WorldWideScience

Sample records for algal enteromorpha zoospores

  1. Effect of temperature, salinity and biofilm on the zoospores settlement of Enteromorpha flexuosa (Wulfen) J.Agardh

    Digital Repository Service at National Institute of Oceanography (India)

    Imchen, T.

    by permanent adhesion through rapid secretion and curing of an N-linked, self-aggregating glycoprotein that anchors the spore to the substratum surface4. A variety of factors influence settlement of zoospores (biological4; topography of surface5-6; charge...

  2. Evaluation of the Strength of Attachment of Enteromorpha Zoospores to Novel Polymer Surfaces

    National Research Council Canada - National Science Library

    Callow, James

    2002-01-01

    .... The objective of this research was to use these two species as models to understand fundamental aspects of adhesion and to apply this mechanistic understanding to a practical, laboratory scale...

  3. Zoospore exudates from Phytophthora nicotianae affect immune responses in Arabidopsis.

    Science.gov (United States)

    Kong, Ping; McDowell, John M; Hong, Chuanxue

    2017-01-01

    Zoospore exudates play important roles in promoting zoospore communication, homing and germination during plant infection by Phytophthora. However, it is not clear whether exudates affect plant immunity. Zoospore-free fluid (ZFF) and zoospores of P. nicotianae were investigated comparatively for effects on resistance of Arabidopsis thaliana Col-0 and mutants that affect signaling mediated by salicylic acid (SA) and jasmonic acid (JA): eds16 (enhanced disease susceptibility16), pad4 (phytoalexin deficient4), and npr1 (nonexpressor of pathogenesis-related genes1). Col-0 attracted more zoospores and had severe tissue damage when flooded with a zoospore suspension in ZFF. Mutants treated with ZFF alone developed disease symptoms similar to those inoculated with zoospores and requirements of EDS16 and PAD4 for plant responses to zoospores and the exudates was apparent. Zoospore and ZFFs also induced expression of the PR1 and PDF1.2 marker genes for defense regulated by SA and JA, respectively. However, ZFF affected more JA defense signaling, down regulating PR1 when SA signaling or synthesis is deficient, which may be responsible for Arabidopsis mutant plants more susceptible to infection by high concentration of P. nicotianae zoospores. These results suggest that zoospore exudates can function as virulence factors and inducers of plant immune responses during plant infection by Phytophthora.

  4. Zoospore exudates from Phytophthora nicotianae affect immune responses in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Ping Kong

    Full Text Available Zoospore exudates play important roles in promoting zoospore communication, homing and germination during plant infection by Phytophthora. However, it is not clear whether exudates affect plant immunity. Zoospore-free fluid (ZFF and zoospores of P. nicotianae were investigated comparatively for effects on resistance of Arabidopsis thaliana Col-0 and mutants that affect signaling mediated by salicylic acid (SA and jasmonic acid (JA: eds16 (enhanced disease susceptibility16, pad4 (phytoalexin deficient4, and npr1 (nonexpressor of pathogenesis-related genes1. Col-0 attracted more zoospores and had severe tissue damage when flooded with a zoospore suspension in ZFF. Mutants treated with ZFF alone developed disease symptoms similar to those inoculated with zoospores and requirements of EDS16 and PAD4 for plant responses to zoospores and the exudates was apparent. Zoospore and ZFFs also induced expression of the PR1 and PDF1.2 marker genes for defense regulated by SA and JA, respectively. However, ZFF affected more JA defense signaling, down regulating PR1 when SA signaling or synthesis is deficient, which may be responsible for Arabidopsis mutant plants more susceptible to infection by high concentration of P. nicotianae zoospores. These results suggest that zoospore exudates can function as virulence factors and inducers of plant immune responses during plant infection by Phytophthora.

  5. Optimization of dilute acid hydrolysis of Enteromorpha

    Science.gov (United States)

    Feng, Dawei; Liu, Haiyan; Li, Fuchao; Jiang, Peng; Qin, Song

    2011-11-01

    Acid hydrolysis is a simple and direct way to hydrolyze polysaccharides in biomass into fermentable sugars. To produce fermentable sugars effectively and economically for fuel ethanol, we have investigated the hydrolysis of Enteromorpha using acids that are typically used to hydrolyze biomass: H2SO4, HCl, H3PO4 and C4H4O4 (maleic acid). 5%(w/w) Enteromorpha biomass was treated for different times (30, 60, and 90 min) and with different acid concentrations (0.6, 1.0, 1.4, 1.8, and 2.2%, w/w) at 121°C. H2SO4 was the most effective acid in this experiment. We then analyzed the hydrolysis process in H2SO4 in detail using high performance liquid chromatography. At a sulfuric acid concentration of 1.8% and treatment time of 60 min, the yield of ethanol fermentable sugars (glucose and xylose) was high, (230.5 mg/g dry biomass, comprising 175.2 mg/g glucose and 55.3 mg/g xylose), with 48.6% of total reducing sugars being ethanol fermentable. Therefore, Enteromorpha could be a good candidate for production of fuel ethanol. In future work, the effects of temperature and biomass concentration on hydrolysis, and also the fermentation of the hydrolysates to ethanol fuel should be focused on.

  6. Acute toxicity of live and decomposing green alga Ulva ( Enteromorpha) prolifera to abalone Haliotis discus hannai

    Science.gov (United States)

    Wang, Chao; Yu, Rencheng; Zhou, Mingjiang

    2011-05-01

    From 2007 to 2009, large-scale blooms of green algae (the so-called "green tides") occurred every summer in the Yellow Sea, China. In June 2008, huge amounts of floating green algae accumulated along the coast of Qingdao and led to mass mortality of cultured abalone and sea cucumber. However, the mechanism for the mass mortality of cultured animals remains undetermined. This study examined the toxic effects of Ulva ( Enteromorpha) prolifera, the causative species of green tides in the Yellow Sea during the last three years. The acute toxicity of fresh culture medium and decomposing algal effluent of U. prolifera to the cultured abalone Haliotis discus hannai were tested. It was found that both fresh culture medium and decomposing algal effluent had toxic effects to abalone, and decomposing algal effluent was more toxic than fresh culture medium. The acute toxicity of decomposing algal effluent could be attributed to the ammonia and sulfide presented in the effluent, as well as the hypoxia caused by the decomposition process.

  7. Primary Adhesion in Enteromorpha. Cue Detection and Surface Selection in the Settlement and Adhesion of Enteromorpha Spores

    National Research Council Canada - National Science Library

    Callow, James

    2001-01-01

    .... Since fouling by Enteromorpha is increasing as a consequence of the increased deployment of TBT-free coatings, it is important to understand the processes involved in the initiation of fouling, i.e...

  8. Ultrasound-enhanced rapid in situ transesterification of marine macroalgae Enteromorpha compressa for biodiesel production.

    Science.gov (United States)

    Suganya, Tamilarasan; Kasirajan, Ramachandran; Renganathan, Sahadevan

    2014-03-01

    In situ transesterification of Enteromorpha compressa algal biomass was carried out for the production of biodiesel. The maximum methyl esters (ME) yield of 98.89% was obtained using ultrasonic irradiation. Tetra hydro furan (THF) and acid catalyst (H2SO4) was found to be an appropriate co-solvent and catalyst for high free fatty acids (FFA) content E. compressa biomass to increase the efficiency of the reactive in situ process. The optimization study was conducted to obtain the maximum yield and it was determined as 30vol% of THF as a co-solvent, 10wt% of H2SO4, 5.5:1 ratio of methanol to algal biomass and 600rpm of mixing intensity at 65°C for 90min of ultrasonic irradiation time. The produced biodiesel was characterized by (1)H nuclear magnetic resonance spectroscopy ((1)H NMR) analysis. Kinetic studies revealed that the reaction followed the first-order reaction mechanism. Rapid in situ transesterification was found to be suitable technique to produce biodiesel from marine macroalgae feedstock. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Defective zoospore encystment and suppressed cyst germination of Phytophthora palmivora caused by transient leaching treatments

    NARCIS (Netherlands)

    Dijksterhuis, J; Deacon, J W

    2003-01-01

    The behaviour of encysting zoospores of Phytophthora palmivora during leaching conditions was studied. Zoospores encysted and germinated successfully on polycarbonate membranes after mechanical agitation. Transient (10 min) leaching treatments with nutrient-free buffer underneath the membranes

  10. Short communication: Algal leaf spot associated with Cephaleuros virescens (Trentepohliales, Ulvophyceae on Nephelium lappaceum in Thailand

    Directory of Open Access Journals (Sweden)

    ANURAG SUNPAPAO

    2016-05-01

    Full Text Available Abstract. Sunpapao A, Pitaloka MK, Arikit S. 2015. Algal leaf spot associated with Cephaleuros virescens (Trentepohliales, Ulvophyceae on Nephelium lappaceum in Thailand. Biodiversitas 17: 31-35. Algal leaf spot disease of Nephelium lappaceum (rambutan was observed in southern Thailand. The algae were isolated on Bold’s basal medium (BBM and identified based on appearance of the lesions, algal morphology and molecular properties. Characteristics of the filamentous thallus cells, sporangiophores, sporangia, gametes and zoospores were clarified. A portion of the 18S small subunit rRNA was amplified to validate the morphological identification by sequence similarity. To summarize the main results, the plant parasite causing algal leaf spot was identified as Cephaleuros virescens, and in sequencing-based phylogenetic analysis the Cephaleuros PSU-R5.1 isolate from rambutan grouped with the algae in genus Cephaleuros. This confirms C. virescens as a causal organism of algal leaf spot disease on rambutan in southern Thailand.

  11. Multimodal sensorimotor system in unicellular zoospores of a fungus.

    Science.gov (United States)

    Swafford, Andrew J M; Oakley, Todd H

    2018-01-19

    Complex sensory systems often underlie critical behaviors, including avoiding predators and locating prey, mates and shelter. Multisensory systems that control motor behavior even appear in unicellular eukaryotes, such as Chlamydomonas , which are important laboratory models for sensory biology. However, we know of no unicellular opisthokonts that control motor behavior using a multimodal sensory system. Therefore, existing single-celled models for multimodal sensorimotor integration are very distantly related to animals. Here, we describe a multisensory system that controls the motor function of unicellular fungal zoospores. We found that zoospores of Allomyces arbusculus exhibit both phototaxis and chemotaxis. Furthermore, we report that closely related Allomyces species respond to either the chemical or the light stimuli presented in this study, not both, and likely do not share this multisensory system. This diversity of sensory systems within Allomyces provides a rare example of a comparative framework that can be used to examine the evolution of sensory systems following the gain/loss of available sensory modalities. The tractability of Allomyces and related fungi as laboratory organisms will facilitate detailed mechanistic investigations into the genetic underpinnings of novel photosensory systems, and how multisensory systems may have functioned in early opisthokonts before multicellularity allowed for the evolution of specialized cell types. © 2018. Published by The Company of Biologists Ltd.

  12. Rhamnolipids as platform molecules for production of potential anti-zoospore agrochemicals.

    Science.gov (United States)

    Miao, Shida; Dashtbozorg, Soroosh Soltani; Callow, Nicholas V; Ju, Lu-Kwang

    2015-04-08

    Rhamnolipid biosurfactants have potential applications in the control of zoosporic plant pathogens. However, rhamnolipids have not been closely investigated for the anti-zoospore mechanism or for developing new anti-zoospore chemicals. In this study, RhL-1 and RhL-3 groups of rhamnolipids were used to generate the corresponding RhL-2 and RhL-4 groups and the free diacids. Conversion of RhL-3 to RhL-1 was also accomplished in vitro with cellobiase as the catalyst. The anti-zoospore effects of RhL-1-RhL-4 and the diacids were investigated with zoospores of Phytophthora sojae. For RhL-1-RhL-4, approximately 20, 30, 40, and 40 mg/L, respectively, were found to be the lowest concentrations required to stop movement of all zoospores, which indicates that the anti-zoospore effect remains strong even after RhL-1 and RhL-3 are hydrolyzed into RhL-2 and RhL-4. The free diacids required a significantly higher critical concentration of about 125 mg/L. Rhamnose can be obtained as a co-product.

  13. Zoosporic Tolerance to pH Stress and Its Implications for Phytophthora Species in Aquatic Ecosystems▿

    OpenAIRE

    Kong, Ping; Moorman, Gary W.; Lea-Cox, John D.; Ross, David S.; Richardson, Patricia A.; Hong, Chuanxue

    2009-01-01

    Phytophthora species, a group of destructive plant pathogens, are commonly referred to as water molds, but little is known about their aquatic ecology. Here we show the effect of pH on zoospore survival of seven Phytophthora species commonly isolated from irrigation reservoirs and natural waterways and dissect zoospore survival strategy. Zoospores were incubated in a basal salt liquid medium at pH 3 to 11 for up to 7 days and then plated on a selective medium to determine their survival. The ...

  14. Distribution and relationships between selected chemical elements in green alga Enteromorpha sp. from the southern Baltic

    International Nuclear Information System (INIS)

    Zbikowski, Radoslaw; Szefer, Piotr; Latala, Adam

    2006-01-01

    The concentrations of heavy metals (Cd, Cu, Ni, Pb, Zn and Mn) and macroelements (K, Na, Ca and Mg) were determined in green alga Enteromorpha sp. from the coastal zone of the southern Baltic including Gulf of Gdansk and Vistula Lagoon in 2000-2003. In order to estimate the degree of accumulation of each element by the green alga, concentration and discrimination factors (CFs) with respect to seawater were calculated. The results of factor analysis (FA) and ANOVA clearly indicate geographical differences between concentrations of chemical elements. Enteromorpha sp. from Vistula Lagoon and the southern Baltic exhibited higher levels of Mn and Ni, and Na and K, respectively. Anthropogenic impact of Cu, Pb and Zn, possibly originated from municipal sewage, was identified in alga samples collected in the Gulf of Gdansk, especially in the vicinity of Gdynia. From comparison our data with those published earlier results that Pb content in Enteromorpha sp. from the Gulf of Gdansk decreased within 1978-2003 reflecting reducing use of leaded petrol in Baltic countries in this period. The alga Enteromorpha sp. can be used for biomonitoring surveys of metal contaminants in coastal areas of the Baltic Sea. - Enteromorpha sp. can be used as efficient biomonitor for chemical elements in coastal areas of the Baltic Sea

  15. Copper (II) Lead (II) and Zinc (II) reduce growth and zoospore release in four zoosporic true fungi from soils of NSW, Australia

    DEFF Research Database (Denmark)

    Henderson, Linda; Pilgaard, Bo; Gleason, Frank

    2015-01-01

    This study examined the responses of a group of four zoosporic true fungi isolated from soils in NSW Australia, to concentrations of toxic metals in the laboratory that may be found in polluted soils. All isolates showed greatest sensitivity to Cu and least sensitivity to Pb. All isolates showed ...... in 60 ppm Cu. If these metals cause similar effects in the field, Cu, Pb and Zn contamination of NSW soils is likely to reduce biomass of zoosporic true fungi. Loss of the fungi may reduce the rate of mineralisation of soil organic matter.......This study examined the responses of a group of four zoosporic true fungi isolated from soils in NSW Australia, to concentrations of toxic metals in the laboratory that may be found in polluted soils. All isolates showed greatest sensitivity to Cu and least sensitivity to Pb. All isolates showed...

  16. Recruitment potential of a green alga Ulva flexuosa Wolfen dark preserved zoospore and its development

    Digital Repository Service at National Institute of Oceanography (India)

    Imchen, T.

    Green Alga Ulva flexuosa Wulfen Dark Preserved Zoospore and Its Development Temjensangba Imchen* National Institute of Oceanography (Council of Scientific and Industrial Research), Goa, India Abstract The recruitment potential and the ability of Ulva... factors play a role in the process of recruitment. Citation: Imchen T (2012) Recruitment Potential of a Green Alga Ulva flexuosa Wulfen Dark Preserved Zoospore and Its Development. PLoS ONE 7(3): e32651. doi:10.1371/journal.pone.0032651 Editor: Ross...

  17. Effects of solar ultraviolet radiation on tropical algal communities

    International Nuclear Information System (INIS)

    Santas, R.

    1989-01-01

    This study assessed some of the effects of solar ultraviolet (UV) radiation ion coral reef algal assemblages. The first part of the investigation was carried out under controlled laboratory conditions in the coral reef microcosm at the National Museum of Natural History in Washington, D.C., while a field counterpart was completed at the Smithsonian Institution's marine station on Grand Turk, Turks and Caicos Islands, in the eastern Caribbean. The study attempted to separate the effects of UV-A from those of UV-B. In the laboratory, algal turf assemblages exposed to simulated solar UV radiation produced 55.1% less biomass than assemblages that were not exposed to UV. Assemblages not exposed to UV were dominated by Ectocarpus rhodochondroides, whereas in the assemblage developing under high UV radiation, Enteromorpha prolifera and eventually Schizothrix calcicola dominated. Lower UV-B irradiances caused a proportional reduction in biomass production and had less pronounced effects on species composition. UV-A did not have any significant effects on either algal turf productivity or community structure. In the field, assemblages exposed to naturally occurring solar UV supported a biomass 40% lower than that of assemblages protected from UV-B exposure. Once again, UV-A did not inhibit algal turf productivity

  18. Fungal infection intensity and zoospore output of Atelopus zeteki, a potential acute chytrid supershedder.

    Directory of Open Access Journals (Sweden)

    Graziella V Direnzo

    Full Text Available Amphibians vary in their response to infection by the amphibian-killing chytrid fungus, Batrachochytrium dendrobatidis (Bd. Highly susceptible species are the first to decline and/or disappear once Bd arrives at a site. These competent hosts likely facilitate Bd proliferation because of ineffective innate and/or acquired immune defenses. We show that Atelopus zeteki, a highly susceptible species that has undergone substantial population declines throughout its range, rapidly and exponentially increases skin Bd infection intensity, achieving intensities that are several orders of magnitude greater than most other species reported. We experimentally infected individuals that were never exposed to Bd (n = 5 or previously exposed to an attenuated Bd strain (JEL427-P39; n = 3. Within seven days post-inoculation, the average Bd infection intensity was 18,213 zoospores (SE: 9,010; range: 0 to 66,928. Both average Bd infection intensity and zoospore output (i.e., the number of zoospores released per minute by an infected individual increased exponentially until time of death (t50 = 7.018, p<0.001, t46 = 3.164, p = 0.001, respectively. Mean Bd infection intensity and zoospore output at death were 4,334,422 zoospores (SE: 1,236,431 and 23.55 zoospores per minute (SE: 22.78, respectively, with as many as 9,584,158 zoospores on a single individual. The daily percent increases in Bd infection intensity and zoospore output were 35.4% (SE: 0.05 and 13.1% (SE: 0.04, respectively. We also found that Bd infection intensity and zoospore output were positively correlated (t43 = 3.926, p<0.001. All animals died between 22 and 33 days post-inoculation (mean: 28.88; SE: 1.58. Prior Bd infection had no effect on survival, Bd infection intensity, or zoospore output. We conclude that A. zeteki, a highly susceptible amphibian species, may be an acute supershedder. Our results can inform epidemiological models to estimate Bd outbreak probability, especially as they relate

  19. 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.

  20. Copper (II) lead (II), and zinc (II) reduce growth and zoospore release in four zoosporic true fungi from soils of NSW, Australia.

    Science.gov (United States)

    Henderson, Linda; Pilgaard, Bo; Gleason, Frank H; Lilje, Osu

    2015-07-01

    This study examined the responses of a group of four zoosporic true fungi isolated from soils in NSW Australia, to concentrations of toxic metals in the laboratory that may be found in polluted soils. All isolates showed greatest sensitivity to Cu and least sensitivity to Pb. All isolates showed significant reduction in growth at 60 ppm (0.94 mmol m(-3)) for Cu, while three declined significantly at 60 ppm (0.92 mmol m(-3)) Zn. The growth of two isolates declined significantly at 100 ppm (0.48 mmol m(-3)) Pb and one at 200 ppm (0.96 mmol m(-3)) Pb. The rate of production of zoospores for all isolates was reduced when sporangia were grown in solid PYG media with 60 ppm Cu. Three isolates significantly declined in production at 60 ppm Zn and three at 100 ppm Pb. All isolates recovered growth after incubation in solid media with 60 ppm Zn or 100 ppm Pb. Two isolates did not recover growth after incubation in 60 ppm Cu. If these metals cause similar effects in the field, Cu, Pb, and Zn contamination of NSW soils is likely to reduce biomass of zoosporic true fungi. Loss of the fungi may reduce the rate of mineralisation of soil organic matter. Copyright © 2015 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  1. Algal Biofuels | Bioenergy | NREL

    Science.gov (United States)

    biofuels and bioproducts, Algal Research (2016) Process Design and Economics for the Production of Algal cyanobacteria, Nature Plants (2015) Acid-catalyzed algal biomass pretreatment for integrated lipid and nitrogen, we can indefinitely maintain the genetic state of the sample for future research in biofuels

  2. Can fungal zoospores be the source of energy for the rumen protozoa Eudiplodinium maggii?

    Science.gov (United States)

    Miltko, Renata; Bełżecki, Grzegorz; Kowalik, Barbara; Michałowski, Tadeusz

    2014-10-01

    Results of our earlier studies showed the ability of ciliates Eudiplodinium maggii to digest and metabolize commercial chitin. The natural source of this polysaccharide in the rumen are fungi. The objectives of present research were to determine the effect of fungal zoospores on the survival and population density of E. maggii to quantify the concentration of chitin in the cells of protozoa and to examine the ability of E. maggii, to ferment chitin of fungal zoospores. The cultivation experiment showed that the survival of protozoa was shorter than 4 days when the culture medium was composed of buffer solution and lyophilized fungal spores. An enrichment of this medium with wheat gluten prolonged the survival of ciliates up to 8 days. The supplementation of the last medium with meadow hay enabled the protozoa to survive for 28 days but a positive effect was observed only during the last 8 days of experiment. The chitin content was 0.27 ng and 0.21-0.35 ng per single zoospore and ciliate, respectively. An increase in the concentration of volatile fatty acids (VFA) was found when protozoa were incubated with zoospores. The production rate of VFA was 46.3 pM/protozoan per h whereas the endogenous production did not exceed 31 pM/protozoan per h. The molar proportion of acetic acid was 77.7% and these of butyric and propionic acids-12.2 and 11.0%, respectively. The obtained results make it evident that carbohydrates present in fungal zoospores were utilized by protozoa in energy yielding processes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. A novel method for efficient and abundant production of Phytophthora brassicae zoospores on Brussels sprout leaf discs

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    Govers Francine

    2009-08-01

    Full Text Available Abstract Background Phytophthora species are notorious oomycete pathogens that cause diseases on a wide range of plants. Our understanding how these pathogens are able to infect their host plants will benefit greatly from information obtained from model systems representative for plant-Phytophthora interactions. One attractive model system is the interaction between Arabidopsis and Phytophthora brassicae. Under laboratory conditions, Arabidopsis can be easily infected with mycelial plugs as inoculum. In the disease cycle, however, sporangia or zoospores are the infectious propagules. Since the current P. brassicae zoospore isolation methods are generally regarded as inefficient, we aimed at developing an alternative method for obtaining high concentrations of P. brassicae zoospores. Results P. brassicae isolates were tested for pathogenicity on Brussels sprout plants (Brassica oleracea var. gemmifera. Microscopic examination of leaves, stems and roots infected with a GFP-tagged transformant of P. brassicae clearly demonstrated the susceptibility of the various tissues. Leaf discs were cut from infected Brussels sprout leaves, transferred to microwell plates and submerged in small amounts of water. In the leaf discs the hyphae proliferated and abundant formation of zoosporangia was observed. Upon maturation the zoosporangia released zoospores in high amounts and zoospore production continued during a period of at least four weeks. The zoospores were shown to be infectious on Brussels sprouts and Arabidopsis. Conclusion The in vitro leaf disc method established from P. brassicae infected Brussels sprout leaves facilitates convenient and high-throughput production of infectious zoospores and is thus suitable to drive small and large scale inoculation experiments. The system has the advantage that zoospores are produced continuously over a period of at least one month.

  4. Antioxidant and antimicrobial activities of Padina pavonica and Enteromorpha sp. from the Tunisian Mediterranean coast

    Directory of Open Access Journals (Sweden)

    Malek Besbes Hlila

    2017-08-01

    Full Text Available Objective: To examine the antioxidant and the antimicrobial activities of the marine seaweeds Padina pavonica (P. pavonica and Enteromorpha sp. from the Tunisian Mediterranean coast. Methods: The acetone and water were used for algae extraction to envisage the antimicrobial activity versus Gram-negative (Escherichia coli and Pseudomonas aeruginosa, Gram-positive bacteria (Staphylococcus aureus and Enterococcus faecalis and against four Candida. The microdilution method was used to evaluate this activity. In vitro, total phenolic content and the antioxidant activity including 1,1-diphenyl-2-picrylhydrazyl (DPPH radical scavenging and 2,2'-azino-bis-(3-ethylbenthiazoline-6-sulfonic acid (ABTS were also studied. Results: The highest amount of phenolic compound was found in the P. pavonica acetonic extract [(90.61 ± 0.11 mg catechin equivalent/g extract]. This brown algae sample demonstrated greater DPPH and ABTS radical scavenging ability potential in comparison to other green seaweed, Enteromorpha sp. The maximum antimicrobial activity was shown by the P. pavonica acetonic extract against all the pathogenic strains tested (minimum inhibitory concentrations = minimum inhibitory bactericidal = minimum inhibitory fungicidal concentrations = 0.04 mg/mL. Those activities might be due to phenolic substances present in this fraction. Conclusions: The present results highlight the possible use of P. pavonica as source of antioxidant and antimicrobial compounds.

  5. Selenylation Modification of Degraded Polysaccharide from Enteromorpha prolifera and Its Biological Activities

    Science.gov (United States)

    Lv, Haitao; Duan, Ke; Shan, Hu

    2018-04-01

    Polysaccharide extracted from Enteromorpha prolifera possessed excellent biological activities, but its molecular weight was greatly high which influenced the activity. Organic Se had higher biological activities and was safer than inorganic Se species. In the present study, Enteromorpha polysaccharide was degraded to low molecular weight by free-radical degradation method of H2O2 and ascorbic acid. By single factor and orthogonal experiments, the optimal degradation conditions were reaction time of 2 h, reaction temperature of 50°C, H2O2/ascorbic acid (n/n=1:1) concentration of 15 mmol L-1, and solid-liquid ratio of 1:50 (g mL-1). Then, the degraded polysaccharide was chemically modified to obtain its selenide derivatives by nitric acid-sodium selenite method. The selenium content was 1137.29 μg g-1, while the content of sulfate radical had no change. IR spectra indicated that the selenite ester group was formed. Degraded polysaccharide selenide was characterized and evaluated for antioxidant, antifungal and antibacterial activities. The results showed that degraded polysaccharide selenide had strong capacity of scavenging DPPH and ·OH free radical. It had significant antibacterial properties for Escherichia coli, Bacillus subtilis and Salmonella spp., and it also had significant antifungal properties for Apple anthrax. The result ascertained degradation and selenylation modification did not change the main structure of polysaccharides. It was possible that free-radical degradation was an effective way for enhancing antioxidant activity to decrease molecular weight of polysaccharides.

  6. A Myb transcription factor of Phytophthora sojae, regulated by MAP kinase PsSAK1, is required for zoospore development.

    Directory of Open Access Journals (Sweden)

    Meng Zhang

    Full Text Available PsSAK1, a mitogen-activated protein (MAP kinase from Phytophthora sojae, plays an important role in host infection and zoospore viability. However, the downstream mechanism of PsSAK1 remains unclear. In this study, the 3'-tag digital gene expression (DGE profiling method was applied to sequence the global transcriptional sequence of PsSAK1-silenced mutants during the cysts stage and 1.5 h after inoculation onto susceptible soybean leaf tissues. Compared with the gene expression levels of the recipient P. sojae strain, several candidates of Myb family were differentially expressed (up or down in response to the loss of PsSAK1, including of a R2R3-type Myb transcription factor, PsMYB1. qRT-PCR indicated that the transcriptional level of PsMYB1 decreased due to PsSAK1 silencing. The transcriptional level of PsMYB1 increased during sporulating hyphae, in germinated cysts, and early infection. Silencing of PsMYB1 results in three phenotypes: a no cleavage of the cytoplasm into uninucleate zoospores or release of normal zoospores, b direct germination of sporangia, and c afunction in zoospore-mediated plant infection. Our data indicate that the PsMYB1 transcription factor functions downstream of MAP kinase PsSAK1 and is required for zoospore development of P. sojae.

  7. Harmful Algal Blooms

    Science.gov (United States)

    Graham, Jennifer L.

    2007-01-01

    What are Harmful Algal Blooms (HABs)? Freshwater and marine harmful algal blooms (HABs) can occur anytime water use is impaired due to excessive accumulations of algae. HAB occurrence is affected by a complex set of physical, chemical, biological, hydrological, and meteorological conditions making it difficult to isolate specific causative environmental factors. Potential impairments include reduction in water quality, accumulation of malodorous scums in beach areas, algal production of toxins potent enough to poison both aquatic and terrestrial organisms, and algal production of taste-and-odor compounds that cause unpalatable drinking water and fish. HABs are a global problem, and toxic freshwater and (or) marine algae have been implicated in human and animal illness and death in over 45 countries worldwide and in at least 27 U.S. States (Yoo and others, 1995; Chorus and Bartram, 1999; Huisman and others, 2005).

  8. Harmful algal blooms

    Digital Repository Service at National Institute of Oceanography (India)

    Bhat, S.R.; PrabhaDevi; DeSouza, L.; Verlecar, X.N.; Naik, C.G.

    as harmful algal bloom. Bloom formation is a natural process and it enhances biological productivity, but turns worrisome when caused by toxic species, leading to massive fish mortalities and hazards to human health. Incidences of'red tide' are increasing...

  9. Seasonal variation in the growth responses of some chlorophytic algal flora of the Red Sea

    Directory of Open Access Journals (Sweden)

    Abid Ali Ansari

    2017-06-01

    Full Text Available Seasonal variation in growth responses and antioxidant activities of four chlorophytic algal species, namely Ulva lactuca, Enteromorpha flexuoca, Cladophora prolifera, Chaetomorpha linum was investigated. Seasonal variation in the physico-chemical characteristics of water at the study site of the Red Sea was also determined. A significant variation was observed in water quality parameters in different seasons. All the algal species show higher accumulation of photosynthetic and accessory pigments in July and October and a significant decrease in January. Higher NPK content in all the four algal species was recorded in July, however, the contents were low in other months. Total protein contents were higher in July and October. Total carbohydrates in U. lactuca and E. flexuoca were significantly higher in July but in the other two species, C. prolifera and C. linum, maximum accumulation was observed in October. Antioxidant activities in all the species were most significant in January as compared to the other months. All the chlorphytic algae show prominent growth responses and antioxidant activities and are better adapted to changing climatic conditions. Due to their prompt responses even to minor changes in aquatic environment, they can be used as ecological indicators in coastal marine ecosystems.

  10. Adsorption Studies of Lead by Enteromorpha Algae and Its Silicates Bonded Material

    Directory of Open Access Journals (Sweden)

    Hassan H. Hammud

    2014-01-01

    Full Text Available Lead adsorption by green Enteromorpha algae was studied. Adsorption capacity was 83.8 mg/g at pH 3.0 with algae (E and 1433.5 mg/g for silicates modified algae (EM. FTIR and thermal analysis of algae materials were studied. Thomas and Yoon-Nelson column model were best for adsorbent (E and algae after reflux (ER and Yan model for (EM with capacity 76.2, 71.1, and 982.5 mg/g, respectively. (ER and (EM show less swelling and better flow rate control than (E. Nonlinear methods are more appropriate technique. Error function calculations proved valuable for predicting the best adsorption isotherms, kinetics, and column models.

  11. Genetic analysis of floating Enteromorpha prolifera in the Yellow Sea with AFLP marker

    Science.gov (United States)

    Liu, Cui; Zhang, Jing; Sun, Xiaoyu; Li, Jian; Zhang, Xi; Liu, Tao

    2011-09-01

    Extremely large accumulation of green algae Enteromorpha prolifera floated along China' coastal region of the Yellow Sea ever since the summer of 2008. Amplified Fragment Length Polymorphism (AFLP) analysis was applied to assess the genetic diversity and relationships among E. prolifera samples collected from 9 affected areas of the Yellow Sea. Two hundred reproducible fragments were generated with 8 AFLP primer combinations, of which 194 (97%) were polymorphic. The average Nei's genetic diversity, the coefficiency of genetic differentiation (Gst), and the average gene flow estimated from Gst in the 9 populations were 0.4018, 0.6404 and 0.2807 respectively. Cluster analysis based on the unweighed pair group method with arithmetic averages (UPGMA) showed that the genetic relationships within one population or among different populations were all related to their collecting locations and sampling time. Large genetic differentiation was detected among the populations. The E. prolifera originated from different areas and were undergoing a course of mixing.

  12. Stability of Cucumber Necrosis Virus at the Quasi-6-Fold Axis Affects Zoospore Transmission.

    Science.gov (United States)

    Sherman, Michael B; Kakani, Kishore; Rochon, D'Ann; Jiang, Wen; Voss, Neil R; Smith, Thomas J

    2017-10-01

    Cucumber necrosis virus (CNV) is a member of the genus Tombusvirus and has a monopartite positive-sense RNA genome. CNV is transmitted in nature via zoospores of the fungus Olpidium bornovanus As with other members of the Tombusvirus genus, the CNV capsid swells when exposed to alkaline pH and EDTA. We previously demonstrated that a P73G mutation blocks the virus from zoospore transmission while not significantly affecting replication in plants (K. Kakani, R. Reade, and D. Rochon, J Mol Biol 338:507-517, 2004, https://doi.org/10.1016/j.jmb.2004.03.008). P73 lies immediately adjacent to a putative zinc binding site (M. Li et al., J Virol 87:12166-12175, 2013, https://doi.org/10.1128/JVI.01965-13) that is formed by three icosahedrally related His residues in the N termini of the C subunit at the quasi-6-fold axes. To better understand how this buried residue might affect vector transmission, we determined the cryo-electron microscopy structure of wild-type CNV in the native and swollen state and of the transmission-defective mutant, P73G, under native conditions. With the wild-type CNV, the swollen structure demonstrated the expected expansion of the capsid. However, the zinc binding region at the quasi-6-fold at the β-annulus axes remained intact. By comparison, the zinc binding region of the P73G mutant, even under native conditions, was markedly disordered, suggesting that the β-annulus had been disrupted and that this could destabilize the capsid. This was confirmed with pH and urea denaturation experiments in conjunction with electron microscopy analysis. We suggest that the P73G mutation affects the zinc binding and/or the β-annulus, making it more fragile under neutral/basic pH conditions. This, in turn, may affect zoospore transmission. IMPORTANCE Cucumber necrosis virus (CNV), a member of the genus Tombusvirus , is transmitted in nature via zoospores of the fungus Olpidium bornovanus While a number of plant viruses are transmitted via insect vectors

  13. Fate of Enteromorpha flexuosa (Wulfen) J. Agardh and its spores in darkness: Implications for ballast water management

    Digital Repository Service at National Institute of Oceanography (India)

    Kolwalkar, J.P.; Sawant, S.S.; Dhargalkar, V.K.

    of Enteromorpha flexuosa (Wulfen) J. Agardh and its spores in darkness: Implications for ballast water management Janhavi P. Kolwalkar, Subhash S. Sawant* and Vinod K. Dhargalkar National Institute of Oceanography, Dona Paula, Goa. 403004 ? India... is controlled by natural events. However, once in the dark ballast tanks, their ambient environment is altered. The information on the fate of such organisms during extended incubation in dark and their potential to thrive in new environment is of great...

  14. Comparative study on adsorption of crude oil and spent engine oil from seawater and freshwater using algal biomass.

    Science.gov (United States)

    Boleydei, Hamid; Mirghaffari, Nourollah; Farhadian, Omidvar

    2018-05-15

    Efficiency of a biosorbent prepared from the green macroalga Enteromorpha intestinalis biomass for decontamination of seawater and freshwater polluted by crude oil and engine spent oil was compared. The effect of different experimental conditions including contact time, pH, particle size, initial oil concentration, and biosorbent dose on the oil biosorption was studied in the batch method. The biosorbent was characterized by CHNOS, FTIR, and SEM analysis. The experimental data were well fitted to the pseudo-second-order kinetic model and the Langmuir adsorption isotherm model. Based on the obtained results, the adsorption of spent oil with higher viscosity was better than crude oil. The biosorption of oil hydrocarbons from seawater was more efficient than freshwater. The algal biomasses which are abundantly available could be effectively used as a low-cost and environmentally friendly adsorbent for remediation of oil spill in the marine environments or in the water and wastewater treatment.

  15. Inhibitory effects of Enteromorpha linza polysaccharide on micronucleus of Allium sativum root cells.

    Science.gov (United States)

    Zhang, Zhongshan; Wang, Xiaomei; Li, Jingfen; Liu, Chongbin; Zhang, Quanbin

    2016-06-01

    In this study, the antimutagenic function of the polysaccharide from Enteromorpha linza with the micronucleus test of Allium sativum root cells induced by sulfur dioxide and ultraviolet was studied. The concentration-effect relation of the two inducers was firstly evaluated. The results showed that an increase of genotoxicity damage was demonstrated and micronuclei frequency induced by sulfur dioxide and ultraviolet displayed dose dependent increases. All the doses of polysaccharide did affect the micronuclei frequency formation compared with the negative control. And also, the significant increase in inhibition rate of micronuclei frequency was observed with the increase of the dose of polysaccharide. It was showed maximum inhibition of micronuclei frequency cells (71.74% and 66.70%) at a concentration of 200g/mL in three experiments. The low molecular weight polysaccharide showed higher inhibition rate than raw polysaccharide at the higher concentration (50g/mL) in the absence of sulfur dioxide and ultraviolet. It was confirmed to be a good mutant inhibitor. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Exploiting bilosomes for delivering bioactive polysaccharide isolated from Enteromorpha intestinalis for hacking hepatocellular carcinoma.

    Science.gov (United States)

    Matloub, Azza Abdelmageed; Salama, Alaa Hamed; Aglan, Hadeer Ahmed; AbouSamra, Mona Mahmoud; ElSouda, Sahar Salah Mohamed; Ahmed, Hanaa Hamdy

    2018-04-01

    Bile salts containing vesicles (bilosomes) represent a portentous vesicular carrier that showed prosperous results in delivering active moieties in the gastrointestinal tract (GIT). In this study, bilosomes were exploited to deliver sulfated polysaccharide-protein complexes of Enteromorpha intestinalis (EHEM) and enhance its activity against hepatocellular carcinoma as well as resist harsh GIT conditions. Bilosomes were prepared using the sodium salt of three different bile acids (cholic, deoxycholic, taurodeoxycholic) and two different nonionic surfactants (Span 40 and 65). The effects of experimental variables were thoroughly studied to obtain an optimum formulation loading EHEM. The selected formulation (EH-Bilo-2) prepared with sodium cholate and Span 65 displayed nano-sized (181.1 ± 16.80 nm) spherical vesicles with reasonable entrapment efficiency (71.60 ± 0.25%) and controlled release properties; and thus was investigated as anti-hepatocarcinogenic candidate for in vivo studies. Treatment of hepatocellular carcinoma (HCC) bearing rats with EH-Bilo-2 experienced significant decrease in serum α-fetoprotein, endoglin, lipocalin-2, and heat shock protein 70 levels vs. the untreated counterparts. Furthermore, the photomicrographs of their liver tissue sections showed focal area of degenerated pleomorphic hepatocytes with fine fibrosis originating from the portal area. Thus, the optimized bilosomal formulation is a promising delegate for tackling hepatocellular carcinoma owing to its powerful anti-cancer and anti-angiogenic activity.

  17. Enteromorpha intestinalis Derived Seaweed Liquid Fertilizers as Prospective Biostimulant for Glycine max

    Directory of Open Access Journals (Sweden)

    Chetna Mathur

    2015-12-01

    Full Text Available ABSTRACT In the present study, the potential of seaweed liquid fertilizer (SLF of marine algae Enteromorpha intestinalis was evaluated for its effect on seed germination, yield, biochemical parameters and pigment characteristics of Glycine maxE. intestinalis was collected form Mandapam coast of Gulf of Mannar, Tamil Nadu, and the dried seaweeds were used for the preparation of SLF. G. max seeds were germinated with four different concentrations (20, 40, 60, and 100% of SLF; its growth and yield parameters were evaluated and compared with chemical fertilizer and control. The morphological and bio-chemical parameters such as seed germination (100%, root (6.6cm and shoot length (5.4 cm, carbohydrates (0.098 mg/g, protein (0.56 mg/g, pigment (0.444 mg/g chl a; 1.073 mg/g chl b; 3.70 mg/g carotenoids of the plant was found maximum at a concentration of 60% SLF. The phenol content (3.25 mg/g was maximum in 40% SLF. The GC-MS analysis of SLF revealed the presence of notable benzoic compounds involved in plant growth promotion. Results showed thatE. intestinalis derived SLF was potential biostimulant forG. max. Thus, marine algae based fertilizer could be an effective and alternate to the chemical fertilizers emphasizing the need for systematic evaluation programme for SLF on various crops.

  18. Use of the vital stain FUN-1 indicates viability of Phytophthora capsici propagules and can be used to predict maximum zoospore production.

    Science.gov (United States)

    Lewis Ivey, Melanie L; Miller, Sally A

    2014-01-01

    The fluorescent vital dye FUN®-1 (2-chloro-4-[2,3-dihydro-3-methyl-{benzo-1,3-thiazol-2-yl}-methylidene]-1-phenylquinolinium iodide) was evaluated as a tool to assess Phytophthora capsici sporangia and zoospore metabolic activity and viability. Under aerobic conditions, mycelia, sporangia and zoospores cultured on agar medium and stained with FUN-1 exhibited red fluorescent cylindrical intravacuolar structures (CIVS) that were clearly visible at 100× magnification. Encysted zoospores did not exhibit CIVS after exposure to FUN-1 dye. Over 7 d there was a significant reduction in the percent of sporangia containing CIVS, which corresponded with a significant increase in zoospore formation and release. The decline in the percentage of metabolically active sporangia and increase in the number of zoospores fit both a linear and log regression model. The FUN-1 dye was suitable for distinguishing between live and dead sporangia and effective in monitoring the change in metabolic activity of sporangia over time. It will be useful in determining parameters, including P. capsici culture age, that maximize production of zoospores in vitro.

  19. 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.

  20. 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

  1. Direct hydrothermal liquefaction of undried macroalgae Enteromorpha prolifera using acid catalysts

    International Nuclear Information System (INIS)

    Yang, Wenchao; Li, Xianguo; Liu, Shishi; Feng, Lijuan

    2014-01-01

    Highlights: • Bio-oil from liquefaction of wet E. prolifera was as feasible as dry powder. • Adding acid catalysts could improve the flow property of bio-oil. • Alkenes in the bio-oil converted to ketones in the presence of acid catalysts. • Content of 5-methyl furfural increased in the bio-oil obtained with acid catalysts. • Esters were formed in the bio-oil when adding sulfuric acid as a catalyst. - Abstract: Direct liquefaction of macroalgae Enteromorpha prolifera without predrying treatment was performed in a batch reactor. Effects of temperature, reaction time, biomass-to-water ratio and acid catalysts (sulfuric acid and acetic acid) on liquefaction products were investigated. Raw material and liquefaction products were analyzed by elemental analysis, Fourier transform infrared (FT-IR) and gas chromatography–mass spectrometry (GC–MS). Results showed that liquefaction at 290 °C for 20 min with 1:3 biomass-to-water ratio produced the highest bio-oil yield of 28.4 wt%, and high heating value (HHV) was 29.5 MJ/kg. Main components of bio-oil were fatty acids, ketones, alkenes and 5-methyl furfural, and main components of water soluble organics (WSOs) were pyridines, carboxylic acids and glycerol. In the bio-oil obtained with acid catalysts, content of ketones significantly increased while alkenes disappeared. Content of 5-methyl furfural also increased. Flow property of bio-oils was improved in the presence of acid catalysts. Moreover, esters were formed when adding sulfuric acid

  2. Thermal cracking of Enteromorpha prolifera with solvents to bio-oil

    International Nuclear Information System (INIS)

    Song, Linhua; Hu, Mingming; Liu, Dong; Zhang, Daoxiang; Jiang, Cuiyu

    2014-01-01

    Highlights: • Thermal cracking of EP gave rise to a maximum bio-oil yield of 27.4 wt.% at 340 °C and 40 min. • The maximum liquid yield of EP/ethonal is 36.7 wt.% at 300 °C and 30 min. • The maximum liquid yield of EP/VGO is 90.5 wt.% at 300 °C and 30 min. • The HHV of bio-oil from thermal cracking of EP/VGO is 44.51 MJ/kg. • This process has the potential for industrial production of bio-oil from EP. - Abstract: Enteromorpha prolifera (EP) is a renewable energy source that was evaluated as a feedstock to produce bio-oil by thermal cracking. Harvesting EP for bio-oil production will also reduce the damage of green tide on ocean ecology. Effects of reaction temperature between 220 and 380 °C and reaction time between 20 and 80 min on the bio-oil yield and gas and solid thermal cracking products were investigated. Effects of solvents (i.e., ethanol and vacuum gas oil (VGO)) on the yields of bio-oil, gas and solid were also studied. EP, VGO and products from thermal cracking were analyzed by elemental analysis, gas chromatography–mass spectra and gas chromatography. Results indicate that thermal cracking of EP with VGO (EP/VGO) gave rise to the maximum bio-oil yield of 90.5% at 300 °C with a reaction time of 30 min. Higher heating values and elemental analysis demonstrate that this process has the potential for industrial production of bio-oil from EP

  3. Algal dermatitis in cichlids.

    Science.gov (United States)

    Yanong, Roy P E; Francis-Floyd, Ruth; Curtis, Eric; Klinger, Ruth Ellen; Cichra, Mary E; Berzins, Ilze K

    2002-05-01

    Three varieties of a popular African cichlid aquarium species, Pseudotropheus zebra, from 2 tropical fish farms in east central Florida were submitted for diagnostic evaluation because of the development of multifocal green lesions. The percentage of infected fish in these populations varied from 5 to 60%. Fish were otherwise clinically normal. Microscopic examination of fresh and fixed lesions confirmed algal dermatitis, with light invasion of several internal organs in each group. A different alga was identified from each farm. Fish from farm A were infected with Chlorochytrium spp, whereas fish from farm B were infected with Scenedesmus spp. Because of the numbers of fish involved, bath treatments to remove the algae from affected fish from farm B were attempted, with different dosages of several common algaecides including copper sulfate pentahydrate, diuron, and sodium chloride. However, none of these treatments were successful, possibly because of the location of the algae under the scales and within the dermis, and also because of the sequestering effect of the granulomatous response. To our knowledge, this is the first report of algal dermatitis in ornamental cichlids, as well as the first report of Scenedesmus spp infection in any fish.

  4. The effects of nitric oxide in settlement and adhesion of zoospores of the green alga Ulva.

    Science.gov (United States)

    Thompson, Stephanie E M; Callow, Maureen E; Callow, James A

    2010-01-01

    Previous studies have shown that elevated nitric oxide (NO) reduces adhesion in diatom, bacterial and animal cells. This article reports experiments designed to investigate whether elevated NO reduces the adhesion of zoospores of the green alga Ulva, an important fouling species. Surface-normalised values of NO were measured using the fluorescent indicator DAF-FM DA and parallel hydrodynamic measurements of adhesion strength were made. Elevated levels of NO caused by the addition of the exogenous NO donor SNAP reduced spore settlement by 20% and resulted in lower adhesion strength. Addition of the NO scavenger cPTIO abolished the effects of SNAP on adhesion. The strength of attachment and NO production by spores in response to four coatings (Silastic T2; Intersleek 700; Intersleek 900 and polyurethane) shows that reduced adhesion is correlated with an increase in NO production. It is proposed that in spores of Ulva, NO is used as an intracellular signalling molecule to detect how conducive a surface is for settlement and adhesion. The effect of NO on the adhesion of a range of organisms suggests that NO-releasing coatings could have the potential to control fouling.

  5. Determining baseline element composition of lichens. II. Hypogymnia enteromorpha and Usnea spp. at Redwood National Park, California

    Science.gov (United States)

    Gough, L.P.; Jackson, L.L.; Sacklin, J.A.

    1988-01-01

    Hypogymnia enteromorpha and Usnea spp. were collected in the Little Bald Hills ultramafic region of Redwood National Park, California, to establish element-concentration norms. Baselines are presented for Ba, Ca, Cu, Mn, Ni, P, Sr, V, and Zn for both lichen species; for Li, Mg, and K for H. enteromorpha; and for Al, Ce, Cr, Co, Fe, Na, and Ti for Usnea. Element concentrations of future collections of this same material can be used to monitor possible air quality changes anticipated from mining activities planned nearby. The variability in the element concentrations was partitioned between geographical distance increments and sample preparation and analysis procedures. In general, most of this variability was found in samples less than a few hundreds of meters apart rather than those at about 1 km apart. Therefore, except for Ba and Co, no large geographical element-concentration trends were observed. Samples of both species contained elevated levels of Ni and Mg, which probably reflect the ultramafic terrain over which they occur.

  6. Climate Change and Algal Blooms =

    Science.gov (United States)

    Lin, Shengpan

    Algal blooms are new emerging hazards that have had important social impacts in recent years. However, it was not very clear whether future climate change causing warming waters and stronger storm events would exacerbate the algal bloom problem. The goal of this dissertation was to evaluate the sensitivity of algal biomass to climate change in the continental United States. Long-term large-scale observations of algal biomass in inland lakes are challenging, but are necessary to relate climate change to algal blooms. To get observations at this scale, this dissertation applied machine-learning algorithms including boosted regression trees (BRT) in remote sensing of chlorophyll-a with Landsat TM/ETM+. The results show that the BRT algorithm improved model accuracy by 15%, compared to traditional linear regression. The remote sensing model explained 46% of the total variance of the ground-measured chlorophyll- a in the first National Lake Assessment conducted by the US Environmental Protection Agency. That accuracy was ecologically meaningful to study climate change impacts on algal blooms. Moreover, the BRT algorithm for chlorophyll- a would not have systematic bias that is introduced by sediments and colored dissolved organic matter, both of which might change concurrently with climate change and algal blooms. This dissertation shows that the existing atmospheric corrections for Landsat TM/ETM+ imagery might not be good enough to improve the remote sensing of chlorophyll-a in inland lakes. After deriving long-term algal biomass estimates from Landsat TM/ETM+, time series analysis was used to study the relations of climate change and algal biomass in four Missouri reservoirs. The results show that neither temperature nor precipitation was the only factor that controlled temporal variation of algal biomass. Different reservoirs, even different zones within the same reservoir, responded differently to temperature and precipitation changes. These findings were further

  7. 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...

  8. Removal of lead from aqueous solution by activated carbon prepared from Enteromorpha prolifera by zinc chloride activation

    Energy Technology Data Exchange (ETDEWEB)

    Li Yanhui, E-mail: liyanhui@tsinghua.org.cn [Laboratory of Fiber Materials and Modern Textile, Growing Base for State Key Laboratory, Qingdao University, 308 Ningxia Road, Qingdao 266071 (China); College of Electromechanical Engineering, Qingdao University, 308 Ningxia Road, Qingdao 266071 (China); Du Qiuju [Laboratory of Fiber Materials and Modern Textile, Growing Base for State Key Laboratory, Qingdao University, 308 Ningxia Road, Qingdao 266071 (China); Wang Xiaodong [College of Electromechanical Engineering, Qingdao University, 308 Ningxia Road, Qingdao 266071 (China); Zhang Pan [Laboratory of Fiber Materials and Modern Textile, Growing Base for State Key Laboratory, Qingdao University, 308 Ningxia Road, Qingdao 266071 (China); Wang Dechang [College of Electromechanical Engineering, Qingdao University, 308 Ningxia Road, Qingdao 266071 (China); Wang Zonghua; Xia Yanzhi [Laboratory of Fiber Materials and Modern Textile, Growing Base for State Key Laboratory, Qingdao University, 308 Ningxia Road, Qingdao 266071 (China)

    2010-11-15

    Activated carbon was prepared from Enteromorpha prolifera (EP) by zinc chloride activation. The physico-chemical properties of EP-activated carbon (EPAC) were characterized by thermal stability, zeta potential and Boehm titration methods. The examination showed that EPAC has a porous structure with a high surface area of 1688 m{sup 2}/g. Batch adsorption experiments were carried out to study the effect of various parameters such as initial pH, adsorbent dosage, contact time and temperature on Pb(II) ions adsorption properties by EPAC. The kinetic studies showed that the adsorption data followed a pseudo second-order kinetic model. The isotherm analysis indicated that the adsorption data can be represented by Freundlich isotherm model. Thermodynamic studies indicated that the adsorption reaction was a spontaneous and endothermic process.

  9. Removal of lead from aqueous solution by activated carbon prepared from Enteromorpha prolifera by zinc chloride activation

    International Nuclear Information System (INIS)

    Li Yanhui; Du Qiuju; Wang Xiaodong; Zhang Pan; Wang Dechang; Wang Zonghua; Xia Yanzhi

    2010-01-01

    Activated carbon was prepared from Enteromorpha prolifera (EP) by zinc chloride activation. The physico-chemical properties of EP-activated carbon (EPAC) were characterized by thermal stability, zeta potential and Boehm titration methods. The examination showed that EPAC has a porous structure with a high surface area of 1688 m 2 /g. Batch adsorption experiments were carried out to study the effect of various parameters such as initial pH, adsorbent dosage, contact time and temperature on Pb(II) ions adsorption properties by EPAC. The kinetic studies showed that the adsorption data followed a pseudo second-order kinetic model. The isotherm analysis indicated that the adsorption data can be represented by Freundlich isotherm model. Thermodynamic studies indicated that the adsorption reaction was a spontaneous and endothermic process.

  10. Effect of arabinogalactan proteins from the root caps of pea and Brassica napus on Aphanomyces euteiches zoospore chemotaxis and germination.

    Science.gov (United States)

    Cannesan, Marc Antoine; Durand, Caroline; Burel, Carole; Gangneux, Christophe; Lerouge, Patrice; Ishii, Tadashi; Laval, Karine; Follet-Gueye, Marie-Laure; Driouich, Azeddine; Vicré-Gibouin, Maïté

    2012-08-01

    Root tips of many plant species release a number of border, or border-like, cells that are thought to play a major role in the protection of root meristem. However, little is currently known on the structure and function of the cell wall components of such root cells. Here, we investigate the sugar composition of the cell wall of the root cap in two species: pea (Pisum sativum), which makes border cells, and Brassica napus, which makes border-like cells. We find that the cell walls are highly enriched in arabinose and galactose, two major residues of arabinogalactan proteins. We confirm the presence of arabinogalactan protein epitopes on root cap cell walls using immunofluorescence microscopy. We then focused on these proteoglycans by analyzing their carbohydrate moieties, linkages, and electrophoretic characteristics. The data reveal (1) significant structural differences between B. napus and pea root cap arabinogalactan proteins and (2) a cross-link between these proteoglycans and pectic polysaccharides. Finally, we assessed the impact of root cap arabinogalactan proteins on the behavior of zoospores of Aphanomyces euteiches, an oomycetous pathogen of pea roots. We find that although the arabinogalactan proteins of both species induce encystment and prevent germination, the effects of both species are similar. However, the arabinogalactan protein fraction from pea attracts zoospores far more effectively than that from B. napus. This suggests that root arabinogalactan proteins are involved in the control of early infection of roots and highlights a novel role for these proteoglycans in root-microbe interactions.

  11. Genetic diversity and relationships between wild and cultivated populations of the sea lettuce, Enteromorpha prolifera, in Korea revialed by RAPD markers

    OpenAIRE

    Huh, Man; Lee, Hak; Lee, Bok; Choi, Joo

    2004-01-01

    RAPD analysis was conducted to estimate genetic diversity and population structure of the wild (natural) and cultivated sea lettuce, Enteromorpha prolifera. The objectives of this study were to estimate the levels of genetic diversity in the wild and cultivated populations and to describe how the genetic variation of this species is distributed within and among its populations. In wild sea lettuce, 93.2% of loci at the species level showed polymorphism. The cultivated populations were found t...

  12. Algal stabilisation of estuarine sediments

    International Nuclear Information System (INIS)

    1992-01-01

    The presence of benthic microalgae can increase the stability of intertidal sediments and influence sediment fluxes within an estuarine environment. Therefore the relative importance of algal stabilisation needs to be understood to help predict the effects of a tidal barrage. The objectives of this study are: to assess the significance of stabilisation of sediments by algae, in relation to the changes in hydrodynamic and sedimentological regimes arising from the construction of tidal power barrages; to identify a reliable and meaningful method of measuring the effectiveness, including duration, of algal binding on sediment stability, and to relate this method to other methods of measuring critical erosion velocity and sediment shear strength; to undertake a series of field experiments investigating the effect of algae on binding sediments and the parameters which could potentially influence such binding and to develop a predictive method for the assessment of sediment stabilisation by algal binding. This report contains plates, figures and tables. (author)

  13. Algal stabilisation of estuarine sediments

    International Nuclear Information System (INIS)

    1992-01-01

    The presence of benthic microalgae can increase the stability of intertidal sediments and influence sediment fluxes within an estuarine environment. Therefore the relative importance of algal stabilisation needs to be understood to help predict the effects of a tidal barrage. The biogenic stabilisation of intertidal estuarine sediments by epipelic diatom films and the macrophyte Vaucheria was studied at three sites on the Severn Estuary. The cohesive strength meter (CSM) was developed to measure surface critical shear stress with varied algal density. A number of techniques have been used to determine the general in situ erodibility of cohesive estuarine sediments. The measurements of sediment shear strength and critical erosion velocity were investigated. Field experiments were undertaken to investigate the effect of algae on binding sediments, and a predictive method for the assessment of sediment stabilisation by algal binding was developed. (author)

  14. Characterization of Amoeboaphelidium protococcarum, an algal parasite new to the cryptomycota isolated from an outdoor algal pond used for the production of biofuel.

    Directory of Open Access Journals (Sweden)

    Peter M Letcher

    Full Text Available Mass culture of algae for the production of biofuels is a developing technology designed to offset the depletion of fossil fuel reserves. However, large scale culture of algae in open ponds can be challenging because of incidences of infestation with algal parasites. Without knowledge of the identity of the specific parasite and how to control these pests, algal-based biofuel production will be limited. We have characterized a eukaryotic parasite of Scenedesmus dimorphus growing in outdoor ponds used for biofuel production. We demonstrated that as the genomic DNA of parasite FD01 increases, the concentration of S. dimorphus cells decreases; consequently, this is a highly destructive pathogen. Techniques for culture of the parasite and host were developed, and the endoparasite was identified as the Aphelidea, Amoeboaphelidium protococcarum. Phylogenetic analysis of ribosomal sequences revealed that parasite FD01 placed within the recently described Cryptomycota, a poorly known phylum based on two species of Rozella and environmental samples. Transmission electron microscopy demonstrated that aplanospores of the parasite produced filose pseudopodia, which contained fine fibers the diameter of actin microfilaments. Multiple lipid globules clustered and were associated with microbodies, mitochondria and a membrane cisternae, an arrangement characteristic of the microbody-lipid globule complex of chytrid zoospores. After encystment and attachment to the host cells, the parasite injected its protoplast into the host between the host cell wall and plasma membrane. At maturity the unwalled parasite occupied the entire host cell. After cleavage of the protoplast into aplanospores, a vacuole and lipids remained in the host cell. Amoeboaphelidium protococcarum isolate FD01 is characteristic of the original description of this species and is different from strain X-5 recently characterized. Our results help put a face on the Cryptomycota, revealing that the

  15. Characterization of Amoeboaphelidium protococcarum, an Algal Parasite New to the Cryptomycota Isolated from an Outdoor Algal Pond Used for the Production of Biofuel

    Science.gov (United States)

    Letcher, Peter M.; Lopez, Salvador; Schmieder, Robert; Lee, Philip A.; Behnke, Craig; Powell, Martha J.; McBride, Robert C.

    2013-01-01

    Mass culture of algae for the production of biofuels is a developing technology designed to offset the depletion of fossil fuel reserves. However, large scale culture of algae in open ponds can be challenging because of incidences of infestation with algal parasites. Without knowledge of the identity of the specific parasite and how to control these pests, algal-based biofuel production will be limited. We have characterized a eukaryotic parasite of Scenedesmus dimorphus growing in outdoor ponds used for biofuel production. We demonstrated that as the genomic DNA of parasite FD01 increases, the concentration of S. dimorphus cells decreases; consequently, this is a highly destructive pathogen. Techniques for culture of the parasite and host were developed, and the endoparasite was identified as the Aphelidea, Amoeboaphelidium protococcarum. Phylogenetic analysis of ribosomal sequences revealed that parasite FD01 placed within the recently described Cryptomycota, a poorly known phylum based on two species of Rozella and environmental samples. Transmission electron microscopy demonstrated that aplanospores of the parasite produced filose pseudopodia, which contained fine fibers the diameter of actin microfilaments. Multiple lipid globules clustered and were associated with microbodies, mitochondria and a membrane cisternae, an arrangement characteristic of the microbody-lipid globule complex of chytrid zoospores. After encystment and attachment to the host cells, the parasite injected its protoplast into the host between the host cell wall and plasma membrane. At maturity the unwalled parasite occupied the entire host cell. After cleavage of the protoplast into aplanospores, a vacuole and lipids remained in the host cell. Amoeboaphelidium protococcarum isolate FD01 is characteristic of the original description of this species and is different from strain X-5 recently characterized. Our results help put a face on the Cryptomycota, revealing that the phylum is more

  16. 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

  17. An efficient method for zoospore production, infection and real-time quantification of Phytophthora cajani causing Phytophthora blight disease in pigeonpea under elevated atmospheric CO₂.

    Science.gov (United States)

    Sharma, Mamta; Ghosh, Raju; Tarafdar, Avijit; Telangre, Rameshwar

    2015-03-25

    Phytophthora blight caused by Phytophthora cajani is an emerging disease of pigeonpea (Cajanus cajan L.) affecting the crop irrespective of cropping system, cultivar grown and soil types. Current detection and identification methods for Phytophthora species rely primarily on cultural and morphological characteristics, the assessment of which is time-consuming and not always suitable. Sensitive and reliable methods for isolation, identification, zoospore production and estimating infection severity are therefore desirable in case of Phytophthora blight of pigeonpea. In this study, protocols for isolation and identification of Phytophthora blight of pigeonpea were standardized. Also the method for zoospore production and in planta infection of P. cajani was developed. Quantification of fungal colonization by P. cajani using real-time PCR was further standardized. Phytophthora species infecting pigeonpea was identified based on mycological characters such as growth pattern, mycelium structure and sporangial morphology of the isolates and confirmed through molecular characterization (sequence deposited in GenBank). For Phytophthora disease development, zoospore suspension of 1 × 10(5) zoospores per ml was found optimum. Phytophthora specific real-time PCR assay was developed using specific primers based on internal transcribed spacer (ITS) 1 and 2. Use of real-time PCR allowed the quantitative estimation of fungal biomass in plant tissues. Detection sensitivities were within the range of 0.001 pg fungal DNA. A study to see the effect of elevated CO₂ on Phytophthora blight incidence was also conducted which indicated no significant difference in disease incidence, but incubation period delayed under elevated CO₂ as compared to ambient level. The zoospore infection method for Phytophthora blight of pigeonpea will facilitate the small and large scale inoculation experiments and thus devise a platform for rapid and reliable screening against Phytophthora blight

  18. 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.

  19. Effects of ultraviolet radiation and temperature on the ultrastructure of zoospores of the brown macroalga Laminaria hyperborea.

    Science.gov (United States)

    Steinhoff, F S; Wiencke, C; Müller, R; Bischof, K

    2008-05-01

    The interactive effects of an 8 h exposure to UV radiation and altered temperatures on the ultrastructure and germination of zoospores of the sublittoral brown alga Laminaria hyperborea (Gunn.) Foslie were investigated for the first time. Spores were exposed to four temperatures (2, 7, 12 and 17 degrees C) and three light regimes (PAR, PAR + UV-A, PAR + UV-A+UV-B). Freshly-released spores of L. hyperborea lack a cell wall and contain a nucleus with fine granular nucleoplasm and a nucleolus, one chloroplast, several mitochondria, dictyosomes and an endoplasmatic reticulum. Further, several kinds of so-called adhesive vesicles, lipid globuli and physodes containing UV-absorbing phlorotannins are embedded in the cytoplasm. No eye-spot is present. Physodes were found but they were rare and small. After an 8 h exposure to UV-B, the nucleoplasm had a mottled structure, chloroplasts contained plastoglobuli, the structure of the mitochondria changed from crista- to sacculus-type and germination was strongly inhibited at all temperatures. UV-A only had an impact on the ultrastructure at the highest temperature tested. The strongest effects were found at 17 degrees C, where germination was reduced to 35%, 32% and 9% after exposure to PAR, PAR+UV-A and PAR + UV-A + UV-B, respectively. This study indicates that UV-B radiation has strong damaging effects on the physiology and ultrastructure of zoospores of L. hyperborea. The results are important for developing scenarios for the effect of enhanced UV radiation and increasing temperatures caused by global climate changes.

  20. Antibacterial Activity and Action Mechanism of the Essential Oil from Enteromorpha linza L. against Foodborne Pathogenic Bacteria

    Directory of Open Access Journals (Sweden)

    Jayanta Kumar Patra

    2016-03-01

    Full Text Available Foodborne illness and disease caused by foodborne pathogenic bacteria is continuing to increase day by day and it has become an important topic of concern among various food industries. Many types of synthetic antibacterial agents have been used in food processing and food preservation; however, they are not safe and have resulted in various health-related issues. Therefore, in the present study, essential oil from an edible seaweed, Enteromorpha linza (AEO, was evaluated for its antibacterial activity against foodborne pathogens, along with the mechanism of its antibacterial action. AEO at 25 mg/disc was highly active against Bacillus cereus (12.3–12.7 mm inhibition zone and Staphylococcus aureus (12.7–13.3 mm inhibition zone. The minimum inhibitory concentration and minimum bactericidal concentration values of AEO ranged from 12.5–25 mg/mL. Further investigation of the mechanism of action of AEO revealed its strong impairing effect on the viability of bacterial cells and membrane permeability, as indicated by a significant increase in leakage of 260 nm absorbing materials and K+ ions from the cell membrane and loss of high salt tolerance. Taken together, these data suggest that AEO has the potential for use as an effective antibacterial agent that functions by impairing cell membrane permeability via morphological alternations, resulting in cellular lysis and cell death.

  1. Dietary Polysaccharide from Enteromorpha Clathrata Modulates Gut Microbiota and Promotes the Growth of Akkermansia muciniphila, Bifidobacterium spp. and Lactobacillus spp.

    Science.gov (United States)

    Shang, Qingsen; Wang, Ya; Pan, Lin; Niu, Qingfeng; Li, Chao; Jiang, Hao; Cai, Chao; Hao, Jiejie; Li, Guoyun; Yu, Guangli

    2018-05-17

    Recently, accumulating evidence has suggested that Enteromorpha clathrata polysaccharide (ECP) could contribute to the treatment of diseases. However, as a promising candidate for marine drug development, although ECP has been extensively studied, less consideration has been given to exploring its effect on gut microbiota. In this light, given the critical role of gut microbiota in health and disease, we investigated here the effect of ECP on gut microbiota using 16S rRNA high-throughput sequencing. As revealed by bioinformatic analyses, ECP considerably changed the structure of the gut microbiota and significantly promoted the growth of probiotic bacteria in C57BL/6J mice. However, interestingly, ECP exerted different effects on male and female microbiota. In females, ECP increased the abundances of Bifidobacterium spp. and Akkermansia muciniphila , a next-generation probiotic bacterium, whereas in males, ECP increased the population of Lactobacillus spp. Moreover, by shaping a more balanced structure of the microbiota, ECP remarkably reduced the antigen load from the gut in females. Altogether, our study demonstrates for the first time a prebiotic effect of ECP on gut microbiota and forms the basis for the development of ECP as a novel gut microbiota modulator for health promotion and disease management.

  2. 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. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. The effect of rumen ciliates on chitinolytic activity, chitin content and the number of fungal zoospores in the rumen fluid of sheep.

    Science.gov (United States)

    Miltko, Renata; Bełżecki, Grzegorz; Herman, Andrzej; Kowalik, Barbara; Skomiał, Jacek

    2016-12-01

    The objective of this study was to investigate the effect of selected protozoa on the degradation and concentration of chitin and the numbers of fungal zoospores in the rumen fluid of sheep. Three adult ewes were fed a hay-concentrate diet, defaunated, then monofaunated with Entodinium caudatum or Diploplastron affine alone and refaunated with natural rumen fauna. The average density of the protozoa population varied from 6.1 · 10(4) (D. affine) to 42.2 · 10(4) cells/ml rumen fluid (natural rumen fauna). The inoculation of protozoa in the rumen of defaunated sheep increased the total activity of chitinolytic enzymes from 2.9 to 3.6 μmol N-acetylglucosamine/g dry matter (DM) of rumen fluid per min, the chitin concentration from 6.3 to 7.2 mg/g DM of rumen fluid and the number of fungal zoospores from 8.1 to 10.9 · 10(5) cells/ml rumen fluid. All examined indices showed diurnal variations. Ciliate population density was highest immediately prior to feeding and lowest at 4 h thereafter. The opposite effects were observed for the numbers of fungal zoospores, the chitin concentration and chitinolytic activity. Furthermore, it was found that chitin from zoospores may account for up to 95% of total microbial chitin in the rumen fluid of sheep. In summary, the examined ciliate species showed the ability of chitin degradation as well as a positive influence on the development of the ruminal fungal population.

  4. Clinical and Microbial Evaluation of the Effects on Gingivitis of a Mouth Rinse Containing an Enteromorpha linza Extract

    Science.gov (United States)

    Cho, Han-Bin; Lee, Hee-Hyun; Lee, Ok-Hwan; Choi, Hyeon-Son; Choi, Jae-Suk

    2011-01-01

    Abstract Enteromorpha linza, a green alga, has been recognized as a potential source of natural antimicrobial and antifungal compounds. We previously reported that an E. linza extract strongly inhibited the growth of Prevotella intermedia and Porphyromonas gingivalis. The principal objective of this study was to evaluate the clinical effect of a mouth rinse containing the E. linza extract on gingivitis disease, as measured by the plaque index (PI), gingival index (GI), and bleeding on probing (BOP), and on two bacterial strains (P. intermedia and P. gingivalis), in comparison with Listerine® (Listerine-Korea, Seoul, Korea), which was used as a positive control. In total, 55 subjects were recruited into active participation in this clinical study. The PI, GI, BOP, and bacterial strains were then evaluated over a test period of 6 weeks. After 1, 2, 4, and 6 weeks, the same clinical indices were recorded, and the levels of P. intermedia and P. gingivalis were quantified via real-time polymerase chain reaction. At the end of the study, the group using the mouth rinse containing the E. linza extract evidenced significant reductions in the clinical indices (PI, GI, and BOP) and P. gingivalis compared with baseline values. Moreover, E. linza extract containing mouth rinse produced effects similar to those of Listerine. Overall, these results indicate that a mouth rinse containing E. linza extract significantly reduces plaque, improves the condition of gingival tissues, and reduces bleeding. Additionally, E. linza extract mouth rinse significantly inhibits P. gingivalis and P. intermedia. Thus, this clinical study demonstrated that the twice-daily use of an E. linza extract mouth rinse can inhibit and prevent gingivitis. PMID:22145775

  5. Biofabrication and characterization of silver nanoparticles using aqueous extract of seaweed Enteromorpha compressa and its biomedical properties

    Directory of Open Access Journals (Sweden)

    Vijayan Sri Ramkumar

    2017-03-01

    Full Text Available Green synthesis of nanoparticles using seaweeds are fascinating high research attention nowadays and also gaining center of attention in biomedical applications. In this work, we have synthesized biocompatible and functionalized silver nanoparticles using an aqueous extract of seaweed Enteromorpha compressa as a reducing as well as stabilizing agent and their efficient antimicrobial and anticancer activity are reported here. The UV–vis spectra of AgNPs showed the characteristics SPR absorption band at 421 nm. The chemical interaction and crystalline nature of the AgNPs were evaluated by FT-IR and XRD studies. The XRD result of AgNPs shows typical Ag reflection peaks at 38.1°, 44.2°, 64.4° and 77.1° corresponding to (111, (200, (220 and (311 Bragg’s planes. The surface morphology and composition of the samples were observed by HRTEM, EDS and SAED pattern analyses. Spherical shaped Ag nano structures were observed in the size ranges between 4 and 24 nm with clear lattice fringes in the HRTEM image. This report reveals that seaweed mediated synthesis of AgNPs and sustained delivery of Ag ions to the bacterial and fungal surface have been reducing their growth rate which was evaluated by well diffusion assay. The synthesized AgNPs showed favorable cytotoxicity against Ehlrich Ascites Carcinoma (EAC cells with IC50 value was recorded at 95.35 μg mL−1. This study showed cost effective silver nanoparticles synthesis with excellent biocompatibility and thus could potentially be utilized in biomedical and pharmaceutical applications.

  6. Macromolecular synthesis in algal cells

    International Nuclear Information System (INIS)

    Ishida, M.R.; Kikuchi, Tadatoshi

    1980-01-01

    The present paper is a review of our experimental results obtained previously on the macromolecular biosyntheses in the cells of blue-green alga Anacystis nidulans as a representative species of prokaryote, and also in those of three species of eukaryotic algae, i.e. Euglena gracilis strain Z, Chlamydomonas reinhardi, and Cyanidium caldarium. In these algal cells, the combined methods consisting of pulse-labelling using 32 P, 3 H- and 14 C-labelled precursors for macromolecules, of their chasing and of the use of inhibitors which block specifically the syntheses of macromolecules such as proteins, RNA and DNA in living cells were very effectively applied for the analyses of the regulatory mechanism in biosyntheses of macromolecules and of the mode of their assembly into the cell structure, especially organelle constituents. Rased on the results obtained thus, the following conclusions are reached: (1) the metabolic pool for syntheses of macromolecules in the cells of prokaryotic blue-green alga is limited to the small extent and such activities couple largely with the photosynthetic mechanism; (2) 70 S ribosomes in the blue-green algal cells are assembled on the surface of thylakoid membranes widely distributed in their cytoplasm; and (3) the cells of eukaryotic unicellular algae used here have biochemical characters specific for already differentiated enzyme system involving in transcription and translation machineries as the same as in higher organisms, but the control mechanism concerning with such macromolecule syntheses are different among each species. (author)

  7. 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.

  8. Ulva and Enteromorpha (Ulvaceae, Chlorophyta) from two sides of the Yellow Sea: analysis of nuclear rDNA ITS and plastid rbcL sequence data

    Science.gov (United States)

    Wang, Jinfeng; Li, Nan; Jiang, Peng; Boo, Sung Min; Lee, Wook Jae; Cui, Yulin; Lin, Hanzhi; Zhao, Jin; Liu, Zhengyi; Qin, Song

    2010-07-01

    Ulvacean green seaweeds are common worldwide; they formed massive green tides in the Yellow Sea in recent years, which caused marine ecological problems as well as a social issue. We investigated two major genera of the Ulvaceae, Ulva and Enteromorpha, and collected the plastid rbcL and nuclear ITS sequences of specimens of the genera in two sides of the Yellow Sea and analyzed them. Phylogenetic trees of rbcL data show the occurrence of five species of Enteromorpha ( E. compressa, E. flexuosa, E. intestinalis, E. linza and E. prolifera) and three species of Ulva ( U. pertusa, U. rigida and U. ohnoi). However, we found U. ohnoi, which is known as a subtropical to tropical species, at two sites on Jeju Island, Korea. Four ribotypes in partial sequences of 5.8S rDNA and ITS2 from E. compressa were also found. Ribotype network analysis revealed that the common ribotype, occurring in China, Korea and Europe, is connected with ribotypes from Europe and China/Japan. Although samples of the same species were collected from both sides of the Yellow Sea, intraspecific genetic polymorphism of each species was low among samples collected worldwide.

  9. 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. Copyright © 2013 Elsevier B.V. All

  10. INFLUENCIA DE LAS CONDICIONES DE INCUBACIÓN SOBRE LA ACTIVACIÓN DE ZOOSPORAS DE Spongospora subterranea, EN BUSCA DE UN INÓCULO PARA EL ESTUDIO DE LA SARNA POLVOSA INFLUENCE OF INCUBATION CONDITIONS ON THE ACTIVATION OF ZOOSPORES OF Spongospora subterranea, SEARCHING FOR AN INOCULUM TO THE STUDY OF THE POWDERY SCAB

    Directory of Open Access Journals (Sweden)

    Edgar Beltrán Sánchez

    2009-12-01

    Full Text Available La sarna polvosa es una enfermedad que decrece la producción de papa. Es causada por el parásito obligado Spongospora subterranea f. sp. subterranea, el cual produce grupos de zoosporas enquistadas llamados quistosoros. Cuando las zoosporas están activas pueden infectar raíces y tubérculos iniciando un nuevo ciclo reproductivo. Para estudiar la influencia de las condiciones de incubación sobre la activación de las zoosporas, suspensiones acuosas de quistosoros fueron incubadas bajo diferentes condiciones. Los quistosoros y las zoosporas activas fueron diariamente contados utilizando microscopio óptico. El mayor número de zoosporas activas se encontró al cuarto día de incubación, mientras que el menor número de quistosoros se registró al quinto día de incubación. Esto sugiere que las zoosporas permanecen activas por un corto periodo. El número de zoosporas activas por quistosoro fue significativamente (PThe powdery scab is a disease that decreases potato production. It is caused by Spongospora subterranea f. sp. subterranea. This obligate parasite produces cystosori, which are groups of encysted zoospores. When these zoospores are active, they can infect roots and tubers initiating a new replication cycle. To investigate the influence of the incubation conditions on the zoospore activation, suspensions of cystosori in water were incubated under different conditions. The cystosori and the active zoospores were daily counted under microscope. The higher number of active zoospores was found after four days of incubation, meanwhile the lower number of cystosori was found after five days of incubation. This suggests that zoospores are active for a short period. The number of active zoospores per cystosorus was significantly (P<0.05 higher in tap water than in distillated water, and in presence of light than in dark. More zoospores per cystosorus were activated at 19 °C than at 5 °C, but potato roots did not have a significant (P<0

  11. 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.

  12. 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.

  13. Climate Adaptation and Harmful Algal Blooms

    Science.gov (United States)

    EPA supports local, state and tribal efforts to maintain water quality. A key element of its efforts is to reduce excess nutrient pollution and the resulting adverse impacts, including harmful algal blooms.

  14. Detecting the Killer Toxin (Harmful Algal Blooms)

    International Nuclear Information System (INIS)

    Quevenco, Rodolfo

    2011-01-01

    IAEA is stepping up efforts to help countries understand the phenomenon and use more reliable methods for early detection and monitoring so as to limit harmful algal blooms (HABs) adverse effects on coastal communities everywhere.

  15. Gasification of Phycoremediation Algal Biomass

    Directory of Open Access Journals (Sweden)

    Mahmoud A. Sharara

    2015-03-01

    Full Text Available Microalgae have been utilized in wastewater treatment strategies in various contexts. Uncontrolled algal species are a cheap and effective remediation strategy. This study investigates the thermochemical potential of wastewater treatment algae (phycoremediation as a means to produce renewable fuel streams and bio-products. Three gasification temperature levels were investigated in an auger gasification platform: 760, 860, and 960 °C. Temperature increases resulted in corresponding increases in CO and H2 concentrations in the producer gas from 12.8% and 4.7% at 760 °C to 16.9% and 11.4% at 960 °C, respectively. Condensable yields ranged between 15.0% and 16.6%, whereas char yields fell between 46.0% and 51.0%. The high ash content (40% on a dry basis was the main cause of the elevated char yields. On the other hand, the relatively high yields of condensables and a high carbon concentration in the char were attributed to the low conversion efficiency in this gasification platform. Combustion kinetics of the raw algae, in a thermogravimetric analyzer, showed three consecutive stages of weight loss: drying, devolatilization, and char oxidation. Increasing the algae gasification temperature led to increases in the temperature of peak char oxidation. Future studies will further investigate improvements to the performance of auger gasification.

  16. Effect of Arabinogalactan Proteins from the Root Caps of Pea and Brassica napus on Aphanomyces euteiches Zoospore Chemotaxis and Germination12[C][W

    Science.gov (United States)

    Cannesan, Marc Antoine; Durand, Caroline; Burel, Carole; Gangneux, Christophe; Lerouge, Patrice; Ishii, Tadashi; Laval, Karine; Follet-Gueye, Marie-Laure; Driouich, Azeddine; Vicré-Gibouin, Maïté

    2012-01-01

    Root tips of many plant species release a number of border, or border-like, cells that are thought to play a major role in the protection of root meristem. However, little is currently known on the structure and function of the cell wall components of such root cells. Here, we investigate the sugar composition of the cell wall of the root cap in two species: pea (Pisum sativum), which makes border cells, and Brassica napus, which makes border-like cells. We find that the cell walls are highly enriched in arabinose and galactose, two major residues of arabinogalactan proteins. We confirm the presence of arabinogalactan protein epitopes on root cap cell walls using immunofluorescence microscopy. We then focused on these proteoglycans by analyzing their carbohydrate moieties, linkages, and electrophoretic characteristics. The data reveal (1) significant structural differences between B. napus and pea root cap arabinogalactan proteins and (2) a cross-link between these proteoglycans and pectic polysaccharides. Finally, we assessed the impact of root cap arabinogalactan proteins on the behavior of zoospores of Aphanomyces euteiches, an oomycetous pathogen of pea roots. We find that although the arabinogalactan proteins of both species induce encystment and prevent germination, the effects of both species are similar. However, the arabinogalactan protein fraction from pea attracts zoospores far more effectively than that from B. napus. This suggests that root arabinogalactan proteins are involved in the control of early infection of roots and highlights a novel role for these proteoglycans in root-microbe interactions. PMID:22645070

  17. 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.

  18. 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.

  19. 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.

  20. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. 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.

  2. Sustainability of algal biofuel production using integrated renewable energy park (IREP) and algal biorefinery approach

    International Nuclear Information System (INIS)

    Subhadra, Bobban G.

    2010-01-01

    Algal biomass can provide viable third generation feedstock for liquid transportation fuel. However, for a mature commercial industry to develop, sustainability as well as technological and economic issues pertinent to algal biofuel sector must be addressed first. This viewpoint focuses on three integrated approaches laid out to meet these challenges. Firstly, an integrated algal biorefinery for sequential biomass processing for multiple high-value products is delineated to bring in the financial sustainability to the algal biofuel production units. Secondly, an integrated renewable energy park (IREP) approach is proposed for amalgamating various renewable energy industries established in different locations. This would aid in synergistic and efficient electricity and liquid biofuel production with zero net carbon emissions while obviating numerous sustainability issues such as productive usage of agricultural land, water, and fossil fuel usage. A 'renewable energy corridor' rich in multiple energy sources needed for algal biofuel production for deploying IREPs in the United States is also illustrated. Finally, the integration of various industries with algal biofuel sector can bring a multitude of sustainable deliverables to society, such as renewable supply of cheap protein supplements, health products and aquafeed ingredients. The benefits, challenges, and policy needs of the IREP approach are also discussed.

  3. Algal MIPs, high diversity and conserved motifs.

    Science.gov (United States)

    Anderberg, Hanna I; Danielson, Jonas Å H; Johanson, Urban

    2011-04-21

    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. 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. 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.

  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. Algal Toxins Alter Copepod Feeding Behavior

    Science.gov (United States)

    Hong, Jiarong; Talapatra, Siddharth; Katz, Joseph; Tester, Patricia A.; Waggett, Rebecca J.; Place, Allen R.

    2012-01-01

    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. PMID:22629336

  6. 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.

  7. Observations on algal populations in an experimental maturation pond system

    CSIR Research Space (South Africa)

    Shillinglaw, SN

    1977-01-01

    Full Text Available ?) of influent (HTE) and secondary pond. The arrows indicate the beginning of the noled algal concentration declines. 190 Water SA Vol. 3 No. 4 October 1977 intermittent presence of some factor which suppresses algal growth and/or removes algal cells from... the system at a very rapid rate. Another possibility is that an algal growth suppres sor is almost continuously present and only when the suppres sing factor is intermittently ahsent, do the algal concentrations exhihit a peak. Based on the results...

  8. Coralline-Like N-Doped Hierarchically Porous Carbon Derived from Enteromorpha as a Host Matrix for Lithium-Sulfur Battery.

    Science.gov (United States)

    Ji, Shengnan; Imtiaz, Sumair; Sun, Dan; Xin, Ying; Li, Qian; Huang, Taizhong; Zhang, Zhaoliang; Huang, Yunhui

    2017-12-22

    Coralline-like N-doped hierarchically porous carbon (CNHPC) was prepared through a hydrothermal carbonization process using a sea pollutant enteromorpha as the starting material. The addition of a small amount of glucose during carbonization improved the yield of carbon, and the inherent N contents, especially for pyrrolic N and pyridinic N atoms. After loading 40 wt. % sulfur, the CNHPC/S composite, as a cathode in a Li-S battery, exhibited an initial discharge capacity of 1617 mAh g -1 (96.5 % of theoretical capacity) at 0.1 C and a capacity loss of 0.05 % per charge-discharge cycle after 500 cycles at 0.5 C with a stable Coulombic efficiency of 100 % in carbonate based electrolyte. Such a great performance can be attributed to the coralline-like hierarchically porous infrastructure and inherently abundant N doping. Given the conversion of waste pollutants into valuable energy-storage materials and the easy process, this work features a promising approach to prepare C/S cathodes for Li-S batteries. The special structural and textural characteristics of CNHPC might be attractive to other practical applications such as supercapacitors and catalysis. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. A comparative study on the quality of bio-oil derived from green macroalga Enteromorpha clathrata over metal modified ZSM-5 catalysts.

    Science.gov (United States)

    Wang, Shuang; Cao, Bin; Liu, Xinlin; Xu, Lujiang; Hu, Yamin; Afonaa-Mensah, Stephen; Abomohra, Abd El-Fatah; He, Zhixia; Wang, Qian; Xu, Shannan

    2018-05-01

    The green macroalga Enteromorpha clathrata was pyrolyzed with or without catalysts at the temperature of 550 °C for producing high-quality bio-oil. The ZSM-5 and 1,2,3 mmol Mg-Ce/ZSM-5 catalysts were introduced to investigate the yields and components distribution of bio-oil. Increase of bio-oil production was obtained with the use of ZSM-5 and 1,2,3 mmol Mg-Ce/ZSM-5 catalysts. The 1 mmol Mg-Ce/ZSM-5 catalyst exhibited more promising property for promoting the relative content of C 5 -C 7 compounds, and decreasing the relative content of acids in bio-oil. The results suggested that E. clathrata had potential as pyrolysis feedstocks for producing the high-quality bio-oil with large amounts of C 5 -C 7 compounds and low relative content of acids when the 1 mmol Mg-Ce/ZSM-5 catalyst was used. Furthermore, the physicochemical properties of ZSM-5 and 1 mmol Mg-Ce/ZSM-5 catalysts were investigated by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and temperature-programmed desorption of ammonia. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. 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.

  11. Microbial bioenergetics of coral-algal interactions

    Directory of Open Access Journals (Sweden)

    Ty N.F. Roach

    2017-06-01

    Full Text Available Human impacts are causing ecosystem phase shifts from coral- to algal-dominated reef systems on a global scale. As these ecosystems undergo transition, there is an increased incidence of coral-macroalgal interactions. Mounting evidence indicates that the outcome of these interaction events is, in part, governed by microbially mediated dynamics. The allocation of available energy through different trophic levels, including the microbial food web, determines the outcome of these interactions and ultimately shapes the benthic community structure. However, little is known about the underlying thermodynamic mechanisms involved in these trophic energy transfers. This study utilizes a novel combination of methods including calorimetry, flow cytometry, and optical oxygen measurements, to provide a bioenergetic analysis of coral-macroalgal interactions in a controlled aquarium setting. We demonstrate that the energetic demands of microbial communities at the coral-algal interaction interface are higher than in the communities associated with either of the macroorganisms alone. This was evident through higher microbial power output (energy use per unit time and lower oxygen concentrations at interaction zones compared to areas distal from the interface. Increases in microbial power output and lower oxygen concentrations were significantly correlated with the ratio of heterotrophic to autotrophic microbes but not the total microbial abundance. These results suggest that coral-algal interfaces harbor higher proportions of heterotrophic microbes that are optimizing maximal power output, as opposed to yield. This yield to power shift offers a possible thermodynamic mechanism underlying the transition from coral- to algal-dominated reef ecosystems currently being observed worldwide. As changes in the power output of an ecosystem are a significant indicator of the current state of the system, this analysis provides a novel and insightful means to quantify

  12. 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.

  13. 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

  14. A review of algal research in space

    Science.gov (United States)

    Niederwieser, Tobias; Kociolek, Patrick; Klaus, David

    2018-05-01

    With the continued expansion of human presence into space, typical mission durations will routinely exceed six months and extend to distances beyond the Moon. As such, sending periodic resupply vehicles, as currently provided to the International Space Station, will likely no longer be feasible. Instead, self-sustaining life support systems that recycle human waste products will become increasingly necessary, especially for planetary bases. The idea of bioregenerative life support systems using algal photobioreactors has been discussed since the beginning of the space age. In order to evaluate how such a system could be implemented, a variety of space flight studies aimed at characterizing the potential for using algae in air revitalization, water recycling, food production, and radiation shielding applications have been conducted over the years. Also, given the recent, growing interest in algal research for regenerative fuel production, food supplements, and cosmetics, many algal strains are already well documented from related terrestrial experiments. This paper reviews past algal experiments flown in space from 1960 until today. Experimental methods and results from 51 investigations utilizing either green algae (Chlorophyta), cyanobacteria (Cyanophyta), or Euglenophyta are analyzed and categorized by a variety of parameters, including size, species and duration. The collected data are summarized in a matrix that allows easy comparison between the experiments and provides important information for future life support system requirement definition and design. Similarities between experiment results are emphasized. Common problems and shortcomings are summarized and analyzed in terms of potential solutions. Finally, key research gaps, which must be closed before developing a functional life support system, are identified.

  15. Thermodynamic analysis of algal biocrude production

    International Nuclear Information System (INIS)

    Beal, C.M.; Hebner, R.E.; Webber, M.E.

    2012-01-01

    Although algal biofuels possess great potential, profitable production is quite challenging. Much of this challenge is rooted in the thermodynamic constraints associated with producing fuels with high energy, low entropy, and high exergy from dispersed materials. In this study, a preliminary thermodynamic analysis is presented that calculates the energy, entropy, and exergy of the intermediate products for algal biocrude production. These values are also used in an initial attempt to characterize the thermodynamic efficiency of that system. The production pathway is simplified by assuming ideal solutions throughout. Results for the energy and exergy efficiencies, and the first-order energy and exergy return on investment, of the system are given. The summary finding is that the first-order energy return on investment in the best case considered could be as high as 520, as compared to 1.7 × 10 −3 in the experimental unit under development. While this analysis shows that significant improvement may be possible, the ultimate thermodynamic efficiency of algal biofuels likely lies closer to the moderate case examined here, which yielded a first-order energy return on investment of 10. For perspective, the first-order energy return on investment for oil and gas production has been estimated in the literature to be ∼35. -- Highlights: ► A first-principles thermodynamic analysis was conducted for algal biocrude production. ► The energy, entropy, and exergy was determined for each intermediate product by assuming the products were ideal solutions. ► The thermodynamic properties were used to calculate the energy and exergy return on investments for three cases. ► It was determined that the energy and exergy return on investments could be as high as ∼500. ► More realistic assumptions for efficient systems yielded return on investments on the order of 10.

  16. Control of algal production in a high rate algal pond: investigation through batch and continuous experiments.

    Science.gov (United States)

    Derabe Maobe, H; Onodera, M; Takahashi, M; Satoh, H; Fukazawa, T

    2014-01-01

    For decades, arid and semi-arid regions in Africa have faced issues related to water availability for drinking, irrigation and livestock purposes. To tackle these issues, a laboratory scale greywater treatment system based on high rate algal pond (HRAP) technology was investigated in order to guide the operation of the pilot plant implemented in the 2iE campus in Ouagadougou (Burkina Faso). Because of the high suspended solids concentration generally found in effluents of this system, the aim of this study is to improve the performance of HRAPs in term of algal productivity and removal. To determine the selection mechanism of self-flocculated algae, three sets of sequencing batch reactors (SBRs) and three sets of continuous flow reactors (CFRs) were operated. Despite operation with the same solids retention time and the similarity of the algal growth rate found in these reactors, the algal productivity was higher in the SBRs owing to the short hydraulic retention time of 10 days in these reactors. By using a volume of CFR with twice the volume of our experimental CFRs, the algal concentration can be controlled during operation under similar physical conditions in both reactors.

  17. Algal-bacterial interactions in metal contaminated floodplain sediments

    International Nuclear Information System (INIS)

    Boivin, M.E.Y.; Greve, G.D.; Garcia-Meza, J.V.; Massieux, B.; Sprenger, W.; Kraak, M.H.S.; Breure, A.M.; Rutgers, M.; Admiraal, W.

    2007-01-01

    The aim of the present study was to investigate algal-bacterial interactions in a gradient of metal contaminated natural sediments. By means of multivariate techniques, we related the genetic structure (denaturing gradient gel electrophoresis, DGGE) and the physiological structure (community-level physiological profiling, CLPP) of the bacterial communities to the species composition of the algal communities and to the abiotic environmental variables, including metal contamination. The results revealed that genetic and physiological structure of the bacterial communities correlated with the species composition of the algal community, but hardly to the level of metal pollution. This must be interpreted as an indication for a strong and species-specific linkage of algal and bacterial species in floodplain sediments. Metals were, however, not proven to affect either the algal or the bacterial communities of the Dutch river floodplains. - Algal and bacterial communities in floodplain sediments are interlinked, but are not affected by metal pollution

  18. Stimulation of bacterial DNA synthesis by algal exudates in attached algal-bacterial consortia

    International Nuclear Information System (INIS)

    Murray, R.E.; Cooksey, K.E.; Priscu, J.C.

    1986-01-01

    Algal-bacterial consortia attached to polystyrene surfaces were prepared in the laboratory by using the marine diatom Amphora coffeaeformis and the marine bacterium Vibrio proteolytica (the approved name of this bacterium is Vibrio proteolyticus. The organisms were attached to the surfaces at cell densities of approximately 5 x 10 4 cells cm -2 (diatoms) and 5 x 10 6 cells cm -2 (bacteria). The algal-bacterial consortia consistently exhibited higher rates of [ 3 H]thymidine incorporation than did biofilms composed solely of bacteria. The rates of [ 3 H]thymidine incorporation by the algal-bacterial consortia were fourfold greater than the rates of incorporation by monobacterial biofilms 16 h after biofilm formation and were 16-fold greater 70 h after biofilm formation. Extracellular material released from the attached Amphora cells supported rates of bacterial activity (0.8 x 10 -21 mol to 17.9 x 10 -21 mol of [ 3 H]thymidine incorporated cell -1 h -1 ) and growth (doubling time, 29.5 to 1.4 days) comparable to values reported for a wide variety of marine and freshwater ecosystems. In the presence of sessile diatom populations, DNA synthesis by attached V. proteolytica cells was light dependent and increased with increasing algal abundance. The metabolic activity of diatoms thus appears to be the rate-limiting process in biofilm development on illuminated surfaces under conditions of low bulk-water dissolved organic carbon

  19. 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.

  20. Mechanical algal disruption for efficient biodiesel extraction

    Science.gov (United States)

    Krehbiel, Joel David

    Biodiesel from algae provides several benefits over current biodiesel feedstocks, but the energy requirements of processing algae into a useable fuel are currently so high as to be prohibitive. One route to improving this is via disruption of the cells prior to lipid extraction, which can significantly increase energy recovery. Unfortunately, several obvious disruption techniques require more energy than can be gained. This dissertation examines the use of microbubbles to improve mechanical disruption of algal cells using experimental, theoretical, and computational methods. New laboratory experiments show that effective ultrasonic disruption of algae is achieved by adding microbubbles to an algal solution. The configuration studied flows the solution through a tube and insonifies a small section with a high-pressure ultrasound wave. Previous biomedical research has shown effective cell membrane damage on animal cells with similar methods, but the present research is the first to extend such study to algal cells. Results indicate that disruption increases with peak negative pressure between 1.90 and 3.07 MPa and with microbubble concentration up to 12.5 x 107 bubbles/ml. Energy estimates of this process suggest that it requires only one-fourth the currently most-efficient laboratory-scale disruption process. Estimates of the radius near each bubble that causes disruption (i.e. the disruption radius) suggest that it increases with peak negative pressure and is near 9--20 microm for all cases tested. It is anticipated that these procedures can be designed for better efficiency and efficacy, which will be facilitated by identifying the root mechanisms of the bubble-induced disruption. We therefore examine whether bubble expansion alone creates sufficient cell deformation for cell rupture. The spherically-symmetric Marmottant model for bubble dynamics allows estimation of the flow regime under experimental conditions. Bubble expansion is modeled as a point source of

  1. Algal-Based Renewable Energy for Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Fritsen, Christian [Desert Research Institute, Las Vegas, NV (United States)

    2017-03-31

    To help in the overall evaluation of the potential for growing algal biomass in high productivity systems, we conducted a study that evaluated water from geothermal sources and cultivated mixed consortia from hot springs in Nevada, we evaluated their growth at moderately high varying temperatures and then evaluated potential manipulations that could possibly increase their biomass and oleaginous production. Studies were conducted at scales ranging from the laboratory benchtop to raceways in field settings. Mixed consortia were readily grown at all scales and growth could be maintained in Nevada year round. Moderate productivities were attained even during the shoulder seasons- where temperature control was maintained by hot water and seasonally cold temperatures when there was still plentiful solar radiation. The results enhance the prospects for economic feasibility of developing algal based industries in areas with geothermal energy or even other large alternative sources of heat that are not being used for other purposes. The public may benefit from such development as a means for economic development as well as development of industries for alternative energy and products that do not rely on fossil fuels.

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

    KAUST Repository

    Dramas, Laure

    2014-01-01

    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

  3. Dynamic metabolic exchange governs a marine algal-bacterial interaction.

    Science.gov (United States)

    Segev, Einat; Wyche, Thomas P; Kim, Ki Hyun; Petersen, Jörn; Ellebrandt, Claire; Vlamakis, Hera; Barteneva, Natasha; Paulson, Joseph N; Chai, Liraz; Clardy, Jon; Kolter, Roberto

    2016-11-18

    Emiliania huxleyi is a model coccolithophore micro-alga that generates vast blooms in the ocean. Bacteria are not considered among the major factors influencing coccolithophore physiology. Here we show through a laboratory model system that the bacterium Phaeobacter inhibens , a well-studied member of the Roseobacter group, intimately interacts with E. huxleyi. While attached to the algal cell, bacteria initially promote algal growth but ultimately kill their algal host. Both algal growth enhancement and algal death are driven by the bacterially-produced phytohormone indole-3-acetic acid. Bacterial production of indole-3-acetic acid and attachment to algae are significantly increased by tryptophan, which is exuded from the algal cell. Algal death triggered by bacteria involves activation of pathways unique to oxidative stress response and programmed cell death. Our observations suggest that bacteria greatly influence the physiology and metabolism of E. huxleyi. Coccolithophore-bacteria interactions should be further studied in the environment to determine whether they impact micro-algal population dynamics on a global scale.

  4. 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.

  5. Changes in algal composition and environmental variables in the ...

    African Journals Online (AJOL)

    Monthly sampling in 2003 and 2006 indicated that dissolved inorganic nitrogen concentrations decreased, while dissolved inorganic phosphorus concentration increased 12-fold, resulting in increases in algal concentration and a shift from green algal dominance in 2003 to cyanobacterial dominance in 2006. Multivariate ...

  6. COMPARISON OF LARGE RIVER SAMPLING METHODS ON ALGAL METRICS

    Science.gov (United States)

    We compared the results of four methods used to assess the algal communities at 60 sites distributed among four rivers. Based on Principle Component Analysis of physical habitat data collected concomitantly with the algal data, sites were separated into those with a mean thalweg...

  7. Algal diversity of Adada River, Nigeria. I. Chlorophyta (green algae ...

    African Journals Online (AJOL)

    Commercial water tankers collect water and sell to indigenes and towns around the river, hence the need to investigate the algal biodiversity in other to access its suitability for human consumption using known algal indicators of water quality and add to the pool of data useful for long term trends in floral composition in ...

  8. Increasing the extraction efficiency of algal lipid for biodiesel ...

    African Journals Online (AJOL)

    Various studies have been conducted recently using microalgal system for the production of algal lipid for biodiesel production. This study aimed at increasing the extraction efficiency of algal lipid from Chlorella sp. by the application of Chlorella viruses. The calorific value of lipid from Chlorella sp. has been reported to be ...

  9. Deep-Learning-Based Approach for Prediction of Algal Blooms

    Directory of Open Access Journals (Sweden)

    Feng Zhang

    2016-10-01

    Full Text Available Algal blooms have recently become a critical global environmental concern which might put economic development and sustainability at risk. However, the accurate prediction of algal blooms remains a challenging scientific problem. In this study, a novel prediction approach for algal blooms based on deep learning is presented—a powerful tool to represent and predict highly dynamic and complex phenomena. The proposed approach constructs a five-layered model to extract detailed relationships between the density of phytoplankton cells and various environmental parameters. The algal blooms can be predicted by the phytoplankton density obtained from the output layer. A case study is conducted in coastal waters of East China using both our model and a traditional back-propagation neural network for comparison. The results show that the deep-learning-based model yields better generalization and greater accuracy in predicting algal blooms than a traditional shallow neural network does.

  10. Detection of surface algal blooms using the newly developed algorithm surface algal bloom index (SABI)

    Science.gov (United States)

    Alawadi, Fahad

    2010-10-01

    Quantifying ocean colour properties has evolved over the past two decades from being able to merely detect their biological activity to the ability to estimate chlorophyll concentration using optical satellite sensors like MODIS and MERIS. The production of chlorophyll spatial distribution maps is a good indicator of plankton biomass (primary production) and is useful for the tracing of oceanographic currents, jets and blooms, including harmful algal blooms (HABs). Depending on the type of HABs involved and the environmental conditions, if their concentration rises above a critical threshold, it can impact the flora and fauna of the aquatic habitat through the introduction of the so called "red tide" phenomenon. The estimation of chlorophyll concentration is derived from quantifying the spectral relationship between the blue and the green bands reflected from the water column. This spectral relationship is employed in the standard ocean colour chlorophyll-a (Chlor-a) product, but is incapable of detecting certain macro-algal species that float near to or at the water surface in the form of dense filaments or mats. The ability to accurately identify algal formations that sometimes appear as oil spill look-alikes in satellite imagery, contributes towards the reduction of false-positive incidents arising from oil spill monitoring operations. Such algal formations that occur in relatively high concentrations may experience, as in land vegetation, what is known as the "red-edge" effect. This phenomena occurs at the highest reflectance slope between the maximum absorption in the red due to the surrounding ocean water and the maximum reflectance in the infra-red due to the photosynthetic pigments present in the surface algae. A new algorithm termed the surface algal bloom index (SABI), has been proposed to delineate the spatial distributions of floating micro-algal species like for example cyanobacteria or exposed inter-tidal vegetation like seagrass. This algorithm was

  11. FACTORES QUE INCIDEN EN LA LIBERACIÓN DE ZOOSPORAS DE Spongospora subterranea (Wallroth Lagerheim f. sp. subterranea Tomlinson FACTORS AFECTING THE ZOOSPORE RELEASE OF Spongospora subterranean (Wallroth Lagerheim f. sp. subterranea Tomlinson

    Directory of Open Access Journals (Sweden)

    Daniel Esteban Alzate Velez

    2008-12-01

    Full Text Available Spongospora subterranea (Wallroth Lagerheim f. sp. subterranea Tomlinson es el agente causal de la sarna polvosa de la papa. Este patógeno es un protozoario, su infección ocurre por medio de zoosporas las cuales se liberan a partir de quistosoros y son el principal modo de dispersión de la enfermedad. Estos pueden encontrarse en tubérculos, raíces y el suelo, donde permanecen como estructuras de resistencia por varios años, hasta cuando las condiciones ambientales favorecen la liberación de zoosporas, para dar inicio a nuevas infecciones. En este trabajo, se evaluó el efecto de los exudados de raíz de papa, temperatura y fuente de inóculo con quistosoros aislados de suelo, raíz y tubérculo con el objetivo de verificar las condiciones en las cuales ocurre la liberación de zoosporas. Para tal fin se realizaron dos experimentos, en el primero se evaluó el efecto del agua y extracto de raíces y en el segundo el extracto de raíces y las diferentes fuentes de inóculo. Las evaluaciones se hicieron por conteo de zoosporas móviles durante 120 horas cada 24 horas. Se observó que el exudado de raíz tiene una alta influencia en la liberación de zoosporas, la cual ocurre entre los 15 y 23 °C a partir de las 48 y hasta las 96 horas, no se detectaron diferencias entre las fuentes de inóculo, lo que indica que independiente de su origen, si existen las condiciones ambientales adecuadas los quistosoros, tienen la capacidad de liberar un número suficiente de zoosporas que potencialmente pueden iniciar el proceso de infección en el hospedero.Spongospora subterranea (Wallroth Lagerheim f. sp. subterranea Tomlinson is the causal agent of potato powdery scab. This pathogen is worldwide distributed on the potato fields, infections occurs by zoospores which are inside resting spores called sporeballs or cystosori which are the principal way of disease spread. Sporeballs can be found on tubers, roots and soil as resistance structure, that can

  12. Effect of partially purified components of zoospores and mycelia of phytophthora infestans on uptake of 3H-leucine by potato tuber disks

    International Nuclear Information System (INIS)

    Nishimura, Norio; Tomiyama, Kohei; Doke, Noriyuki

    1980-01-01

    The zoosporial component of Phytophthora infestans, which was previously reported to cause reduction of 3 H-leucine uptake by potato tuber disks, was partially purified. Precipitate (A-fraction) was obtained by homogenizing zoospores with acetate buffer at pH 4.5 and centrifuging at 20,000 x g, and the A-fraction was suspended in borate buffer at pH 8.8, boiled for 1 hr and then centrifuged at 20,000 x g, giving the precipitate (B-fraction) and supernatant (C-fraction). Ten ml of 10 mM tris-HCl buffer containing 1 mM CaCl 2 at pH 7.4 was used to suspend A and B-fraction. The buffer was used as a control. A, B and C fractions obtained from 5 - 6 x 10 6 zoosprores reducted uptake of 3 H-leucine by the tuber disks of potato cv. Rishiri, but the inhibition rates caused by these fractions differed markedly. However, very high correlation was found between inhibition rates of 3 H-leucine uptake and sugar contents of these fractions. There was no difference in the inhibition rates between the zoosporial components of incompatible and compatible races, when the activities were expressed in terms of the sugar contents. The mycelial components of P. infestans extracted by the modified method of Lisker and Kuc which was used to extract phytoalexin elicitor from that of P. infestans, also had the same effect as the zoosporial components (A, B, and C-fraction) on 3 H-leucine uptake by the disks. C-fraction containing 15 μg of sugar per ml sufficed to inhibit 3 H-leucine uptake at the maximum rate, and the maximum rate of inhibition was attained within 2 hr after the zoosporial component (C-fraction containing 30 μg sugar/ml) was administered to the disks. (author)

  13. Detection of surface algal blooms using the newly developed algorithm surface algal bloom index SABI)

    OpenAIRE

    Alawadi, Fahad

    2010-01-01

    Quantifying ocean colour properties has evolved over the past two decades from being able to merely detect their biological activity to the ability to estimate chlorophyll concentration using optical satellite sensors like MODIS and MERIS. The production of chlorophyll spatial distribution maps is a good indicator of plankton biomass (primary production) and is useful for the tracing of oceanographic currents, jets and blooms, including harmful algal blooms (HABs). Depending on the type of HA...

  14. Marine Bacteria from Danish Coastal Waters Show Antifouling Activity against the Marine Fouling Bacterium Pseudoalteromonas sp. Strain S91 and Zoospores of the Green Alga Ulva australis Independent of Bacteriocidal Activity

    DEFF Research Database (Denmark)

    Bernbom, Nete; Ng, Yoke Yin; Kjelleberg, Staffan

    2011-01-01

    , representing the major taxonomic groups, different seasons, and isolation strategies, were tested for antiadhesive effect against the marine biofilm-forming bacterium Pseudoalteromonas sp. strain S91 and zoospores of the green alga Ulva australis. The antiadhesive effects were assessed by quantifying...... the number of strain S91 or Ulva spores attaching to a preformed biofilm of each of the 22 strains. The strongest antifouling activity was found in Pseudoalteromonas strains. Biofilms of Pseudoalteromonas piscicida, Pseudoalteromonas tunicata, and Pseudoalteromonas ulvae prevented Pseudoalteromonas S91 from...

  15. 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.

  16. 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

  17. 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.

  18. 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

  19. Dendritic cells pulsed with Pythium insidiosum (1,3)(1,6)-β-glucan, Heat-inactivated zoospores and immunotherapy prime naïve T cells to Th1 differentiation in vitro.

    Science.gov (United States)

    Ledur, Pauline C; Tondolo, Juliana S M; Jesus, Francielli P K; Verdi, Camila M; Loreto, Érico S; Alves, Sydney H; Santurio, Janio M

    2018-03-01

    Pythiosis is a life-threatening disease caused by the fungus-like microorganism Pythium insidiosum that can lead to death if not treated. Since P. insidiosum has particular cell wall characteristics, pythiosis is difficult to treat, as it does not respond well to traditional antifungal drugs. In our study, we investigated a new immunotherapeutic approach with potential use in treatment and in the acquisition of immunity against pythiosis. Dendritic cells from both human and mouse, pulsed with P. insidiosum heat-inactivated zoospore, (1,3)(1,6)-β-glucan and the immunotherapeutic PitiumVac ® efficiently induced naïve T cell differentiation in a Th1 phenotype by the activation of specific Th1 cytokine production in vitro. Heat-inactivated zoospores showed the greatest Th1 response among the tested groups, with a significant increase in IL-6 and IFN-γ production in human cells. In mice cells, we also observed a Th17 pathway induction, with an increase on the IL-17A levels in lymphocytes cultured with β-glucan pulsed DCs. These results suggest a potential use of DCs pulsed with P. insidiosum antigens as a new therapeutic strategy in the treatment and acquisition of immunity against pythiosis. Copyright © 2017 Elsevier GmbH. All rights reserved.

  20. 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. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. The Structure of Algal Population in the Presence of Toxicants

    Science.gov (United States)

    Ipatova, Valentina; Prokhotskaya, Valeria; Dmitrieva, Aida

    Algal bioassays are routinely employed as part of a battery of toxicity tests to assess the environmental impacts of contaminants on aquatic ecosystems. This estimation is an essential component of the ecological risk assessment.

  2. 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.

  3. Marine algal flora of submerged Angria Bank (Arabian Sea)

    Digital Repository Service at National Institute of Oceanography (India)

    Untawale, A.G.; Reddy, C.R.K.; Ambiye, V.

    Submerged Angria Bank was surveyed for the deep water marine algal flora. About 57 species were reported from this bank for the first time. Rhodophyta dominated (30 species) followed by Chlorophyta (18 species) and Phaeophyta (9 species). A few...

  4. In situ Transesterification of Microalgal Oil to Produce Algal Biodiesel

    Science.gov (United States)

    2012-06-01

    This research was to process whole microalgae cells for biodiesel production without first extracting lipids. The ultimate : goal is develop a novel process for algal biodiesel production directly from microalgae cells in a single step, i.e., in situ...

  5. Rotating Algal Biofilm Reactors: Mathematical Modeling and Lipid Production

    OpenAIRE

    Woolsey, Paul A.

    2011-01-01

    Harvesting of algal biomass presents a large barrier to the success of biofuels made from algae feedstock. Small cell sizes coupled with dilute concentrations of biomass in lagoon systems make separation an expensive and energy intense-process. The rotating algal biofilm reactor (RABR) has been developed at USU to provide a sustainable technology solution to this issue. Algae cells grown as a biofilm are concentrated in one location for ease of harvesting of high density biomass. A mathematic...

  6. 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.

  7. Ecological study of algal flora of Neelum river Azad Kashmir

    International Nuclear Information System (INIS)

    Leghari, M.K.; Leghari, M.Y.

    2000-01-01

    First time ecological study of Algal Flora of Neelum River Azad Kashmir was carried out during January 1998 to July 1998. A total of 78 species belonging to 48 genera of 4 Algal groups. Cyanophyceae (16 species 20.5 % belonging to 11 genera), Choloronophycease (23 species 29.5 % belonging to 18 genera), Bacillariophyceae (37 species 47 % belonging to 17 genera), Xanthophyceae (2 species 3 % belonging to 2 genera) and 39 physico - chemical parameters were recorded. (author)

  8. Algal Turf Scrubbers: Cleaning Water While Capturing Solar Energy

    International Nuclear Information System (INIS)

    Adey, W.

    2009-01-01

    Algal Turfs and Algal Turf Scrubbers (ATS) Algal Turfs are bio diverse communities of unicellular to filamentous algae of all major algal phyla. Algal Turf Scrubbers (ATS) are bioengineered ecosystems dominated by algal turfs. They clean water to very high quality, and remove CO 2 from the atmosphere by capturing solar energy at rates 10 times that of agriculture and 50 times that of forestry. ATS was invented at the Smithsonian Institution, by scientist, Walter Adey in the 1980s as a tool for controlling water quality in highly diverse model ecosystems. The technology received extensive R and D for aqua cultural, municipal, and industrial water cleaning by Dr. Adey, using venture capital, through the 1990s. Later, Hydro Mentia, Inc., of Ocala, Florida, engineered ATS to landscape scale of 20-50 Mgpd (it is important to note that this is a modular system, capable of expanding to any size.) A 2005 independent study of ATS, by the South Florida Water Management District and the IFAS Institute of the University of Florida, certified ATS as 5-100 times more cost efficient at removing nutrients from Everglades canal waters than the next competitor, the STA, a managed marsh system. ATS and STA were the final contestants in a 15-year study of nine technologies, and ATS was the only technology that created a use able byproduct.

  9. 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.

  10. 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.

  11. 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.

  12. Satellite monitoring of cyanobacterial harmful algal bloom ...

    Science.gov (United States)

    Cyanobacterial harmful algal blooms (cyanoHABs) cause extensive problems in lakes worldwide, including human and ecological health risks, anoxia and fish kills, and taste and odor problems. CyanoHABs are a particular concern because of their dense biomass and the risk of exposure to toxins in both recreational waters and drinking source waters. Successful cyanoHAB assessment by satellites may provide a first-line of defense indicator for human and ecological health protection. In this study, assessment methods were developed to determine the utility of satellite technology for detecting cyanoHAB occurrence frequency at locations of potential management interest. The European Space Agency's MEdium Resolution Imaging Spectrometer (MERIS) was evaluated to prepare for the equivalent Sentinel-3 Ocean and Land Colour Imager (OLCI) launched in 2016. Based on the 2012 National Lakes Assessment site evaluation guidelines and National Hydrography Dataset, there were 275,897 lakes and reservoirs greater than 1 hectare in the 48 U.S. states. Results from this evaluation show that 5.6 % of waterbodies were resolvable by satellites with 300 m single pixel resolution and 0.7 % of waterbodies were resolvable when a 3x3 pixel array was applied based on minimum Euclidian distance from shore. Satellite data was also spatially joined to US public water surface intake (PWSI) locations, where single pixel resolution resolved 57% of PWSI and a 3x3 pixel array resolved 33% of

  13. Linking algal growth inhibition to chemical activity

    DEFF Research Database (Denmark)

    Schmidt, Stine N.; Mayer, Philipp

    Unitless chemical activity, expressing the energetic level of a compound relative to its energetic level in pure liquid [0-1], has proven useful to quantify the effective exposure to hydrophobic organic compounds through both aerial and aqueous media. Several studies have linked toxicity to chemi......Unitless chemical activity, expressing the energetic level of a compound relative to its energetic level in pure liquid [0-1], has proven useful to quantify the effective exposure to hydrophobic organic compounds through both aerial and aqueous media. Several studies have linked toxicity...... 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......-polar liquids were applied to challenge the chemical activity range for baseline toxicity. For each compound, the effective activity (Ea50) was estimated as the ratio of the effective concentration (EC50) and water solubility. Of these ratios, 90% were within the expected chemical activity range of 0.01 to 0...

  14. Energetic potential of algal biomass from high-rate algal ponds for the production of solid biofuels.

    Science.gov (United States)

    Costa, Taynan de Oliveira; Calijuri, Maria Lúcia; Avelar, Nayara Vilela; Carneiro, Angélica de Cássia de Oliveira; de Assis, Letícia Rodrigues

    2017-08-01

    In this investigation, chemical characteristics, higher, lower and net heating value, bulk and energy density, and thermogravimetric analysis were applied to study the thermal characteristics of three algal biomasses. These biomasses, grown as by-products of wastewater treatment in high-rate algal ponds (HRAPs), were: (i) biomass produced in domestic effluent and collected directly from an HRAP (PO); (ii) biomass produced in domestic effluent in a mixed pond-panel system and collected from the panels (PA); and (iii) biomass originating from the treatment effluent from the meat processing industry and collected directly from an HRAP (IN). The biomass IN was the best alternative for thermal power generation. Subsequently, a mixture of the algal biomasses and Jatropha epicarp was used to produce briquettes containing 0%, 25%, 50%, 75%, and 100% of algal biomass, and their properties were evaluated. In general, the addition of algal biomass to briquettes decreased both the hygroscopicity and fixed carbon content and increased the bulk density, ash content, and energy density. A 50% proportion of biomass IN was found to be the best raw material for producing briquettes. Therefore, the production of briquettes consisting of algal biomass and Jatropha epicarp at a laboratory scale was shown to be technically feasible.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. Marine algal toxins: origins, health effects, and their increased occurrence

    International Nuclear Information System (INIS)

    Van Dolah, Frances M.

    2000-01-01

    Certain marine algae produce potent toxins that impact human health through the consumption of contaminated shellfish and finfish and through water or aerosol exposure. Over the past three decades, the frequency and global distribution of toxic algal incidents appear to have increased, and human intoxications from novel algal sources have occurred. This increase is of particular concern, since it parallels recent evidence of large-scale ecologic disturbances that coincide with trends in global warming. The extent to which human activities have contributed to their increase therefore comes into question. This review summarizes the origins and health effects of marine algal toxins, as well as changes in their current global distribution, and examines possible causes for the recent increase in their occurrence. (Author)

  20. Hydrogen from algal biomass: A review of production process

    Directory of Open Access Journals (Sweden)

    Archita Sharma

    2017-09-01

    Full Text Available Multifariousness of biofuel sources has marked an edge to an imperative energy issue. Production of hydrogen from microalgae has been gathering much contemplation right away. But, mercantile production of microalgae biofuels considering bio-hydrogen is still not practicable because of low biomass concentration and costly down streaming processes. This review has taken up the hydrogen production by microalgae. Biofuels are the up and coming alternative to exhaustible, environmentally and unsafe fossil fuels. Algal biomass has been considered as an enticing raw material for biofuel production, these days photobioreactors and open-air systems are being used for hydrogen production from algal biomass. The formers allow the careful cultivation control whereas the latter ones are cheaper and simpler. A contemporary, encouraging optimization access has been included called algal cell immobilization on various matrixes which has resulted in marked increase in the productivity per volume of a reactor and addition of the hydrogen-production phase.

  1. Hydrogen production from algal biomass - Advances, challenges and prospects.

    Science.gov (United States)

    Show, Kuan-Yeow; Yan, Yuegen; Ling, Ming; Ye, Guoxiang; Li, Ting; Lee, Duu-Jong

    2018-06-01

    Extensive effort is being made to explore renewable energy in replacing fossil fuels. Biohydrogen is a promising future fuel because of its clean and high energy content. A challenging issue in establishing hydrogen economy is sustainability. Biohydrogen has the potential for renewable biofuel, and could replace current hydrogen production through fossil fuel thermo-chemical processes. A promising source of biohydrogen is conversion from algal biomass, which is abundant, clean and renewable. Unlike other well-developed biofuels such as bioethanol and biodiesel, production of hydrogen from algal biomass is still in the early stage of development. There are a variety of technologies for algal hydrogen production, and some laboratory- and pilot-scale systems have demonstrated a good potential for full-scale implementation. This work presents an elucidation on development in biohydrogen encompassing biological pathways, bioreactor designs and operation and techno-economic evaluation. Challenges and prospects of biohydrogen production are also outlined. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Catalytic Processes for Utilizing Carbohydrates Derived from Algal Biomass

    Directory of Open Access Journals (Sweden)

    Sho Yamaguchi

    2017-05-01

    Full Text Available The high productivity of oil biosynthesized by microalgae has attracted increasing attention in recent years. Due to the application of such oils in jet fuels, the algal biosynthetic pathway toward oil components has been extensively researched. However, the utilization of the residue from algal cells after oil extraction has been overlooked. This residue is mainly composed of carbohydrates (starch, and so we herein describe the novel processes available for the production of useful chemicals from algal biomass-derived sugars. In particular, this review highlights our latest research in generating lactic acid and levulinic acid derivatives from polysaccharides and monosaccharides using homogeneous catalysts. Furthermore, based on previous reports, we discuss the potential of heterogeneous catalysts for application in such processes.

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

    DEFF Research Database (Denmark)

    Singh, Anoop; Olsen, Stig Irving

    2011-01-01

    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......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...

  4. 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.

  5. Early detection of protozoan grazers in algal biofuel cultures.

    Science.gov (United States)

    Day, John G; Thomas, Naomi J; Achilles-Day, Undine E M; Leakey, Raymond J G

    2012-06-01

    Future micro-algal biofuels will most likely be derived from open-pond production systems. These are by definition open to "invasion" by grazers, which could devastate micro-algal mass-cultures. There is an urgent requirement for methodologies capable of early detection and control of grazers in dense algal cultures. In this study a model system employing the marine alga Nannochloropsis oculata was challenged by grazers including ciliates, amoebae and a heterotrophic dinoflagellate. A FlowCAM flow-cytometer was used to detect all grazers investigated (size range 80 μm in length) in the presence of algae. Detection limits were 1.4 × 10(8) cells ml(-1) (>0.5 g l(-1) dry wt.). Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. 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.

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

    KAUST Repository

    Villacorte, Loreen O.; Tabatabai, S. Assiyeh Alizadeh; Dhakal, N.; Amy, Gary L.; Schippers, Jan Cornelis; Kennedy, Maria Dolores

    2014-01-01

    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.

  8. Marine Bacteria from Danish Coastal Waters Show Antifouling Activity against the Marine Fouling Bacterium Pseudoalteromonas sp. Strain S91 and Zoospores of the Green Alga Ulva australis Independent of Bacteriocidal Activity▿†

    Science.gov (United States)

    Bernbom, Nete; Ng, Yoke Yin; Kjelleberg, Staffan; Harder, Tilmann; Gram, Lone

    2011-01-01

    The aims of this study were to determine if marine bacteria from Danish coastal waters produce antifouling compounds and if antifouling bacteria could be ascribed to specific niches or seasons. We further assess if antibacterial effect is a good proxy for antifouling activity. We isolated 110 bacteria with anti-Vibrio activity from different sample types and locations during a 1-year sampling from Danish coastal waters. The strains were identified as Pseudoalteromonas, Phaeobacter, and Vibrionaceae based on phenotypic tests and partial 16S rRNA gene sequence similarity. The numbers of bioactive bacteria were significantly higher in warmer than in colder months. While some species were isolated at all sampling locations, others were niche specific. We repeatedly isolated Phaeobacter gallaeciensis at surfaces from one site and Pseudoalteromonas tunicata at two others. Twenty-two strains, representing the major taxonomic groups, different seasons, and isolation strategies, were tested for antiadhesive effect against the marine biofilm-forming bacterium Pseudoalteromonas sp. strain S91 and zoospores of the green alga Ulva australis. The antiadhesive effects were assessed by quantifying the number of strain S91 or Ulva spores attaching to a preformed biofilm of each of the 22 strains. The strongest antifouling activity was found in Pseudoalteromonas strains. Biofilms of Pseudoalteromonas piscicida, Pseudoalteromonas tunicata, and Pseudoalteromonas ulvae prevented Pseudoalteromonas S91 from attaching to steel surfaces. P. piscicida killed S91 bacteria in the suspension cultures, whereas P. tunicata and P. ulvae did not; however, they did prevent adhesion by nonbactericidal mechanism(s). Seven Pseudoalteromonas species, including P. piscicida and P. tunicata, reduced the number of settling Ulva zoospores to less than 10% of the number settling on control surfaces. The antifouling alpP gene was detected only in P. tunicata strains (with purple and yellow pigmentation), so

  9. Carbohydrate-degrading bacteria closely associated with Tetraselmis indica: Influence on algal growth

    Digital Repository Service at National Institute of Oceanography (India)

    Arora, M.; Anil, A.C.; Delany, J.; Rajarajan, N.; Emami, K.; Mesbahi, E.

    to promote growth of the algae. These experiments revealed that microbes associated with the alga differentially influence algal growth dynamics. Bacterial presence on the cast-off cell wall products of the alga suggested the likely utilisation of algal cell...

  10. Basic and Applied Algal Life Support System Research on Board the Deep Space Gateway

    Science.gov (United States)

    Niederwieser, T.; Zea, L.; Anthony, J.; Stodieck, L.

    2018-02-01

    We study the effect of long-term preservation methods on DNA damage of algal cultures for BLSS applications. In a secondary step, the Deep Space Gateway serves as a technology demonstration platform for algal photobioreactors in intermittently occupied habitats.

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

    Energy Technology Data Exchange (ETDEWEB)

    Laurens, Lieve M. L.

    2016-01-13

    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. Physical processes contributing to harmful algal blooms in Saldanha ...

    African Journals Online (AJOL)

    Since 1994, disruption of harvesting as a result of the presence of harmful algal species has been a regular late-summer phenomenon. Toxic blooms that are ultimately advected into the bay develop on the continental shelf to the north between 32°S and St Helena Bay, a region characterized by favourable conditions for ...

  13. Environmental variables, algal pigments and phytoplankton in the ...

    African Journals Online (AJOL)

    The phytoplankton diversity, environmental variables and algal pigments of the Atlantic Ocean off the coast of Badagry, Lagos were investigated for twelve months between May 2015 and April 2016. The water chemistry characteristics reflected sea water conditions. At the two stations, the range of values recorded for some ...

  14. Effects of fertilizers used in agricultural fields on algal blooms

    Science.gov (United States)

    Chakraborty, Subhendu; Tiwari, P. K.; Sasmal, S. K.; Misra, A. K.; Chattopadhyay, Joydev

    2017-06-01

    The increasing occurrence of algal blooms and their negative ecological impacts have led to intensified monitoring activities. This needs the proper identification of the most responsible factor/factors for the bloom formation. However, in natural systems, algal blooms result from a combination of factors and from observation it is difficult to identify the most important one. In the present paper, using a mathematical model we compare the effects of three human induced factors (fertilizer input in agricultural field, eutrophication due to other sources than fertilizers, and overfishing) on the bloom dynamics and DO level. By applying a sophisticated sensitivity analysis technique, we found that the increasing use of fertilizers in agricultural field causes more rapid algal growth and decreases DO level much faster than eutrophication from other sources and overfishing. We also look at the mechanisms how fertilizer input rate affects the algal bloom dynamics and DO level. The model can be helpful for the policy makers in determining the influential factors responsible for the bloom formation.

  15. Changes in density and composition of algal assemblages in certain ...

    African Journals Online (AJOL)

    The water purification plants at Virginia and Bothaville, South Africa, experience problems with cyanobacteria and other algae. Their algal assemblages were studied during 2010 and 2011 to determine the dominant species that may pose problems in purification. Cyanobacteria, diatoms and green algae were the dominant ...

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

    KAUST Repository

    Villacorte, Loreen O.; Tabatabai, S. Assiyeh Alizadeh; Anderson, Donald M.; Amy, Gary L.; Schippers, Jan Cornelis; Kennedy, Maria Dolores

    2015-01-01

    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.

  17. Algal communities associated with aquatic macrophytes in some ...

    African Journals Online (AJOL)

    This study describes the algal communities of six ponds colonised by aquatic macrophytes in Nyanza Province, Kenya. Plankton samples were collected from the water column and epiphytic samples from macrophytes such as Azolla, Pistia, Nymphaea, Ipomoea and Ludwigia. Pond pH, temperature, conductivity, ...

  18. Harmful algal blooms of the Southern Benguela current: A review ...

    African Journals Online (AJOL)

    Harmful algal blooms of the Southern Benguela current: A review and appraisal of monitoring from 1989 to 1997. ... The Benguela upwelling system is subjected to blooms of harmful and toxic algae, the incidence and consequences of which are documented here. Red tides are common and usually attributed to members of ...

  19. Monitoring of harmful algal blooms along the Norwegian coast using ...

    African Journals Online (AJOL)

    A Norwegian monitoring system for harmful algal blooms, consisting of an Observer Network, the State Food Hygiene Control Agency, the Oceanographic Company of Norway, the Institute of Marine Research and the Directorate for Fisheries, is reviewed. Potentially harmful algae on the Norwegian coast are found primarily ...

  20. Biological control of Microcystis dominated harmful algal blooms ...

    African Journals Online (AJOL)

    Freshwater resources are now threatened by the presence and increase of harmful algal blooms (HAB) all over the world. The HABs are sometimes a direct result of anthropogenic pollution entering water bodies, such as partially treated nutrient-rich effluents and the leaching of fertilisers and animal wastes. The impact of ...

  1. Increasing the extraction efficiency of algal lipid for biodiesel ...

    African Journals Online (AJOL)

    SAM

    2014-04-09

    Apr 9, 2014 ... biodiesel production: Novel application of algal viruses ... Environmental Virology Cell, Council of Scientific and Industrial ... content, biomass productivity and are more sustainable ... rRNA of microalgae using outsourcing the sequencing services to .... efficiency is concerned, such as development of.

  2. 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.

  3. Algal blooms: a perspective from the coasts of India

    Digital Repository Service at National Institute of Oceanography (India)

    DeSilva, M.S.; Anil, A.C.; Naik, R.K.; DeCosta, P.M.

    Algal blooms have been documented along the west and east coasts of India. A review of bloom occurrences in Indian waters from 1908 to 2009 points out that a total of 101 cases have been reported. A comparison of the bloom cases reported before...

  4. 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

  5. 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

  6. 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.

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

    Science.gov (United States)

    Northern Kentucky University and the U.S. EPA Office of Research Development in Cincinnati Agency are collaborating to develop a harmful algal bloom detection algorithm that estimates the presence of cyanobacteria in freshwater systems by image analysis. Green and blue-green alg...

  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. 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.

  10. Fish Kill Incidents and Harmful Algal Blooms in Omani Waters

    Directory of Open Access Journals (Sweden)

    Hamed Mohammed Al Gheilani

    2011-01-01

    Full Text Available Red tide, one of the harmful algal blooms (HABs is a natural ecological phenomenon and often this event is accompanied by severe impacts on coastal resources, local economies, and public health. The occurrence of red tides has become more frequent in Omani waters in recent years. Some of them caused fish kill, damaged fishery resources and mariculture, threatened the marine environment and the osmosis membranes of desalination plants. However, a number of them have been harmless. The most common dinoflagellate Noctiluca scintillans is associated with the red tide events in Omani waters. Toxic species like Karenia selliformis, Prorocentrum arabianum, and Trichodesmium erythraeum have also been reported recently. Although red tides in Oman have been considered a consequence of upwelling in the summer season (May to September, recent phytoplankton outbreaks in Oman are not restricted to summer. Frequent algal blooms have been reported during winter (December to March. HABs may have contributed to hypoxia and/or other negative ecological impacts.

  11. Effects of fertilizers used in agricultural fields on algal blooms

    DEFF Research Database (Denmark)

    Chakraborty, Subhendu; Tiwari, P. K.; Sasmal, S. K.

    2017-01-01

    of factors and from observation it is difficult to identify the most important one. In the present paper, using a mathematical model we compare the effects of three human induced factors (fertilizer input in agricultural field, eutrophication due to other sources than fertilizers, and overfishing......) on the bloom dynamics and DO level. By applying a sophisticated sensitivity analysis technique, we found that the increasing use of fertilizers in agricultural field causes more rapid algal growth and decreases DO level much faster than eutrophication from other sources and overfishing. We also look...... at the mechanisms how fertilizer input rate affects the algal bloom dynamics and DO level. The model can be helpful for the policy makers in determining the influential factors responsible for the bloom formation....

  12. Didymosphenia geminata: Algal blooms in oligotrophic streams and rivers

    Science.gov (United States)

    Sundareshwar, P. V.; Upadhayay, S.; Abessa, M.; Honomichl, S.; Berdanier, B.; Spaulding, S. A.; Sandvik, C.; Trennepohl, A.

    2011-05-01

    In recent decades, the diatom Didymosphenia geminata has emerged as nuisance species in river systems around the world. This periphytic alga forms large “blooms” in temperate streams, presenting a counterintuitive result: the blooms occur primarily in oligotrophic streams and rivers, where phosphorus (P) availability typically limits primary production. The goal of this study is to examine how high algal biomass is formed under low P conditions. We reveal a biogeochemical process by which D. geminata mats concentrate P from flowing waters. First, the mucopolysaccaride stalks of D. geminata adsorb both iron (Fe) and P. Second, enzymatic and bacterial processes interact with Fe to increase the biological availability of P. We propose that a positive feedback between total stalk biomass and high growth rate is created, which results in abundant P for cell division. The affinity of stalks for Fe in association with iron-phosphorus biogeochemistry suggest a resolution to the paradox of algal blooms in oliogotrophic streams and rivers.

  13. 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.

  14. The attached algal community near Pickering GS: (II)

    International Nuclear Information System (INIS)

    McKinley, S.R.

    1982-01-01

    Environmental parameters correlated with attached algal standing crop are investigated in this report. Three groups were recognized on the basis of standing crop levels and seasonal standing crop patterns. Factors which appeared to influence the separation among the three groups were substrate size and water temperature. Standing crop levels among the discharge transects, intake and areas outside the station were found to be correlated with a combination of parameters. Standing crop levels outside the station were inversely correlated with wind speed but positively correlated with substrate particle size and depth. Algal standing crop at the intake also was inversely correlated with wind speed. Differences in standing crop levels between the intake and areas outside the station may have been attributed to substrate particle size. Low standing crop level among the discharge transects may have been attributed to higher current velocities and periodically to high water temperature

  15. 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.

  16. 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

  17. Marine harmful algal blooms, human health and wellbeing

    DEFF Research Database (Denmark)

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

    2016-01-01

    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...... maintaining intensive, multidisciplinary and collaborative scientific research, and strengthening the coordination with stakeholders, policymakers and the general public. Here we provide an overview of different aspects of the HABs phenomena, an important element of the intrinsic links between oceans...

  18. Conversion of Small Algal Oil Sample to JP-8

    Science.gov (United States)

    2012-01-01

    cracking of Algal Oil to SPK Hydroprocessing Lab Plant uop Nitrogen Hydrogen Product ., __ Small Scale Lab Hydprocessing plant - Down flow trickle ... bed configuration - Capable of retaining 25 cc of catalyst bed Meter UOP ·CONFIDENTIAL File Number The catalytic deoxygenation stage of the...content which combined with the samples acidity, is a challenge to reactor metallurgy. None the less, an attempt was made to convert this sample to

  19. Are all red algal parasites cut from the same cloth?

    Directory of Open Access Journals (Sweden)

    Eric D. Salomaki

    2014-12-01

    Full Text Available Parasitism is a common life strategy throughout the eukaryotic tree of life. Many devastating human pathogens, including the causative agents of malaria and toxoplasmosis, have evolved from a photosynthetic ancestor. However, how an organism transitions from a photosynthetic to a parasitic life history strategy remains mostly unknown. This is largely because few systems present the opportunity to make meaningful comparisons between a parasite and a close free-living relative. Parasites have independently evolved dozens of times throughout the Florideophyceae (Rhodophyta, and often infect close relatives. The accepted evolutionary paradigm proposes that red algal parasites arise by first infecting a close relative and over time diversify and infect more distantly related species. This provides a natural evolutionary gradient of relationships between hosts and parasites that share a photosynthetic common ancestor. Elegant microscopic work in the late 20th century provided detailed insight into the infection cycle of red algal parasites and the cellular interactions between parasites and their hosts. Those studies led to the use of molecular work to further investigate the origins of the parasite organelles and reveal the evolutionary relationships between hosts and their parasites. Here we synthesize the research detailing the infection methods and cellular interactions between red algal parasites and their hosts. We offer an alternative hypothesis to the current dogma of red algal parasite evolution and propose that red algae can adopt a parasitic life strategy through multiple evolutionary pathways, including direct infection of distant relatives. Furthermore, we highlight potential directions for future research to further evaluate parasite evolution in red algae.

  20. The paradox of algal blooms in oligotrophic waters

    Science.gov (United States)

    Sundareshwar, P. V.; Upadhyay, S.; Abessa, M. B.; Honomichl, S.; Berdanier, B.; Spaulding, S.; Sandvik, C.; Trennepohl, A.

    2010-12-01

    Nutrient inputs to streams and lakes, primarily from anthropogenic sources, lead to eutrophic conditions that favor algal blooms with undesirable consequences. In contrast, low nutrient or oligotrophic waters rarely support algal blooms; such ecosystems are typically lower in productivity. Since the mid-1980’s however, the diatom Didymosphenia geminata has dramatically expanded its range colonizing oligotrophic rivers worldwide with blooms appearing as thick benthic mats. This recent global occurrence of Didymosphenia geminata blooms in temperate rivers has been perplexing in its pace of spread and the paradoxical nature of the nuisance growths. The blooms occur primarily in oligotrophic flowing waters, where phosphorus (P) availability often limits primary production. We present a biogeochemical process by which D. geminata mats adsorb both P and iron (Fe) from flowing waters and make P available for cellular uptake. The adsorbed P becomes bioavailable through biogeochemical processes that occur within the mat. The biogeochemical processes observed here while well accepted in benthic systems are novel for algal blooms in lotic habits. Enzymatic and bacterial processes such as Fe and sulfate reduction can release the adsorbed P and increase its bioavailability, creating a positive feedback between total stalk biomass and nutrient availability. Stalk affinity for Fe, Fe-P biogeochemistry, and interaction between watershed processes and climatic setting explain the paradoxical blooms, and the recent global spread of this invasive aquatic species. At a broader scale the study also implies that such algal blooms in oligotrophic environments can fundamentally alter the retention and longitudinal transfer of important nutrients such as P in streams and rivers.

  1. Efficient algal bioassay based on short-term photosynthetic response

    International Nuclear Information System (INIS)

    Giddings, J.M.; Stewart, A.J.; O'Neill, R.V.; Gardner, R.H.

    1983-01-01

    A procedure is described for measuring the effects of toxicants on algal photosynthesis (carbon-14 bicarbonate (H 14 CO 3 )uptake) in 4-h experiments. The results for individual aromatic compounds and the water-soluble fraction (WSF) of a synthetic oil are presented as examples of applications of the bioassay. The toxicity of the WSF varied among the seven algal species tested, and the responses of some species were pH-dependent. With Selenastrum capricornutum as the test organism, the bioassay results were unaffected by variations in pH from 7.0 to 9.0, light intensity from 40 to 200 μeinsteins m -2 s -1 , culture density up to 0.5 mg chlorophyll a per litre, and agitation up to 100 rpm. The photosynthesis bioassay is simpler and faster (4 h versus 4 to 14 days), uses smaller culture volumes, and requires less space than static culture-growth tests. One person can conveniently test four materials per day, and the entire procedure, including preparation, exposure, and analysis, takes less than two days. The short incubation time reduces bottle effects such as pH changes, accumulation of metabolic products, nutrient depletion, and bacterial growth. Processes that remove or alter the test materials are also minimized. The data presented here indicate that algal photosynthesis is inhibited at toxicant concentrations similar to those that cause acute effects in aquatic animals. A model of a pelagic ecosystem is used to demonstrate that even temporary (seven-day) inhibition of algal photosynthesis can have a measurable impact on other trophic levels, particularly if the other trophic levels are also experiencing toxic effects. 25 references, 6 figures, 1 table

  2. Ultrasound pretreatment of filamentous algal biomass for enhanced biogas production.

    Science.gov (United States)

    Lee, Kwanyong; Chantrasakdakul, Phrompol; Kim, Daegi; Kong, Mingeun; Park, Ki Young

    2014-06-01

    The filamentous alga Hydrodictyon reticulatum harvested from a bench-scale wastewater treatment pond was used to evaluate biogas production after ultrasound pretreatment. The effects of ultrasound pretreatment at a range of 10-5000 J/mL were tested with harvested H. reticulatum. Cell disruption by ultrasound was successful and showed a higher degree of disintegration at a higher applied energy. The range of 10-5000 J/mL ultrasound was able to disintegrated H. reticulatum and the soluble COD was increased from 250 mg/L to 1000 mg/L at 2500 J/mL. The disintegrated algal biomass was digested for biogas production in batch experiments. Both cumulative gas generation and volatile solids reduction data were obtained during the digestion. Cell disintegration due to ultrasound pretreatment increased the specific biogas production and degradation rates. Using the ultrasound approach, the specific methane production at a dose of 40 J/mL increased up to 384 mL/g-VS fed that was 2.3 times higher than the untreated sample. For disintegrated samples, the volatile solids reduction was greater with increased energy input, and the degradation increased slightly to 67% at a dose of 50 J/mL. The results also indicate that disintegration of the algal cells is the essential step for efficient anaerobic digestion of algal biomass. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Study of cnidarian-algal symbiosis in the "omics" age.

    Science.gov (United States)

    Meyer, Eli; Weis, Virginia M

    2012-08-01

    The symbiotic associations between cnidarians and dinoflagellate algae (Symbiodinium) support productive and diverse ecosystems in coral reefs. Many aspects of this association, including the mechanistic basis of host-symbiont recognition and metabolic interaction, remain poorly understood. The first completed genome sequence for a symbiotic anthozoan is now available (the coral Acropora digitifera), and extensive expressed sequence tag resources are available for a variety of other symbiotic corals and anemones. These resources make it possible to profile gene expression, protein abundance, and protein localization associated with the symbiotic state. Here we review the history of "omics" studies of cnidarian-algal symbiosis and the current availability of sequence resources for corals and anemones, identifying genes putatively involved in symbiosis across 10 anthozoan species. The public availability of candidate symbiosis-associated genes leaves the field of cnidarian-algal symbiosis poised for in-depth comparative studies of sequence diversity and gene expression and for targeted functional studies of genes associated with symbiosis. Reviewing the progress to date suggests directions for future investigations of cnidarian-algal symbiosis that include (i) sequencing of Symbiodinium, (ii) proteomic analysis of the symbiosome membrane complex, (iii) glycomic analysis of Symbiodinium cell surfaces, and (iv) expression profiling of the gastrodermal cells hosting Symbiodinium.

  4. 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. © 2015 Wiley Periodicals, Inc.

  5. Algal remediation of CO₂ and nutrient discharges: A review.

    Science.gov (United States)

    Judd, Simon; van den Broeke, Leo J P; Shurair, Mohamed; Kuti, Yussuf; Znad, Hussein

    2015-12-15

    The recent literature pertaining to the application of algal photobioreactors (PBRs) to both carbon dioxide mitigation and nutrient abatement is reviewed and the reported data analysed. The review appraises the influence of key system parameters on performance with reference to (a) the absorption and biological fixation of CO2 from gaseous effluent streams, and (b) the removal of nutrients from wastewaters. Key parameters appraised individually with reference to CO2 removal comprise algal speciation, light intensity, mass transfer, gas and hydraulic residence time, pollutant (CO2 and nutrient) loading, biochemical and chemical stoichiometry (including pH), and temperature. Nutrient removal has been assessed with reference to hydraulic residence time and reactor configuration, along with C:nutrient ratios and other factors affecting carbon fixation, and outcomes compared with those reported for classical biological nutrient removal (BNR). Outcomes of the review indicate there has been a disproportionate increase in algal PBR research outputs over the past 5-8 years, with a significant number of studies based on small, bench-scale systems. The quantitative impacts of light intensity and loading on CO2 uptake are highly dependent on the algal species, and also affected by solution chemical conditions such as temperature and pH. Calculations based on available data for biomass growth rates indicate that a reactor CO2 residence time of around 4 h is required for significant CO2 removal. Nutrient removal data indicate residence times of 2-5 days are required for significant nutrient removal, compared with PBR configuration (the high rate algal pond, HRAP) means that its footprint is at least two orders of magnitude greater than a classical BNR plant. It is concluded that the combined carbon capture/nutrient removal process relies on optimisation of a number of process parameters acting synergistically, principally microalgal strain, C:N:P load and balance, CO2 and liquid

  6. Water-stable diblock polystyrene-block-poly(2-vinyl pyridine) and diblock polystyrene-block-poly(methyl methacrylate) cylindrical patterned surfaces inhibit settlement of zoospores of the green alga Ulva.

    Science.gov (United States)

    Grozea, Claudia M; Gunari, Nikhil; Finlay, John A; Grozea, Daniel; Callow, Maureen E; Callow, James A; Lu, Zheng-Hong; Walker, Gilbert C

    2009-04-13

    Nanopatterned surfaces with hydrophobic and hydrophilic domains were produced using the diblock copolymer polystyrene-block-poly(2-vinyl pyridine) (PS-b-P2VP) and polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA). The PS-b-P2VP diblock copolymer, mixed with the cross-linker benzophenone and spin-coated onto silicon wafers, showed self-assembled cylindrical structures, which were retained after UV treatment for cross-linking. The thin films displayed cylindrical domains after immersion in water. This study shows that pattern retention in water is possible for a long period of time, at least for two weeks in pure water and three weeks in artificial seawater. The PS-b-PMMA diblock showed self-assembled cylindrical structures. PS-b-P2VP and PS-b-PMMA cylindrical patterned surfaces showed reduced settlement of zoospores of the green alga Ulva compared to unpatterned surfaces. The copolymers were investigated using atomic force microscopy and X-ray photoelectron spectroscopy.

  7. Advancing Commercialization of Algal Biofuel through Increased Biomass Productivity and Technical Integration

    Energy Technology Data Exchange (ETDEWEB)

    Anton, David [Cellana, LLC, Kailua-Kona, HI (United States)

    2016-12-31

    The proposed project built on the foundation of over several years years of intensive and ground-breaking R&D work at Cellana's Kona Demonstration Facility (KDF). Phycological and engineering solutions were provided to tackle key cultivation issues and technical barriers limiting algal biomass productivity identified through work conducted outdoors at industrial (1 acre) scale. The objectives of this project were to significantly improve algal biomass productivity and reduce operational cost in a seawater-based system, using results obtained from two top-performing algal strains as the baseline while technically advancing and more importantly, integrating the various unit operations involved in algal biomass production, processing, and refining.

  8. Expanded algal cultivation can reverse key planetary boundary transgressions

    Directory of Open Access Journals (Sweden)

    Dean Calahan

    2018-02-01

    Full Text Available Humanity is degrading multiple ecosystem services, potentially irreversibly. Two of the most important human impacts are excess agricultural nutrient loading in our fresh and estuarine waters and excess carbon dioxide in our oceans and atmosphere. Large-scale global intervention is required to slow, halt, and eventually reverse these stresses. Cultivating attached polyculture algae within controlled open-field photobioreactors is a practical technique for exploiting the ubiquity and high primary productivity of algae to capture and recycle the pollutants driving humanity into unsafe regimes of biogeochemical cycling, ocean acidification, and global warming. Expanded globally and appropriately distributed, algal cultivation is capable of removing excess nutrients from global environments, while additionally sequestering appreciable excess carbon. While obviously a major capital and operational investment, such a project is comparable in magnitude to the construction and maintenance of the global road transportation network. Beyond direct amelioration of critical threats, expanded algal cultivation would produce a major new commodity flow of biomass, potentially useful either as a valuable organic commodity itself, or used to reduce the scale of the problem by improving soils, slowing or reversing the loss of arable land. A 100 year project to expand algal cultivation to completely recycle excess global agricultural N and P would, when fully operational, require gross global expenses no greater than $2.3 × 1012 yr−1, (3.0% of the 2016 global domestic product and less than 1.9 × 107 ha (4.7 × 107 ac, 0.38% of the land area used globally to grow food. The biomass generated embodies renewable energy equivalent to 2.8% of global primary energy production.

  9. 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.

  10. 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.

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

    International Nuclear Information System (INIS)

    Vilar, Vitor J.P.; Botelho, Cidalia M.S.; Pinheiro, Jose P.S.; Domingos, Rute F.; Boaventura, Rui A.R.

    2009-01-01

    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 =5.0,5.3and4.4;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

  12. 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

  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. Bioconversion of poultry droppings for biogas and algal production

    Energy Technology Data Exchange (ETDEWEB)

    Mahadevaswamy, M.; Venkataraman, L.V.

    1986-01-01

    An integrated system for the bioconversion of poultry droppings for biogas production and utilization of the effluent for the production of the blue-green alga Spirulina platensis was studied. Poultry droppings produced 0.54 cubic m of biogas per kilogran of Total Solids (TS). The 2% TS biogas plant effluent as sole nutrient medium for Spirulina yielded 7-8 g dry algae a day. The biomass was harvested by filtration. The sundried algal biomass has been used as a poultry feed component. In economic terms the system appears promising. 18 references.

  15. 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.

  16. A trait-based framework for stream algal communities.

    Science.gov (United States)

    Lange, Katharina; Townsend, Colin Richard; Matthaei, Christoph David

    2016-01-01

    The use of trait-based approaches to detect effects of land use and climate change on terrestrial plant and aquatic phytoplankton communities is increasing, but such a framework is still needed for benthic stream algae. Here we present a conceptual framework of morphological, physiological, behavioural and life-history traits relating to resource acquisition and resistance to disturbance. We tested this approach by assessing the relationships between multiple anthropogenic stressors and algal traits at 43 stream sites. Our "natural experiment" was conducted along gradients of agricultural land-use intensity (0-95% of the catchment in high-producing pasture) and hydrological alteration (0-92% streamflow reduction resulting from water abstraction for irrigation) as well as related physicochemical variables (total nitrogen concentration and deposited fine sediment). Strategic choice of study sites meant that agricultural intensity and hydrological alteration were uncorrelated. We studied the relationships of seven traits (with 23 trait categories) to our environmental predictor variables using general linear models and an information-theoretic model-selection approach. Life form, nitrogen fixation and spore formation were key traits that showed the strongest relationships with environmental stressors. Overall, FI (farming intensity) exerted stronger effects on algal communities than hydrological alteration. The large-bodied, non-attached, filamentous algae that dominated under high farming intensities have limited dispersal abilities but may cope with unfavourable conditions through the formation of spores. Antagonistic interactions between FI and flow reduction were observed for some trait variables, whereas no interactions occurred for nitrogen concentration and fine sediment. Our conceptual framework was well supported by tests of ten specific hypotheses predicting effects of resource supply and disturbance on algal traits. Our study also shows that investigating a

  17. Inhibitory effect of marine green algal extracts on germination of Lactuca sativa seeds.

    Science.gov (United States)

    Choi, Jae-Suk; Choi, In Soon

    2016-03-01

    The allelopathic potential of nine green seaweed species was examined based on germination and seedling growth of lettuce (Lactuca sativa L.). Out of nine methanol extracts, Capsosiphon fulvescens and Monostroma nitidum extracts completely inhibited germination of L. sativa at 4 mg/filter paper after 24 hr of treatment. Water extracts of these seaweeds generally showed low anti-germination activities than methanol extracts. Of the nine water extracts, Enteromorpha linza extract completely inhibited L. sativa germination at 16 mg/filter paper after 24 hrs. To identify the primary active compounds, C. fulvescens. powder was successively fractionated according to polarity, and the main active agents against L. sativa were determined to be lipids (0.0% germination at 0.5 mg of lipids/paper disc). According to these results, extracts of C. fulvescens can be used to develop natural herbicidal agents and manage terrestrial weeds.

  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. Compatibility of hydroxypropyl-β-cyclodextrin with algal toxicity bioassays

    International Nuclear Information System (INIS)

    Fai, Patricia Bi; Grant, Alastair; Reid, Brian J.

    2009-01-01

    Numerous reports have indicated that hydrophobic organic compound bioaccessibility in sediment and soil can be determined by extraction using aqueous hydroxypropyl-β-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 4 ), with IC50 values of 0.82 μM and 0.85 μM, 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

  1. 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. © 2014 Elsevier Inc. All rights reserved.

  2. Algal Blooms and Cyanotoxins in Jordan Lake, North Carolina

    Directory of Open Access Journals (Sweden)

    Daniel Wiltsie

    2018-02-01

    Full Text Available The eutrophication of waterways has led to a rise in cyanobacterial, harmful algal blooms (CyanoHABs worldwide. The deterioration of water quality due to excess algal biomass in lakes has been well documented (e.g., water clarity, hypoxic conditions, but health risks associated with cyanotoxins remain largely unexplored in the absence of toxin information. This study is the first to document the presence of dissolved microcystin, anatoxin-a, cylindrospermopsin, and β-N-methylamino-l-alanine in Jordan Lake, a major drinking water reservoir in North Carolina. Saxitoxin presence was not confirmed. Multiple toxins were detected at 86% of the tested sites and during 44% of the sampling events between 2014 and 2016. Although concentrations were low, continued exposure of organisms to multiple toxins raises some concerns. A combination of discrete sampling and in-situ tracking (Solid Phase Adsorption Toxin Tracking [SPATT] revealed that microcystin and anatoxin were the most pervasive year-round. Between 2011 and 2016, summer and fall blooms were dominated by the same cyanobacterial genera, all of which are suggested producers of single or multiple cyanotoxins. The study’s findings provide further evidence of the ubiquitous nature of cyanotoxins, and the challenges involved in linking CyanoHAB dynamics to specific environmental forcing factors are discussed.

  3. Algal Blooms and Cyanotoxins in Jordan Lake, North Carolina.

    Science.gov (United States)

    Wiltsie, Daniel; Schnetzer, Astrid; Green, Jason; Vander Borgh, Mark; Fensin, Elizabeth

    2018-02-24

    The eutrophication of waterways has led to a rise in cyanobacterial, harmful algal blooms (CyanoHABs) worldwide. The deterioration of water quality due to excess algal biomass in lakes has been well documented (e.g., water clarity, hypoxic conditions), but health risks associated with cyanotoxins remain largely unexplored in the absence of toxin information. This study is the first to document the presence of dissolved microcystin, anatoxin-a, cylindrospermopsin, and β- N -methylamino-l-alanine in Jordan Lake, a major drinking water reservoir in North Carolina. Saxitoxin presence was not confirmed. Multiple toxins were detected at 86% of the tested sites and during 44% of the sampling events between 2014 and 2016. Although concentrations were low, continued exposure of organisms to multiple toxins raises some concerns. A combination of discrete sampling and in-situ tracking (Solid Phase Adsorption Toxin Tracking [SPATT]) revealed that microcystin and anatoxin were the most pervasive year-round. Between 2011 and 2016, summer and fall blooms were dominated by the same cyanobacterial genera, all of which are suggested producers of single or multiple cyanotoxins. The study's findings provide further evidence of the ubiquitous nature of cyanotoxins, and the challenges involved in linking CyanoHAB dynamics to specific environmental forcing factors are discussed.

  4. 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.

  5. Algal Blooms and Cyanotoxins in Jordan Lake, North Carolina

    Science.gov (United States)

    Wiltsie, Daniel; Schnetzer, Astrid; Green, Jason; Vander Borgh, Mark; Fensin, Elizabeth

    2018-01-01

    The eutrophication of waterways has led to a rise in cyanobacterial, harmful algal blooms (CyanoHABs) worldwide. The deterioration of water quality due to excess algal biomass in lakes has been well documented (e.g., water clarity, hypoxic conditions), but health risks associated with cyanotoxins remain largely unexplored in the absence of toxin information. This study is the first to document the presence of dissolved microcystin, anatoxin-a, cylindrospermopsin, and β-N-methylamino-l-alanine in Jordan Lake, a major drinking water reservoir in North Carolina. Saxitoxin presence was not confirmed. Multiple toxins were detected at 86% of the tested sites and during 44% of the sampling events between 2014 and 2016. Although concentrations were low, continued exposure of organisms to multiple toxins raises some concerns. A combination of discrete sampling and in-situ tracking (Solid Phase Adsorption Toxin Tracking [SPATT]) revealed that microcystin and anatoxin were the most pervasive year-round. Between 2011 and 2016, summer and fall blooms were dominated by the same cyanobacterial genera, all of which are suggested producers of single or multiple cyanotoxins. The study’s findings provide further evidence of the ubiquitous nature of cyanotoxins, and the challenges involved in linking CyanoHAB dynamics to specific environmental forcing factors are discussed. PMID:29495289

  6. 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.

  7. Microencapsulation of Algal Oil Using Spray Drying Technology

    Directory of Open Access Journals (Sweden)

    Xueshan Pan

    2018-01-01

    Full Text Available This work aims at developing a process of microencapsulation of algal oil containing ≥40 % docosahexaenoic acid (DHA using spray drying technology. Purity Gum® 2000 and Capsul®, both obtained from waxy corn starch, were chosen as the encapsulation materials. The effects of emulsification conditions on the droplet size, stability, viscosity and surface tension, and the effects of spraying conditions on the particle size, moisture content and surface oil content were investigated successively. The morphology of emulsion droplets and the microcapsules was observed by optical microscope and scanning electron micro scopy. The results showed that the produced spherical microcapsules were smooth and free of pores, cracks, and surface indentation when shear velocity was 8.63 m/s in the first step of emulsification, homogenization pressure was 1.75·10˄8 Pa and number of passes through homogenization unit was six for fine emulsification, rotational speed of spray disk was 400 s-1, and air inlet temperature was 170 °C. Therefore, it was concluded that the emulsification and encapsulation of algal oil containing DHA with above process was feasible.

  8. Recycling produced water for algal cultivation for biofuels

    Energy Technology Data Exchange (ETDEWEB)

    Neal, Justin N. [Los Alamos National Laboratory; Sullivan, Enid J. [Los Alamos National Laboratory; Dean, Cynthia A. [Los Alamos National Laboratory; Steichen, Seth A. [Los Alamos National Laboratory

    2012-08-09

    Algal growth demands a continuous source of water of appropriate salinity and nutritional content. Fresh water sources are scarce in the deserts of the Southwestern United States, hence, salt water algae species are being investigated as a renewable biofuel source. The use of produced water from oil wells (PW) could offset the demand for fresh water in cultivation. Produced water can contain various concentrations of dissolved solids, metals and organic contaminants and often requires treatment beyond oil/water separation to make it suitable for algae cultivation. The produced water used in this study was taken from an oil well in Jal, New Mexico. An F/2-Si (minus silica) growth media commonly used to cultivate Nannochloropsis salina 1776 (NS 1776) was prepared using the produced water (F/2-Si PW) taking into account the metals and salts already present in the water. NS 1776 was seeded into a bioreactor containing 5L of the (F/2-Si PW) media. After eleven days the optical density at 750 nm (an indicator of algal growth) increased from 0 to 2.52. These results indicate algae are able to grow, though inhibited when compared with non-PW media, in the complex chemical conditions found in produced water. Savings from using nutrients present in the PW, such as P, K, and HCO{sub 3}{sup -}, results in a 44.38% cost savings over fresh water to mix the F/2-Si media.

  9. Effect of algal density in bead, bead size and bead concentrations ...

    African Journals Online (AJOL)

    Effect of algal density in bead, bead size and bead concentrations on wastewater nutrient removal. ... African Journal of Biotechnology ... The bioreactor containing algal beads (4 mm diameter) with 1.5 x 106 cells bead-1 (cell stocking) at concentration of 10.66 beads ml-1 wastewater (1:3 bead: wastewater, v/v) achieved ...

  10. Biofouling in capillary and spiral wound membranes facilitated by marine algal bloom

    NARCIS (Netherlands)

    Villacorte, L.O.; Ekowati, Y.; Calix-Ponce, H.N.; Kisielius, V.; Kleijn, J.M.; Vrouwenvelder, J.S.; Schippers, J.C.; Kennedy, M.D.

    2017-01-01

    Algal-derived organic matter (AOM), particularly transparent exopolymer particles, has been suspected to facilitate biofilm development in membrane systems (e.g., seawater reverse osmosis). This study demonstrates the possible role of AOM on biofouling in membrane systems affected by marine algal

  11. 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…

  12. 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.

  13. Mathematical-statistical model for analysis of Ulva algal net photosynthesis in Venice lagoon

    International Nuclear Information System (INIS)

    Izzo, G.; Rizzo, V.; Bella, A.; Picci, M.; Giordano, P.

    1996-08-01

    The algal net photosynthesis, an important factor for the characterization of water quality in Venice lagoon, has been studied experimentally providing a mathematical model, validated by using statistical methods. This model relates oxygen production with irradiance, according to a well known law in biological literature. Its observed an inverted proportion between algal oxygen production and temperature, thus seasonality

  14. Data from: Evidence for water-mediated mechanisms in coral–algal interactions

    NARCIS (Netherlands)

    Jorissen, Hendrikje; Skinner, Christina; Osinga, R.; Beer, De Dirk; Nugues, Maggy M.

    2016-01-01

    Although many coral reefs have shifted from coral-to-algal dominance, the consequence of such a transition for coral–algal interactions and their underlying mechanisms remain poorly understood. At the microscale, it is unclear how diffusive boundary layers (DBLs) and surface oxygen concentrations at

  15. Evidence for water-mediated mechanisms in coral–algal interactions

    NARCIS (Netherlands)

    Jorissen, Hendrikje; Skinner, Christina; Osinga, Ronald; Beer, De Dirk; Nugues, Maggy M.

    2016-01-01

    Although many coral reefs have shifted from coral-to-algal dominance, the consequence of such a transition for coral–algal interactions and their underlying mechanisms remain poorly understood. At the microscale, it is unclear how diffusive boundary layers (DBLs) and surface oxygen concentrations

  16. HARMFUL ALGAL BLOOMS IN THE MEDITERRANEAN SEA: EFFECTS ON HUMAN HEALTH.

    Directory of Open Access Journals (Sweden)

    Margherita Ferrante

    2013-01-01

    Full Text Available A harmful algal bloom (HAB is defined as a bloom that has deleterious effects on plants, animals or humans. Marine algal toxins are responsible for an array of human illnesses associated with consumption of seafood or exposure to aerosolized toxins. The effects of algal toxins are generally observed as acute intoxications, whereas the environmental health effects of chronic exposure to low levels of algal toxins are, to date, only poorly documented and an emerging issue. Consumption of seafood contaminated with algal toxins can result in five types of seafood poisoning syndromes: paralytic shellfish poisoning, neurotoxic shellfish poisoning, amnesic shellfish poisoning, diarrhetic shellfish poisoning and ciguatera fish poisoning. The aim of this paper is to provide an overview on HAB-related issues in the Mediterranean Sea.

  17. Possible importance of algal toxins in the Salton Sea, California

    Science.gov (United States)

    Reifel, K.M.; McCoy, M.P.; Rocke, T.E.; Tiffany, M.A.; Hurlbert, S.H.; Faulkner, D.J.

    2002-01-01

    In response to wildlife mortality including unexplained eared grebe (Podiceps nigricollis) die-off events in 1992 and 1994 and other mortality events including large fish kills, a survey was conducted for the presence of algal toxins in the Salton Sea. Goals of this survey were to determine if and when algal toxins are present in the Salton Sea and to describe the phytoplankton composition during those times. A total of 29 samples was collected for toxicity analysis from both nearshore and midlake sites visited biweekly from January to December 1999. Dinoflagellates and diatoms dominated most samples, but some were dominated by a prymnesiophyte (Pleurochrysis pseudoroscoffensis) or a raphidophyte (Chattonella marina). Several types of blooms were observed and sampled. The dinoflagellate Gyrodinium uncatenum formed an extensive, dense (up to 310 000 cells ml−1) and long-lasting bloom during the winter in 1999. A coccolithophorid, Pleurochrysis pseudoroscoffensis, occurred at high densities in surface films and nearshore areas during the spring and summer of 1999. These surface films also contained high densities of one or two other species (an unidentified scrippsielloid, Heterocapsa niei, Chattonella marina). Localized blooms were also observed in the Salton Sea. An unknown small dinoflagellate reached high densities (110 000 cells ml−1) inside Varner Harbor, and an unidentified species of Gymnodinium formed a dense (270 000 cells ml−1) band along part of the southern shoreline during the summer. Three species known to produce toxins in other systems were found. Protoceratium reticulatum (=Gonyaulax grindleyi) and Chattonella marina were found in several samples taken during summer months, and Prorocentrum minimum was found in low densities in several samples. Extracts of most samples, including those containing known toxic species, showed a low level (Salton Sea, no evidence gathered in this study suggests that algal toxins are present

  18. Algal growth inhibition test results of 425 organic chemical substances

    DEFF Research Database (Denmark)

    Kusk, Kresten Ole; Christensen, Anne Munch; Nyholm, Niels

    2018-01-01

    The toxicity towards the algal species Pseudokirchneriella subcapitata of 425 organic chemical substances was tested in a growth inhibition test. Precautions were taken to prevent loss of the compounds from the water phase and the test system (closed test system, low biomass, shorter test duration......, silanized glass) and to keep pH constant by applying a higher alkalinity. Chemical phase distribution was modelled taking ionization, volatilisation, and adsorption to glass and biomass into consideration. If the modelled water concentration was below 90% of the nominal concentration the calculated EC...... values were corrected accordingly. The model helped to identify substances, where the calculated water concentration was too uncertain. Substances covering a wide range of physical-chemical properties and different modes of action were tested. Median effect concentrations (EC50) lower than 1000 mg/L were...

  19. 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.

  20. Heterologous expression of an algal hydrogenase in a heterocystous cyanobacterium

    Energy Technology Data Exchange (ETDEWEB)

    Thorsten Heidorn; Peter Lindblad [Dept. of Physiological Botany, Uppsala University, Villavogen 6, SE-752 36 Uppsala, (Sweden)

    2006-07-01

    For the expression of an active algal [FeFe] hydrogenase in the heterocystous cyanobacterium Nostoc punctiforme A TCC 29133 the Chlamydomonas reinhardtii hydrogenase gene hydA1 and the accessory genes hydEF and hydG are to be introduced into the cyanobacteria cells. The genes were amplified by PCR from EST clones, cloned into the cloning vector pBluescript SK+ and sequenced. An expression vector for multi-cistronic cloning, based on pSCR202, was constructed and for a functional test GFP was inserted as a reporter gene. The GFP construct was transformed into Nostoc punctiforme A TCC 29133 by electroporation and expression of GFP was visualized by fluorescence microscopy. (authors)

  1. Heterologous expression of an algal hydrogenase in a heterocystous cyanobacterium

    International Nuclear Information System (INIS)

    Thorsten Heidorn; Peter Lindblad

    2006-01-01

    For the expression of an active algal [FeFe] hydrogenase in the heterocystous cyanobacterium Nostoc punctiforme A TCC 29133 the Chlamydomonas reinhardtii hydrogenase gene hydA1 and the accessory genes hydEF and hydG are to be introduced into the cyanobacteria cells. The genes were amplified by PCR from EST clones, cloned into the cloning vector pBluescript SK+ and sequenced. An expression vector for multi-cistronic cloning, based on pSCR202, was constructed and for a functional test GFP was inserted as a reporter gene. The GFP construct was transformed into Nostoc punctiforme A TCC 29133 by electroporation and expression of GFP was visualized by fluorescence microscopy. (authors)

  2. Oceans and Human Health: Microplastics and Harmful Algal Bloom

    International Nuclear Information System (INIS)

    Sombrito, Elvira Z.

    2015-01-01

    Traditionally the focus of research and concern of environmental studies in the marine system is the impact of human activities in the ocean: the sources, distribution and fate of pollutants resulting from human activities. More recently, there has been recognition of the potential direct impact health can come from eating contaminated seafood, swimming in polluted water, and exposure to toxins from harmful algal blooms. This paper will present two areas of concern that illustrates the fact that the health of the oceans and the health of humans go hand in hand: chemical pollution from plastics in the ocean and harmful alga bloom. The nuclear methodologies than can be useful in these areas will also be introduced. It is hoped that through the recognition of the inter-dependence of the health of both humans and the oceans, efforts will be made to restore and preserve the oceans. (author)

  3. Animal behaviour and algal camouflage jointly structure predation and selection.

    Science.gov (United States)

    Start, Denon

    2018-05-01

    Trait variation can structure interactions between individuals, thus shaping selection. Although antipredator strategies are an important component of many aquatic systems, how multiple antipredator traits interact to influence consumption and selection remains contentious. Here, I use a common larval dragonfly (Epitheca canis) and its predator (Anax junius) to test for the joint effects of activity rate and algal camouflage on predation and survival selection. I found that active and poorly camouflaged Epitheca were more likely to be consumed, and thus, survival selection favoured inactive and well-camouflaged individuals. Notably, camouflage dampened selection on activity rate, likely by reducing attack rates when Epitheca encountered a predator. Correlational selection is therefore conferred by the ecological interaction of traits, rather than by opposing selection acting on linked traits. I suggest that antipredator traits with different adaptive functions can jointly structure patterns of consumption and selection. © 2018 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2018 European Society For Evolutionary Biology.

  4. Biotreatment of industrial wastewater by selected algal-bacterial consortia

    Energy Technology Data Exchange (ETDEWEB)

    Safonova, E.; Kvitko, K.V. [St. Petersburg State University, Biological Institute, Oranienbaum Chaussee 2, Old Peterhof, 198504 St. Petersburg (Russian Federation); Iankevitch, M.I.; Surgko, L.F.; Afti, I.A. [Ecoprom Ltd., Gruzovoi Proezd 13, Obukhovo, 192289 St. Petersburg (Russian Federation); Reisser, W. [Universitaet Leipzig, Botanisches Institut, Johannisallee 21-23, D-04103 Leipzig (Germany)

    2004-08-01

    A new approach for remediation processes in highly polluted environments is presented. The efficiency of algal-bacterial associations for the remediation of industrial wastewater of a pond in Samara, Russia, was investigated. After screening of algae and bacteria for the resistance to the wastewater the following strains were selected: the algal strains Chlorella sp. ES-13, Chlorella sp. ES-30, Scenedesmus obliquus ES-55, several Stichococcus strains (ES-19, ES-85, ES-86, ES-87, ES-88), and Phormidium sp. ES-90 and the bacterial strains Rhodococcus sp. Ac-1267, Kibdelosporangium aridum 754 as well as two unidentified bacterial strains (St-1, St-2) isolated from the collector pond. All the strains listed above were immobilized onto various solid carriers (capron fibers for algae; ceramics, capron and wood for bacteria) and used for biotreatment in a pilot installation. The results showed that the selected algae and bacteria formed stable consortia during the degradation of the waste, which was demonstrated for the first time for the green alga Stichococcus. Stichococcus and Phormidium cells attached to capron fibers with the help of slime and formed a matrix. This matrix fixed the bacteria and eukaryotic algae and prevented them from being washed off. A significant decrease in the content of the pollutants was observed: phenols were removed up to 85 %, anionic surface active substances (anionic SAS) up to 73 %, oil spills up to 96 %, copper up to 62 %, nickel up to 62 %, zinc up to 90 %, manganese up to 70 %, and iron up to 64 %. The reduction of the biological oxygen demand (BOD{sub 25}) and the chemical oxygen demand COD amounted to 97 % and 51 %, respectively. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

  5. Epilithic algal assemblages in the Forsmark Biotest basin

    Energy Technology Data Exchange (ETDEWEB)

    Snoeijs, P.

    1987-04-01

    The Forsmark Biotest Basin is an artificial offshore brackish lake, through which the cooling water is led from the Forsmark Nuclear Power Station on the Swedish east coast. The Biotest Basin differs from the Bothnian Sea surrounding it by a temperature elevation of up to 10 degrees C, no ice cover in winter, and an artificial, fast current. At 11 sites in- and outside the basin, benthic algal assemblages on stones in the hydrolittoral belt were sampled every third week during one year. Cover abundances were estimated for all algae occurring on the stones, but for diatoms only when they formed blooms. The results of the vegetation analyses are given. Diversity indices and dominance-diversity curves were computed for each site on the basis of pooled data for the cold season and for the rest of the year. The algae included both unicellular and multicellular forms. In total 88 taxa were distinguished in the species lists: 29 Cyanophyta, 7 Rhodophyta, 1 Chrysophyceae, 9 Fucophyceae, 17 Diatomophyceae and 25 Chlorophyta. In terms of percentage cover-abundance, blue-green and green algae increased with temperature, while red and brown algae and diatoms decreased with temperature in the interval between the minimum (0 degrees C) and the maximum (25.7 degrees C) water temperatures that were measured during the investigation period. Melosira spp. and Nitzschia filiformis proved to be the diatoms most favoured by the cooling water discharge. Lower diversity and greater dominance of one or a few species over the other was caused by thermal discharge at sites with fast-flowing water, but the opposite occurred at sites with quiescent water, mainly due to a greater number and higher abundances of blue-green algal species and thread-like green algae at the latter sites. This report also gives some notes on taxonomy of the encountered species.

  6. 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.

  7. Interaction between local hydrodynamics and algal community in epilithic biofilm.

    Science.gov (United States)

    Graba, Myriam; Sauvage, Sabine; Moulin, Frédéric Y; Urrea, Gemma; Sabater, Sergi; Sanchez-Pérez, José Miguel

    2013-05-01

    Interactions between epilithic biofilm and local hydrodynamics were investigated in an experimental flume. Epilithic biofilm from a natural river was grown over a 41-day period in three sections with different flow velocities (0.10, 0.25 and 0.40 m s(-1) noted LV, IV and HV respectively). Friction velocities u* and boundary layer parameters were inferred from PIV measurement in the three sections and related to the biofilm structure. The results show that there were no significant differences in Dry Mass and Ash-Free Dry Mass (g m(-2)) at the end of experiment, but velocity is a selective factor in algal composition and the biofilms' morphology differed according to differences in water velocity. A hierarchical agglomerative cluster analysis (Bray-Curtis distances) and an Indicator Species Analysis (IndVal) showed that the indicator taxa were Fragilaria capucina var. mesolepta in the low-velocity (u*. = 0.010-0.012 m s(-1)), Navicula atomus, Navicula capitatoradiata and Nitzschia frustulum in the intermediate-velocity (u*. = 0.023-0.030 m s(-1)) and Amphora pediculus, Cymbella proxima, Fragilaria capucina var. vaucheriae and Surirella angusta in the high-velocity (u*. = 0.033-0.050 m s(-1)) sections. A sloughing test was performed on 40-day-old biofilms in order to study the resistance of epilithic biofilms to higher hydrodynamic regimes. The results showed an inverse relationship between the proportion of detached biomass and the average value of friction velocity during growth. Therefore, water velocity during epilithic biofilm growth conditioned the structure and algal composition of biofilm, as well as its response (ability to resist) to higher shear stresses. This result should be considered in modelling epilithic biofilm dynamics in streams subject to a variable hydrodynamics regime. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. 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

  9. Algal Growth and Waste Stabilization Ponds Performance Efficiency in a Sub-Tropical Climate

    International Nuclear Information System (INIS)

    Alamgir, A.; Khan, M. A.; Shaukat, S. S.

    2016-01-01

    Both irrigation and potable water are in diminutive supply in most of the developing countries particularly those situated in tropical and subtropical regions where, often untreated wastewater is utilized for the purpose of irrigation. Treated wastewater has proved to be a potential asset serving as an alternate source for the expansion of irrigated agriculture. Waste stabilization ponds (WSP) are considered as less costly and effective substitute for the wastewater water treatment in tropics. The principle of wastewater treatment in waste stabilization pond is based on the symbiotic relationship between bacteria and various algal species. In this study, an attempt was made to relate algal growth and different extrinsic factors using multiple regression models. The predominant algal species found in WSP systems were Chlorella, Euglena, Oscillatoria and Scenedesmus. The growth of individual algal species and overall algal growth was principally governed by temperature, total sunshine hours and Total Kjeldhal Nitrogen (TKN). The study suggested that algal bacterial symbiotic relationship works well and the dissolved oxygen production through algal photosynthesis was optimum to decompose heavy organic load resulting in oxygen-rich effluent (liquid fertilizer) which could be successfully exploited for unrestricted irrigation. (author)

  10. 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......, and the resulting dissolved CO2 concentration supported maximum algal growth rates without pH drift for algal densities up to 4 mg dry weight/L. Two-day toxicity tests with kerosene were performed with this new test design and compared with an open bottle test and with a closed bottle test with headspace. Exposure...... concentrations of the volatile fraction of kerosene decreased by 99% in the open test, by 77% in the closed flask test with headspace, and by 16% in the filled closed bottle test. Algal growth inhibition was observed at much lower additions of kerosene in the new test design because of the improved maintenance...

  11. 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.

  12. Daphnia fed algal food grown at elevated temperature have reduced fitness

    Directory of Open Access Journals (Sweden)

    Anna B. Sikora

    2014-05-01

    Full Text Available Lake water temperature is negatively correlated with fatty acids content and P:C ratio in green algae. Hence, elevated temperature may indirectly reduce the fitness of Daphnia due to induced decrease in algal food quality. The aim of this study was to test the hypotheses that quality of algal food decreases with increasing temperature of its culture and that large-bodied Daphnia are more vulnerable to the temperature-related deterioration of algal food quality than small-bodied ones. Laboratory life-table experiments were performed at 20°C with large-bodied D. pulicaria and small-bodied D. cucullata fed with the green alga Scenedesmus obliquus, that had been grown at temperatures of 16, 24 or 32°C. The somatic growth rates of both species decreased significantly with increasing algal culture temperature and this effect was more pronounced in D. pulicaria than in D. cucullata. In the former species, age at first reproduction significantly increased and clutch size significantly decreased with increasing temperature of algae growth, while no significant changes in these two parameters were observed in the latter species. The proportion of egg-bearing females decreased with increasing algal culture temperature in both species. The results of this study support the notion that the quality of algal food decreases with increasing water temperature and also suggest that small-bodied Daphnia species might be less vulnerable to temperature-related decreases in algal food quality than large-bodied ones.

  13. Evidence for water-mediated mechanisms in coral–algal interactions

    Science.gov (United States)

    Jorissen, Hendrikje; Skinner, Christina; Osinga, Ronald; de Beer, Dirk

    2016-01-01

    Although many coral reefs have shifted from coral-to-algal dominance, the consequence of such a transition for coral–algal interactions and their underlying mechanisms remain poorly understood. At the microscale, it is unclear how diffusive boundary layers (DBLs) and surface oxygen concentrations at the coral–algal interface vary with algal competitors and competitiveness. Using field observations and microsensor measurements in a flow chamber, we show that coral (massive Porites) interfaces with thick turf algae, macroalgae, and cyanobacteria, which are successful competitors against coral in the field, are characterized by a thick DBL and hypoxia at night. In contrast, coral interfaces with crustose coralline algae, conspecifics, and thin turf algae, which are poorer competitors, have a thin DBL and low hypoxia at night. Furthermore, DBL thickness and hypoxia at the interface with turf decreased with increasing flow speed, but not when thick turf was upstream. Our results support the importance of water-mediated transport mechanisms in coral–algal interactions. Shifts towards algal dominance, particularly dense assemblages, may lead to thicker DBLs, higher hypoxia, and higher concentrations of harmful metabolites and pathogens along coral borders, which in turn may facilitate algal overgrowth of live corals. These effects may be mediated by flow speed and orientation. PMID:27512146

  14. An integrated renewable energy park approach for algal biofuel production in United States

    Energy Technology Data Exchange (ETDEWEB)

    Subhadra, Bobban [Department of Internal Medicine, School of Medicine, University of New Mexico, Albuquerque, NM 87131 (United States); Edwards, Mark [Marketing and Sustainability, W.P. Carey School of Business, Arizona State University, Tempe, AZ 85282 (United States)

    2010-09-15

    Algal biomass provides viable third generation feedstock for liquid transportation fuel that does not compete with food crops for cropland. However, fossil energy inputs and intensive water usage diminishes the positive aspects of algal energy production. An integrated renewable energy park (IREP) approach is proposed for aligning renewable energy industries in resource-specific regions in United States for synergistic electricity and liquid biofuel production from algal biomass with net zero carbon emissions. The benefits, challenges and policy needs of this approach are discussed. (author)

  15. Algal Biomass Analysis by Laser-Based Analytical Techniques—A Review

    Directory of Open Access Journals (Sweden)

    Pavel Pořízka

    2014-09-01

    Full Text Available Algal biomass that is represented mainly by commercially grown algal strains has recently found many potential applications in various fields of interest. Its utilization has been found advantageous in the fields of bioremediation, biofuel production and the food industry. This paper reviews recent developments in the analysis of algal biomass with the main focus on the Laser-Induced Breakdown Spectroscopy, Raman spectroscopy, and partly Laser-Ablation Inductively Coupled Plasma techniques. The advantages of the selected laser-based analytical techniques are revealed and their fields of use are discussed in detail.

  16. An integrated renewable energy park approach for algal biofuel production in United States

    International Nuclear Information System (INIS)

    Subhadra, Bobban; Edwards, Mark

    2010-01-01

    Algal biomass provides viable third generation feedstock for liquid transportation fuel that does not compete with food crops for cropland. However, fossil energy inputs and intensive water usage diminishes the positive aspects of algal energy production. An integrated renewable energy park (IREP) approach is proposed for aligning renewable energy industries in resource-specific regions in United States for synergistic electricity and liquid biofuel production from algal biomass with net zero carbon emissions. The benefits, challenges and policy needs of this approach are discussed.

  17. Inhibition of the development of pathogenic fungi by extracts of some ...

    African Journals Online (AJOL)

    The different marine algae belonged to Chlorophyta (Enteromorpha prolifera and Ulva reticulata), Phaeophyta (Cystoseira myrica, Padina pavonica, Sargassum portieriatum and Turbinaria triquetra) and Rhodophyta (Gracilaria multipartita). Algal extraction was achieved successively by using petroleum ether, diethyl ether, ...

  18. Determination of Total Carbohydrates in Algal Biomass: Laboratory Analytical Procedure (LAP)

    Energy Technology Data Exchange (ETDEWEB)

    Van Wychen, Stefanie; Laurens, Lieve M. L.

    2016-01-13

    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.

  19. 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.

  20. THE TRPV1 RECEPTOR: THE INTERAGENCY, INTERNATION SYMPOSIUM ON CYANOBACTERIAL HARMFUL ALGAL BLOOMS.

    Science.gov (United States)

    Background and Significance Evidence indicates that the frequency of occurrence of cyanobacterial harmful algal blooms (CHABs) is increasing in spatial and temporal extent in the US and worldwide. Cyanotoxins are among the most potent toxins known, causing death through ...

  1. 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.

  2. The effect of algal and bacterial filters on sea water quality during ...

    African Journals Online (AJOL)

    quality changes in bacterial and algal filtration systems over a two month period. Juvenile ..... of the algae, prawns and micro-organisms (decomposition of excess food and .... Cultivation of marine organisms: Water quality management and ...

  3. effect of natural blue-green algal cells lysis on freshwater quality

    African Journals Online (AJOL)

    Compaq

    released into water due to algal cells lysis was performed by placing samples in two ... Keywords; Algae, cells lysis, Fatty acids, gas chromatography time-of-flight mass spectrometry, water quality ... Factors such as municipal and industrial.

  4. Characterisation of transparent exopolymer particles (TEP) produced during algal bloom: A membrane treatment perspective

    KAUST Repository

    Villacorte, Loreen O.; Ekowati, Yuli; Winters, Harvey; Amy, Gary L.; Schippers, Jan Cornelis; Kennedy, D.

    2013-01-01

    Algal blooms are currently a major concern of the membrane industry as it generates massive concentrations of organic matter (e.g. transparent exopolymer particles [TEP]), which can adversely affect the operation of membrane filtration systems

  5. Comparison of Acute Toxicity of Algal Metabolites Using Bioluminescence Inhibition Assay

    Directory of Open Access Journals (Sweden)

    Hansa Jeswani

    2015-01-01

    Full Text Available Microalgae are reported to degrade hazardous compounds. However, algae, especially cyanobacteria are known to produce secondary metabolites which may be toxic to flora, fauna and human beings. The aim of this study was selection of an appropriate algal culture for biological treatment of biomass gasification wastewater based on acute toxicity considerations. The three algae that were selected were Spirulina sp., Scenedesmus abundans and a fresh water algal consortium. Acute toxicity of the metabolites produced by these algal cultures was tested at the end of log phase using the standard bioluminescence inhibition assay based on Vibrio fischeri NRRLB 11174. Scenedesmus abundans and a fresh water algal consortium dominated by cyanobacteria such as Phormidium, Chroococcus and Oscillatoria did not release much toxic metabolites at the end of log phase and caused only about 20% inhibition in bioluminescence. In comparison, Spirulina sp. released toxic metabolites and caused 50% bioluminescence inhibition at 3/5 times dilution of the culture supernatant (EC50.

  6. 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.

  7. 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.

  8. Free ammonia offers algal crop protection from predators in dairy wastewater and ammonium-rich media.

    Science.gov (United States)

    Thomas, Patrick K; Dunn, Gary P; Passero, Maxine; Feris, Kevin P

    2017-11-01

    Cost-effective methods for protecting crops from grazing organisms like rotifers are needed to reduce the risk of pond crashes in mass algal cultures. We present a novel strategy to optimize the exposure time to free ammonia, via control of media pH, in both defined media and dairy anaerobic digester effluent to suppress rotifers and maintain algal productivity. We tested five different free ammonia exposure times (0, 1, 2, 6, and 12h) and found a significant nonlinear effect of exposure time (p0.9) on rotifer survival. In both media types, 6-12h of elevated free ammonia significantly reduced Brachionus plicatilis rotifer survival with no negative effects on Nannochloropsis oculata, while shorter exposure times were insufficient to inhibit rotifers, leading to severe algal culture crashes. These results suggest that algal crops can be protected from rotifers, without productivity loss, by elevating free ammonia for 6 or more hours. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Bio prospecting for High Lipid-producing Indigenous Algal in 8 South African provinces

    CSIR Research Space (South Africa)

    Ramukhwatho, R

    2011-10-01

    Full Text Available The scope of this project covers the screening and characterisation of selected indigenous algal strains and screening them for lipid production potential. The algae were isolated from salt- and freshwater bodies, along the Western Cape coastline...

  10. Algal-based immobilization process to treat the effluent from a secondary wastewater treatment plant (WWTP)

    International Nuclear Information System (INIS)

    He Shengbing; Xue Gang

    2010-01-01

    Algal-based immobilization process was applied to treat the effluent from a secondary wastewater treatment plant. Batch test proved that algae could attach onto fiber-bundle carrier in 7 days, and then the algal-based immobilization reactor could reduce TN (total nitrogen) and TP (total phosphorus) significantly within 48 h. Based on the above investigations, the hydraulic retention time (HRT) of the algal-based immobilization reactor in continuous operation mode was determined to be 2 days. During the 91 days of experiment on the treating secondary effluent of Guang-Rao wastewater treatment plant, it was found that the fiber-bundle carrier could collect the heterobacteria and nitrifying bacteria gradually, and thus improved the COD removal efficiency and nitrification performance step by step. Results of the continuous operation indicated that the final effluent could meet the Chinese National First A-level Sewage Discharge Standard when the algal-based immobilization reactor reached steady state.

  11. A Molecular Genetic Classification of Zooxanthellae and the Evolution of Animal-Algal Symbioses

    Science.gov (United States)

    Rowan, Rob; Powers, Dennis A.

    1991-03-01

    Zooxanthellae are unicellular algae that occur as endosymbionts in many hundreds of marine invertebrate species. Because zooxanthellae have traditionally been difficult to classify, little is known about the natural history of these symbioses. Zooxanthellae were isolated from 131 individuals in 22 host taxa and characterized by the use of restriction fragment length polymorphisms (RFLPs) in nuclear genes that encode small ribosomal subunit RNA (ssRNA). Six algal RFLPs, distributed host species specifically, were detected. Individual hosts contained one algal RFLP. Zooxanthella phylogenetic relationships were estimated from 22 algal ssRNA sequences-one from each host species. Closely related algae were found in dissimilar hosts, suggesting that animal and algal lineages have maintained a flexible evolutionary relation with each other.

  12. 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...

  13. Coeloseira compressa Hollenb. (Champiaceae, Rhodophyta) - a new marine algal species from Goa, India

    Digital Repository Service at National Institute of Oceanography (India)

    Deshmukhe, G.V.; Untawale, A.G.

    Occurrence of a red algal species Coeloseira is recorded from Bambolim coast, Goa along the central west coast of India. The genus is characterised by the presence of polysporangia, stoloniferous pattern branching, separate secondary branches and a...

  14. 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.

  15. 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.

  16. Stressor-Response Models Relating Nutrient Enrichment to Algal Communities in Pacific Northwest Streams and Rivers

    Science.gov (United States)

    Sobota, D. J.; Hubler, S.; Paul, M. J.; Labiosa, R.

    2015-12-01

    Excessive algal growth in streams and rivers from nutrient enrichment can cause costly human health and environmental problems. As part of the US Environmental Protection Agency's Nutrient Scientific Technical Exchange Partnership and Support (N-STEPS) program, we have been developing stressor-response (S-R) models relating nutrients to attached algal (periphyton) communities to help prioritize monitoring for water quality impairments in Oregon (Pacific Northwest, USA) streams and rivers. Existing data from the state and neighboring states were compiled and standardized from the Oregon Department of Environmental Quality, US Environmental Protection Agency, and the US Geological Survey. To develop S-R models, algal community and biomass metrics were compared with nitrogen (N) and phosphorus (P) concentration data, including total, dissolved, and inorganic forms of these nutrients. In total, 928 paired algal-nutrient samples were compiled from the 8 Level-III Ecoregions occurring in Oregon. Relationships between algal biomass metrics and nutrient concentrations were weak, with only ash-free dry mass and standing stock of chlorophyll a showing slight positive relationships across gradients of total N and soluble reactive P concentrations, respectively. In contrast, metrics describing algal community composition, including percent diatoms and abundance of nutrient-sensitive species, showed very strong nonlinear relationships with total N or P concentrations. This suggests that data describing algal community composition can help identify specific nutrient stressors across environmentally-diverse streams and rivers in the Pacific Northwest. Future analyses will examine if nutrient-algal S-R models vary across different hydrological, physiographical, and ecological settings in the region.

  17. Investigation and Control of Algal Grwoths in Water Resources Using Zn Oxide Nanoparticles

    Directory of Open Access Journals (Sweden)

    Mehdi Eskandary

    2016-03-01

    Full Text Available Increasing nutrients such as nitrates and phosphates in water resources lead to the growth of various algal species, causing undesirable odors and taste in the water. This study investigated the identification and removal of harmful algal growths by Zinc oxide nanoparticles (using Ardabil Yamichi Dam reservoir as a case study. Samples were initially collected from the Yamichi Dam reservoir and the algae in the water samples were cultivated. Enough time was allowed for the algae to grow before they were identified under the microscope. The results showed that most of the algal species grown in the culture medium belonged to the species Cladophora and Euglena. Zinc oxide nanoparticles were then synthesized to be used in the removal and/or inhibition of algal growths. ZnO nanoparticles were subsequently characterized by transmission electron microscopy (TEM and X-ray diffraction (XRD methods which revealed that the size of the ZnO nanoparticles was in the range of 10‒30 nanometers and further that the nanoparticles were pure and of a  hexagonal phase. In continuation, the capability of ZnO nanoparticles with concentrations in the range of 0-3 ppm to inhibit algal growth was investigated. Results showed that no reduction was observed in algal growth for Zinc oxide nanoparticle concentrations below 1 mg/lit. At concentrations between 1 to 2 mg/lit, however, a significant reduction was observed in algal growth. Finally, it was found that algal growths completely stopped at ZnO concentrations beyond 2 mg/lit

  18. Whole-lake algal responses to a century of acidic industrial deposition on the Canadian Shield

    International Nuclear Information System (INIS)

    Vinebrooke, R.D.; Dixit, S.S.; Graham, M.D.; Gunn, J.M.; Chen, Y.-W.; Belzile, N.

    2002-01-01

    A century of cultural acidification is hypothesized to have altered algal community structure in boreal lakes. To date, this hypothesis has remained untested because of both the lack of data predating the onset of industrial pollution and incomplete estimates of whole-lake algal community structure. High-pressure liquid chromatography (HPLC) of sedimentary pigments was used to quantify whole-lake algal responses to acid deposition in six boreal lakes located in Killarney Park, Ontario, Canada. Concomitant significant increases in chlorophyll and carotenoid concentrations, diatom-inferred lake acidity, and metal levels since 1900 suggested that algal abundances in four acidified lakes and one small, circumneutral lake were enhanced by aerial pollution. An alternate explanation is that increased acidity and underwater light availability in the acidified lakes shifted algal abundance towards phytobenthos and deepwater phytoplankton, whose pigment signatures were better preserved in the sediments. Taxonomically diagnostic pigment stratigraphies were consistent with shifts in algal community structure towards filamentous green phytobenthos and deepwater phytoflagellates in the acidified lakes. Our findings suggest that decades of aerial pollution have altered the base of foodwebs in boreal lakes, potentially rendering them less resilient to other environmental stressors. (author)

  19. Enhanced production of green tide algal biomass through additional carbon supply.

    Science.gov (United States)

    de Paula Silva, Pedro H; Paul, Nicholas A; de Nys, Rocky; Mata, Leonardo

    2013-01-01

    Intensive algal cultivation usually requires a high flux of dissolved inorganic carbon (Ci) to support productivity, particularly for high density algal cultures. Carbon dioxide (CO2) enrichment can be used to overcome Ci limitation and enhance productivity of algae in intensive culture, however, it is unclear whether algal species with the ability to utilise bicarbonate (HCO3 (-)) as a carbon source for photosynthesis will benefit from CO2 enrichment. This study quantified the HCO3 (-) affinity of three green tide algal species, Cladophora coelothrix, Cladophora patentiramea and Chaetomorpha linum, targeted for biomass and bioenergy production. Subsequently, we quantified productivity and carbon, nitrogen and ash content in response to CO2 enrichment. All three species had similar high pH compensation points (9.7-9.9), and grew at similar rates up to pH 9, demonstrating HCO3 (-) utilization. Algal cultures enriched with CO2 as a carbon source had 30% more total Ci available, supplying twenty five times more CO2 than the control. This higher Ci significantly enhanced the productivity of Cladophora coelothrix (26%), Chaetomorpha linum (24%) and to a lesser extent for Cladophora patentiramea (11%), compared to controls. We demonstrated that supplying carbon as CO2 can enhance the productivity of targeted green tide algal species under intensive culture, despite their clear ability to utilise HCO3 (-).

  20. Enhanced production of green tide algal biomass through additional carbon supply.

    Directory of Open Access Journals (Sweden)

    Pedro H de Paula Silva

    Full Text Available Intensive algal cultivation usually requires a high flux of dissolved inorganic carbon (Ci to support productivity, particularly for high density algal cultures. Carbon dioxide (CO2 enrichment can be used to overcome Ci limitation and enhance productivity of algae in intensive culture, however, it is unclear whether algal species with the ability to utilise bicarbonate (HCO3 (- as a carbon source for photosynthesis will benefit from CO2 enrichment. This study quantified the HCO3 (- affinity of three green tide algal species, Cladophora coelothrix, Cladophora patentiramea and Chaetomorpha linum, targeted for biomass and bioenergy production. Subsequently, we quantified productivity and carbon, nitrogen and ash content in response to CO2 enrichment. All three species had similar high pH compensation points (9.7-9.9, and grew at similar rates up to pH 9, demonstrating HCO3 (- utilization. Algal cultures enriched with CO2 as a carbon source had 30% more total Ci available, supplying twenty five times more CO2 than the control. This higher Ci significantly enhanced the productivity of Cladophora coelothrix (26%, Chaetomorpha linum (24% and to a lesser extent for Cladophora patentiramea (11%, compared to controls. We demonstrated that supplying carbon as CO2 can enhance the productivity of targeted green tide algal species under intensive culture, despite their clear ability to utilise HCO3 (-.

  1. Review of the algal biology program within the National Alliance for Advanced Biofuels and Bioproducts

    Energy Technology Data Exchange (ETDEWEB)

    Unkefer, Clifford J.; Sayre, Richard T.; Magnuson, Jon K.; Anderson, Daniel B.; Baxter, Ivan; Blaby, Ian K.; Brown, Judith K.; Carleton, Michael; Cattolico, Rose Ann; Dale, Taraka; Devarenne, Timothy P.; Downes, C. Meghan; Dutcher, Susan K.; Fox, David T.; Goodenough, Ursula; Jaworski, Jan; Holladay, Jonathan E.; Kramer, David M.; Koppisch, Andrew T.; Lipton, Mary S.; Marrone, Babetta L.; McCormick, Margaret; Molnár, István; Mott, John B.; Ogden, Kimberly L.; Panisko, Ellen A.; Pellegrini, Matteo; Polle, Juergen; Richardson, James W.; Sabarsky, Martin; Starkenburg, Shawn R.; Stormo, Gary D.; Teshima, Munehiro; Twary, Scott N.; Unkefer, Pat J.; Yuan, Joshua S.; Olivares, José A.

    2017-03-01

    In 2010,when the National Alliance for Advanced Biofuels and Bioproducts (NAABB) consortiumbegan, littlewas known about themolecular basis of algal biomass or oil production. Very fewalgal genome sequenceswere available and efforts to identify the best-producing wild species through bioprospecting approaches had largely stalled after the U.S. Department of Energy's Aquatic Species Program. This lack of knowledge included how reduced carbon was partitioned into storage products like triglycerides or starch and the role played bymetabolite remodeling in the accumulation of energy-dense storage products. Furthermore, genetic transformation and metabolic engineering approaches to improve algal biomass and oil yields were in their infancy. Genome sequencing and transcriptional profiling were becoming less expensive, however; and the tools to annotate gene expression profiles under various growth and engineered conditions were just starting to be developed for algae. It was in this context that an integrated algal biology program was introduced in the NAABB to address the greatest constraints limiting algal biomass yield. This review describes the NAABB algal biology program, including hypotheses, research objectives, and strategies to move algal biology research into the twenty-first century and to realize the greatest potential of algae biomass systems to produce biofuels.

  2. Strategies for Optimizing Algal Biology for Enhanced Biomass Production

    Energy Technology Data Exchange (ETDEWEB)

    Barry, Amanda N.; Starkenburg, Shawn R.; Sayre, Richard T., E-mail: rsayre@newmexicoconsortium.org [Los Alamos National Laboratory, New Mexico Consortium, Los Alamos, NM (United States)

    2015-02-02

    One of the most 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 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 twofold increases in biomass productivity.

  3. [Algal control ability of allelopathically active submerged macrophytes: a review].

    Science.gov (United States)

    Xiao, Xi; Lou, Li-ping; Li, Hua; Chen, Ying-xu

    2009-03-01

    The inhibitory effect of allelochemicals released by submerged macrophytes on phytoplankton is considered as one of the mechanisms that contribute to the stabilization of clear-water status in shallow lakes. This paper reviewed the research progress in the allelopathy of submerged macrophytes on algae from the aspects of the occurrence frequency and coverage of allelopathically active submerged macrophytes in lakes, and the kinds and allelopathical effects of the allelochemicals released from the macrophytes. The previous researches indicated that allelopathically active submerged macrophyte species such as Myriophyllum, Ceratophyllum, and Elodea were efficient to control phytoplankton, especially when their biomass was high enough, and the dominant algae were sensitive species. The allelochemicals such as hydroxybenzene released by the submerged macrophytes could inhibit the growth of algae. Different phytoplankton species exhibited different sensitivity against allelochemicals, e.g., cyanobacteria and diatom were more sensitive than green algae, while epiphytic species were less sensitive than phytoplankton. Environmental factors such as light, temperature, and nutrients could significantly affect the allelopathical effect of submerged macrophytes. The research of the allelopathy of submerged macrophytes is still at its beginning, and further researches are needed on the effects of environmental factors on the allelopathy, extraction and identification of allelochemicals, selective algal control mechanisms, and metabolism of the allelochmicals.

  4. Strategies for Optimizing Algal Biology for Enhanced Biomass Production

    International Nuclear Information System (INIS)

    Barry, Amanda N.; Starkenburg, Shawn R.; Sayre, Richard T.

    2015-01-01

    One of the most 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 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 twofold increases in biomass productivity.

  5. 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.

  6. Inhibition of marine algal photosynthesis by heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Overnell, J.

    1976-12-03

    A total of ninety phytoplankton species was recorded from June 1972 to May 1973 in samples taken weekly at Seal Beach, California. The study area was located in the vicinity of the mouth of the San Gabriel River, which is used as a site of discharge for heated effluents by two electric power plants and as a flood control channel by Los Angeles County. On a yearly basis, the two dominant algal groups were diatoms (forty-six species) and dinoflagellates (thirty-six species), accounting respectively for 64 percent and 30 percent of the total cell number, and for 20 percent and 79 percent of the total cell volume. The average phytoplankton concentration throughout the year was 180,000 cells l/sup -1/. A dinoflagellate bloom was observed in August between the two major peaks of diatoms which occurred during June--July and in late September. The five most common species (in order), Rhizosolenia delicatula, Chaetoceros curvisetus, Prorocentrum micans, Ceratium furca and Gymnodinium simplex, were present in more than 50 percent of the samples. The species diversity index (H') remained relatively stable during the year, showing no distinct seasonal pattern. Three interconnected associations of species were distinguished by x/sup 2/ analysis. The major group, composed mainly of dinoflagellates, was correlated with warm water conditions at Seal Beach. The other groups occurred at various times during the year, irrespective of seasonal variations, suggesting a possible mutualistic relationship between the species involved.

  7. 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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Aerosol Emissions from Great Lakes Harmful Algal Blooms

    Energy Technology Data Exchange (ETDEWEB)

    May, Nathaniel W. [Department; Olson, Nicole E. [Department; Panas, Mark [Department; Axson, Jessica L. [Department; Tirella, Peter S. [Department; Kirpes, Rachel M. [Department; Craig, Rebecca L. [Department; Gunsch, Matthew J. [Department; China, Swarup [William; Laskin, Alexander [William; Ault, Andrew P. [Department; Department; Pratt, Kerri A. [Department; Department

    2017-12-20

    In freshwater lakes, harmful algal blooms (HABs) of Cyanobacteria (blue-green algae) produce toxins that impact human health. However, little is known about the chemical species present in lake spray aerosol (LSA) produced from wave-breaking in freshwater HABs. In this study, a laboratory LSA generator produced aerosols from freshwater samples collected from Lake Michigan and Lake Erie during HAB and non-bloom conditions. Particles were analyzed for size and chemical composition by single particle mass spectrometry, electron microscopy, and fluorescence microscopy, with three distinct types of LSA identified with varying levels of organic carbon and biological material associated with calcium salts. LSA autofluorescence increases with blue-green algae concentration, showing that organic molecules of biological origin are incorporated in LSA from HABs. The number fraction of LSA with biological mass spectral markers also increases with particle diameter (greater than 0.5 μm), showing that HABs have size-dependent impacts on aerosol composition. The highest number fraction of LSA enriched in organic carbon were observed in particles less than 0.5 μm in diameter. Understanding the transfer of organic and biogenic material from freshwater to the atmosphere via LSA particles is crucial for determining health and climate effects due to HABs.

  9. Algal ancestor of land plants was preadapted for symbiosis.

    Science.gov (United States)

    Delaux, Pierre-Marc; Radhakrishnan, Guru V; Jayaraman, Dhileepkumar; Cheema, Jitender; Malbreil, Mathilde; Volkening, Jeremy D; Sekimoto, Hiroyuki; Nishiyama, Tomoaki; Melkonian, Michael; Pokorny, Lisa; Rothfels, Carl J; Sederoff, Heike Winter; Stevenson, Dennis W; Surek, Barbara; Zhang, Yong; Sussman, Michael R; Dunand, Christophe; Morris, Richard J; Roux, Christophe; Wong, Gane Ka-Shu; Oldroyd, Giles E D; Ané, Jean-Michel

    2015-10-27

    Colonization of land by plants was a major transition on Earth, but the developmental and genetic innovations required for this transition remain unknown. Physiological studies and the fossil record strongly suggest that the ability of the first land plants to form symbiotic associations with beneficial fungi was one of these critical innovations. In angiosperms, genes required for the perception and transduction of diffusible fungal signals for root colonization and for nutrient exchange have been characterized. However, the origin of these genes and their potential correlation with land colonization remain elusive. A comprehensive phylogenetic analysis of 259 transcriptomes and 10 green algal and basal land plant genomes, coupled with the characterization of the evolutionary path leading to the appearance of a key regulator, a calcium- and calmodulin-dependent protein kinase, showed that the symbiotic signaling pathway predated the first land plants. In contrast, downstream genes required for root colonization and their specific expression pattern probably appeared subsequent to the colonization of land. We conclude that the most recent common ancestor of extant land plants and green algae was preadapted for symbiotic associations. Subsequent improvement of this precursor stage in early land plants through rounds of gene duplication led to the acquisition of additional pathways and the ability to form a fully functional arbuscular mycorrhizal symbiosis.

  10. The Mechanisms of Adhesion of Enteromorpha Clathrata.

    Science.gov (United States)

    1982-08-24

    extracellular polymer was responsible for adhesion to a substrate (21,23,26,39,40,42,59,62,63,74,78, 86,91). The adhesion of Chlorella vulgaris may also depend...marine Chlorella vulgaris to glass. Can. J. Microbiol. 21:1025-1031. 88. Van Baalen, C., 1962. Studies on marine blue-green .4 algae. Bot. Mar. 4:129...also been observed with the unicellular green alga, Chlorella (68). Other negatively charged groups that could be present are phosphatidic groups (46

  11. Zoosporic fungal parasites of marine biota

    Digital Repository Service at National Institute of Oceanography (India)

    RaghuKumar, C.

    laboratory media. In such instances, a detailed and careful examination of the disease symptoms and the endobiotic fungal parasites is to be recorded. Maintaining dual culture of the healthy and infected host also helps to fulfill these postulates partially....

  12. Responses of Algal Cells to Engineered Nanoparticles Measured as Algal Cell Population, Chlorophyll a, and Lipid Peroxidation: Effect of Particle Size and Type

    Directory of Open Access Journals (Sweden)

    D. M. Metzler

    2012-01-01

    Full Text Available This paper investigated toxicity of three engineered nanoparticles (ENP, namely, Al2O3, SiO2, and TiO2 to the unicellular green algae, exemplified by Pseudokirchneriella subcapitata with an emphasis on particle size. The changes in pH, cell counts, chlorophyll a, and lipid peroxidation were used to measure the responses of the algal species to ENP. The most toxic particle size was TiO2 at 42 nm with an EC20 of 5.2 mg/L and Al2O3 at 14–18 nm with an EC20 of 5.1 mg/L. SiO2 was the least toxic with an EC20 of 318 mg/L. Toxicity was positively related to the surface charge of both ENP and algae. The chlorophyll content of the algal cells was influenced by the presence of ENP, which resulted in limited light and availability of nutrients due to increase in turbidity and nutrient adsorption onto the ENP surface, separately. Lipid peroxidation was attributed to reactive oxygen species (ROS. Fast reaction between algal cells and ROS due to direct contact between TiO2 and algal cells is an important factor for lipid peroxidation.

  13. Recent Inventions and Trends in Algal Biofuels Research.

    Science.gov (United States)

    Karemore, Ankush; Nayak, Manoranjan; Sen, Ramkrishna

    2016-01-01

    In recent times, when energy crisis compounded by global warming and climate change is receiving worldwide attention, the emergence of algae, as a better feedstock for third-generation biofuels than energy crops or plants, holds great promise. As compared to conventional biofuels feedstocks, algae offer several advantages and can alone produce a significant amount of biofuels sustainably in a shorter period to fulfill the rising demand for energy. Towards commercialisation, there have been numerous efforts put for- ward for the development of algae-derived biofuel. This article reviews and summarizes the recent inventions and the current trends that are reported and captured in relevant patents pertaining to the novel methods of algae biomass cultivation and processing for biofuels and value-added products. In addition, the recent advancement in techniques and technologies for microalgal biofuel production has been highlighted. Various steps involved in the production of algal biofuels have been considered in this article. Moreover, the work that advances to improve the efficiency and cost-effectiveness of the processes for the manufacture of biofuels has been presented. Our survey was conducted in the patent databases: WIPO, Spacenet and USPTO. There are still some technological bottlenecks that could be overcome by designing advanced photobioreactor and raceway ponds, developing new and low cost technologies for biomass cultivation, harvesting, drying and extraction. Recent advancement in algae biofuels methods is directed toward developing efficient and integrated systems to produce biofuels by overcoming the current challenges. However, further research effort is required to scale-up and improve the efficiency of these methods in the upstream and downstream technologies to make the cost of biofuels competitive with petroleum fuels.

  14. Sewage, green algal mats anchored by lugworms, and the effects on Turbellaria and small Polychaeta

    Science.gov (United States)

    Reise, Karsten

    1983-06-01

    On sandy tidal flats at the Island of Sylt (North Sea) ephemeral mats of green algae covered wide areas in the vicinity of sewage outflows. Algae became anchored in the feeding funnels of lugworms ( Arenicola marina) and thus were able to resist displacement by tidal currents. Below the algal mats anoxic conditions extend to the sediment surface. After about one month a rough sea removed all algae. Polychaetes endured this short-term environmental deterioration, while the more sensitive Turbellaria decreased in abundance and species richness. Diatom-feeders were affected most, predators to a medium extent, and bacteria-feeders the least affected. Rare and very abundant species were more affected than moderately abundant ones. None of the turbellarian species increased in abundance and none colonized the algal mats above the sediment. In a semicontrolled experiment with daily hand-removal of drift algae from a 100-m2 plot within an extensive field of algal mats, this cleaned "island" served as a refuge to Turbellaria escaping from their algal covered habitat. Here abundance doubled relative to initial conditions and was 5-times higher than below algal mats.

  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. 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, and ......, ecosystem quality, and resources were higher than the conventional diesel. This study recommends more practical data at pilot-scale production plant with maximum utilization of by-products generated during the production to produce a sustainable algal biodiesel......., and centrifugation, and two different oil extraction methods, i.e., supercritical CO2 (sCO2) and press and co-solvent extraction). The cultivation of Nannochloropsis sp. considered in a flat-panel photobioreactor (FPPBR). These algal biodiesel production systems were compared with the conventional diesel in a EURO 5...... passenger car used for transport purpose (functional unit 1 person km (pkm). The algal biodiesel production systems provide lesser impact (22–105 %) in comparison with conventional diesel. Impacts of algal biodiesel on climate change were far better than conventional diesel, but impacts on human health...

  17. Addressing harmful algal blooms (HABs) impacts with ferrate(VI): Simultaneous removal of algal cells and toxins for drinking water treatment.

    Science.gov (United States)

    Deng, Yang; Wu, Meiyin; Zhang, Huiqin; Zheng, Lei; Acosta, Yaritza; Hsu, Tsung-Ta D

    2017-11-01

    Although ferrate(VI) has long been recognized as a multi-purpose treatment agent, previous investigations regarding ferrate(VI) for addressing harmful algal blooms (HABs) impacts in drinking water treatment only focused on a single HAB pollutant (e.g. algal cells or algal toxins). Moreover, the performance of ferrate(VI)-driven coagulation was poorly investigated in comparison with ferrate(VI) oxidation, though it has been widely acknowledged as a major ferrate(VI) treatment mechanism. We herein reported ferrate(VI) as an emerging agent for simultaneous and effective removal of algal cells and toxins in a simulated HAB-impacted water. Ferrate(VI)-driven oxidation enabled algal cell inactivation and toxin decomposition. Subsequently, Fe(III) from ferrate(VI) reduction initiated an in-situ coagulation for cell aggregation. Cell viability (initial 4.26 × 10 4 cells/mL at pH 5.5 and 5.16 × 10 4 cells/mL at pH 7.5) decreased to 0.0% at ≥ 7 mg/L Fe(VI) at pH 5.5 and 7.5, respectively. Cell density and turbidity were dramatically decreased at pH 5.5 once ferrate(VI) doses were beyond their respective threshold levels, which are defined as minimum effective iron doses (MEIDs). However, the particulate removal at pH 7.5 was poor, likely because the coagulation was principally driven by charge neutralization and a higher pH could not sufficiently lower the particle surface charge. Meanwhile, algal toxins (i.e., microcystins) of 3.98 μg/L could be substantially decomposed at either pH. And the greater degradation achieved at pH 5.5 was due to the higher reactivity of ferrate(VI) at the lower pH. This study represents the first step toward the ferrate(VI) application as a promising approach for addressing multiple HABs impacts for water treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Chemical composition influence of cement based mortars on algal biofouling

    Science.gov (United States)

    Estelle, Dalod; Alexandre, Govin; Philippe, Grosseau; Christine, Lors; René, Guyonnet; Denis, Damidot

    2013-04-01

    are easily distinguished. A threshold in graylevel allows to segment the image and to quantify the surface colonized by algae. The conversion process differentiates algal patches from dark slots caused by the rough relief. The covering rate depending on time is given by the ratio of colonized area to total surface. This experimental method proves that pH and roughness are determining in the biofouling mechanism.

  19. Characterized hydrochar of algal biomass for producing solid fuel through hydrothermal carbonization.

    Science.gov (United States)

    Park, Ki Young; Lee, Kwanyong; Kim, Daegi

    2018-06-01

    The aim of this work was to study the characterized hydrochar of algal biomass to produce solid fuel though hydrothermal carbonization. Hydrothermal carbonization conducted at temperatures ranging from 180 to 270 °C with a 60 min reaction improved the upgrading of the fuel properties and the dewatering of wet-basis biomasses such as algae. The carbon content, carbon recovery, energy recovery, and atomic C/O and C/H ratios in all the hydrochars in this study were improved. These characteristic changes in hydrochar from algal biomass are similar to the coalification reactions due to dehydration and decarboxylation with an increase in the hydrothermal reaction temperature. The results of this study indicate that hydrothermal carbonization can be used as an effective means of generating highly energy-efficient renewable fuel resources using algal biomass. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Productivity and species composition of algal mat communities exposed to a fluctuating thermal regime

    International Nuclear Information System (INIS)

    Tison, D.L.; Wilde, E.W.; Pope, D.H.; Fliermans, C.B.

    1981-01-01

    Algal mat communities growing in thermal effluents of production nuclear reactors at the Savannah River Plant, near Aiken, SC, are exposed to large temperature fluctuations resulting from reactor operations. Rates of primary production and species composition were monitored at 4 sites along a thermal gradient in a trough microcosm to determine how these large temperature fluctuations affected productivity and algal community structure. Blue-green algae (cyanobacteria) were the only phototrophic primary producers growing in water above 45 0 C. These thermophiles were able to survive and apparently adapt to ambient temperatures when the reactor was shut down. The algal mat communities exposed to 14 C-labeled dissolved organic compounds and a decrease in primary production were observed during periods of thermal fluctuation. The results show that the dominant phototrophs in this artificially heated aquatic habitat have been selected for their abiity to survive large temperature fluctuations and are similar to those of natural hot springs

  1. Algal testing of titanium dioxide nanoparticles - Testing considerations, inhibitory effects and modification of cadmium bioavailability

    DEFF Research Database (Denmark)

    Hartmann, Nanna Isabella Bloch; von der Kammer, F.; Hofmann, T.

    2010-01-01

    The ecotoxicity of three different sizes of titanium dioxide (TiO(2)) particles (primary particles sizes: 10, 30, and 300 nm) to the freshwater green alga Pseudokirchneriella subcapitata was investigated in this study. Algal growth inhibition was found for all three particle types...... surfaces. It is also believed that heteroaggregation, driven by algal exopolymeric exudates, is occurring and could influence the concentration-response relationship. The ecotoxicity of cadmium to algae was investigated both in the presence and absence of 2 mg/LTiO(2). The presence of TiO(2) in algal tests......(II) species, indicating a possible carrier effect, or combined toxic effect of TiO(2) nanoparticles and cadmium. These results emphasize the importance of systematic studies of nanoecotoxicological effects of different sizes of nanoparticles and underline the fact that, in addition to particle toxicity...

  2. An energy evaluation of coupling nutrient removal from wastewater with algal biomass production

    International Nuclear Information System (INIS)

    Sturm, Belinda S.M.; Lamer, Stacey L.

    2011-01-01

    Recently, several life cycle analyses of algal biodiesel from virtual production facilities have outlined the potential environmental benefits and energetic balance of the process. There are a wide range of assumptions that have been utilized for these calculations, including the addition of fertilizers and carbon dioxide to achieve high algal yields in open ponds. This paper presents an energy balance of microalgal production in open ponds coupled with nutrient removal from wastewater. Actual microalgal yields and nutrient removal rates were obtained from four pilot-scale reactors (2500 gallons each) fed with wastewater effluent from a conventional activated sludge process for 6 months, and the data was used to estimate an energy balance for treating the total average 12 million gallons per day processed by the wastewater treatment plant. Since one of the most energy-intensive steps is the dewatering of algal cultures, several thickening and dewatering processes were compared. This analysis also includes the energy offset from removing nutrients with algal reactors rather than the biological nutrient removal processes typically utilized in municipal wastewater treatment. The results show that biofuel production is energetically favorable for open pond reactors utilizing wastewater as a nutrient source, even without an energy credit for nutrient removal. The energy content of algal biomass was also considered as an alternate to lipid extraction and biodiesel production. Direct combustion of algal biomass may be a more viable energy source than biofuel production, especially when the lipid content of dry biomass (10% in this field experiment) is lower than the high values reported in lab-scale reactors (50-60%).

  3. The Hawaiian Freshwater Algal Database (HfwADB: a laboratory LIMS and online biodiversity resource

    Directory of Open Access Journals (Sweden)

    Sherwood Alison R

    2012-10-01

    Full Text Available Abstract Background Biodiversity databases serve the important role of highlighting species-level diversity from defined geographical regions. Databases that are specially designed to accommodate the types of data gathered during regional surveys are valuable in allowing full data access and display to researchers not directly involved with the project, while serving as a Laboratory Information Management System (LIMS. The Hawaiian Freshwater Algal Database, or HfwADB, was modified from the Hawaiian Algal Database to showcase non-marine algal specimens collected from the Hawaiian Archipelago by accommodating the additional level of organization required for samples including multiple species. Description The Hawaiian Freshwater Algal Database is a comprehensive and searchable database containing photographs and micrographs of samples and collection sites, geo-referenced collecting information, taxonomic data and standardized DNA sequence data. All data for individual samples are linked through unique 10-digit accession numbers (“Isolate Accession”, the first five of which correspond to the collection site (“Environmental Accession”. Users can search online for sample information by accession number, various levels of taxonomy, habitat or collection site. HfwADB is hosted at the University of Hawaii, and was made publicly accessible in October 2011. At the present time the database houses data for over 2,825 samples of non-marine algae from 1,786 collection sites from the Hawaiian Archipelago. These samples include cyanobacteria, red and green algae and diatoms, as well as lesser representation from some other algal lineages. Conclusions HfwADB is a digital repository that acts as a Laboratory Information Management System for Hawaiian non-marine algal data. Users can interact with the repository through the web to view relevant habitat data (including geo-referenced collection locations and download images of collection sites, specimen

  4. 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.

  5. 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.

  6. 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.

  7. The engine of the reef: photobiology of the coral–algal symbiosis

    Science.gov (United States)

    Roth, Melissa S.

    2014-01-01

    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. PMID:25202301

  8. 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...

  9. Alginate and Algal-Based Beads for the Sorption of Metal Cations: Cu(II and Pb(II

    Directory of Open Access Journals (Sweden)

    Shengye Wang

    2016-09-01

    Full Text Available 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.

  10. 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.

  11. Response of algal metrics to nutrients and physical factors and identification of nutrient thresholds in agricultural streams

    Science.gov (United States)

    Black, R.W.; Moran, P.W.; Frankforter, J.D.

    2011-01-01

    Many streams within the United States are impaired due to nutrient enrichment, particularly in agricultural settings. The present study examines the response of benthic algal communities in agricultural and minimally disturbed sites from across the western United States to a suite of environmental factors, including nutrients, collected at multiple scales. The first objective was to identify the relative importance of nutrients, habitat and watershed features, and macroinvertebrate trophic structure to explain algal metrics derived from deposition and erosion habitats. The second objective was to determine if thresholds in total nitrogen (TN) and total phosphorus (TP) related to algal metrics could be identified and how these thresholds varied across metrics and habitats. Nutrient concentrations within the agricultural areas were elevated and greater than published threshold values. All algal metrics examined responded to nutrients as hypothesized. Although nutrients typically were the most important variables in explaining the variation in each of the algal metrics, environmental factors operating at multiple scales also were important. Calculated thresholds for TN or TP based on the algal metrics generated from samples collected from erosion and deposition habitats were not significantly different. Little variability in threshold values for each metric for TN and TP was observed. The consistency of the threshold values measured across multiple metrics and habitats suggest that the thresholds identified in this study are ecologically relevant. Additional work to characterize the relationship between algal metrics, physical and chemical features, and nuisance algal growth would be of benefit to the development of nutrient thresholds and criteria. ?? 2010 The Author(s).

  12. 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.

  13. 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).

  14. Nitrogen recycling from fuel-extracted algal biomass: residuals as the sole nitrogen source for culturing Scenedesmus acutus.

    Science.gov (United States)

    Gu, Huiya; Nagle, Nick; Pienkos, Philip T; Posewitz, Matthew C

    2015-05-01

    In this study, the reuse of nitrogen from fuel-extracted algal residues was investigated. The alga Scenedesmus acutus was found to be able to assimilate nitrogen contained in amino acids, yeast extracts, and proteinaceous alga residuals. Moreover, these alternative nitrogen resources could replace nitrate in culturing media. The ability of S. acutus to utilize the nitrogen remaining in processed algal biomass was unique among the promising biofuel strains tested. This alga was leveraged in a recycling approach where nitrogen is recovered from algal biomass residuals that remain after lipids are extracted and carbohydrates are fermented to ethanol. The protein-rich residuals not only provided an effective nitrogen resource, but also contributed to a carbon "heterotrophic boost" in subsequent culturing, improving overall biomass and lipid yields relative to the control medium with only nitrate. Prior treatment of the algal residues with Diaion HP20 resin was required to remove compounds inhibitory to algal growth. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Barrancaceae: A new green algal lineage with structural and behavioral adaptations to a fluctuating environment.

    Science.gov (United States)

    Caisová, Lenka; Reyes, Carolina Pérez; Álamo, Virginia Cruz; Quintana, Antera Martel; Surek, Barbara; Melkonian, Michael

    2015-09-01

    To enhance our knowledge of the diversity of microalgae, a phycological survey of the Canary Islands (Spain) was undertaken. Here we report the discovery of a (semi)terrestrial green filamentous alga isolated from a steep volcanic canyon on La Palma. This alga is continually exposed to changing weather conditions (floods vs. droughts) and thus provides a good opportunity to investigate possible adaptations to a semiterrestrial habitat with large fluctuations of environmental parameters. We used axenic cultures, simulated flood and drought stresses and studied their effect on the life history of the alga using light, confocal laser scanning and scanning electron microscopy including fluorescent staining. Furthermore, phylogenetic analyses using rDNA sequence comparisons were performed. Three specific life-history traits that likely represent adaptations to the fluctuating environment of the canyon were observed: (1) fragmentation through "filament splitting", a unique branching mechanism not reported before in algae and initiated by formation of oblique cross walls, (2) aplanospore formation, and (3) reproduction by multiflagellate zoospores with 4-24 flagella arranged in groups of four. Phylogenetic analyses identified the alga as Barranca multiflagellata gen. et sp. nov. (Barrancaceae fam. nov., Chaetophorales, Chlorophyceae). Moreover, the Chaetophoraceae Greville, 1824 was emended and a new family, Uronemataceae (fam. nov.) erected. The discovery of Barrancaceae fam. nov. highlights the importance of investigating nonconventional habitats to explore microalgal diversity. The reproductive versatility demonstrated by Barranca suggests adaptation to a semiterrestrial habitat with large fluctuations in water availability. © 2015 Botanical Society of America.

  16. 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

  17. Design of a novel flat-plate photobioreactor system for green algal hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Tamburic, B.; Zemichael, F.W.; Maitland, G.C.; Hellgardt, K. [Imperial College London (United Kingdom)

    2010-07-01

    Some unicellular green algae have the ability to photosynthetically produce molecular hydrogen using sunlight and water. This renewable, carbon-neutral process has the additional benefit of sequestering carbon dioxide during the algal growth phase. The main costs associated with this process result from building and operating a photobioreactor system. The challenge is to design an innovative and cost effective photobioreactor that meets the requirements of algal growth and sustainable hydrogen production. We document the details of a novel 1 litre vertical flat-plate photobioreactor that has been designed to accommodate green algal hydrogen production at the laboratory scale. Coherent, non-heating illumination is provided by a panel of cool white LEDs. The reactor body consists of two compartments constructed from transparent Perspex sheets. The primary compartment holds the algal culture, which is agitated by means of a recirculating gas flow. A secondary compartment is filled with water and used to control the temperature and wavelength of the system. The reactor is fitted with instruments that monitor the pH, pO{sub 2}, temperature and optical density of the culture. A membrane-inlet mass spectrometry system has been developed for hydrogen collection and in situ monitoring. The reactor is fully autoclaveable and the possibility of hydrogen leaks has been minimised. The modular nature of the reactor allows efficient cleaning and maintenance. (orig.)

  18. 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.

  19. Biomanipulation with quagga mussels (Dreissena rostriformis bugensis) to control harmful algal blooms in eutrophic urban ponds

    NARCIS (Netherlands)

    Waajen, Guido W.A.M.; Bruggen, Van Niek C.B.; Pires, Miguel Dionisio L.; Lengkeek, Wouter; Lurling, Miguel

    2016-01-01

    Many urban ponds in The Netherlands and other countries suffer from eutrophication, resulting in harmful algal blooms which are often dominated by cyanobacteria. A sufficient reduction of nutrients, as prerequisite to mitigate cyanobacterial blooms in urban ponds, is not always feasible. Water

  20. Significance of Algal Assemblages in Assessing Water Quality of the River Nile at Minia,Egypt

    International Nuclear Information System (INIS)

    El-Shahed, A.M.; Ibrahim, H.A.

    1999-01-01

    A sector of the Nile system in the Providence Minia, has been studied for physicochemical properties of waters and characteristics of the inhabiting algal communities. Monthly samples in the period April, 1994-Marsh, 1995 were collected from three sites on the Nile and one site on a drainage canal connected to it. Samples were analysed for water temperature, ph, inorganic forms of nitrogen, inorganic phosphates, silicates, chemical oxygen demand, total carbohydrates, total proteins, and the major nutritive metal ions; Na +, K +, Ca + + a nd Mg + + . Algal samples, collected at the same intervals, were studied for the characteristics of algal communities including diversity of species, abundance of populations and species co,position. A total of 124 taxa were recorded during the period of study of which 27 cyanophytes, 34 chlorophyte, 6 euglenophytes and 57 bacillariophytes. Changes in water chemistry of the river Nile, on receiving discharges from domestic, agricultural and industrial effluents, have been shown to be accompanied with alterations in the algal communities including species composition, species diversity and abundance of populations. Water quality was assessed on the basis of both chemical and biological data and results have indicated that the Nile at the area of study is subjected to eutrophication and organic pollution. Bio indicator species have also used to distinguish polluted and relatively clean localities

  1. Suspended organic particles drive the development of attached algal communities in degraded peatlands

    NARCIS (Netherlands)

    Goldenberg Vilar, Alejandra; Vonk, J. Arie; van der geest, Harm; van Dam, Herman; Bichebois, Simon; Admiraal, Wim

    2014-01-01

    Mineral particles in rivers have been shown to cover adnate algal species, promoting motile and filamentous species. Such effects and the role of detrital particles have not been studied in stagnant waters. In degraded peat lands, detrital particles are very prominent and therefore we studied the

  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

  3. A qualitative reasoning model of algal bloom in the Danube Delta Biosphere Reserve (DDBR)

    NARCIS (Netherlands)

    Cioaca, E.; Linnebank, F.E.; Bredeweg, B.; Salles, P.

    2009-01-01

    This paper presents a Qualitative Reasoning model of the algal bloom phenomenon and its effects in the Danube Delta Biosphere Reserve (DDBR) in Romania. Qualitative Reasoning models represent processes and their cause-effect relationships in a flexible and conceptually rich manner and as such can be

  4. 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.

    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

  5. Industrial-strength ecology: trade-offs and opportunities in algal biofuel production.

    Science.gov (United States)

    Shurin, Jonathan B; Abbott, Rachel L; Deal, Michael S; Kwan, Garfield T; Litchman, Elena; McBride, Robert C; Mandal, Shovon; Smith, Val H

    2013-11-01

    Microalgae represent one of the most promising groups of candidate organisms for replacing fossil fuels with contemporary primary production as a renewable source of energy. Algae can produce many times more biomass per unit area than terrestrial crop plants, easing the competing demands for land with food crops and native ecosystems. However, several aspects of algal biology present unique challenges to the industrial-scale aquaculture of photosynthetic microorganisms. These include high susceptibility to invading aquatic consumers and weeds, as well as prodigious requirements for nutrients that may compete with the fertiliser demands of other crops. Most research on algal biofuel technologies approaches these problems from a cellular or genetic perspective, attempting either to engineer or select algal strains with particular traits. However, inherent functional trade-offs may limit the capacity of genetic selection or synthetic biology to simultaneously optimise multiple functional traits for biofuel productivity and resilience. We argue that a community engineering approach that manages microalgal diversity, species composition and environmental conditions may lead to more robust and productive biofuel ecosystems. We review evidence for trade-offs, challenges and opportunities in algal biofuel cultivation with a goal of guiding research towards intensifying bioenergy production using established principles of community and ecosystem ecology. © 2013 John Wiley & Sons Ltd/CNRS.

  6. Biomanipulation with quagga mussels (Dreissena rostriformis bugensis) to control harmful algal blooms in eutrophic urban ponds

    NARCIS (Netherlands)

    Waajen, Guido W. A. M.; Van Bruggen, Niek C. B.; Pires, L. Miguel Dionisio; Lengkeek, Wouter; Lurling, Miquel

    Many urban ponds in The Netherlands and other countries suffer from eutrophication, resulting in harmful algal blooms which are often dominated by cyanobacteria. A sufficient reduction of nutrients, as prerequisite to mitigate cyanobacterial blooms in urban ponds, is not always feasible. Water

  7. Maintenance of algal endosymbionts in Paramecium bursaria: a simple model based on population dynamics.

    Science.gov (United States)

    Iwai, Sosuke; Fujiwara, Kenji; Tamura, Takuro

    2016-09-01

    Algal endosymbiosis is widely distributed in eukaryotes including many protists and metazoans, and plays important roles in aquatic ecosystems, combining phagotrophy and phototrophy. To maintain a stable symbiotic relationship, endosymbiont population size in the host must be properly regulated and maintained at a constant level; however, the mechanisms underlying the maintenance of algal endosymbionts are still largely unknown. Here we investigate the population dynamics of the unicellular ciliate Paramecium bursaria and its Chlorella-like algal endosymbiont under various experimental conditions in a simple culture system. Our results suggest that endosymbiont population size in P. bursaria was not regulated by active processes such as cell division coupling between the two organisms, or partitioning of the endosymbionts at host cell division. Regardless, endosymbiont population size was eventually adjusted to a nearly constant level once cells were grown with light and nutrients. To explain this apparent regulation of population size, we propose a simple mechanism based on the different growth properties (specifically the nutrient requirements) of the two organisms, and based from this develop a mathematical model to describe the population dynamics of host and endosymbiont. The proposed mechanism and model may provide a basis for understanding the maintenance of algal endosymbionts. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  8. 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.

  9. Progress on lipid extraction from wet algal biomass for biodiesel production.

    Science.gov (United States)

    Ghasemi Naghdi, Forough; González González, Lina M; Chan, William; Schenk, Peer M

    2016-11-01

    Lipid recovery and purification from microalgal cells continues to be a significant bottleneck in biodiesel production due to high costs involved and a high energy demand. Therefore, there is a considerable necessity to develop an extraction method which meets the essential requirements of being safe, cost-effective, robust, efficient, selective, environmentally friendly, feasible for large-scale production and free of product contamination. The use of wet concentrated algal biomass as a feedstock for oil extraction is especially desirable as it would avoid the requirement for further concentration and/or drying. This would save considerable costs and circumvent at least two lengthy processes during algae-based oil production. This article provides an overview on recent progress that has been made on the extraction of lipids from wet algal biomass. The biggest contributing factors appear to be the composition of algal cell walls, pre-treatments of biomass and the use of solvents (e.g. a solvent mixture or solvent-free lipid extraction). We compare recently developed wet extraction processes for oleaginous microalgae and make recommendations towards future research to improve lipid extraction from wet algal biomass. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  10. Effect of algal density in bead, bead size and bead concentrations ...

    African Journals Online (AJOL)

    Laboratory experiments were performed to study nitrogen and phosphorus uptake by the unicellular green microalga Chlorella vulgaris immobilized in calcium alginate beads. Different cell stockings in beads, different bead sizes and different algal bead concentrations in wastewaters were tested. Significant higher nutrients ...

  11. 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...

  12. 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

  13. Study on freshwater algal flora on the territory of the Bulgarka Nature Park

    Directory of Open Access Journals (Sweden)

    Plamen Stoyanov

    2016-09-01

    Full Text Available The study presents data on the diversity of freshwater algal flora on the territory of the Bulgarka Nature Park. One hundred ninety-four species, belonging to 11 divisions were identified. The conservation value of the identified species was assessed.

  14. Predicting algal growth inhibition toxicity: three-step strategy using structural and physicochemical properties.

    Science.gov (United States)

    Furuhama, A; Hasunuma, K; Hayashi, T I; Tatarazako, N

    2016-05-01

    We propose a three-step strategy that uses structural and physicochemical properties of chemicals to predict their 72 h algal growth inhibition toxicities against Pseudokirchneriella subcapitata. In Step 1, using a log D-based criterion and structural alerts, we produced an interspecies QSAR between algal and acute daphnid toxicities for initial screening of chemicals. In Step 2, we categorized chemicals according to the Verhaar scheme for aquatic toxicity, and we developed QSARs for toxicities of Class 1 (non-polar narcotic) and Class 2 (polar narcotic) chemicals by means of simple regression with a hydrophobicity descriptor and multiple regression with a hydrophobicity descriptor and a quantum chemical descriptor. Using the algal toxicities of the Class 1 chemicals, we proposed a baseline QSAR for calculating their excess toxicities. In Step 3, we used structural profiles to predict toxicity either quantitatively or qualitatively and to assign chemicals to the following categories: Pesticide, Reactive, Toxic, Toxic low and Uncategorized. Although this three-step strategy cannot be used to estimate the algal toxicities of all chemicals, it is useful for chemicals within its domain. The strategy is also applicable as a component of Integrated Approaches to Testing and Assessment.

  15. Two-stage heterotrophic and phototrophic culture strategy for algal biomass and lipid production.

    Science.gov (United States)

    Zheng, Yubin; Chi, Zhanyou; Lucker, Ben; Chen, Shulin

    2012-01-01

    A two-stage heterotrophic and phototrophic culture strategy for algal biomass and lipid production was studied, wherein high density heterotrophic cultures of Chlorellasorokiniana serve as seed for subsequent phototrophic growth. The data showed growth rate, cell density and productivity of heterotrophic C.sorokiniana were 3.0, 3.3 and 7.4 times higher than phototrophic counterpart, respectively. Hetero- and phototrophic algal seeds had similar biomass/lipid production and fatty acid profile when inoculated into phototrophic culture system. To expand the application, food waste and wastewater were tested as feedstock for heterotrophic growth, and supported cell growth successfully. These results demonstrated the advantages of using heterotrophic algae cells as seeds for open algae culture system. Additionally, high inoculation rate of heterotrophic algal seed can be utilized as an effective method for contamination control. This two-stage heterotrophic phototrophic process is promising to provide a more efficient way for large scale production of algal biomass and biofuels. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Review and Evaluation of Reservoir Management Strategies for Harmful Algal Blooms

    Science.gov (United States)

    2017-07-28

    Abstract The purpose of this report is to review and evaluate available infor- mation regarding reservoir operation strategies for management of...12 3 Operations Management Examples ............................................................................ 16...report is to review and evaluate available information regarding reservoir operation strategies for management of harmful algal ERDC/EL TR-17-11 2

  17. Algal Turf Scrubbers: Cleaning Water while Capturing Solar Energy for Bio fuel Production

    International Nuclear Information System (INIS)

    Jeffrey Bannon, J.; Adey, W.

    2010-01-01

    Algal Turfs are bio diverse communities of unicellular to filamentous algae of all major algal phyla. Algal Turf Scrubbers (ATS) are bioengineered ecosystems dominated by algal turfs. They clean water to very high quality, and remove CO 2 from the atmosphere by capturing solar energy at rates 10 times that of agriculture and 50 times that of forestry. Since they are controlled ecosystems, using local algae, ATS does not suffer the major disadvantages of agricultural crops, which for maximum efficiency require fertilizers, herbicides and pesticides. ATS removes CO 2 from water and the atmosphere, and can be configured to remove CO 2 from power plant stack gases. As a normal part of operations, ATS removes heavy metals, break down toxic hydrocarbons, and oxygenates treated waters. ATS systems are capable of removing nitrogen and phosphorous from surface waters in the mid latitude US at $0.60/kg and $10.60/kg respectively (10% of the cost certified by the Chesapeake Bay Commission), and independently producing an energy product at $0.85/gallon. Given a nutrient credit system for rewarding nutrient removal from rivers and lakes, this price can be driven down to below $.40/gallon. Conservatively ATS can produce the equivalent of US imported oil on less than 30 M acres of land along major rivers

  18. Monitoring of ocean surface algal blooms in coastal and oceanic waters around India.

    Digital Repository Service at National Institute of Oceanography (India)

    Tholkapiyan, M.; Shanmugam, P.; Suresh, T.

    of the MODIS-Aqua-derived OSABI (ocean surface algal bloom index) and its seasonal composite images report new information and comprehensive pictures of these blooms and their evolution stages in a wide variety of events occurred at different times of the years...

  19. Algal Biomass from Wastewater and Flue Gases as a Source of Bioenergy

    Directory of Open Access Journals (Sweden)

    Sandra Lage

    2018-03-01

    Full Text Available Algae are without doubt the most productive photosynthetic organisms on Earth; they are highly efficient in converting CO2 and nutrients into biomass. These abilities can be exploited by culturing microalgae from wastewater and flue gases for effective wastewater reclamation. Algae are known to remove nitrogen and phosphorus as well as several organic contaminants including pharmaceuticals from wastewater. Biomass production can even be enhanced by the addition of CO2 originating from flue gases. The algal biomass can then be used as a raw material to produce bioenergy; depending on its composition, various types of biofuels such as biodiesel, biogas, bioethanol, biobutanol or biohydrogen can be obtained. However, algal biomass generated in wastewater and flue gases also contains contaminants which, if not degraded, will end up in the ashes. In this review, the current knowledge on algal biomass production in wastewater and flue gases is summarized; special focus is given to the algal capacity to remove contaminants from wastewater and flue gases, and the consequences when converting this biomass into different types of biofuels.

  20. Clarifying functional roles: algal removal by the surgeonfishes Ctenochaetus striatus and Acanthurus nigrofuscus

    Science.gov (United States)

    Tebbett, Sterling B.; Goatley, Christopher H. R.; Bellwood, David R.

    2017-09-01

    The lined bristletooth, Ctenochaetus striatus, and the brown surgeonfish, Acanthurus nigrofuscus, are among the most abundant surgeonfishes on Indo-Pacific coral reefs. Yet, the functional role of these species has been the focus of an ongoing debate lasting at least six decades. Specifically, to what extent are C. striatus herbivorous like the visually similar A. nigrofuscus? To address this question, we used natural feeding surfaces, covered with late successional stage reef-grown algal turfs, to examine turf algal removal by the two species. Surfaces exposed to C. striatus in laboratory experiments exhibited no significant reductions in turf length or area covered by turfing algae. In marked contrast, A. nigrofuscus reduced turf length by 51% and area covered by turfing algae by 15% in 1 h. The gut contents of specimens from the reef revealed that A. nigrofuscus predominantly ingests algae (the dominant item in 79.6-94.7% of gut content quadrats), while C. striatus ingests detritus and sediments (dominant in 99.6-100% of quadrats). Therefore, C. striatus ingests detritus and sediment, leaving mature algal turfs relatively intact, while A. nigrofuscus directly removes and ingests turf algae. The function of C. striatus differs from cropping herbivorous surgeonfishes such as A. nigrofuscus. On coral reefs, C. striatus brush detrital aggregates from algal turfs, removing microorganisms, organic detritus and inorganic sediment. Confusion over the functional role of C. striatus may stem from an inability to fit it into a single functional category.

  1. A new measure to study phylogenetic relations in the brown algal ...

    Indian Academy of Sciences (India)

    We analyse forty-seven chloroplast genes of the large subunit of RuBisCO, from the algal order Ectocarpales, sourced from GenBank. Codon-usage weighted by the nucleotide base-bias defines our score called the codon-impact-parameter. This score is used to obtain phylogenetic relations amongst the 47 Ectocarpales.

  2. The Cyanobacteria Assessment Network - Recent Success in Harmful Algal Bloom Detection

    Science.gov (United States)

    Cyanobacteria blooms, which can become harmful algal blooms (HABs), are a huge environmental problem across the United States. They are capable of producing dangerous toxins that threaten the health of humans and animals, quality of drinking water supplies, and the ecosystem in w...

  3. A new measure to study phylogenetic relations in the brown algal ...

    Indian Academy of Sciences (India)

    Unknown

    our classification with the ones done earlier. [Das S, Chakrabarti J, Ghosh Z, Sahoo S and Mallick B 2005 A new measure to study phylogenetic relations in the brown algal order Ectocarpales: The “codon impact parameter”; J. Biosci. 30 699–709]. 1. Introduction. Algae have grown in importance all over the world. Today.

  4. Determination of Total Solids and Ash in Algal Biomass: Laboratory Analytical Procedure (LAP)

    Energy Technology Data Exchange (ETDEWEB)

    Van Wychen, Stefanie; Laurens, Lieve M. L.

    2016-01-13

    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 deg. C is covered for ash content.

  5. 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.

  6. Investigation of severe UF membrane fouling induced by three marine algal species

    KAUST Repository

    Merle, Tony; Dramas, Laure; Gutierrez, Leonardo; Garcia-Molina, Veronica; Croue, Jean-Philippe

    2016-01-01

    Index (HIFI) was correlated to their biopolymer content but this correlation is specific for each species. Solution pre-filtration through a 1.2 μm membrane proved that cells and particulate algal organic matter (p-AOM) considerably contribute to fouling

  7. Mitigation of algal organic matter released from Chaetoceros affinis and Hymenomonas by in situ generated ferrate

    KAUST Repository

    Deka, Bhaskar Jyoti; Jeong, Sanghyun; AlizadehTabatabai, S.Assiyeh; An, Alicia Kyoungjin

    2018-01-01

    This study demonstrates the application of in situ ferrate (Fe(VI)) for the efficient removal of dissolved algal organic matter (AOM) from seawater. Sodium hypochlorite (NaOCl) and ferric (Fe(III)) were used to produce in situ Fe(VI) by wet chemical

  8. 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

  9. Deep water marine algal flora of the submerged banks off west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Ambiye, V.; Untawale, A.G.

    A survey of submerged banks off India viz Cora Divh, Sessostris and Bassas de-Pedro resulted in obtaining information on the rich and diverse marine algal flora from various depths ranging from 18-70 m. A programme of onboard dredging was undertaken...

  10. Physical abrasion method using submerged spike balls to remove algal biofilm from photobioreactors.

    Science.gov (United States)

    Nawar, Azra; Khoja, Asif Hussain; Akbar, Naveed; Ansari, Abeera Ayaz; Qayyum, Muneeb; Ali, Ehsan

    2017-12-02

    A major factor in practical application of photobioreactors (PBR) is the adhesion of algal cells onto their inner walls. Optimized algal growth requires an adequate sunlight for the photosynthesis and cell growth. Limitation in light exposure adversely affects the algal biomass yield. The removal of the biofilm from PBR is a challenging and expansive task. This study was designed to develop an inexpensive technique to prevent adhesion of algal biofilm on tubular PBR to ensure high efficiency of light utilization. Rubber balls with surface projections were introduced into the reactor, to remove the adherent biofilm by physical abrasion technique. The floatation of spike balls created a turbulent flow, thereby inhibiting further biofilm formation. The parameters such as, specific growth rate and doubling time of the algae before introducing the balls were 0.451 day -1 and 1.5 days respectively. Visible biofilm impeding light transmission was formed by 15-20 days. The removal of the biofilm commenced immediately after the introduction of the spike balls with visibly reduced deposits in 3 days. This was also validated by enhance cell count (6.95 × 106 cells mL -1 ) in the medium. The employment of spike balls in PBR is an environmental friendly and economical method for the removal of biofilm.

  11. Divergent composition of algal-bacterial biofilms developing under various external factors

    NARCIS (Netherlands)

    Barranguet, C.; Veuger, B.; van Beusekom, S.A.M.; Marvan, P.; Sinke, J.J.; Admiraal, W.

    2005-01-01

    The influence of external factors other than nutrients on biofilm development and composition was studied with a combination of optical (Confocal Laser Scanning Microscopy, PAM fluorometry) and chemical methods (EPS extraction, HPLC, TOC determination). The development of algal-bacterial biofilms

  12. Meiotic genes and sexual reproduction in the green algal class Trebouxiophyceae (Chlorophyta)

    Czech Academy of Sciences Publication Activity Database

    Fučíková, K.; Pažoutová, Marie; Rindi, F.

    2015-01-01

    Roč. 51, č. 3 (2015), s. 419-430 ISSN 0022-3646 Institutional support: RVO:60077344 Keywords : algal genomes * Chlorophyta * green algae * meiotic genes * sexual reproduction * Trebouxiophyceae Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.536, year: 2015

  13. Removal of algal blooms from freshwater by the coagulation-magnetic separation method.

    Science.gov (United States)

    Liu, Dan; Wang, Peng; Wei, Guanran; Dong, Wenbo; Hui, Franck

    2013-01-01

    This research investigated the feasibility of changing waste into useful materials for water treatment and proposed a coagulation-magnetic separation technique. This technique was rapid and highly effective for clearing up harmful algal blooms in freshwater and mitigating lake eutrophication. A magnetic coagulant was synthesized by compounding acid-modified fly ash with magnetite (Fe(3)O(4)). Its removal effects on algal cells and dissolved organics in water were studied. After mixing, coagulation, and magnetic separation, the flocs obtained from the magnet surface were examined by SEM. Treated samples were withdrawn for the content determination of chlorophyll-a, turbidity, chemical oxygen demand (COD), total nitrogen, and total phosphorus. More than 99 % of algal cells were removed within 5 min after the addition of magnetic coagulant at optimal loadings (200 mg L(-1)). The removal efficiencies of COD, total nitrogen, and phosphorus were 93, 91, and 94 %, respectively. The mechanism of algal removal explored preliminarily showed that the magnetic coagulant played multiple roles in mesoporous adsorption, netting and bridging, as well as high magnetic responsiveness to a magnetic field. The magnetic-coagulation separation method can rapidly and effectively remove algae from water bodies and greatly mitigate eutrophication of freshwater using a new magnetic coagulant. The method has good performance, is low cost, can turn waste into something valuable, and provides reference and directions for future pilot and production scale-ups.

  14. Development of a novel artificial medium based on utilization of algal photosynthetic metabolites by symbiotic heterotrophs.

    Science.gov (United States)

    Watanabe, K; Imase, M; Aoyagi, H; Ohmura, N; Saiki, H; Tanaka, H

    2008-09-01

    (i) Quantitative and qualitative analyses of photosynthetic metabolites of Chlorella sorokiniana and elucidation of the mechanism of their utilization by algal symbionts. (ii) Development of artificial medium that imitates photoautotroph-heterotroph interaction and investigation of its suitability for isolation of novel microbes from the environment. Various components, including free dissolved carbohydrates, nitrogenous compounds and vitamin, were detected and together contributed 11.1% (as carbon content) of the total photosynthetic metabolites in the medium. Utilization of these photosynthetic metabolites in algal culture broth by algal symbionts was studied. Many symbionts showed specific utilization patterns. A novel artificial extracellular released organic carbon medium, which imitated the nutritional conditions surrounding algae, was developed based on the pattern of utilization of the algal metabolites by the symbiotic heterotrophs. About 42.9% of the isolates were closely related to photoautotrophic-dependent and oligotrophic bacteria. With the novel artificial medium, it was possible to selectively isolate some bacterial strains. Synthetic bacterial growth medium is an important and basic tool for bacterial isolation from environmental samples. The current study shows that preferential separation of typical bacterial subset can be achieved by using artificial medium that mimics photosynthetic metabolites.

  15. 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.

  16. Satellite monitoring of cyanobacterial harmful algal bloom frequency in recreational waters and drinking water sources

    Science.gov (United States)

    Cyanobacterial harmful algal blooms (cyanoHABs) cause extensive problems in lakes worldwide, including human and ecological health risks, anoxia and fish kills, and taste and odor problems. CyanoHABs are a particular concern because of their dense biomass and the risk of expos...

  17. Using Multi-media Modeling to Investigate Conditions Leading to Harmful Algal Blooms

    Science.gov (United States)

    Lake Erie is the twelfth largest lake in the world and provides drinking water to over 11 million people in the United States. 22,720 square miles of varying landcover (e.g., urban, agriculture) drain directly into Lake Erie. Harmful algal blooms (HABs) have historically been an ...

  18. Combinatorial Life Cycle Assessment to Inform Process Design of Industrial Production of Algal Biodiesel

    NARCIS (Netherlands)

    Brentner, L.B.; Eckelman, M.J.; Zimmerman, J.B.

    2011-01-01

    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

  19. The Enzymatic Conversion of Major Algal and Cyanobacterial Carbohydrates to Bioethanol

    Energy Technology Data Exchange (ETDEWEB)

    Al Abdallah, Qusai, E-mail: qalabdal@uthsc.edu [Department of Clinical Pharmacy, University of Tennessee Health Science Center, Memphis, TN (United States); Nixon, B. Tracy [Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA (United States); Fortwendel, Jarrod R. [Department of Clinical Pharmacy, University of Tennessee Health Science Center, Memphis, TN (United States)

    2016-11-04

    The production of fuels from biomass is categorized as first-, second-, or third-generation depending upon the source of raw materials, either food crops, lignocellulosic material, or algal biomass, respectively. Thus far, the emphasis has been on using food crops creating several environmental problems. To overcome these problems, there is a shift toward bioenergy production from non-food sources. Algae, which store high amounts of carbohydrates, are a potential producer of raw materials for sustainable production of bioethanol. Algae store their carbohydrates in the form of food storage sugars and structural material. In general, algal food storage polysaccharides are composed of glucose subunits; however, they vary in the glycosidic bond that links the glucose molecules. In starch-type polysaccharides (starch, floridean starch, and glycogen), the glucose subunits are linked together by α-(1→4) and α-(1→6) glycosidic bonds. Laminarin-type polysaccharides (laminarin, chrysolaminarin, and paramylon) are made of glucose subunits that are linked together by β-(1→3) and β-(1→6) glycosidic bonds. In contrast to food storage polysaccharides, structural polysaccharides vary in composition and glycosidic bond. The industrial production of bioethanol from algae requires efficient hydrolysis and fermentation of different algal sugars. However, the hydrolysis of algal polysaccharides employs more enzymatic mixes in comparison to terrestrial plants. Similarly, algal fermentable sugars display more diversity than plants, and therefore more metabolic pathways are required to produce ethanol from these sugars. In general, the fermentation of glucose, galactose, and glucose isomers is carried out by wild-type strains of Saccharomyces cerevisiae and Zymomonas mobilis. In these strains, glucose enters glycolysis, where is it converted to pyruvate through either Embden–Meyerhof–Parnas pathway or Entner–Doudoroff pathway. Other monosaccharides must be converted to

  20. The Enzymatic Conversion of Major Algal and Cyanobacterial Carbohydrates to Bioethanol

    International Nuclear Information System (INIS)

    Al Abdallah, Qusai; Nixon, B. Tracy; Fortwendel, Jarrod R.

    2016-01-01

    The production of fuels from biomass is categorized as first-, second-, or third-generation depending upon the source of raw materials, either food crops, lignocellulosic material, or algal biomass, respectively. Thus far, the emphasis has been on using food crops creating several environmental problems. To overcome these problems, there is a shift toward bioenergy production from non-food sources. Algae, which store high amounts of carbohydrates, are a potential producer of raw materials for sustainable production of bioethanol. Algae store their carbohydrates in the form of food storage sugars and structural material. In general, algal food storage polysaccharides are composed of glucose subunits; however, they vary in the glycosidic bond that links the glucose molecules. In starch-type polysaccharides (starch, floridean starch, and glycogen), the glucose subunits are linked together by α-(1→4) and α-(1→6) glycosidic bonds. Laminarin-type polysaccharides (laminarin, chrysolaminarin, and paramylon) are made of glucose subunits that are linked together by β-(1→3) and β-(1→6) glycosidic bonds. In contrast to food storage polysaccharides, structural polysaccharides vary in composition and glycosidic bond. The industrial production of bioethanol from algae requires efficient hydrolysis and fermentation of different algal sugars. However, the hydrolysis of algal polysaccharides employs more enzymatic mixes in comparison to terrestrial plants. Similarly, algal fermentable sugars display more diversity than plants, and therefore more metabolic pathways are required to produce ethanol from these sugars. In general, the fermentation of glucose, galactose, and glucose isomers is carried out by wild-type strains of Saccharomyces cerevisiae and Zymomonas mobilis. In these strains, glucose enters glycolysis, where is it converted to pyruvate through either Embden–Meyerhof–Parnas pathway or Entner–Doudoroff pathway. Other monosaccharides must be converted to

  1. The enzymatic conversion of major algal and cyanobacterial carbohydrates to bioethanol

    Directory of Open Access Journals (Sweden)

    Qusai Al Abdallah

    2016-11-01

    Full Text Available The production of fuels from biomass is categorized as first-, second- or third-generation depending upon the source of raw materials, either food crops, lignocellulosic material, or algal biomass, respectively. Thus far, the emphasis has been on using food crops creating several environmental problems. To overcome these problems, there is a shift toward bioenergy production from non-food sources. Algae, which store high amounts of carbohydrates, are a potential producer of raw materials for sustainable production of bioethanol. Algae store their carbohydrates in the form of food storage sugars and structural material. In general, algal food storage polysaccharides are composed of glucose subunits, however they vary in the glycosidic bond that links the glucose molecules. In starch-type polysaccharides (starch, floridean starch, and glycogen, the glucose subunits are linked together by α-(1→4 and α-(1→6 glycosidic bonds. Laminarin-type polysaccharides (laminarin, chrysolaminarin, and paramylon are made of glucose subunits that are linked together by β-(1→3 and β-(1→6 glycosidic bonds. In contrast to food storage polysaccharides, structural polysaccharides vary in composition and glycosidic bond. The industrial production of bioethanol from algae requires efficient hydrolysis and fermentation of different algal sugars. However, the hydrolysis of algal polysaccharides employs more enzymatic mixes in comparison to terrestrial plants. Similarly, algal fermentable sugars display more diversity than plants, and therefore more metabolic pathways are required to produce ethanol from these sugars. In general, the fermentation of glucose, galactose, and glucose isomers is carried out by wild type strains of Saccharomyces cerevisiae and Zymomonas mobilis. In these strains, glucose enters glycolysis, where is it converted to pyruvate through either Embden-Meyerhof-Parnas pathway or Entner-Doudoroff pathway. Other monosaccharides must be

  2. Primary production of edaphic algal communities in a Mississippi salt marsh

    International Nuclear Information System (INIS)

    Sullivan, M.J.; Moncreiff, C.A.

    1988-01-01

    Primary production rates of edaphic algae associated with the sediments beneath four monospecific canopies of vascular plants were determined over an annual cycle in a Mississippi salt marsh. The edaphic algal flora was dominated by small, motile pennate diatoms. Algal production (as measured by 14 C uptake) was generally highest in spring-early summer and lowest in fall. Hourly rates ranged from a low of 1.4 mg C/m 2 in Juncus roemerianus Scheele to a high of 163 mg C/m 2 beneath the Scirpus olneyi Gray canopy. Stepwise multiple regressions identified a soil moisture index and chlorophyll a as the best environmental predictors of hourly production; light energy reaching the marsh surface and sediment and air temperature proved of little value. Adding the relative abundances of 33 diatom taxa to the set of independent variables only slightly increased R 2 ; however, virtually all variables selected were diatom taxa. R 2 was only 0.38 for the Spartina alterniflora Loisel. habitat but ranged from 0.70 to 0.87 for the remaining three vascular plant zones. Annual rates of algal production (g C/m 2 ) were estimated as follows: Juncus (28), Spartina (57), Distichlis spicata (L.) Greene (88), and Scirpus (151). The ratio of annual edaphic algal production to vascular plant net aerial production (EAP/VPP) was 10-12% for the first three habitats and 61% for Scirpus. Chlorophyll a concentrations, annual algal production rates, and EAP/VPP values were comparable to those determined in Texas, Delaware, and Massachusetts salt marshes but lower than those reported for Georgia and particularly California marshes

  3. Phylogenetic analysis of algal symbionts associated with four North American amphibian egg masses.

    Science.gov (United States)

    Kim, Eunsoo; Lin, Yuan; Kerney, Ryan; Blumenberg, Lili; Bishop, Cory

    2014-01-01

    Egg masses of the yellow-spotted salamander Ambystoma maculatum form an association with the green alga "Oophila amblystomatis" (Lambert ex Wille), which, in addition to growing within individual egg capsules, has recently been reported to invade embryonic tissues and cells. The binomial O. amblystomatis refers to the algae that occur in A. maculatum egg capsules, but it is unknown whether this population of symbionts constitutes one or several different algal taxa. Moreover, it is unknown whether egg masses across the geographic range of A. maculatum, or other amphibians, associate with one or multiple algal taxa. To address these questions, we conducted a phylogeographic study of algae sampled from egg capsules of A. maculatum, its allopatric congener A. gracile, and two frogs: Lithobates sylvatica and L. aurora. All of these North American amphibians form associations with algae in their egg capsules. We sampled algae from egg capsules of these four amphibians from localities across North America, established representative algal cultures, and amplified and sequenced a region of 18S rDNA for phylogenetic analysis. Our combined analysis shows that symbiotic algae found in egg masses of four North American amphibians are closely related to each other, and form a well-supported clade that also contains three strains of free-living chlamydomonads. We designate this group as the 'Oophila' clade, within which the symbiotic algae are further divided into four distinct subclades. Phylogenies of the host amphibians and their algal symbionts are only partially congruent, suggesting that host-switching and co-speciation both play roles in their associations. We also established conditions for isolating and rearing algal symbionts from amphibian egg capsules, which should facilitate further study of these egg mass specialist algae.

  4. Enhancement of fermentative hydrogen production from green algal biomass of Thermotoga neapolitana by various pretreatment methods

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Tam-Anh D.; Kim, Kyoung-Rok; Nguyen, Minh-Thu; Sim, Sang Jun [Department of Chemical Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Kim, Mi Sun [Bioenergy Research Center, Korea Institute of Energy Research, Daejeon 305-343 (Korea, Republic of); Kim, Donhue [Department of Biochemical Engineering, Dongyang Mirae College, Seoul 152-714 (Korea, Republic of)

    2010-12-15

    Biomass of the green algae has been recently an attractive feedstock source for bio-fuel production because the algal carbohydrates can be derived from atmospheric CO{sub 2} and their harvesting methods are simple. We utilized the accumulated starch in the green alga Chlamydomonas reinhardtii as the sole substrate for fermentative hydrogen (H{sub 2}) production by the hyperthermophilic eubacterium Thermotoga neapolitana. Because of possessing amylase activity, the bacterium could directly ferment H{sub 2} from algal starch with H{sub 2} yield of 1.8-2.2 mol H{sub 2}/mol glucose and the total accumulated H{sub 2} level from 43 to 49% (v/v) of the gas headspace in the closed culture bottle depending on various algal cell-wall disruption methods concluding sonication or methanol exposure. Attempting to enhance the H{sub 2} production, two pretreatment methods using the heat-HCl treatment and enzymatic hydrolysis were applied on algal biomass before using it as substrate for H{sub 2} fermentation. Cultivation with starch pretreated by 1.5% HCl at 121 C for 20 min showed the total accumulative H{sub 2} yield of 58% (v/v). In other approach, enzymatic digestion of starch by thermostable {alpha}-amylase (Termamyl) applied in the SHF process significantly enhanced the H{sub 2} productivity of the bacterium to 64% (v/v) of total accumulated H{sub 2} level and a H{sub 2} yield of 2.5 mol H{sub 2}/mol glucose. Our results demonstrated that direct H{sub 2} fermentation from algal biomass is more desirably potential because one bacterial cultivation step was required that meets the cost-savings, environmental friendly and simplicity of H{sub 2} production. (author)

  5. Factors Controlling Changes in Epilithic Algal Biomass in the Mountain Streams of Subtropical Taiwan.

    Directory of Open Access Journals (Sweden)

    Yi-Ming Kuo

    Full Text Available In upstream reaches, epilithic algae are one of the major primary producers and their biomass may alter the energy flow of food webs in stream ecosystems. However, the overgrowth of epilithic algae may deteriorate water quality. In this study, the effects of environmental variables on epilithic algal biomass were examined at 5 monitoring sites in mountain streams of the Wuling basin of subtropical Taiwan over a 5-year period (2006-2011 by using a generalized additive model (GAM. Epilithic algal biomass and some variables observed at pristine sites obviously differed from those at the channelized stream with intensive agricultural activity. The results of the optimal GAM showed that water temperature, turbidity, current velocity, dissolved oxygen (DO, pH, and ammonium-N (NH4-N were the main factors explaining seasonal variations of epilithic algal biomass in the streams. The change points of smoothing curves for velocity, DO, NH4-N, pH, turbidity, and water temperature were approximately 0.40 m s-1, 8.0 mg L-1, 0.01 mg L-1, 8.5, 0.60 NTU, and 15°C, respectively. When aforementioned variables were greater than relevant change points, epilithic algal biomass was increased with pH and water temperature, and decreased with water velocity, DO, turbidity, and NH4-N. These change points may serve as a framework for managing the growth of epilithic algae. Understanding the relationship between environmental variables and epilithic algal biomass can provide a useful approach for maintaining the functioning in stream ecosystems.

  6. Phylogenetic analysis of algal symbionts associated with four North American amphibian egg masses.

    Directory of Open Access Journals (Sweden)

    Eunsoo Kim

    Full Text Available Egg masses of the yellow-spotted salamander Ambystoma maculatum form an association with the green alga "Oophila amblystomatis" (Lambert ex Wille, which, in addition to growing within individual egg capsules, has recently been reported to invade embryonic tissues and cells. The binomial O. amblystomatis refers to the algae that occur in A. maculatum egg capsules, but it is unknown whether this population of symbionts constitutes one or several different algal taxa. Moreover, it is unknown whether egg masses across the geographic range of A. maculatum, or other amphibians, associate with one or multiple algal taxa. To address these questions, we conducted a phylogeographic study of algae sampled from egg capsules of A. maculatum, its allopatric congener A. gracile, and two frogs: Lithobates sylvatica and L. aurora. All of these North American amphibians form associations with algae in their egg capsules. We sampled algae from egg capsules of these four amphibians from localities across North America, established representative algal cultures, and amplified and sequenced a region of 18S rDNA for phylogenetic analysis. Our combined analysis shows that symbiotic algae found in egg masses of four North American amphibians are closely related to each other, and form a well-supported clade that also contains three strains of free-living chlamydomonads. We designate this group as the 'Oophila' clade, within which the symbiotic algae are further divided into four distinct subclades. Phylogenies of the host amphibians and their algal symbionts are only partially congruent, suggesting that host-switching and co-speciation both play roles in their associations. We also established conditions for isolating and rearing algal symbionts from amphibian egg capsules, which should facilitate further study of these egg mass specialist algae.

  7. Dynamics of Bacterial and Fungal Communities during the Outbreak and Decline of an Algal Bloom in a Drinking Water Reservoir.

    Science.gov (United States)

    Zhang, Haihan; Jia, Jingyu; Chen, Shengnan; Huang, Tinglin; Wang, Yue; Zhao, Zhenfang; Feng, Ji; Hao, Huiyan; Li, Sulin; Ma, Xinxin

    2018-02-18

    The microbial communities associated with algal blooms play a pivotal role in organic carbon, nitrogen and phosphorus cycling in freshwater ecosystems. However, there have been few studies focused on unveiling the dynamics of bacterial and fungal communities during the outbreak and decline of algal blooms in drinking water reservoirs. To address this issue, the compositions of bacterial and fungal communities were assessed in the Zhoucun drinking water reservoir using 16S rRNA and internal transcribed spacer (ITS) gene Illumina MiSeq sequencing techniques. The results showed the algal bloom was dominated by Synechococcus, Microcystis, and Prochlorothrix. The bloom was characterized by a steady decrease of total phosphorus (TP) from the outbreak to the decline period (p Limnobacter sp., Synechococcus sp., and Roseomonas sp. The relative size of the fungal community also changed with algal bloom and its composition mainly contained Ascomycota, Basidiomycota and Chytridiomycota. Heat map profiling indicated that algal bloom had a more consistent effect upon fungal communities at genus level. Redundancy analysis (RDA) also demonstrated that the structure of water bacterial communities was significantly correlated to conductivity and ammonia nitrogen. Meanwhile, water temperature, Fe and ammonia nitrogen drive the dynamics of water fungal communities. The results from this work suggested that water bacterial and fungal communities changed significantly during the outbreak and decline of algal bloom in Zhoucun drinking water reservoir. Our study highlights the potential role of microbial diversity as a driving force for the algal bloom and biogeochemical cycling of reservoir ecology.

  8. Relations between water physico-chemistry and benthic algal communities in a northern Canadian watershed: defining reference conditions using multiple descriptors of community structure.

    Science.gov (United States)

    Thomas, Kathryn E; Hall, Roland I; Scrimgeour, Garry J

    2015-09-01

    Defining reference conditions is central to identifying environmental effects of anthropogenic activities. Using a watershed approach, we quantified reference conditions for benthic algal communities and their relations to physico-chemical conditions in rivers in the South Nahanni River watershed, NWT, Canada, in 2008 and 2009. We also compared the ability of three descriptors that vary in terms of analytical costs to define algal community structure based on relative abundances of (i) all algal taxa, (ii) only diatom taxa, and (iii) photosynthetic pigments. Ordination analyses showed that variance in algal community structure was strongly related to gradients in environmental variables describing water physico-chemistry, stream habitats, and sub-watershed structure. Water physico-chemistry and local watershed-scale descriptors differed significantly between algal communities from sites in the Selwyn Mountain ecoregion compared to sites in the Nahanni-Hyland ecoregions. Distinct differences in algal community types between ecoregions were apparent irrespective of whether algal community structure was defined using all algal taxa, diatom taxa, or photosynthetic pigments. Two algal community types were highly predictable using environmental variables, a core consideration in the development of Reference Condition Approach (RCA) models. These results suggest that assessments of environmental impacts could be completed using RCA models for each ecoregion. We suggest that use of algal pigments, a high through-put analysis, is a promising alternative compared to more labor-intensive and costly taxonomic approaches for defining algal community structure.

  9. Environmental status of algal mat sites located at the east coast of Saudi Arabia following the Gulf War

    International Nuclear Information System (INIS)

    Al-Thukair, A.

    1993-01-01

    Remote sensing techniques and ground truth verification were used to provide information on algal mat locations and damage intensity caused by the oil spill. Pre and post oil spill satellite images, ground truth assessment were compared for damage evaluation. Locations and sites status (heavily oiled, recovering, and no algal mats) were conveyed in maps. Recovered sites are found in Abu Ali and Tanajib areas. However, recovery seems to be slower in Abu Ali area as compared to Tanajib. Different types and formations of algal mats were found in both areas. This differentiation is more likely to be attributable to coastal topography and tide regimes

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

    KAUST Repository

    Nihemaiti, Maolida

    2014-01-01

    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

  11. Remote sensing of cyanobacteria-dominant algal blooms and water quality parameters in Zeekoevlei, a small hypertrophic lake, using MERIS

    CSIR Research Space (South Africa)

    Matthews, MW

    2010-09-01

    Full Text Available Eutrophication and cyanobacterial algal blooms present an increasing threat to the health of freshwater ecosystems and to humans who use these resources for drinking and recreation. Remote sensing is being used increasingly as a tool for monitoring...

  12. Herbivory on macro-algae affects colonization of beach-cast algal wrack by detritivores but not its decomposition

    Directory of Open Access Journals (Sweden)

    Philip Eereveld

    2013-05-01

    Full Text Available Spatial subsidies have increasingly been considered significant sources of matter and energy to unproductive ecosystems. However, subsidy quality may both differ between subsidizing sources and vary over time. In our studies, sub-littoral herbivory by snails or isopods on red or brown macro-algae induced changes in algal tissues that affected colonization of beach-cast algal wrack by supra-littoral detritivores (amphipods. However, microbial decay and decomposition through the joint action of detritivores and microbes of algal wrack in the supra-littoral remained unaffected by whether or not red or brown algae had been fed upon by snails or isopods. Thus, herbivory on marine macro-algae affects the cross-system connection of sub-littoral and supra-littoral food webs transiently, but these effects diminish upon ageing of macro-algal wrack in the supra-littoral zone.

  13. Irish Marine Institute biotoxin, phytoplankton and remote sensing data for Harmful Algal Event monitoring Identification Information (NODC Accession 0000668)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The presence of harmful algal species, which produce toxins, pose a significant threat to public health and coastal aquaculture activities. For example, estimated...

  14. A method for examining temporal changes in cyanobacterial harmful algal bloom spatial extent using satellite remote sensing..

    Science.gov (United States)

    Cyanobacterial harmful algal blooms (CyanoHAB) are thought to be increasing globally over the past few decades, but relatively little quantitative information is available about the spatial extent of blooms. Satellite remote sensing provides a potential technology for identifying...

  15. Turf algal epiphytes metabolically induce local pH increase, with implications for underlying coralline algae under ocean acidification

    DEFF Research Database (Denmark)

    Short, J.A.; Pedersen, Ole; Kendrick, G.A.

    2015-01-01

    The presence of epiphytic turf algae may modify the effects of ocean acidification on coralline algal calcification rates by altering seawater chemistry within the diffusive boundary layer (DBL) above coralline algal crusts. We used microelectrodes to measure the effects of turf algal epiphytes...... on seawater pH and the partial pressure of oxygen (pO2) within the DBL at the surface of Hydrolithoideae coralline algal crusts under ambient (36 Pa) CO2 and an ocean acidification scenario with elevated CO2 (200 Pa). Turf algae significantly increased the mean diel amplitude of pH and pO2, and this effect...... was more pronounced under elevated CO2. We suggest that increases in seawater CO2 under ocean acidification conditions may drive an increase in the abundance of epiphytic turf algae, consequently modifying the chemistry within the DBL. Thus, the effect of epiphytic turf algae on microscale pH is striking...

  16. Supercritical Algal Extracts: A Source of Biologically Active Compounds from Nature

    Directory of Open Access Journals (Sweden)

    Izabela Michalak

    2015-01-01

    Full Text Available The paper discusses the potential applicability of the process of supercritical fluid extraction (SFE in the production of algal extracts with the consideration of the process conditions and yields. State of the art in the research on solvent-free isolation of biologically active compounds from the biomass of algae was presented. Various aspects related with the properties of useful compounds found in cells of microalgae and macroalgae were discussed, including their potential applications as the natural components of plant protection products (biostimulants and bioregulators, dietary feed and food supplements, and pharmaceuticals. Analytical methods of determination of the natural compounds derived from algae were discussed. Algal extracts produced by SFE process enable obtaining a solvent-free concentrate of biologically active compounds; however, detailed economic analysis, as well as elaboration of products standardization procedures, is required in order to implement the products in the market.

  17. Biofouling in capillary and spiral wound membranes facilitated by marine algal bloom

    DEFF Research Database (Denmark)

    Villacorte, L.O.; Ekowati, Y.; Calix-Ponce, H.N.

    2017-01-01

    blooms. The tendency of AOM from bloom-forming marine algae to adhere to membranes and its ability to enhance biofilm growth were measured using atomic force microscopy, flow cytometry, liquid chromatography and accelerated membrane biofouling experiments. Adhesion force measurements indicate that AOM......Algal-derived organic matter (AOM), particularly transparent exopolymer particles, has been suspected to facilitate biofilm development in membrane systems (e.g., seawater reverse osmosis). This study demonstrates the possible role of AOM on biofouling in membrane systems affected by marine algal...... biodegradable nutrients. The abovementioned findings indicate that AOM facilitates the onset of membrane biofouling primarily as a conditioning platform and to some extent as a nutrient source for biofilm-forming bacteria....

  18. MBTH: A novel approach to rapid, spectrophotometric quantitation of total algal carbohydrates.

    Science.gov (United States)

    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 μg mL -1 without interference from other algae acidic hydrolyzate components. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Response of an algal consortium to diesel under varying culture conditions.

    Science.gov (United States)

    Chavan, Anal; Mukherji, Suparna

    2010-03-01

    A diesel-tolerant sessile freshwater algal consortium obtained from the vicinity of Powai Lake (Mumbai, India) was cultured in the laboratory. The presence of diesel in batch cultures enhanced the maximum specific growth rate of the algal consortium. With decrease in light-dark (L:D) cycle from 20:4 to 4:20 h, the chlorophyll-a levels decreased; however, the removal of diesel was found to be maximum at L:D of 18:6 h with 37.6% degradation over and above controls. In addition to growth in the form of green clumps, white floating biomass was found surrounding the diesel droplets on the surface. This culture predominated at the least L:D ratio of 4:20 h. Studies confirmed the ability of the floating organisms to grow heterotrophically in the dark utilizing diesel as carbon source and also in the presence of light in a medium devoid of organic carbon sources.

  20. Hydroclimatic conditions trigger record harmful algal bloom in western Patagonia (summer 2016).

    Science.gov (United States)

    León-Muñoz, Jorge; Urbina, Mauricio A; Garreaud, René; Iriarte, José Luis

    2018-01-22

    A harmful algal bloom (HAB) of the raphidophyta alga Pseudochattonella cf. verruculosa during the 2016 austral summer (February-March) killed nearly 12% of the Chilean salmon production, causing the worst mass mortality of fish and shellfish ever recorded in the coastal waters of western Patagonia. The HAB coincided with a strong El Niño event and the positive phase of the Southern Annular Mode that altered the atmospheric circulation in southern South America and the adjacent Pacific Ocean. This led to very dry conditions and higher than normal solar radiation reaching the surface. Using time series of atmospheric, hydrologic and oceanographic data we show here that an increase in surface water temperature and reduced freshwater input resulted in a weakening of the vertical stratification in the fjords and sounds of this region. This allowed the advection of more saline and nutrient-rich waters, ultimately resulting in an active harmful algal bloom in coastal southern Chile.

  1. Bioengineering aspects of inorganic carbon supply to mass algal cultures. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Goldman, J.C.

    1980-06-01

    The work included in this report is part of an ongoing study (currently funded by the Solar Energy Research Institute - Subcontract No. XR-9-8144-1) on the inorganic carbon requirements of microalgae under mass culture conditions and covers the period June 1, 1978 through May 31, 1979. It is divided into two parts appended herein. The first part is a literature review on the inorganic carbon chemical system in relation to algal growth requirements, and the second part deals with the kinetics of inorganic carbon-limited growth of two freshwater chlorophytes including the effect of carbon limitation on cellular chemical composition. Additional experiment research covered under this contract was reported in the Proceedings of the 3rd Annual Biomass Energy Systems Conferences, pp. 25-32, Bioengineering aspects of inorganic carbon supply to mass algal cultures. Report No. SERI/TP-33-285.

  2. Polyurethane and alginate immobilized algal biomass for the removal of aqueous toxic metals

    International Nuclear Information System (INIS)

    Fry, I.V.; Mehlhorn, R.J.

    1992-12-01

    We describe the development of immobilized, processed algal biomass for use as an adsorptive filter in the removal of toxic metals from waste water. To fabricate an adsorptive filter from precessed biomass several crucial criteria must be met, including: (1) high metal binding capacity, (2) long term stability (both mechanical and chemical), (3) selectivity for metals of concern (with regard to ionic competition), (4) acceptable flow capacity (to handle large volumes in short time frames), (5) stripping/regeneration (to recycle the adsorptive filter and concentrate the toxic metals to manageable volumes). This report documents experiments with processed algal biomass (Spirulina platensis and Spirulina maxima) immobilized in either alginate gel or preformed polyurethane foam. The adsorptive characteristics of these filters were assessed with regard to the criteria listed above

  3. Change in Photosystem II Photochemistry During Algal Growth Phases of Chlorella vulgaris and Scenedesmus obliquus.

    Science.gov (United States)

    Oukarroum, Abdallah

    2016-06-01

    Sensitivity of photosynthetic processes towards environmental stress is used as a bioanalytical tool to evaluate the responses of aquatic plants to a changing environment. In this paper, change of biomass density, chlorophyll a fluorescence and photosynthetic parameters during growth phases of two microalgae Chlorella vulgaris and Scenedesmus obliquus were studied. The photosynthetic growth behaviour changed significantly with cell age and algae species. During the exponential phase of growth, the photosynthesis capacity reached its maximum and decreased in ageing algal culture during stationary phase. In conclusion, the chlorophyll a fluorescence OJIP method and the derived fluorescence parameters would be an accurate method for obtaining information on maximum photosynthetic capacities and monitoring algal cell growth. This will contribute to more understanding, for example, of toxic actions of pollutants in microalgae test.

  4. Potential utilization of algal protein concentrate as a food ingredient in space habitats

    Science.gov (United States)

    Nakhost, Z.; Karel, M.

    1989-01-01

    Green alga Scenedesmus obliquus was studied as one of the potential sources of macronutrients in a space habitat. Algal protein concentrate (70.5% protein) was incorporated into a variety of food products such as bran muffins, fettuccine (spinach noodle imitation) and chocolate chip cookies. Food products containing 20 to 40% of incorporated algal proteins were considered. In the sensory analysis the greenish color of the bran muffins and cookies was not found to be objectional. The mild spinachy flavor (algae flavor) was less detectable in chocolate chip cookies than in bran muffins. The color and taste of the algae noodles were found to be pleasant and compared well with commercially available spinach noodles. Commercially available spray-dried Spirulina algae was also incorporated so the products can be compared with those containing Scenedesmus obliquus concentrate. Food products containing commercial algae had a dark green color and a "burnt after taste" and were less acceptable to the panelists.

  5. Bioaccumulation of heavy metals by freshwater algal species of Bhavnagar, Gujarat, India.

    Science.gov (United States)

    Jaiswar, Santial; Kazi, Mudassar Anisoddin; Mehta, Shailesh

    2015-11-01

    The present study investigated copper, cadmium, lead and zinc accumulation in algal species Oedogonium, Cladophora, Oscillatoria and Spirogyra from freshwater habitats of Bhavnagar, India. Eight different locations were periodically sampled during August 2009 to March 2011. The general trend of heavy metal concentrations in all the algal species in present study (except at few stations), were found to be in the following order: Zn > Cu > Pb > Cd. Highest accumulation of Cu was recorded in Oedogonium, while Cladophora showed highest accumulation of Pb signifying a good bioaccumulator. Oscillatoria and Oedogonium were highest Zn accumulating algae which showed significant difference between the means at P Cu > Pb > Cd. The present study showed that Oedogonium, Cladophora, Oscillatoria and Spirogyra were excellent bioaccumulator and could be utilized as biomonitoring agents in water bodies receiving waste contaminated by metals.

  6. Harmful algal blooms and climate change: Learning from the past and present to forecast the future

    Science.gov (United States)

    Wells, Mark L.; Trainer, Vera L.; Smayda, Theodore J.; Karlson, Bengt S.O.; Trick, Charles G.; Kudela, Raphael M.; Ishikawa, Akira; Bernard, Stewart; Wulff, Angela; Anderson, Donald M.; Cochlan, William P.

    2015-01-01

    Climate change pressures will influence marine planktonic systems globally, and it is conceivable that harmful algal blooms may increase in frequency and severity. These pressures will be manifest as alterations in temperature, stratification, light, ocean acidification, precipitation-induced nutrient inputs, and grazing, but absence of fundamental knowledge of the mechanisms driving harmful algal blooms frustrates most hope of forecasting their future prevalence. Summarized here is the consensus of a recent workshop held to address what currently is known and not known about the environmental conditions that favor initiation and maintenance of harmful algal blooms. There is expectation that harmful algal bloom (HAB) geographical domains should expand in some cases, as will seasonal windows of opportunity for harmful algal blooms at higher latitudes. Nonetheless there is only basic information to speculate upon which regions or habitats HAB species may be the most resilient or susceptible. Moreover, current research strategies are not well suited to inform these fundamental linkages. There is a critical absence of tenable hypotheses for how climate pressures mechanistically affect HAB species, and the lack of uniform experimental protocols limits the quantitative cross-investigation comparisons essential to advancement. A HAB “best practices” manual would help foster more uniform research strategies and protocols, and selection of a small target list of model HAB species or isolates for study would greatly promote the accumulation of knowledge. Despite the need to focus on keystone species, more studies need to address strain variability within species, their responses under multifactorial conditions, and the retrospective analyses of long-term plankton and cyst core data; research topics that are departures from the norm. Examples of some fundamental unknowns include how larger and more frequent extreme weather events may break down natural biogeographic

  7. Dinoflagellate community structure from the stratified environment of the Bay of Bengal, with special emphasis on harmful algal bloom species

    Digital Repository Service at National Institute of Oceanography (India)

    Naik, R.K.; Hegde, S.; Anil, A.C.

    the total marine phytoplankton species, approximately 7% are capable of forming algal blooms (red tides) (Sournia 1995); dinoflagellates are the most important group producing toxic and harmful algal blooms (Steidinger 1983, 1993; Anderson 1989... Taxonomic identification revealed 134 species of dinoflagellates in surface waters of the BOB during the observation period (Table 2). Further grouping of these identified species based on their nutritional mode, revealed 40 autotrophic, 50 mixotrophic...

  8. Algal biodiesel production from power plant exhaust and its potential to replace petrodiesel and reduce greenhouse gas emissions

    OpenAIRE

    K. Hundt; B.V. Reddy

    2011-01-01

    The production of biofuels and other products from algae is a technology that is rapidly developing. This paper presents an overview of algae, its benefits over other biofuel sources and the technology involved in producing algal biofuel. The case study in this report looks at the potential of algal biodiesel, produced using power plant exhaust, to replace our current petrodiesel supply and consequently reduce greenhouse gas emissions. The results suggest that using 60% of all coal and gas po...

  9. Dynamics of Bacterial and Fungal Communities during the Outbreak and Decline of an Algal Bloom in a Drinking Water Reservoir

    OpenAIRE

    Haihan Zhang; Jingyu Jia; Shengnan Chen; Tinglin Huang; Yue Wang; Zhenfang Zhao; Ji Feng; Huiyan Hao; Sulin Li; Xinxin Ma

    2018-01-01

    The microbial communities associated with algal blooms play a pivotal role in organic carbon, nitrogen and phosphorus cycling in freshwater ecosystems. However, there have been few studies focused on unveiling the dynamics of bacterial and fungal communities during the outbreak and decline of algal blooms in drinking water reservoirs. To address this issue, the compositions of bacterial and fungal communities were assessed in the Zhoucun drinking water reservoir using 16S rRNA and internal tr...

  10. Application of laser-induced breakdown spectroscopy to the analysis of algal biomass for industrial biotechnology

    Czech Academy of Sciences Publication Activity Database

    Pořízka, P.; Procházka, D.; Pilát, Zdeněk; Krajčarová, L.; Kaiser, J.; Malina, R.; Novotný, J.; Zemánek, Pavel; Ježek, Jan; Šerý, Mojmír; Bernatová, Silvie; Krzyžánek, Vladislav; Hrubanová, Kamila; Novotný, K.; Trtílek, M.; Samek, Ota

    74-75, AUG-SEP (2012), s. 169-176 ISSN 0584-8547 R&D Projects: GA ČR GAP205/11/1687; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : LIBS * double-pulse * water-jet * algal biomass * biotechnology Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.141, year: 2012

  11. Grazer diversity interacts with biogenic habitat heterogeneity to accelerate intertidal algal succession.

    Science.gov (United States)

    Whalen, Matthew A; Aquilino, Kristin M; Stachowicz, John J

    2016-08-01

    Environmental heterogeneity contributes to coexistence by allowing species with different traits to persist when different species perform best at different times or places. This interaction between niche differences and environmental variability may also help explain relationships between biodiversity and ecosystem functioning, but few data are available to rigorously evaluate this hypothesis. We assessed how a biologically relevant aspect of environmental heterogeneity interacts with species diversity to determine ecosystem processes in a natural rocky intertidal community. We used field removals to factorially manipulate biogenic habitat heterogeneity (barnacles, bare rock, and plots that were 50/50 mixes of the two habitat types) and gastropod grazer species richness and then tracked algal community succession and recovery over the course of 1 yr. We found that herbivore diversity, substrate heterogeneity, and their interaction played unique roles in the peak abundance and timing of occurrence of different algal functional groups. Early successional microalgae were most heavily grazed in diverse herbivore assemblages and those with barnacles present, which was likely due to complementary feeding strategies among all three grazers. In contrast, late successional macroalgae were strongly influenced by the presence of a habitat generalist limpet. In this herbivore's absence, heterogeneous habitats (i.e., mixtures of bare rock and barnacles) experienced the greatest algal accumulation, which was partly a result of complementary habitat use by the remaining herbivores. The complex way habitat identity and heterogeneity altered grazer-algal interactions in our study suggests species' differences and environmental heterogeneity both separately and interactively contribute to the relationship between biodiversity and ecosystem functions. © 2016 by the Ecological Society of America.

  12. Hydroclimatic conditions trigger record harmful algal bloom in western Patagonia (summer 2016)

    OpenAIRE

    León-Muñoz, Jorge; Urbina, Mauricio A.; Garreaud, René; Iriarte, José Luis

    2018-01-01

    A harmful algal bloom (HAB) of the raphidophyta alga Pseudochattonella cf. verruculosa during the 2016 austral summer (February-March) killed nearly 12% of the Chilean salmon production, causing the worst mass mortality of fish and shellfish ever recorded in the coastal waters of western Patagonia. The HAB coincided with a strong El Niño event and the positive phase of the Southern Annular Mode that altered the atmospheric circulation in southern South America and the adjacent Pacific Ocean. ...

  13. Food safety: developement of new methods for marine algal toxins detection

    OpenAIRE

    Barreras Garcia, Alvaro

    2013-01-01

    2011/2012 SUMMARY Biotoxins produced by harmful algae during their proliferation can be accumulated by filter feeding organisms, such as bivalve shellfish, within their flesh. Furthermore, these toxins gradually are transferred to the higher trophic levels in the food chain, posing a threat to human health, after consumption of contaminated seafood. Filter-feeding invertebrates are organisms in which the toxin accumulation is a well-known phenomenon, especially during harmful algal...

  14. Effect of algal biofertilizer on yield and protein content of rice

    Energy Technology Data Exchange (ETDEWEB)

    Antarikanonda, P.; Amarit, P.; Chetsumon; Tancharoenrat, P.

    Four strains of nitrogen fixing blue-green algae, namely Anabaena siamensis, Anabaena lutea, Nostoc sp. 46 and Nostoc sp. 79. Mixed cultures were applied as biofertilizers to four paddy soil samples, taken from Rangsit, Khok Sumrong, Sakhon Nakorn and Surin areas. Pots which were arranged in completely randomized design consisted of 3 replications and 2 treatment in each replication. These treatments comprise an unbiofertilizer and a biofertilizer which biofertilizer rate was applied equally at 4 grams of blue green algae per 10 kilograms of soil sample. The results showed that algal biofertilizer enhanced the growth and yield of the rice significantly, which was noticeable in the dry weight of the straw and grain of rice, for all sources of soil. Grain yield of rice in these soils increased form the check of 32.07, 34.87, 8.86 and 21.49 to 53.14, 49.53, 20.02, and 49.60 grams per pot, respectively. The responsiveness of rice which received algal biofertilizer was different. The percentage increase in yield ranged from 42% in Khok Sumrong soil and 66% in Rangsit soil, to 126 and 131% in Sakhon Nakorn and Surin soil, respectively. Significant increase in protein content of rice with the application of algal biofertilizer was from the check of 5.03, 5.14, 6.75 and 5.25 to 6.45, 6.53, 7.80 and 7.11 percent respectively. The difference in plant N-uptake level, after the application algal biofertilizer gave 383.50, 310.00, 222.20 and 480.70 milligrams per pot, respectively.

  15. Algal eating habits of phycologists attending the ISAP Halifax conference and members of the general public

    OpenAIRE

    Edwards, Maeve D.; Holdt, Susan Løvstad; Hynes, Stephen

    2011-01-01

    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 (93%), but few participants ate it more regularly than per month. The general public responses were similar. A probability model tested the likelihood of a participant eating algae. Neither age nor na...

  16. The Upper Eocene crustose coralline algal pavement in the Colli Berici, north-eastern Italy

    OpenAIRE

    Davide Bassi

    2005-01-01

    A crustose coralline algal pavement, identified in Upper Eocene (Priabonian) shallow water, middleramp carbonates in north-eastern Italy (Colli Berici, Southern Alps), represents a rare example of this facies.The crustose pavement consists of a coralline crust bindstone with a wackestone-packstone matrix, and is characterised by the dominance of crustose coralline thalli composed primarily of melobesioids (Lithothamnion and Mesophyllum) and mastophoroids (Spongites, Lithoporella, Neogoniolith...

  17. Sex in murky waters: algal-induced turbidity increases sexual selection in pipefish.

    Science.gov (United States)

    Sundin, Josefin; Aronsen, Tonje; Rosenqvist, Gunilla; Berglund, Anders

    2017-01-01

    Algal-induced turbidity has been shown to alter several important aspects of reproduction and sexual selection. However, while turbidity has been shown to negatively affect reproduction and sexually selected traits in some species, it may instead enhance reproductive success in others, implying that the impact of eutrophication is far more complex than originally believed. In this study, we aimed to provide more insight into these inconsistent findings. We used molecular tools to investigate the impact of algal turbidity on reproductive success and sexual selection on males in controlled laboratory experiments, allowing mate choice, mating competition, and mate encounter rates to affect reproduction. As study species, we used the broad-nosed pipefish, Syngnathus typhle , a species practicing male pregnancy and where we have previously shown that male mate choice is impaired by turbidity. Here, turbidity instead enhanced sexual selection on male size and mating success as well as reproductive success. Effects from mating competition and mate encounter rates may thus override effects from mate choice based on visual cues, producing an overall stronger sexual selection in turbid waters. Hence, seemingly inconsistent effects of turbidity on sexual selection may depend on which mechanisms of sexual selection that have been under study. Algal blooms are becoming increasingly more common due to eutrophication of freshwater and marine environments. The high density of algae lowers water transparency and reduces the possibility for fish and other aquatic animals to perform behaviors dependent on vision. We have previously shown that pipefish are unable to select the best partner in mate choice trials when water transparency was reduced. However, fish might use other senses than vision to compensate for the reduction in water transparency. In this study, we found that when fish were allowed to freely interact, thereby allowing competition between partners and direct contact

  18. Studies on bioaccumulation of 152Eu, 137Cs, 60Co by different algal genera

    International Nuclear Information System (INIS)

    Saha, A.K.; Chakraborty, N.; Pal, R.; Nayak, Dalia; Lahiri, Susanta

    2006-01-01

    In the present paper, the bioaccumulation of a mixture of potentially hazardous, long lived radionuclides 152 Eu, 137 Cs and 60 Co by five algal genera of three different family, viz.: Lyngbya and Phormidium from cyanophyceae; Phizoclonium and Chaetomorpha from chlorophyceae and Catenella from rhodophyceae have been studied. Because of the long half life and high solubility, these radionuclides are considered the most hazardous in the nuclear spent fuel

  19. Preliminary evaluation of an in vivo fluorometer to quantify algal periphyton biomass and community composition

    Science.gov (United States)

    Harris, Theodore D.; Graham, Jennifer L.

    2015-01-01

    The bbe-Moldaenke BenthoTorch (BT) is an in vivo fluorometer designed to quantify algal biomass and community composition in benthic environments. The BT quantifies total algal biomass via chlorophyll a (Chl-a) concentration and may differentiate among cyanobacteria, green algae, and diatoms based on pigment fluorescence. To evaluate how BT measurements of periphytic algal biomass (as Chl-a) compared with an ethanol extraction laboratory analysis, we collected BT- and laboratory-measured Chl-a data from 6 stream sites in the Indian Creek basin, Johnson County, Kansas, during August and September 2012. BT-measured Chl-a concentrations were positively related to laboratory-measured concentrations (R2 = 0.47); sites with abundant filamentous algae had weaker relations (R2 = 0.27). Additionally, on a single sample date, we used the BT to determine periphyton biomass and community composition upstream and downstream from 2 wastewater treatment facilities (WWTF) that discharge into Indian Creek. We found that algal biomass increased immediately downstream from the WWTF discharge then slowly decreased as distance from the WWTF increased. Changes in periphyton community structure also occurred; however, there were discrepancies between BT- and laboratory-measured community composition data. Most notably, cyanobacteria were present at all sites based on BT measurements but were present at only one site based on laboratory-analyzed samples. Overall, we found that the BT compared reasonably well with laboratory methods for relative patterns in Chl-a but not as well with absolute Chl-aconcentrations. Future studies need to test the BT over a wider range of Chl-aconcentrations, in colored waters, and across various periphyton assemblages.

  20. 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 (sewage outfall impact. Ulva spp. did not reflect the typical pattern observed for other sewage pollution areas. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. General Aviation Citizen Science Pilot Study to Help Tackle Remote Sensing of Harmful Algal Blooms (HABs)

    Science.gov (United States)

    Ansari, R.

    2017-12-01

    Aerial remote sensing conducted by volunteer pilots acting as citizen scientists is providing high-quality data to help understand reasons behind outbreaks of toxic algal blooms in nation's waterways and coastlines. The toxic water can be detrimental to national economy, human health, clean drinking water, fishing industry, and water sports. We will show how general aviation pilots around the country are contributing to this NASA citizen science initiative.

  2. Are algal genes in nonphotosynthetic protists evidence of historical plastid endosymbioses?

    Directory of Open Access Journals (Sweden)

    Tian Jing

    2009-10-01

    Full Text Available Abstract Background How photosynthetic organelles, or plastids, were acquired by diverse eukaryotes is among the most hotly debated topics in broad scale eukaryotic evolution. The history of plastid endosymbioses commonly is interpreted under the "chromalveolate" hypothesis, which requires numerous plastid losses from certain heterotrophic groups that now are entirely aplastidic. In this context, discoveries of putatively algal genes in plastid-lacking protists have been cited as evidence of gene transfer from a photosynthetic endosymbiont that subsequently was lost completely. Here we examine this evidence, as it pertains to the chromalveolate hypothesis, through genome-level statistical analyses of similarity scores from queries with two diatoms, Phaeodactylum tricornutum and Thalassiosira pseudonana, and two aplastidic sister taxa, Phytophthora ramorum and P. sojae. Results Contingency tests of specific predictions of the chromalveolate model find no evidence for an unusual red algal contribution to Phytophthora genomes, nor that putative cyanobacterial sequences that are present entered these genomes through a red algal endosymbiosis. Examination of genes unrelated to plastid function provide extraordinarily significant support for both of these predictions in diatoms, the control group where a red endosymbiosis is known to have occurred, but none of that support is present in genes specifically conserved between diatoms and oomycetes. In addition, we uncovered a strong association between overall sequence similarities among taxa and relative sizes of genomic data sets in numbers of genes. Conclusion Signal from "algal" genes in oomycete genomes is inconsistent with the chromalveolate hypothesis, and better explained by alternative models of sequence and genome evolution. Combined with the numerous sources of intragenomic phylogenetic conflict characterized previously, our results underscore the potential to be mislead by a posteriori

  3. Advances in algal-prokaryotic wastewater treatment: A review of nitrogen transformations, reactor configurations and molecular tools.

    Science.gov (United States)

    Wang, Meng; Keeley, Ryan; Zalivina, Nadezhda; Halfhide, Trina; Scott, Kathleen; Zhang, Qiong; van der Steen, Peter; Ergas, Sarina J

    2018-07-01

    The synergistic activity of algae and prokaryotic microorganisms can be used to improve the efficiency of biological wastewater treatment, particularly with regards to nitrogen removal. For example, algae can provide oxygen through photosynthesis needed for aerobic degradation of organic carbon and nitrification and harvested algal-prokaryotic biomass can be used to produce high value chemicals or biogas. Algal-prokaryotic consortia have been used to treat wastewater in different types of reactors, including waste stabilization ponds, high rate algal ponds and closed photobioreactors. This review addresses the current literature and identifies research gaps related to the following topics: 1) the complex interactions between algae and prokaryotes in wastewater treatment; 2) advances in bioreactor technologies that can achieve high nitrogen removal efficiencies in small reactor volumes, such as algal-prokaryotic biofilm reactors and enhanced algal-prokaryotic treatment systems (EAPS); 3) molecular tools that have expanded our understanding of the activities of algal and prokaryotic communities in wastewater treatment processes. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Analysis of algal bloom risk with uncertainties in lakes by integrating self-organizing map and fuzzy information theory.

    Science.gov (United States)

    Chen, Qiuwen; Rui, Han; Li, Weifeng; Zhang, Yanhui

    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. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Amperometric screen-printed algal biosensor with flow injection analysis system for detection of environmental toxic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Shitanda, Isao [Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan)], E-mail: shitanda@rs.noda.tus.ac.jp; Takamatsu, Satoshi; Watanabe, Kunihiro; Itagaki, Masayuki [Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan)

    2009-08-30

    A screen-printed algal biosensor was fabricated for evaluation of toxicity of chemicals. An algal ink was prepared by mixing unicellular microalga Chlorella vulgaris cells, carbon nanotubes and sodium alginate solution. The algal ink was immobilized directly on a screen-printed carbon electrode surface using screen-printing technique. Photosynthetically generated oxygen of the immobilized algae was monitored amperometically. Responses of the algal biosensor to four toxic compounds, 6-chloro-N-ethyl-N-isopropyl-1,3,5-triazine-2,4-diamine (atrazine) and 3-(3,4-dichlorophenyl)-1,1-diethylurea (DCMU) were evaluated as inhibition ratios of the reduction current. The concentrations that gave 50% inhibition of the oxygen reduction current (IC{sup '}{sub 50}) for atrazine and DCMU were 12 and 1 {mu}mol dm{sup -3}, respectively. In comparison with the conventional algal biosensors, in which the algal cells were entrapped in an alginate gel and immobilized on the surface of a transparent indium tin oxide electrode, the present sensor is much smaller and less expensive, with the shorter assay time.

  6. Innovation in emerging energy technologies: A case study analysis to inform the path forward for algal biofuels

    International Nuclear Information System (INIS)

    Haase, Rachel; Bielicki, Jeffrey; Kuzma, Jennifer

    2013-01-01

    Algal biofuel is an emerging energy source that has the potential to improve upon the environmental benefits realized by conventional biofuels and contribute to the biofuels mandate set by the Renewable Fuel Standard (RFS). While there has been much research into producing fuel from algae, a commercial-scale facility has not yet been built. We examine two case studies of energy technology innovation in the United States, first generation biodiesel and solar photovoltaics (PV), using the technological innovation system (TIS) framework to provide lessons and inform the path forward for commercializing algal biofuel. We identify five event types that have been the most influential to these innovation processes: changing expectations, technology development, demonstration projects, policy targets, and government subsidies. Some algal biofuel demonstration projects have occurred, but despite falling under the mandates set forth in the RFS (a policy target), algal biofuels do not currently receive production subsidies. The main finding from the case study analysis is that government interventions have significantly influenced the innovation processes of first generation biodiesel and solar PV and will likely be key factors in the commercialization of algal biofuel. - Highlights: • Two energy technology case studies were analyzed with a TIS framework. • Major drivers in the innovation process were identified in each case. • Government interventions were key factors for both. • The one identified key driver algal biofuel is lacking is federal subsidies. • All components of the TIS framework deserve attention in promoting innovation

  7. Amperometric screen-printed algal biosensor with flow injection analysis system for detection of environmental toxic compounds

    International Nuclear Information System (INIS)

    Shitanda, Isao; Takamatsu, Satoshi; Watanabe, Kunihiro; Itagaki, Masayuki

    2009-01-01

    A screen-printed algal biosensor was fabricated for evaluation of toxicity of chemicals. An algal ink was prepared by mixing unicellular microalga Chlorella vulgaris cells, carbon nanotubes and sodium alginate solution. The algal ink was immobilized directly on a screen-printed carbon electrode surface using screen-printing technique. Photosynthetically generated oxygen of the immobilized algae was monitored amperometically. Responses of the algal biosensor to four toxic compounds, 6-chloro-N-ethyl-N-isopropyl-1,3,5-triazine-2,4-diamine (atrazine) and 3-(3,4-dichlorophenyl)-1,1-diethylurea (DCMU) were evaluated as inhibition ratios of the reduction current. The concentrations that gave 50% inhibition of the oxygen reduction current (IC ' 50 ) for atrazine and DCMU were 12 and 1 μmol dm -3 , respectively. In comparison with the conventional algal biosensors, in which the algal cells were entrapped in an alginate gel and immobilized on the surface of a transparent indium tin oxide electrode, the present sensor is much smaller and less expensive, with the shorter assay time.

  8. Coupled nutrient removal and biomass production with mixed algal culture: impact of biotic and abiotic factors.

    Science.gov (United States)

    Su, Yanyan; Mennerich, Artur; Urban, Brigitte

    2012-08-01

    The influence of biotic (algal inoculum concentration) and abiotic factors (illumination cycle, mixing velocity and nutrient strength) on the treatment efficiency, biomass generation and settleability were investigated with selected mixed algal culture. Dark condition led to poor nutrient removal efficiency. No significant difference in the N, P removal and biomass settleability between continuous and alternating illumination was observed, but a higher biomass generation capability for the continuous illumination was obtained. Different mixing velocity led to similar phosphorus removal efficiencies (above 98%) with different retention times. The reactor with 300 rpm mixing velocity had the best N removal capability. For the low strength wastewater, the N rates were 5.4±0.2, 9.1±0.3 and 10.8±0.3 mg/l/d and P removal rates were 0.57±0.03, 0.56±0.03 and 0.72±0.05 mg/l/d for reactors with the algal inoculum concentration of 0.2, 0.5 and 0.8 g/l, respectively. Low nutrient removal efficiency and poor biomass settleability were obtained for high strength wastewater. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Determination of the algal growth-limiting nutrients in strip mine ponds

    International Nuclear Information System (INIS)

    Bucknavage, M.J.; Aharrah, E.C.

    1984-01-01

    Using both a test organism, Ankistrodesmus falcatus, and natural phytoplankton, the Printz Algal Assay Bottle Test was used to determine the algal growth limiting nutrients in two strip mine ponds. Nitrogen, phosphorus, and iron were investigated, singly and in combination, as possible limiting nutrients. A synthetic chelator, Na 2 EDTA, was also used in the assay to test for the presence of metal toxicants and/or trace metal limitation. Because bacteria have a major influence on water chemistry, a separate assay incorporating the natural bacteria population was performed. In both ponds, assay results using test alga indicate phosphorus to be the primary limiting nutrient and nitrogen as a secondary factor. The presence of EDTA in combination with phosphate containing treatment promoted a higher algal concentration in both ponds. Iron was determined to be a secondary limiting nutrient in only one of the ponds. Natural phytoplankton of the two ponds responded in a similar manner to nutrient increases. Only one pond had the same results produced by both assays. Nutrient availability was influenced by the presence of bacteria in one pond but not in the other

  10. Application of laser-induced breakdown spectroscopy to the analysis of algal biomass for industrial biotechnology

    International Nuclear Information System (INIS)

    Pořízka, P.; Prochazka, D.; Pilát, Z.; Krajcarová, L.; Kaiser, J.; Malina, R.; Novotný, J.; Zemánek, P.; Ježek, J.; Šerý, M.; Bernatová, S.; Krzyžánek, V.; Dobranská, K.; Novotný, K.; Trtílek, M.; Samek, O.

    2012-01-01

    We report on the application of laser-induced breakdown spectroscopy (LIBS) to the determination of elements distinctive in terms of their biological significance (such as potassium, magnesium, calcium, and sodium) and to the monitoring of accumulation of potentially toxic heavy metal ions in living microorganisms (algae), in order to trace e.g. the influence of environmental exposure and other cultivation and biological factors having an impact on them. Algae cells were suspended in liquid media or presented in a form of adherent cell mass on a surface (biofilm) and, consequently, characterized using their spectra. In our feasibility study we used three different experimental arrangements employing double-pulse LIBS technique in order to improve on analytical selectivity and sensitivity for potential industrial biotechnology applications, e.g. for monitoring of mass production of commercial biofuels, utilization in the food industry and control of the removal of heavy metal ions from industrial waste waters. - Highlights: ► We realized laser-induced breakdown spectroscopy (LIBS) analysis of algal biomass. ► We used water jet setup, bulk liquid arrangement and algal biofilms. ► LIBS analysis of macro- and micro-element concentrations in algae was shown. ► LIBS can be of assistance in research of sustainable biofuel generation. ► LIBS can be used in research of algal food applications and bioremediation.

  11. Application of laser-induced breakdown spectroscopy to the analysis of algal biomass for industrial biotechnology

    Energy Technology Data Exchange (ETDEWEB)

    Porizka, P.; Prochazka, D. [X-ray micro CT and nano CT research group, CEITEC-Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, 616 00 Brno (Czech Republic); Pilat, Z. [Institute of Scientific Instruments of the ASCR v.v.i., Academy of Sciences of the Czech Republic, Kralovopolska 147, Brno 61669 (Czech Republic); Krajcarova, L. [Department of Chemistry, Faculty of Sciences, Masaryk University, Kotlarska 2, Brno 611 37 (Czech Republic); Kaiser, J., E-mail: kaiser@fme.vutbr.cz [X-ray micro CT and nano CT research group, CEITEC-Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, 616 00 Brno (Czech Republic); Malina, R.; Novotny, J. [X-ray micro CT and nano CT research group, CEITEC-Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, 616 00 Brno (Czech Republic); Zemanek, P.; Jezek, J.; Sery, M.; Bernatova, S.; Krzyzanek, V.; Dobranska, K. [Institute of Scientific Instruments of the ASCR v.v.i., Academy of Sciences of the Czech Republic, Kralovopolska 147, Brno 61669 (Czech Republic); Novotny, K. [Department of Chemistry, Faculty of Sciences, Masaryk University, Kotlarska 2, Brno 611 37 (Czech Republic); Trtilek, M. [Photon Systems Instruments, Drasov 470, 664 24 Drasov (Czech Republic); Samek, O. [Institute of Scientific Instruments of the ASCR v.v.i., Academy of Sciences of the Czech Republic, Kralovopolska 147, Brno 61669 (Czech Republic)

    2012-08-15

    We report on the application of laser-induced breakdown spectroscopy (LIBS) to the determination of elements distinctive in terms of their biological significance (such as potassium, magnesium, calcium, and sodium) and to the monitoring of accumulation of potentially toxic heavy metal ions in living microorganisms (algae), in order to trace e.g. the influence of environmental exposure and other cultivation and biological factors having an impact on them. Algae cells were suspended in liquid media or presented in a form of adherent cell mass on a surface (biofilm) and, consequently, characterized using their spectra. In our feasibility study we used three different experimental arrangements employing double-pulse LIBS technique in order to improve on analytical selectivity and sensitivity for potential industrial biotechnology applications, e.g. for monitoring of mass production of commercial biofuels, utilization in the food industry and control of the removal of heavy metal ions from industrial waste waters. - Highlights: Black-Right-Pointing-Pointer We realized laser-induced breakdown spectroscopy (LIBS) analysis of algal biomass. Black-Right-Pointing-Pointer We used water jet setup, bulk liquid arrangement and algal biofilms. Black-Right-Pointing-Pointer LIBS analysis of macro- and micro-element concentrations in algae was shown. Black-Right-Pointing-Pointer LIBS can be of assistance in research of sustainable biofuel generation. Black-Right-Pointing-Pointer LIBS can be used in research of algal food applications and bioremediation.

  12. ENSAMBLES ALGALES EN UN MICROECOSISTEMA NATURAL DE LA PLANTA CARNÍVORA TROPICAL UTRICULARIA FOLIOSA L.

    Directory of Open Access Journals (Sweden)

    Diaz-Olarte J

    2009-12-01

    Full Text Available Se estudió la abundancia y la composición de los ensambles algales asociadosa Utricularia foliosa en siete plantas localizadas en la quebrada Yahuarcaca(Amazonas - Colombia. Los objetivos fueron determinar los ensambles algalesdentro del microecosistema de U. foliosa y sus variaciones de acuerdo con lascondiciones de los nutrientes. Los cambios en la riqueza y la abundancia de losensambles estuvieron infl uenciados por las fl uctuaciones en el nivel del agua y laconcentración de PO . En los ensambles de aguas abiertas se observó la dominanciade cianobacterias heterocitadas, diatomeas y organismos de gran capacidad móvilcomo euglenófi tos. Las condiciones del microambiente creadas por U. foliosacontrolan la diversidad y las densidades algales. Esto hace muy posible que U.foliosa genere condiciones fi siológicas óptimas que favorecen una alta riquezade especies tico-epífi tas como desmidias y diatomeas perifíticas. Se forma así unmicroecosistema del cual obtiene más benefi cios de la comunidad que de la mismaestrategia de la carnivoría desarrollada por U. foliosa. Se analiza además la relaciónentre la composición algal y las variables físicas y químicas por medio de un análisisde correspondencia canónica distendida.

  13. Selective recovery of gold and other metal ions from an algal biomass

    Energy Technology Data Exchange (ETDEWEB)

    Darnall, D.W.; Greene, B.; Henzl, M.T.; Hosea, J.M.; McPherson, R.A.; Sneddon, J.; Alexander, M.D.

    1986-02-01

    The authors observed that the pH dependence of the binding of Au/sup 3 +/, Ag/sup +/, and Hg/sup 2 +/ to the algae Chlorella vulgaris is different than the binding of other metal ions. Between pH 5 and 7, a variety of metal ions bind strongly to the cell surface. Most of these algal-bound metal ions can be selectively desorbed by lowering the pH to 2; however, Au/sup 3 +/, Hg/sup 2 +/, and Ag/sup +/ are all bound strongly at pH 2. Addition of a strong ligand at different pHs is required to elute these ions from the algal surface. Algal-bound gold and mercury can be selectively eluted by using mercaptoethanol. An elution scheme is demonstrated for the binding and selective recovery of Cu/sup 2 +/, Zn/sup 2 +/, Au/sup 3 +/, and Hg/sup 2 +/ from an equimolar mixture. 20 references, 2 figures.

  14. Coralline algal physiology is more adversely affected by elevated temperature than reduced pH.

    Science.gov (United States)

    Vásquez-Elizondo, Román Manuel; Enríquez, Susana

    2016-01-07

    In this study we analyzed the physiological responses of coralline algae to ocean acidification (OA) and global warming, by exposing algal thalli of three species with contrasting photobiology and growth-form to reduced pH and elevated temperature. The analysis aimed to discern between direct and combined effects, while elucidating the role of light and photosynthesis inhibition in this response. We demonstrate the high sensitivity of coralline algae to photodamage under elevated temperature and its severe consequences on thallus photosynthesis and calcification rates. Moderate levels of light-stress, however, were maintained under reduced pH, resulting in no impact on algal photosynthesis, although moderate adverse effects on calcification rates were still observed. Accordingly, our results support the conclusion that global warming is a stronger threat to algal performance than OA, in particular in highly illuminated habitats such as coral reefs. We provide in this study a quantitative physiological model for the estimation of the impact of thermal-stress on coralline carbonate production, useful to foresee the impact of global warming on coralline contribution to reef carbon budgets, reef cementation, coral recruitment and the maintenance of reef biodiversity. This model, however, cannot yet account for the moderate physiological impact of low pH on coralline calcification.

  15. Characterisation of transparent exopolymer particles (TEP) produced during algal bloom: A membrane treatment perspective

    KAUST Repository

    Villacorte, Loreen O.

    2013-01-01

    Algal blooms are currently a major concern of the membrane industry as it generates massive concentrations of organic matter (e.g. transparent exopolymer particles [TEP]), which can adversely affect the operation of membrane filtration systems. The goal of this study is to understand the production, composition and membrane rejection of these organic materials using different characterisation techniques. Two common species of bloom-forming freshwater and marine algae were cultivated in batch cultures for 30days and the productions of TEP and other organic matter were monitored at different growth phases. TEP production of the marine diatom, Chaetoceros affinis, produced 6-9 times more TEP than the freshwater blue-green algae, Microcystis. The organic substances produced by both algal species were dominated by biopolymeric substances such as polysaccharides (45-64%) and proteins (2-17%) while the remaining fraction comprises of low molecular weight refractory (humic-like) and/ or biogenic organic substances. MF/UF membranes mainly rejected the biopolymers but not the low molecular weight organic materials. MF membranes (0.1-0.4 lm) rejected 42-56% of biopolymers, while UF membranes (10-100 kDa) rejected 65-95% of these materials. Further analysis of rejected organic materials on the surface of the membranes revealed that polysac-charides and proteins are likely responsible for the fouling of MF/UF systems during an algal bloom situation. © 2013 Desalination Publications.

  16. Investigation of animal and algal bioassays for reliable saxitoxin ecotoxicity and cytotoxicity risk evaluation.

    Science.gov (United States)

    Perreault, François; Matias, Marcelo Seleme; Melegari, Silvia Pedroso; Pinto, Catia Regina Silva de Carvalho; Creppy, Edmond Ekué; Popovic, Radovan; Matias, William Gerson

    2011-05-01

    Contamination of water bodies by saxitoxin can result in various toxic effects in aquatic organisms. Saxitoxin contamination has also been shown to be a threat to human health in several reported cases, even resulting in death. In this study, we evaluated the sensitivity of animal (Neuro-2A) and algal (Chlamydomonas reinhardtii) bioassays to saxitoxin effect. Neuro-2A cells were found to be sensitive to saxitoxin, as shown by a 24 h EC50 value of 1.5 nM, which was obtained using a cell viability assay. Conversely, no saxitoxin effect was found in any of the algal biomarkers evaluated, for the concentration range tested (2-128 nM). These results indicate that saxitoxin may induce toxic effects in animal and human populations at concentrations where phytoplankton communities are not affected. Therefore, when evaluating STX risk of toxicity, algal bioassays do not appear to be reliable indicators and should always be conducted in combination with animal bioassays. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Relationships between primary production and irradiance in coral reef algal communities

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    Shallow water algal turf communities are the major primary producers on coral reefs. High rates of primary production are maintained despite extremely high light intensities and exposure to ultraviolet wavelengths. The relationships between the light intensity and primary production in these assemblages are typical of algae adapted to a high light environment [low α (initial slope), high I/sub k/ (saturating light intensity), and high I/sub c/ (compensation point light intensity)]. Seasonal variations in algal standing crop due to herbivory and daylength result in some characteristic photoadaptive changes in α I/sub k/, and I/sub c/ and changes in Pnet/sub max/ rates (maximum net photosynthetic rate achieved at light saturation) on both a chlorophyll α and an areal basis. Exposure to UV wavelength results in significantly higher respiration rates but no changes in α, Pnet/sub max/, or I/sub k/, when compared with these parameters for the same algal communities incubated at the same light intensities without UV wavelengths. The apparent lack of photoinhibition in these algae allows calculation of the daily integrated production from the P vs. I parameters. This integrated production is highest in July (3.1 +/- 0.2 g C m -2 d -1 ) and is reduced by 30% from this maximum in December (2.1 +/- 0.1 g C m -2 d -1 )

  18. Mini-review: high rate algal ponds, flexible systems for sustainable wastewater treatment.

    Science.gov (United States)

    Young, P; Taylor, M; Fallowfield, H J

    2017-06-01

    Over the last 20 years, there has been a growing requirement by governments around the world for organisations to adopt more sustainable practices. Wastewater treatment is no exception, with many currently used systems requiring large capital investment, land area and power consumption. High rate algal ponds offer a sustainable, efficient and lower cost option to the systems currently in use. They are shallow, mixed lagoon based systems, which aim to maximise wastewater treatment by creating optimal conditions for algal growth and oxygen production-the key processes which remove nitrogen and organic waste in HRAP systems. This design means they can treat wastewater to an acceptable quality within a fifth of time of other lagoon systems while using 50% less surface area. This smaller land requirement decreases both the construction costs and evaporative water losses, making larger volumes of treated water available for beneficial reuse. They are ideal for rural, peri-urban and remote communities as they require minimum power and little on-site management. This review will address the history of and current trends in high rate algal pond development and application; a comparison of their performance with other systems when treating various wastewaters; and discuss their potential for production of added-value products. Finally, the review will consider areas requiring further research.

  19. Identification of an algal carbon fixation-enhancing factor extracted from Paramecium bursaria.

    Science.gov (United States)

    Kato, Yutaka; Imamura, Nobutaka

    2011-01-01

    The green ciliate Paramecium bursaria contains several hundred symbiotic Chlorella species. We previously reported that symbiotic algal carbon fixation is enhanced by P. bursaria extracts and that the enhancing factor is a heat-stable, low-molecular-weight, water-soluble compound. To identify the factor, further experiments were carried out. The enhancing activity remained even when organic compounds in the extract were completely combusted at 700 degrees C, suggesting that the factor is an inorganic substance. Measurement of the major cations, K+, Ca2+, and Mg2+, by an electrode and titration of the extract resulted in concentrations of 0.90 mM, 0.55 mM, and 0.21 mM, respectively. To evaluate the effect of these cations, a mixture of the cations at the measured concentrations was prepared, and symbiotic algal carbon fixation was measured in the solution. The results demonstrated that the fixation was enhanced to the same extent as with the P. bursaria extract, and thus this mixture of K+, Ca2+, and Mg2+ was concluded to be the carbon fixation-enhancing factor. There was no effect of the cation mixture on free-living C. vulgaris. Comparison of the cation concentrations of nonsymbiotic and symbiotic Paramecium extracts revealed that the concentrations of K+ and Mg2+ in nonsymbiotic Paramecium extracts were too low to enhance symbiotic algal carbon fixation, suggesting that symbiotic P. bursaria provide suitable cation conditions for photosynthesis to its symbiotic Chlorella.

  20. Printing of cotton with eco-friendly, red algal pigment from Gracilaria sp.

    Science.gov (United States)

    Moldovan, S.; Ferrandiz, M.; Franco, E.; Mira, E.; Capablanca, L.; Bonet, Mª

    2017-10-01

    Natural dyes represent an emerging trend in the textile industry and eco-fashion due to the increasing awareness of the sustainability concept, which must be applied to the surrounding environment. In the light of the stated problem, the search for alternative sources of dyes, revealed the new, eco-friendly, biodegradable, non-carcinogenic and sustainable colorant matter, the algal biomass. In the present work, the suitability and viability of printing cotton fabrics with pigments obtained from the red macroalgae Gracilaria sp., has been investigated. For this aim, phycoerythrin, the red pigment, was extracted from fresh algal biomass, and used in a laboratory pigment-printing process, employing a natural and synthetic printing paste, for process efficiency comparison. The color values and the rubbing and laundering fastness of the printed substrates were evaluated. Results show that a light pink color can be obtained when applying both tested printing processes, and in terms of color fastness, both printing pastes show good behavior. In conclusion, the algal pigments show a high printing capacity on cotton substrates, either when employing the synthetic conventional paste and; moreover, when applying the more sustainable and eco-friendly natural paste.

  1. Controlling silver nanoparticle exposure in algal toxicity testing - A matter of timing

    DEFF Research Database (Denmark)

    Sørensen, Sara Nørgaard; Baun, Anders

    2015-01-01

    ) in a standard algal growth inhibition test (ISO 8692:2004) for 48 h and a short-term (2 h) 14C-assimilation test. For AgNO3, similar responses were obtained in the two tests, whereas freshly prepared suspensions of citrate stabilized AgNPs were less toxic in the 2-h tests compared to the 48-h tests. The 2-h...... test was found applicable for dissolved silver, but yielded non-monotonous concentration–response relationships and poor reproducibility for freshly prepared AgNP suspensions. However, when aging AgNPs in algal medium 24 h prior to testing, clear concentration–response patterns emerged...... and reproducibility increased. Prolonged aging to 48 h increased toxicity in the 2-h tests whereas aging beyond 48 h reduced toxicity. Our results demonstrate that the outcome of algal toxicity testing of AgNPs is highly influenced not only by the test duration, but also by the time passed from the moment Ag...

  2. Assessment of harmful algal species using different approaches: the case study of the Sardinian coasts

    Directory of Open Access Journals (Sweden)

    C.T. Satta

    2014-04-01

    Full Text Available The presence and distribution of harmful algal species were investigated along the coasts of Sardinia in the summer of 2012. Fourteen potentially noxious taxa were identified at 74 beaches. The majority of the recovered taxa were potentially toxic and/or high biomass producers. Alexandrium taylorii, Gymnodinium instriatum, and Ostreopsis cf. ovata were the most frequent and abundant taxa, although Barrufeta bravensis reached the highest density (4.4 × 106 cells L−1. Barrufeta bravensis, A. taylorii, and G. instriatum were responsible for intense water discoloration at two of the beaches sampled. Polymerase chain reaction (PCR analyses supported the identification of several taxa and decisively identified B. bravensis. PCR assays increased the information available on the species distributions. The locations studied were heterogeneous in their prevailing environmental conditions and their morphodynamic profiles. Statistical analyses indicated that the distributions of harmful algal species correlated with gravel and medium-fine sand substrata. These data provide substantial knowledge on the distributions of harmful algal species on beaches, which have been poorly studied on a global scale. The apparent relationship between noxious species and grain size suggests that vegetative cells may be recruited from cyst beds in beach sediments.

  3. Investigation of severe UF membrane fouling induced by three marine algal species

    KAUST Repository

    Merle, Tony

    2016-02-06

    Reducing membrane fouling caused by seawater algal bloom is a challenge for regions of the world where most of their freshwater is produced by seawater desalination. This study aims to compare ultrafiltration (UF) fouling potential of three ubiquitous marine algal species cultures (i.e., Skeletonena costatum-SKC, Tetraselmis sp.-TET, and Hymenomonas sp.-HYM) sampled at different phases of growth. Results showed that flux reduction and irreversible fouling were more severe during the decline phase as compared to the exponential phase, for all species. SKC and TET were responsible for substantial irreversible fouling but their impact was significantly lower than HYM. The development of a transparent gel layer surrounding the cell during the HYM growth and accumulating in water is certainly responsible for the more severe observed fouling. Chemical backwash with a standard chlorine solution did not recover any membrane permeability. For TET and HYM, the Hydraulically Irreversible Fouling Index (HIFI) was correlated to their biopolymer content but this correlation is specific for each species. Solution pre-filtration through a 1.2 μm membrane proved that cells and particulate algal organic matter (p-AOM) considerably contribute to fouling, especially for HYM for which the HIFI was reduced by a factor of 82.3.

  4. Coralline algal physiology is more adversely affected by elevated temperature than reduced pH

    Science.gov (United States)

    Vásquez-Elizondo, Román Manuel; Enríquez, Susana

    2016-01-01

    In this study we analyzed the physiological responses of coralline algae to ocean acidification (OA) and global warming, by exposing algal thalli of three species with contrasting photobiology and growth-form to reduced pH and elevated temperature. The analysis aimed to discern between direct and combined effects, while elucidating the role of light and photosynthesis inhibition in this response. We demonstrate the high sensitivity of coralline algae to photodamage under elevated temperature and its severe consequences on thallus photosynthesis and calcification rates. Moderate levels of light-stress, however, were maintained under reduced pH, resulting in no impact on algal photosynthesis, although moderate adverse effects on calcification rates were still observed. Accordingly, our results support the conclusion that global warming is a stronger threat to algal performance than OA, in particular in highly illuminated habitats such as coral reefs. We provide in this study a quantitative physiological model for the estimation of the impact of thermal-stress on coralline carbonate production, useful to foresee the impact of global warming on coralline contribution to reef carbon budgets, reef cementation, coral recruitment and the maintenance of reef biodiversity. This model, however, cannot yet account for the moderate physiological impact of low pH on coralline calcification.

  5. First-principles flocculation as the key to low energy algal biofuels processing.

    Energy Technology Data Exchange (ETDEWEB)

    Hewson, John C.; Wyatt, Nicholas B.; Pierce, Flint; Brady, Patrick Vane; Dwyer, Brian P.; Grillet, Anne; Hankins, Matthew G; Hughes, Lindsey Gloe; Lechman, Jeremy B.; Mondy, Lisa Ann; Murton, Jaclyn K.; O' Hern, Timothy J; Parchert, Kylea Joy; Pohl, Phillip Isabio; Williams, Cecelia Victoria; Zhang, Xuezhi; Hu, Qiang; Amendola, Pasquale; Reynoso, Monica; Sommerfeld, Milton

    2012-09-01

    This document summarizes a three year Laboratory Directed Research and Development (LDRD) program effort to improve our understanding of algal flocculation with a key to overcoming harvesting as a techno-economic barrier to algal biofuels. Flocculation is limited by the concentrations of deprotonated functional groups on the algal cell surface. Favorable charged groups on the surfaces of precipitates that form in solution and the interaction of both with ions in the water can favor flocculation. Measurements of algae cell-surface functional groups are reported and related to the quantity of flocculant required. Deprotonation of surface groups and complexation of surface groups with ions from the growth media are predicted in the context of PHREEQC. The understanding of surface chemistry is linked to boundaries of effective flocculation. We show that the phase-space of effective flocculation can be expanded by more frequent alga-alga or floc-floc collisions. The collision frequency is dependent on the floc structure, described in the fractal sense. The fractal floc structure is shown to depend on the rate of shear mixing. We present both experimental measurements of the floc structure variation and simulations using LAMMPS (Large-scale Atomic/Molecular Massively Parallel Simulator). Both show a densification of the flocs with increasing shear. The LAMMPS results show a combined change in the fractal dimension and a change in the coordination number leading to stronger flocs.

  6. The removal of uranium from mining waste water using algal/microbial biomass

    International Nuclear Information System (INIS)

    Kalin, Margarete; Wheeler, W.N.; Meinrath, G.

    2004-01-01

    We describe a three step process for the removal of uranium (U) from dilute waste waters. Step one involves the sequestration of U on, in, and around aquatic plants such as algae. Cell wall ligands efficiently remove U(VI) from waste water. Growing algae continuously renew the cellular surface area. Step 2 is the removal of U-algal particulates from the water column to the sediments. Step 3 involves reducing U(VI) to U(IV) and transforming the ions into stable precipitates in the sediments. The algal cells provide organic carbon and other nutrients to heterotrophic microbial consortia to maintain the low E H , within which the U is transformed. Among the microorganisms, algae are of predominant interest for the ecological engineer because of their ability to sequester U and because some algae can live under many extreme environments, often in abundance. Algae grow in a wide spectrum of water qualities, from alkaline environments (Chara, Nitella) to acidic mine drainage waste waters (Mougeotia, Ulothrix). If they could be induced to grow in waste waters, they would provide a simple, long-term means to remove U and other radionuclides from U mining effluents. This paper reviews the literature on algal and microbial adsorption, reduction, and transformation of U in waste streams, wetlands, lakes and oceans

  7. Coralline algal barium as indicator for 20th century northwestern North Atlantic surface ocean freshwater variability.

    Science.gov (United States)

    Hetzinger, S; Halfar, J; Zack, T; Mecking, J V; Kunz, B E; Jacob, D E; Adey, W H

    2013-01-01

    During the past decades climate and freshwater dynamics in the northwestern North Atlantic have undergone major changes. Large-scale freshening episodes, related to polar freshwater pulses, have had a strong influence on ocean variability in this climatically important region. However, little is known about variability before 1950, mainly due to the lack of long-term high-resolution marine proxy archives. Here we present the first multidecadal-length records of annually resolved Ba/Ca variations from Northwest Atlantic coralline algae. We observe positive relationships between algal Ba/Ca ratios from two Newfoundland sites and salinity observations back to 1950. Both records capture episodical multi-year freshening events during the 20th century. Variability in algal Ba/Ca is sensitive to freshwater-induced changes in upper ocean stratification, which affect the transport of cold, Ba-enriched deep waters onto the shelf (highly stratified equals less Ba/Ca). Algal Ba/Ca ratios therefore may serve as a new resource for reconstructing past surface ocean freshwater changes.

  8. An algal model for predicting attainment of tiered biological criteria of Maine's streams and rivers

    Science.gov (United States)

    Danielson, Thomas J.; Loftin, Cyndy; Tsomides, Leonidas; DiFranco, Jeanne L.; Connors, Beth; Courtemanch, David L.; Drummond, Francis; Davies, Susan

    2012-01-01

    State water-quality professionals developing new biological assessment methods often have difficulty relating assessment results to narrative criteria in water-quality standards. An alternative to selecting index thresholds arbitrarily is to include the Biological Condition Gradient (BCG) in the development of the assessment method. The BCG describes tiers of biological community condition to help identify and communicate the position of a water body along a gradient of water quality ranging from natural to degraded. Although originally developed for fish and macroinvertebrate communities of streams and rivers, the BCG is easily adapted to other habitats and taxonomic groups. We developed a discriminant analysis model with stream algal data to predict attainment of tiered aquatic-life uses in Maine's water-quality standards. We modified the BCG framework for Maine stream algae, related the BCG tiers to Maine's tiered aquatic-life uses, and identified appropriate algal metrics for describing BCG tiers. Using a modified Delphi method, 5 aquatic biologists independently evaluated algal community metrics for 230 samples from streams and rivers across the state and assigned a BCG tier (1–6) and Maine water quality class (AA/A, B, C, nonattainment of any class) to each sample. We used minimally disturbed reference sites to approximate natural conditions (Tier 1). Biologist class assignments were unanimous for 53% of samples, and 42% of samples differed by 1 class. The biologists debated and developed consensus class assignments. A linear discriminant model built to replicate a priori class assignments correctly classified 95% of 150 samples in the model training set and 91% of 80 samples in the model validation set. Locally derived metrics based on BCG taxon tolerance groupings (e.g., sensitive, intermediate, tolerant) were more effective than were metrics developed in other regions. Adding the algal discriminant model to Maine's existing macroinvertebrate discriminant

  9. Ecological and geographical characteristics of algal communities on gastropod shells of the river Uzh

    Directory of Open Access Journals (Sweden)

    N. M. Korniichuk

    2017-07-01

    Full Text Available Freshwater molluscs serve as test objects in the ecological monitoring of the environment, because they are able to extract in indicator quantity from the environment and accumulate in their bodies radionuclides, various macro- and micronutrients, toxic substances of inorganic and organic origin, and so on. The gastropods are a taxonomically diverse, ecologically plastic and rather widespread group of aquatic organisms, whose role in the life of freshwater ecosystems is very important. Molluscs often have various interactions in biogeocenoses that determines their trophic net. As a rule, these interactions occur in the form of ectocommensalism, endocommensalism, supercrescence, predation or parasitism. The latter type of interaction is the subject of many studies, but the epibionts of gastropods and bivalves have practically not been studied and this research is an effort towards filling this gap. Species composition of algal epibionts identifies specific sensitivity to the effects of certain environmental factors and reflects the processes occurring in their ecosystem water bodies. This determines their efficient use for analyzing changes of water bodies as aquatic habitat, particularly in terms of complex anthropogenic pressure on aquatic ecosystems. The aim of the research was to determine the ecological characteristics of algal communities on gastropod shells: Lymnaea stagnalis, L. auricularia and Viviparus viviparus (the Uzh river, Korosten district, Zhytomyr region. Identified microalgae communities were grouped and studied according to such indices as: confinedness to the habitat (substrate, temperature, fluidity and water oxygenating, saprobiological characteristics according to the Pantle-Buck system in the modification of Sladecek and Watanabe, salinity according to Kolbe’s system, pH at Hustedt scale in the interpretation of M. M. Davydova and geographical limitations of the objects of study. Algal fouling on the shells L. stagnalis

  10. Evolution of red algal plastid genomes: ancient architectures, introns, horizontal gene transfer, and taxonomic utility of plastid markers.

    Directory of Open Access Journals (Sweden)

    Jan Janouškovec

    Full Text Available Red algae have the most gene-rich plastid genomes known, but despite their evolutionary importance these genomes remain poorly sampled. Here we characterize three complete and one partial plastid genome from a diverse range of florideophytes. By unifying annotations across all available red algal plastid genomes we show they all share a highly compact and slowly-evolving architecture and uniquely rich gene complements. Both chromosome structure and gene content have changed very little during red algal diversification, and suggest that plastid-to nucleus gene transfers have been rare. Despite their ancient character, however, the red algal plastids also contain several unprecedented features, including a group II intron in a tRNA-Met gene that encodes the first example of red algal plastid intron maturase - a feature uniquely shared among florideophytes. We also identify a rare case of a horizontally-acquired proteobacterial operon, and propose this operon may have been recruited for plastid function and potentially replaced a nucleus-encoded plastid-targeted paralogue. Plastid genome phylogenies yield a fully resolved tree and suggest that plastid DNA is a useful tool for resolving red algal relationships. Lastly, we estimate the evolutionary rates among more than 200 plastid genes, and assess their usefulness for species and subspecies taxonomy by comparison to well-established barcoding markers such as cox1 and rbcL. Overall, these data demonstrates that red algal plastid genomes are easily obtainable using high-throughput sequencing of total genomic DNA, interesting from evolutionary perspectives, and promising in resolving red algal relationships at evolutionarily-deep and species/subspecies levels.

  11. Responses of Algal Cells to Engineered Nanoparticles Measured as Algal Cell Population, Chlorophyll a, and Lipid Peroxidation: Effect of Particle Size and Type

    OpenAIRE

    D. M. Metzler; A. Erdem; Y. H. Tseng; C. P. Huang

    2012-01-01

    This paper investigated toxicity of three engineered nanoparticles (ENP), namely, Al2O3, SiO2, and TiO2 to the unicellular green algae, exemplified by Pseudokirchneriella subcapitata with an emphasis on particle size. The changes in pH, cell counts, chlorophyll a, and lipid peroxidation were used to measure the responses of the algal species to ENP. The most toxic particle size was TiO2 at 42 nm with an EC20 of 5.2 mg/L and Al2O3 at 14–18 nm with an EC20 of 5.1 mg/L. SiO2 was the least toxic...

  12. Dynamics of Bacterial and Fungal Communities during the Outbreak and Decline of an Algal Bloom in a Drinking Water Reservoir

    Directory of Open Access Journals (Sweden)

    Haihan Zhang

    2018-02-01

    Full Text Available The microbial communities associated with algal blooms play a pivotal role in organic carbon, nitrogen and phosphorus cycling in freshwater ecosystems. However, there have been few studies focused on unveiling the dynamics of bacterial and fungal communities during the outbreak and decline of algal blooms in drinking water reservoirs. To address this issue, the compositions of bacterial and fungal communities were assessed in the Zhoucun drinking water reservoir using 16S rRNA and internal transcribed spacer (ITS gene Illumina MiSeq sequencing techniques. The results showed the algal bloom was dominated by Synechococcus, Microcystis, and Prochlorothrix. The bloom was characterized by a steady decrease of total phosphorus (TP from the outbreak to the decline period (p < 0.05 while Fe concentration increased sharply during the decline period (p < 0.05. The highest algal biomass and cell concentrations observed during the bloom were 51.7 mg/L and 1.9×108 cell/L, respectively. The cell concentration was positively correlated with CODMn (r = 0.89, p = 0.02. Illumina Miseq sequencing showed that algal bloom altered the water bacterial and fungal community structure. During the bloom, the dominant bacterial genus were Acinetobacter sp., Limnobacter sp., Synechococcus sp., and Roseomonas sp. The relative size of the fungal community also changed with algal bloom and its composition mainly contained Ascomycota, Basidiomycota and Chytridiomycota. Heat map profiling indicated that algal bloom had a more consistent effect upon fungal communities at genus level. Redundancy analysis (RDA also demonstrated that the structure of water bacterial communities was significantly correlated to conductivity and ammonia nitrogen. Meanwhile, water temperature, Fe and ammonia nitrogen drive the dynamics of water fungal communities. The results from this work suggested that water bacterial and fungal communities changed significantly during the outbreak and decline of

  13. The spatial and temporal dynamic of algal biomass associated with mangrove roots in Buenaventura bay pacific coast of Colombia

    International Nuclear Information System (INIS)

    Pena Salamanca, Enrique Javier

    2008-01-01

    The spatial and temporal variation of biomass of mangrove associated macro algae growing on roots of Rhizophora mangle and pneumatophores of Avicennia. germinans were studied at three sampling stations in Buenaventura bay, Colombia, between November 1999 and September 2003. Eighteen species of algae were collected including nine Rhodophyceae, five Chlorophyceae and four Cyanophyta (Cyanobacteria). Four species dominated the algal flora and collectively contributed with 90 % of the total algal biomass. Bostrychia calliptera was the most dominant with 32 % of the total biomass, followed by Boodleopsis verticillata (26 %), Catenella impudica (18 %), and Caloglossa leprieurii (12 %) Algal biomass between seasons showed significant differences, with higher biomass found during the dry season compared to those of the rainy season. The algal biomass at the mouth of the estuary was significantly higher than that found in the inner areas of the estuary (annual means of 30.7 ± 10.8 vs. 13.8 ± 4.1 g m 2 respectively).Three well-defined vertical zones were observed, based on algal biomass

  14. 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.

  15. Algal bloom sedimentation induces variable control of lake eutrophication by phosphorus inactivating agents

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Changhui [State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008 (China); Bai, Leilei [State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008 (China); Graduate University of Chinese Academy of Sciences (China); Jiang, He-Long, E-mail: hljiang@niglas.ac.cn [State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008 (China); Xu, Huacheng [State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008 (China)

    2016-07-01

    Lake eutrophication typically occurs with a syndrome of algae breeding and biomass accumulation (e.g., algal blooms). Therefore, the effect of algal bloom sedimentation on eutrophication control by phosphorus (P) inactivating agents was assessed herein. Three commercial products, including aluminum (Al) sulfate, iron (Fe) sulfate, and a lanthanum-modified clay (Phoslock®), as well as one easily available by-product, drinking water treatment residue (DWTR), were selected. The most important finding was that during algae sedimentation, P immobilization from the overlying water by Al, Phoslock®, and DWTR was dominated by a long-term slow phase (> 150 d), while Fe has limited effectiveness on the immobilization. Further analysis indicated that the algae sedimentation effect was mainly due to the slow release of P from algae, leading to relatively limited P available for the inactivating agents. Then, a more unfavorable effect on the P immobilization capability of inactivating agents was caused by the induced anaerobic conditions, the released organic matter from algae, and the increased sulfide in the overlying water and sediments during sedimentation. Overall, algae sedimentation induced variable control of eutrophication by P inactivating agents. Accordingly, recommendations for future works about algal lake restoration were also proposed. - Highlights: • A long-term P immobilization by Phoslock®, DWTR, and Al was observed. • Fe had limited effectiveness on P pollution control for overlying water. • Al and Fe enhanced sulfur reduction, while DWTR and Phoslock® had minor effect. • The sedimentation reduced Al and La release from agents, but enhanced Fe release. • The agents changed organic matter compositions and structures in water columns.

  16. Algal testing of titanium dioxide nanoparticles-Testing considerations, inhibitory effects and modification of cadmium bioavailability

    International Nuclear Information System (INIS)

    Hartmann, N.B.; Von der Kammer, F.; Hofmann, T.; Baalousha, M.; Ottofuelling, S.; Baun, A.

    2010-01-01

    The ecotoxicity of three different sizes of titanium dioxide (TiO 2 ) particles (primary particles sizes: 10, 30, and 300 nm) to the freshwater green alga Pseudokirchneriella subcapitata was investigated in this study. Algal growth inhibition was found for all three particle types, but the physiological mode of action is not yet clear. It was possible to establish a concentration/dose-response relationship for the three particle sizes. Reproducibility, however, was affected by concentration-dependent aggregation of the nanoparticles, subsequent sedimentation, and possible attachment to vessel surfaces. It is also believed that heteroaggregation, driven by algal exopolymeric exudates, is occurring and could influence the concentration-response relationship. The ecotoxicity of cadmium to algae was investigated both in the presence and absence of 2 mg/L TiO 2 . The presence of TiO 2 in algal tests reduced the observed toxicity due to decreased bioavailability of cadmium resulting from sorption/complexation of Cd 2+ ions to the TiO 2 surface. However, for the 30 nm TiO 2 nanoparticles, the observed growth inhibition was greater than what could be explained by the concentration of dissolved Cd(II) species, indicating a possible carrier effect, or combined toxic effect of TiO 2 nanoparticles and cadmium. These results emphasize the importance of systematic studies of nanoecotoxicological effects of different sizes of nanoparticles and underline the fact that, in addition to particle toxicity, potential interactions with existing environmental contaminants are also of crucial importance in assessing the potential environmental risks of nanoparticles.

  17. Recreational Exposure to Low Concentrations of Microcystins During an Algal Bloom in a Small Lake

    Directory of Open Access Journals (Sweden)

    Yung-Sung Cheng

    2008-06-01

    Full Text Available We measured microcystins in blood from people at risk for swallowing water or inhaling spray while swimming, water skiing, jet skiing, or boating during an algal bloom. We monitored water samples from a small lake as a Microcystis aeruginosa bloom developed. We recruited 97 people planning recreational activities in that lake and seven others who volunteered to recreate in a nearby bloom-free lake. We conducted our field study within a week of finding a 10-μg/L microcystin concentration. We analyzed water, air, and human blood samples for water quality, potential human pathogens, algal taxonomy, and microcystin concentrations. We interviewed study participants for demographic and current health symptom information. Water samples were assayed for potential respiratory viruses (adenoviruses and enteroviruses, but none were detected. We did find low concentrations of Escherichia coli, indicating fecal contamination. We found low levels of microcystins (2 μg/L to 5 μg/L in the water and (<0.1 ng/m3 in the aerosol samples. Blood levels of microcystins for all participants were below the limit of detection (0.147μg/L. Given this low exposure level, study participants reported no symptom increases following recreational exposure to microcystins. This is the first study to report that water-based recreational activities can expose people to very low concentrations of aerosol-borne microcystins; we recently conducted another field study to assess exposures to higher concentrations of these algal toxins.

  18. Enhanced coal-dependent methanogenesis coupled with algal biofuels: Potential water recycle and carbon capture

    Science.gov (United States)

    Barnhart, Elliott P.; Davis, Katherine J.; Varonka, Matthew; Orem, William H.; Cunningham, Alfred B.; Ramsay, Bradley D.; Fields, Matthew W.

    2017-01-01

    Many coal beds contain microbial communities that can convert coal to natural gas (coalbed methane). Native microorganisms were obtained from Powder River Basin (PRB) coal seams with a diffusive microbial sampler placed downhole and used as an inoculum for enrichments with different nutrients to investigate microbially-enhanced coalbed methane production (MECoM). Coal-dependent methanogenesis more than doubled when yeast extract (YE) and several less complex components (proteins and amino acids) were added to the laboratory microcosms. Stimulated coal-dependent methanogenesis with peptone was 86% of that with YE while glutamate-stimulated activity was 65% of that with YE, and a vitamin mix had only 33% of the YE stimulated activity. For field application of MECoM, there is interest in identifying cost-effective alternatives to YE and other expensive nutrients. In laboratory studies, adding algal extract (AE) with lipids removed stimulated coal-dependent methanogenesis and the activity was 60% of that with YE at 27 d and almost 90% of YE activity at 1406 d. Analysis of British Thermal Unit (BTU) content of coal (a measure of potential energy yield) from long-term incubations indicated > 99.5% of BTU content remained after coalbed methane (CBM) stimulation with either AE or YE. Thus, the coal resource remains largely unchanged following stimulated microbial methane production. Algal CBM stimulation could lead to technologies that utilize coupled biological systems (photosynthesis and methane production) that sustainably enhance CBM production and generate algal biofuels while also sequestering carbon dioxide (CO2).

  19. Concurrent Exposure of Bottlenose Dolphins (Tursiops truncatus) to Multiple Algal Toxins in Sarasota Bay, Florida, USA

    Science.gov (United States)

    Twiner, Michael J.; Fire, Spencer; Schwacke, Lori; Davidson, Leigh; Wang, Zhihong; Morton, Steve; Roth, Stephen; Balmer, Brian; Rowles, Teresa K.; Wells, Randall S.

    2011-01-01

    Sentinel species such as bottlenose dolphins (Tursiops truncatus) can be impacted by large-scale mortality events due to exposure to marine algal toxins. In the Sarasota Bay region (Gulf of Mexico, Florida, USA), the bottlenose dolphin population is frequently exposed to harmful algal blooms (HABs) of Karenia brevis and the neurotoxic brevetoxins (PbTx; BTX) produced by this dinoflagellate. Live dolphins sampled during capture-release health assessments performed in this region tested positive for two HAB toxins; brevetoxin and domoic acid (DA). Over a ten-year study period (2000–2009) we have determined that bottlenose dolphins are exposed to brevetoxin and/or DA on a nearly annual basis (i.e., DA: 2004, 2005, 2006, 2008, 2009; brevetoxin: 2000, 2004, 2005, 2008, 2009) with 36% of all animals testing positive for brevetoxin (n = 118) and 53% positive for DA (n = 83) with several individuals (14%) testing positive for both neurotoxins in at least one tissue/fluid. To date there have been no previously published reports of DA in southwestern Florida marine mammals, however the May 2008 health assessment coincided with a Pseudo-nitzschia pseudodelicatissima bloom that was the likely source of DA observed in seawater and live dolphin samples. Concurrently, both DA and brevetoxin were observed in common prey fish. Although no Pseudo-nitzschia bloom was identified the following year, DA was identified in seawater, fish, sediment, snails, and dolphins. DA concentrations in feces were positively correlated with hematologic parameters including an increase in total white blood cell (p = 0.001) and eosinophil (p<0.001) counts. Our findings demonstrate that dolphins within Sarasota Bay are commonly exposed to two algal toxins, and provide the impetus to further explore the potential long-term impacts on bottlenose dolphin health. PMID:21423740

  20. Concurrent exposure of bottlenose dolphins (Tursiops truncatus to multiple algal toxins in Sarasota Bay, Florida, USA.

    Directory of Open Access Journals (Sweden)

    Michael J Twiner

    Full Text Available Sentinel species such as bottlenose dolphins (Tursiops truncatus can be impacted by large-scale mortality events due to exposure to marine algal toxins. In the Sarasota Bay region (Gulf of Mexico, Florida, USA, the bottlenose dolphin population is frequently exposed to harmful algal blooms (HABs of Karenia brevis and the neurotoxic brevetoxins (PbTx; BTX produced by this dinoflagellate. Live dolphins sampled during capture-release health assessments performed in this region tested positive for two HAB toxins; brevetoxin and domoic acid (DA. Over a ten-year study period (2000-2009 we have determined that bottlenose dolphins are exposed to brevetoxin and/or DA on a nearly annual basis (i.e., DA: 2004, 2005, 2006, 2008, 2009; brevetoxin: 2000, 2004, 2005, 2008, 2009 with 36% of all animals testing positive for brevetoxin (n = 118 and 53% positive for DA (n = 83 with several individuals (14% testing positive for both neurotoxins in at least one tissue/fluid. To date there have been no previously published reports of DA in southwestern Florida marine mammals, however the May 2008 health assessment coincided with a Pseudo-nitzschia pseudodelicatissima bloom that was the likely source of DA observed in seawater and live dolphin samples. Concurrently, both DA and brevetoxin were observed in common prey fish. Although no Pseudo-nitzschia bloom was identified the following year, DA was identified in seawater, fish, sediment, snails, and dolphins. DA concentrations in feces were positively correlated with hematologic parameters including an increase in total white blood cell (p = 0.001 and eosinophil (p<0.001 counts. Our findings demonstrate that dolphins within Sarasota Bay are commonly exposed to two algal toxins, and provide the impetus to further explore the potential long-term impacts on bottlenose dolphin health.

  1. Ocean acidification induces changes in algal palatability and herbivore feeding behavior and performance.

    Science.gov (United States)

    Duarte, Cristian; López, Jorge; Benítez, Samanta; Manríquez, Patricio H; Navarro, Jorge M; Bonta, Cesar C; Torres, Rodrigo; Quijón, Pedro

    2016-02-01

    The effects of global stressors on a species may be mediated by the stressors' impact on coexisting taxa. For instance, herbivore-algae interactions may change due to alterations in algal nutritional quality resulting from high CO2 levels associated with ocean acidification (OA). We approached this issue by assessing the indirect effects of OA on the trophic interactions between the amphipod Orchestoidea tuberculata and the brown alga Durvillaea antarctica, two prominent species of the South-east Pacific coast. We predicted that amphipod feeding behavior and performance (growth rate) will be affected by changes in the palatability of the algae exposed to high levels (1000 ppm) of CO2. We exposed algae to current and predicted (OA) atmospheric CO2 levels and then measured their nutritive quality and amphipod preference in choice trials. We also assessed consumption rates separately in no-choice trials, and measured amphipod absorption efficiency and growth rates. Protein and organic contents of the algae decreased in acidified conditions and amphipods showed low preference for these algae. However, in the no-choice trials we recorded higher grazing rates on algae exposed to OA. Although amphipod absorption efficiency was lower on these algae, growth rates did not differ between treatments, which suggests the occurrence of compensatory feeding. Our results suggest that changes in algal nutritional value in response to OA induce changes in algal palatability and these in turn affect consumers' food preference and performance. Indirect effects of global stressors like OA can be equally or more important than the direct effects predicted in the literature.

  2. Algal bloom sedimentation induces variable control of lake eutrophication by phosphorus inactivating agents

    International Nuclear Information System (INIS)

    Wang, Changhui; Bai, Leilei; Jiang, He-Long; Xu, Huacheng

    2016-01-01

    Lake eutrophication typically occurs with a syndrome of algae breeding and biomass accumulation (e.g., algal blooms). Therefore, the effect of algal bloom sedimentation on eutrophication control by phosphorus (P) inactivating agents was assessed herein. Three commercial products, including aluminum (Al) sulfate, iron (Fe) sulfate, and a lanthanum-modified clay (Phoslock®), as well as one easily available by-product, drinking water treatment residue (DWTR), were selected. The most important finding was that during algae sedimentation, P immobilization from the overlying water by Al, Phoslock®, and DWTR was dominated by a long-term slow phase (> 150 d), while Fe has limited effectiveness on the immobilization. Further analysis indicated that the algae sedimentation effect was mainly due to the slow release of P from algae, leading to relatively limited P available for the inactivating agents. Then, a more unfavorable effect on the P immobilization capability of inactivating agents was caused by the induced anaerobic conditions, the released organic matter from algae, and the increased sulfide in the overlying water and sediments during sedimentation. Overall, algae sedimentation induced variable control of eutrophication by P inactivating agents. Accordingly, recommendations for future works about algal lake restoration were also proposed. - Highlights: • A long-term P immobilization by Phoslock®, DWTR, and Al was observed. • Fe had limited effectiveness on P pollution control for overlying water. • Al and Fe enhanced sulfur reduction, while DWTR and Phoslock® had minor effect. • The sedimentation reduced Al and La release from agents, but enhanced Fe release. • The agents changed organic matter compositions and structures in water columns.

  3. Changes in habitat complexity negatively affect diverse gastropod assemblages in coralline algal turf.

    Science.gov (United States)

    Kelaher, B P

    2003-05-01

    The physical structure of a habitat generally has a strong influence on the diversity and abundance of associated organisms. I investigated the role of coralline algal turf structure in determining spatial variation of gastropod assemblages at different tidal heights of a rocky shore near Sydney, Australia. The structural characteristics of algal turf tested were frond density (or structural complexity) and frond length (the vertical scale over which structural complexity was measured). This definition of structural complexity assumes that complexity of the habitat increases with increasing frond density. While frond length was unrelated to gastropod community structure, I found significant correlations between density of fronds and multivariate and univariate measures of gastropod assemblages, indicating the importance of structural complexity. In contrast to previous studies, here there were negative relationships between the density of fronds and the richness and abundance of gastropods. Artificial habitat mimics were used to manipulate the density of fronds to test the hypothesis that increasing algal structural complexity decreases the richness and abundance of gastropods. As predicted, there were significantly more species of gastropods in loosely packed than in tightly packed turf at both low- and mid-shore levels. Despite large differences between gastropod assemblages at different tidal heights, the direction and magnitude of these negative effects were similar at low- and mid-shore levels and, therefore, relatively independent of local environmental conditions. These novel results extend our previous understanding of the ecological effects of habitat structure because they demonstrate possible limitations of commonly used definitions of structural complexity, as well as distinct upper thresholds in the relationship between structural complexity and faunal species richness.

  4. Raman Microspectroscopy of Individual Algal Cells: Sensing Unsaturation of Storage Lipids in vivo

    Czech Academy of Sciences Publication Activity Database

    Samek, Ota; Jonáš, Alexandr; Pilát, Zdeněk; Zemánek, Pavel; Nedbal, Ladislav; Tříska, Jan; Kotas, Petr; Trtílek, M.

    2010-01-01

    Roč. 10, č. 9 (2010), s. 8635-8651 ISSN 1424-8220 R&D Projects: GA MŠk ED0017/01/01; GA MŠk OC08034; GA MPO FR-TI1/433; GA ČR GA206/09/1284 Grant - others:EU(XE) PERG 06-GA-2009-256526 Institutional research plan: CEZ:AV0Z20650511; CEZ:AV0Z60870520 Keywords : Raman spectroscopy * algal cells * lipids * iodine value Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.771, year: 2010

  5. Prevalent and persistent viral infection in cultures of the coral algal endosymbiont Symbiodinium

    Science.gov (United States)

    Weynberg, Karen D.; Neave, Matthew; Clode, Peta L.; Voolstra, Christian R.; Brownlee, Christopher; Laffy, Patrick; Webster, Nicole S.; Levin, Rachel A.; Wood-Charlson, Elisha M.; van Oppen, Madeleine J. H.

    2017-09-01

    Reef corals are under threat from bleaching and disease outbreaks that target both the host animal and the algal symbionts within the coral holobiont. A viral origin for coral bleaching has been hypothesized, but direct evidence has remained elusive. Using a multifaceted approach incorporating flow cytometry, transmission electron microscopy, DNA and RNA virome sequencing, we show that type C1 Symbiodinium cultures host a nucleocytoplasmic large double-stranded DNA virus (NCLDV) related to Phycodnaviridae and Mimiviridae, a novel filamentous virus of unknown phylogenetic affiliation, and a single-stranded RNA virus related to retroviruses. We discuss implications of these findings for laboratory-based experiments using Symbiodinium cultures.

  6. Algal autolysate medium to label proteins for NMR in mammalian cells.

    Science.gov (United States)

    Fuccio, Carmelo; Luchinat, Enrico; Barbieri, Letizia; Neri, Sara; Fragai, Marco

    2016-04-01

    In-cell NMR provides structural and functional information on proteins directly inside living cells. At present, the high costs of the labeled media for mammalian cells represent a limiting factor for the development of this methodology. Here we report a protocol to prepare a homemade growth medium from Spirulina platensis autolysate, suitable to express uniformly labeled proteins inside mammalian cells at a reduced cost-per-sample. The human proteins SOD1 and Mia40 were overexpressed in human cells grown in (15)N-enriched S. platensis algal-derived medium, and high quality in-cell NMR spectra were obtained.

  7. Prevalent and persistent viral infection in cultures of the coral algal endosymbiont Symbiodinium

    KAUST Repository

    Weynberg, Karen D.; Neave, Matthew J.; Clode, Peta L.; Voolstra, Christian R.; Brownlee, Christopher; Laffy, Patrick; Webster, Nicole S.; Levin, Rachel A.; Wood-Charlson, Elisha M.; Oppen, Madeleine J. H.

    2017-01-01

    Reef corals are under threat from bleaching and disease outbreaks that target both the host animal and the algal symbionts within the coral holobiont. A viral origin for coral bleaching has been hypothesized, but direct evidence has remained elusive. Using a multifaceted approach incorporating flow cytometry, transmission electron microscopy, DNA and RNA virome sequencing, we show that type C1 Symbiodinium cultures host a nucleocytoplasmic large double-stranded DNA virus (NCLDV) related to Phycodnaviridae and Mimiviridae, a novel filamentous virus of unknown phylogenetic affiliation, and a single-stranded RNA virus related to retroviruses. We discuss implications of these findings for laboratory-based experiments using Symbiodinium cultures.

  8. Thallophytic algal flora from a new Silurian Lagerstätte

    Directory of Open Access Journals (Sweden)

    Tinn, Oive

    2009-03-01

    Full Text Available Algae have always been the most diverse and numerous eukaryotic autotrophs in marine ecosystems. Both fossil andmolecular data point to an early Proterozoic origin for algae. Although known for their long evolutionary history, the fossil recordof algae is sparse and mainly remains of taxa with heavily calcified thalli are preserved. However, fossils of noncalcareous algae,known as extremely sporadic and occasional finds from different parts of the world, provide important insights into thepalaeobiology of algal flora in the Earth's past. Here we describe highly diverse flora of noncalcareous thallophytic algae from aSilurian age deposit.

  9. Algal Biomass Analysis by Laser-Based Analytical Techniques—A Review

    Czech Academy of Sciences Publication Activity Database

    Pořízka, P.; Procházková, P.; Procházka, D.; Sládková, L.; Novotný, J.; Petrilak, M.; Brada, M.; Samek, Ota; Pilát, Zdeněk; Zemánek, Pavel; Adam, V.; Kizek, R.; Novotný, K.; Kaiser, J.

    2014-01-01

    Roč. 14, 23 SEP (2014), s. 17725-17752 ISSN 1424-8220 R&D Projects: GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01; GA ČR GAP205/11/1687 Institutional support: RVO:68081731 Keywords : Laser-Induced Breakdown Spectroscopy * LIBS * Laser-Ablation Inductively Coupled Plasma coupled with Mass Spectroscopy and Optical Emission Spectroscopy * LA-ICP-MS * LA-ICP-OES * ICP-OES * Raman spectroscopy * algae * algal biomass * biofuel * bioremediation Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.245, year: 2014

  10. The host transcriptome remains unaltered during the establishment of coral-algal symbioses.

    Science.gov (United States)

    Voolstra, Christian R; Schwarz, Jodi A; Schnetzer, Julia; Sunagawa, Shinichi; Desalvo, Michael K; Szmant, Alina M; Coffroth, Mary Alice; Medina, Mónica

    2009-05-01

    Coral reefs are based on the symbiotic relationship between corals and photosynthetic dinoflagellates of the genus Symbiodinium. We followed gene expression of coral larvae of Acropora palmata and Montastraea faveolata after exposure to Symbiodinium strains that differed in their ability to establish symbioses. We show that the coral host transcriptome remains almost unchanged during infection by competent symbionts, but is massively altered by symbionts that fail to establish symbioses. Our data suggest that successful coral-algal symbioses depend mainly on the symbionts' ability to enter the host in a stealth manner rather than a more active response from the coral host.

  11. A Framework for Sustainable Design of Algal Biorefineries: Economic Aspects and Life Cycle Analysis

    DEFF Research Database (Denmark)

    Cheali, Peam; Loureiro da Costa Lira Gargalo, Carina; Gernaey, Krist

    2015-01-01

    mathematically as a mixed integer nonlinear programming problem, and is solved first to identify the optimal designs with respect to economic optimality. These optimal designs are then analyzed further in terms of environmental performance using life cycle analysis. For sustainability analysis, in total five...... of algae feedstock for the production of biodiesel and co-products. Relevant data and parameters for each process such as yield, conversion, operational cost is then collected using a standardized format (a generic model) and stored in a database. The sustainable design problem is then formulated...... of future and sustainable algal biorefinery concepts....

  12. Harmful algal blooms and climate change: Learning from the past and present to forecast the future

    CSIR Research Space (South Africa)

    Wells, ML

    2015-11-01

    Full Text Available Harmful algal blooms and climate change: Learning from the past and present to forecast the future Mark L. Wellsa,*, Vera L. Trainerb, Theodore J. Smaydac, Bengt S.O. Karlsond, Charles G. Tricke, Raphael M. Kudelaf, Akira Ishikawag, Stewart Bernardh... and Atmospheric Administration, 2725 Montlake Blvd. E., Seattle, WA 98112, USA c Graduate School of Oceanography, University of Rhode Island, Kingston, RI 02881, USA d SMHI Research & Development, Oceanography, Sven Ka¨llfelts gata 15, 426 71 Va¨stra Fro...

  13. Algal autolysate medium to label proteins for NMR in mammalian cells

    Energy Technology Data Exchange (ETDEWEB)

    Fuccio, Carmelo; Luchinat, Enrico; Barbieri, Letizia [University of Florence, Magnetic Resonance Center (CERM) (Italy); Neri, Sara [Giotto Biotech S.R.L. (Italy); Fragai, Marco, E-mail: fragai@cerm.unifi.it [University of Florence, Magnetic Resonance Center (CERM) (Italy)

    2016-04-15

    In-cell NMR provides structural and functional information on proteins directly inside living cells. At present, the high costs of the labeled media for mammalian cells represent a limiting factor for the development of this methodology. Here we report a protocol to prepare a homemade growth medium from Spirulina platensis autolysate, suitable to express uniformly labeled proteins inside mammalian cells at a reduced cost-per-sample. The human proteins SOD1 and Mia40 were overexpressed in human cells grown in {sup 15}N-enriched S. platensis algal-derived medium, and high quality in-cell NMR spectra were obtained.

  14. Physicochemical transformation and algal toxicity of engineered nanoparticles in surface water samples

    International Nuclear Information System (INIS)

    Zhang, Luqing; Li, Jingyi; Yang, Kun; Liu, Jingfu; Lin, Daohui

    2016-01-01

    Most studies on the behavior and toxicity of engineered nanoparticles (NPs) have been conducted in artificial water with well-controlled conditions, which are dramatically different from natural waters with complex compositions. To better understand the fate and toxicity of NPs in the natural water environment, physicochemical transformations of four NPs (TiO_2, ZnO, Ag, and carbon nanotubes (CNTs)) and their toxicities towards a unicellular green alga (Chlorella pyrenoidosa) in four fresh water and one seawater sample were investigated. Results indicated that water chemistry had profound effects on aggregation, dissolution, and algal toxicity of the NPs. The strongest homoaggregation of the NPs was associated with the highest ionic strength, but no obvious correlation was observed between the homoaggregation of NPs and pH or dissolved organic matter content of the water samples. The greatest dissolution of ZnO NPs also occurred in seawater with the highest ionic strength, while the dissolution of Ag NPs varied differently from ZnO NPs. The released Zn"2"+ and especially Ag"+ mainly accounted for the algal toxicity of ZnO and Ag NPs, respectively. The NP-cell heteroagglomeration occurred generally for CNTs and Ag NPs, which contributed to the observed nanotoxicity. However, there was no significant correlation between the observed nanotoxicity and the type of NP or the water chemistry. It was thus concluded that the physicochemical transformations and algal toxicities of NPs in the natural water samples were caused by the combined effects of complex water quality parameters rather than any single influencing factor alone. These results will increase our knowledge on the fate and effects of NPs in the aquatic environment. - Highlights: • Transformation and algal toxicity of four NPs in five surface water samples were studied. • The transformation and toxicity were dependent on the types of NPs and water samples. • No single water parameter alone was

  15. ASSAYS OF ALGAL BIO-STIMULATION WITH DIFFERENT NITROGEN-PHOSPHORUS RELATIONS UNDER LABORATORY CONDITIONS

    OpenAIRE

    Aguirre Ramírez, Néstor J.; Palacio Baena, Jaime A.; Correa Ochoa, Isabel C.; Hernández Atilano, Esnedy

    2007-01-01

    Esta investigación tuvo como objetivo evaluar el crecimiento del alga Chlorella vulgaris ante diferentes concentraciones de nitrógeno y fósforo, a través de ensayos de bioestimulación en una cámara ambiental. Las variables respuesta fueron la densidad algal y la turbidez, evaluadas por conteo en una cámara de Neubauer y por espectrofotometría, empleando un equipo NOVA 60. Para los ensayos de bioestimulación se utilizó el medio de cultivo Estándar Métodos, sugerido por APHA, AWWA (1995) con di...

  16. 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

    a robust, reversible increase in amplitude mic spikes, and the appearance of multiple spikes (i.e., epileptiform activity) within minutes of toxin wash-in. Other notable features of the domoic acid signature included a significant decrease in amplitude of the field EPSPs, and a complete absence of effect...... responsive fashion at toxin concentrations of 25-200 nM, and tests of naturally contaminated shellfish confirmed the utility of this assay as a screening method for PSP. Our findings suggest that the in vitro hippocampal slice preparation has potential in the detection and analysis of three marine algal...

  17. Prevalent and persistent viral infection in cultures of the coral algal endosymbiont Symbiodinium

    KAUST Repository

    Weynberg, Karen D.

    2017-03-17

    Reef corals are under threat from bleaching and disease outbreaks that target both the host animal and the algal symbionts within the coral holobiont. A viral origin for coral bleaching has been hypothesized, but direct evidence has remained elusive. Using a multifaceted approach incorporating flow cytometry, transmission electron microscopy, DNA and RNA virome sequencing, we show that type C1 Symbiodinium cultures host a nucleocytoplasmic large double-stranded DNA virus (NCLDV) related to Phycodnaviridae and Mimiviridae, a novel filamentous virus of unknown phylogenetic affiliation, and a single-stranded RNA virus related to retroviruses. We discuss implications of these findings for laboratory-based experiments using Symbiodinium cultures.

  18. 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...

  19. Preliminary identification of unicellular algal genus by using combined confocal resonance Raman spectroscopy with PCA and DPLS analysis

    Science.gov (United States)

    He, Shixuan; Xie, Wanyi; Zhang, Ping; Fang, Shaoxi; Li, Zhe; Tang, Peng; Gao, Xia; Guo, Jinsong; Tlili, Chaker; Wang, Deqiang

    2018-02-01

    The analysis of algae and dominant alga plays important roles in ecological and environmental fields since it can be used to forecast water bloom and control its potential deleterious effects. Herein, we combine in vivo confocal resonance Raman spectroscopy with multivariate analysis methods to preliminary identify the three algal genera in water blooms at unicellular scale. Statistical analysis of characteristic Raman peaks demonstrates that certain shifts and different normalized intensities, resulting from composition of different carotenoids, exist in Raman spectra of three algal cells. Principal component analysis (PCA) scores and corresponding loading weights show some differences from Raman spectral characteristics which are caused by vibrations of carotenoids in unicellular algae. Then, discriminant partial least squares (DPLS) classification method is used to verify the effectiveness of algal identification with confocal resonance Raman spectroscopy. Our results show that confocal resonance Raman spectroscopy combined with PCA and DPLS could handle the preliminary identification of dominant alga for forecasting and controlling of water blooms.

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

    Science.gov (United States)

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

    1997-01-01

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

  1. Growth of mussels Mytilus edulis at algal (Rhodomonas salina) concentrations below and above saturation level for reduced filtration rate

    DEFF Research Database (Denmark)

    Riisgård, Hans Ulrik; Pleissner, Daniel; Larsen, Poul Scheel

    2013-01-01

    Average filtration and growth rates of groups of juvenile Mytilus edulis (n =2545 of 22-35 mm shell length) were measured at different concentrations of an algal cell monoculture in 9 laboratory experiments of duration 14-30 days, 4 experiments below and 5 above the limit of incipient saturation...... concentration (Csat ≈ 6000-7000 Rhodomonas salina cells ml-1). From a nearly constant filtration rate (F ≈ 30 ml min-1 for a 30 mm shell length) at measured algal concentrations below Csat the steady-state filtration rate decreased approximately as 1/C for increasing algal concentrations (C) above Csat...... is exceeded and then as partial valve closure and reduced filtration and growth rates along with production of pseudofaeces. A survey of naturally occurring phytoplankton biomass in the sea shows that this is generally below Csat except for the short spring bloom periods; hence mussels generally feed...

  2. Comprehensive computational model for combining fluid hydrodynamics, light transport and biomass growth in a Taylor vortex algal photobioreactor: Lagrangian approach.

    Science.gov (United States)

    Gao, Xi; Kong, Bo; Vigil, R Dennis

    2017-01-01

    A comprehensive quantitative model incorporating the effects of fluid flow patterns, light distribution, and algal growth kinetics on biomass growth rate is developed in order to predict the performance of a Taylor vortex algal photobioreactor for culturing Chlorella vulgaris. A commonly used Lagrangian strategy for coupling the various factors influencing algal growth was employed whereby results from computational fluid dynamics and radiation transport simulations were used to compute numerous microorganism light exposure histories, and this information in turn was used to estimate the global biomass specific growth rate. The simulations provide good quantitative agreement with experimental data and correctly predict the trend in reactor performance as a key reactor operating parameter is varied (inner cylinder rotation speed). However, biomass growth curves are consistently over-predicted and potential causes for these over-predictions and drawbacks of the Lagrangian approach are addressed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Evaluation of algal biofilms on indium tin oxide (ITO for use in biophotovoltaic platforms based on photosynthetic performance.

    Directory of Open Access Journals (Sweden)

    Fong-Lee Ng

    Full Text Available In photosynthesis, a very small amount of the solar energy absorbed is transformed into chemical energy, while the rest is wasted as heat and fluorescence. This excess energy can be harvested through biophotovoltaic platforms to generate electrical energy. In this study, algal biofilms formed on ITO anodes were investigated for use in the algal biophotovoltaic platforms. Sixteen algal strains, comprising local isolates and two diatoms obtained from the Culture Collection of Marine Phytoplankton (CCMP, USA, were screened and eight were selected based on the growth rate, biochemical composition and photosynthesis performance using suspension cultures. Differences in biofilm formation between the eight algal strains as well as their rapid light curve (RLC generated using a pulse amplitude modulation (PAM fluorometer, were examined. The RLC provides detailed information on the saturation characteristics of electron transport and overall photosynthetic performance of the algae. Four algal strains, belonging to the Cyanophyta (Cyanobacteria Synechococcus elongatus (UMACC 105, Spirulina platensis. (UMACC 159 and the Chlorophyta Chlorella vulgaris (UMACC 051, and Chlorella sp. (UMACC 313 were finally selected for investigation using biophotovoltaic platforms. Based on power output per Chl-a content, the algae can be ranked as follows: Synechococcus elongatus (UMACC 105 (6.38×10(-5 Wm(-2/µgChl-a>Chlorella vulgaris UMACC 051 (2.24×10(-5 Wm(-2/µgChl-a>Chlorella sp.(UMACC 313 (1.43×10(-5 Wm(-2/µgChl-a>Spirulina platensis (UMACC 159 (4.90×10(-6 Wm(-2/µgChl-a. Our study showed that local algal strains have potential for use in biophotovoltaic platforms due to their high photosynthetic performance, ability to produce biofilm and generation of electrical power.

  4. A strategy for urban outdoor production of high-concentration algal biomass for green biorefining.

    Science.gov (United States)

    Lim, Chun Yong; Chen, Chia-Lung; Wang, Jing-Yuan

    2013-05-01

    The present study was to investigate the feasibility of carrying out effective microalgae cultivation and high-rate tertiary wastewater treatment simultaneously in a vertical sequencing batch photobioreactor with small areal footprint, suitable for sustainable urban microalgae production. For 15 consecutive days, Chlorella sorokiniana was cultivated in synthetic wastewater under various trophic conditions. A cycle of 12-h heterotrophic: 12-h mixotrophic condition produced 0.98 g l(-1) d(-1) of algal biomass in tandem with a 94.7% removal of 254.4 mg l(-1) C-acetate, a 100% removal of 84.7 mg l(-1) N-NH4 and a removal of 15.0 mg l(-1) P-PO4. The cells were harvested via cost-effective chitosan flocculation with multiple dosing (3 times) applying established chitosan:cell ratio (1:300 w/w) and pH control (6.3-6.8). Reproducible flocculation efficiencies of greater than 99% and high-concentration algal broths (>20% solids) were achieved. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Algal biofuels from urban wastewaters: maximizing biomass yield using nutrients recycled from hydrothermal processing of biomass.

    Science.gov (United States)

    Selvaratnam, T; Pegallapati, A K; Reddy, H; Kanapathipillai, N; Nirmalakhandan, N; Deng, S; Lammers, P J

    2015-04-01

    Recent studies have proposed algal cultivation in urban wastewaters for the dual purpose of waste treatment and bioenergy production from the resulting biomass. This study proposes an enhancement to this approach that integrates cultivation of an acidophilic strain, Galdieria sulphuraria 5587.1, in a closed photobioreactor (PBR); hydrothermal liquefaction (HTL) of the wet algal biomass; and recirculation of the nutrient-rich aqueous product (AP) of HTL to the PBR to achieve higher biomass productivity than that could be achieved with raw wastewater. The premise is that recycling nutrients in the AP can maintain optimal C, N and P levels in the PBR to maximize biomass growth to increase energy returns. Growth studies on the test species validated growth on AP derived from HTL at temperatures from 180 to 300°C. Doubling N and P concentrations over normal levels in wastewater resulted in biomass productivity gains of 20-25% while N and P removal rates also doubled. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Behavior and function of paternally inherited centrioles in brown algal zygotes.

    Science.gov (United States)

    Nagasato, Chikako

    2005-12-01

    In brown algal cells, the centrosome, consisting of a pair of centrioles and the pericentriolar material, is primarily involved in the organization of microtubules (MTs) throughout the cell cycle. In motile cells, the centrioles participate in the formation of flagellar axoneme as flagellar basal bodies, and in somatic cells they play a crucial role in many cellular activities as a part of the centrosome. With respect to the role of the centrosome as a microtubule organizing center (MTOC), brown algal cells resemble animal cells. In most animal fertilization processes, the sperm cell introduces centrioles, the core of the centrosome, into the egg cytoplasm. In this study, the behavior of centrioles from gametogenesis and fertilization to the first cell division of the zygote was examined in the three sexual reproduction patterns occurring in brown algae, i.e., oogamy, anisogamy and isogamy, by electron- and immunofluorescence-microscopy. The pair of centrioles contained in somatic cells was shown to be derived from the male gamete, irrespective of the sexual reproductive pattern. The paternally derived centrioles were duplicated before mitosis and were involved in spindle pole formation. Moreover, MTs from the centrosome play a crucial role in the process of cytokinesis, as the position of centrosomes accompanying daughter nuclei seems to determine the cytokinetic plane. A new approach to clarifying the mode of cytokinesis in brown algae is presented in this study.

  7. Techno-economic and life-cycle assessment of an attached growth algal biorefinery.

    Science.gov (United States)

    Barlow, Jay; Sims, Ronald C; Quinn, Jason C

    2016-11-01

    This study examined the sustainability of generating renewable diesel via hydrothermal liquefaction (HTL) of biomass from a rotating algal biofilm reactor. Pilot-scale growth studies and laboratory-scale HTL experiments were used to validate an engineering system model. The engineering system model served as the foundation to evaluate the economic feasibility and environmental impact of the system at full scale. Techno-economic results indicate that biomass feedstock costs dominated the minimum fuel selling price (MFSP), with a base case of $104.31per gallon. Life-cycle assessment results show a base-case global warming potential (GWP) of 80gCO2-eMJ(-1) and net energy ratio (NER) of 1.65 based on a well-to-product system boundary. Optimization of the system reduces MFSP, GWP and NER to $11.90Gal(-1), -44gCO2-eMJ(-1), and 0.33, respectively. The systems-level impacts of integrating algae cultivation with wastewater treatment were found to significantly reduce environmental impact. Sensitivity analysis showed that algal productivity most significantly affected fuel selling price, emphasizing the importance of optimizing biomass productivity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Improving nitrogen utilization efficiency of aquaponics by introducing algal-bacterial consortia.

    Science.gov (United States)

    Fang, Yingke; Hu, Zhen; Zou, Yina; Zhang, Jian; Zhu, Zhuoran; Zhang, Jianda; Nie, Lichao

    2017-12-01

    Aquaponics is a promising technology combining aquaculture with hydroponics. In this study, algal-bacterial consortia were introduced into aquaponics, i.e., algal-bacterial based aquaponics (AA), to improve the nitrogen utilization efficiency (NUE) of aquaponics. The results showed that the NUE of AA was 13.79% higher than that of media-based aquaponics (MA). In addition, higher NO 3 - removal by microalgae assimilation led to better water quality in AA, which made up for the deficiencies of poor aquaponic management of nitrate. As a result of lower NO 3 - concentrations and dramatically higher dissolved oxygen (DO) concentrations caused by microalgae photosynthesis in the photobioreactor, the N 2 O emission of AA was 89.89% lower than that of MA, although nosZ gene abundance in MA's hydroponic bed was approximately 30 times over that in AA. Considering the factors mentioned above, AA would improve the sustainability of aquaponics and have a good application foreground. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. 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. PMID:28084322

  10. Seasonal Dynamics of Haptophytes and dsDNA Algal Viruses Suggest Complex Virus-Host Relationship.

    Science.gov (United States)

    Johannessen, Torill Vik; Larsen, Aud; Bratbak, Gunnar; Pagarete, António; Edvardsen, Bente; Egge, Elianne D; Sandaa, Ruth-Anne

    2017-04-20

    Viruses influence the ecology and diversity of phytoplankton in the ocean. Most studies of phytoplankton host-virus interactions have focused on bloom-forming species like Emiliania huxleyi or Phaeocystis spp. The role of viruses infecting phytoplankton that do not form conspicuous blooms have received less attention. Here we explore the dynamics of phytoplankton and algal viruses over several sequential seasons, with a focus on the ubiquitous and diverse phytoplankton division Haptophyta, and their double-stranded DNA viruses, potentially with the capacity to infect the haptophytes. Viral and phytoplankton abundance and diversity showed recurrent seasonal changes, mainly explained by hydrographic conditions. By 454 tag-sequencing we revealed 93 unique haptophyte operational taxonomic units (OTUs), with seasonal changes in abundance. Sixty-one unique viral OTUs, representing Megaviridae and Phycodnaviridae , showed only distant relationship with currently isolated algal viruses. Haptophyte and virus community composition and diversity varied substantially throughout the year, but in an uncoordinated manner. A minority of the viral OTUs were highly abundant at specific time-points, indicating a boom-bust relationship with their host. Most of the viral OTUs were very persistent, which may represent viruses that coexist with their hosts, or able to exploit several host species.

  11. Nitrous oxide emissions from high rate algal ponds treating domestic wastewater.

    Science.gov (United States)

    Alcántara, Cynthia; Muñoz, Raúl; Norvill, Zane; Plouviez, Maxence; Guieysse, Benoit

    2015-02-01

    This study investigated the generation of N2O by microcosms withdrawn from 7-L high rate algal ponds (HRAPs) inoculated with Chlorella vulgaris and treating synthetic wastewater. Although HRAPs microcosms demonstrated the ability to generate algal-mediated N2O when nitrite was externally supplied under darkness in batch assays, negligible N2O emissions rates were consistently recorded in the absence of nitrite during 3.5-month monitoring under 'normal' operation. Thereafter, HRAP A and HRAP B were overloaded with nitrate and ammonium, respectively, in an attempt to stimulate N2O emissions via nitrite in situ accumulation. Significant N2O production (up to 5685±363 nmol N2O/g TSS h) was only recorded from HRAP B microcosms externally supplied with nitrite in darkness. Although confirmation under full-scale outdoors conditions is needed, this study provides the first evidence that the ability of microalgae to synthesize N2O does not affect the environmental performance of wastewater treatment in HRAPs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Some factors effecting algal consumption in subarctic Ephemeroptera, Plecoptera, and Simuliidae

    Energy Technology Data Exchange (ETDEWEB)

    Moore, J.W.

    1977-01-01

    Some of the factors influencing algal consumption in the mayflies Leptophlebia nebulosa, Cinygmula tarda, Baetis foemina and B. cf. bicaudatus, the plecopterans Arcynopteryx signata, Nemoura cinctipes and N. oregonensis and in the dipterans Simulium arcticum, S. venustum and S. decorum were investigated between June 1975 and June 1976 in several streams in the Canadian subarctic. Algae represented up to 65% of the gut contents of L. nebulosa but only 0--8% in the other mayflies. They were important in the plecopterans (85--90%) but less so (2--13%) in the simuliids. Most of the interspecies variability in algal consumption could be explained in terms of food availability. This factor was in turn dependent on the density and attachment characteristics of the flora and the strength of their cell wall. Feeding intensity in most species was low between October and April, reaching it peak in July and August. From 51 to 83% of intraspecies feeding variability was due to changing temperature, followed in importance by water velocity in the dipterans and food availability in the mayflies. All species in this latter group ceased feeding in the final instar stages.

  13. 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.

  14. Algal carbohydrates affect polyketide synthesis of the lichen-forming fungus Cladonia rangiferina.

    Science.gov (United States)

    Elshobary, Mostafa E; Osman, Mohamed E; Abo-Shady, Atef M; Komatsu, Emy; Perreault, Hélène; Sorensen, John; Piercey-Normore, Michele D

    2016-01-01

    Lichen secondary metabolites (polyketides) are produced by the fungal partner, but the role of algal carbohydrates in polyketide biosynthesis is not clear. This study examined whether the type and concentration of algal carbohydrate explained differences in polyketide production and gene transcription by a lichen fungus (Cladonia rangiferina). The carbohydrates identified from a free-living cyanobacterium (Spirulina platensis; glucose), a lichen-forming alga (Diplosphaera chodatii; sorbitol) and the lichen alga that associates with C. rangiferina (Asterochloris sp.; ribitol) were used in each of 1%, 5% and 10% concentrations to enrich malt yeast extract media for culturing the mycobiont. Polyketides were determined by high performance liquid chromatography (HPLC), and polyketide synthase (PKS) gene transcription was measured by quantitative PCR of the ketosynthase domain of four PKS genes. The lower concentrations of carbohydrates induced the PKS gene expression where ribitol up-regulated CrPKS1 and CrPKS16 gene transcription and sorbitol up-regulated CrPKS3 and CrPKS7 gene transcription. The HPLC results revealed that lower concentrations of carbon sources increased polyketide production for three carbohydrates. One polyketide from the natural lichen thallus (fumarprotocetraric acid) also was produced by the fungal culture in ribitol supplemented media only. This study provides a better understanding of the role of the type and concentration of the carbon source in fungal polyketide biosynthesis in the lichen Cladonia rangiferina. © 2016 by The Mycological Society of America.

  15. 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.

  16. Toxicity of Nickel Oxide Nanoparticles on a Freshwater Green Algal Strain of Chlorella vulgaris

    Directory of Open Access Journals (Sweden)

    Abdallah Oukarroum

    2017-01-01

    Full Text Available A freshwater microalga strain of Chlorella vulgaris was used to investigate toxic effects induced by nickel oxide nanoparticles (NiO-NPs in suspension. Algal cells were exposed during 96 h to 0–100 mg L−1 of NiO-NPs and analyzed by flow cytometry. Physicochemical characterization of nanoparticles in tested media showed a soluble fraction (free Ni2+ of only 6.42% for 100 mg L−1 of NiO-NPs, indicating the low solubility capacity of these NPs. Toxicity analysis showed cellular alterations which were related to NiO-NPs concentration, such as inhibition in cell division (relative cell size and granularity, deterioration of the photosynthetic apparatus (chlorophyll synthesis and photochemical reactions of photosynthesis, and oxidative stress (ROS production. The change in cellular viability demonstrated to be a very sensitive biomarker of NiO-NPs toxicity with EC50 of 13.7 mg L−1. Analysis by TEM and X-ray confirmed that NiO-NPs were able to cross biological membranes and to accumulate inside algal cells. Therefore, this study provides a characterization of both physicochemical and toxicological properties of NiO-NPs suspensions in tested media. The use of the freshwater strain of C. vulgaris demonstrated to be a sensitive bioindicator of NiO-NPs toxicity on the viability of green algae.

  17. Biomass recycle as a means to improve the energy efficiency of CELSS algal culture systems

    Science.gov (United States)

    Radmer, R.; Cox, J.; Lieberman, D.; Behrens, P.; Arnett, K.

    1987-01-01

    Algal cultures can be very rapid and efficient means to generate biomass and regenerate the atmosphere for closed environmental life support systems. However, as in the case of most higher plants, a significant fraction of the biomass produced by most algae cannot be directly converted to a useful food product by standard food technology procedures. This waste biomass will serve as an energy drain on the overall system unless it can be efficiently recycled without a significant loss of its energy content. Experiments are reported in which cultures of the alga Scenedesmus obliquus were grown in the light and at the expense of an added carbon source, which either replaced or supplemented the actinic light. As part of these experiments, hydrolyzed waste biomass from these same algae were tested to determine whether the algae themselves could be made part of the biological recycling process. Results indicate that hydrolyzed algal (and plant) biomass can serve as carbon and energy sources for the growth of these algae, suggesting that the efficiency of the closed system could be significantly improved using this recycling process.

  18. Plant Growth Biostimulants, Dietary Feed Supplements and Cosmetics Formulated with Supercritical CO2 Algal Extracts

    Directory of Open Access Journals (Sweden)

    Izabela Michalak

    2017-01-01

    Full Text Available 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 utilitarian properties of the extract-based products. The extracts were analysed for the presence of biologically active molecules (e.g., plant hormones, polyphenols which provide useful properties such as antioxidant, antiviral, anti-inflammatory and antibacterial. The bio-products were tested in germination tests and underwent field trials to search for plant growth biostimulatory properties. Tests on animals (laying hens experiments were conducted to assess pro-health properties of new dietary feed supplement. Another application were cosmetic formulations (dermatological tests. The results of the application tests were very promising, however further studies are required for the registration of the products and successful implementation to the market.

  19. Algal Diet of Small-Bodied Crustacean Zooplankton in a Cyanobacteria-Dominated Eutrophic Lake.

    Directory of Open Access Journals (Sweden)

    Ilmar Tõnno

    Full Text Available Small-bodied cladocerans and cyclopoid copepods are becoming increasingly dominant over large crustacean zooplankton in eutrophic waters where they often coexist with cyanobacterial blooms. However, relatively little is known about their algal diet preferences. We studied grazing selectivity of small crustaceans (the cyclopoid copepods Mesocyclops leuckarti, Thermocyclops oithonoides, Cyclops kolensis, and the cladocerans Daphnia cucullata, Chydorus sphaericus, Bosmina spp. by liquid chromatographic analyses of phytoplankton marker pigments in the shallow, highly eutrophic Lake Võrtsjärv (Estonia during a seasonal cycle. Copepods (mainly C. kolensis preferably consumed cryptophytes (identified by the marker pigment alloxanthin in gut contents during colder periods, while they preferred small non-filamentous diatoms and green algae (identified mainly by diatoxanthin and lutein, respectively from May to September. All studied cladoceran species showed highest selectivity towards colonial cyanobacteria (identified by canthaxanthin. For small C. sphaericus, commonly occuring in the pelagic zone of eutrophic lakes, colonial cyanobacteria can be their major food source, supporting their coexistence with cyanobacterial blooms. Pigments characteristic of filamentous cyanobacteria and diatoms (zeaxanthin and fucoxanthin, respectively, algae dominating in Võrtsjärv, were also found in the grazers' diet but were generally avoided by the crustaceans commonly dominating the zooplankton assemblage. Together these results suggest that the co-occurring small-bodied cyclopoid and cladoceran species have markedly different algal diets and that the cladocera represent the main trophic link transferring cyanobacterial carbon to the food web in a highly eutrophic lake.

  20. Biofouling in capillary and spiral wound membranes facilitated by marine algal bloom

    KAUST Repository

    Villacorte, L.O.

    2017-10-11

    Algal-derived organic matter (AOM), particularly transparent exopolymer particles, has been suspected to facilitate biofilm development in membrane systems (e.g., seawater reverse osmosis). This study demonstrates the possible role of AOM on biofouling in membrane systems affected by marine algal blooms. The tendency of AOM from bloom-forming marine algae to adhere to membranes and its ability to enhance biofilm growth were measured using atomic force microscopy, flow cytometry, liquid chromatography and accelerated membrane biofouling experiments. Adhesion force measurements indicate that AOM tends to adhere to clean membranes and even more strongly to AOM-fouled membranes. Batch growth tests illustrate that the capacity of seawater to support bacterial growth can significantly increase with AOM concentration. Biofouling experiments with spiral wound and capillary membranes illustrate that when nutrients availability are not limited in the feed water, a high concentration of AOM – whether in suspension or attached to the membrane – can substantially accelerates biofouling. A significantly lower biofouling rate was observed on membranes exposed to feed water spiked only with AOM or easily biodegradable nutrients. The abovementioned findings indicate that AOM facilitates the onset of membrane biofouling primarily as a conditioning platform and to some extent as a nutrient source for biofilm-forming bacteria.

  1. MODELING AND ANALYSIS OF ALGAL BLOOMS IN ARAS DAM BY ARTIFICIAL NEURAL NETWORK

    Directory of Open Access Journals (Sweden)

    JAHANGIRI-RAD MAHSA

    2015-03-01

    Full Text Available Man made practices have contributed to large-scale algal blooms that have caused serious ecological, aesthetic, water purification and water distribution problems. Aras Dam, which provides Arasful city with drinking water, has chronic algal blooms since 1990. This study addresses the use of artificial neural network (ANN model to anticipate the chlorophyll-a concentration in water of dam reservoir. Operation tests carried out by collecting water samples from 5 stations and examined for physical quality parameters namely: water temperature, total suspended solids (TSS, biochemical oxygen demands (BOD, ortophosphate, total phosphorous and nitrate concentrations using standard methods. Chlorophyll-a was also checked separately in order to investigate the accuracy of the predicted results by ANN. The results showed that a network was highly accurate in predicting the Chl-a concentration. A good agreement between actual data and the ANN outputs for training was observed, indicating the validation of testing data sets. The initial results of the research indicate that the dam is enriched with nutrients (phosphorus and nitrogen. The Chl-a concentration that were predicted by the model were beyond the standard levels; indicating the possibility of eutrophication especially during fall season.

  2. Effects of three pharmaceutical and personal care products on natural freshwater algal assemblages.

    Science.gov (United States)

    Wilson, Brittan A; Smith, Val H; deNoyelles, Frank; Larive, Cynthia K

    2003-05-01

    Treated wastewaters in the United States contain detectable quantities of surfactants, antibiotics, and other types of antimicrobial chemicals contained in pharmaceutical and personal-care products (PPCPs) that are released into stream ecosystems. The degradation characteristics of many of these chemicals are not yet known, nor are the chemical properties of their byproducts. They also are not currently mandated for removal under the U.S. Clean Water Act. Three representative PPCPs were individually tested in this study using a series of laboratory dilution bioassays: Ciprofloxacin (an antibiotic), Triclosan (an antimicrobial agent), and Tergitol NP 10 (a surfactant), to determine their effects on natural algal communities sampled both upstream and downstream of the Olathe, KS wastewater treatment plant (WWTP). There were no significant treatment effects on algal community growth rates during the exponential phase of growth, but significant differences were observed in the final biomass yields (p WWTP effluents. These changes could result in shifts in both the nutrient processing capacity and the natural food web structure of these streams.

  3. Abrupt stop of deep water turnover with lake warming: Drastic consequences for algal primary producers.

    Science.gov (United States)

    Yankova, Yana; Neuenschwander, Stefan; Köster, Oliver; Posch, Thomas

    2017-10-23

    After strong fertilization in the 20 th century, many deep lakes in Central Europe are again nutrient poor due to long-lasting restoration (re-oligotrophication). In line with reduced phosphorus and nitrogen loadings, total organismic productivity decreased and lakes have now historically low nutrient and biomass concentrations. This caused speculations that restoration was overdone and intended fertilizations are needed to ensure ecological functionality. Here we show that recent re-oligotrophication processes indeed accelerated, however caused by lake warming. Rising air temperatures strengthen thermal stabilization of water columns which prevents thorough turnover (holomixis). Reduced mixis impedes down-welling of oxygen rich epilimnetic (surface) and up-welling of phosphorus and nitrogen rich hypolimnetic (deep) water. However, nutrient inputs are essential for algal spring blooms acting as boost for annual food web successions. We show that repeated lack (since 1977) and complete stop (since 2013) of holomixis caused drastic epilimnetic phosphorus depletions and an absence of phytoplankton spring blooms in Lake Zurich (Switzerland). By simulating holomixis in experiments, we could induce significant vernal algal blooms, confirming that there would be sufficient hypolimnetic phosphorus which presently accumulates due to reduced export. Thus, intended fertilizations are highly questionable, as hypolimnetic nutrients will become available during future natural or artificial turnovers.

  4. Effects of Nano-Titanium Dioxide on Freshwater Algal Population Dynamics

    Science.gov (United States)

    Kulacki, Konrad J.; Cardinale, Bradley J.

    2012-01-01

    To make predictions about the possible effects of nanomaterials across environments and taxa, toxicity testing must incorporate not only a variety of organisms and endpoints, but also an understanding of the mechanisms that underlie nanoparticle toxicity. Here, we report the results of a laboratory experiment in which we examined how titanium dioxide nanoparticles impact the population dynamics and production of biomass across a range of freshwater algae. We exposed 10 of the most common species of North American freshwater pelagic algae (phytoplankton) to five increasing concentrations of n-TiO2 (ranging from controls to 300 mg n-TiO2 L−1). We then examined the effects of n-TiO2 on the population growth rates and biomass production of each algal species over a period of 25 days. On average, increasing concentrations of n-TiO2 had no significant effects on algal growth rates (p = 0.376), even though there was considerable species-specific variation in responses. In contrast, exposure to n-TiO2 tended to increase maximum biomass achieved by species in culture (p = 0.06). Results suggest that titanium dioxide nanoparticles could influence certain aspects of population growth of freshwater phytoplankton, though effects are unlikely at environmentally relevant concentrations. PMID:23071735

  5. Biofouling in capillary and spiral wound membranes facilitated by marine algal bloom

    KAUST Repository

    Villacorte, L.O.; Ekowati, Y.; Calix-Ponce, H.N.; Kisielius, V.; Kleijn, J.M.; Vrouwenvelder, Johannes S.; Schippers, J.C.; Kennedy, M.D.

    2017-01-01

    Algal-derived organic matter (AOM), particularly transparent exopolymer particles, has been suspected to facilitate biofilm development in membrane systems (e.g., seawater reverse osmosis). This study demonstrates the possible role of AOM on biofouling in membrane systems affected by marine algal blooms. The tendency of AOM from bloom-forming marine algae to adhere to membranes and its ability to enhance biofilm growth were measured using atomic force microscopy, flow cytometry, liquid chromatography and accelerated membrane biofouling experiments. Adhesion force measurements indicate that AOM tends to adhere to clean membranes and even more strongly to AOM-fouled membranes. Batch growth tests illustrate that the capacity of seawater to support bacterial growth can significantly increase with AOM concentration. Biofouling experiments with spiral wound and capillary membranes illustrate that when nutrients availability are not limited in the feed water, a high concentration of AOM – whether in suspension or attached to the membrane – can substantially accelerates biofouling. A significantly lower biofouling rate was observed on membranes exposed to feed water spiked only with AOM or easily biodegradable nutrients. The abovementioned findings indicate that AOM facilitates the onset of membrane biofouling primarily as a conditioning platform and to some extent as a nutrient source for biofilm-forming bacteria.

  6. Great Lakes Hyperspectral Water Quality Instrument Suite for Airborne Monitoring of Algal Blooms

    Science.gov (United States)

    Lekki, John; Leshkevich, George; Nguyen, Quang-Viet; Flatico, Joseph; Prokop, Norman; Kojima, Jun; Anderson, Robert; Demers, James; Krasowski, Michael

    2007-01-01

    NASA Glenn Research Center and NOAA Great Lakes Environmental Research Lab are collaborating to utilize an airborne hyperspectral imaging sensor suite to monitor Harmful Algal Blooms (HABs) in the western basin of Lake Erie. The HABs are very dynamic events as they form, spread and then disappear within a 4 to 8 week time period in late summer. They are a concern for human health, fish and wildlife because they can contain blue green toxic algae. Because of this toxicity there is a need for the blooms to be continually monitored. This situation is well suited for aircraft based monitoring because the blooms are a very dynamic event and they can spread over a large area. High resolution satellite data is not suitable by itself because it will not give the temporal resolution due to the infrequent overpasses of the quickly changing blooms. A custom designed hyperspectral imager and a point spectrometer mounted on aT 34 aircraft have been used to obtain data on an algal bloom that formed in the western basin of Lake Erie during September 2006. The sensor suite and operations will be described and preliminary hyperspectral data of this event will be presented

  7. Influence of algal diet on feeding and egg-production of the calanoid copepod Acartia tonsa Dana

    DEFF Research Database (Denmark)

    Støttrup, Josianne; Jensen, Johanne

    1990-01-01

    Threshold concentration, retention efficiency and egg-production in the calanoid copepod Acartia tonsa Dana were examined using the algal species Isochrysis galbana clone T-iso, Dunalietta tertiolecta Butcher, Rhodomonas baltica Karsten, Ditylum brightwellii Grunow and Thalassiosira weissflogii...... Grun. Feeding and egg-production in A. tonsa was shown to be influenced by the size, quantity and quality of the food particles. The small I. galbana (4.8 μm) were inefficiently retained by A. tonsa and maximum ingestion rates on this species were first obtained at algal concentrations s> 1 μg C · ml−1...

  8. Chromium and zinc uptake by algae Gelidium and agar extraction algal waste: kinetics and equilibrium.

    Science.gov (United States)

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

    2007-11-19

    Biosorption of chromium and zinc 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). Langmuir and Langmuir-Freundlich equilibrium models describe well the equilibrium data. The parameters of Langmuir equilibrium model at pH 5.3 and 20 degrees C were for the algae, q(L)=18 mg Cr(III)g(-1) and 13 mgZn(II)g(-1), K(L) = 0.021l mg(-1)Cr(III) and 0.026l mg(-1) Zn(II); for the algal waste, q(L)=12 mgCr(III)g(-1) and 7mgZn(II)g(-1), K(L)=0.033lmg(-1) Cr(III) and 0.042l mg(-1) Zn(II); for the composite material, q(L) = 9 mgCr(III)g(-1) and 6 mgZn(II)g(-1), K(L)=0.032l mg(-1)Cr(III) and 0.034l mg(-1)Zn(II). The biosorbents exhibited a higher preference for Cr(III) ions and algae Gelidium is the best one. The pseudo-first-order Lagergren and pseudo-second-order models fitted well the kinetic data for the two metal ions. Kinetic constants and equilibrium uptake concentrations given by the pseudo-second-order model for an initial Cr(III) and Zn(II) concentration of approximately 100 mgl(-1), at pH 5.3 and 20 degrees C were k(2,ads)=0.04 g mg(-1)Cr(III)min(-1) and 0.07 g mg(-1)Zn(II)min(-1), q(eq)=11.9 mgCr(III)g(-1) and 9.5 mgZn(II)g(-1) for algae; k(2,ads)=0.17 g mg(-1)Cr(III)min(-1) and 0.19 g mg(-1)Zn(II)min(-1), q(eq)=8.3 mgCr(III)g(-1) and 5.6 mgZn(II)g(-1) for algal waste; k(2,ads)=0.01 g mg(-1)Cr(III)min(-1) and 0.18 g mg(-1)Zn(II)min(-1), q(eq)=8.0 mgCr(III)g(-1) and 4.4 mgZn(II)g(-1) for composite material. Biosorption was modelled using a batch adsorber mass transfer kinetic model, which successfully predicts Cr(III) and Zn(II) concentration profiles. The calculated average homogeneous diffusivities, D(h), were 4.2 x 10(-8), 8.3 x 10(-8) and 1.4 x 10(-8)cm(2)s(-1) for Cr(III) and 4.8 x 10(-8), 9.7 x 10(-8) and 6.2 x 10(-8)cm(2)s(-1

  9. Physical and biological data collected along the Texas, Mississippi, and Florida Gulf coasts in the Gulf of Mexico as part of the Harmful Algal BloomS Observing System from 19 Aug 1953 to 11 July 2014 (NODC Accession 0120767)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — HABSOS (Harmful Algal BloomS Observing System) is a data collection and distribution system for harmful algal bloom (HAB) information in the Gulf of Mexico. The goal...

  10. Occurrence of marine algal toxins in oyster and phytoplankton samples in Daya Bay, South China Sea.

    Science.gov (United States)

    Jiang, Tao; Liu, Lei; Li, Yang; Zhang, Jing; Tan, Zhijun; Wu, Haiyan; Jiang, Tianjiu; Lu, Songhui

    2017-09-01

    The occurrence and seasonal variations of marine algal toxins in phytoplankton and oyster samples in Daya Bay (DYB), South China Sea were investigated. Two Dinophysis species, namely, D. caudata and D. acuminata complex, were identified as Okadaic acid (OA)/pectenotoxin (PTX) related species. Liquid chromatography with tandem mass spectrometry (LC-MS/MS) analysis demonstrated that 2.04-14.47 pg PTX2 per cell was the predominant toxin in single-cell isolates of D. caudata. D. acuminata was not subjected to toxin analysis. The occurrence of OAs in phytoplankton concentrates of net-haul sample coincided with the presence of D. accuminata complex, suggesting that this species is most likely an OA producer in this sea area. OA, dinophysistoxins-1 (DTX1), PTX2, PTX2sa, gymnodimine (GYM), homoyessotoxin (homoYTX), and domoic acid (DA) demonstrated positive results in net haul samples. To our best knowledge, this paper is the first to report the detection of GYM, DA, and homoYTX in phytoplankton samples in Chinese coastal waters. Among the algal toxins, GYM demonstrated the highest frequency of positive detections in phytoplankton concentrates (13/17). Five compounds of algal toxins, including OA, DTX1, PTX2, PTX2sa, and GYM, were detected in oyster samples. DA and homoYTX were not detected in oysters despite of positive detections for both in the phytoplankton concentrates. However, neither the presence nor absence of DA in oysters can be determined because extraction conditions with 100% methanol used to isolate toxins from oysters (recommended by the EU-Harmonised Standard Operating Procedure, 2015) would likely be unsuitable for this water-soluble toxin. In addition, transformation of DA during the digestion process of oysters may also be involved in the negative detections of this toxin. GYM exhibited the highest frequency of positive results in oysters (14/17). OAs were only detected in the hydrolyzed oyster samples. The detection rates of PTX and PTX2sa in

  11. Water Quality and Algal Data for the North Umpqua River Basin, Oregon, 2005

    Science.gov (United States)

    Tanner, Dwight Q.; Arnsberg, Andrew J.; Anderson, Chauncey W.; Carpenter, Kurt D.

    2006-01-01

    The upper North Umpqua River Basin has experienced a variety of water-quality problems since at least the early 1990's. Several reaches of the North Umpqua River are listed as water-quality limited under section 303(d) of the Clean Water Act. Diamond Lake, a eutrophic lake that is an important source of water and nutrients to the upper North Umpqua River, is also listed as a water-quality limited waterbody (pH, nuisance algae). A draft Total Maximum Daily Load (TMDL) was proposed for various parameters and is expected to be adopted in full in 2006. Diamond Lake has supported potentially toxic blue-green algae blooms since 2001 that have resulted in closures to recreational water contact and impacts to the local economy. Increased populations of the invasive tui chub fish are reportedly responsible, because they feed on zooplankton that would otherwise control the algal blooms. The Final Environmental Impact Statement (FEIS) for the Diamond Lake Restoration Project advocates reduced fish biomass in Diamond Lake in 2006 as the preferred alternative. A restoration project scheduled to reduce fish biomass for the lake includes a significant water-level drawdown that began in January 2006. After the drawdown of Diamond Lake, the fish toxicant rotenone was applied to eradicate the tui chub. The lake will be refilled and restocked with game fish in 2007. Winter exports of nutrients from Diamond Lake during the restoration project could affect the summer trophic status of the North Umpqua River if retention and recycling in Lemolo Lake are significant. The FEIS includes comprehensive monitoring to assess the water quality of the restored Diamond Lake and the effects of that restoration downstream. One component of the monitoring is the collection of baseline data, in order to observe changes in the river's water quality and algal conditions resulting from the restoration of Diamond Lake. During July 2005, the USGS, in cooperation with Douglas County, performed a synoptic

  12. Diversity of algal endosymbionts (zooxanthellae) in octocorals: the roles of geography and host relationships.

    Science.gov (United States)

    Van Oppen, M J H; Mieog, J C; Sánchez, C A; Fabricius, K E

    2005-07-01

    The presence, genetic identity and diversity of algal endosymbionts (Symbiodinium) in 114 species from 69 genera (20 families) of octocorals from the Great Barrier Reef (GBR), the far eastern Pacific (EP) and the Caribbean was examined, and patterns of the octocoral-algal symbiosis were compared with patterns in the host phylogeny. Genetic analyses of the zooxanthellae were based on ribosomal DNA internal transcribed spacer 1 (ITS1) region. In the GBR samples, Symbiodinium clades A and G were encountered with A and G being rare. Clade B zooxanthellae have been previously reported from a GBR octocoral, but are also rare in octocorals from this region. Symbiodinium G has so far only been found in Foraminifera, but is rare in these organisms. In the Caribbean samples, only Symbiodinium clades B and C are present. Hence, Symbiodinium diversity at the level of phylogenetic clades is lower in octocorals from the Caribbean compared to those from the GBR. However, an unprecedented level of ITS1 diversity was observed within individual colonies of some Caribbean gorgonians, implying either that these simultaneously harbour multiple strains of clade B zooxanthellae, or that ITS1 heterogeneity exists within the genomes of some zooxanthellae. Intracladal diversity based on ITS should therefore be interpreted with caution, especially in cases where no independent evidence exists to support distinctiveness, such as ecological distribution or physiological characteristics. All samples from EP are azooxanthellate. Three unrelated GBR taxa that are described in the literature as azooxanthellate (Junceella fragilis, Euplexaura nuttingi and Stereonephthya sp. 1) contain clade G zooxanthellae, and their symbiotic association with zooxanthellae was confirmed by histology. These corals are pale in colour, whereas related azooxanthellate species are brightly coloured. The evolutionary loss or gain of zooxanthellae may have altered the light sensitivity of the host tissues, requiring the

  13. POTENŢIALUL NUTRIŢIONAL AL BIOMASEI ALGALE DE NOSTOC FLAGELLIFORME (BERK ET CURT ELENK.

    Directory of Open Access Journals (Sweden)

    Irina STRATULAT

    2016-05-01

    Full Text Available În prezentul studiu este prezentată componenţa biochimică a biomasei algei cianofite Nostoc flagelli­forme (Berk et Curt Elenk. cultivată în condiţii de laborator pe mediul mineral Z-8. Biomasa algei conţine: Mn – 683,9 mg/kg, Zn – 131,5 mg/kg, Pb – <10 mg/kg, Fe – 1,09 g/kg, Na+ – 2,10 g/kg, K+ – 8,01 g/kg, Mg 2+ – 5,40 g/kg, Ca2+ – 7,94 g/kg. În componenţa aminoacizilor predomină: acidul glutamic – 3,8012 mg/100 mg, acidul aspartic – 2,7838 mg/100 mg, leucina – 2,4651 mg/100 mg, alanina – 2,3513 mg/100 mg. Conform acestor rezultate, biomasa algei cianofite Nostoc flagelliforme poate fi utilizată ca sursă importantă de supli­mente alimentare. THE NUTRITIONAL POTENTIAL OF ALGAL BIOMASS OF NOSTOC FLAGELLIFORME (BERK ET CURT ELENK. In this study is presented the biochemical components of algal biomass Nostoc flagelliforme (Berk et Curt Elenk. cultivated in laboratory conditions in Z-8 medium. The algal biomass has the following chemical content: Mn – 683,9 mg/kg, Zn – 131,5 mg/kg, Pb – <10 mg/kg, Fe – 1,09 g/kg, Na+ - 2,10 g/kg, K+ – 8,01 g/kg, Mg2+ – 5,40 g/kg, Ca2+ – 7,94 g/kg. The highest amount of amino acids are specific for: glutamic acid – 3,8012 mg/100 mg, aspartic acid – 2,7838 mg/100 mg, leucine – 2,4651 mg/100 mg, alanine – 2,3513 mg/100 mg. According to these results the blue-green alga Nostoc flagelliforme can be considered an important potential source of nutritional supplements. 

  14. The effects of particles and dissolved materials on in situ algal pigment fluorescence sensors

    Science.gov (United States)

    Saraceno, J.; Bergamaschi, B. A.; Downing, B. D.

    2013-12-01

    Field deployable sensors that measure algal pigment fluorescence (APF), such as chlorophyll-a (excitation/emission ca. 470/685 nm), and phycocyanin (ca. 590/685 nm), have been used to estimate algal biomass and study food-web dynamics in coastal and oceanic waters for many years. There is also widespread use of these sensors in real time river-observing networks. However, freshwater systems often possess elevated levels of suspended solids and dissolved organic material that can interfere with optical measurements. Data collected under conditions that result in interferences may not be comparable across time and between sites unless the data are appropriately corrected. Using standard reference materials and a surrogate for algal fluorescence (Rhodamine WT), lab experiments were conducted on several commercially available sensors to quantify sensitivity to interferences over a range of naturally occurring surface water conditions (DOC : 0-30 mg/L and turbidity: 0- 1000 FNU ). Chlorophyll-a sensors exhibited a slight but significant positive bias (2 mg/L, with signal quenching reaching a maximum of 15% at 30 mg/L DOC. All phycocyanin sensors displayed a positive non-linear bias with DOC concentration, reaching a maximum of 40% difference at 30 mg/L DOC. Both chlorophyll-a and phycocyanin sensors showed a positive linear relationship with suspended solids concentration (as indicated by turbidity).The effect of suspended solids on APF output can be explained by the detection of scattered excitation light (leaking through emission filters). Similar qualitative effects were observed for the sensors tested, though the magnitude of the effect varied among sensor type. This indicates that differences in sensor designs such as geometry, wavelength and signal post processing techniques is related to its sensitivity to interferences. Although sensors exhibited significant cross sensitivity to interferences, our results indicate that simple corrections can largely remove

  15. Effect of a dam on epilithic algal communities of a mountain stream: before-after dam construction comparison

    Directory of Open Access Journals (Sweden)

    Luciana Cibils Martina

    2013-02-01

    Full Text Available In this study we evaluated the effect of a dam on epilithic algal communities by analyzing community response after dam construction and by comparing community composition, structure and biomass upstream and downstream of the dam. Samples of epilithic algae and environmental data were collected at each site during high and low water periods before and after dam construction in Achiras Stream (Córdoba, Argentina. Ordinations showed modifications in algal assemblages after dam construction and downstream of the dam. Ordinations also suggested a loss of seasonality at the downstream site since the assemblages were similar between hydrological periods after dam construction. Indicator species, obtained by the Indicator Value method, showed that, after dam construction, there could have been an increase in nutrient concentration and a release of plankton from the impoundment. Abundance, richness and diversity were altered after dam construction as assessed by ANOVAs derived from a modified BACI Design. Proportion of early-successional species was higher at the upstream site while late-successional species were dominant at the downstream site, as predicted. Lower fluctuations in discharge downstream of the dam may have helped succession advance, whereas at the upstream site, mainly during the high water period, floods could have caused sloughing of life forms from the outer layers of the biofilm, resetting the algal community to early successional stages. It may be concluded that the dam affected algal community and favored succession advance mainly by reducing current velocity and flow fluctuations.

  16. 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.

  17. Using Ocean Color Satellite Data to Estimate Economics Benefits Associated with Monitoring and Preventing Harmful Algal Blooms

    Science.gov (United States)

    This presentation describes preliminary work that is underway that will illustrate the use of ocean land colour instrument data (Sentinel-3 & Landsat) to detect and monitor harmful algal blooms (HABS) in freshwater lakes for two types of economic analyses. This project is a j...

  18. Process Design and Economics for the Conversion of Algal Biomass to Hydrocarbons: Whole Algae Hydrothermal Liquefaction and Upgrading

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Susanne B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zhu, Yunhua [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Anderson, Daniel B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hallen, Richard T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Elliott, Douglas C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Schmidt, Andrew J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Albrecht, Karl O. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hart, Todd R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Butcher, Mark G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Drennan, Corinne [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Snowden-Swan, Lesley J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Davis, Ryan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kinchin, Christopher [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2014-03-20

    This report provides a preliminary analysis of the costs associated with converting whole wet algal biomass into primarily diesel fuel. Hydrothermal liquefaction converts the whole algae into an oil that is then hydrotreated and distilled. The secondary aqueous product containing significant organic material is converted to a medium btu gas via catalytic hydrothermal gasification.

  19. Formation of Emerging Disinfection By-products by Chlorination/Chloramination of Seawater Impacted by Algal Organic Matter

    KAUST Repository

    Nihemaiti, Maolida

    2015-08-31

    The aim of this work was to study the formation of haloacetamides (HAcAms) and other DBPs during chlorination and chloramination of algal organic matter (AlOM). The HAcAms formation potentials of different precursors (amino acids, simulated algal blooms grown in the Red Sea) were evaluated. Experiments with simulated algal blooms were conducted in the presence of bromide ion (synthetic seawater containing 800 μg/L Br−) to assess the formation of brominated analogues of HAcAms in conditions close to the disinfection of real seawater. Chlorination produced more HAcAms than chloramination from real algae (Synecococcus sp.), thus indicating that the nitrogen of HAcAms comes predominantly from DON through the decarboxylation of amino acids rather than from NH2Cl. Dibrominated species of DBPs (i.e., DBAcAm, DBAA and DBAN) were the dominant species formed by both chlorination and chloramination of algal bloom samples. Chloramination of the amino acid asparagine produced an important amount of DCAcAm as compared to chlorination, indicating the existence of a specific reaction pathway.

  20. Formation of Emerging Disinfection By-products by Chlorination/Chloramination of Seawater Impacted by Algal Organic Matter

    KAUST Repository

    Nihemaiti, Maolida; Le Roux, Julien; Croue, Jean-Philippe

    2015-01-01

    The aim of this work was to study the formation of haloacetamides (HAcAms) and other DBPs during chlorination and chloramination of algal organic matter (AlOM). The HAcAms formation potentials of different precursors (amino acids, simulated algal blooms grown in the Red Sea) were evaluated. Experiments with simulated algal blooms were conducted in the presence of bromide ion (synthetic seawater containing 800 μg/L Br−) to assess the formation of brominated analogues of HAcAms in conditions close to the disinfection of real seawater. Chlorination produced more HAcAms than chloramination from real algae (Synecococcus sp.), thus indicating that the nitrogen of HAcAms comes predominantly from DON through the decarboxylation of amino acids rather than from NH2Cl. Dibrominated species of DBPs (i.e., DBAcAm, DBAA and DBAN) were the dominant species formed by both chlorination and chloramination of algal bloom samples. Chloramination of the amino acid asparagine produced an important amount of DCAcAm as compared to chlorination, indicating the existence of a specific reaction pathway.

  1. 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

  2. Experimental study on the interspecific interactions between the two bloom-forming algal species and the rotifer Brachionus plicatilis

    Science.gov (United States)

    Xie, Zhihao; Xiao, Hui; Tang, Xuexi; Cai, Hengjiang

    2009-06-01

    The interspecific interactions between the rotifer Brachionus plicatilis and two harmful algal blooms (HAB) species were investigated experimentally by single culture method. B. plicatilis population and the growth of the two algae were compared at different algal cell densities. The results demonstrated that the B. plicatilis obtained sufficient nutrition from Prorocentrum donghaiense to support net population increase. With exposure to 2.5×104 cells mL-1 of P. donghaiense, the number of B. plicatilis increased faster than it did when exposed to other four algal densities (5, 10, 15 and 20 ×104 cells mL-1), and the increase rate of B. plicatilis population ( r) at this algal density was 0.104 ± 0.015 rd-1. Cell densities of P. donghaiense decreased due to the grazing of B. plicatilis. In contrast, Heterosigma akashiwo had an adverse effect on B. plicatilis population and its growth was largely unaffected by rotifer grazing. In this case, B. plicatilis population decreased and H. akashiwo grew at a rate similar to that of the control.

  3. Climate Change Impacts on Harmful Algal Blooms in U.S. Freshwaters: A Screening-Level Assessment

    Science.gov (United States)

    Cyanobacterial harmful algal blooms have serious adverse effects on human and environmental health. Herein, we develop a modeling framework that predicts the effect of climate change on cyanobacteria concentrations in reservoirs in the contiguous U.S. The framework, which uses cl...

  4. MF/UF rejection and fouling potential of algal organic matter from bloom-forming marine and freshwater algae

    KAUST Repository

    Villacorte, Loreen O.

    2015-07-01

    Pretreatment with microfiltration (MF) or ultrafiltration (UF) membranes has been proposed for seawater reverse osmosis (SWRO) plants to address operational issues associated with algal blooms. Here, we investigated the MF/UF rejection and fouling potential of algal organic matter (AOM) released by common species of bloom-forming marine (Alexandrium tamarense and Chaetoceros affinis) and freshwater (Microcystis sp.) algae. Batch culture monitoring of the three algal species illustrated varying growth pattern, cell concentration, AOM released and membrane fouling potential. The high membrane fouling potential of the cultures can be directly associated (R2>0.85) with AOM such as transparent exopolymer particle (TEP) while no apparent relationship with algal cell concentration was observed. The AOM comprised mainly biopolymers (e.g., polysaccharides and proteins) and low molecular weight organic compounds (e.g., humic-like substances). The former were largely rejected by MF/UF membranes while the latter were poorly rejected. MF (0.4μm and 0.1μm pore size) rejected 14%-56% of biopolymers while conventional UF (100kDa) and tight UF (10kDa) rejected up to 83% and 97%, respectively. The retention of AOM resulted in a rapid increase in trans-membrane pressure (δP) over time, characterised by pore blocking followed by cake filtration with enhanced compression as illustrated by an exponential progression of δP. © 2015 Elsevier B.V.

  5. Effects of nutrient trace metal speciation on algal growth in the presence of the chelator [S,S]-EDDS

    NARCIS (Netherlands)

    Schowanek, D.; McAvoy, D.; Versteeg, D.; Hanstveit, A.

    1996-01-01

    This study tests the hypothesis that the apparent toxicity of strong chelators in standard algal growth inhibition tests (e.g. method OECD 201, EC C.3., ISO 8692) is related to essential trace metal bioavailability. This hypothesis was investigated for the chelator [S,S]-ethylene diamine disuccinate

  6. The significance of spatial and temporal patterns of algal mat deposition in structuring salt-marsh vegetation

    NARCIS (Netherlands)

    Van Soelen, J.; Herman, P.M.J.; Bouma, T.J.

    2006-01-01

    Question: Are there hot spots of algal mat deposition in space and time at the marsh scale and, if so, how does this affect the coexistence of a dominant (Spartina anglica) and gap dependent (Salicornia europaea) species? Location: The Rattekaai salt marsh in the Scheldt estuary in the southwestern

  7. Effects of different biomass drying and lipid extraction methods on algal lipid yield, fatty acid profile, and biodiesel quality.

    Science.gov (United States)

    Hussain, Javid; Liu, Yan; Lopes, Wilson A; Druzian, Janice I; Souza, Carolina O; Carvalho, Gilson C; Nascimento, Iracema A; Liao, Wei

    2015-03-01

    Three lipid extraction methods of hexane Soxhlet (Sox-Hex), Halim (HIP), and Bligh and Dyer (BD) were applied on freeze-dried (FD) and oven-dried (OD) Chlorella vulgaris biomass to evaluate their effects on lipid yield, fatty acid profile, and algal biodiesel quality. Among these three methods, HIP was the preferred one for C. vulgaris lipid recovery considering both extraction efficiency and solvent toxicity. It had the highest lipid yields of 20.0 and 22.0% on FD and OD biomass, respectively, with corresponding neutral lipid yields of 14.8 and 12.7%. The lipid profiling analysis showed that palmitic, oleic, linoleic, and α-linolenic acids were the major fatty acids in the algal lipids, and there were no significant differences on the amount of these acids between different drying and extraction methods. Correlative models applied to the fatty acid profiles concluded that high contents of palmitic and oleic acids in algal lipids contributed to balancing the ratio of saturated and unsaturated fatty acids and led to a high-quality algal biodiesel.

  8. Algal sludge from Taihu Lake can be utilized to create novel PGPR-containing bio-organic fertilizers.

    Science.gov (United States)

    Zhang, Miao; Li, Rong; Cao, Liangliang; Shi, Juanjuan; Liu, Hongjun; Huang, Yan; Shen, Qirong

    2014-01-01

    Large amounts of refloated algal sludge from Taihu Lake result in secondary environmental pollution due to annual refloatation. This study investigated the possibility to produce bio-organic fertilizer (BIO) using algal sludge as a solid-state fermentation (SSF) medium. Results showed that addition of algal sludge contributed to efficient SFF by a plant growth-promoting rhizobacteria (PGPR) strain SQR9 and improved the nutrient contents in the novel BIO. The optimum water content and initial inoculation size were 45% and 5%, respectively. After 6 days of SSF, the biomass of strain SQR9 was increased to a cell density of more than 5 × 10(7) CFU g(-1). Microcystins were rapidly degraded, and a high germination index value was observed. Plant growth experiments showed that the produced BIO efficiently promoted plant growth. Additional testing showed that the novel SSF process was also suitable for other PGPR strains. This study provides a novel way of high-value utilization of algal sludge from Taihu Lake by producing low-cost but high-quality BIOs. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Phosphate dynamics in an acidic mountain stream: Interactions involving algal uptake, sorption by iron oxide, and photoreduction

    Science.gov (United States)

    Tate, Cathy M.; Broshears, Robert E.; McKnight, Diane M.

    1995-01-01

    Acid mine drainage streams in the Rocky Mountains typically have few algal species and abundant iron oxide deposits which can sorb phosphate. An instream injection of radiolabeled phosphate (32P0,) into St. Kevin Gulch, an acid mine drainage stream, was used to test the ability of a dominant algal species, Ulothrix sp., to rapidly assimilate phosphate. Approximately 90% of the injected phosphate was removed from the water column in the 175-m stream reach. When shaded stream reaches were exposed to full sunlight after the injection ended, photoreductive dissolution of iron oxide released sorbed 32P, which was then also removed downstream. The removal from the stream was modeled as a first-order process by using a reactive solute transport transient storage model. Concentrations of 32P mass-’ of algae were typically lo-fold greater than concentrations in hydrous iron oxides. During the injection, concentrations of 32P increased in the cellular P pool containing soluble, low-molecular-weight compounds and confirmed direct algal uptake of 32P0, from water. Mass balance calculations indicated that algal uptake and sorption on iron oxides were significant in removing phosphate. We conclude that in stream ecosystems, PO, sorbed by iron oxides can act as a dynamic nutrient reservoir regulated by photoreduction.

  10. Detection and characterization of benthic filamentous algal stands (Cladophora sp.) on rocky substrata using a high-frequency echosounder

    Science.gov (United States)

    Depew, David C.; Stevens, Andrew W.; Smith, Ralph E.H.; Hecky, Robert E.

    2009-01-01

    A high-frequency echosounder was used to detect and characterize percent cover and stand height of the benthic filamentous green alga Cladophora sp. on rocky substratum of the Laurentian Great Lakes. Comparisons between in situ observations and estimates of the algal stand characteristics (percent cover, stand height) derived from the acoustic data show good agreement for algal stands that exceeded the height threshold for detection by acoustics (~7.5 cm). Backscatter intensity and volume scattering strength were unable to provide any predictive power for estimating algal biomass. A comparative analysis between the only current commercial software (EcoSAV™) and an alternate method using a graphical user interface (GUI) written in MATLAB® confirmed previous findings that EcoSAV functions poorly in conditions where the substrate is uneven and bottom depth changes rapidly. The GUI method uses a signal processing algorithm similar to that of EcoSAV but bases bottom depth classification and algal stand height classification on adjustable thresholds that can be visualized by a trained analyst. This study documents the successful characterization of nuisance quantities of filamentous algae on hard substrate using an acoustic system and demonstrates the potential to significantly increase the efficiency of collecting information on the distribution of nuisance macroalgae. This study also highlights the need for further development of more flexible classification algorithms that can be used in a variety of aquatic ecosystems.

  11. Laboratory algal bioassays using PAM fluorometry: effects of test conditions on the determination of herbicide and field sample toxicity.

    Science.gov (United States)

    Sjollema, Sascha B; van Beusekom, Sebastiaan A M; van der Geest, Harm G; Booij, Petra; de Zwart, Dick; Vethaak, A Dick; Admiraal, Wim

    2014-05-01

    Pulse Amplitude Modulation (PAM) fluorometry, based on chlorophyll a fluorescence, is a frequently used technique in algal bioassays to assess toxicity of single compounds or complex field samples. Several test conditions can influence the test results, and because a standardized test protocol is currently lacking, linking the results of different studies is difficult. Therefore, the aim of the present study was to gain insight into the effects of test conditions of laboratory algal bioassays using PAM fluorometry on the outcome of toxicity tests. To this purpose, we described the results from several pilot studies on test development in which information is provided on the effects of the main test factors during the pretest phase, the test preparation, the exposure period, and the actual measurement. The experiments were focused on individual herbicides and complex field samples and included the effects of culturing conditions, cell density, solvent concentration, exposure time, and the presence of actinic light. Several of these test conditions were found to influence the outcome of the toxicity test, and the presented information provides important background information for the interpretation of toxicity results and describes which test conditions should be taken into account when using an algal bioassay with PAM fluorometry. Finally, the application of PAM fluorometry in algal toxicity testing is discussed. © 2014 SETAC.

  12. Demonstration of Parallel Algal Processing: Production of Renewable Diesel Blendstock and a High-Value Chemical Intermediate

    Energy Technology Data Exchange (ETDEWEB)

    Knoshaug, Eric P [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Mohagheghi, Ali [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Nagle, Nicholas J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Stickel, Jonathan J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Dong, Tao [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Karp, Eric M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kruger, Jacob S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Brandner, David [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Manker, Lorenz [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rorrer, Nicholas [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hyman, Deborah A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Christensen, Earl D [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Pienkos, Philip T [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-12-19

    Co-production of high-value chemicals such as succinic acid from algal sugars is a promising route to enabling conversion of algal lipids to a renewable diesel blendstock. Biomass from the green alga Scenedesmus acutus was acid pretreated and the resulting slurry separated into its solid and liquor components using charged polyamide induced flocculation and vacuum filtration. Over the course of a subsequent 756 hours continuous fermentation of the algal liquor with Actinobacillus succinogenes 130Z, we achieved maximum productivity, process conversion yield, and titer of 1.1 g L-1 h-1, 0.7 g g-1 total sugars, and 30.5 g L-1 respectively. Succinic acid was recovered from fermentation media with a yield of 60% at 98.4% purity while lipids were recovered from the flocculated cake at 83% yield with subsequent conversion through deoxygenation and hydroisomerization to a renewable diesel blendstock. This work is a first-of-its-kind demonstration of a novel integrated conversion process for algal biomass to produce fuel and chemical products of sufficient quality to be blend-ready feedstocks for further processing.

  13. Two-Phase Flow Modeling of Solid Dissolution in Liquid for Nutrient Mixing Improvement in Algal Raceway Ponds

    Directory of Open Access Journals (Sweden)

    Haider Ali

    2018-04-01

    Full Text Available Achieving optimal nutrient concentrations is essential to increasing the biomass productivity of algal raceway ponds. Nutrient mixing or distribution in raceway ponds is significantly affected by hydrodynamic and geometric properties. The nutrient mixing in algal raceway ponds under the influence of hydrodynamic and geometric properties of ponds is yet to be explored. Such a study is required to ensure optimal nutrient concentrations in algal raceway ponds. A novel computational fluid dynamics (CFD model based on the Euler–Euler numerical scheme was developed to investigate nutrient mixing in raceway ponds under the effects of hydrodynamic and geometric properties. Nutrient mixing was investigated by estimating the dissolution of nutrients in raceway pond water. Experimental and CFD results were compared and verified using solid–liquid mass transfer coefficient and nutrient concentrations. Solid–liquid mass transfer coefficient, solid holdup, and nutrient concentrations in algal pond were estimated with the effects of pond aspect ratios, water depths, paddle wheel speeds, and particle sizes of nutrients. From the results, it was found that the proposed CFD model effectively simulated nutrient mixing in raceway ponds. Nutrient mixing increased in narrow and shallow raceway ponds due to effective solid–liquid mass transfer. High paddle wheel speeds increased the dissolution rate of nutrients in raceway ponds.

  14. Laboratory evaluation of six algal species for larval nutritional suitability of the pestiferous midge Glyptotendipes paripes (Diptera: Chironomidae)

    Czech Academy of Sciences Publication Activity Database

    Frouz, Jan; Ali, A.; Lobinske, R. J.

    2004-01-01

    Roč. 97, č. 6 (2004), s. 1884-1890 ISSN 0022-0493 Institutional research plan: CEZ:AV0Z6066911 Keywords : Chironomidae * algal food * larval development Subject RIV: EH - Ecology, Behaviour Impact factor: 1.283, year: 2004

  15. Biophysical modelling of phytoplankton communities from first principles using two-layered spheres: Equivalent Algal Populations (EAP) model

    CSIR Research Space (South Africa)

    Robertson Lain, L

    2014-07-01

    Full Text Available (PFT) analysis. To these ends, an initial validation of a new model of Equivalent Algal Populations (EAP) is presented here. This paper makes a first order comparison of two prominent phytoplankton Inherent Optical Property (IOP) models with the EAP...

  16. 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

  17. Dose-response regressions for algal growth and similar continuous endpoints: Calculation of effective concentrations

    DEFF Research Database (Denmark)

    Christensen, Erik R.; Kusk, Kresten Ole; Nyholm, Niels

    2009-01-01

    We derive equations for the effective concentration giving 10% inhibition (EC10) with 95% confidence limits for probit (log-normal), Weibull, and logistic dose -responsemodels on the basis of experimentally derived median effective concentrations (EC50s) and the curve slope at the central point (50......% inhibition). For illustration, data from closed, freshwater algal assays are analyzed using the green alga Pseudokirchneriella subcapitata with growth rate as the response parameter. Dose-response regressions for four test chemicals (tetraethylammonium bromide, musculamine, benzonitrile, and 4...... regression program with variance weighting and proper inverse estimation. The Weibull model provides the best fit to the data for all four chemicals. Predicted EC10s (95% confidence limits) from our derived equations are quite accurate; for example, with 4-4-(trifluoromethyl)phenoxy-phenol and the probit...

  18. Cryptofauna of the epilithic algal matrix on an inshore coral reef, Great Barrier Reef

    Science.gov (United States)

    Kramer, M. J.; Bellwood, D. R.; Bellwood, O.

    2012-12-01

    Composed of a collection of algae, detritus, sediment and invertebrates, the epilithic algal matrix (EAM) is an abundant and ubiquitous feature of coral reefs. Despite its prevalence, there is a paucity of information regarding its associated invertebrate fauna. The cryptofaunal invertebrate community of the EAM was quantitatively investigated in Pioneer Bay on Orpheus Island, Great Barrier Reef. Using a vacuum collection method, a diversity of organisms representing 10 different phyla were identified. Crustacea dominated the samples, with harpacticoid copepods being particularly abundant (2025 ± 132 100 cm-2; mean density ± SE). The volume of coarse particulate matter in the EAM was strongly correlated with the abundance of harpacticoid copepods. The estimated biomass of harpacticoid copepods (0.48 ± 0.05 g m-2; wet weight) suggests that this group is likely to be important for reef trophodynamics and nutrient cycling.

  19. Synchronized sexuality of an algal symbiont and its dinoflagellate host, Peridinium balticum (Levander) Lemmermann.

    Science.gov (United States)

    Chesnick, J M; Cox, E R

    1987-01-01

    We report synchronized sexual reproduction between the chlorophyll c-containing algal endosymbiont and its dinoflagellate host in Peridinium balticum (Pyrrhophyta). This organism's importance lies in that it may represent an intermediate between primitive non-photosynthetic and advanced photosynthetic dinoflagellates. Fusion of the endosymbionts and their nuclei occurred concomitantly with syngamy of the host gametes. Significant morphological changes, including condensation of chromatin and crystalline rod formation, occurred in the symbiont nucleus during zygote development. These observations provide evidence that the endosymbiotic nucleus is not passive in sexual processes, as opposed to its reported passive state during mitosis. P. balticum may not only represent an intermediate in the evolution of chloroplast acquisition by dinoflagellates, but also, an intermediate in the evolution of the peridinian dinoflagellate sexual life history.

  20. 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.