15.6% than in Bangkok market (8.3%. These differences in positive samples from the two locations may be caused by physical, ecological and anthropogenic conditions. This could relay to different contamination levels of marine water by Cryptosporidium oocysts and consequently to contamination of harvested shellfish populations. The results demonstrate that the Cryptosporidium spp. oocysts were found indigenous in mussels from the coastal line of Thailand, indicating that mussels may act as a reservoir of Cryptosporidium foodborne infections for humans.

  5. Oxidative stress and apoptotic events during thermal stress in the symbiotic sea anemone, Anemonia viridis.

    Science.gov (United States)

    Richier, Sophie; Sabourault, Cécile; Courtiade, Juliette; Zucchini, Nathalie; Allemand, Denis; Furla, Paola

    2006-09-01

    Symbiosis between cnidarian and photosynthetic protists is widely distributed over temperate and tropical seas. These symbioses can periodically breakdown, a phenomenon known as cnidarian bleaching. This event can be irreversible for some associations subjected to acute and/or prolonged environmental disturbances, and leads to the death of the animal host. During bleaching, oxidative stress has been described previously as acting at molecular level and apoptosis is suggested to be one of the mechanisms involved. We focused our study on the role of apoptosis in bleaching via oxidative stress in the association between the sea anemone Anemonia viridis and the dinoflagellates Symbiodinium species. Characterization of caspase-like enzymes were conducted at the biochemical and molecular level to confirm the presence of a caspase-dependent apoptotic phenomenon in the cnidarian host. We provide evidence of oxidative stress followed by induction of caspase-like activity in animal host cells after an elevated temperature stress, suggesting the concomitant action of these components in bleaching.

  6. Detection of Cryptosporidium oocysts in green mussels (Perna viridis) from shell-fish markets of Thailand.

    Science.gov (United States)

    Srisuphanunt, M; Wiwanitkit, Viroj; Saksirisampant, W; Karanis, P

    2009-09-01

    Mussels filter large volumes of water and can concentrate pathogenic organisms, which may act as potential vehicles of transmission to the consumer. A survey study was carried out to investigate the presence of Cryptosporidium protozoan parasites in green mussels (Perna viridis), the smussles pecies most destined for consumption in Thailand. In total, 56 samples were examined from Bangkok (n = 24) and Samut Prakan (n = 32) a wholesale shell-fish markets located at the mouth of the Chao Phraya River. The market for green mussels was closed to the mussel culture placed along the coastal line and this localization may have significant economical impact if the mussels' cultures are found contaminated. Cryptosporidium spp. oocysts were detected by the immunofluorescence antibody method (IFA) in 12.5% of the samples examined. The detection of Cryptosporidium oocysts in green mussels' population of Samut Prakan was higher (15.6%) than in Bangkok market (8.3%). These differences in positive samples from the two locations may be caused by physical, ecological and anthropogenic conditions. This could relay to different contamination levels of marine water by Cryptosporidium oocysts and consequently to contamination of harvested shellfish populations. The results demonstrate that the Cryptosporidium spp. oocysts were found indigenous in mussels from the coastal line of Thailand, indicating that mussels may act as a reservoir of Cryptosporidium foodborne infections for humans.

  7. Phytolith analysis for differentiating between foxtail millet (Setaria italica) and green foxtail (Setaria viridis).

    Science.gov (United States)

    Zhang, Jianping; Lu, Houyuan; Wu, Naiqin; Yang, Xiaoyan; Diao, Xianmin

    2011-05-06

    Foxtail millet (Setaria italica) is one of the oldest domesticated cereal crops in Eurasia, but identifying foxtail millets, especially in charred grains, and differentiating it from its wild ancestor, green foxtail (Setaria viridis), in the archaeobotanical remains, is still problematic. Phytolithic analysis provides a meaningful method for identifying this important crop. In this paper, the silicon structure patterns in the glumes, lemmas, and paleas from inflorescence bracts in 16 modern plants of foxtail millet and green foxtail from China and Europe are examined using light microscopy with phase-contrast and a microscopic interferometer. Our research shows that the silicon structure of ΩIII from upper lemmas and paleas in foxtail millet and green foxtail can be correspondingly divided into two groups. The size of ΩIII type phytolith of foxtail millet is bigger than that from green foxtail. Discriminant function analysis reveals that 78.4% of data on foxtail millet and 76.9% of data on green foxtail are correctly classified. This means certain morphotypes of phytoliths are relatively reliable tools for distinguishing foxtail millet from green foxtail. Our results also revealed that the husk phytolith morphologies of foxtail millets from China and Eastern Europe are markedly different from those from Western Europe. Our research gives a meaningful method of separating foxtail millet and green foxtail. The implications of these findings for understanding the history of foxtail millet domestication and cultivation in ancient civilizations are significant.

  8. Phytolith analysis for differentiating between foxtail millet (Setaria italica and green foxtail (Setaria viridis.

    Directory of Open Access Journals (Sweden)

    Jianping Zhang

    2011-05-01

    Full Text Available Foxtail millet (Setaria italica is one of the oldest domesticated cereal crops in Eurasia, but identifying foxtail millets, especially in charred grains, and differentiating it from its wild ancestor, green foxtail (Setaria viridis, in the archaeobotanical remains, is still problematic. Phytolithic analysis provides a meaningful method for identifying this important crop. In this paper, the silicon structure patterns in the glumes, lemmas, and paleas from inflorescence bracts in 16 modern plants of foxtail millet and green foxtail from China and Europe are examined using light microscopy with phase-contrast and a microscopic interferometer. Our research shows that the silicon structure of ΩIII from upper lemmas and paleas in foxtail millet and green foxtail can be correspondingly divided into two groups. The size of ΩIII type phytolith of foxtail millet is bigger than that from green foxtail. Discriminant function analysis reveals that 78.4% of data on foxtail millet and 76.9% of data on green foxtail are correctly classified. This means certain morphotypes of phytoliths are relatively reliable tools for distinguishing foxtail millet from green foxtail. Our results also revealed that the husk phytolith morphologies of foxtail millets from China and Eastern Europe are markedly different from those from Western Europe. Our research gives a meaningful method of separating foxtail millet and green foxtail. The implications of these findings for understanding the history of foxtail millet domestication and cultivation in ancient civilizations are significant.

  9. Life History of the Camelthorn Gall Leafhopper, Scenergates viridis (Vilbaste (Hemiptera, Cicadellidae

    Directory of Open Access Journals (Sweden)

    Roman Rakitov

    2012-01-01

    Full Text Available The world’s only member of Hemiptera Auchenorrhyncha known to form true galls, the leafhopper Scenergates viridis (Vilbaste (Cicadellidae, transforms leaves of camelthorn (Alhagi maurorum Medikus, Fabaceae into pod-like chambers, up to 35 mm long, inside which individual leafhoppers develop, mate, and lay eggs. At the study site 40 km SE of Bukhara (Uzbekistan, two generations develop annually. First-instar nymphs cause young leaves to fold along the midrib. The subsequent development takes place inside the tightly closed growing gall, plugged at both ends with a mixture of leafhopper excrement, brochosomes, and crushed exuviae. These plugs act as mechanical barriers and sticky traps for intruders. The inner surface of the gall, lined with brochosomes and wax platelets, is hydrophobic. Adult males emerge from their galls and squeeze into female galls. Fertilized females insert an average of 146 eggs under the gall’s inner epidermis and remain inside, possibly protecting the brood, until they die. The walls of the galls containing eggs are approximately three times thicker than regular leaves. The galls are subject to predation by Gelechiidae caterpillars; the eggs of the leafhopper are parasitized by two species of Trichogrammatidae and one Mymaridae (Hymenoptera, and its larvae by one species of Pipunculidae (Diptera.

  10. Dioxin and phthalate uptake and assimilation by the green mussel Perna viridis

    International Nuclear Information System (INIS)

    Wang, Wen-Xiong; Zhang, Qiong

    2013-01-01

    In this study, the aqueous uptake and dietary assimilation (trophic transfer) of two endocrine disrupting compounds (dioxin and phathalic acid) in the green mussel Perna viridis were quantified. During short-term exposure period, dioxin rapidly sorbed onto phytoplankton and its accumulation was much higher than that of phthalate. The uptake of these two compounds by the mussels increased with increasing temperature and salinity (for dioxin only). The dietary assimilation of the two contaminants was rather modest (10–64% for dioxin and 20–47% for phthalate), and was greatly dependent on the food species and concentration. Interestingly, dietary assimilation increased with increasing diatom food concentration. Gut passage time was partially responsible for the variable dietary assimilation. Given the high dissolved uptake rate and the modest dietary assimilation, aqueous exposure was predicted to be the dominant bioaccumulation source for both dioxin and phthalate in the green mussels under most conditions. -- Capsule: Aqueous uptake was the predominant pathway for dioxin and phthalate accumulation in marine green mussels

  11. Establishing the thermal threshold of the tropical mussel Perna viridis in the face of global warming.

    Science.gov (United States)

    Goh, B P L; Lai, C H

    2014-08-30

    With increasing recognition that maximum oxygen demand is the unifying limit in tolerance, the first line of thermal sensitivity is, as a corollary, due to capacity limitations at a high level of organisational complexity before individual, molecular or membrane functions become disturbed. In this study the tropical mussel Perna viridis were subjected to temperature change of 0.4 °C per hour from ambient to 8-36 °C. By comparing thermal mortality against biochemical indices (hsp70, gluthathione), physiological indices (glycogen, FRAP, NRRT) and behavioural indices (clearance rate), a hierarchy of thermal tolerance was therein elucidated, ranging from systemic to cellular to molecular levels. Generally, while biochemical indices indicated a stress signal much earlier than the more integrated behavioural indices, failure of the latter (indicating a tolerance limit and transition to pejus state) occurred much earlier than the other indices tending towards thermal extremities at both ends of the thermal spectrum. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Inter-population thermal variability and physiological response in the intertidal fish Scartichthys viridis (Blenniidae Variabilidad térmica intrapoblacional y respuesta fisiológica en el pez intermareal Scartichthys viridis (Blenniidae

    Directory of Open Access Journals (Sweden)

    JOSÉ M PULGAR

    2007-12-01

    Full Text Available Determining habitat conditions that generate individual physiological variability represents key basic knowledge to understand the direction of animal's responses to habitat change. The coastal fish Scartichthys viridis inhabits low intertidal pools along the Chilean coast. Because seawater in the low intertidal is renewed during every tidal cycle, this zone is characterized by a low thermal variation and abundant food within and between localities. We evaluated whether seawater thermal conditions and food availability of low intertidal pools registered in three localities of Chilean coast are sufficient to generate physiological and energetic differences in individuals of S. viridis captured from three geographic separate populations spanning approximately 1,200 km. Southern fishes acclimatized to 25 °C showed higher metabolic rates than those from other localities and thermal treatments. On the other hand, southern fishes in natural conditions showed higher condition factor than northern fishes. This evidence is sufficient to indicate that slight latitudinal differences in tidepool seawater temperature associated to differential food availability induced an energetic constraint in this species. Moreover, southern population of S. viridis may suffer important effects on energetic allocation if seawater temperature increases slightly, with repercussions on its geographic distribution in southern Pacific OceanDeterminar las condiciones del ambiente que generan variabilidad fisiológica, representa un conocimiento básico para comprender el sentido de la respuesta de los animales a los cambios en su habitat. El pez costero Scartichthys viridis habita las pozas bajas del intermareal a lo largo de la costa chilena. Debido a que el agua de mar se renueva en cada ciclo de marea en las pozas bajas, esta zona está caracterizada por una baja variación térmica y abundante alimento entre localidades. Nosotros evaluamos si las condiciones térmicas y la

  13. Transient absorption study of two-photon excitation mechanism in the LH2 complex from purple bacterium Rhodobacter sphaeroides.

    Science.gov (United States)

    Stepanenko, Ilya; Kompanetz, Viktor; Makhneva, Zoya; Chekalin, Sergey; Moskalenko, Andrei; Razjivin, Andrei

    2012-03-08

    The mechanism of two-photon excitation of a peripheral light-harvesting complex LH2 (B800-850) from purple bacterium Rhodobacter sphaeroides was explained on the basis of femtosecond transient absorption data. Fast bleaching of the B850 absorption band was measured under two-photon excitation by 1350 nm femtosecond pulses, showing fast subpicosecond arrival of excitation energy to B850 circular aggregates. Any spectral changes connected with the B800 absorption band of B800-BChl molecules were absent. A similar picture was observed under one-photon excitation of the LH2 complex by 675 nm femtosecond pulses. We believe these effects may be attributed to direct excitation of high-energy excitonic states of a B850 circular aggregate or its vibrational manifold in accordance with the model of Abe [Chem. Phys. 2001, 264, 355-363].

  14. Characterization of D-tagatose-3-epimerase from Rhodobacter sphaeroides that converts D-fructose into D-psicose.

    Science.gov (United States)

    Zhang, Longtao; Mu, Wanmeng; Jiang, Bo; Zhang, Tao

    2009-06-01

    A non-characterized gene, previously proposed as the D-tagatose-3-epimerase gene from Rhodobacter sphaeroides, was cloned and expressed in Escherichia coli. Its molecular mass was estimated to be 64 kDa with two identical subunits. The enzyme specificity was highest with D-fructose and decreased for other substrates in the order: D-tagatose, D-psicose, D-ribulose, D-xylulose and D-sorbose. Its activity was maximal at pH 9 and 40 degrees C while being enhanced by Mn(2+). At pH 9 and 40 degrees C, 118 g D-psicose l(-1) was produced from 700 g D-fructose l(-1) after 3 h.

  15. Mathematical model for the analytical signal of an herbicide sensor based on the reaction centre of Rhodobacter sphaeroides.

    Science.gov (United States)

    Andreu, Yolanda; Baldini, Francesco; Giannetti, Ambra; Mencaglia, Andrea

    2005-01-30

    This paper introduces a mathematical model which makes it possible both to determine the concentration of photosynthetic herbicides and to obtain a quantitative parameter in order to compare their activity using a previously described sensing system. The working principle involves the changes in absorption properties at 860nm of the reaction centre (RC) isolated from the bacteria Rhodobacter sphaeroides when photosynthetic herbicides are present. The method has been used for the determination and activity comparison of five photosynthetic herbicides: diuron, atrazine, terbutryn, terbuthylazine and simazine. Detection limits obtained were 2.2, 0.75, 0.046, 0.25, and 1.4muM, respectively. The resulting order for the different herbicides according to their action on RC was: terbutryn > terbuthylazine > atrazine > simazine > diuron.

  16. Characterization of small HSPs from Anemonia viridis reveals insights into molecular evolution of alpha crystallin genes among cnidarians.

    Directory of Open Access Journals (Sweden)

    Aldo Nicosia

    Full Text Available Gene family encoding small Heat-Shock Proteins (sHSPs containing α-crystallin domain are found both in prokaryotic and eukaryotic organisms; however, there is limited knowledge of their evolution. In this study, two small HSP genes termed AvHSP28.6 and AvHSP27, both organized in one intron and two exons, were characterised in the Mediterranean snakelocks anemone Anemonia viridis. The release of the genome sequence of Hydra magnipapillata and Nematostella vectensis enabled a comprehensive study of the molecular evolution of α-crystallin gene family among cnidarians. Most of the H. magnipapillata sHSP genes share the same gene organization described for AvHSP28.6 and AvHSP27, differing from the sHSP genes of N. vectensis which mainly show an intronless architecture. The different genomic organization of sHSPs, the phylogenetic analyses based on protein sequences, and the relationships among Cnidarians, suggest that the A.viridis sHSPs represent the common ancestor from which H. magnipapillata genes directly evolved through segmental genome duplication. Additionally retroposition events may be considered responsible for the divergence of sHSP genes of N. vectensis from A. viridis. Analyses of transcriptional expression profile showed that AvHSP28.6 was constitutively expressed among different tissues from both ectodermal and endodermal layers of the adult sea anemones, under normal physiological conditions and also under different stress condition. Specifically, we profiled the transcriptional activation of AvHSP28.6 after challenges with different abiotic/biotic stresses showing induction by extreme temperatures, heavy metals exposure and immune stimulation. Conversely, no AvHSP27 transcript was detected in such dissected tissues, in adult whole body cDNA library or under stress conditions. Hence, the involvement of AvHSP28.6 gene in the sea anemone defensome is strongly suggested.

  17. Effects of Sodium Nitrate and Mixotrophic Culture on Biomass and Lipid Production in Hypersaline Microalgae Dunaliella Viridis Teod

    Directory of Open Access Journals (Sweden)

    Mansour Kharati-Koupaei

    Full Text Available To access the potential application of Dunaliella viridis Teod. for biofuel production, the effects of culture media composition on biomass and lipid content of this microalgae were investigated. Measured at the 20 th day, sodium nitrate at 5.0 mM augmented biomass production by 26.5 percent compared to control (1 mM sodium nitrate. Total lipids expressed as µg mL-1 of culture also increased with increase in nitrate concentration up to 5.0 mM sodium nitrate, whereas when expressed on the per cell basis, total lipids stayed relatively constant at most of the tested nitrate concentrations except at 0.5 mM which was 31.4 percent higher compared to 1.0 mM nitrate. At 5.0 mM sodium nitrate, by using 20 g L-1 of glucose in mixotrophic culture of D. viridis, cell number augmented by 36.4 percent compared to the cultures with no added glucose. Llipid content per cell and per mL of culture was increased by 71.4 and 135.1 percent, respectively. Among plant hormones, 10-9 M indole-3- acetic acid (IAA plus 10 -8 M trans-zeatin riboside led to 22.8 percent higher biomass relative to control (without hormone and at 1.0 mM sodium nitrate. It is concluded that altering the growth conditions of D. viridis can lead to higher cell densities and higher lipids content which can be exploited for biofuel production.

  18. Characterization of small HSPs from Anemonia viridis reveals insights into molecular evolution of alpha crystallin genes among cnidarians.

    Science.gov (United States)

    Nicosia, Aldo; Maggio, Teresa; Mazzola, Salvatore; Gianguzza, Fabrizio; Cuttitta, Angela; Costa, Salvatore

    2014-01-01

    Gene family encoding small Heat-Shock Proteins (sHSPs containing α-crystallin domain) are found both in prokaryotic and eukaryotic organisms; however, there is limited knowledge of their evolution. In this study, two small HSP genes termed AvHSP28.6 and AvHSP27, both organized in one intron and two exons, were characterised in the Mediterranean snakelocks anemone Anemonia viridis. The release of the genome sequence of Hydra magnipapillata and Nematostella vectensis enabled a comprehensive study of the molecular evolution of α-crystallin gene family among cnidarians. Most of the H. magnipapillata sHSP genes share the same gene organization described for AvHSP28.6 and AvHSP27, differing from the sHSP genes of N. vectensis which mainly show an intronless architecture. The different genomic organization of sHSPs, the phylogenetic analyses based on protein sequences, and the relationships among Cnidarians, suggest that the A.viridis sHSPs represent the common ancestor from which H. magnipapillata genes directly evolved through segmental genome duplication. Additionally retroposition events may be considered responsible for the divergence of sHSP genes of N. vectensis from A. viridis. Analyses of transcriptional expression profile showed that AvHSP28.6 was constitutively expressed among different tissues from both ectodermal and endodermal layers of the adult sea anemones, under normal physiological conditions and also under different stress condition. Specifically, we profiled the transcriptional activation of AvHSP28.6 after challenges with different abiotic/biotic stresses showing induction by extreme temperatures, heavy metals exposure and immune stimulation. Conversely, no AvHSP27 transcript was detected in such dissected tissues, in adult whole body cDNA library or under stress conditions. Hence, the involvement of AvHSP28.6 gene in the sea anemone defensome is strongly suggested.

  19. Environment-dependence of behavioural consistency in adult male European green lizards (Lacerta viridis).

    Science.gov (United States)

    Horváth, Gergely; Mészáros, Boglárka; Urszán, Tamás János; Bajer, Katalin; Molnár, Orsolya; Garamszegi, László Zsolt; Herczeg, Gábor

    2017-01-01

    Understanding the background mechanisms affecting the emergence and maintenance of consistent between-individual variation within population in single (animal personality) or across multiple (behavioural syndrome) behaviours has key importance. State-dependence theory suggests that behaviour is 'anchored' to individual state (e.g. body condition, gender, age) and behavioural consistency emerges through behavioural-state feedbacks. A number of relevant state variables are labile (e.g. body condition, physiological performance) and expected to be affected by short-term environmental change. Yet, whether short-term environmental shifts affect behavioural consistency during adulthood remains questionable. Here, by employing a full-factorial laboratory experiment, we explored if quantity of food (low vs. high) and time available for thermoregulation (3h vs. 10h per day) had an effect on activity and risk-taking of reproductive adult male European green lizards (Lacerta viridis). We focussed on different components of behavioural variation: (i) strength of behavioural consistency (repeatability for animal personality; between-individual correlation for behavioural syndrome), (ii) behavioural type (individual mean behaviour) and (iii) behavioural predictability (within-individual behavioural variation). Activity was repeatable in all treatments. Risk-taking was repeatable only in the low basking treatments. We found significant between-individual correlation only in the low food × long basking time group. The treatments did not affect behavioural type, but affected behavioural predictability. Activity predictability was higher in the short basking treatment, where it also decreased with size (≈ age). Risk-taking predictability in the short basking treatment increased with size under food limitation, but decreased when food supply was high. We conclude that short-term environmental change can alter various components of behavioural consistency. The effect could be

  20. Molar extinction coefficients and other properties of an improved reaction center preparation from Rhodopseudomonas viridis

    Energy Technology Data Exchange (ETDEWEB)

    Clayton, R.K.; Clayton, B.J.

    1978-01-01

    Reaction centers have been purified from chromatophores of Rhodopseudomonas viridis by treatment with lauryl dimethyl amine oxide followed by hydroxyapatite chromatography and precipitation with ammonium sulfate. The absorption spectrum at low temperature shows bands at 531 and 543 nm, assigned to two molecules of bacteriopheophytin b. The 600 nm band of bacteriochlorophyll b is resolved at low temperature into components at 601 and 606.5 nm. At room temperature the light-induced difference spectrum shows a negative band centered at 615 nm, where the absorption spectrum shows only a week shoulder adjacent to the 600 nm band. The fluorescence spectrum shows a band at 1000 nm and no fluorescence corresponding to the 830 nm absorption band. Two molecules of cytochrome 558 and three of cytochrome 552 accompany each reaction center. The differential extinction coefficient (reduced minus oxidized) of cytochrome 558 nm was estimated as 20 +- 2 mM/sup -1/.cm/sup -1/ through a coupled reaction with equine cytochrome c. The extinction coefficient of reaction centers at 960 nm was determined to be 123 +- 25 mM/sup -1/.cm/sup -1/ by measuring the light-induced bleaching of P-960 and the coupled oxidation of cytochrome 558. The corresponding extinction coefficient at 830 nm is 300 +- 65 mM/sup -1/.cm/sup -1/. The absorbance ratio ..cap alpha../sub 280nm/..cap alpha../sub 830nm/ in our preparations was 2.1, and there was 190 kg protein per mol of reaction centers. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed three major components of apparent molecular weights 31,000, 37,000, and 41,000.

  1. Functional polarity of the tentacle of the sea anemone Anemonia viridis: role in inorganic carbon acquisition.

    Science.gov (United States)

    Furla, P; Bénazet-Tambutté, S; Jaubert, J; Allemand, D

    1998-02-01

    The oral epithelial layers of anthozoans have a polarized morphology: photosynthetic endosymbionts live within endodermal cells facing the coelenteric cavity and are separated from the external seawater by the ectodermal layer and the mesoglea. To study if this morphology plays a role in the supply of inorganic carbon for symbiont photosynthesis, we measured the change in pH and the rate of OH- (H+) fluxes induced by each cell layer on a tentacle of the sea anemone Anemonia viridis. Light-induced pH increase of the medium bathing the endodermal layers led to the generation of a transepithelial pH gradient of approximately 0.8 pH units across the tentacle, whereas darkness induced acidification of this medium. The light-induced pH change was associated with an increase of total alkalinity. Only the endodermal layer was able to induce a net OH- secretion (H+ absorption). The light-induced OH- secretion by the endodermal cell layer was dependent on the presence of HCO3- in the compartment facing the ectoderm and was sensitive to several inhibitors of ion transport. [14C] HCO3- incorporation into photosynthates confirmed the ectodermal supply, the extent of which varied from 25 to > 90%, according to HCO3- availability. Our results suggest that the light-induced OH- secretion by the endodermal cell layer followed the polarized transport of HCO3- and its subsequent decarboxylation within the endodermal cell layer. This polarity may play a significant role both in inorganic carbon absorption and in the control of light-enhanced calcification in scleractinian corals.

  2. Regulation of intracellular pH in cnidarians: response to acidosis in Anemonia viridis.

    Science.gov (United States)

    Laurent, Julien; Venn, Alexander; Tambutté, Éric; Ganot, Philippe; Allemand, Denis; Tambutté, Sylvie

    2014-02-01

    The regulation of intracellular pH (pHi) is a fundamental aspect of cell physiology that has received little attention in studies of the phylum Cnidaria, which includes ecologically important sea anemones and reef-building corals. Like all organisms, cnidarians must maintain pH homeostasis to counterbalance reductions in pHi, which can arise because of changes in either intrinsic or extrinsic parameters. Corals and sea anemones face natural daily changes in internal fluids, where the extracellular pH can range from 8.9 during the day to 7.4 at night. Furthermore, cnidarians are likely to experience future CO₂-driven declines in seawater pH, a process known as ocean acidification. Here, we carried out the first mechanistic investigation to determine how cnidarian pHi regulation responds to decreases in extracellular and intracellular pH. Using the anemone Anemonia viridis, we employed confocal live cell imaging and a pH-sensitive dye to track the dynamics of pHi after intracellular acidosis induced by acute exposure to decreases in seawater pH and NH₄Cl prepulses. The investigation was conducted on cells that contained intracellular symbiotic algae (Symbiodinium sp.) and on symbiont-free endoderm cells. Experiments using inhibitors and Na⁺-free seawater indicate a potential role of Na⁺/H⁺ plasma membrane exchangers (NHEs) in mediating pHi recovery following intracellular acidosis in both cell types. We also measured the buffering capacity of cells, and obtained values between 20.8 and 43.8 mM per pH unit, which are comparable to those in other invertebrates. Our findings provide the first steps towards a better understanding of acid-base regulation in these basal metazoans, for which information on cell physiology is extremely limited. © 2013 FEBS.

  3. Differential distribution of lipids in epidermis, gastrodermis and hosted Symbiodinium in the sea anemone Anemonia viridis.

    Science.gov (United States)

    Revel, Johana; Massi, Lionel; Mehiri, Mohamed; Boutoute, Marc; Mayzaud, Patrick; Capron, Laure; Sabourault, Cécile

    2016-01-01

    Cnidarian-dinoflagellate symbiosis mainly relies on nutrient recycling, thus providing both partners with a competitive advantage in nutrient-poor waters. Essential processes related to lipid metabolism can be influenced by various factors, including hyperthermal stress. This can affect the lipid content and distribution in both partners, while contributing to symbiosis disruption and bleaching. In order to gain further insight into the role and distribution of lipids in the cnidarian metabolism, we investigated the lipid composition of the sea anemone Anemonia viridis and its photosynthetic dinoflagellate endosymbionts (Symbiodinium). We compared the lipid content and fatty acid profiles of the host cellular layers, non-symbiotic epidermal and symbiont-containing gastrodermal cells, and those of Symbiodinium, in a mass spectrometry-based assessment. Lipids were more concentrated in Symbiodinium cells, and the lipid class distribution was dominated by polar lipids in all tissues. The fatty acid distribution between host cell layers and Symbiodinium cells suggested potential lipid transfers between the partners. The lipid composition and distribution was modified during short-term hyperthermal stress, mainly in Symbiodinium cells and gastrodermis. Exposure to elevated temperature rapidly caused a decrease in polar lipid C18 unsaturated fatty acids and a strong and rapid decrease in the abundance of polar lipid fatty acids relative to sterols. These lipid indicators could therefore be used as sensitive biomarkers to assess the physiology of symbiotic cnidarians, especially the effect of thermal stress at the onset of cnidarian bleaching. Overall, the findings of this study provide some insight on key lipids that may regulate maintenance of the symbiotic interaction. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Environment-dependence of behavioural consistency in adult male European green lizards (Lacerta viridis.

    Directory of Open Access Journals (Sweden)

    Gergely Horváth

    Full Text Available Understanding the background mechanisms affecting the emergence and maintenance of consistent between-individual variation within population in single (animal personality or across multiple (behavioural syndrome behaviours has key importance. State-dependence theory suggests that behaviour is 'anchored' to individual state (e.g. body condition, gender, age and behavioural consistency emerges through behavioural-state feedbacks. A number of relevant state variables are labile (e.g. body condition, physiological performance and expected to be affected by short-term environmental change. Yet, whether short-term environmental shifts affect behavioural consistency during adulthood remains questionable. Here, by employing a full-factorial laboratory experiment, we explored if quantity of food (low vs. high and time available for thermoregulation (3h vs. 10h per day had an effect on activity and risk-taking of reproductive adult male European green lizards (Lacerta viridis. We focussed on different components of behavioural variation: (i strength of behavioural consistency (repeatability for animal personality; between-individual correlation for behavioural syndrome, (ii behavioural type (individual mean behaviour and (iii behavioural predictability (within-individual behavioural variation. Activity was repeatable in all treatments. Risk-taking was repeatable only in the low basking treatments. We found significant between-individual correlation only in the low food × long basking time group. The treatments did not affect behavioural type, but affected behavioural predictability. Activity predictability was higher in the short basking treatment, where it also decreased with size (≈ age. Risk-taking predictability in the short basking treatment increased with size under food limitation, but decreased when food supply was high. We conclude that short-term environmental change can alter various components of behavioural consistency. The effect could be

  5. Environment-dependence of behavioural consistency in adult male European green lizards (Lacerta viridis)

    Science.gov (United States)

    Urszán, Tamás János; Bajer, Katalin; Molnár, Orsolya; Garamszegi, László Zsolt; Herczeg, Gábor

    2017-01-01

    Understanding the background mechanisms affecting the emergence and maintenance of consistent between-individual variation within population in single (animal personality) or across multiple (behavioural syndrome) behaviours has key importance. State-dependence theory suggests that behaviour is ‘anchored’ to individual state (e.g. body condition, gender, age) and behavioural consistency emerges through behavioural-state feedbacks. A number of relevant state variables are labile (e.g. body condition, physiological performance) and expected to be affected by short-term environmental change. Yet, whether short-term environmental shifts affect behavioural consistency during adulthood remains questionable. Here, by employing a full-factorial laboratory experiment, we explored if quantity of food (low vs. high) and time available for thermoregulation (3h vs. 10h per day) had an effect on activity and risk-taking of reproductive adult male European green lizards (Lacerta viridis). We focussed on different components of behavioural variation: (i) strength of behavioural consistency (repeatability for animal personality; between-individual correlation for behavioural syndrome), (ii) behavioural type (individual mean behaviour) and (iii) behavioural predictability (within-individual behavioural variation). Activity was repeatable in all treatments. Risk-taking was repeatable only in the low basking treatments. We found significant between-individual correlation only in the low food × long basking time group. The treatments did not affect behavioural type, but affected behavioural predictability. Activity predictability was higher in the short basking treatment, where it also decreased with size (≈ age). Risk-taking predictability in the short basking treatment increased with size under food limitation, but decreased when food supply was high. We conclude that short-term environmental change can alter various components of behavioural consistency. The effect could be

  6. Reactions of green lizards (Lacerta viridis) to major repellent compounds secreted by Graphosoma lineatum (Heteroptera: Pentatomidae).

    Science.gov (United States)

    Gregorovičová, Martina; Černíková, Alena

    2015-06-01

    The chemical defence of Heteroptera is primarily based on repellent secretions which signal the potential toxicity of the bug to its predators. We tested the aversive reactions of green lizards (Lacerta viridis) towards the major compounds of the defensive secretion of Graphosoma lineatum, specifically: (i) a mixture of three aldehydes: (E)-hex-2-enal, (E)-oct-2-enal, (E)-dec-2-enal; (ii) a mixture of these three aldehydes and tridecane; (iii) oxoaldehyde: (E)-4-oxohex-2-enal; (iv) secretion extracted from metathoracic scent glands of G. lineatum adults and (v) hexane as a non-polar solvent. All chemicals were presented on a palatable food (Tenebrio molitor larvae). The aversive reactions of the green lizards towards the mealworms were evaluated by observing the approach latencies, attack latencies and approach-attack intervals. The green lizards exhibited a strong aversive reaction to the mixture of three aldehydes. Tridecane reduced the aversive reaction to the aldehyde mixture. Oxoaldehyde caused the weakest, but still significant, aversive reaction. The secretion from whole metathoracic scent glands also clearly had an aversive effect on the green lizards. Moreover, when a living specimen of G. lineatum or Pyrrhocoris apterus (another aposematic red-and-black prey) was presented to the green lizards before the trials with the aldehyde mixture, the aversive effect of the mixture was enhanced. In conclusion, the mixture of three aldehydes had the strong aversive effect and could signal the potential toxicity of G. lineatum to the green lizards. Copyright © 2015 Elsevier GmbH. All rights reserved.

  7. Development of fibre and parenchyma cells in the bamboo Phyllostachys viridi-glaucescens

    International Nuclear Information System (INIS)

    Crow, E.

    2000-02-01

    The development of the shoot apex and the ontogeny of fibre and parenchyma cells in elongating shoots of the bamboo Phyllostachys viridi-glaucescens (Carr.) Riv. and Riv., seen under the light microscope is described. Fibre cells differentiated from cells of the procambium, whilst the parenchyma cells differentiated from cells of the primary thickening meristem which surround the procambium strands. Three stages of early fibre and parenchyma cell development were identified and these are referred to in subsequent studies of cell wall development. The cytology of developing internodal fibre and parenchyma cells seen under the transmission electron microscope (TEM) is described. There were few ultrastructural features to distinguish the two cell types. Thiery's PATAg test was performed to identify organelles which may be associated with the synthesis of polysaccharides destined for the cell wall. The ultrastructural results are discussed in terms of the process of cell wall deposition. Observations were made of cytoskeletal elements using indirect immunofluorescence techniques. Orientations of cortical microtubules differed from those of the microfilaments throughout early development. Filaments on the inner walls of cells seen under the conventional scanning electron microscope (SEM) were cytoskeletal-like in their orientation and form. Immunogold labelling techniques were performed in an attempt to confirm their identity. Staining with safranin and alcian blue allowed an anatomical description of wall development in fibre and parenchyma cells. These studies were coupled with observations using polarizing optics where cellulose microfibril orientations of the primary and secondary wall layers were established. The field emission scanning electron microscope (FESEM) was used to describe microfibril orientations seen on the inner wall of developing and maturing fibre and parenchyma cells. Chemical extraction of wall matrix materials was necessary for maturing tissue

  8. Behavioural and neurotoxic effects of ayahuasca infusion (Banisteriopsis caapi and Psychotria viridis) in female Wistar rat.

    Science.gov (United States)

    Pic-Taylor, Aline; da Motta, Luciana Gueiros; de Morais, Juliana Alves; Junior, Willian Melo; Santos, Alana de Fátima Andrade; Campos, Leandro Ambrósio; Mortari, Marcia Renata; von Zuben, Marcus Vinicius; Caldas, Eloisa Dutra

    2015-09-01

    Ayahuasca, a psychoactive beverage used by indigenous and religious groups, is generally prepared by the coction of Psychotria viridis and Banisteriopsis caapi plants containing N,N-dimethyltryptamine (DMT) and β-carboline alkaloids, respectively. To investigate the acute toxicity of ayahuasca, the infusion was administered by gavage to female Wistar rats at doses of 30X and 50X the dose taken during a religious ritual, and the animals observed for 14 days. Behavioural functions were investigated one hour after dosing at 15X and 30X using the open field, elevated plus maze, and forced swimming tests. Neuronal activation (c-fos marked neurons) and toxicity (Fluoro-Jade B and Nissl/Cresyl staining) were investigated in the dorsal raphe nuclei (DRN), amygdaloid nucleus, and hippocampal formation brain areas of rats treated with a 30X ayahuasca dose. The actual lethal oral dose in female Wistar rats could not be determined in this study, but was shown to be higher than the 50X (which corresponds to 15.1mg/kg bw DMT). The ayahuasca and fluoxetine treated groups showed a significant decrease in locomotion in the open field and elevated plus-maze tests compared to controls. In the forced swimming test, ayahuasca treated animals swam more than controls, a behaviour that was not significant in the fluoxetine group. Treated animals showed higher neuronal activation in all brain areas involved in serotoninergic neurotransmission. Although this led to some brain injury, no permanent damage was detected. These results suggest that ayahuasca has antidepressant properties in Wistar female at high doses, an effect that should be further investigated. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Biological Carbon Dioxide Assimilation Process Using Marine Phytoplankton Tetraselmis suecica and Bivalve Perna viridis

    Directory of Open Access Journals (Sweden)

    Sirichai Dharmvanij

    2012-01-01

    Full Text Available The Biological CO2 assimilation process using marine phytoplankton and marine bivalve was evaluated by carbon assimilation of the green mussel Perna viridis fed with Tetraselmis suecica under laboratory condition. Incorporation of carbon dioxide into phytoplankton biomass was performed through aeration. The experiment consisted of three treatments i.e. mussels without feeding (Control, mussels fed with T. suecica cultured with air (Treatment 1: T-Air, and mussels fed with T. suecica cultured with 1.5% CO2 in air (Treatment 2: T-CO2. The results showed that growth of mussels in T-Air and T-CO2 was 22.4 ± 4.0 mg/individual/day and 28.9 ± 12.3 mg/individual/day, respectively, which was significantly higher than control (mussels without feeding. Growth of mussels in T-Air was significantly lower than in T-CO2. Carbon content in shell (15.59 ± 0.57 % D.W. and meat (38.28 ± 1.72 % D.W. of mussels fed with aerated T. suecica (T-Air was significantly higher than that found in mussels fed with 1.5% CO2 T. suecica (14.2 ± 0.47 and 36.61± 0.43 % D.W. in shell and in meat, respectively (p≤0.05. With T-Air, 1.95±0.27 and 9.36±1.24% of carbon from T. suecica cells was assimilated into shell and meat of the mussel, respectively, while in T-CO2 , carbon assimilation from T. suecica cells in shell and meat was 2.19±0.55 and 11.22±2.76% respectively.

  10. Mortalities of the Green Toad (Epidalea viridis (Laurenti, 1768 in Urban Environment: A Case Study from the City of Plovdiv

    Directory of Open Access Journals (Sweden)

    Miglena V. Valkanova

    2009-08-01

    Full Text Available The current study analyzes the types of mortalities of the green toad (Epidalea viridis in the city of Plovdiv. Among all recorded mortalities (n=42, the road kill was the most common cause of death (65 % of the cases, followed by killing by humans (usually children – 31%. Killing of green toads by dogs (2% and domestic cats (2% has the lowest impact. Both most significant factors (road kill and killing by humans affect mainly the adult specimens. No statistically significant difference between the mortalities of the two sexes was detected.

  11. Characterization of Small HSPs from Anemonia viridis Reveals Insights into Molecular Evolution of Alpha Crystallin Genes among Cnidarians

    OpenAIRE

    Nicosia, Aldo; Maggio, Teresa; Mazzola, Salvatore; Gianguzza, Fabrizio; Cuttitta, Angela; Costa, Salvatore

    2014-01-01

    Gene family encoding small Heat-Shock Proteins (sHSPs containing α-crystallin domain) are found both in prokaryotic and eukaryotic organisms; however, there is limited knowledge of their evolution. In this study, two small HSP genes termed AvHSP28.6 and AvHSP27, both organized in one intron and two exons, were characterised in the Mediterranean snakelocks anemone Anemonia viridis. The release of the genome sequence of Hydra magnipapillata and Nematostella vectensis enabled a comprehensive stu...

  12. Disseminated Mycosis in Veiled Chameleons (Chamaeleo calyptratus) Caused by Chamaeleomyces granulomatis, a New Fungus Related to Paecilomyces viridis

    DEFF Research Database (Denmark)

    Sigler, Lynne; Gibas, Connie Fe C.; Kokotovic, Branko

    2010-01-01

    An outbreak of disseminated granulomatous disease occurred in a group of veiled chameleons (Chamaeleo calyptratus) in a zoo collection. An adult female and six offspring developed large granulomas in multiple organs and were euthanized. At necropsy, roughly spherical yellow-to-white nodules 1 to 3...... of morphology results to represent Paecilomyces viridis, a species known only from one outbreak of fatal mycosis in carpet chameleons (Furcifer lateralis). Data obtained from morphological studies and from phylogenetic analyses of nuclear ribosomal rRNA (rDNA) sequence data revealed the Danish chameleon....... Chamaeleomyces species appear to be rare but aggressive pathogens of chameleons....

  13. Potential of Rhodobacter capsulatus Grown in Anaerobic-Light or Aerobic-Dark Conditions as Bioremediation Agent for Biological Wastewater Treatments

    OpenAIRE

    Stefania Costa; Saverio Ganzerli; Irene Rugiero; Simone Pellizzari; Paola Pedrini; Elena Tamburini

    2017-01-01

    The use of microorganisms to clean up wastewater provides a cheaper alternative to the conventional treatment plant. The efficiency of this method can be improved by the choice of microorganism with the potential of removing contaminants. One such group is photosynthetic bacteria. Rhodobacter capsulatus is a purple non-sulfur bacterium (PNSB) found to be capable of different metabolic activities depending on the environmental conditions. Cell growth in different media and conditions was teste...

  14. The solute specificity profiles of nucleobase cation symporter 1 (NCS1) from Zea mays and Setaria viridis illustrate functional flexibility.

    Science.gov (United States)

    Rapp, Micah; Schein, Jessica; Hunt, Kevin A; Nalam, Vamsi; Mourad, George S; Schultes, Neil P

    2016-03-01

    The solute specificity profiles (transport and binding) for the nucleobase cation symporter 1 (NCS1) proteins, from the closely related C4 grasses Zea mays and Setaria viridis, differ from that of Arabidopsis thaliana and Chlamydomonas reinhardtii NCS1. Solute specificity profiles for NCS1 from Z. mays (ZmNCS1) and S. viridis (SvNCS1) were determined through heterologous complementation studies in NCS1-deficient Saccharomyces cerevisiae strains. The four Viridiplantae NCS1 proteins transport the purines adenine and guanine, but unlike the dicot and algal NCS1, grass NCS1 proteins fail to transport the pyrimidine uracil. Despite the high level of amino acid sequence similarity, ZmNCS1 and SvNCS1 display distinct solute transport and recognition profiles. SvNCS1 transports adenine, guanine, hypoxanthine, cytosine, and allantoin and competitively binds xanthine and uric acid. ZmNCS1 transports adenine, guanine, and cytosine and competitively binds, 5-fluorocytosine, hypoxanthine, xanthine, and uric acid. The differences in grass NCS1 profiles are due to a limited number of amino acid alterations. These amino acid residues do not correspond to amino acids essential for overall solute and cation binding or solute transport, as previously identified in bacterial and fungal NCS1, but rather may represent residues involved in subtle solute discrimination. The data presented here reveal that within Viridiplantae, NCS1 proteins transport a broad range of nucleobase compounds and that the solute specificity profile varies with species.

  15. Evolutionary conserved mechanisms pervade structure and transcriptional modulation of allograft inflammatory factor-1 from sea anemone Anemonia viridis.

    Science.gov (United States)

    Cuttitta, Angela; Ragusa, Maria Antonietta; Costa, Salvatore; Bennici, Carmelo; Colombo, Paolo; Mazzola, Salvatore; Gianguzza, Fabrizio; Nicosia, Aldo

    2017-08-01

    Gene family encoding allograft inflammatory factor-1 (AIF-1) is well conserved among organisms; however, there is limited knowledge in lower organisms. In this study, the first AIF-1 homologue from cnidarians was identified and characterised in the sea anemone Anemonia viridis. The full-length cDNA of AvAIF-1 was of 913 bp with a 5' -untranslated region (UTR) of 148 bp, a 3'-UTR of 315 and an open reading frame (ORF) of 450 bp encoding a polypeptide with149 amino acid residues and predicted molecular weight of about 17 kDa. The predicted protein possesses evolutionary conserved EF hand Ca 2+ binding motifs, post-transcriptional modification sites and a 3D structure which can be superimposed with human members of AIF-1 family. The AvAIF-1 transcript was constitutively expressed in all tested tissues of unchallenged sea anemone, suggesting that AvAIF-1 could serve as a general protective factor under normal physiological conditions. Moreover, we profiled the transcriptional activation of AvAIF-1 after challenges with different abiotic/biotic stresses showing induction by warming conditions, heavy metals exposure and immune stimulation. Thus, mechanisms associated to inflammation and immune challenges up-regulated AvAIF-1 mRNA levels. Our results suggest its involvement in the inflammatory processes and immune response of A. viridis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Nutritional value of the marine invertebrates Anemonia viridis and Haliothis tuberculata and effects on serum cholesterol concentration in ratsopen star

    Science.gov (United States)

    Gonzalez, M; Caride, B; Lamas, A; Taboada, C

    2001-09-01

    The purpose of this study was to determine the nutritional value of diets with protein from two marine species (Haliotis tuberculata and Anemonia viridis) as compared to a high-quality protein reference based on casein or casein supplemented with olive oil. We also investigated the effects of these diets on serum lipid levels. Male rats were fed these diets for 23 days. Protein quality indicators (true digestibility, net protein utilization, biological value) were similar to those obtained for casein-based feeds except for lower true digestibility and net protein utilization values for the Anemonia viridis feed. HDL-cholesterol level was significantly higher (p < 0.05) in the groups fed marine species or casein supplemented with olive oil than in the casein group. Total-cholesterol level was higher in the group fed Haliotis tuberculata fed than in the other groups. These results suggest that these marine species are a good protein source, and that they may have positive effects on serum cholesterol level.

  17. HUBUNGAN KEKERABATAN BEBERAPA POPULASI KERANG HIJAU (Perna viridis DI INDONESIA BERDASARKAN SEKUEN CYTROCROME B mtDNA

    Directory of Open Access Journals (Sweden)

    Achmad Sudradjat

    2016-11-01

    Full Text Available Penelitian ini dilakukan untuk mengetahui hubungan kekerabatan stok kerang hijau (Perna viridis di beberapa perairan Indonesia sebagai informasi dasar bagi program pemuliaan. Sampel kerang hijau yang berasal dari populasi alam perairan Tanjung Kait, Kamal, Panimbang, Cirebon, Pasuruan, Kenjeran, dan Pangkep diambil secara acak. Amplifikasi PCR dan sekuensing mitokondria daerah cytochrome B adalah HCO (F: 5’-TAA ACT TCA GGG TGA CCA AAA AAT CA-3’ (26 bp dan LCO (R: 5’-GGT CAA CAA ATC ATA AAG ATA TTG G-3’ (25 bp. Sekuen DNA yang diperoleh digunakan untuk analisis homologi, analisis genetic distance dan analisis kekerabatan. Hasil analisis homologi susunan nukleotida berdasarkan BLAST-N terhadap sekuen mtDNA Perna viridis yang tersimpan di Genebank menunjukkan similaritas 97%. Hasil analisis didapatkan jarak genetik yang terdekat adalah populasi Tanjung Kait dengan Kenjeran sedangkan jarak genetik terjauh adalah populasi Cirebon dengan Kamal. Hubungan kekerabatan yang ditunjukkan dengan dendrogram diperoleh 2 kelompok yaitu 6 populasi membentuk satu kelompok dan populasi Cirebon membentuk kluster tersendiri. Sekuens tersebut mungkin dapat digunakan sebagai penanda dalam program breeding kerang hijau di Indonesia

  18. Mortalidade de Coccus viridis (Hemiptera: Coccidae por Lecanicillium spp. em diferentes órgãos de Coffea arabica

    Directory of Open Access Journals (Sweden)

    Flávio Lemes Fernandes

    2009-04-01

    Full Text Available Objetivou-se neste trabalho avaliar a mortalidade de Coccus viridis por Lecanicillium spp. em folhas e ramos de Coffea arabica. O trabalho foi realizado na casa de vegetação na Universidade Federal de Viçosa, entre fevereiro de 2005 a junho de 2006. Foram utilizadas sementes da variedade Catuaí vermelho de café (C. arabica. A solução nutritiva utilizada foi composta por 3,0 mmol/L de N, 9,0 mmol/L de K, 1,0 mmol/L de P, 4,0 mmol/L de Ca, 2,1 mmol/L de S, 46 µmol/L de B, 0,3 µmol/L de Cu, 60,0 µmol/L de Fe, 2,0 µmol/L de Mg, 0,5 µmol/L de Mo e 36,0 µmol/L de Mn. As cochonilhas e o fungo foram coletados de folhas de café em lavouras comerciais de Viçosa, MG e foram mantidos em gaiolas em Casa de Vegetação. As plantas foram infestadas com oito meses de idade. A infestação foi realizada por contato de C. viridis infectadas com o fungo sobre as cochonilhas sadias. As densidades de C. viridis viva e morta nas folhas e nos ramos foram avaliadas aos 0, 15, 30, 35, 45, 60 e 75 dias após a infestação. Usou-se análise de variância, teste de média de Skott-Knott e análise de regressão linear simples a p<0,05. O fungo Lecanicillium spp. causou mortalidade em todos os estádios de C. viridis. De forma geral, a maior mortalidade ocorreu no terceiro ínstar. Além disso, o fungo causou maior mortalidade nesse inseto praga na face abaxial da folha de café. Mortality of Coccus viridis (Hemiptera: Coccidae by Lecanicillium spp. in differents Coffea arabica organs in greenhouseAbstract. The objective of this work was to evaluate the mortality of Coccus viridis by Lecanicillium spp. on faces of the leaves, and branches of Coffea arabica. This work was conducted in greenhouse at UFV. The experiment was carried out from February 2005 to June 2006. Seeds of the lineage IAC 15 from the variety “Catuaí Vermelho” coffee (C. arabica were used. The nutritive solution utilized was composed for 3. 0 mmol/L of N, 9. 0 mmol/L of K, 1. 0 mmol

  19. A new species of myrmecophilous lady beetle in the genus Diomus (Coleoptera: Coccinellidae: Diomini) from Chiapas, Mexico that feeds on green coffee scale, Coccus viridis (Green) (Hemiptera: Coccidae)

    Science.gov (United States)

    A new species of myrmecophilous lady beetle in the genus Diomus (Coleoptera: Coccinellidae: Diomini) is described from a coffee agroecosystem in Chiapas, Mexico. The new species was found preying on the green coffee scale pest, Coccus viridis (Green), tended primarily by Azteca sericeasur Longino an...

  20. A Study of the Major Phytocoenotic and Economic Attributes of Fragaria Viridis (Duch.) Weston in Natural Conditions (through the Example of East Kazakhstan Region)

    OpenAIRE

    Tatiana A. Vdovina; Olga A. Serova; Nina M. Kadantseva

    2014-01-01

    This article provides data on the phytocoenotic and economic - morphological attributes of Fragaria viridis Duch., green strawberry, in various locations. The most sustainable habitat for the existence of this species has been located near the village of Zimoviye. The ratio between the generative and vegetative species in the examined coenopopulations allows us to subsume them under the invasional and normal types.

  1. A Study of the Major Phytocoenotic and Economic Attributes of Fragaria Viridis (Duch. Weston in Natural Conditions (through the Example of East Kazakhstan Region

    Directory of Open Access Journals (Sweden)

    Tatiana A. Vdovina

    2014-10-01

    Full Text Available This article provides data on the phytocoenotic and economic - morphological attributes of Fragaria viridis Duch., green strawberry, in various locations. The most sustainable habitat for the existence of this species has been located near the village of Zimoviye. The ratio between the generative and vegetative species in the examined coenopopulations allows us to subsume them under the invasional and normal types.

  2. N2 fixing alder (Alnus viridis spp.fruticosa) effects on soil properties across a secondary successional chronosequence in interior Alaska

    Science.gov (United States)

    Jennifer S. Mitchell; Roger W. Ruess

    2009-01-01

    Green alder (Alnus viridis ssp. fruticosa) is a dominant understory shrub during secondary successional development of upland forests throughout interior Alaska, where it contributes substantially to the nitrogen (N) economy through atmospheric N2 fixation. Across a replicated 200+ year old vegetation...

  3. Assessing the herbivore role of the sea-urchin Echinometra viridis: Keys to determine the structure of communities in disturbed coral reefs.

    Science.gov (United States)

    Sangil, Carlos; Guzman, Hector M

    2016-09-01

    Echinometra viridis previously was considered a cryptic species unable to control the development and growth of macroalgae on coral reefs. Its role as a herbivore was seen as minor compared to other grazers present on the reef. However, the present disturbed state of some reefs has highlighted the role played by this sea-urchin. Combining field data with experiments on the Caribbean coast of Panama, we demonstrate that the current community organization on disturbed coral reefs in the Mesoamerican Caribbean is largely due to the action of E. viridis. It is the most abundant sea-urchin species, together with two others (Diadema antillarum and Echinometra lucunter). Field data also indicate that the relationship between its density and the abundance of macroalgae is stronger and it is more negative in impact than those of the other two. However, the niche this urchin exploits most efficiently is confined to leeward reefs with low levels of sedimentation. Outside these habitats, their populations are not decisive in controlling macroalgal growth. Grazing experiments showed that E. viridis consumes more fresh macroalgae per day and per weight of sea-urchin, and is a more effective grazer than D. antillarum or E. lucunter. E. viridis showed food preferences for early-successional turf macroalgae (Acanthophora spicifera), avoiding the less palatable late-successional and fleshy macroalgae (Lobophora variegata, Halimeda opuntia). However, it becomes a generalist herbivore feeding on all varieties of macroalgae when resources are scarce. H. opuntia is the macroalga that most resists E. viridis activity, which may explain its wide distribution. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Metalotioninas en Perna viridis (Bivalvia: Mytilidae: variación estacional y su relación con la biología reproductiva Metallothioneins in Perna viridis (Bivalvia: Mytilidae: seasonal variation and its relation to reproductive biology

    Directory of Open Access Journals (Sweden)

    Mairin Lemus

    2013-06-01

    Full Text Available Las metalotioninas (Mts son proteínas de baja masa molecular que juegan un rol importante en la detoxificación de metales, en vista de su papel ecotoxicológico se evaluaron las metalotioneínas (MTs en 350 ejemplares del bivalvo Perna viridis en dos localidades de la costa norte del estado Sucre, desde febrero hasta diciembre 2003. Se determinaron los índices biométricos: índice de condición (IC, rendimiento de carne (RC y relación peso seco-talla (PSL. Las Mts fueron separadas por cromatografía de exclusión molecular, Sephadex G-50 y se cuantificaron por saturación con cadmio. Los índices biométricos (RC y PSL mostraron variaciones estacionales, entre localidades y estados de madurez, con la excepción del CI. No se encontraron diferencias significativas entre sexos. Las Mts mostraron variaciones estacionales, con concentraciones más elevadas entre febrero y marzo y mínimos entre septiembre y diciembre, que coincidieron con los períodos de alta y baja productividad en el área, respectivamente. Los mejillones de Río Caribe presentaron una mayor concentración de Mts que los de Chacopata. Los mejillones inmaduros mostraron la mayor concentración de Mts y la más baja en los desovados. Se encontró una relación negativa y significativa entre Mts y CI. Los resultados demuestran que las Mts de Perna viridis están influidas por el índice de condición y la condición reproductiva, asi como también pot los factores físico-químicos del ambiente marino.Metallothionein is a cytosolic protein found in a variety of tissues and have been involved in the regulation of essential trace metals such as copper and zinc, and in the detoxification of essential and nonessential metals. With the aim to study their seasonal variation and their possible role in reproductive behavior, we evaluated metallothioneins (Mts in Perna viridis, taken from Rio Caribe and Chacopata localities in the North coast of Sucre state, Venezuela. A total of 325

  5. BIOCUMULACIÓN Y EFECTO DEL CADMIO EN JUVENILES DEL MEJILLÓN VERDE Perna viridis (L. 1758 (MYTILOIDA: MYTILIDAEI BIOCUMULACIÓN AND EFFECT OF CADMIUM IN JUVENILES THE GREEN MUSSEL Perna viridis (L. 1758 (MYTILOIDA: MYTILIDAE

    Directory of Open Access Journals (Sweden)

    VANESSA ACOSTA

    2018-05-01

    Full Text Available We evaluated the potential for bioaccumulation of Cadmium in juveniles of the green-lipped mussel Perna viridis (with average antero-posterior length 12.67±3.02 mm exposed to two sublethal concentrations of cadmium chloride (50 and 80 μgCd/ L and the immediate effect on the RNA/DNA ratio during an exposure period of 8 days. Cadmium levels were quantified in all tissues and the shell, using an atomic absorption spectrophotometer with air-acetylene flame. The ratio RNA/DNA was quantified in the abductor muscle. After two days of the experiment, the mussels showed the highest accumulation of Cd in tissues, which was proportional to the experimental concentrations, and then the levels in tissues remained unchanged during the rest of the experiment. Organisms in the control treatment maintained a constant amount of cadmium throughout the study. The accumulation in the shell was continuous and proportional to the concentration of the treatments. The ratio RNA/DNA showed a decline in both treatments, while organisms in the control group showed the highest levels and without significant changes throughout the experiment. Results showed an immediate incorporation of Cd in organisms, during the first 48 hours of exposure, with subsequent regulation of the metal, generating possibly a metabolic cost to counteract the toxic effect, leading to a decrease in RNA/ DNA ratio. Perna viridis is a species capable of regulating tolerable levels of cadmium, responding with effective regulatory mechanisms that allow it to acclimate to contaminated areas. The continuous accumulation of Cd in the shell suggests that this compartment can be used as an indicator of pollution for this metal in aquatic systems.

  6. Componentes bioquímicos de los tejidos de Perna perna y P. viridis (Lineo, 1758 (Bivalvia: Mytilidae, en relación al crecimiento en condiciones de cultivo suspendido Biochemical components of the tissues of Perna perna and P. viridis (Lineo, 1758 (Bivalvia: Mytilidae, in relation to the growth under conditions of suspended cultivation

    Directory of Open Access Journals (Sweden)

    Vanessa Acosta

    2010-01-01

    Full Text Available Se evaluó los cambios ocurridos en carbohidratos, proteínas y lípidos de la glándula digestiva, músculo y lóbulos gonadales de los mejillones Perna perna y P. viridis bajo condiciones de cultivo suspendido en el Golfo de Cariaco, Venezuela. Paralelamente, se llevaron registros de la condición reproductiva de ambas especies y de temperatura, clorofila a y seston. Los resultados muestraron que en los tejidos analizados de ambas especies, los lóbulos gonadales presentaron las mayores variaciones de los sustratos energéticos estudiados. La variación de los sustratos energéticos se explicó en ambos mejillones mediante desarrollo gonádico y la disponibilidad de alimento, particularmente clorofila a para P. perna y seston total para P. viridis. La temperatura fue un factor que afectó negativamente a P. viridis. Los contenidos de los diferentes sustratos energéticos observados en P. perna fueron más altos que en P. viridis, a lo largo de casi todo el periodo experimental, lo que indicó que esta especie mostró una mayor capacidad para explotar de manera más eficiente los recursos alimenticios presentes en las condiciones de cultivo suspendido.In the organisms, the variations of the biochemical composition of reproductive and somatic tissues in the growth permit to infer about its adaptative to environment. In the present study, we evaluate the changes observed in carbohydrates, lipids and proteins of digestive gland, muscle and gonad tissues of Perna perna and P. viridis, growing in suspended culture at Cariaco Gulf , Venezuela. The reproductive condition of both mussels and environmental factors (temperature, chlorophyll a and of the seston were determinate. The results show that, in both species, the gonadic lobes showed the highest variations in the biochemical component. The variations in the biochemical components were direct explained by the variations in the gonad development and the food availability, particularly chlorophyll a

  7. Overexpression of pucC improves the heterologous protein expression level in a Rhodobacter sphaeroides expression system.

    Science.gov (United States)

    Cheng, L; Chen, G; Ding, G; Zhao, Z; Dong, T; Hu, Z

    2015-04-27

    The Rhodobacter sphaeroides system has been used to express membrane proteins. However, its low yield has substantially limited its application. In order to promote the protein expression capability of this system, the pucC gene, which plays a crucial role in assembling the R. sphaeroides light-harvesting 2 complex (LH2), was overexpressed. To build a pucC overexpression strain, a pucC overexpression vector was constructed and transformed into R. sphaeroides CQU68. The overexpression efficiency was evaluated by quantitative real-time polymerase chain reaction. A well-used reporter β-glucuronidase (GUS) was fusion-expressed with LH2 to evaluate the heterologous protein expression level. As a result, the cell culture and protein in the pucC overexpression strain showed much higher typical spectral absorption peaks at 800 and 850 nm compared with the non-overexpression strain, suggesting a higher expression level of LH2-GUS fusion protein in the pucC overexpression strain. This result was further confirmed by Western blot, which also showed a much higher level of heterologous protein expression in the pucC overexpression strain. We further compared GUS activity in pucC overexpression and non-overexpression strains, the results of which showed that GUS activity in the pucC overexpression strain was approximately ten-fold that in the non-overexpression strain. These results demonstrate that overexpressed pucC can promote heterologous protein expression levels in R. sphaeroides.

  8. Probing energy transfer events in the light harvesting complex 2 (LH2) of Rhodobacter sphaeroides with two-dimensional spectroscopy.

    Science.gov (United States)

    Fidler, Andrew F; Singh, Ved P; Long, Phillip D; Dahlberg, Peter D; Engel, Gregory S

    2013-10-21

    Excitation energy transfer events in the photosynthetic light harvesting complex 2 (LH2) of Rhodobacter sphaeroides are investigated with polarization controlled two-dimensional electronic spectroscopy. A spectrally broadened pulse allows simultaneous measurement of the energy transfer within and between the two absorption bands at 800 nm and 850 nm. The phased all-parallel polarization two-dimensional spectra resolve the initial events of energy transfer by separating the intra-band and inter-band relaxation processes across the two-dimensional map. The internal dynamics of the 800 nm region of the spectra are resolved as a cross peak that grows in on an ultrafast time scale, reflecting energy transfer between higher lying excitations of the B850 chromophores into the B800 states. We utilize a polarization sequence designed to highlight the initial excited state dynamics which uncovers an ultrafast transfer component between the two bands that was not observed in the all-parallel polarization data. We attribute the ultrafast transfer component to energy transfer from higher energy exciton states to lower energy states of the strongly coupled B850 chromophores. Connecting the spectroscopic signature to the molecular structure, we reveal multiple relaxation pathways including a cyclic transfer of energy between the two rings of the complex.

  9. Probing energy transfer events in the light harvesting complex 2 (LH2) of Rhodobacter sphaeroides with two-dimensional spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fidler, Andrew F.; Singh, Ved P.; Engel, Gregory S. [Department of Chemistry, The Institute for Biophysical Dynamics, and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637 (United States); Long, Phillip D.; Dahlberg, Peter D. [Graduate Program in the Biophysical Sciences, The University of Chicago, Chicago, Illinois 60637 (United States)

    2013-10-21

    Excitation energy transfer events in the photosynthetic light harvesting complex 2 (LH2) of Rhodobacter sphaeroides are investigated with polarization controlled two-dimensional electronic spectroscopy. A spectrally broadened pulse allows simultaneous measurement of the energy transfer within and between the two absorption bands at 800 nm and 850 nm. The phased all-parallel polarization two-dimensional spectra resolve the initial events of energy transfer by separating the intra-band and inter-band relaxation processes across the two-dimensional map. The internal dynamics of the 800 nm region of the spectra are resolved as a cross peak that grows in on an ultrafast time scale, reflecting energy transfer between higher lying excitations of the B850 chromophores into the B800 states. We utilize a polarization sequence designed to highlight the initial excited state dynamics which uncovers an ultrafast transfer component between the two bands that was not observed in the all-parallel polarization data. We attribute the ultrafast transfer component to energy transfer from higher energy exciton states to lower energy states of the strongly coupled B850 chromophores. Connecting the spectroscopic signature to the molecular structure, we reveal multiple relaxation pathways including a cyclic transfer of energy between the two rings of the complex.

  10. Probing energy transfer events in the light harvesting complex 2 (LH2) of Rhodobacter sphaeroides with two-dimensional spectroscopy

    International Nuclear Information System (INIS)

    Fidler, Andrew F.; Singh, Ved P.; Engel, Gregory S.; Long, Phillip D.; Dahlberg, Peter D.

    2013-01-01

    Excitation energy transfer events in the photosynthetic light harvesting complex 2 (LH2) of Rhodobacter sphaeroides are investigated with polarization controlled two-dimensional electronic spectroscopy. A spectrally broadened pulse allows simultaneous measurement of the energy transfer within and between the two absorption bands at 800 nm and 850 nm. The phased all-parallel polarization two-dimensional spectra resolve the initial events of energy transfer by separating the intra-band and inter-band relaxation processes across the two-dimensional map. The internal dynamics of the 800 nm region of the spectra are resolved as a cross peak that grows in on an ultrafast time scale, reflecting energy transfer between higher lying excitations of the B850 chromophores into the B800 states. We utilize a polarization sequence designed to highlight the initial excited state dynamics which uncovers an ultrafast transfer component between the two bands that was not observed in the all-parallel polarization data. We attribute the ultrafast transfer component to energy transfer from higher energy exciton states to lower energy states of the strongly coupled B850 chromophores. Connecting the spectroscopic signature to the molecular structure, we reveal multiple relaxation pathways including a cyclic transfer of energy between the two rings of the complex

  11. Phototrophic hydrogen production from glucose by pure and co-cultures of Clostridium butyricum and Rhodobacter sphaeroides

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Herbert H.P.; Zhu, Heguang; Zhang, Tong [Centre for Environmental Engineering Research, Department of Civil Engineering, University of Hong Kong, Pokfulam Road, Hong Kong (China)

    2006-12-15

    Phototrophic hydrogen production from glucose by pure and co-cultures of Clostridium butyricum and Rhodobacter sphaeroides was studied in batch experiments. Results showed that in all batches hydrogen was produced after a lag phase of about 10h; pure culture of R. sphaeroides produced hydrogen at rates substantially lower than C. butyricum. In co-culture systems, R. sphaeroides even with cell populations 5.9 times higher still could not compete with C. butyricum for glucose. In co-culture systems, R. sphaeroides syntrophically interacted with C. butyricum, using the acetate and butyrate produced by the latter as substrate for hydrogen production. Hydrogen production was ceased in all batches when the pH was lowered to the level of pH 6.5, resulting from the accumulation of fatty acids. It was also demonstrated in this study that fluorescence in situ hybridization (FISH) was an effective means for the quantification of the relative abundance of individual bacteria in a co-culture system. (author)

  12. Structural model and excitonic properties of the dimeric RC-LH1-PufX complex from Rhodobacter sphaeroides

    International Nuclear Information System (INIS)

    Sener, Melih; Hsin, Jen; Trabuco, Leonardo G.; Villa, Elizabeth; Qian, Pu; Hunter, C. Neil; Schulten, Klaus

    2009-01-01

    The light-harvesting apparatus of the purple bacterial photosynthetic unit consists of a pool of peripheral light-harvesting complexes that transfer excitation energy to a reaction center (RC) via the surrounding pigment-protein complex LH1. Recent electron microscopy and atomic force microscopy studies have revealed that RC-LH1 units of Rhodobacter (Rba.) sphaeroides form membrane-bending dimeric complexes together with the polypeptide PufX. We present a structural model for these RC-LH1-PufX dimeric complexes constructed using the molecular dynamics flexible fitting method based on an EM density map. The arrangement of the LH1 BChls displays a distortion near the proposed location of the PufX polypeptide. The resulting atomic model for BChl arrays is used to compute the excitonic properties of the dimeric RC-LH1 complex. A comparison is presented between the structural and excitonic features of the S-shaped dimeric BChl array of Rba. sphaeroides and the circular BChl arrangement found in other purple bacteria

  13. Resonance Raman spectroscopy of 2H-labelled spheroidenes in petroleum ether and in the Rhodobacter sphaeroides reaction centre.

    Science.gov (United States)

    Kok, P; Köhler, J; Groenen, E J; Gebhard, R; van der Hoef, I; Lugtenburg, J; Farhoosh, R; Frank, H A

    1997-03-01

    As a step towards the structural analysis of the carotenoid spheroidene in the Rhodobacter sphaeroides reaction centre, we present the resonance Raman spectra of 14-2H, 15-2H, 15'-2H, 14'-2H, 14,15'-2H2 and 15-15'-2H2 spheroidenes in petroleum ether and, except for 14,15'-2H2 spheroidene, in the Rb. sphaeroides R26 reaction center (RC). Analysis of the spectral changes upon isotopic substitution allows a qualitative assignment of most of the vibrational bands to be made. For the all-trans spheroidenes in solution the resonance enhancement of the Raman bands is determined by the participation of carbon carbon stretching modes in the centre of the conjugated chain, the C9 to C15' region. For the RC-bound 15,15'-cis spheroidenes, enhancement is determined by the participation of carbon-carbon stretching modes in the centre of the molecule, the C13 to C13' region. Comparison of the spectra in solution and in the RC reveals evidence for an out-of-plane distortion of the RC-bound spheroidene in the central C14 to C14' region of the carotenoid. The characteristic 1240 cm-1 band in the spectrum of the RC-bound spheroidene has been assigned to a normal mode that contains the coupled C12-C13 and C13'-C12' stretch vibrations.

  14. Direct visualization of exciton reequilibration in the LH1 and LH2 complexes of Rhodobacter sphaeroides by multipulse spectroscopy.

    Science.gov (United States)

    Cohen Stuart, Thomas A; Vengris, Mikas; Novoderezhkin, Vladimir I; Cogdell, Richard J; Hunter, C Neil; van Grondelle, Rienk

    2011-05-04

    The dynamics of the excited states of the light-harvesting complexes LH1 and LH2 of Rhodobacter sphaeroides are governed, mainly, by the excitonic nature of these ring-systems. In a pump-dump-probe experiment, the first pulse promotes LH1 or LH2 to its excited state and the second pulse dumps a portion of the excited state. By selective dumping, we can disentangle the dynamics normally hidden in the excited-state manifold. We find that by using this multiple-excitation technique we can visualize a 400-fs reequilibration reflecting relaxation between the two lowest exciton states that cannot be directly explored by conventional pump-probe. An oscillatory feature is observed within the exciton reequilibration, which is attributed to a coherent motion of a vibrational wavepacket with a period of ∼150 fs. Our disordered exciton model allows a quantitative interpretation of the observed reequilibration processes occurring in these antennas. Copyright © 2011 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  15. Genetics and physiology of cell wall polysaccharides in the model C4 grass, Setaria viridis spp.

    Science.gov (United States)

    Ermawar, Riksfardini A; Collins, Helen M; Byrt, Caitlin S; Henderson, Marilyn; O'Donovan, Lisa A; Shirley, Neil J; Schwerdt, Julian G; Lahnstein, Jelle; Fincher, Geoffrey B; Burton, Rachel A

    2015-10-02

    Setaria viridis has emerged as a model species for the larger C4 grasses. Here the cellulose synthase (CesA) superfamily has been defined, with an emphasis on the amounts and distribution of (1,3;1,4)-β-glucan, a cell wall polysaccharide that is characteristic of the grasses and is of considerable value for human health. Orthologous relationship of the CesA and Poales-specific cellulose synthase-like (Csl) genes among Setaria italica (Si), Sorghum bicolor (Sb), Oryza sativa (Os), Brachypodium distachyon (Bradi) and Hordeum vulgare (Hv) were compared using bioinformatics analysis. Transcription profiling of Csl gene families, which are involved in (1,3;1,4)-β-glucan synthesis, was performed using real-time quantitative PCR (Q-PCR). The amount of (1,3;1,4)-β-glucan was measured using a modified Megazyme assay. The fine structures of the (1,3;1,4)-β-glucan, as denoted by the ratio of cellotriosyl to cellotetraosyl residues (DP3:DP4 ratio) was assessed by chromatography (HPLC and HPAEC-PAD). The distribution and deposition of the MLG was examined using the specific antibody BG-1 and captured using fluorescence and transmission electron microscopy (TEM). The cellulose synthase gene superfamily contains 13 CesA and 35 Csl genes in Setaria. Transcript profiling of CslF, CslH and CslJ gene families across a vegetative tissue series indicated that SvCslF6 transcripts were the most abundant relative to all other Csl transcripts. The amounts of (1,3;1,4)-β-glucan in Setaria vegetative tissues ranged from 0.2% to 2.9% w/w with much smaller amounts in developing grain (0.003% to 0.013% w/w). In general, the amount of (1,3;1,4)-β-glucan was greater in younger than in older tissues. The DP3:DP4 ratios varied between tissue types and across developmental stages, and ranged from 2.4 to 3.0:1. The DP3:DP4 ratios in developing grain ranged from 2.5 to 2.8:1. Micrographs revealing the distribution of (1,3;1,4)-β-glucan in walls of different cell types and the data were

  16. Qualitative Assessment and Management of Microplastics in Asian Green Mussels (Perna viridis Cultured in Bacoor Bay, Cavite, Phillipines

    Directory of Open Access Journals (Sweden)

    Cristian Ryan Argamino

    2016-07-01

    Full Text Available Microplastics (> 5 mm have gained popularity in research and the public eye in recent years. This is due to the fact that they contain persistent organic pollutants (POPs which pose potential risks to the environment and human health. Bivalves, which are filter feeders, are considered to be good indicators of marine pollution. In this preliminary study, Asian green mussel (Perna viridis, an example of edible bivalve, cultured in Bacoor Bay, Cavite, Philippines was subjected to qualitative analysis to determine the presence of microplastics. Through microscopic analysis, microplastics were found present in the acid-digested mussel soft tissue. A management program is suggested for policy makers and stakeholders to reduce the negative impact of microplastic pollution to both humans and the marine environment.

  17. Effect of body size on accumulation and distribution of 125I in the green mussel (Perna Viridis)

    International Nuclear Information System (INIS)

    Chen Shunhua; Shi Qiong; Zhao Xiaokui

    1997-10-01

    Effect of body size on accumulation and distribution of 125 I in the green mussel (Perna Viridis), has been studied. The results showed that concentration capacity of every part in smaller mussels was higher than that in larger ones. Concentration factors of 125 I in byssus (about 0.5 x 10 3 ∼1.5 x 10 3 ), the highest in all parts of the mussels, were 30∼200 times as that in soft tissues, 200∼600 times as that in feet, 600∼1000 times as that in shells. Although wet weight of byssus was no more than 1% of whole body's wet weight, the content of 125 I accumulated in it accounted for as high as 75% of total 125 I content. The relationship between concentration factor of 125 I in byssus and whole body's wet weight (or shell length) can be described as a negative power function. (16 refs., 2 figs., 3 tabs.)

  18. Temporal variations of heavy metals levels in Perna viridis, on the Chacopata-Bocaripo lagoon axis, Sucre State, Venezuela.

    Science.gov (United States)

    Pinto, Rafael; Acosta, Vanessa; Segnini, Mary Isabel; Brito, Leonor; Martínez, Gregorio

    2015-02-28

    Perna viridis was used as biomonitor to assess heavy metal levels in the Chacopata-Bocaripo lagoon axis, Venezuela, during rain and drought seasons. The mussels were weighed and measured. The metal concentrations were determined by atomic absorption spectrophotometry. For rain period, the order of bioavailability was: Cu>Ni>Mn>Co>Cd>Pb, and for drought: Cu>Mn>Ni>Co>Pb>Cd. The concentrations of Ni, Co, Cd and Pb showed significant differences (P<0.05) in both periods. There was higher metal accumulation during drought season, possibly related to upwelling, since it produces an increase in primary productivity, which translates more food into organisms, making metals bioavailable for mussels. Only Cu and Mn showed significant relationships between the size and metal concentration, during drought period, it may be because of the organisms need for these essential metals in different physiological processes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Partially Purified Extracts of Sea Anemone Anemonia viridis Affect the Growth and Viability of Selected Tumour Cell Lines

    Directory of Open Access Journals (Sweden)

    Matteo Bulati

    2016-01-01

    Full Text Available In the last few years, marine species have been investigated for the presence of natural products with anticancer activity. Using reversed phase chromatography, low molecular weight proteins were fractionated from the sea anemone Anemonia viridis. Four different fractions were evaluated for their cytotoxic activity by means of erythrocyte haemolysis test, MTS, and LDH assays. Finally, the antiproliferative activities of three of these fractions were studied on PC3, PLC/PRF/5, and A375 human cancer cell lines. Our analysis revealed that the four fractions showed different protein contents and diverse patterns of activity towards human PBMC and cancer cell lines. Interestingly, fractions III and IV exerted cytotoxic effects on human cells. Conversely, fractions I and II displayed very low toxic effects associated with antiproliferative activities on cancer cell lines.

  20. A Low Molecular Weight Protein from the Sea Anemone Anemonia viridis with an Anti-Angiogenic Activity.

    Science.gov (United States)

    Loret, Erwann P; Luis, José; Nuccio, Christopher; Villard, Claude; Mansuelle, Pascal; Lebrun, Régine; Villard, Pierre Henri

    2018-04-19

    Sea anemones are a remarkable source of active principles due to a decentralized venom system. New blood vessel growth or angiogenesis is a very promising target against cancer, but the few available antiangiogenic compounds have limited efficacy. In this study, a protein fraction, purified from tentacles of Anemonia viridis , was able to limit endothelial cells proliferation and angiogenesis at low concentration (14 nM). Protein sequences were determined with Edman degradation and mass spectrometry in source decay and revealed homologies with Blood Depressing Substance (BDS) sea anemones. The presence of a two-turn alpha helix observed with circular dichroism and a trypsin activity inhibition suggested that the active principle could be a Kunitz-type inhibitor, which may interact with an integrin due to an Arginine Glycin Aspartate (RGD) motif. Molecular modeling showed that this RGD motif was well exposed to solvent. This active principle could improve antiangiogenic therapy from existing antiangiogenic compounds binding on the Vascular Endothelial Growth Factor (VEGF).

  1. Partially Purified Extracts of Sea Anemone Anemonia viridis Affect the Growth and Viability of Selected Tumour Cell Lines.

    Science.gov (United States)

    Bulati, Matteo; Longo, Alessandra; Masullo, Tiziana; Vlah, Sara; Bennici, Carmelo; Bonura, Angela; Salamone, Monica; Tagliavia, Marcello; Nicosia, Aldo; Mazzola, Salvatore; Colombo, Paolo; Cuttitta, Angela

    2016-01-01

    In the last few years, marine species have been investigated for the presence of natural products with anticancer activity. Using reversed phase chromatography, low molecular weight proteins were fractionated from the sea anemone Anemonia viridis . Four different fractions were evaluated for their cytotoxic activity by means of erythrocyte haemolysis test, MTS, and LDH assays. Finally, the antiproliferative activities of three of these fractions were studied on PC3, PLC/PRF/5, and A375 human cancer cell lines. Our analysis revealed that the four fractions showed different protein contents and diverse patterns of activity towards human PBMC and cancer cell lines. Interestingly, fractions III and IV exerted cytotoxic effects on human cells. Conversely, fractions I and II displayed very low toxic effects associated with antiproliferative activities on cancer cell lines.

  2. METHYL MERCURY IN GREEN MUSCLE (Mytilus viridis L. FROM FISH MARKET MUARA ANGKE : BEFORE AND AFTER COOKING

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    Ermin K. Winarno

    2010-06-01

    Full Text Available The determination of methyl mercury content in green muscle (Mytilus viridis L. that were taken from Pasar Pelelangan Ikan Muara Angke, Jakarta Bay has been carried out. Sampling was taken in November 2005 and March 2006, the samples were bought from the green muscle sellers. The aim of this research is to know the effect of cooking on the content of methyl mercury in green muscle. Samples were homogenized, weighed and washed with aceton and toluene. After washing, the homogenized material was added with HCl solution, extracted with toluene, then the methyl mercury content in toluene extract was analyzed using gas chromatography. The results of this research showed that methyl mercury concentration in raw and cooked green muscle respectively were 0.803 + 0.019 mg/g and 0.443 + 0.035 mg/g (in November 2005 and 0.096 + 0.014 mg/g and 0.079 + 0.016 mg/g (in March 2006 respectively. The methyl mercury content in raw (in November 2005 was higher than in cooked green muscle as permitted concentration in the sea biota by WHO and FAO, it is 0.5 ppm (mg/g, on the other hand the result of the second sampling in March 2006 showed that methyl mercury content in green muscle was lower than permitted concentration. Cooking process of the green muscle decreased methyl mercury content 44.85% (sampling in November 2005 and 17.71% (sampling in March 2006, because methyl mercury that bonded to protein were distributed to boiling water. Methyl mercury content in green muscle after cooking was still lower than the permitted concentration.   Keywords: methyl mercury, green muscle, Mytilus viridis L., Muara Angke

  3. Analysis of [Gossypium capitis-viridis × (G.hirsutum × G.australe2] Trispecific Hybrid and Selected Characteristics.

    Directory of Open Access Journals (Sweden)

    Di Chen

    Full Text Available Speciation is always a contentious and challenging issue following with the presence of gene flow. In Gossypium, there are many valuable resources and wild diploid cotton especially C and B genome species possess some excellent traits which cultivated cotton always lacks. In order to explore character transferring rule from wild cotton to upland tetraploid cotton, the [G. capitis-viridis × (G. hirsutum × G. australe2] triple hybrid was synthesized by interspecies hybridization and chromosome doubling. Morphology comparisons were measured among this hybrid and its parents. It showed that trispecific hybrid F1 had some intermediate morphological characters like leaf style between its parents and some different characters from its parents, like crawl growth characteristics and two kind flower color. It is highly resistant to insects comparing with other cotton species by four year field investigation. By cytogenetic analysis, triple hybrid was further confirmed by meiosis behavior of pollen mother cells. Comparing with regular meiosis of its three parents, it was distinguished by the occurrence of polyads with various numbers of unbalanced microspores and finally generating various abnormal pollen grains. All this phenomenon results in the sterility of this hybrid. This hybrid was further identified by SSR marker from DNA molecular level. It showed that 98 selected polymorphism primers amplified effective bands in this hybrids and its parents. The genetic proportion of three parents in this hybrid is 47.8% from G. hirsutum, 14.3% from G. australe, 7.0% from G. capitis-viridis, and 30.9% recombination bands respectively. It was testified that wild genetic material has been transferred into cultivated cotton and this new germplasm can be incorporated into cotton breeding program.

  4. The 60-kDa heat shock protein (HSP60) of the sea anemone Anemonia viridis: a potential early warning system for environmental changes.

    Science.gov (United States)

    Choresh, O; Ron, E; Loya, Y

    2001-09-01

    Expression of heat shock proteins (HSPs) is often correlated with adaptation to environmental stress. We examined the role of HSP60 (60 kDa) in acclimatization to thermal stress in the sea anemone Anemonia viridis. Using monoclonal antibodies, we identified HSP60 in sea anemones for the first time, and showed that its expression varied with changes in seawater temperature (SWT). Anemonia viridis displayed high levels of HSP60 when extreme temperatures prevailed in stressful habitats such as tidal pools. Specimens sampled from different temperature layers in the same tidal pool differed in their levels of HSP60. Specimens from subtidal zones exhibited a seasonal pattern of expression of HSP60, according to the seasonal SWT. The level of HSP60 was significantly higher in the summer (SWT, 31 degrees C) than in other seasons throughout the year. This study suggests the use of HSP60 expression as a tool for stress detection in marine invertebrates.

  5. Egg parasitoids (Hymenoptera: Mymaridae and Trichogrammatidae) of the gall-making leafhopper Scenergates viridis (Hemiptera: Cicadellidae) from Uzbekistan, with taxonomic notes on the Palaearctic species of Aphelinoidea.

    Science.gov (United States)

    Rakitov, Roman; Triapitsyn, Serguei V

    2013-01-01

    A new species of the Aphelinoidea Girault (Hymenoptera: Trichogrammatidae), A. (Aphelinoidea) sariq Triapitsyn & Rakitov sp. n., is described from Uzbekistan. Both sexes were reared from eggs of the only known truly gall-making leafhopper, Scenergates viridis (Vilbaste), laid inside its galls on camelthorn, Alhagi maurorum Medikus; additional females were found dead inside the galls. Aphelinoidea sariq is the only known species of the nominate subgenus of Aphelinoidea whose body color is predominantly yellow. Taxonomic notes on other Palaearctic species of Aphelinoidea are provided; A. scythica Fursov, syn. n. is synonymized underA. (Aphelinoidea) turanica S. Trjapitzin. Another trichogrammatid, Par-acentrobia (Paracentrobia) sp., was reared from eggs of S. viridis in much smaller numbers. Also described from the same locality and host is Gonatocerus (Lymaenon) mitjaevi Triapitsyn & Rakitov sp. n. (Hymenoptera: Mymaridae).

  6. Dietary Effect of Selenium-enriched Radish Sprouts, Vitamin E, and Rhodobacter capsulatus on Hypocholesterolemia and Immunity of Broiler

    Directory of Open Access Journals (Sweden)

    Tsujii H

    2017-06-01

    Full Text Available The study was designed to investigate the effects of dietary Selenium-enriched radish sprouts (Se-RS, Vitamin E (Vit E, and Rhodobacter capsulatus (RC on immunity, cholesterol concentration, and fatty acid composition in broiler meat. A total of 100 two-week-old male broiler chicks were randomly assigned into five dietary groups: I Control; II Se-RS (5 μg/kg Se-RS; III Se-RS+RC (5 μg/kg Se-RS + 0.2 g/kg RC; IV Se-RS+Vit E (5 μg/kg Se-RS + 50 mg/kg Vit E and V Se-RS+RC+Vit E (5 μg/kg Se-RS + 0.2 g/kg RC + 50 mg/kg Vit E. Diets and clean drinking water were offered ad libitum. After the end of 3-wk of feeding period, serum cholesterol and triglycerides concentrations were lower (P < 0.05 in broilers fed Se-RS + RC + Vit E supplemented diet compared to the control diet. At the end of the 6-wk feeding period, birds fed the Se-RS+RC+Vit E diet significantly (P < 0.05 reduced cholesterol and triglycerides concentrations and improved the ratio of unsaturated fatty acids to saturated fatty acids in broiler meat. The highest (P < 0.05 number of leukocytes was observed in broilers fed Se-RS+RC+Vit E supplemented diet. Foot web index and weights of spleen, bursa, and thymus were significantly (P < 0.05 higher in birds fed Se-RS+RC+Vit E compared to the control diet. Our findings suggest that there are dual benefits of supplementing broiler diets with Se-RS+RC+Vit E because of improvements in the bird’s immunity and meat quality that is important for health conscious consumers.

  7. Electron spin relaxation enhancement measurements of interspin distances in human, porcine, and Rhodobacter electron transfer flavoprotein ubiquinone oxidoreductase (ETF QO)

    Science.gov (United States)

    Fielding, Alistair J.; Usselman, Robert J.; Watmough, Nicholas; Simkovic, Martin; Frerman, Frank E.; Eaton, Gareth R.; Eaton, Sandra S.

    2008-02-01

    Electron transfer flavoprotein-ubiquinone oxidoreductase (ETF-QO) is a membrane-bound electron transfer protein that links primary flavoprotein dehydrogenases with the main respiratory chain. Human, porcine, and Rhodobacter sphaeroides ETF-QO each contain a single [4Fe-4S] 2+,1+ cluster and one equivalent of FAD, which are diamagnetic in the isolated enzyme and become paramagnetic on reduction with the enzymatic electron donor or with dithionite. The anionic flavin semiquinone can be reduced further to diamagnetic hydroquinone. The redox potentials for the three redox couples are so similar that it is not possible to poise the proteins in a state where both the [4Fe-4S] + cluster and the flavoquinone are fully in the paramagnetic form. Inversion recovery was used to measure the electron spin-lattice relaxation rates for the [4Fe-4S] + between 8 and 18 K and for semiquinone between 25 and 65 K. At higher temperatures the spin-lattice relaxation rates for the [4Fe-4S] + were calculated from the temperature-dependent contributions to the continuous wave linewidths. Although mixtures of the redox states are present, it was possible to analyze the enhancement of the electron spin relaxation of the FAD semiquinone signal due to dipolar interaction with the more rapidly relaxing [4Fe-4S] + and obtain point-dipole interspin distances of 18.6 ± 1 Å for the three proteins. The point-dipole distances are within experimental uncertainty of the value calculated based on the crystal structure of porcine ETF-QO when spin delocalization is taken into account. The results demonstrate that electron spin relaxation enhancement can be used to measure distances in redox poised proteins even when several redox states are present.

  8. 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

  9. Detection of metal induced cytopathological alterations and DNA damage in the gills and hepatopancreas of green mussel Perna viridis from Ennore Estuary, Chennai, India

    International Nuclear Information System (INIS)

    Vasanthi, Lourduraj A.; Revathi, Peranandam; Babu Rajendran, Ramaswamy; Munuswamy, Natesan

    2017-01-01

    This study report the impact of heavy metals on cytopathology and DNA damage in the gills and hepatopancreas of Perna viridis collected from Ennore estuary and the Kovalam coastal waters. Principal Component Analysis (PCA) showed significant differences among all variables at the scale of plots. The ultrastructural alterations such as lack of microvilli, distorted mitochondria, electron dense particles and the presence of large mucous droplets were common in the gill and hepatopancreatic cells of mussels from Ennore estuary. However, the gill and hepatopancreatic cells of P. viridis from Kovalam revealed normal compartmentalization of cells. The percentage of tail DNA in the mussels from Ennore estuary was recorded as 12.44 and 10.14% in the gills and hepatopancreas respectively. Overall, it has been demonstrated that the Comet and cytopathological assays are useful biomarkers to assess the level of pollution and it provide reliable information on ecotoxicology and genotoxicology of coastal waters. - Highlights: • Bioaccumulation of heavy metals was studied in P. viridis from Ennore estuary. • Heavy metal accumulation leads to severe cellular and DNA damage. • Comet assay and cytopathology proved to be a biomarker in ecotoxicology. • The data justifies the need of remedial measures along Ennore Estuary.

  10. Accumulation of phenolic compounds in in vitro cultures and wild plants of Lavandula viridis L'Hér and their antioxidant and anti-cholinesterase potential.

    Science.gov (United States)

    Costa, Patrícia; Gonçalves, Sandra; Valentão, Patrícia; Andrade, Paula B; Romano, Anabela

    2013-07-01

    In this study, we evaluated the phenolic profile, antioxidant and anti-cholinesterase potential of different extracts from wild plants and in vitro cultures of Lavandula viridis L'Hér. The HPLC-DAD analysis allowed the identification and quantification of 3-O-caffeoylquinic, 4-O-caffeoylquinic, 5-O-caffeoylquinic and rosmarinic acids, and luteolin and pinocembrin. Water/ethanol extract from in vitro cultures contained the highest amount of the identified phenolic compounds (51652.92 mg/kg). To investigate the antioxidant activity we used Trolox equivalent antioxidant capacity, oxygen radical absorbance capacity, Fe(2+) chelation activity and the inhibition of Fe(2+)-induced lipid peroxidation in mouse brain homogenates (in vitro). Overall, all the extracts from both wild plants and in vitro cultures exhibited ability to scavenge free radicals, to chelate Fe(2+) and to protect against lipid peroxidation. In addition, the extracts from L. viridis were active in inhibiting both acetylcholinesterase and butyrylcholinesterase (Ellman's method). Our findings suggest that L. viridis in vitro cultures represent a promising alternative for the production of active metabolites with antioxidant and anti-cholinesterase activity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. OCCURRENCE IN THE SOIL AND DISPERSAL OF Lecanicillium lecanii, A FUNGAL PATHOGEN OF THE GREEN COFFEE SCALE (Coccus viridis AND COFFEE RUST (Hemileia vastatrix

    Directory of Open Access Journals (Sweden)

    Doug William Jackson

    2012-08-01

    Full Text Available The fungus Lecanicillium lecanii attacks the green scale (Coccus viridis, a pest of coffee, and is also a hyperparasite of coffee rust (Hemileia vastatrix. Knowledge of the epizootiology of this fungus is potentially important for conservation biological control in coffee agroecosystems. The presence of viable propagules of L. lecanii in the soil, a possible environmental reservoir, was assessed using two baiting methods: the standard Galleria mellonella bait method and a C. viridis bait method. Infectious propagules of L. lecanii were detected in soil samples taken from a 45 ha study plot, both nearby and far from recent epizootics of L. lecanii. To test the potential for the transmission of L. lecanii conidia from the soil via rain splash or wind, coffee seedlings with populations of C. viridis were placed near L. lecanii-inoculated soil and then subjected to artificial rain and wind treatments. Rain splash was shown to be a potential transmission mechanism. Dispersal of L. lecanii conidia by the ant Azteca instabilis was tested using field and laboratory ant-exclusion experiments. Azteca instabilis was shown to transport conidia of L. lecanii; however, dispersal by A. instabilis may not be important under field conditions.

  12. Mapping of quantitative trait locus (QTLs that contribute to germination and early seedling drought tolerance in the interspecific cross Setaria italica×Setaria viridis.

    Directory of Open Access Journals (Sweden)

    Lufeng Qie

    Full Text Available Drought tolerance is an important breeding target for enhancing the yields of grain crop species in arid and semi-arid regions of the world. Two species of Setaria, domesticated foxtail millet (S. italica and its wild ancestor green foxtail (S. viridis are becoming widely adopted as models for functional genomics studies in the Panicoid grasses. In this study, the genomic regions controlling germination and early seedling drought tolerance in Setaria were identified using 190 F7 lines derived from a cross between Yugu1, a S. italica cultivar developed in China, and a wild S. viridis genotype collected from Uzbekistan. Quantitative trait loci were identified which contribute to a number of traits including promptness index, radical root length, coleoptile length and lateral root number at germinating stage and seedling survival rate was characterized by the ability of desiccated seedlings to revive after rehydration. A genetic map with 128 SSR markers which spans 1293.9 cM with an average of 14 markers per linkage group of the 9 linkage groups was constructed. A total of eighteen QTLs were detected which included nine that explained over 10% of the phenotypic variance for a given trait. Both the wild green foxtail genotype and the foxtail millet cultivar contributed the favorite alleles for traits detected in this trial, indicating that wild Setaria viridis populations may serve as a reservoir for novel stress tolerance alleles which could be employed in foxtail millet breeding.

  13. Mapping of quantitative trait locus (QTLs) that contribute to germination and early seedling drought tolerance in the interspecific cross Setaria italica×Setaria viridis.

    Science.gov (United States)

    Qie, Lufeng; Jia, Guanqing; Zhang, Wenying; Schnable, James; Shang, Zhonglin; Li, Wei; Liu, Binhui; Li, Mingzhe; Chai, Yang; Zhi, Hui; Diao, Xianmin

    2014-01-01

    Drought tolerance is an important breeding target for enhancing the yields of grain crop species in arid and semi-arid regions of the world. Two species of Setaria, domesticated foxtail millet (S. italica) and its wild ancestor green foxtail (S. viridis) are becoming widely adopted as models for functional genomics studies in the Panicoid grasses. In this study, the genomic regions controlling germination and early seedling drought tolerance in Setaria were identified using 190 F7 lines derived from a cross between Yugu1, a S. italica cultivar developed in China, and a wild S. viridis genotype collected from Uzbekistan. Quantitative trait loci were identified which contribute to a number of traits including promptness index, radical root length, coleoptile length and lateral root number at germinating stage and seedling survival rate was characterized by the ability of desiccated seedlings to revive after rehydration. A genetic map with 128 SSR markers which spans 1293.9 cM with an average of 14 markers per linkage group of the 9 linkage groups was constructed. A total of eighteen QTLs were detected which included nine that explained over 10% of the phenotypic variance for a given trait. Both the wild green foxtail genotype and the foxtail millet cultivar contributed the favorite alleles for traits detected in this trial, indicating that wild Setaria viridis populations may serve as a reservoir for novel stress tolerance alleles which could be employed in foxtail millet breeding.

  14. Spatiotemporal variations in metal accumulation, RNA/DNA ratio and energy reserve in Perna viridis transplanted along a marine pollution gradient in Hong Kong.

    Science.gov (United States)

    Yeung, Jamius W Y; Zhou, Guang-Jie; Leung, Kenneth M Y

    2017-11-30

    We examined spatiotemporal variations of metal levels and three growth related biomarkers, i.e., RNA/DNA ratio (RD), total energy reserve (Et) and condition index (CI), in green-lipped mussels Perna viridis transplanted into five locations along a pollution gradient in the marine environment of Hong Kong over 120days of deployment. There were significant differences in metal levels and biomarker responses among the five sites and six time points. Mussels in two clean sites displayed better CI and significantly lower levels of Ag, Cu, Pb and Zn in their tissues than the other sites. Temporal patterns of RD in P. viridis were found to be site-specific. Across all sites, Et decreased in P. viridis over the deployment period, though the rate of decrease varied significantly among the sites. Therefore, temporal variation of biomarkers should be taken to consideration in mussel-watch programs because such information can help discriminate pollution-induced change from natural variation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. The role of Cercospora zeae-maydis homologs of Rhodobacter sphaeroides 1O2-resistance genes in resistance to the photoactivated toxin cercosporin.

    Science.gov (United States)

    Beseli, Aydin; Goulart da Silva, Marilia; Daub, Margaret E

    2015-01-01

    The photosynthetic bacterium Rhodobacter sphaeroides and plant pathogenic fungus Cercospora nicotianae have been used as models for understanding resistance to singlet oxygen ((1)O(2)), a highly toxic reactive oxygen species. In Rhodobacter and Cercospora, (1)O(2) is derived, respectively, from photosynthesis and from the (1)O(2)-generating toxin cercosporin which the fungus produces to parasitize plants. We identified common genes recovered in transcriptome studies of putative (1)O(2)-resistance genes in these two systems, suggesting common (1)O(2)-resistance mechanisms. To determine if the Cercospora homologs of R. sphaeroides (1)O(2)-resistance genes are involved in resistance to cercosporin, we expressed the genes in the cercosporin-sensitive fungus Neurospora crassa and assayed for increases in cercosporin resistance. Neurospora crassa transformants expressing genes encoding aldo/keto reductase, succinyl-CoA ligase, O-acetylhomoserine (thiol) lyase, peptide methionine sulphoxide reductase and glutathione S-transferase did not have elevated levels of cercosporin resistance. Several transformants expressing aldehyde dehydrogenase were significantly more resistant to cercosporin. Expression of the transgene and enzyme activity did not correlate with resistance, however. We conclude that although the genes tested in this study are important in (1)O(2) resistance in R. sphaeroides, their Cercospora homologs are not involved in resistance to (1)O(2) generated from cercosporin. © FEMS 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Increasing pCO2 correlates with low concentrations of intracellular dimethylsulfoniopropionate in the sea anemone Anemonia viridis.

    Science.gov (United States)

    Borell, Esther M; Steinke, Michael; Horwitz, Rael; Fine, Maoz

    2014-02-01

    Marine anthozoans maintain a mutualistic symbiosis with dinoflagellates that are prolific producers of the algal secondary metabolite dimethylsulfoniopropionate (DMSP), the precursor of the climate-cooling trace gas dimethyl sulfide (DMS). Surprisingly, little is known about the physiological role of DMSP in anthozoans and the environmental factors that regulate its production. Here, we assessed the potential functional role of DMSP as an antioxidant and determined how future increases in seawater pCO2 may affect DMSP concentrations in the anemone Anemonia viridis along a natural pCO2 gradient at the island of Vulcano, Italy. There was no significant difference in zooxanthellae genotype and characteristics (density of zooxanthellae, and chlorophyll a) as well as protein concentrations between anemones from three stations along the gradient, V1 (3232 μatm CO2), V2 (682 μatm) and control (463 μatm), which indicated that A. viridis can acclimate to various seawater pCO2. In contrast, DMSP concentrations in anemones from stations V1 (33.23 ± 8.30 fmol cell(-1)) and V2 (34.78 ± 8.69 fmol cell(-1)) were about 35% lower than concentrations in tentacles from the control station (51.85 ± 12.96 fmol cell(-1)). Furthermore, low tissue concentrations of DMSP coincided with low activities of the antioxidant enzyme superoxide dismutase (SOD). Superoxide dismutase activity for both host (7.84 ± 1.37 U·mg(-1) protein) and zooxanthellae (2.84 ± 0.41 U·mg(-1) protein) at V1 was 40% lower than at the control station (host: 13.19 ± 1.42; zooxanthellae: 4.72 ± 0.57 U·mg(-1) protein). Our results provide insight into coastal DMSP production under predicted environmental change and support the function of DMSP as an antioxidant in symbiotic anthozoans.

  17. Evidence of accelerated evolution and ectodermal-specific expression of presumptive BDS toxin cDNAs from Anemonia viridis.

    Science.gov (United States)

    Nicosia, Aldo; Maggio, Teresa; Mazzola, Salvatore; Cuttitta, Angela

    2013-10-30

    Anemonia viridis is a widespread and extensively studied Mediterranean species of sea anemone from which a large number of polypeptide toxins, such as blood depressing substances (BDS) peptides, have been isolated. The first members of this class, BDS-1 and BDS-2, are polypeptides belonging to the β-defensin fold family and were initially described for their antihypertensive and antiviral activities. BDS-1 and BDS-2 are 43 amino acid peptides characterised by three disulfide bonds that act as neurotoxins affecting Kv3.1, Kv3.2 and Kv3.4 channel gating kinetics. In addition, BDS-1 inactivates the Nav1.7 and Nav1.3 channels. The development of a large dataset of A. viridis expressed sequence tags (ESTs) and the identification of 13 putative BDS-like cDNA sequences has attracted interest, especially as scientific and diagnostic tools. A comparison of BDS cDNA sequences showed that the untranslated regions are more conserved than the protein-coding regions. Moreover, the KA/KS ratios calculated for all pairwise comparisons showed values greater than 1, suggesting mechanisms of accelerated evolution. The structures of the BDS homologs were predicted by molecular modelling. All toxins possess similar 3D structures that consist of a triple-stranded antiparallel β-sheet and an additional small antiparallel β-sheet located downstream of the cleavage/maturation site; however, the orientation of the triple-stranded β-sheet appears to differ among the toxins. To characterise the spatial expression profile of the putative BDS cDNA sequences, tissue-specific cDNA libraries, enriched for BDS transcripts, were constructed. In addition, the proper amplification of ectodermal or endodermal markers ensured the tissue specificity of each library. Sequencing randomly selected clones from each library revealed ectodermal-specific expression of ten BDS transcripts, while transcripts of BDS-8, BDS-13, BDS-14 and BDS-15 failed to be retrieved, likely due to under-representation in our

  18. Evidence of Accelerated Evolution and Ectodermal-Specific Expression of Presumptive BDS Toxin cDNAs from Anemonia viridis

    Directory of Open Access Journals (Sweden)

    Aldo Nicosia

    2013-10-01

    Full Text Available Anemonia viridis is a widespread and extensively studied Mediterranean species of sea anemone from which a large number of polypeptide toxins, such as blood depressing substances (BDS peptides, have been isolated. The first members of this class, BDS-1 and BDS-2, are polypeptides belonging to the β-defensin fold family and were initially described for their antihypertensive and antiviral activities. BDS-1 and BDS-2 are 43 amino acid peptides characterised by three disulfide bonds that act as neurotoxins affecting Kv3.1, Kv3.2 and Kv3.4 channel gating kinetics. In addition, BDS-1 inactivates the Nav1.7 and Nav1.3 channels. The development of a large dataset of A. viridis expressed sequence tags (ESTs and the identification of 13 putative BDS-like cDNA sequences has attracted interest, especially as scientific and diagnostic tools. A comparison of BDS cDNA sequences showed that the untranslated regions are more conserved than the protein-coding regions. Moreover, the KA/KS ratios calculated for all pairwise comparisons showed values greater than 1, suggesting mechanisms of accelerated evolution. The structures of the BDS homologs were predicted by molecular modelling. All toxins possess similar 3D structures that consist of a triple-stranded antiparallel β-sheet and an additional small antiparallel β-sheet located downstream of the cleavage/maturation site; however, the orientation of the triple-stranded β-sheet appears to differ among the toxins. To characterise the spatial expression profile of the putative BDS cDNA sequences, tissue-specific cDNA libraries, enriched for BDS transcripts, were constructed. In addition, the proper amplification of ectodermal or endodermal markers ensured the tissue specificity of each library. Sequencing randomly selected clones from each library revealed ectodermal-specific expression of ten BDS transcripts, while transcripts of BDS-8, BDS-13, BDS-14 and BDS-15 failed to be retrieved, likely due to under

  19. Morphostasis in a novel eukaryote illuminates the evolutionary transition from phagotrophy to phototrophy: description of Rapaza viridis n. gen. et sp. (Euglenozoa, Euglenida

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    Yamaguchi Aika

    2012-03-01

    Full Text Available Abstract Background Morphostasis of traits in different species is necessary for reconstructing the evolutionary history of complex characters. Studies that place these species into a molecular phylogenetic context test hypotheses about the transitional stages that link divergent character states. For instance, the transition from a phagotrophic mode of nutrition to a phototrophic lifestyle has occurred several times independently across the tree of eukaryotes; one of these events took place within the Euglenida, a large group of flagellates with diverse modes of nutrition. Phototrophic euglenids form a clade that is nested within lineages of phagotrophic euglenids and that originated through a secondary endosymbiosis with green algae. Although it is clear that phototrophic euglenids evolved from phagotrophic ancestors, the morphological disparity between species representing these different nutritional modes remains substantial. Results We cultivated a novel marine euglenid, Rapaza viridis n. gen. et sp. ("green grasper", and a green alga, Tetraselmis sp., from the same environment. Cells of R. viridis were comprehensively characterized with light microscopy, SEM, TEM, and molecular phylogenetic analysis of small subunit rDNA sequences. Ultrastructural and behavioral observations demonstrated that this isolate habitually consumes a specific strain of Tetraselmis prey cells and possesses a functional chloroplast that is homologous with other phototrophic euglenids. A novel feeding apparatus consisting of a reduced rod of microtubules facilitated this first and only example of mixotrophy among euglenids. R. viridis also possessed a robust photoreception apparatus, two flagella of unequal length, euglenoid movement, and a pellicle consisting of 16 strips and one (square-shaped whorl of posterior strip reduction. The molecular phylogenetic data demonstrated that R. viridis branches as the nearest sister lineage to phototrophic euglenids

  20. NMR-based metabolomic studies on the toxicological effects of cadmium and copper on green mussels Perna viridis

    International Nuclear Information System (INIS)

    Wu Huifeng; Wang Wenxiong

    2010-01-01

    Traditional toxicology studies have focused on selected biomarkers to characterize the biological stress induced by metals in marine organisms. In this study, a system biology tool, metabolomics, was applied to the marine mussel Perna viridis to investigate changes in the metabolic profiles of soft tissue as a response to copper (Cu) and cadmium (Cd), both as single metal and as a mixture. The major metabolite changes corresponding to metal exposure are related to amino acids, osmolytes, and energy metabolites. Following metal exposure for 1 week, there was a significant increase in the levels of branched chain amino acids, histidine, glutamate, glutamine, hypotaurine, dimethylglycine, arginine and ATP/ADP. For the Cu + Cd co-exposed mussels, the levels of lactate, branched chain amino acid, succinate, and NAD increased, whereas the levels of glucose, glycogen, and ATP/ADP decreased, indicating a different metabolic profile for the single metal exposure groups. After 2 weeks of exposure, the mussels showed acclimatization to Cd exposure based on the recovery of some metabolites. However, the metabolic profile induced by the metal mixture was very similar to that from Cu exposure, suggesting that Cu dominantly induced the metabolic disturbances. Both Cu and Cd may lead to neurotoxicity, disturbances in energy metabolism, and osmoregulation changes. These results demonstrate the high applicability and reliability of NMR-based metabolomics in interpreting the toxicological mechanisms of metals using global metabolic biomarkers.

  1. Biomonitoring of Mercury Contamination at Petroleum Production Platforms in the Gulf of Thailand using Transplanted Green Mussel, Perna viridis

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    Chatree Ritthong

    2011-01-01

    Full Text Available Assessment of mercury contamination was conducted using transplanted green mussels (Perna viridis. Mussels were first exposed to HgCl2 at 0.5, 1.0, 2.5, and 5.0 nmol/L for 8 weeks at laboratory conditions. The result showed that Hg level in the water decreased rapidly, while Hg in mussels increased coincidentally with the applied doses. After 8 weeks the Hg, levels in tissue were a thousand-fold higher than that in the water. Mussels were then transplanted to 3 petroleum production platforms for field study. The result revealed that survival and growth rates of transplanted mussels at all 3 stations were in close to each other but significantly lower than that from the reference site. Hg concentrations in the tissues of transplanted mussels ranged from less than 0.010 to 0.173 µg/g, and Hg concentrations in mussel tissues from all stations were significantly increased within 2 months, while Hg levels in mussel tissues from reference site were not changed. Hg levels of transplanted mussels increased with increasing depths of the water. The transplanted mussels showed no signs of any physical anomalies, indicating that transplanted mussels could be maintained for up to 3 months in an un-natural habitat, such as petroleum production platforms, where food is much less abundant.

  2. European green lizard (Lacerta viridis) personalities: Linking behavioural types to ecologically relevant traits at different ontogenetic stages.

    Science.gov (United States)

    Bajer, Katalin; Horváth, Gergely; Molnár, Orsolya; Török, János; Garamszegi, László Zsolt; Herczeg, Gábor

    2015-02-01

    Consistent individual differences within (animal personality) and across (behavioural syndrome) behaviours became well recognized during the past decade. Nevertheless, our knowledge about the evolutionary and developmental mechanisms behind the phenomena is still incomplete. Here, we explored if risk-taking and exploration were consistent and linked to different ecologically relevant traits in wild-caught adult male European green lizards (Lacerta viridis) and in their 2-3 weeks old laboratory-reared offspring. Both adults and juveniles displayed animal personality, consistency being higher in juveniles. We found correlation between risk-taking and exploration (suggestive of a behavioural syndrome) only in adults. Juveniles were more explorative than adults. Large or ectoparasite-free adult males were more explorative than small or parasitized males. Juvenile females tended to be more risk-taking than males. Behaviour of fathers and their offspring did not correlate. We conclude that European green lizards show high behavioural consistency and age is an important determinant of its strength and links to traits likely affecting fitness. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Improved insecticidal toxicity by fusing Cry1Ac of Bacillus thuringiensis with Av3 of Anemonia viridis.

    Science.gov (United States)

    Yan, Fu; Cheng, Xing; Ding, Xuezhi; Yao, Ting; Chen, Hanna; Li, Wenping; Hu, Shengbiao; Yu, Ziquan; Sun, Yunjun; Zhang, Youming; Xia, Liqiu

    2014-05-01

    Av3, a neurotoxin of Anemonia viridis, is toxic to crustaceans and cockroaches but inactive in mammals. In the present study, Av3 was expressed in Escherichia coli Origami B (DE3) and purified by reversed-phase liquid chromatography. The purified Av3 was injected into the hemocoel of Helicoverpa armigera, rendering the worm paralyzed. Then, Av3 was expressed alone or fusion expressed with the Cry1Ac in acrystalliferous strain Cry(-)B of Bacillus thuringiensis. The shape of Cry1Ac was changed by fusion with Av3. The expressed fusion protein, Cry1AcAv3, formed irregular rhombus- or crescent-shaped crystalline inclusions, which is quite different from the shape of original Cry1Ac crystals. The toxicity of Cry1Ac was improved by fused expression. Compared with original Cry1Ac expressed in Cry(-)B, the oral toxicity of Cry1AcAv3 to H. armigera was elevated about 2.6-fold. No toxicity was detected when Av3 was expressed in Cry(-)B alone. The present study confirmed that marine toxins could be used in bio-control and implied that fused expression with other insecticidal proteins could be an efficient way for their application.

  4. A Low Molecular Weight Protein from the Sea Anemone Anemonia viridis with an Anti-Angiogenic Activity

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    Erwann P. Loret

    2018-04-01

    Full Text Available Sea anemones are a remarkable source of active principles due to a decentralized venom system. New blood vessel growth or angiogenesis is a very promising target against cancer, but the few available antiangiogenic compounds have limited efficacy. In this study, a protein fraction, purified from tentacles of Anemonia viridis, was able to limit endothelial cells proliferation and angiogenesis at low concentration (14 nM. Protein sequences were determined with Edman degradation and mass spectrometry in source decay and revealed homologies with Blood Depressing Substance (BDS sea anemones. The presence of a two-turn alpha helix observed with circular dichroism and a trypsin activity inhibition suggested that the active principle could be a Kunitz-type inhibitor, which may interact with an integrin due to an Arginine Glycin Aspartate (RGD motif. Molecular modeling showed that this RGD motif was well exposed to solvent. This active principle could improve antiangiogenic therapy from existing antiangiogenic compounds binding on the Vascular Endothelial Growth Factor (VEGF.

  5. Relationship of Genetics and Cs-137 in Asian Green Mussel (Perna viridis from Nuclear Activities in Asia-Pacific Region

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    Wanwiwa Tumnoi

    2017-03-01

    Full Text Available This study focuses on the relationship of genetics and Cs-137 radiation doses in Asian green mussel (Perna viridis collected from Chonburi province, Thailand. They might accumulate the radiocaesium from the nuclear power plants in the Asia-Pacific region including the Fukushima-Daiichi nuclear power plant via their routine or accidental releases. The radiation doses, estimated using ERICA Tool in the bivalves categorized into 3 different size classes including 4-6, 6-8, and 8-10 cm, were below 0.02 nGy/h. In parallel, Micronucleus test and Comet assay were used to investigate genetic responses in the mussels. They revealed minimum micronucleus frequency (MNF and %Tail DNA varying from 1.80-2.90% and 1.36-1.70%, respectively. The result indicates that neither particular accumulation of Cs-137 nor genetic responses among different size classes of the animals were observed. Furthermore, the radiation doses in the mussels were below the dose limit of 10 µGy/h. Therefore, no radiation effect caused by Cs-137 was found and it was also confirmed by minimal genetic damages. Data obtained can be used as site-specific data for radiological dose and impact assessment and as baseline data to establish the national radiation safety levels to protect Thai marine biota from any possible future nuclear accidents.

  6. Molecular diversity and population structure of Chinese green foxtail [Setaria viridis (L.) Beauv.] revealed by microsatellite analysis.

    Science.gov (United States)

    Jia, Guanqing; Shi, Shenkui; Wang, Chunfang; Niu, Zhengang; Chai, Yang; Zhi, Hui; Diao, Xianmin

    2013-09-01

    Green foxtail (Setaria viridis) is a new model plant for the genomic investigation of C4 photosynthesis biology. As the ancestor of foxtail millet (Setaria italica), an ancient cereal of great importance in arid regions of the world, green foxtail is crucial for the study of domestication and evolution of this ancient crop. In the present study, 288 green foxtail accessions, which were collected from all geographical regions of China, were analysed using 77 simple sequence repeats (SSRs) that cover the whole genome. A high degree of molecular diversity was detected in these accessions, with an average of 33.5 alleles per locus. Two clusters, which were inconsistent with the distribution of eco-geographical regions in China, were inferred from STRUCTURE, Neighbor-Joining, and principal component analysis, indicating a partially mixed distribution of Chinese green foxtails. The higher subpopulation diversity was from accessions mainly collected from North China. A low level of linkage disequilibrium was observed in the green foxtail genome. Furthermore, a combined analysis of green foxtail and foxtail millet landraces was conducted, and the origin and domestication of foxtail millet was inferred in North China.

  7. Expression of homing endonuclease gene and insertion-like element in sea anemone mitochondrial genomes: Lesson learned from Anemonia viridis.

    Science.gov (United States)

    Chi, Sylvia Ighem; Urbarova, Ilona; Johansen, Steinar D

    2018-04-30

    The mitochondrial genomes of sea anemones are dynamic in structure. Invasion by genetic elements, such as self-catalytic group I introns or insertion-like sequences, contribute to sea anemone mitochondrial genome expansion and complexity. By using next generation sequencing we investigated the complete mtDNAs and corresponding transcriptomes of the temperate sea anemone Anemonia viridis and its closer tropical relative Anemonia majano. Two versions of fused homing endonuclease gene (HEG) organization were observed among the Actiniidae sea anemones; in-frame gene fusion and pseudo-gene fusion. We provided support for the pseudo-gene fusion organization in Anemonia species, resulting in a repressed HEG from the COI-884 group I intron. orfA, a putative protein-coding gene with insertion-like features, was present in both Anemonia species. Interestingly, orfA and COI expression were significantly up-regulated upon long-term environmental stress corresponding to low seawater pH conditions. This study provides new insights to the dynamics of sea anemone mitochondrial genome structure and function. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Crystallization and preliminary crystallographic studies of FoxE from Rhodobacter ferrooxidans SW2, an FeII oxidoreductase involved in photoferrotrophy

    International Nuclear Information System (INIS)

    Pereira, L.; Saraiva, I. H.; Coelho, R.; Newman, D. K.; Louro, R. O.; Frazão, C.

    2012-01-01

    Crystals of the R. ferrooxidans SW2 iron oxidoreductase FoxE were obtained and the phase problem was solved by Fe SAD at 2.44 Å resolution. FoxE is a protein encoded by the foxEYZ operon of Rhodobacter ferrooxidans SW2 that is involved in Fe II -based anoxygenic photosynthesis (‘photoferrotrophy’). It is thought to reside in the periplasm, where it stimulates light-dependent Fe II oxidation. It contains 259 residues, including two haem c-binding motifs. As no three-dimensional model is available and there is no structure with a similar sequence, crystals of FoxE were produced. They diffracted to 2.44 Å resolution using synchrotron radiation at the Fe edge. The phase problem was solved by SAD using SHELXC/D/E and the experimental maps confirmed the presence of two haems per molecule

  9. Validating Internal Control Genes for the Accurate Normalization of qPCR Expression Analysis of the Novel Model Plant Setaria viridis.

    Directory of Open Access Journals (Sweden)

    Julia Lambret-Frotté

    Full Text Available Employing reference genes to normalize the data generated with quantitative PCR (qPCR can increase the accuracy and reliability of this method. Previous results have shown that no single housekeeping gene can be universally applied to all experiments. Thus, the identification of a suitable reference gene represents a critical step of any qPCR analysis. Setaria viridis has recently been proposed as a model system for the study of Panicoid grasses, a crop family of major agronomic importance. Therefore, this paper aims to identify suitable S. viridis reference genes that can enhance the analysis of gene expression in this novel model plant. The first aim of this study was the identification of a suitable RNA extraction method that could retrieve a high quality and yield of RNA. After this, two distinct algorithms were used to assess the gene expression of fifteen different candidate genes in eighteen different samples, which were divided into two major datasets, the developmental and the leaf gradient. The best-ranked pair of reference genes from the developmental dataset included genes that encoded a phosphoglucomutase and a folylpolyglutamate synthase; genes that encoded a cullin and the same phosphoglucomutase as above were the most stable genes in the leaf gradient dataset. Additionally, the expression pattern of two target genes, a SvAP3/PI MADS-box transcription factor and the carbon-fixation enzyme PEPC, were assessed to illustrate the reliability of the chosen reference genes. This study has shown that novel reference genes may perform better than traditional housekeeping genes, a phenomenon which has been previously reported. These results illustrate the importance of carefully validating reference gene candidates for each experimental set before employing them as universal standards. Additionally, the robustness of the expression of the target genes may increase the utility of S. viridis as a model for Panicoid grasses.

  10. Effect of pH on optimization of photofermentative hydrogen production by co-culture of Rhodobacter sphaeroides-NMBL-02 and Bacillus firmus-NMBL-03.

    Science.gov (United States)

    Pandey, A; Dolly, S; Semwal, D; Pandey, A

    2017-07-31

    Rhodobacter sphaeroides NMBL-02, photosynthetic purple non sulfur (PNS) bacteria and associated Bacillus firmus NMBL-03 were isolated from water sample collected from 15-20 inches beneath the surface of ponds from Northern region of India in modified Sistrom's media (120 ml) containing 3 g/L malate and 1.2 g/L ammonium sulfate. The isolation was done in air tight serum bottles (120 ml) under tungsten bulb (1.8 kLux light intensity) at 30 oC ± 2 oC. The PNS and heterotrophic bacteria associated with the culture was purified by clonal selection method and characterized by 16S rDNA sequencing. The PNS isolate was identified as Rhodobacter sphaeroides NMBL-02 (ID: 1467407, Accession BANKIT: JN256030) and associated heterotroph as Bacillus firmus NMBL-03 (Gene Bank Accession no.: JN 256029). The effect of initial medium pH on optimization of hydrogen production was investigated in batch process. The maximum hydrogen potential and hydrogen production rate was 2310 ± 55 ml/L and 4.75 ml/L culture/h respectively using glutamate (1.7 mmol/L) as nitrogen source and malate (22.38 mmol/L) as carbon source with 76.39% malate conversion efficiency at initial medium pH 5.0. This co-culture has the ability to produce significant amount of hydrogen in the pH range of 5.0 to 10.0 with 76.39% to 35.71% malate conversion respectively.

  11. Linking trace element variations with macronutrients and major cations in marine mussels Mytilus edulis and Perna viridis.

    Science.gov (United States)

    Liu, Fengjie; Wang, Wen-Xiong

    2015-09-01

    Marine mussels have long been used as biomonitors of contamination of trace elements, but little is known about whether variation in tissue trace elements is significantly associated with those of macronutrients and major cations. The authors examined the variability of macronutrients and major cations and their potential relationships with bioaccumulation of trace elements. The authors analyzed the concentrations of macronutrients (C, N, P, S), major cations (Na, Mg, K, Ca), and trace elements (Al, V, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Ba, Pb) in the whole soft tissues of marine mussels Mytilus edulis and Perna viridis collected globally from 21 sites. The results showed that 12% to 84% of the variances in the trace elements was associated with major cations, and the tissue concentration of major cations such as Na and Mg in mussels was a good proxy for ambient seawater concentrations of the major cations. Specifically, bioaccumulation of most of the trace elements was significantly associated with major cations, and the relationships of major cations with trace cations and trace oxyanions were totally opposite. Furthermore, 14% to 69% of the variances in the trace elements were significantly associated with macronutrients. Notably, more than half of the variance in the tissue concentrations of As, Cd, V, Ba, and Pb was explained by the variance in macronutrients in one or both species. Because the tissue macronutrient concentrations were strongly associated with animal growth and reproduction, the observed coupling relationships indicated that these biological processes strongly influenced the bioaccumulation of some trace elements. The present study indicated that simultaneous quantification of macronutrients and major cations with trace elements can improve the interpretation of biomonitoring data. © 2015 SETAC.

  12. Variationas of 210Po Activity in Mussels (Perna viridis) of Samut Sakhon and Its Contribution to Dose Assessment

    International Nuclear Information System (INIS)

    Porntepkasemsan, B; Srisuksawad, K.; Permnamtip, V.

    2014-01-01

    Levels of 210 Po and its effective dose in green mussel (Perna viridis) collected from mussel farming area at the Samut Sakhon province during the period of 2012-2013 are presented. Several parameters including maximum shell length and the physiological performance of mussels using condition index and physical properties of seawater (pH, salinity, conductivity, TDS, DO and cation-anion elements) were measured. Each individual mussel was measured on its maximum shell length which was adopted as size class. The activity concentration of 210Po was determined spectroscopically through its 5.30 MeV alpha particle emission, using 209 Po as an internal tracer. The 210 Po activity concentration in mussels was found to vary between 1.044 and 6.951 Bq.kg-1 wet weight. The 210 Po concentration was higher in smaller sized classes (>35 mm) and lowest in larger ones (40-70 mm). This confirms that larger mussels have lower 210Po levels on a weight basis. The 210 Po body burden (activity per mussel) ranged from 1.035 to 17.183 mBq. Contrary to the 210 Po concentrations, results of the body burden revealed the lower activities in smaller sized mussels (>35 mm) and the higher in larger sized ones (40-70 mm). The type of fluctuations observed with 210 Po concentrations are interpreted as a seasonal effect. Total annual effective 210 Po dose due to mussel consumption was calculated to be in the range of 3.081 to 16.401 μSv. Based on the international guideline, the average dose calculated due to 210 Po in mussels of Samut Sakhon would not pose any significant radiological impact on human health and the mussels are considered to be safe for intake.

  13. Can the shell of the green-lipped mussel Perna viridis from the west coast of Peninsular Malaysia be a potential biomonitoring material for Cd, Pb and Zn?

    Science.gov (United States)

    Yap, C. K.; Ismail, A.; Tan, S. G.; Abdul Rahim, I.

    2003-07-01

    The distributions of Cd, Pb and Zn in the total soft tissues and total shells of the green-lipped mussel Perna viridis were studied in field collected samples as well as from laboratory experimental samples. The results showed that Cd, Pb and Zn were readily accumulated in the whole shells. In mussels sampled from 12 locations along the west coast of Peninsular Malaysia, the ratios of the shell metals to the soft tissue metals were different at each sampling site. Nevertheless, the Cd and Pb levels in the shells were always higher than those in the soft tissues, while the Zn level was higher in the soft tissues than in the shells. In comparison with soft tissues, the degrees of variability for Pb and Cd concentrations in the shells were lower. The lower degrees of variability and significant ( Pwork showed that the pattern of depuration in the shell was not similar to that of the soft tissue although their patterns of accumulation were similar. This indicated that the depuration of heavy metals in the shell was not affected by the physiological conditions of the mussels. Although Zn could be regulated by the soft tissue, the incorporated Cd, Pb and Zn remained in the shell matrices. The present results support the use of the total shell of P. viridis as a potential biomonitoring material for long-term contamination of Cd, Pb and Zn.

  14. Toxic responses of Perna viridis hepatopancreas exposed to DDT, benzo(a)pyrene and their mixture uncovered by iTRAQ-based proteomics and NMR-based metabolomics.

    Science.gov (United States)

    Song, Qinqin; Zhou, Hailong; Han, Qian; Diao, Xiaoping

    2017-11-01

    Dichlorodiphenyltrichloroethane (DDT) and benzo(a)pyrene (BaP) are environmental estrogens (EEs) that are ubiquitous in the marine environment. In the present study, we integrated isobaric tags for relative and absolute quantitation (iTRAQ)-based proteomic and nuclear magnetic resonance (NMR)-based metabolomic approaches to explore the toxic responses of green mussel hepatopancreas exposed to DDT (10μg/L), BaP (10μg/L) and their mixture. The metabolic responses indicated that BaP primarily disturbed energy metabolism and osmotic regulation in the hepatopancreas of the male green mussel P. viridis. Both DDT and the mixture of DDT and BaP perturbed the energy metabolism and osmotic regulation in P. viridis. The proteomic responses revealed that BaP affected the proteins involved in energy metabolism, material transformation, cytoskeleton, stress responses, reproduction and development in green mussels. DDT exposure could change the proteins involved in primary metabolism, stress responses, cytoskeleton and signal transduction. However, the mixture of DDT and BaP altered proteins associated with material and energy metabolism, stress responses, signal transduction, reproduction and development, cytoskeleton and apoptosis. This study showed that iTRAQ-based proteomic and NMR-based metabolomic approaches could effectively elucidate the essential molecular mechanism of disturbances in hepatopancreas function of green mussels exposed to environmental estrogens. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Relationship of leaf oxygen and carbon isotopic composition with transpiration efficiency in the C4 grasses Setaria viridis and Setaria italica.

    Science.gov (United States)

    Ellsworth, Patrick Z; Ellsworth, Patrícia V; Cousins, Asaph B

    2017-06-15

    Leaf carbon and oxygen isotope ratios can potentially provide a time-integrated proxy for stomatal conductance (gs) and transpiration rate (E), and can be used to estimate transpiration efficiency (TE). In this study, we found significant relationships of bulk leaf carbon isotopic signature (δ13CBL) and bulk leaf oxygen enrichment above source water (Δ18OBL) with gas exchange and TE in the model C4 grasses Setaria viridis and S. italica. Leaf δ13C had strong relationships with E, gs, water use, biomass, and TE. Additionally, the consistent difference in δ13CBL between well-watered and water-limited plants suggests that δ13CBL is effective in separating C4 plants with different availability of water. Alternatively, the use of Δ18OBL as a proxy for E and TE in S. viridis and S. italica was problematic. First, the oxygen isotopic composition of source water, used to calculate leaf water enrichment (Δ18OLW), was variable with time and differed across water treatments. Second, water limitations changed leaf size and masked the relationship of Δ18OLW and Δ18OBL with E. Therefore, the data collected here suggest that δ13CBL but not Δ18OBL may be an effective proxy for TE in C4 grasses. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  16. Extracts from Cladiella australis, Clavularia viridis and Klyxum simplex (Soft Corals are Capable of Inhibiting the Growth of Human Oral Squamous Cell Carcinoma Cells

    Directory of Open Access Journals (Sweden)

    Guey-Horng Wang

    2008-11-01

    Full Text Available Many biomedical products have already been obtained from marine organisms. In order to search more therapeutic drugs against cancer, this study demonstrates the cytotoxicity effects of Cladiella australis, Clavularia viridis and Klyxum simplex extractson human oral squamous cell carcinoma (SCC4, SCC9 and SCC25 cells using cell adhesion and cell viability assay. The morphological alterations in SCCs cells after treatment with three extracts, such as typical nuclear condensation, nuclear fragmentation and apoptotic bodies of cells were demonstrated by Hoechst stain. Flow cytometry indicated that three extracts sensitized SCC25 cells in the G0/G1 and S-G2/M phases with a concomitant significantly increased sub-G1 fraction, indicating cell death by apoptosis. This apoptosis process was accompanied by activation of caspase-3 expression after SCC25 cells were treated with three extracts. Thereby, it is possible that extracts of C. australis, C. viridis and K. simplex cause apoptosis of SCCs and warrant further research investigating the possible anti-oral cancer compounds in these soft corals.

  17. Impact of cadmium on forage kale (Brassica oleracea var. viridis cv "Prover") after 3-,10- and 56-day exposure to a Cd-spiked field soil.

    Science.gov (United States)

    Bernard, Fabien; Dumez, Sylvain; Lemière, Sébastien; Platel, Anne; Nesslany, Fabrice; Deram, Annabelle; Vandenbulcke, Franck; Cuny, Damien

    2018-03-15

    Cadmium (Cd) is a highly toxic element for living organisms and is widespread in metal-contaminated soils. As organisms which can grow up on these polluted areas, plants have some protection mechanisms against Cd issues. Among the plant kingdom, the Brassicaceae family includes species which are known to be able to tolerate and accumulate Cd in their tissues. In this study, Brassica oleracea var. viridis cv "Prover" was exposed to a range of artificially Cd-contaminated soils (from 2.5 up to 20 mg kg -1 ) during 3, 10, and 56 days and the effects on life traits, photosynthesis activity, antioxidant enzymatic activities were studied. Metal accumulation was quantified, as well as DNA damage, by means of the comet assay and immunodetection of 8-OHdG levels. Globally, B. oleracea was relatively tolerant to those Cd exposures. However, comet assay and detection of 8-OHdG revealed some DNA damage but which are not significant. According to metal accumulation analysis, B. oleracea var. viridis cv Prover could be a good candidate for alternative growing in contaminated areas.

  18. Bioreduction of trivalent aurum to nano-crystalline gold particles by active and inactive cells and cell-free extract of Aspergillus oryzae var. viridis

    International Nuclear Information System (INIS)

    Binupriya, A.R.; Sathishkumar, M.; Vijayaraghavan, K.; Yun, S.-I.

    2010-01-01

    Bioreduction efficacy of both active (AB) and inactive (IB) cells/biomass of Aspergillus oryzae var. viridis and their respective cell-free extracts (ACE and ICE) to convert trivalent aurum to gold nanoparticles were tested in the present study. Strong plasmon resonance of gold nanoparticles was observed between 540 and 560 nm in the samples obtained from AB, IB, ACE and ICE. Transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD) were performed to examine the formation of gold nanoparticles. Comparing all four forms of A. oryzae var. viridis, ICE showed high gold nanoparticle productivity. The nanoparticles formed were quite uniform in shape and ranged in size from 10 to 60 nm. In addition some triangle, pentagon and hexagon-shaped nanoplates with size range of 30-400 nm were also synthesized especially at lower pH. Organics from the inactive cells are believed to be responsible for reduction of trivalent aurum to nano-sized gold particles. Organic content of the ICE was found to be double the amount of ACE. High productivity of gold nanoparticles by metabolic-independent process opens up an interesting area of nanoparticle synthesis using waste fungal biomass from industries.

  19. Bioreduction of trivalent aurum to nano-crystalline gold particles by active and inactive cells and cell-free extract of Aspergillus oryzae var. viridis

    Energy Technology Data Exchange (ETDEWEB)

    Binupriya, A.R. [Department of Food Science and Technology, College of Agriculture and Life Science, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Sathishkumar, M., E-mail: cvemuthu@nus.edu.sg [Singapore-Delft Water Alliance, National University of Singapore, 2 Engineering Drive 2, Singapore 117577 (Singapore); Vijayaraghavan, K. [Singapore-Delft Water Alliance, National University of Singapore, 2 Engineering Drive 2, Singapore 117577 (Singapore); Yun, S.-I., E-mail: siyun@chonbuk.ac.kr [Department of Food Science and Technology, College of Agriculture and Life Science, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

    2010-05-15

    Bioreduction efficacy of both active (AB) and inactive (IB) cells/biomass of Aspergillus oryzae var. viridis and their respective cell-free extracts (ACE and ICE) to convert trivalent aurum to gold nanoparticles were tested in the present study. Strong plasmon resonance of gold nanoparticles was observed between 540 and 560 nm in the samples obtained from AB, IB, ACE and ICE. Transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD) were performed to examine the formation of gold nanoparticles. Comparing all four forms of A. oryzae var. viridis, ICE showed high gold nanoparticle productivity. The nanoparticles formed were quite uniform in shape and ranged in size from 10 to 60 nm. In addition some triangle, pentagon and hexagon-shaped nanoplates with size range of 30-400 nm were also synthesized especially at lower pH. Organics from the inactive cells are believed to be responsible for reduction of trivalent aurum to nano-sized gold particles. Organic content of the ICE was found to be double the amount of ACE. High productivity of gold nanoparticles by metabolic-independent process opens up an interesting area of nanoparticle synthesis using waste fungal biomass from industries.

  20. Modification of trace metal accumulation in the green mussel Perna viridis by exposure to Ag, Cu, and Zn

    International Nuclear Information System (INIS)

    Shi Dalin; Wang Wenxiong

    2004-01-01

    To examine the Cd, Hg, Ag, and Zn accumulation in the green mussel Perna viridis affected by previous exposure to Cu, Ag, or Zn, the dietary metal assimilation efficiency (AE) and the uptake rate from the dissolved phase were quantified. The mussel's filtration rate, metallothionein (MT) concentration, and metal tissue burden as well as the metal subcellular partitioning were also determined to illustrate the potential mechanisms underlying the influences caused by one metal pre-exposure on the bioaccumulation of the other metals. The green mussels were pre-exposed to Cu, Ag, or Zn for different periods (1-5 weeks) and the bioaccumulation of Cd, Hg, Ag, and Zn were concurrently determined. Pre-exposure to the three metals did not result in any significant increase in MT concentration in the green mussels. Ag concentration in the insoluble fraction increased with increasing Ag exposure period and Ag ambient concentration. Our data indicated that Cd assimilation were not influenced by the mussel's pre-exposure to the three metals (Cu, Ag, and Zn), but its dissolved uptake was depressed by Ag and Zn exposure. Although Hg assimilation from food was not affected by the metal pre-exposure, its influx rate from solution was generally inhibited by the exposure to Cu, Ag, and Zn. Ag bioaccumulation was affected the most obviously, in which its AE increased with increasing Ag tissue concentration, and its dissolved uptake decreased with increasing tissue concentrations of Ag and Cu. As an essential metal, Zn bioaccumulation remained relatively stable following the metal pre-exposure, suggesting the regulatory ability of Zn uptake in the mussels. Zn AE was not affected by metal pre-exposure, but its dissolved uptake was depressed by Ag and Zn pre-exposure. All these results indicated that the influences of one metal pre-exposure on the bioaccumulation of other metals were metal-specific due to the differential binding and toxicity of metals to the mussels. Such factors should

  1. The SOS Response Master Regulator LexA Regulates the Gene Transfer Agent of Rhodobacter capsulatus and Represses Transcription of the Signal Transduction Protein CckA.

    Science.gov (United States)

    Kuchinski, Kevin S; Brimacombe, Cedric A; Westbye, Alexander B; Ding, Hao; Beatty, J Thomas

    2016-02-01

    The gene transfer agent of Rhodobacter capsulatus (RcGTA) is a genetic exchange element that combines central aspects of bacteriophage-mediated transduction and natural transformation. RcGTA particles resemble a small double-stranded DNA bacteriophage, package random ∼4-kb fragments of the producing cell genome, and are released from a subpopulation (SOS response in many bacteria, as a regulator of RcGTA activity. Deletion of the lexA gene resulted in the abolition of detectable RcGTA production and an ∼10-fold reduction in recipient capability. A search for SOS box sequences in the R. capsulatus genome sequence identified a number of putative binding sites located 5' of typical SOS response coding sequences and also 5' of the RcGTA regulatory gene cckA, which encodes a hybrid histidine kinase homolog. Expression of cckA was increased >5-fold in the lexA mutant, and a lexA cckA double mutant was found to have the same phenotype as a ΔcckA single mutant in terms of RcGTA production. The data indicate that LexA is required for RcGTA production and maximal recipient capability and that the RcGTA-deficient phenotype of the lexA mutant is largely due to the overexpression of cckA. This work describes an unusual phenotype of a lexA mutant of the alphaproteobacterium Rhodobacter capsulatus in respect to the phage transduction-like genetic exchange carried out by the R. capsulatus gene transfer agent (RcGTA). Instead of the expected SOS response characteristic of prophage induction, this lexA mutation not only abolishes the production of RcGTA particles but also impairs the ability of cells to receive RcGTA-borne genes. The data show that, despite an apparent evolutionary relationship to lambdoid phages, the regulation of RcGTA gene expression differs radically. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  2. The mutation of carotenoids affects the energy transfer in LH2 light harvesting complexes from Rhodobacter sphaeroides 601 at room temperature

    International Nuclear Information System (INIS)

    Liu Weimin; Liu Yuan; Guo Lijun; Xu Chunhe; Qian Shixiong

    2006-01-01

    Energy transfer in two kinds of peripheral antenna complexes LH2 from Rhodobacter sphaeroides 601 was studied by absorption, fluorescence emission, time-resolved fluorescence and femtosecond transient absorption spectroscopy at room temperature. These two complexes are LH2 (RS601) and green carotenoid mutated LH2 (GM309). The obtained results demonstrate that: (a) compared with spheroidenes, which have ten carbon-carbon double bonds in native RS601, carotenoids in GM309 were identified as containing neurosporenes with nine carbon-carbon double bonds, which show a significant blue shift of ∼20 nm in the three absorption peaks because of the higher energy levels of neurosporene than those of spheroidene, (b) the higher energy levels of neurosporene in GM309 induce a lower B800 → B850 energy transfer rate and efficiency as compared to that in RS601 resulting from the relatively higher band gap between the donor of B800 and the bridge of the carotenoids (c) the same lifetime of the B850 excited singlet state is observed in these two LH2 complexes

  3. Dietary Karaya Saponin and Rhodobacter capsulatus Exert Hypocholesterolemic Effects by Suppression of Hepatic Cholesterol Synthesis and Promotion of Bile Acid Synthesis in Laying Hens

    Directory of Open Access Journals (Sweden)

    Sadia Afrose

    2010-01-01

    Full Text Available This study was conducted to elucidate the mechanism underlying the hypolipidemic action of karaya saponin or Rhodobacter (R. capsulatus. A total of 40 laying hens (20-week-old were assigned into four dietary treatment groups and fed a basal diet (as a control or basal diets supplemented with either karaya saponin, R. capsulatus, or both for 60 days. The level of serum low-density-lipoprotein cholesterol and the levels of cholesterol and triglycerides in the serum, liver, and egg yolk were reduced by all the supplementations (<.05. Liver bile acid concentration and fecal concentrations of cholesterol, triacylglycerol, and bile acid were simultaneously increased by the supplementation of karaya saponin, R. capsulatus, and the combination of karaya saponin and R. capsulatus (<.05. The supplementation of karaya saponin, R. capsulatus, and the combination of karaya saponin and R. capsulatus suppressed the incorporation of 14C from 1-14C-palmitic acid into the fractions of total lipids, phospholipids, triacylglycerol, and cholesterol in the liver in vitro (<.05. These findings suggest that the hypocholesterolemic effects of karaya saponin and R. capsulatus are caused by the suppression of the cholesterol synthesis and the promotion of cholesterol catabolism in the liver.

  4. Resonance Raman and surface-enhanced resonance Raman spectra of LH2 antenna complex from Rhodobacter sphaeroides and Ectothiorhodospira sp. excited in the Qx and Qy transitions.

    Science.gov (United States)

    Chumanov, G; Picorel, R; Ortiz de Zarate, I; Cotton, T M; Seibert, M

    2000-05-01

    Well-resolved vibrational spectra of LH2 complex isolated from two photosynthetic bacteria, Rhodobacter sphaeroides and Ectothiorhodospira sp., were obtained using surface-enhanced resonance Raman scattering (SERRS) exciting into the Qx and the Qy transitions of bacteriochlorophyll a. High-quality SERRS spectra in the Qy region were accessible because the strong fluorescence background was quenched near the roughened Ag surface. A comparison of the spectra obtained with 590 nm and 752 nm excitation in the mid- and low-frequency regions revealed spectral differences between the two LH2 complexes as well as between the LH2 complexes and isolated bacteriochlorophyll a. Because peripheral modes of pigments contribute mainly to the low-frequency spectral region, frequencies and intensities of many vibrational bands in this region are affected by interactions with the protein. The results demonstrate that the microenvironment surrounding the pigments within the two LH2 complexes is somewhat different, despite the fact that the complexes exhibit similar electronic absorption spectra. These differences are most probably due to specific pigment-pigment and pigment-protein interactions within the LH2 complexes, and the approach might be useful for addressing subtle static and dynamic structural variances between pigment-protein complexes from different sources or in complexes altered chemically or genetically.

  5. Nicotinamide nucleotide transhydrogenase from Rhodobacter capsulatus; the H+/H- ratio and the activation state of the enzyme during reduction of acetyl pyridine adenine dinucleotide.

    Science.gov (United States)

    Palmer, T; Jackson, J B

    1992-02-21

    Chromatophores from Rhodobacter capsulatus were incubated in the dark with NADPH and acetylpyridineadenine dinucleotide (AcPdAD+) in the presence of different concentrations of myxothiazol. The transhydrogenase activity was monitored until an appropriate mass action ratio, [AcPdAD+][NADPH]/[AcPdADH][NADP+], was reached. The sample was then illuminated and the initial rate of either AcPdAD+ reduction by NADPH or AcPdADH oxidation by NADP+ was recorded. The ratio of H+ translocated per H- equivalent transferred by transhydrogenase was calculated from the value of the membrane potential (delta pH = 0) at which illumination caused no net reaction in either direction. The mean value for the H+/H- ratio was 0.55. At greater values of [AcPdAD+][NADPH]/[AcPdADH][NADP+] than were employed in the above experiments and over a wider range of concentrations of myxothiazol, it was found that incremental increases in the membrane potential always gave rise to a decrease, never an increase in the rate of AcPdAD+ reduction. In contrast to the H(+)-ATP synthase, there is no evidence of any activation/deactivation of H(+)-transhydrogenase by the protonmotive force.

  6. Enhancement of phototrophic hydrogen production by Rhodobacter sphaeroides ZX-5 using a novel strategy - shaking and extra-light supplementation approach

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xu; Wang, Yong-Hong; Zhang, Si-Liang; Chu, Ju; Zhang, Ming; Huang, Ming-Zhi; Zhuang, Ying-Ping [State Key Laboratory of Bioreactor Engineering, P.O. Box 329, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237 (China)

    2009-12-15

    Biohydrogen has gained attention due to its potential as a sustainable alternative to conventional methods for hydrogen production. In this study, the effect of light intensity as well as cultivation method (standing- and shaking-culture) on the cell growth and hydrogen production of Rhodobacter sphaeroides ZX-5 were investigated in 38-ml anaerobic photobioreactor with RCVBN medium. Thus, a novel shaking and extra-light supplementation (SELS) approach was developed to enhance the phototrophic H{sub 2} production by R. sphaeroides ZX-5 using malate as the sole carbon source. The optimum illumination condition for shaking-culture by strain ZX-5 increased to 7000-8000 lux, markedly higher than that for standing-culture (4000-5000 lux). Under shaking and elevated illumination (7000-8000 lux), the culture was effective in promoting photo-H{sub 2} production, resulting in a 59% and 56% increase of the maximum and average hydrogen production rate, respectively, in comparison with the culture under standing and 4000-5000 lux conditions. The highest hydrogen-producing rate of 165.9 ml H{sub 2}/l h was observed under the application of SELS approach. To our knowledge, this record is currently the highest hydrogen production rate of non-immobilized purple non-sulphur (PNS) bacteria. This optimal performance of photo-H{sub 2} production using SELS approach is a favorable choice of sustainable and economically feasible strategy to improve phototrophic H{sub 2} production efficiency. (author)

  7. Exploitation of dark fermented effluent of cheese whey by co-culture of Rhodobacter sphaeroides and Bacillus firmus for photo-hydrogen production.

    Science.gov (United States)

    Pandey, A; Pandey, A

    2017-07-31

    In this study photo-hydrogen production from cheese whey dark fermentation (DF) effluent by the co-culture of Rhodobacter sphaeroides -NMBL-01 and Bacillus firmus - NMBL-03 has been reported. The effect of pH, initial chemical oxygen demand (COD) and the concentration effect of FeSO4.7H2O on photo-hydrogen production have been investigated. The end products of dark fermentation effluent of cheese whey were mainly comprised of soluble organic acids, i.e. butyric acid and lactic acid. The batch process was carried out under light intensity of 2.5 kLux at 32 ± 2oC without any addition of extra carbon and nitrogen source. The single parameter optimization studies revealed optimum pH 6.5, initial COD 4.71 g/L and supplementation of Fe2+ concentration 100 mg/L. The maximum cumulative hydrogen production and yield were found to be 469 ± 45.8 ml H2/L and 146.56 ± 14.31 ml H2/g COD reduced (67.9% reduction in COD) respectively. The mutual interactions among the process parameters were also investigated by three factorial Box-Behnken design of response surface methodology. The optimized experimental values were found concurrent with the calculated values obtained from the theoretical model.

  8. Effect of light-dark cycles on hydrogen and poly-β-hydroxybutyrate production by a photoheterotrophic culture and Rhodobacter capsulatus using a dark fermentation effluent as substrate.

    Science.gov (United States)

    Montiel Corona, Virginia; Le Borgne, Sylvie; Revah, Sergio; Morales, Marcia

    2017-02-01

    A Rhodobacter capsulatus strain and a photoheterotrophic culture (IZT) were cultivated to produce hydrogen under different light-dark cycles. A dark fermentation effluent (DFE) was used as substrate. It was found that IZT culture had an average cumulative hydrogen production (Paccum H 2 ) of 1300±43mLH 2 L -1 under continuous illumination and light-dark cycles of 30 or 60min. In contrast, R. capsulatus reduced its Paccum H 2 by 20% under 30:30min light-dark cycles, but tripled its poly-β-hydroxybutyrate (PHB) content (308±2mgPHB gdw -1 ) compared to continuous illumination. The highest PHB content by IZT culture was 178±10mgPHB gdw -1 under 15:15min light-dark cycles. PCR-DGGE analysis revealed that the IZT culture was mainly composed of Rhodopseudomonas palustris identified with high nucleotide similarity (99%). The evaluated cultures might be used for hydrogen and PHB production. They might provide energy savings by using light-dark cycles and DFE valorization. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Effects of the cryptochrome CryB from Rhodobacter sphaeroides on global gene expression in the dark or blue light or in the presence of singlet oxygen.

    Directory of Open Access Journals (Sweden)

    Sebastian Frühwirth

    Full Text Available Several regulators are controlling the formation of the photosynthetic apparatus in the facultatively photosynthetic bacterium Rhodobacter sphaeroides. Among the proteins affecting photosynthesis gene expression is the blue light photoreceptor cryptochrome CryB. This study addresses the effect of CryB on global gene expression. The data reveal that CryB does not only influence photosynthesis gene expression but also genes for the non-photosynthetic energy metabolism like citric acid cycle and oxidative phosphorylation. In addition several genes involved in RNA processing and in transcriptional regulation are affected by a cryB deletion. Although CryB was shown to undergo a photocycle it does not only affect gene expression in response to blue light illumination but also in response to singlet oxygen stress conditions. While there is a large overlap in these responses, some CryB-dependent effects are specific for blue-light or photooxidative stress. In addition to protein-coding genes some genes for sRNAs show CryB-dependent expression. These findings give new insight into the function of bacterial cryptochromes and demonstrate for the first time a function in the oxidative stress response.

  10. Potential of Rhodobacter capsulatus Grown in Anaerobic-Light or Aerobic-Dark Conditions as Bioremediation Agent for Biological Wastewater Treatments

    Directory of Open Access Journals (Sweden)

    Stefania Costa

    2017-02-01

    Full Text Available The use of microorganisms to clean up wastewater provides a cheaper alternative to the conventional treatment plant. The efficiency of this method can be improved by the choice of microorganism with the potential of removing contaminants. One such group is photosynthetic bacteria. Rhodobacter capsulatus is a purple non-sulfur bacterium (PNSB found to be capable of different metabolic activities depending on the environmental conditions. Cell growth in different media and conditions was tested, obtaining a concentration of about 108 CFU/mL under aerobic-dark and 109 CFU/mL under anaerobic-light conditions. The biomass was then used as a bioremediation agent for denitrification and nitrification of municipal wastewater to evaluate the potential to be employed as an additive in biological wastewater treatment. Inoculating a sample of mixed liquor withdrawn from the municipal wastewater treatment plant with R. capsulatus grown in aerobic-dark and anaerobic-light conditions caused a significant decrease of N-NO3 (>95%, N-NH3 (70% and SCOD (soluble chemical oxygen demand (>69%, independent of the growth conditions. A preliminary evaluation of costs indicated that R. capsulatus grown in aerobic-dark conditions could be more convenient for industrial application.

  11. Chronic Exposure to Rhodobacter Sphaeroides Extract Lycogen™ Prevents UVA-Induced Malondialdehyde Accumulation and Procollagen I Down-Regulation in Human Dermal Fibroblasts

    Science.gov (United States)

    Yang, Tsai-Hsiu; Lai, Ying-Hsiu; Lin, Tsuey-Pin; Liu, Wen-Sheng; Kuan, Li-Chun; Liu, Chia-Chyuan

    2014-01-01

    UVA contributes to the pathogenesis of skin aging by downregulation of procollagen I content and induction of matrix metalloproteinase (MMP)-associated responses. Application of antioxidants such as lycopene has been demonstrated as a convenient way to achieve protection against skin aging. Lycogen™, derived from the extracts of Rhodobacter sphaeroides, exerts several biological effects similar to that of lycopene whereas most of its anti-aging efficacy remains uncertain. In this study, we attempted to examine whether Lycogen™ could suppress malondialdehyde (MDA) accumulation and restore downregulated procollagen I expression induced by UVA exposure. In human dermal fibroblasts Hs68 cells, UVA repressed cell viability and decreased procollagen I protein content accompanied with the induction of MMP-1 and MDA accumulation. Remarkably, incubation with 50 μM Lycogen™ for 24 h ameliorated UVA-induced cell death and restored UVA-induced downregulation of procollagen in a dose-related manner. Lycogen™ treatment also prevented the UVA-induced MMP-1 upregulation and intracellular MDA generation in Hs68 cells. Activation of NFκB levels, one of the downstream events induced by UVA irradiation and MMP-1 induction, were also prevented by Lycogen™ administration. Taken together, our findings demonstrate that Lycogen™ may be an alternative agent that prevents UVA-induced skin aging and could be used in cosmetic and pharmaceutical applications. PMID:24463291

  12. Removal of the effect of ammonium on the regulation of nitrogenase enzyme in Rhodobacter capsulatus DSM1710 for improved hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Pekgoez, Guelsah; Guenduez, Ufuk [Middle East Technical Univ. (Turkey). Dept. of Biology; Eroglu, Inci [Middle East Technical Univ. (Turkey). Dept. of Chemical Engineering; Rakhely, Gabor [Szeged Univ. (Hungary). Dept. of Biotechnology

    2010-07-01

    Photofermentative biohydrogen production by purple non-sulfur (PNS) bacteria is a renewable and clean way of producing hydrogen. Hydrogen production by PNS bacteria, Rhodobacter capsulatus, is mediated mainly by nitrogenases, which primarily fix molecular nitrogen to ammonium and produce hydrogen as byproduct. The reaction catalyzed by nitrogenases requires a lot of energy. Hence, there is a complex regulation on nitrogenase enzyme complex, consequently, on hydrogen production. Whenever ammonium, which is the end product of nitrogen fixation reaction, is found in the environment, hydrogen production stops. GlnB and GlnK proteins are the critical regulatory proteins in ammonium dependent regulation of the nitrogenase gene expression. In this study, the aim is to release the ammonium regulation on nitrogenase enzyme by inactivating glnB and glnK genes. For this purpose, relevant recombinant vectors were constructed; R.capsulatus glnB- strain was obtained. The double R.capsulatus glnB{sup -}glnK{sup -} strain, able to produce hydrogen independent of ammonium concentration of the environment is to be obtained. (orig.)

  13. Quenching Capabilities of Long-Chain Carotenoids in Light-Harvesting-2 Complexes from Rhodobacter sphaeroides with an Engineered Carotenoid Synthesis Pathway.

    Science.gov (United States)

    Dilbeck, Preston L; Tang, Qun; Mothersole, David J; Martin, Elizabeth C; Hunter, C Neil; Bocian, David F; Holten, Dewey; Niedzwiedzki, Dariusz M

    2016-06-23

    Six light-harvesting-2 complexes (LH2) from genetically modified strains of the purple photosynthetic bacterium Rhodobacter (Rb.) sphaeroides were studied using static and ultrafast optical methods and resonance Raman spectroscopy. These strains were engineered to incorporate carotenoids for which the number of conjugated groups (N = NC═C + NC═O) varies from 9 to 15. The Rb. sphaeroides strains incorporate their native carotenoids spheroidene (N = 10) and spheroidenone (N = 11), as well as longer-chain analogues including spirilloxanthin (N = 13) and diketospirilloxantion (N = 15) normally found in Rhodospirillum rubrum. Measurements of the properties of the carotenoid first singlet excited state (S1) in antennas from the Rb. sphaeroides set show that carotenoid-bacteriochlorophyll a (BChl a) interactions are similar to those in LH2 complexes from various other bacterial species and thus are not significantly impacted by differences in polypeptide composition. Instead, variations in carotenoid-to-BChl a energy transfer are primarily regulated by the N-determined energy of the carotenoid S1 excited state, which for long-chain (N ≥ 13) carotenoids is not involved in energy transfer. Furthermore, the role of the long-chain carotenoids switches from a light-harvesting supporter (via energy transfer to BChl a) to a quencher of the BChl a S1 excited state B850*. This quenching is manifested as a substantial (∼2-fold) reduction of the B850* lifetime and the B850* fluorescence quantum yield for LH2 housing the longest carotenoids.

  14. A Single Transcriptome of a Green Toad (Bufo viridis Yields Candidate Genes for Sex Determination and -Differentiation and Non-Anonymous Population Genetic Markers.

    Directory of Open Access Journals (Sweden)

    Jörn F Gerchen

    Full Text Available Large genome size, including immense repetitive and non-coding fractions, still present challenges for capacity, bioinformatics and thus affordability of whole genome sequencing in most amphibians. Here, we test the performance of a single transcriptome to understand whether it can provide a cost-efficient resource for species with large unknown genomes. Using RNA from six different tissues from a single Palearctic green toad (Bufo viridis specimen and Hiseq2000, we obtained 22,5 Mio reads and publish >100,000 unigene sequences. To evaluate efficacy and quality, we first use this data to identify green toad specific candidate genes, known from other vertebrates for their role in sex determination and differentiation. Of a list of 37 genes, the transcriptome yielded 32 (87%, many of which providing the first such data for this non-model anuran species. However, for many of these genes, only fragments could be retrieved. In order to allow also applications to population genetics, we further used the transcriptome for the targeted development of 21 non-anonymous microsatellites and tested them in genetic families and backcrosses. Eleven markers were specifically developed to be located on the B. viridis sex chromosomes; for eight markers we can indeed demonstrate sex-specific transmission in genetic families. Depending on phylogenetic distance, several markers, which are sex-linked in green toads, show high cross-amplification success across the anuran phylogeny, involving nine systematic anuran families. Our data support the view that single transcriptome sequencing (based on multiple tissues provides a reliable genomic resource and cost-efficient method for non-model amphibian species with large genome size and, despite limitations, should be considered as long as genome sequencing remains unaffordable for most species.

  15. Neuro-endocrine effects of aqueous extract of Amaranthus viridis (Linn. leaf in male Wistar rat model of cyclophosphamide-induced reproductive toxicity

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    Oladele Abiodun Ayoka

    Full Text Available Cyclophosphamide (CP is a widely used cytotoxic alkylating agent with antitumor and immunosuppressant properties that is associated with various forms of reproductive toxicity. The significance of natural antioxidants of plant origin should be explored, especially in a world with increasing incidence of patients in need of chemotherapy. The neuro-endocrine effects of aqueous extract of Amaranthus viridis (Linn. leaf (AEAVL in Wistar rats with CP-induced reproductive toxicity was determined. Forty rats were used for this study such that graded doses of the extract were administered following CP-induced reproductive toxicity and comparisons were made against control, toxic and standard (vitamin E groups at p < 0.05. The synthetic drugs (CP, 65 mg/kg i.p. for 5 days; Vitamin E, 100 mg/kg p.o. for 30 days as well as the extract (100, 200 and 400 mg/kg p.o. for 30 days were administered to the rats at 0.2 mL/100 g. CP induced reproductive toxicity as evidenced by significantly lowered levels of FSH, LH and testosterone, perturbation of sperm characterization, deleterious disruptions of the antioxidant system as evidenced by decreased levels of GSH as well as elevation of TBARS activity. Histopathological examination showed hemorrhagic lesions with scanty and hypertrophied parenchymal cells in the pituitary while the testis showed ballooned seminiferous tubules with loosed connective tissues and vacuolation of testicular interstitium. These conditions were significantly reversed (p < 0.05 following administration of the graded doses of the extract. It was, therefore, concluded that AEAVL could potentially be a therapeutic choice in patients with CP-induced neuro-endocrine dysfunction and reproductive toxicity. Keywords: Cyclophosphamide, Neuro-endocrine dysfunction, Reproductive toxicity, Rats, Amaranthus viridis

  16. Toxic effects of male Perna viridis gonad exposed to BaP, DDT and their mixture: A metabolomic and proteomic study of the underlying mechanism.

    Science.gov (United States)

    Song, Qinqin; Zheng, Pengfei; Qiu, Liguo; Jiang, Xiu; Zhao, Hongwei; Zhou, Hailong; Han, Qian; Diao, Xiaoping

    2016-01-05

    Benzo(a)pyrene and dichlorodiphenyltrichloroethane are typical persistent organic pollutants, and also the widespread environmental estrogens with known toxicity towards green mussels Perna viridis. In this study, the toxicological effects of BaP and DDT and their mixture were assessed in green mussel gonads using proteomic and metabolomic approaches. Metabolomics by NMR spectroscopy revealed that BaP did not show obvious metabolite changes in the gonad of male green mussel. DDT mainly caused some disturbance of osmotic regulation and energy metabolism by changing BCAAs, alanine, threonine, arginine, etc., unknown metabolite (3.53 ppm), glycine, homarine and ATP at different levels. However, the mixture of BaP and DDT mainly caused some disturbance in osmotic regulation and energy metabolism by differentially altering branched chain amino acids, glutamate, alanine, arginine, unknown metabolite (3.53 ppm), glycine, 4-aminobutyrate, dimethylglycine, homarine and ATP. The results suggest that DDT alone may cause most of metabolites changes in the mixture exposed male mussel gonad, and the results also show that the male P. viridis gonad was more sensitive to DDT than BaP exposures. Proteomic study showed that BaP, DDT and their mixture may have different modes of action. Proteomic responses revealed that BaP induced signal transduction, oxidative stress, spermatogenesis, etc. in the male green mussel gonad; whereas DDT exposure altered proteins that were associated with signal transduction, oxidative stress, cytoskeleton and cell structure, cellular organization, energy metabolism, etc. However, the mixture of BaP and DDT affected proteins related to cytoskeleton and cell structure, oxidative stress, cellular organization, etc. This research demonstrated that metabolomic and proteomic approaches could better elucidate the underlying mechanism of environmental pollutants gonad toxicity. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  17. Application of a novel alkali-tolerant thermostable DyP-type peroxidase from Saccharomonospora viridis DSM 43017 in biobleaching of eucalyptus kraft pulp.

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    Wangning Yu

    Full Text Available Saccharomonospora viridis is a thermophilic actinomycete that may have biotechnological applications because of its dye decolorizing activity, though the enzymatic oxidative system responsible for this activity remains elusive. Bioinformatic analysis revealed a DyP-type peroxidase gene in the genome of S. viridis DSM 43017 with sequence similarity to peroxidase from dye-decolorizing microbes. This gene, svidyp, consists of 1,215 bp encoding a polypeptide of 404 amino acids. The gene encoding SviDyP was cloned, heterologously expressed in Escherichia coli, and then purified. The recombinant protein could efficiently decolorize several triarylmethane dyes, anthraquinonic and azo dyes under neutral to alkaline conditions. The optimum pH and temperature for SviDyP was pH 7.0 and 70°C, respectively. Compared with other DyP-type peroxidases, SviDyP was more active at high temperatures, retaining>63% of its maximum activity at 50-80°C. It also showed broad pH adaptability (>35% activity at pH 4.0-9.0 and alkali-tolerance (>80% activity after incubation at pH 5-10 for 1 h at 37°C, and was highly thermostable (>60% activity after incubation at 70°C for 2 h at pH 7.0. SviDyP had an accelerated action during the biobleaching of eucalyptus kraft pulp, resulting in a 21.8% reduction in kappa number and an increase of 2.98% (ISO in brightness. These favorable properties make SviDyP peroxidase a promising enzyme for use in the pulp and paper industries.

  18. Electron spin relaxation enhancement measurements of interspin distances in human, porcine, and Rhodobacter electron transfer flavoprotein-ubiquinone oxidoreductase (ETF-QO).

    Science.gov (United States)

    Fielding, Alistair J; Usselman, Robert J; Watmough, Nicholas; Simkovic, Martin; Frerman, Frank E; Eaton, Gareth R; Eaton, Sandra S

    2008-02-01

    Electron transfer flavoprotein-ubiquinone oxidoreductase (ETF-QO) is a membrane-bound electron transfer protein that links primary flavoprotein dehydrogenases with the main respiratory chain. Human, porcine, and Rhodobacter sphaeroides ETF-QO each contain a single [4Fe-4S](2+,1+) cluster and one equivalent of FAD, which are diamagnetic in the isolated enzyme and become paramagnetic on reduction with the enzymatic electron donor or with dithionite. The anionic flavin semiquinone can be reduced further to diamagnetic hydroquinone. The redox potentials for the three redox couples are so similar that it is not possible to poise the proteins in a state where both the [4Fe-4S](+) cluster and the flavoquinone are fully in the paramagnetic form. Inversion recovery was used to measure the electron spin-lattice relaxation rates for the [4Fe-4S](+) between 8 and 18K and for semiquinone between 25 and 65K. At higher temperatures the spin-lattice relaxation rates for the [4Fe-4S](+) were calculated from the temperature-dependent contributions to the continuous wave linewidths. Although mixtures of the redox states are present, it was possible to analyze the enhancement of the electron spin relaxation of the FAD semiquinone signal due to dipolar interaction with the more rapidly relaxing [4Fe-4S](+) and obtain point-dipole interspin distances of 18.6+/-1A for the three proteins. The point-dipole distances are within experimental uncertainty of the value calculated based on the crystal structure of porcine ETF-QO when spin delocalization is taken into account. The results demonstrate that electron spin relaxation enhancement can be used to measure distances in redox poised proteins even when several redox states are present.

  19. Functional characteristics of spirilloxanthin and keto-bearing Analogues in light-harvesting LH2 complexes from Rhodobacter sphaeroides with a genetically modified carotenoid synthesis pathway.

    Science.gov (United States)

    Niedzwiedzki, Dariusz M; Dilbeck, Preston L; Tang, Qun; Mothersole, David J; Martin, Elizabeth C; Bocian, David F; Holten, Dewey; Hunter, C Neil

    2015-01-01

    Light-harvesting 2 (LH2) complexes from a genetically modified strain of the purple photosynthetic bacterium Rhodobacter (Rba.) sphaeroides were studied using static and ultrafast optical methods and resonance Raman spectroscopy. Carotenoid synthesis in the Rba. sphaeroides strain was engineered to redirect carotenoid production away from spheroidene into the spirilloxanthin synthesis pathway. The strain assembles LH2 antennas with substantial amounts of spirilloxanthin (total double-bond conjugation length N=13) if grown anaerobically and of keto-bearing long-chain analogs [2-ketoanhydrorhodovibrin (N=13), 2-ketospirilloxanthin (N=14) and 2,2'-diketospirilloxanthin (N=15)] if grown semi-aerobically (with ratios that depend on growth conditions). We present the photophysical, electronic, and vibrational properties of these carotenoids, both isolated in organic media and assembled within LH2 complexes. Measurements of excited-state energy transfer to the array of excitonically coupled bacteriochlorophyll a molecules (B850) show that the mean lifetime of the first singlet excited state (S1) of the long-chain (N≥13) carotenoids does not change appreciably between organic media and the protein environment. In each case, the S1 state appears to lie lower in energy than that of B850. The energy-transfer yield is ~0.4 in LH2 (from the strain grown aerobically or semi-aerobically), which is less than half that achieved for LH2 that contains short-chain (N≤11) analogues. Collectively, the results suggest that the S1 excited state of the long-chain (N≥13) carotenoids participates little if at all in carotenoid-to-BChl a energy transfer, which occurs predominantly via the carotenoid S2 excited state in these antennas. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Monomeric RC-LH1 core complexes retard LH2 assembly and intracytoplasmic membrane formation in PufX-minus mutants of Rhodobacter sphaeroides.

    Science.gov (United States)

    Adams, Peter G; Mothersole, David J; Ng, Irene W; Olsen, John D; Hunter, C Neil

    2011-09-01

    In the model photosynthetic bacterium Rhodobacter sphaeroides domains of light-harvesting 2 (LH2) complexes surround and interconnect dimeric reaction centre-light-harvesting 1-PufX (RC-LH1-PufX) 'core' complexes, forming extensive networks for energy transfer and trapping. These complexes are housed in spherical intracytoplasmic membranes (ICMs), which are assembled in a stepwise process where biosynthesis of core complexes tends to dominate the early stages of membrane invagination. The kinetics of LH2 assembly were measured in PufX mutants that assemble monomeric core complexes, as a consequence of either a twelve-residue N-terminal truncation of PufX (PufXΔ12) or the complete removal of PufX (PufX(-)). Lower rates of LH2 assembly and retarded maturation of membrane invagination were observed for the larger and less curved ICM from the PufX(-) mutant, consistent with the proposition that local membrane curvature, initiated by arrays of bent RC-LH1-PufX dimers, creates a favourable environment for stable assembly of LH2 complexes. Transmission electron microscopy and high-resolution atomic force microscopy were used to examine ICM morphology and membrane protein organisation in these mutants. Some partitioning of core and LH2 complexes was observed in PufX(-) membranes, resulting in locally ordered clusters of monomeric RC-LH1 complexes. The distribution of core and LH2 complexes in the three types of membrane examined is consistent with previous models of membrane curvature and domain formation (Frese et al., 2008), which demonstrated that a combination of crowding and asymmetries in sizes and shapes of membrane protein complexes drives membrane organisation. 2011 Elsevier B.V. All rights reserved.

  1. Manipulating the Energetics and Rates of Electron Transfer in Rhodobacter capsulatus Reaction Centers with Asymmetric Pigment Content

    Energy Technology Data Exchange (ETDEWEB)

    Faries, Kaitlyn M. [Department; Dylla, Nicholas P. [Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Hanson, Deborah K. [Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Holten, Dewey [Department; Laible, Philip D. [Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Kirmaier, Christine [Department

    2017-07-17

    Seemingly redundant parallel pathways for electron transfer (ET), composed of identical sets of cofactors, are a cornerstone feature of photosynthetic reaction centers (RCs) involved in light-energy conversion. In native bacterial RCs, both A and B branches house one bacteriochlorophyll (BChl) and one bacteriopheophytin (BPh), but the A branch is used exclusively. Described herein are the results-obtained for two Rhodobacter capsulatus RCs with an unnaturally high degree of cofactor asymmetry, two BPh on the RC's B side and two BChl on the A side. These pigment changes derive, respectively, from the His(M180)Leu mutation [a BPh ((Phi(B)) replaces the B-side BChl (BB)], and the Leu(M212)His mutation [a BChl (beta(A))) replaces the A-side BPh (H-A)]. Additionally, Tyr(M208)Phe was employed to disfavor ET to the A branch; in one mutant, Val(M131)Glu creates a hydrogen bond to H-B to enhance ET to H-B. In both Phi(B) mutants, the decay kinetics of the excited primary ET donor (P*) resolve three populations with lifetimes of similar to 9 ps (50-60%), similar to 40 ps (10-20%), and similar to 200 ps (20-30%), with P+Phi(-)(B) formed predominantly from the 9 ps fraction. The 50-60% yield of P+Phi(B)- is the highest yet observed for a Phi(B)-containing RC. The results provide insight into factors needed for efficient multistep ET.

  2. Role of Rhodobacter sphaeroides photosynthetic reaction center residue M214 in the composition, absorbance properties, and conformations of H(A) and B(A) cofactors.

    Science.gov (United States)

    Saer, Rafael G; Hardjasa, Amelia; Rosell, Federico I; Mauk, A Grant; Murphy, Michael E P; Beatty, J Thomas

    2013-04-02

    In the native reaction center (RC) of Rhodobacter sphaeroides, the side chain of (M)L214 projects orthogonally toward the plane and into the center of the A branch bacteriopheophytin (BPhe) macrocycle. The possibility that this side chain is responsible for the dechelation of the central Mg(2+) of bacteriochlorophyll (BChl) was investigated by replacement of (M)214 with residues possessing small, nonpolar side chains that can neither coordinate nor block access to the central metal ion. The (M)L214 side chain was also replaced with Cys, Gln, and Asn to evaluate further the requirements for assembly of the RC with BChl in the HA pocket. Photoheterotrophic growth studies showed no difference in growth rates of the (M)214 nonpolar mutants at a low light intensity, but the growth of the amide-containing mutants was impaired. The absorbance spectra of purified RCs indicated that although absorbance changes are associated with the nonpolar mutations, the nonpolar mutant RC pigment compositions are the same as in the wild-type protein. Crystal structures of the (M)L214G, (M)L214A, and (M)L214N mutants were determined (determined to 2.2-2.85 Å resolution), confirming the presence of BPhe in the HA pocket and revealing alternative conformations of the phytyl tail of the accessory BChl in the BA site of these nonpolar mutants. Our results demonstrate that (i) BChl is converted to BPhe in a manner independent of the aliphatic side chain length of nonpolar residues replacing (M)214, (ii) BChl replaces BPhe if residue (M)214 has an amide-bearing side chain, (iii) (M)214 side chains containing sulfur are not sufficient to bind BChl in the HA pocket, and (iv) the (M)214 side chain influences the conformation of the phytyl tail of the BA BChl.

  3. Nomenclatural availability of the names applied to “varieties” of the green toad (Bufo viridis subgroup in the Italian territory, with emphasis on the variety lineata of Ninni (Anura: Bufonidae

    Directory of Open Access Journals (Sweden)

    Nicola Novarini

    2010-07-01

    Full Text Available Recent molecular investigations on Eurasian green toads led to the recognition of distinct lineages and to the establishment of new taxa within the former Bufo viridis; as a consequence, significant range-wide nomenclatural changes have been proposed, although some uncertainties remained on the available names applicable within the Italian territory. In order to contribute to clarify the matter, we evaluated, under the provisions of the International Code of Zoological Nomenclature, the nomenclatural availability of all the names that have been applied to infrasubspecific entities of the Bufo viridis subgroup within the Italian territory. We also provided a historical overview of the usage of all these names, as well as detailed information on the original material upon which the variety lineata of A.P. Ninni was established. Our analysis supports the view that only the names crucigera Eichwald, 1831 and balearica Boettger, 1880 are available, the former being however junior synonym of B. viridis Laurenti, 1768, whereas the names acutirostris and obtusirostris of Lessona, lineata of Ninni, concolor and maculata of Camerano, and nardoi of Paolucci, Fuhn and Bruno are all not available.

  4. Changes in growth, carbon and nitrogen enzyme activity and mRNA accumulation in the halophilic microalga Dunaliella viridis in response to NaCl stress

    Science.gov (United States)

    Wang, Dongmei; Wang, Weiwei; Xu, Nianjun; Sun, Xue

    2016-12-01

    Many species of microalga Dunaliella exhibit a remarkable tolerance to salinity and are therefore ideal for probing the effects of salinity. In this work, we assessed the effects of NaCl stress on the growth, activity and mRNA level of carbon and nitrogen metabolism enzymes of D. viridis. The alga could grow over a salinity range of 0.44 mol L-1 to 3.00 mol L-1 NaCl, but the most rapid growth was observed at 1.00 mol L-1 NaCl, followed by 2.00 mol L-1 NaCl. Paralleling these growth patterns, the highest initial and total Rubisco activities were detected in the presence of 1.00 mol L-1 NaCl, decreasing to 37.33% and 26.39% of those values, respectively, in the presence of 3.00 mol L-1 NaCl, respectively. However, the highest extracellular carbonic anhydrase (CA) activity was measured in the presence of 2.00 mol L-1 NaCl, followed by 1.00 mol L-1 NaCl. Different from the two carbon enzymes, nitrate reductase (NR) activity showed a slight change under different NaCl concentrations. At the transcriptional level, the mRNAs of Rubisco large subunit ( rbcL), and small subunit ( rbcS), attained their highest abundances in the presence of 1.00 and 2.00 mol L-1 NaCl, respectively. The CA mRNA accumulation was induced from 0.44 mol L-1 to 3.00 mol L-1 NaCl, but the NR mRNA showed the decreasing tendency with the increasing salinity. In conclusion, the growth and carbon fixation enzyme of Rubisco displayed similar tendency in response to NaCl stress, CA was proved be salt-inducible within a certain salinity range and NR showed the least effect by NaCl in D. viridis.

  5. [Lipid and fatty acid profile of Perna viridis, green mussel (Mollusca: Bivalvia) in different areas of the Eastern Venezuela and the West Coast of Trinidad].

    Science.gov (United States)

    Koftayan, Tamar; Milano, Jahiro; D'Armas, Haydelba; Salazar, Gabriel

    2011-03-01

    The species Perna viridis is a highly consumed species, which fast growth makes it an interesting aquaculture alternative for Venezuelan and Trinidad coasts. With the aim to contribute with its nutritional value information, this study analyzed lipid and fatty acid contents from samples taken in five locations from Eastern Venezuela and three from Trinidad West Coast. Total lipids were extracted and quantified, from a pooled sample of 100 organisms per location, by standard gravimetric methods, and their identification and quantification was done by TLC/FID (Iatroscan system). Furthermore, the esterified fatty acids of total lipid, phospholipids and triacylglycerols were identified and quantified by gas chromatography. Eastern Venezuela samples from Los Cedros, La Brea and Chaguaramas showed the highest total lipid values of 7.92, 7.74 and 7.53, respectively, and the minimum values were obtained for La Restinga (6.08%). Among lipid composition, Chacopata samples showed the lowest phospholipid concentration (48.86%) and the maximum values for cholesterol (38.87%) and triacylglycerols (12.26%); besides, La Esmeralda and Rio Caribe samples exhibited maximum phospholipids (88.71 and 84.93 respectively) and minimum cholesterol (6.50 and 4.42%) concentrations. Saturated fatty acids represented between 15.04% and 65.55% within total lipid extracts, with maximum and minimum values for La Esmeralda and Chacopata, respectively. Polyunsaturated results resulted between 7.80 and 37.18%, with higher values in La Brea and lower values in La Esmeralda. For phospholipids, saturated fatty acids concentrations varied between 38.81 and 48.68% for Chaguaramas and Chacopata samples, respectively. In the case of polyunsaturated fatty acids, these varied between non detected and 34.51%, with high concentrations in Los Cedros (27.97%) and Chaguaramas (34.51%) samples. For the triacylglycerols, the saturated fatty acids composition oscillated between 14.27 and 53.80% with low

  6. Different ways to die: cell death modes of the unicellular chlorophyte Dunaliella viridis exposed to various environmental stresses are mediated by the caspase-like activity DEVDase.

    Science.gov (United States)

    Jiménez, Carlos; Capasso, Juan M; Edelstein, Charles L; Rivard, Christopher J; Lucia, Scott; Breusegem, Sophia; Berl, Tomás; Segovia, María

    2009-01-01

    Programmed cell death is necessary for homeostasis in multicellular organisms and it is also widely recognized to occur in unicellular organisms. However, the mechanisms through which it occurs in unicells, and the enzymes involved within the final response is still the subject of heated debate. It is shown here that exposure of the unicellular microalga Dunaliella viridis to several environmental stresses, induced different cell death morphotypes, depending on the stimulus received. Senescent cells demonstrated classical and unambiguous apoptotic-like characteristics such as chromatin condensation, DNA fragmentation, intact organelles, and blebbing of the cell membrane. Acute heat shock caused general swelling and altered plasma membrane, but the presence of chromatin clusters and DNA strand breaks suggested a necrotic-like event. UV irradiated cells presented changes typical for necrosis, together with apoptotic characteristics resembling an intermediate cell-death phenotype termed aponecrosis-like. Cells subjected to hyperosmotic shock revealed chromatin spotting without DNA fragmentation, and extensive cytoplasmic swelling and vacuolization, comparable to a paraptotic-like cell death phenotype. Nitrogen-starved cells showed pyknosis, blebbing, and cytoplasmic consumption, indicating a similarity to autophagic/vacuolar-like cell death. The caspase-like activity DEVDase was measured by using the fluorescent substrate Ac-DEVD-AMC and antibodies against the human caspase-3 active enzyme cross-reacted with bands, the intensity of which paralleled the activity. All the environmental stresses tested produced a substantial increase in both DEVDase activity and protein levels. The irreversible caspase-3 inhibitor Z-DEVD-FMK completely inhibited the enzymatic activity whereas serine and aspartyl proteases inhibitors did not. These results show that cell death in D. viridis does not conform to a single pattern and that environmental stimuli may produce different types of

  7. Depuration Study of Heavy Metal Lead (Pb) and Copper (Cu) in Green Mussels Perna viridis through Continues-discontinues and Acid Extraction Methods

    Science.gov (United States)

    Budiawan; Bakri, Ridla; Cahaya Dani, Intan; Handayani, Sri; Ade Kurnia Putri, Rizki; Tamala, Riska

    2018-01-01

    Green mussel or Perna viridis is filter feeder, which is very susceptible to heavy metals. It takes an effort to release heavy metal contents on the green shell, one of method that can be used to release heavy metal from green shell is depuration proccess. In this research, the depuration process was conducted by continues method of depuration, discontinues method by using various kind of water and acid extraction. The optimum time of continues depuration method is 1.5 hours, with circulation speed 250 L/h and result of Pb metal content decreased is equal to 30.048% and 29.748% for Cu. In the discontinues method, the optimum result was reached at 100oC by using PAM water as the media at 3 h immersion period with decrease of Pb metal content 35.001% and Cu metal content 39.015%. In the acid extraction method, the optimum condition was achieved by 11% acetic acid solvent with decreasing of Pb and Cu levels are 88.224% and 76.298%. For the determination of protein content, the decrease of protein content obtained by treatment with 11% acetic acid extract showed decrease of protein content 36.656% with Kjeldahl method.

  8. Habitat degradation correlates with tolerance to climate-change related stressors in the green mussel Perna viridis from West Java, Indonesia.

    Science.gov (United States)

    Wendling, Carolin Charlotte; Huhn, Mareike; Ayu, Nurina; Bachtiar, Ramadian; von Juterzenka, Karen; Lenz, Mark

    2013-06-15

    It is unclear whether habitat degradation correlates with tolerance of marine invertebrates to abiotic stress. We therefore tested whether resistance to climate change-related stressors differs between populations of the green mussel Perna viridis from a heavily impacted and a mostly pristine site in West Java, Indonesia. In laboratory experiments, we compared their oxygen consumption and mortality under lowered salinity (-13 and -18 units, both responses), hypoxia (0.5 mg/l, mortality only) and thermal stress (+7 °C, mortality only). Mussels from the eutrophied and polluted Jakarta Bay showed a significantly smaller deviation from their normal oxygen consumption and higher survival rates when stressed than their conspecifics from the unaffected Lada Bay. This shows that human induced habitat degradation correlates with mussel tolerance to environmental stress. We discuss possible mechanisms - e.g. the selection of tolerant genotypes or habitat-specific differences in the nutritional status of the mussels - that could explain our observation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. The induction of menadione stress tolerance in the marine microalga, Dunaliella viridis, through cold pretreatment and modulation of the ascorbate and glutathione pools.

    Science.gov (United States)

    Madadkar Haghjou, Maryam; Colville, Louise; Smirnoff, Nicholas

    2014-11-01

    The effect of cold pretreatment on menadione tolerance was investigated in the cells of the marine microalga, Dunaliella viridis. In addition, the involvement of ascorbate and glutathione in the response to menadione stress was tested by treating cell suspensions with l-galactono-1,4-lactone, an ascorbate precursor, and buthionine sulfoximine, an inhibitor of glutathione synthesis. Menadione was highly toxic to non cold-pretreated cells, and caused a large decrease in cell number. Cold pretreatment alleviated menadione toxicity and cold pretreated cells accumulated lower levels of reactive oxygen species, and had enhanced antioxidant capacity due to increased levels of β-carotene, reduced ascorbate and total glutathione compared to non cold-pretreated cells. Cold pretreatment also altered the response to l-galactono-1,4-lactone and buthionine sulfoximine treatments. Combined l-galactono-1,4-lactone and menadione treatment was lethal in non-cold pretreated cells, but in cold-pretreated cells it had a positive effect on cell numbers compared to menadione alone. Overall, exposure of Dunaliella cells to cold stress enhanced tolerance to subsequent oxidative stress induced by menadione. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  10. Toxicological effects of benzo(a)pyrene, DDT and their mixture on the green mussel Perna viridis revealed by proteomic and metabolomic approaches.

    Science.gov (United States)

    Song, Qinqin; Chen, Hao; Li, Yuhu; Zhou, Hailong; Han, Qian; Diao, Xiaoping

    2016-02-01

    Benzo(a)pyrene (BaP) and dichlorodiphenyltrichloroethane (DDT) are persistent organic pollutants and environmental estrogens (EEs) with known toxicity towards the green mussel, Perna viridis. In this study, the toxic effects of BaP (10 µg/L) and DDT (10 µg/L) and their mixture were assessed in green mussel gills with proteomic and metabolomic approaches. Metabolic responses indicated that BaP mainly caused disturbance in osmotic regulation by significantly decrease in branched chain amino acids, dimethylamine and dimethylglycine in gills of male green mussels after exposure for 7 days. DDT mainly caused disturbance in osmotic regulation and energy metabolism by differential alteration of betaine, dimethylamine, dimethylglycine, amino acids, and succinate in gills of male green mussels. However, the mixture of BaP and DDT didn't show obvious metabolite changes. Proteomic analysis showed different protein expression profiles between different treatment groups, which demonstrated that BaP, DDT and their mixture may have different modes of action. Proteomic responses revealed that BaP induced cell apoptosis, disturbance in protein digestion and energy metabolism in gills of green mussels, whereas DDT exposure altered proteins that were associated with oxidative stress, cytoskeleton and cell structure, protein digestion and energy metabolism. However, the mixture of BaP and DDT affected proteins related to the oxidative stress, cytoskeleton and cell structure, protein biosynthesis and modification, energy metabolism, growth and apoptosis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Field experiments on individual adaptation of the spider crab Inachus phalangium to its sea anemone host Anemonia viridis in the northern Adriatic Sea

    Directory of Open Access Journals (Sweden)

    S. LANDMANN

    2015-02-01

    Full Text Available We studied the adaptation of the spider crab Inachus phalangium (Fabricius, 1755 to one of its sea anemone host species, Anemonia viridis (Forsskål, 1775 in the coastal region of Rovinj, Croatia. Similar to other brachyuran species, Inachus spp. generally lives within the anemone to obtain protection from possible predators. Using removal and reintroduction experiments, this study investigates the protection mechanism and shows a loss of adaptation after a period of 10 days when the crabs are taken out of their host and kept solitary. Thirty-nine anemones from two different trial sites were marked individually and the inhabiting crabs were isolated to be released back into their individual hosts later. The reactions of the anemones were closely observed and characterized to determine the respective state of crab adaptation. As 35 out of 39 individuals provoked a defense /attack reaction of the anemone, it is concluded that the crabs possessed some sort of non-permanent protection mechanism that was lost during the test run (chi-square test, p < 0.00014. All tested crabs re-inhabited their host anemones within a maximum of 20 minutes after they had been reintroduced and stung by the anemones. Therefore, habituation to the host’s defense / attack mechanism is acquired individually and not genetically inherent to the species. The results are compared to adaptation and protection data on other decapod crustaceans and some anemonefishes.

  12. Computed tomography of the lung of healthy snakes of the species Python regius, Boa constrictor, Python reticulatus, Morelia viridis, Epicrates cenchria, and Morelia spilota.

    Science.gov (United States)

    Pees, Michael; Kiefer, Ingmar; Thielebein, Jens; Oechtering, Gerhard; Krautwald-Junghanns, Maria-Elisabeth

    2009-01-01

    Thirty-nine healthy boid snakes representing six different species (Python regius, Boa constrictor, Python reticulatus, Morelia viridis, Epicrates cenchria, and Morelia spilota) were examined using computed tomography (CT) to characterize the normal appearance of the respiratory tissue. Assessment was done subjectively and densitometry was performed using a defined protocol. The length of the right lung was calculated to be 11.1% of the body length, without a significant difference between species. The length of the left lung in proportion to the right was dependent on the species examined. The most developed left lung was in P. regius (81.2%), whereas in B. constrictor, the left lung was vestigial or absent (24.7%). A median attenuation of -814.6 HU and a variability of 45.9 HU were calculated for all species with no significant difference between species. Within the species, a significantly higher attenuation was found for P. regius in the dorsal and cranial aspect of the lung compared with the ventral and caudal part. In B. constrictor, the reduced left lung was significantly hyperattenuating compared with the right lung. Results of this study emphasize the value of CT and provide basic reference data for assessment of the snake lung in these species. Veterinary Radiology &

  13. Profiling of ornithine lipids in bacterial extracts of Rhodobacter sphaeroides by reversed-phase liquid chromatography with electrospray ionization and multistage mass spectrometry (RPLC-ESI-MS(n)).

    Science.gov (United States)

    Granafei, Sara; Losito, Ilario; Trotta, Massimo; Italiano, Francesca; de Leo, Vincenzo; Agostiano, Angela; Palmisano, Francesco; Cataldi, Tommaso R I

    2016-01-15

    Ornithine lipids (OLs), a sub-group of the large (and of emerging interest) family of lipoamino acids of bacterial origin, contain a 3-hydroxy fatty acyl chain linked via an amide bond to the α-amino group of ornithine and via an ester bond to a second fatty acyl chain. OLs in extracts of Rhodobacter sphaeroides (R. sphaeroides) were investigated by high-performance reversed phase liquid chromatography (RPLC) with electrospray ionization mass spectrometry (ESI-MS) in negative ion mode using a linear ion trap (LIT). The presence of OLs bearing both saturated (i.e, 16:0, 17:0, 18:0, 19:0 and 20:0) and unsaturated chains (i.e., 18:1, 19:1, 19:2 and 20:1) was ascertained and their identification, even for isomeric, low abundance and partially co-eluting species, was achieved by low-energy collision induced dissociation (CID) multistage mass spectrometry (MS(n), n = 2-4). OLs signatures found in two R. sphaeroides strains, i.e., wild type 2.4.1 and mutant R26, were examined and up to 16 and 17 different OL species were successfully identified, respectively. OLs in both bacterial strains were characterized by several combinations of fatty chains on ester-linked and amide-linked 3-OH fatty acids. Multistage MS spectra of monoenoic amide-linked 3-OH acyl chains, allowed the identification of positional isomer of OL containing 18:1 (i.e. 9-octadecenoic) and 20:1 (i.e. 11-eicosenoic) fatty acids. The most abundant OL ([M-H](-) at m/z 717.5) in R. sphaeroides R26 was identified as OL 3-OH 20:1/19:1 (i.e., 3-OH-eicosenoic acid amide-linked to ornithine and esterified to a nonadecenoic chain containing a cyclopropane ring). An unusual OL (m/z 689.5 for the [M-H](-) ion), most likely containing a cyclopropene ester-linked acyl chain (i.e., OL 3-OH 18:0/19:2), was retrieved only in the carotenoidless mutant strain R26. Based on the biosynthetic pathways already known for cyclopropa(e)ne ring-including acyl chains, a plausible explanation was invoked for the enzymatic

  14. Functional assignment of gene AAC16202.1 from Rhodobacter capsulatus SB1003: new insights into the bacterial SDR sorbitol dehydrogenases family.

    Science.gov (United States)

    Sola-Carvajal, Agustín; García-García, María Inmaculada; Sánchez-Carrón, Guiomar; García-Carmona, Francisco; Sánchez-Ferrer, Alvaro

    2012-11-01

    Short-chain dehydrogenases/reductases (SDR) constitute one of the largest enzyme superfamilies with over 60,000 non-redundant sequences in the database, many of which need a correct functional assignment. Among them, the gene AAC16202.1 (NCBI) from Rhodobacter capsulatus SB1003 has been assigned in Uniprot both as a sorbitol dehydrogenase (#D5AUY1) and, as an N-acetyl-d-mannosamine dehydrogenase (#O66112), both enzymes being of biotechnological interest. When the gene was overexpressed in Escherichia coli Rosetta (DE3)pLys, the purified enzyme was not active toward N-acetyl-d-mannosamine, whereas it was active toward d-sorbitol and d-fructose. However, the relative activities toward xylitol and l-iditol (0.45 and 6.9%, respectively) were low compared with that toward d-sorbitol. Thus, the enzyme could be considered sorbitol dehydrogenase (SDH) with very low activity toward xylitol, which could increase its biotechnological interest for determining sorbitol without the unspecific cross-determination of added xylitol in food and pharma compositions. The tetrameric enzyme (120 kDa) showed similar catalytic efficiency (2.2 × 10(3) M(-1) s(-1)) to other sorbitol dehydrogenases for d-sorbitol, with an optimum pH of 9.0 and an optimum temperature of 37 °C. The enzyme was also more thermostable than other reported SDH, ammonium sulfate being the best stabilizer in this respect, increasing the melting temperature (T(m)) up to 52.9 °C. The enzyme can also be considered as a new member of the Zn(2+) independent SDH family since no effect on activity was detected in the presence of divalent cations or chelating agents. Finally, its in silico analysis enabled the specific conserved sequence blocks that are the fingerprints of bacterial sorbitol dehydrogenases and mainly located at C-terminal of the protein, to be determined for the first time. This knowledge will facilitate future data curation of present databases and a better functional assignment of newly described

  15. Bioaugmentation of Lactobacillus delbrueckii ssp. bulgaricus TISTR 895 to enhance bio-hydrogen production of Rhodobacter sphaeroides KKU-PS5.

    Science.gov (United States)

    Laocharoen, Sucheera; Reungsang, Alissara; Plangklang, Pensri

    2015-01-01

    Bioaugmentation or an addition of the desired microorganisms or specialized microbial strains into the anaerobic digesters can enhance the performance of microbial community in the hydrogen production process. Most of the studies focused on a bioaugmentation of native microorganisms capable of producing hydrogen with the dark-fermentative hydrogen producers while information on bioaugmentation of purple non-sulfur photosynthetic bacteria (PNSB) with lactic acid-producing bacteria (LAB) is still limited. In our study, bioaugmentation of Rhodobacter sphaeroides KKU-PS5 with Lactobacillus delbrueckii ssp. bulgaricus TISTR 895 was conducted as a method to produce hydrogen. Unfortunately, even though well-characterized microorganisms were used in the fermentation system, a cultivation of two different organisms in the same bioreactor was still difficult because of the differences in their metabolic types, optimal conditions, and nutritional requirements. Therefore, evaluation of the physical and chemical factors affecting hydrogen production of PNSB augmented with LAB was conducted using a full factorial design followed by response surface methodology (RSM) with central composite design (CCD). A suitable LAB/PNSB ratio and initial cell concentration were found to be 1/12 (w/w) and 0.15 g/L, respectively. The optimal initial pH, light intensity, and Mo concentration obtained from RSM with CCD were 7.92, 8.37 klux and 0.44 mg/L, respectively. Under these optimal conditions, a cumulative hydrogen production of 3396 ± 66 mL H2/L, a hydrogen production rate (HPR) of 9.1 ± 0.2 mL H2/L h, and a hydrogen yield (HY) of 9.65 ± 0.23 mol H2/mol glucose were obtained. KKU-PS5 augmented with TISTR 895 produced hydrogen from glucose at a relatively high HY, 9.65 ± 0.23 mol H2/mol glucose, i.e., 80 % of the theoretical yield. The ratio of the strains TISTR 895/KKU-PS5 and their initial cell concentrations affected the rate of lactic acid production and its

  16. Crecimiento del mejillón verde Perna viridis (Bivalvia: Mytilidae bajo sistema de cultivo de fondo en la ensenada de Turpialito, Golfo de Cariaco, Venezuela Growth and survival of the green mussel P. viridis (Bivalvia: Mytilidae in bottom culture conditions in Turpialito, Golfo de Cariaco, Venezuela

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    Vanessa Acosta

    2012-12-01

    Full Text Available Los moluscos representan uno de los grupos más importantes desde el punto de vista económico en la acuicultura marina, debido a los bajos costos de producción y a su alta rentabilidad. En este estudio se planteó probar la hipótesis de un mayor crecimiento de Perna viridis en cultivo de fondo, por un mejor aprovechamiento de alimento presente en el medio, lo cual permitirá descartarla o no como especie de cultivo para el Golfo de Cariaco. En este sentido, se evaluó el crecimiento y la supervivencia del mejillón verde P. viridis en condiciones de cultivo de fondo entre julio 2007 y febrero 2008. Las semillas del mejillón (35.81±1.41mm de longitud fueron obtenidas en la localidad de Guaca (costa norte del estado Sucre y trasladadas hasta la Estación Hidrobiológica de Turpialito, golfo de Cariaco, estado Sucre-Venezuela, en donde se sembraron en cestas “españolas”. Mensualmente se determinó supervivencia así como la longitud máxima de la concha, la masa seca del músculo, resto de tejidos y de la gónada. Los parámetros ambientales (temperatura del agua, salinidad, oxígeno disuelto, clorofila a, seston total y su fracción orgánica, en la zona de cultivo se determinaron cada 15 días. Mensualmente se realizaron determinaciones de proteínas, lípidos y carbohidratos al seston. Durante todo el estudio el mejillón mantuvo un crecimiento continuo, alcanzando al final una longitud máxima de 78.7±4.43mm. Sin embargo, la tasa de crecimiento de la masa seca de los tejidos somáticos (músculo, resto de tejido y reproductivo, mostraron variabilidad a lo largo del estudio, produciéndose al final un incremento significativo en dichos tejidos. Las variaciones observadas en la tasa de crecimiento de la masa del tejido reproductivo, dependió de las reservas acumuladas y del alimento ofertado por el medio ambiente. El seston orgánico durante toda la experiencia mostró una independencia de la temperatura y de la clorofila a

  17. De novo assembly and comparative transcriptome analysis of the foot from Chinese green mussel (Perna viridis in response to cadmium stimulation.

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    Xinhui Zhang

    Full Text Available The Chinese green mussel, Perna viridis, is a marine bivalve with important economic values as well as biomonitoring roles for aquatic pollution. Byssus, secreted by the foot gland, has been proved to bind heavy metals effectively. In this study, using the RNA sequencing technology, we performed comparative transcriptomic analysis on the mussel feet with or without inducing by cadmium (Cd. Our current work is aiming at providing insights into the molecular mechanisms of byssus binding to heavy metal ions. The transcriptome sequencing generated a total of 26.13-Gb raw data. After a careful assembly of clean data, we obtained a primary set of 105,127 unigenes, in which 32,268 unigenes were annotated. Based on the expression profiles, we identified 9,048 differentially expressed genes (DEGs between Cd treatment (50 or 100 μg/L at 48 h and the control, suggesting an extensive transcriptome response of the mussels during the Cd stimulation. Moreover, we observed that the expression levels of 54 byssus protein coding genes increased significantly after the 48-h Cd stimulation. In addition, 16 critical byssus protein coding genes were picked for profiling by quantitative real-time PCR (qRT-PCR. Finally, we reached a primary conclusion that high content of tyrosine (Tyr, cysteine (Cys, histidine (His residues or the special motif plays an important role in the accumulation of heavy metals in byssus. We also proposed an interesting model for the confirmed byssal Cd accumulation, in which biosynthesis of byssus proteins may play simultaneously critical roles since their transcription levels were significantly elevated.

  18. Density, recruitment and growth performance of Asian green mussel (Perna viridis in Marudu Bay, Northeast Malaysian Borneo, three years after a massive mortality event

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    Afizah Mohd Taib

    2016-12-01

    Full Text Available Density, recruitment and growth performance of Asian green mussel (Perna viridis in a particular coastal marine environment can be affected by many factors, including environmental change, pollution, disease outbreak and massive mortality event. The present study was conducted to determine the density, recruitment and growth performance of farmed Asian green mussel in Marudu Bay, three years after a mass mortality event. The study was carried out for 12 months between April 2013 and March 2014. The length frequency data of 1,308 individuals of green mussel were analyzed using the latest version of the FAO-ICLARM Fish Stock Assessment Tools (FiSAT II. The result showed that the green mussel recruitment in Marudu Bay occurs throughout the year with two major peaks i.e. February and July which coincided with the monsoon seasons. The asymptotic length (L∞, growth coefficient (K and growth performance index (φ’ of the farmed Asian green mussel in Marudu Bay are relatively high at 113.4 mm, 1.7 year-1 and 4.34, respectively. However, despite good culture location, the settlement density of green mussel in the bay was low. We suspected that the low settlement density could be influenced by the ecological effects due to the long term suspension of the culture substrates and the physiochemical properties of the water in Marudu Bay. Nevertheless, chlorophyll-á measurement alone was not able to justify if food scarcity has resulted in high mortality of the farmed Asian green mussel in Marudu Bay.

  19. Engineering of a calcium-ion binding site into the RC-LH1-PufX complex of Rhodobacter sphaeroides to enable ion-dependent spectral red-shifting.

    Science.gov (United States)

    Swainsbury, David J K; Martin, Elizabeth C; Vasilev, Cvetelin; Parkes-Loach, Pamela S; Loach, Paul A; Neil Hunter, C

    2017-11-01

    The reaction centre-light harvesting 1 (RC-LH1) complex of Thermochromatium (Tch.) tepidum has a unique calcium-ion binding site that enhances thermal stability and red-shifts the absorption of LH1 from 880nm to 915nm in the presence of calcium-ions. The LH1 antenna of mesophilic species of phototrophic bacteria such as Rhodobacter (Rba.) sphaeroides does not possess such properties. We have engineered calcium-ion binding into the LH1 antenna of Rba. sphaeroides by progressively modifying the native LH1 polypeptides with sequences from Tch. tepidum. We show that acquisition of the C-terminal domains from LH1 α and β of Tch. tepidum is sufficient to activate calcium-ion binding and the extent of red-shifting increases with the proportion of Tch. tepidum sequence incorporated. However, full exchange of the LH1 polypeptides with those of Tch. tepidum results in misassembled core complexes. Isolated α and β polypeptides from our most successful mutant were reconstituted in vitro with BChl a to form an LH1-type complex, which was stabilised 3-fold by calcium-ions. Additionally, carotenoid specificity was changed from spheroidene found in Rba. sphaeroides to spirilloxanthin found in Tch. tepidum, with the latter enhancing in vitro formation of LH1. These data show that the C-terminal LH1 α/β domains of Tch. tepidum behave autonomously, and are able to transmit calcium-ion induced conformational changes to BChls bound to the rest of a foreign antenna complex. Thus, elements of foreign antenna complexes, such as calcium-ion binding and blue/red switching of absorption, can be ported into Rhodobacter sphaeroides using careful design processes. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  20. Structure and function of cytochrome c2 in electron transfer complexes with the photosynthetic reaction center of Rhodobacter sphaeroides: optical linear dichroism and EPR.

    Science.gov (United States)

    Drepper, F; Mathis, P

    1997-02-11

    The photosynthetic reaction center (RC) and its secondary electron donor the water-soluble cytochrome (cyt) c2 from the purple bacterium Rhodobacter sphaeroides have been used in cross-linked and non-cross-linked complexes, oriented in compressed gels or partially dried multilayers, to study the respective orientation of the primary donor P (BChl dimer) and of cyt c2. Three methods were used: (i) Polarized optical absorption spectra at 295 and 10 K were measured and the linear dichroism of the two individual transitions (Qx, Qy), which are nearly degenerate within the alpha-band of reduced cyt c2, was determined. Attribution of the polarization directions to the molecular axes within the heme plane yielded the average cyt orientation in the complexes. (ii) Time-resolved flash absorption measurements using polarized light allowed determination of the orientation of cyt c2 in complexes which differ in their kinetics of electron transfer. (iii) EPR spectroscopy of ferricyt c2 in cross-linked RC-cyt c2 complexes was used to determine the angle between the heme and the membrane plane. The results suggest the following structural properties for the docking of cyt c2 to the RC: (i) In cross-linked complexes, the two cytochromes displaying half-lives of 0.7 and 60 micros for electron transfer to P+ are similarly oriented (difference plane is parallel to the symmetry axis of the RC (0 degrees +/- 10 degrees). Moreover, the Qy transition, which is assumed to be polarized within the ring III-ring I direction of the heme plane, makes an angle of 56 degrees +/- 1 degree with the symmetry axis. (iii) The dichroism spectrum for the fast phase (0.7 micros) for the non-cross-linked cyt c2-RC complex suggests an orientation similar to that of cross-linked cyt c2, but the heme plane is tilted about 20 degrees closer to the membrane. An alternative model is that two or more bound states of cyt c2 with heme plane tilt angles between 0 degrees and 30 degrees allow the fast electron

  1. The complete chloroplast DNA sequence of the green alga Oltmannsiellopsis viridis reveals a distinctive quadripartite architecture in the chloroplast genome of early diverging ulvophytes

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    Lemieux Claude

    2006-02-01

    Full Text Available Abstract Background The phylum Chlorophyta contains the majority of the green algae and is divided into four classes. The basal position of the Prasinophyceae has been well documented, but the divergence order of the Ulvophyceae, Trebouxiophyceae and Chlorophyceae is currently debated. The four complete chloroplast DNA (cpDNA sequences presently available for representatives of these classes have revealed extensive variability in overall structure, gene content, intron composition and gene order. The chloroplast genome of Pseudendoclonium (Ulvophyceae, in particular, is characterized by an atypical quadripartite architecture that deviates from the ancestral type by a large inverted repeat (IR featuring an inverted rRNA operon and a small single-copy (SSC region containing 14 genes normally found in the large single-copy (LSC region. To gain insights into the nature of the events that led to the reorganization of the chloroplast genome in the Ulvophyceae, we have determined the complete cpDNA sequence of Oltmannsiellopsis viridis, a representative of a distinct, early diverging lineage. Results The 151,933 bp IR-containing genome of Oltmannsiellopsis differs considerably from Pseudendoclonium and other chlorophyte cpDNAs in intron content and gene order, but shares close similarities with its ulvophyte homologue at the levels of quadripartite architecture, gene content and gene density. Oltmannsiellopsis cpDNA encodes 105 genes, contains five group I introns, and features many short dispersed repeats. As in Pseudendoclonium cpDNA, the rRNA genes in the IR are transcribed toward the single copy region featuring the genes typically found in the ancestral LSC region, and the opposite single copy region harbours genes characteristic of both the ancestral SSC and LSC regions. The 52 genes that were transferred from the ancestral LSC to SSC region include 12 of those observed in Pseudendoclonium cpDNA. Surprisingly, the overall gene organization of

  2. Effect of Temperature and Drought Stress on Germination of Slender Amaranth (Amaranthus viridis L. and Prostrate Pigweed (Amaranthus blitoides S. Watson Seeds

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    Marjan Diayanat

    2018-02-01

    Full Text Available Introduction: Slender amaranth (Amaranthus viridis L. and prostrate pigweed (Amaranthus blitoides S. Watson are two common weeds in vegetables and summer crop fields of Iran. The two Amaranthus species have all the attributes required by ecologically successful annual weeds: rapid growth, early reproduction and continuous seed production. Knowledge of the germination requirements of these weeds will helps determine the proper conditions for germination and emergence and allow better management of them. Water and temperature are determining factors for seed germination of weed. Both factors can, separately or jointly, affect the germination percentage and germination rate. Water stress is one of the main constraints on plant growth and the most common environmental stresses around the world. Water stress affects the different aspects of plant growth and causes reduction and delay in seed germination. Seed germination of all plant species requires a minimum of water to be absorbed and swelled and that is why osmotic potential should not be less than a certain amount. Materials and Methods: Seeds were harvested from vegetable fields of Karaj. For breaking dormancy, seeds were treated with concentrated sulfuric acid for two minutes. Two experiments were conducted at Islamic Azad University, Science and Research Branch, Ecology lab, in 2016. First experiment was based on completely randomized design with 4 replications .The seeds were treated with different temperatures (5, 10, 15, 20, 25, 30, 35, 40 and 45oC. Germination percentage and germination rate were measured and seed were considered to have germinated with the emergence of the radical. Intersected lines model is used to determine the cardinal temperature. Second experiment was conducted to determine the effects of simulated dry conditions (use PEG and temperature on seed germination of slender amaranth and prostrate pigweed. Exposure to polyethylene glycol (PEG-6000 solutions has been

  3. Conformational heterogeneity of the bacteriopheophytin electron acceptor HA in reaction centers from Rhodopseudomonas viridis revealed by Fourier transform infrared spectroscopy and site-directed mutagenesis.

    Science.gov (United States)

    Breton, J; Bibikova, M; Oesterhelt, D; Nabedryk, E

    1999-08-31

    The light-induced Fourier transform infrared (FTIR) difference spectra corresponding to the photoreduction of either the HA bacteriopheophytin electron acceptor (HA-/HA spectrum) or the QA primary quinone (QA-/QA spectrum) in photosynthetic reaction centers (RCs) of Rhodopseudomonas viridis are reported. These spectra have been compared for wild-type (WT) RCs and for two site-directed mutants in which the proposed interactions between the carbonyls on ring V of HA and the RC protein have been altered. In the mutant EQ(L104), the putative hydrogen bond between the protein and the 9-keto C=O of HA should be affected by changing Glu L104 to a Gln. In the mutant WF(M250), the van der Waals interactions between Trp M250 and the 10a-ester C=O of HA should be modified. The characteristic effects of both mutations on the FTIR spectra support the proposed interactions and allow the IR modes of the 9-keto and 10a-ester C=O of HA and HA- to be assigned. Comparison of the HA-/HA and QA-/QA spectra leads us to conclude that the QA-/QA IR signals in the spectral range above 1700 cm-1 are largely dominated by contributions from the electrostatic response of the 10a-ester C=O mode of HA upon QA photoreduction. A heterogeneity in the conformation of the 10a-ester C=O mode of HA in WT RCs, leading to three distinct populations of HA, appears to be related to differences in the hydrogen-bonding interactions between the carbonyls of ring V of HA and the RC protein. The possibility that this structural heterogeneity is related to the observed multiexponential kinetics of electron transfer and the implications for primary processes are discussed. The effect of 1H/2H exchange on the QA-/QA spectra of the WT and mutant RCs shows that neither Glu L104 nor any other exchangeable carboxylic residue changes appreciably its protonation state upon QA reduction.

  4. Estabilidad temporal de las infracomunidades de parásitos en la borrachilla Scartichthys viridis (Valenciennes, 1836 (Pisces : Blenniidae en la costa central de Chile Temporal stability in parasite infracommunities of the blenny Scartichthys viridis(Valenciennes, 1836 (Pisces: Blenniidae on the central coast of Chile

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    FREDDY DÍAZ

    2002-12-01

    Full Text Available Se comparan las infracomunidades de parásitos de la borrachilla Scartichthys viridis (Pisces: Blenniidae de tres muestras tomadas en un lapso de 17 meses, entre 1999 y 2001, desde pozas intermareales vecinas a Las Cruces (33°27' S, 71°37' O, Chile central. El objetivo es averiguar si la riqueza, diversidad, abundancia y composición de las infracomunidades de parásitos son persistentes o no en el tiempo ontogenético y cronológico. Se recolectaron 10 taxa parasitarios en cerca del 89 % de los 63 huéspedes examinados, de los cuales ocho eran metazoarios. La búsqueda de protozoos se realizó sólo en los últimos 2 años. El 75 % de los ocho taxa de metazoos ocurrieron en los tres años, uno no estuvo presente en un año, y otro fue encontrado solamente en un año. La mayoría de los huéspedes examinados albergaba protozoos parásitos. La prevalencia de los protozoos Cryptobia sp. fue alta para ambos años, y menor en Trichodina sp. La longitud total de los huéspedes era un predictor relevante de las variaciones en la riqueza, abundancia, diversidad y composición infracomunitaria en el conjunto de los tres años. En cambio, el año de muestreo no lo fue, en particular al comparar entre huéspedes de similar longitud total. Estos resultados son similares a los encontrados en infracomunidades de parásitos de otras especies de peces en Chile, en que hay baja variabilidad en las propiedades agregadas de las infracomunidades en el tiempo cronológico. Se discute acerca de la extensión relativa del tiempo ontogenético en contraste al tiempo cronológico al ser probablemente ambos de importancia en las características de las infracomunidades, y se propone que se explore la medida en la cual estos resultados constituyen un patrón.Parasite infracommunities of the blenny Scartichthys viridis (Pisces: Blenniidae are compared among three samples taken within a 17-month period during three consecutive years (1999-2001, from intertidal pools at

  5. Diferenças morfológicas entre Amaranthus cruentus, cv. BRS Alegria, e as plantas daninhas A. hybridus, A. retroflexus, A. viridis e A. spinosus Morphological differences between Amaranthus cruentus, cv. BRS Alegria, and the weed species A. hybridus, A. retroflexus, A. viridis and A. spinosus

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    C.R. Spehar

    2003-12-01

    Full Text Available O pseudocereal amaranto, com as espécies Amaranthus caudatus, A. cruentus e A. hypochondriacus, domesticado pelas populações indígenas antes que a América fosse descoberta, tem se adaptado aos sistemas produtivos dos cerrados. A planta apresenta panículas apicais, divididas em pequenos ramos com frutos do tipo pixídio, com uma semente cada. Estas germinam rapidamente em presença de umidade, após atingirem a maturação fisiológica. No início da fase vegetativa, o amaranto cultivado pode confundir-se com espécies de plantas daninhas do mesmo gênero (A. hybridus, A. retroflexus, A. viridis e A. spinosus, as quais estão associadas à expansão agrícola. As diferenças morfológicas tornam-se mais visíveis após o florescimento: ramificações com flores axilares e terminais, em contraste com o amaranto, no qual a inflorescência (panícula é apical; as sementes claras das espécies cultivadas contrastam com as das invasoras, que são escuras. BRS Alegria (A. cruentus, cultivar pioneiro no Brasil, apresenta plantas com 180 cm, das quais a panícula ocupa 48 cm; maturação fisiológica aos 90 dias; resistência ao acamamento; e 0,68 g por 1.000 sementes, com produção de 2,3 t ha¹ (sementes e 5,6 t ha-1 (biomassa total. As sementes nas plantas daninhas são menores, germinam gradativamente e podem permanecer no solo por muitos anos, infestando as áreas. As diferenças morfológicas detectadas na experimentação demonstram que as espécies são distinguíveis; elas contribuem para orientar a produção de sementes e o cultivo comercial de amaranto, enfatizando as características de adaptação, em contraste com as das invasoras do mesmo gênero botânico.The pseudocereal grain amaranth, with the species Amaranthus caudatus, A. ruentus e A. hypochondriacus, domesticated by indigenous populations before America was discovered, has shown adaptability to production systems in the Brazilian savannah. The plants present apical

  6. Radiation Dose and Risk Assessments from Polonium-210 in Green Mussels (Perna viridis) and Seafood Consumers Living nearby the Industrial Area in Chonburi Province, Thailand

    Energy Technology Data Exchange (ETDEWEB)

    Tumnoi, Y.; Phaopeng, N. [Office of Atoms for Peace - OAP (Thailand)

    2014-07-01

    Marine environmental samples including seawater (filtered and unfiltered), suspended particles, and green mussels (Perna viridis) were collected from Sriracha and Angsira areas located in Chonburi province in order to determine Po-210 radioactivity. The former was chosen because it is generally believed that this area has been contaminated by one of the largest industrial estates in Thailand and others human-activities (non-nuclear activities) nearby such as oil refineries and Coal Power Plants. Discharges, ashes, and wastes released from these activities may result in an increase of Po-210 concentration in marine environment when compared to other areas. The later was designated to serve as a control site in this study since this area is unlikely to be impacted by industrial activities. Our results revealed that, in the filtered seawater, averaged values of Po-210 level were 0.26 + 0.14 mBq/L (Sriracha) and 0.56 + 0.42 mBq/L (Angsira) and, in the unfiltered seawater, means of Po-210 radioactivity were 2.37 + 0.32 mBq/L (Sriracha) and 4.20 + 2.78 mBq/L (Angsira). Furthermore, the suspended particles contained Po-210 concentrations with averaged values of 14.11 + 8.87 Bq/kg dw (Sriracha) and 102.21 + 51.49 Bq/kg dw (Angsira) while averaged Po-210 levels of 35.74 + 17.53 Bq/kg dw (Sriracha) and 71.12 + 62.88 Bq/kg dw (Angsira) were found in the green mussels examined. The present finding indicates that there is no radiological impact caused by those human activities to the marine environment at Sriracha. Radiation dose assessment was also performed in both the green mussels and human who consume green mussels. The results show that the green mussels farmed at Sriracha and Angsira received averaged radiation dose rates from Po-210 at 0.0007 and 0.0015 mGy/d, respectively. In addition, our results reveal that populations living in Chonburi province and ingesting the green mussels from these 2 locations received radiation dose rates from Po-210 at the means of 44.25 and

  7. Sphodromantis viridis (Forskal, 1775: New for Portugal and new records of the rare and small mantids Apteromantis aptera (Fuente, 1894 and Perlamantis allibertii Guérin-Méneville, 1843 in the country (Mantodea: Mantidae and Amorphoscelidae

    Directory of Open Access Journals (Sweden)

    Eduardo Marabuto

    2014-01-01

    Full Text Available Several new records are presented on some of the least known mantis species in the Iberian Peninsula. From data collected in Portugal, their analysis has proven to represent an important advancement in the knowledge of this group of insects for the country and the Western Mediterranean area. Twenty new citations provide a better understanding on the distribution of the crepuscular species Perlamantis allibertii, the IUCN red listed Apteromantis aptera and the first Portuguese records of Sphodromantis viridis, extending their western limits of occurrence in Europe. The data thus gathered emphasizes the need to invest in biodiversity assessment for increased knowledge on species distribution and phenology but also for monitoring over time, essential to better ascertaining ecosystem services, the effects of climate change and habitat conservation.

  8. Elimination of polarity in the carotenoid terminus promotes the exposure of B850-binding sites (Tyr 44, 45) and ANS-mediated energy transfer in LH2 complexes of Rhodobacter sphaeroides.

    Science.gov (United States)

    Liu, Yuan; Wu, Yongqiang; Xu, Chunhe

    2004-12-10

    Carotenoids in the peripheral light-harvesting complexes (LH2) of the green mutant (GM309) of Rhodobacter sphaeroides were identified as containing neurosporenes, which lack the polar CH(3)O group, compared to spheroidenes in native-LH2 of R. sphaeroides 601. After LH2 complexes were treated with 1-anilino-8-naphthalene sulfonate (ANS), new energy transfer pathways from ANS or tryptophan to carotenoids were discovered in both native- and GM309-LH2. The carotenoid fluorescence intensity of GM309-LH2 was greater than that of native-LH2 when bound with ANS, suggesting that the elimination of polarity in the neurosporene increases the energy transfer from ANS to carotenoid. The fact that two alpha-tyrosines (alpha-Tyr 44, 45, B850-binding sites) in each alpha-apoprotein of GM309-LH2 were more easily modified than those of native-LH2 by N-acetylimidazole (NAI) indicates that the elimination of polarity in the neurosporene terminus increases the exposure of these sites to solution.

  9. Effect of co-substrate on production of poly-β- hydroxybutyrate (PHB and copolymer PHBV from newly identified mutant Rhodobacter sphaeroides U7 cultivated under aerobic-dark condition

    Directory of Open Access Journals (Sweden)

    Kemarajt Kemavongse

    2007-07-01

    Full Text Available Photosynthetic bacterial mutant strain U7 was identified using both classical and molecular (16S rDNA techniques to be Rhodobacter sphaeroides. The glutamate-acetate (GA medium containing sodium acetate and sodium glutamate as carbon and nitrogen sources was used for production of poly-β-hydroxybutyrate (PHB from R. sphaeroides U7 cultivated under aerobic-dark condition (200 rpm at 37oC. Effect of auxiliary carbon sources (propionate and valerate and concentrations (molar ratio of 40/0, 40/20, 40/40 and 40/80 on copolymer production were studied. Both combinations of acetate with valerate and acetate with propionate were found to induce the accumulation of poly-β-hydroxybutyrate-co-β-hydroxyvalerate (PHBV within the cell. Acetate with propionate in the molar ratio of 40/40 gave the highest poly-β-hydroxyalkanoates (PHA content (77.68%, followed by acetate with valerate at the same molar ratio (77.42%. Although their polymer contents were similar, the presence of 40 mM valerate gave more than 4 times higher hydroxyvalerate (HV fraction (84.77% than in the presence of 40 mM propionate (19.12% HV fraction.

  10. Comunidad de moluscos asociados al mejillón verde Perna viridis (Mollusca: Bivalvia y sus relaciones tróficas en la costa norte de la Península de Araya, Estado Sucre, Venezuela

    Directory of Open Access Journals (Sweden)

    Sioliz Villafranca

    2006-12-01

    Full Text Available Perna viridis es un bivalvo procedente del Indo-Pacífico que habita en la zona intermareal y ha invadido varios ecosistemas de la costa norte del estado Sucre, Venezuela. Con la finalidad de realizar un estudio sobre las comunidades de moluscos asociadas a esta especie y sus relaciones tróficas, se llevaron a cabo muestreos bimensuales entre octubre/97 y agosto/98, en un banco natural de mejillones a dos metros de profundidad en la costa norte de la península de Araya (10°40’N -48°63’W. Los organismos fueron recolectados delimitando el área con una cuadrícula de 0.25 m². Se identificaron los organismos hasta la categoría de especies utilizando claves específicas para moluscos y bibliográficamente se les determinó categoría trófica.Se capturó un total de 1 235 individuos de P. viridis y asociados a la especie 3 163 especímenes pertenecientes al phylum Mollusca, contenidos en tres clases: Bivalvia,Gastropoda y Polyplacophora. Éstas estuvieron representadas por 50 especies correspondientes a 10 órdenes, 24 familias; para los gasterópodos se contabilizaron 25 especies, para los bivalvos 22 y tres para los poliplacóforos. Del total de las especies, 40% fueron filtradoras, 26% carnívoras, 24% herbívoras y el 10% restante presentó dos categorías.De las filtradoras las más representativas fueron: Perna perna, Musculus lateralis, Crassostrea rhizophorae y Ostrea equestris; en el grupo de los carnívoros dominaron tres especies de la familia Columbellidae:Mitrella lunata, Anachis obesa y Nitidella ocellata y para el grupo de los herbívoros destacaron dos especies de la familia Fisurellidae: Diodora cayenensis y D. minuta. Se registraron dos especies filtradoras-detritívoras, y tres especies herbívoras-filtradoras representantes del género C repidula. El alto porcentaje de filtradores sería un indicativo de que dentro de este sistema probablemente hay una mayor disponibilidad de fracciones alimenticias para este grupo

  11. Role of PufX protein in photosynthetic growth of Rhodobacter sphaeroides. 1. PufX is required for efficient light-driven electron transfer and photophosphorylation under anaerobic conditions.

    Science.gov (United States)

    Barz, W P; Francia, F; Venturoli, G; Melandri, B A; Verméglio, A; Oesterhelt, D

    1995-11-21

    The pufX gene is essential for photoheterotrophic growth of the purple bacterium Rhodobacter sphaeroides. In order to analyze the molecular function of the PufX membrane protein, we constructed a chromosomal pufX deletion mutant and phenotypically compared it to a pufX+ control strain and to two suppressor mutants which are able to grow photosynthetically in the absence of pufX. Using this genetic background, we confirmed that PufX is required for photoheterotrophic growth under anaerobic conditions, although all components of the photosynthetic apparatus were present in similar amounts in all strains investigated. We show that the deletion of PufX is not lethal for illuminated pufX- cells, suggesting that PufX is required for photosynthetic cell division. Since chromatophores isolated from the pufX- mutant were found to be unsealed vesicles, the role of PufX in photosynthetic energy transduction was studied in vivo. We show that PufX is essential for light-induced ATP synthesis (photophosphorylation) in anaerobically incubated cells. Measurements of absorption changes induced by a single turnover flash demonstrated that PufX is not required for electron flow through the reaction center and the cytochrome bc1 complex under anaerobic conditions. During prolonged illumination, however, PufX is essential for the generation of a sufficiently large membrane potential to allow photosynthetic growth. These in vivo results demonstrate that under anaerobic conditions PufX plays an essential role in facilitating effective interaction of the components of the photosynthetic apparatus.

  12. Role of charge-transfer states in bacterial photosynthesis

    NARCIS (Netherlands)

    Meech, S.R.; Hoff, A.J.

    1986-01-01

    Photon echo, photon-echo excitation, and "hole-burning" data recorded in the 800-990 nm region of Rhodobacter sphaeroides R26 and Rhodopseudomonas viridis reaction centers are reported. The primary process in these reaction centers, following excitation, was found to occur in ≈25 fsec; the

  13. Perfil de lípidos y ácidos grasos de Perna viridis, mejillón verde (Mollusca: Bivalvia en el oriente venezolano y la costa oeste de Trinidad

    Directory of Open Access Journals (Sweden)

    Tamar Koftayan

    2011-03-01

    Full Text Available Los lípidos totales fueron extraídos, identificados y cuantificados por gravimetría, mediante TLC/FID (sistema Iatroscan. Los ácidos grasos de los lípidos totales, fosfolípidos y triacilgliceroles fueron identificados y cuantificados por cromatografía de gases. Las mayores concentraciones de lípidos totales se presentaron en las muestras de Los Cedros, La Brea y Chaguaramas con valores de 7.92, 7.74 y 7.53%; respectivamente y los valores mínimos en las de La Restinga (6.08%. En la composición lípidica, las muestras de Chacopata presentaron la menor concentración de fosfolípidos (48.86% y los máximos valores de colesterol (38.87% y triacilgliceroles (12.26%, y las muestras de La Esmeralda y Río Caribe exhibieron concentraciones máximas de fosfolípidos (88.71-84.93%, respectivamente y mínimas de colesterol (6.50-4.42%. En los lípidos totales, los ácidos grasos saturados se encontraron entre 15.04 y 65.55%, con máximos en muestras de La Esmeralda y mínimos en Chacopata y los poliinsaturados estuvieron entre 7.80 y 37.18%, con máximos valores en la Brea y mínimos en la Esmeralda. En los fosfolípidos, la concentración de ácidos grasos saturados estuvo entre 38.81 y 48.68% para las muestras de Chaguaramas y Chacopata, respectivamente; los ácidos grasos poliinsaturados se encontraron entre no detectado y 34.51%, con altas concentraciones en muestras de Los Cedros (27.97% y Chaguaramas (34.51%. En los triacilgliceroles, la composición de ácidos grasos saturados variaron entre 14.27 y 53.80%, con baja concentración en Chacopata y alta concentración en La Restinga; los ácidos grasos poliinsaturados estuvieron entre 4.66 y 35.55%, con valores menores en las muestras de Chacopata (4.66% y mayores en Chaguaramas. El consumo frecuente de Perna viridis es recomendable, debido a su alto contenido de fosfolípidos y ácidos grasos insaturados.Lipid and fatty acid profile of Perna viridis, Green Mussel (Mollusca: Bivalvia in

  14. Respiratory Syncytial Virus Fusion Protein-Induced Toll-Like Receptor 4 (TLR4) Signaling Is Inhibited by the TLR4 Antagonists Rhodobacter sphaeroides Lipopolysaccharide and Eritoran (E5564) and Requires Direct Interaction with MD-2

    Science.gov (United States)

    Rallabhandi, Prasad; Phillips, Rachel L.; Boukhvalova, Marina S.; Pletneva, Lioubov M.; Shirey, Kari Ann; Gioannini, Theresa L.; Weiss, Jerrold P.; Chow, Jesse C.; Hawkins, Lynn D.; Vogel, Stefanie N.; Blanco, Jorge C. G.

    2012-01-01

    ABSTRACT Respiratory syncytial virus (RSV) is a leading cause of infant mortality worldwide. Toll-like receptor 4 (TLR4), a signaling receptor for structurally diverse microbe-associated molecular patterns, is activated by the RSV fusion (F) protein and by bacterial lipopolysaccharide (LPS) in a CD14-dependent manner. TLR4 signaling by LPS also requires the presence of an additional protein, MD-2. Thus, it is possible that F protein-mediated TLR4 activation relies on MD-2 as well, although this hypothesis has not been formally tested. LPS-free RSV F protein was found to activate NF-κB in HEK293T transfectants that express wild-type (WT) TLR4 and CD14, but only when MD-2 was coexpressed. These findings were confirmed by measuring F-protein-induced interleukin 1β (IL-1β) mRNA in WT versus MD-2−/− macrophages, where MD-2−/− macrophages failed to show IL-1β expression upon F-protein treatment, in contrast to the WT. Both Rhodobacter sphaeroides LPS and synthetic E5564 (eritoran), LPS antagonists that inhibit TLR4 signaling by binding a hydrophobic pocket in MD-2, significantly reduced RSV F-protein-mediated TLR4 activity in HEK293T-TLR4–CD14–MD-2 transfectants in a dose-dependent manner, while TLR4-independent NF-κB activation by tumor necrosis factor alpha (TNF-α) was unaffected. In vitro coimmunoprecipitation studies confirmed a physical interaction between native RSV F protein and MD-2. Further, we demonstrated that the N-terminal domain of the F1 segment of RSV F protein interacts with MD-2. These data provide new insights into the importance of MD-2 in RSV F-protein-mediated TLR4 activation. Thus, targeting the interaction between MD-2 and RSV F protein may potentially lead to novel therapeutic approaches to help control RSV-induced inflammation and pathology. PMID:22872782

  15. The crystal structures of the tri-functional Chloroflexus aurantiacus and bi-functional Rhodobacter sphaeroides malyl-CoA lyases and comparison with CitE-like superfamily enzymes and malate synthases.

    Science.gov (United States)

    Zarzycki, Jan; Kerfeld, Cheryl A

    2013-11-09

    Malyl-CoA lyase (MCL) is a promiscuous carbon-carbon bond lyase that catalyzes the reversible cleavage of structurally related Coenzyme A (CoA) thioesters. This enzyme plays a crucial, multifunctional role in the 3-hydroxypropionate bi-cycle for autotrophic CO2 fixation in Chloroflexus aurantiacus. A second, phylogenetically distinct MCL from Rhodobacter sphaeroides is involved in the ethylmalonyl-CoA pathway for acetate assimilation. Both MCLs belong to the large superfamily of CitE-like enzymes, which includes the name-giving β-subunit of citrate lyase (CitE), malyl-CoA thioesterases and other enzymes of unknown physiological function. The CitE-like enzyme superfamily also bears sequence and structural resemblance to the malate synthases. All of these different enzymes share highly conserved catalytic residues, although they catalyze distinctly different reactions: C-C bond formation and cleavage, thioester hydrolysis, or both (the malate synthases). Here we report the first crystal structures of MCLs from two different phylogenetic subgroups in apo- and substrate-bound forms. Both the C. aurantiacus and the R. sphaeroides MCL contain elaborations on the canonical β8/α8 TIM barrel fold and form hexameric assemblies. Upon ligand binding, changes in the C-terminal domains of the MCLs result in closing of the active site, with the C-terminal domain of one monomer forming a lid over and contributing side chains to the active site of the adjacent monomer. The distinctive features of the two MCL subgroups were compared to known structures of other CitE-like superfamily enzymes and to malate synthases, providing insight into the structural subtleties that underlie the functional versatility of these enzymes. Although the C. aurantiacus and the R. sphaeroides MCLs have divergent primary structures (~37% identical), their tertiary and quaternary structures are very similar. It can be assumed that the C-C bond formation catalyzed by the MCLs occurs as proposed for

  16. Role of the PufX protein in photosynthetic growth of Rhodobacter sphaeroides. 2. PufX is required for efficient ubiquinone/ubiquinol exchange between the reaction center QB site and the cytochrome bc1 complex.

    Science.gov (United States)

    Barz, W P; Verméglio, A; Francia, F; Venturoli, G; Melandri, B A; Oesterhelt, D

    1995-11-21

    The PufX membrane protein is essential for photosynthetic growth of Rhodobacter sphaeroides because it is required for multiple-turnover electron transfer under anaerobic conditions [see accompanying article; Barz, W. P., Francia, F., Venturoli, G., Melandri, B. A., Verméglio, A., & Oesterhelt, D. (1995) Biochemistry 34, 15235-15247]. In order to understand the molecular role of PufX, light-induced absorption spectroscopy was performed using a pufX- mutant, a pufX+ strain, and two suppressor mutants. We show that the reaction center (RC) requires PufX for its functionality under different redox conditions than the cytochrome bc1 complex: When the kinetics of flash-induced reduction of cytochrome b561 were monitored in chromatophores, we observed a requirement of PufX for turnover of the cytochrome bc1 complex only at high redox potential (Eh > 140 mV), suggesting a function of PufX in lateral ubiquinol transfer from the RC. In contrast, PufX is required for multiple turnover of the RC only under reducing conditions: When the Q pool was partially oxidized in vivo using oxygen or electron acceptors like dimethyl sulfoxide or trimethylamine N-oxide, the deletion of PufX had no effect on light-driven electron flow through the RC. Flash train experiments under anaerobic in vivo conditions revealed that RC photochemistry does not depend on PufX for the first two flash excitations. Following the third and subsequent flashes, however, efficient charge separation requires PufX, indicating an important role of PufX for fast Q/QH2 exchange at the QB site of the RC. We show that the Q/QH2 exchange rate is reduced approximately 500-fold by the deletion of PufX when the Q pool is nearly completely reduced, demonstrating an essential role of PufX for the access of ubiquinone to the QB site. The fast ubiquinone/ubiquinol exchange is partially restored by suppressor mutations altering the macromolecular antenna structure. These results suggest an indirect role of PufX in

  17. The unusually strong hydrogen bond between the carbonyl of Q(A) and His M219 in the Rhodobacter sphaeroides reaction center is not essential for efficient electron transfer from Q(A)(-) to Q(B).

    Science.gov (United States)

    Breton, Jacques; Lavergne, Jérôme; Wakeham, Marion C; Nabedryk, Eliane; Jones, Michael R

    2007-06-05

    In native reaction centers (RCs) from photosynthetic purple bacteria the primary quinone (QA) and the secondary quinone (QB) are interconnected via a specific His-Fe-His bridge. In Rhodobacter sphaeroides RCs the C4=O carbonyl of QA forms a very strong hydrogen bond with the protonated Npi of His M219, and the Ntau of this residue is in turn coordinated to the non-heme iron atom. The second carbonyl of QA is engaged in a much weaker hydrogen bond with the backbone N-H of Ala M260. In previous work, a Trp side chain was introduced by site-directed mutagenesis at the M260 position in the RC of Rb. sphaeroides, resulting in a complex that is completely devoid of QA and therefore nonfunctional. A photochemically competent derivative of the AM260W mutant was isolated that contains a Cys side chain at the M260 position (denoted AM260(W-->C)). In the present work, the interactions between the carbonyl groups of QA and the protein in the AM260(W-->C) suppressor mutant have been characterized by light-induced FTIR difference spectroscopy of the photoreduction of QA. The QA-/QA difference spectrum demonstrates that the strong interaction between the C4=O carbonyl of QA and His M219 is lost in the mutant, and the coupled CO and CC modes of the QA- semiquinone are also strongly perturbed. In parallel, a band assigned to the perturbation of the C5-Ntau mode of His M219 upon QA- formation in the native RC is lacking in the spectrum of the mutant. Furthermore, a positive band between 2900 and 2400 cm-1 that is related to protons fluctuating within a network of highly polarizable hydrogen bonds in the native RC is reduced in amplitude in the mutant. On the other hand, the QB-/QB FTIR difference spectrum is essentially the same as for the native RC. The kinetics of electron transfer from QA- to QB were measured by the flash-induced absorption changes at 780 nm. Compared to native RCs the absorption transients are slowed by a factor of about 2 for both the slow phase (in the

  18. Plasmon waveguide resonance spectroscopic evidence for differential binding of oxidized and reduced rhodobacter capsulatus cytochrome c(2) to the cytochrome bc(1) complex mediated by the conformation of the rieske iron-sulfur protein

    International Nuclear Information System (INIS)

    Devanathan, S.; Salamon, Z.; Tollin, G.; Fitch, J.C.; Meyer, T.E.; Berry, E.A.; Cusanovich, M.A.

    2007-01-01

    The dissociation constants for the binding of Rhodobacter capsulatus cytochrome c2 and its K93P mutant to the cytochrome bc1 complex embedded in a phospholipid bilayer were measured by plasmon waveguide resonance spectroscopy in the presence and absence of the inhibitor stigmatellin. The reduced form of cytochrome c2 strongly binds to reduced cytochrome bc1 (Kd = 0.02 M) but binds much more weakly to the oxidized form (Kd = 3.1 M). In contrast, oxidized cytochrome c2 binds to oxidized cytochrome bc1 in a biphasic fashion with Kd values of 0.11 and 0.58 M. Such a biphasic interaction is consistent with binding to two separate sites or conformations of oxidized cytochrome c2 and/or cytochrome bc1. However, in the presence of stigmatellin, we find that oxidized cytochrome c2 binds to oxidized cytochrome bc1 in a monophasic fashion with high affinity (Kd = 0.06 M) and reduced cytochrome c2 binds less strongly (Kd = 0.11 M) but ∼30-fold more tightly than in the absence of stigmatellin. Structural studies with cytochrome bc1, with and without the inhibitor stigmatellin, have led to the proposal that the Rieske protein is mobile, moving between the cytochrome b and cytochrome c1 components during turnover. In one conformation, the Rieske protein binds near the heme of cytochrome c1, while the cytochrome c2 binding site is also near the cytochrome c1 heme but on the opposite side from the Rieske site, where cytochrome c2 cannot directly interact with Rieske. However, the inhibitor, stigmatellin, freezes the Rieske protein iron-sulfur cluster in a conformation proximal to cytochrome b and distal to cytochrome c1. We conclude from this that the dual conformation of the Rieske protein is primarily responsible for biphasic binding of oxidized cytochrome c2 to cytochrome c1. This optimizes turnover by maximizing binding of the substrate, oxidized cytochrome c2, when the iron-sulfur cluster is proximal to cytochrome b and minimizing binding of the product, reduced cytochrome c

  19. Distribución de los inmaduros de Antichloris viridis Druce, 1884 en la planta de plátano (Musa AAB, sub grupo plátano, cv. Hartón) en el sur del lago de Maracaibo, Venezuela.

    OpenAIRE

    Liscano, O.A.; Domínguez Gil, O

    2005-01-01

    Para determinar la distribución de Antichloris viridis, en la planta de plátano, se seleccionaron dos plantaciones comerciales, en los municipios Francisco Javier Pulgar y Colón del estado Zulia, Venezuela. Se clasificaron los estados de desarrollo de las plantas (GD) en seis grados de acuerdo al número de hojas y el estado fisiológico de la planta. Se determinó el % de defoliación y la presencia de huevos, larvas pequeñas, medianas y grandes y pupas por hoja. Se delimitaron tres estratos por...

  20. On Psophia viridis and Ps. obscura

    NARCIS (Netherlands)

    Finsch, O.

    1898-01-01

    When Dr. Sharpe wrote the Catalogue of the Fulicariae and Alectorides (Birds, vol. XXIII, 1894) he referred with regard to the above two species to the material in the Leyden Museum, as they were not then represented in the collection of the British Museum. Misled by the wrong determination of the

  1. Влияние гипоксии на синтез низкомолекулярных антиоксидантов Fragaria viridis Duch

    OpenAIRE

    Гусев, Николай; Петрова, Галина; Немерешина, Ольга; Бомбела, Татьяна

    2012-01-01

    В статье приведены данные по содержанию низкомолекулярных антиоксидантов (танидов) в тканях Fragaria viridis Duch., произрастающей в различных экологических условиях. Выявлены отличия в содержании антиоксидантов для растений, подвергшихся воздействию гипоксии.

  2. Содержаниe витаминов в листьях Fragaria viridis Duch. (Weston) степной зоны оренбургского Предуралья

    OpenAIRE

    Докучаева, Юлия; Гусев, Николай; Немерешина, Ольга

    2015-01-01

    Изучена зависимость содержания витаминов от экологических условий в растении Fragaria viridis Duch. (Weston) землянике зелёной, или клубнике. Результаты исследований показывают, что содержание антиоксидантов аскробиновой кислоты, токоферола и каротина в листьях Fragaria viridis обусловлено фазой развития растений и их местообитанием. Показано повышенное содержание токоферола в листьях растения, произрастающего в зоне влияния промышленных поллютантов, что, возможно, является одним из механизмо...

  3. Kinetics of Soluble Glucan Production by Claviceps viridis

    Czech Academy of Sciences Publication Activity Database

    Flieger, Miroslav; Kantorová, M.; Benešová, T.; Pažoutová, Sylvie; Votruba, Jaroslav

    2003-01-01

    Roč. 48, č. 5 (2003), s. 633-638 ISSN 0015-5632 R&D Projects: GA ČR GA525/00/1283 Institutional research plan: CEZ:AV0Z5020903 Keywords : eps * hplc Subject RIV: EE - Microbiology, Virology Impact factor: 0.857, year: 2003

  4. Efeito de cascas de café e de arroz dispostas nas camadas do solo sobre a germinação e o crescimento inicial do caruru-de-mancha Allelopathic effect of coffee and rice husks arranged in soil layers on the germination and initial growth of Amaranthus viridis

    Directory of Open Access Journals (Sweden)

    J.C.F. Santos

    2001-08-01

    Full Text Available Estudos dos efeitos dos resíduos de plantas pela utilização de coberturas mortas no controle das plantas daninhas têm apresentado dificuldade de determinar a diferenciação entre alelopatia e competição. Atualmente, muitas pesquisas têm se referido a critérios que propõem evidência à alelopatia. Este trabalho em casa de vegetação visou determinar os efeitos alelopáticos proporcionados pelas cascas de café e de arroz sobre o caruru-de-mancha, por meio das disposições desses resíduos nas camadas do solo. O delineamento experimental foi o de blocos casualizados, com os tratamentos em quatro repetições e organizados num esquema fatorial (3x3, sendo cascas de café e de arroz e vermiculita expandida como um fator e suas disposições, com resíduos depositados no topo, incorporados na superfície e incorporados no fundo, como segundo fator. Como testemunha foi usado um tratamento adicional sem cobertura. De modo geral, resíduos de cascas proporcionaram inibição da germinação e estímulo ao crescimento do caruru-de-mancha. A casca de arroz proporcionou menor índice de velocidade de emergência e germinação de sementes do que a casca de café. A casca de café depositada no topo proporcionou maior crescimento e maior peso da matéria seca do caruru-de-mancha, seguido pela mesma casca incorporada na superfície do solo.Studies of plant residue effects involving mulches to control weeds in perennial crops are difficult to carry out due to the need to differentiate between allelopathy and competition. Many researches, nowadays, refer to criteria proving allelopathy. This work was established under greenhouse conditions to determine the allelopathic effects of coffee and rice husks on Amaranthus viridis through their arrangements in soil layers. The experimental design was a randomized block with four replications, arranged in a 3 x 3 factorial scheme, with coffee and rice husks and expanded vermiculite being one factor and

  5. Биохимические особенности и антибактериальное действие препаратов Fragaria viridis

    OpenAIRE

    ГУСЕВ НИКОЛАЙ ФЁДОРОВИЧ; ДОКУЧАЕВА ЮЛИЯ АЛЕКСЕЕВНА; СЫЧЁВА МАРИЯ ВИКТОРОВНА; НЕМЕРЕШИНА ОЛЬГА НИКОЛАЕВНА

    2016-01-01

    Представлены результаты исследования полифенольного комплекса (флавоноиды, таниды и фенолкарбоновые кислоты) в листьях Fragaria viridis Duch. (Weston.) земляники зелёной, произрастающей в степной зоне оренбургского Предуралья. Идентифицированы флавоноиды: кверцетин, рутин, кверцитрин, гиперозид, а из фенолокислот кофейная, хлорогеновая, неохлорогеновая. Показано, что содержание полифенолов зависит от зональности и местообитания растений. Изложены результаты влияния водного экстракта лекарстве...

  6. Controlling light-use by Rhodobacter capsulatus continuous cultures in a flat-panel photobioreactor

    NARCIS (Netherlands)

    Hoekema, S.; Douma, R.D.; Janssen, M.G.J.; Tramper, J.; Wijffels, R.H.

    2006-01-01

    The main bottleneck in scale-up of phototrophic fermentation is the low efficiency of light energy conversion to the desired product, which is caused by an excessive dissipation of light energy to heat. The photoheterotrophic formation of hydrogen from acetate and light energy by the microorganism

  7. Early Bacteriopheophytin Reduction in Charge Separation in Reaction Centers of Rhodobacter sphaeroides

    NARCIS (Netherlands)

    Zhu, J.; van Stokkum, I.H.M.; Paparelli, L.; Jones, M.R.; Groot, M.L.

    2013-01-01

    A question at the forefront of biophysical sciences is, to what extent do quantum effects and protein conformational changes play a role in processes such as biological sensing and energy conversion? At the heart of photosynthetic energy transduction lie processes involving ultrafast energy and

  8. Stoichiometry of ATP hydrolysis and chlorophyllide formation of dark-operative protochlorophyllide oxidoreductase from Rhodobacter capsulatus

    Energy Technology Data Exchange (ETDEWEB)

    Nomata, Jiro [Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601 (Japan); Terauchi, Kazuki [Department of Life Sciences, Ritsumeikan University, Kusatsu, Shiga, 525-8577 (Japan); Fujita, Yuichi, E-mail: fujita@agr.nagoya-u.ac.jp [Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601 (Japan)

    2016-02-12

    Dark-operative protochlorophyllide (Pchlide) oxidoreductase (DPOR) is a nitrogenase-like enzyme catalyzing a reduction of the C17 = C18 double bond of Pchlide to form chlorophyllide a (Chlide) in bacteriochlorophyll biosynthesis. DPOR consists of an ATP-dependent reductase component, L-protein (a BchL dimer), and a catalytic component, NB-protein (a BchN–BchB heterotetramer). The L-protein transfers electrons to the NB-protein to reduce Pchlide, which is coupled with ATP hydrolysis. Here we determined the stoichiometry of ATP hydrolysis and the Chlide formation of DPOR. The minimal ratio of ATP to Chlide (ATP/2e{sup –}) was 4, which coincides with that of nitrogenase. The ratio increases with increasing molar ratio of L-protein to NB-protein. This profile differs from that of nitrogenase. These results suggest that DPOR has a specific intrinsic property, while retaining the common features shared with nitrogenase. - Highlights: • The stoichiometry of nitrogenase-like protochlorophyllide reductase was determined. • The minimal ATP/2e{sup –} ratio was 4, which coincides with that of nitrogenase. • The ATP/2e{sup –} ratio increases with increasing L-protein/NB-protein molar ratio. • DPOR has an intrinsic property, but retains features shared with nitrogenase.

  9. Absorbance changes accompanying the fast fluorescence induction in the purple bacterium Rhodobacter sphaeroides

    Czech Academy of Sciences Publication Activity Database

    Bína, David; Litvín, Radek; Vácha, František

    2010-01-01

    Roč. 105, č. 2 (2010), s. 115-121 ISSN 0166-8595 R&D Projects: GA AV ČR IAA608170603 Institutional research plan: CEZ:AV0Z50510513 Keywords : Photosynthesis * Charge separation * Membrane potential Subject RIV: CE - Biochemistry Impact factor: 2.410, year: 2010

  10. Proton conduction within the reaction centers of Rhodobacter capsulatus: the electrostatic role of the protein.

    OpenAIRE

    Maróti, P; Hanson, D K; Baciou, L; Schiffer, M; Sebban, P

    1994-01-01

    Light-induced charge separation in the photosynthetic reaction center results in delivery of two electrons and two protons to the terminal quinone acceptor QB. In this paper, we have used flash-induced absorbance spectroscopy to study three strains that share identical amino acid sequences in the QB binding site, all of which lack the protonatable amino acids Glu-L212 and Asp-L213. These strains are the photosynthetically incompetent site-specific mutant Glu-L212/Asp-L213-->Ala-L212/Ala-L213 ...

  11. Proton conduction within the reaction centers of Rhodobacter capsulatus: the electrostatic role of the protein.

    Science.gov (United States)

    Maróti, P; Hanson, D K; Baciou, L; Schiffer, M; Sebban, P

    1994-06-07

    Light-induced charge separation in the photosynthetic reaction center results in delivery of two electrons and two protons to the terminal quinone acceptor QB. In this paper, we have used flash-induced absorbance spectroscopy to study three strains that share identical amino acid sequences in the QB binding site, all of which lack the protonatable amino acids Glu-L212 and Asp-L213. These strains are the photosynthetically incompetent site-specific mutant Glu-L212/Asp-L213-->Ala-L212/Ala-L213 and two different photocompetent derivatives that carry both alanine substitutions and an intergenic suppressor mutation located far from QB (class 3 strain, Ala-Ala + Arg-M231-->Leu; class 4 strain, Ala-Ala + Asn-M43-->Asp). At pH 8 in the double mutant, we observe a concomitant decrease of nearly 4 orders of magnitude in the rate constants of second electron and proton transfer to QB compared to the wild type. Surprisingly, these rates are increased to about the same extent in both types of suppressor strains but remain > 2 orders of magnitude smaller than those of the wild type. In the double mutant, at pH 8, the loss of Asp-L213 and Glu-L212 leads to a substantial stabilization (> or = 60 meV) of the semiquinone energy level. Both types of compensatory mutations partially restore, to nearly the same level, the original free energy difference for electron transfer from primary quinone QA to QB. The pH dependence of the electron and proton transfer processes in the double-mutant and the suppressor strains suggests that when reaction centers of the double mutant are shifted to lower pH (1.5-2 units), they function like those of the suppressor strains at physiological pH. Our data suggest that the main effect of the compensatory mutations is to partially restore the negative electrostatic environment of QB and to increase an apparent "functional" pK of the system for efficient proton transfer to the active site. This emphasizes the role of the protein in tuning the electrostatic environment of its cofactors and highlights the possible long-range electrostatic effects.

  12. Complete genome sequence of the photosynthetic purple nonsulfur bacterium Rhodobacter capsulatus SB 1003

    Czech Academy of Sciences Publication Activity Database

    Strnad, Hynek; Lapidus, A.; Pačes, Jan; Ulbrich, P.; Vlček, Čestmír; Pačes, Václav; Haselkorn, R.

    2010-01-01

    Roč. 192, č. 13 (2010), s. 3545-3546 ISSN 0021-9193 R&D Projects: GA MŠk 1M0520 Institutional research plan: CEZ:AV0Z50520514 Keywords : transfer-RNA genes * identification * annotation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.726, year: 2010

  13. Proximate biochemical composition and caloric potential in the raft-grown green mussel Perna viridis

    Digital Repository Service at National Institute of Oceanography (India)

    Rivonker, C.U.; Parulekar, A.H.

    The biochemical components of the mussel tissue, cultured on the raft were estimated. The range of variation in the content of moisture, protein, carbohydrates, lipid, organic carbon and ash were 66.8-90.1; 46.2-67.4; 11.7-18.6; 2.9-7.4; 19...

  14. Burrow ventilation and associated porewater irrigation by the polychaete Marenzelleria viridis

    DEFF Research Database (Denmark)

    Quintana, Cintia Organo; Hansen, Torben; Delefosse, Matthieu

    2011-01-01

    presented muscular pumping in time averaged rates of 0.15 ml min−1. Oxygen needle electrodes positioned above the burrow openings revealed that muscular undulation of the worm body pumps anoxic water out of the burrow. On the other hand, microscope observations of the animal showed that ventilation...... be about 0.16 ml min−1. Since the cilia pumping into the burrow occurs in periods of 24±12 min and at 50–70% of the measured time, considerable amounts of water from deeper sediments may percolate upwards to the sediment surface. This water is rich in reduced compounds and nutrients and may have important...

  15. Environment-dependence of behavioural consistency in adult male European green lizards (Lacerta viridis)

    OpenAIRE

    Horváth, Gergely; Mészáros, Boglárka; Urszán, Tamás János; Bajer, Katalin; Molnár, Orsolya; Garamszegi, László Z.; Herczeg, Gábor

    2017-01-01

    Understanding the background mechanisms affecting the emergence and maintenance of consistent between-individual variation within population in single (animal personality) or across multiple (behavioural syndrome) behaviours has key importance. State-dependence theory suggests that behaviour is ‘anchored’ to individual state (e.g. body condition, gender, age) and behavioural consistency emerges through behavioural-state feedbacks. A number of relevant state variables are labile (e.g. body con...

  16. Antifouling activity of Indian marine invertebrate against the green mussel Perna viridis L.

    Digital Repository Service at National Institute of Oceanography (India)

    PrabhaDevi; Jayasree, V.; Naik, C.G.; Parameswaran, P.S.; Raveendran, T.V.; Kamat, S.Y.

    antifouling activ- ity, which was evident from the few observations made in the present study, for example, C. kremfi collected from Kalpeni showed moderate activity, while that from Kada- math showed no activity. Similarly, C. pachyclados from Kalpeni showed... moderate activity, while that from Kada- math showed strong activity. This was also the case with Suberogorgia suberosa from Mandapam and Beyt Dwarka, which showed no and positive activity, respectively. Intra- specific variability in the chemically...

  17. Biochemical markers of oxidative stress in Perna viridis exposed to mercury and temperature

    Digital Repository Service at National Institute of Oceanography (India)

    Verlecar, X.N.; Jena, K.B.; Chainy, G.B.N.

    peroxidation (LPX). Increased activities of antioxidants such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR) and glutathione-S-transferase (GST) both in gills and digestive glands under long...

  18. Modulation of antioxidant defences in digestive gland of Perna viridis (L.), on mercury exposures

    Digital Repository Service at National Institute of Oceanography (India)

    Verlecar, X.N.; Jena, K.B.; Chainy, G.B.N.

    by defense sys- tems. Antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR) and glutathione S-transferase (GST) and non enzymatic antioxidant molecules such as reduced glutathione (GSH...- sures include lipid peroxidation (LPX), protein carbonyl (PC), hydrogen peroxide (H 2 O 2 ), GSH, ascorbic acid (ASA) and antioxidant enzymes such as SOD, CAT, GPX, GR and GST. In addition DNA strand breaks, as an index of genotoxic stress and MT...

  19. Application of oxidative stress indices in natural populations of Perna viridis as biomarker of environmental pollution

    Digital Repository Service at National Institute of Oceanography (India)

    Jena, K.B.; Verlecar, X.N.; Chainy, G.B.N.

    % inhibition of oxidation of NADH in the reaction. The reaction rate was recorded at 340 nm and expressed as Units/mg protein. Catalase (CAT) activity was determined according to Aebi (1974). The method was based on the decomposition rate of hydrogen peroxide... was significantly higher than the reference site (BB; Fig. 2C). In case of digestive gland, SOD activity was significantly increased at MH and ML than at BB (Fig. 2D). 4.4. Catalase CAT in gill as well as in digestive gland showed much higher activity at MH and ML...

  20. Biomarkers of petroleum contamination in the digestive gland of Perna viridis (L.)

    Digital Repository Service at National Institute of Oceanography (India)

    Verlecar, X.N.; Jena, K.B.; Desai, S.R.; Das, P.B.; Chainy, G.B.N.

    metabolites as well as reactive oxygen species (ROS) causing oxidative damage to cells (18,19). Th is induces antioxidative responses to protect cells against the unfavorable eff ects of ROS. To this end, superoxide dismutase (SOD), catalase (CAT... in the digestive gland. Th e parameters measured included LPX, PC, hydrogen peroxide (H2O2), GSH, ASA, and antioxidant enzymes such as SOD, CAT, GPX, GR, and GST as indices of oxidative stress, and DNA strand breaks as an index of genotoxic stress. Th ese...

  1. Radioprotection against DNA damage by an extract of Indian green mussel, Perna viridis (L.)

    Digital Repository Service at National Institute of Oceanography (India)

    Kumaran, S.P.; Kutty, B.C.; Chatterji, A.; Parameswaran, P.S.; Mishra, K.P.

    -irradiation Prevention of DNA damage both in plasmid and lymphocytes and cell death in lymphocytes appears correlated with reduction of oxidatively generated free radicals It is concluded that protection against radiation-induced cell death and DNA damage by MH...

  2. Antioxidative potential of Perna viridis and its protective role against ROS induced lipidperoxidation and protein carbonyl

    Digital Repository Service at National Institute of Oceanography (India)

    Jena, K.B.; Jagtap, T.G.; Verlecar, X.N.

    ) such as hydrogen peroxide (H2O2) and hydroxyl radical (OH•), and inhibition of lipid peroxidation (LPX) and protein carbonyl (PC). The scavenging activity of DPPH radical, H sub(2) O sub(2) and OH• radicals increased in dose dependent manner. The reducing power...

  3. A novel DNase like compound that inhibits virus propagation from Asian green mussel, Perna viridis (Linn.)

    Digital Repository Service at National Institute of Oceanography (India)

    Iqbal, A.N.M.Z.; Khan, M.S.

    to counteract some viruses. Keywords: Antiviral property, Bivalves, DNase-like bioactivity, Plasmid pBR 322 Virus mediated pathological conditions such as Chickenpox (Varicella zoster virus, VZV), Japanese encephalitis, Chickungunya, Dengue, infectious... is an object of future research endeavor. DNAse like PPC with an antiviral property can be a potential candidate to develop an effective drugs against the DNA viruses like varicella zoster virus and Herpes viruses. Detailed work is underway to further...

  4. Growth parameters in the cultured green mussel Perna viridis L. from the Zuari Estuary, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Rivonker, C.U.; Sreepada, R.A.; Parulekar, A.H.

    inverse relationship. In contrast, growth expressed in terms of weight was significantly influencEd. by chl-a and DO. It was also observed that chl-a either singly or in combination with particulate organic matter had significant effect on growth...

  5. Characterization of glutathione peroxidase diversity in the symbiotic sea anemone Anemonia viridis

    OpenAIRE

    Pey , Alexis; Zamoum , Thamilla; Christen , Richard; Merle , Pierre-Laurent; Furla , Paola

    2016-01-01

    International audience; Cnidarians living in symbiosis with photosynthetic dinoflagellates (commonly named zooxanthellae) are exposed to high concentrations of reactive oxygen species (ROS) upon illumination. To quench ROS production, both the cnidarian host and zooxanthellae express a full suite of antioxidant enzymes. Studying antioxidative balance is therefore crucial to understanding how symbiotic cnidarians cope with ROS production. We characterized glutathione peroxidases (GPx) in the s...

  6. Cytogenetic studies in green mussel, Perna viridis (Mytiloida: Pteriomorphia), from West Coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Iqbal, A.N.M.Z.; Khan, M.S.; Goswami, U.

    species belonging to Pulmonate Communicated by S.W.A. Naqvi. A. N. Muhammed Zafar Iqbal (&) C1 M. S. Khan C1 U. Goswami Biological Oceanography Division, National Institute of Oceanography, Dona Paula, Goa, India e-mail: zafar_ian@yahoo.co.uk; zafarin... aquaculture productivity, with annual yield of 3,22,234 tonnes in 2004 (FAO 2004) and holds the 19th position in the worldwide mariculture industry. Karyotypic features have been analyzed and documented in detail using con- ventional staining, C-banding and Ag...

  7. Preparation of Nanoparticles by Electroagulation From Soluble Exopolysaccharide Produced by Claviceps viridis

    Czech Academy of Sciences Publication Activity Database

    Flieger, Miroslav; Kantorová, Michaela; Benada, Oldřich; Kofroňová, Olga; Sobotka, Miroslav; Cvak, Jan; Votruba, Jaroslav

    2004-01-01

    Roč. 85, č. 2 (2004), s. 234-236 ISSN 0006-3592 R&D Projects: GA ČR GA525/00/1283 Institutional research plan: CEZ:AV0Z5020903 Keywords : electroagulation * exopolysaccharides * nanoparticles Subject RIV: EE - Microbiology, Virology Impact factor: 2.216, year: 2004

  8. Eight-Membered Cyclic 1,2,3-Trithiocane Derivatives from Perophora viridis, an Atlantic Tunicate

    Czech Academy of Sciences Publication Activity Database

    Řezanka, Tomáš; Dembitsky, V. M.

    - (2002), s. 2400-2404 ISSN 1434-193X Institutional research plan: CEZ:AV0Z5020903 Keywords : natural * products * sulfur heterocycles Subject RIV: EE - Microbiology, Virology Impact factor: 2.195, year: 2002

  9. Relative toxicity of oil dispersants to Mytilus viridis and Macrobrachium idella

    Digital Repository Service at National Institute of Oceanography (India)

    DeSilva, C.; Row, A.

    ) was almost identical for both the species tested, although there was a significant shift in the range of LC sub(50) values, indicating that one species is less sensitive than the other. Oil dispersant mixtures were less toxic than the dispersants alone...

  10. Dimers of light-harvesting complex 2 from Rhodobacter sphaeroides characterized in reconstituted 2D crystals with atomic force microscopy

    NARCIS (Netherlands)

    Liu, Lu-Ning; Aartsma, Thijs J.; Frese, Raoul N.

    Microscopic and light spectroscopic investigations on the supramolecular architecture of bacterial photosynthetic membranes have revealed the photosynthetic protein complexes to be arranged in a densely packed energy-transducing network. Protein packing may play a determining role in the formation

  11. Dynamics of energy transfer from lycopene to bacteriochlorophyll in genetically-modified LH2 complexes of Rhodobacter sphaeroides.

    Science.gov (United States)

    Hörvin Billsten, H; Herek, J L; Garcia-Asua, G; Hashøj, L; Polívka, T; Hunter, C N; Sundström, V

    2002-03-26

    LH2 complexes from Rb. sphaeroides were modified genetically so that lycopene, with 11 saturated double bonds, replaced the native carotenoids which contain 10 saturated double bonds. Tuning the S1 level of the carotenoid in LH2 in this way affected the dynamics of energy transfer within LH2, which were investigated using both steady-state and time-resolved techniques. The S1 energy of lycopene in n-hexane was determined to be approximately 12 500 +/- 150 cm(-1), by direct measurement of the S1-S2 transient absorption spectrum using a femtosecond IR-probing technique, thus placing an upper limit on the S1 energy of lycopene in the LH2 complex. Fluorescence emission and excitation spectra demonstrated that energy can be transferred from lycopene to the bacteriochlorophyll molecules within this LH2 complex. The energy-transfer dynamics within the mutant complex were compared to wild-type LH2 from Rb. sphaeroides containing the carotenoid spheroidene and from Rs. molischianum, in which lycopene is the native carotenoid. The results show that the overall efficiency for Crt --> B850 energy transfer is approximately 80% in lyco-LH2 and approximately 95% in WT-LH2 of Rb. sphaeroides. The difference in overall Crt --> BChl transfer efficiency of lyco-LH2 and WT-LH2 mainly relates to the low efficiency of the Crt S(1) --> BChl pathway for complexes containing lycopene, which was 20% in lyco-LH2. These results show that in an LH2 complex where the Crt S1 energy is sufficiently high to provide efficient spectral overlap with both B800 and B850 Q(y) states, energy transfer via the Crt S1 state occurs to both pigments. However, the introduction of lycopene into the Rb. sphaeroides LH2 complex lowers the S1 level of the carotenoid sufficiently to prevent efficient transfer of energy to the B800 Q(y) state, leaving only the Crt S1 --> B850 channel, strongly suggesting that Crt S1 --> BChl energy transfer is controlled by the relative Crt S1 and BChl Q(y) energies.

  12. Sequential assembly of photosynthetic units in Rhodobacter sphaeroides as revealed by fast repetition rate analysis of variable bacteriochlorophyll a fluorescence

    Czech Academy of Sciences Publication Activity Database

    Koblížek, Michal; Shih, J. D.; Breitbart, S. I.; Ratcliffe, E. C.; Kolber, Z. S.; Hunter, C. N.; Niederman, R. A.

    2005-01-01

    Roč. 1706, - (2005), s. 220-231 ISSN 0006-3002 R&D Projects: GA ČR GP206/03/P079; GA MŠk LN00A141 Institutional research plan: CEZ:AV0Z50200510 Keywords : membrane development * light-harvesing complex * photosynthetic membrane Subject RIV: EE - Microbiology, Virology

  13. A molecular genetic analysis of carotenoid biosynthesis and the effects of carotenoid mutations on other photosynthetic genes in Rhodobacter capsulatus

    International Nuclear Information System (INIS)

    Armstrong, G.A.

    1989-04-01

    The nine known R. capsulatus carotenoid genes are contained within the 46 kilobase (kb) photosynthesis gene cluster. An 11 kb subcluster containing eight of these genes has been cloned and its nucleotide sequence determined. A new gene, crtK, has been located in the middle of the subcluster. The carotenoid gene cluster contains sequences homologous to Escherichia coli ω 70 promoters, rho-independent transcription terminators, and prokaryotic transcriptional factor binding sites. The phenotypes and genotypes of ten transposon Tn5.7 insertion mutations within the carotenoid gene cluster have been analyzed, by characterization of the carotenoids accumulated and high resolution mapping of the Tn5.7 insertions. The enzymatic blockages in previously uncharacterized early carotenoid mutants have been determined using a new in vitro synthesis system, suggesting specific roles for the CrtB and CrtE gene products. The expression of six of the eight carotenoid genes in the cluster is induced upon the shift from dark chemoheterotrophic to anaerobic photosynthetic growth. The magnitude of the induction is equivalent to that of genes encoding structural photosynthesis polypeptides, although the carotenoid genes are induced earlier after the growth shift. Different means of regulating photosynthesis genes in R. capsulatus are discussed, and a rationale for the temporal pattern of expression of the carotenoid genes during photosynthetic adaptation is presented. Comparison of the deduced amino acid sequences of the two dehydrogenases of the R. capsulatus carotenoid biosynthesis pathway reveals two regions of strong similarity. The effect of carotenoid mutations on the photosynthetic phenotype has been studied by examining growth rates, pigments, pigment-protein complexes and gene expression for a complete set of carotenoid mutants. 161 refs

  14. Photo-fermentational hydrogen production of Rhodobacter sp. KKU-PS1 isolated from an UASB reactor

    Directory of Open Access Journals (Sweden)

    Thitirut Assawamongkholsiri

    2015-05-01

    Conclusions: KKU-PS1 can produce hydrogen from at least 8 types of organic acids. By optimizing pH and temperature, a maximal hydrogen production by this strain was obtained. Additionally, by optimizing the light intensity, Rm was increased by approximately two fold and the lag phase of hydrogen production was shortened.

  15. A molecular genetic analysis of carotenoid biosynthesis and the effects of carotenoid mutations on other photosynthetic genes in Rhodobacter capsulatus

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, G.A.

    1989-04-01

    The nine known R. capsulatus carotenoid genes are contained within the 46 kilobase (kb) photosynthesis gene cluster. An 11 kb subcluster containing eight of these genes has been cloned and its nucleotide sequence determined. A new gene, crtK, has been located in the middle of the subcluster. The carotenoid gene cluster contains sequences homologous to Escherichia coli ..omega../sup 70/ promoters, rho-independent transcription terminators, and prokaryotic transcriptional factor binding sites. The phenotypes and genotypes of ten transposon Tn5.7 insertion mutations within the carotenoid gene cluster have been analyzed, by characterization of the carotenoids accumulated and high resolution mapping of the Tn5.7 insertions. The enzymatic blockages in previously uncharacterized early carotenoid mutants have been determined using a new in vitro synthesis system, suggesting specific roles for the CrtB and CrtE gene products. The expression of six of the eight carotenoid genes in the cluster is induced upon the shift from dark chemoheterotrophic to anaerobic photosynthetic growth. The magnitude of the induction is equivalent to that of genes encoding structural photosynthesis polypeptides, although the carotenoid genes are induced earlier after the growth shift. Different means of regulating photosynthesis genes in R. capsulatus are discussed, and a rationale for the temporal pattern of expression of the carotenoid genes during photosynthetic adaptation is presented. Comparison of the deduced amino acid sequences of the two dehydrogenases of the R. capsulatus carotenoid biosynthesis pathway reveals two regions of strong similarity. The effect of carotenoid mutations on the photosynthetic phenotype has been studied by examining growth rates, pigments, pigment-protein complexes and gene expression for a complete set of carotenoid mutants. 161 refs.

  16. IncreasingpCO2correlates with low concentrations of intracellular dimethylsulfoniopropionate in the sea anemoneAnemonia viridis

    OpenAIRE

    Borell, Esther M.; Steinke, Michael; Horwitz, Rael; Fine, Maoz

    2014-01-01

    Marine anthozoans maintain a mutualistic symbiosis with dinoflagellates that are prolific producers of the algal secondary metabolite dimethylsulfoniopropionate (DMSP), the precursor of the climate-cooling trace gas dimethyl sulfide (DMS). Surprisingly, little is known about the physiological role of DMSP in anthozoans and the environmental factors that regulate its production. Here, we assessed the potential functional role of DMSP as an antioxidant and determined how future increases in sea...

  17. BUDIDAYA KERANG HIJAU (Perna viridis L. DENGAN METODE DAN KEPADATAN BERBEDA DI PERAIRAN PESISIR KUALA LANGSA, ACEH

    Directory of Open Access Journals (Sweden)

    Andi Sagita

    2017-05-01

    Full Text Available Kerang hijau merupakan komoditas budidaya laut yang sangat prospektif untuk dikembangkan pada suatu sistem budidaya, karena dapat dilakukan dengan biaya produksi yang rendah namun menghasilkan profitabilitas yang tinggi. Penelitian ini bertujuan untuk mengetahui metode dan kepadatan yang paling optimal untuk budidaya kerang hijau di perairan pesisir Kuala Langsa, Aceh. Metode penelitian menggunakan rancangan acak lengkap faktorial yang terdiri atas faktor metode (long line dan stick dan faktor kepadatan (20, 30, dan 40 individu/kantong 5,30 L, masing-masing diulang sebanyak empat kali. Berdasarkan sidik ragam data Specific Growth Rate (SGR dari panjang (SGL L dan bobot (SGR W menunjukkan semua perlakuan metode, kepadatan dan interaksi berbeda signifikan pada taraf uji 5% (P<0,05, di mana perlakuan yang paling optimal yaitu perlakuan metode long line dengan kepadatan 20 individu/kantong 5,30 L diperoleh rata-rata nilai SGR (L sebesar 0,86 ± 0,01%/hari dan SGR (W sebesar 1,18 ± 0,04%/hari dengan sintasan mencapai 92,50 ± 2,89%. Parameter kualitas perairan selama periode budidaya masih sesuai untuk mendukung kehidupan kerang hijau di mana suhu berkisar 27,5-34,0°C; salinitas 28,5-33,0 ppt; pH 7,8-8,6; dan oksigen terlarut 4,5-6,5 mg/L; serta kecepatan arus 0,1-0,3 m/s. Budidaya kerang hijau dengan metode long line pada kepadatan 20 individu/kantong 5,30 L merupakan pola budidaya yang paling optimal untuk diterapkan di perairan pesisir Kuala Langsa, Aceh. Green mussel is a very prospective marine aquaculture commodity due to its low cost production but with high profitability. This research aimed to determine the most optimal method and densities for green mussel culture in coastal waters of Kuala Langsa, Aceh. The research used a completely randomized factorial design consisting of methods factor (long line and stick and densities factor (20, 30, and 40 individuals/basket 5.30 L, each repeated four times. Based on the variance analysis of specific growth rate (SGR data of the length (SGR L and weight (SGR W, all treatments of different methods and densities as well as their interactions were significant different (P<0.05. This study suggested that long line method with a densities of 20 individuals/basket 5.30 L was found to be the most optimal treatment for green mussel culture in coastal waters of Kuala Langsa. With this long line method an average SGR (L value of 0.86 ± 0.01%/day, SGR (W value of 1.18 ± 0.04%/day, and survival rate of 92.50 ± 2.89% were obtained. Water quality parameters during the culture period are still within the suitable range for green mussel culture, with the range of temperature 27.5-34.0°C, salinity 28.5-33.0 ppt, pH 7.8-8.6, dissolved oxygen 4.5-6.5 mg/L, and current velocity 0.1-0.3 m/s.

  18. Seasonal variation of oxidative biomarkers in gills and digestive gland of green-lipped mussel Perna viridis from Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Verlecar, X.N.; Jena, K.B.; Chainy, G.B.N.

    peroxidation (LPX), hydrogen peroxide (H sub(2) O sub(2)), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione transferase (GST), glutathione reductase (GR), reduced glutathione (GSH) and ascorbic acid (ASA) were measured...

  19. Influence of rearing water temperature on induced gonadal development and spawning behaviour of tropical green mussel, Perna viridis

    Directory of Open Access Journals (Sweden)

    Parathattil Rathan Sreedevi

    2014-09-01

    Conclusion: According to the present study temperature induced spawning method is very simple and cost effective and can accelerate the production of mussel seeds in hatchery units and further stock improvement through genetic manipulation.

  20. Effect of genotype and environment on branching in weedy green millet (Setaria viridis) and domesticated foxtail millet (Setaria italica) (Poaceae).

    Science.gov (United States)

    Doust, Andrew N; Kellogg, Elizabeth A

    2006-04-01

    Many domesticated crops are derived from species whose life history includes weedy characteristics, such as the ability to vary branching patterns in response to environmental conditions. However, domesticated crop plants are characterized by less variable plant architecture, as well as by a general reduction in vegetative branching compared to their progenitor species. Here we examine weedy green millet and its domesticate foxtail millet that differ in the number of tillers (basal branches) and axillary branches along each tiller. Branch number in F(2:3) progeny of a cross between the two species varies with genotype, planting density, and other environmental variables, with significant genotype-environment interactions (GEI). This is shown by a complex pattern of reaction norms and by variation in the pattern of significant quantitative trait loci (QTL) amongst trials. Individual and joint analyses of high and low density trials indicate that most QTL have significant GEI. Dominance and epistasis also explain some variation in branching. Likely candidate genes underlying the QTL (based on map position and phenotypic effect) include teosinte branched1 and barren stalk1. Phytochrome B, which has been found to affect response to shading in other plants, explains little or no variation. Much variation in branching is explained by QTL that do not have obvious candidate genes from maize or rice.

  1. The three-dimensional structures of bacterial reaction centers.

    Science.gov (United States)

    Olson, T L; Williams, J C; Allen, J P

    2014-05-01

    This review presents a broad overview of the research that enabled the structure determination of the bacterial reaction centers from Blastochloris viridis and Rhodobacter sphaeroides, with a focus on the contributions from Duysens, Clayton, and Feher. Early experiments performed in the laboratory of Duysens and others demonstrated the utility of spectroscopic techniques and the presence of photosynthetic complexes in both oxygenic and anoxygenic photosynthesis. The laboratories of Clayton and Feher led efforts to isolate and characterize the bacterial reaction centers. The availability of well-characterized preparations of pure and stable reaction centers allowed the crystallization and subsequent determination of the structures using X-ray diffraction. The three-dimensional structures of reaction centers revealed an overall arrangement of two symmetrical branches of cofactors surrounded by transmembrane helices from the L and M subunits, which also are related by the same twofold symmetry axis. The structure has served as a framework to address several issues concerning bacterial photosynthesis, including the directionality of electron transfer, the properties of the reaction center-cytochrome c 2 complex, and the coupling of proton and electron transfer. Together, these research efforts laid the foundation for ongoing efforts to address an outstanding question in oxygenic photosynthesis, namely the molecular mechanism of water oxidation.

  2. A structural basis for electron transfer in bacterial photosynthesis

    International Nuclear Information System (INIS)

    Norris, J.R.; DiMagno, T.J.; Angerhofer, A.; Chang, C.H.; El-Kabbani, O.; Schiffer, M.

    1989-01-01

    Triplet data for the primary donor in single crystals of bacterial reaction centers of Rhodobacter sphaeroides and Rhodopseudomonas viridis are interpreted in terms of the corresponding x-ray structures. The analysis of electron paramagnetic resonance data from single crystals (triplet zero field splitting and cation and triplet linewidth of the primary special pair donor of bacterial reaction centers) is extended to systems of a non-crystalline nature. A unified interpretation based on frontier molecular orbitals concludes that the special pair behaves like a supermolecule in all wild-type bacteria investigated here. However, in heterodimers of Rb. capsulatus (His M200 changed to Leu or Phe with the result that the M-half of the special pair is converted to bacteriopheophytin) the special pair possesses the EPR properties more appropriately described in terms of a monomer. In all cases the triplet state and cation EPR properties appear to be dominated by the highest occupied molecular orbitals. These conclusions derived from EPR experiments are supplemented by data from Stark spectroscopy of reaction centers from Rb. capsulatus. 41 refs., 3 tabs

  3. [Influence of LDAO on the conformation and release of bacteriochlorophyll of peripheral light-harvesting complex (LH2) from Rhodobacter azotoformans].

    Science.gov (United States)

    Zhao, Gen-gui; Dong, Yan-min; Yang, Su-ping; Jiao, Nian-zhi; Qu, Yin-bo

    2010-10-01

    The aim of this study is to reveal the interaction relationships between lauryl dimethylamine N-oxide (LDAO) and peripheral light-harvesting complex (LH2) as well as the influence of LDAO on structure and function of LH2. In the present work, the effects of LDAO on the conformation and release processes of bacteriochlorophyll (BChl) of LH2 when incubated under different temperature and pH in the presence and absence of LDAO were investigated by spectroscopy. The results indicated that (1) the presence of LDAO resulted in alterations in the conformation, alpha-helix content, and spectra of Tyr and B850 band of LH2 at room temperature and pH 8.0. Moreover, energy transfer efficiency of LH2 was enhanced markedly in the presence of LDAO. (2) At 60 degrees C, both the B800 and B850 band of LH2 were released and transited into free BChl at pH 8.0. However, the release rates of bacteriochlorophylls of B800 and B850 band from LH2 were slowed down and the release processes were changed when incubated in the presence of LDAO. Hence, the stability of LH2 was improved in the presence of LDAO. (3) The accelerated release processes of bacteriochlorophylls of B800 and B850 band of LH2 were induced to transform into bacteriopheophytin (BPhe) and free BChl by LDAO in strong acid and strong alkalic solution at room temperature. However, the kinetic patterns of the B800 and B850 band were remarkably different. The release and self-assemble processes of B850 in LH2 were observed in strong acid solution without LDAO. Therefore, the different release behaviors of B800 and B850 of LH2 are induced by LDAO under different extreme environmental conditions.

  4. PucC and LhaA direct efficient assembly of the light-harvesting complexes in Rhodobacter sphaeroides

    DEFF Research Database (Denmark)

    Mothersole, David; Jackson, Philip J.; Vasilev, Cvetelin

    2016-01-01

    . Here we investigate the assembly of light-harvesting LH2 and reaction centre-light-harvesting1-PufX (RC-LH1-PufX) photosystem complexes using spectroscopy, pull-downs, native gel electrophoresis, quantitative mass spectrometry and fluorescence lifetime microscopy to characterise a series of lha......A and pucC mutants. LhaA and PucC are important for specific assembly of LH1 or LH2 complexes, respectively, but they are not essential; the few LH1 subunits found in ΔlhaA mutants assemble to form normal RC-LH1-PufX core complexes showing that, once initiated, LH1 assembly round the RC is cooperative...

  5. Carotenoid biosynthesis in bacteria: In vitro studies of a crt/bch transcription factor from Rhodobacter capsulatus and carotenoid enzymes from Erwinia herbicola

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, D.A.

    1992-11-01

    A putative transcription factor in Rhodobactor capsulatus which binds upstream of the crt and bch pigment biosynthesis operons and appears to play a role in the adaptation of the organism from the aerobic to the anaerobic-photosynthetic growth mode was characterized. Chapter 2 describes the identification of this factor through an in vitro mobility shift assay, as well as the determination of its binding properties and sequence specificity. Chapter 3 focuses on the isolation of this factor. Biochemistry of later carotenoid biosynthesis enzymes derived from the non-photosynthetic bacterium, Erwinia herbicola. Chapter 4 describes the separate overexpression and in vitro analysis of two enzymes involved in the main sequence of the carotenoid biosynthesis pathway, lycopene cyclase and 5-carotene hydroxylase. Chapter 5 examines the overexpression and enzymology of functionally active zeaxanthin glucosyltransferase, an enzyme which carries out a more unusual transformation, converting a carotenoid into its more hydrophilic mono- and diglucoside derivatives. In addition, amino acid homology with other glucosyltransferases suggests a putative binding site for the UDP-activated glucose substrate.

  6. GEOGRAPHIC INFORMATION SYSTEM-BASED MODELING AND ANALYSIS FOR SITE SELECTION OF GREEN MUSSEL, Perna viridis, MARICULTURE IN LADA BAY, PANDEGLANG, BANTEN PROVINCE

    Directory of Open Access Journals (Sweden)

    I Nyoman Radiarta

    2011-06-01

    Full Text Available Green mussel is one of important species cultured in Lada Bay, Pandeglang. To provide a necessary guidance regarding green mussel mariculture development, finding suitable site is an important step. This study was conducted to identify suitable site for green mussel mariculture development using geographic information system (GIS based models. Seven important parameters were grouped into two submodels, namely environmental (water temperature, salinity, suspended solid, dissolve oxygen, and bathymetry and infrastructural (distance to settlement and pond aquaculture. A constraint data was used to exclude the area from suitability maps that cannot be allowed to develop green mussel mariculture, including area of floating net fishing activity and area near electricity station. Analyses of factors and constraints indicated that about 31% of potential area with bottom depth less than 25 m had the most suitable area. This area was shown to have an ideal condition for green mussel mariculture in this study region. This study shows that GIS model is a powerful tool for site selection decision making. The tool can be a valuable tool in solving problems in local, regional, and/or continent areas.

  7. Comparative effects of the blue green algae Nodularia spumigena and a lysed extract on detoxification and antioxidant enzymes in the green lipped mussel (Perna viridis)

    International Nuclear Information System (INIS)

    Davies, Warren R.; Siu, William H.L.; Jack, Ralph W.; Wu, Rudolf S.S.; Lam, Paul K.S.; Nugegoda, Dayanthi

    2005-01-01

    Nodularia spumigena periodically proliferates to cause toxic algal blooms with some aquatic animals enduring and consuming high densities of the blue green algae or toxic lysis. N. spumigena contains toxic compounds such as nodularin and lipopolysaccharides. This current work investigates physiological effects of exposure from bloom conditions of N. spumigena cells and a post-bloom lysis. Biochemical and antioxidative biomarkers were comparatively studied over an acute 3-day exposure. In general, a post-bloom N. spumigena lysis caused opposite physiological responses to bloom densities of N. spumigena. Specifically, increases in glutathione (GSH) and glutathione peroxidase (GPx) and decreases in glutathione S-transferase (GST) were observed from the N. spumigena lysis. In contrast, N. spumigena cell densities decreased GSH and increased GST and lipid peroxidation (LPO) in mussels. Findings also suggest that at different stages of a toxic bloom, exposure may result in toxic stress to specific organs in the mussel

  8. Divergent Host Plant Adaptation Drives the Evolution of Sexual Isolation in the Grasshopper Hesperotettix viridis (Orthoptera: Acrididae) in the Absence of Reinforcement

    Science.gov (United States)

    The beginning stages of lineage divergence can be difficult to detect, as correlations between altered genotypic and phenotypic attributes are often weak early in the process. Shifts in host plant use and divergence in mating signals can lead to sexual isolation and ultimately speciation. To underst...

  9. Seasonal variation of major elements (Ca, Mg) and trace metals (Fe, Cu, Zn, Mn) and cultured mussel Perna viridis L. and seawater in the Dona Paula Bay, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Rivonker, C.U.; Parulekar, A.H.

    The major elements and trace metals were analysed from nussel tissue and the seawater taken from three depths (0, 5 and 9 meters) from the culture site. Range of variation in Ca, Mg, Fe, Cu, Zn and Mn were 226-399; 708-1329; 0.005-0.084; BDL-0...

  10. Atomic force microscopy studies of native photosynthetic membranes.

    Science.gov (United States)

    Sturgis, James N; Tucker, Jaimey D; Olsen, John D; Hunter, C Neil; Niederman, Robert A

    2009-05-05

    In addition to providing the earliest surface images of a native photosynthetic membrane at submolecular resolution, examination of the intracytoplasmic membrane (ICM) of purple bacteria by atomic force microscopy (AFM) has revealed a wide diversity of species-dependent arrangements of closely packed light-harvesting (LH) antennae, capable of fulfilling the basic requirements for efficient collection, transmission, and trapping of radiant energy. A highly organized architecture was observed with fused preparations of the pseudocrystalline ICM of Blastochloris viridis, consiting of hexagonally packed monomeric reaction center light-harvesting 1 (RC-LH1) core complexes. Among strains which also form a peripheral LH2 antenna, images of ICM patches from Rhodobacter sphaeroides exhibited well-ordered, interconnected networks of dimeric RC-LH1 core complexes intercalated by rows of LH2, coexisting with LH2-only domains. Other peripheral antenna-containing species, notably Rhodospirillum photometricum and Rhodopseudomonas palustris, showed a less regular organization, with mixed regions of LH2 and RC-LH1 cores, intermingled with large, paracrystalline domains. The ATP synthase and cytochrome bc(1) complex were not observed in any of these topographs and are thought to be localized in the adjacent cytoplasmic membrane or in inaccessible ICM regions separated from the flat regions imaged by AFM. The AFM images have served as a basis for atomic-resolution modeling of the ICM vesicle surface, as well as forces driving segregation of photosynthetic complexes into distinct domains. Docking of atomic-resolution molecular structures into AFM topographs of Rsp. photometricum membranes generated precise in situ structural models of the core complex surrounded by LH2 rings and a region of tightly packed LH2 complexes. A similar approach has generated a model of the highly curved LH2-only membranes of Rba. sphaeroides which predicts that sufficient space exists between LH2 complexes

  11. NCBI nr-aa BLAST: CBRC-RMAC-01-0051 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-RMAC-01-0051 ref|YP_001033817.1| Ice nucleation protein [Rhodobacter sphaeroid...es 2.4.1] gb|ABA81712.1| Ice nucleation protein [Rhodobacter sphaeroides 2.4.1] YP_001033817.1 0.016 26% ...

  12. NCBI nr-aa BLAST: CBRC-XTRO-01-0470 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-XTRO-01-0470 ref|YP_001033817.1| Ice nucleation protein [Rhodobacter sphaeroid...es 2.4.1] gb|ABA81712.1| Ice nucleation protein [Rhodobacter sphaeroides 2.4.1] YP_001033817.1 1e-12 25% ...

  13. NCBI nr-aa BLAST: CBRC-XTRO-01-0267 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-XTRO-01-0267 ref|YP_001033817.1| Ice nucleation protein [Rhodobacter sphaeroid...es 2.4.1] gb|ABA81712.1| Ice nucleation protein [Rhodobacter sphaeroides 2.4.1] YP_001033817.1 6e-27 25% ...

  14. NCBI nr-aa BLAST: CBRC-TNIG-22-0265 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-TNIG-22-0265 ref|YP_001033817.1| Ice nucleation protein [Rhodobacter sphaeroid...es 2.4.1] gb|ABA81712.1| Ice nucleation protein [Rhodobacter sphaeroides 2.4.1] YP_001033817.1 4e-36 37% ...

  15. NCBI nr-aa BLAST: CBRC-OLAT-26-0102 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-OLAT-26-0102 ref|YP_001033817.1| Ice nucleation protein [Rhodobacter sphaeroid...es 2.4.1] gb|ABA81712.1| Ice nucleation protein [Rhodobacter sphaeroides 2.4.1] YP_001033817.1 0.45 25% ...

  16. NCBI nr-aa BLAST: CBRC-OGAR-01-0310 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-OGAR-01-0310 ref|YP_001033817.1| Ice nucleation protein [Rhodobacter sphaeroid...es 2.4.1] gb|ABA81712.1| Ice nucleation protein [Rhodobacter sphaeroides 2.4.1] YP_001033817.1 4e-07 24% ...

  17. Effect of cooking methods on the micronutrient profile of selected ...

    African Journals Online (AJOL)

    Effect of cooking methods on the micronutrient profile of selected vegetables: okra fruit ( Abelmoshcus esculentus ), fluted pumpkin ( Telfairia occidentalis ), African spinach ( Amarantus viridis ), and scent leaf ( Ocumum gratissimum.

  18. Environmental Compliance Assessment and Management System (ECAMP), U.S. Air Force - German Supplement

    Science.gov (United States)

    1993-10-01

    lizard *Lacerta parva Zwerg-Zaumeidecbse dwad sand lizard *Lacerta. princeps Zagros-Eidecbse Zagros’ lizard *Lacerta viridis Smaragdeidechse green...Moschusbock musk beetle oak beetle Agrilus viridis Buchenprachtkaefer beech beetle (Lsubholzprachtksefer) deciduous tree beetles Anthaxia quadiipunctata...meadow sulfur -all European species not individually listed *Coistra. fragariae Erdbeereule strawberry moth *Consta. veronicae Rotbraune Wintereule red

  19. A Regional Guidebook for Applying the Hydrogeomorphic Approach to Assessing Wetland Functions of Prairie Potholes

    Science.gov (United States)

    2006-05-01

    glyptosperma ribseed sandmat 0 Euphorbia maculata Spotted Spurge 0 Euthamia graminifolia Flat-top Goldentop 6 Fragaria virginiana Wild Strawberry 4...Foxtail UK Setaria viridis Pennisetum viridis Green Foxtail 0 Silene sp. Catchfly UK Sisyrinchium campestre White-eyed Grass 10 Sium suave

  20. First record of a Neozygites species (Zygomycetes:Entomophthorales) infecting springtails (Insecta:Collembola)

    DEFF Research Database (Denmark)

    Steenberg, T.; Eilenberg, J.; Bresciani, J.

    1996-01-01

    A fungal pathogen from the Entomophthorales (Zygomycetes) was discovered in populations of the lucerne flea Sminthurus viridis (Collembola) collected from grassland and leguminous crops in Denmark during July to October. The morphology of the fungus was studied in springtails, collected live, whi...... Conidiobolus coronatus. Verticillium lecanii and Beauveria bassiana (Deuteromycotina:Hyphomycetes) were also isolated from S. viridis....

  1. Subsistence and recreational mussel (Perna perna) collecting in ...

    African Journals Online (AJOL)

    tional collectors are subject to a daily bag limit of 50 mussels and so select ... in subsistence collecting at Kosi Bay is required, but the limited access policy should ... in India (P. viridis and P. indica), Indonesia (P. viridis) and ...... by women in Palau, Micronesia. ... Inshore marine resources and associated opportunities for.

  2. Fire creates host plant patches for monarch butterflies

    Science.gov (United States)

    Baum, Kristen A.; Sharber, Wyatt V.

    2012-01-01

    Monarch butterflies (Danaus plexippus) depend on the presence of host plants (Asclepias spp.) within their breeding range for reproduction. In the southern Great Plains, Asclepias viridis is a perennial that flowers in May and June, and starts to senesce by August. It is locally abundant and readily used by monarchs as a host plant. We evaluated the effects of summer prescribed fire on A. viridis and the use of A. viridis by monarch butterflies. Summer prescribed fire generated a newly emergent population of A. viridis that was absent in other areas. Pre-migrant monarch butterflies laid eggs on A. viridis in summer burned plots in late August and September, allowing adequate time for a new generation of adult monarchs to emerge and migrate south to their overwintering grounds. Thus, summer prescribed fire may provide host plant patches and/or corridors for pre-migrant monarchs during a time when host plant availability may be limited in other areas. PMID:22859559

  3. Photodynamics of BLUF domain proteins: a new class of the biological blue-light photoreceptors

    OpenAIRE

    Zirak Yousefabadi, Peyman

    2008-01-01

    BLUF domains are light sensors of many microorganisms. They are present in the multi-domain proteins e.g. AppA from the phototrophic proteobacterium Rhodobacter sphaeroides, YcgF from Escherichia coli, PAC (photoactive adenylyl cyclase) from the unicellular flagellate Euglena gracilis and single domain proteins e.g. BlrB from Rhodobacter sphaeroides, Slr1694 from cyanobacterium Synechocystis sp.PCC6803, and Tll0078 of the thermophilic unicellular cyanobacterium Thermosynechococcus elongates B...

  4. HEAVY METALS (Ni, Cu, Zn AND Cd CONTENT IN SERUM OF RAT FED GREEN MUSSELS

    Directory of Open Access Journals (Sweden)

    Muhammad Yudhistira Azis

    2015-11-01

    Full Text Available Green mussel (Perna viridis can playing role as bio-indicator or biomonitoring agent for heavy-metalcontaminations in the sea. In this research, the concentrations of four elements Ni, Cu, Zn and Cd in P. viridis and in the serum of rat which orally feed by P. viridis were determined by Atomic Absorption Spectrometry (AAS following dry acid digestion. Parameter analysis was evaluated by determining confidence limit for the obtained results. The result showed that there was a sequence of heavy-metal content in green mussels sample and laboratory rats serum, such as Ni < Cd < Cu < Zn. Keywords: heavy metals, green mussels, laboratory rats serum, AAS

  5. Assessinent of streptomycesgriseo viridis (mycostop as a biocontrol agent for fusarium oxysporum f. sp. dianthiin two cultivars of standard carnation under commercial conditions Evaluación de Streptomyces griseoviridis (MYCOSTOP en el control de Fusarium oxysporum f.sp. dianthi, en dos variedades de clavel estándar bajo condiciones comerciales

    Directory of Open Access Journals (Sweden)

    Ortega Luis Miguel

    1994-06-01

    Full Text Available The research was carried out in a commercial farm, located in Madrid, Cundinamarca. The purpose of the study was to established the rate and irequency of application of Streptomyces griseoviridis (Mycostop in the control of vascular wilt of carnation caused by Fusarium oxysporum f.sp. dianthi. Two experiments were conducted to compare three rates of application (0,025;0,05 and 0,01 g/m2 and
    three intervals of application (1,2 and 4 weeks of
    Mycostop, in two standard carnation varieties. Disease
    progress data were analized by comparing their godness of fit to Gompertz and Monomolecular epidemiological models. By using the simpler linear regression model, the rate of inlection (k and the coefficient of determination (Al were calculated.
    Inlection rates were subjected to analysis of variance.
    The results showed no satislactory control of the disease. Rates and frecuencies of applícation of Streptomyces griseoviridis (Mycostop did not show appreciable differences. Epidemiologically, "k" values were highly homogeneous among the different Mycostop treatments. Streptomyces
    griseoviridisis highly dependent upon culture media
    pH, and it grows only at a pH 016,4 or higher, with an optimal growth at a pH 7,0. No relation was detected between growth of the biocontrol organism and levels of electrical conductivity.La investigación se realizó en un cultivo comercial de clavel localizado en el municipio de Madrid (Cundinamarca, con el objetivo de determinar la dosis y la frecuencia de aplicación de Streptomyces griseoviridis (Mycostop en el control del
    marchitamiento vascular ocasionado por Fusarium oxysporom lsp. dianthi. En el campo, se realizaron dos experimentos simultáneos, para probar diferentes dosis (0,025; 0,05 y 0,1 g/m2 y frecuencias (1, 2 y 4 semanas de aplicación de
    Streptomyces griseoviridis Mycostop en dos variedades de clavel estándar. El análisis estadístico consistió en utilizar algunos modelos epidemiológicos de predicción de la enfermedad, con el fin de observar su progreso en los dilerentes tratamientos. Posteriormente, mediante un análisis
    de regresión lineal simple, se calculó la tasa de infección (k y el coeficiente de determinación (R2, el cual indicó el modelo que más se ajustó a la realidad. Por medio de un análisis de varianza, se compararon las tasas de infección. Los resultados de los experimentos no fueron satislactorios en el
    control de la entermedady no se encontraron diferencias signilicativas entre las dosis y las frecuencias de aplicación de Streptomyces gríseovirídís (Mycostop utilizadas. Un
    comportamiento epidemiológico estadísticamente homogéneo se observó en las curvas de predicción de la enfermedad por bloque. Streptomyces griseoviridises muy dependiente de las condiciones de pH del medio de cultivo, pues, sólo se desarrolló a partir de un pH de 6,4 y con un óptimo
    crecimiento, a 7,0. No se observó una relación entre el desarrollo del organismo y la conductividad eléctrica.

  6. Особенности накопления микроэлементов в тканях Fragaria viridis (Duch. ) Weston

    OpenAIRE

    Докучаева, Юлия; Филиппова, Ася; Сафонов, Максим

    2014-01-01

    Лекарственные растения и препараты растительного происхождения занимают особое место среди средств профилактики и лечения различных заболеваний. Поэтому поиск новых перспективных растений, необходимых для использования в фитотерапии, является актуальной проблемой биологической науки, медицинской практики и ресурсоведения. Основным источником для поиска новых лекарственных растений является ареал средств народной медицины. Наибольший интерес при этом вызывают растения, обладающие комплексным д...

  7. Protein (Cyanobacteria): 281806 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available se with PAS/PAC and GAF sensors Oscillatoria nigro-viridis PCC 7112 MIEESKSIKEKFGVLDSVPVGACLLQDDFVVLFWNTCLEE...YP_007117793.1 1117:4890 1150:2464 1158:318 482564:246 179408:246 diguanylate cycla

  8. Protein (Cyanobacteria): 281805 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available se with PAS/PAC and GAF sensors Oscillatoria nigro-viridis PCC 7112 MYLILPDLYANMTYQIDERLNTSPCGFLSFADDGTIVMVN...YP_007118829.1 1117:4890 1150:2464 1158:318 482564:246 179408:246 diguanylate cycla

  9. Protein (Cyanobacteria): 281754 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available se with PAS/PAC and GAF sensors Oscillatoria nigro-viridis PCC 7112 MLYNNEILPTLTVESSPRSMNILLYKLLSLRRIEYIAVDR...YP_007115817.1 1117:4890 1150:2464 1158:318 482564:246 179408:246 diguanylate cycla

  10. Avifauna of Boni-Dodori National Reserves, Lamu and Garissa ...

    African Journals Online (AJOL)

    observers conducted a 60 min walk along a designated path in open ... rophoneus viridis were recorded in the Boni-Dodori area for the first time. ..... Mouse-coloured Sunbird Cyanomitra veroxii * .... Expedition Field techniques: Bird Surveys.

  11. Archaeological Investigations in the Upper Tombigbee Valley, Mississippi: Phase I. Volume 4.

    Science.gov (United States)

    1983-01-01

    marshelder (sumpweed) (7va) maygrass (Phalaris carol iniana) maypop (Passi flora Incarnata) milkweed (Asclepiodora viridis ) neftles (Urt ica) Ohio...plum (Prunus) wild potato vine (Tpomoea pandurata) wild rice (Zizania aquatica) wild strawberries ( Fragaria ) DATE, FILMED 15, 8 3 DTIC

  12. 7 CFR 319.56-13 - Fruits and vegetables allowed importation subject to specified conditions.

    Science.gov (United States)

    2010-01-01

    ... Fragaria spp Fruit (b)(5)(i). Liberia Pineapple Ananas comosus Fruit (b)(2)(vi). Mali Pineapple Ananas... free from Coccus moestus, C. viridis, Dysmicoccus neobrevipes, Planococcus lilacinus, P. minor, and...

  13. Garrison Dam/Lake Sakakawea Master Plan with Integrated Programmatic Environmental Assessment, Missouri River, Montana: Update of Design Memorandum MGR-107D

    Science.gov (United States)

    2007-12-14

    Toxicodendron radicans), wild strawberry ( Fragaria virginiana), violets (Oxalis violacea), and wild parsley (Lomatium orientale) fill in the...prairie rattlesnakes (Crotalus viridis ), yellowbelly racers (Coluber constrictor), western hognose snake (Heterdon nasicus), and smooth green snakes

  14. An Ecological Land Survey for Fort Wainwright, Alaska,

    Science.gov (United States)

    1999-09-01

    Nutt. DRYOPTERIS FRAGRANS (L.) Schott ALNUS VIRIDIS Villar ssp. CRISPA (Aiton) A. Loeve & D. Loeve GYMNOCARPIUM DRYOPTERIS (L.) Newman BETULA...OCTOPETALA POLYGONUM AMYHIBIUM L. FRAGARIA VIRGINIANA Duchesne POLYGONUM AVICULARE L. GEUM PERINCISUM Rydb. POLYGONUM CONVOLVULUS L. PENTAPHYLLOIDES

  15. Rend Lake, Illinois (Operation and Maintenance).

    Science.gov (United States)

    1976-12-01

    Lippia lanc6Tahta Foxtail, Bristly Setaria Faberfi Foxtail, Green Setaria viridis Foxtail, Yellow Setaria lutescens Galingale C Verus strigosus Garlic...Stickseed, Virginian Hackelia virginiana Stink-Grass Lraqrostis cilialensis Strawberry Fragaria virginiana Sunflower, Common Helianthus annuus Swamp

  16. Corallimorpharia collected during the CANCAP expeditions (1976-1986) in the south-eastern part of the North Atlantic*

    NARCIS (Netherlands)

    Hartog, den J.C.; Ocaña, O.; Brito, A.

    1993-01-01

    Species of Corallimorpharia collected during the CANCAP expeditions in the south-eastern part of the North Atlantic are described and discussed, altogether five species belonging to three genera of Corallimorphidae: the shallow water forms Corynactis viridis Allman, 1846, Pseudocorynactis

  17. Protein (Cyanobacteria): 428320264 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available YP_007118146.1 NC_019730 1117:843 ... 1150:13380 1301283:30256 ... 1158:4799 482564:3448 179408:3448 ... Antibiot...ic biosynthesis monooxygenase Oscillatoria nigro-viridis PCC 7112 MILEAVVLNVKSGCEGD

  18. Phytochemical Screening and Evaluation of the Diuretic Activity of ...

    African Journals Online (AJOL)

    Methods: The aqueous-methanol extract of Mentha viridis was administered to experimental rats at doses of 30, 50 and 100 ... species of flora for food and medicine. It is also ... Preliminary phytochemical analysis. A portion .... The regulation of.

  19. Antifouling activities of marine sedentary invertebrates on some macrofoulers

    Digital Repository Service at National Institute of Oceanography (India)

    Wilsanand, V.; Wagh, A.B.; Bapuji, M.

    pfeifferae, Dercitopsis sp.] against cyprids of the barnacle Balanus amphitrite and green mussel Perna viridis are reported here. All the extracts examined inhibited the settlement of cyprids of B. amphitrite. Toxicity revival studies indicate...

  20. Emarginella, Puncturella, Fissurisepta and Rimula

    African Journals Online (AJOL)

    green ground-colour with a pattern of darker green blotches on the anterior face, ... pointed centrally, set at an angle of 50" to the longitudinal radular axis; exposed shaft ..... Viridis (L.), green + canus (L.), grey; referring to shell colour.

  1. Original Article Microbiological Indoor and Outdoor Air Quality of ...

    African Journals Online (AJOL)

    2011-12-12

    Dec 12, 2011 ... While the mean airborne fungal load in UBTH and Central Hospital in dry season ... Monilla infuscans, Penicillium sp., Candida sp. and Trichoderma viridis while the six (6) .... antibiotic (chloramphenicol) was incorporated into.

  2. Ecology and culturing of edible bivalves in Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Parulekar, A.H.; Nair, S.A.; Ansari, Z.A.; Harkantra, S.N.; Chatterji, A.; Ingole, B.S.; Roy, J.M.

    Environmental characteristics, growth rate, total production and technically feasible methods for the mass cultivation of Meretrix casta, Paphia malabarica, Villorita cyprinoides, Donax incarnatus, Perna viridis, Modiolus metcalfei and Crassostrea...

  3. An Inventory of the Vascular Flora of Fort Greely, Interior Alaska

    Science.gov (United States)

    2001-02-01

    Alnus tenuifolia Nutt. [= Alnus incana (L.) Moench ssp. tenuifolia (Nutt.) Breitung] Alnus viridis Vill. ssp. crispa (Ait.) A. Love & D. Love...Festuca rubra L., in part] Festuca saximontana Rydb. *Festuca vivipara (L.) Smith [= “Festuca vivipara”] Fragaria virginiana Duchesne ssp. glauca...tenuifolia (Nutt.) Breitung] Alnus viridis Vill. ssp. crispa (Ait.) A. Love & D. Love [= Alnus crispa (Ait.) Pursh ssp. crispa] Betula glandulosa Michx. Betula

  4. Terrestrial Biological Inventory, Hillview Drainage and Levee District, Greene and Scott Counties, Illinois.

    Science.gov (United States)

    1982-01-01

    Timothy) Setaria faberi ’derrm. (Giant Foxtail) Setaria u-tescens (Weigel) Hubb. (Yellow Foxtail) Setaria viridis (L.) Beauv. (Green Foxtail) Spartina...Potamore toa nodosus Poir. (Long-leaved Poadveed) PRIMU]L&CEAE Lysimachia nummalaria L.. (Moneywort) &OSACEAE *Crataegus viridis L. (Southern Thorn... Fragaria vi-riniana Duchesne. (Cultivated Strawberry) Potentilla simplex 1uichx. (Common Cinquef oil) *Prunus americans Marsh. (Wild Plum) *Prunus

  5. Investigation into feed utilisation by fore-aged silver carp (Hypophthalmichthys molitrix) using double-marked algae (14C and 51Cr)

    International Nuclear Information System (INIS)

    Wessel, B.; Spittler, P.; Heerkloss, R.

    1982-01-01

    The blue-green alga Microcystis firma and two green algae, Dunaliella viridis and Chlorella vulgaris, were double-marked with 14 C and 51 Cr. The 51 Cr was used as an indicator to measure the assimilation efficiency of fore-aged silver carp for radiocarbon. The assimilation efficiency values obtained were 89.0 +- 5.43% for M. firma, 61.3 +- 15.28% for D. viridis and 91.3 +- 2.22% for C. vulgaris. (author)

  6. Spectral diffusion and electron-phonon coupling of the B800 BChl a molecules in LH2 complexes from three different species of purple bacteria.

    Science.gov (United States)

    Baier, J; Gabrielsen, M; Oellerich, S; Michel, H; van Heel, M; Cogdell, R J; Köhler, J

    2009-11-04

    We have investigated the spectral diffusion and the electron-phonon coupling of B800 bacteriochlorophyll a molecules in the peripheral light-harvesting complex LH2 for three different species of purple bacteria, Rhodobacter sphaeroides, Rhodospirillum molischianum, and Rhodopseudomonas acidophila. We come to the conclusion that B800 binding pockets for Rhodobacter sphaeroides and Rhodopseudomonas acidophila are rather similar with respect to the polarity of the protein environment but that the packaging of the alphabeta-polypeptides seems to be less tight in Rb. sphaeroides with respect to the other two species.

  7. Genetically Modified Bacteria for Fuel Production: Development of Rhodobacteria as a Versatile Platform for Fuels Production

    Energy Technology Data Exchange (ETDEWEB)

    None

    2010-07-01

    Electrofuels Project: Penn State is genetically engineering bacteria called Rhodobacter to use electricity or electrically generated hydrogen to convert carbon dioxide into liquid fuels. Penn State is taking genes from oil-producing algae called Botryococcus braunii and putting them into Rhodobacter to produce hydrocarbon molecules, which closely resemble gasoline. Penn State is developing engineered tanks to support microbial fuel production and determining the most economical way to feed the electricity or hydrogen to the bacteria, including using renewable sources of power like solar energy.

  8. Microbial treatment of aqueous wastes

    International Nuclear Information System (INIS)

    Lee, Kang Suk; Chun, Ki Jung; Kim, Kug Chan; Choi, Yong Ho; Kim, Jin Kyu; Kim, In Gyu; Park, Hyo Koo; Lee, Keun Bae

    1992-01-01

    Uranium accumulated extracellularly on the surface of Rhodobacter capsulata and Rhodospirillum rubrum cells. The rate and extent accumulation were subject to environmental parameter such as pH, temperature, carbon source, trace element and interference by certain cations. Uranium accumulation by the cells was rapid and metabolism was not required for uranium uptake by both organism. Cell-bound uranium reached concentration of 22% (Rhodospirillum rubrum) and 24% (Rhdobacter capsulata)of the dry cell weight, but in the cells grown in the presence of inhibitory concentration of CoCl 2 , cell-bound uranium reached concentration of 27% (Rhodospirillum rubrum) and 29% (Rhodobacter capsulata) of dry cell weight. (Author)

  9. Canopy-forming seaweeds in urchin-dominated systems in eastern Canada: structuring forces or simple prey for keystone grazers?

    Directory of Open Access Journals (Sweden)

    Caitlin Blain

    Full Text Available Models of benthic community dynamics for the extensively studied, shallow rocky ecosystems in eastern Canada emphasize kelp-urchin interactions. These models may bias the perception of factors and processes that structure communities, for they largely overlook the possible contribution of other seaweeds to ecosystem resilience. We examined the persistence of the annual, acidic (H2SO4, brown seaweed Desmarestia viridis in urchin barrens at two sites in Newfoundland (Canada throughout an entire growth season (February to October. We also compared changes in epifaunal assemblages in D. viridis and other conspicuous canopy-forming seaweeds, the non-acidic conspecific Desmarestia aculeata and kelp Agarum clathratum. We show that D. viridis can form large canopies within the 2-to-8 m depth range that represent a transient community state termed "Desmarestia bed". The annual resurgence of Desmarestia beds and continuous occurrence of D. aculeata and A. clathratum, create biological structure for major recruitment pulses in invertebrate and fish assemblages (e.g. from quasi-absent gastropods to >150,000 recruits kg(-1 D. viridis. Many of these pulses phase with temperature-driven mass release of acid to the environment and die-off in D. viridis. We demonstrate experimentally that the chemical makeup of D. viridis and A. clathratum helps retard urchin grazing compared to D. aculeata and the highly consumed kelp Alaria esculenta. In light of our findings and related studies, we propose fundamental changes to the study of community shifts in shallow, rocky ecosystems in eastern Canada. In particular, we advocate the need to regard certain canopy-forming seaweeds as structuring forces interfering with top-down processes, rather than simple prey for keystone grazers. We also propose a novel, empirical model of ecological interactions for D. viridis. Overall, our study underscores the importance of studying organisms together with cross-scale environmental

  10. Individual specialization to non-optimal hosts in a polyphagous marine invertebrate herbivore.

    Directory of Open Access Journals (Sweden)

    Finn A Baumgartner

    Full Text Available Factors determining the degree of dietary generalism versus specialism are central in ecology. Species that are generalists at the population level may in fact be composed of specialized individuals. The optimal diet theory assumes that individuals choose diets that maximize fitness, and individual specialization may occur if individuals' ability to locate, recognize, and handle different food types differ. We investigate if individuals of the marine herbivorous slug Elysia viridis, which co-occur at different densities on several green macroalgal species in the field, are specialized to different algal hosts. Individual slugs were collected from three original algal host species (Cladophora sericea, Cladophora rupestris and Codium fragile in the field, and short-term habitat choice and consumption, as well as long-term growth (proxy for fitness, on four algal diet species (the original algal host species and Chaetomorpha melagonium were studied in laboratory experiments. Nutritional (protein, nitrogen, and carbon content and morphological (dry weight, and cell/utricle volume algal traits were also measured to investigate if they correlated with the growth value of the different algal diets. E. viridis individuals tended to choose and consume algal species that were similar to their original algal host. Long-term growth of E. viridis, however, was mostly independent of original algal host, as all individuals reached a larger size on the non-host C. melagonium. E. viridis growth was positively correlated to algal cell/utricle volume but not to any of the other measured algal traits. Because E. viridis feeds by piercing individual algal cells, the results indicate that slugs may receive more cytoplasm, and thus more energy per unit time, on algal species with large cells/utricles. We conclude that E. viridis individuals are specialized on different hosts, but host choice in natural E. viridis populations is not determined by the energetic value of

  11. Interspecific variation within the genus Asclepias in response to herbivory by a phloem-feeding insect herbivore.

    Science.gov (United States)

    Zehnder, Caralyn B; Hunter, Mark D

    2007-11-01

    Induced plant responses to leaf-chewing insects have been well studied, but considerably less is known about the effects of phloem-feedings insects on induction. In a set of laboratory experiments, we examined density-dependent induction by the milkweed-oleander aphid, Aphis nerii, of putative defenses in four milkweed species (Asclepias incarnata, Asclepias syriaca, Asclepias tuberosa, and Asclepias viridis). We hypothesized that high aphid density would lead to increased cardenolide expression in species with low constitutive levels of cardenolides (e.g., A. tuberosa), but that there would be no induction in high constitutive cardenolide species (e.g., A. viridis). Based on previous studies, we did not expect cardenolide induction in A. incarnata. Contrary to our predictions, we observed feeding-induced declines of cardenolide concentrations in A. viridis. Cardenolide concentrations did not respond to aphid feeding in the other three milkweed species. Aphids also caused reductions in biomass accumulation by two of four Asclepias species, A. viridis and A. incarnata. High aphid density led to a decrease in A. viridis foliar nitrogen concentration. However, aphids had no effect on the defensive chemistry, growth, or nutritional quality of either A. syriaca or A. tuberosa. Our results highlight that congeneric plant species may respond differently to the same levels of herbivore damage.

  12. Hemifluorinated maltose-neopentyl glycol (HF-MNG) amphiphiles for membrane protein stabilisation.

    Science.gov (United States)

    Cho, Kyung Ho; Byrne, Bernadette; Chae, Pil Seok

    2013-03-04

    SOAP OPERA: Fluorinated amphiphile F4-MNG confers greater stability on Rhodobacter capsulatus superassembly relative to conventional detergents and nonfluorinated MNGs. Such amphiphiles are attractive as tools for membrane science because of their ease of preparation and structure variation. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Continuous Cultivation of Photosynthetic Bacteria for Fatty Acids Production

    DEFF Research Database (Denmark)

    Kim, Dong-Hoon; Lee, Ji-Hye; Hwang, Yuhoon

    2013-01-01

    In the present work, we introduced a novel approach for microbial fatty acids (FA) production. Photosynthetic bacteria, Rhodobacter sphaeroides KD131, were cultivated in a continuous-flow, stirred-tank reactor (CFSTR) at various substrate (lactate) concentrations.At hydraulic retention time (HRT)....... sphaeroides was around 35% of dry cell weight, mainly composed of vaccenic acid (C18:1, omega-7)....

  14. Long-Range Energy Propagation in Nanometer Arrays of Light Harvesting Antenna Complexes

    NARCIS (Netherlands)

    Escalantet, Maryana; Escalante Marun, M.; Lenferink, Aufrid T.M.; Zhao, Yiping; Tas, Niels Roelof; Huskens, Jurriaan; Hunter, C. Neil; Subramaniam, Vinod; Otto, Cornelis

    2010-01-01

    Here we report the first observation of long-range transport of excitation energy within a biomimetic molecular nanoarray constructed from LH2 antenna complexes from Rhodobacter sphaeroides. Fluorescence microscopy of the emission of light after local excitation with a diffraction-limited light beam

  15. NCBI nr-aa BLAST: CBRC-ATHA-01-0056 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-ATHA-01-0056 ref|YP_354669.1| ABC nitrate/sulfonate/bicarbonate transporter fa...mily, periplasmic substrate-binding protein [Rhodobacter sphaeroides 2.4.1] gb|ABA80768.1| ABC nitrate/sulfonate/bicarbonate

  16. Photocycle of the flavin-binding photoreceptor AppA, a bacterial transcriptional antirepressor of photosynthesis genes

    NARCIS (Netherlands)

    Gauden, M.L.; Yeremenko, S.; Laan, W.; van Stokkum, I.H.M.; Ihalainen, J.A.; van Grondelle, R.; Hellingwerf, K.J.; Kennis, J.T.M.

    2005-01-01

    The flavoprotein AppA from Rhodobacter sphaeroides contains an N-terminal domain belonging to a new class of photoreceptors designated BLUF domains. AppA was shown to control photosynthesis gene expression in response to blue light and oxygen tension. We have investigated the photocycle of the AppA

  17. GenBank blastx search result: AK061856 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK061856 001-040-G03 AF018073.1 Rhodobacter sphaeroides operon regulator (smoC), periplasmic sorbitol...-binding protein (smoE), sorbitol/mannitol transport inner membrane protein (smoF), sorbitol.../mannitol transport inner membrane protein (smoG), sorbitol/mannitol transport ATP-binding transport protein (smoK), sorbitol

  18. The lateral distance between a proton pump and ATP synthase determines the ATP-synthesis rate

    Czech Academy of Sciences Publication Activity Database

    Sjöholm, C.; Bergstrand, J.; Nilsson, T.; Šachl, Radek; von Ballmoos, Ch.; Widengren, J.; Brzezinski, P.

    2017-01-01

    Roč. 7, č. 1 (2017), č. článku 2926. ISSN 2045-2322 Institutional support: RVO:61388955 Keywords : biological energy -conversion * cytochrome-c-oxidase * membrane-surface * rhodobacter-sphaeroides Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 4.259, year: 2016

  19. Functional LH1 antenna complexes influence electron transfer in bacterial photosynthetic reaction centers

    NARCIS (Netherlands)

    Visschers, R.W.; Vulto, S.I.E.; Jones, M.R.; van Grondelle, R.; Kraayenhof, R.

    1999-01-01

    The effect of the light harvesting 1 (LH1) antenna complex on the driving force for light-driven electron transfer in the Rhodobacter sphaeroides reaction center has been examined. Equilibrium redox titrations show that the presence of the LH1 antenna complex influences the free energy change for

  20. Functional LH1 antenna complexes influence electron transfer in bacterial photosynthetic reaction centers.

    NARCIS (Netherlands)

    Visschers, R.W.; Vulto, S.I.E.; Jones, M.R.; van Grondelle, R.; Kraayenhof, R.

    1999-01-01

    The effect of the light harvesting 1 (LH1) antenna complex on the driving force for light-driven electron transfer in the Rhodobacter sphaeroides reaction center has been examined. Equilibrium redox titrations show that the presence of the LH1 antenna complex influences the free energy change for

  1. Investigation of the effects of different carotenoids on the absorption and CD signals of light harvesting 1 complexes

    NARCIS (Netherlands)

    Georgakopoulou, S.; van der Zwan, G.; Olsen, J.D.; Hunter, C.N.; Niederman, R.A.; van Grondelle, R.

    2006-01-01

    Absorption and circular dichroism (CD) spectra of light-harvesting (LH)1 complexes from the purple bacteria Rhodobacter (Rba.) sphaeroides and Rhodospirillum (Rsp.) rubrum are presented. The complexes exhibit very low intensity, highly nonconservative, near-infrared (NIR) CD spectra. Absorption and

  2. Diverse Arrangement of Photosynthetic Gene Clusters in Aerobic Anoxygenic Phototrophic Bacteria

    Czech Academy of Sciences Publication Activity Database

    Zheng, Q.; Zhang, R.; Koblížek, Michal; Boldareva, Ekaterina; Yurkov, V.; Shi, Y.

    2011-01-01

    Roč. 6, č. 9 (2011), s. 1-7 E-ISSN 1932-6203 R&D Projects: GA ČR GAP501/10/0221 Institutional research plan: CEZ:AV0Z50200510 Keywords : RHODOBACTER-CAPSULATUS * CITROMICROBIUM-BATHYOMARINUM * REACTION CENTERS Subject RIV: EE - Microbiology, Virology Impact factor: 4.092, year: 2011

  3. Severe Toxic Skin Reaction Caused by a Common Anemone and Identification of the Culprit Organism.

    Science.gov (United States)

    Tezcan, Özgür Deniz; Gözer, Özgür

    2015-01-01

    In a marine envenomation, identification of the culprit organism can be difficult. In this case report, we present our method to identify snakelocks anemone (Anemonia viridis or formerly Anemonia sulcata) as the culprit of a severe toxic skin reaction. A. viridis is one of the most common anemones of the Mediterranean Sea and the North Atlantic Ocean. It lives at a depth of up to 10 m. It is a member of the phylum Cnidaria, which includes jellyfish, anemones, hydroids, and corals. They have toxic organelles called cnidocysts that have the capacity to inject venom with microscopic harpoon-like structures. The cnidocysts of A. viridis may cause toxic and allergic reactions, and although its venom is one of the most studied cnidarian venoms, detailed case reports are rare. © 2015 International Society of Travel Medicine.

  4. [Spatial distribution pattern and allometric growth of three common species on moving sand dunes in Horqin Sandy Land, China].

    Science.gov (United States)

    Jia, Mei-yu; Li, Xue-hua; Oh, Choong-hyeon; Park, Hong-chul; Miao, Chun-ping; Han, Xu

    2015-10-01

    Research on fine scale pattern and characteristics of allometric growth could contribute to better understanding plants' adaptation in moving sandy dunes. The abundance, height and biomass of 3 species Agriophilum aquarrosum, Corispermum candelabrum and Setaria viridis in twenty-eight 1 m x 1 m quadrats of Horqin Sandy Land were identified, mapped and described. The nearest neighbor method and O-ring O(r) function analysis were applied to analyze the spatial patterns. The results showed that the individual spatial pattern was mainly aggregated in 1 m x 1 m quadrat at community level but mainly random at population level. At 0-50 cm individual distance scale, both intraspecific and interspecific relationship were facilitation and aggregated distribution occurred at some scales and varied with increasing plant abundance in 1 m x 1 m quadrat. In 0-40 cm, the aggregated distribution of S. viridis and A. aquarrosum increased obviously; in 10-20 cm, both intraspecific and interspecific aggregation increased; in 10-30 cm, the occurrence possibility of positive correlations between S. viridis and A. aquarrosum, S. viridis and C. candelabrum all increased; in 40-50 cm, the possibility of positive correlations between A. squarrosum and S. viridis, A. squarrosum and C. candelabrum all increased. Research on the three species components indicated that the growth rate of above-ground was faster than that of underground. S. viridis had the highest ratio of under-ground biomass to above-ground biomass but its nutritional organs' biomass ratio was medium. C. candelabrum allocated more biomass to propagative organs and stem, but A. squarrosum allocated more biomass to nutritional organs. Based on the spatial distribution and allometric characteristics, the three common species in moving sand dunes preferred r strategy in their life history.

  5. Micropropagation of Lavandula spp.

    Science.gov (United States)

    Gonçalves, Sandra; Romano, Anabela

    2013-01-01

    Lavandula species are some of the most popular ornamental and medicinal plants with great economic values. These species are vegetative propagated by stem cuttings. However, the poor rooting ability and vulnerability of plantlets to contamination are major limiting factors for propagation. In vitro culture methods are suitable to overcome these limitations. This chapter describes protocols for in vitro propagation of Lavandula viridis L'Hér and Lavandula vera DC. Nodal shoot proliferation of L. viridis and plant regeneration from leaf-derived callus of L. vera by an "open culture system" are highlighted.

  6. Compilation of 1984 Annual Reports of the Navy ELF (Extremely Low Frequency) Communications System Ecological Monitoring Program. Volume 1. TABS A-E.

    Science.gov (United States)

    1985-06-01

    parviforus 4.0 Trientalis borealis --- 7.9 Vaccinium membranaceum 4.2 3.3 Viburnum acerfolium --- 11.1 Waldsteinia fragaria --- 1.6 I ". r h m li mm...Templeton) Pseudachorutes spp. complex Isotoridae: Isotoma (Tesoria) nigrifrons Folsom 1. (Isotona) viridis Bourlet * FEntomobryidae: Tomocerus...67.1 66.4 66.9 71.9 Z 0. hexfasciata 16.4 13.2 17.6 14.2 N Isotomidae 50 36 84 67 % I. niarifrons 50.0 55.6 57.1 76.1 %I. viridis 50.0 44.4 42.9 23.9 N

  7. Interferência de caruru-de-mancha sobre características de crescimento e produção da beterraba

    OpenAIRE

    Marcolini,L.W.; Carvalho,L.B.; Cruz,M.B.; Alves,P.L.C.A.; Cecílio Filho,A.B.

    2010-01-01

    A beterraba (Beta vulgaris), importante hortaliça cultivada no Brasil, é muito suscetível à interferência de plantas daninhas, sendo Amaranthus viridis uma das principais espécies encontradas em áreas de horticultura. O objetivo deste trabalho foi estudar a resposta da beterraba à competição com diferentes densidades de A. viridis, por meio da avaliação de características de crescimento e produção da cultura. Um experimento em caixas, com área útil de 0,25 m², foi conduzido em Jaboticabal-SP,...

  8. Interferência de caruru-de-mancha sobre características de crescimento e produção da beterraba Slender amaranth interference in table beet growth and production characteristics

    Directory of Open Access Journals (Sweden)

    L.W. Marcolini

    2010-01-01

    Full Text Available A beterraba (Beta vulgaris, importante hortaliça cultivada no Brasil, é muito suscetível à interferência de plantas daninhas, sendo Amaranthus viridis uma das principais espécies encontradas em áreas de horticultura. O objetivo deste trabalho foi estudar a resposta da beterraba à competição com diferentes densidades de A. viridis, por meio da avaliação de características de crescimento e produção da cultura. Um experimento em caixas, com área útil de 0,25 m², foi conduzido em Jaboticabal-SP, Brasil, mantendo-se constante oito plantas por caixa de beterraba em convivência com 0, 1, 2, 3, 4 e 6 plantas por caixa de A. viridis. A cultura da beterraba foi muito suscetível à interferência imposta por plantas de A. viridis, tendo sua área foliar, número de folhas, massa seca de folhas, diâmetro médio da raiz e massa fresca de raízes significativamente reduzidos mesmo em baixas densidades populacionais da planta daninha; a massa fresca de raízes foi a mais sensível à interferência.Table beet (Beta vulgaris, an important vegetable cultivated in Brazil, is very susceptible to weed interference, with Amaranthus viridis being one of the main species found in horticultural areas. The objective of this research was to study the response of table beet to competition at different densities of A. viridis, based on evaluation of crop growth and production characteristics. An experiment was carried out in 0.25 m² pots in Jaboticabal-SP, Brazil, with 8 table beet plants per pot kept in constant coexistence with 0, 1, 2, 3, 4 and 6 plants per pot of A. viridis. The table beet crop was very susceptible to interference of A. viridis, with its leaf area, number of leaves, leaf dry mass, root mean diameter and root fresh mass being significantly reduced even under low weed densities, with root fresh mass being the most sensitive to interference.

  9. Observations on the activity patterns of the lesser yellow house bat ...

    African Journals Online (AJOL)

    lesser yellow house bat, Scotophilus viridis. F.P.D. Cotterill c/o Department of Zoology, University of Cape Town,. Cape Town. S.R. Giddings·. Department of Zoology, University of Pretoria, Pretoria,. 0002 Republic of South Africa. Received 10 June 1986; accepted 23 July 1986. The activity pattems of the lesser yellow ...

  10. Dicty_cDB: Contig-U08145-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available . 50 1e-04 AF021822_1( AF021822 |pid:none) Scaptodrosophila lebanonensis supe... ...emonia viridis copper/zinc super... 49 6e-04 AF021824_1( AF021824 |pid:none) Hirtodrosophila pictiventris su

  11. The presence of species of Pseudochironomus Malloch 1915 (Diptera: Chironomidae) in watercourses of Chaco Serrano Ecoregion (Argentina, South America).

    Science.gov (United States)

    Paggi, Analía C; Rodriguez Garay, Gretel N

    2015-05-15

    Male imagos of Pseudochironomus viridis (Kieffer) are redescribed, the immature stages are described and figured for the first time. During this study, larva and pupal exuviae associated to P. richardsoni (Malloch) were recorded for the first time for South America. The specimens were collected from a stream and a river in the Pampasic Hills System in the Chaco Serrano ecoregion of Argentina.

  12. Effects of sand burial on the survival and physiology of three ...

    African Journals Online (AJOL)

    Corispermum macrocarpum, Setaria viridis and Agriophyllum squarrosum are dominant psammophytes with strong environmental adaptability in Horqin Sandy Land, a typical agro-pastoral ecotone with frequent and intense sand activity in Northern China. We studied the survival rates, activity of antioxidant enzyme ...

  13. Monterey Peninsula Water Supply Project. Supplemental Draft Environmental Impact Report/Statement II. Appendices

    Science.gov (United States)

    1993-02-01

    ROSACEAE Acaena californica: C-S, CPI Adenostoma fasciculctmm: CH-, CS, C-L Aichemilla arvensis: CP Fragaria vesca ssp. cabjfomica: NP, LO, M-LI Hetermeles...Thamnophis elegans * Western Aquatic Garter Snake T. couchi * Common Garter Snake T. sinalis * Western Rattlesnake Crotalus viridis TOTAL 22 8 3 3 BIRDS

  14. Environmental Impact Study of the Northern Section of the Upper Mississippi River. Pool 1.

    Science.gov (United States)

    1973-11-01

    grass P Poa pratensis Blue grass Setaria viridis Green foxtail P P P P D Setaria sp. Bristly foxtail P Spartina pectinata Prairie cord grass P...Agrimonia pubescens Cocklebur Alchemilla sp. Lady’s mantle P Fragaria vesca Wild strawberry Oewn canadense White avens Gewn laciniatun Avens Geum

  15. Environmental Impact Analysis Process. Environmental Impact Statement. Supersonic Flight Operations in the Reserve Military Operations Area, Holloman AFB, New Mexico

    Science.gov (United States)

    1983-09-01

    tailed Rattlesnake Crotalus molossus Western Rattlesnake Crotalus viridis CAUTION Most snake bites occur to people who are trying to kill or catch snakes...Strawberry Fragaria bracteata Yarrow Achillea lanulosa Yellow Sweetclover Melilotus indicus IX L-2 List of Preparers Jim Battis; AFGL/LWH, Ha’-com

  16. Environmental Impact Study of the Northern Section of the Upper Mississippi River, St. Croix River Pool.

    Science.gov (United States)

    1973-11-01

    Poa palustris Fowl meadow-grass P Poa pratensis Blue grass Setaria viridis Green foxtail P P P P D Setaria sp. Bristly foxtail P Spartina pectinata...Juneberry) Crataegus spp. (Thorn-Apple) Fragaria vesca (Wild Strawberry) Geum canadense (White Avens) Geum laciniatum (Avens) Geum triflorum (Three

  17. Environmental Impact Study of the Northern Section of the Upper Mississippi River. Pool 2.

    Science.gov (United States)

    1973-11-01

    Setaria viridis Green foxtail P P P P D Setaria sp. Bristly foxtail P Spartina pectinata Prairie cord grass P Unidentified sp. D P P 1YDROCHARITACEAE...americanus New Jersey tea ROSACEAE Agrimonia pubescens Cocklebur Alchemilla sp. Lady’s mantle P Fragaria oesca Wild strawberry Cewn canadense White avens

  18. Environmental Impact Study of The Northern Section of the Upper Mississippi River, Minnesota River Pool.

    Science.gov (United States)

    1973-11-01

    Setaria viridis I Green foxtail P P P P D Setaria sp. I Bristly foxtail P Spartina pectinata Prairie cord grass P Unidentified sp. D P P...Thalictrn sp. Meadow-rue P P RPAMNACEAE Ceanothus omericanus New Jersey tea ROSACEAE Agrimonia pubescens Cocklebur AZchemilla sp. Lady’s mantle P Fragaria

  19. Description and key to the fifth-instars of some Cicadas (Hemiptera: Cicadidae) associated with coffee plants in Brazil.

    Science.gov (United States)

    Maccagnan, D H B; Martinelli, N M

    2011-01-01

    Fifth-instars of the cicada species Dorisiana drewseni (Stål), Dorisiana viridis (Olivier), Fidicina mannifera (Fabricius), Fidicinoides pronoe (Walker) and Carineta fasciculata (Germar) are described and illustrated. Moreover, a key to the nymphs of these species along with Quesada gigas (Olivier) is also provided.

  20. The stable microbiome of inter and sub-tidal anemone species under increasing pCO2.

    Science.gov (United States)

    Muller, Erinn M; Fine, Maoz; Ritchie, Kim B

    2016-11-23

    Increasing levels of pCO 2 within the oceans will select for resistant organisms such as anemones, which may thrive under ocean acidification conditions. However, increasing pCO 2 may alter the bacterial community of marine organisms, significantly affecting the health status of the host. A pH gradient associated with a natural volcanic vent system within Levante Bay, Vulcano Island, Italy, was used to test the effects of ocean acidification on the bacterial community of two anemone species in situ, Anemonia viridis and Actinia equina using 16 S rDNA pyrosequencing. Results showed the bacterial community of the two anemone species differed significantly from each other primarily because of differences in the Gammaproteobacteria and Epsilonproteobacteria abundances. The bacterial communities did not differ within species among sites with decreasing pH except for A. viridis at the vent site (pH = 6.05). In addition to low pH, the vent site contains trace metals and sulfide that may have influenced the bacteria community of A. viridis. The stability of the bacterial community from pH 8.1 to pH 7.4, coupled with previous experiments showing the lack of, or beneficial changes within anemones living under low pH conditions indicates that A. viridis and A. equina will be winners under future ocean acidification scenarios.

  1. Morphological and molecular characterization of lymnaeid snails and their potential role in transmission of Fasciola spp. in Vietnam.

    Science.gov (United States)

    Dung, Bui Thi; Doanh, Pham Ngoc; The, Dang Tat; Loan, Ho Thi; Losson, Bertrand; Caron, Yannick

    2013-12-01

    Freshwater snails of the family Lymnaeidae play an important role in the transmission of fascioliasis worldwide. In Vietnam, 2 common lymnaeid species, Lymnaea swinhoei and Lymnaea viridis, can be recognized on the basis of morphology, and a third species, Lymnaea sp., is known to exist. Recent studies have raised controversy about their role in transmission of Fasciola spp. because of confusion in identification of the snail hosts. The aim of this study is, therefore, to clarify the identities of lymnaeid snails in Vietnam by a combination of morphological and molecular approaches. The molecular analyses using the second internal transcribed spacer (ITS2) of the nuclear ribosomal DNA clearly showed that lymnaeids in Vietnam include 3 species, Austropeplea viridis (morphologically identified as L. viridis), Radix auricularia (morphologically identified as L. swinhoei) and Radix rubiginosa (morphologically identified as Lymnaea sp.). R. rubiginosa is a new record for Vietnam. Among them, only A. viridis was found to be infected with Fasciola spp. These results provide a new insight into lymnaeid snails in Vietnam. Identification of lymnaeid snails in Vietnam and their role in the liver fluke transmission should be further investigated.

  2. Egg numbers and fecundity traits in nine species of Mantella poison ...

    African Journals Online (AJOL)

    The body size and number of eggs in dissected females were analysed in nine species of the Malagasy frog genus Mantella basing upon preserved specimens. These species were distinguished in terms of habitat and grouped as 'grassland species' (included M. betsileo, M. expectata, M. viridis), and 'rainforest species' ...

  3. The status of Vespertilio borbonicus E. Geoffroy, 1803 (Chiroptera: Vespertilionidae)

    NARCIS (Netherlands)

    Hill, J.E.

    1980-01-01

    The taxonomic history of Scotophilus borbonicus (E. Geoffroy, 1803) from Réunion Island is reviewed and summarised, with the designation of a lectotype. The insular form that it represents is considered conspecific with the small Scotophilus viridis (Peters, 1852) of southern Africa. As a result,

  4. Browse Title Index

    African Journals Online (AJOL)

    Vol 7, No 17 (2008), Anti-emetic activity of Grewia lasiodiscus root extract and fractions, Abstract PDF. AY Tijani, SE Okhale, FE Oga, SZ Tags, OA Salawu, BA Chindo. Vol 13, No 27 (2014), Antifouling potential of seaweed, sponge and cashew nut oil extracts against biofilm bacteria and green mussel Perna viridis from ...

  5. Setaria faberi Herrm. (Chinese naaldaar) in Nederland over ’t hoofd gezien

    NARCIS (Netherlands)

    Dirkse, G.M.; Reijerse, A.I.; Abbink-Meijerink, C.G.

    2001-01-01

    Setaria faberi was only very recently recognized as a weed in cornfields in the Netherlands. The first herbarium collection dates back to 1925. The authors present a new identification key for the Dutch Setaria species, illustrated with SEM images of the spikelets of S. faberi, S. viridis and S.

  6. Conditional Reduction of Predation Risk Associated with a Facultative Symbiont in an Insect.

    Directory of Open Access Journals (Sweden)

    Sarah Polin

    Full Text Available Symbionts are widespread among eukaryotes and their impacts on the ecology and evolution of their hosts are meaningful. Most insects harbour obligate and facultative symbiotic bacteria that can influence their phenotype. In the pea aphid Acyrthosiphon pisum, an astounding symbiotic-mediated phenotype has been recently observed: when infected with the symbiotic bacteria Rickettsiella viridis, young red aphid larvae become greener at adulthood and even darker green when co-infected with Rickettsiella viridis and Hamiltonella defensa. As body colour affects the susceptibility towards natural enemies in aphids, the influence of the colour change due to these facultative symbionts on the host survival in presence of predators was tested. Our results suggested that the Rickettsiella viridis infection may impact positively host survival by reducing predation risk. Due to results from uninfected aphids (i.e., more green ones attacked, the main assumption is that this symbiotic infection would deter the predatory ladybird feeding by reducing the profitability of their hosts rather than decreasing host detection through body colour change. Aphids co-infected with Rickettsiella viridis and Hamiltonella defensa were, however, more exposed to predation suggesting an ecological cost associated with multiple infections. The underlying mechanisms and ecological consequences of these symbiotic effects are discussed.

  7. [Peculiarities of growth of the monocellular green algae culture after the influence of electromagnetic field in deuterated water-containing media].

    Science.gov (United States)

    Semenov, K T; Aslanian, R R

    2013-01-01

    Exposing the inoculum of monocellular green algae Dunalialla tertiolecta and Tetraselmis viridis to 50 Hz electromagnetic field for several hours resulted in a reduced growth rate in both cultures. It was ascertained that heavy water inhibited growth of algae Dunaliella tertiolecta. The light water activated growth of the culture in the exponential phase only.

  8. Visualizing a protein quake with time-resolved X-ray scattering at a free-electron laser

    DEFF Research Database (Denmark)

    Arnlund, David; Johansson, Linda C.; Wickstrand, Cecilia

    2014-01-01

    We describe a method to measure ultrafast protein structural changes using time-resolved wide-angle X-ray scattering at an X-ray free-electron laser. We demonstrated this approach using multiphoton excitation of the Blastochloris viridis photosynthetic reaction center, observing an ultrafast glob...

  9. 78 FR 26540 - Importation of Jackfruit, Pineapple, and Starfruit From Malaysia Into the Continental United States

    Science.gov (United States)

    2013-05-07

    ... insect pests, inspected, and imported in commercial consignments. There would also be additional.... viridis, green scale. Darna trima, a nettle caterpillar. D. neobrevipes Beardsley, gray pineapple mealybug... phytopathogenic fungus. Melanitis leda, evening brown butterfly. Parasa lepida, blue-striped nettle grub. P. minor...

  10. Allelopathy in pigweed (a review)

    OpenAIRE

    Pedro Luis da Costa Aguiar Alves; Leonardo Bianco de Carvalho; Marcelo Claro de Souza; Paulo Roberto Fidelis Giancotti

    2011-01-01

    Amaranthus spp. are plants with proven allelopathic potential. The release of allelochemicals from Amaranthus spp. in the environment can influence seed germination, photosynthesis rate, reduce growth and, consequently, the productivity of various plant species. Among the species with allelopathic potential are Amaranthus blitoides, Amaranthus gracilis, Amaranthus hybridus, Amaranthus palmeri, Amaranthus retroflexus, Amaranthus spinosus and Amaranthus viridis, with A. retroflexus being the mo...

  11. Survival and bioturbation effects of common marine macrofauna in coastal soils newly flooded with seawater

    DEFF Research Database (Denmark)

    Valdemarsen, Thomas Bruun; Quintana, Cintia Organo; Thorsen, Sandra Walløe

    Low-lying coastal soils are at risk of being permanently flooded due to global sea level rise, but how will these areas develop as habitat for marine species? We conducted an experiment to evaluate the habitat quality of flooded soils for common marine polychaetes (Marenzelleria viridis, Nereis d...

  12. A note on scavenging behaviour of adult Hermann’s tortoise (Testudo hermanni

    Directory of Open Access Journals (Sweden)

    Nikolić, M.

    2016-09-01

    Full Text Available Report of the first observation of scavenging behaviour in the population of Testudo hermanni boettgeri that has been monitored for six years in the village Kunovica near the city of Niš in Serbia. On 31 May 2015 at 10:18 a.m., the adult tortoise was observed while eating a dead European green lizard (Lacerta viridis.

  13. Molecular discrimination of Perna (Mollusca: Bivalvia) species using the polymerase chain reaction and species-specific mitochondrial primers

    DEFF Research Database (Denmark)

    Blair, D.; Waycott, M.; Byrne, L.

    2006-01-01

    This work was prompted by the need to be able to identify the invasive mussel species, Perna viridis, in tropical Australian seas using techniques that do not rely solely on morphology. DNA-based molecular methods utilizing a polymerase chain reaction (PCR) approach were developed to distinguish...

  14. Adapt, move or die - how will tropical coral reef fishes cope with ocean warming?

    DEFF Research Database (Denmark)

    Habary, Adam; Johansen, Jacob L.; Nay, Tiffany J.

    2017-01-01

    poleward, away from ocean warming hotspots where temperatures 2-3 °C above long-term annual means can compromise critical physiological processes. We examined the capacity of a model species - a thermally sensitive coral reef fish, Chromis viridis (Pomacentridae) - to use preference behaviour to regulate...

  15. Biosynthesis of Chlorophyll a in a Purple Bacterial Phototroph and Assembly into a Plant Chlorophyll-Protein Complex.

    Science.gov (United States)

    Hitchcock, Andrew; Jackson, Philip J; Chidgey, Jack W; Dickman, Mark J; Hunter, C Neil; Canniffe, Daniel P

    2016-09-16

    Improvements to photosynthetic efficiency could be achieved by manipulating pigment biosynthetic pathways of photosynthetic organisms in order to increase the spectral coverage for light absorption. The development of organisms that can produce both bacteriochlorophylls and chlorophylls is one way to achieve this aim, and accordingly we have engineered the bacteriochlorophyll-utilizing anoxygenic phototroph Rhodobacter sphaeroides to make chlorophyll a. Bacteriochlorophyll and chlorophyll share a common biosynthetic pathway up to the precursor chlorophyllide. Deletion of genes responsible for the bacteriochlorophyll-specific modifications of chlorophyllide and replacement of the native bacteriochlorophyll synthase with a cyanobacterial chlorophyll synthase resulted in the production of chlorophyll a. This pigment could be assembled in vivo into the plant water-soluble chlorophyll protein, heterologously produced in Rhodobacter sphaeroides, which represents a proof-of-principle for the engineering of novel antenna complexes that enhance the spectral range of photosynthesis.

  16. Biotic interactions in the face of climate change: a comparison of three modelling approaches.

    Directory of Open Access Journals (Sweden)

    Anja Jaeschke

    Full Text Available Climate change is expected to alter biotic interactions, and may lead to temporal and spatial mismatches of interacting species. Although the importance of interactions for climate change risk assessments is increasingly acknowledged in observational and experimental studies, biotic interactions are still rarely incorporated in species distribution models. We assessed the potential impacts of climate change on the obligate interaction between Aeshna viridis and its egg-laying plant Stratiotes aloides in Europe, based on an ensemble modelling technique. We compared three different approaches for incorporating biotic interactions in distribution models: (1 We separately modelled each species based on climatic information, and intersected the future range overlap ('overlap approach'. (2 We modelled the potential future distribution of A. viridis with the projected occurrence probability of S. aloides as further predictor in addition to climate ('explanatory variable approach'. (3 We calibrated the model of A. viridis in the current range of S. aloides and multiplied the future occurrence probabilities of both species ('reference area approach'. Subsequently, all approaches were compared to a single species model of A. viridis without interactions. All approaches projected a range expansion for A. viridis. Model performance on test data and amount of range gain differed depending on the biotic interaction approach. All interaction approaches yielded lower range gains (up to 667% lower than the model without interaction. Regarding the contribution of algorithm and approach to the overall uncertainty, the main part of explained variation stems from the modelling algorithm, and only a small part is attributed to the modelling approach. The comparison of the no-interaction model with the three interaction approaches emphasizes the importance of including obligate biotic interactions in projective species distribution modelling. We recommend the use of

  17. Membrane Curvature Induced by Aggregates of LH2s and Monomeric LH1s

    OpenAIRE

    Chandler, Danielle E.; Gumbart, James; Stack, John D.; Chipot, Christophe; Schulten, Klaus

    2009-01-01

    The photosynthetic apparatus of purple bacteria is contained within organelles called chromatophores, which form as extensions of the cytoplasmic membrane. The shape of these chromatophores can be spherical (as in Rhodobacter sphaeroides), lamellar (as in Rhodopseudomonas acidophila and Phaeospirillum molischianum), or tubular (as in certain Rb. sphaeroides mutants). Chromatophore shape is thought to be influenced by the integral membrane proteins Light Harvesting Complexes I and II (LH1 and ...

  18. Visualizing tributyltin (TBT) in bacterial aggregates by specific rhodamine-based fluorescent probes.

    Science.gov (United States)

    Jin, Xilang; Hao, Likai; She, Mengyao; Obst, Martin; Kappler, Andreas; Yin, Bing; Liu, Ping; Li, Jianli; Wang, Lanying; Shi, Zhen

    2015-01-01

    Here we present the first examples of fluorescent and colorimetric probes for microscopic TBT imaging. The fluorescent probes are highly selective and sensitive to TBT and have successfully been applied for imaging of TBT in bacterial Rhodobacter ferrooxidans sp. strain SW2 cell-EPS-mineral aggregates and in cell suspensions of the marine cyanobacterium Synechococcus PCC 7002 by using confocal laser scanning microscopy. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. The microorganisms as a renewable source of ecological clean fuel

    International Nuclear Information System (INIS)

    Shalygo, N.V.; Mel'nikov, S.S.; Manankina, E.E.; Budakova, E.A.; Kolyago, V.M.

    2006-01-01

    Five families of microorganisms (Bacillaceae, Rhodospirillaceae, Cyanophyceae, Chlorophyceae and Euglenophyceae) as hydrogen producers were tested and the conditions that are necessary for hydrogen photoproduction were investigated. It was shown, that the most effective producers of hydrogen were Rhodobacter spheroides, Clostridium sp.; Euglena gracilis var. bacillaris and Chlamydomonas reinhardtii. Addition of glucose, iron and vanadium salts resulted in the increase of hydrogen production. Polycultures consisted of two or three microorganisms were more effective hydrogen producers compared to separate monocultures. (authors)

  20. Microbiological Hydrogen Production by Anaerobic Fermentation and Photosynthetic Process

    International Nuclear Information System (INIS)

    Asada, Y.; Ohsawa, M.; Nagai, Y.; Fukatsu, M.; Ishimi, K.; Ichi-ishi, S.

    2009-01-01

    Hydrogen gas is a clean and renewable energy carrier. Microbiological hydrogen production from glucose or starch by combination used of an anaerobic fermenter and a photosynthetic bacterium, Rhodobacter spheroides RV was studied. In 1984, the co-culture of Clostridium butyricum and RV strain to convert glucose to hydrogen was demonstrated by Miyake et al. Recently, we studied anaerobic fermentation of starch by a thermophilic archaea. (Author)

  1. Conformational regulation of charge recombination reactions in a photosynthetic bacterial reaction center

    DEFF Research Database (Denmark)

    Katona, Gergely; Snijder, Arjan; Gourdon, Pontus Emanuel

    2005-01-01

    In bright light the photosynthetic reaction center (RC) of Rhodobacter sphaeroides stabilizes the P(+)(870).Q(-)(A) charge-separated state and thereby minimizes the potentially harmful effects of light saturation. Using X-ray diffraction we report a conformational change that occurs within the cy...... the cytoplasmic domain of this RC in response to prolonged illumination with bright light. Our observations suggest a novel structural mechanism for the regulation of electron transfer reactions in photosynthesis....

  2. GenBank blastx search result: AK241729 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241729 J065199L10 AF018073.1 AF018073 Rhodobacter sphaeroides operon regulator (smoC), periplasmic sorbito...l-binding protein (smoE), sorbitol/mannitol transport inner membrane protein (smoF), sorbitol.../mannitol transport inner membrane protein (smoG), sorbitol/mannitol transport ATP-binding transport protein (smoK), sorbit...ol dehydrogenase (smoS), mannitol dehydrogenase (mtlK),

  3. GenBank blastx search result: AK240874 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK240874 J065025K09 AF018073.1 AF018073 Rhodobacter sphaeroides operon regulator (smoC), periplasmic sorbito...l-binding protein (smoE), sorbitol/mannitol transport inner membrane protein (smoF), sorbitol.../mannitol transport inner membrane protein (smoG), sorbitol/mannitol transport ATP-binding transport protein (smoK), sorbit...ol dehydrogenase (smoS), mannitol dehydrogenase (mtlK),

  4. GenBank blastx search result: AK243680 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243680 J100090I20 AF018073.1 AF018073 Rhodobacter sphaeroides operon regulator (smoC), periplasmic sorbito...l-binding protein (smoE), sorbitol/mannitol transport inner membrane protein (smoF), sorbitol.../mannitol transport inner membrane protein (smoG), sorbitol/mannitol transport ATP-binding transport protein (smoK), sorbit...ol dehydrogenase (smoS), mannitol dehydrogenase (mtlK),

  5. 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

  6. Microbial production of hydrogen from starch-manufacturing wastes

    Energy Technology Data Exchange (ETDEWEB)

    Yokoi, H.; Maki, R.; Hirose, J.; Hayashi, S. [Miyazaki Univ. (Japan). Dept. of Applied Chemistry

    2002-05-01

    Effective hydrogen production from starch-manufacturing wastes by microorganisms was investigated. Continuous hydrogen production in high yield of 2.7 mol H{sub 2} mol{sup -1} glucose was attained by a mixed culture of Clostridium butyricum and Enterobacter aerogenes HO-39 in the starch waste medium consisting of sweet potato starch residue as a carbon source and corn steep liquor as a nitrogen source in a repeated batch culture. Rhodobacter sp. M-19 could produce hydrogen from the supernatant of the culture broth obtained in the repeated batch culture of C. butyricum and E. aerogenes HO-39. Hydrogen yield of 4.5 mol H{sub 2} mol{sup -1} glucose was obtained by culturing Rhodobacter sp. M-19 in the supernatant supplemented with 20{mu}gl{sup -1} Na{sub 2}MoO{sub 4} 2H{sub 2}O and 10mgl{sup -1} EDTA in a repeated batch culture with pH control at 7.5. Therefore, continuous hydrogen production with total hydrogen yield of 7.2 mol H{sub 2} mol{sup -1} glucose from the starch remaining in the starch residue was attained by the repeated batch culture with C. butyricum and E. aerogenes HO-39 and by the successive repeated batch culture with Rhodobacter sp. M-19. (Author)

  7. Efeito do bentazon e bentazon + dichlorprop na cultura do arroz irrigado e sobre as plantas daninhas Effect of bentazon and bentazon + dichlorprop on irrigated rice and weeds

    Directory of Open Access Journals (Sweden)

    C.A.L. dos Santos

    1979-06-01

    Full Text Available Foi instalado um experimento de campo, em solo barrento, com a finalidade de se verificar o efeito do bentazon e da mistura de bentazon + dichlorprop sobre o desenvolvimento do arroz em cultura irrigada e sobre o controle das plantas daninhas. Os tratamentos utilizados foram os seguintes: bentazon á 0,75-1,00 e1,50 kg/ha; bentazon + dichlorprop a 0,80 + 1,00 e 1,00 + 1,40 kg/ha; propanil a 4,20 kg/ha (tratamento padrão; testemunha capinada e testemunha sem capina. Todas as pulverizações foram realizadas em pósemergência. As plantas daninhas encontradas no experimento foram: capituva - Echinochloa colonum (L Link, tiririca amarela - Cyperus esculentus L., beldroega - Portulaca oleracea L. e carurú comum - Amaranthus viridis L. Bentazon a 1,00 e 1,50 kg/ha e bentazon + dichlorprop a 1,00 + 1,40 kg/ha foram eficientes no controle de P. oleracea, A. viridis e C. esculentus; já a dose menor de bentazon apresentou bons resultados contra P. oleracea e A. viridis, enquanto que a dose menor de bentazon + dichlorprop controlou apenas P. oleracea. Propanil, de uma maneira geral, proporcionou eficiente ação sobre as plantas daninhas. Nas condições em que foi realizado o experimento nenhum dos herbicidas, nas suas respectivas doses, apresentou fitotoxicidade para as plantas de arroz da variedade IAC-435 ou prejudicou a produção da cultura.Bentazon at 0.75 - 1.00 and 1.50 kg/ha a.i ., bentazon + dichlorprop at 0.80 + 1.00 and 1.00 + 1.40 kg and propanil at 4.20 kg were applied in post-emergence on irrigated rice, against the following weeds: Echinochloa colonum (L. Link, Cy-perus esc-ulentus L., Portulaca oleracea L. and Amaranthus viridis L. Bentazon at 1.00 - 1.50 kg and bentazon + dichlorprop at 1.00 + 1.40 kg gave good control of P. oleracea, A. viridis and C. esculentus; bentazon at 0.75 kg controlled P. oleracea and A. viridis; bentazon + dichlorprop at 0.80 + 1.00 kg only showed effeciency for P. oleracea; propanil, in general, gave good

  8. /sup 239/Pu contamination in snakes inhabiting the Rocky Flats Plant site

    Energy Technology Data Exchange (ETDEWEB)

    Geiger, R.A.; Winsor, T.F.

    1975-01-01

    For approximately four years studies have been under way at the Rocky Flats plant to determine contamination patterns and concentrations of Pu in the biota. Contamination of the Rocky Flats environs has resulted from at least three incidents, a September 1957 fire, a May 1969 fire, and leaking barrels containing plutonium-laden cutting oil. The latter incident was considered by far the major source of the plutonium contamination. Results are reported from a study conducted to determine whether snake tissues of the area contained detectable amounts of /sup 239/Pu and, if so, at what concentrations. Eastern yellow-bellied racers (Coluber constrictor flaviventris, bullsnakes (Pituophis melanoleucus sayi, and prairie rattlesnakes (Crotalus viridis viridis, were collected for /sup 239/Pu bioassay of lung, liver, and bone tissues. Snakes were captured using drift fences terminating in funnel traps and by opportunistic sampling. Results led to the conclusion that snakes are not an important organism in the redistribution of /sup 239/Pu. (CH)

  9. Spatial pattern and ecological process in the coffee agroforestry system.

    Science.gov (United States)

    Perfecto, Ivette; Vandermeer, John

    2008-04-01

    The coffee agroforestry system provides an ideal platform for the study of spatial ecology. The uniform pattern of the coffee plants and shade trees allows for the study of pattern generation through intrinsic biological forces rather than extrinsic habitat patchiness. Detailed studies, focusing on a key mutualism between an ant (Azteca instabilis) and a scale insect (Coccus viridis), conducted in a 45-ha plot in a coffee agroforestry system have provided insights into (1) the quantitative evaluation of spatial pattern of the scale insect Coccus viridis on coffee bushes, (2) the mechanisms for the generation of patterns through the combination of local satellite ant nest formation and regional control from natural enemies, and (3) the consequences of the spatial pattern for the stability of predator-prey (host-parasitoid) systems, for a key coccinelid beetle preying on the scale insects and a phorid fly parasitoid parasitizing the ant.

  10. 239Pu contamination in snakes inhabiting the Rocky Flats Plant site

    International Nuclear Information System (INIS)

    Geiger, R.A.; Winsor, T.F.

    1975-01-01

    For approximately four years studies have been under way at the Rocky Flats plant to determine contamination patterns and concentrations of Pu in the biota. Contamination of the Rocky Flats environs has resulted from at least three incidents, a September 1957 fire, a May 1969 fire, and leaking barrels containing plutonium-laden cutting oil. The latter incident was considered by far the major source of the plutonium contamination. Results are reported from a study conducted to determine whether snake tissues of the area contained detectable amounts of 239 Pu and, if so, at what concentrations. Eastern yellow-bellied racers (Coluber constrictor flaviventris, bullsnakes (Pituophis melanoleucus sayi, and prairie rattlesnakes (Crotalus viridis viridis, were collected for 239 Pu bioassay of lung, liver, and bone tissues. Snakes were captured using drift fences terminating in funnel traps and by opportunistic sampling. Results led to the conclusion that snakes are not an important organism in the redistribution of 239 Pu

  11. Weed Hosts of Meloidogyne arenaria and M. incognita Common in Tobacco Fields in South Carolina.

    Science.gov (United States)

    Tedford, E C; Fortnum, B A

    1988-10-01

    Thirty-two weed species common in South Carolina and one cultivar of tobacco were evaluated as hosts of Meloidogyne arenaria race 2 and M. incognita race 3 in the greenhouse. Egg mass production and galling differed (P Eleusine indica, Sorghum halepense, Setaria viridis, Digitaria sanguinalis, and Datura stramonium were poor hosts for M. arenaria. Amaranthus palmeri, Amaranthus hybridus, Chenopodium album, Euphorbia maculata, Setaria lutescens, Vicia villosa, Sida spinosa, Rumex crispus, and Portulaca oleracea were moderate hosts and Ipomoea hederacea var. integriuscula, Xanthium strumarium, Cyperus esculentus, Cynodon dactylon, Paspalum notatum, Eleusine indica, Setaria viridis, and Rumex acetosella were poor hosts for M. incognita. None of the above were good hosts for M. incognita. Tobacco 'PD4' supported large numbers of both nematode species.

  12. Global analysis of WRKY transcription factor superfamily in Setaria identifies potential candidates involved in abiotic stress signaling

    OpenAIRE

    Muthamilarasan, Mehanathan; Bonthala, Venkata S.; Khandelwal, Rohit; Jaishankar, Jananee; Shweta, Shweta; Nawaz, Kashif; Prasad, Manoj

    2015-01-01

    Transcription factors (TFs) are major players in stress signalling and constitute an integral part of signalling networks. Among the major TFs, WRKY proteins play pivotal roles in regulation of transcriptional reprogramming associated with stress responses. In view of this, genome- and transcriptome-wide identification of WRKY TF family was performed in the C4 model plants, Setaria italica (SiWRKY) and S. viridis (SvWRKY), respectively. The study identified 105 SiWRKY and 44 SvWRKY proteins t...

  13. Crotoxin: Structural Studies, Mechanism of Action and Cloning of Its Gene

    Science.gov (United States)

    1987-03-01

    with these same antisera, while cross-reactivity with B3-bungarotoxin was very slight. Neurophysin and phospholipase A2 from N. n. atra and honey bee ...toxin from Cror alus viridis concolor, and monoclonal antibodies to czotoxin. We have used these to search for cross-reactive, homologoiis proteins in...concolor, and monoclonal antibodies to crotoxin. We have used these to search for cross-reactive, homclogous proteins in other venoms and examine their

  14. Studies on free radical scavenging activity in Chinese seaweeds part I. Screening results

    Science.gov (United States)

    Yan, Xiao-Jun; Fang, Guo-Ming; Lou, Qing-Xiang

    1999-09-01

    Antioxidants have attracted the attention of researchers due to their beneficial effects as free radical scavengers. Application of a stable free radical named 1, 1-diphenyl-2-picrylhydrazyl(DPPH) to screen the free radical scavenging activity in 27 species of Chinese seaweed showed that 15 of them had significant activity in at least one of the organic solvent extracts. The most interesting seaweed species were Gelidium amansii, Gloiosiphonia capillaris, Polysiphonia urceolata, Sargassum kjellmanianum, Desmarestia viridis, and Rhodomela teres.

  15. Relações de interferência entre plantas daninhas e a cultura do grão-de-bico

    OpenAIRE

    Amaral, Carita Liberato do [UNESP; Pavan, Guilherme Bacarim [UNESP; Souza, Marcelo Claro de; Martins, José Valcir Fidelis [UNESP; Alves, Pedro Luis da Costa Aguiar [UNESP

    2015-01-01

    The grains of chickpea consumed in Brazil are almost entirely imported. Considering that chickpeas presents conditions to be cultivated in some regions of Brazil, this study aimed to study interference of six weed plants (Amaranthus viridis, Bidens pilosa, Raphanus raphanistrum, Cyperus rotundus, Digitaria nuda and Eleusine indica) on the vegetative development of chickpeas. Thus, we evaluated the shoot length, number of leaves, leaf area, chlorophyll content and dry weight of leaves, stem an...

  16. Indian marine bivalves: Potential source of antiviral drugs

    Digital Repository Service at National Institute of Oceanography (India)

    Chatterji, A.; Ansari, Z.A.; Ingole, B.S.; Bichurina, M.A.; Sovetova, M.; Boikov, Y.A.

    in large quantities by traditional methods and sold live in the market for human consumption. The economically important sp e cies of marine bivalves are green mussel ( Perna viridis ), e s tuarine oyster ( Crassostrea madrasensis ), giant oyster... in developing an effecti ve drug has been the unique characteristics of antigenic variation of virus resulting in the emergence of new variant virus strains 14 . There are a number of antiviral drugs introduced in the market such as tricyclic sy m- metric...

  17. The adaptive significance of ontogenetic colour change in a tropical python

    OpenAIRE

    Wilson, David; Heinsohn, Robert; Endler, John A

    2006-01-01

    Ontogenetic colour change is typically associated with changes in size, vulnerability or habitat, but assessment of its functional significance requires quantification of the colour signals from the receivers' perspective. The tropical python, Morelia viridis, is an ideal species to establish the functional significance of ontogenetic colour change. Neonates hatch either yellow or red and both the morphs change to green with age. Here, we show that colour change from red or yellow to green pr...

  18. Review of world genera of Ceinae, with the description of two new Palaearctic species of Spalangiopelta Masi (Hymenoptera, Chalcidoidea, Pteromalidae

    Directory of Open Access Journals (Sweden)

    Mircea-Dan Mitroiu

    2016-12-01

    Full Text Available The paper provides the first illustrated key to all described genera of Ceinae, i.e., Bohpa Darling, 1991, Cea Walker, 1837, and Spalangiopelta Masi, 1922. Based on the study of the original material, the genus Diparisca Hedqvist, 1964 stat. nov. is removed from the synonymy with Spalangiopelta and its higher classification is discussed. Spalangiopelta rameli sp. nov. and S. viridis sp. nov. are described from Greece and the Canary Islands, respectively.

  19. Ribosomal DNA in diploid and polyploid Setaria (Poaceae) species: number and distribution

    OpenAIRE

    Nani, Thaís Furtado; Cenzi, Gisele; Pereira, Daniele Lais; Davide, Lisete Chamma; Techio, Vania Helena

    2015-01-01

    Abstract Setaria Beauvois, 1812 is a genus of economically important forage species, including Setaria italica (Linnaeus, 1753) Beauvois, 1812 and Setaria viridis (Linnaeus, 1753) Beauvois, 1812, closely related species and considered as model systems for studies of C4 plants. However, complications and uncertainties related to taxonomy of other species of the genus are frequent due to the existence of numerous synonyms for the same species or multiple species with the same name, and overlapp...

  20. Ribosomal DNA in diploid and polyploid Setaria (Poaceae) species: number and distribution

    Science.gov (United States)

    Nani, Thaís Furtado; Cenzi, Gisele; Pereira, Daniele Lais; Davide, Lisete Chamma; Techio, Vânia Helena

    2015-01-01

    Abstract Setaria Beauvois, 1812 is a genus of economically important forage species, including Setaria italica (Linnaeus, 1753) Beauvois, 1812 and Setaria viridis (Linnaeus, 1753) Beauvois, 1812, closely related species and considered as model systems for studies of C4 plants. However, complications and uncertainties related to taxonomy of other species of the genus are frequent due to the existence of numerous synonyms for the same species or multiple species with the same name, and overlapping of morphological characteristics. Cytogenetic studies in Setaria can be useful for taxonomic and evolutionary studies as well as for applications in breeding. Thus, this study is aimed at locating 45S and 5S rDNA sites through fluorescent in situ hybridization (FISH) in Setaria italica, Setaria viridis and Setaria sphacelata (Schumacher, 1827) Stapf, Hubbard, Moss, 1929 cultivars (cvs.) Narok and Nandi. Setaria italica and Setaria viridis have 18 chromosomes with karyotype formulas 6m + 3sm and 9m, respectively. The location of 45S and 5S rDNA for these species was in different chromosome pairs among the evaluated species. Setaria viridis presented a more symmetrical karyotype, strengthening the ancestral relationship with Setaria italica. Setaria sphacelata cvs. Narok and Nandi have 36 chromosomes, and karyotype formulas 11m+7sm and 16m+2sm, respectively. The 45S rDNA signals for both cultivars were also observed in distinct chromosome pairs; however chromosomes bearing 5S rDNA are conserved. Karyotypic variations found among the studied species are evidence of chromosomal rearrangements. PMID:26753080

  1. Environmental Assessment: Permanent Western United States C-17 Landing Zone

    Science.gov (United States)

    2008-09-01

    Salix sp., Populus sp., Lemna minor , Cyperus sp. Delta Green Ground Beetle The Delta Green Ground Beetle, Elaphrus viridis Horn, 1878 is a...and the SCLA. Cumulative impacts can result from individually minor but collectively significant actions taking place over a period of time. None of...environmental effects on adjacent populations. Therefore, no disproportionately high and adverse effects will occur to minority and low-income

  2. Inhibition of alpha oscillations through serotonin-2A receptor activation underlies the visual effects of ayahuasca in humans

    OpenAIRE

    Valle, Marta; Ana Elda, Maqueda; Rabella, Mireia; Rodríguez Pujadas, Aina; Antonijoan Arbós, Rosa Maria; Romero Lafuente, Sergio; Alonso López, Joan Francesc; Mañanas Villanueva, Miguel Ángel; Barker, Steven; Friedlander, Pablo; Feilding, Amanda; Riba, Jordi

    2016-01-01

    Ayahuasca is an Amazonian psychotropic plant tea typically obtained from two plants, Banisteriopsis caapi and Psychotria viridis. It contains the psychedelic 5-HT2A and sigma-1 agonist N,N-dimethyltryptamine (DMT) plus ß-carboline alkaloids with monoamine-oxidase (MAO)-inhibiting properties. Although the psychoactive effects of ayahuasca have commonly been attributed solely to agonism at the 5-HT2A receptor, the molecular target of classical psychedelics, this has not been tested experimental...

  3. Distribution of Pink-Pigmented Facultative Methylotrophs on Leaves of Vegetables

    OpenAIRE

    MIZUNO, Masayuki; YURIMOTO, Hiroya; YOSHIDA, Naoko; IGUCHI, Hiroyuki; SAKAI, Yasuyoshi

    2012-01-01

    The distribution of pink-pigmented facultative methylotrophs (PPFMs) on the leaves of various vegetables was studied. All kinds of vegetable leaves tested gave pink-pigmented colonies on agar plates containing methanol as sole carbon source. The numbers of PPFMs on the leaves, colony-forming units (CFU)/g of fresh leaves, differed among the plants, although they were planted and grown at the same farm. Commercial green perilla, Perilla frutescens viridis (Makino) Makino, gave the highest coun...

  4. Étude de quelques Pucciniales liés aux plantes cultivées au Maroc

    African Journals Online (AJOL)

    SARAH

    2013-12-30

    Dec 30, 2013 ... Cette rouille n'a jamais été signalée auparavant sur Mentha viridis (hôte nouvel) dans le. Maroc. Au Maroc, Puccinia menthae Pers. (1801) a été rencontrée sur Mentha rotundifolia au lieu frais près d'Idni sur la route du Tizi n'Test (Haut Atlas), Satureja calamintha subsp. ascendes dans la pelouse au bord.

  5. [Is it possible to "cancel" aging process of cell cultures under optimal conditions for cultivation?].

    Science.gov (United States)

    Bozhkov, A I; Kovaleva, M K; Menzianova, N G

    2011-01-01

    The characteristics of the cells epigenotypes Dunaliella viridis Teod. in the process of chronological and replicative aging were investigated. By 40th day of accumulative cultivation (which coincided with the stationary growth phase) DNA content in the cells of Dunaliella viridis increased 2 times, triacylglycerides 3 times, beta-carotene and carbonyl proteins 2 times, RNA content decreased in comparison with cells in exponential growth phase, i. e., the 40th day of growth of culture forms the age-related epigenotype. 4 received subcultures were being transplanted during 2 years in mid-logarithmic growth phase (subculture-10), early stationary phase of growth (subculture-20), in the mid-stationary growth phase (subculture-30), and late stationary growth phase (subculture-40). It is shown that epigenotype of subculture-10 remained unchanged over 2 years of cultivation, i. e., it does not manifest replicative aging. At the same time, the subculture-20, although long enough (at least 40 passages), maintained epigenotype characteristic of young cultures, and showed age-related changes. Pronounced age-dependent changes of epigenotype in the course of cultivation were identified for subculture-30, and subculture-40 was characterized by unstable epigenotype. Thus, cultivation conditions determine the intensity of replicative aging in Dunaliella viridis.

  6. Differential expression of photosynthesis-related genes in pentaploid interspecific hybrid and its decaploid of Fragaria spp.

    Science.gov (United States)

    Wang, Tao; Huang, Dongya; Chen, Baoyu; Mao, Nini; Qiao, Yushan; Ji, Muxiang

    2018-03-01

    Polyploidization always induces a series of changes in genome, transcriptome and epigenetics, of which changes in gene expression are the immediate causes of genotype alterations of polyploid plants. In our previous study on strawberry polyploidization, genes related to photosynthesis were found to undergo changes in gene expression and DNA methylation. Therefore, we chose 11 genes that were closely related to plant photosynthesis and analysed their expression during strawberry hybridization and chromosome doubling. Most genes of pentaploids showed expression levels between parents and were more similar to F. × ananassa. Gene expression levels of decaploids were higher than those of pentaploids and F. × ananassa. Different types of photosynthesis-related genes responded differently to hybridization and chromosome doubling. Chloroplast genes and regulatory genes showed complex responses. Structural genes of the photosynthetic system were expressed at a constant level and displayed a clear dosage effect. The methylation levels of one CG site on SIGE, which regulates expression of chloroplast genes, were negatively correlated with gene expression. In pentaploids and decaploids, more transcripts were from F. × ananassa than from F. viridis. The ratio of transcripts from from F. × ananassa to those from F. viridis was close to the ratio (4:1) of the genome of F. × ananassa to that of F. viridis in pentaploids and decaploids, but there were also some exceptions with obvious deviation.

  7. Practical aspects of sea and fresh-water algae utilization

    International Nuclear Information System (INIS)

    Nyanishkene, V.B.; Zlobin, V.S.; Zheleznyakova, O.V.

    1988-01-01

    Regularities of sea and fresh-water microalgae cultivation, revealed during the operation of industrial plants, are presented in detail. The study of the Platymonas viridis cultivation mechanisms has shown the possibility of active intervention into the cycle of intense reproduction of the biomass. Among physical factors of the medium, which influence the reproduction of the industrial strain of Platymonas viridis, the effect of the red light, ultraviolet radiation, ultrahigh frequency fields and gamma radiation upon the cell division of these microalgae has been investigated. It has been shown that the effect of gamma radiation on the cell division of Platymonas viridis, other bacteria and protozoans is inhibiting. In the experiments using the radionuclides strontium-90 and cerium-144 as indicators of metabolism the dependence of the radionuclide accumulation factor on the quantity of stable lead as well as the effect of the temperature on the accumulation process have been studied. The coefficients of 90 Sr and 144 Ce accumulation by Nitellopsis obtusa cell compartments depending on stable lead and temperature are presented. 200 refs.; 21 figs.; 54 tabs

  8. Bio-accumulation kinetics of radioruthenium in marine bivalves. Laboratory study

    International Nuclear Information System (INIS)

    Mu, D.H.; Yan, S.P.; Gu, Y.J.; Li, D.J.; Du, J.Z.

    2007-01-01

    Three kinds of marine bivalves (wild Saccostrea cucullata, aquacultured Perna viridis and aquacultured Pinctada martens), collected from Daya Bay, the South China Sea, were used to investigate the bio-accumulation of radioruthenium in the glass aquarium with natural seawater (pH 8.20, 35 per mille salinity, filtered by 0.45 μm) at ambient temperature under laboratory feeding conditions. The experimental results show that the stead-state of biology concentration factor (BCF, ml/g) of radioruthenium was approached around 6 days for most species of bivalves. The values of BCF in shells are the highest in organs all the three bivalves. The orders of BCF values (ml x g -1 ) are as: Perna viridis (33.2) < Saccostrea cucullata (47.0) < Pinctada martensi (208.4) for shells and Saccostrea cucullata (1.5) < Pinctada martensi (2.2) ∼ Perma viridis (2.4) for soft tissues, respectively, after exposed for 14 days. The rate constants of uptake and elimination of radioruthenium on marine bivalves were also discussed by first-order kinetics model. The Pinctada martensi may be applicable to be an indictor for monitoring radioruthenium among the three bivalves. (author)

  9. Research on the Strength Variation of Root-Clay Systems under Freeze-Thaw Action

    Directory of Open Access Journals (Sweden)

    Lin Yang

    2017-01-01

    Full Text Available The aim of this paper is to study the influence of an effective root system of rhizome plants on the reinforcement of slope soil under freeze-thaw conditions. This study focused on the mechanical properties between roots and clay in the root system of four plant species from different regions of China (northeast, northern, central, and southern areas: Setaria viridis, Eleusine indica, Zoysia japonica, and Carex leucochlora. Based on the interfacial friction effects between the plant roots and the soil, pull-out tests and unconfined compressive strength tests were conducted on the reinforced soil system for varying numbers of freeze-thaw cycles. Several stages of the pull-out process of the root system in clay are explicitly proposed based on the interfacial friction test results. The results showed that the friction effect between Zoysia japonica roots and the soil was the most significant and that these roots had the best reinforcement effect. In contrast, the friction and reinforcement effects between Setaria viridis roots and the soil were the worst, and the resulting unconfined compressive strength was the smallest. However, the freeze-thaw resistance ability of the Setaria viridis and soil system was stronger than that of the Zoysia japonica system.

  10. Tubulin-isotype analysis of two grass species-resistant to dinitroaniline herbicides.

    Science.gov (United States)

    Waldin, T R; Ellis, J R; Hussey, P J

    1992-09-01

    Trifluralin-resistant biotypes of Eleusine indica (L.) Gaertn. (goosegrass) and Setaria viridis (L.) Beauv. (green foxtail) exhibit cross-resistance to other dinitroaniline herbicides. Since microtubules are considered the primary target site for dinitroaniline herbicides we investigated whether the differential sensitivity of resistant and susceptible biotypes of these species results from modified tubulin polypeptides. One-dimensional and two-dimensional polyacrylamide gel electrophoresis combined with immunoblotting using well-characterised anti-tubulin monoclonal antibodies were used to display the family of tubulin isotypes in each species. Seedlings of E. indica exhibited four β-tubulin isotypes and one α-tubulin isotype, whereas those of S. viridis exhibited two β-tubulin and two α-tubulin isotypes. Comparison of the susceptible and resistant biotypes within each species revealed no differences in electrophoretic properties of the multiple tubulin isotypes. These results provide no evidence that resistance to dinitroaniline herbicides is associated with a modified tubulin polypeptide in these biotypes of E. indica or S. viridis.

  11. Phytotoxicity Study on Bidens sulphurea Sch. Bip. as a Preliminary Approach for Weed Control.

    Science.gov (United States)

    da Silva, Bruna P; Nepomuceno, Mariluce P; Varela, Rosa M; Torres, Ascensión; Molinillo, José M G; Alves, Pedro L C A; Macías, Francisco A

    2017-06-28

    Farmers of the Franca region in Brazil observed that Bidens sulphurea was able to eliminate the Panicum maximum weed, which infected coffee plantations, without affecting the crop. In an effort to determine if the inhibitory effects observed were due to the presence of phytotoxic compounds from leaves and roots, a biodirected isolation and spectroscopic characterization has been carried out. The leaf dichloromethane and root acetone extracts were the most active, and the former appeared to be more phytotoxic to the target species, including four weeds. A total of 26 compounds were isolated from leaves and roots, and four of them are described here for the first time. The major compounds in the leaf extract are the sesquiterpene lactones costunolide, reynosin, and santamarine, and these showed marked inhibition. Amaranthus viridis and Panicum maximum were the most sensitive species of the weeds tested. These three phytotoxic lactones were also evaluated on A. viridis and P. maximum under hydroponic conditions. A. viridis was the most affected species with the three lactones, and santamarine was the most phytotoxic compound on both. This is the first time that the phytotoxicity of sesquiterpene lactones has been evaluated on hydroponic culture. The work described here is a preliminary approach for the use of B. sulphurea for weed control in agriculture, both as a cover crop and by use of its components as natural herbicide leads.

  12. Imaging of solid tumor using near-infrared emitting purple bacteria

    International Nuclear Information System (INIS)

    Moon, Sung Min; Min, Jung Joon; Kim, Sun A; Choy, Hyon E.; Bom, Hee Seung

    2005-01-01

    Rhodobacter sphaeroides 2.4.1 is α-3 purple nonsulfur eubacterium with an extensive metabolism. Under anaerobic conditions, it is able to grow by photosynthesis, respiration and fermentation. When grown photosynthetically, it uses wavelengths of light in the near-infrared and contains a reaction center that is the peripheral light-harvesting (LH2) complex. These molecules absorb and emit near-infrared light. Using this near-infrared fluorescent bacterial we investigated its targeting capacity of solid tumor in small animals. R. sphaeroides 2.4.1 strains were cultured in sistrons minimal medium A (SIS) at 32 C. Xenograft tumor model has been established by subcutaneous injection of CT26 mouse colon cancer cell line. 1X10 8 Rhodobacter sphaeroides cells suspended in 100 ul of PBS were injected via tail vein with 1-cc insulin syringe into tumor bearing mouse. In vivo fluorescence imaging has been done after 20 min to 30 days of purple bacteria using indocyanine (ICG) emission filter (Em=810∼835 nm). Near-infrared imaging signal from Rhodobacter sphaeroides was initially detected at liver for 3 days but at the necrotic region of tumor mass thereafter. Total photon flux measured 5.5X10 8 (p/s/cm 2 /sr) at Day 1. Also it was increased to 7.8X10 8 (p/s/cm 2 /sr) at 12 day. One of important characteristic is that the signal appeared only at central necrosis area. It has been monitored for 36 day. We successfully imaged cancer with near-infrared fluorescence bacteria. Our result indicate that near-infrared fluorescence purple bacteria are able to be used to monitor bacterial trafficking in living tumor models

  13. Bacterial PerO Permeases Transport Sulfate and Related Oxyanions.

    Science.gov (United States)

    Hoffmann, Marie-Christine; Pfänder, Yvonne; Tintel, Marc; Masepohl, Bernd

    2017-07-15

    Rhodobacter capsulatus synthesizes the high-affinity ABC transporters CysTWA and ModABC to specifically import the chemically related oxyanions sulfate and molybdate, respectively. In addition, R. capsulatus has the low-affinity permease PerO acting as a general oxyanion transporter, whose elimination increases tolerance to molybdate and tungstate. Although PerO-like permeases are widespread in bacteria, their function has not been examined in any other species to date. Here, we present evidence that PerO permeases from the alphaproteobacteria Agrobacterium tumefaciens , Dinoroseobacter shibae , Rhodobacter sphaeroides , and Sinorhizobium meliloti and the gammaproteobacterium Pseudomonas stutzeri functionally substitute for R. capsulatus PerO in sulfate uptake and sulfate-dependent growth, as shown by assimilation of radioactively labeled sulfate and heterologous complementation. Disruption of perO genes in A. tumefaciens , R. sphaeroides , and S. meliloti increased tolerance to tungstate and, in the case of R. sphaeroides , to molybdate, suggesting that heterometal oxyanions are common substrates of PerO permeases. This study supports the view that bacterial PerO permeases typically transport sulfate and related oxyanions and, hence, form a functionally conserved permease family. IMPORTANCE Despite the widespread distribution of PerO-like permeases in bacteria, our knowledge about PerO function until now was limited to one species, Rhodobacter capsulatus In this study, we showed that PerO proteins from diverse bacteria are functionally similar to the R. capsulatus prototype, suggesting that PerO permeases form a conserved family whose members transport sulfate and related oxyanions. Copyright © 2017 American Society for Microbiology.

  14. Directed assembly of functional light harvesting antenna complexes onto chemically patterned surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Escalante, Maryana [Biophysical Engineering Group, MESA and Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands); Maury, Pascale [Molecular Nanofabrication Group, MESA and Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands); Bruinink, Christiaan M [Molecular Nanofabrication Group, MESA and Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands); Werf, Kees van der [Biophysical Engineering Group, MESA and Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands); Olsen, John D [Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN (United Kingdom); Timney, John A [Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN (United Kingdom); Huskens, Jurriaan [Molecular Nanofabrication Group, MESA and Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands); Hunter, C Neil [Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN (United Kingdom); Subramaniam, Vinod [Biophysical Engineering Group, MESA and Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands); Otto, Cees [Biophysical Engineering Group, MESA and Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands)

    2008-01-16

    We report the directed assembly of the photosynthetic membrane proteins LH1 and LH2 isolated from the purple bacterium Rhodobacter sphaeroides onto chemically patterned substrates. Nanoimprint lithography was used to pattern discrete regions of amino- and fluoro-terminated or poly(ethylene glycol) self-assembled monolayers onto a glass substrate. Densely packed layers of assembled protein complexes were observed with atomic force microscopy. The protein complexes attached selectively to the amino-terminated regions by electrostatic interactions. Spectral images generated with a hybrid scanning probe and fluorescence microscope confirmed that the patterned proteins retained their native optical signatures.

  15. Self-trapped excitons in LH2 bacteriochlorophyll-protein complexes under high pressure

    International Nuclear Information System (INIS)

    Timpmann, K.; Ellervee, Aleksandr; Kuznetsov, Anatoli; Laisaar, Arlentin; Trinkunas, Gediminas; Freiberg, Arvi

    2003-01-01

    The absorption and emission spectra of excitons in LH2 antenna complexes from the photosynthetic purple bacterium Rhodobacter sphaeroides have been studied under hydrostatic pressure. The measurements made between ambient pressure and 6 kbar over a broad temperature range reveal largely different rates of the pressure-induced shifts for the absorption and emission bands. Numerical calculations based on exciton polaron model provide evidence for the exciton self-trapping at ambient pressure as well as for the pressure stabilization of the self-trapped exciton states responsible for the emission, whereas the light absorbing states belong to nearly free excitons over the whole pressure and temperature ranges studied

  16. Parameterization of the prosthetic redox centers of the bacterial cytochrome bc(1) complex for atomistic molecular dynamics simulations

    DEFF Research Database (Denmark)

    Kaszuba, K.; Postila, P. A.; Cramariuc, O.

    2013-01-01

    studied in large-scale classical molecular dynamics (MD) simulations. In part, this is due to lack of suitable force field parameters, centered atomic point charges in particular, for the complex's prosthetic redox centers. Accurate redox center charges are needed to depict realistically the inter-molecular...... interactions at different redox stages of the cyt bc(1) complex. Accordingly, here we present high-precision atomic point charges for the metal centers of the cyt bc(1) complex of Rhodobacter capsulatus derived from extensive density functional theory calculations, fitted using the restrained electrostatic...

  17. Directed assembly of functional light harvesting antenna complexes onto chemically patterned surfaces

    International Nuclear Information System (INIS)

    Escalante, Maryana; Maury, Pascale; Bruinink, Christiaan M; Werf, Kees van der; Olsen, John D; Timney, John A; Huskens, Jurriaan; Hunter, C Neil; Subramaniam, Vinod; Otto, Cees

    2008-01-01

    We report the directed assembly of the photosynthetic membrane proteins LH1 and LH2 isolated from the purple bacterium Rhodobacter sphaeroides onto chemically patterned substrates. Nanoimprint lithography was used to pattern discrete regions of amino- and fluoro-terminated or poly(ethylene glycol) self-assembled monolayers onto a glass substrate. Densely packed layers of assembled protein complexes were observed with atomic force microscopy. The protein complexes attached selectively to the amino-terminated regions by electrostatic interactions. Spectral images generated with a hybrid scanning probe and fluorescence microscope confirmed that the patterned proteins retained their native optical signatures

  18. Defluviimonas denitrificans gen. nov., sp. nov., and Pararhodobacter aggregans gen. nov., sp. nov., non-phototrophic Rhodobacteraceae from the biofilter of a marine aquaculture

    DEFF Research Database (Denmark)

    Foesel, Bärbel U.; Drake, Harold L.; Schramm, Andreas

    2011-01-01

    Three Gram-negative bacterial strains were isolated from the biofilter of a recirculating marine aquaculture. They were non-pigmented rods, mesophiles, moderately halophilic, and showed chemoorganoheterotrophic growth on various sugars, fatty acids, and amino acids, with oxygen as electron acceptor......, but clearly separate from, the genera Rhodobacter, Rhodovulum, and Rhodobaca. Based on morphological, physiological, and 16S rRNA-based phylogenetic characteristics, the isolated strains are proposed as new species of two novel genera, Defluviimonas denitrificans gen. nov., sp. nov. (type strain D9-3T = DSM...

  19. Interaction of two photoreceptors in the regulation of bacterial photosynthesis genes

    OpenAIRE

    Metz, Sebastian; Haberzettl, Kerstin; Frühwirth, Sebastian; Teich, Kristin; Hasewinkel, Christian; Klug, Gabriele

    2012-01-01

    The expression of photosynthesis genes in the facultatively photosynthetic bacterium Rhodobacter sphaeroides is controlled by the oxygen tension and by light quantity. Two photoreceptor proteins, AppA and CryB, have been identified in the past, which are involved in this regulation. AppA senses light by its N-terminal BLUF domain, its C-terminal part binds heme and is redox-responsive. Through its interaction to the transcriptional repressor PpsR the AppA photoreceptor controls expression of ...

  20. Molecular Regulation of Photosynthetic Carbon Dioxide Fixation in Nonsulfur Purple Bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Tabita, Fred Robert [The Ohio State Univ., Columbus, OH (United States)

    2015-12-01

    The overall objective of this project is to determine the mechanism by which a transcriptional activator protein affects CO2 fixation (cbb) gene expression in nonsulfur purple photosynthetic bacteria, with special emphasis to Rhodobacter sphaeroides and with comparison to Rhodopseudomonas palustris. These studies culminated in several publications which indicated that additional regulators interact with the master regulator CbbR in both R. sphaeroides and R. palustris. In addition, the interactive control of the carbon and nitrogen assimilatory pathways was studied and unique regulatory signals were discovered.