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1

Active hydrocarbon biosynthesis and accumulation in a green alga, Botryococcus braunii (race A).  

PubMed

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 [(14)C]acetate. Incorporation of (14)C 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

Hirose, Mana; Mukaida, Fukiko; Okada, Sigeru; Noguchi, Tetsuko

2013-08-01

2

Colony Organization in the Green Alga Botryococcus braunii is Specified by a Complex Extracellular Matrix  

SciTech Connect

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 quickfreeze 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.

Weiss, Taylor [Texas A& M University; Roth, Robyn [Washington University of St. Louis; Goodson, Carrie [Washington University of St. Louis; Vithda, Stanislav [Texas A& M University; Black, Ian [University of Georgia; Azadi, Parastoo [University of Georgia; Rusch, Jannette [Washington University of St. Louis; Holzenburg, Andreas [Texas A& M University; Devarenne, Timothy [Texas A& M University; Goodenough, Ursula [Washington University of St. Louis

2012-01-01

3

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

SciTech Connect

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.

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

1980-01-01

4

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

PubMed Central

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

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

2013-01-01

5

Preservation of proteinaceous material during the degradation of the green alga Botryococcus braunii: A solid-state 2D 15N 13C NMR spectroscopy study  

Microsoft Academic Search

Using solid-state cross-polarization-magic-angle-spinning (CPMAS) 13C and 15N nuclear magnetic resonance (NMR) and 2-D double cross polarization (DCP) MAS 15N 13C NMR techniques, microbially degraded Botryococcus braunii was analyzed to study the chemical nature of organic nitrogen in the algal residue. The amide linkage, as found in protein, was observed as the major nitrogen component in 201-day-old degraded algae. No significant

Xu Zang; Reno T. Nguyen; H. Rodger Harvey; Heike Knicker; Patrick G. Hatcher

2001-01-01

6

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

PubMed Central

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

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

2012-01-01

7

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

PubMed

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

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

8

Preservation via macromolecular associations during Botryococcus braunii decay: proteins in the Pula Kerogen  

Microsoft Academic Search

The green alga Botryococcus braunii was degraded for 201 days under oxic conditions in a flow-through system to test whether the macromolecular algaenan surrounding cells could protect proteins from rapid degradation. Protein loss was ?8× slower for B. braunii than for other previously studied phytoplankton, with base extraction consistently removing only a small fraction (<35%) of the total proteinaceous material

Reno T. Nguyen; H. Rodger Harvey

2003-01-01

9

Cultivation of green alga Botryococcus braunii in raceway, circular ponds under outdoor conditions and its growth, hydrocarbon production.  

PubMed

The present study focused on cultivation, seasonal variation in growth, hydrocarbon production, fatty acids profiles of Botryococcus braunii (LB-572 and N-836) in raceway & circular ponds under outdoor conditions. After 18days of cultivation the biomass yield and hydrocarbon contents were increased in both raceway and circular ponds. The fat content was found to be around 24% (w/w) with palmitic and oleic acids as prominent fatty acids. Hydrocarbons of C(20)-C(30) carbon chain length were higher in raceway and circular ponds. Maximum biomass yield (2gL(-1)) and hydrocarbon content (28%) were observed in Nov-Dec. In case of B. braunii (N-836) after 25days of cultivation the biomass yield was 1gL(-1) and hydrocarbon content was 27%. Supplementation of 0.1% NaHCO(3) in the medium resulted in biomass yield of 1.5gL(-1) and hydrocarbon content of 30% compared to control. PMID:22940364

Ranga Rao, A; Ravishankar, G A; Sarada, R

2012-11-01

10

High biofuel production of Botryococcus braunii using optimized cultivation strategies.  

E-print Network

??This thesis describes how using a heterotrophy-recovery-autotrophy route (called the green cycle) for the cultivation of Botryococcus braunii results in high biofuel production. Our experiments… (more)

Yu, Wei

2014-01-01

11

Botryococcus braunii : a rich source for hydrocarbons and related ether lipids  

Microsoft Academic Search

This paper presents a review on Botryococcus braunii, a cosmopolitan green colonial microalga characterised by a considerable production of lipids, notably hydrocarbons. Strains like wild populations of this alga differ in the type of hydrocarbons they synthesise and accumulate: (1) n-alkadienes and trienes, (2) triterpenoid botryococcenes and methylated squalenes, or (3) a tetraterpenoid, lycopadiene. In addition to hydrocarbons and some

P. Metzger; C. Largeau

2005-01-01

12

Functional Identification of Triterpene Methyltransferases from Botryococcus braunii Race B*  

PubMed Central

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

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

2012-01-01

13

Molecular and Biochemical Characterization of Hydrocarbon Production in the Green Microalga Botryococcus braunii  

E-print Network

Botryococcus braunii (Chlorophyta, Botryococcaceae) is a colony-forming green microalga that produces large amounts of liquid hydrocarbons, which can be converted into transportation fuels. While B. braunii has been well studied for the chemistry...

Weiss, Taylor Leigh

2012-10-19

14

Antioxidant activity of Botryococcus braunii extract elucidated in vitro models.  

PubMed

Botryococcus braunii is a green colonial microalga that is used mainly for the production of hydrocarbons, exopolysaccharides, and carotenoids. In the present study, the antioxidant properties of acetone extracts of B. braunii were evaluated using in vitro model systems such as 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxy radical scavenging, and lipid peroxidation in human low-density lipoprotein and rat tissues. Acetone extracts of B. braunii (equivalent to 10 ppm total carotenoid) exhibited 71 and 67% antioxidant activity in DPPH and hydroxyl radical scavenging model systems, respectively. Similarly, the extract also showed 72, 71, and 70% antioxidant activity in the liver, brain, and kidney of rats. Low-density lipoprotein oxidation induced by Cu2+ ions was also protected (22, 38, and 51%) by the algal extract in a dose-dependent manner (4, 6, and 8 ppm levels of total carotenoid). Thiobarbituric acid reactive substances concentration in the blood, liver, and kidney of rats was also significantly decreased in B. braunii treated samples compared with those of control. Carotenoids (violaxanthin, astaxanthin, lutein, zeaxanthin, chlorophylls a and b, and alpha, beta-carotene) identified in the B. braunii acetone extract may be exhibiting antioxidant activity. Among the carotenoids, lutein represents more than 75% of the total carotenoids. B. braunii extract was shown to be effective for protecting biological systems against various oxidative stresses in vitro. This is the first report on the antioxidant properties of B. braunii. PMID:16787003

Rao, Ambati Ranga; Sarada, Ravi; Baskaran, Vallikannan; Ravishankar, Gokare Aswathanarayana

2006-06-28

15

Culture of the green microalga Botryococcus braunii Showa with LED irradiation eliminating violet light enhances hydrocarbon production and recovery.  

PubMed

The green microalga Botryococcus braunii (B. braunii), race B, was cultured under light-emitting diode (LED) irradiation with and without violet light. This study examined the effect of violet light on hydrocarbon recovery and production in B. braunii. C34 botryococcene hydrocarbons were efficiently extracted by thermal pretreatments at lower temperatures when the alga was cultured without violet light. The hydrocarbon content was also higher (approximately 3%) in samples cultured without violet light. To elucidate the mechanism of effective hydrocarbon recovery and production, we examined structural components of the extracellular matrix (ECM). The amounts of extracellular carotenoids and water-soluble polymers extracted by thermal pretreatment from the ECM were decreased when the alga was cultured without violet light. These results indicate that LED irradiation without violet light is more effective for hydrocarbon recovery and production in B. braunii. Furthermore, structural ECM components are closely involved in hydrocarbon recovery and production in B. braunii. PMID:25069809

Atobe, Sueko; Saga, Kiyotaka; Maeyama, Haruko; Fujiwara, Kazuhiro; Okada, Shigeru; Imou, Kenji

2014-10-01

16

Interactions of Botryococcus braunii Cultures with Bacterial Biofilms  

Microsoft Academic Search

Unicellular microalgae generally grow in the presence of bacteria, particularly when they are farmed massively. This study\\u000a 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\\u000a (?107–108 culturable cells per gram microalgae). Furthermore, we identified the culturable bacteria forming

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

2010-01-01

17

Identification of unique mechanisms for triterpene biosynthesis in Botryococcus braunii  

PubMed Central

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 500 MYA. 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

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

2011-01-01

18

Hydrocarbon production in high density Botryococcus braunii race B continuous culture.  

PubMed

Continuous cultures of Botryococcus braunii race B were maintained at photosynthetic cell densities as high as 20 g dry weight per liter for up to 3 months. Growth associated triterpene hydrocarbon accumulation was nearly constant at 22.5% of dry weight for a range of growth rates maintained by daily replacement of 5-15% of the respective cultures. The ability to achieve high cell concentrations and oil levels of roughly 5 g triterpene oil/L resulted from a combination of high light (? 1/4 full sun for 15 h/day) and replenishing stoichiometrically balanced growth medium. Due to light-limited growth conditions, cell concentration dropped nearly linearly with increased dilution rate. This reduction in cell number resulted in increased productivity per cell at higher dilution rates and was accompanied by a dramatic increase in algae colony size from 0.09 to 0.343 mm at high dilution rate. This change in colony size resulted in an equally dramatic change in optical density (OD) per gram dry weight, which precluded use of simple correlations of OD and cell concentration. A trickle-film photobioreactor was also demonstrated as a scalable approach to achieving these ultra-high cell concentrations. Additional media analysis revealed a steady increase in photobioreactor conductivity suggesting an accumulation of ions may be the reason for rapid culture crash and washout observed at all dilution rates after several months of continuous operation. The volumetric productivity of 22.5 mg oil/L/photo-h reported here is more than an order of magnitude higher than previous reports for B. braunii race B, reflecting the high cell densities used in this work and substantiating a higher metabolic rate for B. braunii race B than previously surmised from its relatively long doubling times. PMID:24122424

Khatri, Waqas; Hendrix, Robert; Niehaus, Tom; Chappell, Joe; Curtis, Wayne R

2014-03-01

19

Effect of media and culture conditions on growth and hydrocarbon production by Botryococcus braunii  

Microsoft Academic Search

The influence of the media constituents potassium nitrate, magnesium sulphate, dihydrogen potassium phosphate and ferric citrate on growth and hydrocarbon production in Botryococcus braunii (SAG 30.81) was investigated using response surface methodology (RSM). Among the individual variables, potassium nitrate and ferric citrate exhibited marked effects on the response functions (yield of biomass and hydrocarbon production). A high correlation coefficient (r?0.93,

C. Dayananda; R. Sarada; Sila Bhattacharya; G. A. Ravishankar

2005-01-01

20

High biofuel production of Botryococcus braunii using optimized cultivation strategies  

E-print Network

and algae biomass increases rapidly as well as the biofuelbiofuel obtained from microalgae right now, scientists are searching for other valuable products from algaeand biofuel productivity. Currently all the culture media use a single source of nitrogen to feed algae,

Yu, Wei

2014-01-01

21

Author's personal copy Radiation characteristics of Botryococcus braunii,  

E-print Network

, and Chlorella sp. used for CO2 fixation and biofuel production Halil Berberoglu a , Pedro S. Gomez b , Laurent t This paper reports experimental measurements of the radiation characteristics of green algae used for carbon dioxide fixation via photosynthesis. The generated biomass can be used to produce not only biofuels

Pilon, Laurent

22

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

PubMed

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 5°C and above 35°C 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 30°C 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

Yoshimura, Takeshi; Okada, Shigeru; Honda, Masaki

2013-04-01

23

Thermal decomposition process in algaenan of Botryococcus braunii race L. Part 2: Molecular dynamics simulations using the ReaxFF reactive force field  

Microsoft Academic Search

This paper reports ReaxFF MD simulation results on pyrolysis of a molecular model of the algaenan Botryococcus braunii race L biopolymer, specifically, ReaxFF predictions on the pyrolysis of prototypical chemical structures involving aliphatic chain esters and aldehydes. These preliminary computational experiments are then used to analyze the thermal cracking process within algaenan race L biopolymers. The simulations indicate that the

Elodie Salmon; Adri C. T. van Duin; François Lorant; Paul-Marie Marquaire; William A. Goddard III

2009-01-01

24

Hydrogen isotope fractionation in freshwater algae: I. Variations among lipids and species  

E-print Network

Hydrogen isotope fractionation in freshwater algae: I. Variations among lipids and species Zhaohui Abstract Five species of freshwater green algae, including three strains of Botryococcus braunii (two in the algae, including alkadienes, botryococcenes, heptadecenes, fatty acids, and phytadiene, were measured

Sachs, Julian P.

25

Modes of hydrocarbon oil biosynthesis revealed by comparative gene expression analysis for race A and race B strains of Botryococcus braunii.  

PubMed

To clarify the oil biosynthetic routes of the oil-producing green alga Botryococcus braunii, here the race-specific gene expression patterns were examined using representative strains of race A and race B producing fatty acid- and triterpene-derived hydrocarbon oils, respectively. The strain-specific gene expression patterns in the BOT-88-2 strain (race A) and the BOT-22 strain (race B) were revealed by transcriptome comparison and real-time PCR quantification. For race A, it was inferred from the gene expression patterns that the fatty acid elongation in the acyl-carrier-protein (acp)-bound form followed by further elongation in the coenzyme A (CoA)-bound form is the major route of oil biosynthesis. The fatty acids may be desaturated in both acp- and CoA-bound forms and once metabolized into glycerolipids prior to further elongation. For race B, relatively direct entry of photosynthetic products from the reductive pentose phosphate cycle into the mevalonate-independent triterpene biosynthesis was implicated. PMID:22257857

Ioki, Motohide; Baba, Masato; Bidadi, Haniyeh; Suzuki, Iwane; Shiraiwa, Yoshihiro; Watanabe, Makoto M; Nakajima, Nobuyoshi

2012-04-01

26

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

PubMed

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

Yeesang, Chittra; Cheirsilp, Benjamas

2014-09-01

27

Pilon's Lab UCLA www.seas.ucla.edu/~pilon/ Refraction and absorption index of Botryococcus braunii, Chlorella sp. and  

E-print Network

braunii, Chlorella sp. and Chlorococcum littorale Source: Euntaek Lee, Ri-Liang Heng, Laurent Pilon,n Wavelength, (nm) B. braunii Chlorella sp. C. littorale 400 450 500 550 600 650 700 750 0.0000 0.0005 0.seas.ucla.edu/~pilon/ Refraction and absorption index of Chlorella sp. 6 7 8 9 10 11 12 13 14 15 16 0.000 0.005 0.010 0.015 0.020 0

Pilon, Laurent

28

Reclaimed Water and Secondary Wastewater as Alternative Growing Media for Green Algae for Biofuel Production  

Microsoft Academic Search

The microalga Botryococcus braunii is one of many photosynthtic algae species being investigated as renewable feedstocks for production of biofuels. One key advantage of algae as biofuel feedstock, in view of the growing scarcity of fresh water worldwide, is the potential of algae to grow in low-quality water, including in the nutrient-containing effluents from wastewater-treatment plants. Indeed, algae could also

Sara S. Kuwahara; Joel L. Cuello

29

Effect of glutamine on glutamine-synthetase regulation in the green alga Monoraphidium braunii  

Microsoft Academic Search

Glutamine-synthetase (GS; EC 6.3.1.2) activity and protein levels were measured in crude extracts from Monoraphidium braunii Näegeli, strain 202-7d, cultures grown under different nitrogen sources. Only ammonium and l-glutamine promoted a partial enzyme inactivation, which, in the case of l-glutamine, was accompanied by a significant repression of GS. Methionine sulfoximine (MSX), a strong inhibitor of GS, produced a drastic inactivation

José Manuel Garcia-Fernández; Antonio López-Ruiz; José Alhama; José Manuel Roldán; Jesús Diez Dapena

1995-01-01

30

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

SciTech Connect

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.

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

2011-01-01

31

Algae.  

PubMed

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

Raven, John A; Giordano, Mario

2014-07-01

32

Revised version Organic Geochemistry 22, 1023-1027, 1994.  

E-print Network

. Abstract- A Pliocene oil shale (Pula, Hungary), a C3 plant Triticum aestivum and a C4 plant Zea mays were-alkane, n-alkene, Pula oil shale, Botryococcus braunii, alga, plant, waxes, sediment. INTRODUCTION n-rich, Pliocene deposit from Pula (Hungary). The bulk carbon isotope ratio of this oil shale was also determined

33

Botryococcene - A tetramethylated acyclic triterpenoid of algal origin  

NASA Technical Reports Server (NTRS)

The green alga Botryococcus braunii, implicated in the formation of certain geological deposits, produces unusual isomeric C34H58 alkenes, botryococcene and isobotryococcene, during a particular physiological state. A structure for botryococcene is suggested, taking into account NMR techniques, oxidative degradation, and established biosynthetic principles. Botryococcene appears terpenoid in origin.

Cox, R. E.; Burlingame, A. L.; Wilson, D. M.; Eglinton, G.; Maxwell, J. R.

1973-01-01

34

Thermal decomposition process in algaenan of Botryococcus braunii race L. Part 2: Molecular dynamics simulations using the ReaxFF reactive force field  

E-print Network

dynamics simulations using the ReaxFF reactive force field Elodie Salmon a , Adri C.T. van Duin b Accepted 27 August 2008 Available online 17 October 2008 a b s t r a c t This paper reports ReaxFF MD, specifically, ReaxFF predictions on the pyrolysis of prototypical chemical structures involving aliphatic chain

Goddard III, William A.

35

Heterotrimeric G-proteins in green algae  

PubMed Central

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

Hackenberg, Dieter; Pandey, Sona

2014-01-01

36

The Study of Algae  

ERIC Educational Resources Information Center

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)

Rushforth, Samuel R.

1977-01-01

37

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

USGS Publications Warehouse

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.

Mastalerz, M.; Hower, J.C.

1996-01-01

38

Green Algae  

NSDL National Science Digital Library

Color photomicrographs of several species of green algae with brief descriptions of their chief characteristics and habitat. Scroll to the bottom of the page to links to bacteria, and more protists including diatoms, desmids and rotifers.

Van Egmond, Wim

2010-01-01

39

BROWN ALGAE Colpomenia sinuosa  

E-print Network

BROWN ALGAE Colpomenia sinuosa GREEN ALGAE Dictyosphaeria cavernosa Amphiroa fragilissima Gelidiopsis intricata Botryocladia pyriformis RED ALGAE CYANOBACTERIA Oscillitoria acuminata Schizothrix sp. "ALGAE"­ A DIVERSE ASSORTMENT OF LIFE FORMS Photosynthesis is performed by a taxonomically diverse

Sullivan, Matthew B.

40

Algae Biodiesel: Commercialization  

E-print Network

and Materials (ASTM) standards for biodiesel (ASTM 6751) #12;Reasons for Algae Biofuel Development in New MexicoAlgae Biodiesel: A Path to Commercialization Algae Biodiesel: A Path to Commercialization Center conservation and biomonitoring · Algae biodiesel is largest CEHMM project #12;Project Overview: The Missing

Tullos, Desiree

41

Biogeography of Marine Algae  

E-print Network

Biogeography of Marine Algae David J Garbary, St Francis Xavier University, Antigonish, Nova Scotia and vicariance in establishing distributions and as factors associated with speciation. Since eukaryotic algae. There are many species that are virtually cosmopolitan (e.g. the green alga Enteromorpha intestinalis, the red

42

Granulados bioclásticos: algas calcárias  

Microsoft Academic Search

Os granulados bioclásticos marinhos, no Brasil, são formados principalmente por algas calcárias (Maerl e Lithothamnium, na França). Apenas as formas livres (free-living) das algas calcárias, tais como rodolitos, nódulos, e seus fragmentos, são viáveis para a exploração econômica, pois constituem depósitos sedimentares inconsolidados, facilmente coletados através de dragagens. As algas calcárias são compostas basicamente por carbonato de cálcio e carbonato

Gilberto T. M. Dias

2000-01-01

43

Green-Algae  

E-print Network

Chloroplasts evolved through multiple endosymbioses Endosymbiosis has been a fundamental process in evolution, giving rise to cell organelles including chloroplasts (the center for photosynthesis in plants and algae). Primary chloroplasts in green algae and land plants resulted from an ancient endosymbiotic association with photosynthetic bacteria. Subsequent secondary endosymbioses spread chloroplasts of green and red algae across the tree of life (Fig. 1) [1]. Some algae have undergone even more recent, tertiary endosymbioses, while others contain klepto-chloroplasts (temporary chloroplasts acquired from prey) [2]. The algae Dinophysis has klepto-chloroplasts stolen from photosynthetic prey

Jennifer H. Wisecaver

44

Alkaloids in marine algae  

E-print Network

Abstract: 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.

Kas?m Cemal Güven; Aline Percot; Ekrem Sezik

45

Loliolide in marine algae  

Microsoft Academic Search

Loliolide content was determined in 13 marine algae including red, brown and green algae collected from the Black Sea, the Dardanelles and the Aegean Sea. Identification and quantification were performed by gas chromatography-mass spectrometry. The loliolide content in green alga is 1.76 µg g, ranges from 0.14 to 4.35 µg g in red and from 0.18 to 4.83 µg g

Aline Percot; Ahmet Yalç?n; Veysel Aysel; Hüseyin Erdu?an; Berrin Dural; Kas?m Cemal Güven

2009-01-01

46

Photosynthesis in Symbiotic Algae  

Microsoft Academic Search

\\u000a Symbiosis is an evolutionary strategy that often confers an ecological advantage on the partners. Algae exist in symbiosis\\u000a with a number of hosts and in a range of different anatomical relationships including exosymbiosis (lichens) and endosymbiosis\\u000a (corals). Each of these imposes on the alga a chemical environment significantly different from that of free-living algae\\u000a and this impacts on algal photosynthesis.

David Yellowlees; Mark Warner

47

AlgaeBase  

NSDL National Science Digital Library

AlgaeBase offers a free database of information on algae species around the world. This project is part of the Species 2000 initiative, created to enumerate "all known species of plants, animals, fungi and microbes on Earth as the baseline dataset for studies of global biodiversity." User may search the database for literature citations and photographs for algae identified by genus, species, or common name. The photographs, mostly of Irish species, are well referenced and often quite beautiful. Currently the seaweed data are most complete, but additional data are frequently added. Both the Web site and the database are straightforward and easy to use.

Dhonncha, Eilis N.; Guiry, Michael D.

48

Antitumor activity of marine algae  

Microsoft Academic Search

Powdered tissue from 46 species of air-dried marine algae (four green, 21 brown and 21 red algae) were screened for antitumor activity. Significant activity against Ehrlich carcinoma was found in the brown algae Scytosiphon lomentaria (69.8% inhibition), Lessonia nigrescens (60.0%), Laminaria japonica (57.6%), Sargassum ringgoldianum (46.5%), the red algae Porphyra yezoensis (53.2%) and Eucheuma gelatinae (52.1%) and the green alga

Hiroyuki Noda; Hideomi Amano; Koichi Arashima; Kazutosi Nisizawa

1990-01-01

49

Grow Your Own Algae!  

NSDL National Science Digital Library

Students discover how tiny microscopic plants can remove nutrients from polluted water. They also learn how to engineer a system to remove pollutants faster and faster by changing the environment for the algae.

STARS GK-12 Program,

50

Algae in water supplies  

Microsoft Academic Search

An extensive taxonomic key to the algae found in fresh water supplies is presented. In addition to the keys, color plates of the common species are included to facilitate microscopic identification. 136 references, 56 figures, 13 tables.

1962-01-01

51

Algae Harvest Energy Conversion  

Microsoft Academic Search

\\u000a Algae harvest energy conversion to biofuel technology is a promising alternative to fossil fuel that has inherent pollution\\u000a attachment. With present resources available for the microalgae mass production and hence, high oil yield, microalgal can\\u000a sufficiently be a new source of renewable energy to replace the fossil fuels. In this chapter, algae description, composition,\\u000a cultivation, its conversion to biofuel, and

Yung-Tse Hung; O. Sarafadeen Amuda; A. Olanrewaju Alade; I. Adekunle Amoo; Stephen Tiong-Lee Tay; Kathleen Hung Li

52

The Harmful Algae Page  

NSDL National Science Digital Library

Relevant sections in this resource include What are Harmful Algal Blooms (HABs), an Introduction to Algal Blooms and "Red Tide", Algae Species (which algae are responsible for the harmful effects?), Adverse Impacts, Human Illness (food poisoning associated with harmful algal blooms & information on diagnosis and treatment), HAB Distribution Maps, HAB events in the United States and around the world, HAB related articles as printed in the news media, and a photo gallery of visible algal blooms, photomicrographs, and satellite imagery.

Anderson, Donald

2004-06-17

53

Supercritical carbon dioxide extraction of compounds with pharmaceutical importance from microalgae  

Microsoft Academic Search

Four microalgae (Botryococcus braunii, Chlorella vulgaris, Dunaliella salina, Arthrospira maxima) were object of supercritical CO2 extraction studies, which were carried out in a flow apparatus at temperatures between 313.1 and 333.1 K and pressures up to 35.0 MPa. The microalga Botryococcus braunii produces extracellular alkadienes. Supercritical extracts obtained at 313.1 K, and pressures of 12.5, 20.0 and 30.0 MPa, were

Rui L. Mendes; Beatriz P. Nobre; Miguel T. Cardoso; Ana P. Pereira; António F. Palavra

2003-01-01

54

The Great Algae Race  

NSDL National Science Digital Library

In a multi-week experiment, student groups gather data from the photobioreactors that they build to investigate growth conditions that make algae thrive best. Using plastic soda bottles, pond water and fish tank aerators, they vary the amount of carbon dioxide (or nutrients or sunlight, as an extension) available to the microalgae. They compare growth in aerated vs. non-aerated conditions. They measure growth by comparing the color of their algae cultures in the bottles to a color indicator scale. Then they graph and analyze the collected data to see which had the fastest growth. Students learn how plants biorecycle carbon dioxide into organic carbon (part of the carbon cycle) and how engineers apply their understanding of this process to maximize biofuel production.

Membrane Biotechnology Laboratory

55

Arsoniumphospholipid in Algae  

Microsoft Academic Search

A novel phospholipid containing arsenic was formed by all marine algae cultured in [74As]arsenate. Components of the labeled algal extracts readily separated by two-dimensional paper radiochromatography. Base-catalyzed deacylation of the major lipid yielded a phosphodiester identical to one of the two major water-soluble compounds. Acid or enzymic hydrolysis of the phosphodiester produced a product identified as trimethylarsoniumlactic acid. The structure

Robert V. Cooney; R. O. Mumma; A. A. Benson

1978-01-01

56

Sustainable biofuels from algae  

Microsoft Academic Search

There is currently great interest in microalgae as sources of renewable energy and biofuels. Many algae species have a high\\u000a lipid content and can be grown on non-arable land using alternate water sources such as seawater. This paper discusses in\\u000a detail the issue of sustainability of commercial-scale microalgae production of biofuels with particular focus on land, water,\\u000a nutrients (N and

Michael Armin Borowitzka; Navid Reza Moheimani

57

Hydrogen evolution by several algae  

Microsoft Academic Search

Out of 33 strains of unicellular algae examined, H2 evolution was observed only in species of Chlamydomonas, Chlorella and Scenedesmus. While the photoevolution of H2 by these algae was generally stimulated both by an organic substrate and by the uncoupler CCCP1, response to DCMU varied. On the basis of the response to DCMU, it was concluded that the mechanism of

F. P. Healey

1970-01-01

58

The Harmful Algae Page  

NSDL National Science Digital Library

Produced by the National Office of Marine Biotoxins and Harmful Algal Blooms and housed at the Woods Hole Oceanographic Institution, this site covers the dark side of the organisms that provide the foundation for almost all marine life. The site focuses on the small number of algae that produce potent neurotoxins that "can be transferred through the food web where they affect and even kill the higher forms of life such as zooplankton, shellfish, fish, birds, marine mammals, and even humans that feed either directly or indirectly on them." The site is divided into the following sections: photos of "Red Tide" blooms, species responsible for harmful effects, adverse impacts at higher trophic levels, human illness associated with algal blooms, and effects in your region. Researchers, educators, and people with interests in such recent headline topics such as the Pfiesteria scare can all find useful information at this site.

., Woods H.

1997-01-01

59

Fuel From Algae: Scaling and Commercialization of Algae Harvesting Technologies  

SciTech Connect

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.

None

2010-01-15

60

Testing for Toxic Algae By Tadd Barrow  

E-print Network

Testing for Toxic Algae By Tadd Barrow UNL Extension Educator, Water Quality Algae is a microscopic plant that occurs in all water. However, only certain conditions bring algae to the surface, making it toxic to animals, especially humans and dogs. Toxic algae often are naturally occurring from high

Nebraska-Lincoln, University of

61

Algae fuel clean electricity generation  

SciTech Connect

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.

O'Sullivan, D.

1993-02-08

62

F-LE Algae Blooms  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Algae blooms routinely threaten the health of the Chesapeake Bay. Phosphate compounds supply a rich source of nutrients for the algae, Prorocentrum min...

63

Neuroprotective effects of marine algae.  

PubMed

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

Pangestuti, Ratih; Kim, Se-Kwon

2011-01-01

64

Neuroprotective Effects of Marine Algae  

PubMed Central

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

Pangestuti, Ratih; Kim, Se-Kwon

2011-01-01

65

Energy 101: Algae-to-fuels  

NSDL National Science Digital Library

This video is from the Energy 101 video series. It explains the process for converting micro-algae into fuel and makes the case that algae-based biofuels hold enormous potential for helping reduce our dependence on imported oil.

Pierce, Erin R.; Energy, U. S.

66

Course Syllabus MARINE ALGAE (Biol 533)  

E-print Network

will include introduction to selected analytical gear (e.g., dissolved oxygen metersCourse Syllabus MARINE ALGAE (Biol 533) Dr. Thomas F. Mumford Dr. J the biodiversity of marine algae with emphasis on their role in marine ecosystems

Carrington, Emily

67

School of Engineering and Science Algae Biofuels  

E-print Network

School of Engineering and Science Algae Biofuels BY: Alessandro Faldi, Ph.D. Section Head is algae- based biofuels, which we believe could be a meaningful part of the energy mix in the future. Algae biofuels have potential to be an economically viable, low-net carbon transportation fuel

Fisher, Frank

68

Notes from the Iberian Algae Belt  

Microsoft Academic Search

In this paper, we explore regional innovation in the use of varieties of algae as inputs to industrial processes. It is important to understand that algae are one of nature's most bountiful products, with an almost infinite variety of applications. Algae have received prominence in the research literature because of the strong evidence that they can make a major contribution

Philip Cooke; Julie Porter; Hugo Pinto; Ana Rita Cruz; Fangzhu Zhang

2011-01-01

69

Reduced models of algae growth Heikki Haario,  

E-print Network

Reduced models of algae growth Heikki Haario, Leonid Kalachev Marko Laine, Lappeenranta University of the phenomena studied. Here, in the case of algae growth modelling, we show how a systematic model reduction may: Algae growth modelling, asymptotic methods, model reduction, MCMC, Adaptive Markov chain Monte Carlo. 1

Bardsley, John

70

Algae -- a poor man's HAART?  

PubMed

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

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

2004-01-01

71

Allelopathy of filamentous green algae  

Microsoft Academic Search

Allelopathy of filamentous green algae (FGA) has been less studied than that of macrophytes. Little Budworth Pool, Cheshire, UK is a small, shallow, clear-water lake with high TP concentrations, very high NO3-N concentrations, only moderate phytoplankton density, high FGA growth (mainly Spirogyra sp.) and no submerged plants. Experiments were carried out to test the possible allelopathic effects of Spirogyra on

Brian Moss

2005-01-01

72

Algae. LC Science Tracer Bullet.  

ERIC Educational Resources Information Center

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…

Niskern, Diana, Comp.

73

Introduction to the Green Algae  

NSDL National Science Digital Library

This interesting site on "Green Algae" (a paraphyletic group excluding Plantae) is maintained by the University of California's Museum of Paleontology, and is a central resource for algal information with links to associated resources. Four sections make up the heart of the site: Fossil Record, Life History & Ecology, Systematics, and More on Morphology. Additionally, this well-designed site contains many links to illustrated definitions and additional facts.

Speer, Brian R.

1998-01-01

74

Parasites in algae mass culture  

PubMed Central

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

Carney, Laura T.; Lane, Todd W.

2014-01-01

75

Halogenated compounds from marine algae.  

PubMed

Marine algae produce a cocktail of halogenated metabolites with potential commercial value. Structures exhibited by these compounds go from acyclic entities with a linear chain to complex polycyclic molecules. Their medical and pharmaceutical application has been investigated for a few decades, however other properties, such as antifouling, are not to be discarded. Many compounds were discovered in the last years, although the need for new drugs keeps this field open as many algal species are poorly screened. The ecological role of marine algal halogenated metabolites has somehow been overlooked. This new research field will provide valuable and novel insight into the marine ecosystem dynamics as well as a new approach to comprehending biodiversity. Furthermore, understanding interactions between halogenated compound production by algae and the environment, including anthropogenic or global climate changes, is a challenging target for the coming years. Research of halogenated metabolites has been more focused on macroalgae than on phytoplankton. However, phytoplankton could be a very promising material since it is the base of the marine food chain with quick adaptation to environmental changes, which undoubtedly has consequences on secondary metabolism. This paper reviews recent progress on this field and presents trends on the role of marine algae as producers of halogenated compounds. PMID:20948909

Cabrita, Maria Teresa; Vale, Carlos; Rauter, Amélia Pilar

2010-01-01

76

Parasites in algae mass culture.  

PubMed

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

Carney, Laura T; Lane, Todd W

2014-01-01

77

Importance of algae oil as a source of biodiesel  

Microsoft Academic Search

Algae are the fastest-growing plants in the world. Industrial reactors for algal culture are open ponds, photobioreactors and closed systems. Algae are very important as a biomass source. Algae will some day be competitive as a source for biofuel. Different species of algae may be better suited for different types of fuel. Algae can be grown almost anywhere, even on

Ayhan Demirbas; M. Fatih Demirbas

2011-01-01

78

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

PubMed

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

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

2013-03-01

79

Stochastic Forecasting of Algae Blooms in Lakes  

SciTech Connect

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.

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

2013-01-15

80

The systematics and ecology of soil algae  

Microsoft Academic Search

Summary  Algae occur in nearly all terrestrial environments on earth and are invariably encountered both on and beneath soil surfaces.\\u000a The algal flora of the soil includes members of the Cyanochloronta, Chlorophycophyta, Euglenophycophyta, Chrysophycophyta,\\u000a and Rhodophycophyta. Thirty-eight genera of prokaryotic and 147 genera of eukaryotic algae include terrestrial species, the\\u000a majority of which are edaphic. Whereas systematic nomenclature of blue-green algae

Blaine Metting

1981-01-01

81

Hydrocarbon feedstocks from algae hydrogenation  

SciTech Connect

A hydrogenation process for converting algae (Chlorella pyrenoidosa) to liquid products was developed. The hydrogenation was carried out in a batch autoclave at temperatures between 340 and 430 K and hydrogen pressures between 1 and 150 atm in the presence of a catalyst and a solvent. Yields of up to 50% oil in the C/sub 16/-C/sub 24/ range resulted, and by-products of ammonium carbonate and hydrocarbon gases were obtained. A kinetic model fitting the data quite well indicated that an asphaltenic substance was a reaction intermediate under all processing conditions.

Chin, L.Y.; Engel, A.J.

1981-01-01

82

A golden opportunity: Researchers making progress in understanding toxic algae  

E-print Network

tx H2O | pg. 20 cientists at three Texas universities investigating golden algae, its explosive growth, and its deadly toxins have dis- covered an apparent competition between golden algae and blue green algae in certain Texas lakes... chemical warfare between golden algae and blue green algae. Only when golden algae wins this chemical warfare is it able to bloom.? Roelke, along with Dr. Bryan Brooks of Baylor University and Dr. James Grover of the University of Texas at Arlington...

Wythe, Kathy

2008-01-01

83

SSMILes: Measuring the Nutrient Tolerance of Algae.  

ERIC Educational Resources Information Center

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)

Hedgepeth, David J.

1995-01-01

84

RESEARCH ARTICLE Algae production on pig sludge  

E-print Network

-011-0077-2 #12;mainly because of the growing role of algae in biofuel production and RESEARCH ARTICLE Algae production on pig sludge Attila Bai & László Stündl & Péter Bársony & Milán pollution. This issue may be solved by using pig sludge for algal biofuel production. Therefore, we stud

Boyer, Edmond

85

Use of algae as biofuel sources  

Microsoft Academic Search

The aim of this study is to investigate the algae production technologies such as open, closed and hybrid systems, production costs, and algal energy conversions. Liquid biofuels are alternative fuels promoted with potential to reduce dependence on fossil fuel imports. Biofuels production costs can vary widely by feedstock, conversion process, scale of production and region. Algae will become the most

Ayhan Demirbas

2010-01-01

86

ALGAE REMOVAL BY THE OVERLAND FLOW PROCESS  

EPA Science Inventory

Control of algae production will be necessary when lagoons are utilized as a preapplication treatment process for overland flow. The overland flow process has a surface discharge and must meet secondary treatment limitations to be viable. Brief summaries of other algae removal in...

87

FACTORS INFLUENCING METAL ACCUMULATION BY ALGAE  

EPA Science Inventory

Shallow beds of algae (algal meanders) have proved to be highly effective at removing heavy metals and organometallics from lead-zinc mine and mill wastes. A research program was initiated (1) to determine conditions under which algae were most effective at concentrating signific...

88

Take a Dip! Culturing Algae Is Easy.  

ERIC Educational Resources Information Center

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.…

James, Daniel E.

1983-01-01

89

Flocculation of model algae under shear.  

SciTech Connect

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.

Pierce, Flint; Lechman, Jeremy B.

2010-11-01

90

Composting of waste algae: a review.  

PubMed

Although composting has been successfully used at pilot scale to manage waste algae removed from eutrophied water environments and the compost product applied as a fertiliser, clear guidelines are not available for full scale algae composting. The review reports on the application of composting to stabilize waste algae, which to date has mainly been macro-algae, and identifies the peculiarities of algae as a composting feedstock, these being: relatively low carbon to nitrogen (C/N) ratio, which can result in nitrogen loss as NH3 and even N2O; high moisture content and low porosity, which together make aeration challenging; potentially high salinity, which can have adverse consequence for composting; and potentially have high metals and toxin content, which can affect application of the product as a fertiliser. To overcome the challenges that these peculiarities impose co-compost materials can be employed. PMID:24602833

Han, Wei; Clarke, William; Pratt, Steven

2014-07-01

91

The ice nucleation activity of extremophilic algae.  

PubMed

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

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

2013-01-01

92

Algae biodiesel - a feasibility report  

PubMed Central

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

2012-01-01

93

21 CFR 73.275 - Dried algae meal.  

...2014-04-01 2014-04-01 false Dried algae meal. 73.275 Section 73.275 Food...CERTIFICATION Foods § 73.275 Dried algae meal. (a) Identity. The color additive dried algae meal is a dried mixture of algae...

2014-04-01

94

21 CFR 73.275 - Dried algae meal.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Dried algae meal. 73.275 Section 73.275 Food...CERTIFICATION Foods § 73.275 Dried algae meal. (a) Identity. The color additive dried algae meal is a dried mixture of algae...

2013-04-01

95

21 CFR 73.275 - Dried algae meal.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Dried algae meal. 73.275 Section 73.275 Food...CERTIFICATION Foods § 73.275 Dried algae meal. (a) Identity. The color additive dried algae meal is a dried mixture of algae...

2012-04-01

96

21 CFR 73.275 - Dried algae meal.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Dried algae meal. 73.275 Section 73.275 Food...CERTIFICATION Foods § 73.275 Dried algae meal. (a) Identity. The color additive dried algae meal is a dried mixture of algae...

2011-04-01

97

21 CFR 73.275 - Dried algae meal.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Dried algae meal. 73.275 Section 73.275 Food...CERTIFICATION Foods § 73.275 Dried algae meal. (a) Identity. The color additive dried algae meal is a dried mixture of algae...

2010-04-01

98

Analysis of Land Suitable for Algae State of Hawaii  

E-print Network

of Hawaii at Manoa August 2011 #12;i Executive Summary Algae are considered to be a viable crop for biofuel for biofuels has increased interest in growing algae in Hawaii for biofuels. An analysis of algae productionAnalysis of Land Suitable for Algae Production State of Hawaii Prepared by Mele Chillingworth Scott

99

Supercritical carbon dioxide extraction of bioactive compounds from microalgae and volatile oils from aromatic plants  

Microsoft Academic Search

A discussion of the most interesting results obtained in our laboratories, during the supercritical CO2 extraction of bioactive compounds from microalgae and volatile oils from aromatic plants, was carried out. Concerning the microalgae, the studies on Botryococcus braunii and Chlorella vulgaris were selected. Hydrocarbons from the first microalgae, which are mainly linear alkadienes (C23–C31) with an odd number of carbon

A. M. F. Palavra; J. P. Coelho; J. G. Barroso; A. P. Rauter; J. M. N. A. Fareleira; A. Mainar; J. S. Urieta; B. P. Nobre; L. Gouveia; R. L. Mendes; J. M. S. Cabral; J. M. Novais

100

Possibility of renewable energy production and CO 2 mitigation by thermochemical liquefaction of microalgae  

Microsoft Academic Search

The energy balance and CO2 mitigating effect of a liquid fuel production process from microalgae using thermochemical liquefaction were studied. Thermochemical liquefaction has the advantage of treating wet materials compared with direct combustion, gasification and pyrolysis, because it does not require a drying process. The yield of liquid fuel produced from Botryococcus braunii and its lower heating value were high

S Sawayama; T Minowa; S-Y Yokoyama

1999-01-01

101

Collection, Isolation and Culture of Marine Algae.  

ERIC Educational Resources Information Center

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)

James, Daniel E.

1984-01-01

102

The Study of Development Using Red Algae  

NSDL National Science Digital Library

This exercise can be used to demonstrate developmental processes at the cellular level, environmental control of photosynthesis, and cell enlargement by using red algae, which is well-suited for these types of experiments.

Susan D. Waaland (University of Washington;)

1982-06-21

103

Phylloplane algae of standing dead Spartina alterniflora  

Microsoft Academic Search

Phylloplane (leaf surface) algae on leaves from standing dead Spartina alterniflora Loisel in Sapelo Island marshes were enumerated by epifluorescence microscopy. The green alga Pseudendoclonium submarinum Wille dominated algal biovolume on both short-and tall-form plants during summer and winter. Intra-leaf and intra-plant patterns of algal biovolume and diversity indicated that desiccation stress may be an important selective factor. Observed epiphyte

R. D. Fallon; S. Y. Newell; L. C. Groene

1985-01-01

104

Antioxidant activity of Hawaiian marine algae.  

PubMed

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

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

2012-02-01

105

Antioxidant Activity of Hawaiian Marine Algae  

PubMed Central

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

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

2012-01-01

106

Carotenoids in Algae: Distributions, Biosyntheses and Functions  

PubMed Central

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 b6f 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

Takaichi, Shinichi

2011-01-01

107

Systems and economic analysis of microalgae ponds for conversion of CO{sub 2} to biomass. Fourth quarterly technical progress report, June 16, 1994--September 15, 1994  

SciTech Connect

The threat of global warming, mounting concerns about air and water pollution, prospective food shortages, and declining reserves of low-cost fossil fuels, have spawned a burgeoning interest in photobiological processes using microalgae as a method of large-scale utilization of CO{sub 2} for the production of fuels, food, and waste treatment. The major activity during this quarter was the development of cost data for the algal production system, including alternatives to the basic design previously used. The results of this work are still being developed and will be reported in the Final Report. This progress report summarizes a study of a production processes for one specific alga, Botryococcus braunii. This alga is of particular interest in this project as it produces an almost pure hydrocarbon fuel, and does so in rather large amounts. Technology for the production of this organism has, however, not yet been developed. This progress report reviews the literature on this interesting alga and suggests potential methods for its production. 62 refs.

Benemann, J.R.; Oswald, W.J.

1994-12-28

108

SCALE FORMATION IN CHRYSOPHYCEAN ALGAE  

PubMed Central

The cell wall of the marine chrysophycean alga Pleurochrysis scherfellii is composed of distinct wall fragments embedded in a gelatinous mass. The latter is a polysaccharide of pectic character which is rich in galactose and ribose. These wall fragments are identified as scales. They have been isolated and purified from the vegetative mother cell walls after zoospore formation. Their ultrastructure is described in an electron microscope study combining sectioning, freeze-etch, and negative staining techniques. The scales consist of a layer of concentrically arranged microfibrils (ribbons with cross-sections of 12 to 25 x 25 to 40 A) and underlying radial fibrils of similar dimensions. Such a network-plate is densely coated with particles which are assumed to be identical to the pectic component. The microfibrils are resistant to strong alkaline treatment and have been identified as cellulose by different methods, including sugar analysis after total hydrolysis, proton resonance spectroscopical examination (NMR spectroscopy) of the benzoylated product, and diverse histochemical tests. The formation and secretion of the scales can be followed along the maturing Golgi cisternae starting from a pronounced dilated "polymerization center" as a completely intracisternal process which ends in the exocytotic extrusion of the scales. The scales reveal the very same ultrastructure within the Golgi cisternae as they do in the cell wall. The present finding represents the first evidence on cellulose formation by the Golgi apparatus and is discussed in relation to a basic scheme for cellulose synthesis in plant cells in general. PMID:5513606

Brown, R. Malcolm; Franke, Werner W.; Kleinig, Hans; Falk, Heinz; Sitte, Peter

1970-01-01

109

[Algae removal of high algae raw water by coagulation enhanced by ozonation].  

PubMed

Apparent molecular weight distribution (AMWD) and resin fractionation were used to characterize organic matters of the raw water. Removal of algae, change and removal of dissolved organic carbon (DOC), disinfection by products (DBPs) control during the preozonation enhanced coagulation treatments in the jar-scale and pilot-scale experiment were studied. Algae activity (AA) was measured and used to elucidate the mechanisms of algae removal by above treatments. Results show that algae removal can be improved distinctively by proper preozonation, as the ozone dose 1.0 mg x L(-1), for instance. Algae removal could be increased from 55%-85% by traditional coagulation to 95% by enhanced coagulation after preozonation; and the best removal achieved 99.3% with ozone 1.0 mg x L(-1) and PACl 3.0 mg x L(-1); the residual THMFP (Trihalomethanes formation potential) was lowered from 117 microg x L(-1) by traditional coagulation to 46 microg x L(-1). But higher dose of ozone (as > or = 2.0 mg x L(-1)) impairs organic matter removal, although it decreases algae activity further. Significant differences were found in algae removal by AA detection between ozonation and traditional coagulation. Traditional coagulation had little effect on AA no matter the different PAC1 doses; while AA decreased clearly after ozonation. AA was lowered below 12 under 0.5-2.0 mg x L(-1) ozonation; and it kept decreasing with increase of ozone dosage. During the following coagulation, coagulant or some of its hydrolysised components enhanced the AA decrease by ozonation. Compared to the method of normal microscopy counting, AA test expresses the influence of algae living state by water treatment processes more clearly; which would provide treatment process designer with more distinct information about algae removal mechanisms and how to arrange the treatment processes to improve algae removal. PMID:19774984

Liu, Hai-Long; Yang, Dong; Zhao, Zhi-Yong; Li, Zheng-Jian; Cheng, Fang-Qin

2009-07-15

110

PPR proteins of green algae  

PubMed Central

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

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

2013-01-01

111

Oil from algae; salvation from peak oil?  

PubMed

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

Rhodes, Christopher J

2009-01-01

112

Lipids and lipid metabolism in eukaryotic algae.  

PubMed

Eukaryotic algae are a very diverse group of organisms which inhabit a huge range of ecosystems from the Antarctic to deserts. They account for over half the primary productivity at the base of the food chain. In recent years studies on the lipid biochemistry of algae has shifted from experiments with a few model organisms to encompass a much larger number of, often unusual, algae. This has led to the discovery of new compounds, including major membrane components, as well as the elucidation of lipid signalling pathways. A major drive in recent research have been attempts to discover genes that code for expression of the various proteins involved in the production of very long-chain polyunsaturated fatty acids such as arachidonic, eicosapentaenoic and docosahexaenoic acids. Such work is described here together with information about how environmental factors, such as light, temperature or minerals, can change algal lipid metabolism and how adaptation may take place. PMID:16492482

Guschina, Irina A; Harwood, John L

2006-03-01

113

Genome of the red alga Porphyridium purpureum  

PubMed Central

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

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; Zauner, Simone; Morath, Shannon; Hilliou, Frederique; Egizi, Andrea; Perrineau, Marie-Mathilde; Yoon, Hwan Su

2013-01-01

114

Turning Algae into Energy in New Mexico  

ScienceCinema

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.

Sayre, Richard; Olivares, Jose; Lammers, Peter

2014-06-24

115

Turning Algae into Energy in New Mexico  

SciTech Connect

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.

Sayre, Richard; Olivares, Jose; Lammers, Peter

2013-07-29

116

Genome of the red alga Porphyridium purpureum.  

PubMed

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

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; Zäuner, Simone; Morath, Shannon; Hilliou, Frédérique; Egizi, Andrea; Perrineau, Marie-Mathilde; Yoon, Hwan Su

2013-01-01

117

Algae control problems and practices workshop  

SciTech Connect

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.

Pryfogle, P.A. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Ghio, G. [Pacific Gas and Electric Co., San Francisco, CA (United States)

1996-09-01

118

Application of intact algae to the biophotolysis  

SciTech Connect

The utilization of intact algae for the simultaneous light-activated production of molecular hydrogen and oxygen is discussed. Experimental data on the long-term stability and endurance of hydrogen and oxygen photoproduction by anaerobically adapted Chlamydomonas reinhardtii is presented. The general conclusion that can be derived from this work is that Chlamydomonas (and probably other microscopic eukaryotic algae) are extremely rugged organisms with respect to the biophotolysis problem. Working with a sample of wild-type Chlamydomonas reinhardtii, the simultaneous photoproduction of hydrogen and oxygen was observed for approximately 100 h. The bleached algae were then removed from the reactor and used as the inoculum in fresh growth medium. These second-generation cells regreened and were able to photoproduce hydrogen and oxygen initially at ten times the rate of the first generation cells and had better survivability characteristics as indicated by their chlorophyll content after 200 h. 2 figures.

Greenbaum, E.

1982-01-01

119

Use of Brown Algae to Demonstrate Natural Products Techniques.  

ERIC Educational Resources Information Center

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)

Porter, Lee A.

1985-01-01

120

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)...

121

BOTANICAL BRIEFING Streptophyte algae and the origin of embryophytes  

E-print Network

streptophyte algae. Molecular phylogenies and the fossil record allow a detailed reconstruction of the early of streptophyte algae started approx. 470­450 MY ago (Ordovician period; reviewed in Sanderson et al., 2004

122

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. ...

123

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...

124

Life cycle analysis of algae biodiesel  

Microsoft Academic Search

Background, aim, and scope  Algae biomass has great promise as a sustainable alternative to conventional transportation fuels. In this study, a well-to-pump\\u000a life cycle assessment (LCA) was performed to investigate the overall sustainability and net energy balance of an algal biodiesel\\u000a process. The goal of this LCA was to provide baseline information for the algae biodiesel process.\\u000a \\u000a \\u000a \\u000a \\u000a Materials and methods  The functional

Kyle Sander; Ganti S. Murthy

2010-01-01

125

Acetylene reduction by nitrogen-fixing blue-green algae  

Microsoft Academic Search

Known nitrogen-fixing species of blue-green algae are capable of reducing acetylene to ethylene, but acetylene is not reduced by Anacystis nidulans, which does not fix nitrogen. Cycad root nodules which contain blue-green algae as endophytes reduce acetylene. Acetylene reduction is inhibited by carbon monoxide. Nitrate or ammonium-nitrogen has no immediate effect on algae reducing acetylene, but algae grown on nitrate-nitrogen

W. D. P. Stewart; G. P. Fitzgerald; R. H. Burris

1968-01-01

126

HARMFUL ALGAE POSE ADDITIONAL CHALLENGES FOR OYSTER RESTORATION: IMPACTS OF THE HARMFUL ALGAE KARLODINIUM VENEFICUM AND PROROCENTRUM  

E-print Network

HARMFUL ALGAE POSE ADDITIONAL CHALLENGES FOR OYSTER RESTORATION: IMPACTS OF THE HARMFUL ALGAE KARLODINIUM VENEFICUM AND PROROCENTRUM MINIMUM ON EARLY LIFE STAGES OF THE OYSTERS CRASSOSTREA VIRGINICA 775, Cambridge, Maryland 21613 ABSTRACT The eastern oyster, Crassostrea virginica (Gmelin, 1791) has

North, Elizabeth W.

127

How to Identify and Control Water Weeds and Algae.  

ERIC Educational Resources Information Center

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…

Applied Biochemists, Inc., Mequon, WI.

128

Sedimentation of algae: relationships with biomass and size distribution1  

E-print Network

Sedimentation of algae: relationships with biomass and size distribution1 Isabelle Larocque, A distribution of epilimnetic algae on patterns of algal sedimentation was determined in lake enclosures under the mean length of algae in fish-free enclosures and reduced the mean length in the enclosures to which

Mazumder, Asit

129

Environmental Life Cycle Comparison of Algae to Other Bioenergy  

E-print Network

Environmental Life Cycle Comparison of Algae to Other Bioenergy Feedstocks A N D R E S F . C L A R December 6, 2009. Accepted December 15, 2009. Algae are an attractive source of biomass energy since. In spite of these advantages, algae cultivation has not yet been compared with conventional crops from

Clarens, Andres

130

Seeing Toxic Algae Before it Blooms By Steve Ress  

E-print Network

Seeing Toxic Algae Before it Blooms By Steve Ress Researchers at the University of Nebraska of toxic blue-green algae before the bacteria that produce it can grow into a full-scale bloom. Now UNL and monitor in real-time, the water-borne agents that can cause toxic blue- green algae to flourish and become

Nebraska-Lincoln, University of

131

AQU 04 Portable Algae Flow Cytometer Team Members  

E-print Network

AQU 04 Portable Algae Flow Cytometer Team Members · David Caron, Faculty · Han-Chieh Chang · Yu-Chong Tai, Faculty, PI* * Primary Contact Overview The portable algae flow cytometer is a project that aims to expedite research in algae biology using microfluid-based and state-of-the-art detection

California at Los Angeles, University of

132

Analysis of Land Suitable for Algae State of Hawaii  

E-print Network

. Increased demand for biofuels has increased interest in growing algae in Hawaii for biofuels. An analysisAnalysis of Land Suitable for Algae Production State of Hawaii Prepared for the U.S. Department agency thereof. #12;Analysis of Land Suitable for Algae Production State of Hawaii Prepared by Mele

133

Development of suitable photobioreactor for algae production – A review  

Microsoft Academic Search

Microalgal species are recently in the spotlight for biofuels production like biodiesel, bioethanol and biohydrogen. Algae are also used as a biofertiliser, source of nutrient and for controlling pollution. Algae being a photosynthetic organism are produced in the photo bioreactors. Hence the design and development of photobioreactors for maximum production of algae is very important. Apart from maximum production, other

R. N. Singh; Shaishav Sharma

2012-01-01

134

COMBO: a defined freshwater culture medium for algae and zooplankton  

Microsoft Academic Search

In order to conduct experiments on interactions between animals and food organisms, it is necessary to develop a medium that adequately supports the growth of both algae and zooplankton without the need to alter the medium to accommodate either the algae or the animals. We devised a freshwater medium, named COMBO, that supports excellent growth of both algae and zooplankton.

Susan S. Kilham; A. Kreeger; Scott G. Lynn; Clyde E. Goulden; Lazaro Herrera

1998-01-01

135

The origin of red algae and the evolution of chloroplasts  

Microsoft Academic Search

Chloroplast structure and genome analyses support the hypothesis that three groups of organisms originated from the primary photosynthetic endosymbiosis between a cyanobacterium and a eukaryotic host: green plants (green algae + land plants), red algae and glaucophytes (for example, Cyanophora). Although phylogenies based on several mitochondrial genes support a specific green plants\\/red algae relationship, the phylogenetic analysis of nucleus-encoded genes

David Moreira; Hervé Le Guyader; Hervé Philippe

2000-01-01

136

Photophysiology and cellular composition of sea ice algae  

Microsoft Academic Search

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

Lizotte

1989-01-01

137

CORALLINE ALGA STANDS THE TEST OF TIME ON SHORELINE  

E-print Network

Inside JEB i CORALLINE ALGA STANDS THE TEST OF TIME ON SHORELINE No one likes getting bashed about, the coralline algae, which have calcified most of their cells and essentially turned themselves into living, and thus most of force, occurring at the small joints (they make up just 15% of the alga), Denny wondered

Martone, Patrick T.

138

Intracellular invasion of green algae in a salamander host  

E-print Network

Intracellular invasion of green algae in a salamander host Ryan Kerneya,1 , Eunsoo Kimb , Roger P) and green algae ("Oophila amblystomatis" Lamber ex Printz) has been considered an ectosymbiotic mutu- alism tracts, consistent with oviductal transmission of algae from one salamander generation to the next

139

Global Dynamics of Zooplankton and Harmful Algae in Flowing Habitats  

E-print Network

Global Dynamics of Zooplankton and Harmful Algae in Flowing Habitats Sze-Bi Hsu Feng-Bin Wang Xiao from the dynamics of harmful algae and zooplankton in flowing- water habitats where a main channel. For the system modeling the dynamics of algae and their toxin that contains little limiting nutrient, we

Hsu, Sze-Bi

140

Gille-STPA 35 1 Noxious Algae in Carlsbad  

E-print Network

Gille-STPA 35 1 Noxious Algae in Carlsbad Spanish explorers of this region came across a lagoon Woodfield Dubbed "killer algae," the alien seaweed Caulerpa taxifolia was discovered in June 2000. Caulerpa taxifolia is a green alga native to tropical waters that typically grows to small size

Gille, Sarah T.

141

Algae and cyanotoxins removal by coagulation\\/flocculation: A review  

Microsoft Academic Search

A continuing worldwide problem for drinking water treatment industry is the presence of algae in source water. Algae in drinking water supply can cause significant disturbances including taste and odour, production of disinfection by-product, obstruction to coagulation, clogging of filter, and assimilable organic carbon for growth of biofilm. Algae removal by conventional treatment is more difficult than inorganic particle, due

Badiaa Ghernaout; Djamel Ghernaout; Ali Saiba

2010-01-01

142

Lab 7: Nitrates and Phosphates and Algae, Oh My!  

NSDL National Science Digital Library

Human-induced nutrient loading of the world's oceans has been linked to increased and prolonged algae blooms, sometimes with potentially deadly consequences. In this investigation, students will create their own algal blooms, analyze satellite images of chlorophyll concentrations in the Sea of CortÃs, and learn about two alarming consequences of excessive algae growth-—dead zones and harmful algae blooms (HABs).

143

The Ecological Significance of Sexual Reproduction by Tropical Green Algae  

E-print Network

, herbivory on fertile algae, the nature and timing of gamete release, fertilization success, and zygoteThe Ecological Significance of Sexual Reproduction by Tropical Green Algae Kenneth E. Clifton on numerous fronts, however, the basic ecology of many important groups, includ- ing the tropical green algae

Clifton, Ken

144

Pheromone signaling during sexual reproduction in algae.  

PubMed

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

Frenkel, Johannes; Vyverman, Wim; Pohnert, Georg

2014-08-01

145

Changes in chloroplast structure in lichenized algae  

Microsoft Academic Search

Chloroplast morphology represents a basic characteristic in the systematic classification of trebouxioid algae. However, in different ontogenetic, physiological and ecological stages chloroplasts may vary markedly. Various developmental states of two algal species (Asterochloris sp. and Trebouxia incrustata) isolated from four lichens (Cladonia foliacea, Lecidea fuscoatra, Lepraria sp., Xanthoparmelia conspersa) were examined by confocal microscopy for variations in chloroplast structure. Distinct

O. Peksa; P. Skaloud

2008-01-01

146

Bromophenols in Marine Algae and Their Bioactivities  

PubMed Central

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

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

2011-01-01

147

Laser-fluorescence measurement of marine algae  

NASA Technical Reports Server (NTRS)

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.

Browell, E. V.

1980-01-01

148

Spirulina: The Alga That Can End Malnutrition.  

ERIC Educational Resources Information Center

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)

Fox, Ripley D.

1985-01-01

149

Biofuels from algae for sustainable development  

Microsoft Academic Search

Microalgae are photosynthetic microorganisms that can produce lipids, proteins and carbohydrates in large amounts over short periods of time. These products can be processed into both biofuels and useful chemicals. Two algae samples (Cladophora fracta and Chlorella protothecoid) were studied for biofuel production. Microalgae appear to be the only source of renewable biodiesel that is capable of meeting the global

M. Fatih Demirbas

2011-01-01

150

Bacterial Grazing by Planktonic Lake Algae  

Microsoft Academic Search

Six common species of lake algae were found to ingest bacteria. The ingestion rates measured were of the same magnitude as those recorded for marine microflagellates totally dependent on external sources of carbon. A large biomass of Dinobryon species removed more bacteria from the water column of a lake than crustaceans, rotifers, and ciliates combined.

David F. Bird; Jacob Kalff

1986-01-01

151

Golden Alga (Prymnesium parvum) An Emerging Threat  

E-print Network

flagella, for motility · Short haptonema, possibly for attachment or food acquisition · Gain nutrition of salinity Minimum for blooms (0.5-1 psu, 2000 S/cm) · Water takes golden coloration during blooms, foam, TPWD flagella haptonema #12;4 Golden Alga Picture credits: TPWD #12;5 Shoreline Foam Picture credits

US Army Corps of Engineers

152

Screening for bioactive compounds from algae  

Microsoft Academic Search

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

M. Plaza; S. Santoyo; L. Jaime; G. García-Blairsy Reina; M. Herrero; F. J. Señoráns; E. Ibáñez

2010-01-01

153

Underwater fertilization dynamics of marine green algae  

Microsoft Academic Search

We studied the fertilization dynamics of marine green algae with both analytical methods and numerical simulations. In this study, we focused on a new factor, gametic investment per unit volume of the space in which gametes searched for their partners, and compared the numbers of zygotes formed at lower investments with those at higher investments. As a function of the

Tatsuya Togashi; Paul Alan Cox; John L. Bartelt

2007-01-01

154

Sulfated polysaccharides as bioactive agents from marine algae.  

PubMed

Recently, much attention has been paid by consumers toward natural bioactive compounds as functional ingredients in nutraceuticals. Marine algae are considered as valuable sources of structurally diverse bioactive compounds. Marine algae are rich in sulfated polysaccharides (SPs) such as carrageenans in red algae, fucoidans in brown algae and ulvans in green algae. These SPs exhibit many health beneficial nutraceutical effects such as antioxidant, anti-allergic, anti-human immunodeficiency virus, anticancer and anticoagulant activities. Therefore, marine algae derived SPs have great potential to be further developed as medicinal food products or nutraceuticals in the food industry. This contribution presents an overview of nutraceutical effects and potential health benefits of SPs derived from marine algae. PMID:23994790

Ngo, Dai-Hung; Kim, Se-Kwon

2013-11-01

155

Algae columns with anodic stripping voltammetric detection  

SciTech Connect

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.

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

1989-03-01

156

Environmental life cycle comparison of algae to other bioenergy feedstocks.  

PubMed

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

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

2010-03-01

157

Studies on polyethers produced by red algae.  

PubMed

Two novel squalene-derived triterpenes, spirodehydrovenustatriol (3) and 14-keto-dehydrothyrsiferol (4) were isolated from the red alga Laurencia viridis, together with two new and unusual C(17) terpenoids, adejen A (5) and B (6). These truncated structures possess structural similarities with other known squalene metabolites and their biogenetic origin has been proposed on the basis of an oxidative process of the squalene skeleton. All the structures were elucidated by extensive use of 2D NMR spectroscopic methods. PMID:20479973

Cen-Pacheco, Francisco; Nordström, Laurette; Souto, María Luisa; Martín, Manuel Norte; Fernández, José Javier; Daranas, Antonio Hernández

2010-01-01

158

Algae as Reservoirs for Coral Pathogens  

PubMed Central

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

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

2013-01-01

159

Sequestration of CO2 by halotolerant algae  

PubMed Central

The potential of halotolerant algae isolated from natural resources was used to study CO2 fixation and algal lipid production. Biological fixation of CO2 in photobioreactor in presence of salinity is exploited. The CO2 concentration 1060 ppm gave the highest biomass yield (700 mg dry wt/l), the highest total lipid content (10.33%) with 80% of CO2 removal. PMID:24847439

2014-01-01

160

Cytoplasmic inheritance of organelles in brown algae.  

PubMed

Brown algae, together with diatoms and chrysophytes, are a member of the heterokonts. They have either a characteristic life cycle of diplohaplontic alternation of gametophytic and sporophytic generations that are isomorphic or heteromorphic, or a diplontic life cycle. Isogamy, anisogamy and oogamy have been recognized as the mode of sexual reproduction. Brown algae are the characteristic group having elaborated multicellular organization within the heterokonts. In this study, cytoplasmic inheritance of chloroplasts, mitochondria and centrioles was examined, with special focus on sexual reproduction and subsequent zygote development. In oogamy, chloroplasts and mitochondria are inherited maternally. In isogamy, chloroplasts in sporophyte cells are inherited biparentally (maternal or paternal); however, mitochondria (or mitochondrial DNA) derived from the female gamete only remained during zygote development after fertilization. Centrioles in zygotes are definitely derived from the male gamete, irrespective of the sexual reproduction pattern. Female centrioles in zygotes are selectively broken down within 1-2 h after fertilization. The remaining male centrioles play a crucial role as a part of the centrosome for microtubule organization, mitosis, determination of the cytokinetic plane and cytokinesis, as well as for maintaining multicellularity and regular morphogenesis in brown algae. PMID:20145971

Motomura, Taizo; Nagasato, Chikako; Kimura, Kei

2010-03-01

161

Blue-green algae toxicosis in cattle.  

PubMed

Twenty-four of 175 heifers died after ingesting water from a stock pond containing blue-green algae (genus Microcystis) in southern Colorado. Affected cattle were found dead or had signs of nervousness, and were recumbent, weak, anorectic, and hypersensitive to noise when first examined. All cattle died within 3 days after the onset of signs. At necropsy, the rumen contained blue-green algae, and the liver was larger than normal, friable, and dark red. The most important histologic lesion was hepatocyte degeneration and necrosis. Intraperitoneal administration of lyophilized cell material from the bloom caused hepatic necrosis and death in mice, and water from the pond had clumps of cells surrounded by a clear calyx, consistent with the appearance of organisms of the genus Microcystis. Samples of pond water were examined by means of high-pressure liquid chromatography; microcystin-LR, one of the hepatotoxins produced by Microcystis spp, was found. Chromatography may be useful in the diagnosis of blue-green algae toxicosis. PMID:9838962

Puschner, B; Galey, F D; Johnson, B; Dickie, C W; Vondy, M; Francis, T; Holstege, D M

1998-12-01

162

RESEARCH ARTICLE Open Access Origin of land plants: Do conjugating green algae  

E-print Network

RESEARCH ARTICLE Open Access Origin of land plants: Do conjugating green algae hold the key? Sabina (embryophytes) evolved from streptophyte algae, also referred to as charophycean algae. The streptophyte algae are a paraphyletic group of green algae, ranging from unicellular flagellates to morphologically complex forms

163

Microplate Technique for Determining Accumulation of Metals by Algae  

PubMed Central

A microplate technique was developed to determine the conditions under which pure cultures of algae removed heavy metals from aqueous solutions. Variables investigated included algal species and strain, culture age (11 and 44 days), metal (mercury, lead, cadmium, and zinc), pH, effects of different buffer solutions, and time of exposure. Plastic, U-bottomed microtiter plates were used in conjunction with heavy metal radionuclides to determine concentration factors for metal-alga combinations. The technique developed was rapid, statistically reliable, and economical of materials and cells. Results (expressed as concentration factors) were in reasonably good agreement with literature values. All species of algae studied removed mercury from solution. Green algae proved better at accumulating cadmium than did blue-green algae. No alga studied removed zinc, perhaps because cells were maintained in the dark during the labeling period. Chlamydomonas sp. proved superior in ability to remove lead from solution. PMID:16345764

Hassett, James M.; Jennett, J. Charles; Smith, James E.

1981-01-01

164

Global dynamics of zooplankton and harmful algae in flowing habitats  

NASA Astrophysics Data System (ADS)

This paper is devoted to the study of two advection-dispersion-reaction models arising from the dynamics of harmful algae and zooplankton in flowing-water habitats where a main channel is coupled to a hydraulic storage zone, representing an ensemble of fringing coves on the shoreline. For the system modeling the dynamics of algae and their toxin that contains little limiting nutrient, we establish a threshold type result on the global attractivity in terms of the basic reproduction ratio for algae. For the model with zooplankton that eat the algae and are inhibited by the toxin produced by algae, we show that there exists a coexistence steady state and the zooplankton is uniformly persistent provided that two basic reproduction ratios for algae and zooplankton are greater than unity.

Hsu, Sze-Bi; Wang, Feng-Bin; Zhao, Xiao-Qiang

165

Eradication of algae in ships' ballast water by electrolyzing  

NASA Astrophysics Data System (ADS)

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.

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

2006-12-01

166

Method for producing hydrogen and oxygen by use of algae  

DOEpatents

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.

Greenbaum, E.

1982-06-16

167

Method for producing hydrogen and oxygen by use of algae  

DOEpatents

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.

Greenbaum, Elias (Oak Ridge, TN)

1984-01-01

168

Algae to Bio-Crude in Less Than 60 Minutes  

ScienceCinema

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.

Elliott, Doug

2014-06-02

169

Toxic and deadly: Working to manage algae in Lake Granbury  

E-print Network

Toxic and deadly Working to manage algae in Lake Granbury Lake Granbury, located about 33 miles southwest of Fort Worth, is a recreation haven for water enthusiasts. In recent years, however, bacteria and golden algae have threatened the lake?s... water quality. Educating citizens about water quality issues affecting Lake Granbury and determining ways to manage the deadly algae are the focus of two Texas Water Resources Institute (TWRI) projects. Lake Granbury, a critical water supply...

Wythe, Kathy

2011-01-01

170

Toxic and deadly: Working to manage algae in Lake Granbury  

E-print Network

Toxic and deadly Working to manage algae in Lake Granbury Lake Granbury, located about 33 miles southwest of Fort Worth, is a recreation haven for water enthusiasts. In recent years, however, bacteria and golden algae have threatened the lake?s... water quality. Educating citizens about water quality issues affecting Lake Granbury and determining ways to manage the deadly algae are the focus of two Texas Water Resources Institute (TWRI) projects. Lake Granbury, a critical water supply...

Wythe, Kathy

2010-01-01

171

Heterotrophic Growth of Blue-Green Algae in Dim Light  

PubMed Central

A unicellular blue-green alga, Agmenellum quadruplicatum, and a filamentous blue-green alga, Lyngbya lagerheimíi, were grown heterotrophically in dim light with glucose as major source of carbon and possibly energy. The dim-light conditions did not support autotrophic growth. The two blue-green algae appeared to have the same metabolic block, namely an incomplete tricarboxylic acid cycle, as has been found in other obligately phototrophic blue-green algae. Under dim-light conditions, glucose made a greater contribution to cell constituents (amino acids) of A. quadruplicatum and L. lagerheimii than under high-light conditions. PMID:4994034

Van Baalen, Chase; Hoare, Derek S.; Brandt, Ellen

1971-01-01

172

Parachloroidium gen. nov. (Trebouxiophyceae, Chlorophyta), a novel genus of coccoid green algae from subaerial corticolous biofilms  

E-print Network

Parachloroidium gen. nov. (Trebouxiophyceae, Chlorophyta), a novel genus of coccoid green algae. Parachloroidium gen. nov. (Trebouxiophyceae, Chlorophyta), a novel genus of coccoid green algae from subaerial the Parachloroidium strains from other similar green algae. However, ultrastructural characteristics and molecular

173

Field Study of Growth and Calcification Rates of Three Species of Articulated Coralline Algae in  

E-print Network

Field Study of Growth and Calcification Rates of Three Species of Articulated Coralline Algae of coralline algae. Decreases in coralline abundance may have cascading effects on marine ecosys- tems- mon species of articulated coralline algae (Bossiella plu- mosa, Calliarthron tuberculosum

Martone, Patrick T.

174

Inorganic carbon acquisition in some synurophyte algae.  

PubMed

Some characteristics of photosynthesis of three synurophyte algae, Synura petersenii, Synura uvella and Tessellaria volvocina were investigated to determine the mechanism of inorganic carbon (C(i)) uptake. All three species were found to have no external carbonic anhydrase, no capacity for direct bicarbonate uptake and a low whole-cell affinity for C(i). The internal pH of S. petersenii determined using (14)C-benzoic acid and [2-(14)C]-5,5-dimethyloxazolidine-2,4-dione was pH 7.0-7.5, over an external pH range of 5.0-7.5. Thus, the pH difference between the cell interior of S. petersenii and the external medium was large enough, over the alga's growth range, to allow the accumulation of C(i) by the diffusive uptake of CO(2). Monitoring O(2) evolution and CO(2) uptake by suspensions of S. petersenii at pH 7.0 by mass spectrometry did not indicate a rapid uptake of CO(2), and the final CO(2) compensation concentration reached was 24 +/- 0.7 microM. Furthermore, when the cells were darkened, a brief burst of CO(2) occurred before a steady rate of dark respiration was established, suggesting a loss of CO(2) by photorespiration. An examination of the kinetics of ribulose-1,5-bisphosphate carboxylase/oxygenase in homogenates of cells of S. petersenii, S. uvella and Mallomonas papillosa showed that values of the K(m) (CO(2)) were 28.4, 41.8 and 18.2 microM, respectively. These species lack the characteristics of cells with a CO(2)-concentrating mechanism because the cell affinity for C(i) appears to be determined by the relatively high CO(2) affinity of the Rubisco of these algae. PMID:18298411

Bhatti, Shabana; Colman, Brian

2008-05-01

175

Steroids from green alga Chaetomorpha basiretorsa Setchell  

NASA Astrophysics Data System (ADS)

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 ?-lawsaritol (1), saringosterol (2), 24-hydroperoxy-24-vinyl-cholesterol (3), ?-stigmasterol (4), stigmast-4-en-3?, 6?-diol (5), 29-hydroxystigmasta-5, 24 (28)-dien-3?-ol (6). All these compounds were obtained from this genus for the first time and they were inactive (IC50>10 ?g /ml) against KB, Bel-7402, PC-3M, Ketr 3 and MCF-7 cell lines.

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

2008-11-01

176

Blue-Green Algae: Why They Become Dominant  

Microsoft Academic Search

The injection of carbon dioxide and the addition of nitrogen and phosphorus to a lake population dominated by blue-green algae results in a rapid shift to dominance by green algae. The basis for the change and its implications are discussed.

Joseph Shapiro

1973-01-01

177

Update on Genomic Studies of Algae Paths toward Algal Genomics  

E-print Network

Update on Genomic Studies of Algae Paths toward Algal Genomics Arthur R. Grossman* The Carnegie of genomic information that is being used to help researchers understand the gene content of organisms, how the expression of genes. In this introductory manuscript, I discuss select algae and how genomics is impacting

178

CEC-500-2010-FS-001 Algae OMEGA  

E-print Network

CEC-500-2010-FS-001 Algae OMEGA (Offshore Membrane Enclosures For Growing Algae) TRANSPORTATION expensive to make into commercially viable biofuels that are necessary to reduce greenhouse gas (GHG amount of carbon-neutral, sustainable biofuels when they are grown in large quantities under economical

179

Fate of Model Xenobiotics in Calcareous Marine Algae  

Microsoft Academic Search

Uptake, depuration, and metabolism ofp-nitroanisole (PNA) and p-nitrophenol (PNP) were investigated in Halimeda, Padina, and Porolithon species, all of which are calcareous marine algae found in tropical waters . The algae were exposed to filtered seawater solutions of either PNA or PNP in a static system for 24 hr (uptake period), then placed in clean water and allowed to release

LAURA S. INOUYE

1991-01-01

180

Phenolic-based Adhesives of Marine Brown Algae  

Microsoft Academic Search

Brown algae, such as kelps and fucoids, occur over large areas of the subtidal and intertidal rocky shores, including tropical reef habitats, producing high biomass and determining the structure of the ecosystem (i.e. kelp forests). Brown algae live firmly attached to the substratum and are often exposed to high gradients of turbulence. Therefore, they experience drag and lift forces of

Philippe Potin; Catherine Leblanc

181

Plastid Genomes of Higher Plants and Algae: Structure and Functions  

Microsoft Academic Search

The data on the structure and gene composition in completely sequenced plastid (predominantly chloroplast) genomes of higher plants and algae are reviewed. In higher plants, genome structure and gene composition are highly conserved. Plastid genomes of algae are less conserved and contain several unique genes, which are not found in chloroplast DNAs of higher plants. Plastid genomes encode proteins involved

M. S. Odintsova; N. P. Yurina

2003-01-01

182

Biosorption of lead and nickel by biomass of marine algae  

Microsoft Academic Search

Screening tests of different marine algae biomass 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 performed particularly well in this descending sequence: Fucus > Ascophyllum > Sargassum. Although decreasing the swelling of wetted biomass particles, their reinforcement by crosslinking may significantly affect

Z. R. Holan; B. Volesky

1994-01-01

183

Analysis of cell elongation in red algae by fluorescent labelling  

Microsoft Academic Search

The mechanism of cell elongation in five red algae, Griffithsia pacifica Kylin, G. tenuis C. Agardh, G. globulifera Harvey, Antithamnion kylinii Gardner, and Callithamnion sp. was studied using Calcofluor White ST as a vital, fluorescent cell-wall stain. In each alga elongation of intercalary shoot cells occurs primarily by the localized addition of new cell-wall material rather than by extension of

Susan Drury Waaland; J. Robert Waaland

1975-01-01

184

Oily Products from Mosses and Algae via Pyrolysis  

Microsoft Academic Search

In this study, the fuel properties of mosses and algae, and the effect of pyrolysis temperature on the yield of bio-oil from moss and alga samples, were investigated. The yield of bio-oil from pyrolysis of the samples increased with temperature. The yields were increased up to 750 K in order to reach the plateau values at 775 K. The maximum

Ayhan Demirba?

2006-01-01

185

Aridity and Algae: Biodiesel Production in Arizona Jenna Bloxom  

E-print Network

Aridity and Algae: Biodiesel Production in Arizona Jenna Bloxom Advisor: Dr. Scott Whiteford Center and biodiesel industry in Arizona on the state's water supply and policies. Analyzing potential political extensive literature review of current publications and studies concerning algae biomass and biodiesel

Fay, Noah

186

Respiratory Chain of Colorless Algae II. Cyanophyta  

PubMed Central

Whole cell difference spectra of the blue-green algae, Saprospira grandis, Leucothrix mucor, and Vitreoscilla sp. have one, or at the most 2, broad ?-bands near 560 m?. At ?190° these bands split to give 4 peaks in the ?-region for b and c-type cytochromes, but no ?-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 m?. The action spectrum for the light reversal of CO-inhibited Vitreoscilla respiration shows maxima at 568, 534, and 416 m?. The results suggest that the terminal oxidase in these blue-greens is an o-type cytochrome. Images PMID:5932404

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

1966-01-01

187

Algae-based oral recombinant vaccines  

PubMed Central

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

Specht, Elizabeth A.; Mayfield, Stephen P.

2014-01-01

188

Viruses and viruslike particles of eukaryotic algae.  

PubMed Central

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

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

1991-01-01

189

Spectral optical properties of selected photosynthetic microalgae producing biofuels  

NASA Astrophysics Data System (ADS)

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.

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

2013-01-01

190

Swimming like algae: biomimetic soft artificial cilia  

PubMed Central

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

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

2013-01-01

191

Antileishmanial properties of tropical marine algae extracts.  

PubMed

Aqueous and organic extracts of twenty-seven species of marine algae (14 species of Rhodophyta, 5 species of Phaeophyta and 8 species of Chlorophyta) collected from the Gulf of Mexico and Caribbean coast of the Yucatan Peninsula (Mexico) were evaluated for their antileishmanial in vitro activity against Leishmania mexicana promastigote forms. The cytotoxicity of these extracts was also assessed using brine shrimp. Organic extracts from Laurencia microcladia (Rhodophyta), Dictyota caribaea, Turbinaria turbinata and Lobophora variegata (Phaeophyta) possessed promising in vitro activity against L. mexicana promastigotes (LC(50) values ranging from 10.9 to 49.9 microg/ml). No toxicity of algal extracts against Artemia salina was observed with LC50 ranging from 119 to >or=1000 microg/ml. Further studies on bio-guided fractionation, isolation and characterization of pure compounds from these species as well as in vivo experiments are needed and are already in progress. PMID:18504078

Freile-Pelegrin, Y; Robledo, D; Chan-Bacab, M J; Ortega-Morales, B O

2008-07-01

192

[Seasonal variation characteristics of algae biomass in Chaohu Lake].  

PubMed

The biomass and distribution of algae community in Chaohu Lake were investigated in 2008. At the same time, the seasonal variations of algae translocation between the sediment and overlying water were also quantitative studied by self-made "algae up/down trap". Chaohu Lake was dominated by Cyanobacteria all the year, and dominant Cyanobacteria species changed in different seasons. In spring, Anabaena was the dominant species, and Microcystis was the subdominant species; In the whole summer and autumn, the dominant species is Microcystis. Algae biomass increased significantly from May and the maximum appeared in August, was 146.37 mg x m(-3) with Chl-a. The value of algae biomass were 9.75-16.24 mg x kg(-1) in the surface sediments, and the minimum appeared in Summer, then the algae biomass increased gradually with the maximum value in winter. Translocation process between the sediment and the overlying water occurred throughout the study period. The recruitment rates increased at first with the maximum rates in early August, was 0.036 8 mg x (m2 x d) (-1), and then had a downward tendency. However the sedimentation rates increased slowly firstly with the maximum rate in early September, then it decreased sharply, was 0.032 1 mg x (m2 x d)(-1). Multiple stepwise regression showed that temperature was the most significant factor for the algae biomass in Chaohu Lake, Total nitrogen (TN) and Total phosphorus(TP) are sub-important factors. PMID:21072924

Jiang, Xia; Wang, Shu-Hang; Zhong, Li-Xiang; Jin, Xiang-Can; Sun, Shi-Qun

2010-09-01

193

Activated chemical defenses suppress herbivory on freshwater red algae.  

PubMed

The rapid life cycles of freshwater algae are hypothesized to suppress selection for chemical defenses against herbivores, but this notion remains untested. Investigations of chemical defenses are rare for freshwater macrophytes and absent for freshwater red algae. We used crayfish to assess the palatability of five freshwater red algae relative to a palatable green alga and a chemically defended aquatic moss. We then assessed the roles of structural, nutritional, and chemical traits in reducing palatability. Both native and non-native crayfish preferred the green alga Cladophora glomerata to four of the five red algae. Batrachospermum helminthosum, Kumanoa holtonii, and Tuomeya americana employed activated chemical defenses that suppressed feeding by 30-60 % following damage to algal tissues. Paralemanea annulata was defended by its cartilaginous structure, while Boldia erythrosiphon was palatable. Activated defenses are thought to reduce ecological costs by expressing potent defenses only when actually needed; thus, activation might be favored in freshwater red algae whose short-lived gametophytes must grow and reproduce rapidly over a brief growing season. The frequency of activated chemical defenses found here (three of five species) is 3-20× higher than for surveys of marine algae or aquatic vascular plants. If typical for freshwater red algae, this suggests that (1) their chemical defenses may go undetected if chemical activation is not considered and (2) herbivory has been an important selective force in the evolution of freshwater Rhodophyta. Investigations of defenses in freshwater rhodophytes contribute to among-system comparisons and provide insights into the generality of plant-herbivore interactions and their evolution. PMID:23011851

Goodman, Keri M; Hay, Mark E

2013-04-01

194

Photophysiology and cellular composition of sea ice algae  

SciTech Connect

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.

Lizotte, M.P.

1989-01-01

195

University of Texas-Austin: The Culture Collection of Algae  

NSDL National Science Digital Library

Housed at the University of Texas-Austin, The Culture Collection of Algae "includes over 2,300 different strains of living algae, representing most major algal taxa. The primary function of UTEX is to provide algal cultures at modest cost to a user community." The cultures are generally utilized for teaching, research, and biotechnology development. Site visitors will find an online catalogue of cultures organized alphabetically by class and by genus. UTEX provides an order form, as well as ordering and purchasing information. The site also provides a six-page list of literature references; links to other online algae collections; an image gallery; and notes on culture maintenance and growth media.

196

Battling golden algae: Results suggest preventative lake managment approaches  

E-print Network

in #23;#19;#18;#21; in the Pecos River, golden algae has since appeared in most of the #25;#21; major river systems throughout the state. Although it can exist in waters without being harmful, the algae caused major #28;sh kills in #28;ve of the state...?s river systems. As a result of their research, they discovered three approaches to lake management that seem to work in preventing and/or reducing golden algae blooms in Lake Granbury. ?We were able to e#15;ectively utilize pH manipu- lation...

Supercinski, Danielle

2011-01-01

197

Battling Golden Algae: Results suggest preventative lake management approaches  

E-print Network

in #23;#19;#18;#21; in the Pecos River, golden algae has since appeared in most of the #25;#21; major river systems throughout the state. Although it can exist in waters without being harmful, the algae caused major #28;sh kills in #28;ve of the state...?s river systems. As a result of their research, they discovered three approaches to lake management that seem to work in preventing and/or reducing golden algae blooms in Lake Granbury. ?We were able to e#15;ectively utilize pH manipu- lation...

Supercinski, Danielle

2011-01-01

198

PRELIMINARY SURVEY OF FUNGISTATIC PROPERTIES OF MARINE ALGAE  

PubMed Central

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

Welch, Ann Marie

1962-01-01

199

Plant & CellPhysiol. 14: 1081-1097 (1973) Photophosphorylation in intact algae: Effects of  

E-print Network

Plant & CellPhysiol. 14: 1081-1097 (1973) Photophosphorylation in intact algae: Effects alga Chlorella pyrenoidosa and of the blue-green alga Anacystis nidulans. A few measurements in extracts from intact cells of the green alga Chlorella in the early 1950's (3, 4), few workers measured

Govindjee

200

Cultivation of algae with indigenous species – Potentials for regional biofuel production  

Microsoft Academic Search

The massive need for sustainable energy has led to an increased interest in new energy resources, such as production of algae, for use as biofuel. There are advantages to using algae, for example, land use is much less than in terrestrial biofuel production, and several algae species can double their mass in 1day under optimized conditions. Most algae are phototrophs

M. Odlare; E. Nehrenheim; E. Thorin; M. Gavare; M. Grube

2011-01-01

201

Lateral Transfer and Recompartmentalization of Calvin Cycle Enzymes of Plants and Algae  

E-print Network

uptake of a cyanobacterium. Primary plastids, found in glauco- phytes, red algae, green algae, and plantsLateral Transfer and Recompartmentalization of Calvin Cycle Enzymes of Plants and Algae Matthew are not always found in algae with secondary plastids: there is evidence for multiple events of both lateral gene

Keeling, Patrick

202

Author's personal copy A novel ocean color index to detect oating algae in the global oceans  

E-print Network

Author's personal copy A novel ocean color index to detect oating algae in the global oceans Remote sensing Ocean color Climate data record Various types of oating algae have been reported in open ocean color index, namely the Floating Algae Index (FAI), is developed and used to detect oating algae

Meyers, Steven D.

203

Properties of phosphatases from green alga Scenedesmus incrassatulus Bahlin and blue-green alga Synechococcus aeruginosus Nag  

Microsoft Academic Search

Studies on phosphatases (acid and alkaline) inSynechococcus aeruginosus, a prokaryotic blue-green alga, andScenedesmus incrassatulus, an eukaryotic green alga under different conditions revealed that the acid phosphatase exhibited maximum activity to pH\\u000a 4·7 and 37°C in both the algae while alkaline phosphatase displayed greatest activity at 37·5°C and 10 pH inSynechococcus aeruginosus and at 10·6 pH and 37·5°C inScenedesmus incrassatulus. TheK

T R K Reddy; R Lakshminarayana

1988-01-01

204

Signal and Nutrient Exchange in the Interactions Between Soil Algae and Bacteria  

Microsoft Academic Search

\\u000a Microbial consortia of soil algae and prokaryotes have important functions in terrestrial ecosystems. Recent studies helped\\u000a delineate phylogenetic diversity of microbiota associated with soil algae. Some signals and nutrients exchanged between algae\\u000a and the associated bacteria were also identified. Both algae and bacteria appear to benefit from the interactions: algae derive\\u000a fixed nitrogen, vitamins, and hormones from their bacterial associates.

Max Teplitski; Sathish Rajamani

205

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 ...

206

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 ...

207

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...

208

Two new chamigranes from an hawaiian red alga, Laurencia cartilaginea  

Microsoft Academic Search

From the red alga Laurencia cartilaginea, six halogenated sesquiterpenes were isolated. Two new chamigranes, ma'ilione (5) and allo-isoobtusol (6) were identified by spectroscopic methods. Their cytotoxicity profiles are reported.

Elen G. Juagdan; Raju Kalidindi; Paul Scheuer

1997-01-01

209

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

ERIC Educational Resources Information Center

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)

Delpech, Roger

2001-01-01

210

Potential pharmacological applications of polyphenolic derivatives from marine brown algae.  

PubMed

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

Thomas, Noel Vinay; Kim, Se-Kwon

2011-11-01

211

21 CFR 73.185 - Haematococcus algae meal.  

Code of Federal Regulations, 2013 CFR

...Section 73.185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT...ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.185 Haematococcus algae...use in color additive mixtures for coloring foods. (b) Specifications....

2013-04-01

212

21 CFR 73.185 - Haematococcus algae meal.  

Code of Federal Regulations, 2012 CFR

...Section 73.185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT...ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.185 Haematococcus algae...use in color additive mixtures for coloring foods. (b) Specifications....

2012-04-01

213

Bicarbonate produced from carbon capture for algae culture.  

PubMed

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

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

2011-11-01

214

Application of synthetic biology in cyanobacteria and algae  

PubMed Central

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

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

2012-01-01

215

Algae Reefs in Shark Bay, Western Australia, Australia  

NASA Technical Reports Server (NTRS)

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.

1990-01-01

216

Partial identification and nutritional analysis of Kiribati algae  

Microsoft Academic Search

A chemical analysis of the edible algae from the island of Beru in Kiribati revealed it contained relatively high concentrations of Mg2+ and Ca2+ ions. A fair amount of protein and other minerals such as Na+, K+, Cu2+, Mn2+, Zn2+ and Fe2+ ions are also present in it. The scientific identification revealed that the algae are made of a mixture

M Maata; T Pickering; S Ali

217

Algae biodiesel has potential despite inconclusive results to date  

Microsoft Academic Search

A meta-analysis of several published life cycle assessments of algae-to-energy systems was developed to better understand the environmental implications of deploying this technology at large scales. Taken together, results from these six studies seemed largely inconclusive because of differences in modeling assumptions and system boundaries. To overcome this, the models were normalized using a generic pathway for cultivating algae in

Xiaowei Liu; Andres F. Clarens; Lisa M. Colosi

218

Effect of Epiphytic Algae on Photosynthetic Function of Potamogeton crispus  

Microsoft Academic Search

The effect of blooming epiphytic algae on the leaf traits and photosynthetic function of the submersed macrophyte Potamogeton crispus was investigated under different epiphytic conditions and nutrition levels. Epiphytic algae growth was promoted at a rate of 0.16 chl a ?g.cm.d on leaf surface area under eutrophic conditions (N: 1 mg.L; P: 0.1 mg-L) and at a rate of 0.004

Can Chen; Daqiang Yin; Bin Yu; Hankai Zhu

2007-01-01

219

Algas epífitas de Bajo Pepito, Isla Mujeres, Quintana Roo, México  

Microsoft Academic Search

Epiphytic algae from Bajo Pepito, Isla Mujeres, Quintana Roo, México. 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

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

220

Photobiological hydrogen production in green algae and photosynthetic bacteria  

SciTech Connect

We have shown that, under appropriate physiological conditions, certain freshwater and marine green algae are capable of splitting water to molecular hydrogen and oxygen in a sustained steady-state reaction. In these algae, the gaseous-fuel-producing reaction can be driven by light throughout the visible portion of the solar emission spectrum, including the long wavelength (red) 700-nm region. No external energy sources are required.

Greenbaum, E.

1986-01-01

221

Heavy Metals and Pesticides Analysis from Black Sea Algae  

Microsoft Academic Search

Our studies were focused on heavy metals (Cd, Cu, Zn, and Pb) and pesticides analysis from two different types of marine algae\\u000a in order to assess their capabilities to be used as raw material for pharmaceutical purposes without risks for human health.\\u000a The analysed algae, Cystoseira barbata and Ceramium rubrum, have been collected from Romanian Black Sea Coast in the

Simona Lupsor; Gabriela Stanciu; Dan Epure; Elisabeta Chirila

222

Algae culture for cattle feed and water purification. Final report  

SciTech Connect

The feasibility of algae growth on centrate from anaerobic digester effluent and the refeed of both effluent solids and the algae to feedlot cattle were investigated. The digester was operated with dirt feedlot manure. The study serves as a supplement for the work to design a utility sized digester for the City of Lamar to convert local feedlot manure into a fuel gas. The biogas produced would power the electrical generation plant already in service. Previous studies have established techniques of digester operation and the nutritional value for effluent solids as fed to cattle. The inclusion of a single-strain of algae, Chlorella pyrenidosa in the process was evaluated here for its capability (1) to be grown in both open and closed ponds of the discharge water from the solids separation part of the process, (2) to purify the discharge water, and (3) to act as a growth stimulant for cattle feed consumption and conversion when fed at a rate of 6 grams per head per day. Although it was found that the algae could be cultured and grown on the discharge water in the laboratory, the study was unable to show that algae could accomplish the other objectives successfully. However, the study yielded supplementary information useful to the overall process design of the utility plant. This was (1) measurement of undried digester solids fed to cattle in a silage finishing ration (without algae) at an economic value of $74.99 per dry ton based on nutritional qualities, (2) development of a centrate treatment system to decolorize and disinfect centrate to allow optimum algae growth, and (3) information on ionic and mass balances for the digestion system. It is the recommendation of this study that algae not be used in the process in the Lamar bioconversion plant.

Varani, F.T.; Schellenbach, S.; Veatch, M.; Grover, P.; Benemann, J.

1980-05-16

223

Marine Algae Membrane Phospholipids Study by High Resolution P NMR  

Microsoft Academic Search

Membrane phospholipids were extracted using a modified Folch, Lees and Sloane-Stanley method, from 21 different algae species covering three major divisions of the protista kingdom. In the modified method after chloroform\\/methanol (2:1 v\\/v) extraction and filtration, the solution was backwashed with K-EDTA, 0.6 M, instead of KCl, 1 M. Because algae samples are eavily loaded with cations that broaden NMR

Patricio Meneses; Nelson Navarro

1990-01-01

224

LIGHT-INDUCED EFFICIENCY AND PIGMENT ALTERATIONS IN RED ALGAE*  

E-print Network

The low photosynthetic efficiency of chlorophyll in freshly collected red algae, can, in the case of Porphyra perforata, P. nereocystis, and Porpkyridium cruentum, be inercased by growing the algae for 10 days in red or blue light. Exposure to darkness or to green light maintains the algae in their originally low efficiency with respect to chlorophyll, while retaining the high efficiency of phycobilins. Red- or blue-adapted algae are rapidly reversed by exposure to green light, the chlorophyll efficiency dropping to low values again in a few hours. This is assumed to account for the action spectrum of freshly gathered plants. Some pigment changes were observed, but not in the direction of "chromatic adaptation; " and the carotenoid pigments were not activated, even by blue light, but remained as photosynthetically inactive shading filters. The higher red algae (Florideae) did not show activation of chlorophyll by red or blue light. Chlorophyll a of freshly collected marine red algae sensitizes photosynthesis with an efficiency of about 0.04 molecule oxygen liberated per absorbed quantum.

C. S. Yocum; L. R. Blinks

1957-01-01

225

Extraction of mercury from ground-water using immobilized algae  

SciTech Connect

Bio-recovery Systems Inc., conducted a project under the Emerging Technology portion of the United States Environmental Protection Agency's (EPAs) Superfund Innovative Technology Evaluation (SITE) Program to evaluate the ability of immobilized algae to absorb mercury from contaminated groundwater in laboratory studies and pilot-scale field tests. Algae biomass was incorporated in a permeable polymeric matrix. The product, AlgaSORB, packed into absorption columns, exhibited excellent flow characteristics, and functioned as a 'biological' ion exchange resin. A sequence of eleven laboratory tests demonstrated the ability of the product to absorb mercury from groundwater that contained high levels of total dissolved solids and hard water components. However, use of a single AlgaSORB preparation yielded non-repeatable results with samples collected at different times of the year. The strategy of extracting the groundwater through two columns containing different times of the year. The strategy of extracting the groundwater through two columns containing different preparations of AlgaSORB was developed and proved successful in laboratory and pilot-scale field tests. Field test results indicate that AlgaSORB could be economically competitive with ion exchange resins for removal of mercury, with the advantage that hardness and other dissolved solids do not appear to compete with heavy metals for binding capacity. (Copyright (c) 1991--Air and Waste Management Association.)

Barkley, N.P.

1991-01-01

226

An overview of algae biofuel production and potential environmental impact.  

PubMed

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

Menetrez, Marc Y

2012-07-01

227

Development of Green Fuels From Algae - The University of Tulsa  

SciTech Connect

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 â??green fuelsâ? 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 PIâ??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.

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

2012-12-03

228

Phosphorus-Limited Growth of a Green Alga and a Blue-Green Alga  

PubMed Central

The phosphorus-limited growth kinetics of the chlorophyte Scenedesmus quadricauda and the cyanophyte Synechococcus Nägeli were studied by using batch and continuous culturing techniques. The steady-state phosphate transport capability and the phosphorus storage capacity is higher in S. Nägeli than in S. quadricauda. Synechococcus Nägeli can also deplete phosphate to much lower levels than can S. quadricauda. These results, along with their morphological characteristics, were used to construct partial physiological profiles for each organism. The profiles indicate that this unicellular cyanophyte (cyanobacterium) is better suited for growth in phosphorus-limited oligotrophic niches than is this chlorophyte (green alga). PMID:16345896

Lang, Douglas S.; Brown, Edward J.

1981-01-01

229

AlgaGEM - a genome-scale metabolic reconstruction of algae based on the Chlamydomonas reinhardtii genome  

PubMed Central

Background Microalgae have the potential to deliver biofuels without the associated competition for land resources. In order to realise the rates and titres necessary for commercial production, however, system-level metabolic engineering will be required. Genome scale metabolic reconstructions have revolutionized microbial metabolic engineering and are used routinely for in silico analysis and design. While genome scale metabolic reconstructions have been developed for many prokaryotes and model eukaryotes, the application to less well characterized eukaryotes such as algae is challenging not at least due to a lack of compartmentalization data. Results We have developed a genome-scale metabolic network model (named AlgaGEM) covering the metabolism for a compartmentalized algae cell based on the Chlamydomonas reinhardtii genome. AlgaGEM is a comprehensive literature-based genome scale metabolic reconstruction that accounts for the functions of 866 unique ORFs, 1862 metabolites, 2249 gene-enzyme-reaction-association entries, and 1725 unique reactions. The reconstruction was compartmentalized into the cytoplasm, mitochondrion, plastid and microbody using available data for algae complemented with compartmentalisation data for Arabidopsis thaliana. AlgaGEM describes a functional primary metabolism of Chlamydomonas and significantly predicts distinct algal behaviours such as the catabolism or secretion rather than recycling of phosphoglycolate in photorespiration. AlgaGEM was validated through the simulation of growth and algae metabolic functions inferred from literature. Using efficient resource utilisation as the optimality criterion, AlgaGEM predicted observed metabolic effects under autotrophic, heterotrophic and mixotrophic conditions. AlgaGEM predicts increased hydrogen production when cyclic electron flow is disrupted as seen in a high producing mutant derived from mutational studies. The model also predicted the physiological pathway for H2 production and identified new targets to further improve H2 yield. Conclusions AlgaGEM is a viable and comprehensive framework for in silico functional analysis and can be used to derive new, non-trivial hypotheses for exploring this metabolically versatile organism. Flux balance analysis can be used to identify bottlenecks and new targets to metabolically engineer microalgae for production of biofuels. PMID:22369158

2011-01-01

230

Comparative Transcriptome Analysis of Four Prymnesiophyte Algae  

PubMed Central

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

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

2014-01-01

231

Is the Future Really in Algae?  

NASA Technical Reports Server (NTRS)

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.

Trent, Jonathan

2011-01-01

232

Microfluidic one-way streets for algae  

NASA Astrophysics Data System (ADS)

Controlling locomotion and transport of microorganisms is a key challenge in the development of future biotechnological applications. Here, we demonstrate the use of optimized microfluidic ratchets to rectify the mean swimming direction in suspensions of the unicellular green alga Chlamydomonas reinhardtii, which is a promising candidate for the photosynthetic production of hydrogen. To assess the potential of microfluidic barriers for the manipulation of algal swimming, we studied first the scattering of individual C. reinhardtii from solid boundaries. High-speed imaging reveals the surprising result that these quasi-spherical ``puller''-type microswimmers primarily interact with surfaces via direct flagellar contact, whereas hydrodynamic effects play a subordinate role. A minimal theoretical model, based on run-and-turn motion and the experimentally measured surface-scattering law, predicts the existence of optimal wedge-shaped ratchets that maximize rectification of initially uniform suspensions. We confirm this prediction in experimental measurements with different geometries. Since the mechano-elastic properties of eukaryotic flagella are conserved across many genera, we expect that our results and methods are applicable to a broad class of biflagellate microorganisms.

Dunkel, Jorn; Kantsler, Vasily; Polin, Marco; Goldstein, Raymond E.

2012-02-01

233

Algae 2013, 28(4): 343-354 http://dx.doi.org/10.4490/algae.2013.28.4.343  

E-print Network

Algae 2013, 28(4): 343-354 http://dx.doi.org/10.4490/algae.2013.28.4.343 Open Access Research Article Copyright © The Korean Society of Phycology 343 http://e-algae.kr pISSN: 1226-2617 eISSN: 2093; harmful algal bloom; ingestion; protist; red tide INTRODUCTION Phototrophic dinoflagellates are ubiquitous

Jeong, Hae Jin

234

The potential for using cyanobacteria (blue-green algae) and algae in the biological control of plant pathogenic bacteria and fungi  

Microsoft Academic Search

Cyanobacteria (blue-green algae) and eukaryote algae occur in freshwater, marine, and terrestrial (soil) habitats. In fact, these microorganisms comprise most of the world's biomass. Although the cyanobacteria are mostly photoautotrophic, some are facultative heterotrophs, capable of growing on certain substrates in darkness. Also, some are non-phototrophic and hence, are obligate heterotrophs. A number of cyanobacteria and eukaryote algae, particularly macroalgae,

Martin M. Kulik

1995-01-01

235

Plasticity predicts evolution in a marine alga  

PubMed Central

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

Schaum, C. Elisa; Collins, Sinead

2014-01-01

236

Plasticity predicts evolution in a marine alga.  

PubMed

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

Schaum, C Elisa; Collins, Sinéad

2014-10-22

237

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

DOEpatents

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.

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

2012-11-06

238

Inorganic carbon acquisition by eukaryotic algae: four current questions.  

PubMed

The phylogenetically and morphologically diverse eukaryotic algae are typically oxygenic photolithotrophs. They have a diversity of incompletely understood mechanisms of inorganic carbon acquisition: this article reviews four areas where investigations continue. The first topic is diffusive CO(2) entry. Most eukaryotic algae, like all cyanobacteria, have inorganic carbon concentrating mechanisms (CCMs). The ancestral condition was presumably the absence of a CCM, i.e. diffusive CO(2) entry, as found in a small minority of eukaryotic algae today; however, it is likely that, as is found in several cases, this condition is due to a loss of a CCM. There are a number of algae which are in various respects intermediate between diffusive CO(2) entry and occurrence of a CCM: further study is needed on this aspect. A second topic is the nature of cyanelles and their role in inorganic carbon assimilation. The cyanelles (plastids) of the euglyphid amoeba Paulinella have been acquired relatively recently by endosymbiosis with genetic integration of an ?-cyanobacterium with a Form 1A Rubisco. The ?-carboxysomes in the cyanelles are presumably involved in a CCM, but further investigation is needed.Also called cyanelles are the plastids of glaucocystophycean algae, but is it now clear that these were derived from the ?-cyanobacterial ancestor of all plastids other than that of Paulinella. The resemblances of the central body of the cyanelles of glaucocystophycean algae to carboxysomes may not reflect derivation from cyanobacterial ?-carboxysomes; although it is clear that these algae have CCMs but these are now well characterized. The other two topics concern CCMs in other eukaryotic algae; these CCMs arose polyphyletically and independently of the cyanobacterial CCMs. It is generally believed that eukaryotic algal, like cyanobacterial, CCMs are based on active transport of an inorganic carbon species and/or protons, and they have C(3) biochemistry. This is the case for the organism considered as the third topic, i.e. Chlamydomonas reinhardtii, the eukaryotic alga with the best understood CCM. This CCM involves HCO(3)(-) conversion to CO(2) in the thylakoid lumen so the external inorganic carbon must cross four membranes in series with a final CO(2) effux from the thylakoid. More remains to be investigated about this CCM. The final topic is that of the occurrence of C(4)-like metabolism in the CCMs of marine diatoms. Different conclusions have been reached depending on the organism investigated and the techniques used, and several aspects require further study. PMID:20524069

Raven, John A

2010-11-01

239

Anti-Phytopathogenic Activities of Macro-Algae Extracts  

PubMed Central

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

Jimenez, Edra; Dorta, Fernando; Medina, Cristian; Ramirez, Alberto; Ramirez, Ingrid; Pena-Cortes, Hugo

2011-01-01

240

Extraction of mercury from groundwater using immobilized algae  

SciTech Connect

Bio-Recovery Systems, Inc. conducted a project under the Emerging Technology portion of the United States Environmental Protection Agency's (EPAs) Superfund Innovative Technology Evaluation (SITE) Program to evaluate the ability of immobilized algae to adsorb mercury from contaminated groundwater in laboratory studies and pilot-scale field tests. Algal biomass was incorporated in a permeable polymeric matrix. The product, AlgaSORB, packed into adsorption columns, exhibited excellent flow characteristics, and functioned as a biological ion exchange resin. A sequence of eleven laboratory tests demonstrated the ability of this product to adsorb mercury from groundwater that contained high levels of total dissolved solids and hard water components. However, use of a single AlgaSORB preparation yielded nonrepeatable results with samples collected at different times of the year. The strategy of sequentially extracting the groundwater through two columns containing different preparations of AlgaSORB was developed and proved successful in laboratory and pilot-scale field tests. Field test results indicate that AlgaSORB could be economically competitive with ion exchange resins for removal of mercury, with the advantage that hardness and other dissolved solids do not appear to compete with heavy metals for binding capacity.

Barkley, N.P. (Environmental Protection Agency, Cincinnati, OH (United States))

1991-10-01

241

Visualization of oxygen distribution patterns caused by coral and algae.  

PubMed

Planar optodes were used to visualize oxygen distribution patterns associated with a coral reef associated green algae (Chaetomorpha sp.) and a hermatypic coral (Favia sp.) separately, as standalone organisms, and placed in close proximity mimicking coral-algal interactions. Oxygen patterns were assessed in light and dark conditions and under varying flow regimes. The images show discrete high oxygen concentration regions above the organisms during lighted periods and low oxygen in the dark. Size and orientation of these areas were dependent on flow regime. For corals and algae in close proximity the 2D optodes show areas of extremely low oxygen concentration at the interaction interfaces under both dark (18.4 ± 7.7 µmol O2 L(- 1)) and daylight (97.9 ± 27.5 µmol O2 L(- 1)) conditions. These images present the first two-dimensional visualization of oxygen gradients generated by benthic reef algae and corals under varying flow conditions and provide a 2D depiction of previously observed hypoxic zones at coral algae interfaces. This approach allows for visualization of locally confined, distinctive alterations of oxygen concentrations facilitated by benthic organisms and provides compelling evidence for hypoxic conditions at coral-algae interaction zones. PMID:23882443

Haas, Andreas F; Gregg, Allison K; Smith, Jennifer E; Abieri, Maria L; Hatay, Mark; Rohwer, Forest

2013-01-01

242

Development and characteristics of an adhesion bioassay for ectocarpoid algae.  

PubMed

Species of filamentous brown algae in the family Ectocarpaceae are significant members of fouling communities. However, there are few systematic studies on the influence of surface physico-chemical properties on their adhesion. In the present paper the development of a novel, laboratory-based adhesion bioassay for ectocarpoid algae, at an appropriate scale for the screening of sets of experimental samples in well-replicated and controlled experiments is described. The assays are based on the colonization of surfaces from a starting inoculum consisting of multicellular filaments obtained by blending the cultured alga Ectocarpus crouaniorum. The adhesion strength of the biomass after 14 days growth was assessed by applying a hydrodynamic shear stress. Results from adhesion tests on a set of standard surfaces showed that E. crouaniorum adhered more weakly to the amphiphilic Intersleek® 900 than to the more hydrophobic Intersleek® 700 and Silastic® T2 coatings. Adhesion to hydrophilic glass was also weak. Similar results were obtained for other cultivated species of Ectocarpus but differed from those obtained with the related ectocarpoid species Hincksia secunda. The response of the ectocarpoid algae to the surfaces was also compared to that for the green alga, Ulva. PMID:22146003

Evariste, Emmanuelle; Gachon, Claire M M; Callow, Maureen E; Callow, James A

2012-01-01

243

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

DOEpatents

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.

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

1997-08-26

244

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

DOEpatents

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.

Dunahay, Terri Goodman (2710 Arbor Glen Pl., Boulder, CO 80304); Roessler, Paul G. (15905 Ellsworth Pl., Golden, CO 80401); Jarvis, Eric E. (3720 Smuggler Pl., Boulder, CO 80303)

1997-01-01

245

Sustainability of algae derived biodiesel: a mass balance approach.  

PubMed

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

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

2011-01-01

246

AlgaePath: comprehensive analysis of metabolic pathways using transcript abundance data from next-generation sequencing in green algae  

PubMed Central

Background Algae are important non-vascular plants that have many research applications, including high species diversity, biofuel sources, and adsorption of heavy metals and, following processing, are used as ingredients in health supplements. The increasing availability of next-generation sequencing (NGS) data for algae genomes and transcriptomes has made the development of an integrated resource for retrieving gene expression data and metabolic pathway essential for functional analysis and systems biology. In a currently available resource, gene expression profiles and biological pathways are displayed separately, making it impossible to easily search current databases to identify the cellular response mechanisms. Therefore, in this work the novel AlgaePath database was developed to retrieve transcript abundance profiles efficiently under various conditions in numerous metabolic pathways. Description AlgaePath is a web-based database that integrates gene information, biological pathways, and NGS datasets for the green algae Chlamydomonas reinhardtii and Neodesmus sp. UTEX 2219–4. Users can search this database to identify transcript abundance profiles and pathway information using five query pages (Gene Search, Pathway Search, Differentially Expressed Genes (DEGs) Search, Gene Group Analysis, and Co-expression Analysis). The transcript abundance data of 45 and four samples from C. reinhardtii and Neodesmus sp. UTEX 2219–4, respectively, can be obtained directly on pathway maps. Genes that are differentially expressed between two conditions can be identified using Folds Search. The Gene Group Analysis page includes a pathway enrichment analysis, and can be used to easily compare the transcript abundance profiles of functionally related genes on a map. Finally, the Co-expression Analysis page can be used to search for co-expressed transcripts of a target gene. The results of the searches will provide a valuable reference for designing further experiments and for elucidating critical mechanisms from high-throughput data. Conclusions AlgaePath is an effective interface that can be used to clarify the transcript response mechanisms in different metabolic pathways under various conditions. Importantly, AlgaePath can be mined to identify critical mechanisms based on high-throughput sequencing. To our knowledge, AlgaePath is the most comprehensive resource for integrating numerous databases and analysis tools in algae. The system can be accessed freely online at http://algaepath.itps.ncku.edu.tw. PMID:24628857

2014-01-01

247

Benefits of using algae as natural sources of functional ingredients.  

PubMed

Algae have been suggested as a potential source of bioactive compounds to be used in the food and pharmaceutical industries. With the strong development of functional foods as a method to improve or maintain health, the exploration of new compounds with real health effects is now an intense field of research. The potential use of algae as source of functional food ingredients, such as lipids, proteins, polysaccharides, phenolics, carotenoids, etc., is presented, together with the different possibilities of improving valuable metabolites production either using the tools and the knowledge provided by marine biotechnology or improving the different factors involved in the production on a large scale of such metabolites. The bio-refinery concept is also presented as a way to improve the efficient use of algae biomass while favouring process sustainability. PMID:23339029

Ibañez, Elena; Cifuentes, Alejandro

2013-03-15

248

Enhanced lipid extraction from algae using free nitrous acid pretreatment.  

PubMed

Lipid extraction has been identified as a major bottleneck for large-scale algal biodiesel production. In this work free nitrous acid (FNA) is presented as an effective and low cost pretreatment to enhance lipid recovery from algae. Two batch tests, with a range of FNA additions, were conducted to disrupt algal cells prior to lipid extraction by organic solvents. Total accessible lipid content was quantified by the Bligh and Dyer method, and was found to increase with pretreatment time (up to 48 h) and FNA concentration (up to 2.19 mg HNO2-N/L). Hexane extraction was used to study industrially accessible lipids. The mass transfer coefficient (k) for lipid extraction using hexane from algae treated with 2.19 mg HNO2-N/L FNA was found to be dramatically higher than for extraction from untreated algae. Consistent with extraction results, cell disruption analysis indicated the disruption of the cell membrane barrier. PMID:24632439

Bai, Xue; Naghdi, Forough Ghasemi; Ye, Liu; Lant, Paul; Pratt, Steven

2014-05-01

249

Application of intact algae to the biophotolysis problem  

SciTech Connect

The utilization of intact algae for the simultaneous light-activated production of molecular hydrogen and oxygen is discussed. Experimental data on the long-term stability and endurance of hydrogen and oxygen photoproduction by anaerobically adapted Chlamydomonas reinhardtii is presented. The general conclusion that can be derived from this work is that Chlamydomonas (and probably other microscopic eukaryotic algae) are extremely rugged organisms with respect to the biophotolysis problem. Working with a sample of wild-type Chlamydomonas reinhardtii, the simultaneous photoproduction of hydrogen and oxygen was observed for approximately 100 h. The bleached algae were then removed from the reactor and used as the inoculum in fresh growth medium. These second-generation cells regreened and were able to photoproduce hydrogen and oxygen initially at ten times the rate of the first generation cells and had better survivability characteristics as indicated by their chlorophyll content after 200 h.

Greenbaum, E.

1982-01-01

250

Aragonitic Pennsylvanian phylloid algae from New Mexico: The missing link  

SciTech Connect

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.

Kirkland, B.L.; Moore, C.H. Jr. (Louisiana State Univ., Baton Rouge (United States)); Dickson, J.A.D. (Univ. of Cambridge (United Kingdom))

1991-03-01

251

Complex phylogeographic patterns in the freshwater alga Synura provide new insights into ubiquity vs. endemism  

E-print Network

Complex phylogeographic patterns in the freshwater alga Synura provide new insights into ubiquity The global distribution, abundance, and diversity of microscopic freshwater algae demonstrate an ability with observations that many freshwater microalgal taxa possess true biogeographies. Here, using a concatenated

Wolfe, Alexander P.

252

Micro-Raman Spectroscopy of Algae: Composition Analysis and Fluorescence Background Behavior  

E-print Network

ARTICLE Micro-Raman Spectroscopy of Algae: Composition Analysis and Fluorescence Background performed using Stokes Raman scattering for compositional analysis of algae. Two algal species, Chlorella were considered to be candidates for biofuel production. Raman signals due to storage lipid

253

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

NASA Technical Reports Server (NTRS)

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.

Meyer, C.

1979-01-01

254

Algae as promising organisms for environment and health  

PubMed Central

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

2011-01-01

255

Chemical composition of the green alga Codium Divaricatum Holmes.  

PubMed

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

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

2010-12-01

256

Algae as promising organisms for environment and health.  

PubMed

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

Shalaby, Emad A

2011-09-01

257

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

PubMed Central

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

Samek, Ota; Jonas, Alexandr; Pilat, Zdenek; Zemanek, Pavel; Nedbal, Ladislav; Triska, Jan; Kotas, Petr; Trtilek, Martin

2010-01-01

258

Separating ITCZ- and ENSO-related rainfall changes in the Galápagos over the last 3 kyr using D/H ratios of multiple lipid biomarkers  

NASA Astrophysics Data System (ADS)

We present a 3000-yr rainfall reconstruction from the Galápagos 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 Galápagos Islands is governed by movements of the Intertropical Convergence Zone (ITCZ) and the El Niño-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 Niño events. We use these proxies to infer changes in mean rainfall and El Niño-related rainfall over the past 3000 yr. During periods in which the inferred change in El Niño-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 Niño- 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 Niño 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.

Atwood, Alyssa R.; Sachs, Julian P.

2014-10-01

259

Algae utilization in assessment of the large Turawa Lake (Poland) pollution with heavy metals  

Microsoft Academic Search

This investigation was undertaken to determine the applicability of algae for the assessment of contamination level of water reservoirs with heavy metals. The alga Spirogyra sp. collected in the littoral zone of the Large Turawa Lake (artificial lake in Southern Poland) was used for the study. The concentrations of heavy metals accumulated in the alga inhabiting a flow-through water basin

Ma?gorzata Rajfur; Andrzej K?os; Maria Wac?awek

2011-01-01

260

BIOCHIMICA ET BIOPHYSICA ACTA 213 ACTION OF HYDROXYLAMINE IN THE RED ALGA PORPHYRIDIUM  

E-print Network

BIOCHIMICA ET BIOPHYSICA ACTA 213 BBA 46182 ACTION OF HYDROXYLAMINE IN THE RED ALGA PORPHYRIDIUM CR and fluorescence transient studies, made with the intact cells of red alga Porphyridium cruentum, suggest earlier with spinach chloroplasts and green alga Chlorella by other workers. Fluorescence transient data

Govindjee

261

Photoprotection in the brown alga Macrocystis pyrifera: Evolutionary implications Ernesto Garcia-Mendoza a,  

E-print Network

Photoprotection in the brown alga Macrocystis pyrifera: Evolutionary implications Ernesto Garcia xxxx Keywords: Brown algae Evolution Macrocystis pyrifera Non-photochemical quenching Photoprotection-photochemical quenching, NPQ) in the brown alga Macrocystis pyrifera with that of Ficus sp., a higher plant to examine

Govindjee

262

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

ERIC Educational Resources Information Center

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…

Blackwell, Will H.; Powell, Martha J.

1995-01-01

263

INTRODUCTION Cryptomonad algae are postulated to be a chimaera of two  

E-print Network

INTRODUCTION Cryptomonad algae are postulated to be a chimaera of two different eukaryotic cells incorporating cryptomonad endosymbiont gene sequences ally them loosely with red algae (Douglas et al., 1991a that the endosymbiont was an early evolutionary intermediate that pre-dates the red algae (Cavalier-Smith, 1992

McFadden, Geoff

264

One-Two-Three Punch Clobbers Toxic Algae, Restores Fremont Lake  

E-print Network

One-Two-Three Punch Clobbers Toxic Algae, Restores Fremont Lake Final Report Fremont Lake #20 Water-two-three punch to knockout toxic algae and restore water quality in Nebraska's numerous sandpit lakes. "It seems to help rid the too-often toxic algae prone Fremont State Lakes of the oily green scum that can close them

Nebraska-Lincoln, University of

265

HOLARCTIC ECOLOGY 4: 201-207. Copenhagen 1981 Microcommunities of algae on a Sphagnum mat  

E-print Network

HOLARCTIC ECOLOGY 4: 201-207. Copenhagen 1981 Microcommunities of algae on a Sphagnum mat Celia A. Hooper Hooper, C, A, 1981, Microcommunities of algae on a Sphagnum mat, - Holarct, Ecol, 4: 201 and nutrient parameters, with lower, moister plots having more algae, higher algal diver- sity, and lower

Notre Dame, University of

266

428 BIOCHIMICAET BIOPHYSICAACTA pH CONTROL OF THE CHLOROPHYLL a FLUORESCENCE IN ALGAE  

E-print Network

428 BIOCHIMICAET BIOPHYSICAACTA BBA 46126 pH CONTROL OF THE CHLOROPHYLL a FLUORESCENCE IN ALGAE on the "slow" (min) time course of Chlorophyll a fluorescence yield in the green alga Chlorella pyrenoidosa and in the blue-green alga Anacystis nidulans. In Chlorella, the decay of fluorescence yield, in the I- to 5-rain

Govindjee

267

Observations on the measurement of total antimony and antimony species in algae, plant and animal tissuesw  

E-print Network

Observations on the measurement of total antimony and antimony species in algae, plant and animal of total antimony and antimony speciation in algae, plant and animal tissues. Digestion with nitric acid.g. some plants and algae, the addition of tetrafluorboric acid is required to dissolve silica as some

Canberra, University of

268

Investigation of Flow Characteristics in an Airlift-Driven Raceway Reactor for Algae Cultivation  

E-print Network

Investigation of Flow Characteristics in an Airlift-Driven Raceway Reactor for Algae Cultivation are the most common choice for outdoor algae cultivation due to their low cost relative to enclosed. Algae require adequate mixing in order to maximize exposure to essential nutrients for growth

269

Energy From Algae Using Microbial Fuel Cells Sharon B. Velasquez-Orta,1  

E-print Network

ARTICLE Energy From Algae Using Microbial Fuel Cells Sharon B. Velasquez-Orta,1 Tom P. Curtis,1 with the two algae (as powders), obtaining differences in energy recovery, degradation efficiency, and power to the type of bioprocess used. These results demonstrate that algae can in principle, be used as a renewable

270

Photosynthetic and growth responses of three freshwater algae to phosphorus limitation and daylength  

E-print Network

Photosynthetic and growth responses of three freshwater algae to phosphorus limitation., green alga Sphaerocystis schroeteri and cyanobacterium Phormidium luridum, were grown under contrasting of the green alga S. schroeteri decreased the most (ca. sixfold) under P limitation compared with the other two

Bossard, Peter

271

The Seattle Times: Nation & World: Algae gives professor a taste of immortality Home delivery  

E-print Network

The Seattle Times: Nation & World: Algae gives professor a taste of immortality Home delivery, 2005 - Page updated at 12:00 AM Algae gives professor a taste of immortality By David A. Fahrenthold The Washington Post E-mail article Print view Search Most e-mailed Most read RSS Sometimes, algae can

Jeong, Hae Jin

272

HoustonChronicle.com -Tiny honor a big deal for algae scientist HoustonChronicle.  

E-print Network

HoustonChronicle.com - Tiny honor a big deal for algae scientist HoustonChronicle. com Section-mail this story June 18, 2005, 5:48PM Tiny honor a big deal for algae scientist By DAVID A. FAHRENTHOLD Washington Post Sometimes, algae can be the highest form of flattery. ADVERTISEMENTSo it was for Diane K. Stoecker

Jeong, Hae Jin

273

Effect of non-ageing and ageing ceria nanoparticles suspensions on fresh water micro-algae  

E-print Network

Effect of non-ageing and ageing ceria nanoparticles suspensions on fresh water micro-algae Manier nanoparticles suspensions toward fresh water micro-algae Manier Nicolas, Bado Anne, Resve Amélie, Delalain algae. The ecotoxic effects were investigated using both non-aging (freshly prepared) or aging

Boyer, Edmond

274

THE POTENTIAL FOR MICRO-ALGAE AND OTHER "MICRO-CROPS" TO PRODUCE  

E-print Network

THE POTENTIAL FOR MICRO-ALGAE AND OTHER "MICRO-CROPS" TO PRODUCE SUSTAINABLE BIOFUELS A REVIEW INTRODUCTION Biofuel derived from algae and other micro-crops has been proposed as an environmentally benign model systems of algae-based biofuel production, exploring potential economic costs and environmental

Edwards, Paul N.

275

Climate implications of algae-based bioenergy systems Andres Clarens, PhD  

E-print Network

priorities. This is an especially challenging problem for algae-based biofuels because production pathways for the anticipated burdens of algae biofuels production might be. Second, I will discuss a novel methodClimate implications of algae-based bioenergy systems Andres Clarens, PhD Assistant Professor Civil

Walter, M.Todd

276

1128 volume 27 number 12 december 2009 nature biotechnology square meter per day of algae containing  

E-print Network

, such as triglycerides from algae or cellulosic biomass from higher plants, as feedstocks for biofuel production summarizing this work6, we concluded that algae might be a viable source of biofuels if--among other things1128 volume 27 number 12 december 2009 nature biotechnology square meter per day of algae

Cai, Long

277

Life-Cycle Greenhouse Gas and Energy Analyses of Algae Biofuels Production  

E-print Network

Life-Cycle Greenhouse Gas and Energy Analyses of Algae Biofuels Production Transportation Energy The Issue Algae biofuels directly address the Energy Commission's Public Interest Energy Research the sustainability of algae biofuels suggests that the lifecycle performance of these fuels is a critical

278

FAS4XXX: BIOLOGY AND ECOLOGY OF ALGAE Instructor: Professor Edward Phlips  

E-print Network

applications of algae in biotechnology, such as the production of food, chemicals and biofuels. CourseFAS4XXX: BIOLOGY AND ECOLOGY OF ALGAE Instructor: Professor Edward Phlips Main Office: Program-mail: phlips@ufl.edu Office Hours: 2-4 PM Thursdays Course Description: Biology and ecology of algae in aquatic

Hill, Jeffrey E.

279

Algae as a sustainable energy source for biofuel production in Iran: A case study  

Microsoft Academic Search

Algae can be converted directly into energy, such as biodiesel, bioethanol and biomethanol and therefore can be a source of renewable energy. There is a growing interest for biodiesel production from algae because of its higher yield non-edible oil production and its fast growth that does not compete for land with food production. About 50% of algae weight is oil

Gholamhassan Najafi; Barat Ghobadian; Talal F. Yusaf

2011-01-01

280

Optimal engineered algae composition for the integrated simultaneous production of bioethanol  

E-print Network

of biofuels and meet the government policies. The use of algae as energy feedstock is not new as it can1 Optimal engineered algae composition for the integrated simultaneous production of bioethanol of the algae for the simultaneous production of bioethanol and biodiesel. We consider two alternative

Grossmann, Ignacio E.

281

Biomass from Cyanobacteria:Opportunities for the Proposed Algae Biotechnology and Biofuels  

E-print Network

Biomass from Cyanobacteria:Opportunities for the Proposed Algae Biotechnology and Biofuels CLOSED DUE TO ALGAE BLOOM AND GENERAL ADVISORY REMAINS FOR HILLS CREEK RESERVOIR August 2, 2002 Larison. For the entire Reservoir, one should avoid high con centrations of blue-green algae both on the water surface

Tullos, Desiree

282

Optical microplates for high-throughput screening of photosynthesis in lipid-producing algae{,  

E-print Network

-producing algae of interest in 2nd generation biofuels. By conducting 96 experiments in parallel, photoirradianceOptical microplates for high-throughput screening of photosynthesis in lipid- producing algae the study of photosynthesis in algae. Societal challenges in energy sustainability have renewed interest

Basu, Amar S.

283

Effectiveness of algae in the treatment of a wood-based pulp and paper industry wastewater  

Microsoft Academic Search

In this study, the ability of algae to treat a wood-based pulp and paper industry wastewater was investigated. Tests were performed in batch reactors seeded with a mixed culture of algae. Under different lighting and initial wastewater strength conditions, changes in COD, AOX and color contents of reactors were followed with time. Algae were found to remove up to 58%

Esra Tarlan; Filiz B. Dilek; Ulku Yetis

2002-01-01

284

Ecophysiological performance of an urban strain of the aeroterrestrial green alga Klebsormidium sp. (Klebsormidiales, Klebsormidiophyceae)  

Microsoft Academic Search

Aeroterrestrial green algae are among the most ubiquitous members of the microbial flora colonizing aerial surfaces. Filamentous green algae, in particular, produce large populations in several natural and artificial habitats. In recent years it has been shown that the bases of the walls of urban environments are frequently colonized by filamentous green algae. However, information concerning the physiology of these

Ulf Karsten; Fabio Rindi

2010-01-01

285

J. Phycol. 39, 259267 (2003) THE MESOZOIC RADIATION OF EUKARYOTIC ALGAE  

E-print Network

in the evolution of eukaryotic algae that gave rise to red and green photoautotrophic lin- eages. In Paleozoic and chlorarachniophytes), but both contain relatively few species. In the red lineage, the red algae per se (Rhodophyta259 J. Phycol. 39, 259­267 (2003) MINIREVIEW THE MESOZOIC RADIATION OF EUKARYOTIC ALGAE

Falkowski, Paul G.

286

Fall 2012 / LAKELINE 33 Golden Algae & the Health of Okla. Lakes  

E-print Network

the ecology and toxicology of golden algae in Lake Texoma, an impoundment of the Red and Washita RiversFall 2012 / LAKELINE 33 Golden Algae & the Health of Okla. Lakes David Hambright HABs Introduction T he golden alga Prymnesium parvum is a toxigenic marine haptophyte that now occurs in and is prevalent

Hambright, K. David

287

Toward Systems Biology in Brown Algae to Explore Acclimation and Adaptation to the Shore Environment  

E-print Network

Toward Systems Biology in Brown Algae to Explore Acclimation and Adaptation to the Shore,2 Catherine Boyen,1,2 and Anne Siegel4,5 Abstract Brown algae belong to a phylogenetic lineage distantly siliculosus as a model organism for brown algae has represented a framework in which several omics techniques

Paris-Sud XI, Université de

288

Red Algae Respond to Waves: Morphological and Mechanical Variation in Mastocarpus papillatus Along  

E-print Network

Red Algae Respond to Waves: Morphological and Mechanical Variation in Mastocarpus papillatus Along Grove, California, 93950 Abstract. Intertidal algae are exposed to the potentially severe drag forces generated by crashing waves, and several species of brown algae respond, in part, by varying the strength

Denny, Mark

289

PHYSIOLOGICAL PERFORMANCE OF INTERTIDAL CORALLINE ALGAE DURING A SIMULATED TIDAL CYCLE1  

E-print Network

PHYSIOLOGICAL PERFORMANCE OF INTERTIDAL CORALLINE ALGAE DURING A SIMULATED TIDAL CYCLE1 Rebecca J, Lobban and Harrison 1997, Helmuth and Hofmann 2001). During high tide, intertidal algae are underwater algae may be emerged and exposed to increased light stress, elevated air tem- peratures, and increased

Martone, Patrick T.

290

PHYLOGENETIC DIVERSITY OF TRENTEPOHLIALEAN ALGAE ASSOCIATED WITH LICHEN-FORMING FUNGI1  

E-print Network

PHYLOGENETIC DIVERSITY OF TRENTEPOHLIALEAN ALGAE ASSOCIATED WITH LICHEN-FORMING FUNGI1 Matthew P 60605-2496, USA Nearly one-fourth of the lichen-forming fungi asso- ciate with trentepohlialean algae algae has provided a phy- logenetic context within which questions regarding the lichenization

291

Hierarchical Silica Nanostructures Inspired by Diatom Algae Yield Superior Deformability, Toughness, and Strength  

E-print Network

Hierarchical Silica Nanostructures Inspired by Diatom Algae Yield Superior Deformability, Toughness algae that is mainly composed of amorphous silica, which features a hierarchical structure that ranges in diatom algae as a basis to study a bioinspired nanoporous material implemented in crystalline silica. We

Buehler, Markus J.

292

Phylogeny and Nucleomorph Karyotype Diversity of Chlorarachniophyte Algae TIA D. SILVER,a,1  

E-print Network

Phylogeny and Nucleomorph Karyotype Diversity of Chlorarachniophyte Algae TIA D. SILVER,a,1 SAYAKA/or reticulopod-forming marine algae with chlorophyll a- and b-containing plastids of secondary endosymbiotic. THE chlorarachniophytes are an enigmatic group of unicellular marine algae with diverse morphologies and a widespread

Archibald, John

293

Kalinella bambusicola gen. et sp. nov. (Trebouxiophyceae, Chlorophyta), a novel coccoid Chlorella-like subaerial alga  

E-print Network

-like subaerial alga from Southeast Asiapre_534 159..169 Jirí Neustupa,* Yvonne Nemcová, Marek Eliás and Pavel, Czech Republic SUMMARY The traditional green algal genus Chlorella, which com- prised coccoid algae lineage of the trebouxiophycean Watanabea clade, dissimilar from other members of this group. The alga has

294

Hydrogen isotope fractionation in freshwater and marine algae: II. Temperature and nitrogen limited growth rate effects  

E-print Network

Hydrogen isotope fractionation in freshwater and marine algae: II. Temperature and nitrogen limited isotope fractionation in freshwater algae: I. Variations among lipids and spe- cies. Organic Geochemistry. Two species of freshwater green algae, Eudorina unicocca and Volvox aureus, were grown in batch

Sachs, Julian P.

295

DESICCATION PROTECTION AND DISRUPTION: A TRADE-OFF FOR AN INTERTIDAL MARINE ALGA1  

E-print Network

DESICCATION PROTECTION AND DISRUPTION: A TRADE-OFF FOR AN INTERTIDAL MARINE ALGA1 Luke J. H. Hunt2, California 93950, USA For marine algae, the benefits of drying out are often overshadowed by the stresses of desiccation in the intertidal turf alga Endocladia muricata (Endlichter) J. Agardh. Laboratory experiments

Denny, Mark

296

Xylochloris irregularis gen. et sp. nov. (Trebouxiophyceae, Chlorophyta), a novel subaerial coccoid green alga  

E-print Network

green alga JIR I´ NEUSTUPA 1 *, MAREK ELIA´ S1 , PAVEL SKALOUD 1 , YVONNE NE MCOVA´ 1 AND LENKA irregularis gen. et sp. nov. (Trebouxiophyceae, Chlorophyta), a novel subaerial coccoid green alga. Phycologia 50: 57­66. DOI: 10.2216/08-64.1 The phylogenetic diversity of subaerial coccoid green algae remains

297

A System for Dynamically Monitoring and Warning Algae Blooms in Taihu Lake Based on Remote Sensing  

Microsoft Academic Search

The outbreak of algae blooms in the Taihu Lake, China is more and more frequent in recent years and has become a big threat to ecological environment, aquatic breeding industry and human health. A model to monitor algae blooms based on remote sensing data was developed by analyzing spectral characteristics and content of algae blooms of water samples collected in

Wei Qingyu; Jiang Nan; Lu Heng; Hu Bin

2009-01-01

298

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...

299

Critical conditions for ferric chloride-induced flocculation of freshwater algae.  

PubMed

The effects of algae concentration, ferric chloride dose, and pH on the flocculation efficiency of the freshwater algae Chlorella zofingiensis can be understood by considering the nature of the electrostatic charges on the algae and precipitate surfaces. Two critical conditions are identified which, when met, result in flocculation efficiencies in excess of 90% for freshwater algae. First, a minimum concentration of ferric chloride is required to overcome the electrostatic stabilization of the algae and promote bridging of algae cells by hydroxide precipitates. At low algae concentrations, the minimum amount of ferric chloride required increases linearly with algae concentration, characteristic of flocculation primarily through electrostatic bridging by hydroxide precipitates. At higher algae concentrations, the minimum required concentration of ferric chloride for flocculation is independent of algae concentration, suggesting a change in the primary flocculation mechanism from bridging to sweep flocculation. Second, the algae must have a negative surface charge. Experiments and surface complexation modeling show that the surface charge of C. zofingiensis is negative above a pH of 4.0 ± 0.3 which agrees well with the minimum pH required for effective flocculation. These critical flocculation criteria can be extended to other freshwater algae to design effective flocculation systems. PMID:21882173

Wyatt, Nicholas B; Gloe, Lindsey M; Brady, Patrick V; Hewson, John C; Grillet, Anne M; Hankins, Matthew G; Pohl, Phillip I

2012-02-01

300

The production of antimicrobial compounds by British marine algae II. Seasonal variation in production of antibiotics  

Microsoft Academic Search

Eleven known antibiotic-producing species of British marine algae were quantitatively screened at monthly intervals for the presence of antibacterial compounds. The antibacterial components of the algae were extracted with acetone and then assayed against Staphylococcus aureus. The results indicate that seasonal variation in antibiotic production occurs in some marine algae and also that four main patterns of production can be

I. S. Hornsey; D. Hide

1976-01-01

301

INHIBITION OF PHOTOSYNTHESIS IN CERTAIN ALGAE BY EXTREME RED LIGHT  

E-print Network

INHIBITION OF PHOTOSYNTHESIS IN CERTAIN ALGAE BY EXTREME RED LIGHT GOVINDJEE, EUGENE RABINOWITCH, and JAN B. THOMAS From the Photosynthesis Research Laboratory, Department of Botany, University photosynthesis produced by "far red" light (up to 720 m,u). From the action spectrum of this phenomenon

Govindjee

302

Satellite-Observed Algae Blooms in China's Lake Taihu  

Microsoft Academic Search

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

Menghua Wang; Wei Shi

2008-01-01

303

Phylogeny and Molecular Evolution of the Green Algae  

Microsoft Academic Search

The green lineage (Viridiplantae) comprises the green algae and their descendants the land plants, and is one of the major groups of oxygenic photosynthetic eukaryotes. Current hypotheses posit the early divergence of two discrete clades from an ancestral green flagellate. One clade, the Chlorophyta, comprises the early diverging prasinophytes, which gave rise to the core chlorophytes. The other clade, the

Frederik Leliaert; David R. Smith; Hervé Moreau; Matthew D. Herron; Heroen Verbruggen; Charles F. Delwiche; Olivier De Clerck

2012-01-01

304

Intracellular invasion of green algae in a salamander host.  

PubMed

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

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

2011-04-19

305

Intracellular invasion of green algae in a salamander host  

PubMed Central

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

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

2011-01-01

306

Smallest Algae Thrive As the Arctic Ocean Freshens  

E-print Network

Smallest Algae Thrive As the Arctic Ocean Freshens William K. W. Li,1 * Fiona A. McLaughlin,2 presumably differs. Here, we show that, in the changing Arctic Ocean, the smallest phytoplankton cells thrive than others; there will be ecological winners and losers. In the Arctic, rising air temperature

Shull, David H.

307

Halogenated sesquiterpenes from the red alga Laurencia obtusa  

Microsoft Academic Search

Five sesquiterpenes along with three known ones, were isolated from the organic extract of the red alga Laurencia obtusa, collected at Milos island in the Aegean Sea, Greece. The structures of the new natural products, as well as their relative stereochemistry, were established by means of spectral data analyses, including 2D NMR experiments. The isolated metabolites were evaluated, but found

Dimitra Iliopoulou; Vassilios Roussis; Christophe Pannecouque; Erik De Clercq; Constantinos Vagias

2002-01-01

308

A Realistic Technology and Engineering Assessment of Algae Biofuel Production  

E-print Network

A Realistic Technology and Engineering Assessment of Algae Biofuel Production T of microalgae biofuels production through an analysis of five production scenarios. These scenarios, or cases microalgae biofuel technologies for both oil and biogas production, provides an initial assessment of the US

Quinn, Nigel

309

Carotenoid Biosynthesis in the Primitive Red Alga Cyanidioschyzon merolae  

Microsoft Academic Search

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

Francis X. Cunningham; Hansel Lee; Elisabeth Gantt

2007-01-01

310

Carbon Partitioning in Green Algae (Chlorophyta) and the Enolase Enzyme  

PubMed Central

The exact mechanisms underlying the distribution of fixed carbon within photoautotrophic cells, also referred to as carbon partitioning, and the subcellular localization of many enzymes involved in carbon metabolism are still unknown. In contrast to the majority of investigated green algae, higher plants have multiple isoforms of the glycolytic enolase enzyme, which are differentially regulated in higher plants. Here we report on the number of gene copies coding for the enolase in several genomes of species spanning the major classes of green algae. Our genomic analysis of several green algae revealed the presence of only one gene coding for a glycolytic enolase [EC 4.2.1.11]. Our predicted cytosolic localization would require export of organic carbon from the plastid to provide substrate for the enolase and subsequent re-import of organic carbon back into the plastids. Further, our comparative sequence study of the enolase and its 3D-structure prediction may suggest that the N-terminal extension found in green algal enolases could be involved in regulation of the enolase activity. In summary, we propose that the enolase represents one of the crucial regulatory bottlenecks in carbon partitioning in green algae. PMID:25093929

Polle, Jurgen E. W.; Neofotis, Peter; Huang, Andy; Chang, William; Sury, Kiran; Wiech, Eliza M.

2014-01-01

311

Degradation of petroleum by an alga, Prototheca zopfii  

Microsoft Academic Search

Prototheca zopfii is an achlorophyllous alga which degrades oil. It has been found to degrade 10 and 40 percent 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

J. D. Walker; R. R. Colwell; L. Petrakis

1975-01-01

312

Chile, 2009 HYDRAULIC MANAGEMENT OF FILAMENTOUS ALGAE IN  

E-print Network

7 th ISE & 8 th HIC Chile, 2009 HYDRAULIC MANAGEMENT OF FILAMENTOUS ALGAE IN OPEN-CHANNEL NETWORKS channels which are specific eco-systems for many reasons. Firstly, they have to fulfill hydraulic, artificial channels have a relatively simple geometry and their hydraulic variables are easier to monitor

Paris-Sud XI, Université de

313

Using CO2 & Algae to Treat Wastewater and  

E-print Network

Using CO2 & Algae to Treat Wastewater and Produce Biofuel Feedstock Tryg Lundquist Cal Poly State School, UCSB March 23, 2007 #12;CO2 and Wastewater Treatment · WW Treatment Technologies · Scale Actinastrum sp. #12;Major Wastewater Treatment Technologies in U.S. Activated Sludge 6,800 Facilities 25

Keller, Arturo A.

314

Photosynthetic hydrogen and oxygen production by green algae  

Microsoft Academic Search

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.

E. Greenbaum; J. W. Lee

1997-01-01

315

Introduction slide 2 Biofuels and Algae Markets, Systems,  

E-print Network

such as jatropha, recycled waste and sewage feedstock · China is Installing Two 500 MW Coal-Fired Power Plants Algae Market Potential US Military is #1 Consumer of Diesel Fuel in The World Industrial Diesel Markets · Traditional use of waste vegetable oil · Plans for bigger plants using non-food sources

316

Toxicity testing with freshwater algae in River Periyar (India)  

Microsoft Academic Search

A wide range of toxicity tests have been developed in the recent decades to predict the probable effect of new chemicals and effluents on aquatic ecosystem, utilizing different organisms such as algae, crustaceans, molluscs and fish (Sprague 1973; Walsh et al. 1980; Reish and Oshida 1986). Walsh et al. (1982) observed that \\

C. M. Joy

1990-01-01

317

FINE STRUCTURE AND ORGANELLE ASSOCIATIONS IN BROWN ALGAE  

PubMed Central

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

Bouck, G. Benjamin

1965-01-01

318

Carbon partitioning in green algae (chlorophyta) and the enolase enzyme.  

PubMed

The exact mechanisms underlying the distribution of fixed carbon within photoautotrophic cells, also referred to as carbon partitioning, and the subcellular localization of many enzymes involved in carbon metabolism are still unknown. In contrast to the majority of investigated green algae, higher plants have multiple isoforms of the glycolytic enolase enzyme, which are differentially regulated in higher plants. Here we report on the number of gene copies coding for the enolase in several genomes of species spanning the major classes of green algae. Our genomic analysis of several green algae revealed the presence of only one gene coding for a glycolytic enolase [EC 4.2.1.11]. Our predicted cytosolic localization would require export of organic carbon from the plastid to provide substrate for the enolase and subsequent re-import of organic carbon back into the plastids. Further, our comparative sequence study of the enolase and its 3D-structure prediction may suggest that the N-terminal extension found in green algal enolases could be involved in regulation of the enolase activity. In summary, we propose that the enolase represents one of the crucial regulatory bottlenecks in carbon partitioning in green algae. PMID:25093929

Polle, Jürgen E W; Neofotis, Peter; Huang, Andy; Chang, William; Sury, Kiran; Wiech, Eliza M

2014-01-01

319

Spectral shifting by dyes to enhance algae growth  

SciTech Connect

The photosynthetic growth action spectrum of a green alga at three bands of visible light (blue, orange, and red) at fixed quanta input and under light-limiting conditions was measured in a batch cultivation system. Quantum efficiencies (biomass dry weight increment per quanta absorbed) were better in the yellow-red region than in the blue region. Results served as a basis for the design and optimization of a dye system that would shift the energy of solar radiation to the required wavelength range by absorbing ultraviolet to blue radiation and emitting in the yellow-red, thus enhancing algae growth. Direct incorporation of dyes into the growth medium, although theoretically expected to enhance growth, in fact resulted in dye decomposition, toxicity to algae and consequently in growth inhibition. Indirect application of dyes in a double tubular reactor (algae inside and dye solution outside) demonstrated growth enhancement for certain dyes with high quantum yields and stability, which had suitable absorption/emission spectra for artificial light sources used. The maximum indirect growth enhancement was obtained using rhodamine 6G at a concentration of 3 X 10/sup -5/M with tungsten filament lamp sources.

Prokop, A.; Ahmed, S.A.; Fekri, M.; Murad, M.; Quinn, M.F.

1984-11-01

320

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 ...

321

Interactions between algae and the microbial loop in experimental microcosms  

Microsoft Academic Search

We conducted a short-term microcosm experiment to study the direct and indirect effects of a bacterivore on bacteria and the dynamics of two species of green algae. We introduced Scenedesmus, Chlorella and Colpidium, a bacterivorous ciliate, succes- sively in a carbon-rich medium. Bacteria were introduced with Scenedesmus, Chlorella and Colpidium. The experiment lasted 40 days, preventing us from detecting whether

Florence D. Hulot; Peter J. Morin; Michel Loreau

2001-01-01

322

ROCK FILTERS FOR REMOVAL OF ALGAE FROM LAGOON EFFLUENTS  

EPA Science Inventory

The objective of this project was to show that rock filtration was an effective, low cost unit process for removing algae from lagoon effluents and correspondingly upgrading lagoon treatment. Sedimentation is the primary mechanism of algal removal within rock filter. The settling...

323

Limiting factors in phytoplankton algae: their meaning and measurement.  

PubMed

There are two common responses of plants to changes in concentration of limiting factors: change in the final yield (type I response) or change in the growth rate (type II response). Type II is typical of phytoplankton algae in nature, yet some experiments have failed to show growth rate changes because of inappropriate experimental design. PMID:5086394

O'Brien, W J

1972-11-10

324

Biosorption of reactive dyes on the green alga Chlorella vulgaris  

Microsoft Academic Search

Biosorption of three vinyl sulphone type reactive dyes (Remazol Black B (RB), Remazol Red RR (RR) and Remazol Golden Yellow RNL (RGY)) onto dried Chlorella vulgaris, a green alga was investigated in a batch system. The algal biomass exhibited the highest dye uptake capacity at the initial pH value of 2.0 for all dyes. The effect of temperature on equilibrium

Zümriye Aksu; Sevilay Tezer

2005-01-01

325

A green Paramecium strain with abnormal growth of symbiotic algae.  

PubMed

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

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

2010-01-01

326

Hydrogen from Mosses and Algae via Pyrolysis and Steam Gasification  

Microsoft Academic Search

In this study, the effect of temperature on the yield of hydrogen from two mosses (Polytrichum commune and Thuidium tamarascinum) and two algae (Cladophora fracta and Chlorella protothecoid) by pyrolysis and steam gasification were investigated. In each run, the main components of the gas phase were CO2, CO, H2, and CH4. The yields of hydrogen by pyrolysis and steam gasification

A. Demirbas

2009-01-01

327

Thermochemical Conversion of Mosses and Algae to Gaseous Products  

Microsoft Academic Search

The effect of temperature on the yield of hydrogen from two mosses (Polytrichum commune and Thuidium tamarascinum) and two algae (Cladophora fracta and Chlorella protothecoid) by pyrolysis and steam gasification were investigated in this study. In each run, the main components of the gas phase were CO2, CO, H2, and CH4. The yields of hydrogen by pyrolysis and steam gasification

A. Demirbas

2009-01-01

328

The development of artificial media for marine algae  

Microsoft Academic Search

The culturing of marine algae has proceeded slowly since MIQV~L (1890 93) succeeded in growing a few diatoms in the laboratory. Until recently most media were composed of sea water or sea water-like artificial solutions which are prone to precipitate because of the presence of several salts in concentration near saturation. In order to avoid precipitates such media must be

L. Provasoli; J. J. A. McLaughlin; M. R. Droop

1957-01-01

329

Antibiotic activity of lectins from marine algae against marine vibrios.  

PubMed

Saline and aqueous ethanol extracts of marine algae and the lectins from two red algal species were assayed for their antibiotic activity against marine vibrios. Experimental studies were also carried out on the influence of environmental factors on such activity, using batch cultures. The results indicated that many of the saline extracts of the algal species were active and that the activity was selective against those vibrios assayed. The algal extracts were active against Vibrio pelagius and the fish pathogen V. vulnificus, but inactive against V. neresis. Algal lectins from Eucheuma serra (ESA) and Galaxaura marginata (GMA) strongly inhibited V. vulnificus but were inactive against the other two vibrios. The antibacterial activity of algal extracts was inhibited by pretreatment with various sugars and glycoprotein. Extracts of the two red algae, E. serra and Pterocladia capillacea, in saline and aqueous ethanol, inhibited markedly the growth rate of V. vulnificus at very low concentrations. Culture results indicated that metabolites active against V. vulnificus were invariably produced in P. capillacea over a wide range of temperature, light intensity, and nutritional conditions. Enhanced antibacterial activity occurred when P. capillacea was grown under higher irradiance, severe nutrient stress and moderate temperature (20 degrees C), reflecting the specific antibiotic characteristics of this alga. The strong antibiotic activity of lectins towards fish pathogenic bacteria reveals one of the important roles played by algal lectins, as well as the potential high economic value of those marine algae assayed for aquaculture and for biomedical purposes. PMID:12884128

Liao, W-R; Lin, J-Y; Shieh, W-Y; Jeng, W-L; Huang, R

2003-07-01

330

Signal transduction during fertilization in the unicellular green alga, Chlamydomonas  

Microsoft Academic Search

Sexual reproduction in the green alga, Chlamydomonas, is regulated by environmental conditions and by cell–cell interactions. After gametogenesis, flagellar adhesion between gametes triggers gamete activation, leading to cell fusion and zygote formation. Recent studies have identified new molecular events that underlie signal transduction during Chlamydomonas fertilization, including expression of a sex-determining protein, phosphorylation of a homeodomain protein, activity of a

Junmin Pan; William J Snell

2000-01-01

331

Triassic origin and early radiation of multicellular volvocine algae  

E-print Network

Triassic origin and early radiation of multicellular volvocine algae Matthew D. Herron1 , Jeremiah transitions in individuality (ETIs) underlie the water- shed events in the history of life on Earth, including the origins of cells, eukaryotes, plants, animals, and fungi. Each of these events constitutes an increase

332

Optimization of light use efficiency for biofuel production in algae.  

PubMed

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

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

2013-12-01

333

Expression and assembly of a fully active antibody in algae  

NASA Astrophysics Data System (ADS)

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.

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

2003-01-01

334

Switchable photosystem-II designer algae for photobiological hydrogen production  

DOEpatents

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.

Lee, James Weifu (Knoxville, TN)

2010-01-05

335

Phytotoxicity, bioaccumulation and degradation of isoproturon in green algae.  

PubMed

Isoproturon (IPU) is a pesticide used for protection of land crops from weed or pathogen attack. Recent survey shows that IPU has been detected as a contaminant in aquatic systems and may have negative impact on aquatic organisms. To understand the phytotoxicity and potential accumulation and degradation of IPU in algae, a comprehensive study was performed with the green alga Chlamydomonas reinhardtii. Algae exposed to 5-50 ?g L(-1) IPU for 3d displayed progressive inhibition of cell growth and reduced chlorophyll fluorescence. Time-course experiments with 25 ?g L(-1) IPU for 6d showed similar growth responses. The 72 h EC50 value for IPU was 43.25 ?g L(-1), NOEC was 5 ?g L(-1) and LOEC was 15 ?g L(-1). Treatment with IPU induced oxidative stress. This was validated by a group of antioxidant enzymes, whose activities were promoted by IPU exposure. The up-regulation of several genes coding for the enzymes confirmed the observation. IPU was shown to be readily accumulated by C. reinhardtii. However, the alga showed a weak ability to degrade IPU accumulated in its cells, which was best presented at the lower concentration (5 ?g L(-1)) of IPU in the medium. The imbalance of accumulation and degradation of IPU may be the cause that resulted in the detrimental growth and cellular damage. PMID:23131497

Bi, Yan Fang; Miao, Shan Shan; Lu, Yi Chen; Qiu, Chong Bin; Zhou, You; Yang, Hong

2012-12-01

336

Algae 2013, 28(4): 297-305 http://dx.doi.org/10.4490/algae.2013.28.4.297  

E-print Network

Algae 2013, 28(4): 297-305 http://dx.doi.org/10.4490/algae.2013.28.4.297 Open Access Review Copyright © The Korean Society of Phycology 297 http://e-algae.kr pISSN: 1226-2617 eISSN: 2093-0860 Interactions between marine bacteria and red tide organisms in Korean waters Kyeong Ah Seong1, * and Hae Jin

Jeong, Hae Jin

337

Marine algae: screening for a potent antibacterial agent.  

PubMed

This study was done to investigate the antimicrobial potentiality of the marine algae collected from different coastal regions of Gujarat and screened for the same. Twenty-six marine algae belonging to Rhodophyceae, Chlorophyceae and Phaeophyceae were screened for their potential antibacterial activity against five clinically important bacterial strains, namely Bacillus cereus, Micrococcus flavus, Citrobacter freundii, Klebsiella pneumoniae and Pseudomonas testosterone. Acetone and methanol were used for extraction; and the extracted yield was more when the solvent used was methanol. The antibacterial activity was done by both Agar disc diffusion method and Agar ditch method. The five bacterial strains showed varied response towards marine algal extracts. The most susceptible bacteria was B. cereus followed by K. pneumoniae and C. freundii while the most resistant bacteria were M. flavus and P. testosteroni. Among the 26 algae screened, E. intestinalis was the most potent alga and thus, this alga was selected for further studies. E. intestinalis was extracted in petroleum ether, 1,4-dioxan, acetone, methanol and DMF, and their antibacterial activity was studied against the above-stated five bacterial strains using agar disc method. Maximum extractive value of E. intestinalis was in methanol (2.05%) and minimum was in acetone (0.38%). The most susceptible bacteria was K. pneumoniae and maximum antibacterial activity was shown by petroleum ether extract and minimum was shown by 1,4-dioxan extract. The most resistant bacteria were M. flavus and C. freundii. The MIC values of E. intestinalis extracts ranged from 2500-9.765 microg/0.5 ml against B. cereus and K. pneumoniae. From these results it is concluded that the acetone extract of E. intestinalis is the most potent extract and can be used as a lead molecule in drug discovery in inhibiting some of the bacterial strains. E. intestinalis can be used as a promising novel marine antimicrobial agent in the coming years. PMID:17594989

Nair, Ratish; Chabhadiya, Rajesh; Chanda, Sumitra

2007-01-01

338

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

SciTech Connect

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.

Fujita, Toyohisa; Kogita, Hiroki; Mamiya, Mitsuo [Akita Univ. (Japan). Mining Coll.; Yen, W.T. [Queen`s Univ., Kingston, Ontario (Canada)

1995-12-31

339

DELAYED LIGHT ACTION SPECTRA OF SEVERAL ALGAE IN VISIBLE AND ULTRAVIOLET LIGHT*,  

E-print Network

Action spectra for delayed light production by several algae were determined from 250 to 750 m ~ incident light. In the visible portion of the spectrum the action spectra resemble those reported by previous workers for photosynthesis and light emission. Blue-green algae had a maximum at 620 m~, red algae at 550 m~, whereas green and brown algae have action spectra corresponding to chlorophyll and carotenoid absorption. In the ultraviolet portion of the spectrum delayed light is emitted by algae down to 250 m ~ incident light. The action spectra of the different algae are not alike in the ultraviolet portion of the spectrum. This indicates that pigments other than chlorophyll must be sensitizing or shielding the algae in the ultraviolet region.

G. C. Mc. Leod

340

Red algae fibre\\/poly(butylene succinate) biocomposites: The effect of fibre content on their mechanical and thermal properties  

Microsoft Academic Search

The red algae (Gelidium Elegance) fibre was examined as a reinforcement of biocomposite. The extracting and bleaching process of the fibre from red algae were effective for both removal of mucilage materials and fiberization of red algae fibre. The bleached red algae fibre (BRAF) showed very similar crystallinity to the cellulose and also higher thermal stability with the maximum thermal

Min Woo Lee; Seong Ok Han; Yung Bum Seo

2008-01-01

341

Carnets de Gologie / Notebooks on Geology -Article 2006/03 (CG2006_A03) Are the green algae (phylum Viridiplantae)  

E-print Network

Carnets de Géologie / Notebooks on Geology - Article 2006/03 (CG2006_A03) 1 Are the green algae planet, A.H. KNOLL states that the first documented fossils of green algae date back 750 Ma. However" and of a primitive clade of green algae, the Pyramimonadales. A paraphyletic group of unicellular green algae, named

Paris-Sud XI, Université de

342

Modeling and control of algae detachment in regulated canal networks Ophelie Fovet, Xavier Litrico and Gilles Belaud  

E-print Network

Modeling and control of algae detachment in regulated canal networks Ophelie Fovet, Xavier Litrico and Gilles Belaud Abstract-- Algae development in open-channel networks in- duce major disturbances because these algae developments consists in flushing the fixed algae. The flush is carried out by increasing

Paris-Sud XI, Université de

343

A preliminary study on automated freshwater algae recognition and classification system  

PubMed Central

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. PMID:23282059

2012-01-01

344

A New Noncalcified Dasycladalean Alga from the Silurian of Wisconsin  

USGS Publications Warehouse

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.

LoDuca, S.T.; Kluessendorf, J.; Mikulic, D.G.

2003-01-01

345

Green Algae as Model Organisms for Biological Fluid Dynamics  

E-print Network

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 $\\mu$m 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.

Raymond E. Goldstein

2014-09-08

346

Hydrostatic factors affect the gravity responses of algae and roots  

NASA Technical Reports Server (NTRS)

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.

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

1991-01-01

347

Mahorones, highly brominated cyclopentenones from the red alga Asparagopsis taxiformis.  

PubMed

The red alga Asparagopsis taxiformis (Rhodophyta, Bonnemaisoniaceae) has been shown to produce a large diversity of halogenated volatile organic compounds, with one to four carbons. As the distribution of this alga may expand worldwide, we implemented a research program that aims to understand the functions of its specialized metabolome in marine ecosystems. Phytochemical investigations performed on A. taxiformis gametophyte stages from the Indian Ocean revealed two new highly brominated cyclopentenones named mahorone (1) and 5-bromomahorone (2). They are the first examples of natural 2,3-dibromocyclopentenone derivatives. Their structure elucidation was achieved using spectrometric methods including NMR and MS. A standardized ecotoxicological assay was used as an assessment of their role in the environment, revealing high toxicities for both compounds (EC50 0.16 ?M for 1 and 2). Additionally, both compounds were evaluated in antibacterial, antifungal, and cytotoxicity assays. Compounds 1 and 2 exhibit mild antibacterial activities against the human pathogen Acinetobacter baumannii. PMID:24746270

Greff, Stéphane; Zubia, Mayalen; Genta-Jouve, Grégory; Massi, Lionel; Perez, Thierry; Thomas, Olivier P

2014-05-23

348

The versatility of algae and their lipid metabolism.  

PubMed

Eukaryotic algae are a very diverse group of organisms that are key components of ecosystems ranging from deserts to the Antarctic. They account for over half of the primary production at the base of food chains. The lipids of different classes are varied and contain unusual compounds not found in other phyla. In this short review, we introduce the major cellular lipids and their fatty acids and then describe how the latter (particularly the polyunsaturated fatty acids, PUFAs) are synthesised. The discovery of different elongases and desaturases important for PUFA production is detailed and their application for biotechnology described. Finally, the potential for algae in commercial applications is discussed, particularly in relation to the production of very long chain PUFAs and biofuel. PMID:19063932

Harwood, John L; Guschina, Irina A

2009-06-01

349

Biofouling attractants from a brown marine alga Ecklonia cava.  

PubMed

In recent years, industrial pollutants and the mountain forest fire ashes released into seawater cause damage to the marine environment, mainly it reduces the algal productivity in the inter tidal region. To get recover from the stress due to pollutants and to increase the growth and development of biofouling algae (benthic organisms), Ecklonia cava extract was investigated for its biofouling attracting efficiency. Bioactive guided fractions of E. cava extract derived from column chromatography were tested against spore attachment of a fouling alga, Ulva pertusa. Fraction B showed increased spore attachment rate with a maximum of 92 +/- 5%. This fraction was further analysed on HPLC, GC-Mass and NMR, deduced as pentadecanoic acid. PMID:17915745

Sidharthan, M; Viswanadh, G S; Kim, Kyoung Ho; Kim, Hyuk Jun; Shin, H W

2007-04-01

350

Green Algae as Model Organisms for Biological Fluid Dynamics  

E-print Network

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 $\\mu$m 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 re...

Goldstein, Raymond E

2014-01-01

351

Bioremoval of toxic elements with aquatic plants and algae  

SciTech Connect

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).

Wang, T.C.; Ramesh, G. [Harbor Branch Oceanographic Inst., Fort Pierce, FL (United States); Weissman, J.C.; Varadarajan, R. [Microbial Products, Inc., Vero Beach, FL (United States); Benemann, J.R.

1995-12-31

352

Biosorption of lead and nickel by biomass of marine algae  

SciTech Connect

Screening tests of different marine algae biomass 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 performed 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.

Holan, Z.R.; Volesky, B. (McGill Univ., Montreal, Quebec (Canada). Dept. of Chemical Engineering)

1994-05-01

353

Algae-grazing minnows ( Campostoma anomalum ), piscivorous bass ( Micropterus spp.), and the distribution of attached algae in a small prairie-margin stream  

Microsoft Academic Search

Campostoma anomalum is an algae-grazing minnow, abundant in many streams of the central and eastern United States. In a small stream in south-central Oklahoma, Campostoma has a marked impact on standing crops of attached algae. Pools with schools of Campostoma are barren, while pools in which Campostoma are apparently excluded by bass (Micropterus salmoides or M. punctulatus) support large standing

Mary E. Power; William J. Matthews

1983-01-01

354

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

NASA Astrophysics Data System (ADS)

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%.

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

2013-12-01

355

Phytochemical studies of the southern Australian marine alga, Laurencia elata.  

PubMed

Chemical profiling of the southern Australian marine alga Laurencia elata (Rhodomelaceae) employing on-flow and stop-flow HPLC-NMR methodology followed by off-line chemical investigations resulted in the isolation of two C16 chamigrenes, cycloelatanene A and B together with three previously reported sesquiterpenes, (3Z)-chlorofucin, pacifenol and elatenyne. The chemical structures were elucidated via detailed spectroscopic analyses. PMID:21802699

Dias, Daniel Anthony; Urban, Sylvia

2011-11-01

356

Algae sequester heavy metals via synthesis of phytochelatin complexes  

Microsoft Academic Search

A Cd-binding complex was isolated from Chlorella fusca and has been shown to be composed of phytochelating peptides, (?-Glu-Cys)n-Gly, n=2–5. Members of six of the ten classes of Phycophyta revealed phytochelatin synthesis after exposure to cadmium ions. Phytochelatin was also induced by ions of lead, zinc, silver, copper and mercury. These experiments uneqiovocally demonstrated that algae sequester heavy metals by

Walter Gekeler; Erwin Grill; Ernst-Ludwig Winnacker; Meinhart H. Zenk

1988-01-01

357

FINE STRUCTURE AND ORGANELLE ASSOCIATIONS IN BROWN ALGAE  

Microsoft Academic Search

ABSTRACT The structural interrelationships among,several membrane,systems in the cells of brown algac have been cxamined,by electron microscopy. In the brown,algae the chloroplasts are surrounded by two envclopes, the outer of which in some cases is continuous with the nuclear envelope. The pyrcnoid, when present, protrudes from the chloroplast, is also surrounded by the two chloroplast envelopes, and, in addition, is

G. BENJAMIN BOUCK

1965-01-01

358

Antioxidant role of astaxanthin in the green alga Haematococcus pluvialis  

Microsoft Academic Search

The green unicellular alga, Haematococcus pluvialis has two antioxidative mechanisms against environmental oxidative stress: antioxidative enzymes in vegetative cells and the\\u000a antioxidative ketocarotenoid, astaxanthin, in cyst cells. We added a reagent that generates superoxide anion radicals (O2\\u000a ?), methyl viologen, to mature and immature cysts of H. pluvialis. Tolerance to methyl viologen was higher in mature than in immature cysts.

M. Kobayashi; T. Kakizono; N. Nishio; S. Nagai; Y. Kurimura; Y. Tsuji

1997-01-01

359

Ultraviolet sunscreen compounds in epiphytic red algae from mangroves  

Microsoft Academic Search

Epiphytic red algae of the order Ceramiales from mangroves and salt marshes (nine species from Bostrychia, three from Stictosiphonia and four from Caloglossa) produce varying levels of the UV-absorbing compounds mycosporine-glycine, shinorine, porphyra-334, palythine, asterina-330 and palythinol, a suite of substances chemically assigned as mycosporine-like amino acids (MAAs). Mean MAA levels varied from 0.02 to 12.8 mg g-1 DW in

Ulf Karsten; Thomas Sawall; John West; Christian Wiencke

2000-01-01

360

Changes of Algae Protein Complex under pH Effect  

Microsoft Academic Search

It was established that “blue liquid” formed in the decomposition of blue-green algae (Cyanophyta, Cyanobacteria) results from isolation of water-soluble bilichromoproteins from the cells, mainly phycocyanine and its derivatives, with\\u000a the zone of principal absorption maximum within the limits of 610–630 ?m. The most stable color and spectral peculiarities\\u000a the liquid preserves at pH 6.8–7.2. It was shown that alkalization

Tatyana V. Parshikova

361

Production of carbonate sediments by a unicellular green alga  

Microsoft Academic Search

This study investigates the ability of the unicellular green alga Nannochloris atomusto precipitate CaCO3, quantifies mineral precipitation rates, estimates sediment production in a N. atomus bloom, and discusses the implications of microbial calcification for carbonate sediment deposition. A series of N. atomus cultures, isolated from Lake Reeve, Australia, were incubated at various pH and calcium concentrations to determine environmental pa-

KIMBERLY K. YATES; LISA L. ROBBINS

1998-01-01

362

Biosorption of cadmium by biomass of marine algae  

Microsoft Academic Search

Biomass of nonliving, dried brown marine algae Sargassum natans, Fucus vesiculosus, and Ascophyllum nodosum demonstrated high equilibrium uptake of cadmium from aqueous solutions. The metal uptake by these materials was quantitatively evaluated using sorption isotherms. Biomass of A. nodosum accumulated the highest amount of cadmium exceeding 100 mg Cd[sup 2+]\\/g (at the residual concentration of 100 mg Cd\\/L and pH

Z. R. Holan; B. Volesky; I. Prasetyo

1993-01-01

363

The problems of Prochloron. [evolution of green algae  

NASA Technical Reports Server (NTRS)

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.

Lewin, R. A.

1983-01-01

364

Green algae in tundra soils affected by coal mine pollutions  

Microsoft Academic Search

Green algal communities were investigated in clean and pollution-impacted tundra soils around the large coal mine industrial\\u000a complex of Vorkuta in the E. European Russian tundra. Samples were collected in three zones of open-cast coal mining with\\u000a different degrees of pollution-impacted soil transformation. A total of 42 species of algae were found in all zones. The species\\u000a richness decreased from

Elena N. Patova; Marina F. Dorokhova

2008-01-01

365

Brominated Selinane Sesquiterpenes from the Marine Brown Alga Dictyopteris divaricata  

PubMed Central

Two new brominated selinane sesquiterpenes, 1-bromoselin-4(14),11-diene (1) and 9-bromoselin-4(14),11-diene (2), one known cadinane sesquiterpene, cadalene (3), and four known selinane sesquiterpenes, ?-selinene (4), ?-selinene (5), ?-dictyopterol (6), and cyperusol C (7), were isolated from a sample of marine brown alga Dictyopteris divaricata collected off the coast of Yantai (China). Their structures were established by detailed MS and NMR spectroscopic analysis, as well as comparison with literature data. PMID:19841719

Ji, Nai-Yun; Wen, Wei; Li, Xiao-Ming; Xue, Qin-Zhao; Xiao, Hua-Ling; Wang, Bin-Gui

2009-01-01

366

Barley ( Hordeum vulgare )-induced growth inhibition of algae: a review  

Microsoft Academic Search

Many field and laboratory studies have attempted to explain the inhibitory effect of rotting barley on algae. Early field\\u000a studies lacked controls and replication and results depended on visual observations. Such studies offer information on barley\\u000a bale field construction and application rates. In the laboratory, discrepancies in the barley variety used, algal species\\u000a tested, barley liquor preparation and phenol extraction

Daire Ó hUallacháin; Owen Fenton

2010-01-01

367

Biomacromolecules of Algae and Plants and their Fossil Analogues  

Microsoft Academic Search

A review of our current understanding of resistant biomacromolecules derived from present and past algae and higher plants\\u000a is presented. Insight in the nature of recent and fossil macromolecules is strongly hampered by the difficulties in obtaining\\u000a the material in pure and unaltered form. For the extant material, avoiding artificial condensation and structural alteration\\u000a as a result of chemical isolation

Jan W. de Leeuw; Gerard J. M. Versteegh; Pim F. van Bergen

2006-01-01

368

Antileishmanial sesquiterpenes from the Brazilian red alga Laurencia dendroidea.  

PubMed

Investigation of the bioactive crude extracts from two populations of the red alga Laurencia dendroidea from the southeastern Brazilian coast led to the identification of five sesquiterpenes: (+)-obtusane (1), a triquinane derivative (2), (-)-elatol (3), obtusol (4), and cartilagineol (5). An antileishmanial bioassay against Leishmania amazonensis was conducted for crude lipophilic extracts and for sesquiterpenes 2, 3, and 4. Compounds 3 and 4 displayed in vitro and in vivo leishmanicidal activity and very low cytotoxicity. PMID:21058243

da Silva Machado, Fernanda Lacerda; Pacienza-Lima, Wallace; Rossi-Bergmann, Bartira; de Souza Gestinari, Lísia Mônica; Fujii, Mutue T; Campos de Paula, Joel; Costa, Sônia Soares; Lopes, Norberto Peporine; Kaiser, Carlos Roland; Soares, Angélica Ribeiro

2011-05-01

369

Glycolipids from the red alga Chondria armata (Kutz.) Okamura  

Microsoft Academic Search

Three distinct fractions containing polar glycolipids (PF1-3) were isolated from the chloroform soluble fraction of crude methanolic extract of red alga Chondria armata (Kütz.) Okamura on gel chromatography over Sephadex LH20. Their structure was elucidated by multidimentional nuclear magnetic resonance (NMR) techniques like 1H, 1H correlation spectroscopy (COSY), 1H, 1 H total correlation spectroscopy (TOCSY), 1H, 13C heteronuclear multiple quantum

Ammar Al-Fadhli; Solimabi Wahidulla; Lisette D'Souza

2006-01-01

370

Chapter 9 Algae as ecological bio-indicators  

Microsoft Academic Search

The value of algae as bio-monitors and bio-indicators has already been recognised in the mid 19th century: The first concept which has been developed was the system of saprobity. It was mainly designed for organic pollution of streams and rivers. This system was altered, modified and expanded over the years by several authors. Because saprobity is defined as the intensity

M. T. Dokulil

2003-01-01

371

Gamete recognition during fertilization in a red alga, Antithamnion nipponicum  

Microsoft Academic Search

Summary Fertilization in the marine red algaAntithamnion nipponicum is a highly specific process involving non-motile male gametes, spermatia, and female receptive structures, carpogonia. FITC-lectin and Calcofluor white ST labelling show that the outer cell walls of spermatia differ from vegetative cells in carbohydrate composition. Specific binding of the lectins to spermatial walls was confirmed by lectin-gold labelling on thin sections.

G. H. Kim; L. Fritz

1993-01-01

372

Population Changes in Algae- A Lesson on Ecology  

NSDL National Science Digital Library

This teaching resource was developed by a K-12 science teacher in the American Physiological SocietyÃÂs 2008 Frontiers in Physiology Program. For more information on this program, please visit www.frontiersinphys.org. Students will design and carry out an experiment where they will observe and evaluate how algae population changes when subjected to environmental influences by using a variety of detecting methods like, using a Spectrophotometer or Spec-20 for analyzing algae population density through measuring transmitted and absorbed light passing through growth tubes. An alternative analysis could be done with the assistance of a color wheel or CBL-Colorimeter Probe. This laboratory will fit into any ecology class or a unit on population changes or in any biology class unit dealing with understanding population dynamics and photosynthesis. It could be used for advanced biology classes fitting into population changes, photosynthetic studies, and food chains. Some understanding of light infiltration or absorption of light through photosynthetic organisms will assist in this laboratory. Upon completion of this activity, students will be able to enable student to collect data on living organisms using algae as templates.

2008-08-01

373

Treatment efficacy of algae-based sewage treatment plants.  

PubMed

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

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

2013-09-01

374

Distribution of periphytic algae in wetlands (Palm swamps, Cerrado), Brazil.  

PubMed

The distribution of periphytic algae communities depends on various factors such as type of substrate, level of disturbance, nutrient availability and light. According to the prediction that impacts of anthropogenic activity provide changes in environmental characteristics, making impacted Palm swamps related to environmental changes such as deforestation and higher loads of nutrients via allochthonous, the hypothesis tested was: impacted Palm swamps have higher richness, density, biomass and biovolume of epiphytic algae. We evaluated the distribution and structure of epiphytic algae communities in 23 Palm swamps of Goiás State under different environmental impacts. The community structure attributes here analyzed were composition, richness, density, biomass and biovolume. This study revealed the importance of the environment on the distribution and structuration of algal communities, relating the higher values of richness, biomass and biovolume with impacted environments. Acidic waters and high concentration of silica were important factors in this study. Altogether 200 taxa were identified, and the zygnemaphycea was the group most representative in richness and biovolume, whereas the diatoms, in density of studied epiphyton. Impacted Palm swamps in agricultural area presented two indicator species, Gomphonema lagenula Kützing and Oedogonium sp, both related to mesotrophic to eutrophic conditions for total nitrogen concentrations of these environments. PMID:23917560

Dunck, B; Nogueira, I S; Felisberto, S A

2013-05-01

375

Boron-containing organic pigments from a Jurassic red alga  

PubMed Central

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

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

2010-01-01

376

Cytotoxicity of Algae Extracts on Normal and Malignant Cells  

PubMed Central

Algae preparations are commonly used in alternative medicine. We examined the effects of algae extracts on normal hematopoietic cells and leukemia cells. Ethanol extracts were prepared of Dunaliella salina (Dun), Astaxanthin (Ast), Spirulina platensis (Spir), and Aphanizomenon flos-aquae (AFA). Cell viability effects were completed by Annexin staining. Ast and AFA inhibited HL-60 and MV-4-11 whereas Dun and Spir had no effect. Primary AML blasts demonstrated increased apoptosis in AFA. Primary CLL cells showed apoptosis at 24 hours after exposure to Dun, Ast, Spir, and AFA. High AFA concentrations decreased viability of normal marrow cells. Normal CD34+ viability was inhibited by Dun. Dun and AFA inhibited BFU-E, but all extracts inhibited CFU-GM. Cell-cycle analysis of AML cell lines showed G0/G1 arrest in the presence of AFA. These data suggest that algae extracts may inhibit AML cell lines and leukemia blasts, but they may also have potential inhibitory effects on normal hematopoiesis. PMID:23213541

Bechelli, Jeremy; Coppage, Myra; Rosell, Karen; Liesveld, Jane

2011-01-01

377

Uptake and distribution of technetium in several marine algae  

SciTech Connect

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.

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

378

[Quantitative remote sensing retrieval for algae in inland waters].  

PubMed

Chlorophyll is a very important indictor for the eutrophication status of lake water body. Using remotely sensed data to achieve real-time dynamic monitoring of the spatial distribution of chlorophyll has great importance. This paper aims to find the best band for the hyperspectral ratio model of chlorophyll-a, and take advantage of this model to implement remote sensing retrieval of algae in Taihu Lake. By the analysis of the spectral reflectance and water quality sampling data of the surface water body, the regression model between the ratio of reflectance and chlorophyll-a was built, and it was showed that the ratio model between the wavelengths around 700 and 625 nm had a relatively high coefficient value of determination (R2), while the ratio model constructed with 710 nm and visible wavelengths showed a descended R2 following with the increment of the visible wavelengths. Combined with in-situ water samplings analysis and spectral reflectance measurement, the results showed that it's possible to retrieve algae water body using the MODIS green index (GI). The spatial distributions of chlorophyll-a and algae in Taihu Lake were extracted successfully using MODIS data with the algorithm developed in this paper. PMID:20545165

Song, Yu; Song, Xiao-Dong; Jiang, Hong; Guo, Zhao-Bing; Guo, Qing-Hai

2010-04-01

379

Coralline red algae as high-resolution climate recorders  

NASA Astrophysics Data System (ADS)

Most high-resolution, proxy-based paleoclimate research hasconcentrated on tropical oceans, while mid- and high-latitudemarine regions have received less attention, despite their importancein the global climate system. At present, sclerochronologicalanalyses of bivalve mollusks supply the bulk of annual- to subannual-resolutionextratropical marine climate data, even though interpretationis complicated by a slowdown of growth with increasing shellage. Hence, in order to address the need for additional high-resolutionproxy climate data from extratropical regions, we conductedthe first year-long in situ field calibration of the corallinered alga Clathromorphum compactum in the Gulf of Maine, UnitedStates. Coralline red algae are widely distributed in coastalregions worldwide, and individual calcified plants can livecontinuously for several centuries in temperate and subarcticoceans. Stable oxygen isotopes extracted at subannual resolutionfrom growth increments of monitored specimens of C. compactumrelate well to in situ-measured sea-surface temperaturesduring the May to December calcification period, highlightingthe suitability of coralline red algae as an extratropical climatearchive. Furthermore, there is a strong correlation betweena 30 yr {sigma}18O record of C. compactum and an instrumental sea-surfacetemperature record (r = -0.58, p = 0.0008) and a proxyreconstruction derived from the bivalve Arctica islandica collectedin the central Gulf of Maine (r = 0.54, p = 0.002).

Halfar, J.; Steneck, R. S.; Joachimski, M.; Kronz, A.; Wanamaker, A. D., Jr.

2008-06-01

380

Sustainable Bioenergy Bioprocessing: Biomethane Production, Digestate as Biofertilizer and as Supplemental Feed in Algae Cultivation to Promote Algae Biofuel Commercialization  

Microsoft Academic Search

In this study we developed and tested a sustainable system that produces high-yield outputs of biomethane, biofertilizer and biodiesel. These were achieved by blending of poultry manure (PM), paper pulp and algae waste sludge in co-digestion producing biomethane, digestate fi ltrated to get semi-solid and aqueous, the former as biofertilizer and latter was used in algal cultivation to enhance algal

Gene Drekeke Iyovo; Guocheng Du; Jian Chen

2010-01-01

381

PHOSPHATIZED MULTICELLULAR ALGAE IN THE NEOPROTEROZOIC DOUSHANTUO FORMATION ,C HINA, AND THE EARLY EVOLUTION OF FLORIDEOPHYTE RED ALGAE1  

Microsoft Academic Search

Phosphatic sediments of the Late Neoproterozoic (ca. 600 million years old (Myr)) Doushantuo Formation at Weng'an, South China, contain fossils of multicellular algae preserved in anatomical detail. As revealed by light microscopy and scanning electron microscopy, these fossils include both simple pseudoparenchymatous thalli with apical growth but no cortex-medulla differentiation and more complex thalli characterized by cortex-medulla differentiation and structures

SHUHAI XIAO; ANDREW H. KNOLL; XUNLAI YUAN; CURT M. PUESCHEL

2004-01-01

382

Sludge-Grown Algae for Culturing Aquatic Organisms: Part II. Sludge-Grown Algae as Feeds for Aquatic Organisms  

PubMed

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. PMID:8661608

Wong; Hung; Chiu

1996-05-01

383

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

NASA Astrophysics Data System (ADS)

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.

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

1996-05-01

384

[Effects of nitrogen source and aeration mode on algae growth in freshwater].  

PubMed

Aquarium microcosms were used to study the effects of nitrogen source and aeration mode on the growth and species changes of algae in freshwater. Nitrate nitrogen(NO3(-) -N) and ammonia nitrogen(NH4(+) -N) were used as nitrogen sources. For each nitrogen source, four modes of aeration were selected, including control, continuous aeration, aeration during the day, and aeration at night. In the early stage of the experiment, algae in the NH4(+) -N treatment experiment grew well. In the later stage, algae in the NO3(-) -N treatment experiment grew better. For different aeration modes, continuous aeration show varied effects on algae growth in the two nitrogen source treatments. Day-only aeration had little effect on algae growth. Night-only aeration inhibited algae growth considerably. In NH(+) -N treatments, cyanophyta became dominant species easily. In contrast, chlorophyta dominated in NO3(-) -N treatments. PMID:16599129

Liu, Chun-Guang; Jin, Xiang-Can; Sun, Ling; Sun, Hong-Wen; Zhu, Lin; Yu, Yang; Dai, Shu-Gui; Zhuang, Yuan-Yi

2006-01-01

385

The Future is Green: On the Biotechnological Potential of Green Algae  

Microsoft Academic Search

\\u000a There are two main players that form the basis of nearly all global ecosystems in converting solar energy to biomass: algae\\u000a and plants. While plants are omnipresent in public discussions dealing with such topics as climate change, bioreactors, biofuels\\u000a and green biotechnology, the role and potential of algae is usually known only to experts. However, algae are present as primary

Werner Reisser

386

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

Microsoft Academic Search

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 (?=365nm, 250W). 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

Lin Deng; Hongli Wang; Nansheng Deng

2006-01-01

387

A comparison of bacterial removal efficiencies in constructed wetlands and algae-based systems  

Microsoft Academic Search

Constructed wetlands and algae-based systems have been compared regarding their efficiencies on faecal bacteria removal. Two types of constructed wetlands, sub-surface (SSF) and free water surface (FWS) flow systems, and two more types of algae-based systems, high rate algae ponds (HRAP) and maturation pond (MP) have been studied for two years. All systems treated the same wastewater from a rural

Mercedes García; Félix Soto; Juan M. González; Eloy Bécares

2008-01-01

388

Phylogenetic Analyses of the &CL Sequences from Haptophytes and Heterokont Algae Suggest Their Chloroplasts are Unrelated  

Microsoft Academic Search

Using the large subunit of RuBisCo (&CL) sequences from cyanobacteria, proteobacteria, and diverse groups of algae and green plants, we evaluated the plastid relationship between haptophytes and heterokont algae. The &CL sequences were determined from three taxa of heterokont algae (Bumilleriopsis jiliformis, Pelagomonas calceolata, and Pseudopedinella elastica) and added to 25 published sequences to obtain a data set comprising 1,434

Niels Daugbjerg; Robert A. Andersen

389

Zooplankton feeding on algae and bacteria under ice in Lake Druzhby, East Antarctica  

Microsoft Academic Search

The feeding of the cladoceran Daphniopsis studeri on algae and bacteria was investigated under ice in an ultra-oligotrophic Antarctic lake from late autumn (May) to early\\u000a spring (October) in 2004. D. studeri fed on both algae and bacteria with estimated filtering rates of 0.048 and 0.061 l ind?1 day?1), respectively. Algae seemed to be the major food resource for the D. studeri

Christin Säwström; Jan Karlsson; Johanna Laybourn-Parry; Wilhelm Granéli

2009-01-01

390

Uptake, elimination and biochemical effects of azadirachtin and tebufenozide in algae  

Microsoft Academic Search

Effects of azadirachtin (isomer A, AZ?A) and tebufenozide (TF) on freshwater algae were investigated using indoor aquatic microcosms. AZ?A and TF were dosed at different concentrations to 10?L microcosms. Chlorophyll and protein contents of the algae, and the concentrations of the insecticides in water and algae were monitored at intervals of time up to 20 d. Chlorophyll and protein contents

K. M. S. Sundaram

1997-01-01

391

Hatchery cultivation of Pacific oyster juveniles using algae produced in outdoor bloom-tanks  

Microsoft Academic Search

Algae were bloomed as batch cultures by adding fertilizers to natural seawater in 500 l outdoor tanks, from mid-June to mid-August, over a period of 2 y. In the first year of experiments the bloomed algae were fed to Pacific oyster (Crassostrea gigas Thunberg) juveniles at a range of rations from 0.06 to 1.63 g (organic weight of algae) g–1

Ian Laing; Ren-Mou Chang

1998-01-01

392

Rôle of blue-green algae and different methods of partial soil sterilization on rice yield  

Microsoft Academic Search

Summary  Results of experiments during three consecutive seasons on the rôle of blue-green algae in combination with partial soil sterilization\\u000a and chemical nutrients indicate high responses to algae inoculation and a fertility build-up of the soil. It is also seen\\u000a that blue-green algae tend to produce better response in soils which are poor.

R. Subrahmanyan; L. L. Relwani; G. B. Manna

1964-01-01

393

Hierarchical and size dependent mechanical properties of silica and silicon nanostructures inspired by diatom algae  

E-print Network

Biology implements fundamental principles that allow for attractive mechanical properties, as observed in biomineralized structures. For example, diatom algae contain nanoporous hierarchical silicified shells that provide ...

García, Andre Phillipé

2010-01-01

394

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

ERIC Educational Resources Information Center

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)

Hungerford, James J.

1988-01-01

395

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...

396

The nucleotide sequences of 5S rRNAs from a multicellular green alga, Ulva pertusa, and two brown algae, Eisenia bicyclis and Sargassum fulvellum.  

PubMed

The nucleotide sequences of 5S rRNA from a multicellular green alga Ulva pertusa, and multicellular brown algae Eisenia bicyclis and Sargassum fulvellum, have been determined. The 5S rRNA from Ulva is composed of 120 nucleotides, and those from Eisenia and Sargassum have 118 nucleotides. The nucleotide sequence of Ulva 5S rRNA is rather similar to 5S rRNAs from unicellular green algae and higher plants, while those of Eisenia and Sargassum 5S rRNAs are unique. PMID:6835842

Lim, B L; Hori, H; Osawa, S

1983-03-25

397

Survival and reproduction in some algae under stress conditions.  

PubMed

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

Gupta, S; Agrawal, S C

2007-01-01

398

Multispectral sorter for rapid, nondestructive optical bioprospecting for algae biofuels  

NASA Astrophysics Data System (ADS)

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.

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

2014-03-01

399

Carotenoid Biosynthesis in the Primitive Red Alga Cyanidioschyzon merolae?  

PubMed Central

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

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

2007-01-01

400

The ecology of viruses that infect eukaryotic algae.  

PubMed

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

Short, Steven M

2012-09-01

401

Spectroradiometric monitoring for open outdoor culturing of algae and cyanobacteria.  

PubMed

We assess the measurement of hyperspectral reflectance for outdoor monitoring of green algae and cyanobacteria cultures with a multichannel, fiber-coupled spectroradiometer. Reflectance data acquired over a 4-week period are interpreted via numerical inversion of a reflectance model, in which the above-water reflectance is expressed as a quadratic function of the single backscattering albedo, which is dependent on the absorption and backscatter coefficients. The absorption coefficient is treated as the sum of component spectra consisting of the cultured species (green algae or cyanobacteria), dissolved organic matter, and water (including the temperature dependence of the water absorption spectrum). The backscatter coefficient is approximated as the scaled Hilbert transform of the culture absorption spectrum with a wavelength-independent vertical offset. Additional terms in the reflectance model account for the pigment fluorescence features and the water-surface reflection of sunlight and skylight. For the green algae and cyanobacteria, the wavelength-independent vertical offset of the backscatter coefficient is found to scale linearly with daily dry weight measurements, providing the capability for a nonsampling measurement of biomass in outdoor ponds. Other fitting parameters in the reflectance model are compared with auxiliary measurements and physics-based calculations. The model-derived magnitudes of sunlight and skylight water-surface reflections compare favorably with Fresnel reflectance calculations, while the model-derived quantum efficiency of Chl-a fluorescence is found to be in agreement with literature values. Finally, the water temperatures derived from the reflectance model exhibit excellent agreement with thermocouple measurements during the morning hours but correspond to significantly elevated temperatures in the afternoon hours. PMID:25321139

Reichardt, Thomas A; Collins, Aaron M; McBride, Robert C; Behnke, Craig A; Timlin, Jerilyn A

2014-08-20

402

Carotenoid biosynthesis in the primitive red alga Cyanidioschyzon merolae.  

PubMed

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 beta-carotene hydroxylase, were examined. C. merolae contains perhaps the simplest assortment of chlorophylls and carotenoids found in any eukaryotic photosynthetic organism: chlorophyll a, beta-carotene, and zeaxanthin. Carotenoids with epsilon-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 beta-ringed carotenoids when provided with lycopene as the substrate in Escherichia coli. Lycopene beta-ring cyclases from several bacteria, cyanobacteria, and land plants also proved to be high-fidelity enzymes, whereas the structurally related epsilon-ring cyclases from several plant species were found to be less specific, yielding products with beta-rings as well as epsilon-rings. C. merolae lacks orthologs of genes that encode the two types of beta-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 beta-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 beta-carotene hydroxylase therefore remains uncertain. PMID:17085635

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

2007-03-01

403

Glacial-interglacial environmental changes inferred from molecular and compound-specific ? 13C analyses of sediments from Sacred Lake, Mt. Kenya  

NASA Astrophysics Data System (ADS)

Molecular stratigraphic analyses, including lipid distributions and compound-specific ? 13C measurements, have been performed at 15 levels in a sediment core from Sacred Lake, Mt. Kenya, a high-altitude (2350 m a.s.l.) freshwater lake with a record extending from the last glacial (>40,000 cal. yr BP) through the present interglacial. Terrestrial and aquatic organic-matter sources were independently assessed using source-specific biomarkers. ? 13C values of long-chain n-alkyl lipids from terrestrial higher plants exhibit large glacial to interglacial shifts: those from the last glacial maximum (LGM) (-20 to -18‰) indicate a terrestrial vegetation dominated by C 4 grasses or sedges, whereas those from the early Holocene (-34 to -27‰) reflect recolonization of the catchment area by C 3 plants, consistent with a rapid rise in the upper treeline. Specific algal biomarkers, including five unsaturated hydrocarbons of novel structure ascribed to the microalga Botryococcus braunii, were abundant, as confirmed by scanning electronic microscopy (SEM). An extreme ? 13C shift of over 25‰ is displayed by the algal biomarkers, an elevated value of -5.1‰ at the last glacial maximum (LGM) contrasting with a minimum value of -30.3‰ at the beginning of the Holocene. A major change in the molecular distributions of the algal biomarkers parallels this large ? 13C shift, with acyclic isoprenoid hydrocarbons dominating the last glacial and cyclic isoprenoid hydrocarbons the Holocene. The low atmospheric partial pressure of CO 2 ( pCO 2) at the LGM would favour photosynthetic organisms possessing CO 2-concentrating mechanisms, including terrestrial C 4 grasses and freshwater green algae. Hence, glacial/interglacial changes in pCO 2, and in the CO 2:O 2 ratio in particular, had a significant impact on both terrestrial and aquatic ecosystems on Mt. Kenya, in addition to the effects of climate and local environmental factors.

Huang, Yongsong; Street-Perrott, F. Alayne; Perrott, R. Alan; Metzger, Pierre; Eglinton, Geoffrey

1999-05-01

404

El Niño evolution during the Holocene revealed by a biomarker rain gauge in the Galápagos Islands  

NASA Astrophysics Data System (ADS)

The El Niño-Southern Oscillation (ENSO) represents the largest perturbation to the climate system on an inter-annual time scale, but its evolution since the end of the last ice age remains debated due to the lack of unambiguous ENSO records lasting longer than a few centuries. Changes in the concentration and hydrogen isotope ratio of lipids produced by the green alga Botryococcus braunii, which blooms during El Niño rains in the Galápagos Islands, indicate that the early Holocene (9200-5600 yr BP) was characterized by alternating extremes in the intensity and/or frequency of El Niño events that lasted a century or more. Our data from the core of the ENSO region thus calls into question earlier studies that reported a lack of El Niño activity in the early Holocene. In agreement with other proxy evidence from the tropical Pacific, the mid-Holocene (5600-3500 yr BP) was a time of consistently weak El Niño activity, as were the Early Middle Ages (?1000-1500 yr BP). El Niño activity was moderate to high during the remainder of the last 3500 years. Periods of strong or frequent El Niño tended to occur during peaks in solar activity and during extended droughts in the United States Great Plains linked to La Niña. These changing modes of ENSO activity at millennial and multi-centennial timescales may have been caused by variations in the seasonal receipts of solar radiation associated with the precession of the equinoxes and/or changes in solar activity, respectively.

Zhang, Zhaohui; Leduc, Guillaume; Sachs, Julian P.

2014-10-01

405

Cytotoxic oxasqualenoids from the red alga Laurencia viridis.  

PubMed

Three new polyether squalene derivatives 15-dehydroxythyrsenol A (2), prethyrsenol A (3) and 13-hydroxyprethyrsenol A (4) have been isolated from the red alga Laurencia viridis. Their structures were determined through the interpretation of NMR spectroscopic data and chemical correlations. In addition, four semi-synthetic compounds modulating the solubility of the lead compound dehydrothyrsiferol (1) were prepared without loss of activity. The cytotoxicity of the new compounds exhibited low ?M activities. In order to explain their biological properties, docking simulations of the natural and synthetic compounds onto the ?v?3 integrin binding region were carried out. PMID:21616566

Cen-Pacheco, Francisco; Villa-Pulgarin, Janny A; Mollinedo, Faustino; Norte, Manuel; Daranas, Antonio H; Fernández, José J

2011-08-01

406

C 15 Acetogenins from the red alga Laurencia obtusa  

Microsoft Academic Search

Four C15 acetogenins, 13-epilaurencienyne (3Z) (1), 13-epipinnatifidenyne (3E) (2), (3E, 6S?, 7R?, 9S?, 10S?, 12R?)-9-chloro-13-bromo-6:12-epoxy-7, 10-diacetoxypentadec-3-en-1-yne (3), (3Z, 6S?, 7R?, 9S?, 10S?, 12R?)-9-chloro-13-bromo-6:12-epoxy-7, 10-diacetoxypentadec-3-en-1-yne (4), along with the known 13-epilaurencienyne (3E) (5), have been isolated from the organic extract of the red alga Laurencia obtusa, collected in the Aegean Sea, Greece. The structures of the new natural products, as well

Dimitra Iliopoulou; Constantinos Vagias; Catherine Harvala; Vassilios Roussis

2002-01-01

407

Cytotoxic halogenated metabolites from the Brazilian red alga Laurencia catarinensis.  

PubMed

Seven new (1-7) and seven previously reported (8-14) halogenated metabolites were isolated from the organic extract of the Brazilian red alga Laurencia catarinensis. The structure elucidation and the assignment of the relative configurations of the new natural products were based on detailed NMR and MS spectroscopic analyses, whereas the structure of metabolite 6 was confirmed by single-crystal X-ray diffraction analysis. The absolute configuration of metabolite 1 was determined using the modified Mosher's method. The in vitro cytotoxicity of compounds 1-14 was evaluated against HT29, MCF7, and A431 cell lines. PMID:20039643

Lhullier, Cintia; Falkenberg, Miriam; Ioannou, Efstathia; Quesada, Antonio; Papazafiri, Panagiota; Horta, Paulo Antunes; Schenkel, Eloir Paulo; Vagias, Constantinos; Roussis, Vassilios

2010-01-01

408

Sesquiterpenes from the marine red alga Laurencia composita.  

PubMed

Four new chamigrane derivatives, laurecomin A (1), laurecomin B (2), laurecomin C (3), and laurecomin D (4), one new naturally occurring sesquiterpene, 2,10-dibromo-3-chloro-7-chamigren-9-ol acetate (5), and three known halogenated structures, deoxyprepacifenol (6), 1-bromoselin-4(14),11-diene (7), and 9-bromoselin-4(14),11-diene (8), were isolated from the marine red alga Laurencia composita collected from Pingtan Island, China. The structures of these compounds were unambiguously established by 1D, 2D NMR and mass spectroscopic techniques. The bioassay results showed that 2 was active against both brine shrimp and fungus Colletotrichum lagenarium. PMID:22796401

Li, Xiao-Dong; Miao, Feng-Ping; Yin, Xiu-Li; Liu, Jia-Lin; Ji, Nai-Yun

2012-10-01

409

Bioactivities from Marine Algae of the Genus Gracilaria  

PubMed Central

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

de Almeida, Cynthia Layse F.; Falcao, Heloina de S.; Lima, Gedson R. de M.; Montenegro, Camila de A.; Lira, Narlize S.; de Athayde-Filho, Petronio F.; Rodrigues, Luis C.; de Souza, Maria de Fatima V.; Barbosa-Filho, Jose M.; Batista, Leonia M.

2011-01-01

410

Measuring Oscillatory Velocity Fields Due to Swimming Algae  

E-print Network

In this fluid dynamics video, we present the first time-resolved measurements of the oscillatory velocity field induced by swimming unicellular microorganisms. Confinement of the green alga C. reinhardtii in stabilized thin liquid films allows simultaneous tracking of cells and tracer particles. The measured velocity field reveals complex time-dependent flow structures, and scales inversely with distance. The instantaneous mechanical power generated by the cells is measured from the velocity fields and peaks at 15 fW. The dissipation per cycle is more than four times what steady swimming would require.

Guasto, Jeffrey S; Gollub, J P

2010-01-01

411

Dancing Volvox: Hydrodynamic Bound States of Swimming Algae  

E-print Network

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 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.

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

2009-01-14

412

Waltzing Volvox/: Orbiting Bound States of Flagellated Multicellular Algae  

NASA Astrophysics Data System (ADS)

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.

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

2008-11-01

413

Dancing Volvox: Hydrodynamic Bound States of Swimming Algae  

NASA Astrophysics Data System (ADS)

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.

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

2009-04-01

414

Uranium biosorption by Padina sp. algae biomass: kinetics and thermodynamics  

Microsoft Academic Search

Introduction  Kinetic, thermodynamic, and equilibrium isotherms of the biosorption of uranium ions onto Padina sp., a brown algae biomass, in a batch system have been studied.\\u000a \\u000a \\u000a \\u000a \\u000a Discussion  The kinetic data were found to follow the pseudo-second-order model. Intraparticle diffusion is not the sole rate-controlling\\u000a factor. The equilibrium experimental results were analyzed in terms of Langmuir isotherm depending with temperature. Equilibrium\\u000a data fitted

Mohammad Hassan Khani

415

Interaction of organic solvents with the green alga Chlorella pyrenoidosa  

SciTech Connect

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.

Stratton, G.W.; Smith, T.M. (Nova Scotia Agricultural College, Truro (Canada))

1988-06-01

416

Multidimensional electronic spectroscopy of phycobiliproteins from cryptophyte algae  

NASA Astrophysics Data System (ADS)

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.

Turner, Daniel

2011-03-01

417

Comprehensive guide to acetyl-carboxylases in algae.  

PubMed

Lipids from microalgae have become an important commodity in the last 20 years, biodiesel and supplementing human diets with ?-3 fatty acids are just two of the many applications. Acetyl-CoA carboxylase (ACCase) is a key enzyme in the lipid synthesis pathway. In general, ACCases consist of four functional domains: the biotin carboxylase (BC), the biotin carboxyl binding protein (BCCP), and ?-and ?-carboxyltransferases (?-and ?-CT). In algae, like in plants, lipid synthesis is another function of the chloroplast. Despite being well researched in plants and animals, there is a distinct lack of information about this enzyme in the taxonomically diverse algae. In plastid-containing organisms, ACCases are present in the cytosol and the plastid (chloroplasts) and two different forms exist, the heteromeric (prokaryotic) and homomeric (eukaryotic) form. Despite recognition of the existence of the two ACCase forms, generalized published statements still list the heteromeric form as the one present in algal plastids. In this study, the authors show this is not the case for all algae. The presence of heteromeric or homomeric ACCase is dependent on the origin of plastid. The authors used ACCase amino acid sequence comparisons to show that green (Chlorophyta) and red (Rhodophyta) algae, with the exception of the green algal class Prasinophyceae, contain heteromeric ACCase in their plastids, which are of primary symbiotic origin and surrounded by two envelope membranes. In contrast, algal plastids surrounded by three to four membranes were derived through secondary endosymbiosis (Heterokontophyta and Haptophyta), as well as apicoplast containing Apicomplexa, contain homomeric ACCase in their plastids. Distinctive differences in the substrate binding regions of heteromeric and homomeric ?-CT and ?-CT were discovered, which can be used to distinguish between the two ACCase types. Furthermore, the acetyl-CoA binding region of homomeric ?-CT can be used to distinguish between cytosolic and plastidial ACCase. The information provided here will be of fundamental importance in ACCase expression and activity research to unravel impacts of environmental and physicochemical parameters on lipid content and productivity. PMID:22524446

Huerlimann, Roger; Heimann, Kirsten

2013-03-01

418

The chemical constituents from red alga Gymnogongrus flabelliformis Harv.  

NASA Astrophysics Data System (ADS)

Eight compounds were isolated from red alga Gymnogongrus flabelliformis Harv. In normal phase silica gel, Sephadex LH-20 gel column chromatography, reverse phase HPLC, and recrystallization. Based on MS and 1D NMR spectroscopic data, their structures were determined as: stigmast-4-en-3-one (I), cholest-4-en-3-one (II), cholesterol (III), uracil (IV), uridine (V), adenosine (VI), succinic acid (VII), and 5-hydroxy-4-methyl-5-pentyl-2,5-dihydro-furan-2-on (VIII ). All of them were obtained from this species for the first time. Cytotoxicity of these compounds was screened using standard MTT method, but all the compounds were inactive (IC50 > 10 ?g/ml).

Yuan, Zhaohui; Han, Lijun; Su, Hua; Shi, Dayong; Sun, Jie; Li, Shuai; Shi, Jiangong

2008-05-01

419

Antiplasmodial halogenated monoterpenes from the marine red alga Plocamium cornutum.  

PubMed

In our continuing search for antimalarial leads from South African marine organisms we have examined the antiplasmodial organic extracts of the endemic marine red alga Plocamium cornutum (Turner) Harvey. Two new and three known halogenated monoterpenes were isolated and their structures determined by standard spectroscopic techniques. The 3,7-dimethyl-3,4-dichloro-octa-1,5,7-triene skeleton is common to all five compounds. Interestingly, compounds bearing the 7-dichloromethyl substituent showed significantly higher antiplasmodial activity toward a chloroquine sensitive strain of Plasmodium falciparum. PMID:19345384

Afolayan, Anthonia F; Mann, Maryssa G A; Lategan, Carmen A; Smith, Peter J; Bolton, John J; Beukes, Denzil R

2009-03-01

420

Numerical simulation of alga growth and control in Dalian Bay.  

PubMed

WAHMO model was used to simulate the distribution of pollutants in Dalian Bay, China as to predict well as the growth and control of alga. The observed and predicted values of main pollutants showed a good trend at all study locations and the different between them can be ignored. Simulation results illustrated that phosphate was one of limited factors to control algal growth at the location near the sewage outfall, meanwhile, away from the sewage outfall, the synergy of ammonium nitrogen and phosphate was the limited factor. PMID:25078837

Li, Ying; Huang, Caisheng; Zhou, Jiti

2013-12-01

421

Cadmium tolerance and adsorption by the marine brown alga Fucus vesiculosus from the Irish Sea and the Bothnian Sea  

E-print Network

Cadmium tolerance and adsorption by the marine brown alga Fucus vesiculosus from the Irish Sea vesiculosus Photosynthesis a b s t r a c t Cadmium (Cd) uptake capacities and Cd tolerance of the marine alga

Benning, Liane G.

422

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...

423

CHANGES IN QUANTUM YIELD OF PHOTOSYNTHESIS IN THE RED ALGA Porphyridium cruentum  

E-print Network

CHANGES IN QUANTUM YIELD OF PHOTOSYNTHESIS IN THE RED ALGA Porphyridium cruentum CAUSED BY STEPWISE From the Photosynthesis Research Laboratory, Botany Department, University of Illinois, Urbana. Dr of photosynthesis in the red alga Porphyridium cruentum, and the spectral compo- sition of light, changed

Govindjee

424

Green Pacific Biologicals Rapid & stable nuclear genetic engineering of eukaryotic algae  

E-print Network

to Investors · Rapid & stable nuclear genetic engineering of eukaryotic algae · WW exclusive license Max Planck's competitive advantage? Rapid & stable algae nuclear genetic engineering Wild-typeWild-typeWild-type GPBStrainGPBStrainGPBStrain #12;Green Pacific Biologicals Organism with high levels of oils Powerful genetic engineering GPB [no

425

The seasonal growth and succession of plankton algae in the White Nile  

Microsoft Academic Search

A description is given of the seasonal growth and succession, over five years, of plank- tonic algae in a region of the White Nile affected by a reservoir. Dense populations develop during the period of water storage, and are dominated by the diatom illelosira granulata and the blucgrcen alga Anabaena jlos aquae var. intermedia f. spiroides. The sequence of their

G. A. PROWE; J. F. TALLING

1958-01-01

426

Ingestion, assimilation, survival, and reproduction by Daphnia pulex fed seven species of blue-green algae  

Microsoft Academic Search

Daphnia p&x (Crustacea, Cladocera) was fed the blue-green algae (Cyanophyceae) Anacystis nidulans, Synechococcus elongata, S. cedrorum, Merismopedia sp., Anabaena flos- aquae, Synechocystis sp., and Gloeocapsa alpicola. The green algae ( Chlorophyceae) Ankis- trodesmus falcatus and Chlorella uulgaris were used for comparison. Direct observations were made of D. pulex feeding in depression slides filled with the test food. Food labeled with

DEAN E. ARNOLD

1971-01-01

427

Comparison of the content of heavy metals in brown algae and seagrasses  

Microsoft Academic Search

Brown algae and seagrasses (predominantly Zostracea) have been used for assessing environmental pollution with heavy metals for more than three decades [1, 2]. Algae and seagrasses grow on solid and soft grounds, respectively. In view of this, they are used as complementary accumulating biosentinel organisms that allow the quality of waters of littoral sea water areas with rocky and sandy

N. K. Khristoforova; E. N. Chernova

2005-01-01

428

A multi-locus time-calibrated phylogeny of the siphonous green algae  

Microsoft Academic Search

The siphonous green algae are an assemblage of seaweeds that consist of a single giant cell. They comprise two sister orders, the Bryopsidales and Dasycladales. We infer the phylogenetic relationships among the siphonous green algae based on a five-locus data matrix and analyze temporal aspects of their diversification using relaxed molecular clock methods calibrated with the fossil record. The multi-locus

Heroen Verbruggen; Matt Ashworth; Steven T. LoDuca; Caroline Vlaeminck; Ellen Cocquyt; Thomas Sauvage; Frederick W. Zechman; Diane S. Littler; Mark M. Littler; Frederik Leliaert; Olivier De Clerck

2009-01-01

429

Red Algae Lose Key Mitochondrial Genes in Response to Becoming Parasitic  

E-print Network

Red Algae Lose Key Mitochondrial Genes in Response to Becoming Parasitic Lillian Hancock1 , Lynda Red algal parasites are unusual because the vast majority of them parasitize species with which independently evolved hundreds of times among the floridiophyte red algae. Much is known about the life history

Lane, Chris

430

Resource demand implications for US algae biofuels production scale-up  

Microsoft Academic Search

Photosynthetic microalgae with the potential for high biomass and oil productivities have long been viewed as a promising class of feedstock for biofuels to displace petroleum-based transportation fuels. Algae offer the additional benefits of potentially being produced without using high-value arable land and fresh water, thereby reducing the competition for those resources between expanding biofuels production and conventional agriculture. Algae

Ron Pate; Geoff Klise; Ben Wu

2011-01-01

431

Combustion of algae oil methyl ester in an indirect injection diesel engine  

Microsoft Academic Search

An experimental study has been carried to use raw Algae oil and its methyl esters in an indirect injection diesel engine. Effects of engine speed, engine load output, injection timing of the algae biofuel and engine compression ratio on the engine output torque, combustion noise (maximum pressure rise rate), maximum pressure and maximum heat release rate have been studied. Raw

Yousef Haik; Mohamed Y. E. Selim; Tahir Abdulrehman

2011-01-01

432

Genome, Functional Gene Annotation, and Nuclear Transformation of the Heterokont Oleaginous Alga  

E-print Network

Genome, Functional Gene Annotation, and Nuclear Transformation of the Heterokont Oleaginous Alga University, East Lansing, Michigan, United States of America Abstract Unicellular marine algae have promise for providing sustainable and scalable biofuel feedstocks, although no single species has emerged as a preferred

Yandell, Mark

433

Pyrolytic characteristics and kinetic studies of three kinds of red algae  

Microsoft Academic Search

Marine algae have great potential as a third generation biofuel feedstock. The pyrolytic and kinetic characteristics of three kinds of red algae (Pophyra yezoensis, Plocamium telfairiae Harv and Corallina pilulifera) were studied at heating rates of 10, 30 and 50°Cmin?1 under an inert atmosphere. The most probable mechanism function and activation energy pre-exponential factors were calculated by the Popescu, FWO

Demao Li; Limei Chen; Xiaowen Zhang; Naihao Ye; Fuguo Xing

2011-01-01

434

Determination of bioactivity of chemical fractions of liquid wastes using freshwater and saltwater algae and crustaceans  

Microsoft Academic Search

Complex wastes from industrial and municipal outfalls were fractionated chemically and tested for toxicity with freshwater and saltwater algae and crustaceans. The organic fraction of each waste was subfractionated into acid-, base-, and neutral-extractable portions, and the inorganic fraction was subfractionated into its anion and cation components. All wastes affected growth of the algae Skeletonema costatum (saltwater) and Monoraphidium capricornutum

Gerald E. Walsh; Richard L. Garnas

1983-01-01

435

Are Algae Relevant to the Detritus-Based Food Web in Tank-Bromeliads?  

E-print Network

of the detrital food web in shaded bromeliads but accounted for up to 30 percent of the living microbial carbonAre Algae Relevant to the Detritus-Based Food Web in Tank-Bromeliads? Olivier Brouard1 , Anne and with regard to the structure of other aquatic microbial communities held in the tanks. Algae were retrieved

Boyer, Edmond

436

Sulfated Oligosaccharides Mediate the Interaction between a Marine Red Alga and Its Green Algal Pathogenic Endophyte  

Microsoft Academic Search

The endophytic green alga Acrochaete operculata completely colonizes the sporophytes of the red alga Chondrus cris- pus ; however, it does not penetrate beyond the outer cell layers of the gametophytes. Given that the life cycle phases of C. crispus differ in the sulfation pattern of their extracellular matrix carrageenans, we investigated whether carra- geenan fragments could modulate parasite virulence.

Kamal Bouarab; Philippe Potin; Juan Correa; Bernard Kloareg

1999-01-01

437

Some harmful algae produce potent toxins which cause illness or death in humans  

E-print Network

Issue Some harmful algae produce potent toxins which cause illness or death in humans and other organisms, including endangered species. Other harmful algae are non-toxic to humans and wildlife, recreation, and the culture of local tribes. Impacts of New England Red Tide on Commercial Fisheries in Maine

438

Food Preference of Fresh-Water Invertebrates - Comparing Fresh and Decomposed Angiosperm and a Filamentous Alga  

Microsoft Academic Search

1. Fresh and decomposed Mougeotia sp. (a filamentous green alga) and Elodea nuttallii (a vascular plant) were offered as food to three species of aquatic macroinvertebrates (Lymnnea peregra, Asellus meridianus and Endochironomus albipennis) to test: (i) if filamentous algae are preferred to aquatic higher plants (hereafter, called 'macrophytes') and (ii), as is known for higher plants, if decomposition also results

R. Kornijow; R. D. Gulati; T. Ozimek

1995-01-01

439

Closed and continuous algae cultivation system for food production and gas exchange in CELSS  

NASA Astrophysics Data System (ADS)

In CELSS (Controlled Ecological Life Support System), utilization of photosynthetic algae is an effective means for obtaining food and oxygen at the same time. We have chosen Spirulina, a blue-green alga, and have studied possibilities of algae utilization. We have developed an advanced algae cultivation system, which is able to produce algae continuously in a closed condition. Major features of the new system are as follows. o (1)In order to maintain homogeneous culture conditions, the cultivator was designed so as to cause a swirl on medium circulation. (2)Oxygen gas separation and carbon dioxide supply are conducted by a newly designed membrane module. (3)Algae mass and medium are separated by a specially designed harvester. (4)Cultivation conditions, such as pH, temperature, algae growth rate, light intensity and quanlity of generated oxygen gas are controlled by a computer system and the data are automatically recorded. This equipment is a primary model for ground experiments in order to obtain some design data for space use. A feasibility of algae cultivation in a closed condition is discussed on the basis of data obtained by use of this new system.

Oguchi, Mitsuo; Otsubo, Koji; Nitta, Keiji; Shimada, Atsuhiro; Fujii, Shigeo; Koyano, Takashi; Miki, Keizaburo

440

Marine Algae, Summer 2012 This is a course appropriate for marine biologists,  

E-print Network

to selected analytical gear (e.g., dissolved oxygen meters, nutrient analysis, and data loggersMarine Algae, Summer 2012 This is a course appropriate for marine biologists, botanists be found at http://depts.washington.edu/fhl/ A course in marine algae was first taught by T.C. Frye in 1904

Carrington, Emily

441

CONTRIBUTION TO THE KNOWLEDGE OF SOIL ALGAE OF TWO ABANDONED INDUSTRIAL  

E-print Network

CONTRIBUTION TO THE KNOWLEDGE OF SOIL ALGAE OF TWO ABANDONED INDUSTRIAL SEDIMENTATION BASINS Sixty three species of soil algae and Cyanoprocaryota were recovered from eight investigated sites indicates more alkaline conditions of the last locality. Extremely low al- gal abundance on the two treeless

442

Turf algae-mediated coral damage in coastal reefs of Belize, Central America.  

PubMed

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

Wild, Christian; Jantzen, Carin; Kremb, Stephan Georg

2014-01-01

443

Effectiveness and mechanism of potassium ferrate(VI) preoxidation for algae removal by coagulation.  

PubMed

Jar tests were conducted to evaluate the effectiveness of potassium ferrate preoxidation on algae removal by coagulation. Laboratory studies demonstrated that pretreatment with potassium ferrate obviously enhanced the algae removal by coagulation with alum [Al2(SO4)3 . 18H2O]. Algae removal efficiency increased remarkably when the water was pretreated with ferrate. A very short time of preoxidation was enough to achieve substantial algae removal efficiency, and the effectiveness was further increased at a prolonged pretreatment time. Pretreatment with ferrate resulted in a reduction of alum dosage required to cause an efficient coagulation for algae removal. The obvious impact of cell architecture by potassium ferrate was found through scanning electron microscopy. Upon oxidation with ferrate. the cells were inactivated and some intracellular and extracelluar components were released into the water, which may be helpful to the coagulation by their bridging effect. Efficient removal of algae by potassium ferrate preoxidation is believed to be a consequence of several process mechanisms. Ferrate preoxidation inactivated algae, induced the formation of coagulant aid, which are the cellular components secreted by algal cells. The coagulation was also improved by increasing particle concentration in water, because of the formation of the intermediate forms of precipitant iron species during preoxidation. In addition, it was also observed that ferrate preoxidation caused algae agglomerate formation before the addition of coagulant, the subsequent application of alum resulted in further coagulation. PMID:11848357

Ma, Jun; Liu, Wei

2002-02-01

444

Trace metals with seasonal considerations in coastal algae and molluscs from Beirut, Lebanon  

Microsoft Academic Search

Twelve species of intertidal algae and molluscs from Ras Beirut, Lebanon have been investigated for their heavy metal content. Atomic absorption spectrophotometric analysis showed that the algae and molluscs concentrated similar levels of most metals. However, of the twelve organisms, Brachydontes variabilis had the highest copper, Patella coerulea and Colpomenia sinuosa had the highest iron, and Pinctada radiata had the

J. G. Shiber

1980-01-01

445

J. Phycol. 37, 223234 (2001) PHOTOACCLIMATION IN THE TROPICAL CORALLINE ALGA HYDROLITHON ONKODES  

E-print Network

; photosynthesis; phycobilins; Rhodo- phyta Abbreviations: , initial slope; Pmax, maximal rate of photosynthesis work on the taxonomy of coralline algae, studies on these algae are sparse and deal mostly with ecology or calcification. Studies related to coral- line photosynthesis have mainly focused on primary production rates

California at Santa Barbara, University of

446

The Mediterranean red alga Asparagopsis: a source of compounds against Leishmania.  

PubMed

Crude extracts and column fractions from the red algae Asparagopsis taxiformis and A. armata from the Strait of Messina (Italy) were screened for the production of antimicrobial compounds. Extracts from both species revealed remarkable antiprotozoal activity against Leishmania, revealing such algae as a great source of natural antiprotozoal products. PMID:19841720

Genovese, Giuseppa; Tedone, Laura; Hamann, Mark T; Morabito, Marina

2009-01-01

447

The novel anti-Propionibacterium acnes compound, Sargafuran, found in the marine brown alga Sargassum macrocarpum  

Microsoft Academic Search

We screened extracts of 342 species of marine algae collected from Japanese coastlines for antibacterial activity against Propionibacterium acnes, and found a novel antibacterial compound, which we named Sargafuran, from the MeOH extract of the marine brown alga, Sargassum macrocarpum. Sargafuran has low cytotoxicity, and the MIC against P. acnes was 15 ?g ml?1, showing a broad antibacterial activity against

Yuto Kamei; Miyuki Sueyoshi; Ken-ichiro Hayashi; Ryuta Terada; Hiroshi Nozaki

2009-01-01

448

Preliminary survey of toxicity of the green alga Caulerpa taxifolia introduced into the Mediterranean  

Microsoft Academic Search

Caulerpa taxifolia (Vahl) C. Agardh (Ulvophyceae, Caulerpales) is an alga of tropical origin that was accidentally introduced into the Mediterranean sea in 1984, where this species can reach an abundance that has never been described in tropical endemic regions. It is known that caulerpacean algae can develop an efficient strategy against grazers consisting of the synthesis of repulsive of toxic

R. Lemée; D. Pesando; M. Durand-Clément; A. Dubreuil; A. Meinesz; A. Guerriero; F. Pietra

1993-01-01

449

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...

450

Water purification and recovery of fertilizer materials by blue green algae (Cyanobacteria). Final report  

Microsoft Academic Search

The object of this research project was to compare the water purification and recovery of fertilizer materials by blue green algae (Cyanobacteria) under thermal and non-thermal or ambient conditions. The thermal tests were conducted in a solar algae growth tank, in which a solar heat exchanger provided thermal conditions of 60 C during daytime hours. 6 figures, 1 table.

2008-01-01

451

Production and chlorophyll concentration of epipelic and epilithic algae in fertilized and nonfertilized subarctic lakes  

Microsoft Academic Search

The production and chlorophyll concentration of epipelic and epilithic algae was measured during four years (1972–1975) in two shallow, Swedish subarctic lakes. One lake (Lake Hymenjaure) was fertilized with phosphorus or a combination of phosphorus and nitrogen while the other (Lake Stugsjön) served as a reference. The benthic algae in both lakes were dominated by Cyanophyceae of the same species

Susanna Bjiirk-Ramberg; Claes Ånell

1985-01-01

452

Revisiting synchronous gamete release by fucoid algae in the intertidal zone: fertilization success and beyond?  

E-print Network

Revisiting synchronous gamete release by fucoid algae in the intertidal zone: fertilization success fertilization and settlement are critical processes linking adult and early juvenile life-history phases. This review focuses on synchronous gamete release (¼ spawning) in fucoid algae. These brown macroalgae

Teixeira, Sara

453

Combined Nitrogen and Phosphorus Fertilization for Controlling the Toxigenic Alga Prymnesium parvum  

Microsoft Academic Search

The toxigenic alga Prymnesium parvum has caused significant fish kills in Texas reservoirs and fish hatchery ponds since 2001. Copper sulfate and ammonium sulfate can control P. parvum, but they provide short-term improvement and have undesirable side effects. Copper sulfate also kills desirable algae and invertebrates, and ammonium sulfate can be harmful to fish. Because dominance of the phytoplankton community

Gerald L. Kurten; Aaron Barkoh; Loraine T. Fries; Drew C. Begley

2007-01-01

454

J. Phycol. 35, 2434 (1999) THE PHENOLOGY OF SEXUAL REPRODUCTION BY GREEN ALGAE (BRYOPSIDALES) ON  

E-print Network

24 J. Phycol. 35, 24­34 (1999) THE PHENOLOGY OF SEXUAL REPRODUCTION BY GREEN ALGAE (BRYOPSIDALES-specific patterns of synchronous gamete release by tropical green algae (Bryopsida- les) invite a variety of future, and color changes asso- ciated with fertility, data on gamete size and behav- ior, and descriptions

Clifton, Ken

455

Responses of stream algae to grazing minnows and nutrients: a field test for interactions  

Microsoft Academic Search

Previous studies have shown that an algivorous grazing minnow (Campostoma anomalum) is the major herbivore in Brier Creek, a hardwater stream in south central Oklahoma. In summer and autumn schools of Campostoma virtually eliminate algae from substrate surfaces in deeper areas of some pools. The pool-to-pool distributions of algae and Campostoma reported for this stream could occur if nutrient limitation

A. J. Stewart

1987-01-01

456

Facts about Cyanobacteria (Blue-green Algae) and Cyanobacterial Harmful Algal Blooms  

E-print Network

) and Cyanobacterial Harmful Algal Blooms (CyanoHABs) Cyanobacteria (blue-green algae) Cyanobacteria are bacteria smell bad. #12;2 Cyanobacterial harmful algal blooms (CyanoHABs) CyanoHABs are algae blooms, including North and South America, Africa, Australia, Europe, Scandinavia, and China. Cyanobacterial blooms

457

Turf algae-mediated coral damage in coastal reefs of Belize, Central America  

PubMed Central

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.

Jantzen, Carin; Kremb, Stephan Georg

2014-01-01

458

Biochemical and morphological characterization of sulfur-deprived and H 2 -producing Chlamydomonas reinhardtii (green alga)  

Microsoft Academic Search

Sulfur deprivation in green algae causes reversible inhibition of photosynthetic activity. In the absence of S, rates of photosynthetic O2 evolution drop below those of O2 consumption by respiration. As a consequence, sealed cultures of the green alga Chlamydomonas reinhardtii become anaerobic in the light, induce the \\

Liping Zhang; Thomas Happe; Anastasios Melis

2002-01-01

459

Molecular Characterization of Epiphytic Bacterial Communities on Charophycean Green Algae  

PubMed Central

Epiphytic bacterial communities within the sheath material of three filamentous green algae, Desmidium grevillii, Hyalotheca dissiliens, and Spondylosium pulchrum (class Charophyceae, order Zygnematales), collected from a Sphagnum bog were characterized by PCR amplification, cloning, and sequencing of 16S ribosomal DNA. A total of 20 partial sequences and nine different sequence types were obtained, and one sequence type was recovered from the bacterial communities on all three algae. By phylogenetic analysis, the cloned sequences were placed into several major lineages of the Bacteria domain: the Flexibacter/Cytophaga/Bacteroides phylum and the ?, ?, and ? subdivisions of the phylum Proteobacteria. Analysis at the subphylum level revealed that the majority of our sequences were not closely affiliated with those of known, cultured taxa, although the estimated evolutionary distances between our sequences and their nearest neighbors were always less than 0.1 (i.e., greater than 90% similar). This result suggests that the majority of sequences obtained in this study represent as yet phenotypically undescribed bacterial species and that the range of bacterial-algal interactions that occur in nature has not yet been fully described. PMID:9797295

Fisher, Madeline M.; Wilcox, Lee W.; Graham, Linda E.

1998-01-01

460

Marine algae and land plants share conserved phytochrome signaling systems  

PubMed Central

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. 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

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.

2014-01-01

461

Photosynthetic Hydrogen and Oxygen Production by Green Algae  

SciTech Connect

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.

Greenbaum, E.; Lee, J.W.

1999-08-22

462

Feeding by coral reef mesograzers: algae or cyanobacteria?  

NASA Astrophysics Data System (ADS)

Marine studies on herbivory have addressed the role of algae as food and shelter for small consumers, but the potential of benthic cyanobacteria to play similar roles is largely unknown. Here, feeding preferences were measured for eight invertebrate consumers from Guam, offered four common macroalgae and two cyanobacteria. The survivorship of another consumer raised on either macroalgae or cyanobacteria was also assessed. From the choices offered, the sacoglossans Elysia rufescens and E. ornata consumed the green macroalga Bryopsis pennata. The crab Menaethius monoceros preferred the red alga Acanthophora spicifera. The amphipods Parhyale hawaiensis and Cymadusa imbroglio consumed macroalgae and cyanobacteria in equivalent amounts, with C. imbroglio showing less selectivity among diets. In contrast to these patterns, in these assays the gastropods Stylocheilus striatus, Haminoea cymbalum, H. ovalis, and Haminoea sp. fed exclusively, or survived only, on cyanobacteria. Preferences for different cyanobacteria varied. Field surveys of cyanobacteria-associated species yielded 34 different invertebrate taxa and suggested different degrees of specificity in these associations. Tropical mesograzers exploit considerably different food resources, with some species adapted to consume cyanobacterial mats. Benthic cyanobacteria may play important roles as food and shelter for marine consumers and may indirectly influence local biodiversity through their associated fauna.

Cruz-Rivera, Edwin; Paul, Valerie J.

2006-11-01

463

Irradiance-mediated dimethylsulphoniopropionate (DMSP) responses of red coralline algae  

NASA Astrophysics Data System (ADS)

Red coralline algae produce significant quantities of dimethylsulphoniopropionate (DMSP), whose breakdown products include the important climate gas dimethylsulphide (DMS) but little is known about how environmental factors influence this DMS(P) production. The effect of photosynthetically active radiation (PAR) on intracellular DMS(P) concentrations in the red coralline algae Lithothamnion glaciale was investigated using short (30 min) and longer-term (up to 507 h) acclimatory responses and control and high-PAR light regimes. Longer-term acclimatory intracellular DMS(P) concentrations were significantly reduced following exposure to high-PAR (220-250 ?mol m -2 s -1). No short-term acclimatory effects were observed. We conclude that while DMS(P) content in L. glaciale does respond to changes in irradiance, the effect takes place over hours - days rather than minutes, suggesting a continued turnover of DMS(P) to combat oxidative stress induced by prolonged high-PAR exposure. Immediate short-term acclimatory responses do not appear to occur.

Rix, L. N.; Burdett, H. L.; Kamenos, N. A.

2012-01-01

464

Thiamine biosynthesis in algae is regulated by riboswitches  

PubMed Central

In bacteria, many genes involved in the biosynthesis of cofactors such as thiamine pyrophosphate (TPP) are regulated by ribo switches, regions in the 5? end of mRNAs to which the cofactor binds, thereby affecting translation and/or transcription. TPP riboswitches have now been identified in fungi, in which they alter mRNA splicing. Here, we show that addition of thiamine to cultures of the model green alga Chlamydomonas reinhardtii alters splicing of transcripts for the THI4 and THIC genes, encoding the first enzymes of the thiazole and pyrimidine branches of thiamine biosynthesis, respectively, concomitant with an increase in intracellular thiamine and TPP levels. Comparison with Volvox carteri, a related alga, revealed highly conserved regions within introns of these genes. Inspection of the sequences identified TPP riboswitch motifs, and RNA transcribed from the regions binds TPP in vitro. The THI4 riboswitch, but not the promoter region, was found to be necessary and sufficient for thiamine to repress expression of a luciferase-encoding reporter construct in vivo. The pyr1 mutant of C. reinhardtii, which is resistant to the thiamine analogue pyrithiamine, has a mutation in the THI4 riboswitch that prevents the THI4 gene from being repressed by TPP. By the use of these ribo switches, thiamine biosynthesis in C. reinhardtii can be effectively regulated at physiological concentrations of the vitamin. PMID:18093957

Croft, Martin T.; Moulin, Michael; Webb, Michael E.; Smith, Alison G.

2007-01-01

465

Interest of dynamic tests in acute ecotoxicity assessment in algae  

SciTech Connect

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.

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

1983-04-01

466

Polyploidy of endosymbiotically derived genomes in complex algae.  

PubMed

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

Hirakawa, Yoshihisa; Ishida, Ken-Ichiro

2014-04-01

467

Marine algae and land plants share conserved phytochrome signaling systems.  

PubMed

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. 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

Duanmu, Deqiang; Bachy, Charles; Sudek, Sebastian; Wong, Chee-Hong; Jiménez, 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

468

Halophytes, Algae, and Bacteria Food and Fuel Feedstocks  

NASA Technical Reports Server (NTRS)

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.

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

2009-01-01

469

Photosynthetic hydrogen and oxygen production by green algae  

SciTech Connect

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.

Greenbaum, E.; Lee, J.W.

1997-12-31

470

The effects of nutrient enrichment and herbivore abundance on the ability of turf algae to overgrow coral in the Caribbean.  

PubMed

Turf algae are multispecies communities of small marine macrophytes that are becoming a dominant component of coral reef communities around the world. To assess the impact of turf algae on corals, we investigated the effects of increased nutrients (eutrophication) on the interaction between the Caribbean coral Montastraea annularis and turf algae at their growth boundary. We also assessed whether herbivores are capable of reducing the abundance of turf algae at coral-algae boundaries. We found that turf algae cause visible (overgrowth) and invisible negative effects (reduced fitness) on neighbouring corals. Corals can overgrow neighbouring turf algae very slowly (at a rate of 0.12 mm 3 wk(-1)) at ambient nutrient concentrations, but turf algae overgrew corals (at a rate of 0.34 mm 3 wk(-1)) when nutrients were experimentally increased. Exclusion of herbivores had no measurable effect on the rate turf algae overgrew corals. We also used PAM fluorometry (a common approach for measuring of a colony's "fitness") to detect the effects of turf algae on the photophysiology of neighboring corals. Turf algae always reduced the effective photochemical efficiency of neighbouring corals, regardless of nutrient and/or herbivore conditions. The findings that herbivores are not capable of controlling the abundance of turf algae and that nutrient enrichment gives turf algae an overall competitive advantage over corals together have serious implications for the health of Caribbean coral reef systems. At ambient nutrient levels, traditional conservation measures aimed at reversing coral-to-algae phase shifts by reducing algal abundance (i.e., increasing herbivore populations by establishing Marine Protected Areas or tightening fishing regulations) will not necessarily reduce the negative impact of turf algae on local coral communities. Because turf algae have become the most abundant benthic group on Curaçao (and likely elsewhere in the Caribbean), new conservation strategies are required to mitigate their negative impact on coral communities. PMID:21179215

Vermeij, Mark J A; van Moorselaar, Imke; Engelhard, Sarah; Hörnlein, Christine; Vonk, Sophie M; Visser, Petra M

2010-01-01

471

Evaluation of the marine algae Ulva fasciata and Sargassum sp. for the biosorption of Cu(II) from aqueous solutions  

Microsoft Academic Search

In this study, the adsorption properties of two different marine algae (Ulva fasciata (green algae) and Sargassum sp. (brown algae)) were investigated. Equilibrium isotherms and kinetics were studied to evaluate the relative ability of the two algae to sequester Cu(II) from aqueous solutions. The maximum biosorption capacity obtained was 73.5mgg?1 for U. fasciata and 72.5mgg?1 for Sargassum sp. at a

S. Karthikeyan; R. Balasubramanian; C. S. P. Iyer

2007-01-01

472

Cultivation of nitrogen-fixing blue-green algae on ammonia-depleted effluents from sewage oxidation ponds  

Microsoft Academic Search

The data presented represent an initial, limited attempt on a small scale to cultivate nitrogen-fixing blue-green algae on both chemically defined media and low nitrogen sewage pond effluents. The rates of blue-green algal biomass production were low compared to those of green algae. Nevertheless, it appears that cultivation of nitrogen-fixing blue-green algae is possible on sewage effluents where these algae

J. C. Weissman; D. M. Eisenberg; J. R. Benemann

1978-01-01

473

The future viability of algae-derived biodiesel under economic and technical uncertainties.  

PubMed

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

Brownbridge, George; Azadi, Pooya; Smallbone, Andrew; Bhave, Amit; Taylor, Benjamin; Kraft, Markus

2014-01-01

474

Evolution and diversity of plant cell walls: from algae to flowering plants.  

PubMed

All photosynthetic multicellular Eukaryotes, including land plants and algae, have cells that are surrounded by a dynamic, complex, carbohydrate-rich cell wall. The cell wall exerts considerable biological and biomechanical control over individual cells and organisms, thus playing a key role in their environmental interactions. This has resulted in compositional variation that is dependent on developmental stage, cell type, and season. Further variation is evident that has a phylogenetic basis. Plants and algae have a complex phylogenetic history, including acquisition of genes responsible for carbohydrate synthesis and modification through a series of primary (leading to red algae, green algae, and land plants) and secondary (generating brown algae, diatoms, and dinoflagellates) endosymbiotic events. Therefore, organisms that have the shared features of photosynthesis and possession of a cell wall do not form a monophyletic group. Yet they contain some common wall components that can be explained increasingly by genetic and biochemical evidence. PMID:21351878

Popper, Zoë A; Michel, Gurvan; Hervé, Cécile; Domozych, David S; Willats, William G T; Tuohy, Maria G; Kloareg, Bernard; Stengel, Dagmar B

2011-01-01

475

The growth and distribution of the green alga Cladophora at Presqu'ile Provincial Park: Implications for management (Ontario)  

Microsoft Academic Search

The Green alga genus Caldophora is one of the most abundant kinds of algae worldwide, found in both freshwater and marine environments. It prefers nutrient-rich waters and requires a rocky substrate and water movement for growth. When water temperatures reach 22 to 26 C, the alga dies and washes into shore in large mats. Dead Cladophora produces a terrible odour,

Dolf Craig DeJong

2000-01-01

476

D-Amino Acid Utilization in Algae Jennifer Meoni1, Farrah Moazeni2, Gaosen Zhang, Ph.D.2,  

E-print Network

D-Amino Acid Utilization in Algae Jennifer Meoni1, Farrah Moazeni2, Gaosen Zhang, Ph.D.2, Henry Sun are derived primarily from cell wall (peptidoglycan) remnants of bacteria. Algae, which are composed environment so that we are not exposed. However, racemases are not known to be present in algae. So

Walker, Lawrence R.

477

DISTINCT PATTERNS OF NITRATE REDUCTASE ACTIVITY IN BROWN ALGAE: LIGHT AND AMMONIUM SENSITIVITY IN LAMINARIA DIGITATA IS ABSENT IN  

E-print Network

DISTINCT PATTERNS OF NITRATE REDUCTASE ACTIVITY IN BROWN ALGAE: LIGHT AND AMMONIUM SENSITIVITY and lowest in summer. This is the first report of NR activity in any alga that is not strongly regulated the regulation of NR by light that has been observed in other algae and higher plants. Key index words: ammonium

Berges, John A.

478

The Abundance, Habitat Selection, and Feeding Behavior of the Brittle Star, Ophioderma brevispinum, in Eelgrass-vs. Algae-  

E-print Network

, in Eelgrass- vs. Algae- Dominated Habitats in a Nutrient Enriched Estuary Amanda Keledjian Grinnell College to a shift from pristine eelgrass meadows to drifting algae mats that induce episodic hypoxia. To understand the lifestyle and role of this elusive animal, I sampled the abundance within eelgrass, algae, mud, and sandy

Vallino, Joseph J.

479

Effects of accumulations of sediments and drift algae on recruitment of sessile organisms associated with oyster reefs  

E-print Network

associated with oyster reefs M.S. Thomsen *, K. McGlathery Department of Environmental Science, P.O. Box algae (stress) affected recruitment of sessile oyster reef organisms, we constructed cages in Hog Island of the oyster Crassostrea virginica, the alien algae Gracilaria vermiculophylla and Codium fragile, the alga

McGlathery, Karen

480

Growth and photosynthetic response of a freshwater alga, Selenastrum capricornutum , to an oil shale by-product water  

Microsoft Academic Search

Several recent studies have focused on toxic effects of various oil shale waters to freshwater algae (e.g., Cleave et al. 1980; McKnight et al. 1983). Algal bioassays are ecologically significant, since algae are the dominant primary producers in most freshwater environments. Furthermore, algae have been shown to be more sensitive to complex wastes than fish or invertebrates. Using a standard

Damon Delistraty

1986-01-01

481

Plastid Genome Sequence of the Cryptophyte Alga Rhodomonas salina CCMP1319: Lateral Transfer of Putative DNA Replication Machinery and  

E-print Network

. Biochemical and molecular data indicate that cryptophyte plastids are derived from red algae, yet the question 2004; Rodriguez-Ezpeleta et al. 2005) and 3 modern-day eukaryotic lineages--red al- gae, green algae (Palmer 2003; Keeling 2004). More recently, the plastids of red and green algae have spread laterally

Archibald, John

482

Modulation of Light-Enhancement to Symbiotic Algae by Light-Scattering in Corals and Evolutionary Trends in  

E-print Network

Modulation of Light-Enhancement to Symbiotic Algae by Light-Scattering in Corals and Evolutionary that the cost of enhancing light-amplification to the algae is revealed in decreased resilience) Modulation of Light-Enhancement to Symbiotic Algae by Light-Scattering in Corals and Evolutionary Trends

Ottino, Julio M.

483

Fottea 8(2): 133146, 2008 133 Epipelic cyanobacteria and algae: a case study from Czech ponds  

E-print Network

Fottea 8(2): 133­146, 2008 133 Epipelic cyanobacteria and algae: a case study from Czech ponds Petr and algae (particularly desmids). Altogether 45 sediment samples were taken at ponds covering a p and various protozoa, feeding on epipelic algae (Amoeba, Urceolus cyclostomus). Key words: epipelon

484

International Journal of Systematic and Evolutionary Microbiology (2001), 51, 737749 Printed in Great Britain Phylogenetic relationships among algae based  

E-print Network

in Great Britain Phylogenetic relationships among algae based on complete large-subunit rRNA sequences 1 of the different groups of algae, and in particular to study the relationships among the different classes of heterokont algae. In LSU rRNA phylogenies, the chlorarachniophytes, cryptomonads and haptophytes seem to form

Gent, Universiteit

485

JENUFA GEN. NOV.: A NEW GENUS OF COCCOID GREEN ALGAE (CHLOROPHYCEAE, INCERTAE SEDIS) PREVIOUSLY RECORDED BY ENVIRONMENTAL SEQUENCING1  

E-print Network

JENUFA GEN. NOV.: A NEW GENUS OF COCCOID GREEN ALGAE (CHLOROPHYCEAE, INCERTAE SEDIS) PREVIOUSLY of unicellular green algae from algal biofilms growing on tree bark in a Southeast Asian tropical rainforest: AU, approximately unbiased; BBM, Bold basal medium; CAUP, Culture Collection of algae at Charles

486

Hyperbolic chemotaxis Hyperbolic chemotaxis on networks Models for biofilms Models for algae Some issues in the modeling of movement  

E-print Network

Hyperbolic chemotaxis Hyperbolic chemotaxis on networks Models for biofilms Models for algae Some issues in the modeling of movement of cells : chemotaxis, biofilms, algae, etc... Magali Ribot;Hyperbolic chemotaxis Hyperbolic chemotaxis on networks Models for biofilms Models for algae Hyperbolic

Ribot, Magali

487

ANSP Protocols for Analysis of NAWQA Algae Samples Protocol P-13-59 Patrick Center for Environmental Research 119  

E-print Network

ANSP Protocols for Analysis of NAWQA Algae Samples Protocol P-13-59 Patrick Center with the affected samples. #12;ANSP Protocols for Analysis of NAWQA Algae Samples Protocol P-13-59 120 Academy Protocols for Analysis of NAWQA Algae Samples Protocol P-13-59 Patrick Center for Environmental Research 121

Charles, Donald

488

Bacterial communities of some brown and red algae from Peter the Great Bay, the Sea of Japan  

Microsoft Academic Search

The structure of microbial communities of brown algae, red algae, and of the red alga Gracilaria verrucosa, healthy and affected with thallus rot, were comparatively investigated; 61 strains of heterotrophic bacteria were isolated\\u000a and characterized. Most of them were identified to the genus level, some Vibrio spp., to the species level according to their phenotypic properties and the fatty acid

I. A. Beleneva; N. V. Zhukova

2006-01-01

489

Relative roles of endolithic algae and carbonate chemistry variability in the skeletal dissolution of crustose coralline algae  

NASA Astrophysics Data System (ADS)

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.

Reyes-Nivia, C.; Diaz-Pulido, G.; Dove, S.

2014-09-01

490

Satellite-Observed Algae Blooms in China's Lake Taihu  

NASA Astrophysics Data System (ADS)

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.

Wang, Menghua; Shi, Wei

2008-05-01

491

Antithrombotic effects of bromophenol, an alga-derived thrombin inhibitor  

NASA Astrophysics Data System (ADS)

Thrombin, the ultimate proteinase of the coagulation cascade, is an attractive target for the treatment of a variety of cardiovascular diseases. A bromophenol derivative named (+)-3-(2,3-dibromo-4, 5-dihydroxy-phenyl)-4-bromo-5,6-dihydroxy-1,3-dihydroiso-benzofuran 1, isolated from the brown alga Leathesia nana exhibited significant thrombin inhibitory activity. In this study, we investigated the inhibition of human thrombin in vitro with this bromophenol derivative, and its antithrombotic efficacy in vivo using the arteriovenous shunt model and the ferric chloride-induced arterial thrombosis model in rats. The results show that the bromophenol derivative is a potential inhibitor of thrombin (IC50=1.03 nmol/L). In antithrombotic experiments in vivo, the bromophenol derivative also shows good effect comparing with the control group. These data indicate that the bromophenol derivative is a potential drug for prophylaxis and the treatment of thrombotic diseases.

Shi, Dayong; Li, Xiaohong; Li, Jing; Guo, Shuju; Su, Hua; Fan, Xiao

2010-01-01

492

[Response of siphoneal alga (Vaucheria sessilis) to the gravity factor].  

PubMed

Growth and development of siphonal alga Vaucheria sessilis under changed gravity and the role of cytoskeletal structures in gravitational response were studied. Hypergravity (3 g) and "hypogravity" were generated by slow clinostating at 7-8 rev/min and rapid clinostating at 35, 70, 135 rev/min, respectively. The experiments in microgravity were flown aboard biosatellite Bion-11. As was shown, V. sessilis responded to changed gravity by inhibition of rate of growth and increasing the number of nuclei in the strand as a result of activation of mitotic processes. Modulation of the course of the gravitational response with anticytoskeletal agents points to involvement of the cytoskeleton. The cortical circuit of actin microfilaments and the cytoplasm stream directed by this structure appear to be the most sensitive to changes in gravity. Gravity-sensitive V. sessilis is another promising object of research in the field of gravitational biology. PMID:10826062

Rudanova, E E; Gavrilova, O V; Voloshko, L N

2000-01-01

493

Genomic insights from the oleaginous model alga Nannochloropsis gaditana  

PubMed Central

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

Jinkerson, Robert E.; Radakovits, Randor; Posewitz, Matthew C.

2013-01-01