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Sample records for alga botryococcus braunii

  1. A novel alphaproteobacterial ectosymbiont promotes the growth of the hydrocarbon-rich green alga Botryococcus braunii

    PubMed Central

    Tanabe, Yuuhiko; Okazaki, Yusuke; Yoshida, Masaki; Matsuura, Hiroshi; Kai, Atsushi; Shiratori, Takashi; Ishida, Ken-ichiro; Nakano, Shin-ichi; Watanabe, Makoto M.

    2015-01-01

    Botryococcus braunii is a colony-forming green alga that accumulates large amounts of liquid hydrocarbons within the colony. The utilization of B. braunii for biofuel production is however hindered by its low biomass productivity. Here we describe a novel bacterial ectosymbiont (BOTRYCO-2) that confers higher biomass productivity to B. braunii. 16S rDNA analysis indicated that the sequence of BOTRYCO-2 shows low similarity (<90%) to cultured bacterial species and located BOTRYCO-2 within a phylogenetic lineage consisting of uncultured alphaproteobacterial clones. Fluorescence in situ hybridization (FISH) studies and transmission electric microscopy indicated that BOTRYCO-2 is closely associated with B. braunii colonies. Interestingly, FISH analysis of a water bloom sample also found BOTRYCO-2 bacteria in close association with cyanobacterium Microcystis aeruginosa colonies, suggesting that BOTRYCO-2 relatives have high affinity to phytoplankton colonies. A PCR survey of algal bloom samples revealed that the BOTRYCO-2 lineage is commonly found in Microcystis associated blooms. Growth experiments indicated that B. braunii Ba10 can grow faster and has a higher biomass (1.8-fold) and hydrocarbon (1.5-fold) yield in the presence of BOTRYCO-2. Additionally, BOTRYCO-2 conferred a higher biomass yield to BOT-22, one of the fastest growing strains of B. braunii. We propose the species name ‘Candidatus Phycosocius bacilliformis’ for BOTRYCO-2. PMID:26130609

  2. Active Hydrocarbon Biosynthesis and Accumulation in a Green Alga, Botryococcus braunii (Race A)

    PubMed Central

    Hirose, Mana; Mukaida, Fukiko; Okada, Sigeru

    2013-01-01

    Among oleaginous microalgae, the colonial green alga Botryococcus braunii accumulates especially large quantities of hydrocarbons. This accumulation may be achieved more by storage of lipids in the extracellular space rather than in the cytoplasm, as is the case for all other examined oleaginous microalgae. The stage of hydrocarbon synthesis during the cell cycle was determined by autoradiography. The cell cycle of B. braunii race A was synchronized by aminouracil treatment, and cells were taken at various stages in the cell cycle and cultured in a medium containing [14C]acetate. Incorporation of 14C into hydrocarbons was detected. The highest labeling occurred just after septum formation, when it was about 2.6 times the rate during interphase. Fluorescent and electron microscopy revealed that new lipid accumulation on the cell surface occurred during at least two different growth stages and sites of cells. Lipid bodies in the cytoplasm were not prominent in interphase cells. These lipid bodies then increased in number, size, and inclusions, reaching maximum values just before the first lipid accumulation on the cell surface at the cell apex. Most of them disappeared from the cytoplasm concomitant with the second new accumulation at the basolateral region, where extracellular lipids continuously accumulated. The rough endoplasmic reticulum near the plasma membrane is prominent in B. braunii, and the endoplasmic reticulum was often in contact with both a chloroplast and lipid bodies in cells with increasing numbers of lipid bodies. We discuss the transport pathway of precursors of extracellular hydrocarbons in race A. PMID:23794509

  3. Study of a bloom of the oil-rich alga Botryococcus braunii in the Darwin River Reservoir

    SciTech Connect

    Wake, L.V.; Hillen, L.W.

    1980-01-01

    A bloom of the freshwater alga Botryococcus braunii Kutzing appeared in the Darwin River Reservoir in 1976. At the time of algal sampling, the bloom was estimated at 1500 ton and possibly double this mass at a maximum cell concentration. The alga is characterized by a high liquid hydrocarbon content, sufficient to cause flotation of the algal colonies. This report is an examination of the waters of the reservoir and of the characteristics of the alga. Observations are included on the formation of a material known as Coorongite, a rubbery complex produced by the drying of colony aggregates at the shoreline. Earlier reports of blooms of B. braunii are reviewed in relation to this study. 42 references.

  4. Nitrogen deprivation-induced de novo transcriptomic profiling of the oleaginous green alga Botryococcus braunii 779

    PubMed Central

    Xu, Zhenyu; He, Jing; Qi, Shuyuan; Liu, Jianhua

    2015-01-01

    To assess the effect of nitrogen deprivation (ND), a moderately growing A-race Botryococcus braunii subisolate 779 was subjected to nitrogen deprivation for 3days. De novo transcriptome was assembled and annotated by using Trinity software and Basic Local Alignment Search Tools (BLAST), respectively. Comparative analysis indicates that transcriptomes of A-races differ from those of B-races. Furthermore, majority of the homologous ESTs in A-race but not B-race transcriptomes were unknown sequences. Upon ND, level of photosynthetic transcripts, but not photosynthetic efficiency was downregulated. Unlike hydrocarbon contents, ESTs involved in hydrocarbon biosynthesis were not upregulated. Taken together, our results imply that A- and B-races belong to different B. braunii subspecies. Upon ND, excess photosynthetic transcripts are recycled for nitrogen; and hydrocarbon accumulation is not via de novo biosynthesis. Here we describe in details the data contents and analytic methodologies associated with the data uploaded to Gene Expression Omnibus (accession number GSE71296).

  5. Transformation of Lipid Bodies Related to Hydrocarbon Accumulation in a Green Alga, Botryococcus braunii (Race B)

    PubMed Central

    Uno, Yuki; Nishii, Ichiro; Kagiwada, Satoshi; Okada, Sigeru; Noguchi, Tetsuko

    2013-01-01

    The colonial microalga Botryococcus braunii accumulates large quantities of hydrocarbons mainly in the extracellular space; most other oleaginous microalgae store lipids in the cytoplasm. Botryococcus braunii is classified into three principal races (A, B, and L) based on the types of hydrocarbons. Race B has attracted the most attention as an alternative to petroleum by its higher hydrocarbon contents than the other races and its hydrocarbon components, botryococcenes and methylsqualenes, both can be readily converted into biofuels. We studied race B using fluorescence and electron microscopy, and clarify the stage when extracellular hydrocarbon accumulation occurs during the cell cycle, in a correlation with the behavior and structural changes of the lipid bodies and discussed development of the algal colony. New accumulation of lipids on the cell surface occurred after cell division in the basolateral region of daughter cells. While lipid bodies were observed throughout the cell cycle, their size and inclusions were dynamically changing. When cells began dividing, the lipid bodies increased in size and inclusions until the extracellular accumulation of lipids started. Most of the lipids disappeared from the cytoplasm concomitant with the extracellular accumulation, and then reformed. We therefore hypothesize that lipid bodies produced during the growth of B. braunii are related to lipid secretion. New lipids secreted at the cell surface formed layers of oil droplets, to a maximum depth of six layers, and fused to form flattened, continuous sheets. The sheets that combined a pair of daughter cells remained during successive cellular divisions and the colony increased in size with increasing number of cells. PMID:24339948

  6. Micronutrient Requirements for Growth and Hydrocarbon Production in the Oil Producing Green Alga Botryococcus braunii (Chlorophyta)

    PubMed Central

    Song, Liang; Qin, Jian G.; Su, Shengqi; Xu, Jianhe; Clarke, Stephen; Shan, Yichu

    2012-01-01

    The requirements of micronutrients for biomass and hydrocarbon production in Botryococcus braunii UTEX 572 were studied using response surface methodology. The concentrations of four micronutrients (iron, manganese, molybdenum, and nickel) were manipulated to achieve the best performance of B. braunii in laboratory conditions. The responses of algal biomass and hydrocarbon to the concentration variations of the four micronutrients were estimated by a second order quadratic regression model. Genetic algorithm calculations showed that the optimal level of micronutrients for algal biomass were 0.266 M iron, 0.707 M manganese, 0.624 M molybdenum and 3.38 M nickel. The maximum hydrocarbon content could be achieved when the culture media contained 10.43 M iron, 6.53 M manganese, 0.012 M molybdenum and 1.73 M nickel. The validation through an independent test in a photobioreactor suggests that the modified media with optimised concentrations of trace elements can increase algal biomass by 34.5% and hydrocarbon by 27.4%. This study indicates that micronutrients play significant roles in regulating algal growth and hydrocarbon production, and the response surface methodology can be used to optimise the composition of culture medium in algal culture. PMID:22848502

  7. Hydrocracking of the oils of Botryococcus braunii to transport fuels.

    PubMed

    Hillen, L W; Pollard, G; Wake, L V; White, N

    1982-01-01

    Hydrocarbon oils of the alga Botryococcus braunii, extracted from a natural "bloom" of the plant, have been hydrocracked to produce a distillate comprising 67% gasoline fraction, 15% aviation turbine fuel fraction, 15% diesel fuel fraction, and 3% residual oil. The distillate was examined by a number of standard petroleum industry test methods. This preliminary investigation indicates that the oils of B. braunii are suitable as a feedstock material for hydrocracking to transport fuels. PMID:18546110

  8. Colony Organization in the Green Alga Botryococcus braunii (Race B) Is Specified by a Complex Extracellular Matrix

    PubMed Central

    Weiss, Taylor L.; Roth, Robyn; Goodson, Carrie; Vitha, Stanislav; Black, Ian; Azadi, Parastoo; Rusch, Jannette; Holzenburg, Andreas

    2012-01-01

    Botryococcus braunii is a colonial green alga whose cells associate via a complex extracellular matrix (ECM) and produce prodigious amounts of liquid hydrocarbons that can be readily converted into conventional combustion engine fuels. We used quick-freeze deep-etch electron microscopy and biochemical/histochemical analysis to elucidate many new features of B. braunii cell/colony organization and composition. Intracellular lipid bodies associate with the chloroplast and endoplasmic reticulum (ER) but show no evidence of being secreted. The ER displays striking fenestrations and forms a continuous subcortical system in direct contact with the cell membrane. The ECM has three distinct components. (i) Each cell is surrounded by a fibrous β-1, 4- and/or β-1, 3-glucan-containing cell wall. (ii) The intracolonial ECM space is filled with a cross-linked hydrocarbon network permeated with liquid hydrocarbons. (iii) Colonies are enclosed in a retaining wall festooned with a fibrillar sheath dominated by arabinose-galactose polysaccharides, which sequesters ECM liquid hydrocarbons. Each cell apex associates with the retaining wall and contributes to its synthesis. Retaining-wall domains also form “drapes” between cells, with some folding in on themselves and penetrating the hydrocarbon interior of a mother colony, partitioning it into daughter colonies. We propose that retaining-wall components are synthesized in the apical Golgi apparatus, delivered to apical ER fenestrations, and assembled on the surfaces of apical cell walls, where a proteinaceous granular layer apparently participates in fibril morphogenesis. We further propose that hydrocarbons are produced by the nonapical ER, directly delivered to the contiguous cell membrane, and pass across the nonapical cell wall into the hydrocarbon-based ECM. PMID:22941913

  9. Colony organization in the green alga Botryococcus braunii (Race B) is specified by a complex extracellular matrix.

    PubMed

    Weiss, Taylor L; Roth, Robyn; Goodson, Carrie; Vitha, Stanislav; Black, Ian; Azadi, Parastoo; Rusch, Jannette; Holzenburg, Andreas; Devarenne, Timothy P; Goodenough, Ursula

    2012-12-01

    Botryococcus braunii is a colonial green alga whose cells associate via a complex extracellular matrix (ECM) and produce prodigious amounts of liquid hydrocarbons that can be readily converted into conventional combustion engine fuels. We used quick-freeze deep-etch electron microscopy and biochemical/histochemical analysis to elucidate many new features of B. braunii cell/colony organization and composition. Intracellular lipid bodies associate with the chloroplast and endoplasmic reticulum (ER) but show no evidence of being secreted. The ER displays striking fenestrations and forms a continuous subcortical system in direct contact with the cell membrane. The ECM has three distinct components. (i) Each cell is surrounded by a fibrous ?-1, 4- and/or ?-1, 3-glucan-containing cell wall. (ii) The intracolonial ECM space is filled with a cross-linked hydrocarbon network permeated with liquid hydrocarbons. (iii) Colonies are enclosed in a retaining wall festooned with a fibrillar sheath dominated by arabinose-galactose polysaccharides, which sequesters ECM liquid hydrocarbons. Each cell apex associates with the retaining wall and contributes to its synthesis. Retaining-wall domains also form "drapes" between cells, with some folding in on themselves and penetrating the hydrocarbon interior of a mother colony, partitioning it into daughter colonies. We propose that retaining-wall components are synthesized in the apical Golgi apparatus, delivered to apical ER fenestrations, and assembled on the surfaces of apical cell walls, where a proteinaceous granular layer apparently participates in fibril morphogenesis. We further propose that hydrocarbons are produced by the nonapical ER, directly delivered to the contiguous cell membrane, and pass across the nonapical cell wall into the hydrocarbon-based ECM. PMID:22941913

  10. A comparative study of macromolecular substances of a Coorongite and cell walls of the extant alga Botryococcus braunii

    SciTech Connect

    Gatellier, J.P.L.A.; De Leeuw, J.W.; Sinninghe Damste, J.S. ); Derenne, S.; Largeau, C.; Metzger, P. )

    1993-05-01

    A Coorongite sample of Lake Balkash (Kazakhstan, CIS) was analyzed in detail by [sup 13]C-NMR, FTIR, Curie point pyrolysis-gas chromatography-mass spectrometry, and by fractionation and derivatization with dimethyldisulphide of an off-line pyrolysate. Both the spectroscopic and the pyrolysis data indicate that the Coorongite was derived almost entirely of organic matter of the green microalga Botryococcus braunii race A. Homologous series of n-alkanes and n-alk-1-enes in all pyrolysates indicated the presence of algaenan, a highly aliphatic and resistant cell wall biomacromolecule of B. braunii race A. Highly specific pyrolysis products, in particular n-alkadienes, n-alkatrienes, alk-1-en-[omega][sup 9]-ones, and alk-1-en-[omega][sup 10]-ones with C[sub 27], C[sub 29], and C[sub 31] carbon atoms clearly indicated that C[sub 27], C[sub 29], and C[sub 31] alkadienes and alkatrienes, originally present in B. braunii race A as such, were cross-linked by oxygen during the very early stages of diagenesis under oxic conditions. Furthermore, several types of dialkenylethers, also present as soluble lipids in B. braunii race A, had undergone cross-linking by oxygen as well. These cross-linked lipids contribute significantly to the Coorongite and clearly demonstrate that under specific conditions kerogen consists of both preserved biomacromolecules and insoluble, cross-linked, low-molecular-weight lipids. 43 refs., 14 figs., 1 tab.

  11. Seawater-Cultured Botryococcus braunii for Efficient Hydrocarbon Extraction

    PubMed Central

    Furuhashi, Kenichi; Saga, Kiyotaka; Okada, Shigeru; Imou, Kenji

    2013-01-01

    As a potential source of biofuel, the green colonial microalga Botryococcus braunii produces large amounts of hydrocarbons that are accumulated in the extracellular matrix. Generally, pretreatment such as drying or heating of wet algae is needed for sufficient recoveries of hydrocarbons from B. braunii using organic solvents. In this study, the Showa strain of B. braunii was cultured in media derived from the modified Chu13 medium by supplying artificial seawater, natural seawater, or NaCl. After a certain period of culture in the media with an osmotic pressure corresponding to 1/4-seawater, hydrocarbon recovery rates exceeding 90% were obtained by simply mixing intact wet algae with n-hexane without any pretreatments and the results using the present culture conditions indicate the potential for hydrocarbon milking. Highlights Seawater was used for efficient hydrocarbon extraction from Botryococcus braunii. The alga was cultured in media prepared with seawater or NaCl. Hydrocarbon recovery rate exceeding 90% was obtained without any pretreatment. PMID:23799107

  12. Bio-crude transcriptomics: Gene discovery and metabolic network reconstruction for the biosynthesis of the terpenome of the hydrocarbon oil-producing green alga, Botryococcus braunii race B (Showa)*

    SciTech Connect

    Molnár, István; Lopez, David; Wisecaver, Jennifer H.; Devarenne, Timothy P.; Weiss, Taylor L.; Pellegrini, Matteo; Hackett, Jeremiah D.

    2012-10-30

    Microalgae hold promise for yielding a biofuel feedstock that is sustainable, carbon-neutral, distributed, and only minimally disruptive for the production of food and feed by traditional agriculture. Amongst oleaginous eukaryotic algae, the B race of Botryococcus braunii is unique in that it produces large amounts of liquid hydrocarbons of terpenoid origin. These are comparable to fossil crude oil, and are sequestered outside the cells in a communal extracellular polymeric matrix material. The biosynthetic engineering of terpenoid bio-crude production requires identification of genes and reconstruction of metabolic pathways responsible for production of both hydrocarbons and other metabolites of the alga that compete for photosynthetic carbon and energy.

  13. Bio-crude transcriptomics: Gene discovery and metabolic network reconstruction for the biosynthesis of the terpenome of the hydrocarbon oil-producing green alga, Botryococcus braunii race B (Showa)*

    DOE PAGESBeta

    Molnár, István; Lopez, David; Wisecaver, Jennifer H.; Devarenne, Timothy P.; Weiss, Taylor L.; Pellegrini, Matteo; Hackett, Jeremiah D.

    2012-10-30

    Microalgae hold promise for yielding a biofuel feedstock that is sustainable, carbon-neutral, distributed, and only minimally disruptive for the production of food and feed by traditional agriculture. Amongst oleaginous eukaryotic algae, the B race of Botryococcus braunii is unique in that it produces large amounts of liquid hydrocarbons of terpenoid origin. These are comparable to fossil crude oil, and are sequestered outside the cells in a communal extracellular polymeric matrix material. The biosynthetic engineering of terpenoid bio-crude production requires identification of genes and reconstruction of metabolic pathways responsible for production of both hydrocarbons and other metabolites of the alga thatmore » compete for photosynthetic carbon and energy.« less

  14. Functional Identification of Triterpene Methyltransferases from Botryococcus braunii Race B*

    PubMed Central

    Niehaus, Tom D.; Kinison, Scott; Okada, Shigeru; Yeo, Yun-soo; Bell, Stephen A.; Cui, Ping; Devarenne, Timothy P.; Chappell, Joe

    2012-01-01

    Botryococcus braunii race B is a colony-forming, green algae that accumulates triterpene oils in excess of 30% of its dry weight. The composition of the triterpene oils is dominated by dimethylated to tetramethylated forms of botryococcene and squalene. Although unusual mechanisms for the biosynthesis of botryococcene and squalene were recently described, the enzyme(s) responsible for decorating these triterpene scaffolds with methyl substituents were unknown. A transcriptome of B. braunii was screened computationally assuming that the triterpene methyltransferases (TMTs) might resemble the S-adenosyl methionine-dependent enzymes described for methylating the side chain of sterols. Six sterol methyltransferase-like genes were isolated and functionally characterized. Three of these genes when co-expressed in yeast with complementary squalene synthase or botryococcene synthase expression cassettes resulted in the accumulation of mono- and dimethylated forms of both triterpene scaffolds. Surprisingly, TMT-1 and TMT-2 exhibited preference for squalene as the methyl acceptor substrate, whereas TMT-3 showed a striking preference for botryococcene as its methyl acceptor substrate. These in vivo preferences were confirmed with in vitro assays utilizing microsomal preparations from yeast overexpressing the respective genes, which encode for membrane-associated enzymes. Structural examination of the in vivo yeast generated mono- and dimethylated products by NMR identified terminal carbons, C-3 and C-22/C-20, as the atomic acceptor sites for the methyl additions to squalene and botryococcene, respectively. These sites are identical to those previously reported for the triterpenes extracted from the algae. The availability of closely related triterpene methyltransferases exhibiting distinct substrate selectivity and successive catalytic activities provides important tools for investigating the molecular mechanisms responsible for the specificities exhibited by these unique enzymes. PMID:22241476

  15. Aerated swine lagoon wastewater: a promising alternative medium for Botryococcus braunii cultivation in open system.

    PubMed

    Liu, Junzhi; Ge, Yaming; Cheng, Haixiang; Wu, Lianghuan; Tian, Guangming

    2013-07-01

    To understand the potential of using swine lagoon wastewater to cultivate Botryococcus braunii for biofuel production, growth characteristics of B. braunii 765 cultivated in aerated swine lagoon wastewater (ASLW) without sterilization and pH adjustment were investigated. The results showed that the alga strain could maintain competitive advantage over the 26-day cultivation. The highest dry biomass of alga grown in ASLW was 0.94 mg L(-1) at day 24, which was 1.73 times that grown in BG11 medium, an artificial medium normally used for B. braunii cultivation. And the algal hydrocarbon content was 23.8%, being more than twice that in BG11 medium. Additionally, after the 26-day cultivation, about 40.8% of TN and 93.3% of TP in ASLW were removed, indicating also good environmental benefits of algal bioremediation. PMID:23660382

  16. Bio-crude transcriptomics: Gene discovery and metabolic network reconstruction for the biosynthesis of the terpenome of the hydrocarbon oil-producing green alga, Botryococcus braunii race B (Showa)*

    PubMed Central

    2012-01-01

    Background Microalgae hold promise for yielding a biofuel feedstock that is sustainable, carbon-neutral, distributed, and only minimally disruptive for the production of food and feed by traditional agriculture. Amongst oleaginous eukaryotic algae, the B race of Botryococcus braunii is unique in that it produces large amounts of liquid hydrocarbons of terpenoid origin. These are comparable to fossil crude oil, and are sequestered outside the cells in a communal extracellular polymeric matrix material. Biosynthetic engineering of terpenoid bio-crude production requires identification of genes and reconstruction of metabolic pathways responsible for production of both hydrocarbons and other metabolites of the alga that compete for photosynthetic carbon and energy. Results A de novo assembly of 1,334,609 next-generation pyrosequencing reads form the Showa strain of the B race of B. braunii yielded a transcriptomic database of 46,422 contigs with an average length of 756 bp. Contigs were annotated with pathway, ontology, and protein domain identifiers. Manual curation allowed the reconstruction of pathways that produce terpenoid liquid hydrocarbons from primary metabolites, and pathways that divert photosynthetic carbon into tetraterpenoid carotenoids, diterpenoids, and the prenyl chains of meroterpenoid quinones and chlorophyll. Inventories of machine-assembled contigs are also presented for reconstructed pathways for the biosynthesis of competing storage compounds including triacylglycerol and starch. Regeneration of S-adenosylmethionine, and the extracellular localization of the hydrocarbon oils by active transport and possibly autophagy are also investigated. Conclusions The construction of an annotated transcriptomic database, publicly available in a web-based data depository and annotation tool, provides a foundation for metabolic pathway and network reconstruction, and facilitates further omics studies in the absence of a genome sequence for the Showa strain of B. braunii, race B. Further, the transcriptome database empowers future biosynthetic engineering approaches for strain improvement and the transfer of desirable traits to heterologous hosts. PMID:23110428

  17. Draft Genome Sequences of Achromobacter piechaudii GCS2, Agrobacterium sp. Strain SUL3, Microbacterium sp. Strain GCS4, Shinella sp. Strain GWS1, and Shinella sp. Strain SUS2 Isolated from Consortium with the Hydrocarbon-Producing Alga Botryococcus braunii.

    PubMed

    Jones, Katy J; Moore, Karen; Sambles, Christine; Love, John; Studholme, David J; Aves, Stephen J

    2016-01-01

    A variety of bacteria associate with the hydrocarbon-producing microalga Botryococcus braunii, some of which may influence its growth. We report here the genome sequences for Achromobacter piechaudii GCS2, Agrobacterium sp. strain SUL3, Microbacterium sp. strain GCS4, and Shinella sp. strains GWS1 and SUS2, isolated from a laboratory culture of B.braunii, race B, strain Guadeloupe. PMID:26769927

  18. Draft Genome Sequences of Achromobacter piechaudii GCS2, Agrobacterium sp. Strain SUL3, Microbacterium sp. Strain GCS4, Shinella sp. Strain GWS1, and Shinella sp. Strain SUS2 Isolated from Consortium with the Hydrocarbon-Producing Alga Botryococcus braunii

    PubMed Central

    Jones, Katy J.; Moore, Karen; Love, John

    2016-01-01

    A variety of bacteria associate with the hydrocarbon-producing microalga Botryococcus braunii, some of which may influence its growth. We report here the genome sequences for Achromobacter piechaudii GCS2, Agrobacterium sp. strain SUL3, Microbacterium sp. strain GCS4, and Shinella sp. strains GWS1 and SUS2, isolated from a laboratory culture of B. braunii, race B, strain Guadeloupe. PMID:26769927

  19. Effect of thermal pretreatments on hydrocarbon recovery from Botryococcus braunii.

    PubMed

    Magota, A; Saga, K; Okada, S; Atobe, S; Imou, K

    2012-11-01

    Thermal pretreatment were tested to increase the recovery of hydrocarbons from Botryococcus braunii/water mixtures via extraction with hexane. The effectiveness of treatment temperature was dependent on the B. braunii strain and the lowest temperatures which recovered over 90% of hydrocarbons were 60, 85 and 75C for the Yamanaka, Showa and Kawaguchi-1 strains respectively. The holding times of thermal pretreatment had less of an influence on hydrocarbon recovery than treatment temperature and, depending on the strain, recoveries of between 74.9% and 94.9% were achieved after thermal pretreatments at 80-90C for only 2.5min. These results suggest thermal pretreatment could reduce the energy consumption of oil recovery process from wet B. braunii cells. PMID:22940319

  20. Interactions of Botryococcus braunii cultures with bacterial biofilms.

    PubMed

    Rivas, Mariella O; Vargas, Pedro; Riquelme, Carlos E

    2010-10-01

    Unicellular microalgae generally grow in the presence of bacteria, particularly when they are farmed massively. This study analyzes the bacteria associated with mass culture of Botryococcus braunii: both the planktonic bacteria in the water column and those forming biofilms adhered to the surface of the microalgal cells (?10?-10? culturable cells per gram microalgae). Furthermore, we identified the culturable bacteria forming a biofilm in the microalgal cells by 16S rDNA sequencing. At least eight different culturable species of bacteria were detected in the biofilm and were evaluated for the presence of quorum-sensing signals in these bacteria. Few studies have considered the implications of this phenomenon as regards the interaction between bacteria and microalgae. Production of C4-AHL and C6-AHL were detected in two species, Pseudomonas sp. and Rhizobium sp., which are present in the bacterial biofilm associated with B. braunii. This type of signal was not detected in the planktonic bacteria isolated from the water. We also noted that the bacterium, Rhizobium sp., acted as a probiotic bacterium and significantly encouraged the growth of B. braunii. A direct application of these beneficial bacteria associated with B. braunii could be, to use them like inoculants for large-scale microalgal cultures. They could optimize biomass production by enhancing growth, particularly in this microalga that has a low growth rate. PMID:20502890

  1. Identification of unique mechanisms for triterpene biosynthesis in Botryococcus braunii

    PubMed Central

    Niehaus, Tom D.; Okada, Shigeru; Devarenne, Timothy P.; Watt, David S.; Sviripa, Vitaliy; Chappell, Joe

    2011-01-01

    Botryococcene biosynthesis is thought to resemble that of squalene, a metabolite essential for sterol metabolism in all eukaryotes. Squalene arises from an initial condensation of two molecules of farnesyl diphosphate (FPP) to form presqualene diphosphate (PSPP), which then undergoes a reductive rearrangement to form squalene. In principle, botryococcene could arise from an alternative rearrangement of the presqualene intermediate. Because of these proposed similarities, we predicted that a botryococcene synthase would resemble squalene synthase and hence isolated squalene synthase-like genes from Botryococcus braunii race B. While B. braunii does harbor at least one typical squalene synthase, none of the other three squalene synthase-like (SSL) genes encodes for botryococcene biosynthesis directly. SSL-1 catalyzes the biosynthesis of PSPP and SSL-2 the biosynthesis of bisfarnesyl ether, while SSL-3 does not appear able to directly utilize FPP as a substrate. However, when combinations of the synthase-like enzymes were mixed together, in vivo and in vitro, robust botryococcene (SSL-1+SSL-3) or squalene biosynthesis (SSL1+SSL-2) was observed. These findings were unexpected because squalene synthase, an ancient and likely progenitor to the other Botryococcus triterpene synthases, catalyzes a two-step reaction within a single enzyme unit without intermediate release, yet in B. braunii, these activities appear to have separated and evolved interdependently for specialized triterpene oil production greater than 500MYA. Coexpression of the SSL-1 and SSL-3 genes in different configurations, as independent genes, as gene fusions, or targeted to intracellular membranes, also demonstrate the potential for engineering even greater efficiencies of botryococcene biosynthesis. PMID:21746901

  2. Bio-harvesting and pyrolysis of the microalgae Botryococcus braunii.

    PubMed

    Al-Hothaly, Khalid A; Adetutu, Eric M; Taha, Mohamed; Fabbri, Daniele; Lorenzetti, Chiara; Conti, Roberto; May, Brian H; Shar, Sahar S; Bayoumi, Reda A; Ball, Andrew S

    2015-09-01

    The microalgae Botryococcus braunii is widely recognized as a potentially important biofuel-feedstock whose commercial exploitation is limited by difficulties with its cultivation and harvesting. In this study, two B. braunii strains, Kossou-4 and Overjuyo-3 were successfully cultured at a 500 l-scale for 60-days. Harvesting by bio-flocculation with Aspergillus fumigatus at an optimum ratio of 1:40 of fungus to microalgal culture resulted in up to 98% recovery of biomass in the two strains. Ultimate analysis (C, N, H, S, ash, high heating value) and pyrolysis (analytical and preparative pyrolysis and GC-MS assays) showed that co-harvesting with fungi did not cause any impairment of the feedstock value of the microalgal biomass. This work represents the first report on the successful culturing and harvesting of these strains at a 500 l-scale using bio-flocculation. The use of A. fumigatus represents an efficient and economical method for the harvest of B. braunii for biofuel production. PMID:25983230

  3. Towards the commercialization of Botryococcus braunii for triterpenoid production.

    PubMed

    Al-Hothaly, Khalid A; Adetutu, Eric M; May, Brian H; Taha, Mohamed; Ball, Andrew S

    2015-10-01

    Botryococcus braunii can accumulate unusually high levels of triterpenoid hydrocarbons making it a potential source of high value chemicals. However, its commercial application is hampered by its slow growth and lack of large-scale studies of triterpenoid hydrocarbon production. This study investigated hydrocarbon production in two race B of B. braunii strains, Overjuyo-3 and Kossou-4, at 25 °C in 500 L open tanks under artificial lighting in modified BG11 medium over 60 days. Maximum growth was reached by 40 days with Overjuyo-3 producing more biomass (3.05 g L(-1)) than Kossou-4 (2.55 g L(-1)). However, Kossou-4 produced more oil (0.75 g L(-1)) and triterpenoid hydrocarbons (C30-C34; 50 % of oil weight) compared to 0.63 g L(-1) of oil in Overjuyo-3 with triterpenoid hydrocarbons making up 29 % of oil weight. This research demonstrates for the first time that large-scale production of high value triterpenoid hydrocarbon for commercial application is feasible with Kossou-4 strain. PMID:26264928

  4. Isolation and Characterization of Two Squalene Epoxidase Genes from Botryococcus braunii, Race B

    PubMed Central

    Uchida, Hidenobu; Sumimoto, Koremitsu; Ferriols, Victor Marco Emmanuel; Imou, Kenji; Saga, Kiyotaka; Furuhashi, Kenichi; Matsunaga, Shigeki; Okada, Shigeru

    2015-01-01

    The B race of the green microalga Botryococcus braunii produces triterpene hydrocarbons, botryococcenes and methylsqualenes that can be processed into jet fuels with high heating values. In this alga, squalene is also converted into membrane sterols after 2,3-epoxidation. In the present study, cDNA clones of two distinct squalene epoxidases (BbSQE-I and -II) were isolated. Predicted amino acid sequences encoded on these genes are 45% identical with each other. Introduction of BbSQE-I or -II into Saccharomyces cerevisie erg1 mutants resulted in the complementation of ergosterol auxotrophy. The relative expression level of SQE-II increased 3.5-fold from the early stage to the middle phase of a culture period of 42 days, while that of SQE-I was almost constant throughout the culture period. Southern blot analyses suggested that these genes are single-copied genes. This is the first report on the isolation of functional SQEs that are encoded in duplicated loci in the algal genome. PMID:25830359

  5. Botryococcus braunii cells: ultrasound-intensified outdoor cultivation integrated with in situ magnetic separation.

    PubMed

    Wang, Shi-Kai; Wang, Feng; Stiles, Amanda R; Guo, Chen; Liu, Chun-Zhao

    2014-09-01

    An integrated system combining ultrasound-intensified outdoor cultivation of Botryococcus braunii with in situ magnetic harvesting of the algal cells was developed. The algal cells were cultivated in 200 L plastic bag reactors, and seven five-minute ultrasonic treatments at a four-day interval using a fixed frequency of 40 kHz and a total power of 300 W improved algal cell biomass and hydrocarbon productivity. The algal cells were harvested using functional magnetic particles and a magnetic separator, and a recovery efficiency of 90% was obtained under continuous operation at a flow rate of 100mL/min using the in situ magnetic separation system. The overall production cost using the integrated system was US$ 25.14 per kilogram of B. braunii dry biomass. The system developed in this study provides a base for the industrial production of B. braunii. PMID:24998478

  6. Studies on batch and continuous cultures of Botryococcus braunii: hydrocarbon production in relation to physiological state, cell ultrastructure, and phosphate nutrition

    SciTech Connect

    Casadevall, E.; Dif, D.; Largeau, C.; Gudin, C.; Chaumont, D.; Desanti, O.

    1985-01-01

    The growth of the hydrocarbon-rich alga Botryococcus braunii was studied under air-lift conditions using batch and continuous cultures. Large variations in the physiological state of B. braunii were achieved in batch cultures and in continuous cultures with various dilution rates. The possible effects of these variations upon hydrocarbons (nature, relative abundance, location, level, productivity) and also on the production of exocellular polysaccharides were examined. The relationships between the physiological state of B. braunii and its hydrocarbon and polysaccharide production were discussed and compared with those generally observed in unicellular algae. The factors giving rise to the transition from high to low productivity stages were considered. To this end the authors examined, at first, the variations in cell ultrastructure and the resulting degeneration occurring during batch cultures. Afterward the parallel changes in some parameters of the medium (pH, phosphate level) were determined and their possible relationships with B. braunii growth and hydrocarbon production were discussed. The main features of phosphate nutrition in B. braunii and its effects on hydrocarbons were finally examined.

  7. Catalytic gasification of oil-extracted residue biomass of Botryococcus braunii.

    PubMed

    Watanabe, Hideo; Li, Dalin; Nakagawa, Yoshinao; Tomishige, Keiichi; Watanabe, Makoto M

    2015-09-01

    Catalytic gasification of the oil-extracted residue biomass of Botryococcus braunii was demonstrated in a laboratory-scale continuous feeding dual bed reactor. Steam gasification at 1023 K over Ni-Fe/Mg/Al catalyst can completely reform tar derived from pyrolysis of the residue biomass into C1 gases and hydrogen, and has achieved 91%-C conversion to gaseous product (CO+CO2+CH4). Composition of product gas has higher contents of CO and H2 with their ratio (H2/CO) of around 2.4 which is slightly H2-rich syngas. Maximum hydrogen yield of 74.7 mmol g-biomass(-1) obtained in this work is much higher than that from gasification of other algal biomass reported in literature. The residue biomass of B. braunii can be a superior renewable source of syngas or hydrogen. PMID:25817421

  8. Structure and chemistry of a new chemical race of Botryococcus braunii (chlorophyceae) that produces lycopadiene, a tetraterpenoid hydrocarbon

    SciTech Connect

    Metzger, P.; Allard, B.; Casadevall, E. ); Berkaloff, C.; Coute, A. )

    1990-06-01

    New strains of the hydrocarbon rich alga Botryococcus braunii Kuetzing were isolated from water samples collected in three tropical freshwater lakes. These strains synthesize lycopadiene, a tetraterpenoid metabolite, as their sole hydrocarbon. The morphological and ultrastructural characteristics of these algae are similar to those reported for previously described strains which produce either alkadienes or botryococcenes. The pyriform shaped cells are embedded in a colonial matrix formed by layers of closely appressed external walls; this dense matrix is impregnated by the hydrocarbon and some other lipids. We believe the new strains synthesizing lycopadiene form a third chemical race in B. braunii, besides the alkadiene and botryococcene races, rather than a different species. Like the other two types of hydrocarbons, lycopadiene was produced primarily during the exponential and linear growth phases. The major fatty acid in the three races was oleic acid. This fatty acid was predominant in the alkadiene race; palmitic and octacosenoic acid also were present in appreciable amounts in the three races. Cholest-5-en-3{beta}-ol, 24-methylcholest-5-en-3{beta}-ol and 24-ethylcholest-5-en-3{beta}-ol occurred in the three races; three unidentified sterols also were detected in the lycopadiene race. Moreover, the presence of very long chain alkenyl-phenols in the lipids of algae of the alkadiene race was not observed in the botryococcene and lycopadiene races. Of the polysaccharides released in the medium, galactose appeared as a primary component: it predominated in the botryococcene race. The other major constituents were fucose for the alkadiene race and glucose and fucose for the lycopadiene race.

  9. Biodiesel synthesis by direct transesterification of microalga Botryococcus braunii with continuous methanol reflux.

    PubMed

    Hidalgo, Pamela; Ciudad, Gustavo; Schober, Sigurd; Mittelbach, Martin; Navia, Rodrigo

    2015-04-01

    Direct transesterification of Botryococcus braunii with continuous acyl acceptor reflux was evaluated. This method combines in one step lipid extraction and esterification/transesterification. Fatty acid methyl esters (FAME) synthesis by direct conversion of microalgal biomass was carried out using sulfuric acid as catalyst and methanol as acyl acceptor. In this system, once lipids are extracted, they are contacted with the catalyst and methanol reaching 82%wt of FAME yield. To optimize the reaction conditions, a factorial design using surface response methodology was applied. The effects of catalyst concentration and co-solvent concentration were studied. Hexane was used as co-solvent for increasing lipid extraction performance. The incorporation of hexane in the reaction provoked an increase in FAME yield from 82% (pure methanol) to 95% when a 47%v/v of hexane was incorporated in the reaction. However, the selectivity towards non-saponifiable lipids such as sterols was increased, negatively affecting biodiesel quality. PMID:25625464

  10. Closed pyrolyses of the isoprenoid algaenan of Botryococcus braunii, L race: Geochemical implications for derived kerogens

    SciTech Connect

    Behar, F.; Derenne, S.; Largeau, C.

    1995-07-01

    Algaenans, i.e, highly aliphatic, nonhydrolysable, insoluble macromolecular constituents, have been identified in a number of microalga cell walls and their selective preservation shown to play a major role in the formation of numerous kerogens. All the algaenans so far examined comprise a network of long polymethylenic chains, except for the L race of Botryococcus braunii. The resistant macromolecular material isolated from the latter, termed PRB L, is based on C{sub 40} isoprenoid chains with a lycopane-type skeleton. Recent comparative studies of PRB L and of Botryococcus-derived sediments provided the first example of kerogen formation via the selective preservation of an {open_quotes}isoprenoid{close_quotes} algaenan. The present study is concerned with PRB L pyrolyses in sealed gold tubes under various temperature/time conditions (260-350{degrees}C, 0.5-69 h). For the conversion rates thus obtained, ranging from 30 to 100%, a complete mass balance of the different families of pyrolysis products was established; most of the C{sub 1} to C{sub 40} pyrolysate constituents were identified and the abundances of the above compounds and their variations with conversion progress were determined. This study thus allowed us (1) to derive further information about PRB L chemical structure (location of the ether bridges, contribution to linear chains and their relationships with the C{sub 40} isoprenoid ones), (2) to determine the behaviour of this isoprenoid algaenan to thermal stress (timing of the formation of the secondary products, and further degradations), and (3) to show, in connection with previous studies, that PRB L-derived kerogens should exhibit pronounced differences relative to standard type I kerogens, the latter being based on polymethylenic chains, regarding not only the structure of the generated products but also the timing of oil generation (upward shift of the catagenesis zone).

  11. Closed pyrolyses of the isoprenoid algaenan of Botryococcus braunii, L race: geochemical implications for derived kerogens

    NASA Astrophysics Data System (ADS)

    Behar, F.; Derenne, S.; Largeau, C.

    1995-07-01

    Algaenans, i.e., highly aliphatic, nonhydrolysable, insoluble macromolecular constituents, have been identified in a number of microalga cell walls and their selective preservation shown to play a major role in the formation of numerous kerogens. All the algaenans so far examined comprise a network of long polymethylenic chains, except for the L race of Botryococcus braunii. The resistant macromolecular material isolated from the latter, termed PRB L, is based on C 40 isoprenoid chains with a lycopane-type skeleton. Recent comparative studies of PRB L and of Botryococcus-derived sediments provided the first example of kerogen formation via the selective preservation of an "isoprenoid" algaenan. The present study is concerned with PRB L pyrolyses in sealed gold tubes under various temperature/time conditions (260-350C, 0.5-69 h). For the conversion rates thus obtained, ranging from 30 to 100%, a complete mass balance of the different families of pyrolysis products was established; most of the C 1 to C 40 pyrolysate constituents were identified and the abundances of the above compounds and their variations with conversion progress were determined. This study thus allowed us (1) to derive further information about PRB L chemical structure (location of the ether bridges, contribution of linear chains and their relationships with the C 40 isoprenoid ones), (2) to determine the behaviour of this isoprenoid algaenan to thermal stress (timing of the formation of the different groups of products then released, nature of the primary cleavages, origin and mode of formation of the secondary products, and further degradations), and (3) to show, in connection with previous studies, that PRB L-derived kerogens should exhibit pronounced differences relative to standard type I kerogens, the latter being based on polymethylenic chains, regarding not only the structure of the generated products but also the timing of oil generation (upward shift of the catagenesis zone).

  12. Culture of the hydrocarbon producing microalga Botryococcus braunii strain Showa: optimal CO2, salinity, temperature, and irradiance conditions.

    PubMed

    Yoshimura, Takeshi; Okada, Shigeru; Honda, Masaki

    2013-04-01

    Specific growth rates and hydrocarbon contents of Botryococcus braunii strain Showa were measured under a wide range of CO2, salinity, temperature, and irradiance conditions. The bubbling CO2 concentration of 0.2-5% and no addition of salinity were favorable conditions for growth. The strain cannot grow at 5C and above 35C under any irradiance levels. Maximum specific growth rate of 0.5 day(-1) (doubling time of 1.4 days), the highest value reported for B. braunii in the past studies, was observed at 30C and 850 ?mol photons m(-2) s(-1). Since hydrocarbon productivity, shown as the product of hydrocarbon content and specific growth rate, increased with the increasing specific growth rate, we conclude that more efficient hydrocarbon production by the mass culture of strain Showa can be achieved by maintaining higher specific growth rate based on the culture conditions presented in this study. PMID:23428820

  13. Characterization of the biofuel potential of a newly isolated strain of the microalga Botryococcus braunii Ktzing from Assam, India.

    PubMed

    Talukdar, Jayanta; Kalita, Mohan Chandra; Goswami, Bhabesh Chandra

    2013-12-01

    Botryococcus braunii GUBIOTJTBB1 was isolated from a freshwater reservoir in Assam, India and its taxonomic identity was confirmed by 18S rRNA sequence analysis. Biofuel potential of the microalga strain was assessed from batch culture under laboratory conditions, based on its lipid content and energy value of the dried biomass. Total lipid of 57.14% and hexane extractable crude hydrocarbon of 52.6% were recorded maximum at 56 and 28 days respectively, which vary upon culture durations. The energy value (54.69 kJ/g) of the strain's sundried biomass was found higher than that of petroleum diesel fuel and nearly twice than other microalgae strains compared. The strain GUBIOTJTBB1 was found superior in terms of total lipid and hydrocarbon contents comparing to the previously reported Indian strains of B. braunii. With further improvements in growth, the strain could become an ideal feedstock for potential biofuel production in the prevailing climatic conditions of the region. PMID:24121368

  14. Low-cost production of green microalga Botryococcus braunii biomass with high lipid content through mixotrophic and photoautotrophic cultivation.

    PubMed

    Yeesang, Chittra; Cheirsilp, Benjamas

    2014-09-01

    Botryococcus braunii is a microalga that is regarded as a potential source of renewable fuel because of its ability to produce large amounts of lipid that can be converted into biodiesel. Agro-industrial by-products and wastes are of great interest as cultivation medium for microorganisms because of their low cost, renewable nature, and abundance. In this study, two strategies for low-cost production of B. braunii biomass with high lipid content were performed: (i) the mixotrophic cultivation using molasses, a cheap by-product from the sugar cane plant as a carbon source, and (ii) the photoautotrophic cultivation using nitrate-rich wastewater supplemented with CO2 as a carbon source. The mixotrophic cultivation added with 15 g L(-1) molasses produced a high amount of biomass of 3.05 g L(-1) with a high lipid content of 36.9 %. The photoautotrophic cultivation in nitrate-rich wastewater supplemented with 2.0 % CO2 produced a biomass of 2.26 g L(-1) and a lipid content of 30.3 %. The benefits of this photoautotrophic cultivation are that this cultivation would help to reduce accumulation of atmospheric carbon dioxide and more than 90 % of the nitrate could be removed from the wastewater. When this cultivation was scaled up in a stirred tank photobioreactor and run with semi-continuous cultivation regime, the highest microalgal biomass of 5.16 g L(-1) with a comparable lipid content of 32.2 % was achieved. These two strategies could be promising ways for producing cheap lipid-rich microalgal biomass that can be used as biofuel feedstocks and animal feeds. PMID:24989454

  15. Monitoring lipid accumulation in the green microalga Botryococcus braunii with frequency-modulated stimulated Raman scattering

    NASA Astrophysics Data System (ADS)

    Wang, Chun-Chin; Chandrappa, Dayananda; Smirnoff, Nicholas; Moger, Julian

    2015-03-01

    The potential of microalgae as a source of renewable energy has received considerable interest because they can produce lipids (fatty acids and isoprenoids) that can be readily converted into biofuels. However, significant research in this area is required to increase yields to make this a viable renewable source of energy. An analytical tool that could provide quantitative in situ spectroscopic analysis of lipids synthesis in individual microalgae would significantly enhance our capability to understand the synthesis process at the cellular level and lead to the development of strategies for increasing yield. Stimulated Raman scattering (SRS) microscopy has great potential in this area however, the pump-probe signal from two-color two-photon absorption of pigments (chlorophyll and carotenoids) overwhelm the SRS signal and prevent its application. Clearly, the development of a background suppression technique is of significant value for this important research area. To overcome the limitation of SRS in pigmented specimens, we establish a frequency-modulated stimulated Raman scattering (FM-SRS) microscopy that eliminates the non-Raman background by rapidly toggling on-and-off the targeted Raman resonance. Moreover, we perform the background-free imaging and analysis of intracellular lipid droplets and extracellular hydrocarbons in a green microalga with FM-SRS microscopy. We believe that FM-SRS microscopy demonstrates the potential for many applications in pigmented cells and provides the opportunity for improved selective visualization of the chemical composition of algae and plants

  16. Effects of different media and nitrogen sources and levels on growth and lipid of green microalga Botryococcus braunii KMITL and its biodiesel properties based on fatty acid composition.

    PubMed

    Ruangsomboon, Suneerat

    2015-09-01

    This work aimed to find an optimum culture medium for green microalga Botryococcus braunii KMITL and investigate its biodiesel properties based on fatty acid composition. Four different media were tested. Chlorella medium was the best medium for lipid yield. Among four nitrogen sources tested, KNO3 produced the highest lipid yield. When varied the nitrogen concentrations, this strain gave the highest lipid yield at the highest nitrogen level. When cultivated in the best medium and nitrogen source and level for 30 days, and then cultivated further for 14 days in the medium with no nitrogen, the highest lipid content and yield were 49.940.82% and 2.710.02 g L(-1), respectively. C16:0 fatty acid was the major fatty acid found. Fatty acid profiles of B. braunii KMITL cultivated in Chlorella medium with 1.25 g L(-1) KNO3 gave the best biodiesel properties with the lowest iodine value, maximum cetane number, and lowest degree of unsaturation. PMID:25677535

  17. Removal of CO{sub 2} from flue gases by algae. [Quarterly] technical report, March 1, 1993--May 31, 1993

    SciTech Connect

    Akin, C.; Pradhan, S.

    1993-09-01

    The objective of this research program is to determine the feasibility of the alga Botryococcus braunii as a biocatalyst for the photosynthetic conversion of flue gas CO{sub 2} to hydrocarbons. The research program involves the determination of the biocatalytic characteristics of free and immobilized cultures of Botryococcus braunii in bench-scale studies, and the feasibility study and economic analysis of the Botryococcus braunii culture systems for the conversion of flue gas CO{sub 2} to hydrocarbons. The objective of the third quarter of this research program was to determine the growth and hydrogen formation characteristics of free and immobilized cells of Botryococcus braunii in bench-scale photobioreactors. Raceway and inclined surface type bioreactors were used for free cell and immobilized cell studies respectively. The free cell studies with air and CO{sub 2} enriched air [10% (v/v) CO{sub 2} in air] in media with and without NaHCO{sub 3} were conducted.

  18. The use of artificial neural network for modelling of phycoremediation of toxic elements As(III) and As(V) from wastewater using Botryococcus braunii

    NASA Astrophysics Data System (ADS)

    Podder, M. S.; Majumder, C. B.

    2016-02-01

    In the present study, a thorough investigation has been done on the removal efficiency of both As(III) and As (V) from synthetic wastewater by phycoremediation of Botryococcus braunii algal biomass. Artificial neural networks (ANNs) are practised for predicting % phycoremediation efficiency of both As(III) and As(V) ions. The influence of several parameters for example initial pH, inoculum size, contact time and initial arsenic concentration (either As(III) or As(V)) was examined systematically. The maximum phycoremediation of As(III) and As(V) was found to be 85.22% and 88.15% at pH 9.0, equilibrium time of 144 h by using algal inoculum size of 10% (v/v) and initial arsenic concentration of 50 mg/L. The data acquired from laboratory scale experimental set up was utilized for training a three-layer feed-forward back propagation (BP) with Levenberg-Marquardt (LM) training algorithm having 4:5:1 architecture. A comparison between the experimental data and model outputs provided a high correlation coefficient (R2all_ANN equal to 0.9998) and exhibited that the model was capable for predicting the phycoremediation of both As(III) and As(V) from wastewater. The network topology was optimized by changing number of neurons in hidden layers. ANNs are efficient to model and simulate highly non-liner multivariable relationships. Absolute error and Standard deviation (SD) with respect to experimental output were calculated for ANN model outputs. The comparison of phycoremediation efficiencies of both As(III) and As(V) between experimental results and ANN model outputs exhibited that ANN model can determine the behaviour of As(III) and As(V) elimination process under various circumstances.

  19. The use of artificial neural network for modelling of phycoremediation of toxic elements As(III) and As(V) from wastewater using Botryococcus braunii.

    PubMed

    Podder, M S; Majumder, C B

    2016-02-15

    In the present study, a thorough investigation has been done on the removal efficiency of both As(III) and As (V) from synthetic wastewater by phycoremediation of Botryococcus braunii algal biomass. Artificial neural networks (ANNs) are practised for predicting % phycoremediation efficiency of both As(III) and As(V) ions. The influence of several parameters for example initial pH, inoculum size, contact time and initial arsenic concentration (either As(III) or As(V)) was examined systematically. The maximum phycoremediation of As(III) and As(V) was found to be 85.22% and 88.15% at pH9.0, equilibrium time of 144h by using algal inoculum size of 10% (v/v) and initial arsenic concentration of 50mg/L. The data acquired from laboratory scale experimental set up was utilized for training a three-layer feed-forward back propagation (BP) with Levenberg-Marquardt (LM) training algorithm having 4:5:1 architecture. A comparison between the experimental data and model outputs provided a high correlation coefficient (R(2)all_ANN equal to 0.9998) and exhibited that the model was capable for predicting the phycoremediation of both As(III) and As(V) from wastewater. The network topology was optimized by changing number of neurons in hidden layers. ANNs are efficient to model and simulate highly non-liner multivariable relationships. Absolute error and Standard deviation (SD) with respect to experimental output were calculated for ANN model outputs. The comparison of phycoremediation efficiencies of both As(III) and As(V) between experimental results and ANN model outputs exhibited that ANN model can determine the behaviour of As(III) and As(V) elimination process under various circumstances. PMID:26615452

  20. Characterization of the heterotrimeric G-protein complex and its regulator from the green alga Chara braunii expands the evolutionary breadth of plant G-protein signaling.

    PubMed

    Hackenberg, Dieter; Sakayama, Hidetoshi; Nishiyama, Tomoaki; Pandey, Sona

    2013-12-01

    The lack of heterotrimeric G-protein homologs in the sequenced genomes of green algae has led to the hypothesis that, in plants, this signaling mechanism coevolved with the embryophytic life cycle and the acquisition of terrestrial habitat. Given the large evolutionary gap that exists between the chlorophyte green algae and most basal land plants, the bryophytes, we evaluated the presence of this signaling complex in a charophyte green alga, Chara braunii, proposed to be the closest living relative of land plants. The C. braunii genome encodes for the entire G-protein complex, the Gα, Gβ, and Gγ subunits, and the REGULATOR OF G-PROTEIN SIGNALING (RGS) protein. The biochemical properties of these proteins and their cross-species functionality show that they are functional homologs of canonical G-proteins. The subunit-specific interactions between CbGα and CbGβ, CbGβ and CbGγ, and CbGα and CbRGS are also conserved, establishing the existence of functional G-protein complex-based signaling mechanisms in green algae. PMID:24179134

  1. Removal of CO{sub 2} from flue gases by algae. Final technical report, September 1, 1992--August 31, 1993

    SciTech Connect

    Akin, C.; Maka, A.; Patel, S.; Conrad, J.; Benemann, J.

    1993-12-31

    The objective of this research program is to determine the feasibility of the alga Botryococcus braunii as a biocatalyst for the photosynthetic conversion of flue gas CO{sub 2} to hydrocarbons. Free and immobilized cells of Botryococcus braunii were grown in aqueous medium supplemented with nitrogen, phosphorus and mineral nutrients. Air and CO{sub 2} enriched air [10% to 15% (V/V) CO{sub 2}] in the gas phase and 0.2% to 2% NaHCO{sub 3} in the liquid medium served as the carbon source. Growth and hydrocarbon formation characteristics of free and immobilized cultures of Botryococcus braunii were determined in bench-scale photobioreactors. Technical and economic feasibility of the conversion of flue gas CO{sub 2} to hydrocarbons by Botryococcus braunii culture systems was evaluated. In free cell systems, the hexane extractable oil productivity was about 15 to 37 grams of oil per 100 grams of cell dry weight. In immobilized cell systems, the oil production ranged between 5% and 47% at different immobilization systems and immobilized surface locations, with an average of 19% of cell biomass dry weight. The feasibility and economic evaluation estimated the cost of oil produced from flue gas CO{sub 2} by algae to range between $45 and $75 per barrel assuming that a hydrocarbon yield of about 50% of the biomass weight is achievable and a credit of $60 per ton of carbon removed is available. A future research program leading to development of a multistage process, consisting of closed systems for heavy inoculum buildup followed by lower cost open systems for oil production is recommended.

  2. Characterization of the Heterotrimeric G-Protein Complex and Its Regulator from the Green Alga Chara braunii Expands the Evolutionary Breadth of Plant G-Protein Signaling1[C][W][OPEN

    PubMed Central

    Hackenberg, Dieter; Sakayama, Hidetoshi; Nishiyama, Tomoaki; Pandey, Sona

    2013-01-01

    The lack of heterotrimeric G-protein homologs in the sequenced genomes of green algae has led to the hypothesis that, in plants, this signaling mechanism coevolved with the embryophytic life cycle and the acquisition of terrestrial habitat. Given the large evolutionary gap that exists between the chlorophyte green algae and most basal land plants, the bryophytes, we evaluated the presence of this signaling complex in a charophyte green alga, Chara braunii, proposed to be the closest living relative of land plants. The C. braunii genome encodes for the entire G-protein complex, the Gα, Gβ, and Gγ subunits, and the REGULATOR OF G-PROTEIN SIGNALING (RGS) protein. The biochemical properties of these proteins and their cross-species functionality show that they are functional homologs of canonical G-proteins. The subunit-specific interactions between CbGα and CbGβ, CbGβ and CbGγ, and CbGα and CbRGS are also conserved, establishing the existence of functional G-protein complex-based signaling mechanisms in green algae. PMID:24179134

  3. Glycine induced culture-harvesting strategy for Botryococcus braunii.

    PubMed

    Shen, Ying; Zhu, Wenzhe; Chen, Chaozhou; Nie, Yilei

    2016-04-01

    The objective of this study was to investigate the effects of culture conditions, including carbon sources and concentration, culture period, and precondition time, on the production of extracellular polymeric substances (EPS) and its influence on microalgal flocculation. EPS are natural high molecule polymer, excreted by microalgae themselves. EPS can accelerate the formation of microbial aggregates through binding cells closely. Organic carbon sources, such as glucose, glycerol, acetate and glycine were compared to select the optimal source to stimulate EPS accumulation. Subsequently, the effect of culture period, glycine dose and precondition time on EPS production and its influence on biomass growth and flocculation efficiency were investigated. As the main parts of EPS, tightly bound EPS were found positively related to suspended solids concentration. However, the loosely bound EPS may weaken the floc structure, leading to poor water-cells separation. Under the optimal condition with culture period of 16 days, glycine dose of 0.5 g l(-1) and precondition time of 5 days, the biomass concentration increased from 1.49 to 2 g l(-1), and the maximum suspended solids concentration of 7.06% with biomass recovery rate of 70.6% was achieved. PMID:26553477

  4. [Diurnal progress of NADP-linked glyceraldehyde-3-phosphate-dehydrogenase in synchronous culture of unicellular green alga Ankistrodesmus braunii and its susceptibility to X-irradiation and inhibitiors of protein synthesis].

    PubMed

    Theiss-Seuberling, H B

    1975-06-22

    1. The daily progress of NADP-linked GPD-activity rise in synchronous culture of Ankistrodesmus braunii was investigated in respect to short time increase of activity by light. After various exposure times cells were temporarily deprived of light and subsequently the so-called dark value as well as the light value (dark value plus light-induced part) of the enzyme activity was determined. 2. The increase of dark and light values per cell number is greater in the first half of the day than in the second. The minor activity rise in the second half seems to be caused by culture conditions since the activity of the light and dark values-after reduction of cell density to half in the early afternoon-shows a greater increase again. With regard to chlorophyll, around noon the enzymes activity reaches a maximum which corresponds to numerous other physiological maxima in synchronous algae cultures. 3. The absolute value of the light-induced part of NADP-linked GPD-activity per cell number also increases with increasing exposure time in the first half of the day more than in the second. 4. X-irradiation retards the rise of the dark value of the NADP-GPD. This is particularly evident if the cells are exposed to light for 4 hrs after X-irradiation: 10-25 krad is enough to completely arrest the rise of the dark value. 5. The light-induced part of GDP-activity is hardly affected by high X-ray doses (424 krad), either immediately following the X-irradiation altered the effect of the irradiation: the rise of the dark value was not as great as the control; the light-induced part of enzyme activity was obviously retarded more than it had been after only 4 hrs exposure time. Thus it can be assumed that with regard to the dark value of GPD-activity there is a recovery from the irradiation damage, whereas the radiation effect on the light-induced part of GDP-activity is possibly increased. 8. The D37 of chlorophyll synthesis of synchronous Ankistrodesmus cultures is approximately 85 krad and is thus, like the rise of the light-induced increase of NADP-linked GPD-activity, substantially more radiation resistent than the rise of the dark value which for a plant organism is extremely sensitive. 9. The high radiation sensitivity of the dark value rise of the GPD-activity in Ankistrodesmus braunii is compared with the relatively radiation resistent rise of this enzyme activity in resting greening Euglena gracilis, which contrary to Ankistrodesmus is not retarded by actinomycine, but only by chloramphenicol. One of the hypotheses under discussion regarding the X-ray effect is that the transcription processes which probably occur additionally for the rise in activity of the dark value of NADP-linked GPD may be the particularly radiation sensitive processes in Ankistrodesmus braunii. PMID:808190

  5. Overall Energy Considerations for Algae Species Comparison and Selection in Algae-to-Fuels Processes

    SciTech Connect

    Link, D.; Kail, B.; Curtis, W.; Tuerk,A.

    2011-01-01

    The controlled growth of microalgae as a feedstock for alternative transportation fuel continues to receive much attention. Microalgae have the characteristics of rapid growth rate, high oil (lipid) content, and ability to be grown in unconventional scenarios. Algae have also been touted as beneficial for CO{sub 2} reuse, as algae can be grown using CO{sub 2} emissions from fossil-based energy generation. Moreover, algae does not compete in the food chain, lessening the 'food versus fuel' debate. Most often, it is assumed that either rapid production rate or high oii content should be the primary factor in algae selection for algae-to-fuels production systems. However, many important characteristics of algae growth and lipid production must be considered for species selection, growth condition, and scale-up. Under light limited, high density, photoautotrophic conditions, the inherent growth rate of an organism does not affect biomass productivity, carbon fixation rate, and energy fixation rate. However, the oil productivity is organism dependent, due to physiological differences in how the organisms allocate captured photons for growth and oil production and due to the differing conditions under which organisms accumulate oils. Therefore, many different factors must be considered when assessing the overall energy efficiency of fuel production for a given algae species. Two species, Chlorella vulgaris and Botryococcus braunii, are popular choices when discussing algae-to-fuels systems. Chlorella is a very robust species, often outcompeting other species in mixed-culture systems, and produces a lipid that is composed primarily of free fatty acids and glycerides. Botryococcus is regarded as a slower growing species, and the lipid that it produces is characterized by high hydrocarbon content, primarily C28-C34 botryococcenes. The difference in growth rates is often considered to be an advantage oiChlorella. However, the total energy captured by each algal species in the same photobioreactor system should be similar at light limited growth conditions based on photon flux. It is how the algae 'allocate' this energy captured that will vary: Data will be presented that shows that Botryococcus invests greater energy in oil production than Chlorella under these growth conditions. In essence, the Chlorella can grow 'fast and lean' or can be slowed to grow 'slow and fat'. The overall energy potential between the Chlorella and Botryococcus, then, becomes much more equivalent on a per-photon basis. This work will indicate an interesting relationship between two very different algae species, in terms of growth rate, lipid content and composition, and energy efficiency of the overall process. The presentation will indicate that in light-limited growth, it cannot be assumed that either rapid growth rate or lipid production rate can be used as stand-alone indicators of which species-lipid relationships will truly be more effective in algae-to-fuels scenarios.

  6. Removal of CO{sub 2} from flue gases by algae. Technical report, December 1, 1992--February 28, 1993

    SciTech Connect

    Akin, C.; Maka, A.; Pradhan, S.; Banerjee, D.

    1993-05-01

    The studies reported here confirmed our preliminary observations that Botryococcus braunii can tolerate and grow well in flue gas CO{sub 2} concentrations of 10 to 15%, and produce oil. The highest extracted oil was observed in 10% CO{sub 2} enriched air. Initial pH of the medium at or near 10 pH is favorable to cell growth probably by stimulating the CO{sub 2} solubilization in the medium. This is also indicated in Botryococcus braunii growth and oil formation in NaHCO{sub 3} added medium. The lack of growth in Na{sub 2}CO{sub 3} containing media was probably due to high pH. The CaCO{sub 3} precipitation from the CA{sup ++} gelled alginate beads indicate the need for alternative immobilization systems. But the attachment of the Botryococcus braunii cells to the bottom inner surfaces of the photobioreactors may eliminate the need for gel entrapment systems as the immobilization matrices. Attachment of the Botryococcus braunii cells to the bottom inner surfaces of the photobioreactors, rather than remaining in the suspension, reduces the significance of self shadowing and related liquid height (thickness) effect. The capability of Botryococcus braunii to grow in NaHCO{sub 3} solutions is very encouraging toward development of an alkaline scrubbing system for the flue gas followed by removal of the CO{sub 2} from the alkaline solution. In such a system the pH 10 is the currently observed upper limit.

  7. Chemical structure of the organic matter in a Pliocene maar-type shale: Implicated Botryococcus race strains and formation pathways

    NASA Astrophysics Data System (ADS)

    Derenne, Sylvie; Largeau, Claude; Hetnyi, Magdolna; Brukner-Wein, Alice; Connan, Jacques; Lugardon, Bernard

    1997-05-01

    A maar-type Pliocene oil shale from Pula (Hungary) was examined by Scanning and Transmission Electron Microscopy (SEM, TEM) bitumen analysis, spectroscopic analyses (FTIR, solid state 13C NMR) and pyrolytic analyses of insoluble material. The investigated samples, corresponding to the "massive section" of Pula deposit, exhibit TOC values ranging from 18 to 42%, and Rock-Eval analysis indicated that such samples are comprised of low maturity type I kerogen. Electron Microscopy observations confirmed that recognizable microfossils in this organic matter-rich material almost exclusively correspond to Botryococcus braunii colonies, the morphology of which is perfectly retained. Identification of bitumen and pyrolysate constituents (hydrocarbons, ketones, fatty acids), along with morphological and spectroscopic features, indicate (1) that B. braunii provided a major input to the most organic matter-rich section of Pula oil shale; (2) that both the n-alkadienes-producing and the lycopadiene-producing strains ( A and L, respectively) were present; (3) that the selective preservation of the insoluble and non-hydrolysable macromolecules building up B. braunii outer walls was by far the main process in the formation of this material; (4) that such a process, along with B. braunii prolific growth in the favourable environment that occurred in the crater lake, accounts for the very high TOC and oil potential of Pula deposit; and (5) that the condensation of high molecular weight ether lipids from the A race and of some bacterial lipids also likely contributed to Pula kerogen formation.

  8. Algae.

    PubMed

    Raven, John A; Giordano, Mario

    2014-07-01

    Algae frequently get a bad press. Pond slime is a problem in garden pools, algal blooms can produce toxins that incapacitate or kill animals and humans and even the term seaweed is pejorative - a weed being a plant growing in what humans consider to be the wrong place. Positive aspects of algae are generally less newsworthy - they are the basis of marine food webs, supporting fisheries and charismatic marine megafauna from albatrosses to whales, as well as consuming carbon dioxide and producing oxygen. Here we consider what algae are, their diversity in terms of evolutionary origin, size, shape and life cycles, and their role in the natural environment and in human affairs. PMID:25004359

  9. Evaluation of different solvent mixtures in esterifiable lipids extraction from microalgae Botryococcus braunii for biodiesel production.

    PubMed

    Hidalgo, Pamela; Ciudad, Gustavo; Navia, Rodrigo

    2016-02-01

    Non-polar and polar solvents as well as their mixtures were tested for the extraction of microalgae lipids and thus, to evaluate their effect on total and esterifiable lipids extraction yields with potential to be converted to biodiesel. The obtained results show an increase in lipids and esterifiable lipids extraction yields when non-polar and polar solvent mixtures were used. The higher esterifiable lipids extraction yield was 19.2%wt (based on dry biomass) using a chloroform-methanol mixture (75%v/v of methanol), corresponding to a 98.9%wt esterifiable lipids extraction. In addition, esterifiable lipids extraction yield of 18.9%wt (based on dry biomass) was obtained when a petroleum ether-methanol mixture (75%v/v of methanol) was used, corresponding to a 96.9%wt esterifiable lipids extraction. PMID:26639615

  10. Low polarity pyrolysis products of Permian to Recent Botryococcus-rich sediments: First evidence for the contribution of an isoprenoid algaenan to kerogen formation

    NASA Astrophysics Data System (ADS)

    Derenne, S.; Largeau, C.; Behar, F.

    1994-09-01

    Hydrocarbon identification led to the recognition of three distinct chemical races in the green microalga Botryococcus braunii. These three races (A, B, and L) also show pronounced differences in the chemical structure of the algaenans, i.e., the insoluble, highly aliphatic, nonhydrolysable macromolecular constituents (termed PRB) of their outer walls. PRB A and PRBB are based upon polymethylenic chains, while PRB L is based on C40 isoprenoid moieties. Previous studies demonstrated that the selective preservation of PRB A and/or PRB B played a major role in the genesis of various Botryococcus-derived kerogens; in sharp contrast, the above kerogens did not show any indices of a PRB L contribution. The main purpose of this study was therefore to examine, via the screening of a number of Botryococcus-derived kerogens, if some contribution of PRB L, i.e., of an "isoprenoid algaenan", could be observed. To this end, the pyrolysis products of the three PRB and of seven Botryococcus-rich kerogens were examined. Parallel study of the algaenans of the three races of B. braunii indicated that a clear-cut distinction can be made, by analysis of low polarity pyrolysis products, between PRB A and PRB B, on the one hand, and PRB L, on the other hand. Thereafter, identification of the low polarity pyrolysis products of Botryococcus-rich kerogens revealed some contribution of the L race, along with the A or B race, in three samples out of seven: a Pliocene Torbanite and two Recent sediments. These observations thus provided the first example of the formation of kerogen fractions by the selective preservation of an algaenan based on isoprenoid chains. But they also revealed that important transformations of such chains can take place during kerogen early diagenesis. In sharp contrast, examination of the four Palaeozoic Torbanites revealed a complete lack of isoprenoid moieties, and hence no evidence of PRB L contribution. Comparison of n-alkane/n-alk-1-ene doublet distribution in the pyrolysate of these four kerogens, derived from the A and/or B races, showed some differences in their degree of maturation and in the contribution of higher plant materials to their formation.

  11. Performance of an enzymatic extract in Botrycoccus braunii cell wall disruption.

    PubMed

    Ciudad, Gustavo; Rubilar, Olga; Azcar, Laura; Toro, Claudio; Cea, Mara; Torres, lvaro; Ribera, Alejandra; Navia, Rodrigo

    2014-01-01

    Microalgae can produce and contain lipids, proteins and carbohydrates, which can be extracted and marketed as potential novel added-value bio-products. However, microalgae cell wall disruption is one of the most important challenges involved while processing this type of biomass. In this context, white-rot fungi, responsible for the biodegradation of lignin present in wood due to non-specific extracellular enzymes, could be applied for promoting microalgae cell wall degradation. Therefore, the aim of this study was to evaluate the use of an enzymatic extract produced by the white-rot fungi Anthracophyllum discolor as a biotechnological tool for Botryococcus braunii cell wall disruption. The fungus was inoculated in wheat grains and manganese peroxidase (MnP) activity was monitored while obtaining the enzymatic extract. Then, cell wall disruption trials with different MnP activity were evaluated by the biochemical methane potential (BMP). In relation to cell wall disruption, it was observed that the optimal value was obtained with enzymatic concentration of 1000 U/L with a BMP of 521 mL CH4/g VS. Under these conditions almost 90% of biomass biodegradability was observed, increasing in 62% compared to the microalgae without treatment. Therefore, the results indicate that enzymes secreted by A. discolor promoted the attack of the different cell wall components finally weakening it. Therefore, the application of this treatment could be a promissory biotechnological approach to decrease the energetic input required for the cell wall disruption step. PMID:23899898

  12. Heterotrimeric G-proteins in green algae

    PubMed Central

    Hackenberg, Dieter; Pandey, Sona

    2014-01-01

    Heterotrimeric G-proteins (G-proteins, hereafter) are important signaling components in all eukaryotes. The absence of these proteins in the sequenced genomes of Chlorophycean green algae has raised questions about their evolutionary origin and prevalence in the plant lineage. The existence of G-proteins has often been correlated with the acquisition of embryophytic life-cycle and/or terrestrial habitats of plants which occurred around 450 million years ago. Our discovery of functional G-proteins in Chara braunii, a representative of the Charophycean green algae, establishes the existence of this conserved signaling pathway in the most basal plants and dates it even further back to 1–1.5 billion years ago. We have now identified the sequence homologs of G-proteins in additional algal families and propose that green algae represent a model system for one of the most basal forms of G-protein signaling known to exist to date. Given the possible differences that exist between plant and metazoan G-protein signaling mechanisms, such basal organisms will serve as important resources to trace the evolutionary origin of proposed mechanistic differences between the systems as well as their plant-specific functions. PMID:24614119

  13. The Study of Algae

    ERIC Educational Resources Information Center

    Rushforth, Samuel R.

    1977-01-01

    Included in this introduction to the study of algae are drawings of commonly encountered freshwater algae, a summary of the importance of algae, descriptions of the seven major groups of algae, and techniques for collection and study of algae. (CS)

  14. The oleaginous Botryococcus from the Triassic Yanchang Formation in Ordos Basin, Northwestern China: Morphology and its paleoenvironmental significance

    NASA Astrophysics Data System (ADS)

    Ji, Li-ming; Yan, Kui; Meng, Fan-wei; Zhao, Min

    2010-05-01

    High abundance but rather low diversity algal fossils were found in the hydrocarbon source rocks of the Ch 7-2-Ch 7-3 section, Triassic Yanchang Formation in the Xifeng area of southwest Ordos Basin, which are mainly composed of prolific Leiosphaeridia and Botryococcus. Botryococcus colonies are of various forms; the majority is nubbly, with some of cluster and cotton shape. The nubbly colonies appear globular, cordiform, ternate petal, obtuse triangle, chrysanthemum shape and so on. Most Botryococcus are saffron or brown and are frequently covered with clay under transmission microscope, and shows strong yellow and light brown under fluorescence microscope. Botryococcus could live in freshwater and brackish water. The Botryococcus colonies that lived in fresh water are small with small single cells arranged radially, with undulant or indented edges. The Botryococcus colonies that lived in brackish water are bigger, with larger single cells arranged irregularly, with slippery contours. The most of Botryococcus are discovered from the organic-rich argillaceous sediment with abundant pyrites in the semi- and deep-lake facies, and shows they were preserved in low-energy reducing environments. Taphonomic characteristics of various microfossils and the present of Pediastrum in the phytoplankton flora indicate that they are in situ or near burial. The lake area of the Ordos Basin was gradually expanding and reaching its most extensive flood surface in the Ch 7 of Yanchang Formation interval during the Middle and Late Triassic, with warm climate, plentiful rainfall, and luxuriant vegetation, as determined by the environmental analysis with Botryococcus in Xifeng area. The presence of two ecological types of Botryococcus indicates that the salinity of lake water was fluctuating in the Ch 7 interval. The occurrence of symbiotic acritarchs and geochemical salinity indices show that the Ordos Lake was a typical fresh-water lake, which was gradually desalted, and its salinity fluctuation was narrow during the Mid-Later Triassic. The ecological type of the palynological flora discovered from the Ch 7 to Ch 8 in Xifeng area is similar to that from the Fuxian Lake, with abundant Botryococcus in the Yungui Plateau of China. These findings imply that the Ordos Basin was in a lower-latitude area of temperate to subtropical climate during the Middle and Late Triassic.

  15. Phytochemical screening and anticonvulsant studies of ethyl acetate fraction of Globimetula braunii on laboratory animals

    PubMed Central

    Aliyu, Musa Mumammad; Musa, Abdullahi Isma'il; Kamal, Muhammad Ja'afar; Mohammed, Magaji Garba

    2014-01-01

    Objective To investigate the phytochemical properties and the anticonvulsant potential of the ethyl acetate soluble fraction of ethanol leaf extract of Globimetula braunii, a plant used in ethnomedicine for the treatment of epilepsy. Methods The phytochemical screening was carried out using standard protocol while the anticonvulsant activity was studied using maximal electroshock test in chicks, pentylenetetrazole and 4-aminopyridine-induced seizures in mice. Results The preliminary phytochemical screening carried out on the crude ethanol extract revealed the presence of saponins, carbohydrates, flavonoids, tannins, anthraquinones and steroids. Similarly, tannins, flavonoids and steroids/terpenes were found to be present in the ethyl acetate fraction. In the pharmacological screening, 150 mg/kg of the fraction protected 83.33% of animals against pentylenetetrazole-induced seizure in mice whereas sodium valproate a standard anti-epileptic drug offered 100% protection. In the 4-aminopyridine-induced seizure model, the fraction produced a significant (P<0.05) increase in the mean onset of seizure in unprotected animals. The fraction did not exhibit a significant activity against maximal electroshock convulsion. The median lethal dose of the fraction was found to be 1?261.91 mg/kg. Conclusions These results suggest that the ethyl acetate fraction of Globimetula braunii leaves extract possesses psychoactive compound that may be useful in the management of petit mal epilepsy and lend credence to the ethnomedical use of the plant in the management of epilepsy. PMID:25182552

  16. Elemental composition and molecular structure of Botryococcus alginite in Westphalian cannel coals from Kentucky

    USGS Publications Warehouse

    Mastalerz, Maria; Hower, J.C.

    1996-01-01

    Botryococcus-derived alginites from the Westphalian Skyline, No. 5 Block, Leatherwood (eastern Kentucky) and Breckinridge (western Kentucky) coal beds have been analyzed for elemental composition and functional group distribution using an electron microprobe and micro-FTIR, respectively. The alginites from Kentucky show a carbon range of 81.6 to 92% and oxygen content of 3.5 to 9.5%. Sulphur content ranges from 0.66 to 0.84% and Fe, Si, Al and Ca occur in minor quantities. FTIR analysis demonstrates dominant CH2, CH3 bands and subordinate aromatic carbon in all alginites. The major differences between alginites are in the ratios of CH2 and CH3 groups and ratios between aromatic bands in the out-of-plane region. These differences suggest that, although the ancient Botryococcus derives from a selective preservation of a resistant polymer, it undergoes molecular and some elemental changes through the rank equivalent to vitrinite reflectance of 0.5-0.85%. Other differences, such as intensities of ether bridges and those of carboxyl/carbonyl groups, are attributed to differences in depositional environments.

  17. Blue-green algae

    MedlinePLUS

    ... Talk with your health provider.Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs)Blue-green algae might slow blood clotting. Taking blue-green algae along with medications that ...

  18. Alkaloids in Marine Algae

    PubMed Central

    Gven, Kas?m Cemal; Percot, Aline; Sezik, Ekrem

    2010-01-01

    This paper presents the alkaloids found in green, brown and red marine algae. Algal chemistry has interested many researchers in order to develop new drugs, as algae include compounds with functional groups which are characteristic from this particular source. Among these compounds, alkaloids present special interest because of their pharmacological activities. Alkaloid chemistry has been widely studied in terrestrial plants, but the number of studies in algae is insignificant. In this review, a detailed account of macro algae alkaloids with their structure and pharmacological activities is presented. The alkaloids found in marine algae may be divided into three groups: 1. Phenylethylamine alkaloids, 2. Indole and halogenated indole alkaloids, 3. Other alkaloids. PMID:20390105

  19. Responses of certain freshwater planktonic algae to fluoride

    SciTech Connect

    Hekman, W.E.; Budd, K.; Palmer, G.R.; MacArthur, J.D.

    1984-06-01

    The effects of dissolved fluoride supplied as NaF at up to 150 p.p.m. F/sup -/ (7.9 mM) on growth, photosynthesis, dark respiration, enolase activity and fluoride uptake were determined for six phytoplankters: Synechococcus leopoliensis (Racib.) Komarek (Cyanophyta), Oscillatoria limnetica Lemmermann (Cyanophyta), Ankistrodesmus braunii Brun (Chlorophyta), Scenedesmus quadricauda (Turp.) Breb. (Chlorophyta), Cyclotella meneghiniana Kuetzing (Bacillariophyta) and Stephanodiscus minutus Grun. ex Cleve et Moll (Bacillariophyta). Growth (determined by absorbance at 660 nm or by cell-numbers) was unaffected by fluoride at up to 50 p.p.m. (2.6 mN) in all algae except S. leopoliensis. These effects showed a threshold at ca. 25 p.p.m. (1.3 mM) F/sup -/ and increased with increasing F/sup -/ concentration above this threshold. Photosynthetic O/sub 2/ evolution in the chlorophytes was unaffected by F/sup -/ at up to 50 p.p.m., whereas in S. leopoliensis F/sup -/ above ca. 25 p.p.m. caused a concentration-dependent inhibition of photosynthesis which was most pronounced at saturating irradiance. Dark O/sub 2/ uptake was unaffected at up to 50 p.p.m. in chlorophytes but was stimulated in S. leopoliensis. Enolase in clarified cell-extracts of all six algae was inhibited by F/sup -/, with K/sub i/ values ranging from 27 to 319 ..mu..M. Fluorine (measured by proton-induced gamma-ray emission) could not be detected in chlorophytes exposed during growth to up to 50 p.p.m. F/sup -/, but was detected in S. leopoliensis, O. limnetica and C. meneghiniana. Fluorine associated with cells of these algae increased as the external F/sup -/ concentration increased.

  20. Heterotrimeric G proteins in green algae: an early innovation in the evolution of the plant lineage.

    PubMed

    Hackenberg, Dieter; Pandey, Sona

    2014-01-01

    Heterotrimeric G-proteins (G-proteins, hereafter) are important signaling components in all eukaryotes. The absence of these proteins in the sequenced genomes of Chlorophyaceaen green algae has raised questions about their evolutionary origin and prevalence in the plant lineage. The existence of G-proteins has often been correlated with the acquisition of embryophytic life-cycle and/or terrestrial habitats of plants which occurred around 450 million years ago. Our discovery of functional G-proteins in Chara braunii, a representative of the Charophycean green algae, establishes the existence of this conserved signaling pathway in the most basal plants and dates it even further back to 1-1.5 billion years ago. We have now identified the sequence homologs of G-proteins in additional algal families and propose that green algae represent a model system for one of the most basal forms of G-protein signaling known to exist to date. Given the possible differences that exist between plant and metazoan G-protein signaling mechanisms, such basal organisms will serve as important resources to trace the evolutionary origin of proposed mechanistic differences between the systems as well as their plant-specific functions. PMID:24614119

  1. ALGAE AND WATER POLLUTION

    EPA Science Inventory

    Algae are involved in water pollution in a number of important ways. It requires a continuous monitoring and study of algae existing in waters of various quality in order to determine what controls or what changes or what uses can be instituted for the benefit of man and for cons...

  2. Characterization of the Reversible Inactivation of Ankistrodesmus braunii Nitrate Reductase by Hydroxylamine 1

    PubMed Central

    Balandin, Teresa; Fernndez, Victor M.; Aparicio, Pedro J.

    1986-01-01

    The photoreversible nature of the regulation of nitrate reductase is one of the most interesting features of this enzyme. As well as other chemicals, NH2OH reversibly inactivates the reduced form of nitrate reductase from Ankistrodesmus braunii. From the partial activities of the enzyme, only terminal nitrate reductase is affected by NH2OH. To demonstrate that the terminal activity was readily inactivted by NH2OH, the necessary reductants of the terminal part of the enzyme had to be cleared of dithionite since this compound reacts chemically with NH2OH. Photoreduced flavins and electrochemically reduced methyl viologen sustain very effective inactivation of terminal nitrate reductase activity, even if the enzyme was previously deprived of its NADH-dehydrogenase activity. The early inhibition of nitrate reductase by NH2OH appears to be competitive versus NO3?. Since NO3?, as well as cyanate, carbamyl phosphate and azide (competitive inhibitors of nitrate reductase versus NO3?), protect the enzyme from NH2OH inactivation, it is suggested that NH2OH binds to the nitrate active site. The NH2OH-inactivated enzyme was photoreactivated in the presence of flavins, although slower than when the enzyme was previously inactivated with CN?. NH2OH and NADH concentrations required for full inactivation of nitrate reductase appear to be low enough to potentially consider this inactivation process of physiological significance. PMID:16665024

  3. Anticoagulant effect of marine algae.

    PubMed

    Kim, Se-Kwon; Wijesekara, Isuru

    2011-01-01

    Recently, a great deal of interest has been developed in the nutraceutical and pharmaceutical industries to isolate natural anticoagulant compounds from marine resources. Among marine resources, marine algae are valuable sources of novel bioactive compounds with anticoagulant effect. Phlorotannins and sulfated polysaccharides such as fucoidans in brown algae, carrageenans in red algae, and ulvans in green algae have been recognized as potential anticoagulant agents. Therefore, marine algae-derived phlorotannins and SPs have great potential for developing as anticoagulant drugs in nutraceutical and pharmaceutical areas. This chapter focuses on the potential anticoagulant agents in marine algae and presents an overview of their anticoagulant effect. PMID:22054951

  4. Genetically Modified Bacteria for Fuel Production: Development of Rhodobacteria as a Versatile Platform for Fuels Production

    SciTech Connect

    2010-07-01

    Electrofuels Project: Penn State is genetically engineering bacteria called Rhodobacter to use electricity or electrically generated hydrogen to convert carbon dioxide into liquid fuels. Penn State is taking genes from oil-producing algae called Botryococcus braunii and putting them into Rhodobacter to produce hydrocarbon molecules, which closely resemble gasoline. Penn State is developing engineered tanks to support microbial fuel production and determining the most economical way to feed the electricity or hydrogen to the bacteria, including using renewable sources of power like solar energy.

  5. Molecular composition and mobility of torbanite precursors: Implications for the structure of coal

    USGS Publications Warehouse

    Wilson, M.A.; Batts, B.D.; Hatcher, P.G.

    1988-01-01

    Coorongite, a torbanite precursor found in South Australia, and algal residues derived from Botryococcus braunii and other algae have been examined by solid-state 13C NMR techniques. The majority of carbon in these materials is present as (CH2)n. However, variable-temperature studies show that a considerable proportion of the alkyl chains have unusual dipolar-dephasing behavior and are more mobile than in rigid solids. It is suggested that these mobile structures contribute to the so-called "guest phases" in coal. The data are also consistent with a vascular and algal model of coal. ?? 1988 American Chemical Society.

  6. Clocks in algae.

    PubMed

    Noordally, Zeenat B; Millar, Andrew J

    2015-01-20

    As major contributors to global oxygen levels and producers of fatty acids, carotenoids, sterols, and phycocolloids, algae have significant ecological and commercial roles. Early algal models have contributed much to our understanding of circadian clocks at physiological and biochemical levels. The genetic and molecular approaches that identified clock components in other taxa have not been as widely applied to algae. We review results from seven species: the chlorophytes Chlamydomonas reinhardtii, Ostreococcus tauri, and Acetabularia spp.; the dinoflagellates Lingulodinium polyedrum and Symbiodinium spp.; the euglenozoa Euglena gracilis; and the red alga Cyanidioschyzon merolae. The relative simplicity, experimental tractability, and ecological and evolutionary diversity of algal systems may now make them particularly useful in integrating quantitative data from "omic" technologies (e.g., genomics, transcriptomics, metabolomics, and proteomics) with computational and mathematical methods. PMID:25379817

  7. Heterotrimeric G-proteins in green algae. An early innovation in the evolution of the plant lineage.

    PubMed

    Hackenberg, Dieter; Pandey, Sona

    2014-01-01

    Heterotrimeric G-proteins (G-proteins, hereafter) are important signaling components in all eukaryotes. The absence of these proteins in the sequenced genomes of Chlorophycean green algae has raised questions about their evolutionary origin and prevalence in the plant lineage. The existence of G-proteins has often been correlated with the acquisition of embryophytic life-cycle and/or terrestrial habitats of plants which occurred around 450 million years ago. Our discovery of functional G-proteins in Chara braunii, a representative of the Charophycean green algae, establishes the existence of this conserved signaling pathway in the most basal plants and dates it even further back to 1-1.5 billion years ago. We have now identified the sequence homologs of G-proteins in additional algal families and propose that green algae represent a model system for one of the most basal forms of G-protein signaling known to exist to date. Given the possible differences that exist between plant and metazoan G-protein signaling mechanisms, such basal organisms will serve as important resources to trace the evolutionary origin of proposed mechanistic differences between the systems as well as their plant-specific functions. PMID:25764428

  8. Genomics of Volvocine Algae

    PubMed Central

    Umen, James G.; Olson, Bradley J.S.C.

    2015-01-01

    Volvocine algae are a group of chlorophytes that together comprise a unique model for evolutionary and developmental biology. The species Chlamydomonas reinhardtii and Volvox carteri represent extremes in morphological diversity within the Volvocine clade. Chlamydomonas is unicellular and reflects the ancestral state of the group, while Volvox is multicellular and has evolved numerous innovations including germ-soma differentiation, sexual dimorphism, and complex morphogenetic patterning. The Chlamydomonas genome sequence has shed light on several areas of eukaryotic cell biology, metabolism and evolution, while the Volvox genome sequence has enabled a comparison with Chlamydomonas that reveals some of the underlying changes that enabled its transition to multicellularity, but also underscores the subtlety of this transition. Many of the tools and resources are in place to further develop Volvocine algae as a model for evolutionary genomics. PMID:25883411

  9. Turning moss into algae

    PubMed Central

    Antimisiaris, Marika F; Running, Mark P

    2014-01-01

    Prenylation is a series of lipid posttranslational modifications that are involved in several key aspects of plant development. We recently knocked out every prenylation subunit in Physcomitrella patens. Like in Arabidopsis, knockout of protein farnesyltransferase and protein geranylgeranyltransferase in P. patens does not result in lethality; however, effects on development are extensive. In particular, the knockout of protein geranylgeranyltransferase results in small unicellular plants that resemble algae. Here we perform an analysis of predicted geranylgeranyltransferase target proteins in P. patens, and draw attention to those most likely to play a role in the knockout phenotype. PMID:25763501

  10. TOXIC ALGAE IN SOUTHEASTERN AQUACULTURE SYSTEMS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxin-producing algae are common in aquaculture facilities. Three divisions of algae have been identified as producing toxins: cyanobacteria, prymnesiophytes, and euglenoid algae. Cyanobacteria produce the most diverse forms including hepatic and neurologic forms. Prymnesin toxin is confined to ...

  11. Miocene Coralline algae

    SciTech Connect

    Bosence, D.W.J.

    1988-01-01

    The coralline algae (Order Corallinales) were sedimentologically and ecologically important during the Miocene, a period when they were particularly abundant. The many poorly described and illustrated species and the lack of quantitative data in coralline thalli make specific determinations particularly difficult, but some species are well known and widespread in the Tethyan area. The sedimentologic importance of the Miocene coralline algae is reflected in the abundance of in-situ coralline buildups, rhodoliths, and coralline debris facies at Malta and Spain; similar sequences are known throughout the Tethyan Miocene. In-situ buildups vary from leafy crustose biostromes to walled reefs with dense coralline crusts and branches. Growth forms are apparently related to hydraulic energy. Rhodoliths vary from leafy, crustose, and open-branched forms in muddy sediments to dense, crustose, and radial-branching forms in coarse grainstones. Rhodolith form and internal structure correlate closely with hydraulic energy. Coralline genera are conservative and, as such, are useful in paleoenvironmental analysis. Of particular interest are the restricted depth ranges of recent coralline genera. More research is needed on the sedimentology, paleoecology, and systematics of the Cenozoic corallines, as they have particular value in paleoenvironmental analysis.

  12. Giant viruses infecting algae.

    PubMed

    Van Etten, J L; Meints, R H

    1999-01-01

    Paramecium bursaria chlorella virus (PBCV-1) is the prototype of a family of large, icosahedral, plaque-forming, double-stranded-DNA-containing viruses that replicate in certain unicellular, eukaryotic chlorella-like green algae. DNA sequence analysis of its 330, 742-bp genome leads to the prediction that this phycodnavirus has 376 protein-encoding genes and 10 transfer RNA genes. The predicted gene products of approximately 40% of these genes resemble proteins of known function. The chlorella viruses have other features that distinguish them from most viruses, in addition to their large genome size. These features include the following: (a) The viruses encode multiple DNA methyltransferases and DNA site-specific endonucleases; (b) PBCV-1 encodes at least part, if not the entire machinery to glycosylate its proteins; (c) PBCV-1 has at least two types of introns--a self-splicing intron in a transcription factor-like gene and a splicesomal processed type of intron in its DNA polymerase gene. Unlike the chlorella viruses, large double-stranded-DNA-containing viruses that infect marine, filamentous brown algae have a circular genome and a lysogenic phase in their life cycle. PMID:10547698

  13. Ecology of Harmful Algae

    NASA Astrophysics Data System (ADS)

    Roelke, Daniel L.

    2007-07-01

    Edna Graneli and Jefferson T. Turner, Editors;Ecological Studies Series, Vol. 189; Springer; ISBN 3540322094; 413 pp.; 2006; $195 Harmful algal blooms (HABs) affect commercially and recreationally important species, human health, and ecosystem functioning. Hallmark events are the visually stunning blooms where waters are discolored and filled with ichthyotoxin-producing algae that lead to large fish kills. Of most concern, however, are HABs that pose a threat to human health. For example, some phycotoxins bioaccumulate in the guts and tissues of commercially and recreationally important species that when consumed by humans, may result in nausea, paralysis, memory loss, and even death. In addition to the deleterious impacts of phycotoxins, HABs can be problematic in other ways. For example, the decay of blooms often leads to low dissolved oxygen in subsurface waters. Blooms also reduce light penetration into the water column. Both processes disrupt ecosystems and in some cases have completely destroyed benthic communities.

  14. Fuel From Algae: Scaling and Commercialization of Algae Harvesting Technologies

    SciTech Connect

    2010-01-15

    Broad Funding Opportunity Announcement Project: Led by CEO Ross Youngs, AVS has patented a cost-effective dewatering technology that separates micro-solids (algae) from water. Separating micro-solids from water traditionally requires a centrifuge, which uses significant energy to spin the water mass and force materials of different densities to separate from one another. In a comparative analysis, dewatering 1 ton of algae in a centrifuge costs around $3,400. AVS’s Solid-Liquid Separation (SLS) system is less energy-intensive and less expensive, costing $1.92 to process 1 ton of algae. The SLS technology uses capillary dewatering with filter media to gently facilitate water separation, leaving behind dewatered algae which can then be used as a source for biofuels and bio-products. The biomimicry of the SLS technology emulates the way plants absorb and spread water to their capillaries.

  15. [From algae to "functional foods"].

    PubMed

    Vadal, M; Palmieri, B

    2015-01-01

    In the recent years, a growing interest for nutraceutical algae (tablets, capsules, drops) has been developed, due to their effective health benefits, as a potential alternative to the classic drugs. This review explores the use of cyanobacterium Spirulina, the microalgae Chlorella, Dunaliella, Haematococcus, and the macroalgae Klamath, Ascophyllum, Lithothamnion, Chondrus, Hundaria, Glacilaria, Laminaria, Asparagopsis, Eisenia, Sargassum as nutraceuticals and dietary supplements, in terms of production, nutritional components and evidence-based health benefits. Thus, our specific goals are: 1) Overview of the algae species currently used in nutraceuticals; 2) Description of their characteristics, action mechanisms, and possible side effects; 3) Perspective of specific algae clinical investigations development. PMID:26378764

  16. Transgenic algae engineered for higher performance

    DOEpatents

    Unkefer, Pat J; Anderson, Penelope S; Knight, Thomas J

    2014-10-21

    The present disclosure relates to transgenic algae having increased growth characteristics, and methods of increasing growth characteristics of algae. In particular, the disclosure relates to transgenic algae comprising a glutamine phenylpyruvate transaminase transgene and to transgenic algae comprising a glutamine phenylpyruvate transaminase transgene and a glutamine synthetase.

  17. Logistic analysis of algae cultivation.

    PubMed

    Slegers, P M; Leduc, S; Wijffels, R H; van Straten, G; van Boxtel, A J B

    2015-03-01

    Energy requirements for resource transport of algae cultivation are unknown. This work describes the quantitative analysis of energy requirements for water and CO2 transport. Algae cultivation models were combined with the quantitative logistic decision model 'BeWhere' for the regions Benelux (Northwest Europe), southern France and Sahara. For photobioreactors, the energy consumed for transport of water and CO2 turns out to be a small percentage of the energy contained in the algae biomass (0.1-3.6%). For raceway ponds the share for transport is higher (0.7-38.5%). The energy consumption for transport is the lowest in the Benelux due to good availability of both water and CO2. Analysing transport logistics is still important, despite the low energy consumption for transport. The results demonstrate that resource requirements, resource distribution and availability and transport networks have a profound effect on the location choices for algae cultivation. PMID:25549905

  18. Algae fuel clean electricity generation

    SciTech Connect

    O'Sullivan, D.

    1993-02-08

    The paper describes plans for a 600-kW pilot generating unit, fueled by diesel and Chlorella, a green alga commonly seen growing on the surface of ponds. The plant contains Biocoil units in which Chlorella are grown using the liquid effluents from sewage treatment plants and dissolved carbon dioxide from exhaust gases from the combustion unit. The algae are partially dried and fed into the combustor where diesel fuel is used to maintain ignition. Diesel fuel is also used for start-up and as a backup fuel for seasonal shifts that affect the algae growing conditions. Since the algae use the carbon dioxide emitted during the combustion process, the process will not contribute to global warming.

  19. MONOTERPENE BIOSYNTHESIS IN MARINE ALGAE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Marine algae produce a variety of secondary metabolites involved in chemical defense. Among these the monoterpenes present several highly unusual characteristics relative to their terrestrial counterparts. The monoterpenes produced by these marine organisms are nearly always halogenated and posses...

  20. Neuroprotective Effects of Marine Algae

    PubMed Central

    Pangestuti, Ratih; Kim, Se-Kwon

    2011-01-01

    The marine environment is known as a rich source of chemical structures with numerous beneficial health effects. Among marine organisms, marine algae have been identified as an under-exploited plant resource, although they have long been recognized as valuable sources of structurally diverse bioactive compounds. Presently, several lines of studies have provided insight into biological activities and neuroprotective effects of marine algae including antioxidant, anti-neuroinflammatory, cholinesterase inhibitory activity and the inhibition of neuronal death. Hence, marine algae have great potential to be used for neuroprotection as part of pharmaceuticals, nutraceuticals and functional foods. This contribution presents an overview of marine algal neuroprotective effects and their potential application in neuroprotection. PMID:21673890

  1. Microscopic Gardens: A Close Look at Algae.

    ERIC Educational Resources Information Center

    Foote, Mary Ann

    1983-01-01

    Describes classroom activities using algae, including demonstration of eutrophication, examination of mating strains, and activities with Euglena. Includes on algal morphology/physiology, types of algae, and field sources for collecting these organisms. (JN)

  2. Formation of algae growth constitutive relations for improved algae modeling.

    SciTech Connect

    Gharagozloo, Patricia E.; Drewry, Jessica L.

    2013-01-01

    This SAND report summarizes research conducted as a part of a two year Laboratory Directed Research and Development (LDRD) project to improve our abilities to model algal cultivation. Algae-based biofuels have generated much excitement due to their potentially large oil yield from relatively small land use and without interfering with the food or water supply. Algae mitigate atmospheric CO2 through metabolism. Efficient production of algal biofuels could reduce dependence on foreign oil by providing a domestic renewable energy source. Important factors controlling algal productivity include temperature, nutrient concentrations, salinity, pH, and the light-to-biomass conversion rate. Computational models allow for inexpensive predictions of algae growth kinetics in these non-ideal conditions for various bioreactor sizes and geometries without the need for multiple expensive measurement setups. However, these models need to be calibrated for each algal strain. In this work, we conduct a parametric study of key marine algae strains and apply the findings to a computational model.

  3. 21 CFR 184.1121 - Red algae.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Red algae. 184.1121 Section 184.1121 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1121 Red algae. (a) Red algae are seaweeds of the species...

  4. 21 CFR 184.1121 - Red algae.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Red algae. 184.1121 Section 184.1121 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1121 Red algae. (a) Red algae are seaweeds of the species...

  5. 21 CFR 184.1121 - Red algae.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Red algae. 184.1121 Section 184.1121 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1121 Red algae. (a) Red algae are seaweeds of the species...

  6. 21 CFR 184.1121 - Red algae.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Red algae. 184.1121 Section 184.1121 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1121 Red algae. (a) Red algae are seaweeds of the species...

  7. 21 CFR 184.1120 - Brown algae.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Brown algae. 184.1120 Section 184.1120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1120 Brown algae. (a) Brown algae are seaweeds of the species...

  8. 21 CFR 184.1120 - Brown algae.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Brown algae. 184.1120 Section 184.1120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT FOOD....1120 Brown algae. (a) Brown algae are seaweeds of the species Analipus japonicus, Eisenia...

  9. 21 CFR 184.1120 - Brown algae.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Brown algae. 184.1120 Section 184.1120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1120 Brown algae. (a) Brown algae are seaweeds of the species...

  10. 21 CFR 184.1121 - Red algae.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Red algae. 184.1121 Section 184.1121 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT FOOD....1121 Red algae. (a) Red algae are seaweeds of the species Gloiopeltis furcata, Porphyra...

  11. 21 CFR 184.1120 - Brown algae.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Brown algae. 184.1120 Section 184.1120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1120 Brown algae. (a) Brown algae are seaweeds of the species...

  12. 21 CFR 184.1120 - Brown algae.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Brown algae. 184.1120 Section 184.1120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1120 Brown algae. (a) Brown algae are seaweeds of the species...

  13. Algae. LC Science Tracer Bullet.

    ERIC Educational Resources Information Center

    Niskern, Diana, Comp.

    The plants and plantlike organisms informally grouped together as algae show great diversity of form and size and occur in a wide variety of habitats. These extremely important photosynthesizers are also economically significant. For example, some species contaminate water supplies; others provide food for aquatic animals and for man; still others…

  14. Biological importance of marine algae

    PubMed Central

    El Gamal, Ali A.

    2009-01-01

    Marine organisms are potentially prolific sources of highly bioactive secondary metabolites that might represent useful leads in the development of new pharmaceutical agents. Algae can be classified into two main groups; first one is the microalgae, which includes blue green algae, dinoflagellates, bacillariophyta (diatoms)… etc., and second one is macroalgae (seaweeds) which includes green, brown and red algae. The microalgae phyla have been recognized to provide chemical and pharmacological novelty and diversity. Moreover, microalgae are considered as the actual producers of some highly bioactive compounds found in marine resources. Red algae are considered as the most important source of many biologically active metabolites in comparison to other algal classes. Seaweeds are used for great number of application by man. The principal use of seaweeds as a source of human food and as a source of gums (phycocollides). Phycocolloides like agar agar, alginic acid and carrageenan are primarily constituents of brown and red algal cell walls and are widely used in industry. PMID:23960716

  15. Algae -- a poor man's HAART?

    PubMed

    Teas, Jane; Hebert, James R; Fitton, J Helen; Zimba, Paul V

    2004-01-01

    Drawing inferences from epidemiologic studies of HIV/AIDS and in vivo and in vitro HIV inhibition by algae, we propose algal consumption as one unifying characteristic of countries with anomalously low rates. HIV/AIDS incidence and prevalence in Eastern Asia ( approximately 1/10000 adults in Japan and Korea), compared to Africa ( approximately 1/10 adults), strongly suggest that differences in IV drug use and sexual behavior are insufficient to explain the 1000-fold variation. Even in Africa, AIDS/HIV rates vary. Chad has consistently reported low rates of HIV/AIDS (2-4/100). Possibly not coincidentally, most people in Japan and Korea eat seaweed daily and the Kanemba, one of the major tribal groups in Chad, eat a blue green alga (Spirulina) daily. Average daily algae consumption in Asia and Africa ranges between 1 and 2 tablespoons (3-13 g). Regular consumption of dietary algae might help prevent HIV infection and suppress viral load among those infected. PMID:15050097

  16. Algae control for hydrogeneration canals

    SciTech Connect

    Grahovac, P.

    1997-02-16

    The purpose of this Cooperative Research and Development Agreement (CRADA) was to assess and develop control practices for nuisance algae growth in power canal that delivers water to hydro-generation facilities. This growth results in expenditures related not only to lost generation but also labor and materials costs associated with implementing remediation procedures. On an industry-wide basis these costs associated with nuisance algal growth are estimated to be several million dollars per year.

  17. Parasites in algae mass culture

    PubMed Central

    Carney, Laura T.; Lane, Todd W.

    2014-01-01

    Parasites are now known to be ubiquitous across biological systems and can play an important role in modulating algal populations. However, there is a lack of extensive information on their role in artificial ecosystems such as algal production ponds and photobioreactors. Parasites have been implicated in the demise of algal blooms. Because individual mass culture systems often tend to be unialgal and a select few algal species are in wide scale application, there is an increased potential for parasites to have a devastating effect on commercial scale monoculture. As commercial algal production continues to expand with a widening variety of applications, including biofuel, food and pharmaceuticals, the parasites associated with algae will become of greater interest and potential economic impact. A number of important algal parasites have been identified in algal mass culture systems in the last few years and this number is sure to grow as the number of commercial algae ventures increases. Here, we review the research that has identified and characterized parasites infecting mass cultivated algae, the techniques being proposed and or developed to control them, and the potential impact of parasites on the future of the algal biomass industry. PMID:24936200

  18. Bioaccumulation of nickel by algae

    SciTech Connect

    Wang, H.K.; Wood, J.M.

    1984-02-01

    Six strains of algae and one Euglena sp. were tested for their ability to bioaccumulate nickel. Radioactive /sup 63/Ni was used together with a microplate technique to determine the conditions for nickel removal by axenic cultures of cyanobacteria, green algae, and one euglenoid. The cyanobacteria tested were found to be more sensitive to nickel toxicity than the green algae or the Euglena sp. The concentration factor (CF) for nickel was determined under a variety of conditions and found to be in the range from 0 to 3.0 x 10/sup 3/. The effect of environmental variables on nickel uptake was examined, and a striking pH effect for biaccumulation was observed, with most of the algal strains accumulating nickel optimally at approximately pH 8.0. Competition experiments for binding sites between nickel and other cations as well as with other complexing anions, showed that /sup 63/Ni uptake was affected only by cobalt and by humic acids.

  19. Stochastic Forecasting of Algae Blooms in Lakes

    SciTech Connect

    Wang, Peng; Tartakovsky, Daniel M.; Tartakovsky, Alexandre M.

    2013-01-15

    We consider the development of harmful algae blooms (HABs) in a lake with uncertain nutrients inflow. Two general frameworks, Fokker-Planck equation and the PDF methods, are developed to quantify the resultant concentration uncertainty of various algae groups, via deriving a deterministic equation of their joint probability density function (PDF). A computational example is examined to study the evolution of cyanobacteria (the blue-green algae) and the impacts of initial concentration and inflow-outflow ratio.

  20. Biotransformation of benzo[a]pyrene and other polycyclic aromatic hydrocarbons and heterocyclic analogs by several green algae and other algal species under gold and white light.

    PubMed

    Warshawsky, D; Cody, T; Radike, M; Reilman, R; Schumann, B; LaDow, K; Schneider, J

    1995-07-14

    This laboratory has shown that the metabolism of benzo[a]pyrene (BaP), a carcinogenic polycyclic aromatic hydrocarbon (PAH), by a freshwater green alga, Selenastrum capricornutum, under gold light proceeds through a dioxygenase pathway with subsequent conjugation and excretion. This study was undertaken to determine: (1) the effects of different light sources on the enzymatic or photochemical processes involved in the biotransformation of BaP over a dose range of 5-1200 mg/l; (2) the phototoxicity of carcinogenic PAHs and mutagenic quinones to a green alga; (3) the ability of other algal systems to metabolize BaP. Cultures were exposed to different doses of BaP for 2 days at 23 degrees C under gold, white or UV-A fluorescent light on a diurnal cycle of 16 h light, 8 h dark. Under gold light, metabolites of BaP produced by Selenastrum capricornutum were the dihydrodiols of which the 11,12-dihydrodiol was the major metabolite. Under white light, at low doses, the major metabolite was the 9,10-dihydrodiol. With increasing dose, the ratio of dihydrodiols to quinones decreased to less than two. With increasing light energy output, from gold to white to UV-A in the PAH absorbing region, BaP quinone production increased. Of other carcinogenic PAHs studied, only 7H-dibenz[c,g]carbazole was as phototoxic as BaP while 7,12-dimethylbenz[a]anthracene, dibenz[a,j]acridine and non-carcinogenic PAHs, anthracene and pyrene, were not phototoxic. The 3,6-quinone of BaP was found to be highly phototoxic while quinones that included menadione, danthron, phenanthrene-quinone and hydroquinone were not. The data suggest that the phototoxicity of BaP is due to photochemical production of quinones; the 3,6-quinone of BaP is phototoxic and is probably the result of the production of short lived cyclic reactive intermediates by the interaction of light with the quinone. Lastly, only the green algae, Selenastrum capricornutum, Scenedesmus acutus and Ankistrodesmus braunii almost completely metabolized BaP to dihydrodiols. The green alga Chlamydomonas reinhardtii, the yellow alga Ochromonas malhamensis, the blue green algae Anabaena flosaquae and euglenoid Euglena gracilis did not metabolize BaP to any extent. The data indicate that algae are important in their ability to degrade PAHs but the degradation is dependent on the dose of light energy emitted and absorbed, the dose of PAHs to which the algae are exposed, the phototoxicity of PAHs and their metabolite(s) and the species and strain of algae involved. All of these factors will be important in assessing the degradation and detoxification pathways of recalcitrant PAHs by algae. PMID:7606812

  1. Effect of Dead Algae on Soil Permeability

    SciTech Connect

    Harvey, R.S.

    2003-02-21

    Since existing basins support heavy growths of unicellular green algae which may be killed by temperature variation or by inadvertent pH changes in waste and then deposited on the basin floor, information on the effects of dead algae on soil permeability was needed. This study was designed to show the effects of successive algal kills on the permeability of laboratory soil columns.

  2. Nutritional And Taste Characteristics Of Algae

    NASA Technical Reports Server (NTRS)

    Karel, M.; Nakhost, Z.

    1992-01-01

    Report describes investigation of chemical composition of blue-green algae Synechococcus 6311, as well as preparation of protein isolate from green alga Scenedesmus obliquus and incorporation into variety of food products evaluated for taste. Part of program to investigate growth of microalgae aboard spacecraft for use as food.

  3. Take a Dip! Culturing Algae Is Easy.

    ERIC Educational Resources Information Center

    James, Daniel E.

    1983-01-01

    Describes laboratory activities using algae as the organisms of choice. These include examination of typical algal cells, demonstration of alternation of generations, sexual reproduction in Oedogonium, demonstration of phototaxis, effect of nitrate concentration on Ankistrodesmus, and study of competition between two algae in the same environment.…

  4. SSMILes: Measuring the Nutrient Tolerance of Algae.

    ERIC Educational Resources Information Center

    Hedgepeth, David J.

    1995-01-01

    Presents an activity integrating mathematics and science intended to introduce students to the use of metric measurement of mass as a way to increase the meaningfulness of observations about variables in life sciences. Involves measuring the nutrient tolerance of algae. Contains a reproducible algae nutrient graph. (Author/MKR)

  5. Take a Dip! Culturing Algae Is Easy.

    ERIC Educational Resources Information Center

    James, Daniel E.

    1983-01-01

    Describes laboratory activities using algae as the organisms of choice. These include examination of typical algal cells, demonstration of alternation of generations, sexual reproduction in Oedogonium, demonstration of phototaxis, effect of nitrate concentration on Ankistrodesmus, and study of competition between two algae in the same environment.

  6. Seastars on Algae Covered Cobbles and Boulders

    USGS Multimedia Gallery

    Digital still photograph from Massachusetts Bay near Cohasset, MA, showing seastars (Asterias sp.), blood stars (Henricia sanguinolenta), blood drop tunicates (Dendrodoa carnea), mussels, and barnacles on cobbles and boulders covered with bubblegum algae and red filamentous algae.  Water d...

  7. Flocculation of model algae under shear.

    SciTech Connect

    Pierce, Flint; Lechman, Jeremy B.

    2010-11-01

    We present results of molecular dynamics simulations of the flocculation of model algae particles under shear. We study the evolution of the cluster size distribution as well as the steady-state distribution as a function of shear rates and algae interaction parameters. Algal interactions are modeled through a DLVO-type potential, a combination of a HS colloid potential (Everaers) and a yukawa/colloid electrostatic potential. The effect of hydrodynamic interactions on aggregation is explored. Cluster strucuture is determined from the algae-algae radial distribution function as well as the structure factor. DLVO parameters including size, salt concentration, surface potential, initial volume fraction, etc. are varied to model different species of algae under a variety of environmental conditions.

  8. Antarctic sea ice thickness affects algae populations

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2013-01-01

    In the waters off Antarctica, algae grow and live in the sea ice that surrounds the southern continent—a floating habitat sure to change as the planet warms. As with most aquatic ecosystems, microscopic algae form the base of the Southern Ocean food web. Distinct algae populations reside in the sea ice surface layers, on the ice's underside, and within the floating ice itself. The algae that reside on the floating ice's underside are particularly important for the region's krill population, while those on the interior or surface layers are less accessible. Understanding how changing sea ice properties will affect the regional biology, then, depends on understanding how algae populations interact with the ice.

  9. The ice nucleation activity of extremophilic algae.

    PubMed

    Kviderova, Jana; Hajek, Josef; Worland, Roger M

    2013-01-01

    Differences in the level of cold acclimation and cryoprotection estimated as ice nucleation activity in snow algae (Chlamydomonas cf. nivalis and Chloromonas nivalis), lichen symbiotic algae (Trebouxia asymmetrica, Trebouxia erici and Trebouxia glomerata), and a mesophilic strain (Chlamydomonas reinhardti) were evaluated. Ice nucleation activity was measured using the freezing droplet method. Measurements were performed using suspensions of cells of A750 (absorbance at 750 nm) ~ 1, 0.1, 0.01 and 0.001 dilutions for each strain. The algae had lower ice nucleation activity, with the exception of Chloromonas nivalis contaminated by bacteria. The supercooling points of the snow algae were higher than those of lichen photobionts. The supercooling points of both, mesophilic and snow Chlamydomonas strains were similar. The lower freezing temperatures of the lichen algae may reflect either the more extreme and more variable environmental conditions of the original localities or the different cellular structure of the strains examined. PMID:23625082

  10. Extraction of lipids from microalgae using CO2-expanded methanol and liquid CO2.

    PubMed

    Paudel, Ashok; Jessop, Michael J; Stubbins, Spencer H; Champagne, Pascale; Jessop, Philip G

    2015-05-01

    The use of CO2-expanded methanol (cxMeOH) and liquid carbon dioxide (lCO2) is proposed to extract lipids from Botryococcus braunii. When compressed CO2 dissolves in methanol, the solvent expands in volume, decreases in polarity and so increases in its selectivity for biodiesel desirable lipids. Solid phase extraction of the algal extract showed that the cxMeOH extracted 21 mg of biodiesel desirable lipids per mL of organic solvent compared to 3mg/mL using either neat methanol or chloroform/methanol mixture. The non-polar lCO2 showed a high affinity for non-polar lipids. Using lCO2, it is possible to extract up to 10% neutral lipids relative to the mass of dry algae. Unlike extractions using conventional solvents, these new methods require little to no volatile, flammable, or chlorinated organic solvents. PMID:25537138

  11. Streptophyte algae and the origin of embryophytes

    PubMed Central

    Becker, Burkhard; Marin, Birger

    2009-01-01

    Background Land plants (embryophytes) evolved from streptophyte green algae, a small group of freshwater algae ranging from scaly, unicellular flagellates (Mesostigma) to complex, filamentous thalli with branching, cell differentiation and apical growth (Charales). Streptophyte algae and embryophytes form the division Streptophyta, whereas the remaining green algae are classified as Chlorophyta. The Charales (stoneworts) are often considered to be sister to land plants, suggesting progressive evolution towards cellular complexity within streptophyte green algae. Many cellular (e.g. phragmoplast, plasmodesmata, hexameric cellulose synthase, structure of flagellated cells, oogamous sexual reproduction with zygote retention) and physiological characters (e.g. type of photorespiration, phytochrome system) originated within streptophyte algae. Recent Progress Phylogenetic studies have demonstrated that Mesostigma (flagellate) and Chlorokybus (sarcinoid) form the earliest divergence within streptophytes, as sister to all other Streptophyta including embryophytes. The question whether Charales, Coleochaetales or Zygnematales are the sister to embryophytes is still (or, again) hotly debated. Projects to study genome evolution within streptophytes including protein families and polyadenylation signals have been initiated. In agreement with morphological and physiological features, many molecular traits believed to be specific for embryophytes have been shown to predate the Chlorophyta/Streptophyta split, or to have originated within streptophyte algae. Molecular phylogenies and the fossil record allow a detailed reconstruction of the early evolutionary events that led to the origin of true land plants, and shaped the current diversity and ecology of streptophyte green algae and their embryophyte descendants. Conclusions The Streptophyta/Chlorophyta divergence correlates with a remarkably conservative preference for freshwater/marine habitats, and the early freshwater adaptation of streptophyte algae was a major advantage for the earliest land plants, even before the origin of the embryo and the sporophyte generation. The complete genomes of a few key streptophyte algae taxa will be required for a better understanding of the colonization of terrestrial habitats by streptophytes. PMID:19273476

  12. Algae biodiesel - a feasibility report

    PubMed Central

    2012-01-01

    Background Algae biofuels have been studied numerous times including the Aquatic Species program in 1978 in the U.S., smaller laboratory research projects and private programs. Results Using Molina Grima 2003 and Department of Energy figures, captial costs and operating costs of the closed systems and open systems were estimated. Cost per gallon of conservative estimates yielded $1,292.05 and $114.94 for closed and open ponds respectively. Contingency scenarios were generated in which cost per gallon of closed system biofuels would reach $17.54 under the generous conditions of 60% yield, 50% reduction in the capital costs and 50% hexane recovery. Price per gallon of open system produced fuel could reach $1.94 under generous assumptions of 30% yield and $0.2/kg CO2. Conclusions Current subsidies could allow biodiesel to be produced economically under the generous conditions specified by the model. PMID:22540986

  13. Errors When Extracting Oil from Algae

    NASA Astrophysics Data System (ADS)

    Murphy, E.; Treat, R.; Ichiuji, T.

    2014-12-01

    Oil is in popular demand, but the worldwide amount of oil is decreasing and prices for it are steadily increasing. Leading scientists have been working to find a solution of attaining oil in an economically and environmentally friendly way. Researchers at the U.S. Department of Energy's Pacific Northwest National Laboratory (PNNL) have determined that "a small mixture of algae and water can be turned into crude oil in less than an hour" (Sheehan, Duhahay, Benemann, Poessler). There are various ways of growing the algae, such as closed loop and open loop methods, as well as processes of extracting oil, such as hydrothermal liquefaction and the hexane-solvent method. Our objective was to grow the algae (C. reinhardtii) and extract oil from it using NaOH and HCl, because we had easy access to those specific chemicals. After two trials of attempted algae growth, we discovered that a bacteria was killing off the algae. This led us to further contemplation on how this dead algae and bacteria are affecting our environment, and the organisms within it. Eutrophication occurs when excess nutrients stimulate rapid growth of algae in an aquatic environment. This can clog waterways and create algal blooms in blue-green algae, as well as neurotoxic red tide phytoplankton. These microscopic algae die upon consumption of the nutrients in water and are degraded by bacteria. The bacteria respires and creates an acidic environment with the spontaneous conversion of carbon dioxide to carbonic acid in water. This process of degradation is exactly what occurred in our 250 mL flask. When the phytoplankton attacked our algae, it created a hypoxic environment, which eliminated any remaining amounts of oxygen, carbon dioxide, and nutrients in the water, resulting in a miniature dead zone. These dead zones can occur almost anywhere where there are algae and bacteria, such as the ocean, and make it extremely difficult for any organism to survive. This experiment helped us realize the consequences of our actions, and we saw for ourselves how we are polluting and killing the environment. Releasing excess nutrients into our waterways is creating a destructive chain reaction, but if we monitor our output of pollution, we can minimize the amount of damage we do to algae, organisms, and the environment in general.

  14. Life cycle analysis of unicellular algae.

    PubMed

    Gerashchenko, Bogdan I; Takahashi, Toshiyuki; Kosaka, Toshikazu; Hosoya, Hiroshi

    2010-04-01

    Unicellular green alga is a very convenient object for flow cytometric characterization. Flow cytometry has been proposed as a quick and reliable tool for studying life cycle and growth of unicellular algae. Cell size of vegetating algae can be monitored in association with their DNA and endogenous chlorophyll content. Cells of interest (e.g., group of cells of a certain stage of the life cycle) in an asynchronously proliferating cell population can be sorted out for further microscopical or molecular biology studies. This methodological approach can be helpful for researchers who are interested in algal proliferation. PMID:20373493

  15. Method and apparatus for processing algae

    DOEpatents

    Chew, Geoffrey; Reich, Alton J.; Dykes, Jr., H. Waite; Di Salvo, Roberto

    2012-07-03

    Methods and apparatus for processing algae are described in which a hydrophilic ionic liquid is used to lyse algae cells. The lysate separates into at least two layers including a lipid-containing hydrophobic layer and an ionic liquid-containing hydrophilic layer. A salt or salt solution may be used to remove water from the ionic liquid-containing layer before the ionic liquid is reused. The used salt may also be dried and/or concentrated and reused. The method can operate at relatively low lysis, processing, and recycling temperatures, which minimizes the environmental impact of algae processing while providing reusable biofuels and other useful products.

  16. 21 CFR 73.275 - Dried algae meal.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Dried algae meal. 73.275 Section 73.275 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.275 Dried algae meal. (a) Identity. The color additive dried algae meal is a dried mixture of algae cells (genus Spongiococcum, separated from its culture...

  17. 21 CFR 73.275 - Dried algae meal.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Dried algae meal. 73.275 Section 73.275 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.275 Dried algae meal. (a) Identity. The color additive dried algae meal is a dried mixture of algae cells (genus Spongiococcum, separated from its culture...

  18. 21 CFR 73.275 - Dried algae meal.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Dried algae meal. 73.275 Section 73.275 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.275 Dried algae meal. (a) Identity. The color additive dried algae meal is a dried mixture of algae cells (genus Spongiococcum, separated from its culture...

  19. 21 CFR 73.275 - Dried algae meal.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Dried algae meal. 73.275 Section 73.275 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.275 Dried algae meal. (a) Identity. The color additive dried algae meal is a dried mixture of algae cells (genus Spongiococcum, separated from its culture...

  20. Collection, Isolation and Culture of Marine Algae.

    ERIC Educational Resources Information Center

    James, Daniel E.

    1984-01-01

    Methods of collecting, isolating, and culturing microscopic and macroscopic marine algae are described. Three different culture media list of chemicals needed and procedures for preparing Erdschreiber's and Provasoli's E. S. media. (BC)

  1. 2011 Biomass Program Platform Peer Review: Algae

    SciTech Connect

    Yang, Joyce

    2012-02-01

    This document summarizes the recommendations and evaluations provided by an independent external panel of experts at the 2011 U.S. Department of Energy Biomass Program’s Algae Platform Review meeting.

  2. Stochastic Forecasting of Algae Blooms in Lakes

    SciTech Connect

    Wang, Peng; Tartakovsky, Daniel M.; Tartakovsky, Alexandre M.

    2013-01-03

    We consider a general framework to predict the development of harmful algal blooms (HABs) in a lake driven by uncertain parameters. To quantify the concentration uncertainty of those algae groups via their joint probabilistic density function (PDF), we explore an approach based on the Fokker-Planck equation. Our result is presented in an example where abundant nutrients contribute to the proliferation of cyanobacteria and other minor algae groups.

  3. Antioxidant activity of Hawaiian marine algae.

    PubMed

    Kelman, Dovi; Posner, Ellen Kromkowski; McDermid, Karla J; Tabandera, Nicole K; Wright, Patrick R; Wright, Anthony D

    2012-02-01

    Marine algae are known to contain a wide variety of bioactive compounds, many of which have commercial applications in pharmaceutical, medical, cosmetic, nutraceutical, food and agricultural industries. Natural antioxidants, found in many algae, are important bioactive compounds that play an important role against various diseases and ageing processes through protection of cells from oxidative damage. In this respect, relatively little is known about the bioactivity of Hawaiian algae that could be a potential natural source of such antioxidants. The total antioxidant activity of organic extracts of 37 algal samples, comprising of 30 species of Hawaiian algae from 27 different genera was determined. The activity was determined by employing the FRAP (Ferric Reducing Antioxidant Power) assays. Of the algae tested, the extract of Turbinaria ornata was found to be the most active. Bioassay-guided fractionation of this extract led to the isolation of a variety of different carotenoids as the active principles. The major bioactive antioxidant compound was identified as the carotenoid fucoxanthin. These results show, for the first time, that numerous Hawaiian algae exhibit significant antioxidant activity, a property that could lead to their application in one of many useful healthcare or related products as well as in chemoprevention of a variety of diseases including cancer. PMID:22412808

  4. Carotenoids in algae: distributions, biosyntheses and functions.

    PubMed

    Takaichi, Shinichi

    2011-01-01

    For photosynthesis, phototrophic organisms necessarily synthesize not only chlorophylls but also carotenoids. Many kinds of carotenoids are found in algae and, recently, taxonomic studies of algae have been developed. In this review, the relationship between the distribution of carotenoids and the phylogeny of oxygenic phototrophs in sea and fresh water, including cyanobacteria, red algae, brown algae and green algae, is summarized. These phototrophs contain division- or class-specific carotenoids, such as fucoxanthin, peridinin and siphonaxanthin. The distribution of ?-carotene and its derivatives, such as lutein, loroxanthin and siphonaxanthin, are limited to divisions of Rhodophyta (macrophytic type), Cryptophyta, Euglenophyta, Chlorarachniophyta and Chlorophyta. In addition, carotenogenesis pathways are discussed based on the chemical structures of carotenoids and known characteristics of carotenogenesis enzymes in other organisms; genes and enzymes for carotenogenesis in algae are not yet known. Most carotenoids bind to membrane-bound pigment-protein complexes, such as reaction center, light-harvesting and cytochrome b(6)f complexes. Water-soluble peridinin-chlorophyll a-protein (PCP) and orange carotenoid protein (OCP) are also established. Some functions of carotenoids in photosynthesis are also briefly summarized. PMID:21747749

  5. PPR proteins of green algae.

    PubMed

    Tourasse, Nicolas J; Choquet, Yves; Vallon, Olivier

    2013-01-01

    Using the repeat finding algorithm FT-Rep, we have identified 154 pentatricopeptide repeat (PPR) proteins in nine fully sequenced genomes from green algae (with a total of 1201 repeats) and grouped them in 47 orthologous groups. All data are available in a database, PPRdb, accessible online at http://giavap-genomes.ibpc.fr/ppr. Based on phylogenetic trees generated from the repeats, we propose evolutionary scenarios for PPR proteins. Two PPRs are clearly conserved in the entire green lineage: MRL1 is a stabilization factor for the rbcL mRNA, while HCF152 binds in plants to the psbH-petB intergenic region. MCA1 (the stabilization factor for petA) and PPR7 (a short PPR also acting on chloroplast mRNAs) are conserved across the entire Chlorophyta. The other PPRs are clade-specific, with evidence for gene losses, duplications, and horizontal transfer. In some PPR proteins, an additional domain found at the C terminus provides clues as to possible functions. PPR19 and PPR26 possess a methyltransferase_4 domain suggesting involvement in RNA guanosine methylation. PPR18 contains a C-terminal CBS domain, similar to the CBSPPR1 protein found in nucleoids. PPR16, PPR29, PPR37, and PPR38 harbor a SmR (MutS-related) domain similar to that found in land plants pTAC2, GUN1, and SVR7. The PPR-cyclins PPR3, PPR4, and PPR6, in addition, contain a cyclin domain C-terminal to their SmR domain. PPR31 is an unusual PPR-cyclin containing at its N terminus an OctotricoPeptide Repeat (OPR) and a RAP domain. We consider the possibility that PPR proteins with a SmR domain can introduce single-stranded nicks in the plastid chromosome. PMID:24021981

  6. Estimation of alga growth stage and lipid content growth rate

    NASA Technical Reports Server (NTRS)

    Embaye, Tsegereda N. (Inventor); Trent, Jonathan D. (Inventor)

    2012-01-01

    Method and system for estimating a growth stage of an alga in an ambient fluid. Measured light beam absorption or reflection values through or from the alga and through an ambient fluid, in each of two or more wavelength sub-ranges, are compared with reference light beam absorption values for corresponding wavelength sub-ranges for in each alga growth stage to determine (1) which alga growth stage, if any, is more likely and (2) whether estimated lipid content of the alga is increasing or has peaked. Alga growth is preferably terminated when lipid content has approximately reached a maximum value.

  7. Oil from algae; salvation from peak oil?

    PubMed

    Rhodes, Christopher J

    2009-01-01

    A review is presented of the use of algae principally to produce biodiesel fuel, as a replacement for conventional fuel derived from petroleum. The imperative for such a strategy is that cheap supplies of crude oil will begin to wane within a decade and land-based crops cannot provide more than a small amount of the fuel the world currently uses, even if food production were allowed to be severely compromised. For comparison, if one tonne of biodiesel might be produced say, from rape-seed per hectare, that same area of land might ideally yield 100 tonnes of biodiesel grown from algae. Placed into perspective, the entire world annual petroleum demand which is now provided for by 31 billion barrels of crude oil might instead be met from algae grown on an area equivalent to 4% of that of the United States. As an additional benefit, in contrast to growing crops it is not necessary to use arable land, since pond-systems might be placed anywhere, even in deserts, and since algae grow well on saline water or wastewaters, no additional burden is imposed on freshwater-a significant advantage, as water shortages threaten. Algae offer the further promise that they might provide future food supplies, beyond what can be offered by land-based agriculture to a rising global population. PMID:19544699

  8. Turning Algae into Energy in New Mexico

    SciTech Connect

    Sayre, Richard; Olivares, Jose; Lammers, Peter

    2013-07-29

    Los Alamos National Laboratory, as part of the New Mexico Consortium - comprised of New Mexico's major research universities, the Lab, and key industry partners - is conducting research into using algae as a feed stock for a renewable source of fuels, and other products. There are hundreds of thousands of different algae species on Earth. They account for approximately half of the net photosynthesis on the planet, yet they have not been used in any kind of a large scale by humanity, with just a few exceptions. And yet, the biomass is easy to transform into useful products, including fuels, and they contain many other natural products that have high value. In this video Los Alamos and New Mexico State University scientists outline the opportunities and challenges of using science to turn algae into energy.

  9. Turning Algae into Energy in New Mexico

    ScienceCinema

    Sayre, Richard; Olivares, Jose; Lammers, Peter

    2014-06-24

    Los Alamos National Laboratory, as part of the New Mexico Consortium - comprised of New Mexico's major research universities, the Lab, and key industry partners - is conducting research into using algae as a feed stock for a renewable source of fuels, and other products. There are hundreds of thousands of different algae species on Earth. They account for approximately half of the net photosynthesis on the planet, yet they have not been used in any kind of a large scale by humanity, with just a few exceptions. And yet, the biomass is easy to transform into useful products, including fuels, and they contain many other natural products that have high value. In this video Los Alamos and New Mexico State University scientists outline the opportunities and challenges of using science to turn algae into energy.

  10. Algae control problems and practices workshop

    SciTech Connect

    Pryfogle, P.A.; Ghio, G.

    1996-09-01

    Western water resources are continuously facing increased demand from industry and the public. Consequently, many of these resources are required to perform multiple tasks as they cycle through the ecosystem. Many plants and animals depend upon these resources for growth. Algae are one group of plants associated with nutrient and energy cycles in many aquatic ecosystems. Although most freshwater algae are microscopic in size, they are capable of dominating and proliferating to the extent that the value of the water resource for both industrial and domestic needs is compromised. There is a great diversity of aquatic environments and systems in which algae may be found, and there are many varieties of treatment and control techniques available to reduce the impacts of excessive growth. This workshop was organized to exchange information about these control problems and practices.

  11. Genome of the red alga Porphyridium purpureum.

    PubMed

    Bhattacharya, Debashish; Price, Dana C; Chan, Cheong Xin; Qiu, Huan; Rose, Nicholas; Ball, Steven; Weber, Andreas P M; Arias, Maria Cecilia; Henrissat, Bernard; Coutinho, Pedro M; Krishnan, Anagha; Zuner, Simone; Morath, Shannon; Hilliou, Frdrique; Egizi, Andrea; Perrineau, Marie-Mathilde; Yoon, Hwan Su

    2013-01-01

    The limited knowledge we have about red algal genomes comes from the highly specialized extremophiles, Cyanidiophyceae. Here, we describe the first genome sequence from a mesophilic, unicellular red alga, Porphyridium purpureum. The 8,355 predicted genes in P. purpureum, hundreds of which are likely to be implicated in a history of horizontal gene transfer, reside in a genome of 19.7 Mbp with 235 spliceosomal introns. Analysis of light-harvesting complex proteins reveals a nuclear-encoded phycobiliprotein in the alga. We uncover a complex set of carbohydrate-active enzymes, identify the genes required for the methylerythritol phosphate pathway of isoprenoid biosynthesis, and find evidence of sexual reproduction. Analysis of the compact, function-rich genome of P. purpureum suggests that ancestral lineages of red algae acted as mediators of horizontal gene transfer between prokaryotes and photosynthetic eukaryotes, thereby significantly enriching genomes across the tree of photosynthetic life. PMID:23770768

  12. Genome of the red alga Porphyridium purpureum

    PubMed Central

    Bhattacharya, Debashish; Price, Dana C.; Xin Chan, Cheong; Qiu, Huan; Rose, Nicholas; Ball, Steven; Weber, Andreas P. M.; Cecilia Arias, Maria; Henrissat, Bernard; Coutinho, Pedro M.; Krishnan, Anagha; Zäuner, Simone; Morath, Shannon; Hilliou, Frédérique; Egizi, Andrea; Perrineau, Marie-Mathilde; Yoon, Hwan Su

    2013-01-01

    The limited knowledge we have about red algal genomes comes from the highly specialized extremophiles, Cyanidiophyceae. Here, we describe the first genome sequence from a mesophilic, unicellular red alga, Porphyridium purpureum. The 8,355 predicted genes in P. purpureum, hundreds of which are likely to be implicated in a history of horizontal gene transfer, reside in a genome of 19.7 Mbp with 235 spliceosomal introns. Analysis of light-harvesting complex proteins reveals a nuclear-encoded phycobiliprotein in the alga. We uncover a complex set of carbohydrate-active enzymes, identify the genes required for the methylerythritol phosphate pathway of isoprenoid biosynthesis, and find evidence of sexual reproduction. Analysis of the compact, function-rich genome of P. purpureum suggests that ancestral lineages of red algae acted as mediators of horizontal gene transfer between prokaryotes and photosynthetic eukaryotes, thereby significantly enriching genomes across the tree of photosynthetic life. PMID:23770768

  13. Study of metal bioaccumulation by nuclear microprobe analysis of algae fossils and living algae cells

    NASA Astrophysics Data System (ADS)

    Guo, P.; Wang, J.; Li, X.; Zhu, J.; Reinert, T.; Heitmann, J.; Spemann, D.; Vogt, J.; Flagmeyer, R.-H.; Butz, T.

    2000-03-01

    Microscopic ion-beam analysis of palaeo-algae fossils and living green algae cells have been performed to study the metal bioaccumulation processes. The algae fossils, both single cellular and multicellular, are from the late Neoproterozonic (570 million years ago) ocean and perfectly preserved within a phosphorite formation. The biosorption of the rare earth element ions Nd 3+ by the green algae species euglena gracilis was investigated with a comparison between the normal cells and immobilized ones. The new Leipzig Nanoprobe, LIPSION, was used to produce a proton beam with 2 μm size and 0.5 nA beam current for this study. PIXE and RBS techniques were used for analysis and imaging. The observation of small metal rich spores ( <10 μm) surrounding both of the fossils and the living cells proved the existence of some specific receptor sites which bind metal carrier ligands at the microbic surface. The bioaccumulation efficiency of neodymium by the algae cells was 10 times higher for immobilized algae cells. It confirms the fact that the algae immobilization is an useful technique to improve its metal bioaccumulation.

  14. An Overview of Algae Biofuel Production and Potential Environmental Impact

    EPA Science Inventory

    Algae are among the most potentially significant sources of sustainable biofuels in the future of renewable energy. A feedstock with virtually unlimited applicability, algae can metabolize various waste streams (e.g., municipal wastewater, carbon dioxide from industrial flue gas)...

  15. ALGAE BLOOMS AND PHOSPHORUS LOADING IN LAKE LOWELL, IDAHO

    EPA Science Inventory

    Algae blooms limit recreational use of Lake Lowell, ID (17050114) by reducing water clarity and esthetic qualities. Under bloom conditions, algae have a negative impact on the reservoir fishery because of periodic oxygen depletion associated with respiration and decomposition. ...

  16. WASP7 BENTHIC ALGAE - MODEL THEORY AND USER'S GUIDE

    EPA Science Inventory

    The standard WASP7 eutrophication module includes nitrogen and phosphorus cycling, dissolved oxygen-organic matter interactions, and phytoplankton kinetics. In many shallow streams and rivers, however, the attached algae (benthic algae, or periphyton, attached to submerged substr...

  17. Use of Brown Algae to Demonstrate Natural Products Techniques.

    ERIC Educational Resources Information Center

    Porter, Lee A.

    1985-01-01

    Background information is provided on the natural products found in marine organisms in general and the brown algae in particular. Also provided are the procedures needed to isolate D-mannitol (a primary metabolite) and cholesterol from brown algae. (JN)

  18. [Accumulation of polycyclic arenes in Baltic Sea algae].

    PubMed

    Veldre, I A; Itra, A R; Paal'me, L P; Kukk, Kh A

    1985-01-01

    The paper presents data on the level of benzo(a)pyrene (BP) and some other polycyclic arenes in alga and phanerogam specimens from different gulfs of the Baltic Sea. Algae were shown to absorb BP from sea water. The mean concentration of BP in sea water was under 0.004 microgram/1, while in algae it ranged 0.1-21.2 micrograms/kg dry weight. Algae accumulate BP to a higher degree than phanerogams. The highest concentrations of BP were found in algae Enteromorpha while the lowest ones in Furcellaria. In annual green algae, BP level was higher in autumn, i. e. at the end of vegetation period, than in spring. Brown algae Fucus vesiculosus is recommended for monitoring polycyclic arene pollution in the area from Vormsi Island to Käsmu and green algae Cladophora or Enteromorpha in the eastern part of the Finnish Gulf. PMID:4060672

  19. Engineering of the growth environment of microalgae with high biomass and lipid productivity.

    PubMed

    Huang, Yu-Tzu; Lee, Huei-Teng; Lai, Chung-Wei

    2013-03-01

    Pure cultures of Botryococcus sp. microalgae have great potential for generating huge amounts of algae lipid that can be further converted into biodiesel. Lipids with nanometer in size can be applied to medicine and pharmacy recently. In this study, the effects of light intensity and CO2 concentration on the biomass productivity, lipid content, and lipid productivity of Botryococcus braunii were examined in 21-day intervals. The optimum cultivating conditions for biomass accumulation were 6,000 lux with 0.04% CO2 and 21 days of culturing; this provided the highest biomass productivity of 140.46 mg L(-1) d(-1). The highest lipid productivity of 44.46 mg L(-1) d(-1) occurred at 6,000 lux with 5% CO2 and 21 days of culturing. The maximum specific growth rate (micro(max)) was similar among different concentrations of CO2 (0.682 d(-1) under 12,000 lux at 10% CO2; 0.585 d(-1) under 6,000 lux at 5% CO2). Culturing at 5% or 10% CO2 has been shown to enhance the accumulation of lipids, introducing the possibility of using flue gas as a carbon source. The nanotechnology in this study will be helpful towards research in green science and engineering such as bio-fixation of CO2 and drug delivery systems. PMID:23755654

  20. How to Identify and Control Water Weeds and Algae.

    ERIC Educational Resources Information Center

    Applied Biochemists, Inc., Mequon, WI.

    Included in this guide to water management are general descriptions of algae, toxic algae, weed problems in lakes, ponds, and canals, and general discussions of mechanical, biological and chemical control methods. In addition, pictures, descriptions, and recommended control methods are given for algae, 6 types of floating weeds, 18 types of

  1. 21 CFR 73.185 - Haematococcus algae meal.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Haematococcus algae meal. 73.185 Section 73.185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.185 Haematococcus algae meal. (a) Identity. (1) The color additive haematococcus algae...

  2. 21 CFR 73.185 - Haematococcus algae meal.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Haematococcus algae meal. 73.185 Section 73.185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.185 Haematococcus algae meal. (a) Identity. (1) The color additive haematococcus algae...

  3. How to Identify and Control Water Weeds and Algae.

    ERIC Educational Resources Information Center

    Applied Biochemists, Inc., Mequon, WI.

    Included in this guide to water management are general descriptions of algae, toxic algae, weed problems in lakes, ponds, and canals, and general discussions of mechanical, biological and chemical control methods. In addition, pictures, descriptions, and recommended control methods are given for algae, 6 types of floating weeds, 18 types of…

  4. Research and development for algae-based technologies in Korea: a review of algae biofuel production.

    PubMed

    Hong, Ji Won; Jo, Seung-Woo; Yoon, Ho-Sung

    2015-03-01

    This review covers recent research and development (R&D) activities in the field of algae-based biofuels in Korea. As South Korea's energy policy paradigm has focused on the development of green energies, the government has funded several algae biofuel R&D consortia and pilot projects. Three major programs have been launched since 2009, and significant efforts are now being made to ensure a sustainable supply of algae-based biofuels. If these R&D projects are executed as planned for the next 10 years, they will enable us to overcome many technical barriers in algae biofuel technologies and help Korea to become one of the leading countries in green energy by 2020. PMID:24496987

  5. Bromophenols in Marine Algae and Their Bioactivities

    PubMed Central

    Liu, Ming; Hansen, Poul Erik; Lin, Xiukun

    2011-01-01

    Marine algae contain various bromophenols that have been shown to possess a variety of biological activities, including antioxidant, antimicrobial, anticancer, anti-diabetic, and anti-thrombotic effects. Here, we briefly review the recent progress of these marine algal biomaterials, with respect to structure, bioactivities, and their potential application as pharmaceuticals. PMID:21822416

  6. Spirulina: The Alga That Can End Malnutrition.

    ERIC Educational Resources Information Center

    Fox, Ripley D.

    1985-01-01

    One approach to eliminating malnutrition worldwide is to grow spirulina in recycled village wastes. Spirulina is a blue-green alga and a natural concentrated food. Spirulina can give poor villages a nutritional food supplement they can grow themselves and can reduce infectious disease at the same time. (Author/RM)

  7. Pheromone signaling during sexual reproduction in algae.

    PubMed

    Frenkel, Johannes; Vyverman, Wim; Pohnert, Georg

    2014-08-01

    Algae are found in all aquatic and many terrestrial habitats. They are dominant in phytoplankton and biofilms thereby contributing massively to global primary production. Since algae comprise photosynthetic representatives of the various protoctist groups their physiology and appearance is highly diverse. This diversity is also mirrored in their characteristic life cycles that exhibit various facets of ploidy and duration of the asexual phase as well as gamete morphology. Nevertheless, sexual reproduction in unicellular and colonial algae usually has as common motive that two specialized, sexually compatible haploid gametes establish physical contact and fuse. To guarantee mating success, processes during sexual reproduction are highly synchronized and regulated. This review focuses on sex pheromones of algae that play a key role in these processes. Especially, the diversity of sexual strategies as well as of the compounds involved are the focus of this contribution. Discoveries connected to algal pheromone chemistry shed light on the role of key evolutionary processes, including endosymbiotic events and lateral gene transfer, speciation and adaptation at all phylogenetic levels. But progress in this field might also in the future provide valid tools for the manipulation of aquaculture and environmental processes. PMID:24597605

  8. Potential of mass algae production in Kuwait

    SciTech Connect

    Prokop, A.; Fekri, M.

    1984-11-01

    The rationale for efficient light absorption by algae at a production unit is given and design details of an intensive thin-layer technology outdoor (2.11m/sup 2/) unit are presented. Data on productivity under extreme conditions were collected. Maximum productivity data are close to those reported in the literature for similar geographic areas.

  9. Fucoidans sulfated polysaccharides of brown algae

    NASA Astrophysics Data System (ADS)

    Usov, Anatolii I.; Bilan, M. I.

    2009-08-01

    The methods of isolation of fucoidans and determination of their chemical structures are reviewed. The fucoidans represent sulfated polysaccharides of brown algae, the composition of which varies from simple fucan sulfates to complex heteropolysaccharides. The currently known structures of such biopolymers are presented. A variety of the biological activities of fucoidans is briefly summarised.

  10. [Allelopathic effect of artemisinin on green algae].

    PubMed

    Wu, Ye-Kuan; Yuan, Ling; Huang, Jian-Guo; Li, Long-Yun

    2013-05-01

    To study the growth effects of differing concentrations of artemisinin on green algae and to evaluate the ecological risk. The effects of artemisinin on the growth and the content change of chlorophyll, protein, oxygen, conductivity, SOD, CAT, MDA in Chlorella pyrenoidosa and Scenedesmus oblique were studied through 96 h toxicity tests. Artemisinin accelerated the growth of algae at a lower concentration ( <40 microg . L-1) with content increase of chlorophyll or protein and so on, and it inhibited the growth of algae at higher concentration ( >80 microg . L-1). The content of chlorophyll or protein in algae cells reduced with the increasing concentration of artemisinin, exhibiting the good concentration-effect relationship. SOD and CAT activity was stimulated at low concentrations ( <40 microg . L-1 ) and inhibited at high concentrations ( >80 microg . L- 1). However, MDA content increased significantly with the increase of concentration. According to the seven kinds of indicators changes, the time-response and dose-response suggested that the surfactant first hurt in Ch. pyrenoidosa was damaging membrane by changing membrane lipid molecules soluble. And primary mechanism on Chlorophyta cells might be related to the oxidation damage of lipid and other biological large molecules caused by artemisinin. The large-scale intensive planting of Artemisia annua may reduce the surrounding water productivity. PMID:23944067

  11. Laser-fluorescence measurement of marine algae

    NASA Technical Reports Server (NTRS)

    Browell, E. V.

    1980-01-01

    Progress in remote sensing of algae by laser-induced fluorescence is subject of comprehensive report. Existing single-wavelength and four-wavelength systems are reviewed, and new expression for power received by airborne sensor is derived. Result differs by as much as factor of 10 from those previously reported. Detailed error analysis evluates factors affecting accuracy of laser-fluorosensor systems.

  12. OPTIMAL COST CONTROL STRATEGIES FOR ATTACHED ALGAE

    EPA Science Inventory

    This paper presents a cost-benefit analysis for alternative programs intended for the control of the nuisance growth of an attached alga (Cladophora). Such analyses require that changes in water quality be quantitatively related to the cost of implementation for specific manageme...

  13. Engineering Triterpene and Methylated Triterpene Production in Plants Provides Biochemical and Physiological Insights into Terpene Metabolism1[OPEN

    PubMed Central

    Jiang, Zuodong; Kempinski, Chase; Bush, Caroline J.; Nybo, S. Eric; Chappell, Joe

    2016-01-01

    Linear, branch-chained triterpenes, including squalene (C30), botryococcene (C30), and their methylated derivatives (C31–C37), generated by the green alga Botryococcus braunii race B have received significant attention because of their utility as chemical and biofuel feedstocks. However, the slow growth habit of B. braunii makes it impractical as a production system. In this study, we evaluated the potential of generating high levels of botryococcene in tobacco (Nicotiana tabacum) plants by diverting carbon flux from the cytosolic mevalonate pathway or the plastidic methylerythritol phosphate pathway by the targeted overexpression of an avian farnesyl diphosphate synthase along with two versions of botryococcene synthases. Up to 544 µg g−1 fresh weight of botryococcene was achieved when this metabolism was directed to the chloroplasts, which is approximately 90 times greater than that accumulating in plants engineered for cytosolic production. To test if methylated triterpenes could be produced in tobacco, we also engineered triterpene methyltransferases (TMTs) from B. braunii into wild-type plants and transgenic lines selected for high-level triterpene accumulation. Up to 91% of the total triterpene contents could be converted to methylated forms (C31 and C32) by cotargeting the TMTs and triterpene biosynthesis to the chloroplasts, whereas only 4% to 14% of total triterpenes were methylated when this metabolism was directed to the cytoplasm. When the TMTs were overexpressed in the cytoplasm of wild-type plants, up to 72% of the total squalene was methylated, and total triterpene (C30+C31+C32) content was elevated 7-fold. Altogether, these results point to innate mechanisms controlling metabolite fluxes, including a homeostatic role for squalene. PMID:26603654

  14. Engineering Triterpene and Methylated Triterpene Production in Plants Provides Biochemical and Physiological Insights into Terpene Metabolism.

    PubMed

    Jiang, Zuodong; Kempinski, Chase; Bush, Caroline J; Nybo, S Eric; Chappell, Joe

    2016-02-01

    Linear, branch-chained triterpenes, including squalene (C30), botryococcene (C30), and their methylated derivatives (C31-C37), generated by the green alga Botryococcus braunii race B have received significant attention because of their utility as chemical and biofuel feedstocks. However, the slow growth habit of B. braunii makes it impractical as a production system. In this study, we evaluated the potential of generating high levels of botryococcene in tobacco (Nicotiana tabacum) plants by diverting carbon flux from the cytosolic mevalonate pathway or the plastidic methylerythritol phosphate pathway by the targeted overexpression of an avian farnesyl diphosphate synthase along with two versions of botryococcene synthases. Up to 544 g g(-1) fresh weight of botryococcene was achieved when this metabolism was directed to the chloroplasts, which is approximately 90 times greater than that accumulating in plants engineered for cytosolic production. To test if methylated triterpenes could be produced in tobacco, we also engineered triterpene methyltransferases (TMTs) from B. braunii into wild-type plants and transgenic lines selected for high-level triterpene accumulation. Up to 91% of the total triterpene contents could be converted to methylated forms (C31 and C32) by cotargeting the TMTs and triterpene biosynthesis to the chloroplasts, whereas only 4% to 14% of total triterpenes were methylated when this metabolism was directed to the cytoplasm. When the TMTs were overexpressed in the cytoplasm of wild-type plants, up to 72% of the total squalene was methylated, and total triterpene (C30+C31+C32) content was elevated 7-fold. Altogether, these results point to innate mechanisms controlling metabolite fluxes, including a homeostatic role for squalene. PMID:26603654

  15. Uric acid deposits in symbiotic marine algae.

    PubMed

    Clode, Peta L; Saunders, Martin; Maker, Garth; Ludwig, Martha; Atkins, Craig A

    2009-02-01

    The symbiosis between cnidarians and dinoflagellate algae is not understood at the cell or molecular level, yet this relationship is responsible for the formation of thousands of square kilometres of coral reefs. We have investigated the nature of crystalline material prominent within marine algal symbionts of Aiptasia sp. anemones. This material, which has historically been considered to be calcium oxalate, is shown to be uric acid. We demonstrate that these abundant uric acid stores can be mobilized rapidly, thereby allowing the algal symbionts to flourish in an otherwise N-poor environment. This is the first report of uric acid accumulation by symbiotic marine algae. These data provide new insight and considerations for understanding the physiological basis of algal symbioses, and represent a new and previously unconsidered aspect of N metabolism in cnidarian, and a variety of other, marine symbioses. PMID:19021889

  16. Photooxidative death in blue-green algae.

    PubMed

    Abeliovich, A; Shilo, M

    1972-09-01

    When incubated in the light under 100% oxygen, wild-type blue-green algae (Anacystis nidulans, Synechococcus cedrorum) die out rapidly at temperatures of 4 to 15 C, and at 35 C (or at 26 C in the case of S. cedrorum) in the absence of CO(2). Photosynthesis is impaired in these cells long before they die. Blocking of photosystem II at high temperatures in the presence of CO(2) sensitizes the algae to photooxidative death. Photooxidative death and bleaching of photosynthetic pigments are separable phenomena. Photooxidative conditions were demonstrated in Israeli fish ponds using A. nidulans as the test organism during dense summer blooms, when dissolved CO(2) is low, and in winter, when water temperatures generally drop below 15 C. This finding suggests that photooxidative death may be responsible for the sudden decomposition of blue-green blooms in summer, and may be a factor in the absence of blue-green blooms in winter. PMID:4626540

  17. Biofuels from algae: challenges and potential.

    PubMed

    Hannon, Michael; Gimpel, Javier; Tran, Miller; Rasala, Beth; Mayfield, Stephen

    2010-09-01

    Algae biofuels may provide a viable alternative to fossil fuels; however, this technology must overcome a number of hurdles before it can compete in the fuel market and be broadly deployed. These challenges include strain identification and improvement, both in terms of oil productivity and crop protection, nutrient and resource allocation and use, and the production of co-products to improve the economics of the entire system. Although there is much excitement about the potential of algae biofuels, much work is still required in the field. In this article, we attempt to elucidate the major challenges to economic algal biofuels at scale, and improve the focus of the scientific community to address these challenges and move algal biofuels from promise to reality. PMID:21833344

  18. Harvesting of Algae by Froth Flotation

    PubMed Central

    Levin, Gilbert V.; Clendenning, John R.; Gibor, Ahron; Bogar, Frederick D.

    1962-01-01

    A highly efficient froth flotation procedure has been developed for harvesting algae from dilute suspensions. The method does not depend upon the addition of flotants. Harvesting is carried out in a long column containing the feed solution which is aerated from below. A stable column of foam is produced and harvested from a side arm near the top of the column. The cell concentration of the harvest is a function of pH, aeration rate, aerator porosity, feed concentration, and height of foam in the harvesting column. The economic aspects of this process seem favorable for mass harvesting of algae for food or other purposes. Images FIG. 1 FIG. 2a FIG. 2b PMID:14464557

  19. Biofuels from algae: challenges and potential

    PubMed Central

    Hannon, Michael; Gimpel, Javier; Tran, Miller; Rasala, Beth; Mayfield, Stephen

    2011-01-01

    Algae biofuels may provide a viable alternative to fossil fuels; however, this technology must overcome a number of hurdles before it can compete in the fuel market and be broadly deployed. These challenges include strain identification and improvement, both in terms of oil productivity and crop protection, nutrient and resource allocation and use, and the production of co-products to improve the economics of the entire system. Although there is much excitement about the potential of algae biofuels, much work is still required in the field. In this article, we attempt to elucidate the major challenges to economic algal biofuels at scale, and improve the focus of the scientific community to address these challenges and move algal biofuels from promise to reality. PMID:21833344

  20. Algae columns with anodic stripping voltammetric detection

    SciTech Connect

    Kubiak, W.W.; Wang, J.; Darnall, D.

    1989-03-01

    The use of silica-immobilized algal cells for on-line column separation in conjunction with continuous monitoring of trace metals is described. Algae-silica preparations are highly suitable for flow analysis as they couple the unique reactivity patterns and high binding capacity of algal biomass with the hydrodynamic and mechanical features of porous silica. Such advantages are illustrated by using on-line anodic stripping voltammetry and the alga Chlorella pyrenidosa. Selective and exhaustive removal of interfering constituents circumvents common problems such as overlapping peaks and intermetallic effects. Effects of flow rate, pH, operation time, and other variables are reported. The system is characterized by high durability, simplicity, and economy and offers an attractive alternative to prevalent columns used for flow analysis.

  1. Engineering algae for biohydrogen and biofuel production.

    PubMed

    Beer, Laura L; Boyd, Eric S; Peters, John W; Posewitz, Matthew C

    2009-06-01

    There is currently substantial interest in utilizing eukaryotic algae for the renewable production of several bioenergy carriers, including starches for alcohols, lipids for diesel fuel surrogates, and H2 for fuel cells. Relative to terrestrial biofuel feedstocks, algae can convert solar energy into fuels at higher photosynthetic efficiencies, and can thrive in salt water systems. Recently, there has been considerable progress in identifying relevant bioenergy genes and pathways in microalgae, and powerful genetic techniques have been developed to engineer some strains via the targeted disruption of endogenous genes and/or transgene expression. Collectively, the progress that has been realized in these areas is rapidly advancing our ability to genetically optimize the production of targeted biofuels. PMID:19560336

  2. Hydrogen production by photosynthetic green algae.

    PubMed

    Ghirardi, Maria L

    2006-08-01

    Oxygenic photosynthetic organisms such as cyanobacteria, green algae and diatoms are capable of absorbing light and storing up to 10-13% of its energy into the H-H bond of hydrogen gas. This process, which takes advantage of the photosynthetic apparatus of these organisms to convert sunlight into chemical energy, could conceivably be harnessed for production of significant amounts of energy from a renewable resource, water. The harnessed energy could then be coupled to a fuel cell for electricity generation and recycling of water molecules. In this review, current biochemical understanding of this reaction in green algae, and some of the major challenges facing the development of future commercial algal photobiological systems for H2 production have been discussed. PMID:17133763

  3. The persistence of haplodiploidy in algae.

    PubMed

    Klinger, T

    1993-07-01

    Haplodiploid life cycles are especially well represented among the eukaryotic algae. The widespread retention of haplodiploidy among diverse algal groups provides us with the opportunity to consider haplodiploidy as a stable rather than transitional life history trait and to speculate on the selective mechanisms that could be responsible for its persistence. In doing so, we could gain added insights into the evolution of sex itself. PMID:21236162

  4. Dermatitis from purified sea algae toxin (debromoaplysiatoxin).

    PubMed

    Solomon, A E; Stoughton, R B

    1978-09-01

    Cutaneous inflammation was induced by debromoaplysiatoxin, a purified toxin extracted from Lyngbya majuscula Gomont. This alga causes a seaweed dermatitis that occurs in persons who have swum off the coast of Oahu in Hawaii. By topical application, the toxin was found to produce an irritant pustular folliculitis in humans and to cause a severe cutaneous inflammatory reaction in the rabbit and in hairless mice. PMID:686747

  5. Algae-Derived Dietary Ingredients Nourish Animals

    NASA Technical Reports Server (NTRS)

    2015-01-01

    In the 1980s, Columbia, Maryland-based Martek Biosciences Corporation worked with Ames Research Center to pioneer the use of microalgae as a source of essential omega-3 fatty acids, work that led the company to develop its highly successful Formulaid product. Now the Nutritional Products Division of Royal DSM, the company also manufactures DHAgold, a nutritional supplement for pets, livestock and farm-raised fish that uses algae to deliver docosahexaenoic acid (DHA).

  6. Selenium Uptake and Volatilization by Marine Algae

    NASA Astrophysics Data System (ADS)

    Luxem, Katja E.; Vriens, Bas; Wagner, Bettina; Behra, Renata; Winkel, Lenny H. E.

    2015-04-01

    Selenium (Se) is an essential trace nutrient for humans. An estimated one half to one billion people worldwide suffer from Se deficiency, which is due to low concentrations and bioavailability of Se in soils where crops are grown. It has been hypothesized that more than half of the atmospheric Se deposition to soils is derived from the marine system, where microorganisms methylate and volatilize Se. Based on model results from the late 1980s, the atmospheric flux of these biogenic volatile Se compounds is around 9 Gt/year, with two thirds coming from the marine biosphere. Algae, fungi, and bacteria are known to methylate Se. Although algal Se uptake, metabolism, and methylation influence the speciation and bioavailability of Se in the oceans, these processes have not been quantified under environmentally relevant conditions and are likely to differ among organisms. Therefore, we are investigating the uptake and methylation of the two main inorganic Se species (selenate and selenite) by three globally relevant microalgae: Phaeocystis globosa, the coccolithophorid Emiliania huxleyi, and the diatom Thalassiosira oceanica. Selenium uptake and methylation were quantified in a batch experiment, where parallel gas-tight microcosms in a climate chamber were coupled to a gas-trapping system. For E. huxleyi, selenite uptake was strongly dependent on aqueous phosphate concentrations, which agrees with prior evidence that selenite uptake by phosphate transporters is a significant Se source for marine algae. Selenate uptake was much lower than selenite uptake. The most important volatile Se compounds produced were dimethyl selenide, dimethyl diselenide, and dimethyl selenyl sulfide. Production rates of volatile Se species were larger with increasing intracellular Se concentration and in the decline phase of the alga. Similar experiments are being carried out with P. globosa and T. oceanica. Our results indicate that marine algae are important for the global cycling of Se, especially in low phosphate regimes such as oligotrophic waters and late stage phytoplankton blooms.

  7. Fermentation metabolism and its evolution in algae

    PubMed Central

    Catalanotti, Claudia; Yang, Wenqiang; Posewitz, Matthew C.; Grossman, Arthur R.

    2013-01-01

    Fermentation or anoxic metabolism allows unicellular organisms to colonize environments that become anoxic. Free-living unicellular algae capable of a photoautotrophic lifestyle can also use a range of metabolic circuitry associated with different branches of fermentation metabolism. While algae that perform mixed-acid fermentation are widespread, the use of anaerobic respiration is more typical of eukaryotic heterotrophs. The occurrence of a core set of fermentation pathways among the algae provides insights into the evolutionary origins of these pathways, which were likely derived from a common ancestral eukaryote. Based on genomic, transcriptomic, and biochemical studies, anaerobic energy metabolism has been examined in more detail in Chlamydomonas reinhardtii (Chlamydomonas) than in any other photosynthetic protist. This green alga is metabolically flexible and can sustain energy generation and maintain cellular redox balance under a variety of different environmental conditions. Fermentation metabolism in Chlamydomonas appears to be highly controlled, and the flexible use of the different branches of fermentation metabolism has been demonstrated in studies of various metabolic mutants. Additionally, when Chlamydomonas ferments polysaccharides, it has the ability to eliminate part of the reductant (to sustain glycolysis) through the production of H2, a molecule that can be developed as a source of renewable energy. To date, little is known about the specific role(s) of the different branches of fermentation metabolism, how photosynthetic eukaryotes sense changes in environmental O2 levels, and the mechanisms involved in controlling these responses, at both the transcriptional and post-transcriptional levels. In this review, we focus on fermentation metabolism in Chlamydomonas and other protists, with only a brief discussion of plant fermentation when relevant, since it is thoroughly discussed in other articles in this volume. PMID:23734158

  8. Algae as reservoirs for coral pathogens.

    PubMed

    Sweet, Michael J; Bythell, John C; Nugues, Maggy M

    2013-01-01

    Benthic algae are associated with coral death in the form of stress and disease. It's been proposed that they release exudates, which facilitate invasion of potentially pathogenic microbes at the coral-algal interface, resulting in coral disease. However, the original source of these pathogens remains unknown. This study examined the ability of benthic algae to act as reservoirs of coral pathogens by characterizing surface associated microbes associated with major Caribbean and Indo-Pacific algal species/types and by comparing them to potential pathogens of two dominant coral diseases: White Syndrome (WS) in the Indo-Pacific and Yellow Band Disease (YBD) in the Caribbean. Coral and algal sampling was conducted simultaneously at the same sites to avoid spatial effects. Potential pathogens were defined as those absent or rare in healthy corals, increasing in abundance in healthy tissues adjacent to a disease lesion, and dominant in disease lesions. Potentially pathogenic bacteria were detected in both WS and YBD and were also present within the majority of algal species/types (54 and 100% for WS and YBD respectively). Pathogenic ciliates were associated only with WS and not YBD lesions and these were also present in 36% of the Indo-Pacific algal species. Although potential pathogens were associated with many algal species, their presence was inconsistent among replicate algal samples and detection rates were relatively low, suggestive of low density and occurrence. At the community level, coral-associated microbes irrespective of the health of their host differed from algal-associated microbes, supporting that algae and corals have distinctive microbial communities associated with their tissue. We conclude that benthic algae are common reservoirs for a variety of different potential coral pathogens. However, algal-associated microbes alone are unlikely to cause coral death. Initial damage or stress to the coral via other competitive mechanisms is most likely a prerequisite to potential transmission of these pathogens. PMID:23936086

  9. Algae as Reservoirs for Coral Pathogens

    PubMed Central

    Sweet, Michael J.; Bythell, John C.; Nugues, Maggy M.

    2013-01-01

    Benthic algae are associated with coral death in the form of stress and disease. It's been proposed that they release exudates, which facilitate invasion of potentially pathogenic microbes at the coral-algal interface, resulting in coral disease. However, the original source of these pathogens remains unknown. This study examined the ability of benthic algae to act as reservoirs of coral pathogens by characterizing surface associated microbes associated with major Caribbean and Indo-Pacific algal species/types and by comparing them to potential pathogens of two dominant coral diseases: White Syndrome (WS) in the Indo-Pacific and Yellow Band Disease (YBD) in the Caribbean. Coral and algal sampling was conducted simultaneously at the same sites to avoid spatial effects. Potential pathogens were defined as those absent or rare in healthy corals, increasing in abundance in healthy tissues adjacent to a disease lesion, and dominant in disease lesions. Potentially pathogenic bacteria were detected in both WS and YBD and were also present within the majority of algal species/types (54 and 100% for WS and YBD respectively). Pathogenic ciliates were associated only with WS and not YBD lesions and these were also present in 36% of the Indo-Pacific algal species. Although potential pathogens were associated with many algal species, their presence was inconsistent among replicate algal samples and detection rates were relatively low, suggestive of low density and occurrence. At the community level, coral-associated microbes irrespective of the health of their host differed from algal-associated microbes, supporting that algae and corals have distinctive microbial communities associated with their tissue. We conclude that benthic algae are common reservoirs for a variety of different potential coral pathogens. However, algal-associated microbes alone are unlikely to cause coral death. Initial damage or stress to the coral via other competitive mechanisms is most likely a prerequisite to potential transmission of these pathogens. PMID:23936086

  10. Functional properties of carotenoids originating from algae.

    PubMed

    Christaki, Efterpi; Bonos, Eleftherios; Giannenas, Ilias; Florou-Paneri, Panagiota

    2013-01-15

    Carotenoids are isoprenoid molecules which are synthesised de novo by photosynthetic plants, fungi and algae and are responsible for the orange, yellow and some red colours of various fruits and vegetables. Carotenoids are lipophilic compounds, some of which act as provitamins A. These compounds can be divided into xanthophylls and carotenes. Many macroalgae and microalgae are rich in carotenoids, where these compounds aid in the absorption of sunlight. Industrially, these carotenoids are used as food pigments (in dairy products, beverages, etc.), as feed additives, in cosmetics and in pharmaceuticals, especially nowadays when there is an increasing demand by consumers for natural products. Production of carotenoids from algae has many advantages compared to other sources; for example, their production is cheap, easy and environmentally friendly; their extraction is easier, with higher yields, and there is no lack of raw materials or limited seasonal variation. Recently, there has been considerable interest in dietary carotenoids with respect to their antioxidant properties and their ability to reduce the incidence of some chronic diseases where free radicals are involved. Possibly, carotenoids protect cells from oxidative stress by quenching singlet oxygen damage with various mechanisms. Therefore, carotenoids derived from algae could be a leading natural resource in the research for potential functional ingredients. PMID:23044813

  11. New records of marine algae in Vietnam

    NASA Astrophysics Data System (ADS)

    Le Hau, Nhu; Ly, Bui Minh; Van Huynh, Tran; Trung, Vo Thanh

    2015-06-01

    In May, 2013, a scientific expedition was organized by the Vietnam Academy of Science and Technology (VAST) and the Far Eastern Branch of the Russian Academy of Sciences (FEBRAS) through the frame of the VAST-FEBRAS International Collaboration Program. The expedition went along the coast of Vietnam from Quang Ninh to Kien Giang. The objective was to collect natural resources to investigate the biological and biochemical diversity of the territorial waters of Vietnam. Among the collected algae, six taxa are new records for the Vietnam algal flora. They are the red algae Titanophora pikeana (Dickie) Feldmann from Cu Lao Xanh Island, Laurencia natalensis Kylin from Tho Chu Island, Coelothrix irregularis (Harvey) Børgesen from Con Dao Island, the green algae Caulerpa oligophylla Montagne, Caulerpa andamanensis (W.R. Taylor) Draisma, Prudhomme et Sauvage from Phu Quy Island, and Caulerpa falcifolia Harvey & Bailey from Ly Son Island. The seaweed flora of Vietnam now counts 833 marine algal taxa, including 415 Rhodophyta, 147 Phaeophyceae, 183 Chlorophyta, and 88 Cyanobacteria.

  12. Screening for bioactive compounds from algae.

    PubMed

    Plaza, M; Santoyo, S; Jaime, L; Garca-Blairsy Reina, G; Herrero, M; Seorns, F J; Ibez, E

    2010-01-20

    In the present work, a comprehensive methodology to carry out the screening for novel natural functional compounds is presented. To do that, a new strategy has been developed including the use of unexplored natural sources (i.e., algae and microalgae) together with environmentally clean extraction techniques and advanced analytical tools. The developed procedure allows also estimating the functional activities of the different extracts obtained and even more important, to correlate these activities with their particular chemical composition. By applying this methodology it has been possible to carry out the screening for bioactive compounds in the algae Himanthalia elongata and the microalgae Synechocystis sp. Both algae produced active extracts in terms of both antioxidant and antimicrobial activity. The obtained pressurized liquid extracts were chemically characterized by GC-MS and HPLC-DAD. Different fatty acids and volatile compounds with antimicrobial activity were identified, such as phytol, fucosterol, neophytadiene or palmitic, palmitoleic and oleic acids. Based on the results obtained, ethanol was selected as the most appropriate solvent to extract this kind of compounds from the natural sources studied. PMID:19375880

  13. Electro-coagulation-flotation process for algae removal.

    PubMed

    Gao, Shanshan; Yang, Jixian; Tian, Jiayu; Ma, Fang; Tu, Gang; Du, Maoan

    2010-05-15

    Algae in surface water have been a long-term issue all over the world, due to their adverse influence on drinking water treatment process as well as drinking water quality. The algae removal by electro-coagulation-flotation (ECF) technology was investigated in this paper. The results indicated that aluminum was an excellent electrode material for algae removal as compared with iron. The optimal parameters determined were: current density=1 mA/cm(2), pH=4-7, water temperature=18-36 degrees C, algae density=0.55 x 10(9)-1.55 x 10(9) cells/L. Under the optimal conditions, 100% of algae removal was achieved with the energy consumption as low as 0.4 kWh/m(3). The ECF performed well in acid and neutral conditions. At low initial pH of 4-7, the cell density of algae was effectively removed in the ECF, mainly through the charge neutralization mechanism; while the algae removal worsened when the pH increased (7-10), and the main mechanism shifted to sweeping flocculation and enmeshment. The mechanisms for algae removal at different pH were also confirmed by atomic force microscopy (AFM) analysis. Furthermore, initial cell density and water temperature could also influence the algae removal. Overall, the results indicated that the ECF technology was effective for algae removal, from both the technical and economical points of view. PMID:20042280

  14. Environmental life cycle comparison of algae to other bioenergy feedstocks.

    PubMed

    Clarens, Andres F; Resurreccion, Eleazer P; White, Mark A; Colosi, Lisa M

    2010-03-01

    Algae are an attractive source of biomass energy since they do not compete with food crops and have higher energy yields per area than terrestrial crops. In spite of these advantages, algae cultivation has not yet been compared with conventional crops from a life cycle perspective. In this work, the impacts associated with algae production were determined using a stochastic life cycle model and compared with switchgrass, canola, and corn farming. The results indicate that these conventional crops have lower environmental impacts than algae in energy use, greenhouse gas emissions, and water regardless of cultivation location. Only in total land use and eutrophication potential do algae perform favorably. The large environmental footprint of algae cultivation is driven predominantly by upstream impacts, such as the demand for CO(2) and fertilizer. To reduce these impacts, flue gas and, to a greater extent, wastewater could be used to offset most of the environmental burdens associated with algae. To demonstrate the benefits of algae production coupled with wastewater treatment, the model was expanded to include three different municipal wastewater effluents as sources of nitrogen and phosphorus. Each provided a significant reduction in the burdens of algae cultivation, and the use of source-separated urine was found to make algae more environmentally beneficial than the terrestrial crops. PMID:20085253

  15. Biology and systematics of heterokont and haptophyte algae.

    PubMed

    Andersen, Robert A

    2004-10-01

    In this paper, I review what is currently known of phylogenetic relationships of heterokont and haptophyte algae. Heterokont algae are a monophyletic group that is classified into 17 classes and represents a diverse group of marine, freshwater, and terrestrial algae. Classes are distinguished by morphology, chloroplast pigments, ultrastructural features, and gene sequence data. Electron microscopy and molecular biology have contributed significantly to our understanding of their evolutionary relationships, but even today class relationships are poorly understood. Haptophyte algae are a second monophyletic group that consists of two classes of predominately marine phytoplankton. The closest relatives of the haptophytes are currently unknown, but recent evidence indicates they may be part of a large assemblage (chromalveolates) that includes heterokont algae and other stramenopiles, alveolates, and cryptophytes. Heterokont and haptophyte algae are important primary producers in aquatic habitats, and they are probably the primary carbon source for petroleum products (crude oil, natural gas). PMID:21652306

  16. Eradication of algae in ships' ballast water by electrolyzing

    NASA Astrophysics Data System (ADS)

    Dang, Kun; Sun, Pei-Ting; Xiao, Jing-Kun; Song, Yong-Xin

    2006-12-01

    In order to verify the effectiveness of electrolytic treatment on ships ballast water, experiments are carried out by a pilot system in laboratory. The raw seawater and seawater with different concentrations of different algae are simulated as ships ballast water. The algae in the raw seawater can be killed if it is treated by electrolysis with an initial residual chlorine concentration of 5 mg/L. If the seawater with one kind of algae (Nitzschia closterum, Dicrateria spp., or Pyramidomonnas sp.105cells/mL) is treated by electrolysis with an initial residual chlorine concentration of 5 mg/L, the alga can be sterilized. If the seawater with one kind of algae (Dunaliella sp., Platymonas or Chlorella spp.) is directly treated by electrolyzing with an initial residual chlorine concentration of 4 mg/L, the instant mortality changes with the concentration of different algae. However, after 72 hours, in all treated samples, there are no live algal cells found.

  17. Exploring the potential of algae/bacteria interactions.

    PubMed

    Kouzuma, Atsushi; Watanabe, Kazuya

    2015-06-01

    Algae are primary producers in aquatic ecosystems, where heterotrophic bacteria grow on organics produced by algae and recycle nutrients. Ecological studies have identified the co-occurrence of particular species of algae and bacteria, suggesting the presence of their specific interactions. Algae/bacteria interactions are categorized into nutrient exchange, signal transduction and gene transfer. Studies have examined how these interactions shape aquatic communities and influence geochemical cycles in the natural environment. In parallel, efforts have been made to exploit algae for biotechnology processes, such as water treatment and bioenergy production, where bacteria influence algal activities in various ways. We suggest that better understanding of mechanisms underlying algae/bacteria interactions will facilitate the development of more efficient and/or as-yet-unexploited biotechnology processes. PMID:25744715

  18. Algae to Bio-Crude in Less Than 60 Minutes

    SciTech Connect

    Elliott, Doug

    2013-12-17

    Engineers have created a chemical process that produces useful crude oil just minutes after engineers pour in harvested algae -- a verdant green paste with the consistency of pea soup. The PNNL team combined several chemical steps into one continuous process that starts with an algae slurry that contains as much as 80 to 90 percent water. Most current processes require the algae to be dried -- an expensive process that takes a lot of energy. The research has been licensed by Genifuel Corp.

  19. Bromophenols from marine algae with potential anti-diabetic activities

    NASA Astrophysics Data System (ADS)

    Lin, Xiukun; Liu, Ming

    2012-12-01

    Marine algae contain various bromophenols with a variety of biological activities, including antimicrobial, anticancer, and anti-diabetic effects. Here, we briefly review the recent progress in researches on the biomaterials from marine algae, emphasizing the relationship between the structure and the potential anti-diabetic applications. Bromophenols from marine algae display their hyperglycemic effects by inhibiting the activities of protein tyrosine phosphatase 1B, α-glucosidase, as well as other mechanisms.

  20. Algae to Bio-Crude in Less Than 60 Minutes

    ScienceCinema

    Elliott, Doug

    2014-06-02

    Engineers have created a chemical process that produces useful crude oil just minutes after engineers pour in harvested algae -- a verdant green paste with the consistency of pea soup. The PNNL team combined several chemical steps into one continuous process that starts with an algae slurry that contains as much as 80 to 90 percent water. Most current processes require the algae to be dried -- an expensive process that takes a lot of energy. The research has been licensed by Genifuel Corp.

  1. 21 CFR 73.275 - Dried algae meal.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Dried algae meal. 73.275 Section 73.275 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.275 Dried algae meal. (a) Identity. The color additive dried algae meal is a dried mixture of...

  2. Method for producing hydrogen and oxygen by use of algae

    DOEpatents

    Greenbaum, E.

    1982-06-16

    Efficiency of process for producing H/sub 2/ by subjecting algae in an aqueous phase to light irradiation is increased by culturing algae which has been bleached during a first period of irradiation in a culture medium in an aerobic atmosphere until it has regained color and then subjecting this algae to a second period of irradiation wherein hydrogen is produced at an enhanced rate.

  3. Method for producing hydrogen and oxygen by use of algae

    DOEpatents

    Greenbaum, Elias

    1984-01-01

    Efficiency of process for producing H.sub.2 by subjecting algae in an aqueous phase to light irradiation is increased by culturing algae which has been bleached during a first period of irradiation in a culture medium in an aerobic atmosphere until it has regained color and then subjecting this algae to a second period of irradiation wherein hydrogen is produced at an enhanced rate.

  4. Method and apparatus for iterative lysis and extraction of algae

    SciTech Connect

    Chew, Geoffrey; Boggs, Tabitha; Dykes, Jr., H. Waite H.; Doherty, Stephen J.

    2015-12-01

    A method and system for processing algae involves the use of an ionic liquid-containing clarified cell lysate to lyse algae cells. The resulting crude cell lysate may be clarified and subsequently used to lyse algae cells. The process may be repeated a number of times before a clarified lysate is separated into lipid and aqueous phases for further processing and/or purification of desired products.

  5. Cell to substratum and cell to cell interactions of microalgae.

    PubMed

    Ozkan, Altan; Berberoglu, Halil

    2013-12-01

    This paper reports the cell to substratum and cell to cell interactions of a diverse group of microalgae based on the Extended Derjaguin, Landau, Verwey, Overbeek (XDLVO) approach using the previously reported physico-chemical surface properties. The microalgae included 10 different species of green algae and diatoms from both freshwater and saltwater environments while the substrata included glass, indium-tin oxide (ITO), stainless steel, polycarbonate, polyethylene, and polystryrene. The results indicated that acid-base interactions were the dominating mechanism of interaction for microalgae. For green algae, if at least one of the interacting surfaces was hydrophobic, adhesion at primary minimum was predicted without any energy barrier. However, most diatom systems featured energy barriers for adhesion due to repulsive van der Waals interactions. The results reported in this study are expected to provide useful data and insight into the interaction mechanisms of microalgae cells with each other and with substrata for a number of practical applications including prevention of biofouling of photobioreactors and other man-made surfaces, promotion of biofilm formation in algal biofilm photobioreactors, and developing bioflocculation strategies for energy efficient harvesting of algal biomass. Particularly, Botryococcus braunii and Cerithiopsis fusiformis were identified as promising species for biofloccuation and biofilm formation in freshwater and saltwater aquatic systems, respectively. Finally, based on the observed trends in this study, use of hydrophilic algae and hydrophilic coatings over surfaces are recommended for minimizing biofouling in aquatic systems. PMID:24004676

  6. Exploring the potential of using algae in cosmetics.

    PubMed

    Wang, Hui-Min David; Chen, Ching-Chun; Huynh, Pauline; Chang, Jo-Shu

    2015-05-01

    The applications of microalgae in cosmetic products have recently received more attention in the treatment of skin problems, such as aging, tanning and pigment disorders. There are also potential uses in the areas of anti-aging, skin-whitening, and pigmentation reduction products. While algae species have already been used in some cosmetic formulations, such as moisturizing and thickening agents, algae remain largely untapped as an asset in this industry due to an apparent lack of utility as a primary active ingredient. This review article focuses on integrating studies on algae pertinent to skin health and beauty, with the purpose of identifying serviceable algae functions in practical cosmetic uses. PMID:25537136

  7. Algae Bioreactor Using Submerged Enclosures with Semi-Permeable Membranes

    NASA Technical Reports Server (NTRS)

    Trent, Jonathan D (Inventor); Gormly, Sherwin J (Inventor); Embaye, Tsegereda N (Inventor); Delzeit, Lance D (Inventor); Flynn, Michael T (Inventor); Liggett, Travis A (Inventor); Buckwalter, Patrick W (Inventor); Baertsch, Robert (Inventor)

    2013-01-01

    Methods for producing hydrocarbons, including oil, by processing algae and/or other micro-organisms in an aquatic environment. Flexible bags (e.g., plastic) with CO.sub.2/O.sub.2 exchange membranes, suspended at a controllable depth in a first liquid (e.g., seawater), receive a second liquid (e.g., liquid effluent from a "dead zone") containing seeds for algae growth. The algae are cultivated and harvested in the bags, after most of the second liquid is removed by forward osmosis through liquid exchange membranes. The algae are removed and processed, and the bags are cleaned and reused.

  8. A method for RNA isolation from marine macro-algae.

    PubMed

    Su, X; Gibor, A

    1988-11-01

    Sulfated, carboxylic polysaccharides and polyphenols found in marine macro-algae interfere with RNA isolation from these plants and inhibit RNA activities in vitro. Methods based on differential precipitation of RNA or carbohydrates in high salts were used to eliminate the acidic carbohydrates. To protect RNA from inactivation by oxidized polyphenols, strong reducing reagents were used to prevent polyphenol oxidation. RNA was successfully isolated from Macro-cystis pyrifera (brown alga), Porphyra schizophylla (red alga), and Enteromorpha intestinalis (green alga). mRNA isolated from the total RNA was shown to be translationally active. PMID:2467581

  9. Method and apparatus for lysing and processing algae

    DOEpatents

    Chew, Geoffrey; Reich, Alton J.; Dykes, Jr., H. Waite H.; Di Salvo, Roberto

    2013-03-05

    Methods and apparatus for processing algae are described in which a hydrophilic ionic liquid is used to lyse algae cells at lower temperatures than existing algae processing methods. A salt or salt solution is used as a separation agent and to remove water from the ionic liquid, allowing the ionic liquid to be reused. The used salt may be dried or concentrated and reused. The relatively low lysis temperatures and recycling of the ionic liquid and salt reduce the environmental impact of the algae processing while providing biofuels and other useful products.

  10. A technical evaluation of biodiesel from vegetable oils vs. algae. Will algae-derived biodiesel perform?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biodiesel, one of the most prominent renewable alternative fuels, can be derived from a variety of sources including vegetable oils, animal fats and used cooking oils as well as alternative sources such as algae. While issues such as land-use change, food vs. fuel, feedstock availability, and produc...

  11. Biodiesel from algae: challenges and prospects.

    PubMed

    Scott, Stuart A; Davey, Matthew P; Dennis, John S; Horst, Irmtraud; Howe, Christopher J; Lea-Smith, David J; Smith, Alison G

    2010-06-01

    Microalgae offer great potential for exploitation, including the production of biodiesel, but the process is still some way from being carbon neutral or commercially viable. Part of the problem is that there is little established background knowledge in the area. We should look both to achieve incremental steps and to increase our fundamental understanding of algae to identify potential paradigm shifts. In doing this, integration of biology and engineering will be essential. In this review we present an overview of a potential algal biofuel pipeline, and focus on recent work that tackles optimization of algal biomass production and the content of fuel molecules within the algal cell. PMID:20399634

  12. Algae-based oral recombinant vaccines

    PubMed Central

    Specht, Elizabeth A.; Mayfield, Stephen P.

    2014-01-01

    Recombinant subunit vaccines are some of the safest and most effective vaccines available, but their high cost and the requirement of advanced medical infrastructure for administration make them impractical for many developing world diseases. Plant-based vaccines have shifted that paradigm by paving the way for recombinant vaccine production at agricultural scale using an edible host. However, enthusiasm for molecular pharming in food crops has waned in the last decade due to difficulty in developing transgenic crop plants and concerns of contaminating the food supply. Microalgae could be poised to become the next candidate in recombinant subunit vaccine production, as they present several advantages over terrestrial crop plant-based platforms including scalable and contained growth, rapid transformation, easily obtained stable cell lines, and consistent transgene expression levels. Algae have been shown to accumulate and properly fold several vaccine antigens, and efforts are underway to create recombinant algal fusion proteins that can enhance antigenicity for effective orally delivered vaccines. These approaches have the potential to revolutionize the way subunit vaccines are made and delivered from costly parenteral administration of purified protein, to an inexpensive oral algae tablet with effective mucosal and systemic immune reactivity. PMID:24596570

  13. Algae Biofuels Co-Location Assessment Tool

    SciTech Connect

    2013-09-18

    ABCLAT was built to help any model user with spatially explicit Nitrogen, Phosphorous, and Carbon Dioxide nutrient flux information, and solar resource information evaluate algal cultivation potential. Initial applications of this modeling framework include Algae Biofuels Co-Location Assessment Tool Canada and Australia. The Canadian application was copyrighted November 29th 2011 as the Algae Biofuels Co-Location Assessment Tool for Canada. This copyright assertion is for the general framework from which any country or region with the requisite data could create a regionally specific application. The ABCLAT model framework developed by SNL looks at the growth potential in a given region as a function of available nutrients from wastewater and other sources, carbon dioxide from power plants, available solar potential, and if available, land cover and use information. The model framework evaluates the biomass potential, fixed carbon dioxide, potential algal biocrude and required land area for nutrient sources. ABCLAT is built with an object-oriented software program that can provide an easy to use interface for exploring questions related to aigal biomass production.

  14. Effects of nitrogen dioxide on algae

    SciTech Connect

    Wodzinski, R.S.; Alexander, M.

    1980-01-01

    Photosynthetic activity of Anabaena flos-aquae in a soil suspension at an initial pH of 4.9 was almost totally eliminated after 3 days of exposure to 5.0 ppM (..mu..l/liter) NO/sub 2/, at which time the pH had fallen to 3.9. In contrast, A. flos-aquae in soil suspensions at an initial pH of 6.0 was not inhibited after 3 days by 5.0 ppM NO/sub 2/, but the activity was reduced by half in the presence of 15.0 ppM NO/sub 2/; the pH was 6.5 and 5.8, respectively, in the NO/sub 2/-treated samples on day 3. Photosynthesis by the green algae Chlamydomonas reinhardtii and Ankistrodesmus falcatus in soil suspensions at an initial pH of approx. 4.2 was not appreciably affected by 15.0 ppM of NO/sub 2/ after 3 days, at which time the pH had fallen below 4.0. The high levels of NO/sub 2/ and low pH values required for toxicity suggest that blue-green and green algae probably will not be affected directly by NO/sub 2/ in polluted air.

  15. Effects of nitrogen dioxide on algae

    SciTech Connect

    Wodzinski, R.S.; Alexander, M.

    1980-01-01

    Photosynthetic activity of Anabaena flos-aquae in a soil suspension at an initial pH of 4.9 was almost totally eliminated after 3 days of exposure to 5.0 ppm (..mu..l/liter) NO/sub 2/, at which time the pH had fallen to 3.9. In contrast, A. flos-aquae in soil suspensions at an initial pH of 6.0 was not inhibited after 3 days by 5.0 ppm NO/sub 2/, but the activity was reduced by half in the presence of 15.0 ppm NO/sub 2/; the pH was 6.5 and 5.8, respectively, in the NO/sub 2/-treated samples on day 3. Photosynthesis by the green algae Chlamydomonas reinhardtii and Ankistrodesmus falcatus in soil suspensions at an initial pH of approx 4.2 was not appreciably affected by 15.0 ppm of NO/sub 2/ after 3 days, at which time the pH had fallen below 4.0. The high levels of NO/sub 2/ and low pH values required for toxicity suggest that blue-green and green algae probably will not be affected directly by NO/sub 2/ in polluted air.

  16. Respiratory Chain of Colorless Algae II. Cyanophyta

    PubMed Central

    Webster, D. A.; Hackett, D. P.

    1966-01-01

    Whole cell difference spectra of the blue-green algae, Saprospira grandis, Leucothrix mucor, and Vitreoscilla sp. have one, or at the most 2, broad α-bands near 560 mμ. At −190° these bands split to give 4 peaks in the α-region for b and c-type cytochromes, but no α-band for a-type cytochromes is visible. The NADH oxidase activity of these organisms was shown to be associated with particulate fractions of cell homogenates. The response of this activity to inhibitors differed from the responses of the NADH oxidase activities of particulate preparations from the green algae and higher plants to the same inhibitors, but is more typical of certain bacteria. No cytochrome oxidase activity was present in these preparations. The respiration of Saprospira and Vitreoscilla can be light-reversibly inhibited by CO, and all 3 organisms have a CO-binding pigment whose CO complex absorbs near 570, 535, and 417 mμ. The action spectrum for the light reversal of CO-inhibited Vitreoscilla respiration shows maxima at 568, 534, and 416 mμ. The results suggest that the terminal oxidase in these blue-greens is an o-type cytochrome. Images PMID:5932404

  17. Algae Biofuels Co-Location Assessment Tool

    Energy Science and Technology Software Center (ESTSC)

    2013-09-18

    ABCLAT was built to help any model user with spatially explicit Nitrogen, Phosphorous, and Carbon Dioxide nutrient flux information, and solar resource information evaluate algal cultivation potential. Initial applications of this modeling framework include Algae Biofuels Co-Location Assessment Tool Canada and Australia. The Canadian application was copyrighted November 29th 2011 as the Algae Biofuels Co-Location Assessment Tool for Canada. This copyright assertion is for the general framework from which any country or region with themore » requisite data could create a regionally specific application. The ABCLAT model framework developed by SNL looks at the growth potential in a given region as a function of available nutrients from wastewater and other sources, carbon dioxide from power plants, available solar potential, and if available, land cover and use information. The model framework evaluates the biomass potential, fixed carbon dioxide, potential algal biocrude and required land area for nutrient sources. ABCLAT is built with an object-oriented software program that can provide an easy to use interface for exploring questions related to aigal biomass production.« less

  18. Salt-regulated mannitol metabolism in algae.

    PubMed

    Iwamoto, Koji; Shiraiwa, Yoshihiro

    2005-01-01

    Mannitol, one of the most widely occurring sugar alcohol compounds, is found in bacteria, fungi, algae, and plants. In these organisms the compound acts as a compatible solute and has multiple functions, including osmoregulation, storage, and regeneration of reducing power, and scavenging of active oxygen species. Because of the diverse functions of mannitol, introducing the ability to accumulate it has been a hallmark of attempts to generate highly salt-tolerant transgenic plants. However, transgenic plants have not yet improved significantly in their salt tolerance. Recently, we purified and characterized 2 enzymes that biosynthesize mannitol, mannitol-1-phosphate dehydrogenase (M1PDH) and mannitol-1-phosphate-specific phosphatase, from the marine red alga Caloglossa continua, which grows in estuarine areas where tide levels fluctuate frequently. The activation of Caloglossa M1PDH is unique in that it is regulated by salt concentration at enzyme level. In this review we focus on the metabolism of mannitol, mainly in marine photosynthetic organisms, and suggest how this might be applied to producing salt-tolerant transgenic plants. PMID:16088352

  19. Viruses and viruslike particles of eukaryotic algae.

    PubMed Central

    Van Etten, J L; Lane, L C; Meints, R H

    1991-01-01

    Until recently there was little interest or information on viruses and viruslike particles of eukaryotic algae. However, this situation is changing. In the past decade many large double-stranded DNA-containing viruses that infect two culturable, unicellular, eukaryotic green algae have been discovered. These viruses can be produced in large quantities, assayed by plaque formation, and analyzed by standard bacteriophage techniques. The viruses are structurally similar to animal iridoviruses, their genomes are similar to but larger (greater than 300 kbp) than that of poxviruses, and their infection process resembles that of bacteriophages. Some of the viruses have DNAs with low levels of methylated bases, whereas others have DNAs with high concentrations of 5-methylcytosine and N6-methyladenine. Virus-encoded DNA methyltransferases are associated with the methylation and are accompanied by virus-encoded DNA site-specific (restriction) endonucleases. Some of these enzymes have sequence specificities identical to those of known bacterial enzymes, and others have previously unrecognized specificities. A separate rod-shaped RNA-containing algal virus has structural and nucleotide sequence affinities to higher plant viruses. Quite recently, viruses have been associated with rapid changes in marine algal populations. In the next decade we envision the discovery of new algal viruses, clarification of their role in various ecosystems, discovery of commercially useful genes in these viruses, and exploitation of algal virus genetic elements in plant and algal biotechnology. Images PMID:1779928

  20. Algae-based oral recombinant vaccines.

    PubMed

    Specht, Elizabeth A; Mayfield, Stephen P

    2014-01-01

    Recombinant subunit vaccines are some of the safest and most effective vaccines available, but their high cost and the requirement of advanced medical infrastructure for administration make them impractical for many developing world diseases. Plant-based vaccines have shifted that paradigm by paving the way for recombinant vaccine production at agricultural scale using an edible host. However, enthusiasm for "molecular pharming" in food crops has waned in the last decade due to difficulty in developing transgenic crop plants and concerns of contaminating the food supply. Microalgae could be poised to become the next candidate in recombinant subunit vaccine production, as they present several advantages over terrestrial crop plant-based platforms including scalable and contained growth, rapid transformation, easily obtained stable cell lines, and consistent transgene expression levels. Algae have been shown to accumulate and properly fold several vaccine antigens, and efforts are underway to create recombinant algal fusion proteins that can enhance antigenicity for effective orally delivered vaccines. These approaches have the potential to revolutionize the way subunit vaccines are made and delivered - from costly parenteral administration of purified protein, to an inexpensive oral algae tablet with effective mucosal and systemic immune reactivity. PMID:24596570

  1. Energy from algae using microbial fuel cells.

    PubMed

    Velasquez-Orta, Sharon B; Curtis, Tom P; Logan, Bruce E

    2009-08-15

    Bioelectricity production from a phytoplankton, Chlorella vulgaris, and a macrophyte, Ulva lactuca was examined in single chamber microbial fuel cells (MFCs). MFCs were fed with the two algae (as powders), obtaining differences in energy recovery, degradation efficiency, and power densities. C. vulgaris produced more energy generation per substrate mass (2.5 kWh/kg), but U. lactuca was degraded more completely over a batch cycle (73 +/- 1% COD). Maximum power densities obtained using either single cycle or multiple cycle methods were 0.98 W/m(2) (277 W/m(3)) using C. vulgaris, and 0.76 W/m(2) (215 W/m(3)) using U. lactuca. Polarization curves obtained using a common method of linear sweep voltammetry (LSV) overestimated maximum power densities at a scan rate of 1 mV/s. At 0.1 mV/s, however, the LSV polarization data was in better agreement with single- and multiple-cycle polarization curves. The fingerprints of microbial communities developed in reactors had only 11% similarity to inocula and clustered according to the type of bioprocess used. These results demonstrate that algae can in principle, be used as a renewable source of electricity production in MFCs. PMID:19418564

  2. Comments on the Manuscript, "Biodiesel Production from Freshwater Algae"

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A recent publication (Vijayaragahavan, K.; Hemanathan, K., Biodiesel from freshwater algae, Energy Fuels, 2009, 23(11):5448-5453) on fuel production from algae is evaluated. It is discussed herein that the fuel discussed in that paper is not biodiesel, rather it probably consists of hydrocarbons. ...

  3. Mitigating ammonia nitrogen deficiency in dairy wastewaters for algae cultivation.

    PubMed

    Lu, Qian; Zhou, Wenguang; Min, Min; Ma, Xiaochen; Ma, Yiwei; Chen, Paul; Zheng, Hongli; Doan, Yen T T; Liu, Hui; Chen, Chi; Urriola, Pedro E; Shurson, Gerald C; Ruan, Roger

    2016-02-01

    This study demonstrated that the limiting factor to algae growth on dairy wastewater was the ammonia nitrogen deficiency. Dairy wastewaters were mixed with a slaughterhouse wastewater that has much higher ammonia nitrogen content. The results showed the mixing wastewaters improved the nutrient profiles and biomass yield at low cost. Algae grown on mixed wastewaters contained high protein (55.98-66.91%) and oil content (19.10-20.81%) and can be exploited to produce animal feed and biofuel. Furthermore, algae grown on mixed wastewater significantly reduced nutrient contents remained in the wastewater after treatment. By mitigating limiting factor to algae growth on dairy wastewaters, the key issue of low biomass yield of algae grown on dairy wastewaters was resolved and the wastewater nutrient removal efficiency was significantly improved by this study. PMID:26623940

  4. Algae Farming in Low Earth Orbit: Past Present and Future

    NASA Astrophysics Data System (ADS)

    Morrison, N.

    Algal strains used as a production engine represent a novel example of living mechanical systems with tremendous potential for applications in space. Algae use photosynthesis to create lipids, glycerin, and biomass, with different strains of algae producing different oils. Algae can be grown to produce many types of oils, with low, medium or long hydrocarbon chain lengths. This article examines the history of algae research, as well as its value to astronauts as both a food supplement and as an oxygen production and carbon sequester engine. Consideration is given to ways algae is currently being used and tested in space, followed by a look forward envisioning dynamic living technological systems that can help to sustain our race as we travel the void between stars.

  5. [Marine algae of Baja California Sur, Mexico: nutritional value].

    PubMed

    Carrillo Domnguez, Silvia; Casas Valdez, Margarita; Ramos Ramos, Felipe; Prez-Gil, Fernando; Snchez Rodrguez, Ignacio

    2002-12-01

    The Baja California Peninsula is one of the richest regions of seaweed resources in Mxico. The objective of this study was to determine the chemical composition of some marine algae species of Baja California Sur, with an economical potential due to their abundance and distribution, and to promote their use as food for human consumption and animal feeding. The algae studied were Green (Ulva spp., Enteromorpha intestinalis, Caulerpa sertularoides, Bryopsis hypnoides), Red (Laurencia johnstonii, Spyridia filamentosa, Hypnea valentiae) and Brown (Sargassum herporizum, S. sinicola, Padina durvillaei, Hydroclathrus clathrathus, Colpomenia sinuosa). The algae were dried and ground before analysis. In general, the results showed that algae had a protein level less than 11%, except L. johnstonii with 18% and low energy content. The ether extract content was lower than 1%. However, the algae were a good source of carbohydrates and inorganic matter. PMID:12868282

  6. Swimming like algae: biomimetic soft artificial cilia

    PubMed Central

    Sareh, Sina; Rossiter, Jonathan; Conn, Andrew; Drescher, Knut; Goldstein, Raymond E.

    2013-01-01

    Cilia are used effectively in a wide variety of biological systems from fluid transport to thrust generation. Here, we present the design and implementation of artificial cilia, based on a biomimetic planar actuator using soft-smart materials. This actuator is modelled on the cilia movement of the alga Volvox, and represents the cilium as a piecewise constant-curvature robotic actuator that enables the subsequent direct translation of natural articulation into a multi-segment ionic polymer metal composite actuator. It is demonstrated how the combination of optimal segmentation pattern and biologically derived per-segment driving signals reproduce natural ciliary motion. The amenability of the artificial cilia to scaling is also demonstrated through the comparison of the Reynolds number achieved with that of natural cilia. PMID:23097503

  7. Effective viscosity of actively swimming algae suspensions

    NASA Astrophysics Data System (ADS)

    Ewoldt, Randy; Caretta, Lucas; Chengala, Anwar; Sheng, Jian

    2010-11-01

    Suspensions of actively swimming microorganisms exhibit an effective viscosity which may depend on volume fraction, cell shape, and the nature of locomotion (e.g. "pushers" vs. "pullers"). Here we report experimental measurements of shear viscosity for suspensions of unicellular green algae (Dunaliella primolecta, a biflagellated "puller"). We use a cone-and-plate rheometer to measure the dynamic shear viscosity for both motile and non-motile suspensions of D. primolecta. Viscosity increases with concentration for both cases, but the active suspensions of "pullers" have a comparatively lower effective viscosity than passive suspensions. This observation contrasts recently proposed theories which predict that "pullers" should instead have a higher viscosity than non-motile suspensions. Additionally, we observe shear-induced migration of active suspensions and consider its impact on the resulting effective shear viscosity.

  8. Marine edible algae as disease preventers.

    PubMed

    Gomez-Gutierrez, Claudia Mariana; Guerra-Rivas, Graciela; Soria-Mercado, Ima Esthela; Ayala-Snchez, Nahara Ernestina

    2011-01-01

    As modern lifestyles and new feeding habits settle in the world, noncommunicable diseases (NCDs) have evolved to be major causes of disability in developing as well as developed countries. As a concomitant effect, there is a growing interest in natural, healthy food and an increasing awareness of risk factors and determinants of disease. This chapter describes some nutritional facts about seaweeds, which have been used as food since ancient times in China, Japan, Egypt, and India and comments on the potential utilization of marine algae as functional foods. This concept and the description of metabolic syndrome are used as a basis to comprehension of seaweeds against two dreadful illnesses of our times: high blood pressure and cancer. PMID:22054936

  9. Chloroplast Phylogenomic Inference of Green Algae Relationships

    PubMed Central

    Sun, Linhua; Fang, Ling; Zhang, Zhenhua; Chang, Xin; Penny, David; Zhong, Bojian

    2016-01-01

    The green algal phylum Chlorophyta has six diverse classes, but the phylogenetic relationship of the classes within Chlorophyta remains uncertain. In order to better understand the ancient Chlorophyta evolution, we have applied a site pattern sorting method to study compositional heterogeneity and the model fit in the green algal chloroplast genomic data. We show that the fastest-evolving sites are significantly correlated with among-site compositional heterogeneity, and these sites have a much poorer fit to the evolutionary model. Our phylogenomic analyses suggest that the class Chlorophyceae is a monophyletic group, and the classes Ulvophyceae, Trebouxiophyceae and Prasinophyceae are non-monophyletic groups. Our proposed phylogenetic tree of Chlorophyta will offer new insights to investigate ancient green algae evolution, and our analytical framework will provide a useful approach for evaluating and mitigating the potential errors of phylogenomic inferences. PMID:26846729

  10. Chloroplast Phylogenomic Inference of Green Algae Relationships.

    PubMed

    Sun, Linhua; Fang, Ling; Zhang, Zhenhua; Chang, Xin; Penny, David; Zhong, Bojian

    2016-01-01

    The green algal phylum Chlorophyta has six diverse classes, but the phylogenetic relationship of the classes within Chlorophyta remains uncertain. In order to better understand the ancient Chlorophyta evolution, we have applied a site pattern sorting method to study compositional heterogeneity and the model fit in the green algal chloroplast genomic data. We show that the fastest-evolving sites are significantly correlated with among-site compositional heterogeneity, and these sites have a much poorer fit to the evolutionary model. Our phylogenomic analyses suggest that the class Chlorophyceae is a monophyletic group, and the classes Ulvophyceae, Trebouxiophyceae and Prasinophyceae are non-monophyletic groups. Our proposed phylogenetic tree of Chlorophyta will offer new insights to investigate ancient green algae evolution, and our analytical framework will provide a useful approach for evaluating and mitigating the potential errors of phylogenomic inferences. PMID:26846729

  11. An algae-covered alligator rests warily

    NASA Technical Reports Server (NTRS)

    2000-01-01

    An algae-covered alligator keeps a wary eye open as it rests in one of the ponds at Kennedy Space Center. American alligators feed and rest in the water, and lay their eggs in dens they dig into the banks. The young alligators spend their first several weeks in these dens. The Center shares a boundary with the Merritt Island National Wildlife Refuge, which encompasses 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects.

  12. Polysaccharide nanofiber made from euglenoid alga.

    PubMed

    Shibakami, Motonari; Tsubouchi, Gen; Nakamura, Makoto; Hayashi, Masahiro

    2013-04-01

    We have fabricated a polysaccharide nanofiber made from paramylon (β-1,3-glucan), a storage polysaccharide stored as a micrometer-sized particle in the cell of euglenoid alga. Preparation of this nanofiber primarily hinges on the bottom-up approach. First, paramylon, which is originally present in the form of a bundle of nanofibers in a particle, was fibrillated to a randomly coiled polymer by dissolving the particle in a 1.0-mol/L NaOH aqueous solution. Second, the randomly coiled polymer was allowed to self-assemble into a triplex as the NaOH concentration was reduced to 0.25-0.20mol/L. Third, a 20-nm-width nanofiber made from the triplex emerged in the solution when the NaOH concentration was reduced to approximately 0.20mol/L. PMID:23499089

  13. Steroids from green alga Chaetomorpha basiretorsa Setchell

    NASA Astrophysics Data System (ADS)

    Shi, Dayong; Fan, Xiao; Sun, Jie; Han, Lijun; Shi, Jiangong

    2008-11-01

    Six steroids have been isolated from ethanolic extract of green alga Chaetomorpha basiretorsa Setchell by a combination of repeated normal phase silica gel and Sephadex LH-20 gel column chromatography as well as recrystallization. Using spectroscopic methods including MS and NMR, their structures were determined as β-lawsaritol (1), saringosterol (2), 24-hydroperoxy-24-vinyl-cholesterol (3), β-stigmasterol (4), stigmast-4-en-3α, 6β-diol (5), 29-hydroxystigmasta-5, 24 (28)-dien-3β-ol (6). All these compounds were obtained from this genus for the first time and they were inactive (IC50>10 μg /ml) against KB, Bel-7402, PC-3M, Ketr 3 and MCF-7 cell lines.

  14. Random flow induced by swimming algae

    NASA Astrophysics Data System (ADS)

    Kantsler, Vasily; Rushkin, Ilia; Goldstein, Raymond

    2010-11-01

    In this work we studied the random flow induced in a fluid by the motion of a dilute suspension of the swimming algae Volvox carteri. The fluid velocity in the suspension is a superposition of the flow fields set up by the individual organisms, which in turn have multipole contributions that decay as inverse powers of distance from the organism. Here we show that the conditions under which the central limit theorem guarantees a Gaussian probability distribution function of velocity fluctuations are satisfied when the leading force singularity is a Stokeslet. Deviations from Gaussianity are shown to arise from near-field effects. Comparison is made with the statistical properties of abiotic sedimenting suspensions. The experimental results are supplemented by extensive numerical studies.

  15. Granular activated algae for wastewater treatment.

    PubMed

    Tiron, O; Bumbac, C; Patroescu, I V; Badescu, V R; Postolache, C

    2015-01-01

    The study used activated algae granules for low-strength wastewater treatment in sequential batch mode. Each treatment cycle was conducted within 24 h in a bioreactor exposed to 235 μmol/m²/s light intensity. Wastewater treatment was performed mostly in aerobic conditions, oxygen being provided by microalgae. High removal efficiency of chemical oxygen demand (COD) was achieved (86-98%) in the first hours of the reaction phase, during which the indicator's removal rate was 17.4 ± 3.9 mg O₂/g h; NH(4)(+) was removed during organic matter degradation processes with a rate of 1.8 ± 0.6 mg/g h. After almost complete COD removal, the (O⁺) remaining in the liquor was removed through nitrification processes promoted by the increase of the liquor's oxygen saturation (O₂%), the transformation rate of NH4(+) into NO(3)(-) increasing from 0.14 ± 0.05 to 1.5 ± 0.4 mg NH4(+)/g h, along with an O₂% increase. A wide removal efficiency was achieved in the case of PO(4)(3)(-) (11-85%), with the indicator's removal rate being 1.3 ± 0.7 mg/g h. In the provided optimum conditions, the occurrence of the denitrifying activity was also noticed. A large pH variation was registered (5-8.5) during treatment cycles. The granular activated algae system proved to be a promising alternative for wastewater treatment as it also sustains cost-efficient microalgae harvesting, with microalgae recovery efficiency ranging between 99.85 and 99.99% after granules settling with a velocity of 19 ± 3.6 m/h. PMID:25812091

  16. Biomass of algae growth on natural water medium.

    PubMed

    Ramaraj, Rameshprabu; Tsai, David Dah-Wei; Chen, Paris Honglay

    2015-01-01

    Algae are the dominant primary producers in aquatic ecosystems. Since algae are highly varied group organisms, which have important functions in ecosystem, and their biomass is an essential biological resource. Currently, algae have been applied increasingly to diverse range of biomass applications. Therefore, this study was aimed to investigate the ecological algae features of microalgal production by natural medium, ecological function by lab scale of the symbiotic reactor which is imitated nature ecosystem, and atmospheric CO2 absorption that was related the algal growth of biomass to understand algae in natural water body better. Consequently, this study took advantages of using the unsupplemented freshwater natural medium to produce microalgae. Algal biomass by direct measurement of total suspended solids (TSS) and volatile suspended solids (VSS) resulted as 0.14g/L and 0.08g/L respectively. The biomass measurements of TSS and VSS are the sensible biomass index for algae production. The laboratory results obtained in the present study proved the production of algae by the natural water medium is potentially feasible. PMID:25531025

  17. Isoprenoid biosynthesis in eukaryotic phototrophs: A spotlight on algae

    SciTech Connect

    Lohr M.; Schwender J.; Polle, J. E. W.

    2012-04-01

    Isoprenoids are one of the largest groups of natural compounds and have a variety of important functions in the primary metabolism of land plants and algae. In recent years, our understanding of the numerous facets of isoprenoid metabolism in land plants has been rapidly increasing, while knowledge on the metabolic network of isoprenoids in algae still lags behind. Here, current views on the biochemistry and genetics of the core isoprenoid metabolism in land plants and in the major algal phyla are compared and some of the most pressing open questions are highlighted. Based on the different evolutionary histories of the various groups of eukaryotic phototrophs, we discuss the distribution and regulation of the mevalonate (MVA) and the methylerythritol phosphate (MEP) pathways in land plants and algae and the potential consequences of the loss of the MVA pathway in groups such as the green algae. For the prenyltransferases, serving as gatekeepers to the various branches of terpenoid biosynthesis in land plants and algae, we explore the minimal inventory necessary for the formation of primary isoprenoids and present a preliminary analysis of their occurrence and phylogeny in algae with primary and secondary plastids. The review concludes with some perspectives on genetic engineering of the isoprenoid metabolism in algae.

  18. Algae biomass cultivation in nitrogen rich biogas digestate.

    PubMed

    Krustok, I; Diaz, J G; Odlare, M; Nehrenheim, E

    2015-01-01

    Because microalgae are known for quick biomass growth and nutrient uptake, there has been much interest in their use in research on wastewater treatment methods. While many studies have concentrated on the algal treatment of wastewaters with low to medium ammonium concentrations, there are several liquid waste streams with high ammonium concentrations that microalgae could potentially treat. The aim of this paper was to test ammonium tolerance of the indigenous algae community of Lake Mlaren and to use this mixed consortia of algae to remove nutrients from biogas digestate. Algae from Lake Mlaren were cultivated in Jaworski's Medium containing a range of ammonium concentrations and the resulting algal growth was determined. The algae were able to grow at NH4-N concentrations of up to 200 mg L(-1) after which there was significant inhibition. To test the effectiveness of the lake water algae on the treatment of biogas digestate, different pre-cultivation set-ups and biogas digestate concentrations were tested. It was determined that mixing pre-cultivated suspension algae with 25% of biogas digestate by volume, resulting in an ammonium concentration of around 300 mg L(-1), produced the highest algal growth. The algae were effective in removing 72.82.2% of NH4-N and 41.441.4% of PO4-P. PMID:26540532

  19. Photophysiology and cellular composition of sea ice algae

    SciTech Connect

    Lizotte, M.P.

    1989-01-01

    The productivity of sea ice algae depends on their physiological capabilities and the environmental conditions within various microhabitats. Pack ice is the dominant form of sea ice, but the photosynthetic activity of associated algae has rarely been studied. Biomass and photosynthetic rates of ice algae of the Weddell-Scotia Sea were investigated during autumn and winter, the period when ice cover grows from its minimum to maximum. Biomass-specific photosynthetic rates typically ranged from 0.3 to 3.0 {mu}g C {center dot} {mu}g chl{sup {minus}1} {center dot} h{sup {minus}1} higher than land-fast ice algae but similar to Antarctic phytoplankton. Primary production in the pack ice during winter may be minor compared to annual phytoplankton production, but could represent a vital seasonal contribution to the Antarctic ecosystem. Nutrient supply may limit the productivity of ice algae. In McMurdo Sound, congelation ice algae appeared to be more nutrient deficient than underlying platelet ice algae based on: lower nitrogen:carbon, chlorophyll:carbon, and protein:carbohydrate; and {sup 14}C-photosynthate distribution to proteins and phospholipids was lower, while distribution to polysaccharides and neutral lipids was higher. Depletion of nitrate led to decreased nitrogen:carbon, chlorophyll:carbon, protein:carbohydrate, and {sup 14}C-photosynthate to proteins. Studied were conducted during the spring bloom; therefore, nutrient limitation may only apply to dense ice algal communities. Growth limiting conditions may be alleviated when algae are released into seawater during the seasonal recession of the ice cover. To continue growth, algae must adapt to the variable light field encountered in a mixed water column. Photoadaptation was studied in surface ice communities and in bottom ice communities.

  20. Photobiological hydrogen production with switchable photosystem-II designer algae

    DOEpatents

    Lee, James Weifu

    2014-02-18

    A process for enhanced photobiological H.sub.2 production using transgenic alga. The process includes inducing exogenous genes in a transgenic alga by manipulating selected environmental factors. In one embodiment inducing production of an exogenous gene uncouples H.sub.2 production from existing mechanisms that would downregulate H.sub.2 production in the absence of the exogenous gene. In other embodiments inducing an exogenous gene triggers a cascade of metabolic changes that increase H.sub.2 production. In some embodiments the transgenic alga are rendered non-regenerative by inducing exogenous transgenes for proton channel polypeptides that are targeted to specific algal membranes.

  1. Viable green algae and cyanobacteria within terrestrial permafrost

    NASA Astrophysics Data System (ADS)

    Vishnivetskaya, Tatiana A.; Vorobyova, Elena A.; Gilichinsky, David A.

    2002-11-01

    Viable permafrost algae have preserved their morphological characteristics and photosynthetic apparatus for the longest documented period of time on Earth. Unicellular green algae of the order Chlorococcales and filamentous cyanobacteria of the orders Oscillatoriales and Nostocales were isolated from deep subsurface permafrost sediments. Both were discovered within Siberian permafrost from the Holocene up to the Early Pleistocene age. However, green algae were found to be predominant and also able to survive inside colder Antarctic sediments. These findings will have an important impact on astrobiology and the study of organisms that exist in extreme environments.

  2. PRELIMINARY SURVEY OF FUNGISTATIC PROPERTIES OF MARINE ALGAE

    PubMed Central

    Welch, Ann Marie

    1962-01-01

    Welch, Ann Marie (U. S. Veterans Administration Hospital, Durham, N. C.). Preliminary survey of fungistatic properties of marine algae. J. Bacteriol. 83:97–99. 1962—Homogenized preparations of 35 marine algae were tested for inhibitory activity against 6 pathogenic or opportunistically pathogenic fungi with saturated filter-paper discs on seeded Sabouraud agar plates; 11 of these preparations produced wide zones of inhibition against 1 or more test organisms, and at least 4 of the 11 are considered to be worthy of further study. The results indicated that further search should be made for antifungal substances from marine algae. PMID:14005960

  3. EXTRACTION OF SUGARS FROM ALGAE FOR DIRECT CONVERSION TO BUTANOL

    EPA Science Inventory

    We will have a complete full scale design at the end of this project including algae growth and butanol production. Further, the group will have a working prototype for display at the National Mall.

  4. Bicarbonate produced from carbon capture for algae culture.

    PubMed

    Chi, Zhanyou; O'Fallon, James V; Chen, Shulin

    2011-11-01

    Using captured CO(2) to grow microalgae is limited by the high cost of CO(2) capture and transportation, as well as significant CO(2) loss during algae culture. Moreover, algae grow poorly at night, but CO(2) cannot be temporarily stored until sunrise. To address these challenges, we discuss a process where CO(2) is captured as bicarbonate and used as feedstock for algae culture, and the carbonate regenerated by the culture process is used as an absorbent to capture more CO(2). This process would significantly reduce carbon capture costs because it does not require additional energy for carbonate regeneration. Furthermore, not only would transport of the aqueous bicarbonate solution cost less than for that of compressed CO(2), but using bicarbonate would also provide a superior alternative for CO(2) delivery to an algae culture system. PMID:21775005

  5. Potential pharmacological applications of polyphenolic derivatives from marine brown algae.

    PubMed

    Thomas, Noel Vinay; Kim, Se-Kwon

    2011-11-01

    Recently, the isolation and characterization of the biologically active components from seaweeds have gained much attention from various research groups across the world. The marine algae have been studied for biologically active components and phlorotannins are one among them. Among marine algae, brown algal species such as Ecklonia cava, Eisenia arborea, Ecklonia stolinifera and Eisenia bicyclis have been studied for their potential biological activities. Majority of the investigations on phlorotannins derived from brown algae have exhibited their potentiality as antioxidant, anti-inflammatory, antidiabetic, antitumor, antihypertensive, anti-allergic, hyaluronidase enzyme inhibition and in matrix metalloproteinases (MMPs) inhibition activity. In this review, we have made an attempt to discuss the potential biological activities of phlorotannins from marine brown algae and their possible candidature in the pharmaceutical applications. PMID:22004951

  6. Harmful algae blooms removal from fresh water with modified vermiculite.

    PubMed

    Miao, Chunguang; Tang, Yi; Zhang, Hong; Wu, Zhengyan; Wang, Xiangqin

    2014-01-01

    Vermiculite and vermiculite modified with hydrochloric acid were investigated to evaluate their flocculation efficiencies in freshwater containing harmful algae blooms (HABs) (Microcystis aeruginosa). Scanning electron microscope, Fourier transform infrared spectroscopy, X-ray diffraction, converted fluorescence microscope, plasma-atomic emission spectrometry, and Zetasizer were used to study the flocculation mechanism of modified vermiculite. It was found that the vermiculite modified with hydrochloric acid could coagulate algae cells through charge neutralization, chemical bridging, and netting effect. The experimental results show that the efficiency of flocculation can be notably improved by modified vermiculite. Ninety-eight per cent of algae cells in algae solution could be removed within 10 min after the addition ofmodified vermiculite clay. The method that removal of HABs with modified vermiculite is economical with high efficiency, and more research is needed to assess their ecological impacts before using in practical application. PMID:24600873

  7. Colourful Cultures: Classroom Experiments with the Unicellular Alga Haematococcus pluvialis.

    ERIC Educational Resources Information Center

    Delpech, Roger

    2001-01-01

    Describes an investigation into the photosynthetic potential of the different developmental stages of the green unicellular alga Haematococcus pluvialis. Reviews the biotechnological applications of astaxanthin, the red pigment which can be extracted from Haematococcus pluvialis. (Author/MM)

  8. ENDOTOXINS, ALGAE AND 'LIMULUS' AMOEBOCYTE LYSATE TEST IN DRINKING WATER

    EPA Science Inventory

    Field and laboratory studies were conducted to determine the distribution of algae and bacteria, and investigate sources of endotoxins (lipopolysaccharides) in drinking water. The field survey was performed on five drinking water systems located in Allegheny County, Pennsylvania ...

  9. CONTROL TECHNOLOGY EXTRACTION OF MERCURY FROM GROUNDWATER IMMOBILIZED ALGAE

    EPA Science Inventory

    Bio-Recovery Systems, Inc. conducted a project under the Emerging Technology portion of the United States Environmental Protection Agency (EPAs) Superfund Innovative Technology Evaluation (SITE) Program to evaluate the ability of immobilized algae to adsorb mercury from contamina...

  10. Application of synthetic biology in cyanobacteria and algae

    PubMed Central

    Wang, Bo; Wang, Jiangxin; Zhang, Weiwen; Meldrum, Deirdre R.

    2012-01-01

    Cyanobacteria and algae are becoming increasingly attractive cell factories for producing renewable biofuels and chemicals due to their ability to capture solar energy and CO2 and their relatively simple genetic background for genetic manipulation. Increasing research efforts from the synthetic biology approach have been made in recent years to modify cyanobacteria and algae for various biotechnological applications. In this article, we critically review recent progresses in developing genetic tools for characterizing or manipulating cyanobacteria and algae, the applications of genetically modified strains for synthesizing renewable products such as biofuels and chemicals. In addition, the emergent challenges in the development and application of synthetic biology for cyanobacteria and algae are also discussed. PMID:23049529

  11. ALGAE AND CRUSTACEANS AS INDICATORS OF BIOACTIVITY OF INDUSTRIAL WASTES

    EPA Science Inventory

    Freshwater (Selenastrum capricornutum) and estuarine (Skeketonema costatum) algae were exposed to liquid wastes from 10 industrial sites in laboratory bioassays. All wastes affected algal growth either by stimulation or by stimulation at low concentrations and inhibition at high ...

  12. Algae Reefs in Shark Bay, Western Australia, Australia

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Numerous algae reefs are seen in Shark Bay, Western Australia, Australia (26.0S, 113.5E) especially in the southern portions of the bay. The south end is more saline because tidal flow in and out of the bay is restricted by sediment deposited at the north and central end of the bay opposite the mouth of the Wooramel River. This extremely arid region produces little sediment runoff so that the waters are very clear, saline and rich in algae.

  13. Radionuclides and trace metals in eastern Mediterranean Sea algae.

    PubMed

    Al-Masri, M S; Mamish, S; Budier, Y

    2003-01-01

    Three types of sea alga distributed along the Syrian coast have been collected and analyzed for radioactivity and trace elements. Results have shown that (137)Cs concentrations in all the analyzed sample were relatively low (less than 1.2 Bq kg(-1) dry weight) while the levels of naturally occurring radionuclides, such as (210)Po and (210)Pb, were found to be high in most samples; the highest observed value (27.43 Bq kg(-1) dry weight) for (210)Po being in the red Jania longifurca alga. In addition, most brown alga species were also found to accumulate (210)Po, which indicates their selectivity to this isotope. On the other hand, brown alga (Cystoseira and Sargassum Vulgare) have shown a clear selectivity for some trace metals such as Cr, As, Cu and Co, this selectivity may encourage their use as biomonitor for pollution by trace metals. Moreover, the red alga species were found to contain the highest levels of Mg while the brown alga species were found to concentrate Fe, Mn, Na and K and nonmetals such as Cl, I and Br. PMID:12660047

  14. An overview of algae biofuel production and potential environmental impact.

    PubMed

    Menetrez, Marc Y

    2012-07-01

    Algae are among the most potentially significant sources of sustainable biofuels in the future of renewable energy. A feedstock with virtually unlimited applicability, algae can metabolize various waste streams (e.g., municipal wastewater, carbon dioxide from industrial flue gas) and produce products with a wide variety of compositions and uses. These products include lipids, which can be processed into biodiesel; carbohydrates, which can be processed into ethanol; and proteins, which can be used for human and animal consumption. Algae are commonly genetically engineered to allow for advantageous process modification or optimization. However, issues remain regarding human exposure to algae-derived toxins, allergens, and carcinogens from both existing and genetically modified organisms (GMOs), as well as the overall environmental impact of GMOs. A literature review was performed to highlight issues related to the growth and use of algal products for generating biofuels. Human exposure and environmental impact issues are identified and discussed, as well as current research and development activities of academic, commercial, and governmental groups. It is hoped that the ideas contained in this paper will increase environmental awareness of issues surrounding the production of algae and will help the algae industry develop to its full potential. PMID:22681590

  15. Feeding preferences of mesograzers on aquacultured Gracilaria and sympatric algae

    PubMed Central

    Cruz-Rivera, Edwin; Friedlander, Michael

    2011-01-01

    While large grazers can often be excluded effectively from algal aquaculture operations, smaller herbivores such as small crustaceans and gastropods may be more difficult to control. The susceptibility of three Gracilaria species to herbivores was evaluated in multiple-choice experiments with the amphipod Ampithoe ramondi and the crab Acanthonyx lunulatus. Both mesograzers are common along the Mediterranean coast of Israel. When given a choice, the amphipod preferred to consume Gracilaria lemaneiformis significantly more than either G. conferta or G. cornea. The crab, however, consumed equivalent amounts of G. lemaneiformis and G. conferta, but did not consume G. cornea. Organic content of these algae, an important feeding cue for some mesograzers, could not account for these differences. We further assessed the susceptibility of a candidate species for aquaculture, G. lemaneiformis, against local algae, including common epiphytes. When given a choice of four algae, amphipods preferred the green alga Ulva lactuca over Jania rubens. However, consumption of U. lactuca was equivalent to those of G. lemaneiformis and Padina pavonica. In contrast, the crab showed a marked and significant preference for G. lemaneiformis above any of the other three algae offered. Our results suggest that G. cornea is more resistant to herbivory from common mesograzers and that, contrary to expectations, mixed cultures or epiphyte growth on G. lemaneiformis cannot reduce damage to this commercially appealing alga if small herbivores are capable of recruiting into culture ponds. Mixed cultures may be beneficial when culturing other Gracilaria species. PMID:22711945

  16. Study on algae removal by immobilized biosystem on sponge

    NASA Astrophysics Data System (ADS)

    Pei, Haiyan; Hu, Wenrong

    2006-10-01

    In this study, sponges were used to immobilize domesticated sludge microbes in a limited space, forming an immobilized biosystem capable of algae and microcystins removal. The removal effects on algae, microcystins and UV260 of this biosystem and the mechanism of algae removal were studied. The results showed that active sludge from sewage treatment plants was able to remove algae from a eutrophic lake’s water after 7 d of domestication. The removal efficiency for algae, organic matter and microcystins increased when the domesticated sludge was immobilized on sponges. When the hydraulic retention time (HRT) was 5h, the removal rates of algae, microcystins and UV260 were 90%, 94.17% and 84%, respectively. The immobilized biosystem consisted mostly of bacteria, the Ciliata and Sarcodina protozoans and the Rotifer metazoans. Algal decomposition by zoogloea bacteria and preying by microcreatures were the two main modes of algal removal, which occurred in two steps: first, absorption by the zoogloea; second, decomposition by the zoogloea bacteria and the predacity of the microcreatures.

  17. Development of Green Fuels From Algae - The University of Tulsa

    SciTech Connect

    Crunkleton, Daniel; Price, Geoffrey; Johannes, Tyler; Cremaschi, Selen

    2012-12-03

    The general public has become increasingly aware of the pitfalls encountered with the continued reliance on fossil fuels in the industrialized world. In response, the scientific community is in the process of developing non-fossil fuel technologies that can supply adequate energy while also being environmentally friendly. In this project, we concentrate on “green fuels” which we define as those capable of being produced from renewable and sustainable resources in a way that is compatible with the current transportation fuel infrastructure. One route to green fuels that has received relatively little attention begins with algae as a feedstock. Algae are a diverse group of aquatic, photosynthetic organisms, generally categorized as either macroalgae (i.e. seaweed) or microalgae. Microalgae constitute a spectacularly diverse group of prokaryotic and eukaryotic unicellular organisms and account for approximately 50% of global organic carbon fixation. The PI’s have subdivided the proposed research program into three main research areas, all of which are essential to the development of commercially viable algae fuels compatible with current energy infrastructure. In the fuel development focus, catalytic cracking reactions of algae oils is optimized. In the species development project, genetic engineering is used to create microalgae strains that are capable of high-level hydrocarbon production. For the modeling effort, the construction of multi-scaled models of algae production was prioritized, including integrating small-scale hydrodynamic models of algae production and reactor design and large-scale design optimization models.

  18. Modelling the effect of fluctuating herbicide concentrations on algae growth.

    PubMed

    Copin, Pierre-Jean; Coutu, Sylvain; Chvre, Nathalie

    2015-03-01

    Herbicide concentrations fluctuate widely in watercourses after crop applications and rain events. The level of concentrations in pulses can exceed the water chronic quality criteria. In the present study, we proposed modelling the effects of successive pulse exposure on algae. The deterministic model proposed is based on two parameters: (i) the typical growth rate of the algae, obtained by monitoring growth rates of several successive batch cultures in growth media, characterizing both the growth of the control and during the recovery periods; (ii) the growth rate of the algae exposed to pulses, determined from a dose-response curve obtained with a standard toxicity test. We focused on the herbicide isoproturon and on the freshwater alga Scenedesmus vacuolatus, and we validated the model prediction based on effect measured during five sequential pulse exposures in laboratory. The comparison between the laboratory and the modelled effects illustrated that the results yielded were consistent, making the model suitable for effect prediction of the herbicide photosystem II inhibitor isoproturon on the alga S. vacuolatus. More generally, modelling showed that both pulse duration and level of concentration play a crucial role. The application of the model to a real case demonstrated that both the highest peaks and the low peaks with a long duration affect principally the cell density inhibition of the alga S. vacuolatus. It is therefore essential to detect these characteristic pulses when monitoring of herbicide concentrations are conducted in rivers. PMID:25499055

  19. Mixotrophy in red tide algae raphidophytes.

    PubMed

    Jeong, Hae Jin

    2011-01-01

    Marine raphidophytes are common red tide organisms that are distributed worldwide. They are known to be harmful to other plankton and fish and have often caused large-scale fish mortality in many countries. Thus, the population dynamics of raphidophytes is a critical concern for scientists, the aquaculture industry, and government officers from many countries. Raphidophyte growth and mortality should be investigated to understand bloom dynamics. Raphidophytes were thought to be exclusively autotrophic organisms. However, several recent studies have revealed that raphidophytes are able to feed on heterotrophic and autotrophic bacteria, i.e. raphidophytes are mixotrophic algae. Further, high-resolution video microscopy has revealed the mechanism by which raphidophytes feed on bacteria, which involves capturing prey cells in the mucus excreted by mucocysts and engulfing the cells through mucocysts. These discoveries may influence the conventional view on both raphidophyte bloom dynamics and plankton energy flow and carbon cycling. In the present study, I review prey, feeding mechanisms, and ingestion rates of mixotrophic marine raphidophytes. In addition, I examine the ecological significance of raphidophyte mixotrophy. PMID:21518079

  20. Is the Future Really in Algae?

    NASA Technical Reports Server (NTRS)

    Trent, Jonathan

    2011-01-01

    Having just emerged from the warmest decade on record and watching as the oceans acidify, global resources peak, the world's population continues to climb, and nearly half of all known species face extinction by the end of the century. We stand on the threshold of one of the most important transition in human history-the transition from hunting-and-gathering our energy to cultivating sustainable, carbon-neutral, environmentally-friendly energy supplies. Can we "cultivate" enerm without competing with agriculture for land, freshwater, or fertilizer? Can we develop an "ecology of technology" that optimizes our use of limited resources? Is human activity compatible with improved conditions in the world's oceans? Will our ingenuity prevail in time to make a difference for our children and the children of all species? With support from NASA ARMD and the California Energy Commission, a group of dedicated scientists and engineers are working on a project called OMEGA (Offshore Membrane Enclosures for Growing Algae), to provide practical answers to these critical questions and to leave a legacy of hope for the oceans and for the future.

  1. Comparative Transcriptome Analysis of Four Prymnesiophyte Algae

    PubMed Central

    Koid, Amy E.; Liu, Zhenfeng; Terrado, Ramon; Jones, Adriane C.; Caron, David A.; Heidelberg, Karla B.

    2014-01-01

    Genomic studies of bacteria, archaea and viruses have provided insights into the microbial world by unveiling potential functional capabilities and molecular pathways. However, the rate of discovery has been slower among microbial eukaryotes, whose genomes are larger and more complex. Transcriptomic approaches provide a cost-effective alternative for examining genetic potential and physiological responses of microbial eukaryotes to environmental stimuli. In this study, we generated and compared the transcriptomes of four globally-distributed, bloom-forming prymnesiophyte algae: Prymnesium parvum, Chrysochromulina brevifilum, Chrysochromulina ericina and Phaeocystis antarctica. Our results revealed that the four transcriptomes possess a set of core genes that are similar in number and shared across all four organisms. The functional classifications of these core genes using the euKaryotic Orthologous Genes (KOG) database were also similar among the four study organisms. More broadly, when the frequencies of different cellular and physiological functions were compared with other protists, the species clustered by both phylogeny and nutritional modes. Thus, these clustering patterns provide insight into genomic factors relating to both evolutionary relationships as well as trophic ecology. This paper provides a novel comparative analysis of the transcriptomes of ecologically important and closely related prymnesiophyte protists and advances an emerging field of study that uses transcriptomics to reveal ecology and function in protists. PMID:24926657

  2. [The effects of blue algae on health].

    PubMed

    van Riel, A J H P; Schets, F M; Meulenbelt, J

    2007-08-01

    Cyanobacteria (blue algae) regularly cause recreational waters to become murky and smelly. Skin irritation and mild gastrointestinal disorders have regularly been reported following recreational activities in water suspected of being contaminated with cyanobacteria. The exact cause of these effects on health is not clear. Severe effects are not to be expected from recreational exposure to water contaminated with cyanobacteria. Cyanobacteria can produce hepatotoxins, neurotoxins, cytotoxins and irritants. In Brazil lethal intoxications have occurred due to the occurrence of toxins in drinking water and in dialysis fluid. The Dutch policy is based on the Commissie Integraal Waterbeheer (Commission Integral Water Management) guidelines for recreational waters. It is not clear to what extent the other cyanotoxins occur in the Netherlands. However, several genera ofcyanobacteria capable of producing these other cyanotoxins have been found in the Netherlands. For a good risk assessment in the Netherlands, more information is needed on the effects on health of cyanobacteria. There is also a need for more data on the prevalence of different cyanobacteria and toxins in Dutch recreational waters. PMID:17784694

  3. [Toxicity of Coptis chinensis Rhizome Extracts to Green Algae].

    PubMed

    Chen, Ya-nan; Yuan, Ling

    2015-05-01

    Coptis chinensis contains antiseptic alkaloids and thus its rhizomes and preparations are widely used for the treatment of.fish diseases. In order to realize the risk of water ecosystems produced by this medical herb and preparations used in aquaculture, the present experiment was carried out to study the toxicity of Coptis chinensis rhizome extract (CRE) to Scenedesmus oblique and Chlorella pyrenoidosa grown in culture solution with 0.00 (CK), 0.088 (Tl), 0.44 (T2) and 1.76 mg L(-1) (T3) of CRE, respectively. The results show that low concentration of CRE (T1) inhibited the growth rate of the alga and high CRE (T2 and T3) ceased growth and reproductions. CRE also decreased the chlorophyll and proteins in alga cells, indicating the inhibition of photosynthesis and protein biosynthesis, which could be direct reasons for the low growth rate and death of green alga. The efflux of protons and substances from alga cells led to pH reduction and conductivity increment in culture solution with CRE. Furthermore, the activity of superoxide dismutase in alga increased at the beginning of CRE in T1 and T2 treatments but decreased as time prolonged which was in contrast to high CRE treatment. And the long exposure to low CRE treatment behaved otherwise. This suggests that the low concentration of CRE could induce the resistant reactions in alga at initial time but high CRE concentration or long exposure even at low CRE concentration could inhibit the enzyme synthesis. Similarly, malondialdehyde in alga increased as CRE concentrations increased in culture solutions, implying the damage and high permeability of cell membrane. In general, Chlorella pyrenoidosa was more sensitive to CRE. The abuse of rhizomes and preparations in aquaculture and intensive cultivation of Coptis chinensis plants in a large scale might produce ecological risks to primary productivity of water ecosystems. PMID:26314112

  4. Plasticity predicts evolution in a marine alga

    PubMed Central

    Schaum, C. Elisa; Collins, Sinéad

    2014-01-01

    Under global change, populations have four possible responses: ‘migrate, acclimate, adapt or die’ (Gienapp et al. 2008 Climate change and evolution: disentangling environmental and genetic response. Mol. Ecol. 17, 167–178. (doi:10.1111/j.1365-294X.2007.03413.x)). The challenge is to predict how much migration, acclimatization or adaptation populations are capable of. We have previously shown that populations from more variable environments are more plastic (Schaum et al. 2013 Variation in plastic responses of a globally distributed picoplankton species to ocean acidification. Nature 3, 298–230. (doi:10.1038/nclimate1774)), and here we use experimental evolution with a marine microbe to learn that plastic responses predict the extent of adaptation in the face of elevated partial pressure of CO2 (pCO2). Specifically, plastic populations evolve more, and plastic responses in traits other than growth can predict changes in growth in a marine microbe. The relationship between plasticity and evolution is strongest when populations evolve in fluctuating environments, which favour the evolution and maintenance of plasticity. Strikingly, plasticity predicts the extent, but not direction of phenotypic evolution. The plastic response to elevated pCO2 in green algae is to increase cell division rates, but the evolutionary response here is to decrease cell division rates over 400 generations until cells are dividing at the same rate their ancestors did in ambient CO2. Slow-growing cells have higher mitochondrial potential and withstand further environmental change better than faster growing cells. Based on this, we hypothesize that slow growth is adaptive under CO2 enrichment when associated with the production of higher quality daughter cells. PMID:25209938

  5. Plasticity predicts evolution in a marine alga.

    PubMed

    Schaum, C Elisa; Collins, Sinad

    2014-10-22

    Under global change, populations have four possible responses: 'migrate, acclimate, adapt or die' (Gienapp et al. 2008 Climate change and evolution: disentangling environmental and genetic response. Mol. Ecol. 17, 167-178. (doi:10.1111/j.1365-294X.2007.03413.x)). The challenge is to predict how much migration, acclimatization or adaptation populations are capable of. We have previously shown that populations from more variable environments are more plastic (Schaum et al. 2013 Variation in plastic responses of a globally distributed picoplankton species to ocean acidification. Nature 3, 298-230. (doi:10.1038/nclimate1774)), and here we use experimental evolution with a marine microbe to learn that plastic responses predict the extent of adaptation in the face of elevated partial pressure of CO2 (pCO2). Specifically, plastic populations evolve more, and plastic responses in traits other than growth can predict changes in growth in a marine microbe. The relationship between plasticity and evolution is strongest when populations evolve in fluctuating environments, which favour the evolution and maintenance of plasticity. Strikingly, plasticity predicts the extent, but not direction of phenotypic evolution. The plastic response to elevated pCO2 in green algae is to increase cell division rates, but the evolutionary response here is to decrease cell division rates over 400 generations until cells are dividing at the same rate their ancestors did in ambient CO2. Slow-growing cells have higher mitochondrial potential and withstand further environmental change better than faster growing cells. Based on this, we hypothesize that slow growth is adaptive under CO2 enrichment when associated with the production of higher quality daughter cells. PMID:25209938

  6. Method and apparatus using an active ionic liquid for algae biofuel harvest and extraction

    SciTech Connect

    Salvo, Roberto Di; Reich, Alton; Dykes, Jr., H. Waite H.; Teixeira, Rodrigo

    2012-11-06

    The invention relates to use of an active ionic liquid to dissolve algae cell walls. The ionic liquid is used to, in an energy efficient manner, dissolve and/or lyse an algae cell walls, which releases algae constituents used in the creation of energy, fuel, and/or cosmetic components. The ionic liquids include ionic salts having multiple charge centers, low, very low, and ultra low melting point ionic liquids, and combinations of ionic liquids. An algae treatment system is described, which processes wet algae in a lysing reactor, separates out algae constituent products, and optionally recovers the ionic liquid in an energy efficient manner.

  7. Influence of algae on photolysis rates of chemicals in water

    SciTech Connect

    Zepp, R.G.; Schlotzhauer, P.F.

    1983-08-01

    Sunlight-induced algal transformations of 22 nonionic organic chemicals were studied in order to provide kinetic results and equations concerning the influence of algae on the behavior of pollutants in freshwater environments. Screening studies indicated that green and blue-green algae, at concentrations of 1-10 mg of chlorophyll a/L, accelerate photoreaction of certain polycylic aromatic hydrocarbons, organophosphorus compounds, and anilines in water. The rate of change in aniline concentration, (P), in the aniline-Chlamydomonas photoreaction can be described by the following expression: rate = A(1 + B/(P))-1. At low substrate concentrations, the reaction rate is first order with respect to both algae and substrate concentration. Methyl parathion and parathion photoreacted 390 times more rapidly when sorbed by algae than in distilled water, and aniline and m-toluidine reacted over 12000 times faster, indicating that light-induced algal transformations of certain pollutants may be significant. Other results indicated that reaction rates are unaffected by heat-killing the algae. 27 references

  8. Sustainability of algae derived biodiesel: a mass balance approach.

    PubMed

    Pfromm, Peter H; Amanor-Boadu, Vincent; Nelson, Richard

    2011-01-01

    A rigorous chemical engineering mass balance/unit operations approach is applied here to bio-diesel from algae mass culture. An equivalent of 50,000,000 gallons per year (0.006002 m3/s) of petroleum-based Number 2 fuel oil (US, diesel for compression-ignition engines, about 0.1% of annual US consumption) from oleaginous algae is the target. Methyl algaeate and ethyl algaeate diesel can according to this analysis conceptually be produced largely in a technologically sustainable way albeit at a lower available diesel yield. About 11 square miles of algae ponds would be needed with optimistic assumptions of 50 g biomass yield per day and m2 pond area. CO2 to foster algae growth should be supplied from a sustainable source such as a biomass-based ethanol production. Reliance on fossil-based CO2 from power plants or fertilizer production renders algae diesel non-sustainable in the long term. PMID:20933402

  9. Application of algae-biosensor for environmental monitoring.

    PubMed

    Umar, Lazuardi; Alexander, Frank A; Wiest, Joachim

    2015-08-01

    Environmental problems including water and air pollution, over fertilization, insufficient wastewater treatment and even ecological disaster are receiving greater attention in the technical and scientific area. In this paper, a method for water quality monitoring using living green algae (Chlorella Kessleri) with the help of the intelligent mobile lab (IMOLA) is presented. This measurement used two IMOLA systems for measurement and reference simultaneously to verify changes due to pollution inside the measurement system. The IMOLA includes light emitting diodes to stimulate photosynthesis of the living algae immobilized on a biochip containing a dissolved oxygen microsensor. A fluid system is used to transport algae culture medium in a stop and go mode; 600s ON, 300s OFF, while the oxygen concentration of the water probe is measured. When the pump stops, the increase in dissolved oxygen concentration due to photosynthesis is detected. In case of a pollutant being transported toward the algae, this can be detected by monitoring the photosynthetic activity. Monitoring pollution is shown by adding emulsion of 0,5mL of Indonesian crude palm oil and 10mL algae medium to the water probe in the biosensor. PMID:26737928

  10. Evolution of reproductive development in the volvocine algae.

    PubMed

    Hallmann, Armin

    2011-06-01

    The evolution of multicellularity, the separation of germline cells from sterile somatic cells, and the generation of a male-female dichotomy are certainly among the greatest innovations of eukaryotes. Remarkably, phylogenetic analysis suggests that the shift from simple to complex, differentiated multicellularity was not a unique progression in the evolution of life, but in fact a quite frequent event. The spheroidal green alga Volvox and its close relatives, the volvocine algae, span the full range of organizational complexity, from unicellular and colonial genera to multicellular genera with a full germ-soma division of labor and male-female dichotomy; thus, these algae are ideal model organisms for addressing fundamental issues related to the transition to multicellularity and for discovering universal rules that characterize this transition. Of all living species, Volvox carteri represents the simplest version of an immortal germline producing specialized somatic cells. This cellular specialization involved the emergence of mortality and the production of the first dead ancestors in the evolution of this lineage. Volvocine algae therefore exemplify the evolution of cellular cooperation from cellular autonomy. They also serve as a prime example of the evolution of complex traits by a few successive, small steps. Thus, we learn from volvocine algae that the evolutionary transition to complex, multicellular life is probably much easier to achieve than is commonly believed. PMID:21174128

  11. Picoeucaryot alga infecting blue mussel Mytilus edulis in southern Norway.

    PubMed

    Mortensen, Stein; Harkestad, Lisbeth S; Stene, Rolf-Olav; Renault, Tristan

    2005-01-25

    During summer 2001, blue mussels Mytilus edulis with abnormal shell growth were collected near Krager, southern Norway. The mussels had green spots in their mantle tissues, mainly posteriorly and ventrally, and in the adductor muscle. Mussels from 4 sites had a prevalence of green spots varying from 2 to 71% that correlated well with shell deformities. Histological examination revealed the presence of round or ovoid algae, 0.9 to 1.5 x 1.2 to 2.4 microm, free within haemocytes and in the lesions, characterised by an inflammatory response and the presence of cellular debris. The alga contain a relatively large nucleus, 1 chloroplast and 1 mitochondrion. Size and morphology suggest that the alga might be a picoeucaryot green alga. Infection of mussel tissues appears to start in the posterior mantle edge, near the siphons, and spread anterior-ventrally in the mantle connective and storage tissues-occasionally spots were also found in the gonad follicles. Large infected areas were also observed in sinuses within the adductor muscle. Only mussels that were 3 yr old or more were infected. Deformations apparently resulted from years of continuous shell formation by a contracted, partly deformed mantle. Most deformed mussels had eroded shells, allowing some light penetration through the exposed, thin nacre. Young, thin-shelled mussels were not infected. The present work suggests that the alga has, at least partially, a parasitic relationship with the mussels, and is associated with pathological alterations in mussel tissues. PMID:15759797

  12. Anti-Phytopathogenic Activities of Macro-Algae Extracts

    PubMed Central

    Jiménez, Edra; Dorta, Fernando; Medina, Cristian; Ramírez, Alberto; Ramírez, Ingrid; Peña-Cortés, Hugo

    2011-01-01

    Aqueous and ethanolic extracts obtained from nine Chilean marine macro-algae collected at different seasons were examined in vitro and in vivo for properties that reduce the growth of plant pathogens or decrease the injury severity of plant foliar tissues following pathogen infection. Particular crude aqueous or organic extracts showed effects on the growth of pathogenic bacteria whereas others displayed important effects against pathogenic fungi or viruses, either by inhibiting fungal mycelia growth or by reducing the disease symptoms in leaves caused by pathogen challenge. Organic extracts obtained from the brown-alga Lessonia trabeculata inhibited bacterial growth and reduced both the number and size of the necrotic lesion in tomato leaves following infection with Botrytis cinerea. Aqueous and ethanolic extracts from the red-alga Gracillaria chilensis prevent the growth of Phytophthora cinnamomi, showing a response which depends on doses and collecting-time. Similarly, aqueous and ethanolic extracts from the brown-alga Durvillaea antarctica were able to diminish the damage caused by tobacco mosaic virus (TMV) in tobacco leaves, and the aqueous procedure is, in addition, more effective and seasonally independent. These results suggest that macro-algae contain compounds with different chemical properties which could be considered for controlling specific plant pathogens. PMID:21673886

  13. Mg-lattice associations in red coralline algae

    NASA Astrophysics Data System (ADS)

    Kamenos, N. A.; Cusack, M.,; Huthwelker, T.; Lagarde, P.; Scheibling, R. E.

    2009-04-01

    Recent investigations have shown red coralline algae to record ambient temperature in their calcite skeletons. Temperature recorded by variation in Mg concentrations within algal growth bands has sub-annual resolution and high accuracy. The conversion of Mg concentration to temperature is based on the assumption of Ca replacement by Mg within the algal calcite skeleton at higher temperatures. While Mg-temperature relationships in coralline algae have been calibrated for some species, the location of Mg within the calcite lattice remains unknown. Critically, if Mg is not a lattice component but associated with organic components this could lead to erroneous temperature records. Before coralline algae are used in large scale climate reconstructions it is therefore important to determine the location of Mg. Synchrotron Mg-X-ray absorbance near edge structure (XANES) indicates that Mg is associated with the calcite lattice in Lithothamnion glaciale (contemporary free-living, contemporary encrusting and sub-fossil free-living) and Phymatolithon calcareum (contemporary free-living) coralline algae. Mg is deposited within the calcite lattice in all seasons (L. glaciale & P. calcareum) and thallus areas (P. calcareum). These results suggest L. glaciale and P. calcareum are robust Mg-palaeotemperature proxies. We suggest that similar confirmation be obtained for Mg associations in other species of red coralline algae aiding our understanding of their role in climate reconstruction at large spatial scales.

  14. Mg-lattice associations in red coralline algae

    NASA Astrophysics Data System (ADS)

    Kamenos, N. A.; Cusack, M.; Huthwelker, T.; Lagarde, P.; Scheibling, R. E.

    2009-04-01

    Recent investigations have shown red coralline algae to record ambient temperature in their calcite skeletons. Temperature recorded by variation in Mg concentrations within algal growth bands has sub-annual resolution and high accuracy. The conversion of Mg concentration to temperature is based on the assumption of Ca replacement by Mg within the algal calcite skeleton at higher temperatures. While Mg-temperature relationships in coralline algae have been calibrated for some species, the location of Mg within the calcite lattice remains unknown. Critically, if Mg is not a lattice component but associated with organic components this could lead to erroneous temperature records. Before coralline algae are used in large scale climate reconstructions it is therefore important to determine the location of Mg. Synchrotron Mg-X-ray absorbance near edge structure (XANES) indicates that Mg is associated with the calcite lattice in Lithothamnion glaciale (contemporary free-living, contemporary encrusting and sub-fossil free-living) and Phymatolithon calcareum (contemporary free-living) coralline algae. Mg is deposited within the calcite lattice in all seasons ( L. glaciale & P. calcareum) and thallus areas ( P. calcareum). These results suggest L. glaciale and P. calcareum are robust Mg-palaeotemperature proxies. We suggest that similar confirmation be obtained for Mg associations in other species of red coralline algae aiding our understanding of their role in climate reconstruction at large spatial scales.

  15. Algae-bacteria interactions: Evolution, ecology and emerging applications.

    PubMed

    Ramanan, Rishiram; Kim, Byung-Hyuk; Cho, Dae-Hyun; Oh, Hee-Mock; Kim, Hee-Sik

    2016-01-01

    Algae and bacteria have coexisted ever since the early stages of evolution. This coevolution has revolutionized life on earth in many aspects. Algae and bacteria together influence ecosystems as varied as deep seas to lichens and represent all conceivable modes of interactions - from mutualism to parasitism. Several studies have shown that algae and bacteria synergistically affect each other's physiology and metabolism, a classic case being algae-roseobacter interaction. These interactions are ubiquitous and define the primary productivity in most ecosystems. In recent years, algae have received much attention for industrial exploitation but their interaction with bacteria is often considered a contamination during commercialization. A few recent studies have shown that bacteria not only enhance algal growth but also help in flocculation, both essential processes in algal biotechnology. Hence, there is a need to understand these interactions from an evolutionary and ecological standpoint, and integrate this understanding for industrial use. Here we reflect on the diversity of such relationships and their associated mechanisms, as well as the habitats that they mutually influence. This review also outlines the role of these interactions in key evolutionary events such as endosymbiosis, besides their ecological role in biogeochemical cycles. Finally, we focus on extending such studies on algal-bacterial interactions to various environmental and bio-technological applications. PMID:26657897

  16. Method to transform algae, materials therefor, and products produced thereby

    DOEpatents

    Dunahay, T.G.; Roessler, P.G.; Jarvis, E.E.

    1997-08-26

    Disclosed is a method to transform chlorophyll C-containing algae. The method includes introducing a recombinant molecule comprising a nucleic acid molecule encoding a dominant selectable marker operatively linked to an algal regulatory control sequence into a chlorophyll C-containing alga in such a manner that the marker is produced by the alga. In a preferred embodiment the algal regulatory control sequence is derived from a diatom and preferably Cyclotella cryptica. Also disclosed is a chimeric molecule having one or more regulatory control sequences derived from one or more chlorophyll C-containing algae operatively linked to a nucleic acid molecule encoding a selectable marker, an RNA molecule and/or a protein, wherein the nucleic acid molecule does not normally occur with one or more of the regulatory control sequences. Further, specifically disclosed are molecules pACCNPT10, pACCNPT4.8 and pACCNPT5.1. The methods and materials of the present invention provide the ability to accomplish stable genetic transformation of chlorophyll C-containing algae. 2 figs.

  17. Method to transform algae, materials therefor, and products produced thereby

    DOEpatents

    Dunahay, Terri Goodman; Roessler, Paul G.; Jarvis, Eric E.

    1997-01-01

    Disclosed is a method to transform chlorophyll C-containing algae which includes introducing a recombinant molecule comprising a nucleic acid molecule encoding a dominant selectable marker operatively linked to an algal regulatory control sequence into a chlorophyll C-containing alga in such a manner that the marker is produced by the alga. In a preferred embodiment the algal regulatory control sequence is derived from a diatom and preferably Cyclotella cryptica. Also disclosed is a chimeric molecule having one or more regulatory control sequences derived from one or more chlorophyll C-containing algae operatively linked to a nucleic acid molecule encoding a selectable marker, an RNA molecule and/or a protein, wherein the nucleic acid molecule does not normally occur with one or more of the regulatory control sequences. Further specifically disclosed are molecules pACCNPT10, pACCNPT4.8 and pACCNPT5.1. The methods and materials of the present invention provide the ability to accomplish stable genetic transformation of chlorophyll C-containing algae.

  18. Boron uptake, localization, and speciation in marine brown algae.

    PubMed

    Miller, Eric P; Wu, Youxian; Carrano, Carl J

    2016-02-17

    In contrast to the generally boron-poor terrestrial environment, the concentration of boron in the marine environment is relatively high (0.4 mM) and while there has been extensive interest in its use as a surrogate of pH in paleoclimate studies in the context of climate change-related questions, the relatively depth independent, and the generally non-nutrient-like concentration profile of this element have led to boron being neglected as a potentially biologically relevant element in the ocean. Among the marine plant-like organisms the brown algae (Phaeophyta) are one of only five lineages of photosynthetic eukaryotes to have evolved complex multicellularity. Many of unusual and often unique features of brown algae are attributable to this singular evolutionary history. These adaptations are a reflection of the marine coastal environment which brown algae dominate in terms of biomass. Consequently, brown algae are of fundamental importance to oceanic ecology, geochemistry, and coastal industry. Our results indicate that boron is taken up by a facilitated diffusion mechanism against a considerable concentration gradient. Furthermore, in both Ectocarpus and Macrocystis some boron is most likely bound to cell wall constituent alginate and the photoassimilate mannitol located in sieve cells. Herein, we describe boron uptake, speciation, localization and possible biological function in two species of brown algae, Macrocystis pyrifera and Ectocarpus siliculosus. PMID:26679972

  19. Chemical characterization of torbanites by transmission micro-FTIR spectroscopy: Origin and extent of compositional heterogeneities

    SciTech Connect

    Landais, P.; Rochdi, A. ); Largeau, C.; Derenne, S. )

    1993-06-01

    Four Permian to Carboniferous torbanites of various geographical origins were examined by transmission micro-FTIR spectroscopy on doubly polished thin sections (10--25 [mu]m). Several types of heterogeneities (different types of organic matrix; yellow and orange Botryococcus braunii colonies) were identified and chemically characterized. Important differences were noted between the organic constituents of the matrix and the algal bodies, regarding the intensity of OH, C[double bond]O, and aromatic C[double bond]C absorptions. The previous IR studies of torbanites on bulk samples therefore afforded substantially biased information on the composition of B. braunii fossil colonies, on their oil potential, and on the maturity of such kerogens. Micro-FTIR spectra indicate that the organic matrix corresponds neither to an extensive breaking up of colonies nor to humic substances. This matrix is highly heterogeneous; two types were identified in the Autun sample (chiefly corresponding to degraded algal and bacterial constituents, respectively). A precise characterization of the organic matrix was made difficult, however, in Pumpherston torbanite, due to intimate mixing with minerals. The co-occurrence of yellow and orange colonies, with contrasted micro-FTIR features, in Autun torbanite neither reflects radiolysis processes nor differences in maturation and/or source algae. A specific spatial relation was observed between these two types of algal bodies and the organo-mineral matrix, thus revealing differences in colony microenvironment after deposition. The orange colonies are likely derived, in agreement with their micro-FTIR spectra and their spatial correlation with the matrix, from sedimentological and/or matrix-catalyzed diagenetic transformations of some yellow colonies. This first application of micro-FTIR to kerogens confirmed the utility of this nondestructive, in situ pin-point method. 69 refs., 9 figs., 4 tabs.

  20. Designer proton-channel transgenic algae for photobiological hydrogen production

    DOEpatents

    Lee, James Weifu

    2011-04-26

    A designer proton-channel transgenic alga for photobiological hydrogen production that is specifically designed for production of molecular hydrogen (H.sub.2) through photosynthetic water splitting. The designer transgenic alga includes proton-conductive channels that are expressed to produce such uncoupler proteins in an amount sufficient to increase the algal H.sub.2 productivity. In one embodiment the designer proton-channel transgene is a nucleic acid construct (300) including a PCR forward primer (302), an externally inducible promoter (304), a transit targeting sequence (306), a designer proton-channel encoding sequence (308), a transcription and translation terminator (310), and a PCR reverse primer (312). In various embodiments, the designer proton-channel transgenic algae are used with a gas-separation system (500) and a gas-products-separation and utilization system (600) for photobiological H.sub.2 production.

  1. The evolution of photosynthesis in chromist algae through serial endosymbioses

    PubMed Central

    Stiller, John W.; Schreiber, John; Yue, Jipei; Guo, Hui; Ding, Qin; Huang, Jinling

    2014-01-01

    Chromist algae include diverse photosynthetic organisms of great ecological and social importance. Despite vigorous research efforts, a clear understanding of how various chromists acquired photosynthetic organelles has been complicated by conflicting phylogenetic results, along with an undetermined number and pattern of endosymbioses, and the horizontal movement of genes that accompany them. We apply novel statistical approaches to assess impacts of endosymbiotic gene transfer on three principal chromist groups at the heart of long-standing controversies. Our results provide robust support for acquisitions of photosynthesis through serial endosymbioses, beginning with the adoption of a red alga by cryptophytes, then a cryptophyte by the ancestor of ochrophytes, and finally an ochrophyte by the ancestor of haptophytes. Resolution of how chromist algae are related through endosymbioses provides a framework for unravelling the further reticulate history of red algal-derived plastids, and for clarifying evolutionary processes that gave rise to eukaryotic photosynthetic diversity. PMID:25493338

  2. Extremophilic micro-algae and their potential contribution in biotechnology.

    PubMed

    Varshney, Prachi; Mikulic, Paulina; Vonshak, Avigad; Beardall, John; Wangikar, Pramod P

    2015-05-01

    Micro-algae have potential as sustainable sources of energy and products and alternative mode of agriculture. However, their mass cultivation is challenging due to low survival under harsh outdoor conditions and competition from other, undesired, species. Extremophilic micro-algae have a role to play by virtue of their ability to grow under acidic or alkaline pH, high temperature, light, CO2 level and metal concentration. In this review, we provide several examples of potential biotechnological applications of extremophilic micro-algae and the ranges of tolerated extremes. We also discuss the adaptive mechanisms of tolerance to these extremes. Analysis of phylogenetic relationship of the reported extremophiles suggests certain groups of the Kingdom Protista to be more tolerant to extremophilic conditions than other taxa. While extremophilic microalgae are beginning to be explored, much needs to be done in terms of the physiology, molecular biology, metabolic engineering and outdoor cultivation trials before their true potential is realized. PMID:25443670

  3. Importance of algae as a potential source of biofuel.

    PubMed

    Singh, A K; Singh, M P

    2014-01-01

    Algae have a great potential source of biofuels and also have unique importance to reduce gaseous emissions, greenhouse gases, climatic changes, global warming receding of glaciers, rising sea levels and loss of biodiversity. The microalgae, like Scenedesmus obliquus, Neochloris oleabundans, Nannochloropsis sp., Chlorella emersonii, and Dunaliella tertiolecta have high oil content. Among the known algae, Scenedesmus obliquus is one of the most potential sources for biodiesel as it has adequate fatty acid (linolenic acid) and other polyunsaturated fatty acids. Bioethanol is already in the market of United States of America and Europe as an additive in gasoline. Biohydrogen is the cleanest biofuel and extensive efforts are going on to bring it to market at economical price. This review highlights recent development and progress in the field of algae as a potential source of biofuel. PMID:25535720

  4. Stable chloroplast transformation of the unicellular red alga Porphyridium species.

    PubMed

    Lapidot, Miri; Raveh, Dina; Sivan, Alex; Arad, Shoshana Malis; Shapira, Michal

    2002-05-01

    Red algae are extremely attractive for biotechnology because they synthesize accessory photosynthetic pigments (phycobilins and carotenoids), unsaturated fatty acids, and unique cell wall sulfated polysaccharides. We report a high-efficiency chloroplast transformation system for the unicellular red microalga Porphyridium sp. This is the first genetic transformation system for Rhodophytes and is based on use of a mutant form of the gene encoding acetohydroxyacid synthase [AHAS(W492S)] as a dominant selectable marker. AHAS is the target enzyme of the herbicide sulfometuron methyl, which effectively inhibits growth of bacteria, fungi, plants, and algae. Biolistic transformation of synchronized Porphyridium sp. cells with the mutant AHAS(W492S) gene that confers herbicide resistance gave a high frequency of sulfomethuron methyl-resistant colonies. The mutant AHAS gene integrated into the chloroplast genome by homologous recombination. This system paves the way for expression of foreign genes in red algae and has important biotechnological implications. PMID:12011332

  5. First case of human spondylodiscitis due to Shewanella algae.

    PubMed

    Gressier, Mlanie; Mbayo, Didier; Deramond, Herv; Grados, Franck; Eb, Franois; Canarelli, Brigitte

    2010-09-01

    We present the first case of human spondylodiscitis due to Shewanella algae. Our patient did not have any predisposing factors. The portal of entry was probably a cutaneous lesion on the leg, exposed to seawater. Bacteria were isolated in pure culture from a needle biopsy specimen of the vertebral disk. Automated identification systems identified the organism as Shewanella putrefaciens. However, molecular biology identified it as S. algae. Treatment with ceftriaxone and amikacin, then ciprofloxacin successfully addressed the infection. We also review four published cases of human osteoarticular infections caused by Shewanella spp: two cases of arthritis and two cases of osteomyelitis. Two patients had predisposing factors, and contact with water was found in two cases. The clinical, radiological and biological characteristics of S. algae spondylodiscitis are indistinguishable from those of spondylodiscitis of other causes. A cutaneous lesion with exposure to water is a potential portal of entry. Molecular typing is necessary to obtain a precise bacteriological identification. PMID:20171131

  6. Dasycladalean green algae and some problematic algae from the Upper Triassic of the Nayband Formation (northeast Iran)

    NASA Astrophysics Data System (ADS)

    Senowbari-Daryan, Baba; Rashidi, Koorosh; Saberzadeh, Behnam

    2011-12-01

    This paper describes the dasycladales green algae from two sections of the Rhaetian Howz-e Khan Member of the Nayband Formation, northwest of the Dig-e Rostam motorway service area (south of the type locality of the Formation near the town Naybandan). Both sections are composed of bedded fine-grained limestones containing partly abundant dasycladales algae associated with foraminifers, which are mainly aulotortid types. Additionally scattered samples were collected from several beds of the Howz-e Khan Member in this area. The following dasycladalean taxa are described: Chinianella carpatica (Bystrick), Griphoporella curvata (Gmbel), Griphoporella lutensis nov. sp., some undetermined dasycladacean taxa, problematic algae like Lithocodium aggregatum Elliott, Bacinella irregularis Radoicic, and Thaumatoporella parvovesiculifera (Raineri). While Chinianella carpatica is not numerous and the other described algae are rare, Griphoporella curvata is extremely abundant in the investigated material. This paper describes Ch. carpatica for the first time from the Triassic of Iran and also includes a discussion of the strong variability of G. curvata. Additionally we include an informal description of a problematic fossil (animal: shell fragment?; plant: alga?).

  7. Synergistic cooperation between wastewater-born algae and activated sludge for wastewater treatment: influence of algae and sludge inoculation ratios.

    PubMed

    Su, Yanyan; Mennerich, Artur; Urban, Brigitte

    2012-02-01

    An algal-bacterial culture, composed of wastewater-born algae and activated sludge, was cultivated to treat domestic wastewater and accumulate biomass simultaneously. The influence of algae and sludge inoculation ratios on the treatment efficiency and the settleability of the accumulated biomass were investigated. There was no significant effect of the inoculation ratios on the chemical oxygen demand removal. Comparatively, the nutrients removal and related mechanism were varied with different inoculation ratios. The highest nitrogen and phosphorus removal efficiencies were observed with 5:1 (algae/sludge) culture (91.0±7.0% and 93.5±2.5%, respectively) within 10 days, which was 5-40% higher and 2-4 days faster than those with other inoculation ratios. The biomass settleability was improved with the assistance of sludge, and the 1:5 (algae/sludge) culture showed the best settleability. Furthermore, 16S rDNA gene analysis showed that the bacterial communities were varying with different algae and sludge inoculation ratios and some specific bacteria were enriched during operation. PMID:22189078

  8. Oleosin of subcellular lipid droplets evolved in green algae.

    PubMed

    Huang, Nan-Lan; Huang, Ming-Der; Chen, Tung-Ling L; Huang, Anthony H C

    2013-04-01

    In primitive and higher plants, intracellular storage lipid droplets (LDs) of triacylglycerols are stabilized with a surface layer of phospholipids and oleosin. In chlorophytes (green algae), a protein termed major lipid-droplet protein (MLDP) rather than oleosin on LDs was recently reported. We explored whether MLDP was present directly on algal LDs and whether algae had oleosin genes and oleosins. Immunofluorescence microscopy revealed that MLDP in the chlorophyte Chlamydomonas reinhardtii was associated with endoplasmic reticulum subdomains adjacent to but not directly on LDs. In C. reinhardtii, low levels of a transcript encoding an oleosin-like protein (oleolike) in zygotes-tetrads and a transcript encoding oleosin in vegetative cells transferred to an acetate-enriched medium were found in transcriptomes and by reverse transcription-polymerase chain reaction. The C. reinhardtii LD fraction contained minimal proteins with no detectable oleolike or oleosin. Several charophytes (advanced green algae) possessed low levels of transcripts encoding oleosin but not oleolike. In the charophyte Spirogyra grevilleana, levels of oleosin transcripts increased greatly in cells undergoing conjugation for zygote formation, and the LD fraction from these cells contained minimal proteins, two of which were oleosins identified via proteomics. Because the minimal oleolike and oleosins in algae were difficult to detect, we tested their subcellular locations in Physcomitrella patens transformed with the respective algal genes tagged with a Green Fluorescent Protein gene and localized the algal proteins on P. patens LDs. Overall, oleosin genes having weak and cell/development-specific expression were present in green algae. We present a hypothesis for the evolution of oleosins from algae to plants. PMID:23391579

  9. Aragonitic Pennsylvanian phylloid algae from New Mexico: The missing link

    SciTech Connect

    Kirkland, B.L.; Moore, C.H. Jr. ); Dickson, J.A.D. )

    1991-03-01

    Remarkably well-preserved codiacean algae (Eugonophyllum and Anchicodium) retaining original aragonite are present in the Virgilian Holder Formation, Sacramento Mountains, south-central New Mexico. The algae are preserved in a 20-cm-thick packstone between two thick (> 5m) shale beds. Aragonite is preserved as a felt-like mesh of needles in the algal skeletons, in the shell fragments of molluscs, in the walls of sponges, and in botryoidal and isopachous marine cements. The aragonite is confirmed by X-ray diffraction, by visual inspection of pristine aragonite needles with SEM, and by a high content of Sr as revealed by microprobe analysis. The average Sr content of the algae (9,091 ppm, n = 21) is comparable to modern codiaceans. Preservation of internal structure in Eugonophyllum was previously unknown. The medullary (interior) region of the Eugonophyllum thallus is composed of an aragonite felt punctuated by small (20 {mu}m diameter), parallel utricles. As in modern codiaceans, the utricles in the cortical (exterior) region of the thallus increase in diameter and their bulbous tips coalesce to form the outer cortex of the plant. This occurrence provides a key piece of evidence in support of hypotheses concerning the nature and origin of phylloid algal bioherms. Because the internal structure of most fossil phylloid algae is replaced by sparry mosaic calcite, taxonomic classification has been difficult even at the fundamental level of division (phylum). The authors discovery confirms that at least some ancient phylloid algae resembled the modern green algae Halimeda or Udotea, and lends credibility to the suggestion that ancient phylloid algal mounds are analogous to modern Halimeda mounds of the South Pacific.

  10. Chemical composition of the green alga Codium Divaricatum Holmes.

    PubMed

    He, Zhizhou; Zhang, Anjiang; Ding, Lisheng; Lei, Xinxiang; Sun, Jianzhang; Zhang, Lixue

    2010-12-01

    A new sterol, 24-R-stigmasta-4,25-diene-3?,6?-diol (1), along with three known compounds (2-3), was isolated from the green alga Codium divaricatum Holmes, a traditional Chinese medicine, which is efficacious against cancer. All structures were determined by spectroscopic methods and comparison with related known compounds. Single-crystal X-ray crystallography allowed us to confirm the structure of 1. To our knowledge, the compound 1 is reported as the first from natural source, and compounds 2, 4 have not been isolated from green algae before. PMID:20655992

  11. Antimicrobial effect of phlorotannins from marine brown algae.

    PubMed

    Eom, Sung-Hwan; Kim, Young-Mog; Kim, Se-Kwon

    2012-09-01

    Marine organisms exhibit a rich chemical content that possess unique structural features as compared to terrestrial metabolites. Among marine resources, marine algae are a rich source of chemically diverse compounds with the possibility of their potential use as a novel class of artificial food ingredients and antimicrobial agents. The objective of this brief review is to identify new candidate drugs for antimicrobial activity against food-borne pathogenic bacteria. Bioactive compounds derived from brown algae are discussed, namely phlorotannins, that have anti-microbial effects and therefore may be useful to explore as potential antimicrobial agents for the food and pharmaceutical industries. PMID:22735502

  12. Heavy metals in marine algae of the Kuwait coast

    SciTech Connect

    Buo-Olayan, A.H.; Subrahmanyam, M.N.V.

    1996-12-31

    Marine algae are considered as important primary producers in the coastal region. Several marine algal species are being considered as raw material for various economically important products and this has resulted in their increasing demand. Marine algal species also have been suggested to be the indicators of pollution. Keeping in view the importance of marine algal species for direct or indirect human and cattle consumption, it is necessary to monitor the bioaccumulation of certain elements in these species. This study was aimed at establishing the concentration levels of trace metals in marine algae of the Kuwait coast. 26 refs., 1 fig., 3 tabs.

  13. Algae Biofuels Co-Location Assessment Tool for Canada

    SciTech Connect

    2011-11-29

    The Algae Biofuels Co-Location Assessment Tool for Canada uses chemical stoichiometry to estimate Nitrogen, Phosphorous, and Carbon atom availability from waste water and carbon dioxide emissions streams, and requirements for those same elements to produce a unit of algae. This information is then combined to find limiting nutrient information and estimate potential productivity associated with waste water and carbon dioxide sources. Output is visualized in terms of distributions or spatial locations. Distances are calculated between points of interest in the model using the great circle distance equation, and the smallest distances found by an exhaustive search and sort algorithm.

  14. Algae as promising organisms for environment and health

    PubMed Central

    2011-01-01

    Algae, like other plants, produce a variety of remarkable compounds collectively referred to as secondary metabolites. They are synthesized by these organisms at the end of the growth phase and/or due to metabolic alterations induced by environmental stress conditions. Carotenoids, phenolic compounds, phycobiliprotein pigments, polysaccharides and unsaturated fatty acids are same of the algal natural products, which were reported to have variable biological activities, including antioxidant activity, anticancer activity, antimicroabial activity against bacteria-virus-algae-fungi, organic fertilizer and bioremediation potentials. PMID:21862867

  15. Algae Biofuels Co-Location Assessment Tool for Canada

    Energy Science and Technology Software Center (ESTSC)

    2011-11-29

    The Algae Biofuels Co-Location Assessment Tool for Canada uses chemical stoichiometry to estimate Nitrogen, Phosphorous, and Carbon atom availability from waste water and carbon dioxide emissions streams, and requirements for those same elements to produce a unit of algae. This information is then combined to find limiting nutrient information and estimate potential productivity associated with waste water and carbon dioxide sources. Output is visualized in terms of distributions or spatial locations. Distances are calculated betweenmore » points of interest in the model using the great circle distance equation, and the smallest distances found by an exhaustive search and sort algorithm.« less

  16. Value of crops: Quantity, quality and cost price. [algae as a nutritional supplement

    NASA Technical Reports Server (NTRS)

    Meyer, C.

    1979-01-01

    Possibilities of using algae as a nutritional supplement are examined. The nutritional value and protein content of spirulines of blue algae are discussed. A cost analysis of growing them artificially is presented.

  17. MONITORING CHLOROPHYLL-A AS A MEASURE OF ALGAE IN LAKE WATER

    EPA Science Inventory

    Algae are an important quality component in water bodies. They are photosynthesizing organisms and are the foundation of most aquatic food webs; however, some algae (e.g. blue-green algae) can produce algal toxins. The presence of algal toxins in water bodies has important ...

  18. Where Have All the Algae Gone, or, How Many Kingdoms Are There?

    ERIC Educational Resources Information Center

    Blackwell, Will H.; Powell, Martha J.

    1995-01-01

    Examined 10 introductory college-level, general biology survey textbooks for the coverage of algae to assess the efficacy of coverage. Describes a proposal of seven kingdoms and discusses the disposition of algae among five of these kingdoms. Contends that textbooks should highlight the concept of algae across the five kingdoms. Contains 59

  19. CLOSING THE CARBON LOOP: GROWING ALGAE USING SUSTAINABLE CO2 FROM BIO-WASTE

    EPA Science Inventory

    Record oil prices, poor air quality, and the threat of global warming have resulted in renewed interest in micro algae for its great potential as a biofuels feedstock. However, research is predominantly focused on growing algae with coal flue gas, and extracting the algae oils...

  20. Where Have All the Algae Gone, or, How Many Kingdoms Are There?

    ERIC Educational Resources Information Center

    Blackwell, Will H.; Powell, Martha J.

    1995-01-01

    Examined 10 introductory college-level, general biology survey textbooks for the coverage of algae to assess the efficacy of coverage. Describes a proposal of seven kingdoms and discusses the disposition of algae among five of these kingdoms. Contends that textbooks should highlight the concept of algae across the five kingdoms. Contains 59…

  1. Switchable photosystem-II designer algae for photobiological hydrogen production

    DOEpatents

    Lee, James Weifu

    2010-01-05

    A switchable photosystem-II designer algae for photobiological hydrogen production. The designer transgenic algae includes at least two transgenes for enhanced photobiological H.sub.2 production wherein a first transgene serves as a genetic switch that can controls photosystem II (PSII) oxygen evolution and a second transgene encodes for creation of free proton channels in the algal photosynthetic membrane. In one embodiment, the algae includes a DNA construct having polymerase chain reaction forward primer (302), a inducible promoter (304), a PSII-iRNA sequence (306), a terminator (308), and a PCR reverse primer (310). In other embodiments, the PSII-iRNA sequence (306) is replaced with a CF.sub.1-iRNA sequence (312), a streptomycin-production gene (314), a targeting sequence (316) followed by a proton-channel producing gene (318), or a PSII-producing gene (320). In one embodiment, a photo-bioreactor and gas-product separation and utilization system produce photobiological H.sub.2 from the switchable PSII designer alga.

  2. FINE STRUCTURE AND ORGANELLE ASSOCIATIONS IN BROWN ALGAE

    PubMed Central

    Bouck, G. Benjamin

    1965-01-01

    The structural interrelationships among several membrane systems in the cells of brown algae have been examined by electron microscopy. In the brown algae the chloroplasts are surrounded by two envelopes, the outer of which in some cases is continuous with the nuclear envelope. The pyrenoid, when present, protrudes from the chloroplast, is also surrounded by the two chloroplast envelopes, and, in addition, is capped by a third dilated envelope or "pyrenoid sac." The regular apposition of the membranes around the pyrenoid contrasts with their looser appearance over the remainder of the chloroplast. The Golgi apparatus is closely associated with the nuclear envelope in all brown algae examined, but in the Fucales this association may extend to portions of the cytoplasmic endoplasmic reticulum as well. Evidence is presented for the derivation of vesicles, characteristic of those found in the formative region of the Golgi apparatus, from portions of the underlying nuclear envelope. The possibility that a structural channeling system for carbohydrate reserves and secretory precursors may be present in brown algae is considered. Other features of the brown algal cell, such as crystal-containing bodies, the variety of darkly staining vacuoles, centrioles, and mitochondria, are examined briefly, and compared with similar structures in other plant cells. PMID:5865936

  3. LAKE PEND OREILLE, IDAHO - ATTACHED BENTHIC ALGAE (PERIPHYTON), 1986

    EPA Science Inventory

    Attached algae in the littoral zone of Pend Oreille Lake, a large deep meso-oligotrophic lake in northern Idaho (17010214) was studied for comparison to estimates of pelagic productivity. The study monitored periphyton growth rates during July and August 1986 on both artificial ...

  4. Optimization of light use efficiency for biofuel production in algae.

    PubMed

    Simionato, Diana; Basso, Stefania; Giacometti, Giorgio M; Morosinotto, Tomas

    2013-12-01

    A major challenge for next decades is development of competitive renewable energy sources, highly needed to compensate fossil fuels reserves and reduce greenhouse gas emissions. Among different possibilities, which are currently under investigation, there is the exploitation of unicellular algae for production of biofuels and biodiesel in particular. Some algae species have the ability of accumulating large amount of lipids within their cells which can be exploited as feedstock for the production of biodiesel. Strong research efforts are however still needed to fulfill this potential and optimize cultivation systems and biomass harvesting. Light provides the energy supporting algae growth and available radiation must be exploited with the highest possible efficiency to optimize productivity and make microalgae large scale cultivation energetically and economically sustainable. Investigation of the molecular bases influencing light use efficiency is thus seminal for the success of this biotechnology. In this work factors influencing light use efficiency in algal biomass production are reviewed, focusing on how algae genetic engineering and control of light environment within photobioreactors can improve the productivity of large scale cultivation systems. PMID:23876487

  5. A green Paramecium strain with abnormal growth of symbiotic algae.

    PubMed

    Irie, Kanami; Furukawa, Shunsuke; Kadono, Takashi; Kawano, Tomonori

    2010-01-01

    Some hundred cells of Chlorella-like green algae are naturally enclosed within the cytoplasm of a single cell of green paramecia (Paramecium bursaria). Therefore, P. bursaria serves as an experimental model for studying the nature of endo-symbiosis made up through chemical communication between the symbiotic partners. For studying the mechanism of symbiotic regulations, the materials showing successful symbiosis are widely used. Apart from such successful model materials, some models for symbiotic distortion would be of great interest in order to understand the nature of successful symbiosis. Here, we describe a case of unsuccessful symbiosis causing unregulated growth of algae inside the hosting ciliates. Recently, we have screened some cell lines, from the mass of P. bursaria cells survived after paraquat treatment. The resultant cell lines (designated as KMZ series) show novel and unusual morphological features with heavily darker green colour distinguishable from the original pale green-coloured paramecia. In this type of isolates, endo-symbiotic algae are restricted within one or two dense spherical structures located at the center of the host cells' cytoplasm. Interestingly, this isolate maintains the host cells' circadian mating response which is known as an alga-dependent behaviour in the host cells. In contrast, we discuss that KMZ lacks the host-dependent regulation of algal growth, thus the algal complex often over-grows obviously exceeding the original size of the normal hosting ciliates. Additionally, possible use of this isolate as a novel model for symbiotic cell-to-cell communication is discussed. PMID:21319710

  6. THE OCCURRENCE OF HORMESIS IN PLANTS AND ALGAE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper evaluated the frequency, magnitude and dose/concentration range of hormesis in four species: The aquatic plant Lemna minor, the micro-algae Pseudokirchneriella subcapitata and the two terrestrial plants Tripleurospermum inodorum and Stellaria media exposed to nine herbicides and one fung...

  7. Decreased abundance of crustose coralline algae due to ocean acidification

    USGS Publications Warehouse

    Kuffner, Ilsa B.; Andersson, Andreas J; Jokiel, Paul L.; Rodgers, Ku'ulei S.; Mackenzie, Fred T.

    2008-01-01

    Owing to anthropogenic emissions, atmospheric concentrations of carbon dioxide could almost double between 2006 and 2100 according to business-as-usual carbon dioxide emission scenarios1. Because the ocean absorbs carbon dioxide from the atmosphere2, 3, 4, increasing atmospheric carbon dioxide concentrations will lead to increasing dissolved inorganic carbon and carbon dioxide in surface ocean waters, and hence acidification and lower carbonate saturation states2, 5. As a consequence, it has been suggested that marine calcifying organisms, for example corals, coralline algae, molluscs and foraminifera, will have difficulties producing their skeletons and shells at current rates6, 7, with potentially severe implications for marine ecosystems, including coral reefs6, 8, 9, 10, 11. Here we report a seven-week experiment exploring the effects of ocean acidification on crustose coralline algae, a cosmopolitan group of calcifying algae that is ecologically important in most shallow-water habitats12, 13, 14. Six outdoor mesocosms were continuously supplied with sea water from the adjacent reef and manipulated to simulate conditions of either ambient or elevated seawater carbon dioxide concentrations. The recruitment rate and growth of crustose coralline algae were severely inhibited in the elevated carbon dioxide mesocosms. Our findings suggest that ocean acidification due to human activities could cause significant change to benthic community structure in shallow-warm-water carbonate ecosystems.

  8. Intracellular invasion of green algae in a salamander host.

    PubMed

    Kerney, Ryan; Kim, Eunsoo; Hangarter, Roger P; Heiss, Aaron A; Bishop, Cory D; Hall, Brian K

    2011-04-19

    The association between embryos of the spotted salamander (Ambystoma maculatum) and green algae ("Oophila amblystomatis" Lamber ex Printz) has been considered an ectosymbiotic mutualism. We show here, however, that this symbiosis is more intimate than previously reported. A combination of imaging and algal 18S rDNA amplification reveals algal invasion of embryonic salamander tissues and cells during development. Algal cells are detectable from embryonic and larval Stages 26-44 through chlorophyll autofluorescence and algal 18S rDNA amplification. Algal cell ultrastructure indicates both degradation and putative encystment during the process of tissue and cellular invasion. Fewer algal cells were detected in later-stage larvae through FISH, suggesting that the decline in autofluorescent cells is primarily due to algal cell death within the host. However, early embryonic egg capsules also contained encysted algal cells on the inner capsule wall, and algal 18S rDNA was amplified from adult reproductive tracts, consistent with oviductal transmission of algae from one salamander generation to the next. The invasion of algae into salamander host tissues and cells represents a unique association between a vertebrate and a eukaryotic alga, with implications for research into cell-cell recognition, possible exchange of metabolites or DNA, and potential congruence between host and symbiont population structures. PMID:21464324

  9. Expression and assembly of a fully active antibody in algae

    NASA Astrophysics Data System (ADS)

    Mayfield, Stephen P.; Franklin, Scott E.; Lerner, Richard A.

    2003-01-01

    Although combinatorial antibody libraries have solved the problem of access to large immunological repertoires, efficient production of these complex molecules remains a problem. Here we demonstrate the efficient expression of a unique large single-chain (lsc) antibody in the chloroplast of the unicellular, green alga, Chlamydomonas reinhardtii. We achieved high levels of protein accumulation by synthesizing the lsc gene in chloroplast codon bias and by driving expression of the chimeric gene using either of two C. reinhardtii chloroplast promoters and 5' and 3' RNA elements. This lsc antibody, directed against glycoprotein D of the herpes simplex virus, is produced in a soluble form by the alga and assembles into higher order complexes in vivo. Aside from dimerization by disulfide bond formation, the antibody undergoes no detectable posttranslational modification. We further demonstrate that accumulation of the antibody can be modulated by the specific growth regime used to culture the alga, and by the choice of 5' and 3' elements used to drive expression of the antibody gene. These results demonstrate the utility of alga as an expression platform for recombinant proteins, and describe a new type of single chain antibody containing the entire heavy chain protein, including the Fc domain.

  10. Fatty acid amides from freshwater green alga Rhizoclonium hieroglyphicum.

    PubMed

    Dembitsky, V M; Shkrob, I; Rozentsvet, O A

    2000-08-01

    Freshwater green algae Rhizoclonium hieroglyphicum growing in the Ural Mountains were examined for their fatty acid amides using capillary gas chromatography-mass spectrometry (GC-MS). Eight fatty acid amides were identified by GC-MS. (Z)-9-octadecenamide was found to be the major component (2.26%). PMID:11014298

  11. Energy-water nexus for mass cultivation of algae.

    PubMed

    Murphy, Cynthia Folsom; Allen, David T

    2011-07-01

    Microalgae are currently considered a potential feedstock for the production of biofuels. This work addresses the energy needed to manage the water used in the mass cultivation of saline, eukaryotic algae grown in open pond systems. Estimates of both direct and upstream energy requirements for obtaining, containing, and circulating water within algae cultivation systems are developed. Potential productivities are calculated for each of the 48 states within the continental U.S. based on theoretical photosynthetic efficiencies, growing season, and total available land area. Energy output in the form of algal biodiesel and the total energy content of algal biomass are compared to energy inputs required for water management. The analysis indicates that, for current technologies, energy required for water management alone is approximately seven times greater than energy output in the form of biodiesel and more than double that contained within the entire algal biomass. While this analysis addresses only currently identified species grown in an open-pond system, the water management requirements of any algae system will be substantial; therefore, it is critical that an energy assessment of water management requirements be performed for any cultivation technology and algal type in order to fully understand the energy balance of algae-derived biofuels. PMID:21671675

  12. Survey of Hydrogenase Activity in Algae: Final Report

    SciTech Connect

    Brand, J. J.

    1982-04-01

    The capacity for hydrogen gas production was examined in nearly 100 strains of Eukaryotic algae. Each strain was assessed for rate of H2 production in darkness, at compensating light intensity and at saturating Tight intensity. Maximum H2 yield on illumination and sensitivity to molecular oxygen were also measured.

  13. Decreased abundance of crustose coralline algae due to ocean acidification

    NASA Astrophysics Data System (ADS)

    Kuffner, Ilsa B.; Andersson, Andreas J.; Jokiel, Paul L.; Rodgers, Ku`Ulei S.; MacKenzie, Fred T.

    2008-02-01

    Owing to anthropogenic emissions, atmospheric concentrations of carbon dioxide could almost double between 2006 and 2100 according to business-as-usual carbon dioxide emission scenarios. Because the ocean absorbs carbon dioxide from the atmosphere, increasing atmospheric carbon dioxide concentrations will lead to increasing dissolved inorganic carbon and carbon dioxide in surface ocean waters, and hence acidification and lower carbonate saturation states. As a consequence, it has been suggested that marine calcifying organisms, for example corals, coralline algae, molluscs and foraminifera, will have difficulties producing their skeletons and shells at current rates, with potentially severe implications for marine ecosystems, including coral reefs. Here we report a seven-week experiment exploring the effects of ocean acidification on crustose coralline algae, a cosmopolitan group of calcifying algae that is ecologically important in most shallow-water habitats. Six outdoor mesocosms were continuously supplied with sea water from the adjacent reef and manipulated to simulate conditions of either ambient or elevated seawater carbon dioxide concentrations. The recruitment rate and growth of crustose coralline algae were severely inhibited in the elevated carbon dioxide mesocosms. Our findings suggest that ocean acidification due to human activities could cause significant change to benthic community structure in shallow-warm-water carbonate ecosystems.

  14. Intracellular invasion of green algae in a salamander host

    PubMed Central

    Kerney, Ryan; Kim, Eunsoo; Hangarter, Roger P.; Heiss, Aaron A.; Bishop, Cory D.; Hall, Brian K.

    2011-01-01

    The association between embryos of the spotted salamander (Ambystoma maculatum) and green algae (Oophila amblystomatis Lamber ex Printz) has been considered an ectosymbiotic mutualism. We show here, however, that this symbiosis is more intimate than previously reported. A combination of imaging and algal 18S rDNA amplification reveals algal invasion of embryonic salamander tissues and cells during development. Algal cells are detectable from embryonic and larval Stages 2644 through chlorophyll autofluorescence and algal 18S rDNA amplification. Algal cell ultrastructure indicates both degradation and putative encystment during the process of tissue and cellular invasion. Fewer algal cells were detected in later-stage larvae through FISH, suggesting that the decline in autofluorescent cells is primarily due to algal cell death within the host. However, early embryonic egg capsules also contained encysted algal cells on the inner capsule wall, and algal 18S rDNA was amplified from adult reproductive tracts, consistent with oviductal transmission of algae from one salamander generation to the next. The invasion of algae into salamander host tissues and cells represents a unique association between a vertebrate and a eukaryotic alga, with implications for research into cellcell recognition, possible exchange of metabolites or DNA, and potential congruence between host and symbiont population structures. PMID:21464324

  15. 21 CFR 73.185 - Haematococcus algae meal.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... stabilized color additive mixture. Color additive mixtures for fish feed use made with haematococcus algae... salmonid fish in accordance with the following prescribed conditions: (1) The color additive is used to... section. (2) The presence of the color additive in finished fish feed prepared according to paragraph...

  16. 21 CFR 73.185 - Haematococcus algae meal.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... stabilized color additive mixture. Color additive mixtures for fish feed use made with haematococcus algae... salmonid fish in accordance with the following prescribed conditions: (1) The color additive is used to... section. (2) The presence of the color additive in finished fish feed prepared according to paragraph...

  17. 21 CFR 73.185 - Haematococcus algae meal.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... stabilized color additive mixture. Color additive mixtures for fish feed use made with haematococcus algae... salmonid fish in accordance with the following prescribed conditions: (1) The color additive is used to... section. (2) The presence of the color additive in finished fish feed prepared according to paragraph...

  18. TOXICITY AND UPTAKE OF KEPONE IN MARINE UNICELLULAR ALGAE

    EPA Science Inventory

    Four species of marine unicellular algae were exposed to Kepone in laboratory bioassays. EC50 values after seven days' growth, in micrograms/liter (ppm), were--Chlorococcum sp., 0.35; Dunaliella tertiolecta, 0.58; Nitzschia sp., 0.60; Thalassiosira pseudonana, 0.60. When exposed ...

  19. ASPECTS OF PHOSPHATE UTILIZATION BY BLUE-GREEN ALGAE

    EPA Science Inventory

    The effects of various external phosphate concentrations on physiological and cytological aspects of Plectonema boryanum have been studied. P. boryanum was found to tolerate a wide range of phosphate concentrations, from 1 to 1000 mg of phosphate per liter. Growth of the alga in ...

  20. Controlled artificial upwelling in a fjord to combat toxic algae

    NASA Astrophysics Data System (ADS)

    McClimans, T. A.; Hansen, A. H.; Fredheim, A.; Lien, E.; Reitan, K. I.

    2003-04-01

    During the summer, primary production in the surface layers of some fjords depletes the nutrients to the degree that some arts of toxic algae dominate the flora. We describe an experiment employing a bubble curtain to lift significant amounts of nutrient-rich seawater to the light zone and provide an environment in which useful algae can survive. The motivation for the experiment is to provide a local region in which mussels can be cleansed from the effects of toxic algae. Three 100-m long, perforated pipes were suspended at 40 m depth in the Arnafjord, a side arm of the Sognefjord. Large amounts of compressed air were supplied during a period of three weeks. The deeper water mixed with the surface water and flowed from the mixing region at 5 to 15 m depth. Within a few days, the mixture of nutrient-rich water covered most of the inner portion of Arnafjord. Within 10 days, the plankton samples showed that the artificial upwelling produced the desired type of algae and excluded the toxic blooms that were occurring outside the manipulated fjord arm. The project (DETOX) is supported by the Norwegian ministries of Fisheries, Agriculture and Public Administration.

  1. Biodegradation of phenols by the alga Ochromonas danica.

    PubMed Central

    Semple, K T; Cain, R B

    1996-01-01

    The eukaryotic alga Ochromonas danica, a nutritionally versatile, mixotrophic chrysophyte, grew on phenol as the sole carbon source in axenic culture and removed the phenol carbon from the growth medium. Respirometric studies confirmed that the enzymes involved in phenol catabolism were inducible and that the alga oxidized phenol; the amount of oxygen consumed per mole of oxidized substrate was approximately 65% of the theoretical value. [U-14C]phenol was completely mineralized, with 65% of the 14C label appearing as 14CO2, approximately 15% remaining in the aqueous medium, and the rest accounted for in the biomass. Analysis of the biomass showed that 14C label had been incorporated into the protein, nucleic acid, and lipid fractions; phenol carbon is thus unequivocally assimilated by the alga. Phenol-grown cultures of O. danica converted phenols to the corresponding catechols, which were further metabolized by the meta-cleavage pathway. This surprising result was rigorously confirmed by taking the working stock culture through a variety of procedures to check that it was axenic and repeating the experiments with algal extracts. This is, as far as is known, the first definitive identification of the meta-cleavage pathway for aromatic ring degradation in a eukaryotic alga, though its incidence in other eukaryotes has been (infrequently) suggested. PMID:8919787

  2. Effect of sonication frequency on the disruption of algae.

    PubMed

    Kurokawa, Masaki; King, Patrick M; Wu, Xiaoge; Joyce, Eadaoin M; Mason, Timothy J; Yamamoto, Ken

    2016-07-01

    In this study, the efficiency of ultrasonic disruption of Chaetoceros gracilis, Chaetoceros calcitrans, and Nannochloropsis sp. was investigated by applying ultrasonic waves of 0.02, 0.4, 1.0, 2.2, 3.3, and 4.3MHz to algal suspensions. The results showed that reduction in the number of algae was frequency dependent and that the highest efficiency was achieved at 2.2, 3.3, and 4.3MHz for C. gracilis, C. calcitrans, and Nannochloropsis sp., respectively. A review of the literature suggested that cavitation, rather than direct effects of ultrasonication, are required for ultrasonic algae disruption, and that chemical effects are likely not the main mechanism for algal cell disruption. The mechanical resonance frequencies estimated by a shell model, taking into account elastic properties, demonstrated that suitable disruption frequencies for each alga were associated with the cell's mechanical properties. Taken together, we consider here that physical effects of ultrasonication were responsible for algae disruption. PMID:26964936

  3. Biodegradation of an oily bilge waste using algae

    SciTech Connect

    Carpenter, M.J.

    1987-01-01

    A mixed community of microogranisms was collected from the harbor at the North Island Navy Base and was monitored in a test ecosystem containing an oily bilge waste obtained from off-loading ships. Cultures were examined in the presence and absence of the algae. It was thought that the algae might enhance the degradation of the oil waste by providing oxygen and possibly a nutrient source from dying phytoplankton for the bacterial community. The change in community structure was monitored by isolating the various groups of organisms and determining the biomass change over time for the algae, bacteria and yeasts/fungi subjected to the bilge waste. The biomass (i.e., colony forming units) of the yeasts and fungi increased 100 fold in a 6 week test period. The community containing only the bacteria and fungi/yeasts lost the fungal component of the population, although active bacteria biomass increased more than 10 fold during exposure to the waste. The test ecosystem was subjected to a radiolabeled compound (/sup 14/C-phenol) and bilge waste mixture to ascertain the ability of the communities to mineralize the phenol and/or assimilate the labeled hydrocarbon. The community containing the algae started mineralizing the phenol (measure by /sup 14/CO/sub 2/ production) 24 hours after exposure to the waste/phenol mixture. The bacteria/yeast-fungi community had a lag period of 384 hours before extensive catabolism of the labeled compound occurred. Current data indicate algae may enhance the biodegradation rate of oil bilge waste in a mixed microbial community.

  4. Photosynthetic H2 metabolism in Chlamydomonas reinhardtii (unicellular green algae).

    PubMed

    Melis, Anastasios

    2007-10-01

    Unicellular green algae have the ability to operate in two distinctly different environments (aerobic and anaerobic), and to photosynthetically generate molecular hydrogen (H2). A recently developed metabolic protocol in the green alga Chlamydomonas reinhardtii permitted separation of photosynthetic O2-evolution and carbon accumulation from anaerobic consumption of cellular metabolites and concomitant photosynthetic H2-evolution. The H2 evolution process was induced upon sulfate nutrient deprivation of the cells, which reversibly inhibits photosystem-II and O2-evolution in their chloroplast. In the absence of O2, and in order to generate ATP, green algae resorted to anaerobic photosynthetic metabolism, evolved H2 in the light and consumed endogenous substrate. This study summarizes recent advances on green algal hydrogen metabolism and discusses avenues of research for the further development of this method. Included is the mechanism of a substantial tenfold starch accumulation in the cells, observed promptly upon S-deprivation, and the regulated starch and protein catabolism during the subsequent H2-evolution. Also discussed is the function of a chloroplast envelope-localized sulfate permease, and the photosynthesis-respiration relationship in green algae as potential tools by which to stabilize and enhance H2 metabolism. In addition to potential practical applications of H2, approaches discussed in this work are beginning to address the biochemistry of anaerobic H2 photoproduction, its genes, proteins, regulation, and communication with other metabolic pathways in microalgae. Photosynthetic H2 production by green algae may hold the promise of generating a renewable fuel from nature's most plentiful resources, sunlight and water. The process potentially concerns global warming and the question of energy supply and demand. PMID:17721788

  5. Spectral optical properties of selected photosynthetic microalgae producing biofuels

    NASA Astrophysics Data System (ADS)

    Lee, Euntaek; Heng, Ri-Liang; Pilon, Laurent

    2013-01-01

    This paper presents the spectral complex index of refraction of biofuel producing photosynthetic microalgae between 400 and 750 nm. They were retrieved from their experimentally measured average absorption and scattering cross-sections. The microalgae were treated as homogeneous polydisperse spheres with equivalent diameter such that their surface area was identical to that of their actual spheroidal shape. An inverse method was developed combining Lorentz-Mie theory as the forward method and genetic algorithm. The unicellular green algae Chlamydomonas reinhardtii strain CC125 and its truncated chlorophyll antenna transformants tla1, tlaX, and tla1-CW+ as well as Botryococcus braunii, Chlorella sp., and Chlorococcum littorale were investigated. These species were selected for their ability to produce either hydrogen gas or lipids for liquid fuel production. Their retrieved real and imaginary parts of the complex index of refraction were continuous functions of wavelength with absorption peaks corresponding to those of in vivo Chlorophylls a and b. The T-matrix method was also found to accurately predict the experimental measurements by treating the microalgae as axisymmetric spheroids with the experimentally measured major and minor diameter distributions and the retrieved spectral complex index of refraction. Finally, pigment mass fractions were also estimated from the retrieved absorption index. The method and/or the reported optical properties can be used in various applications from ocean remote sensing, carbon cycle study, as well as photobiological carbon dioxide mitigation and biofuel production.

  6. Triterpene hydrocarbon production engineered into a metabolically versatile host--Rhodobacter capsulatus.

    PubMed

    Khan, Nymul E; Nybo, S Eric; Chappell, Joe; Curtis, Wayne R

    2015-08-01

    Triterpene hydrocarbon biosynthesis of the ancient algae Botryococcus braunii was installed into Rhodobacter capsulatus to explore the production of C30 hydrocarbon in a host capable of diverse growth habits-utilizing carbohydrate, sunlight or hydrogen (with CO2 fixation) as alternative energy feedstocks. Engineering an enhanced MEP pathway was also used to augment triterpene accumulation. Despite dramatically different sources of carbon and reducing power, nearly the same level of botryococcene or squalene (∼5 mg oil/g-dry-weight [gDW]) was achieved in small-scale aerobic heterotrophic, anaerobic photoheterotrophic, and aerobic chemoautotrophic growth conditions. A glucose fed-batch bioreactor reached 40 mg botryococcene/L (∼12 mg/gDW), while autotrophic bioreactor performance with CO2 , H2 , and O2 reached 110 mg/L (16.7 mg/gDW) during batch and 60 mg/L (23 mg/gDW) during continuous operation at a dilution rate corresponding to about 10% of μ(max). Batch and continuous autotrophic specific productivity was found to reach 0.5 and 0.32 mg triterpene/g DW/h, comparable to prior reports for terpene production driven by heterotrophic growth conditions. This demonstrates the feasibility of alternative feedstocks and trophic modes to provide comparable routes to biochemicals that do not rely on sugar. PMID:25728701

  7. Recovery of dilute metal ions by biosorption on river algae and its component

    SciTech Connect

    Fujita, Toyohisa; Kogita, Hiroki; Mamiya, Mitsuo; Yen, W.T.

    1995-12-31

    Green algae taken from an acidic mine drainage and blue-green algae take from an alkaline hot spring stream were collected and tested for their ability to recover or remove dilute metal ions. Experimental results demonstrated that unwashed blue-green algae and washed green algae effectively adsorbed base metals ions and eluted the at pH 1. It was also found that washed and dried algae adsorbed precious metal ions more effectively than unwashed algae. For example, the washed and dried blue-green algae was capable of adsorbing 0.31 kg of gold pre kg of algae. The gold from tetrachloroaurate solution which was adsorbed on washed blue-green algae was found to change to a metallic state following initial metal binding. In the case of a dilute gold complex solution leached with thiourea, only a small amount of gold could be captured by algae. Further experiments were conducted on components of the algae, such as alginic acid, agar, cellulose and chitin and mixtures of these components, in order to determine their contribution to metal adsorption characteristics. However, a mixture of these two components demonstrated both good adsorption and desorption characteristics indicating an interaction between the individual components.

  8. Photoreduction of chromium(VI) in the presence of algae, Chlorella vulgaris.

    PubMed

    Deng, Lin; Wang, Hongli; Deng, Nansheng

    2006-11-16

    In this thesis, the photochemical reduction of hexavalent chromium Cr(VI) in the presence of algae, Chlorella vulgaris, was investigated under the irradiation of metal halide lamps (lambda = 365 nm, 250 W). The affecting factors of photochemical reduction were studied in detail, such as exposure time, initial Cr(VI) concentration, initial algae concentration and pH. The rate of Cr(VI) photochemical reduction increased with algae concentration increasing, exposure time increasing, initial Cr(VI) concentration decreasing and the decrease of pH. When pH increased to 6, the rate of Cr(VI) photochemical reduction nearly vanished. When initial Cr(VI) concentration ranged from 0.4 to 1.0 mg L(-1) and initial algae concentration ranged from ABS(algae) (the absorbency of algae) = 0.025 to ABS(algae) = 0.180, According to the results of kinetic analyses, the kinetic equation of Cr(VI) photochemical reduction in aqueous solution with algae under 250 W metal halide lamps was V0 = kC(0)(0.1718)A(algae)(0.5235) (C0 was initial concentration of Cr(VI); A(algae) was initial concentration of algae) under the condition of pH 4. PMID:16839665

  9. Biosorption of lead and nickel by biomass of marine algae.

    PubMed

    Holan, Z R; Volesky, B

    1994-05-01

    Screening tests of different marine algae biomas types revealed a high passive biosorptive uptake of lead up to 270 mg Pb/g of biomass in some brown marine algae. Members of the order Fucales perfomed particularly well in this descending sequence: Fucus > Ascophyllum > Sargassum. Although decreasing the swelling of wetted biomass particles, their reinforcement by crosslinking may significantly affect the biosorption performance. Lead uptakes up to 370 mg Pb/g were observed in crosslinked Fucus vesiculosus and Ascophyllum nodosum. At low equilibrium residual concentrations of lead in solution, however, ion exchange resin Amberlite IR-120 had a higher lead uptake than the biosorbent materials. An order-of-magnitude lower uptake of nickel was observed in all of the sorbent materials examined. (c) 1994 John Wiley & Sons, Inc. PMID:18615510

  10. Bioremoval of toxic elements with aquatic plants and algae

    SciTech Connect

    Wang, T.C.; Ramesh, G.; Weissman, J.C.; Varadarajan, R.; Benemann, J.R.

    1995-12-31

    Aquatic plants were screened to evaluate their ability to adsorb dissolved metals. The plants screened included those that are naturally immobilized (attached algae and rooted plants) and those that could be easily separated from suspension (filamentous microalgae, macroalgae, and floating plants). Two plants were observed to have high adsorption capabilities for cadmium (Cd) and zinc (Zn) removal: one blue green filamentous alga of the genus Phormidium and one aquatic rooted plant, water milfoil (Myriophyllum spicatum). These plants could also reduce the residual metal concentration to 0.1 mg/L or less. Both plants also exhibited high specific adsorption for other metals (Pb, Ni, and Cu) both individually and in combination. Metal concentrations were analyzed with an atomic absorption spectrophotometer (AAS).

  11. Biosorption of Lead from Wastewater Using Fresh Water Algae Chlorella.

    PubMed

    Kanchana, S; Jeyanthi, J

    2014-04-01

    The potential use of fresh water algae Chlorella to sorb lead ions from wastewater was evaluated in this study. Fourier transform infra-red analysis of algal species revealed the presence of amino, carboxylic, hydroxyl and carbonyl groups, which were responsible for biosorption of lead ions. Batch sorption experiments were performed to determine the effects of contact time, biosorbent dosage and pH on the adsorption of Pb2+ ions. The optimum conditions of biosorbent dosage, pH and contact time were found to be l0 g/L, 5 and 100 min respectively. The applicability of the Langmuir and Freundlich isotherms for representation of the experimental data was investigated. The adsorption of lead ions on the algae Chlorella fitted well with Freundlich isotherm with a very high correlation coefficient. PMID:26563070

  12. A New Noncalcified Dasycladalean Alga from the Silurian of Wisconsin

    USGS Publications Warehouse

    LoDuca, S.T.; Kluessendorf, Joanne; Mikulic, Donald G.

    2003-01-01

    Noncalcified thalli, consisting of a narrow main axis with numerous branched hairlike laterals in whorls and a subapical array of undivided clavate laterals, from the Silurian (Llandovery) Brandon Bridge Formation of southeastern Wisconsin, constitute the basis for a new genus and species of dasycladalean alga, Heterocladus waukeshaensis. A relationship within the family Triploporellaceae is indicated by the whorled arrangement of the laterals and the absence of gametophores on mature specimens. A compilation of occurrence data suggests that noncalcified dasyclads, as a whole, were more abundant and diverse during the Ordovician and Silurian than at any other time in their history. The heterocladous thallus architecture of this alga adds to a wide range of morphological variation documented among Ordovician and Silurian dasyclads, the sum of which indicates that Dasycladales underwent a significant evolutionary radiation during the early Paleozoic.

  13. Application of novel extraction technologies for bioactives from marine algae.

    PubMed

    Kadam, Shekhar U; Tiwari, Brijesh K; O'Donnell, Colm P

    2013-05-22

    Marine algae are a rich source of bioactive compounds. This paper outlines the main bioactive compounds in marine algae and recent advances in novel technologies for extracting them. Novel extraction technologies reviewed include enzyme-assisted extraction, microwave-assisted extraction, ultrasound-assisted extraction, supercritical fluid extraction, and pressurized liquid extraction. These technologies are reviewed with respect to principles, benefits, and potential applications for marine algal bioactives. Advantages of novel technologies include higher yield, reduced treatment time, and lower cost compared to traditional solvent extraction techniques. Moreover, different combinations of novel techniques used for extraction and technologies suitable for thermolabile compounds are identified. The limitations of and challenges to employing these novel extraction technologies in industry are also highlighted. PMID:23634989

  14. Marine Polysaccharides from Algae with Potential Biomedical Applications

    PubMed Central

    de Jesus Raposo, Maria Filomena; de Morais, Alcina Maria Bernardo; de Morais, Rui Manuel Santos Costa

    2015-01-01

    There is a current tendency towards bioactive natural products with applications in various industries, such as pharmaceutical, biomedical, cosmetics and food. This has put some emphasis in research on marine organisms, including macroalgae and microalgae, among others. Polysaccharides with marine origin constitute one type of these biochemical compounds that have already proved to have several important properties, such as anticoagulant and/or antithrombotic, immunomodulatory ability, antitumor and cancer preventive, antilipidaemic and hypoglycaemic, antibiotics and anti-inflammatory and antioxidant, making them promising bioactive products and biomaterials with a wide range of applications. Their properties are mainly due to their structure and physicochemical characteristics, which depend on the organism they are produced by. In the biomedical field, the polysaccharides from algae can be used in controlled drug delivery, wound management, and regenerative medicine. This review will focus on the biomedical applications of marine polysaccharides from algae. PMID:25988519

  15. [Removal of algae using local soils and sediments].

    PubMed

    Zou, Hua; Pan, Gang; Cheng, Zi-Bo

    2009-02-15

    Removal of algal blooms using modified local soils and sediments was studied. It was found that the local soils and sediments modified by chitosan removed algae effectively. The component of local soils and sediments, the organic matter in local soils and sediments had no effect on algae removal. Organic matter content (TOC < or = 40 mg/L) in water had a little negative effect on removal of algal cells. Field experimental results suggested that chitosan-modified local soils could be highly effective and quick for emergency needs to clear up harmful cyanobacterial blooms in fresh waters. In enclosures in Meiliang Bay of Taihu Lake, a loading of 0.025 g/L or 53 g/m2 chitosan-modified local soils removed 98.6% chlorophyll-a while secchi depth increased from 15 cm to 90 cm. PMID:19402489

  16. Sodium, potassium-atpases in algae and oomycetes.

    PubMed

    Barrero-Gil, Javier; Garciadeblás, Blanca; Benito, Begoña

    2005-08-01

    We have investigated the presence of K(+)-transporting ATPases that belong to the phylogenetic group of animal Na(+),K(+)-ATPases in the Pythium aphanidermatum Stramenopile oomycete, the Porphyra yezoensis red alga, and the Udotea petiolata green alga, by molecular cloning and expression in heterologous systems. PCR amplification and search in EST databases allowed one gene to be identified in each species that could encode ATPases of this type. Phylogenetic analysis of the sequences of these ATPases revealed that they cluster with ATPases of animal origin, and that the algal ATPases are closer to animal ATPases than the oomycete ATPase is. The P. yezoensis and P. aphanidermatum ATPases were functionally expressed in Saccharomyces cerevisiae and Escherichia coli alkali cation transport mutants. The aforementioned cloning and complementary searches in silicio for H(+)- and Na(+),K(+)-ATPases revealed a great diversity of strategies for plasma membrane energization in eukaryotic cells different from typical animal, plant, and fungal cells. PMID:16167182

  17. Hydrostatic factors affect the gravity responses of algae and roots

    NASA Technical Reports Server (NTRS)

    Staves, Mark P.; Wayne, Randy; Leopold, A. C.

    1991-01-01

    The hypothesis of Wayne et al. (1990) that plant cells perceive gravity by sensing a pressure differential between the top and the bottom of the cell was tested by subjecting rice roots and cells of Caracean algae to external solutions of various densities. It was found that increasing the density of the external medium had a profound effect on the polar ratio (PR, the ratio between velocities of the downwardly and upwardly streaming cytoplasm) of the Caracean algae cells. When these cells were placed in solutions of denser compound, the PR decreased to less than 1, as the density of the external medium became higher than that of the cell; thus, the normal gravity-induced polarity was reversed, indicating that the osmotic pressure of the medium affects the cell's ability to respond to gravity. In rice roots, an increase of the density of the solution inhibited the rate of gravitropism. These results agree with predictions of a hydrostatic model for graviperception.

  18. Green Algae as Model Organisms for Biological Fluid Dynamics

    NASA Astrophysics Data System (ADS)

    Goldstein, Raymond E.

    2015-01-01

    In the past decade, the volvocine green algae, spanning from the unicellular Chlamydomonas to multicellular Volvox, have emerged as model organisms for a number of problems in biological fluid dynamics. These include flagellar propulsion, nutrient uptake by swimming organisms, hydrodynamic interactions mediated by walls, collective dynamics and transport within suspensions of microswimmers, the mechanism of phototaxis, and the stochastic dynamics of flagellar synchronization. Green algae are well suited to the study of such problems because of their range of sizes (from 10 ?m to several millimeters), their geometric regularity, the ease with which they can be cultured, and the availability of many mutants that allow for connections between molecular details and organism-level behavior. This review summarizes these recent developments and highlights promising future directions in the study of biological fluid dynamics, especially in the context of evolutionary biology, that can take advantage of these remarkable organisms.

  19. Green Algae as Model Organisms for Biological Fluid Dynamics*

    PubMed Central

    Goldstein, Raymond E.

    2015-01-01

    In the past decade the volvocine green algae, spanning from the unicellular Chlamydomonas to multicellular Volvox, have emerged as model organisms for a number of problems in biological fluid dynamics. These include flagellar propulsion, nutrient uptake by swimming organisms, hydrodynamic interactions mediated by walls, collective dynamics and transport within suspensions of microswimmers, the mechanism of phototaxis, and the stochastic dynamics of flagellar synchronization. Green algae are well suited to the study of such problems because of their range of sizes (from 10 μm to several millimetres), their geometric regularity, the ease with which they can be cultured and the availability of many mutants that allow for connections between molecular details and organism-level behavior. This review summarizes these recent developments and highlights promising future directions in the study of biological fluid dynamics, especially in the context of evolutionary biology, that can take advantage of these remarkable organisms. PMID:26594068

  20. Physiology and cryosensitivity of coral endosymbiotic algae (Symbiodinium).

    PubMed

    Hagedorn, M; Carter, V L; Leong, J C; Kleinhans, F W

    2010-04-01

    Coral throughout the world are under threat. To save coral via cryopreservation methods, the Symbiodinium algae that live within many coral cells must also be considered. Coral juvenile must often take up these important cells from their surrounding water and when adult coral bleach, they lose their endosymbiotic algae and will die if they are not regained. The focus of this paper was to understand some of the cryo-physiology of the endosymbiotic algae, Symbiodinium, living within three species of Hawaiian coral, Fungia scutaria, Porites compressa and Pocillopora damicornis in Kaneohe Bay, Hawaii. Although cryopreservation of algae is common, the successful cryopreservation of these important coral endosymbionts is not common, and these species are often maintained in live serial cultures within stock centers worldwide. Freshly-extracted Symbiodinium were exposed to cryobiologically appropriate physiological stresses and their viability assessed with a Pulse Amplitude Fluorometer. Stresses included sensitivity to chilling temperatures, osmotic stress, and toxic effects of various concentrations and types of cryoprotectants (i.e., dimethyl sulfoxide, propylene glycol, glycerol and methanol). To determine the water and cryoprotectant permeabilities of Symbiodinium, uptake of radio-labeled glycerol and heavy water (D(2)O) were measured. The three different Symbiodinium subtypes studied demonstrated remarkable similarities in their morphology, sensitivity to cryoprotectants and permeability characteristics; however, they differed greatly in their sensitivity to hypo- and hyposmotic challenges and sensitivity to chilling, suggesting that standard slow freezing cryopreservation may not work well for all Symbiodinium. An appendix describes our H(2)O:D(2)O water exchange experiments and compares the diffusionally determined permeability with the two parameter model osmotic permeability. PMID:19857482

  1. Algal omics: unlocking bioproduct diversity in algae cell factories.

    PubMed

    Guarnieri, Michael T; Pienkos, Philip T

    2015-03-01

    Rapid advances in "omic" technologies are helping to unlock the full potential of microalgae as multi-use feedstocks, with utility in an array of industrial biotechnology, biofuel, and biomedical applications. In turn, algae are emerging as highly attractive candidates for development as microbial cell factories. In this review, we examine the wide array of potential algal bioproducts, with a focus upon the role of omic technologies in driving bioproduct discovery and optimization in microalgal systems. PMID:24627032

  2. The problems of Prochloron. [evolution of green algae

    NASA Technical Reports Server (NTRS)

    Lewin, R. A.

    1983-01-01

    Prokaryotic green algae (prochlorophytes), which contain chlorophylls a and b but no bilin pigments, may be phylogenetically related to ancestral chloroplasts if symbiogenesis occurred. They may be otherwise related to eukaryotic chlorophytes. They could have evolved from cyanophytes by loss of phycobilin and gain of chlorophyll b synthesis. These possibilities are briefly discussed. Relevant evidence from biochemical studies in many collaborative laboratories is now becoming available for the resolution of such questions.

  3. A preliminary study on automated freshwater algae recognition and classification system.

    TOXLINE Toxicology Bibliographic Information

    Mosleh MA; Manssor H; Malek S; Milow P; Salleh A

    2012-01-01

    BACKGROUND: Freshwater algae can be used as indicators to monitor freshwater ecosystem condition. Algae react quickly and predictably to a broad range of pollutants. Thus they provide early signals of worsening environment. This study was carried out to develop a computer-based image processing technique to automatically detect, recognize, and identify algae genera from the divisions Bacillariophyta, Chlorophyta and Cyanobacteria in Putrajaya Lake. Literature shows that most automated analyses and identification of algae images were limited to only one type of algae. Automated identification system for tropical freshwater algae is even non-existent and this study is partly to fill this gap.RESULTS: The development of the automated freshwater algae detection system involved image preprocessing, segmentation, feature extraction and classification by using Artificial neural networks (ANN). Image preprocessing was used to improve contrast and remove noise. Image segmentation using canny edge detection algorithm was then carried out on binary image to detect the algae and its boundaries. Feature extraction process was applied to extract specific feature parameters from algae image to obtain some shape and texture features of selected algae such as shape, area, perimeter, minor and major axes, and finally Fourier spectrum with principal component analysis (PCA) was applied to extract some of algae feature texture. Artificial neural network (ANN) is used to classify algae images based on the extracted features. Feed-forward multilayer perceptron network was initialized with back propagation error algorithm, and trained with extracted database features of algae image samples. System's accuracy rate was obtained by comparing the results between the manual and automated classifying methods. The developed system was able to identify 93 images of selected freshwater algae genera from a total of 100 tested images which yielded accuracy rate of 93%.CONCLUSIONS: This study demonstrated application of automated algae recognition of five genera of freshwater algae. The result indicated that MLP is sufficient, and can be used for classification of freshwater algae. However for future studies, application of support vector machine (SVM) and radial basis function (RBF) should be considered for better classifying as the number of algae species studied increases.

  4. Vegetative survival, akinete formation and germination in three blue-green algae and one green alga in relation to light intensity, temperature, heat shock and UV exposure.

    PubMed

    Agrawal, S C; Singh, V

    2000-01-01

    The mere vegetative survival was not sufficient but suitable growth conditions were required for akinete formation to occur in the blue-green algae Anabaena iyengarii, Westiellopsis prolifica, Nostochopsis lobatus and in the green alga Pithophora oedogonia. In all algae, akinetes were neither formed nor germinated in darkness, and while dim light of 300 lx was sufficient for most of akinetes to germinate and also to maintain vegetative survival, it was not adequate for optimum akinete formation. Although akinetes of all algae could germinate at 35 degrees C, both the vegetative survival and akinete formation were markedly suppressed at this temperature. Heat or UV shock of any level, whether ineffective or effecting vegetative survival, did not promote akinete formation or germination in any alga tested. Akinetes of all algae under study were relatively tolerant to heat and also to some extent to UV. Both wet and dried akinetes of all algae were equally UV tolerant. In all algae, the viability of both wet and dried akinetes decreased more or less equally with storage time, but the decrease was more drastic when storage temperature was progressively lowered from 20 to 0 degree C. Hence the akinetes can tolerate dryness but not frost. PMID:11347271

  5. Presence of state transitions in the cryptophyte alga Guillardia theta.

    PubMed

    Cheregi, Otilia; Kotabov, Eva; Pril, Ond?ej; Schrder, Wolfgang P; Ka?a, Radek; Funk, Christiane

    2015-10-01

    Plants and algae have developed various regulatory mechanisms for optimal delivery of excitation energy to the photosystems even during fluctuating light conditions; these include state transitions as well as non-photochemical quenching. The former process maintains the balance by redistributing antennae excitation between the photosystems, meanwhile the latter by dissipating excessive excitation inside the antennae. In the present study, these mechanisms have been analysed in the cryptophyte alga Guillardia theta. Photoprotective non-photochemical quenching was observed in cultures only after they had entered the stationary growth phase. These cells displayed a diminished overall photosynthetic efficiency, measured as CO2 assimilation rate and electron transport rate. However, in the logarithmic growth phase G. theta cells redistributed excitation energy via a mechanism similar to state transitions. These state transitions were triggered by blue light absorbed by the membrane integrated chlorophyll a/c antennae, and green light absorbed by the lumenal biliproteins was ineffective. It is proposed that state transitions in G. theta are induced by small re-arrangements of the intrinsic antennae proteins, resulting in their coupling/uncoupling to the photosystems in state 1 or state 2, respectively. G. theta therefore represents a chromalveolate algae able to perform state transitions. PMID:26254328

  6. An updated comprehensive techno-economic analysis of algae biodiesel.

    PubMed

    Nagarajan, Sanjay; Chou, Siaw Kiang; Cao, Shenyan; Wu, Chen; Zhou, Zhi

    2013-10-01

    Algae biodiesel is a promising but expensive alternative fuel to petro-diesel. To overcome cost barriers, detailed cost analyses are needed. A decade-old cost analysis by the U.S. National Renewable Energy Laboratory indicated that the costs of algae biodiesel were in the range of $0.53-0.85/L (2012 USD values). However, the cost of land and transesterification were just roughly estimated. In this study, an updated comprehensive techno-economic analysis was conducted with optimized processes and improved cost estimations. Latest process improvement, quotes from vendors, government databases, and other relevant data sources were used to calculate the updated algal biodiesel costs, and the final costs of biodiesel are in the range of $0.42-0.97/L. Additional improvements on cost-effective biodiesel production around the globe to cultivate algae was also recommended. Overall, the calculated costs seem promising, suggesting that a single step biodiesel production process is close to commercial reality. PMID:23260269

  7. Partitioning of monomethylmercury between freshwater algae and water.

    PubMed

    Miles, C J; Moye, H A; Phlips, E J; Sargent, B

    2001-11-01

    Phytoplankton-water monomethylmercury (MeHg) partition constants (KpI) have been determined in the laboratory for two green algae Selenastrum capricornutum and Cosmarium botrytis, the blue-green algae Schizothrix calcicola, and the diatom Thallasiosira spp., algal species that are commonly found in natural surface waters. Two methods were used to determine KpI, the Freundlich isotherm method and the flow-through/dialysis bag method. Both methods yielded KpI values of about 10(6.6) for S. capricornutum and were not significantly different. The KpI for the four algae studied were similar except for Schizothrix, which was significantly lower than S. capricornutum. The KpI for MeHg and S. capricornutum (exponential growth) was not significantly different in systems with predominantly MeHgOH or MeHgCl species. This is consistent with other studies that show metal speciation controls uptake kinetics, but the reactivity with intracellular components controls steady-state concentrations. Partitioning constants determined with exponential and stationary phase S. capricornutum cells at the same conditions were not significantly different, while the partitioning constant for exponential phase, phosphorus-limited cells was significantly lower, suggesting that P-limitation alters the ecophysiology of S. capricornutum sufficiently to impact partitioning, which may then ultimately affect mercury levels in higher trophic species. PMID:11718342

  8. Sulfated phenolic acids from Dasycladales siphonous green algae.

    PubMed

    Kurth, Caroline; Welling, Matthew; Pohnert, Georg

    2015-09-01

    Sulfated aromatic acids play a central role as mediators of chemical interactions and physiological processes in marine algae and seagrass. Among others, Dasycladus vermicularis (Scopoli) Krasser 1898 uses a sulfated hydroxylated coumarin derivative as storage metabolite for a protein cross linker that can be activated upon mechanical disruption of the alga. We introduce a comprehensive monitoring technique for sulfated metabolites based on fragmentation patterns in liquid chromatography/mass spectrometry and applied it to Dasycladales. This allowed the identification of two new aromatic sulfate esters 4-(sulfooxy)phenylacetic acid and 4-(sulfooxy)benzoic acid. The two metabolites were synthesized to prove the mass spectrometry-based structure elucidation in co-injections. We show that both metabolites are transformed to the corresponding desulfated phenols by sulfatases of bacteria. In biofouling experiments with Escherichia coli and Vibrio natriegens the desulfated forms were more active than the sulfated ones. Sulfatation might thus represent a measure of detoxification that enables the algae to store inactive forms of metabolites that are activated by settling organisms and then act as defense. PMID:26188914

  9. The effects of graphene oxide on green algae Raphidocelis subcapitata.

    PubMed

    Nogueira, P F M; Nakabayashi, D; Zucolotto, V

    2015-09-01

    Graphene represents a new class of nanomaterials that has attracted great interest due to its unique electrical, thermal, and mechanical properties. Once disposed in the environment, graphene can interact with biological systems and is expected to exhibit toxicological effects. The ecotoxicity of graphene and its derivatives, viz.: graphene oxide (GO) depends on their physicochemical properties, including purity, diameter, length, surface charge, functionalization and aggregation state. In this study we evaluated the effects of graphene oxide (GO) on green algae Raphidocelis subcapitata. The algae were exposed to different concentrations of GO pre-equilibrated for 24h with oligotrophic freshwater medium (20ml) during incubation in a growth chamber under controlled conditions: 120?Em(-2)s(-1) illumination; 12:12h light dark cycle and constant temperature of 222C. Algal growth was monitored daily for 96h by direct cell counting. Reactive oxygen species level (ROS), membrane damage (cell viability) and autofluorescence (chl-a fluorescence) were evaluated using fluorescent staining and further analyzed by flow cytometry. The toxic effects from GO, as observed in algal density and autofluorescence, started at concentrations from 20 and 10?gmL(-1), respectively. Such toxicity is probably the result of ROS generation and membrane damage (cell viability). The shading effect caused by GO agglomeration in culture medium may also contribute to reduce algal density. The results reported here provide knowledge regarding the GO toxicity on green algae, contributing to a better understanding of its environmental behavior and impacts. PMID:26204245

  10. Photosynthetic circadian rhythmicity patterns of Symbiodium, the coral endosymbiotic algae

    PubMed Central

    Sorek, Michal; Yacobi, Yosef Z.; Roopin, Modi; Berman-Frank, Ilana; Levy, Oren

    2013-01-01

    Biological clocks are self-sustained endogenous timers that enable organisms (from cyanobacteria to humans) to anticipate daily environmental rhythms, and adjust their physiology and behaviour accordingly. Symbiotic corals play a central role in the creation of biologically rich ecosystems based on mutualistic symbioses between the invertebrate coral and dinoflagellate protists from the genus Symbiodinium. In this study, we experimentally establish that Symbiodinium photosynthesis, both as a free-living unicellular algae and as part of the symbiotic association with the coral Stylophora pistillata, is wired to the circadian clock mechanism with a free-run cycle close to 24 h. Associated photosynthetic pigments also showed rhythmicity under light/dark conditions and under constant light conditions, while the expression of the oxygen-evolving enhancer 1 gene (within photosystem II) coincided with photosynthetically evolved oxygen in Symbiodinium cultures. Thus, circadian regulation of the Symbiodinium photosynthesis is, however, complicated as being linked to the coral/host that have probably profound physiochemical influence on the intracellular environment. The temporal patterns of photosynthesis demonstrated here highlight the physiological complexity and interdependence of the algae circadian clock associated in this symbiosis and the plasticity of algae regulatory mechanisms downstream of the circadian clock. PMID:23554392

  11. Bioaccumulation and catabolism of prometryne in green algae.

    PubMed

    Jin, Zhen Peng; Luo, Kai; Zhang, Shuang; Zheng, Qi; Yang, Hong

    2012-04-01

    Investigation on organic xenobiotics bioaccumulation/biodegradation in green algae is of great importance from environmental point of view because widespread distribution of these compounds in agricultural areas has become one of the major problems in aquatic ecosystem. Also, new technology needs to be developed for environmental detection and re-usage of the compounds as bioresources. Prometryne as a herbicide is widely used for killing annual grasses in China and other developing countries. However, overuse of the pesticide results in high risks to contamination to aquatic environments. In this study, we focused on analysis of bioaccumulation and degradation of prometryne in Chlamydomonas reinhardtii, a green alga, along with its adaptive response to prometryne toxicity. C. reinhardtii treated with prometryne at 2.5-12.5 ?g L(-1) for 4 d or 7.5 ?g L(-1) for 1-6 d accumulated a large quantity of prometryne, with more than 2 mg kg(-1) fresh weight in cells exposed to 10 ?g L(-1) prometryne. Moreover, it showed a great ability to degrade simultaneously the cell-accumulated prometryne. Such uptake and catabolism of prometryne led to the rapid removal of prometryne from media. Physiological and molecular analysis revealed that toxicology was associated with accumulation of prometryne in the cells. The biological processes of degradation can be interpreted as an internal tolerance mechanism. These results suggest that the green alga is useful in bioremediation of prometryne-contaminated aquatic ecosystems. PMID:22273183

  12. Photosynthetic responses and accumulation of mesotrione in two freshwater algae.

    PubMed

    Ni, Yan; Lai, Jinhu; Wan, Jinbao; Chen, Lianshui

    2014-01-01

    Mesotrione is a herbicide used for killing annual grasses and broad-leaved weeds in maize. A recent investigation has shown that mesotrione has been detected as an organic contaminant in aquatic environments and may have a negative impact on aquatic organisms. To evaluate the eco-toxicity of mesotrione to algae, experiments focusing on photosynthetic responses and mesotrione accumulation in Microcystis sp. and Scenedesmus quadricauda were carried out. Both algae treated with mesotrione at 0.05-10 mg L(-1) for 7 days reduced the photosynthetic capacity. The fluorescence of chlorophyll a, the maximal PSII activity (Fv/Fm), and the parameters (Ik, ? and ETRmax) of rapid light curves (RLCs) in both algae were decreased under mesotrione exposure. The 96 h EC50 values for mesotrione on S. quadricauda and Microcystis sp. were 4.41 and 6.19 mg L(-1), respectively. The latter shows more tolerance to mesotrione. Mesotrione was shown to be readily accumulated by both species. Such uptake of mesotrione led to the rapid removal of mesotrione from the medium. Overall, this study represents the initial comprehensive analyses of Microcystis sp. and S. quadricauda in adaptation to the mesotrione contaminated aquatic ecosystems. PMID:25059419

  13. Unveiling privacy: advances in microtomography of coralline algae.

    PubMed

    Torrano-Silva, Beatriz N; Ferreira, Simone Gomes; Oliveira, Mariana C

    2015-05-01

    Marine calcareous algae are widespread in oceans of the world and known for their calcified cell walls and the generation of rhodolith beds that turn sandy bottoms into a complex structured ecosystem with high biodiversity. Rhodoliths are unattached, branching, crustose benthic marine red algae; they provide habitat for a rich variety of marine invertebrates. The resultant excavation is relevant to sediment production, while is common that the fragments or the whole specimens result in vast fossil deposits formed by rich material that can be "mined" for biological and geological data. Accordingly, microtomography (μCT) may enable a detailed investigation of biological and geological signatures preserved within the rhodolith structure in a non-destructive approach that is especially relevant when analyzing herbaria collections or rare samples. Therefore, we prepared coralline algae samples and submitted them to a range of capabilities provided by the SkyScan1176 micro-CT scanner, including reconstruction, virtual slicing, and pinpointing biological and geological signatures. To this end, polychaetes and mollusk shells, or their excavations, coral nucleation, sediment deposits and conceptacles were all observed. Although a similar technique has been applied previously to samples of living rhodoliths in Brazil, we show, for the first time, its successful application to fossil rhodoliths. We also provide a detailed working protocol and discuss the advantages and limitations of the microtomography within the rhodoliths. PMID:25777060

  14. Metabolic engineering of higher plants and algae for isoprenoid production.

    PubMed

    Kempinski, Chase; Jiang, Zuodong; Bell, Stephen; Chappell, Joe

    2015-01-01

    Isoprenoids are a class of compounds derived from the five carbon precursors, dimethylallyl diphosphate, and isopentenyl diphosphate. These molecules present incredible natural chemical diversity, which can be valuable for humans in many aspects such as cosmetics, agriculture, and medicine. However, many terpenoids are only produced in small quantities by their natural hosts and can be difficult to generate synthetically. Therefore, much interest and effort has been directed toward capturing the genetic blueprint for their biochemistry and engineering it into alternative hosts such as plants and algae. These autotrophic organisms are attractive when compared to traditional microbial platforms because of their ability to utilize atmospheric CO2 as a carbon substrate instead of supplied carbon sources like glucose. This chapter will summarize important techniques and strategies for engineering the accumulation of isoprenoid metabolites into higher plants and algae by choosing the correct host, avoiding endogenous regulatory mechanisms, and optimizing potential flux into the target compound. Future endeavors will build on these efforts by fine-tuning product accumulation levels via the vast amount of available "-omic" data and devising metabolic engineering schemes that integrate this into a whole-organism approach. With the development of high-throughput transformation protocols and synthetic biology molecular tools, we have only begun to harness the power and utility of plant and algae metabolic engineering. PMID:25636485

  15. The origin of red algae: Implications for plastid evolution

    PubMed Central

    Stiller, John W.; Hall, Benjamin D.

    1997-01-01

    The origin of the red algae has remained an enigma. Historically the Rhodophyta were classified first as plants and later as the most ancient eukaryotic organisms. Recent molecular studies have indicated similarities between red and green plastids, which suggest that there was a single endosymbiotic origin for these organelles in a common ancestor of the rhodophytes and green plants. Previous efforts to confirm or reject this effort by analyses of nuclear DNA have been inconclusive; thus, additional molecular markers are needed to establish the relationship between the host cell lineages, independent of the evolutionary history of their plastids. To furnish such a data set we have sequenced the largest subunit of RNA polymerase II from two red algae, a green alga and a relatively derived amoeboid protist. Phylogenetic analyses provide strong statistical support for an early evolutionary emergence of the Rhodophyta that preceded the origin of the line that led to plants, animals, and fungi. These data, which are congruent with results from extensive analyses of nuclear rDNA, argue for a reexamination of current models of plastid evolution. PMID:9114022

  16. Multicellularity in green algae: upsizing in a walled complex

    PubMed Central

    Domozych, David S.; Domozych, Catherine E.

    2014-01-01

    Modern green algae constitute a large and diverse taxonomic assemblage that encompasses many multicellular phenotypes including colonial, filamentous, and parenchymatous forms. In all multicellular green algae, each cell is surrounded by an extracellular matrix (ECM), most often in the form of a cell wall. Volvocalean taxa like Volvox have an elaborate, gel-like, hydroxyproline rich glycoprotein covering that contains the cells of the colony. In ulvophytes, uronic acid-rich and sulfated polysaccharides are the likely adhesion agents that maintain the multicellular habit. Charophytes also produce polysaccharide-rich cell walls and in late divergent taxa, pectin plays a critical role in cell adhesion in the multicellular complex. Cell walls are products of coordinated interaction of membrane trafficking, cytoskeletal dynamics and the cells signal transduction machinery responding both to precise internal clocks and external environmental cues. Most often, these activities must be synchronized with the secretion, deposition and remodeling of the polymers of the ECM. Rapid advances in molecular genetics, cell biology and cell wall biochemistry of green algae will soon provide new insights into the evolution and subcellular processes leading to multicellularity. PMID:25477895

  17. Treatment efficacy of algae-based sewage treatment plants.

    PubMed

    Mahapatra, Durga Madhab; Chanakya, H N; Ramachandra, T V

    2013-09-01

    Lagoons have been traditionally used in India for decentralized treatment of domestic sewage. These are cost effective as they depend mainly on natural processes without any external energy inputs. This study focuses on the treatment efficiency of algae-based sewage treatment plant (STP) of 67.65 million liters per day (MLD) capacity considering the characteristics of domestic wastewater (sewage) and functioning of the treatment plant, while attempting to understand the role of algae in the treatment. STP performance was assessed by diurnal as well as periodic investigations of key water quality parameters and algal biota. STP with a residence time of 14.3 days perform moderately, which is evident from the removal of total chemical oxygen demand (COD) (60 %), filterable COD (50 %), total biochemical oxygen demand (BOD) (82 %), and filterable BOD (70 %) as sewage travels from the inlet to the outlet. Furthermore, nitrogen content showed sharp variations with total Kjeldahl nitrogen (TKN) removal of 36 %; ammonium N (NH4-N) removal efficiency of 18 %, nitrate (NO3-N) removal efficiency of 22 %, and nitrite (NO2-N) removal efficiency of 57.8 %. The predominant algae are euglenoides (in facultative lagoons) and chlorophycean members (maturation ponds). The drastic decrease of particulates and suspended matter highlights heterotrophy of euglenoides in removing particulates. PMID:23404546

  18. Uptake and distribution of technetium in several marine algae

    SciTech Connect

    Bonotto, S.; Gerber, G.B.; Garten, C.T. Jr.; Vandecasteele, C.M.; Myttenaere, C.; Van Baelen, J.; Cogneau, M.; van der Ben, D.

    1983-01-01

    The uptake or chemical form of technetium in different marine algae (Acetabularia, Cystoseira, Fucus) has been examined and a simple model to explain the uptake of technetium in the unicellular alga, Acetabularia, has been conceptualized. At low concentrations in the external medium, Acetabularia can rapidly concentrate technetium. Concentration factors in excess of 400 can be attained after a time of about 3 weeks. At higher mass concentrations in the medium, uptake of technetium by Acetabularia becomes saturated resulting in a decreased concentration factor (approximately 10 after 4 weeks). Approximately 69% of the total radioactivity present in /sup 95m/Tc labelled Acetabularia is found in the cell cytosol. In Fucus vesiculosus, labelled with /sup 95m/Tc, a high percentage of technetium is present in soluble ionic forms while approximately 40% is bound, in this brown alga, in proteins and polysaccharides associated with cell walls. In the algal cytosol of Fucus vesiculosus, about 45% of the /sup 95m/Tc appears to be present as anionic TcO/sup -//sub 4/ and the remainder is bound to small molecules. 8 references, 5 figures, 1 table.

  19. Enzyme-Enhanced Extraction of Antioxidant Ingredients from Algae.

    PubMed

    Adalbjrnsson, Bjrn V; Jnsdttir, Rsa

    2015-01-01

    Marine algae are not only a rich source of dietary fibre, proteins, vitamins, and minerals, but also contain a great variety of secondary metabolites with diverse biological activities. Marine macroalgae are a rich source of various natural antioxidants such as polyphenols, especially phlorotannins (made of polyphloroglucinol units) derived from brown algae, which play an important role in preventing lipid peroxidation. In recent years, a number of potent antioxidant compounds have been isolated and identified from different types of edible seaweeds. Extraction methods commonly used for the isolation of antioxidants are based on conventional water or organic solvent extractions. However, recent advances have shown that enzymatic hydrolysis can achieve higher yield of bioactive compounds from algae. Here we describe a method based on enzymatic hydrolysis which both increases yield and decreases cost associated with organic solvents. This method achieves cell wall disruption and breakdown of internal storage components for more effective release of intracellular bioactive compounds. In addition, hydrolysis of proteins produces peptides which may have antioxidant properties, thus enhancing the bioactivity of the algal extract. The method described can be used for production of extracts from red and brown macroalgal species. PMID:26108503

  20. Complete Plastid Genome Sequence of the Brown Alga Undaria pinnatifida

    PubMed Central

    Liu, Tao; Wang, Guoliang; Chi, Shan; Liu, Cui; Wang, Haiyang

    2015-01-01

    In this study, we fully sequenced the circular plastid genome of a brown alga, Undaria pinnatifida. The genome is 130,383 base pairs (bp) in size; it contains a large single-copy (LSC, 76,598 bp) and a small single-copy region (SSC, 42,977 bp), separated by two inverted repeats (IRa and IRb: 5,404 bp). The genome contains 139 protein-coding, 28 tRNA, and 6 rRNA genes; none of these genes contains introns. Organization and gene contents of the U. pinnatifida plastid genome were similar to those of Saccharina japonica. There is a co-linear relationship between the plastid genome of U. pinnatifida and that of three previously sequenced large brown algal species. Phylogenetic analyses of 43 taxa based on 23 plastid protein-coding genes grouped all plastids into a red or green lineage. In the large brown algae branch, U. pinnatifida and S. japonica formed a sister clade with much closer relationship to Ectocarpus siliculosus than to Fucus vesiculosus. For the first time, the start codon ATT was identified in the plastid genome of large brown algae, in the atpA gene of U. pinnatifida. In addition, we found a gene-length change induced by a 3-bp repetitive DNA in ycf35 and ilvB genes of the U. pinnatifida plastid genome. PMID:26426800

  1. Controlling harmful algae blooms using aluminum-modified clay.

    PubMed

    Liu, Yang; Cao, Xihua; Yu, Zhiming; Song, Xiuxian; Qiu, Lixia

    2016-02-15

    The performances of aluminum chloride modified clay (AC-MC), aluminum sulfate modified clay (AS-MC) and polyaluminum chloride modified clay (PAC-MC) in the removal of Aureococcus anophagefferens were compared, and the potential mechanisms were analyzed according to the dispersion medium, suspension pH and clay surface charges. The results showed that AC-MC and AS-MC had better efficiencies in removing A.anophagefferens than PAC-MC. The removal mechanisms of the three modified clays varied. At optimal coagulation conditions, the hydrolysates of AC and AS were mainly monomers, and they transformed into Al(OH)3(am) upon their addition to algae culture, with the primary mechanism being sweep flocculation. The PAC mainly hydrolyzed to the polyaluminum compounds, which remained stable when added to the algae culture, and the flocculation mainly occurred through polyaluminum compounds. The suspension pH significantly influenced the aluminum hydrolysate and affected the flocculation between the modified clay and algae cells. PMID:26763322

  2. Boron-containing organic pigments from a Jurassic red alga

    PubMed Central

    Wolkenstein, Klaus; Gross, Jrgen H.; Falk, Heinz

    2010-01-01

    Organic biomolecules that have retained their basic chemical structures over geological periods (molecular fossils) occur in a wide range of geological samples and provide valuable paleobiological, paleoenvironmental, and geochemical information not attainable from other sources. In rare cases, such compounds are even preserved with their specific functional groups and still occur within the organisms that produced them, providing direct information on the biochemical inventory of extinct organisms and their possible evolutionary relationships. Here we report the discovery of an exceptional group of boron-containing compounds, the borolithochromes, causing the distinct pink coloration of well-preserved specimens of the Jurassic red alga Solenopora jurassica. The borolithochromes are characterized as complicated spiroborates (boric acid esters) with two phenolic moieties as boron ligands, representing a unique class of fossil organic pigments. The chiroptical properties of the pigments unequivocally demonstrate a biogenic origin, at least of their ligands. However, although the borolithochromes originated from a fossil red alga, no analogy with hitherto known present-day red algal pigments was found. The occurrence of the borolithochromes or their possible diagenetic products in the fossil record may provide additional information on the classification and phylogeny of fossil calcareous algae. PMID:20974956

  3. Presence of state transitions in the cryptophyte alga Guillardia theta

    PubMed Central

    Cheregi, Otilia; Kotabová, Eva; Prášil, Ondřej; Schröder, Wolfgang P.; Kaňa, Radek; Funk, Christiane

    2015-01-01

    Plants and algae have developed various regulatory mechanisms for optimal delivery of excitation energy to the photosystems even during fluctuating light conditions; these include state transitions as well as non-photochemical quenching. The former process maintains the balance by redistributing antennae excitation between the photosystems, meanwhile the latter by dissipating excessive excitation inside the antennae. In the present study, these mechanisms have been analysed in the cryptophyte alga Guillardia theta. Photoprotective non-photochemical quenching was observed in cultures only after they had entered the stationary growth phase. These cells displayed a diminished overall photosynthetic efficiency, measured as CO2 assimilation rate and electron transport rate. However, in the logarithmic growth phase G. theta cells redistributed excitation energy via a mechanism similar to state transitions. These state transitions were triggered by blue light absorbed by the membrane integrated chlorophyll a/c antennae, and green light absorbed by the lumenal biliproteins was ineffective. It is proposed that state transitions in G. theta are induced by small re-arrangements of the intrinsic antennae proteins, resulting in their coupling/uncoupling to the photosystems in state 1 or state 2, respectively. G. theta therefore represents a chromalveolate algae able to perform state transitions. PMID:26254328

  4. Toxic effects of decomposing red algae on littoral organisms

    NASA Astrophysics Data System (ADS)

    Eklund, Britta; Svensson, Andreas P.; Jonsson, Conny; Malm, Torleif

    2005-03-01

    Large masses of filamentous red algae of the genera Polysiphonia, Rhodomela, and Ceramium are regularly washed up on beaches of the central Baltic Sea. As the algal masses start to decay, red coloured effluents leak into the water, and this tinge may be traced several hundred meters off shore. In this study, possible toxic effects of these effluents were tested on littoral organisms from different trophic levels. Effects on fertilisation, germination and juvenile survival of the brown seaweed Fucus vesiculosus were investigated, and mortality tests were performed on the crustaceans Artemia salina and Idotea baltica, as well as on larvae and adults of the fish Pomatoschistus microps. Fucus vesiculosus was the most sensitive species of the tested organisms to the red algal extract. The survival of F. vesiculosus recruits was reduced with 50% (LC50) when exposed to a concentration corresponding to 1.7 g l -1 dw red algae. The lethal concentration for I. baltica, A. salina and P. microps were approximately ten times higher. The toxicity to A. salina was reduced if the algal extract was left to decompose during two weeks but the decline in toxicity was not affected by different light or temperature conditions. This study indicates that the filamentous red algae in the central Baltic Sea may produce and release compounds with negative effects on the littoral ecosystem. The effects may be particularly serious for the key species F. vesiculosus, which reproduce in autumn when filamentous red algal blooms are most severe.

  5. Algae (Microcystis and Scenedesmus) absorption spectra and its application on Chlorophyll a retrieval

    NASA Astrophysics Data System (ADS)

    Wu, Di; Chen, Maosi; Wang, Qiao; Gao, Wei

    2013-12-01

    Blue algae and green algae are the dominant phytoplankton groups that contribute to the eutrophication and the water bloom in inland water of China. The absorption coefficients (spectra) of the algae, which do not change with its intrinsic optical characteristics and the observation geometry, are strictly additive quantities. The characteristics of the absorption spectra of the two algae are presented. The pure blue algae and the pure green algae cultured in the laboratory environment are diluted and mixed at ten volume ratios. The Quantitative Filter Technique was applied to measure their absorption spectra. The "hot-ethanol extraction" method was chosen to calculate their concentration of Chlorophyll a. The retrieval algorithm developed in this study extracts the mapping information between each individual alga and their Chlorophyll a concentration via Continuous Wavelet Transform, and retrieves the Chlorophyll a concentration of each alga in their mixture using a trust region optimizer. The results show that the retrieved and the measured Chlorophyll a concentrations of the blue algae and the green algae components in the ten mixture match well with the average relative error of 5.55%.

  6. Sludge-grown algae for culturing aquatic organisms: Part II. Sludge-grown algae as feeds for aquatic organisms

    NASA Astrophysics Data System (ADS)

    Wong, M. H.; Hung, K. M.; Chiu, S. T.

    1996-05-01

    This project investigated the feasibility of using sewage sludge to culture microalgae ( Chlorella-HKBU) and their subsequent usage as feeds for rearing different organisms. Part II of the project evaluated the results of applying the sludge-grown algae to feed Oreochromis mossambicus (fish), Macrobrachium hainenese (shrimp), and Moina macrocopa (cladocera). In general, the yields of the cultivated organisms were unsatisfactory when they were fed the sludge-grown algae directly. The body weights of O. mossambicus and M. macrocopa dropped 21% and 37%, respectively, although there was a slight increase (4.4%) in M. hainenese. However, when feeding the algal-fed cladocerans to fish and shrimp, the body weights of the fish and shrimp were increased 7% and 11% accordingly. Protein contents of the cultivated organisms were comparable to the control diet, although they contained a rather high amount of heavy metals. When comparing absolute heavy metal contents in the cultivated organisms, the following order was observed: alga > cladocera > shrimp, fish > sludge extracts. Bioelimination of heavy metals may account for the decreasing heavy metal concentrations in higher trophic organisms.

  7. Anaerobic Digestion of Algae Biomass to Produce Energy during Wastewater Treatment.

    PubMed

    Peng, Shanshan; Colosi, Lisa M

    2016-01-01

    Water resource recovery facilities (WRRFs) are asked to improve both energy efficiency and nutrient removal efficacy. Integration of algaculture offers several potential synergies that could address these goals, including an opportunity to leverage anaerobic digestion at WRRFs. In this study, bench-scale experiments are used to measure methane yield during co-digestion of Scenedesmus dimorphus or mixed WRRF-grown algae with WRRF biosolids. The results indicate that normalized methane yield decreases with increasing algae content in a manner than can be reasonably well fit using linear regression (R(2) = 67%). It is thus possible to predict methane yield for any mixture of algae and biosolids based on the methane yield of the biosolids alone. Using revised methane yields, the energy return on investment of a typical WRRF increases from 0.53 (without algae) to 0.66 (with algae). Thus, algae-based wastewater treatment may hold promise for improving WRRF energy efficiency without compromising effluent quality. PMID:26803024

  8. Anti-diabetic effects of brown algae derived phlorotannins, marine polyphenols through diverse mechanisms.

    PubMed

    Lee, Seung-Hong; Jeon, You-Jin

    2013-04-01

    Marine algae are popular and abundant food ingredients mainly in Asian countries, and also well known for their health beneficial effects due to the presence of biologically active components. The marine algae have been studied for biologically active components and phlorotannins, marine polyphenols are among them. Among marine algae, brown algae have extensively studied for their potential anti-diabetic activities. Majority of the investigations on phlorotannins derived from brown algae have exhibited their various anti-diabetic mechanisms such as ?-glucosidase and ?-amylase inhibitory effect, glucose uptake effect in skeletal muscle, protein tyrosine phosphatase 1B (PTP 1B) enzyme inhibition, improvement of insulin sensitivity in type 2 diabetic db/db mice, and protective effect against diabetes complication. In this review, we have made an attempt to discuss the various anti-diabetic mechanisms associated with phlorotannins from brown algae that are confined to in vitro and in vivo. PMID:23466874

  9. Green algae and the origins of multicellularity in the plant kingdom.

    PubMed

    Umen, James G

    2014-11-01

    The green lineage of chlorophyte algae and streptophytes form a large and diverse clade with multiple independent transitions to produce multicellular and/or macroscopically complex organization. In this review, I focus on two of the best-studied multicellular groups of green algae: charophytes and volvocines. Charophyte algae are the closest relatives of land plants and encompass the transition from unicellularity to simple multicellularity. Many of the innovations present in land plants have their roots in the cell and developmental biology of charophyte algae. Volvocine algae evolved an independent route to multicellularity that is captured by a graded series of increasing cell-type specialization and developmental complexity. The study of volvocine algae has provided unprecedented insights into the innovations required to achieve multicellularity. PMID:25324214

  10. Natural Abundance 14C Content of Dibutyl Phthalate (DBP) from Three Marine Algae

    PubMed Central

    Namikoshi, Michio; Fujiwara, Takeshi; Nishikawa, Teruaki; Ukai, Kazuyo

    2006-01-01

    Analysis of the natural abundance 14C content of dibutyl phthalate (DBP) from two edible brown algae, Undaria pinnatifida and Laminaria japonica, and a green alga, Ulva sp., revealed that the DBP was naturally produced. The natural abundance 14C content of di-(2-ethylhexyl) phthalate (DEHP) obtained from the same algae was about 50–80% of the standard sample and the 14C content of the petrochemical (industrial) products of DBP and DEHP were below the detection limit.

  11. Evolutionary origins, molecular cloning and expression of carotenoid hydroxylases in eukaryotic photosynthetic algae

    PubMed Central

    2013-01-01

    Background Xanthophylls, oxygenated derivatives of carotenes, play critical roles in photosynthetic apparatus of cyanobacteria, algae, and higher plants. Although the xanthophylls biosynthetic pathway of algae is largely unknown, it is of particular interest because they have a very complicated evolutionary history. Carotenoid hydroxylase (CHY) is an important protein that plays essential roles in xanthophylls biosynthesis. With the availability of 18 sequenced algal genomes, we performed a comprehensive comparative analysis of chy genes and explored their distribution, structure, evolution, origins, and expression. Results Overall 60 putative chy genes were identified and classified into two major subfamilies (bch and cyp97) according to their domain structures. Genes in the bch subfamily were found in 10 green algae and 1 red alga, but absent in other algae. In the phylogenetic tree, bch genes of green algae and higher plants share a common ancestor and are of non-cyanobacterial origin, whereas that of red algae is of cyanobacteria. The homologs of cyp97a/c genes were widespread only in green algae, while cyp97b paralogs were seen in most of algae. Phylogenetic analysis on cyp97 genes supported the hypothesis that cyp97b is an ancient gene originated before the formation of extant algal groups. The cyp97a gene is more closely related to cyp97c in evolution than to cyp97b. The two cyp97 genes were isolated from the green alga Haematococcus pluvialis, and transcriptional expression profiles of chy genes were observed under high light stress of different wavelength. Conclusions Green algae received a ?-xanthophylls biosynthetic pathway from host organisms. Although red algae inherited the pathway from cyanobacteria during primary endosymbiosis, it remains unclear in Chromalveolates. The ?-xanthophylls biosynthetic pathway is a common feature in green algae and higher plants. The origination of cyp97a/c is most likely due to gene duplication before divergence of green algae and higher plants. Protein domain structures and expression analyses in green alga H. pluvialis indicate that various chy genes are in different manners response to light. The knowledge of evolution of chy genes in photosynthetic eukaryotes provided information of gene cloning and functional investigation of chy genes in algae in the future. PMID:23834441

  12. RESPONSES OF MARINE UNICELLULAR ALGAE TO BROMINATED ORGANIC COMPOUNDS IN SIX GROWTH MEDIA

    EPA Science Inventory

    Marine unicellular algae, Skeletonema costatum, Thalassiosira pseudonana, and Chlorella sp., were exposed to the industrial brominated compounds, tetrabromobisphenol A (TBBP), decabromobiphenyloxide (DBBO), hexabromocyclododecane (HBCD), pentabromomethylbenzene (PBMB), pentabromo...

  13. How-to-Do-It: Diatoms: The Ignored Alga in High School Biology.

    ERIC Educational Resources Information Center

    Hungerford, James J.

    1988-01-01

    Provides historical background, descriptions, uses and basis for identification of diatoms. Explains collection, dry-mount cleaning, and preparation procedures of the algae. Cites additional resources. (RT)

  14. Survival and reproduction in some algae under stress conditions.

    PubMed

    Gupta, S; Agrawal, S C

    2007-01-01

    Pithophora oedogonia and Cladophora glomerata survived lowest 60 and 58%, respectively, in June when the pond diurnal water temperature (PDWT) increased to a maximum of 28 degrees C. The lowering of PDWT only by 1 degrees C in July improved survivability of both algae to their almost maximum level of 100 and 96%, respectively. Further lowering of PDWT to 17-22 degrees C in November initiated akinete formation in P. oedogonia. The process of akinete initiation, maturation and germination continued till April when PDWT increased to 20-24 degrees C, but not beyond that in May when PDWT was 21-26 degrees C. By this time, probably all akinetes have germinated in situ, and the alga was entirely vegetative. P. oedogonia population is not synchronous in nature, since during the 5-6-month reproductive season, some filaments were in active vegetative stage, some had akinete initiation, some had completed akinete formation, and some had akinetes germinating. C. glomerata grew dense vegetative in November and initiated (zoo)sporangial primordia formation (to some extent) in February (when PDWT was lowest, viz. 10-14 degrees C) till April. Meanwhile, no (zoo)-sporangial primordia either produced any zoospore or germinated into a germ tube; and all released their cytoplasmic content and died (along with some vegetative cells) with an increase in PDWT to 21-26 degrees C in May. Vaucheria geminata vegetative patches appeared on the soil surface, 2nd week of January by lowering of atmospheric diurnal temperature (ADT) to 9-16 degrees C in the 1st week. The alga started sexual reproduction by the 2nd week of March (when ADT increased to 20-23 degrees C) and completed the process of reproduction by the 1st week of April (when ADT increased to 24-26 degrees C) and died thereafter. P. oedogonia, C. glomerata and V. geminata survived better and longer in submerged conditions than air-exposed (which was true for P. oedogonia and C. glomerata aquatic habitat and also indicated that the soil alga V. geminata could survive to some extent if submerged in rain water). P. oedogonia formed akinetes and C. glomerata (zoo)sporangial primordia only in submerged condition and not when air-exposed on moist soil surface. V. geminata did not complete the life cycle both under submerged and air-exposed conditions. Vegetative survival in P. oedogonia, C. glomerata, V. geminata, Aphanothece pallida, Gloeocapsa atrata, Scytonema millei, Myxosarcina burmensis, Phormidium bohneri, Oscillatoria animalis, O. subbrevis, Lyngbya birgei, L. major, Microcoleus chthonoplastes and Rhizoclonium crassipellitum, reproduction in P. oedogonia, C. glomerata and V. geminata, cell division in A. pallida and G. atrata, heterocyst and false branch formation in S. millei, all, were adversely affected at approximately 28.5 degrees C for t12 h at light intensity of approximately 160 micromol m(-2) s(-1); high intensity does not ameliorate high temperature damage to any algae. The presence of liquid water, than its absence, outside the different algae moderated the severity of heat to some extent but not when the heat was severe. PMID:18450223

  15. Multispectral sorter for rapid, nondestructive optical bioprospecting for algae biofuels

    NASA Astrophysics Data System (ADS)

    Davis, Ryan W.; Wu, Hauwen; Singh, Seema

    2014-03-01

    Microalgal biotechnology is a nascent yet burgeoning field for developing the next generation of sustainable feeds, fuels, and specialty chemicals. Among the issues facing the algae bioproducts industry, the lack of efficient means of cultivar screening and phenotype selection represents a critical hurdle for rapid development and diversification. To address this challenge, we have developed a multi-modal and label-free optical tool which simultaneously assesses the photosynthetic productivity and biochemical composition of single microalgal cells, and provides a means for actively sorting attractive specimen (bioprospecting) based on the spectral readout. The device integrates laser-trapping micro-Raman spectroscopy and pulse amplitude modulated (PAM) fluorometry of microalgal cells in a flow cell. Specifically, the instrument employs a dual-purpose epi-configured IR laser for single-cell trapping and Raman spectroscopy, and a high-intensity VISNIR trans-illumination LED bank for detection of variable photosystem II (PSII) fluorescence. Micro-Raman scatter of single algae cells revealed vibrational modes corresponding to the speciation and total lipid content, as well as other major biochemical pools, including total protein, carbohydrates, and carotenoids. PSII fluorescence dynamics provide a quantitative estimate of maximum photosynthetic efficiency and regulated and non-regulated non-photochemical quenching processes. The combined spectroscopic readouts provide a set of metrics for subsequent optical sorting of the cells by the laser trap for desirable biomass properties, e.g. the combination of high lipid productivity and high photosynthetic yield. Thus the device provides means for rapid evaluation and sorting of algae cultures and environmental samples for biofuels development.

  16. Codon Usage in Higher Plants, Green Algae, and Cyanobacteria 1

    PubMed Central

    Campbell, Wilbur H.; Gowri, G.

    1990-01-01

    Codon usage is the selective and nonrandom use of synonymous codons by an organism to encode the amino acids in the genes for its proteins. During the last few years, a large number of plant genes have been cloned and sequenced, which now permits a meaningful comparison of codon usage in higher plants, algae, and cyanobacteria. For the nuclear and organellar genes of these organisms, a small set of preferred codons are used for encoding proteins. Codon usage is different for each genome type with the variation mainly occurring in choices between codons ending in cytidine (C) or guanosine (G) versus those ending in adenosine (A) or uridine (U). For organellar genomes, chloroplastic and mitochrondrial proteins are encoded mainly with codons ending in A or U. In most cyanobacteria and the nuclei of green algae, proteins are encoded preferentially with codons ending in C or G. Although only a few nuclear genes of higher plants have been sequenced, a clear distinction between Magnoliopsida (dicot) and Liliopsida (monocot) codon usage is evident. Dicot genes use a set of 44 preferred codons with a slight preference for codons ending in A or U. Monocot codon usage is more restricted with an average of 38 codons preferred, which are predominantly those ending in C or G. But two classes of genes can be recognized in monocots. One set of monocot genes uses codons similar to those in dicots, while the other genes are highly biased toward codons ending in C or G with a pattern similar to nuclear genes of green algae. Codon usage is discussed in relation to evolution of plants and prospects for intergenic transfer of particular genes. PMID:16667228

  17. The ecology of viruses that infect eukaryotic algae.

    PubMed

    Short, Steven M

    2012-09-01

    Because viruses of eukaryotic algae are incredibly diverse, sweeping generalizations about their ecology are rare. These obligate parasites infect a range of algae and their diversity can be illustrated by considering that isolates range from small particles with ssRNA genomes to much larger particles with 560?kb dsDNA genomes. Molecular research has also provided clues about the extent of their diversity especially considering that genetic signatures of algal viruses in the environment rarely match cultivated viruses. One general concept in algal virus ecology that has emerged is that algal viruses are very host specific and most infect only certain strains of their hosts; with the exception of viruses of brown algae, evidence for interspecies infectivity is lacking. Although some host-virus systems behave with boom-bust oscillations, complex patterns of intraspecies infectivity can lead to host-virus coexistence obfuscating the role of viruses in host population dynamics. Within the framework of population dynamics, host density dependence is an important phenomenon that influences virus abundances in nature. Variable burst sizes of different viruses also influence their abundances and permit speculations about different life strategies, but as exceptions are common in algal virus ecology, life strategy generalizations may not be broadly applicable. Gaps in knowledge of virus seasonality and persistence are beginning to close and investigations of environmental reservoirs and virus resilience may answer questions about virus inter-annual recurrences. Studies of algal mortality have shown that viruses are often important agents of mortality reinforcing notions about their ecological relevance, while observations of the surprising ways viruses interact with their hosts highlight the immaturity of our understanding. Considering that just two decades ago algal viruses were hardly acknowledged, recent progress affords the optimistic perspective that future studies will provide keys to unlocking our understanding of algal virus ecology specifically, and aquatic ecosystems generally. PMID:22360532

  18. Carotenoid Biosynthesis in the Primitive Red Alga Cyanidioschyzon merolae?

    PubMed Central

    Cunningham, Francis X.; Lee, Hansel; Gantt, Elisabeth

    2007-01-01

    Cyanidioschyzon merolae is considered to be one of the most primitive of eukaryotic photosynthetic organisms. To obtain insights into the origin and evolution of the pathway of carotenoid biosynthesis in eukaryotic plants, the carotenoid content of C. merolae was ascertained, genes encoding enzymes of carotenoid biosynthesis in this unicellular red alga were identified, and the activities of two candidate pathway enzymes of particular interest, lycopene cyclase and ?-carotene hydroxylase, were examined. C. merolae contains perhaps the simplest assortment of chlorophylls and carotenoids found in any eukaryotic photosynthetic organism: chlorophyll a, ?-carotene, and zeaxanthin. Carotenoids with ?-rings (e.g., lutein), found in many other red algae and in green algae and land plants, were not detected, and the lycopene cyclase of C. merolae quite specifically produced only ?-ringed carotenoids when provided with lycopene as the substrate in Escherichia coli. Lycopene ?-ring cyclases from several bacteria, cyanobacteria, and land plants also proved to be high-fidelity enzymes, whereas the structurally related ?-ring cyclases from several plant species were found to be less specific, yielding products with ?-rings as well as ?-rings. C. merolae lacks orthologs of genes that encode the two types of ?-carotene hydroxylase found in land plants, one a nonheme diiron oxygenase and the other a cytochrome P450. A C. merolae chloroplast gene specifies a polypeptide similar to members of a third class of ?-carotene hydroxylases, common in cyanobacteria, but this gene did not produce an active enzyme when expressed in E. coli. The identity of the C. merolae ?-carotene hydroxylase therefore remains uncertain. PMID:17085635

  19. A comparative study of animal erythrocyte agglutinins from marine algae.

    PubMed

    Chiles, T C; Bird, K T

    1989-01-01

    1. Fifteen marine algal species were analyzed for agglutinins to rabbit, sheep and human A, B and O blood group erythrocytes. 2. Protein extracts from all marine algae agglutinated rabbit erythrocytes, whereas twelve and five extracts agglutinated sheep and human erythrocytes, respectively. 3. The highest agglutination titers were consistently observed with rabbit erythrocytes. 4. Dictyota dichotoma strongly agglutinated human B blood group erythrocytes relative to A and O group erythrocytes. 5. Agglutination titer of rabbit erythrocytes by six algal extracts was not inhibited by mono- or polysaccharides, yet was reduced by glycoproteins. PMID:2598625

  20. Green algae as a platform to express therapeutic proteins.

    PubMed

    Lu, Yang; Oyler, George A

    2009-06-01

    Proteins produced by DNA recombinant technology have been playing important roles in modern medicine ever since the first such protein drug was approved by the U.S. Food and Drug Administration about three decades ago. However the inherent high cost of producing recombinant proteins, particularly those produced from mammalian cells, has hampered their broad application. Other protein expression systems that can reduce the cost yet still maintain the high-level therapeutic activities of the recombinant proteins are a top R&D priority. Eukaryotic unicellular green algae cells may provide a good solution to this long-standing challenge. PMID:19772839

  1. A new phlorotannin from the brown alga Ecklonia stolonifera.

    PubMed

    Kang, Hye Sook; Chung, Hae Young; Jung, Jee Hyung; Son, Byeng Wha; Choi, Jae Sue

    2003-08-01

    A new phlorotannin, named eckstolonol (1), was isolated from the EtOAc soluble fraction of the methanolic extract of the brown alga, Ecklonia stolonifera OKAMURA, along with three known phlorotannins, eckol (2), phlorofucofuroeckol A (3), and dieckol (4). The structure of eckstolonol was identified as 5,8,13,14-tetraoxa-pentaphene-1,3,6,9,11-pentaol on the basis of spectroscopic evidence. The new compound was found to be a radical scavenger on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. PMID:12913249

  2. Medicinal effects of phlorotannins from marine brown algae.

    PubMed

    Kim, Se-Kwon; Himaya, S W A

    2011-01-01

    Brown seaweeds are popular and abundant food in East Asia and also well known for their medicinal effects due to presence of active phenolic constituents. Phlorotannins, the major phenolic group of brown algae, have extensively investigated for their vast array of bioactivities such as antioxidant, anti-inflammatory, anticancer, and antidiabetic. They possess promising activity in both in vitro and in vivo systems showing promising potential to further develop as therapeutic agents. In this chapter, attempts have taken to examine and categorize the reports available on active phlorotannins which have shown strong bioactivities. PMID:22054941

  3. Interaction of organic solvents with the green alga Chlorella pyrenoidosa

    SciTech Connect

    Stratton, G.W.; Smith, T.M. )

    1988-06-01

    Solvents are often a component of bioassay systems when water-insoluble toxicants are being tested. These solvents must also be considered as xenobiotics and therefore, as potential toxicants in the bioassay. However, the effects of solvents on the organisms being tested and their possible interaction with the test compound are often overlooked by researchers. The purpose of the present study was to compare the inhibitory effects of six solvents commonly used in pesticide bioassays towards growth of the common green alga Chlorella pyrenoidosa, and to examine the occurrence of solvent-pesticide interactions with this organism.

  4. Systemic chlorellosis, an emerging infection in humans caused by algae.

    PubMed

    Krcmry, V

    2000-08-01

    One hundred and eight cases of human protothecosis occurring over 25 years are reviewed. The most common species isolated was Prototheca wickerhamii, The algae have been isolated from a large number of sites but seem to have low virulence. In the majority of systemic infections there have been few symptoms. Cutaneous manifestations may vary from patient to patient but infections of immunosuppressed patients tend to be more florid. Most cases have been successfully treated by excising the lesion or with antifungals. Most strains are sensitive to 5-fluorocytosine, amphotericin B and the azoles but resistance does occur. PMID:10926448

  5. The role of algae in mine drainage bioremediation

    SciTech Connect

    Davison, J. )

    1990-06-01

    The effect of mine drainage effluent on aquatic ecosystems has been abundantly documented and remediation efforts to data have always been costly and temporary at best. Bioremediation, using natural environmental microbes, to treat acid mine drainage has shown great promise as an affordable, permanent treatment. At Lambda, we used mixatrophic cultures of bacteria, algae, protozoans and fungal groups on four different jobs and it has proven effective. The role of two particular algal groups, the Euglena mutabilis and the Ochramonas sp. are particularly of phycological interest.

  6. Multidimensional electronic spectroscopy of phycobiliproteins from cryptophyte algae

    NASA Astrophysics Data System (ADS)

    Turner, Daniel

    2011-03-01

    We describe new spectroscopic measurements which reveal additional information regarding the observed quantum coherences in proteins extracted from photosynthetic algae. The proteins we investigate are the phycobiliproteins phycoerythrin 545 and phycocyanin 645. Two new avenues have been explored. We describe how changes to the chemical and biological environment impact the quantum coherence present in the 2D electronic correlation spectrum. We also use new multidimensional spectroscopic techniques to reveal insights into the nature of the quantum coherence and the nature of the participating states.

  7. Dancing Volvox: Hydrodynamic Bound States of Swimming Algae

    NASA Astrophysics Data System (ADS)

    Drescher, Knut; Leptos, Kyriacos C.; Tuval, Idan; Ishikawa, Takuji; Pedley, Timothy J.; Goldstein, Raymond E.

    2009-04-01

    The spherical alga Volvox swims by means of flagella on thousands of surface somatic cells. This geometry and its large size make it a model organism for studying the fluid dynamics of multicellularity. Remarkably, when two nearby Volvox colonies swim close to a solid surface, they attract one another and can form stable bound states in which they waltz or minuet around each other. A surface-mediated hydrodynamic attraction combined with lubrication forces between spinning, bottom-heavy Volvox explains the formation, stability, and dynamics of the bound states. These phenomena are suggested to underlie observed clustering of Volvox at surfaces.

  8. Waltzing Volvox/: Orbiting Bound States of Flagellated Multicellular Algae

    NASA Astrophysics Data System (ADS)

    Drescher, K.; Leptos, K.; Pedley, T. J.; Goldstein, R. E.; Ishikawa, T.

    2008-11-01

    The spherical colonial alga Volvox swims by means of flagella on thousands of surface somatic cells. This geometry and its large size makes it a model organism for the fluid dynamics of multicellularity. Remarkably, when two nearby colonies swim close to a solid surface, they are attracted together and can form a stable bound state in which they continuously waltz around each other. A surface-mediated hydrodynamic attraction between colonies combined with the rotational motion of bottom-heavy Volvox are shown to explain the stability and dynamics of the bound state. This phenomenon is suggested to underlie observed clustering of colonies at surfaces.

  9. Properties of a Lipoxygenase in Green Algae (Oscillatoria sp.)

    PubMed Central

    Beneytout, Jean-Louis; Andrianarison, Rivo-Hery; Rakotoarisoa, Zafisolo; Tixier, Marie

    1989-01-01

    A lipoxygenase preparation was obtained from green algae Oscillatoria sp. and was shown to differ from previous described lipoxygenases in the positional specificity and pH characteristics of the dioxygenation reaction. The enzyme had a pH optimum at 8.8 and was inactive at pH 6. Oscillatoria lipoxygenase converted linoleic acid into two products: 13-hydroperoxylinoleic acid (52%) and 9-hydroperoxylinoleic acid (48%). The molecular weight of the enzyme was estimated at 124,000. Esculetin was found to be the best inhibitor of the enzyme activity. PMID:16667027

  10. [Epiphytic algae from Bajo Pepito, Isla Mujeres, Quintana Roo, Mexico].

    PubMed

    Quan-Young, L I; Díaz-Martín, M A; Espinoza-Avalos, J

    2006-06-01

    A total of 96 epiphytic algae species were identified from Bajo Pepito, Quintana Roo, México. 60.4% (58) belonged to the Rhodophyta, 19.79% (19) to the Phaeophyta, 16.6% (16) to the Chlorophyta and 3.1% (3) to the Cyanophyta; 49 species (50.5%) were found only in one month, while Heterosiphonia crispella was found in all of the sampled months. That species provided the largest contribution to the biomass of epiphytes. During January we registered the greater biommass and richness of epiphytes species, coincidently with high values of host species cover and rainfall. PMID:18494302

  11. Multi-scale Characterization of Improved Algae Strains

    SciTech Connect

    Dale, Taraka T.

    2015-04-01

    This report relays the important role biofuels such as algae could have in the energy market. The report cites that problem of crude oil becoming less abundant while the demand for energy continues to rise. There are many benefits of producing energy with biofuels such as fewer carbon emissions as well as less land area to produce the same amount of energy compared to other sources of renewable fuels. One challenge that faces biofuels right now is the cost to produce it is high.

  12. Bioactivities from Marine Algae of the Genus Gracilaria

    PubMed Central

    de Almeida, Cynthia Layse F.; Falcão, Heloina de S.; Lima, Gedson R. de M.; Montenegro, Camila de A.; Lira, Narlize S.; de Athayde-Filho, Petrônio F.; Rodrigues, Luis C.; de Souza, Maria de Fátima V.; Barbosa-Filho, José M.; Batista, Leônia M.

    2011-01-01

    Seaweeds are an important source of bioactive metabolites for the pharmaceutical industry in drug development. Many of these compounds are used to treat diseases like cancer, acquired immune-deficiency syndrome (AIDS), inflammation, pain, arthritis, as well as viral, bacterial, and fungal infections. This paper offers a survey of the literature for Gracilaria algae extracts with biological activity, and identifies avenues for future research. Nineteen species of this genus that were tested for antibacterial, antiviral, antifungal, antihypertensive, cytotoxic, spermicidal, embriotoxic, and anti-inflammatory activities are cited from the 121 references consulted. PMID:21845096

  13. Polyploidy of Endosymbiotically Derived Genomes in Complex Algae

    PubMed Central

    Hirakawa, Yoshihisa; Ishida, Ken-Ichiro

    2014-01-01

    Chlorarachniophyte and cryptophyte algae have complex plastids that were acquired by the uptake of a green or red algal endosymbiont via secondary endosymbiosis. The plastid is surrounded by four membranes, and a relict nucleus, called the nucleomorph, remains in the periplastidal compartment that is the remnant cytoplasm of the endosymbiont. Thus, these two algae possess four different genomes in a cell: Nuclear, nucleomorph, plastid, and mitochondrial. Recently, sequencing of the nuclear genomes of the chlorarachniophyte Bigelowiella natans and the cryptophyte Guillardia theta has been completed, and all four genomes have been made available. However, the copy number of each genome has never been investigated. It is important to know the actual DNA content of each genome, especially the highly reduced nucleomorph genome, for studies on genome evolution. In this study, we calculated genomic copy numbers in B. natans and G. theta using a real-time quantitative polymerase chain reaction approach. The nuclear genomes were haploid in both species, whereas the nucleomorph genomes were estimated to be diploid and tetraploid, respectively. Mitochondria and plastids contained a large copy number of genomic DNA in each cell. In the secondary endosymbioses of chlorarachniophytes and cryptophytes, the endosymbiont nuclear genomes were highly reduced in size and in the number of coding genes, whereas the chromosomal copy number was increased, as in bacterial endosymbiont genomes. This suggests that polyploidization is a general characteristic of highly reduced genomes in broad prokaryotic and eukaryotic endosymbionts. PMID:24709562

  14. Balamuthia mandrillaris: in vitro interactions with selected protozoa and algae.

    PubMed

    Tapia, Jos L; Torres, Benjamin Nogueda; Visvesvara, Govinda S

    2013-01-01

    Although Balamuthia mandrillaris was identified more than two decades ago as an agent of fatal granulomatous encephalitis in humans and other animals, little is known about its ecological niche, biological behavior in the environment, food preferences and predators, if any. When infecting humans or other animals, Balamuthia feeds on tissues; and in vitro culture, it feeds on mammalian cells (monkey kidney cells, human lung fibroblasts, and human microvascular endothelial cells). According to recent reports, it is believed that Balamuthia feeds on small amebae, for example, Acanthamoeba that are present in its ecological niche. To test this hypothesis, we associated Balamuthia on a one-on-one basis with selected protozoa and algae. We videotaped the behavior of Balamuthia in the presence of a potential prey, its ability to hunt and attack its food, and the time required to eat and cause damage to the target cell by direct contact. We found that B. mandrillaris ingested trophozoites of Naegleria fowleri, Naegleria gruberi, Acanthamoeba spp., Trypanosoma cruzi epimastigotes, Toxoplasma gondii tachyzoites, and Giardia. However, it did not feed on Acanthamoeba cysts or algae. Balamuthia caused cytolysis of T. cruzi epimastigotes and T. gondii tachyzoites by direct contact. Balamuthia trophozoites and cysts were, however, eaten by Paramecium sp. PMID:23790262

  15. Drift algae reduce foraging efficiency of juvenile flatfish

    NASA Astrophysics Data System (ADS)

    Nordstrm, Marie; Booth, Dale M.

    2007-11-01

    Although flatfish species utilise a wide range of habitats as adults, several species are confined to a very limited habitat as juveniles. Recruitment levels are dependent on the quality and quantity of these nursery areas and changes therein. In the Baltic Sea, these shallow environments are often subject to influxes of drifting macroalgae, which add structure to otherwise bare sandy substrate. Structure, such as vegetation, alters predator-prey interactions of a wide range of fauna and in an array of marine, freshwater, and terrestrial systems. The aim of our study was to assess the inhibition potential of drifting macroalgae on the foraging efficiency of juvenile flatfish (young of the year Scophthalmus maximus L., young of the year- and group 1 + Platichthys flesus L.) through a series of microcosm experiments. Our results show that foraging success is restricted by drift algae as predation efficiency of all predator species and size classes was negatively affected by the presence of macroalgae. Overall, there was a reduction in predation success by 80 12% due to structural effects and/or the induced changes in water chemistry associated with the algae. Flatfish depend on shallow sandy areas as feeding and nursery grounds during their juvenile stage and frequently occurring macroalgal assemblages drastically change the features of the otherwise bare substrate, setting the stage for small-scale, localised processes potentially affecting population dynamics.

  16. Unlocking nature's treasure-chest: screening for oleaginous algae.

    PubMed

    Slocombe, Stephen P; Zhang, QianYi; Ross, Michael; Anderson, Avril; Thomas, Naomi J; Lapresa, Ángela; Rad-Menéndez, Cecilia; Campbell, Christine N; Black, Kenneth D; Stanley, Michele S; Day, John G

    2015-01-01

    Micro-algae synthesize high levels of lipids, carbohydrates and proteins photoautotrophically, thus attracting considerable interest for the biotechnological production of fuels, environmental remediation, functional foods and nutraceuticals. Currently, only a few micro-algae species are grown commercially at large-scale, primarily for "health-foods" and pigments. For a range of potential products (fuel to pharma), high lipid productivity strains are required to mitigate the economic costs of mass culture. Here we present a screen concentrating on marine micro-algal strains, which if suitable for scale-up would minimise competition with agriculture for water. Mass-Spectrophotometric analysis (MS) of nitrogen (N) and carbon (C) was subsequently validated by measurement of total fatty acids (TFA) by Gas-Chromatography (GC). This identified a rapid and accurate screening strategy based on elemental analysis. The screen identified Nannochloropsis oceanica CCAP 849/10 and a marine isolate of Chlorella vulgaris CCAP 211/21A as the best lipid producers. Analysis of C, N, protein, carbohydrate and Fatty Acid (FA) composition identified a suite of strains for further biotechnological applications e.g. Dunaliella polymorpha CCAP 19/14, significantly the most productive for carbohydrates, and Cyclotella cryptica CCAP 1070/2, with utility for EPA production and N-assimilation. PMID:26202369

  17. Bactericidal activity of phlorotannins from the brown alga Ecklonia kurome.

    PubMed

    Nagayama, Koki; Iwamura, Yoshitoshi; Shibata, Toshiyuki; Hirayama, Izumi; Nakamura, Takashi

    2002-12-01

    The bactericidal activity of phlorotannins from brown algae against food-borne pathogenic bacteria (25 strains), methicillin-resistant Staphylococcus aureus (MRSA) (nine strains) and Streptococcus pyogenes (one strain) was examined and compared with that of catechins. In addition, the effect of the oral administration of phlorotannins on mice was investigated. Phlorotannins, which are oligomers of phloroglucinol, were extracted from thalli of the brown alga Ecklonia kurome and prepared by silicic acid chromatography. The bactericidal activity of polyphenols was determined using a broth microdilution method. Of the bacteria tested, Campylobacter spp. were the most susceptible to the phlorotannins. The MBCs of the crude phlorotannins, dieckol and 8,8'-bieckol (hexamers), and that of epigallocatechin gallate (EGCG) against Campylobacter jejuni were 50 mg/L, 0.03 micromol/mL and 0.03 micromol/mL, respectively. On the whole, the bactericidal effects of the phlorotannins were more pronounced than those of the catechins. The phlorotannins were as effective against MRSA as against the other bacteria tested. At twice the MBCs, all Vibrio parahaemolyticus were killed within 0.5-2 h. However, at the same concentration, catechins showed little bactericidal activity within 4 h. No effect on mice was observed with oral administration of the phlorotannins under the conditions tested. PMID:12461009

  18. Productivity of sea ice algae: In situ vs. incubator methods

    NASA Astrophysics Data System (ADS)

    Smith, Ralph E. H.; Herman, Alex W.

    1991-07-01

    Algae of annual sea ice in the high Arctic (Resolute Passage, N.W.T.) gave little evidence of serious photosynthetic impairment during the seasonal decline of the bottom ice bloom when measured in a light-gradient incubator using a popular technique. Measurements made in situ with a novel sampling and incubating device, however, yielded much lower production rates than expected from the incubator measurements. Maximum assimilation numbers averaged 0.223 mgCmgChl a-1h -1 in incubator experiments but only 0.018 in situ, while photosynthetic efficiency averaged 0.0137 and 0.0069 [mgCmgChl a-1 h -1][ ?mol photonsm -2s -1] -1 in the incubator and in sutu, respectively. Problems of tracer diffusion, temperature differentials and extracellullar release of dissolved organic carbon can help explain the discrepancy, but differences in the spectral availability of light (PUR) between incubator and estimated in situ conditions would tend to worsen the disagreement. Bottom ice algae appear to remain viable and potentially productive during the decline of the bloom, but may achieve relatively little production in situ, depending on which technique for measuring production is considered most accurate.

  19. Marine Algae: a Source of Biomass for Biotechnological Applications.

    PubMed

    Stengel, Dagmar B; Connan, Solène

    2015-01-01

    Biomass derived from marine microalgae and macroalgae is globally recognized as a source of valuable chemical constituents with applications in the agri-horticultural sector (including animal feeds and health and plant stimulants), as human food and food ingredients as well as in the nutraceutical, cosmeceutical, and pharmaceutical industries. Algal biomass supply of sufficient quality and quantity however remains a concern with increasing environmental pressures conflicting with the growing demand. Recent attempts in supplying consistent, safe and environmentally acceptable biomass through cultivation of (macro- and micro-) algal biomass have concentrated on characterizing natural variability in bioactives, and optimizing cultivated materials through strain selection and hybridization, as well as breeding and, more recently, genetic improvements of biomass. Biotechnological tools including metabolomics, transcriptomics, and genomics have recently been extended to algae but, in comparison to microbial or plant biomass, still remain underdeveloped. Current progress in algal biotechnology is driven by an increased demand for new sources of biomass due to several global challenges, new discoveries and technologies available as well as an increased global awareness of the many applications of algae. Algal diversity and complexity provides significant potential provided that shortages in suitable and safe biomass can be met, and consumer demands are matched by commercial investment in product development. PMID:26108496

  20. Interest of dynamic tests in acute ecotoxicity assessment in algae

    SciTech Connect

    Jouany, J.M.; Ferard, J.F.; Vasseur, P.; Gea, J.; Truhaut, R.; Rast, C.

    1983-04-01

    Sorption of toxics by algae may be important and occurs very early. Thus, a decrease of the experimental toxic concentrations in the medium results in understating toxicity when tests are conducted under static conditions. In this work, two different methods of exposure of algae (Chlorella vulgaris) are studied, the static test and the pseudodynamic test. Acute effects (biological and analytical effects) of inorganic compounds (Cu/sup 2 +/, Cd/sup 2 +/, Pb/sup 2 +/, Cr/sup 6 +/) have been evaluated for 96 hr of exposure; in each case, IC50 is much lower in the dynamic condition than in the static one. The percentage of reduction varies from 55 to 75% after 96 hr. Accumulation of metal by chlorellae is greater when testing by the pseudodynamic way, with Cu/sup 2 +/ and Pb/sup 2 +/. But in the case of Cd/sup 2 +/ and Cr/sup 6 +/, the concentration factors are similar in the two kinds of exposure. These results point out the advantage of the pseudodynamic test, of which the methodology is very easy, for a more realistic assessment of acute ecotoxicity in these organisms.

  1. Halophytes, Algae, and Bacteria Food and Fuel Feedstocks

    NASA Technical Reports Server (NTRS)

    Hendricks, R. C.; Bushnell, D. M.

    2009-01-01

    The constant, increasing demand for energy, freshwater, and food stresses our ability to meet these demands within reasonable cost and impact on climate while sustaining quality of life. This environmental Triangle of Conflicts between energy, food, and water--while provoked by anthropogenic monetary and power struggles--can be resolved through an anthropogenic paradigm shift in how we produce and use energy, water, and food. With world population (6.6 billion) projected to increase 40 percent in 40 to 60 yr, proper development of saline agriculture and aquaculture is required, as 43 percent of the Earth's landmass is arid or semi-arid and 97 percent of the Earth's water is seawater. In light of this, we seek fuel alternatives in plants that thrive in brackish and saltwater with the ability to survive in arid lands. The development and application of these plants (halophytes) become the primary focus. Herein we introduce some not-so-familiar halophytes and present a few of their benefits, cite a few research projects (including some on the alternatives algae and bacteria), and then set theoretical limits on biomass production followed by projections in terms of world energy demands. Based on diverse arid lands with a total size equivalent to the Sahara Desert (8.6(exp 8) ha, or 2.1(exp 9) acres), these projections show that halophyte agriculture and algae systems can provide for the projected world energy demand.

  2. Photosynthetic Hydrogen and Oxygen Production by Green Algae

    SciTech Connect

    Greenbaum, E.; Lee, J.W.

    1999-08-22

    Photosynthesis research at Oak Ridge National Laboratory is focused on hydrogen and oxygen production by green algae in the context of its potential as a renewable fuel and chemical feed stock. Beginning with its discovery by Gaffron and Rubin in 1942, motivated by curiosity-driven laboratory research, studies were initiated in the early 1970s that focused on photosynthetic hydrogen production from an applied perspective. From a scientific and technical point of view, current research is focused on optimizing net thermodynamic conversion efficiencies represented by the Gibbs Free Energy of molecular hydrogen. The key research questions of maximizing hydrogen and oxygen production by light-activated water splitting in green algae are: (1) removing the oxygen sensitivity of algal hydrogenases; (2) linearizing the light saturation curves of hotosynthesis throughout the entire range of terrestrial solar irradiance-including the role of bicarbonate and carbon dioxide in optimization of photosynthetic electron transpor;t and (3) constructing real-world bioreactors, including the generation of hydrogen and oxygen against workable back pressures of the photoproduced gases.

  3. Photosynthetic hydrogen and oxygen production by green algae

    SciTech Connect

    Greenbaum, E.; Lee, J.W.

    1997-12-31

    An overview of photosynthetic hydrogen and oxygen production by green algae in the context of its potential as a renewable chemical feed stock and energy carrier is presented. Beginning with its discovery by Gaffron and Rubin in 1942, motivated by curiosity-driven laboratory research, studies were initiated in the early 1970s that focused on photosynthetic hydrogen production from an applied perspective. From a scientific and technical point of view, current research is focused on optimizing net thermodynamic conversion efficiencies represented by the Gibbs Free Energy of molecular hydrogen. The key research questions of maximizing hydrogen and oxygen production by light-activated water splitting in green algae are (1) removing the oxygen sensitivity of algal hydrogenases; (2) linearizing the light saturation curves of photosynthesis throughout the entire range of terrestrial solar irradiance--including the role of bicarbonate and carbon dioxide in optimization of photosynthetic electron transport and (3) the minimum number of light reactions that are required to split water to elemental hydrogen and oxygen. Each of these research topics is being actively addressed by the photobiological hydrogen research community.

  4. Monoclonal Antibodies Directed to Fucoidan Preparations from Brown Algae

    PubMed Central

    Torode, Thomas A.; Marcus, Susan E.; Jam, Murielle; Tonon, Thierry; Blackburn, Richard S.; Hervé, Cécile; Knox, J. Paul

    2015-01-01

    Cell walls of the brown algae contain a diverse range of polysaccharides with useful bioactivities. The precise structures of the sulfated fucan/fucoidan group of polysaccharides and their roles in generating cell wall architectures and cell properties are not known in detail. Four rat monoclonal antibodies, BAM1 to BAM4, directed to sulfated fucan preparations, have been generated and used to dissect the heterogeneity of brown algal cell wall polysaccharides. BAM1 and BAM4, respectively, bind to a non-sulfated epitope and a sulfated epitope present in the sulfated fucan preparations. BAM2 and BAM3 identified additional distinct epitopes present in the fucoidan preparations. All four epitopes, not yet fully characterised, occur widely within the major brown algal taxonomic groups and show divergent distribution patterns in tissues. The analysis of cell wall extractions and fluorescence imaging reveal differences in the occurrence of the BAM1 to BAM4 epitopes in various tissues of Fucus vesiculosus. In Ectocarpus subulatus, a species closely related to the brown algal model Ectocarpus siliculosus, the BAM4 sulfated epitope was modulated in relation to salinity levels. This new set of monoclonal antibodies will be useful for the dissection of the highly complex and yet poorly resolved sulfated polysaccharides in the brown algae in relation to their ecological and economic significance. PMID:25692870

  5. A new route for synthesis of dimethylsulphoniopropionate in marine algae.

    PubMed

    Gage, D A; Rhodes, D; Nolte, K D; Hicks, W A; Leustek, T; Cooper, A J; Hanson, A D

    1997-06-26

    The 3-dimethylsulphoniopropionate (DMSP) produced by marine algae is the main biogenic precursor of atmospheric dimethylsulphide (DMS). This biogenic DMS, formed by bacterial and algal degradation of DMSP, contributes about 1.5 x 10(13) g of sulphur to the atmosphere annually, and plays a major part in the global sulphur cycle, in cloud formation and potentially in climate regulation. Although DMSP biosynthesis has been partially elucidated in a higher plant, nothing is known about how algae make DMSP except that the whole molecule is derived from methionine. Here we use in vivo isotope labelling to demonstrate that DMSP synthesis in the green macroalga Enteromorpha intestinalis proceeds by a route entirely distinct from that in higher plants. From methionine, the steps are transamination, reduction and S-methylation to give the novel sulphonium compound 4-dimethylsulphonio-2-hydroxybutyrate (DMSHB), which is oxidatively decarboxylated to DMSP. The key intermediate DMSHB was also identified in three diverse phytoplankton species, indicating that the same pathway operates in other algal classes that are important sources of DMS. The fact that a transamination initiates this pathway could help explain how algal DMSP (and thereby DMS) production is enhanced by nitrogen deficiency. PMID:9202120

  6. Antiprotozoal, antimycobacterial and cytotoxic potential of some british green algae.

    PubMed

    Spavieri, Jasmine; Kaiser, Marcel; Casey, Rosalyn; Hingley-Wilson, Suzie; Lalvani, Ajit; Blunden, Gerald; Tasdemir, Deniz

    2010-07-01

    In the continuation of our search for natural sources for antiprotozoal and antitubercular molecules, we have screened the crude extracts of four green marine algae (Cladophora rupestris, Codium fragile ssp. tomentosoides, Ulva intestinalis and Ulva lactuca) collected from the Dorset area of England. Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Leishmania donovani and Mycobacterium tuberculosis were used as test organisms in the in vitro assays. The selective toxicity of the extracts was also determined toward mammalian skeletal myoblast (L6) cells. The crude seaweed extracts had no activity against M. tuberculosis, but showed antiprotozoal activity against at least two protozoan species. All algal extracts were active against T. brucei rhodesiense, with C. rupestris being the most potent one (IC(50) value 3.7 microg/ml), whilst only C. rupestris and U. lactuca had moderate trypanocidal activity against T. cruzi (IC(50) values 80.8 and 34.9 microg/ml). Again, all four extracts showed leishmanicidal activity with IC(50) values ranging between 12.0 and 20.2 microg/ml. None of the extracts showed cytotoxicity toward L6 cells, indicating that their antiprotozoal activity is specific. This is the first study reporting antiprotozoal and antimycobacterial activity of British marine algae. PMID:19960429

  7. Solar-driven hydrogen production in green algae.

    PubMed

    Burgess, Steven J; Tamburic, Bojan; Zemichael, Fessehaye; Hellgardt, Klaus; Nixon, Peter J

    2011-01-01

    The twin problems of energy security and global warming make hydrogen an attractive alternative to traditional fossil fuels with its combustion resulting only in the release of water vapor. Biological hydrogen production represents a renewable source of the gas and can be performed by a diverse range of microorganisms from strict anaerobic bacteria to eukaryotic green algae. Compared to conventional methods for generating H(2), biological systems can operate at ambient temperatures and pressures without the need for rare metals and could potentially be coupled to a variety of biotechnological processes ranging from desalination and waste water treatment to pharmaceutical production. Photobiological hydrogen production by microalgae is particularly attractive as the main inputs for the process (water and solar energy) are plentiful. This chapter focuses on recent developments in solar-driven H(2) production in green algae with emphasis on the model organism Chlamydomonas reinhardtii. We review the current methods used to achieve sustained H(2) evolution and discuss possible approaches to improve H(2) yields, including the optimization of culturing conditions, reducing light-harvesting antennae and targeting auxiliary electron transport and fermentative pathways that compete with the hydrogenase for reductant. Finally, industrial scale-up is discussed in the context of photobioreactor design and the future prospects of the field are considered within the broader context of a biorefinery concept. PMID:21807246

  8. Chemical mediation of coral larval settlement by crustose coralline algae

    PubMed Central

    Tebben, J.; Motti, C. A; Siboni, Nahshon; Tapiolas, D. M.; Negri, A. P.; Schupp, P. J.; Kitamura, Makoto; Hatta, Masayuki; Steinberg, P. D.; Harder, T.

    2015-01-01

    The majority of marine invertebrates produce dispersive larvae which, in order to complete their life cycles, must attach and metamorphose into benthic forms. This process, collectively referred to as settlement, is often guided by habitat-specific cues. While the sources of such cues are well known, the links between their biological activity, chemical identity, presence and quantification in situ are largely missing. Previous work on coral larval settlement in vitro has shown widespread induction by crustose coralline algae (CCA) and in particular their associated bacteria. However, we found that bacterial biofilms on CCA did not initiate ecologically realistic settlement responses in larvae of 11 hard coral species from Australia, Guam, Singapore and Japan. We instead found that algal chemical cues induce identical behavioral responses of larvae as per live CCA. We identified two classes of CCA cell wall-associated compounds – glycoglycerolipids and polysaccharides – as the main constituents of settlement inducing fractions. These algae-derived fractions induce settlement and metamorphosis at equivalent concentrations as present in CCA, both in small scale laboratory assays and under flow-through conditions, suggesting their ability to act in an ecologically relevant fashion to steer larval settlement of corals. Both compound classes were readily detected in natural samples. PMID:26042834

  9. Marine algae and land plants share conserved phytochrome signaling systems.

    PubMed

    Duanmu, Deqiang; Bachy, Charles; Sudek, Sebastian; Wong, Chee-Hong; Jimnez, Valeria; Rockwell, Nathan C; Martin, Shelley S; Ngan, Chew Yee; Reistetter, Emily N; van Baren, Marijke J; Price, Dana C; Wei, Chia-Lin; Reyes-Prieto, Adrian; Lagarias, J Clark; Worden, Alexandra Z

    2014-11-01

    Phytochrome photosensors control a vast gene network in streptophyte plants, acting as master regulators of diverse growth and developmental processes throughout the life cycle. In contrast with their absence in known chlorophyte algal genomes and most sequenced prasinophyte algal genomes, a phytochrome is found in Micromonas pusilla, a widely distributed marine picoprasinophyte (<2 m cell diameter). Together with phytochromes identified from other prasinophyte lineages, we establish that prasinophyte and streptophyte phytochromes share core light-input and signaling-output domain architectures except for the loss of C-terminal response regulator receiver domains in the streptophyte phytochrome lineage. Phylogenetic reconstructions robustly support the presence of phytochrome in the common progenitor of green algae and land plants. These analyses reveal a monophyletic clade containing streptophyte, prasinophyte, cryptophyte, and glaucophyte phytochromes implying an origin in the eukaryotic ancestor of the Archaeplastida. Transcriptomic measurements reveal diurnal regulation of phytochrome and bilin chromophore biosynthetic genes in Micromonas. Expression of these genes precedes both light-mediated phytochrome redistribution from the cytoplasm to the nucleus and increased expression of photosynthesis-associated genes. Prasinophyte phytochromes perceive wavelengths of light transmitted farther through seawater than the red/far-red light sensed by land plant phytochromes. Prasinophyte phytochromes also retain light-regulated histidine kinase activity lost in the streptophyte phytochrome lineage. Our studies demonstrate that light-mediated nuclear translocation of phytochrome predates the emergence of land plants and likely represents a widespread signaling mechanism in unicellular algae. PMID:25267653

  10. Marine algae and land plants share conserved phytochrome signaling systems

    PubMed Central

    Duanmu, Deqiang; Bachy, Charles; Sudek, Sebastian; Wong, Chee-Hong; Jimnez, Valeria; Rockwell, Nathan C.; Martin, Shelley S.; Ngan, Chew Yee; Reistetter, Emily N.; van Baren, Marijke J.; Price, Dana C.; Wei, Chia-Lin; Reyes-Prieto, Adrian; Lagarias, J. Clark; Worden, Alexandra Z.

    2014-01-01

    Phytochrome photosensors control a vast gene network in streptophyte plants, acting as master regulators of diverse growth and developmental processes throughout the life cycle. In contrast with their absence in known chlorophyte algal genomes and most sequenced prasinophyte algal genomes, a phytochrome is found in Micromonas pusilla, a widely distributed marine picoprasinophyte (<2 m cell diameter). Together with phytochromes identified from other prasinophyte lineages, we establish that prasinophyte and streptophyte phytochromes share core light-input and signaling-output domain architectures except for the loss of C-terminal response regulator receiver domains in the streptophyte phytochrome lineage. Phylogenetic reconstructions robustly support the presence of phytochrome in the common progenitor of green algae and land plants. These analyses reveal a monophyletic clade containing streptophyte, prasinophyte, cryptophyte, and glaucophyte phytochromes implying an origin in the eukaryotic ancestor of the Archaeplastida. Transcriptomic measurements reveal diurnal regulation of phytochrome and bilin chromophore biosynthetic genes in Micromonas. Expression of these genes precedes both light-mediated phytochrome redistribution from the cytoplasm to the nucleus and increased expression of photosynthesis-associated genes. Prasinophyte phytochromes perceive wavelengths of light transmitted farther through seawater than the red/far-red light sensed by land plant phytochromes. Prasinophyte phytochromes also retain light-regulated histidine kinase activity lost in the streptophyte phytochrome lineage. Our studies demonstrate that light-mediated nuclear translocation of phytochrome predates the emergence of land plants and likely represents a widespread signaling mechanism in unicellular algae. PMID:25267653

  11. Biotransformation of arsenic by a Yellowstone thermoacidophilic eukaryotic alga

    PubMed Central

    Qin, Jie; Lehr, Corinne R.; Yuan, Chungang; Le, X. Chris; McDermott, Timothy R.; Rosen, Barry P.

    2009-01-01

    Arsenic is the most common toxic substance in the environment, ranking first on the Superfund list of hazardous substances. It is introduced primarily from geochemical sources and is acted on biologically, creating an arsenic biogeocycle. Geothermal environments are known for their elevated arsenic content and thus provide an excellent setting in which to study microbial redox transformations of arsenic. To date, most studies of microbial communities in geothermal environments have focused on Bacteria and Archaea, with little attention to eukaryotic microorganisms. Here, we show the potential of an extremophilic eukaryotic alga of the order Cyanidiales to influence arsenic cycling at elevated temperatures. Cyanidioschyzon sp. isolate 5508 oxidized arsenite [As(III)] to arsenate [As(V)], reduced As(V) to As(III), and methylated As(III) to form trimethylarsine oxide (TMAO) and dimethylarsenate [DMAs(V)]. Two arsenic methyltransferase genes, CmarsM7 and CmarsM8, were cloned from this organism and demonstrated to confer resistance to As(III) in an arsenite hypersensitive strain of Escherichia coli. The 2 recombinant CmArsMs were purified and shown to transform As(III) into monomethylarsenite, DMAs(V), TMAO, and trimethylarsine gas, with a Topt of 60–70 °C. These studies illustrate the importance of eukaryotic microorganisms to the biogeochemical cycling of arsenic in geothermal systems, offer a molecular explanation for how these algae tolerate arsenic in their environment, and provide the characterization of algal methyltransferases. PMID:19276121

  12. Marine algae and land plants share conserved phytochrome signaling systems

    SciTech Connect

    Duanmu, Deqiang; Bachy, Charles; Sudek, Sebastian; Wong, Chee -Hong; Jimenez, Valeria; Rockwell, Nathan C.; Martin, Shelley S.; Ngan, Chew Yee; Reistetter, Emily N.; van Baren, Marijke J.; Price, Dana C.; Wei, Chia -Lin; Reyes-Prieto, Adrian; Lagarias, J. Clark; Worden, Alexandra Z.

    2014-09-29

    Phytochrome photosensors control a vast gene network in streptophyte plants, acting as master regulators of diverse growth and developmental processes throughout the life cycle. In contrast with their absence in known chlorophyte algal genomes and most sequenced prasinophyte algal genomes, a phytochrome is found in Micromonas pusilla, a widely distributed marine picoprasinophyte (<2 µm cell diameter). Together with phytochromes identified from other prasinophyte lineages, we establish that prasinophyte and streptophyte phytochromes share core light-input and signaling-output domain architectures except for the loss of C-terminal response regulator receiver domains in the streptophyte phytochrome lineage. Phylogenetic reconstructions robustly support the presence of phytochrome in the common progenitor of green algae and land plants. These analyses reveal a monophyletic clade containing streptophyte, prasinophyte, cryptophyte, and glaucophyte phytochromes implying an origin in the eukaryotic ancestor of the Archaeplastida. Transcriptomic measurements reveal diurnal regulation of phytochrome and bilin chromophore biosynthetic genes in Micromonas. The expression of these genes precedes both light-mediated phytochrome redistribution from the cytoplasm to the nucleus and increased expression of photosynthesis-associated genes. Prasinophyte phytochromes perceive wavelengths of light transmitted farther through seawater than the red/far-red light sensed by land plant phytochromes. Prasinophyte phytochromes also retain light-regulated histidine kinase activity lost in the streptophyte phytochrome lineage. Our studies demonstrate that light-mediated nuclear translocation of phytochrome predates the emergence of land plants and likely represents a widespread signaling mechanism in unicellular algae.

  13. Health benefit of fucosterol from marine algae: a review.

    PubMed

    Abdul, Qudeer Ahmed; Choi, Ran Joo; Jung, Hyun Ah; Choi, Jae Sue

    2016-04-01

    Seaweeds belong to a group of marine plants known as algae, which are consumed as sea vegetables in several Asian countries. Recent studies have focused on the biological and pharmacological activities of seaweeds and their highly bioactive secondary metabolites because of their potential in the development of new pharmaceutical agents. Although several varieties of bioactive novel compounds such as phlorotannins, diterpenes and polysaccharides from seaweeds have already been well scrutinized, fucosterol as a phytosterol still needs to reinvent itself. Fucosterol (24-ethylidene cholesterol) is a sterol that can be isolated from algae, seaweed and diatoms. Fucosterol exhibits various biological therapeutics, including anticancer, antidiabetic, antioxidant, hepatoprotective, antihyperlipidemic, antifungal, antihistaminic, anticholinergic, antiadipogenic, antiphotodamaging, anti-osteoporotic, blood cholesterol reducing, blood vessel thrombosis preventive and butyrylcholinesterase inhibitory activities. In this review, we address some potential approaches for arbitrating novel fucosterol biologics in the medical field, focusing on the selection of personalized drug candidates and highlighting the challenges and opportunities regarding medical breakthroughs. We also highlight recent advances made in the design of this novel compound, as the significant health benefits from using these optimized applications apply to the nutraceutical and pharmaceutical fields. © 2015 Society of Chemical Industry. PMID:26455344

  14. Extracts of marine algae show inhibitory activity against osteoclast differentiation.

    PubMed

    Koyama, Tomoyuki

    2011-01-01

    Osteoclasts are multinucleated cells that play a crucial role in bone resorption. The imbalance between bone resorption and bone formation results in osteoporosis. Therefore, substances that can suppress osteoclast formation are potential candidate materials for drug development or functional foods. There have been reports that extracts or purified compounds from marine micro- and macroalgae can suppress osteoclast differentiation. Symbioimine, isolated from the cultured dinoflagellate Symbiodinium sp., had suppressive effects against osteoclast differentiation in osteoclast-like cells. Norzoanthamine, isolated from the colonial zoanthid Zoanthas sp., has been shown to have antiosteoporosis activity in ovariectomized mice. With regard to marine extracts, the fucoxanthin-rich component from brown algae has been shown to have suppressive effects against osteoclast differentiation. An extract of Sargassum fusiforme has recently been shown to have antiosteoporosis activity. This extract suppressed both osteoclast differentiation and accelerated osteoblast formation in separate in vitro experiments. It also showed antiosteoporosis activity in ovariectomized mice by regulating the balance between bone resorption and bone formation. These marine algae and their extracts may be sources of marine medicinal foods for the prevention of osteoporosis. PMID:22054967

  15. Chemical mediation of coral larval settlement by crustose coralline algae.

    PubMed

    Tebben, J; Motti, C A; Siboni, Nahshon; Tapiolas, D M; Negri, A P; Schupp, P J; Kitamura, Makoto; Hatta, Masayuki; Steinberg, P D; Harder, T

    2015-01-01

    The majority of marine invertebrates produce dispersive larvae which, in order to complete their life cycles, must attach and metamorphose into benthic forms. This process, collectively referred to as settlement, is often guided by habitat-specific cues. While the sources of such cues are well known, the links between their biological activity, chemical identity, presence and quantification in situ are largely missing. Previous work on coral larval settlement in vitro has shown widespread induction by crustose coralline algae (CCA) and in particular their associated bacteria. However, we found that bacterial biofilms on CCA did not initiate ecologically realistic settlement responses in larvae of 11 hard coral species from Australia, Guam, Singapore and Japan. We instead found that algal chemical cues induce identical behavioral responses of larvae as per live CCA. We identified two classes of CCA cell wall-associated compounds--glycoglycerolipids and polysaccharides--as the main constituents of settlement inducing fractions. These algae-derived fractions induce settlement and metamorphosis at equivalent concentrations as present in CCA, both in small scale laboratory assays and under flow-through conditions, suggesting their ability to act in an ecologically relevant fashion to steer larval settlement of corals. Both compound classes were readily detected in natural samples. PMID:26042834

  16. Marine algae and land plants share conserved phytochrome signaling systems

    DOE PAGESBeta

    Duanmu, Deqiang; Bachy, Charles; Sudek, Sebastian; Wong, Chee -Hong; Jimenez, Valeria; Rockwell, Nathan C.; Martin, Shelley S.; Ngan, Chew Yee; Reistetter, Emily N.; van Baren, Marijke J.; et al

    2014-09-29

    Phytochrome photosensors control a vast gene network in streptophyte plants, acting as master regulators of diverse growth and developmental processes throughout the life cycle. In contrast with their absence in known chlorophyte algal genomes and most sequenced prasinophyte algal genomes, a phytochrome is found in Micromonas pusilla, a widely distributed marine picoprasinophyte (<2 µm cell diameter). Together with phytochromes identified from other prasinophyte lineages, we establish that prasinophyte and streptophyte phytochromes share core light-input and signaling-output domain architectures except for the loss of C-terminal response regulator receiver domains in the streptophyte phytochrome lineage. Phylogenetic reconstructions robustly support the presence ofmore » phytochrome in the common progenitor of green algae and land plants. These analyses reveal a monophyletic clade containing streptophyte, prasinophyte, cryptophyte, and glaucophyte phytochromes implying an origin in the eukaryotic ancestor of the Archaeplastida. Transcriptomic measurements reveal diurnal regulation of phytochrome and bilin chromophore biosynthetic genes in Micromonas. The expression of these genes precedes both light-mediated phytochrome redistribution from the cytoplasm to the nucleus and increased expression of photosynthesis-associated genes. Prasinophyte phytochromes perceive wavelengths of light transmitted farther through seawater than the red/far-red light sensed by land plant phytochromes. Prasinophyte phytochromes also retain light-regulated histidine kinase activity lost in the streptophyte phytochrome lineage. Our studies demonstrate that light-mediated nuclear translocation of phytochrome predates the emergence of land plants and likely represents a widespread signaling mechanism in unicellular algae.« less

  17. MONITORING CHLOROPHYLL-A AS A MEASURE OF ALGAE IN LAKE TEXOMA MARINAS

    EPA Science Inventory

    Lake water quality in five marinas on Lake Texoma was determined over a two year period. Quality parameters were methyl tert-butyl ether, nitrate, some metals, fecal coliform and algae. Common blue-green algae can produce a toxin harmful to other aquatic organisms and humans. ...

  18. ALGAE-BACTERIA INTERACTION IN A LIGHT-DARK CYCLE (JOURNAL VERSION)

    EPA Science Inventory

    Nutrient and population dynamics accompanying algae-bacteria interaction were observed in unialgal, 18-liter batch cultures during a light-dark cycle. The green alga Chlorella vulgaris, and the nitrogen fixing blue-green Anabaena flos-aquae were inoculated with an aquatic communi...

  19. The current potential of algae biofuels in the United Arab Emirates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In spite of future uncertainties about industrial algae biofuel production, the UAE is planning to become "a world leader in biofuels from the algae industry by 2020;" thus joining major countries which have already started producing renewable energy and biofuels (biodiesel and bioethanol) from rene...

  20. Turf algae-mediated coral damage in coastal reefs of Belize, Central America.

    PubMed

    Wild, Christian; Jantzen, Carin; Kremb, Stephan Georg

    2014-01-01

    Many coral reefs in the Caribbean experienced substantial changes in their benthic community composition during the last decades. This often resulted in phase shifts from scleractinian coral dominance to that by other benthic invertebrate or algae. However, knowledge about how the related role of coral-algae contacts may negatively affect corals is scarce. Therefore, benthic community composition, abundance of algae grazers, and the abundance and character of coral-algae contacts were assessed in situ at 13 Belizean reef sites distributed along a distance gradient to the Belizean mainland (12-70 km): Mesoamerican Barrier Reef (inshore), Turneffe Atoll (inner and outer midshore), and Lighthouse Reef (offshore). In situ surveys revealed significantly higher benthic cover by scleractinian corals at the remote Lighthouse Reef (26-29%) when compared to the other sites (4-19%). The abundance of herbivorous fish and the sea urchin Diadema antillarum significantly increased towards the offshore reef sites, while the occurrence of direct coral-algae contacts consequently increased significantly with decreasing distance to shore. About 60% of these algae contacts were harmful (exhibiting coral tissue damage, pigmentation change, or overgrowth) for corals (mainly genera Orbicella and Agaricia), particularly when filamentous turf algae were involved. These findings provide support to the hypothesis that (turf) algae-mediated coral damage occurs in Belizean coastal, near-shore coral reefs. PMID:25276504

  1. Spatiotemporal associations of reservoir nutrient characteristics and the invasive, harmful alga Prymnesium parvum in West Texas

    USGS Publications Warehouse

    VanLandeghem, Matthew M.; Farooqi, Mukhtar; Southard, Greg M.; Patino, Reynaldo

    2015-01-01

    Golden alga (Prymnesium parvum) is a harmful alga that has caused ecological and economic harm in freshwater and marine systems worldwide. In inland systems of North America, toxic blooms have nearly eliminated fish populations in some systems. Modifying nutrient profiles through alterations to land or water use may be a viable alternative for golden alga control in reservoirs. The main objective of this study was to improve our understanding of the nutrient dynamics that influence golden alga bloom formation and toxicity in west Texas reservoirs. We examined eight sites in the Upper Colorado River basin, Texas: three impacted reservoirs that have experienced repeated golden alga blooms; two reference reservoirs where golden alga is present but nontoxic; and three confluence sites downstream of the impacted and reference sites. Total, inorganic, and organic nitrogen and phosphorus and their ratios were quantified monthly along with golden alga abundance and ichthyotoxicity between December 2010 and July 2011. Blooms persisted for several months at the impacted sites, which were characterized by high organic nitrogen and low inorganic nitrogen. At impacted sites, abundance was positively associated with inorganic phosphorus and bloom termination coincided with increases in inorganic nitrogen and decreases in inorganic phosphorus in late spring. Management of both inorganic and organic forms of nutrients may create conditions in reservoirs unfavorable to golden alga.

  2. Turf algae-mediated coral damage in coastal reefs of Belize, Central America

    PubMed Central

    Jantzen, Carin; Kremb, Stephan Georg

    2014-01-01

    Many coral reefs in the Caribbean experienced substantial changes in their benthic community composition during the last decades. This often resulted in phase shifts from scleractinian coral dominance to that by other benthic invertebrate or algae. However, knowledge about how the related role of coral-algae contacts may negatively affect corals is scarce. Therefore, benthic community composition, abundance of algae grazers, and the abundance and character of coral-algae contacts were assessed in situ at 13 Belizean reef sites distributed along a distance gradient to the Belizean mainland (12–70 km): Mesoamerican Barrier Reef (inshore), Turneffe Atoll (inner and outer midshore), and Lighthouse Reef (offshore). In situ surveys revealed significantly higher benthic cover by scleractinian corals at the remote Lighthouse Reef (26–29%) when compared to the other sites (4–19%). The abundance of herbivorous fish and the sea urchin Diadema antillarum significantly increased towards the offshore reef sites, while the occurrence of direct coral-algae contacts consequently increased significantly with decreasing distance to shore. About 60% of these algae contacts were harmful (exhibiting coral tissue damage, pigmentation change, or overgrowth) for corals (mainly genera Orbicella and Agaricia), particularly when filamentous turf algae were involved. These findings provide support to the hypothesis that (turf) algae-mediated coral damage occurs in Belizean coastal, near-shore coral reefs. PMID:25276504

  3. Artificial microfossils - Experimental studies of permineralization of blue-green algae in silica.

    NASA Technical Reports Server (NTRS)

    Oehler, J. H.; Schopf, J. W.

    1971-01-01

    A technique has been developed to artificially fossilize microscopic algae in crystalline silica under conditions of moderately elevated temperature and pressure. The technique is designed to simulate geochemical processes thought to have resulted in the preservation of organic microfossils in Precambrian bedded cherts. In degree of preservation and mineralogic setting, the artificially permineralized microorganisms are comparable to naturally occurring fossil algae.

  4. ALTERNATIVE WATER DISINFECTION SCHEMES FOR REDUCED TRIHALOMETHANE FORMATION. VOLUME 2. ALGAE AS PRECURSORS FOR TRIHALOMETHANES IN CHLORINATED DRINKING WATER

    EPA Science Inventory

    This study investigated three species of algae, Anabaena cylindrica, Scenedesmus quadricauda, and Pediastrum boryanum, with respect to their potential for the formation of THM when chlorinated. Algae were cultured and the cells (algal biomass) were separated from the extracellula...

  5. The future viability of algae-derived biodiesel under economic and technical uncertainties.

    PubMed

    Brownbridge, George; Azadi, Pooya; Smallbone, Andrew; Bhave, Amit; Taylor, Benjamin; Kraft, Markus

    2014-01-01

    This study presents a techno-economic assessment of algae-derived biodiesel under economic and technical uncertainties associated with the development of algal biorefineries. A global sensitivity analysis was performed using a High Dimensional Model Representation (HDMR) method. It was found that, considering reasonable ranges over which each parameter can vary, the sensitivity of the biodiesel production cost to the key input parameters decreases in the following order: algae oil content>algae annual productivity per unit area>plant production capacity>carbon price increase rate. It was also found that the Return on Investment (ROI) is highly sensitive to the algae oil content, and to a lesser extent to the algae annual productivity, crude oil price and price increase rate, plant production capacity, and carbon price increase rate. For a large scale plant (100,000 tonnes of biodiesel per year) the production cost of biodiesel is likely to be 0.8-1.6 per kg. PMID:24220544

  6. Red coralline algae assessed as marine pH proxies using 11B MAS NMR

    PubMed Central

    Cusack, M.; Kamenos, N. A.; Rollion-Bard, C.; Tricot, G.

    2015-01-01

    Reconstructing pH from biogenic carbonates using boron isotopic compositions relies on the assumption that only borate, and no boric acid, is present. Red coralline algae are frequently used in palaeoenvironmental reconstruction due to their widespread distribution and regular banding frequency. Prior to undertaking pH reconstructions using red coralline algae we tested the boron composition of the red coralline alga Lithothamnion glaciale using high field NMR. In bulk analysed samples, thirty percent of boron was present as boric acid. We suggest that prior to reconstructing pH using coralline algae 1) species-specific boron compositions and 2) within-skeleton special distributions of boron are determined for multiple species. This will enable site selective boron analyses to be conducted validating coralline algae as palaeo-pH proxies based on boron isotopic compositions. PMID:25640229

  7. Red coralline algae assessed as marine pH proxies using 11B MAS NMR.

    PubMed

    Cusack, M; Kamenos, N A; Rollion-Bard, C; Tricot, G

    2015-01-01

    Reconstructing pH from biogenic carbonates using boron isotopic compositions relies on the assumption that only borate, and no boric acid, is present. Red coralline algae are frequently used in palaeoenvironmental reconstruction due to their widespread distribution and regular banding frequency. Prior to undertaking pH reconstructions using red coralline algae we tested the boron composition of the red coralline alga Lithothamnion glaciale using high field NMR. In bulk analysed samples, thirty percent of boron was present as boric acid. We suggest that prior to reconstructing pH using coralline algae 1) species-specific boron compositions and 2) within-skeleton special distributions of boron are determined for multiple species. This will enable site selective boron analyses to be conducted validating coralline algae as palaeo-pH proxies based on boron isotopic compositions. PMID:25640229

  8. Red coralline algae assessed as marine pH proxies using 11B MAS NMR

    NASA Astrophysics Data System (ADS)

    Cusack, M.; Kamenos, N. A.; Rollion-Bard, C.; Tricot, G.

    2015-02-01

    Reconstructing pH from biogenic carbonates using boron isotopic compositions relies on the assumption that only borate, and no boric acid, is present. Red coralline algae are frequently used in palaeoenvironmental reconstruction due to their widespread distribution and regular banding frequency. Prior to undertaking pH reconstructions using red coralline algae we tested the boron composition of the red coralline alga Lithothamnion glaciale using high field NMR. In bulk analysed samples, thirty percent of boron was present as boric acid. We suggest that prior to reconstructing pH using coralline algae 1) species-specific boron compositions and 2) within-skeleton special distributions of boron are determined for multiple species. This will enable site selective boron analyses to be conducted validating coralline algae as palaeo-pH proxies based on boron isotopic compositions.

  9. Relative roles of endolithic algae and carbonate chemistry variability in the skeletal dissolution of crustose coralline algae

    NASA Astrophysics Data System (ADS)

    Reyes-Nivia, C.; Diaz-Pulido, G.; Dove, S.

    2014-09-01

    The susceptibility of crustose coralline algae (CCA) skeletons to dissolution is predicted to increase as oceans warm and acidify. Skeletal dissolution is caused by bioerosion from endolithic microorganisms and by chemical processes associated with undersaturation of carbonate minerals in seawater. Yet, the relative contribution of algal microborers and seawater carbonate chemistry to the dissolution of organisms that cement reefs under projected pCO2 and temperature (pCO2-T) scenarios have not been quantified. We exposed CCA skeletons (Porolithon onkodes) to four pCO2-T treatments (pre-industrial, present-day, SRES-B1 "reduced" pCO2, and SRES-A1FI "business-as-usual" pCO2 emission scenarios) under natural light cycles vs. constant dark conditions for 8 weeks. Dissolution rates of skeletons without photo-endoliths were dramatically higher (200%) than those colonized by endolithic algae across all pCO2-T scenarios. This suggests that daytime photosynthesis by microborers counteract dissolution by reduced saturation states resulting in lower net erosion rates over day-night cycles. Regardless of the presence or absence of phototrophic microborers, skeletal dissolution increased significantly under the spring A1FI "business-as-usual" scenario, confirming the CCA sensitivity to future oceans. Projected ocean acidity and temperature may significantly disturb the stability of reef frameworks cemented by CCA, but surficial substrates harbouring photosynthetic microborers will be less impacted than those without algal endoliths.

  10. Relative roles of endolithic algae and carbonate chemistry variability in the skeletal dissolution of crustose coralline algae

    NASA Astrophysics Data System (ADS)

    Reyes-Nivia, C.; Diaz-Pulido, G.; Dove, S.

    2014-02-01

    The susceptibility of crustose coralline algae (CCA) skeletons to dissolution is predicted to increase as oceans warm and acidify. Skeletal dissolution is caused by bioerosion from endolithic microorganisms and by chemical processes associated with undersaturation of carbonate minerals in seawater. Yet, the relative contribution of algal microborers and seawater carbonate chemistry to the dissolution of organisms that cement reefs under projected CO2 and temperature (CO2-T) scenarios have not been quantified. We exposed CCA skeletons (Porolithon onkodes) to four CO2-T treatments (pre-industrial, present-day, SRES-B1 reduced CO2 emission scenario, SRES-A1FI business-as-usual CO2 emission scenario) under natural light cycles vs. constant dark conditions for 8 weeks. Dissolution rates of skeletons without photo-endoliths were dramatically higher (200%) than those colonized by endolithic algae across all CO2-T scenarios. This suggests that daytime photosynthesis by microborers counteract dissolution by reduced saturation states resulting in lower net erosion rates over day-night cycles. Regardless of the presence or absence of phototrophic microborers, skeletal dissolution increased significantly under the spring A1FI "business-as-usual" scenario, confirming the CCA sensitivity to future oceans. Projected ocean acidity and temperature may significantly disturb the stability of reef frameworks cemented by CCA, but surficial substrates harboring photosynthetic microborers will be less impacted than those without algal endoliths.

  11. Separating ITCZ- and ENSO-related rainfall changes in the Galpagos over the last 3 kyr using D/H ratios of multiple lipid biomarkers

    NASA Astrophysics Data System (ADS)

    Atwood, Alyssa R.; Sachs, Julian P.

    2014-10-01

    We present a 3000-yr rainfall reconstruction from the Galpagos Islands that is based on paired biomarker records from the sediment of El Junco Lake. Located in the eastern equatorial Pacific, the climate of the Galpagos Islands is governed by movements of the Intertropical Convergence Zone (ITCZ) and the El Nio-Southern Oscillation (ENSO). We use a novel method for reconstructing past ENSO- and ITCZ-related rainfall changes through analysis of molecular and isotopic biomarker records representing several types of plants and algae that grow under differing climatic conditions. We propose that ?D values of dinosterol, a sterol produced by dinoflagellates, record changes in mean rainfall in El Junco Lake, while ?D values of C34 botryococcene, a hydrocarbon unique to the green alga Botryococcus braunii, record changes in rainfall associated with moderate-to-strong El Nio events. We use these proxies to infer changes in mean rainfall and El Nio-related rainfall over the past 3000 yr. During periods in which the inferred change in El Nio-related rainfall opposed the change in mean rainfall, we infer changes in the amount of ITCZ-related rainfall. Simulations with an idealized isotope hydrology model of El Junco Lake help illustrate the interpretation of these proxy reconstructions. Opposing changes in El Nio- and ITCZ-related rainfall appear to account for several of the largest inferred hydrologic changes in El Junco Lake. We propose that these reconstructions can be used to infer changes in frequency and/or intensity of El Nio events and changes in the position of the ITCZ in the eastern equatorial Pacific over the past 3000 yr. Comparison with El Junco Lake sediment grain size records indicates general agreement of inferred rainfall changes over the late Holocene.

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

    PubMed Central

    Samek, Ota; Jon, Alexandr; Pilt, Zden?k; Zemnek, Pavel; Nedbal, Ladislav; T?ska, Jan; Kotas, Petr; Trtlek, Martin

    2010-01-01

    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. PMID:22163676

  13. Managing phosphorus fertilizer to reduce algae, maintain water quality, and sustain yields in water-seeded rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In water-seeded rice systems blue-green algae (cyanobacteria) hinder early-season crop growth by dislodging rice seedlings and reducing light. Since algae are often phosphorus (P) limited, we investigated whether changing the timing of P fertilizer application could reduce algae without reducing cro...

  14. New cytotoxic oxygenated fucosterols from the brown alga Turbinaria conoides.

    PubMed

    Sheu, J H; Wang, G H; Sung, P J; Duh, C Y

    1999-02-01

    Fucosterol (1), 24xi-hydroperoxy-24-vinylcholesterol (2), 29-hydroperoxystigmasta-5,24(28)-dien-3beta-ol (3), 24-ethylcholesta-4,24(28)-dien-3-one (4), 24xi-hydroperoxy-24-ethylcholesta-4,28(29)-dien-3-one (5), 24-ethylcholesta-4,24(28)-dien-3,6-dione (6), 24xi-hydroperoxy-24-ethylcholesta-4,28(29)-dien-3,6-di one (7), 6beta-hydroxy-24-ethylcholesta-4,24(28)-dien-3-one (8), and 24xi-hydroperoxy-6beta-hydroxy-24-ethylcholesta-4,28(2 9)-dien-3-one (9) were isolated from the marine brown alga Turbinaria conoides. The structures of these compounds were established by spectral analysis. Isolated for the first time from a natural source, the oxygenated fucosterols 4-9 exhibit cytotoxicity against various cancer cell lines. PMID:10075746

  15. Genomic insights from the oleaginous model alga Nannochloropsis gaditana.

    PubMed

    Jinkerson, Robert E; Radakovits, Randor; Posewitz, Matthew C

    2013-01-01

    Nannochloropsis species have emerged as leading phototrophic microorganisms for the production of biofuels. Several isolates produce large quantities of triacylglycerols, grow rapidly, and can be cultivated at industrial scales. Recently, the mitochondrial, plastid and nuclear genomes of Nannochloropsis gaditana were sequenced. Genomic interrogation revealed several key features that likely facilitate the oleaginous phenotype observed in Nannochloropsis, including an over-representation of genes involved in lipid biosynthesis. Here we present additional analyses on gene orientation, vitamin B12 requiring enzymes, the acetyl-CoA metabolic node, and codon usage in N. gaditana. Nuclear genome transformation methods are established with exogenous DNA integration occurring via either random incorporation or by homologous recombination, making Nannochloropsis amenable to both forward and reverse genetic engineering. Completion of a draft genomic sequence, establishment of transformation techniques, and robust outdoor growth properties have positioned Nannochloropsis as a new model alga with significant potential for further development into an integrated photons-to-fuel production platform. PMID:22922732

  16. Antibiotics from Algae. XXXV. Phlorotannins from Ecklonia maxima1.

    PubMed

    Glombitza, K W; Vogels, H P

    1985-08-01

    New phloroglucinol derivatives were isolated from the ethanolic extract of ECKLONIA MAXIMA, a brown alga found off the west coast of South Africa. Most of these compounds contain dibenzo[1,4]dioxin elements. The common basic unit of all the compounds found is eckol, a hexahydroxyphenoxydibenzo[1,4]dioxin composed of 3 phloroglucinol units. Phloroeckol A and B represent four-ringed phloroglucinol derivatives, whereas the only five-ringed substance (furodehydroeckol) displays a furan structure in addition. Six-ringed phloroglucinol derivatives composed of two eckol units joined either symmetrically (such as 7,7'-bieckol, 9,9'-bieckol) or asymmetrically (7,9'-bieckol, dieckol) are found frequently. Apart from these, tetraphlorethol C, a four-ringed tetraphloroglucinol triether which lacks both dioxin and furan structures, also occurs. PMID:17340520

  17. Satellite-Observed Algae Blooms in China's Lake Taihu

    NASA Astrophysics Data System (ADS)

    Wang, Menghua; Shi, Wei

    2008-05-01

    During the spring of 2007, a massive blue-green algae (Microcystis) bloom broke out in Lake Taihu, one of the largest inland lakes in China. This freshwater lake is located in the Yangtze River delta (Figure 1), one of the world's most urbanized and heavily populated areas. The massive bloom event became an environmental crisis that prompted officials to cut tap water supply to several million residents in nearby Wuxi city in China's Jiangsu province. The outbreak, which the Chinese government identified as a major natural disaster, forced unprepared residents to rush to buy bottled water for their normal usage. This article presents results from an analysis of that event that demonstrate an application of satellite-derived imagery for inland lake water quality monitoring, assessment, and management.

  18. Alternate-Fueled Flight: Halophytes, Algae, Bio-, and Synthetic Fuels

    NASA Technical Reports Server (NTRS)

    Hendricks, R. C.

    2012-01-01

    Synthetic and biomass fueling are now considered to be near-term aviation alternate fueling. The major impediment is a secure sustainable supply of these fuels at reasonable cost. However, biomass fueling raises major concerns related to uses of common food crops and grasses (some also called "weeds") for processing into aviation fuels. These issues are addressed, and then halophytes and algae are shown to be better suited as sources of aerospace fuels and transportation fueling in general. Some of the history related to alternate fuels use is provided as a guideline for current and planned alternate fuels testing (ground and flight) with emphasis on biofuel blends. It is also noted that lessons learned from terrestrial fueling are applicable to space missions. These materials represent an update (to 2009) and additions to the Workshop on Alternate Fueling Sustainable Supply and Halophyte Summit at Twinsburg, Ohio, October 17 to 18, 2007.

  19. Alternate-Fueled Flight: Halophytes, Algae, Bio-, and Synthetic Fuels

    NASA Technical Reports Server (NTRS)

    Hendricks, R. C.

    2007-01-01

    Synthetic and biomass fueling are now considered to be near-term aviation alternate fueling. The major impediment is a secure sustainable supply of these fuels at reasonable cost. However, biomass fueling raises major concerns related to uses of common food crops and grasses (some also called "weeds") for processing into aviation fuels. These issues are addressed, and then halophytes and algae are shown to be better suited as sources of aerospace fuels and transportation fueling in general. Some of the history related to alternate fuels use is provided as a guideline for current and planned alternate fuels testing (ground and flight) with emphasis on biofuel blends. It is also noted that lessons learned from terrestrial fueling are applicable to space missions. These materials represent an update and additions to the Workshop on Alternate Fueling Sustainable Supply and Halophyte Summit at Twinsburg, OH, Oct. 17 to 18, 2007 (ref. 1).

  20. Testing an Algae-Based Air-Regeneration System

    NASA Technical Reports Server (NTRS)

    Nienow, James

    1998-01-01

    The potential of an air-regeneration system based on the growth of unicellular algae on the surface of porous ceramic tubes was evaluated. The system is fairly robust with respect to environmental conditions and is capable of maintaining algal cultures for up to 365 days. Under standard conditions (50-66 micro mol/sq mm s (PPF), 450 micro mol mol of CO2), mature tubes can remove CO2 at a rate of up to 90 micro mol/sq m min. Under these conditions, approximately 200 square meters of area would be required for each member of the crew. However, the rate of uptake increases with both photon flux and CO2 concentration in accordance with Michaelis-Menton dynamics. An extrapolation to conditions of saturating light and carbon dioxide indicates that the area required can be reduced by a factor of at least 2.5.

  1. Enhanced Genetic Tools for Engineering Multigene Traits into Green Algae

    PubMed Central

    Rasala, Beth A.; Chao, Syh-Shiuan; Pier, Matthew; Barrera, Daniel J.; Mayfield, Stephen P.

    2014-01-01

    Transgenic microalgae have the potential to impact many diverse biotechnological industries including energy, human and animal nutrition, pharmaceuticals, health and beauty, and specialty chemicals. However, major obstacles to sophisticated genetic and metabolic engineering in algae have been the lack of well-characterized transformation vectors to direct engineered gene products to specific subcellular locations, and the inability to robustly express multiple nuclear-encoded transgenes within a single cell. Here we validate a set of genetic tools that enable protein targeting to distinct subcellular locations, and present two complementary methods for multigene engineering in the eukaryotic green microalga Chlamydomonas reinhardtii. The tools described here will enable advanced metabolic and genetic engineering to promote microalgae biotechnology and product commercialization. PMID:24710110

  2. Convergence of joint mechanics in independently evolving, articulated coralline algae.

    PubMed

    Janot, Kyra; Martone, Patrick T

    2016-02-01

    Flexible joints are a key innovation in the evolution of upright coralline algae. These structures have evolved in parallel at least three separate times, allowing the otherwise rigid, calcified thalli of upright corallines to achieve flexibility when subjected to hydrodynamic stress. As all bending occurs at the joints, stress is amplified, which necessitates that joints be made of material that is both extensible and strong. Data presented here indicate that coralline joints are in fact often stronger and more extensible, as well as tougher, than fleshy seaweed tissues. Corallinoids are particularly strong and tough, which is largely due to the presence of secondary cell walls that strengthen the joint tissue without adding bulk to the joint itself. Cell wall thickness is shown to be a large contributing factor to strength across all groups, with the exception of the corallinoid Cheilosporum sagittatum, which likely possesses distinct chemical composition in its walls to increase strength beyond that of all other species tested. PMID:26596529

  3. Toxicity testing with the marine algae, Symbiodinium kawagutii (Dinophyceae)

    SciTech Connect

    Gorrie, J.R.; Bidwell, J.R.; Rippingale, R.J.

    1994-12-31

    The dinoflagellate, Symbiodinium kawagutii, is among the algal taxa which exist in symbiosis with a range of marine invertebrates. S. kawagutii is commonly found in association with the Hawaiian stony coral, Montipora verrucosa. The algae has been successfully cultured in the laboratory using a common marine algal growth media (Guillard f/2), and sufficient cell densities were achieved in a 96-hr bioassay to allow statistical evaluation of toxicity data. A 96-hr EC{sub 50} of 6.47 mg/L (95% C.I.: 3.54--9.88 mg/L) was calculated after exposure to potassium dichromate. Wide distribution of the coral host and ecological importance of the symbiosis make S. kawagutii an excellent candidate species for hazard evaluation in tropical marine ecosystems. Continuing research will seek to further refine the bioassay, including the use of a microplate technique for more rapid testing.

  4. Regulation of Chlorophyll Synthesis in the Green Alga Golenkinia

    PubMed Central

    Ellis, Richard; Spooner, Ted; Yakulis, Robert

    1975-01-01

    Chlorophyll synthesis in Golenkinia is inhibited 10-fold by growth in darkness on acetate or by growth on elevated concentrations of acetate in the light, particularly if the growth medium contains low levels of nitrogen. Glucose has no such inhibitory effect. ?-Aminolevulinic acid, with a maximal effect at 0.01 m, but not its precursors, overrides the inhibitory effect of acetate and darkness, restoring chlorophyll synthesis. Glycine, succinate, and ?-ketoglutarate, the precursors tested, all enter the cell. Cells forming chlorophyll produce significantly more aminolevulinic acid than do cells becoming bleached, further indicating the important regulatory role of this compound. Cyclic AMP has no effect on chlorophyll synthesis. These results are compared with those obtained studying other algae, and a mechanism relating light and acetate to chlorophyll formation is proposed. PMID:16659169

  5. In vitro identification of rhodopsin in the green alga Chlamydomonas.

    PubMed

    Beckmann, M; Hegemann, P

    1991-04-16

    The unicellular alga Chlamydomonas can detect both intensity and direction of the ambient light and adjust its swimming speed and direction accordingly. On the basis of physiological experiments, the functional photoreceptor for this visual process has recently shown to be a rhodopsin. We here report the in vitro identification of endogenous retinal and a rhodopsin in Chlamydomonas cell extracts and purified membrane preparations. The rhodopsin absorption spectrum has fine structure with the maximum at 495 nm and matches the action spectra for the behavioral light responses. The rhodopsin can be bleached and subsequently reconstituted with exogenous retinal. Labeling with [3H]retinal occurs in the final preparation only with a single protein with a molecular weight of 32,000. We conclude that this protein is the visual photoreceptor in Chlamydomonas. PMID:2015225

  6. The effect of low temperature on Antarctic endolithic green algae

    NASA Technical Reports Server (NTRS)

    Meyer, M. A.; Morris, G. J.; Friedmann, E. I.

    1988-01-01

    Laboratory experiments show that undercooling to about -5 degrees C occurs in colonized Beacon sandstones of the Ross Desert, Antarctica. High-frequency temperature oscillations between 5 degrees C and -5 degrees C or -10 degrees C (which occur in nature on the rock surface) did not damage Hemichloris antarctica. In a cryomicroscope, H. antarctica appeared to be undamaged after slow or rapid cooling to -50 degrees C. 14CO2 incorporation after freezing to -20 degrees C was unaffected in H. antarctica or in Trebouxia sp. but slightly depressed in Stichococcus sp. (isolated from a less extreme Antarctic habitat). These results suggest that the freezing regime in the Antarctic desert is not injurious to endolithic algae. It is likely that the freezing-point depression inside the rock makes available liquid water for metabolic activity at subzero temperatures. Freezing may occur more frequently on the rock surface and contribute to the abiotic nature of the surface.

  7. Enhanced genetic tools for engineering multigene traits into green algae.

    PubMed

    Rasala, Beth A; Chao, Syh-Shiuan; Pier, Matthew; Barrera, Daniel J; Mayfield, Stephen P

    2014-01-01

    Transgenic microalgae have the potential to impact many diverse biotechnological industries including energy, human and animal nutrition, pharmaceuticals, health and beauty, and specialty chemicals. However, major obstacles to sophisticated genetic and metabolic engineering in algae have been the lack of well-characterized transformation vectors to direct engineered gene products to specific subcellular locations, and the inability to robustly express multiple nuclear-encoded transgenes within a single cell. Here we validate a set of genetic tools that enable protein targeting to distinct subcellular locations, and present two complementary methods for multigene engineering in the eukaryotic green microalga Chlamydomonas reinhardtii. The tools described here will enable advanced metabolic and genetic engineering to promote microalgae biotechnology and product commercialization. PMID:24710110

  8. A new ketosteroid from red alga Acanthophora spicifera

    NASA Astrophysics Data System (ADS)

    Shi, Dayong; Guo, Shuju; Fan, Xiao

    2011-05-01

    A new ketosteroid, along with six known steroids, was isolated from the ethanolic extracts of red alga Acanthophora spicifera (Vahl.) Boergesen. The structures, identified using chemical and spectroscopic methods including 2D NMR, were: (1) 22-hydroxy-5α-cholest-3,6-dione, (2) 6-hydroxycholest-4-ene-3-one, (3) cholest-4-ene-3,6-dione, (4) cholest-5-ene-3β-ol, (5) 5α-cholestane-3,6-dione, (6) β-Sitosterol and (7) Saringosterol. The MTT method was used to test the cytotoxicity of the compounds against the human cancer cell lines, HCT-8, Bel-7402, BGC-823, A549 and HELA. Compounds 1, 2, 3 and 5 showed moderate cytotoxic activity against human cancer cell lines.

  9. Bioactive Chemical Constituents from the Brown Alga Homoeostrichus formosana

    PubMed Central

    Fang, Hui-Yu; Chokkalingam, Uvarani; Chiou, Shu-Fen; Hwang, Tsong-Long; Chen, Shu-Li; Wang, Wei-Lung; Sheu, Jyh-Horng

    2014-01-01

    A new chromene derivative, 2-(4',8'-dimethylnona-3'E,7'-dienyl)-8-hydroxy-2,6-dimethyl-2H-chromene (1) together with four known natural products, methylfarnesylquinone (2), isololiolide (3), pheophytin a (4), and ?-carotene (5) were isolated from the brown alga Homoeostrichus formosana. The structure of 1 was determined by extensive 1D and 2D spectroscopic analyses. Acetylation of 1 yielded the monoacetylated derivative 2-(4',8'-dimethylnona-3'E,7'-dienyl)-8-acetyl-2,6-dimethyl-2H-chromene (6). Compounds 16 exhibited various levels of cytotoxic, antibacterial, and anti-inflammatory activities. Compound 2 was found to display potent in vitro anti-inflammatory activity by inhibiting the generation of superoxide anion (IC50 0.22 0.03 ?g/mL) and elastase release (IC50 0.48 0.11 ?g/mL) in FMLP/CB-induced human neutrophils. PMID:25561228

  10. Simultaneous coupling of phototaxis and electrotaxis in Volvox algae

    NASA Astrophysics Data System (ADS)

    Hayashi, Yoshikatsu; Sugawara, Ken

    2014-04-01

    In nature, living creatures are affected by several stimuli simultaneously. The response of living creatures to stimuli is called taxis. In order to reveal the principles of taxis behavior in response to complex stimuli, we simultaneously applied photostimulation and electric stimulation perpendicularly to a Volvox algae solution. The probability distribution of the swimming direction showed that a large population of swimming cells moved in a direction that was the result of the composition of phototaxis and electrotaxis. More surprisingly, we uncovered the coupling of signs of taxis, i.e., coupling of phototaxis and electrotaxis induced positive electrotaxis, which did not emerge in the single stimulation experiments. We qualitatively explained the coupling of taxis based on the polarization of the swimming cells induced by the simultaneous photo- and electric stimulation.

  11. Genomic insights from the oleaginous model alga Nannochloropsis gaditana

    PubMed Central

    Jinkerson, Robert E.; Radakovits, Randor; Posewitz, Matthew C.

    2013-01-01

    Nannochloropsis species have emerged as leading phototrophic microorganisms for the production of biofuels. Several isolates produce large quantities of triacylglycerols, grow rapidly, and can be cultivated at industrial scales. Recently, the mitochondrial, plastid and nuclear genomes of Nannochloropsis gaditana were sequenced. Genomic interrogation revealed several key features that likely facilitate the oleaginous phenotype observed in Nannochloropsis, including an over-representation of genes involved in lipid biosynthesis. Here we present additional analyses on gene orientation, vitamin B12 requiring enzymes, the acetyl-CoA metabolic node, and codon usage in N. gaditana. Nuclear genome transformation methods are established with exogenous DNA integration occurring via either random incorporation or by homologous recombination, making Nannochloropsis amenable to both forward and reverse genetic engineering. Completion of a draft genomic sequence, establishment of transformation techniques, and robust outdoor growth properties have positioned Nannochloropsis as a new model alga with significant potential for further development into an integrated photons-to-fuel production platform. PMID:22922732

  12. Degradation of petroleum by an alga, Prototheca zopfii.

    PubMed

    Walker, J D; Colwell, R R; Petrakis, L

    1975-07-01

    Prototheca zopfii is an achlorophyllous alga which degrades oil. It has been found to degrade 10 and 40% of a motor oil and crude oil, respectively, when tested under appropriate conditions. Degradation of the crude oil observed in this study compares well with the amount of degradation accomplished by bacteria. P. zopfii was found to degrade a greater percentage of the aromatic hydrocarbons in motor oil than of the saturated hydrocarbons and a greater percentage of saturated hydrocarbons in crude oil than of aromatic hydrocarbons. Resins and asphaltens were produced during degradation of motor oil, whereas these fractions in crude oil were degraded. P. zopfii did not demonstrate preferential utilization of lower homologues of cycloalkanes and aromatics as has been observed with bacteria. PMID:1147621

  13. Degradation of Petroleum by an Alga, Prototheca Zopfii

    PubMed Central

    Walker, J. D.; Colwell, R. R.; Petrakis, L.

    1975-01-01

    Prototheca zopfii is an achlorophyllous alga which degrades oil. It has been found to degrade 10 and 40% of a motor oil and crude oil, respectively, when tested under appropriate conditions. Degradation of the crude oil observed in this study compares well with the amount of degradation accomplished by bacteria. P. zopfii was found to degrade a greater percentage of the aromatic hydrocarbons in motor oil than of the saturated hydrocarbons and a greater percentage of saturated hydrocarbons in crude oil than of aromatic hydrocarbons. Resins and asphaltenes were produced during degradation of motor oil, whereas these fractions in crude oil were degraded. P. zopfii did not demonstrate preferential utilization of lower homologues of cycloalkanes and aromatics as has been observed with bacteria. PMID:1147621

  14. Tyrosinase inhibitors isolated from the edible brown alga Ecklonia stolonifera.

    PubMed

    Kang, Hye Sook; Kim, Hyung Rak; Byun, Dae Seok; Son, Byeng Wha; Nam, Taek Jeong; Choi, Jae Sue

    2004-12-01

    Extracts from seventeen seaweeds were determined for tyrosinase inhibitory activity using mushroom tyrosinase with L-tyrosine as a substrate. Only one of them, Ecklonia stolonifera OKAMURA (Laminariaceae) belonging to brown algae, showed high tyrosinase inhibitory activity. Bioassay-guided fractionation of the active ethyl acetate (EtOAc) soluble fraction from the methanolic extract of E. stolonifera, led us to the isolation of phloroglucinol derivatives [phloroglucinol (1), eckstolonol (2), eckol (3), phlorofucofuroeckol A (4), and dieckol (5)]. Compounds 1 approximately 5 were found to inhibit the oxidation of L-tyrosine catalyzed by mushroom tyrosinase with IC50 values of 92.8, 126, 33.2, 177, and 2.16 microg/mL, respectively. It was compared with those of kojic acid and arbutin, well-known tyrosinase inhibitors, with IC50 values of 6.32 and 112 microg/ mL, respectively. The inhibitory kinetics analyzed from Lineweaver-Burk plots, showed compounds 1 and 2 to be competitive inhibitors with Ki of 2.3x10(-4) and 3.1x10(-4) M, and compounds 3 approximately 5 to be noncompetitive inhibitors with Ki of 1.9x10(-5), 1.4x10(-3) and 1.5x10(-5) M, respectively. This work showed that phloroglucinol derivatives, natural compounds found in brown algae, could be involved in the control of pigmentation in plants and other organisms through inhibition of tyrosinase activity using L-tyrosine as a substrate. PMID:15646796

  15. Developing a Forward Model of Encrusting Coralline Algae

    NASA Astrophysics Data System (ADS)

    Ng, J.; Williams, B.; Thompson, D. M.; Halfar, J.

    2014-12-01

    Climate proxy data has traditionally been interpreted through inverse models, which extract physical climate variables from proxy variables. This approach assumes stationarity of the proxy-climate relationship, typically reduces climate signal to a single variable, and requires extensive observational records. In contrast, forward models reverse the relationship, simulating proxy variables from physical climate variables for comparison to observed proxy variables. Since this approach accounts for multiple climate variables and avoids stationarity issues, forward models have been developed for several climate proxies, including tree ring width and oxygen stable isotopes (?18O) of corals. Here we develop a basic forward model for the climate archive coralline alga Clathromorphum sp.This long-lived alga grows in mid-to-high latitude regions and forms a solid calcite skeleton with annual growth bands similar to those of trees and tropical corals. Sub-annually resolved ?18O in annual growth bands (?18Ospec) provide a record of local environmental and climatic factors, notably sea surface temperature (SST) and sea water oxygen stable isotopes (?18Osw). We model Clathromorphum ?18Ospec in the Aleutian islands from gridded SST and ?18Osw of the growing season from 1960 to 2004. The strongest climate signal is observed in July, likely due to suppressed growth in other months. Initial results suggest no influence of growth rate on the fractionation of oxygen isotopes and indicate that ?18Ospec anomalies are significantly correlated with summer SST anomalies. We run this forward model with observed SST and ?18Osw and compare the resulting simulated ?18Ospec with that measured in live-collected specimens. This foundational model may be adapted to other regions and modified to include other variables influencing coralline isotope records, such as light availability and ice coverage.

  16. Effect of Alexandrium tamarense on three bloom-forming algae

    NASA Astrophysics Data System (ADS)

    Yin, Juan; Xie, Jin; Yang, Weidong; Li, Hongye; Liu, Jiesheng

    2010-07-01

    We investigated the allelopathic properties of Alexandrium tamarense (Laboar) Balech on the growth of Prorocentrum donghaiense Lu, Chattonella marina (Subrahmanyan) Hara et Chihara and Heterosigma akashiwo (Hada) Hada in a laboratory experiment. We examined the growth of A. tamarense, C. marina, P. donghaiense and H. Akashiwo in co-cultures and the effect of filtrates from A. tamarense cultures in various growth phases, on the three harmful algal bloom (HAB)-forming algae. In co-cultures with A. tamarense, both C. marina and H. akashiwo were dramatically suppressed at high cell densities; in contrast, the growth of P. donghaiense varied in different inoculative ratios of A. tamarense and P. donghaiense. When the ratio was 1:1 ( P. donghaiense: A. tamarense), growth of P. donghaiense was inhibited considerably, while the growth of P. donghaiense was almost the same as that of the control when the ratio was 9:1. The growth difference of P. donghaiense, C. marina and H. akashiwo when co-cultured with A. tamarense indicated that the allelopathic effect may be one of the important factors in algal competition and phytoplankton succession involving A. tamarense. In addition, the filtrate from A. tamarense culture had negative impacts on these three HAB algae, and such inhibition varied with different growth phases of A. tamarense in parallel with reported values of PSP toxin content in Alexandrium cells. This implied that PSP toxin was possibly involved in allelopathy of A. tamarense. However, the rapid decomposition and inactivation of PSP toxin above pH 7 weakened this possibility. Further studies on the allelochemicals responsible for the allelopathy of A. tamarense need to be carried out in future.

  17. Ecotoxicological effects of Mikado and Viper on algae and daphnids.

    PubMed

    Marques, C R; Gonalves, A M M; Pereira, R; Gonalves, F

    2012-12-01

    The toxicity of single and combined formulated herbicides (Mikado and Viper) was assessed on several endpoints in species from two trophic levels: algae growth-Pseudokirchneriella subcapitata and Chlorella vulgaris-immobilization and life-history traits (only for single compound toxicity) of daphnids-Daphnia longispina and Daphnia magna. Viper was the most toxic formulated herbicide. It was hypothesized that the toxicity of both formulated herbicides could have been enhanced by adjuvants, especially for Viper. In most cases, the sublethal endpoints were the most sensitive and affected by both formulations, comparatively to their acute effects. Concentration addition (CA) and independent action (IA) models provided an accurate description of Mikado and Viper joint action on algae growth and immobilization of daphnids, although significant deviations were always detected. A low-dose antagonism and high-dose synergism were identified for P. subcapitata, whereas C. vulgaris response deviated antagonistically from CA and synergistically from IA. For both daphnids, however, synergistic effects were observed for higher mixture concentrations. Under a regulatory standpoint, CA provided the most conservative estimation either because the mixture effects were overestimated or less subestimated than IA. Overall, the great sensitivity differences observed within species did not allow the conclusion that one trophic level was more tolerant than the other. Instead, P. subcapitata was always the most sensitive species to both herbicide formulations, followed by D. longispina, while D. magna and C. vulgaris were the most tolerant species. On a whole, further studies are needed toward a comprehensive understanding of herbicides mode of action, their effects at lower biological-level endpoints, and under different mixture designs. PMID:21374788

  18. [The effect of chromium removal by algae-bacteria Bostrychia calliptera (Rhodomelaceae) consortia under laboratory conditions].

    PubMed

    Rengifo-Gallego, Ana Luca; Pea-Salamanca, Enrique; Benitez-Campo, Neyla

    2012-09-01

    Water pollution is one of the most important environmental problems worldwide. Recently, biotechnology studies have oriented efforts to study algae-bacterium consortia with the aim to understand the mechanisms to find a possible solution in environmental sciences. This study determined the percentage of chromium removal by the alga-bacterium association exposed to a set of different chromium concentrations under controlled in vitro conditions. Wild plants of Bostrychia calliptera associated with bacterial populations were collected from Dagua River, Pacific coast of Colombia, and were monitored in the laboratory. The trial was conducted with synthetic seawater in bioreactors at two chromium levels: 5 and 10mg/L, and four different experimental treatments: i) algae-bacteria (AB), ii) algae with antibiotic (AA), iii) algal surface sediment, Natural Bacterial Consortium (CBN), and iv) the control without algae or bacteria. The experimental design followed a model of two factors (chromium concentration x combination types) with repeated measures using one factor. The microbial population behavior and the chromium concentration percentage were monitored by using atomic absorption spectroscopy (AAS). According to the data, Algae-bacteria (AB) treatment was the most efficient combination at 10mg/L (87%), whereas the bacterial consortia (CBN) was the most efficient at 5mg/L (62.85%). The results showed significant differences of chromium uptake between algae-bacteria (AB) and natural bacterial consortia (CBN), meaning the importance of those treatments in the chromium removal from coastal waters. PMID:23025079

  19. Combining micro-structures and micro-algae to increase lipid production for bio-fuel

    NASA Astrophysics Data System (ADS)

    Vyawahare, Saurabh; Zhu, Emilly; Mestler, Troy; Estévez-Torres, André.; Austin, Robert

    2011-03-01

    3rd generation bio-fuels like lipid producing micro-algae are a promising source of energy that could replace our dependence on petroleum. However, until there are improvements in algae oil yields, and a reduction in the energy needed for processing, algae bio-fuels are not economically competitive with petroleum. Here, we describe our work combining micro-fabricated devices with micro-algae Neochloris oleoabundans, a species first isolated on the sand dunes of Saudi Arabia. Inserting micro-algae of varying fitness into a landscape of micro-habitats allows us to evolve and select them based on a variety of conditions like specific gravity, starvation response and Nile Red fluorescence (which is a marker for lipid production). Hence, we can both estimate the production of lipids and generate conditions that allow the creation and isolation of algae which produce higher amounts of lipids, while discarding the rest. Finally, we can use micro-fabricated structures and flocculation to de-water these high lipid producing algae, reducing the need for expensive centrifugation and filtration.

  20. Environmental impacts of algae-derived biodiesel and bioelectricity for transportation.

    PubMed

    Clarens, Andres F; Nassau, Hagai; Resurreccion, Eleazer P; White, Mark A; Colosi, Lisa M

    2011-09-01

    Algae are a widely touted source of bioenergy with high yields, appreciable lipid contents, and an ability to be cultivated on marginal land without directly competing with food crops. Nevertheless, recent work has suggested that large-scale deployment of algae bioenergy systems could have unexpectedly high environmental burdens. In this study, a "well-to-wheel" life cycle assessment was undertaken to evaluate algae's potential use as a transportation energy source for passenger vehicles. Four algae conversion pathways resulting in combinations of bioelectricity and biodiesel were assessed for several relevant nutrient procurement scenarios. Results suggest that algae-to-energy systems can be either net energy positive or negative depending on the specific combination of cultivation and conversion processes used. Conversion pathways involving direct combustion for bioelectricity production generally outperformed systems involving anaerobic digestion and biodiesel production, and they were found to generate four and fifteen times as many vehicle kilometers traveled (VKT) per hectare as switchgrass or canola, respectively. Despite this, algae systems exhibited mixed performance for environmental impacts (energy use, water use, and greenhouse gas emissions) on a "per km" basis relative to the benchmark crops. This suggests that both cultivation and conversion processes must be carefully considered to ensure the environmental viability of algae-to-energy processes. PMID:21774477

  1. Algae in Fish Feed: Performances and Fatty Acid Metabolism in Juvenile Atlantic Salmon

    PubMed Central

    Norambuena, Fernando; Hermon, Karen; Skrzypczyk, Vanessa; Emery, James A.; Sharon, Yoni; Beard, Alastair; Turchini, Giovanni M.

    2015-01-01

    Algae are at the base of the aquatic food chain, producing the food resources that fish are adapted to consume. Previous studies have proven that the inclusion of small amounts (<10% of the diet) of algae in fish feed (aquafeed) resulted in positive effects in growth performance and feed utilisation efficiency. Marine algae have also been shown to possess functional activities, helping in the mediation of lipid metabolism, and therefore are increasingly studied in human and animal nutrition. The aim of this study was to assess the potentials of two commercially available algae derived products (dry algae meal), Verdemin (derived from Ulva ohnoi) and Rosamin (derived from diatom Entomoneis spp.) for their possible inclusion into diet of Atlantic Salmon (Salmo salar). Fish performances, feed efficiency, lipid metabolism and final product quality were assessed to investigated the potential of the two algae products (in isolation at two inclusion levels, 2.5% and 5%, or in combination), in experimental diets specifically formulated with low fish meal and fish oil content. The results indicate that inclusion of algae product Verdemin and Rosamin at level of 2.5 and 5.0% did not cause any major positive, nor negative, effect in Atlantic Salmon growth and feed efficiency. An increase in the omega-3 long-chain polyunsaturated fatty acid (n-3 LC-PUFA) content in whole body of fish fed 5% Rosamin was observed. PMID:25875839

  2. Phycobilisome Mobility and Its Role in the Regulation of Light Harvesting in Red Algae1[W

    PubMed Central

    Kaňa, Radek; Kotabová, Eva; Lukeš, Martin; Papáček, Štěpán; Matonoha, Ctirad; Liu, Lu-Ning; Prášil, Ondřej; Mullineaux, Conrad W.

    2014-01-01

    Red algae represent an evolutionarily important group that gave rise to the whole red clade of photosynthetic organisms. They contain a unique combination of light-harvesting systems represented by a membrane-bound antenna and by phycobilisomes situated on thylakoid membrane surfaces. So far, very little has been revealed about the mobility of their phycobilisomes and the regulation of their light-harvesting system in general. Therefore, we carried out a detailed analysis of phycobilisome dynamics in several red alga strains and compared these results with the presence (or absence) of photoprotective mechanisms. Our data conclusively prove phycobilisome mobility in two model mesophilic red alga strains, Porphyridium cruentum and Rhodella violacea. In contrast, there was almost no phycobilisome mobility in the thermophilic red alga Cyanidium caldarium that was not caused by a decrease in lipid desaturation in this extremophile. Experimental data attributed this immobility to the strong phycobilisome-photosystem interaction that highly restricted phycobilisome movement. Variations in phycobilisome mobility reflect the different ways in which light-harvesting antennae can be regulated in mesophilic and thermophilic red algae. Fluorescence changes attributed in cyanobacteria to state transitions were observed only in mesophilic P. cruentum with mobile phycobilisomes, and they were absent in the extremophilic C. caldarium with immobile phycobilisomes. We suggest that state transitions have an important regulatory function in mesophilic red algae; however, in thermophilic red algae, this process is replaced by nonphotochemical quenching. PMID:24948833

  3. Can benthic algae mediate larval behavior and settlement of the coral Acropora muricata?

    NASA Astrophysics Data System (ADS)

    Denis, V.; Loubeyres, M.; Doo, S. S.; de Palmas, S.; Keshavmurthy, S.; Hsieh, H. J.; Chen, C. A.

    2014-06-01

    The resilience of coral reefs relies significantly on the ability of corals to recover successfully in algal-dominated environments. Larval settlement is a critical but highly vulnerable stage in the early life history of corals. In this study, we analyzed how the presence of two upright fleshy algae, Sargassum mcclurei (SM) and Padina australis (PA), and one crustose coralline algae, Mesophyllum simulans (MS), affects the settlement of Acropora muricata larvae. Coral larvae were exposed to seawater flowing over these algae at two concentrations. Larval settlement and mortality were assessed daily through four variables related to their behavior: swimming, substratum testing, metamorphosis, and stresses. Temperature, dissolved oxygen, pH, algal growth, and photosynthetic efficiency were monitored throughout the experiment. Results showed that A. muricata larvae can settle successfully in the absence of external stimuli (63 6 % of the larvae settled in control treatments). While algae such as MS may stimulate substrate testing and settlement of larvae in the first day after competency, they ultimately had a lower settlement rate than controls. Fleshy algae such as PA, and in a lesser measure SM, induced more metamorphosis than controls and seemed to eventually stimulate settlement. A diverse combination of signals and/or modifications of microenvironments by algae and their associated microbial communities may explain the pattern observed in coral settlement. Overall, this study contributes significantly to the knowledge of the interaction between coral and algae, which is critical for the resilience of the reefs.

  4. Isolation and properties of fungi that lyse blue-green algae.

    PubMed Central

    Redhead, K; Wright, S J

    1978-01-01

    Of 70 pure microbial cultures isolated from aquatic habitats, soil, and air according to the ability to lyse live blue-green algae, 62 were fungi representing the genera Acremonium, Emericellopsis, and Verticillium. Algal-lysing fungi were isolated from all habitat types sampled. The remaining isolates comprised four bacteria and four streptomycetes. All isolates lysed Anabaena flos-aquae and, in most cases, several other filamentous and unicellular blue-green algae. The fungi generally showed greater activity than most other isolates towards a wider range of susceptible algae, including green algae in some cases. Acremonium and Emericellopsis isolates, but not Verticillium, also inhibited the growth of blue-green algae and gram-positive bacteria, but did not lyse the latter. Lysis of blue green algae by Acremonium and Emericellopsis spp. was associated with the formation of diffusible heat-stable extracellular factors which, evidence suggests, could be cephalosporin antibiotic(s). Blue-green algae were also lysed by pure cephalosporin C. The frequent isolation of lytic fungi from algal habitats suggests a possible natural algal-destroying role for such fungi, which might be exploitable for algal bloom control. Images PMID:418740

  5. Landfill leachate--a water and nutrient resource for algae-based biofuels.

    PubMed

    Edmundson, Scott J; Wilkie, Ann C

    2013-01-01

    There is a pressing need for sustainable renewable fuels that do not negatively impact food and water resources. Algae have great potential for the production of renewable biofuels but require significant water and fertilizer resources for large-scale production. Municipal solid waste (MSW) landfill leachate (LL) was evaluated as a cultivation medium to reduce both water and elemental fertilizer demands of algae cultivation. Daily growth rate and cell yield of two isolated species of algae (Scenedesmus cf. rubescens and Chlorella cf. ellipsoidea) were cultivated in MSW LL and compared with Bold's Basal Medium (BBM). Results suggest that LL can be used as a nutrient resource and medium for the cultivation of algae biomass. S. cf. rubescens grew well in 100% LL, when pH was regulated, with a mean growth rate and cell yield 91.2% and 92.8% of those observed in BBM, respectively. S. cf. rubescens was more adaptable than C. cf. ellipsoidea to the LL tested. The LL used in this study supported a maximum volumetric productivity of 0.55 g/L/day of S. cf. rubescens biomass. The leachate had sufficient nitrogen to supply 17.8 g/L of algae biomass, but was limited by total phosphorus. Cultivation of algae on LL offsets both water and fertilizer consumption, reducing the environmental footprint and increasing the potential sustainability of algae-based biofuels. PMID:24350438

  6. Feeding Preferences and the Nutritional Value of Tropical Algae for the Abalone Haliotis asinina

    PubMed Central

    Angell, Alex R.; Pirozzi, Igor; de Nys, Rocky; Paul, Nicholas A.

    2012-01-01

    Understanding the feeding preferences of abalone (high-value marine herbivores) is integral to new species development in aquaculture because of the expected link between preference and performance. Performance relates directly to the nutritional value of algae or any feedstock which in turn is driven by the amino acid content and profile, and specifically the content of the limiting essential amino acids. However, the relationship between feeding preferences, consumption and amino acid content of algae have rarely been simultaneously investigated for abalone, and never for the emerging target species Haliotis asinina. Here we found that the tropical H. asinina had strong and consistent preferences for the red alga Hypnea pannosa and the green alga Ulva flexuosa, but no overarching relationship between protein content (sum of amino acids) and preference existed. For example, preferred Hypnea and Ulva had distinctly different protein contents (12.64 vs. 2.99 g 100 g?1) and the protein-rich Asparagopsis taxiformis (>15 g 100 g?1 of dry weight) was one of the least preferred algae. The limiting amino acid in all algae was methionine, followed by histidine or lysine. Furthermore we demonstrated that preferences can largely be removed using carrageenan as a binder for dried alga, most likely acting as a feeding attractant or stimulant. The apparent decoupling between feeding preference and algal nutritive values may be due to a trade off between nutritive values and grazing deterrence associated with physical and chemical properties. PMID:22719967

  7. Phycobilisome Mobility and Its Role in the Regulation of Light Harvesting in Red Algae.

    PubMed

    Kaňa, Radek; Kotabová, Eva; Lukeš, Martin; Papáček, Stěpán; Matonoha, Ctirad; Liu, Lu-Ning; Prášil, Ondřej; Mullineaux, Conrad W

    2014-06-19

    Red algae represent an evolutionarily important group that gave rise to the whole red clade of photosynthetic organisms. They contain a unique combination of light-harvesting systems represented by a membrane-bound antenna and by phycobilisomes situated on thylakoid membrane surfaces. So far, very little has been revealed about the mobility of their phycobilisomes and the regulation of their light-harvesting system in general. Therefore, we carried out a detailed analysis of phycobilisome dynamics in several red alga strains and compared these results with the presence (or absence) of photoprotective mechanisms. Our data conclusively prove phycobilisome mobility in two model mesophilic red alga strains, Porphyridium cruentum and Rhodella violacea. In contrast, there was almost no phycobilisome mobility in the thermophilic red alga Cyanidium caldarium that was not caused by a decrease in lipid desaturation in this extremophile. Experimental data attributed this immobility to the strong phycobilisome-photosystem interaction that highly restricted phycobilisome movement. Variations in phycobilisome mobility reflect the different ways in which light-harvesting antennae can be regulated in mesophilic and thermophilic red algae. Fluorescence changes attributed in cyanobacteria to state transitions were observed only in mesophilic P. cruentum with mobile phycobilisomes, and they were absent in the extremophilic C. caldarium with immobile phycobilisomes. We suggest that state transitions have an important regulatory function in mesophilic red algae; however, in thermophilic red algae, this process is replaced by nonphotochemical quenching. PMID:24948833

  8. The importance of vertical resolution in sea ice algae production models

    NASA Astrophysics Data System (ADS)

    Duarte, Pedro; Assmy, Philipp; Hop, Haakon; Spreen, Gunnar; Gerland, Sebastian; Hudson, Stephen R.

    2015-05-01

    In this study an ice-algal mathematical model is used to resolve the vertical fine structure of sea ice with ice algae, and results are compared to simulations with ice algae located only at the bottom ice layer and to those where ice algae are distributed homogeneously across part of the ice column. Ice algae are reported to contribute 4-26% of overall Arctic Ocean primary production and are an important food source for the ice-associated ecosystem. Thus, it is important to estimate the future impacts of global warming on the contribution of ice algae to Arctic primary production. Primary production models, describing the relationships between ice-algal physiology and population dynamics, with environmental forcing and trophic interactions involving bacteria and grazers, can be applied to quantify such impacts. One important aspect in these models is how to represent the vertical distribution of ice algae in sea ice. In most models, only the bottom ice layer is considered where most of the algal biomass tends to be concentrated. However, since ice algae are also present along the entire ice column, this may lead to underestimation of ice-algal production. Some empirical data and model results suggest that ice algae located in the surface and interior layers may be kept at lower concentrations, in spite of high growth rates, due to grazing by micro- and meiofauna. Results obtained in this study show the importance of resolving vertically the distribution of ice algae to avoid bias in primary production estimates, well in line with empirical studies.

  9. Energy Productivity of the High Velocity Algae Raceway Integrated Design (ARID-HV)

    SciTech Connect

    Attalah, Said; Waller, Peter M.; Khawam, George; Ryan, Randy D.; Huesemann, Michael H.

    2015-06-03

    The original Algae Raceway Integrated Design (ARID) raceway was an effective method to increase algae culture temperature in open raceways. However, the energy input was high and flow mixing was poor. Thus, the High Velocity Algae Raceway Integrated Design (ARID-HV) raceway was developed to reduce energy input requirements and improve flow mixing in a serpentine flow path. A prototype ARID-HV system was installed in Tucson, Arizona. Based on algae growth simulation and hydraulic analysis, an optimal ARID-HV raceway was designed, and the electrical energy input requirement (kWh ha-1 d-1) was calculated. An algae growth model was used to compare the productivity of ARIDHV and conventional raceways. The model uses a pond surface energy balance to calculate water temperature as a function of environmental parameters. Algae growth and biomass loss are calculated based on rate constants during day and night, respectively. A 10 year simulation of DOE strain 1412 (Chlorella sorokiniana) showed that the ARID-HV raceway had significantly higher production than a conventional raceway for all months of the year in Tucson, Arizona. It should be noted that this difference is species and climate specific and is not observed in other climates and with other algae species. The algae growth model results and electrical energy input evaluation were used to compare the energy productivity (algae production rate/energy input) of the ARID-HV and conventional raceways for Chlorella sorokiniana in Tucson, Arizona. The energy productivity of the ARID-HV raceway was significantly greater than the energy productivity of a conventional raceway for all months of the year.

  10. Platinum Anniversary: Virus and Lichen Alga Together More than 70 Years

    PubMed Central

    Petrzik, Karel; Vondrák, Jan; Kvíderová, Jana; Lukavský, Jaromír

    2015-01-01

    Trebouxia aggregata (Archibald) Gärtner (phylum Chlorophyta, family Trebouxiaceae), a lichen symbiotic alga, has been identified as host of the well-known herbaceous plant virus Cauliflower mosaic virus (CaMV, family Caulimoviridae). The alga had been isolated from Xanthoria parietina more than 70 years ago and has been maintained in a collection since that time. The CaMV detected in this collection entry has now been completely sequenced. The virus from T. aggregata is mechanically transmissible to a herbaceous host and induces disease symptoms there. Its genome differs by 173 nt from the closest European CaMV-D/H isolate from cauliflower. No site under positive selection was found on the CaMV genome from T. aggregata. We therefore assume that the virus’s presence in this alga was not sufficiently long to fix any specific changes in its genome. Apart from this symbiotic alga, CaMV capsid protein sequences were amplified from many other non-symbiotic algae species maintained in a collection (e.g., Oonephris obesa, Elliptochloris sp., Microthamnion kuetzingianum, Chlorella vulgaris, Pseudococcomyxa sp.). CaMV-free Chlorella vulgaris was treated with CaMV to establish virus infection. The virus was still detected there after five passages. The virus infection is morphologically symptomless on Chlorella algae and the photosynthesis activity is slightly decreased in comparison to CaMV-free alga culture. This is the first proof as to the natural presence of CaMV in algae and the first demonstration of algae being artificially infected with this virus. PMID:25789995

  11. Comparing the effects of symbiotic algae (Symbiodinium) clades C1 and D on early growth stages of Acropora tenuis.

    PubMed

    Yuyama, Ikuko; Higuchi, Tomihiko

    2014-01-01

    Reef-building corals switch endosymbiotic algae of the genus Symbiodinium during their early growth stages and during bleaching events. Clade C Symbiodinium algae are dominant in corals, although other clades - including A and D - have also been commonly detected in juvenile Acroporid corals. Previous studies have been reported that only molecular data of Symbiodinium clade were identified within field corals. In this study, we inoculated aposymbiotic juvenile polyps with cultures of clades C1 and D Symbiodinium algae, and investigated the different effect of these two clades of Symbiodinium on juvenile polyps. Our results showed that clade C1 algae did not grow, while clade D algae grew rapidly during the first 2 months after inoculation. Polyps associated with clade C1 algae exhibited bright green fluorescence across the body and tentacles after inoculation. The growth rate of polyp skeletons was lower in polyps associated with clade C1 algae than those associated with clade D algae. On the other hand, antioxidant activity (catalase) of corals was not significantly different between corals with clade C1 and clade D algae. Our results suggested that clade D Symbiodinium algae easily form symbiotic relationships with corals and that these algae could contribute to coral growth in early symbiosis stages. PMID:24914677

  12. Compsopogon cf. coeruleus, a benthic red alga (Rhodophyta) new to the Laurentian Great Lakes

    USGS Publications Warehouse

    Manny, Bruce A.; Edsall, Thomas A.; Wujek, Daniel E.

    1991-01-01

    We found Compsopogon cf. coeruleus for the first time in the Laurentian Great Lakes, growing on limestone rocks at a depth of 21 m on Six Fathom Bank in central Lake Huron. It is the first freshwater red alga to be found in the Great Lakes and the only red alga ever found on an offshore reef in the Great Lakes. However, because this alga usually inhabits water 10-28A?C and has not survived freezing winter temperatures elsewhere, it may not be a permanent member of the flora.

  13. Aquaculture: Algae. (Latest citations from the Life Sciences collection database). Published Search

    SciTech Connect

    1996-04-01

    The bibliography contains citations concerning the commercial cultivation of algae as a facet of aquaculture. Topics include descriptions and characteristics of algal species, environmental variables affecting productivity, nutritional aspects, infestation and disease, genetic manipulation, and production technology. End product applications examine algae as biomass for energy production, food source for humans, animal feed source, and a source for chemical by-products such as chlorophylls. Harvesting of algae as a source of single-celled protein is referenced in a related bibliography. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  14. Aquaculture: Algae. (Latest citations from the Life Sciences Collection data base). Published Search

    SciTech Connect

    Not Available

    1992-05-01

    The bibliography contains citations concerning the commercial cultivation of algae as a facet of aquaculture. Topics include descriptions and characteristics of algal species, environmental variables affecting productivity, nutritional aspects, infestation and disease, genetic manipulation, and production technology. End product applications examine algae as biomass for energy production, food source for humans, animal feed source, and a source for chemical by-products such as chlorophylls. Harvesting of algae as a source of single-celled protein is referenced in a related bibliography. (Contains a minimum of 171 citations and includes a subject term index and title list.)

  15. Use of Copper to Selectively Inhibit Brachionus calyciflorus (Predator) Growth in Chlorella kessleri (Prey) Mass Cultures for Algae Biodiesel Production.

    PubMed

    Pradeep, Vishnupriya; Van Ginkel, Steven W; Park, Sichoon; Igou, Thomas; Yi, Christine; Fu, Hao; Johnston, Rachel; Snell, Terry; Chen, Yongsheng

    2015-01-01

    A single Brachionus rotifer can consume thousands of algae cells per hour causing an algae pond to crash within days of infection. Thus, there is a great need to reduce rotifers in order for algal biofuel production to become reality. Copper can selectively inhibit rotifers in algae ponds, thereby protecting the algae crop. Differential toxicity tests were conducted to compare the copper sensitivity of a model rotifer-B. calyciflorus and an alga, C. kessleri. The rotifer LC50 was <0.1 ppm while the alga was not affected up to 5 ppm Cu(II). The low pH of the rotifer stomach may make it more sensitive to copper. However, when these cultures were combined, a copper concentration of 1.5 ppm was needed to inhibit the rotifer as the alga bound the copper, decreasing its bioavailability. Copper (X ppm) had no effect on downstream fatty acid methyl ester extraction. PMID:26404247

  16. Attraction of gravid anopheles Pseudopunctipennis females to oviposition substrates by Spirogyra majuscula (Zygnematales: Zygnmataceae) algae under laboratory conditions.

    PubMed

    Torres-Estrada, Jos L; Meza-Alvarez, Rosa A; Cruz-Lpez, Leopoldo; Rodrguez, Mario H; Arredondo-Jimnez, Juan I

    2007-03-01

    The attraction of Anopheles pseudopunctipennis gravid females to oviposition substrates containing Spirogyra majuscula algae was investigated under laboratory conditions. Gravid females deposited significantly more eggs in cups containing natural algae in water from breeding sites than in cups containing artificial (nylon rope) life-like algae in water from the corresponding natural breeding site, or in cups containing natural algae in distilled water. Bioassays with Spirogyra majuscula organic extracts indicated that these extracts at concentrations of 0.1%, 0.01%, and 0.001% attracted more oviposition, but concentrations of 1%, 10%, and 100% were repellent. Gas chromatography and mass spectrometry analysis of algae organic extracts revealed a mixture of ethyl acetate and hydrocarbons compounds. These results suggest that the attraction of gravid An. pseudopunctipennis to natural breeding sites containing filamentous algae is probably mediated by organic compounds released by the algae. PMID:17536363

  17. Use of Copper to Selectively Inhibit Brachionus calyciflorus (Predator) Growth in Chlorella kessleri (Prey) Mass Cultures for Algae Biodiesel Production

    PubMed Central

    Pradeep, Vishnupriya; Van Ginkel, Steven W.; Park, Sichoon; Igou, Thomas; Yi, Christine; Fu, Hao; Johnston, Rachel; Snell, Terry; Chen, Yongsheng

    2015-01-01

    A single Brachionus rotifer can consume thousands of algae cells per hour causing an algae pond to crash within days of infection. Thus, there is a great need to reduce rotifers in order for algal biofuel production to become reality. Copper can selectively inhibit rotifers in algae ponds, thereby protecting the algae crop. Differential toxicity tests were conducted to compare the copper sensitivity of a model rotifer—B. calyciflorus and an alga, C. kessleri. The rotifer LC50 was <0.1 ppm while the alga was not affected up to 5 ppm Cu(II). The low pH of the rotifer stomach may make it more sensitive to copper. However, when these cultures were combined, a copper concentration of 1.5 ppm was needed to inhibit the rotifer as the alga bound the copper, decreasing its bioavailability. Copper (X ppm) had no effect on downstream fatty acid methyl ester extraction. PMID:26404247

  18. Impact of green algae on the measurement of Microcystis aeruginosa populations in lagoon-treated wastewater with an algae online analyser.

    PubMed

    Nguyen, Thang; Roddick, Felicity A; Fan, Linhua

    2015-01-01

    Tests on the algae online analyser (AOA) showed that there was a strong direct linear correlation between cell density and in vivo Chl-a concentration for M. aeruginosa over the range of interest for a biologically treated effluent at a wastewater treatment plant (25,000-65,000 cells mL(-1), equivalent to a biovolume of 2-6 mm3 L(-1)). However, the AOA can provide an overestimate or underestimate of M. aeruginosa populations when green algae are present in the effluent, depending on their species and relative numbers. The results from this study demonstrated that the green algae (e.g., Euglena gracilis, Chlorella sp.) in the field phytoplankton population should be considered during calibration. In summary, the AOA has potential for use as an alert system for the presence of M. aeruginosa, and thus potentially of cyanobacterial blooms, in wastewater stabilization ponds. PMID:25204421

  19. EVALUATION OF FILTER FEEDING FISHES FOR REMOVING EXCESSIVE NUTRIENTS AND ALGAE FROM WASTEWATER

    EPA Science Inventory

    The feasibility of utilizing finfish for the removal and recycling of excessive nutrients and algae from wastewater was investigated. The silver carp (Hypopthalmichthyes molitrix) and the bighead carp (Aristichthyes nobilis) were chosen due to their specifically adapted filter fe...

  20. 3D-PTV measurement of the phototactic movement of algae in shear flow

    NASA Astrophysics Data System (ADS)

    Maeda, Tatsuyuki; Ishikawa, Takuji; Ueno, Hironori; Numayama-Tsuruta, Keiko; Imai, Yosuke; Yamaguchi, Takami

    2012-11-01

    Recently, swimming motion of algae cells is researched actively, because algae fuel is one of the hottest topic in engineering. It is known that algae swim toward the light for photosynthesis however, the effect of a background flow on the unidirectional swimming is unclear. In this study, we used Volvox as a model alga and placed them in a simple shear flow with or without light stimulus. The shear flow was generated by moving two flat sheets in the opposite direction tangentially. A red LED light (wave length 660 nm) was used as an observation light source, and a white LED light was used to stimulate cells for the phototaxis. The trajectories of individual cells were measured by a 3D-PTV system, consists of a pair of high-speed camera with macro lenses. The results were analyzed to understand the effect of the background shear flow on the phototaxis of cells.

  1. Aluminum bioavailability to the green alga Chlorella pyrenoidosa in acidified synthetic soft water

    SciTech Connect

    Parent, L.; Campbell, P.G.C. )

    1994-04-01

    A unicellular green alga, Chlorella pyrenoidosa, was exposed to inorganic Al under controlled experimental conditions to determine whether the biological response elicited by the dissolved metal could be predicted from the free-metal ion concentration, [Al[sup 3+

  2. LIPID BIOMARKER CHARACTERIZATION OF BLOOM-RELATED DINOFLAGELLATES AND OTHER EUKARYOTIC ALGAE

    EPA Science Inventory

    Marine eukaryotic algae synthesize an array of lipids of chemotaxonomic utility that are potentially valuable in characterizing phytoplankton communities. Sterols and photopigments characteristic of dinoflagellates are rarely found in other algal classes. Long chain (C28) highly ...

  3. A reaction-diffusion-advection model of harmful algae growth with toxin degradation

    NASA Astrophysics Data System (ADS)

    Wang, Feng-Bin; Hsu, Sze-Bi; Zhao, Xiao-Qiang

    2015-10-01

    This paper is devoted to the study of a reaction-diffusion-advection system modeling the dynamics of a single nutrient, harmful algae and algal toxin in a flowing water habitat with a hydraulic storage zone. We introduce the basic reproduction ratio R0 for algae and show that R0 serves as a threshold value for persistence and extinction of the algae. More precisely, we prove that the washout steady state is globally attractive if R0 < 1, while there exists a positive steady state and the algae is uniformly persistent if R0 > 1. With an additional assumption, we obtain the uniqueness and global attractivity of the positive steady state in the case where R0 > 1.

  4. The Antimicrobial Properties of Red Algae. The Fight of Your Life: Battling Bacteria.

    ERIC Educational Resources Information Center

    Case, Christine L.; Warner, Michael

    2001-01-01

    Describes a research project in which a professor and a student collaborated in the screening of macroscopic algae for antimicrobial properties. Includes background information, materials and methods, results, and a discussion of the experiment. (SAH)

  5. Method and apparatus for detecting phycocyanin-pigmented algae and bacteria from reflected light

    NASA Technical Reports Server (NTRS)

    Vincent, Robert (Inventor)

    2013-01-01

    The present invention relates to a method of detecting phycocyanin algae or bacteria in water from reflected light, and also includes devices for the measurement, calculation and transmission of data relating to that method.

  6. Raman spectroscopy of senescing snow algae: pigmentation changes in an Antarctic cold desert extremophile

    NASA Astrophysics Data System (ADS)

    Edwards, Howell G. M.; de Oliveira, Luiz F. C.; Cockell, Charles S.; Cynan Ellis-Evans, J.; Wynn-Williams, David D.

    2004-04-01

    The FT-Raman spectra are described of green and red snow algae, Chlamydomona, involved in the colonization of exposed surfaces of the McLeod Glacier, Jane Col, Signy Island, situated at the northern edge of the Weddell Sea, Antarctica. The protective biochemicals produced by these extremophilic algae give rise to the so-called watermelon snow of Alpine regions. The red colour of the senescent algae is shown to derive from the accumulation of carotenoids and a deficiency of chlorophyll believed to arise from UV-radiation induced breakdown into phaecophytin. A comparison of the Raman spectra of young (green) and old (red) algae is effected and possible bio-markers for spectral detection on extraterrestrial icy moons and planets are identified.

  7. EFFECTS OF SELECTED WASTEWATER CHLORINATION PRODUCTS AND CAPTAN ON MARINE ALGAE

    EPA Science Inventory

    Effects of stable chloro-organic compounds formed during chlorination of sewage effluents on growth of marine unicellular algae were determined. Captan suppressed growth of Dunaliella tertiolecta and Porphyridium cruentum at 5 ppm. Growth of Skeletonema costatum was inhibited by ...

  8. Preliminary observations on the benthic marine algae of the Gorringe seabank (northeast Atlantic Ocean)

    NASA Astrophysics Data System (ADS)

    Tittley, Ian; da Silva Vaz lvaro, Nuno Miguel; de Melo Azevedo Neto, Ana Isabel

    2014-06-01

    Examination of marine samples collected in 2006 from the Gettysburg and Ormonde seamounts on the Gorringe seabank southwest of Portugal has revealed 29 benthic Chlorophyta, Phaeophyceae (Ochrophyta), and Rhodophyta that were identified provisionally to genus and to species. Combining lists for the present and a previous expedition brings the total of algae thus far recorded to 48. The brown alga Zonaria tournefourtii and the red alga Cryptopleura ramosa were the most abundant species in the present collections. The kelp Laminaria ochroleuca was present only in the Gettysburg samples while Saccorhiza polyschides was observed only on the Ormonde seamount. Comparisons with the benthic marine algae recorded on seamounts in the mid-Atlantic Azores archipelago show features in common, notably kelp forests of L. ochroleuca at depths below 30 m and Z. tournefortii dominance in shallower waters.

  9. Relationship between the Unicellular Red Alga Porphyridium sp. and Its Predator, the Dinoflagellate Gymnodinium sp

    PubMed Central

    Ucko, Michal; Cohen, Ephraim; Gordin, Hillel; Arad, Shoshana (Malis)

    1989-01-01

    Contamination of algae cultivated outdoors by various microorganisms, such as bacteria, fungi, algae, and protozoa, can affect growth and product quality, sometimes causing fast collapse of the cultures. The main contaminant of Porphyridium cultures grown outdoors in Israel is a Gymnodinium sp., a dinoflagellate that feeds on the alga. Comparison of the effects of various environmental conditions, i.e., pH, salinity, and temperature, on Gymnodinium and Porphyridium species revealed that the Gymnodinium sp. has sharp optimum curves, whereas the Porphyridium sp. has a wider range of optimum conditions and is also more resistant to extreme environmental variables. The mode of preying on the alga was observed, and the specificity of the Gymnodinium sp. for the Porphyridium sp. was shown. In addition, Gymnodinium extract was shown to contain enzymatic degrading activity specific to the Porphyridium sp. cell wall polysaccharide. PMID:16348059

  10. CONTRIBUTION OF MARINE ALGAE TO TRIHALOMETHANE PRODUCTION IN CHLORINATED ESTUARINE WATER

    EPA Science Inventory

    Three species of marine algae representing major taxonomic groups of phytoplankton, Isochrysis galbana (Chrysophyceae), Carteria sp. (Chlorophyceae), and Thalassiosira pseudonana (Bacillariphyceae), were utilized to investigate the potential of natural occurring chlorophyll a of ...

  11. [Effects of iron on the algae growth and microcystin synthesis: a review].

    PubMed

    Kong, Yun; Zou, Pei; Song, Li-Ming; Wang, Zi; Qi, Jiao-Qin; Zhu, Liang; Xu, Xiang-Yang

    2014-05-01

    Iron, as one of the essential mineral elements for algae growth, plays an extremely important role in the physiological processes such as plant photosynthesis, respiration, nitrogen fixation, protein and nucleic acid synthesis. In view of the fact that iron in different forms could be absorbed and utilized by algae, the existing forms and circulation approaches in the aquatic environment, the absorption mechanism by algae, and the effects on algae growth and microcystin synthesis were reviewed in this paper. The relevant microcystin synthesis genes and their expression under iron restricted conditions were summarized, and the research directions for harmful algal blooms regulation and control by ferritin genes were suggested. It was hoped to provide the reference for eutrophication remediation technology. PMID:25129959

  12. A new index to assess chemicals increasing the greenhouse effect based on their toxicity to algae.

    PubMed

    Wang, Ting; Zhang, Xiaoxian; Tian, Dayong; Gao, Ya; Lin, Zhifen; Liu, Ying; Kong, Lingyun

    2015-11-01

    CO2, as the typical greenhouse gas causing the greenhouse effect, is a major global environmental problem and has attracted increasing attention from governments. Using algae to eliminate CO2, which has been proposed as an effective way to reduce the greenhouse effect in the past decades, can be disturbed by a growing number of artificial chemicals. Thus, seven types of chemicals and Selenastrum capricornutum (algae) were examined in this study, and the good consistency between the toxicity of artificial chemicals to algae and the disturbance of carbon fixation by the chemicals was revealed. This consistency showed that the disturbance of an increasing number of artificial chemicals to the carbon fixation of algae might be a "malware" worsening the global greenhouse effect. Therefore, this study proposes an original, promising index to assess the risk of deepening the greenhouse effect by artificial chemicals before they are produced and marketed. PMID:26520250

  13. POTENTIAL USE OF BENTHIC ALGAE AS HYDROLOGIC INDICATORS FOR HEADWATER STREAMS: SOME DATA EXPLORATION

    EPA Science Inventory

    Benthic algae were sampled to determine the utility of algal communities as indicators of hydrologic regime as part of a national survey involving habitat measurements and community assessments. Streams from four forests near Cincinnati were classified according to hydrologic pe...

  14. Method and apparatus for detecting phycocyanin-pigmented algae and bacteria from reflected light

    NASA Technical Reports Server (NTRS)

    Vincent, Robert (Inventor)

    2006-01-01

    The present invention relates to a method of detecting phycocyanin algae or bacteria in water from reflected light, and also includes devices for the measurement, calculation and transmission of data relating to that method.

  15. INFLUENCE OF METHYL TERT-BUTYL ETHER (MTBE) ON LAKE WATER ALGAE: JOURNAL ARTICLE

    EPA Science Inventory

    NRMRL-ADA-01209 Kampbell*, D.H., An, Y, and Williams, VR. Influence of Methyl tert-Butyl Ether (MTBE) on Lake Water Algae. Bulletin of Environmental Contamination and Toxicology 57 (4):675-681 (2001). ...

  16. Algae biodiesel life cycle assessment using current commercial data.

    PubMed

    Passell, Howard; Dhaliwal, Harnoor; Reno, Marissa; Wu, Ben; Ben Amotz, Ami; Ivry, Etai; Gay, Marcus; Czartoski, Tom; Laurin, Lise; Ayer, Nathan

    2013-11-15

    Autotrophic microalgae represent a potential feedstock for transportation fuels, but life cycle assessment (LCA) studies based on laboratory-scale or theoretical data have shown mixed results. We attempt to bridge the gap between laboratory-scale and larger scale biodiesel production by using cultivation and harvesting data from a commercial algae producer with ∼1000 m(2) production area (the base case), and compare that with a hypothetical scaled up facility of 101,000 m(2) (the future case). Extraction and separation data are from Solution Recovery Services, Inc. Conversion and combustion data are from the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation Model (GREET). The LCA boundaries are defined as "pond-to-wheels". Environmental impacts are quantified as NER (energy in/energy out), global warming potential, photochemical oxidation potential, water depletion, particulate matter, and total NOx and SOx. The functional unit is 1 MJ of energy produced in a passenger car. Results for the base case and the future case show an NER of 33.4 and 1.37, respectively and GWP of 2.9 and 0.18 kg CO2-equivalent, respectively. In comparison, petroleum diesel and soy diesel show an NER of 0.18 and 0.80, respectively and GWP of 0.12 and 0.025, respectively. A critical feature in this work is the low algal productivity (3 g/m(2)/day) reported by the commercial producer, relative to the much higher productivities (20-30 g/m(2)/day) reported by other sources. Notable results include a sensitivity analysis showing that algae with an oil yield of 0.75 kg oil/kg dry biomass in the future case can bring the NER down to 0.64, more comparable with petroleum diesel and soy biodiesel. An important assumption in this work is that all processes are fully co-located and that no transport of intermediate or final products from processing stage to stage is required. PMID:23900083

  17. Gain and loss of elongation factor genes in green algae

    PubMed Central

    Cocquyt, Ellen; Verbruggen, Heroen; Leliaert, Frederik; Zechman, Frederick W; Sabbe, Koen; De Clerck, Olivier

    2009-01-01

    Background Two key genes of the translational apparatus, elongation factor-1 alpha (EF-1?) and elongation factor-like (EFL) have an almost mutually exclusive distribution in eukaryotes. In the green plant lineage, the Chlorophyta encode EFL except Acetabularia where EF-1? is found, and the Streptophyta possess EF-1? except Mesostigma, which has EFL. These results raise questions about evolutionary patterns of gain and loss of EF-1? and EFL. A previous study launched the hypothesis that EF-1? was the primitive state and that EFL was gained once in the ancestor of the green plants, followed by differential loss of EF-1? or EFL in the principal clades of the Viridiplantae. In order to gain more insight in the distribution of EF-1? and EFL in green plants and test this hypothesis we screened the presence of the genes in a large sample of green algae and analyzed their gain-loss dynamics in a maximum likelihood framework using continuous-time Markov models. Results Within the Chlorophyta, EF-1? is shown to be present in three ulvophycean orders (i.e., Dasycladales, Bryopsidales, Siphonocladales) and the genus Ignatius. Models describing gene gain-loss dynamics revealed that the presence of EF-1?, EFL or both genes along the backbone of the green plant phylogeny is highly uncertain due to sensitivity to branch lengths and lack of prior knowledge about ancestral states or rates of gene gain and loss. Model refinements based on insights gained from the EF-1? phylogeny reduce uncertainty but still imply several equally likely possibilities: a primitive EF-1? state with multiple independent EFL gains or coexistence of both genes in the ancestor of the Viridiplantae or Chlorophyta followed by differential loss of one or the other gene in the various lineages. Conclusion EF-1? is much more common among green algae than previously thought. The mutually exclusive distribution of EF-1? and EFL is confirmed in a large sample of green plants. Hypotheses about the gain-loss dynamics of elongation factor genes are hard to test analytically due to a relatively flat likelihood surface, even if prior knowledge is incorporated. Phylogenetic analysis of EFL genes indicates misinterpretations in the recent literature due to uncertainty regarding the root position. PMID:19216746

  18. Re-utilization of Industrial CO2 for Algae Production Using a Phase Change Material

    SciTech Connect

    Joseph, Brian

    2013-12-31

    This is the final report of a 36-month Phase II cooperative agreement. Under this project, Touchstone Research Laboratory (Touchstone) investigated the merits of incorporating a Phase Change Material (PCM) into an open-pond algae production system that can capture and re-use the CO2 from a coal-fired flue gas source located in Wooster, OH. The primary objective of the project was to design, construct, and operate a series of open algae ponds that accept a slipstream of flue gas from a coal-fired source and convert a significant portion of the CO2 to liquid biofuels, electricity, and specialty products, while demonstrating the merits of the PCM technology. Construction of the pilot facility and shakedown of the facility in Wooster, OH, was completed during the first two years, and the focus of the last year was on operations and the cultivation of algae. During this Phase II effort a large-scale algae concentration unit from OpenAlgae was installed and utilized to continuously harvest algae from indoor raceways. An Algae Lysing Unit and Oil Recovery Unit were also received and installed. Initial parameters for lysing nanochloropsis were tested. Conditions were established that showed the lysing operation was effective at killing the algae cells. Continuous harvesting activities yielded over 200 kg algae dry weight for Ponds 1, 2 and 4. Studies were conducted to determine the effect of anaerobic digestion effluent as a nutrient source and the resulting lipid productivity of the algae. Lipid content and total fatty acids were unaffected by culture system and nutrient source, indicating that open raceway ponds fed diluted anaerobic digestion effluent can obtain similar lipid productivities to open raceway ponds using commercial nutrients. Data were also collected with respect to the performance of the PCM material on the pilot-scale raceway ponds. Parameters such as evaporative water loss, temperature differences, and growth/productivity were tracked. The pond with the PCM material was consistently 2 to 5°C warmer than the control pond. This difference did not seem to increase significantly over time. During phase transitions for the PCM, the magnitude of the difference between the daily minimum and maximum temperatures decreased, resulting in smaller daily temperature fluctuations. A thin layer of PCM material reduced overall water loss by 74% and consistently provided algae densities that were 80% greater than the control pond.

  19. Mass-energy metabolic characteristics of algae. [for spacecraft life support system

    NASA Technical Reports Server (NTRS)

    Smirnov, I. V.

    1973-01-01

    A mathematical analysis is given for the mass energy characteristics of photosynthesizing algae. An engineering-biological approach to this allows for a detailed analysis of the characteristics for a broad spectrum of environmental situations in which such algae are used as a component of a life support system. Models of such systems are constructed and are employed to demonstrate actual and hypothetical situations. Computers are employed for this purpose.

  20. Behavioural and physical effects of arsenic exposure in fish are aggravated by aquatic algae.

    PubMed

    Magellan, Kit; Barral-Fraga, Laura; Rovira, Marona; Srean, Pao; Urrea, Gemma; Garca-Berthou, Emili; Guasch, Helena

    2014-11-01

    Arsenic contamination has global impacts and freshwaters are major arsenic repositories. Arsenic toxicity depends on numerous interacting factors which makes effects difficult to estimate. The use of aquatic algae is often advocated for bioremediation of arsenic contaminated waters as they absorb arsenate and transform it into arsenite and methylated chemical species. Fish are another key constituent of aquatic ecosystems. Contamination in natural systems is often too low to cause mortality but sufficient to interfere with normal functioning. Alteration of complex, naturally occurring fish behaviours such as foraging and aggression are ecologically relevant indicators of toxicity and ideal for assessing sublethal impacts. We examined the effects of arsenic exposure in the invasive mosquitofish, Gambusia holbrooki, in a laboratory experiment incorporating some of the complexity of natural systems by including the interacting effects of aquatic algae. Our aims were to quantify the effects of arsenic on some complex behaviours and physical parameters in mosquitofish, and to assess whether the detoxifying mechanisms of algae would ameliorate any effects of arsenic exposure. Aggression increased significantly with arsenic whereas operculum movement decreased non-significantly and neither food capture efficiency nor consumption were notably affected. Bioaccumulation increased with arsenic and unexpectedly so did fish biomass. Possibly increased aggression facilitated food resource defence allowing fish to gain weight. The presence of algae aggravated the effects of arsenic exposure. For increase in fish biomass, algae acted antagonistically with arsenic, resulting in a disadvantageous reduction in weight gained. For bioaccumulation the effects were even more severe, as algae operated additively with arsenic to increase arsenic uptake and/or assimilation. Aggression was also highest in the presence of both algae and arsenic. Bioremediation of arsenic contaminated waters using aquatic algae should therefore be carried out with consideration of entire ecosystem effects. We highlight that multidisciplinary, cross-taxon research, particularly integrating behavioural and other effects, is crucial for understanding the impacts of arsenic toxicity and thus restoration of aquatic ecosystems. PMID:25190483

  1. Effect of selenium on the lipids of two unicellular marine algae

    SciTech Connect

    Gennity, J.M.

    1983-01-01

    The incorporation of selenium into the lipids of two unicellar marine algae has been investigated. Axenic cultures of the green algae Dunaliella primolecta and the red algae Porphyridium cruentum were grown in the presence of sublethal quantities of selenium (10 ppm) as selenite. Both algae were found to contain selenium bound to all purified lipids, except for saturated hydrocarbons. Of the lipids which contain selenium, carotenoid pigments show the greatest selenium concentration (..beta..-carotene: 1.3..mu..gSe/mg lipid; zeaxanthin: 1.1..mu..gSe/mg lipid) in both algae. P. cruentum contains about ten times as much lipid-associated selenium as D. primolecta, even though the lipids of both algae were very similar. This selenium has been shown to be incorporated non-metabolically into the lipid molecule. The lipid-associated selenium is probably non-covalently bound to the lipid molecule and may interact with double bonds. Selenite does not affect the lipid composition of D. primolecta, as compared with algae grown in the absence of added selenium. A selenium-induced 40% decrease in the cell content of eicosapentaenoic acid (20:5omega3) and 20% decrease in arachidonic acid (20:4omega6) in polar lipids (glycolipids plus phospholipids) was observed in P. cruentum. A 25% decrease in the chlorophyll a content of this red algae also occurred. The cell content of other fatty acids, phospholipids and glycolipids was unaltered by selenium. These results are consistent with a selenite-induced oxidation of P. cruentum lipids. Selenium is able to increase the antioxidant potential of algal cells. However, no in vivo selenium-induced protection of algal lipids from oxidation was apparent.

  2. The relationship between fish abundance and algal biomass in a seagrass-drift algae community

    NASA Astrophysics Data System (ADS)

    Kulczycki, George R.; Virnstein, Robert W.; Nelson, Walter G.

    1981-03-01

    Repetitive seine and monthly drop net samples taken in a seagrass bed in the Indian River, Florida, indicate that significant relationships exist between the abundances of both the code goby Gobiosoma robustum and the gulf pipefish Syngnathus scovelli and drift algae biomass. We suggest that drift algae provides a refuge from predation which increases in effectiveness with increased algal biomass, and that this interaction, in concert with habitat preference and food availability, is responsible for the relationships observed.

  3. Drifting algae and fish: Implications of tropical Sargassum invasion due to ocean warming in western Japan

    NASA Astrophysics Data System (ADS)

    Yamasaki, Mami; Aono, Mikina; Ogawa, Naoto; Tanaka, Koichiro; Imoto, Zenji; Nakamura, Yohei

    2014-06-01

    Evidence is accumulating that the invasion and extinction of habitat-forming seaweed species alters coastal community structure and ecological services, but their effects on the pelagic environment have been largely ignored. Thus, we examined the seasonal occurrence patterns of indigenous temperate and invasive tropical drifting algae and associated fish species every month for 2 years (2009-2011) in western Japan (Tosa Bay), where a rapid shift from temperate to tropical Sargassum species has been occurring in the coastal area since the late 1980s due to rising seawater temperatures. Of the 19 Sargassum species (31.6%) in drifting algae, we found that six were tropical species, whereas a study in the early 1980s found only one tropical species among 12 species (8.3%), thereby suggesting an increase in the proportion of tropical Sargassum species in drifting algae during the last 30 years. Drifting temperate algae were abundantly present from late winter to summer, whereas tropical algal clumps occurred primarily during summer. In the warm season, fish assemblages did not differ significantly between drifting temperate and tropical algae, suggesting the low host-algal specificity of most fishes. We also found that yellowtail juveniles frequently aggregated with drifting temperate algae from late winter to spring when drifting tropical algae were unavailable. Local fishermen collect these juveniles for use as aquaculture seed stock; therefore, the occurrence of drifting temperate algae in early spring is important for local fisheries. These results suggest that the further extinction of temperate Sargassum spp. may have negative impacts on the pelagic ecosystem and associated regional fisheries.

  4. Antibacterial substances from marine algae isolated from Jeddah coast of Red sea, Saudi Arabia.

    PubMed

    Al-Saif, Sarah Saleh Abdu-Llah; Abdel-Raouf, Nevein; El-Wazanani, Hend A; Aref, Ibrahim A

    2014-01-01

    Marine algae are known to produce a wide variety of bioactive secondary metabolites and several compounds have been derived from them for prospective development of novel drugs by the pharmaceutical industries. However algae of the Red sea have not been adequately explored for their potential as a source of bioactive substances. In this context Ulva reticulata, Caulerpa occidentalis, Cladophora socialis, Dictyota ciliolata, and Gracilaria dendroides isolated from Red sea coastal waters of Jeddah, Saudi Arabia, were evaluated for their potential for bioactivity. Extracts of the algae selected for the study were prepared using ethanol, chloroform, petroleum ether and water, and assayed for antibacterial activity against Escherichia coli ATCC 25322, Pseudomonas aeruginosa ATCC 27853, Stapylococcus aureus ATCC 29213, and Enterococcus faecalis ATCC 29212. It was found that chloroform was most effective followed by ethanol, petroleum ether and water for the preparation of algal extract with significant antibacterial activities, respectively. Results also indicated that the extracts of red alga G. dendroides were more efficient against the tested bacterial strains followed by green alga U. reticulata, and brown algae D. ciliolata. Chemical analyses showed that G. dendroides recorded the highest percentages of the total fats and total proteins, followed by U. reticulata, and D. ciliolate. Among the bioflavonoids determined Rutin, Quercetin and Kaempherol were present in high percentages in G. dendroides, U. reticulata, and D. ciliolate. Estimation of saturated and unsaturated fatty acids revealed that palmitic acid was present in highest percentage in all the algal species analyzed. Amino acid analyses indicated the presence of free amino acids in moderate contents in all the species of algae. The results indicated scope for utilizing these algae as a source of antibacterial substances. PMID:24596500

  5. Antibacterial substances from marine algae isolated from Jeddah coast of Red sea, Saudi Arabia

    PubMed Central

    Al-Saif, Sarah Saleh Abdu-llah; Abdel-Raouf, Nevein; El-Wazanani, Hend A.; Aref, Ibrahim A.

    2013-01-01

    Marine algae are known to produce a wide variety of bioactive secondary metabolites and several compounds have been derived from them for prospective development of novel drugs by the pharmaceutical industries. However algae of the Red sea have not been adequately explored for their potential as a source of bioactive substances. In this context Ulva reticulata, Caulerpa occidentalis, Cladophora socialis, Dictyota ciliolata, and Gracilaria dendroides isolated from Red sea coastal waters of Jeddah, Saudi Arabia, were evaluated for their potential for bioactivity. Extracts of the algae selected for the study were prepared using ethanol, chloroform, petroleum ether and water, and assayed for antibacterial activity against Escherichia coli ATCC 25322, Pseudomonas aeruginosa ATCC 27853, Stapylococcus aureus ATCC 29213, and Enterococcus faecalis ATCC 29212. It was found that chloroform was most effective followed by ethanol, petroleum ether and water for the preparation of algal extract with significant antibacterial activities, respectively. Results also indicated that the extracts of red alga G. dendroides were more efficient against the tested bacterial strains followed by green alga U. reticulata, and brown algae D. ciliolata. Chemical analyses showed that G. dendroides recorded the highest percentages of the total fats and total proteins, followed by U. reticulata, and D. ciliolate. Among the bioflavonoids determined Rutin, Quercetin and Kaempherol were present in high percentages in G. dendroides, U. reticulata, and D. ciliolate. Estimation of saturated and unsaturated fatty acids revealed that palmitic acid was present in highest percentage in all the algal species analyzed. Amino acid analyses indicated the presence of free amino acids in moderate contents in all the species of algae. The results indicated scope for utilizing these algae as a source of antibacterial substances. PMID:24596500

  6. Endolithic algae and micrite envelope formation in Bahamian oolites as revealed by scanning electron microscopy.

    NASA Technical Reports Server (NTRS)

    Margolis, S.; Rex, R. W.

    1971-01-01

    Examination of Holocene Bahamian ooelites by scanning electron and light microscopy has revealed the morphology and orientation of aragonite crystals in the lamellar ooelitic envelope, and their modification by the boring activities of endolithic algae. The voids produced by these algae are found in progressive stages of being lined and filled with precipitated microcrystalline aragonite, which is similar to the process of micrite envelope formation in molluscan and other skeletal carbonate grains.

  7. The growth and harvesting of algae in a micro-gravity environment

    NASA Technical Reports Server (NTRS)

    Wiltberger, Nancy L.

    1987-01-01

    Algae growth in a micro-gravity environment is an important factor in supporting man's permanent presence in space. Algae can be used to produce food, oxygen, and pure water in a manned space station. A space station is one example of a situation where a Controlled Ecological Life Support System (CELSS) is imperative. In setting up a CELSS with an engineering approach at the Aerospace department of the University of Colorado, questions concerning algae growth in micro-g have arisen. The Get Away Special (GAS) Fluids Management project is a means through which many questions about the effects of a micro-g environment on the adequacy of growth rates, the viability of micro-organisms, and separation of gases and solids for harvesting purposes can be answered. In order to be compatible with the GAS tests, the algae must satisfy the following criteria: (1) rapid growth rates, (2) sustain viability over long periods of non-growth storage, and (3) very brief latency from storage to rapid growth. Testing indicates that the overall growth characteristics of Anacystis Nidulans satisfy the specifications of GAS's design constraints. In addition, data acquisition and the method of growth instigation are two specific problems being examined, as they will be encountered in interfacing with the GAS project. Flight testing will be two-fold, measurement of algae growth in micro-g and separation of algae from growth medium in an artificial gravitation field. Post flight results will provide information on algae viability in a micro-g environment as reflected by algal growth rates in space. Other post flight results will provide a basis for evaluating techniques for harvesting algae. The results from the GAS project will greatly assist the continuing effort of developing the CELSS and its applications for space.

  8. Reviews and syntheses: Calculating the global contribution of coralline algae to total carbon burial

    NASA Astrophysics Data System (ADS)

    van der Heijden, L. H.; Kamenos, N. A.

    2015-11-01

    The ongoing increase in anthropogenic carbon dioxide (CO2) emissions is changing the global marine environment and is causing warming and acidification of the oceans. Reduction of CO2 to a sustainable level is required to avoid further marine change. Many studies investigate the potential of marine carbon sinks (e.g. seagrass) to mitigate anthropogenic emissions, however, information on storage by coralline algae and the beds they create is scant. Calcifying photosynthetic organisms, including coralline algae, can act as a CO2 sink via photosynthesis and CaCO3 dissolution and act as a CO2 source during respiration and CaCO3 production on short-term timescales. Long-term carbon storage potential might come from the accumulation of coralline algae deposits over geological timescales. Here, the carbon storage potential of coralline algae is assessed using meta-analysis of their global organic and inorganic carbon production and the processes involved in this metabolism. Net organic and inorganic production were estimated at 330 g C m-2 yr-1 and 900 g CaCO3 m-2 yr-1 respectively giving global organic/inorganic C production of 0.7/1.8 × 109 t C yr-1. Calcium carbonate production by free-living/crustose coralline algae (CCA) corresponded to a sediment accretion of 70/450 mm kyr-1. Using this potential carbon storage for coralline algae, the global production of free-living algae/CCA was 0.4/1.2 × 109 t C yr-1 suggesting a total potential carbon sink of 1.6 × 109 tonnes per year. Coralline algae therefore have production rates similar to mangroves, salt marshes and seagrasses representing an as yet unquantified but significant carbon store, however, further empirical investigations are needed to determine the dynamics and stability of that store.

  9. Development of a ground-based space micro-algae photo-bioreactor

    NASA Astrophysics Data System (ADS)

    Ai, W.; Guo, S.; Qin, L.; Tang, Y.

    The purpose of the research is to develop a photo-bioreactor which may produce algae protein and oxygen for future astronauts in comparatively long-term exploration, and remove carbon dioxide in a controlled ecological life support system. Based on technical parameters and performance requirements, the project planning, design drafting, and manufacture were conducted. Finally, a demonstration test for producing algae was done. Its productivity for micro-algae and performance of the photo-bioreactor were evaluated. The facility has nine subsystems, including the reactor, the illuminating unit, the carbon dioxide (CO2) production unit and oxygen (O2) generation unit, etc. The demonstration results showed that the facility worked well, and the parameters, such as energy consumption, volume, and productivity for algae, met with the design requirement. The density of algae in the photo-bioreactor increased from 0.174 g (dry weight) L-1 to 4.064 g (dry weight) L-1 after 7 days growth. The principle of providing CO2 in the photo-bioreactor for algae and removing O2 from the culture medium was suitable for the demand of space conditions. The facility has reasonable technical indices, and smooth and dependable performances.

  10. [Lake algae chemotaxonomy technology based on fluorescence excitation emission matrix and parallel factor analysis].

    PubMed

    Chen, Xiao-Na; Han, Xiu-Rong; Su, Rong-Guo; Shi, Xiao-Yong

    2014-03-01

    An in vivo three-dimensional fluorescence method for the determination of algae community structure was developed by parallel factor (PARAFAC) analysis and CHEMTAX. The PARAFAC model was applied to fluorescence excitation-emission matrix (EEM) of 23 algae species and 12 fluorescent components were identified according to the residual sum of squares and specificity of the composition profiles of fluorescent. Based on the 12 fluorescent components, the algae species at different growth stages were correctly classified at the division level using Bayesian discriminant analysis (BDA). Then the reference fluorescent component ratio matrix was constructed for CHEMTAX, and the EEM-PARAFAC-CHEMTAX method was developed to differentiate taxonomic groups of algae. When the fluorometric method was used for 531 single-species samples, the average correct discrimination ratio (CDR) was 99.1% and the correct discrimination ratios (CDRs) were 100% at the division level except Chlorophyta, the CDR of which was 97.5%. The CDRs for 95 mixtures were above 98.5% for the dominant algae species and above 90.5% for the subdominant algae species, with average relative contents of 69.7% and 26.4%, respectively. This technique would be of great aid when low-cost and rapid analysis is needed for samples in a large batch. PMID:24881379

  11. Microcontact imprinting of algae on poly(ethylene-co-vinyl alcohol) for biofuel cells.

    PubMed

    Chen, Wen-Janq; Lee, Mei-Hwa; Thomas, James L; Lu, Po-Hsun; Li, Ming-Huan; Lin, Hung-Yin

    2013-11-13

    Hydrogen can be produced using microorganisms (e.g., bacteria and algae); algal production has the additional ecological benefit of carbon dioxide fixation. The conversion of hydrogen to electricity via fuel cells may be more efficient compared to other energy sources of electricity. However, the anode of biofuel cells requires the immobilization of microorganisms or enzymes. In this work, poly(ethylene-co-vinyl alcohol) (EVAL), was coated on the electrode, and green algae was microcontact imprinted onto the EVAL film. The readsorption of algae onto algae-imprinted EVAL thin films was compared to determine the ethylene content that gave highest imprinting effectiveness and algal binding. Scanning electron microscopy and fluorescence spectrometry were employed to characterize the surface morphology, recognition capacity, and reusability of the algae-imprinted cavities. The recognition of an individual algal cell by binding to the imprinted cavities was directly observed by video microscopy. Finally, the power and current density of the algal biofuel cell using the algae-imprinted EVAL-coated electrode were measured at about 2-fold higher than electrode sputtered platinum on poly(ethylene terephthalate). PMID:24095224

  12. The blue water footprint and land use of biofuels from algae

    NASA Astrophysics Data System (ADS)

    Gerbens-Leenes, P. W.; Xu, L.; Vries, G. J.; Hoekstra, A. Y.

    2014-11-01

    Biofuels from microalgae are potentially important sources of liquid renewable energy. Algae are not yet produced on a large scale, but research shows promising results. This study assesses the blue water footprint (WF) and land use of algae-based biofuels. It combines the WF concept with an energy balance approach to determine the blue WF of net energy. The study considers open ponds and closed photobioreactors (PBRs). All systems have a positive energy balance, with output-input ratios ranging between 1.13 and 1.98. This study shows that the WF of algae-based biofuels lies between 8 and 193 m3/GJ net energy provided. The land use of microalgal biofuels ranges from 20 to 200 m2/GJ net energy. For a scenario in which algae-based biofuels provide 3.5% of the transportation fuels in the European Union in 2030, the system with the highest land productivity needs 17,000 km2 to produce the 850 PJ/yr. Producing all algae-based biofuels through the system with the highest water productivity would lead to a blue WF of 7 Gm3/yr, which is equivalent to 15% of the present blue WF in the EU28. A transition to algae-based transportation fuels will substantially increase competition over water and land resources.

  13. Endolithic community composition of Orbicella faveolata (Scleractinia) underneath the interface between coral tissue and turf algae

    NASA Astrophysics Data System (ADS)

    Gutiérrez-Isaza, N.; Espinoza-Avalos, J.; León-Tejera, H. P.; González-Solís, D.

    2015-06-01

    We evaluated the species composition, richness, and total abundance of the endolithic community in the skeleton of Orbicella faveolata under coral tissue and under turf algae using cores that were extracted at different distances (0.5, 2.5, and 7.0 cm) from both sides of the external coral tissue-turf algae competitive boundary. We found high endolith richness as never before reported for Orbicella species. Nineteen endolith taxa were found within the O. faveolata skeleton, seven below the coral tissue zone, and twelve exclusively below the turf algae zone. Significant differences existed in the community composition, species richness, and the total abundance of endoliths in the cores that were extracted from the turf algae zone compared with those of the coral tissue zone. The endolithic community composition and species richness changed abruptly across the coral-turf algae interface, forming a clear boundary between different endolithic communities just underneath the interface between the coral tissue and turf algae zones.

  14. Can stormwater be detected by algae in an urban reef in Hawai'i?

    PubMed

    Erin Cox, T; Smith, Celia M; Popp, Brian N; Foster, Michael S; Abbott, Isabella A

    2013-06-15

    Nitrogen (N) enrichment of tropical reefs can result in the dominance of invasive algae. The invasive alga Acanthophora spicifera and the native alga Laurencia nidifica are part of a diverse reef assemblage in 'Ewa Beach, O'ahu. Their N contents and ?(15)N values were investigated to determine if N was enriched and to evaluate potential nitrogenous sources near and removed from storm-drain outlets. ?(15)N values of algae (3.8-17.7) were within and above the range for algae around the island (1.9-11.9). Elevated algae N isotope values (?(15)N>+7, [N]>1.6%) and seawater nitrate+nitrite levels (0.59-7.93 ?M) indicated a mixed, high nutrient environment. The overlap in ?(15)N values with multiple nitrogenous sources precluded identification. However, spatial and temporal patterns did not support stormwater as the dominant, nitrogenous source. Patterns were congruent with algal incorporation of terrestrial derived N, subjected to a high degree of biogeochemical cycling. PMID:23643406

  15. The Cell Walls of Green Algae: A Journey through Evolution and Diversity

    PubMed Central

    Domozych, David S.; Ciancia, Marina; Fangel, Jonatan U.; Mikkelsen, Maria Dalgaard; Ulvskov, Peter; Willats, William G. T.

    2012-01-01

    The green algae represent a large group of morphologically diverse photosynthetic eukaryotes that occupy virtually every photic habitat on the planet. The extracellular coverings of green algae including cell walls are also diverse. A recent surge of research in green algal cell walls fueled by new emerging technologies has revealed new and critical insight concerning these coverings. For example, the late divergent taxa of the Charophycean green algae possess cell walls containing assemblages of polymers with notable similarity to the cellulose, pectins, hemicelluloses, arabinogalactan proteins (AGPs), extensin, and lignin present in embryophyte walls. Ulvophycean seaweeds have cell wall components whose most abundant fibrillar constituents may change from cellulose to ?-mannans to ?-xylans and during different life cycle phases. Likewise, these algae produce complex sulfated polysaccharides, AGPs, and extensin. Chlorophycean green algae produce a wide array of walls ranging from cellulosepectin complexes to ones made of hydroxyproline-rich glycoproteins. Larger and more detailed surveys of the green algal taxa including incorporation of emerging genomic and transcriptomic data are required in order to more fully resolve evolutionary trends within the green algae and in relationship with higher plants as well as potential applications of wall components in the food and pharmaceutical industries. PMID:22639667

  16. In Silico Analysis of Correlations between Protein Disorder and Post-Translational Modifications in Algae

    PubMed Central

    Kurotani, Atsushi; Sakurai, Tetsuya

    2015-01-01

    Recent proteome analyses have reported that intrinsically disordered regions (IDRs) of proteins play important roles in biological processes. In higher plants whose genomes have been sequenced, the correlation between IDRs and post-translational modifications (PTMs) has been reported. The genomes of various eukaryotic algae as common ancestors of plants have also been sequenced. However, no analysis of the relationship to protein properties such as structure and PTMs in algae has been reported. Here, we describe correlations between IDR content and the number of PTM sites for phosphorylation, glycosylation, and ubiquitination, and between IDR content and regions rich in proline, glutamic acid, serine, and threonine (PEST) and transmembrane helices in the sequences of 20 algae proteomes. Phosphorylation, O-glycosylation, ubiquitination, and PEST preferentially occurred in disordered regions. In contrast, transmembrane helices were favored in ordered regions. N-glycosylation tended to occur in ordered regions in most of the studied algae; however, it correlated positively with disordered protein content in diatoms. Additionally, we observed that disordered protein content and the number of PTM sites were significantly increased in the species-specific protein clusters compared to common protein clusters among the algae. Moreover, there were specific relationships between IDRs and PTMs among the algae from different groups. PMID:26307970

  17. [Photoreduction of Se (VI) by marine algae-transitional metals-light system].

    PubMed

    Li, Shun-Xing; Zheng, Feng-Ying; Deng, Nan-Sheng; Hong, Hua-Sheng; Zhu, Guo-Hui

    2005-07-01

    Seven marine phytoplankton, including five green algae (Tetraselmis levis, Chlorella autotrophica, Dunaliella salina, Nannochloropsis sp. and Tetraselmis subcordiformis), one diatom (Phaeodactylum tricornutum), one red alga (Porphyridium purpureum), and three usual transitional metals (Fe(III), Cu(II), Mn(II)) were used to make up marine phytoplankton-light or transitional metals-light or marine phytoplankton-transitional metals-light system. In such system, Se(VI) could be transformed into Se(IV) by photoreduction. The species transformation of selenium could be photo-induced by redox reaction of transitional metals. The photochemical activity of marine phytoplankton was confirmed for the first time, because marine phytoplankton could adsorb and concentrated of selenium, transitional metals and organic substances (including the exudation of algae, as reducing agent) which redox potentials were changed. The ratios of Se(VI) to Se(IV) were dominated by the species, the concentration of marine phytoplankton and transitional metals, and it could be enhanced through increasing the concentration of marine algae or the combined effect from marine algae and transitional metals. After photoreduction by ternary system, the ratio of Se(VI) to Se(IV) ranges from 1.17 to 2.85, which is close to the actual value in euphotic layer of seawater. The photochemical process that is induced by marine algae and transitional metals dominative the leading effects on the distribution of oxidation states of selenium. PMID:16212166

  18. Sorption of copper(II) ions in the biomass of alga Spirogyra sp.

    PubMed

    Rajfur, Małgorzata; Kłos, Andrzej; Wacławek, Maria

    2012-10-01

    Sorption of copper ions by the alga Spirogyra sp. was investigated to determine the influence of experimental conditions and the methods of sample preparation on the process. The experiments were carried out both under the static and the dynamic conditions. Kinetics and equilibrium parameters of the sorption were evaluated. In addition, the influence was studied of the algae preparation methods on the conductivity of demineralized water in which the algae samples were immersed. The static experiments showed that the sorption of Cu(2+) ions reached equilibrium in about 30 min, with approximately 90% of the ions adsorbed in the initial 15 min. The sorption capacity determined from the Langmuir isotherms appeared highly uncertain (SD=±0.027 mg/g dry mass or ±11%, for the live algae). Under static conditions, the slopes of the Langmuir isotherms depended on the ratio of the alga mass to the volume of solution. The conductometric measurements were proven to be a simple and fast way to evaluate the quality of algae used for the experiments. PMID:22245248

  19. Novel fungal pelletization-assisted technology for algae harvesting and wastewater treatment.

    PubMed

    Zhou, Wenguang; Cheng, Yanling; Li, Yun; Wan, Yiqin; Liu, Yuhuan; Lin, Xiangyang; Ruan, Roger

    2012-05-01

    A novel fungi pelletization-assisted bioflocculation technology was developed for efficient algae harvesting and wastewater treatment. Microalga Chlorella vulgaris UMN235 and two locally isolated fungal species Aspergillus sp. UMN F01 and UMN F02 were used to study the effect of various cultural conditions on pelletization process for fungi-algae complex. The results showed that pH was the key factor affecting formation of fungi-algae pellet, and pH could be controlled by adjusting glucose concentration and fungal spore number added. The best pelletization happened when adding 20 g/L glucose and approximately 1.2E8/L spores in BG-11 medium, under which almost 100% of algal cells were captured onto the pellets with shorter retention time. The fungi-algae pellets can be easily harvested by simple filtration due to its large size (2-5 mm). The filtered fungi-algae pellets were reused as immobilized cells for treatment wastewaters and the nutrient removal rates of 100, 58.85, 89.83, and 62.53 % (for centrate) and 23.23, 44.68, 84.70, and 70.34% (for diluted swine manure wastewater) for ammonium, total nitrogen, total phosphorus, and chemical oxygen demand, respectively, under both 1- and 2-day cultivations. The novel technology developed is highly promising compared with current algae harvesting and biological wastewater treatment technologies in the literature. PMID:22538982

  20. Enhanced electricity generation by using algae biomass and activated sludge in microbial fuel cell.

    PubMed

    Rashid, Naim; Cui, Yu-Feng; Saif Ur Rehman, Muhammad; Han, Jong-In

    2013-07-01

    Recently, interest is growing to explore low-cost and sustainable means of energy production. In this study, we have exploited the potential of sustainable energy production from wastes. Activated sludge and algae biomass are used as substrates in microbial fuel cell (MFC) to produce electricity. Activated sludge is used at anode as inoculum and nutrient source. Various concentrations (1-5 g/L) of dry algae biomass are tested. Among tested concentrations, 5 g/L (5000 mg COD/L) produced the highest voltage of 0.89 V and power density of 1.78 W/m(2) under 1000 Ω electric resistance. Pre-treated algae biomass and activated sludge are also used at anode. They give low power output than without pre-treatment. Spent algae biomass is tested to replace whole (before oil extraction) algae biomass as a substrate, but it gives low power output. This work has proved the concept of using algae biomass in MFC for high energy output. PMID:23584037