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1

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

PubMed Central

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

Hirose, Mana; Mukaida, Fukiko; Okada, Sigeru

2013-01-01

2

Release of single cells from the colonial oil-producing alga Botryococcus braunii by chemical treatments.  

PubMed

We tested for chemical reagents that would be useful in preparing a large number of vital single cells from colonial Botryococcus braunii B-race, variety Showa. Among the 18 reagents assayed, glycerol and erythritol showed the highest potency for releasing single cells. Incubation in medium containing these reagents released 40-50 % single cells in 15 min. Fluorescent staining with Nile red revealed that except for the cap-like structures the released single cells were free of hydrocarbon oils that accumulated in the extracellular matrix where the single cells were embedded. However, to maintain the prepared single cells in vital condition, they must be maintained at a high concentration (>2?×?10(7) cells/ml); at low concentrations, they rapidly lost chlorophyll and get disrupted. In contrast to the above results obtained using B-race, Showa, single cells prepared from A-race varieties survived even at low cell concentrations. PMID:23943006

Hou, Liyuan; Park, Hyunsun; Okada, Shigeru; Ohama, Takeshi

2014-01-01

3

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

4

Seawater-Cultured Botryococcus braunii for Efficient Hydrocarbon Extraction  

PubMed Central

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

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

2013-01-01

5

Structure-Function Mapping of Key Determinants for Hydrocarbon Biosynthesis by Squalene and Squalene Synthase-like Enzymes from the Green Alga Botryococcus braunii Race B.  

PubMed

Squalene and botryococcene are branched-chain, triterpene compounds that arise from the head-to-head condensation of two molecules of farnesyl diphosphate to yield 1'-1 and 1'-3 linkages, respectively. The enzymes that catalyze their formation have attracted considerable interest from the medical field as potential drug targets and the renewable energy sector for metabolic engineering efforts. Recently, the enzymes responsible for botryococcene and squalene biosynthesis in the green alga Botryococcus braunii race B were characterized. To better understand how the specificity for the 1'-1 and 1'-3 linkages was controlled, we attempted to identify the functional residues and/or domains responsible for this step in the catalytic cascade. Existing crystal structures for the mammalian squalene synthase and Staphylococcus dehydrosqualene synthase enzymes were exploited to develop molecular models for the B. braunii botryococcene and squalene synthase enzymes. Residues within the active sites that could mediate catalytic specificity were identified, and reciprocal mutants were created in an attempt to interconvert the reaction product specificity of the enzymes. We report here the identification of several amino acid positions contributing to the rearrangement of the cyclopropyl intermediate to squalene, but these same positions do not appear to be sufficient to account for the cyclopropyl rearrangement to give botryococcene. PMID:25393512

Bell, Stephen A; Niehaus, Thomas D; Nybo, S Eric; Chappell, Joseph

2014-12-01

6

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

7

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

E-print Network

Pilon's Lab ­ UCLA www.seas.ucla.edu/~pilon/ Refraction and absorption index of Botryococcus.seas.ucla.edu/~pilon/ Refraction and absorption index of Botryococcus braunii 8 9 10 11 12 13 14 15 0.000 0.005 0.010 0.015 0.020 0.025 0.030 0.035 0.040 0.045 0.050 Numberfrequency Equivalent diameter, ds (m) (nm) Refraction index, n

Pilon, Laurent

8

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

SciTech Connect

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

Metzger, P.; Allard, B.; Casadevall, E. (UA CNRS, Paris (France)); Berkaloff, C.; Coute, A. (LA CNRS, Paris (France))

1990-06-01

9

Application of memberane dispersion for enhanced lipid milking from Botryococcus braunii FACHB 357.  

PubMed

To improve the mixing efficiency in an aqueous-tetradecane system and thus to increase the lipid milking efficiency, poly (ether sulfones) hollow fiber membrane was applied as dispersion medium to establish an in situ lipid extraction process from Botryococcus braunii FACHB 357. The lipid location of this microalga was characterized by fluorescence microscope and transmission electron microscopy, respectively. The results showed that B. braunii excreted lipids into the outer matrix, which allowed it possible to extract algal lipids in situ by organic solvent. Within an aqueous-organic biphasic system, the lipid extraction ratio of tetradecane increased from 38.05% to 50.15% by introducing a microporous membrane as the dispersion medium, mainly because smaller solvent droplets were produced. Under this experimental condition (the volume ratio of tetradecane: 10%, the flow rate: 10 ml min(-1)), solvent toxicity and shearing stress had not shown significant impact on algal cells viability in 96 h. Within the same time period, the lipid amount extracted by solvent was enhanced with the increase of the solvent flow rate and the initial biomass concentration. These results suggested membrane dispersion was a good choice to improve mixing effect in the algal lipid milking process or other similar cell products extracted processes. PMID:23466999

Zhang, Fang; Cheng, Li-Hua; Xu, Xin-Hua; Zhang, Lin; Chen, Huan-Lin

2013-05-10

10

Effect of cobalt enrichment on growth and hydrocarbon accumulation of Botryococcus braunii with immobilized biofilm attached cultivation.  

PubMed

The effects of cobalt enrichment on the growth and hydrocarbon accumulation were studied with biofilm attached cultivation. Under biofilm attached cultivation conditions, the microalga Botryococcus braunii survived high concentration of cobalt (50× normal level). The crude hydrocarbon content as well as the long C chain component (C31) increased under Co enrichment treatment indicating the activity of key enzyme that catalyze hydrocarbon synthesis might be enhanced by Co enrichment. The reduced carbohydrate and protein contents accompanied by increased hydrocarbon content for Co enrichment treatment indicating the Co was also an effective factor that controls the carbon flow of B. braunii. Under Co enrichment treatment, totally 1473.9?mol of Co element was consumed to produce one gram of algal biomass, indicating this attached cultivation method is high efficient in heavy metal elements removal. PMID:25496939

Cheng, Pengfei; Wang, Junfeng; Liu, Tianzhong

2015-02-01

11

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

12

Simple, Rapid and Cost-Effective Method for High Quality Nucleic Acids Extraction from Different Strains of Botryococcus braunii  

PubMed Central

This study deals with an effective nucleic acids extraction method from various strains of Botryococcus braunii which possesses an extensive extracellular matrix. A method combining freeze/thaw and bead-beating with heterogeneous diameter of silica/zirconia beads was optimized to isolate DNA and RNA from microalgae, especially from B. braunii. Eukaryotic Microalgal Nucleic Acids Extraction (EMNE) method developed in this study showed at least 300 times higher DNA yield in all strains of B. braunii with high integrity and 50 times reduced working volume compared to commercially available DNA extraction kits. High quality RNA was also extracted using this method and more than two times the yield compared to existing methods. Real-time experiments confirmed the quality and quantity of the input DNA and RNA extracted using EMNE method. The method was also applied to other eukaryotic microalgae, such as diatoms, Chlamydomonas sp., Chlorella sp., and Scenedesmus sp. resulting in higher efficiencies. Cost-effectiveness analysis of DNA extraction by various methods revealed that EMNE method was superior to commercial kits and other reported methods by >15%. This method would immensely contribute to area of microalgal genomics. PMID:22662217

Kim, Byung-Hyuk; Ramanan, Rishiram; Cho, Dae-Hyun; Choi, Gang-Guk; La, Hyun-Joon; Ahn, Chi-Yong; Oh, Hee-Mock; Kim, Hee-Sik

2012-01-01

13

Development of a draft-tube airlift bioreactor for Botryococcus braunii with an optimized inner structure using computational fluid dynamics.  

PubMed

The key parameters of the inner structure of a cylindrical airlift bioreactor, including the ratio of the cross-section area of the downcomer to the cross-section area of the riser, clearance from the upper edge of the draft tube to the water level, and clearance from the low edge of the draft tube to the bottom of the reactor, significantly affected the biomass production of Botryococcus braunii. In order to achieve high algal cultivation performance, the optimal structural parameters of the bioreactor were determined using computational fluid dynamics (CFD) simulation. The simulated results were validated by experimental data collected from the microalgal cultures in both 2 and 40-L airlift bioreactors. The CFD model developed in this study provides a powerful means for optimizing bioreactor design and scale-up without the need to perform numerous time-consuming bioreactor experiments. PMID:22750496

Xu, Ling; Liu, Rui; Wang, Feng; Liu, Chun-Zhao

2012-09-01

14

Isolation of a Protein Containing Covalently Linked Large and Small Subunits of Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase from Botryococcus braunii.  

PubMed Central

Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and a 66-kD protein were co-purified from solubilized microsomal preparations of the green alga Botryococcus braunii by Green A agarose, sucrose density gradient, MonoQ, and gel filtration. The 66-kD protein remained intact after 6 M urea treatment and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. It could be detected in the soluble fraction of the cell-free extract but appeared to be more abundant in the microsomal preparations. It cross-reacted with antibodies raised against Rubisco holoenzyme, large and small subunits, indicating that the 66-kD protein contains both the large and the small subunits of Rubisco. The N-terminal amino acid sequence of this protein and that of a proteolytic fragment showed high homology with the mature Rubisco small subunits, and the sequence of another proteolytic fragment showed high homology with that of the Rubisco large subunit. It is concluded that the 66-kD protein is produced by cross-linking of large and small sub-units of Rubisco in the cell. PMID:12226300

Wang, X.; Kolattukudy, P. E.

1996-01-01

15

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

E-print Network

. braunii has a genome size of 166.0 +/- 0.4 Mb, which is similar to the B race, Berkeley strain, with a genome size of 166 +/- 2.2 Mb, while the L race, Songkla Nakarin strain, has a substantially larger genome size at 211.3 +/- 1.7 Mb. Phylogenetic...

Weiss, Taylor Leigh

2012-10-19

16

Gradient HPLC of samples extracted from the green microalga Botryococcus braunii using highly efficient columns packed with 2.6 ?m Kinetex-C?? core-shell particles.  

PubMed

The analysis of the nonpolar extract of the cells of colonies of the green colonial microalgae Botryococcus braunii was performed by gradient HPLC. The growth of B. braunii was stressed by reducing its nitrogen nutrients by 90%, in order to enhance the production of nonpolar compounds. Highly efficient 4.6mm × 100mm columns packed with 2.6 ?m Kinetex-C(18) core-shell particles (Phenomenex, Torrance, CA, USA) were used. The gradient mobile phase was a mixture of acetonitrile and water (70-97%, v/v). Its initial and final compositions during the gradient elution were chosen so that the retention factors of the last eluted compound at the inlet and outlet of the column were 15 and 1, respectively. The highest peak capacity was obtained by optimizing several experimental parameters, including the injected sample volume, the flow rate, and the column length. The highest resolution was obtained by connecting one 4.6 mm × 150 mm and three 4.6mm × 100mm columns (total length 45 cm). The optimum flow rate was 1.5 mL/min, which provided the minimum plate height for the most retained compounds, the optimum inlet pressure was 930 bar and the injected volume 2 ?L. The analysis time was then 14 min for a peak capacity of 121. The trends observed for the variation of the experimental peak capacity with the flow rate and the column length are in excellent agreement with theoretical predictions. PMID:22307155

Gritti, Fabrice; Perdu, Marie-Agnès; Guiochon, Georges

2012-03-16

17

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

SciTech Connect

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

Akin, C.; Pradhan, S. [Inst. of Gas Technology, Chicago, IL (United States)

1993-09-01

18

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

PubMed

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

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

2013-12-01

19

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

SciTech Connect

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

Akin, C.; Maka, A.; Patel, S.; Conrad, J. [Inst. of Gas Technology, Chicago, IL (United States); Benemann, J.

1993-12-31

20

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

PubMed Central

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

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

2013-01-01

21

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

22

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

SciTech Connect

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

Akin, C.; Maka, A.; Pradhan, S. [Institute of Gas Technology, Chicago, IL (United States); Banerjee, D. [Illinois Clean Coal Inst., Carterville, IL (United States)

1993-05-01

23

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

24

Radiation Characteristics of Botryococcus braunii, Chlorococcum littorale, and Chlorella sp. Used For CO2 Fixation and Biofuel Production  

E-print Network

weight concentration as functions of optical density (OD) atnm, OD Optical Density at 750 nm, OD (a) Concentration, X (concentrations were determined using calibration curves that relate the optical density (

Berberoglu, Halil; Gomez, Pedro; Pilon, Laurent

2009-01-01

25

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.

26

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

NASA Astrophysics Data System (ADS)

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

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

2010-05-01

27

Cytotaxonomical studies of West Bengal charophyta: Karyotype analysis in Chara braunii  

Microsoft Academic Search

The paper deals with cytotaxonomic studies of three forms ofChara braunii-f.coromandelina (n = 14), f.schweinitzii (n = 14) and f.kurzii (n = 28) from West Bengal (India). An improved technique involving the use of a pretreating agent permitted a detailed analysis of the karyotypes of the three taxa studied. It has been concluded that structural alterations of chromosomes and polyploidy

Probir Chatterjee

1976-01-01

28

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

29

Hydrocarbon phenotyping of algal species using pyrolysis-gas chromatography mass spectrometry  

PubMed Central

Background Biofuels derived from algae biomass and algae lipids might reduce dependence on fossil fuels. Existing analytical techniques need to facilitate rapid characterization of algal species by phenotyping hydrocarbon-related constituents. Results In this study, we compared the hydrocarbon rich algae Botryococcus braunii against the photoautotrophic model algae Chlamydomonas reinhardtii using pyrolysis-gas chromatography quadrupole mass spectrometry (pyGC-MS). Sequences of up to 48 dried samples can be analyzed using pyGC-MS in an automated manner without any sample preparation. Chromatograms of 30-min run times are sufficient to profile pyrolysis products from C8 to C40 carbon chain length. The freely available software tools AMDIS and SpectConnect enables straightforward data processing. In Botryococcus samples, we identified fatty acids, vitamins, sterols and fatty acid esters and several long chain hydrocarbons. The algae species C. reinhardtii, B. braunii race A and B. braunii race B were readily discriminated using their hydrocarbon phenotypes. Substructure annotation and spectral clustering yielded network graphs of similar components for visual overviews of abundant and minor constituents. Conclusion Pyrolysis-GC-MS facilitates large scale screening of hydrocarbon phenotypes for comparisons of strain differences in algae or impact of altered growth and nutrient conditions. PMID:20492649

2010-01-01

30

Algae Experiments  

NSDL National Science Digital Library

This two-part lesson offers students the opportunity to view two types of algae (freshwater and Great Salt Lake species) and assess the survival of each when placed in altered habitats. Students will make observations and record their observations on a recording sheet where they will describe what they see through drawing and words. They will help prepare slides of algae and will learn to identify different qualities such as cell structure, movement and other behavioristic qualities of the two different types of algae. The resource includes background knowledge, reference to Utah elementary core curriculum standards, prior resource assessment, reproducible handouts, materials list, teaching recommendations, and final assessment strategies.

Duffy, Kim; Project, Westminster C.

31

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.

Wim van Egmond

2010-01-01

32

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.

33

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

PubMed Central

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

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

2014-01-01

34

Algae Biodiesel: Commercialization  

E-print Network

Algae 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 replace petroleum #12;Project Overview: Local Resources for Algae Biodiesel Project Overview: Local

Tullos, Desiree

35

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

PubMed Central

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

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

1986-01-01

36

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

37

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

SciTech Connect

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

None

2010-07-01

38

Alkaloids in Marine Algae  

PubMed Central

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

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

2010-01-01

39

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

40

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

41

ALGAE AND WATER POLLUTION  

EPA Science Inventory

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

42

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

43

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,

44

Harmful Algae Digital Library  

NSDL National Science Digital Library

The Harmful Algae Digital Library contains a collection of Sea Grant documents in digital format (primarily PDF) arranged by subject area: red tide/PSP, brown tide, ciguatera, killer algae, and Pfiesteria. This collection is part of the National Sea Grant Library (NSGL), which maintains over 36,000 searchable records dedicated to environmental stewardship, long-term economic development and responsible use of America's coastal, ocean and Great Lakes resources.

Library, National S.; University Of Rhode Island-Bay Campus, Noaa

45

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,

46

TOXIC ALGAE IN SOUTHEASTERN AQUACULTURE SYSTEMS  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

47

Algal food selection and digestion by larvae of the pestiferous chironomid Chironomus Crassicaudatus under laboratory conditions.  

PubMed

Feeding preference of Chironomus crassicaudatus 4th instars when fed on 5 algal species, Anabaena flos-aquae, Botryococcus braunii, Lyngbia cf. aeruginosa, Microcystis sp., and Scenedesmus quadricauda was studied under laboratory conditions. The various algal species were mixed in pairs at 1:1 ratio (fresh weight) to create 10 possible test combinations. The larvae were allowed to feed individually for 8 h on each algal mixture in tissue culture plates having 4 replicates. Four identical algal mixtures were simultaneously used without larvae as controls. After feeding, larvae and excrement were removed, and remaining algae from feeding trials and controls were fixed with Lugol's solution; the final ratio of algal species in each mixture was determined microscopically. Feeding preferences of C. crassicaudatus early 4th instars, in descending order, was L. cf. aeruginosa, A. flos-aquae, B. braunii, Microcystis sp., and S. quadricaudata. To evaluate algal digestibility, larval excrement was collected and the proportion of live and dead cells was determined by microscopic observations with the use of visible and ultraviolet light (epifluorescence). Anabaena flos-aquae and L. cf. aeruginosa were the easiest to digest, followed by Microcystis sp. and S. quadricaudata, whereas no digestion of B. braunii was observed. Cultures of larval excrement revealed the presence of some viable cells of all 5 tested algal species. PMID:15669393

Frouz, Jan; Ali, Arshad; Lobinske, Richard J

2004-12-01

48

A Eurasian Alga in Alaska  

Microsoft Academic Search

Since it has not been report ed from other col­ lections of Alaskan algae, it may not occur out­ side of a limited area of the Bering Sea coast. Several mechanisms for the introduction of this algae into Izembek Lagoon can be con­ ceived. The most interesting is the possible introduction by the several hundred thou sand Stellar 's Eiders

PETER McRoy

49

Transgenic algae engineered for higher performance  

DOEpatents

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

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

2014-10-21

50

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

51

Shewanella algae in acute gastroenteritis.  

PubMed

Shewanella algae is an emerging bacteria rarely implicated as a human pathogen. Previously reported cases of S. algae have mainly been associated with direct contact with seawater. Here we report the isolation of S. algae as the sole etiological agent from a patient suffering from acute gastroenteritis with bloody diarrhoea. The bacterium was identified by automated identification system and 16S rRNA gene sequence analysis. Our report highlights the importance of looking for the relatively rare aetiological agents in clinical samples that does not yield common pathogens. It also underscores the usefulness of automated systems in identification of rare pathogens. PMID:25560029

Dey, S; Bhattacharya, D; Roy, S; Nadgir, S D; Patil, A; Kholkute, S D

2015-01-01

52

Logistic analysis of algae cultivation.  

PubMed

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

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

2015-03-01

53

Biological importance of marine algae  

PubMed Central

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

El Gamal, Ali A.

2009-01-01

54

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...

55

Characterization of algae using regularities.  

PubMed

The weight fraction carbon and reductance degree of algae are reviewed for literature data. Average values are compared with values for yeast and bacteria. The results show that the standard deviation and coefficient of variation are small as long as the algae are grown under adequate nutritional conditions. For nitrogen-deficient growth conditions, the storage of lipids has been observed; this results in values of weight fraction carbon and reductance degree which are larger than the average values. PMID:18553443

Lee, H Y; Erickson, L E

1984-07-01

56

A comparative study of fossil and extant algaenans using ruthenium tetroxide degradation  

NASA Astrophysics Data System (ADS)

In this study the chemical structure of algaenans isolated from the freshwater algae Tetraedron minimum, Pediastrum boryanum and Botryococcus braunii are compared with their fossil counterparts by means of RuO 4 oxidation. The results show that the algaenans investigated are preserved in sediments with only minor structural alterations. However, product mixtures from RuO 4 degradation of the fossil algaenans exhibit a broader distribution of oxidation products than freshly isolated algaenans indicating that the fossil biopolymers contain a greater proportion of ether cross-links, which maybe an effect of diagenetic alteration or different algal strains. Despite these differences, fossil algaenans can still be recognised chemically on the basis of the specific RuO 4 oxidation products, even after 50 Ma of sediment burial.

Blokker, Peter; Schouten, Stefan; de Leeuw, Jan W.; Sinninghe Damsté, Jaap S.; van den Ende, Herman

2000-06-01

57

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

58

Microscopic Gardens: A Close Look at Algae.  

ERIC Educational Resources Information Center

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

Foote, Mary Ann

1983-01-01

59

Plant biomechanics: High-endurance algae  

NASA Astrophysics Data System (ADS)

Breaking waves place repeated loading on marine algae, which can lead to death by fatigue. But observations of one alga suggest that its joint structure, which lacks transverse connections, confers fatigue resistance.

Carrington, Emily

2013-11-01

60

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.

61

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

62

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

63

Complexation of lead with unicellular algae exudates  

Microsoft Academic Search

Release of exudates by freshwater algae may be different in polluted and non?polluted waters. The purpose of this work is to study the effect of lead on the unicellular green algae (Selenstrum capricornutum Printz), to find out if algae develop some defence mechanism against lead toxicity.Complexation studies were done in lead contaminated and uncontaminated (control) cultures, in exponential and stationary

Sofia Capelo; Ana M. Mota; Maria L. S. Gonçalves

1999-01-01

64

21 CFR 184.1121 - Red algae.  

Code of Federal Regulations, 2013 CFR

...Drugs 3 2013-04-01 2013-04-01 false Red algae. 184.1121 Section 184.1121 Food and...Specific Substances Affirmed as GRAS § 184.1121 Red algae. (a) Red algae are seaweeds of the species Gloiopeltis...

2013-04-01

65

21 CFR 184.1121 - Red algae.  

Code of Federal Regulations, 2014 CFR

...Drugs 3 2014-04-01 2014-04-01 false Red algae. 184.1121 Section 184.1121 Food and...Specific Substances Affirmed as GRAS § 184.1121 Red algae. (a) Red algae are seaweeds of the species Gloiopeltis...

2014-04-01

66

21 CFR 184.1121 - Red algae.  

Code of Federal Regulations, 2011 CFR

...Drugs 3 2011-04-01 2011-04-01 false Red algae. 184.1121 Section 184.1121 Food and...Specific Substances Affirmed as GRAS § 184.1121 Red algae. (a) Red algae are seaweeds of the species Gloiopeltis...

2011-04-01

67

21 CFR 184.1121 - Red algae.  

Code of Federal Regulations, 2010 CFR

...Drugs 3 2010-04-01 2009-04-01 true Red algae. 184.1121 Section 184.1121 Food and...Specific Substances Affirmed as GRAS § 184.1121 Red algae. (a) Red algae are seaweeds of the species Gloiopeltis...

2010-04-01

68

21 CFR 184.1121 - Red algae.  

Code of Federal Regulations, 2012 CFR

...Drugs 3 2012-04-01 2012-04-01 false Red algae. 184.1121 Section 184.1121 Food and...Specific Substances Affirmed as GRAS § 184.1121 Red algae. (a) Red algae are seaweeds of the species Gloiopeltis...

2012-04-01

69

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.

70

Glycolate Pathway in Algae 1  

PubMed Central

No glycolate oxidase activity could be detected by manometric, isotopic, or spectrophotometric techniques in cell extracts from 5 strains of algae grown in the light with CO2. However, NADH:glyoxylate reductase, phosphoglycolate phosphatase and isocitrate dehydrogenase were detected in the cell extracts. The serine formed by Chlorella or Chlamydomonas after 12 seconds of photosynthetic 14CO2 fixation contained 70 to 80% of its 14C in the carboxyl carbon. This distribution of label in serine was similar to that in phosphoglycerate from the same experiment. Thus, in algae serine is probably formed directly from phosphoglycerate. These results differ from those of higher plants which form uniformly labeled serine from glycolate in short time periods when phosphoglycerate is still carboxyl labeled. In glycolate formed by algae in 5 and 10 seconds of 14CO2 fixation, C2 was at least twice as radioactive as C1. A similar skewed labeling in C2 and C3 of 3-phosphoglycerate and serine suggests a common precursor for glycolate and 3-phosphoglycerate. Glycine formed by the algae, however, from the same experiments was uniformly labeled. Manganese deficient Chlorella incorporated only 2% of the total 14CO2 fixed in 10 minutes into glycolate, while in normal Chlorella 30% of the total 14C was found in glycolate. Manganese deficient Chlorella also accumulated more 14C in glycine and serine. Glycolate excretion by Chlorella was maximal in 10 mm bicarbonate and occurred only in the light, and was not influenced by the addition of glycolate. No time dependent uptake of significant amounts of either glycolate or phosphoglycolate was observed. When small amounts of glycolate-2-14C were fed to Chlorella or Scenedesmus, only 2 to 3% was metabolized after 30 to 60 minutes. The algae were not capable of significant glycolate metabolism as is the higher plant. The failure to detect glycolate oxidase, the low level glycolate-14C metabolism, and the formation of serine from phosphoglycerate rather than from glycolate are consistent with the concept of an incomplete glycolate pathway in algae. PMID:6045296

Hess, J. L.; Tolbert, N. E.

1967-01-01

71

The remote sensing of algae  

NASA Technical Reports Server (NTRS)

State agencies need rapid, synoptic and inexpensive methods for lake assessment to comply with the 1972 Amendments to the Federal Water Pollution Control Act. Low altitude aerial photography may be useful in providing information on algal type and quantity. Photography must be calibrated properly to remove sources of error including airlight, surface reflectance and scene-to-scene illumination differences. A 550-nm narrow wavelength band black and white photographic exposure provided a better correlation to algal biomass than either red or infrared photographic exposure. Of all the biomass parameters tested, depth-integrated chlorophyll a concentration correlated best to remote sensing data. Laboratory-measured reflectance of selected algae indicate that different taxonomic classes of algae may be discriminated on the basis of their reflectance spectra.

Thorne, J. F.

1977-01-01

72

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.

73

Algae control for hydrogeneration canals  

SciTech Connect

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

Grahovac, P.

1997-02-16

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

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

76

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

77

BOTANICAL BRIEFING Streptophyte algae and the origin of embryophytes  

E-print Network

BOTANICAL BRIEFING Streptophyte algae and the origin of embryophytes Burkhard Becker* and Birger March 2009 Background Land plants (embryophytes) evolved from streptophyte green algae, a small group of freshwater algae ranging from scaly, unicellular flagellates (Mesostigma) to complex, filamentous thalli

78

FAS4932: ALGAE BIOLOGY AND ECOLOGY Instructor: Professor Edward Phlips  

E-print Network

FAS4932: ALGAE BIOLOGY AND ECOLOGY Instructor: Professor Edward Phlips Main Office: Program algae, including evolution, classification, structure, photosynthesis, growth, and reproduction. Emphasis on the ecological role of algae in different aquatic ecosystems (e.g. open ocean, estuaries, coral

Watson, Craig A.

79

Introduction slide 2 Biofuels and Algae Markets, Systems,  

E-print Network

Introduction slide 2 Biofuels and Algae Markets, Systems, Players and Commercialization Outlook: A Global Market Survey (2008) Algae 2020: Biofuels Commercialization Outlook (2009) Columnist, Biofuels, Castor, Yellow Grease, Fats 2nd Generation Projects and Trends Algae, Renewable Diesel, Bio

80

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

81

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

82

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

83

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

84

Effects of the potential allelochemical ?-asarone on growth, physiology and ultrastructure of two unicellular green algae  

Microsoft Academic Search

The effects of the natural phenylpropanoid ?-asarone on growth pattern, photosynthesis, respiration and cell structure of two microalgae have been investigated. In cultures ofAnkistrodesmus braunii ?-asarone decreases in the medium and induces a lag in growth. Both phenomena were dependent on the number of cells inoculated. By contrast, in cultures ofSelenastrum capricornutum a constant decrease of the growth rate at

Antonino Pollio; Gabriele Pinto; Roberto Ligrone; Giovanni Aliotta

1993-01-01

85

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

86

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-studied ETIs is the origin of multicellularity in the green alga Volvox, a model system for the evolution occurred dozens of times independently, for example in the red algae, brown algae, land plants, animals

87

21 CFR 73.275 - Dried algae meal.  

Code of Federal Regulations, 2014 CFR

...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

88

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

89

CEC-500-2010-FS-001 Algae OMEGA  

E-print Network

CEC-500-2010-FS-001 Algae OMEGA (Offshore Membrane Enclosures For Growing Algae) TRANSPORTATION conditions but, to date, there are no algae cultivation methods on land that meet these requirements of scale will demonstrate the feasibility of NASA Ames's Offshore Membrane Enclosures for Growing Algae (OMEGA) system

90

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

91

Analysis of Land Suitable for Algae State of Hawaii  

E-print Network

Analysis of Land Suitable for Algae Production State of Hawaii Prepared by Mele Chillingworth Scott 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 production

92

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

93

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

94

Chemoreception in the green alga Dunaliella tertiolecta  

Microsoft Academic Search

A capillary assay was employed to quantify positive chemotactic responses in the motile, unicellular, marine algaDunaliella tertiolecta. Among a wide range of inorganic and organic compounds tested, only ammonium ion,l-tyrosine,l-tryptophan, andl-phenylalanine were found to be major atractants for the chlorophyte.l-Methionine andl-cysteine weakly attracted the alga at 10?3 M. The minimum concentration of the major attractants needed to elicit an observable

Roy D. Sjoblad; Ilan Chet; Ralph Mitchellw

1978-01-01

95

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

96

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

97

Estimation of alga growth stage and lipid content growth rate  

NASA Technical Reports Server (NTRS)

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

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

2012-01-01

98

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

99

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

100

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

101

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

102

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

103

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

104

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

105

[Accumulation of polycyclic arenes in Baltic Sea algae].  

PubMed

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

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

1985-01-01

106

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)...

107

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. ...

108

MANOMETRIC MEASUREMENTS OF PHOTOSYNTHESIS IN THE MARINE ALGA GIGARTINA  

PubMed Central

A manometric method for measuring photosynthesis in marine algae is described. Photosynthesis in the red alga Gigartina harveyana is shown to be similar in all important respects to photosynthesis in Chlorella and other Chlorophyceae. PMID:19872816

Emerson, Robert; Green, Lowell

1934-01-01

109

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...

110

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

111

Battling golden algae: Results suggest preventative lake managment approaches  

E-print Network

14 tx H2O Winter 2011 Story by Danielle Supercinski Battling golden algae Results suggest preventative lake management approaches Golden algae blooms, or the explosive growth of algae, are known to be toxic, but recent #28;ndings from... and then ending in late winter or spring,? Grover said. ?P. parvum populations are consistently low during summer. In contrast, laboratory growth 16 tx H2O Winter 2011 Battling golden algae Continued Through previous funding, researchers conducted in...

Supercinski, Danielle

2011-01-01

112

Battling Golden Algae: Results suggest preventative lake management approaches  

E-print Network

14 tx H2O Winter 2011 Story by Danielle Supercinski Battling golden algae Results suggest preventative lake management approaches Golden algae blooms, or the explosive growth of algae, are known to be toxic, but recent #28;ndings from... and then ending in late winter or spring,? Grover said. ?P. parvum populations are consistently low during summer. In contrast, laboratory growth 16 tx H2O Winter 2011 Battling golden algae Continued Through previous funding, researchers conducted in...

Supercinski, Danielle

2011-01-01

113

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

114

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

115

Analysis of Land Suitable for Algae State of Hawaii  

E-print Network

Analysis 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 University of Hawaii at Manoa August 2011 #12;i Executive Summary Algae are considered to be a viable crop

116

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).

117

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

118

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

119

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 the expression of genes. In this introductory manuscript, I discuss select algae and how genomics is impacting our understanding of these organisms. Four algae for which near-full genome information has become

120

FAS6932: ALGAE BIOLOGY AND ECOLOGY Instructor: Professor Edward Phlips  

E-print Network

FAS6932: ALGAE BIOLOGY AND ECOLOGY Instructor: Professor Edward Phlips Main Office: Program-mail: phlips@ufl.edu Office Hours: Mondays 4pm-5pm Course Description: The biology and ecology of aquatic algae on the ecological role of algae in different aquatic ecosystems (e.g. open ocean, estuaries, coral reefs, rocky

Watson, Craig A.

121

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.

122

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

123

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

124

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

125

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.

126

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.

127

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

128

Polyamine biosynthetic diversity in plants and algae.  

PubMed

Polyamine biosynthesis in plants differs from other eukaryotes because of the contribution of genes from the cyanobacterial ancestor of the chloroplast. Plants possess an additional biosynthetic route for putrescine formation from arginine, consisting of the enzymes arginine decarboxylase, agmatine iminohydrolase and N-carbamoylputrescine amidohydrolase, derived from the cyanobacterial ancestor. They also synthesize an unusual tetraamine, thermospermine, that has important developmental roles and which is evolutionarily more ancient than spermine in plants and algae. Single-celled green algae have lost the arginine route and are dependent, like other eukaryotes, on putrescine biosynthesis from the ornithine. Some plants like Arabidopsis thaliana and the moss Physcomitrella patens have lost ornithine decarboxylase and are thus dependent on the arginine route. With its dependence on the arginine route, and the pivotal role of thermospermine in growth and development, Arabidopsis represents the most specifically plant mode of polyamine biosynthesis amongst eukaryotes. A number of plants and algae are also able to synthesize unusual polyamines such as norspermidine, norspermine and longer polyamines, and biosynthesis of these amines likely depends on novel aminopropyltransferases similar to thermospermine synthase, with relaxed substrate specificity. Plants have a rich repertoire of polyamine-based secondary metabolites, including alkaloids and hydroxycinnamic amides, and a number of polyamine-acylating enzymes have been recently characterised. With the genetic tools available for Arabidopsis and other model plants and algae, and the increasing capabilities of comparative genomics, the biological roles of polyamines can now be addressed across the plant evolutionary lineage. PMID:20227886

Fuell, Christine; Elliott, Katherine A; Hanfrey, Colin C; Franceschetti, Marina; Michael, Anthony J

2010-07-01

129

OPTIMAL COST CONTROL STRATEGIES FOR ATTACHED ALGAE  

EPA Science Inventory

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

130

Indigenous algae: Potential factories for biodiesel production  

Microsoft Academic Search

1. Abstract The environmental effects of burning fossil fuels and the increased crude oil prices have triggered increased interest in biofuels. Biodiesel is traditionally produced from oil seed crops, which have lower yields per land area and threaten food security when compared to algae which have high oil yields (~ 90 times more oil per area of land in comparison

DM MAHARAJH; R LALLOO

131

There Are Algae in Your House!  

NSDL National Science Digital Library

This lesson plan provides an activity in which students can learn about how algae is used in the food they eat. The lesson plan includes background information as well as instructions for in-class and take-home parts of the activity.

Nalker, Beth; Casey, Doug; Smithsonian, Ocean P.

132

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

133

Characterization of Tertiary Catalan lacustrine oil shales: Discovery of extremely organic sulphur-rich Type I kerogens  

NASA Astrophysics Data System (ADS)

The kerogens of three Tertiary Catalan lacustrine oil shales were analyzed by light microscopy, flash pyrolysis-gas chromatography-mass spectrometry, and bulk composition methods (elemental analysis, Rock Eval pyrolysis). Two of the three kerogens (Ribesalbes and Campins) are extremely rich in organic sulphur (atomic S org/C ratio > 0.04) and hydrogen (atomic ratio H/C ratio > 1.5) and are, consequently, classified as Type I-S kerogens. Very characteristic distribution patterns of flash pyrolysis products (e.g., alkan-9- and -10-ones, alkadienes) of the Ribesalbes kerogen revealed that it is predominantly composed of fossilized organic matter of the freshwater alga Botryococcus braunii. These two findings demonstrate that sulphurization of organic matter may also occur in lacustrine sediments provided that sulphate is supplied by external sources. Data on the third kerogen sample (Cerdanya) suggest that the freshwater alga Pediastrum may contain a (partly) aromatic biomacromolecule that is selectively preserved upon diagenesis. These findings testify to the large variability in palaeodepositional conditions in lacustrine environments. A comparison of the biomarker composition of the extract of the Ribesalbes oil shale with the kerogen composition indicate that biomarkers often cannot be used to assess the major sources of organic matter in such settings. A similar conclusion can be drawn from a comparison of literature data concerning the Messel Oil Shale.

Sinninghe Damsté, Jaap S.; de las Heras, F. Xavier C.; van Bergen, Pim F.; de Leeuw, Jan W.

1993-01-01

134

Characterization of Tertiary Catalan lacustrine oil shales: Discovery of extrmely organic sulphur-rich Type I kerogens  

SciTech Connect

The kerogens of three Tertiary Catalan lacustrine oil shales were analyzed by light microscopy, flash pyrolysis-gas chromatography-mass spectrometry, and bulk composition methods (elemental analysis, Rock Eval pyrolysis). Two of the three kerogens (Ribesalbes and Campins) are extremely rich in organic sulfur (atomic S[sub org]/C ratio > 0.04) and hydrogen (atomic ratio H/C ratio > 1.5) and are, consequently, classified as Type I-S kerogens. Very characteristic distribution patterns of flash pyrolysis products (e.g., alkan-9- and -10-ones, alkadienes) of the Ribesalbes kerogen revealed that it is predominantly composed of fossilized organic matter of the freshwater alga Botryococcus braunii. These two findings demonstrate that sulfurization of organic matter may also occur in lacustrine sediments provided that sulfate is supplied by external sources. Data on the third kerogen sample (Cerdanya) suggest that the freshwater alga Pediastrum may contain a (partly) aromatic biomacromolecule that is selectively preserved upon diagenesis. These findings testify to the large variability in palaeodepositional conditions in lacutrine environments. A comparison of the biomarker composition of the extract of the Ribesalbes oil shale with the kerogen composition indicate that biomarkers often cannot be used to assess the major sources of organic matter in such settings. A similar conclusion can be drawn from a comparison of literature data concerning the Messel Oil Shale. 75 refs., 18 figs., 7 tabs.

Sinninghe Damste, J.S.; Heras, F.X.C. De Las; Bergen, P.F. Van; Leeuw, J.W. De (Delft Univ. of Technology (Netherlands))

1993-01-01

135

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

136

Toxicity of chlorinated benzenes to marine algae  

NASA Astrophysics Data System (ADS)

Growth of Chlorella marine, Nannochloropsis oculata, Pyramidomonas sp., Platymonas subcordiformis and Phaeodactylum tricornutum exposed to monochlorobenzene (MCB), 1,2-dichlorobenzene (1,2-DCB), 1, 2, 3, 4-tetrachlorobenzene (1, 2, 3, 4-TeCB) and pentachlorobenzene (PeCB) was tested. Tests of 72 h- EC 50 values showed that the toxicity ranged in the order: MCB<1,2-DCB<1,2,3,4-TeCBalgae was almost in the order: Pyramidomonas sp. < Platymonas subcordiformis < Nannochloropsis oculata < Chlorella marine < Phaeodactylum tricomutum. Study of the QSAR (Quantitative Structure-Activity Relationship) between K OW and toxicity of CBs to marine algae showed good relationships between -log EC 50 and log K OW.

Ma, Yan-Jun; Wang, Xiu-Lin; Yu, Wei-Jun; Zhang, Li-Jun; Sun, Han-Zhang

1997-12-01

137

Bioconcentration of tetrachlorobenzene in marine algae  

NASA Astrophysics Data System (ADS)

Bioconcentration of tetrachlorobenzene (TeCB) in Chlorella marine, Nannochloropsis oculata, Pyramidomonas sp., Platymonas subcordiformis, and Phaeodactylum tricornutum; and toxicity of TeCB to the marine algae were tested. Values of bioconcentration potential parameters, including uptake rate constant k 1, elimination rate constant k 2 and bioconcentration factor BCF, were obtained not only from the time course of TeCB uptake by the marine algae by using a bioconcentration model, but also from the acute toxicity test data for percent inhibition PI(%)˜exposure concentration of TeCB-time by using a combined bioconcentration and probability model. The results showed good relationship between k 1(TOXIC) and k 1(UPTAKE) and k 2(TOXIC), k 2(UPTAKE), and BCF D(IOXIC) and BCF D(UPTAKE). Especially, the values of BCF D(TOXIC) were well consistent with those of BCF D(UPTAKE).

Wang, Xiu-Lin; Ma, Yan-Jun; Cheng, Gang; Yu, Wei-Jun; Zhang, Li-Jun

1997-09-01

138

Biofuels from algae: challenges and potential  

PubMed Central

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

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

2011-01-01

139

Hydrogen production by photosynthetic green algae.  

PubMed

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

Ghirardi, Maria L

2006-08-01

140

Engineering algae for biohydrogen and biofuel production.  

PubMed

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

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

2009-06-01

141

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

142

Fermentation metabolism and its evolution in algae  

PubMed Central

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

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

2013-01-01

143

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

144

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

145

Functional properties of carotenoids originating from algae.  

PubMed

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

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

2013-01-15

146

Mass Production of Biodiesel From Algae UROP Summer 2008 Project Proposal  

E-print Network

1 Mass Production of Biodiesel From Algae UROP Summer 2008 Project Proposal Steven A. Biorn Faculty energy products from algae. The first step in this process is to select species of algae with high growth of green algae. Once the oils have been extracted, the remnants of the algae contain protein, starches

Minnesota, University of

147

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

148

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

149

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\\u000a adequately supports the growth of both algae and zooplankton without the need to alter the medium to accommodate either the\\u000a algae or the animals. We devised a freshwater medium, named COMBO, that supports excellent growth of both algae and zooplankton.

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

1998-01-01

150

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 of the Industry and Growth · Algae's Role in WW Treatment · CO2's New Role · Research at Cal Poly · Future Work/MG 0.3 MGD average flow per facility #12;Reclaimed Algae Bacteria O2 CO2 N Organics N P CO2 P CO2 Waste

Keller, Arturo A.

151

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

152

Bromophenols from marine algae with potential anti-diabetic activities  

NASA Astrophysics Data System (ADS)

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

Lin, Xiukun; Liu, Ming

2012-12-01

153

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

154

Cobra bite wound infection caused by Shewanella algae.  

PubMed

Shewanella wound infections after snake bites are rare. We report the case of a Shewanella algae wound infection associated with a cobra bite in a 27-year-old woman. The isolate was confirmed by sequencing of the 16S ribosomal DNA gene. This case expands the reported spectrum of infection caused by S. algae and raises the possibility that S. algae could be a causative pathogen in wound infections resulting from snake bites. PMID:24602312

Liu, Po-Yu; Shi, Zhi-Yuan; Shyu, Ching-Lin; Wu, Zong-Yen; Lai, Kuo-Lung; Chang, Chih-Yen; Chen, Ying-Ju; Huang, Jin-An; Mao, Yan-Chiao; Tung, Kwong-Chung

2014-03-01

155

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

156

Method and apparatus for lysing and processing algae  

DOEpatents

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

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

2013-03-05

157

Algae Bioreactor Using Submerged Enclosures with Semi-Permeable Membranes  

NASA Technical Reports Server (NTRS)

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

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

2013-01-01

158

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.

159

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 sites in Chvaletice suggests soil toxicity of these biotopes. Keywords Soil algae, Chlorophyta

160

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

161

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

162

Pheromones in marine algae: A technical approach  

NASA Astrophysics Data System (ADS)

It is now well known that many marine organisms use low-molecular volatile substances as signals, in order to coordinate activities between different individuals. The study of such pheromones requires the isolation and enrichment of the secretions from undisturbed living cells or organisms over extended periods of time. The Grob-Hersch extraction device, which we describe here, avoids adverse factors for the biological materials such as strong water currents, rising gas bubbles or chemical solvents. Furthermore, the formation of sea-water spray is greatly reduced. The application of this technique for the isolation of pheromones of marine algae and animals is described.

Gassmann, G.; Müller, D. G.; Fritz, P.

1995-03-01

163

Bisabolanes from the red alga Laurencia scoparia.  

PubMed

Three novel halogenated beta-bisabolene sesquiterpenoids (1-3), together with two know triquinane alcohol sesquiterpenes (6 and 7), were isolated from the red alga Laurencia scoparia and their structures elucidated by spectroscopic methods. Single-crystal X-ray crystallography allowed us to confirm the structure of 1 as well as to determine the absolute configuration of all stereocenters. To the best of our knowledge, the isolation of beta-bisabolenes from the genus Laurencia has no precedent in the literature. Compound 1 showed weak in vitro anthelmintic activity against parasitant stage (L4) Nippostrongilus brasiliensis. PMID:16872159

Davyt, Danilo; Fernandez, Rafael; Suescun, Leopoldo; Mombrú, Alvaro W; Saldaña, Jenny; Domínguez, Laura; Fujii, Mutue T; Manta, Eduardo

2006-07-01

164

Biodiesel from algae: challenges and prospects.  

PubMed

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

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

2010-06-01

165

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

166

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

167

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

168

Shotgun proteomic analysis of the unicellular alga Ostreococcus tauri  

E-print Network

found to be up-regulated under low nitrogen conditions, including carbon storage pathways, glycolysis to carbon fixation and oxygen production. Among algae, pico- phytoplankton are distributed worldwideShotgun proteomic analysis of the unicellular alga Ostreococcus tauri Thierry Le Bihana,, Sarah F

Millar, Andrew J.

169

Video micrography of algae photomovement and vectorial method of biomonitoring  

NASA Astrophysics Data System (ADS)

The simultaneous recording of several photomovement parameters of algae as test-functions during biomonitoring is proposed. Green alga Dunaliella viridis Teod. was used as the test- object for the estimation of different heavy metals. The quantitative changes of photomovement parameters as a criterion of toxicity were determined by means of the vectorial method of biomonitoring.

Posudin, Yuri I.; Massjuk, N. P.; Lilitskaya, G. G.

1996-01-01

170

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

171

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

172

Energy from algae using microbial fuel cells.  

PubMed

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

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

2009-08-15

173

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

174

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

PubMed

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

Carrillo Domínguez, Silvia; Casas Valdez, Margarita; Ramos Ramos, Felipe; Pérez-Gil, Fernando; Sánchez Rodríguez, Ignacio

2002-12-01

175

Cryoalgotox: Use of cryopreserved alga in a semistatic microplate test  

SciTech Connect

Use of cryopreserved alga Selenastrum capricornutum has been evaluated as a simple and cost-efficient procedure in a new semistatic algal ecotoxicity test. Experiments have been conducted to compare performance criteria of this method, named Cryoalgotox, versus the classic microplate test using fresh algae. Cryoalgotox 72-h 50% effective concentrations (EC50s) determined with Cd{sup 2+}, Cu{sup 2+}, Cr{sup 6+}, and atrazine were more sensitive, repeatable (low coefficients of variation), and reproducible (low time effect) than the results obtained with the classical microplate tests. The effect of storage time at {minus}80 C on the sensitivity of the algae was assessed using cadmium as a toxic reference; it was shown that algae stored at {minus}80 C over a 3-month period gave comparable toxicity results to those found with fresh algae.

Benhra, A.; Radetski, C.M.; Ferard, J.F. [Univ. de Metz (France). Centre des Sciences de l`Environnement

1997-03-01

176

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

177

Biomass of algae growth on natural water medium.  

PubMed

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

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

2015-01-01

178

Isoprenoid biosynthesis in eukaryotic phototrophs: A spotlight on algae  

SciTech Connect

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

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

2012-04-01

179

Chlorophyll breakdown in higher plants and algae.  

PubMed

Leaf senescence is accompanied by the metabolism of chlorophyll (Chl) to nonfluorescent catabolites (NCCs). The pathway of Chl degradation comprises several reactions and includes the occurrence of intermediary catabolites. After removal of phytol and the central Mg atom from Chl by chlorophyllase and Mg dechelatase, respectively, the porphyrin macrocycle of pheophorbide (Pheide) a is cleaved. This two-step reaction is catalyzed by Pheide a oxygenase and RCC reductase and yields a primary fluorescent catabolite (pFCC). After hydroxylation and additional species-specific modifications, FCCs are tautomerized nonenzymically to NCCs inside the vacuole. Different subcellular compartments participate in Chl catabolism and, thus, transport processes across membranes are required. This review focuses on the catabolites and the individual reactions of Chl breakdown in higher plants. In addition, the pathway is compared to Chl conversion to red catabolites in an alga, Chlorella protothecoides. Finally, the significance and regulation of Chl degradation are discussed. PMID:11212360

Hörtensteiner, S

1999-10-15

180

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

181

Interactions of metals and protons with algae  

SciTech Connect

Proton uptake by intact algal cells was found to consist of two processes: (1) a fast (<4 s) surface reaction and (2) a slow (2h) diffusion of protons into cells. A pH titration technique measured only the rapid surface reaction that forms negative sites at higher pH. Adsorption of alkali, alkaline earth, and transition metal ions on algae was quantitatively represented by the Langmuir adsorption isotherm with its two parameters y/sub m/, the maximum amount of metal adsorbed, and K, the equilibrium constant taken as a measure of bond strength. Variations of these parameters with pH and type of metal indicate that metals adsorb to algal surfaces by electrostatic attraction to negative sites, such as carboxylate anions of poly(galaturonic acid) (pectin), as previously suggested.

Crist, R.H.; Oberholser, K.; Schwartz, D.; Marzoff, J.; Ryder, D.; Crist, D.R.

1988-07-01

182

Effective viscosity of actively swimming algae suspensions  

NASA Astrophysics Data System (ADS)

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

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

2010-11-01

183

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

184

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 transportation fuel. Algae can be cultivated on low productivity lands using low quality water. Interest in algae

Edwards, Paul N.

185

LIFETIME OF THE EXCITED STATE IN VIVO I. CHLOROPHYLL a IN ALGAE, AT ROOM  

E-print Network

LIFETIME OF THE EXCITED STATE IN VIVO I. CHLOROPHYLL a IN ALGAE, AT ROOM AND AT LIQUID NITROGEN decay of chloro- phyll (Chl) a in the green alga Chlorella pyrenoidosa, the red alga Porphyridium cruentum, and the blue-green alga Anacystis nidulans was measured by the phase- shift method under

Govindjee

186

SEN 02 Portable Algae Flow Cytometer SEN 02.1 Overview  

E-print Network

SEN 02 Portable Algae Flow Cytometer SEN 02.1 Overview The portable algae flow cytometer is a project that aims to expedite research in algae biology using microfluid-based and state is to develop a portable flow cytometer that is suitable for on-field monitoring of algae population and reduce

California at Los Angeles, University of

187

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

188

MID-LATE DEVONIAN CALCIFIED MARINE ALGAE AND CYANOBACTERIA, SOUTH CHINA  

E-print Network

MID-LATE DEVONIAN CALCIFIED MARINE ALGAE AND CYANOBACTERIA, SOUTH CHINA QI FENG,1 YI-MING GONG,1 contain microfossils generally regarded as calcified algae and cyanobacteria. These are present in 61 out with differing degrees of confidence, and placed in algae, cyanobacteria or microproblematica. Algae: Halysis

Riding, Robert

189

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.

190

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

191

Photobiological hydrogen production with switchable photosystem-II designer algae  

DOEpatents

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

Lee, James Weifu

2014-02-18

192

Potential carbon dioxide fixation by industrially important microalgae  

Microsoft Academic Search

The present study aimed at investigating the carbon metabolism in terms of carbon dioxide fixation and its destination in microalgae cultivations. To this purpose, analysis of growth parameters, media of cultivation, biomass composition and productivity and nutrients balance were performed. Four microalgae suitable for mass cultivation were evaluated: Dunaliella tertiolecta SAD-13.86, Chlorella vulgaris LEB-104, Spirulina platensis LEB-52 and Botryococcus braunii

Eduardo Bittencourt Sydney; Wilerson Sturm; Julio Cesar de Carvalho; Vanete Thomaz-Soccol; Christian Larroche; Ashok Pandey; Carlos Ricardo Soccol

2010-01-01

193

New loliolide derivatives from the brown alga Undaria pinnatifida.  

PubMed

Seven carotenoid metabolites including five loliolide derivatives have been isolated from the brown alga Undaria pinnatifida, including three new compounds. Structures of these compounds were confirmed by spectroscopic analyses and literature data. PMID:11809066

Kimura, Junji; Maki, Noritsugu

2002-01-01

194

21 CFR 73.275 - Dried algae meal.  

Code of Federal Regulations, 2010 CFR

...genus Spongiococcum, separated from its culture broth), molasses, cornsteep liquor, and a maximum of 0.3 percent ethoxyquin. The algae cells are produced by suitable fermentation, under controlled conditions, from a pure culture of...

2010-04-01

195

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...

196

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

197

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 ...

198

Harmful algae blooms removal from fresh water with modified vermiculite.  

PubMed

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

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

2014-01-01

199

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

200

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

201

A golden opportunity: Researchers making progress in understanding toxic algae  

E-print Network

from leaking septic systems. Roelke said sampling in open waters of Lake Granbury revealed a weak correlation between golden algae, bacteria, and dissolved organic matter. ?However, we have not ruled out yet that leaky septic systems might play a...

Wythe, Kathy

2008-01-01

202

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 ...

203

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

204

Algae-Bacteria Interaction in a Light-Dark Cycle  

Microsoft Academic Search

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 community of bacteria. The bacteria community enhanced the regeneration of nutrients. Of special note, is the observed generation of soluble nitrogen in the synthetic growth

Paul W. Rodgers; Joseph V. DePinto

1981-01-01

205

Green algae to land plants: An evolutionary transition  

Microsoft Academic Search

Studies focused upon the evolutionary transition from ancestral green algae to the earliest land plants are important from\\u000a a range of ecological, molecular and evolutionary perspectives. A substantial suite of ultrastructural, biochemical and molecular\\u000a data supports the concept that land plants (embryophytes) are monophyletically derived from an ancestral charophycean alga.\\u000a However, the details of phylogenetic branching patterns linking extant charophytes

Linda E. Graham

1996-01-01

206

Algae That Cause Red Tide Found Off Maine Coast  

NSDL National Science Digital Library

This Bangor Daily News article provides general information about red tide in Maine and efforts being done to track the harmful algal bloom (HAB) events. There are four major red tide causing algae in Maine: Alexandrium, Dinophysis, Prorocentrum and Pseudonitzschia. These algae can cause serious health problems in humans and other marine animals. The &amp;quot;first alert system&amp;quot; now in place now monitors for sunlight and nutrient concentrations that may lead to red tide events.

Edgecomb, Misty; News, Bangor D.

207

Modelling the effect of fluctuating herbicide concentrations on algae growth.  

PubMed

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

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

2015-03-01

208

Study on algae removal by immobilized biosystem on sponge  

NASA Astrophysics Data System (ADS)

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

Pei, Haiyan; Hu, Wenrong

2006-10-01

209

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

210

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

211

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

E-print Network

KARLODINIUM VENEFICUM AND PROROCENTRUM MINIMUM ON EARLY LIFE STAGES OF THE OYSTERS CRASSOSTREA VIRGINICA (HABs). The effects of two common Chesapeake Bay HAB dinoflagellates, Karlodinium veneficum difficult. KEY WORDS: oysters, larvae, harmful algae, HABs, Chesapeake Bay, oyster restoration, Karlodinium

North, Elizabeth W.

212

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

213

News about cryptochrome photoreceptors in algae  

PubMed Central

Cryptochromes (CRYs) are flavoproteins that are known as blue light photoreceptors in many organisms. Recently, genome sequences from a variety of algae became available. Functional characterizations of animal-like CRYs from Oestreococcus tauri, Chlamydomonas reinhardtii and Phaeodactylum tricornutum highlighted novel functions and properties. As arising from studies in fungi, certain algal CRYs of the “cryptochrome photolyase family” (PtCPF1, OtCPF1) have dual or even triple functions. They are involved in blue light perception and/or in the circadian clock and are able to repair DNA damages. On the other hand, the animal-like aCRY from C. reinhardtii is not only acting as sensory blue light- but also as sensory red light receptor thus expanding our current view of flavoproteins in general and CRYs in particular. The observed broad spectral response points to the neutral radical state of flavin, which is assumed to be the dark form in aCRY in contrast to the plant CRYs. PMID:23154511

Beel, Benedikt; Müller, Nico; Kottke, Tilman; Mittag, Maria

2013-01-01

214

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

215

Drifting algae and zoobenthos — Effects on settling and community structure  

NASA Astrophysics Data System (ADS)

Shallow (5 to 10 m) sandy bottoms in the Baltic Sea are important areas for zoobenthic production. The infaunal communities are generally governed by the hydrographical conditions are transport of the sediment through wind effects. With increasing eutrophication in the Baltic Sea, drifting mats of annual algae ( Cladophora, Stictyosiphon, Polysiphonia, Rhodemela, Sphacelaria, Pilayella, Furcellaria, Ceramium, etc) have become increasingly common, adding to the structuring and regulating factors for the infauna. In 1990 and 91, a field-study (SCUBA diving; zoobenthos and algae sampling) was carried out in the Åland archipelogo, in thennorthern and their structuring effect on the zoobenthos. Algal biomass increased from 150 ± 19 g DW·m -2 in 1990 to 832±60 g DW·m -2 in 1991, having no effect on oxygen saturation in 1990, but showing signs of reduced oxygen saturation in 1991. Organic content of the sediment remained stable (0.60 to 0.74%) during the entire study period. The zoobenthic community showed significant responses to the drifting algae at population level and in terms of community structure (by 1991: significantly reduced species number; low similarity values (40 to 65%) between bare sand and under the algae). The main species affected were the dominating bivalve Macoma balthica, the polychaetes Pygospio elegans and Manayunkia aestuarina, and the amphipod Corophium volutator. The settlement of M. balthica spat was significantly reduced by the algae (>70% in 1990/91), and no individuals of the dominating polychaetes were recorded under the mat. C. volutator, however, benefited from the algae, and greatly increased in numbers. The results clearly demonstrate the types of physical effects drift-algae will have no sandy-bottom benthos, and show that significant changes in the communities over large areas can be expected with increasing eutrophication.

Bonsdorff, Erik

216

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

217

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

218

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, Sinéad

2014-01-01

219

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

220

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

221

Visualization of oxygen distribution patterns caused by coral and algae  

PubMed Central

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

Smith, Jennifer E.; Abieri, Maria L.; Hatay, Mark; Rohwer, Forest

2013-01-01

222

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

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

2011-01-01

223

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

224

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

225

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

226

A look at diacylglycerol acyltransferases (DGATs) in algae.  

PubMed

Triacylglycerols (TAGs) from algae are considered to be a potentially viable source of biodiesel and thereby renewable energy, but at the moment very little is known about the biosynthetic pathway in these organisms. Here we compare what is currently known in eukaryotic algal species, in particular the characteristics of algal diacylglycerol acyltransferase (DGAT), the last enzyme of de novo TAG biosynthesis. Several studies in plants and mammals have shown that there are two DGAT isoforms, DGAT1 and DGAT2, which catalyse the same reaction but have no clear sequence similarities. Instead, they have differences in functionality and spatial and temporal expression patterns. Bioinformatic searches of sequenced algal genomes reveal that most algae have multiple copies of putative DGAT2s, whereas other eukaryotes have single genes. Investigating whether these putative isoforms are indeed functional and whether they confer significantly different phenotypes to algal cells will be vital for future efforts to genetically modify algae for biofuel production. PMID:22750092

Chen, Jit Ern; Smith, Alison G

2012-11-30

227

Cycloartane triterpenes from marine green alga Cladophora fascicularis  

NASA Astrophysics Data System (ADS)

Six cycloartanes were isolated from ethanol extract of marine green alga Cladophora fascicularis by column chromatography. Procedure of isolation and description of these compounds are given in this paper. The structures were elucidated as (1). 24-hydroperoxycycloart-25- en-3?-ol; (2). cycloart-25-en-3? 24-diol; (3). 25-hydroperoxycycloart-23-en-3?-ol; (4). cycloart-23-en-3?, 25-diol; (5). cycloart-23, 25-dien-3?-ol; and (6). cycloart-24-en-3?-ol by spectroscopic (MS, ID and 2D NMR) data analysis. Cycloartane derivatives are widely distributed in terrestrial plants, but only few were obtained in the alga. All these compounds that have been isolated from terrestrial plants, were found in the marine alga for the first time.

Huang, Xinping; Zhu, Xiaobin; Deng, Liping; Deng, Zhiwei; Lin, Wenhan

2006-12-01

228

Importance of algae as a potential source of biofuel.  

PubMed

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

Singh, A K; Singh, M P

2014-01-01

229

The evolution of photosynthesis in chromist algae through serial endosymbioses  

PubMed Central

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

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

2014-01-01

230

Designer proton-channel transgenic algae for photobiological hydrogen production  

DOEpatents

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

Lee, James Weifu (Knoxville, TN)

2011-04-26

231

Extremophilic micro-algae and their potential contribution in biotechnology.  

PubMed

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

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

2014-11-15

232

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

E-print Network

259 J. Phycol. 39, 259­267 (2003) MINIREVIEW THE MESOZOIC RADIATION OF EUKARYOTIC ALGAE, and heterokonts (including diatoms, brown algae, and raphidophytes). In Paleozoic and earlier eras, the fossil

Falkowski, Paul G.

233

Application of Hedonic Price Modeling to Estimate the Value of Algae Meal  

E-print Network

as Post Extracted Algae Residue (PEAR) are decomposed into their chemical constituents in order to calculate the market value of each characteristic. Calculated prices of these characteristics are then used to estimate the price of algae meal and compare...

Gogichaishvili, Ilia

2012-10-19

234

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

E-print Network

Optical microplates for high-throughput screening of photosynthesis in lipid- producing algae to the physiological level, including photosynthesis, heat shock, neurobiology, sensory networks (vision, olfaction the study of photosynthesis in algae. Societal challenges in energy sustainability have renewed interest

Basu, Amar S.

235

Oleosin of subcellular lipid droplets evolved in green algae.  

PubMed

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

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

2013-04-01

236

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

237

ALGAE DETECTION AND SHIP'S BALLAST WATER ANALYSIS BY A MICROFLUIDIC LAB-ON-CHIP DEVICE  

Microsoft Academic Search

This paper reports a microfluidic lab-on-a-chip device that can detect algae and analyze ship's ballast water treatment performance according to the standard set by the International Convention for the Control and Management of Ships’ Ballast Water and Sediments. A microfluidic differential Resistive Pulse Sensor (RPS) was employed to detect, count and size two algae of different sizes, a larger alga,

Yongxin Song; Jizhe Wang; Jiandong Yang; Yanbin Wu; Nan Li; Ning Gong; Xinxiang Pan; Yeqing Sun; Dongqing Li

2012-01-01

238

Ghana: Western Ghana's Fisherfolk Starve Amid Algae Infestation BY JESSICA MCDIARMID, 18 APRIL 2012  

E-print Network

Ghana: Western Ghana's Fisherfolk Starve Amid Algae Infestation BY JESSICA MCDIARMID, 18 APRIL 2012 not to continue fishing." Sargassum is the algae after which the Sargasso Sea - an elongated region in the middle down while tonnes of the algae were removed. In some areas people were warned not to swim due

Belogay, Eugene A.

239

Early Cretaceous benthic associations (foraminifera and calcareous algae) of a shallow tropical-water platform  

E-print Network

Early Cretaceous benthic associations (foraminifera and calcareous algae) of a shallow tropical of benthic foraminifera and calcareous algae in order to establish a precise, combined benthic biozonation species of calcareous algae, distributed among 11 genera, were recovered from the Lower Cretaceous shallow

Husinec, Antun

240

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

E-print Network

1128 volume 27 number 12 december 2009 nature biotechnology square meter per day of algae, such as triglycerides from algae or cellulosic biomass from higher plants, as feedstocks for biofuel production. The algal program sought to develop high-oil-content algae that grow at very fast rates. In our report

Cai, Long

241

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

242

ACARYOCHLORIS EXPLAINING THE RIDDLE OF CHLOROPHYLL D IN RED ALGAE AND EXPANDING PAR FOR OXYGENIC PHOTOSYNTHESIS  

E-print Network

ACARYOCHLORIS ­ EXPLAINING THE RIDDLE OF CHLOROPHYLL D IN RED ALGAE AND EXPANDING PAR FOR OXYGENIC strain is shown to live epi- phytically on the red alga Gelidium caulacantheum, which itself is harvested by the red alga. Availability of far red light, however, is relatively unaffected by DOM or red

Oregon, University of

243

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 December 2008 Received in revised form 15 May 2009 Accepted 23 May 2009 Keywords: Floating Algae Index (FAI Remote sensing Ocean color Climate data record Various types of oating algae have been reported in open

Meyers, Steven D.

244

A Framework to Report the Production of Renewable Diesel from Algae  

E-print Network

A Framework to Report the Production of Renewable Diesel from Algae Colin M. Beal & Colin H. Smith(s) 2010. This article is published with open access at Springerlink.com Abstract Recently, algae have algae are a viable source for renewable diesel, three questions that must be answered are (1) how much

245

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 nanoparticle (nCeO2) suspensions, towards freshwater micro-algae assessing the effect nCeO2 suspensions microscopy (TEM). In addition, the interaction between NPs and algae were investigated using flow

Boyer, Edmond

246

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

E-print Network

Are Algae Relevant to the Detritus-Based Food Web in Tank-Bromeliads? Olivier Brouard1 , Anne, Universite´ Paul Sabatier, UMR CNRS 5245, Toulouse, France Abstract We assessed the occurrence of algae and with regard to the structure of other aquatic microbial communities held in the tanks. Algae were retrieved

Boyer, Edmond

247

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

248

FL47CH15-Goldstein ARI 25 November 2014 9:45 Green Algae as Model  

E-print Network

FL47CH15-Goldstein ARI 25 November 2014 9:45 Green Algae as Model Organisms for Biological Fluid green algae, spanning from the unicellular Chlamydomonas to multicellular Volvox, have emerged as model of flagellar synchronization. Green algae are well suited to the study of such problems because of their range

Goldstein, Raymond E.

249

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

E-print Network

Climate implications of algae-based bioenergy systems Andres Clarens, PhD Assistant Professor Civil of algae and other nonconventional feedstocks, are being developed. This talk will explore several systems priorities. This is an especially challenging problem for algae-based biofuels because production pathways

Walter, M.Todd

250

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

251

Optimal engineered algae composition for the integrated simultaneous production of bioethanol  

E-print Network

1 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 technologies for the biodiesel synthesis from algae oil, enzymatic or homogeneous alkali catalyzed, the most

Grossmann, Ignacio E.

252

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

253

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.

254

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

255

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

256

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.

257

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

258

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 independently evolved hundreds of times among the floridiophyte red algae. Much is known about the life history class of red algae, Plocamiocolax puvinata, has lost the atp8 gene entirely, indicating that this gene

Lane, Chris

259

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

260

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 while acquiring Raman signals from the algae. The time dependence of fluorescence background is char

261

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

262

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

263

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

264

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

265

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

266

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

267

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

268

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.

269

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

270

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...

271

Evidence that an Amoeba Acquired a Chloroplast by Retaining Part of an Engulfed Eukaryotic Alga  

Microsoft Academic Search

Chlorarachniophytes are amoeboid algae with unusual chloroplasts. Instead of the usual two membranes that surround the chloroplasts of plants, green algae, and red algae, the chloroplasts of chlorarachniophytes have four bounding membranes. The extra membranes may reflect an unusual origin of chlorarachniophyte chloroplasts. Rather than inheriting the organelle directly from their ancestors, chlorarachniophytes may have adopted the chloroplast of an

Geoffrey I. McFadden; Paul R. Gilson; Claudia J. B. Hofmann; Gregory J. Adcock; Uwe-G. Maier

1994-01-01

272

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; Jonáš, Alexandr; Pilát, Zden?k; Zemánek, Pavel; Nedbal, Ladislav; T?íska, Jan; Kotas, Petr; Trtílek, Martin

2010-01-01

273

Raman microspectroscopy of individual algal cells: sensing unsaturation of storage lipids in vivo.  

PubMed

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) (CH(2) 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; Jonáš, Alexandr; Pilát, Zden?k; Zemánek, Pavel; Nedbal, Ladislav; T?íska, Jan; Kotas, Petr; Trtílek, Martin

2010-01-01

274

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

275

Biodegradation of phenols by the alga Ochromonas danica.  

PubMed Central

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

Semple, K T; Cain, R B

1996-01-01

276

Toxins of a Blue-Green Alga: Similarity to Saxitoxin  

Microsoft Academic Search

Toxins were isolated from the freshwater blue-green alga Aphanizomenon flos-aquae. The toxic fractions were characterized by paper and thin-layer chromatography, isolation characteristics, infrared spectra, physiological activity, and reactivity with specific color reagents. The toxic fractions appear to be similar, if not identical, to saxitoxin (paralytic shellfish toxin), which is produced by the marine dinoflagellate Gonyaulax catenella.

Eugene Jackim; John Gentile

1968-01-01

277

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

278

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

279

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

280

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

281

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 ...

282

BIOCONCENTRATION OF A HEXACHLOROBIPHENYL IN GREAT LAKES PLANKTONIC ALGAE  

EPA Science Inventory

The bioconcentration of 2,4,5,2',4',5'-hexachlorobiphenyl (HCB) was examined in the Great Lakes algae Fragilaria crotonensis, Ankistrodesmus falcatus, and Microcystis sp. The bioconcentration factors varied from species to species, whether they were expressed in terms of cell num...

283

BACTERIA, FUNGI, AND UNICELLULAR ALGAE Blank page retained for pagination  

E-print Network

CHAPTER VI BACTERIA, FUNGI, AND UNICELLULAR ALGAE #12;Blank page retained for pagination #12;MARINE BACTERIA AND FUNGI IN THE GULF OF MEXICO I By CLAUDE E. ZOBELL, Scripps lrutitution of Oceano; Bavendamm 1932), there are very few published reports on bacteria and fungi in the nearby Gulf of Mexico

284

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

285

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

286

Effect of oxygen removal on hydrogen photoproduction in algae  

SciTech Connect

Hydrogen photoproduction from water in Scenedesmus cells requires removal of oxygen by a reagent in contact with the algae. Both deoxyhemoglobin and deoxymyoglobin stimulated hydrogen production by reversible absorption of oxygen. Their effectiveness was greatly increased when other oxygen-combining reagents were present in a separate chamber with deoxyhemoglobin and deoxymyoglobin serving as reversible oxygen transfer agents. 20 references

Rosenkrans, A.M.; Rosen, M.M.; Krasna, A.I.

1983-07-01

287

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

288

Biodiesel Fuel Production from Algae as Renewable Energy  

Microsoft Academic Search

Biodiesel is biodegradable, less CO2 and NOx emissions. Continuous use of petroleum sourced fuels is now widely recognized as unsustainable because of depleting supplies and the contribution of these fuels to the accumulation of carbon dioxide in the environment. Renewable, carbon neutral, transport fuels are necessary for environmental and economic sustainability. Algae have emerged as one of the most promising

Sharif Hossain; Aishah Salleh

289

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

290

Recovery of dairy manure nutrients by benthic freshwater algae  

Microsoft Academic Search

Harnessing solar energy to grow algal biomass on wastewater nutrients could provide a holistic solution to nutrient management problems on dairy farms. The production of algae from a portion of manure nutrients to replace high-protein feed supplements which are often imported (along with considerable nutrients) onto the farm could potentially link consumption and supply of on-farm nutrients. The objective of

Ann C. Wilkie; Walter W. Mulbry

2002-01-01

291

ASPECTS OF PHOSPHATE UTILIZATION BY BLUE-GREEN ALGAE  

EPA Science Inventory

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

292

A simple classification of the volvocine algae by formal languages.  

PubMed

There are several explanations of why certain primitive multicellular organisms aggregate in particular forms and why their constituent cells cooperate with one another to a particular degree. Utilizing the framework of formal language theory, we have derived one possible simple classification of the volvocine algae-one of the primitive multicells-for some forms of aggregation and some degrees of cooperation among cells. The volvocine algae range from the unicellular Chlamydomonas to the multicellular Volvox globator, which has thousands of cells. The classification we use in this paper is based on the complexity of Parikh sets of families on Chomsky hierarchy in formal language theory. We show that an alga with almost no space closed to the environment, e.g., Gonium pectorale, can be characterized by PsFIN, one with a closed space and no cooperation, e.g., Eudorina elegans, by PsCF, and one with a closed space and cooperation, e.g., Volvox globator, by PslambdauSC. This classification should provide new insights into the necessity for specific forms and degrees of cooperation in the volvocine algae. PMID:16005503

Yoshida, Hiroshi; Yokomori, Takashi; Suyama, Akira

2005-11-01

293

TOXICITY AND UPTAKE OF KEPONE IN MARINE UNICELLULAR ALGAE  

EPA Science Inventory

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

294

THE OCCURRENCE OF HORMESIS IN PLANTS AND ALGAE  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

295

DNA is present in the pyrenoid core of the siphonous green algae of the genus Caulerpa and yellow-green algae of the genus Pseudodichotomosiphon  

Microsoft Academic Search

Summary The pyrenoids of a number of siphonous green and yellow-green algae have been examined for the presence of chloroplast DNA (chloroplast nucleoids). We have found a conspicuous localization of chloroplast DNA in the pyrenoid core ofCaulerpa lentillifera andC. fergusonii (siphonous green algae), andPseudodichotomosiphon constrictus (a siphonous yellow-green alga) using fluorescence microscopy after staining with the DNA specific fluorochrome 4',6-diamidino-2-phenylindole

S. Miyamura; T. Hori

1991-01-01

296

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

PubMed

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

Melis, Anastasios

2007-10-01

297

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

298

Project EARTH-11-RR2: Co-evolution of iodine antioxidant mechanism in marine algae and Earth-surface  

E-print Network

Project EARTH-11-RR2: Co-evolution of iodine antioxidant mechanism in marine algae and Earth algae (yet they are lacking in green algae) ­ but the phylogenetic distribution of iodine accumulation haloperoxidases. The first appearance and important divergence of brown algae occurred within the last 200 myr

Henderson, Gideon

299

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

300

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

301

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

302

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

303

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

304

Lophocladines, Bioactive Alkaloids from the Red Alga Lophocladia sp.  

PubMed Central

Lophocladines A (1) and B (2), two 2,7-naphthyridine alkaloids, were isolated from the marine red alga Lophocladia sp. collected in the Fijian Islands. Their structures were deduced on the basis of high-resolution mass spectra and one- and two-dimensional NMR spectroscopy. Lophocladine A (1) displayed affinity for NMDA receptors and was found to be a ?-opioid receptor antagonist, whereas lophocladine B (2) exhibited cytotoxicity to NCI-H460 human lung tumor and MDA-MB-435 breast cancer cell lines. Immunofluorescence studies indicated that the cytotoxicity of lophocladine B (2) was correlated with microtubule inhibition. This is the first reported occurrence of alkaloids based on a 2,7-naphthyridine skeleton from red algae. PMID:16643042

Gross, Harald; Goeger, Douglas E.; Hills, Patrice; Mooberry, Susan L.; Ballantine, David L.; Murray, Thomas F.; Valeriote, Frederick A.; Gerwick, William H.

2009-01-01

305

Potential energy production from algae on marginal land in China.  

PubMed

This study is aimed to systematically estimate marginal land resources with different grades (total area; land with certain eco-environmental-economic feasibility; centralized reserve land) in China, and evaluate potential energy production from microalgae on marginal lands in the long-, mid- and near-term, based on a model. The annual potential energy production from algae in total marginal land of China (APEMC) was estimated to 4.19 billion standard coal equivalent (tce), far more than total annual energy consumption equivalent in China (TECCE) in 2007. For microalgae with 35% lipid content, the APEMC in the mid-term would be 37.6-65.8% of the TECCE in 2007. The corresponding annual CO(2) emission mitigation by replacement of fossil fuels by algal bioenergy would be 4.27-7.44 billiont. Although Southwest China provides the highest potential algae production in the long-term, Northwest China provides the highest value in the near-term. PMID:21945161

Zhang, Qingtao; Ma, Jiong; Qiu, Guoyu; Li, Li; Geng, Shu; Hasi, E; Li, Cheng; Wang, Guangyi; Li, Xiaoyan

2012-04-01

306

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

307

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

308

Green Algae as Model Organisms for Biological Fluid Dynamics  

NASA Astrophysics Data System (ADS)

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.

Goldstein, Raymond E.

2015-12-01

309

Determination of aliphatic hydrocarbons in the alga Himanthalia elongata.  

PubMed

The algae considered new foods according to Regulation CE 258/97 need a guarantee of their healthfulness before being in the European market. In this work ten samples of the brown alga Himanthalia elongata have been analyzed with the aim of verifying the absence of aliphatic hydrocarbons, due to the ability of the macroalgae to capture lipophilic organic compounds of the marine water coming from accidental or continuous leaks of raw oil and refined products, which happen each year with the growth of the industrialization and the demand of energy. The fat of the samples were Soxhlet extracted using hexane:dichloromethane (1:1) for 7h. The organic fractions were purified using silica microcolumns. The identification and quantification of the aliphatic hydrocarbons have been carried out using gas chromatography (GC) with flame ionization detector (FID). The total hydrocarbon content was between 14.8 and 40.2 microg g(-1) dry weight. PMID:14759670

Punín Crespo, M O; Lage Yusty, M A

2004-02-01

310

Application of novel extraction technologies for bioactives from marine algae.  

PubMed

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

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

2013-05-22

311

Biodegradable thermoplastic composites based on polyvinyl alcohol and algae.  

PubMed

Algae constitute a largely available, low value material from renewable resources of marine origin to be used for the production of eco-compatible composites. Fibers of the green alga Ulva armoricana from the French coast were positively evaluated for the production of composites with a hydrophilic, eco-compatible polymer, such as poly(vinyl alcohol) (PVA) as continuous matrix by casting of aqueous suspensions and compression molding. PVA, Ulva, and starch were also successfully processed by the melt in the presence of glycerol. Positive results were obtained for film-forming properties and mechanical characteristics also with limited amounts of PVA (40%) attesting for Ulva suitability to be introduced in composites (up to 30%). Degradation in soil of Ulva and an Ulva-based composites outlined a rapid mineralization of Ulva in the selected medium (over 80% in 100 days) while the composite samples underwent a mineralization rate affected by the different component propensity to degradation. PMID:18257530

Chiellini, Emo; Cinelli, Patrizia; Ilieva, Vassilka I; Martera, Martina

2008-03-01

312

INVESTIGATION OF PHOTOSYNTHETIC BACTERIA AND ALGAE BY RESONANCE RAMAN SPECTROSCOPY  

Microsoft Academic Search

Cyanobacteria and algae comprise a large and diverse group of organisms that are widely distributed in freshwater, marine, terrestrial, and extreme environments. Cyanobacterial and algal identification and classification rely on morphological characterization and 16S rRNA gene sequence analysis. Morphology however, can be misleading in certain circumstances, while 16S rRNA gene sequencing can be time consuming. Analysis of pigments that have

Craig P. MARSHALL; Stefan LEUKO

313

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

314

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

315

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

316

Algal omics: unlocking bioproduct diversity in algae cell factories.  

PubMed

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

Guarnieri, Michael T; Pienkos, Philip T

2015-03-01

317

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

318

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, Jürgen H.; Falk, Heinz

2010-01-01

319

Chloroplast genome characterization in the red alga Griffithsia pacifica.  

PubMed

It has been suggested that cyanobacteria served as the ancestors for rhodophytic algae whose chloroplasts contain chlorophyll a and phycobilins, and that a rodophyte served as the plastid source for chromophytic plants that contain chlorophylls a and c. Although organellar DNA has been used to assess phylogenetic relatedness among terrestrial plants and green algae whose chloroplasts contain chlorophylls a and b, few data are presently available on the molecular profile of plastid DNA in chromophytes or rhodophytes. In this study the chloroplast genome of the rhodophytic, filamentous alga Griffithsia pacifica has been characterized. DNA was purified from isolated chloroplasts using protease k treatment and sodium dodecyl sulfate lysis followed by density centrifugation in Hoechst-33258 dye-CsCl gradients. Single and double restriction enzyme digests demonstrate that the DNA prepared from purified chloroplasts has a genome size of about 178 kilobase pairs (kb). A restriction map of this chloroplast genome demonstrates that it is circular and, unlike the chloroplast DNA (cpDNA) in most other plants, contains only a single ribosomal DNA operon. DNA was also purified from the mitochondria that co-isolated with chloroplasts. Mitochondrial DNA consists of molecules that range in size from 27 to 350 kb based on restriction endonuclease digestion and electron microscopic analysis. PMID:17191345

Li, N; Cattolico, R A

1987-09-01

320

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

321

Measurement of Carbon Dioxide Compensation Points of Freshwater Algae 1  

PubMed Central

A technique is described for the measurement of total dissolved inorganic carbon by acid release as CO2 followed by its conversion to methane and detection by flame ionization in a modified gas chromatograph. This method was used to determine the dissolved inorganic carbon concentration reached at compensation point when algae were allowed to photosynthesize in a closed system in a buffer at known pH, and the CO2 compensation point was calculated from this concentration. The CO2 compensation points of 16 freshwater algae were measured at acid and alkaline pH in air-saturated medium: at acid pH the CO2 compensation points ranged from 4.8 to 41.5 microliters per liter while at alkaline pH they ranged from 0.2 to 7.2 microliters per liter. Removal of O2 from the medium caused a slight lowering of compensation point at acid pH but had little effect at alkaline pH. These low, O2-insensitive compensation points are characteristic of C4 plants. It is suggested that these low CO2 compensation points are maintained by an active bicarbonate uptake by algae especially at alkaline pH. PMID:16661077

Birmingham, Brendan C.; Colman, Brian

1979-01-01

322

Photosynthetic circadian rhythmicity patterns of Symbiodium, the coral endosymbiotic algae  

PubMed Central

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

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

2013-01-01

323

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

324

Phycobilisome Heterogeneity in the Red Alga Porphyra umbilicalis1  

PubMed Central

Phycobilisomes were isolated from Rhodophyceae brought from the field (Porphyra umbilicalis) or grown in culture under laboratory conditions (Antithamnion glanduliferum). In P. umbilicalis two kinds of well-coupled (ellipsoidal and hemidiscoidal) phycobilisomes were detected, in contrast to A. glanduliferum cultured algae in which only one kind of well-coupled, ellipsoidaltype phycobilisome appeared. The new phycobilisome-type particle detected in P. umbilicalis is characterized by an impoverishment in R-phycoerythrin and by sedimentation at lower density. The comparison between both phycobilisomes of P. umbilicalis allows determination of the presence of one colorless linker polypeptide (30 kilodaltons) associated with R-phycocyanin and allophycocyanin and two (40 and 38 kilodaltons) associated to R-phycoerythrin. The percentage of linker polypeptides associated with this pigment is low in the new phycobilisome-like particle detected. This suggests that part of the R-phycoerythrin is less strongly bound to the phycobilisome than the other pigments. This feature could probably explain the existence of two kinds of phycobilisomes as intermediary steps of phycobilisome organization in algae exposed to rapid changes in environmental factors. In contrast, algae growing in culture and adapted to specific conditions do not present intermediary organization steps. Polypeptide composition and identification are given for this phycobilisome-like particle. Images Figure 4 Figure 5 PMID:16667317

Algarra, Patricia; Thomas, Jean-Claude; Mousseau, Anne

1990-01-01

325

Measurement of rates of grazing of the ostracod Cyprinotus carolinensis on blue-green algae  

Microsoft Academic Search

Measurements were made of the rates of grazing of the ostracod Cyprinotus carolinensis fed 14C-labelled filamentous blue-green algae (cyanobacteria). The grazing rate was a linear function of food concentration at densities below 1.1 µg dry weight of algae · ml-1 and independent of concentration at densities above 11.5 µg algae · ml-1. Starvation affected grazing rates significantly, but light vs.

I. F. Grant; E. A. Egan; M. Alexander

1983-01-01

326

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

327

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

328

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...

329

Biosorption of heavy metal ions to brown algae, Macrocystis pyrifera, Kjellmaniella crassiforia, and Undaria pinnatifida  

SciTech Connect

A fundamental study of the application of brown algae to the aqueous-phase separation of toxic heavy metals was carried out. The biosorption characteristics of cadmium and lead ions were determined with brown algae, Macrocystis pyrifera, Kjellmaniella crassiforia, and Undaria pinnatifida. A metal binding model proposed by the authors was used for the description of metal binding data. The results showed that the biosorption of bivalent metal ions to brown algae was due to bivalent binding to carboxylic groups on alginic acid in brown algae.

Seki, Hideshi; Suzuki, Akira [Hokkaido Univ., Hakodate (Japan)] [Hokkaido Univ., Hakodate (Japan)

1998-10-01

330

Symbiotic Associations in the Phenotypically-Diverse Brown Alga Saccharina japonica  

E-print Network

of marine bacterial isolates on the growth and morphology of82]). Bacterial symbionts (especially with growth promotinggrowth promoting agents to improve alga productivity. Proteobacteria Community Composition Bacterial

Balakirev, Evgeniy S.; Krupnova, Tatiana N.; Ayala, Francisco J.

2012-01-01

331

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

PubMed Central

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

2013-01-01

332

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

333

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

334

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

335

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

336

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

337

Endosymbiotic alga from green hydra under the influence of cinoxacin.  

PubMed

Cinoxacin (Cxn) showed a strong effect on the endosymbiotic alga Chlorella; it was significantly damaged. Changes in algal color, position, structure and ultrastructure were found. In some algal cells ultrastructures were completely destroyed. The antichloroplastal and antimitochondrial effect was especially expressed. Damage to the thylakoid system of chloroplasts was more pronounced with increasing Cxn concentration. Some of the mitochondria were swollen and some of them were completely destroyed. From the evolutionary point of view, the correlation between antibacterial, and antichloroplastal and antimitochondrial effect of Cxn points to the evolutionary connection of chloroplasts and mitochondria with eubacteria. PMID:16295658

Kovacevi?, G; Kalafati?, M; Ljubesi?, N

2005-01-01

338

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

339

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

340

As corn-based biofuels reach their practical limits, advanced algae-based biofuels are poised to supply  

E-print Network

SEMTE abstract As corn-based biofuels reach their practical limits, advanced algae-based biofuels will be discussed as an economical carbon source for the algae. A highly scalable materials production technique

Reisslein, Martin

341

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...

342

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.

343

Microbial to reef scale interactions between the reef-building coral Montastraea annularis and benthic algae  

PubMed Central

Competition between reef-building corals and benthic algae is of key importance for reef dynamics. These interactions occur on many spatial scales, ranging from chemical to regional. Using microprobes, 16S rDNA pyrosequencing and underwater surveys, we examined the interactions between the reef-building coral Montastraea annularis and four types of benthic algae. The macroalgae Dictyota bartayresiana and Halimeda opuntia, as well as a mixed consortium of turf algae, caused hypoxia on the adjacent coral tissue. Turf algae were also associated with major shifts in the bacterial communities at the interaction zones, including more pathogens and virulence genes. In contrast to turf algae, interactions with crustose coralline algae (CCA) and M. annularis did not appear to be antagonistic at any scale. These zones were not hypoxic, the microbes were not pathogen-like and the abundance of coral–CCA interactions was positively correlated with per cent coral cover. We propose a model in which fleshy algae (i.e. some species of turf and fleshy macroalgae) alter benthic competition dynamics by stimulating bacterial respiration and promoting invasion of virulent bacteria on corals. This gives fleshy algae a competitive advantage over corals when human activities, such as overfishing and eutrophication, remove controls on algal abundance. Together, these results demonstrate the intricate connections and mechanisms that structure coral reefs. PMID:22090385

Barott, Katie L.; Rodriguez-Mueller, Beltran; Youle, Merry; Marhaver, Kristen L.; Vermeij, Mark J. A.; Smith, Jennifer E.; Rohwer, Forest L.

2012-01-01

344

Photoperiodic long-day control of sporophyll and hair formation in the brown alga Undaria pinnatifida  

Microsoft Academic Search

Two photoperiodic responses, the development of sporophylls and hairs, havebeen quantified in sporophytes of the brown alga Undaria pinnatifida. In a finalexperiment, the algae were cultivated in outdoor, 2000-L seawater tanks in agreenhouse for up to 12 weeks, and daylength was regulated by automatic blindsmounted on top of the tanks. Vegetative young sporophytes were treated undershort-day (SD; 8 h light

Shaojun Pang; Klaus Lüning

2004-01-01

345

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

346

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

347

Oxidative stress tolerance in the filamentous green algae Cladophora glomerata and Enteromorpha ahlneriana  

Microsoft Academic Search

Cladophora glomerata (L.) Kütz. and Enteromorpha ahlneriana Bliding are morphologically similar filamentous green algae that are dominants in the upper littoral zone of the brackish Baltic Sea. As these two species co-exist in a continuously fluctuating environment, we hypothesised that they may have different strategies to cope with oxidative stress. This was tested in laboratory experiments through stressing the algae

Kyung-sil Choo; Pauli Snoeijs; Marianne Pedersén

2004-01-01

348

The distribution and abundance of algae in saline lakes of Saskatchewan, Canada  

Microsoft Academic Search

Collections of algae, mainly planktonic, were made from 41 saline lakes in southern Saskatchewan ranging in salinity from 3.2 to 428 g l-1. Algae in 7 phyla, 8 classes, 42 families, 91 genera and 212 species and varieties were identified. Fourteen species were restricted to hypersaline (50 g l-1) waters and eleven of these were diatoms. In general, species diversity

U. T-heodore Hammer; Jennifer Shamessl; Robert C. Haynes

1983-01-01

349

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 algae life cycle studies and compare new analyses of multiple production scenarios and process the life cycle greenhouse gas emissions, net energy consumption, and net liquid fuels production

350

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...

351

The current potential of algae biofuels in the United Arab Emirates  

Technology Transfer Automated Retrieval System (TEKTRAN)

In spite of future uncertainties about industrial algae biofuel production, the UAE is planning to become "a world leader in biofuels from the algae industry by 2020;" thus joining major countries which have already started producing renewable energy and biofuels (biodiesel and bioethanol) from rene...

352

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

E-print Network

#12;1 Facts about Cyanobacteria (Blue-green Algae) and Cyanobacterial Harmful Algal Blooms (CyanoHABs) Cyanobacteria (blue-green algae) Cyanobacteria are bacteria that grow in water and are photosynthetic (use sunlight to create food and support life). Cyanobacteria live

353

FRESHWATER ALGAE OF RAE LAKES BASIN, KINGS CANYON NATIONAL PARK (CALIFORNIA)  

EPA Science Inventory

This report illustrates and characterizes algae (exclusive of diatoms) found in Kings Canyon National Park, California and describes their distribution among the Rae Lakes within. It is the first taxonomic study of the freshwater algae for the southern Sierra Nevada and the most ...

354

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

355

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

356

Grazing catfish, fishing birds, and attached algae in a Panamanian stream  

Microsoft Academic Search

In streams where algivorous fishes abound, striking variation of attached algae often develops along depth gradients, with bands of high standing crops in shallow water (20 cm) water, algae were rapidly consumed by grazing catfish. Catfish were removed from three stream pools and left in place in three control pools. Ten days after catfish removal, algal standing crops in deep

Mary E. Power; Tom L. Dudley; Scott D. Coopeti

1989-01-01

357

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

358

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

359

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

360

Identifying vital effects in Halimeda algae with Ca isotopes  

NASA Astrophysics Data System (ADS)

Geochemical records of biogenic carbonates provide some of the most valuable records of the geological past, but are often difficult to interpret without a mechanistic understanding of growth processes. In this experimental study, Halimeda algae are used as a test organism to untangle some of the specific factors that influence their skeletal composition, in particular their Ca-isotope composition. Algae were stimulated to precipitate both calcite and aragonite by growth in artificial Cretaceous seawater, resulting in experimental samples with somewhat malformed skeletons. The Ca-isotope fractionation of the algal calcite (-0.6‰) appears to be much smaller than that for the algal aragonite (-1.4‰), similar to the behaviour observed in inorganic precipitates. However, the carbonate from Halimeda has higher Ca-isotope ratios than inorganic forms by approximately 0.25‰, likely because of Rayleigh distillation within the algal intercellular space. In identifying specific vital effects and the magnitude of their influence on Ca-isotope ratios, this study suggests that mineralogy has a first-order control on the marine Ca-isotope cycle.

Blättler, C. L.; Stanley, S. M.; Henderson, G. M.; Jenkyns, H. C.

2014-12-01

361

Thiamine biosynthesis in algae is regulated by riboswitches.  

PubMed

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

2007-12-26

362

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

PubMed

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

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

2010-07-01

363

Cellular response of freshwater green algae to perfluorooctanoic acid toxicity.  

PubMed

Perfluorooctanoic acid (PFOA) is a kind of persistent organic pollutants and its aquatic eco-toxicity has attracted wide attention; however, the mechanism involved in its toxicity as well as the cell response against PFOA have not been well established. Herein, using single-celled green algae Chlorella pyrenoidosa and Selenastrum capricornutum at the logarithmic growth stage as test organisms, we studied the toxic effects of PFOA on the cell permeability, The 96 h-EC(50) values of PFOA for C. pyrenoidosa and S. capricornutum were 207.46 mg L(-1) and 190.99 mg L(-1), respectively, lower than the 96 h-EC(50) values reported in the literatures. After 96 h of PFOA exposure, the permeability of the cell membranes of both algae was significantly decreased, and the chlorophyll concentration mirrored the trends of algal growth. In both algal species, after a 192-h exposure to a low concentration of PFOA, the activities of superoxide dismutase and catalase were greater than those of the control. At higher concentrations of PFOA, activities of superoxide dismutase and catalase were strongly inhibited. These results indicate that long-term exposure to low levels of PFOA may induce excessive generation of reactive oxygen species in algal cells, causing oxidative damage to cells. PMID:23183033

Xu, Dongmei; Li, Chandan; Chen, Hong; Shao, Bo

2013-02-01

364

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

365

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; 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.

2014-01-01

366

Naphthenic acid biodegradation by the unicellular alga Dunaliella tertiolecta.  

PubMed

Naphthenic acids (NAs) are a major contributor to toxicity in tailings waste generated from bitumen production in the Athabasca Oil Sands region. While investigations have shown that bacteria can biodegrade NAs and reduce tailings toxicity, the potential of algae to biodegrade NAs and the biochemical mechanisms involved remain poorly understood. Here, we discovered that the marine alga Dunaliella tertiolecta is able to tolerate five model NAs (cyclohexanecarboxylic acid, cyclohexaneacetic acid, cyclohexanepropionic acid, cyclohexanebutyric acid and 1,2,3,4-tetrahydro-2-naphthoic acid) at 300mgL(-1), a level which exceeds that of any single or combination of NAs typically found in tailings ponds. Moreover, we show that D. tertiolecta can metabolize four of the model NAs. Analysis of NA-amended cultures of D. tertiolecta via low resolution gas chromatography-mass spectrometry allowed us to quantify decreasing NA levels, identify metabolites, and formulate putative mechanisms of biodegradation. Degradation of cyclohexanebutyric acid and cyclohexanepropionic acid proceeded via ?-oxidation and resulted in the transient accumulation of cyclohexaneacetic acid and cyclohexanecarboxylic acid, respectively. Cyclohexanecarboxylic acid was metabolized via 1-cyclohexenecarboxylic acid suggesting that further degradation may occur by step-wise ?-oxidation. When D. tertiolecta was inoculated in the presence of oil sands tailings water from the Athabasca region, biodegradation of single-ring NAs was observed relative to controls. This result corroborates the trend we observed with the single-ring model NAs. PMID:21459409

Quesnel, Dean M; Bhaskar, Iyswarya M; Gieg, Lisa M; Chua, Gordon

2011-07-01

367

Shotgun proteomic analysis of the unicellular alga Ostreococcus tauri.  

PubMed

Ostreococcus tauri is a unicellular green alga and amongst the smallest and simplest free-living eukaryotes. The O. tauri genome sequence was determined in 2006. Molecular, physiological and taxonomic data that has been generated since then highlight its potential as a simple model species for algae and plants. However, its proteome remains largely unexplored. This paper describes the global proteomic study of O. tauri, using mass spectrometry-based approaches: phosphopeptide enrichment, cellular fractionation, label-free quantification and (15)N metabolic labeling. The O. tauri proteome was analyzed under the following conditions: sampling at different times during the circadian cycle, after 24h of illumination, after 24h of darkness and under various nitrogen source supply levels. Cell cycle related proteins such as dynamin and kinesin were significantly up-regulated during the daylight-to-darkness transition. This is reflected by their higher intensity at ZT13 and this transition phase coincides with the end of mitosis. Proteins involved in several metabolic mechanisms were found to be up-regulated under low nitrogen conditions, including carbon storage pathways, glycolysis, phosphate transport, and the synthesis of inorganic polyphosphates. Ostreococcus tauri responds to low nitrogen conditions by reducing its nitrogen assimilation machinery which suggests an atypical adaptation mechanism for coping with a nutrient-limited environment. PMID:21635980

Le Bihan, Thierry; Martin, Sarah F; Chirnside, Eliane S; van Ooijen, Gerben; Barrios-Llerena, Martin E; O'Neill, John S; Shliaha, Pavel V; Kerr, Lorraine E; Millar, Andrew J

2011-09-01

368

Red coralline algae assessed as marine pH proxies using (11)B MAS NMR.  

PubMed

Reconstructing pH from biogenic carbonates using boron isotopic compositions relies on the assumption that only borate, and no boric acid, is present. Red coralline algae are frequently used in palaeoenvironmental reconstruction due to their widespread distribution and regular banding frequency. Prior to undertaking pH reconstructions using red coralline algae we tested the boron composition of the red coralline alga Lithothamnion glaciale using high field NMR. In bulk analysed samples, thirty percent of boron was present as boric acid. We suggest that prior to reconstructing pH using coralline algae 1) species-specific boron compositions and 2) within-skeleton special distributions of boron are determined for multiple species. This will enable site selective boron analyses to be conducted validating coralline algae as palaeo-pH proxies based on boron isotopic compositions. PMID:25640229

Cusack, M; Kamenos, N A; Rollion-Bard, C; Tricot, G

2015-01-01

369

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

370

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.

371

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.

372

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

373

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

374

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

375

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.

376

Effects of depth, sediment and grazers on the degradation of drifting filamentous algae ( Cladophora glomerata and Pilayella littoralis)  

Microsoft Academic Search

Eutrophication in the northern Baltic Sea promotes growth of annual filamentous algae. The algae detach, gather at the bottom and give rise to algal mats of varying size, density, composition and condition. Dense mats of filamentous algae induce anoxia, which in turn leads to faunal mortality. By a set of field experiments, we have studied the fate of the abundant

Sonja Salovius; Erik Bonsdorff

2004-01-01

377

Managing phosphorus fertilizer to reduce algae, maintain water quality, and sustain yields in water-seeded rice  

Technology Transfer Automated Retrieval System (TEKTRAN)

In water-seeded rice systems blue-green algae (cyanobacteria) hinder early-season crop growth by dislodging rice seedlings and reducing light. Since algae are often phosphorus (P) limited, we investigated whether changing the timing of P fertilizer application could reduce algae without reducing cro...

378

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

379

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

380

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 CO2 and temperature (CO2-T) scenarios have not been quantified. We exposed CCA skeletons (Porolithon onkodes) to four CO2-T treatments (pre-industrial, present-day, SRES-B1 reduced CO2 emission scenario, SRES-A1FI business-as-usual CO2 emission scenario) under natural light cycles vs. constant dark conditions for 8 weeks. Dissolution rates of skeletons without photo-endoliths were dramatically higher (200%) than those colonized by endolithic algae across all CO2-T scenarios. This suggests that daytime photosynthesis by microborers counteract dissolution by reduced saturation states resulting in lower net erosion rates over day-night cycles. Regardless of the presence or absence of phototrophic microborers, skeletal dissolution increased significantly under the spring A1FI "business-as-usual" scenario, confirming the CCA sensitivity to future oceans. Projected ocean acidity and temperature may significantly disturb the stability of reef frameworks cemented by CCA, but surficial substrates harboring photosynthetic microborers will be less impacted than those without algal endoliths.

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

2014-02-01

381

Changes of cellular superficial configuration of symbiotic algae during cultivation from two anemones found in the South China Sea  

NASA Astrophysics Data System (ADS)

Symbiotic algae from two anemones, Radianthus macrodactylus and Stichodactyla mertensii, found in the South China Sea, were cultivated in ASP-8A medium in this study. Changes of superficial configuration of symbiotic algae during the cultivation were studied by means of a microscope and a scanning electron microscope (SEM). A number of small cavities appeared on the surfaces of symbiotic algae after they were cultivated for 10 h. The cavities enlarged and the cell contents were lost with extended cultivation. Our data suggested that the presence of cavities on symbiotic algae surfaces may be one of the main reasons for failure to culture symbiotic algae in an artificial medium.

Zhu, Baohua; Pan, Kehou; Wang, Guangce

2008-02-01

382

Environmental impacts of algae-derived biodiesel and bioelectricity for transportation.  

PubMed

Algae are a widely touted source of bioenergy with high yields, appreciable lipid contents, and an ability to be cultivated on marginal land without directly competing with food crops. Nevertheless, recent work has suggested that large-scale deployment of algae bioenergy systems could have unexpectedly high environmental burdens. In this study, a "well-to-wheel" life cycle assessment was undertaken to evaluate algae's potential use as a transportation energy source for passenger vehicles. Four algae conversion pathways resulting in combinations of bioelectricity and biodiesel were assessed for several relevant nutrient procurement scenarios. Results suggest that algae-to-energy systems can be either net energy positive or negative depending on the specific combination of cultivation and conversion processes used. Conversion pathways involving direct combustion for bioelectricity production generally outperformed systems involving anaerobic digestion and biodiesel production, and they were found to generate four and fifteen times as many vehicle kilometers traveled (VKT) per hectare as switchgrass or canola, respectively. Despite this, algae systems exhibited mixed performance for environmental impacts (energy use, water use, and greenhouse gas emissions) on a "per km" basis relative to the benchmark crops. This suggests that both cultivation and conversion processes must be carefully considered to ensure the environmental viability of algae-to-energy processes. PMID:21774477

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

2011-09-01

383

Can benthic algae mediate larval behavior and settlement of the coral Acropora muricata?  

NASA Astrophysics Data System (ADS)

The resilience of coral reefs relies significantly on the ability of corals to recover successfully in algal-dominated environments. Larval settlement is a critical but highly vulnerable stage in the early life history of corals. In this study, we analyzed how the presence of two upright fleshy algae, Sargassum mcclurei (SM) and Padina australis (PA), and one crustose coralline algae, Mesophyllum simulans (MS), affects the settlement of Acropora muricata larvae. Coral larvae were exposed to seawater flowing over these algae at two concentrations. Larval settlement and mortality were assessed daily through four variables related to their behavior: swimming, substratum testing, metamorphosis, and stresses. Temperature, dissolved oxygen, pH, algal growth, and photosynthetic efficiency were monitored throughout the experiment. Results showed that A. muricata larvae can settle successfully in the absence of external stimuli (63 ± 6 % of the larvae settled in control treatments). While algae such as MS may stimulate substrate testing and settlement of larvae in the first day after competency, they ultimately had a lower settlement rate than controls. Fleshy algae such as PA, and in a lesser measure SM, induced more metamorphosis than controls and seemed to eventually stimulate settlement. A diverse combination of signals and/or modifications of microenvironments by algae and their associated microbial communities may explain the pattern observed in coral settlement. Overall, this study contributes significantly to the knowledge of the interaction between coral and algae, which is critical for the resilience of the reefs.

Denis, V.; Loubeyres, M.; Doo, S. S.; de Palmas, S.; Keshavmurthy, S.; Hsieh, H. J.; Chen, C. A.

2014-06-01

384

Production and release of selenocyanate by different green freshwater algae in environmental and laboratory samples.  

PubMed

In a previous study, selenocyanate was tentatively identified as a biotransformation product when green algae were exposed to environmentally relevant concentrations of selenate. In this follow-up study, we confirm conclusively the presence of selenocyanate in Chlorella vulgaris culture medium by electrospray mass spectrometry, based on selenium's known isotopic pattern. We also demonstrate that the observed phenomenon extends to other green algae (Chlorella kesslerii and Scenedesmus obliquus) and at least one species of blue-green algae (Synechococcus leopoliensis). Further laboratory experiments show that selenocyanate production by algae is enhanced by addition of nitrate, which appears to serve as a source of cyanide produced in the algae. Ultimately, this biotransformation process was confirmed in field experiments where trace amounts of selenocyanate (0.215 ± 0.010 ppb) were observed in a eutrophic, selenium-impacted river with massive algal blooms, which consisted of filamentous green algae (Cladophora genus) and blue-green algae (Anabaena genus). Selenocyanate abundance was low despite elevated selenium concentrations, apparently due to suppression of selenate uptake by sulfate, and insufficient nitrogen concentrations. Finally, trace levels of several other unidentified selenium-containing compounds were observed in these river water samples; preliminary suggestions for their identities include thioselenate and small organic Se species. PMID:22455319

LeBlanc, Kelly L; Smith, Matthew S; Wallschläger, Dirk

2012-06-01

385

Possible future effects of large-scale algae cultivation for biofuels on coastal eutrophication in Europe.  

PubMed

Biodiesel is increasingly considered as an alternative for fossil diesel. Biodiesel can be produced from rapeseed, palm, sunflower, soybean and algae. In this study, the consequences of large-scale production of biodiesel from micro-algae for eutrophication in four large European seas are analysed. To this end, scenarios for the year 2050 are analysed, assuming that in the 27 countries of the European Union fossil diesel will be replaced by biodiesel from algae. Estimates are made for the required fertiliser inputs to algae parks, and how this may increase concentrations of nitrogen and phosphorus in coastal waters, potentially leading to eutrophication. The Global NEWS (Nutrient Export from WaterSheds) model has been used to estimate the transport of nitrogen and phosphorus to the European coastal waters. The results indicate that the amount of nitrogen and phosphorus in the coastal waters may increase considerably in the future as a result of large-scale production of algae for the production of biodiesel, even in scenarios assuming effective waste water treatment and recycling of waste water in algae production. To ensure sustainable production of biodiesel from micro-algae, it is important to develop cultivation systems with low nutrient losses to the environment. PMID:25058933

Blaas, Harry; Kroeze, Carolien

2014-10-15

386

Feeding Preferences and the Nutritional Value of Tropical Algae for the Abalone Haliotis asinina  

PubMed Central

Understanding the feeding preferences of abalone (high-value marine herbivores) is integral to new species development in aquaculture because of the expected link between preference and performance. Performance relates directly to the nutritional value of algae – or any feedstock – which in turn is driven by the amino acid content and profile, and specifically the content of the limiting essential amino acids. However, the relationship between feeding preferences, consumption and amino acid content of algae have rarely been simultaneously investigated for abalone, and never for the emerging target species Haliotis asinina. Here we found that the tropical H. asinina had strong and consistent preferences for the red alga Hypnea pannosa and the green alga Ulva flexuosa, but no overarching relationship between protein content (sum of amino acids) and preference existed. For example, preferred Hypnea and Ulva had distinctly different protein contents (12.64 vs. 2.99 g 100 g?1) and the protein-rich Asparagopsis taxiformis (>15 g 100 g?1 of dry weight) was one of the least preferred algae. The limiting amino acid in all algae was methionine, followed by histidine or lysine. Furthermore we demonstrated that preferences can largely be removed using carrageenan as a binder for dried alga, most likely acting as a feeding attractant or stimulant. The apparent decoupling between feeding preference and algal nutritive values may be due to a trade off between nutritive values and grazing deterrence associated with physical and chemical properties. PMID:22719967

Angell, Alex R.; Pirozzi, Igor; de Nys, Rocky; Paul, Nicholas A.

2012-01-01

387

[Mechanism of the inhibitory action of allelochemical dibutyl phthalate on algae Gymnodinium breve].  

PubMed

The aim of this study was to investigate the mechanism of inhibitory action of dibutyl phthalate (DBP) on red tide algae Gymnodinium breve. The effects of DBP on malonaldehyde, subcellular structure and superoxide dismutase (SOD) isoforms were investigated. The results showed that MDA accumulated in the algae cell under DBP exposure, and for the 3 mg x L(-1) DBP treated algae culture a peak value of 0.34 micromol x (10(9) cells) (-1) occurred at 72 h, which was about 2. 3 times than that of the control. TEM pictures showed the disruption of DBP on the subcellular structure of G. breve. A morphological phenomenon appeared that the algae cell was commonly found small tubules or apical parts around the cell membrane, and almost all normal cell organelles were indistinguishable finally. The activity of CuZn-SOD (main cytoplast located isoform with little in cloroplast) under DBP exposure was higher than that of the control, and no significant difference was observed on Fe-SOD (chloroplast located isoform) activity, but for the Mn-SOD (mitochondrial isoform), the activity was significantly inhibited. These results indicated that DBP might inhibit the algae growth from the plasma membrane and the mitochondria, resulting in oxidative damage in algae cell and a final death. This paper will give a theoretical support to the practical usage of the allelochemical on red tide algae. PMID:22452215

Bie, Cong-Cong; Li, Feng-Min; Wang, Yi-Fei; Wang, Hao-Yun; Zhao, Ya-Han; Zhao, Wei; Wang, Zhen-Yu

2012-01-01

388

Combining micro-structures and micro-algae to increase lipid production for bio-fuel  

NASA Astrophysics Data System (ADS)

3rd generation bio-fuels like lipid producing micro-algae are a promising source of energy that could replace our dependence on petroleum. However, until there are improvements in algae oil yields, and a reduction in the energy needed for processing, algae bio-fuels are not economically competitive with petroleum. Here, we describe our work combining micro-fabricated devices with micro-algae Neochloris oleoabundans, a species first isolated on the sand dunes of Saudi Arabia. Inserting micro-algae of varying fitness into a landscape of micro-habitats allows us to evolve and select them based on a variety of conditions like specific gravity, starvation response and Nile Red fluorescence (which is a marker for lipid production). Hence, we can both estimate the production of lipids and generate conditions that allow the creation and isolation of algae which produce higher amounts of lipids, while discarding the rest. Finally, we can use micro-fabricated structures and flocculation to de-water these high lipid producing algae, reducing the need for expensive centrifugation and filtration.

Vyawahare, Saurabh; Zhu, Emilly; Mestler, Troy; Estévez-Torres, André.; Austin, Robert

2011-03-01

389

Enhanced Genetic Tools for Engineering Multigene Traits into Green Algae  

PubMed Central

Transgenic microalgae have the potential to impact many diverse biotechnological industries including energy, human and animal nutrition, pharmaceuticals, health and beauty, and specialty chemicals. However, major obstacles to sophisticated genetic and metabolic engineering in algae have been the lack of well-characterized transformation vectors to direct engineered gene products to specific subcellular locations, and the inability to robustly express multiple nuclear-encoded transgenes within a single cell. Here we validate a set of genetic tools that enable protein targeting to distinct subcellular locations, and present two complementary methods for multigene engineering in the eukaryotic green microalga Chlamydomonas reinhardtii. The tools described here will enable advanced metabolic and genetic engineering to promote microalgae biotechnology and product commercialization. PMID:24710110

Rasala, Beth A.; Chao, Syh-Shiuan; Pier, Matthew; Barrera, Daniel J.; Mayfield, Stephen P.

2014-01-01

390

Ocean Flowers: Anna Atkinsâ??s Cyanotypes of British Algae  

NSDL National Science Digital Library

In the middle of the 19th century, Anna Atkins wondered how she might be able to create accurate impressions of algae specimens. She was an amateur botanist who was primarily interested in the art and science of taxonomy and scientific illustration. After a long period of experimentation, she came up with the idea of using an existing blueprinting process to create the multiple copies that would later back her â??Photographs of British Algaeâ?. This was also the first photographic work by a woman, and also the first book produced entirely by photographic means. Thanks to the fine work of the staff at the New York Public Libraryâ??s Digital Gallery, interested parties can browse through this monumental achievement at their leisure. Visitors can search the entire work, or just browse through the 285 images. As one might imagine, each image is accompanied with a complete bibliographic record.

2006-01-01

391

Chloroplast Protein Synthesis in the Chromophytic Alga Olisthodiscus luteus12  

PubMed Central

This study represents the first report on chloroplast protein synthesis during the synchronous cell growth of a chromophytic (chlorophyll a,c) plant. When the unicellular alga Olisthodiscus luteus is maintained on a 12-hour light:12-hour dark cycle, cell and chloroplast number double every 24 hours. A temporal separation between these two events occurs. Measurements of chloroplast and total cellular protein values suggest that polypeptide synthesis occurs mainly in the light portion of the cell cycle, and pulse chase studies demonstrate that chloroplast proteins made in the light are not degraded in the dark. Data support the following conclusions: (a) a similar complement of chloroplast DNA coded proteins is made at all phases of the light portion of the cell cycle, and (b) chloroplast protein synthesis is a light rather than a cell cycle mediated response. Images Fig. 2 Fig. 3 Fig. 4 PMID:16664376

Reith, Michael E.; Cattolico, Rose Ann

1985-01-01

392

Extranuclear DNA of a Marine Chromophytic Alga : RESTRICTION ENDONUCLEASE ANALYSIS.  

PubMed

Two extranuclear DNA species have been isolated from the marine alga Olisthodiscus luteus. Rapid lysis of cells followed by the immediate addition of CsCl to the lysate was critical to the preservation of these satellite DNA species. Restriction endonuclease analysis demonstrates a molecular weight of 99 x 10(6) for chloroplast DNA and 23 x 10(6) for a second satellite species. The origin of the second satellite is not known. However, this smaller satellite DNA which originates from a nonnuclear, DNAse insensitive cellular component, displays no sequence homology with ctDNA by hybridization experiments. Constancy of restriction endonuclease fragment patterns of chloroplast and second satellite species during all phases of the growth cycle, whether cultures were maintained synchronously or asynchronously, was demonstrated. PMID:16662368

Aldrich, J; Gelvin, S; Cattolico, R A

1982-05-01

393

Chloroplast ribosomal DNA organization in the chromophytic alga Olisthodiscus luteus.  

PubMed

There are almost no data describing chloroplast genome organization in chromophytic (chlorophyll a/c) plants. In this study chloroplast ribosomal operon placement and gene organization has been determined for the golden-brown alga Olisthodiscus luteus. Ribosomal RNA genes are located on the chloroplast DNA inverted repeat structure. Nucleotide sequence analysis, demonstrated that in contrast to the larger spacer regions in land plants, the 16S-23S rDNA spacer of O. luteus is only 265 bp in length. This spacer contains tRNA(Ile) and tRNA(Ala) genes which lack introns and are separated by only 3 bp. The sequences of the tRNA genes and 16S and 23S rDNA termini flanking the spacer were examined to determine homology between O. luteus, chlorophytic plant chloroplast DNA, and prokaryotes. PMID:2766384

Delaney, T P; Cattolico, R A

1989-03-01

394

Extranuclear DNA of a Marine Chromophytic Alga 1  

PubMed Central

Two extranuclear DNA species have been isolated from the marine alga Olisthodiscus luteus. Rapid lysis of cells followed by the immediate addition of CsCl to the lysate was critical to the preservation of these satellite DNA species. Restriction endonuclease analysis demonstrates a molecular weight of 99 × 106 for chloroplast DNA and 23 × 106 for a second satellite species. The origin of the second satellite is not known. However, this smaller satellite DNA which originates from a nonnuclear, DNAse insensitive cellular component, displays no sequence homology with ctDNA by hybridization experiments. Constancy of restriction endonuclease fragment patterns of chloroplast and second satellite species during all phases of the growth cycle, whether cultures were maintained synchronously or asynchronously, was demonstrated. Images PMID:16662368

Aldrich, Jane; Gelvin, Stanton; Cattolico, Rose Ann

1982-01-01

395

A new ketosteroid from red alga Acanthophora spicifera  

NASA Astrophysics Data System (ADS)

A new ketosteroid, along with six known steroids, was isolated from the ethanolic extracts of red alga Acanthophora spicifera (Vahl.) Boergesen. The structures, identified using chemical and spectroscopic methods including 2D NMR, were: (1) 22-hydroxy-5?-cholest-3,6-dione, (2) 6-hydroxycholest-4-ene-3-one, (3) cholest-4-ene-3,6-dione, (4) cholest-5-ene-3?-ol, (5) 5?-cholestane-3,6-dione, (6) ?-Sitosterol and (7) Saringosterol. The MTT method was used to test the cytotoxicity of the compounds against the human cancer cell lines, HCT-8, Bel-7402, BGC-823, A549 and HELA. Compounds 1, 2, 3 and 5 showed moderate cytotoxic activity against human cancer cell lines.

Shi, Dayong; Guo, Shuju; Fan, Xiao

2011-05-01

396

AIDS-antiviral sulfolipids from cyanobacteria (blue-green algae).  

PubMed

A recently developed tetrazolium-based microculture assay was used to screen extracts of cultured cyanobacteria (blue-green algae) for inhibition of the cytopathic effects of the human immunodeficiency virus (HIV-1), which is implicated as a causative agent of AIDS. A number of extracts were found to be remarkably active against the AIDS virus. A new class of HIV-1-inhibitory compounds, the sulfonic acid-containing glycolipids, was discovered through the use of the microculture assay to guide the fractionation and purification process. The pure compounds were active against HIV-1 in cultured human lymphoblastoid CEM, MT-2, LDV-7, and C3-44 cell lines in the tetrazolium assay as well as in p24 viral protein and syncytium formation assays. PMID:2502635

Gustafson, K R; Cardellina, J H; Fuller, R W; Weislow, O S; Kiser, R F; Snader, K M; Patterson, G M; Boyd, M R

1989-08-16

397

Testing an Algae-Based Air-Regeneration System  

NASA Technical Reports Server (NTRS)

The potential of an air-regeneration system based on the growth of unicellular algae on the surface of porous ceramic tubes was evaluated. The system is fairly robust with respect to environmental conditions and is capable of maintaining algal cultures for up to 365 days. Under standard conditions (50-66 micro mol/sq mm s (PPF), 450 micro mol mol of CO2), mature tubes can remove CO2 at a rate of up to 90 micro mol/sq m min. Under these conditions, approximately 200 square meters of area would be required for each member of the crew. However, the rate of uptake increases with both photon flux and CO2 concentration in accordance with Michaelis-Menton dynamics. An extrapolation to conditions of saturating light and carbon dioxide indicates that the area required can be reduced by a factor of at least 2.5.

Nienow, James

1998-01-01

398

The effect of low temperature on Antarctic endolithic green algae  

NASA Technical Reports Server (NTRS)

Laboratory experiments show that undercooling to about -5 degrees C occurs in colonized Beacon sandstones of the Ross Desert, Antarctica. High-frequency temperature oscillations between 5 degrees C and -5 degrees C or -10 degrees C (which occur in nature on the rock surface) did not damage Hemichloris antarctica. In a cryomicroscope, H. antarctica appeared to be undamaged after slow or rapid cooling to -50 degrees C. 14CO2 incorporation after freezing to -20 degrees C was unaffected in H. antarctica or in Trebouxia sp. but slightly depressed in Stichococcus sp. (isolated from a less extreme Antarctic habitat). These results suggest that the freezing regime in the Antarctic desert is not injurious to endolithic algae. It is likely that the freezing-point depression inside the rock makes available liquid water for metabolic activity at subzero temperatures. Freezing may occur more frequently on the rock surface and contribute to the abiotic nature of the surface.

Meyer, M. A.; Morris, G. J.; Friedmann, E. I.

1988-01-01

399

Simultaneous coupling of phototaxis and electrotaxis in Volvox algae  

NASA Astrophysics Data System (ADS)

In nature, living creatures are affected by several stimuli simultaneously. The response of living creatures to stimuli is called taxis. In order to reveal the principles of taxis behavior in response to complex stimuli, we simultaneously applied photostimulation and electric stimulation perpendicularly to a Volvox algae solution. The probability distribution of the swimming direction showed that a large population of swimming cells moved in a direction that was the result of the composition of phototaxis and electrotaxis. More surprisingly, we uncovered the coupling of signs of taxis, i.e., coupling of phototaxis and electrotaxis induced positive electrotaxis, which did not emerge in the single stimulation experiments. We qualitatively explained the coupling of taxis based on the polarization of the swimming cells induced by the simultaneous photo- and electric stimulation.

Hayashi, Yoshikatsu; Sugawara, Ken

2014-04-01

400

Eyespot placement and assembly in the green alga Chlamydomonas.  

PubMed

The eyespot organelle of the green alga Chlamydomonas allows the cell to phototax toward (or away) from light to maximize the light intensity for photosynthesis and minimize photo-damage. At cytokinesis, the eyespot is resorbed at the cleavage furrow and two new eyespots form in the daughter cells 180 degrees from each other. The eyespots are positioned asymmetrically with respect to the microtubule cytoskeleton. Eyespots are assembled from all three chloroplast membranes and carotenoid-filled granules, which form a sandwich structure overlaid by the tightly apposed plasma membrane. This review describes (1) my interest in cellular asymmetry and organelle biology, (2) isolation of mutations that describe four genes governing eyespot placement and assembly, (3) the characterization of the EYE2 gene, which encodes a thioredoxin superfamily member, and (4) the characterization of the MIN1 gene, which is required for the layered organization of granules and membranes in the eyespot. BioEssays 25:410-416, 2003. PMID:12655648

Dieckmann, Carol L

2003-04-01

401

Photoperiod influences endogenous indoleamines in cultured green alga Dunaliella bardawil.  

PubMed

Effect of light intensity and photoperiod on growth, indoleamines and carotenoid production was studied in unicellular green algae D. bardawil. Maximum biomass and carotenoid contents were found when cultures were grown in light (intensity of 2.0 Klux) at a photoperiod of 16/8h light and dark cycle. There was a profound influence of tested photoperiod conditions of light:dark viz. 8:16, 10:14, and 12:12 hr, continuous light on indoleamines (SER and MEL) production as estimated by HPLC and confirmed by mass spectral data obtained from LC-MS-ESI studies. Serotonin level increased from 908 to 1765 pg/g fresh wt with increase in light duration and melatonin level increased from 267 to 584 pg/g fresh wt during increase in dark phase. Carotenoids production was high in continuous light than other tested conditions. PMID:21452604

Ramakrishna, A; Dayananda, C; Giridhar, P; Rajasekaran, T; Ravishankar, G A

2011-03-01

402

Bioactive Chemical Constituents from the Brown Alga Homoeostrichus formosana  

PubMed Central

A new chromene derivative, 2-(4',8'-dimethylnona-3'E,7'-dienyl)-8-hydroxy-2,6-dimethyl-2H-chromene (1) together with four known natural products, methylfarnesylquinone (2), isololiolide (3), pheophytin a (4), and ?-carotene (5) were isolated from the brown alga Homoeostrichus formosana. The structure of 1 was determined by extensive 1D and 2D spectroscopic analyses. Acetylation of 1 yielded the monoacetylated derivative 2-(4',8'-dimethylnona-3'E,7'-dienyl)-8-acetyl-2,6-dimethyl-2H-chromene (6). Compounds 1–6 exhibited various levels of cytotoxic, antibacterial, and anti-inflammatory activities. Compound 2 was found to display potent in vitro anti-inflammatory activity by inhibiting the generation of superoxide anion (IC50 0.22 ± 0.03 ?g/mL) and elastase release (IC50 0.48 ± 0.11 ?g/mL) in FMLP/CB-induced human neutrophils. PMID:25561228

Fang, Hui-Yu; Chokkalingam, Uvarani; Chiou, Shu-Fen; Hwang, Tsong-Long; Chen, Shu-Li; Wang, Wei-Lung; Sheu, Jyh-Horng

2014-01-01

403

Bioconvection in a suspension of isotropically scattering phototactic algae  

NASA Astrophysics Data System (ADS)

Phototaxis is a directed swimming response toward a light source sensed by micro-organisms. Positive phototaxis represents swimming toward the source of light intensity and negative phototaxis is the swimming away from it. In this paper we develop a new model for phototaxis that incorporates the effects of absorption and scattering by the micro-organisms. This model is then used to analyze the linear stability of a suspension of phototactic algae illuminated by a collimated radiation at the top. A comprehensive numerical study of the linear stability is presented with particular emphasis on the scattering effect. As a result of scattering, for some parameter values, the micro-organisms accumulate in two horizontal layers at different depths in the basic equilibrium state. Examples of oscillatory instabilities are also found.

Ghorai, S.; Panda, M. K.; Hill, N. A.

2010-07-01

404

Quantification of floating macroalgae blooms using the scaled algae index  

NASA Astrophysics Data System (ADS)

Quantifying the spatial coverage of floating macroalgae from satellite imagery, using methods such as the normalized difference vegetation index (NDVI) and the floating algae index (FAI), requires the use of a scene-wide threshold to isolate and then compute the number of floating macroalgae pixels. The problem faced is the sensitivity of the NDVI and, to a lesser extent, the FAI to radiance contributions from atmospheric aerosols and turbid water. Both these factors can vary significantly across a satellites' field-of-view generating irregular apparent reflectance of ocean and floating macroalgae pixels across an NDVI/FAI scene, leading to inaccuracies in spatial coverage estimates. We present a simple image processing algorithm, termed the scaled algae index (SAI), that removes any variability present in ocean and floating macroalgae pixels in NDVI or FAI imagery. The SAI does this by subtracting a given pixel's index by that of a local ocean pixel, effectively scaling ocean pixels to values near zero, and macroalgae pixels to positive values. The SAI algorithm has been tested on NDVI and FAI scenes of the 2008/2009 floating macroalgae blooms that occurred in the Yellow Sea, China. These SAI images show a major reduction in variability with scene-wide histograms being unimodal. Histogram analysis also indicates that sufficient contrast exists between ocean and floating macroalgae pixels to enable segmentation by a scene-wide threshold. A semiautomated threshold determination procedure is also presented, which together with the SAI algorithm can be used to compute accurate estimates of the spatial coverage of floating macroalgae.

Garcia, Rodrigo A.; Fearns, Peter; Keesing, John K.; Liu, Dongyan

2013-01-01

405

Mannitol metabolism in brown algae involves a new phosphatase family.  

PubMed

Brown algae belong to a phylogenetic lineage distantly related to green plants and animals, and are found predominantly in the intertidal zone, a harsh and frequently changing environment. Because of their unique evolutionary history and of their habitat, brown algae feature several peculiarities in their metabolism. One of these is the mannitol cycle, which plays a central role in their physiology, as mannitol acts as carbon storage, osmoprotectant, and antioxidant. This polyol is derived directly from the photoassimilate fructose-6-phosphate via the action of a mannitol-1-phosphate dehydrogenase and a mannitol-1-phosphatase (M1Pase). Genome analysis of the brown algal model Ectocarpus siliculosus allowed identification of genes potentially involved in the mannitol cycle. Among these, two genes coding for haloacid dehalogenase (HAD)-like enzymes were suggested to correspond to M1Pase activity, and thus were named EsM1Pase1 and EsM1Pase2, respectively. To test this hypothesis, both genes were expressed in Escherichia coli. Recombinant EsM1Pase2 was shown to hydrolyse the phosphate group from mannitol-1-phosphate to produce mannitol but was not active on the hexose monophosphates tested. Gene expression analysis showed that transcription of both E. siliculosus genes was under the influence of the diurnal cycle. Sequence analysis and three-dimensional homology modelling indicated that EsM1Pases, and their orthologues in Prasinophytes, should be seen as founding members of a new family of phosphatase with original substrate specificity within the HAD superfamily of proteins. This is the first report describing the characterization of a gene encoding M1Pase activity in photosynthetic organisms. PMID:24323504

Groisillier, Agnès; Shao, Zhanru; Michel, Gurvan; Goulitquer, Sophie; Bonin, Patricia; Krahulec, Stefan; Nidetzky, Bernd; Duan, Delin; Boyen, Catherine; Tonon, Thierry

2014-02-01

406

Comparing the effects of symbiotic algae (Symbiodinium) clades C1 and D on early growth stages of Acropora tenuis.  

PubMed

Reef-building corals switch endosymbiotic algae of the genus Symbiodinium during their early growth stages and during bleaching events. Clade C Symbiodinium algae are dominant in corals, although other clades - including A and D - have also been commonly detected in juvenile Acroporid corals. Previous studies have been reported that only molecular data of Symbiodinium clade were identified within field corals. In this study, we inoculated aposymbiotic juvenile polyps with cultures of clades C1 and D Symbiodinium algae, and investigated the different effect of these two clades of Symbiodinium on juvenile polyps. Our results showed that clade C1 algae did not grow, while clade D algae grew rapidly during the first 2 months after inoculation. Polyps associated with clade C1 algae exhibited bright green fluorescence across the body and tentacles after inoculation. The growth rate of polyp skeletons was lower in polyps associated with clade C1 algae than those associated with clade D algae. On the other hand, antioxidant activity (catalase) of corals was not significantly different between corals with clade C1 and clade D algae. Our results suggested that clade D Symbiodinium algae easily form symbiotic relationships with corals and that these algae could contribute to coral growth in early symbiosis stages. PMID:24914677

Yuyama, Ikuko; Higuchi, Tomihiko

2014-01-01

407

Comparing the Effects of Symbiotic Algae (Symbiodinium) Clades C1 and D on Early Growth Stages of Acropora tenuis  

PubMed Central

Reef-building corals switch endosymbiotic algae of the genus Symbiodinium during their early growth stages and during bleaching events. Clade C Symbiodinium algae are dominant in corals, although other clades — including A and D — have also been commonly detected in juvenile Acroporid corals. Previous studies have been reported that only molecular data of Symbiodinium clade were identified within field corals. In this study, we inoculated aposymbiotic juvenile polyps with cultures of clades C1 and D Symbiodinium algae, and investigated the different effect of these two clades of Symbiodinium on juvenile polyps. Our results showed that clade C1 algae did not grow, while clade D algae grew rapidly during the first 2 months after inoculation. Polyps associated with clade C1 algae exhibited bright green fluorescence across the body and tentacles after inoculation. The growth rate of polyp skeletons was lower in polyps associated with clade C1 algae than those associated with clade D algae. On the other hand, antioxidant activity (catalase) of corals was not significantly different between corals with clade C1 and clade D algae. Our results suggested that clade D Symbiodinium algae easily form symbiotic relationships with corals and that these algae could contribute to coral growth in early symbiosis stages. PMID:24914677

Yuyama, Ikuko; Higuchi, Tomihiko

2014-01-01

408

Effects of extreme seasonality on community structure and functional group dynamics of coral reef algae in the southern Red Sea (Eritrea)  

Microsoft Academic Search

Spatial and temporal variation in the biomass of four functional groups of coral reef algae (canopy algae, foliose algae, turf algae and crustose corallines) was investigated in the southern Red Sea. This region is characterised by extremely high summer temperatures (ca. 35°C). Strong seasonal shifts in the relative contribution of each group to the total macroalgal biomass were observed. On

M. Ateweberhan; J. H. Bruggemann; A. M. Breeman

2006-01-01

409

Aquaculture: Algae. (Latest citations from the Life Sciences collection database). Published Search  

SciTech Connect

The bibliography contains citations concerning the commercial cultivation of algae as a facet of aquaculture. Topics include descriptions and characteristics of algal species, environmental variables affecting productivity, nutritional aspects, infestation and disease, genetic manipulation, and production technology. End product applications examine algae as biomass for energy production, food source for humans, animal feed source, and a source for chemical by-products such as chlorophylls. Harvesting of algae as a source of single-celled protein is referenced in a related bibliography. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

NONE

1996-04-01

410

Aquaculture: Algae. (Latest citations from the Life Sciences Collection data base). Published Search  

SciTech Connect

The bibliography contains citations concerning the commercial cultivation of algae as a facet of aquaculture. Topics include descriptions and characteristics of algal species, environmental variables affecting productivity, nutritional aspects, infestation and disease, genetic manipulation, and production technology. End product applications examine algae as biomass for energy production, food source for humans, animal feed source, and a source for chemical by-products such as chlorophylls. Harvesting of algae as a source of single-celled protein is referenced in a related bibliography. (Contains a minimum of 171 citations and includes a subject term index and title list.)

Not Available

1992-05-01

411

The Culture Collection of Algae at University of Texas-Austin  

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." 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.

412

Compsopogon cf. coeruleus, a benthic red alga (Rhodophyta) new to the Laurentian Great Lakes  

USGS Publications Warehouse

We found Compsopogon cf. coeruleus for the first time in the Laurentian Great Lakes, growing on limestone rocks at a depth of 21 m on Six Fathom Bank in central Lake Huron. It is the first freshwater red alga to be found in the Great Lakes and the only red alga ever found on an offshore reef in the Great Lakes. However, because this alga usually inhabits water 10-28A?C and has not survived freezing winter temperatures elsewhere, it may not be a permanent member of the flora.

Manny, Bruce A.; Edsall, Thomas A.; Wujek, Daniel E.

1991-01-01

413

Epiphytic algae on mosses in the Altindere Valley National Park (Maçka-Trabzon/Turkey).  

PubMed

Species composition and abundance of epiphytic algae on mosses growing in the Altindere Valley National Park were investigated in March 2008. The epiphytic algae identified in these samples were 27 species in total, 15 of the Bacillariophyta, 7 of the Cyanophyta, 4 of the Chlorophyta and a single of the Euglenophyta species. The members of the Bacillariophyta were more frequently found among these epiphytic algae on mosses. Netrium digitus (Ehrenb.) Itzigs and Rothe var. curtum (Borge) Willi Krieg. was recorded for the first time in the desmids flora of Turkey. The epiphytic algal flora on mosses at the submerged habitat was the richest of the three habitats. PMID:19137841

Sahin, B; Ozdemir, T

2008-09-15

414

Impact of green algae on the measurement of Microcystis aeruginosa populations in lagoon-treated wastewater with an algae online analyser.  

PubMed

Tests on the algae online analyser (AOA) showed that there was a strong direct linear correlation between cell density and in vivo Chl-a concentration for M. aeruginosa over the range of interest for a biologically treated effluent at a wastewater treatment plant (25,000-65,000?cells?mL(-1), equivalent to a biovolume of 2-6?mm(3?)L(-1)). However, the AOA can provide an overestimate or underestimate of M. aeruginosa populations when green algae are present in the effluent, depending on their species and relative numbers. The results from this study demonstrated that the green algae (e.g., Euglena gracilis, Chlorella sp.) in the field phytoplankton population should be considered during calibration. In summary, the AOA has potential for use as an alert system for the presence of M. aeruginosa, and thus potentially of cyanobacterial blooms, in wastewater stabilization ponds. PMID:25204421

Nguyen, Thang; Roddick, Felicity A; Fan, Linhua

2015-03-01

415

Benchmark study on algae harvesting with backwashable submerged flat panel membranes.  

PubMed

The feasibility of algae harvesting with submerged flat panel membranes was investigated as pre-concentration step prior to centrifugation. Polishing of the supernatant coming from the centrifuge was evaluated as well. The effect of membrane polymer (polyvinyl chloride [PVC], polyethersulfone polyvinyl-pyrollidone [PES-PVP], poly vinylidene fluoride [PVDF]), pore size (microfiltration [MF], ultrafiltration [UF]), algae cell concentrations and species were investigated at lab-scale. In addition, backwashing as fouling control was compared to standard relaxation. PVDF was the superior polymer, and UF showed better fouling resistance. Backwashing outperformed relaxation in fouling control. The backwashable membranes allowed up to 300% higher fluxes compared to commercial flat panel benchmark (PVC) membranes. Estimations on energy consumption for membrane filtration followed by centrifugation revealed relatively low values of 0.169 kW h/kg of dry weight of algae compared to 0.5 kW h/kg for algae harvesting via classical centrifuge alone. PMID:23274222

De Baerdemaeker, Tom; Lemmens, Bert; Dotremont, Chris; Fret, Jorien; Roef, Luc; Goiris, Koen; Diels, Ludo

2013-02-01

416

Numerical prediction of algae cell mixing feature in raceway ponds using particle tracing methods.  

PubMed

In the present study, a novel technique, which involves numerical computation of the mixing length of algae particles in raceway ponds, was used to evaluate the mixing process. A value of mixing length that is higher than the maximum streamwise distance (MSD) of algae cells indicates that the cells experienced an adequate turbulent mixing in the pond. A coupling methodology was adapted to map the pulsating effects of a 2D paddle wheel on a 3D raceway pond in this study. The turbulent mixing was examined based on the computations of mixing length, residence time, and algae cell distribution in the pond. The results revealed that the use of particle tracing methodology is an improved approach to define the mixing phenomenon more effectively. Moreover, the algae cell distribution aided in identifying the degree of mixing in terms of mixing length and residence time. Biotechnol. Bioeng. 2015;112: 297-307. © 2014 Wiley Periodicals, Inc. PMID:25163842

Ali, Haider; Cheema, Taqi A; Yoon, Ho-Sung; Do, Younghae; Park, Cheol W

2015-02-01

417

The Antimicrobial Properties of Red Algae. The Fight of Your Life: Battling Bacteria.  

ERIC Educational Resources Information Center

Describes a research project in which a professor and a student collaborated in the screening of macroscopic algae for antimicrobial properties. Includes background information, materials and methods, results, and a discussion of the experiment. (SAH)

Case, Christine L.; Warner, Michael

2001-01-01

418

The concentration of radium, thorium, and uranium by tropical marine algae  

Microsoft Academic Search

Twenty species of marine algae were collected between 1961 and 1968 from coastal waters of Puerto Rico and analyzed chemically for total organic material, protein nitrogen, and calcium, and radiochemically for the naturally occurring alpha particle emitters 228Ra, \\

DAVID N. EDGINGTON; SOLON A. GORDON; MICHAEL M. THOMMES; LUIS R. ALMODOVAR

1970-01-01

419

Relationship between the Unicellular Red Alga Porphyridium sp. and Its Predator, the Dinoflagellate Gymnodinium sp  

PubMed Central

Contamination of algae cultivated outdoors by various microorganisms, such as bacteria, fungi, algae, and protozoa, can affect growth and product quality, sometimes causing fast collapse of the cultures. The main contaminant of Porphyridium cultures grown outdoors in Israel is a Gymnodinium sp., a dinoflagellate that feeds on the alga. Comparison of the effects of various environmental conditions, i.e., pH, salinity, and temperature, on Gymnodinium and Porphyridium species revealed that the Gymnodinium sp. has sharp optimum curves, whereas the Porphyridium sp. has a wider range of optimum conditions and is also more resistant to extreme environmental variables. The mode of preying on the alga was observed, and the specificity of the Gymnodinium sp. for the Porphyridium sp. was shown. In addition, Gymnodinium extract was shown to contain enzymatic degrading activity specific to the Porphyridium sp. cell wall polysaccharide. PMID:16348059

Ucko, Michal; Cohen, Ephraim; Gordin, Hillel; Arad, Shoshana (Malis)

1989-01-01

420

A geometrical approach explains Lake Ball (Marimo) formations in the green alga, Aegagropila linnaei  

PubMed Central

An extremely rare alga, Aegagropila linnaei, is known for its beautiful spherical filamentous aggregations called Lake Ball (Marimo). It has long been a mystery in biology as to why this species forms 3D ball-like aggregations. This alga also forms two-dimensional mat-like aggregations. Here we show that forming ball-like aggregations is an adaptive strategy to increase biomass in the extremely limited environments suitable for growth of this alga. We estimate the maximum biomass attained by ball colonies and compare it to that attained by mat colonies. As a result, a ball colony can become larger in areal biomass than the mat colony. In the two large ball colonies studied so far, they actually have larger biomasses than the mat colonies. The uniqueness of Lake Balls in nature seems to be due to the rarity of such environmental conditions. This implies that the conservation of this alga is difficult, but important. PMID:24441685

Togashi, Tatsuya; Sasaki, Hironobu; Yoshimura, Jin

2014-01-01

421

A biologically active diphenyl ether from the green alga Cladophora fascicularis  

Microsoft Academic Search

Summary A new polybrominated diphenyl ether (1) has been isolated from the green algaCladaphora fascicularis, and the structure was determined by spectral analysis and conversion to known compounds. It showed antibacterial and antiinflammatory activities.

M. Kuniyoshi; K. Yamada; T. Higa

1985-01-01

422

Method and apparatus for detecting phycocyanin-pigmented algae and bacteria from reflected light  

NASA Technical Reports Server (NTRS)

The present invention relates to a method of detecting phycocyanin algae or bacteria in water from reflected light, and also includes devices for the measurement, calculation and transmission of data relating to that method.

Vincent, Robert (Inventor)

2013-01-01

423

Preliminary observations on the benthic marine algae of the Gorringe seabank (northeast Atlantic Ocean)  

NASA Astrophysics Data System (ADS)

Examination of marine samples collected in 2006 from the Gettysburg and Ormonde seamounts on the Gorringe seabank southwest of Portugal has revealed 29 benthic Chlorophyta, Phaeophyceae (Ochrophyta), and Rhodophyta that were identified provisionally to genus and to species. Combining lists for the present and a previous expedition brings the total of algae thus far recorded to 48. The brown alga Zonaria tournefourtii and the red alga Cryptopleura ramosa were the most abundant species in the present collections. The kelp Laminaria ochroleuca was present only in the Gettysburg samples while Saccorhiza polyschides was observed only on the Ormonde seamount. Comparisons with the benthic marine algae recorded on seamounts in the mid-Atlantic Azores archipelago show features in common, notably kelp forests of L. ochroleuca at depths below 30 m and Z. tournefortii dominance in shallower waters.

Tittley, Ian; da Silva Vaz Álvaro, Nuno Miguel; de Melo Azevedo Neto, Ana Isabel

2014-06-01

424

LIPID BIOMARKER CHARACTERIZATION OF BLOOM-RELATED DINOFLAGELLATES AND OTHER EUKARYOTIC ALGAE  

EPA Science Inventory

Marine eukaryotic algae synthesize an array of lipids of chemotaxonomic utility that are potentially valuable in characterizing phytoplankton communities. Sterols and photopigments characteristic of dinoflagellates are rarely found in other algal classes. Long chain (C28) highly ...

425

Method and apparatus for detecting phycocyanin-pigmented algae and bacteria from reflected light  

NASA Technical Reports Server (NTRS)

The present invention relates to a method of detecting phycocyanin algae or bacteria in water from reflected light, and also includes devices for the measurement, calculation and transmission of data relating to that method.

Vincent, Robert (Inventor)

2006-01-01

426

Light-emitting diodes for the illumination of algae in ecotoxicity testing.  

PubMed

Ecotoxic effects of chemicals, preparations, and environmental samples are routinely quantified in standardized algae growth inhibition tests using microalgae like Desmodesmus subspicatus. The intention of this investigation was to prove the suitability of light-emitting diodes (LEDs) as an alternative to tubular discharge lamps in algae growth inhibition tests. This was approached by demonstrating that growth of algae was similar with both illuminating devices. Growth factors of growth controls were determined using LEDs. Growth curves of different light intensities of LEDs were compared with those of tubular discharge lamps. By testing certain chemicals with both illumination methods comparable results for E(r)C50 values were obtained. It could be shown that small-scale construction of incubators using LEDs is possible and could be advantageous, especially for the illumination of algae in 96-well microplate growth inhibition assays. PMID:15526267

Michel, Karin; Eisentraeger, Adolf

2004-12-01

427

MODELING THE RESPONSE OF THE NUISANCE ALGA, 'CLADOPHORA GLOMERATA', TO REDUCTIONS IN PHOSPHORUS LOADING  

EPA Science Inventory

The mathematical model was developed to evaluate the impact of various phosphorus management strategies on nuisance growths of the filamentous alga Cladophora glomerata. The model was supported by intensive ecological studies and an extensive field monitoring program. The results...

428

Control and separation of algae particles from WSP effluent by using floating aquatic plant root mats.  

PubMed

In this paper, the potential uses of water hyacinth and its root mats for separating algae particles in the effluent from waste stabilization ponds (WSPs) were discussed. Pilot-scale integrated processes consisting of WSPs and multiple WHPs (water hyacinth ponds) were operated in order to extract effects of the root mats on the reduction of algae concentrations. Root mats in the bottom of WHPs separated significant amount of the algae cells through attachment as the effluent from WSPs passed through them. Attachment of the algae particles to the surface of live roots was found to be similar to adsorption phenomena but it lasted even at saturation, probably due to the continuous reproduction of active attachment sites by detachment and growth of the roots. Additionally, this paper discusses attachment mechanisms and other issues concerning design and polishing of the WSPs effluent by WHPs. PMID:11443978

Kim, Y; Kim, W J; Chung, P G; Pipes, W O

2001-01-01

429

INFLUENCE OF METHYL TERT-BUTYL ETHER (MTBE) ON LAKE WATER ALGAE: JOURNAL ARTICLE  

EPA Science Inventory

NRMRL-ADA-01209 Kampbell*, D.H., An, Y, and Williams, VR. Influence of Methyl tert-Butyl Ether (MTBE) on Lake Water Algae. Bulletin of Environmental Contamination and Toxicology 57 (4):675-681 (2001). ...

430

EFFECTS OF SELECTED WASTEWATER CHLORINATION PRODUCTS AND CAPTAN ON MARINE ALGAE  

EPA Science Inventory

Effects of stable chloro-organic compounds formed during chlorination of sewage effluents on growth of marine unicellular algae were determined. Captan suppressed growth of Dunaliella tertiolecta and Porphyridium cruentum at 5 ppm. Growth of Skeletonema costatum was inhibited by ...

431

CONTRIBUTION OF MARINE ALGAE TO TRIHALOMETHANE PRODUCTION IN CHLORINATED ESTUARINE WATER  

EPA Science Inventory

Three species of marine algae representing major taxonomic groups of phytoplankton, Isochrysis galbana (Chrysophyceae), Carteria sp. (Chlorophyceae), and Thalassiosira pseudonana (Bacillariphyceae), were utilized to investigate the potential of natural occurring chlorophyll a of ...

432

Re-utilization of Industrial CO2 for Algae Production Using a Phase Change Material  

SciTech Connect

This is the final report of a 36-month Phase II cooperative agreement. Under this project, Touchstone Research Laboratory (Touchstone) investigated the merits of incorporating a Phase Change Material (PCM) into an open-pond algae production system that can capture and re-use the CO2 from a coal-fired flue gas source located in Wooster, OH. The primary objective of the project was to design, construct, and operate a series of open algae ponds that accept a slipstream of flue gas from a coal-fired source and convert a significant portion of the CO2 to liquid biofuels, electricity, and specialty products, while demonstrating the merits of the PCM technology. Construction of the pilot facility and shakedown of the facility in Wooster, OH, was completed during the first two years, and the focus of the last year was on operations and the cultivation of algae. During this Phase II effort a large-scale algae concentration unit from OpenAlgae was installed and utilized to continuously harvest algae from indoor raceways. An Algae Lysing Unit and Oil Recovery Unit were also received and installed. Initial parameters for lysing nanochloropsis were tested. Conditions were established that showed the lysing operation was effective at killing the algae cells. Continuous harvesting activities yielded over 200 kg algae dry weight for Ponds 1, 2 and 4. Studies were conducted to determine the effect of anaerobic digestion effluent as a nutrient source and the resulting lipid productivity of the algae. Lipid content and total fatty acids were unaffected by culture system and nutrient source, indicating that open raceway ponds fed diluted anaerobic digestion effluent can obtain similar lipid productivities to open raceway ponds using commercial nutrients. Data were also collected with respect to the performance of the PCM material on the pilot-scale raceway ponds. Parameters such as evaporative water loss, temperature differences, and growth/productivity were tracked. The pond with the PCM material was consistently 2 to 5°C warmer than the control pond. This difference did not seem to increase significantly over time. During phase transitions for the PCM, the magnitude of the difference between the daily minimum and maximum temperatures decreased, resulting in smaller daily temperature fluctuations. A thin layer of PCM material reduced overall water loss by 74% and consistently provided algae densities that were 80% greater than the control pond.

Joseph, Brian

2013-12-31

433

Biosorption of Heavy Metal Ions to Brown Algae, Macrocystis pyrifera, Kjellmaniella crassiforia,and Undaria pinnatifida  

Microsoft Academic Search

A fundamental study of the application of brown algae to the aqueous-phase separation of toxic heavy metals was carried out. The biosorption characteristics of cadmium and lead ions were determined with brown algae,Macrocystis pyrifera, Kjellmaniella crassiforia,andUndaria pinnatifida.A metal binding model proposed by the authors was used for the description of metal binding data. The results showed that the biosorption of

Hideshi Seki; Akira Suzuki

1998-01-01

434

Drifting algae and fish: Implications of tropical Sargassum invasion due to ocean warming in western Japan  

NASA Astrophysics Data System (ADS)

Evidence is accumulating that the invasion and extinction of habitat-forming seaweed species alters coastal community structure and ecological services, but their effects on the pelagic environment have been largely ignored. Thus, we examined the seasonal occurrence patterns of indigenous temperate and invasive tropical drifting algae and associated fish species every month for 2 years (2009-2011) in western Japan (Tosa Bay), where a rapid shift from temperate to tropical Sargassum species has been occurring in the coastal area since the late 1980s due to rising seawater temperatures. Of the 19 Sargassum species (31.6%) in drifting algae, we found that six were tropical species, whereas a study in the early 1980s found only one tropical species among 12 species (8.3%), thereby suggesting an increase in the proportion of tropical Sargassum species in drifting algae during the last 30 years. Drifting temperate algae were abundantly present from late winter to summer, whereas tropical algal clumps occurred primarily during summer. In the warm season, fish assemblages did not differ significantly between drifting temperate and tropical algae, suggesting the low host-algal specificity of most fishes. We also found that yellowtail juveniles frequently aggregated with drifting temperate algae from late winter to spring when drifting tropical algae were unavailable. Local fishermen collect these juveniles for use as aquaculture seed stock; therefore, the occurrence of drifting temperate algae in early spring is important for local fisheries. These results suggest that the further extinction of temperate Sargassum spp. may have negative impacts on the pelagic ecosystem and associated regional fisheries.

Yamasaki, Mami; Aono, Mikina; Ogawa, Naoto; Tanaka, Koichiro; Imoto, Zenji; Nakamura, Yohei

2014-06-01

435

Biochemical Basis ofObligate Autotrophy in Blue-Green Algae andThiobacilli  

Microsoft Academic Search

Differential rates ofincorporation ofsugars,organic acids, andaminoacids during autotrophic growth ofseveral blue-green algae andthiobacilli havebeendetermined. Inobligate autotrophs (both blue-green algae andthiobacilli), exogenously fur- nished organic compounds makea verysmallcontribution tocellular carbon; ace- tate, themostreadily incorporated compound ofthose studied, contributes about 10% ofnewlysynthesized cellular carbon. InThiobacillus intermedius, a facultative chemoautotroph, acetate contributes over40%ofnewly synthesized cellular carbon, andsuccinate andglutamate almost 90%.Intheobligate autotrophs, carbon from

ARNOLD J. SMITH; ROGER Y. STANIER

1967-01-01

436

Genome sequence of the ultrasmall unicellular red alga Cyanidioschyzon merolae 10D  

Microsoft Academic Search

Small, compact genomes of ultrasmall unicellular algae provide information on the basic and essential genes that support the lives of photosynthetic eukaryotes, including higher plants. Here we report the 16,520,305-base-pair sequence of the 20 chromosomes of the unicellular red alga Cyanidioschyzon merolae 10D as the first complete algal genome. We identified 5,331 genes in total, of which at least 86.3%

Motomichi Matsuzaki; Osami Misumi; Tadasu Shin-i; Shinichiro Maruyama; Manabu Takahara; Shin-ya Miyagishima; Toshiyuki Mori; Keiji Nishida; Fumi Yagisawa; Keishin Nishida; Yamato Yoshida; Yoshiki Nishimura; Shunsuke Nakao; Tamaki Kobayashi; Yu Momoyama; Tetsuya Higashiyama; Ayumi Minoda; Masako Sano; Hisayo Nomoto; Kazuko Oishi; Hiroko Hayashi; Fumiko Ohta; Satoko Nishizaka; Shinobu Haga; Sachiko Miura; Tomomi Morishita; Yukihiro Kabeya; Kimihiro Terasawa; Yutaka Suzuki; Yasuyuki Ishii; Shuichi Asakawa; Hiroyoshi Takano; Niji Ohta; Haruko Kuroiwa; Kan Tanaka; Nobuyoshi Shimizu; Sumio Sugano; Naoki Sato; Hisayoshi Nozaki; Naotake Ogasawara; Yuji Kohara; Tsuneyoshi Kuroiwa

2004-01-01

437

Characterization of a plasma membrane H + ATPase from the extremely acidophilic alga Dunaliella acidophila  

Microsoft Academic Search

Summary Dunaliella acidophila is an unicellular green alga which grows optimally at pH 0–1 while maintaining neutral internal pH. A plasma membrane preparation of this algae has been purified on sucrose density gradients. The preparation exhibits vanadatesensitive ATPase activity of 2 µmol Pi\\/mg protein\\/min, an activity 15 to 30-fold higher than that in the related neutrophilic speciesD. salina. The following

Israel Sekler; Heinz-Ulrich Gläser; Uri Pick

1991-01-01

438

Microsatellite markers for Dictyochloropsis reticulata (Trebouxiophyceae), the symbiotic alga of the lichen Lobaria pulmonaria (L.)  

Microsoft Academic Search

We isolated and characterized eight microsatellite markers for Dictyochloropsis reticulata, the primary photosynthetic partner of the epiphytic lichen Lobaria pulmonaria. These are the first microsatellite loci reported for a lichen symbiotic alga. These polymorphic markers will be useful for\\u000a investigating spatial genetic structure, biogeography and dispersal of this eukaryotic alga and will generally shed light\\u000a on the coevolution of the

Francesco Dal Grande; Ivo Widmer; Andreas Beck; Christoph Scheidegger

2010-01-01

439

Production of hydrogen from marine macro-algae biomass using anaerobic sewage sludge microflora  

Microsoft Academic Search

Hydrogen was produced from various marine macro-algae (seaweeds) through anaerobic fermentation using an undefined bacterial\\u000a consortium. In this study, anaerobic fermentation from various marine macro-algae for Ulva lactuca, Porphyra tenera, Undaria pinnatifida, and Laminaria japonica was studied. From this analysis Laminaria japorica was determined to be the optimum substrate for hydrogen production. When L. japornica was used as the carbon

Jae-Il Park; Jinwon Lee; Sang Jun Sim; Jae-Hwa Lee

2009-01-01

440

Behavioural and physical effects of arsenic exposure in fish are aggravated by aquatic algae.  

PubMed

Arsenic contamination has global impacts and freshwaters are major arsenic repositories. Arsenic toxicity depends on numerous interacting factors which makes effects difficult to estimate. The use of aquatic algae is often advocated for bioremediation of arsenic contaminated waters as they absorb arsenate and transform it into arsenite and methylated chemical species. Fish are another key constituent of aquatic ecosystems. Contamination in natural systems is often too low to cause mortality but sufficient to interfere with normal functioning. Alteration of complex, naturally occurring fish behaviours such as foraging and aggression are ecologically relevant indicators of toxicity and ideal for assessing sublethal impacts. We examined the effects of arsenic exposure in the invasive mosquitofish, Gambusia holbrooki, in a laboratory experiment incorporating some of the complexity of natural systems by including the interacting effects of aquatic algae. Our aims were to quantify the effects of arsenic on some complex behaviours and physical parameters in mosquitofish, and to assess whether the detoxifying mechanisms of algae would ameliorate any effects of arsenic exposure. Aggression increased significantly with arsenic whereas operculum movement decreased non-significantly and neither food capture efficiency nor consumption were notably affected. Bioaccumulation increased with arsenic and unexpectedly so did fish biomass. Possibly increased aggression facilitated food resource defence allowing fish to gain weight. The presence of algae aggravated the effects of arsenic exposure. For increase in fish biomass, algae acted antagonistically with arsenic, resulting in a disadvantageous reduction in weight gained. For bioaccumulation the effects were even more severe, as algae operated additively with arsenic to increase arsenic uptake and/or assimilation. Aggression was also highest in the presence of both algae and arsenic. Bioremediation of arsenic contaminated waters using aquatic algae should therefore be carried out with consideration of entire ecosystem effects. We highlight that multidisciplinary, cross-taxon research, particularly integrating behavioural and other effects, is crucial for understanding the impacts of arsenic toxicity and thus restoration of aquatic ecosystems. PMID:25190483

Magellan, Kit; Barral-Fraga, Laura; Rovira, Marona; Srean, Pao; Urrea, Gemma; García-Berthou, Emili; Guasch, Helena

2014-11-01

441

Polysaccharides and sterols from green algae Caulerpa lentillifera and C. sertularioides  

Microsoft Academic Search

Sterols and polysaccharides of green alga Caulerpa lentillifera grown under laboratory conditions and in mariculture and polysaccharides of green alga C. sertularioides grown under natural conditions were studied. The sterol fraction consisted of C27-C29 steroidal alcohols with ?5-unsaturation in the steroid core regardless of the growth conditions. The dominant (79.9%) steroid component of the sterol\\u000a fraction was clionasterol. The water-soluble

N. M. Shevchenko; Yu. V. Burtseva; T. N. Zvyagintseva; O. S. Sergeeva; A. M. Zakharenko; V. V. Isakov; Nguyen Thi Linh; Nguyen Xuan Hoa; Bui Minh Ly; Pham Van Huyen

2009-01-01

442

A comparative study on heavy metal biosorption characteristics of some algae  

Microsoft Academic Search

The biosorption of copper(II), nickel(II) and chromium(VI) from aqueous solutions on dried (Chlorella vulgaris, Scenedesmus obliquus and Synechocystis sp.) algae were tested under laboratory conditions as a function of pH, initial metal ion and biomass concentrations. Optimum adsorption pH values of copper(II), nickel(II) and chromium(VI) were determined as 5.0, 4.5 and 2.0. respectively, for all three algae. At the optimal

G Çetinkaya Dönmez; Z Aksu; A Öztürk; T Kutsal

1999-01-01

443

The growth and harvesting of algae in a micro-gravity environment  

NASA Technical Reports Server (NTRS)

Algae growth in a micro-gravity environment is an important factor in supporting man's permanent presence in space. Algae can be used to produce food, oxygen, and pure water in a manned space station. A space station is one example of a situation where a Controlled Ecological Life Support System (CELSS) is imperative. In setting up a CELSS with an engineering approach at the Aerospace department of the University of Colorado, questions concerning algae growth in micro-g have arisen. The Get Away Special (GAS) Fluids Management project is a means through which many questions about the effects of a micro-g environment on the adequacy of growth rates, the viability of micro-organisms, and separation of gases and solids for harvesting purposes can be answered. In order to be compatible with the GAS tests, the algae must satisfy the following criteria: (1) rapid growth rates, (2) sustain viability over long periods of non-growth storage, and (3) very brief latency from storage to rapid growth. Testing indicates that the overall growth characteristics of Anacystis Nidulans satisfy the specifications of GAS's design constraints. In addition, data acquisition and the method of growth instigation are two specific problems being examined, as they will be encountered in interfacing with the GAS project. Flight testing will be two-fold, measurement of algae growth in micro-g and separation of algae from growth medium in an artificial gravitation field. Post flight results will provide information on algae viability in a micro-g environment as reflected by algal growth rates in space. Other post flight results will provide a basis for evaluating techniques for harvesting algae. The results from the GAS project will greatly assist the continuing effort of developing the CELSS and its applications for space.

Wiltberger, Nancy L.

1987-01-01

444

Evaluation of the contamination of marine algae (seaweed) from the St. Lawrence River and likely to be consumed by humans  

SciTech Connect

The goal of the study was to assess the contamination of marine algae (seaweeds) growing in the St. Lawrence River estuary and Gulf of St. Lawrence and to evaluate the risks to human health from the consumption of these algae. Algae were collected by hand at low tide. A total of 10 sites on the north and south shores of the St. Lawrence as well as in Baie des Chaleurs were sampled. The most frequently collected species of algae were Fucus vesiculosus, Ascophyllum nodosum, Laminaria Longicruris, Palmaria palmata, Ulva lactuca, and Fucus distichus. Alga samples were analyzed for metals iodine, and organochlorines. A risk assessment was performed using risk factors. In general, concentrations in St. Lawrence algae were not very high. Consequently, health risks associated with these compounds in St. Lawrence algae were very low. Iodine concentration, on the other hand, could be of concern with regard to human health. Regular consumption of algae, especially of Laminaria sp., could result in levels of iodine sufficient to cause thyroid problems. For regular consumers, it would be preferable to choose species with low iodine concentrations, such as U. lactuca and P. palmata, in order to prevent potential problems. Furthermore, it would also be important to assess whether preparation for consumption or cooking affects the iodine content of algae. Algae consumption may also have beneficial health effects. Scientific literature has shown that it is a good source of fiber and vitamins, especially vitamin B{sub 12}.

Phaneuf, D.; Cote, I.; Dumas, P.; Ferron, L.A.; LeBlanc, A. [CHUQ, Sainte-Foy, Quebec (Canada). Centre de Toxicologie du Quebec] [CHUQ, Sainte-Foy, Quebec (Canada). Centre de Toxicologie du Quebec

1999-02-01

445

Assessing the energy and environmental performance of algae-mediated tertiary treatment of estrogenic compounds.  

PubMed

This study uses a systems-level modeling approach to illustrate a novel synergy between municipal wastewater treatment and large-scale algaculture for production of bio-energy, whereby algae-mediated tertiary treatment provides efficient removal of unregulated, strongly estrogenic steroid hormones from the secondary effluent. Laboratory results from previously published studies suggested that algae-mediated treatment could deliver roughly 75-85% removal of a model estrogen (17?-estradiol) within typical algae pond residence times. As such, experimental results are integrated into a comprehensive life cycle assessment (LCA) framework, to assess the environmental performance of an algae-based tertiary treatment system relative to three conventional tertiary treatments: ozonation, UV irradiation, and adsorption onto granular activated carbon. Results indicate that the algae-mediated tertiary treatment is superior to the selected benchmarks on the basis of raw energy return on investment (EROI) and normalized energy use per mass of estrogenic toxicity removed. It is the only tertiary treatment system that creates more energy than it consumes, and it delivers acceptable effluent quality for nutrient and coliform concentrations while rendering a significant reduction in estrogenic toxicity. These results highlight the dual water and energy sustainability benefits that accrue from the integration of municipal wastewater treatment and large-scale algae farming. PMID:25537081

Colosi, Lisa M; Resurreccion, Eleazer P; Zhang, Yongli

2015-02-11

446

The blue water footprint and land use of biofuels from algae  

NASA Astrophysics Data System (ADS)

from microalgae are potentially important sources of liquid renewable energy. Algae are not yet produced on a large scale, but research shows promising results. This study assesses the blue water footprint (WF) and land use of algae-based biofuels. It combines the WF concept with an energy balance approach to determine the blue WF of net energy. The study considers open ponds and closed photobioreactors (PBRs). All systems have a positive energy balance, with output-input ratios ranging between 1.13 and 1.98. This study shows that the WF of algae-based biofuels lies between 8 and 193 m3/GJ net energy provided. The land use of microalgal biofuels ranges from 20 to 200 m2/GJ net energy. For a scenario in which algae-based biofuels provide 3.5% of the transportation fuels in the European Union in 2030, the system with the highest land productivity needs 17,000 km2 to produce the 850 PJ/yr. Producing all algae-based biofuels through the system with the highest water productivity would lead to a blue WF of 7 Gm3/yr, which is equivalent to 15% of the present blue WF in the EU28. A transition to algae-based transportation fuels will substantially increase competition over water and land resources.

Gerbens-Leenes, P. W.; Xu, L.; Vries, G. J.; Hoekstra, A. Y.

2014-11-01

447

Production of the blood pressure lowing peptides from brown alga ( Undaria pinnatifida)  

NASA Astrophysics Data System (ADS)

Brown alga ( Undaria pinnatifida) was treated with alginate lyase and hydrolyzed using 17 kinds of proteases and the inhibitory activity of the hydrolysates for the angiotensin-I-converting enzyme (ACE) was measured. Four hydrolysates with potent ACE-inhibitory activity were administered singly and orally to spontaneously hypertensive rats (SHRs). The systolic blood pressure of SHRs decreases significantly after single oral administration of the brown alga hydrolysates by protease S ‘Amano’ (from Bacillus stearothermophilus) at the concentration of 10 (mg protein) (kg body weight)-1. In the 17 weeks of feeding experiment, 7-week-old SHRs were fed standard diet supplemented with the brown alga hydrolysates for 10 weeks. In SHRs fed 1.0 and 0.1% brown alga hydrolysates, elevating of systolic bloodpressure was significantly suppressed for 7 weeks. To elucidate the active components, the brown alga hydrolysates were fractionated by 1-butanol extraction and HPLC on a reverse-phase column. Seven kinds of ACE-inhibitory peptides were isolated and identified by amino acid composition analysis, sequence analysis, and LC-MS with the results Val-Tyr, Ile-Tyr, Ala-Trp, Phe-Tyr, Val-Trp, Ile-Trp, and Leu-Trp. Each peptide was determined to have an antihypertensive effect after a single oral administration in SHRs. The brown alga hydrolysates were also confirmed to decrease the blood pressure in humans.

Minoru, Sato; Takashi, Oba; Takao, Hosokawa; Toshiyasu, Yamaguchi; Toshiki, Nakano; Tadao, Saito; Koji, Muramoto; Takashi, Kahara; Katsura, Funayama; Akio, Kobayashi; Takahisa, Nakano

2005-07-01

448

The Suez Canal as a habitat and pathway for marine algae and seagrasses  

NASA Astrophysics Data System (ADS)

The Suez Canal supports a diversified benthic algal flora; 133 species of benthic algae are now known from the Canal, as compared with only 24 in 1924. The vertical and horizontal distribution of algae is considered in relation to hydrographic factors. The algae display zonation and 3-4 algal belts are distinguished on the Canal banks on buoys and pier supports. Associated fauna include Balanus amphitrite and Brachidontes variabilis, together with various hydroids, sponges, ascidians, asteroids, ophiuroids and crustaceans. Merceriella enigmatica thrives well in brackish water habitats. The algal flora in the Bitter Lakes resembles that in the Red Sea. The number of Red Sea species decreases from Suez to Port Said in the littoral zone. On the other hand, bottom algae predominantly belong to Red Sea flora. Thirty of the species of algae found belong to the Indo-Pacific flora; half of these are new records to the Canal. Several of these Indo-Pacific algae have recently become established in the Eastern Mediterranean, whereas only two of the Mediterranean macro-algal flora (viz. Caulerpa prolifera and Halopteris scoparia) have been found in the Gulf of Suez. Two seagrasses, Halopia ovalis and Thalassia hemprichii, are recorded for the first time in the Canal. Only Halophila stipulacea has found its way into the Mediterranean via the Suez Canal, but none of the Mediterranean seagrasses is found either in the Canal or in the Red Sea.

Aleem, A. A.

449

Sorption of copper(II) ions in the biomass of alga Spirogyra sp.  

PubMed

Sorption of copper ions by the alga Spirogyra sp. was investigated to determine the influence of experimental conditions and the methods of sample preparation on the process. The experiments were carried out both under the static and the dynamic conditions. Kinetics and equilibrium parameters of the sorption were evaluated. In addition, the influence was studied of the algae preparation methods on the conductivity of demineralized water in which the algae samples were immersed. The static experiments showed that the sorption of Cu(2+) ions reached equilibrium in about 30 min, with approximately 90% of the ions adsorbed in the initial 15 min. The sorption capacity determined from the Langmuir isotherms appeared highly uncertain (SD=±0.027 mg/g dry mass or ±11%, for the live algae). Under static conditions, the slopes of the Langmuir isotherms depended on the ratio of the alga mass to the volume of solution. The conductometric measurements were proven to be a simple and fast way to evaluate the quality of algae used for the experiments. PMID:22245248

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

2012-10-01

450

Enhancement of Taihu blue algae anaerobic digestion efficiency by natural storage.  

PubMed

Taihu blue algae after different storage time from 0 to 60 d were anaerobic fermented to evaluate their digestibility and process stability. Results showed that anaerobic digestion (AD) of blue algae under 15 d natural storage led to the highest CH4 production of 287.6 mL g(-1) VS at inoculum substrate ratio 2.0, demonstrating 36.69% improvement comparing with that from fresh algae. Storage of blue algae led to cell death, microcystins (MCs) release and VS reduction by spontaneous fermentation. However, it also played an important role in removing algal cell wall barrier, pre-hydrolysis and pre-acidification, leading to the improvement in CH4 yield. Closer examination of volatile fatty acids (VFA) variation, VS removal rates and key enzymes change during AD proved short storage time (? 15 d) of blue algae had higher efficiencies in biodegradation and methanation. Furthermore, AD presented significant biodegradation potential for MCs released from Taihu blue algae. PMID:24128398

Miao, Hengfeng; Lu, Minfeng; Zhao, Mingxing; Huang, Zhenxing; Ren, Hongyan; Yan, Qun; Ruan, Wenquan

2013-12-01

451

The Cell Walls of Green Algae: A Journey through Evolution and Diversity  

PubMed Central

The green algae represent a large group of morphologically diverse photosynthetic eukaryotes that occupy virtually every photic habitat on the planet. The extracellular coverings of green algae including cell walls are also diverse. A recent surge of research in green algal cell walls fueled by new emerging technologies has revealed new and critical insight concerning these coverings. For example, the late divergent taxa of the Charophycean green algae possess cell walls containing assemblages of polymers with notable similarity to the cellulose, pectins, hemicelluloses, arabinogalactan proteins (AGPs), extensin, and lignin present in embryophyte walls. Ulvophycean seaweeds have cell wall components whose most abundant fibrillar constituents may change from cellulose to ?-mannans to ?-xylans and during different life cycle phases. Likewise, these algae produce complex sulfated polysaccharides, AGPs, and extensin. Chlorophycean green algae produce a wide array of walls ranging from cellulose–pectin complexes to ones made of hydroxyproline-rich glycoproteins. Larger and more detailed surveys of the green algal taxa including incorporation of emerging genomic and transcriptomic data are required in order to more fully resolve evolutionary trends within the green algae and in relationship with higher plants as well as potential applications of wall components in the food and pharmaceutical industries. PMID:22639667

Domozych, David S.; Ciancia, Marina; Fangel, Jonatan U.; Mikkelsen, Maria Dalgaard; Ulvskov, Peter; Willats, William G. T.

2012-01-01

452

Microcontact imprinting of algae on poly(ethylene-co-vinyl alcohol) for biofuel cells.  

PubMed

Hydrogen can be produced using microorganisms (e.g., bacteria and algae); algal production has the additional ecological benefit of carbon dioxide fixation. The conversion of hydrogen to electricity via fuel cells may be more efficient compared to other energy sources of electricity. However, the anode of biofuel cells requires the immobilization of microorganisms or enzymes. In this work, poly(ethylene-co-vinyl alcohol) (EVAL), was coated on the electrode, and green algae was microcontact imprinted onto the EVAL film. The readsorption of algae onto algae-imprinted EVAL thin films was compared to determine the ethylene content that gave highest imprinting effectiveness and algal binding. Scanning electron microscopy and fluorescence spectrometry were employed to characterize the surface morphology, recognition capacity, and reusability of the algae-imprinted cavities. The recognition of an individual algal cell by binding to the imprinted cavities was directly observed by video microscopy. Finally, the power and current density of the algal biofuel cell using the algae-imprinted EVAL-coated electrode were measured at about 2-fold higher than electrode sputtered platinum on poly(ethylene terephthalate). PMID:24095224

Chen, Wen-Janq; Lee, Mei-Hwa; Thomas, James L; Lu, Po-Hsun; Li, Ming-Huan; Lin, Hung-Yin

2013-11-13

453

Enhanced electricity generation by using algae biomass and activated sludge in microbial fuel cell.  

PubMed

Recently, interest is growing to explore low-cost and sustainable means of energy production. In this study, we have exploited the potential of sustainable energy production from wastes. Activated sludge and algae biomass are used as substrates in microbial fuel cell (MFC) to produce electricity. Activated sludge is used at anode as inoculum and nutrient source. Various concentrations (1-5 g/L) of dry algae biomass are tested. Among tested concentrations, 5 g/L (5000 mg COD/L) produced the highest voltage of 0.89 V and power density of 1.78 W/m(2) under 1000 ? electric resistance. Pre-treated algae biomass and activated sludge are also used at anode. They give low power output than without pre-treatment. Spent algae biomass is tested to replace whole (before oil extraction) algae biomass as a substrate, but it gives low power output. This work has proved the concept of using algae biomass in MFC for high energy output. PMID:23584037

Rashid, Naim; Cui, Yu-Feng; Saif Ur Rehman, Muhammad; Han, Jong-In

2013-07-01

454

The impact of supplementing lambs with algae on growth, meat traits and oxidative status.  

PubMed

The current study examined the effect of supplementing lambs with algae. Forty, three month old lambs were allocated to receive a control ration based on oats and lupins (n=20) or the control ration with DHA-Gold™ algae (~2% of the ration, n=20). These lambs came from dams previously fed a ration based on either silage (high in omega-3) or oats and cottonseed meal (OCSM: high in omega-6) at joining (dam nutrition, DN). Lamb performance, carcase weight and GR fat content were not affected by treatment diet (control vs algae) or DN (silage vs OSCM). Health claimable omega-3 fatty acids (EPA+DHA) were significantly greater in the LL of lambs fed algae (125±6mg/100g meat) compared to those not fed algae (43±6mg/100g meat) and this effect was mediated by DN. Supplementing with algae high in DHA provides a means of improving an aspect of the health status of lamb meat. PMID:24950082

Hopkins, D L; Clayton, E H; Lamb, T A; van de Ven, R J; Refshauge, G; Kerr, M J; Bailes, K; Lewandowski, P; Ponnampalam, E N

2014-10-01

455

Use of the beta-carotene rich alga Dunaliella bardawil as a source of retinol.  

PubMed

Dunaliella bardawil, a beta-carotene accumulating halotolerant alga, has been tested as a source of retinol in a chick diet. Chicks were fed diets deficient in retinol or supplemented with retinol, synthetic beta-carotene or dry algae. After an initial lag, chicks grew equally well on diets supplemented with algae, retinol or beta-carotene. Serum and liver analyses revealed a normal content of retinol in all chicks except those grown on the retinol-deficient diet. Chicks fed the algae-supplemented diet contained lutein but no beta-carotene in their serum, even though the ratio of beta-carotene to lutein in the algae was over 15:1. Laying hens fed with an algae-supplemented diet showed enhanced egg yolk colour attributable to a higher lutein content. No beta-carotene was present in the egg-yolk. These studies demonstrate the possibility of using dried Dunaliella bardawil as a dietary supplement which can fully satisfy the retinol requirement and also serve as a yolk-colour enhancing agent. PMID:3815129

Ben-Amotz, A; Edelstein, S; Avron, M

1986-12-01

456

Algae biodiesel life cycle assessment using current commercial data.  

PubMed

Autotrophic microalgae represent a potential feedstock for transportation fuels, but life cycle assessment (LCA) studies based on laboratory-scale or theoretical data have shown mixed results. We attempt to bridge the gap between laboratory-scale and larger scale biodiesel production by using cultivation and harvesting data from a commercial algae producer with ?1000 m(2) production area (the base case), and compare that with a hypothetical scaled up facility of 101,000 m(2) (the future case). Extraction and separation data are from Solution Recovery Services, Inc. Conversion and combustion data are from the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation Model (GREET). The LCA boundaries are defined as "pond-to-wheels". Environmental impacts are quantified as NER (energy in/energy out), global warming potential, photochemical oxidation potential, water depletion, particulate matter, and total NOx and SOx. The functional unit is 1 MJ of energy produced in a passenger car. Results for the base case and the future case show an NER of 33.4 and 1.37, respectively and GWP of 2.9 and 0.18 kg CO2-equivalent, respectively. In comparison, petroleum diesel and soy diesel show an NER of 0.18 and 0.80, respectively and GWP of 0.12 and 0.025, respectively. A critical feature in this work is the low algal productivity (3 g/m(2)/day) reported by the commercial producer, relative to the much higher productivities (20-30 g/m(2)/day) reported by other sources. Notable results include a sensitivity analysis showing that algae with an oil yield of 0.75 kg oil/kg dry biomass in the future case can bring the NER down to 0.64, more comparable with petroleum diesel and soy biodiesel. An important assumption in this work is that all processes are fully co-located and that no transport of intermediate or final products from processing stage to stage is required. PMID:23900083

Passell, Howard; Dhaliwal, Harnoor; Reno, Marissa; Wu, Ben; Ben Amotz, Ami; Ivry, Etai; Gay, Marcus; Czartoski, Tom; Laurin, Lise; Ayer, Nathan

2013-11-15

457

Gain and loss of elongation factor genes in green algae  

PubMed Central

Background Two key genes of the translational apparatus, elongation factor-1 alpha (EF-1?) and elongation factor-like (EFL) have an almost mutually exclusive distribution in eukaryotes. In the green plant lineage, the Chlorophyta encode EFL except Acetabularia where EF-1? is found, and the Streptophyta possess EF-1? except Mesostigma, which has EFL. These results raise questions about evolutionary patterns of gain and loss of EF-1? and EFL. A previous study launched the hypothesis that EF-1? was the primitive state and that EFL was gained once in the ancestor of the green plants, followed by differential loss of EF-1? or EFL in the principal clades of the Viridiplantae. In order to gain more insight in the distribution of EF-1? and EFL in green plants and test this hypothesis we screened the presence of the genes in a large sample of green algae and analyzed their gain-loss dynamics in a maximum likelihood framework using continuous-time Markov models. Results Within the Chlorophyta, EF-1? is shown to be present in three ulvophycean orders (i.e., Dasycladales, Bryopsidales, Siphonocladales) and the genus Ignatius. Models describing gene gain-loss dynamics revealed that the presence of EF-1?, EFL or both genes along the backbone of the green plant phylogeny is highly uncertain due to sensitivity to branch lengths and lack of prior knowledge about ancestral states or rates of gene gain and loss. Model refinements based on insights gained from the EF-1? phylogeny reduce uncertainty but still imply several equally likely possibilities: a primitive EF-1? state with multiple independent EFL gains or coexistence of both genes in the ancestor of the Viridiplantae or Chlorophyta followed by differential loss of one or the other gene in the various lineages. Conclusion EF-1? is much more common among green algae than previously thought. The mutually exclusive distribution of EF-1? and EFL is confirmed in a large sample of green plants. Hypotheses about the gain-loss dynamics of elongation factor genes are hard to test analytically due to a relatively flat likelihood surface, even if prior knowledge is incorporated. Phylogenetic analysis of EFL genes indicates misinterpretations in the recent literature due to uncertainty regarding the root position. PMID:19216746

Cocquyt, Ellen; Verbruggen, Heroen; Leliaert, Frederik; Zechman, Frederick W; Sabbe, Koen; De Clerck, Olivier

2009-01-01

458

Fucoidan from Marine Brown Algae Inhibits Lipid Accumulation  

PubMed Central

In this study, we elucidated the inhibitory effect of fucoidan from marine brown algae on the lipid accumulation in differentiated 3T3-L1 adipocytes and its mechanism. The treatment of fucoidan in a dose-dependent manner was examined on lipid inhibition in 3T3-L1 cells by using Oil Red O staining. Fucoidan showed high lipid inhibition activity at 200 ?g/mL concentration (P < 0.001). Lipolytic activity in adipocytes is highly dependent on hormone sensitive lipase (HSL), which is one of the most important targets of lipolytic regulation. Here, we examined the biological response of fucoidan on the protein level of lipolysis pathway. The expressed protein levels of total hormone sensitive lipase (HSL) and its activated form, phosphorylated-HSL were significantly increased at concentration of 200 ?g/mL fucoidan. Furthermore, insulin-induced 2-deoxy-d-[3H] glucose uptake was decreased up to 51% in fucoidan-treated cells as compared to control. Since increase of HSL and p-HSL expression and decrease of glucose uptake into adipocytes are known to lead to stimulation of lipolysis, our results suggest that fucoidan reduces lipid accumulation by stimulating lipolysis. Therefore, these results suggest that fucoidan can be useful for the prevention or treatment of obesity due to its stimulatory lipolysis. PMID:21892350

Park, Min-Kyoung; Jung, Uhee; Roh, Changhyun

2011-01-01

459

Thermogravimetric characteristics and pyrolysis kinetics of alga Sagarssum sp. biomass.  

PubMed

Alga Sagarssum sp. can be converted to bio-oil, gas, and char through pyrolysis. In this study, the pyrolysis characteristics and kinetics of Sagarssum sp. were investigated using a thermogravimetric analyzer and tubing reactor, respectively. Sagarssum sp. decomposed below 550°C, but the majority of materials decomposed between 200 and 350°C at heating rates of 5-20°C/min. The apparent activation energy increased from 183.53 to 505.57 kJ mol(-1) with increasing pyrolysis conversion. The kinetic parameters of Sagarssum sp. pyrolysis were determined using nonlinear least-squares regression of the experimental data, assuming second-order kinetics. The proposed lumped kinetic model represented the experimental results well and the kinetic rate constants suggested a predominant pyrolysis reaction pathway from Sagarssum sp. to bio-oil, rather than from Sagarssum sp. to gas. The kinetic rate constants indicated that the predominant reaction pathway was A (Sagarssum sp.) to B (bio-oil), rather than A (Sagarssum sp.) to C (gas; C1-C4). PMID:23665684

Kim, Seung-Soo; Ly, Hoang Vu; Kim, Jinsoo; Choi, Jae Hyung; Woo, Hee Chul

2013-07-01

460

Production of carbonate sediments by a unicellular green alga  

USGS Publications Warehouse

This study investigates the ability of the unicellular green alga Natmochloris atoimis to precipitate CaCO3, quantifies mineral precipitation rates, estimates sediment production in a N. atomiis 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 parameters for calcification. Rates of calcification were calculated from initial and postincubation alkalinity, pH, and calcium measurements. Replicate experiments and controls consisting of non-calcifying cultures, uninoculated media, and dead cell cultures were performed using environmental culture parameters determined in series cultures. Average calcification rates from replicate experiments were used to predict daily sediment production rates in a small bloom of N. atomus. N. atomus precipitates 0.138 g/L of calcite in approximately 4 h when incubated at pH 8.5, 14.24 mM calcium concentration, 33 ??C, 100 ??E/m2/s light intensity, and a cell population density of 107 cells/mL. Assuming continuous precipitation, this corresponds to a maximum estimated sediment production rate of 1.6 ?? 106 kg of CaCO3, per 12 h day in a single bloom of 3.2 ?? 109 L. Our results suggest that microbial calcification contributes significantly to the carbonate sediment budget.

Yates, K.K.; Robbins, L.L.

1998-01-01

461

Triassic origin and early radiation of multicellular volvocine algae  

PubMed Central

Evolutionary transitions in individuality (ETIs) underlie the watershed 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 in the level of complexity, as groups of individuals become individuals in their own right. Among the best-studied ETIs is the origin of multicellularity in the green alga Volvox, a model system for the evolution of multicellularity and cellular differentiation. Since its divergence from unicellular ancestors, Volvox has evolved into a highly integrated multicellular organism with cellular specialization, a complex developmental program, and a high degree of coordination among cells. Remarkably, all of these changes were previously thought to have occurred in the last 50–75 million years. Here we estimate divergence times using a multigene data set with multiple fossil calibrations and use these estimates to infer the times of developmental changes relevant to the evolution of multicellularity. Our results show that Volvox diverged from unicellular ancestors at least 200 million years ago. Two key innovations resulting from an early cycle of cooperation, conflict and conflict mediation led to a rapid integration and radiation of multicellular forms in this group. This is the only ETI for which a detailed timeline has been established, but multilevel selection theory predicts that similar changes must have occurred during other ETIs. PMID:19223580

Herron, Matthew D.; Hackett, Jeremiah D.; Aylward, Frank O.; Michod, Richard E.

2009-01-01

462

COMPLEMENTARY CHROMATIC ADAPTATION IN A FILAMENTOUS BLUE-GREEN ALGA  

PubMed Central

Fluorescent and red light environments generate greatly different patterns of pigmentation and morphology in Fremyella diplosiphon. Most strikingly, red-illuminated cultures contain no measurable C-phycoerythrin and have a mean filament length about 10 times shorter than fluorescent-illuminated cultures. C-phycoerythrin behaves as a photoinducible constituent of this alga. Spectrophotometric and immunochemical procedures were devised so that C-phycoerythrin metabolism could be studied quantitatively with [14C]-phenylalanine pulse-chased cultures. Transfer of red-illuminated cultures to fluorescent light initiates C-phycoerythrin production by essentially de novo synthesis. C-phycoerythrin is not degraded to any significant extent in cultures continuously illuminated with fluorescent light. Transfer of fluorescent-illuminated cultures to red light causes an abrupt cessation of C-phycoerythrin synthesis. The C-phycoerythrin content of cultures adapting to red light decreases and subsequently becomes constant. Loss of C-phycoerythrin is not brought about by metabolic degradation, but rather by a decrease in mean filament length which is effected by transcellular breakage. In this experimental system, light influences intracellular C-phycoerythrin levels by regulating the rate of synthesis of the chromoprotein. PMID:4199659

Bennett, Allen; Bogorad, Lawrence

1973-01-01

463

Biosorption of cadmium by biomass of marine algae.  

PubMed

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 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(2+)/g (at the residual concentration of 100 mg Cd/L and pH 3.5), outperforming a commercial ion exchange resin DUOLITE GT-73. A new biosorbent material based on A. nodosum biomass was obtained by reinforcing the algal biomass by formaldehyde cross-linking. The prepared sorbent possessed good mechanical properties, chemical stability of the cell wall polysaccharides and low swelling volume. Desorption of deposited cadmium with 0.1-0.5M HCI resulted in no changes of the biosorbent metal uptake capacity through five subsequent adsorption/desorption cycles. There was no damage to the biosorbent which retained its macroscopic appearance and performance in repeated metal uptake/elution cycles. PMID:18609626

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

1993-04-01

464

Ribulose bisphosphate carboxylase in algae: synthesis, enzymology and evolution.  

PubMed

Studies demonstrating differences in chloroplast structure and biochemistry have been used to formulate hypotheses concerning the origin of algal plastids. Genetic and biochemical experiments indicate that significant variation occurs in ribulose-1,5-bisphosphate carboxylase (Rubisco) when supertaxa of eukaryotic algae are compared. These differences include variations in the organelle location of the genes and their arrangement, mechanism of Rubisco synthesis, polypeptide immunological reactivity and sequence, as well as efficacy of substrate (ribulose bisphosphate and CO2) binding and inhibitor (6-phosphogluconate) action. The structure-function relationships observed among chromophytic, rhodophytic, chlorophytic and prokaryotic Rubisco demonstrate that: (a) similarities among chromophytic and rhodophytic Rubisco exist in substrate/inhibitor binding and polypeptide sequence, (b) characteristic differences in enzyme kinetics and subunit polypeptide structure occur among chlorophytes, prokaryotes and chromophytes/rhodophytes, and (c) there is structural variability among chlorophytic plant small subunit polypeptides, in contrast to the conservation of this polypeptide in chromophytes and rhodophytes. Taxa-specific differences among algal Rubisco enzymes most likely reflect the evolutionary history of the plastid, the functional requirements of each polypeptide, and the consequences of encoding the large and small subunit genes in the same or different organelles. PMID:24420459

Newman, S M; Cattolico, R A

1990-11-01

465

Niche of harmful alga Aureococcus anophagefferens revealed through ecogenomics  

SciTech Connect

Harmful algal blooms (HABs) cause significant economic and ecological damage worldwide. Despite considerable efforts, a comprehensive understanding of the factors that promote these blooms has been lacking, because the biochemical pathways that facilitate their dominance relative to other phytoplankton within specific environments have not been identified. Here, biogeochemical measurements showed that the harmful alga Aureococcus anophagefferens outcompeted co-occurring phytoplankton in estuaries with elevated levels of dissolved organic matter and turbidity and low levels of dissolved inorganic nitrogen. We subsequently sequenced the genome of A. anophagefferens and compared its gene complement with those of six competing phytoplankton species identified through metaproteomics. Using an ecogenomic approach, we specifically focused on gene sets that may facilitate dominance within the environmental conditions present during blooms. A. anophagefferens possesses a larger genome (56 Mbp) and has more genes involved in light harvesting, organic carbon and nitrogen use, and encoding selenium- and metal-requiring enzymes than competing phytoplankton. Genes for the synthesis of microbial deterrents likely permit the proliferation of this species, with reduced mortality losses during blooms. Collectively, these findings suggest that anthropogenic activities resulting in elevated levels of turbidity, organic matter, and metals have opened a niche within coastal ecosystems that ideally suits the unique genetic capacity of A. anophagefferens and thus, has facilitated the proliferation of this and potentially other HABs.

Gobler, Christopher J. [Stony Brook University (SUNY); Berry, Dianna L. [Stony Brook University (SUNY); Dyhrman, Sonya T. [Woods Hole Oceanographic Institution (WHOI), Woods Hole, MA; Wilhelm, Steven W [ORNL; Salamov, Asaf [U.S. Department of Energy, Joint Genome Institute; Lobanov, Alexei V. [Brigham and Women's Hospital; Zhang, Yan [Brigham and Women's Hospital; Collier, Jackie L. [Stony Brook University (SUNY); Wurch, Louie L. [Woods Hole Oceanographic Institution (WHOI), Woods Hole, MA; Kustka, Adam B. [Rutgers University; Dill, Brian [ORNL; Shah, Manesh B [ORNL; Verberkmoes, Nathan C [ORNL

2011-01-01

466

An improved method for karyotype analyses of marine algae  

NASA Astrophysics Data System (ADS)

Modified carbol fuchsin staining method was successfully introduced into the karyotype analyses of marine algae, including Porphyra, Undaria pinnatifida and Laminaria japonica. Haploid chromosomes were numbered clearly in the vegetative, spermatangial and conchosporangial cells of P. haitanensis and P. yezoensis. Diploid chromosomes were observed and numbered in immature conchosporangial cells of P. haitanensis and P. yezoensis. Pit-connections of Porphyra were also clearly demonstrated. Prophase chromosomes of conchocelis cells were also clearly stained with modified carbol fuchsin. One molar per liter hydrochloric hydrolysis at 60°C for 7-8 min is necessary for getting transparent cytoplasm for conchosporangial karyotype analysis of Porphyra. Staining effects of the three methods using iron alum acetocarmine, aceto-iron-haematoxylin-chloral hydrate and modified carbol fuchsin were compared on the vegetative, spermatangial and conchosporangial cells of Porphyra and the gametophytes of U. pinnatifida and L. japonica. Among the three methods, the modified carbol fuchsin method gave the best result of deep staining and good contrast between nucleus and cytoplasm.

Wang, Juan; Dai, Jixun

2008-05-01

467

Two natural products from the algae Laurencia scoparia.  

PubMed

The structures and absolute stereochemistries of two chamigrene-type metabolites (spiro[5.5]undecane derivatives) isolated from the red algae Laurencia scoparia are described. One, a non-sesquiterpene named ma?lione (8-bromo-9-hydroxy-7,7-dimethyl-11-methylenespiro[5.5]undec-1-en-3-one), C(14)H(19)BrO(2), was detected previously in Laurencia cartilaginea, while the other, the sesquiterpene isorigidol (8-bromo-3,7,7-trimethyl-11-methylenespiro[5.5]-undec-1-ene-3,9-diol), C(15)H(23)BrO(2), is a new isomer of rigidol, first isolated from Laurencia rigida. The A rings of these spirocyclic compounds show the same carbon skeleton. However, the relative stereochemistry of the 8-Br and 9-OH substituents is different. While ma?lione displays the usual syn (or cis) relative stereochemistry of the bromohydroxy vicinal group, isorigidol shows an anti (or trans) arrangement. The 8-Br and 9-OH groups are both in equatorial positions in isorigidol, while the 9-OH group is axial in ma?lione, as in most chamigrenes. The absolute configurations of the chiral centers were determined as 6S, 8S and 9R in ma?lione, and 3R, 6S, 8S and 9S in isorigidol. PMID:11250580

Suescun, L; Mombrú, A W; Mariezcurrena, R A; Davyt, D; Fernández, R; Manta, E

2001-03-01

468

Niche of harmful alga Aureococcus anophagefferens revealed through ecogenomics  

SciTech Connect

Harmful algal blooms (HABs) cause significant economic and ecological damage worldwide. Despite considerable efforts, a comprehensive understanding of the factors that promote these blooms has been lacking, because the biochemical pathways that facilitate their dominance relative to other phytoplankton within specific environments have not been identified. Here, biogeochemical measurements showed that the harmful alga Aureococcus anophagefferens outcompeted co-occurring phytoplankton in estuaries with elevated levels of dissolved organic matter and turbidity and low levels of dissolved inorganic nitrogen. We subsequently sequenced the genome of A. anophagefferens and compared its gene complement with those of six competing phytoplankton species identified through metaproteomics. Using an ecogenomic approach, we specifically focused on gene sets that may facilitate dominance within the environmental conditions present during blooms. A. anophagefferens possesses a larger genome (56 Mbp) and has more genes involved in light harvesting, organic carbon and nitrogen use, and encoding selenium- and metal-requiring enzymes than competing phytoplankton. Genes for the synthesis of microbial deterrents likely permit the proliferation of this species, with reduced mortality losses during blooms. Collectively, these findings suggest that anthropogenic activities resulting in elevated levels of turbidity, organic matter, and metals have opened a niche within coastal ecosystems that ideally suits the unique genetic capacity of A. anophagefferens and thus, has facilitated the proliferation of this and potentially other HABs.

Grigoriev, Igor; Gobler, Christopher; Salamov, Asaf; Kuo, Alan; Terry, Astrid; Pangillian, Jasmyn; Lindquist, Erika; Lucas, Susan; Berry, Dianna; Dyhrman, Sonya; Wilhelm, Steven; Lobanov, Alexei; Zhang, Yan; Collier, Jackie; Wurch, Louie; Kusta, Adam; Dill, Brian; Shsh, Manesh; VerBerkmoes, Nathan; Paulsen, Ian; Hattenrath-Lehmann, Theresa; Talmage, Stephanie; Walker, Elyse; Koch, Florian; Burson, Amanda; Marcoval, Maria; Tang, Yin-Zhong; LeCleir, Gary; Coyne, Kathyrn; Berg, Gry; Bertrand, Erin; Saito, Mak; Gladyshev, Vadim

2011-02-18

469

Niche of harmful alga Aureococcus anophagefferens revealed through ecogenomics  

SciTech Connect

Harmful algal blooms (HABs) cause significant economic and ecological damage worldwide. Despite considerable efforts, a comprehensive understanding of the factors that promote these blooms has been lacking because the biochemical pathways that facilitate their dominance relative to other phytoplankton within specific environments have not been identified. Here, biogeochemical measurements demonstrated that the harmful alga Aureococcus anophagefferens outcompeted co-occurring phytoplankton in estuaries with elevated levels of dissolved organic matter and turbidity and low levels of dissolved inorganic nitrogen. We subsequently sequenced the first HAB genome (A. anophagefferens) and compared its gene complement to those of six competing phytoplankton species identified via metaproteomics. Using an ecogenomic approach, we specifically focused on the gene sets that may facilitate dominance within the environmental conditions present during blooms. A. anophagefferens possesses a larger genome (56 mbp) and more genes involved in light harvesting, organic carbon and nitrogen utilization, and encoding selenium- and metal-requiring enzymes than competing phytoplankton. Genes for the synthesis of microbial deterrents likely permit the proliferation of this species with reduced mortality losses during blooms. Collectively, these findings suggest that anthropogenic activities resulting in elevated levels of turbidity, organic matter, and metals have opened a niche within coastal ecosystems that ideally suits the unique genetic capacity of A. anophagefferens and thus has facilitated the proliferation of this and potentially other HABs.

Gobler, C J; Grigoriev, I V; Berry, D L; Dyhrman, S T; Wilhelm, S W; Salamov, A; Lobanov, A V; Zhang, Y; Collier, J L; Wurch, L L; Kustka, A B; Dill, B D; Shah, M; VerBerkomes, N C; Kuo, A; Terry, A; Pangilinan, J; Lindquist, E A; Lucas, S; Paulsen, I; Hattenrath-Lehmann, T K; Talmage, S; Walker, E A; Koch, F; Burson, A M; Marcoval, M A; Tang, Y; LeCleir, G R; Coyne, K J; Berg, G M; Bertrand, E M; Saito, M A; Gladyshev, V N

2011-03-02

470

Aspects of chemoattractant recognition by the alga Dunaliella tertiolecta  

SciTech Connect

Studies on the molecular nature of algal chemotaxis were performed using the halophilic chlorophyte Dunaliella tertiolecta as a model. Several physical and chemical parameters for generation of maximum chemotactic response in capillary assays are described. Inhibition of chemotaxis to NH/sub 4//sup +/ and several aromatic amino acid by sublethal concentrations of certain heavy metals, including Zn/sup 2 +/, Co/sup 2 +/, Ni/sup 2 +/, Cu/sup 2 +/, and Hg/sup 2 +/ is demonstrated. Inhibition by Zn/sup 2/ of the response of NH/sub 4//sup +/ is partially reversed by increased concentrations of Ca/sup 2 +/. Attraction of L-phenylalanine, L-tyrosine, L-tryptophan, their structural analogs, and other compounds has been quantified using a capillary assay. Radiolabeled L-phenylalanine was used as a ligand to investigate algal binding and uptake. No internalization of the amino acid by D. tertiolectra occurred, even after 3 hr. Specific binding of /sup 3/H-L-phenylalanine was below 100 molecules per alga at 10/sup -8/ M L-phenylalanine. No evidence for the alteration of L-phenylalnine by D. tertiolecta was found following 22 hr incubation with the substrate in light or darkness. To further probe the molecular components of the chemosensory system of D. tertiolecta, a procedure for isolation and purification of trinitrobenzene sulfonic acid (TNBS)-labeled plasma membrane vesicles was developed. Plasma membrane purity was assessed by criteria of chlorophyll content, succinic dehydrogenase activity and protein pattern.

Millard, P.J.

1984-01-01

471

Whorl morphogenesis in the dasycladalean algae: the pattern formation viewpoint.  

PubMed Central

The dasycladalean algae produce diverse whorled structures, among which the best known are the vegetative and reproductive whorls of Acetabularia acetabulum. In this paper, we review the literature pertaining to the origin of these structures. The question is addressed in terms of the necessary pattern-forming events and the possible mechanisms involved, an outlook we call the pattern formation viewpoint. The pattern-forming events involved in the morphogenesis of the vegetative and reproductive whorls of Acetabularia have been used to define five and six morphogenetic stages, respectively. We discuss three published mechanisms which account, at least in part, for the pattern-forming events. The mechanisms are mechanical buckling of the cell wall, reaction-diffusion of morphogen molecules along the cell membrane, and mechanochemical interactions between Ca2+ ions and the cytoskeleton in the cytosol. The numerous differences between these mechanisms provide experimental grounds to test their validity. To date, the results of these experiments point towards reaction diffusion as the most likely patterning mechanism. Finally, we consider the evolutionary origin of the vegetative and reproductive whorls and provide mechanistic explanations for some of the major evolutionary advances. PMID:10724462

Dumais, J; Harrison, L G

2000-01-01

472

Phylogenetic and molecular analysis of hydrogen-producing green algae  

PubMed Central

A select set of microalgae are reported to be able to catalyse photobiological H2 production from water. Based on the model organism Chlamydomonas reinhardtii, a method was developed for the screening of naturally occurring H2-producing microalgae. By purging algal cultures with N2 in the dark and subsequent illumination, it is possible to rapidly induce photobiological H2 evolution. Using NMR spectroscopy for metabolic profiling in C. reinhardtii, acetate, formate, and ethanol were found to be key compounds contributing to metabolic variance during the assay. This procedure can be used to test algal species existing as axenic or mixed cultures for their ability to produce H2. Using this system, five algal isolates capable of H2 production were identified in various aquatic systems. A phylogenetic tree was constructed using ribosomal sequence data of green unicellular algae to determine if there were taxonomic patterns of H2 production. H2-producing algal species were seen to be dispersed amongst most clades, indicating an H2-producing capacity preceded evolution of the phylum Chlorophyta. PMID:19342428

Timmins, Matthew; Thomas-Hall, Skye R.; Darling, Aaron; Zhang, Eugene; Hankamer, Ben; Marx, Ute C.; Schenk, Peer M.

2009-01-01

473

Electron Radiation Damage of (alga) As-gaas Solar Cells  

NASA Technical Reports Server (NTRS)

Solar cells (2 cm by 2 cm (AlGa) As-GaAs cells) were fabricated and then subjected to irradiation at normal incidence by electrons. The influence of junction depth and n-type buffer layer doping level on the cell's resistance to radiation damage was investigated. The study shows that (1) a 0.3 micrometer deep junction results in lower damage to the cells than does a 0.5 micrometer junction, and (2) lowering the n buffer layer doping density does not improve the radiation resistance of the cell. Rather, lowering the doping density decreases the solar cell's open circuit voltage. Some preliminary thermal annealing experiments in vacuum were performed on the (AlGa)As-GaAs solar cells damaged by 1-MeV electron irradiation. The results show that cell performance can be expected to partially recover at 200 C with more rapid and complete recovery occurring at higher temperature. For a 0.5hr anneal at 400 C, 90% of the initial power is recovered. The characteristics of the (AlGa)As-GaAs cells both before and after irradiation are described.

Loo, R.; Kamath, G. S.; Knechtli, R.

1979-01-01

474

Kinetic model for supercritical water gasification of algae.  

PubMed

The article reports the first quantitative kinetics model for supercritical water gasification (SCWG) of real biomass (algae) that describes the formation of the individual gaseous products. The phenomenological model is based on a set of reaction pathways that includes two types of compounds being intermediate between the algal biomass and the final gaseous products. To best correlate the experimental gas yields obtained at 450, 500 and 550 °C, the model allowed one type of intermediate to react to gases more quickly than the other type of intermediate. The model parameters indicate that gas yields increase with temperature because higher temperatures favor production of the more easily gasified intermediate and the production of gas at the expense of char. The model can accurately predict the qualitative influence of the biomass loading and water density on the gas yields. Sensitivity analysis and reaction rate analysis indicate that steam reforming of intermediates is an important source of H(2), whereas direct decomposition of the intermediate species is the main source of CO, CO(2) and CH(4). PMID:22286322

Guan, Qingqing; Wei, Chaohai; Savage, Phillip E

2012-03-01

475

The occurrence of hormesis in plants and algae.  

PubMed

This paper evaluated the frequency, magnitude and dose/concentration range of hormesis in four species: The aquatic plant Lemna minor, the micro-alga Pseudokirchneriella subcapitata and the two terrestrial plants Tripleurospermum inodorum and Stellaria media exposed to nine herbicides and one fungicide and binary mixtures thereof. In total 687 dose-response curves were included in the database. The study showed that both the frequency and the magnitude of the hormetic response depended on the endpoint being measured. Dry weight at harvest showed a higher frequency and a larger hormetic response compared to relative growth rates. Evaluating hormesis for relative growth rates for all species showed that 25% to 76% of the curves for each species had treatments above 105% of the control. Fitting the data with a dose-response model including a parameter for hormesis showed that the average growth increase ranged from 9+/-1% to 16+/-16% of the control growth rate, while if measured on a dry weight basis the response increase was 38+/-13% and 43+/-23% for the two terrestrial species. Hormesis was found in >70% of the curves with the herbicides glyphosate and metsulfuron-methyl, and in >50% of the curves for acifluorfen and terbuthylazine. The concentration ranges of the hormetic part of the dose-response curves corresponded well with literature values. PMID:18648603

Cedergreen, Nina; Streibig, Jens C; Kudsk, Per; Mathiassen, Solvejg K; Duke, Stephen O

2007-01-01

476

The Occurrence of Hormesis in Plants and Algae  

PubMed Central

This paper evaluated the frequency, magnitude and dose/concentration range of hormesis in four species: The aquatic plant Lemna minor, the micro-alga Pseudokirchneriella subcapitata and the two terrestrial plants Tripleurospermum inodorum and Stellaria media exposed to nine herbicides and one fungicide and binary mixtures thereof. In total 687 dose-response curves were included in the database. The study showed that both the frequency and the magnitude of the hormetic response depended on the endpoint being measured. Dry weight at harvest showed a higher frequency and a larger hormetic response compared to relative growth rates. Evaluating hormesis for relative growth rates for all species showed that 25% to 76% of the curves for each species had treatments above 105% of the control. Fitting the data with a dose-response model including a parameter for hormesis showed that the average growth increase ranged from 9±1% to 16±16% of the control growth rate, while if measured on a dry weight basis the response increase was 38±13% and 43±23% for the two terrestrial species. Hormesis was found in >70% of the curves with the herbicides glyphosate and metsulfuron-methyl, and in >50% of the curves for acifluorfen and terbuthylazine. The concentration ranges of the hormetic part of the dose-response curves corresponded well with literature values. PMID:18648603

Cedergreen, Nina; Streibig, Jens C.; Kudsk, Per; Mathiassen, Solvejg K.; Duke, Stephen O.

2007-01-01

477

Bioconvection in Cultures of the Calcifying Unicellular Alga Pleurochrysis Carterae  

NASA Technical Reports Server (NTRS)

The unicellular, marine, calcifying alga P leurochiysis carterae--a model to study cell morphogenesis, cell polarity, calcification, gravitaxis, reproduction and development-- has extremely flexible culture requirements. Support studies for a flight experiment addressing cell motility suggested that cell density (cells/ml) affects cell movement in P. carterae cultures through the gradual establishment of bioconvection as the culture grows. To assess the effect of cell density on direction of the movement, without the effects of aging of the culture, swimming behavior was analyzed in aliquots from a series of dilutions obtained from a stock culture. Results showed that at low concentrations cells swim randomly. As the concentration increases, upswimming patterns overtake random swimming. Gradually, up and down movement patterns prevail, representative of bioconvection. This oriented swimming of P. carterae occurs in a wide range of concentrations, adding to the list of flexible requirements, in this case, cell concentration, to be used for spaceflight studies addressing cell motility and bioconvection in a unicellular model of biologically directed mineralization.

Montufar-Solis, Dina; Duke, P. Jackie; Marsh, Mary E.

2003-01-01

478

Age-dependent changes in the content of lipids, fatty acids, and pigments in brown alga Costaria costata  

Microsoft Academic Search

The contents of lipids and pigments were compared in juvenile and adult algae Costaria costata [Turn.] Saund (Laminariaceae) collected in April. The total content of lipids and that of particular lipid classes increased\\u000a markedly with age. In adult algae, the contents of total lipids, glyceroglycolipids, and neutral lipids doubled as compared\\u000a with juvenile algae and was equal to 5.70, 1.78,

N. I. Gerasimenko; N. G. Busarova; O. P. Moiseenko

2010-01-01

479

Why are there few algae on snail shells? The effects of grazing, nutrients and shell chemistry on the algae on shells of Helisoma trivolvis  

Microsoft Academic Search

SUMMARY 1. Freshwater snails often lack visible growths of algae on their shells. We tested three possible mechanisms that may account for this (grazing, snail-derived nutrients and chemical defences), using the ramshorn snail Helisoma trivolvis. 2. The experiments were carried out in floating plastic enclosures in a pond and comprised seven treatments. Grazing treatments were: a lone snail (ungrazed, as

LINDSEY L. ABBOTT; ELIZABETH A. BERGEY

2007-01-01

480

Origin of land plants: Do conjugating green algae hold the key?  

PubMed Central

Background The terrestrial habitat was colonized by the ancestors of modern land plants about 500 to 470 million years ago. Today it is widely accepted that land plants (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 such as the stoneworts (Charales). For a better understanding of the evolution of land plants, it is of prime importance to identify the streptophyte algae that are the sister-group to the embryophytes. The Charales, the Coleochaetales or more recently the Zygnematales have been considered to be the sister group of the embryophytes However, despite many years of phylogenetic studies, this question has not been resolved and remains controversial. Results Here, we use a large data set of nuclear-encoded genes (129 proteins) from 40 green plant taxa (Viridiplantae) including 21 embryophytes and six streptophyte algae, representing all major streptophyte algal lineages, to investigate the phylogenetic relationships of streptophyte algae and embryophytes. Our phylogenetic analyses indicate that either the Zygnematales or a clade consisting of the Zygnematales and the Coleochaetales are the sister group to embryophytes. Conclusions Our analyses support the notion that the Charales are not the closest living relatives of embryophytes. Instead, the Zygnematales or a clade consisting of Zygnematales and Coleochaetales are most likely the sister group of embryophytes. Although this result is in agreement with a previously published phylogenetic study of chloroplast genomes, additional data are needed to confirm this conclusion. A Zygnematales/embryophyte sister group relationship has important implications for early land plant evolution. If substantiated, it should allow us to address important questions regarding the primary adaptations of viridiplants during the conquest of land. Clearly, the biology of the Zygnematales will receive renewed interest in the future. PMID:21501468

2011-01-01

481

Tracing floating green algae blooms in the Yellow Sea and the East China Sea using Lagrangian transport simulations  

NASA Astrophysics Data System (ADS)

Lagrangian particle tracking experiments were conducted to understand the pathway of the floating green algae patches observed in the Yellow Sea (YS) and East China Sea (ECS) in summer 2011. The numerical simulation results indicated that dominant southerly winds during June and July 2011 were related to offshore movement of the floating green algae, especially their eastward extension in the YS/ECS. An infrequent and unusual event occurred in June 2011: a severe Tropical Strom MEARI, caused the green algae to detach from the coast and initiated movement to the east. After the typhoon event, sea surface temperature recovered rapidly enough to grow the floating green algae, and wind and local current controlled the movement of the massive floating algae patches (coastal accumulation or offshore advection in the area). Analysis of the floating green algae movement using satellite images during passage of Typhoon MAON in July 2011 revealed that the floating green algae patches were significantly controlled by both ocean currents and enhanced winds. These findings suggest that the floating green algae bloom off Qingdao, China and in the middle of the YS and ECS in the summer of 2011 occurred due to the combined effects of recent rapid expansion of seaweed aquaculture, strong winds, and the wind patterns in blooming regions. Our combined approach, using satellite data and numerical simulations, provides a robust estimate for tracing and monitoring changes in green algae blooms on a regional scale.

Park, Young-Gyu; Son, Young Baek; Choi, Byoung-Ju; Kim, Yong Hoon

2014-05-01

482

Seasonal monitoring of coral-algae interactions in fringing reefs of the Gulf of Aqaba, Northern Red Sea  

NASA Astrophysics Data System (ADS)

This paper presents seasonal in situ monitoring data on benthic coverage and coral -algae interactions in high-latitude fringing reefs of the Northern Red Sea over a period of 19 months. More than 30% of all hermatypic corals were involved in interaction with benthic reef algae during winter compared to 17% during summer, but significant correlation between the occurrence of coral -algae interactions and monitored environmental factors such as temperature and inorganic nutrient availability was not detected. Between 5 and 10-m water depth, the macroalgae Caulerpa serrulata, Peyssonnelia capensis and filamentous turf algae represented almost 100% of the benthic algae involved in interaction with corals. Turf algae were most frequently (between 77 and 90% of all interactions) involved in interactions with hermatypic corals and caused most tissue damage to them. Maximum coral tissue loss of 0.75% day-1 was observed for Acropora-turf algae interaction during fall, while an equilibrium between both groups of organisms appeared during summer. Slow-growing massive corals were more resistant against negative algal influence than fast-growing branching corals. Branching corals of the genus Acropora partly exhibited a newly observed phenotypic plasticity mechanism, by development of a bulge towards the competing organism, when in interaction with algae. These findings may contribute to understand the dynamics of phase shifts in coral reefs by providing seasonally resolved in situ monitoring data on the abundance and the competitive dynamic of coral -algae interactions.

Haas, A.; El-Zibdah, M.; Wild, C.

2010-03-01

483

The Mitochondrial Genome of the Entomoparasitic Green Alga Helicosporidium  

PubMed Central

Background Helicosporidia are achlorophyllous, non-photosynthetic protists that are obligate parasites of invertebrates. Highly specialized, these pathogens feature an unusual cyst stage that dehisces inside the infected organism and releases a filamentous cell displaying surface projections, which will penetrate the host gut wall and eventually reproduce in the hemolymph. Long classified as incertae sedis or as relatives of other parasites such as Apicomplexa or Microsporidia, the Helicosporidia were surprisingly identified through molecular phylogeny as belonging to the Chlorophyta, a phylum of green algae. Most phylogenetic analyses involving Helicosporidia have placed them within the subgroup Trebouxiophyceae and further suggested a close affiliation between the Helicosporidia and the genus Prototheca. Prototheca species are also achlorophyllous and pathogenic, but they infect vertebrate hosts, inducing protothecosis in humans. The complete plastid genome of an Helicosporidium species was recently described and is a model of compaction and reduction. Here we describe the complete mitochondrial genome sequence of the same strain, Helicosporidium sp. ATCC 50920 isolated from the black fly Simulium jonesi. Methodology/Principal Findings The circular mapping 49343 bp mitochondrial genome of Helicosporidium closely resembles that of the vertebrate parasite Prototheca wickerhamii. The two genomes share an almost identical gene complement and display a level of synteny that is higher than any other sequenced chlorophyte mitochondrial DNAs. Interestingly, the Helicosporidium mtDNA feature a trans-spliced group I intron, and a second group I intron that contains two open reading frames that appear to be degenerate maturase/endonuclease genes, both rare characteristics for this type of intron. Conclusions/Significance The architecture, genome content, and phylogeny of the Helicosporidium mitochondrial genome are all congruent with its close relationship to Prototheca within the Trebouxiophyceae. The Helicosporidium mitochondrial genome does, however, contain a number of novel features, particularly relating to its introns. PMID:20126458

Pombert, Jean-François; Keeling, Patrick J.

2010-01-01

484

Mechanisms Influencing the Spread of a Native Marine Alga  

PubMed Central

Like invasive macrophytes, some native macrophytes are spreading rapidly with consequences for community structure. There is evidence that the native alga Caulerpa filiformis is spreading along intertidal rocky shores in New South Wales, Australia, seemingly at the expense of native Sargassum spp. We experimentally investigated the role physical disturbance plays in the spread of C. filiformis and its possible consequences for Sargassum spp. Cleared patches within beds of C. filiformis (Caulerpa habitat) or Sargassum spp. (Sargassum habitat) at multiple sites showed that C. filiformis had significantly higher recruitment (via propagules) into its own habitat. The recruitment of Sargassum spp. to Caulerpa habitat was rare, possibly due in part to sediment accretion within Caulerpa habitat. Diversity of newly recruited epibiotic assemblages within Caulerpa habitat was significantly less than in Sargassum habitat. In addition, more C. filiformis than Sargassum spp. recruited to Sargassum habitat at some sites. On common boundaries between these two macroalgae, the vegetative growth of adjacent C. filiformis into cleared patches was significantly higher than for adjacent Sargassum spp. In both experiments, results were largely independent of the size of disturbance (clearing). Lastly, we used PAM fluorometry to show that the photosynthetic condition of Sargassum spp. fronds adjacent to C. filiformis was generally suppressed relative to those distant from C. filiformis. Thus, physical disturbance, combined with invasive traits (e.g. high levels of recruitment and vegetative growth) most likely facilitate the spread of C. filiformis, with the ramifications being lower epibiotic diversity and possibly reduced photosynthetic condition of co-occurring native macrophytes. PMID:24722520

Zhang, Dilys; Glasby, Tim M.; Ralph, Peter J.; Gribben, Paul E.

2014-01-01

485