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Sample records for algal community growing

  1. Molecular evidence for a diverse green algal community growing in the hair of sloths and a specific association with Trichophilus welckeri (Chlorophyta, Ulvophyceae

    Directory of Open Access Journals (Sweden)

    Chiarello Adriano G

    2010-03-01

    Full Text Available Abstract Background Sloths are slow-moving arboreal mammals inhabiting tropical rainforests in Central and South America. The six living species of sloths are occasionally reported to display a greenish discoloration of their pelage. Trichophilus welckeri, a green algal species first described more than a century ago, is widely believed to discolor the animals fur and provide the sloth with effective camouflage. However, this phenomenon has not been explored in any detail and there is little evidence to substantiate this widely held opinion. Results Here we investigate the genetic diversity of the eukaryotic community present in fur of all six extant species of sloth. Analysis of 71 sloth hair samples yielding 426 partial 18S rRNA gene sequences demonstrates a diverse eukaryotic microbial assemblage. Phylogenetic analysis reveals that sloth fur hosts a number of green algal species and suggests that acquisition of these organisms from the surrounding rainforest plays an important role in the discoloration of sloth fur. However, an alga corresponding to the morphological description of Trichophilus welckeri was found to be frequent and abundant on sloth fur. Phylogenetic analysis demonstrated the retention of this alga on the fur of sloths independent of geographic location. Conclusions These results demonstrate a unique diverse microbial eukaryotic community in the fur of sloths from Central and South America. Our analysis streghtens the case for symbiosis between sloths and Trichophilus welckeri.

  2. Exploring the Utilization of Complex Algal Communities to Address Algal Pond Crash and Increase Annual Biomass Production for Algal Biofuels

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, Cyd E. [Dept. of Energy (DOE), Washington DC (United States).

    2014-03-25

    This white paper briefly reviews the research literature exploring complex algal communities as a means of increasing algal biomass production via increased tolerance, resilience, and resistance to a variety of abiotic and biotic perturbations occurring within harvesting timescales. This paper identifies what data are available and whether more research utilizing complex communities is needed to explore the potential of complex algal community stability (CACS) approach as a plausible means to increase biomass yields regardless of ecological context and resulting in decreased algal-based fuel prices by reducing operations costs. By reviewing the literature for what we do and do not know, in terms of CACS methodologies, this report will provide guidance for future research addressing pond crash phenomena.

  3. Growing Virtual Communities

    Science.gov (United States)

    Garber, Debbie

    2004-01-01

    As online collaborative technologies become easier to use, an increasing range of "virtual communities" are being established, often for educational purposes. This report stresses that an efficient technology is only part of the process underlying a successful online community. It considers the social process on which an online learning community…

  4. Evaluation of attached periphytical algal communities for biofuel feedstock generation

    Energy Technology Data Exchange (ETDEWEB)

    Sandefur, H.N.; Matlock, M.D.; Costello, T.A. [Arkansas Univ., Division of Agriculture, Fayetteville, AR (United States). Dept. of Biological and Agricultural Engineering, Center for Agricultural and Rural Sustainability

    2010-07-01

    This paper reported on a study that investigated the feasibility of using algal biomass as a feedstock for biofuel production. Algae has a high lipid content, and with its high rate of production, it can produce more oil on less land than traditional bioenergy crops. In addition, algal communities can remove nutrients from wastewater. Enclosed photobioreactors and open pond systems are among the many different algal growth systems that can be highly productive. However, they can also be difficult to maintain. The objective of this study was to demonstrate the ability of a pilot scale algal turf scrubber (ATS) to facilitate the growth of attached periphytic algal communities for the production of biomass feedstock and the removal of nutrients from a local stream in Springdale, Arizona. The ATS operated for a 9 month sampling period, during which time the system productivity averaged 26 g per m{sup 2} per day. The removal of total phosphorus and total nitrogen averaged 48 and 13 per cent, respectively.

  5. Microbial communities mediating algal detritus turnover under anaerobic conditions

    Directory of Open Access Journals (Sweden)

    Jessica M. Morrison

    2017-01-01

    Full Text Available Background Algae encompass a wide array of photosynthetic organisms that are ubiquitously distributed in aquatic and terrestrial habitats. Algal species often bloom in aquatic ecosystems, providing a significant autochthonous carbon input to the deeper anoxic layers in stratified water bodies. In addition, various algal species have been touted as promising candidates for anaerobic biogas production from biomass. Surprisingly, in spite of its ecological and economic relevance, the microbial community involved in algal detritus turnover under anaerobic conditions remains largely unexplored. Results Here, we characterized the microbial communities mediating the degradation of Chlorella vulgaris (Chlorophyta, Chara sp. strain IWP1 (Charophyceae, and kelp Ascophyllum nodosum (phylum Phaeophyceae, using sediments from an anaerobic spring (Zodlteone spring, OK; ZDT, sludge from a secondary digester in a local wastewater treatment plant (Stillwater, OK; WWT, and deeper anoxic layers from a seasonally stratified lake (Grand Lake O’ the Cherokees, OK; GL as inoculum sources. Within all enrichments, the majority of algal biomass was metabolized within 13–16 weeks, and the process was accompanied by an increase in cell numbers and a decrease in community diversity. Community surveys based on the V4 region of the 16S rRNA gene identified different lineages belonging to the phyla Bacteroidetes, Proteobacteria (alpha, delta, gamma, and epsilon classes, Spirochaetes, and Firmicutes that were selectively abundant under various substrate and inoculum conditions. Within all kelp enrichments, the microbial communities structures at the conclusion of the experiment were highly similar regardless of the enrichment source, and were dominated by the genus Clostridium, or family Veillonellaceae within the Firmicutes. In all other enrichments the final microbial community was dependent on the inoculum source, rather than the type of algae utilized as substrate

  6. Microbial communities mediating algal detritus turnover under anaerobic conditions

    Science.gov (United States)

    Morrison, Jessica M.; Murphy, Chelsea L.; Baker, Kristina; Zamor, Richard M.; Nikolai, Steve J.; Wilder, Shawn; Elshahed, Mostafa S.

    2017-01-01

    Background Algae encompass a wide array of photosynthetic organisms that are ubiquitously distributed in aquatic and terrestrial habitats. Algal species often bloom in aquatic ecosystems, providing a significant autochthonous carbon input to the deeper anoxic layers in stratified water bodies. In addition, various algal species have been touted as promising candidates for anaerobic biogas production from biomass. Surprisingly, in spite of its ecological and economic relevance, the microbial community involved in algal detritus turnover under anaerobic conditions remains largely unexplored. Results Here, we characterized the microbial communities mediating the degradation of Chlorella vulgaris (Chlorophyta), Chara sp. strain IWP1 (Charophyceae), and kelp Ascophyllum nodosum (phylum Phaeophyceae), using sediments from an anaerobic spring (Zodlteone spring, OK; ZDT), sludge from a secondary digester in a local wastewater treatment plant (Stillwater, OK; WWT), and deeper anoxic layers from a seasonally stratified lake (Grand Lake O’ the Cherokees, OK; GL) as inoculum sources. Within all enrichments, the majority of algal biomass was metabolized within 13–16 weeks, and the process was accompanied by an increase in cell numbers and a decrease in community diversity. Community surveys based on the V4 region of the 16S rRNA gene identified different lineages belonging to the phyla Bacteroidetes, Proteobacteria (alpha, delta, gamma, and epsilon classes), Spirochaetes, and Firmicutes that were selectively abundant under various substrate and inoculum conditions. Within all kelp enrichments, the microbial communities structures at the conclusion of the experiment were highly similar regardless of the enrichment source, and were dominated by the genus Clostridium, or family Veillonellaceae within the Firmicutes. In all other enrichments the final microbial community was dependent on the inoculum source, rather than the type of algae utilized as substrate. Lineages enriched

  7. Variations of algal communities cause darkening of a Greenland glacier.

    Science.gov (United States)

    Lutz, Stefanie; Anesio, Alexandre M; Jorge Villar, Susana E; Benning, Liane G

    2014-08-01

    We have assessed the microbial ecology on the surface of Mittivakkat glacier in SE-Greenland during the exceptional high melting season in July 2012 when the so far most extreme melting rate for the Greenland Ice Sheet has been recorded. By employing a complementary and multi-disciplinary field sampling and analytical approach, we quantified the dramatic changes in the different microbial surface habitats (green snow, red snow, biofilms, grey ice, cryoconite holes). The observed clear change in dominant algal community and their rapidly changing cryo-organic adaptation inventory was linked to the high melting rate. The changes in carbon and nutrient fluxes between different microbial pools (from snow to ice, cryoconite holes and glacial forefronts) revealed that snow and ice algae dominate the net primary production at the onset of melting, and that they have the potential to support the cryoconite hole communities as carbon and nutrient sources. A large proportion of algal cells is retained on the glacial surface and temporal and spatial changes in pigmentation contribute to the darkening of the snow and ice surfaces. This implies that the fast, melt-induced algal growth has a high albedo reduction potential, and this may lead to a positive feedback speeding up melting processes.

  8. Snow algal communities on glaciers in the Suntar-Khayata Mountain Range in eastern Siberia, Russia

    Science.gov (United States)

    Tanaka, Sota; Takeuchi, Nozomu; Miyairi, Masaya; Fujisawa, Yuta; Kadota, Tsutomu; Shirakawa, Tatsuo; Kusaka, Ryo; Takahashi, Shuhei; Enomoto, Hiroyuki; Ohata, Tetsuo; Yabuki, Hironori; Konya, Keiko; Fedorov, Alexander; Konstantinov, Pavel

    2016-09-01

    Snow and ice algal communities were investigated on four glaciers in the Suntar-Khayata Mountain Range in eastern Siberia in Russia over three melting seasons from 2012 to 2014. Two taxa of green algae and five taxa of cyanobacteria were observed on the glaciers. The algal community was dominated by green algae: Ancylonema nordenskioldii in the lower bare ice area and Chloromonas sp. in the upper snow area. The total algal bio-volume showed altitudinal variation, ranging from 0.03 to 4.0 mL m-2, and was greatest in the middle of the glaciers. The altitudinal variations in the algal community were similar on all studied glaciers, suggesting that they are typical in this region. Observations over the three years revealed that there was no significant change in the community structure, but a significant change in the total biomass. Since the mean summer air temperature was significantly higher in 2012 when algal biomass was greater, the difference in algal biomass among the years is probably due to the duration of surface melting. The community structure on the studied glaciers is similar to those on glaciers in Arctic and sub-Arctic regions.

  9. Effect of Tetracycline Antibiotics on Performance and Microbial Community of Algal Photo-Bioreactor.

    Science.gov (United States)

    Taşkan, Ergin

    2016-07-01

    Tetracycline antibiotics have been increasingly used in medical applications and have been found in wastewater treatment plants as a result of human and industrial activities. This study investigates the combined effects of tetracycline antibiotics on the performance of an algal photo-bioreactor operated under different antibiotic concentrations in the ranges of 0.25 to 30 mg/L and considers the inhibition of algal growth, carbon and nutrient removal rates, and eukaryotic and cyanobacterial algal community changes. The results indicated that increases in the concentration of tetracycline mixtures have adverse effects on the algal community and the performance of a photo-bioreactor, and the eukaryotic algae species were more sensitive to tetracycline antibiotics than were the cyanobacterial species. Cultivation tests showed that approximately 94 % growth inhibition of mixed algae occurred at 30 mg/L.

  10. Abundance, biomass and composition of spring ice algal and phytoplankton communities of the Laptev Sea (Arctic)

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Abundance, biomass and composition of the ice algal and phytoplankton communities were investigated in the southeastern Laptev Sea in spring 1999.Diatoms dominated the algal communities and pennate diatoms dominated the diatom population. 12 dominant algal species occurred within sea ice and underlying water column, including Fragilariopsis oceanica, F. cylindrus, Nitzschia frigida , N. promare, Achnanthes taeniata , Nitzschia neofrigida , Navicula pelagica , N. vanhoef fenii, N. septentrionalis, Melosira arctica , Clindrotheca closterium and Pyramimonas sp. The algal abundance of bottom 10 cm sea ice varied between 14.6 and 1562.2 × 104 cells l-1 with an average of 639.0 × 104cells l-1 , and the algal biomass ranged from 7.89 to 2093.5 μg C l-1 with an average of 886.9 μg C l-1 , which were generally one order of magnitude higher than those of sub-bottom ice and two orders of magnitude higher than those of underlying surface water. The integrated algal abundance and biomass of lowermost 20 cm ice column were averagely 7.7 and 12.2 times as those of upper 20 m water column, respectively, suggesting that the ice algae might play an important role in maintaining the coastal marine ecosystem before the thawing of sea ice. Ice algae influenced the phytoplankton community of the underlying water column.However, the "seeding" of ice algae for phytoplankton bloom was negligible because of the low phytoplankton biomass within the underlying water column.

  11. Technical Evaluation Report 34: Growing Virtual Communities

    Directory of Open Access Journals (Sweden)

    Debbie Garber

    2004-08-01

    Full Text Available As online collaborative technologies become easier to use, an increasing range of “virtual communities” are being established, often for educational purposes. This report stresses that an efficient technology is only part of the process underlying a successful online community. It considers the social process on which an online learning community must be founded if it is to flourish and be useful. Definitions of community, learning community, and virtual learning community are reviewed, and the experience of an online community member is discussed. The importance of nurturing the community’s health, and the natural life cycle of a virtual community, are examined.

  12. Technical Evaluation Report 34: Growing Virtual Communities

    OpenAIRE

    Debbie Garber

    2004-01-01

    As online collaborative technologies become easier to use, an increasing range of “virtual communities” are being established, often for educational purposes. This report stresses that an efficient technology is only part of the process underlying a successful online community. It considers the social process on which an online learning community must be founded if it is to flourish and be useful. Definitions of community, learning community, and virtual learning community are reviewed, and t...

  13. Assessing sewage impact in a South-West Atlantic rocky shore intertidal algal community.

    Science.gov (United States)

    Becherucci, Maria Eugenia; Santiago, Lucerito; Benavides, Hugo Rodolfo; Vallarino, Eduardo Alberto

    2016-05-15

    The spatial and seasonal variation of the specific composition and community parameters (abundance, diversity, richness and evenness) of the intertidal algal assemblages was studied at four coastal sampling sites, distributed along an environmental gradient from the sewage water outfall of Mar del Plata, Buenos Aires, Argentina. Two of them were located close to the sewage outfall (<800m) (impacted area) and the two other were 8 and 9km distant (non-impacted area). The algal abundance was monthly analyzed from October 2008 to May 2009. The algal assemblages varied according to the pollution gradient in spring, summer and autumn, being autumn the season when the highest difference was observed. Ceramium uruguayense was recognized as an indicator species for the non-impacted areas, while Berkeleya sp. represented an indicator species for the sewage outfall impact. Ulva spp. did not reflect the typical pattern observed for other sewage pollution areas.

  14. Summary of Algal Community Changes Observed on the Southwest Arm of Rose Atoll from 1995-2002

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This brief summary of observed changes in the reef-top algal community at Rose Atoll NWR is prepared specifically to address the questions posed by the NPFC on...

  15. Stress-Survival Gene Identification From an Acid Mine Drainage Algal Mat Community

    Science.gov (United States)

    Urbina-Navarrete, J.; Fujishima, K.; Paulino-Lima, I. G.; Rothschild-Mancinelli, B.; Rothschild, L. J.

    2014-12-01

    Microbial communities from acid mine drainage environments are exposed to multiple stressors to include low pH, high dissolved metal loads, seasonal freezing, and desiccation. The microbial and algal communities that inhabit these niche environments have evolved strategies that allow for their ecological success. Metagenomic analyses are useful in identifying species diversity, however they do not elucidate the mechanisms that allow for the resilience of a community under these extreme conditions. Many known or predicted genes encode for protein products that are unknown, or similarly, many proteins cannot be traced to their gene of origin. This investigation seeks to identify genes that are active in an algal consortium during stress from living in an acid mine drainage environment. Our approach involves using the entire community transcriptome for a functional screen in an Escherichia coli host. This approach directly targets the genes involved in survival, without need for characterizing the members of the consortium.The consortium was harvested and stressed with conditions similar to the native environment it was collected from. Exposure to low pH (DNA (cDNA) libraries in E. coli. The transformed E. coli were exposed to the same stressors as the original algal consortium to select for surviving cells. Successful cells incorporated the transcripts that encode survival mechanisms, thus allowing for selection and identification of the gene(s) involved. Initial selection screens for freeze and desiccation tolerance have yielded E. coli that are 1 order of magnitude more resistant to freezing (0.01% survival of control with no transcript, 0.2% survival of E. coli with transcript) and 3 orders of magnitude more resistant to desiccation (0.005% survival of control cells with no transcripts, 5% survival of cells with transcript).This work is transformative because genetic functions can be selected without having prior knowledge of the genes or of the organisms involved

  16. Plankton communities and summertime declines in algal abundance associated with low dissolved oxygen in the Tualatin River, Oregon

    Science.gov (United States)

    Carpenter, Kurt D.; Rounds, Stewart A.

    2013-01-01

    during much of the growing season. A general seasonal trend in the phytoplankton assemblages was observed, with dominance by filamentous centric diatoms Stephanodiscus and Melosira in spring and early summer, and flagellated cryptophytes and green algae, particularly Chlamydomonas sp., in late-summer; or, in 2008, dominance by blue-green algae Anabaena flos-aquae and Aphanizomenon flos-aquae during the Wapato Lake bloom event. There were 99 zooplankton taxa identified from the Tualatin River in 2006–08, composed primarily of cladocerans, copepods, and rotifers. A seasonal increase in zooplankton abundance was observed in early summer just as or shortly after the phytoplankton population began to increase, with populations growing to 15,000−120,000 organisms per cubic meter in the lower river. Zooplankton abundance showed a predictable and distinct longitudinal downstream increase, particularly downstream of Highway 99W (RM 11.6). Although grazing rates were not measured, the data suggest that, at times, zooplankton grazing may affect algal abundance and species composition in the Tualatin River, with diatoms becoming relatively less abundant and flagellated cryptophytes and green algae relatively more abundant during periods when zooplankton densities were highest. Multivariate statistical analyses identified soluble reactive phosphorus (SRP), natural flow, flow augmentation, and WWTF effluent as important factors influencing Tualatin River phytoplankton populations, with zooplankton density (particularly rotifers and copepods), specific conductance, chloride, and water temperature also having an important influence. Although SRP was highly correlated with the plankton communities, that correlation was likely the result of high or low algal activity (uptake) as SRP concentrations were often reduced to low levels during blooms. While previous studies have already established that phosphorus, among other factors such as flow, places a theoretical cap on the size of the

  17. Diffusive boundary layers and photosynthesis of the epilithic algal community of coral reefs

    DEFF Research Database (Denmark)

    Larkum, Anthony W.D.; Koch, Eva-Maria W.; Kühl, Michael

    2003-01-01

    The effects of mass transfer resistance due to the presence of a diffusive boundary layer on the photosynthesis of the epilithic algal community (EAC) of a coral reef were studied. Photosynthesis and respiration of the EAC of dead coral surfaces were investigated for samples from two locations......: the Gulf of Aqaba, Eilat (Israel), and One Tree Reef on the Great Barrier Reef (Australia). Microsensors were used to measure O2 and pH at the EAC surface and above. Oxygen profiles in the light and dark indicated a diffusive boundary layer (DBL) thickness of 180–590 µm under moderate flow (~0.08 m s-1...

  18. Growing networks of overlapping communities with internal structure

    Science.gov (United States)

    Young, Jean-Gabriel; Hébert-Dufresne, Laurent; Allard, Antoine; Dubé, Louis J.

    2016-08-01

    We introduce an intuitive model that describes both the emergence of community structure and the evolution of the internal structure of communities in growing social networks. The model comprises two complementary mechanisms: One mechanism accounts for the evolution of the internal link structure of a single community, and the second mechanism coordinates the growth of multiple overlapping communities. The first mechanism is based on the assumption that each node establishes links with its neighbors and introduces new nodes to the community at different rates. We demonstrate that this simple mechanism gives rise to an effective maximal degree within communities. This observation is related to the anthropological theory known as Dunbar's number, i.e., the empirical observation of a maximal number of ties which an average individual can sustain within its social groups. The second mechanism is based on a recently proposed generalization of preferential attachment to community structure, appropriately called structural preferential attachment (SPA). The combination of these two mechanisms into a single model (SPA+) allows us to reproduce a number of the global statistics of real networks: The distribution of community sizes, of node memberships, and of degrees. The SPA+ model also predicts (a) three qualitative regimes for the degree distribution within overlapping communities and (b) strong correlations between the number of communities to which a node belongs and its number of connections within each community. We present empirical evidence that support our findings in real complex networks.

  19. Seasonal patterns in stream periphyton fatty acids and community benthic algal composition in six high quality headwater streams

    Science.gov (United States)

    Honeyfield, Dale C.; Maloney, Kelly O.

    2015-01-01

    Fatty acids are integral components of periphyton and differ among algal taxa. We examined seasonal patterns in periphyton fatty acids in six minimally disturbed headwater streams in Pennsylvania’s Appalachian Mountains, USA. Environmental data and periphyton were collected across four seasons for fatty acid and algal taxa content. Non-metric multidimensional scaling ordination suggested significant seasonal differences in fatty acids; an ordination on algal composition revealed similar seasonal patterns, but with slightly weaker separation of summer and fall. Summer and fall fatty acid profiles were driven by temperature, overstory cover, and conductivity and winter profiles by measures of stream size. Ordination on algal composition suggested that summer and fall communities were driven by overstory and temperature, whereas winter communities were driven by velocity. The physiologically important fatty acid 18:3ω6 was highest in summer and fall. Winter samples had the highest 20:3ω3. Six saturated fatty acids differed among the seasons. Periphyton fatty acids profiles appeared to reflect benthic algal species composition. This suggests that periphyton fatty acid composition can be useful in characterizing basal food resources and stream water quality.

  20. Effect of lake water on algal biomass and microbial community structure in municipal wastewater-based lab-scale photobioreactors.

    Science.gov (United States)

    Krustok, I; Truu, J; Odlare, M; Truu, M; Ligi, T; Tiirik, K; Nehrenheim, E

    2015-08-01

    Photobioreactors are a novel environmental technology that can produce biofuels with the simultaneous removal of nutrients and pollutants from wastewaters. The aim of this study was to evaluate the effect of lake water inoculation on the production of algal biomass and phylogenetic and functional structure of the algal and bacterial communities in municipal wastewater-treating lab-scale photobioreactors. Inoculating the reactors with lake water had a significant benefit to the overall algal biomass growth and nutrient reduction in the reactors with wastewater and lake water (ratio 70/30 v/v). The metagenome-based survey showed that the most abundant algal phylum in these reactors was Chlorophyta with Scenedesmus being the most prominent genus. The most abundant bacterial phyla were Proteobacteria and Bacteroidetes with most dominant families being Sphingobacteriaceae, Cytophagaceae, Flavobacteriaceae, Comamonadaceae, Planctomycetaceae, Nocardiaceae and Nostocaceae. These photobioreactors were also effective in reducing the overall amount of pathogens in wastewater compared to reactors with wastewater/tap water mixture. Functional analysis of the photobioreactor metagenomes revealed an increase in relative abundance genes related to photosynthesis, synthesis of vitamins important for auxotrophic algae and decrease in virulence and nitrogen metabolism subsystems in lake water reactors. The results of the study indicate that adding lake water to the wastewater-based photobioreactor leads to an altered bacterial community phylogenetic and functional structure that could be linked to higher algal biomass production, as well as to enhanced nutrient and pathogen reduction in these reactors.

  1. Impacts of algal blooms removal by chitosan-modified soils on zooplankton community in Taihu Lake,China

    Institute of Scientific and Technical Information of China (English)

    Jiajia Ni; Yuhe Yu; Weisong Feng; Qingyun Yan; Gang pan; Bo Yang; Xiang Zhang; Xuemei Li

    2010-01-01

    It is important to assess the effect on zooplankton when perform the environmental protection or restoration technology,especially removing algal blooms,because algae were the major primary producer in algal lakes.The influence on zooplankton community after half a year of algal blooms removed by chitosan-modified soils in Taihu Lake was assessed and the rationality of carrying out the process semiannually was evaluated in the present study.Morphological composition and genetic diversity of zooplankton community were investigated by microscope checkup and polymerase chain reaction-denatured gradient gel electrophoresis (PCR-DGGE).A total of 44 zooplankton taxa (23 protozoa,17 rotifers,3 copepoda and 1 cladocera) were detected by microscope checkup,and a total of 91 bands (28 bands amplified by primers F1427-GC and R1616,63 bands amplified by primers Fung-G-C and NS1) were detected by PCR-DGGE.The results of cluster analysis or detrended correspondence analysis indicated that there was no considerable difference in morphological composition of zooplankton and DGGE profiles between experimental and control sites,and DGGE profiles could represent the biologic diversity.The study showed that zooplankton community could recover original condition after half year of algal blooms removed by chitosan-modified soils and it was acceptable to apply this process semiannually.In addition,the results revealed that PCR-DGGE could be applied to investigate the impacts of the environmental protection or restoration engineering on zooplankton community diversity.

  2. A mine of information: Benthic algal communities as biomonitors of metal contamination from abandoned tailings

    Energy Technology Data Exchange (ETDEWEB)

    Lavoie, Isabelle; Lavoie, Michel; Fortin, Claude, E-mail: fortincl@ete.inrs.ca

    2012-05-15

    Various biomonitoring approaches were tested in the field to assess the response of natural periphythic algal communities to chronic metal contamination downstream from an abandoned mine tailings site. The accumulation of cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) as well as the production of phytochelatins, the presence of diatom taxa known to tolerate high metal concentrations, diatom diversity and the presence of teratologies were determined. We observed highly significant relationships between intracellular metal and calculated free metal ion concentrations. Such relationships are often observed in laboratory studies but have been rarely validated in field studies. These results suggest that the concentration of metal inside the field-collected periphyton, regardless of its species composition, is a good indicator of exposure and is an interesting proxy for bioavailable metal concentrations in natural waters. The presence of teratologies and metal-tolerant taxa at our contaminated sites provided a clear indication that diatom communities were responding to this metal stress. A multi-metric approach integrating various bioassessment methods could be used for the field monitoring of metal contamination and the quantification of its effects. Highlights: Black-Right-Pointing-Pointer Various approaches for metal contamination biomonitoring were used in the field. Black-Right-Pointing-Pointer Metal accumulation in periphyton is correlated to free ion concentration. Black-Right-Pointing-Pointer Teratologies and metal-tolerant taxa provided a clear indication of metal stress. Black-Right-Pointing-Pointer Stream periphyton shows great potential as a biomonitor of metal contamination.

  3. Carbon conversion efficiency and population dynamics of a marine algae–bacteria consortium growing on simplified synthetic digestate: First step in a bioprocess coupling algal production and anaerobic digestion

    OpenAIRE

    Vasseur, C.; Bougaran, G.; Garnier, M.; Hamelin, J.; Leboulanger, Christophe; Le Chevanton, M.; Mostajir, B; Sialve, B.; Steyer, J. P.; Fouilland, E.

    2012-01-01

    Association of microalgae culture and anaerobic digestion seems a promising technology for sustainable algal biomass and biogas production. The use of digestates for sustaining the growth of microalgae reduces the costs and the environmental impacts associated with the substantial algal nutrient requirements. A natural marine algae–bacteria consortium was selected by growing on a medium containing macro nutrients (ammonia, phosphate and acetate) specific of a digestate, and was submitted to a...

  4. Influence of Diadema antillarum populations (Echinodermata: Diadematidae) on algal community structure in Jardines de la Reina, Cuba.

    Science.gov (United States)

    Martín Blanco, Félix; Clero Alonso, Lídice; González Sansón, Gaspar; Amargós Fabián, Pina

    2011-09-01

    The 1983-1984 mass mortality of Diadema antillarum produced severe damages on Caribbean reefs contributing to substantial changes in community structure that still persist. Despite the importance of Diadema grazing in structuring coral reefs, available information on current abundances and algal-urchin interactions in Cuba is scarce. We analyzed spatial variations in Diadema abundance and its influence on algal community structure in 22 reef sites in Jardines de la Reina, in June/2004 and April/2005. Urchins were counted in five 30 x 2m transects per site, and algal coverage was estimated in randomly located 0.25m side quadrats (15 per site). Abundances of Diadema were higher at reef crests (0.013-1.553 ind/m2), while reef slope populations showed values up to three orders of magnitude lower and were overgrown by macroalgae (up to 87%, local values). Algal community structure at reef slopes were dominated by macroalgae, especially Dictyota, Lobophora and Halimeda while the most abundant macroalgae at reef crests were Halimeda and Amphiroa. Urchin densities were negatively and positively correlated with mean coverage of macroalgae and crustose coralline algae, respectively, when analyzing data pooled across all sites, but not with data from separate habitats (specially reef crest), suggesting, along with historical fish biomass, that shallow reef community structure is being shaped by the synergistic action of other factors (e.g. fish grazing) rather than the influence of Diadema alone. However, we observed clear signs of Diadema grazing at reef crests and decreased macroalgal cover according to 2001 data, what suggest that grazing intensity at this habitat increased at the same time that Diadema recruitment began to be noticeable. Furthermore, the excessive abundance of macroalgae at reef slopes and the scarcity of crustose coralline algae seems to be due by the almost complete absence of D. antillarum at mid depth reefs, where local densities of this urchin were

  5. Biological oxygen demand optode analysis of coral reef-associated microbial communities exposed to algal exudates

    Directory of Open Access Journals (Sweden)

    AK Gregg

    2013-07-01

    Full Text Available Algae-derived dissolved organic matter has been hypothesized to induce mortality of reef building corals. One proposed killing mechanism is a zone of hypoxia created by rapidly growing microbes. To investigate this hypothesis, biological oxygen demand (BOD optodes were used to quantify the change in oxygen concentrations of microbial communities following exposure to exudates generated by turf algae and crustose coralline algae (CCA. BOD optodes were embedded with microbial communities cultured from Montastraea annularis and Mussismilia hispida, and respiration was measured during exposure to turf and CCA exudates. The oxygen concentrations along the optodes were visualized with a low-cost Submersible Oxygen Optode Recorder (SOOpR system. With this system we observed that exposure to exudates derived from turf algae stimulated higher oxygen drawdown by the coral-associated bacteria than CCA exudates or seawater controls. Furthermore, in both turf and CCA exudate treatments, all microbial communities (coral-, algae-associated and pelagic contributed significantly to the observed oxygen drawdown. This suggests that the driving factor for elevated oxygen consumption rates is the source of exudates rather than the initially introduced microbial community. Our results demonstrate that exudates from turf algae may contribute to hypoxia-induced coral stress in two different coral genera as a result of increased biological oxygen demand of the local microbial community. Additionally, the SOOpR system developed here can be applied to measure the BOD of any culturable microbe or microbial community.

  6. From benchtop to raceway : spectroscopic signatures of dynamic biological processes in algal communities.

    Energy Technology Data Exchange (ETDEWEB)

    Trahan, Christine Alexandra; Garcia, Omar Fidel; Martino, Anthony A.; Raymer, Michelle; Collins, Aaron M.; Hanson, David T. (University of New Mexico, Albuquerque, NM); Turner, Tom (University of New Mexico, Albuquerque, NM); Powell, Amy Jo; James, Scott Carlton (Sandia National Laboratories, Livermore, CA); Timlin, Jerilyn Ann; Scholle, Steven (University of New Mexico, Albuquerque, NM); Dwyer, Brian P.; Ruffing, Anne; Jones, Howland D. T.; Ricken, James Bryce; Reichardt, Thomas A. (Sandia National Laboratories, Livermore, CA)

    2010-08-01

    The search is on for new renewable energy and algal-derived biofuel is a critical piece in the multi-faceted renewable energy puzzle. It has 30x more oil than any terrestrial oilseed crop, ideal composition for biodiesel, no competition with food crops, can be grown in waste water, and is cleaner than petroleum based fuels. This project discusses these three goals: (1) Conduct fundamental research into the effects that dynamic biotic and abiotic stressors have on algal growth and lipid production - Genomics/Transcriptomics, Bioanalytical spectroscopy/Chemical imaging; (2) Discover spectral signatures for algal health at the benchtop and greenhouse scale - Remote sensing, Bioanalytical spectroscopy; and (3) Develop computational model for algal growth and productivity at the raceway scale - Computational modeling.

  7. Algal growth and community structure in a mixed-culture system using coal seam gas water as the water source.

    Science.gov (United States)

    Buchanan, Jessica J; Slater, Frances R; Bai, Xue; Pratt, Steven

    2013-01-01

    Coal seam gas (CSG) is being touted as a transition fuel as the world moves towards low-carbon economies. However, the development of CSG reserves will generate enormous volumes of saline water. In this work, we investigate the potential of using this saline water to support mass algae production. Water and brine from a CSG water treatment facility (1.6 and 11.6 g total dissolved solids per litre (TDS L(-1)) respectively) were inoculated with algal biomass from freshwater and seawater environments and supplemented with nutrients in open, fed-batch reactors. Significant algal growth was recorded, with maximum specific growth rates in CSG water and CSG brine of 0.20 +/- 0.05 d(-1) and 0.26 +/- 0.04 d(-1) respectively. These maximum specific growth rates were equal to or greater than specific growth rates in deionized water and seawater diluted to the same salinity. However, algal growth lag time in CSG brine was between 7 and 9 times longer than in other waters. Microscopy and terminal-restriction fragment length polymorphism (T-RFLP) were used to monitor community structure in the reactors. The same few algal species dominated all of the reactors, except for the CSG brine reactor at day 15. This result indicates that conditions in CSG brine select for different species of algae compared to seawater of the same salinity and other waters tested. The findings suggest that mass algae production in CSG water is feasible but algae community composition may be a function of CSG water chemistry. This has implications for the downstream use of algae.

  8. Field and laboratory guide to freshwater cyanobacteria harmful algal blooms for Native American and Alaska Native communities

    Science.gov (United States)

    Rosen, Barry H.; Ann St. Amand,

    2015-09-14

    Cyanobacteria can produce toxins and form harmful algal blooms. The Native American and Alaska Native communities that are dependent on subsistence fishing have an increased risk of exposure to these cyanotoxins. It is important to recognize the presence of an algal bloom in a waterbody and to distinguish a potentially toxic harmful algal bloom from a non-toxic bloom. This guide provides field images that show cyanobacteria blooms, some of which can be toxin producers, as well as other non-toxic algae blooms and floating plants that might be confused with algae. After recognition of a potential toxin-producing cyanobacterial bloom in the field, the type(s) of cyanobacteria present needs to be identified. Species identification, which requires microscopic examination, may help distinguish a toxin-producer from a non-toxin producer. This guide also provides microscopic images of the common cyanobacteria that are known to produce toxins, as well as images of algae that form blooms but do not produce toxins.

  9. Plankton communities and summertime declines in algal abundance associated with low dissolved oxygen in the Tualatin River, Oregon

    Science.gov (United States)

    Carpenter, Kurt D.; Rounds, Stewart A.

    2013-01-01

    and water-quality sample data from 2006 to 2008 were combined with parts of a larger discrete-sample and continuous water-quality monitoring dataset and examined to identify patterns in water-quality and algal conditions since 1991, with a particular emphasis on 2003–08. Longitudinal plankton surveys were conducted in 2006–08 at six sites between river miles (RM) 24.5 and 3.4 at 2- to 3-week intervals, or 5–6 per season, and in-situ bioassay experiments were conducted in 2008 to examine the potential effects of wastewater treatment facility (WWTF) effluent and phosphorus additions on phytoplankton biomass and algal photosynthesis. Phytoplankton and zooplankton community composition, streamflow, and water-quality data were analyzed using multivariate statistical techniques to gain insights into plankton dynamics to determine what factors might be most tied to the abundance and characteristics of the phytoplankton assemblages, and identify possible causes of their declines. The connection between low-DO events and algal declines was clearly evident, as bloom crashes were nearly always followed by periods of low DO. Algal blooms occurred each year during 2006–08, producing maximum chlorophyll-a (Chl-a) values in June or July generally in the range of 50–80 micrograms per liter (µg/L). Bloom crashes and absence of sufficient algal photosynthesis in mid- to late-summer contributed to minimum DO concentrations that were less than the State standard of 6.5 milligrams per liter (mg/L) based on the 30-day mean daily concentration, for 62–74 days each year. At times, the absolute minimum State standard (4 mg/L DO) also was not met. To learn more about why low-DO events occurred, specific algal declines during 2003–08 were scrutinized to determine their likely causal factors. From this information, a series of hypotheses were formulated and evaluated in terms of their ability to explain recent declines in algal populations in the river in late summer

  10. Growing urban health: community gardening in South-East Toronto.

    Science.gov (United States)

    Wakefield, Sarah; Yeudall, Fiona; Taron, Carolin; Reynolds, Jennifer; Skinner, Ana

    2007-06-01

    This article describes results from an investigation of the health impacts of community gardening, using Toronto, Ontario as a case study. According to community members and local service organizations, these gardens have a number of positive health benefits. However, few studies have explicitly focused on the health impacts of community gardens, and many of those did not ask community gardeners directly about their experiences in community gardening. This article sets out to fill this gap by describing the results of a community-based research project that collected data on the perceived health impacts of community gardening through participant observation, focus groups and in-depth interviews. Results suggest that community gardens were perceived by gardeners to provide numerous health benefits, including improved access to food, improved nutrition, increased physical activity and improved mental health. Community gardens were also seen to promote social health and community cohesion. These benefits were set against a backdrop of insecure land tenure and access, bureaucratic resistance, concerns about soil contamination and a lack of awareness and understanding by community members and decision-makers. Results also highlight the need for ongoing resources to support gardens in these many roles.

  11. Algal and Cyanobacterial communities in two rivers of the province of San Luis (Argentina subjected to anthropogenic influence

    Directory of Open Access Journals (Sweden)

    Jorgelina Daruich

    2013-03-01

    Full Text Available AIM: The use of biological indicators of pollution has increased in recent years as an alternative to the monitoring of water quality. Phytoplankton community selectively respond to different anthropogenic disturbances, such as water dams and the increase of nutrients coming from city centers, which leads to the eutrophication of the aquatic environment. The objective of this work was to evaluate the composition and the structure of the algal and Cyanobacterial communities in order to prove human influences by the presence of reservoirs with some degree of eutrophication and the impact of urbanization in two rivers at the Bebedero basin in San Luis province (Argentine. METHODS: Four sites were sampled: two of them were placed before dams and villages (V1 and (P1 and two after them (V2 and (P2. Each site was visited in every season of the year: summer, autumn, winter and spring. Qualitative and semi-quantitative phytoplankton samples were taken, and the frequency of occurrence was determined. Variations between pairs of sampling stations were analyzed through the Jaccard similarity and complementarity indices. RESULTS: Ninety two taxa were identified, of which diatoms were the most frequent. The most affected station was P2 with high abundance, less diversity and equitability, whereas the species more tolerant to the presence of organic matter were Melosira varians, Navicula tripunctata, Oscillatoria limosa, Gomphonema parvulum and Coelastrum microporum, and some species of euglenophytas. CONCLUSION: Therefore, the structure and composition of the algal and Cyanobacterial communities allowed us to identify sections more sensitive to human-induced alterations.

  12. Growing Community Capacity in Energy Development through Extension Education

    Science.gov (United States)

    Romich, Eric; Bowen-Elzey, Nancy

    2013-01-01

    New energy policy, industry regulation, and market investment are influencing the development of renewable energy technologies, setting the stage for rural America to provide the energy of tomorrow. This article describes how Extension's renewable energy programming was implemented in two Ohio communities to engage elected officials and residents…

  13. Algal biofuels.

    Science.gov (United States)

    Razeghifard, Reza

    2013-11-01

    The world is facing energy crisis and environmental issues due to the depletion of fossil fuels and increasing CO2 concentration in the atmosphere. Growing microalgae can contribute to practical solutions for these global problems because they can harvest solar energy and capture CO2 by converting it into biofuel using photosynthesis. Microalgae are robust organisms capable of rapid growth under a variety of conditions including in open ponds or closed photobioreactors. Their reduced biomass compounds can be used as the feedstock for mass production of a variety of biofuels. As another advantage, their ability to accumulate or secrete biofuels can be controlled by changing their growth conditions or metabolic engineering. This review is aimed to highlight different forms of biofuels produced by microalgae and the approaches taken to improve their biofuel productivity. The costs for industrial-scale production of algal biofuels in open ponds or closed photobioreactors are analyzed. Different strategies for photoproduction of hydrogen by the hydrogenase enzyme of green algae are discussed. Algae are also good sources of biodiesel since some species can make large quantities of lipids as their biomass. The lipid contents for some of the best oil-producing strains of algae in optimized growth conditions are reviewed. The potential of microalgae for producing petroleum related chemicals or ready-make fuels such as bioethanol, triterpenic hydrocarbons, isobutyraldehyde, isobutanol, and isoprene from their biomass are also presented.

  14. A community change in the algal endosymbionts of a scleractinian coral following a natural bleaching event: field evidence of acclimatization.

    Science.gov (United States)

    Jones, A M; Berkelmans, R; van Oppen, M J H; Mieog, J C; Sinclair, W

    2008-06-22

    The symbiosis between reef-building corals and their algal endosymbionts (zooxanthellae of the genus Symbiodinium) is highly sensitive to temperature stress, which makes coral reefs vulnerable to climate change. Thermal tolerance in corals is known to be substantially linked to the type of zooxanthellae they harbour and, when multiple types are present, the relative abundance of types can be experimentally manipulated to increase the thermal limits of individual corals. Although the potential exists for this to translate into substantial thermal acclimatization of coral communities, to date there is no evidence to show that this takes place under natural conditions. In this study, we show field evidence of a dramatic change in the symbiont community of Acropora millepora, a common and widespread Indo-Pacific hard coral species, after a natural bleaching event in early 2006 in the Keppel Islands (Great Barrier Reef). Before bleaching, 93.5% (n=460) of the randomly sampled and tagged colonies predominantly harboured the thermally sensitive Symbiodinium type C2, while the remainder harboured a tolerant Symbiodinium type belonging to clade D or mixtures of C2 and D. After bleaching, 71% of the surviving tagged colonies that were initially C2 predominant changed to D or C1 predominance. Colonies that were originally C2 predominant suffered high mortality (37%) compared with D-predominant colonies (8%). We estimate that just over 18% of the original A. millepora population survived unchanged leaving 29% of the population C2 and 71% D or C1 predominant six months after the bleaching event. This change in the symbiont community structure, while it persists, is likely to have substantially increased the thermal tolerance of this coral population. Understanding the processes that underpin the temporal changes in symbiont communities is key to assessing the acclimatization potential of reef corals.

  15. Biological oxygen demand optode analysis of coral reef-associated microbial communities exposed to algal exudates

    NARCIS (Netherlands)

    Gregg, A.K.; Hatay, M.; Haas, A.F.; Robinett, N.L.; Barott, K.; Vermeij, M.J.A.; Marhaver, K.; Thompson, F.; Meirelles, P.; Rohwer, F.

    2013-01-01

    Algae-derived dissolved organic matter has been hypothesized to induce mortality of reef building corals. One proposed killing mechanism is a zone of hypoxia created by rapidly growing microbes. To investigate this hypothesis, biological oxygen demand (BOD) optodes were used to quantify the change i

  16. A growing opportunity: Community gardens affiliated with US hospitals and academic health centers

    OpenAIRE

    George, Daniel R.; Rovniak, Liza S.; Kraschnewski, Jennifer L.; Ryan Hanson; Sciamanna, Christopher N

    2015-01-01

    Background: Community gardens can reduce public health disparities through promoting physical activity and healthy eating, growing food for underserved populations, and accelerating healing from injury or disease. Despite their potential to contribute to comprehensive patient care, no prior studies have investigated the prevalence of community gardens affiliated with US healthcare institutions, and the demographic characteristics of communities served by these gardens. Methods: In 2013, na...

  17. [Algal community structure and water quality assessment on drawdown area of Kaixian waters in Three Gorges Reservoir during winter storage period].

    Science.gov (United States)

    Guo, Jing-Song; Xie, Dan; Li, Zhe; Chen, Yuan; Sun, Zhi-Yu; Chen, Yong-Bo; Long, Man

    2012-04-01

    The old town area of Kaixian county was flooded and showed reservoir characteristics after the water level of Three Gorges Reservoir got 172. 8 m in December 2008. The aquatic ecology and nutritional status of Kaixian drawdown area after water storage are still rarely reported. To understand the current water environment and changes in algal community structure of Kaixian drawdown area after 172.8 m water level, the algal composition, abundance, biomass distribution and changes of its sampling spots including Hanfeng Lake were observed twice during winter storage period in January and December 2009. The trends in phytoplankton community structure were analyzed and the water quality assessment of nutritional status was carried out. The results indicated that 6 phylums, 37 genera, 69 species of phytoplankton in total were identified in the two sampling, and the dominant species were Dinophyta and Cryptophyta. The cell density and biomass in December 2009 were lower than those in January 2009. The evaluation results of algal population structure and pollution indicators showed that the nutrition level of Kaixian drawdown area during the winter storage period was mesotrophic to eutrophic type, while diversity analysis result indicated moderate pollution.

  18. Photosynthetic carbon incorporation and turnover in Antarctic cryptoendolithic microbial communities: Are they the slowest-growing communities on earth

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, C.G.; Vestal, J.R. (Univ. of Cincinnati, OH (USA))

    1991-08-01

    The main forms of terrestrial life in the cold, desolate Ross Desert of Antarctica are lichen-dominated or cyanobacterium-dominated cryptoendolithic (hidden in rock) microbial communities. Though microbial community biomass (as measured by extractable lipid phosphate) was well within the range of values determined for their microbial communities, community lipid carbon turnover times (calculated from community lipid biomass, rates of community photosynthetic carbon incorporation into lipids versus temperature, and the in situ temperature record) were among the longest on Earth (ca. 20,000 years). When the temperature is above freezing and moisture is present, moderate rates of photosynthesis can be measured. Lichen communities had a psychrophilic temperature response (maximal rate of 4.5 ng of C h{sup {minus}1}m{sup {minus}2} at 10C) while cyanobacteria communities had maximal rates at 20 to 30C(3 ng of C h{sup {minus}1} m{sup {minus}2}). These extraordinarily slowly growing communities were not nutrient limited. No significant changes in photosynthetic metabolism simple, tenacious microbial communities demonstrate strategies of survival under conditions normally considered too extreme for life.

  19. Iranian Critical ELT: A Belated but Growing Intellectual Shift in Iranian ELT Community

    Science.gov (United States)

    Aghagolzadeh, Ferdows; Davari, Hossein

    2014-01-01

    Reviewing and discussing the development of critical studies in the field of applied linguistics in general and English language teaching (ELT) in particular in Iran, this paper attempts to highlight the main contributions in this field. Introducing a new growing critical-oriented shift in Iranian ELT community as the one which has been mostly…

  20. Identifying the core microbial community in the gut of fungus-growing termites

    DEFF Research Database (Denmark)

    Otan, Saria; Mikaelyan, Aram; Nobre, Tânia

    2014-01-01

    with specific termite genus-level ecological niches. Finally, we show that gut communities of fungus-growing termites are similar to cockroaches, both at the bacterial phylum level and in a comparison of the core Macrotermitinae taxa abundances with representative cockroach, lower termite, and higher non...

  1. Change in algal symbiont communities after bleaching, not prior heat exposure, increases heat tolerance of reef corals.

    Science.gov (United States)

    Silverstein, Rachel N; Cunning, Ross; Baker, Andrew C

    2015-01-01

    Mutualistic organisms can be particularly susceptible to climate change stress, as their survivorship is often limited by the most vulnerable partner. However, symbiotic plasticity can also help organisms in changing environments by expanding their realized niche space. Coral-algal (Symbiodinium spp.) symbiosis exemplifies this dichotomy: the partnership is highly susceptible to 'bleaching' (stress-induced symbiosis breakdown), but stress-tolerant symbionts can also sometimes mitigate bleaching. Here, we investigate the role of diverse and mutable symbiotic partnerships in increasing corals' ability to thrive in high temperature conditions. We conducted repeat bleaching and recovery experiments on the coral Montastraea cavernosa, and used quantitative PCR and chlorophyll fluorometry to assess the structure and function of Symbiodinium communities within coral hosts. During an initial heat exposure (32 °C for 10 days), corals hosting only stress-sensitive symbionts (Symbiodinium C3) bleached, but recovered (at either 24 °C or 29 °C) with predominantly (>90%) stress-tolerant symbionts (Symbiodinium D1a), which were not detected before bleaching (either due to absence or extreme low abundance). When a second heat stress (also 32 °C for 10 days) was applied 3 months later, corals that previously bleached and were now dominated by D1a Symbiodinium experienced less photodamage and symbiont loss compared to control corals that had not been previously bleached, and were therefore still dominated by Symbiodinium C3. Additional corals that were initially bleached without heat by a herbicide (DCMU, at 24 °C) also recovered predominantly with D1a symbionts, and similarly lost fewer symbionts during subsequent thermal stress. Increased thermotolerance was also not observed in C3-dominated corals that were acclimated for 3 months to warmer temperatures (29 °C) before heat stress. These findings indicate that increased thermotolerance post-bleaching resulted from

  2. Emergence of Algal Blooms: The Effects of Short-Term Variability in Water Quality on Phytoplankton Abundance, Diversity, and Community Composition in a Tidal Estuary

    Directory of Open Access Journals (Sweden)

    Todd A. Egerton

    2014-01-01

    Full Text Available Algal blooms are dynamic phenomena, often attributed to environmental parameters that vary on short timescales (e.g., hours to days. Phytoplankton monitoring programs are largely designed to examine long-term trends and interannual variability. In order to better understand and evaluate the relationships between water quality variables and the genesis of algal blooms, daily samples were collected over a 34 day period in the eutrophic Lafayette River, a tidal tributary within Chesapeake Bay’s estuarine complex, during spring 2006. During this period two distinct algal blooms occurred; the first was a cryptomonad bloom and this was followed by a bloom of the mixotrophic dinoflagellate, Gymnodinium instriatum. Chlorophyll a, nutrient concentrations, and physical and chemical parameters were measured daily along with phytoplankton abundance and community composition. While 65 phytoplankton species from eight major taxonomic groups were identified in samples and total micro- and nano-phytoplankton cell densities ranged from 5.8 × 106 to 7.8 × 107 cells L−1, during blooms, cryptomonads and G. instriatum were 91.6% and 99.0%, respectively, of the total phytoplankton biomass during blooms. The cryptomonad bloom developed following a period of rainfall and concomitant increases in inorganic nitrogen concentrations. Nitrate, nitrite and ammonium concentrations 0 to 5 days prior were positively lag-correlated with cryptomonad abundance. In contrast, the G. insriatum bloom developed during periods of low dissolved nitrogen concentrations and their abundance was negatively correlated with inorganic nitrogen concentrations.

  3. Species composition and structure of a photophilic algal community dominated by Halopteris scoparia (L. Sauvageau from the North-Western Mediterranean

    Directory of Open Access Journals (Sweden)

    Ballesteros, Enric

    1993-12-01

    Full Text Available A photophilic agal community dominated by Halopteris scoparia and other brown algae is described from sheltered environments from the North-Western Mediterranean rocky bottoms. This community is included in the Padino-Cladostephetum hirsutae previously described by FELDMANN(1937 for the same geographical area. This plant association is characterized by the lack of an upper erect stratum of Fucales and by the low degree of presence of thermophilic species which typify other similar communities described from other Mediterranean areas. Algal biomass ranges from 1100 to 2500 g dw m-2 and coverage percentage ranges from 250 to 450 %. The great miniaturization and the extraordinary diversity and species richness of Mediterranean photophilic algal communities is assessed. Although there is not a clear seasonal change in biomass of the dominant species in the community, two structural stages can be discerned along an annual cycle: a developed community (summer and a diversified community (winter. Finally, the community structure and the environmental factors that impinge upon it are compared with those found in other Mediterranean phytobenthic communities.

    Se describe una comunidad de algas fotófilas mediterráneas de modo calmado dominada por Hatopteris scoparia y otros feófitos de porte mediano, la cual se adscribe a la asociación Padino-Clodostephetum hirsutae J. Feldmann 1937. Dicha asociación se caracteriza por la ausencia de un estrato elevado de Fucales y el escaso grado de presencia de especies termófilas propia de comunidades similares descritas de otras zonas del Mediterráneo. La biomasa algal oscila entre 1100 y 2500 g ps m-2 mientras que el porcentaje de recubrimiento varía entre el 250 y el 450%. Se pone de manifiesto la gran miniaturización de las comunidades de algas fotólitas mediterráneas y su extraordinaria diversidad y riqueza especificas. Pese a no existir un claro

  4. A community change in the algal endosymbionts of a scleractinian coral following a natural bleaching event : field evidence of acclimatization

    NARCIS (Netherlands)

    Jones, A. M.; Berkelmans, R.; van Oppen, M. J. H.; Mieog, J. C.; Sinclair, W.

    2008-01-01

    The symbiosis between reef-building corals and their algal endosymbionts (zooxanthellae of the genus Symbiodinium) is highly sensitive to temperature stress, which makes coral reefs vulnerable to climate change. Thermal tolerance in corals is known to be substantially linked to the type of zooxanthe

  5. Interactive effects of ocean acidification and warming on coral reef associated epilithic algal communities under past, present-day and future ocean conditions

    Science.gov (United States)

    Vogel, N.; Cantin, N. E.; Strahl, J.; Kaniewska, P.; Bay, L.; Wild, C.; Uthicke, S.

    2016-06-01

    Epilithic algal communities play critical ecological roles on coral reefs, but their response to individual and interactive effects of ocean warming (OW) and ocean acidification (OA) is still largely unknown. We investigated growth, photosynthesis and calcification of early epilithic algal community assemblages exposed for 6 months to four temperature profiles (-1.1, ±0.0, +0.9, +1.6 °C) that were crossed with four carbon dioxide partial pressure (pCO2) levels (360, 440, 650, 940 µatm), under flow-through conditions and natural light regimes. Additionally, we compared the cover of heavily calcified crustose coralline algae (CCA) and lightly calcified red algae of the genus Peyssonnelia among treatments. Increase in cover of epilithic communities showed optima under moderately elevated temperatures and present pCO2, while cover strongly decreased under high temperatures and high-pCO2 conditions, particularly due to decreasing cover of CCA. Similarly, community calcification rates were strongly decreased at high pCO2 under both measured temperatures. While final cover of CCA decreased under high temperature and pCO2 (additive negative effects), cover of Peyssonnelia spp. increased at high compared to annual average and moderately elevated temperatures. Thus, cover of Peyssonnelia spp. increased in treatment combinations with less CCA, which was supported by a significant negative correlation between organism groups. The different susceptibility to stressors most likely derived from a different calcification intensity and/or mineral. Notably, growth of the epilithic communities and final cover of CCA were strongly decreased under reduced-pCO2 conditions compared to the present. Thus, CCA may have acclimatized from past to present-day pCO2 conditions, and changes in carbonate chemistry, regardless in which direction, negatively affect them. However, if epilithic organisms cannot further acclimatize to OW and OA, the interacting effects of both factors may change

  6. Growing Local Value How to Build Business Partnerships That Strengthen Your Community

    CERN Document Server

    Hammel, Laury

    2007-01-01

    Hanna Andersson founder Gun Denhart and successful entrepreneur Laury Hammel show how every aspect of a business (from product creation to employee recruitment to vendor selection) holds the dual promise of bigger profits and a stronger local community. With practical tools and real-life examples of the best practitioners and techniques of values-driven business, "Growing Local Value" provides a framework for the full spectrum of ways in which a business can contribute to its community - and the benefits a company receives when it does so.

  7. Ecological Study of Periphytic Algal Community of Doodh Ganga and Khansha-Mansha Streams of Yusmarg Forests: A Health Resort of Kashmir Valley, India

    Directory of Open Access Journals (Sweden)

    Rafia Rashid

    2013-06-01

    Full Text Available The present study on Doodh Ganga and Khansha-Mansha streams of Yusmarg forests deals with the general ecological studies on periphytic algal community in terms of species composition and density. During the present investigation the periphytic algal community of Doodh Ganga and Khansha-Mansha streams were represented by 30 taxa which belonged to 4 major classes namely Bacillariophyceae (14, Chlorophyceae (11, Cyanophyceae (4 and Euglenophyceae (1. The most common periphytic species encountered across all the sites included Closterium sp., Zygnema sp., Amphora sp., Cymbella sp., Epithemia sp., Fragilaria sp., Navicula sp., Synedra sp., Tabellaria sp., Lyngbya sp. and Phormidium sp. Among the two streams, Doodh Ganga showed large number of taxa (45 and Khansha-Mansha was having 37 taxa of periphyton. Bacillariophyceae was the dominant group both in diversity and density and included 14 taxa contributing 57% of total periphytic algal population. Cyanophyceae forming the second dominant class was represented by 4 genera comprising 22% of the total periphytic algae .Chlorophyceae ranked third in its dominance pattern with 11 genera forming 20% of all the periphytic algae. Euglenophyceae was represented by only one species of Euglena sp. forming 1% of all the periphytic algae and found only at site 2 (Doodh Ganga downstream.Amongst the study sites the highest (5.69 value of Shannon Weiner Index was found at Doodh Ganga upstream while as lowest (4.38 at Khansha-Mansha downstream. The primary conclusion is that the streams, having crystal clear water, and are free from pollution as Chlorophyceae are better represented in both the streams. Further, as a result of less anthropogenic pressures the quality of water is fairly good.

  8. Effects of application of corn straw on soil microbial community structure during the maize growing season.

    Science.gov (United States)

    Lu, Ping; Lin, Yin-Hua; Yang, Zhong-Qi; Xu, Yan-Peng; Tan, Fei; Jia, Xu-Dong; Wang, Miao; Xu, De-Rong; Wang, Xi-Zhuo

    2015-01-01

    This study investigated the influence of corn straw application on soil microbial communities and the relationship between such communities and soil properties in black soil. The crop used in this study was maize (Zea mays L.). The five treatments consisted of applying a gradient (50, 100, 150, and 200%) of shattered corn straw residue to the soil. Soil samples were taken from May through September during the 2012 maize growing season. The microbial community structure was determined using phospholipid fatty acid (PLFA) analysis. Our results revealed that the application of corn straw influenced the soil properties and increased the soil organic carbon and total nitrogen. Applying corn straw to fields also influenced the variation in soil microbial biomass and community composition, which is consistent with the variations found in soil total nitrogen (TN) and soil respiration (SR). However, the soil carbon-to-nitrogen ratio had no effect on soil microbial communities. The abundance of PLFAs, TN, and SR was higher in C1.5 than those in other treatments, suggesting that the soil properties and soil microbial community composition were affected positively by the application of corn straw to black soil. A Principal Component Analysis indicated that soil microbial communities were different in the straw decomposition processes. Moreover, the soil microbial communities from C1.5 were significantly different from those of CK (p straw treatments that correlated with SR (p straw positively influences soil properties and soil microbial communities and that these properties affect these communities. The individual PLFA signatures were sensitive indicators that reflected the changes in the soil environment condition.

  9. Growing Right Onto Wellness (GROW): a family-centered, community-based obesity prevention randomized controlled trial for preschool child-parent pairs.

    Science.gov (United States)

    Po'e, Eli K; Heerman, William J; Mistry, Rishi S; Barkin, Shari L

    2013-11-01

    Growing Right Onto Wellness (GROW) is a randomized controlled trial that tests the efficacy of a family-centered, community-based, behavioral intervention to prevent childhood obesity among preschool-aged children. Focusing on parent-child pairs, GROW utilizes a multi-level framework, which accounts for macro (i.e., built-environment) and micro (i.e., genetics) level systems that contribute to the childhood obesity epidemic. Six hundred parent-child pairs will be randomized to a 3-year healthy lifestyle intervention or a 3-year school readiness program. Eligible children are enrolled between ages 3 and 5, are from minority communities, and are not obese. The principal site for the GROW intervention is local community recreation centers and libraries. The primary outcome is childhood body mass index (BMI) trajectory at the end of the three-year study period. In addition to other anthropometric measurements, mediators and moderators of growth are considered, including genetics, accelerometry, and diet recall. GROW is a staged intensity intervention, consisting of intensive, maintenance, and sustainability phases. Throughout the study, parents build skills in nutrition, physical activity, and parenting, concurrently forming new social networks. Participants are taught goal-setting, self-monitoring, and problem solving techniques to facilitate sustainable behavior change. The GROW curriculum uses low health literacy communication and social media to communicate key health messages. The control arm is administered to both control and intervention participants. By conducting this trial in public community centers, and by implementing a family-centered approach to sustainable healthy childhood growth, we aim to develop an exportable community-based intervention to address the expanding public health crisis of pediatric obesity.

  10. Microbial-algal community changes during the latest Permian ecological crisis: Evidence from lipid biomarkers at Cili, South China

    Science.gov (United States)

    Luo, Genming; Wang, Yongbiao; Grice, Kliti; Kershaw, Steve; Algeo, Thomas J.; Ruan, Xiaoyan; Yang, Hao; Jia, Chengling; Xie, Shucheng

    2013-06-01

    Microbialites flourished globally immediately following the latest Permian mass extinction. In this study, lipid biomarker records were analyzed in the Cili section (Hunan Province, South China) in order to determine the types of microbes involved in microbialite formation and their response to contemporaneous environmental changes. Various biomarkers were identified in the aliphatic and aromatic fractions using gas chromatography (GC) and GC-mass spectrometry (GC-MS). Low abundance of steranes in the microbialite layer suggests that it did not contain large amounts of algae, in striking contrast to the abundant algal fossils and algal-derived steranes present in the underlying (pre-crisis) skeletal limestone. Although pristine/phytane (Pr/Ph) ratios increased in the microbialite layer, covariation of Pr/Ph with the ratio of low- to high-molecular-weight n-alkanes (C20 -/C20 +) suggests that the former proxy was controlled by microbial (particularly cyanobacterial) inputs rather than by redox conditions. The microbialite also yielded low ratios of hopanes to short-chain n-alkanes (HP/Lalk) and high abundances of C21n-alkylcyclohexane, indicating that, in addition to cyanobacteria, anaerobic bacteria, archaea, and possibly acritarchs flourished in the aftermath of the marine extinction event. The upper part of the thinly bedded micritic limestone overlying the microbialite exhibits a bimodal distribution of n-alkanes as well as increased abundances of extended tricyclic terpanes and steranes, suggesting a return of habitable shallow-marine conditions for eukaryotic algae several hundred thousand years after the latest Permian mass extinction. Increases in the dibenzofuran ratio (i.e., DBF/(DBF + DBT + F)) and in the coronene to phenanthrene ratio (Cor/P) in the skeletal limestone immediately below the microbialite are evidence of enhanced soil erosion rates and wildfire intensity, marking the collapse of terrestrial ecosystems. The terrestrial crisis thus slightly

  11. Assessment of potential effects of water produced from coalbed natural gas development on macroinvertebrate and algal communities in the Powder River and Tongue River, Wyoming and Montana, 2010

    Science.gov (United States)

    Peterson, David A.; Hargett, Eric G.; Feldman, David L.

    2011-01-01

    Ongoing development of coalbed natural gas in the Powder River structural basin in Wyoming and Montana led to formation of an interagency aquatic task group to address concerns about the effects of the resulting production water on biological communities in streams of the area. Ecological assessments, made from 2005–08 under the direction of the task group, indicated biological condition of the macroinvertebrate and algal communities in the middle reaches of the Powder was lower than in the upper or lower reaches. On the basis of the 2005–08 results, sampling of the macroinvertebrate and algae communities was conducted at 18 sites on the mainstem Powder River and 6 sites on the mainstem Tongue River in 2010. Sampling-site locations were selected on a paired approach, with sites located upstream and downstream of discharge points and tributaries associated with coalbed natural gas development. Differences in biological condition among site pairs were evaluated graphically and statistically using multiple lines of evidence that included macroinvertebrate and algal community metrics (such as taxa richness, relative abundance, functional feeding groups, and tolerance) and output from observed/expected (O/E) macroinvertebrate models from Wyoming and Montana. Multiple lines of evidence indicated a decline in biological condition in the middle reaches of the Powder River, potentially indicating cumulative effects from coalbed natural gas discharges within one or more reaches between Flying E Creek and Wild Horse Creek in Wyoming. The maximum concentrations of alkalinity in the Powder River also occurred in the middle reaches. Biological condition in the upper and lower reaches of the Powder River was variable, with declines between some site pairs, such as upstream and downstream of Dry Fork and Willow Creek, and increases at others, such as upstream and downstream of Beaver Creek. Biological condition at site pairs on the Tongue River showed an increase in one case

  12. ALGAL RESPONSE TO NUTRIENT ENRICHMENT IN FORESTED OLIGOTROPHIC STREAM(1).

    Science.gov (United States)

    Veraart, Annelies J; Romaní, Anna M; Tornés, Elisabet; Sabater, Sergi

    2008-06-01

    Nutrient input in streams alters the density and species composition of attached algal communities in open systems. However, in forested streams, the light reaching the streambed (rather than the local nutrient levels) may limit the growth of these communities. A nutrient-enrichment experiment in a forested oligotrophic stream was performed to test the hypothesis that nutrient addition has only minor effects on the community composition of attached algae and cyanobacteria under light limitation. Moderate nutrient addition consisted of increasing basal phosphorus (P) concentrations 3-fold and basal nitrogen (N) concentrations 2-fold. Two upstream control reaches were compared to a downstream reach before and after nutrient addition. Nutrients were added continuously to the downstream reach for 1 year. Algal biofilms growing on ceramic tiles were sampled and identified for more than a year before nutrient addition to 12 months after. Diatoms were the most abundant taxonomic group in the three stream reaches. Nutrient enrichment caused significant variations in the composition of the diatom community. While some taxa showed significant decreases (e.g., Achnanthes minutissima, Gomphonema angustum), increases for other taxa (such as Rhoicosphenia abbreviata and Amphora ovalis) were detected in the enriched reach (for taxonomic authors, see Table 2). Epiphytic and adnate taxa of large size were enhanced, particularly during periods of favorable growth conditions (spring). Nutrients also caused a change in the algal chl a, which increased from 0.5-5.8 to 2.1-10.7 μg chl · cm(-2) . Our results indicate that in oligotrophic forested streams, long-term nutrient addition has significant effects on the algal biomass and community composition, which are detectable despite the low light availability caused by the tree canopy. Low light availability moderates but does not detain the long-term tendency toward a nutrient-tolerant community. Furthermore, the effects

  13. Mycorrhizal Fungal Community of Poplars Growing on Pyrite Tailings Contaminated Site near the River Timok

    Directory of Open Access Journals (Sweden)

    Marina Katanić

    2015-06-01

    Full Text Available Background and Purpose: Mycorrhizal fungi are of high importance for functioning of forest ecosystems and they could be used as indicators of environmental stress. The aim of this research was to analyze ectomycorrhizal community structure and to determine root colonization rate with ectomycorrhizal, arbuscular mycorrhizal and endophytic fungi of poplars growing on pyrite tailings contaminated site near the river Timok (Eastern Serbia. Materials and Methods: Identification of ectomycorrhizal types was performed by combining morphological and anatomical characterization of ectomycorrhizae with molecular identification approach, based on sequencing of the nuclear ITS rRNA region. Also, colonization of poplar roots with ectomycorrhizal, arbuscular mycorrhizal and dark septated endophytic fungi were analysed with intersection method. Results and Conclusions: Physico-chemical analyses of soil from studied site showed unfavourable water properties of soil, relatively low pH and high content of heavy metals (copper and zinc. In investigated samples only four different ectomycorrhizal fungi were found. To the species level were identified Thelephora terrestris and Tomentella ellisi, while two types remained unidentified. Type Thelephora terrestris made up 89% of all ectomycorrhizal roots on studied site. Consequently total values of Species richness index and Shannon-Weaver diversity index were 0.80 and 0.43, respectively. No structures of arbuscular mycorrhizal fungi were recorded. Unfavourable environmental conditions prevailing on investigated site caused decrease of ectomycorrhizal types diversity. Our findings point out that mycorrhyzal fungal community could be used as an appropriate indicator of environmental changes.

  14. Periphytic algal community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Paraná State, Brazil) = Comunidade de algas perifíticas em substrato artificial e natural em um tributário do reservatório de Rosana (Ribeirão do Corvo, Estado do Paraná, Brasil)

    OpenAIRE

    Liliana Rodrigues; Sirlene Aparecida Felisberto

    2010-01-01

    Periphytic algal community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Paraná State, Brazil). This study evaluated the heterogeneity in periphytic algal community, under the influence of time colonization on artificial substratum. We also examined which abiotic variables most influenced the community in natural and artificial substratum. Egeria najas Planchon was used as natural substratum, and a plastic plant, asartificial. This experiment was c...

  15. Macroinvertebrate and algal communities in an extremely acidic river and the Kawah Ijen crater lake (pH

    NARCIS (Netherlands)

    Löhr, A.J.; Sluik, R.; Olaveson, M.M.; Ivorra, N.; van Gestel, C.A.M.; van Straalen, N.M.

    2006-01-01

    Acidic aquatic ecosystems are mainly characterized by low pH and high concentrations of metals and other elements with evident effects on local community structure. Acidity effects on benthic communities in one of the world's largest extremely acidic crater lakes, the Kawah Ijen (East Java, Indonesi

  16. Sustainable Algal Energy Production and Environmental Remediation

    Energy Technology Data Exchange (ETDEWEB)

    Cooke, William E. [College of William and Mary, Williamsburg, VA (United States). Dept. of Physics

    2012-07-14

    Overall, our results confirm that wild algal species sequester a wide range of organic and metal contaminants and excess nutrients (PAHs, trace metals, and nutrients) from natural waters, and suggest parameters that could be useful in predicting uptake rates for algae growing on an algal floway or other algal growth systems in the environment or in industrial processes. The implication for various fuel production processes differ with the detailed unit operations involved, and these results will be of use in the developing of scaling experiments for various types of engineering process designs.

  17. Plants are less negatively affected by flooding when growing in species-rich plant communities.

    Science.gov (United States)

    Wright, Alexandra J; de Kroon, Hans; Visser, Eric J W; Buchmann, Tina; Ebeling, Anne; Eisenhauer, Nico; Fischer, Christine; Hildebrandt, Anke; Ravenek, Janneke; Roscher, Christiane; Weigelt, Alexandra; Weisser, Wolfgang; Voesenek, Laurentius A C J; Mommer, Liesje

    2017-01-01

    Flooding is expected to increase in frequency and severity in the future. The ecological consequences of flooding are the combined result of species-specific plant traits and ecological context. However, the majority of past flooding research has focused on individual model species under highly controlled conditions. An early summer flooding event in a grassland biodiversity experiment in Jena, Germany, provided the opportunity to assess flooding responses of 60 grassland species in monocultures and 16-species mixtures. We examined plant biomass, species-specific traits (plant height, specific leaf area (SLA), root aerenchyma, starch content) and soil porosity. We found that, on average, plant species were less negatively affected by the flood when grown in higher-diversity plots in July 2013. By September 2013, grasses were unaffected by the flood regardless of plant diversity, and legumes were severely negatively affected regardless of plant diversity. Plants with greater SLA and more root aerenchyma performed better in September. Soil porosity was higher in higher-diversity plots and had a positive effect on plant performance. As floods become more frequent and severe in the future, growing flood-sensitive plants in higher-diversity communities and in soil with greater soil aeration may attenuate the most negative effects of flooding.

  18. Wastewater treatment high rate algal ponds (WWT HRAP) for low-cost biofuel production.

    Science.gov (United States)

    Mehrabadi, Abbas; Craggs, Rupert; Farid, Mohammed M

    2015-05-01

    Growing energy demand and water consumption have increased concerns about energy security and efficient wastewater treatment and reuse. Wastewater treatment high rate algal ponds (WWT HRAPs) are a promising technology that could help solve these challenges concurrently where climate is favorable. WWT HRAPs have great potential for biofuel production as a by-product of WWT, since the costs of algal cultivation and harvest for biofuel production are covered by the wastewater treatment function. Generally, 800-1400 GJ/ha/year energy (average biomass energy content: 20 GJ/ton; HRAP biomass productivity: 40-70 tons/ha/year) can be produced in the form of harvestable biomass from WWT HRAP which can be used to provide community-level energy supply. In this paper the benefits of WWT HRAPs are compared with conventional mass algal culture systems. Moreover, parameters to effectively increase algal energy content and overall energy production from WWT HRAP are discussed including selection of appropriate algal biomass biofuel conversion pathways.

  19. Algal community composition and abundance near the confluence of the Jialing and Yangtze Rivers and in Shuanglong Lake in Chongqing, P.R.China

    Institute of Scientific and Technical Information of China (English)

    GUO Wei-hua; HE Dong-cai; LONG Tian-yu; LI Nan; DAI Ling-ling

    2008-01-01

    To understand the potential impact of the Three Gorges Reservoir on the aquatic ecosystem after the damming of the Yangtze River, we studied the community composition and temporal abundance distribution of algae in two types of water bodies:a segment of the Jialing River near its confluence with the Yangtze River as an example of the river-lake type, and Shuanglong Lake in Chongqing as an example of the lake type. In total, 107 species belonging to 58 genera of 7 phyla were identified in the study area of the Jialing River, dominated by three groups with 49.5% diatoms, 29.0% chlorophytes, and 11.4% cyanobacteria in the community composition. There were 122 species belonging to 66 genera of 8 phyla in Shuanglong Lake, dominated by the same three groups with 19.7% diatoms, 48.4% chlorophytes, and 22.2% cyanobacteria. The densities of total algae and individual dominant groups were all much higher in the lake. More species of diatoms were found in the river-lake segment; whereas more chlorophyte species and cyanobacteriaum species were in the lake. There were 17 dominant species including 8 diatoms, 4 chlorophytes, 3 cyanobacteria and 2 cryptophytes in the river-lake segment, and 21 species in the lake, including 2 diatoms, 9 chlorophytes, 6 cyanobacteria, 3 cryptophytes and a dinoflagellate. In eutrophic conditions, chlorophytes and cyanobacteria mayproliferate in a lake-type area and diatoms may cause algal bloom in a relatively faster-flow lake-river type area.

  20. Algal and fungal diversity in Antarctic lichens.

    Science.gov (United States)

    Park, Chae Haeng; Kim, Kyung Mo; Elvebakk, Arve; Kim, Ok-Sun; Jeong, Gajin; Hong, Soon Gyu

    2015-01-01

    The composition of lichen ecosystems except mycobiont and photobiont has not been evaluated intensively. In addition, recent studies to identify algal genotypes have raised questions about the specific relationship between mycobiont and photobiont. In the current study, we analyzed algal and fungal community structures in lichen species from King George Island, Antarctica, by pyrosequencing of eukaryotic large subunit (LSU) and algal internal transcribed spacer (ITS) domains of the nuclear rRNA gene. The sequencing results of LSU and ITS regions indicated that each lichen thallus contained diverse algal species. The major algal operational taxonomic unit (OTU) defined at a 99% similarity cutoff of LSU sequences accounted for 78.7-100% of the total algal community in each sample. In several cases, the major OTUs defined by LSU sequences were represented by two closely related OTUs defined by 98% sequence similarity of ITS domain. The results of LSU sequences indicated that lichen-associated fungi belonged to the Arthoniomycetes, Eurotiomycetes, Lecanoromycetes, Leotiomycetes, and Sordariomycetes of the Ascomycota, and Tremellomycetes and Cystobasidiomycetes of the Basidiomycota. The composition of major photobiont species and lichen-associated fungal community were mostly related to the mycobiont species. The contribution of growth forms or substrates on composition of photobiont and lichen-associated fungi was not evident.

  1. Characterization of the Kootenai River Algae Community and Primary Productivity Before and After Experimental Nutrient Addition, 2004–2007 [Chapter 2, Kootenai River Algal Community Characterization, 2009 KTOI REPORT].

    Energy Technology Data Exchange (ETDEWEB)

    Holderman, Charlie [Kootenai Tribe of Idaho; Bonners Ferry, ID; Anders, Paul [Cramer Fish Sciences; Moscow, ID; Shafii, Bahman [Statistical Consulting Services; Clarkston, WA

    2009-07-01

    The Kootenai River ecosystem (spelled Kootenay in Canada) has experienced numerous ecological changes since the early 1900s. Some of the largest impacts to habitat, biological communities, and ecological function resulted from levee construction along the 120 km of river upstream from Kootenay Lake, completed by the 1950s, and the construction and operation of Libby Dam on the river near Libby Montana, completed in 1972. Levee construction isolated tens of thousands of hectares of historic functioning floodplain habitat from the river channel downstream in Idaho and British Columbia (B.C.) severely reducing natural biological productivity and habitat diversity crucial to large river-floodplain ecosystem function. Libby Dam greatly reduces sediment and nutrient transport to downstream river reaches, and dam operations cause large changes in the timing, duration, and magnitude of river flows. These and other changes have contributed to the ecological collapse of the post-development Kootenai River ecosystem and its native biological communities. In response to large scale loss of nutrients, experimental nutrient addition was initiated in the North Arm of Kootenay Lake in 1992, in the South Arm of Kootenay Lake in 2004, and in the Kootenai River at the Idaho-Montana border during 2005. This report characterizes baseline chlorophyll concentration and accrual (primary productivity) rates and diatom and algal community composition and ecological metrics in the Kootenai River for four years, one (2004) before, and three (2005 through 2007) after nutrient addition. The study area encompassed a 325 km river reach from the upper Kootenay River at Wardner, B.C. (river kilometer (rkm) 445) downstream through Montana and Idaho to Kootenay Lake in B.C. (rkm 120). Sampling reaches included an unimpounded reach furthest upstream and four reaches downstream from Libby Dam affected by impoundment: two in the canyon reach (one with and one without nutrient addition), a braided reach

  2. Periphytic algal community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Paraná State, Brazil - doi: 10.4025/actascibiolsci.v32i4.4627 Periphytic algal community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Paraná State, Brazil - doi: 10.4025/actascibiolsci.v32i4.4627

    Directory of Open Access Journals (Sweden)

    Liliana Rodrigues

    2010-11-01

    Full Text Available Periphytic algal community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Paraná State, Brazil. This study evaluated the heterogeneity in periphytic algal community, under the influence of time colonization on artificial substratum. We also examined which abiotic variables most influenced the community in natural and artificial substratum. Egeria najas Planchon was used as natural substratum, and a plastic plant, as artificial. This experiment was carried out in a lateral arm from Rosana Reservoir, formed by Corvo Stream (Paranapanema river basin, in the period from November 21st to December 12nd, 2003, characterized as a warm and rainy period. Changes in species composition were assessed using the similarity indices. 495 taxa were registered in the phycoperiphytic community, distributed in 133 genera and 11 classes. Zygnemaphyceae, Bacillariophyceae, Chlorophyceae and Cyanophyceae presented higher species number, in both substrata. Staurodesmus, Closterium, Staurastrum and Cosmarium (Desmidiales; Gomphonema and Eunotia (Pennales; Characium, Scenedesmus and Desmodesmus (Chlorococcales; Anabaena and Aphanocapsa (Nostocales and Chroococcales, respectively were the most species-rich genera. The epiphytic community reached the highest species richness in the 15th successional day. Regardless the substratum type, the number of species was probably related to the high concentrations of nutrients (phosphorus and nitrogen.Periphytic algal community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Paraná State, Brazil. This study evaluated the heterogeneity in periphytic algal community, under the influence of time colonization on artificial substratum. We also examined which abiotic variables most influenced the community in natural and artificial substratum. Egeria najas Planchon was used as natural substratum, and a plastic plant, as artificial. This experiment was

  3. Environmental context shapes the bacterial community structure associated to Peltigera cyanolichens growing in Tierra del Fuego, Chile.

    Science.gov (United States)

    Ramírez-Fernández, Lía; Zúñiga, Catalina; Carú, Margarita; Orlando, Julieta

    2014-03-01

    The structure of the associated bacterial community of bipartite cyanolichens of the genus Peltigera from three different environmental contexts in the Karukinka Natural Park, Tierra del Fuego, Chile, was assessed. The sampling sites represent different habitat contexts: mature native forest, young native forest and grassland. Recently it has been determined that the bacterial community associated to lichens could be highly structured according to the mycobiont or photobiont identities, to the environmental context and/or to the geographic scale. However, there are some inconsistencies in defining which of these factors would be the most significant on determining the structure of the microbial communities associated with lichens, mainly because most studies compare the bacterial communities between different lichen species and/or with different photobiont types (algae vs. cyanobacteria). In this work bipartite lichens belonging to the same genus (Peltigera) symbiotically associated with cyanobacteria (Nostoc) were analyzed by TRFLP to determine the structure of the bacterial community intimately associated with the lichen thalli and the one present in the substrate where they grow. The results indicate that the bacterial community intimately associated differs from the one of the substrate, being the former more influenced by the environmental context where the lichen grows.

  4. Characterization of the Kootenai River Algae Community and Primary Productivity Before and After Experimental Nutrient Addition, 2004–2007 [Chapter 2, Kootenai River Algal Community Characterization, 2009 KTOI REPORT].

    Energy Technology Data Exchange (ETDEWEB)

    Holderman, Charlie [Kootenai Tribe of Idaho; Bonners Ferry, ID; Anders, Paul [Cramer Fish Sciences; Moscow, ID; Shafii, Bahman [Statistical Consulting Services; Clarkston, WA

    2009-07-01

    The Kootenai River ecosystem (spelled Kootenay in Canada) has experienced numerous ecological changes since the early 1900s. Some of the largest impacts to habitat, biological communities, and ecological function resulted from levee construction along the 120 km of river upstream from Kootenay Lake, completed by the 1950s, and the construction and operation of Libby Dam on the river near Libby Montana, completed in 1972. Levee construction isolated tens of thousands of hectares of historic functioning floodplain habitat from the river channel downstream in Idaho and British Columbia (B.C.) severely reducing natural biological productivity and habitat diversity crucial to large river-floodplain ecosystem function. Libby Dam greatly reduces sediment and nutrient transport to downstream river reaches, and dam operations cause large changes in the timing, duration, and magnitude of river flows. These and other changes have contributed to the ecological collapse of the post-development Kootenai River ecosystem and its native biological communities. In response to large scale loss of nutrients, experimental nutrient addition was initiated in the North Arm of Kootenay Lake in 1992, in the South Arm of Kootenay Lake in 2004, and in the Kootenai River at the Idaho-Montana border during 2005. This report characterizes baseline chlorophyll concentration and accrual (primary productivity) rates and diatom and algal community composition and ecological metrics in the Kootenai River for four years, one (2004) before, and three (2005 through 2007) after nutrient addition. The study area encompassed a 325 km river reach from the upper Kootenay River at Wardner, B.C. (river kilometer (rkm) 445) downstream through Montana and Idaho to Kootenay Lake in B.C. (rkm 120). Sampling reaches included an unimpounded reach furthest upstream and four reaches downstream from Libby Dam affected by impoundment: two in the canyon reach (one with and one without nutrient addition), a braided reach

  5. Communities of arbuscular mycorrhizal fungi detected in forest soil are spatially heterogeneous but do not vary throughout the growing season.

    Science.gov (United States)

    Davison, John; Öpik, Maarja; Zobel, Martin; Vasar, Martti; Metsis, Madis; Moora, Mari

    2012-01-01

    Despite the important ecosystem role played by arbuscular mycorrhizal fungi (AMF), little is known about spatial and temporal variation in soil AMF communities. We used pyrosequencing to characterise AMF communities in soil samples (n = 44) from a natural forest ecosystem. Fungal taxa were identified by BLAST matching of reads against the MaarjAM database of AMF SSU rRNA gene diversity. Sub-sampling within our dataset and experimental shortening of a set of long reads indicated that our approaches to taxonomic identification and diversity analysis were robust to variations in pyrosequencing read length and numbers of reads per sample. Different forest plots (each 10 × 10 m and separated from one another by 30 m) contained significantly different soil AMF communities, and the pairwise similarity of communities decreased with distance up to 50 m. However, there were no significant changes in community composition between different time points in the growing season (May-September). Spatial structure in soil AMF communities may be related to the heterogeneous vegetation of the natural forest study system, while the temporal stability of communities suggests that AMF in soil represent a fairly constant local species pool from which mycorrhizae form and disband during the season.

  6. Communities of arbuscular mycorrhizal fungi detected in forest soil are spatially heterogeneous but do not vary throughout the growing season.

    Directory of Open Access Journals (Sweden)

    John Davison

    Full Text Available Despite the important ecosystem role played by arbuscular mycorrhizal fungi (AMF, little is known about spatial and temporal variation in soil AMF communities. We used pyrosequencing to characterise AMF communities in soil samples (n = 44 from a natural forest ecosystem. Fungal taxa were identified by BLAST matching of reads against the MaarjAM database of AMF SSU rRNA gene diversity. Sub-sampling within our dataset and experimental shortening of a set of long reads indicated that our approaches to taxonomic identification and diversity analysis were robust to variations in pyrosequencing read length and numbers of reads per sample. Different forest plots (each 10 × 10 m and separated from one another by 30 m contained significantly different soil AMF communities, and the pairwise similarity of communities decreased with distance up to 50 m. However, there were no significant changes in community composition between different time points in the growing season (May-September. Spatial structure in soil AMF communities may be related to the heterogeneous vegetation of the natural forest study system, while the temporal stability of communities suggests that AMF in soil represent a fairly constant local species pool from which mycorrhizae form and disband during the season.

  7. Together we work, together we grow old: life, work and community in a coal mining town

    Energy Technology Data Exchange (ETDEWEB)

    Sachs, P.

    1986-01-01

    A critical aspect of generational continuity is the passing on of a legacy to one's heirs. What happens to elders in a community when this process is disrupted through outmigration. The authors explores how the residents of Decker's Creek, a small former coal mining community in northern West Virginia, have responded to such social change in their community. An understanding of the notions of generation and community are important to her argument. She begins with Arensberg's enduring article about the relationship between community and industry as a basis for thinking about communities. Mannheim's ideas about generation organize her sense of how involvement in a major technological change wrought by the industrial resolution (the mechanization of the mines) served to cement the older mining families into a generation. The remainder of Chapter I reviews the relevant discussions about ethnography in the US, old age, work, and economy. Chapter II, describes the historical, industrial , and cultural changes that have been taking place in Appalachia since it was first subject to mining. The remaining 4 chapters discuss, respectively: the shift from handloading to mechanization in the 1920s and 1930s; community shift from a company town to a bedroom suburb; two dramatic crises by the retired miners in the 1970s; and reassessment of the issue of generational process and community change.

  8. Fungal endophytic communities on twigs of fast and slow growing Scots pine (Pinus sylvestris L.) in northern Spain.

    Science.gov (United States)

    Sanz-Ros, Antonio V; Müller, Michael M; San Martín, Roberto; Diez, Julio J

    2015-10-01

    Most plant species harbour a diverse community of endophytic, but their role is still unknown in most cases, including ecologically and economically important tree species. This study describes the culturable fungal endophytic community of Pinus sylvestris L. twigs in northern Spain and its relationship with diametric growth of the host. In all, 360 twig samples were collected from 30 Scots pines in fifteen stands. Isolates were obtained from all twig samples and 43 fungal taxa were identified by morphogrouping and subsequent ITS rDNA sequencing. All isolates were Ascomycetes, being Dothideomycetes and Sordariomycetes the most abundant classes. Half of the species were host generalists while the others were conifer or pine specialists. We found three new endophytic species for the Pinaceae: Biscogniauxia mediterranea, Phaeomoniella effusa and Plectania milleri, and additional six new species for P. sylvestris: Daldinia fissa, Hypocrea viridescens, Nigrospora oryzae, Ophiostoma nigrocarpum, Penicillium melinii and Penicillium polonicum. The endophytic community of fast and slow growing trees showed differences in species composition, abundance and evenness, but not in diversity. Phoma herbarum was associated to fast growing trees and Hypocrea lixii to those growing slow. Our results support the hypothesis that some endophytic species may affect growth of P. sylvestris.

  9. Algal blooms and Membrane Based Desalination Technology

    NARCIS (Netherlands)

    Villacorte, L.O.

    2014-01-01

    Seawater desalination is rapidly growing in terms of installed capacity (~80 million m3/day in 2013), plant size and global application. An emerging threat to this technology is the seasonal proliferation of microscopic algae in seawater known as algal blooms. Such blooms have caused operational pro

  10. Growing Leaders "from" within: School Forms a Tight-Knit Learning Community to Tackle Literacy

    Science.gov (United States)

    Lent, ReLeah Cossett; Voigt, Marsha McCracken

    2014-01-01

    There are two types of school leadership initiatives. One takes existing leaders and gives them increasing leadership responsibilities. The other engages in an organic process that grows leaders from a crop of teachers who, at first may not appear to be leaders at all. This article presents a story about the second type of initiative and how it…

  11. Communities of practice in nursing academia: a growing need to practice what we teach.

    Science.gov (United States)

    Risling, Tracie; Ferguson, Linda

    2013-08-22

    Although the community of practice (CoP) concept has been heavily utilized in business literature since its inception in the 1990s, it has not been significantly featured in nursing research. With student-centered approaches increasingly infusing nursing classrooms, including opportunities for collaborative learning and the development of student learning communities, it may be time to ask: Do we practice what we teach? Nursing academia faces challenges related to recruitment and retention, scholarly productivity and engagement of new faculty, and increasing demands for collaborative research. Challenges, some would argue, that could be addressed through CoPs; a sentiment reflected in the recent expansion of nursing CoP literature. What is the current state of the application of this concept in nursing academia and what barriers present in the promotion and development of CoPs in the academy? This article addresses these questions and provides guidance for those in search of community.

  12. Growing Our Own: A Sustainable Approach to Teacher Education at Turtle Mountain Community College

    Science.gov (United States)

    Lamb, Carmelita

    2014-01-01

    Through its teacher education program, Turtle Mountain Community College (TMCC) is meeting the Anishinaabe of North Dakota's educational needs, strengthening tribal sovereignty and self-determination, and positively affecting people's lives. Pivotal to the success of the teacher education program are strongly committed faculty, supportive staff,…

  13. Growing up in Violent Communities: Do Family Conflict and Gender Moderate Impacts on Adolescents' Psychosocial Development?

    Science.gov (United States)

    McKelvey, Lorraine M.; Whiteside-Mansell, Leanne; Bradley, Robert H.; Casey, Patrick H.; Conners-Burrow, Nicola A.; Barrett, Kathleen W.

    2011-01-01

    This study examined the moderating effects of family conflict and gender on the relationship between community violence and psychosocial development at age 18. The study sample consisted of 728 children and families who were part of the Infant Health and Development Program study of low-birth-weight, pre-term infants. In this sample, adolescent…

  14. Supporting Children and Families: Communities, Schools, Employers Play Key Roles. Growing Up Well. Focus on Prevention.

    Science.gov (United States)

    Barthauer, Linda; Halfon, Neal

    This report, eighth and last in a series, discusses the important role community groups and leaders, schools, and employers play in providing children and parents support and encouragement. It reports the opinions of California adults, expressed in a survey conducted by the California Center for Health Improvement (CCHI), about a variety of issues…

  15. GROWING AN INTERNATIONAL MOVEMENT FOR PLANT CONSERVATION AND PLANT RESOURCE MANAGEMENT: THE DEVELOPMENT OF THE INTERNATIONAL BOTANIC GARDEN COMMUNITY

    Directory of Open Access Journals (Sweden)

    Peter Wyse Jackson

    2009-07-01

    Full Text Available The last twenty to thirty years can be said to constitute a new renaissance botanical gardens around the world. One of the main causes is the growing concern of the world community associated with the issue of loss of biodiversity. In addition, because a greater need to be institutions that take part actively in the field of conservation of plant resources. Community botanical garden world is experiencing rapid development, not only in terms of the number of new botanical garden that is built up but also of the purpose and function. There are currently no less than 2,500 botanical gardens worldwide. To prepare for a global framework for policies, programs and priorities of the botanical garden world in the field of conservation of biodiversity, in 2000 BGCI has published the International Agenda for Botanic Gardens in Conservation, which contained the botanical garden's global mission.

  16. Microbial community induces a plant defense system under growing on the lunar regolith analogue

    Science.gov (United States)

    Zaetz, Irina; Mytrokhyn, Olexander; Lukashov, Dmitry; Mashkovska, Svitlana; Kozyrovska, Natalia; Foing, Bernard H.

    The lunar rock considered as a potential source of chemical elements essential for plant nutrition, however, this substrate is of a low bioavailability. The use of microorganisms for decomposition of silicate rocks and stimulation of plant growth is a key idea in precursory scenario of growing pioneer plants for a lunar base (Kozyrovska et al., 2004; 2006; Zaetz et al., 2006). In model experiments a consortium of well-defined plant-associated bacteria were used for growing of French marigold (Tagetes patula L.) in anorthosite, analogous to a lunar rock. Inoculated plants appeared better seed germination, more fast development and also increased accumulation of K, Mg, Mn, Co, Cu and lowered level of the toxic Zn, Ni, Cr, comparing to control tagetes'. Bacteria regulate metal homeostasis in plants by changing their bioavailability and by stimulating of plant defense mechanisms. Inoculated plants were being accommodated to growth under stress conditions on anorthosite used as a substrate. In contrast, control plants manifested a heavy metal-induced oxidative stress, as quantified by protein carbonyl accumulation. Depending on the plant organ sampled and developmental stage there were increases or loses in the antioxidant enzyme activities (guaiacol peroxidase and glutathione-S-transferase). These changes were most evident in inoculated plants. Production of phenolic compounds, known as antioxidants and heavy metal chelators, is rised in variants of inoculated marigolds. Guaiacol peroxidase plays the main role, finally, in a reducing toxicity of heavy metals in plant leaves, while glutathione-S-transferase and phenolics overcome stress in roots.

  17. Sunn hemp cover cropping and organic fertilizer effects on the nematode community under temperate growing conditions.

    Science.gov (United States)

    Hinds, Jermaine; Wang, Koon-Hui; Marahatta, Sharadchandra P; Meyer, Susan L F; Hooks, Cerruti R R

    2013-12-01

    Field experiments were conducted in Maryland to investigate the influence of sunn hemp cover cropping in conjunction with organic and synthetic fertilizers on the nematode community in a zucchini cropping system. Two field treatments, zucchini planted into a sunn hemp living and surface mulch (SH) and zucchini planted into bare-ground (BG) were established during three field seasons from 2009 to 2011. In 2009, although SH slightly increased nematode richness compared with BG by the first harvest (P < 0.10), it reduced nematode diversity and enrichment indices (P < 0.01 and P < 0.10, respectively) and increased the channel index (P < 0.01) compared to BG at the final harvest. This suggests a negative impact of SH on nematode community structure. The experiment was modified in 2010 and 2011 where the SH and BG main plots were further split into two subplots to investigate the added influence of an organic vs. synthetic fertilizer. In 2010, when used as a living and surface mulch in a no-till system, SH increased bacterivorous, fungivorous, and total nematodes (P < 0.05) by the final zucchini harvest, but fertilizer type did not influence nematode community structure. In 2011, when incorporated into the soil before zucchini planting, SH increased the abundance of bacterivorous and fungivorous nematodes early in the cropping season. SH increased species richness also at the end of the season (P < 0.05). Fertilizer application did not appear to influence nematodes early in the season. However, in late season, organic fertilizers increased enrichment and structure indices and decreased channel index by the end of the zucchini cropping cycle.

  18. Growing healthy children and communities: Children's insights in Lao People's Democratic Republic.

    Science.gov (United States)

    Ruiz-Casares, Mónica

    2016-01-01

    A diverse group of 103 children aged 7-11 years old living in family and residential care in rural and urban settings in two northern provinces in Lao People's Democratic Republic participated in group discussions using images and community mapping. Children's identified sources of risk and protection illustrate primary public health and protection concerns and resources. Young children worried about lack of hygiene, unintentional injuries, corporal punishment, and domestic violence. They also expressed concern about gambling and children sleeping in the streets, even if they had never seen any of the latter in their communities. In contrast, food and shelter; artistic, religious, and cultural practices; supportive interpersonal relationships; and schooling largely evoked feelings of safety and belonging. Images that prompted conflicting interpretations surfaced individual and contextual considerations that nuanced analysis. Researchers and decision-makers will benefit from using this developmentally appropriate, context-sensitive child-centred visual method to elicit young children's views of risk and protection. It may also serve as a tool for public health education. Involving young children in the initial selection of images would further enhance the efficiency of the method.

  19. Uniform algal growth in photobioreactors using surface scatterers

    Science.gov (United States)

    Ahsan, Syed S.; Pereyra, Brandon; Erickson, David

    2014-03-01

    Cultures of algae, such as cyanobacteria, are a promising source of renewable energy. However, algal growth is highly dependent on light intensity and standard photobioreactors do a poor job of distributing light uniformly for algal utilization due to shading effects in dense algal cultures. Engineered scattering schemes are already employed in current slab-waveguide technologies, like edge-lit LEDs. Stacking such slab-waveguides that uniformly distribute light could potentially yield photobioreactors to overcome the shading effect and grow extremely high densities of algal cultures that would lower monetary and energetic costs. Here, we characterize and design a scattering scheme for specific application within photobioreactors which employs a gradient distribution of surface scatterers with uniform lateral scattering intensity. This uniform scattering scheme is shown to be superior for algal cultivation.

  20. "Being responsible, respectful, trying to keep the tradition alive:" cultural resilience and growing up in an Alaska Native community.

    Science.gov (United States)

    Wexler, Lisa; Joule, Linda; Garoutte, Joe; Mazziotti, Janet; Hopper, Kim

    2014-10-01

    Indigenous circumpolar youth are experiencing challenges of growing up in a context much different from that of their parents and their grandparents due to rapid and imposed social change. Our study is interested in community resilience: the meaning systems, resources, and relationships that structure how youth go about overcoming difficulties. The research reflects an understanding that social and cultural ecologies influence people's available and meaningful options. The in-depth, qualitative study of 20 youth from the same Arctic community shows Inupiat (Alaska Native) youth are navigating challenges. Findings from this research suggest that Inupiat youth reflect more flexible patterns of resilience when they are culturally grounded. This cultural foundation involves kinship networks that mediate young people's access to cultural and material assets. Our participants emphasized the importance of taking care of others and "giving back to the community." Being "in the country" linked youth to traditional ontology that profoundly shifted how youth felt in relation to themselves, to others, and the world. The vast majority of participants' "fulfillment narratives" centered on doing subsistence and/or cultural activities. In relation to this, young people were more likely to demonstrate versatility in their resilience strategies when deploying coherent self-narratives that reflected novel yet culturally resonant styles. Young women were more likely to demonstrate this by reconfiguring notions of culture and gender identity in ways that helped them meet challenges in their lives. Lastly, generational differences in understandings signal particular ways that young people's historical and political positioning influences their access to cultural resources.

  1. Algal blooms and Membrane Based Desalination Technology

    OpenAIRE

    Villacorte, L.O.

    2014-01-01

    Seawater desalination is rapidly growing in terms of installed capacity (~80 million m3/day in 2013), plant size and global application. An emerging threat to this technology is the seasonal proliferation of microscopic algae in seawater known as algal blooms. Such blooms have caused operational problems in seawater reverse osmosis (SWRO) plants due to clogging and poor effluent quality of the pre-treatment system which eventually forced the shutdown of the plant to avoid irreversible fouling...

  2. FLOATING COMMUNITIES OF ALGAE IN AN ARTIFICIAL POND IN THE PARQUE DO ESTADO, SÃO PAULO, BRAZIL(1).

    Science.gov (United States)

    de Mattos Bicudo, C E; Teixeira Bicudo, R M

    1967-12-01

    A fresluvater floating algal community was repeatedly observed in an artificial pond in the Parque do Estado São Paulo, Brazil. The ontogeny and composition of the community are discussed and are related to oxygen liberation during photosynthesis of the periphyton, or of the pond-bottom algne, which carries up portions of the algae growing there.

  3. Macroinvertebrate and algal community sample collection methods and data collected at selected sites in the Eagle River watershed, Colorado, 2000-07

    Science.gov (United States)

    Zuellig, Robert E.; Bruce, James F.

    2010-01-01

    State and local agencies are concerned about the effects of increasing urban development and human population growth on water quality and the biological condition of regional streams in the Eagle River watershed. In response to these needs, the U.S. Geological Survey initiated a study in cooperation with the Colorado River Water Conservation District, Eagle County, Eagle River Water and Sanitation District, Upper Eagle Regional Water Authority, Colorado Department of Transportation, City of Aurora, Town of Eagle, Town of Gypsum, Town of Minturn, Town of Vail, Vail Resorts, Colorado Springs Utilities, Denver Water, and the U.S. Department of Agriculture Forest Service. As part of this study, previously collected macroinvertebrate and algal data from the Eagle River watershed were compiled. This report includes macroinvertebrate data collected by the U.S. Geological Survey and(or) the U.S. Department of Agriculture Forest Service from 73 sites from 2000 to 2007 and algal data collected from up to 26 sites between 2000 and 2001 in the Eagle River watershed. Additionally, a brief description of the sample collection methods and data processing procedures are presented.

  4. Insight into the genetic components of community genetics: QTL mapping of insect association in a fast-growing forest tree.

    Directory of Open Access Journals (Sweden)

    Jennifer DeWoody

    Full Text Available Identifying genetic sequences underlying insect associations on forest trees will improve the understanding of community genetics on a broad scale. We tested for genomic regions associated with insects in hybrid poplar using quantitative trait loci (QTL analyses conducted on data from a common garden experiment. The F2 offspring of a hybrid poplar (Populus trichocarpa x P. deltoides cross were assessed for seven categories of insect leaf damage at two time points, June and August. Positive and negative correlations were detected among damage categories and between sampling times. For example, sap suckers on leaves in June were positively correlated with sap suckers on leaves (P<0.001 but negatively correlated with skeletonizer damage (P<0.01 in August. The seven forms of leaf damage were used as a proxy for seven functional groups of insect species. Significant variation in insect association occurred among the hybrid offspring, including transgressive segregation of susceptibility to damage. NMDS analyses revealed significant variation and modest broad-sense heritability in insect community structure among genets. QTL analyses identified 14 genomic regions across 9 linkage groups that correlated with insect association. We used three genomics tools to test for putative mechanisms underlying the QTL. First, shikimate-phenylpropanoid pathway genes co-located to 9 of the 13 QTL tested, consistent with the role of phenolic glycosides as defensive compounds. Second, two insect association QTL corresponded to genomic hotspots for leaf trait QTL as identified in previous studies, indicating that, in addition to biochemical attributes, leaf morphology may influence insect preference. Third, network analyses identified categories of gene models over-represented in QTL for certain damage types, providing direction for future functional studies. These results provide insight into the genetic components involved in insect community structure in a fast-growing

  5. Algal response to nutrient enrichment in forested oligotrophic stream

    NARCIS (Netherlands)

    Veraart, A.J.; Romaní, A.M.; Tornés, E.; Sabater, S.

    2008-01-01

    Nutrient input in streams alters the density and species composition of attached algal communities in open systems. However, in forested streams, the light reaching the streambed (rather than the local nutrient levels) may limit the growth of these communities. A nutrient-enrichment experiment in a

  6. Algal response to nutrient enrichment in a forested oligotrophic stream

    NARCIS (Netherlands)

    Veraart, A.J.; Romani, A.M.; Tornes, E.; Sabater, S.

    2008-01-01

    Nutrient input in streams alters the density and species composition of attached algal communities in open systems. However, in forested streams, the light reaching the streambed (rather than the local nutrient levels) may limit the growth of these communities. A nutrient-enrichment experiment in a

  7. National Algal Biofuels Technology Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    Ferrell, John [Dept. of Energy (DOE), Washington DC (United States); Sarisky-Reed, Valerie [Dept. of Energy (DOE), Washington DC (United States)

    2010-05-01

    The framework for National Algal Biofuels Technology Roadmap was constructed at the Algal Biofuels Technology Roadmap Workshop, held December 9-10, 2008, at the University of Maryland-College Park. The Workshop was organized by the Biomass Program to discuss and identify the critical challenges currently hindering the development of a domestic, commercial-scale algal biofuels industry. This Roadmap presents information from a scientific, economic, and policy perspectives that can support and guide RD&D investment in algal biofuels. While addressing the potential economic and environmental benefits of using algal biomass for the production of liquid transportation fuels, the Roadmap describes the current status of algae RD&D. In doing so, it lays the groundwork for identifying challenges that likely need to be overcome for algal biomass to be used in the production of economically viable biofuels.

  8. Distribution, behavior, and condition of herbivorous fishes on coral reefs track algal resources.

    Science.gov (United States)

    Tootell, Jesse S; Steele, Mark A

    2016-05-01

    Herbivore distribution can impact community structure and ecosystem function. On coral reefs, herbivores are thought to play an important role in promoting coral dominance, but how they are distributed relative to algae is not well known. Here, we evaluated whether the distribution, behavior, and condition of herbivorous fishes correlated with algal resource availability at six sites in the back reef environment of Moorea, French Polynesia. Specifically, we tested the hypotheses that increased algal turf availability would coincide with (1) increased biomass, (2) altered foraging behavior, and (3) increased energy reserves of herbivorous fishes. Fish biomass and algal cover were visually estimated along underwater transects; behavior of herbivorous fishes was quantified by observations of focal individuals; fish were collected to assess their condition; and algal turf production rates were measured on standardized tiles. The best predictor of herbivorous fish biomass was algal turf production, with fish biomass increasing with algal production. Biomass of herbivorous fishes was also negatively related to sea urchin density, suggesting competition for limited resources. Regression models including both algal turf production and urchin density explained 94 % of the variation in herbivorous fish biomass among sites spread over ~20 km. Behavioral observations of the parrotfish Chlorurus sordidus revealed that foraging area increased as algal turf cover decreased. Additionally, energy reserves increased with algal turf production, but declined with herbivorous fish density, implying that algal turf is a limited resource for this species. Our findings support the hypothesis that herbivorous fishes can spatially track algal resources on coral reefs.

  9. Paul Goodman, 30 Years Later: "Growing Up Absurd"; "Compulsory Mis-Education, and The Community of Scholars"; and "The New Reformation"--A Retrospective

    Science.gov (United States)

    Kaminsky, James S.

    2006-01-01

    This article is a retrospective account of the legacy of Paul Goodman's major educational works: "Growing Up Absurd"; "Compulsory Mis-education, and The Community of Scholars"; and "The New Reformation." It is argued here that what remains of interest in Goodman's work is to be found in the tropes and the anarchic Zeitgeist of his work. The legacy…

  10. Advanced Algal Systems Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-06-01

    Research and development (R&D) on advanced algal biofuels and bioproducts presents an opportunity to sustainably expand biomass resource potential in the United States. The Bioenergy Technologies Office’s (BETO’s) Advanced Algal Systems Program is carrying out a long-term, applied R&D strategy to lower the costs of algal biofuel production by working with partners to develop revolutionary technologies and conduct crosscutting analyses to better understand the potential

  11. Coupling of algal biofuel production with wastewater.

    Science.gov (United States)

    Bhatt, Neha Chamoli; Panwar, Amit; Bisht, Tara Singh; Tamta, Sushma

    2014-01-01

    Microalgae have gained enormous consideration from scientific community worldwide emerging as a viable feedstock for a renewable energy source virtually being carbon neutral, high lipid content, and comparatively more advantageous to other sources of biofuels. Although microalgae are seen as a valuable source in majority part of the world for production of biofuels and bioproducts, still they are unable to accomplish sustainable large-scale algal biofuel production. Wastewater has organic and inorganic supplements required for algal growth. The coupling of microalgae with wastewater is an effective way of waste remediation and a cost-effective microalgal biofuel production. In this review article, we will primarily discuss the possibilities and current scenario regarding coupling of microalgal cultivation with biofuel production emphasizing recent progress in this area.

  12. Coupling of Algal Biofuel Production with Wastewater

    Directory of Open Access Journals (Sweden)

    Neha Chamoli Bhatt

    2014-01-01

    Full Text Available Microalgae have gained enormous consideration from scientific community worldwide emerging as a viable feedstock for a renewable energy source virtually being carbon neutral, high lipid content, and comparatively more advantageous to other sources of biofuels. Although microalgae are seen as a valuable source in majority part of the world for production of biofuels and bioproducts, still they are unable to accomplish sustainable large-scale algal biofuel production. Wastewater has organic and inorganic supplements required for algal growth. The coupling of microalgae with wastewater is an effective way of waste remediation and a cost-effective microalgal biofuel production. In this review article, we will primarily discuss the possibilities and current scenario regarding coupling of microalgal cultivation with biofuel production emphasizing recent progress in this area.

  13. Algal biofuels from wastewater treatment high rate algal ponds.

    Science.gov (United States)

    Craggs, R J; Heubeck, S; Lundquist, T J; Benemann, J R

    2011-01-01

    This paper examines the potential of algae biofuel production in conjunction with wastewater treatment. Current technology for algal wastewater treatment uses facultative ponds, however, these ponds have low productivity (∼10 tonnes/ha.y), are not amenable to cultivating single algal species, require chemical flocculation or other expensive processes for algal harvest, and do not provide consistent nutrient removal. Shallow, paddlewheel-mixed high rate algal ponds (HRAPs) have much higher productivities (∼30 tonnes/ha.y) and promote bioflocculation settling which may provide low-cost algal harvest. Moreover, HRAP algae are carbon-limited and daytime addition of CO(2) has, under suitable climatic conditions, the potential to double production (to ∼60 tonnes/ha.y), improve bioflocculation algal harvest, and enhance wastewater nutrient removal. Algae biofuels (e.g. biogas, ethanol, biodiesel and crude bio-oil), could be produced from the algae harvested from wastewater HRAPs, The wastewater treatment function would cover the capital and operation costs of algal production, with biofuel and recovered nutrient fertilizer being by-products. Greenhouse gas abatement results from both the production of the biofuels and the savings in energy consumption compared to electromechanical treatment processes. However, to achieve these benefits, further research is required, particularly the large-scale demonstration of wastewater treatment HRAP algal production and harvest.

  14. Addressing the challenges for sustainable production of algal biofuels: I. Algal strains and nutrient supply.

    Science.gov (United States)

    Abdelaziz, Ahmed E M; Leite, Gustavo B; Hallenbeck, Patrick C

    2013-01-01

    Microalgae hold promise for the production of sustainable replacement of fossil fuels due to their high growth rates, ability to grow on non-arable land and their high content, under the proper conditions, of high energy compounds that can be relatively easily chemically converted to fuels using existing technology. However, projected large-scale algal production raises a number of sustainability concerns concerning land use, net energy return, water use and nutrient supply. The state-of-the-art of algal production of biofuels is presented with emphasis on some possible avenues to provide answers to the sustainability questions that have been raised. Here, issues concerning algal strains and supply of nutrients for large-scale production are discussed. Since sustainability concerns necessitate the use of wastewaters for supply of bulk nutrients, emphasis is placed on the composition and suitability of different wastewater streams. At the same time, algal cultivation has proven useful in waste treatment processes, and thus this aspect is also treated in some detail.

  15. Variations in bacterial communities during foliar litter decomposition in the winter and growing seasons in an alpine forest of the eastern Tibetan Plateau.

    Science.gov (United States)

    Zhao, Yeyi; Wu, Fuzhong; Yang, Wanqin; Tan, Bo; He, Wei

    2016-01-01

    Bacterial communities are the primary engineers during litter decomposition and related material cycling, and they can be strongly controlled by seasonal changes in temperature and other environmental factors. However, limited information is available on changes in the bacterial community from winter to the growing season as litter decomposition proceeds in cold climates. Here, we investigated the abundance and structure of bacterial communities using real-time quantitative PCR and denaturing gradient gel electrophoresis (DGGE) during a 2-year field study of the decomposition of litter of 4 species in the winter and growing seasons of an alpine forest of the eastern Tibetan Plateau. The abundance of the bacterial 16S rRNA gene was relatively high during decomposition of cypress and birch litter in the first winter, but for the other litters 16S rRNA abundance during both winters was significantly lower than during the following growing season. A large number of bands were observed on the DGGE gels, and their intensities and number from the winter samples were lower than those from the growing season during the 2-year decomposition experiment. Eighty-nine sequences from the bands of bacteria that had been cut from the DGGE gels were affiliated with 10 distinct classes of bacteria and an unknown group. A redundancy analysis indicated that the moisture, mass loss, and elemental content (e.g., C, N, and P) of the litter significantly affected the bacterial communities. Collectively, the results suggest that uneven seasonal changes in climate regulate bacterial communities and other decomposers, thus affecting their contribution to litter decomposition processes in the alpine forest.

  16. Characterization of Growing Soil Bacterial Communities across a pH gradient Using H218O DNA-Stable Isotope Probing

    Science.gov (United States)

    Welty-Bernard, A. T.; Schwartz, E.

    2014-12-01

    Recent studies have established consistent relationships between pH and bacterial diversity and community structure in soils from site-specific to landscape scales. However, these studies rely on DNA or PLFA extraction techniques from bulk soils that encompass metabolically active and inactive, or dormant, communities, and loose DNA. Dormant cells may comprise up to 80% of total live cells. If dormant cells dominate a particular environment, it is possible that previous interpretations of the soil variables assumed to drive communities could be profoundly affected. We used H218O stable isotope probing and bar-coded illumina sequencing of 16S rRNA genes to monitor the response of actively growing communities to changes in soil pH in a soil microcosm over 14 days. This substrate-independent approach has several advantages over 13C or 15N-labelled molecules in that all growing bacteria should be able to make use of water, allowing characterization of whole communities. We hypothesized that Acidobacteria would increasingly dominate the growing community and that Actinobacteria and Bacteroidetes would decline, given previously established responses by these taxa to soil pH. Instead, we observed the reverse. Actinobacteria abundance increased three-fold from 26 to 76% of the overall community as soil pH fell from pH 5.6 to pH 4.6. Shifts in community structure and decreases in diversity with declining soil pH were essentially driven by two families, Streptomyceaca and Microbacteracea, which collectively increased from 2 to 40% of the entire community. In contrast, Acidobacteria as a whole declined although numbers of subdivision 1 remained stable across all soil pH levels. We suggest that the brief incubation period in this SIP study selected for growth of acid-tolerant Actinobacteria over Acidobacteria. Taxa within Actinomycetales have been readily cultured over short time frames, suggesting rapid growth patterns. Conversely, taxa within Acidobacteria have been

  17. Algal functional annotation tool

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, D. [UCLA; Casero, D. [UCLA; Cokus, S. J. [UCLA; Merchant, S. S. [UCLA; Pellegrini, M. [UCLA

    2012-07-01

    The Algal Functional Annotation Tool is a web-based comprehensive analysis suite integrating annotation data from several pathway, ontology, and protein family databases. The current version provides annotation for the model alga Chlamydomonas reinhardtii, and in the future will include additional genomes. The site allows users to interpret large gene lists by identifying associated functional terms, and their enrichment. Additionally, expression data for several experimental conditions were compiled and analyzed to provide an expression-based enrichment search. A tool to search for functionally-related genes based on gene expression across these conditions is also provided. Other features include dynamic visualization of genes on KEGG pathway maps and batch gene identifier conversion.

  18. Letting Go and Letting the Angels Grow: Using Etienne Wenger's Community of Practice Theory to Facilitate Teacher Education

    Science.gov (United States)

    Breen, Paul

    2015-01-01

    This paper describes a small-scale qualitative research study conducted within a community of English Language teachers, and explores how teacher development workshops can be used to foster or cultivate Communities of Practice. The study was situated in a Language Centre within the domain of UK Higher Education where there was an institutional…

  19. A Healthy Harvest: Adolescents Grow Food and Well-Being with Policy Implications for Education, Health and Community Planning

    Science.gov (United States)

    Pevec, Illene Susan

    2011-01-01

    The severe youth health crisis involving overweight and obesity requires a complex policy response involving multiple domains: education, agriculture, health services, and community planning. This research examines gardening's affective benefits for adolescents and the potential school and youth gardens have to support healthy communities.…

  20. Algal Biofuels; Algal Biofuels R&D at NREL (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2010-09-01

    An overview of NREL's algal biofuels projects, including U.S. Department of Energy-funded work, projects with U.S. and international partners, and Laboratory Directed Research and Development projects.

  1. 水华生消过程对巢湖沉积物微生物群落结构的影响%Effects of Outbreak and Extinction of Algal Blooms on the Microbial Community Structure in Sediments of Chaohu Lake

    Institute of Scientific and Technical Information of China (English)

    刁晓君; 李一葳; 王曙光

    2015-01-01

    Although impacts of algal bloom on the physicochemical and biological properties of water and sediment in many lakes have been largely studied, less attention is paid to the impact of outbreak and extinction of algal blooms on the microbial community structure in sediment. In this study, outbreak and extinction of algal blooms and their effects on the microbial community structure in sediment of Chaohu Lake were studied by PCR-DGGE method. The results showed that algal blooms formed between May 15 and June 20, sustained from June 20 to September 5, and then went into extinction. In the region without algal blooms, PCR-DGGE analysis showed that microbial species, Shannon-Wiener diversity index and Simpson dominance index changed slightly over time; moreover, the microbial community structure had high similarity during the whole study. Temperature may be the main factor affecting the fluctuation of the microbial community structure in this region. In the region with algal blooms, however, microbial species and Shannon-Wiener diversity index were higher during the formation and extinction of algal blooms and lower in the sustaining blooms stage than those in the region without algal blooms. But the Simpson dominance index showed the opposite trend over time. In addition, the microbial community structure had low similarity during the whole study. The results suggested that outbreak and extinction of algal blooms produced different effects on the microbial community structure and the dominant microbial species, which may be related to the variation of water properties caused by temperature and algal blooms. This study showed that outbreak and extinction of algal blooms caused different effects on microbes in lake sediment, and this is significantly important to deeply evaluate the effects of algal bloom on the aquatic ecosystem of the lake and effectively control algal blooms using sediment microbes.%水华对湖泊水体和沉积物理化和生物学性质的影响

  2. Algal blooms: an emerging threat to seawater reverse osmosis desalination

    KAUST Repository

    Villacorte, Loreen O.

    2014-08-04

    Seawater reverse osmosis (SWRO) desalination technology has been rapidly growing in terms of installed capacity and global application over the last decade. An emerging threat to SWRO application is the seasonal proliferation of microscopic algae in seawater known as algal blooms. Such blooms have caused operational problems in SWRO plants due to clogging and poor effluent quality of the pre-treatment system which eventually forced the shutdown of various desalination plants to avoid irreversible fouling of downstream SWRO membranes. This article summarizes the current state of SWRO technology and the emerging threat of algal blooms to its application. It also highlights the importance of studying the algal bloom phenomena in the perspective of seawater desalination, so proper mitigation and preventive strategies can be developed in the near future. © 2014 © 2014 Balaban Desalination Publications. All rights reserved.

  3. Algal Bloom: Boon or Bane?

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.

    Algal blooms occur in response to nutrient deplete or replete conditions. Nitrogen fixing forms proliferate under oligotrophic conditions when nutrient levels are low. Replete conditions in response to upwelling creates the most biologically...

  4. Unusual algal turfs associated with the rhodophyta Phyllophora crispa: Benthic assemblages along a depth gradient in the Central Mediterranean Sea

    Science.gov (United States)

    Bonifazi, Andrea; Ventura, Daniele; Gravina, Maria Flavia; Lasinio, Giovanna Jona; Belluscio, Andrea; Ardizzone, Gian Domenico

    2017-02-01

    Macroalgal assemblages dominated by the turf-forming alga Phyllophora crispa are described in detail for the first time in the Central Mediterranean Sea. This particular form of algal growth, which comprises an upper mixed layer of multiple algal species with a basal stratum formed by entangled thalli of P. crispa, was observed for the first time in 2012 along the promontory of Punta del Lazzaretto (Giglio Island, Italy). In this study, this assemblage was analysed to document the diversity of macroalgae and invertebrate associated communities and assess their distribution along a depth gradient. The algae forming turfs grow directly on the rock at low depth up to 10-15 m depth, while they grow above P. crispa from 15 m to 35 m depth, resulting in luxuriant beds covering up to 100% of the substrate. Multivariate analysis revealed clear differences regarding algae and invertebrate species richness and abundance between shallow and deep strata because of the dominance of Phyllophora crispa at depths greater than 20 m. The long laminal thalli of P. crispa favoured sessile fauna colonization, while the vagile species were principally linked to the architectural complexity of the turf layer created by the P. crispa, which increased the microhabitat diversity and favoured sediment deposition within the turf layer. The complex structures of these turf assemblages and their widespread distribution along the whole coast of the island suggest a well-established condition of the communities linked to the high natural sedimentation rate observed in the area.

  5. Differences of periphyfic algal community structure in different sections of Fanhe River, Liaoning Province of Northeast China%汎河不同断面着生藻类群落结构差异性

    Institute of Scientific and Technical Information of China (English)

    付保荣; 张润洁; 李霞; 惠秀娟; 张楠; 付豪; 张铮; 谢轶

    2013-01-01

    In dry and rainy seasons of 2011, an investigation was conducted on the species and density of periphytic algal communities in ten sections of Fanhe River located in northern Liaon-ing Province of Northeast China. A total of 47 genera, 25 families, 16 orders, 8 classes, and 6 phyla were identified, with 35 genera in dry season and 32 genera in rainy season. The periphytic algal communities in the River were mainly consisted of diatoms, followed by green algae and blue algae. The average density of the algae was 11.92×10 cell·cm-2 in dry season and 3.75× 10 cell·cm-2 in rainy season. The dominant species in dry season were Synedra ulna, S. acus , Fragilaria brevistriata, F. capucina, Diatoma vulgare, Cymbella qffinis, C. ventricosa, and C. cistula, and those in rainy season were Oscillatoria formosa, O. tenuis, Phormidium sp. , Syne-dra ulna, Gomphonema acuminatum, and Cocconeis placentula. The evaluation with Shannon di-versity index indicated that the water quality of the River was of slight pollution.%于2011年枯水期、丰水期对辽宁省北部况河10个断面的着生藻类的种类、生物密度进行了调查.结果表明:监测到着生藻类6门8纲16目25科47属,其中枯水期监测到35属,丰水期监测到32属;沉河着生藻类群落主要由硅藻组成,其次是蓝藻和绿藻;枯水期汎河各断面着生藻类生物密度平均为11.92×105个·cm-2,丰水期的生物密度平均为3.75×105个·cm-2;枯水期汎河着生藻类的优势种主要有肘状针杆藻(Synedra ulna)、尖针杆藻(S.acus)、短线脆杆藻(Fragilaria brevistriata)、钝脆杆藻(F.capucina)、普通等片藻(Diatoma vulgare)、近缘桥弯藻(Cymbella affinis)、偏肿桥弯藻(C.ventricosa)、箱形桥弯藻(C.cistula);丰水期优势种主要有美丽颤藻(Oscillatoria formosa)、两栖颤藻(O.tenuis)、席藻(Phormidium sp.)、肘状针杆藻(S.ulna)、尖异极藻(Gomphonema acuminatum)、扁圆卵形藻(Cocconeis placentula);Shannon多样

  6. Fueling Future with Algal Genomics

    Energy Technology Data Exchange (ETDEWEB)

    Grigoriev, Igor

    2012-07-05

    Algae constitute a major component of fundamental eukaryotic diversity, play profound roles in the carbon cycle, and are prominent candidates for biofuel production. The US Department of Energy Joint Genome Institute (JGI) is leading the world in algal genome sequencing (http://jgi.doe.gov/Algae) and contributes of the algal genome projects worldwide (GOLD database, 2012). The sequenced algal genomes offer catalogs of genes, networks, and pathways. The sequenced first of its kind genomes of a haptophyte E.huxleyii, chlorarachniophyte B.natans, and cryptophyte G.theta fill the gaps in the eukaryotic tree of life and carry unique genes and pathways as well as molecular fossils of secondary endosymbiosis. Natural adaptation to conditions critical for industrial production is encoded in algal genomes, for example, growth of A.anophagefferens at very high cell densities during the harmful algae blooms or a global distribution across diverse environments of E.huxleyii, able to live on sparse nutrients due to its expanded pan-genome. Communications and signaling pathways can be derived from simple symbiotic systems like lichens or complex marine algae metagenomes. Collectively these datasets derived from algal genomics contribute to building a comprehensive parts list essential for algal biofuel development.

  7. Algal taxonomy: a road to nowhere?

    Science.gov (United States)

    De Clerck, Olivier; Guiry, Michael D; Leliaert, Frederik; Samyn, Yves; Verbruggen, Heroen

    2013-04-01

    The widespread view of taxonomy as an essentially retrogressive and outmoded science unable to cope with the current biodiversity crisis stimulated us to analyze the current status of cataloguing global algal diversity. Contrary to this largely pessimistic belief, species description rates of algae through time and trends in the number of active taxonomists, as revealed by the web resource AlgaeBase, show a much more positive picture. More species than ever before are being described by a large community of algal taxonomists. The lack of any decline in the rate at which new species and genera are described, however, is indicative of the large proportion of undiscovered diversity and bears heavily on any prediction of global algal species diversity and the time needed to catalogue it. The saturation of accumulation curves of higher taxa (family, order, and classes) on the other hand suggest that at these taxonomic levels most diversity has been discovered. This reasonably positive picture does not imply that algal taxonomy does not face serious challenges in the near future. The observed levels of cryptic diversity in algae, combined with the shift in methods used to characterize them, have resulted in a rampant uncertainty about the status of many older species. As a consequence, there is a tendency in phycology to move gradually away from traditional names to a more informal system whereby clade-, specimen- or strain-based identifiers are used to communicate biological information. Whether these informal names for species-level clades represent a temporary situation stimulated by the lag between species discovery and formal description, or an incipient alternative or parallel taxonomy, will be largely determined by how well we manage to integrate historical collections into modern taxonomic research. Additionally, there is a pressing need for a consensus about the organizational framework to manage the information about algal species names. An eventual strategy

  8. Algal pigments in Southern Ocean abyssal foraminiferans indicate pelagobenthic coupling.

    OpenAIRE

    Cedhagen, Tomas; Cheah, Wee; Bracher, Astrid; Lejzerowicz, Franck

    2014-01-01

    The cytoplasm of four species of abyssal benthic foraminiferans from the Southern Ocean (around 51°S; 12°W and 50°S; 39°W) was analysed by High Performance Liquid Chromatography (HPLC) and found to contain large concentrations of algal pigments and their degradation products. The composition of the algal pigments in the foraminiferan cytoplasm reflected the plankton community at the surface. Some foraminiferans contained high ratios of chlorophyll a/degraded pigments because they were feeding...

  9. Every School, Every Team, Every Classroom: District Leadership for Growing Professional Learning Communities at Work[TM

    Science.gov (United States)

    Eaker, Robert; Keating, Janel

    2011-01-01

    What would a learning community look like "if we really meant it" when we committed to ensuring the learning of each student? What would we consider good enough for our own children? In "Every School, Every Team, Every Classroom," the authors suggest that these two questions drive PLC leaders to embed PLC at Work[TM] practices in their entire…

  10. Insight into the Genetic Components of Community Genetics: QTL Mapping of Insect Association in a Fast-Growing Forest Tree

    NARCIS (Netherlands)

    DeWoody, J.; Viger, M.; Lakatos, F.; Tuba, K.; Taylor, G.; Smulders, M.J.M.

    2013-01-01

    Identifying genetic sequences underlying insect associations on forest trees will improve the understanding of community genetics on a broad scale. We tested for genomic regions associated with insects in hybrid poplar using quantitative trait loci (QTL) analyses conducted on data from a common gard

  11. Variation of Potential Nitrification and Ammonia-Oxidizing Bacterial Community with Plant-Growing Period in Apple Orchard Soil

    Institute of Scientific and Technical Information of China (English)

    LIU Ling-zhi; QIN Si-jun; L De-guo; WANG Bing-ying; YANG Ze-yuan

    2014-01-01

    In this study, we investigated the potential nitriifcation and community structure of soil-based ammonia-oxidizing bacteria (AOB) in apple orchard soil during different growth periods and explored the effects of environmental factors on nitriifcation activity and AOB community composition in the soil of a Hanfu apple orchard, using a culture-dependent technique and denaturing gradient gel electrophoresis (DGGE). We observed that nitrification activity and AOB abundance were the highest in November, lower in May, and the lowest in July. The results of statistical analysis indicated that total nitrogen (N) content, NH4+-N content, NO3--N content, and pH showed signiifcant correlations with AOB abundance and nitriifcation activity in soil. The Shannon-Winner diversity, as well as species richness and evenness indices (determined by PCR-DGGE banding patterns) in soil samples were the highest in September, but the lowest in July, when compared to additional sampled dates. The DGGE ifngerprints of soil-based 16S rRNA genes in November were apparently distinct from those observed in May, July, and September, possessing the lowest species richness indices and the highest dominance indices among all four growth periods. Fourteen DGGE bands were excised for sequencing. The resulting analysis indicated that all AOB communities belonged to the β-Proteobacteriaphylum, with the dominant AOB showing high similarity to theNitrosospira genus. Therefore, soil-based environmental factors, such as pH variation and content of NH4+-N and NO3--N, can substantially inlfuence the abundance of AOB communities in soil, and play a critical role in soil-based nitriifcation kinetics.

  12. UV-Visible Spectroscopic Method and Models for Assessment and Monitoring of Harmful Algal Blooms

    Science.gov (United States)

    Mitchell, B. Greg

    2000-01-01

    The development of an enhanced predictive and early warning capability for the occurrence and impact of harmful algal blooms (HABs) would be of great benefit to coastal communities. A critical issue for early detection and monitoring of HABs is the need to detect harmful algal species within a mixed-species phytoplankton assemblage. Possession of UV-absorbing compounds called mycosporine-like amino acids (MAAs) may be one factor that allows HAB species to out-compete their phytoplankton neighbors. Possession of MAAs, which we believe can be inferred from strong UV-absorption signals in phytoplankton absorption coefficients, can be used as a flag for potential HAB outbreak. The goal of this project was to develop a solar simulating UV-visible incubator to grow HAB dinoflagellates, to begin MAA analysis of samples collected on global cruises, and to carry out initial experiments on HAB dinoflagellate species in pure culture. Our scientific objectives are to quantify MAA production and spectral induction mechanisms in HAB species, to characterize spectral absorption of MAAs, and to define the ecological benefit of MAAs (i.e. photoprotection). Data collected on cruises to the global oceans will be used to parameterize phytoplankton absorption in the UV region, and this parameterization could be incorporated into existing models of seawater optical properties in the UV spectral region. Data collected in this project were used for graduate fellowship applications by Elizabeth Frame. She has been awarded an EPA STAR fellowship to continue the work initiated by this project.

  13. Population dynamics of an algal bacterial cenosis in closed ecological system

    Science.gov (United States)

    Pisman, T. I.; Galayda, Ya. V.; Loginova, N. S.

    The paper deals with microalgae-bacteria interrelationships in the "autotroph-heterotroph" aquatic biotic cycle. Explanations of why and how algal-bacterial ecosystems are formed still remain controversial. The paper presents results of experimental and theoretical investigations of the functioning of the algal-bacterial cenosis (the microalga Chlorella vulgaris and concomitant microflora). The Chlorella microbial community is dominated by representatives of the genus Pseudomonas. Experiments with non-sterile batch cultures of Chlorella on Tamiya medium showed that the biomass of microorganisms increases simultaneously with the increase in microalgal biomass. The microflora of Chlorella can grow on organic substances released by photosynthesizing Chlorella. Microorganisms can also use dying Chlorella cells, i.e. form a "producer-reducer" biocycle. To get a better insight into the cenosis-forming role of microalgae, a mathematical model of the "autotroph-heterotroph" aquatic biotic cycle has been constructed, taking into account the utilization of Chlorella photosynthates and dead cells by microorganisms and the contribution of the components to the nitrogen cycle. A theoretical study showed that the biomass of concomitant bacteria grown on glucose and detritus is larger than the biomass of bacteria utilizing only microalgal photosynthates, which agrees well with the experimental data.

  14. Ecology of microfungal communities in gardens of fungus-growing ants (Hymenoptera: Formicidae): a year-long survey of three species of attine ants in Central Texas.

    Science.gov (United States)

    Rodrigues, Andre; Mueller, Ulrich G; Ishak, Heather D; Bacci, Maurício; Pagnocca, Fernando C

    2011-11-01

    We profiled the microfungal communities in gardens of fungus-growing ants to evaluate possible species-specific ant-microfungal associations and to assess the potential dependencies of microfungal diversity on ant foraging behavior. In a 1-year survey, we isolated microfungi from nests of Cyphomyrmex wheeleri, Trachymyrmex septentrionalis and Atta texana in Central Texas. Microfungal prevalence was higher in gardens of C. wheeleri (57%) than in the gardens of T. septentrionalis (46%) and A. texana (35%). Culture-dependent methods coupled with a polyphasic approach of species identification revealed diverse and changing microfungal communities in all the sampling periods. Diversity analyses showed no obvious correlations between the number of observed microfungal species, ant species, or the ants' changing foraging behavior across the seasons. However, both correspondence analysis and 5.8S-rRNA gene unifrac analyses suggested structuring of microfungal communities by ant host. These host-specific differences may reflect in part the three different environments where ants were collected. Most interestingly, the specialized fungal parasite Escovopsis was not isolated from any attine garden in this study near the northernmost limit of the range of attine ants, contrasting with previous studies that indicated a significant incidence of this parasite in ant gardens from Central and South America. The observed differences of microfungal communities in attine gardens suggest that the ants are continuously in contact with a diverse microfungal species assemblage.

  15. Growing community: the impact of the Stephanie Alexander Kitchen Garden Program on the social and learning environment in primary schools.

    Science.gov (United States)

    Block, Karen; Gibbs, Lisa; Staiger, Petra K; Gold, Lisa; Johnson, Britt; Macfarlane, Susie; Long, Caroline; Townsend, Mardie

    2012-08-01

    This article presents results from a mixed-method evaluation of a structured cooking and gardening program in Australian primary schools, focusing on program impacts on the social and learning environment of the school. In particular, we address the Stephanie Alexander Kitchen Garden Program objective of providing a pleasurable experience that has a positive impact on student engagement, social connections, and confidence within and beyond the school gates. Primary evidence for the research question came from qualitative data collected from students, parents, teachers, volunteers, school principals, and specialist staff through interviews, focus groups, and participant observations. This was supported by analyses of quantitative data on child quality of life, cooperative behaviors, teacher perceptions of the school environment, and school-level educational outcome and absenteeism data. Results showed that some of the program attributes valued most highly by study participants included increased student engagement and confidence, opportunities for experiential and integrated learning, teamwork, building social skills, and connections and links between schools and their communities. In this analysis, quantitative findings failed to support findings from the primary analysis. Limitations as well as benefits of a mixed-methods approach to evaluation of complex community interventions are discussed.

  16. Compounds associated with algal surfaces mediate epiphytic colonization of the marine macroalga Fucus vesiculosus.

    Science.gov (United States)

    Lachnit, Tim; Fischer, Matthias; Künzel, Sven; Baines, John F; Harder, Tilmann

    2013-05-01

    The macroalga Fucus vesiculosus carries a specific community of surface bacteria. To identify chemical compounds that possibly mediate abundance and community composition of algae-associated bacteria, we tested the effect of surface-available algal compounds on bacterial settlement and community composition under field conditions. Compounds on algal thalli were separated from the surface by extraction with organic solvents and investigated on growth inhibition and settlement of bacterial isolates. Based on in vitro data, partially purified extract fractions were then exposed to bacterial colonizers in vivo followed by bacterial enumeration and community analysis. The polar fraction of the algal surface extract revealed a significant profouling effect for Vibrionales, whereas the nonpolar fraction - containing the xanthophyll pigment fucoxanthin and other unidentified nonpolar surface compounds - revealed a significant 80% reduction of surface colonizing bacteria. The analysis of bacterial surface communities by 454 pyrosequencing demonstrated that the antifouling activity of nonpolar algal surface compounds was targeting the abundance of natural bacterial colonizers rather than the relative composition of bacterial members within the community. Moreover, the bacterial community composition on F. vesiculosus was markedly different from artificial control substrates and chemically manipulated experimental treatments, suggesting that other, nonextractable surface features and/or physical properties render algal-specific epiphytic bacterial communities.

  17. Rabbit dietary supplementation with pale purple coneflower. 2. Effects on the performances, bacterial community, blood parameters and immunity of growing rabbits.

    Science.gov (United States)

    Kovitvadhi, A; Gai, F; Dabbou, S; Ferrocino, I; Rotolo, L; Falzone, M; Vignolini, C; Gennero, M S; Bergagna, S; Dezzutto, Daniela; Barbero, R; Nebbia, P; Rosati, S; Cocolin, L; Zoccarato, I; Gasco, L

    2016-07-01

    Echinacea pallida (EPAL), a herbaceous flowering plant with immunomodulatory properties, has been chosen to determine the pre- and post-supplementary effects on the growth performances, bacterial community, blood parameters and immunity of growing rabbits. The same Grimaud does (14-week-old) from the studied in the first part of this study were randomly divided into two groups (n=50/group). The first group was fed a basal diet without supplementation (Control group, C) while the another group was fed a basal diet supplemented with 3 g EPAL/kg diet (Echinacea group, E). From the second parturition, 80 weaned kits (40 from the C does and 40 from the E does) were randomly assigned to four groups of 20 animals each and were fed a growing commercial diet supplemented with or without a 3 g EPAL/kg diet: the CC group (rabbits from the C does fed the control diet), CE group (rabbits from the C does fed the supplemented diet), EC (rabbits from the E does fed the control diet) and EE group (rabbits from the E does fed the supplemented diet). The dietary EPAL treatment did not affect the growth performance. Ten fattening rabbits from each group were selected to evaluate the bacterial community and blood parameters, while the remaining rabbits (n=10/group) were used to study phagocytosis and the humoral immune response. The variability was evaluated from hard faeces at 35, 49 and 89 days, and the caecal content at 89 days. The variability of the bacterial community of the EE group was higher than that of the other groups. The phagocytic activity was higher in the CE and EE groups than in the CC and EC ones (30.9 and 29.7 v. 21.2 and 21.8%; Pold which the serum was collected at 88, 102, 109, 116 and 123 days old. In conclusion, no impact of EPAL dietary supplementation has been observed on the growth performances, bacterial community, blood parameters or humoral immune responses in growing rabbits, except for an increase in phagocytic activities.

  18. Sapphire Energy - Integrated Algal Biorefinery

    Energy Technology Data Exchange (ETDEWEB)

    White, Rebecca L. [Sapphire Energy, Inc., Columbus, NM (United States). Columbus Algal Biomass Farm; Tyler, Mike [Sapphire Energy, Inc., San Diego, CA (United States)

    2015-07-22

    Sapphire Energy, Inc. (SEI) is a leader in large-scale photosynthetic algal biomass production, with a strongly cohesive research, development, and operations program. SEI takes a multidiscipline approach to integrate lab-based strain selection, cultivation and harvest and production scale, and extraction for the production of Green Crude oil, a drop in replacement for traditional crude oil.. SEI’s technical accomplishments since 2007 have produced a multifunctional platform that can address needs for fuel, feed, and other higher value products. Figure 1 outlines SEI’s commercialization process, including Green Crude production and refinement to drop in fuel replacements. The large scale algal biomass production facility, the SEI Integrated Algal Biorefinery (IABR), was built in Luna County near Columbus, New Mexico (see fig 2). The extraction unit was located at the existing SEI facility in Las Cruces, New Mexico, approximately 95 miles from the IABR. The IABR facility was constructed on time and on budget, and the extraction unit expansion to accommodate the biomass output from the IABR was completed in October 2012. The IABR facility uses open pond cultivation with a proprietary harvesting method to produce algal biomass; this biomass is then shipped to the extraction facility for conversion to Green Crude. The operation of the IABR and the extraction facilities has demonstrated the critical integration of traditional agricultural techniques with algae cultivation knowledge for algal biomass production, and the successful conversion of the biomass to Green Crude. All primary unit operations are de-risked, and at a scale suitable for process demonstration. The results are stable, reliable, and long-term cultivation of strains for year round algal biomass production. From June 2012 to November 2014, the IABR and extraction facilities produced 524 metric tons (MT) of biomass (on a dry weight basis), and 2,587 gallons of Green Crude. Additionally, the IABR

  19. Algal taxonomy forum: Algal Taxonomist, Let Serendipity Reign!

    Science.gov (United States)

    Druehl, Louis

    2013-04-01

    The publication of a mini-review by Olivier De Clerck et al. in this issue of the Journal of Phycology presented an opportunity to open a dialogue on challenges faced by contemporary algal taxonomists. The Editorial Office solicited the following two additional contributions in response to De Clerck et al.'s paper; the responses were edited solely for clarity, space and format.

  20. Algal assay research in programs for Euthrophic Lake management: laboratory and field studies

    Energy Technology Data Exchange (ETDEWEB)

    Lindmark, G.

    1979-01-01

    The present study is an attempt to clarify whether relations between viruses (cyanophages) and their algal hosts can be affected by manipulations in the environment. Is is possible to activate cyanophages and accelerate lysis of blue-green algal populations or to enhance the resistance of blue-green algae to attack from cynaophages. The experiments presented here were performed under laboratory conditions with a well-known algal - canophage system, Plectonema boryanum and cyanophage LPP-1 (attacking strains of Lyngbya, Phormidium and Plectonema). The work was done in close connection with field experiments on natural blue-green algal communities, however, because the nature of the induced blue-green algal collapse in plastic enclosures suggested lysis of the algal cells. The rate of LPP-1 cyanophage replication and lysis of plectonema was studied in relation to: (a) pH alterations by CO/sub 2//air additions, (b) algal host culture age and density, (c) nutrient concentrations and (d) presence of additional algal species.

  1. Study of urban community survey in India: growing trend of high prevalence of hypertension in a developing country

    Directory of Open Access Journals (Sweden)

    2005-04-01

    Full Text Available The prevalence pattern of hypertension in developing countries is different from that in the developed countries. In India, a very large, populous and typical developing country, community surveys have documented that between three and six decades, prevalence of hypertension has increased by about 30 times among urban dwellers and by about 10 times among the rural inhabitants. Various factors might have contributed to this rising trend and among others, consequences of urbanization such as change in life style pattern, diet and stress, increased population and shrinking employment have been implicated. In this paper, we study the prevalence of hypertension in an urban community of India using the JNC VII criteria, with the aim of identifying the risk factors and suggesting intervention strategies. A total of 1609 respondents out of 1662 individuals participated in our cross-sectional survey of validated and structured questionnaire followed by blood pressure measurement. Results showed pre-hypertensive levels of blood pressures among 35.8% of the participants in systolic group (120-139mm of Hg and 47.7% in diastolic group (80-89 mm of Hg. Systolic hypertension (140 mm of Hg was present in 40.9% and diastolic hypertension (90 mm of Hg in 29.3% of the participants. Age and sex-specific prevalence of hypertension showed progressive rise of systolic and diastolic hypertension in women when compared to men. Men showed progressive rise in systolic hypertension beyond fifth decade of life. Bivariate analysis showed significant relationship of hypertension with age, sedentary occupation, body mass index (BMI, diet, ischemic heart disease, and smoking. Multivariate analysis revealed age and BMI as risk factors, and non-vegetarian diet as protective factor with respect to hypertension. Prevalence of prehypertensives was high among younger subjects - particularly students and laborers who need special attention. Role of non-vegetarian diet as a protective

  2. Algal Systems for Hydrogen Photoproduction

    Energy Technology Data Exchange (ETDEWEB)

    Ghirardi, Maria L [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-10-08

    The National Renewable Energy Laboratory (NREL), under the guidance of Drs. Michael Seibert (retired, Fellow Emeritus) and Maria Ghirardi (Fellow), led 15 years of research addressing the issue of algal H2 photoproduction. This project resulted in greatly increased rates and yields of algal hydrogen production; increased understanding of the H2 metabolism in the green alga, Chlamydomonas reinhardtii; expanded our knowledge of other physiological aspects relevant to sustained algal photosynthetic H2 production; led to the genetic identification, cloning and manipulation of algal hydrogenase genes; and contributed to a broader, fundamental understanding of the technical and scientific challenges to improving the conversion efficiencies in order to reach the U.S. Department of Energy’s Fuel Cell Technologies Office’s targets. Some of the tangible results are: (i) 64 publications and 6 patents, (ii) international visibility to NREL, (iii) reinvigoration of national and international biohydrogen research, and (iv) research progress that helped stimulate new funding from other DOE and non-DOE programs, including the AFOSR and the DOE Office of Science.

  3. Prevalence and effect of schistosome and soil-transmitted helminth infection on labour input in rice-growing communities of Ogun State, Nigeria

    Directory of Open Access Journals (Sweden)

    Sammy Olufemi Sam-Wobo

    2013-06-01

    Full Text Available Schistosomiasis and soil-transmitted helminthiasis (STH are public health problems in communities which lack basic social amenities with poor hygienic conditions. Studies were carried out to determine the prevalence and effect of schistosomes and soil-transmitted helminths infection on labour input on rice production in 9 rice-growing communities of Ogun State. Parasitological examinations of urine and faecal samples, and structured questionnaires were conducted on 243 consented individuals from May 2009 to March 2010. The results showed an overall prevalence of 17% for Ascaris lumbricoides, 12% for hookworms, 2% for Trichuris trichiura, 1% for Schistosoma haematobium and 1% for Schistosoma mansoni. A. lumbricoides and hookworms were more prevalent in Agbajege (25%, and varied in the other 8 communities. T. trichiura was prevalent in three communities, Agbajege (5%, Akodu (4.2%, and Moloko-Asipa (4.8 %; S. haematobium was prevalent only in Ayedere (2.6% and Lufoko (8%, while S. mansoni was prevalent only in Moloko-Asipa (9.5%. Infections among the gender were varied as 26.3 % of males and 33.8 % of females had an overall prevalence of: A. lumbricoides (16.8%, hookworms (11.8%, T. trichiura (1.6%, S. haematobium (1.1% and S. mansoni (1.1%. On frequency of infection to incapacitation per year, 45% of respondents were incapacitated 1-2 times, 27% 3-4 times and 19% were incapacitated more than 4 times. Understanding the effect of these two diseases will not only improve the health status of residents but also increase their productivity and ensure food security.

  4. Harmful Algal Blooms and Public Health

    Science.gov (United States)

    Grattan, Lynn M.; Holobaugh, Sailor; Morris, J. Glenn

    2015-01-01

    The five most commonly recognized Harmful Algal Bloom related illnesses include Ciguatera poisoning, Paralytic Shellfish poisoning, Neurotoxin Shellfish poisoning, Diarrheic Shellfish Poisoning and Amnesic Shellfish poisoning. Although they are each the product of different toxins, toxin assemblages or HAB precursors these clinical syndromes have much in common. Exposure occurs through the consumption of fish or shellfish; routine clinical tests are not available for diagnosis; there is no known antidote for exposure; and the risk of these illnesses can negatively impact local fishing and tourism industries. Thus, illness prevention is of paramount importance to minimize human and public health risks. To accomplish this, close communication and collaboration is needed among HAB scientists, public health researchers and local, state and tribal health departments at academic, community outreach, and policy levels. PMID:27616971

  5. Harmful Algal Blooms and Public Health.

    Science.gov (United States)

    Grattan, Lynn M; Holobaugh, Sailor; Morris, J Glenn

    2016-07-01

    The five most commonly recognized Harmful Algal Bloom related illnesses include Ciguatera poisoning, Paralytic Shellfish poisoning, Neurotoxin Shellfish poisoning, Diarrheic Shellfish Poisoning and Amnesic Shellfish poisoning. Although they are each the product of different toxins, toxin assemblages or HAB precursors these clinical syndromes have much in common. Exposure occurs through the consumption of fish or shellfish; routine clinical tests are not available for diagnosis; there is no known antidote for exposure; and the risk of these illnesses can negatively impact local fishing and tourism industries. Thus, illness prevention is of paramount importance to minimize human and public health risks. To accomplish this, close communication and collaboration is needed among HAB scientists, public health researchers and local, state and tribal health departments at academic, community outreach, and policy levels.

  6. Characterization of the microbial community in the rhizosphere of Phragmites australis (cav.) trin ex. steudel growing in the Sun Island Wetland.

    Science.gov (United States)

    Ma, Fang; Wu, Jieting; Wang, Li; Yang, Jixian; Li, Shiyang; Li, Zhe; Zhag, Xue

    2014-03-01

    Rhizospheric microorganisms are important for environmental conservancy. The constancy and variability of the microorganisms in the rhizosphere of Phragmites australis in relation to the spatiotemporal variations in wetland ecosystems were studied. During the peak and trough of the vegetative period of the Phragmites australis growing across the hydrologic gradients of the Sun Island Wetland, Biolog and denaturing gradient gel electrophoresis (DGGE) were used to investigate the rhizospheric microbial characteristics. Both methods demonstrated that the microbial activity, richness, and diversity decreased from summer to autumn. However, these properties did not show significant correlation with hydrologic gradient, except that the genetic richness and diversity of the fungi decreased with it. Cluster analysis also demonstrated that the rhizospheric microbial community seemed to be largely affected by a vegetative period. In addition, this research was extended to a broader range of determining the universal microorganisms, which showed notable adaptability.

  7. Algal biofuels: challenges and opportunities.

    Science.gov (United States)

    Leite, Gustavo B; Abdelaziz, Ahmed E M; Hallenbeck, Patrick C

    2013-10-01

    Biodiesel production using microalgae is attractive in a number of respects. Here a number of pros and cons to using microalgae for biofuels production are reviewed. Algal cultivation can be carried out using non-arable land and non-potable water with simple nutrient supply. In addition, algal biomass productivities are much higher than those of vascular plants and the extractable content of lipids that can be usefully converted to biodiesel, triacylglycerols (TAGs) can be much higher than that of the oil seeds now used for first generation biodiesel. On the other hand, practical, cost-effective production of biofuels from microalgae requires that a number of obstacles be overcome. These include the development of low-cost, effective growth systems, efficient and energy saving harvesting techniques, and methods for oil extraction and conversion that are environmentally benign and cost-effective. Promising recent advances in these areas are highlighted.

  8. Methods for removing contaminants from algal oil

    Energy Technology Data Exchange (ETDEWEB)

    Lupton, Francis Stephen

    2016-09-27

    Methods for removing contaminants from algal oil are provided. In an embodiment, a method comprises the steps of combining a sulfuric acid-aqueous solution that has a pH of about 1 or less with a contaminant-containing algal oil at treatment conditions effective to form an effluent. The effluent comprises a treated algal oil phase and contaminants in an acidic aqueous phase. The contaminants comprise metals, phosphorus, or combinations thereof. The acidic aqueous phase is removed from the effluent to form a contaminant-depleted algal oil.

  9. Algal Functional Annotation Tool: a web-based analysis suite to functionally interpret large gene lists using integrated annotation and expression data

    Directory of Open Access Journals (Sweden)

    Merchant Sabeeha S

    2011-07-01

    Full Text Available Abstract Background Progress in genome sequencing is proceeding at an exponential pace, and several new algal genomes are becoming available every year. One of the challenges facing the community is the association of protein sequences encoded in the genomes with biological function. While most genome assembly projects generate annotations for predicted protein sequences, they are usually limited and integrate functional terms from a limited number of databases. Another challenge is the use of annotations to interpret large lists of 'interesting' genes generated by genome-scale datasets. Previously, these gene lists had to be analyzed across several independent biological databases, often on a gene-by-gene basis. In contrast, several annotation databases, such as DAVID, integrate data from multiple functional databases and reveal underlying biological themes of large gene lists. While several such databases have been constructed for animals, none is currently available for the study of algae. Due to renewed interest in algae as potential sources of biofuels and the emergence of multiple algal genome sequences, a significant need has arisen for such a database to process the growing compendiums of algal genomic data. Description The Algal Functional Annotation Tool is a web-based comprehensive analysis suite integrating annotation data from several pathway, ontology, and protein family databases. The current version provides annotation for the model alga Chlamydomonas reinhardtii, and in the future will include additional genomes. The site allows users to interpret large gene lists by identifying associated functional terms, and their enrichment. Additionally, expression data for several experimental conditions were compiled and analyzed to provide an expression-based enrichment search. A tool to search for functionally-related genes based on gene expression across these conditions is also provided. Other features include dynamic visualization of

  10. Nested multiplex PCR--a feasible technique to study partial community of arbuscular mycorrhizal fungi in field-growing plant root.

    Science.gov (United States)

    Dong, Xiuli; Zhao, Bin

    2006-08-01

    Plant can be infected by different arbuscular mycorrhizal fungi, but little is known about the interaction between them within root tissues mainly because different species cannot be distinguished on the basis of fungal structure. Accurate species identification of Arbuscular mycorrhizal fungi (AMF) colonized in plant roots is the cornerstone of mycorrhizal study, yet this fundamental step is impossible through its morphological character alone. For accurate, rapid and inexpensive detection of partial mycorrhizal fungal community in plant roots, a nested multiplex polymerase chain reaction (PCR) was developed in this study. Five discriminating primers designed based on the variable region of the 5' end of the large ribosomal subunit were used in the experiment for testing their specificity and the sensitivity in nested PCR by using spores from Glomus mosseae (BEG12), Glomus intraradices (BEG141), Scutellospora castaneae (BEG1) and two unidentified Glomus sp. HAUO3 and HAUO4. The feasibility assay of nested multiplex PCR was conducted by use of spore mixture, Astragalus sinicum roots co-inoculated with 4 species of arbuscular mycorrhizal fungi from pot cultures and 15 different field-growing plant roots respectively after analyses of the compatibility of primers. The result indicated that the sensitivity was in the same range as that of the corresponding single PCR reaction. Overall accuracy was 95%. The efficiency and sensitivity of this multiplex PCR procedure provided a rapid and easy way to simultaneously detect several of arbuscular mycorrhiza fungal species in a same plant root system.

  11. Nested multiplex PCR——A feasible technique to study partial community of arbuscular mycorrhizal fungi in field-growing plant root

    Institute of Scientific and Technical Information of China (English)

    DONG Xiuli; ZHAO Bin

    2006-01-01

    Plant can be infected by different arbuscular mycorrhizal fungi, but little is known about the interaction between them within root tissues mainly because different species cannot be distinguished on the basis of fungal structure. Accurate species identification of Arbuscular mycorrhizal fungi (AMF) colonized in plant roots is the cornerstone of mycorrhizal study, yet this fundamental step is impossible through its morphological character alone. For accurate, rapid and inexpensive detection of partial mycorrhizal fungal community in plant roots, a nested multiplex polymerase chain reaction (PCR) was developed in this study. Five discriminating primers designed based on the variable region of the 5( end of the large ribosomal subunit were used in the experiment for testing their specificity and the sensitivity in nested PCR by using spores from Glomus mosseae (BEG12), Glomus intraradices (BEG141), Scutellospora castaneae (BEG1) and two unidentified Glomus sp. HAUO3 and HAUO4. The feasibility assay of nested multiplex PCR was conducted by use of spore mixture, Astragalus sinicum roots co-inoculated with 4 species of arbuscular mycorrhizal fungi from pot cultures and 15 different field-growing plant roots respectively after analyses of the compatibility of primers. The result indicated that the sensitivity was in the same range as that of the corresponding single PCR reaction. Overall accuracy was 95%. The efficiency and sensitivity of this multiplex PCR procedure provided a rapid and easy way to simultaneously detect several of arbuscular mycorrhizal fungal species in a same plant root system.

  12. Bacterial communities associated with the rhizosphere of pioneer plants (Bahia xylopoda and Viguiera linearis) growing on heavy metals-contaminated soils.

    Science.gov (United States)

    Navarro-Noya, Yendi E; Jan-Roblero, Janet; González-Chávez, Maria del Carmen; Hernández-Gama, Regina; Hernández-Rodríguez, César

    2010-05-01

    In this study, the bacterial communities associated with the rhizospheres of pioneer plants Bahia xylopoda and Viguiera linearis were explored. These plants grow on silver mine tailings with high concentration of heavy metals in Zacatecas, Mexico. Metagenomic DNAs from rhizosphere and bulk soil were extracted to perform a denaturing gradient gel electrophoresis analysis (DGGE) and to construct 16S rRNA gene libraries. A moderate bacterial diversity and twelve major phylogenetic groups including Proteobacteria, Acidobacteria, Bacteroidetes, Gemmatimonadetes, Chloroflexi, Firmicutes, Verrucomicrobia, Nitrospirae and Actinobacteria phyla, and divisions TM7, OP10 and OD1 were recognized in the rhizospheres. Only 25.5% from the phylotypes were common in the rhizosphere libraries and the most abundant groups were members of the phyla Acidobacteria and Betaproteobacteria (Thiobacillus spp., Nitrosomonadaceae). The most abundant groups in bulk soil library were Acidobacteria and Actinobacteria, and no common phylotypes were shared with the rhizosphere libraries. Many of the clones detected were related with chemolithotrophic and sulfur-oxidizing bacteria, characteristic of an environment with a high concentration of heavy metal-sulfur complexes, and lacking carbon and organic energy sources.

  13. NREL Algal Biofuels Projects and Partnerships

    Energy Technology Data Exchange (ETDEWEB)

    2016-10-01

    This fact sheet highlights several algal biofuels research and development projects focused on improving the economics of the algal biofuels production process. These projects should serve as a foundation for the research efforts toward algae as a source of fuels and other chemicals.

  14. Constraints to commercialization of algal fuels.

    Science.gov (United States)

    Chisti, Yusuf

    2013-09-10

    Production of algal crude oil has been achieved in various pilot scale facilities, but whether algal fuels can be produced in sufficient quantity to meaningfully displace petroleum fuels, has been largely overlooked. Limitations to commercialization of algal fuels need to be understood and addressed for any future commercialization. This review identifies the major constraints to commercialization of transport fuels from microalgae. Algae derived fuels are expensive compared to petroleum derived fuels, but this could change. Unfortunately, improved economics of production are not sufficient for an environmentally sustainable production, or its large scale feasibility. A low-cost point supply of concentrated carbon dioxide colocated with the other essential resources is necessary for producing algal fuels. An insufficiency of concentrated carbon dioxide is actually a major impediment to any substantial production of algal fuels. Sustainability of production requires the development of an ability to almost fully recycle the phosphorous and nitrogen nutrients that are necessary for algae culture. Development of a nitrogen biofixation ability to support production of algal fuels ought to be an important long term objective. At sufficiently large scale, a limited supply of freshwater will pose a significant limitation to production even if marine algae are used. Processes for recovering energy from the algal biomass left after the extraction of oil, are required for achieving a net positive energy balance in the algal fuel oil. The near term outlook for widespread use of algal fuels appears bleak, but fuels for niche applications such as in aviation may be likely in the medium term. Genetic and metabolic engineering of microalgae to boost production of fuel oil and ease its recovery, are essential for commercialization of algal fuels. Algae will need to be genetically modified for improved photosynthetic efficiency in the long term.

  15. Algal pigments in Southern Ocean abyssal foraminiferans indicate pelagobenthic coupling

    Science.gov (United States)

    Cedhagen, Tomas; Cheah, Wee; Bracher, Astrid; Lejzerowicz, Franck

    2014-10-01

    The cytoplasm of four species of abyssal benthic foraminiferans from the Southern Ocean (around 51°S; 12°W and 50°S; 39°W) was analysed by High Performance Liquid Chromatography (HPLC) and found to contain large concentrations of algal pigments and their degradation products. The composition of the algal pigments in the foraminiferan cytoplasm reflected the plankton community at the surface. Some foraminiferans contained high ratios of chlorophyll a/degraded pigments because they were feeding on fresher phytodetritus. Other foraminiferans contained only degraded pigments which shows that they utilized degraded phytodetritus. The concentration of algal pigment and corresponding degradation products in the foraminiferan cytoplasm is much higher than in the surrounding sediment. It shows that the foraminiferans collect a diluted and sparse food resource and concentrate it as they build up their cytoplasm. This ability contributes to the understanding of the great quantitative success of foraminiferans in the deep sea. Benthic foraminiferans are a food source for many abyssal metazoans. They form a link between the degraded food resources, phytodetritus, back to the active metazoan food chains.

  16. Growing Spaceships?

    Science.gov (United States)

    Robertson, Glen A.

    2013-01-01

    NASA currently has a program called the Space Synthetic Biology Project. Synthetic Biology or SynBio is the design and construction of new biological functions and systems not found in nature. Four NASA field centers, along with experts from industry and academia, have been partnering on the Space Synthetic Biology Project and are working on new breakthroughs in this increasingly useful pursuit, which is part a science discipline and part engineering. Led by researchers at NASA s Ames Research Center, the team is studying how this powerful new tool can help NASA now and in the future. The project was created to harness biology in reliable, robust, engineered systems to support the agency s exploration and science missions, to improve life on Earth and to help shape NASA's future. The program also is intended to contribute foundational tools to the synthetic biology research community.

  17. Algal Accessory Pigment Detection Using AVIRIS Image-Derived Spectral Radiance Data

    Science.gov (United States)

    Richardson, Laurie L.; Ambrosia, Vincent G.

    1996-01-01

    Visual and derivative analyses of AVIRIS spectral data can be used to detect algal accessory pigments in aquatic communities. This capability extends the use of remote sensing for the study of aquatic ecosystems by allowing detection of taxonomically significant pigment signatures which yield information about the type of algae present. Such information allows remote sensing-based assessment of aquatic ecosystem health, as in the detection of nuisance blooms of cyanobacteria or toxic blooms of dinoflagellates. Remote sensing of aquatic systems has traditionally focused on quantification of chlorophyll a, a photoreactive (and light-harvesting) pigment which is common to all algae as well as cyanobacteria (bluegreen algae). Due to the ubiquitousness of this pigment within algae, chl a is routinely measured to estimate algal biomass both during ground-truthing and using various airborne or satellite based sensors, including AVIRIS. Within the remote sensing and aquatic sciences communities, ongoing research has been performed to detect algal accessory pigments for assessment of algal population composition. This research is based on the fact that many algal accessory pigments are taxonomically significant, and all are spectrally unique. Aquatic scientists have been refining pigment analysis techniques, primarily high performance liquid chromatography, or HPLC, to detect specific pigments as a time-saving alternative to individual algal cell identifications and counts. Remote sensing scientists are investigating the use of pigment signatures to construct pigment libraries analogous to mineral spectral libraries used in geological remote sensing applications. The accessory pigment approach has been used successfully in remote sensing using data from the Thematic Mapper, low-altitude, multiple channel scanners, field spectroradiometers and the AVIRIS hyperspectral scanner. Due to spectral and spatial resolution capabilities, AVIRIS is the sensor of choice for such

  18. Growing Pains

    CERN Multimedia

    Katarina Anthony

    2013-01-01

    Heat expands and cold contracts: it’s a simple thermodynamic rule. But when temperatures swing from 300 K to near-absolute zero, this rule can mean a contraction of more than 80 metres across the LHC’s 27-km-long cryogenic system. Keeping this growth in check are compensators (a.k.a. bellows), which shrink and stretch in response to thermodynamic changes. Leak tests and X-rays now underway in the tunnel have revealed that these “joints” might be suffering from growing pains…   This 25-μm weld crack is thought to be the cause of the helium leaks. Prior to the LS1 warm-up, CERN’s cryogenic experts knew of two points in the machine’s cryogenic distribution system that were leaking helium. Fortunately, these leaks were sufficiently small, confined to known sub-sectors of the cryogenic line and – with help from the vacuum team (TE-VSC) – could easily be compensated for. But as the machine warmed up f...

  19. Methods for collecting algal samples as part of the National Water-Quality Assessment Program

    Science.gov (United States)

    Porter, Stephen D.; Cuffney, Thomas F.; Gurtz, Martin E.; Meador, Michael R.

    1993-01-01

    Benthic algae (periphyton) and phytoplankton communities are characterized in the U.S. Geological Survey's National Water-Quality Assessment Program as part of an integrated physical, chemical, and biological assessment of the Nation's water quality. This multidisciplinary approach provides multiple lines of evidence for evaluating water-quality status and trends, and for refining an understanding of the factors that affect water-quality conditions locally, regionally, and nationally. Water quality can be characterized by evaluating the results of qualitative and quantitative measurements of the algal community. Qualitative periphyton samples are collected to develop of list of taxa present in the sampling reach. Quantitative periphyton samples are collected to measure algal community structure within selected habitats. These samples of benthic algal communities are collected from natural substrates, using the sampling methods that are most appropriate for the habitat conditions. Phytoplankton samples may be collected in large nonwadeable streams and rivers to meet specific program objectives. Estimates of algal biomass (chlorophyll content and ash-free dry mass) also are optional measures that may be useful for interpreting water-quality conditions. A nationally consistent approach provides guidance on site, reach, and habitat selection, as well as information on methods and equipment for qualitative and quantitative sampling. Appropriate quality-assurance and quality-control guidelines are used to maximize the ability to analyze data locally, regionally, and nationally.

  20. Recent Advances in Algal Genetic Tool Development

    Energy Technology Data Exchange (ETDEWEB)

    R. Dahlin, Lukas; T. Guarnieri, Michael

    2016-06-24

    The goal of achieving cost-effective biofuels and bioproducts derived from algal biomass will require improvements along the entire value chain, including identification of robust, high-productivity strains and development of advanced genetic tools. Though there have been modest advances in development of genetic systems for the model alga Chlamydomonas reinhardtii, progress in development of algal genetic tools, especially as applied to non-model algae, has generally lagged behind that of more commonly utilized laboratory and industrial microbes. This is in part due to the complex organellar structure of algae, including robust cell walls and intricate compartmentalization of target loci, as well as prevalent gene silencing mechanisms, which hinder facile utilization of conventional genetic engineering tools and methodologies. However, recent progress in global tool development has opened the door for implementation of strain-engineering strategies in industrially-relevant algal strains. Here, we review recent advances in algal genetic tool development and applications in eukaryotic microalgae.

  1. Characteristics of Algal Succession Following Rock Scraping at Imwon Area in the East Coast of Korea

    Institute of Scientific and Technical Information of China (English)

    Young Dae Kim; Jung Kwan Ahn; Myung Mo Nam; Chu Lee; Hyun Il Yoo; Su Yeoung Yeon; Young Hwan Kim; Jang Kyun Kim; Jae Suk Choi

    2016-01-01

    This study was conducted to clarify the characteristics of algal succession following rock scraping using hoe or high-pressure water sprayer in the period from June 2010 to April 2011. We divided the research area off the eastern coast of Korean near Imwon into 3 categories depending upon the severity of the barren ground,i.e., the urchin barren-affected, urchin bar-ren-ongoing and urchin barren-free areas. In April 2011, in the urchin barren-affected area with 25 seaweed species, the cover per-centage and importance value (IV) of crustose coralline algae were higher than those of other species. In the urchin barren-ongoing area with 33 seaweed species, crustose coralline algae (mean IV=62%) as well asSargassumsp. (mean IV=28%), andGelidium amansii (mean IV=19%) were observed following rock scraping. In the urchin barren-free area where seaweed communities were relatively abundant with 42 species, a variety of algal species includingG. amansii (mean IV=32%) underwent algal succession. Overall, it was observed that, as an aspect of algal succession, the weaker the barren ground severity was, the more frequent and di-verse the seaweeds were, and the more complex the succession pattern was in the study. As an aspect of recovering algal community, rock scraping using hoe was shown to be superior to the method using high-pressure water spraying. Therefore, we conclude that rock scraping using hoe is a very effective strategy for recovering the algal community in urchin barren-ongoing area.

  2. Characteristics of algal succession following rock scraping at Imwon area in the east coast of Korea

    Science.gov (United States)

    Kim, Young Dae; Ahn, Jung Kwan; Nam, Myung Mo; Lee, Chu; Yoo, Hyun Il; Yeon, Su Yeoung; Kim, Young Hwan; Kim, Jang Kyun; Choi, Jae Suk

    2016-12-01

    This study was conducted to clarify the characteristics of algal succession following rock scraping using hoe or high-pressure water sprayer in the period from June 2010 to April 2011. We divided the research area off the eastern coast of Korean near Imwon into 3 categories depending upon the severity of the barren ground, i.e., the urchin barren-affected, urchin barren-ongoing and urchin barren-free areas. In April 2011, in the urchin barren-affected area with 25 seaweed species, the cover percentage and importance value (IV) of crustose coralline algae were higher than those of other species. In the urchin barren-ongoing area with 33 seaweed species, crustose coralline algae (mean IV = 62%) as well as Sargassum sp. (mean IV = 28%), and Gelidium amansii (mean IV = 19%) were observed following rock scraping. In the urchin barren-free area where seaweed communities were relatively abundant with 42 species, a variety of algal species including G. amansii (mean IV = 32%) underwent algal succession. Overall, it was observed that, as an aspect of algal succession, the weaker the barren ground severity was, the more frequent and diverse the seaweeds were, and the more complex the succession pattern was in the study. As an aspect of recovering algal community, rock scraping using hoe was shown to be superior to the method using high-pressure water spraying. Therefore, we conclude that rock scraping using hoe is a very effective strategy for recovering the algal community in urchin barren-ongoing area.

  3. Direct conversion of algal biomass to biofuel

    Science.gov (United States)

    Deng, Shuguang; Patil, Prafulla D; Gude, Veera Gnaneswar

    2014-10-14

    A method and system for providing direct conversion of algal biomass. Optionally, the method and system can be used to directly convert dry algal biomass to biodiesels under microwave irradiation by combining the reaction and combining steps. Alternatively, wet algae can be directly processed and converted to fatty acid methyl esters, which have the major components of biodiesels, by reacting with methanol at predetermined pressure and temperature ranges.

  4. Sustainable Production of Algal Biomass and Biofuels Using Swine Wastewater in North Carolina, US

    Directory of Open Access Journals (Sweden)

    Bo Zhang

    2016-05-01

    Full Text Available Algae were recently considered as a promising third-generation biofuel feedstock due to their superior productivity, high oil content, and environmentally friendly nature. However, the sustainable production became the major constraint facing commercial development of algal biofuels. For this study, firstly, a factorial experimental design was used to analyze the effects of the process parameters including temperatures of 8–25 °C, light intensity of 150–900 μmol·m−2s−1, and light duration of 6–24 h on the biomass yields of local alga Chlamydomonas debaryana in swine wastewater. The results were fitted with a quadratic equation (R2 = 0.9706. The factors of temperature, light duration, the interaction of light intensity-light duration, and the quadratic effect of temperature were statistically significant. When evaluating different scenarios for the sustainable production of algal biomass and biofuels in North Carolina, US, it showed that: (a Growing C. debaryana in a 10-acre pond on swine wastewater under local weather conditions would yield algal biomass of 113 tonnes/year; (b If all swine wastewater generated in North Carolina was treated with algae, it will require 137–485 acres of ponds, yielding biomass of 5048–10,468 tonnes/year and algal oil of 1010–2094 tonnes/year. Annually, hundreds of tonnes of nitrogen and phosphorus could be removed from swine wastewater. The required area is mainly dependent on the growth rate of algal species.

  5. Sterol phylogenesis and algal evolution

    Energy Technology Data Exchange (ETDEWEB)

    Nes, W.D.; Norton, R.A.; Crumley, F.G. (Richard B. Russell Research Center, Athens, GA (USA)); Madigan, S.J.; Katz, E.R. (State Univ. of New York at Stony Brook (USA))

    1990-10-01

    The stereochemistry of several sterol precursors and end products synthesized by two fungal-like microorganisms Prototheca wickerhamii (I) and Dictyostelium discoideum (II) have been determined by chromatographic (TLC, GLC, and HPLC) and spectral (UV, MS, and {sup 1}H NMR) methods. From I and II the following sterols were isolated from the cells: cycloartenol, cyclolaudenol, 24(28)-methylenecy-cloartanol, ergosterol, protothecasterol, 4{alpha}-methylergostanol, 4{alpha}-methylclionastanol, clionastanol, 24{beta}-ethylcholesta-8,22-enol, and dictyosterol. In addition, the mechanism of C-24 methylation was investigated in both organisms by feeding to I (2-{sup 3}H)lanosterol, (2-{sup 3}H)cycloartenol, (24{sup 3}H)lanosterol, and (methyl-{sup 2}H{sub 3})methionine and by feeding to II (methyl-{sup 2}H{sub 3})methionine. The results demonstrate that the 24{beta} configuration is formed by different alkylation routes in I and II. The authors conclude that Prototheca is an apoplastic Chlorella (i.e., an alga) and that Dictyostelium as well as the other soil amoebae that synthesize cycloartenol evolved from algal rather than fungal ancestors.

  6. Towards developing algal synthetic biology.

    Science.gov (United States)

    Scaife, Mark Aden; Smith, Alison Gail

    2016-06-15

    The genetic, physiological and metabolic diversity of microalgae has driven fundamental research into photosynthesis, flagella structure and function, and eukaryotic evolution. Within the last 10 years these organisms have also been investigated as potential biotechnology platforms, for example to produce high value compounds such as long chain polyunsaturated fatty acids, pigments and antioxidants, and for biodiesel precursors, in particular triacylglycerols (TAGs). Transformation protocols, molecular tools and genome sequences are available for a number of model species including the green alga Chlamydomonas reinhardtii and the diatom Phaeodactylum tricornutum, although for both species there are bottlenecks to be overcome to allow rapid and predictable genetic manipulation. One approach to do this would be to apply the principles of synthetic biology to microalgae, namely the cycle of Design-Build-Test, which requires more robust, predictable and high throughput methods. In this mini-review we highlight recent progress in the areas of improving transgene expression, genome editing, identification and design of standard genetic elements (parts), and the use of microfluidics to increase throughput. We suggest that combining these approaches will provide the means to establish algal synthetic biology, and that application of standard parts and workflows will avoid parallel development and capitalize on lessons learned from other systems.

  7. Baseline characterization of benthic and coral communities of the Flower Garden Banks (2010 - 2012) (NODC Accession 0124257)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study utilized ROV photograph transects to quantify benthic habitat and coral communities among the five habitat types (algal nodule, coralline algal reefs,...

  8. Algal Supply System Design - Harmonized Version

    Energy Technology Data Exchange (ETDEWEB)

    Jared Abodeely; Daniel Stevens; Allison Ray; Debor

    2013-03-01

    The objective of this design report is to provide an assessment of current technologies used for production, dewatering, and converting microalgae cultivated in open-pond systems to biofuel. The original draft design was created in 2011 and has subsequently been brought into agreement with the DOE harmonized model. The design report extends beyond this harmonized model to discuss some of the challenges with assessing algal production systems, including the ability to (1) quickly assess alternative algal production system designs, (2) assess spatial and temporal variability, and (3) perform large-scale assessments considering multiple scenarios for thousands of potential sites. The Algae Logistics Model (ALM) was developed to address each of these limitations of current modeling efforts to enable assessment of the economic feasibility of algal production systems across the United States. The (ALM) enables (1) dynamic assessments using spatiotemporal conditions, (2) exploration of algal production system design configurations, (3) investigation of algal production system operating assumptions, and (4) trade-off assessments with technology decisions and operating assumptions. The report discusses results from the ALM, which is used to assess the baseline design determined by harmonization efforts between U.S. DOE national laboratories. Productivity and resource assessment data is provided by coupling the ALM with the Biomass Assessment Tool developed at PNNL. This high-fidelity data is dynamically passed to the ALM and used to help better understand the impacts of spatial and temporal constraints on algal production systems by providing a cost for producing extracted algal lipids annually for each potential site.

  9. Algal Energy Conversion and Capture

    Science.gov (United States)

    Hazendonk, P.

    2015-12-01

    We address the potential for energy conversions and capture for: energy generation; reduction in energy use; reduction in greenhouse gas emissions; remediation of water and air pollution; protection and enhancement of soil fertility. These processes have the potential to sequester carbon at scales that may have global impact. Energy conversion and capture strategies evaluate energy use and production from agriculture, urban areas and industries, and apply existing and emerging technologies to reduce and recapture energy embedded in waste products. The basis of biocrude production from Micro-algal feedstocks: 1) The nutrients from the liquid fraction of waste streams are concentrated and fed into photo bioreactors (essentially large vessels in which microalgae are grown) along with CO2 from flue gasses from down stream processes. 2) The algae are processed to remove high value products such as proteins and beta-carotenes. The advantage of algae feedstocks is the high biomass productivity is 30-50 times that of land based crops and the remaining biomass contains minimal components that are difficult to convert to biocrude. 3) The remaining biomass undergoes hydrothermal liquefaction to produces biocrude and biochar. The flue gasses of this process can be used to produce electricity (fuel cell) and subsequently fed back into the photobioreactor. The thermal energy required for this process is small, hence readily obtained from solar-thermal sources, and furthermore no drying or preprocessing is required keeping the energy overhead extremely small. 4) The biocrude can be upgraded and refined as conventional crude oil, creating a range of liquid fuels. In principle this process can be applied on the farm scale to the municipal scale. Overall, our primary food production is too dependent on fossil fuels. Energy conversion and capture can make food production sustainable.

  10. Algal and microbial exopolysaccharides: new insights as biosurfactants and bioemulsifiers.

    Science.gov (United States)

    Paniagua-Michel, José de Jesús; Olmos-Soto, Jorge; Morales-Guerrero, Eduardo Roberto

    2014-01-01

    Currently, efforts are being made to utilize more natural biological systems as alternatives as a way to replace fossil forms of carbon. There is a growing concern at global level to have nontoxic, nonhazardous surface-active agents; contrary to synthetic surfactants, their biological counterparts or biosurfactants play a primary function, facilitating microbial presence in environments dominated by hydrophilic-hydrophobic interfaces. Algal and microbial biosurfactants/bioemulsifiers from marine and deep-sea environments are attracting major interest due to their structural and functional diversity as molecules actives of surface and an alternative biomass to replace fossil forms of carbon. Algal and microbial surfactants are lipid in nature and classified as glycolipids, phospholipids, lipopeptides, natural lipids, fatty acids, and lipopolysaccharides. These metabolic bioactive products are applicable in a number of industries and processes, viz., food processing, pharmacology, and bioremediation of oil-polluted environments. This chapter presents an update of the progress and potentialities of the principal producers of exopolysaccharide (EPS)-type biosurfactants and bioemulsifiers, viz., macro- and microalgae (cyanobacteria and diatoms) and bacteria from marine and extreme environments. Particular interest is centered into new sources and applications, viz., marine and deep-sea environments and promissory uses of these EPSs as biosurfactants/emulsifiers and other polymeric roles. The enormous benefits of these molecules encourage their discovery, exploitation, and development of new microbial EPSs that could possess novel industrial importance and corresponding innovations.

  11. Endogenous viral elements in algal genomes

    Institute of Scientific and Technical Information of China (English)

    WANG Liang; YU Jun; WU Shuangxiu; LIU Tao; SUN Jing; CHI Shan; LIU Cui; LI Xingang; YIN Jinlong; WANG Xumin

    2014-01-01

    Endogenous viral elements (EVEs) are host-genomic fragments originated from viral genomes. They have been found universally in animal and plant genomes. Here we carried out a systematic screening and analy-sis of EVEs in algal genomes and found that EVEs commonly exist in algal genomes. We classified the EVE fragments into three categories according to the length of EVE fragments. Due to the probability of sequence similarity by chance, we ignored the potential function of medium-length EVE fragments. However, long-length EVE fragments probably had capability to encode protein domains or even entire proteins, and some short-length EVE fragments had high similarity with host's siRNA sequences and possibly served functions of small RNAs. Therefore, short and long EVE fragments might provide regulomic and proteomic novelty to the host's metabolism and adaptation. We also found several EVE fragments shared by more than 3 algal genomes. By phylogenetic analysis of the shared EVEs and their corresponding species, we found that the integration of viral fragments into host genomes was an ancient event, possibly before the divergence of Chlorophytes and Ochrophytes. Our findings show that there is a frequent genetic flow from viruses to algal genomes. Moreover, study on algal EVEs shed light on the virus-host interaction in large timescale and could also help us understand the balance of marine ecosystems.

  12. Periphytic algal community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Paraná State, Brazil = Comunidade de algas perifíticas em substrato artificial e natural em um tributário do reservatório de Rosana (Ribeirão do Corvo, Estado do Paraná, Brasil

    Directory of Open Access Journals (Sweden)

    Liliana Rodrigues

    2010-10-01

    Full Text Available Periphytic algal community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Paraná State, Brazil. This study evaluated the heterogeneity in periphytic algal community, under the influence of time colonization on artificial substratum. We also examined which abiotic variables most influenced the community in natural and artificial substratum. Egeria najas Planchon was used as natural substratum, and a plastic plant, asartificial. This experiment was carried out in a lateral arm from Rosana Reservoir, formed by Corvo Stream (Paranapanema river basin, in the period from November 21st to December 12nd, 2003, characterized as a warm and rainy period. Changes in species composition were assessed using the similarity indices. 495 taxa were registered in the phycoperiphytic community, distributed in 133 genera and 11 classes. Zygnemaphyceae, Bacillariophyceae, Chlorophyceae and Cyanophyceae presented higher species number, in both substrata. Staurodesmus, Closterium, Staurastrum and Cosmarium (Desmidiales; Gomphonema and Eunotia (Pennales; Characium, Scenedesmus and Desmodesmus (Chlorococcales; Anabaena and Aphanocapsa (Nostocales and Chroococcales, respectively were the most species-rich genera. The epiphytic community reached the highest species richness in the 15th successional day. Regardless the substratum type, the number of species was probably related to the high concentrations of nutrients (phosphorus and nitrogen.Este trabalho objetivou analisar a composição da comunidade de algas perifíticas sob influência do tempo de colonização em substrato artificial. Ainda procurou responder quais variáveis abióticas mais influenciaram na comunidade em substrato artificial e natural. Utilizou-se Egeria najas Planchon como substrato natural e planta de plástico semelhante à Egeria como artificial. O experimento foi realizado no rio do Corvo, tributário do reservatório de Rosana (bacia do Paranapanema

  13. Algal Biology Toolbox Workshop Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2016-08-01

    DOE-EERE's Bioenergy Technologies Office (BETO) works to accelerate the development of a sustainable, cost-competitive, advanced biofuel industry that can strengthen U.S. energy security, environmental quality, and economic vitality, through research, development, and demonstration projects in partnership with industry, academia, and national laboratory partners. BETO’s Advanced Algal Systems Program (also called the Algae Program) has a long-term applied research and development (R&D) strategy to increase the yields and lower the costs of algal biofuels. The team works with partners to develop new technologies, to integrate technologies at commercially relevant scales, and to conduct crosscutting analyses to better understand the potential and challenges of the algal biofuels industry. Research has indicated that this industry is capable of producing billions of gallons of renewable diesel, gasoline, and jet fuels annually. R&D activities are integrated with BETO’s longstanding effort to accelerate the commercialization of lignocellulosic biofuels.

  14. Environmental and Health Effects Associated With Harmful Algal Bloom and Marine Algal Toxins in China

    Institute of Scientific and Technical Information of China (English)

    TIAN YAN; MING-JIANG ZHOU

    2004-01-01

    The frequency and scale of Harmful Algal Bloom (HAB) and marine algal toxin incidents have been increasing and spreading in the past two decades, causing damages to the marine environment and threatening human life through contaminated seafood. To better understand the effect of HAB and marine algal toxins on marine environment and human health in China, this paper overviews HAB occurrence and marine algal toxin incidents, as well as their environmental and health effects in this country. HAB has been increasing rapidly along the Chinese coast since the 1970s, and at least 512 documented HAB events have occurred from 1952 to 2002 in the Chinese mainland. It has been found that PSP and DSP toxins are distributed widely along both the northern and southern Chinese coasts. The HAB and marine algal toxin events during the 1990s in China were summarized, showing that the HAB and algal toxins resulted in great damages to local fisheries, marine culture, quality of marine environment, and human health. Therefore, to protect the coastal environment and human health, attention to HAB and marine algal toxins is urgently needed from the environmental and epidemiological view.

  15. Algal recycling enhances algal productivity and settleability in Pediastrum boryanum pure cultures.

    Science.gov (United States)

    Park, Jason B K; Craggs, Rupert J; Shilton, Andy N

    2015-12-15

    Recycling a portion of gravity harvested algae (i.e. algae and associated bacteria biomass) has been shown to improve both algal biomass productivity and harvest efficiency by maintaining the dominance of a rapidly-settleable colonial alga, Pediastrum boryanum in both pilot-scale wastewater treatment High Rate Algal Ponds (HRAP) and outdoor mesocosms. While algal recycling did not change the relative proportions of algae and bacteria in the HRAP culture, the contribution of the wastewater bacteria to the improved algal biomass productivity and settleability with the recycling was not certain and still required investigation. P. boryanum was therefore isolated from the HRAP and grown in pure culture on synthetic wastewater growth media under laboratory conditions. The influence of recycling on the productivity and settleability of the pure P. boryanum culture was then determined without wastewater bacteria present. Six 1 L P. boryanum cultures were grown over 30 days in a laboratory growth chamber simulating New Zealand summer conditions either with (Pr) or without (Pc) recycling of 10% of gravity harvested algae. The cultures with recycling (Pr) had higher algal productivity than the controls (Pc) when the cultures were operated at both 4 and 3 d hydraulic retention times by 11% and 38% respectively. Furthermore, algal recycling also improved 1 h settleability from ∼60% to ∼85% by increasing the average P. boryanum colony size due to the extended mean cell residence time and promoted formation of large algal bio-flocs (>500 μm diameter). These results demonstrate that the presence of wastewater bacteria was not necessary to improve algal productivity and settleability with algal recycling.

  16. Priming in the microbial landscape: periphytic algal stimulation of litter-associated microbial decomposers.

    Science.gov (United States)

    Kuehn, Kevin A; Francoeur, Steven N; Findlay, Robert H; Neely, Robert K

    2014-03-01

    Microbial communities associated with submerged detritus in aquatic ecosystems often comprise a diverse mixture of autotrophic and heterotrophic microbes, including algae, bacteria, protozoa, and fungi. Recent studies have documented increased rates of plant litter mass loss when periphytic algae are present. We conducted laboratory and field experiments to assess potential metabolic interactions between natural autotrophic and heterotrophic microbial communities inhabiting submerged decaying plant litter of Typha angustifolia and Schoenoplectus acutus. In the field, submerged plant litter was either exposed to natural sunlight or placed under experimental canopies that manipulated light availability and growth of periphytic algae. Litter was collected and returned to the laboratory, where algal photosynthesis was manipulated (light/dark incubation), while rates of bacterial and fungal growth and productivity were simultaneously quantified. Bacteria and fungi were rapidly stimulated by exposure to light, thus establishing the potential for algal priming of microbial heterotrophic decay activities. Experimental incubations of decaying litter with 14C- and 13C-bicarbonate established that inorganic C fixed by algal photosynthesis was rapidly transferred to and assimilated by heterotrophic microbial decomposers. Periphytic algal stimulation of microbial heterotrophs, especially fungal decomposers, is an important and largely unrecognized interaction within the detrital microbial landscape, which may transform our current conceptual understanding of microbial secondary production and organic matter decomposition in aquatic ecosystems.

  17. Exploiting diversity and synthetic biology for the production of algal biofuels.

    Science.gov (United States)

    Georgianna, D Ryan; Mayfield, Stephen P

    2012-08-16

    Modern life is intimately linked to the availability of fossil fuels, which continue to meet the world's growing energy needs even though their use drives climate change, exhausts finite reserves and contributes to global political strife. Biofuels made from renewable resources could be a more sustainable alternative, particularly if sourced from organisms, such as algae, that can be farmed without using valuable arable land. Strain development and process engineering are needed to make algal biofuels practical and economically viable.

  18. Algal Bloom in Aquatic Ecosystems-an Overview

    OpenAIRE

    M. Ghorbani; S.A. Mirbagheri; A. H. Hasani; S. M. Monavari; J.Nouri

    2014-01-01

    Algae play an important role in all aquatic ecosystems by providing all living organisms of water bodies with preliminary nutrients and energy required. However, abnormal and excessive algal growth so-called algal bloom would be detrimental as much. Given the importance of algae in aquatic environment as well as their sensitivity to environmental changes, algal measurements are of key components of water quality monitoring programs. The algal blooms could include a variety of adverse impacts...

  19. Baseline characterization of benthic and coral communities of the Flower Garden Banks, Texas from 2010-05-01 to 2012-08-31 (NODC Accession 0124257)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study utilized ROV photograph transects to quantify benthic habitat and coral communities among the five habitat types (algal nodule, coralline algal reefs,...

  20. Resolving Mixed Algal Species in Hyperspectral Images

    Directory of Open Access Journals (Sweden)

    Mehrube Mehrubeoglu

    2013-12-01

    Full Text Available We investigated a lab-based hyperspectral imaging system’s response from pure (single and mixed (two algal cultures containing known algae types and volumetric combinations to characterize the system’s performance. The spectral response to volumetric changes in single and combinations of algal mixtures with known ratios were tested. Constrained linear spectral unmixing was applied to extract the algal content of the mixtures based on abundances that produced the lowest root mean square error. Percent prediction error was computed as the difference between actual percent volumetric content and abundances at minimum RMS error. Best prediction errors were computed as 0.4%, 0.4% and 6.3% for the mixed spectra from three independent experiments. The worst prediction errors were found as 5.6%, 5.4% and 13.4% for the same order of experiments. Additionally, Beer-Lambert’s law was utilized to relate transmittance to different volumes of pure algal suspensions demonstrating linear logarithmic trends for optical property measurements.

  1. Growing up and Growing Old: Communities in Counterpoint

    Science.gov (United States)

    St John, Patricia A.

    2009-01-01

    Using a socio-cultural lens, this study explores two unique populations participating in an intergenerational music experience: seven infants/caregivers (ages 3-16 months) and eight retired women religious (ages 70-94). I was curious to examine how music-making across ages might facilitate new-found meaning for old people whilst simultaneously…

  2. Recent progress and future challenges in algal biofuel production [version 1; referees: 4 approved

    Directory of Open Access Journals (Sweden)

    Jonathan B. Shurin

    2016-10-01

    Full Text Available Modern society is fueled by fossil energy produced millions of years ago by photosynthetic organisms. Cultivating contemporary photosynthetic producers to generate energy and capture carbon from the atmosphere is one potential approach to sustaining society without disrupting the climate. Algae, photosynthetic aquatic microorganisms, are the fastest growing primary producers in the world and can therefore produce more energy with less land, water, and nutrients than terrestrial plant crops. We review recent progress and challenges in developing bioenergy technology based on algae. A variety of high-value products in addition to biofuels can be harvested from algal biomass, and these may be key to developing algal biotechnology and realizing the commercial potential of these organisms. Aspects of algal biology that differentiate them from plants demand an integrative approach based on genetics, cell biology, ecology, and evolution. We call for a systems approach to research on algal biotechnology rooted in understanding their biology, from the level of genes to ecosystems, and integrating perspectives from physical, chemical, and social sciences to solve one of the most critical outstanding technological problems.

  3. Algal toxins alter copepod feeding behavior.

    Directory of Open Access Journals (Sweden)

    Jiarong Hong

    Full Text Available Using digital holographic cinematography, we quantify and compare the feeding behavior of free-swimming copepods, Acartia tonsa, on nutritional prey (Storeatula major to that occurring during exposure to toxic and non-toxic strains of Karenia brevis and Karlodinium veneficum. These two harmful algal species produce polyketide toxins with different modes of action and potency. We distinguish between two different beating modes of the copepod's feeding appendages-a "sampling beating" that has short durations (<100 ms and involves little fluid entrainment and a longer duration "grazing beating" that persists up to 1200 ms and generates feeding currents. The durations of both beating modes have log-normal distributions. Without prey, A. tonsa only samples the environment at low frequency. Upon introduction of non-toxic food, it increases its sampling time moderately and the grazing period substantially. On mono algal diets for either of the toxic dinoflagellates, sampling time fraction is high but the grazing is very limited. A. tonsa demonstrates aversion to both toxic algal species. In mixtures of S. major and the neurotoxin producing K. brevis, sampling and grazing diminish rapidly, presumably due to neurological effects of consuming brevetoxins while trying to feed on S. major. In contrast, on mixtures of cytotoxin producing K. veneficum, both behavioral modes persist, indicating that intake of karlotoxins does not immediately inhibit the copepod's grazing behavior. These findings add critical insight into how these algal toxins may influence the copepod's feeding behavior, and suggest how some harmful algal species may alter top-down control exerted by grazers like copepods.

  4. Algal MIPs, high diversity and conserved motifs

    Directory of Open Access Journals (Sweden)

    Johanson Urban

    2011-04-01

    Full Text Available Abstract Background Major intrinsic proteins (MIPs also named aquaporins form channels facilitating the passive transport of water and other small polar molecules across membranes. MIPs are particularly abundant and diverse in terrestrial plants but little is known about their evolutionary history. In an attempt to investigate the origin of the plant MIP subfamilies, genomes of chlorophyte algae, the sister group of charophyte algae and land plants, were searched for MIP encoding genes. Results A total of 22 MIPs were identified in the nine analysed genomes and phylogenetic analyses classified them into seven subfamilies. Two of these, Plasma membrane Intrinsic Proteins (PIPs and GlpF-like Intrinsic Proteins (GIPs, are also present in land plants and divergence dating support a common origin of these algal and land plant MIPs, predating the evolution of terrestrial plants. The subfamilies unique to algae were named MIPA to MIPE to facilitate the use of a common nomenclature for plant MIPs reflecting phylogenetically stable groups. All of the investigated genomes contained at least one MIP gene but only a few species encoded MIPs belonging to more than one subfamily. Conclusions Our results suggest that at least two of the seven subfamilies found in land plants were present already in an algal ancestor. The total variation of MIPs and the number of different subfamilies in chlorophyte algae is likely to be even higher than that found in land plants. Our analyses indicate that genetic exchanges between several of the algal subfamilies have occurred. The PIP1 and PIP2 groups and the Ca2+ gating appear to be specific to land plants whereas the pH gating is a more ancient characteristic shared by all PIPs. Further studies are needed to discern the function of the algal specific subfamilies MIPA-E and to fully understand the evolutionary relationship of algal and terrestrial plant MIPs.

  5. Influence of resting and pine sawdust application on chemical changes in post-agricultural soil and the ectomycorrhizal community of growing Scots pine saplings

    Directory of Open Access Journals (Sweden)

    Małecka Monika

    2015-09-01

    Full Text Available Changes in chemical compounds and in ectomycorrhizal structure were determined for Scots pine growing on post agricultural soil lying fallow for 3, 6 and 15 years, after amendment with pine sawdust. Soil without any amendments was used as the control treatment. Comparing the ectomycorrhizal structure 15 years after the application of pine sawdust revealed no significant differences in abundance or species richness between soil with and without organic enrichment. The results showed that the ectomycorrhizal status depends on soil conditions (soil pH, nitrogen content, which remain unaffected by saw dust application. In all treatments, the most frequently occurring ectomycorrhizae genera were Dermocybe, Hebeloma, Suillus, Tomentella and Tricholoma. Two species (Paxillus involutus, Amanita muscaria were specific to the control plots that lay fallow for 15 years.

  6. Drifting algal mats as an alternative habitat for benthic invertebrates: Species specific responses to a transient resource.

    Science.gov (United States)

    Norkko; Bonsdorff; Norkko

    2000-05-18

    Patchy occurrences of benthic drift algae (i.e. loose lying macroalgal mats) may increase habitat complexity on normally bare soft bottoms, but at the same time, extensive amounts of drifting algal mats are known to stress the benthic fauna. This paper presents results of the first detailed study of the fauna associated with drift algal mats in the northern Baltic Sea. In order to assess the importance of drifting algae as an alternative habitat for benthic fauna, benthic drift algal mats were sampled on shallow (2-9 m) sandy soft bottoms in the outer archipelago of the Åland Islands (Finland). Species composition, abundance and biomass of the macrofauna associated with algal mats were recorded. The results show that drifting algae at times can harbour very high abundances of invertebrates (up to 1116 individuals/g algal dryweight), surpassing invertebrate densities recorded in seagrass communities. The algal fauna varied between sites and over time, and factors such as ambient benthic fauna, exposure to wind-wave disturbance, depth, and algal coverage and condition influenced the invertebrate community composition of the algal mats. Abundance increased while individual biomass of the animals decreased over time (summer season; July-October). A series of laboratory experiments were conducted in order to test the ability of a few important benthic species to move up into, and survive in a drifting algal mat. Macoma balthica, Hydrobia spp., Nereis diversicolor and Bathyporeia pilosa were used in the experiments, and significant differences in their survival and mobility within drifting algae were recorded. This study shows that benthic species differ significantly in their ability to utilise the algal mats, with mainly opportunistic and mobile taxa such as Hydrobia spp., Chironomidae and Ostracoda benefiting from the algae, whereas infaunal species such as M. balthica and B. pilosa are negatively affected. The occurrence of eutrophication induced drifting macroalgal

  7. 淀山湖水华高发期浮游植物群落变化特征研究%Characteristics of Phytoplankton Community Changes in Dianshan Lake During Peak Period of Algal Blooms

    Institute of Scientific and Technical Information of China (English)

    徐春燕; 杨洁; 马明睿; 胡雪芹; 由文辉

    2012-01-01

    Based on the investigation data of phytoplankton in Dianshan Lake from May to October in 2009,the characteristics of phytoplankton community and the dominant species succession are studied.The results show that Cyanophyta and Chlorophta are the main taxa.Cyanophyta is dominant in cell abundance and Chlorophta is dominant in species variety.From the flat distribution,the species variety and density of Cyanophyta are higher in west and southwest.The peak of cell density reaches 23.40×107 cells·L-1 in September due to the occurrence of cyanobacterial bloom,Cyanophyta account for 90.3 percents,with significant differences in each point(ANOVA,P0.05).An obvious succession of phytoplankton species is found,Microcystis of Cyanophyta become the dominant taxa and then conglutinated together to form water bloom.Temperature and pH are the main factors that affect the cyanobacterial bloom,and wind direction is an important reason for the horizontal distribution of the bloom-forming Microcystis.The phytoplankton diversity index is poor in central and western sites,diversity index decreases during cyanobacterial bloom and the community structures are simple.%根据2009年5~10月淀山湖浮游植物数量和种类的观测结果,对水华高发季节浮游植物群落组成特点及优势种交替过程进行分析,初步探讨这一时期浮游植物群落特征与环境因子的关系.结果表明,这一时期浮游植物主要由蓝藻和绿藻组成,蓝藻在密度上、绿藻在种类上占优势.水平分布上,西部和西南部的蓝藻密度值和种类数较高.总密度最高峰出现在9月,其值为23.40×107cells.L-1,其中蓝藻数量占90.3%,各样点间总密度差异显著(ANOVA,P〈0.05).优势种在调查期间存在明显的交替现象,蓝藻门微囊藻属(Microcystis)藻类逐步成为优势种并形成水华.水温与pH是影响水华发生的重要环境因子,微囊藻受风向影响容易向下风向水域聚集形成水华.淀山湖

  8. Application of a GIS-AF/RF model to assess the risk of herbicide leaching in a citrus-growing area of the Valencia Community, Spain.

    Science.gov (United States)

    de Paz, José M; Rubio, José L

    2006-12-01

    We integrated an index-based attenuation factor/retardation factor (AF/RF) model into a GIS to evaluate the risk of leaching of the most frequently applied herbicides (glyphosate, diuron, diquat, bromacil, simazine, linuron, terbuthylazine, and terbumeton) used in citrus orchards of the Valencia Community, Spain. The GIS-model system was applied to a region of 33,800 ha located near Valencia City. The soil and climate data required by the model were stored in an Arc/Info GIS in which the model algorithms were integrated using the AML programming language. A graphical user interface was developed to facilitate the use of the GIS-model system. The resulting simulation maps indicate that terbumeton, bromacil, and simazine herbicides have the highest risk of leaching because of their high mobility and low K(oc) (32-158 mg l(-1)). The remaining herbicides are strongly adsorbed by clay particles and organic matter, thus minimising the risk of leaching through the soil profile and into groundwater. The obtained ranking of the leaching potential of analysed herbicides is as follows, from highest to lowest risk: terbumeton>bromacil>simazine>terbuthylazine>diuron>linuron>glyphosate>diquat.

  9. Life Cycle Analysis on Fossil Energy Ratio of Algal Biodiesel: Effects of Nitrogen Deficiency and Oil Extraction Technology

    Directory of Open Access Journals (Sweden)

    Hou Jian

    2015-01-01

    Full Text Available Life cycle assessment (LCA has been widely used to analyze various pathways of biofuel preparation from “cradle to grave.” Effects of nitrogen supply for algae cultivation and technology of algal oil extraction on life cycle fossil energy ratio of biodiesel are assessed in this study. Life cycle fossil energy ratio of Chlorella vulgaris based biodiesel is improved by growing algae under nitrogen-limited conditions, while the life cycle fossil energy ratio of biodiesel production from Phaeodactylum tricornutum grown with nitrogen deprivation decreases. Compared to extraction of oil from dried algae, extraction of lipid from wet algae with subcritical cosolvents achieves a 43.83% improvement in fossil energy ratio of algal biodiesel when oilcake drying is not considered. The outcome for sensitivity analysis indicates that the algal oil conversion rate and energy content of algae are found to have the greatest effects on the LCA results of algal biodiesel production, followed by utilization ratio of algal residue, energy demand for algae drying, capacity of water mixing, and productivity of algae.

  10. Life cycle analysis on fossil energy ratio of algal biodiesel: effects of nitrogen deficiency and oil extraction technology.

    Science.gov (United States)

    Jian, Hou; Jing, Yang; Peidong, Zhang

    2015-01-01

    Life cycle assessment (LCA) has been widely used to analyze various pathways of biofuel preparation from "cradle to grave." Effects of nitrogen supply for algae cultivation and technology of algal oil extraction on life cycle fossil energy ratio of biodiesel are assessed in this study. Life cycle fossil energy ratio of Chlorella vulgaris based biodiesel is improved by growing algae under nitrogen-limited conditions, while the life cycle fossil energy ratio of biodiesel production from Phaeodactylum tricornutum grown with nitrogen deprivation decreases. Compared to extraction of oil from dried algae, extraction of lipid from wet algae with subcritical cosolvents achieves a 43.83% improvement in fossil energy ratio of algal biodiesel when oilcake drying is not considered. The outcome for sensitivity analysis indicates that the algal oil conversion rate and energy content of algae are found to have the greatest effects on the LCA results of algal biodiesel production, followed by utilization ratio of algal residue, energy demand for algae drying, capacity of water mixing, and productivity of algae.

  11. Copper desorption from Gelidium algal biomass.

    Science.gov (United States)

    Vilar, Vítor J P; Botelho, Cidália M S; Boaventura, Rui A R

    2007-04-01

    Desorption of divalent copper from marine algae Gelidium sesquipedale, an algal waste (from agar extraction industry) and a composite material (the algal waste immobilized in polyacrylonitrile) was studied in a batch system. Copper ions were first adsorbed until saturation and then desorbed by HNO(3) and Na(2)EDTA solutions. Elution efficiency using HNO(3) increases as pH decreases. At pH=1, for a solid to liquid ratio S/L=4gl(-1), elution efficiency was 97%, 95% and 88%, the stoichiometric coefficient for the ionic exchange, 0.70+/-0.02, 0.73+/-0.05 and 0.76+/-0.06 and the selectivity coefficient, 0.93+/-0.07, 1.0+/-0.3 and 1.1+/-0.3, respectively, for algae Gelidium, algal waste and composite material. Complexation of copper ions by EDTA occurs in a molar proportion of 1:1 and the elution efficiency increases with EDTA concentration. For concentrations of 1.4, 0.88 and 0.57 mmoll(-1), the elution efficiency for S/L=4gl(-1), was 91%, 86% and 78%, respectively, for algae Gelidium, algal waste and composite material. The S/L ratio, in the range 1-20gl(-1), has little influence on copper recovery by using 0.1M HNO(3). Desorption kinetics was very fast for all biosorbents. Kinetic data using HNO(3) as eluant were well described by the mass transfer model, considering the average metal concentration in the solid phase and the equilibrium relationship given by the mass action law. The homogeneous diffusion coefficient varied between 1.0 x 10(-7)cm(2)s(-1) for algae Gelidium and 3.0 x 10(-7)cm(2)s(-1) for the composite material.

  12. Collection and conversion of algal lipid

    Science.gov (United States)

    Lin, Ching-Chieh

    Sustainable economic activities mandate a significant replacement of fossil energy by renewable forms. Algae-derived biofuels are increasingly seen as an alternative source of energy with potential to supplement the world's ever increasing demand. Our primary objective is, once the algae were cultivated, to eliminate or make more efficient energy-intensive processing steps of collection, drying, grinding, and solvent extraction prior to conversion. To overcome the processing barrier, we propose to streamline from cultivated algae to biodiesel via algal biomass collection by sand filtration, cell rupturing with ozone, and immediate transesterification. To collect the algal biomass, the specific Chlorococcum aquaticum suspension was acidified to pH 3.3 to promote agglomeration prior to sand filtration. The algae-loaded filter bed was drained of free water and added with methanol and ozonated for 2 min to rupture cell membrane to accelerate release of the cellular contents. The methanol solution now containing the dissolved lipid product was collected by draining, while the filter bed was regenerated by further ozonation when needed. The results showed 95% collection of the algal biomass from the suspension and a 16% yield of lipid from the algae, as well as restoration of filtration velocity of the sand bed via ozonation. The results further showed increased lipid yield upon cell rupturing and transesterified products composed entirely of fatty acid methyl ester (FAME) compounds, demonstrating that the rupture and transesterification processes could proceed consecutively in the same medium, requiring no separate steps of drying, extraction, and conversion. The FAME products from algae without exposure to ozone were mainly of 16 to 18 carbons containing up to 3 double bonds, while those from algae having been ozonated were smaller, highly saturated hydrocarbons. The new technique streamlines individual steps from cultivated algal lipid to transesterified products and

  13. A review on algal biofuel production

    Institute of Scientific and Technical Information of China (English)

    WANG Ling; ZHU jing

    2016-01-01

    Culturing of microalgae has be established as an alternative feedstock for biofuel production due to their fast growth rate and ability to accumulate high quantity of lipid and carbohydrate respectively. However, using this bioresource is still limited duo to low productivity and higher cultivation cost. Genetic and metabolic engineering,photobioreactors play significant role in algal biomass production. Hence, this review is focused on these, aiming at providing useful informations.

  14. Algal Cell Response to Pulsed Waved Stimulation and Its Application to Increase Algal Lipid Production

    Science.gov (United States)

    Savchenko, Oleksandra; Xing, Jida; Yang, Xiaoyan; Gu, Quanrong; Shaheen, Mohamed; Huang, Min; Yu, Xiaojian; Burrell, Robert; Patra, Prabir; Chen, Jie

    2017-01-01

    Generating renewable energy while sequestering CO2 using algae has recently attracted significant research attention, mostly directing towards biological methods such as systems biology, genetic engineering and bio-refining for optimizing algae strains. Other approaches focus on chemical screening to adjust culture conditions or culture media. We report for the first time the physiological changes of algal cells in response to a novel form of mechanical stimulation, or a pulsed wave at the frequency of 1.5 MHz and the duty cycle of 20%. We studied how the pulsed wave can further increase algal lipid production on top of existing biological and chemical methods. Two commonly used algal strains, fresh-water Chlorella vulgaris and seawater Tetraselmis chuii, were selected. We have performed the tests in shake flasks and 1 L spinner-flask bioreactors. Conventional Gravimetric measurements show that up to 20% increase for algal lipid could be achieved after 8 days of stimulation. The total electricity cost needed for the stimulations in a one-liter bioreactor is only one-tenth of a US penny. Gas liquid chromatography shows that the fatty acid composition remains unchanged after pulsed-wave stimulation. Scanning electron microscope results also suggest that pulsed wave stimulation induces shear stress and thus increases algal lipid production. PMID:28186124

  15. Algal Cell Response to Pulsed Waved Stimulation and Its Application to Increase Algal Lipid Production

    Science.gov (United States)

    Savchenko, Oleksandra; Xing, Jida; Yang, Xiaoyan; Gu, Quanrong; Shaheen, Mohamed; Huang, Min; Yu, Xiaojian; Burrell, Robert; Patra, Prabir; Chen, Jie

    2017-02-01

    Generating renewable energy while sequestering CO2 using algae has recently attracted significant research attention, mostly directing towards biological methods such as systems biology, genetic engineering and bio-refining for optimizing algae strains. Other approaches focus on chemical screening to adjust culture conditions or culture media. We report for the first time the physiological changes of algal cells in response to a novel form of mechanical stimulation, or a pulsed wave at the frequency of 1.5 MHz and the duty cycle of 20%. We studied how the pulsed wave can further increase algal lipid production on top of existing biological and chemical methods. Two commonly used algal strains, fresh-water Chlorella vulgaris and seawater Tetraselmis chuii, were selected. We have performed the tests in shake flasks and 1 L spinner-flask bioreactors. Conventional Gravimetric measurements show that up to 20% increase for algal lipid could be achieved after 8 days of stimulation. The total electricity cost needed for the stimulations in a one-liter bioreactor is only one-tenth of a US penny. Gas liquid chromatography shows that the fatty acid composition remains unchanged after pulsed-wave stimulation. Scanning electron microscope results also suggest that pulsed wave stimulation induces shear stress and thus increases algal lipid production.

  16. 滇池流域入湖河流丰水期着生藻类群落特征及其与水环境因子的关系%Characteristics of periphytic algal community and its relationship with aquatic environmental factors in streams of Lake Dianchi watershed in wet season

    Institute of Scientific and Technical Information of China (English)

    文航; 蔡佳亮; 苏玉; 王东伟; 黄艺

    2011-01-01

    Periphytic algae are important biological indicators in the water environment. Their species composition, density, and diversity are widely used for monitoring and evaluating the impact of human activities on the aquatic ecosystem. The survey data of periphytic algae during July and August of 2009 and monthly physical-chemical parameters of the 29 streams of Lake Dianehi(LD)watershed from September 2008 to August 2009 were analyzed. Hierarchical cluster analysis, factor analysis, and canonical correspondence analysis were used to relate the characteristics of periphytic algal community to aquatic environmental factors and their spatial pattern in order to provide controlling objectives for integrated LD watershed management. A total of 5 phylum, 18 families,and 24 genera of periphytic algae were identified, including 10 genera in 7 fnmilies of Bacillariophyta, 7 genera in 6 families of Chlorophyta, 4 genera in 2 families of Cyanophyta, 2 genera in 2 families of Chrysophyta, and 1 genus in 1 family of Euglenophyta. Among them, Navicula(Baeillariophyta) was the dominant genus. The spatial patterns of periphytic algal density, and Navicula density and abundance in the wet season were greatest in streams flowing to north LD, followed by those flowing to south LD,and then by those to east LD. TN, NH3-N, and TP were the key aquatic environmental factors affecting the characteristics of periphytic algal community in the wet season. The spatial pattern of integrated pollution of TN, NH3 -N, and TP was also the greatest in streams flowing to north LD, followed by those flowing to south LD, and then by those to east LD.%着生藻类是重要的水环境指示生物,其物种组成、生物密度以及多样性指数等群落特征被广泛用于监测和评价人为活动干扰对水生生态系统所造成的影响.本文根据滇池流域29条入湖河流2009年7-8月着生藻类调查数据,以及2008年9月至2009年8月逐月水环境指标监测数据,通过运用等

  17. Study of polyacrylamide grafted starch based algal flocculation towards applications in algal biomass harvesting.

    Science.gov (United States)

    Banerjee, Chiranjib; Gupta, Pratibha; Mishra, Sumit; Sen, Gautam; Shukla, Pratyoosh; Bandopadhyay, Rajib

    2012-11-01

    Microalgae may be the source of high amount of lipid and protein. It has the property for carbon dioxide sequestration, recycling and also can remove pollutants from wastewater. Using traditional methods, collection of algal biomass is either cost effective, time consuming or may be toxic due to use of chemical salts. The aim of this study is to harvest freshwater microalgae (Chlorella sp. CB4) biomass by using polymer. Polyacrylamide grafted starch (St-g-PAM) has been synthesized by microwave assisted method involving a synergism of microwave radiation and ceric ammonium nitrate (CAN) to initiate the grafting reaction. The synthesis was optimized in terms of CAN and monomer (acrylamide) concentration. The algal flocculation efficacy of all the grades of this graft copolymer was studied through standard 'Jar test' procedure. Effects of percentage grafting, pH and zeta potential on percentage recovery of algal biomass were thoroughly investigated.

  18. Norwegian remote sensing spectrometry for mapping and monitoring of algal blooms and pollution - NORSMAP-89

    Energy Technology Data Exchange (ETDEWEB)

    Pettersson, L.H.; Johannessen, O.M.; Frette, O. (Nansen Remote Sensing Center, Bergen (Norway))

    1990-01-09

    During the late spring of 1988 an extensive bloom of the toxic algae Chrysocromulina polylepis occurred in the Skagerrak region influencing most life in the upper 30 meter of the ocean. The algal front was advected northward with the Norwegian Coastal Current along the coast of southern Norway, where it became a severe threat to the Norwegian seafarming industry. An ad-hoc expert team was established to monitor and forecast the movement of the algae front. Remote sensing of sea surface temperature from the operational US NOAA satellites monitored the movement of the algal front, consistent with a warm ocean front. The lack of any optical remote sensing instrumentation was recognized as a major de-efficiency during this algal bloom. To prepare for similar events in the future Nansen Remote Sensing Center initiated a three week pilot study in the Oslofjord and Skagerrak region, during May 1989. The Canadian Compact Airborne Spectrographic Imager (CASI) was installed in the surveillance aircraft. Extensive in situ campaigns was also carried out by the Norwegian Institute for Water Research and Institute of Marine Research. A ship-borne non-imaging spectrometer was operated from the vessels participating in the field campaign. As a contribution from a joint campaign (EISAC '89) between the Joint Research Centre (JRC) of the European Community and the European Space Agency (ESA) both the Canadian Fluorescence Line Imager (FLI) and the US 64-channel GER scanner was operated simultaneously at the NORSMAP 89 test site. Regions of different biological and physical conditions were covered during the pilot study and preliminary analysis are obtained from oil slicks, suspended matter from river, as well as minor algal bloom. The joint analysis of the data collected during the NORSMAP 89 campaign and conclussions will be presented, as well as suggestions for future utilization of airborne spectroscopy systems for operational monitoring of algal bloom and water pollution.

  19. Mechanism and challenges in commercialisation of algal biofuels.

    Science.gov (United States)

    Singh, Anoop; Nigam, Poonam Singh; Murphy, Jerry D

    2011-01-01

    Biofuels made from algal biomass are being considered as the most suitable alternative energy in current global and economical scenario. Microalgae are known to produce and accumulate lipids within their cell mass which is similar to those found in many vegetable oils. The efficient lipid producer algae cell mass has been reported to contain more than 30% of their cell weight as lipids. According to US DOE microalgae have the potential to produce 100 times more oil per acre land than any terrestrial plants. This article reviews up to date literature on the composition of algae, mechanism of oil droplets, triacylglycerol (TAG) production in algal biomass, research and development made in the cultivation of algal biomass, harvesting strategies, and recovery of lipids from algal mass. The economical challenges in the production of biofuels from algal biomass have been discussed in view of the future prospects in the commercialisation of algal fuels.

  20. Optimizing algal cultivation & productivity : an innovative, multidiscipline, and multiscale approach.

    Energy Technology Data Exchange (ETDEWEB)

    Murton, Jaclyn K.; Hanson, David T. (University of New Mexico, Albuquerque, NM); Turner, Tom (University of New Mexico, Albuquerque, NM); Powell, Amy Jo; James, Scott Carlton (Sandia National Laboratories, Livermore, CA); Timlin, Jerilyn Ann; Scholle, Steven (University of New Mexico, Albuquerque, NM); August, Andrew (Sandia National Laboratories, Livermore, CA); Dwyer, Brian P.; Ruffing, Anne; Jones, Howland D. T.; Ricken, James Bryce; Reichardt, Thomas A. (Sandia National Laboratories, Livermore, CA)

    2010-04-01

    Progress in algal biofuels has been limited by significant knowledge gaps in algal biology, particularly as they relate to scale-up. To address this we are investigating how culture composition dynamics (light as well as biotic and abiotic stressors) describe key biochemical indicators of algal health: growth rate, photosynthetic electron transport, and lipid production. Our approach combines traditional algal physiology with genomics, bioanalytical spectroscopy, chemical imaging, remote sensing, and computational modeling to provide an improved fundamental understanding of algal cell biology across multiple cultures scales. This work spans investigations from the single-cell level to ensemble measurements of algal cell cultures at the laboratory benchtop to large greenhouse scale (175 gal). We will discuss the advantages of this novel, multidisciplinary strategy and emphasize the importance of developing an integrated toolkit to provide sensitive, selective methods for detecting early fluctuations in algal health, productivity, and population diversity. Progress in several areas will be summarized including identification of spectroscopic signatures for algal culture composition, stress level, and lipid production enabled by non-invasive spectroscopic monitoring of the photosynthetic and photoprotective pigments at the single-cell and bulk-culture scales. Early experiments compare and contrast the well-studied green algae chlamydomonas with two potential production strains of microalgae, nannochloropsis and dunnaliella, under optimal and stressed conditions. This integrated approach has the potential for broad impact on algal biofuels and bioenergy and several of these opportunities will be discussed.

  1. Algal biodiesel economy and competition among bio-fuels.

    Science.gov (United States)

    Lee, D H

    2011-01-01

    This investigation examines the possible results of policy support in developed and developing economies for developing algal biodiesel through to 2040. This investigation adopts the Taiwan General Equilibrium Model-Energy for Bio-fuels (TAIGEM-EB) to predict competition among the development of algal biodiesel, bioethanol and conventional crop-based biodiesel. Analytical results show that algal biodiesel will not be the major energy source in 2040 without strong support in developed economies. In contrast, bioethanol enjoys a development advantage relative to both forms of biodiesel. Finally, algal biodiesel will almost completely replace conventional biodiesel. CO(2) reduction benefits the development of the bio-fuels industry.

  2. Algal Attributes: An Autecological Classification of Algal Taxa Collected by the National Water-Quality Assessment Program

    Science.gov (United States)

    Porter, Stephen D.

    2008-01-01

    Algae are excellent indicators of water-quality conditions, notably nutrient and organic enrichment, and also are indicators of major ion, dissolved oxygen, and pH concentrations and stream microhabitat conditions. The autecology, or physiological optima and tolerance, of algal species for various water-quality contaminants and conditions is relatively well understood for certain groups of freshwater algae, notably diatoms. However, applications of autecological information for water-quality assessments have been limited because of challenges associated with compiling autecological literature from disparate sources, tracking name changes for a large number of algal species, and creating an autecological data base from which algal-indicator metrics can be calculated. A comprehensive summary of algal autecological attributes for North American streams and rivers does not exist. This report describes a large, digital data file containing 28,182 records for 5,939 algal taxa, generally species or variety, collected by the U.S. Geological Survey?s National Water-Quality Assessment (NAWQA) Program. The data file includes 37 algal attributes classified by over 100 algal-indicator codes or metrics that can be calculated easily with readily available software. Algal attributes include qualitative classifications based on European and North American autecological literature, and semi-quantitative, weighted-average regression approaches for estimating optima using regional and national NAWQA data. Applications of algal metrics in water-quality assessments are discussed and national quartile distributions of metric scores are shown for selected indicator metrics.

  3. Growing Pains (For Parents)

    Science.gov (United States)

    ... Month-Old Feeding Your 1- to 2-Year-Old Growing Pains KidsHealth > For Parents > Growing Pains Print A ... olds and, later, in 8- to 12-year-olds. Signs and Symptoms Growing pains always concentrate in the muscles , rather than ...

  4. An Ambition to Grow

    OpenAIRE

    Ron Kemp; R Hakkert

    2006-01-01

    This report tries to gain insight in the willingness or ambition to grow of a small business owner. The main question of this report is therefore: Which factors influence the ambition to grow a business? To examine the ambition to grow an economic and a psychological perspective is given in this study.

  5. Biophotolysis, hydrogen, production and algal culture technology

    Energy Technology Data Exchange (ETDEWEB)

    Skulberg, O.M. [Norwegian Inst. for Water Research, Oslo (Norway)

    1995-12-31

    In this essay the importance and place of biophotolysis in the hydrogen energy system is described. The biophotolysis of water is achieved by two biochemical processes carried out by the activity of chlorophyll containing reaction centres coupled to hydrogenase and nitrogenase. Micro algae belonging to the classes Chlorophyceae and Cyanophyceae can produce molecular hydrogen by the decomposition of water using solar energy. Among Anoxyphotobactelia organisms of the families Chrorna iaceae and Chlorobiaceae are also used for the bioengineering development of biophotolysis. A review is presented of the organisms and the processes involved in the context of their applications for algal culture technology. 2 tabs., 52 refs.

  6. Linking algal growth inhibition to chemical activity

    DEFF Research Database (Denmark)

    Schmidt, Stine N.; Mayer, Philipp

    to chemical activity, as opposed to e.g. the total concentration. Baseline toxicity (narcosis) for neutral hydrophobic organic compounds has been shown to initiate in the narrow chemical activity range of 0.01 to 0.1. This presentation focuses on linking algal growth inhibition to chemical activity....... High-quality toxicity data are carefully selected from peer-reviewed scientific literature and QSAR databases. This presentation shows how the chemical activity concept can be used to compare and combine toxicity data across compounds and species in order to characterize toxicity – and further how...

  7. Accelerating Commercialization of Algal Biofuels Through Partnerships (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2011-10-01

    This brochure describes National Renewable Energy Laboratory's (NREL's) algal biofuels research capabilities and partnership opportunities. NREL is accelerating algal biofuels commercialization through: (1) Advances in applied biology; (2) Algal strain development; (3) Development of fuel conversion pathways; (4) Techno-economic analysis; and (5) Development of high-throughput lipid analysis methodologies. NREL scientists and engineers are addressing challenges across the algal biofuels value chain, including algal biology, cultivation, harvesting and extraction, and fuel conversion. Through partnerships, NREL can share knowledge and capabilities in the following areas: (1) Algal Biology - A fundamental understanding of algal biology is key to developing cost-effective algal biofuels processes. NREL scientists are experts in the isolation and characterization of microalgal species. They are identifying genes and pathways involved in biofuel production. In addition, they have developed a high-throughput, non-destructive technique for assessing lipid production in microalgae. (2) Cultivation - NREL researchers study algal growth capabilities and perform compositional analysis of algal biomass. Laboratory-scale photobioreactors and 1-m2 open raceway ponds in an on-site greenhouse allow for year-round cultivation of algae under a variety of conditions. A bioenergy-focused algal strain collection is being established at NREL, and our laboratory houses a cryopreservation system for long-term maintenance of algal cultures and preservation of intellectual property. (3) Harvesting and Extraction - NREL is investigating cost-effective harvesting and extraction methods suitable for a variety of species and conditions. Areas of expertise include cell wall analysis and deconstruction and identification and utilization of co-products. (4) Fuel Conversion - NREL's excellent capabilities and facilities for biochemical and thermochemical conversion of biomass to

  8. Transformation of Swine Manure and Algal Consortia to Value-added Products

    Science.gov (United States)

    Sharara, Mahmoud A.

    The swine production sector is projected to grow globally. In the past, this growth manifested itself in increased herd sizes and geographically concentrated production. Although economically sound, these trends had negative consequences on surrounding ecosystems. Over-application of manure resulted in water quality degradation, while long-term storage of manure slurries was found to promote release of potent GHG emissions. There is a need for innovative approaches for swine manure management that are compatible with current scales of production, and increasingly strict environmental regulations. This study aims to investigate the potential for incorporating gasification as part of a novel swine manure management system which utilizes liquid-solid separation and periphytic algal consortia as a phycoremediation vector for the liquid slurry. The gasification of swine manure solids, and algal biomass solids generate both a gaseous fuel product (producer gas) in addition to a biochar co-product. First, the decomposition kinetics for both feedstock, i.e., swine manure solids, and algal solids, were quantified using thermogravimetry at different heating rates (1 ~ 40°C min-1) under different atmospheres (nitrogen, and air). Pyrolysis kinetics were determined for manure solids from two farms with different manure management systems. Similarly, the pyrolysis kinetics were determined for phycoremediation algae grown on swine manure slurries. Modeling algal solids pyrolysis as first-order independent parallel reactions was sufficient to describe sample devolatilization. Combustion of swine manure solids blended with algal solids, at different ratios, showed no synergistic effects. Gasification of phycoremediation algal biomass was studied using a bench-scale auger gasification system at temperatures between 760 and 960°C. The temperature profile suggested a stratification of reaction zones common to fixed-bed reactors. The producer gas heating value ranged between 2.2 MJ m

  9. Real time observations of coastal algal blooms by an early warning system

    Science.gov (United States)

    Lee, J. H. W.; Hodgkiss, I. J.; Wong, K. T. M.; Lam, I. H. Y.

    2005-10-01

    In eutrophic sub-tropical coastal waters around Hong Kong, phytoplankton or unicellular microalgae can grow rapidly to very high concentrations under favourable environmental conditions. These harmful algal blooms (HABs) have led to massive fish kills, hypoxia, and beach closures. However, to date the causality and mechanism of coastal algal blooms are still poorly understood. A remotely controlled autonomous real time field monitoring system has been developed to continuously track the changes in chlorophyll fluorescence, dissolved oxygen and other hydro-meteorological variables at two representative mariculture zones. The system can give an alarm when a bloom is detected, so that timely manual water quality sampling can be carried out to supplement the telemetric data. During 2000-2003, the system has successfully tracked 19 algal blooms. In the shallow weakly flushed coastal water (depth 7-10 m, tidal current 5-19 cm s -1), the bloom is short-lived, typically lasting a few days to over a week, with chlorophyll and DO concentrations in the range of 20-40 mg m -3 and 2-15 g m -3, respectively. It is found that: (1) the chlorophyll concentration is strongly correlated with its past values in the previous week, suggesting an auto-regressive type of algal dynamics; (2) the dissolved oxygen can reach highly super-saturated levels (12 g m -3) during a diatom bloom, and decreases to below 4 g m -3 at the tail of the growth phase; (3) in contrast, a dinoflagellate bloom is characterized by a much more pronounced vertical structure. Diel vertical migration and aggregation to dense layers are clearly observed. Significant dissolved oxygen consumption is associated with the migration, resulting in DO drops by as much as 6 g m -3 during the bloom; (4) the predominance of diatoms and dinoflagellates at the two sites can be explained in terms of the different hydrographic and nutrient conditions (the N:P ratio). Net algal growth rate, sinking and swimming velocities are

  10. Luminescent Solar Concentrators in the Algal Industry

    Science.gov (United States)

    Hellier, Katie; Corrado, Carley; Carter, Sue; Detweiler, Angela; Bebout, Leslie

    2013-03-01

    Today's industry for renewable energy sources and highly efficient energy management systems is rapidly increasing. Development of increased efficiency Luminescent Solar Concentrators (LSCs) has brought about new applications for commercial interests, including greenhouses for agricultural crops. This project is taking first steps to explore the potential of LSCs to enhance production and reduce costs for algae and cyanobacteria used in biofuels and nutraceuticals. This pilot phase uses LSC filtered light for algal growth trials in greenhouses and laboratory experiments, creating specific wavelength combinations to determine effects of discrete solar light regimes on algal growth and the reduction of heating and water loss in the system. Enhancing the optimal spectra for specific algae will not only increase production, but has the potential to lessen contamination of large scale production due to competition from other algae and bacteria. Providing LSC filtered light will reduce evaporation and heating in regions with limited water supply, while the increased energy output from photovoltaic cells will reduce costs of heating and mixing cultures, thus creating a more efficient and cost effective production system.

  11. Potential of carbon nanotubes in algal biotechnology.

    Science.gov (United States)

    Lambreva, Maya Dimova; Lavecchia, Teresa; Tyystjärvi, Esa; Antal, Taras Kornelievich; Orlanducci, Silvia; Margonelli, Andrea; Rea, Giuseppina

    2015-09-01

    A critical mass of knowledge is emerging on the interactions between plant cells and engineered nanomaterials, revealing the potential of plant nanobiotechnology to promote and support novel solutions for the development of a competitive bioeconomy. This knowledge can foster the adoption of new methodological strategies to empower the large-scale production of biomass from commercially important microalgae. The present review focuses on the potential of carbon nanotubes (CNTs) to enhance photosynthetic performance of microalgae by (i) widening the spectral region available for the energy conversion reactions and (ii) increasing the tolerance of microalgae towards unfavourable conditions occurring in mass production. To this end, current understanding on the mechanisms of uptake and localization of CNTs in plant cells is discussed. The available ecotoxicological data were used in an attempt to assess the feasibility of CNT-based applications in algal biotechnology, by critically correlating the experimental conditions with the observed adverse effects. Furthermore, main structural and physicochemical properties of single- and multi-walled CNTs and common approaches for the functionalization and characterization of CNTs in biological environment are presented. Here, we explore the potential that nanotechnology can offer to enhance functions of algae, paving the way for a more efficient use of photosynthetic algal systems in the sustainable production of energy, biomass and high-value compounds.

  12. Algal Lectins as Potential HIV Microbicide Candidates

    Directory of Open Access Journals (Sweden)

    Dominique Schols

    2012-07-01

    Full Text Available The development and use of topical microbicides potentially offers an additional strategy to reduce the spread of the Human Immunodeficiency Virus (HIV. Carbohydrate-binding agents (CBAs that show specificity for high mannose carbohydrates on the surface of the heavily glycosylated envelope of HIV are endowed with potent anti-HIV activity. In fact, a number of algal lectins such as cyanovirin-N, microvirin, microcystis viridis lectin, scytovirin, Oscillatoria agardhii agglutinin and griffithsin are considered as potential microbicide candidates to prevent the sexual transmission of HIV through topical applications. They not only inhibit infection of cells by cell-free virus but they can also efficiently prevent virus transmission from virus-infected cells to uninfected CD4+ target T-lymphocytes and DC-SIGN-directed capture of HIV-1 and transmission to CD4+ T lymphocytes. This review focuses on the structural properties and carbohydrate specificity of these algal lectins, their antiviral activity against HIV and several other enveloped viruses, their safety profile and viral resistance patterns.

  13. Pyrolysis kinetics of algal consortia grown using swine manure wastewater.

    Science.gov (United States)

    Sharara, Mahmoud A; Holeman, Nathan; Sadaka, Sammy S; Costello, Thomas A

    2014-10-01

    In this study, pyrolysis kinetics of periphytic microalgae consortia grown using swine manure slurry in two seasonal climatic patterns in northwest Arkansas were investigated. Four heating rates (5, 10, 20 and 40 °C min(-1)) were used to determine the pyrolysis kinetics. Differences in proximate, ultimate, and heating value analyses reflected variability in growing substrate conditions, i.e., flocculant use, manure slurry dilution, and differences in diurnal solar radiation and air temperature regimes. Peak decomposition temperature in algal harvests varied with changing the heating rate. Analyzing pyrolysis kinetics using differential and integral isoconversional methods (Friedman, Flynn-Wall-Ozawa, and Kissinger-Akahira-Sunose) showed strong dependency of apparent activation energy on the degree of conversion suggesting parallel reaction scheme. Consequently, the weight loss data in each thermogravimetric test was modeled using independent parallel reactions (IPR). The quality of fit (QOF) for the model ranged between 2.09% and 3.31% indicating a good agreement with the experimental data.

  14. Algal Lipid Extraction and Upgrading to Hydrocarbons Technology Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Davis, R.; Biddy, M.; Jones, S.

    2013-03-01

    This technology pathway case investigates the cultivation of algal biomass followed by further lipid extraction and upgrading to hydrocarbon biofuels. Technical barriers and key research needs have been assessed in order for the algal lipid extraction and upgrading pathway to be competitive with petroleum-derived gasoline-, diesel-, and jet-range hydrocarbon blendstocks.

  15. Experimental Protocol for Biodiesel Production with Isolation of Alkenones as Coproducts from Commercial Isochrysis Algal Biomass.

    Science.gov (United States)

    O'Neil, Gregory W; Williams, John R; Wilson-Peltier, Julia; Knothe, Gerhard; Reddy, Christopher M

    2016-06-24

    The need to replace petroleum fuels with alternatives from renewable and more environmentally sustainable sources is of growing importance. Biomass-derived biofuels have gained considerable attention in this regard, however first generation biofuels from edible crops like corn ethanol or soybean biodiesel have generally fallen out of favor. There is thus great interest in the development of methods for the production of liquid fuels from domestic and superior non-edible sources. Here we describe a detailed procedure for the production of a purified biodiesel from the marine microalgae Isochrysis. Additionally, a unique suite of lipids known as polyunsaturated long-chain alkenones are isolated in parallel as potentially valuable coproducts to offset the cost of biodiesel production. Multi-kilogram quantities of Isochrysis are purchased from two commercial sources, one as a wet paste (80% water) that is first dried prior to processing, and the other a dry milled powder (95% dry). Lipids are extracted with hexanes in a Soxhlet apparatus to produce an algal oil ("hexane algal oil") containing both traditional fats (i.e., triglycerides, 46-60% w/w) and alkenones (16-25% w/w). Saponification of the triglycerides in the algal oil allows for separation of the resulting free fatty acids (FFAs) from alkenone-containing neutral lipids. FFAs are then converted to biodiesel (i.e., fatty acid methyl esters, FAMEs) by acid-catalyzed esterification while alkenones are isolated and purified from the neutral lipids by crystallization. We demonstrate that biodiesel from both commercial Isochrysis biomasses have similar but not identical FAME profiles, characterized by elevated polyunsaturated fatty acid contents (approximately 40% w/w). Yields of biodiesel were consistently higher when starting from the Isochrysis wet paste (12% w/w vs. 7% w/w), which can be traced to lower amounts of hexane algal oil obtained from the powdered Isochrysis product.

  16. Experimental Protocol for Biodiesel Production with Isolation of Alkenones as Coproducts from Commercial Isochrysis Algal Biomass

    Science.gov (United States)

    O'Neil, Gregory W.; Williams, John R.; Wilson-Peltier, Julia; Knothe, Gerhard; Reddy, Christopher M.

    2016-01-01

    The need to replace petroleum fuels with alternatives from renewable and more environmentally sustainable sources is of growing importance. Biomass-derived biofuels have gained considerable attention in this regard, however first generation biofuels from edible crops like corn ethanol or soybean biodiesel have generally fallen out of favor. There is thus great interest in the development of methods for the production of liquid fuels from domestic and superior non-edible sources. Here we describe a detailed procedure for the production of a purified biodiesel from the marine microalgae Isochrysis. Additionally, a unique suite of lipids known as polyunsaturated long-chain alkenones are isolated in parallel as potentially valuable coproducts to offset the cost of biodiesel production. Multi-kilogram quantities of Isochrysis are purchased from two commercial sources, one as a wet paste (80% water) that is first dried prior to processing, and the other a dry milled powder (95% dry). Lipids are extracted with hexanes in a Soxhlet apparatus to produce an algal oil ("hexane algal oil") containing both traditional fats (i.e., triglycerides, 46-60% w/w) and alkenones (16-25% w/w). Saponification of the triglycerides in the algal oil allows for separation of the resulting free fatty acids (FFAs) from alkenone-containing neutral lipids. FFAs are then converted to biodiesel (i.e., fatty acid methyl esters, FAMEs) by acid-catalyzed esterification while alkenones are isolated and purified from the neutral lipids by crystallization. We demonstrate that biodiesel from both commercial Isochrysis biomasses have similar but not identical FAME profiles, characterized by elevated polyunsaturated fatty acid contents (approximately 40% w/w). Yields of biodiesel were consistently higher when starting from the Isochrysis wet paste (12% w/w vs. 7% w/w), which can be traced to lower amounts of hexane algal oil obtained from the powdered Isochrysis product. PMID:27404113

  17. Algal biofuels: key issues, sustainability and life cycle assessment

    DEFF Research Database (Denmark)

    Singh, Anoop; Olsen, Stig Irving

    2011-01-01

    (GHG) emissions to reduce the climate change effects. Among the various renewable energy sources algal biofuels is a very promising source of biomass as algae sequester huge quantities of carbon from atmosphere and are very efficient in utilizing the nutrients from the industrial effluent and municipal...... capital investment. The harvested algal biomass and its extracts can be efficiently converted to different biofuels such as bioethanol, biodiesel, biogas and biohydrogen by implementation of various process technologies. Comprehensive life cycle assessments (LCA) of algal biofuels illustrating...... wastewater. Algae capture CO2 from atmosphere and industrial flue gases and transform it in to organic biomass that can be used for the production of biofuels. Like other biomass, algal biomass is also a carbon neutral source for the production of bioenergy. Therefore cultivation of algal biomass provides...

  18. Algal pigments record shifts in dominant primary productivity through the Holocene in an arctic lake

    Science.gov (United States)

    Florian, C.; Miller, G. H.; Fogel, M. L.

    2011-12-01

    The character and magnitude of primary productivity in arctic lakes is largely controlled by climate. Organic compounds derived from pigments and preserved in lake sediments allow reconstruction of past abundances of algae that do not leave silicious microfossils. Fossil algal pigments are abundant in lake sediment and can be accurately quantified using High Pressure Liquid Chromatography (HPLC). Several groups of algae produce unique pigments that can be used to reconstruct their past abundance. In Qivitu Highlands Lake, eastern central Baffin Island, the ratio of pigments diatoxantin and lutein exhibits coherent changes through the Holocene. Diatoxanthin is produced by diatoms and chrysophytes, whereas lutein is produced by green algae and higher plants. Because these pigments are the dominant carotenoids in the sediment, they serve as proxies for the dominant group of primary producers. During the Holocene Thermal Maximum and the past century, lutein is much more abundant than diatoxanthin. During Neoglacial cooling and into the Little Ice Age, diatoxanthin becomes the dominant carotenoid. This shift reveals that there was a change in not only the magnitude of algal production, but also the most abundant type. The adaptation of aquatic algal assemblages to changing climate suggests that gross changes in primary productivity may not be suitable to track the abundance of one type of algal microfossil (such as diatoms) without considering the other algal groups. Higher plants also produce lutein, and its abundance is additionally influenced by the presence of terrestrial organic matter as well as aquatic macrophyte plants. We hypothesize that the prevalence of lutein during warm summers is due to a longer ice-free season, allowing the development of a greater biomass of green algae and macrophyte plants as well as possible increases of terrestrial higher plant communities. This is part of a larger study where the lutein to diatoxanthin ratio is compared to organic

  19. Application of a fluorometric microplate algal toxicity assay for riverine periphytic algal species.

    Science.gov (United States)

    Nagai, Takashi; Taya, Kiyoshi; Annoh, Hirochica; Ishihara, Satoru

    2013-08-01

    Although riverine periphytic algae attached to riverbed gravel are dominant species in flowing rivers, there is limited toxicity data on them because of the difficulty in cell culture and assays. Moreover, it is well known that sensitivity to pesticides differ markedly among species, and therefore the toxicity data for multiple species need to be efficiently obtained. In this study, we investigated the use of fluorometric microplate toxicity assay for testing periphytic algal species. We selected five candidate test algal species Desmodesmus subspicatus, Achnanthidium minutissimum, Navicula pelliculosa, Nitzschia palea, and Pseudanabaena galeata. The selected species are dominant in the river, include a wide range of taxon, and represent actual species composition. Other additional species were also used to compare the sensitivity and suitability of the microplate assay. A 96-well microplate was used as a test chamber and algal growth was measured by in-vivo fluorescence. Assay conditions using microplate and fluorometric measurement were established, and sensitivities of 3,5-dichlorophenol as a reference substance were assayed. The 50 percent effect concentrations (EC50s) obtained by fluorometric microplate assay and those obtained by conventional Erlenmeyer flask assay conducted in this study were consistent. Moreover, the EC50 values of 3,5-dichlorophenol were within the reported confidence intervals in literature. These results supported the validity of our microplate assay. Species sensitivity distribution (SSD) analysis was conducted using the EC50s of five species. The SSD was found to be similar to the SSD obtained using additional tested species, suggesting that SSD using the five species largely represents algal sensitivity. Our results provide a useful and efficient method for high-tier probabilistic ecological risk assessment of pesticides.

  20. Harmful Algal Bloom Research in China

    Institute of Scientific and Technical Information of China (English)

    Su Jilan; Zhou Mingjiang

    2001-01-01

    Proliferations of harmful algae in coastal waters, i.e., harmful algal blooms (HABs), popularly known as "red tides," have attracted the concern of governments and scientists worldwide. In recent years, HABs have occurred in China with increasing frequency and scope. These outbreaks have seriously affected the economy along the coast through fish kills, heavy losses in aquaculture, threats to human health, and other effects detrimental to the marine ecosystem. Therefore, it is important to pay special attention to the ecology and oceanography studies related to the outbreak of HABs. Only through the combination of the advancement of such knowledge with the strengthening of the monitoring network can we develop a HAB warning system for the sustainable development of the coastal economy.

  1. Life cycle environmental impacts of wastewater-based algal biofuels.

    Science.gov (United States)

    Mu, Dongyan; Min, Min; Krohn, Brian; Mullins, Kimberley A; Ruan, Roger; Hill, Jason

    2014-10-07

    Recent research has proposed integrating wastewater treatment with algae cultivation as a way of producing algal biofuels at a commercial scale more sustainably. This study evaluates the environmental performance of wastewater-based algal biofuels with a well-to-wheel life cycle assessment (LCA). Production pathways examined include different nutrient sources (municipal wastewater influent to the activated sludge process, centrate from the sludge drying process, swine manure, and freshwater with synthetic fertilizers) combined with emerging biomass conversion technologies (microwave pyrolysis, combustion, wet lipid extraction, and hydrothermal liquefaction). Results show that the environmental performance of wastewater-based algal biofuels is generally better than freshwater-based algal biofuels, but depends on the characteristics of the wastewater and the conversion technologies. Of 16 pathways compared, only the centrate cultivation with wet lipid extraction pathway and the centrate cultivation with combustion pathway have lower impacts than petroleum diesel in all environmental categories examined (fossil fuel use, greenhouse gas emissions, eutrophication potential, and consumptive water use). The potential for large-scale implementation of centrate-based algal biofuel, however, is limited by availability of centrate. Thus, it is unlikely that algal biofuels can provide a large-scale and environmentally preferable alternative to petroleum transportation fuels without considerable improvement in current production technologies. Additionally, the cobenefit of wastewater-based algal biofuel production as an alternate means of treating various wastewaters should be further explored.

  2. Fungal farmers or algal escorts: lichen adaptation from the algal perspective.

    Science.gov (United States)

    Piercey-Normore, Michele D; Deduke, Christopher

    2011-09-01

    Domestication of algae by lichen-forming fungi describes the symbiotic relationship between the photosynthetic (green alga or cyanobacterium; photobiont) and fungal (mycobiont) partnership in lichen associations (Goward 1992). The algal domestication implies that the mycobiont cultivates the alga as a monoculture within its thallus, analogous to a farmer cultivating a food crop. However, the initial photobiont 'selection' by the mycobiont may be predetermined by the habitat rather than by the farmer. When the mycobiont selects a photobiont from the available photobionts within a habitat, the mycobiont may influence photobiont growth and reproduction (Ahmadjian & Jacobs 1981) only after the interaction has been initiated. The theory of ecological guilds (Rikkinen et al. 2002) proposes that habitat limits the variety of photobionts available to the fungal partner. While some studies provide evidence to support the theory of ecological guilds in cyanobacterial lichens (Rikkinen et al. 2002), other studies propose models to explain variation in symbiont combinations in green algal lichens (Ohmura et al. 2006; Piercey-Normore 2006; Yahr et al. 2006) hypothesizing the existence of such guilds. In this issue of Molecular Ecology, Peksa & Škaloud (2011) test the theory of ecological guilds and suggest a relationship between algal habitat requirements and lichen adaptation in green algal lichens of the genus Lepraria. The environmental parameters examined in this study, exposure to rainfall, altitude and substratum type, are integral to lichen biology. Lichens have a poikilohydric nature, relying on the availability of atmospheric moisture for metabolic processes. Having no known active mechanism to preserve metabolic thallus moisture in times of drought, one would expect a strong influence of the environment on symbiont adaptation to specific habitats. Adaptation to changes in substrata and its properties would be expected with the intimate contact between crustose

  3. Production of biofuel using molluscan pseudofeces derived from algal cells

    Science.gov (United States)

    Das, Keshav C.; Chinnasamy, Senthil; Shelton, James; Wilde, Susan B.; Haynie, Rebecca S.; Herrin, James A.

    2012-08-28

    Embodiments of the present disclosure provide for novel strategies to harvest algal lipids using mollusks which after feeding algae from the growth medium can convert algal lipids into their biomass or excrete lipids in their pseudofeces which makes algae harvesting energy efficient and cost effective. The bioconverter, filter-feeding mollusks and their pseudofeces can be harvested and converted to biocrude using an advanced thermochemical liquefaction technology. Methods, systems, and materials are disclosed for the harvest and isolation of algal lipids from the mollusks, molluscan feces and molluscan pseudofeces.

  4. Available Resources for Algal Biofuel Development in China

    Directory of Open Access Journals (Sweden)

    Li Chen

    2011-08-01

    Full Text Available Microalgal biofuel research in China has made noticeable progress, and algae cultivation for biofuel production is considered to be an important contribution to Greenhouse Gas (GHG mitigation and energy security. In this paper, the algal biofuel potentiality in China was reviewed from the points of view of algal biodiversity, algal culture collection, GHGs (especially CO2 mitigation, and the availability of the required sunlight, wastewater and land resources. The cultivation of microalgae utilizing power plants gas with large amounts of CO2 and wastewaters from urban households, industry and animal husbandry are suitable for large scale production in China. Land is hardly a limitation for algae cultivation.

  5. Algal growth and species composition under experimental control of herbivory, phosphorus and coral abundance in Glovers Reef, Belize.

    Science.gov (United States)

    McClanahan, T R; Cokos, B A; Sala, E

    2002-06-01

    susceptible Padina sanctae-crucis was the most abundant algae followed by Jania capillacea in this treatment in contrast to the more chemically defended Dictyota menstrualis that dominated the unmanipulated controls. We conclude that A. cervicornis was not suppressing algae as a group and its loss cannot account for the observed changes in algal abundance in most reefs except for creating space. In contrast, A. cervicornis appears to attract aggressive damselfish that may reduce herbivory by larger herbivores. Phosphorus enrichment can lead to rapid colonization of space by filamentous turf communities but not high biomass and dominance of erect frondose algae within 50 days. Moderate levels of herbivory by large-bodied herbivores promoted moderately herbivore-resistant erect brown and green algae that are commonly reported on disturbed reefs. Consequently, all the studied factors influenced algal communities but seldom as commonly predicted.

  6. The Growing Human Population.

    Science.gov (United States)

    Keyfitz, Nathan

    1989-01-01

    Discusses the issue of human population. Illustrates the projections of the growing human population in terms of developed and less developed countries. Describes the family planning programs in several countries. Lists three references for further reading. (YP)

  7. Raceways-based production of algal crude oil

    Energy Technology Data Exchange (ETDEWEB)

    Chisti, Yusuf [Massey Univ., Palmerston North (New Zealand). School of Engineering

    2013-11-01

    Raceway ponds, or 'high-rate algal ponds', of various configurations have been used to treat wastewater since the 1950s. They are also known as Oswald ponds after their inventor W. J. Oswald. Large-scale outdoor culture of microalgae and cyanobacteria in raceways is well established (Terry and Raymond 1985; Oswald 1988; Borowitzka and Borowitzka 1989; Becker 1994; Lee 1997; Molina Grima 1999; Pulz 2001; Borowitzka 2005; Spolaore et al. 2006). Raceway culture is used commercially in the United States, Thailand, China, Israel and elsewhere, mostly to produce algae for relatively high-value applications. This chapter is focused on raceways typically used in the production of algal biomass and not in the treatment of wastewater. The engineering design, operation and performance characteristics of raceways are discussed. The biomass productivity of the raceways is assessed in relation to limits imposed by algal biology. The economics of algal oil production in raceways are discussed. (orig.)

  8. Algal Biofuels R&D at NREL (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2012-09-01

    An overview of NREL's algal biofuels projects, including U.S. Department of Energy-funded work, projects with U.S. and international partners, and Laboratory Directed Research and Development projects.

  9. 2016 National Algal Biofuels Technology Review Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-06-01

    Algae-based biofuels and bioproducts offer great promise in contributing to the U.S. Department of Energy (DOE) Bioenergy Technologies Office’s (BETO’s) vision of a thriving and sustainable bioeconomy fueled by innovative technologies. The state of technology for producing algal biofuels continues to mature with ongoing investment by DOE and the private sector, but additional research, development, and demonstration (RD&D) is needed to achieve widespread deployment of affordable, scalable, and sustainable algal biofuels.

  10. The Impact of Harmful Algal Blooms on USACE Operations

    Science.gov (United States)

    2009-01-01

    recorded history around the world (Paerl 2008). Freshwater algal blooms commonly consist of many cyanobacterial algal strains, also called “blue-green...competitive edge (Huisman et al. 2005). Microcystis, a hepatotoxin created by the Microcystis algae, is most frequently cited in reports of cyanobacteria ...related poisoning in humans and livestock (Chorus and Bartram 1999) and is the dominant cyanobacteria in North America (Carmichael 2005). It is important

  11. Formation of emerging DBPs from the chlorination and chloramination of seawater algal organic matter and related model compounds

    KAUST Repository

    Nihemaiti, Maolida

    2014-05-01

    Limited studies focused on reactions occurring during disinfection and oxidation processes of seawater. The aim of this work was to investigate disinfection by-products (DBPs) formation from the chlorination and chloramination of seawater algal organic matter and related model compounds. Simulated algal blooms directly growing in Red Sea, red tide samples collected during an algal bloom event and Hymenomonas sp. monoculture were studied as algal organic matter sources. Experiments were conducted in synthetic seawater containing bromide ion. A variety of DBPs was formed from the chlorination and chloramination of algal organic matter. Brominated DBPs (bromoform, DBAA, DBAN and DBAcAm) were the dominant species. Iodinated DBPs (CIAcAm and iodinated THMs) were detected, which are known to be highly toxic compared to their chlorinated or brominated analogues. Algal organic matter was found to incorporate important precursors of nitrogenous DBPs (N-DBPs), which have been reported to be more toxic than regulated THMs and HAAs. Isotopically-labeled monochloramine (15N- NH2Cl) was used in order to investigate the nitrogen source in N-DBPs. High formation of N-DBPs was found from Hymenomonas sp. sample in exponential growth phase, which was enriched in nitrogen-containing organic compounds. High inorganic nitrogen incorporation was found from the algal samples enriched in humic-like compounds. HAcAms formation was studied from chlorination and chloramination of amino acids. Asparagine, aspartic acid and other amino acids with an aromatic structure were found to be important precursors of HAcAms and DCAN. Factors affecting HAcAms formation (Cl2/ amino acid molar ratio and pH) were evaluated. Studies on the formation kinetics of DCAcAm and DCAN from asparagine suggested a rapid formation of DCAcAm from organic nitrogen (amide group) and a slower incorporation of inorganic nitrogen coming from monochloramine to form DCAN. High amounts of DCAN and DCAcAm were detected from the

  12. Differential effects of copper on three species of scleractinian corals and their algal symbionts (Symbiodinium spp.).

    Science.gov (United States)

    Bielmyer, G K; Grosell, M; Bhagooli, R; Baker, A C; Langdon, C; Gillette, P; Capo, T R

    2010-04-15

    Land-based sources of pollution have been identified as significant stressors linked to the widespread declines of coral cover in coastal reef ecosystems over the last 30 years. Metal contaminants, although noted as a concern, have not been closely monitored in these sensitive ecosystems, nor have their potential impacts on coral-algal symbioses been characterized. In this study, three species of laboratory-reared scleractinian corals, Acropora cervicornis, Pocillopora damicornis, and Montastraea faveolata each containing different algal symbionts (Symbiodinium A3, C1 and D1a, respectively) were exposed to copper (ranging from 2 to 20microg/L) for 5 weeks. At the end of the exposure period, copper had accumulated in the endosymbiotic dinoflagellate ("zooxanthellae") and animal tissue of A. cervicornis and the animal tissue of M. faveolata; however, no copper accumulation was detected in the zooxanthellae or animal tissue of P. damicornis. The three coral species exhibited significantly different sensitivities to copper, with effects occurring in A. cervicornis and P. damicornis at copper concentrations as low as 4microg/L. Copper exposure affected zooxanthellae photosynthesis in A. cervicornis and P. damicornis, and carbonic anhydrase was significantly decreased in A. cervicornis and M. faveolata. Likewise, significant decreases in skeletal growth were observed in A. cervicornis and P. damicornis after copper exposure. Based on preliminary results, no changes in Symbiodinium communities were apparent in response to increasing copper concentration. These results indicate that the relationships between physiological/toxicological endpoints and copper accumulation between coral species differ, suggesting different mechanisms of toxicity and/or susceptibility. This may be driven, in part, by differences in the algal symbiont communities of the coral species in question.

  13. Algal biofuels: key issues, sustainability and life cycle assessment

    Energy Technology Data Exchange (ETDEWEB)

    Singh, A.; Irving Olsen, S.

    2011-05-15

    In recent years research activities are intensively focused on renewable fuels in order to fulfill the increasing energy demand and to reduce the fossil fuels consumption and external oil dependency either in order to provide local energetic resources and or as a means for reducing greenhouse gases (GHG) emissions to reduce the climate change effects. Among the various renewable energy sources algal biofuels is a very promising source of biomass as algae sequester huge quantities of carbon from atmosphere and are very efficient in utilizing the nutrients from the industrial effluent and municipal wastewater. Algae capture CO{sub 2} from atmosphere and industrial flue gases and transform it in to organic biomass that can be used for the production of biofuels. Like other biomass, algal biomass is also a carbon neutral source for the production of bioenergy. Therefore cultivation of algal biomass provides dual benefits; while being able to utilize nutrients in waste water thus reducing impacts on inland waters it produce biomass for the production of biofuels. However, reaching commercial scale production of algal biofuels is difficult. The main drawbacks include the harvesting of dry biomass and higher capital investment. The harvested algal biomass and its extracts can be efficiently converted to different biofuels such as bioethanol, biodiesel, biogas and biohydrogen by implementation of various process technologies. Comprehensive life cycle assessments (LCA) of algal biofuels illustrating environmental benefits and impacts can be a tool for policy decisions and for technology development. (Author)

  14. Harmful algal bloom smart device application: using image analysis and machine learning techniques for early classification of harmful algal blooms

    Science.gov (United States)

    The Ecological Stewardship Institute at Northern Kentucky University and the U.S. Environmental Protection Agency are collaborating to optimize a harmful algal bloom detection algorithm that estimates the presence and count of cyanobacteria in freshwater systems by image analysis...

  15. Evaluation of Harmful Algal Bloom Outreach Activities

    Directory of Open Access Journals (Sweden)

    Richard Weisman

    2007-12-01

    Full Text Available With an apparent increase of harmful algal blooms (HABs worldwide,healthcare providers, public health personnel and coastal managers are struggling toprovide scientifically-based appropriately-targeted HAB outreach and education. Since1998, the Florida Poison Information Center-Miami, with its 24 hour/365 day/year freeAquatic Toxins Hotline (1-888-232-8635 available in several languages, has received over 25,000 HAB-related calls. As part of HAB surveillance, all possible cases of HAB-relatedillness among callers are reported to the Florida Health Department. This pilot studyevaluated an automated call processing menu system that allows callers to access bilingualHAB information, and to speak directly with a trained Poison Information Specialist. Themajority (68% of callers reported satisfaction with the information, and many provided specific suggestions for improvement. This pilot study, the first known evaluation of use and satisfaction with HAB educational outreach materials, demonstrated that the automated system provided useful HAB-related information for the majority of callers, and decreased the routine informational call workload for the Poison Information Specialists, allowing them to focus on callers needing immediate assistance and their healthcare providers. These results will lead to improvement of this valuable HAB outreach, education and surveillance tool. Formal evaluation is recommended for future HAB outreach and educational materials.

  16. Adsorption of Nanoplastics on Algal Photosynthesis

    Science.gov (United States)

    Turner, James; Bhattacharya, Priyanka; Lin, Sijie; Ke, Pu Chun

    2010-03-01

    The rapid accumulation of disposed plastics in the environment, especially in the Pacific Ocean, has become a global concern in recent years. Photo, chemical and physical degradations constantly fragment these plastics into a wide array of macroscopic to microscopic particles. As a result, marine organisms such as algae may be exposed to plastic particles through ingestion, adsorption and other forms of uptake. Such interactions, currently little understood, could potentially impact on the health state of the entire food chain. Here we report on polystyrene-algae interaction and its impact on algal photosynthesis. We first investigated the adsorption of polystyrene beads (20 nm) on a cellulose film coated on a 96-well plate. We derived a supralinear increase of the adsorption with the beads concentration for both positively and negatively charged polystyrene beads, with a saturation observed for the negatively charged polystyrene beads of concentration above 1.6 mg/mL. Using a bicarbonate indicator we discovered decreased carbon dioxide depletion due to polystyrene-algae binding. Since polystyrene beads also mediated algae aggregation, nanoplastics may alternatively be harnessed for waste water treatment.

  17. Benthic algal vegetation in Isfjorden, Svalbard

    Directory of Open Access Journals (Sweden)

    Stein Fredriksen

    2015-08-01

    Full Text Available Benthic algal vegetation was investigated at 10 sites in Isfjorden, Svalbard. Five sites were visited during summer 2010 and five during summer 2012. Both the littoral and sublittoral vegetation were sampled, the littoral by hand-picking and use of a throwable rake and the sublittoral using a triangular dredge. A total of 88 different taxa were registered, comprising 17 Chlorophyta, 40 Ochrophyta, 30 Rhodophyta and the Xantophyceae Vaucheria sp. The green algae Ulvaria splendens (Ruprecht Vinogradova was recorded in Svalbard for the first time. Most of the sites consisted of hard bottom substrate, but one site, Kapp Wijk, consisted of loose-lying calcareous red algae (rhodoliths and had species not recorded elsewhere. The sublittoral at the other sites was dominated by kelp. Molecular analysis confirmed the presence of the red alga Ceramium virgatum and a dwarf form of the brown alga Fucus vesiculosus. This study provides a baseline for future studies investigating changes in the vegetation due to environmental changes.

  18. Sixty years in algal physiology and photosynthesis.

    Science.gov (United States)

    Pirson, A

    1994-06-01

    This personal perspective records research experiences in chemistry and biology at four German universities, two before and two after World War II. The research themes came from cytophysiology of green unicellular algae, in particular their photosynthesis. The function of inorganic ions in photosynthesis and dark respiration was investigated at different degrees of specific mineral stress (deficiencies), and the kinetics of recovery followed after the addition of the missing element. Two types of recovery of photosynthesis were observed: indirect restitution via growth processes and immediate normalisation. From the latter case (K(+), phosphate, Mn(++)) the effect of manganese was emphasized as its role in photosynthetic O2 evolution became established during our research. Other themes of our group, with some bearing on photosynthesis were: synchronization of cell growth by light-dark change and effects of blue (vs. red) light on the composition of green cells. Some experiences in connection with algal mass cultures are included. Discussion of several editorial projects shows how photosynthesis, as an orginally separated field of plant biochemistry and biophysics, became included into general cell physiology and even ecophysiology of green plants. The paper contains an appreciation of the authors' main mentor Kurt Noack (1888-1963) and of Ernst Georg Pringsheim (1881-1970), founder of experimental phycology.

  19. Carbon Sequestration through Sustainably Sourced Algal Fertilizer: Deep Ocean Water.

    Science.gov (United States)

    Sherman, M. T.

    2014-12-01

    Drawing down carbon from the atmosphere happens in the oceans when marine plants are growing due to the use of carbon dioxide for biological processes and by raising the pH of the water. Macro- and microscopic marine photosynthesizers are limited in their growth by the availability of light and nutrients (nitrogen, phosphorous, iron, etc.) Deep ocean water (DOW), oceanic water from bellow about 1000m, is a natural medium for marine algae, which contains all (except in rare circumstances) necessary components for algal growth and represents over 90% of the volume of the ocean. The introduction of DOW to a tropical or summer sea can increase chlorophyll from near zero to 60 mg per M3 or more. The form of the utilization infrastructure for DOW can roughly be divided into two effective types; the unconstrained release and the open pond system. Unconstrained release has the advantage of having relatively low infrastructure investment and is available to any area of the ocean. The open pond system has high infrastructure costs but enables intensive use of DOW for harvesting macro- and microalgae and sustainable mariculture. It also enables greater concomitant production of DOW's other potential products such as electricity or potable water. However, unlike an unconstrained release the open pond system can capture much of the biomaterial from the water and limits the impact to the surrounding ecosystem. The Tidal Irrigation and Electrical System (TIESystem), is an open pond that is to be constructed on a continental shelf. It harnesses the tidal flux to pump DOW into the pond on the rising tide and then uses the falling tide to pump biologically rich material out of the pond. This biomaterial represents fixed CO2 and can be used for biofuel or fertilizers. The TIESystem benefits from an economy of scale that increases at a rate that is roughly equal to the relationship of the circumference of a circle (the barrier that creates the open pond) to the area of the pond

  20. Ceramic Ultrafiltration of Marine Algal Solutions: A Comprehensive Study

    KAUST Repository

    Dramas, Laure

    2014-09-01

    Algal bloom can significantly impact reverse osmosis desalination process and reduce the drinking water production. In 2008, a major bloom event forced several UAE reverse osmosis plants to stop their production, and in this context, a better understanding of UF membrane fouling caused by algal organic matter (AOM) is needed, in order to adjust the filtration conditions during algal bloom events. Polymeric MF/UF membranes are already widely used for RO pretreatment, but ceramic UF membranes can also be an alternative for the filtration of marine algal solutions. The fouling potential of the Red Sea and the Arabian Sea, sampled at different seasons, along with four algal monocultures grown in laboratory, and one mesocosm experiment in the Red Sea was investigated. Algal solutions induce a stronger and more irreversible fouling than terrestrial humic solution, toward ceramic membrane. During algal bloom events, this fouling is enhanced and becomes even more problematic at the decline phase of the bloom, for a similar initial DOC. Three main mechanisms are involved: the formation of a cake layer at the membrane surface; the penetration of the algal organic matter (AOM) in the pore network of the membrane; the strong adhesion of AOM with the membrane surface. The last mechanism is species-specific and metal-oxide specific. In order to understand the stronger ceramic UF fouling at the decline phase, AOM quality was analyzed every two days. During growth, AOM is getting enriched in High Molecular Weight (HMW) structures (> 200 kDa), which are mainly composed by proteins and polysaccharides, and these compounds seem to be responsible for the stronger fouling at decline phase. In order to prevent the fouling of ceramic membrane, coagulation-flocculation (CF) using ferric chloride was implemented prior to filtration. It permits a high removal of HMW compounds and greatly reduces the fouling potential of the algal solution. During brief algal bloom events, CF should be

  1. An optical system for detecting and describing major algal blooms in coastal and oceanic waters around India

    Science.gov (United States)

    Gokul, Elamurugu Alias; Shanmugam, Palanisamy

    2016-06-01

    An optical system is developed with the aim to detect and monitor three major algal blooms (including harmful algal blooms "HABs") over ecologically relevant scales around India and to strengthen algal forecasting system. This system is designed to be capable of utilizing remote sensing, in situ, and radiative transfer techniques to provide species-specific data necessary for increasing capabilities of an algal forecasting system. With the ability to measure in-water optical properties by means of remote sensing and in situ observations, the optical system developed infers the desired phytoplankton signal from spectral distributions and utilize these data in a numerical classification technique to generate species-specific maps at given spatial and temporal scales. A simple radiative transfer model is adopted for this system to provide a means to optimally interpolate to regions with sparse in situ observation data and to provide a central component to generate in-water optical properties from remotely sensed data. For a given set of inherent optical properties along with surface and bottom boundary conditions, the optical system potentially provides researchers and managers coverage at different locations and depths for tracking algal blooms in the water column. Three major algal blooms focused here include Noctiluca scintillans/miliaris, Trichodesmium erythraeum, and Cochlodinium polykrikoides, which are recurring events in coastal and oceanic waters around India. Because satellite sensors provide a synoptic view of the ocean, both spatially and temporally, our initial efforts tested this optical system using several MODIS-Aqua images and ancillary data. Validation of the results with coincident in situ data obtained from either surface samples or depth samples demonstrated the robustness and potential utility of this approach, with an accuracy of 80-90% for delineating the presence of all three blooms in a heterogeneous phytoplankton community. Despite its

  2. Growing Community Roots for the Geosciences in Miami, Florida, A Program Aimed at High School and Middle School Students to Increase Awareness of Career and Educational Opportunities in the Geosciences

    Science.gov (United States)

    Whitman, D.; Hickey-Vargas, R.; Gebelein, J.; Draper, G.; Rego, R.

    2013-12-01

    Growing Community Roots for the Geosciences is a 2-year pilot recruitment project run by the Department of Earth and Environment at Florida International University (FIU) and funded by the NSF OEDG (Opportunities for Enhancing Diversity in the Geosciences) program. FIU, the State University of Florida in Miami is a federally recognized Minority Serving Institution with over 70% of the undergraduate population coming from groups underrepresented in the geoscience workforce. The goal of this project is to inform students enrolled in the local middle and high schools to career opportunities in the geosciences and to promote pathways for underrepresented groups to university geoscience degree programs. The first year's program included a 1-week workshop for middle school teachers and a 2-week summer camp aimed at high school students in the public school system. The teacher workshop was attended by 20 teachers who taught comprehensive and physical science in grades 6-8. It included lectures on geoscience careers, fundamental concepts of solid earth and atmospheric science, hands on exercises with earth materials, fossils and microscopy, interpretation of landform with Google Earth imagery, and a field trip to a local working limestone quarry. On the first day of the workshop, participants were surveyed on their general educational background in science and their familiarity and comfort with teaching basic geoscience concepts. On the final day, the teachers participated in a group discussion where we discussed how to make geoscience topics and careers more visible in the school curriculum. The 2-week summer camp was attended by 21 students entering grades 9-12. The program included hands on exercises on geoscience and GIS concepts, field trips to local barrier islands, the Everglades, a limestone quarry and a waste to energy facility, and tours of the NOAA National Hurricane Center and the FIU SEM lab. Participants were surveyed on their general educational background

  3. Cities on the GROW

    NARCIS (Netherlands)

    Nunes, Richard; Meulen, Suzanne; Mol, G.; Bailey, Alison

    2015-01-01

    Cities on the Grow is a cross-disciplinary project that has been funded by Climate-KIC, an initiative of the European Institute of Innovation and Technology. It seeks to support the sustainable growth of urban food enterprises toward the implementation of more commercially viable business practices.

  4. Growing Old in Sweden.

    Science.gov (United States)

    Berglind, Hans

    This document contains the bases of lectures delivered in Florida by a visiting Stockholm University sociology professor. The first chapter, "Growing Old in Sweden," includes information on the income, standard of living, and quality of services available to the elderly in that country. That information is presented within the changing…

  5. Growing Up with "1984."

    Science.gov (United States)

    Franza, August

    1983-01-01

    Relates changing student reaction to George Orwell's "1984" over 20 years of teaching. Finds present high school students' acceptance of Orwell's bleak world vision both a sign of student honesty and a frightening indication of the growing reality of the book. (MM)

  6. Annoyances in Growing Up

    Institute of Scientific and Technical Information of China (English)

    Peng Yuanchang; Ye Qing

    2007-01-01

    @@ Annoyances in growing up seem to be unavoidable. Many problems still face the Chinese power industry just climbing onto a new level of 600-GW installed capacity. It has to search practicable solutions for problems with the significant themes including structure optimization,efficiency improvement and environment protection.

  7. Combinatorial life cycle assessment to inform process design of industrial production of algal biodiesel.

    Science.gov (United States)

    Brentner, Laura B; Eckelman, Matthew J; Zimmerman, Julie B

    2011-08-15

    The use of algae as a feedstock for biodiesel production is a rapidly growing industry, in the United States and globally. A life cycle assessment (LCA) is presented that compares various methods, either proposed or under development, for algal biodiesel to inform the most promising pathways for sustainable full-scale production. For this analysis, the system is divided into five distinct process steps: (1) microalgae cultivation, (2) harvesting and/or dewatering, (3) lipid extraction, (4) conversion (transesterification) into biodiesel, and (5) byproduct management. A number of technology options are considered for each process step and various technology combinations are assessed for their life cycle environmental impacts. The optimal option for each process step is selected yielding a best case scenario, comprised of a flat panel enclosed photobioreactor and direct transesterification of algal cells with supercritical methanol. For a functional unit of 10 GJ biodiesel, the best case production system yields a cumulative energy demand savings of more than 65 GJ, reduces water consumption by 585 m(3) and decreases greenhouse gas emissions by 86% compared to a base case scenario typical of early industrial practices, highlighting the importance of technological innovation in algae processing and providing guidance on promising production pathways.

  8. Comprehensive Evaluation of Algal Biofuel Production: Experimental and Target Results

    Directory of Open Access Journals (Sweden)

    Colin M. Beal

    2012-06-01

    Full Text Available Worldwide, algal biofuel research and development efforts have focused on increasing the competitiveness of algal biofuels by increasing the energy and financial return on investments, reducing water intensity and resource requirements, and increasing algal productivity. In this study, analyses are presented in each of these areas—costs, resource needs, and productivity—for two cases: (1 an Experimental Case, using mostly measured data for a lab-scale system, and (2 a theorized Highly Productive Case that represents an optimized commercial-scale production system, albeit one that relies on full-price water, nutrients, and carbon dioxide. For both cases, the analysis described herein concludes that the energy and financial return on investments are less than 1, the water intensity is greater than that for conventional fuels, and the amounts of required resources at a meaningful scale of production amount to significant fractions of current consumption (e.g., nitrogen. The analysis and presentation of results highlight critical areas for advancement and innovation that must occur for sustainable and profitable algal biofuel production can occur at a scale that yields significant petroleum displacement. To this end, targets for energy consumption, production cost, water consumption, and nutrient consumption are presented that would promote sustainable algal biofuel production. Furthermore, this work demonstrates a procedure and method by which subsequent advances in technology and biotechnology can be framed to track progress.

  9. Full-scale validation of a model of algal productivity.

    Science.gov (United States)

    Béchet, Quentin; Shilton, Andy; Guieysse, Benoit

    2014-12-02

    While modeling algal productivity outdoors is crucial to assess the economic and environmental performance of full-scale cultivation, most of the models hitherto developed for this purpose have not been validated under fully relevant conditions, especially with regard to temperature variations. The objective of this study was to independently validate a model of algal biomass productivity accounting for both light and temperature and constructed using parameters experimentally derived using short-term indoor experiments. To do this, the accuracy of a model developed for Chlorella vulgaris was assessed against data collected from photobioreactors operated outdoor (New Zealand) over different seasons, years, and operating conditions (temperature-control/no temperature-control, batch, and fed-batch regimes). The model accurately predicted experimental productivities under all conditions tested, yielding an overall accuracy of ±8.4% over 148 days of cultivation. For the purpose of assessing the feasibility of full-scale algal cultivation, the use of the productivity model was therefore shown to markedly reduce uncertainty in cost of biofuel production while also eliminating uncertainties in water demand, a critical element of environmental impact assessments. Simulations at five climatic locations demonstrated that temperature-control in outdoor photobioreactors would require tremendous amounts of energy without considerable increase of algal biomass. Prior assessments neglecting the impact of temperature variations on algal productivity in photobioreactors may therefore be erroneous.

  10. Polar coralline algal CaCO3-production rates correspond to intensity and duration of the solar radiation

    Directory of Open Access Journals (Sweden)

    S. Teichert

    2013-08-01

    Full Text Available In this study we present a comparative quantification of CaCO3 production rates by rhodolith-forming coralline red algal communities situated in high polar latitudes and assess which environmental parameters control these productions rates. The present rhodoliths act as ecosystem engineers and their carbonate skeletons provide an important ecological niche to a variety of benthic organisms. The settings are distributed along the coasts of the Svalbard archipelago, being Floskjeret (78°18' N in Isfjorden, Krossfjorden (79°08' N at the eastern coast of Haakon VII Land, Mosselbukta (79°53' N at the eastern coast of Mosselhalvøya, and Nordkappbukta (80°31' N at the northern coast of Nordaustlandet. All sites feature Arctic climate and strong seasonality. The algal CaCO3 production rates were calculated from fuchsine stained annual growth increments exhibited by the rhodoliths and range from 100.9 g (CaCO3 m−2 yr−1 at Nordkappbukta to 200.3 g (CaCO3 m−2 yr−1 at Floskjeret. The rates correlate to various environmental parameters with geographical latitude being the most significant (negative correlation, R2 = 0.95, p R2 = 0.93, p R2 = 0.87, p = 0.07, and the annual mean temperature (positive correlation, R2 = 0.48, p < 0.05. This points out sufficient light incidence to be the main control of the growth of the examined coralline red algal rhodolith communities, while temperature is less important. Thus, the ongoing global change with its rising temperatures will most likely result in impaired conditions for the algal, because the concomitant increased global runoff will decrease water transparency and hence light incidence at the four offshore sites. Regarding the aforementioned role of the rhodoliths as ecosystem engineers, the impact on the associated organisms will presumably also be negative.

  11. How to Grow Old

    Institute of Scientific and Technical Information of China (English)

    Bertrand Russell

    2008-01-01

    <正>1. In spite of the title, this article will really be on how not to grow old, which, at my time of life, is a much more important subject. My first advice would be to choose your ancestors carefully. Although both my parents died young, I have done well in this respect as regards my other ancestors. My maternal grandfather, it is true, was cut off in the flower of his youth at the age of sixty-seven,

  12. Composition, buoyancy regulation and fate of ice algal aggregates in the Central Arctic Ocean.

    Directory of Open Access Journals (Sweden)

    Mar Fernández-Méndez

    Full Text Available Sea-ice diatoms are known to accumulate in large aggregates in and under sea ice and in melt ponds. There is recent evidence from the Arctic that such aggregates can contribute substantially to particle export when sinking from the ice. The role and regulation of microbial aggregation in the highly seasonal, nutrient- and light-limited Arctic sea-ice ecosystem is not well understood. To elucidate the mechanisms controlling the formation and export of algal aggregates from sea ice, we investigated samples taken in late summer 2011 and 2012, during two cruises to the Eurasian Basin of the Central Arctic Ocean. Spherical aggregates densely packed with pennate diatoms, as well as filamentous aggregates formed by Melosira arctica showed sign of different stages of degradation and physiological stoichiometries, with carbon to chlorophyll a ratios ranging from 110 to 66700, and carbon to nitrogen molar ratios of 8-35 and 9-40, respectively. Sub-ice algal aggregate densities ranged between 1 and 17 aggregates m(-2, maintaining an estimated net primary production of 0.4-40 mg C m(-2 d(-1, and accounted for 3-80% of total phototrophic biomass and up to 94% of local net primary production. A potential factor controlling the buoyancy of the aggregates was light intensity, regulating photosynthetic oxygen production and the amount of gas bubbles trapped within the mucous matrix, even at low ambient nutrient concentrations. Our data-set was used to evaluate the distribution and importance of Arctic algal aggregates as carbon source for pelagic and benthic communities.

  13. Composition, buoyancy regulation and fate of ice algal aggregates in the Central Arctic Ocean.

    Science.gov (United States)

    Fernández-Méndez, Mar; Wenzhöfer, Frank; Peeken, Ilka; Sørensen, Heidi L; Glud, Ronnie N; Boetius, Antje

    2014-01-01

    Sea-ice diatoms are known to accumulate in large aggregates in and under sea ice and in melt ponds. There is recent evidence from the Arctic that such aggregates can contribute substantially to particle export when sinking from the ice. The role and regulation of microbial aggregation in the highly seasonal, nutrient- and light-limited Arctic sea-ice ecosystem is not well understood. To elucidate the mechanisms controlling the formation and export of algal aggregates from sea ice, we investigated samples taken in late summer 2011 and 2012, during two cruises to the Eurasian Basin of the Central Arctic Ocean. Spherical aggregates densely packed with pennate diatoms, as well as filamentous aggregates formed by Melosira arctica showed sign of different stages of degradation and physiological stoichiometries, with carbon to chlorophyll a ratios ranging from 110 to 66700, and carbon to nitrogen molar ratios of 8-35 and 9-40, respectively. Sub-ice algal aggregate densities ranged between 1 and 17 aggregates m(-2), maintaining an estimated net primary production of 0.4-40 mg C m(-2) d(-1), and accounted for 3-80% of total phototrophic biomass and up to 94% of local net primary production. A potential factor controlling the buoyancy of the aggregates was light intensity, regulating photosynthetic oxygen production and the amount of gas bubbles trapped within the mucous matrix, even at low ambient nutrient concentrations. Our data-set was used to evaluate the distribution and importance of Arctic algal aggregates as carbon source for pelagic and benthic communities.

  14. The Mind Grows Circuits

    CERN Document Server

    Panigrahy, Rina

    2012-01-01

    There is a vast supply of prior art that study models for mental processes. Some studies in psychology and philosophy approach it from an inner perspective in terms of experiences and percepts. Others such as neurobiology or connectionist-machines approach it externally by viewing the mind as complex circuit of neurons where each neuron is a primitive binary circuit. In this paper, we also model the mind as a place where a circuit grows, starting as a collection of primitive components at birth and then builds up incrementally in a bottom up fashion. A new node is formed by a simple composition of prior nodes when we undergo a repeated experience that can be described by that composition. Unlike neural networks, however, these circuits take "concepts" or "percepts" as inputs and outputs. Thus the growing circuits can be likened to a growing collection of lambda expressions that are built on top of one another in an attempt to compress the sensory input as a heuristic to bound its Kolmogorov Complexity.

  15. Copper removal by algae Gelidium, agar extraction algal waste and granulated algal waste: kinetics and equilibrium.

    Science.gov (United States)

    Vilar, Vítor J P; Botelho, Cidália M S; Boaventura, Rui A R

    2008-03-01

    Biosorption of copper ions by an industrial algal waste, from agar extraction industry has been studied in a batch system. This biosorbent was compared with the algae Gelidium itself, which is the raw material for agar extraction, and the industrial waste immobilized with polyacrylonitrile (composite material). The effects of contact time, pH, ionic strength (IS) and temperature on the biosorption process have been studied. Equilibrium data follow both Langmuir and Langmuir-Freundlich models. The parameters of Langmuir equilibrium model were: q(max)=33.0mgg(-1), K(L)=0.015mgl(-1); q(max)=16.7mgg(-1), K(L)=0.028mgl(-1) and q(max)=10.3mgg(-1), K(L)=0.160mgl(-1) respectively for Gelidium, algal waste and composite material at pH=5.3, T=20 degrees C and IS=0.001M. Increasing the pH, the number of deprotonated active sites increases and so the uptake capacity of copper ions. In the case of high ionic strengths, the contribution of the electrostatic component to the overall binding decreases, and so the uptake capacity. The temperature has little influence on the uptake capacity principally for low equilibrium copper concentrations. Changes in standard enthalpy, Gibbs energy and entropy during biosorption were determined. Kinetic data at different solution pH (3, 4 and 5.3) were fitted to pseudo-first-order and pseudo-second-order models. The adsorptive behaviour of biosorbent particles was modelled using a batch reactor mass transfer kinetic model, which successfully predicts Cu(II) concentration profiles.

  16. Algal food and fuel coproduction can mitigate greenhouse gas emissions while improving land and water-use efficiency

    Science.gov (United States)

    Walsh, Michael J.; Gerber Van Doren, Léda; Sills, Deborah L.; Archibald, Ian; Beal, Colin M.; Gen Lei, Xin; Huntley, Mark E.; Johnson, Zackary; Greene, Charles H.

    2016-11-01

    The goals of ensuring energy, water, food, and climate security can often conflict. Microalgae (algae) are being pursued as a feedstock for both food and fuels—primarily due to algae’s high areal yield and ability to grow on non-arable land, thus avoiding common bioenergy-food tradeoffs. However, algal cultivation requires significant energy inputs that may limit potential emission reductions. We examine the tradeoffs associated with producing fuel and food from algae at the energy-food-water-climate nexus. We use the GCAM integrated assessment model to demonstrate that algal food production can promote reductions in land-use change emissions through the offset of conventional agriculture. However, fuel production, either via co-production of algal food and fuel or complete biomass conversion to fuel, is necessary to ensure long-term emission reductions, due to the high energy costs of cultivation. Cultivation of salt-water algae for food products may lead to substantial freshwater savings; but, nutrients for algae cultivation will need to be sourced from waste streams to ensure sustainability. By reducing the land demand of food production, while simultaneously enhancing food and energy security, algae can further enable the development of terrestrial bioenergy technologies including those utilizing carbon capture and storage. Our results demonstrate that large-scale algae research and commercialization efforts should focus on developing both food and energy products to achieve environmental goals.

  17. Using wastewater and high-rate algal ponds for nutrient removal and the production of bioenergy and biofuels.

    Science.gov (United States)

    Batten, David; Beer, Tom; Freischmidt, George; Grant, Tim; Liffman, Kurt; Paterson, David; Priestley, Tony; Rye, Lucas; Threlfall, Greg

    2013-01-01

    This paper projects a positive outcome for large-scale algal biofuel and energy production when wastewater treatment is the primary goal. Such a view arises partly from a recent change in emphasis in wastewater treatment technology, from simply oxidising the organic matter in the waste (i.e. removing the biological oxygen demand) to removing the nutrients - specifically nitrogen and phosphorus - which are the root cause of eutrophication of inland waterways and coastal zones. A growing need for nutrient removal greatly improves the prospects for using new algal ponds in wastewater treatment, since microalgae are particularly efficient in capturing and removing such nutrients. Using a spreadsheet model, four scenarios combining algae biomass production with the making of biodiesel, biogas and other products were assessed for two of Australia's largest wastewater treatment plants. The results showed that super critical water reactors and anaerobic digesters could be attractive pathway options, the latter providing significant savings in greenhouse gas emissions. Combining anaerobic digestion with oil extraction and the internal economies derived from cheap land and recycling of water and nutrients on-site could allow algal oil to be produced for less than US$1 per litre.

  18. Algal cell disruption using microbubbles to localize ultrasonic energy.

    Science.gov (United States)

    Krehbiel, Joel D; Schideman, Lance C; King, Daniel A; Freund, Jonathan B

    2014-12-01

    Microbubbles were added to an algal solution with the goal of improving cell disruption efficiency and the net energy balance for algal biofuel production. Experimental results showed that disruption increases with increasing peak rarefaction ultrasound pressure over the range studied: 1.90 to 3.07 MPa. Additionally, ultrasound cell disruption increased by up to 58% by adding microbubbles, with peak disruption occurring in the range of 10(8)microbubbles/ml. The localization of energy in space and time provided by the bubbles improve efficiency: energy requirements for such a process were estimated to be one-fourth of the available heat of combustion of algal biomass and one-fifth of currently used cell disruption methods. This increase in energy efficiency could make microbubble enhanced ultrasound viable for bioenergy applications and is expected to integrate well with current cell harvesting methods based upon dissolved air flotation.

  19. Consortium for Algal Biofuel Commercialization (CAB-COMM) Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Mayfield, Stephen P. [Univ. of California, San Diego, CA (United States)

    2015-12-04

    The Consortium for Algal Biofuel Commercialization (CAB-Comm) was established in 2010 to conduct research to enable commercial viability of alternative liquid fuels produced from algal biomass. The main objective of CAB-Comm was to dramatically improve the viability of algae as a source of liquid fuels to meet US energy needs, by addressing several significant barriers to economic viability. To achieve this goal, CAB-Comm took a diverse set of approaches on three key aspects of the algal biofuels value chain: crop protection; nutrient utilization and recycling; and the development of genetic tools. These projects have been undertaken as collaboration between six academic institutions and two industrial partners: University of California, San Diego; Scripps Institution of Oceanography; University of Nebraska, Lincoln; Rutgers University; University of California, Davis; Johns Hopkins University; Sapphire Energy; and Life Technologies.

  20. Design of algal film photobioreactors: material surface energy effects on algal film productivity, colonization and lipid content.

    Science.gov (United States)

    Genin, Scott N; Stewart Aitchison, J; Grant Allen, D

    2014-03-01

    A parallel plate air lift reactor was used to examine the growth kinetics of mixed culture algal biofilms grown on various materials (acrylic, glass, polycarbonate, polystyrene and cellulose acetate). The growth kinetics of the algal biofilms were non-linear overall and their overall productivities ranged from 1.10-2.08g/m(2)day, with those grown on cellulose acetate having the highest productivity. Overall algal biofilm productivity was largely explained by differences in the colonization time which in turn was strongly correlated to the polar surface energy of the material, but weakly correlated to water-material contact angle. When colonization time was taken into account, the productivity for all materials except acrylic was not significantly different at approximately 2g/m(2)/day. Lipid content of the algal biofilms ranged from 6% to 8% (w/w) and was not correlated to water-material contact angle or polar surface energy. The results have potential application for selecting appropriate materials for algal film photobioreactors.

  1. Biogas production from anaerobic digestion of Spirulina maxima algal biomass

    Energy Technology Data Exchange (ETDEWEB)

    Samson, R.; LeDuy, A.

    1982-08-01

    The photosynthetic spectrum of solar energy could be exploited for the production of chemical energy of methane through the combined algal-bacterial process. In this process, the algae are mass produced from light and from carbon in the first step. The algal biomass is then used as a nutrient for feeding the anaerobic digester, in the second step, for the production of methane by anaerobic bacteria. The carbon source for the production of algal biomass could be either organic carbon from wastewaters (for eucaryotic algae), or carbon dioxide from the atmosphere or from the combustion exhaust gases (for both prokaryotic and eukaryotic algae). The technical feasibility data on the anaerobic digestion of algal biomass have been reported for many species of algae including macroscopic algae and microscopic algae. Research being conducted in the authors' laboratory consists of using the semimicroscopic blue-green alga Spirulina maxima as the sole substrate for this combined algal-bacterial process. This species of alga is very attractive for the process because of its capability of using the atmospheric carbon dioxide as carbon source and its simple harvesting methods. Furthermore, it appeared that the fermentability of S. maxima is significantly higher than other microscopic algae. This communication presents the results on the anaerobic inoculum development by the adaptation technique. This inoculum was then used for the semicontinuous anaerobic digestion of S. maxima algal biomass. The evolutions of biogas production and composition, biogas yield, total volatile fatty acids, alkalinity, ammonia nitrogen, pH, and electrode potential were followed.

  2. Cementing mechanism of algal crusts from desert area

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    34-, 17-, 4-, 1.5-year old natural algal crusts were collected from Shapotou Scientific Station of the Chinese Academy of Sciences, 40-day old field and greenhouse artificial algal crusts were in situ developed in the same sandy soil and the same place (37°27′N, 104°57′E). Their different cohesions both against wind force and pressure were measured respectively by a sandy wind-tunnel experiment and a penetrometer. On the basis of these algal crusts, the cementing mechanism was revealed from many subjects and different levels. The results showed that in the indoor artificial crusts with the weakest cohesion bunchy algal filaments were distributed in the surface of the crusts, produced few extracellular polymers (EPS), the binding capacity of the crusts just accomplished by mechanical bundle of algal filaments. For field crusts, most filaments grew toward the deeper layers of algal crusts, secreted much more EPS, and when organic matter content was more than 2.4 times of chlorophyll a, overmuch organic matter (primarily is EPS) began to gather onto the surface of the crusts and formed an organic layer in the relatively lower micro-area, and this made the crust cohesion increase 2.5 times. When the organic layer adsorbed and intercepted amounts of dusts, soil particles and sand grains scattered down from wind, it changed gradually into an inorganic layer in which inorganic matter dominated, and this made the crusts cohesion further enhanced 2-6 times. For crust-building species Microcoleus vaginatus, 88.5% of EPS were the acidic components, 78% were the acidic proteglycan of 380 kD. The uronic acid content accounted for 8% of proteglycan, and their free carboxyls were important sites of binding with metal cations from surrounding matrix.

  3. Physical Hydrography and Algal Bloom Transport in Hong Kong Waters

    Institute of Scientific and Technical Information of China (English)

    KUANG Cui-ping; LEE Joseph H.W.

    2005-01-01

    In sub-tropical coastal waters around Hong Kong, algal blooms and red tides are usually first sighted in the Mirs Bay, in the eastern waters of Hong Kong. A calibrated three-dimensional hydrodynamic model for the Pearl River Estuary (Delft3D) has been applied to the study of the physical hydrography of Hong Kong waters and its relationship with algal bloom transport patterns in the dry and wet seasons. The general 3D hydrodynamic circulation and salinity structure in the partially-mixed estuary are presented. Extensive numerical surface drogue tracking experiments are performed for algal blooms that are initiated in the Mirs Bay under different seasonal, wind and tidal conditions. The probability of bloom impact on the Victoria Harbour and nearby urban coastal waters is estimated. The computations show that: I) In the wet season (May~August), algal blooms initiated in the Mirs Bay will move in a clockwise direction out of the bay, and be transported away from Hong Kong due to SW monsoon winds which drive the SW to NE coastal current; ii) In the dry season (November~April), algal blooms initiated in the northeast Mirs Bay will move in an anti-clockwise direction and be carried away into southern waters due to the NE to SW coastal current driven by the NE monsoon winds; the bloom typically flows past the east edge of the Victoria Harbour and nearby waters. Finally, the role of hydrodynamic transport in an important episodic event - the spring 1998 massive red tide - is quantitatively examined. It is shown that the strong NE to E wind during late March to early April, coupled with the diurnal tide at the beginning of April, significantly increased the probability of bloom transport into the Port Shelter and East Lamma Channel, resulting in the massive fish kill. The results provide a basis for risk assessment of harmful algal bloom (HAB) impact on urban coastal waters around the Victoria Habour.

  4. Export of Algal Biomass from the Melting Arctic Sea Ice

    OpenAIRE

    A. Boetius; S. Albrecht; Bakker, K; Bienhold, C.; J. Felden; Fernandez-Mendez, M; Hendricks, S.; C. Katlein; C Lalande; Krumpen, T.; M. Nicolaus; Peeken, I.; Rabe, B.; Rogacheva, A.; Rybakova, E.

    2013-01-01

    In the Arctic, under-ice primary production is limited to summer months and is restricted not only by ice thickness and snow cover but also by the stratification of the water column, which constrains nutrient supply for algal growth. Research Vessel Polarstern visited the ice-covered eastern-central basins between 82° to 89°N and 30° to 130°E in summer 2012, when Arctic sea ice declined to a record minimum. During this cruise, we observed a widespread deposition of ice algal biomass of on ave...

  5. Brown algal morphogenesis: Atomic Force Microscopy as a tool to study the role of mechanical forces

    Directory of Open Access Journals (Sweden)

    Benoit eTesson

    2014-09-01

    Full Text Available Over the last few years, a growing interest has been directed toward the use of macroalgae as a source of energy, food and molecules for the cosmetic and pharmaceutical industries. Besides this, macroalgal development remains poorly understood compared to other multicellular organisms. Brown algae (Phaeophyceae form a monophyletic lineage of usually large multicellular algae which evolved independently from land plants. In their environment, they are subjected to strong mechanical forces (current, waves and tide, in response to which they modify rapidly and reversibly their morphology. Because of their specific cellular features (cell wall composition, cytoskeleton organization, deciphering how they cope with these forces might help discover new control mechanisms of cell wall softening and cellulose synthesis. Despite the current scarcity in knowledge on brown algal cell wall dynamics and protein composition, we will illustrate, in the light of methods adapted to Ectocarpus siliculosus, to what extent atomic force microscopy can contribute to advance this field of investigation.

  6. Growing Old in Exile

    DEFF Research Database (Denmark)

    Liversage, Anika; Mirdal, Gretty Mizrahi

    2017-01-01

    Some studies on immigrants and ageing focus on the question of return; others focus on how immigrants, who grow old in their countries of destination, ‘age in place’, including whether they turn to their children or to public host country provisions for care and support. However, the issues...... of return and of ageing in place may both hold significance in individual immigrants’ lives. To investigate the changing expectations of old age throughout the life course, this paper draws on longitudinal interviews with immigrant women from Turkey who live in Denmark. We focus on the function of proximity...

  7. International trade growing fast

    Energy Technology Data Exchange (ETDEWEB)

    Bamber, D.

    1992-01-01

    Facts and figures relating to the state of the world's coal industry are quoted from a recent report by Sheffield Energy and Resources Information Services (SERIS) entitled 'Coal companies worldwide: competition and performance indicators'. The report ranks performance by country and compares data for 1990 with that of 1985. This article selects some figures on rising exports from Chinese companies and lists top ten coal exporters and producers worldwide for 1985 and 1990. Whilst in some countries exports are growing faster than production, the overall profitability of the coal industry has deteriorated. 1 ref., 2 tabs.

  8. Knowledge grows when shared

    DEFF Research Database (Denmark)

    Elbæk, Mikael Karstensen

    2010-01-01

    Knowledge is one of the few commodities that don’t devalue when used. Actually knowledge grows when shared and the free online access to peer-reviewed scientific publications is a potent ingredient the process of sharing. The sharing of knowledge is facilitated by the Open Access Movement. However...... infrastructure for Open Access was launched in Ghent, Belgium. This project and initiative is facilitating the success of the Open Access Pilot in FP7 as presented earlier in this journal. In this brief article I will present some of the most interesting issues that were discussed during the first session...

  9. The effects of an algal biofilm on the turbulent boundary layer at high Reynolds number

    Science.gov (United States)

    Murphy, Elizabeth; Barros, Julio; Schultz, Michael; Flack, Karen; Steppe, Cecily; Reidenbach, Matthew

    2016-11-01

    Algal biofilms are an important fouling community on ship hulls, with severe economic consequences due to increased drag. As with other types of roughness on aquatic surfaces, biofilms increase skin friction and thus induce severe drag penalties. In fact, slime layers appear to induce greater drag than would be predicted by the roughness height alone. Our work indicates that this is likely due to two characteristics of algal biofilms: i) flexible streamers that protrude into the flow, and ii) the compliant nature of a biofilm layer. High resolution PIV was used to measure the turbulent boundary layer flow over diatomaceous biofilm grown under dynamic conditions. Local mean streamwise velocity profiles were used to estimate the local wall shear stresses and to determine the similarity between the inner and outer layers of the boundary layer and those of a smooth wall. Spatially explicit turbulent kinetic energy (TKE), Reynolds shear stress (RSS), swirling strength and quadrant analyses over the biofilm were compared to those over a smooth wall and a rigid mesh roughness. We found that the combination of canopy flow due to streamers coupled with compliant wall-flow interactions result in large wall shear stresses and higher turbulence. Funding provided by the ONR NURP program and the NSF GRIP program.

  10. Temperature shapes coral-algal symbiosis in the South China Sea

    Science.gov (United States)

    Tong, Haoya; Cai, Lin; Zhou, Guowei; Yuan, Tao; Zhang, Weipeng; Tian, Renmao; Huang, Hui; Qian, Pei-Yuan

    2017-01-01

    With the increase in sea surface temperature (SST), scleractinian corals are exposed to bleaching threats but may possess certain flexibilities in terms of their associations with symbiotic algae. Previous studies have shown a close symbiosis between coral the and Symbiodinium; however, the spatial variation of the symbiosis and the attribution underlying are not well understood. In the present study, we examined coral-algal symbiosis in Galaxea fascicularis and Montipora spp. from three biogeographic regions across ~10° of latitude in the South China Sea. Analysis of similarities (ANOSIM) indicated a highly flexible coral-algal symbiosis in both G. fascicularis and Montipora spp. and canonical correspondence analysis (CCA) showed that temperature explained 83.2% and 60.1% of the explanatory subclade variations in G. fascicularis and Montipora spp., respectively, which suggested that temperature was the main environmental factor contributing to the diversity of Symbiodinium across the three regions. The geographic specificity of the Symbiodinium phylogeny was identified, revealing possible environmental selection across the three regions. These results suggest that scleractinian corals may have the ability to regulate Symbiodinium community structures under different temperatures and thus be able to adapt to gradual climate change.

  11. Summative Mass Analysis of Algal Biomass - Integration of Analytical Procedures: Laboratory Analytical Procedure (LAP)

    Energy Technology Data Exchange (ETDEWEB)

    Laurens, L. M. L.

    2013-12-01

    This procedure guides the integration of laboratory analytical procedures to measure algal biomass constituents in an unambiguous manner and ultimately achieve mass balance closure for algal biomass samples. Many of these methods build on years of research in algal biomass analysis.

  12. Diversity and dynamics of algal Megaviridae members during a harmful brown tide caused by the pelagophyte, Aureococcus anophagefferens.

    Science.gov (United States)

    Moniruzzaman, Mohammad; Gann, Eric R; LeCleir, Gary R; Kang, Yoonja; Gobler, Christopher J; Wilhelm, Steven W

    2016-05-01

    Many giant dsDNA algal viruses share a common ancestor with Mimivirus--one of the largest viruses, in terms of genetic content. Together, these viruses form the proposed 'Megaviridae' clade of nucleocytoplasmic large DNA viruses. To gauge Megaviridae diversity, we designed degenerate primers targeting the major capsid protein genes of algae-infecting viruses within this group and probed the clade's diversity during the course of a brown tide bloom caused by the harmful pelagophyte,Aureococcus anophagefferens We amplified target sequences in water samples from two distinct locations (Weesuck Creek and Quantuck Bay, NY) covering 12 weeks concurrent with the proliferation and demise of a bloom. In total, 475 amplicons clustered into 145 operational taxonomic units (OTUs) at 97% identity. One OTU contained 19 sequences with ≥97% identity to AaV, a member of the Megaviridae clade that infects A. anophagefferens, suggesting AaV was present during the bloom. Unifrac analysis showed clear temporal patterns in algal Megaviridae dynamics, with a shift in the virus community structure that corresponded to the Aureococcus bloom decline in both locations. Our data provide insights regarding the environmental relevance of algal Megaviridae members and raise important questions regarding their phylodynamics across different environmental gradients.

  13. Growing a market economy

    Energy Technology Data Exchange (ETDEWEB)

    Basu, N.; Pryor, R.J.

    1997-09-01

    This report presents a microsimulation model of a transition economy. Transition is defined as the process of moving from a state-enterprise economy to a market economy. The emphasis is on growing a market economy starting from basic microprinciples. The model described in this report extends and modifies the capabilities of Aspen, a new agent-based model that is being developed at Sandia National Laboratories on a massively parallel Paragon computer. Aspen is significantly different from traditional models of the economy. Aspen`s emphasis on disequilibrium growth paths, its analysis based on evolution and emergent behavior rather than on a mechanistic view of society, and its use of learning algorithms to simulate the behavior of some agents rather than an assumption of perfect rationality make this model well-suited for analyzing economic variables of interest from transition economies. Preliminary results from several runs of the model are included.

  14. Seawater reverse osmosis desalination and (harmful) algal blooms

    KAUST Repository

    Villacorte, Loreen O.

    2015-03-01

    This article reviews the occurrence of HABs in seawater, their effects on the operation of seawater reverse osmosis (SWRO) plants, the indicators for quantifying/predicting these effects, and the pretreatment strategies for mitigating operational issues during algal blooms. The potential issues in SWRO plants during HABs are particulate/organic fouling of pretreatment systems and biological fouling of RO membranes, mainly due to accumulation of algal organic matter (AOM). The presence of HAB toxins in desalinated water is also a potential concern but only at very low concentrations. Monitoring algal cell density, AOM concentrations and membrane fouling indices is a promising approach to assess the quality of SWRO feedwater and performance of the pretreatment system. When geological condition is favourable, subsurface intake can be a robust pretreatment for SWRO during HABs. Existing SWRO plants with open intake and are fitted with granular media filtration can improve performance in terms of capacity and product water quality, if preceded by dissolved air flotation or sedimentation. However, the application of advanced pretreatment using ultrafiltration membrane with in-line coagulation is often a better option as it is capable of maintaining stable operation and better RO feed water quality during algal bloom periods with significantly lower chemical consumption.

  15. 40 CFR 797.1050 - Algal acute toxicity test.

    Science.gov (United States)

    2010-07-01

    .... Also note any unusual cell shapes, color differences, flocculations, adherence of algae to test... 40 Protection of Environment 31 2010-07-01 2010-07-01 true Algal acute toxicity test. 797.1050... toxicity test. (a) Purpose. The guideline in this section is intended for use in developing data on...

  16. Export of algal biomass from the melting Arctic Sea ice

    NARCIS (Netherlands)

    Boetius, A.; Albrecht, S.; Bakker, K.; Bienhold, C.; Felden, J.; Fernández-Méndez, M.; Hendricks, S.; Katlein, C.; Lalande, C.; Krumpen, T.; Nicolaus, M.; Peeken, I.; Rabe, B.; Rogacheva, A.; Rybakova, E.; Somavilla, R.; Wenzhöfer, F.; Shipboard Science Party

    2013-01-01

    In the Arctic, under-ice primary production is limited to summer months and is restricted not only by ice thickness and snow cover but also by the stratification of the water column, which constrains nutrient supply for algal growth. Research Vessel Polarstern visited the ice-covered eastern-central

  17. Economic Gardening and the Grow Kentucky Program

    OpenAIRE

    2015-01-01

    In 2014, the Community and Economic Development Initiative of Kentucky (CEDIK) and the Kentucky Small Business Development Center (KSBDC), launched Grow Kentucky, Kentucky’s only certified Economic Gardening program. The program helps second-stage entrepreneurial growth companies penetrate existing markets, identify new markets, monitor competitors, track industry trends, locate customer clusters, use search engine optimization/social media for marketing and various other customized research....

  18. ROLE OF SURFACE WOUNDS AND BROWN ALGAL EPIPHYTES IN THE COLONIZATION OF ASCOPHYLLUM NODOSUM (PHAEOPHYCEAE) FRONDS BY VERTEBRATA LANOSA (RHODOPHYTA)(1).

    Science.gov (United States)

    Longtin, Caroline M; Scrosati, Ricardo A

    2009-06-01

    Ascophyllum nodosum (L.) Le Jol. forms extensive beds in wave-sheltered, rocky intertidal habitats on the northwestern Atlantic coast. This fucoid seaweed is host to an obligate red algal epiphyte, Vertebrata lanosa (L.) T. A. Chr. [=Polysiphonia lanosa (L.) Tandy], and two facultative brown algal epiphytes, Elachista fucicola (Velley) Aresch. and Pylaiella littoralis (L.) Kjellm. Although V. lanosa can occur throughout most of the length of host fronds, it largely predominates in midfrond segments. The two brown algal epiphytes are restricted to distal segments. Through field experiments conducted in Nova Scotia, Canada, we tested the hypothesis that surface wounds are required for the colonization of distal segments of host fronds by V. lanosa. Distal tissues normally have a smooth surface because of their young age (A. nodosum fronds grow apically). By creating small wounds that mimicked grazing wounds distributed elsewhere on host fronds, we demonstrated that V. lanosa can colonize distal frond segments during the growth and reproductive season (summer and autumn). Approximately half of the artificial wounds were colonized by V. lanosa during this time. The experimental exclusion of both brown algal epiphytes from distal frond segments did not affect colonization by V. lanosa. Thus, we conclude that the absence of surface irregularities on distal segments of host fronds, specifically small wounds, is the main factor explaining the absence of V. lanosa there. We propose that further experimental work clarifying epiphyte distribution in host beds will enhance our ability to understand the functional role of epiphytes in intertidal ecosystems.

  19. The extended Kalman filter for forecast of algal bloom dynamics.

    Science.gov (United States)

    Mao, J Q; Lee, Joseph H W; Choi, K W

    2009-09-01

    A deterministic ecosystem model is combined with an extended Kalman filter (EKF) to produce short term forecasts of algal bloom and dissolved oxygen dynamics in a marine fish culture zone (FCZ). The weakly flushed FCZ is modelled as a well-mixed system; the tidal exchange with the outer bay is lumped into a flushing rate that is numerically determined from a three-dimensional hydrodynamic model. The ecosystem model incorporates phytoplankton growth kinetics, nutrient uptake, photosynthetic production, nutrient sources from organic fish farm loads, and nutrient exchange with a sediment bed layer. High frequency field observations of chlorophyll, dissolved oxygen (DO) and hydro-meteorological parameters (sampling interval Deltat=1 day, 2h, 1h, respectively) and bi-weekly nutrient data are assimilated into the model to produce the combined state estimate accounting for the uncertainties. In addition to the water quality state variables, the EKF incorporates dynamic estimation of algal growth rate and settling velocity. The effectiveness of the EKF data assimilation is studied for a wide range of sampling intervals and prediction lead-times. The chlorophyll and dissolved oxygen estimated by the EKF are compared with field data of seven algal bloom events observed at Lamma Island, Hong Kong. The results show that the EKF estimate well captures the nonlinear error evolution in time; the chlorophyll level can be satisfactorily predicted by the filtered model estimate with a mean absolute error of around 1-2 microg/L. Predictions with 1-2 day lead-time are highly correlated with the observations (r=0.7-0.9); the correlation stays at a high level for a lead-time of 3 days (r=0.6-0.7). Estimated algal growth and settling rates are in accord with field observations; the more frequent DO data can compensate for less frequent algal biomass measurements. The present study is the first time the EKF is successfully applied to forecast an entire algal bloom cycle, suggesting the

  20. Growing media constituents determine the microbial nitrogen conversions in organic growing media for horticulture.

    Science.gov (United States)

    Grunert, Oliver; Reheul, Dirk; Van Labeke, Marie-Christine; Perneel, Maaike; Hernandez-Sanabria, Emma; Vlaeminck, Siegfried E; Boon, Nico

    2016-05-01

    Vegetables and fruits are an important part of a healthy food diet, however, the eco-sustainability of the production of these can still be significantly improved. European farmers and consumers spend an estimated €15.5 billion per year on inorganic fertilizers and the production of N-fertilizers results in a high carbon footprint. We investigated if fertilizer type and medium constituents determine microbial nitrogen conversions in organic growing media and can be used as a next step towards a more sustainable horticulture. We demonstrated that growing media constituents showed differences in urea hydrolysis, ammonia and nitrite oxidation and in carbon dioxide respiration rate. Interestingly, mixing of the growing media constituents resulted in a stimulation of the function of the microorganisms. The use of organic fertilizer resulted in an increase in amoA gene copy number by factor 100 compared to inorganic fertilizers. Our results support our hypothesis that the activity of the functional microbial community with respect to nitrogen turnover in an organic growing medium can be improved by selecting and mixing the appropriate growing media components with each other. These findings contribute to the understanding of the functional microbial community in growing media and its potential role towards a more responsible horticulture.

  1. Beach-goer behavior during a retrospectively detected algal ...

    Science.gov (United States)

    Algal blooms occur among nutrient rich, warm surface waters and may adversely impact recreational beaches. During July – September 2003, a prospective study of beachgoers was conducted on weekends at a public beach on a Great Lake in the United States. We measured each beachgoer’s activity at the start and end of their beach visit and the environmental factors: water and air temperature, wind speed and wave height at the study site each day. At the time, there was no notification of algal blooms; we retrospectively evaluated the presence of algal blooms using MERIS data from the Envisat-1 satellite. A total of 2840 people participated in the study over 16 study days. The majority (55%) were female, and 751 (26%) were < 18 years of age. An algal bloom was detected retrospectively by remotely sensed satellite imagery during August 16 – 24. This peak bloom period (PB) included 4 study days. During PB study days, more study participants 226/742 (31%) reported body contact with the water compared to contact 531/2098 (25%) on non-peak days. During the 4 PB days, of the environmental factors, only mean water temperature was significantly different, 250 C vs. 230 C (p<0.05) from other days.These results suggest that beachgoer body contact with water was not deterred by the presence of an algal bloom, and that interventions to actively discourage water contact during a bloom are needed to reduce exposure to blooms. This is an abstract of a proposed presentation and

  2. Translocation of microbenthic algal assemblages used for In situ analysis of metal pollution in rivers

    Science.gov (United States)

    Ivorra; Hettelaar; Tubbing; Kraak; Sabater; Admiraal

    1999-07-01

    Effects of metal pollution from a zinc factory on microbenthic algal communities were assessed in three neighboring streams on the Dutch-Belgian border. Diatom species composition was experimentally related to water quality by transferring racks with colonized glass discs from a polluted stream to a reference stream and vice versa. The succession of species and the changes in biomass and metal accumulation were measured during experiments in spring, autumn, and winter. Metal concentrations and dry weight in translocated biofilms tended to conform with those in local biofilms within an incubation time of 14 to 18 days. Bray-Curtis similarity values from the different communities indicated that diatom communities responded more completely to the metal-polluted conditions than to the reference water quality. Cymbella minuta, Diatoma vulgare var. ehrenbergii, Navicula sp., and Melosira varians had a lower percentage in assemblages placed in the metal-polluted streams. In contrast, Pinnularia sp. and Neidium ampliatum decreased in assemblages from the polluted streams that were transferred to the reference stream. Achnanthes minutissima and Navicula seminulum (N. atomus) proliferated on any translocation, possibly reflecting an opportunistic strategy and a high tolerance for Zn and Cd. The behavior of the species in relation to metal pollution generally accorded with observations in the literature. However, it seems that metal tolerance is not the only selective factor, and other ecological variables may also influence the composition of microphytobenthic communities.http://link.springer-ny. com/link/service/journals/00244/bibs/37n1p19.html

  3. Nitrogen deposition fuels harmful algal blooms in the East China Sea

    Science.gov (United States)

    Mackey, K. R.; Kavanaugh, M.; Chien, C. T.; Chen, Y.; Glover, D. M.; Paytan, A.

    2015-12-01

    Chinese marginal seas support vast fisheries and vital economies, but their productivity is threatened by eutrophication and increasing harmful algal blooms (HABs). Here we provide direct experimental evidence that aerosol enrichment shifts seawater chemistry by increasing the ratio of N to phosphorus (N:P) and supports the growth of bloom-forming phytoplankton in the East China Sea. We use a combination of field-based aerosol addition incubation experiments, along with ocean color data on blooms dominated by different taxa to show that HAB forming dinoflagellates are particularly responsive to aerosol inputs. Moreover, we show that the effect of N deposition is strongest in offshore waters further from the Yangtze River outflow, consistent with the large anthropogenic flux of N from this source. This study shows the potential for aerosols to control N:P ratios in offshore waters and to shape the phytoplankton community, contributing to the success of bloom-forming organisms.

  4. Effectiveness of an anti-algal compound in eliminating an aquatic unicellular harmful algal Phaeocystis globosa

    Directory of Open Access Journals (Sweden)

    Huajun eZhang

    2016-04-01

    Full Text Available Phaeocystis globosa blooms can have negative effects on higher trophic levels in the marine ecosystem and consequently influence human activities. Strain KA22, identified as the bacterium Hahella, was isolated from coastal surface water and used to control P. globosa growth. A methanol extract from the bacteral cells showed strong algicidal activity. After purification, the compound showed a similar structure to prodigiosin when identified with Q-Exactive Orbitrap MS and nuclear magnetic resonance spectra. The compound showed algicidal activity against P. globosa with a 50% Lethal Dose (LD50 of 2.24 μg/mL. The prodigiosin was stable under heat and acid environment, and it could be degraded under alkaline environment and natural light condition. The growth rates of strain KA22 was fast in 2216E medium and the content of prodigiosin in this medium was more than 70 μg/mL after 16 h incubation. The compound showed particularly strong algicidal activity against Prorocentrum donghaiense, P. globosa and Heterosigma akashiwo, but having little effect on three other phytoplankton species tested. The results of our research could increase our knowledge on harmful algal bloom control compound and lead to further study on the mechanisms of the lysis effect on harmful algae.

  5. 海洋藻类病毒与赤潮防治%Marine Algal Viruses and Their Application in Red-tide Control

    Institute of Scientific and Technical Information of China (English)

    柏仕杰; 王慧; 郑天凌

    2012-01-01

    Viruses are the most abundant biological entities in the oceans, and in the global oceans there are about 1030 viruses, whose hosts included almost all marine organisms, from bacteria to large marine animals. Marine viruses play a critical role in controlling community composition and impacting global biogeochemical cycles, and in addition, viruses can manipulate the metabolism of their hosts through horizontal gene transfer (HGT). Algal viruses can control red-tide by lysing algae. With the continuous development of algal virus research, a large of algal viruses were isolated, including the double-stranded or single-stranded DNA viruses and RNA viruses, and these algal viruses distribute in the cytoplasm or nuclei. The current development in the research of marine viruses and the ecological importance of marine viruses were summarized in this paper. Algal viruses were focused, including the prokaryotic algal viruses, the eukaryotic algal viruses, and the biological relationship between marine algal viruses and red-tide. Some achievements obtained by using algal viruses to control red-tide in the interaction between alga and algal viruses were introduced. The prospect of application of algal viruses in controlling red tide was forecasted. In China, the study on algal viruses has just started and will attract more and more attention in the near future.%病毒是海洋中丰度最高的生物,全球海洋中大约有1030个病毒,海洋病毒的宿主包括从细菌到大型海洋生物等几乎所有的海洋生物.海洋病毒在调控种群结构及生物地球化学循环中起着至关重要的作用,并且,病毒可以通过水平基因转移来操控宿主的代谢活动.藻类病毒能够通过裂解藻类从而起到控制赤潮的作用.随着藻类病毒研究的不断发展,人们已经分离到大量的藻类病毒,包括双链或单链的DNA病毒及RNA病毒,其分布于细胞质或细胞核中本文简要概述了海洋病毒研究方面的发展现

  6. Growing for different ends.

    Science.gov (United States)

    Catts, Oron; Zurr, Ionat

    2014-11-01

    Tissue engineering and regenerative biology are usually discussed in relation to biomedical research and applications. However, hand in hand with developments of this field in the biomedical context, other approaches and uses for non-medical ends have been explored. There is a growing interest in exploring spin off tissue engineering and regenerative biology technologies in areas such as consumer products, art and design. This paper outlines developments regarding in vitro meat and leather, actuators and bio-mechanic interfaces, speculative design and contemporary artistic practices. The authors draw on their extensive experience of using tissue engineering for non-medical ends to speculate about what lead to these applications and their possible future development and uses. Avoiding utopian and dystopian postures and using the notion of the contestable, this paper also mentions some philosophical and ethical consideration stemming from the use of non-medical approaches to tissue constructs. This article is part of a directed issue entitled: Regenerative Medicine: the challenge of translation.

  7. Melting ice, growing trade?

    Directory of Open Access Journals (Sweden)

    Sami Bensassi

    2016-05-01

    Full Text Available Abstract Large reductions in Arctic sea ice, most notably in summer, coupled with growing interest in Arctic shipping and resource exploitation have renewed interest in the economic potential of the Northern Sea Route (NSR. Two key constraints on the future viability of the NSR pertain to bathymetry and the future evolution of the sea ice cover. Climate model projections of future sea ice conditions throughout the rest of the century suggest that even under the most “aggressive” emission scenario, increases in international trade between Europe and Asia will be very low. The large inter-annual variability of weather and sea ice conditions in the route, the Russian toll imposed for transiting the NSR, together with high insurance costs and scarce loading/unloading opportunities, limit the use of the NSR. We show that even if these obstacles are removed, the duration of the opening of the NSR over the course of the century is not long enough to offer a consequent boost to international trade at the macroeconomic level.

  8. Fermentation of de-oiled algal biomass by Lactobacillus casei for production of lactic acid.

    Science.gov (United States)

    Overbeck, Tom; Steele, James L; Broadbent, Jeff R

    2016-12-01

    De-oiled algal biomass (algal cake) generated as waste byproduct during algal biodiesel production is a promising fermentable substrate for co-production of value-added chemicals in biorefinery systems. We explored the ability of Lactobacillus casei 12A to ferment algal cake for co-production of lactic acid. Carbohydrate and amino acid availability were determined to be limiting nutritional requirements for growth and lactic acid production by L. casei. These nutritional requirements were effectively addressed through enzymatic hydrolysis of the algal cake material using α-amylase, cellulase (endo-1,4-β-D-glucanase), and pepsin. Results confirm fermentation of algal cake for production of value-added chemicals is a promising avenue for increasing the overall cost competiveness of the algal biodiesel production process.

  9. A Technical College Grow-Your-Own Leadership Program

    Science.gov (United States)

    Scott, Ken; Sanders-McBryde, Tennie

    2012-01-01

    With the retirement of baby boomers (born 1946-1964) looming, considerable discussion and research has been conducted into succession planning and the educational impact from the loss of these leadership skills and experiences in community colleges. To prepare for this eventuality, many community colleges have begun Grow-Your-Own (GYO) leadership…

  10. How Do Galaxies Grow?

    Science.gov (United States)

    2008-08-01

    Astronomers have caught multiple massive galaxies in the act of merging about 4 billion years ago. This discovery, made possible by combining the power of the best ground- and space-based telescopes, uniquely supports the favoured theory of how galaxies form. ESO PR Photo 24/08 ESO PR Photo 24/08 Merging Galaxies in Groups How do galaxies form? The most widely accepted answer to this fundamental question is the model of 'hierarchical formation', a step-wise process in which small galaxies merge to build larger ones. One can think of the galaxies forming in a similar way to how streams merge to form rivers, and how these rivers, in turn, merge to form an even larger river. This theoretical model predicts that massive galaxies grow through many merging events in their lifetime. But when did their cosmological growth spurts finish? When did the most massive galaxies get most of their mass? To answer these questions, astronomers study massive galaxies in clusters, the cosmological equivalent of cities filled with galaxies. "Whether the brightest galaxies in clusters grew substantially in the last few billion years is intensely debated. Our observations show that in this time, these galaxies have increased their mass by 50%," says Kim-Vy Tran from the University of Zürich, Switzerland, who led the research. The astronomers made use of a large ensemble of telescopes and instruments, including ESO's Very Large Telescope (VLT) and the Hubble Space Telescope, to study in great detail galaxies located 4 billion light-years away. These galaxies lie in an extraordinary system made of four galaxy groups that will assemble into a cluster. In particular, the team took images with VIMOS and spectra with FORS2, both instruments on the VLT. From these and other observations, the astronomers could identify a total of 198 galaxies belonging to these four groups. The brightest galaxies in each group contain between 100 and 1000 billion of stars, a property that makes them comparable

  11. BIOTECHNOLOGY IN FRUIT GROWING

    Directory of Open Access Journals (Sweden)

    Z. Jurković

    2008-09-01

    Full Text Available Research studies in the area of biotechnologies in fruit growing started at the Agricultural Institute Osijek in 2006 with the establishment of the first experimental in vitro laboratory for micropropagation. The laboratory started an active research related to the Project "Biotechnological methods in fruit tree identification, selection and propagation" Project is part of program "Preservation and revitalization of grape and fruit autochthonous cultivars". The goal of this research is to determine genetic differences between autochthonous and introduced cultivars of cherry as well as cultivars and types of sour cherry, to find and optimize a method for fast recovery of clonal material. A great number of cherry cultivars and types within the population of cv. Oblacinska sour cherry exists in Croatia. A survey with the purpose of selecting autochthonous cultivars for further selection has been done in previous research. Differences have been found in a number of important agronomic traits within the populations of cv. Oblačinska sour cherry. Autochthonous cherry cultivars are suspected to be synonyms of known old cultivars which were introduced randomly and have been naturalized under a local name. Identification and description of cultivars and types of fruits is based on special visible properties which were measurable or notable. In this approach difficulties arise from the effect of non-genetic factors on expression of certain traits. Genetic-physiological problem of S allele autoincompatibility exists within cherry cultivars. Therefore it is necessary to put different cultivars in the plantation to pollinate each other. Apart form the fast and certain sort identification independent of environmental factors, biotechnological methods based on PCR enable faster virus detection compared with classical serologic methods and indexing and cover a wider range of plant pathogens including those undetectable by other methods. Thermotherapy and

  12. Growing Galaxies Gently

    Science.gov (United States)

    2010-10-01

    New observations from ESO's Very Large Telescope have, for the first time, provided direct evidence that young galaxies can grow by sucking in the cool gas around them and using it as fuel for the formation of many new stars. In the first few billion years after the Big Bang the mass of a typical galaxy increased dramatically and understanding why this happened is one of the hottest problems in modern astrophysics. The results appear in the 14 October issue of the journal Nature. The first galaxies formed well before the Universe was one billion years old and were much smaller than the giant systems - including the Milky Way - that we see today. So somehow the average galaxy size has increased as the Universe has evolved. Galaxies often collide and then merge to form larger systems and this process is certainly an important growth mechanism. However, an additional, gentler way has been proposed. A European team of astronomers has used ESO's Very Large Telescope to test this very different idea - that young galaxies can also grow by sucking in cool streams of the hydrogen and helium gas that filled the early Universe and forming new stars from this primitive material. Just as a commercial company can expand either by merging with other companies, or by hiring more staff, young galaxies could perhaps also grow in two different ways - by merging with other galaxies or by accreting material. The team leader, Giovanni Cresci (Osservatorio Astrofisico di Arcetri) says: "The new results from the VLT are the first direct evidence that the accretion of pristine gas really happened and was enough to fuel vigorous star formation and the growth of massive galaxies in the young Universe." The discovery will have a major impact on our understanding of the evolution of the Universe from the Big Bang to the present day. Theories of galaxy formation and evolution may have to be re-written. The group began by selecting three very distant galaxies to see if they could find evidence

  13. Connecting Florida Bay algal blooms to freshwater nutrient sources

    Science.gov (United States)

    Blakey, T.; Melesse, A. M.

    2013-12-01

    In this study, monthly water quality data collected in the Everglades by the Southeast Environmental Research Center (SERC) and the South Florida Water Management District (SFWMD) from 1991 to 2008 at 28 sampling stations distributed across Florida Bay was analyzed within the context of local geomorphology and seasonal wind and current regimes in order to evaluate the feasibility of the various purported nutrient sources for reoccurring algal blooms. The in situ chlorophyll-a (chl-a) measurements from the SERC dataset were evaluated as the indicator of algal biomass. Significant differences in average monthly chl-a concentrations at stations indicated a seasonality of algal blooms in the north central and west areas that is not evidenced in stations exhibiting low levels of chl-a throughout the typical year. Tukey's pairwise comparisons of monthly chl-a indicated, at the 95% confidence level, peak algal biomass occurs in October and November at the end of the wet season with minimums occurring between February and August depending on the location of the station. By month comparison of chl-a levels across stations suggest seasonal trends in the geographic focus and extent of blooms. Significant differences from Tukey's pairwise comparisons at the 95% confidence level showed stations to the west as having higher levels of chl-a in March through May with north central stations dominating from June to January. The month of February shows no significant difference in chl-a levels across this area. The results support hypotheses centering on a western source of nutrients that are delivered to the bay over the course of the rainy season. Mapping water quality sampling station locations on top of the bathymetry of Florida Bay illustrates the importance of considering coastal morphology in explaining trends in estuarine algal blooms. Coastal geomorphology along with seasonal changes in the direction of winds and magnitude of rains are demonstrated to be the predominant

  14. Screening and identification of early warning algal species for metal contamination in fresh water bodies polluted from point and non-point sources.

    Science.gov (United States)

    Rai, U N; Dubey, Smita; Shukla, O P; Dwivedi, S; Tripathi, R D

    2008-09-01

    The water bodies of Lucknow, Unnao and Kanpur (U.P.), India polluted through various point and non point sources were found to be either eutrophic or oligotrophic in nature. These water bodies supported a great number of algal diversity, which varied seasonally depending upon the physico-chemical properties of water. Further, the water bodies polluted through non point sources supports diverse algal species, while the water bodies polluted through point sources supports growth of tolerant blue green algae. High biomass producing algal species growing in these water bodies have accumulated significant amount of metals in their tissues. Maximum amount of Fe was found accumulated by species of Oedogonium sp. II (20,523.00 microg g(-1) dw) and Spirogyra sp. I (4,520.00 microg g(-1) dw), while maximum Chromium (Cr) was found accumulated in Phormedium bohneri (2,109.00 microg g(-1) dw) followed by Oscillatoria nigra (1,957.88 microg g(-1) dw) and Oedogonium sp. I (156.00 microg g(-1) dw) and Ni in Ulothrix sp. (495.00 microg g(-1) dw). Results showed that some of these forms growing in polluted environment and accumulating high amounts of toxic metals may be used as bioindicator species, however, their performance in metal contaminated water under different ecological niche is to be ascertained.

  15. Dredging impact on an urbanized Florida bayou: effects on benthos and algal-periphyton.

    Science.gov (United States)

    Lewis, M A; Weber, D E; Stanley, R S; Moore, J C

    2001-01-01

    Environmental effects of dredging events have been uncommonly reported for shallow, residential estuaries characteristic of the Gulf of Mexico region. The objective of this study was to determine the impact of hydraulic dredging on an urbanized estuary. Physicochemical quality, benthic community composition, whole sediment toxicity, periphytic algal community composition and trace metal tissue quality were determined prior to and after dredging. The effects on surface water pH, dissolved oxygen, and temperature were negligible but photosynthetically active radiation was decreased at several stations. Dredging significantly reduced benthic diversity and density (P < 0.05). However, the sediments were not acutely toxic to the epibenthic, Americamysis bahia (formerly Mysidopsis bahia); survival averaged 93% (post-dredging) and to 98% (pre-dredging). There were several post-dredging taxonomic structural changes in the diatom-dominated, periphyton community but differences in mean density and three diversity indices were not significant. Trace metal concentration in periphyton after dredging were reduced from an average of 4-65% and significantly for mercury, zinc and chromium in several areas. It was concluded that the environmental impact of small-scale dredging events in urbanized near-coastal areas, based on the selected parameters, are likely to be localized and of short-term environmental consequence. The choice of the target biota, response parameters and chemical analysis are important considerations in the environmental impact assessment of these periodic episodic events.

  16. Phenolic Content and Antioxidant Capacity in Algal Food Products

    Directory of Open Access Journals (Sweden)

    Ludmila Machu

    2015-01-01

    Full Text Available The study objective was to investigate total phenolic content using Folin-Ciocalteu’s method, to assess nine phenols by HPLC, to determine antioxidant capacity of the water soluble compounds (ACW by a photochemiluminescence method, and to calculate the correlation coefficients in commercial algal food products from brown (Laminaria japonica, Eisenia bicyclis, Hizikia fusiformis, Undaria pinnatifida and red (Porphyra tenera, Palmaria palmata seaweed, green freshwater algae (Chlorella pyrenoidosa, and cyanobacteria (Spirulina platensis. HPLC analysis showed that the most abundant phenolic compound was epicatechin. From spectrophotometry and ACW determination it was evident that brown seaweed Eisenia bicyclis was the sample with the highest phenolic and ACW values (193 mg·g−1 GAE; 7.53 µmol AA·g−1, respectively. A linear relationship existed between ACW and phenolic contents (r = 0.99. Some algal products seem to be promising functional foods rich in polyphenols.

  17. Algal Lipid Extraction and Upgrading to Hydrocarbons Technology Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Ryan; Biddy, Mary J.; Jones, Susanne B.

    2013-03-31

    In support of the Bioenergy Technologies Office, the National Renewable Energy Laboratory (NREL) and the Pacific Northwest National Laboratory (PNNL) are undertaking studies of biomass conversion technologies to identify barriers and target research toward reducing conversion costs. Process designs and preliminary economic estimates for each of these pathway cases were developed using rigorous modeling tools (Aspen Plus and Chemcad). These analyses incorporated the best information available at the time of development, including data from recent pilot and bench-scale demonstrations, collaborative industrial and academic partners, and published literature and patents. This technology pathway case investigates the cultivation of algal biomass followed by further lipid extraction and upgrading to hydrocarbon biofuels. Technical barriers and key research needs have been assessed in order for the algal lipid extraction and upgrading pathway to be competitive with petroleum-derived gasoline, diesel and jet range hydrocarbon blendstocks.

  18. Algal polycultures enhance coproduct recycling from hydrothermal liquefaction.

    Science.gov (United States)

    Godwin, Casey M; Hietala, David C; Lashaway, Aubrey R; Narwani, Anita; Savage, Phillip E; Cardinale, Bradley J

    2017-01-01

    The aim of this study was to determine if polycultures of algae could enhance tolerance to aqueous-phase coproduct (ACP) from hydrothermal liquefaction (HTL) of algal biomass to produce biocrude. The growth of algal monocultures and polycultures was characterized across a range ACP concentrations and sources. All of the monocultures were either killed or inhibited by 2% ACP, but polycultures of the same species were viable at up to 10%. The addition of ACP increased the growth rate (up to 25%) and biomass production (53%) of polycultures, several of which were more productive in ACP than any monoculture was in the presence or absence of ACP. These results suggest that a cultivation process that applies biodiversity to nutrient recycling could produce more algae with less fertilizer consumption.

  19. Algal biomass production and carbon fixation from flue gas

    Institute of Scientific and Technical Information of China (English)

    WANG Ling; ZHU Jing

    2016-01-01

    Algal biofuel has established as one of renewable energy. In this study, Nannochloropsis salina was cultured to test feasibility of biomass production and CO2 fixation from flue gas. Firstly, cultivation was conducted under different light intensity. Results showed that the highest dry biomass of 1.25±0.061 g/L was achieved at light intensity of 10klux, while the highest total lipids was 33.677±1.9% at light intensity of 15klux. The effect of mercury on algae growth was also investigated, the algae growth was serious limited at the presence of mercury, and there was no any difference at the range of 10-50 ug/m3. These results provide useful information for algal biomass production and CO2 fixation from flue gas.

  20. A Taste of Algal Genomes from the Joint Genome Institute

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, Alan; Grigoriev, Igor

    2012-06-17

    Algae play profound roles in aquatic food chains and the carbon cycle, can impose health and economic costs through toxic blooms, provide models for the study of symbiosis, photosynthesis, and eukaryotic evolution, and are candidate sources for bio-fuels; all of these research areas are part of the mission of DOE's Joint Genome Institute (JGI). To date JGI has sequenced, assembled, annotated, and released to the public the genomes of 18 species and strains of algae, sampling almost all of the major clades of photosynthetic eukaryotes. With more algal genomes currently undergoing analysis, JGI continues its commitment to driving forward basic and applied algal science. Among these ongoing projects are the pan-genome of the dominant coccolithophore Emiliania huxleyi, the interrelationships between the 4 genomes in the nucleomorph-containing Bigelowiella natans and Guillardia theta, and the search for symbiosis genes of lichens.

  1. Export of algal biomass from the melting Arctic sea ice.

    Science.gov (United States)

    Boetius, Antje; Albrecht, Sebastian; Bakker, Karel; Bienhold, Christina; Felden, Janine; Fernández-Méndez, Mar; Hendricks, Stefan; Katlein, Christian; Lalande, Catherine; Krumpen, Thomas; Nicolaus, Marcel; Peeken, Ilka; Rabe, Benjamin; Rogacheva, Antonina; Rybakova, Elena; Somavilla, Raquel; Wenzhöfer, Frank

    2013-03-22

    In the Arctic, under-ice primary production is limited to summer months and is restricted not only by ice thickness and snow cover but also by the stratification of the water column, which constrains nutrient supply for algal growth. Research Vessel Polarstern visited the ice-covered eastern-central basins between 82° to 89°N and 30° to 130°E in summer 2012, when Arctic sea ice declined to a record minimum. During this cruise, we observed a widespread deposition of ice algal biomass of on average 9 grams of carbon per square meter to the deep-sea floor of the central Arctic basins. Data from this cruise will contribute to assessing the effect of current climate change on Arctic productivity, biodiversity, and ecological function.

  2. Phytoplankton as Particles - A New Approach to Modeling Algal Blooms

    Science.gov (United States)

    2013-07-01

    Photosynthetic rate (g C g-1 Chl d-1) CChl = Carbon-to-chlorophyll ratio (g C g-1 chlorophyll a) PRSP = Active respiration (0 < PRSP < 1) BM...Basal metabolism The photosynthetic rate is influenced by ambient light, temperature, and nutrient concentration as described by Cerco (2000...particles in grid cell i Bi,P = Algal biomass attached to particle P in grid cell i (g C) V = Volume of grid cell i Particle-based photosynthetic rate

  3. Coastal engineering and Harmful Algal Blooms along Alexandria coast, Egypt

    Directory of Open Access Journals (Sweden)

    Amany A. Ismael

    2014-01-01

    The phytoplankton composition and its standing crop became totally different during the two periods. The most important bloom was caused by Micromonas pusilla forming a heavy green tide accompanied by a bloom of Peridinium quinquecorne. Although there were no fish or invertebrate mortality, this bloom caused economic losses to internal tourism. In the absence of any Environmental Assessment, the coastal engineering works increased the harmful algal blooms in Alexandria coastal waters, even after corrective steps were taken to mitigate the harmful effects.

  4. Floating Ice-Algal Aggregates below melting Arctic Sea Ice

    OpenAIRE

    Philipp Assmy; Jens K. Ehn; Mar Fernández-Méndez; Haakon Hop; Christian Katlein; Arild Sundfjord; Katrin Bluhm; Malin Daase; Anja Engel; Agneta Fransson; Granskog, Mats A.; Hudson, Stephen R.; Svein Kristiansen; Marcel Nicolaus; Ilka Peeken

    2013-01-01

    During two consecutive cruises to the Eastern Central Arctic in late summer 2012, we observed floating algal aggregates in the melt-water layer below and between melting ice floes of first-year pack ice. The macroscopic (1 – 15 cm in diameter) aggregates had a mucous consistency and were dominated by typical ice-associated pennate diatoms embedded within the mucous matrix. Aggregates maintained buoyancy and accumulated just above a strong pycnocline that separated meltwater and seawater layer...

  5. Selective algicidal action of peptides against harmful algal bloom species.

    Directory of Open Access Journals (Sweden)

    Seong-Cheol Park

    Full Text Available Recently, harmful algal bloom (HAB, also termed "red tide", has been recognized as a serious problem in marine environments according to climate changes worldwide. Many novel materials or methods to prevent HAB have not yet been employed except for clay dispersion, in which can the resulting sedimentation on the seafloor can also cause alteration in marine ecology or secondary environmental pollution. In the current study, we investigated that antimicrobial peptide have a potential in controlling HAB without cytotoxicity to harmless marine organisms. Here, antimicrobial peptides are proposed as new algicidal compounds in combating HAB cells. HPA3 and HPA3NT3 peptides which exert potent antimicrobial activity via pore forming action in plasma membrane showed that HPA3NT3 reduced the motility of algal cells, disrupted their plasma membrane, and induced the efflux of intracellular components. Against raphidoflagellate such as Heterosigma akashiwo, Chattonella sp., and C. marina, it displayed a rapid lysing action in cell membranes at 1~4 µM within 2 min. Comparatively, its lysing effects occurred at 8 µM within 1 h in dinoflagellate such as Cochlodium polykrikoides, Prorocentrum micans, and P. minimum. Moreover, its lysing action induced the lysis of chloroplasts and loss of chlorophyll a. In the contrary, this peptide was not effective against Skeletonema costatum, harmless algal cell, even at 256 µM, moreover, it killed only H. akashiwo or C. marina in co-cultivation with S. costatum, indicating to its selective algicidal activity between harmful and harmless algal cells. The peptide was non-hemolytic against red blood cells of Sebastes schlegeli, the black rockfish, at 120 µM. HAB cells were quickly and selectively lysed following treatment of antimicrobial peptides without cytotoxicity to harmless marine organisms. Thus, the antibiotic peptides examined in our study appear to have much potential in effectively controlling HAB with minimal

  6. Raman microspectroscopy based sensor of algal lipid unsaturation

    Science.gov (United States)

    Samek, Ota; Pilát, Zdeněk; Jonáš, Alexandr; Zemánek, Pavel; Šerý, Mojmír; Ježek, Jan; Bernatová, Silvie; Nedbal, Ladislav; Trtílek, Martin

    2011-05-01

    Raman spectroscopy is a powerful tool for chemical analysis. This technique can elucidate fundamental questions about the metabolic processes and intercellular variability on a single cell level. Therefore, Raman spectroscopy can significantly contribute to the study and use of microalgae in systems biology and biofuel technology. Raman spectroscopy can be combined with optical tweezers. We have employed microfluidic system to deliver the sampled microalgae to the Raman-tweezers. This instrument is able to measure chemical composition of cells and to track metabolic processes in vivo, in real-time and label-free making it possible to detect population variability in a wide array of traits. Moreover, employing an active sorting switch, cells can be separated depending on input parameters obtained from Raman spectra. We focus on algal lipids which are promising potential products for biofuel as well as for nutrition. Important parameter characterizing the algal lipids is the degree of unsaturation of the constituent fatty acids. We demonstrate the capacity of our Raman tweezers based sensor to sort cells according to the degree of unsaturation in lipid storage bodies of individual living algal cells.

  7. Harmful Algal in Banyuasin Coastal Waters, South Sumatera

    Directory of Open Access Journals (Sweden)

    Riris Aryawati

    2016-09-01

    Full Text Available Phytoplankton have important as food-chain major component and primary production of marine environment. However, high abundance of phytoplankton could give harmful effects toward water ecosystem. Moreover, they could produce toxic substances that will be accumulated within their consumer. This accumulation could be dangerous for human or animals.This research were aimed to determine and calculatespecies of harmful algae in Banyuasin coastal waters. The study was conducted on April, June, August, October and December of 2013, and in February 2014, at ten stations. Phytoplankton samples were taken vertically using plankton nets. In the form of cone-shaped with a diameter of 30 cm, length 100 cm and mesh size 30 μm.The result showed that there are 35 genera of phytoplankton. That have been found and consisted of four groups; Bacillariophyceae, Dinophyceae, Cyanophyceae and Chlorophyceae. 13 species were identified as Harmful Algal (Chaetoceros, Coscinodiscus, Nitzschia, Skeletonema, Thalassiosira, Alexandrium, Ceratium, Dinophysis, Noctiluca, Protoperidinium, Prorocentrum, Anabaena dan Oscillatoria, with seven of them were known for having toxin (Nitzschia, Alexandrium, Dinophysis, Protoperidinium Prorocentrum, Anabaena and Oscillatoria. Monitoring result showed that the highest number of species of potential harmful algal blooms (HABs occured in June and the highest abundance occured in August, especially Chaetoceros and Skeletonema.How to CiteAryawati, R., Bengen, D. G., Prartono, T., & Zulkifli, H. (2016. Harmful Algal in Banyuasin Coastal Waters, South Sumatera. Biosaintifika: Journal of Biology & Biology Education, 8(2, 231-239.

  8. Biological control of harmful algal blooms: A modelling study

    Science.gov (United States)

    Solé, Jordi; Estrada, Marta; Garcia-Ladona, Emilio

    2006-07-01

    A multispecies dynamic simulation model (ERSEM) was used to examine the influence of allelopathic and trophic interactions causing feeding avoidance by predators, on the formation of harmful algal blooms, under environmental scenarios typical of a Mediterranean harbour (Barcelona). The biological state variables of the model included four functional groups of phytoplankton (diatoms, toxic and non-toxic flagellates and picophytoplankton), heterotrophic flagellates, micro- and mesozooplankton and bacteria. The physical-chemical forcing (irradiance, temperature and major nutrient concentrations) was based on an actual series of measurements taken along a year cycle in the Barcelona harbour. In order to evaluate potential effects of advection, some runs were repeated after introducing a biomass loss term. Numerical simulations showed that allelopathic effects of a toxic alga on a non-toxic but otherwise similar competitor did not have appreciable influence on the dynamics of the system. However, induction of avoidance of the toxic alga by predators, which resulted on increased predation pressure on other algal groups had a significant effect on the development of algal and predator populations. The presence of advection overrided the effect of these interactions and only allowed organisms with sufficiently high potential growth rates to thrive.

  9. Floating ice-algal aggregates below melting arctic sea ice.

    Science.gov (United States)

    Assmy, Philipp; Ehn, Jens K; Fernández-Méndez, Mar; Hop, Haakon; Katlein, Christian; Sundfjord, Arild; Bluhm, Katrin; Daase, Malin; Engel, Anja; Fransson, Agneta; Granskog, Mats A; Hudson, Stephen R; Kristiansen, Svein; Nicolaus, Marcel; Peeken, Ilka; Renner, Angelika H H; Spreen, Gunnar; Tatarek, Agnieszka; Wiktor, Jozef

    2013-01-01

    During two consecutive cruises to the Eastern Central Arctic in late summer 2012, we observed floating algal aggregates in the melt-water layer below and between melting ice floes of first-year pack ice. The macroscopic (1-15 cm in diameter) aggregates had a mucous consistency and were dominated by typical ice-associated pennate diatoms embedded within the mucous matrix. Aggregates maintained buoyancy and accumulated just above a strong pycnocline that separated meltwater and seawater layers. We were able, for the first time, to obtain quantitative abundance and biomass estimates of these aggregates. Although their biomass and production on a square metre basis was small compared to ice-algal blooms, the floating ice-algal aggregates supported high levels of biological activity on the scale of the individual aggregate. In addition they constituted a food source for the ice-associated fauna as revealed by pigments indicative of zooplankton grazing, high abundance of naked ciliates, and ice amphipods associated with them. During the Arctic melt season, these floating aggregates likely play an important ecological role in an otherwise impoverished near-surface sea ice environment. Our findings provide important observations and measurements of a unique aggregate-based habitat during the 2012 record sea ice minimum year.

  10. Direct and indirect effects of high pCO2 on algal grazing by coral reef herbivores from the Gulf of Aqaba (Red Sea)

    Science.gov (United States)

    Borell, E. M.; Steinke, M.; Fine, M.

    2013-12-01

    Grazing on marine macroalgae is a key structuring process for coral reef communities. However, ocean acidification from rising atmospheric CO2 concentrations is predicted to adversely affect many marine animals, while seaweed communities may benefit and prosper. We tested how exposure to different pCO2 (400, 1,800 and 4,000 μatm) may affect grazing on the green alga Ulva lactuca by herbivorous fish and sea urchins from the coral reefs in the northern Gulf of Aqaba (Red Sea), either directly, by changing herbivore behaviour, or indirectly via changes in algal palatability. We also determined the effects of pCO2 on algal tissue concentrations of protein and the grazing-deterrent secondary metabolite dimethylsulfoniopropionate (DMSP). Grazing preferences and overall consumption were tested in a series of multiple-choice feeding experiments in the laboratory and in situ following exposure for 14 d (algae) and 28 d (herbivores). 4,000 μatm had a significant effect on the biochemical composition and palatability of U. lactuca. No effects were observed at 1,800 relative to 400 μatm (control). Exposure of U. lactuca to 4,000 μatm resulted in a significant decrease in protein and increase in DMSP concentration. This coincided with a reduced preference for these algae by the sea urchin Tripneustes gratilla and different herbivorous fish species in situ (Acanthuridae, Siganidae and Pomacanthidae). No feeding preferences were observed for the rabbitfish Siganus rivulatus under laboratory conditions. Exposure to elevated pCO2 had no direct effect on the overall algal consumption by T. gratilla and S. rivulatus. Our results show that CO2 has the potential to alter algal palatability to different herbivores which could have important implications for algal abundance and coral community structure. The fact that pCO2 effects were observed only at a pCO2 of 4,000 μatm, however, indicates that algal-grazer interactions may be resistant to predicted pCO2 concentrations in the

  11. Utilization of lipid extracted algal biomass and sugar factory wastewater for algal growth and lipid enhancement of Ettlia sp.

    Science.gov (United States)

    Moon, Myounghoon; Kim, Chul Woong; Farooq, Wasif; Suh, William I; Shrivastav, Anupama; Park, Min S; Mishra, Sanjiv K; Yang, Ji-Won

    2014-07-01

    The present study assessed the use of hydrolysate of lipid extracted algal biomass (LEA) combined with the sugar factory wastewater (SFW) as a low cost nutrient and a carbon source, respectively for microalgal cultivation. Microalgal strain Ettlia sp. was both mixotrophically and heterotrophically cultivated using various amounts of hydrolysate and SFW. The culture which was grown in medium containing 50% LEA hydrolysate showed highest growth, achieving 5.26 ± 0.14 gL(-1) after 12 days of cultivation. The addition of SFW increased the lipid productivity substantially from 5.8 to 95.5 mg L(-1)d(-1) when the culture medium was fortified with 20% SFW. Gas chromatography analysis indicated a noticeable increase of 20% in C16 and C18 fraction in FAME distribution under above condition. Therefore, it can be concluded that the combination of LEA hydrolysate and sugar factory waste water can be a powerful growth medium for economical algal cultivation.

  12. Evaluating algal growth performance and water use efficiency of pilot-scale revolving algal biofilm (RAB) culture systems.

    Science.gov (United States)

    Gross, Martin; Mascarenhas, Vernon; Wen, Zhiyou

    2015-10-01

    A Revolving Algal Biofilm (RAB) growth system in which algal cells are attached to a flexible material rotating between liquid and gas phases has been developed. In this work, different configurations of RAB systems were developed at pilot-scale by retrofitting the attachment materials to a raceway pond (2000-L with 8.5 m(2) footprint area) and a trough reservoir (150 L with 3.5 m(2) footprint area). The algal growth performance and chemical composition, as well as the water evaporative loss and specific water consumption were evaluated over a period of nine months in a greenhouse environment near Boone, Iowa USA. Additionally a raceway pond was run in parallel, which served as a control. On average the raceway-based RAB and the trough-based RAB outperformed the control pond by 309% and 697%, respectively. A maximum productivity of 46.8 g m(-2) day(-1) was achieved on the trough-based RAB system. The evaporative water loss of the RAB system was modeled based on an energy balance analysis and was experimentally validated. While the RAB system, particularly the trough-based RAB, had higher water evaporative loss, the specific water consumption per unit of biomass produced was only 26% (raceway-based RAB) and 7% (trough-based RAB) of that of the control pond. Collectively, this research shows that the RAB system is an efficient algal culture system and has great potential to commercially produce microalgae with high productivity and efficient water use.

  13. Synergistic effects of UVR and simulated stratification on commensalistic algal-bacterial relationship in two optically contrasting oligotrophic Mediterranean lakes

    Science.gov (United States)

    Carrillo, P.; Medina-Sánchez, J. M.; Durán, C.; Herrera, G.; Villafañe, V. E.; Helbling, E. W.

    2014-08-01

    An indirect effect of global warming is the shallowing epilimnion, causing organisms to be exposed to higher levels of ultraviolet (UVR, 280-400 nm) and photosynthetically active radiation (PAR, 400-700 nm), which could affect primary and bacterial production as well as the commensalistic algal-bacterial relationship. The combined effects of UVR and reduction in the depth of the upper mixed layer (UML) were assessed on variables related to the metabolism of algae and bacteria, during in situ experiments performed with natural microplanktonic communities from two oligotrophic lakes with contrasting UVR-transparency (clear vs. opaque) of southern Spain. The negative UVR effects on epilimnetic primary production (PP) and on heterotrophic bacterial production (HBP), intensified by high mean irradiances, were higher in the UVR-opaque than in the UVR-clear lake, and stronger on the algae than on the heterotrophic bacterial communities. Under UVR and high mean irradiance, the algal-bacterial relationship was strengthened in the UVR-clear lake, where excreted organic carbon (EOC) rates exceeded the bacterial carbon demand (BCD). This did not occur in the UVR-opaque lake. The greater UVR damage to algae and bacteria and the weakening of their commensalistic interaction found in the UVR-opaque lake indicates that these ecosystems would be especially vulnerable to stressors related to global change. Thus, our findings may have important implications for the carbon cycle in oligotrophic lakes of the Mediterranean region.

  14. Nitrogen deposition to lakes in national parks of the western Great Lakes region: Isotopic signatures, watershed retention, and algal shifts

    Science.gov (United States)

    Hobbs, William O.; Lafrancois, Brenda Moraska; Stottlemyer, Robert; Toczydlowski, David; Engstrom, Daniel R.; Edlund, Mark B.; Almendinger, James E.; Strock, Kristin E.; VanderMeulen, David; Elias, Joan E.; Saros, Jasmine E.

    2016-03-01

    Atmospheric deposition is a primary source of reactive nitrogen (Nr) to undisturbed watersheds of the Great Lakes region of the U.S., raising concerns over whether enhanced delivery over recent decades has affected lake ecosystems. The National Atmospheric Deposition Program (NADP) has been measuring Nr deposition in this region for over 35 years. Here we explore the relationships among NADP-measured Nr deposition, nitrogen stable isotopes (δ15N) in lake sediments, and the response of algal communities in 28 lakes situated in national parks of the western Great Lakes region of the U.S. We find that 36% of the lakes preserve a sediment δ15N record that is statistically correlated with some form of Nr deposition (total dissolved inorganic N, nitrate, or ammonium). Furthermore, measured long-term (since 1982) nitrogen biogeochemistry and inferred critical nitrogen loads suggest that watershed nitrogen retention and climate strongly affect whether sediment δ15N is related to Nr deposition in lake sediment records. Measurements of algal change over the last ~ 150 years suggest that Nr deposition, in-lake nutrient cycling, and watershed inputs are important factors affecting diatom community composition, in addition to direct climatic effects on lake physical limnology. The findings suggest that bulk sediment δ15N does reflect Nr deposition in some instances. In addition, this study highlights the interactive effects of Nr deposition and climate variability.

  15. Effects of different fertilization models on the characteristics of weed communities during the rice growing seasons%不同施肥模式下水稻生育期间杂草群落特征

    Institute of Scientific and Technical Information of China (English)

    董春华; 刘强; 高菊生; 徐明岗; 文石林; 曾希柏

    2013-01-01

    An investigation was made at a double-rice paddy field set up in 1982 in the Red Soil Field Experimental Station,CAAS,China to study the species and biomass of weeds growing during the rice (Oryza sativa) growing seasons.Over a 30-year period,organic,chemical,and a mixed organic and inorganic fertiliser were applied with the same rates of nitrogen (N),phosphorus (P),and potassium (K).Compared with other treatments,long-term application of mixed fertiliser resulted in the least number of weed species in both rice growing seasons.Organic fertiliser application resulted in the greatest number of weed species in the early rice growing season,while treatment without fertiliser application resulted in the greatest number in the late growing season:4.4% and 39.3% higher than the former two respectively.Long-term application of organic fertiliser resulted in the highest biomass of weeds in both seasons,10.7%,4.5% and 37.7% higher than the applications of mixed,chemical,and no fertiliser respectively.Long-term application of organic fertiliser resulted in the highest biomass of all weeds and floating weeds in the early season,the treatment without fertiliser application resulted in the highest biomass of both in the late season,while mixed fertiliser application resulted in the highest biomass of floating weeds in both seasons.Soil alkali-hydrolyzable N and available P were positively correlated with the dry mass of weeds (r=0.465,P<0.05 and r=0.517,P<0.05,respectively),and of wet weeds (r=0.482,P<0.05 and r=0.542,P<0.05,respectively).Dry mass of floating weeds was positively correlated with soil available P (r=0.666,P<0.01),and was negatively correlated with soil pH (r=0.516,P<0.01).Soil available P,under the co-effects of soil pH,alkali-hydrolyzable N and other factors,had an indirect effect on the dry mass of weeds.If effective control of the growth of wet and floating weeds in red soil paddy of south China is to be attempted by achieving a

  16. Harmful algal blooms: a case study in two mesotrophic drinking water supply reservoirs in South Carolina

    Science.gov (United States)

    Journey, Celeste A.; Beaulieu, Karen M.; Knight, Rodney R.; Graham, Jennifer L.; Arrington, Jane M.; West, Rebecca; Westcott, John; Bradley, Paul M.

    2010-01-01

    Algal blooms can be harmful and a nuisance in a variety of aquatic ecosystems, including reservoirs and lakes. Cyanobacterial(blue-green algae) harmful algal blooms are notorious for producing both taste-and-odor compounds and potent toxins that may affect human health. Taste–and-odor episodes are aesthetic problems often caused by cyanobacterial-produced organic compounds (geosmin and methylisoborneol) and are common in reservoirs and lakes used as source water supplies. The occurrences of these taste-and-odor compounds and toxins (like microcystin) can be sporadic and vary in intensity both spatially and temporally. Recent publications by the U.S. Geological Survey address this complexity and provide protocols for cyanotoxin and taste-and-odor sampling programs. A case study conducted by the U.S. Geological Survey, in cooperation with Spartanburg Water, monitored two mesotrophic reservoirs that serve as public drinking water supplies in South Carolina. Study objectives were (1) to identify spatial and temporal occurrence of the taste-and-odor compound geosmin and the cyanotoxin microcystin and (2) to assess the associated limnological conditions before, during, and after these occurrences. Temporal and spatial occurrence of geosmin and microcystin were highly variable from 2007 to 2009. The highest geosmin concentrations tended to occur in the spring. Microcystin tended to occur in the late summer and early fall, but occurrence was rare and well below World Health Organization guidelines for finished drinking water and recreational activities. No current U.S. Environmental Protection Agency standards are applicable to cyanotoxins in drinking or ambient water. In general, elevated geosmin and microcystin concentrations were the result of complex interactions between cyanobacterial ⬚community composition, nutrient availability, water clarity, hydraulic residence time, and stratification.

  17. Among-habitat algal selectivity by browsing herbivores on an inshore coral reef

    Science.gov (United States)

    Loffler, Zoe; Bellwood, David R.; Hoey, Andrew S.

    2015-06-01

    Understanding how the impact of different herbivores varies spatially on coral reefs is important in qualifying the resistance of coral reefs to disturbance events and identifying the processes that structure algal communities. We used assays of six common macroalgae ( Acanthophora spicifera, Caulerpa taxifolia, Galaxaura rugosa, Laurencia sp. Sargassum sp., and Turbinaria ornata) and remote underwater video cameras to quantify herbivory in two habitats (reef crest and slope) across multiple sites on Orpheus Island, Great Barrier Reef. Rates of herbivory varied among macroalgal taxa, habitats, and sites. Reductions in algal biomass were greatest for Sargassum sp. (36 % 4 h-1), intermediate for A. spicifera, Laurencia sp., C. taxifolia, and T. ornata (17-33 % 4 h-1) and lowest for G. rugosa (6 % 4 h-1). Overall, rates of herbivory were generally greater on the reef crest (30 % 4 h-1) than the reef slope (21 % 4 h-1). This difference in rates of herbivory coincided with a marked shift in the dominant herbivores between habitats. Kyphosus vaigiensis, despite only feeding on three species of macroalgae ( Sargassum sp., T. ornata, and A. spicifera), was responsible for 34 % of all bites recorded on the reef crest yet did not take a single bite from algae on the reef slope. In contrast, Siganus doliatus took bites on every species of algae in both habitats, accounting for 40 % of bites on the reef crest and 74 % of all bites recorded on the reef slope. This difference in the number of macroalgal species targeted by herbivores and the habitat/s in which they feed adds another dimension of complexity to our understanding of coral reef herbivore dynamics.

  18. Dynamics of Weed Community among Three Growing Seasons in Alpine Cultivated Grassland%高寒地区人工草地年际间的杂草群落动态

    Institute of Scientific and Technical Information of China (English)

    顾梦鹤; 霍国飞; 王涛; 杜国桢

    2011-01-01

    本试验选取青藏高原常见多年生牧草垂穗披碱草(Elymus nutans)、中华羊茅(Festuca sinensis)和羊茅(FPstuca ovina)建植人工草地,设计7种播种组合,4个密度水平,通过3年的野外样方调查,分析了人工草地中杂草丰富度和杂草生物量的变化规律.结果表明:人工草地建植当年,共出现30种杂草,其中附地菜(Trigonotis peduncularis)、萼果香薷(Elsholtzia patrini)、白藜(Chenopodium album)、宝盖草(Lamium amplexicaule)等一年生阔叶杂草对草地影响较大;人工草地建植第2年,杂草丰富度最低(19种),对草地影响较大的是萼果香薷、甘青蒿(Artemisia tangutica)、车前(Plantago asiatica)及臭蒿(Artemisia hedinii)等多年生杂草;人工草地建植第3年,草地的杂草丰富度最高(40种).对草地影响较大的有甘青蒿、车前和老鹳草(Geranium wil fordii)以及草石蚕(Humata tyermanni)等多年生杂草.中华羊茅和羊茅草地抵制杂草的能力在建植当年(2003年)最弱,2004年和2005年之后逐渐增强;垂穗披碱草抵制杂草的能力在建植当年(2003年)最强,2004年和2005年以后随着建植时间的增加而逐渐减弱.%Weed abundance and biomass among three perennial grasses (Elymus nutans, Festuca sinensis, and Festuca ovina) cultivated widely in the east Qinghai-Tibetan plateau were studied. Seven different sowing methods and four density levels were used in the experiment. Field quadrats were tracked and investigated for three years. Results showed 30 kinds of weeds in the cultivated grassland during first growing season. Annual broadleaf weeds, such as Trigonotis peduncularis, Chenopodium album, Elsholtzia patrini, and Lamium amplexicaule had considerable impact on the cultivated grassland. In the second growing season, weed abundance was the lowest (19 kinds) among three years. Perennial weeds, such as Chenopodium album 、Artemisia tangutica 、and Asiatic plantain had impact on the cultivated grassland. In the

  19. Algal growth inhibition test in filled, closed bottles for volatile and sorptive materials

    DEFF Research Database (Denmark)

    Mayer, Philipp; Nyholm, Niels; Verbruggen, Eric M. J.;

    2000-01-01

    Exposure concentrations of many hydrophobic substances are difficult to maintain in algal growth inhibition tests performed in open agitated flasks. This is partly because such compounds tend to volatilize from aqueous solution and partly because of sorption to the algal biomass as well as to the......Exposure concentrations of many hydrophobic substances are difficult to maintain in algal growth inhibition tests performed in open agitated flasks. This is partly because such compounds tend to volatilize from aqueous solution and partly because of sorption to the algal biomass as well...... as to the test container. A simple filled closed bottle test with low algal densities and bicarbonate enrichment is described here as an approach to minimize the loss of test material from solution. The algal medium was enriched with 300 mg NaHCO3/L, the pH was adjusted to 7.0 by addition of HCl...

  20. Opportunities for Switzerland to Contribute to the Production of Algal Biofuels: the Hydrothermal Pathway to Bio-Methane.

    Science.gov (United States)

    Bagnoud-Velásquez, Mariluz; Refardt, Dominik; Vuille, François; Ludwig, Christian

    2015-01-01

    Microalgae have a significant potential to be a sustainable source of fuel and thus are of interest in the transition to a sustainable energy system, in particular for resource-dependent countries such as Switzerland. Independence of fossil fuels, considerable reduction of CO(2) emissions, and abandoning nuclear energy may be possible with an integrated system approach including the sourcing of biofuels from different types of biomass. Today, a full carbon-to-fuel conversion is possible, and has been recently demonstrated with an advanced hydrothermal technology. The potential to develop algal biofuels is viewed as high thanks to the possibility they offer to uncouple bioenergy from food production. Nevertheless, technological breakthroughs must take place before commercial production becomes a reality, especially to meet the necessary cost savings and efficiency gains in the algae cultivation structure. In addition, an integrated management of waste resources to promote the nutrient recovery appears today as imperative to further improve the economic viability and the environmental sustainability of algal production. We provide here a review that includes the global technological status of both algae production and their conversion into biofuels in order to understand first the added value of algal energy in general before we focus on the potential of algae to contribute specifically to the Swiss energy system to the horizon 2050. In this respect, the hydrothermal conversion pathway of microalgal biomass into synthetic natural gas (SNG) is emphasized, as research into this technology has received considerable attention in Switzerland during the last decade. In addition, SNG is a particularly relevant fuel in the Swiss context due to the existing gas grid and to the opportunity it offers to cover a wide spectrum of energy applications, in particular cogeneration of heat and electricity or use as a transport fuel in the growing gas car fleet.

  1. Growing Up on an Appalachian Farm.

    Science.gov (United States)

    Holston, Ezra C; Callen, Bonnie

    2017-01-01

    Background Research on centenarians to date has focused on areas with a high population of centenarians. However, there is limited literature on centenarians' perspectives about growing up on farms from the heartland of Appalachia in Eastern Tennessee. Purpose This qualitative descriptive study was designed to characterize the role of a farming childhood by exploring the viewpoints of community-dwelling centenarians who grew up on farms in south central Appalachia. Methods A qualitative descriptive design was used with a convenience sample ( n = 16). Cognitive status was determined with the Short Portable Mental Status Questionnaire. Demographic data were collected. Interviews were transcribed and analyzed with the Neuendorf method of content analysis. Results Main emerging themes were the farm, the family, and the environment. Conclusion The farm was at the center of these centenarians' childhood, influencing their family, community relations, and social interactions, which provided lessons that they utilized throughout their long lives.

  2. Fatty acids and algal lipids as precursors of chlorination by-products

    Institute of Scientific and Technical Information of China (English)

    Yan Liang; Yuen Shan Lui; Huachang Hong

    2012-01-01

    Six common algal fatty acids (FAs) with different numbers of double bonds,lipophilic fractions and proteins extracted from the diatom Navicula pelliculosa and algal cells were chlorinated to evaluate their potential in generating disinfection by-products (DBPs).The result showed that the more double bonds in the FAs,the higher the amounts of chloroform and dichloroacetic acid (DCAA) produced,but such a pattern was not observed for trichloroacetic acid (TCAA).Based on the previously reported composition of fatty acids in algal lipids,the DBP generation potentials of algal lipids were calculated.These predicted values were much lower than those measured in the chlorinated algal lipophilic fraction,suggesting unknown lipophilic fraction(s) served as potent DBPs precursors.Another calculation attempted to predict DBP production in algal cells based on algal lipid and protein composition,given quantified measured DBP production per unit algal lipid and proteins.The analysis showed that the observed DBP production was similar to that predicted (< 35% difference),suggesting that algal biochemical compositions may serve as a bioindicator for preliminary estimation of chloroform,DCAA and TCAA formation upon chlorinating algae.

  3. "Something good can grow here": chicago urban agriculture food projects.

    Science.gov (United States)

    Hatchett, Lena; Brown, Loretta; Hopkins, Joan; Larsen, Kelly; Fournier, Eliza

    2015-01-01

    Food security is a challenge facing many African-American low-income communities nationally. Community and university partners have established urban agriculture programs to improve access to high quality affordable fruits and vegetables by growing, distributing, and selling food in urban neighborhoods. While the challenge of food security is within communities of color, few studies have described these urban agriculture programs and documented their impact on the crew members who work in the programs and live in the low-income communities. More information is needed on the program impact for crew and community health promotion. Using a survey and focus group discussion from the crew and staff we describe the program and activities of four Chicago Urban Agriculture programs. We summarized the impact these programs have on crew members' perception of urban agriculture, health habits, community engagement, and community health promotion in low-income African-American neighborhoods.

  4. Copper removal by algal biomass: biosorbents characterization and equilibrium modelling.

    Science.gov (United States)

    Vilar, Vítor J P; Botelho, Cidália M S; Pinheiro, José P S; Domingos, Rute F; Boaventura, Rui A R

    2009-04-30

    The general principles of Cu(II) binding to algal waste from agar extraction, composite material and algae Gelidium, and different modelling approaches, are discussed. FTIR analyses provided a detailed description of the possible binding groups present in the biosorbents, as carboxylic groups (D-glucuronic and pyruvic acids), hydroxyl groups (cellulose, agar and floridean starch) and sulfonate groups (sulphated galactans). Potentiometric acid-base titrations showed a heterogeneous distribution of two major binding groups, carboxyl and hydroxyl, following the quasi-Gaussian affinity constant distribution suggested by Sips, which permitted to estimate the maximum amount of acid functional groups (0.36, 0.25 and 0.1 mmol g(-1)) and proton binding parameters (pK(H)=5.0, 5.3 and 4.4; m(H)=0.43, 0.37, 0.33), respectively for algae Gelidium, algal waste and composite material. A non-ideal, semi-empirical, thermodynamically consistent (NICCA) isotherm fitted better the experimental ion binding data for different pH values and copper concentrations, considering only the acid functional groups, than the discrete model. Values of pK(M) (3.2; 3.6 and 3.3), n(M) (0.98, 0.91, 1.0) and p (0.67, 0.53 and 0.43) were obtained, respectively for algae Gelidium, algal waste and composite material. NICCA model reflects the complex macromolecular systems that take part in biosorption considering the heterogeneity of the biosorbent, the competition between protons and metals ions to the binding sites and the stoichiometry for different ions.

  5. Copper removal by algal biomass: Biosorbents characterization and equilibrium modelling

    Energy Technology Data Exchange (ETDEWEB)

    Vilar, Vitor J.P. [LSRE-Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)], E-mail: vilar@fe.up.pt; Botelho, Cidalia M.S. [LSRE-Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)], E-mail: cbotelho@fe.up.pt; Pinheiro, Jose P.S.; Domingos, Rute F. [Centro de Biomedicina Molecular e Estrutural, Department of Chemistry and Biochemistry, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal); Boaventura, Rui A.R. [LSRE-Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)], E-mail: bventura@fe.up.pt

    2009-04-30

    The general principles of Cu(II) binding to algal waste from agar extraction, composite material and algae Gelidium, and different modelling approaches, are discussed. FTIR analyses provided a detailed description of the possible binding groups present in the biosorbents, as carboxylic groups (D-glucuronic and pyruvic acids), hydroxyl groups (cellulose, agar and floridean starch) and sulfonate groups (sulphated galactans). Potentiometric acid-base titrations showed a heterogeneous distribution of two major binding groups, carboxyl and hydroxyl, following the quasi-Gaussian affinity constant distribution suggested by Sips, which permitted to estimate the maximum amount of acid functional groups (0.36, 0.25 and 0.1 mmol g{sup -1}) and proton binding parameters (pK{sup '}{sub H}=5.0,5.3and4.4;m{sub H} = 0.43, 0.37, 0.33), respectively for algae Gelidium, algal waste and composite material. A non-ideal, semi-empirical, thermodynamically consistent (NICCA) isotherm fitted better the experimental ion binding data for different pH values and copper concentrations, considering only the acid functional groups, than the discrete model. Values of pK{sup '}{sub M} (3.2; 3.6 and 3.3), n{sub M} (0.98, 0.91, 1.0) and p (0.67, 0.53 and 0.43) were obtained, respectively for algae Gelidium, algal waste and composite material. NICCA model reflects the complex macromolecular systems that take part in biosorption considering the heterogeneity of the biosorbent, the competition between protons and metals ions to the binding sites and the stoichiometry for different ions.

  6. Dynamics of ellipsoidal tracers in swimming algal suspensions

    Science.gov (United States)

    Yang, Ou; Peng, Yi; Liu, Zhengyang; Tang, Chao; Xu, Xinliang; Cheng, Xiang

    2016-10-01

    Enhanced diffusion of passive tracers immersed in active fluids is a universal feature of active fluids and has been extensively studied in recent years. Similar to microrheology for equilibrium complex fluids, the unusual enhanced particle dynamics reveal intrinsic properties of active fluids. Nevertheless, previous studies have shown that the translational dynamics of spherical tracers are qualitatively similar, independent of whether active particles are pushers or pullers—the two fundamental classes of active fluids. Is it possible to distinguish pushers from pullers by simply imaging the dynamics of passive tracers? Here, we investigated the diffusion of isolated ellipsoids in algal C. reinhardtii suspensions—a model for puller-type active fluids. In combination with our previous results on pusher-type E. coli suspensions [Peng et al., Phys. Rev. Lett. 116, 068303 (2016), 10.1103/PhysRevLett.116.068303], we showed that the dynamics of asymmetric tracers show a profound difference in pushers and pullers due to their rotational degree of freedom. Although the laboratory-frame translation and rotation of ellipsoids are enhanced in both pushers and pullers, similar to spherical tracers, the anisotropic diffusion in the body frame of ellipsoids shows opposite trends in the two classes of active fluids. An ellipsoid diffuses fastest along its major axis when immersed in pullers, whereas it diffuses slowest along the major axis in pushers. This striking difference can be qualitatively explained using a simple hydrodynamic model. In addition, our study on algal suspensions reveals that the influence of the near-field advection of algal swimming flows on the translation and rotation of ellipsoids shows different ranges and strengths. Our work provides not only new insights into universal organizing principles of active fluids, but also a convenient tool for detecting the class of active particles.

  7. Algal 'greening' and the conservation of stone heritage structures.

    Science.gov (United States)

    Cutler, Nick A; Viles, Heather A; Ahmad, Samin; McCabe, Stephen; Smith, Bernard J

    2013-01-01

    In humid, temperate climates, green algae can make a significant contribution to the deterioration of building stone, both through unsightly staining ('greening') and, possibly, physical and chemical transformations. However, very little is known about the factors that influence the deteriorative impact and spatial distribution of green algal biofilms, hindering attempts to model the influence of climate change on building conservation. To address this problem, we surveyed four sandstone heritage structures in Belfast, UK. Our research had two aims: 1) to investigate the relationships between greening and the deterioration of stone structures and 2) to assess the impacts of environmental factors on the distribution of green biofilms. We applied an array of analytical techniques to measure stone properties indicative of deterioration status (hardness, colour and permeability) and environmental conditions related to algal growth (surface and sub-surface moisture, temperature and surface texture). Our results indicated that stone hardness was highly variable but only weakly related to levels of greening. Stone that had been exposed for many years was, on average, darker and greener than new stone of the same type, but there was no correlation between greening and darkening. Stone permeability was higher on 'old', weathered stone but not consistently related to the incidence of greening. However, there was evidence to suggest that thick algal biofilms were capable of reducing the ingress of moisture. Greening was negatively correlated with point measurements of surface temperature, but not moisture or surface texture. Our findings suggested that greening had little impact on the physical integrity of stone; indeed the influence of algae on moisture regimes in stone may have a broadly bioprotective action. Furthermore, the relationship between moisture levels and greening is not straightforward and is likely to be heavily dependent upon temporal patterns in moisture

  8. Assessment of Algal Farm Designs using a Dynamic Modular Approach

    Energy Technology Data Exchange (ETDEWEB)

    Abodeely, Jared M. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology; Stevens, Daniel M. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology; Ray, Allison E. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology; Newby, Deborah T. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology; Coleman, Andre M. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States). Hydrology Technical Group; Cafferty, Kara G. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology

    2014-07-01

    The notion of renewable energy provides an importantmechanism for diversifying an energy portfolio,which ultimately would have numerous benefits including increased energy resilience, reduced reliance on foreign energysupplies, reduced GHG emissions, development of a green energy sector that contributes to economic growth,and providing a sustainable energy supply. The conversion of autotrophic algae to liquid transportation fuels is the basis of several decades of research to competitively bring energy-scale production into reality; however, many challenges still remain for making algal biofuels economically viable. Addressing current challenges associatedwith algal production systems, in part, requires the ability to assess spatial and temporal variability, rapidly evaluate alternative algal production system designs, and perform large-scale assessments considering multiple scenarios for thousands of potential sites. We introduce the development and application of the Algae Logistics Model (ALM) which is tailored to help address these challenges. The flexible nature of the ALM architecture allows the model to: 1) interface with external biomass production and resource assessment models, as well as other relevant datasets including those with spatiotemporal granularity; 2) interchange design processes to enable operational and economic assessments ofmultiple design configurations, including the integration of current and new innovative technologies; and 3) conduct trade-off analysis to help understand the site-specific techno-economic trade-offs and inform technology decisions. This study uses the ALM to investigate a baseline open-pond production system determined by model harmonization efforts conducted by the U.S. Department of Energy. Six sites in the U.S. southern-tierwere sub-selected and assessed using daily site-specific algaebiomass productivity data to determine the economic viability of large-scale open-pond systems. Results show that costs can vary

  9. Assessment of Algal Farm Designs Using a Dynamic Modular Approach

    Energy Technology Data Exchange (ETDEWEB)

    Abodeely, Jared [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology; Coleman, Andre M. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States). Hydrology Technical Group; Stevens, Daniel M. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology; Ray, Allison E. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology; Cafferty, Kara G. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology; Newby, Deborah T. [Idaho National Laboratory (INL), Idaho Falls, ID (United States). Biofuels and Renewable Energy Technology

    2014-07-01

    The notion of renewable energy provides an important mechanism for diversifying an energy portfolio, which ultimately would have numerous benefits including increased energy resilience, reduction of foreign energy supplies, reduced GHG emissions, development of a green energy sector that contributes to economic growth, and providing a sustainable energy supply. The conversion of autotrophic algae to liquid transportation fuels is the basis of several decades of research to competitively bring energy-scale production into reality; however, many challenges still remain for making algal biofuels economically viable. Addressing current challenges associated with algal production systems, in part, requires the ability to assess spatial and temporal variability, rapidly evaluate alternative algal production system designs, and perform large-scale assessments considering multiple scenarios for thousands of potential sites. We introduce the Algae Logistics Model (ALM) which helps to address these challenges. The flexible nature of the ALM architecture allows the model to: 1) interface with external biomass production and resource assessment models, as well as other relevant datasets including those with spatiotemporal granularity; 2) interchange design processes to enable operational and economic assessments of multiple design configurations, including the integration of current and new innovative technologies; and 3) conduct trade-off analysis to help understand the site-specific techno-economic trade-offs and inform technology decisions. This study uses the ALM to investigate a baseline open-pond production system determined by model harmonization efforts conducted by the U.S. Department of Energy. Six sites in the U.S. southern-tier were sub-selected and assessed using daily site-specific algae biomass productivity data to determine the economic viability of large-scale open-pond systems. Results show that costs can vary significantly depending on location and biomass

  10. Biogas production from anaerobic digestion of Spirulina maxima algal biomass

    Energy Technology Data Exchange (ETDEWEB)

    Rejean Samson; Anh LeDuy

    1982-08-01

    Spirulina maxima algal biomass could be used as the sole nutrient for the production of biogas by anaerobic digestion process. It is relatively simple to adapt the municipal sewage sludge to this new substrate. The adapted sludge is very stable. Under nonoptimal conditions, the methane yield and productivity obtained were 0.26 m/sup 3//(kg VS added day) and 0.26 m/sup 3//(kg VS added day), respectively, with the semicontinuous, daily fed, anaerobic digestion having loading rate of 0.97 kg VS/(m/sup 3/ day), retention time of 33 days and temperature of 30/sup 0/C.

  11. Beneficial Effects of Marine Algal Compounds in Cosmeceuticals

    Directory of Open Access Journals (Sweden)

    Noel Vinay Thomas

    2013-01-01

    Full Text Available The name “cosmeceuticals” is derived from “cosmetics and pharmaceuticals”, indicating that a specific product contains active ingredients. Marine algae have gained much importance in cosmeceutical product development due to their rich bioactive compounds. In the present review, marine algal compounds (phlorotannins, sulfated polysaccharides and tyrosinase inhibitors have been discussed toward cosmeceutical application. In addition, atopic dermatitis and the possible role of matrix metalloproteinase (MMP in skin-related diseases have been explored extensively for cosmeceutical products. The proper development of marine algae compounds will be helpful in cosmeceutical product development and in the development of the cosmeceutical industry.

  12. Integral toxicity test of sea waters by an algal biosensor.

    Science.gov (United States)

    Tonnina, Daniele; Campanella, Luigi; Sammartino, Maria Pia; Visco, Giovanni

    2002-04-01

    An integral toxicity test, based on an algal biosensor and suitable to be used in sea water, is presented. The biosensor was designed and built by coupling a Clark oxygen electrode as transducer and the marine alga Spirulina subsalsa as biological mediator; it constitutes the "core" in a lab-scale prototype of a flow apparatus suitable to continuously monitor, in sea water, the photosynthetic activity of the alga and, from its variation, the marine pollution from the toxicological point of view. Inorganic pollutants (heavy metals) were tested in previous researches while organic ones (chlorophenols, pesticides and surfactants) are the object of the present paper.

  13. A study of algal biomass potential in selected Canadian regions.

    Energy Technology Data Exchange (ETDEWEB)

    Passell, Howard David; Roach, Jesse Dillon; Klise, Geoffrey T.

    2011-11-01

    A dynamic assessment model has been developed for evaluating the potential algal biomass and extracted biocrude productivity and costs, using nutrient and water resources available from waste streams in four regions of Canada (western British Columbia, Alberta oil fields, southern Ontario, and Nova Scotia). The purpose of this model is to help identify optimal locations in Canada for algae cultivation and biofuel production. The model uses spatially referenced data across the four regions for nitrogen and phosphorous loads in municipal wastewaters, and CO{sub 2} in exhaust streams from a variety of large industrial sources. Other data inputs include land cover, and solar insolation. Model users can develop estimates of resource potential by manipulating model assumptions in a graphic user interface, and updated results are viewed in real time. Resource potential by location can be viewed in terms of biomass production potential, potential CO{sub 2} fixed, biocrude production potential, and area required. The cost of producing algal biomass can be estimated using an approximation of the distance to move CO{sub 2} and water to the desired land parcel and an estimation of capital and operating costs for a theoretical open pond facility. Preliminary results suggest that in most cases, the CO{sub 2} resource is plentiful compared to other necessary nutrients (especially nitrogen), and that siting and prospects for successful large-scale algae cultivation efforts in Canada will be driven by availability of those other nutrients and the efficiency with which they can be used and re-used. Cost curves based on optimal possible siting of an open pond system are shown. The cost of energy for maintaining optimal growth temperatures is not considered in this effort, and additional research in this area, which has not been well studied at these latitudes, will be important in refining the costs of algal biomass production. The model will be used by NRC-IMB Canada to identify

  14. Metabolism of mutagenic polycyclic aromatic hydrocarbons by photosynthetic algal species.

    Science.gov (United States)

    Schoeny, R; Cody, T; Warshawsky, D; Radike, M

    1988-02-01

    Polycyclic aromatic hydrocarbons (PAH) known to produce carcinogenic and mutagenic effects have been shown to contaminate waters, sediments and soils. While it is accepted that metabolites of these compounds are responsible for most of their biological effects in mammals, their metabolism, and to a large extent their bioactivity, in aquatic plants have not been explored. Cultures of photosynthetic algal species were assayed for their ability to metabolize benzo[a]pyrene (BaP), a carcinogenic PAH under conditions which either permitted (white light) or disallowed (gold light) photooxidation of the compound. Growth of Selenastrum capricornutum, a fresh-water green alga, was completely inhibited when incubated in white light with 160 micrograms BaP/l medium. By contrast concentrations at the upper limit of BaP solubility in aqueous medium had no effect on algal growth when gold light was used. BaP quinones and phenol derivatives were found to inhibit growth of Selenastrum under white light incubation. BaP phototoxicity and metabolism were observed to be species-specific. All 3 tested species of the order Chlorococcales were growth-inhibited by BaP in white light whereas neither the green alga Chlamydomonas reinhardtii nor a blue-green, a yellow-green or an euglenoid alga responded in this fashion. Assays of radiolabeled BaP metabolism in Selenastrum showed that the majority of radioactivity associated with BaP was found in media as opposed to algal cell pellets, that the extent of metabolism was BaP concentration dependent, and that the proportion of various metabolites detected was a function of the light source. After gold light incubation, BaP diols predominated while after white light treatment at equal BaP concentrations, the 3,6-quinone was found in the highest concentration. Extracted material from algal cell pellets and from media was tested for mutagenicity in a forward mutation suspension assay in Salmonella typhimurium using resistance to 8-azaguanine for

  15. Marine harmful algal blooms, human health and wellbeing

    DEFF Research Database (Denmark)

    Berdalet, Elisa; Fleming, Lora E.; Gowen, Richard

    2016-01-01

    Microalgal blooms are a natural part of the seasonal cycle of photosynthetic organisms in marine ecosystems. They are key components of the structure and dynamics of the oceans and thus sustain the benefits that humans obtain from these aquatic environments. However, some microalgal blooms can...... cause harm to humans and other organisms. These harmful algal blooms (HABs) have direct impacts on human health and negative influences on human wellbeing, mainly through their consequences to coastal ecosystem services (fisheries, tourism and recreation) and other marine organisms and environments...

  16. A Collection of Algal Genomes from the JGI

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, Alan; Grigoriev, Igor

    2012-03-19

    Algae, defined as photosynthetic eukaryotes other than plants, constitute a major component of fundamental eukaryotic diversity. Acquisition of the ability to conduct oxygenic photosynthesis through endosymbiotic events has been a principal driver of eukaryotic evolution, and today algae continue to underpin aquatic food chains as primary producers. Algae play profound roles in the carbon cycle, can impose health and economic costs through toxic blooms, and are candidate sources for bio-fuels; all of these research areas are part of the mission of DOE?s Joint Genome Institute (JGI). A collection of algal projects ongoing at JGI contributes to each of these areas and illustrates analyses employed in their genome exploration.

  17. Method for growing plants aeroponically.

    Science.gov (United States)

    Zobel, R W; Del Tredici, P; Torrey, J G

    1976-03-01

    A simple, inexpensive system for growing plants with their roots bathed in nutrient mist is described. The aeroponics system uses a spinner from a home humidifier to propel nutrient solution into a polyethylene-lined plywood box atop which plants are supported on plastic light-fixture "egg crating." Success in growing a number of herbaceous and woody species, including nodulated legumes and nonlegumes, is reported.

  18. Harmful algal bloom smart device application: using image analysis and machine learning techniques for early classification of harmful algal blooms (SETAC presentation)

    Science.gov (United States)

    Reports of toxic cyanobacterial blooms, also known as Harmful Algal Blooms (HABS) have increased drastically in recent years. HABS impact human health from causing mild allergies to liver damage and death. The Ecological Stewardship Institute (ESI) at Northern Kentucky Universi...

  19. Process Design and Economics for the Conversion of Algal Biomass to Biofuels: Algal Biomass Fractionation to Lipid- and Carbohydrate-Derived Fuel Products

    Energy Technology Data Exchange (ETDEWEB)

    Davis, R.; Kinchin, C.; Markham, J.; Tan, E.; Laurens, L.; Sexton, D.; Knorr, D.; Schoen, P.; Lukas, J.

    2014-09-01

    Beginning in 2013, NREL began transitioning from the singular focus on ethanol to a broad slate of products and conversion pathways, ultimately to establish similar benchmarking and targeting efforts. One of these pathways is the conversion of algal biomass to fuels via extraction of lipids (and potentially other components), termed the 'algal lipid upgrading' or ALU pathway. This report describes in detail one potential ALU approach based on a biochemical processing strategy to selectively recover and convert select algal biomass components to fuels, namely carbohydrates to ethanol and lipids to a renewable diesel blendstock (RDB) product. The overarching process design converts algal biomass delivered from upstream cultivation and dewatering (outside the present scope) to ethanol, RDB, and minor coproducts, using dilute-acid pretreatment, fermentation, lipid extraction, and hydrotreating.

  20. Marine mimivirus relatives are probably large algal viruses

    Directory of Open Access Journals (Sweden)

    Claverie Jean-Michel

    2008-01-01

    Full Text Available Abstract Background Acanthamoeba polyphaga mimivirus is the largest known ds-DNA virus and its 1.2 Mb-genome sequence has revealed many unique features. Mimivirus occupies an independent lineage among eukaryotic viruses and its known hosts include only species from the Acanthamoeba genus. The existence of mimivirus relatives was first suggested by the analysis of the Sargasso Sea metagenomic data. Results We now further demonstrate the presence of numerous "mimivirus-like" sequences using a larger marine metagenomic data set. We also show that the DNA polymerase sequences from three algal viruses (CeV01, PpV01, PoV01 infecting different marine algal species (Chrysochromulina ericina, Phaeocystis pouchetii, Pyramimonas orientalis are very closely related to their homolog in mimivirus. Conclusion Our results suggest that the numerous mimivirus-related sequences identified in marine environments are likely to originate from diverse large DNA viruses infecting phytoplankton. Micro-algae thus constitute a new category of potential hosts in which to look for new species of Mimiviridae.

  1. Compatibility of hydroxypropyl-{beta}-cyclodextrin with algal toxicity bioassays

    Energy Technology Data Exchange (ETDEWEB)

    Fai, Patricia Bi; Grant, Alastair [School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ (United Kingdom); Reid, Brian J. [School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ (United Kingdom)], E-mail: b.reid@uea.ac.uk

    2009-01-15

    Numerous reports have indicated that hydrophobic organic compound bioaccessibility in sediment and soil can be determined by extraction using aqueous hydroxypropyl-{beta}-cyclodextrin (HPCD) solutions. This study establishes the compatibility of HPCD with Selenastrum capricornutum and assesses whether its presence influences the toxicity of reference toxicants. Algal growth inhibition (72 h) showed no significant (P > 0.05) difference at HPCD concentrations up to and including 20 mM. HPCD presence did not influence the toxicity of the inorganic reference toxicant (ZnSO{sub 4}), with IC50 values of 0.82 {mu}M and 0.85 {mu}M, in the presence and absence of HPCD (20 mM), respectively. However, HPCD presence (20 mM) reduced the toxicity of 2,4-dichlorophenol and the herbicides diuron and isoproturon. These reductions were attributed to inclusion complex formation between the toxicants and the HPCD cavity. Liberation of complexed toxicants, by sample manipulation prior to toxicity assessment, is proposed to provide a sensitive, high throughput, bioassay that reflects compound bioaccessibility. - Compatibility of the biomimetic HPCD extraction method with algal cell growth inhibition bioassays to assess toxicity of reference toxicants and environmental relevant herbicides.

  2. Dissolved organic matter reduces algal accumulation of methylmercury

    Science.gov (United States)

    Luengen, Allison C.; Fisher, Nicholas S.; Bergamaschi, Brian A.

    2012-01-01

    Dissolved organic matter (DOM) significantly decreased accumulation of methylmercury (MeHg) by the diatom Cyclotella meneghiniana in laboratory experiments. Live diatom cells accumulated two to four times more MeHg than dead cells, indicating that accumulation may be partially an energy-requiring process. Methylmercury enrichment in diatoms relative to ambient water was measured by a volume concentration factor (VCF). Without added DOM, the maximum VCF was 32 x 104, and the average VCF (from 10 to 72 h) over all experiments was 12.6 x 104. At very low (1.5 mg/L) added DOM, VCFs dropped by approximately half. At very high (20 mg/L) added DOM, VCFs dropped 10-fold. Presumably, MeHg was bound to a variety of reduced sulfur sites on the DOM, making it unavailable for uptake. Diatoms accumulated significantly more MeHg when exposed to transphilic DOM extracts than hydrophobic ones. However, algal lysate, a labile type of DOM created by resuspending a marine diatom in freshwater, behaved similarly to a refractory DOM isolate from San Francisco Bay. Addition of 67 μM L-cysteine resulted in the largest drop in VCFs, to 0.28 x 104. Although the DOM composition influenced the availability of MeHg to some extent, total DOM concentration was the most important factor in determining algal bioaccumulation of MeHg.

  3. Health benefits of algal polysaccharides in human nutrition.

    Science.gov (United States)

    Mišurcová, Ladislava; Škrovánková, Soňa; Samek, Dušan; Ambrožová, Jarmila; Machů, Ludmila

    2012-01-01

    The interest in functional food, both freshwater and marine algal products with their possible promotional health effects, increases also in regions where algae are considered as rather exotic food. Increased attention about algae as an abundant source of many nutrients and dietary fiber from the nutrition point of view, as well as from the scientific approaches to explore new nutraceuticals and pharmaceuticals, is based on the presence of many bioactive compounds including polysaccharides extracted from algal matter. Diverse chemical composition of dietary fiber polysaccharides is responsible for their different physicochemical properties, such as their ability to be fermented by the human colonic microbiota resulted in health benefit effects. Fundamental seaweed polysaccharides are presented by alginates, agars, carrageenans, ulvanes, and fucoidans, which are widely used in the food and pharmaceutical industry and also in other branches of industry. Moreover, freshwater algae and seaweed polysaccharides have emerged as an important source of bioactive natural compounds which are responsible for their possible physiological effects. Especially, sulfate polysaccharides exhibit immunomodulatory, antitumor, antithrombotic, anticoagulant, anti-mutagenic, anti-inflammatory, antimicrobial, and antiviral activities including anti-HIV infection, herpes, and hepatitis viruses. Generally, biological activity of sulfate polysaccharides is related to their different composition and mainly to the extent of the sulfation of their molecules. Significant attention has been recently focused on the use of both freshwater algae and seaweed for developing functional food by reason of a great variety of nutrients that are essential for human health.

  4. Plasticity of total and intracellular phosphorus quotas in Microcystis aeruginosa cultures and Lake Erie algal assemblages

    Directory of Open Access Journals (Sweden)

    Matthew A Saxton

    2012-01-01

    Full Text Available Blooms of the potentially toxic cyanobacterium Microcystis are common events globally, and as a result significant resources continue to be dedicated to monitoring and controlling these events. Recent studies have shown that a significant proportion total cell-associated phosphorus (P in phytoplankton can be surface adsorbed, and many of our current measurements do not accurately reflect the P demands of these organisms. In this study we measure the total cell-associated and intracellular P as well as growth rates of two toxic strains of Microcystis aeruginosa Kütz grown under a range of P concentrations. The results show that the intracellular P pool in Microcystis represents a percentage of total cell-associated P (50-90% similar to what has been reported for actively growing algae in marine systems. Intracellular P levels (39-147 fg cell-1 generally increased with increasing growth media P concentrations, but growth rate and the ratio of total cell-associated to intracellular P remained generally stable. Intracellular P quotas and growth rates in cells grown under the different P treatments illustrate the ability of this organism to successfully respond to changes in ambient P loads, and thus have implications for ecosystem scale productivity models employing P concentrations to predict algal bloom events.

  5. Different utilization of alginate and other algal polysaccharides by marine Alteromonas macleodii ecotypes.

    Science.gov (United States)

    Neumann, Anna M; Balmonte, John P; Berger, Martine; Giebel, Helge-Ansgar; Arnosti, Carol; Voget, Sonja; Simon, Meinhard; Brinkhoff, Thorsten; Wietz, Matthias

    2015-10-01

    The marine bacterium Alteromonas macleodii is a copiotrophic r-strategist, but little is known about its potential to degrade polysaccharides. Here, we studied the degradation of alginate and other algal polysaccharides by A. macleodii strain 83-1 in comparison to other A. macleodii strains. Cell densities of strain 83-1 with alginate as sole carbon source were comparable to those with glucose, but the exponential phase was delayed. The genome of 83-1 was found to harbour an alginolytic system comprising five alginate lyases, whose expression was induced by alginate. The alginolytic system contains additional CAZymes, including two TonB-dependent receptors, and is part of a 24 kb genomic island unique to the A. macleodii 'surface clade' ecotype. In contrast, strains of the 'deep clade' ecotype contain only a single alginate lyase in a separate 7 kb island. This difference was reflected in an eightfold greater efficiency of surface clade strains to grow on alginate. Strain 83-1 furthermore hydrolysed laminarin, pullulan and xylan, and corresponding polysaccharide utilization loci were detected in the genome. Alteromonas macleodii alginate lyases were predominantly detected in Atlantic Ocean metagenomes. The demonstrated hydrolytic capacities are likely of ecological relevance and represent another level of adaptation among A. macleodii ecotypes.

  6. Releasing Stored Solar Energy within Pond Scum: Biodiesel from Algal Lipids

    Science.gov (United States)

    Blatti, Jillian L.; Burkart, Michael D.

    2012-01-01

    Microalgae have emerged as an attractive feedstock for the mass production of renewable transportation fuels due to their fast growth rate, flexible habitat preferences, and substantial oil yields. As an educational tool, a laboratory was developed that mimics emerging algal biofuel technology, including the extraction of algal lipids and…

  7. Harmful Algal Blooms in Asia: an insidious and escalating water pollution phenomenon with effects on ecological and human health

    Directory of Open Access Journals (Sweden)

    Patricia M Glibert

    2014-02-01

    Full Text Available Harmful Algal Blooms (HABs, those proliferations of algae that causeenvironmental, economic, or human health problems, are increasing in frequency,duration, and geographic extent due to nutrient pollution. The scale of the HABproblem in Asia has escalated in recent decades in parallel with the increase in useof agricultural fertilizer, the development of aquaculture, and a growing population.Three examples, all from China but illustrative of the diversity of events and theirecological, economic, and human health effects throughout Asia, are highlightedhere. These examples include inland (Lake Tai or Taihu as well as offshore (EastChina Sea and Yellow Sea waters. The future outlook for controlling these bloomsis bleak. The effects of advancing industrialized agriculture and a continually growingpopulation will continue to result in more nutrient pollution and more HABs—-and more effects - in the foreseeable future.

  8. Validation of algal viability treated with total residual oxidant and organic matter by flow cytometry.

    Science.gov (United States)

    Lee, Junghyun; Choi, Eun Joo; Rhie, Kitae

    2015-08-15

    Algal cell growth after starch and oxidant treatments in seawater species (Isochrysis galbana and Phaeodactylum tricornutum) and freshwater species (Selenastrum capricornutum and Scenedesmus obliquus) were evaluated by flow cytometry with fluorescein diacetate (FDA) staining to determine algal viability. Growth of algal cell was found to be significantly different among groups treated with NaOCl, starch and/or sodium thiosulfate, which are active substance (Total Residual Oxidant; TRO as Cl2), organic compound to meet efficacy testing standard and neutralizer of TRO by Ballast Water Management Convention of International Maritime Organization, respectively. The viability of algal cell treated with TRO in starch-add culture of 5days after treatment and neutralization was decreased significantly. ATP contents of the treated algal cells corresponded to the FL1 fluorescent signal of flow cytometry with FDA staining. I. galbana was the most sensitive to TRO-neutralized cultures during viability analysis.

  9. Monitoring and removal of cyanobacterial toxins from drinking water by algal-activated carbon.

    Science.gov (United States)

    Ibrahim, Wael M; Salim, Emad H; Azab, Yahia A; Ismail, Abdel-Hamid M

    2016-10-01

    Microcystins (MCs) are the most potent toxins that can be produced by cyanobacteria in drinking water supplies. This study investigated the abundance of toxin-producing algae in 11 drinking water treatment plants (DWTPs). A total of 26 different algal taxa were identified in treated water, from which 12% were blue green, 29% were green, and 59% were diatoms. MC levels maintained strong positive correlations with number of cyanophycean cells in raw and treated water of different DWTPs. Furthermore, the efficiency of various algal-based adsorbent columns used for the removal of these toxins was evaluated. The MCs was adsorbed in the following order: mixed algal-activated carbon (AAC) ≥ individual AAC > mixed algal powder > individual algal powder. The results showed that the AAC had the highest efficient columns capable of removing 100% dissolved MCs from drinking water samples, thereby offering an economically feasible technology for efficient removal and recovery of MCs in DWTPs.

  10. Novel resource utilization of refloated algal sludge to improve the quality of organic fertilizer.

    Science.gov (United States)

    Huang, Yan; Li, Rong; Liu, Hongjun; Wang, Beibei; Zhang, Chenmin; Shen, Qirong

    2014-08-01

    Without further management, large amounts of refloated algal sludge from Taihu Lake to retrieve nitrogen and phosphorus resources may result in serious secondary environmental pollution. The possibility of utilization of algal sludge to improve the quality of organic fertilizer was investigated in this study. Variations of physicochemical properties, germination index (GI) and microcystin (MC) content were analysed during the composting process. The results showed that the addition of algal sludge improved the contents of nutrients, common free amino acids and total common amino acids in the novel organic fertilizer. Rapid degradation rates of MC-LR and MC-RR, a high GI value and more abundance of culturable protease-producing bacteria were observed during the composting process added with algal sludge. Growth experiments showed that the novel organic fertilizer efficiently promoted plant growth. This study provides a novel resource recovery method to reclaim the Taihu Lake algal sludge and highlights a novel method to produce a high-quality organic fertilizer.

  11. Resilience of coral-associated bacterial communities exposed to fish farm effluent.

    Directory of Open Access Journals (Sweden)

    Melissa Garren

    Full Text Available The coral holobiont includes the coral animal, algal symbionts, and associated microbial community. These microbes help maintain the holobiont homeostasis; thus, sustaining robust mutualistic microbial communities is a fundamental part of long-term coral reef survival. Coastal pollution is one major threat to reefs, and intensive fish farming is a rapidly growing source of this pollution.We investigated the susceptibility and resilience of the bacterial communities associated with a common reef-building coral, Porites cylindrica, to coastal pollution by performing a clonally replicated transplantation experiment in Bolinao, Philippines adjacent to intensive fish farming. Ten fragments from each of four colonies (total of 40 fragments were followed for 22 days across five sites: a well-flushed reference site (the original fragment source; two sites with low exposure to milkfish (Chanos chanos aquaculture effluent; and two sites with high exposure. Elevated levels of dissolved organic carbon (DOC, chlorophyll a, total heterotrophic and autotrophic bacteria abundance, virus like particle (VLP abundances, and culturable Vibrio abundance characterized the high effluent sites. Based on 16S rRNA clone libraries and denaturing gradient gel electrophoresis (DGGE analysis, we observed rapid, dramatic changes in the coral-associated bacterial communities within five days of high effluent exposure. The community composition on fragments at these high effluent sites shifted towards known human and coral pathogens (i.e. Arcobacter, Fusobacterium, and Desulfovibrio without the host corals showing signs of disease. The communities shifted back towards their original composition by day 22 without reduction in effluent levels.This study reveals fish farms as a likely source of pathogens with the potential to proliferate on corals and an unexpected short-term resilience of coral-associated bacterial communities to eutrophication pressure. These data highlight a

  12. Cytotoxicity of aluminium oxide nanoparticles towards fresh water algal isolate at low exposure concentrations.

    Science.gov (United States)

    Pakrashi, Sunandan; Dalai, Swayamprava; T C, Prathna; Trivedi, Shruti; Myneni, Radhika; Raichur, Ashok M; Chandrasekaran, N; Mukherjee, Amitava

    2013-05-15

    The growing commercial applications had brought aluminium oxide nanoparticles under toxicologists' purview. In the present study, the cytotoxicity of two different sized aluminium oxide nanoparticles (ANP(1), mean hydrodynamic diameter 82.6±22nm and ANP(2), mean hydrodynamic diameter 246.9±39nm) towards freshwater algal isolate Chlorella ellipsoids at low exposure levels (≤1μg/mL) using sterile lake water as the test medium was assessed. The dissolution of alumina nanoparticles and consequent contribution towards toxicity remained largely unexplored owing to its presumed insoluble nature. Herein, the leached Al(3+) ion mediated toxicity has been studied along with direct particulate toxicity to bring out the dynamics of toxicity through colloidal stability, biochemical, spectroscopic and microscopic analyses. The mean hydrodynamic diameter increased with time both for ANP(1) [82.6±22nm (0h) to 246.3±59nm (24h), to 1204±140nm (72h)] and ANP(2) [246.9±39nm (0h) to 368.28±48nm (24h), to 1225.96±186nm (72h)] signifying decreased relative abundance of submicron sized particles (<1000nm). The detailed cytotoxicity assays showed a significant reduction in the viability dependent on dose and exposure. A significant increase in ROS and LDH levels were noted for both ANPs at 1μg/mL concentration. The zeta potential and FT-IR analyses suggested surface chemical interaction between nanoparticles and algal cells. The substantial morphological changes and cell wall damage were confirmed through microscopic analyses (SEM, TEM, and CLSM). At 72h, significant Al(3+) ion release in the test medium [0.092μg/mL for ANP(1), and 0.19μg/mL for ANP(2)] was noted, and the resulting suspension containing leached ions caused significant cytotoxicity, revealing a substantial ionic contribution. This study indicates that both the nano-size and ionic dissolution play a significant role in the cytotoxicity of ANPs towards freshwater algae, and the exposure period largely determines

  13. The ecology of acidification and recovery: changes in herbivore-algal food web linkages across a stream pH gradient

    Energy Technology Data Exchange (ETDEWEB)

    Ledger, M.E. [Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom)]. E-mail: m.e.ledger@bham.ac.uk; Hildrew, A.G. [Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom)

    2005-09-15

    We examined the effects of acidification on herbivore-algal food web linkages in headwater streams. We determined the structure and abundance of consumer and benthic algal assemblages, and gauged herbivory, in 10 streams along a pH gradient (mean annual pH 4.6-6.4). Biofilm taxonomic composition changed with pH but total abundance did not vary systematically across the gradient. Mayflies and chironomids dominated under circumneutral conditions but declined with increasing acidity and their consumption of algae was strongly reduced. Contrary to expectations, several putative shredder species consumed algae, maintaining the herbivore-algal linkage where specialist grazers could not persist. These shifts in functioning could render the communities of acidified streams resistant to reinvasion when acidity ameliorates and water chemistry is restored to a pre-acidification condition. This hypothesis is discussed in the light of recent trends in the chemistry and biology of the UK Acid Waters Monitoring Network sites. - Generalist invertebrates maintain algae-herbivore interactions in acid streams.

  14. How hydrodynamics control algal blooms in the Ythan estuary, Scotland

    Science.gov (United States)

    Champangern, Khruewan; Hoey, Trevor; Thomas, Rhian

    2016-04-01

    The Ythan estuary, northeast Scotland, was designated in 2000 as a Nitrate Vulnerable Zone (NVZ) under the European Commission (EC) Nitrates Directive. Much of the catchment is intensively farmed and water quality has been adversely affected by nutrients from agricultural fertilizers. As a result, algal mats develop annually on tidal flats where sediment from upstream and from the adjacent dune systems is deposited. Understanding the patterns of water (river and ocean) circulation in the estuary as well as understanding how nutrients and sediments are transported in the estuary is crucial for understanding the role of several factors (elevation; sediment characteristics; nutrient flux) control the locations and scale of annual algal blooms. In order to understand those controls, study of interactions between hydrodynamic factors and water quality, in particular chlorophyll levels, at different time scales has been carried out. The results from the study reveal complex seasonal and event-scale relationships of river flow with the amount of chlorophyll, which provide an initial comprehension of controls over the concentrations of chlorophyll in the estuary. The concentration of chlorophyll changes, whether increasing or decreasing, with regards to changes in river flow. During high flow events, high amounts of chlorophyll are found when the tide is low. During low flow events, high amounts of chlorophyll are found at high tides. These phenomena reveal that both river flow and tidal cycle affect the amount of chlorophyll in the estuary. In addition, the Delft3d flow model, which has been extensively applied to many coastal and estuarine studies is used to simulate hydrodynamic patterns in the estuary during high flow and low flow events. The model is composed of 36,450 fine resolution grids and the upstream/ downstream boundary that represents water level is based on time-series data from river flow and tidal measurements. The bathymetry used for the model domain is

  15. 西藏拉萨市林周县虎头山水库春季藻类群落特征及其水体理化因子相关性分析%Analysis on the Correlation between the Characteristics of Algal Community and Water physicochemical factors in Linzhou Hutoushan reservoir in spring, Lhasa Tibet

    Institute of Scientific and Technical Information of China (English)

    巴桑; 刘伟伟; 赵攀登; 葛艳飞; 强巴塔庆

    2015-01-01

    为研究西藏拉萨市林周县虎头山水库春季藻类群落结构特征与水体环境因子间的关系,于2015年5月在虎头山水库设置了六个采样点,用活体观察法鉴定藻类物种,并用直接计数法统计藻类的数量.共鉴定出183种藻类,隶属于8门10纲22目30科51属,其中双壳缝目49种,占26.78%,为优势类群;无壳缝目25种,占13.66%,为次优势类群;气球藻目1种,占0.55%,为罕见类群,其余为常见类群.优势种有简单舟形藻(Navicula simplex)、针状蓝纤维藻(Dactylococcopsis acicularis)、尖针杆藻(Synedra acus)、放射舟形藻(Navicula radiosa)、小球藻(Chlorella vulgaris)、颤丝藻(Ulotrix osillarina).结果表明,该水库藻类物种丰富,群落结构复杂,各采样点的藻类,相似度低,具有局部地域性和小环境的特征.藻类群落结构参数与水体理化因子间的相关性表明,水体理化因子与藻类群落组成无相关性.%This study was carried out in order to examining characteristics of algae community structure and rela-tionship between that and water physicochemical factors in Hutoushan reservoir. All together 6 samples were col-lected in the reservoir in May 2015. In vivo microscopic observation was applied for algae species identification. The number of algae species was counted by direct counting method. A total of 183 species were indentified, which belonging to 51 genera, 30 families, 22 orders, 10 classes and 8 phyla. There were 49 species of Biraphidi-nales, accounting for 26.78%of the total, as the dominant groups and, 25 species of Araphidiales, accounting for 13.66%of the total, as the secondary dominant groups. There were 1 species of Botrydiales Ettle, accounting on-ly for 0.55%of the total, it was the rare group. The rest species were common groups. The results showed that the algae species in the reservoir was highly rich and the community structure was complex, however, with signifi-cant differences between individual sampling

  16. [Growing old as a woman].

    Science.gov (United States)

    Boyer-Weinmann, Martine

    2014-01-01

    Growing old as a woman. Since Diderot, a classic writer, and his friend Sophie Volland with whom he corresponded, debated the difference between the "handsome old man" and "beautiful old age", or a hypothetical "beautiful old woman", the representations of growing old have changed, to the benefit of women. Has the considerable contribution of female writers to the debate played a role? In what ways does literature, through its figurations of the ages of life, provide a valuable perspective of the contemporary mutations of the view of old age?

  17. Eco-evolutionary feedbacks between private and public goods: evidence from toxic algal blooms.

    Science.gov (United States)

    Driscoll, William W; Hackett, Jeremiah D; Ferrière, Régis

    2016-01-01

    The importance of 'eco-evolutionary feedbacks' in natural systems is currently unclear. Here, we advance a general hypothesis for a particular class of eco-evolutionary feedbacks with potentially large, long-lasting impacts in complex ecosystems. These eco-evolutionary feedbacks involve traits that mediate important interactions with abiotic and biotic features of the environment and a self-driven reversal of selection as the ecological impact of the trait varies between private (small scale) and public (large scale). Toxic algal blooms may involve such eco-evolutionary feedbacks due to the emergence of public goods. We review evidence that toxin production by microalgae may yield 'privatised' benefits for individual cells or colonies under pre- and early-bloom conditions; however, the large-scale, ecosystem-level effects of toxicity associated with bloom states yield benefits that are necessarily 'public'. Theory predicts that the replacement of private with public goods may reverse selection for toxicity in the absence of higher level selection. Indeed, blooms often harbor significant genetic and functional diversity: bloom populations may undergo genetic differentiation over a scale of days, and even genetically similar lineages may vary widely in toxic potential. Intriguingly, these observations find parallels in terrestrial communities, suggesting that toxic blooms may serve as useful models for eco-evolutionary dynamics in nature. Eco-evolutionary feedbacks involving the emergence of a public good may shed new light on the potential for interactions between ecology and evolution to influence the structure and function of entire ecosystems.

  18. Remote Sensing as a Tool to Track Algal Blooms in the Great Salt Lake, Utah, USA

    Science.gov (United States)

    Bradt, S. R.; Wurtsbaugh, W. A.; Naftz, D.; Moore, T.; Haney, J.

    2006-12-01

    The Great Salt Lake is a large hypersaline, terminal water body in northern Utah, USA. The lake has both a significant economic importance to the local community as a source of brine shrimp and mineral resources, as well as, an ecological importance to large numbers of migratory waterfowl. Due to nutrient input from sewage treatment plants, sections of the Great Salt Lake are subjected to highly eutrophic conditions. One of the main tributaries, Farmington Bay, experiences massive blooms of cyanobacteria which can reach concentrations in excess of 300 mg l-1 in the bay. Effects of these blooms can be observed stretching into the rest of the lake. The detrimental outcomes of the blooms include unsightly scums, foul odor and the danger of cyanobacterial toxins. While the blooms have an obvious effect on Farmington Bay, it is quite possible that the cyanobacteria impact a much wider area of the lake as currents move eutrophic water masses. Of particular interest is the reaction of brine shrimp to the plumes of cyanobacteria-rich water leaving Farmington Bay. We are employing remote sensing as a tool to map the distribution of algae throughout the lake and produce lake-wide maps of water quality on a regular basis. On-lake reflectance measurements have been coupled with MODIS satellite imagery to produce a time series of maps illustrating changes in algal distribution. The successes and shortcomings of our remote sensing technique will be a central topic of this presentation.

  19. Energy-efficient photobioreactor configuration for algal biomass production.

    Science.gov (United States)

    Pegallapati, Ambica Koushik; Arudchelvam, Yalini; Nirmalakhandan, Nagamany

    2012-12-01

    An internally illuminated photobioreactor (IIPBR) design is proposed for energy-efficient biomass production. Theoretical rationale of the IIPBR design and its advantages over the traditional bubble column photobioreactors (PBRs) are presented, followed by experimental results from prototype scale cultivation of freshwater and marine algal strains in an 18L IIPBR. Based on theoretical considerations, the proposed IIPBR design has the potential to support 160% higher biomass density and higher biomass productivity per unit energy input, B/E, than a bubble column PBR of equal incident area per unit culture volume. Experimental B/E values recorded in this study with fresh water algae and marine algae (1.42 and 0.37 gW(-1)d(-1), respectively) are at least twice as those reported in the literature for comparable species cultivated in bubble column and airlift PBRs.

  20. Discussion about mechanism of harmful algal blooms breakout

    Institute of Scientific and Technical Information of China (English)

    BU Xianwei; XU Weiyi; ZHU Dedi; CHEN Gengxin

    2005-01-01

    HAB (harmful algal bloom) is a serious marine ecological disaster. Up to now there is no definite conclusion about its mechanism of occurrence.The observation results show that the HAB breakout in the Xiangshan Bay was mainly caused by physical convergence ca pacity,and the breakout process had no direct relation to eutrophication. As a new idea it is thought that the process of the HAB break out is mainly a physical convergence or accumulation process in some areas. A hypothesis about dynamic mechanism of the HAB ap pearing in the area off the Changjiang Estuary is put forward according to hydrology and topography and the past work, and a breakthrough is expected to be made for doing further research.

  1. Coral host cells acidify symbiotic algal microenvironment to promote photosynthesis.

    Science.gov (United States)

    Barott, Katie L; Venn, Alexander A; Perez, Sidney O; Tambutté, Sylvie; Tresguerres, Martin

    2015-01-13

    Symbiotic dinoflagellate algae residing inside coral tissues supply the host with the majority of their energy requirements through the translocation of photosynthetically fixed carbon. The algae, in turn, rely on the host for the supply of inorganic carbon. Carbon must be concentrated as CO2 in order for photosynthesis to proceed, and here we show that the coral host plays an active role in this process. The host-derived symbiosome membrane surrounding the algae abundantly expresses vacuolar H(+)-ATPase (VHA), which acidifies the symbiosome space down to pH ∼ 4. Inhibition of VHA results in a significant decrease in average H(+) activity in the symbiosome of up to 75% and a significant reduction in O2 production rate, a measure of photosynthetic activity. These results suggest that host VHA is part of a previously unidentified carbon concentrating mechanism for algal photosynthesis and provide mechanistic evidence that coral host cells can actively modulate the physiology of their symbionts.

  2. Arrest of cytoplasmic streaming induces algal proliferation in green paramecia.

    Directory of Open Access Journals (Sweden)

    Toshiyuki Takahashi

    Full Text Available A green ciliate Paramecium bursaria, bearing several hundreds of endosymbiotic algae, demonstrates rotational microtubule-based cytoplasmic streaming, in which cytoplasmic granules and endosymbiotic algae flow in a constant direction. However, its physiological significance is still unknown. We investigated physiological roles of cytoplasmic streaming in P. bursaria through host cell cycle using video-microscopy. Here, we found that cytoplasmic streaming was arrested in dividing green paramecia and the endosymbiotic algae proliferated only during the arrest of cytoplasmic streaming. Interestingly, arrest of cytoplasmic streaming with pressure or a microtubule drug also induced proliferation of endosymbiotic algae independently of host cell cycle. Thus, cytoplasmic streaming may control the algal proliferation in P. bursaria. Furthermore, confocal microscopic observation revealed that a division septum was formed in the constricted area of a dividing paramecium, producing arrest of cytoplasmic streaming. This is a first report to suggest that cytoplasmic streaming controls proliferation of eukaryotic cells.

  3. Enzyme-like activities of algal polysaccharide - cerium complexes

    Science.gov (United States)

    Wang, Dongfeng; Sun, Jipeng; Du, Dehong; Ye, Shen; Wang, Changhong; Zhou, Xiaoling; Xue, Changhu

    2005-01-01

    Water-soluble algal polysaccharides (APS) (alginic acid, fucoidan and laminaran) possess many pharmacological activities. The results of this study showed that the APS-Ce4+ complexes have some enzyme-like activities. Fucoidan and its complex with Ce4+ have activities similar to those of SOD. The activities of laminaran, alginic acid and their complexes are not measurable. The APS do not show measurable activities in the digestion of plasmid DNA. In contrast, the APS - Ce4+ complexes show these measurable activities under the comparable condition when APS bind Ce4+ and form homogenous solutions. The laminaran - Ce4+ complex shows the most obvious activity in the digestion of plasmid DNA, pNPP and chloropy-rifos under neutral conditions.

  4. Heat stress in growing pigs

    NARCIS (Netherlands)

    Huynh Thi Thanh Thuy,

    2005-01-01

    Compared to other species of farm animals, pigs are more sensitive to high environmental temperatures, because they cannot sweat and do not pant so well. Furthermore, fast-growing lean pigs generate more heat than their congeners living in the wild. This, in combination with confined housing, makes

  5. Exploring Classroom Hydroponics. Growing Ideas.

    Science.gov (United States)

    National Gardening Association, Burlington, VT.

    Growing Ideas, the National Gardening Association's series for elementary, middle, and junior high school educators, helps teachers engage students in using plants and gardens as contexts for developing a deeper, richer understanding of the world around them. This volume's focus is on hydroponics. It presents basic hydroponics information along…

  6. [Rapid growing liposarcoma in retroperitoneum

    DEFF Research Database (Denmark)

    Engel, L.E.; Mynster, T.

    2008-01-01

    A 36-year-old male was admitted with a giant abdominal tumour and dyspnoea from thoracic displacement. Symptoms were one year of haemorrhoids, but complaints of growing abdomen presented only for 10 weeks. Ultrasound could not differentiate tumour from the liver, but MR scan could. A 24.2 kg...

  7. Organization of growing random networks

    Energy Technology Data Exchange (ETDEWEB)

    Krapivsky, P. L.; Redner, S.

    2001-06-01

    The organizational development of growing random networks is investigated. These growing networks are built by adding nodes successively, and linking each to an earlier node of degree k with an attachment probability A{sub k}. When A{sub k} grows more slowly than linearly with k, the number of nodes with k links, N{sub k}(t), decays faster than a power law in k, while for A{sub k} growing faster than linearly in k, a single node emerges which connects to nearly all other nodes. When A{sub k} is asymptotically linear, N{sub k}(t){similar_to}tk{sup {minus}{nu}}, with {nu} dependent on details of the attachment probability, but in the range 2{lt}{nu}{lt}{infinity}. The combined age and degree distribution of nodes shows that old nodes typically have a large degree. There is also a significant correlation in the degrees of neighboring nodes, so that nodes of similar degree are more likely to be connected. The size distributions of the in and out components of the network with respect to a given node{emdash}namely, its {open_quotes}descendants{close_quotes} and {open_quotes}ancestors{close_quotes}{emdash}are also determined. The in component exhibits a robust s{sup {minus}2} power-law tail, where s is the component size. The out component has a typical size of order lnt, and it provides basic insights into the genealogy of the network.

  8. Growing an Emerging Research University

    Science.gov (United States)

    Birx, Donald L.; Anderson-Fletcher, Elizabeth; Whitney, Elizabeth

    2013-01-01

    The emerging research college or university is one of the most formidable resources a region has to reinvent and grow its economy. This paper is the first of two that outlines a process of building research universities that enhance regional technology development and facilitate flexible networks of collaboration and resource sharing. Although the…

  9. The growing VAO flavoprotein family

    NARCIS (Netherlands)

    Leferink, Nicole G. H.; Heuts, Dominic P. H. M.; Fraaije, Marco W.; van Berkel, Willem J. H.

    2008-01-01

    The VAO flavoprotein family is a rapidly growing family of oxidoreductases that favor the covalent binding of the FAD cofactor. In this review we report on the catalytic properties of some newly discovered VAO family members and their mode of flavin binding. Covalent binding of the flavin is a self-

  10. Growing Patterns: Seeing beyond Counting

    Science.gov (United States)

    Markworth, Kimberly A.

    2012-01-01

    Over the past two decades, mathematical patterns have been acknowledged as important early components of children's development of algebraic reasoning (NCTM 2000). In particular, growing patterns have attracted significant attention as a context that helps students develop an understanding of functional relationships (Lee and Freiman 2006; Moss et…

  11. Growing Wild and Being Managed

    DEFF Research Database (Denmark)

    Andreasen, Lars Birch

    2012-01-01

    This paper discusses the use of mobile communication and the spread of internet cafés, which are both growing rapidly in today’s Vietnam. Daily life in Vietnam is a complex mix of modern and traditional, public and private; the use of mobile phones, internet, and other communication possibilities...

  12. Distribution of heavy metals from flue gas in algal bioreactor

    Science.gov (United States)

    Napan, Katerine

    Flue gas from coal-fired power plants is a major source of CO2 to the atmosphere. Microalgae can use this enriched form of CO2 as carbon source and in turn the biomass can be used to produce food, feed, fertilizer and biofuels. However, along with CO2, coal-based flue gas will inevitably introduce heavy metals, which have a high affinity to bind algal cells, could be toxic to the organisms and if transferred to the products could limit their uses. This study seeks to address the distribution and impact of heavy metals present in flue gas on microalgae production systems. To comprehend its effects, algae Scenedesmus obliquus was grown in batch reactors in a multimetal system. Ten heavy metals (Cu, Co, Zn, Pb, As, Se, Cr, Hg, Ni and Cd) were selected and were evaluated at four concentrations (1X, 2X, 5X and 10X). Results show that most heavy metals accumulated mainly in biomass and were found in very low concentrations in media. Hg was shown to be lost from the culture, with low amounts present in the biomass. An upper limit for As uptake was observed, suggesting its likelihood to build-up in the system during medium recycle. The As limited bioaccumulation was overcome by addition of sulfur to the algal medium. Heavy metal at 2X, 5X and 10X inhibited both growth and lipid production, while at the reference concentration both biomass and lipids yields were increased. Heavy metal concentrations in the medium and biomass were time dependent, and at the end of the cultivation most heavy metals in the supernatant solution complied with the recommendations for irrigation water, while biomass was below limits for cattle and poultry feed, fertilizer, plastic and paper. This research shows that bioremediation of CO2 and heavy metals in combination with energy production can be integrated, which is an environmentally friendly form of biotechnology.

  13. In situ oxygen dynamics in coral-algal interactions.

    Directory of Open Access Journals (Sweden)

    Daniel Wangpraseurt

    Full Text Available BACKGROUND: Coral reefs degrade globally at an alarming rate, with benthic algae often replacing corals. However, the extent to which benthic algae contribute to coral mortality, and the potential mechanisms involved, remain disputed. Recent laboratory studies suggested that algae kill corals by inducing hypoxia on the coral surface, through stimulated microbial respiration. METHODS/FINDINGS: We examined the main premise of this hypothesis by measuring in situ oxygen microenvironments at the contact interface between the massive coral Porites spp. and turf algae, and between Porites spp. and crustose coralline algae (CCA. Oxygen levels at the interface were similar to healthy coral tissue and ranged between 300-400 µM during the day. At night, the interface was hypoxic (~70 µM in coral-turf interactions and close to anoxic (~2 µM in coral-CCA interactions, but these values were not significantly different from healthy tissue. The diffusive boundary layer (DBL was about three times thicker at the interface than above healthy tissue, due to a depression in the local topography. A numerical model, developed to analyze the oxygen profiles above the irregular interface, revealed strongly reduced net photosynthesis and dark respiration rates at the coral-algal interface compared to unaffected tissue during the day and at night, respectively. CONCLUSIONS/SIGNIFICANCE: Our results showed that hypoxia was not a consistent feature in the microenvironment of the coral-algal interface under in situ conditions. Therefore, hypoxia alone is unlikely to be the cause of coral mortality. Due to the modified topography, the interaction zone is distinguished by a thicker diffusive boundary layer, which limits the local metabolic activity and likely promotes accumulation of potentially harmful metabolic products (e.g., allelochemicals and protons. Our study highlights the importance of mass transfer phenomena and the need for direct in situ measurements of

  14. Trans-generational specificity within a cnidarian-algal symbiosis

    Science.gov (United States)

    Poland, D. M.; Coffroth, M. A.

    2017-03-01

    Ocean warming and other anthropogenic stresses threaten the symbiosis between tropical reef cnidarians and their dinoflagellate endosymbionts ( Symbiodinium). Offspring of many cnidarians acquire their algal symbionts from the environment, and such flexibility could allow corals to respond to environmental changes between generations. To investigate the effect of both habitat and host genotype on symbiont acquisition, we transplanted aposymbiotic offspring of the common Caribbean octocoral Briareum asbestinum to (1) an environmentally different habitat that lacked B. asbestinum and (2) an environmentally similar habitat where local adults harbored Symbiodinium phylotypes that differed from parental colonies. Symbiont acquisition and establishment of symbioses over time was followed using a within-clade DNA marker (23S chloroplast rDNA) and a within-phylotype marker (unique alleles at a single microsatellite locus). Early in the symbiosis, B. asbestinum juveniles harbored multiple symbiont phylotypes, regardless of source (parent or site). However, with time ( 4 yr), offspring established symbioses with the symbiont phylotype dominant in the parental colonies, regardless of transplant location. Within-phylotype analyses of the symbionts revealed a similar pattern, with offspring acquiring the allelic variant common in symbionts in the parental population regardless of the environment in which the offspring was reared. These data suggest that in this host species, host-symbiont specificity is a genetically determined trait. If this level of specificity is widespread among other symbiotic cnidarians, many cnidarian-algal symbioses may not be able to respond to rapid, climate change-associated environmental changes by means of between-generation switching of symbionts.

  15. Offshore Membrane Enclosures for Growing Algae (OMEGA: A System for Biofuel Production, Wastewater Treatment, and CO2 Sequestration

    Science.gov (United States)

    Trent, Jonathan; Embaye, Tsegereda; Buckwalter, Patrick; Richardson, Tra-My; Kagawa, Hiromi; Reinsch, Sigrid; Martis, Mary

    2010-01-01

    We are developing Offshore Membrane Enclosures for Growing Algae (OMEGA). OMEGAs are closed photo-bioreactors constructed of flexible, inexpensive, and durable plastic with small sections of semi-permeable membranes for gas exchange and forward osmosis (FO). Each OMEGA modules is filled with municipal wastewater and provided with CO2 from coastal CO2 sources. The OMEGA modules float just below the surface, and the surrounding seawater provides structural support, temperature control, and mixing for the freshwater algae cultures inside. The salinit7 gradient from inside to outside drives forward osmosis through the patches of FO membranes. This concentrates nutrients in the wastewater, which enhances algal growth, and slowly dewaters the algae, which facilitates harvesting. Thy concentrated algal biomass is harvested for producing biofuels and fertilizer. OMEGA system cleans the wastewater released into the surrounding coastal waters and functions as a carbon sequestration system.

  16. Offshore Membrane Enclosure for Growing Algai (Omega) System for Biofuel Production, Wastewater Treatment, and CO2 Sequestration

    Science.gov (United States)

    Trent, Jonathan; Embaye, Tsegereda; Buckwalter, Patrick; Richardson, Tra-My; Kagawa, Hiromi; Reinsch, Sigrid

    2010-01-01

    We are developing Offshore Membrane Enclosures for Growing Algae (OMEGA). OMEGAs are closed photo-bioreactors constructed of flexible, inexpensive, and durable plastic with small sections of semi-permeable membranes for gas exchange and forward osmosis (FO). Each OMEGA modules is filled with municipal wastewater and provided with CO2 from coastal CO2 sources. The OMEGA modules float just below the surface, and the surrounding seawater provides structural support, temperature control, and mixing for the freshwater algae cultures inside. The salinity gradient from inside to outside drives forward osmosis through the patches of FO membranes. This concentrates nutrients in the wastewater, which enhances algal growth, and slowly dewaters the algae, which facilitates harvesting. The concentrated algal biomass is harvested for producing biofuels and fertilizer. OMEGA system cleans the wastewater released into the surrounding coastal waters and functions as a carbon sequestration system.

  17. Interactions between algal-bacterial populations and trace metals in fjord surface waters during a nutrient stimulated summer bloom

    DEFF Research Database (Denmark)

    Muller, F.; Larsen, A.; Stedmon, C.;

    2005-01-01

    this period, the weaker Cu-binding ligands appeared to have the same source or production process as the proteinlike fluorophores detected in these coastal waters. Zinc speciation was controlled by complexation with a single class of organic ligands that appeared to be released inadvertently upon the death......We examined how variations in algal-bacterial community structure relate to Cu, Zn, and Mn speciation during a diatom-rich bloom that was induced by daily additions of inorganic macronutrients to fjord waters in August 2002. The experiments were carried out in 11-m3 floating mesocosm bags deployed...... and/or grazing of phytoplankton. Labile manganese fluctuations were inversely synchronized with the abundance of heterotrophic bacteria until the coastal waters experienced a massive rain event on day 17 of the experiment. The rainfall, which was a source of nitrogen and micronutrients, appeared...

  18. Algal Pretreatment Improves Biofuels Yield and Value; Highlights in Science, NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-05-15

    One of the major challenges associated with algal biofuels production in a biorefinery-type setting is improving biomass utilization in its entirety, increasing the process energetic yields and providing economically viable and scalable co-product concepts. We demonstrate the effectiveness of a novel, integrated technology based on moderate temperatures and low pH to convert the carbohydrates in wet algal biomass to soluble sugars for fermentation, while making lipids more accessible for downstream extraction and leaving a protein-enriched fraction behind. This research has been highlighted in the Green Chemistry journal article mentioned above and a milestone report, and is based on the work the researchers are doing for the AOP projects Algal Biomass Conversion and Algal Biofuels Techno-economic Analysis. That work has demonstrated an advanced process for algal biofuel production that captures the value of both the algal lipids and carbohydrates for conversion to biofuels.  With this process, as much as 150 GGE/ton of biomass can be produced, 2-3X more than can be produced by terrestrial feedstocks.  This can also reduce the cost of biofuel production by as much as 40%. This also represents the first ever design case for the algal lipid upgrading pathway.

  19. Pyrolysis Strategies for Effective Utilization of Lignocellulosic and Algal Biomass

    Science.gov (United States)

    Maddi, Balakrishna

    Pyrolysis is a processing technique involving thermal degradation of biomass in the absence of oxygen. The bio-oils obtained following the condensation of the pyrolysis vapors form a convenient starting point for valorizing the major components of lignocellulosic as well as algal biomass feed stocks for the production of fuels and value-added chemicals. Pyrolysis can be implemented on whole biomass or on residues left behind following standard fractionation methods. Microalgae and oil seeds predominantly consist of protein, carbohydrate and triglycerides, whereas lignocellulose is composed of carbohydrates (cellulose and hemicellulose) and lignin. The differences in the major components of these two types of biomass will necessitate different pyrolysis strategies to derive the optimal benefits from the resulting bio-oils. In this thesis, novel pyrolysis strategies were developed that enable efficient utilization of the bio-oils (and/or their vapors) from lignocellulose, algae, as well as oil seed feed stocks. With lignocellulosic feed stocks, pyrolysis of whole biomass as well as the lignin residue left behind following well-established pretreatment and saccharification (i.e., depolymerization of cellulose and hemicellulose to their monomeric-sugars) of the biomass was studied with and without catalysts. Following this, pyrolysis of (lipid-deficient) algae and lignocellulosic feed stocks, under similar reactor conditions, was performed for comparison of product (bio-oil, gas and bio-char) yields and composition. In spite of major differences in component bio-polymers, feedstock properties relevant to thermo-chemical conversions, such as overall C, H and O-content, C/O and H/C molar ratio as well as calorific values, were found to be similar for algae and lignocellulosic material. Bio-oil yields from algae and some lignocellulosic materials were similar; however, algal bio-oils were compositionally different and contained several N-compounds (most likely from

  20. Microbial community response during the iron fertilization experiment LOHAFEX

    Digital Repository Service at National Institute of Oceanography (India)

    Thiele, S.; Fuchs, B.M.; Ramaiah, N.; Amanna, R.

    was enhanced within the fertilized area, a succession - like response of the microbial community upon the algal bloom was averted by highly effective grazing. Only small-celled members like the SAR11 and SAR86 clades could possibly escape the grazing pressure...

  1. Clostridium botulinum type E occurs and grows in the alga Cladophora glomerata

    Science.gov (United States)

    Byappanahalli, M.N.; Whitman, R.L.

    2009-01-01

    In recent years, massive avian die-offs from Clostridium botulinum type E infection have occurred in the Sleeping Bear Dunes National Lakeshore (SLBE) area of Lake Michigan. These outbreaks have been coincidental with massive blooms of the green algae Cladophora, mostly Cladophora glomerata. We tested the hypothesis that Clostridium botulinum type E can grow under suitable conditions in these algal mats. In a lab mesocosm study, Cladophora from four outbreak-impacted beaches from SLBE were compared with four unimpacted beaches in the Milwaukee–Racine area for bontE gene of Clostridium botulinum. Frequency of the bontE gene was higher after incubation (25 °C for up to 6 weeks) of Cladophora from impacted vs. the unimpacted area. Since no type E gene was detected initially in Cladophora from any of the eight locations, we infer that the increased occurrence of type E gene arose from spore germination or vegetative Clostridium growth within the existing algal mats of SLBE. Moreover, we found that the congener Clostridium perfringens readily grows in mesocosms containing Cladophora.

  2. Growing Research Practices: Expanding Our Communities and Our Conversations

    Science.gov (United States)

    Maloch, Beth

    2009-01-01

    Beth Maloch reflects on her Alan Purves Award-winning article, which was chosen because of its demonstration of the ability of one teacher to make a difference in young students' use of informational texts to develop complex, literate lives. (Contains 1 note.)

  3. TIGER capacity building facility: growing from projects to professional community

    NARCIS (Netherlands)

    Vekerdy, Z.; Su, B.; Menenti, M.; Swinnen, E.; Painho, M.; Fernandez, D.

    2010-01-01

    Water security has become one of the most important challenges in the sustainable development of Africa, but only limited reliable information is available on the use and availability of water to support adequate planning and management of water resources. Data acquired from space can contribute to

  4. Community Gardens to grow in memory of students and faculty

    OpenAIRE

    Felker, Susan B.

    2007-01-01

    Virginia Tech students will be planting maroon and orange Hokie flower gardens throughout the region on Saturday, April 28, as a living memorial to Virginia Tech's students and faculty whose lives were lost on April 16.

  5. Polar coralline algal CaCO3-production rates correspond to intensity and duration of the solar radiation

    Science.gov (United States)

    Teichert, S.; Freiwald, A.

    2014-02-01

    In this study we present a comparative quantification of CaCO3 production rates by rhodolith-forming coralline red algal communities situated in high polar latitudes and assess which environmental parameters control these production rates. The present rhodoliths act as ecosystem engineers, and their carbonate skeletons provide an important ecological niche to a variety of benthic organisms. The settings are distributed along the coasts of the Svalbard archipelago, being Floskjeret (78°18' N) in Isfjorden, Krossfjorden (79°08' N) at the eastern coast of Haakon VII Land, Mosselbukta (79°53' N) at the eastern coast of Mosselhalvøya, and Nordkappbukta (80°31' N) at the northern coast of Nordaustlandet. All sites feature Arctic climate and strong seasonality. The algal CaCO3 production rates were calculated from fuchsine-stained, presumably annual growth increments exhibited by the rhodoliths and range from 100.9 g (CaCO3) m-2 yr-1 at Nordkappbukta to 200.3 g (CaCO3) m-2 yr-1 at Floskjeret. The rates correlate to various environmental parameters with geographical latitude being the most significant (negative correlation, R2 = 0.95, p = 0.0070), followed by the duration of the polar night (negative correlation, R2 = 0.93, p = 0.0220), the duration of the sea ice cover (negative correlation, R2 = 0.87, p = 0.0657), and the annual mean temperature (positive correlation, R2 = 0.48, p = 0.0301). This points out sufficient light incidence to be the main control of the growth of the examined coralline red algal rhodolith communities, while temperature is less important. Thus, the ongoing global change with its rising temperatures will most likely result in impaired conditions for the algae, because the concomitant increased global runoff will decrease water transparency and hence light incidence at the four offshore sites. Regarding the aforementioned role of the rhodoliths as ecosystem engineers, the impact on the associated organisms will presumably also be negative.

  6. Biological Soil Crusts from Coastal Dunes at the Baltic Sea: Cyanobacterial and Algal Biodiversity and Related Soil Properties.

    Science.gov (United States)

    Schulz, Karoline; Mikhailyuk, Tatiana; Dreßler, Mirko; Leinweber, Peter; Karsten, Ulf

    2016-01-01

    Biological soil crusts (BSCs) are known as "ecosystem-engineers" that have important, multifunctional ecological roles in primary production, in nutrient and hydrological cycles, and in stabilization of soils. These communities, however, are almost unstudied in coastal dunes of the temperate zone. Hence, for the first time, the biodiversity of cyanobacterial and algal dominated BSCs collected in five dunes from the southern Baltic Sea coast on the islands Rügen and Usedom (Germany) was investigated in connection with physicochemical soil parameters. The species composition of cyanobacteria and algae was identified with direct determination of crust subsamples, cultural methods, and diatom slides. To investigate the influence of soil properties on species composition, the texture, pH, electrical conductivity, carbonate content, total contents of carbon, nitrogen, phosphorus, and the bioavailable phosphorus-fraction (PO4 (3-)) were analyzed in adjacent BSC-free surface soils at each study site. The data indicate that BSCs in coastal dunes of the southern Baltic Sea represent an ecologically important vegetation form with a surprisingly high site-specific diversity of 19 cyanobacteria, 51 non-diatom algae, and 55 diatoms. All dominant species of the genera Coleofasciculus, Lyngbya, Microcoleus, Nostoc, Hydrocoryne, Leptolyngbya, Klebsormidium, and Lobochlamys are typical aero-terrestrial cyanobacteria and algae, respectively. This first study of coastal sand dunes in the Baltic region provides compelling evidence that here the BSCs were dominated by cyanobacteria, algae, or a mixture of both. Among the physicochemical soil properties, the total phosphorus content of the BSC-free sand was the only factor that significantly influenced the cyanobacterial and algal community structure of BSCs in coastal dunes.

  7. A rapidly growing lid lump

    Science.gov (United States)

    Koay, Su-Yin; Lee, Richard M H; Hugkulstone, Charles; Rodrigues, Ian Aureliano Stephen

    2014-01-01

    A 97-year-old woman presented with a 5-month history of a rapidly growing, painless, left upper eyelid lesion. Examination revealed a large vascularised, ulcerated nodule on the left upper lid, causing significant ptosis. Wide local excision of the lesion was performed and the wound was left to heal by secondary intention. Histology and immunohistochemistry of the lesion confirmed a diagnosis of Merkel cell carcinoma, a rare primary malignancy of the eyelid which has significant morbidity and mortality. Although uncommon, this diagnosis should always be considered in any patient with a rapidly growing lid lump. In view of the patient's age, known dementia and family wishes, the patient was managed conservatively, with no further investigations performed. She was due to be followed up in clinic on a regular basis, but has since died from other causes. PMID:25123568

  8. Growing Your Career through Volunteering and Leadership

    Science.gov (United States)

    O'Riordan, C. A.; Meth, C.

    2007-12-01

    From giving your first paper at a scientific meeting to chairing committees that make multi-million dollar decisions, scientific organizations provide critical opportunities for growing your career. Many organizations support student activities by providing travel grants and fellowships - an important first step towards joining the larger scientific community. Beyond these standard opportunities, organizations also provide opportunities for students interested in gaining leadership experience, a skill not typically acquired in graduate science programs. For example, the Consortium for Leadership's Schlanger Ocean Drilling Fellowship provides research funds to graduate students, but also introduces the fellows to the communication skills needed to become successful members of their scientific community. Beyond student opportunities, volunteering provides mid-career and established scientists further experience in leadership. Opportunities exist in advising government science policy, guiding large-scale research programs, organizing large scientific meetings, and serving on non-profit boards. The variety of volunteer and leadership opportunities that are available give scientists at all stages of their career a chance to expand and diversify their experience, leading to new successes.

  9. Heat stress in growing pigs

    OpenAIRE

    Huynh Thi Thanh Thuy

    2005-01-01

    Compared to other species of farm animals, pigs are more sensitive to high environmental temperatures, because they cannot sweat and do not pant so well. Furthermore, fast-growing lean pigs generate more heat than their congeners living in the wild. This, in combination with confined housing, makes it difficult for these pigs to regulate their heat balance. Heat stressed pigs have low performance, poor welfare, and, by pen fouling, they give higher emissions of odour and ammonia.Above certain...

  10. Carbonaceous Matter in Growing Nanoparticles

    Science.gov (United States)

    Johnston, M. V.; Stangl, C. M.; Horan, A. J.

    2015-12-01

    Atmospheric nanoparticles constitute the greatest portion of ambient aerosol loading by number. A major source of atmospheric nanoparticles is new particle formation (NPF), a gas to particle conversion process whereby clusters nucleate from gas phase precursors to form clusters on the order of one or a few nanometers and then grow rapidly to climatically relevant sizes. A substantial fraction of cloud condensation nuclei (CCN) are thought to arise from NPF. In order to better predict the frequency, growth rates, and climatic impacts of NPF, knowledge of the chemical mechanisms by which nucleated nanoparticles grow is needed. The two main contributors to particle growth are (neutralized) sulfate and carbonaceous matter. Particle growth by sulfuric acid condensation is generally well understood, though uncertainty remains about the extent of base neutralization and the relative roles of ammonia and amines. Much less is known about carbonaceous matter, and field measurements suggest that nitrogen-containing species are important. In this presentation, recent work by our group will be described that uses a combination of ambient measurements, laboratory experiments and computational work to study carbonaceous matter in growing nanoparticles. These studies span a range of particle sizes from the initial adsorption of molecules onto a nanometer-size ammonium bisulfate seed cluster to reactions in particles that are large enough to support condensed-phase chemistry.

  11. Proterozoic microfossils revealing the time of algal divergences

    Science.gov (United States)

    Moczydlowska-Vidal, Malgorzata

    2010-05-01

    Proterozoic microfossils revealing the time of algal divergences Małgorzata Moczydłowska-Vidal Uppsala University, Department of Earth Sciences, Palaeobiology, Villavägen 16, SE 752 36 Uppsala, Sweden (malgo.vidal@pal.uu.se) Morphological and reproductive features and cell wall ultrastructure and biochemistry of Proterozoic acritarchs are used to determine their affinity to modern algae. The first appearance datum of these microbiota is traced to infer a minimum age of the divergence of the algal classes to which they may belong. The chronological appearance of microfossils that represent phycoma-like and zygotic cysts and vegetative cells and/or aplanospores, respectively interpreted as prasinophyceaen and chlorophyceaen microalgae, is related to the Viridiplantae phylogeny. These divergence times differ from molecular clock estimates, and the palaeontological evidence suggests that they are older. The best examples of unicellular, organic-walled microfossils (acritarchs) from the Mesoproterozoic to Early Ordovician are reviewed to demonstrate features, which are indicative of their affinity to photosynthetic microalgae. The first indication that a microfossil may be algal is a decay- and acid-resistant cell wall, which reflects its biochemistry and ultrastructure, and probably indicates the ability to protect a resting/reproductive cyst. The biopolymers synthesized in the cell walls of algae and in land plants ("plant cells"), such as sporopollenin/algaenan, are diagnostic for photosynthetic taxa and were inherited from early unicellular ancestors. These preservable cell walls are resistant to acetolysis, hydrolysis and acids, and show diagnostic ultrastructures such as the trilaminar sheath structure (TLS). "Plant cell" walls differ in terms of chemical compounds, which give high preservation potential, from fungal and animal cell walls. Fungal and animal cells are fossilized only by syngenetic permineralization, whereas "plant cells" are fossilized as body

  12. Transport of Algal Cells in Hyporheic Sediments of the River Elbe (Germany)

    Science.gov (United States)

    Kloep, Frank; Röske, Isolde

    2004-01-01

    The advective transport of algal cells into the interstices of the hyporheic zone of the River Elbe was spatially and temporally heterogenous. Even deep sediment layers were reached by large phytoplankton species. Therefore, it is suggested that (i) the advective interstitial transport patterns vary between different algal sizes and morphotypes and (ii) sediment characteristics, expressed by the permeability coefficient kf of porous media, affect retention and retardation of surface water algae during subsurface transport. The transport behaviour of different green algae (Chlorella sp., Scenedesmus acuminatus, Desmodesmus communis, and Pediastrum duplex) and algal sized microspheres was tested in flow-through column experiments with hyporheic sediments. The algal cell transport was directly related to the permeability of the column sediments. (

  13. Measurement and Modeling of Algal Biokinetics in Highly EutrophicWaters

    Energy Technology Data Exchange (ETDEWEB)

    Stringfellow, William T.; Borglin, Sharon E.; Hanlon, Jeremy S.

    2006-04-04

    Excessive growth of suspended algae in eutrophic surface waters can contribute to the degradation of water quality. The objective of this study was to understand the fundamental processes limiting algal growth in highly nutrient-rich agricultural drainage water. Studies examining algal biokinetics (growth rates, yields, and decay) were conducted in a twenty-eight mile long, hydraulically simple, open channel. Algae biokinetics were found to follow a growth limited model,despite monitoring data demonstrating the presence of nutrients at concentrations far in excess of those expected to be limiting. A mechanistic algal biokinetic model was written to assist in data interpretation. Results from the mechanistic model suggested that at different times, soluble phosphate, minerals, and inorganic carbon could limit growth rates, but that growth yield was most likely limited by zooplankton grazing. The implication of these finding for control of algal growth are discussed.

  14. Process development for the production of bioethanol from waste algal biomass of Gracilaria verrucosa.

    Science.gov (United States)

    Shukla, Rishikesh; Kumar, Manoj; Chakraborty, Subhojit; Gupta, Rishi; Kumar, Savindra; Sahoo, Dinabandhu; Kuhad, Ramesh Chander

    2016-11-01

    The algal biomass of different species of Gracilaria were collected from coasts of Orissa and Tamil Nadu, India and characterized biochemically. Among various species, G. verrucosa was found to be better in terms of total carbohydrate content (56.65%) and hence selected for further studies. The agar was extracted from algal biomass and the residual pulp was enzymatically hydrolyzed. The optimization of algal pulp hydrolysis for various parameters revealed a maximum sugar release of 75.8mg/ml with 63% saccharification yield. The fermentation of enzymatic hydrolysate of algal pulp was optimized and 8% (v/v) inoculum size, 12h inoculum age, pH 5.0 were found to be optimum parameters for maximum ethanol concentration (27.2g/L) after 12h. The process of enzymatic hydrolysis and fermentation were successfully scaled up to 2L bioreactor scale.

  15. Non-conventional approaches to food processing in CELSS. I - Algal proteins: Characterization and process optimization

    Science.gov (United States)

    Nakhost, Z.; Karel, M.; Krukonis, V. J.

    1987-01-01

    Protein isolate obtained from green algae (Scenedesmus obliquus) cultivated under controlled conditions was characterized. Molecular weight determination of fractionated algal proteins using SDS-polyacrylamide gel electrophoresis revealed a wide spectrum of molecular weights ranging from 15,000 to 220,000. Isoelectric points of dissociated proteins were in the range of 3.95 to 6.20. Amino acid composition of protein isolate compared favorably with FAO standards. High content of essential amino acids leucine, valine, phenylalanine and lysine makes algal protein isolate a high quality component of CELSS diets. To optimize the removal of algal lipids and pigments supercritical carbon dioxide extraction (with and without ethanol as a co-solvent) was used. Addition of ethanol to supercritical CO2 resulted in more efficient removal of algal lipids and produced protein isolate with a good yield and protein recovery. The protein isolate extracted by the above mixture had an improved water solubility.

  16. Non-conventional approaches to food processing in CELSS, 1. Algal proteins: Characterization and process optimization

    Science.gov (United States)

    Nakhost, Z.; Karel, M.; Krukonis, V. J.

    1987-01-01

    Protein isolate obtained from green algae cultivated under controlled conditions was characterized. Molecular weight determination of fractionated algal proteins using SDS-polyacrylamide gel electrophoresis revealed a wide spectrum of molecular weights ranging from 15,000 to 220,000. Isoelectric points of dissociated proteins were in the range of 3.95 to 6.20. Amino acid composition of protein isolate compared favorably with FAO standards. High content of essential amino acids leucine, valine, phenylalanine and lysine make algal protein isolate a high quality component of closed ecological life support system diets. To optimize the removal of algal lipids and pigments supercritical carbon dioxide extraction (with and without ethanol as a co-solvent) was used. Addition of ethanol to supercritical carbon dioxide resulted in more efficient removal of algal lipids and produced protein isolate with a good yield and protein recovery. The protein isolate extracted by the above mixture had an improved water solubility.

  17. COMBUSTION ANALYSIS OF ALGAL OIL METHYL ESTER IN A DIRECT INJECTION COMPRESSION IGNITION ENGINE

    Directory of Open Access Journals (Sweden)

    HARIRAM V.

    2013-02-01

    Full Text Available Algal oil methyl ester was derived from microalgae (Spirulina sp. The microalga was cultivated in BG 11 media composition in a photobioreactor. Upon harvesting, the biomass was filtered and dried. The algal oil was obtained by a two step solvent extraction method using hexane and ether solvent. Cyclohexane was added to biomass to expel the remaining algal oil. By this method 92% of algal oil is obtained. Transesterification process was carried out to produce AOME by adding sodium hydroxide and methanol. The AOME was blended with straight diesel in 5%, 10% and 15% blend ratio. Combustion parameters were analyzed on a Kirloskar single cylinder direct injection compression ignition engine. The cylinder pressure characteristics, the rate of pressure rise, heat release analysis, performance and emissions were studied for straight diesel and the blends of AOME’s. AOME 15% blend exhibits significant variation in cylinder pressure and rate of heat release.

  18. Algal-bloom control by allelopathy of aquatic macrophytes——A review

    Institute of Scientific and Technical Information of China (English)

    Hongying HU; Yu HONG

    2008-01-01

    Algal-bloom control is an important issue for water environment protection as it induces several nega-tive impacts on the lives of aquatic organisms, aquacul-ture, landscaping, and human health. The development of an environment-friendly, cost-effective, and convenient alternative for controlling algal bloom has gained much concern. Using the allelopathy of aquatic macrophytes as a novel and safe method for algal-bloom control is a promising alternative. This paper reviews the develop-ment and potential application about allelopathy of aquatic plants on algae, including the allelopathic research history, the potential research problems, the research methodology, and the reported aquatic macro-phytes and their inhibitory allelochemicals. Potential modes of inhibition action of allelochemicals on algae, possible ways for application, and future development directions of research on algal-bloom control by aquatic macrophytes were also presented.

  19. Algal Biofuels Factsheet: Long-Term Energy Benefits Drive U.S. Research

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-03-04

    Algal biofuels are generating considerable interest around the world. In the United States, they represent promising pathways for helping to meet the biofuel production targets set by the Energy Independence and Security Act of 2007.

  20. Impact of harmful algal blooms on several Lake Erie drinking water treatment facilities; methodology considerations

    Science.gov (United States)

    The propagation of cyanbacterial cells and their toxins were investigated at seven drinking water treatment plants (DWTPs) on Lake Erie were investigated with regards to harmful algal bloom (HAB) toxin concentrations, water quality variations in treatment plant influents, and pr...

  1. Review of Water Consumption and Water Conservation Technologies in the Algal Biofuel Process.

    Science.gov (United States)

    Tu, Qingshi; Lu, Mingming; Thiansathit, Worrarat; Keener, Tim C

    2016-01-01

    Although water is one of the most critical factors affecting the sustainable development of algal biofuels, it is much less studied as compared to the extensive research on algal biofuel production technologies. This paper provides a review of the recent studies on water consumption of the algae biofuel process and presents the water conservation technologies applicable at different stages of the algal biofuel process. Open ponds tend to have much higher water consumption (216 to 2000 gal/gal) than photobioreactors (25 to 72 gal/gal). Algae growth accounts for the highest water consumption (165 to 2000 gal/gal) in the open pond system. Water consumption during harvesting, oil extraction, and biofuel conversion are much less compared with the growth stage. Potential water conservation opportunities include technology innovations and better management practices at different stages of algal biofuel production.

  2. Mass cultivation of various algal species and their evaluation as a potential candidate for lipid production.

    Science.gov (United States)

    Sharif, Nadia; Munir, Neelma; Saleem, Faiza; Aslam, Farheen; Naz, Shagufta

    2015-01-01

    Microalgae have been proposed as a promising source for biodiesel production. Focusing on algal strains for biodiesel production, efforts should be made to search new strains. Experiments were carried out to investigate the effects of growth parameters (nutrients, pH, light, aeration and temperature) and the oil percentage of eight algal strains (Chlorella sp., Cladophora sp., Hydrodictylium sp., Oedogonium sp., Oscillatoria sp., Spirogyra sp., Stigeocolonium sp., Ulothrix sp.). Results show that 6.5-7.5 is the optimum pH for the growth of all algal species. Temperature showed a greater variation (25°40°C). Ulothrix sp. gave more biomass productivity and is the most suitable strain for biodiesel production due to higher oil percentage (62%). Least biomass production was observed for Stigeocolonium sp. and least oil content was obtained from Hydrodictylium sp. It was observed that among these eight algal strains for biodiesel production, Ulothrix and Chlorella are the most promising algae species.

  3. Cyanobacterial-algal cenoses in ordinary chernozems under the impact of different phytoameliorants

    Science.gov (United States)

    Dubovik, I. E.; Suyundukov, Ya. T.; Khasanova, R. F.; Shalygina, R. R.

    2016-04-01

    General ecological and taxonomic characteristics of cyanobacterial-algal cenoses in ordinary chernozems under different ameliorative plants (phytoameliorants) were studied in the Trans-Ural region of the Republic of Bashkortostan. A comparative analysis of the taxa of studied cenoses in the soils under leguminous herbs and grasses was performed. The phytoameliorative effect of different herbs and their relationships with cyanobacterial-algal cenoses were examined. Overall, 134 cyanoprokaryotic and algal species belonging to 70 genera, 36 families, 15 orders, and 9 classes were identified. Cyanobacterial-algal cenoses included the divisions of Chlorophyta, Cyanoprokaryota, Xanthophyta, Bacillariophyta, and Euglenophyta. Representatives of Ch-, X-, CF-, and P-forms were the leading ecobiomorphs in the studied cenoses.

  4. Harmful algal blooms discovered during the Mote Monthly transect cruises, 1998 and 1999 (NODC Accession 0000532)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Harmful algal blooms of the toxic dinoflagellate, Karenia brevis, have caused massive fish kills in the Gulf of Mexico since the 1500's, with most occurrences on the...

  5. Determination of Total Carbohydrates in Algal Biomass: Laboratory Analytical Procedure (LAP)

    Energy Technology Data Exchange (ETDEWEB)

    Van Wychen, S.; Laurens, L. M. L.

    2013-12-01

    This procedure uses two-step sulfuric acid hydrolysis to hydrolyze the polymeric forms of carbohydrates in algal biomass into monomeric subunits. The monomers are then quantified by either HPLC or a suitable spectrophotometric method.

  6. Algal bloom response and risk management: On-site response tools.

    Science.gov (United States)

    Watson, Susan B; Zastepa, Arthur; Boyer, Gregory L; Matthews, Eric

    2017-02-13

    Harmful algal blooms caused by cyanobacteria can present a risk to the safety of drinking- and recreational waters and beachfronts through the production of toxins, particularly microcystin, which are highly resilient to degradation. These blooms are difficult to predict, vary in appearance and toxicity, and can show significant spatial heterogeneity: wind- and current-borne scums can produce an order of magnitude range in toxin levels along shorelines. The growing demand for reliable, cost-effective and rapid methods to detect toxins in bloom material and reduce the risk of public exposure cannot be met by most analytical lab turnaround times. Commercial microcystin test kits are now available, but few have been rigorously field-tested or incorporated into monitoring programmes. Working with a local health agency, we evaluated two kits with different operative ranges of detection, applied to samples covering a wide range of water quality, sample matrices, and bloom composition. We compared their performance against lab analyses using Enzyme-Linked Immunosorbent and Protein Phosphatase Inhibition assays. Both kits could resolve samples with high (<10 μg/L microcystin equivalents (MCequiv)) and low/no toxins, but failed to reliably detect toxin levels between 1 and 5 μg/L, at which threshold there were few false negatives (8%) but ∼ one third of the samples (32%) yielded false positives. We conclude that these kits are potentially useful for screening and informed risk management decisions e.g. on beach closures, but should be followed up with more rigorous tests where needed. We describe how, based on these results, the kits have been successfully incorporated into the routine municipal beach monitoring and advisory programme by the Hamilton Public Health Services (Ontario).

  7. Raman Microspectroscopy of Individual Algal Cells: Sensing Unsaturation of Storage Lipids in vivo

    Directory of Open Access Journals (Sweden)

    Ladislav Nedbal

    2010-09-01

    Full Text Available Algae are becoming a strategic source of fuels, food, feedstocks, and biologically active compounds. This potential has stimulated the development of innovative analytical methods focused on these microorganisms. Algal lipids are among the most promising potential products for fuels as well as for nutrition. The crucial parameter characterizing the algal lipids is the degree of unsaturation of the constituent fatty acids quantified by the iodine value. Here we demonstrate the capacity of the spatially resolved Raman microspectroscopy to determine the effective iodine value in lipid storage bodies of individual living algal cells. The Raman spectra were collected from three selected algal species immobilized in an agarose gel. Prior to immobilization, the algae were cultivated in the stationary phase inducing an overproduction of lipids. We employed the characteristic peaks in the Raman scattering spectra at 1,656 cm−1 (cis C=C stretching mode and 1,445 cm−1 (CH2 scissoring mode as the markers defining the ratio of unsaturated-to-saturated carbon-carbon bonds of the fatty acids in the algal lipids. These spectral features were first quantified for pure fatty acids of known iodine value. The resultant calibration curve was then used to calculate the effective iodine value of storage lipids in the living algal cells from their Raman spectra. We demonstrated that the iodine value differs significantly for the three studied algal species. Our spectroscopic estimations of the iodine value were validated using GC-MS measurements and an excellent agreement was found for the Trachydiscus minutus species. A good agreement was also found with the earlier published data on Botryococcus braunii. Thus, we propose that Raman microspectroscopy can become technique of choice in the rapidly expanding field of algal biotechnology.

  8. Plant Growth Biostimulants, Dietary Feed Supplements and Cosmetics Formulated with Supercritical CO2 Algal Extracts

    OpenAIRE

    Izabela Michalak; Katarzyna Chojnacka; Agnieszka Saeid

    2017-01-01

    The review paper presents the use of algal extracts as safe and solvent-free components of plant growth biostimulants, dietary feed additives and cosmetics. Innovative technology that uses extracts obtained by supercritical CO2 extraction, as a method of isolation of biologically active compounds from algal biomass, is presented. An important part of the complete technology is the final formulation of the product. This enabled realization of the further step which was assessment of the utilit...

  9. Effects of algal food quality on sexual reproduction of Daphnia magna

    OpenAIRE

    Choi, Jong‐Yun; Kim, Seong‐Ki; La, Geung‐Hwan; Chang, Kwang‐Hyeon; Kim, Dong‐Kyun; Jeong, Keon‐Young; Min S. Park; Jo, Hyunbin; Kim, Hyun‐Woo; Jeong, Kwang‐Seuk

    2016-01-01

    Abstract The objective of our study was to investigate sexual reproduction of Daphnia magna associated with mating behaviors and hatching rates, according to different algal food sources. Since a diatom is known to contain more abundant long‐chain poly unsaturated fatty acids (PUFAs), we hypothesized that the diatom‐consuming D. magna would exhibit more successful reproduction rates. Upon the hypothesis, we designed three experiments using two algal species, a green alga (Chlorella vulgaris) ...

  10. A Bi-enzymatic Whole-Cell Algal Biosensor for Monitoring Waste Water Pollutants

    OpenAIRE

    2004-01-01

    International audience; Two algal whole cells biosensors are developed to measure specific toxicity of freshwater pollutants. Both optical and conductometric biosensors are based on inhibition of algal alkaline phosphatase (AP) and esterase activities. Chlorella vulgaris cells are immobilised on a membrane placed in front of an optical fiber bundle for optical sensing or deposited on the surface of an electrode for conductometric sensing. Phosphatase activity of the biosensor is strongly inhi...

  11. Algal Biofuels Strategy. Proceedings from the March 26-27, 2014, Workshop, Charleston, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2014-06-01

    This report is based on the proceedings of the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy’s Bioenergy Technologies Office’s Algal Biofuel Strategy Workshop on March 26-27, 2014, in Charleston, South Carolina. The workshop objective was to convene stakeholders to engage in discussion on strategies over the next 5 to 10 years to achieve affordable, scalable, and sustainable algal biofuels.

  12. Dental implants in growing children

    Directory of Open Access Journals (Sweden)

    S K Mishra

    2013-01-01

    Full Text Available The replacement of teeth by implants is usually restricted to patients with completed craniofacial growth. The aim of this literature review is to discuss the use of dental implants in normal growing patients and in patients with ectodermal dysplasia and the influence of maxillary and mandibular skeletal and dental growth on the stability of those implants. It is recommended that while deciding the optimal individual time point of implant insertion, the status of skeletal growth, the degree of hypodontia, and extension of related psychological stress should be taken into account, in addition to the status of existing dentition and dental compliance of a pediatric patient.

  13. Memory effect in growing trees

    OpenAIRE

    Malarz, K.; Kulakowski, K.

    2003-01-01

    We show that the structure of a growing tree preserves an information on the shape of an initial graph. For the exponential trees, evidence of this kind of memory is provided by means of the iterative equations, derived for the moments of the node-node distance distribution. Numerical calculations confirm the result and allow to extend the conclusion to the Barabasi--Albert scale-free trees. The memory effect almost disappears, if subsequent nodes are connected to the network with more than o...

  14. Direct utilization of waste water algal biomass for ethanol production by cellulolytic Clostridium phytofermentans DSM1183.

    Science.gov (United States)

    Fathima, Anwar Aliya; Sanitha, Mary; Kumar, Thangarathinam; Iyappan, Sellamuthu; Ramya, Mohandass

    2016-02-01

    Direct bioconversion of waste water algal biomass into ethanol using Clostridium phytofermentans DSM1183 was demonstrated in this study. Fermentation of 2% (w/v) autoclaved algal biomass produced ethanol concentration of 0.52 g L(-1) (solvent yield of 0.19 g/g) where as fermentation of acid pretreated algal biomass (2%, w/v) produced ethanol concentration of 4.6 g L(-1) in GS2 media (solvent yield of 0.26 g/g). The control experiment with 2% (w/v) glucose in GS2 media produced ethanol concentration of 2.8 g L(-1) (solvent yield of 0.25 g/g). The microalgal strains from waste water algal biomass were identified as Chlamydomonas dorsoventralis, Graesiella emersonii, Coelastrum proboscideum, Scenedesmus obliquus, Micractinium sp., Desmodesmus sp., and Chlorella sp., based on ITS-2 molecular marker. The presence of glucose, galactose, xylose and rhamnose were detected by high performance liquid chromatography in the algal biomass. Scanning Electron Microscopy observations of fermentation samples showed characteristic morphological changes in algal cells and bioaccessibility of C. phytofermentans.

  15. Removing nitrogen and phosphorus from simulated wastewater using algal biofilm technique

    Institute of Scientific and Technical Information of China (English)

    Qun WEI; Zhiquan HU; Genbao LI; Bo XIAO; Hao SUN; Meiping TAO

    2008-01-01

    Algal biofilm technology is a new and advanced wastewater treatment method. Experimental study on removing nitrogen and phosphorus from simulated waste-water using algal biofilm under the continuous light of 3500 Lux in the batch and continuous systems was carried out in this paper to assess the performance of algal biofilm in removing nutrients. The results showed that the effect of removing nitrogen and phosphorus by algal biofilm was remarkable in the batch system. The removal efficiencies of total phosphorus (TP), total nitrogen (TN), ammonia-nitrogen (NH3-N), and chemical oxygen demand (COD) reached 98.17%, 86.58%, 91.88%, and 97.11%, respect-ively. In the continuous system, hydraulic retention time (HRT) of 4 days was adopted; the effects of removing TP, TN, NH3-N, and COD by algal biofilm were very stable. During a run of 24 days, the removal efficiencies of TP, TN, NH3-N, and COD reached 95.38%, 83.93%, 82.38%, and 92.31%, respectively. This study demonstrates the feasibility of removing nitrogen and phosphorus from simulated wastewater using algal biofilm.

  16. Investigating why recycling gravity harvested algae increases harvestability and productivity in high rate algal ponds.

    Science.gov (United States)

    Park, J B K; Craggs, R J; Shilton, A N

    2013-09-15

    It has previously been shown that recycling gravity harvested algae promotes Pediastrum boryanum dominance and improves harvestability and biomass production in pilot-scale High Rate Algal Ponds (HRAPs) treating domestic wastewater. In order to confirm the reproducibility of these findings and investigate the mechanisms responsible, this study utilized twelve 20 L outdoor HRAP mesocosms operated with and without algal recycling. It then compared the recycling of separated solid and liquid components of the harvested biomass against un-separated biomass. The work confirmed that algal recycling promoted P. boryanum dominance, improved 1 h-settleability by >20% and increased biomass productivity by >25% compared with controls that had no recycling. With regard to the improved harvestability, of particular interest was that recycling the liquid fraction alone caused a similar improvement in settleability as recycling the solid fraction. This may be due to the presence of extracellular polymeric substances in the liquid fraction. While there are many possible mechanisms that could account for the increased productivity with algal recycling, all but two were systematically eliminated: (i) the mean cell residence time was extended thereby increasing the algal concentration and more fully utilizing the incident sunlight and, (ii) the relative proportions of algal growth stages (which have different specific growth rates) was changed, resulting in a net increase in the overall growth rate of the culture.

  17. Safety evaluation of DHA-rich Algal Oil from Schizochytrium sp.

    Science.gov (United States)

    Fedorova-Dahms, I; Marone, P A; Bauter, M; Ryan, A S

    2011-12-01

    The safety of DHA-rich Algal Oil from Schizochytrium sp. containing 40-45 wt% DHA and up to 10 wt% EPA was evaluated by testing for gene mutations, clastogenicity and aneugenicity, and in a subchronic 90-day Sprague-Dawley rat dietary study with in utero exposure, followed by a 4-week recovery phase. The results of all genotoxicity tests were negative. In the 90-day study, DHA-rich Algal Oil was administered at dietary levels of 0.5, 1.5, and 5 wt% along with two control diets: a standard low-fat basal diet and a basal diet supplemented with 5 wt% of concentrated Fish Oil. There were no treatment-related effects of DHA-rich Algal Oil on clinical observations, body weight, food consumption, behavior, hematology, clinical chemistry, coagulation, or urinalysis. Increases in absolute and relative weights of the liver, kidney, spleen and adrenals (adrenals and spleen with histological correlates) were observed in both the Fish Oil- and the high-dose of DHA-rich Algal Oil-treated females and were not considered to be adverse. The no observed adverse effect level (NOAEL) for DHA-rich Algal Oil under the conditions of this study was 5 wt% in the diet, equivalent to an overall average DHA-rich Algal Oil intake of 4260 mg/kg bw/day for male and female rats.

  18. Toxicologic evaluation of DHA-rich algal oil: Genotoxicity, acute and subchronic toxicity in rats.

    Science.gov (United States)

    Schmitt, D; Tran, N; Peach, J; Bauter, M; Marone, P

    2012-10-01

    DHA-rich algal oil ONC-T18, tested in a battery of in vitro and in vivo genotoxicity tests, did not show mutagenic or genotoxic potential. The acute oral LD50 in rats has been estimated to be greater than 5000 mg/kg of body weight. In a 90-day subchronic dietary study, administration of DHA-rich algal oil at concentrations of 0, 10,000, 25,000, and 50,000 ppm in the diet for 13 weeks did not produce any significant toxicologic manifestations. The algal oil test article was well tolerated as evidenced by the absence of major treatment-related changes in the general condition and appearance of the rats, neurobehavioral endpoints, growth, feed and water intake, ophthalmoscopic examinations, routine hematology and clinical chemistry parameters, urinalysis, or necropsy findings. The no observed adverse effect level (NOAEL) was the highest level fed of 50,000 ppm which is equivalent to 3,305 and 3,679 mg/kg bw/day, for male and female rats, respectively. The studies were conducted as part of an investigation to examine the safety of DHA-rich algal oil. The results confirm that it possesses a toxicity profile similar to other currently marketed algal oils and support the safety of DHA-rich algal oil for its proposed use in food.

  19. What a Pain! Kids and Growing Pains

    Science.gov (United States)

    ... What Happens in the Operating Room? What a Pain! Kids and Growing Pains KidsHealth > For Kids > What a Pain! Kids and ... something doctors call growing pains . What Are Growing Pains? Growing pains aren't a disease. You probably ...

  20. Intraspecific Diversity and Ecological Zonation in Coral-Algal Symbiosis

    Science.gov (United States)

    Rowan, Rob; Knowlton, Nancy

    1995-03-01

    All reef-building corals are obligately associated with photosynthetic microalgal endosymbionts called zooxanthellae. Zooxanthella taxonomy has emphasized differences between species of hosts, but the possibility of ecologically significant zooxanthella diversity within hosts has been the subject of speculation for decades. Analysis of two dominant Caribbean corals showed that each associates with three taxa of zooxanthellae that exhibit zonation with depth-the primary environmental gradient for light-dependent marine organisms. Some colonies apparently host two taxa of symbionts in proportions that can vary across the colony. This common occurrence of polymorphic, habitat-specific symbioses challenges conventional understanding of the units of biodiversity but also illuminates many distinctive aspects of marine animal-algal associations. Habitat specificity provides ecological explanations for the previously documented poor concordance between host and symbiont phylogenies and the otherwise surprising lack of direct, maternal transmission of symbionts in many species of hosts. Polymorphic symbioses may underlie the conspicuous and enigmatic variability characteristic of responses to environmental stress (e.g., coral "bleaching") and contribute importantly to the phenomenon of photoadaptation.

  1. The highly reduced genome of an enslaved algal nucleus.

    Science.gov (United States)

    Douglas, S; Zauner, S; Fraunholz, M; Beaton, M; Penny, S; Deng, L T; Wu, X; Reith, M; Cavalier-Smith, T; Maier, U G

    2001-04-26

    Chromophyte algae differ fundamentally from plants in possessing chloroplasts that contain chlorophyll c and that have a more complex bounding-membrane topology. Although chromophytes are known to be evolutionary chimaeras of a red alga and a non-photosynthetic host, which gave rise to their exceptional membrane complexity, their cell biology is poorly understood. Cryptomonads are the only chromophytes that still retain the enslaved red algal nucleus as a minute nucleomorph. Here we report complete sequences for all three nucleomorph chromosomes from the cryptomonad Guillardia theta. This tiny 551-kilobase eukaryotic genome is the most gene-dense known, with only 17 diminutive spliceosomal introns and 44 overlapping genes. Marked evolutionary compaction hundreds of millions of years ago eliminated nearly all the nucleomorph genes for metabolic functions, but left 30 for chloroplast-located proteins. To allow expression of these proteins, nucleomorphs retain hundreds of genetic-housekeeping genes. Nucleomorph DNA replication and periplastid protein synthesis require the import of many nuclear gene products across endoplasmic reticulum and periplastid membranes. The chromosomes have centromeres, but possibly only one loop domain, offering a means for studying eukaryotic chromosome replication, segregation and evolution.

  2. Anaerobic digestion of nitrophilic algal biomass from the Venice Lagoon

    Energy Technology Data Exchange (ETDEWEB)

    Rigoni-Stern, S.; Rismondo, R. (Technital S.p.A., Verona (IT)); Szpyrkowicz, L.; Zilio-Grandi, F. (Venice Univ. (Italy)); Vigato, P.A. (Consiglio Nazionale delle Ricerche, Padua (Italy). Lab. di Chimica e Tecnologia dei Radioelementi)

    1990-01-01

    The feasibility of producing biogas by anaerobic digestion of a nitrophilic algae biomass obtained from the highly eutrophicated Venice Lagoon has been investigated. Methods for harvesting algal biomass have been examined in detail and different pretreatments used prior to analysis and digestion of the algae described. Results obtained from three pilot plant digesters over a period of 12 months using Ulva rigida and Gracilaria as feed material gave no indication of inhibition of the process by either high salinity or high metals content resulting from pollutants discharged into the lagoon. Sulphides were formed during digestion as a consequence of the high sulphate content of the interstitial water as well as the level of sulphur present in the algae. However, the sulphides did not appear to cause inhibition or result in a reduction in gas yield. A maximum biogas production rate of 0.347 m{sup 3} kg VS{sup -1} day{sup -1} was obtained during digestion at a retention time of 20 days with an organic loading rate of 1 kg VS m{sup -3} day{sup -1}. (author).

  3. Hydrogen production from algal biomass via steam gasification.

    Science.gov (United States)

    Duman, Gozde; Uddin, Md Azhar; Yanik, Jale

    2014-08-01

    Algal biomasses were tested as feedstock for steam gasification in a dual-bed microreactor in a two-stage process. Gasification experiments were carried out in absence and presence of catalyst. The catalysts used were 10% Fe₂O₃-90% CeO₂ and red mud (activated and natural forms). Effects of catalysts on tar formation and gasification efficiencies were comparatively investigated. It was observed that the characteristic of algae gasification was dependent on its components and the catalysts used. The main role of the catalyst was reforming of the tar derived from algae pyrolysis, besides enhancing water gas shift reaction. The tar reduction levels were in the range of 80-100% for seaweeds and of 53-70% for microalgae. Fe₂O₃-CeO₂ was found to be the most effective catalyst. The maximum hydrogen yields obtained were 1036 cc/g algae for Fucus serratus, 937 cc/g algae for Laminaria digitata and 413 cc/g algae for Nannochloropsis oculata.

  4. Impact of iron porphyrin complexes when hydroprocessing algal HTL biocrude

    Energy Technology Data Exchange (ETDEWEB)

    Jarvis, Jacqueline M.; Sudasinghe, Nilusha M.; Albrecht, Karl O.; Schmidt, Andrew J.; Hallen, Richard T.; Anderson, Daniel B.; Billing, Justin M.; Schaub, Tanner M.

    2016-10-01

    We apply Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) for direct characterization of iron-porphyrins in hydrothermal liquefaction (HTL) biocrude oils derived from two algae: Tetraselmis sp. and cyanobacteria. The ironporphyrin compounds are shown to cause catalyst bed plugging during hydroprocessing due to iron deposition. Inductively-coupled plasma optical emission spectrometry (ICPOES) was utilized for iron quantitation in the plugged catalyst beds formed through hydroprocessing of the two HTL biocrudes and identifies an enrichment of iron in the upper five centimeters of the catalyst bed for Tetraselmis sp. (Fe=100,728 ppm) and cyanobacteria (Fe=115,450 ppm). Direct infusion FT-ICR MS analysis of the two HTL biocrudes with optimized instrument conditions facilitates rapid screening and identification of iron-porphyrins without prior chromatographic separation. With FT-ICR MS we identify 138 unique iron-porphyrin compounds in the two HTL biocrudes that are structurally similar to metal-porphyrins (e.g. Ni and V) observed in petroleum. No ironporphyrins are observed in the cyanobacteria HTL biocrude after hydroprocessing, which indicates that iron-porphyrin structures in the HTL biocrude are degraded during hydroprocessing. Hydrodemetallization reactions that occur through hydroprocessing of HTL biocrudes could be responsible for the decomposition of iron-porphyrin structures leading to metal deposition in the catalyst bed that result in catalyst deactivation and bed plugging, and must be addressed for effective upgrading of algal HTL biocrudes.

  5. Expanding Fungal Diets Through Synthetic Algal-Fungal Mutualism

    Science.gov (United States)

    Sharma, Alaisha; Galazka, Jonathan (Editor)

    2015-01-01

    Fungi can synthesize numerous molecules with important properties, and could be valuable production platforms for space exploration and colonization. However, as heterotrophs, fungi require reduced carbon. This limits their efficiency in locations such as Mars, where reduced carbon is scarce. We propose a system to induce mutualistic symbiosis between the green algae Chlamydomonas reinhardtii and the filamentous fungi Neurospora crassa. This arrangement would mimic natural algal-fungal relationships found in lichens, but have added advantages including increased growth rate and genetic tractability. N. crassa would metabolize citrate (C6H5O7 (sup -3)) and release carbon dioxide (CO2) that C. reinhardtii would assimilate into organic sugars during photosynthesis. C. reinhardtii would metabolize nitrate (NO3-) and release ammonia (NH3) as a nitrogen source for N. crassa. A N. crassa mutant incapable of reducing nitrate will be used to force this interaction. This system eliminates the need to directly supply its participants with carbon dioxide and ammonia. Furthermore, the release of oxygen by C. reinhardtii via photosynthesis would enable N. crassa to respire. We hope to eventually create a system closer to lichen, in which the algae transfers not only nitrogen but reduced carbon, as organic sugars, to the fungus for growth and production of valuable compounds.

  6. Enhancing Algal Growth by Stimulation with LED Lighting and Ultrasound

    Directory of Open Access Journals (Sweden)

    Shao-Yi Hsia

    2015-01-01

    Full Text Available Algae are not only rich in natural nutrients, but are also a high-priced health food. An important constituent called “growth factor” is extracted from algae and used as an ingredient in medical drugs, foods, cosmetics, and other products. Its enormous potential market should not be taken lightly. Algae are mostly found near coastal areas and their habitats are limited by a number of natural factors, leading to large labor and financial expenditures to harvest. This report describes our study of indoor algae production using LED lights and ultrasound and manipulating other growth factors at different temperatures. Ultrasound treatment at the alga’s natural resonant frequency was varied to determine optimal algal growth using the Taguchi method to plan and to analyze the experiments. The results were very satisfying, showing an 8.23% increase in the growth rate by the fifth day due to ultrasound treatment and an amazing 27.01% growth rate due to biomechanical stimulation.

  7. Blueprint and Approach to Grow Revenue in Small Technology Companies

    Directory of Open Access Journals (Sweden)

    Tony Bailetti

    2010-05-01

    Full Text Available This article examines a new approach to grow the revenue of small technology companies and technology startups. We name this new approach the business ecosystem approach. The article is organized into five sections. The first section provides a blueprint to grow revenue and an inventory of growth formulas that top management teams of small technology companies and founders of startups find useful. The second section briefly defines business ecosystems, keystones and platforms. The third section describes the business ecosystem approach to grow the revenue of small technology companies and technology startups. It compares the traditional and business ecosystem approaches to growing revenue; identifies when the business ecosystem approach works better than the traditional approach; explains what small companies and startups need to do to grow revenue using the business ecosystem approach; and describes the benefits and risks of implementing the business ecosystem approach. The fourth section compares three approaches to growing revenue and highlights the differences between i business ecosystems and development communities and ii the business ecosystem approach and outsourcing. The fifth section identifies the key decisions a small technology company or technology startup needs to make to become the keystone that anchors a business ecosystem.

  8. Algal and Water-Quality Data for Rapid Creek and Canyon Lake near Rapid City, South Dakota, 2007

    Science.gov (United States)

    Hoogestraat, Galen K.; Putnam, Larry D.; Graham, Jennifer L.

    2008-01-01

    This report summarizes the results of algae and water-quality sampling on Rapid Creek and Canyon Lake during May and September 2007. The overall purpose of the study was to determine the algal community composition of Rapid Creek and Canyon Lake in relation to organisms that are known producers of unwanted tastes and odors in drinking-water supplies. Algal assemblage structure (phytoplankton and periphyton) was examined at 16 sites on Rapid Creek and Canyon Lake during May and September 2007, and actinomycetes bacteria were sampled at the Rapid City water treatment plant intake in May 2007, to determine if taste-and-odor producing organisms were present. During the May 2007 sampling, 3 Rapid Creek sites and 4 Canyon Lake sites were quantitatively sampled for phytoplankton in the water column, 7 Rapid Creek sites were quantitatively sampled for attached periphyton, and 4 lake and retention pond sites were qualitatively sampled for periphyton. Five Rapid Creek sites were sampled for geosmin and 2-methylisoborneol, two common taste-and-odor causing compounds known to affect water supplies. During the September 2007 sampling, 4 Rapid Creek sites were quantitatively sampled for attached periphyton, and 3 Canyon Lake sites were qualitatively sampled for periphyton. Water temperature, dissolved oxygen, pH, and specific conductance were measured during each sampling event. Methods of collection and sample analysis are presented for the various types of biological and chemical constituent samples. Diatoms comprised 91-100 percent of the total algal biovolume in periphyton samples collected during May and September. Cyanobacteria (also called blue-green algae) were detected in 7 of the 11 quantitative periphyton samples and ranged from 0.01 to 2.0 percent of the total biovolume. Cyanobacteria were present in 3 of the 7 phytoplankton samples collected in May, but the relative biovolumes were small (0.01-0.2 percent). Six of seven qualitative samples collected from Canyon Lake

  9. First steps of ecological restoration in Mediterranean lagoons: Shifts in phytoplankton communities

    Science.gov (United States)

    Leruste, A.; Malet, N.; Munaron, D.; Derolez, V.; Hatey, E.; Collos, Y.; De Wit, R.; Bec, B.

    2016-10-01

    Along the French Mediterranean coast, a complex of eight lagoons underwent intensive eutrophication over four decades, mainly related to nutrient over-enrichment from continuous sewage discharges. The lagoon complex displayed a wide trophic gradient from mesotrophy to hypertrophy and primary production was dominated by phytoplankton communities. In 2005, the implementation of an 11 km offshore outfall system diverted the treated sewage effluents leading to a drastic reduction of anthropogenic inputs of nitrogen and phosphorus into the lagoons. Time series data have been examined from 2000 to 2013 for physical, chemical and biological (phytoplankton) variables of the water column during the summer period. Since 2006, total nitrogen and phosphorus concentrations as well as chlorophyll biomass strongly decreased revealing an improvement in lagoon water quality. In summertime, the decline in phytoplankton biomass was accompanied by shifts in community structure and composition that could be explained by adopting a functional approach by considering the common functional traits of the main algal groups. These phytoplankton communities were dominated by functional groups of small-sized and fast-growing algae (diatoms, cryptophytes and green algae). The trajectories of summer phytoplankton communities displayed a complex response to changing nutrient loads over time. While diatoms were the major group in 2006 in all the lagoons, the summer phytoplankton composition in hypertrophic lagoons has shifted towards green algae, which are particularly well adapted to summertime conditions. All lagoons showed increasing proportion and occurrence of peridinin-rich dinophytes over time, probably related to their capacity for mixotrophy. The diversity patterns were marked by a strong variability in eutrophic and hypertrophic lagoons whereas phytoplankton community structure reached the highest diversity and stability in mesotrophic lagoons. We observe that during the re

  10. Growing bubbles rising in line

    Directory of Open Access Journals (Sweden)

    John F. Harper

    2001-01-01

    Full Text Available Over many years the author and others have given theories for bubbles rising in line in a liquid. Theory has usually suggested that the bubbles will tend towards a stable distance apart, but experiments have often showed them pairing off and sometimes coalescing. However, existing theory seems not to deal adequately with the case of bubbles growing as they rise, which they do if the liquid is boiling, or is a supersaturated solution of a gas, or simply because the pressure decreases with height. That omission is now addressed, for spherical bubbles rising at high Reynolds numbers. As the flow is then nearly irrotational, Lagrange's equations can be used with Rayleigh's dissipation function. The theory also works for bubbles shrinking as they rise because they dissolve.

  11. Viking Disruptions or Growing Integration?

    DEFF Research Database (Denmark)

    Sindbæk, Søren Michael

    2012-01-01

    Long-distance communication has emerged as a particular focus for archaeological exploration using network theory, analysis, and modelling. Initial attempts to adapt methods from social network analysis to archaeological data have, however, struggled to produce decisive results. This paper...... demonstrates how formal network analysis can be combined with a contextual reading of evidence relating to a long-distance communication network in the past. A study of the combined distributions of ten vessel types in 152 settlement sites from the 10th century suggests the outline of the core structure...... of the network. The model implies that 10th century long-distance exchange in the North Sea region featured long-distance links equal to those of the Carolingian emporia trade, and represented a growth in terms of new axes of integration, above all the growing links between the Scandinavian Peninsula...

  12. A novel antibody-based biomarker for chronic algal toxin exposure and sub-acute neurotoxicity.

    Directory of Open Access Journals (Sweden)

    Kathi A Lefebvre

    Full Text Available The neurotoxic amino acid, domoic acid (DA, is naturally produced by marine phytoplankton and presents a significant threat to the health of marine mammals, seabirds and humans via transfer of the toxin through the foodweb. In humans, acute exposure causes a neurotoxic illness known as amnesic shellfish poisoning characterized by seizures, memory loss, coma and death. Regular monitoring for high DA levels in edible shellfish tissues has been effective in protecting human consumers from acute DA exposure. However, chronic low-level DA exposure remains a concern, particularly in coastal and tribal communities that subsistence harvest shellfish known to contain low levels of the toxin. Domoic acid exposure via consumption of planktivorous fish also has a profound health impact on California sea lions (Zalophus californianus affecting hundreds of animals yearly. Due to increasing algal toxin exposure threats globally, there is a critical need for reliable diagnostic tests for assessing chronic DA exposure in humans and wildlife. Here we report the discovery of a novel DA-specific antibody response that is a signature of chronic low-level exposure identified initially in a zebrafish exposure model and confirmed in naturally exposed wild sea lions. Additionally, we found that chronic exposure in zebrafish caused increased neurologic sensitivity to DA, revealing that repetitive exposure to DA well below the threshold for acute behavioral toxicity has underlying neurotoxic consequences. The discovery that chronic exposure to low levels of a small, water-soluble single amino acid triggers a detectable antibody response is surprising and has profound implications for the development of diagnostic tests for exposure to other pervasive environmental toxins.

  13. A novel antibody-based biomarker for chronic algal toxin exposure and sub-acute neurotoxicity

    Science.gov (United States)

    Lefebvre, Kathi A.; Frame, Elizabeth R.; Gulland, Frances; Hansen, John D.; Kendrick, Preston S.; Beyer, Richard P.; Bammler, Theo K.; Farin, Frederico M.; Hiolski, Emma M.; Smith, Donald R.; Marcinek, David J.

    2012-01-01

    The neurotoxic amino acid, domoic acid (DA), is naturally produced by marine phytoplankton and presents a significant threat to the health of marine mammals, seabirds and humans via transfer of the toxin through the foodweb. In humans, acute exposure causes a neurotoxic illness known as amnesic shellfish poisoning characterized by seizures, memory loss, coma and death. Regular monitoring for high DA levels in edible shellfish tissues has been effective in protecting human consumers from acute DA exposure. However, chronic low-level DA exposure remains a concern, particularly in coastal and tribal communities that subsistence harvest shellfish known to contain low levels of the toxin. Domoic acid exposure via consumption of planktivorous fish also has a profound health impact on California sea lions (Zalophus californianus) affecting hundreds of animals yearly. Due to increasing algal toxin exposure threats globally, there is a critical need for reliable diagnostic tests for assessing chronic DA exposure in humans and wildlife. Here we report the discovery of a novel DA-specific antibody response that is a signature of chronic low-level exposure identified initially in a zebrafish exposure model and confirmed in naturally exposed wild sea lions. Additionally, we found that chronic exposure in zebrafish caused increased neurologic sensitivity to DA, revealing that repetitive exposure to DA well below the threshold for acute behavioral toxicity has underlying neurotoxic consequences. The discovery that chronic exposure to low levels of a small, water-soluble single amino acid triggers a detectable antibody response is surprising and has profound implications for the development of diagnostic tests for exposure to other pervasive environmental toxins.

  14. Mollusc-algal chloroplast endosymbiosis. Photosynthesis, thylakoid protein maintenance, and chloroplast gene expression continue for many months in the absence of the algal nucleus.

    Science.gov (United States)

    Green, B J; Li, W Y; Manhart, J R; Fox, T C; Summer, E J; Kennedy, R A; Pierce, S K; Rumpho, M E

    2000-09-01

    Early in its life cycle, the marine mollusc Elysia chlorotica Gould forms an intracellular endosymbiotic association with chloroplasts of the chromophytic alga Vaucheria litorea C. Agardh. As a result, the dark green sea slug can be sustained in culture solely by photoautotrophic CO(2) fixation for at least 9 months if provided with only light and a source of CO(2). Here we demonstrate that the sea slug symbiont chloroplasts maintain photosynthetic oxygen evolution and electron transport activity through photosystems I and II for several months in the absence of any external algal food supply. This activity is correlated to the maintenance of functional levels of chloroplast-encoded photosystem proteins, due in part at least to de novo protein synthesis of chloroplast proteins in the sea slug. Levels of at least one putative algal nuclear encoded protein, a light-harvesting complex protein homolog, were also maintained throughout the 9-month culture period. The chloroplast genome of V. litorea was found to be 119.1 kb, similar to that of other chromophytic algae. Southern analysis and polymerase chain reaction did not detect an algal nuclear genome in the slug, in agreement with earlier microscopic observations. Therefore, the maintenance of photosynthetic activity in the captured chloroplasts is regulated solely by the algal chloroplast and animal nuclear genomes.

  15. Vegetation of Europe: hierarchical floristic classification system of vascular plant, bryophyte, lichen, and algal communities

    NARCIS (Netherlands)

    Mucina, L.; Bültmann, Helga; Dierssen, Klaus; Theurillat, Jean-Paul; Raus, Thomas; Carni, Andraz; Šumberová, Kateřina; Willner, Wolfgang; Dengler, J.; Schaminee, J.H.J.; Hennekens, S.M.

    2016-01-01

    Aims: Vegetation classification consistent with the Braun-Blanquet approach is
    widely used in Europe for applied vegetation science, conservation planning
    and landmanagement. During the long history of syntaxonomy,many concepts
    and names of vegetation units have been proposed, but there

  16. Limited flexibility in resource use in a coral reef grazer foraging on seasonally changing algal communities

    NARCIS (Netherlands)

    Afeworki, Y.; Bruggemann, J. H.; Videler, J. J.

    2011-01-01

    Feeding ecology of three life phases of the parrotfish Scarus ferrugineus was studied on a southern Red Sea fringing reef by comparing availability and consumption of benthic algae during the monsoon hot and cool seasons. Dominant biota covering dead carbonate substrates were in decreasing order of

  17. The effects of trophic interactions and spatial competition on algal community composition on Hawaiian coral reefs

    NARCIS (Netherlands)

    Vermeij, M.J.A.; Dailer, M.L.; Walsh, S.M.; Donovan, M.K.; Smith, C.M.

    2010-01-01

    Much of coral reef ecology has focused on how human impacts change coral reefs to macroalgal reefs. However, macroalgae may not always be a good indicator of reef decline, especially on reefs with significant sea urchin populations, as found in Kenya and Hawaii. This study tests the effects of troph

  18. Honey oil burns: a growing problem.

    Science.gov (United States)

    Jensen, Guy; Bertelotti, Robert; Greenhalgh, David; Palmieri, Tina; Maguina, Pirko

    2015-01-01

    There is an emerging mechanism of burn injury as a result of the ignition of butane, during the manufacture of a tetrahydrocannabinol concentrate known as butane honey oil. The authors report of a series of patients who presented with this mechanism of injury and a description of the process that causes these burns. Patient data were gathered from the medical records of eight patients treated at the University of California Davis Medical Center and Shriners Hospital of Northern California. Information on the manufacturing process of butane honey oil was gathered from Internet searches and published literature on the topic. The burns witnessed at the abovementioned institutions ranged from 16 to 95% TBSA, with an average of 49.9%. The average length of stay for the patients was 118.3 hospital days and 114.4 intensive care unit days, with an average of 43.8 days spent on mechanical ventilation. The average age of patients was 22 years, with only one patient above the age of 30 years. Accidents during honey oil production have resulted in a surge of burn injuries in our community during the past year. The manufacture of this product, which involves the use of volatile butane gas, is gaining in popularity. Although considered to be safer than previous methods, multiple casualties with extensive burn injuries have resulted from this process. Associated injuries from blast trauma or chemical burns are not likely to occur in these types of explosions and have not been observed in the series reported in this article. In light of the increasing popularity of honey oil, it is important for burn care providers to gain awareness and understanding of this problem and its growing presence in the community.

  19. Harmful Algal Bloom in Iligan Bay, Southern Philippines

    Directory of Open Access Journals (Sweden)

    Helen J Vicente

    2002-12-01

    Full Text Available We report the first occurrence of harmful algal bloom (HAB caused by a non-toxic dinoflagellate, Cochlodinium sp. in Philippine waters, particularly, in Kalangahan Pt.-Manticao Pt., Iligan Bay on March 13-18, 2002. Two patches of Cochlodinium sp. bloom, associated with fish kills in Kalangahan Pt.-Mantacao Pt., Iligan Bay, caused localized water discoloration from the usual ocean blue to rusty brown or reddish brown to blackish. The first patch, located near fish-aggregating device (FAD areas, spanned 2 km wide, while the second patch, located near a fish corral, spanned 500m wide. These patches occupied the water column from surface to 5 m depth, but a thick mat formed at 0.5 m to surface. Patches occupied the water column from surface to 5 m depth, but a thick mat formed at 0.5 m to surface. Patches decreased as the bloom began to decline. The observed dead demersal and pelagic fishes coincided with highest bloom density of 3.1 x 104 to 3.8 x 104 cells ml-1 of Cochlodinium. Dissected gills and stomach contents of fishes killed in HAB-affected areas did not reveal any indication of clogging of gills by Cochlodinium sp. Fishes covered by the “shading effect” of Cochlodinium bloom may have suffered anoxia or asphyxation due to oxygen depletion. No poisoning of people who consumed the dead fishes was reported. Laboratory analyses revealed lower DO values, 2.4 to 0.5 mg L-1from 2400 to 0600Hr; 14N:1P ratio; air-water temperature ranged from 28-29°C; pH 7.89-8.29; and salinity, 33-35°/oo. Favella sp., a tintinnid grazer of dinoflagellate was developing in the area at the termination of the Cochlodinium bloom on March 18.

  20. Strategies for optimizing algal biology for enhanced biomass production

    Directory of Open Access Journals (Sweden)

    Amanda N. Barry

    2015-02-01

    Full Text Available One of the more environmentally sustainable ways to produce high energy density (oils feed stocks for the production of liquid transportation fuels is from biomass. Photosynthetic carbon capture combined with biomass combustion (point source and subsequent carbon capture and sequestration (BECCS has also been proposed in the Intergovernmental Panel on Climate Change Report as one of the most effective and economical strategies to remediate atmospheric greenhouse gases. To maximize photosynthetic carbon capture efficiency and energy-return-on-investment, we must develop biomass production systems that achieve the greatest yields with the lowest inputs. Numerous studies have demonstrated that microalgae have among the greatest potentials for biomass production. This is in part due to the fact that all alga cells are photoautotrophic, they have active carbon concentrating mechanisms to increase photosynthetic productivity, and all the biomass is harvestable unlike plants. All photosynthetic organisms, however, convert only a fraction of the solar energy they capture into chemical energy (reduced carbon or biomass. To increase aerial carbon capture rates and biomass productivity it will be necessary to identify the most robust algal strains and increase their biomass production efficiency often by genetic manipulation. We review recent large-scale efforts to identify the best biomass producing strains and metabolic engineering strategies to improve aerial productivity. These strategies include optimization of photosynthetic light-harvesting antenna size to increase energy capture and conversion efficiency and the potential development of advanced molecular breeding techniques. To date, these strategies have resulted in up to two-fold increases in biomass productivity.

  1. Uncovering Adiponectin Replenishing Property of Sujiaonori Algal Biomaterial in Humans.

    Science.gov (United States)

    Ngatu, Nlandu Roger; Ikeda, Mitsunori; Watanabe, Hiroyuki; Tanaka, Mamoru; Inoue, Masataka; Kanbara, Sakiko; Nojima, Sayumi

    2017-02-08

    The replenishment of adiponectin-an adipocyte-derived hormone with salutary health effects-has recently been proposed as a new approach to treat hypertension, also ameliorate cardiovascular and metabolic risks. We conducted a prospective placebo-controlled, non-randomized and investigator-blinded dietary intervention study to evaluate the health effects of dietary intake of Sujiaonori (Ulva/Enteromorpha prolifera Müller) algal biomaterial (SBM), especially on adiponectin production, blood pressure (BP), and body mass index (BMI) in human subjects. Participants (N = 32) were divided into two equally sized groups (n = 16 for each group): SBM group (subjects supplemented with 3 g SBM powder twice a day during meal) and the control group (subjects who took 3 g of a supplement made of 70% corn starch powder and 30% spinach twice a day) for four weeks. Two health survey questionnaires (dietary and current health questionnaires) were completed anonymously, saliva sampling was done for adiponectin measurement by ELISA, and blood pressure (BP) and anthropometric parameters were measured at baseline and four weeks later. Student paired t-test was performed to compare baseline and post-intervention data on outcome variables between the two study groups. Results showed a 2.24-fold increase in adiponectin level in SBM group (2.81 and 6.26 ng/mL at baseline and at the end of study, respectively) (p 0.05). In SBM subjects, an improvement of BP profile was noted with a significant decrease in systolic BP (p < 0.01). A positive correlation was found between SBM supplementation and adiponectin level, whereas an inverse correlation was noted between SBM supplementation and blood pressure, and also BMI. These findings suggest that SBM-increased adiponectin level and improved BP in a sample of Japanese young adults, and has the potential to improve blood pressure in humans.

  2. Skill assessment for an operational algal bloom forecast system

    Science.gov (United States)

    Stumpf, Richard P.; Tomlinson, Michelle C.; Calkins, Julie A.; Kirkpatrick, Barbara; Fisher, Kathleen; Nierenberg, Kate; Currier, Robert; Wynne, Timothy T.

    2010-01-01

    An operational forecast system for harmful algal blooms (HABs) in southwest Florida is analyzed for forecasting skill. The HABs, caused by the toxic dinoflagellate, Karenia brevis, lead to shellfish toxicity and to respiratory irritation. In addition to predicting new blooms and their extent, HAB forecasts are made twice weekly during a bloom event, using a combination of satellite derived image products, wind predictions, and a rule-based model derived from previous observations and research. These forecasts include: identification, intensification, transport, extent, and impact; the latter being the most significant to the public. Identification involves identifying new blooms as HABs and is validated against an operational monitoring program involving water sampling. Intensification forecasts, which are much less frequently made, can only be evaluated with satellite data on mono-specific blooms. Extent and transport forecasts of HABs are also evaluated against the water samples. Due to the resolution of the forecasts and available validation data, skill cannot be resolved at scales finer than 30 km. Initially, respiratory irritation forecasts were analyzed using anecdotal information, the only available data, which had a bias toward major respiratory events leading to a forecast accuracy exceeding 90%. When a systematic program of twice-daily observations from lifeguards was implemented, the forecast could be meaningfully assessed. The results show that the forecasts identify the occurrence of respiratory events at all lifeguard beaches 70% of the time. However, a high rate (80%) of false positive forecasts occurred at any given beach. As the forecasts were made at half to whole county level, the resolution of the validation data was reduced to county level, reducing false positives to 22% (accuracy of 78%). The study indicates the importance of systematic sampling, even when using qualitative descriptors, the use of validation resolution to evaluate forecast

  3. Multigene phylogeny of the red algal subclass Nemaliophycidae.

    Science.gov (United States)

    Lam, Daryl W; Verbruggen, Heroen; Saunders, Gary W; Vis, Morgan L

    2016-01-01

    The red algae (Rhodophyta) are a lineage of primary endosymbionts whose ancestors represent some of the first photosynthetic eukaryotes on the planet. They primarily inhabit marine ecosystems, with only ∼5% of species found in freshwater systems. The subclass Nemaliophycidae is very diverse in ecological and life history features and therefore a useful model to study these traits, but the phylogenetic relationships among the orders are, for the most part, poorly resolved. To elucidate the phylogeny of the Nemaliophycidae, we constructed a nine-gene dataset comprised of nuclear, plastid, and mitochondrial markers for 67 red algal specimens. The resulting maximum likelihood (ML) phylogeny confirmed the monophyly of all orders. The sister relationship of the Acrochaetiales and Palmariales received high support and the relationship of the Balliales with Balbianiales and Entwisleiales with Colaconematales was moderately supported. The Nemaliales, Entwisleiales, Colaconematales, Palmariales and Acrochaetiales formed a highly supported clade. Unfortunately, all other relationships among the orders had low bootstrap support. Although the ML analysis did not resolve many of the relationships, further analyses suggested that a resolution is possible. A Phycas analysis supported a dichotomously branching tree and Bayesian analysis showed a similar topology with all relationships highly supported. Simulations extrapolating the number of nucleotide characters beyond the current size of the dataset suggested that most nodes in the phylogeny would be resolved if more data become available. Phylogenomic approaches will be necessary to provide a well-supported phylogeny of this subclass with all relationships resolved such that the evolution of freshwater species from marine ancestors as well as reproductive traits can be explored.

  4. Uncovering Adiponectin Replenishing Property of Sujiaonori Algal Biomaterial in Humans

    Science.gov (United States)

    Ngatu, Nlandu Roger; Ikeda, Mitsunori; Watanabe, Hiroyuki; Tanaka, Mamoru; Inoue, Masataka; Kanbara, Sakiko; Nojima, Sayumi

    2017-01-01

    The replenishment of adiponectin—an adipocyte-derived hormone with salutary health effects—has recently been proposed as a new approach to treat hypertension, also ameliorate cardiovascular and metabolic risks. We conducted a prospective placebo-controlled, non-randomized and investigator-blinded dietary intervention study to evaluate the health effects of dietary intake of Sujiaonori (Ulva/Enteromorpha prolifera Müller) algal biomaterial (SBM), especially on adiponectin production, blood pressure (BP), and body mass index (BMI) in human subjects. Participants (N = 32) were divided into two equally sized groups (n = 16 for each group): SBM group (subjects supplemented with 3 g SBM powder twice a day during meal) and the control group (subjects who took 3 g of a supplement made of 70% corn starch powder and 30% spinach twice a day) for four weeks. Two health survey questionnaires (dietary and current health questionnaires) were completed anonymously, saliva sampling was done for adiponectin measurement by ELISA, and blood pressure (BP) and anthropometric parameters were measured at baseline and four weeks later. Student paired t-test was performed to compare baseline and post-intervention data on outcome variables between the two study groups. Results showed a 2.24-fold increase in adiponectin level in SBM group (2.81 and 6.26 ng/mL at baseline and at the end of study, respectively) (p 0.05). In SBM subjects, an improvement of BP profile was noted with a significant decrease in systolic BP (p < 0.01). A positive correlation was found between SBM supplementation and adiponectin level, whereas an inverse correlation was noted between SBM supplementation and blood pressure, and also BMI. These findings suggest that SBM-increased adiponectin level and improved BP in a sample of Japanese young adults, and has the potential to improve blood pressure in humans. PMID:28208744

  5. Modeling of polymer brush grafted nanoparticles for algal harvesting

    Science.gov (United States)

    Goins, Jason

    Microalgae derived biofuel shows great potential as a replacement to petroleum based fuels. However, industrial scale and economical production of fuel from microalgae suffer from an expensive dewatering step brought on by the organism's specific cell properties. A retrievable, paramagnetic nanoparticle polyelectrolyte brush (NPPB) has been designed as a flocculation agent to provide a low cost method in collecting algal biomass in biofuel production. In conjunction with experiment, subsequent theoretical investigations have been conducted in order to understand experimental observations and inform future design. A strategy has been implemented to provide informative descriptions for the relationship between flocculation agent parameters and dewatering efficiency. We studied the effect altering the degree of polymerization and monomer charge fraction had on the harvesting efficiency by considering flocculation as the criteria for harvesting. As the number of charges on the polymer backbone of the NPPB is increased, less NPPB concentrations are required to achieve equal harvesting efficiencies. This is a result of needing less NPPB to completely screen the effective charge on the algae surface. However, the Debye length limits the amount of charge on the algae surface one NPPB can screen. Using the free energy calculations for the complete set of pair interactions between the NPPB and the algae, we determined how many adsorbed NPPB were required in order for the force between coated algae to become attractive at some algae surface separation. This corresponded to the NPPB bridging two algae surfaces. NPPB with higher monomer charge fractions and degree of polymerizations led to a stronger bridging bond and larger bridging gap that could outweigh the algae pair repulsion. Optimized structures maximize these effects.

  6. Integrative Indicator for Assessing the Alert Levels of Algal Bloom in Lakes: Lake Taihu as a Case Study

    Science.gov (United States)

    Li, Qinqin; Hu, Weiping; Zhai, Shuhua

    2016-01-01

    Algal blooms have recently become one of the most serious environmental problems in eutrophic freshwater ecosystems worldwide. Although many observation and simulation approaches have been applied to predict algal blooms, few studies have addressed the alert levels of algal blooms using integrative indicators in a large lake with multiple service function and significant horizontal heterogeneity. This study developed an integrative indicator assessment system (IIAS) to rank the alert level of algal blooms. In the IIAS, algal biomass, area percentage, distance from drinking water intake points, distance from scenic zones and duration of algal bloom were used as indicators to calculate a comprehensive alert level, which was classified into five grades (Vigilance, Low, Moderate, High, and Severe). Lake Taihu was taken as a case study to assess the comprehensive alert level of algal blooms in 2007 and 2010. The comprehensive alert level showed obvious spatial-temporal patterns, with an acceptable accuracy in Lake Taihu. The comprehensive alert levels were relatively higher in typical phytoplankton subzones than typical hydrophytes subzones and are more sensitive to weight factor in the northern and western subzones where high biomass usually occurs. Case study showed a very good application of the proposed comprehensive alert level assessment methodology, which can be adjusted to predict the degree of hazard of algal blooms in multi-service function large lakes to help the government and decision makers to act to prevent the disaster from algal bloom spreading.

  7. Growing hairs in shorn cattle

    Directory of Open Access Journals (Sweden)

    Cecília José Veríssimo

    2013-12-01

    Full Text Available The shearing operation can provide double benefits to the cattle: they can become more heat tolerant and the tick infestation decreases. The cattle tick Rhipicephalus (Boophilus microplus causes great losses to dairy cattle, especially to the Holstein cattle because they are very susceptible to this tick. Its control is becoming each day more difficult, owing to the increasing resistance to acaricides they are acquiring. The objective of this work was to study the growing of haircoat following shearing. We made our experiment with 17 animals, 7 females and 10 males. They were shaved on the anterior third (head, neck, dewlap, scapula and arm of one side, at random. The work was performed in two steps: they were shorn for the first time on August 2nd 2012, with a size 10 blade in a clipper Oster model GoldenA5, which left the fur coat 2 mm long. Then we evaluated the hair length growing by collecting fortnightly three sample of hairs in the middle of the scapula, with  electric pliers, modified for this purpose, in both sides of the animals, sheared and non-sheared, until 30 days after this shearing. The three hair samples were put inside a little plastic bag per animal. Meanwhile, as we thought that the animals shearing had to be done closer to the skin, we decided to shear them again (in the same side shorn before, on October 2nd 2012. We changed our procedure using the same machine, but now with a blade size 30, which left the fur coat 1mm thick. After that, we collected again, fortnightly, samples of hairs on both sides during 2 months. The 10 longest hairs in the plastig bag were measured using a graph paper and the average per animal was calculated in each data and blade. A random design was applied for statistical analysis, the hair length of both sides, sheared and non sheared were compared by a two related samples tests – Wilcoxon, in a non parametric test, using the SPSSP 12.0 program, in each data within each blade. Using blade size

  8. Access to capital--a growing concern.

    Science.gov (United States)

    Carlson, Donald A

    2004-01-01

    Access to capital over the next ten years will be one of the biggest challenges healthcare organizations will face as they strive to remain competitive and serve their communities. Meeting the growing needs for capital will require a disciplined and honest assessment of the capital sources that will be available and the best ways of positioning an organization to maximize their uses. It is incumbent on chief executive officers and other senior leaders to create a disciplined process for allocating capital and conveying how that process will be linked to the organization's strategic plan. All of the credit constituencies "buying" healthcare need to fully understand how the organization is positioning itself for future growth and success, and detailed bond marketing plans need to be implemented well before the actual sale of a new bond issue. Large and small healthcare providers will have sufficient access to capital in the future if investors believe that senior hospital executives have a credible plan and are disciplined enough to execute it.

  9. Growth limitation of three Arctic sea ice algal species

    DEFF Research Database (Denmark)

    Sogaard, D.H.; Hansen, P.J.; Rysgaard, Søren;

    2011-01-01

    results suggest that the chlorophyte and the two diatoms have different tolerance to fluctuations in salinity and pH. The two species of diatoms exhibited maximum growth rates at a salinity of 33, and growth rates at a salinity of 100 were reduced by 50% compared to at a salinity of 33. Growth ceased...... at a salinity of 150. The chlorophyte species was more sensitive to high salinities than the two diatom species. Growth rate of the chlorophyte was greatly reduced already at a salinity of 50 and it could not grow at salinities above 100. At salinity 33 and constant TCO(2) concentration, all species exhibited...... maximal growth rate at pH 8.0 and/or 8.5. The two diatom species stopped growing at pH > 9.5, while the chlorophyte species still was able to grow at a rate which was 1/3 of its maximum growth rate at pH 10. Thus, Chlamydomonas sp. was able to grow at high pH levels in the succession experiment...

  10. [Growing old differently: Transdisciplinary perspective].

    Science.gov (United States)

    Zimmermann, H-P

    2015-04-01

    Growing old differently: the phrase is intended to call something other to mind than merely the fact that images and forms of old age and aging have multiplied and diversified to an enormous extent. The suggestion put forward here is that otherness (as opposed to mere differences) should be positively reinforced. In other words, it is not just a matter of noting different forms of old age and aging but more than this, of seeking out opportunities for aging differently. In order to explore this, the article follows an older strand of theory, which has recently come to be frequently quoted in gerontology: the phenomenology of difference as reasoned analytically by Lévinas and Sartre and applied to gerontology by Améry and de Beauvoir. Here, opportunities for aging crucially depend on the way we look at it, how we observe and describe it and not least, how gerontology frames it. A distinction is made between two perspectives and their associated consequences for old age: alienation and alterity. Alienation means looking at old age above all as a disconcerting "other", as a perplexing, problematic deviation from the norm of vitality. Alterity, by contrast, refers to different options for living life in old age: options to be explored and opened up in contradistinction to cultural or academic alienation. Not least, the article appeals for diversity in scholarly approaches and for cross-disciplinary perspectives.

  11. Case grows for climate change

    Energy Technology Data Exchange (ETDEWEB)

    Hileman, B.

    1999-08-09

    In the four years since the IPCC stated that 'the balance of evidence suggests a discernible human influence on global climate', evidence for anomalous warming has become more compelling, and as a result scientists have become more concerned that human-induced climate change has already arrived. The article summarises recent extra evidence on global temperatures, carbon dioxide measurements, ice shelf breakup, coral bleaching, unstable climates and improved climate models. At the time of the Kyoto conference, the US became keen on the idea that enhancing forest and soil carbon sequestration was a good way to offset emissions reduction targets. Congress is however under the opinion on that the Kyoto protocol presents a threat to the US economy, and senate is very unlikely to ratify the protocol during the Clinton Administration. The debate as to whether the US government should mandate major emission reduction or wait for more scientific certainty may continue for a number of years, but, growing concern of scientists and the public for the harmful effects of climate change may cause a change. 4 figs., 8 photos.

  12. Growing plants on atoll soils

    Energy Technology Data Exchange (ETDEWEB)

    Stone, E L; Migvar, L; Robison, W L

    2000-02-16

    Many years ago people living on atolls depended entirely on foods gathered from the sea and reefs and grown on land. Only a few plants, such as coconut (ni), Pandanus (bob), and arrowroot (mok-mok), could be grown on the lower rainfall atolls, although adequate groundwater conditions also allowed taro (iaraj, kotak, wot) to be cultivated. On higher rainfall atolls, breadfruit (ma) was a major food source, and banana (binana, kepran), lime (laim), and taros (iaraj, kotak, wot) could be grown. The early atoll populations were experts in growing plants that were vital to sustaining their nutrition requirements and to providing materials for thatch, basketry, cordage, canoe construction, flowers, and medicine. They knew which varieties of food plants grew well or poorly on their atolls, how to propagate them, and where on their atoll they grew best. They knew the uses of most native plants and what the various woods were well suited for. Many varieties of Pandanus (bob) and breadfruit (ma) grew well with high rainfall, but only a few produced well on drier atolls. Such information had been passed down through the generations although some of it has been lost in the last century. Today there are new plants and new varieties of existing plants that can be grown on atolls. There are also new materials and information on how to grow both the old and new plants more effectively. However, there are also introduced weeds and pests to control. Today, there is also an acute need to grow more of the useful plants adapted to atolls. Increasing numbers of people living on an atoll without an equal increase in income or food production stretches the available food supplies. Much has been written about the poor conditions for plant growth on atolls. As compared with many places in the world where crops are grown, however, atolls can provide some highly favorable conditions. For instance, the driving force for plant growth is sunlight, and on atolls light is abundant throughout the

  13. Esophageal malignancy: A growing concern

    Institute of Scientific and Technical Information of China (English)

    Jianyuan Chai; M Mazen Jamal

    2012-01-01

    Esophageal cancer is mainly found in Asia and east Africa and is one of the deadliest cancers in the world.However,it has not garnered much attention in the Western world due to its low incidence rate.An increasing amount of data indicate that esophageal cancer,particularly esophageal adenocarcinoma,has been rising by 6-fold annually and is now becoming the fastest growing cancer in the United States.This rise has been associated with the increase of the obese population,as abdominal fat puts extra pressure on the stomach and causes gastroesophageal reflux disease (GERD).Long standing GERD can induce esophagitis and metaplasia and,ultimately,leads to adenocarcinoma.Acid suppression has been the main strategy to treat GERD; however,it has not been proven to control esophageal malignancy effectively.In fact,its side effects have triggered multiple warnings from regulatory agencies.The high mortality and fast growth of esophageal cancer demand more vigorous efforts to look into its deeper mechanisms and come up with better therapeutic options.

  14. Cryosurgical effects on growing vessels.

    Science.gov (United States)

    Ladd, A P; Rescorla, F J; Baust, J G; Callahan, M; Davis, M; Grosfeld, J L

    1999-07-01

    Cryosurgical treatment of unresectable hepatic malignancies has proven beneficial in adults. Concerns regarding its use in children include the effect on growth and the risk of injury to adjacent structures. To test the effect of cryoablation on adjacent vascular structures in a growing animal, liquid nitrogen cryoablation was performed on a juvenile murine model. Sprague Dawley rats underwent double freeze-thaw cryoablation of the abdominal aorta with interposed liver tissue. Serial sacrifices were performed over 120 days. Comparisons were made with sham-operated controls. Overall, animal growth paralleled that of sham controls through all time points. Gross examination of aortic diameter also showed similar growth in vessel size between the groups. Histologic analysis demonstrated injury after cryoablation with smooth muscle cell vacuolization, followed by cell death. Aortic media layer collapse resulted from cellular loss, however, elastin fiber composition was maintained. Aortic patency was preserved despite evidence of cellular injury and aortic wall remodeling. An associated thermal sink effect on the opposing wall was identified. After cryoablation adjacent to the abdominal aorta in adolescent rats, vascular patency is maintained and animal growth and structural function is preserved, despite cellular injury and wall compression. These observations suggest that cryoablation may be a useful treatment adjunct in young subjects.

  15. Algal massive growth in relation to water quality and salinity at Damietta, north of Egypt

    Directory of Open Access Journals (Sweden)

    Mohamed Ali Ibraheem Deyab

    2015-02-01

    Full Text Available Objective: To relate the proliferation and dominance of certain algal species at the Damietta and its relation to water quality. Methods: Water and algal biomass were bimonthly sampled from five selected sites at Damietta Province, Egypt during 2012. Algae were identified and quantified. Waters, algae and sediment were analyzed. Results: The physicochemical properties of water showed limited seasonal but substantial local variation. The high levels of nitrogen and phosphorus and turbidity of water pointed to marked eutrophication, which could enhance massive algal growth. The temporal fluctuation in temperature, exposure to industrial and domestic sewage and salinity results in succession between blooming algal species. Spirulina platensis and Chlorella vulgaris alternated in a moderately saline water and Oscillatoria agardhii and Mougeotia scalaris in a fresh water body during summer and winter respectively. Likewise, Microcystis aureginosa and Ulva lactuca alternated in a moderately saline site during autumn and summer respectively. Cladophora albida dominated a fish pond of brackish water and Dunaliella salina dominated the most saline water over the whole period of study. Conclusions: Growth of the predominant algal species is correlated to water quality. These species are of considerable nutritive value, with moderate contents of protein, carbohydrate, macronutrients and micronutrients, which evaluates them for usage as food (green and macroalgae, fodder or bio-fertilizer (cyanophytes.

  16. Utilization of rural wastes for algal biomass production with Scenedesmus acutus and Spirulina platensis in India

    Energy Technology Data Exchange (ETDEWEB)

    Venkataraman, L.V.; Devi, K.M.; Mahadevaswamy, M.; Mohammed Kunhi, A.A.

    1982-03-01

    A technology for the production of the green alga, Scenedesmus acutus, and blue-green alga, Spirulina platensis, in clean water has been developed to suit Indian conditions. Experience gained on algal production technology in India indicates the scope for applying this at the rural level for use in the production of animal feed. Spirulina is the most promising alga in view of its amenability to low level technology. Nutrient input to the cultures is one of the most expensive steps. It is shown that agricultural and domestic wastes can be effectively recycled for algal biomass production by replacing, at least partly, the nutrient inputs. Urine and bonemeal reduce the inputs of nitrate, calcium and phosphate salts into the culture medium. Sheep's blood has a growth promoting effect on algal cultures and a good potential for application. Carbon dioxide enriched air-'aerobic biogas'-produced by composting cow dung, can be used as a carbon source for algal cultivation. Several experiments carried out in India indicate the possibility of developing an integrated algal production system in rural areas by means of which wastes can be effectively recycled. The use of algae in poultry and fish feeds is a distinct possibility for the future. (Refs. 25).

  17. Highly-efficient enzymatic conversion of crude algal oils into biodiesel.

    Science.gov (United States)

    Wang, Yao; Liu, Jin; Gerken, Henri; Zhang, Chengwu; Hu, Qiang; Li, Yantao

    2014-11-01

    Energy-intensive chemical conversion of crude algal oils into biodiesel is a major barrier for cost-effective algal biofuel production. To overcome this problem, we developed an enzyme-based platform for conversion of crude algal oils into fatty acid methyl esters. Crude algal oils were extracted from the oleaginous microalga Nannochloropsis oceanica IMET1 and converted by an immobilized lipase from Candida antarctica. The effects of different acyl acceptors, t-butanol as a co-solvent, oil to t-butanol ratio, oil to methanol ratio, temperature and reaction time on biodiesel conversion efficiency were studied. The conversion efficiency reached 99.1% when the conversion conditions were optimized, i.e., an oil to t-butanol weight ratio of 1:1, an oil to methanol molar ratio of 1:12, and a reaction time of 4h at 25°C. The enzymatic conversion process developed in this study may hold a promise for low energy consumption, low wastewater-discharge biochemical conversion of algal feedstocks into biofuels.

  18. Growth and survival of endangered angelwing clam, Pholas orientalis fed different algal diets

    Directory of Open Access Journals (Sweden)

    M. Shirley M. Golez

    2011-12-01

    Full Text Available Mature angelwing clam, Pholas orientalis were collected from the wild and transported tothe laboratory for broodstock development. They were fed with mixed algal cultures of Isochrysisgalbana, Chaetoceros sp., and Tetraselmis sp. for a period of two months and a half to determine theeffects of these algal cultures on growth and survival of the broodstock. Growth in terms of length wasnot significantly different among the treatment groups, whereas, there was significant reduction in theweight of the clams in the group fed with a mixture of Isochrysis galbana, Chaetoceros sp., andTetraselmis sp. Survival of the clams decreased after two months of feeding with algal diets, withsignificant mortality observed in groups fed with a mixture of Isochrysis galbana and Tetraselmis sp. aswell as with the mixture of the three microalgae. All the water quality parameters in the rearing tankswere within the optimum levels required for optimum growth of the clams. These results showed thatmixed algal diets for broodstock development in angelwing clam have no direct effect on growth butmoderate effect on survival. Future studies are aimed towards determining other factors that willcontribute to better growth and survival of angelwing clam broodstock in captivity as well as for thesearch of alternative algal diets for angelwing broodstock, particularly by exploring the microalgae thatare found in their natural habitat.

  19. Algal massive growth in relation to water quality and salinity at Damietta, north of Egypt

    Institute of Scientific and Technical Information of China (English)

    Mohamed Ali Ibraheem Deyab; Taha Mohamed El-Katony

    2015-01-01

    Objective:To relate the proliferation and dominance of certain algal species at the Damietta and its relation to water quality. Methods: Water and algal biomass were bimonthly sampled from five selected sites at Damietta Province, Egypt during 2012. Algae were identified and quantified. Waters, algae and sediment were analyzed. Results:The physicochemical properties of water showed limited seasonal but substantial local variation. The high levels of nitrogen and phosphorus and turbidity of water pointed to marked eutrophication, which could enhance massive algal growth. The temporal fluctuation in temperature, exposure to industrial and domestic sewage and salinity results in succession between blooming algal species. Spirulina platensis and Chlorella vulgaris alternated in a moderately saline water and Oscillatoria agardhii and Mougeotia scalaris in a fresh water body during summer and winter respectively. Likewise, Microcystis aureginosa and Ulva lactuca alternated in a moderately saline site during autumn and summer respectively. Cladophora albida dominated a fish pond of brackish water and Dunaliella salina dominated the most saline water over the whole period of study. Conclusions:Growth of the predominant algal species is correlated to water quality. These species are of considerable nutritive value, with moderate contents of protein, carbohydrate, macronutrients and micronutrients, which evaluates them for usage as food (green and macroalgae), fodder or bio-fertilizer (cyanophytes).

  20. Algal control and enhanced removal in drinking waters in Cairo, Egypt.

    Science.gov (United States)

    El-Dars, Farida M S E; Abdel Rahman, M A M; Salem, Olfat M A; Abdel-Aal, El-Sayed A

    2015-12-01

    Algal blooms at the major water treatment plants in Egypt have been reported since 2006. While previous studies focused on algal types and their correlation with disinfection by-products, correlation between raw water quality and algal blooms were not explored. Therefore, a survey of Nile water quality parameters at a major water intake in the Greater Cairo Urban Region was conducted from December 2011 to November 2012. Bench-scale experiments were conducted to evaluate the effectiveness of the conventional chloride/alum treatment compared with combined Cl/permanganate pre-oxidation with Al and Fe coagulants during the outbreak period. Addition of permanganate (0.5 mg/L) significantly reduced the chlorine demand from 5.5 to 2.7 mg/L. The applied alum coagulant dose was slightly reduced while residual Al was reduced by 27% and the algal count by 50% in the final treated waters. Applying ferric chloride and ferric sulfate as coagulants to waters treated with the combined pre-oxidation procedure effectively reduced algal count by 60% and better the total organic carbon reduction and residual aluminum in the treated water. Multivariate statistical analysis was used to identify the relationship between water quality parameters and occurrence of algae and to explain the impact of coagulants on the final water quality.

  1. Strong fungal specificity and selectivity for algal symbionts in Florida scrub Cladonia lichens.

    Science.gov (United States)

    Yahr, Rebecca; Vilgalys, Rytas; Depriest, Paula T

    2004-11-01

    Symbiosis is a major theme in the history of life and can be an important force driving evolution. However, across symbioses, it is difficult to tease apart the mechanisms that structure the interactions among potential partners. We used genetic similarity and frequency-based methods to qualitatively and quantitatively examine the patterns of association among several co-occurring Cladonia lichen fungi and their algal photobionts in six disjunct Florida scrub sites. The patterns of association were described by the degree of specificity, i.e. the phylogenetic range of associated partners, and of selectivity, i.e. the frequency of association among partners. Six fungal species associated with only one algal internal transcribed spacer clade, with the remaining two fungi being associated with two algal clades. In all cases, the fungi associated in unequal frequencies with the observed algal photobiont genotypes within those clades--suggesting that both specificity and selectivity were higher than expected. Fungal species can be grouped into three significantly different specificity classes: photobiont specialists, intermediates and generalists. In contrast to the pronounced specificity for photobionts among fungal species, the different Florida scrub sites do not harbour distinct photobiont pools, and differential photobiont availability cannot explain the patterning of lichen associations at this spatial scale. Therefore, we conclude that fungal specificity and selectivity for algal photobionts are major factors in determining the local composition of symbiotic partnerships.

  2. Removal of Zn(II) from simulated wastewater using an algal biofilm.

    Science.gov (United States)

    Liu, Cuixia; Hu, Zhiquan; Zuo, Jiaolan; Hu, Mian; Xiao, Bo

    2014-01-01

    An algal biofilm was employed as a novel kind of adsorbing material to remove Zn(II) from simulated wastewater. The algal biofilm system formed by Oedogonium sp. was operated in a dynamic mode for a period of 14 days with an initial Zn(II) concentration of 10 mg/L. The average effluent Zn(II) concentration was 0.247 mg/L and the average removal efficiency reached 97.7%. The effects of Zn(II) on key algal physiological and biochemical indices such as chlorophyll content, nitrate reductase and superoxide dismutase activity, extracellular polysaccharides (EPS), and soluble protein levels were studied. Our results showed that the algal biofilm could adapt to the simulated wastewater containing Zn(II). Scanning electron microscope and Fourier transform infrared spectroscopy analyses of algal biofilm revealed the presence of carboxyl, amino, and sulphonate groups, which were the main functional groups of EPS and proteins, and these were likely responsible for biosorption of the Zn(II) ions.

  3. Menopausal women's positive experience of growing older

    DEFF Research Database (Denmark)

    Hvas, Lotte

    2006-01-01

    This paper aims to describe menopausal women's positive experience of growing older and becoming middle-aged.......This paper aims to describe menopausal women's positive experience of growing older and becoming middle-aged....

  4. Discordant coral-symbiont structuring: factors shaping geographical variation of Symbiodinium communities in a facultative zooxanthellate coral genus, Oculina

    Science.gov (United States)

    Leydet, Karine Posbic; Hellberg, Michael E.

    2016-06-01

    Understanding the factors that help shape the association between corals and their algal symbionts, zooxanthellae ( Symbiodinium), is necessary to better understand the functional diversity and acclimatization potential of the coral host. However, most studies focus on tropical zooxanthellate corals and their obligate algal symbionts, thus limiting our full comprehension of coral-algal symbiont associations. Here, we examine algal associations in a facultative zooxanthellate coral. We survey the Symbiodinium communities associated with Oculina corals in the western North Atlantic and the Mediterranean using one clade-level marker ( psbA coding region) and three fine-scale markers ( cp23S- rDNA, b7sym15 flanking region, and b2sym17). We ask whether Oculina spp. harbor geographically different Symbiodinium communities across their geographic range and, if so, whether the host's genetics or habitat differences are correlated with this geographical variation. We found that Oculina corals harbor different Symbiodinium communities across their geographical range. Of the habitat differences (including chlorophyll a concentration and depth), sea surface temperature is better correlated with this geographical variation than the host's genetics, a pattern most evident in the Mediterranean. Our results suggest that although facultative zooxanthellate corals may be less dependent on their algal partners compared to obligate zooxanthellate corals, the Symbiodinium communities that they harbor may nevertheless reflect acclimatization to environmental variation among habitats.

  5. Investigating the feasibility of growing algae for fuel in Southern nevada

    Science.gov (United States)

    Moazeni, Faegheh

    Microalgae capable of growing in waste are adequate to be mass-cultivated for biodiesel, avoiding fertilizers and clean water, two obstacles to sustainability of the feedstock production. This study replaces fertilizers and clean water with waste products. The investigated wastes include (1) the liquid fraction of sewage after solids and particles are removed, known as centrate, and (2) algal biomass residue, i.e. the algae remaining at the end of the lipids extraction process at biofuel plants. These wastes contain sufficient amount of nitrogen and phosphorus required for algal growth. This study proposes a system in which centrate would be used as an initial source of water and nutrients for microalgal growth. The generated biomass waste can be continuously recycled, serving as a fertilizer. If so desired, the centrate can be reverted back into the system from time to time as a nutrition supplement and as a make-up water source, particularly in open ponds that face evaporation. Of the six studied algae, i.e. Chlorella sorokiniana, Encyonema caespitosum, Nitzschia thermalis, Scenedesmus sp., Synechocystis sp., and Limnothrix sp., mostly isolated from the habitats influenced by municipal wastewater in and around the Las Vegas Valley, two green algae were eligible. In the laboratory, the green algae C. sorokiniana and Scenedesmus sp. grew in the media composed of centrate or algal residue faster than in the mineral medium BG11, optimized for algal growth. The enhanced productivity is mainly attributed to the photosynthesis known for mixotrophic process and the presence of organic carbon in the waste which serves as an extra source of energy. Tolerance for hard water and strong light and, in the case of C. sorokiniana , an unusually high optimum temperature between 32 and 35°C are also attributing factors to the enhanced productivity of algae. These studied species are particularly suited for cultivation in their native southwestern United States, particularly

  6. Algal endosymbiosis in brown hydra: host/symbiont specificity.

    Science.gov (United States)

    Rahat, M; Reich, V

    1986-12-01

    Host/symbiont specificity has been investigated in non-symbiotic and aposymbiotic brown and green hydra infected with various free-living and symbiotic species and strains of Chlorella and Chlorococcum. Morphology and ultrastructure of the symbioses obtained have been compared. Aposymbiotic Swiss Hydra viridis and Japanese H. magnipapillata served as controls. In two strains of H. attenuata stable hereditary symbioses were obtained with Chlorococcum isolated from H. magnipapillata. In one strain of H. vulgaris, in H. oligactis and in aposymbiotic H. viridis chlorococci persisted for more than a week. Eight species of free-living Chlorococcum, 10 symbiotic and 10 free-living strains of Chlorella disappeared from the brown hydra within 1-2 days. In H. magnipapillata there was a graded distribution of chlorococci along the polyps. In hypostomal cells there were greater than 30 algae/cell while in endodermal cells of the mid-section or peduncle less than 10 algae/cell were found. In H. attenuata the algal distribution was irregular, there were up to five chlorocci/cell, and up to 20 cells/hydra hosted algae. In the dark most cells of Chlorococcum disappeared from H. magnipapillata and aposymbiotic hydra were obtained. Chlorococcum is thus an obligate phototroph, and host-dependent heterotrophy is not required for the preservation of a symbiosis. The few chlorococci that survived in the dark seem to belong to a less-demanding physiological strain. In variance with known Chlorella/H. viridis endosymbioses the chlorococci in H. magnipapillata and H. attenuata were tightly enveloped in the vacuolar membrane of the hosting cells with no visible perialgal space. Chlorococcum reproduced in these vacuoles and up to eight daughter cells were found within the same vacuole. We suggest that the graded or scant distribution of chlorococci in the various brown hydra, their inability to live in H. viridis and the inability of the various chlorellae to live in brown hydra are the

  7. Comparative use of bacterial, algal and protozoan tests to study toxicity of azo- and anthraquinone dyes.

    Science.gov (United States)

    Novotný, Cenek; Dias, Nicolina; Kapanen, Anu; Malachová, Katerina; Vándrovcová, Marta; Itävaara, Merja; Lima, Nelson

    2006-06-01

    Toxicity of two azo dyes (Reactive Orange 16 (RO16); Congo Red (CR)) and two anthraquinone dyes (Remazol Brilliant Blue R (RBBR); Disperse Blue 3 (DB3)) were compared using bacterium Vibrio fischeri, microalga Selenastrum capricornutum and ciliate Tetrahymena pyriformis. The following respective endpoints were involved: acute toxicity measured as bacterial luminescence inhibition, algal growth inhibition, and the effects on the protozoa including viability, growth inhibition, grazing effect and morphometric effects. In addition, mutagenicity of the dyes was determined using Ames test with bacterium Salmonella typhimurium His(-). DB3 dye was the most toxic of all dyes in the bacterial, algal and protozoan tests. In contrast to other dyes, DB3 exhibited mutagenic effects after metabolic activation in vitro in all S. typhimurium strains used. Of the methods applied, the algal test was the most sensitive to evaluate toxicity of the dyes tested.

  8. Characteristic time scales of mixing, mass transfer and biomass growth in a Taylor vortex algal photobioreactor.

    Science.gov (United States)

    Gao, Xi; Kong, Bo; Vigil, R Dennis

    2015-12-01

    Recently it has been demonstrated that algal biomass yield can be enhanced using fluid flow patterns known as Taylor vortices. It has been suggested that these growth rate improvements can be attributed to improved light delivery as a result of rapid transport of microorganisms between light and dark regions of the reactor. However, Taylor vortices also strongly impact fluid mixing and interphase (gas-liquid) mass transport, and these in turn may also explain improvements in biomass productivity. To identify the growth-limiting factor in a Taylor vortex algal photobioreactor, experiments were performed to determine characteristic time scales for mixing and mass transfer. By comparing these results with the characteristic time scale for biomass growth, it is shown that algal growth rate in Taylor vortex reactors is not limited by fluid mixing or interphase mass transfer, and therefore the observed biomass productivity improvements are likely attributable to improved light utilization efficiency.

  9. Intensified nitrogen removal of constructed wetland by novel integration of high rate algal pond biotechnology.

    Science.gov (United States)

    Ding, Yi; Wang, Wei; Liu, Xingpo; Song, Xinshan; Wang, Yuhui; Ullman, Jeffrey L

    2016-11-01

    High rate algal pond (HRAP) was combined with constructed wetland (CW) to intensify nitrogen removal through optimizing nitrification and denitrification. Nitrification and denitrification process mainly depends on the oxygen content and carbon source level in CWs. Algal biomass was enriched in HRAP, and dissolved oxygen (DO) concentration was increased via photosynthesis. Algal debris increased COD as degradable bioresource. The results showed that HRAP-CW hybrid systems effectively promoted the nitrogen removal performance due to rich DO and COD. The extension of hydraulic retention time in HRAP significantly improved NH4-N and TN removals by 10.9% and 11.1% in hybrid systems, respectively. The highest NH4-N and TN removals in hybrid systems respectively reached 67.2% and 63.5%, which were significantly higher than those in single CW. The study suggested that the hybrid system had the application potentials in nitrogen removal from wastewater.

  10. Sustainable treatment potential of mixed algal consortia for domestic waste water: Growth and mixotrophy

    Directory of Open Access Journals (Sweden)

    Priyanka Murthy

    2015-04-01

    Full Text Available The increasing levels of generation of nutrient-rich waste water pose serious challenge. Conventional biological and chemical methods of waste water treatment have failed in meeting sustainability challenges. Naturally occurring mixed algal species reared in mixotrophic growth modes have been deployed to recover nutrients (N and P from domestic wastewater after anaerobic digestion. In this paper, we present the results pertaining to growth and mixotrophy. Pilot-scale operation shows that the cultivation methods adopted and the use of naturally selected species lead to a tendency among these species to clump at certain stages of growth that in turn float or settle rapidly making algal harvest and thereby the nutrient recovery processes energy efficient. The highest settling rate was found to be 6.37 ± 1.6 g/m2/d. Mixotrophy was seen to contribute 15 – 24 % across the various algal consortia in wastewater (polyculture.

  11. Flore algale du Rhin canalisé : données récentes

    Directory of Open Access Journals (Sweden)

    PIERRE J. F.

    1996-04-01

    Full Text Available La communauté algale de trois stations du Rhin canalisé (Grand canal d'Alsace, au niveau du Centre de Production Nucléaire de Fessenheim, fait l'objet d'un suivi depuis 1977. Les présents résultats concernent la période 1988-1995. Ils mettent en évidence une stabilité de la flore algale au niveau de la diversité spécifique et de la répartition des espèces dominantes. L'inventaire diatomique s'enrichit d'une trentaine de taxons inédits pour ces stations. Ces données récentes confirment, au niveau de la communauté algale, l'absence d'impact visible du C R N . de Fessenheim.

  12. Simulation of photosynthetically active radiation distribution in algal photobioreactors using a multidimensional spectral radiation model.

    Science.gov (United States)

    Kong, Bo; Vigil, R Dennis

    2014-04-01

    A numerical method for simulating the spectral light distribution in algal photobioreactors is developed by adapting the discrete ordinate method for solving the radiative transport equation. The technique, which was developed for two and three spatial dimensions, provides a detailed accounting for light absorption and scattering by algae in the culture medium. In particular, the optical properties of the algal cells and the radiative properties of the turbid culture medium were calculated using a method based on Mie theory and that makes use of information concerning algal pigmentation, shape, and size distribution. The model was validated using a small cylindrical bioreactor, and subsequently simulations were carried out for an annular photobioreactor configuration. It is shown that even in this relatively simple geometry, nontrivial photon flux distributions arise that cannot be predicted by one-dimensional models.

  13. Addressing the challenges for sustainable production of algal biofuels: II. Harvesting and conversion to biofuels.

    Science.gov (United States)

    Abdelaziz, Ahmed E M; Leite, Gustavo B; Hallenbeck, Patrick C

    2013-01-01

    In order to ensure the sustainability of algal biofuel production, a number of issues need to be addressed. Previously, we reviewed some of the questions in this area involving algal species and the important challenges of nutrient supply and how these might be met. Here, we take up issues involving harvesting and the conversion ofbiomass to biofuels. Advances in both these areas are required if these third-generation fuels are to have a sufficiently high net energy ratio and a sustainable footprint. A variety of harvesting technologies are under investigation and recent studies in this area are presented and discussed. A number of different energy uses are available for algal biomass, each with their own advantages as well as challenges in terms of efficiencies and yields. Recent advances in these areas are presented and some of the especially promising conversion processes are highlighted.

  14. Is Occurrence of Harmful Algal Blooms in the Exclusive Economic Zone of India on the Rise?

    Directory of Open Access Journals (Sweden)

    K. B. Padmakumar

    2012-01-01

    Full Text Available Occurrence, increase in frequency, intensity and spatial coverage of harmful algal blooms during the past decade in the EEZ of India are documented here. Eighty algal blooms were recorded during the period 1998–2010. Of the eighty algal blooms, 31 blooms were formed by dinoflagellates, 27 by cyanobacteria, and 18 by diatoms. Three raphidophyte and one haptophyte blooms were also observed. Potentially toxic microalgae recorded from the Indian waters were Alexandrium spp., Gymnodinium spp. Dinophysis spp., Coolia monotis, Prorocentrum lima, and Pseudo-nitzschia spp. Examination of available data from the literature during the last hundred years and in situ observations during 1998–2010 indicates clear-cut increase in the occurrence of HABs in the Indian EEZ.

  15. The engine of the reef: Photobiology of the coral-algal symbiosis

    Directory of Open Access Journals (Sweden)

    Melissa Susan Roth

    2014-08-01

    Full Text Available Coral reef ecosystems thrive in tropical oligotrophic oceans because of the relationship between corals and endosymbiotic dinoflagellate algae called Symbiodinium. Symbiodinium convert sunlight and carbon dioxide into organic carbon and oxygen to fuel coral growth and calcification, creating habitat for these diverse and productive ecosystems. Light is thus a key regulating factor shaping the productivity, physiology and ecology of the coral holobiont. Similar to all oxygenic photoautotrophs, Symbiodinium must safely harvest sunlight for photosynthesis and dissipate excess energy to prevent oxidative stress. Oxidative stress is caused by environmental stressors such as those associated with global climate change, and ultimately leads to breakdown of the coral-algal symbiosis known as coral bleaching. Recently, large-scale coral bleaching events have become pervasive and frequent threatening and endangering coral reefs. Because the coral-algal symbiosis is the biological engine producing the reef, the future of coral reef ecosystems depends on the ecophysiology of the symbiosis. This review examines the photobiology of the coral-algal symbiosis with particular focus on the photophysiological responses and timescales of corals and Symbiodinium. Additionally, this review summarizes the light environment and its dynamics, the vulnerability of the symbiosis to oxidative stress, the abiotic and biotic factors influencing photosynthesis, the diversity of the coral-algal symbiosis and recent advances in the field. Studies integrating physiology with the developing omics fields will provide new insights into the coral-algal symbiosis. Greater physiological and ecological understanding of the coral-algal symbiosis is needed for protection and conservation of coral reefs.

  16. Transformation of algal turf by echinoids and scarid fishes on French Polynesian coral reefs

    Science.gov (United States)

    Harmelin-Vivien, Mireille L.; Peyrot-Clausade, Mireille; Romano, Jean-Claude

    1992-04-01

    The respective roles of regular echinoids and scarid fishes in the transformation of turf algae, the main food resource for reef herbivores, were investigated on French Polynesian coral reefs. The role of one species of parrotfish ( Scarus sordidus) was compared with that of four species of echinoids. The degree and ways of degradation of the algal matter were determined by the organic matter percentage, the composition of the sugar fraction, and the concentration and composition of chlorophylltype pigments as assayed by HPLC analysis. Chemical analyses were performed on anterior and posterior intestines for scarids, intestinal contents and faeces for echinoids, and on fresh algal turf as a control of initial food quality. A decrease in mean percentage of organic matter in gut content was observed from intestine (9.7%) to faeces (7%) in sea urchins, but not in parrotfishes. The total sugar fraction decreased from fresh algal turf (32% of total organic matter) to echinoid (28%) to scarid (18%) gut contents. The ratio of insoluble to soluble sugars (I/S ratios) was higher in echinoids (2.6) than in scarid gut contents (1.0). A decrease in the total pigment concentration was measured from fresh algal turf to echinoid and it was found to be even lower in scarid gut contents. Chromatograms showed that the composition of chlorophyll-type pigments in scarid intestines was very similar to fresh algal turf, with a dominance of native forms, mainly chlorophyll a and b. On the contrary, degraded pigment forms dominated in echinoids. The main degraded products were pheophorbides in sea urchins, and chlorophyllides in parrotfishes. These results provided evidence for differentiation in digestive processes occurring in the two types of grazers. Echinoids released higher degraded algal material than did scarids. Thus, these two types of grazers play different roles in the recycling of organic matter on coral reefs.

  17. Characterisation of algal organic matter produced by bloom-forming marine and freshwater algae

    KAUST Repository

    Villacorte, Loreen O.

    2015-04-01

    Algal blooms can seriously affect the operation of water treatment processes including low pressure (micro- and ultra-filtration) and high pressure (nanofiltration and reverse osmosis) membranes mainly due to accumulation of algal-derived organic matter (AOM). In this study, the different components of AOM extracted from three common species of bloom-forming algae (Alexandrium tamarense, Chaetoceros affinis and Microcystis sp.) were characterised employing various analytical techniques, such as liquid chromatography - organic carbon detection, fluorescence spectroscopy, fourier transform infrared spectroscopy, alcian blue staining and lectin staining coupled with laser scanning microscopy to indentify its composition and force measurement using atomic force microscopy to measure its stickiness. Batch culture monitoring of the three algal species illustrated varying characteristics in terms of growth pattern, cell concentration and AOM release. The AOM produced by the three algal species comprised mainly biopolymers (e.g., polysaccharides and proteins) but some refractory compounds (e.g., humic-like substances) and other low molecular weight acid and neutral compounds were also found. Biopolymers containing fucose and sulphated functional groups were found in all AOM samples while the presence of other functional groups varied between different species. A large majority (>80%) of the acidic polysaccharide components (in terms of transparent exopolymer particles) were found in the colloidal size range (<0.4μm). The relative stickiness of AOM substantially varied between algal species and that the cohesion between AOM-coated surfaces was much stronger than the adhesion of AOM on AOM-free surfaces. Overall, the composition as well as the physico-chemical characteristics (e.g., stickiness) of AOM will likely dictate the severity of fouling in membrane systems during algal blooms.

  18. Cells growing in NASA Bioreactor

    Science.gov (United States)

    1998-01-01

    For 5 days on the STS-70 mission, a bioreactor cultivated human colon cancer cells, which grew to 30 times the volume of control specimens grown on Earth. This significant result was reproduced on STS-85 which grew mature structures that more closely match what are found in tumors in humans. Shown here, clusters of cells slowly spin inside a bioreactor. On Earth, the cells continually fall through the buffer medium and never hit bottom. In space, they are naturally suspended. Rotation ensures gentle stirring so waste is removed and fresh nutrient and oxygen are supplied. The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The Bioreactor is rotated to provide gentle mixing of fresh and spent nutrient without inducing shear forces that would damage the cells. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators.

  19. MBTH: A novel approach to rapid, spectrophotometric quantitation of total algal carbohydrates

    Energy Technology Data Exchange (ETDEWEB)

    Van Wychen, Stefanie; Long, William; Black, Stuart K.; Laurens, Lieve M. L.

    2017-02-01

    A high-throughput and robust application of the 3-methyl-2-benzothiazolinone hydrazone (MBTH) method was developed for carbohydrate determination in microalgae. The traditional phenol-sulfuric acid method to quantify carbohydrates is strongly affected by algal biochemical components and exhibits a highly variable response to microalgal monosaccharides. We present a novel use of the MBTH method to accurately quantify carbohydrates in hydrolyzate after acid hydrolysis of algal biomass, without a need for neutralization. The MBTH method demonstrated consistent and sensitive quantitation of algae-specific monosaccharides down to 5 ug mL-1 without interference from other algae acidic hydrolyzate components.

  20. Decomposition of algal lipids in clay-enriched marine sediment under oxic and anoxic conditions

    Institute of Scientific and Technical Information of China (English)

    吕冬伟; 宋茜; 王旭晨

    2010-01-01

    A series of laboratory incubation experiments were conducted to examine the decomposition of algal organic matter in clay-enriched marine sediment under oxic and anoxic conditions.During the 245-day incubation period,changes in the concentrations of TOC,major algal fatty acid components (14:0,16:0,16:1,18:1 and 20:5),and n-alkanes (C16-C23) were quantified in the samples.Our results indicate that the organic matters were degraded more rapidly in oxic than anoxic conditions.Adsorption of fatty acids onto cla...

  1. Study on Immobilized Algal Cells for Treatment and Recycle of Refinery Wastewater

    Institute of Scientific and Technical Information of China (English)

    Yu Baocheng; Liu Deqi; Dong Lihua; Li Gang

    2005-01-01

    Compared to the algal oxidation pond, treatment of wastewater using the immobilized algal cell technology has excellent effect, which not only can effectively avoid the disadvantage of oxidation pond,but can also remarkably improve the efficiency of treating system and the effluent quality. When the treating system operates under an optimal control conditions, such as a 55% loading rate, an illumination intensity of 2500-3500 lux and a hydraulic residence time of 4 hours, the COD and ammonia nitrogen removal can reach 90%. Water after deep treatment can comply with the requirement of the refinery for the quality of recycled water.

  2. Algal tests with soil suspensions and elutriates: A comparative evaluation for PAH contaminated soils

    DEFF Research Database (Denmark)

    Baun, Anders; Justesen, Kasper Bo; Nyholm, Niels

    2002-01-01

    An algal growth inhibition test procedure with soil suspensions is proposed and evaluated for PAH-contaminated soil. The growth rate reduction of the standard freshwater green alga Pseudokirchneriella subcapitata (formerly known as Selenastrum capricornutum) was used as the toxicity endpoint......, and was quantified by measuring the fluorescence of solvent-extracted algal pigments. No growth rate reduction was detected for soil contents up to 20 g/l testing five non-contaminated Danish soils. Comparative testing with PAH-contaminated soil elutriates and soil suspensions showed that the suspensions had...

  3. Spatial and temporal variability of algal and lichen epiphytes on trees in relation to pollutant deposition in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Braakenhielm, S.; Liu Qinghong [Swedish University of Agricultural Sciences, Uppsala (Sweden). Dept. of Environmental Assessment

    1995-01-01

    Green algae on Norway spruce needles and lichens on Scots pine and birch bark have been monitored for four and ten years, respectively, within the National Swedish Environmental Monitoring Program (PMK). Their spatial and temporal patterns in Sweden were analyzed. Algal colony thickness and colonization rate on needles increased from north to south and from east to west, but also with length of growing season and amount of atmospheric N and S deposition. However, no clear temporal trend was found over the 10 yr monitoring period. In general, patterns for sensitive lichens were opposite to those observed for the algae. Weighted Mean Sensitivity (WMS) of lichens was determined to be the best index of air quality among three indices evaluated. WMS increased from south to north, from west to east, and decreased with increasing deposition of N and S. The observed geographic, pollutional and biological variables were highly correlated with each other. Therefore, the relationships between biological and environmental factors cannot be clarified at the present time. 15 refs., 7 figs., 2 tabs.

  4. Formation of a Volunteer Harmful Algal Bloom Network in British Columbia, Canada, Following an Outbreak of Diarrhetic Shellfish Poisoning

    Directory of Open Access Journals (Sweden)

    Nicola Haigh

    2013-10-01

    Full Text Available Evidence for shellfish toxin illness in British Columbia (BC on the west coast of Canada can be traced back to 1793. For over two hundred years, domestically acquired bivalve shellfish toxin illnesses in BC were solely ascribed to paralytic shellfish poisonings caused by algal blooms of Alexandrium. This changed in 2011, when BC experienced its first outbreak of diarrhetic shellfish poisoning (DSP. As a result of this outbreak, Canada’s first DSP symposium was held in November, 2012, in North Vancouver, BC. Three of the objectives of the symposium were to provide a forum to educate key stakeholders on this emerging issue, to identify research and surveillance priorities and to create a DSP network. The purpose of this paper is to review what is known about shellfish poisoning in BC and to describe a novel volunteer network that arose following the symposium. The newly formed network was designed for industry shellfish growers to identify harmful algae bloom events, so that they may take actions to mitigate the effects of harmful blooms on shellfish morbidity. The network will also inform public health and regulatory stakeholders of potentially emerging issues in shellfish growing areas.

  5. Alginate and Algal-Based Beads for the Sorption of Metal Cations: Cu(II) and Pb(II)

    Science.gov (United States)

    Wang, Shengye; Vincent, Thierry; Faur, Catherine; Guibal, Eric

    2016-01-01

    Alginate and algal-biomass (Laminaria digitata) beads were prepared by homogeneous Ca ionotropic gelation. In addition, glutaraldehyde-crosslinked poly (ethyleneimine) (PEI) was incorporated into algal beads. The three sorbents were characterized by scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDX): the sorption occurs in the whole mass of the sorbents. Sorption experiments were conducted to evaluate the impact of pH, sorption isotherms, and uptake kinetics. A special attention was paid to the effect of drying (air-drying vs. freeze-drying) on the mass transfer properties. For alginate, freeze drying is required for maintaining the porosity of the hydrogel, while for algal-based sorbents the swelling of the material minimizes the impact of the drying procedure. The maximum sorption capacities observed from experiments were 415, 296 and 218 mg Pb g−1 and 112, 77 and 67 mg Cu g−1 for alginate, algal and algal/PEI beads respectively. Though the sorption capacities of algal-beads decreased slightly (compared to alginate beads), the greener and cheaper one-pot synthesis of algal beads makes this sorbent more competitive for environmental applications. PEI in algal beads decreases the sorption properties in the case of the sorption of metal cations under selected experimental conditions. PMID:27598128

  6. Analysis of algal bloom risk with uncertainties in lakes by integrating self-organizing map and fuzzy information theory

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Qiuwen, E-mail: qchen@rcees.ac.cn [RCEES, Chinese Academy of Sciences, Shuangqinglu 18, Beijing 10085 (China); China Three Gorges University, Daxuelu 8, Yichang 443002 (China); CEER, Nanjing Hydraulics Research Institute, Guangzhoulu 223, Nanjing 210029 (China); Rui, Han; Li, Weifeng; Zhang, Yanhui [RCEES, Chinese Academy of Sciences, Shuangqinglu 18, Beijing 10085 (China)

    2014-06-01

    Algal blooms are a serious problem in waters, which damage aquatic ecosystems and threaten drinking water safety. However, the outbreak mechanism of algal blooms is very complex with great uncertainty, especially for large water bodies where environmental conditions have obvious variation in both space and time. This study developed an innovative method which integrated a self-organizing map (SOM) and fuzzy information diffusion theory to comprehensively analyze algal bloom risks with uncertainties. The Lake Taihu was taken as study case and the long-term (2004–2010) on-site monitoring data were used. The results showed that algal blooms in Taihu Lake were classified into four categories and exhibited obvious spatial–temporal patterns. The lake was mainly characterized by moderate bloom but had high uncertainty, whereas severe blooms with low uncertainty were observed in the northwest part of the lake. The study gives insight on the spatial–temporal dynamics of algal blooms, and should help government and decision-makers outline policies and practices on bloom monitoring and prevention. The developed method provides a promising approach to estimate algal bloom risks under uncertainties. - Highlights: • An innovative method is developed to analyze algal bloom risks with uncertainties. • The algal blooms in Taihu Lake showed obvious spatial and temporal patterns. • The lake is mainly characterized as moderate bloom but with high uncertainty. • Severe bloom with low uncertainty appeared occasionally in the northwest part. • The results provide important information to bloom monitoring and management.

  7. Link between Domoic Acid Production and Cell Physiology after Exchange of Bacterial Communities between Toxic Pseudo-nitzschia multiseries and Non-Toxic Pseudo-nitzschia delicatissima

    Directory of Open Access Journals (Sweden)

    Aurélie Lelong

    2014-06-01

    Full Text Available Bacteria are known to influence domoic acid (DA production by Pseudo-nitzschia spp., but the link between DA production and physiology of diatoms requires more investigation. We compared a toxic P. multiseries to a non-toxic P. delicatissima, investigating links between DA production, physiological parameters, and co-occurring bacteria. Bacterial communities in cultures of both species were reduced by antibiotic treatment, and each of the diatoms was inoculated with the bacterial community of the other species. The physiology of P. delicatissima was minimally affected by the absence of bacteria or the presence of alien bacteria, and no DA was detected. P. multiseries grew faster without bacteria, did not produce a significant amount of DA, and exhibited physiological characteristics of healthy cells. When grown with alien bacteria, P. multiseries did not grow and produced more DA; the physiology of these cells was affected, with decreases in chlorophyll content and photosynthetic efficiency, an increase in esterase activity, and almost 50% mortality of the cells. The alien bacterial community had morphological and cellular characteristics very different from the original bacteria, and the number of free-living bacteria per algal cell was much higher, suggesting the involvement of bacteria in DA production.

  8. Process Design and Economics for the Production of Algal Biomass: Algal Biomass Production in Open Pond Systems and Processing Through Dewatering for Downstream Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Ryan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Markham, Jennifer [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kinchin, Christopher [National Renewable Energy Lab. (NREL), Golden, CO (United States); Grundl, Nicholas [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tan, Eric C.D. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Humbird, David [DWH Process Consulting, Denver, CO (United States)

    2016-02-17

    This report describes in detail a set of aspirational design and process targets to better understand the realistic economic potential for the production of algal biomass for subsequent conversion to biofuels and/or coproducts, based on the use of open pond cultivation systems and a series of dewatering operations to concentrate the biomass up to 20 wt% solids (ash-free dry weight basis).

  9. Process Design and Economics for the Conversion of Algal Biomass to Biofuels: Algal Biomass Fractionation to Lipid-and Carbohydrate-Derived Fuel Products

    Energy Technology Data Exchange (ETDEWEB)

    None

    2014-09-11

    The U.S. Department of Energy (DOE) promotes the production of a range of liquid fuels and fuel blendstocks from biomass feedstocks by funding fundamental and applied research that advances the state of technology in biomass production, conversion, and sustainability. As part of its involvement in this program, the National Renewable Energy Laboratory (NREL) investigates the conceptual production economics of these fuels. This includes fuel pathways from lignocellulosic (terrestrial) biomass, as well as from algal (aquatic) biomass systems.

  10. Fast growing research on negative emissions

    Science.gov (United States)

    Minx, Jan C.; Lamb, William F.; Callaghan, Max W.; Bornmann, Lutz; Fuss, Sabine

    2017-03-01

    Generating negative emissions by removing carbon dioxide from the atmosphere is a key requirement for limiting global warming to well below 2 °C, or even 1.5 °C, and therefore for achieving the long-term climate goals of the recent Paris Agreement. Despite being a relatively young topic, negative emission technologies (NETs) have attracted growing attention in climate change research over the last decade. A sizeable body of evidence on NETs has accumulated across different fields that is by today too large and too diverse to be comprehensively tracked by individuals. Yet, understanding the size, composition and thematic structure of this literature corpus is a crucial pre-condition for effective scientific assessments of NETs as, for example, required for the new special report on the 1.5 °C by the Intergovernmental Panel on Climate Change (IPCC). In this paper we use scientometric methods and topic modelling to identify and characterize the available evidence on NETs as recorded in the Web of Science. We find that the development of the literature on NETs has started later than for climate change as a whole, but proceeds more quickly by now. A total number of about 2900 studies have accumulated between 1991 and 2016 with almost 500 new publications in 2016. The discourse on NETs takes place in distinct communities around energy systems, forests as well as biochar and other soil carbon options. Integrated analysis of NET portfolios—though crucial for understanding how much NETs are possible at what costs and risks—are still in their infancy and do not feature as a theme across the literature corpus. Overall, our analysis suggests that NETs research is relatively marginal in the wider climate change discourse despite its importance for global climate policy.

  11. Remote Sensing Marine Ecology: Wind-driven algal blooms in the open oceans and their ecological impacts

    Science.gov (United States)

    Tang, DanLing

    2016-07-01

    Algal bloom not only can increase the primary production but also could result in negative ecological consequence, e.g., Harmful Algal Blooms (HABs). According to the classic theory for the formation of algal blooms "critical depth" and "eutrophication", oligotrophic sea area is usually difficult to form a large area of algal blooms, and actually the traditional observation is only sporadic capture to the existence of algal blooms. Taking full advantage of multiple data of satellite remote sensing, this study: 1), introduces "Wind-driven algal blooms in open oceans: observation and mechanisms" It explained except classic coastal Ekman transport, the wind through a variety of mechanisms affecting the formation of algal blooms. Proposed a conceptual model of "Strong wind -upwelling-nutrient-phytoplankton blooms" in Western South China Sea (SCS) to assess role of wind-induced advection transport in phytoplankton bloom formation. It illustrates the nutrient resources that support long-term offshore phytoplankton blooms in the western SCS; 2), Proposal of the theory that "typhoons cause vertical mixing, induce phytoplankton blooms", and quantify their important contribution to marine primary production; Proposal a new ecological index for typhoon. Proposed remote sensing inversion models. 3), Finding of the spatial and temporaldistributions pattern of harmful algal bloom (HAB)and species variations of HAB in the South Yellow Sea and East China Sea, and in the Pearl River estuary, and their oceanic dynamic mechanisms related with monsoon; The project developed new techniques and generated new knowledge, which significantly improved understanding of the formation mechanisms of algal blooms. 1), It proposed "wind-pump" mechanism integrates theoretical system combing "ocean dynamics, development of algal blooms, and impact on primary production", which will benefit fisheries management. 2), A new interdisciplinary subject "Remote Sensing Marine Ecology"(RSME) has been

  12. Community Garden Information Systems: Analyzing and Strengthening Community-Based Resource Sharing Networks

    Science.gov (United States)

    Loria, Kristen

    2013-01-01

    Extension professionals play an increasingly central role in supporting community garden and other community-based agriculture projects. With growing interest in community gardens as tools to improve community health and vitality, the best strategies for supporting these projects should be explored. Due to the importance of inter-personal networks…

  13. Subject Departments as Professional Communities?

    Science.gov (United States)

    Visscher, Adrie J.; Witziers, Bob

    2004-01-01

    A growing body of literature suggests that when schools become professional communities there are expected benefits in terms of teacher learning, school improvement and student achievement. In this article the concept of professional communities is examined for certain subject departments in Dutch secondary schools. The authors report on research…

  14. Subject departments as professional communities?

    NARCIS (Netherlands)

    Visscher, Adrie J.; Witziers, Bob

    2004-01-01

    A growing body of literature suggests that when schools become professional communities there are expected benefits in terms of teacher learning, school improvement and student achievement. In this article the concept of professional communities is examined for certain subject departments in Dutch s

  15. BASF's Investment in China Growing Steadily

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Over the next 10 years, BASF expects the chemical markets in Asia (excluding Japan) to grow by an average of 6 percent per year,well above the global average of 3.4 percent. For fast-growing markets such as China, the chemical market is projected to grow at a rate higher than Gross Domestic Product (GDP) due to the positive outlook brought by China's entry into the World Trade Organisation (WTO).

  16. China’s growing role in the South Atlantic

    Directory of Open Access Journals (Sweden)

    Adriana Erthal Abdenur

    2013-09-01

    Full Text Available Over the past decade, the flow of goods, people and ideas across the South Atlantic has increased considerably, due not only to growing trade and cooperation ties between South America and Africa, but also to the new interests of extra-regional emerging powers such as the People’s Republic of China. This article examines China’s growing role in the region in three different spheres (economic, political andsecurity interests in light of its changing strategy in developing countries; the role of non-state actors such as corporations and diaspora communities is also included. The authors conclude that, even though the Chinese state does not yet have a “South Atlantic policy”, the region has gained strategic importance for China. Finally, the article highlights China’s renewed interest in Antarctica.

  17. Growing Languages with Metamorphic Syntax Macros

    DEFF Research Database (Denmark)

    Brabrand, Claus; Schwartzbach, Michael Ignatieff

    2002-01-01

    "From now on, a main goal in designing a language should be to plan for growth." Guy Steele: Growing a Language, OOPSLA '98 invited talk.We present our experiences with a syntax macro language which we claim forms a general abstraction mechanism for growing (domain-specific) extensions of program......"From now on, a main goal in designing a language should be to plan for growth." Guy Steele: Growing a Language, OOPSLA '98 invited talk.We present our experiences with a syntax macro language which we claim forms a general abstraction mechanism for growing (domain-specific) extensions...

  18. Production of Algal-based Biofuel from Non-fresh Water Sources

    Science.gov (United States)

    Sun, A. C.; Reno, M. D.

    2008-12-01

    A system dynamics model is developed to assess the availability and feasibility of non-traditional water sources from dairy wastewater, produced water from crude oil production and from coal-bed methane gas extraction for the production of algal-based biofuel. The conceptual framework is based on two locales within New Mexico, the San Juan basin in the northwest and the Permian basin in the southeast, where oil and gas drilling have increased considerably in the last ten years. The simulation framework contains an algal growth module, a dairy module, an oil production module, and a gas production module. Our preliminary investigation indicates a cyclical demand for non-fresh water due to the cyclical nature of algal biomass production and crop evapotranspiration. The wastewater from the dairy industry is not a feasible non-fresh water source because the agricultural water demand for cow's dry feed far exceeds the amount generated at the dairy. The uncertainty associated with the water demand for cow's dry matter intake is the greatest in this model. The oil and gas produced water, ignoring the quality, provides ample supply for water demand in algal biomass production. There remains work to address technical challenges associated with coupling the appropriate non-fresh water source to the local demand.

  19. A neurophysiological method of rapid detection and analysis of marine algal toxins

    DEFF Research Database (Denmark)

    Kerr, DS; Bødtkjer, Donna Briggs; Saba, HI

    1999-01-01

    We have examined the effectiveness of the in vitro rat hippocampal slice preparation as a means of rapidly and specifically detecting the marine algal toxins saxitoxin, brevetoxin, and domoic acid and have identified toxin-specific electrophysiological signatures for each. Brevetoxin (PbTX3, 50-2...

  20. An optimized method for automated analysis of algal pigments by HPLC

    NARCIS (Netherlands)

    van Leeuwe, M. A.; Villerius, L. A.; Roggeveld, J.; Visser, R. J. W.; Stefels, J.

    2006-01-01

    A recent development in algal pigment analysis by high-performance liquid chromatography (HPLC) is the application of automation. An optimization of a complete sampling and analysis protocol applied specifically in automation has not yet been performed. In this paper we show that automation can only

  1. Methylene blue adsorption by algal biomass based materials: biosorbents characterization and process behaviour.

    Science.gov (United States)

    Vilar, Vítor J P; Botelho, Cidália M S; Boaventura, Rui A R

    2007-08-17

    Dead algal biomass is a natural material that serves as a basis for developing a new family of sorbent materials potentially suitable for many industrial applications. In this work an algal industrial waste from agar extraction process, algae Gelidium and a composite material obtained by immobilization of the algal waste with polyacrylonitrile (PAN) were physical characterized and used as biosorbents for dyes removal using methylene blue as model. The apparent and real densities and the porosity of biosorbents particles were determined by mercury porosimetry and helium picnometry. The methylene blue adsorption in the liquid phase was the method chosen to calculate the specific surface area of biosorbent particles as it seems to reproduce better the surface area accessible to metal ions in the biosorption process than the N2 adsorption-desorption dry method. The porous texture of the biosorbents particles was also studied. Equilibrium isotherms are well described by the Langmuir equation, giving maximum uptake capacities of 171, 104 and 74 mg g(-1), respectively for algae, algal waste and composite material. Kinetic experiments at different initial methylene blue concentrations were performed to evaluate the equilibrium time and the importance of the driving force to overcome mass transfer resistances. The pseudo-first-order and pseudo-second-order kinetic models adequately describe the kinetic data. The biosorbents used in this work proved to be promising materials for removing methylene blue from aqueous solutions.

  2. Removal of nitrogen by Algal Turf Scrubber Technology in recirculating aquaculture system

    NARCIS (Netherlands)

    Valeta, J.; Verdegem, M.C.J.

    2015-01-01

    Ongoing research in recirculation aquaculture focuses on evaluating and improving the purification potential of different types of filters. Algal Turf Scrubber (ATS) are special as they combine sedimentation and biofiltration. An ATS was subjected to high nutrient loads of catfish effluent to examin

  3. Post-extraction algal residue in steam-flaked corn-based diets for beef cattle

    Science.gov (United States)

    The effects of post-extraction algal residue (PEAR) as N source 23 in steam-flaked corn-based (SFC) beef cattle finishing diets on intake, duodenal flow, digestion, ruminal microbial efficiency, ruminal parameters, and blood constituents were evaluated. Ruminally and duodenally cannulated steers (BW...

  4. Extractive-transesterification of algal lipids under microwave irradiation with hexane as solvent.

    Science.gov (United States)

    Martinez-Guerra, Edith; Gude, Veera Gnaneswar; Mondala, Andro; Holmes, William; Hernandez, Rafael

    2014-03-01

    This study describes the use of microwaves (MW) for enhanced extractive-transesterification of algal lipids from dry algal biomass (Chlorella sp.). Two different single-step extractive-transesterification methods under MW irradiation were evaluated: (1) with ethanol as solvent/reactant and sodium hydroxide catalyst; and (2) with ethanol as reactant and hexane as solvent (sodium hydroxide catalyst). Biodiesel (fatty-acid-ethyl-esters, FAEE) yields from these two methods were compared with the conventional Bligh and Dyer (BD) method which followed a two-step extraction-transesterification process. The maximum lipid yields for MW, MW with hexane and BD methods were 20.1%, 20.1%, and 13.9%, respectively; while the FAEE conversion of the algal lipids were 96.2%, 94.3%, and 78.1%, respectively. The algae-biomass:ethanol molar ratio of 1:250-500 and 2.0-2.5% catalyst with reaction times around 6min were determined as optimum conditions for both methods. This study confers that the single-step non-conventional methods can contribute to higher algal lipid and FAEE yields.

  5. Remote sensing models using Landsat satellite data to monitor algal blooms in Lake Champlain.

    Science.gov (United States)

    Trescott, A; Park, M-H

    2013-01-01

    Lake Champlain is significantly impaired by excess phosphorus loading, requiring frequent lake-wide monitoring for eutrophic conditions and algal blooms. Satellite remote sensing provides regular, synoptic coverage of algal production over large areas with better spatial and temporal resolution compared with in situ monitoring. This study developed two algal production models using Landsat Enhanced Thematic Mapper Plus (ETM(+)) satellite imagery: a single band model and a band ratio model. The models predicted chlorophyll a concentrations to estimate algal cell densities throughout Lake Champlain. Each model was calibrated with in situ data compiled from summer 2006 (July 24 to September 10), and then validated with data for individual days in August 2007 and 2008. Validation results for the final single band and band ratio models produced Nash-Sutcliffe efficiency (NSE) coefficients of 0.65 and 0.66, respectively, confirming satisfactory model performance for both models. Because these models have been validated over multiple days and years, they can be applied for continuous monitoring of the lake.

  6. Juvenile corals can acquire more carbon from high-performance algal symbionts

    NARCIS (Netherlands)

    Cantin, N. E.; van Oppen, M. J. H.; Willis, B. L.; Mieog, J. C.; Negri, A. P.

    2009-01-01

    Algal endosymbionts of the genus Symbiodinium play a key role in the nutrition of reef building corals and strongly affect the thermal tolerance and growth rate of the animal host. This study reports that (14)C photosynthate incorporation into juvenile coral tissues was doubled in Acropora millepora

  7. THE USE OF ALGAE CONCENTRATES, DRIED ALGAE AND ALGAL SUBSTITUTES TO FEED BIVALVES

    Directory of Open Access Journals (Sweden)

    Ludi Parwadani Aji

    2011-01-01

    Full Text Available Microalgae have high nutritional value and are used to feed adult and larval stages of bivalves, the larvae of some fish and crustaceans and zooplankton. However, microalgae production for aquaculture animal is very expensive. To overcome this, the use of preserved microalgae such as algae concentrate and dried algae, or algal substitutes has been developed. There are both advantages and disadvantages to this alternative food. For example, even though the cost production for algal substitute yeast-based diet is cheaper, their nutritional value is much lower compared to fresh microalgae. Moreover, there is no significant difference in nutritional value between preserved (concentrated or dried and fresh microalgae; however, preserving microalgae for long periods will affect their nutritional value. In spite of this problem, preserved microalgae such as algal concentrate and dried algae seem to be more effective to feed bivalves than algal substitutes yeast based diet due to their availability and relatively high nutritional value. Furthermore, algae concentrates are more suitable to replace fresh algae than dried algae.

  8. Algal eating habits of phycologists attending the ISAP Halifax Conference and members of the general public

    DEFF Research Database (Denmark)

    Edwards, Maeve D.; Holdt, Susan Løvstad; Hynes, Stephen;

    2012-01-01

    A short questionnaire was devised during the 4th ISAP Conference in Halifax (2011) to gather some information on the algal eating habits of the participants. Responses were also collected from random members of the general public in Galway and Copenhagen. Most phycologists had eaten algae before ...

  9. The Hawaiian Algal Database: a laboratory LIMS and online resource for biodiversity data

    Directory of Open Access Journals (Sweden)

    Sauvage Thomas

    2009-09-01

    Full Text Available Abstract Background Organization and presentation of biodiversity data is greatly facilitated by databases that are specially designed to allow easy data entry and organized data display. Such databases also have the capacity to serve as Laboratory Information Management Systems (LIMS. The Hawaiian Algal Database was designed to showcase specimens collected from the Hawaiian Archipelago, enabling users around the world to compare their specimens with our photographs and DNA sequence data, and to provide lab personnel with an organizational tool for storing various biodiversity data types. Description We describe the Hawaiian Algal Database, a comprehensive and searchable database containing photographs and micrographs, geo-referenced collecting information, taxonomic checklists and standardized DNA sequence data. All data for individual samples are linked through unique accession numbers. Users can search online for sample information by accession number, numerous levels of taxonomy, or collection site. At the present time the database contains data representing over 2,000 samples of marine, freshwater and terrestrial algae from the Hawaiian Archipelago. These samples are primarily red algae, although other taxa are being added. Conclusion The Hawaiian Algal Database is a digital repository for Hawaiian algal samples and acts as a LIMS for the laboratory. Users can make use of the online search tool to view and download specimen photographs and micrographs, DNA sequences and relevant habitat data, including georeferenced collecting locations. It is publicly available at http://algae.manoa.hawaii.edu.

  10. Impact of Harmful Algal Blooms on Several Lake Erie Drinking Water Treatment Plants

    Science.gov (United States)

    Recent events in Ohio have demonstrated the challenge treatment facilities face in providing safe drinking water when encountering extreme harmful algal bloom (HAB) events. Over the last two years the impact of HAB-related microcystins on several drinking water treatment facilit...

  11. Potentially harmful microalgae and algal blooms in a eutrophic estuary in Turkey

    Directory of Open Access Journals (Sweden)

    S. TAS

    2015-07-01

    Full Text Available Distribution of potentially harmful microalgae and algal blooms were investigated at monthly and weekly time scales between October 2009 and September 2010 in the Golden Horn, a eutrophic estuary in the Sea of Marmara (Turkey. Several physical and chemical parameters were analysed together with phytoplankton composition and abundance. A total number of 23 potentially harmful and/or bloom-forming microalgae (14 dinoflagellates, 4 diatoms and 5 phytoflagellates were identified throughout this study period, of which nine taxa have been confirmed to be toxic elsewhere in the world. Most harmful species and algal blooms were observed in late spring and summer particularly in the middle and upper estuaries, and nine taxa formed dense and successive algal blooms causing water discoloration. Nutrient concentrations increased significantly from the lower to the upper estuary. Additionally, high organic matter loads in the upper estuary could also have benefited by mixotrophic species. The increasing number of potentially harmful and bloom-forming species and algal blooms indicated that the GHE is a potential risk area for future HABs. 

  12. Green genes: bioinformatics and systems-biology innovations drive algal biotechnology

    NARCIS (Netherlands)

    Reijnders, M.J.M.F.; Heck, van R.G.A.; Lam, C.M.C.; Scaife, M.A.; Martins dos Santos, V.A.P.; Smith, A.G.; Schaap, P.J.

    2014-01-01

    Many species of microalgae produce hydrocarbons, polysaccharides, and other valuable products in significant amounts. However, large-scale production of algal products is not yet competitive against non-renewable alternatives from fossil fuel. Metabolic engineering approaches will help to improve pr

  13. A novel algal biofilm membrane photobioreactor for attached microalgae growth and nutrients removal from secondary effluent.

    Science.gov (United States)

    Gao, Feng; Yang, Zhao-Hui; Li, Chen; Zeng, Guang-Ming; Ma, Dan-Hui; Zhou, Li

    2015-03-01

    In this study, a novel algal biofilm membrane photobioreactor (BMPBR) equipped with solid carriers and submerged membrane module was developed for attached growth of Chlorella vulgaris and secondary effluent treatment. The volumetric microalgae production achieved in BMPBR was 0.072 g L(-1) d(-1), which was 1.44-fold larger than that in suspended growth membrane photobioreactor (MPBR). Furthermore, 72.4% of the total produced algal biomass was immobilized as algal biofilm in BMPBR. Advanced nutrients removal from secondary effluent was achieved both in BMPBR and MPBR, with average reduction of about 85% for PO4(3-)-P in the stable stage. Additionally, BMPBR showed better nitrogen removal performance than MPBR due to its higher algal biomass productivity. Moreover, with the filtration effect of the submerged membrane module in the reactor, suspended microalgae could be completely isolated from the effluent and a low average SS concentration of 0.28 mg L(-1) was achieved in the effluent of BMPBR.

  14. Micropollutant removal in an algal treatment system fed with source separated wastewater streams

    NARCIS (Netherlands)

    de Wilt, Arnoud; Butkovskyi, Andrii; Tuantet, Kanjana; Hernandez Leal, Lucia; Fernandes, T.V.; Langenhoff, Alette; Zeeman, Grietje

    2016-01-01

    Micropollutant removal in an algal treatment system fed with source separated wastewater streams was studied. Batch experiments with the microalgae Chlorella sorokiniana grown on urine, anaerobically treated black water and synthetic urine were performed to assess the removal of six spiked pharmaceu

  15. Methane and nitrous oxide emissions affect the life-cycle analysis of algal biofuels

    Science.gov (United States)

    Frank, Edward D.; Han, Jeongwoo; Palou-Rivera, Ignasi; Elgowainy, Amgad; Wang, Michael Q.

    2012-03-01

    Researchers around the world are developing sustainable plant-based liquid transportation fuels (biofuels) to reduce petroleum consumption and greenhouse gas emissions. Algae are attractive because they promise large yields per acre compared to grasses, grains and trees, and because they produce oils that might be converted to diesel and gasoline equivalents. It takes considerable energy to produce algal biofuels with current technology; thus, the potential benefits of algal biofuels compared to petroleum fuels must be quantified. To this end, we identified key parameters for algal biofuel production using GREET, a tool for the life-cycle analysis of energy use and emissions in transportation systems. The baseline scenario produced 55 400 g CO2 equivalent per million BTU of biodiesel compared to 101 000 g for low-sulfur petroleum diesel. The analysis considered the potential for greenhouse gas emissions from anaerobic digestion processes commonly used in algal biofuel models. The work also studied alternative scenarios, e.g., catalytic hydrothermal gasification, that may reduce these emissions. The analysis of the nitrogen recovery step from lipid-extracted algae (residues) highlighted the importance of considering the fate of the unrecovered nitrogen fraction, especially that which produces N2O, a potent greenhouse gas with global warming potential 298 times that of CO2.

  16. Digestion of algal biomass for electricity generation in microbial fuel cells.

    Science.gov (United States)

    Nishio, Koichi; Hashimoto, Kazuhito; Watanabe, Kazuya

    2013-01-01

    Algal biomass serves as a fuel for electricity generation in microbial fuel cells. This study constructed a model consortium comprised of an alga-digesting Lactobacillus and an iron-reducing Geobacter for electricity generation from photo-grown Clamydomonas cells. Total power-conversion efficiency (from Light to electricity) was estimated to be 0.47%.

  17. Determination of Total Solids and Ash in Algal Biomass: Laboratory Analytical Procedure (LAP)

    Energy Technology Data Exchange (ETDEWEB)

    Van Wychen, S.; Laurens, L. M. L.

    2013-12-01

    This procedure describes the methods used to determine the amount of moisture or total solids present in a freeze-dried algal biomass sample, as well as the ash content. A traditional convection oven drying procedure is covered for total solids content, and a dry oxidation method at 575?C is covered for ash content.

  18. Comparison of Algal Biodiesel Production Pathways Using Life Cycle Assessment Tool

    DEFF Research Database (Denmark)

    Singh, Anoop; Olsen, Stig Irving

    2013-01-01

    The consideration of algal biomass in biodiesel production increased very rapidly in the last decade. A life cycle assessment (LCA) study is presented to compare six different biodiesel production pathways (three different harvesting techniques, i.e., aluminum as flocculent, lime flocculent...

  19. Nutritional evaluation of farm-waste-grown and axenically cultured algal biomass

    Energy Technology Data Exchange (ETDEWEB)

    Strain, J.J.; Fallowfield, H.J.; Fraser, T.W.; Garrett, M.K.

    1986-01-01

    Algal biomass produced in an outdoor pilot plant facility for the treatment of the liquid phase of pig slurry was nutritionally evaluated together with Chlorella vulgaris 211/le produced axenically in defined media in laboratory chemostats. Data from amino acid analyses showed that the sulphur-containing amino acids were limiting. Digestibility, net protein utilisation and biological values of the algal products were assayed. In vivo and in vitro enzymic digestions were monitored by transmission electron microscopy. Although the cell wall was only partially digested, the cell contents, and especially the pyrenoid, were extensively digested in several treatments. The most indigestible components of the cell may be the membranes of the chloroplast. It is suggested that the absence of sporopollenin from the cell wall of this alga may be responsible for the high nitrogen digestibility of the laboratory-produced material. The waste-grown algal biomass contained appreciable amounts of algal species other than Chlorella vulgaris 211/le which may have contributed to the lower digestibility of this material. 44 references.

  20. Two-stage Hydrolysis of Invasive Algal Feedstock for Ethanol Fermentation

    Institute of Scientific and Technical Information of China (English)

    Xin Wang; Xianhua Liu; Guangyi Wang

    2011-01-01

    The overall goal of this work was to develop a saccharification method for the production of third generation biofuel(i.e.bioethanol) using feedstock of the invasive marine macroalga Gracilaria salicornia.Under optimum conditions(120℃ and 2% sulfuric acid for 30 min), dilute acid hydrolysis of the homogenized invasive plants yielded a low concentration of glucose(4.1mM or 4.3g glucose/kg fresh algal biomass). However, two-stage hydrolysis of the homogenates (combination of dilute acid hydrolysis with enzymatic hydrolysis) produced 13.8g of glucose from one kilogram of fresh algal feedstock. Batch fermentation analysis produced 79.1g EtOH from one kilogram of dried invasive algal feedstock using the ethanologenic strain Escherichia coli K011. Furthermore, ethanol production kinetics indicated that the invasive algal feedstock contained different types of sugar, including C5-sugar. This study represents the first report on third generation biofuel production from invasive macroalgae, suggesting that there is great potential for the production of renewable energy using marine invasive biomass.