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Sample records for alga desmodesmus subspicatus

  1. Combination of a higher-tier flow-through system and population modeling to assess the effects of time-variable exposure of isoproturon on the green algae Desmodesmus subspicatus and Pseudokirchneriella subcapitata.

    PubMed

    Weber, Denis; Schaefer, Dieter; Dorgerloh, Michael; Bruns, Eric; Goerlitz, Gerhard; Hammel, Klaus; Preuss, Thomas G; Ratte, Hans Toni

    2012-04-01

    A flow-through system was developed to investigate the effects of time-variable exposure of pesticides on algae. A recently developed algae population model was used for simulations supported and verified by laboratory experiments. Flow-through studies with Desmodesmus subspicatus and Pseudokirchneriella subcapitata under time-variable exposure to isoproturon were performed, in which the exposure patterns were based on the results of FOrum for Co-ordination of pesticide fate models and their USe (FOCUS) model calculations for typical exposure situations via runoff or drain flow. Different types of pulsed exposure events were realized, including a whole range of repeated pulsed and steep peaks as well as periods of constant exposure. Both species recovered quickly in terms of growth from short-term exposure and according to substance dissipation from the system. Even at a peak 10 times the maximum predicted environmental concentration of isoproturon, only transient effects occurred on algae populations. No modified sensitivity or reduced growth was observed after repeated exposure. Model predictions of algal growth in the flow-through tests agreed well with the experimental data. The experimental boundary conditions and the physiological properties of the algae were used as the only model input. No calibration or parameter fitting was necessary. The combination of the flow-through experiments with the algae population model was revealed to be a powerful tool for the assessment of pulsed exposure on algae. It allowed investigating the growth reduction and recovery potential of algae after complex exposure, which is not possible with standard laboratory experiments alone. The results of the combined approach confirm the beneficial use of population models as supporting tools in higher-tier risk assessments of pesticides.

  2. Phytotoxicity and antioxidative enzymes of green microalga (Desmodesmus subspicatus) and duckweed (Lemna minor) exposed to herbicides MCPA, chloridazon and their mixtures.

    PubMed

    Bisewska, Joanna; Sarnowska, Emilia I; Tukaj, Zbigniew H

    2012-09-01

    In this study, we evaluate the toxicity of MCPA (auxin-like growth inhibitor), chloridazon (CHD) (PSII-inhibitor) and their mixtures to floating plants and planktonic algae. Toxicity of MCPA (4-chloro-2-methylphenoxyacetic acid) and CHD (5-amino-4-chloro-2-phenyl-3(2H)-pyridazinone) was first assessed in two growth inhibition tests with Lemna minor (ISO/DIS 20079) and Desmodesmus subspicatus (ISO 8692). Next, herbicide mixtures at concentrations corresponding to the EC values were used to assess their interactive effects, and the biomarkers were: for duckweed fresh weight, frond area, chlorophyll content and number of fronds, and for algae cell count and cell volume. The 3d EC₁₀ and EC₅₀ values using cell counts of D. subspicatus were 142.7 and 529.1 mg/L for MCPA and 1.7 and 5.1 mg/L for CHD. The 7d EC₁₀ and EC₅₀ values using frond number of L. minor amounted to 0.8 and 5.4 mg/L for MCPA and 0.7 and 10.4 mg/L for CHD. Higher sensitivity of reproductive (number of cells/fronds) than growth processes (cell volume/frond area) to herbicides applied individually and in mixtures was especially pronounced in the responses of Desmodesmus. Herbicide interactions were assessed by the two-way ANOVA and Abbott's formula. Generally, an antagonistic interaction with Lemna was revealed by MCPA and chloridazon, whereas additive effect of both herbicides was observed for Desmodesmus. A significant stimulation of SOD and APX activity by binary mixtures was noted in algal cells mainly after 24 and 48 hours of exposure. The extremely high stimulation of the activity of both enzymes was induced by the combination EC₁₀CHD + EC₅₀MCPA (48 h). Presumably due to oxidative stress, the treatment with CHD at concentration EC₅₀ after 72 h was lethal for algae grown in aerated cultures, in contrast to standardized test conditions. Taking into account the consequences of risk assessment for herbicide mixtures we can state that a relatively low toxicity, as well as the

  3. Uptake of caprolactam and its influence on growth and oxygen production of Desmodesmus quadricauda algae.

    PubMed

    Kalinová, Jana Pexová; Tříska, Jan; Vrchotová, Naděžda; Novák, Jan

    2016-06-01

    The consumption of polyamides produced from caprolactam is increasing continuously, and for that reason the danger of environmental contamination by this lactam is also rising. This study's aim was to evaluate the influence of caprolactam on the growth and oxygen production of the green alga Desmodesmus quadricauda and on caprolactam uptake by this alga. The presence of caprolactam in water was observed to cause the algae significantly to increase its oxygen production. Caprolactam concentration of 5,000 mg/L stopped algae growth after 6 days and influenced coenobia structure (seen as disappearance of pyrenoids, deformation of cells) but did not decrease the number of cells in the coenobia. Caprolactam uptake is probably passive but relatively rapid. Maximum concentration in the algae was reached after 18-24 h.

  4. Adaptation strategies of two closely related Desmodesmus armatus (green alga) strains contained different amounts of cadmium: a study with light-induced synchronized cultures of algae.

    PubMed

    Pokora, Wojciech; Baścik-Remisiewicz, Agnieszka; Tukaj, Stefan; Kalinowska, Renata; Pawlik-Skowrońska, Barbara; Dziadziuszko, Małgorzata; Tukaj, Zbigniew

    2014-01-15

    During the Desmodesmus armatus cell cycle, 8-celled coenobia of 276-4d strain accumulated a much lower amounts of cadmium than unicells of B1-76 strain. Cadmium reduced growth and photosynthesis in the cells of strain B1-76, but not those of 276-4d strain. Cells of 276-4d strain revealed a higher activity of superoxide dismutase (SOD) isoforms, in particular the activity and protein content of Fe-SOD. Cu/Zn-SOD was earlier and much stronger induced by cadmium in 276-4d than in B1-76 strain, whereas Fe- and Mn-SOD activity and Fe-SOD synthesis were induced only in 276-4d strain. Cadmium did not affect the heat shock protein 70 synthesis in B1-76 strain, but significantly stimulated this process in 276-4d strain. The level of glutathione increased 30-fold during cell development of Cd-exposed 276-4d strain, while in B1-76 it increased about 12 timed. Matured cells of both strains exposed to cadmium produced comparable amounts of phytochelatins and other thiol peptides, but their production in young cells of B1-76 strain was much higher than in 276-4d strain. In conclusion, a complex of internal detoxification mechanisms appeared to be more efficient in cells of 276-4d strain than B1-76 one.

  5. Induction time of Fe-SOD synthesis and activity determine different tolerance of two Desmodesmus (green algae) strains to chloridazon: a study with synchronized cultures.

    PubMed

    Pokora, Wojciech; Tukaj, Zbigniew

    2013-09-01

    Cells of two Desmodesmus armatus strains (276-4a and 276-4d) grown asynchronously in batch cultures after 24-h treatment revealed different tolerance to chloridazon (photosynthetic herbicide) applied at a concentration of 3.45 mg L(-1). To find time- and cell cycle-dependent biochemical reasons leading to such a difference, a population of young autospores of both strains synchronized by a light/dark (14/10) regime were exposed to chloridazon at the initiation of the light period. Chloridazon reduced the growth and number of divisions of cell strain 276-4d. In consequence, at the end of the dark phase the number of released autospores was reduced by 50% compared with the control. In contrast, the growth and reproductive processes of cell strains 276-4a was unaffected. Moreover, chloridazon treatment speeded up cell development, as a result of which the release of autospores took this process observed in the control cells over. There is a relationship between photosynthetic activity response to chloridazon and time-dependent changes in Fe-SOD content and activity. The energy trapped in the reaction centre (RC) was similar in both strains, but the amount of energy absorbed by RCs was twice as high in strain 276-4d as in 276-4a. In consequence, non-photochemical energy dissipation occurring in the cells of 276-4d strain far exceed the value obtained for 276-4a strain. The control cells of both strains differed significantly in the content of FSD 1 and FSD 2 proteins, whereas the differences in Fe-SOD isoforms activities were slight. The 8-fold increase in SOD content in CHD treated cells of strain 276-4a was associated with the transience of photosynthetic efficiency impairment. In CHD treated cells of strain 276-4d, neither activity of Fe-SOD nor FSDs protein content was instantly affected. Different response of developing cells of two Desmodesmus strains to CHD is influenced by the inherent features of cells; the short time required to induce stress adaptive

  6. Toxicity of surfactants to green microalgae Pseudokirchneriella subcapitata and Scenedesmus subspicatus and to marine diatoms Phaeodactylum tricornutum and Skeletonema costatum.

    PubMed

    Pavlić, Zelimira; Vidaković-Cifrek, Zeljka; Puntarić, Dinko

    2005-12-01

    Ecotoxicity of different commercial surfactants (six anionic, two amphoteric and one nonionic), essential constituents of cleansing hair products (shampoos), as well as ecotoxicity of eight shampoos containing different combinations of these surfactants, were tested in order to evaluate their possible toxic effects on microalgae. Specific objective of this research was to compare the sensitivity of selected freshwater and marine microalgae to these widely used surfactants and well-known pollutants in surface waters. Internationally validated methods (ISO standards) for the determination of toxic effects on the growth of planktonic freshwater green algae Pseudokirchneriella subcapitata and Scenedesmus subspicatus and marine diatoms Skeletonema costatum and Phaeodactylum tricornutum, were used. The obtained results showed that the concentrations of tested surfactants and shampoos, which resulted in 50% growth reduction of planktonic freshwater green algae, when compared to the controls without test substances (EC50), were in the range from 0.32 to 4.4 mg l(-1) for surfactants and from 2.1 to 8.5 mg l(-1) for shampoos expressed as active substance. Marine diatoms were significantly more sensitive to the tested surfactants than freshwater green algae (EC50 0.14-1.7 mg l(-1) for surfactants and 0.35-1.25 mg l(-1) for shampoos). According to the classification on the basis of environmental effects, the obtained results suggested that all tested surfactants can be classified as having toxic effects on freshwater green alga Pseudokirchneriella subcapitata. Some of them indicated that they have a very toxic effect on Scenedesmus subspicatus and marine diatoms Skeletonema costatum and Phaeodactylum tricornutum.

  7. Algae.

    PubMed

    Raven, John A; Giordano, Mario

    2014-07-01

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

  8. Algae.

    PubMed

    Raven, John A; Giordano, Mario

    2014-07-01

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

  9. Bioremediation of wastewater from edible oil refinery factory using oleaginous microalga Desmodesmus sp. S1.

    PubMed

    Mar, Cho Cho; Fan, Yong; Li, Fu-Li; Hu, Guang-Rong

    2016-12-01

    Edible oil industry produced massive wastewater, which requires extensive treatment to remove pungent smell, high phosphate, carbon oxygen demand (COD), and metal ions prior to discharge. Traditional anaerobic and aerobic digestion could mainly reduce COD of the wastewater from oil refinery factories (WEORF). In this study, a robust oleaginous microalga Desmodesmus sp. S1 was adapted to grow in WEORF. The biomass and lipid content of Desmodesmus sp. S1 cultivated in the WEORF supplemented with sodium nitrate were 5.62 g·L(-1) and 14.49%, whereas those in the WEORF without adding nitrate were 2.98 g·L(-1) and 21.95%. More than 82% of the COD and 53% of total phosphorous were removed by Desmodesmus sp. S1. In addition, metal ions, including ferric, aluminum, manganese and zinc were also diminished significantly in the WEORF after microalgal growth, and pungent smell vanished as well. In comparison with the cells grown in BG-11 medium, the cilia-like bulges and wrinkles on the cell surface of Desmodesmus sp. S1 grown in WEORF became out of order, and more polyunsaturated fatty acids were detected due to stress derived from the wastewater. The study suggests that growing microalgae in WEORF can be applied for the dual roles of nutrient removal and biofuel feedstock production.

  10. Bioremediation of wastewater from edible oil refinery factory using oleaginous microalga Desmodesmus sp. S1.

    PubMed

    Mar, Cho Cho; Fan, Yong; Li, Fu-Li; Hu, Guang-Rong

    2016-12-01

    Edible oil industry produced massive wastewater, which requires extensive treatment to remove pungent smell, high phosphate, carbon oxygen demand (COD), and metal ions prior to discharge. Traditional anaerobic and aerobic digestion could mainly reduce COD of the wastewater from oil refinery factories (WEORF). In this study, a robust oleaginous microalga Desmodesmus sp. S1 was adapted to grow in WEORF. The biomass and lipid content of Desmodesmus sp. S1 cultivated in the WEORF supplemented with sodium nitrate were 5.62 g·L(-1) and 14.49%, whereas those in the WEORF without adding nitrate were 2.98 g·L(-1) and 21.95%. More than 82% of the COD and 53% of total phosphorous were removed by Desmodesmus sp. S1. In addition, metal ions, including ferric, aluminum, manganese and zinc were also diminished significantly in the WEORF after microalgal growth, and pungent smell vanished as well. In comparison with the cells grown in BG-11 medium, the cilia-like bulges and wrinkles on the cell surface of Desmodesmus sp. S1 grown in WEORF became out of order, and more polyunsaturated fatty acids were detected due to stress derived from the wastewater. The study suggests that growing microalgae in WEORF can be applied for the dual roles of nutrient removal and biofuel feedstock production. PMID:27260474

  11. Assessment of acrylamide toxicity using a battery of standardised bioassays.

    PubMed

    Zovko, Mira; Vidaković-Cifrek, Željka; Cvetković, Želimira; Bošnir, Jasna; Šikić, Sandra

    2015-12-01

    Acrylamide is a monomer widely used as an intermediate in the production of organic chemicals, e.g. polyacrylamides (PAMs). Since PAMs are low cost chemicals with applications in various industries and waste- and drinking water treatment, a certain amount of non-polymerised acrylamide is expected to end up in waterways. PAMs are non-toxic but acrylamide induces neurotoxic effects in humans and genotoxic, reproductive, and carcinogenic effects in laboratory animals. In order to evaluate the effect of acrylamide on freshwater organisms, bioassays were conducted on four species: algae Desmodesmus subspicatus and Pseudokirchneriella subcapitata, duckweed Lemna minor and water flea Daphnia magna according to ISO (International Organization for Standardisation) standardised methods. This approach ensures the evaluation of acrylamide toxicity on organisms with different levels of organisation and the comparability of results, and it examines the value of using a battery of low-cost standardised bioassays in the monitoring of pollution and contamination of aquatic ecosystems. These results showed that EC50 values were lower for Desmodesmus subspicatus and Pseudokirchneriella subcapitata than for Daphnia magna and Lemna minor, which suggests an increased sensitivity of algae to acrylamide. According to the toxic unit approach, the values estimated by the Lemna minor and Daphnia magna bioassays, classify acrylamide as slightly toxic (TU=0-1; Class 1). The results obtained from algal bioassays (Desmodesmus subspicatus and Pseudokirchneriella subcapitata) revealed the toxic effect of acrylamide (TU=1-10; Class 2) on these organisms.

  12. Assessment of acrylamide toxicity using a battery of standardised bioassays.

    PubMed

    Zovko, Mira; Vidaković-Cifrek, Željka; Cvetković, Želimira; Bošnir, Jasna; Šikić, Sandra

    2015-12-01

    Acrylamide is a monomer widely used as an intermediate in the production of organic chemicals, e.g. polyacrylamides (PAMs). Since PAMs are low cost chemicals with applications in various industries and waste- and drinking water treatment, a certain amount of non-polymerised acrylamide is expected to end up in waterways. PAMs are non-toxic but acrylamide induces neurotoxic effects in humans and genotoxic, reproductive, and carcinogenic effects in laboratory animals. In order to evaluate the effect of acrylamide on freshwater organisms, bioassays were conducted on four species: algae Desmodesmus subspicatus and Pseudokirchneriella subcapitata, duckweed Lemna minor and water flea Daphnia magna according to ISO (International Organization for Standardisation) standardised methods. This approach ensures the evaluation of acrylamide toxicity on organisms with different levels of organisation and the comparability of results, and it examines the value of using a battery of low-cost standardised bioassays in the monitoring of pollution and contamination of aquatic ecosystems. These results showed that EC50 values were lower for Desmodesmus subspicatus and Pseudokirchneriella subcapitata than for Daphnia magna and Lemna minor, which suggests an increased sensitivity of algae to acrylamide. According to the toxic unit approach, the values estimated by the Lemna minor and Daphnia magna bioassays, classify acrylamide as slightly toxic (TU=0-1; Class 1). The results obtained from algal bioassays (Desmodesmus subspicatus and Pseudokirchneriella subcapitata) revealed the toxic effect of acrylamide (TU=1-10; Class 2) on these organisms. PMID:26751864

  13. Fed-batch cultivation of Desmodesmus sp. in anaerobic digestion wastewater for improved nutrient removal and biodiesel production.

    PubMed

    Ji, Fang; Zhou, Yuguang; Pang, Aiping; Ning, Li; Rodgers, Kibet; Liu, Ying; Dong, Renjie

    2015-05-01

    Desmodesmus sp. was used in anaerobically digested wastewater (ADW) for nutrients removal and the biodiesel production was measured and compared using fed-batch cultivation was investigated and compared with batch cultivation. The Desmodesmus sp. was able to remove 236.143, 268.238 and 6.427 mg/L of TN, NH4-N and PO4-P respectively after 40 d of fed-batch cultivation, while in batch cultivation the quantities of TN, NH4-N and PO4-P removed were 33.331, 37.227 and 1.323 mg/L. Biomass production of Desmodesmus sp. was also enhanced in fed-batch cultivation, when ADW loading was carried out every 2 days; the biomass concentration peaked at 1.039 g/L, which was three times higher than that obtained in batch cultivation (0.385 g/L). The highest lipid production (261.8 mg/L) was also recorded in fed-batch cultivation as compared to batch cultivation (83.3 mg/L). Fed-batch cultivation of Desmodesmus sp. could provide effective control of nutrients limitation and/or ammonia inhibition on microalgae cultivation.

  14. Zinc tolerance and zinc removal ability of living and dried biomass of Desmodesmus communis.

    PubMed

    Novák, Zoltán; Jánószky, Mihály; B-Béres, Viktória; Nagy, Sándor Alex; Bácsi, István

    2014-12-01

    Effects of zinc on growth, cell morphology, oxidative stress, and zinc removal ability of the common phytoplankton species Desmodesmus communis were investigated at a concentration range of 0.25-160 mg L(-1) zinc. Cell densities and chlorophyll content decreased in treated cultures, changes in coenobia morphology and elevated lipid peroxidation levels appeared above 2.5 mg L(-1) zinc. The most effective zinc removal was observed at 5 mg L(-1) zinc concentration, while maximal amount of removed zinc appeared in 15 mg L(-1) zinc treated culture. Removed zinc is mainly bound on the cell surface. Dead biomass adsorbed more zinc than living biomass relative to unit of dry mass, but living biomass was more effective, relative to initial zinc content. This study comprehensively examines the zinc tolerance and removal ability of D. communis and demonstrates, in comparison with published literature, that these characteristics of different isolates of the same species can vary within a wide range. PMID:25193446

  15. Enhanced Lipid Productivity and Photosynthesis Efficiency in a Desmodesmus sp. Mutant Induced by Heavy Carbon Ions

    PubMed Central

    Hu, Guangrong; Fan, Yong; Zhang, Lei; Yuan, Cheng; Wang, Jufang; Li, Wenjian; Hu, Qiang; Li, Fuli

    2013-01-01

    The unicellular green microalga Desmodesmus sp. S1 can produce more than 50% total lipid of cell dry weight under high light and nitrogen-limitation conditions. After irradiation by heavy 12C6+ ion beam of 10, 30, 60, 90 or 120 Gy, followed by screening of resulting mutants on 24-well microplates, more than 500 mutants were obtained. One of those, named D90G-19, exhibited lipid productivity of 0.298 g L−1⋅d−1, 20.6% higher than wild type, likely owing to an improved maximum quantum efficiency (Fv/Fm) of photosynthesis under stress. This work demonstrated that heavy-ion irradiation combined with high-throughput screening is an effective means for trait improvement. The resulting mutant D90G-19 may be used for enhanced lipid production. PMID:23593286

  16. Diversity of the nitrogen starvation responses in subarctic Desmodesmus sp. (Chlorophyceae) strains isolated from symbioses with invertebrates.

    PubMed

    Baulina, Olga; Gorelova, Olga; Solovchenko, Alexei; Chivkunova, Olga; Semenova, Larisa; Selyakh, Irina; Scherbakov, Pavel; Burakova, Olga; Lobakova, Elena

    2016-04-01

    We report on common and strain-specific responses to nitrogen (N) starvation recorded in four closely related symbiotic Desmodesmus strains from taxonomically very distant animals (hydroids, a sponge and a polychaete) dwelling in the White Sea. A number of common for the studied strains and free-living microalgae as well as some specific patterns of acclimation to the N starvation were documented. The common responses included a slowdown of cell division, a reduction of photosynthetic apparatus and a vast expansion of storage subcompartments of the cell. Although these responses were qualitatively similar to those known in free-living chlorophytes, in the studied strains they occurred in a strain-specific manner. The specific N-starvation responses comprised formation of chloroplast envelope membrane twirls, thinning of the appressed thylakoid membranes and a loss of the luminal depositions and channeling of the fixed carbon to cell wall polysaccharide layer. Desmodesmus sp. from a hydroid featured a unique, among the studied strains, capability of 'emergency' degradation of Rubisco, apparently to salvage the N contained in this protein. The obtained results are discussed in view of the remarkable physiological plasticity of the symbiotic Desmodesmus spp. and their survival under the harsh conditions of the subarctic sea habitat. PMID:26880784

  17. Phototrophic cultivation of a thermo-tolerant Desmodesmus sp. for lutein production: effects of nitrate concentration, light intensity and fed-batch operation.

    PubMed

    Xie, Youping; Ho, Shih-Hsin; Chen, Ching-Nen Nathan; Chen, Chun-Yen; Ng, I-Son; Jing, Ke-Ju; Chang, Jo-Shu; Lu, Yinghua

    2013-09-01

    Four indigenous thermo-tolerant Desmodesmus sp. strains were examined for their ability to produce lutein. Among them, Desmodesmus sp. F51 was the best strain for this purpose. The medium composition, nitrate concentration and light intensity were manipulated to improve the phototrophic growth and lutein production of Desmodesmus sp. F51. It was found that a nitrogen-sufficient condition was required for lutein accumulation, while a high light intensity enhanced cell growth but caused a decrease in the lutein content. The best cell growth and lutein production occurred when the light intensity and initial nitrate concentration were 600 μmol/m(2)/s and 8.8 mM, respectively. The fed-batch cultivation strategy was shown to further improve lutein production. The highest lutein productivity (3.56±0.10 mg/L/d) and content (5.05±0.20 mg/g) were obtained when pulse-feeding of 2.2 mM nitrate was employed. This study demonstrated the potential of using Desmodesmus sp. F51 as a lutein producer in practical applications.

  18. Larvicidal algae.

    PubMed

    Marten, Gerald G

    2007-01-01

    Although most algae are nutritious food for mosquito larvae, some species kill the larvae when ingested in large quantities. Cyanobacteria (blue-green algae) that kill larvae do so by virtue of toxicity. While blue-green algae toxins may offer possibilities for delivery as larvicides, the toxicity of live blue-green algae does not seem consistent enough for live algae to be useful for mosquito control. Certain species of green algae in the order Chlorococcales kill larvae primarily because they are indigestible. Where these algae are abundant in nature, larvae consume them to the exclusion of other food and then starve. Under the right circumstances, it is possible to introduce indigestible algae into a breeding habitat so they become abundant enough to render it unsuitable for mosquito production. The algae can persist for years, even if the habitat dries periodically. The main limitation of indigestible algae lies in the fact that, under certain conditions, they may not replace all the nutritious algae in the habitat. More research on techniques to ensure complete replacement will be necessary before indigestible algae can go into operational use for mosquito control.

  19. Effects of UV-A Radiation on Desmodesmus armatus: Changes in Growth Rate, Pigment Content and Morphological Appearance

    NASA Astrophysics Data System (ADS)

    Pálffy, Károly; Vörös, Lajos

    2006-10-01

    Laboratory cultures of Desmodesmus armatus (R. Chod.) Hegew. were grown under different levels of photosynthetically active radiation (PAR) supplemented with 3.75 mW . cm-2 UV-A radiation. Growth rate was monitored daily, chlorophyl-a concentration, total carotenoid content, cell number and the relative abundance of different coenobial forms was determined at the end of each experiment. Exposure to UV-A radiation resulted in an increasing inhibition of growth towards higher PAR levels, reaching 100% at 400 μmol . m-2 . s-1. Cellular carotenoid content was higher in the presence of UV-A radiation, on the other hand no differences were observed in cellular chlorophyll-a concentration. UV-A radiation also induced changes in coenobium formation with a decreasing proportion of 4-celled coenobia and an increase in the abundance of 2-celled and teratologic coenobia, suggesting that high intensity UV-A radiation may influence cell cycle events or morphology development.

  20. The Study of Algae

    ERIC Educational Resources Information Center

    Rushforth, Samuel R.

    1977-01-01

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

  1. Use of lanthanides to alleviate the effects of metal ion-deficiency in Desmodesmus quadricauda (Sphaeropleales, Chlorophyta)

    PubMed Central

    Goecke, Franz; Jerez, Celia G.; Zachleder, Vilém; Figueroa, Félix L.; Bišová, Kateřina; Řezanka, Tomáš; Vítová, Milada

    2015-01-01

    Lanthanides are biologically non-essential elements with wide applications in technology and industry. Their concentration as environmental contaminants is, therefore, increasing. Although non-essential, lanthanides have been proposed (and even used) to produce beneficial effects in plants, even though their mechanisms of action are unclear. Recently, it was suggested that they may replace essential elements. We tested the effect of low concentrations of lanthanides on the common freshwater microalga Desmodesmus quadricauda, grown under conditions of metal ion-deficiency (lower calcium or manganese concentrations). Our goal was to test if lanthanides can replace essential metals in their functions. Physiological stress was recorded by studying growth and photosynthetic activity using a pulse amplitude modulation (PAM) fluorimeter. We found that nutrient stress reduced parameters of growth and photosynthesis, such as maximal quantum yield, relative electron transport rate, photon capturing efficiency and light saturation irradiance. After adding low concentrations of five lanthanides, we confirmed that they can produce a stimulatory effect on microalgae, depending on the nutrient (metal) deprivation. In the case of a calcium deficit, the addition of lanthanides partly alleviated the adverse effects, probably by a partial substitution of the element. In contrast, with manganese deprivation (and at even lower concentrations), lanthanides enhanced the deleterious effect on cellular growth and photosynthetic competence. These results show that lanthanides can replace essential elements, but their effects on microalgae depend on stress and the nutritional state of the microalgae, raising the possibility of environmental impacts at even low concentrations. PMID:25674079

  2. Assessment of the ecotoxic potential of soil contaminants by using a soil-algae test.

    PubMed

    Hammel, W; Steubing, L; Debus, R

    1998-01-01

    To assess the ecotoxic potential of soil contaminants, a test with the soil alga Chlorococcum infusionum has been developed, enabling investigations of soil pollutions with soluble and fairly soluble chemicals. Three soil types artificially contaminated with Sb compounds and five soils from a historical mining area, which were highly polluted with Sb, As, Hg, and Cu, were used as test soils. For antimony, EC50 values from 125 mg/kg up to > 1000 mg/kg, depending on soil type, were determined. Two of five soils from the mining area caused toxic effects. Additionally, aqueous extracts of all soils were exposed in established tests (daphnid, alga, bacterium). In contrast with the soil-algae test, no toxic effects were found. Aquatic tests with SbO/K tartrate were performed to point out the toxicity of antimony. The following EC50 values in milligrams of Sb per liter were determined: Scenedesmus subspicatus, 59 mg/liter; Chlorococcum infusionum, 43 mg/liter; Daphnia magna, 8 mg/liter; and Vibrio fisheri, 7 mg/liter.

  3. Bacterial community composition associated with freshwater algae: species specificity vs. dependency on environmental conditions and source community.

    PubMed

    Eigemann, Falk; Hilt, Sabine; Salka, Ivette; Grossart, Hans-Peter

    2013-03-01

    We studied bacterial associations with the green alga Desmodesmus armatus and the diatom Stephanodiscus minutulus under changing environmental conditions and bacterial source communities, to evaluate whether bacteria-algae associations are species-specific or more generalized and determined by external factors. Axenic and xenic algae were incubated in situ with and without allelopathically active macrophytes, and in the laboratory with sterile and nonsterile lake water and an allelochemical, tannic acid (TA). Bacterial community composition (BCC) of algae-associated bacteria was analyzed by denaturing gradient gel electrophoresis (DGGE), nonmetric multidimensional scaling, cluster analyses, and sequencing of DGGE bands. BCC of xenic algal cultures of both species were not significantly affected by changes in their environment or bacterial source community, except in the case of TA additions. Species-specific interactions therefore appear to overrule the effects of environmental conditions and source communities. The BCC of xenic and axenic D. armatus cultures subjected to in situ bacterial colonization, however, had lower similarities (ca. 55%), indicating that bacterial precolonization is a strong factor for bacteria-algae associations irrespective of environmental conditions and source community. Our findings emphasize the ecological importance of species-specific bacteria-algae associations with important repercussions for other processes, such as the remineralization of nutrients, and organic matter dynamics.

  4. Magnetic separation of algae

    DOEpatents

    Nath, Pulak; Twary, Scott N.

    2016-04-26

    Described herein are methods and systems for harvesting, collecting, separating and/or dewatering algae using iron based salts combined with a magnetic field gradient to separate algae from an aqueous solution.

  5. Effects of non-steroidal anti-inflammatory drugs on cyanobacteria and algae in laboratory strains and in natural algal assemblages.

    PubMed

    Bácsi, István; B-Béres, Viktória; Kókai, Zsuzsanna; Gonda, Sándor; Novák, Zoltán; Nagy, Sándor Alex; Vasas, Gábor

    2016-05-01

    In recent years measurable concentrations of non-steroidal anti-inflammatory drugs (NSAIDs) have been shown in the aquatic environment as a result of increasing human consumption. Effects of five frequently used non-steroidal anti-inflammatory drugs (diclofenac, diflunisal, ibuprofen, mefenamic acid and piroxicam in 0.1 mg ml(-1) concentration) in batch cultures of cyanobacteria (Synechococcus elongatus, Microcystis aeruginosa, Cylindrospermopsis raciborskii), and eukaryotic algae (Desmodesmus communis, Haematococcus pluvialis, Cryptomonas ovata) were studied. Furthermore, the effects of the same concentrations of NSAIDs were investigated in natural algal assemblages in microcosms. According to the changes of chlorophyll-a content, unicellular cyanobacteria seemed to be more tolerant to NSAIDs than eukaryotic algae in laboratory experiments. Growth of eukaryotic algae was reduced by all drugs, the cryptomonad C. ovata was the most sensitive to NSAIDs, while the flagellated green alga H. pluvialis was more sensitive than the non-motile green alga D. communis. NSAID treatments had weaker impact in the natural assemblages dominated by cyanobacteria than in the ones dominated by eukaryotic algae, confirming the results of laboratory experiments. Diversity and number of functional groups did not change notably in cyanobacteria dominated assemblages, while they decreased significantly in eukaryotic algae dominated ones compared to controls. The results highlight that cyanobacteria (especially unicellular ones) are less sensitive to the studied, mostly hardly degradable NSAIDs, which suggest that their accumulation in water bodies may contribute to the expansion of cyanobacterial mass productions in appropriate environmental circumstances by pushing back eukaryotic algae. Thus, these contaminants require special attention during wastewater treatment and monitoring of surface waters.

  6. Trade-offs limiting the evolution of coloniality: ecological displacement rates used to measure small costs.

    PubMed

    Yokota, Kiyoko; Sterner, Robert W

    2011-02-01

    Multicellular organisms that benefit from division of labour are presumably descended from colonial species that initially derived benefits from larger colony size, before the evolution of specialization. Life in a colony can have costs as well as benefits, but these can be hard to measure. We measured physiological costs to life in a colony using a novel method based on population dynamics, comparing growth rates of unicells and kairomone-induced colonies of a green alga Desmodesmus subspicatus against a reference co-occurring species. Coloniality negatively affected growth during the initial log growth phase, while no adverse effect was detected under nutrient-limited competitive conditions. The results point to costs associated with traits involved in rapid growth rather than those associated with efficient growth under resource scarcity. Some benefits of coloniality (e.g. defence from herbivory) may be different from when this trait evolved, but our approach shows how costs would have depended on conditions.

  7. Trade-offs limiting the evolution of coloniality: ecological displacement rates used to measure small costs

    PubMed Central

    Yokota, Kiyoko; Sterner, Robert W.

    2011-01-01

    Multicellular organisms that benefit from division of labour are presumably descended from colonial species that initially derived benefits from larger colony size, before the evolution of specialization. Life in a colony can have costs as well as benefits, but these can be hard to measure. We measured physiological costs to life in a colony using a novel method based on population dynamics, comparing growth rates of unicells and kairomone-induced colonies of a green alga Desmodesmus subspicatus against a reference co-occurring species. Coloniality negatively affected growth during the initial log growth phase, while no adverse effect was detected under nutrient-limited competitive conditions. The results point to costs associated with traits involved in rapid growth rather than those associated with efficient growth under resource scarcity. Some benefits of coloniality (e.g. defence from herbivory) may be different from when this trait evolved, but our approach shows how costs would have depended on conditions. PMID:20739317

  8. Influence of Light Intensity and Temperature on Cultivation of Microalgae Desmodesmus Communis in Flasks and Laboratory-Scale Stirred Tank Photobioreactor

    NASA Astrophysics Data System (ADS)

    Vanags, J.; Kunga, L.; Dubencovs, K.; Galvanauskas, V.; Grīgs, O.

    2015-04-01

    Optimization of the microalgae cultivation process and of the bioprocess in general traditionally starts with cultivation experiments in flasks. Then the scale-up follows, when the process from flasks is transferred into a laboratory-scale bioreactor, in which further experiments are performed before developing the process in a pilot-scale reactor. This research was done in order to scale-up the process from a 0.4 1 shake flask to a 4.0 1 laboratory-scale stirred-tank photobioreactor for the cultivation of Desmodesmus (D.) communis microalgae. First, the effect of variation in temperature (21-29 ºC) and in light intensity (200-600 μmol m-2s-1) was studied in the shake-flask experiments. It was shown that the best results (the maximum biomass concentration of 2.72 g 1-1 with a specific growth rate of 0.65 g g-1d-1) can be achieved at the cultivation temperature and light intensity being 25 °C and 300 μmol m2s-1, respectively. At the same time, D. communis cultivation under the same conditions in stirred-tank photobioreactor resulted in average volumetric productivities of biomass due to the light limitation even when the light intensity was increased during the experiment (the maximum biomass productivity 0.25 g 1-1d-1; the maximum biomass concentration 1.78 g 1-1). Mikroaļģu kultivēšanas procesa optimizēšana parasti sākas ar kultivēšanas eksperimentiem kolbās. Tālāk seko procesa pārnese uz laboratorijas mēroga fotobioreaktoru, kurā tiek veikti tālāki eksperimenti, pirms tiek izveidots pilota mēroga reaktors. Šis pētījums tika veikts ar mērķi, pārnest Desmodesmus communis kultivēšanas procesu no 0.4 1 kolbas uz 4.0 1 laboratorijas fotobioreaktoru. Vispirms tika pētīta dažādu temperatūru (21-29 ºC) un gaismas intensitātes (200-600 μmol m-2s-1) ietekme uz aļģu biomasu veicot eksperimentus kolbās. Labākie rezultāti (maksimālā biomasas koncentrācija 2.72 g 1-1; īpatnējais augšanas ātrums 0.65 g g-1d-1) sasniegti, kad

  9. Growth and nitrogen removal capacity of Desmodesmus communis and of a natural microalgae consortium in a batch culture system in view of urban wastewater treatment: part I.

    PubMed

    Samorì, Giulia; Samorì, Chiara; Guerrini, Franca; Pistocchi, Rossella

    2013-02-01

    The microalgal biomass applications strongly depend on cell composition and the production of low cost products such as biofuels appears to be economically convenient only in conjunction with wastewater treatment. As a preliminary study, in view of the development of a wastewater treatment pilot plant for nutrient removal and algal biomass production, a biological wastewater system was carried out on a laboratory scale growing a newly isolated freshwater algal strain, Desmodesmus communis, and a natural consortium of microalgae in effluents generated by a local wastewater reclamation facility. Batch cultures were operated by using D. communis under different growth conditions to better understand the effects of CO₂, nutrient concentration and light intensity on the biomass productivity and biochemical composition. The results were compared with those obtained using a natural algal consortium. D. communis showed a great vitality in the wastewater effluents with a biomass productivity of 0.138-0.227 g L⁻¹ d⁻¹ in the primary effluent enriched with CO₂, higher biomass productivity compared with the one achieved by the algal consortium (0.078 g L⁻¹ d⁻¹). D. communis cultures reached also a better nutrient removal efficiency compared with the algal consortium culture, with almost 100% for ammonia and phosphorous at any N/P ratio characterizing the wastewater nutrient composition. Biomass composition was richer in polysaccharides and total fatty acids as the ammonia concentration in the water decreased. In view of a future application of this algal biomass, due to the low total fatty acids content of 1.4-9.3 wt% and the high C/N ratio of 7.6-39.3, anaerobic digestion appeared to be the most appropriate biofuel conversion process. PMID:23211134

  10. Algae Derived Biofuel

    SciTech Connect

    Jahan, Kauser

    2015-03-31

    One of the most promising fuel alternatives is algae biodiesel. Algae reproduce quickly, produce oils more efficiently than crop plants, and require relatively few nutrients for growth. These nutrients can potentially be derived from inexpensive waste sources such as flue gas and wastewater, providing a mutual benefit of helping to mitigate carbon dioxide waste. Algae can also be grown on land unsuitable for agricultural purposes, eliminating competition with food sources. This project focused on cultivating select algae species under various environmental conditions to optimize oil yield. Membrane studies were also conducted to transfer carbon di-oxide more efficiently. An LCA study was also conducted to investigate the energy intensive steps in algae cultivation.

  11. Effects of free Cu{sup 2+} and Zn{sup 2+} ions on growth and metal accumulation in freshwater algae

    SciTech Connect

    Knauer, K.; Behra, R.; Sigg, L.

    1997-02-01

    Five species of unicellular green algae were exposed to a broad range of Cu{sup 2+} and Zn{sup 2+} concentrations to examine the relationship between the free Cu{sup 2+} and Zn{sup 2+} ion concentrations and algal growth at metal concentrations relevant for freshwater phytoplankton. The authors estimated extra- and intracellular metal concentrations and characterized the adsorption of copper and zinc on algal surfaces. The optimal growth rate of Scenedesmus subspicatus occurred in a broad range of Cu{sup 2+} and Zn{sup 2+} concentrations (from 10{sup {minus}15} to 10{sup {minus}7} and from 10{sup {minus}12} to 10{sup {minus}55} M, respectively). Chlamydomonas reinhardtii reacted more sensitively toward copper, optimal growth was achieved only at a pCu (= {minus}log[Cu{sup 2+}]) around 11, whereas growth was optimal over about three orders of magnitude of the free Cu{sup 2+} concentration (from 10{sup {minus}13} to 10{sup {minus}10} M). Chlamydomonas cultures isolated from Lake Constance tolerated Cu{sup 2+} concentrations over seven orders of magnitude (pCu = 7 to 14). The growth of algae showed a high tolerance toward high intracellular copper and zinc concentrations. This suggests that the cells may immobilize the metals intracellularly. The affinity of copper for algal surfaces is higher than that of zinc in the experimental concentration range: adsorption constants log K{sub Cu} (11.06) > log K{sub Zn} (6.49) (pH = 7.9). These freshwater algae tolerate higher Cu{sup 2+} and Zn{sup 2+} concentrations than marine algal species. In comparison to the lake data, the results obtained from the culture algae indicate a possible role for copper as a limiting factor for certain algal species in eutrophic lakes.

  12. Blue-green algae

    MedlinePlus

    “Blue-green algae” describes a large and diverse group of simple, plant-like organisms found in salt water and some large fresh water lakes. Blue-green algae products are used for many conditions, but so ...

  13. Nutrient removal efficiency and physiological responses of Desmodesmus communis at different HRTs and nutrient stress condition using different sources of urban wastewater effluents.

    PubMed

    Samorì, Giulia; Samorì, Chiara; Pistocchi, Rossella

    2014-05-01

    The objective of the present study was to evaluate the nutrient removal efficiency and the physiological responses in terms of growth, biochemical composition and photosynthetic activity of the autochthonous freshwater algal strain Desmodesmus communis. Microalgae were grown in a primary municipal effluent under different hydraulic retention times (HRTs) and in a two-phases process using both primary and secondary wastewater effluents. Semi-continuous cultures were operated for 7 day at 5-, 3- and 1.5-day HRT and the different dilution rate showed a greater influence on the biomass composition and nutrient removal efficiency. Removal of N-NH3 and P-PO4 was over 99 % and the highest accumulation of polysaccharides (57.2 wt.%) was obtained at high HRT (5 day); the maximum content of proteins (26.9 wt.%) was achieved at 1.5-day HRT, even if, under this condition, a clear inefficiency in terms of ammonia removal was observed. Moreover the accumulation of N-NH3 occurring at 1.5-day HRT caused the decrease of the photosynthetic response in terms of efficiency of light capture (α) and relative electron transport rate (rETR), both parameters extracted from the rapid light curves (RLC) measurements. No significant differences were observed for the total fatty acids (TFAs), with a content of 2-3.5 wt.% for each HRT condition. On the other hand, in the two-phases process, when a nutrient deprivation condition was induced by diluting the culture with the secondary wastewater effluent, the algal cells accumulated TFAs, achieving a maximum content of 9.7 wt.% and a great increment in terms of biomass (1.64 ± 0.02 g L(-1)) due to the ability of this algal strain to accumulate intracellular N. The wide and accurate investigation of the different aspects related to the whole process represents a relevant point of novelty in this research field and suggests the operational conditions for the start-up of an open pond system for wastewater treatment and biomass

  14. Clocks in algae.

    PubMed

    Noordally, Zeenat B; Millar, Andrew J

    2015-01-20

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

  15. Origin of the algae.

    PubMed

    Perasso, R; Baroin, A; Qu, L H; Bachellerie, J P; Adoutte, A

    1989-05-11

    Eukaryotic algae are traditionally separated into three broad divisions: the rhodophytes, the chromophytes and the chlorophytes. The evolutionary relationships between these groups, their links with other eukaryotes and with other photosynthetic groups, such as euglenophytes and cryptophytes, have been the subject of much debate and speculation. Here we analyse partial sequences of the large (28S) cytoplasmic ribosomal RNA from ten new species of protists belonging to various groups of unicellular algae. By combining them with the homologous sequences from 14 other unicellular and multicellular eukaryotes, we show that rhodophytes, chromophytes and chlorophytes emerge as three distinct groups late among eukaryotes, that is, close to the metazoa-metaphytes radiation. This implies a relatively late occurrence of eukaryotic photosynthetic symbiosis. We also provide details of intra- and inter-phyla relationships.

  16. Genomics of Volvocine Algae

    PubMed Central

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

    2015-01-01

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

  17. Miocene Coralline algae

    SciTech Connect

    Bosence, D.W.J.

    1988-01-01

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

  18. Cellular Auxin Transport in Algae.

    PubMed

    Zhang, Suyun; van Duijn, Bert

    2014-01-01

    The phytohormone auxin is one of the main directors of plant growth and development. In higher plants, auxin is generated in apical plant parts and transported from cell-to-cell in a polar fashion. Auxin is present in all plant phyla, and the existence of polar auxin transport (PAT) is well established in land plants. Algae are a group of relatively simple, autotrophic, photosynthetic organisms that share many features with land plants. In particular, Charophyceae (a taxon of green algae) are closest ancestors of land plants. In the study of auxin function, transport and its evolution, the algae form an interesting research target. Recently, proof for polar auxin transport in Chara species was published and auxin related research in algae gained more attention. In this review we discuss auxin transport in algae with respect to land plants and suggest directions for future studies. PMID:27135491

  19. Cellular Auxin Transport in Algae.

    PubMed

    Zhang, Suyun; van Duijn, Bert

    2014-01-27

    The phytohormone auxin is one of the main directors of plant growth and development. In higher plants, auxin is generated in apical plant parts and transported from cell-to-cell in a polar fashion. Auxin is present in all plant phyla, and the existence of polar auxin transport (PAT) is well established in land plants. Algae are a group of relatively simple, autotrophic, photosynthetic organisms that share many features with land plants. In particular, Charophyceae (a taxon of green algae) are closest ancestors of land plants. In the study of auxin function, transport and its evolution, the algae form an interesting research target. Recently, proof for polar auxin transport in Chara species was published and auxin related research in algae gained more attention. In this review we discuss auxin transport in algae with respect to land plants and suggest directions for future studies.

  20. Ecology of Harmful Algae

    NASA Astrophysics Data System (ADS)

    Roelke, Daniel L.

    2007-07-01

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

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

    SciTech Connect

    2010-01-15

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

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

    PubMed

    Vadalà, M; Palmieri, B

    2015-01-01

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

  3. Transgenic algae engineered for higher performance

    SciTech Connect

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

    2014-10-21

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

  4. Algae fuel clean electricity generation

    SciTech Connect

    O'Sullivan, D.

    1993-02-08

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

  5. Hazard identification and risk characterization of bisphenols A, F and AF to aquatic organisms.

    PubMed

    Tišler, Tatjana; Krel, Alja; Gerželj, Urška; Erjavec, Boštjan; Dolenc, Marija Sollner; Pintar, Albin

    2016-05-01

    Production of bisphenol A (BPA) analogues such as bisphenol F (BPF) and bisphenol AF (BPAF) has recently increased, due to clear evidence of adverse effects of BPA on humans and wildlife. Bisphenols (BPs) have already been released into aquatic environment without previous available information about potential adverse effects of BPs and their potential risk to aquatic ecosystems. In this study, lethal and sublethal effects of BPF and BPAF to bacteria, algae, crustacea and fish embryos were investigated and the results were compared to the adverse effects obtained for BPA. We found that BPAF was the most toxic compound to Daphnia magna, Danio rerio and Desmodesmus subspicatus; the lowest 72 h EC50 (median effective concentration) and 21 d NOEC (no observed effect concentration) values were determined at 2.2 mg/L regarding zebrafish hatching success and 0.23 mg/L of BPAF obtained for growth and reproduction of water fleas, respectively. In most cases, BPA was more toxic to D. magna, D. rerio and D. subspicatus in comparison to BPF, but pigmentation of zebrafish embryos after 48 h of exposure and reproduction of water fleas after 21-day D. magna reproductive test exposure to BPF were much more impaired. Risk quotients (measured environmental concentration/21 d NOEC) showed that BPA, BPF and BPAF are recently not chronically hazardous to the survival, reproduction and growth of water fleas in surface waters. On the other hand, we importantly show that currently present BPAF concentrations in surface waters could cause a potential ecological risk to aquatic organisms. In the near future, higher concentrations of BPF and BPAF in surface waters are anticipated and for this reason further testing using test systems with various aquatic species and endpoints are needed to provide additional information about toxic impacts of BPF and BPAF on aquatic biota.

  6. Hazard identification and risk characterization of bisphenols A, F and AF to aquatic organisms.

    PubMed

    Tišler, Tatjana; Krel, Alja; Gerželj, Urška; Erjavec, Boštjan; Dolenc, Marija Sollner; Pintar, Albin

    2016-05-01

    Production of bisphenol A (BPA) analogues such as bisphenol F (BPF) and bisphenol AF (BPAF) has recently increased, due to clear evidence of adverse effects of BPA on humans and wildlife. Bisphenols (BPs) have already been released into aquatic environment without previous available information about potential adverse effects of BPs and their potential risk to aquatic ecosystems. In this study, lethal and sublethal effects of BPF and BPAF to bacteria, algae, crustacea and fish embryos were investigated and the results were compared to the adverse effects obtained for BPA. We found that BPAF was the most toxic compound to Daphnia magna, Danio rerio and Desmodesmus subspicatus; the lowest 72 h EC50 (median effective concentration) and 21 d NOEC (no observed effect concentration) values were determined at 2.2 mg/L regarding zebrafish hatching success and 0.23 mg/L of BPAF obtained for growth and reproduction of water fleas, respectively. In most cases, BPA was more toxic to D. magna, D. rerio and D. subspicatus in comparison to BPF, but pigmentation of zebrafish embryos after 48 h of exposure and reproduction of water fleas after 21-day D. magna reproductive test exposure to BPF were much more impaired. Risk quotients (measured environmental concentration/21 d NOEC) showed that BPA, BPF and BPAF are recently not chronically hazardous to the survival, reproduction and growth of water fleas in surface waters. On the other hand, we importantly show that currently present BPAF concentrations in surface waters could cause a potential ecological risk to aquatic organisms. In the near future, higher concentrations of BPF and BPAF in surface waters are anticipated and for this reason further testing using test systems with various aquatic species and endpoints are needed to provide additional information about toxic impacts of BPF and BPAF on aquatic biota. PMID:26957022

  7. Neuroprotective Effects of Marine Algae

    PubMed Central

    Pangestuti, Ratih; Kim, Se-Kwon

    2011-01-01

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

  8. Polysaccharides of the red algae.

    PubMed

    Usov, Anatolii I

    2011-01-01

    Red algae (Rhodophyta) are known as the source of unique sulfated galactans, such as agar, agarose, and carrageenans. The wide practical uses of these polysaccharides are based on their ability to form strong gels in aqueous solutions. Gelling polysaccharides usually have molecules built up of repeating disaccharide units with a regular distribution of sulfate groups, but most of the red algal species contain more complex galactans devoid of gelling ability because of various deviations from the regular structure. Moreover, several red algae may contain sulfated mannans or neutral xylans instead of sulfated galactans as the main structural polysaccharides. This chapter is devoted to a description of the structural diversity of polysaccharides found in the red algae, with special emphasis on the methods of structural analysis of sulfated galactans. In addition to the structural information, some data on the possible use of red algal polysaccharides as biologically active polymers or as taxonomic markers are briefly discussed.

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

    SciTech Connect

    Gharagozloo, Patricia E.; Drewry, Jessica Louise.

    2013-01-01

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

  10. Microscopic Gardens: A Close Look at Algae.

    ERIC Educational Resources Information Center

    Foote, Mary Ann

    1983-01-01

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

  11. 21 CFR 184.1120 - Brown algae.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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

  12. 21 CFR 184.1120 - Brown algae.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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

  13. 21 CFR 184.1120 - Brown algae.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

  14. 21 CFR 184.1120 - Brown algae.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  15. 21 CFR 184.1121 - Red algae.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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

  16. 21 CFR 184.1121 - Red algae.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  17. 21 CFR 184.1121 - Red algae.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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

  18. 21 CFR 184.1121 - Red algae.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

  19. 21 CFR 184.1121 - Red algae.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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

  20. 21 CFR 184.1120 - Brown algae.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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

  1. Biological importance of marine algae

    PubMed Central

    El Gamal, Ali A.

    2009-01-01

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

  2. Magnetite and Magnetotaxis in Algae

    PubMed Central

    de Araujo, F. F. Torres; Pires, M. A.; Frankel, R. B.; Bicudo, C. E. M.

    1986-01-01

    Magnetotactic algae of the genus Anisonema (Euglenophyceae) have been isolated from a coastal mangrove swamp in northeastern Brazil. The magnetotactic response is based on a permanent magnetic dipole moment per cell ∼7 10-10 emu. Each cell contains many magnetite (Fe3O4) particles organized in chains. ImagesFIGURE 2FIGURE 1FIGURE 3 PMID:19431684

  3. Algae. LC Science Tracer Bullet.

    ERIC Educational Resources Information Center

    Niskern, Diana, Comp.

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

  4. The remote sensing of algae

    NASA Technical Reports Server (NTRS)

    Thorne, J. F.

    1977-01-01

    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.

  5. Algae control for hydrogeneration canals

    SciTech Connect

    Grahovac, P.

    1997-02-16

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

  6. Parasites in algae mass culture

    PubMed Central

    Carney, Laura T.; Lane, Todd W.

    2014-01-01

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

  7. Halogenated Compounds from Marine Algae

    PubMed Central

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

    2010-01-01

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

  8. Stochastic Forecasting of Algae Blooms in Lakes

    SciTech Connect

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

    2013-01-15

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

  9. Cultivation of macroscopic marine algae

    SciTech Connect

    Ryther, J.H.

    1982-11-01

    The red alga Gracilaria tikvahiae may be grown outdoors year-round in central Florida with yields averaging 35.5 g dry wt/m/sup 2/.day, greater than the most productive terrestrial plants. This occurs only when the plants are in a suspended culture, with vigorous aeration and an exchange of 25 or more culture volumes of enriched seawater per day, which is not cost-effective. A culture system was designed in which Gracilaria, stocked at a density of 2 kg wet wt/m/sup 2/, grows to double its biomass in one to two weeks; it is then harvested to its starting density, and anaerobically digested to methane. The biomass is soaked for 6 hours in the digester residue, storing enough nutrients for two weeks' growth in unenriched seawater. The methane is combusted for energy and the waste gas is fed to the culture to provide mixing and CO/sub 2/, eliminating the need for aeration and seawater exchange. The green alga Ulva lactuca, unlike Gracilaria, uses bicarbonate as a photosynthesis carbon source, and can grow at high pH, with little or no free CO/sub 2/. It can therefore produce higher yields than Gracilaria in low water exchange conditions. It is also more efficiently converted to methane than is Gracilaria, but cannot tolerate Florida's summer temperatures so cannot be grown year-round. Attempts are being made to locate or produce a high-temperature tolerant strain.

  10. Hydrogen metabolism of photosynthetic bacteria and algae

    SciTech Connect

    Kumazawa, S.; Mitsui, A.

    1982-01-01

    The metabolism, metabolic pathways and biochemistry of hydrogen in photosynthetic bacteria and algae are reviewed. Detailed information on the occurrence and measurement of hydrogenase activity is presented. Hydrogen production rates for different species of algae and bacteria are presented. 173 references, 1 figure, 7 tables.

  11. SSMILes: Measuring the Nutrient Tolerance of Algae.

    ERIC Educational Resources Information Center

    Hedgepeth, David J.

    1995-01-01

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

  12. Take a Dip! Culturing Algae Is Easy.

    ERIC Educational Resources Information Center

    James, Daniel E.

    1983-01-01

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

  13. Nutritional And Taste Characteristics Of Algae

    NASA Technical Reports Server (NTRS)

    Karel, M.; Nakhost, Z.

    1992-01-01

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

  14. Effect of Dead Algae on Soil Permeability

    SciTech Connect

    Harvey, R.S.

    2003-02-21

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

  15. Antarctic sea ice thickness affects algae populations

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2013-01-01

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

  16. The ice nucleation activity of extremophilic algae.

    PubMed

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

    2013-01-01

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

  17. Composting of waste algae: a review.

    PubMed

    Han, Wei; Clarke, William; Pratt, Steven

    2014-07-01

    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.

  18. Flocculation of model algae under shear.

    SciTech Connect

    Pierce, Flint; Lechman, Jeremy B.

    2010-11-01

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

  19. Algae inhibition experiment and load characteristics of the algae solution

    NASA Astrophysics Data System (ADS)

    Xiong, L.; Gao, J. X.; Zhang, Y. X.; Yang, Z. K.; Zhang, D. Q.; He, W.

    2016-08-01

    It is necessary to inhibit microbial growth in an industrial cooling water system. This paper has developed a Monopolar/Bipolar polarity high voltage pulser with load adaptability for an algal experimental study. The load characteristics of the Chlorella pyrenoidosa solution were examined, and it was found that the solution load is resistive. The resistance is related to the plate area, concentration, and temperature of the solution. Furthermore, the pulser's treatment actually inhibits the algae cell growth. This article also explores the influence of various parameters of electric pulses on the algal effect. After the experiment, the optimum pulse parameters were determined to be an electric field intensity of 750 V/cm, a pulse width per second of 120μs, and monopolar polarity.

  20. Microbodies of the alga Chara.

    PubMed

    Stabenau, Helmut; Säftel, Werner; Winkler, Uwe

    2003-05-01

    Chara fragilis possesses microbodies with a remarkably large size of up to 2 micro m in diameter. Many of the organelles contain huge nucleoids of amorphous material or paracrystalline inclusions. After isolation of the organelles by gradient centrifugation the specific density of the microbodies was determined to be 1.25 g cm-3. Catalase, glycolate oxidase and hydroxypyruvate reductase as well as enzymes of the fatty acid beta-oxidation pathway were demonstrated to be constituents of the microbodies in Chara indicating that they are similar to those in green leaves. The data obtained are in agreement with the view that the Charophyceae and especially the algae in the subgroup of Charales are very closely related to the land plants.

  1. Algae biodiesel - a feasibility report

    PubMed Central

    2012-01-01

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

  2. Uptake and toxicity of hexafluoroarsenate in aquatic organisms.

    PubMed

    Daus, Birgit; Weiss, Holger; Altenburger, Rolf

    2010-01-01

    The arsenic species hexafluoroarsenate has been described as a contaminant of surface waters of anthropogenic origin. Here, we undertake to identify the most sensitive biological receptor among several sentinel aquatic species used in eco-toxicological assessment and to understand toxicity in terms of internal dose. Therefore, a screening of short-term effects using different aquatic organisms (bacterium Vibrio fischeri, fish Danio rerio, crustacean Daphnia magna and green alga Desmodesmus subspicatus and Scenedesmus vacuolatus) was conducted. For most organisms tested, effects were not detectable even at very high hexafluoroarsenate concentrations (up to 9.6mM) and thus the ecotoxic potential was found to be low in comparison to other arsenic compounds. The only organisms showing a clear response were the unicellular green alga, e.g. S. vacuolatus with an EC(50) value of 1.12 mM (84 mg L(-1) As). A linear relationship between ambient and internal concentration was found for this organism with a slope of 1.63 x 10(-3). Therefore, the internal concentration which shows a significant effect, e.g. 20% of inhibition of reproduction, was found to occur at a relatively low internal dose of 0.98 microM. Moreover, no biotransformation products inside the algae could be detected using arsenic speciation analysis with HPLC-ICP-MS, thus biological effects must be attributed to the untransformed compound. We conclude that the very low uptake observed for hexafluoroarsenate may be interpreted as preventive against toxic effects for the organisms.

  3. DGDG and Glycolipids in Plants and Algae.

    PubMed

    Kalisch, Barbara; Dörmann, Peter; Hölzl, Georg

    2016-01-01

    Photosynthetic organelles in plants and algae are characterized by the high abundance of glycolipids, including the galactolipids mono- and digalactosyldiacylglycerol (MGDG, DGDG) and the sulfolipid sulfoquinovosyldiacylglycerol (SQDG). Glycolipids are crucial to maintain an optimal efficiency of photosynthesis. During phosphate limitation, the amounts of DGDG and SQDG increase in the plastids of plants, and DGDG is exported to extraplastidial membranes to replace phospholipids. Algae often use betaine lipids as surrogate for phospholipids. Glucuronosyldiacylglycerol (GlcADG) is a further glycolipid that accumulates under phosphate deprived conditions. In contrast to plants, a number of eukaryotic algae contain very long chain polyunsaturated fatty acids of 20 or more carbon atoms in their glycolipids. The pathways and genes for galactolipid and sulfolipid synthesis are largely conserved between plants, Chlorophyta, Rhodophyta and algae with complex plastids derived from secondary or tertiary endosymbiosis. However, the relative contribution of the endoplasmic reticulum- and plastid-derived lipid pathways for glycolipid synthesis varies between plants and algae. The genes for glycolipid synthesis encode precursor proteins imported into the photosynthetic organelles. While most eukaryotic algae contain the plant-like galactolipid (MGD1, DGD1) and sulfolipid (SQD1, SQD2) synthases, the red alga Cyanidioschyzon harbors a cyanobacterium-type DGDG synthase (DgdA), and the amoeba Paulinella, derived from a more recent endosymbiosis event, contains cyanobacterium-type enzymes for MGDG and DGDG synthesis (MgdA, MgdE, DgdA). PMID:27023231

  4. Algae Biofuel in the Nigerian Energy Context

    NASA Astrophysics Data System (ADS)

    Elegbede, Isa; Guerrero, Cinthya

    2016-05-01

    The issue of energy consumption is one of the issues that have significantly become recognized as an important topic of global discourse. Fossil fuels production reportedly experiencing a gradual depletion in the oil-producing nations of the world. Most studies have relatively focused on biofuel development and adoption, however, the awareness of a prospect in the commercial cultivation of algae having potential to create economic boost in Nigeria, inspired this research. This study aims at exploring the potential of the commercialization of a different but commonly found organism, algae, in Nigeria. Here, parameters such as; water quality, light, carbon, average temperature required for the growth of algae, and additional beneficial nutrients found in algae were analysed. A comparative cum qualitative review of analysis was used as the study made use of empirical findings on the work as well as the author's deductions. The research explored the cultivation of algae with the two major seasonal differences (i.e. rainy and dry) in Nigeria as a backdrop. The results indicated that there was no significant difference in the contribution of algae and other sources of biofuels as a necessity for bioenergy in Nigeria. However, for an effective sustainability of this prospect, adequate measures need to be put in place in form of funding, provision of an economically-enabling environment for the cultivation process as well as proper healthcare service in the face of possible health hazard from technological processes. Further studies can seek to expand on the potential of cultivating algae in the Harmattan season.

  5. DGDG and Glycolipids in Plants and Algae.

    PubMed

    Kalisch, Barbara; Dörmann, Peter; Hölzl, Georg

    2016-01-01

    Photosynthetic organelles in plants and algae are characterized by the high abundance of glycolipids, including the galactolipids mono- and digalactosyldiacylglycerol (MGDG, DGDG) and the sulfolipid sulfoquinovosyldiacylglycerol (SQDG). Glycolipids are crucial to maintain an optimal efficiency of photosynthesis. During phosphate limitation, the amounts of DGDG and SQDG increase in the plastids of plants, and DGDG is exported to extraplastidial membranes to replace phospholipids. Algae often use betaine lipids as surrogate for phospholipids. Glucuronosyldiacylglycerol (GlcADG) is a further glycolipid that accumulates under phosphate deprived conditions. In contrast to plants, a number of eukaryotic algae contain very long chain polyunsaturated fatty acids of 20 or more carbon atoms in their glycolipids. The pathways and genes for galactolipid and sulfolipid synthesis are largely conserved between plants, Chlorophyta, Rhodophyta and algae with complex plastids derived from secondary or tertiary endosymbiosis. However, the relative contribution of the endoplasmic reticulum- and plastid-derived lipid pathways for glycolipid synthesis varies between plants and algae. The genes for glycolipid synthesis encode precursor proteins imported into the photosynthetic organelles. While most eukaryotic algae contain the plant-like galactolipid (MGD1, DGD1) and sulfolipid (SQD1, SQD2) synthases, the red alga Cyanidioschyzon harbors a cyanobacterium-type DGDG synthase (DgdA), and the amoeba Paulinella, derived from a more recent endosymbiosis event, contains cyanobacterium-type enzymes for MGDG and DGDG synthesis (MgdA, MgdE, DgdA).

  6. Errors When Extracting Oil from Algae

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  7. Method and apparatus for processing algae

    SciTech Connect

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

    2012-07-03

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

  8. 21 CFR 73.275 - Dried algae meal.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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

  9. 21 CFR 73.275 - Dried algae meal.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

  10. 21 CFR 73.275 - Dried algae meal.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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

  11. 21 CFR 73.275 - Dried algae meal.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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

  12. 21 CFR 73.275 - Dried algae meal.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Dried algae meal. 73.275 Section 73.275 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.275 Dried algae meal. (a) Identity. The color additive dried algae meal is a dried mixture of algae cells (genus Spongiococcum, separated from its culture...

  13. Pyogenic Flexor Tenosynovitis Caused by Shewanella algae.

    PubMed

    Fluke, Erin C; Carayannopoulos, Nikoletta L; Lindsey, Ronald W

    2016-07-01

    Pyogenic flexor tenosynovitis is an orthopedic emergency most commonly caused by Staphylococcus aureus and streptococci and occasionally, when associated with water exposure, Mycobacterium marinum. Shewanella algae, a gram-negative bacillus found in warm saltwater environments, has infrequently been reported to cause serious soft tissue infections and necrosis. In this case, S. algae caused complicated flexor tenosynovitis requiring open surgical irrigation and debridement. Flexor tenosynovitis caused by S. algae rapidly presented with all 4 Kanavel cardinal signs as well as subcutaneous purulence, ischemia, and necrosis, thus meeting the requirements for Pang et al group III classification of worst prognosis. Because of its rarity and virulence, S. algae should always be considered in cases of flexor tenosynovitis associated with traumatic water exposure to treat and minimize morbidity appropriately.

  14. 2011 Biomass Program Platform Peer Review: Algae

    SciTech Connect

    Yang, Joyce

    2012-02-01

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

  15. Collection, Isolation and Culture of Marine Algae.

    ERIC Educational Resources Information Center

    James, Daniel E.

    1984-01-01

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

  16. Stochastic Forecasting of Algae Blooms in Lakes

    SciTech Connect

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

    2013-01-03

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

  17. Antioxidant Activity of Hawaiian Marine Algae

    PubMed Central

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

    2012-01-01

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

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

    PubMed

    Takaichi, Shinichi

    2011-01-01

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

  19. Biogas production experimental research using algae.

    PubMed

    Baltrėnas, Pranas; Misevičius, Antonas

    2015-01-01

    The current study is on the the use of macro-algae as feedstock for biogas production. Three types of macro-algae, Cladophora glomerata (CG), Chara fragilis (CF), and Spirogyra neglecta (SN), were chosen for this research. The experimental studies on biogas production were carried out with these algae in a batch bioreactor. In the bioreactor was maintained 35 ± 1°C temperature. The results showed that the most appropriate macro-algae for biogas production are Spirogyra neglecta (SN) and Cladophora glomerata (CG). The average amount of biogas obtained from the processing of SN - 0.23 m(3)/m(3)d, CG - 0.20 m(3)/m(3)d, and CF - 0.12 m(3)/m(3)d. Considering the concentration of methane obtained during the processing of SN and CG, which after eight days and until the end of the experiment exceeded 60%, it can be claimed that biogas produced using these algae is valuable. When processing CF, the concentration of methane reached the level of 50% only by the final day of the experiment, which indicates that this alga is less suitable for biogas production.

  20. SCALE FORMATION IN CHRYSOPHYCEAN ALGAE

    PubMed Central

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

    1970-01-01

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

  1. Hyperspectral imaging of snow algae and green algae from aeroterrestrial habitats

    PubMed Central

    Holzinger, Andreas; Allen, Michael C.; Deheyn, Dimitri D.

    2016-01-01

    Snow algae and green algae living in aeroterrestrial habitats are ideal obbjects to study adaptation to high light irradiation. Here, we used a detailed description of the spectral properties as a proxy for photo-acclimation/protection in snow algae (Chlamydomonas nivalis, Chlainomonas sp. and Chloromonas sp.) and charopyhte green algae (Zygnema sp., Zygogonium ericetorum and Klebsormidium crenulatum). The hyperspectral microscopic mapping and imaging technique allowed us to acquire total absorbance spectra of these microalgae in the waveband of 400-900 nm. Particularly in Chlamydomonas nivalis and Chlainomonas sp., a high absorbance in the wave band of 400-550 nm was observed, due to naturally occurring secondary carotenoids; in Chloromonas sp. and in the charopyhte algae this was missing, the latter being close relatives to land plants. To investigate if cellular water loss has an influence on the spectral properties, the cells were plasmolysed in sorbitol or desiccated at ambient air. While in snow algae, these treatments did not change the spectral properties, in the charopyhte algae the condensation of the cytoplasm and plastids increased the absorbance in the lower waveband of 400 – 500 nm. These changes might be ecologically relevant and photoprotective, as aeroterrestrial algae are naturally exposed to occasional water limitation, leading to desiccation, which are conditions usually occurring together with higher irradiation. PMID:27442511

  2. Hyperspectral imaging of snow algae and green algae from aeroterrestrial habitats.

    PubMed

    Holzinger, Andreas; Allen, Michael C; Deheyn, Dimitri D

    2016-09-01

    Snow algae and green algae living in aeroterrestrial habitats are ideal objects to study adaptation to high light irradiation. Here, we used a detailed description of the spectral properties as a proxy for photo-acclimation/protection in snow algae (Chlamydomonas nivalis, Chlainomonas sp. and Chloromonas sp.) and charophyte green algae (Zygnema sp., Zygogonium ericetorum and Klebsormidium crenulatum). The hyperspectral microscopic mapping and imaging technique allowed us to acquire total absorption spectra of these microalgae in the waveband of 400-900nm. Particularly in Chlamydomonas nivalis and Chlainomonas sp., a high absorbance between 400-550nm was observed, due to naturally occurring secondary carotenoids; in Chloromonas sp. and in the charopyhte algae this high absorbance was missing, the latter being close relatives to land plants. To investigate if cellular water loss has an influence on the spectral properties, the cells were plasmolysed in sorbitol or desiccated at ambient air. While in snow algae, these treatments did hardly change the spectral properties, in the charopyhte algae the condensation of the cytoplasm and plastids increased the absorbance in the lower waveband of 400-500nm. These changes might be ecologically relevant and photoprotective, as aeroterrestrial algae are naturally exposed to occasional water limitation, leading to desiccation, which are conditions usually occurring together with higher irradiation. PMID:27442511

  3. Hyperspectral imaging of snow algae and green algae from aeroterrestrial habitats.

    PubMed

    Holzinger, Andreas; Allen, Michael C; Deheyn, Dimitri D

    2016-09-01

    Snow algae and green algae living in aeroterrestrial habitats are ideal objects to study adaptation to high light irradiation. Here, we used a detailed description of the spectral properties as a proxy for photo-acclimation/protection in snow algae (Chlamydomonas nivalis, Chlainomonas sp. and Chloromonas sp.) and charophyte green algae (Zygnema sp., Zygogonium ericetorum and Klebsormidium crenulatum). The hyperspectral microscopic mapping and imaging technique allowed us to acquire total absorption spectra of these microalgae in the waveband of 400-900nm. Particularly in Chlamydomonas nivalis and Chlainomonas sp., a high absorbance between 400-550nm was observed, due to naturally occurring secondary carotenoids; in Chloromonas sp. and in the charopyhte algae this high absorbance was missing, the latter being close relatives to land plants. To investigate if cellular water loss has an influence on the spectral properties, the cells were plasmolysed in sorbitol or desiccated at ambient air. While in snow algae, these treatments did hardly change the spectral properties, in the charopyhte algae the condensation of the cytoplasm and plastids increased the absorbance in the lower waveband of 400-500nm. These changes might be ecologically relevant and photoprotective, as aeroterrestrial algae are naturally exposed to occasional water limitation, leading to desiccation, which are conditions usually occurring together with higher irradiation.

  4. PPR proteins of green algae.

    PubMed

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

    2013-01-01

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

  5. PPR proteins of green algae

    PubMed Central

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

    2013-01-01

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

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

    PubMed

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

    2009-07-15

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

  7. Biological toxicity of lanthanide elements on algae.

    PubMed

    Tai, Peidong; Zhao, Qing; Su, Dan; Li, Peijun; Stagnitti, Frank

    2010-08-01

    The biological toxicity of lanthanides on marine monocellular algae was investigated. The specific objective of this research was to establish the relationship between the abundance in the seawater of lanthanides and their biological toxicities on marine monocellular algae. The results showed that all single lanthanides had similar toxic effects on Skeletonema costatum. High concentrations of lanthanides (29.04+/-0.61 micromol L(-1)) resulted in 50% reduction in growth of algae compared to the controls (0 micromol L(-1)) after 96 h (96 h-EC50). The biological toxicity of 13 lanthanides on marine monocellular algae was unrelated with the abundance of different lanthanide elements in nature, and the "Harkins rule" was not appropriate for the lanthanides. A mixed solution that contained equivalent concentrations of each lanthanide element had the same inhibition effect on algae cells as each individual lanthanide element at the same total concentration. This phenomenon is unique compared to the groups of other elements in the periodic table. Hence, we speculate that the monocellular organisms might not be able to sufficiently differentiate between the almost chemically identical lanthanide elements.

  8. Studies on marine algae for haemagglutinic activity.

    PubMed

    Alam, M T; Usmanghani, K

    1994-07-01

    Lectins (agglutinins) are important in medical and immunological applications. Phytohaemagglutinins have been found useful in blood banking. Keeping in view of these facts, the marine algae found at Karachi coastal region have been screened for agglutinic activity by using human erythrocytes of A, B, AB and 0 group. Altogether 53 algal samples were collected and subjected to extraction, fractionation serial dilution and titre determinations. The total marine algae screened for haemagglutinic activity were 44 out of these 14, 13 and 17 belonged to Chlorophyta, Phaeophyta, and Rhodophyta respectively. Among these three groups the Rhodophyta showed the highest number of lytic activity. The green marine alga Valoniopsis pachynema showed a titre value between 2(2) and 2(3), which is statistically significant. In case of brown marine algae Colpomenia sinuosa was found to be active (titre 2(3)), while Dictyota dichotoma, D. indica and Iyengaria stellata, furnished week titre value as 2(2). The red marine algae screened were 17, out of these 4 spp. showed significant activity (titre 2(3)), and these are Gelidium usmanghani, Gracilaria foliifera Hypnea pannosa and Hynea valentiae. While Scinaia fascicularis, Scinaia indica and Champia parvula were found to be weak in their onset on human erythrocytes. The results obtained were quite in agreement with those reported in the literature. PMID:16414751

  9. Biological toxicity of lanthanide elements on algae.

    PubMed

    Tai, Peidong; Zhao, Qing; Su, Dan; Li, Peijun; Stagnitti, Frank

    2010-08-01

    The biological toxicity of lanthanides on marine monocellular algae was investigated. The specific objective of this research was to establish the relationship between the abundance in the seawater of lanthanides and their biological toxicities on marine monocellular algae. The results showed that all single lanthanides had similar toxic effects on Skeletonema costatum. High concentrations of lanthanides (29.04+/-0.61 micromol L(-1)) resulted in 50% reduction in growth of algae compared to the controls (0 micromol L(-1)) after 96 h (96 h-EC50). The biological toxicity of 13 lanthanides on marine monocellular algae was unrelated with the abundance of different lanthanide elements in nature, and the "Harkins rule" was not appropriate for the lanthanides. A mixed solution that contained equivalent concentrations of each lanthanide element had the same inhibition effect on algae cells as each individual lanthanide element at the same total concentration. This phenomenon is unique compared to the groups of other elements in the periodic table. Hence, we speculate that the monocellular organisms might not be able to sufficiently differentiate between the almost chemically identical lanthanide elements. PMID:20547408

  10. Controlled regular locomotion of algae cell microrobots.

    PubMed

    Xie, Shuangxi; Jiao, Niandong; Tung, Steve; Liu, Lianqing

    2016-06-01

    Algae cells can be considered as microrobots from the perspective of engineering. These organisms not only have a strong reproductive ability but can also sense the environment, harvest energy from the surroundings, and swim very efficiently, accommodating all these functions in a body of size on the order of dozens of micrometers. An interesting topic with respect to random swimming motions of algae cells in a liquid is how to precisely control them as microrobots such that they swim according to manually set routes. This study developed an ingenious method to steer swimming cells based on the phototaxis. The method used a varying light signal to direct the motion of the cells. The swimming trajectory, speed, and force of algae cells were analyzed in detail. Then the algae cell could be controlled to swim back and forth, and traverse a crossroad as a microrobot obeying specific traffic rules. Furthermore, their motions along arbitrarily set trajectories such as zigzag, and triangle were realized successfully under optical control. Robotize algae cells can be used to precisely transport and deliver cargo such as drug particles in microfluidic chip for biomedical treatment and pharmacodynamic analysis. The study findings are expected to bring significant breakthrough in biological drives and new biomedical applications.

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

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

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

  12. Genome of the red alga Porphyridium purpureum.

    PubMed

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

    2013-01-01

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

  13. Algae control problems and practices workshop

    SciTech Connect

    Pryfogle, P.A.; Ghio, G.

    1996-09-01

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

  14. Genome of the red alga Porphyridium purpureum

    PubMed Central

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

    2013-01-01

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

  15. Turning Algae into Energy in New Mexico

    ScienceCinema

    Sayre, Richard; Olivares, Jose; Lammers, Peter

    2016-07-12

    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.

  16. Turning Algae into Energy in New Mexico

    SciTech Connect

    Sayre, Richard; Olivares, Jose; Lammers, Peter

    2013-07-29

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

  17. Microspectroscopy of the photosynthetic compartment of algae.

    PubMed

    Evangelista, Valtere; Frassanito, Anna Maria; Passarelli, Vincenzo; Barsanti, Laura; Gualtieri, Paolo

    2006-01-01

    We performed microspectroscopic evaluation of the pigment composition of the photosynthetic compartments of algae belonging to different taxonomic divisions and higher plants. The feasibility of microspectroscopy for discriminating among species and/or phylogenetic groups was tested on laboratory cultures. Gaussian bands decompositions and a fitting algorithm, together with fourth-derivative transformation of absorbance spectra, provided a reliable discrimination among chlorophylls a, b and c, phycobiliproteins and carotenoids. Comparative analysis of absorption spectra highlighted the evolutionary grouping of the algae into three main lineages in accordance with the most recent endosymbiotic theories.

  18. 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...

  19. MANOMETRIC MEASUREMENTS OF PHOTOSYNTHESIS IN THE MARINE ALGA GIGARTINA

    PubMed Central

    Emerson, Robert; Green, Lowell

    1934-01-01

    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

  20. 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)...

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

    PubMed

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

    1985-01-01

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

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

    PubMed

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

    1985-01-01

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

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

    ERIC Educational Resources Information Center

    Porter, Lee A.

    1985-01-01

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

  4. Neonatal sepsis caused by Shewanella algae: A case report.

    PubMed

    Charles, Marie Victor Pravin; Srirangaraj, Sreenivasan; Kali, Arunava

    2015-01-01

    Sepsis remains a leading cause of mortality among neonates, especially in developing countries. Most cases of neonatal sepsis are attributed to Escherichia coli and other members of the Enterobacteriaceae family. Shewanella algae (S. algae) is a gram-negative saprophytic bacillus, commonly associated with the marine environment, which has been isolated from humans. Early onset neonatal sepsis caused by S. algae is uncommon. We report a case of S. algae blood stream infection in a newborn with early onset neonatal sepsis.

  5. 21 CFR 73.185 - Haematococcus algae meal.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Haematococcus algae meal. 73.185 Section 73.185... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.185 Haematococcus algae meal. (a) Identity. (1) The color additive haematococcus algae meal consists of the comminuted and dried cells of the...

  6. 21 CFR 73.185 - Haematococcus algae meal.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Haematococcus algae meal. 73.185 Section 73.185... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.185 Haematococcus algae meal. (a) Identity. (1) The color additive haematococcus algae meal consists of the comminuted and dried cells of the...

  7. 21 CFR 73.185 - Haematococcus algae meal.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Haematococcus algae meal. 73.185 Section 73.185... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.185 Haematococcus algae meal. (a) Identity. (1) The color additive haematococcus algae meal consists of the comminuted and dried cells of the...

  8. 21 CFR 73.185 - Haematococcus algae meal.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Haematococcus algae meal. 73.185 Section 73.185... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.185 Haematococcus algae meal. (a) Identity. (1) The color additive haematococcus algae meal consists of the comminuted and dried cells of the...

  9. 21 CFR 73.185 - Haematococcus algae meal.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Haematococcus algae meal. 73.185 Section 73.185... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.185 Haematococcus algae meal. (a) Identity. (1) The color additive haematococcus algae meal consists of the comminuted and dried cells of the...

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

    ERIC Educational Resources Information Center

    Applied Biochemists, Inc., Mequon, WI.

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

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

    PubMed

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

    2015-03-01

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

  12. Spirulina: The Alga That Can End Malnutrition.

    ERIC Educational Resources Information Center

    Fox, Ripley D.

    1985-01-01

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

  13. Fucoidans — sulfated polysaccharides of brown algae

    NASA Astrophysics Data System (ADS)

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

    2009-08-01

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

  14. Pheromone signaling during sexual reproduction in algae.

    PubMed

    Frenkel, Johannes; Vyverman, Wim; Pohnert, Georg

    2014-08-01

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

  15. Laser-fluorescence measurement of marine algae

    NASA Technical Reports Server (NTRS)

    Browell, E. V.

    1980-01-01

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

  16. Peroxisomal targeting signals in green algae.

    PubMed

    Shinozaki, Akiko; Sato, Nagisa; Hayashi, Yasuko

    2009-03-01

    Peroxisomal enzymatic proteins contain targeting signals (PTS) to enable their import into peroxisomes. These targeting signals have been identified as PTS1 and PTS2 in mammalian, yeast, and higher plant cells; however, no PTS2-like amino acid sequences have been observed in enzymes from the genome database of Cyanidiochyzon merolae (Bangiophyceae), a primitive red algae. In studies on the evolution of PTS, it is important to know when their sequences came to be the peroxisomal targeting signals for all living organisms. To this end, we identified a number of genes in the genome database of the green algae Chlamydomonas reinhardtii, which contains amino acid sequences similar to those found in plant PTS. In order to determine whether these sequences function as PTS in green algae, we expressed modified green fluorescent proteins (GFP) fused to these putative PTS peptides under the cauliflower mosaic virus 35S promoter. To confirm whether granular structures containing GFP-PTS fusion proteins accumulated in the peroxisomes of Closterium ehrenbergii, we observed these cells after the peroxisomes were stained with 3, 3'-diaminobenzidine. Our results confirm that the GFP-PTS fusion proteins indeed accumulated in the peroxisomes of these green algae. These findings suggest that the peroxisomal transport system for PTS1 and PTS2 is conserved in green algal cells and that our fusion proteins can be used to visualize peroxisomes in live cells.

  17. Widespread occurrence of norspermidine and norspermine in eukaryotic algae.

    PubMed

    Hamana, K; Matsuzaki, S

    1982-04-01

    Seven phyla of eukaryotic algae were analyzed to determine their contents of diamines and polyamines. The algae examined included Rhodophyta, Pyrrophyta, Chrysophyta, Phaeophyta, Euglenophyta, Chlorophyta, and Charophyta. Both putrescine and spermidine were detected in all the algae studied, while appreciable amounts of spermine were detected only in a few species of algae. 1,3-Diaminopropane, norspermidine, and norspermine, which are chemical analogs of putrescine, spermidine, and spermine, respectively, were widely distributed in various species of algae. There was no parallelism between the distribution patterns of putrescine derivatives and those of 1,3-diaminopropane derivatives. Cadaverine and agmatine were detected in multicellular marine algae. Homospermidine was detected sporadically in some algae. The biological and phylogenetical significance of polyamines in these lower eukaryotes is discussed.

  18. Sulfated polysaccharides as bioactive agents from marine algae.

    PubMed

    Ngo, Dai-Hung; Kim, Se-Kwon

    2013-11-01

    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.

  19. Photooxidative Death in Blue-Green Algae

    PubMed Central

    Abeliovich, A.; Shilo, M.

    1972-01-01

    When incubated in the light under 100% oxygen, wild-type blue-green algae (Anacystis nidulans, Synechococcus cedrorum) die out rapidly at temperatures of 4 to 15 C, and at 35 C (or at 26 C in the case of S. cedrorum) in the absence of CO2. Photosynthesis is impaired in these cells long before they die. Blocking of photosystem II at high temperatures in the presence of CO2 sensitizes the algae to photooxidative death. Photooxidative death and bleaching of photosynthetic pigments are separable phenomena. Photooxidative conditions were demonstrated in Israeli fish ponds using A. nidulans as the test organism during dense summer blooms, when dissolved CO2 is low, and in winter, when water temperatures generally drop below 15 C. This finding suggests that photooxidative death may be responsible for the sudden decomposition of blue-green blooms in summer, and may be a factor in the absence of blue-green blooms in winter. PMID:4626540

  20. Phycobilisomes in Blue-Green Algae

    PubMed Central

    Wildman, Ruth B.; Bowen, C. C.

    1974-01-01

    Fifteen species of freshwater blue-green algae, including unicellular, filamentous, and colonial forms, were subjected to a variety of fixatives, fixation conditions, and stains for comparison of the preservation of phycobilisomes. Absorption spectra of the corresponding in vivo and released photosynthetic pigments, in 10 of the species that were maintained in culture, demonstrated the presence of phycocyanin in all 10 species and phycoerythrin in only 2 of them. Spectroscope and electron microscope evidence was obtained for localization of phycobiliproteins in phycobilisomes of Nostoc muscorum. Phycobilisomes were observed in all species examined in situ, strenghening the hypothesis that phycobilisomes are common to all phycobiliprotein-containing photosynthetic blue-green algae. Images PMID:4204443

  1. Toxicity of chlorinated benzenes to marine algae

    NASA Astrophysics Data System (ADS)

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

    1997-12-01

    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.

  2. Bioconcentration of tetrachlorobenzene in marine algae

    NASA Astrophysics Data System (ADS)

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

    1997-09-01

    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).

  3. Biofuels from algae: challenges and potential

    PubMed Central

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

    2011-01-01

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

  4. Nitrogenous wastewater treatment by activated algae

    SciTech Connect

    Gupta, S.K.

    1985-02-01

    A biological treatability study by activated algae process was performed with synthetic wastewater containing a high concentration of nitrogen. It was found that the wastewater could be processed at all nitrogen removal rates. The yield coefficient and decay coefficient for heterotrophic bacteria were 0.06 (COD basis) and 0.019 day/sup -1/ (COD bases) respectively. The yield coefficient and decay coefficient for nitrifiers were 0.06 and 0.02 day/sup -1/ respectively. NH/sup +//sub 4/-N seemed to inhibit bacteriological growth as the yield coefficients values were significantly lower. Nitrification was observed at all the nitrogen loadings. Diffusion of NH/sub 3/ into the atmosphere was the dominant mechanism of nitrogen removal. The results demonstrated a symbiotic relationship between algae and bacteria.

  5. Fermentation metabolism and its evolution in algae

    PubMed Central

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

    2013-01-01

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

  6. Selenium Uptake and Volatilization by Marine Algae

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  7. Fermentation metabolism and its evolution in algae.

    PubMed

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

    2013-01-01

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

  8. Algae-Derived Dietary Ingredients Nourish Animals

    NASA Technical Reports Server (NTRS)

    2015-01-01

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

  9. Antibody Production in Plants and Green Algae.

    PubMed

    Yusibov, Vidadi; Kushnir, Natasha; Streatfield, Stephen J

    2016-04-29

    Monoclonal antibodies (mAbs) have a wide range of modern applications, including research, diagnostic, therapeutic, and industrial uses. Market demand for mAbs is high and continues to grow. Although mammalian systems, which currently dominate the biomanufacturing industry, produce effective and safe recombinant mAbs, they have a limited manufacturing capacity and high costs. Bacteria, yeast, and insect cell systems are highly scalable and cost effective but vary in their ability to produce appropriate posttranslationally modified mAbs. Plants and green algae are emerging as promising production platforms because of their time and cost efficiencies, scalability, lack of mammalian pathogens, and eukaryotic posttranslational protein modification machinery. So far, plant- and algae-derived mAbs have been produced predominantly as candidate therapeutics for infectious diseases and cancer. These candidates have been extensively evaluated in animal models, and some have shown efficacy in clinical trials. Here, we review ongoing efforts to advance the production of mAbs in plants and algae. PMID:26905655

  10. Antibody Production in Plants and Green Algae.

    PubMed

    Yusibov, Vidadi; Kushnir, Natasha; Streatfield, Stephen J

    2016-04-29

    Monoclonal antibodies (mAbs) have a wide range of modern applications, including research, diagnostic, therapeutic, and industrial uses. Market demand for mAbs is high and continues to grow. Although mammalian systems, which currently dominate the biomanufacturing industry, produce effective and safe recombinant mAbs, they have a limited manufacturing capacity and high costs. Bacteria, yeast, and insect cell systems are highly scalable and cost effective but vary in their ability to produce appropriate posttranslationally modified mAbs. Plants and green algae are emerging as promising production platforms because of their time and cost efficiencies, scalability, lack of mammalian pathogens, and eukaryotic posttranslational protein modification machinery. So far, plant- and algae-derived mAbs have been produced predominantly as candidate therapeutics for infectious diseases and cancer. These candidates have been extensively evaluated in animal models, and some have shown efficacy in clinical trials. Here, we review ongoing efforts to advance the production of mAbs in plants and algae.

  11. New records of marine algae in Vietnam

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

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

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

    PubMed

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

    2010-03-01

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

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

    PubMed

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

    2010-05-15

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

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

    PubMed

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

    2010-05-15

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

  15. Electrochemical oxidation of fluoroquinolone antibiotics: Mechanism, residual antibacterial activity and toxicity change.

    PubMed

    Zhu, Linyan; Santiago-Schübel, Beatrix; Xiao, Hongxia; Hollert, Henner; Kueppers, Stephan

    2016-10-01

    In this paper, we studied the electrochemical oxidation mechanisms of three typical fluoroquinolone antibiotics (FQs), and investigated residual antibacterial activity and toxicity changes after oxidation processes. Electrochemistry coupled to mass spectrometry (EC-MS) was used to study the oxidation processes of ciprofloxacin (CIP), norfloxacin (NOR) and ofloxacin (OFL). Eight oxidation products for each parent compound were identified and their chemical structures were elucidated. The transformation trend of each product, with the continuous increase of voltage from 0 to 3000 mV, was recorded by online EC-MS. The oxidation pathways were proposed based on the structural information and transformation trends of oxidation products. We found the oxidation mechanisms of FQs consisted of the hydroxylation and cleavage of piperazinyl ring via reactions with hydroxyl radicals, while the fluoroquinolone core remained intact. The antibacterial activity of the parent compounds and their oxidation mixtures was estimated using zone inhibition tests for gram-negative bacteria Salmonella typhimurium. It was found that the oxidation mixtures of CIP and NOR retained the antibacterial properties with lower activity compared to their parent compounds, while the antibacterial activity of OFL was almost eliminated after oxidation. Furthermore, the toxicity of the three FQs and their oxidation mixtures were evaluated using algal growth inhibition test (Desmodesmus subspicatus). The median effective concentration (EC50) values for the algal inhibition tests were calculated for the end point of growth rate. The toxicity of CIP and NOR to green algae after electrochemical oxidation, remained unchanged, while that of OFL significantly increased. The results presented in this paper contribute to an understanding of the electrochemical oxidation mechanisms of FQs, and highlight the potential environmental risks of FQs after electrochemical oxidation processes.

  16. Electrochemical oxidation of fluoroquinolone antibiotics: Mechanism, residual antibacterial activity and toxicity change.

    PubMed

    Zhu, Linyan; Santiago-Schübel, Beatrix; Xiao, Hongxia; Hollert, Henner; Kueppers, Stephan

    2016-10-01

    In this paper, we studied the electrochemical oxidation mechanisms of three typical fluoroquinolone antibiotics (FQs), and investigated residual antibacterial activity and toxicity changes after oxidation processes. Electrochemistry coupled to mass spectrometry (EC-MS) was used to study the oxidation processes of ciprofloxacin (CIP), norfloxacin (NOR) and ofloxacin (OFL). Eight oxidation products for each parent compound were identified and their chemical structures were elucidated. The transformation trend of each product, with the continuous increase of voltage from 0 to 3000 mV, was recorded by online EC-MS. The oxidation pathways were proposed based on the structural information and transformation trends of oxidation products. We found the oxidation mechanisms of FQs consisted of the hydroxylation and cleavage of piperazinyl ring via reactions with hydroxyl radicals, while the fluoroquinolone core remained intact. The antibacterial activity of the parent compounds and their oxidation mixtures was estimated using zone inhibition tests for gram-negative bacteria Salmonella typhimurium. It was found that the oxidation mixtures of CIP and NOR retained the antibacterial properties with lower activity compared to their parent compounds, while the antibacterial activity of OFL was almost eliminated after oxidation. Furthermore, the toxicity of the three FQs and their oxidation mixtures were evaluated using algal growth inhibition test (Desmodesmus subspicatus). The median effective concentration (EC50) values for the algal inhibition tests were calculated for the end point of growth rate. The toxicity of CIP and NOR to green algae after electrochemical oxidation, remained unchanged, while that of OFL significantly increased. The results presented in this paper contribute to an understanding of the electrochemical oxidation mechanisms of FQs, and highlight the potential environmental risks of FQs after electrochemical oxidation processes. PMID:27318447

  17. Aquatic toxicity of the macrolide antibiotic clarithromycin and its metabolites.

    PubMed

    Baumann, Michaela; Weiss, Klaus; Maletzki, Dirk; Schüssler, Walter; Schudoma, Dieter; Kopf, Willi; Kühnen, Ute

    2015-02-01

    The human macrolide antibiotic clarithromycin is widespread in surface waters. Our study shows that its major metabolite 14-hydroxy(R)-clarithromycin is found in surface waters in comparable amounts. This metabolite is known to be pharmacologically active. Additionally, clarithromycin is partly metabolised to N-desmethyl-clarithromycin, which has no antimicrobial activity. For clarithromycin, some ecotoxicological studies on aquatic organisms have been published. However, many of them are not conform with the scientific principles as given in the "Technical guidance for deriving environmental quality standards" (TGD-EQS), because numerous studies were poorly documented and the methods did not contain analytical measurements confirming that the exposure concentrations were in the range of ± 20% of the nominal concentrations. Ecotoxicological effects of clarithromycin and its two metabolites on the zebrafish Danio rerio (embryo test), the microcrustacean Daphnia magna, the aquatic monocotyledonous macrophyte Lemna minor, the freshwater green alga Desmodesmus subspicatus (Chlorophyta) and the cyanobacterium Anabaena flosaquae were investigated in compliance with the TGD-EQS. Environmental risk assessment was performed using ErC10 values of Anabaena, the species most sensitive to clarithromycin and 14-hydroxy(R)-clarithromycin in our testing. Based oncomparable toxicity and similar concentrations of clarithromycin and its active metabolite 14-hydroxy(R)-clarithromycin in surface waters, an additional multiplication factor of 2 to the assessment factor of 10 on the ErC10 of clarithromycin should be used. Consequently, a freshwater quality standard of 0.130 μg L(-1) is proposed for clarithromycin as the "lead substance". Taking this additional multiplication factor of 2 into account, single monitoring of clarithromycin may be sufficient, in order to reduce the number of substances listed for routine monitoring programs. PMID:25051235

  18. Hydrogenases in green algae: do they save the algae's life and solve our energy problems?

    PubMed

    Happe, Thomas; Hemschemeier, Anja; Winkler, Martin; Kaminski, Annette

    2002-06-01

    Green algae are the only known eukaryotes with both oxygenic photosynthesis and a hydrogen metabolism. Recent physiological and genetic discoveries indicate a close connection between these metabolic pathways. The anaerobically inducible hydA genes of algae encode a special type of highly active [Fe]-hydrogenase. Electrons from reducing equivalents generated during fermentation enter the photosynthetic electron transport chain via the plastoquinone pool. They are transferred to the hydrogenase by photosystem I and ferredoxin. Thus, the [Fe]-hydrogenase is an electron 'valve' that enables the algae to survive under anaerobic conditions. During sulfur deprivation, illuminated algal cultures evolve large quantities of hydrogen gas, and this promises to be an alternative future energy source. PMID:12049920

  19. Microplate Technique for Determining Accumulation of Metals by Algae

    PubMed Central

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

    1981-01-01

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

  20. Exploring the potential of algae/bacteria interactions.

    PubMed

    Kouzuma, Atsushi; Watanabe, Kazuya

    2015-06-01

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

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

    SciTech Connect

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

    2015-12-01

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

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

    NASA Astrophysics Data System (ADS)

    Lin, Xiukun; Liu, Ming

    2012-12-01

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

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

    ScienceCinema

    Elliott, Doug

    2016-07-12

    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.

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

    DOEpatents

    Greenbaum, Elias

    1984-01-01

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

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

    SciTech Connect

    Elliott, Doug

    2013-12-17

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

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

    DOEpatents

    Greenbaum, E.

    1982-06-16

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

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

    SciTech Connect

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

    2011-01-01

    The controlled growth of microalgae as a feedstock for alternative transportation fuel continues to receive much attention. Microalgae have the characteristics of rapid growth rate, high oil (lipid) content, and ability to be grown in unconventional scenarios. Algae have also been touted as beneficial for CO{sub 2} reuse, as algae can be grown using CO{sub 2} emissions from fossil-based energy generation. Moreover, algae does not compete in the food chain, lessening the 'food versus fuel' debate. Most often, it is assumed that either rapid production rate or high oii content should be the primary factor in algae selection for algae-to-fuels production systems. However, many important characteristics of algae growth and lipid production must be considered for species selection, growth condition, and scale-up. Under light limited, high density, photoautotrophic conditions, the inherent growth rate of an organism does not affect biomass productivity, carbon fixation rate, and energy fixation rate. However, the oil productivity is organism dependent, due to physiological differences in how the organisms allocate captured photons for growth and oil production and due to the differing conditions under which organisms accumulate oils. Therefore, many different factors must be considered when assessing the overall energy efficiency of fuel production for a given algae species. Two species, Chlorella vulgaris and Botryococcus braunii, are popular choices when discussing algae-to-fuels systems. Chlorella is a very robust species, often outcompeting other species in mixed-culture systems, and produces a lipid that is composed primarily of free fatty acids and glycerides. Botryococcus is regarded as a slower growing species, and the lipid that it produces is characterized by high hydrocarbon content, primarily C28-C34 botryococcenes. The difference in growth rates is often considered to be an advantage oiChlorella. However, the total energy captured by each algal species in

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

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

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

  9. Method and apparatus for lysing and processing algae

    DOEpatents

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

    2013-03-05

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

  10. Exploring the potential of using algae in cosmetics.

    PubMed

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

    2015-05-01

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

  11. 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...

  12. [THE MICROSCOPIC ALGAE AS HUMAN PATHOGENS].

    PubMed

    Roman, Manuel Casal

    2014-01-01

    Some microscopic algae can cause different infectious diseases in humans, including skin, bone, and disseminated. These little-known emerging disease are more severe in immunocompromised patients. The confirmatory microbiological diagnosis must be done differential with yeast-like fungi that can be confused. Anti-fungal drugs and surgery, being quite frequent treatment failure have been used in the treatment. Given the increase of immunosuppression in the current medicine and new possibilities of microbiological diagnostics, it is logical that these diseases tend to increase, by which all physician should know them. PMID:27386675

  13. Factors affecting spore germination in algae - review.

    PubMed

    Agrawal, S C

    2009-01-01

    This review surveys whatever little is known on the influence of different environmental factors like light, temperature, nutrients, chemicals (such as plant hormones, vitamins, etc.), pH of the medium, biotic factors (such as algal extracellular substances, algal concentration, bacterial extracellular products, animal grazing and animal extracellular products), water movement, water stress, antibiotics, UV light, X-rays, gamma-rays, and pollution on the spore germination in algae. The work done on the dormancy of algal spores and on the role of vegetative cells in tolerating environmental stress is also incorporated. PMID:19826917

  14. [THE MICROSCOPIC ALGAE AS HUMAN PATHOGENS].

    PubMed

    Roman, Manuel Casal

    2014-01-01

    Some microscopic algae can cause different infectious diseases in humans, including skin, bone, and disseminated. These little-known emerging disease are more severe in immunocompromised patients. The confirmatory microbiological diagnosis must be done differential with yeast-like fungi that can be confused. Anti-fungal drugs and surgery, being quite frequent treatment failure have been used in the treatment. Given the increase of immunosuppression in the current medicine and new possibilities of microbiological diagnostics, it is logical that these diseases tend to increase, by which all physician should know them.

  15. Effect of petroleum hydrocarbons on algae

    SciTech Connect

    Bhadauria, S. ); Sengar, R.M.S. ); Mittal, S.; Bhattacharjee, S. )

    1992-01-01

    Algal species (65) were isolated from oil refinery effluent. Twenty-five of these species were cultured in Benecke's medium in a growth chamber, along with controls. Retardation in algal growth, inhibition in algal photosynthesis, and discoloration was observed in petroleum enriched medium. Few forms, viz. Cyclotella sp., Cosmarium sp., and Merismopedia sp. could not survive. The lag phase lengthened by several days and slope of exponential phase was also depressed. Chlamydomonas sp., Scenedesmus sp., Ankistrodesmus sp., Nitzschia sp. and Navicula sp. were comparatively susceptible to petroleum. Depression in carbon fixation, cell numbers, and total dry algal mass was noticeable, showing toxicity to both diatoms and green algae.

  16. Pheromones in marine algae: A technical approach

    NASA Astrophysics Data System (ADS)

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

    1995-03-01

    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.

  17. Algae-based oral recombinant vaccines.

    PubMed

    Specht, Elizabeth A; Mayfield, Stephen P

    2014-01-01

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

  18. Viruses and viruslike particles of eukaryotic algae.

    PubMed Central

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

    1991-01-01

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

  19. Effects of nitrogen dioxide on algae

    SciTech Connect

    Wodzinski, R.S.; Alexander, M.

    1980-01-01

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

  20. Effects of nitrogen dioxide on algae

    SciTech Connect

    Wodzinski, R.S.; Alexander, M.

    1980-01-01

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

  1. Algae-based oral recombinant vaccines.

    PubMed

    Specht, Elizabeth A; Mayfield, Stephen P

    2014-01-01

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

  2. Respiratory Chain of Colorless Algae II. Cyanophyta

    PubMed Central

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

    1966-01-01

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

  3. Algae Biofuels Co-Location Assessment Tool

    2013-09-18

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

  4. Algae Biofuels Co-Location Assessment Tool

    SciTech Connect

    2013-09-18

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

  5. Shewanella algae Peritonitis in Patients on Peritoneal Dialysis.

    PubMed

    Shanmuganathan, Malini; Goh, Bak Leong; Lim, Christopher; NorFadhlina, Zakaria; Fairol, Ibrahim

    Patients with peritonitis present with abdominal pain, diarrhea, fever, and turbid peritoneal dialysis (PD) fluid. Shewanella algae peritonitis has not yet been reported in PD patients in the literature. We present the first 2 cases of Shewanella algae peritonitis in PD patients. Mupirocin cream is applied on the exit site as prophylactic antibiotic therapy. PMID:27659933

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

    PubMed

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

    2002-12-01

    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.

  7. Cryoalgotox: Use of cryopreserved alga in a semistatic microplate test

    SciTech Connect

    Benhra, A.; Radetski, C.M.; Ferard, J.F.

    1997-03-01

    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.

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

    NASA Astrophysics Data System (ADS)

    Morrison, N.

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

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

    PubMed

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

    2016-02-01

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

  10. Auxin and cytoskeletal organization in algae.

    PubMed

    Jin, Qiaojun; Scherp, Peter; Heimann, Kirsten; Hasenstein, Karl H

    2008-05-01

    Hormones affect growth and alter the cytoskeleton suggesting that hormones and the cytoskeleton interact with each other. The cytoskeleton of ancestral algae such as Chara showed similar sensitivity to auxin as higher plants, even in generative structures but the sensitivity differed between IAA and alpha-NAA and presumably other auxins. The ability of cells to elongate depends on microtubule organization during the transition from disorganized to perpendicular to longitudinal organization of the cytoskeleton. Because of the many functions of the cytoskeleton it is possible that its composition is influenced by selective gene expression and adaptation to growth regulators. Co-localization of microtubules and F-actin change at a high temporal and spatial scale. High resolution measurements of mRNA expression indicate rapid turnover that may affect the composition of the cytoskeleton.

  11. High-fidelity phototaxis in biflagellate algae

    NASA Astrophysics Data System (ADS)

    Leptos, Kyriacos; Chioccioli, Maurizio; Furlan, Silvano; Pesci, Adriana; Goldstein, Raymond

    2015-11-01

    The single-cell alga Chlamydomonas reinhardtii is a motile biflagellate that can swim towards light for its photosynthetic requirements, a behavior referred to as phototaxis. The cell responds upon light stimulation through its rudimentary eye - the eyespot - by changing the beating amplitude of its two flagella accordingly - a process called the photoresponse. All this occurs in a coordinated fashion as Chlamydomonas spins about its body axis while swimming, thus experiencing oscillating intensities of light. We use high-speed video microscopy to measure the flagellar dynamics of the photoresponse on immobilized cells and interpret the results with a mathematical model of adaptation similar to that used previously for Volvox. These results are incorporated into a model of phototactic steering to yield trajectories that are compared to those obtained by three-dimensional tracking. Implications of these results for the evolution of multicellularity in the Volvocales are discussed.

  12. Autophagy in the model alga Chlamydomonas reinhardtii.

    PubMed

    Pérez-Pérez, María Esther; Crespo, José L

    2010-05-01

    Degradation and recycling of intracellular components via autophagy is conserved among eukaryotes. This catabolic process is mediated by autophagy-related (ATG) proteins, which have been identified in different systems including yeasts, mammals and plants. The genome of the model alga Chlamydomonas reinhardtii contains homologues to yeast and plant ATG genes although autophagy has not been previously described in this organism. In our study, we report the molecular characterization of autophagy in Chlamydomonas. Using the ATG8 protein from Chlamydomonas as a molecular autophagy marker, we demonstrate that this degradative process is induced in stationary cells or under different stresses such as nutrient limitation, oxidative stress or the accumulation of misfolded proteins in the endoplasmic reticulum. Our results also indicate that TOR, a major regulator of autophagy, inhibits this process in Chlamydomonas.

  13. Swimming like algae: biomimetic soft artificial cilia

    PubMed Central

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

    2013-01-01

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

  14. Swimming like algae: biomimetic soft artificial cilia.

    PubMed

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

    2013-01-01

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

  15. Random flow induced by swimming algae

    NASA Astrophysics Data System (ADS)

    Kantsler, Vasily; Rushkin, Ilia; Goldstein, Raymond

    2010-11-01

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

  16. Chloroplast Phylogenomic Inference of Green Algae Relationships

    PubMed Central

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

    2016-01-01

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

  17. An algae-covered alligator rests warily

    NASA Technical Reports Server (NTRS)

    2000-01-01

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

  18. Granular activated algae for wastewater treatment.

    PubMed

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

    2015-01-01

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

  19. The origin of red algae and the evolution of chloroplasts.

    PubMed

    Moreira, D; Le Guyader, H; Philippe, H

    2000-05-01

    Chloroplast structure and genome analyses support the hypothesis that three groups of organisms originated from the primary photosynthetic endosymbiosis between a cyanobacterium and a eukaryotic host: green plants (green algae + land plants), red algae and glaucophytes (for example, Cyanophora). Although phylogenies based on several mitochondrial genes support a specific green plants/red algae relationship, the phylogenetic analysis of nucleus-encoded genes yields inconclusive, sometimes contradictory results. To address this problem, we have analysed an alternative nuclear marker, elongation factor 2, and included new red algae and protist sequences. Here we provide significant support for a sisterhood of green plants and red algae. This sisterhood is also significantly supported by a multi-gene analysis of a fusion of 13 nuclear markers (5,171 amino acids). In addition, the analysis of an alternative fusion of 6 nuclear markers (1,938 amino acids) indicates that glaucophytes may be the closest relatives to the green plants/red algae group. Thus, our study provides evidence from nuclear markers for a single primary endosymbiosis at the origin of these groups, and supports a kingdom Plantae comprising green plants, red algae and glaucophytes.

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

    SciTech Connect

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

    2012-04-01

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

  1. Algae biomass cultivation in nitrogen rich biogas digestate.

    PubMed

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

    2015-01-01

    Because microalgae are known for quick biomass growth and nutrient uptake, there has been much interest in their use in research on wastewater treatment methods. While many studies have concentrated on the algal treatment of wastewaters with low to medium ammonium concentrations, there are several liquid waste streams with high ammonium concentrations that microalgae could potentially treat. The aim of this paper was to test ammonium tolerance of the indigenous algae community of Lake Mälaren and to use this mixed consortia of algae to remove nutrients from biogas digestate. Algae from Lake Mälaren were cultivated in Jaworski's Medium containing a range of ammonium concentrations and the resulting algal growth was determined. The algae were able to grow at NH4-N concentrations of up to 200 mg L(-1) after which there was significant inhibition. To test the effectiveness of the lake water algae on the treatment of biogas digestate, different pre-cultivation set-ups and biogas digestate concentrations were tested. It was determined that mixing pre-cultivated suspension algae with 25% of biogas digestate by volume, resulting in an ammonium concentration of around 300 mg L(-1), produced the highest algal growth. The algae were effective in removing 72.8±2.2% of NH4-N and 41.4±41.4% of PO4-P. PMID:26540532

  2. Biomass of algae growth on natural water medium.

    PubMed

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

    2015-01-01

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

  3. Algae biomass cultivation in nitrogen rich biogas digestate.

    PubMed

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

    2015-01-01

    Because microalgae are known for quick biomass growth and nutrient uptake, there has been much interest in their use in research on wastewater treatment methods. While many studies have concentrated on the algal treatment of wastewaters with low to medium ammonium concentrations, there are several liquid waste streams with high ammonium concentrations that microalgae could potentially treat. The aim of this paper was to test ammonium tolerance of the indigenous algae community of Lake Mälaren and to use this mixed consortia of algae to remove nutrients from biogas digestate. Algae from Lake Mälaren were cultivated in Jaworski's Medium containing a range of ammonium concentrations and the resulting algal growth was determined. The algae were able to grow at NH4-N concentrations of up to 200 mg L(-1) after which there was significant inhibition. To test the effectiveness of the lake water algae on the treatment of biogas digestate, different pre-cultivation set-ups and biogas digestate concentrations were tested. It was determined that mixing pre-cultivated suspension algae with 25% of biogas digestate by volume, resulting in an ammonium concentration of around 300 mg L(-1), produced the highest algal growth. The algae were effective in removing 72.8±2.2% of NH4-N and 41.4±41.4% of PO4-P.

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

    PubMed

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

    2010-09-01

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

  5. Photophysiology and cellular composition of sea ice algae

    SciTech Connect

    Lizotte, M.P.

    1989-01-01

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

  6. Activated chemical defenses suppress herbivory on freshwater red algae.

    PubMed

    Goodman, Keri M; Hay, Mark E

    2013-04-01

    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.

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

    DOEpatents

    Lee, James Weifu

    2014-02-18

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

  8. Application of synthetic biology in cyanobacteria and algae

    PubMed Central

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

    2012-01-01

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

  9. Evaluation of filamentous green algae as feedstocks for biofuel production.

    PubMed

    Zhang, Wei; Zhao, Yonggang; Cui, Binjie; Wang, Hui; Liu, Tianzhong

    2016-11-01

    Compared with unicellular microalgae, filamentous algae have high resistance to grazer-predation and low-cost recovery in large-scale production. Green algae, as the most diverse group of algae, included numerous filamentous genera and species. In this study, records of filamentous genera and species in green algae were firstly censused and classified. Then, seven filamentous strains subordinated in different genera were cultivated in bubbled-column to investigate their growth rate and energy molecular (lipid and starch) capacity. Four strains including Stigeoclonium sp., Oedogonium nodulosum, Hormidium sp. and Zygnema extenue were screened out due to their robust growth. And they all could accumulate triacylglycerols and starch in their biomass, but with different capacity. After nitrogen starvation, Hormidium sp. and Oedogonium nodulosum respectively exhibited high capacity of lipid (45.38% in dry weight) and starch (46.19% in dry weight) accumulation, which could be of high potential as feedstocks for biodiesel and bioethanol production. PMID:27598569

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

    ERIC Educational Resources Information Center

    Delpech, Roger

    2001-01-01

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

  11. Bicarbonate produced from carbon capture for algae culture.

    PubMed

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

    2011-11-01

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

  12. 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...

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

    PubMed

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

    2014-01-01

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

  14. Evaluation of filamentous green algae as feedstocks for biofuel production.

    PubMed

    Zhang, Wei; Zhao, Yonggang; Cui, Binjie; Wang, Hui; Liu, Tianzhong

    2016-11-01

    Compared with unicellular microalgae, filamentous algae have high resistance to grazer-predation and low-cost recovery in large-scale production. Green algae, as the most diverse group of algae, included numerous filamentous genera and species. In this study, records of filamentous genera and species in green algae were firstly censused and classified. Then, seven filamentous strains subordinated in different genera were cultivated in bubbled-column to investigate their growth rate and energy molecular (lipid and starch) capacity. Four strains including Stigeoclonium sp., Oedogonium nodulosum, Hormidium sp. and Zygnema extenue were screened out due to their robust growth. And they all could accumulate triacylglycerols and starch in their biomass, but with different capacity. After nitrogen starvation, Hormidium sp. and Oedogonium nodulosum respectively exhibited high capacity of lipid (45.38% in dry weight) and starch (46.19% in dry weight) accumulation, which could be of high potential as feedstocks for biodiesel and bioethanol production.

  15. Photobiological hydrogen production in green algae and photosynthetic bacteria

    SciTech Connect

    Greenbaum, E.

    1986-01-01

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

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

    NASA Technical Reports Server (NTRS)

    1990-01-01

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

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

    PubMed

    Menetrez, Marc Y

    2012-07-01

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

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

    SciTech Connect

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

    2012-12-03

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

  19. Extraction of mercury from ground-water using immobilized algae

    SciTech Connect

    Barkley, N.P.

    1991-01-01

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

  20. Study on algae removal by immobilized biosystem on sponge

    NASA Astrophysics Data System (ADS)

    Pei, Haiyan; Hu, Wenrong

    2006-10-01

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

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

    PubMed

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

    2015-03-01

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

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

    PubMed

    Menetrez, Marc Y

    2012-07-01

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

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

    PubMed

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

    2003-01-01

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

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

    PubMed Central

    Cruz-Rivera, Edwin; Friedlander, Michael

    2011-01-01

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

  5. Phosphorus-limited growth of a green alga and a blue-green alga

    SciTech Connect

    Lang, D.S.; Brown, E.J.

    1981-12-01

    The phosphorus-limited growth kinetics of the chlorophyte Scenedesmus quadricauda and the cyanophyte Synechococcus Nageli were studied by using batch and continuous culturing techniques. The steady-state phosphate transport capability and the phosphorus storage capacity is higher in S. Nageli than in S. quadricauda. Synechococcus Nageli can also deplete phosphate to much lower levels than can S. quadricauda. These results, along with their morphological characteristics, were used to construct partial physiological profiles for each organism. The profiles indicate that this unicellular cyanophyte (cyanobacterium) is better suited for growth in phosphorus-limited oligotrophic niches than is this chlorophyte (green alga). (Refs. 44).

  6. Comparative Transcriptome Analysis of Four Prymnesiophyte Algae

    PubMed Central

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

    2014-01-01

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

  7. Microfluidic one-way streets for algae

    NASA Astrophysics Data System (ADS)

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

    2012-02-01

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

  8. Mixotrophy in red tide algae raphidophytes.

    PubMed

    Jeong, Hae Jin

    2011-01-01

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

  9. Comparative transcriptome analysis of four prymnesiophyte algae.

    PubMed

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

    2014-01-01

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

  10. Is the Future Really in Algae?

    NASA Technical Reports Server (NTRS)

    Trent, Jonathan

    2011-01-01

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

  11. Two-step evolution of endosymbiosis between hydra and algae.

    PubMed

    Ishikawa, Masakazu; Shimizu, Hiroshi; Nozawa, Masafumi; Ikeo, Kazuho; Gojobori, Takashi

    2016-10-01

    In the Hydra vulgaris group, only 2 of the 25 strains in the collection of the National Institute of Genetics in Japan currently show endosymbiosis with green algae. However, whether the other non-symbiotic strains also have the potential to harbor algae remains unknown. The endosymbiotic potential of non-symbiotic strains that can harbor algae may have been acquired before or during divergence of the strains. With the aim of understanding the evolutionary process of endosymbiosis in the H. vulgaris group, we examined the endosymbiotic potential of non-symbiotic strains of the H. vulgaris group by artificially introducing endosymbiotic algae. We found that 12 of the 23 non-symbiotic strains were able to harbor the algae until reaching the grand-offspring through the asexual reproduction by budding. Moreover, a phylogenetic analysis of mitochondrial genome sequences showed that all the strains with endosymbiotic potential grouped into a single cluster (cluster γ). This cluster contained two strains (J7 and J10) that currently harbor algae; however, these strains were not the closest relatives. These results suggest that evolution of endosymbiosis occurred in two steps; first, endosymbiotic potential was gained once in the ancestor of the cluster γ lineage; second, strains J7 and J10 obtained algae independently after the divergence of the strains. By demonstrating the evolution of the endosymbiotic potential in non-symbiotic H. vulgaris group strains, we have clearly distinguished two evolutionary steps. The step-by-step evolutionary process provides significant insight into the evolution of endosymbiosis in cnidarians. PMID:27404042

  12. Two-step evolution of endosymbiosis between hydra and algae.

    PubMed

    Ishikawa, Masakazu; Shimizu, Hiroshi; Nozawa, Masafumi; Ikeo, Kazuho; Gojobori, Takashi

    2016-10-01

    In the Hydra vulgaris group, only 2 of the 25 strains in the collection of the National Institute of Genetics in Japan currently show endosymbiosis with green algae. However, whether the other non-symbiotic strains also have the potential to harbor algae remains unknown. The endosymbiotic potential of non-symbiotic strains that can harbor algae may have been acquired before or during divergence of the strains. With the aim of understanding the evolutionary process of endosymbiosis in the H. vulgaris group, we examined the endosymbiotic potential of non-symbiotic strains of the H. vulgaris group by artificially introducing endosymbiotic algae. We found that 12 of the 23 non-symbiotic strains were able to harbor the algae until reaching the grand-offspring through the asexual reproduction by budding. Moreover, a phylogenetic analysis of mitochondrial genome sequences showed that all the strains with endosymbiotic potential grouped into a single cluster (cluster γ). This cluster contained two strains (J7 and J10) that currently harbor algae; however, these strains were not the closest relatives. These results suggest that evolution of endosymbiosis occurred in two steps; first, endosymbiotic potential was gained once in the ancestor of the cluster γ lineage; second, strains J7 and J10 obtained algae independently after the divergence of the strains. By demonstrating the evolution of the endosymbiotic potential in non-symbiotic H. vulgaris group strains, we have clearly distinguished two evolutionary steps. The step-by-step evolutionary process provides significant insight into the evolution of endosymbiosis in cnidarians.

  13. Plasticity predicts evolution in a marine alga.

    PubMed

    Schaum, C Elisa; Collins, Sinéad

    2014-10-22

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

  14. Electrophysiology of turgor regulation in marine siphonous green algae.

    PubMed

    Bisson, M A; Beilby, M J; Shepherd, V A

    2006-05-01

    We review electrophysiological measures of turgor regulation in some siphonous green algae, primarily the giant-celled marine algae, Valonia and Ventricaria, with particular comparison to the well studied charophyte algae Chara and Lamprothamnium. The siphonous green algae have a less negative plasma membrane potential, and are unlikely to have a proton-based chemiosmotic transport system, dominated by active electrogenic K(+) uptake. We also make note of the unusual cellular structure of the siphonous green algae. Hypertonic stress, due to increased external osmotic pressure, is accompanied by positive-going potential difference (PD), increase in conductance, and slow turgor regulation. The relationship between these is not yet resolved, but may involve changes in K(+ )conductance (G (K)) or active K(+) transport at both membranes. Hypotonic turgor regulation, in response to decreased external osmotic pressure, is approximately 3 times faster than hypertonic turgor regulation. It is accompanied by a negative-going PD, although conductance also increases. The conductance increase and the magnitude of the PD change are strongly correlated with the magnitude of hypotonic stress.

  15. Anti-Phytopathogenic Activities of Macro-Algae Extracts

    PubMed Central

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

    2011-01-01

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

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

    PubMed

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

    2016-02-01

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

  17. Visualization of oxygen distribution patterns caused by coral and algae.

    PubMed

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

    2013-01-01

    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.

  18. Application of algae-biosensor for environmental monitoring.

    PubMed

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

    2015-01-01

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

  19. Extraction of mercury from groundwater using immobilized algae

    SciTech Connect

    Barkley, N.P. )

    1991-10-01

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

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

    PubMed

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

    2016-01-01

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

  1. Extraction of mercury from groundwater using immobilized algae.

    PubMed

    Barkley, N P

    1991-10-01

    Bio-Recovery Systems, Inc. conducted a project under the Emerging Technology portion of the United States Environmental Protection Agency's (EPAs) Superfund Innovative Technology Evaluation (SITE) Program to evaluate the ability of immobilized algae to adsorb mercury from contaminated groundwater in laboratory studies and pilot-scale field tests. Algal biomass was incorporated in a permeable polymeric matrix. The product, AlgaSORB, packed into adsorption columns, exhibited excellent flow characteristics, and functioned as a "biological" ion exchange resin. A sequence of eleven laboratory tests demonstrated the ability of this product to adsorb mercury from groundwater that contained high levels of total dissolved solids and hard water components. However, use of a single AlgaSORB preparation yielded nonrepeatable results with samples collected at different times of the year. The strategy of sequentially extracting the groundwater through two columns containing different preparations of AlgaSORB was developed and proved successful in laboratory and pilot-scale field tests. Field test results indicate that AlgaSORB could be economically competitive with ion exchange resins for removal of mercury, with the advantage that hardness and other dissolved solids do not appear to compete with heavy metals for binding capacity. PMID:1777231

  2. Actin gene family dynamics in cryptomonads and red algae.

    PubMed

    Tanifuji, Goro; Archibald, John M

    2010-09-01

    Here we present evidence for a complex evolutionary history of actin genes in red algae and cryptomonads, a group that acquired photosynthesis secondarily through the engulfment of a red algal endosymbiont. Four actin genes were found in the nuclear genome of the cryptomonad, Guillardia theta, and in the genome of the red alga, Galdieria sulphuraria, a member of the Cyanidiophytina. Phylogenetic analyses reveal that the both organisms possess two distinct sequence types, designated "type-1" and "type-2." A weak but consistent phylogenetic affinity between the cryptomonad type-2 sequences and the type-2 sequences of G. sulphuraria and red algae belonging to the Rhodophytina was observed. This is consistent with the possibility that the cryptomonad type-2 sequences are derived from the red algal endosymbiont that gave rise to the cryptomonad nucleomorph and plastid. Red algae as a whole possess two very different actin sequence types, with G. sulphuraria being the only organism thus far known to possess both. The common ancestor of Rhodophytina and Cyanidiophytina may have had two actin genes, with differential loss explaining the distribution of these genes in modern-day groups. Our study provides new insight into the evolution and divergence of actin genes in cryptomonads and red algae, and in doing so underscores the challenges associated with heterogeneity in actin sequence evolution and ortholog/paralog detection.

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

    PubMed

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

    2016-02-01

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

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

    DOEpatents

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

    1997-08-26

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

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

    DOEpatents

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

    1997-01-01

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

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

    PubMed

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

    2016-01-01

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

  7. Application of algae-biosensor for environmental monitoring.

    PubMed

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

    2015-01-01

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

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

    DOEpatents

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

    2012-11-06

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

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

    PubMed

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

    2013-10-01

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

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

    PubMed

    Singh, A K; Singh, M P

    2014-12-24

    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.

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

    PubMed

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

    2002-05-01

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

  12. [Immunostimulating activity of the lipopolysaccharides of blue-green algae].

    PubMed

    Besednova, N N; Smolina, T P; Mikheĭskaia, L V; Ovodova, R G

    1979-12-01

    The whole cells of blue-gree algae and lipopolysaccharides isolated from these cells were shown to stimulate the production of macro-(mainly) and microglobulin antibodies in rabbits. The macro- and microphage indices in rabbits increased significantly after the injection of LPS isolated from blue-green algae 24--48 hours before infecting the animals with a virulent Y. pseudotuberculosis strain. Besides, the inhibiting action of this strain on the migration of phagocytes to the site of infection was abolished immediately after the injection. The use of the indirect hemagglutination test allowed to prove the absence of close antigenic interrelations between blue-green algae and the following organisms: Spirulina platensis, Microcystis aeruginosa, Phormidium africanum and P. uncinatum. PMID:117655

  13. Algae from the arid southwestern United States: an annotated bibliography

    SciTech Connect

    Thomas, W.H.; Gaines, S.R.

    1983-06-01

    Desert algae are attractive biomass producers for capturing solar energy through photosynthesis of organic matter. They are probably capable of higher yields and efficiencies of light utilization than higher plants, and are already adapted to extremes of sunlight intensity, salinity and temperature such as are found in the desert. This report consists of an annotated bibliography of the literature on algae from the arid southwestern United States. It was prepared in anticipation of efforts to isolate desert algae and study their yields in the laboratory. These steps are necessary prior to setting up outdoor algal culture ponds. Desert areas are attractive for such applications because land, sunlight, and, to some extent, water resources are abundant there. References are sorted by state.

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

    DOEpatents

    Lee, James Weifu

    2011-04-26

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

  15. A look at diacylglycerol acyltransferases (DGATs) in algae.

    PubMed

    Chen, Jit Ern; Smith, Alison G

    2012-11-30

    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.

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

    PubMed

    Su, Yanyan; Mennerich, Artur; Urban, Brigitte

    2012-02-01

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

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

    PubMed

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

    2013-04-01

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

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

    SciTech Connect

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

    1991-03-01

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

  19. [Sedimentary Phosphorus Forms Under Disturbances and Algae in Taihu Lake].

    PubMed

    Chen, Jun; Li, Da-peng; Zhu, Pei-ying; Huang, Yong; Wang, Ren

    2015-12-01

    Sedimentary phosphorus forms were investigated to clarify the release of sedimentary phosphorus forms under the repeated disturbance with the addition of algae at different initial concentrations. The sediments and overlying water were taken from the Meiliang Bay in Taihu Lake. The results showed that the concentrations of NH₄ Cl-P and Res-P decreased, while the content of Fe/Al-P and Ca-P increased without disturbance. In addition, the Ca-P increased with the increase of the initial concentration of algae and the net increase of Ca-P increased by 48% (30 µg · L⁻¹), 66% (60 µg · L⁻¹), 74% (120 µg · L⁻¹), respectively. However, under the disturbance, the NH₄Cl-P and Res-P were significantly reduced, the Fe/Al-P increased significantly. The percentage of Fe/Al-P to Tot-P was up to 66. 2% (average of the 3 experiments with the addition of algae of 30 µg · L⁻¹, 60 µg · L⁻¹ and 120 µg L-¹), it was higher than the value (53.%, average of the 3 experiments) without the disturbance. Moreover, under the disturbance, the percentage of Ca-P to Tot-P was 24.1% (average of the 3 experiments with the addition of algae of 30 µg · L⁻¹, 60 µg⁻¹ and 120 µg · L⁻¹) and it was slightly lower than that (33.0%, average of the 3 experiments) without the disturbance. It is suggested that the coexistence of disturbance and algae facilitated the formation of Fe/Al-P, but the algae accelerated the formation of Ca-P without disturbance.

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

    PubMed

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

    2013-04-01

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

  1. Smallest algae thrive as the Arctic Ocean freshens.

    PubMed

    Li, William K W; McLaughlin, Fiona A; Lovejoy, Connie; Carmack, Eddy C

    2009-10-23

    As climate changes and the upper Arctic Ocean receives more heat and fresh water, it becomes more difficult for mixing processes to deliver nutrients from depth to the surface for phytoplankton growth. Competitive advantage will presumably accrue to small cells because they are more effective in acquiring nutrients and less susceptible to gravitational settling than large cells. Since 2004, we have discerned an increase in the smallest algae and bacteria along with a concomitant decrease in somewhat larger algae. If this trend toward a community of smaller cells is sustained, it may lead to reduced biological production at higher trophic levels. PMID:19900890

  2. Algae Biofuels Co-Location Assessment Tool for Canada

    2011-11-29

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

  3. Algae Biofuels Co-Location Assessment Tool for Canada

    SciTech Connect

    2011-11-29

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

  4. ECOLOGY: California Algae May Be Feared European Species.

    PubMed

    Kaiser, J

    2000-07-14

    A volleyball-court-sized patch of bright green algae in a San Diego lagoon has set off alarm bells among ecologists and officials. Scientists strongly suspect that the algae, Caulerpa taxifolia, is the same fast-growing, non-native clone that has swept over the northwestern Mediterranean sea floor in the past decade with devastating ecological consequences. A consortium of agencies and private groups has cordoned off the lagoon and is laying plans to poison the seaweed, marking the first major U.S. attempt to stop an incipient marine species invasion. PMID:17750394

  5. Algae as promising organisms for environment and health

    PubMed Central

    2011-01-01

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

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

    NASA Technical Reports Server (NTRS)

    Meyer, C.

    1979-01-01

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

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

    ERIC Educational Resources Information Center

    Blackwell, Will H.; Powell, Martha J.

    1995-01-01

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

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

    EPA Science Inventory

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

  9. Biodegradation of phenols by the alga Ochromonas danica.

    PubMed Central

    Semple, K T; Cain, R B

    1996-01-01

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

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

    PubMed

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

    2000-08-01

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

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

    PubMed

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

    2013-12-01

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

  12. A simple classification of the volvocine algae by formal languages.

    PubMed

    Yoshida, Hiroshi; Yokomori, Takashi; Suyama, Akira

    2005-11-01

    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

  13. [Phycobiliproteins of blue-green, red and cryptophytic algae].

    PubMed

    Stadnichuk, I N; Gusev, M V

    1979-04-01

    The present-day concepts on phycobiliproteins, the protein pigments of blue-green, red and cryptophyte algae are reviewed. The functions, distribution, localization, physico-chemical, spectral and immunochemical properties of phycobiliproteins are described. The properties of the polypeptide protein subunits and the composition and chemical structure of chromophores as well as their binding to the apoprotein molecules are discussed.

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

    PubMed

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

    2016-07-01

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

  15. Settlement of marine periphytic algae in a tropical estuary

    NASA Astrophysics Data System (ADS)

    Nayar, S.; Goh, B. P. L.; Chou, L. M.

    2005-08-01

    This note describes settlement studies of marine periphytic algae on glass substrata in a tropical estuary in Singapore. The rates of production in terms of 14C radiotracer uptake, biomass in terms of chlorophyll a, community structure and cell abundance were measured from the settled periphytic algae at various depths in the water column and compared with the prevailing hydrographical conditions. Relatively higher periphytic algal settlement was observed at 1 m depth, even though it was not statistically different from other depths. Diatoms such as Skeletonema costatum and Thalassiosira rotula dominated the assemblage, together with the marine cyanobacteria Synechococcus sp. The three settlement parameters viz., periphytic algal production, chlorophyll a and cell counts showed significant differences between the days of settlement, with no significant differences observed for different depths. The periphytic algal community in this study comprised 30 microalgal species, dominated by diatoms (78%), followed by cyanobacteria (19% - primarily Synechococcus sp.), green flagellates (1%), dinoflagellates (1%) and other forms accounting for the remaining 1% of the total cell counts. Correlation studies and principal component analysis (PCA) revealed significant influence of silicate concentrations in the water column with the settlement of periphytic algae in this estuary. Though photoinhibited at the surface, photosynthetically available radiation did not seem to influence the overall settlement of periphytic algae. Diatoms and Synechococcus in the periphytic algal community were influenced by water temperature, PAR, pH and dissolved oxygen as seen in the PCA plots.

  16. Survey of Hydrogenase Activity in Algae: Final Report

    SciTech Connect

    Brand, J. J.

    1982-04-01

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

  17. MicroRNAs in a multicellular green alga Volvox carteri.

    PubMed

    Li, Jingrui; Wu, Yang; Qi, Yijun

    2014-01-01

    microRNAs (miRNAs) have emerged as key components in the eukaryotic gene regulatory network. We and others have previously identified many miRNAs in a unicellular green alga, Chlamydomonas reinhardtii. To investigate whether miRNA-mediated gene regulation is a general mechanism in green algae and how miRNAs have been evolved in the green algal lineage, we examined small RNAs in Volvox carteri, a multicellular species in the same family with Chlamydomonas reinhardtii. We identified 174 miRNAs in Volvox, with many of them being highly enriched in gonidia or somatic cells. The targets of the miRNAs were predicted and many of them were subjected to miRNA-mediated cleavage in vivo, suggesting that miRNAs play regulatory roles in the biology of green algae. Our catalog of miRNAs and their targets provides a resource for further studies on the evolution, biological functions, and genomic properties of miRNAs in green algae. PMID:24369344

  18. Intracellular invasion of green algae in a salamander host

    PubMed Central

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

    2011-01-01

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

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

    USGS Publications Warehouse

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

    2008-01-01

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

  20. NADPH oxidases in Eukaryotes: red algae provide new hints!

    PubMed

    Hervé, Cécile; Tonon, Thierry; Collén, Jonas; Corre, Erwan; Boyen, Catherine

    2006-03-01

    The red macro-alga Chondrus crispus is known to produce superoxide radicals in response to cell-free extracts of its green algal pathogenic endophyte Acrochaete operculata. So far, no enzymes involved in this metabolism have been isolated from red algae. We report here the isolation of a gene encoding a homologue of the respiratory burst oxidase gp91(phox) in C. crispus, named Ccrboh. This single copy gene encodes a polypeptide of 825 amino acids. Search performed in available genome and EST algal databases identified sequences showing common features of NADPH oxidases in other algae such as the red unicellular Cyanidioschyzon merolae, the economically valuable red macro-alga Porphyra yezoensis and the two diatoms Phaeodactylum tricornutum and Thalassiosira pseudonana. Domain organization and phylogenetic relationships with plant, animal, fungal and algal NADPH oxidase homologues were analyzed. Transcription analysis of the C. crispus gene revealed that it was over-transcribed during infection of C. crispus gametophyte by the endophyte A. operculata, and after incubation in presence of atrazine, methyl jasmonate and hydroxyperoxides derived from C20 polyunsaturated fatty acids (PUFAs). These results also illustrate the interest of exploring the red algal lineage for gaining insight into the deep evolution of NADPH oxidases in Eukaryotes.

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

    NASA Astrophysics Data System (ADS)

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

    2003-04-01

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

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

    PubMed

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

    2016-07-01

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

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

    PubMed

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

    2000-08-01

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

  4. Antibiotic activity of lectins from marine algae against marine vibrios.

    PubMed

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

    2003-07-01

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

  5. Ecological assessments with algae: a review and synthesis.

    PubMed

    Stevenson, Jan

    2014-06-01

    Algae have been used for a century in environmental assessments of water bodies and are now used in countries around the world. This review synthesizes recent advances in the field around a framework for environmental assessment and management that can guide design of assessments, applications of phycology in assessments, and refinements of those applications to better support management decisions. Algae are critical parts of aquatic ecosystems that power food webs and biogeochemical cycling. Algae are also major sources of problems that threaten many ecosystems goods and services when abundances of nuisance and toxic taxa are high. Thus, algae can be used to indicate ecosystem goods and services, which complements how algal indicators are also used to assess levels of contaminants and habitat alterations (stressors). Understanding environmental managers' use of algal ecology, taxonomy, and physiology can guide our research and improve its application. Environmental assessments involve characterizing ecological condition and diagnosing causes and threats to ecosystems goods and services. Recent advances in characterizing condition include site-specific models that account for natural variability among habitats to better estimate effects of humans. Relationships between algal assemblages and stressors caused by humans help diagnose stressors and establish targets for protection and restoration. Many algal responses to stressors have thresholds that are particularly important for developing stakeholder consensus for stressor management targets. Future research on the regional-scale resilience of algal assemblages, the ecosystem goods and services they provide, and methods for monitoring and forecasting change will improve water resource management.

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

    DOEpatents

    Lee, James Weifu

    2010-01-05

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

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

    NASA Astrophysics Data System (ADS)

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

    2003-01-01

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

  8. Complete Chloroplast Genome Sequence of Phagomixotrophic Green Alga Cymbomonas tetramitiformis

    PubMed Central

    Paasch, Amber E.; Graham, Linda E.; Kim, Eunsoo

    2016-01-01

    We report here the complete chloroplast genome sequence of Cymbomonas tetramitiformis strain PLY262, which is a prasinophycean green alga that retains a phagomixotrophic mode of nutrition. The genome is 84,524 bp in length, with a G+C content of 37%, and contains 3 rRNAs, 26 tRNAs, and 76 protein-coding genes. PMID:27313295

  9. Ecological assessments with algae: a review and synthesis.

    PubMed

    Stevenson, Jan

    2014-06-01

    Algae have been used for a century in environmental assessments of water bodies and are now used in countries around the world. This review synthesizes recent advances in the field around a framework for environmental assessment and management that can guide design of assessments, applications of phycology in assessments, and refinements of those applications to better support management decisions. Algae are critical parts of aquatic ecosystems that power food webs and biogeochemical cycling. Algae are also major sources of problems that threaten many ecosystems goods and services when abundances of nuisance and toxic taxa are high. Thus, algae can be used to indicate ecosystem goods and services, which complements how algal indicators are also used to assess levels of contaminants and habitat alterations (stressors). Understanding environmental managers' use of algal ecology, taxonomy, and physiology can guide our research and improve its application. Environmental assessments involve characterizing ecological condition and diagnosing causes and threats to ecosystems goods and services. Recent advances in characterizing condition include site-specific models that account for natural variability among habitats to better estimate effects of humans. Relationships between algal assemblages and stressors caused by humans help diagnose stressors and establish targets for protection and restoration. Many algal responses to stressors have thresholds that are particularly important for developing stakeholder consensus for stressor management targets. Future research on the regional-scale resilience of algal assemblages, the ecosystem goods and services they provide, and methods for monitoring and forecasting change will improve water resource management. PMID:26988318

  10. A simple classification of the volvocine algae by formal languages.

    PubMed

    Yoshida, Hiroshi; Yokomori, Takashi; Suyama, Akira

    2005-11-01

    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.

  11. Higher plant origins and the phylogeny of green algae.

    PubMed

    Devereux, R; Loeblich, A R; Fox, G E

    1990-07-01

    5S rRNA sequences from six additional green algae lend strong molecular support for the major outlines of higher plant and green algae phylogeny that have been proposed under varying naming conventions by several authors. In particular, the molecular evidence now available unequivocally supports the existence of at least two well-separated divisions of the Chlorobionta: the Chlorophyta and the Streptophyta (i.e., charophytes) (according to the nomenclature of Bremer). The chlamydomonad 5S rRNAs are, however, sufficiently distinct from both clusters that it may ultimately prove preferable to establish a third taxon for them. In support of these conclusions 5S rRNA sequence data now exist for members of four diverse classes of chlorophytes. These sequences all exhibit considerably more phylogenetic affinity to one another than any of them show toward members of the other cluster, the Streptophyta, or the two Chlamydomonas strains. Among the Charophyceae, new 5S rRNA sequences are provided herein for three genera, Spirogyra, Klebsormidium, and Coleochaete. All of these sequences and the previously published Nitella sequence show greater resemblance among themselves and to the higher plants than they do to any of the other green algae examined to date. These results demonstrate that an appropriately named taxon that includes these green algae and the higher plants is strongly justified. The 5S rRNA data lack the resolution needed, however, to unequivocally determine which of several subdivisions of the charophytes is the sister group of the land plants. The evolutionary diversity of Chlamydomonas relative to the other green algae was recognized in earlier 5S rRNA studies but was unanticipated by ultrastructural work.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. FERMENTATIVE AND PHOTOCHEMICAL PRODUCTION OF HYDROGEN IN ALGAE

    PubMed Central

    Gaffron, Hans; Rubin, Jack

    1942-01-01

    1.. After 2 hours of fermentation in nitrogen the metabolism of those algae which were found capable of photoreduction with hydrogen changes in such a way that molecular hydrogen is released from the cell in addition to carbon dioxide. 2. The amount of hydrogen formed anaerobically in the dark depends on the amount of some unknown reserve substance in the cell. More hydrogen is formed in presence of added glucose, but no proportionality has been found between the amount of substrate added and that of hydrogen formed. This is probably due to the fact that two types of fermentation reactions exist, with little or no connection between them. Whereas mainly unknown organic acids are formed during the autofermentation, the addition of glucose causes a considerable increase in the production of lactic acid. 3. Algae which have been fermenting for several hours in the dark produce upon illumination free hydrogen at several times the rate observed in the dark, provided carbon dioxide is absent. 4. Certain concentrations of dinitrophenol strongly inhibit the evolution of hydrogen in the dark. Fermentation then continues mainly as a reaction leading to lactic acid. In such poisoned algae the photochemical liberation of hydrogen still continues. 5. If the algae are poisoned with dinitrophenol the presence of carbon dioxide will not interfere with the photochemical evolution of hydrogen. 6. The amount of hydrogen released in this new photochemical reaction depends on the presence of an unknown hydrogen donor in the cell; it can be increased by the addition of glucose but not in proportion to the amount added. 7. The results obtained allow for a more correct explanation of the anaerobic induction period previously described for Scenedesmus and similar algae. The possibility of a photochemical evolution of hydrogen had not been taken into account in the earlier experiments. 8. The origin of the hydrogen released under the influence of light is discussed. PMID:19873339

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

    PubMed

    Melis, Anastasios

    2007-10-01

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

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

    SciTech Connect

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

    1995-12-31

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

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

    PubMed Central

    Goldstein, Raymond E.

    2015-01-01

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

  16. Marine Polysaccharides from Algae with Potential Biomedical Applications

    PubMed Central

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

    2015-01-01

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

  17. Green Algae as Model Organisms for Biological Fluid Dynamics

    NASA Astrophysics Data System (ADS)

    Goldstein, Raymond E.

    2015-01-01

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

  18. Determination of aliphatic hydrocarbons in the alga Himanthalia elongata.

    PubMed

    Punín Crespo, M O; Lage Yusty, M A

    2004-02-01

    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

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

    PubMed

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

    2005-08-01

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

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

    USGS Publications Warehouse

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

    2003-01-01

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

  1. Recurring patterns in bacterioplankton dynamics during coastal spring algae blooms

    PubMed Central

    Teeling, Hanno; Fuchs, Bernhard M; Bennke, Christin M; Krüger, Karen; Chafee, Meghan; Kappelmann, Lennart; Reintjes, Greta; Waldmann, Jost; Quast, Christian; Glöckner, Frank Oliver; Lucas, Judith; Wichels, Antje; Gerdts, Gunnar; Wiltshire, Karen H; Amann, Rudolf I

    2016-01-01

    A process of global importance in carbon cycling is the remineralization of algae biomass by heterotrophic bacteria, most notably during massive marine algae blooms. Such blooms can trigger secondary blooms of planktonic bacteria that consist of swift successions of distinct bacterial clades, most prominently members of the Flavobacteriia, Gammaproteobacteria and the alphaproteobacterial Roseobacter clade. We investigated such successions during spring phytoplankton blooms in the southern North Sea (German Bight) for four consecutive years. Dense sampling and high-resolution taxonomic analyses allowed the detection of recurring patterns down to the genus level. Metagenome analyses also revealed recurrent patterns at the functional level, in particular with respect to algal polysaccharide degradation genes. We, therefore, hypothesize that even though there is substantial inter-annual variation between spring phytoplankton blooms, the accompanying succession of bacterial clades is largely governed by deterministic principles such as substrate-induced forcing. DOI: http://dx.doi.org/10.7554/eLife.11888.001 PMID:27054497

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

    SciTech Connect

    Holan, Z.R.; Volesky, B. . Dept. of Chemical Engineering)

    1994-05-01

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

  3. Recurring patterns in bacterioplankton dynamics during coastal spring algae blooms.

    PubMed

    Teeling, Hanno; Fuchs, Bernhard M; Bennke, Christin M; Krüger, Karen; Chafee, Meghan; Kappelmann, Lennart; Reintjes, Greta; Waldmann, Jost; Quast, Christian; Glöckner, Frank Oliver; Lucas, Judith; Wichels, Antje; Gerdts, Gunnar; Wiltshire, Karen H; Amann, Rudolf I

    2016-01-01

    A process of global importance in carbon cycling is the remineralization of algae biomass by heterotrophic bacteria, most notably during massive marine algae blooms. Such blooms can trigger secondary blooms of planktonic bacteria that consist of swift successions of distinct bacterial clades, most prominently members of the Flavobacteriia, Gammaproteobacteria and the alphaproteobacterial Roseobacter clade. We investigated such successions during spring phytoplankton blooms in the southern North Sea (German Bight) for four consecutive years. Dense sampling and high-resolution taxonomic analyses allowed the detection of recurring patterns down to the genus level. Metagenome analyses also revealed recurrent patterns at the functional level, in particular with respect to algal polysaccharide degradation genes. We, therefore, hypothesize that even though there is substantial inter-annual variation between spring phytoplankton blooms, the accompanying succession of bacterial clades is largely governed by deterministic principles such as substrate-induced forcing. PMID:27054497

  4. Recurring patterns in bacterioplankton dynamics during coastal spring algae blooms.

    PubMed

    Teeling, Hanno; Fuchs, Bernhard M; Bennke, Christin M; Krüger, Karen; Chafee, Meghan; Kappelmann, Lennart; Reintjes, Greta; Waldmann, Jost; Quast, Christian; Glöckner, Frank Oliver; Lucas, Judith; Wichels, Antje; Gerdts, Gunnar; Wiltshire, Karen H; Amann, Rudolf I

    2016-01-01

    A process of global importance in carbon cycling is the remineralization of algae biomass by heterotrophic bacteria, most notably during massive marine algae blooms. Such blooms can trigger secondary blooms of planktonic bacteria that consist of swift successions of distinct bacterial clades, most prominently members of the Flavobacteriia, Gammaproteobacteria and the alphaproteobacterial Roseobacter clade. We investigated such successions during spring phytoplankton blooms in the southern North Sea (German Bight) for four consecutive years. Dense sampling and high-resolution taxonomic analyses allowed the detection of recurring patterns down to the genus level. Metagenome analyses also revealed recurrent patterns at the functional level, in particular with respect to algal polysaccharide degradation genes. We, therefore, hypothesize that even though there is substantial inter-annual variation between spring phytoplankton blooms, the accompanying succession of bacterial clades is largely governed by deterministic principles such as substrate-induced forcing.

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

    PubMed

    Holan, Z R; Volesky, B

    1994-05-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  7. Bioremoval of toxic elements with aquatic plants and algae

    SciTech Connect

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

    1995-12-31

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

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

    PubMed

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

    2010-04-01

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

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

    NASA Technical Reports Server (NTRS)

    Lewin, R. A.

    1983-01-01

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

  10. Subunit structure of the phycobiliproteins of blue-green algae.

    PubMed

    Glazer, A N; Cohen-Bazire, G

    1971-07-01

    The phycobiliproteins of the blue-green algae Synechococcus sp. and Aphanocapsu sp. were characterized with respect to homogeneity, isoelectric point, and subunit composition. Each of the biliproteins consisted of two different noncovalently associated subunits, with molecular weights of about 20,000 and 16,000 for phycocyanin, 17,500 and 15,500 for allophycocyanin, and 22,000 and 20,000 for phycoerythrin. Covalently bound chromophore was associated with each subunit.

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

    PubMed

    Guarnieri, Michael T; Pienkos, Philip T

    2015-03-01

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

  12. EXTRACELLULAR POLYSACCHARIDES OF ALGAE: EFFECTS ON LIFE-SUPPORT SYSTEMS.

    PubMed

    MOORE, B G; TISCHER, R G

    1964-08-01

    The amount of extracellular polysaccharide produced by eight species of green and blue-green algae ranges from 174 milligrams per liter to 557 milligrams per liter. Most of the polymers are composed of four monosaccharides: a hexose, a pentose, a methyl pentose, and uronic acid. The production of excessive amounts of these photosynthetic end products will undoubtedly influence the effective recycling time of growth media in life-support systems.

  13. Evidence of ancient genome reduction in red algae (Rhodophyta).

    PubMed

    Qiu, Huan; Price, Dana C; Yang, Eun Chan; Yoon, Hwan Su; Bhattacharya, Debashish

    2015-08-01

    Red algae (Rhodophyta) comprise a monophyletic eukaryotic lineage of ~6,500 species with a fossil record that extends back 1.2 billion years. A surprising aspect of red algal evolution is that sequenced genomes encode a relatively limited gene inventory (~5-10 thousand genes) when compared with other free-living algae or to other eukaryotes. This suggests that the common ancestor of red algae may have undergone extensive genome reduction, which can result from lineage specialization to a symbiotic or parasitic lifestyle or adaptation to an extreme or oligotrophic environment. We gathered genome and transcriptome data from a total of 14 red algal genera that represent the major branches of this phylum to study genome evolution in Rhodophyta. Analysis of orthologous gene gains and losses identifies two putative major phases of genome reduction: (i) in the stem lineage leading to all red algae resulting in the loss of major functions such as flagellae and basal bodies, the glycosyl-phosphatidylinositol anchor biosynthesis pathway, and the autophagy regulation pathway; and (ii) in the common ancestor of the extremophilic Cyanidiophytina. Red algal genomes are also characterized by the recruitment of hundreds of bacterial genes through horizontal gene transfer that have taken on multiple functions in shared pathways and have replaced eukaryotic gene homologs. Our results suggest that Rhodophyta may trace their origin to a gene depauperate ancestor. Unlike plants, it appears that a limited gene inventory is sufficient to support the diversification of a major eukaryote lineage that possesses sophisticated multicellular reproductive structures and an elaborate triphasic sexual cycle. PMID:26986787

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

    PubMed Central

    2012-01-01

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

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

    PubMed

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

    2015-09-01

    Graphene represents a new class of nanomaterials that has attracted great interest due to its unique electrical, thermal, and mechanical properties. Once disposed in the environment, graphene can interact with biological systems and is expected to exhibit toxicological effects. The ecotoxicity of graphene and its derivatives, viz.: graphene oxide (GO) depends on their physicochemical properties, including purity, diameter, length, surface charge, functionalization and aggregation state. In this study we evaluated the effects of graphene oxide (GO) on green algae Raphidocelis subcapitata. The algae were exposed to different concentrations of GO pre-equilibrated for 24h with oligotrophic freshwater medium (20ml) during incubation in a growth chamber under controlled conditions: 120μEm(-2)s(-1) illumination; 12:12h light dark cycle and constant temperature of 22±2°C. Algal growth was monitored daily for 96h by direct cell counting. Reactive oxygen species level (ROS), membrane damage (cell viability) and autofluorescence (chl-a fluorescence) were evaluated using fluorescent staining and further analyzed by flow cytometry. The toxic effects from GO, as observed in algal density and autofluorescence, started at concentrations from 20 and 10μgmL(-1), respectively. Such toxicity is probably the result of ROS generation and membrane damage (cell viability). The shading effect caused by GO agglomeration in culture medium may also contribute to reduce algal density. The results reported here provide knowledge regarding the GO toxicity on green algae, contributing to a better understanding of its environmental behavior and impacts. PMID:26204245

  16. Microwave-enhanced pyrolysis of natural algae from water blooms.

    PubMed

    Zhang, Rui; Li, Linling; Tong, Dongmei; Hu, Changwei

    2016-07-01

    Microwave-enhanced pyrolysis (MEP) of natural algae under different reaction conditions was carried out. The optimal conditions for bio-oil production were the following: algae particle size of 20-5 mesh, microwave power of 600W, and 10% of activated carbon as microwave absorber and catalyst. The maximum liquid yield obtained under N2, 10% H2/Ar, and CO2 atmosphere was 49.1%, 51.7%, and 54.3% respectively. The energy yield of bio-products was 216.7%, 236.9% and 208.7% respectively. More long chain fatty acids were converted into hydrocarbons by hydrodeoxygenation under 10% H2/Ar atmosphere assisted by microwave over activated carbon containing small amounts of metals. Under CO2 atmosphere, carboxylic acids (66.6%) were the main products in bio-oil because the existence of CO2 vastly inhibited the decarboxylation. The MEP of algae was quick and efficient for bio-oil production, which provided a way to not only ameliorate the environment but also obtain fuel or chemicals at the same time.

  17. Phycobilisome Heterogeneity in the Red Alga Porphyra umbilicalis1

    PubMed Central

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

    1990-01-01

    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

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

    PubMed

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

    2013-05-01

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

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

    PubMed

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

    2015-01-01

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

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

    PubMed

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

    2015-09-01

    Graphene represents a new class of nanomaterials that has attracted great interest due to its unique electrical, thermal, and mechanical properties. Once disposed in the environment, graphene can interact with biological systems and is expected to exhibit toxicological effects. The ecotoxicity of graphene and its derivatives, viz.: graphene oxide (GO) depends on their physicochemical properties, including purity, diameter, length, surface charge, functionalization and aggregation state. In this study we evaluated the effects of graphene oxide (GO) on green algae Raphidocelis subcapitata. The algae were exposed to different concentrations of GO pre-equilibrated for 24h with oligotrophic freshwater medium (20ml) during incubation in a growth chamber under controlled conditions: 120μEm(-2)s(-1) illumination; 12:12h light dark cycle and constant temperature of 22±2°C. Algal growth was monitored daily for 96h by direct cell counting. Reactive oxygen species level (ROS), membrane damage (cell viability) and autofluorescence (chl-a fluorescence) were evaluated using fluorescent staining and further analyzed by flow cytometry. The toxic effects from GO, as observed in algal density and autofluorescence, started at concentrations from 20 and 10μgmL(-1), respectively. Such toxicity is probably the result of ROS generation and membrane damage (cell viability). The shading effect caused by GO agglomeration in culture medium may also contribute to reduce algal density. The results reported here provide knowledge regarding the GO toxicity on green algae, contributing to a better understanding of its environmental behavior and impacts.

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

    PubMed

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

    2013-09-01

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

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

    PubMed

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

    2016-02-15

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

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

    PubMed Central

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

    2015-01-01

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

  4. Origins of multicellular complexity: Volvox and the volvocine algae.

    PubMed

    Herron, Matthew D

    2016-03-01

    The collection of evolutionary transformations known as the 'major transitions' or 'transitions in individuality' resulted in changes in the units of evolution and in the hierarchical structure of cellular life. Volvox and related algae have become an important model system for the major transition from unicellular to multicellular life, which touches on several fundamental questions in evolutionary biology. The Third International Volvox Conference was held at the University of Cambridge in August 2015 to discuss recent advances in the biology and evolution of this group of algae. Here, I highlight the benefits of integrating phylogenetic comparative methods and experimental evolution with detailed studies of developmental genetics in a model system with substantial genetic and genomic resources. I summarize recent research on Volvox and its relatives and comment on its implications for the genomic changes underlying major evolutionary transitions, evolution and development of complex traits, evolution of sex and sexes, evolution of cellular differentiation and the biophysics of motility. Finally, I outline challenges and suggest future directions for research into the biology and evolution of the volvocine algae. PMID:26822195

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

    PubMed

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

    2014-01-01

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

  6. Multi-centennial reconstruction of Aleutian climate from coralline algae

    NASA Astrophysics Data System (ADS)

    Williams, B.; Halfar, J.; DeLong, K. L.; Smith, E.; Steneck, R.; Lebednik, P.; Jacob, D. E.; Fietzke, J.; Moore, K.

    2015-12-01

    Long-lived encrusting coralline algae yield robust reconstructions of mid-to-high latitude environmental change from their annually-banded high-magnesium calcite skeleton. The magnesium to calcium ratio measured in their skeleton reflects ambient seawater temperature at the time of formation. Thus, reconstructions from these algae are important to understanding the role of natural modes of climate variability versus that of external carbon dioxide in controlling climate in data sparse regions such as the northern North Pacific Ocean/southern Bering Sea. Here, we reconstruct regional seawater temperature from the skeletons of nine algae specimens from two islands in the Aleutian Archipelago. We find that seawater temperature increased ~1.4°C degrees over the past 350 years. The detrended seawater reconstruction correlates with storminess because storms moving across the North Pacific Ocean bring warmer water to the archipelago. Comparison of the algal seawater temperature reconstruction with instrumental and terrestrial proxy reconstructions reveals that atmospheric teleconnections to North America via the North Pacific storm tracks are not robust before the 20th century. This indicates that North Pacific climate processes inferred from the instrumental records should be cautiously extrapolated when describing earlier non-analogous climates or future climate change.

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

    PubMed

    Domozych, David S; Domozych, Catherine E

    2014-01-01

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

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

    PubMed

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

    2015-05-01

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

  9. Towards tradable permits for filamentous green algae pollution.

    PubMed

    de Lange, W J; Botha, A M; Oberholster, P J

    2016-09-01

    Water pollution permit systems are challenging to design and implement. Operational systems that has maintained functionality remains few and far between, particularly in developing countries. We present current progress towards developing such a system for nutrient enrichment based water pollution, mainly from commercial agriculture. We applied a production function approach to first estimate the monetary value of the impact of the pollution, which is then used as reference point for establishing a reserve price for pollution permits. The subsequent market making process is explained according to five steps including permit design, terms, conditions and transactional protocol, the monitoring system, piloting and implementation. The monetary value of the impact of pollution was estimated at R1887 per hectare per year, which not only provide a "management budget" for filamentous green algae mitigation strategies in the study area, but also enabled the calculation of a reserve price for filamentous green algae pollution permits, which was estimated between R2.25 and R111 per gram filamentous algae and R8.99 per gram at the preferred state.

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

    PubMed Central

    Domozych, David S.; Domozych, Catherine E.

    2014-01-01

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

  11. The origin of red algae: implications for plastid evolution.

    PubMed

    Stiller, J W; Hall, B D

    1997-04-29

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

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

    PubMed

    Wolkenstein, Klaus; Gross, Jürgen H; Falk, Heinz

    2010-11-01

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

  13. Ecology of planktonic foraminifera and their symbiotic algae

    SciTech Connect

    Gastrich, M.D.

    1986-01-01

    Two types of symbiotic algae occurred abundantly and persistently in the cytoplasm of several species of planktonic Foraminifera over a ten year period in different tropical and subtropical areas of the North Atlantic Ocean. These planktonic Foraminifera host species consistently harbored either dinoflagellates or a newly described minute coccoid algal type. There appeared to be a specific host-symbiont relationship in these species regardless of year, season or geographic locality. The larger ovoid dinoflagellates (Pyrrhophycophyta) occur in the spinose species Globigerinoides ruber, Globigerinoides sacculifer, G. conglobatus and Orbulina universa. The smaller alga, from 1.5 to 3.5 um in diameter, occurs in one spinose species Globigerinella aequilateralis and also in the non-spinose species Globigerinita glutinata, Globoquadrina dutertrei, Globorotalia menardii, Globorotalia cristata, Globorotalia inflata, Candeina nitida, in various juvenile specimens and at all seasons except the winter months in Pulleniatina obliquiloculata and Globorotalial hirsuta. Controlled laboratory studies indicated a significant C incorporation into the host cytoplasm and inorganic calcium carbonate test of Globigerinoides ruber. During incubation for up to two hours, the /sup 14/C uptake into the cytoplasm and test in the light was significantly greater than uptake in the dark by living specimens or by dead foraminifers. There appears to be light-enhanced uptake of /sup 14/C into the test with dinoflagellate photosynthesis contributing to host calcification. In culture, symbiotic algae were observed to survive for the duration of the lifespan of their hosts.

  14. Measurement of Carbon Dioxide Compensation Points of Freshwater Algae 1

    PubMed Central

    Birmingham, Brendan C.; Colman, Brian

    1979-01-01

    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

  15. Toxic effects of decomposing red algae on littoral organisms

    NASA Astrophysics Data System (ADS)

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

    2005-03-01

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

  16. Sulfated phenolic acids from Dasycladales siphonous green algae.

    PubMed

    Kurth, Caroline; Welling, Matthew; Pohnert, Georg

    2015-09-01

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

  17. Origins of multicellular complexity: Volvox and the volvocine algae.

    PubMed

    Herron, Matthew D

    2016-03-01

    The collection of evolutionary transformations known as the 'major transitions' or 'transitions in individuality' resulted in changes in the units of evolution and in the hierarchical structure of cellular life. Volvox and related algae have become an important model system for the major transition from unicellular to multicellular life, which touches on several fundamental questions in evolutionary biology. The Third International Volvox Conference was held at the University of Cambridge in August 2015 to discuss recent advances in the biology and evolution of this group of algae. Here, I highlight the benefits of integrating phylogenetic comparative methods and experimental evolution with detailed studies of developmental genetics in a model system with substantial genetic and genomic resources. I summarize recent research on Volvox and its relatives and comment on its implications for the genomic changes underlying major evolutionary transitions, evolution and development of complex traits, evolution of sex and sexes, evolution of cellular differentiation and the biophysics of motility. Finally, I outline challenges and suggest future directions for research into the biology and evolution of the volvocine algae.

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

    PubMed Central

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

    2015-01-01

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

  19. Uptake and distribution of technetium in several marine algae

    SciTech Connect

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

    1983-01-01

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

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

    PubMed Central

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

    2013-01-01

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

  1. Extraction, Purification, and NMR Analysis of Terpenes from Brown Algae.

    PubMed

    Gaysinski, Marc; Ortalo-Magné, Annick; Thomas, Olivier P; Culioli, Gérald

    2015-01-01

    Algal terpenes constitute a wide and well-documented group of marine natural products with structures differing from their terrestrial plant biosynthetic analogues. Amongst macroalgae, brown seaweeds are considered as one of the richest source of biologically and ecologically relevant terpenoids. These metabolites, mostly encountered in algae of the class Phaeophyceae, are mainly diterpenes and meroditerpenes (metabolites of mixed biogenesis characterized by a toluquinol or a toluquinone nucleus linked to a diterpene moiety).In this chapter, we describe analytical processes commonly employed for the isolation and structural characterization of the main terpenoid constituents obtained from organic extracts of brown algae. The successive steps include (1) extraction of lipidic content from algal samples; (2) purification of terpenes by column chromatography and semi-preparative high-performance liquid chromatography; and (3) structure elucidation of the isolated terpenes by means of 1D and 2D nuclear magnetic resonance (NMR). More precisely, we propose a representative methodology which allows the isolation and structural determination of the monocyclic meroditerpene methoxybifurcarenone (MBFC) from the Mediterranean brown alga Cystoseira amentacea var. stricta. This methodology has a large field of applications and can then be extended to terpenes isolated from other species of the family Sargassaceae.

  2. Microwave-enhanced pyrolysis of natural algae from water blooms.

    PubMed

    Zhang, Rui; Li, Linling; Tong, Dongmei; Hu, Changwei

    2016-07-01

    Microwave-enhanced pyrolysis (MEP) of natural algae under different reaction conditions was carried out. The optimal conditions for bio-oil production were the following: algae particle size of 20-5 mesh, microwave power of 600W, and 10% of activated carbon as microwave absorber and catalyst. The maximum liquid yield obtained under N2, 10% H2/Ar, and CO2 atmosphere was 49.1%, 51.7%, and 54.3% respectively. The energy yield of bio-products was 216.7%, 236.9% and 208.7% respectively. More long chain fatty acids were converted into hydrocarbons by hydrodeoxygenation under 10% H2/Ar atmosphere assisted by microwave over activated carbon containing small amounts of metals. Under CO2 atmosphere, carboxylic acids (66.6%) were the main products in bio-oil because the existence of CO2 vastly inhibited the decarboxylation. The MEP of algae was quick and efficient for bio-oil production, which provided a way to not only ameliorate the environment but also obtain fuel or chemicals at the same time. PMID:27128164

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

    PubMed

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

    2015-05-01

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

  4. Relative Contributions of Various Cellular Mechanisms to Loss of Algae during Cnidarian Bleaching.

    PubMed

    Bieri, Tamaki; Onishi, Masayuki; Xiang, Tingting; Grossman, Arthur R; Pringle, John R

    2016-01-01

    When exposed to stress such as high seawater temperature, corals and other cnidarians can bleach due to loss of symbiotic algae from the host tissue and/or loss of pigments from the algae. Although the environmental conditions that trigger bleaching are reasonably well known, its cellular and molecular mechanisms are not well understood. Previous studies have reported the occurrence of at least four different cellular mechanisms for the loss of symbiotic algae from the host tissue: in situ degradation of algae, exocytic release of algae from the host, detachment of host cells containing algae, and death of host cells containing algae. The relative contributions of these several mechanisms to bleaching remain unclear, and it is also not known whether these relative contributions change in animals subjected to different types and/or durations of stresses. In this study, we used a clonal population of the small sea anemone Aiptasia, exposed individuals to various precisely controlled stress conditions, and quantitatively assessed the several possible bleaching mechanisms in parallel. Under all stress conditions tested, except for acute cold shock at 4°C, expulsion of intact algae from the host cells appeared to be by far the predominant mechanism of bleaching. During acute cold shock, in situ degradation of algae and host-cell detachment also became quantitatively significant, and the algae released under these conditions appeared to be severely damaged. PMID:27119147

  5. Viruses of symbiotic Chlorella-like algae isolated from Paramecium bursaria and Hydra viridis

    PubMed Central

    Van Etten, James L.; Meints, Russel H.; Kuczmarski, Daniel; Burbank, Dwight E.; Lee, Kit

    1982-01-01

    We previously reported that isolation of symbiotic Chlorella-like algae from the Florida strain of Hydra viridis induced replication of a virus (designated HVCV-1) in the algae. We now report that isolation of symbiotic Chlorella-like algae from four other sources of green hydra and one source of the protozoan Paramecium bursaria also induced virus synthesis. Algae from one of these hydra contained a virus identical to HVCV-1 (based on its rate of sedimentation, buoyant density, reaction to HVCV-1 antiserum, and DNA restriction fragments) whereas algae from the other three hydra contained another similar, but distinct, virus (designated HVCV-2). The virus from the paramecium algae (designated PBCV-1) was distinct from both HVCV-1 and HVCV-2. The symbiotic algae in the hydra could also be distinguished ultrastructurally. Chloroplasts of both algae that produced HVCV-1 lacked a pyrenoid whereas chloroplasts of the other three symbiotic algae contained pyrenoids. Since all symbiotic eukaryotic algae we have examined have had virus, a potential viral role in symbiosis is suggested. Images PMID:16593198

  6. Relative Contributions of Various Cellular Mechanisms to Loss of Algae during Cnidarian Bleaching

    PubMed Central

    Bieri, Tamaki; Onishi, Masayuki; Xiang, Tingting; Grossman, Arthur R.; Pringle, John R

    2016-01-01

    When exposed to stress such as high seawater temperature, corals and other cnidarians can bleach due to loss of symbiotic algae from the host tissue and/or loss of pigments from the algae. Although the environmental conditions that trigger bleaching are reasonably well known, its cellular and molecular mechanisms are not well understood. Previous studies have reported the occurrence of at least four different cellular mechanisms for the loss of symbiotic algae from the host tissue: in situ degradation of algae, exocytic release of algae from the host, detachment of host cells containing algae, and death of host cells containing algae. The relative contributions of these several mechanisms to bleaching remain unclear, and it is also not known whether these relative contributions change in animals subjected to different types and/or durations of stresses. In this study, we used a clonal population of the small sea anemone Aiptasia, exposed individuals to various precisely controlled stress conditions, and quantitatively assessed the several possible bleaching mechanisms in parallel. Under all stress conditions tested, except for acute cold shock at 4°C, expulsion of intact algae from the host cells appeared to be by far the predominant mechanism of bleaching. During acute cold shock, in situ degradation of algae and host-cell detachment also became quantitatively significant, and the algae released under these conditions appeared to be severely damaged. PMID:27119147

  7. Relative Contributions of Various Cellular Mechanisms to Loss of Algae during Cnidarian Bleaching.

    PubMed

    Bieri, Tamaki; Onishi, Masayuki; Xiang, Tingting; Grossman, Arthur R; Pringle, John R

    2016-01-01

    When exposed to stress such as high seawater temperature, corals and other cnidarians can bleach due to loss of symbiotic algae from the host tissue and/or loss of pigments from the algae. Although the environmental conditions that trigger bleaching are reasonably well known, its cellular and molecular mechanisms are not well understood. Previous studies have reported the occurrence of at least four different cellular mechanisms for the loss of symbiotic algae from the host tissue: in situ degradation of algae, exocytic release of algae from the host, detachment of host cells containing algae, and death of host cells containing algae. The relative contributions of these several mechanisms to bleaching remain unclear, and it is also not known whether these relative contributions change in animals subjected to different types and/or durations of stresses. In this study, we used a clonal population of the small sea anemone Aiptasia, exposed individuals to various precisely controlled stress conditions, and quantitatively assessed the several possible bleaching mechanisms in parallel. Under all stress conditions tested, except for acute cold shock at 4°C, expulsion of intact algae from the host cells appeared to be by far the predominant mechanism of bleaching. During acute cold shock, in situ degradation of algae and host-cell detachment also became quantitatively significant, and the algae released under these conditions appeared to be severely damaged.

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

    NASA Astrophysics Data System (ADS)

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

    1996-05-01

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

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

    PubMed

    Peng, Shanshan; Colosi, Lisa M

    2016-01-01

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

  10. AlgaeSim: a model for integrated algal biofuel production and wastewater treatment.

    PubMed

    Drexler, Ivy L C; Joustra, Caryssa; Prieto, Ana; Bair, Robert; Yeh, Daniel H

    2014-02-01

    AlgaeSim, a dynamic multiple-systems (C, N, P) mass balance model, was developed to explore the potential for algae biomass production from wastewater by coupling two photobioreactors into the main treatment train at a municipal wastewater resource recovery facility (WRRF) in Tampa, Florida. The scoping model examined the synergy between algae cultivation and wastewater treatment through algal growth and substrate removal kinetics, as well as through macroeconomic analyses of biomass conversion to bioproducts. Sensitivity analyses showed that biomass production is strongly dependent on Monod variables and harvesting regime, with sensitivity changing with growth phase. Profitability was sensitive to processing costs and market prices of products. Under scenarios based on current market conditions and typical algae production, AlgaeSim shows that a WRRF can potentially generate significant profit if algae are processed for biodiesel, biogas, or fertilizer. Wastewater resource recovery facilities could similarly save on operating costs resulting from the reduction in aeration (for nitrification) and chemicals (for denitrification).

  11. [Study on the degradation and transformation of nonylphenol in water containing algae].

    PubMed

    Peng, Zhang-E; Feng, Jin-Mei; He, Shu-Ying; Wu, Feng

    2012-10-01

    The photodegradation of nonylphenol induced by two common freshwater algae was investigated. The mechanism of nonylphenol photodegradation induced by algae was analyzed. The synergistic induction of nonylphenol degradation by algae and substances in water such as humic acid and ferric ions was also investigated. Results showed that the algae could induce the photodegradation of nonylphenol. The degradation of nonylphenol in water in the presence of algae, humic acid and ferric ions was obvious and the efficiency of degradation could reach 58% after 4 h illumination. Based on the results, it was speculated that the algae, humic acid and ferric ions system could produce more active oxygen after illumination, which could promote the photodegradation of the organic contaminants in water.

  12. Green Algae and the Origins of Multicellularity in the Plant Kingdom

    PubMed Central

    Umen, James G.

    2014-01-01

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

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

    PubMed

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

    2013-12-01

    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.

  14. Microcontact imprinting of algae for biofuel systems: the effects of the polymer concentration.

    PubMed

    Lee, Mei-Hwa; Thomas, James L; Lai, Ming-Yuan; Shih, Ching-Ping; Lin, Hung-Yin

    2014-11-25

    Microcontact imprinting of cells often involves the deposition of a polymer solution onto a monolayer cell stamp, followed by solvent evaporation. Thus, the concentration of the polymer may play an important role in the final morphology and efficacy of the imprinted film. In this work, various concentrations of poly(ethylene-co-vinyl alcohol) (EVAL) were dissolved in dimethyl sulfoxide (DMSO) for the microcontact imprinting of algae on an electrode. Scanning electron microscopy and fluorescence spectrometry were used to characterize the surface morphology and recognition capacity of algae to the algae-imprinted cavities. The readsorption of algae onto algae-imprinted EVAL thin films was quantified to obtain the EVAL concentration that maximized algal binding. Finally, the power and current density of an algal biofuel cell with the algae-imprinted EVAL-coated electrode were measured and found to be approximately double those of such a cell with a Pt/indium tin oxide (ITO)/poly(ethylene terephthalate) (PET) electrode.

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

    PubMed

    Peng, Shanshan; Colosi, Lisa M

    2016-01-01

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

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

    PubMed

    Umen, James G

    2014-10-16

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

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

    PubMed Central

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

    2006-01-01

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

  18. Endozoic algae in shelled gastropods — a new symbiotic association in coral reefs?

    NASA Astrophysics Data System (ADS)

    Berner, T.; Wishkovsky, A.; Dubinsky, Z.

    1986-10-01

    Live algae were found in the hepatopancreas and gonads of the Red Sea snail Strombus tricornis. These organs are constantly concealed within the upper whorls of the snail's shell. Light penetration was 5 15% of the incident light reaching the shell. Pigment analysis indicated the presence of chlorophyll a, c and peridinin, a composition resembling the Dinoflagellata. Chlorophyll a concentration in the algae was 1.18±0.36 pg chl/cell. 14C assimilation of isolated algae incubated in the light exceeded that of dark controls, demonstrating the photosynthetic activity of the endozoic algae.

  19. Biodiversity of algae and protozoa in a natural waste stabilization pond: a field study.

    PubMed

    Tharavathi, N C; Hosetti, B B

    2003-04-01

    A field study was carried out on the biodiversity of protozoa and algae from a natural waste stabilization pond during November, 1996 to April, 1997. The raw waste and pond samples were analysed for physico-chemical and biological parameters. High dissolved oxygen (DO) coinciding with phytoplankton peak was recorded. The algae--Chlorella vulgaris, Scenedesmus acuminatus, Oscillatoria brevis and Nostoc piscinale and Protozoa--Paramecium caudatum, Acanthamoeba sp., Bodo saltans and Oikomonas termo were obvious as dominant species, whereas algae Ochromonas pyriformis and Synura uvella and protozoa, Didinium masutum and Stentor coerulus were noted as rare species. Totally 71 species of algae and 13 species of protozoa were identified. PMID:12974463

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

    PubMed Central

    2013-01-01

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

  1. Biodiversity of algae and protozoa in a natural waste stabilization pond: a field study.

    PubMed

    Tharavathi, N C; Hosetti, B B

    2003-04-01

    A field study was carried out on the biodiversity of protozoa and algae from a natural waste stabilization pond during November, 1996 to April, 1997. The raw waste and pond samples were analysed for physico-chemical and biological parameters. High dissolved oxygen (DO) coinciding with phytoplankton peak was recorded. The algae--Chlorella vulgaris, Scenedesmus acuminatus, Oscillatoria brevis and Nostoc piscinale and Protozoa--Paramecium caudatum, Acanthamoeba sp., Bodo saltans and Oikomonas termo were obvious as dominant species, whereas algae Ochromonas pyriformis and Synura uvella and protozoa, Didinium masutum and Stentor coerulus were noted as rare species. Totally 71 species of algae and 13 species of protozoa were identified.

  2. Kinetics and equilibrium properties of the biosorption of Cu2+ by algae.

    PubMed

    Wang, Qiong; Peckenham, John; Pinto, Jamie; Patterson, Howard

    2012-11-01

    The purpose of this study was to examine the kinetics and equilibrium properties of freshwater algae with Cu(2+). This was a model system to explore using algae as biosensors for water quality. Methods included making luminescence measurements (fluorescence) and copper ion-selective electrode (CuISE) measurements vs. time to obtain kinetic data. Results were analyzed using a pseudo-first-order model to calculate the rate constants of Cu(2+) uptake by algae: k (p(Cu-algae)) = 0.0025 ± 0.0006 s(-1) by CuISE and k (p(Cu-algae)) = 0.0034 ± 0.0011 s(-1) by luminescence. The binding constant of Cu-algae, K (Cu-algae), was 1.62 ± 0.07 × 10(7) M(-1). Fluorescence results analyzed using the Stern-Volmer relationship indicate that algae have two types of binding sites of which only one appears to affect quenching. The fluorescence-based method was found to be able to detect the reaction of algae with Cu(2+) quickly and at a detection limit of 0.1 mg L(-1).

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

    ERIC Educational Resources Information Center

    Hungerford, James J.

    1988-01-01

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

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

    SciTech Connect

    Seki, Hideshi; Suzuki, Akira

    1998-10-01

    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.

  5. The ecology of viruses that infect eukaryotic algae.

    PubMed

    Short, Steven M

    2012-09-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

  7. Spectroradiometric monitoring for open outdoor culturing of algae and cyanobacteria

    SciTech Connect

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

    2014-08-20

    We assess the measurement of hyperspectral reflectance for the outdoor monitoring of green algae and cyanobacteria cultures with a multi-channel, fiber-coupled spectroradiometer. Reflectance data acquired over a four-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, 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 both 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 non-sampling measurement of biomass in outdoor ponds. Other fitting parameters in the reflectance model are compared to auxiliary measurements and physics-based calculations. The magnitudes of the sunlight and skylight water-surface contributions derived from the reflectance model compare favorably with Fresnel reflectance calculations, while the reflectance-derived quantum efficiency of Chl-a fluorescence is found to be in agreement with literature values. To conlclude, the water temperature derived from the reflectance model exhibits excellent agreement with thermocouple measurements during the morning hours and highlights significantly elevated temperatures in the afternoon hours.

  8. Spectroradiometric monitoring for open outdoor culturing of algae and cyanobacteria

    DOE PAGES

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

    2014-08-20

    We assess the measurement of hyperspectral reflectance for the outdoor monitoring of green algae and cyanobacteria cultures with a multi-channel, fiber-coupled spectroradiometer. Reflectance data acquired over a four-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, 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 approximatedmore » 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 both 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 non-sampling measurement of biomass in outdoor ponds. Other fitting parameters in the reflectance model are compared to auxiliary measurements and physics-based calculations. The magnitudes of the sunlight and skylight water-surface contributions derived from the reflectance model compare favorably with Fresnel reflectance calculations, while the reflectance-derived quantum efficiency of Chl-a fluorescence is found to be in agreement with literature values. To conlclude, the water temperature derived from the reflectance model exhibits excellent agreement with thermocouple measurements during the morning hours and highlights significantly elevated temperatures in the afternoon hours.« less

  9. Microwave-Assisted Extraction of Fucoidan from Marine Algae.

    PubMed

    Mussatto, Solange I

    2015-01-01

    Microwave-assisted extraction (MAE) is a technique that can be applied to extract compounds from different natural resources. In this chapter, the use of this technique to extract fucoidan from marine algae is described. The method involves a closed MAE system, ultrapure water as extraction solvent, and suitable conditions of time, pressure, and algal biomass/water ratio. By using this procedure under the specified conditions, the penetration of the electromagnetic waves into the material structure occurs in an efficient manner, generating a distributed heat source that promotes the fucoidan extraction from the algal biomass. PMID:26108504

  10. Numerical simulation of alga growth and control in Dalian Bay.

    PubMed

    Li, Ying; Huang, Caisheng; Zhou, Jiti

    2013-12-01

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

  11. Genetic transformation of the model green alga Chlamydomonas reinhardtii.

    PubMed

    Neupert, Juliane; Shao, Ning; Lu, Yinghong; Bock, Ralph

    2012-01-01

    Over the past three decades, the single-celled green alga Chlamydomonas reinhardtii has become an invaluable model organism in plant biology and an attractive production host in biotechnology. The genetic transformation of Chlamydomonas is relatively simple and efficient, but achieving high expression levels of foreign genes has remained challenging. Here, we provide working protocols for algal cultivation and transformation as well as for selection and analysis of transgenic algal clones. We focus on two commonly used transformation methods for Chlamydomonas: glass bead-assisted transformation and particle gun-mediated (biolistic) transformation. In addition, we describe available tools for promoting efficient transgene expression and highlight important considerations for designing transformation vectors.

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

    SciTech Connect

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

    1988-06-01

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

  13. The role of algae in mine drainage bioremediation

    SciTech Connect

    Davison, J. )

    1990-06-01

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

  14. Bioactivities from Marine Algae of the Genus Gracilaria

    PubMed Central

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

    2011-01-01

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

  15. The value of post-extracted algae residue

    DOE PAGES

    Bryant, Henry; Gogichaishvili, Ilia; Anderson, David; Richardson, James; Sawyer, Jason; Wickersham, Tryon; Drewery, Merritt

    2012-07-26

    This paper develops a hedonic pricing model for post-extracted algae residue (PEAR), which can be used for assessing the economic feasibility of an algal production enterprise. Prices and nutritional characteristics of commonly employed livestock feed ingredients are used to estimate the value of PEAR based on its composition. We find that PEAR would have a value lower than that of soybean meal in recent years. The value of PEAR will vary substantially based on its characteristics. PEAR could have generated algal fuel co-product credits that in recent years would have ranged between $0.95 and $2.43 per gallon of fuel produced.

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

    NASA Astrophysics Data System (ADS)

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

    2008-11-01

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

  17. Dancing Volvox: Hydrodynamic Bound States of Swimming Algae

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

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

  18. Fibrinolytic Compounds Isolated from a Brown Alga, Sargassum fulvellum

    PubMed Central

    Wu, Wenhui; Hasumi, Keiji; Peng, Hui; Hu, Xianwen; Wang, Xichang; Bao, Bin

    2009-01-01

    Two of bioactive natural products were founded in a brown alga, Sargassum fulvellum. After isolation and purification, the molecular structures of these two products were investigated by NMR spectroscopy and GC-mass spectroscopy. The two compounds were identified to be 1-O-palmitoyl-2-O-oleoyl-3-O-(α-D-glucopyranosyl) –glycerol (POGG) and 1-O-myristoyl-2-O-oleoyl-3-O-(α-D-glucopyranosyl) – glycerol (MOGG) which were obtained from Sargassum fulvellum for the first time. POGG and MOGG showed fibrinolytic activity in the reaction system of pro-u-PA and plasminogen. PMID:19597573

  19. The auxin concentration in sixteen Chinese marine algae

    NASA Astrophysics Data System (ADS)

    Han, Lijun

    2006-09-01

    The author determined the occurrence of indole-3-acetic acid in sixteen Chinese marine algae collected from the east coast of China with fluorescence spectrophotometry (FS) and wheat coleoptile bioanalysis methods (WCB). The concentration of indole-3-acetic acid (IAA) presented was from 1.1 46.9 ng/g Fw (fresh weight) with FS and 5.3 110.2 ng/g Fw with WCB. The results by the two methods were in the orders of 10-3 103 ng/g Fw reported previously from multiple references.

  20. Dancing Volvox: Hydrodynamic Bound States of Swimming Algae

    PubMed Central

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

    2013-01-01

    The spherical alga Volvox swims by means of flagella on thousands of surface somatic cells. This geometry and its large size make it a model organism for studying the fluid dynamics of multicellularity. Remarkably, when two nearby Volvox colonies swim close to a solid surface, they attract one another and can form stable bound states in which they “waltz” or “minuet” around each other. A surface-mediated hydrodynamic attraction combined with lubrication forces between spinning, bottom-heavy Volvox explains the formation, stability, and dynamics of the bound states. These phenomena are suggested to underlie observed clustering of Volvox at surfaces. PMID:19518757

  1. Multidimensional electronic spectroscopy of phycobiliproteins from cryptophyte algae

    NASA Astrophysics Data System (ADS)

    Turner, Daniel

    2011-03-01

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

  2. Turning moss into algae: prenylation targets in Physcomitrella patens.

    PubMed

    Antimisiaris, Marika F; Running, Mark P

    2014-01-01

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

  3. Multi-scale Characterization of Improved Algae Strains

    SciTech Connect

    Dale, Taraka T.

    2015-04-01

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

  4. Molecular characterization of epiphytic bacterial communities on charophycean green algae

    PubMed

    Fisher; Wilcox; Graham

    1998-11-01

    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 alpha, beta, and gamma 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.

  5. Monoclonal Antibodies Directed to Fucoidan Preparations from Brown Algae

    PubMed Central

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

    2015-01-01

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

  6. Marine algae and land plants share conserved phytochrome signaling systems

    PubMed Central

    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

    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

  7. Valorization of Rhizoclonium sp. algae via pyrolysis and catalytic pyrolysis.

    PubMed

    Casoni, Andrés I; Zunino, Josefina; Piccolo, María C; Volpe, María A

    2016-09-01

    The valorization of Rhizoclonium sp. algae through pyrolysis for obtaining bio-oils is studied in this work. The reaction is carried out at 400°C, at high contact time. The bio-oil has a practical yield of 35% and is rich in phytol. Besides, it is simpler than the corresponding to lignocellulosic biomass due to the absence of phenolic compounds. This property leads to a bio-oil relatively stable to storage. In addition, heterogeneous catalysts (Al-Fe/MCM-41, SBA-15 and Cu/SBA-15), in contact with algae during pyrolysis, are analyzed. The general trend is that the catalysts decrease the concentration of fatty alcohols and other high molecular weight products, since their mild acidity sites promote degradation reactions. Thus, the amount of light products increases upon the use of the catalysts. Particularly, acetol concentration in the bio-oils obtained from the catalytic pyrolysis with SBA-15 and Cu/SBA-15 is notably high.

  8. Feeding by coral reef mesograzers: algae or cyanobacteria?

    NASA Astrophysics Data System (ADS)

    Cruz-Rivera, Edwin; Paul, Valerie J.

    2006-11-01

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

  9. Marine algae and land plants share conserved phytochrome signaling systems

    DOE PAGES

    Duanmu, Deqiang; Bachy, Charles; Sudek, Sebastian; Wong, Chee -Hong; Jimenez, Valeria; Rockwell, Nathan C.; Martin, Shelley S.; Ngan, Chew Yee; Reistetter, Emily N.; van Baren, Marijke J.; et al

    2014-09-29

    Phytochrome photosensors control a vast gene network in streptophyte plants, acting as master regulators of diverse growth and developmental processes throughout the life cycle. In contrast with their absence in known chlorophyte algal genomes and most sequenced prasinophyte algal genomes, a phytochrome is found in Micromonas pusilla, a widely distributed marine picoprasinophyte (<2 µm cell diameter). Together with phytochromes identified from other prasinophyte lineages, we establish that prasinophyte and streptophyte phytochromes share core light-input and signaling-output domain architectures except for the loss of C-terminal response regulator receiver domains in the streptophyte phytochrome lineage. Phylogenetic reconstructions robustly support the presence ofmore » phytochrome in the common progenitor of green algae and land plants. These analyses reveal a monophyletic clade containing streptophyte, prasinophyte, cryptophyte, and glaucophyte phytochromes implying an origin in the eukaryotic ancestor of the Archaeplastida. Transcriptomic measurements reveal diurnal regulation of phytochrome and bilin chromophore biosynthetic genes in Micromonas. The expression of these genes precedes both light-mediated phytochrome redistribution from the cytoplasm to the nucleus and increased expression of photosynthesis-associated genes. Prasinophyte phytochromes perceive wavelengths of light transmitted farther through seawater than the red/far-red light sensed by land plant phytochromes. Prasinophyte phytochromes also retain light-regulated histidine kinase activity lost in the streptophyte phytochrome lineage. Our studies demonstrate that light-mediated nuclear translocation of phytochrome predates the emergence of land plants and likely represents a widespread signaling mechanism in unicellular algae.« less

  10. Marine algae and land plants share conserved phytochrome signaling systems

    SciTech Connect

    Duanmu, Deqiang; Bachy, Charles; Sudek, Sebastian; Wong, Chee -Hong; Jimenez, Valeria; Rockwell, Nathan C.; Martin, Shelley S.; Ngan, Chew Yee; Reistetter, Emily N.; van Baren, Marijke J.; Price, Dana C.; Wei, Chia -Lin; Reyes-Prieto, Adrian; Lagarias, J. Clark; Worden, Alexandra Z.

    2014-09-29

    Phytochrome photosensors control a vast gene network in streptophyte plants, acting as master regulators of diverse growth and developmental processes throughout the life cycle. In contrast with their absence in known chlorophyte algal genomes and most sequenced prasinophyte algal genomes, a phytochrome is found in Micromonas pusilla, a widely distributed marine picoprasinophyte (<2 µm cell diameter). Together with phytochromes identified from other prasinophyte lineages, we establish that prasinophyte and streptophyte phytochromes share core light-input and signaling-output domain architectures except for the loss of C-terminal response regulator receiver domains in the streptophyte phytochrome lineage. Phylogenetic reconstructions robustly support the presence of phytochrome in the common progenitor of green algae and land plants. These analyses reveal a monophyletic clade containing streptophyte, prasinophyte, cryptophyte, and glaucophyte phytochromes implying an origin in the eukaryotic ancestor of the Archaeplastida. Transcriptomic measurements reveal diurnal regulation of phytochrome and bilin chromophore biosynthetic genes in Micromonas. The expression of these genes precedes both light-mediated phytochrome redistribution from the cytoplasm to the nucleus and increased expression of photosynthesis-associated genes. Prasinophyte phytochromes perceive wavelengths of light transmitted farther through seawater than the red/far-red light sensed by land plant phytochromes. Prasinophyte phytochromes also retain light-regulated histidine kinase activity lost in the streptophyte phytochrome lineage. Our studies demonstrate that light-mediated nuclear translocation of phytochrome predates the emergence of land plants and likely represents a widespread signaling mechanism in unicellular algae.

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

    NASA Technical Reports Server (NTRS)

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

    2009-01-01

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

  12. Sulfur utilization of corals is enhanced by endosymbiotic algae.

    PubMed

    Yuyama, Ikuko; Higuchi, Tomihiko; Takei, Yoshio

    2016-09-15

    Sulfur-containing compounds are important components of all organisms, but few studies have explored sulfate utilization in corals. Our previous study found that the expression of a sulfur transporter (SLC26A11) was upregulated in the presence of Symbiodinium cells in juveniles of the reef-building coral Acropora tenuis In this study, we performed autoradiography using (35)S-labeled sulfate ions ((35)SO4  (2-)) to examine the localization and amount of incorporated radioactive sulfate in the coral tissues and symbiotic algae. Incorporated (35)SO4  (2-) was detected in symbiotic algal cells, nematocysts, ectodermal cells and calicoblast cells. The combined results of (35)S autoradiography and Alcian Blue staining showed that incorporated (35)S accumulated as sulfated glycosaminoglycans (GAGs) in the ectodermal cell layer. We also compared the relative incorporation of (35)SO4  (2-) into coral tissues and endosymbiotic algae, and their chemical fractions in dark versus light (photosynthetic) conditions. The amount of sulfur compounds, such as GAGs and lipids, generated from (35)SO4  (2-) was higher under photosynthetic conditions. Together with the upregulation of sulfate transporters by symbiosis, our results suggest that photosynthesis of algal endosymbionts contributes to the synthesis and utilization of sulfur compounds in corals.

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

    PubMed

    Stengel, Dagmar B; Connan, Solène

    2015-01-01

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

  14. Ecotoxicological effects of carbon nanomaterials on algae, fungi and plants.

    PubMed

    Basiuk, Elena V; Ochoa-Olmos, Omar E; De la Mora-Estrada, León F

    2011-04-01

    The ecotoxicological effects of carbon nanomateriales (CNMs), namely fullerenes and carbon nanotubes, on algae, fungi and plants are analyzed. In different toxicity tests, both direct and indirect effects were found. The direct effects are determined by nanomaterial chemical composition and surface reactivity, which might catalyze redox reactions in contact with organic molecules and affect respiratory processes. Some indirect effects of carbon nanoparticles (CNPs) are physical restraints or release of toxic ions. Accumulation of CNPs in photosynthetic organs provokes obstruction in stomata, foliar heating and alteration in physiological processes. The phytotoxicity studies of CNMs should be focused on determining phytotoxicity mechanisms, size distribution of CNPs in solution, uptake and translocation of nanoparticles by plants, on characterization of their physical and chemical properties in rhizosphere and on root surfaces. More studies on plants and algae, as a part of food chain, are needed to understand profoundly the toxicity and health risks of CNMs as ecotoxicological stressors. Correct and detailed physical and chemical characterization of CNMs is very important to establish the exposure conditions matching the realistic ones. Ecotoxicity experiments should include examinations of both short and long-term effects. One must take into account that real carbon nanomaterials are complex mixtures of carbon forms and metal residues of variable chemistry and particle size, and the toxicity reported may reflect these byproducts/residues/impurities rather than the primary material structure. One more recommendation is not only to focus on the inherent toxicity of nanoparticles, but also consider their possible interactions with existing environmental contaminants.

  15. Drift algae reduce foraging efficiency of juvenile flatfish

    NASA Astrophysics Data System (ADS)

    Nordström, Marie; Booth, Dale M.

    2007-11-01

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

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

    SciTech Connect

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

    1983-04-01

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

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

    PubMed

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

    2015-01-01

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

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

    PubMed

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

    2013-01-01

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

  19. Sulfur utilization of corals is enhanced by endosymbiotic algae

    PubMed Central

    Yuyama, Ikuko; Takei, Yoshio

    2016-01-01

    ABSTRACT Sulfur-containing compounds are important components of all organisms, but few studies have explored sulfate utilization in corals. Our previous study found that the expression of a sulfur transporter (SLC26A11) was upregulated in the presence of Symbiodinium cells in juveniles of the reef-building coral Acropora tenuis. In this study, we performed autoradiography using 35S-labeled sulfate ions (35SO4 2−) to examine the localization and amount of incorporated radioactive sulfate in the coral tissues and symbiotic algae. Incorporated 35SO4 2− was detected in symbiotic algal cells, nematocysts, ectodermal cells and calicoblast cells. The combined results of 35S autoradiography and Alcian Blue staining showed that incorporated 35S accumulated as sulfated glycosaminoglycans (GAGs) in the ectodermal cell layer. We also compared the relative incorporation of 35SO4 2− into coral tissues and endosymbiotic algae, and their chemical fractions in dark versus light (photosynthetic) conditions. The amount of sulfur compounds, such as GAGs and lipids, generated from 35SO4 2− was higher under photosynthetic conditions. Together with the upregulation of sulfate transporters by symbiosis, our results suggest that photosynthesis of algal endosymbionts contributes to the synthesis and utilization of sulfur compounds in corals. PMID:27493203

  20. Solar-driven hydrogen production in green algae.

    PubMed

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

    2011-01-01

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

  1. Hidden biodiversity of the extremophilic Cyanidiales red algae.

    PubMed

    Ciniglia, Claudia; Yoon, Hwan Su; Pollio, Antonino; Pinto, Gabriele; Bhattacharya, Debashish

    2004-07-01

    The Cyanidiales is a group of asexual, unicellular red algae, which thrive in acidic and high temperature conditions around hot springs. These unicellular taxa have a relatively simple morphology and are currently classified into three genera, Cyanidium, Cyanidioschyzon and Galdieria. Little is known, however, about the biodiversity of Cyanidiales, their population structure and their phylogenetic relationships. Here we used a taxonomically broadly sampled three-gene data set of plastid sequences to infer a robust phylogenetic framework for the Cyanidiales. The phylogenetic analyses support the existence of at least four distinct Cyanidiales lineages: the Galdieria spp. lineage (excluding Galdieria maxima), the Cyanidium caldarium lineage, a novel monophyletic lineage of mesophilic Cyanidium spp. and the Cyanidioschyzon merolae plus Galdieria maxima lineage. Our analyses do not support the notion of a mesophilic ancestry of the Cyanidiales and suggest that these algae were ancestrally thermo-acidotolerant. We also used environmental polymerase chain reaction (PCR) for the rbcL gene to sample Cyanidiales biodiversity at five ecologically distinct sites at Pisciarelli in the Phlegrean Fields in Italy. This analysis showed a high level of sequence divergence among Cyanidiales species and the partitioning of taxa based on environmental conditions. Our research revealed an unexpected level of genetic diversity among Cyanidiales that revises current thinking about the phylogeny and biodiversity of this group. We predict that future environmental PCR studies will significantly augment known biodiversity that we have discovered and demonstrate the Cyanidiales to be a species-rich branch of red algal evolution.

  2. Photosynthetic hydrogen and oxygen production by green algae

    SciTech Connect

    Greenbaum, E.; Lee, J.W.

    1997-12-31

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

  3. Photosynthetic Hydrogen and Oxygen Production by Green Algae

    SciTech Connect

    Greenbaum, E.; Lee, J.W.

    1999-08-22

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

  4. Biokinetic aspects of tissue-bound tritium in algae.

    PubMed

    Strack, S; Kistner, G

    1978-01-01

    For the estimate of the radiation exposure of man and for the calculation of the risk of artificial tritium from nuclear power plants, organic tissue-bound tritium is of decisive importance. In model experiments, a tritium incorporation of 61 to 71% was found from tritiated water (HTO) into organic matter of planctonic algae under under reproducible conditions and this was related to the theoretical value. In further experiments the tritium release from these high tritiated algae was of interest. Kept in darkness in tritium-free, non-sterile river water, so that autolytic processes and bacterial decomposition could occur, the concentration of HTO was measured over a period of three weeks. A relatively long half-life of tissue-bound tritium was found under various temperature conditions. Therefore it must be considered that a significant retention of tritium in biological matter has to be taken into account in a natural ecosystem. In streams into which the cooling water of a nuclear reactor is released all conditions are found already for a long turnover and cycling of artificial tritium in living organisms as well as the conditions for a favourable transport of tritium by food chains to man.

  5. Chemical mediation of coral larval settlement by crustose coralline algae

    PubMed Central

    Tebben, J.; Motti, C. A; Siboni, Nahshon; Tapiolas, D. M.; Negri, A. P.; Schupp, P. J.; Kitamura, Makoto; Hatta, Masayuki; Steinberg, P. D.; Harder, T.

    2015-01-01

    The majority of marine invertebrates produce dispersive larvae which, in order to complete their life cycles, must attach and metamorphose into benthic forms. This process, collectively referred to as settlement, is often guided by habitat-specific cues. While the sources of such cues are well known, the links between their biological activity, chemical identity, presence and quantification in situ are largely missing. Previous work on coral larval settlement in vitro has shown widespread induction by crustose coralline algae (CCA) and in particular their associated bacteria. However, we found that bacterial biofilms on CCA did not initiate ecologically realistic settlement responses in larvae of 11 hard coral species from Australia, Guam, Singapore and Japan. We instead found that algal chemical cues induce identical behavioral responses of larvae as per live CCA. We identified two classes of CCA cell wall-associated compounds – glycoglycerolipids and polysaccharides – as the main constituents of settlement inducing fractions. These algae-derived fractions induce settlement and metamorphosis at equivalent concentrations as present in CCA, both in small scale laboratory assays and under flow-through conditions, suggesting their ability to act in an ecologically relevant fashion to steer larval settlement of corals. Both compound classes were readily detected in natural samples. PMID:26042834

  6. Biotransformation of arsenic by a Yellowstone thermoacidophilic eukaryotic alga

    PubMed Central

    Qin, Jie; Lehr, Corinne R.; Yuan, Chungang; Le, X. Chris; McDermott, Timothy R.; Rosen, Barry P.

    2009-01-01

    Arsenic is the most common toxic substance in the environment, ranking first on the Superfund list of hazardous substances. It is introduced primarily from geochemical sources and is acted on biologically, creating an arsenic biogeocycle. Geothermal environments are known for their elevated arsenic content and thus provide an excellent setting in which to study microbial redox transformations of arsenic. To date, most studies of microbial communities in geothermal environments have focused on Bacteria and Archaea, with little attention to eukaryotic microorganisms. Here, we show the potential of an extremophilic eukaryotic alga of the order Cyanidiales to influence arsenic cycling at elevated temperatures. Cyanidioschyzon sp. isolate 5508 oxidized arsenite [As(III)] to arsenate [As(V)], reduced As(V) to As(III), and methylated As(III) to form trimethylarsine oxide (TMAO) and dimethylarsenate [DMAs(V)]. Two arsenic methyltransferase genes, CmarsM7 and CmarsM8, were cloned from this organism and demonstrated to confer resistance to As(III) in an arsenite hypersensitive strain of Escherichia coli. The 2 recombinant CmArsMs were purified and shown to transform As(III) into monomethylarsenite, DMAs(V), TMAO, and trimethylarsine gas, with a Topt of 60–70 °C. These studies illustrate the importance of eukaryotic microorganisms to the biogeochemical cycling of arsenic in geothermal systems, offer a molecular explanation for how these algae tolerate arsenic in their environment, and provide the characterization of algal methyltransferases. PMID:19276121

  7. Biochemical and pathogenic properties of Shewanella alga and Shewanella putrefaciens.

    PubMed

    Khashe, S; Janda, J M

    1998-03-01

    We characterized 49 strains of Shewanella spp. from clinical (n = 31) and nonhuman (n = 18) sources. Most Shewanella alga organisms (Gilardi biovar 2; Centers for Disease Control and Prevention [CDC] biotype 2) originated from clinical material (92%), failed to produce acid from carbohydrates other than D-ribose, and were biochemically and enzymatically fairly homogeneous. In contrast, Shewanella putrefaciens organisms (Gilardi biovars 1 and 3; CDC biotype 1) were more often associated with nonhuman sources (70%), were able to utilize a number of sugars (sucrose, L-arabinose, and maltose), and were found to exhibit wider variations in biochemical characteristics; three biotypes within S. putrefaciens were detected. Notable differences between the two species in enzymatic activity, determined with the API-ZYM system (bioMérieux, Hazelwood, Mo.), and cellular fatty acid profiles, determined by the MIDI system (Microbial ID Inc., Newark, Del.), were also detected. Pathogenicity studies of mice indicate that S. alga appears to be the more virulent species, possibly due to the production of a hemolytic substance.

  8. Valorization of Rhizoclonium sp. algae via pyrolysis and catalytic pyrolysis.

    PubMed

    Casoni, Andrés I; Zunino, Josefina; Piccolo, María C; Volpe, María A

    2016-09-01

    The valorization of Rhizoclonium sp. algae through pyrolysis for obtaining bio-oils is studied in this work. The reaction is carried out at 400°C, at high contact time. The bio-oil has a practical yield of 35% and is rich in phytol. Besides, it is simpler than the corresponding to lignocellulosic biomass due to the absence of phenolic compounds. This property leads to a bio-oil relatively stable to storage. In addition, heterogeneous catalysts (Al-Fe/MCM-41, SBA-15 and Cu/SBA-15), in contact with algae during pyrolysis, are analyzed. The general trend is that the catalysts decrease the concentration of fatty alcohols and other high molecular weight products, since their mild acidity sites promote degradation reactions. Thus, the amount of light products increases upon the use of the catalysts. Particularly, acetol concentration in the bio-oils obtained from the catalytic pyrolysis with SBA-15 and Cu/SBA-15 is notably high. PMID:27253478

  9. Sulfur utilization of corals is enhanced by endosymbiotic algae.

    PubMed

    Yuyama, Ikuko; Higuchi, Tomihiko; Takei, Yoshio

    2016-01-01

    Sulfur-containing compounds are important components of all organisms, but few studies have explored sulfate utilization in corals. Our previous study found that the expression of a sulfur transporter (SLC26A11) was upregulated in the presence of Symbiodinium cells in juveniles of the reef-building coral Acropora tenuis In this study, we performed autoradiography using (35)S-labeled sulfate ions ((35)SO4  (2-)) to examine the localization and amount of incorporated radioactive sulfate in the coral tissues and symbiotic algae. Incorporated (35)SO4  (2-) was detected in symbiotic algal cells, nematocysts, ectodermal cells and calicoblast cells. The combined results of (35)S autoradiography and Alcian Blue staining showed that incorporated (35)S accumulated as sulfated glycosaminoglycans (GAGs) in the ectodermal cell layer. We also compared the relative incorporation of (35)SO4  (2-) into coral tissues and endosymbiotic algae, and their chemical fractions in dark versus light (photosynthetic) conditions. The amount of sulfur compounds, such as GAGs and lipids, generated from (35)SO4  (2-) was higher under photosynthetic conditions. Together with the upregulation of sulfate transporters by symbiosis, our results suggest that photosynthesis of algal endosymbionts contributes to the synthesis and utilization of sulfur compounds in corals. PMID:27493203

  10. [Food value of the spiruline algae to man].

    PubMed

    Sautier, C; Tremolieres, J

    1975-01-01

    The acceptability of various culinary products based on the algae spirulina was tested by questionaire: formulas rich in proteins, soups, omelets, desserts. Spirulina are little appreciated in France due to offensive color, smell and taste. Tomato and chocolate are the most acceptable flavors. Lyophilisation is preferable to atomisation, and discoloration using alcohol is preferable to the acetone method. The hydrolysate obtained, having neither the smell nor the taste of algae, is excellent. Nitrogen, sodium and potassium balances were recorded in 5 undernourished subjects fed via a gastric tube. The spirulina provided respectively 15 p. 100 (1 subject), 30 p. 100 (2 subjects), and 50 p. 100 (2 subjects) of the protein ration. There were no intestinal problems. The spirulina did not modify the investigated balances. However, faecal nitrogen increased to 2.08 g (compared to control period values, 1.33 g and 1.51 g). The various coefficients: digestibility, nitrogen retention and protein utilization did not vary. In man as in animals, nitrogen retention is satisfactory, but digestibility is diminished. Uric acid did not vary in the urine, but serum values increased slightly. Ingestion of spirulina in small doses even over a long period should be tolerable in the normal subject. PMID:824995

  11. Solar-driven hydrogen production in green algae.

    PubMed

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

    2011-01-01

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

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

    PubMed

    Ma, Jun; Liu, Wei

    2002-02-01

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

  13. Functional significance of genetically different symbiotic algae Symbiodinium in a coral reef symbiosis.

    PubMed

    Loram, J E; Trapido-Rosenthal, H G; Douglas, A E

    2007-11-01

    The giant sea anemone Condylactis gigantea associates with members of two clades of the dinoflagellate alga Symbiodinium, either singly or in mixed infection, as revealed by clade-specific quantitative polymerase chain reaction of large subunit ribosomal DNA. To explore the functional significance of this molecular variation, the fate of photosynthetically fixed carbon was investigated by (14)C radiotracer experiments. Symbioses with algae of clades A and B released ca. 30-40% of fixed carbon to the animal tissues. Incorporation into the lipid fraction and the low molecular weight fraction dominated by amino acids was significantly higher in symbioses with algae of clade A than of clade B, suggesting that the genetically different algae in C. gigantea are not functionally equivalent. Symbioses with mixed infections yielded intermediate values, such that this functional trait of the symbiosis can be predicted from the traits of the contributing algae. Coral and sea anemone symbioses with Symbiodinium break down at elevated temperature, a process known as 'coral bleaching'. The functional response of the C. gigantea symbiosis to heat stress varied between the algae of clades A and B, with particularly depressed incorporation of photosynthetic carbon into lipid of the clade B algae, which are more susceptible to high temperature than the algae of clade A. This study provides a first exploration of how the core symbiotic function of photosynthate transfer to the host varies with the genotype of Symbiodinium, an algal symbiont which underpins corals and, hence, coral reef ecosystems. PMID:17868294

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

    PubMed Central

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

    2012-01-01

    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

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

    PubMed Central

    Jantzen, Carin; Kremb, Stephan Georg

    2014-01-01

    Many coral reefs in the Caribbean experienced substantial changes in their benthic community composition during the last decades. This often resulted in phase shifts from scleractinian coral dominance to that by other benthic invertebrate or algae. However, knowledge about how the related role of coral-algae contacts may negatively affect corals is scarce. Therefore, benthic community composition, abundance of algae grazers, and the abundance and character of coral-algae contacts were assessed in situ at 13 Belizean reef sites distributed along a distance gradient to the Belizean mainland (12–70 km): Mesoamerican Barrier Reef (inshore), Turneffe Atoll (inner and outer midshore), and Lighthouse Reef (offshore). In situ surveys revealed significantly higher benthic cover by scleractinian corals at the remote Lighthouse Reef (26–29%) when compared to the other sites (4–19%). The abundance of herbivorous fish and the sea urchin Diadema antillarum significantly increased towards the offshore reef sites, while the occurrence of direct coral-algae contacts consequently increased significantly with decreasing distance to shore. About 60% of these algae contacts were harmful (exhibiting coral tissue damage, pigmentation change, or overgrowth) for corals (mainly genera Orbicella and Agaricia), particularly when filamentous turf algae were involved. These findings provide support to the hypothesis that (turf) algae-mediated coral damage occurs in Belizean coastal, near-shore coral reefs. PMID:25276504

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

    PubMed

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

    2014-01-01

    Many coral reefs in the Caribbean experienced substantial changes in their benthic community composition during the last decades. This often resulted in phase shifts from scleractinian coral dominance to that by other benthic invertebrate or algae. However, knowledge about how the related role of coral-algae contacts may negatively affect corals is scarce. Therefore, benthic community composition, abundance of algae grazers, and the abundance and character of coral-algae contacts were assessed in situ at 13 Belizean reef sites distributed along a distance gradient to the Belizean mainland (12-70 km): Mesoamerican Barrier Reef (inshore), Turneffe Atoll (inner and outer midshore), and Lighthouse Reef (offshore). In situ surveys revealed significantly higher benthic cover by scleractinian corals at the remote Lighthouse Reef (26-29%) when compared to the other sites (4-19%). The abundance of herbivorous fish and the sea urchin Diadema antillarum significantly increased towards the offshore reef sites, while the occurrence of direct coral-algae contacts consequently increased significantly with decreasing distance to shore. About 60% of these algae contacts were harmful (exhibiting coral tissue damage, pigmentation change, or overgrowth) for corals (mainly genera Orbicella and Agaricia), particularly when filamentous turf algae were involved. These findings provide support to the hypothesis that (turf) algae-mediated coral damage occurs in Belizean coastal, near-shore coral reefs. PMID:25276504

  17. Competitive interactions between corals and turf algae depend on coral colony form.

    PubMed

    Swierts, Thomas; Vermeij, Mark Ja

    2016-01-01

    Turf algae are becoming more abundant on coral reefs worldwide, but their effects on other benthic organisms remain poorly described. To describe the general characteristics of competitive interactions between corals and turf algae, we determined the occurrence and outcomes of coral-turf algal interactions among different coral growth forms (branching, upright, massive, encrusting, plating, and solitary) on a shallow reef in Vietnam. In total, the amount of turf algal interaction, i.e., the proportion of the coral boundary directly bordering turf algae, was quantified for 1,276 coral colonies belonging to 27 genera and the putative outcome of each interaction was noted. The amount of turf algal interaction and the outcome of these interactions differed predictably among the six growth forms. Encrusting corals interacted most often with turf algae, but also competed most successfully against turf algae. The opposite was observed for branching corals, which rarely interacted with turf algae and rarely won these competitive interactions. Including all other growth forms, a positive relationship was found between the amount of competitive interactions with neighboring turf algae and the percentage of such interaction won by the coral. This growth form dependent ability to outcompete turf algae was not only observed among coral species, but also among different growth forms in morphologically plastic coral genera (Acropora, Favia, Favites, Montastrea, Montipora, Porites) illustrating the general nature of this relationship. PMID:27190707

  18. 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...

  19. Competitive interactions between corals and turf algae depend on coral colony form

    PubMed Central

    Vermeij, Mark JA

    2016-01-01

    Turf algae are becoming more abundant on coral reefs worldwide, but their effects on other benthic organisms remain poorly described. To describe the general characteristics of competitive interactions between corals and turf algae, we determined the occurrence and outcomes of coral–turf algal interactions among different coral growth forms (branching, upright, massive, encrusting, plating, and solitary) on a shallow reef in Vietnam. In total, the amount of turf algal interaction, i.e., the proportion of the coral boundary directly bordering turf algae, was quantified for 1,276 coral colonies belonging to 27 genera and the putative outcome of each interaction was noted. The amount of turf algal interaction and the outcome of these interactions differed predictably among the six growth forms. Encrusting corals interacted most often with turf algae, but also competed most successfully against turf algae. The opposite was observed for branching corals, which rarely interacted with turf algae and rarely won these competitive interactions. Including all other growth forms, a positive relationship was found between the amount of competitive interactions with neighboring turf algae and the percentage of such interaction won by the coral. This growth form dependent ability to outcompete turf algae was not only observed among coral species, but also among different growth forms in morphologically plastic coral genera (Acropora, Favia, Favites, Montastrea, Montipora, Porites) illustrating the general nature of this relationship. PMID:27190707

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

    PubMed

    Oguchi, M; Otsubo, K; Nitta, K; Shimada, A; Fujii, S; Koyano, T; Miki, K

    1989-01-01

    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. (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 quantity 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.

  1. Biliproteins and phycobilisomes from cyanobacteria and red algae at the extremes of habitat.

    PubMed

    Samsonoff, W A; MacColl, R

    2001-12-01

    This review considers the properties of biliproteins from cyanobacteria and red algae that grow in extreme habitats. Three situations are presented: cyanobacteria that grow at high temperatures; a red alga that grows in acidic conditions at high temperature; and an Antarctic red alga that grows in the cold in dim light conditions. In particular, the properties of their biliproteins are compared to those from organisms from more usual environments. C-phycocyanins from two cyanobacteria able to grow at high temperatures are found to differ in their stabilities when compared to C-phycocyanin from mesophilic algae. They differ in opposite ways, however. One is more stable to dissociation than the mesophilic protein, and the other is more easily dissociated at low temperatures. The thermophilic proteins resist thermal denaturation much better than the mesophilic proteins. The most thermophilic cyanobacterium has a C-phycocyanin with a unique blue-shifted absorption maximum which does not appear to be part of the adaptation of the cyanobacterium to high temperature. The C-phycocyanin from the high-temperature red alga is able to resist dissociation better than mesophilic C-phycocyanins. Electron micrographs show the phycobilisomes of these algae. The Antarctic alga grows under ice at some distance down the water column. Its R-phycoerythrin has a novel absorption spectrum that gives the alga an improved ability to harvest blue light. This may enhance its survival in its light-deprived habitat.

  2. Influence of Relative Humidity on AC Corona Discharge from Algae Attached on the Silicone Rubber

    NASA Astrophysics Data System (ADS)

    Sato, Daisuke; Hara, Yoshiaki; Kokufu, Morihide; Higashiyama, Yoshio

    To make clear the influence of algae growth at the surface of a polymer insulator in a practical transmission line, the characteristics of ac corona discharge from an aggregate algae particle were investigated. The aggregate algae particle was made of Protococcus viridis. Corona onset voltage from an aggregate algae particle was decreased as relative humidity increased. Under the condition of relatively higher relative humidity, luminous channel of corona discharge became more strongly and the number of corona pulses in the current waveform was increased. For an aggregate algae particle contaminated with sea salt including MgCl2, corona onset voltage decreased drastically at relative humidity above 40%. This property would result from deliquescence of MgCl2. Corona discharge was strongly affected by existence of MgCl2 in an aggregate algae particle. Surface resistance of algae attached to the surface of the silicone rubber sheet decreased in fourth figures for relative humidity from 20 to 90%. Therefore, the existence of algae on the polymer insulator inevitably affects the electric property and the surface property of the polymer insulator.

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

    PubMed

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

    2012-04-22

    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.

  4. Composition, mineral profiles and characterization of the ash component in 12 algae samples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Algae have been used as food, feed, fertilizer, and lately as an attractive biomass for renewable energy. Key advantages of algae include prolific growth rates, the ability to grow on lands that are marginal for other agricultural purposes, and the ability to clean up water resources with excess nu...

  5. Spatiotemporal associations of reservoir nutrient characteristics and the invasive, harmful alga Prymnesium parvum in West Texas

    USGS Publications Warehouse

    VanLandeghem, Matthew M.; Farooqi, Mukhtar; Southard, Greg M.; Patino, Reynaldo

    2015-01-01

    Golden alga (Prymnesium parvum) is a harmful alga that has caused ecological and economic harm in freshwater and marine systems worldwide. In inland systems of North America, toxic blooms have nearly eliminated fish populations in some systems. Modifying nutrient profiles through alterations to land or water use may be a viable alternative for golden alga control in reservoirs. The main objective of this study was to improve our understanding of the nutrient dynamics that influence golden alga bloom formation and toxicity in west Texas reservoirs. We examined eight sites in the Upper Colorado River basin, Texas: three impacted reservoirs that have experienced repeated golden alga blooms; two reference reservoirs where golden alga is present but nontoxic; and three confluence sites downstream of the impacted and reference sites. Total, inorganic, and organic nitrogen and phosphorus and their ratios were quantified monthly along with golden alga abundance and ichthyotoxicity between December 2010 and July 2011. Blooms persisted for several months at the impacted sites, which were characterized by high organic nitrogen and low inorganic nitrogen. At impacted sites, abundance was positively associated with inorganic phosphorus and bloom termination coincided with increases in inorganic nitrogen and decreases in inorganic phosphorus in late spring. Management of both inorganic and organic forms of nutrients may create conditions in reservoirs unfavorable to golden alga.

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

    PubMed

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

    2014-01-01

    Many coral reefs in the Caribbean experienced substantial changes in their benthic community composition during the last decades. This often resulted in phase shifts from scleractinian coral dominance to that by other benthic invertebrate or algae. However, knowledge about how the related role of coral-algae contacts may negatively affect corals is scarce. Therefore, benthic community composition, abundance of algae grazers, and the abundance and character of coral-algae contacts were assessed in situ at 13 Belizean reef sites distributed along a distance gradient to the Belizean mainland (12-70 km): Mesoamerican Barrier Reef (inshore), Turneffe Atoll (inner and outer midshore), and Lighthouse Reef (offshore). In situ surveys revealed significantly higher benthic cover by scleractinian corals at the remote Lighthouse Reef (26-29%) when compared to the other sites (4-19%). The abundance of herbivorous fish and the sea urchin Diadema antillarum significantly increased towards the offshore reef sites, while the occurrence of direct coral-algae contacts consequently increased significantly with decreasing distance to shore. About 60% of these algae contacts were harmful (exhibiting coral tissue damage, pigmentation change, or overgrowth) for corals (mainly genera Orbicella and Agaricia), particularly when filamentous turf algae were involved. These findings provide support to the hypothesis that (turf) algae-mediated coral damage occurs in Belizean coastal, near-shore coral reefs.

  7. Competitive interactions between corals and turf algae depend on coral colony form.

    PubMed

    Swierts, Thomas; Vermeij, Mark Ja

    2016-01-01

    Turf algae are becoming more abundant on coral reefs worldwide, but their effects on other benthic organisms remain poorly described. To describe the general characteristics of competitive interactions between corals and turf algae, we determined the occurrence and outcomes of coral-turf algal interactions among different coral growth forms (branching, upright, massive, encrusting, plating, and solitary) on a shallow reef in Vietnam. In total, the amount of turf algal interaction, i.e., the proportion of the coral boundary directly bordering turf algae, was quantified for 1,276 coral colonies belonging to 27 genera and the putative outcome of each interaction was noted. The amount of turf algal interaction and the outcome of these interactions differed predictably among the six growth forms. Encrusting corals interacted most often with turf algae, but also competed most successfully against turf algae. The opposite was observed for branching corals, which rarely interacted with turf algae and rarely won these competitive interactions. Including all other growth forms, a positive relationship was found between the amount of competitive interactions with neighboring turf algae and the percentage of such interaction won by the coral. This growth form dependent ability to outcompete turf algae was not only observed among coral species, but also among different growth forms in morphologically plastic coral genera (Acropora, Favia, Favites, Montastrea, Montipora, Porites) illustrating the general nature of this relationship.

  8. MONITORING CHLOROPHYLL-A AS A MEASURE OF ALGAE IN LAKE TEXOMA MARINAS

    EPA Science Inventory

    Lake water quality in five marinas on Lake Texoma was determined over a two year period. Quality parameters were methyl tert-butyl ether, nitrate, some metals, fecal coliform and algae. Common blue-green algae can produce a toxin harmful to other aquatic organisms and humans. ...

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

    PubMed

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

    2011-01-01

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

  10. Computational Visual Stress Level Analysis of Calcareous Algae Exposed to Sedimentation

    PubMed Central

    Nilssen, Ingunn; Eide, Ingvar; de Oliveira Figueiredo, Marcia Abreu; de Souza Tâmega, Frederico Tapajós; Nattkemper, Tim W.

    2016-01-01

    This paper presents a machine learning based approach for analyses of photos collected from laboratory experiments conducted to assess the potential impact of water-based drill cuttings on deep-water rhodolith-forming calcareous algae. This pilot study uses imaging technology to quantify and monitor the stress levels of the calcareous algae Mesophyllum engelhartii (Foslie) Adey caused by various degrees of light exposure, flow intensity and amount of sediment. A machine learning based algorithm was applied to assess the temporal variation of the calcareous algae size (∼ mass) and color automatically. Measured size and color were correlated to the photosynthetic efficiency (maximum quantum yield of charge separation in photosystem II, ΦPSIImax) and degree of sediment coverage using multivariate regression. The multivariate regression showed correlations between time and calcareous algae sizes, as well as correlations between fluorescence and calcareous algae colors. PMID:27285611

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

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

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

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

    PubMed

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

    2014-01-01

    This study presents a techno-economic assessment of algae-derived biodiesel under economic and technical uncertainties associated with the development of algal biorefineries. A global sensitivity analysis was performed using a High Dimensional Model Representation (HDMR) method. It was found that, considering reasonable ranges over which each parameter can vary, the sensitivity of the biodiesel production cost to the key input parameters decreases in the following order: algae oil content>algae annual productivity per unit area>plant production capacity>carbon price increase rate. It was also found that the Return on Investment (ROI) is highly sensitive to the algae oil content, and to a lesser extent to the algae annual productivity, crude oil price and price increase rate, plant production capacity, and carbon price increase rate. For a large scale plant (100,000 tonnes of biodiesel per year) the production cost of biodiesel is likely to be £0.8-1.6 per kg.

  13. Computational Visual Stress Level Analysis of Calcareous Algae Exposed to Sedimentation.

    PubMed

    Osterloff, Jonas; Nilssen, Ingunn; Eide, Ingvar; de Oliveira Figueiredo, Marcia Abreu; de Souza Tâmega, Frederico Tapajós; Nattkemper, Tim W

    2016-01-01

    This paper presents a machine learning based approach for analyses of photos collected from laboratory experiments conducted to assess the potential impact of water-based drill cuttings on deep-water rhodolith-forming calcareous algae. This pilot study uses imaging technology to quantify and monitor the stress levels of the calcareous algae Mesophyllum engelhartii (Foslie) Adey caused by various degrees of light exposure, flow intensity and amount of sediment. A machine learning based algorithm was applied to assess the temporal variation of the calcareous algae size (∼ mass) and color automatically. Measured size and color were correlated to the photosynthetic efficiency (maximum quantum yield of charge separation in photosystem II, [Formula: see text]) and degree of sediment coverage using multivariate regression. The multivariate regression showed correlations between time and calcareous algae sizes, as well as correlations between fluorescence and calcareous algae colors.

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

    PubMed Central

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

    2015-01-01

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

  15. The Effects of Nutrient Enrichment and Herbivore Abundance on the Ability of Turf Algae to Overgrow Coral in the Caribbean

    PubMed Central

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

    2010-01-01

    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

  16. High iron content and bioavailability in humans from four species of marine algae.

    PubMed

    García-Casal, Maria N; Pereira, Ana C; Leets, Irene; Ramírez, José; Quiroga, Maria F

    2007-12-01

    Searching for economical, nonconventional sources of iron is important in underdeveloped countries to combat iron deficiency and anemia. Our objective was to study iron, vitamin C, and phytic acid composition and also iron bioavailability from 4 species of marine algae included in a rice-based meal. Marine algae (Ulva sp, Sargassum sp, Porphyra sp, and Gracilariopsis sp) were analyzed for monthly variations in iron and for ascorbic acid and phytic acid concentrations. A total of 96 subjects received rice-based meals containing the 4 species of marine algae in different proportions, raw or cooked. All meals contained radioactive iron. Absorption was evaluated by calculating the radioactive iron incorporation in subjects' blood. Iron concentrations in algae were high and varied widely, depending on the species and time of year. The highest iron concentrations were found in Sargassum (157 mg/100 g) and Gracilariopsis (196 mg/100 g). Phytates were not detected in the algae and ascorbic acid concentration fluctuated between 38 microg/g dry weight (Ulva) and 362 microg/g dry weight (Sargassum). Algae significantly increased iron absorption in rice-based meals. Cooking did not affect iron absorption compared with raw algae. Results indicate that Ulva sp, Sargassum sp, Porphyra sp, and Gracilariopsis sp are good sources of ascorbic acid and bioavailable iron. The percentage of iron absorption was similar among all algae tested, although Sargassum sp resulted in the highest iron intake. Based on these results, and on the high reproduction rates of algae during certain seasons, promoting algae consumption in some countries could help to improve iron nutrition.

  17. 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...

  18. Characterization of phosphorus forms in lake macrophytes and algae by solution 31P nuclear magnetic resonance spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aquatic macrophytes and algae are important sources of phosphorus (P) in the lake environment that cause blooms of algae under certain biogeochemical conditions. However, the knowledge of forms of P in these plants and algae and their contribution to internal loads of lake P is very limited. Witho...

  19. Convergence of joint mechanics in independently evolving, articulated coralline algae.

    PubMed

    Janot, Kyra; Martone, Patrick T

    2016-02-01

    Flexible joints are a key innovation in the evolution of upright coralline algae. These structures have evolved in parallel at least three separate times, allowing the otherwise rigid, calcified thalli of upright corallines to achieve flexibility when subjected to hydrodynamic stress. As all bending occurs at the joints, stress is amplified, which necessitates that joints be made of material that is both extensible and strong. Data presented here indicate that coralline joints are in fact often stronger and more extensible, as well as tougher, than fleshy seaweed tissues. Corallinoids are particularly strong and tough, which is largely due to the presence of secondary cell walls that strengthen the joint tissue without adding bulk to the joint itself. Cell wall thickness is shown to be a large contributing factor to strength across all groups, with the exception of the corallinoid Cheilosporum sagittatum, which likely possesses distinct chemical composition in its walls to increase strength beyond that of all other species tested.

  20. Toxicity testing with the marine algae, Symbiodinium kawagutii (Dinophyceae)

    SciTech Connect

    Gorrie, J.R.; Bidwell, J.R.; Rippingale, R.J.

    1994-12-31

    The dinoflagellate, Symbiodinium kawagutii, is among the algal taxa which exist in symbiosis with a range of marine invertebrates. S. kawagutii is commonly found in association with the Hawaiian stony coral, Montipora verrucosa. The algae has been successfully cultured in the laboratory using a common marine algal growth media (Guillard f/2), and sufficient cell densities were achieved in a 96-hr bioassay to allow statistical evaluation of toxicity data. A 96-hr EC{sub 50} of 6.47 mg/L (95% C.I.: 3.54--9.88 mg/L) was calculated after exposure to potassium dichromate. Wide distribution of the coral host and ecological importance of the symbiosis make S. kawagutii an excellent candidate species for hazard evaluation in tropical marine ecosystems. Continuing research will seek to further refine the bioassay, including the use of a microplate technique for more rapid testing.

  1. Self-deconstructing algae biomass as feedstock for transportation fuels

    SciTech Connect

    Davis, Ryan Wesley

    2014-09-01

    The potential for producing biofuels from algae has generated much excitement based on projections of large oil yields with relatively little land use. However, numerous technical challenges remain for achieving market parity with conventional non-renewable liquid fuel sources. Among these challenges, the energy intensive requirements of traditional cell rupture, lipid extraction, and residuals fractioning of microalgae biomass have posed significant challenges to the nascent field of algal biotechnology. Our novel approach to address these problems was to employ low cost solution-state methods and biochemical engineering to eliminate the need for extensive hardware and energy intensive methods for cell rupture, carbohydrate and protein solubilization and hydrolysis, and fuel product recovery using consolidated bioprocessing strategies. The outcome of the biochemical deconstruction and conversion process consists of an emulsion of algal lipids and mixed alcohol products from carbohydrate and protein fermentation for co-extraction or in situ transesterification.

  2. Alternate-Fueled Flight: Halophytes, Algae, Bio-, and Synthetic Fuels

    NASA Technical Reports Server (NTRS)

    Hendricks, R. C.

    2007-01-01

    Synthetic and biomass fueling are now considered to be near-term aviation alternate fueling. The major impediment is a secure sustainable supply of these fuels at reasonable cost. However, biomass fueling raises major concerns related to uses of common food crops and grasses (some also called "weeds") for processing into aviation fuels. These issues are addressed, and then halophytes and algae are shown to be better suited as sources of aerospace fuels and transportation fueling in general. Some of the history related to alternate fuels use is provided as a guideline for current and planned alternate fuels testing (ground and flight) with emphasis on biofuel blends. It is also noted that lessons learned from terrestrial fueling are applicable to space missions. These materials represent an update and additions to the Workshop on Alternate Fueling Sustainable Supply and Halophyte Summit at Twinsburg, OH, Oct. 17 to 18, 2007 (ref. 1).

  3. Alternate-Fueled Flight: Halophytes, Algae, Bio-, and Synthetic Fuels

    NASA Technical Reports Server (NTRS)

    Hendricks, R. C.

    2012-01-01

    Synthetic and biomass fueling are now considered to be near-term aviation alternate fueling. The major impediment is a secure sustainable supply of these fuels at reasonable cost. However, biomass fueling raises major concerns related to uses of common food crops and grasses (some also called "weeds") for processing into aviation fuels. These issues are addressed, and then halophytes and algae are shown to be better suited as sources of aerospace fuels and transportation fueling in general. Some of the history related to alternate fuels use is provided as a guideline for current and planned alternate fuels testing (ground and flight) with emphasis on biofuel blends. It is also noted that lessons learned from terrestrial fueling are applicable to space missions. These materials represent an update (to 2009) and additions to the Workshop on Alternate Fueling Sustainable Supply and Halophyte Summit at Twinsburg, Ohio, October 17 to 18, 2007.

  4. Free radical production by the red tide alga, Chattonella antiqua.

    PubMed

    Shimada, M; Akagi, N; Nakai, Y; Goto, H; Watanabe, M; Watanabe, H; Nakanishi, M; Yoshimatsu, S; Ono, C

    1991-08-01

    The red tide alga, Chattonella antiqua, was found to show a strong chemiluminescence, using luminol as the reagent, when exposed to ultraviolet irradiation. This luminescence was completely inhibited by ascorbate or catalase, suggesting that hydrogen peroxide was generated by the plankton. Red tide cells exposed to fish gill mucus from young yellowtail resulted in the release of a large number of mucocysts and a weak luminosity, and showed a strong reduction of cytochrome c in the medium. Therefore, the discharge of mucocysts from the red tide, induced by the presence of gill mucus, may be accompanied by the release of active oxygen species. The active oxygen may be involved in depolymerization of mucus glycoproteins from the gill lamellae.

  5. Genomic insights from the oleaginous model alga Nannochloropsis gaditana.

    PubMed

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

    2013-01-01

    Nannochloropsis species have emerged as leading phototrophic microorganisms for the production of biofuels. Several isolates produce large quantities of triacylglycerols, grow rapidly, and can be cultivated at industrial scales. Recently, the mitochondrial, plastid and nuclear genomes of Nannochloropsis gaditana were sequenced. Genomic interrogation revealed several key features that likely facilitate the oleaginous phenotype observed in Nannochloropsis, including an over-representation of genes involved in lipid biosynthesis. Here we present additional analyses on gene orientation, vitamin B12 requiring enzymes, the acetyl-CoA metabolic node, and codon usage in N. gaditana. Nuclear genome transformation methods are established with exogenous DNA integration occurring via either random incorporation or by homologous recombination, making Nannochloropsis amenable to both forward and reverse genetic engineering. Completion of a draft genomic sequence, establishment of transformation techniques, and robust outdoor growth properties have positioned Nannochloropsis as a new model alga with significant potential for further development into an integrated photons-to-fuel production platform. PMID:22922732

  6. Amidic and acetonic cryoprotectants improve cryopreservation of volvocine green algae.

    PubMed

    Nakazawa, A; Nishii, I

    2012-01-01

    A number of volvocalean green algae species were subjected to a two-step cryopreservation protocol with various cryoprotectants. Potential cryoprotectants were methanol (DMSO), N,N-dimethylformamide (DMF), N,N-dimethylacetamide, N-methylformamide, and hydroxyacetone (HA). We confirmed prior reports that MeOH was effective for cryopreserving Chlamydomonas, but did not work well for larger volvocaleans such as Volvox. In contrast, DMF and HA were effective for both unicellular and multicellular representatives. When we used a cold-inducible transposon to probe Southern blots of Volvox DNA samples taken before and after storage for one month in LN, we could detect no differences, indicating that the genome had remained relatively stable and that the transposon had not been induced by the cryopreservation procedure. We believe these methods will facilitate long-term storage of several volvocine algal species, including Volvox strains harboring transposon-induced mutations of developmental interest. PMID:22825787

  7. Simultaneous coupling of phototaxis and electrotaxis in Volvox algae.

    PubMed

    Hayashi, Yoshikatsu; Sugawara, Ken

    2014-04-01

    In nature, living creatures are affected by several stimuli simultaneously. The response of living creatures to stimuli is called taxis. In order to reveal the principles of taxis behavior in response to complex stimuli, we simultaneously applied photostimulation and electric stimulation perpendicularly to a Volvox algae solution. The probability distribution of the swimming direction showed that a large population of swimming cells moved in a direction that was the result of the composition of phototaxis and electrotaxis. More surprisingly, we uncovered the coupling of signs of taxis, i.e., coupling of phototaxis and electrotaxis induced positive electrotaxis, which did not emerge in the single stimulation experiments. We qualitatively explained the coupling of taxis based on the polarization of the swimming cells induced by the simultaneous photo- and electric stimulation. PMID:24827285

  8. Simultaneous coupling of phototaxis and electrotaxis in Volvox algae

    NASA Astrophysics Data System (ADS)

    Hayashi, Yoshikatsu; Sugawara, Ken

    2014-04-01

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

  9. Gas exchange of algae. IV. Reliability of Chlorella pyrenoidosa.

    PubMed

    Ammann, E C; Fraser-Smith, A

    1968-05-01

    A single culture of Chlorella pyrenoidosa (700 ml) was grown continuously under uniform environmental conditions for a period of 11 months. During this time, the culture remained uncontaminated and its oxygen production, carbon dioxide consumption, and photosynthetic quotient (PQ = CO(2)/O(2)) were monitored on a 24-hr basis. The gas exchange characteristics of the alga were found to be extremely reliable; the average oxygen production was 1.21 +/- 0.03 ml per min, the carbon dioxide consumption was 1.09 +/- 0.03 ml per min, and the PQ was 0.90 +/- 0.01 when changes in both lamp intensity and instrument accuracy were taken into consideration. Such long-term dependability in the production of oxygen, consumption of carbon dioxide, and maintenance of a uniform PQ warrants the use of C. pyrenoidosa in a regenerative life support system for space travel.

  10. Enhanced genetic tools for engineering multigene traits into green algae.

    PubMed

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

    2014-01-01

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

  11. A new ketosteroid from red alga Acanthophora spicifera

    NASA Astrophysics Data System (ADS)

    Shi, Dayong; Guo, Shuju; Fan, Xiao

    2011-05-01

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

  12. Ozonation of algae and odor causing substances in eutrophic waters.

    PubMed

    Huang, Winn-Jung; Cheng, Bai-Ling; Hu, Su-Kind; Chu, Chenghwa

    2006-01-01

    Consumers generally concern taste and odor in drinking water. In the Southern Taiwan, more than 5,000,000 people are suffered from earth/musty odor in drinking water, especially in the summer. Thus, ozonation of geosmin (GSM), 2-methylisoborneol (2-MIB), and 2-furfural (2-FF) in eutrophic surface waters has been studied in the present work. Experimentally, it was found that the water contained high dissolved organic carbon (DOC), humic substances, and specific ultraviolet absorbance (SUVA) resulting the highly ozone (O3) demand. The natural organic matters (NOM) in the waters had a significant effect on the ozonation of GSM, 2-MIB and 2-FF. Their destruction rates were increased with high contents of aromatics, phenolics, and SUVAs. In addition, during ozonation of raw waters, O3 and OH. played an important role in destruction of algae cells and caused excretion of extracellular organic matter (EOM) to the bulk phase. PMID:16835113

  13. The effect of low temperature on Antarctic endolithic green algae.

    PubMed

    Meyer, M A; Huang G-H; Morris, G J; Friedmann, E I

    1988-01-01

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

  14. Genomic insights from the oleaginous model alga Nannochloropsis gaditana

    PubMed Central

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

    2013-01-01

    Nannochloropsis species have emerged as leading phototrophic microorganisms for the production of biofuels. Several isolates produce large quantities of triacylglycerols, grow rapidly, and can be cultivated at industrial scales. Recently, the mitochondrial, plastid and nuclear genomes of Nannochloropsis gaditana were sequenced. Genomic interrogation revealed several key features that likely facilitate the oleaginous phenotype observed in Nannochloropsis, including an over-representation of genes involved in lipid biosynthesis. Here we present additional analyses on gene orientation, vitamin B12 requiring enzymes, the acetyl-CoA metabolic node, and codon usage in N. gaditana. Nuclear genome transformation methods are established with exogenous DNA integration occurring via either random incorporation or by homologous recombination, making Nannochloropsis amenable to both forward and reverse genetic engineering. Completion of a draft genomic sequence, establishment of transformation techniques, and robust outdoor growth properties have positioned Nannochloropsis as a new model alga with significant potential for further development into an integrated photons-to-fuel production platform. PMID:22922732

  15. The effect of low temperature on Antarctic endolithic green algae

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

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

  16. Testing an Algae-Based Air-Regeneration System

    NASA Technical Reports Server (NTRS)

    Nienow, James

    1998-01-01

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

  17. Developing a Forward Model of Encrusting Coralline Algae

    NASA Astrophysics Data System (ADS)

    Ng, J.; Williams, B.; Thompson, D. M.; Halfar, J.

    2014-12-01

    Climate proxy data has traditionally been interpreted through inverse models, which extract physical climate variables from proxy variables. This approach assumes stationarity of the proxy-climate relationship, typically reduces climate signal to a single variable, and requires extensive observational records. In contrast, forward models reverse the relationship, simulating proxy variables from physical climate variables for comparison to observed proxy variables. Since this approach accounts for multiple climate variables and avoids stationarity issues, forward models have been developed for several climate proxies, including tree ring width and oxygen stable isotopes (δ18O) of corals. Here we develop a basic forward model for the climate archive coralline alga Clathromorphum sp.This long-lived alga grows in mid-to-high latitude regions and forms a solid calcite skeleton with annual growth bands similar to those of trees and tropical corals. Sub-annually resolved δ18O in annual growth bands (δ18Ospec) provide a record of local environmental and climatic factors, notably sea surface temperature (SST) and sea water oxygen stable isotopes (δ18Osw). We model Clathromorphum δ18Ospec in the Aleutian islands from gridded SST and δ18Osw of the growing season from 1960 to 2004. The strongest climate signal is observed in July, likely due to suppressed growth in other months. Initial results suggest no influence of growth rate on the fractionation of oxygen isotopes and indicate that δ18Ospec anomalies are significantly correlated with summer SST anomalies. We run this forward model with observed SST and δ18Osw and compare the resulting simulated δ18Ospec with that measured in live-collected specimens. This foundational model may be adapted to other regions and modified to include other variables influencing coralline isotope records, such as light availability and ice coverage.

  18. The cellulose synthase superfamily in fully sequenced plants and algae

    PubMed Central

    2009-01-01

    Background The cellulose synthase superfamily has been classified into nine cellulose synthase-like (Csl) families and one cellulose synthase (CesA) family. The Csl families have been proposed to be involved in the synthesis of the backbones of hemicelluloses of plant cell walls. With 17 plant and algal genomes fully sequenced, we sought to conduct a genome-wide and systematic investigation of this superfamily through in-depth phylogenetic analyses. Results A single-copy gene is found in the six chlorophyte green algae, which is most closely related to the CslA and CslC families that are present in the seven land plants investigated in our analyses. Six proteins from poplar, grape and sorghum form a distinct family (CslJ), providing further support for the conclusions from two recent studies. CslB/E/G/H/J families have evolved significantly more rapidly than their widely distributed relatives, and tend to have intragenomic duplications, in particular in the grape genome. Conclusion Our data suggest that the CslA and CslC families originated through an ancient gene duplication event in land plants. We speculate that the single-copy Csl gene in green algae may encode a mannan synthase. We confirm that the rest of the Csl families have a different evolutionary origin than CslA and CslC, and have proposed a model for the divergence order among them. Our study provides new insights about the evolution of this important gene family in plants. PMID:19646250

  19. Effect of Alexandrium tamarense on three bloom-forming algae

    NASA Astrophysics Data System (ADS)

    Yin, Juan; Xie, Jin; Yang, Weidong; Li, Hongye; Liu, Jiesheng

    2010-07-01

    We investigated the allelopathic properties of Alexandrium tamarense (Laboar) Balech on the growth of Prorocentrum donghaiense Lu, Chattonella marina (Subrahmanyan) Hara et Chihara and Heterosigma akashiwo (Hada) Hada in a laboratory experiment. We examined the growth of A. tamarense, C. marina, P. donghaiense and H. Akashiwo in co-cultures and the effect of filtrates from A. tamarense cultures in various growth phases, on the three harmful algal bloom (HAB)-forming algae. In co-cultures with A. tamarense, both C. marina and H. akashiwo were dramatically suppressed at high cell densities; in contrast, the growth of P. donghaiense varied in different inoculative ratios of A. tamarense and P. donghaiense. When the ratio was 1:1 ( P. donghaiense: A. tamarense), growth of P. donghaiense was inhibited considerably, while the growth of P. donghaiense was almost the same as that of the control when the ratio was 9:1. The growth difference of P. donghaiense, C. marina and H. akashiwo when co-cultured with A. tamarense indicated that the allelopathic effect may be one of the important factors in algal competition and phytoplankton succession involving A. tamarense. In addition, the filtrate from A. tamarense culture had negative impacts on these three HAB algae, and such inhibition varied with different growth phases of A. tamarense in parallel with reported values of PSP toxin content in Alexandrium cells. This implied that PSP toxin was possibly involved in allelopathy of A. tamarense. However, the rapid decomposition and inactivation of PSP toxin above pH 7 weakened this possibility. Further studies on the allelochemicals responsible for the allelopathy of A. tamarense need to be carried out in future.

  20. Structurally reduced monosaccharide transporters in an evolutionarily conserved red alga.

    PubMed

    Schilling, Silke; Oesterhelt, Christine

    2007-09-01

    The unicellular red alga Galdieria sulphuraria is a facultative heterotrophic member of the Cyanidiaceae, a group of evolutionary highly conserved extremophilic red algae. Uptake of various sugars and polyols is accomplished by a large number of distinct plasma membrane transporters. We have cloned three transporters [GsSPT1 (G. sulphuraria sugar and polyol transporter 1), GsSPT2 and GsSPT4], followed their transcriptional regulation and assayed their transport capacities in the heterologous yeast system. SPT1 is a conserved type of sugar/H(+) symporter with 12 predicted transmembrane-spanning domains, whereas SPT2 and SPT4 represent monosaccharide transporters, characterized by only nine hydrophobic domains. Surprisingly, all three proteins are functional plasma membrane transporters, as demonstrated by genetic complementation of a sugar uptake-deficient yeast mutant. Substrate specificities were broad and largely redundant, except for glucose, which was only taken up by SPT1. Comparison of SPT1 and truncated SPT1(Delta1-3) indicated that the N-terminus of the protein is not required for sugar transport or substrate recognition. However, its deletion affected substrate affinity as well as maximal transport velocity and released the pH dependency of sugar uptake. In line with these results, uptake by SPT2 and SPT4 was active but not pH-dependent, making a H(+) symport mechanism unlikely for the truncated proteins. We postulate SPT2 and SPT4 as functional plasma membrane transporters in G. sulphuraria. Most likely, they originated from genes encoding active monosaccharide/H(+) symporters with 12 transmembrane-spanning domains.

  1. Evidence for methane production by the marine algae Emiliania huxleyi

    NASA Astrophysics Data System (ADS)

    Lenhart, Katharina; Klintzsch, Thomas; Langer, Gerald; Nehrke, Gernot; Bunge, Michael; Schnell, Sylvia; Keppler, Frank

    2016-06-01

    Methane (CH4), an important greenhouse gas that affects radiation balance and consequently the earth's climate, still has uncertainties in its sinks and sources. The world's oceans are considered to be a source of CH4 to the atmosphere, although the biogeochemical processes involved in its formation are not fully understood. Several recent studies provided strong evidence of CH4 production in oxic marine and freshwaters, but its source is still a topic of debate. Studies of CH4 dynamics in surface waters of oceans and large lakes have concluded that pelagic CH4 supersaturation cannot be sustained either by lateral inputs from littoral or benthic inputs alone. However, regional and temporal oversaturation of surface waters occurs frequently. This comprises the observation of a CH4 oversaturating state within the surface mixed layer, sometimes also termed the "oceanic methane paradox". In this study we considered marine algae as a possible direct source of CH4. Therefore, the coccolithophore Emiliania huxleyi was grown under controlled laboratory conditions and supplemented with two 13C-labeled carbon substrates, namely bicarbonate and a position-specific 13C-labeled methionine (R-S-13CH3). The CH4 production was 0.7 µg particular organic carbon (POC) g-1 d-1, or 30 ng g-1 POC h-1. After supplementation of the cultures with the 13C-labeled substrate, the isotope label was observed in headspace CH4. Moreover, the absence of methanogenic archaea within the algal culture and the oxic conditions during CH4 formation suggest that the widespread marine algae Emiliania huxleyi might contribute to the observed spatially and temporally restricted CH4 oversaturation in ocean surface waters.

  2. Natural impacted freshwaters: in situ use of alginate immobilized algae to the assessment of algal response.

    PubMed

    Corrêa, A X R; Tamanaha, M S; Horita, C O; Radetski, M R; Corrêa, R; Radetski, C M

    2009-05-01

    The objective of this study was to investigate the feasibility of an in situ phytotoxicity test using alginate-immobilized algae for 60 days, in the assessment of water quality in an impacted small peri-urban stream. After laboratory optimization of algae immobilization/de-immobilization processes, the performance of immobilized/de-immobilized algae was compared to the performance of free algae in terms of specific algal growth and sensitivity. This was done by comparing 72 h EC50 values obtained with zinc and the pesticides clomazone and carbofuran. The results showed a similar performance, which allow us to conclude that immobilization for 60 days do not cause any significant alteration in algae physiology. In the field, immobilized algae were exposed at different times (2, 4 and 7 days) to water samples in both disturbed and undisturbed sites. Both laboratory and field experiments indicated that alginate-immobilized algae for 60 days were sufficiently sensitive for use in the in situ assessment of water quality.

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

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

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

  4. Contribution of arsenic species in unicellular algae to the cycling of arsenic in marine ecosystems.

    PubMed

    Duncan, Elliott G; Maher, William A; Foster, Simon D

    2015-01-01

    This review investigates the arsenic species produced by and found in marine unicellular algae to determine if unicellular algae contribute to the formation of arsenobetaine (AB) in higher marine organisms. A wide variety of arsenic species have been found in marine unicellular algae including inorganic species (mainly arsenate--As(V)), methylated species (mainly dimethylarsenate (DMA)), arsenoribosides (glycerol, phosphate, and sulfate) and metabolites (dimethylarsenoethanol (DMAE)). Subtle differences in arsenic species distributions exist between chlorophyte and heterokontophyte species with As(V) commonly found in water-soluble cell fractions of chlorophyte species, while DMA is more common in heterokontophyte species. Additionally, different arsenoriboside species are found in each phyla with glycerol and phosphate arsenoribosides produced by chlorophytes, whereas glycerol, phosphate, and sulfate arsenoribosides are produced by heterokontophytes, which is similar to existing data for marine macro-algae. Although arsenoribosides are the major arsenic species in many marine unicellular algal species, AB has not been detected in unicellular algae which supports the hypothesis that AB is formed in marine animals via the ingestion and further metabolism of arsenoribosides. The observation of significant DMAE concentrations in some unicellular algal cultures suggests that unicellular algae-based detritus contains arsenic species that can be further metabolized to form AB in higher marine organisms. Future research establishing how environmental variability influences the production of arsenic species by marine unicellular algae and what effect this has on arsenic cycling within marine food webs is essential to clarify the role of these organisms in marine arsenic cycling. PMID:25443092

  5. Landfill leachate--a water and nutrient resource for algae-based biofuels.

    PubMed

    Edmundson, Scott J; Wilkie, Ann C

    2013-01-01

    There is a pressing need for sustainable renewable fuels that do not negatively impact food and water resources. Algae have great potential for the production of renewable biofuels but require significant water and fertilizer resources for large-scale production. Municipal solid waste (MSW) landfill leachate (LL) was evaluated as a cultivation medium to reduce both water and elemental fertilizer demands of algae cultivation. Daily growth rate and cell yield of two isolated species of algae (Scenedesmus cf. rubescens and Chlorella cf. ellipsoidea) were cultivated in MSW LL and compared with Bold's Basal Medium (BBM). Results suggest that LL can be used as a nutrient resource and medium for the cultivation of algae biomass. S. cf. rubescens grew well in 100% LL, when pH was regulated, with a mean growth rate and cell yield 91.2% and 92.8% of those observed in BBM, respectively. S. cf. rubescens was more adaptable than C. cf. ellipsoidea to the LL tested. The LL used in this study supported a maximum volumetric productivity of 0.55 g/L/day of S. cf. rubescens biomass. The leachate had sufficient nitrogen to supply 17.8 g/L of algae biomass, but was limited by total phosphorus. Cultivation of algae on LL offsets both water and fertilizer consumption, reducing the environmental footprint and increasing the potential sustainability of algae-based biofuels.

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

    PubMed

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

    2011-09-01

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

  7. Algae in Fish Feed: Performances and Fatty Acid Metabolism in Juvenile Atlantic Salmon

    PubMed Central

    Norambuena, Fernando; Hermon, Karen; Skrzypczyk, Vanessa; Emery, James A.; Sharon, Yoni; Beard, Alastair; Turchini, Giovanni M.

    2015-01-01

    Algae are at the base of the aquatic food chain, producing the food resources that fish are adapted to consume. Previous studies have proven that the inclusion of small amounts (<10% of the diet) of algae in fish feed (aquafeed) resulted in positive effects in growth performance and feed utilisation efficiency. Marine algae have also been shown to possess functional activities, helping in the mediation of lipid metabolism, and therefore are increasingly studied in human and animal nutrition. The aim of this study was to assess the potentials of two commercially available algae derived products (dry algae meal), Verdemin (derived from Ulva ohnoi) and Rosamin (derived from diatom Entomoneis spp.) for their possible inclusion into diet of Atlantic Salmon (Salmo salar). Fish performances, feed efficiency, lipid metabolism and final product quality were assessed to investigated the potential of the two algae products (in isolation at two inclusion levels, 2.5% and 5%, or in combination), in experimental diets specifically formulated with low fish meal and fish oil content. The results indicate that inclusion of algae product Verdemin and Rosamin at level of 2.5 and 5.0% did not cause any major positive, nor negative, effect in Atlantic Salmon growth and feed efficiency. An increase in the omega-3 long-chain polyunsaturated fatty acid (n-3 LC-PUFA) content in whole body of fish fed 5% Rosamin was observed. PMID:25875839

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

    PubMed

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

    2012-01-01

    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.

  9. Feeding preferences and the nutritional value of tropical algae for the abalone Haliotis asinina.

    PubMed

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

    2012-01-01

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

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

    PubMed Central

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

    2012-01-01

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

  11. Algae in fish feed: performances and fatty acid metabolism in juvenile Atlantic Salmon.

    PubMed

    Norambuena, Fernando; Hermon, Karen; Skrzypczyk, Vanessa; Emery, James A; Sharon, Yoni; Beard, Alastair; Turchini, Giovanni M

    2015-01-01

    Algae are at the base of the aquatic food chain, producing the food resources that fish are adapted to consume. Previous studies have proven that the inclusion of small amounts (<10% of the diet) of algae in fish feed (aquafeed) resulted in positive effects in growth performance and feed utilisation efficiency. Marine algae have also been shown to possess functional activities, helping in the mediation of lipid metabolism, and therefore are increasingly studied in human and animal nutrition. The aim of this study was to assess the potentials of two commercially available algae derived products (dry algae meal), Verdemin (derived from Ulva ohnoi) and Rosamin (derived from diatom Entomoneis spp.) for their possible inclusion into diet of Atlantic Salmon (Salmo salar). Fish performances, feed efficiency, lipid metabolism and final product quality were assessed to investigated the potential of the two algae products (in isolation at two inclusion levels, 2.5% and 5%, or in combination), in experimental diets specifically formulated with low fish meal and fish oil content. The results indicate that inclusion of algae product Verdemin and Rosamin at level of 2.5 and 5.0% did not cause any major positive, nor negative, effect in Atlantic Salmon growth and feed efficiency. An increase in the omega-3 long-chain polyunsaturated fatty acid (n-3 LC-PUFA) content in whole body of fish fed 5% Rosamin was observed.

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

    PubMed

    Blaas, Harry; Kroeze, Carolien

    2014-10-15

    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.

  13. Contribution of arsenic species in unicellular algae to the cycling of arsenic in marine ecosystems.

    PubMed

    Duncan, Elliott G; Maher, William A; Foster, Simon D

    2015-01-01

    This review investigates the arsenic species produced by and found in marine unicellular algae to determine if unicellular algae contribute to the formation of arsenobetaine (AB) in higher marine organisms. A wide variety of arsenic species have been found in marine unicellular algae including inorganic species (mainly arsenate--As(V)), methylated species (mainly dimethylarsenate (DMA)), arsenoribosides (glycerol, phosphate, and sulfate) and metabolites (dimethylarsenoethanol (DMAE)). Subtle differences in arsenic species distributions exist between chlorophyte and heterokontophyte species with As(V) commonly found in water-soluble cell fractions of chlorophyte species, while DMA is more common in heterokontophyte species. Additionally, different arsenoriboside species are found in each phyla with glycerol and phosphate arsenoribosides produced by chlorophytes, whereas glycerol, phosphate, and sulfate arsenoribosides are produced by heterokontophytes, which is similar to existing data for marine macro-algae. Although arsenoribosides are the major arsenic species in many marine unicellular algal species, AB has not been detected in unicellular algae which supports the hypothesis that AB is formed in marine animals via the ingestion and further metabolism of arsenoribosides. The observation of significant DMAE concentrations in some unicellular algal cultures suggests that unicellular algae-based detritus contains arsenic species that can be further metabolized to form AB in higher marine organisms. Future research establishing how environmental variability influences the production of arsenic species by marine unicellular algae and what effect this has on arsenic cycling within marine food webs is essential to clarify the role of these organisms in marine arsenic cycling.

  14. Photosynthetic recovery following desiccation of desert green algae (Chlorophyta) and their aquatic relatives.

    PubMed

    Gray, Dennis W; Lewis, Louise A; Cardon, Zoe G

    2007-10-01

    Recent molecular data suggest that desert green algae have evolved from freshwater ancestors at least 14 times in three major classes (Chlorophyceae, Trebouxiophyceae and Charophyceae), offering a unique opportunity to study the adaptation of photosynthetic organisms to life on land in a comparative phylogenetic framework. We examined the photorecovery of phylogenetically matched desert and aquatic algae after desiccation in darkness and under illumination. Desert algae survived desiccation for at least 4 weeks when dried in darkness, and recovered high levels of photosynthetic quantum yield within 1 h of rehydration in darkness. However, when 4 weeks of desiccation was accompanied by illumination, three of six desert taxa lost their ability to recover quantum yield during rehydration in the dark. Aquatic algae, in contrast, recovered very little during dark rehydration following even just 24 h of desiccation. Re-illuminating rehydrated algae produced a nearly complete recovery of quantum yield in all desert and two of five aquatic taxa. These contrasts provide physiological evidence that desert green algae possess mechanisms for photosynthetic recovery after desiccation distinct from those in aquatic relatives, corroborating molecular evidence that they are not happenstance, short-term visitors from aquatic environments. Photosensitivity during desiccation among desert algae further suggests that they may reside in protected microsites within crusts, and species specificity of photosensitivity suggests that disturbances physically disrupting crusts could lead to shifts or losses of taxonomic diversity within these habitats.

  15. Algae in fish feed: performances and fatty acid metabolism in juvenile Atlantic Salmon.

    PubMed

    Norambuena, Fernando; Hermon, Karen; Skrzypczyk, Vanessa; Emery, James A; Sharon, Yoni; Beard, Alastair; Turchini, Giovanni M

    2015-01-01

    Algae are at the base of the aquatic food chain, producing the food resources that fish are adapted to consume. Previous studies have proven that the inclusion of small amounts (<10% of the diet) of algae in fish feed (aquafeed) resulted in positive effects in growth performance and feed utilisation efficiency. Marine algae have also been shown to possess functional activities, helping in the mediation of lipid metabolism, and therefore are increasingly studied in human and animal nutrition. The aim of this study was to assess the potentials of two commercially available algae derived products (dry algae meal), Verdemin (derived from Ulva ohnoi) and Rosamin (derived from diatom Entomoneis spp.) for their possible inclusion into diet of Atlantic Salmon (Salmo salar). Fish performances, feed efficiency, lipid metabolism and final product quality were assessed to investigated the potential of the two algae products (in isolation at two inclusion levels, 2.5% and 5%, or in combination), in experimental diets specifically formulated with low fish meal and fish oil content. The results indicate that inclusion of algae product Verdemin and Rosamin at level of 2.5 and 5.0% did not cause any major positive, nor negative, effect in Atlantic Salmon growth and feed efficiency. An increase in the omega-3 long-chain polyunsaturated fatty acid (n-3 LC-PUFA) content in whole body of fish fed 5% Rosamin was observed. PMID:25875839

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

    NASA Astrophysics Data System (ADS)

    Zhu, Baohua; Pan, Kehou; Wang, Guangce

    2008-02-01

    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.

  17. Platinum Anniversary: Virus and Lichen Alga Together More than 70 Years

    PubMed Central

    Petrzik, Karel; Vondrák, Jan; Kvíderová, Jana; Lukavský, Jaromír

    2015-01-01

    Trebouxia aggregata (Archibald) Gärtner (phylum Chlorophyta, family Trebouxiaceae), a lichen symbiotic alga, has been identified as host of the well-known herbaceous plant virus Cauliflower mosaic virus (CaMV, family Caulimoviridae). The alga had been isolated from Xanthoria parietina more than 70 years ago and has been maintained in a collection since that time. The CaMV detected in this collection entry has now been completely sequenced. The virus from T. aggregata is mechanically transmissible to a herbaceous host and induces disease symptoms there. Its genome differs by 173 nt from the closest European CaMV-D/H isolate from cauliflower. No site under positive selection was found on the CaMV genome from T. aggregata. We therefore assume that the virus’s presence in this alga was not sufficiently long to fix any specific changes in its genome. Apart from this symbiotic alga, CaMV capsid protein sequences were amplified from many other non-symbiotic algae species maintained in a collection (e.g., Oonephris obesa, Elliptochloris sp., Microthamnion kuetzingianum, Chlorella vulgaris, Pseudococcomyxa sp.). CaMV-free Chlorella vulgaris was treated with CaMV to establish virus infection. The virus was still detected there after five passages. The virus infection is morphologically symptomless on Chlorella algae and the photosynthesis activity is slightly decreased in comparison to CaMV-free alga culture. This is the first proof as to the natural presence of CaMV in algae and the first demonstration of algae being artificially infected with this virus. PMID:25789995

  18. The importance of vertical resolution in sea ice algae production models

    NASA Astrophysics Data System (ADS)

    Duarte, Pedro; Assmy, Philipp; Hop, Haakon; Spreen, Gunnar; Gerland, Sebastian; Hudson, Stephen R.

    2015-05-01

    In this study an ice-algal mathematical model is used to resolve the vertical fine structure of sea ice with ice algae, and results are compared to simulations with ice algae located only at the bottom ice layer and to those where ice algae are distributed homogeneously across part of the ice column. Ice algae are reported to contribute 4-26% of overall Arctic Ocean primary production and are an important food source for the ice-associated ecosystem. Thus, it is important to estimate the future impacts of global warming on the contribution of ice algae to Arctic primary production. Primary production models, describing the relationships between ice-algal physiology and population dynamics, with environmental forcing and trophic interactions involving bacteria and grazers, can be applied to quantify such impacts. One important aspect in these models is how to represent the vertical distribution of ice algae in sea ice. In most models, only the bottom ice layer is considered where most of the algal biomass tends to be concentrated. However, since ice algae are also present along the entire ice column, this may lead to underestimation of ice-algal production. Some empirical data and model results suggest that ice algae located in the surface and interior layers may be kept at lower concentrations, in spite of high growth rates, due to grazing by micro- and meiofauna. Results obtained in this study show the importance of resolving vertically the distribution of ice algae to avoid bias in primary production estimates, well in line with empirical studies.

  19. Energy Productivity of the High Velocity Algae Raceway Integrated Design (ARID-HV)

    SciTech Connect

    Attalah, Said; Waller, Peter M.; Khawam, George; Ryan, Randy D.; Huesemann, Michael H.

    2015-06-03

    The original Algae Raceway Integrated Design (ARID) raceway was an effective method to increase algae culture temperature in open raceways. However, the energy input was high and flow mixing was poor. Thus, the High Velocity Algae Raceway Integrated Design (ARID-HV) raceway was developed to reduce energy input requirements and improve flow mixing in a serpentine flow path. A prototype ARID-HV system was installed in Tucson, Arizona. Based on algae growth simulation and hydraulic analysis, an optimal ARID-HV raceway was designed, and the electrical energy input requirement (kWh ha-1 d-1) was calculated. An algae growth model was used to compare the productivity of ARIDHV and conventional raceways. The model uses a pond surface energy balance to calculate water temperature as a function of environmental parameters. Algae growth and biomass loss are calculated based on rate constants during day and night, respectively. A 10 year simulation of DOE strain 1412 (Chlorella sorokiniana) showed that the ARID-HV raceway had significantly higher production than a conventional raceway for all months of the year in Tucson, Arizona. It should be noted that this difference is species and climate specific and is not observed in other climates and with other algae species. The algae growth model results and electrical energy input evaluation were used to compare the energy productivity (algae production rate/energy input) of the ARID-HV and conventional raceways for Chlorella sorokiniana in Tucson, Arizona. The energy productivity of the ARID-HV raceway was significantly greater than the energy productivity of a conventional raceway for all months of the year.

  20. Snow algae of the Sierra Nevada, Spain, and High Atlas mountains of Morocco.

    PubMed

    Duval, B; Duval, E; Hoham, R W

    1999-03-01

    Snow algae (Chlorophyta) are reported from the Sierra Nevada mountains in southern Spain and the High Atlas mountains of Morocco. Populations of the snow algae Chlamydomonas sp., coloring the snow orange-red, were collected from Pico de Veleta, Spain, while snow samples from Mt. Neltner in the High Atlas mountains, contained resting spores of an orange-green colored Chloromonas sp. Other microbes observed in snow samples include bacteria, fungi, heterotrophic euglenids, diatoms, nematodes, and heterotrophic mastigotes (flagellated protists). This is the first report of snow algae from the Sierra Nevada mountains of Spain and from the Afro-alpine environment.

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

    USGS Publications Warehouse

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

    1991-01-01

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

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

    PubMed

    Sahin, B; Ozdemir, T

    2008-09-15

    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.

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

    SciTech Connect

    1996-04-01

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

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

    SciTech Connect

    Not Available

    1992-05-01

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

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

    PubMed

    Yuyama, Ikuko; Higuchi, Tomihiko

    2014-01-01

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

  6. Attraction of gravid anopheles Pseudopunctipennis females to oviposition substrates by Spirogyra majuscula (Zygnematales: Zygnmataceae) algae under laboratory conditions.

    PubMed

    Torres-Estrada, José L; Meza-Alvarez, Rosa A; Cruz-López, Leopoldo; Rodríguez, Mario H; Arredondo-Jiménez, Juan I

    2007-03-01

    The attraction of Anopheles pseudopunctipennis gravid females to oviposition substrates containing Spirogyra majuscula algae was investigated under laboratory conditions. Gravid females deposited significantly more eggs in cups containing natural algae in water from breeding sites than in cups containing artificial (nylon rope) life-like algae in water from the corresponding natural breeding site, or in cups containing natural algae in distilled water. Bioassays with Spirogyra majuscula organic extracts indicated that these extracts at concentrations of 0.1%, 0.01%, and 0.001% attracted more oviposition, but concentrations of 1%, 10%, and 100% were repellent. Gas chromatography and mass spectrometry analysis of algae organic extracts revealed a mixture of ethyl acetate and hydrocarbons compounds. These results suggest that the attraction of gravid An. pseudopunctipennis to natural breeding sites containing filamentous algae is probably mediated by organic compounds released by the algae.

  7. Use of Copper to Selectively Inhibit Brachionus calyciflorus (Predator) Growth in Chlorella kessleri (Prey) Mass Cultures for Algae Biodiesel Production

    PubMed Central

    Pradeep, Vishnupriya; Van Ginkel, Steven W.; Park, Sichoon; Igou, Thomas; Yi, Christine; Fu, Hao; Johnston, Rachel; Snell, Terry; Chen, Yongsheng

    2015-01-01

    A single Brachionus rotifer can consume thousands of algae cells per hour causing an algae pond to crash within days of infection. Thus, there is a great need to reduce rotifers in order for algal biofuel production to become reality. Copper can selectively inhibit rotifers in algae ponds, thereby protecting the algae crop. Differential toxicity tests were conducted to compare the copper sensitivity of a model rotifer—B. calyciflorus and an alga, C. kessleri. The rotifer LC50 was <0.1 ppm while the alga was not affected up to 5 ppm Cu(II). The low pH of the rotifer stomach may make it more sensitive to copper. However, when these cultures were combined, a copper concentration of 1.5 ppm was needed to inhibit the rotifer as the alga bound the copper, decreasing its bioavailability. Copper (X ppm) had no effect on downstream fatty acid methyl ester extraction. PMID:26404247

  8. Use of Copper to Selectively Inhibit Brachionus calyciflorus (Predator) Growth in Chlorella kessleri (Prey) Mass Cultures for Algae Biodiesel Production.

    PubMed

    Pradeep, Vishnupriya; Van Ginkel, Steven W; Park, Sichoon; Igou, Thomas; Yi, Christine; Fu, Hao; Johnston, Rachel; Snell, Terry; Chen, Yongsheng

    2015-08-31

    A single Brachionus rotifer can consume thousands of algae cells per hour causing an algae pond to crash within days of infection. Thus, there is a great need to reduce rotifers in order for algal biofuel production to become reality. Copper can selectively inhibit rotifers in algae ponds, thereby protecting the algae crop. Differential toxicity tests were conducted to compare the copper sensitivity of a model rotifer-B. calyciflorus and an alga, C. kessleri. The rotifer LC50 was <0.1 ppm while the alga was not affected up to 5 ppm Cu(II). The low pH of the rotifer stomach may make it more sensitive to copper. However, when these cultures were combined, a copper concentration of 1.5 ppm was needed to inhibit the rotifer as the alga bound the copper, decreasing its bioavailability. Copper (X ppm) had no effect on downstream fatty acid methyl ester extraction.

  9. A new index to assess chemicals increasing the greenhouse effect based on their toxicity to algae.

    PubMed

    Wang, Ting; Zhang, Xiaoxian; Tian, Dayong; Gao, Ya; Lin, Zhifen; Liu, Ying; Kong, Lingyun

    2015-11-01

    CO2, as the typical greenhouse gas causing the greenhouse effect, is a major global environmental problem and has attracted increasing attention from governments. Using algae to eliminate CO2, which has been proposed as an effective way to reduce the greenhouse effect in the past decades, can be disturbed by a growing number of artificial chemicals. Thus, seven types of chemicals and Selenastrum capricornutum (algae) were examined in this study, and the good consistency between the toxicity of artificial chemicals to algae and the disturbance of carbon fixation by the chemicals was revealed. This consistency showed that the disturbance of an increasing number of artificial chemicals to the carbon fixation of algae might be a "malware" worsening the global greenhouse effect. Therefore, this study proposes an original, promising index to assess the risk of deepening the greenhouse effect by artificial chemicals before they are produced and marketed. PMID:26520250

  10. 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 ...

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

    PubMed

    Ucko, M; Cohen, E; Gordin, H; Arad, S M

    1989-11-01

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

  12. Aluminum bioavailability to the green alga Chlorella pyrenoidosa in acidified synthetic soft water

    SciTech Connect

    Parent, L.; Campbell, P.G.C. )

    1994-04-01

    A unicellular green alga, Chlorella pyrenoidosa, was exposed to inorganic Al under controlled experimental conditions to determine whether the biological response elicited by the dissolved metal could be predicted from the free-metal ion concentration, [Al[sup 3+

  13. Effect of O3 and O3/H2O2 on algae harvesting using chitosan.

    PubMed

    Pranowo, R; Lee, D J; Liu, J C; Chang, J S

    2013-01-01

    We examined the effects of pre-oxidation using ozone (O3) and a combination of O3 and hydrogen peroxide (O3/H2O2) on algae suspensions and their harvesting. Inactivation of algae cells, release of intracellular organic matter (IOM), mineralization of extracellular organic matter (EOM), and changes in molecular weight distribution of EOM were found after pre-oxidation. Enhanced separation efficiency of turbidity, dissolved organic carbon (DOC), protein, and polysaccharide using chitosan and polyaluminum chloride (PACl) was found after pre-oxidation, especially when algae cells were subject to O3/H2O2. Chitosan showed higher efficiency than PACl. Judging from the remarkable increase in floc size, it was proposed that released IOM formed complexes with cationic chitosan and resulted in enhanced dual flocculation and facilitated algae separation.

  14. A new index to assess chemicals increasing the greenhouse effect based on their toxicity to algae.

    PubMed

    Wang, Ting; Zhang, Xiaoxian; Tian, Dayong; Gao, Ya; Lin, Zhifen; Liu, Ying; Kong, Lingyun

    2015-11-01

    CO2, as the typical greenhouse gas causing the greenhouse effect, is a major global environmental problem and has attracted increasing attention from governments. Using algae to eliminate CO2, which has been proposed as an effective way to reduce the greenhouse effect in the past decades, can be disturbed by a growing number of artificial chemicals. Thus, seven types of chemicals and Selenastrum capricornutum (algae) were examined in this study, and the good consistency between the toxicity of artificial chemicals to algae and the disturbance of carbon fixation by the chemicals was revealed. This consistency showed that the disturbance of an increasing number of artificial chemicals to the carbon fixation of algae might be a "malware" worsening the global greenhouse effect. Therefore, this study proposes an original, promising index to assess the risk of deepening the greenhouse effect by artificial chemicals before they are produced and marketed.

  15. A reaction-diffusion-advection model of harmful algae growth with toxin degradation

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

    This paper is devoted to the study of a reaction-diffusion-advection system modeling the dynamics of a single nutrient, harmful algae and algal toxin in a flowing water habitat with a hydraulic storage zone. We introduce the basic reproduction ratio R0 for algae and show that R0 serves as a threshold value for persistence and extinction of the algae. More precisely, we prove that the washout steady state is globally attractive if R0 < 1, while there exists a positive steady state and the algae is uniformly persistent if R0 > 1. With an additional assumption, we obtain the uniqueness and global attractivity of the positive steady state in the case where R0 > 1.

  16. 3D-PTV measurement of the phototactic movement of algae in shear flow

    NASA Astrophysics Data System (ADS)

    Maeda, Tatsuyuki; Ishikawa, Takuji; Ueno, Hironori; Numayama-Tsuruta, Keiko; Imai, Yosuke; Yamaguchi, Takami

    2012-11-01

    Recently, swimming motion of algae cells is researched actively, because algae fuel is one of the hottest topic in engineering. It is known that algae swim toward the light for photosynthesis however, the effect of a background flow on the unidirectional swimming is unclear. In this study, we used Volvox as a model alga and placed them in a simple shear flow with or without light stimulus. The shear flow was generated by moving two flat sheets in the opposite direction tangentially. A red LED light (wave length 660 nm) was used as an observation light source, and a white LED light was used to stimulate cells for the phototaxis. The trajectories of individual cells were measured by a 3D-PTV system, consists of a pair of high-speed camera with macro lenses. The results were analyzed to understand the effect of the background shear flow on the phototaxis of cells.

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

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

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

  18. Raman spectroscopy of senescing snow algae: pigmentation changes in an Antarctic cold desert extremophile

    NASA Astrophysics Data System (ADS)

    Edwards, Howell G. M.; de Oliveira, Luiz F. C.; Cockell, Charles S.; Cynan Ellis-Evans, J.; Wynn-Williams, David D.

    2004-04-01

    The FT-Raman spectra are described of green and red snow algae, Chlamydomona, involved in the colonization of exposed surfaces of the McLeod Glacier, Jane Col, Signy Island, situated at the northern edge of the Weddell Sea, Antarctica. The protective biochemicals produced by these extremophilic algae give rise to the so-called watermelon snow of Alpine regions. The red colour of the senescent algae is shown to derive from the accumulation of carotenoids and a deficiency of chlorophyll believed to arise from UV-radiation induced breakdown into phaecophytin. A comparison of the Raman spectra of young (green) and old (red) algae is effected and possible bio-markers for spectral detection on extraterrestrial icy moons and planets are identified.

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

    NASA Technical Reports Server (NTRS)

    Vincent, Robert (Inventor)

    2006-01-01

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

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

    ERIC Educational Resources Information Center

    Case, Christine L.; Warner, Michael

    2001-01-01

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