Macro algae as substrate for biogas production

DEFF Research Database (Denmark)

Møller, Henrik; Sarker, Shiplu; Gautam, Dhan Prasad

Algae as a substrate for biogas is superior to other crops since it has a much higher yield of biomass per unit area and since algae grows in the seawater there will be no competition with food production on agricultural lands. So far, the progress in treating different groups of algae as a source...... of energy is promising. In this study 5 different algae types were tested for biogas potential and two algae were subsequent used for co-digestion with manure. Green seaweed, Ulva lactuca and brown seaweed Laminaria digitata was co-digested with cattle manure at mesophilic and thermophilic condition...

Biochars derived from wasted marine macro-algae (Saccharina japonica and Sargassum fusiforme) and their potential for heavy metal removal in aqueous solution.

Science.gov (United States)

Poo, Kyung-Min; Son, Eun-Bi; Chang, Jae-Soo; Ren, Xianghao; Choi, Yun-Jung; Chae, Kyu-Jung

2018-01-15

For the purpose of reusing wasted marine macro-algae generated during cultivation, harvesting, processing and selling processes, biochars derived from Saccharina japonica (known as kelp) and Sargassum fusiforme (known as hijikia) were characterized and their removal capacities for Cu, Cd, and Zn in aqueous solution were assessed. Feedstocks, S. japonica, S. fusiforme, and also pinewood sawdust as a control, were pyrolyzed at 250, 400, 500, 600 and 700 °C. In evaluating heavy metal removal capacities, SJB (S. japonica biochar) showed the best performance, with removal efficiencies of more than 98% for the three heavy metals when pyrolyzed at over 400 °C. SFB (S. fusiforme biochar) also showed good potential as an adsorbent, with removal efficiencies for the three heavy metals of more than 86% when pyrolyzed at over 500 °C. On the contrary, the maximum removal efficiencies of PSB (pinewood sawdust biochar) were 81%, 46%, and 47% for Cu, Cd, and Zn, respectively, even at 700 °C, the highest pyrolysis temperature. This demonstrates that marine macro-algae were advantageous in terms of production energy for removing heavy metals even at relatively low pyrolysis temperatures, compared with PSB. The excellent heavy metal adsorption capacities of marine macro-algae biochars were considered due to their higher pH and more oxygen-containing functional groups, although the specific surface areas of SJB and SFB were significantly lower than that of PSB. This research confirmed that the use of marine macro-algae as a heavy metal adsorbent was suitable not only in the removal of heavy metals, but also in terms of resource recycling and energy efficiency. Copyright © 2017 Elsevier Ltd. All rights reserved.

Macro-algae biomass and cover from nearshore regions of the Nantorium War Memorial, Waikiki, Oahu, Hawaii, 1966-2005 (NODC Accession 0040082)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Department of Zoology, University of Hawaii at Manoa, incorporated surveys of macro-algae as part of the Zoology 439L "Laboratory in Ecology" during annual field...

Macro-algae Biomass and Cover from Nearshore Regions of the Natatorium War Memorial, Waikiki, Oahu, Hawaii 1966-2005 (NODC Accession 0040082)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Department of Zoology, University of Hawaii at Manoa, incorporated surveys of macro-algae as part of the Zoology 439L "Laboratory in Ecology" during annual field...

Aquatic macro algae of a region under Almirante Alvaro Alberto nuclear power plant influence. I. Spatial seasonal evaluation; Macroalgas marinhas da regiao sob influencia da Central Nuclear Almirante Alvaro Alberto (CNAAA), Saco de Piraquara de Fora, Angra dos Reis, RJ, Brasil. I. Avaliacao espaco-temporal

Energy Technology Data Exchange (ETDEWEB)

Pedrini, A.G. [Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ (Brazil)]|[Universidade Santa Ursula, Rio de Janeiro, RJ (Brazil). Centro de Ciencias Biologicas; Cassano, V.; Coelho, L.G.; Labronici, G.J. [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Inst. de Biologia

1994-12-31

Marine macro algae from the area which is under in fluence of the heated and chlorate liquid effluent to the CNAAA were observed (1981-1983) at 3 collection points: Pingo Dagua, Velho Beach, discharge point. A total of 121 taxa were found: 29 Chlorophyta, 26 Phaeophyta and 66 Rhodophyta. The spring season was the richest in taxa (78) while autumn was the poorest (85). Overall, the data suggest that the point A (Pingo Dagua) macro algae community (which is similar to the discharge point (0,80) is adequate for the control of the CNAAA effluent impact ad Piraquara de Fora. (author). 11 refs, 5 figs, 1 tab.

Non-destructive alpha-particle activation analysis of P, Cl, K and Ca in marine macro-alga samples using synthetic multielement reference material as comparative standard

International Nuclear Information System (INIS)

Iwata, Y.; Naitoh, H.; Suzuki, N.

1992-01-01

A Synthetic Reference Material (SyRM) composed with accurately known amounts of 12 elements has been prepared. The elemental composition of the SyRM is closely similar to that of marine macro-algae sample. The elemental composition of the SyRM was regulated by the starting materials used for the synthesis. The SyRM was used as a comparative standard for non-destructive alpha-particle activation analysis of marine macro-alga samples. P, Cl, K and Ca were determined simultaneously without correction for alpha range due to difference in the elemental composition between the analytical samples and the comparative standard. (author) 19 refs.; 4 tabs

Cellscope Aquatic: a Lab Quality, Portable Cellphone-Based Microscope for On-Site Collection of Algae Images

Science.gov (United States)

Steinberg, S. J.; Howard, M. D.

2016-02-01

Collecting algae samples from the field presents issues of specimen damage or degradation caused by preservation methods, handling and transport to laboratory facilities for identification. Traditionally, in-field collection of high quality microscopic images has not been possible due to the size, weight and fragility of high quality instruments and training of field staff in species identification. Scientists at the Southern California Coastal Water Research Project (SCCWRP) in collaboration with the Fletcher Lab, University of California Berkeley, Department of Bioengineering, tested and translated Fletcher's original medical CellScope for use in environmental monitoring applications. Field tests conducted by SCCWRP in 2014 led to modifications of the clinical CellScope to one better suited to in-field microscopic imaging for aquatic organisms. SCCWRP subsequently developed a custom cell-phone application to acquire microscopic imagery using the "CellScope Aquatic "in combination with other cell-phone derived field data (e.g. GPS location, date, time and other field observations). Data and imagery collected in-field may be transmitted in real-time to a web-based data system for tele-taxonomy evaluation and assessment by experts in the office. These hardware and software tools was tested in field in a variety of conditions and settings by multiple algae experts during the spring and summer of 2015 to further test and refine the CellScope Aquatic platform. The CellScope Aquatic provides an easy-to-use, affordable, lightweight, professional quality, data collection platform for environmental monitoring. Our ongoing efforts will focus on development of real-time expert systems for data analysis and image processing, to provide onsite feedback to field scientists.

Toxicity and transfer of polyvinylpyrrolidone-coated silver nanowires in an aquatic food chain consisting of algae, water fleas, and zebrafish

Energy Technology Data Exchange (ETDEWEB)

Chae, Yooeun; An, Youn-Joo, E-mail: anyjoo@konkuk.ac.kr

2016-04-15

Highlights: • Trophic transfer of silver nanowires (AgNWs) was studied in an aquatic food chain. • The transfer of AgNWs from algae to fish via water fleas was observed. • Toxicity of long AgNWs on aquatic organisms is higher than that of short ones. • AgNWs damage the gut of water fleas and may cause undernourishment. • Quantity of lipid droplets increased with increasing exposure concentration. - Abstract: Nanomaterials of various shapes and dimensions are widely used in the medical, chemical, and electronic industries. Multiple studies have reported the ecotoxicological effects of nanaoparticles when released in aquatic and terrestrial ecosystems; however, information on the toxicity of silver nanowires (AgNWs) to freshwater organisms and their transfer through the food webs is limited. In the present study, we aimed to evaluate the toxicity of 10- and 20-μm-long AgNWs to the alga Chlamydomonas reinhardtii, the water flea Daphnia magna, and the zebrafish and study their movement through this three-species food chain using a variety of qualitative and quantitative methods as well as optical techniques. We found that AgNWs directly inhibited the growth of algae and destroyed the digestive organs of water fleas. The results showed that longer AgNWs (20 μm) were more toxic than shorter ones (10 μm) to both algae and water fleas, but shorter AgNWs were accumulated more than longer ones in the body of the fish. Overall, this study suggests that AgNWs are transferred through food chains, and that they affect organisms at higher trophic levels, potentially including humans. Therefore, further studies that take into account environmental factors, food web complexity, and differences between nanomaterials are required to gain better understanding of the impact of nanomaterials on natural communities and human health.

Toxicity and transfer of polyvinylpyrrolidone-coated silver nanowires in an aquatic food chain consisting of algae, water fleas, and zebrafish

International Nuclear Information System (INIS)

Chae, Yooeun; An, Youn-Joo

2016-01-01

Highlights: • Trophic transfer of silver nanowires (AgNWs) was studied in an aquatic food chain. • The transfer of AgNWs from algae to fish via water fleas was observed. • Toxicity of long AgNWs on aquatic organisms is higher than that of short ones. • AgNWs damage the gut of water fleas and may cause undernourishment. • Quantity of lipid droplets increased with increasing exposure concentration. - Abstract: Nanomaterials of various shapes and dimensions are widely used in the medical, chemical, and electronic industries. Multiple studies have reported the ecotoxicological effects of nanaoparticles when released in aquatic and terrestrial ecosystems; however, information on the toxicity of silver nanowires (AgNWs) to freshwater organisms and their transfer through the food webs is limited. In the present study, we aimed to evaluate the toxicity of 10- and 20-μm-long AgNWs to the alga Chlamydomonas reinhardtii, the water flea Daphnia magna, and the zebrafish and study their movement through this three-species food chain using a variety of qualitative and quantitative methods as well as optical techniques. We found that AgNWs directly inhibited the growth of algae and destroyed the digestive organs of water fleas. The results showed that longer AgNWs (20 μm) were more toxic than shorter ones (10 μm) to both algae and water fleas, but shorter AgNWs were accumulated more than longer ones in the body of the fish. Overall, this study suggests that AgNWs are transferred through food chains, and that they affect organisms at higher trophic levels, potentially including humans. Therefore, further studies that take into account environmental factors, food web complexity, and differences between nanomaterials are required to gain better understanding of the impact of nanomaterials on natural communities and human health.

A new method for tracing flows of nitrogen and carbon through bacteria and algae in aquatic microbial communities: Analysis of 15N- and 13C-incorporation into D-alanine and other hydrolysable amino acids

NARCIS (Netherlands)

Veuger, B.

2006-01-01

Nitrogen flows through bacteria and algae in aquatic microbial communities are an important part of the nitrogen cycle, which plays a central role in aquatic ecosystems. However, work on uptake and retention of nitrogen in bacteria versus algae in natural microbial communities has long been hampered

Screening of proteins based on macro-algae from West Java coast in Indonesian marine as a potential anti-aging agent

Science.gov (United States)

Putri, Arlina Prima; Dewi, Rizna Triana; Handayani, Aniek Sri; Harjanto, Sri; Chalid, Mochamad

2018-02-01

Algae has been known as one of the potential marine bio-resources that have been used in many fields such as bio-energy, food, pharmaceutical and medical applications. Study of macro-algae or seaweed for medicine application, in particular, highlights to empower their ingredients as a promising antioxidant like anti-aging agent due to their diversity in biological activity. The tropical climate of Indonesia with the highest marine biodiversity puts this country an auspicious source of numerous alga species as a novel antioxidant source. A Sample of 29 species of macroalgae has been collected from Coast of Pari Island as a part of Seribu Islands, Indonesia. Screening and extracting of aqueous tropical marine alga protein as a potential source for an antioxidant agent has been done by using 2,2-diphenyl-1-picrylhydrazyl scavenging method, and protein contents have been determined by Lowry method. Sample number 26 of the phylum Rhodophyta have 9.00±0.03 % protein content, which is potential for nutritional food in form of nutraceutical. That sample demonstrated the maximum DPPH scavenging activity 79.27±1.81 %. Moreover, crude extract from another species from phylum Rhodophyta had the very lower IC50 (3.4333±0.29 mg/ml) followed by Chlorophyta species (7.1069±1.78 mg/ml). In general, this study found that algae from phylum Rhodophyta possess a high content of protein, high activity towards free radical. Nevertheless, algae acquire the lowest IC50 value not only dominated by Rhodophyta but also from phylum Chlorophyta. The conclusion of this study leads to empowering high antioxidant activity algae as an anti-aging agent, which can be used in pharmaceutical applications. Therefore, the next study should be concerned on the properties of the algae which has been known to be suitable for pharmaceutical fields.

Hydrothermal liquefaction of Gracilaria gracilis and Cladophora glomerata macro-algae for biocrude production.

Science.gov (United States)

Parsa, Mehran; Jalilzadeh, Hamoon; Pazoki, Maryam; Ghasemzadeh, Reza; Abduli, MohammadAli

2018-02-01

The potential of Gracilaria gracilis (G. gracilis) and Cladophora glomerata (C. glomerata) macro-algae species harvested from Caspian Sea for biocrude oil production under Hydrothermal Liquefaction (HTL) reaction at 350 °C and 15 min has been investigated. Furthermore, the effect of using recycled aqueous phase as the HTL reaction solvent was studied. The biocrude yield for G. gracilis and C. glomerata was 15.7 and 16.9 wt%, respectively with higher heating value (HHV) of 36.01 and 33.06 MJ/kg. The sources of each existing component in bio-oil were identified by GC-MS based on their suggested reaction pathways. Moreover, after two series of aqueous solution recycling, experiments showed that the bio-oil yield significantly increased compared with the initial condition. This increasing directly relates with recovery of carbon content from the aqueous solution residue. Copyright © 2017. Published by Elsevier Ltd.

Forms and lability of phosphorus in algae and aquatic macrophytes characterized by solution 31P NMR coupled with enzymatic hydrolysis

Science.gov (United States)

Increased information on forms and lability of phosphorus (P) in aquatic macrophytes and algae is crucial for better understanding of P biogeochemical cycling in eutrophic lakes. In this work, solution 31P nuclear magnetic resonance (NMR) spectroscopy coupled with enzymatic hydrolysis (EH) was used ...

Macro-economics of algae products : Output WP2A7.02

NARCIS (Netherlands)

Voort, van der M.P.J.; Vulsteke, E.; Visser, de C.L.M.

2015-01-01

This report is part of the EnAlgae Workpackage 2, Action 7, directed at the economics of algae production. The goal of this report is to highlight potential markets for algae. Per type of algae market the market size, product alternatives, constraints and prices are highlighted. Based on these

Bio sorption process for uranium (VI) by using algae-yeast-silica gel composite adsorbent

International Nuclear Information System (INIS)

Turkozu, D. A.; Aytas, S.

2006-01-01

Many yeast, algae, bacteria and various aquatic flora are known to be capable of concentrating metal species from dilute aqueous solution. Many researcher have found that non-living biomaterials can be used to accumulate metal ions from environment. In recent studies, mainly two process are used in biosorption experiments. These are the use of free cells and the use of immobilized cells on a solid support. A variety of inert supports have been used to immobilize biomaterials either by adsorption or physical entrapment. This uptake is often considerable and frequently selective, and occurs via a variety of mechanisms including active transport, ion exchange or complexation, and adsorption or inorganic precipitation. Biosorbent may be used as an ion exchange material. Adsorption occurs through interaction of the metal ions with functional groups that are found in the cell wall biopolymers of either living or dead organisms. In this study, the algae-yeast-silica gel composite adsorbent was tested for its ability to recover U(VI) from diluted aqueous solutions. Macro marine algae (Jania rubens.), yeast (Saccharomyces cerevisiae) and silica gel were used to prepare composite adsorbent. The ability of the composite biosorbent to adsorb uranium (VI) from aqueous solution has been studied at different optimized conditions of pH, concentration of U(VI), temperature, contact time and matrix ion effect was also investigated. The adsorption patterns of uranium on the composite biosorbent were investigated by the Langmuir, Freundlich and Dubinin-Radushkhevic isotherms. The thermodynamic parameters such as variation of enthalpy ΔH, variation of entropy ΔS and variation of Gibbs free energy ΔG were calculated. The results suggested that the macro algae-yeast-silica gel composite sorbent is suitable as a new biosorbent material for removal of uranium ions from aqueous solutions

Desiccation induces accumulations of antheraxanthin and zeaxanthin in intertidal macro-alga Ulva pertusa (Chlorophyta.

Directory of Open Access Journals (Sweden)

Xiujun Xie

Full Text Available For plants and algae, exposure to high light levels is deleterious to their photosynthetic machineries. It also can accelerate water evaporation and thus potentially lead to drought stress. Most photosynthetic organisms protect themselves against high light caused photodamages by xanthophyll cycle-dependent thermal energy dissipation. It is generally accepted that high light activates xanthophyll cycle. However, the relationship between xanthophyll cycle and drought stress remains ambiguous. Herein, Ulva pertusa (Chlorophyta, a representative perennial intertidal macro-algae species with high drought-tolerant capabilities and simple structures, was used to investigate the operation of xanthophyll cycle during desiccation in air. The results indicate that desiccation under dim light induced accumulation of antheraxanthin (Ax and zeaxanthin (Zx at the expense of violaxanthin (Vx. This accumulation could be arrested by dithiothreitol completely and by uncoupler (carbonyl cyanide p-trifluoromethoxyphenylhydrazone partially, implying the participation of Vx de-epoxidase in conversion of Vx to Ax and Zx. Treatment with inhibitors of electron transport along thylakoid membrane, e.g. DCMU, PG and DBMIB, did not significantly arrest desiccation-induced accumulation of Ax and Zx. We propose that for U. pertusa, besides excess light, desiccation itself could also induce accumulation of Ax and Zx. This accumulation could proceed without electron transport along thylakoid membrane, and is possibly resulting from the reduction of thylakoid lumen volume during desiccation. Considering the pleiotropic effects of Ax and Zx, accumulated Ax and Zx may function in protecting thylakoid membrane and enhancing thermal quenching during emersion in air.

Physical data and biological data for algae, aquatic invertebrates, and fish from selected reaches on the Carson and Truckee rivers, Nevada and California, 1993-97

Science.gov (United States)

Lawrence, S.J.; Seiler, R.L.

2002-01-01

This report, a product of the National Water- Quality Assessment Program, is a compilation of physical data and biological data for algae, aquatic invertebrates, and fish collected in the Carson and Truckee River Basins, Nevada and California. Most of the data were collected between 1993 and 1996 at selected reaches on the Carson and Truckee Rivers. Algae and aquatic invertebrate samples were collected from cobble riffles, submerged woody-snag habitats, and from depositional areas such as pools. Between 1993 and 1996, fish and crayfish were collected from all wadeable habitats at each of seven basic-fixed sites using either electroshocking methods or seining. Additional fish and crayfish were collected at one site on the Truckee River in 1997. Fish were identified to species, measured for total and standard length, checked for anomalies, and weighed at the collection site. Fish were returned to the stream after measurements were taken. Measurements of water depth, stream velocity, determinations of substrate type and substrate embeddedness were made at each sampling site. Algae and aquatic invertebrate samples were sent to the U.S. Geological Survey National Water-Quality Laboratory for identification and enumeration. A total of 103 semi-quantitative and 55 qualitative algae samples were collected at 20 river reaches on the Carson and Truckee Rivers between 1993 and 1996. These samples represent algae in cobble riffles, on submerged woody snags, and on sediment surfaces in depositional areas. In those 158 samples, 514 algal species, varieties, or forms were identified. Of the 8 algal phyla represented, the diatoms (Phylum Bacillariophyta) were the most abundant with 351 species, varieties, or forms. The green algae (Phylum Chlorophyta) were next in abundance with 108 species, varieties, or forms followed by the blue-green algae (Phylum Cyanophyta) with 41 species, varieties, or forms. A total of 49 semi-quantitative aquatic invertebrate samples were collected at 27

Algae of economic importance that accumulate cadmium and lead: a review

Directory of Open Access Journals (Sweden)

Priscila O. Souza

2012-08-01

Full Text Available Currently, algae and algae products are extensively applied in the pharmaceutical, cosmetic and food industries. Algae are the main organisms that take up and store heavy metals. Therefore, the use of compounds derived from algae by the pharmaceutical industry should be closely monitored for possible contamination. The pollution generated by heavy metals released by industrial and domestic sources causes serious changes in the aquatic ecosystem, resulting in a loss of biological diversity and a magnification and bioaccumulation of toxic agents in the food chain. Since algae are at the bottom of the aquatic food chain, they are the most important vector for transfer of pollution to upper levels of the trophic chain in aquatic environments. Moreover, microalgae are also used for the bioremediation of wastewater, a process that does not produce secondary pollution, that enables efficient recycling of nutrients and that generates biomass useful for the production of bioactive compounds and biofuel.

Algae of economic importance that accumulate cadmium and lead: a review

Directory of Open Access Journals (Sweden)

Priscila O. Souza

2012-06-01

Full Text Available Currently, algae and algae products are extensively applied in the pharmaceutical, cosmetic and food industries. Algae are the main organisms that take up and store heavy metals. Therefore, the use of compounds derived from algae by the pharmaceutical industry should be closely monitored for possible contamination. The pollution generated by heavy metals released by industrial and domestic sources causes serious changes in the aquatic ecosystem, resulting in a loss of biological diversity and a magnification and bioaccumulation of toxic agents in the food chain. Since algae are at the bottom of the aquatic food chain, they are the most important vector for transfer of pollution to upper levels of the trophic chain in aquatic environments. Moreover, microalgae are also used for the bioremediation of wastewater, a process that does not produce secondary pollution, that enables efficient recycling of nutrients and that generates biomass useful for the production of bioactive compounds and biofuel.

Effect of natural phosphate to remove silver interference in the detection of mercury(II in aquatic algae and seawater samples

Directory of Open Access Journals (Sweden)

S. Lahrich

2016-03-01

Full Text Available A silver particles impregnated onto natural phosphate (Ag/NP was synthesized using reaction in solid state. The obtained powder was characterized by X-ray diffraction (XRD analysis and scanning electron microscopy (SEM. The (Ag/NP was used as modifier of carbon paste electrode (CPE to determine mercury by square wave voltammetry. The calibration graph obtained is linear from 1.0 × 10−8 mol·L−1 to 1.0 × 10−5 mol·L−1 at preconcentration time of 5 min, percentage loading of 7%, with correlation coefficient of 0.993. The limits of detection (DL,3σ and quantification (QL,10σ were 5.8 × 10−9 mol·L−1 and 19.56 × 10−9 mol·L−1 respectively. The repeatability of the method expressed as relative standard deviation (R.S.D. is 2.1% (n = 8. The proposed method was successfully applied to determine mercury(II in aquatic algae and seawater samples. Keywords: Natural phosphate, Square wave voltammetry, Silver, Mercury, Aquatic algae, Seawater

Phytoremediation of organochlorine and pyrethroid pesticides by aquatic macrophytes and algae in freshwater systems.

Science.gov (United States)

Riaz, Ghazala; Tabinda, Amtul Bari; Iqbal, Shakir; Yasar, Abdullah; Abbas, Mateen; Khan, Abdul Muqeet; Mahfooz, Yusra; Baqar, Mujtaba

2017-10-03

Extensive use of Pesticides in agriculture and its surface runoff in river water is a major environmental concern. The present study evaluated the phytoremediation potential of Eichornia crassipes, Pistia strateotes and algae (Chaetomorpha sutoria, Sirogonium sticticum and Zygnema sp.) for organochlorine and pyrethroid pesticides. Water and plant samples were extracted by liquid phase and solid phase extraction respectively and analyzed by high-performance liquid chromatography. Eleven treatments (T1-T11) with and without plants were used for phytoremediation of organochlorine and pyrethroid pesticides. During the experiment, P. strateotes, E. crassipes and algae (C. sutoria, S. sticticum and Zygnema sp.) showed the highest removal efficiency with 62 (71% root, 29% shoot), 60 (67% root, 33% shoot), and 58% respectively for organochlorine and 76 (76% root, 24% shoot), 68 (69% root, 31% shoot), and 70% respectively for pyrethroids for the respective aquatic plants. Dissipation rate constant of treatments with plants (T2, T3, T5, T6, T8, and T9) was significantly higher (p < 0.05) as compared to that of treatments without plants (T10 and T11, control) for both organochlorine and pyrethroid. The bioconcentration factor of pyrethroid treatments (T3, T6, and T9) was significantly higher (p < 0.05) as compared to that of organochlorine treatments (T2, T5 and T8). The removal efficiency of E. crassipes, P. strateotes and algae (C. sutoria, S. sticticum and Zygnema sp.) for pyrethroids was significantly higher (p < 0.01) as compared to that of organochlorine.

Forms and Lability of Phosphorus in Algae and Aquatic Macrophytes Characterized by Solution 31P NMR Coupled with Enzymatic Hydrolysis

Science.gov (United States)

Feng, Weiying; Zhu, Yuanrong; Wu, Fengchang; He, Zhongqi; Zhang, Chen; Giesy, John P.

2016-11-01

Solution Phosphorus-31 nuclear magnetic resonance (31P NMR) spectroscopy coupled with enzymatic hydrolysis (EH) with commercially available phosphatases was used to characterize phosphorus (P) compounds in extracts of the dominant aquatic macrophytes and algae in a eutrophic lake. Total extractable organic P (Po) concentrations ranged from 504 to 1643 mg kg-1 and 2318 to 8395 mg kg-1 for aquatic macrophytes and algae, respectively. Using 31P NMR spectroscopy, 11 Po species were detected in the mono- and diester region. Additionally, orthophosphate, pyrophosphate and phosphonates were also detected. Using EH, phytate-like P was identified as the prevalent class of enzyme-labile Po, followed by labile monoester- and diester-P. Comparison of the NMR and EH data indicated that the distribution pattern of major P forms in the samples determined by the two methods was similar (r = 0.712, p < 0.05). Additional 31P NMR spectroscopic analysis of extracts following EH showed significant decreases in the monoester and pyrophosphate regions, with a corresponding increase in the orthophosphate signal, as compared to unhydrolyzed extracts. Based on these quantity and hydrolysis data, we proposed that recycling of Po in vegetative biomass residues is an important mechanism for long-term self-regulation of available P for algal blooming in eutrophic lakes.

A mathematical model for 137Cs uptake and release by filamentous algae

International Nuclear Information System (INIS)

Svadlenkova, M.; Dvorak, Z.; Slavik, O.; Institute of Hygiene and Epidemiology, Prague; Jaslovske Bohunice

1989-01-01

A mathematical model of the dynamics of radiocaesium transport in the aquatic phase-algae system is suggested in this work. Allowance is made for algae growth and for both reversible and irreversible absorption of this radionuclide by the algae. The algae biomass is divided hypothetically into two compartments with different exchange kinetics. The parameters of the model are time dependent. The model is quantified using experimental data for the concentrations of 137 Cs in Cladophora glomerata filamentous algae and in water, obtained in situ in the environment of a nuclear power station. The model fits the data resonably well and can be applied, for example, in bioindication of radioactivity in aquatic recipients in the environment of nuclear power stations. (author)

Composting of waste algae: a review.

Science.gov (United States)

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. Copyright © 2014 Elsevier Ltd. All rights reserved.

Is the tier-1 effect assessment for herbicides protective for aquatic algae and vascular plant communities?

Science.gov (United States)

van Wijngaarden, René P A; Arts, Gertie H P

2018-01-01

In the aquatic tier-1 effect assessment for plant protection products with an herbicidal mode of action in Europe, it is usually algae and/or vascular plants that determine the environmental risks. This tier includes tests with at least 2 algae and 1 macrophyte (Lemna). Although such tests are considered to be of a chronic nature (based on the duration of the test in relation to the life cycle of the organism), the measurement endpoints derived from the laboratory tests with plants (including algae) and used in the first-tier effect assessment for herbicides are acute effect concentrations affecting 50% of the test organisms (EC50 values) and not no-observed-effect concentrations (NOECs) or effect concentrations affecting 10% of the test organisms (EC10) values. Other European legislative frameworks (e.g., the Water Framework Directive) use EC10 values. The present study contributes to a validation of the tiered herbicide risk assessment approach by comparing the standard first-tier effect assessment with results of microcosm and mesocosm studies. We evaluated EC50 and EC10 values for standard test algae and macrophytes based on either the growth rate endpoint (E r C50) or the lowest available endpoint for growth rate or biomass/yield (E r /E y C50). These values were compared with the regulatory acceptable concentrations for the threshold option as derived from microcosm and mesocosm studies. For these studies, protection is maintained if growth rate is taken as the regulatory endpoint instead of the lowest value of either growth rate or biomass/yield in conjunction with the standard assessment factor of 10. Based on a limited data set of 14 herbicides, we did not identify a need to change the current practice. Environ Toxicol Chem 2018;37:175-183. © 2017 SETAC. © 2017 SETAC.

Growth and survival of Escherichia coli and enterococci populations in the macro-alga Cladophora (Chlorophyta).

Science.gov (United States)

Byappanahalli, Muruleedhara N; Shively, Dawn A; Nevers, Meredith B; Sadowsky, Michael J; Whitman, Richard L

2003-11-01

The macro-alga Cladophora glomerata is found in streams and lakes worldwide. High concentrations of Escherichia coli and enterococci have been reported in Cladophora along the Lake Michigan shore. The objective of this study was to determine if Cladophora supported growth of these indicator bacteria. Algal leachate readily supported in vitro multiplication of E. coli and enterococci, suggesting that leachates contain necessary growth-promoting substances. Growth was directly related to the concentration of algal leachate. E. coli survived for over 6 months in dried Cladophora stored at 4 degrees C; residual E. coli grew after mat rehydration, reaching a carrying capacity of 8 log CFU g(-1) in 48 h. Results of this study also show that the E. coli strains associated with Cladophora are highly related; in most instances they are genetically different from each other, suggesting that the relationship between E. coli and Cladophora may be casual. These findings indicate that Cladophora provides a suitable environment for indicator bacteria to persist for extended periods and to grow under natural conditions.

Direct and indirect effects of a potential aquatic contaminant on grazer-algae interactions.

Science.gov (United States)

Evans-White, Michelle A; Lamberti, Gary A

2009-02-01

Contaminants have direct, harmful effects across multiple ecological scales, including the individual, the community, and the ecosystem levels. Less, however, is known about how indirect effects of contaminants on consumer physiology or behavior might alter community interactions or ecosystem processes. We examined whether a potential aquatic contaminant, an ionic liquid, can indirectly alter benthic algal biomass and primary production through direct effects on herbivorous snails. Ionic liquids are nonvolatile organic salts being considered as an environmentally friendly potential replacement for volatile organic compounds in industry. In two greenhouse experiments, we factorially crossed four concentrations of 1-N-butyl-3-methylimidazolium bromide (bmimBr; experiment 1: 0 or 10 mg/L; experiment 2: 0, 1, or 100 mg/L) with the presence or absence of the snail Physa acuta in aquatic mesocosms. Experimental results were weighted by their respective control (no bmimBr or P. acuta) and combined for statistical analysis. When both bmimBr and snails were present, chlorophyll a abundance and algal biovolume were higher than would be expected if both factors acted additively. In addition, snail growth rates, relative to those of controls, declined by 41 to 101% at 10 and 100 mg/L of bmimBr. Taken together, these two results suggest that snails were less efficient grazers in the presence of bmimBr, resulting in release of algae from the grazer control. Snails stimulated periphyton primary production in the absence, but not in the presence, of bmimBr, suggesting that bmimBr also can indirectly alter ecosystem function. These findings suggest that sublethal contaminant levels can negatively impact communities and ecosystem processes via complex interactions, and they provide baseline information regarding the potential effects of an emergent industrial chemical on aquatic systems.

System visualization of integrated biofuels and high value chemicals developed within the MacroAlgaeBiorefinery (MAB3) project

DEFF Research Database (Denmark)

Seghetta, Michele; Hasler, Berit; Bastianoni, Simone

MacroAlgaeBiorefinery (MAB3) may functions as production platform and raw material supplier for future sustainable production chains of biofuels and high value chemicals. Biofuels are interesting energy source but challenges in terms of the composition of the biomass and resulting energy...... efficiencies has to be compensated for to make the biofuel prices competitive in replacing fossil fuel. Since it is difficult to increase the yield of the single biorefinery, the overall system productivity can be improved integrating different sub-systems. In this study, macroalgae cultivation in Denmark...... is integrated with a biogas biorefinery, a bioethanol biorefinery and a fish feed industry. The modeled system is able to adapt itself to different amount and quality of feedstock and to maximize valuable outputs (e.g. bio-fuels and chemical). Macroalgae are harvested and utilized as feedstock in bioethanol...

Improved fatty acid detection in micro-algae and aquatic meiofauna species using a direct thermal desorption interface combined with comprehensive gas chromatography-time-of-flight mass spectrometry

NARCIS (Netherlands)

Akoto, L.; Stellaard, F.; Irth, H.; Vreuls, R.J.J.; Pel, R.

2008-01-01

Comprehensive two-dimensional gas chromatography (GC × GC) with time-of-flight mass spectrometry detection is used to profile the fatty acid composition of whole/intact aquatic microorganisms such as the common fresh water green algae Scenedesmus acutus and the filamentous cyanobacterium Limnothrix

Improved fatty acid detection in micro-algae and aquatic meiofauna species using a direct thermal desorption interface combined with comprehensive gas chromatography–time-of-flight mass spectrometry

NARCIS (Netherlands)

Akoto, L.; Stellaard, F.; Irth, H.; Vreuls, R.J.J.; Pel, R.

2008-01-01

Comprehensive two-dimensional gas chromatography (GC × GC) with time-of-flight mass spectrometry detection is used to profile the fatty acid composition of whole/intact aquatic microorganisms such as the common fresh water green algae Scenedesmus acutus and the filamentous cyanobacterium Limnothrix

Improved fatty acid detection in micro-algae and aquatic meiofauna species using a direct thermal desorption interface combined with comprehensive gas chromatography-time-of-flight mass spectrometry

NARCIS (Netherlands)

Akoto, Lawrence; Stellaard, Frans; Irth, Hubertus; Vreuls, Rene J. J.; Pel, Roel

2008-01-01

Comprehensive two-dimensional gas chromatography (GC x GC) with time-of-flight mass spectrometry detection is used to profile the fatty acid composition of whole/intact aquatic microorganisms such as the common fresh water green algae Scenedesmus acutus and the filamentous cyanobacterium Limnothrix

Methane production from marine, green macro-algae

Energy Technology Data Exchange (ETDEWEB)

Hansson, G.

1983-01-01

Fermentation studies have been carried out to produce methane from green algae native to Scandinavian water and suitable for large scale cultivation. Long term semi-continuous fermentations during mesophilic and thermophilic conditions were performed as well as batch fermentations in flasks and syringes. A mixed inoculum was prepared from sediments, rotting seaweed, sewage sludge and rumen contents. Methane production from the seaweed substrate, consisting of ground green algae without any nutrient additions, started immediately in this culture, mesophilicly as well as thermophilicly. Fermentations were carried out with retention times from 27 to 11 days and loading rates from 1.1 to 2.6 g volatile solids (VS added) per litre per day. In the mesophilic fermentation, gas yields were 250-350 ml CH/sub 4//g VS added and the VS-reduction was around 50-55% at all tested retention times and loading rates. The level of volatile fatty acids was very low in this system. In the thermophilic digestor, gas yields were somewhat lower although the VS-reduction was around 50% also in this systems. The VFA-levels were higher and the culture more sensitive to disturbances. Thus no advantages were found with the thermophilic fermentation. In mesophilic batch fermentations the gas production was rather rapid and almost completed after 12-15 days, in agreement with the continuous fermentations. The gas yields in batch experiments were high, 350-480 ml CH/sub 4//g VS added. (Refs. 20).

Efficiency of using green algae as biological controllers against toxic ...

African Journals Online (AJOL)

Efficiency of using green algae as biological controllers against toxic algal taxa in cultured ... of two green algal species as biological control of the growth of toxic blue-green algae. ... African Journal of Aquatic Science 2014, 39(4): 443–450 ...

Valorising side streams in circular animal feed additives

NARCIS (Netherlands)

Weide, van der R.Y.; Elissen, H.J.H.; Dijk, van W.; Huurman, Sander; Krimpen, van M.M.

2016-01-01

Because of a growing world population there is an increasing need for protein production, in addition to traditional agriculture and fisheries. Several new crops such as microalgae, macro algae, aquatic higher plants, aquatic and terrestrial invertebrates (insects and worms) have received growing

Calcite encrustation in macro-algae Chara and its implication to the formation of carbonate-bound cadmium

International Nuclear Information System (INIS)

Siong, Kian; Asaeda, Takashi

2009-01-01

We studied the relationship between macro-algae Chara (Stoneworts) calcite (CaCO 3 ) encrustation and the speciation of cadmium (Cd) accumulated by the plant. Results showed that 17% of the total Cd (0.3 mg kg -1 ) accumulated by Chara fibrosa exposed to 1 μg Cd L -1 was carbonate-bound. The percentage of carbonate-bound Cd in the plant exposed to 10 μg Cd L -1 increased from 48% in young thalli (total Ca -1 , total Cd: 125 mg kg -1 ) to 63% in calcified mature thalli (total Ca: 190 mg g -1 ; total Cd: 134 mg kg -1 ). Based on mineral saturation calculation and reliability analysis of the sequential fractionation procedure, precipitation of otavite (CdCO 3 ) and co-precipitation of Cd with calcite, occurring in the alkaline regions of Chara cell wall, are probably the mechanisms of carbonate-bound Cd formation. Thick marl sediment frequently found beneath charophyte meadows suggests a long-term storage of Ca as well as the precipitated or co-precipitated Cd in the sediment after the plant senescence and decomposition.

Cultivation Strategy for Freshwater Macro- and Micro-Algae as Biomass Stock for Lipid Production

OpenAIRE

Verawaty, Marieska; Melwita, Elda; Apsari, Putri; Mayumi, Mayumi

2017-01-01

In this research, an algae cultivation strategy was studied. Integrating algae cultivation with wastewater treatment is currently seen as one of the most economical ways of producing algae biomass. A combination of an anaerobic baffled reactor (ABR) and a constructed wetland (CW) was applied for treating domestic wastewater with an additional collection tank for improving effluent quality. The effluent produced from the three stages was used as algae cultivation media and suplemented with 10%...

Characterization of phosphorus forms in lake macrophytes and algae by solution (31)P nuclear magnetic resonance spectroscopy.

Science.gov (United States)

Feng, Weiying; Zhu, Yuanrong; Wu, Fengchang; Meng, Wei; Giesy, John P; He, Zhongqi; Song, Lirong; Fan, Mingle

2016-04-01

Debris from aquatic macrophytes and algae are important recycling sources of phosphorus (P), which can result in continuing blooms of algae by recycling bioavailable P in the eutrophic lakes. However, knowledge of forms of P in aquatic macrophytes and algae and their contribution to internal loads of P in lakes is limited. Without such knowledge, it is difficult to develop appropriate strategies to remediate and or restore aquatic ecosystems that have become eutrophic. Therefore, in this work, P was extracted from six types of aquatic macrophytes and algae collected from Tai Lake of China and characterized by use of solution (31)P-nuclear magnetic resonance (NMR) spectroscopy. When extracted by 0.5 M NaOH-25 mM EDTA, extraction recovery of total P(TP) and organic P(Po) exceeded 90 %. Concentrations of Po in algae and aquatic macrophytes were 5552 mg kg(-1) and 1005 mg kg(-1) and accounted for 56.0 and 47.2 % of TP, respectively. When Po, including condensed P, was characterized by solution (31)P-NMR Po in algae included orthophosphate monoesters (79.8 %), pyrophosphate (18.2 %), and orthophosphate diester (2.0 %), and Po in aquatic macrophytes included orthophosphate monoesters (90.3 %), pyrophosphate (4.2 %), and orthophosphate diester (5.5 %). Additionally, orthophosphate monoesters in algal debris mainly included β-glycerophosphate (44.1 %), α-glycerophosphate (13.5 %), and glucose 6-phosphate (13.5 %). Orthophosphate monoesters in aquatic macrophytes mainly included β-glycerophosphate (27.9 %), α-glycerophosphate (24.6 %), and adenosine 5' monophosphate (8.2 %). Results derived from this study will be useful in better understanding nutrient cycling, relevant eutrophication processes, and pollution control for freshwater lakes.

Algae Bioreactor Using Submerged Enclosures with Semi-Permeable Membranes

Science.gov (United States)

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.

Comparative sensitivity of five species of macrophytes and six species of algae to atrazine, metribuzin, alachlor, and metolachlor

Science.gov (United States)

Fairchild, James F.; Ruessler, Shane; Carlson, A. Ron

1998-01-01

This study determined the relative sensitivity of five species of aquatic macrophytes and six species of algae to four commonly used herbicides (atrazine, metribuzin, alachlor, and metolachlor). Toxicity tests consisted of 96-h (duckweed and algae) or 14-d (submerged macrophytes) static exposures. The triazine herbicides (atrazine and metribuzin) were significantly more toxic to aquatic plants than were the acetanilide herbicides (alachlor and metolachlor). Toxicity studies ranked metribuzin > atrazine > alachlor > metolachlor in decreasing order of overall toxicity to aquatic plants. Relative sensitivities of macrophytes to these herbicides decreased in the order of Ceratophyllum > Najas > Elodea > Lemna > Myriophyllum. Relative sensitivities of algae to herbicides decreased in the order of Selenastrum > Chlorella > Chlamydomonas > Microcystis > Scenedesmus > Anabaena. Algae and macrophytes were of similar overall sensitivities to herbicides. Data indicated that Selenastrum, a commonly tested green alga, was generally more sensitive compared to other plant species. Lemna minor, a commonly tested floating vascular plant, was of intermediate sensitivity, and was fivefold less sensitive than Ceratophyllum, which was the most sensitive species tested. The results indicated that no species was consistently most sensitive, and that a suite of aquatic plant test species may be needed to perform accurate risk assessments of herbicides.

Rainfall changes affect the algae dominance in tank bromeliad ecosystems

Science.gov (United States)

Pires, Aliny Patricia Flauzino; Leal, Juliana da Silva; Peeters, Edwin T. H. M.

2017-01-01

Climate change and biodiversity loss have been reported as major disturbances in the biosphere which can trigger changes in the structure and functioning of natural ecosystems. Nonetheless, empirical studies demonstrating how both factors interact to affect shifts in aquatic ecosystems are still unexplored. Here, we experimentally test how changes in rainfall distribution and litter diversity affect the occurrence of the algae-dominated condition in tank bromeliad ecosystems. Tank bromeliads are miniature aquatic ecosystems shaped by the rainwater and allochthonous detritus accumulated in the bases of their leaves. Here, we demonstrated that changes in the rainfall distribution were able to reduce the chlorophyll-a concentration in the water of bromeliad tanks affecting significantly the occurrence of algae-dominated conditions. On the other hand, litter diversity did not affect the algae dominance irrespective to the rainfall scenario. We suggest that rainfall changes may compromise important self-reinforcing mechanisms responsible for maintaining high levels of algae on tank bromeliads ecosystems. We summarized these results into a theoretical model which suggests that tank bromeliads may show two different regimes, determined by the bromeliad ability in taking up nutrients from the water and by the total amount of light entering the tank. We concluded that predicted climate changes might promote regime shifts in tropical aquatic ecosystems by shaping their structure and the relative importance of other regulating factors. PMID:28422988

Natural depuration rate and concentration of cesium-137 radionuclide in black SEA macro algae

International Nuclear Information System (INIS)

Topcuoglu, S.; Kuecuekcezzar, R.; Kut, D.; Esen, N.; Gueven, K.C.

1996-01-01

Cesium-137 concentrations in red, brown and green algae have been studied for the calculation of natural depuration rates. The algae species were collected from the same population of the Black Sea stations during the period of 1986-1995. The natural depuration rates are estimated as biological half-lives. The pattern of depuration results represented by a single component for each algae division. The biological half-lives of 137 Cs in red (Phyllophora nervosa), green (Chaetomorpha linum) and brown (cystoceira barbata) algae are estimated to be 18.5, 21.6 and 29.3 months, respectively. 137 Cs and 40 K activity levels and their ratios in algae species in two stations in Black Sea region of Turkey have been determined during the period of 1990-1995. The results showed that the Sinop region was more contaminated than the Sile region on the Black Sea coast of Turkey from the Chernobyl accident. (author). 10 refs., 2 figs., 2 tabs

Algae. LC Science Tracer Bullet.

Science.gov (United States)

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…

Aquatic weeds: their implications in Indian nuclear industry

International Nuclear Information System (INIS)

Rao, T.S.; Anup Kumar, B.; Aruna Jyothi, K.; Satpathy, K.K.

2000-01-01

The aquatic weed infestation of KAPS cooling water system, MAPS open reservoir, and the growth of filamentous algae and bacteria in the feed water unit of HWP (Kota), was investigated. The aquatic weeds identified were: Ceratophyllum, Elodea, Hydrilla verticillata, Najas and Vallisneria species. However, at HWP (Kota) filamentous alga (Nostoc punchiformis) and bacteria (Sphaerotilus natans) were found in plenty. The metabolic products when assayed in the form of total carbohydrate content released by weeds was 3.7 mg gm -1 biomass. The metabolic products adsorb on to the resin matrix and impaired its performance at HWP (K), enhanced bacterial growth on the resin beads and furthered resin deterioration. Besides, the growth of aquatic weeds also influenced the pH of the cooling water, thereby vitiating the water treatment programme. (author)

Analysis of micro matter reference materials of lichen and algae by SRXRF and PIXE

International Nuclear Information System (INIS)

Yin Sha Xin; Wang Jian Liu; Zhang Peiqun

2002-01-01

In the present work two nuclear micro analysis techniques, synchrotron radiation (SRXRF) and macro proton induced X ray emission (macro PIXE), were used in the homogeneity test of Algae IAEA-413 and Lichen IAEA-338, and the certification of their elemental contents too. Finally, the Ingamell's sampling constant Ks and the relative homogeneity factor HE of some elements in these two RMs were estimated on the base of our macro PIXE results. (author)

Interaction between the macrophyte Stratiotes aloides and filamentous algae: does it indicate allelopathy?

NARCIS (Netherlands)

Mulderij, G.; Mau, B.; De Senerpont Domis, L.N.; Smolders, A.J.P.; Van Donk, E.

2009-01-01

The aquatic macrophyte Stratiotes aloides Linnaeus, which has recently received attention in studies on allelopathy, has been shown to suppress phytoplankton growth. In the Netherlands, S. aloides often co-occurs with floating filamentous algae. However, filamentous algae are generally absent in

THE ABILITY OF LEAVES AND RHIZOMES OF AQUATIC PLANTS TO ACCUMULATE MACRO- AND MICRONUTRIENTS

Directory of Open Access Journals (Sweden)

Agnieszka Edyta Parzych

2015-06-01

Full Text Available The samples of macrophytes and bottom sediments originated from the littoral zone of the Słupia River were collected in summer 2013. The aim of this study was to compare the properties of the accumulation of leaves and rhizomes of Glyceria maxima, Phragmites australis, Typha latifolia and Phalaris arundinacea for macro- and micronutrients. The largest quantities of macroelements were found in the leaves of the examined species, and microelements dominated the rhizomes of most examined macrophytes except for Mn in P.australis and T.latifolia. The obtained results show that N and K dominated in the leaves of P.arundinacea, P and Mg in the leaves of P.australis, and Ca in the leaves of G.maxima. The largest quantities of N, P and K were cumulated in the rhizomes of P.arundinacea, while Mg and Ca in the rhizome of T.latifolia. The leaves of aquatic plants accumulated from 1354.9 mmolc·kg-1 (T.latifolia to 1844.0 mmolc·kg-1 (P.arundinacea, and rhizomes from 985.8 mmolc·kg-1 (G.maxima to 1335.2 mmolc·kg-1 (P.arundinacea of all the analyzed components. In these species of macrophytes lower accumulated value of the sum of macro- and microelements were found in the rhizomes. The share of nitrogen was 42.4–59.8% of this amount, phosphorus 4.3–8.6%, potassium 22.8–35.1%, calcium from 2,6% to 12.4%, magnesium 3.0–7.5%, and heavy metals were from 0.6% (G.maxima to 1.2% (T.latifolia in leaves and from 2.2% (T.latifolia to 8.7% (G.maxima in rhizomes.

Aquatic Resources of Rocky Mountain Arsenal Adams County, Colorado

Science.gov (United States)

1989-09-01

Consequently, temperatures rise and oxygen levels fall. Primary producers in these stretches shift from periphyton to phytoplankton (suspended algae ...trees and have rocky substrates. Primary production in these cold- water and coolwater reaches is generally limited to periphyton (attached algae ...Adams County. Biotic components investigated included phytoplankton , zooplankton, aquatic macrophytes, benthic macroinvertebrates, fish eggs and

Characterization of phosphorus forms in lake macrophytes and algae by solution 31P nuclear magnetic resonance spectroscopy

Science.gov (United States)

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...

Composition, Occurrences and Checklist of Periphyton Algae of ...

African Journals Online (AJOL)

`123456789jkl''''#

The periphyton is also an important indicator of water quality (Azim et al, 2006). Attached algae are primitive plants that get their nutrients from water passing over them. ... rung in the aquatic food chain depend directly ... influence of sea water.

The occurrence of hormesis in plants and algae

DEFF Research Database (Denmark)

Cedergreen, Nina; Streibig, Jens Carl; Kudsk, Per

2007-01-01

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

Macro-Invertebrate Decline in Surface Water Polluted with Imidacloprid : A Rebuttal and Some New Analyses

NARCIS (Netherlands)

Vijver, M.G.; Brink, van den P.J.

2014-01-01

Imidacloprid, the largest selling insecticide in the world, has received particular attention from scientists, policymakers and industries due to its potential toxicity to bees and aquatic organisms. The decline of aquatic macro-invertebrates due to imidacloprid concentrations in the Dutch surface

Macro-Invertebrate Decline in surface water polluted with Imidacloprid: A rebuttal and soome new analyses

NARCIS (Netherlands)

Vijver, M.G.; Brink, van den P.J.

2014-01-01

Imidacloprid, the largest selling insecticide in the world, has received particular attention from scientists, policymakers and industries due to its potential toxicity to bees and aquatic organisms. The decline of aquatic macro-invertebrates due to imidacloprid concentrations in the Dutch surface

[Ecological Effects of Algae Blooms Cluster: The Impact on Chlorophyll and Photosynthesis of the Water Hyacinth].

Science.gov (United States)

Liu, Guo-feng; He, Jun; Yang, Yi-zhong; Han, Shi-qun

2015-08-01

The response of chlorophyll and photosynthesis of water hyacinth leaves in different concentrations of clustered algae cells was studied in the simulation experiment, and the aim was to reveal the mechanism of the death of aquatic plants during algae blooms occurred through studying the physiological changes of the macrophytes, so as to play the full function of the ecological restoration of the plants. And results showed the dissolved oxygen quickly consumed in root zone of aquatic plants after algae blooms gathered and showed the lack of oxygen (DO algae cell died and concentration of DTN in treatment 1 and 2 were 44.49 mg x L(-1) and 111.32 mg x L(-1), and the content of DTP were 2.57 mg x L(-1) and 9.10 mg x L(-1), respectively. The NH4+ -N concentrations were as high as 32.99 mg x L(-1) and 51.22 mg x L(-1), and the root zone with the anoxia, strong reducing, higher nutrients environment had a serious stress effects to the aquatic plants. The macrophytes photosynthesis reduced quickly and the plant body damaged with the intimidation of higher NH4+ -N concentration (average content was 45.6 mg x L(-1)) and hypoxia after algae cell decomposed. The average net photosynthesis rate, leaf transpiration rate of the treatment 2 reduced to 3.95 micromol (M2 x S)(-1), 0.088 micromol x (m2 x s)(-1), and only were 0.18 times, 0.11 times of the control group, respectively, at the end of the experiment, the control group were 22 micromol x (m2 x s)(-1), 0.78 micromol x (M2 x s)(-1). Results indicated the algae bloom together had the irreversible damage to the aquatic plants. Also it was found large amounts of new roots and the old roots were dead in the treatment 1, but roots were all died in the treatment 2, and leaves were yellow and withered. Experiment results manifested that the serious environment caused by the algae blooms together was the main reason of the death of aquatic plants during the summer. So in the practice of ecological restoration, it should avoid the

The attached algae community near Pickering GS: III

International Nuclear Information System (INIS)

McKinley, S.R.

1982-01-01

The relationship between attached algae and macro-invertebrates in the nearshore zone of Lake Ontario was investigated in the vicinity of the Pickering 'A' NGS. Measures of faunal density, richness, evenness, and biomass were generally higher from areas which supported attached algae. Gammarus fasciatus, Cricotopus bicinctus, Dicrotendipes spp., Orthocladius obumbratus, Cladotanytarsus spp., Orthocladius spp., and Parakiefferiella spp., were significantly correlated with algal standing crop. All of the above dominant invertebrates ingested epiphytes associated with Cladophora glomerata. Attempts to explain the distribution of the zoobenthic assemblages using the physical/biological characteristics of the study area indicated algal cover, substrate size, wind velocity and water temperature were most important

Preliminary study of some environmental and ecological aspects of the communities of fish and aquatic macro-invertebrates in the Tutunendo River, Choco, Colombia

International Nuclear Information System (INIS)

Torres, Yenecith; Roldan, Gabriel; Asprilla, Sonia; Rivas, Tulia Sofia

2006-01-01

From June to October 2003 studies related to environmental and ecological aspects of fishes and macro-invertebrates in three sampling stations of Tutunendo River located in the Department of Choco, Colombia, were carried out. Abiotic factors like conductivity, pH, oxygen and temperature were also measured. Eighty one hundred fish specimens, belonging to three orders, seven families and twelve species were collected. The order Siluriformes presented the greatest abundance (70.72%) with three families, seven species and 128 specimens, followed by Characiformes with three families, three species and 43 specimens (23.53%). At the same time 1.211 aquatic macro-invertebrates were collected represented by the orders Ephemeroptera (50.28%), Odonata (11.40%), Coleoptera (8.67%), Hemiptera (8.42%), Trichoptera (7.30%), Plecoptera (5.7%), Megaloptera (3.3%), Lepidoptera (2.31%), Diptera (0.37%) and Haplotaxida (0.08%). The families Leptophlebiidae (37.24%), followed by Naucoridae (8.42%) and Baetidae (8%) were the most represented. Relationship between fishes and macro invertebrates as food items in Geophagus pellegrini and Astyanaxfasciatus were also studied. G. pellegrini was zooplanctophage with preference for Baetidae, Leptohyphidae, Hydrobiosidae, Leptoceridae and Naucoridae. Finally, the present work indicated that Tutunendo town does not have potential fishery; the economy is supported in productive traditional systems based in the agriculture, complemented with fishery and extractive activities

Radiokinetic study in betony marine algae

International Nuclear Information System (INIS)

Azevedo Gouvea, V. de.

1981-01-01

The influx and outflux kinetics of some radionuclides in algae of the Rio de Janeiro coastline, were studied in order to select bioindicators for radioactive contamination in aquatic media, due to the presence of Nuclear Power Stations. Bioassays of the concentration and loss of radionuclides such as 137 Cs, 51 Cr, 60 Co and 131 I were performed in 1000cm 3 aquarium under controlled laboratory conditions, using a single channel gamma counting system, to study the species of algae most frequently found in the region. The concentration and loss parameters for all the species and radionuclides studied were obtained from the normalized results. The loss parameters were computerwise adjusted using Powell's multiparametric method. (author)

Fertilization of Earth Ponds. III: Effects on Benthic Macro ...

African Journals Online (AJOL)

Organic fertilizers in form of cow and chicken manure were applied in oligotrophic or unproductive pond water over a period of one year to stimulate the production of benthic macro invertebrates for the benefit of trout culture, while maintaining adequate water quality. Development of aquatic macrophytes during both ...

Phytotoxicity, bioaccumulation and degradation of isoproturon in green algae.

Science.gov (United States)

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

2012-12-01

Isoproturon (IPU) is a pesticide used for protection of land crops from weed or pathogen attack. Recent survey shows that IPU has been detected as a contaminant in aquatic systems and may have negative impact on aquatic organisms. To understand the phytotoxicity and potential accumulation and degradation of IPU in algae, a comprehensive study was performed with the green alga Chlamydomonas reinhardtii. Algae exposed to 5-50 μg L(-1) IPU for 3d displayed progressive inhibition of cell growth and reduced chlorophyll fluorescence. Time-course experiments with 25 μg L(-1) IPU for 6d showed similar growth responses. The 72 h EC50 value for IPU was 43.25 μg L(-1), NOEC was 5 μg L(-1) and LOEC was 15 μg L(-1). Treatment with IPU induced oxidative stress. This was validated by a group of antioxidant enzymes, whose activities were promoted by IPU exposure. The up-regulation of several genes coding for the enzymes confirmed the observation. IPU was shown to be readily accumulated by C. reinhardtii. However, the alga showed a weak ability to degrade IPU accumulated in its cells, which was best presented at the lower concentration (5 μg L(-1)) of IPU in the medium. The imbalance of accumulation and degradation of IPU may be the cause that resulted in the detrimental growth and cellular damage. Copyright © 2012 Elsevier B.V. All rights reserved.

Mapping Aquatic Vegetation in a Large, Shallow Eutrophic Lake: A Frequency-Based Approach Using Multiple Years of MODIS Data

Directory of Open Access Journals (Sweden)

Xiaohan Liu

2015-08-01

Full Text Available Aquatic vegetation serves many important ecological and socioeconomic functions in lake ecosystems. The presence of floating algae poses difficulties for accurately estimating the distribution of aquatic vegetation in eutrophic lakes. We present an approach to map the distribution of aquatic vegetation in Lake Taihu (a large, shallow eutrophic lake in China and reduce the influence of floating algae on aquatic vegetation mapping. Our approach involved a frequency analysis over a 2003–2013 time series of the floating algal index (FAI based on moderate-resolution imaging spectroradiometer (MODIS data. Three phenological periods were defined based on the vegetation presence frequency (VPF and the growth of algae and aquatic vegetation: December and January composed the period of wintering aquatic vegetation; February and March composed the period of prolonged coexistence of algal blooms and wintering aquatic vegetation; and June to October was the peak period of the coexistence of algal blooms and aquatic vegetation. By comparing and analyzing the satellite-derived aquatic vegetation distribution and 244 in situ measurements made in 2013, we established a FAI threshold of −0.025 and VPF thresholds of 0.55, 0.45 and 0.85 for the three phenological periods. We validated the accuracy of our approach by comparing the results between the satellite-derived maps and the in situ results obtained from 2008–2012. The overall classification accuracy was 87%, 81%, 77%, 88% and 73% in the five years from 2008–2012, respectively. We then applied the approach to the MODIS images from 2003–2013 and obtained the total area of the aquatic vegetation, which varied from 265.94 km2 in 2007 to 503.38 km2 in 2008, with an average area of 359.62 ± 69.20 km2 over the 11 years. Our findings suggest that (1 the proposed approach can be used to map the distribution of aquatic vegetation in eutrophic algae-rich waters and (2 dramatic changes occurred in the

Effect of ultraviolet radiation on laboratory cultures of green algae and cyanobacteria

International Nuclear Information System (INIS)

Palffy, K.; Ordog, V.; Voros, L.

2004-01-01

Since the discovery of the ozone hole, an increasing amount of work has been devoted to measuring the impact of the UV-radiation on living organisms. In this point of view, algae as the primer producers of aquatic ecosystems, get to the central part of the interest. The aim of the study was to study the effect of ultraviolet radiation on laboratory cultures of green algae and cyanobacteria

Aquatic indicator organisms as a tool to monitor discharges from nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Outola, Iisa; Vartti, Vesa-Pekka; Klemola, Seppo [STUK - Radiation and Nuclear Safety Authority, P.O. Box 14, 00881 Helsinki (Finland)

2014-07-01

There are four operating nuclear power plant units in Finland at two separate locations. The units started operation during 1977-1980. The surveillance of radioactive substances in the vicinities of the nuclear power plant is carried out under the permanent monitoring programs. Some 1000 samples are taken annually from the surroundings of the power plants to confirm that the discharges from the power plants are within permissible release limits and to monitor the dispersion of discharges in the environment. Aquatic indicator organisms (macro-algae, periphyton, mussels, crustacean, submerged aquatic plants) are included in the monitoring program. The indicator organisms are valuable monitoring objects both in normal and emergency situations because they accumulate effectively and often very rapidly radioactive substances from the medium. Six different species (Periphyton, Fucus vesiculosus, Myriophyllum spicatum, Potamogeton pectinatus, Saduria entomon, Macoma Baltica/Mytilus edulis) are collected regularly. Number of sampling location for each species varies from 1 to 7. Some species are collected continuously, some 1-2 times in a year. In this study we have evaluated the monitoring results for the aquatic indicator organisms for the period of 2005-2010 concerning concentration of discharge nuclides. Our aim was to answer the following questions using the monitoring data from aquatic organisms: 1) Which radionuclides are released to the marine environment and how often do we detect them? 2) How far from the nuclear power plants discharge radionuclides are detected? 3) How concentration of discharge radionuclides has changed with time in aquatic organisms? The number of discharge nuclides detected in the aquatic indicator samples was 11. Most of them were only detected in few samples, but {sup 58}Co, {sup 60}Co, {sup 54}Mn and {sup 110m}Ag were detected more frequently. Most of the observations above detection limits were made within the 5 km distance from the

Batch and column studies on biosorption of acid dyes on fresh water macro alga Azolla filiculoides.

Science.gov (United States)

Padmesh, T V N; Vijayaraghavan, K; Sekaran, G; Velan, M

2005-10-17

The biosorption of Acid red 88 (AR88), Acid green 3 (AG3) and Acid orange 7 (AO7) by deactivated fresh water macro alga Azolla filiculoides was investigated in batch mode. Langmuir and Freundlich adsorption models were used for the mathematical description of the batch biosorption equilibrium data and model constants were evaluated. The adsorption capacity was pH dependent with a maximum value of 109.0 mg/g at pH 7 for AR88, 133.5 mg/g at pH 3 for AG3 and 109.6 mg/g at pH 3 for AO7, respectively, was obtained. The pseudo first and second order kinetic models were also applied to the experimental kinetic data and high correlation coefficients favor pseudo second order model for the present systems. The ability of A. filiculoides to biosorb AG3 in packed column was also investigated. The column experiments were conducted to study the effect of important design parameters such as initial dye concentration (50-100 mg/L), bed height (15-25 cm) and flow rate (5-15 mL/min) to the well-adsorbed dye. At optimum bed height (25 cm), flow rate (5 mL/min) and initial dye concentration (100 mg/L), A. filiculoides exhibited 28.1mg/g for AG3. The Bed Depth Service Time model and the Thomas model were used to analyze the experimental data and the model parameters were evaluated.

Development of biotic ligand models for chronic manganese toxicity to fish, invertebrates, and algae.

Science.gov (United States)

Peters, Adam; Lofts, Stephen; Merrington, Graham; Brown, Bruce; Stubblefield, William; Harlow, Keven

2011-11-01

Ecotoxicity tests were performed with fish, invertebrates, and algae to investigate the effect of water quality parameters on Mn toxicity. Models were developed to describe the effects of Mn as a function of water quality. Calcium (Ca) has a protective effect on Mn toxicity for both fish and invertebrates, and magnesium (Mg) also provides a protective effect for invertebrates. Protons have a protective effect on Mn toxicity to algae. The models derived are consistent with models of the toxicity of other metals to aquatic organisms in that divalent cations can act as competitors to Mn toxicity in fish and invertebrates, and protons act as competitors to Mn toxicity in algae. The selected models are able to predict Mn toxicity to the test organisms to within a factor of 2 in most cases. Under low-pH conditions invertebrates are the most sensitive taxa, and under high-pH conditions algae are most sensitive. The point at which algae become more sensitive than invertebrates depends on the Ca concentration and occurs at higher pH when Ca concentrations are low, because of the sensitivity of invertebrates under these conditions. Dissolved organic carbon concentrations have very little effect on the toxicity of Mn to aquatic organisms. Copyright © 2011 SETAC.

Acute toxicity and associated mechanisms of four strobilurins in algae.

Science.gov (United States)

Liu, Xiaoxu; Wang, Yu; Chen, Hao; Zhang, Junli; Wang, Chengju; Li, Xuefeng; Pang, Sen

2018-04-03

Strobilurins have been reported highly toxic to non-target aquatic organisms but few illustrated how they cause toxic effects on algae. This study investigated the acute toxicity of Kresoxim-methy (KRE), Pyraclostrobin (PYR), Trifloxystrobin (TRI) and Picoxystrobin (PIC) on two algae and their toxicity mechanisms. Four strobilurins showed lower toxic effects on Chlorella pyrenoidsa but higher on Chlorella vulgaris. bc1 complex activities in C. vulgaris were significantly inhibited by all strobilurins, suggesting bc 1 complex might be the target of strobilurin toxicity in algae. Moreover, SOD, CAT and POD activities were significantly up-regulated by all doses of KRE, PYR and PIC. In contrast, low concentrations of TRI stimulated SOD and POD activities but highest concentration significantly inhibited those activities. Comet assays showed damaged DNA in C. vulgaris by four strobulirins, suggesting their potential genotoxic threats to algae. The results illustrated acute toxicity by strobulirins on algae and their possible toxicity mechanisms. Copyright © 2018 Elsevier B.V. All rights reserved.

Prehistoric Human-environment Interactions and Their Impact on Aquatic Ecosystems

Science.gov (United States)

Mackay, H.; Henderson, A. C. G.; van Hardenbroek, M.; Cavers, G.; Crone, A.; Davies, K. L.; Fonville, T. R.; Head, K.; Langdon, P. G.; Matton, R.; McCormick, F.; Murray, E.; Whitehouse, N. J.; Brown, A. G.

2017-12-01

One of the first widespread human-environment interactions in Scotland and Ireland occurred 3000 years ago when communities first inhabited wetlands, building artificial islands in lakes called crannogs. The reason behind the development and intermittent occupation of crannogs is unclear. We don't know if they were a response to changes in environment or if they were driven by societal influences. Furthermore, the impact of the construction, settlement and human activities on lake ecosystems is unknown, but is a key example of early anthropogenic signatures on the environment. Our research characterises the prehistoric human-environment interactions associated with crannogs by analysing geochemical and biological signals preserved within the crannog and wetland sediments. Records of anthropogenic activities and environmental change have been produced using lipid biomarkers of faecal matter, sedimentary DNA, and the remains of beetles, aquatic invertebrates (chironomids), siliceous algae (diatoms) and pollen. Results of these analyses reveal settlement occupations occurred in phases from the Iron Age to the Medieval Period. The main effects of occupation on the wetland ecosystems are nutrient-driven increases in productivity and shifts in aquatic species from clear water taxa to those associated with more eutrophic conditions. Crannog abandonment reduces nutrient inputs and therefore levels of aquatic productivity, as evidenced by decreases in the abundance of siliceous algae. Despite returns to pre-settlement nutrient and productivity levels, the lake ecosystems do not recover to their previous ecological state: dominant aquatic invertebrate and siliceous algae taxa shift in response to elevated levels of macrophytes within the lakes. Whilst these phase changes in lake ecosystems highlight their adaptive capacity to environmental change, the temporary human interactions associated with crannogs had persisting environmental impacts that shaped the long

Applicator Training Manual for: Aquatic Weed Control.

Science.gov (United States)

Herron, James W.

The aquatic weeds discussed in this manual include algae, floating weeds, emersed weeds, and submerged weeds. Specific requirements for pesticide application are given for static water, limited flow, and moving water situations. Secondary effects of improper application rates and faulty application are described. Finally, techniques of limited…

The subunits analysis of R-phycoerythrin from marine red algae by ...

African Journals Online (AJOL)

Subunit components of R-phycoerythrins (R-PEs) prepared from five marine macro red algae were analyzed by sodium dodecyl sulfate -polyarylamide gel electrophoresis (SDS-PAGE) and by isoelectric focusing (IEF) in pH gradients range of 3.0 to 9.5, 2.5 to 5.0 and 4.0 to 6.5. Riboflavin was used to catalyze ...

Seasonal abundance of epipelic algae and sediment parameters of ...

African Journals Online (AJOL)

Amadi-Ama creek is located close to sources of wastes which are introduced into the creek thus altering the physico-chemical parameters and the aquatic biota of the creek due to variation in nutrient load of the water. The seasonal abundance of epipelic algae and sediment parameters of Amadi-Ama Creek were ...

Corrigendum | Schramm | African Journal of Aquatic Science

African Journals Online (AJOL)

It is editorial policy of the African Journal of Aquatic Science to follow the revised Acacia nomenclature, based on the retypification of the genus ratified by the XVIII International Botanical Congress in Melbourne in 2011 and subsequently published in Appendix III of the International Code of Nomenclature for algae, fungi ...

Errors When Extracting Oil from Algae

Science.gov (United States)

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

Bioaccumulation study of acrylate monomers in algae (Chlorella Kessleri) by PY-GC and PY-GC/MS

International Nuclear Information System (INIS)

Halas, L.; Orinak, A.; Adamova, M.; Ladomersky, J.

2004-01-01

Acrylate monomers methylmethacrylate (MMA) and cyclohexylmethacrylate (CHMA) bioaccumulation has been determined in aquatic organism, algae (Chlorella kessleri). Algae were collected in amount of 0.4 mg and directly injected to the paralytic cell. In algae bodies accumulated monomers were analysed by pyrolysis gas chromatography (Py-GC) and pyrolysis gas chromatography coupled with mass spectrometry (Py-GC/MS). Traces of the accumulated monomers in algae body can be determined after 1-, 2 -, 3-weeks of incubation. Maximum content of MMA was determined after 3-week of experiment, contrariwise in the case of CHMA after 2-week exposition. Relationship with pyrolysis temperature has also been studied. (authors)

Are algae relevant to the detritus-based food web in tank-bromeliads?

Directory of Open Access Journals (Sweden)

Olivier Brouard

Full Text Available We assessed the occurrence of algae in five species of tank-bromeliads found in contrasting environmental sites in a Neotropical, primary rainforest around the Nouragues Research Station, French Guiana. The distributions of both algal abundance and biomass were examined based on physical parameters, the morphological characteristics of bromeliad species and with regard to the structure of other aquatic microbial communities held in the tanks. Algae were retrieved in all of the bromeliad species with mean densities ranging from ∼10(2 to 10(4 cells/mL. Their biomass was positively correlated to light exposure and bacterial biomass. Algae represented a tiny component of the detrital food web in shaded bromeliads but accounted for up to 30 percent of the living microbial carbon in the tanks of Catopsis berteroniana, located in a highly exposed area. Thus, while nutrient supplies are believed to originate from wind-borne particles and trapped insects (i.e., allochtonous organic matter, our results indicate that primary producers (i.e., autochtonous organic matter are present in this insectivorous bromeliad. Using a 24-h incubation of size-fractionated and manipulated samples from this plant, we evaluated the impact of mosquito foraging on algae, other microorganisms and rotifers. The prey assemblages were greatly altered by the predation of mosquito larvae. Grazing losses indicated that the dominant algal taxon, Bumilleriopsis sp., like protozoa and rotifers, is a significant part of the diet of mosquito larvae. We conclude that algae are a relevant functional community of the aquatic food web in C. berteroniana and might form the basis of a complementary non-detrital food web.

Macro-invertebrate decline in surface water polluted with imidacloprid.

Directory of Open Access Journals (Sweden)

Tessa C Van Dijk

Full Text Available Imidacloprid is one of the most widely used insecticides in the world. Its concentration in surface water exceeds the water quality norms in many parts of the Netherlands. Several studies have demonstrated harmful effects of this neonicotinoid to a wide range of non-target species. Therefore we expected that surface water pollution with imidacloprid would negatively impact aquatic ecosystems. Availability of extensive monitoring data on the abundance of aquatic macro-invertebrate species, and on imidacloprid concentrations in surface water in the Netherlands enabled us to test this hypothesis. Our regression analysis showed a significant negative relationship (P<0.001 between macro-invertebrate abundance and imidacloprid concentration for all species pooled. A significant negative relationship was also found for the orders Amphipoda, Basommatophora, Diptera, Ephemeroptera and Isopoda, and for several species separately. The order Odonata had a negative relationship very close to the significance threshold of 0.05 (P = 0.051. However, in accordance with previous research, a positive relationship was found for the order Actinedida. We used the monitoring field data to test whether the existing three water quality norms for imidacloprid in the Netherlands are protective in real conditions. Our data show that macrofauna abundance drops sharply between 13 and 67 ng l(-1. For aquatic ecosystem protection, two of the norms are not protective at all while the strictest norm of 13 ng l(-1 (MTR seems somewhat protective. In addition to the existing experimental evidence on the negative effects of imidacloprid on invertebrate life, our study, based on data from large-scale field monitoring during multiple years, shows that serious concern about the far-reaching consequences of the abundant use of imidacloprid for aquatic ecosystems is justified.

Quantitative structure-activity relationships for green algae growth inhibition by polymer particles.

NARCIS (Netherlands)

Nolte, Tom M; Peijnenburg, Willie J G M; Hendriks, A Jan; van de Meent, Dik

After use and disposal of chemical products, many types of polymer particles end up in the aquatic environment with potential toxic effects to primary producers like green algae. In this study, we have developed Quantitative Structure-Activity Relationships (QSARs) for a set of highly structural

Benthic algae compensate for phytoplankton losses in large aquatic ecosystems.

Science.gov (United States)

Brothers, Soren; Vadeboncoeur, Yvonne; Sibley, Paul

2016-12-01

Anthropogenic activities can induce major trophic shifts in aquatic systems, yet we have an incomplete understanding of the implication of such shifts on ecosystem function and on primary production (PP) in particular. In recent decades, phytoplankton biomass and production in the Laurentian Great Lakes have declined in response to reduced nutrient concentrations and invasive mussels. However, the increases in water clarity associated with declines in phytoplankton may have positive effects on benthic PP at the ecosystem scale. Have these lakes experienced oligotrophication (a reduction of algal production), or simply a shift in autotrophic structure with no net decline in PP? Benthic contributions to ecosystem PP are rarely measured in large aquatic systems, but our calculations based on productivity rates from the Great Lakes indicate that a significant proportion (up to one half, in Lake Huron) of their whole-lake production may be benthic. The large declines (5-45%) in phytoplankton production in the Great Lakes from the 1970s to 2000s may be substantially compensated by benthic PP, which increased by up to 190%. Thus, the autotrophic productive capacity of large aquatic ecosystems may be relatively resilient to shifts in trophic status, due to a redirection of production to the near-shore benthic zone, and large lakes may exhibit shifts in autotrophic structure analogous to the regime shifts seen in shallow lakes. © 2016 John Wiley & Sons Ltd.

Incidence and Management Costs of Freshwater Aquatic Nuisance Species at Projects Operated by the U.S. Army Corps of Engineers

Science.gov (United States)

2010-07-01

the occurrence of ANS impacts (Yes or No) from freshwater algae, large aquatic plants, fish, zebra mussels, Asiatic clams, water fleas, crayfish...2005. Freshwater aquatic nuisance species impacts and management costs and benefits at federal water resources projects. ERDC/TN ANSRP-06-3...ER D C/ EL T R- 10 -1 3 Aquatic Nuisance Species Research Program Incidence and Management Costs of Freshwater Aquatic Nuisance Species

An assessment of pollution in aquatic environment using bioindicators

African Journals Online (AJOL)

This review highlights the importance of biological indicators in monitoring presence of pollution in aquatic environment. This assessment involves the use of living organisms (macro or microorganisms and plants or animals) as bioindicators of pollution in water bodies. These organisms are believed to show higher ...

Research for Developing Renewable Biofuels from Algae

Energy Technology Data Exchange (ETDEWEB)

Black, Paul N. [Univ. of Nebraska, Lincoln, NE (United States)

2012-12-15

Task A. Expansion of knowledge related to lipid production and secretion in algae A.1 Lipid biosynthesis in target algal species; Systems biology approaches are being used in combination with recent advances in Chlorella and Chlamydomonas genomics to address lipid accumulation in response to defined nutrient regimes. The UNL Algal Group continues screening additional species of Chlorella and other naturally occurring algae for those with optimal triglyceride production; Of the strains examined by the DOE's Aquatic Species Program, green algae, several species of Chlorella represent the largest group from which oleaginous candidates have been identified; A.1.1. Lipid profiling; Neutral lipid accumulation is routinely monitored by Nile red and BODIPY staining using high throughput strategies to screen for naturally occurring algae that accumulate triglyceride. These strategies complement those using spectrofluorometry to quantify lipid accumulation; Neutral lipid accumulation is routinely monitored by high performance thin-layer chromatography (HPTLC) and high performance liquid chromatography (HPLC) of lipid extracts in conjunction with; Carbon portioning experiments have been completed and the data currently are being analyzed and prepared for publication; Methods in the Black lab were developed to identify and quantify triacylglycerol (TAG), major membrane lipids [diacylglycerol trimethylhomoserine, phosphatidylethanolamine and chloroplast glycolipids], biosynthetic intermediates such as diacylglycerol, phosphatidic acid and lysophospholipids and different species of acyl-coenzyme A (acyl CoA).

Plant pigment types, distributions, and influences on shallow water submerged aquatic vegetation mapping

Science.gov (United States)

Hall, Carlton R.; Bostater, Charles R., Jr.; Virnstein, Robert

2004-11-01

Development of robust protocols for use in mapping shallow water habitats using hyperspectral imagery requires knowledge of absorbing and scattering features present in the environment. These include, but are not limited to, water quality parameters, phytoplankton concentrations and species, submerged aquatic vegetation (SAV) species and densities, epiphytic growth on SAV, benthic microalgae and substrate reflectance characteristics. In the Indian River Lagoon, Fl. USA we conceptualize the system as having three possible basic layers, water column and SAV bed above the bottom. Each layer is occupied by plants with their associated light absorbing pigments that occur in varying proportions and concentrations. Phytoplankton communities are composed primarily of diatoms, dinoflagellates, and picoplanktonic cyanobacteria. SAV beds, including flowering plants and green, red, and brown macro-algae exist along density gradients ranging in coverage from 0-100%. SAV beds may be monotypic, or more typically, mixtures of the several species that may or may not be covered in epiphytes. Shallow water benthic substrates are colonized by periphyton communities that include diatoms, dinoflagellates, chlorophytes and cyanobacteria. Inflection spectra created form ASIA hyperspectral data display a combination of features related to water and select plant pigment absorption peaks.

Nano-plastics in the aquatic environment.

Science.gov (United States)

Mattsson, K; Hansson, L-A; Cedervall, T

2015-10-01

The amount of plastics released to the environment in modern days has increased substantially since the development of modern plastics in the early 1900s. As a result, concerns have been raised by the public about the impact of plastics on nature and on, specifically, aquatic wildlife. Lately, much attention has been paid to macro- and micro-sized plastics and their impact on aquatic organisms. However, micro-sized plastics degrade subsequently into nano-sizes whereas nano-sized particles may be released directly into nature. Such particles have a different impact on aquatic organisms than larger pieces of plastic due to their small size, high surface curvature, and large surface area. This review describes the possible sources of nano-sized plastic, its distribution and behavior in nature, the impact of nano-sized plastic on the well-being of aquatic organisms, and the difference of impact between nano- and micro-sized particles. We also identify research areas which urgently need more attention and suggest experimental methods to obtain useful data.

Ultrasound assisted direct transesterification of algae for biodiesel production : Analysis of emission characteristics

Directory of Open Access Journals (Sweden)

Namasivayam Manickam

2014-03-01

Full Text Available Recently, the algae-for-fuel concept has gained renewed interest with energy prices fluctuating widely. Due to some restrictions over the oil extraction from algae, direct transesterification may be considered as a good alternative. In this study, to improve the performance of direct transesterification, ultrasound induction was carried out. A sonicator probe was used to induce the direct transesterification of Cladophora fracta, a freshwater macro alga, which contains 14% lipid on dry biomass basis. Due to ultrasonication about 25% increased biodiesel yields were obtained and the biodiesel thus prepared was analyzed for emission characteristics. The analysis results showed that Cladophora biodiesel emits 18 mg/L of CO whereas petroleum diesel emits 50 mg/L. Similarly, the emission of NOx and particulate matter also were reduced to a considerable level. The Cladophora is a suitable source of biodiesel by ultrasound assisted direct transesterification in industrial level in the future.

Influence of reaction conditions on fast pyrolysis of macroalge

International Nuclear Information System (INIS)

Bae, Yoon Ju; Kim, Jung Hwan; Cho, Hye Jung; Ko, Jeong Huy; Heo, Hyeon Su; Park, Hye Jin; Park, Young Kwon

2010-01-01

Full text: The importance of renewable energy sources has increased rapidly due to the high international crude oil prices and environmental concerns over fossil fuel use. Recently, there has been a growing interest in aquatic biomass, especially marine macro algae, and a number of studies have been initiated to evaluate its potential for bio-energy. This paper reports a fast pyrolysis of macro algae under different reaction conditions such as pyrolysis temperature, particle size and sample quantity. Various macro algae such as Undaria pinnatifida, Laminaria japonica and Porphyra tenera were fast pyro lysed at temperatures between 300-600 degree Celsius in a batch reactor and the main product of bio-oil was obtained. The optimal reaction temperature for the production of bio-oil was 500 degree Celsius. At this temperature, the maximum bio-oil yields were 40.4 wt % ( by Undaria pinnatifida), 37.6 wt % (by Laminaria japonica) and 47.4 wt % (by Porphyra tenera), respectively. In particular, after pre-treatment with 2.0M HCl solution, the product yield of bio-oil was increased in macro algae, Undaria pinnatifida. The pyroylsis gases were analyzed by using GC-TCD and GC-FID and qualitative analyses of bio-oil were performed using GC-MS. The maximum yield of bio-oil, Undaria pinnatifida, Laminaria japonica and Porphyra tenera, was obtained at 500 degree Celsius (40.4 wt %, 37.6 wt % and 47.4 wt %, respectively). (author)

Tritium in the aquatic environment

International Nuclear Information System (INIS)

Blaylock, B.G.; Hoffman, F.O.; Frank, M.L.

1986-02-01

Tritium is of environmental importance because it is released from nuclear facilities in relatively large quantities and because it has a half life of 12.26 y. Most of the tritium released into the atmosphere eventually reaches the aqueous environment, where it is rapidly taken up by aquatic organisms. This paper reviews the current literature on tritium in the aquatic environment. Conclusions from the review, which covered studies of algae, aquatic macrophytes, invertebrates, fish, and the food chain, were that aquatic organisms incorporate tritium into their tissue-free water very rapidly and reach concentrations near those of the external medium. The rate at which tritium from tritiated water is incorporated into the organic matter of cells is slower than the rate of its incorporation into the tissue-free water. If organisms consume tritiated food, incorporation of tritium into the organic matter is faster, and a higher tritium concentration is reached than when the organisms are exposed to only tritiated water alone. Incorporation of tritium bound to molecules into the organic matter depends on the chemical form of the ''carrier'' molecule. No evidence was found that biomagnification of tritium occurs at higher trophic levels. Radiation doses from tritium releases to large populations of humans will most likely come from the consumption of contaminated water rather than contaminated aquatic food products

Iodine-129 in aquatic organisms near nuclear fuels processing plants

International Nuclear Information System (INIS)

Watson, D.G.

1975-04-01

Concentrations of 129 I in two aquatic habitats near nuclear fuel processing plants were highest in algae and crustaceans. These two forms may be useful in future monitoring of 129 I. There is some indication of an increase in atom ratios and specific activity in aquatic organisms over that in water and sediments. Additional measurements should be made to verify this conclusion. Efforts should continue to measure the possible long term build-up of 129 I in aquatic environments receiving effluents from fuels reprocessing plants. Even at very low rates of release to the environment, the long physical half-life of 129 I creates the potential for build-up of this nuclide to significant levels. (U.S.)

Aquatic plants are open flexible structures - a reply to Sukhodolov

DEFF Research Database (Denmark)

Sand-Jensen, K.

2005-01-01

1. Aquatic plant stands are flexible, mesh-like open structures that undergo modification in shape and experience a cascade of declining flow velocities and micro-scale Reynolds numbers with increasing distance into the stands. It is not possible to define or measure the frontal area of this open...... other problems. Relating drag coefficients to macro-scale Reynolds numbers would result in exactly the same form of relationship as to water velocity because macro-scale Reynolds numbers changed in direct proportion to water velocity in the experiments, while kinematic viscosity and characteristic...

Toxicity of nano-TiO2 on algae and the site of reactive oxygen species production.

Science.gov (United States)

Li, Fengmin; Liang, Zhi; Zheng, Xiang; Zhao, Wei; Wu, Miao; Wang, Zhenyu

2015-01-01

Given the extensive use of nanomaterials, they may enter aquatic environments and harm the growth of algae, which are primary producers in an aquatic ecosystem. Thus, the balance of an aquatic ecosystem may be destroyed. In this study, Karenia brevis and Skeletonema costatum were exposed to nano-TiO2 (anatase, average particle size of 5-10 nm, specific surface area of 210±10 m(2) g(-1)) to assess the effects of nano-TiO2 on algae. The findings of transmission electron microscopy-energy dispersive X-ray spectroscopy (TEM-EDX) and scanning electron microscopy (SEM) demonstrate aggregation of nano-TiO2 in the algal suspension. Nano-TiO2 was also found to be inside algal cells. The growth of the two species of algae was inhibited under nano-TiO2 exposure. The 72 h EC50 values of nano-TiO2 to K. brevis and S. costatum were 10.69 and 7.37 mg L(-1), respectively. TEM showed that the cell membrane of K. brevis was destroyed and its organelles were almost undistinguished under nano-TiO2 exposure. The malondialdehyde (MDA) contents of K. brevis and S. costatum significantly increased compared with those of the control (pTiO2 exposure was explored with the addition of inhibitors of different electron transfer chains. This study indicated that nano-TiO2 in algal suspensions inhibited the growth of K. brevis and S. costatum. This effect was attributed to oxidative stress caused by ROS production inside algal cells. The levels of anti-oxidative enzymes changed, which destroyed the balance between oxidation and anti-oxidation. Thus, algae were damaged by ROS accumulation, resulting in lipid oxidation and inhibited algae growth. The inhibitors of the electron transfer chain showed that the site of ROS production and accumulation in K. brevis cells was the chloroplast. Copyright © 2014 Elsevier B.V. All rights reserved.

Light dependence of quantum yields for PSII charge separation and oxygen evolution in eucaryotic algae

NARCIS (Netherlands)

Flameling, I.A.; Kromkamp, J.C.

1998-01-01

Quantum yields of photosystem II (PSII) charge separation (Phi(P)) and oxygen production (Phi(O2)) were determined by simultaneous measurements of oxygen production and variable fluorescence in four different aquatic microalgae representing three different taxonomic groups: the freshwater alga

Modeling of radiocesium transport kinetics in system water-aquatic plants

International Nuclear Information System (INIS)

Svadlenkova, M.

1988-01-01

Compartment models were used to describe the kinetics of the transport of radionuclides in the system water-biomass of aquatic plants. Briefly described are linear models and models with time variable parameters. The model was tested using data from a locality in the environs of the Bohunice nuclear power plant. Cladophora glomerata algae were the monitored plants, 137 Cs the monitored radionuclide. The models may be used when aquatic plants serve as bioindicators of the radioactive contamination of surface waters, for monitoring the transport of radionuclides in food chains. (M.D.). 10 refs

ALDUO(TM) Algae Cultivation Technology for Delivering Sustainable Omega-3s, Feed, and Fuel

Energy Technology Data Exchange (ETDEWEB)

Bai, Xuemei [Cellana LLC

2012-09-24

* ALDUO(TM) Algae Production Technology Cellana?s Proprietary, Photosynthetic, & Proven * ALDUO(TM) Enables Economic Algae Production Unencumbered by Contamination by Balancing Higher-Cost PBRs with Lower-Cost Open Ponds * ALDUO(TM) Advantages * ALDUO(TM) Today o Large collection of strains for high value co-products o Powerful Mid-scale Screening & Optimization System o Solution to a Conflicting Interest o Split Pond Yield Enhancement o Heterotrophy & mixotrophy as a "finishing step" o CO2 Mitigation-flue Gas Operation o Worldwide Feed Trials with Livestock & Aquatic Species * ALDUO(TM) Technology Summarized

Development of Green Fuels From Algae - The University of Tulsa

Energy Technology Data Exchange (ETDEWEB)

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.

Dynamic Low-Vacuum Scanning Electron Microscope Freeze Drying Observation for Fresh Water Algae

International Nuclear Information System (INIS)

Mohsen, H.T.; Ghaly, W.A.; Zahran, N.F.; Helal, A.I.

2010-01-01

A new perpetration method for serving in dynamic examinations of the fresh water algae is developed in connection with the Low-Vacuum Scanning Electron Microscope (LV-SEM) freeze drying technique. Specimens are collected from fresh water of Ismailia channel then transferred directly to freeze by liquid nitrogen and dried in the chamber of the scanning electron microscope in the low vacuum mode. Scanning electron micrographs revealed that the drying method presented the microstructure of algae. Dehydration in a graded ethanol series is not necessary in the new method. Dried algae specimen is observed in SEM high vacuum mode after conductive coating at higher resolution. Low-vacuum SEM freeze drying technique is a simple, time-saving and reproducible method for scanning electron microscopy that is applicable to various aquatic microorganisms covered with soft tissues.

Effect of chemically and biologically synthesized Ag nanoparticles on the algae growth inhibition

Science.gov (United States)

Anna, Mražiková; Oksana, Velgosová; Jana, Kavuličová

2017-12-01

Over the past few years green methods for preparation of silver nanoparticles has become necessary due to its friendly influence on ecosystem. In the present work antimicrobial properties of biologically synthesized silver nanoparticles (Bio-AgNPs) using green algae extract and chemically synthesized silver nanoparticles (Chem-AgNPs) using sodium citrate against algae Parachlorella kessleri is investigated. Both used Bio-AgNPs and Chem-AgNPs exhibit long-term stability as demonstrated by UV-vis spectroscopy measurements. The results revealed stronger toxic effects of Bio-AgNPs on agar plates what was confirmed clear inhibition zone around wells impregnated with Bio-AgNPs. On the other hand Bio-AgNPs were confirmed to be less toxic in aquatic environments for the growths of green algae P. kessleri comparing to Chem-AgNPs.

Algogroup: Towards a Shared Vision of the Possible Deployment of Algae to Biofuels

International Nuclear Information System (INIS)

Montagne, Xavier; Porot, Pierre; Aymard, Caroline; Querleu, Cecile; Bouter, Anne; Lorne, Daphne; Cadoret, Jean-Paul; Lombaert-Valot, Isabelle; Petillon, Odile

2013-01-01

A strong interest has been focused from several years on the algae pathway for energy production, especially for transportation fuels called third generation bio-fuel or G3 bio-fuel, and mainly from microalgae route, considering it could be a high potential alternative strategy for renewable energy and fuel production. Algae, and especially microalgae, present significant advantages compared with land resources, such as much higher productivity and lack of competition with food applications. Nevertheless, based on current knowledge, the production of an algae biomass for energy remains a difficult target to reach, due to the numerous existing hurdles such as the energetic yield and the economic positioning, without neglecting the environmental and societal aspect. G3 bio-fuel processes are far from the industrialization step. In 2010, under the initiative of IFP Energies Nouvelles, Airbus, Safran, EADS IW and the Academie des Technologies, launched a French national study of the potential of the algae sector as resources for the so called G3 bio-fuel production. This study was called 'Algogroup' and led by IFP Energies Nouvelles. The objective was to obtain a shared vision of the deployment possibilities. It led to the creation of this Algogroup task force with the previous partners, adding Sofiproteol, INRA, IFREMER, CEVA and the Agrimip pole. Algogroup has explored several axes, which enabled a thorough analysis of the potentials and limits of the technology: from the species selection to the harvesting (lipid extraction/recovery), including environmental and economical aspects. This paper focuses on some main aspects of the Algogroup study related to economical positioning and environmental terms, specially Life Cycle Analysis (LCA). A large share of the work was dedicated to microalgae, but since it was also considered important to examine the potential role of macro-algae, a specific analysis was conducted on this aspect. It has enabled the group to issue some

Ecological Effects of Exotic and Native Aquatic Vegetation

Science.gov (United States)

2009-08-01

related problem for fish. Normally, carbon dioxide released during respiration is utilized in photosynthesis or escapes into the atmo- sphere...with algae for nutrients and light (Boyd 1979). Phytoplankton populations are often suppressed in well-established stands of ERDC/EL TR-09-10 8...aquatic plants, and primary productivity is either dependent upon macrophytes and/or periphyton associated with them. Generally, the presence of

Temperature influence on chemical toxicity to aquatic organisms

International Nuclear Information System (INIS)

Cairns, J. Jr.; Heath, A.G.; Parker, B.C.

1975-01-01

The literature on the effects of temperature on chemical toxicity to aquatic animals and microorganisms is reviewed. Microbial photosynthesis and respiration is briefly discussed. It is concluded that there is a paucity of information on the inter-relations of temperature and toxicants to algae, bacteria, and protozoa and that standards based on the in situ response of indigenous organisms to specific discharge areas should be developed

Desiccation stress and tolerance in green algae: consequences for ultrastructure, physiological and molecular mechanisms

Science.gov (United States)

Holzinger, Andreas; Karsten, Ulf

2013-01-01

Although most green algae typically occur in aquatic ecosystems, many species also live partly or permanently under aeroterrestrial conditions, where the cells are exposed to the atmosphere and hence regularly experience dehydration. The ability of algal cells to survive in an air-dried state is termed desiccation tolerance. The mechanisms involved in desiccation tolerance of green algae are still poorly understood, and hence the aim of this review is to summarize recent findings on the effects of desiccation and osmotic water loss. Starting from structural changes, physiological, and biochemical consequences of desiccation will be addressed in different green-algal lineages. The available data clearly indicate a range of strategies, which are rather different in streptophycean and non-streptophycean green algae. While members of the Trebouxiophyceae exhibit effective water loss-prevention mechanisms based on the biosynthesis and accumulation of particular organic osmolytes such as polyols, these compounds are so far not reported in representatives of the Streptophyta. In members of the Streptophyta such as Klebsormidium, the most striking observation is the appearance of cross-walls in desiccated samples, which are strongly undulating, suggesting a high degree of mechanical flexibility. This aids in maintaining structural integrity in the dried state and allows the cell to maintain turgor pressure for a prolonged period of time during the dehydration process. Physiological strategies in aeroterrestrial green algae generally include a rapid reduction of photosynthesis during desiccation, but also a rather quick recovery after rewetting, whereas aquatic species are sensitive to drying. The underlying mechanisms such as the affected molecular components of the photosynthetic machinery are poorly understood in green algae. Therefore, modern approaches based on transcriptomics, proteomics, and/or metabolomics are urgently needed to better understand the molecular

Desiccation stress and tolerance in green algae: Consequences for ultrastructure, physiological and molecular mechanisms

Directory of Open Access Journals (Sweden)

Andreas eHolzinger

2013-08-01

Full Text Available Although most green algae typically occur in aquatic ecosystems, many species also live partly or permanently under aeroterrestrial conditions, where the cells are exposed to the atmosphere and hence regularly experience dehydration. The ability of algal cells to survive in an air-dried state is termed desiccation tolerance. The mechanisms involved in desiccation tolerance of green algae are still poorly understood, and hence the aim of this review is to summarize recent findings on the effects of desiccation and osmotic water loss. Starting from structural changes, physiological and biochemical consequences of desiccation will be addressed in different green-algal lineages. The available data clearly indicate a range of strategies, which are rather different in streptophycean and non-streptophycean green algae. For example, Trebouxiophyceae exhibit effective water loss-prevention mechanisms based on the biosynthesis and accumulation of particular organic osmolytes such as polyols, these compounds are so far not reported in representatives of the Streptophyta. In members of the Streptophyta such as Klebsormidium, the most striking observation is the appearance of cross-walls in desiccated samples, which are strongly undulating, suggesting a high degree of mechanical flexibility. This allows the cell to maintain turgor pressure for a prolonged period of time during the dehydration process. Physiological strategies in aeroterrestrial green algae generally include a rapid reduction of photosynthesis during desiccation, but also a rather quick recovery after rewetting, whereas aquatic species are sensitive to drying. The underlying mechanisms such as the affected molecular components of the photosynthetic machinery are poorly understood in green algae. Therefore, modern approaches based on transcriptomics, proteomics and/or metabolomics are urgently needed to better understand the molecular mechanisms involved in desiccation-stress physiology of

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

Science.gov (United States)

Aleem, A. A.

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

Influence of benthic macro-invertebrate bioturbation on the biogeochemical behaviour of uranium within freshwater sediments

International Nuclear Information System (INIS)

Lagauzere, S.

2008-06-01

In freshwater ecosystems, sediments act as an accumulation compartment for metallic pollutants as uranium. Secondary, there can also represent endogenous sources of contamination by resuspension (e.g. flood, bioturbation) or changes of metal speciation that acts upon their bioavailability. Indeed, metallic compounds can be transformed in more or less toxic or inert compounds through physico-chemical (e.g. pH, redox conditions, ionic force) and microbiological variations. These conditions are themselves under the effects of benthic macro-invertebrate activities via bioturbation processes. The main objective of this PhD was to determinate the influence of two benthic macro-invertebrate species (Chironomus riparius and Tubifex tubifex) on the distribution and the transfers of uranium within freshwater sediments. To reach this goal, laboratory experiments were performed in order to (i) assess the effects of uranium on benthic macro-invertebrates, more particularly on their bioturbation activity, (ii) determine the influence of these organisms on uranium behaviour through high resolution physico-chemical measurements (e.g. oxygen optodes, DET gel probes), and (iii) estimate the consequences of these interactions on pelagic organisms via genotoxicity measurements (micronuclei assay and molecular bio-markers analysis on Xenopus laevis). The results demonstrate that bioturbation intensity of macro-invertebrates can be affected in uranium-contaminated sediments, but the two species studied in this work show a relative tolerance. For high uranium concentrations (>100 times the geochemical background level), corresponding however to realistic concentrations in highly contaminated sites, T. tubifex worms are able to maintain a sufficient bioturbation activity that induces a high remobilization of uranium initially associated with sediments to the overlying water (factor 2 to 10). That represents therefore a potential risk for the remaining aquatic biocenose. However, by

Aura-biomes are present in the water layer above coral reef benthic macro-organisms

Directory of Open Access Journals (Sweden)

Kevin Walsh

2017-08-01

Full Text Available As coral reef habitats decline worldwide, some reefs are transitioning from coral- to algal-dominated benthos with the exact cause for this shift remaining elusive. Increases in the abundance of microbes in the water column has been correlated with an increase in coral disease and reduction in coral cover. Here we investigated how multiple reef organisms influence microbial communities in the surrounding water column. Our study consisted of a field assessment of microbial communities above replicate patches dominated by a single macro-organism. Metagenomes were constructed from 20 L of water above distinct macro-organisms, including (1 the coral Mussismilia braziliensis, (2 fleshy macroalgae (Stypopodium, Dictota and Canistrocarpus, (3 turf algae, and (4 the zoanthid Palythoa caribaeorum and were compared to the water microbes collected 3 m above the reef. Microbial genera and functional potential were annotated using MG-RAST and showed that the dominant benthic macro-organisms influence the taxa and functions of microbes in the water column surrounding them, developing a specific “aura-biome”. The coral aura-biome reflected the open water column, and was associated with Synechococcus and functions suggesting oligotrophic growth, while the fleshy macroalgae aura-biome was associated with Ruegeria, Pseudomonas, and microbial functions suggesting low oxygen conditions. The turf algae aura-biome was associated with Vibrio, Flavobacterium, and functions suggesting pathogenic activity, while zoanthids were associated with Alteromonas and functions suggesting a stressful environment. Because each benthic organism has a distinct aura-biome, a change in benthic cover will change the microbial community of the water, which may lead to either the stimulation or suppression of the recruitment of benthic organisms.

Aura-biomes are present in the water layer above coral reef benthic macro-organisms.

Science.gov (United States)

Walsh, Kevin; Haggerty, J Matthew; Doane, Michael P; Hansen, John J; Morris, Megan M; Moreira, Ana Paula B; de Oliveira, Louisi; Leomil, Luciana; Garcia, Gizele D; Thompson, Fabiano; Dinsdale, Elizabeth A

2017-01-01

As coral reef habitats decline worldwide, some reefs are transitioning from coral- to algal-dominated benthos with the exact cause for this shift remaining elusive. Increases in the abundance of microbes in the water column has been correlated with an increase in coral disease and reduction in coral cover. Here we investigated how multiple reef organisms influence microbial communities in the surrounding water column. Our study consisted of a field assessment of microbial communities above replicate patches dominated by a single macro-organism. Metagenomes were constructed from 20 L of water above distinct macro-organisms, including (1) the coral Mussismilia braziliensis , (2) fleshy macroalgae ( Stypopodium , Dictota and Canistrocarpus ), (3) turf algae, and (4) the zoanthid Palythoa caribaeorum and were compared to the water microbes collected 3 m above the reef. Microbial genera and functional potential were annotated using MG-RAST and showed that the dominant benthic macro-organisms influence the taxa and functions of microbes in the water column surrounding them, developing a specific "aura-biome". The coral aura-biome reflected the open water column, and was associated with Synechococcus and functions suggesting oligotrophic growth, while the fleshy macroalgae aura-biome was associated with Ruegeria , Pseudomonas, and microbial functions suggesting low oxygen conditions. The turf algae aura-biome was associated with Vibrio, Flavobacterium, and functions suggesting pathogenic activity, while zoanthids were associated with Alteromonas and functions suggesting a stressful environment. Because each benthic organism has a distinct aura-biome, a change in benthic cover will change the microbial community of the water, which may lead to either the stimulation or suppression of the recruitment of benthic organisms.

Measurements for modeling radionuclide transfer in the aquatic environment

International Nuclear Information System (INIS)

Kahn, B.

1976-01-01

Analytical methods for measuring radionuclides in the aquatic environment are discussed for samples of fresh water and seawater, fish and shellfish, biota such as algae, plankton, seaweed, and aquatic plants, and sediment. Consideration is given to radionuclide collection and concentration, sample preservation, radiochemical and instrumental analysis, and quality assurance. Major problems are the very low environmental levels of the radionuclides of interest, simultaneous occurrence of radionuclides in several chemical and physical forms and the numerous factors that affect radionuclide levels in and transfers among media. Some radionuclides of importance in liquid effluents from nuclear power stations are listed, and sources of radiochemical analytical methods are recommended

Toxicity of nano-TiO2 on algae and the site of reactive oxygen species production

International Nuclear Information System (INIS)

Li, Fengmin; Liang, Zhi; Zheng, Xiang; Zhao, Wei; Wu, Miao; Wang, Zhenyu

2015-01-01

Highlights: • The growth of two species of algae was inhibited under nano-TiO 2 exposure. • Oxidative stress was one of the mechanisms of toxicity of nano-TiO 2 on algae. • The site of ROS production was the electron transfer chain of chloroplast. - Abstract: Given the extensive use of nanomaterials, they may enter aquatic environments and harm the growth of algae, which are primary producers in an aquatic ecosystem. Thus, the balance of an aquatic ecosystem may be destroyed. In this study, Karenia brevis and Skeletonema costatum were exposed to nano-TiO 2 (anatase, average particle size of 5–10 nm, specific surface area of 210 ± 10 m 2 g −1 ) to assess the effects of nano-TiO 2 on algae. The findings of transmission electron microscopy-energy dispersive X-ray spectroscopy (TEM-EDX) and scanning electron microscopy (SEM) demonstrate aggregation of nano-TiO 2 in the algal suspension. Nano-TiO 2 was also found to be inside algal cells. The growth of the two species of algae was inhibited under nano-TiO 2 exposure. The 72 h EC 50 values of nano-TiO 2 to K. brevis and S. costatum were 10.69 and 7.37 mg L −1 , respectively. TEM showed that the cell membrane of K. brevis was destroyed and its organelles were almost undistinguished under nano-TiO 2 exposure. The malondialdehyde (MDA) contents of K. brevis and S. costatum significantly increased compared with those of the control (p < 0.05). Meanwhile, superoxide dismutase (SOD) and catalase activities (CAT) of K. brevis and S. costatum changed in different ways. The reactive oxygen species (ROS) levels in both species were significantly higher than those of the control (p < 0.05). The site of ROS production and accumulation in K. brevis and S. costatum under nano-TiO 2 exposure was explored with the addition of inhibitors of different electron transfer chains. This study indicated that nano-TiO 2 in algal suspensions inhibited the growth of K. brevis and S. costatum. This effect was attributed to oxidative

Contribution of arsenic species in unicellular algae to the cycling of arsenic in marine ecosystems.

Science.gov (United States)

Duncan, Elliott G; Maher, William A; Foster, Simon D

2015-01-06

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.

Modelling the role of algae in rice crop nutrition and soil organic carbon maintenance

NARCIS (Netherlands)

Gaydon, D.S.; Probert, M.E.; Buresh, R.J.; Meinke, H.B.; Timsina, J.

2012-01-01

Photosynthetic aquatic biomass (PAB – algae and other floodwater flora) is a significant source of organic carbon (C) in rice-based cropping systems. A portion of PAB is capable of fixing nitrogen (N), and is hence also a source of N for crop nutrition. To account for this phenomenon in long term

Effects of radiation on aquatic organisms

International Nuclear Information System (INIS)

Kaur, Harbhajan; Lata, Poonam; Sharma, Ankush

2012-01-01

With the onset of nuclear age, nuclear fuel cycle products, nuclear medicine techniques, disposal of radio active wastes on land or in water, fall out of testing nuclear weapons has contributed large amount of radio nuclides to the water bodies. Radio nuclides can imbalance aquatic ecosystem resulting in danger to natural life. The biological effects of radiation on aquatic life are mortality, pathophysiological, reproductive, developmental and genetic changes. A broad review of the results obtained about the aquatic organisms related to different phyla indicates that the lower or less developed or more primitive organisms are more resistant than the higher or more advanced, developed and complex organisms to ionizing radiation. The algae, protozoa are more resistant than the insects, crustaceans, molluscs and fishes. The changes in sensitivity between different stages of development have also been noted. A review of the results of exposing salmonoid gametes, eggs, fingerlings and adults to X-rays supports the concepts that radio sensitivity decreases with age. This paper presents a selective review on effects of radiation and radio nuclides on the aquatic life. It include uses and sources of radiation, effective quantity of radiation, lethal and sub lethal effect, effects on survival, growth, reproduction, behaviour, metabolism, carcinogenicity and mutagenicity. (author)

Environmental assessment of surfactant using aquatic microcosm system; Konuma no suiken seitaikei ni oyobosu kaimen kasseizai no microcosm system wo mochiita hyoka

Energy Technology Data Exchange (ETDEWEB)

Takamatsu, Y.; Matsumura, M. [University of Tsukuba, Tsukuba (Japan); Inamori, Y. [National Institute for Environmental Studies, Tsukuba (Japan); Sudo, R. [Tohoku University, Sendai (Japan). Faculty of Engineering

1995-10-10

Microcosm system was applied to assess effect of surfactants on aquatic ecosystem. Surfactants such as LAS and Soap were added to an aquatic flask-size microcosm consisting of four species of bacteria as decomposer, one species of ciliate protozoa (Cyclidium glaucoma), two rotifers (Philodina sp. and Lepadella sp.) and one aquatic oligochaete (Aeolosoma hemprichi) as predator, and a green alga (Chlorella sp.) and a filamentous blue-green alga (Tolypothrix sp.) as producer. In the system, NOEC (no observed effect concentration) of LAS was below 1.5mg{center_dot}l{sup -1}, whereas soap was below 30mg{center_dot}l{sup -1}. Microcosm test is a pertinent tool to assess the effect of surfactant on ecosystem because microcosm test makes it possible to evaluate the effect of surfactant from a viewpoint of the interaction of microorganisms, material cycle and energy flow. With these respects, microcosm test is useful environmental assessment method which can reflect aquatic ecosystem. 10 refs., 6 figs., 1 tab.

The survey of biological absorption of hexavalent chromium from aqueous solutions by Wastewater stabilization pond algae

Directory of Open Access Journals (Sweden)

Mohammad Nourisepehr

2016-06-01

Full Text Available Background: Contamination of aquatic habitats due to toxicity and accumulation of heavy metals leading to serious damage to organisms and their advance to the food chain. Chrome is one of these heavy metals for the three and six-valence oxides used in industry. Health risks such as carcinogenic hexavalent chromium have been For this reason, removal and reduction of environment is essential. Target of this study hexavalent chromium biosorption by waste stabilization pond algae is of the aquatic environment. Methods: This study was a fundamental applied; In this batch reactor, variables Was investigated pH(3,5,7,9,11, Contact time(30,60,120,180,240,300min, The concentration of hexavalent chromium(0.5,1,5mg And the concentration of algae(0.25, 0.5, 1, 3g. Liquid mixed municipal wastewater treatment stabilization pond was used for insemination. For the investigate the effects of variables pH, contact time, the concentration of hexavalent chromium values in a 250 ml Erlenmeyer flask prepared and various amounts of dried algae (0.25-0.5-1- 3 g were added to it. Then became the shakers. After mixing, the filter paper was passed. The lab temperature was centrifuged for min10-5 rpm 2700 rpm. Then it was read at a wavelength absorbed by 540 nm. . Then collected was data to Excel and SPSS software. Finally was used for hexavalent chromium adsorption isotherm model equation of Langmuir and Freundlich. Results: This study shows that PH, contact time, the concentration of hexavalent chromium and chromium concentrations of algae optimal absorption by algae concentrations, respectively, in5 mg / l, min 120, 0.5 mg / l and is 1gr. Average maximum absorption of chromium Wastewater stabilization ponds by algae 97/2%, respectively. Correlation coefficients absorption curves of these models showed that Cr (VI adsorption isotherm on wastewater stabilization pond algae follows (= R.  Conclusion: The results showed that wastewater stabilization pond algae as a

Micro -algae biomass as an alternative resource for fishmeal and fish oil in the production of fish feed

DEFF Research Database (Denmark)

Safafar, Hamed

evident that the continued exploitation of industrial fish as a resource fish feed will ultimately become both environmentally and economically unsustainable. Microalgae are at the base of the entire aquatic food chain and play a major role in the diet of aquatic animals such as fish. Microalgae’s main...... application for aquaculture are related to nutrition, being used as a sole fresh feed or an additive, e.g. source of pigment. Algae produce almost all nutritious compounds which are required for fish. The diverse biochemical composition of microalgae represents them as a promising candidate...... for the formulation of fish feed. The nutritional composition of microalgae depends on the species, environmental conditions and growth medium composition. Microalgae for use in aquaculture should be non-toxic and possess the essential nutritive constituents, in a reasonable price. Photosynthetic production of algae...

Algae in fish feed: performances and fatty acid metabolism in juvenile Atlantic Salmon.

Directory of Open Access Journals (Sweden)

Fernando Norambuena

Full Text Available 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.

Modelling the effects of pulse exposure of several PSII inhibitors on two algae.

Science.gov (United States)

Copin, Pierre-Jean; Chèvre, Nathalie

2015-10-01

Subsequent to crop application and during precipitation events, herbicides can reach surface waters in pulses of high concentrations. These pulses can exceed the Annual Average Environmental Quality Standards (AA-EQS), defined in the EU Water Framework Directive, which aims to protect the aquatic environment. A model was developed in a previous study to evaluate the effects of pulse exposure for the herbicide isoproturon on the alga Scenedesmus vacuolatus. In this study, the model was extended to other substances acting as photosystem II inhibitors and to other algae. The measured and predicted effects were equivalent when pulse exposure of atrazine and diuron were tested on S. vacuolatus. The results were consistent for isoproturon on the alga Pseudokirchneriella subcapitata. The model is thus suitable for the effect prediction of phenylureas and triazines and for the algae used: S. vacuolatus and P. subcapitata. The toxicity classification obtained from the dose-response curves (diuron>atrazine>isoproturon) was conserved for the pulse exposure scenarios modelled for S. vacuolatus. Toxicity was identical for isoproturon on the two algae when the dose-response curves were compared and also for the pulse exposure scenarios. Modelling the effects of any pulse scenario of photosystem II inhibitors on algae is therefore feasible and only requires the determination of the dose-response curves of the substance and growth rate of unexposed algae. It is crucial to detect the longest pulses when measurements of herbicide concentrations are performed in streams because the model showed that they principally affect the cell density inhibition of algae. Copyright © 2015 Elsevier Ltd. All rights reserved.

Removal of Selected Pharmaceutical and Personal Care Products by the Green Alga Nannochloris sp.

Science.gov (United States)

Bai, X.; Acharya, K.

2016-12-01

Emerging contaminants have become an increasing concern in the environment due to their ubiquitous distribution and potential adverse effects on wildlife and humans. Municipal wastewater is a major source of pharmaceutical and personal care products (PPCPs) in the Las Vegas metropolitan area. The ecotoxic impacts of PPCPs on aquatic organisms include development of antimicrobial resistance, decreases in plankton diversity, and endocrine disruption. Freshwater algae can be responsible for the uptake and transfer of the contaminants because they are a major food source for most aquatic organisms. This research applied laboratory-based incubation studies to evaluate the removal efficiency and uptake mechanisms of the selected PPCPs (trimethoprim, sulfamethoxazole, and triclosan) by the green alga Nannochloris sp. The results showed that trimethoprim and sulfamethoxazole remained in the algal culture at 100% and 68%, respectively, after 14 days of incubation, and therefore were not significantly removed from the medium. However, the antimicrobial triclosan was significantly removed from the medium. Immediately after incubation began, 74% of triclosan dissipated and 100% of triclosan was removed after 7 days of incubation. Additionally, over 42% of triclosan was found associated with the algal cells throughout the incubation. The results demonstrate that the presence of Nannochloris sp. eliminated triclosan in the aquatic system, but could not significantly remove the antibiotics trimethoprim and sulfamethoxazole. This study provided crucial information that toxicity of triclosan in aquatic organisms is a critical concern because of its high uptake by phytoplankton. The resistance of trimethoprim and sulfamethoxazole to uptake by phytoplankton may threaten water quality.

Algae in fish feed: performances and fatty acid metabolism in juvenile Atlantic Salmon.

Science.gov (United States)

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 (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.

Toxicity of nano-TiO{sub 2} on algae and the site of reactive oxygen species production

Energy Technology Data Exchange (ETDEWEB)

Li, Fengmin, E-mail: lifengmin@ouc.edu.cn [Key Laboratory of Marine Environmental Science and Ecology, Ministry of Education, College of Environmental Science and Technology, Ocean University of China, Qingdao 266100 (China); Liang, Zhi [Key Laboratory of Marine Environmental Science and Ecology, Ministry of Education, College of Environmental Science and Technology, Ocean University of China, Qingdao 266100 (China); Zheng, Xiang, E-mail: zhengxiang7825@sina.com [School of Environment and Natural Resources, Renmin University of China, Beijing 100872 (China); Zhao, Wei; Wu, Miao; Wang, Zhenyu [Key Laboratory of Marine Environmental Science and Ecology, Ministry of Education, College of Environmental Science and Technology, Ocean University of China, Qingdao 266100 (China)

2015-01-15

Highlights: • The growth of two species of algae was inhibited under nano-TiO{sub 2} exposure. • Oxidative stress was one of the mechanisms of toxicity of nano-TiO{sub 2} on algae. • The site of ROS production was the electron transfer chain of chloroplast. - Abstract: Given the extensive use of nanomaterials, they may enter aquatic environments and harm the growth of algae, which are primary producers in an aquatic ecosystem. Thus, the balance of an aquatic ecosystem may be destroyed. In this study, Karenia brevis and Skeletonema costatum were exposed to nano-TiO{sub 2} (anatase, average particle size of 5–10 nm, specific surface area of 210 ± 10 m{sup 2} g{sup −1}) to assess the effects of nano-TiO{sub 2} on algae. The findings of transmission electron microscopy-energy dispersive X-ray spectroscopy (TEM-EDX) and scanning electron microscopy (SEM) demonstrate aggregation of nano-TiO{sub 2} in the algal suspension. Nano-TiO{sub 2} was also found to be inside algal cells. The growth of the two species of algae was inhibited under nano-TiO{sub 2} exposure. The 72 h EC{sub 50} values of nano-TiO{sub 2} to K. brevis and S. costatum were 10.69 and 7.37 mg L{sup −1}, respectively. TEM showed that the cell membrane of K. brevis was destroyed and its organelles were almost undistinguished under nano-TiO{sub 2} exposure. The malondialdehyde (MDA) contents of K. brevis and S. costatum significantly increased compared with those of the control (p < 0.05). Meanwhile, superoxide dismutase (SOD) and catalase activities (CAT) of K. brevis and S. costatum changed in different ways. The reactive oxygen species (ROS) levels in both species were significantly higher than those of the control (p < 0.05). The site of ROS production and accumulation in K. brevis and S. costatum under nano-TiO{sub 2} exposure was explored with the addition of inhibitors of different electron transfer chains. This study indicated that nano-TiO{sub 2} in algal suspensions inhibited the growth

Acute toxicity of birch tar oil on aquatic organisms

Directory of Open Access Journals (Sweden)

M. HAGNER

2008-12-01

Full Text Available Birch tar oil (BTO is a by-product of processing birch wood in a pyrolysis system. Accumulating evidence suggests the suitability of BTO as a biocide or repellent in terrestrial environments for the control of weeds, insects, molluscs and rodents. Once applied as biocide, BTO may end up, either through run-off or leaching, in aquatic systems and may have adverse effects on non-target organisms. As very little is known about the toxicity of BTO to aquatic organisms, the present study investigated acute toxicity (LC50/EC50 of BTO for eight aquatic organisms. Bioassays with the Asellus aquaticus (crustacean, Lumbriculus variegatus (oligochaeta worm, Daphnia magna (crustacean, Lymnea sp. (mollusc, Lemna minor (vascular plant, Danio rerio (fish, Scenedesmus gracilis (algae, and Vibrio fischeri (bacterium were performed according to ISO, OECD or USEPA-guidelines. The results indicated that BTO was practically nontoxic to most aquatic organisms as the median effective BTO concentrations against most organisms were >150 mg L-1. In conclusion, our toxicity tests showed that aquatic organisms are to some extent, invariably sensitive to birch tar oil, but suggest that BTO does not pose a severe hazard to aquatic biota. We deduce that, unless BTOs are not applied in the immediate vicinity of water bodies, no special precaution is required.;

Chironomidae feeding habits in different habitats from a Neotropical floodplain: exploring patterns in aquatic food webs.

Science.gov (United States)

Butakka, C M M; Ragonha, F H; Train, S; Pinha, G D; Takeda, A M

2016-02-01

Ecological studies on food webs have considerably increased in recent decades, especially in aquatic communities. Because Chironomidae family are highly specious, occurring in almost all aquatic habitats is considered organisms-key to initiate studies on ecological relationships and trophic webs. We tested the hypothesis that the diversity of the morphospecies diet reflects differences on both the food items available among habitats and the preferences of larval feeding. We analyzed the gut content of the seven most abundant Chironomidae morphospecies of the different habitats from the Upper Paraná River. We categorized the food items found into algae, fungal spores, fragments of plants, algae and animal fragments and sponge spicules. We observed the algae predominance in the gut content of morphospecies from lakes. Considering the different regions from each lake, we registered the highest food abundance in the littoral regions in relation to the central regions. From the variety of feeding habits (number of item kinds), we classified Chironomus strenzkei, Tanytarsus sp.1, Procladius sp.1 as generalist morphospecies. We found a nested pattern between food items and Chironomidae morphospecies, where some items were common to all taxa (e.g., Bacillariophyceae algae, especially), while others were found in specific morphospecies (e.g., animals fragments found in Procladius sp.1). The algae represented the most percentage of gut contents of Chironomidae larvae. This was especially true for the individuals from littoral regions, which is probably due to the major densities of algae associated to macrophytes, which are abundant in these regions. Therefore, the feeding behavior of these morphospecies was generalist and not selective, depending only of the available resources.

Classification of submersed aquatic vegetation of the Venice lagoon using MIVIS airborne data

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S. Pignatti

2006-06-01

Full Text Available In July 2001 an aerial survey with MIVIS (Multispectral Infrared and Visible Spectrometer hyperspectral sensor and an in situ survey campaign were performed on Venice lagoon to map benthic macro-algae and sea phanerogams distribution. On MIVIS VIS spectral range images, training areas for benthic macro-algae and sea phanerogams have been selected by using sea truth data collected by CNR-ISMAR from in situ campaign and periodic area surveys used in the lagoon by the local authorities. The derived spectral signature has been used to classify the area in order to produce the maps of the pure and mixture submersed vegetation population. The algorithm applied to the data is based on the Subpixel Spectral Analytical Process (SSAP method. The method assumes that the spectrum of a single pixel is composed of a fraction of the material of interest while the remainder of the observed spectra contains background materials. In terms of recognition processes the produced maps present a very good agreement with the sea truth data even though the fraction material expressed in the maps does not represent a quantitative estimation of the material of interest.

Late cretaceous aquatic plant world in Patagonia, Argentina.

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N Rubén Cúneo

Full Text Available In this contribution, we describe latest Cretaceous aquatic plant communities from the La Colonia Formation, Patagonia, Argentina, based on their taxonomic components and paleoecological attributes. The La Colonia Formation is a geological unit deposited during a Maastrichtian-Danian transgressive episode of the South Atlantic Ocean. This event resulted in the deposition of a series of fine-grained sediments associated with lagoon systems occurring along irregular coastal plains in northern Patagonia. These deposits preserved a diverse biota, including aquatic and terrestrial plants and animals. The aquatic macrophytes can be broadly divided into two groups: free-floating and rooted, the latter with emergent or floating leaves. Free-floating macrophytes include ferns in Salviniaceae (Azolla and Paleoazolla and a monocot (Araceae. Floating microphytes include green algae (Botryoccocus, Pediastrum and Zygnemataceae. Among the rooted components, marsileaceous water ferns (including Regnellidium and an extinct form and the eudicot angiosperm Nelumbo (Nelumbonaceae are the dominant groups. Terrestrial plants occurring in the vegetation surrounding the lagoons include monocots (palms and Typhaceae, ferns with affinities to Dicksoniaceae, conifers, and dicots. A reconstruction of the aquatic plant paleocommuniy is provided based on the distribution of the fossils along a freshwater horizon within the La Colonia Formation. This contribution constitutes the first reconstruction of a Cretaceous aquatic habitat for southern South America.

Late Cretaceous Aquatic Plant World in Patagonia, Argentina

Science.gov (United States)

Cúneo, N. Rubén; Gandolfo, María A.; Zamaloa, María C.; Hermsen, Elizabeth

2014-01-01

In this contribution, we describe latest Cretaceous aquatic plant communities from the La Colonia Formation, Patagonia, Argentina, based on their taxonomic components and paleoecological attributes. The La Colonia Formation is a geological unit deposited during a Maastrichtian-Danian transgressive episode of the South Atlantic Ocean. This event resulted in the deposition of a series of fine-grained sediments associated with lagoon systems occurring along irregular coastal plains in northern Patagonia. These deposits preserved a diverse biota, including aquatic and terrestrial plants and animals. The aquatic macrophytes can be broadly divided into two groups: free-floating and rooted, the latter with emergent or floating leaves. Free-floating macrophytes include ferns in Salviniaceae (Azolla and Paleoazolla) and a monocot (Araceae). Floating microphytes include green algae (Botryoccocus, Pediastrum and Zygnemataceae). Among the rooted components, marsileaceous water ferns (including Regnellidium and an extinct form) and the eudicot angiosperm Nelumbo (Nelumbonaceae) are the dominant groups. Terrestrial plants occurring in the vegetation surrounding the lagoons include monocots (palms and Typhaceae), ferns with affinities to Dicksoniaceae, conifers, and dicots. A reconstruction of the aquatic plant paleocommuniy is provided based on the distribution of the fossils along a freshwater horizon within the La Colonia Formation. This contribution constitutes the first reconstruction of a Cretaceous aquatic habitat for southern South America. PMID:25148081

Sustainable Use Of Macro-Algae For Biogas Production In Latvian Conditions: A Preliminary Study Through An Integrated Mca And Lca Approach

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Pastare Laura

2014-12-01

Full Text Available The study focuses on sustainability evaluation of an algae-based energy system in Latvia with a holistic and integrated approach of multi-criteria analysis combined with life cycle assessment (including a practical side - biogas yield experiments of locally available algae.

Are Aquatic Viruses a Biological Archive of Genetic Information from Universe?

Science.gov (United States)

Toparceanu, F.; Negoita, Gh. T.; Nita, I. I.; Sava, D.

2009-04-01

After 1990, when the viruses were admited as the most abundant lifeforms from aquatic environments, it became obvious that viral lysis had an essential role on release and recycling of nutrients. Studies on cellular cultures and modeling suggest that this is an important quantitative process. The viruses from oceans represent the widest source of genetic diversity on the Earth, uncharacterized yet. The ancient lifeforms records stretching back a million years are locked in ice caps. The trend of glaciers melting as effect of actual climate change will promote the release of ancient viruses from ice caps. The increasing of the freshwater layer led to the replace of some algae species by others. Law-Racovitza Station (69o23'S 76o23'E) from East Antarctica (Larsemann Hills Oasis) offers opportunities to study the Antarctic marine ecosystem, as well as archaic aquatic ecosystems from this area ( 150 lakes and waterways resulted from ice and snow melting during the austral summer). According to Law-Racovitza Station Scientific Program, we are performing studies regarding the effect of climate changes on virus-algae host relationship in these aquatic ecosystems. Phycodnaviruses, that infect the eukaryote algae, are comprised of ancient genes and they are considered a "peek" of genetic diversity useful in biological studies and exobiology regarding the evolution of genetic sequencing. The latest discoveries of the giant aquatic viruses open the unexpected perspectives for understanding the role of viral infection in global ecosystem; beyond the old concept which considered that the viruses were only etiological agents of human, animals and plants illnesses. The aquatic viruses which infect microalgae contain similar genes of other viruses, bacteria, arhebacteria and eukaryotes, all of them being on the same genome. Which is the signification of enormous abundance of viruses and excessive diversity of genetic information encoded by viruses? There is the possibility that

Effects of Harmful Algae on the Physiology of Fishes

DEFF Research Database (Denmark)

Svendsen, Morten Bo Søndergaard

Blooms of harmful planktonic algae causing adverse effects in aquatic environments are a global problem, causing both human morbidity and killing aquatic lifeforms worldwide. Focusing on fish kills, it is largely unknown what mechanisms of the fish’s physiology are affected during exposure...... is deemed unlikely on basis of rainbow trout (Onchorhyncus mykiss) not recovering. The specific toxicity of Pseudochattonella spp. is unknown, but by studying the effects of Pseudochattonella spp. on fish during a natural bloom occurring at a trout farm an adverse outcome could be created. The adverse...... Alexandrium monilatum has been studied intensively the effects of Alexandrium monilatum on fish is largely unknown. In the Chesapeake Bay, Eastern U.S.A., fishes are further challenged in late summer by an oxygen squeeze from deep part of the water column, limiting their utilizable habitat to mid...

USAGE OF ALGAE SPECIES CHAETOMORPHA GRACILIS AND CH. AEREA FOR DEPURATION PROCESS OF THE RESIDUAL WATERS

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SALARU VICTOR

2008-11-01

Full Text Available Rapid increase of the population on the globe scale imposes maximum exploration of the natural resources and first of all of the aquatic resources. As a result are obtained an enormous quantity of residual waters which pollute the waters from rivers, lakes, freatic and underground waters. Elaboration of the depuration methods for residual waters the quantity of which grows continuously, is one of the most up to dated issue of the world. The physical-chemical depuration methods of the residual waters are very expensive and lack the efficiency we would like to have. The most efficient method proved to be the biological method using some species of algae and superior aquatic plants. In our experiences we have involved filamentous green algae Chaetomorpha gracilis and Ch. aerea for depuration of the sewerage water from town Cimishlia. The concentration of the mineral nitrogen compounds in the residual water is around 92,5 mg/l, and of the phosphates 10,1 mg/l. There were used the following concentration of the sewerage water: 10%, 25% and 50%. The most intense development of algae Chaetomorpha aerea was observed in the variant with 10% of residual water, in which the total concentration of the nitrogen was 10,24 mg/l, and of the phosphates 1,05 mg/l. For this variant the depuration water level was about 56,9%. For the case with Chaetomorpha gracilis, the depuration level for the same concentration of the residual water constituted 55,9 %. Increase of the concentration of the polluted water inhibits development of the algae reducing to the minimum their capacity to assimilate the nitrogen and the phosphor. In the solutions with 50 % of residual waters, the algae didn't die, but at the same time they didn't develop. From this results that both algae may be used in the phytoamelioration of the residual waters being diluted at 10% with purified water.

Identification of cypermethrin induced protein changes in green algae by iTRAQ quantitative proteomics.

Science.gov (United States)

Gao, Yan; Lim, Teck Kwang; Lin, Qingsong; Li, Sam Fong Yau

2016-04-29

Cypermethrin (CYP) is one of the most widely used pesticides in large scale for agricultural and domestic purpose and the residue often seriously affects aquatic system. Environmental pollutant-induced protein changes in organisms could be detected by proteomics, leading to discovery of potential biomarkers and understanding of mode of action. While proteomics investigations of CYP stress in some animal models have been well studied, few reports about the effects of exposure to CYP on algae proteome were published. To determine CYP effect in algae, the impact of various dosages (0.001μg/L, 0.01μg/L and 1μg/L) of CYP on green algae Chlorella vulgaris for 24h and 96h was investigated by using iTRAQ quantitative proteomics technique. A total of 162 and 198 proteins were significantly altered after CYP exposure for 24h and 96h, respectively. Overview of iTRAQ results indicated that the influence of CYP on algae protein might be dosage-dependent. Functional analysis of differentially expressed proteins showed that CYP could induce protein alterations related to photosynthesis, stress responses and carbohydrate metabolism. This study provides a comprehensive view of complex mode of action of algae under CYP stress and highlights several potential biomarkers for further investigation of pesticide-exposed plant and algae. Copyright © 2016 Elsevier B.V. All rights reserved.

Diatomite Ores: Origin, Characterization and Applications

OpenAIRE

, S.S. Ibrahim

2016-01-01

Diatomite is a sedimentary silica mineral that composed of the fossilized skeletal remains of the microscopic single-celled aquatic plants called diatoms. Over 10,000 species of these microscopic algae have been recognized, each with its own distinct morphology. Accordingly, diatomite is multifaceted and varies from microto macro-meter in size. Diatomite has many important industrial applications due to its unique properties. Its chemical constitution is approximately 85% insoluble silica; ac...

Effects of acute gamma-irradiation on the aquatic microbial microcosm in comparison with chemicals

Energy Technology Data Exchange (ETDEWEB)

Fuma, Shoichi, E-mail: fuma@nirs.go.j [Environmental Radiation Effects Research Group, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Ishii, Nobuyoshi; Takeda, Hiroshi; Miyamoto, Kiriko; Yanagisawa, Kei [Environmental Radiation Effects Research Group, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Doi, Kazutaka; Kawaguchi, Isao [Regulatory Sciences Research Group, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Tanaka, Nobuyuki [Environmental Chemistry Division, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506 (Japan); Inamori, Yuhei [Faculty of Symbiotic Systems Science, Fukushima University, 1 Kanayagawa, Fukushima 960-1296 (Japan); Polikarpov, Gennady G. [The A.O. Kovalevsky Institute of Biology of Southern Seas, Sevastopol 99011 (Ukraine)

2009-12-15

Effects of acute gamma-irradiation were investigated in the aquatic microcosm consisting of green algae (Chlorella sp. and Scenedesmus sp.) and a blue-green alga (Tolypothrix sp.) as producers; an oligochaete (Aeolosoma hemprichi), rotifers (Lecane sp. and Philodina sp.) and a ciliate protozoan (Cyclidium glaucoma) as consumers; and more than four species of bacteria as decomposers. At 100 Gy, populations were not affected in any taxa. At 500-5000 Gy, one or three taxa died out and populations of two or three taxa decreased over time, while that of Tolypothrix sp. increased. This Tolypothrix sp. increase was likely an indirect effect due to interspecies interactions. The principal response curve analysis revealed that the main trend of the effects was a dose-dependent population decrease. For a better understanding of radiation risks in aquatic microbial communities, effect doses of gamma-rays compared with copper, herbicides and detergents were evaluated using the radiochemoecological conceptual model and the effect index for microcosm.

Effects of acute γ-irradiation on the aquatic microbial microcosm in comparison with chemicals

International Nuclear Information System (INIS)

Fuma, Shoichi; Ishii, Nobuyoshi; Takeda, Hiroshi; Miyamoto, Kiriko; Yanagisawa, Kei; Doi, Kazutaka; Kawaguchi, Isao; Tanaka, Nobuyuki; Inamori, Yuhei; Polikarpov, Gennady G.

2009-01-01

Effects of acute γ-irradiation were investigated in the aquatic microcosm consisting of green algae (Chlorella sp. and Scenedesmus sp.) and a blue-green alga (Tolypothrix sp.) as producers; an oligochaete (Aeolosoma hemprichi), rotifers (Lecane sp. and Philodina sp.) and a ciliate protozoan (Cyclidium glaucoma) as consumers; and more than four species of bacteria as decomposers. At 100 Gy, populations were not affected in any taxa. At 500-5000 Gy, one or three taxa died out and populations of two or three taxa decreased over time, while that of Tolypothrix sp. increased. This Tolypothrix sp. increase was likely an indirect effect due to interspecies interactions. The principal response curve analysis revealed that the main trend of the effects was a dose-dependent population decrease. For a better understanding of radiation risks in aquatic microbial communities, effect doses of γ-rays compared with copper, herbicides and detergents were evaluated using the radiochemoecological conceptual model and the effect index for microcosm.

Impact of heavy metals on macro-invertebrate fauna of the thaddo stream

International Nuclear Information System (INIS)

Nazneen, S.; Begum, F.; Sharmeen, R.; Ahmed, Z.

2003-01-01

Impact of some heavy metals like zinc, lead, copper, chromium and cadmium were studied at four spots on the macro-invertebrate fauna of the Thaddo stream, a tributary of Malir River. This was in correlation with an earlier study on the physico-chemical aspects of water which showed a severe pollution in this stream. Present data for the qualitative and quantitative analyses of macro-invertebrates and the ranges of heavy metals (Zn 0.5-3.5, Pb 0.90-1.42, Cu 0.35-0.93, Cr 0.0-0.08 and Cd 0.003-0.01 ppm) in the water samples also indicate high level of pollution in the stream. Macro-invertebrate fauna comprises only of aquatic insects which include larvae of Chironomus spp., adults of the Notonectus sp., and nymphs of Gomphus sp. (dragon fly) belonging to the order Diptera , Hemiptera and Odonata, respectively. Quantitatively Notonectus sp. predominated and followed by Chironomus larvae. The maximum concentrations of all heavy metals were recorded at spot 3. A general trend of increase was observed from up stream to down stream regions particularly in the level of zinc. However, a reverse trend was observed in the abundance of macro-invertebrates with a great reduction at spot 4. The statistical analysis of the data generally indicates a negative correlation between the values of the studied heavy metals and the abundance of macro-invertebrates throughout this study. (author)

Effects of N and P enrichment on competition between phytoplankton and benthic algae in shallow lakes: a mesocosm study.

Science.gov (United States)

Zhang, Xiufeng; Mei, Xueying; Gulati, Ramesh D; Liu, Zhengwen

2015-03-01

Competition for resources between coexisting phytoplankton and benthic algae, but with different habitats and roles in functioning of lake ecosystems, profoundly affects dynamics of shallow lakes in the process of eutrophication. An experiment was conducted to test the hypothesis that combined enrichment with nitrogen (N) and phosphorus (P) would be a greater benefit to phytoplankton than benthic algae. The growth of phytoplankton and benthic algae was measured as chlorophyll a (Chl a) in 12 shallow aquatic mesocosms supplemented with N, P, or both. We found that enrichment with N enhanced growth of benthic algae, but not phytoplankton. P enrichment had a negative effect on benthic algal growth, and no effect on the growth of phytoplankton. N+P enrichment had a negative effect on benthic algae, but enhanced the growth of phytoplankton, thus reducing the proportion of benthic algae contributing to the combined biomass of these two groups of primary producers. Thus, combined N+P enrichment is more favorable to phytoplankton in competition with benthic algae than enrichment with either N or P alone. Our study indicates that combined enrichment with N+P promotes the dominance of phytoplankton over benthic algae, with consequences for the trophic dynamics of shallow lake ecosystems.

Instrumental neutron activation analysis study of elemental concentrations in some species of marine algae form different regions of Libyan coast

International Nuclear Information System (INIS)

Abugassa, I. O.; Al-Dalem, B. S.

2012-12-01

Algae are an ideal marine species to study responses to different environmental factors free complication inherent in research with more complex higher plants. One of the advantages of environmental study using algae is the possibility to achieve and observe many generations during relative short time period. Algae materials have been used as ecological and environmental indicators to monitor and control in many fields of study such as freshwater and marine ecosystems, soil fertility, industrial applications, etc. It also has been shown that algae assemblages could be used as indicators of clean or polluted water. Previous studies proved high sensitivity of the most algae towards changing of environmental conditions, especially as consequences of water pollution. Algae respond rapidly and predictably to a wide range of pollutants and potentially use full early warning signals of deteriorating conditions and possible causes. Because of their nutritional needs and their position at the base of aquatic food web, algae indicators provide relativity unique information concerning ecosystem conditions compared with commonly used animal indicators. In most cases ecologically relevant signals of ecosystem changes are being provided that can be used to distinguish acceptable from unacceptable environmental conditions. Algae indicators are also a cost-effective monitoring tool as well. (Author)

Prediction of climate impacts on pesticide leaching to the aquatic environments

Energy Technology Data Exchange (ETDEWEB)

Henriksen, Hans Joergen; Rosenbom, A.; van der Keur, P.; Kjaer, J.; Sonnenborg, T. [GEUS Danmark, Copenhagen (Denmark); Olesen, J.E. [Aarhus Univ., Tjele (Denmark); Nistrup Joergensen, L. [Aarhus Unv., Slagelse (Denmark); Boessing Christensen, O. [Danmarks Meteorologiske Institut (DMI), Copenhagen (Denmark)

2013-10-01

The report evaluates direct (precipitation, actual evapotranspiration and temperature) and indirect (crop rotations, crop management, and pesticide use) climatic change effects on pesticide-leaching to groundwater and the aquatic environment by use of MACRO and MIKE SHE model. The analysis is based on five model pesticides: low-dose herbicides, ordinary herbicides, strongly sorbing herbicides, fungicides and insecticides, and selected farm types (arable and dairy) for the variable saturated sandy soil (Jyndevad) and loamy soil (Faardrup). The evaluation has the aim at describing the implications of future climatic factors on pesticide leaching to groundwater as realistic as possible, based on realistic doses and parameters from MACRO setups from the Danish Pesticide Leaching Assessment Programme. (Author)

Aquatic plant surface as a niche for methanotrophs

Directory of Open Access Journals (Sweden)

Naoko eYoshida

2014-02-01

Full Text Available This study investigated the potential local CH4 sink in various plant parts as a boundary environment of CH4 emission and consumption. By comparing CH4 consumption activities in cultures inoculated with parts from 39 plant species, we observed significantly higher consumption of CH4 associated with aquatic plants than other emergent plant parts such as woody plant leaves, macrophytic marine algae, and sea grass. In situ activity of CH4 consumption by methanotrophs associated with different species of aquatic plants was in the range of 3.7 – 37 μmol⋅h-1⋅g-1 dry weight, which was ca 5.7-370 fold higher than epiphytic CH4 consumption in submerged parts of emergent plants. The qPCR-estimated copy numbers of the particulate methane monooxygenase-encoding gene pmoA were variable among the aquatic plants and ranged in the order of 105 to 107 copies⋅g-1 dry weight, which correlated with the observed CH4 consumption activities. Phylogenetic identification of methanotrophs on aquatic plants based on the pmoA sequence analysis revealed a predominance of diverse gammaproteobacterial type-I methanotrophs, including a phylotype of a possible plant-associated methanotroph with the closest identity (86-89% to Methylocaldum gracile.

Biochemical responses of filamentous algae in different aquatic ecosystems in South East Turkey and associated water quality parameters.

Science.gov (United States)

Çelekli, Abuzer; Arslanargun, Hamdullah; Soysal, Çiğdem; Gültekin, Emine; Bozkurt, Hüseyin

2016-11-01

To the best of our knowledge, any study about biochemical response of filamentous algae in the complex freshwater ecosystems has not been found in the literature. This study was designed to explore biochemical response of filamentous algae in different water bodies from May 2013 to October 2014, using multivariate approach in the South East of Turkey. Environmental variables were measured in situ: water temperature, oxygen concentration, saturation, conductivity, salinity, pH, redox potential, and total dissolved solid. Chemical variables of aqueous samples and biochemical compounds of filamentous algae were also measured. It was found that geographic position and anthropogenic activities had strong effect on physico-chemical variables of water bodies. Variation in environmental conditions caused change in algal biomass composition due to the different response of filamentous species, also indicated by FTIR analysis. Biochemical responses not only changed from species to species, but also varied for the same species at different sampling time and sampling stations. Multivariate analyses showed that heavy metals, nutrients, and water hardness were found as the important variables governing the temporal and spatial succession and biochemical compounds. Nutrients, especially nitrate, could stimulate pigment and total protein production, whereas high metal content had adverse effects. Amount of malondialdehyde (MDA), H2O2, total thiol groups, total phenolic compounds, proline, total carbohydrate, and metal bioaccumulation by filamentous algae could be closely related with heavy metals in the ecosystems. Significant increase in MDA, H2O2, total thiol group, total phenolic compounds, and proline productions by filamentous algae and chlorosis phenomenon seemed to be an important strategy for alleviating environmental factors-induced oxidative stress as biomarkers. Copyright © 2016 Elsevier Inc. All rights reserved.

Simulated bioavailability of phosphorus from aquatic macrophytes and hytoplankton by aqueous suspension and incubation with alkaline phosphatase

Science.gov (United States)

Bioavailability of phosphorus (P) in aquatic macrophytes and algae on lake eutrophication was studied by evaluation their P forms and quantities in their water suspensions and impact by alkaline phosphatase hydrolysis. using solution 31P-nuclear magnetic resonance (NMR). The laboratory suspension an...

Effects of dietary esfenvalerate exposures on three aquatic insect species representing different functional feeding groups.

Science.gov (United States)

Palmquist, Katherine R; Jenkins, Jeffrey J; Jepson, Paul C

2008-08-01

Given the chemical properties of synthetic pyrethroids, it is probable that compounds, including esfenvalerate, that enter surface waters may become incorporated into aquatic insect food sources. We examined the effect of dietary esfenvalerate uptake in aquatic insects representing different functional feeding groups. We used three field-collected aquatic insect species: A grazing scraper, Cinygmula reticulata McDunnough (Ephemeroptera: Heptageniidae); an omnivorous filter feeder, Brachycentrus americanus Banks (Trichoptera: Brachycentridae); and a predator, Hesperoperla pacifica Banks (Plecoptera: Perlidae). Laboratory-cultured algae were preexposed for 24 h to esfenvalerate concentrations of 0, 0.025, 0.05, and 0.1 microg/L and provided to two C. reticulata age classes (small and final-instar nymphs). Reduction in small nymph growth was observed following three weeks of feeding on algae exposed to 0.05 and 0.1 microg/L of esfenvalerate, and the highest dietary exposure reduced egg production in final-instar nymphs. The diet for B. americanus and H. pacifica consisted of dead third-instar Chironomus tentans larvae preexposed for 24 h to esfenvalerate concentrations ranging between 0.1 and 1.0 microg/L. Consumption of larvae exposed to 0.5 to 1.0 microg/L of esfenvalerate caused case abandonment and mortality in B. americanus caddisfly larvae. Although H. pacifica nymphs readily consumed esfenvalerate-exposed larvae, no adverse effects were observed during the present study. Furthermore, no evidence of esfenvalerate-induced feeding deterrence was found in any of the species tested, suggesting that aquatic insects may not be able to distinguish between pyrethroid-contaminated and uncontaminated food sources. These findings indicate that feeding deterrence is not a factor in regulating aquatic insect dietary exposures to synthetic pyrethroids.

A Multi-Platform Optical Sensor for In Vivo and In Vitro Algae Classification.

Science.gov (United States)

Ng, Chee-Loon; Chen, Qing-Qing; Chua, Jia-Jing; Hemond, Harold F

2017-04-20

Differentiation among major algal groups is important for the ecological and biogeochemical characterization of water bodies, and for practical management of water resources. It helps to discern the taxonomic groups that are beneficial to aquatic life from the organisms causing harmful algal blooms. An LED-induced fluorescence (LEDIF) instrument capable of fluorescence, absorbance, and scattering measurements; is used for in vivo and in vitro identification and quantification of four algal groups found in freshwater and marine environments. Aqueous solutions of individual and mixed dissolved biological pigments relevant to different algal groups were measured to demonstrate the LEDIF's capabilities in measuring extracted pigments. Different genera of algae were cultivated and the cell counts of the samples were quantified with a hemacytometer and/or cellometer. Dry weight of different algae cells was also measured to determine the cell counts-to-dry weight correlations. Finally, in vivo measurements of different genus of algae at different cell concentrations and mixed algal group in the presence of humic acid were performed with the LEDIF. A field sample from a local reservoir was measured with the LEDIF and the results were verified using hemacytometer, cellometer, and microscope. The results demonstrated the LEDIF's capabilities in classifying and quantifying different groups of live algae.

A Multi-Platform Optical Sensor for In Vivo and In Vitro Algae Classification

Directory of Open Access Journals (Sweden)

Chee-Loon Ng

2017-04-01

Full Text Available Differentiation among major algal groups is important for the ecological and biogeochemical characterization of water bodies, and for practical management of water resources. It helps to discern the taxonomic groups that are beneficial to aquatic life from the organisms causing harmful algal blooms. An LED-induced fluorescence (LEDIF instrument capable of fluorescence, absorbance, and scattering measurements; is used for in vivo and in vitro identification and quantification of four algal groups found in freshwater and marine environments. Aqueous solutions of individual and mixed dissolved biological pigments relevant to different algal groups were measured to demonstrate the LEDIF’s capabilities in measuring extracted pigments. Different genera of algae were cultivated and the cell counts of the samples were quantified with a hemacytometer and/or cellometer. Dry weight of different algae cells was also measured to determine the cell counts-to-dry weight correlations. Finally, in vivo measurements of different genus of algae at different cell concentrations and mixed algal group in the presence of humic acid were performed with the LEDIF. A field sample from a local reservoir was measured with the LEDIF and the results were verified using hemacytometer, cellometer, and microscope. The results demonstrated the LEDIF’s capabilities in classifying and quantifying different groups of live algae.

Photosystem I shows a higher tolerance to sorbitol-induced osmotic stress than photosystem II in the intertidal macro-algae Ulva prolifera (Chlorophyta).

Science.gov (United States)

Gao, Shan; Zheng, Zhenbing; Gu, Wenhui; Xie, Xiujun; Huan, Li; Pan, Guanghua; Wang, Guangce

2014-10-01

The photosynthetic performance of the desiccation-tolerant, intertidal macro-algae Ulva prolifera was significantly affected by sorbitol-induced osmotic stress. Our results showed that photosynthetic activity decreased significantly with increases in sorbitol concentration. Although the partial activity of both photosystem I (PS I) and photosystem II (PS II) was able to recover after 30 min of rehydration, the activity of PS II decreased more rapidly than PS I. At 4 M sorbitol concentration, the activity of PS II was almost 0 while that of PS I was still at about one third of normal levels. Following prolonged treatment with 1 and 2 M sorbitol, the activity of PS I and PS II decreased slowly, suggesting that the effects of moderate concentrations of sorbitol on PS I and PS II were gradual. Interestingly, an increase in non-photochemical quenching occurred under these conditions in response to moderate osmotic stress, whereas it declined significantly under severe osmotic stress. These results suggest that photoprotection in U. prolifera could also be induced by moderate osmotic stress. In addition, the oxidation of PS I was significantly affected by osmotic stress. P700(+) in the thalli treated with high concentrations of sorbitol could still be reduced, as PS II was inhibited by 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), but it could not be fully oxidized. This observation may be caused by the higher quantum yield of non-photochemical energy dissipation in PS I due to acceptor-side limitation (Y(NA)) during rehydration in seawater containing DCMU. © 2014 Scandinavian Plant Physiology Society.

Predicting the risk of toxic blooms of golden alga from cell abundance and environmental covariates

Science.gov (United States)

Patino, Reynaldo; VanLandeghem, Matthew M.; Denny, Shawn

2016-01-01

Golden alga (Prymnesium parvum) is a toxic haptophyte that has caused considerable ecological damage to marine and inland aquatic ecosystems worldwide. Studies focused primarily on laboratory cultures have indicated that toxicity is poorly correlated with the abundance of golden alga cells. This relationship, however, has not been rigorously evaluated in the field where environmental conditions are much different. The ability to predict toxicity using readily measured environmental variables and golden alga abundance would allow managers rapid assessments of ichthyotoxicity potential without laboratory bioassay confirmation, which requires additional resources to accomplish. To assess the potential utility of these relationships, several a priori models relating lethal levels of golden alga ichthyotoxicity to golden alga abundance and environmental covariates were constructed. Model parameters were estimated using archived data from four river basins in Texas and New Mexico (Colorado, Brazos, Red, Pecos). Model predictive ability was quantified using cross-validation, sensitivity, and specificity, and the relative ranking of environmental covariate models was determined by Akaike Information Criterion values and Akaike weights. Overall, abundance was a generally good predictor of ichthyotoxicity as cross validation of golden alga abundance-only models ranged from ∼ 80% to ∼ 90% (leave-one-out cross-validation). Environmental covariates improved predictions, especially the ability to predict lethally toxic events (i.e., increased sensitivity), and top-ranked environmental covariate models differed among the four basins. These associations may be useful for monitoring as well as understanding the abiotic factors that influence toxicity during blooms.

Interactions between arsenic species and marine algae

Energy Technology Data Exchange (ETDEWEB)

Sanders, J.G.

1978-01-01

The arsenic concentration and speciation of marine algae varies widely, from 0.4 to 23 ng.mg/sup -1/, with significant differences in both total arsenic content and arsenic speciation occurring between algal classes. The Phaeophyceae contain more arsenic than other algal classes, and a greater proportion of the arsenic is organic. The concentration of inorganic arsenic is fairly constant in macro-algae, and may indicate a maximum level, with the excess being reduced and methylated. Phytoplankton take up As(V) readily, and incorporate a small percentage of it into the cell. The majority of the As(V) is reduced, methylated, and released to the surrounding media. The arsenic speciation in phytoplankton and Valonia also changes when As(V) is added to cultures. Arsenate and phosphate compete for uptake by algal cells. Arsenate inhibits primary production at concentrations as low as 5 ..mu..g.1/sup -1/ when the phosphate concentration is low. The inhibition is competitive. A phosphate enrichment of > 0.3 ..mu..M alleviates this inhibition; however, the As(V) stress causes an increase in the cell's phosphorus requirement. Arsenite is also toxic to phytoplankton at similar concentrations. Methylated arsenic species did not affect cell productivity, even at concentrations of 25 ..mu..g.1/sup -1/. Thus, the methylation of As(V) by the cell produces a stable, non-reactive compound which is nontoxic. The uptake and subsequent reduction and methylation of As(V) is a significant factor in determining the arsenic biogeochemistry of productive systems, and also the effect that the arsenic may have on algal productivity. Therefore, the role of marine algae in determining the arsenic speciation of marine systems cannot be ignored. (ERB)

The Study of Algae

Science.gov (United States)

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)

Direct and indirect effects of glaciers on aquatic biodiversity in high Andean peatlands

DEFF Research Database (Denmark)

Quenta, Estefania; Molina-Rodriguez, Jorge; Gonzales, Karina

2016-01-01

to which there is high α-diversity at intermediate levels of glacial influence due to the high degree of environmental heterogeneity caused by glacier water. This α-diversity pattern generates high levels of between-site aquatic community variation (high β diversity) and increases regional diversity (γ......The rapid melting of glacier cover is one of the most obvious impacts of climate change on alpine ecosystems and biodiversity. Our understanding of the impact of a decrease in glacier runoff on aquatic biodiversity is currently based on the 'glacier-heterogeneity-diversity' paradigm, according......-diversity). There is a rich conceptual background in favor of this paradigm, but empirical data supporting it are scarce. We investigated this paradigm by analyzing the different diversity patterns (α, β and γ-diversity) of four aquatic groups (zooplankton, macroinvertebrates, algae and macrophytes) living in high...

Modelling the effects of PSII inhibitor pulse exposure on two algae in co-culture.

Science.gov (United States)

Copin, Pierre-Jean; Chèvre, Nathalie

2018-03-01

A weakness of standard testing procedures is that they do not consider interactions between organisms, and they focus only on single species. Furthermore, these procedures do not take into account pulse exposure. However, pulse exposure is of particular importance because in streams, after crop application and during and after precipitation, herbicide concentrations fluctuate widely and can exceed the Annual Average Environmental Quality Standards (AA-EQS), which aim to protect the aquatic environment. The sensitivity of the algae Scenedesmus vacuolatus and Pseudokirchneriella subcapitata in a co-culture exposed to pulses is thus analysed in this study. As a first step, the growths of the algae in co-culture are investigated. For initial cell densities fixed, respectively, to 100,000 and 50,000 cells/mL, the growth of each alga is exponential over at least 48 h. S. vacuolatus seems to influence the growth of P. subcapitata negatively. Allelopathy is a possible explanation for this growth inhibition. The toxicity of the herbicide isoproturon is later tested on the algae S. vacuolatus and P. subcapitata cultured alone and in the co-culture. Despite the supplementary stress on the algae in the co-culture competing for nutrients, the toxicity of the herbicide is lower for the two algae when they are in the co-culture than when they are in separated culture. A model is adapted and used to predict the cell-density inhibition on the alga S. vacuolatus in the co-culture with the alga P. subcapitata exposed to a pulse concentration of isoproturon. Four laboratory experiments are performed to validate the model. The comparison between the laboratory and the modelled effects shows good agreement. The differences can be considered minor most of time. For future studies, it is important to ensure that the cell count is precise, as it is used to determine the parameters of the model. The differences can be also induced by the fact that the cell number of the alga P

Algae biodiesel - a feasibility report

Science.gov (United States)

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

Algae biodiesel - a feasibility report

Directory of Open Access Journals (Sweden)

Gao Yihe

2012-04-01

Full Text Available Abstract 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.

Macro-Invertebrate Decline in Surface Water Polluted with Imidacloprid

Science.gov (United States)

Van Dijk, Tessa C.; Van Staalduinen, Marja A.; Van der Sluijs, Jeroen P.

2013-01-01

Imidacloprid is one of the most widely used insecticides in the world. Its concentration in surface water exceeds the water quality norms in many parts of the Netherlands. Several studies have demonstrated harmful effects of this neonicotinoid to a wide range of non-target species. Therefore we expected that surface water pollution with imidacloprid would negatively impact aquatic ecosystems. Availability of extensive monitoring data on the abundance of aquatic macro-invertebrate species, and on imidacloprid concentrations in surface water in the Netherlands enabled us to test this hypothesis. Our regression analysis showed a significant negative relationship (Pmacro-invertebrate abundance and imidacloprid concentration for all species pooled. A significant negative relationship was also found for the orders Amphipoda, Basommatophora, Diptera, Ephemeroptera and Isopoda, and for several species separately. The order Odonata had a negative relationship very close to the significance threshold of 0.05 (P = 0.051). However, in accordance with previous research, a positive relationship was found for the order Actinedida. We used the monitoring field data to test whether the existing three water quality norms for imidacloprid in the Netherlands are protective in real conditions. Our data show that macrofauna abundance drops sharply between 13 and 67 ng l−1. For aquatic ecosystem protection, two of the norms are not protective at all while the strictest norm of 13 ng l−1 (MTR) seems somewhat protective. In addition to the existing experimental evidence on the negative effects of imidacloprid on invertebrate life, our study, based on data from large-scale field monitoring during multiple years, shows that serious concern about the far-reaching consequences of the abundant use of imidacloprid for aquatic ecosystems is justified. PMID:23650513

Removal of bisphenol A by the freshwater green alga Monoraphidium braunii and the role of natural organic matter

International Nuclear Information System (INIS)

Gattullo, C. Eliana; Bährs, Hanno; Steinberg, Christian E.W.; Loffredo, Elisabetta

2012-01-01

Phytoremediation of waters by aquatic organisms such as algae has been recently explored for the removal of organic pollutants possessing endocrine disrupting capacity. Monoraphidium braunii, a green alga known for rapid growth and good tolerance to different natural organic matter (NOM) qualities, was tested in this study for the ability to tolerate and remove the endocrine disruptor bisphenol A at concentrations of 2, 4 and 10 mg L −1 , either in NOM-free or NOM-containing media. NOM at concentrations of 2, 5 and 20 mg L −1 of DOC, was added because it may interfere with xenobiotics and modify their effects, modulate algal growth performances or produce a trade-off of both effects. After 2 and 4 days of algal growth, the cell number and size, the maximum quantum yield of photosystem II in the dark or light adapted state, and the chlorophyll a content were recorded in order to evaluate the algal response to bisphenol A. Moreover, the residual bisphenol A was measured in the algal cultures by chromatographic technique. Results indicated that after 2 and 4 days bisphenol A at the lower concentrations was not toxic for alga, whereas at the highest concentration it reduced algal growth and photosynthetic efficiency. The sole NOM and its combinations with bisphenol A at the lower concentrations increased the cell number and the chlorophyll a content of algae. After 4-day growth, good removal efficiency was exerted by M. braunii at concentrations of 2, 4 and 10 mg L −1 removing, respectively, 39%, 48% and 35% of the initial bisphenol A. Lower removal percentages were found after 2-day growth in the different treatments. NOM at any concentration scarcely influenced the bisphenol A removal. On the basis of data obtained, the use of M. braunii could be reasonably recommended for the phytoremediation of aquatic environments from bisphenol A. - Highlights: ► The alga Monoraphidium braunii tolerates high concentrations of bisphenol A. ► The alga Monoraphidium

Removal of bisphenol A by the freshwater green alga Monoraphidium braunii and the role of natural organic matter

Energy Technology Data Exchange (ETDEWEB)

Gattullo, C. Eliana, E-mail: e.gattullo@agr.uniba.it [Dipartimento di Biologia e Chimica Agro-forestale e Ambientale, University of Bari, Via Amendola 165/A, 70126 Bari (Italy); Baehrs, Hanno; Steinberg, Christian E.W. [Department of Biology, Freshwater and Stress Ecology, Humboldt Universitaet zu Berlin, Spaethstr. 80/81, 12437 Berlin (Germany); Loffredo, Elisabetta [Dipartimento di Biologia e Chimica Agro-forestale e Ambientale, University of Bari, Via Amendola 165/A, 70126 Bari (Italy)

2012-02-01

Phytoremediation of waters by aquatic organisms such as algae has been recently explored for the removal of organic pollutants possessing endocrine disrupting capacity. Monoraphidium braunii, a green alga known for rapid growth and good tolerance to different natural organic matter (NOM) qualities, was tested in this study for the ability to tolerate and remove the endocrine disruptor bisphenol A at concentrations of 2, 4 and 10 mg L{sup -1}, either in NOM-free or NOM-containing media. NOM at concentrations of 2, 5 and 20 mg L{sup -1} of DOC, was added because it may interfere with xenobiotics and modify their effects, modulate algal growth performances or produce a trade-off of both effects. After 2 and 4 days of algal growth, the cell number and size, the maximum quantum yield of photosystem II in the dark or light adapted state, and the chlorophyll a content were recorded in order to evaluate the algal response to bisphenol A. Moreover, the residual bisphenol A was measured in the algal cultures by chromatographic technique. Results indicated that after 2 and 4 days bisphenol A at the lower concentrations was not toxic for alga, whereas at the highest concentration it reduced algal growth and photosynthetic efficiency. The sole NOM and its combinations with bisphenol A at the lower concentrations increased the cell number and the chlorophyll a content of algae. After 4-day growth, good removal efficiency was exerted by M. braunii at concentrations of 2, 4 and 10 mg L{sup -1} removing, respectively, 39%, 48% and 35% of the initial bisphenol A. Lower removal percentages were found after 2-day growth in the different treatments. NOM at any concentration scarcely influenced the bisphenol A removal. On the basis of data obtained, the use of M. braunii could be reasonably recommended for the phytoremediation of aquatic environments from bisphenol A. - Highlights: Black-Right-Pointing-Pointer The alga Monoraphidium braunii tolerates high concentrations of bisphenol A

Marine Algae: a Source of Biomass for Biotechnological Applications.

Science.gov (United States)

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.

Algae Derived Biofuel

Energy Technology Data Exchange (ETDEWEB)

Jahan, Kauser [Rowan Univ., Glassboro, NJ (United States)

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.

Bioaccumulation and effects of novel chlorinated polyfluorinated ether sulfonate in freshwater alga Scenedesmus obliquus.

Science.gov (United States)

Liu, Wei; Li, Jingwen; Gao, Lichen; Zhang, Zhou; Zhao, Jing; He, Xin; Zhang, Xin

2018-02-01

Chlorinated polyfluorinated ether sulfonate (Cl-PFESA) is a novel alternative compound for perfluorooctane sulfonate (PFOS), with its environmental risk not well known. The bioaccumulation and toxic effects of Cl-PFESA in the freshwater alga is crucial for the understanding of its potential hazards to the aquatic environment. Scenedesmus obliquus was exposed to Cl-PFESA at ng L -1 to mg L -1 , with the exposure regime beginning at the environmentally relevant level. The total log BAF of Cl-PFESA in S. obliquus was 4.66, higher than the reported log BAF of PFOS in the freshwater plankton (2.2-3.2). Cl-PFESA adsorbed to the cell surface accounted for 33.5-68.3% of the total concentrations. The IC50 of Cl-PFESA to algal growth was estimated to be 40.3 mg L -1 . Significant changes in algal growth rate and chlorophyll a/b contents were observed at 11.6 mg L -1 and 13.4 mg L -1 of Cl-PFESA, respectively. The sample cell membrane permeability, measured by the fluorescein diacetate hydrolyzation, was increased by Cl-PFESA at 5.42 mg L -1 . The mitochondrial membrane potential, measured by Rh123 staining, was also increased, indicating the hyperpolarization induced by Cl-PFESA. The increasing ROS and MDA contents, along with the enhanced SOD, CAT activity, and GSH contents, suggested that Cl-PFESA caused oxidative damage in the algal cells. It is less possible that current Cl-PFESA pollution in surface water posed obvious toxic effects on the green algae. However, the bioaccumulation of Cl-PFESA in algae would contribute to its biomagnification in the aquatic food chain and its effects on membrane property could potentially increase the accessibility and toxicity of other coexisting pollutants. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

Science.gov (United States)

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. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

MACRO

International Nuclear Information System (INIS)

Rogner, H.H.

1989-01-01

The description is given to MACRO which is a numerically formulated macroeconomic model constructed to reflect the economy of the European Community. The model belongs to the group of general equilibrium models often applied in long-term macroeconomic energy modeling. Furthermore, MACRO was designed so as to interact with other more technically oriented energy demand and supply models. It's main objective is to provide consistency checks between assumptions concerning energy trade, energy prices, resource availability and energy-related capital requirements. 5 figs

Presence, fate and effects of the intense sweetener sucralose in the aquatic environment

International Nuclear Information System (INIS)

Tollefsen, Knut Erik; Nizzetto, Luca; Huggett, Duane B.

2012-01-01

Sucralose (1,6-dichloro-1,6-dideoxy-b-D-fructo-furanosyl 4-chloro-4-deoxy-a-D-galactopyranoside), sold under the trade name Splenda®, has been detected in municipal effluents and surface waters in the United States and Europe. The environmental presence of sucralose has led to interest in the possibility of toxic effects in non-target species. This review presents an environmental risk assessment of sucralose based on available data concerning its presence, fate and effects in the environment. Sucralose, which is made by selective chlorination of sucrose, is a highly stable compound, which undergoes negligible metabolism in mammals, including humans, and displays a low biodegradation potential in the environment. This intense sweetener is highly soluble in water, displays a low bioaccumulation potential and a low sorption potential to soil and organic matter, and thus is predominantly present in the water column. The predicted environmental concentration (PEC) for sucralose, based on measured data in surface waters, was determined to be 10 μg/L. Aquatic toxicity studies using standardized, validated protocols used in regulatory decision making indicate that sucralose does not alter survival, growth and reproduction of aquatic organisms (such as plants, algae, crustaceans and fish) at concentrations > 9000 times higher than those detected in the environment. Some studies, using non-standardized protocols, have reported behavioral and other non-traditional responses in aquatic organisms, but the relevance of these findings for assessing adverse effects on individuals and populations will require further investigation. In terms of traditional risk assessment, the proposed predicted no effect concentration for aquatic organisms (PNEC) was determined to be 0.93 mg/L, based on the lowest no effect concentration (NOEC) from a validated chronic study with mysid shrimp and an application factor of 100. The resultant PEC/PNEC quotient was determined to be well below 1 (PEC

Presence, fate and effects of the intense sweetener sucralose in the aquatic environment

Energy Technology Data Exchange (ETDEWEB)

Tollefsen, Knut Erik, E-mail: ket@niva.no [Norwegian Institute for Water Research (NIVA), Gaustadalleen 21, N-0349 Oslo (Norway); Nizzetto, Luca [Norwegian Institute for Water Research (NIVA), Gaustadalleen 21, N-0349 Oslo (Norway); Huggett, Duane B. [Department of Biological Sciences, University of North Texas, P.O. Box 310559, Denton, TX 76203 (United States)

2012-11-01

Sucralose (1,6-dichloro-1,6-dideoxy-b-D-fructo-furanosyl 4-chloro-4-deoxy-a-D-galactopyranoside), sold under the trade name Splenda Registered-Sign , has been detected in municipal effluents and surface waters in the United States and Europe. The environmental presence of sucralose has led to interest in the possibility of toxic effects in non-target species. This review presents an environmental risk assessment of sucralose based on available data concerning its presence, fate and effects in the environment. Sucralose, which is made by selective chlorination of sucrose, is a highly stable compound, which undergoes negligible metabolism in mammals, including humans, and displays a low biodegradation potential in the environment. This intense sweetener is highly soluble in water, displays a low bioaccumulation potential and a low sorption potential to soil and organic matter, and thus is predominantly present in the water column. The predicted environmental concentration (PEC) for sucralose, based on measured data in surface waters, was determined to be 10 {mu}g/L. Aquatic toxicity studies using standardized, validated protocols used in regulatory decision making indicate that sucralose does not alter survival, growth and reproduction of aquatic organisms (such as plants, algae, crustaceans and fish) at concentrations > 9000 times higher than those detected in the environment. Some studies, using non-standardized protocols, have reported behavioral and other non-traditional responses in aquatic organisms, but the relevance of these findings for assessing adverse effects on individuals and populations will require further investigation. In terms of traditional risk assessment, the proposed predicted no effect concentration for aquatic organisms (PNEC) was determined to be 0.93 mg/L, based on the lowest no effect concentration (NOEC) from a validated chronic study with mysid shrimp and an application factor of 100. The resultant PEC/PNEC quotient was determined to be

The macro-invertebrates and their value like indicators of the water quality

International Nuclear Information System (INIS)

Roldan Perez, Gabriel

1999-01-01

An analysis of the water pollution problems is presented and some of the more used methods for assessment of its damage degree through bio indicators are discussed. There are biological methods for assessment of water quality widely used in developed countries. Because the aquatic fauna existing there is different from the one here, those methods cannot be applied in the tropics before knowing what kinds of organisms live here and what ecological requirements they have. The adoption of a method for assessment of water quality in tropical mountains ecosystems is proposed, using macro invertebrates as bio indicators

The quantity of algae colonizing the inside face of cooling towers and the consequences for wear of the shell

International Nuclear Information System (INIS)

Aprosi, G.; Chauvel, D.

1990-01-01

These studies are part of the interdirectorate working group's mandate relating to lifespan project on cooling towers. Involving the collaboration of several divisions of Electricity de France: the Construction Division (SEPTEN). The Generation and Transmission Division (SPT) and the Research and Development Division (EAA). Among the biological colonies which proliferate in the cooling circuits of power stations, algae are broadly represented in the form of wall coatings which cover the inside face of cooling towers: shell algae. They can also grow at other points in the cooling circuit; in the cold water basin, in the fill, and, in some cooling towers, in the hot water basin. These plant organisms hamper the operation of power stations by clogging the grids located in the pipe from the cold water basin to the condenser. In addition, when algae come free of the shell, they remove micro-fragments of the concrete, which could accelerate wear. This paper presents the findings of studies conducted by the Aquatic and Atmospheric Department on the infestation of cooling towers by algae. In particular, the results of studies to evaluate the quantity of algae on the inside face of the shell of cooling towers. Many scenarios will be proposed, linked to the operation of the plant and to the local meteorological conditions

Biofuels and algae

International Nuclear Information System (INIS)

Anon.

2011-01-01

Bio-fuels based on micro-algae are promising, their licensing for being used in plane fuels in a mix containing 50% of fossil kerosene is expected in the coming months. In United-States research on bio-fuels has been made more important since 2006 when 2 policies were launched: 'Advanced energy initiative' and 'Twenty-in-ten', the latter aiming to develop alternative fuels. In Europe less investment has been made concerning micro-algae fuels but research programs were launched in Spain, United-Kingdom and France. In France 3 important projects were launched: SHAMASH (2006-2010) whose aim is to produce lipidic fuels from micro-algae, ALGOHUB (2008-2013) whose aim is to use micro-algae as a raw material for humane and animal food, medicine and cosmetics, SYMBIOSE (2009-2011) whose aim is the optimization of the production of methane through the anaerobic digestion of micro-algae, SALINALGUE (2010-2016) whose aim is to grow micro-algae for the production of bio-energies and bio-products. (A.C.)

Aquatic toxicity and biodegradability of advanced cationic surfactant APA-22 compatible with the aquatic environment.

Science.gov (United States)

Yamane, Masayuki; Toyo, Takamasa; Inoue, Katsuhisa; Sakai, Takaya; Kaneko, Youhei; Nishiyama, Naohiro

2008-01-01

Cationic surfactant is a chemical substance used in hair conditioner, fabric softener and other household products. By investigating the relationship between the aquatic toxicity and the chemical structures of two types of mono alkyl cationic surfactants, alkyl trimethylammonium salts and alkyl dimethylamine salts, we have found that the C22 alkyl chain length is effective to reduce the toxicity. Besides, we have recognized that the amidopropyl functional group contributes to the enhanced biodegradability by investigating the biodegradation trend of (alkylamidopropyl)dimethylamine salt (alkyl chain length: C18). Based on these findings, we have developed mono alkyl cationic surfactant called APA-22, N-[3-(dimethylamino)propyl]docosanamide salt. APA-22 is formed by the C22 alkyl chain, amidopropyl functional group and di-methyltertiary amine group. We evaluated the aerobic and anaerobic biodegradability of APA-22 by two standard methods (OECD Test Guideline 301B and ECETOC technical document No.28) and found that this substance was degraded rapidly in both conditions. The toxicity to algae, invertebrate and fish of this substance are evaluated by using OECD Test Guideline 201, 202 and 203, respectively. All acute toxicity values are >1 mg/L, which indicates that environmental toxicity of this substance is relatively less toxic to aquatic organism. In addition, we estimated the biodegradation pathway of APA-22 and observed the complete disappearance of APA-22 and its intermediates during the test periods. Based on the environmental data provided above, we concluded that APA22 is more compatible with the aquatic environment compared to other cationic surfactants with mono long alkyl chain.

Global searches for microalgae and aquatic plants that can eliminate radioactive cesium, iodine and strontium from the radio-polluted aquatic environment: a bioremediation strategy.

Science.gov (United States)

Fukuda, Shin-Ya; Iwamoto, Koji; Atsumi, Mika; Yokoyama, Akiko; Nakayama, Takeshi; Ishida, Ken-Ichiro; Inouye, Isao; Shiraiwa, Yoshihiro

2014-01-01

The Fukushima 1 Nuclear Power Plant accident in March 2011 released an enormously high level of radionuclides into the environment, a total estimation of 6.3 × 10¹⁷ Bq represented by mainly radioactive Cs, Sr, and I. Because these radionuclides are biophilic, an urgent risk has arisen due to biological intake and subsequent food web contamination in the ecosystem. Thus, urgent elimination of radionuclides from the environment is necessary to prevent substantial radiopollution of organisms. In this study, we selected microalgae and aquatic plants that can efficiently eliminate these radionuclides from the environment. The ability of aquatic plants and algae was assessed by determining the elimination rate of radioactive Cs, Sr and I from culture medium and the accumulation capacity of radionuclides into single cells or whole bodies. Among 188 strains examined from microalgae, aquatic plants and unidentified algal species, we identified six, three and eight strains that can accumulate high levels of radioactive Cs, Sr and I from the medium, respectively. Notably, a novel eustigmatophycean unicellular algal strain, nak 9, showed the highest ability to eliminate radioactive Cs from the medium by cellular accumulation. Our results provide an important strategy for decreasing radiopollution in Fukushima area.

[Monitoring "green tide" in the Yellow Sea and the East China Sea using multi-temporal and multi-source remote sensing images].

Science.gov (United States)

Xing, Qian-Guo; Zheng, Xiang-Yang; Shi, Ping; Hao, Jia-Jia; Yu, Ding-Feng; Liang, Shou-Zhen; Liu, Dong-Yan; Zhang, Yuan-Zhi

2011-06-01

Landsat-TM (Theme Mapper) and EOS (Earth Observing System)-MODIS (MODerate resolution Imaging Spectrora-diometer) Terra/Aqua images were used to monitor the macro-algae (Ulva prolifera) bloom since 2007 at the Yellow Sea and the East China Sea. At the turbid waters of Northern Jiangsu Shoal, there is strong spectral mixing behavior, and satellite images with finer spatical resolution are more effective in detection of macro-algae patches. Macro-algae patches were detected by the Landsat images for the first time at the Sheyang estuary where is dominated by very turbid waters. The MODIS images showed that the macro-algae from the turbid waters near the Northern Jiangsu Shoal drifted southwardly in the early of May and affected the East China Sea waters; with the strengthening east-asian Summer Monsoon, macro-algae patches mainly drifted in a northward path which was mostly observed at the Yellow Sea. Macro-algae patches were also found to drift eastwardly towards the Korea Peninsular, which are supposed to be driven by the sea surface wind.

Occurrence of β-N-methylamino-l-alanine (BMAA and Isomers in Aquatic Environments and Aquatic Food Sources for Humans

Directory of Open Access Journals (Sweden)

Emilie Lance

2018-02-01

Full Text Available The neurotoxin β-N-methylamino-l-alanine (BMAA, a non-protein amino acid produced by terrestrial and aquatic cyanobacteria and by micro-algae, has been suggested to play a role as an environmental factor in the neurodegenerative disease Amyotrophic Lateral Sclerosis-Parkinsonism-Dementia complex (ALS-PDC. The ubiquitous presence of BMAA in aquatic environments and organisms along the food chain potentially makes it public health concerns. However, the BMAA-associated human health risk remains difficult to rigorously assess due to analytical challenges associated with the detection and quantification of BMAA and its natural isomers, 2,4-diamino butyric acid (DAB, β-amino-N-methyl-alanine (BAMA and N-(2-aminoethyl glycine (AEG. This systematic review, reporting the current knowledge on the presence of BMAA and isomers in aquatic environments and human food sources, was based on a selection and a score numbering of the scientific literature according to various qualitative and quantitative criteria concerning the chemical analytical methods used. Results from the best-graded studies show that marine bivalves are to date the matrix containing the higher amount of BMAA, far more than most fish muscles, but with an exception for shark cartilage. This review discusses the available data in terms of their use for human health risk assessment and identifies knowledge gaps requiring further investigations.

Occurrence of β-N-methylamino-l-alanine (BMAA) and Isomers in Aquatic Environments and Aquatic Food Sources for Humans.

Science.gov (United States)

Lance, Emilie; Arnich, Nathalie; Maignien, Thomas; Biré, Ronel

2018-02-14

The neurotoxin β- N -methylamino-l-alanine (BMAA), a non-protein amino acid produced by terrestrial and aquatic cyanobacteria and by micro-algae, has been suggested to play a role as an environmental factor in the neurodegenerative disease Amyotrophic Lateral Sclerosis-Parkinsonism-Dementia complex (ALS-PDC). The ubiquitous presence of BMAA in aquatic environments and organisms along the food chain potentially makes it public health concerns. However, the BMAA-associated human health risk remains difficult to rigorously assess due to analytical challenges associated with the detection and quantification of BMAA and its natural isomers, 2,4-diamino butyric acid (DAB), β-amino- N -methyl-alanine (BAMA) and N -(2-aminoethyl) glycine (AEG). This systematic review, reporting the current knowledge on the presence of BMAA and isomers in aquatic environments and human food sources, was based on a selection and a score numbering of the scientific literature according to various qualitative and quantitative criteria concerning the chemical analytical methods used. Results from the best-graded studies show that marine bivalves are to date the matrix containing the higher amount of BMAA, far more than most fish muscles, but with an exception for shark cartilage. This review discusses the available data in terms of their use for human health risk assessment and identifies knowledge gaps requiring further investigations.

The long-term persistence of phytoplankton resting stages in aquatic "seed banks"

DEFF Research Database (Denmark)

Ellegaard, Marianne; Ribeiro, Sofia

2018-01-01

to terrestrial seed beds of vascular plants, but are much less studied. It is therefore timely to review the phenomenon of long-term persistence of aquatic resting stages in sediment seed banks. Herein we compare function, morphology and physiology of phytoplankton resting stages to factors central...... for persistence of terrestrial seeds. We review the types of resting stages found in different groups of phytoplankton and focus on the groups for which long-term (multi-decadal) persistence has been shown: dinoflagellates, diatoms, green algae and cyanobacteria. We discuss the metabolism of long-term dormancy......In the past decade, research on long-term persistence of phytoplankton resting stages has intensified. Simultaneously, insight into life-cycle variability in the diverse groups of phytoplankton has also increased. Aquatic 'seed banks' have tremendous significance and show many interesting parallels...

Radiobiological and radioecological studies with the unicellular marine algae Acetabularia, Batophora and Dunaliella

International Nuclear Information System (INIS)

Bonotto, S.; Luttke, A.; Strack, S.; Kirchmann, R.; Hoursiangou, D.; Puiseux-Dao, S.

1980-01-01

The biological effects of X-rays on the unicellular marine algae Acetabularia mediterranea, Acetabularia peniculus and Batophora oerstedii were studied. Increasing doses of X-rays (0 to 150 kr) were shown to interfere with the main morphogenetic processes of these algae. Labelling experiments with 3 H-thymidine, 3 H-uridine and 3 H-leucine showed that X-rays (50 kr) provoked a strong reduction of DNA, RNA and protein synthesis in the chloroplasts of A. mediterranea. Radioecological studies were also performed showing that Acetabularia cells, grown in the presence of HTO, incorporate a significant amount of 3 H in the total nucleic acid and protein fraction. However, 3 H supplied to Acetabularia in the form of tritiated water was not accumulated. When organically bound 3 H was supplied to Acetabularia or to Dunaliella, a selective accumulation of some substances was observed. Thus the results of this study illustrate the impact of radiation on living organisms and the biological behaviour of 3 H in the aquatic system. (UK)

Toxicity of anthelmintic drugs (fenbendazole and flubendazole) to aquatic organisms.

Science.gov (United States)

Wagil, Marta; Białk-Bielińska, Anna; Puckowski, Alan; Wychodnik, Katarzyna; Maszkowska, Joanna; Mulkiewicz, Ewa; Kumirska, Jolanta; Stepnowski, Piotr; Stolte, Stefan

2015-02-01

Flubendazole (FLU) and fenbendazole (FEN) belong to benzimidazoles-pharmaceuticals widely used in veterinary and human medicine for the treatment of intestinal parasites as well as for the treatment of systemic worm infections. In recent years, usage of these drugs increased, which resulted in a larger contamination of the environment and possible negative effects on biota. Hence, in our research, we investigated an aquatic ecotoxicity of these pharmaceuticals towards: marine bacteria (Vibrio fischeri), green algae (Scenedesmus vacuolatus), duckweed (Lemna minor) and crustacean (Daphnia magna). Ecotoxicity tests were combined with chemical analysis in order to investigate the actual exposure concentration of the compounds used in the experiment as well as to stability and adsorption studies. As a result, study evaluating sensitivity of different aquatic organisms to these compounds and new ecotoxicological data is presented. The strongest negative impact of FLU and FEN was observed to D. magna.

Influence of Speciation of Thorium on Toxic Effects to Green Algae Chlorella pyrenoidosa

Directory of Open Access Journals (Sweden)

Can Peng

2017-04-01

Full Text Available Thorium (Th is a natural radioactive element present in the environment and has the potential to be used as a nuclear fuel. Relatively little is known about the influence and toxicity of Th in the environment. In the present study, the toxicity of Th to the green algae Chlorella pyrenoidosa (C. pyrenoidosa was evaluated by algal growth inhibition, biochemical assays and morphologic observations. In the cultural medium (OECD TG 201, Th(NO34 was transformed to amorphous precipitation of Th(OH4 due to hydrolysis. Th was toxic to C. pyrenoidosa, with a 96 h half maximum effective concentration (EC50 of 10.4 μM. Scanning electron microscopy shows that Th-containing aggregates were attached onto the surface of the algal cells, and transmission electron microscopy indicates the internalization of nano-sized Th precipitates and ultrastructural alterations of the algal cells. The heteroagglomeration between Th(OH4 precipitation and alga cells and enhanced oxidative stress might play important roles in the toxicity of Th. To our knowledge, this is the first report of the toxicity of Th to algae with its chemical species in the exposure medium. This finding provides useful information on understanding the fate and toxicity of Th in the aquatic environment.

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

Science.gov (United States)

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

Parser Macros for Scala

OpenAIRE

Duhem, Martin; Burmako, Eugene

2015-01-01

Parser macros are a new kind of macros that allow developers to create new language constructs and to define their own syntax for using them. In this report, we present why parser macros are useful and the kind of problems that they help to solve. We will also see how they are implemented and gain insight about how they take advantage from scala.meta, the new metaprogramming toolkit for Scala. Finally, we will discuss what are the current limitations of parser macros and what is left for futu...

Ecological effects assessment of anionic surfactant on aquatic ecosystem using microcosm system; Microcosm wo mochiita in ion kaimen kasseizai no suiken seitaikei ni oyobosu eikyo hyoka

Energy Technology Data Exchange (ETDEWEB)

Takamatsu, Y. [University of Tsukuba, Tsukuba (Japan); Inamori, Y. [National Institute for Environmental Studies, Tsukuba (Japan); Sudo, R. [Tohoku University, Sendai (Japan). Faculty of Engineering; Kurihara, Y. [Ou Univ., Fukushima (Japan). Faculty of Engineering; Matsumura, M. [University of Tsukuba, Tsukuba (Japan). Institute of Applied Biochemical

1997-11-10

Microcosm system was applied to assess effect of anionic surfactant (LAS) on aquatic ecosystem. Anionic surfactant such as LAS was added to an flask microcosm consisting of four species of bacteria as decomposer, one species of ciliate protozoa (Cyclidium glaucoma), two rotifers (Philodina sp. and Lepadella sp.) and one aquatic oligochaete (Aeolosoma hemprichi) as predator, and a green alga (Chlorella sp.) and a filamentous blue-green alga (Tolypothrix sp.) as producer, comparing with that of an natural lake model ecosystem derived from natural lake water. In the flask microcosm system and the natural lake model ecosystem, biodegradation rates of LAS were almost same and NOECs (no observed effect concentration) of LAS were also below 1.5 mg{center_dot} l{sup -1}. It was found that flask microcosm test could provide precise ecological effect assessment of LAS on number of microorganisms because the system showed higher reproducibility and stability than natural take model ecosystem. It was suggested that flask microcosm test was useful ecological effect assessment method which can reflect natural aquatic ecosystem. 10 refs., 4 figs., 2 tabs.

Actinide elements in aquatic and terrestrial environments

International Nuclear Information System (INIS)

Bondietti, E.A.

1978-01-01

Progress is reported in terrestrial ecology studies with regard to plutonium in biota from the White Oak Creek forest; comparative distribution of plutonium in two forest ecosystems; an ecosystem model of plutonium dynamics; actinide element metabolism in cotton rats; and crayfish studies. Progress is reported in aquatic studies with regard to transuranics in surface waters, frogs, benthic algae, and invertebrates from pond 3513; and radioecology of transuranic elements in cotton rats bordering waste pond 3513. Progress is also reported in stability of trivalent plutonium in White Oak Lake water; chemistry of plutonium, americium, curium, and uranium in pond water; uranium, thorium, and plutonium in small mammals; and effect of soil pretreatment on the distribution of plutonium

Algae potential resource assessment for the energy and chemistry sectors in France by 2030

International Nuclear Information System (INIS)

Kerlero De Rosbo, Guillaume; Payen, Luc; Bernard, Olivier; Mairet, Francis; Grimaud, Ghjuvan; Delclaux, Etienne; Rey, David; Ras De Moncuit, Monique; Houdon, Aude-Claire; Gagnepain, Bruno; Gueudet, Alice; El Khamlichi, Aicha; Delalande, Claire; Eglin, Thomas; Pouet, Jean-Christophe; Allouche, Yohan; Lombard, Christophe; Mhiri, Tarek; Mazzenga, Anthony; Lasserre, Thomas; Potin, Philippe; Kaas, Raymond; Lecurieux-Belfond, Laura

2014-07-01

To address environmental and climate issues, alternative technologies to fossil resources are sought after, both for the production of fuels and of chemicals. Algae appear as an attractive solution and have applications in the food, feed, energy or chemistry at large. A study funded by ADEME and conducted by ENEA, a consulting firm for energy and sustainable development for the industrial sector, in partnership with INRIA assessed the potential of algal French resources (micro- and macro-algae) for the production of advanced bio-fuels and molecules of interest (bio-plastic, nutrients etc.) in 2030. This assessment is based both on a model of the French national resources (physical production potential without the use of agricultural land) and what the we now know of the markets concerned and their projection 2030. The analysis shows a physical potential output of up to 9% of the French bio-diesel consumption in 2030 and enough to supply many European markets in algal bio-products. R and d efforts are however required to achieve sufficient technical and economic performance to fully exploit this potential

A New Treatment Strategy for Inactivating Algae in Ballast Water Based on Multi-Trial Injections of Chlorine.

Science.gov (United States)

Sun, Jinyang; Wang, Junsheng; Pan, Xinxiang; Yuan, Haichao

2015-06-09

Ships' ballast water can carry aquatic organisms into foreign ecosystems. In our previous studies, a concept using ion exchange membrane electrolysis to treat ballast water has been proven. In addition to other substantial approaches, a new strategy for inactivating algae is proposed based on the developed ballast water treatment system. In the new strategy, the means of multi-trial injection with small doses of electrolytic products is applied for inactivating algae. To demonstrate the performance of the new strategy, contrast experiments between new strategies and routine processes were conducted. Four algae species including Chlorella vulgaris, Platymonas subcordiformis, Prorocentrum micans and Karenia mikimotoi were chosen as samples. The different experimental parameters are studied including the injection times and doses of electrolytic products. Compared with the conventional one trial injection method, mortality rate time (MRT) and available chlorine concentration can be saved up to about 84% and 40%, respectively, under the application of the new strategy. The proposed new approach has great potential in practical ballast water treatment. Furthermore, the strategy is also helpful for deep insight of mechanism of algal tolerance.

TiO2 as a photocatalyst for control of the aquatic invasive alga, Cladophora, under natural and artificial light

Science.gov (United States)

Peller, J.R.; Whitman, R.L.; Griffith, S.; Harris, P.; Peller, C.; Scalzitti, J.

2007-01-01

Cladophora, a nuisance and invasive, filamentous algae (Chlorophyta), massively accumulates along the shores of the lower Great Lakes each summer causing great economic damage and compromising recreational opportunity and perhaps public health. In vitro experiments showed that Cladophora samples were physically and biologically degraded when subjected to TiO2-mediated photocatalysis. For the most successful photocatalytic process, TiO2 was immobilized on a glass surface and used in combination with either sunlight or artificial UV light. The loss of vital algal pigments was monitored using UV–vis spectrophotometry, and cell structural changes were determined by microscopic observation. Cladophora, in the presence of TiO2-covered glass beads, experienced a loss of chloroplast pigments after 2 h of UV lamp light irradiation. In a separate experiment, sunlight exposure over 4 days (∼24 h) resulted in the complete oxidative degradation of the green chloroplast pigments, verified by the UV spectra of the algal extracts. These results suggest that TiO2, mobilized on sunlit silicates may be useful in controlling growth and survival of this alga in the Great Lakes, thus mitigating many of the economic, aesthetic ecological impacts of this invasive alga.

Uptake of uranium by aquatic plants growing in fresh water ecosystem around uranium mill tailings pond at Jaduguda, India.

Science.gov (United States)

Jha, V N; Tripathi, R M; Sethy, N K; Sahoo, S K

2016-01-01

Concentration of uranium was determined in aquatic plants and substrate (sediment or water) of fresh water ecosystem on and around uranium mill tailings pond at Jaduguda, India. Aquatic plant/substrate concentration ratios (CRs) of uranium were estimated for different sites on and around the uranium mill tailings disposal area. These sites include upstream and downstream side of surface water sources carrying the treated tailings effluent, a small pond inside tailings disposal area and residual water of this area. Three types of plant groups were investigated namely algae (filamentous and non-filamentous), other free floating & water submerged and sediment rooted plants. Wide variability in concentration ratio was observed for different groups of plants studied. The filamentous algae uranium concentration was significantly correlated with that of water (r=0.86, puranium concentration in plant and the substrate (r=0.88, puranium concentration was significantly correlated with Mn, Fe, and Ni concentration of plants (puranium accumulation and concentration ratio can be useful for prospecting phytoremediation of stream carrying treated or untreated uranium mill tailings effluent. Copyright © 2015 Elsevier B.V. All rights reserved.

Occurrence of antibiotics in water, sediments, aquatic plants, and animals from Baiyangdian Lake in North China.

Science.gov (United States)

Li, Wenhui; Shi, Yali; Gao, Lihong; Liu, Jiemin; Cai, Yaqi

2012-11-01

This study investigated the presence and distribution of 22 antibiotics, including eight quinolones, nine sulfonamides and five macrolides, in the water, sediments, and biota samples from Baiyangdian Lake, China. A total of 132 samples were collected in 2008 and 2010, and laboratory analyses revealed that antibiotics were widely distributed in the lake. Sulfonamides were the dominant antibiotics in the water (0.86-1563 ng L(-1)), while quinolones were prominent in sediments (65.5-1166 μg kg(-1)) and aquatic plants (8.37-6532 μg kg(-1)). Quinolones (17.8-167 μg kg(-1)) and macrolides [from below detection limit (BDL) to 182 μg kg(-1)] were often found in aquatic animals and birds. Salvinia natans exhibited the highest bioaccumulation capability for quinolones among three species of aquatic plants. Geographical differences of antibiotic concentrations were greatly due to anthropogenic activities. Sewage discharged from Baoding City was likely the main source of antibiotics in the lake. Risk assessment of antibiotics on aquatic organisms suggested that algae and aquatic plants might be at risk in surface water, while animals were likely not at risk. Copyright © 2012 Elsevier Ltd. All rights reserved.

Gene expression profiling of ramie roots during hydroponic induction and adaption to aquatic environment

Directory of Open Access Journals (Sweden)

Gang Gao

2017-12-01

Full Text Available Ramie (Boehmeria nivea (L. Gaud. is a traditionally terrestrial fiber crop. However, hydroponic technology can enhance the quantity and quality of disease free Ramie plant seedlings for field cultivation. To date, few studies have attempted to examine the hydroponic induction of ramie roots and the molecular responses of ramie roots to aquatic environment. In this study, ramie tender stems was grown in the soil or in a hydroponic water solution, and cultured in the same environmental conditions. Root samples of terrestrial ramie, and different developmental stages of hydroponic ramie (5 days, 30 days, were firstly pooled for reference transcriptome sequencing by Illumina Hiseq 2000. Gene expression levels of each samples were quantified using the BGISEQ500 platform to help understand the distribution of aquatic root development related genes at the macro level (GSE98903. Our data resources provided an opportunity to elucidate the adaptation mechanisms of ramie seedlings roots in aquatic environment.

Effects of sonication and advanced chemical oxidants on the unicellular green alga Dunaliella tertiolecta and cysts, larvae and adults of the brine shrimp Artemia salina: a prospective treatment to eradicate invasive organisms from ballast water.

Science.gov (United States)

Gavand, Meghana R; McClintock, James B; Amsler, Charles D; Peters, Robert W; Angus, Robert A

2007-11-01

Uptake and release of ship-borne ballast water is a major factor contributing to introductions of aquatic phytoplankton and invasive macroinvertebrates. Some invasive unicellular algae can cause harmful algal blooms and produce toxins that build up in food chains. Moreover, to date, few studies have compared the efficacy of ballast water treatments against different life history phases of aquatic macroinvertebrates. In the present study, the unicellular green alga Dunaliella tertiolecta, and three discrete life history phases of the brine shrimp Artemia salina, were independently used as model organisms to study the efficacy of sonication as well as the advanced oxidants, hydrogen peroxide and ozone, as potential ballast water treatments. Algal cells and brine shrimp cysts, nauplii, and adults were subjected to individual and combined treatments of sonication and advanced oxidants. Combined rather than individual treatments consistently yielded the highest levels of mortality in algal cells (100% over a 2 min exposure) and in brine shrimp (100% and 95% for larvae and adults, respectively, over a 2 min exposure). In contrast, mortality levels in brine shrimp cysts (66% over 2 min; increased to 92% over a 20 min exposure) were moderately high but consistently lower than that detected for larval or adult shrimp. Our results indicate that a combination of sonication and advanced chemical oxidants may be a promising method to eradicate aquatic unicellular algae and macroinvertebrates in ballast water.

Blue-Green Algae

Science.gov (United States)

... that taking a specific blue-green algae product (Super Blue-Green Algae, Cell Tech, Klamath Falls, OR) ... system. Premenstrual syndrome (PMS). Depression. Digestion. Heart disease. Memory. Wound healing. Other conditions. More evidence is needed ...

101 Ready-To-Use Excel Macros

CERN Document Server

Alexander, Michael

2012-01-01

Save time and be more productive with this helpful guide to Excel macros! While most books about Excel macros offer only minor examples, usually aimed at illustrating a particular topic, this invaluable resource provides you with the tools needed to efficiently and effectively program Excel macros immediately. Step-by-step instructions show you how to create VBA macros and explain how to customize your applications to look and work exactly as you want them to. By the end of the book, you will understand how each featured macro works, be able to reuse the macros included in the book and online,

The opportunities for obtaining of the biogas on methane fermentation from marine algae biomass and water plant biomass

Directory of Open Access Journals (Sweden)

Jachniak Ewa

2018-01-01

Full Text Available The aim of the research was to try to obtain of the biogas on a laboratory scale from marine algae biomass and water plant biomass. The research was conducted in 2016 year and samples were taken from the Polish coast of the Baltic Sea. In laboratory work, algae and plant species were first identified. The next, in order to subject them to methane fermentation processes and to obtain biogas,partial mechanical treatment of the biomass was conducted. Dry matter content and dry organic matter content were also determined. The research has shown different production of the biogas depending on the various species of the algae and plants. The percentage composition of the biogas was also determined (% CO2 and % CH4. In this research some kinds and species of algae and aquatic plants were distinguished: Scytosiphon cf. S. tortilis, Fucus vesiculosus, Cladophora, Audouinella, Potamogeton perfoliatus. Production of biogas from selected algae and water plants oscillated between 0.023 dm3·g-1 and 0.303 dm3·g-1. The highest content of the methane in biogas was obtained from the mixture of Ectocarpus from spring and autumn harvest (values oscillated from 80.7 % to 81.2 %, while the highest percentage share of carbon dioxide in the biogas was characterized by the mixture Fucus vesiculosus and Audouinella (22 %. Due to a small amount of the research in this field, more research is needed.

A microcosm system to evaluate the toxicity of the triazine herbicide simazine on aquatic macrophytes

International Nuclear Information System (INIS)

Vervliet-Scheebaum, Marco; Straus, Alain; Tremp, Horst; Hamer, Mick; Maund, Stephen J.; Wagner, Edgar; Schulz, Ralf

2010-01-01

This study evaluates the effects of the triazine herbicide simazine in an outdoor pond microcosm test system that contained two submerged rooted species (Myriophyllum spicatum and Elodea canadensis) and two emergent rooted species (Persicaria amphibia and Glyceria maxima) over a period of 84 days. Simazine was applied to the microcosms at nominal concentrations of 0.05, 0.5 and 5 mg/L. General biological endpoints and physiological endpoints were used to evaluate herbicide toxicity on macrophytes and the algae developing naturally in the system. Concentration-related responses of macrophytes and algae were obtained for the endpoints selected, resulting in a no observed ecologically adverse effect concentration (NOEAEC) at simazine concentrations of 0.05 mg active ingredient/L after 84 days. E. canadensis was the most negatively affected species based on length increase, which was consistently a very sensitive parameter for all macrophytes. The experimental design presented might constitute a suitable alternative to conventional laboratory single-species testing. - Simazine at concentrations of 0.05 mg/L does not cause long-term negative effects to aquatic macrophytes or algae.

A microcosm system to evaluate the toxicity of the triazine herbicide simazine on aquatic macrophytes

Energy Technology Data Exchange (ETDEWEB)

Vervliet-Scheebaum, Marco, E-mail: marco.vervliet@biologie.uni-freiburg.d [Plant Biotechnology, Faculty of Biology, University of Freiburg, Schaenzlestr. 1, 79104 Freiburg (Germany); Straus, Alain [Plant Biotechnology, Faculty of Biology, University of Freiburg, Schaenzlestr. 1, 79104 Freiburg (Germany); Tremp, Horst [Institute for Environmental Sciences, University Koblenz-Landau, Fortstr. 7, 76829 Landau (Germany); Hamer, Mick [Ecological Sciences, Syngenta Crop Protection AG, Jealott' s Hill International Research Centre, Bracknell, Berkshire RG42 6EY (United Kingdom); Maund, Stephen J. [Ecological Sciences, Syngenta Crop Protection AG, 4002 Basel (Switzerland); Wagner, Edgar [Plant Biotechnology, Faculty of Biology, University of Freiburg, Schaenzlestr. 1, 79104 Freiburg (Germany); Schulz, Ralf [Institute for Environmental Sciences, University Koblenz-Landau, Fortstr. 7, 76829 Landau (Germany)

2010-02-15

This study evaluates the effects of the triazine herbicide simazine in an outdoor pond microcosm test system that contained two submerged rooted species (Myriophyllum spicatum and Elodea canadensis) and two emergent rooted species (Persicaria amphibia and Glyceria maxima) over a period of 84 days. Simazine was applied to the microcosms at nominal concentrations of 0.05, 0.5 and 5 mg/L. General biological endpoints and physiological endpoints were used to evaluate herbicide toxicity on macrophytes and the algae developing naturally in the system. Concentration-related responses of macrophytes and algae were obtained for the endpoints selected, resulting in a no observed ecologically adverse effect concentration (NOEAEC) at simazine concentrations of 0.05 mg active ingredient/L after 84 days. E. canadensis was the most negatively affected species based on length increase, which was consistently a very sensitive parameter for all macrophytes. The experimental design presented might constitute a suitable alternative to conventional laboratory single-species testing. - Simazine at concentrations of 0.05 mg/L does not cause long-term negative effects to aquatic macrophytes or algae.

Co-occurrence of the Cyanotoxins BMAA, DABA and Anatoxin-a in Nebraska Reservoirs, Fish, and Aquatic Plants

OpenAIRE

Al-Sammak, Maitham; Hoagland, Kyle; Cassada, David; Snow, Daniel

2014-01-01

Several groups of microorganisms are capable of producing toxins in aquatic environments. Cyanobacteria are prevalent blue green algae in freshwater systems, and many species produce cyanotoxins which include a variety of chemical irritants, hepatotoxins and neurotoxins. Production and occurrence of potent neurotoxic cyanotoxins β-N-methylamino-l-alanine (BMAA), 2,4-diaminobutyric acid dihydrochloride (DABA), and anatoxin-a are especially critical with environmental implications to public and...

Micro-processus et macro-structures

Directory of Open Access Journals (Sweden)

Aaron Victor Cicourel

2008-10-01

Full Text Available Des approches sociologiques traditionnelles ont défini des macro-structures sociales comme un niveau particulier de la réalité sociale, à distinguer des micro-épisodes de l’action sociale. Cela les a conduits à concevoir ces macro-structures et à mener des recherches sur elles de manière plus ou moins indépendante des pratiques observables de la vie quotidienne. Cicourel soutient que les faits (macro-sociaux ne sont pas simplement donnés, mais émergent de pratiques routinières de la vie de tous les jours. Le macro, au sens de descriptions résumées, hors contexte, normalisées et typifiées, est un produit typique des procédures interactives et organisationnelles qui transforment les micro-événements en structures macro-sociales. Ainsi une précondition pour l’intégration des phénomènes micro- et macro-sociaux dans notre théorie et dans notre méthodologie renvoie à l’identification des processus contribuant à la création de macro-structures par des inférences routinières, des interprétations et des procédure de résumé. Le texte montre aussi que les différences entre approches micro-sociologiques apparaissent parallèles à celles existant entre approches micro et macro. On se centrant sur de petits fragments d’interactions conversationnelles, certains travaux micro-sociologiques tendent à ignorer ce qui informe ces interactions conversationnelles pour les participants eux-mêmes. Les comptes rendus décontextualisés produits par de telles méthodes ressemblent à la décontextualisation résultant des procédures macro-sociologiques d’agrégation. Contre cela, Cicourel défend la constitution de bases de données comparatives n’incluant pas seulement le contexte des interactions de face à face, mais étudiant aussi les phénomènes sociaux de manière systématique à travers différents contextes.Micro-processes and macro-structures. Notes on articulation between different levels of analysis

Uptake of uranium by aquatic plants growing in fresh water ecosystem around uranium mill tailings pond at Jaduguda, India

Energy Technology Data Exchange (ETDEWEB)

Jha, V.N., E-mail: jhavn1971@gmail.com; Tripathi, R.M., E-mail: tripathirm@yahoo.com; Sethy, N.K., E-mail: sethybarc@rediffmail.com; Sahoo, S.K., E-mail: sksbarc@gmail.com

2016-01-01

Concentration of uranium was determined in aquatic plants and substrate (sediment or water) of fresh water ecosystem on and around uranium mill tailings pond at Jaduguda, India. Aquatic plant/substrate concentration ratios (CRs) of uranium were estimated for different sites on and around the uranium mill tailings disposal area. These sites include upstream and downstream side of surface water sources carrying the treated tailings effluent, a small pond inside tailings disposal area and residual water of this area. Three types of plant groups were investigated namely algae (filamentous and non-filamentous), other free floating & water submerged and sediment rooted plants. Wide variability in concentration ratio was observed for different groups of plants studied. The filamentous algae uranium concentration was significantly correlated with that of water (r = 0.86, p < 0.003). For sediment rooted plants significant correlation was found between uranium concentration in plant and the substrate (r = 0.88, p < 0.001). Both for other free floating species and sediment rooted plants, uranium concentration was significantly correlated with Mn, Fe, and Ni concentration of plants (p < 0.01). Filamentous algae, Jussiaea and Pistia owing to their high bioproductivity, biomass, uranium accumulation and concentration ratio can be useful for prospecting phytoremediation of stream carrying treated or untreated uranium mill tailings effluent. - Highlights: • Uranium mill tailings pond. • Jaduguda, India. • Fresh water plants. • Uranium uptake. • Relationship of uranium with stable elements.

Formation of algae growth constitutive relations for improved algae modeling.

Energy Technology Data Exchange (ETDEWEB)

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.

The interactive effects of microcystin-LR and cylindrospermopsin on the growth rate of the freshwater algae Chlorella vulgaris.

Science.gov (United States)

Pinheiro, Carlos; Azevedo, Joana; Campos, Alexandre; Vasconcelos, Vítor; Loureiro, Susana

2016-05-01

Microcystin-LR (MC-LR) and cylindrospermopsin (CYN) are the most representative cyanobacterial cyanotoxins. They have been simultaneously detected in aquatic systems, but their combined ecotoxicological effects to aquatic organisms, especially microalgae, is unknown. In this study, we examined the effects of these cyanotoxins individually and as a binary mixture on the growth rate of the freshwater algae Chlorella vulgaris. Using the MIXTOX tool, the reference model concentration addition (CA) was selected to evaluate the combined effects of MC-LR and CYN on the growth of the freshwater green algae due to its conservative prediction of mixture effect for putative similar or dissimilar acting chemicals. Deviations from the CA model such as synergism/antagonism, dose-ratio and dose-level dependency were also assessed. In single exposures, our results demonstrated that MC-LR and CYN had different impacts on the growth rates of C. vulgaris at the highest tested concentrations, being CYN the most toxic. In the mixture exposure trial, MC-LR and CYN showed a synergistic deviation from the conceptual model CA as the best descriptive model. MC-LR individually was not toxic even at high concentrations (37 mg L(-1)); however, the presence of MC-LR at much lower concentrations (0.4-16.7 mg L(-1)) increased the CYN toxicity. From these results, the combined exposure of MC-LR and CYN should be considered for risk assessment of mixtures as the toxicity may be underestimated when looking only at the single cyanotoxins and not their combination. This study also represents an important step to understand the interactions among MC-LR and CYN detected previously in aquatic systems.

ECO-ENTOMOLOGICAL OBSERVATIONS FROM THE AMAZON. IV. Occurrence and feeding habits of the aquatic caterpillar Palustra laboulbeni Bar, 1873 (Arctiidae: Lepidoptera) in the vicinity of Manaus, Brazil.

OpenAIRE

Adis, Joachim

1983-01-01

Abstract Aquatic larvae of Palustra laboulbeni Bar, 1873 are recorded for the first time from Brazil. They live among macrophytes in different types of lakes around Manaus and mostly feed on algae. Observations on their respiration are given. Resumo Larvas aquáticas de Palustra laboulbeni Bar. 1873 são referidas pela primeira vez no Brasil. Elas vivem entre macrófitas em diferentes tipos de lagos nas proximidades de Manaus e se alimentam principalmente de algas. Observações sobre a respira...

A generalized macro-assembler

International Nuclear Information System (INIS)

Kaul, Mohan Lai

1970-01-01

The objective of this research is to study existing macro assemblers, and to create a generalized macro assembler, MAG-I, which is a system independent of a source language, and provides the following possibilities: development of any existing language, translation from a language to another, and creation of a new language. The user can choose his own notations to define macros. The system is implemented on an IBM 360/91 computer. Programs are written in symbolic language and the input/output software is written in Fortran [fr

Assessing combined impacts of agrochemicals: Aquatic macroinvertebrate population responses in outdoor mesocosms.

Science.gov (United States)

Barmentlo, S Henrik; Schrama, Maarten; Hunting, Ellard R; Heutink, Roel; van Bodegom, Peter M; de Snoo, Geert R; Vijver, Martina G

2018-08-01

Agricultural ditches host a diverse community of species. These species often are unwarrantedly exposed to fertilizers and a wide-array of pesticides (hereafter: agrochemicals). Standardized ecotoxicological research provides valuable information to predict whether these pesticides possibly pose a threat to the organisms living within these ditches, in particular macro-invertebrates. However, knowledge on how mixtures of these agrochemicals affect macro-invertebrates under realistic abiotic conditions and with population and community complexity is mostly lacking. Therefore we examined here, using a full factorial design, the population responses of macroinvertebrate species assemblages exposed to environmentally relevant concentrations of three commonly used agrochemicals (for 35days) in an outdoor experiment. The agrochemicals selected were an insecticide (imidacloprid), herbicide (terbuthylazine) and nutrients (NPK), all having a widespread usage and often detected together in watersheds. Effects on species abundance and body length caused by binary mixture combinations could be described from single substance exposure. However, when agrochemicals were applied as tertiary mixtures, as they are commonly found in agricultural waters, species' abundance often deviated from expectations made based on the three single treatments. This indicates that pesticide-mixture induced toxicity to population relevant endpoints are difficult to extrapolate to field conditions. As in agricultural ditches often a multitude (approx. up to 7) of agrochemicals residues are detected, we call other scientist to verify the ecological complexity of non-additive induced shifts in natural aquatic invertebrate populations and aquatic species assemblages. Copyright © 2018 Elsevier B.V. All rights reserved.

The effects of a pesticide mixture on aquatic ecosystems differing in trophic status: responses of the macrophyte Myriophyllum spicatum and the periphytic algal community.

Science.gov (United States)

Wendt-Rasch, L; Van den Brink, P J; Crum, S J H; Woin, P

2004-03-01

The effects of a pesticide mixture (asulam, fluazinam, lambda-cyhalothrin, and metamitron) on aquatic ecosystems were investigated in 20 outdoor aquatic microcosms. Ten of the microcosms simulated mesotrophic aquatic ecosystems dominated by submerged macrophytes (Elodea). The others simulated eutrophic ecosystems with a high Lemna surface coverage (Lemna). This paper describes the fate of the chemicals as well as their effects on the growth of Myriophyllum spicatum and the periphytic algal community. In the Elodea-dominated microcosms significant increase in the biomass and alterations of species composition of the periphytic algae were observed, but no effect on M. spicatum growth could be recorded in response to the treatment. The opposite was found in the Lemna-dominated microcosms, in which decreased growth of M. spicatum was observed but no alterations could be found in the periphytic community. In the Elodea-dominated microcosms the species composition of the periphytic algae diverged from that of the control following treatment with 0.5% spray drift emission of the label-recommended rate (5% for lambda-cyhalothrin), while reduced growth of M. spicatum in the Lemna-dominated microcosms was recorded at 2% drift (20% for lambda-cyhalothrin). This study shows that the structure of the ecosystem influences the final effect of pesticide exposure.

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

International Nuclear Information System (INIS)

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

2000-01-01

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

Landscape level influence: aquatic primary production in the Colorado River of Glen and Grand canyons

Science.gov (United States)

Yard, M. D.; Kennedy, T.; Yackulic, C. B.; Bennett, G. E.

2012-12-01

Irregular features common to canyon-bound regions intercept solar incidence (photosynthetic photon flux density [PPFD: μmol m-2 s-1]) and can affect ecosystem energetics. The Colorado River in Grand Canyon is topographically complex, typical of most streams and rivers in the arid southwest. Dam-regulated systems like the Colorado River have reduced sediment loads, and consequently increased water transparency relative to unimpounded rivers; however, sediment supply from tributaries and flow regulation that affects erosion and subsequent sediment transport, interact to create spatial and temporal variation in optical conditions in this river network. Solar incidence and suspended sediment loads regulate the amount of underwater light available for aquatic photosynthesis in this regulated river. Since light availability is depth dependent (Beer's law), benthic algae is often exposed to varying levels of desiccation or reduced light conditions due to daily flow regulation, additional factors that further constrain aquatic primary production. Considerable evidence suggests that the Colorado River food web is now energetically dependent on autotrophic production, an unusual condition since large river foodwebs are typically supported by allochthonous carbon synthesized and transported from terrestrial environments. We developed a mechanistic model to account for these regulating factors to predict how primary production might be affected by observed and alternative flow regimes proposed as part of ongoing adaptive management experimentation. Inputs to our model include empirical data (suspended sediment and temperature), and predictive relationships: 1) solar incidence reaching the water surface (topographic complexity), 2) suspended sediment-light extinction relationships (optical properties), 3) unsteady flow routing model (stage-depth relationship), 4) channel morphology (photosynthetic area), and 5) photosynthetic-irradiant response for dominant algae (Cladophora

C.E.B.A.S., a closed equilibrated biological aquatic system as a possible precursor for a long-term life support system?

Science.gov (United States)

Blüm, V.

C.E.B.A.S.-AQUARACK is a long-term multi-generation experimental device for aquatic organisms which is disposed for utlizitation in a space station. It results from the basic idea of a space aquarium for maintaining aquatic animals for longer periods integrated in a AQUARACK which consists of a modular animal holding tank, a semi-biological/physical water recycling system and an electronical control unit. The basic idea to replace a part of the water recycling system by a continuous culture of unicellular algae primarily leads to a second system for experiments with algae, a botanical AQUARACK consisting of an algal reactor, a water recycling and the electronical control unit. The combination of the zoological part, and the botanical part with a common control system in the AQUARACK, however, results in a ``Closed Equilibrated Biological Aquatic System'' (C.E.B.A.S.) representing an closed artificial ecosystem. Although this is disposed primarily as an experimental device for basic zoological, botanical and interdisciplinary research it opens the theoretical possibility to adapt it for combined production of animal and plant biomass on ground or in space. The paper explains the basic conception of the hardware construction of the zoological part of the system, the corresponding scientific frame program including the choice of the experimental animals and gives some selected examples of the hardware-related resrearch. It furtheron discusses the practical and economical relevance of the system in the development of a controlled aquatical life support system in general.

Transgenic algae engineered for higher performance

Science.gov (United States)

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.

A floodplain mesocosm study: Distribution, mobility, aging, and functioning of engineered silver nanoparticles at the aquatic-terrestrial interface

Science.gov (United States)

Metreveli, George; Kurtz, Sandra; Philippe, Allan; Tayyebi, Narjes; Seitz, Frank; Rosenfeldt, Ricki R.; Grün, Alexandra; Kumahor, Samuel K.; Baumann, Thomas; Bundschuh, Mirco; Lang, Friederike; Klitzke, Sondra; Manz, Werner; Schulz, Ralf; Vogel, Hans-Jörg; Schaumann, Gabriele E.

2017-04-01

concentrations of silver applied in the experiment and limited dissolution of Ag NPs. Furthermore, extremely high enrichment factors of silver were determined for leaves (up to 11000) and algae (up to 30000) suggesting possible bioaccumulation of silver in aquatic organisms feeding on leaves and algae.

Harvesting, oil extraction, and conversion of local filamentous algae growing in wastewater into biodiesel

Energy Technology Data Exchange (ETDEWEB)

Grayburn, W.S.; Holbrook, G.P. [Department of Biological Sciences, Northern Illinois University, DeKalb, IL 60115 (United States); Tatara, R.A. [Department of Technology, Northern Illinois University, DeKalb, IL 60115 (United States); Rosentrater, K.A. [Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA 50011 (United States)

2013-07-01

Algae are known to be a potential feedstock in the production of biodiesel fuel. Although much of the focus has been on microalgal species, macroalgae are also suitable as a source of lipids. In this study, a locally abundant (central Illinois) filamentous algae has been harvested from a water treatment plant; dried to about 10% of its initial weight; pulverized in a hammermill; and treated with methanol to extract the oil. The algae are a combination of several coexisting species including Cladophora sp. and Rhizoclonium. Oil yields ranged from 3% to 6%, by weight, of the dried mass. This oil was reacted by transesterification to yield fatty acid methyl esters (biodiesel fuel) with an overall mass conversion efficiency of 68%. A B5 blend of this algal biodiesel and petrodiesel was run in a 13.4-kW test engine. Measurements indicated similar performance compared to pure petrodiesel in terms of fuel efficiency and carbon dioxide and carbon monoxide exhaust emissions. Significantly, there was a 22% reduction in nitrogen oxides when using the B5 fuel. It has been demonstrated that filamentous macroalgae may be cultivated as biodiesel feedstock and have inherent advantages such as an ability to remove phosphorus and nitrogen compounds from wastewater, simplicity of harvesting, and natural resistance to local aquatic grazers and competing organisms.

A review of ecological effects and environmental fate of illicit drugs in aquatic ecosystems.

Science.gov (United States)

Rosi-Marshall, E J; Snow, D; Bartelt-Hunt, S L; Paspalof, A; Tank, J L

2015-01-23

Although illicit drugs are detected in surface waters throughout the world, their environmental fate and ecological effects are not well understood. Many illicit drugs and their breakdown products have been detected in surface waters and temporal and spatial variability in use translates into "hot spots and hot moments" of occurrence. Illicit drug occurrence in regions of production and use and areas with insufficient wastewater treatment are not well studied and should be targeted for further study. Evidence suggests that illicit drugs may not be persistent, as their half-lives are relatively short, but may exhibit "pseudo-persistence" wherein continual use results in persistent occurrence. We reviewed the literature on the ecological effects of these compounds on aquatic organisms and although research is limited, a wide array of aquatic organisms, including bacteria, algae, invertebrates, and fishes, have receptors that make them potentially sensitive to these compounds. In summary, illicit drugs occur in surface waters and aquatic organisms may be affected by these compounds; research is needed that focuses on concentrations of illicit drugs in areas of production and high use, environmental fate of these compounds, and effects of these compounds on aquatic ecosystems at the concentrations that typically occur in the environment. Copyright © 2014 Elsevier B.V. All rights reserved.

Integrated assessment of river health based on the conditions of water quality,aquatic life and physical habitat

Institute of Scientific and Technical Information of China (English)

MENG Wei; ZHANG Nan; ZHANG Yuan; ZHENG Binghui

2009-01-01

The health conditions of Liao River were assessed using 25 sampling sites in April 2005, with water quality index, biotic index and physical habitat quality index.Based on the method of cluster analysis (CA) for water quality indices, it reveals that heavily polluted sites of Liao River are located at estuary and mainstream.The aquatic species surveyed were attached algae and benthic invertebrates.The result shows that the diversity and biomass of attached algae and benthic index of biotic integrity (B-IBI) are degrading as the chemical and physical quality of water bodies deteriorating.Physiochemical parameters, BOD5, CODCr, TN, TP, NH3-N, DO, petroleum hydrocarbon and conductivity, were statistically analyzed with principal component analysis and correlation analysis.The statistical results were incorporated into the integrated assessing water quality index, combining fecal coliform count, attached algae diversity, B-IBI and physical habitat quality score, a comprehensive integrated assessing system of river ecological health was established.Based on the systimetic assesment, the assessed sites are categorized into 9 "healthy" and "sub-healthy" sites and 8 "sub-sick" and "sick" sites.

Macro-economic environmental models

International Nuclear Information System (INIS)

Wier, M.

1993-01-01

In the present report, an introduction to macro-economic environmental models is given. The role of the models as a tool for policy analysis is discussed. Future applications, as well as the limitations given by the data, are brought into focus. The economic-ecological system is described. A set of guidelines for implementation of the system in a traditional economic macro-model is proposed. The characteristics of empirical national and international environmental macro-economic models so far are highlighted. Special attention is paid to main economic causalities and their consequences for the environmental policy recommendations sat by the models. (au) (41 refs.)

Magnetic separation of algae

Science.gov (United States)

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.

ZEUS - standardized macros for the TPA computer

International Nuclear Information System (INIS)

Winde, M.

1976-01-01

An existing cross-assembler with macro-option was modified to allow the usage of the ZEUS macros. The ZEUS macros are understood by the assembler without prior definition by the user. ZEUS macros allow the programmer, who is obliged to code his TPA (PDP-8) programs on the assembler level to formulate his program logic as in a higher level language. ZEUS macros offer all basic elements necessary for structured programming. (author)

The energetic contributions of aquatic primary producers to terrestrial food webs in a mid-size river system.

Science.gov (United States)

Kautza, Adam; Mazeika, S; Sullivan, P

2016-03-01

Rivers are increasingly recognized as providing nutritional subsidies (i.e., energy and nutrients) to adjacent terrestrial food webs via depredation of aquatic organisms (e.g., emergent aquatic insects, crayfish, fish) by terrestrial consumers. However, because these prey organisms assimilate energy from both aquatic (e.g., benthic algae, phytoplankton, aquatic macrophytes) and terrestrial (e.g., riparian leaf detritus) primary producers, river subsidies to terrestrial consumers represent a combination of aquatically and terrestrially derived energy. To date, the explicit contribution of energy derived from aquatic primary producers to terrestrial consumers has not been fully explored yet might be expected to be quantitatively important to terrestrial food webs. At 12 reaches along a 185-km segment of the sixth-order Scioto River system (Ohio, USA), we quantified the relative contribution of energy derived from aquatic primary producers to a suite of terrestrial riparian consumers that integrate the adjacent landscape across multiple spatial scales through their foraging activities (tetragnathid spiders, rove beetles, adult coenagrionid damselflies, riparian swallows, and raccoons). We used naturally abundant stable isotopes (13C and 15N) of periphyton, phytoplankton, macrophytes, and terrestrial vegetation to evaluate the energetic contribution of aquatic primary producers to terrestrial food webs. Shoreline tetragnathid spiders were most reliant on aquatic primary producers (50%), followed by wider-ranging raccoons (48%), damselflies (44%), and riparian swallows (41%). Of the primary producers, phytoplankton (19%) provisioned the greatest nutritional contribution to terrestrial consumers (considered collectively), followed by periphyton (14%) and macrophytes (11%). Our findings provide empirical evidence that aquatic primary producers of large streams and rivers can be a critical nutritional resource for terrestrial food webs. We also show that aquatically

Fate of ethinylestradiol in the aquatic environment and the associated effects on organisms of different trophic levels

OpenAIRE

Maes, Hanna

2011-01-01

The accumulation kinetics of an important, highly effective, and persistent xeno-estrogen, 17alpha-ethinylestradiol (EE2), in the aquatic environment were investigated in indicator species representing the different trophic levels of an ecosystem: a primary producer (Desmodesmus suspicatus), a primary consumer of the water phase (Daphnia magna) and one of the sediment (Chironomus riparius), and a secondary consumer (Danio rerio). Algae highly concentrated 14C-EE2 (72 h Calgae/Cwater: 2200 L/k...

Macro-Fiber Composite Based Transduction

Science.gov (United States)

2016-03-01

substrate Material properties of single crystal macro fiber composite actuators for active twist rotor blades Park, Jae-Sang (Seoul National...Passive Smart Structures and Integrated Systems 2007 Material properties of single crystal macro fiber composite actuators for active twist rotor ...19b. TELEPHONE NUMBER (Include area code) 10-03-20 16 Final Report 01 Jan 2013 - 31 Dec 2015 Macro-Fiber Composite Based Transduction N000-14-13-1-0212

Incorporation of tritium into planctonic algae in a continuous culture under dynamic conditions

International Nuclear Information System (INIS)

Strack, S.; Kistner, G.; Emeis, C.C.

1979-01-01

For the purpose of modelling the ecologic behaviour of organically bound tritium (OBT) in aquatic food chains under dynamic conditions (i.e. by changing tritium concentrations), a continuous culture of algae was chosen to which tritium was added by a single injection as tritiated water (HTO). The culture was working according to the chemostatic principle where the concentration of cells is in a steady state. Therefore, according to the growth of algae, tritium is incorporated into the organic substance, while in a parallel process HTO and algae are eliminated from the system at the same rate. From these two processes of first-order kinetics, a special function resulted for the concentration process of OBT in the fermenter that is well known in the field of drug kinetics. Initially it increases until it reaches a maximum value where it intersects the elimination curve of HTO, then decreases and asymptotically approaches the time axis - in the same manner as the elimination curve - only at a superior level. A comparison of this theoretically calculated function with the concentration actually found shows that also under dynamic conditions tritium is undergoing discrimination because of isotopic effects up to a ratio of I=0.80. The calculation of the ratios R=(OBT)/(HTO) in the continuous culture by comparing the function for OBT with the elimination curve for HTO shows a linear increase of R-values during the experiment. At maximum tritium concentration in the algae, the ratio becomes greater than one, and at the end of the experiment it reaches a value of about 6. However, by extrapolating to a time of 40 half-lives, when the absolute concentration of HTO has already decreased by a factor of 10 -12 , a ratio of about 25 was found. The discrimination enters the estimation of R-values at a constant factor of 0.80. (author)

Antioxidant Potential of Extracts Obtained from Macro- (Ascophyllum nodosum, Fucus vesiculosus and Bifurcaria bifurcata and Micro-Algae (Chlorella vulgaris and Spirulina platensis Assisted by Ultrasound

Directory of Open Access Journals (Sweden)

Rubén Agregán

2018-04-01

Full Text Available Background: Natural antioxidants, which can replace synthetic ones due to their potential implications for health problems in children, have gained significant popularity. Therefore, the antioxidant potential of extracts obtained from three brown macroalgae (Ascophyllum nodosum, Fucus vesiculosus and Bifurcaria bifurcata and two microalgae (Chlorella vulgaris and Spirulina platensis using ultrasound-extraction as an innovative and green approach was evaluated. Methods: Algal extracts were obtained by ultrasound-assisted extraction using water/ethanol (50:50, v:v as the extraction solvent. The different extracts were compared based on their antioxidant potential, measuring the extraction yield, the total phenolic content (TPC and the antioxidant activity. Results: Extracts from Ascophyllum nodosum (AN and Bifurcaria bifurcata (BB showed the highest antioxidant potential compared to the rest of the samples. In particular, BB extract presented the highest extraction (35.85 g extract/100 g dry weight (DW and total phenolic compounds (TPC (5.74 g phloroglucinol equivalents (PGE/100 g DW yields. Regarding the antioxidant activity, macroalgae showed again higher values than microalgae. BB extract had the highest antioxidant activity in the ORAC, DPPH and FRAP assays, with 556.20, 144.65 and 66.50 µmol Trolox equivalents (TE/g DW, respectively. In addition, a correlation among the antioxidant activity and the TPC was noted. Conclusions: Within the obtained extracts, macroalgae, and in particular BB, are more suitable to be used as sources of phenolic antioxidants to be included in products for human consumption. The relatively low antioxidant potential, in terms of polyphenols, of the microalgae extracts studied in the present work makes them useless for possible industrial applications compared to macroalgae, although further in vivo studies evaluating the real impact of antioxidants from both macro- and micro-algae at the cellular level should be

Dynamic model for tritium transfer in an aquatic food chain.

Science.gov (United States)

Melintescu, A; Galeriu, D

2011-08-01

Tritium ((3)H) is released from some nuclear facilities in relatively large quantities. It is a ubiquitous isotope because it enters straight into organisms, behaving essentially identically to its stable analogue (hydrogen). Tritium is a key radionuclide in the aquatic environment, in some cases, contributing significantly to the doses received by aquatic, non-human biota and by humans. The updated model presented here is based on more standardized, comprehensive assessments than previously used for the aquatic food chain, including the benthic flora and fauna, with an explicit application to the Danube ecosystem, as well as an extension to the special case of dissolved organic tritium (DOT). The model predicts the organically bound tritium (OBT) in the primary producers (the autotrophs, such as phytoplankton and algae) and in the consumers (the heterotrophs) using their bioenergetics, which involves the investigation of energy expenditure, losses, gains and efficiencies of transformations in the body. The model described in the present study intends to be more specific than a screening-level model, by including a metabolic approach and a description of the direct uptake of DOT in marine phytoplankton and invertebrates. For a better control of tritium transfer into the environment, not only tritiated water must be monitored, but also the other chemical forms and most importantly OBT, in the food chain.

Algae Resources

Energy Technology Data Exchange (ETDEWEB)

None

2016-06-01

Algae are highly efficient at producing biomass, and they can be found all over the planet. Many use sunlight and nutrients to create biomass, which contain key components—including lipids, proteins, and carbohydrates— that can be converted and upgraded to a variety of biofuels and products. A functional algal biofuels production system requires resources such as suitable land and climate, sustainable management of water resources, a supplemental carbon dioxide (CO2) supply, and other nutrients (e.g., nitrogen and phosphorus). Algae can be an attractive feedstock for many locations in the United States because their diversity allows for highpotential biomass yields in a variety of climates and environments. Depending on the strain, algae can grow by using fresh, saline, or brackish water from surface water sources, groundwater, or seawater. Additionally, they can grow in water from second-use sources such as treated industrial wastewater; municipal, agricultural, or aquaculture wastewater; or produced water generated from oil and gas drilling operations.

Acute toxicity of anionic and non-ionic surfactants to aquatic organisms.

Science.gov (United States)

Lechuga, M; Fernández-Serrano, M; Jurado, E; Núñez-Olea, J; Ríos, F

2016-03-01

The environmental risk of surfactants requires toxicity measurements. As different test organisms have different sensitivity to the toxics, it is necessary to establish the most appropriate organism to classify the surfactant as very toxic, toxic, harmful or safe, in order to establish the maximum permissible concentrations in aquatic ecosystems. We have determined the toxicity values of various anionic surfactants ether carboxylic derivatives using four test organisms: the freshwater crustacean Daphnia magna, the luminescent bacterium Vibrio fischeri, the microalgae Selenastrum capricornutum (freshwater algae) and Phaeodactylum tricornutum (seawater algae). In addition, in order to compare and classify the different families of surfactants, we have included a compilation of toxicity data of surfactants collected from literature. The results indicated that V. fischeri was more sensitive to the toxic effects of the surfactants than was D. magna or the microalgae, which was the least sensitive. This result shows that the most suitable toxicity assay for surfactants may be the one using V. fischeri. The toxicity data revealed considerable variation in toxicity responses with the structure of the surfactants regardless of the species tested. The toxicity data have been related to the structure of the surfactants, giving a mathematical relationship that helps to predict the toxic potential of a surfactant from its structure. Model-predicted toxicity agreed well with toxicity values reported in the literature for several surfactants previously studied. Predictive models of toxicity is a handy tool for providing a risk assessment that can be useful to establish the toxicity range for each surfactant and the different test organisms in order to select efficient surfactants with a lower impact on the aquatic environment. Copyright © 2015 Elsevier Inc. All rights reserved.

Algae-production in the desert

Energy Technology Data Exchange (ETDEWEB)

Hildebrand, H.

1988-11-01

The company Koor Food Ltd. (Israel) developed in co-operation with the Weizmann-Institute (Israel) a production-plant for the industrial cultivation of algae in the desert area of Elat. For almost a year now, they succeed in harvesting large amounts of algae material with the help of the intensive sun and the Red Sea water. The alga Dunaliella with the natural US -carotine, as well as the alga Spirulina with the high content of protein find their market in the food-, cosmetic- and pharma-industry. This article will give a survey of a yet here unusual project.

Is litter decomposition 'primed' by primary producer-release of labile carbon in terrestrial and aquatic experimental systems?

Science.gov (United States)

Soares, A. Margarida P. M.; Kritzberg, Emma S.; Rousk, Johannes

2015-04-01

It is possible that recalcitrant organic matter (ROM) can be 'activated' by inputs of labile organic matter (LOM) through the priming effect (PE). Investigating the PE is of major importance to fully understand the microbial use of ROM and its role on carbon (C) and nutrient cycling in both aquatic and terrestrial ecosystems. In aquatic ecosystems it is thought that the PE is triggered by periphytic algae release of LOM. Analogously, in terrestrial systems it is hypothesized that the LOM released in plant rhizospheres, or from the green crusts on the surface of agricultural soils, stimulate the activity and growth of ROM decomposers. Most previous studies on PE have utilised pulse additions of single substrates at high concentrations. However, to achieve an assessment of the true importance of the PE, it is important to simulate a realistic delivery of LOM. We investigated, in a series of 2-week laboratory experiments, how primary producer (PP)-release of LOM influence litter degradation in terrestrial and aquatic experimental systems. We used soil (terrestrial) and pond water (aquatic) microbial communities to which litter was added under light and dark conditions. In addition, glucose was added at PP delivery rates in dark treatments to test if the putative PE in light systems could be reproduced. We observed an initial peak of bacterial growth rate followed by an overall decrease over time with no treatment differences. In light treatments, periphytic algae growth and increased fungal production was stimulated when bacterial growth declined. In contrast, both fungal growth and algal production were negligible in dark treatments. This reveals a direct positive influence of photosynthesis on fungal growth. To investigate if PP LOM supplements, and the associated fungal growth, translate into a modulated litter decomposition, we are using stable isotopes to track the use of litter and algal-derived carbon by determining the δ13C in produced CO2. Fungi and bacteria

Why Macro Practice Matters

Science.gov (United States)

Reisch, Michael

2016-01-01

This article asserts that macro practice is increasingly important in today's rapidly changing and complex practice environment. It briefly explores the history of macro practice in U.S. social work, summarizes its major contributions to the profession and to U.S. society, and provides some suggestions for how social work programs can expand…

Spreadsheet macros for coloring sequence alignments.

Science.gov (United States)

Haygood, M G

1993-12-01

This article describes a set of Microsoft Excel macros designed to color amino acid and nucleotide sequence alignments for review and preparation of visual aids. The colored alignments can then be modified to emphasize features of interest. Procedures for importing and coloring sequences are described. The macro file adds a new menu to the menu bar containing sequence-related commands to enable users unfamiliar with Excel to use the macros more readily. The macros were designed for use with Macintosh computers but will also run with the DOS version of Excel.

Algae commensal community in Genlisea traps

Directory of Open Access Journals (Sweden)

Konrad Wołowski

2011-01-01

Full Text Available The community of algae occurring in Genlisea traps and on the external traps surface in laboratory conditions were studied. A total of 29 taxa were found inside the traps, with abundant diatoms, green algae (Chlamydophyceae and four morphotypes of chrysophytes stomatocysts. One morphotype is described as new for science. There are two ways of algae getting into Genlisea traps. The majority of those recorded inside the traps, are mobile; swimming freely by flagella or moving exuding mucilage like diatoms being ablate to colonize the traps themselves. Another possibility is transport of algae by invertebrates such as mites and crustaceans. In any case algae in the Genlisea traps come from the surrounding environment. Two dominant groups of algae (Chladymonas div. and diatoms in the trap environment, show ability to hydrolyze phosphomonoseters. We suggest that algae in carnivorous plant traps can compete with plant (host for organic phosphate (phosphomonoseters. From the spectrum and ecological requirements of algal species found in the traps, environment inside the traps seems to be acidic. However, further studies are needed to test the relations between algae and carnivorous plants both in laboratory conditions and in the natural environment. All the reported taxa are described briefly and documented with 74 LM and SEM micrographs.

Joint Macro and Femto Field Performance and Interference Measurements

DEFF Research Database (Denmark)

Jørgensen, Niels T.K.; Isotalo, Tero; Pedersen, Klaus

2012-01-01

In this paper macro performance in a co-channel macro and femto setup is studied. Measurements are performed in a live Universal Mobile Telecommunication System (UMTS) network. It is concluded that femto interference does not affect macro downlink (DL) performance as long as the macro Received Si...... radius smaller than 5 meter – with realistic power settings. This makes co-channel femto deployment less promising in dense macro environments with good macro RSCP coverage.......In this paper macro performance in a co-channel macro and femto setup is studied. Measurements are performed in a live Universal Mobile Telecommunication System (UMTS) network. It is concluded that femto interference does not affect macro downlink (DL) performance as long as the macro Received...... Signal Code Power (RSCP) is stronger than femto RSCP. We also conclude that a macro escape carrier is a robust DL interference management solution. In uplink (UL) direction it is shown that a single femto UE close to macro cell potentially can cause a noise rise of 6 dB in the surrounding macro cell...

Seaweed Bioactive Compounds against Pathogens and Microalgae: Potential Uses on Pharmacology and Harmful Algae Bloom Control.

Science.gov (United States)

Zerrifi, Soukaina El Amrani; El Khalloufi, Fatima; Oudra, Brahim; Vasconcelos, Vitor

2018-02-09

Cyanobacteria are found globally due to their adaptation to various environments. The occurrence of cyanobacterial blooms is not a new phenomenon. The bloom-forming and toxin-producing species have been a persistent nuisance all over the world over the last decades. Evidence suggests that this trend might be attributed to a complex interplay of direct and indirect anthropogenic influences. To control cyanobacterial blooms, various strategies, including physical, chemical, and biological methods have been proposed. Nevertheless, the use of those strategies is usually not effective. The isolation of natural compounds from many aquatic and terrestrial plants and seaweeds has become an alternative approach for controlling harmful algae in aquatic systems. Seaweeds have received attention from scientists because of their bioactive compounds with antibacterial, antifungal, anti-microalgae, and antioxidant properties. The undesirable effects of cyanobacteria proliferations and potential control methods are here reviewed, focusing on the use of potent bioactive compounds, isolated from seaweeds, against microalgae and cyanobacteria growth.

Assessment of macro and microelement accumulation capability of two aquatic plants

International Nuclear Information System (INIS)

Baldantoni, Daniela; Alfani, Anna; Di Tommasi, Paul; Bartoli, Giovanni; De Santo, Amalia Virzo

2004-01-01

The concentrations of four macroelements (C, N, P, S) and eight trace metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn) were measured in the leaves and roots of the emergent plant, Phragmites communis Trin., and in the shoots and roots of the submersed Najas marina L., taken from Lake Averno (Naples, Italy). Phragmites communis leaves showed higher concentrations of carbon, nitrogen and phosphorus than roots, while the roots exhibited significantly higher concentrations of sulphur and trace metals. Najas marina roots also showed higher concentrations of sulphur and trace metals than shoots, but these differences were less marked than in Phragmites communis except for sulphur. Sulphur was the only macronutrient to show the highest concentrations in the roots. Phragmites communis roots had higher values of Cr, Cu, Fe, Mn and Ni than Najas marina roots. By contrast, Cd, Cr, Fe, Ni, Pb and Zn concentrations were higher in Najas marina shoots than in Phragmites communis leaves. Phragmites communis, available through the year, showing high capability to accumulate trace metals in the roots, appears a good monitor of lake contamination, better than Najas marina. - Element accumulation in roots and shoots of aquatic plants was used as a criteria for selecting useful biomonitors

Using Stable Isotopes to Detect Land Use Change and Nitrogen Sources in Aquatic Systems

Energy Technology Data Exchange (ETDEWEB)

Rogers, K. M. [National Isotope Center, GNS Science, Lower Hutt (New Zealand)

2013-05-15

Changing land use is one of the primary causes of increased sedimentation and nutrient levels in aquatic systems, resulting in contamination and reduction of biodiversity. Detecting and quantifying these inputs is the first step towards remediation, and enabling targeted reductions of transport processes into waterways from human impacted land surfaces. More recently, stable isotope analyses are being used as detection and quantification tools in aquatic environments. Carbon ({delta}{sup 13}C) and nitrogen ({delta}{sup 15}N) isotopes of sediments, as well as algae and invertebrates from aquatic systems can be used as proxies to record both short and long term environmental change. Excess nitrogen (or nitrogen-compounds) derived from urbanization, industry, forestry, farming and agriculture, increase the bioavailability of nitrogen to aquatic organisms, changing their natural {delta}15N isotopic signatures. Allochthonous (terrestrial) input from soil destabilization and human activity in surrounding catchments changes {delta}{sup 13}C isotopic compositions and increases the C:N ratio of sediments. Heavy metal and other organic pollutants can also be used to indicate urbanization and industrial contamination. The combined use of carbon and nitrogen isotopes, C:N ratios and heavy metals are powerful environmental monitoring tools, which are useful indicators of source and transport pathways of terrestrial derived material and anthropogenic pollutants into streams, rivers and estuaries. (author)

Algae

Czech Academy of Sciences Publication Activity Database

Raven, John A.; Giordano, Mario

2014-01-01

Roč. 24, č. 13 (2014), s. 590-595 ISSN 0960-9822 Institutional support: RVO:61388971 Keywords : algae * life cycle * evolution Subject RIV: EE - Microbiology, Virology Impact factor: 9.571, year: 2014

Research regarding the changes that occur in the structure of benthic macro invertebrates communities as a result of anthropogenic activities

Directory of Open Access Journals (Sweden)

Anca-Andreea Marin

2016-05-01

Full Text Available An important role in the monitoring of the water quality is represented by the benthic macro invertebrates. They are a key component in the transfer of matter and energy in the aquatic ecosystems. In May 2015, 20 quantitative samples of benthic sample were collected at different seasons in the Bega River water. Samples were collected from the upstream, middle and downstream of Timisoara city. The aim of this paper is to identify the changes that occur in the structure of benthic macro invertebrates communities due to anthropogenic activities. Once the identification of  saprobionte organisms has done, it have been performed the density, abundance and frequency of the sample. Based on these values, we can say that the upstream segment waters falls into the category of superior quality compared to the waters of the central segment, especially in the downstream segment.

Electro-coagulation-flotation process for algae removal

International Nuclear Information System (INIS)

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

2010-01-01

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 deg. 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.

Imaging Spectrometry of Inland and Coastal Waters: State of the Art, Achievements and Perspectives

Science.gov (United States)

Giardino, C.; Brando, V. E.; Gege, P.; Pinnel, N.; Hochberg, E.; Knaeps, E.; Reusen, I.; Doerffer, R.; Bresciani, M.; Braga, F.; Foerster, S.; Champollion, N.; Dekker, A.

2018-06-01

Imaging spectrometry of non-oceanic aquatic ecosystems has been in development since the late 1980s when the first airborne hyperspectral sensors were deployed over lakes. Most water quality management applications were, however, developed using multispectral mid-spatial resolution satellites or coarse spatial resolution ocean colour satellites till now. This situation is about to change with a suite of upcoming imaging spectrometers being deployed from experimental satellites or from the International Space Station. We review the science of developing applications for inland and coastal aquatic ecosystems that often are a mixture of optically shallow and optically deep waters, with gradients of clear to turbid and oligotrophic to hypertrophic productive waters and with varying bottom visibility with and without macrophytes, macro-algae, benthic micro-algae or corals. As the spaceborne, airborne and in situ optical sensors become increasingly available and appropriate for aquatic ecosystem detection, monitoring and assessment, the science-based applications will need to be further developed to an operational level. The Earth Observation-derived information products will range from more accurate estimates of turbidity and transparency measures, chlorophyll, suspended matter and coloured dissolved organic matter concentration, to more sophisticated products such as particle size distributions, phytoplankton functional types or distinguishing sources of suspended and coloured dissolved matter, estimating water depth and mapping types of heterogeneous substrates. We provide an overview of past science, current state of the art and future directions so that early career scientists as well as aquatic ecosystem managers and associated industry groups may be prepared for the imminent deluge of imaging spectrometry data.

21 CFR 73.275 - Dried algae meal.

Science.gov (United States)

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 broth...

Recursive macro generator for the TAS-86 language. First part: the macro generator language. Second part: system internal logics

International Nuclear Information System (INIS)

Zraick, Samir

1970-01-01

A macro-generator is a translator which is able to interpret and translate a programme written in a macro-language. After a first part presenting the main notions and proposing a brief description of the TAS-86 language, the second part of this research thesis reports the development of the macro-generator language, and notably presents the additional functionalities provided by the macro generator. The development is illustrated by logical flowcharts and programming listings

Red algae and their use in papermaking.

Science.gov (United States)

Seo, Yung-Bum; Lee, Youn-Woo; Lee, Chun-Han; You, Hack-Chul

2010-04-01

Gelidialian red algae, that contain rhizoidal filaments, except the family Gelidiellaceae were processed to make bleached pulps, which can be used as raw materials for papermaking. Red algae consist of rhizoidal filaments, cortical cells usually reddish in color, and medullary cells filled with mucilaginous carbohydrates. Red algae pulp consists of mostly rhizoidal filaments. Red algae pulp of high brightness can be produced by extracting mucilaginous carbohydrates after heating the algae in an aqueous medium and subsequently treating the extracted with bleaching chemicals. In this study, we prepared paper samples from bleached pulps obtained from two red algae species (Gelidium amansii and Gelidium corneum) and compared their properties to those of bleached wood chemical pulps. Copyright 2009 Elsevier Ltd. All rights reserved.

Algae-Based Carbon Sequestration

Science.gov (United States)

Haoyang, Cai

2018-03-01

Our civilization is facing a series of environmental problems, including global warming and climate change, which are caused by the accumulation of green house gases in the atmosphere. This article will briefly analyze the current global warming problem and propose a method that we apply algae cultivation to absorb carbon and use shellfish to sequestrate it. Despite the importance of decreasing CO2 emissions or developing carbon-free energy sources, carbon sequestration should be a key issue, since the amount of carbon dioxide that already exists in the atmosphere is great enough to cause global warming. Algae cultivation would be a good choice because they have high metabolism rates and provides shellfish with abundant food that contains carbon. Shellfish’s shells, which are difficult to be decomposed, are reliable storage of carbon, compared to dead organisms like trees and algae. The amount of carbon that can be sequestrated by shellfish is considerable. However, the sequestrating rate of algae and shellfish is not high enough to affect the global climate. Research on algae and shellfish cultivation, including gene technology that aims to create “super plants” and “super shellfish”, is decisive to the solution. Perhaps the baton of history will shift to gene technology, from nuclear physics that has lost appropriate international environment after the end of the Cold War. Gene technology is vital to human survival.

Acute aquatic toxicity of tire and road wear particles to alga, daphnid, and fish.

Science.gov (United States)

Marwood, Christopher; McAtee, Britt; Kreider, Marisa; Ogle, R Scott; Finley, Brent; Sweet, Len; Panko, Julie

2011-11-01

Previous studies have indicated that tire tread particles are toxic to aquatic species, but few studies have evaluated the toxicity of such particles using sediment, the likely reservoir of tire wear particles in the environment. In this study, the acute toxicity of tire and road wear particles (TRWP) was assessed in Pseudokirchneriella subcapita, Daphnia magna, and Pimephales promelas using a sediment elutriate (100, 500, 1000 or 10000 mg/l TRWP). Under standard test temperature conditions, no concentration response was observed and EC/LC(50) values were greater than 10,000 mg/l. Additional tests using D. magna were performed both with and without sediment in elutriates collected under heated conditions designed to promote the release of chemicals from the rubber matrix to understand what environmental factors may influence the toxicity of TRWP. Toxicity was only observed for elutriates generated from TRWP leached under high-temperature conditions and the lowest EC/LC(50) value was 5,000 mg/l. In an effort to identify potential toxic chemical constituent(s) in the heated leachates, toxicity identification evaluation (TIE) studies and chemical analysis of the leachate were conducted. The TIE coupled with chemical analysis (liquid chromatography/mass spectrometry/mass spectrometry [LC/MS/MS] and inductively coupled plasma/mass spectrometry [ICP/MS]) of the leachate identified zinc and aniline as candidate toxicants. However, based on the high EC/LC(50) values and the limited conditions under which toxicity was observed, TRWP should be considered a low risk to aquatic ecosystems under acute exposure scenarios.

Potential biomedical applications of marine algae.

Science.gov (United States)

Wang, Hui-Min David; Li, Xiao-Chun; Lee, Duu-Jong; Chang, Jo-Shu

2017-11-01

Functional components extracted from algal biomass are widely used as dietary and health supplements with a variety of applications in food science and technology. In contrast, the applications of algae in dermal-related products have received much less attention, despite that algae also possess high potential for the uses in anti-infection, anti-aging, skin-whitening, and skin tumor treatments. This review, therefore, focuses on integrating studies on algae pertinent to human skin care, health and therapy. The active compounds in algae related to human skin treatments are mentioned and the possible mechanisms involved are described. The main purpose of this review is to identify serviceable algae functions in skin treatments to facilitate practical applications in this high-potential area. Copyright © 2017 Elsevier Ltd. All rights reserved.

Data set for extraction and transesterification of bio-oil from Stoechospermum marginatum, a brown marine algae.

Science.gov (United States)

Venkatesan, Hariram; Godwin, John J; Sivamani, Seralathan

2017-10-01

The article presents the experimental data on the extraction and transesterification of bio-oil derived from Stoechospermum marginatum, a brown macro marine algae. The samples were collected from Mandapam region, Gulf of Mannar, Tamil Nadu, India. The bio-oil was extracted using Soxhlet technique with a lipid extraction efficiency of 24.4%. Single stage transesterification was adopted due to lower free fatty acid content. The yield of biodiesel was optimized by varying the process parameters. The obtained data showed the optimum process parameters as reaction time 90 min, reaction temperature 65 °C, catalyst concentration 0.50 g and 8:1 M ratio. Furthermore, the data pertaining to the physio-chemical properties of the derived algal biodiesel were also presented.

Data set for extraction and transesterification of bio-oil from Stoechospermum marginatum, a brown marine algae

Directory of Open Access Journals (Sweden)

Hariram Venkatesan

2017-10-01

Full Text Available The article presents the experimental data on the extraction and transesterification of bio-oil derived from Stoechospermum marginatum, a brown macro marine algae. The samples were collected from Mandapam region, Gulf of Mannar, Tamil Nadu, India. The bio-oil was extracted using Soxhlet technique with a lipid extraction efficiency of 24.4%. Single stage transesterification was adopted due to lower free fatty acid content. The yield of biodiesel was optimized by varying the process parameters. The obtained data showed the optimum process parameters as reaction time 90 min, reaction temperature 65 °C, catalyst concentration 0.50 g and 8:1 M ratio. Furthermore, the data pertaining to the physio-chemical properties of the derived algal biodiesel were also presented.

Cultivation of macroscopic marine algae and freshwater aquatic weeds. Progress report, May 1--December 31, 1976

Energy Technology Data Exchange (ETDEWEB)

Ryther, J. H.

1977-01-01

Research was divided between basic physiological studies of the growth and nutrient-uptake kinetics of macroscopic marine algae and the more applied problems involved in the selection of species and the development of inexpensive, non-energy intensive culture methods for growing seaweeds and freshwater plants as a biomass source for conversion to energy. Best growth of the seaweeds occurs at low (0.1 to 1.0 ..mu..molar) concentration of major nutrients, with ammonia as a nitrogen source, with rapid exchange of the culture medium (residence time of 0.05 days or less). Of 43 species of seaweeds evaluated, representatives of the large red alga genus Gracilaria appear most promising with potential yields, in a highly intensive culture system under optimal conditions, of some 129 metric dry tons per hectare per year (about half of which is organic). Non-intensive culture methods have yielded one-third to one-half that figure. Unexplained periodicity of growth and overgrowth by epiphytes remain the most critical constraint to large-scale seaweed culture. Freshwater weed species in culture include water hyacinth (Eichhornia crassipes), duckweed (Lemna minor), and Hydrilla vertecillata, with yields to date averaging 15, 4, and 8 g dry wt/m/sup 2//day, respectively. However, these plants have not yet been grown through the winter, so average annual yields are expected to be lower. In contrast to the seaweeds, the freshwater plants grow well at high nutrient concentrations and slow culture volume exchange rates (residence time ca. 20 days or more). Experiments were initiated on the recycling of digester residues from the fermentation of the freshwater and marine plants as a possible nutrient source for growth of the same species.

Accumulation of polycyclic arenes in Baltic Sea algae

Energy Technology Data Exchange (ETDEWEB)

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 Kaesmu and green algae Cladophora or Enteromorpha in the eastern part of the Finnish Gulf.

Impact of environmental manipulation for Anopheles pseudopunctipennis Theobald control on aquatic insect communities in southern Mexico.

Science.gov (United States)

Bond, J G; Quiroz-Martínez, H; Rojas, J C; Valle, J; Ulloa, A; Williams, T

2007-06-01

Extraction of filamentous algae from river pools is highly effective for the control of Anophelespseudopunctipennis in southern Mexico. We determined the magnitude of changes to the aquatic insect community following single annual perturbations performed over two years. In 2001, algae were manually removed from all the pools in a 3 km long section of the River Coatán, Mexico, while an adjacent section was left as an untreated control. In 2002, the treatments of both zones were switched and algal extraction was repeated. The abundance of An. pseudopunctipennis larvae + pupae was dramatically reduced by this treatment and remained depressed for two to three months. A total of 11,922 aquatic insects from ten orders, 40 families, and 95 genera were collected in monthly samples taken over five months of each year. Algal extraction did not reduce the overall abundance of aquatic insects in river pools, but a greater abundance and a greater richness of taxa were observed in 2002 compared to the previous year. This was associated with reduced precipitation and river discharge in 2002 compared to 2001. Shannon diversity index values were significantly depressed following algal extraction for a period of three months, in both years, before returning to values similar to those of the control zone. However, differences between years were greater than differences between treatments within a particular year. When insects were classified by functional feeding group (FFG), no significant differences were detected in FFG densities between extraction and control zones over time in either year of the study. Similarly, percent model affinity index values were classified as "not impacted" by the extraction process. Discriminant function analysis identified two orders of insects (Diptera and Odonata), water temperature, dissolved oxygen and conductivity, and river volume (depth, width, and discharge) as being of significant value in defining control and treatment groups in both years

Iron colloids reduce the bioavailability of phosphorus to the green alga Raphidocelis subcapitata.

Science.gov (United States)

Baken, Stijn; Nawara, Sophie; Van Moorleghem, Christoff; Smolders, Erik

2014-08-01

Phosphorus (P) is a limiting nutrient in many aquatic systems. The bioavailability of P in natural waters strongly depends on its speciation. In this study, structural properties of iron colloids were determined and related to their effect on P sorption and P bioavailability. The freshwater green alga Raphidocelis subcapitata was exposed to media spiked with radiolabelled (33)PO4, and the uptake of (33)P was monitored for 1 h. The media contained various concentrations of synthetic iron colloids with a size between 10 kDa and 0.45 μm. The iron colloids were stabilised by natural organic matter. EXAFS spectroscopy showed that these colloids predominantly consisted of ferrihydrite with small amounts of organically complexed Fe. In colloid-free treatments, the P uptake flux by the algae obeyed Michaelis-Menten kinetics. In the presence of iron colloids at 9 or 90 μM Fe, corresponding to molar P:Fe ratios between 0.02 and 0.17, the truly dissolved P (<10 kDa) was between 4 and 60% of the total dissolved P (<0.45 μm). These colloids reduced the P uptake flux by R. subcapitata compared to colloid-free treatments at the same total dissolved P concentration. However, the P uptake flux from colloid containing solutions equalled that from colloid-free ones when expressed as truly dissolved P. This demonstrates that colloidal P did not contribute to the P uptake flux. It is concluded that, on the short term, phosphate adsorbed to ferrihydrite colloids is not available to the green alga R. subcapitata. Copyright © 2014 Elsevier Ltd. All rights reserved.

Aquatic environmental risk assessment for human use of the old antibiotic sulfamethoxazole in Europe.

Science.gov (United States)

Straub, Jürg Oliver

2016-04-01

Sulfamethoxazole (SMX) is an old sulfonamide antibiotic that was launched first in combination with trimethoprim in 1969 by F.Hoffmann-La Roche. Although sales figures for SMX have been declining over the past 20 yr, the compound is still widely used; moreover, many measured environmental concentrations (MECs) are available from Europe, the United States, Asia, Australia, and Africa. To assess aquatic risks of SMX in Europe, the exposure of European surface waters was predicted based on actual sales figures from IMS Health, incorporating environmental fate data on one side, and based on collated MECs representing more than 5500 single measurements in Europe on the other. Environmental effects were assessed using chronic and subchronic ecotoxicity data for 16 groups of aquatic organisms, from periphyton communities to cyanobacteria, algae, higher plants, various invertebrates, and vertebrates. Predicted no-effect concentrations (PNECs) were derived using both deterministic and probabilistic methodology. The predicted environmental concentration (PEC)/PNEC and MEC/PNEC comparisons overall showed no appreciable risk, except in a low incidence (risk characterization ratios greater than 1. The PNECs derived in the present study can be used to extend aquatic environmental risk assessment for SMX to other continents. No risk appears for indirect human exposure to SMX via the environment. © 2015 SETAC.

Prospects of using algae in biofuel production

Directory of Open Access Journals (Sweden)

Y. I. Maltsev

2017-08-01

Full Text Available The development of industry, agriculture and the transport sector is associated with the use of various energy sources. Renewable energy sources, including biofuels, are highly promising in this respect. As shown by a number of scientific studies, a promising source for biofuel production that would meet modern requirements may be algal biomass. After activation of the third generation biodiesel production it was assumed that the algae would become the most advantageous source, because it is not only able to accumulate significant amounts of lipids, but could reduce the of agricultural land involved in biofuel production and improve air quality by sequestering CO2. However, a major problem is presented by the cost of algae biomass cultivation and its processing compared to the production of biodiesel from agricultural crops. In this regard, there are several directions of increasing the efficiency of biodiesel production from algae biomass. The first direction is to increase lipid content in algae cells by means of genetic engineering. The second direction is connected with the stimulation of increased accumulation of lipids by stressing algae. The third direction involves the search for new, promising strains of algae that will be characterized by faster biomass accumulation rate, higher content of TAG and the optimal proportions of accumulated saturated and unsaturated fatty acids compared to the already known strains. Recently, a new approach in the search for biotechnologically valuable strains of algae has been formed on the basis of predictions of capacity for sufficient accumulation of lipids by clarifying the evolutionary relationships within the major taxonomic groups of algae. The outcome of these studies is the rapid cost reduction of biofuel production based on algae biomass. All this emphasizes the priority of any research aimed at both improving the process of production of biofuels from algae, and the search for new sources for

A comparison between MARKAL-MACRO and MARKAL

International Nuclear Information System (INIS)

Schepers, E.

1995-11-01

Differences between CO 2 -reduction scenarios of the MARKAL-MACRO model and the MARKAL model are studied. Also attention is paid to the rebound effect, i.e. the effect on a price decrease leads to an increase of the energy demand, and energy savings will result in a redistribution of saved income over other goods and services. MARKAL is an energy supply model and MACRO is a macro-economic model. The combination of the two is an example of a hard-linked model between a top-down model (MACRO) and a bottom-up model (MARKAL). 15 figs., 5 tabs., 18 refs., 2 appendices

[Effects of large-area planting water hyacinth on macro-benthos community structure and biomass].

Science.gov (United States)

Liu, Guo-Feng; Liu, Hai-Qin; Zhang, Zhi-Yong; Zhang, Ying-Ying; Yan, Shao-Hua; Zhong, Ji-Cheng; Fan, Cheng-Xin

2010-12-01

The effects on macro-benthos and benthos environment of planting 200 hm2 water hyacinth (E. crassipens) in Zhushan Bay, Lake Taihu, were studied during 8-10 months consecutive surveys. Results indicated that average densities of mollusca (the main species were Bellamya aeruginosa) in far-planting, near-planting and planting area were 276.67, 371.11 and 440.00 ind/m2, respectively, and biomass were 373.15, 486.57 and 672.54 g/m2, respectively, showed that average density and biomass of planting area's were higher than those of others. However, the average density and biomass of Oligochaeta (the main species was Limodrilus hoffmeisteri) and Chironomidae in planting area were lower than that of outside planting area. The density and biomass of three dominant species of benthic animal increased quickly during 8-9 months, decreased quickly in October inside and outside water hyacinth planting area. The reason of this phenomenon could be possible that lots of cyanobacteria cells died and consumed dissolve oxygen in proceed decomposing. Algae cells released lots of phosphorus and nitrogen simultaneously, so macro-benthos died in this environment. The indexes of Shannon-Weaver and Simpson indicated that water environment was in moderate polluted state. On the basis of the survey results, the large-area and high-density planting water hyacinth haven't demonstrated a great impact on macrobenthos and benthos environment in short planting time (about 6 months planting time).

Macro-prudentiality and financial stability

Directory of Open Access Journals (Sweden)

Cristian Ionescu

2012-12-01

Full Text Available Taking into consideration the fact that financial crises, as a manifestation form of the financial instability, are becoming more and more frequent, complex and severe, it is important to discuss about the macroeconomic prudentiality, in order to protect and save the economy of a country or of a region by the inherent fragility of a very developed financial system. Therefore, the paper aims to analyze the following aspects: the macro-prudential regulation (in order to a better understanding of the financial instability process, the development of the macro-prudential vision and instruments (but emphasizing the existing limits and economic policies (in order to implement an operational macro-prudential regulation.

Growth acceleration and photosynthesis of the scenedesmus algae and cocconeis algae in deuterium water

International Nuclear Information System (INIS)

Liu Feng; Wang Wenqing

1998-01-01

In order to find new way to treat the radioactive tritium waste water, scenedesmus algae and cocconeis algae are cultured in medium which contains 30% (w) deuterium water. During different time, activities of photosymthesis, absorption spectrum, growth rate and low-temperature fluorescence spectrum are measured. Accelerated growth is found in the deuterium water compared to the normal water. Activities of photosynthesis show the similar result (F v /F m ) to the growth data. It is also concluded from low-temperature fluorescence spectra that algae activities in the deuterium water, which are expressed by PS I/PS II, are more sensitive than those in the normal water

Cars will be fed on algae

International Nuclear Information System (INIS)

Peltier, G.

2012-01-01

The development of the first and second generations of bio-fuels has led to a rise in food prices and the carbon balance sheet is less good than expected. Great hopes have been put on unicellular algae for they can synthesize oils, sugar and even hydrogen and the competition with food production is far less harsh than with actual bio-fuels. Moreover, when you grow micro-algae, the loss of water through evaporation is less important than in the case of intensive farm cultures. In 2009 10.000 tonnes of micro-algae were produced worldwide, they were mainly used for the production of fish food and of complements for humane food (fat acids and antioxidants). Different research programs concern unicellular algae: they aim at modifying micro-algae genetically in order to give them a higher productivity or to make them produce an oil more adapted for motor fuel or more easily recoverable. (A.C.)

The International Macro-Environment of an Organization

OpenAIRE

Ileana (Badulescu) Anastase; Cornel Grigorut

2016-01-01

The international macro-environment (supranational macro-environment) brings together allthe uncontrollable factors with a global impact, and it is related to the organization’s indirectrelationships on international markets. Romania’s globalization and the EU integration increasedthe importance of the macro-environment for all organizations, regardless of their degree ofinternationalization. In marketing, we must master the main agreements between countries and theregulations emanating from ...

Cellulose powder from Cladophora sp. algae.

Science.gov (United States)

Ek, R; Gustafsson, C; Nutt, A; Iversen, T; Nyström, C

1998-01-01

The surface are and crystallinity was measured on a cellulose powder made from Cladophora sp. algae. The algae cellulose powder was found to have a very high surface area (63.4 m2/g, N2 gas adsorption) and build up of cellulose with a high crystallinity (approximately 100%, solid state NMR). The high surface area was confirmed by calculations from atomic force microscope imaging of microfibrils from Cladophora sp. algae.

Inventory of North-West European algae initiatives

NARCIS (Netherlands)

Spruijt, J.

2015-01-01

In 2012 an inventory of North-West European (NWE) algae initiatives was carried out to get an impression of the market and research activities on algae production and refinery, especially for bioenergy purposes. A questionnaire was developed that would provide the EnAlgae project with information on

Lipid oxidation in base algae oil and water-in-algae oil emulsion: Impact of natural antioxidants and emulsifiers.

Science.gov (United States)

Chen, Bingcan; Rao, Jiajia; Ding, Yangping; McClements, David Julian; Decker, Eric Andrew

2016-07-01

The impact of natural hydrophilic antioxidants, metal chelators, and hydrophilic antioxidant/metal chelator mixture on the oxidative stability of base algae oil and water-in-algae oil emulsion was investigated. The results showed that green tea extract and ascorbic acid had greatest protective effect against algae oil oxidation and generated four day lag phase, whereas rosmarinic acid, grape seed extract, grape seed extract polymer, deferoxamine (DFO), and ethylenediaminetetraacetic acid (EDTA) had no significant protective effect. Besides, there was no synergistic effect observed between natural antioxidants and ascorbic acid. The emulsifiers are critical to the physicochemical stability of water-in-algae oil emulsions. Polyglycerol polyricinoleate (PGPR) promoted the oxidation of emulsion. Conversely, the protective effect on algae oil oxidation was appreciated when defatted soybean lecithin (PC 75) or defatted lyso-lecithin (Lyso-PC) was added. The role of hydrophilic antioxidants in emulsion was similar to that in algae oil except EDTA which demonstrated strong antioxidative effect in emulsion. The results could provide information to build up stable food products containing polyunsaturated fatty acids (PUFA). Copyright © 2016 Elsevier Ltd. All rights reserved.

Program GICC - AQUABIO. Possible consequences of the climatic change on the aquatic and river french biocenoses. Final report

International Nuclear Information System (INIS)

Pont, D.

2003-11-01

The consequences of the climatic change can modify the ecosystems. The aim of this research program is to analyze the impacts of the climatic change on the propagation of the exotic species in France in aquatic and river environment, the population of macro invertebrates and fishes in the french rivers and the socio economic challenges. The methodology is based on the simulation from the exploitation of great data bases and the combination of many approaches at different scales. (A.L.B.)

Antioxidant Activity of Hawaiian Marine Algae

Directory of Open Access Journals (Sweden)

Anthony D. Wright

2012-02-01

Full Text Available 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.

Macro-Invertebrate Decline in Surface Water Polluted with Imidacloprid: A Rebuttal and Some New Analyses

Science.gov (United States)

Vijver, Martina G.; van den Brink, Paul J.

2014-01-01

Imidacloprid, the largest selling insecticide in the world, has received particular attention from scientists, policymakers and industries due to its potential toxicity to bees and aquatic organisms. The decline of aquatic macro-invertebrates due to imidacloprid concentrations in the Dutch surface waters was hypothesised in a recent paper by Van Dijk, Van Staalduinen and Van der Sluijs (PLOS ONE, May 2013). Although we do not disagree with imidacloprid's inherent toxicity to aquatic organisms, we have fundamental concerns regarding the way the data were analysed and interpreted. Here, we demonstrate that the underlying toxicity of imidacloprid in the field situation cannot be understood except in the context of other co-occurring pesticides. Although we agree with Van Dijk and co-workers that effects of imidacloprid can emerge between 13 and 67 ng/L we use a different line of evidence. We present an alternative approach to link imidacloprid concentrations and biological data. We analysed the national set of chemical monitoring data of the year 2009 to estimate the relative contribution of imidacloprid compared to other pesticides in relation to environmental quality target and chronic ecotoxicity threshold exceedances. Moreover, we assessed the relative impact of imidacloprid on the pesticide-induced potential affected fractions of the aquatic communities. We conclude that by choosing to test a starting hypothesis using insufficient data on chemistry and biology that are difficult to link, and by ignoring potential collinear effects of other pesticides present in Dutch surface waters Van Dijk and co-workers do not provide direct evidence that reduced taxon richness and abundance of macroinvertebrates can be attributed to the presence of imidacloprid only. Using a different line of evidence we expect ecological effects of imidacloprid at some of the exposure profiles measured in 2009 in the surface waters of the Netherlands. PMID:24587069

Macro-invertebrate decline in surface water polluted with imidacloprid: a rebuttal and some new analyses.

Directory of Open Access Journals (Sweden)

Martina G Vijver

Full Text Available Imidacloprid, the largest selling insecticide in the world, has received particular attention from scientists, policymakers and industries due to its potential toxicity to bees and aquatic organisms. The decline of aquatic macro-invertebrates due to imidacloprid concentrations in the Dutch surface waters was hypothesised in a recent paper by Van Dijk, Van Staalduinen and Van der Sluijs (PLOS ONE, May 2013. Although we do not disagree with imidacloprid's inherent toxicity to aquatic organisms, we have fundamental concerns regarding the way the data were analysed and interpreted. Here, we demonstrate that the underlying toxicity of imidacloprid in the field situation cannot be understood except in the context of other co-occurring pesticides. Although we agree with Van Dijk and co-workers that effects of imidacloprid can emerge between 13 and 67 ng/L we use a different line of evidence. We present an alternative approach to link imidacloprid concentrations and biological data. We analysed the national set of chemical monitoring data of the year 2009 to estimate the relative contribution of imidacloprid compared to other pesticides in relation to environmental quality target and chronic ecotoxicity threshold exceedances. Moreover, we assessed the relative impact of imidacloprid on the pesticide-induced potential affected fractions of the aquatic communities. We conclude that by choosing to test a starting hypothesis using insufficient data on chemistry and biology that are difficult to link, and by ignoring potential collinear effects of other pesticides present in Dutch surface waters Van Dijk and co-workers do not provide direct evidence that reduced taxon richness and abundance of macroinvertebrates can be attributed to the presence of imidacloprid only. Using a different line of evidence we expect ecological effects of imidacloprid at some of the exposure profiles measured in 2009 in the surface waters of the Netherlands.

Remote Sensing of Submerged Aquatic Vegetation in a Shallow Non-Turbid River Using an Unmanned Aerial Vehicle

Directory of Open Access Journals (Sweden)

Kyle F. Flynn

2014-12-01

Full Text Available A passive method for remote sensing of the nuisance green algae Cladophora glomerata in rivers is presented using an unmanned aerial vehicle (UAV. Included are methods for UAV operation, lens distortion correction, image georeferencing, and spectral analysis to support algal cover mapping. Eighteen aerial photography missions were conducted over the summer of 2013 using an off-the-shelf UAV and three-band, wide-angle, red, green, and blue (RGB digital camera sensor. Images were post-processed, mosaicked, and georeferenced so automated classification and mapping could be completed. An adaptive cosine estimator (ACE and spectral angle mapper (SAM algorithm were used to complete the algal identification. Digital analysis of optical imagery correctly identified filamentous algae and background coverage 90% and 92% of the time, and tau coefficients were 0.82 and 0.84 for ACE and SAM, respectively. Thereafter, algal cover was characterized for a one-kilometer channel segment during each of the 18 UAV flights. Percent cover ranged from <5% to >50%, and increased immediately after vernal freshet, peaked in midsummer, and declined in the fall. Results indicate that optical remote sensing with UAV holds promise for completing spatially precise, and multi-temporal measurements of algae or submerged aquatic vegetation in shallow rivers with low turbidity and good optical transmission.

Algae production for energy and foddering

Energy Technology Data Exchange (ETDEWEB)

Bai, Attila; Jobbagy, Peter; Durko, Emilia [University of Debrecen, Faculty of Applied Economics and Rural Development (UD-FAERD), Centre for Agricultural and Applied Economic Sciences, Debrecen (Hungary)

2011-09-15

This study not only presents the results of our own experiments in alga production, but also shows the expected economic results of the various uses of algae (animal feed, direct burning, pelleting, bio-diesel production), the technical characteristics of a new pelleting method based on literature, and also our own recommended alga production technology. In our opinion, the most promising alternative could be the production of alga species with high levels of oil content, which are suitable for utilization as by-products for animal feed and in the production of bio-diesel, as well as for use in waste water management and as a flue gas additive. Based on the data from our laboratory experiments, of the four species we analyzed, Chlorella vulgaris should be considered the most promising species for use in large-scale experiments. Taking expenses into account, our results demonstrate that the use of algae for burning technology purposes results in a significant loss under the current economic conditions; however, the utilization of algae for feeding and bio-diesel purposes - in spite of their innovative nature - is nearing the level needed for competitiveness. By using the alga production technology recommended by us and described in the present study in detail, with an investment of 545 to 727 thousand EUR/ha, this technology should be able to achieve approximately 0-29 thousand EUR/ha net income, depending on size. More favorable values emerge in the case of the 1-ha (larger) size, thanks to the significant savings on fixed costs (depreciation and personnel costs). (orig.)

Tracing carbon sources through aquatic and terrestrial food webs using amino acid stable isotope fingerprinting.

Directory of Open Access Journals (Sweden)

Thomas Larsen

Full Text Available Tracing the origin of nutrients is a fundamental goal of food web research but methodological issues associated with current research techniques such as using stable isotope ratios of bulk tissue can lead to confounding results. We investigated whether naturally occurring δ(13C patterns among amino acids (δ(13CAA could distinguish between multiple aquatic and terrestrial primary production sources. We found that δ(13CAA patterns in contrast to bulk δ(13C values distinguished between carbon derived from algae, seagrass, terrestrial plants, bacteria and fungi. Furthermore, we showed for two aquatic producers that their δ(13CAA patterns were largely unaffected by different environmental conditions despite substantial shifts in bulk δ(13C values. The potential of assessing the major carbon sources at the base of the food web was demonstrated for freshwater, pelagic, and estuarine consumers; consumer δ(13C patterns of essential amino acids largely matched those of the dominant primary producers in each system. Since amino acids make up about half of organismal carbon, source diagnostic isotope fingerprints can be used as a new complementary approach to overcome some of the limitations of variable source bulk isotope values commonly encountered in estuarine areas and other complex environments with mixed aquatic and terrestrial inputs.

Tracing carbon sources through aquatic and terrestrial food webs using amino acid stable isotope fingerprinting.

Science.gov (United States)

Larsen, Thomas; Ventura, Marc; Andersen, Nils; O'Brien, Diane M; Piatkowski, Uwe; McCarthy, Matthew D

2013-01-01

Tracing the origin of nutrients is a fundamental goal of food web research but methodological issues associated with current research techniques such as using stable isotope ratios of bulk tissue can lead to confounding results. We investigated whether naturally occurring δ(13)C patterns among amino acids (δ(13)CAA) could distinguish between multiple aquatic and terrestrial primary production sources. We found that δ(13)CAA patterns in contrast to bulk δ(13)C values distinguished between carbon derived from algae, seagrass, terrestrial plants, bacteria and fungi. Furthermore, we showed for two aquatic producers that their δ(13)CAA patterns were largely unaffected by different environmental conditions despite substantial shifts in bulk δ(13)C values. The potential of assessing the major carbon sources at the base of the food web was demonstrated for freshwater, pelagic, and estuarine consumers; consumer δ(13)C patterns of essential amino acids largely matched those of the dominant primary producers in each system. Since amino acids make up about half of organismal carbon, source diagnostic isotope fingerprints can be used as a new complementary approach to overcome some of the limitations of variable source bulk isotope values commonly encountered in estuarine areas and other complex environments with mixed aquatic and terrestrial inputs.

Shewanella algae in acute gastroenteritis

Directory of Open Access Journals (Sweden)

S Dey

2015-01-01

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

Micro-algae: French players discuss the matter

International Nuclear Information System (INIS)

Bouveret, T.

2013-01-01

About 75000 species of algae have been reported so far, the domains of application are huge and investment are increasing all around the world. One of the difficulties is to find the most appropriate algae to a specific application. Some development programs have failed scientifically or economically for instance the production of protein for animal food from the chlorella algae or the production of bio-fuel from C14-C18 chains, from zeaxanthine and from phycoerytrine. On the other side some research programs have led to promising industrial applications such as the production of food for fish and farm animals. Some research fields are completely innovative such as the use of micro-algae for the construction of bio-walls for buildings. Micro-algae are diverse and fragile. Photo-bioreactors have been designed to breed fragile algae like some types of chlorophycees used in bio-fuel and in cosmetics, a prototype has been tested for 15 months and its production is about 2 kg of dry matter a day. (A.C.)

Economic evaluation of algae biodiesel based on meta-analyses

Science.gov (United States)

Zhang, Yongli; Liu, Xiaowei; White, Mark A.; Colosi, Lisa M.

2017-08-01

The objective of this study is to elucidate the economic viability of algae-to-energy systems at a large scale, by developing a meta-analysis of five previously published economic evaluations of systems producing algae biodiesel. Data from original studies were harmonised into a standardised framework using financial and technical assumptions. Results suggest that the selling price of algae biodiesel under the base case would be 5.00-10.31/gal, higher than the selected benchmarks: 3.77/gal for petroleum diesel, and 4.21/gal for commercial biodiesel (B100) from conventional vegetable oil or animal fat. However, the projected selling price of algal biodiesel (2.76-4.92/gal), following anticipated improvements, would be competitive. A scenario-based sensitivity analysis reveals that the price of algae biodiesel is most sensitive to algae biomass productivity, algae oil content, and algae cultivation cost. This indicates that the improvements in the yield, quality, and cost of algae feedstock could be the key factors to make algae-derived biodiesel economically viable.

Study of Water Quality Value in Sub of the Stream Area of Cisadane Rivers Upstream as Reference Area Based on Macro invertebrate Composition

International Nuclear Information System (INIS)

Sri-Unon-Purwati

2001-01-01

Specific structure of biota community condition can used as indicator for the ecosystem stability value or the waters pollution level where the aquatic biota exist. the macro invertebrates as bio indicator organism can used to assess the upper Cisadane Sub River Basin water quality. The grouping and calculation result from family number, Ept presences (sensitive macro invertebrate), Diversity index (H ' ), DO value and TOC value showed 5 criteria of water quality as reference site. This criteria is used to determine water quality level from ten branches of rivers in the upper Cisadane Sub River Basin, Cijeruk districts. The biotic index calculation for ASPT (Average Score Per Taxon) and T and T (index Trihadiningrum and Tjindronegoro) is used to asses water quality based on macro invertebrate composition indicator. Both biotic index system support and give the similar evaluation to water quality level from ten branches of river on the upper Cisadane Sub River Basin. The water quality level is described as fellows: station number 4 is assumed as the true reference site, station number 3, 5, 8 are the first alternative reference site, station number 2, 7, 9 are the second alternative reference site and station 1, 6, 10 are the sites which relatively good water quality, but it is not recommended as reference site. The grouping result bases on the cluster system with macro invertebrate similarity composition are described as fellows: 9=10>3=7>1=6>2=8>>5>>4. (author)

Writing Excel Macros with VBA

CERN Document Server

Roman, Steven

2008-01-01

To achieve the maximum control and flexibility from Microsoft® Excel often requires careful custom programming using the VBA (Visual Basic for Applications) language. Writing Excel Macros with VBA, 2nd Edition offers a solid introduction to writing VBA macros and programs, and will show you how to get more power at the programming level: focusing on programming languages, the Visual Basic Editor, handling code, and the Excel object model.

Estimation of Heavy Elements Pollution in Sea Plants (Algae) by Using Neutron Activation Analysis

International Nuclear Information System (INIS)

El-Ghondi, A. A.; El-Mismary, Y. A.; Etwir, R. H.; Machiouf, M. A.; Ben Shaban, Y.; Abia, R.

2007-01-01

The total content of trace elements were determined in 50 samples of sea plants (macro algae) collected from Tripoli coast area (Tajura, El schab, Dat Elemad ) in Libya. The samples were investigated as an indication of heavy elements pollution. In this paper, the total amounts of Zn, Sc, Fe, Co, Cr, Ba, Cs, Sb, Rb, and Hf concentration were determined by using Neutron Activation Analysis in Tajura research center. High levels of Zn and Cr and slightly increasing in amount of Co and Fe are considered as normal values comparing with polluted area particularly with Fe and Co in investigated samples. Statistical calculation of the results have shown a positive relationship between the contents of Ba, Sc, Hf, Cr and Fe-Sb but no relation with Zn and other investigated trace elements contents. Further investigation should be carried out to confirm these findings and correlate them to source attribution.

Bioavailability of mineral-bound iron to a snow algae-bacteria co-culture and implications for albedo-altering snow algae blooms.

Science.gov (United States)

Harrold, Z R; Hausrath, E M; Garcia, A H; Murray, A E; Tschauner, O; Raymond, J; Huang, S

2018-01-26

Snow algae can form large-scale blooms across the snowpack surface and near-surface environments. These pigmented blooms can decrease snow albedo, increase local melt rates, and may impact the global heat budget and water cycle. Yet, underlying causes for the geospatial occurrence of these blooms remain unconstrained. One possible factor contributing to snow algae blooms is the presence of mineral dust as a micronutrient source. We investigated the bioavailability of iron (Fe) -bearing minerals, including forsterite (Fo 90 , Mg 1.8 Fe 0.2 SiO 4 ), goethite, smectite and pyrite as Fe sources for a Chloromonas brevispina - bacteria co-culture through laboratory-based experimentation. Fo 90 was capable of stimulating snow algal growth and increased the algal growth rate in otherwise Fe-depleted co-cultures. Fo 90 -bearing systems also exhibited a decrease in bacteria:algae ratios compared to Fe-depleted conditions, suggesting a shift in microbial community structure. The C. brevispina co-culture also increased the rate of Fo 90 dissolution relative to an abiotic control. Analysis of 16S rRNA genes in the co-culture identified Gammaproteobacteria , Betaprotoeobacteria and Sphingobacteria , all of which are commonly found in snow and ice environments. Archaea were not detected. Collimonas and Pseudomonas , which are known to enhance mineral weathering rates, comprised two of the top eight (> 1 %) OTUs. These data provide unequivocal evidence that mineral dust can support elevated snow algae growth under otherwise Fe-depleted growth conditions, and that snow algae can enhance mineral dissolution under these conditions. IMPORTANCE Fe, a key micronutrient for photosynthetic growth, is necessary to support the formation of high-density snow algae blooms. The laboratory experiments described herein allow for a systematic investigation of snow algae-bacteria-mineral interactions and their ability to mobilize and uptake mineral-bound Fe. Results provide unequivocal and

Aquatic plants

DEFF Research Database (Denmark)

Madsen, T. V.; Sand-Jensen, K.

2006-01-01

Aquatic fl owering plants form a relatively young plant group on an evolutionary timescale. The group has developed over the past 80 million years from terrestrial fl owering plants that re-colonised the aquatic environment after 60-100 million years on land. The exchange of species between terre...... terrestrial and aquatic environments continues today and is very intensive along stream banks. In this chapter we describe the physical and chemical barriers to the exchange of plants between land and water.......Aquatic fl owering plants form a relatively young plant group on an evolutionary timescale. The group has developed over the past 80 million years from terrestrial fl owering plants that re-colonised the aquatic environment after 60-100 million years on land. The exchange of species between...

Molecular toxicity of triclosan and carbamazepine to green algae Chlorococcum sp.: A single cell view using synchrotron-based Fourier transform infrared spectromicroscopy.

Science.gov (United States)

Xin, Xiaying; Huang, Guohe; Liu, Xia; An, Chunjiang; Yao, Yao; Weger, Harold; Zhang, Peng; Chen, Xiujuan

2017-07-01

Although pharmaceuticals and personal care products have been used and introduced into the environment in large quantities, little information on potential ecological risks is currently available considering their effects on living organisms. We verified the feasibility of using synchrotron-based Fourier Transform Infrared (SR-FTIR) spectromicroscopy to explore in vivo toxic effects on single living Chlorococcum sp. cells. The study provided important information to achieve a better understanding of the toxic mechanism of triclosan and carbamazepine on living algae Chlorococcum sp.. Triclosan and carbamazepine had distinctive toxic effects on unicellular living algae. Most strikingly, triclosan had more dramatic toxic effects on biochemical components than carbamazepine. Triclosan can affect algae primarily by inhibiting fatty acid synthesis and causing protein aggregation. The toxicity response was irreversible at higher concentration (100.000 μM), but attenuated at lower concentration (0.391 μM) as time extended. Carbamazepine can produce hydrophobic interactions to affect the phospholipid bilayer and work on specific proteins to disfunction the cell membrane. Carbamazepine-exposed cells developed a resistance while extending exposure time. This is the first demonstration from an ecological standpoint that SR-FTIR can provide an innovative approach to reveal the toxicity of emerging pollutants in aquatic environments. Copyright © 2017 Elsevier Ltd. All rights reserved.

Aquatic macro algae of a region under Almirante Alvaro Alberto nuclear power plant influence. I. Taxonomic composition

International Nuclear Information System (INIS)

Pedrini, A.G.; Universidade Santa Ursula, Rio de Janeiro, RJ; Cassano, V.; Coelho, L.G.; Labronici, G.J.

1994-01-01

A total of 134 taxa were found: 32 Chlorophyta, 29 Phaeophyta and 74 Rhodophyta. The Caulerpales (Chlorophyta) had the highest number of taxa (37,5%) followed by the Dictyotales (Phaeophyta - 43%) and Ceramiales (Rhodophyta - 53%). The benthic flora shows some affinity to that of Ilha Grande (part), Sepetiba Bay and Paraty (Sorensen's Index - 0,62, 0,61 and 0,58 respectively. (author). 22 refs, 1 fig, 1 tab

Ecotoxicity tests using the green algae Chlorella vulgaris--a useful tool in hazardous effluents management.

Science.gov (United States)

Silva, Aurora; Figueiredo, Sónia A; Sales, M Goreti; Delerue-Matos, Cristina

2009-08-15

The treatment efficiency of laboratory wastewaters was evaluated and ecotoxicity tests with Chlorella vulgaris were performed on them to assess the safety of their environmental discharge. For chemical oxygen demand wastewaters, chromium (VI), mercury (II) and silver were efficiently removed by chemical treatments. A reduction of ecotoxicity was achieved; nevertheless, an EC50 (effective concentration that causes a 50% inhibition in the algae growth) of 1.5% (v/v) indicated still high level of ecotoxicity. For chloride determination wastewaters, an efficient reduction of chromium and silver was achieved after treatment. Regarding the reduction of ecotoxicity observed, EC50 increased from 0.059% to 0.5%, only a 0.02% concentration in the aquatic environment would guarantee no effects. Wastewaters containing phenanthroline/iron (II) complex were treated by chemical oxidation. Treatment was satisfactory concerning chemical parameters, although an increase in ecotoxicity was observed (EC50 reduced from 0.31% to 0.21%). The wastes from the kinetic study of persulphate and iodide reaction were treated with sodium bisulphite until colour was removed. Although they did not reveal significant ecotoxicity, only over 1% of the untreated waste produced observable effects over algae. Therefore, ecotoxicity tests could be considered a useful tool not only in laboratory effluents treatment, as shown, but also in hazardous wastewaters management.

Ecotoxicity tests using the green algae Chlorella vulgaris-A useful tool in hazardous effluents management

Energy Technology Data Exchange (ETDEWEB)

Silva, Aurora [REQUIMTE, Instituto Superior de Engenharia do Instituto Politecnico do Porto, R. Antonio Bernardino de Almeida, 431 4200-072 Porto (Portugal); Figueiredo, Sonia A., E-mail: saf@isep.ipp.pt [REQUIMTE, Instituto Superior de Engenharia do Instituto Politecnico do Porto, R. Antonio Bernardino de Almeida, 431 4200-072 Porto (Portugal); Sales, M. Goreti; Delerue-Matos, Cristina [REQUIMTE, Instituto Superior de Engenharia do Instituto Politecnico do Porto, R. Antonio Bernardino de Almeida, 431 4200-072 Porto (Portugal)

2009-08-15

The treatment efficiency of laboratory wastewaters was evaluated and ecotoxicity tests with Chlorella vulgaris were performed on them to assess the safety of their environmental discharge. For chemical oxygen demand wastewaters, chromium (VI), mercury (II) and silver were efficiently removed by chemical treatments. A reduction of ecotoxicity was achieved; nevertheless, an EC50 (effective concentration that causes a 50% inhibition in the algae growth) of 1.5% (v/v) indicated still high level of ecotoxicity. For chloride determination wastewaters, an efficient reduction of chromium and silver was achieved after treatment. Regarding the reduction of ecotoxicity observed, EC50 increased from 0.059% to 0.5%, only a 0.02% concentration in the aquatic environment would guarantee no effects. Wastewaters containing phenanthroline/iron (II) complex were treated by chemical oxidation. Treatment was satisfactory concerning chemical parameters, although an increase in ecotoxicity was observed (EC50 reduced from 0.31% to 0.21%). The wastes from the kinetic study of persulphate and iodide reaction were treated with sodium bisulphite until colour was removed. Although they did not reveal significant ecotoxicity, only over 1% of the untreated waste produced observable effects over algae. Therefore, ecotoxicity tests could be considered a useful tool not only in laboratory effluents treatment, as shown, but also in hazardous wastewaters management.

Ecotoxicity tests using the green algae Chlorella vulgaris-A useful tool in hazardous effluents management

International Nuclear Information System (INIS)

Silva, Aurora; Figueiredo, Sonia A.; Sales, M. Goreti; Delerue-Matos, Cristina

2009-01-01

The treatment efficiency of laboratory wastewaters was evaluated and ecotoxicity tests with Chlorella vulgaris were performed on them to assess the safety of their environmental discharge. For chemical oxygen demand wastewaters, chromium (VI), mercury (II) and silver were efficiently removed by chemical treatments. A reduction of ecotoxicity was achieved; nevertheless, an EC50 (effective concentration that causes a 50% inhibition in the algae growth) of 1.5% (v/v) indicated still high level of ecotoxicity. For chloride determination wastewaters, an efficient reduction of chromium and silver was achieved after treatment. Regarding the reduction of ecotoxicity observed, EC50 increased from 0.059% to 0.5%, only a 0.02% concentration in the aquatic environment would guarantee no effects. Wastewaters containing phenanthroline/iron (II) complex were treated by chemical oxidation. Treatment was satisfactory concerning chemical parameters, although an increase in ecotoxicity was observed (EC50 reduced from 0.31% to 0.21%). The wastes from the kinetic study of persulphate and iodide reaction were treated with sodium bisulphite until colour was removed. Although they did not reveal significant ecotoxicity, only over 1% of the untreated waste produced observable effects over algae. Therefore, ecotoxicity tests could be considered a useful tool not only in laboratory effluents treatment, as shown, but also in hazardous wastewaters management.

On the uptake and binding of uranium (VI) by the green alga Chlorella Vulgaris

International Nuclear Information System (INIS)

Vogel, Manja

2011-01-01

Uranium could be released into the environment from geogenic deposits and from former mining and milling areas by weathering and anthropogenic activities. The elucidation of uranium behavior in geo- and biosphere is necessary for a reliable risk assessment of radionuclide migration in the environment. Algae are widespread in nature and the most important group of organisms in the aquatic habitat. Because of their ubiquitous occurrence in nature the influence of algae on the migration process of uranium in the environment is of fundamental interest e.g. for the development of effective and economical remediation strategies for contaminated waters. Besides, algae are standing at the beginning of the food chain and play an economically relevant role as food and food additive. Therefore the transfer of algae-bound uranium along the food chain could arise to a serious threat to human health. Aim of this work was the quantitative and structural characterization of the interaction between U(VI) and the green alga Chlorella vulgaris in environmental relevant concentration and pH range with special emphasis on metabolic activity. Therefore a defined medium was created which assures the survival/growth of the algae as well as the possibility to predict the uranium speciation. The speciation of uranium in the mineral medium was calculated and experimentally verified by time-resolved laser-induced fluorescence spectroscopy (TRLFS). The results of the sorption experiments showed that both metabolic active and inactive algal cells bind uranium in significant amounts of around 14 mg U/g dry biomass and 28 mg U/g dry biomass, respectively. Another interesting observation was made during the growth of Chlorella cells in mineral medium at the environmental relevant uranium concentration of 5 μM. Under these conditions and during ongoing cultivation a mobilization of the algae-bound uranium occurred. At higher uranium concentrations this effect was not observed due to the die off of

MACROPHYTE RICHNESS AND AQUATIC VEGETATION COMPLEXITY OF THE LAKE IDRO (NORTHERN ITALY

Directory of Open Access Journals (Sweden)

R. Bolpagni

2013-04-01

Full Text Available A detailed survey was performed to examine the floristic richness and the structural complexity, spatial patterns and conservation value of aquatic plant communities within the littorals of Lake Idro (northern Italy. During the summers of 2010-2011 we proceeded to characterize aquatic macrophyte meadows applying standardized procedures using transects (44 and plots (49 arrayed perpendicular to the shoreline and randomly positioned within the vegetated belt, respectively. Lake Idro is characterized by rather high floristic richness (20 macrophytes but low levels of vegetation structural complexity (8 vegetation units. Nevertheless, a clear zonation of the littoral vegetation was identified with two main macro-layers: a deeper layer (between 6-10 m of depth dominated by Chara globularis and an upper one (from 6 m of depth to water-air atmosphere mainly colonized by alien elodeids (mainly Elodea nuttallii and Lagarosiphon major. For the first time a complete floristic-vegetation analysis of the Lake Idro was presented. Our data confirm the poor ecological status of the basin, even though the lacustrine vegetation can be considered of conservation concern. Further investigations are needed to improve present evaluations, especially with respect to the impact of eutrophication on macrophytic communities.

Algae to Economically Viable Low-Carbon-Footprint Oil.

Science.gov (United States)

Bhujade, Ramesh; Chidambaram, Mandan; Kumar, Avnish; Sapre, Ajit

2017-06-07

Algal oil as an alternative to fossil fuel has attracted attention since the 1940s, when it was discovered that many microalgae species can produce large amounts of lipids. Economics and energy security were the motivational factors for a spurt in algae research during the 1970s, 1990s, and early 2000s. Whenever crude prices declined, research on algae stopped. The scenario today is different. Even given low and volatile crude prices ($30-$50/barrel), interest in algae continues all over the world. Algae, with their cure-all characteristics, have the potential to provide sustainable solutions to problems in the energy-food-climate nexus. However, after years of effort, there are no signs of algae-to-biofuel technology being commercialized. This article critically reviews past work; summarizes the current status of the technology; and based on the lessons learned, provides a balanced perspective on a potential path toward commercialization of algae-to-oil technology.

Effect of ferrate on green algae removal.

Science.gov (United States)

Kubiňáková, Emília; Híveš, Ján; Gál, Miroslav; Fašková, Andrea

2017-09-01

Green algae Cladophora aegagropila, present in cooling water of thermal power plants, causes many problems and complications, especially during summer. However, algae and its metabolites are rarely eliminated by common removal methods. In this work, the elimination efficiency of electrochemically prepared potassium ferrate(VI) on algae from cooling water was investigated. The influence of experimental parameters, such as Fe(VI) dosage, application time, pH of the system, temperature and hydrodynamics of the solution on removal efficiency, was optimized. This study demonstrates that algae C. aegagropila can be effectively removed from cooling water by ferrate. Application of ferrate(VI) at the optimized dosage and under the suitable conditions (temperature, pH) leads to 100% removal of green algae Cladophora from the system. Environmentally friendly reduction products (Fe(III)) and coagulation properties favour the application of ferrate for the treatment of water contaminated with studied microorganisms compared to other methods such as chlorination and use of permanganate, where harmful products are produced.

Sustainable Algae Biodiesel Production in Cold Climates

Directory of Open Access Journals (Sweden)

Rudras Baliga

2010-01-01

Full Text Available This life cycle assessment aims to determine the most suitable operating conditions for algae biodiesel production in cold climates to minimize energy consumption and environmental impacts. Two hypothetical photobioreactor algae production and biodiesel plants located in Upstate New York (USA are modeled. The photobioreactor is assumed to be housed within a greenhouse that is located adjacent to a fossil fuel or biomass power plant that can supply waste heat and flue gas containing CO2 as a primary source of carbon. Model results show that the biodiesel areal productivity is high (19 to 25 L of BD/m2/yr. The total life cycle energy consumption was between 15 and 23 MJ/L of algae BD and 20 MJ/L of soy BD. Energy consumption and air emissions for algae biodiesel are substantially lower than soy biodiesel when waste heat was utilized. Algae's most substantial contribution is a significant decrease in the petroleum consumed to make the fuel.

Quantitative structure-activity relationships for green algae growth inhibition by polymer particles.

Science.gov (United States)

Nolte, Tom M; Peijnenburg, Willie J G M; Hendriks, A Jan; van de Meent, Dik

2017-07-01

After use and disposal of chemical products, many types of polymer particles end up in the aquatic environment with potential toxic effects to primary producers like green algae. In this study, we have developed Quantitative Structure-Activity Relationships (QSARs) for a set of highly structural diverse polymers which are capable to estimate green algae growth inhibition (EC50). The model (N = 43, R 2  = 0.73, RMSE = 0.28) is a regression-based decision tree using one structural descriptor for each of three polymer classes separated based on charge. The QSAR is applicable to linear homo polymers as well as copolymers and does not require information on the size of the polymer particle or underlying core material. Highly branched polymers, non-nitrogen cationic polymers and polymeric surfactants are not included in the model and thus cannot be evaluated. The model works best for cationic and non-ionic polymers for which cellular adsorption, disruption of the cell wall and photosynthesis inhibition were the mechanisms of action. For anionic polymers, specific properties of the polymer and test characteristics need to be known for detailed assessment. The data and QSAR results for anionic polymers, when combined with molecular dynamics simulations indicated that nutrient depletion is likely the dominant mode of toxicity. Nutrient depletion in turn, is determined by the non-linear interplay between polymer charge density and backbone flexibility. Copyright © 2017 Elsevier Ltd. All rights reserved.

Linking ground motion measurements and macro-seismic observations in France: A case study based on the RAP (accelerometric) and BCSF (macro-seismic) databases

International Nuclear Information System (INIS)

Lesueur, Ch.

2011-01-01

Comparison between accelerometric and macro-seismic observations is made for three mw∼4.5 earthquakes of eastern France between 2003 and 2005. Scalar and spectral instrumental parameters are processed from the accelerometric data recorded by nine accelerometric stations located between 29 km and 180 km from the epicentres. Macro-seismic data are based on the French internet reports. In addition to the individual macro-seismic intensity, analysis of the internal correlation between the encoded answers highlights four predominant fields of questions, bearing different physical meanings: 1) 'vibratory motions of small objects', 2) 'displacement and fall of objects', 3) 'acoustic noise', and 4) 'personal feelings'. Best correlations between macro-seismic and instrumental observations are obtained when the macro-seismic parameters are averaged over 10 km radius circles around each station. macro-seismic intensities predicted by published pgv-intensity relationships quite agree with the observed intensities, contrary to those based on pga. The correlations between the macro-seismic and instrumental data, for intensities between ii and v (ems-98), show that pgv is the instrumental parameter presenting the best correlation with all macro-seismic parameters. The correlation with response spectra, exhibits clear frequency dependence over a limited frequency range [0.5-33 hz]. Horizontal and vertical components are significantly correlated with macro-seismic parameters between 1 and 10 hz, a range corresponding to both natural frequencies of most buildings and high energy content in the seismic ground motion. Between 10 and 25 hz, a clear lack of correlation between macro-seismic and instrumental data is observed, while beyond 25 hz the correlation coefficient increases, approaching that of the PGA correlation level. (author)

Soil algae

African Journals Online (AJOL)

Timothy Ademakinwa

Also, the importance of algae in soil formation and soil fertility improvement cannot be over ... The presence of nitrogen fixing microalgae (Nostoc azollae) in the top soil of both vegetable ..... dung, fish food and dirty water from fish ponds on.

Photophysiology and cellular composition of sea ice algae

International Nuclear Information System (INIS)

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 μg C · μg chl -1 · h -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 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 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

[Heavy metal pollution ecology of macro-fungi: research advances and expectation].

Science.gov (United States)

Zhou, Qi-xing; An, Xin-long; Wei, Shu-he

2008-08-01

Macro-fungi are the main component of biosphere and one of the ecological resources, and play very important roles in matter cycling and in maintaining ecological balances. This paper summarized and reviewed the research advances in the eco-toxicological effects of heavy metals on macro-fungi, the bioaccumulation function of macro-fungi on heavy metals, the ecological adaptation mechanisms of macro-fungi to heavy metal pollution, the role of macro-fungi as a bio-indicator of heavy metal pollution, and the potential of macro-fungi in the ecological remediation of contaminated environment. To strengthen the researches on the heavy metal pollution ecology of macro-fungi would be of practical significance in the reasonable utilization of macro-fungi resources and in the ecological remediation of contaminated environment.

Macro and trace elements in Paracentrotus lividus gonads from South West Atlantic areas

DEFF Research Database (Denmark)

Camacho, Carolina; Rocha, A. Cristina; Barbosa, Vera L.

2018-01-01

Sea urchin represents one of the most valuable seafood product being harvested and explored for their edible part, the gonads or roe. This species is generally considered a sentinel organism for ecotoxicological studies being widely used in monitoring programs to assess coastal aquatic environments...... quality, because is directly exposed to anthropogenic contaminants in their habitat. In this context, the aim of this study is to evaluate the concentrations of macro (Cl, K, P, Ca, S) and trace (Zn, Br, Fe, Sr, I, Se, Rb, Cu, Cr, Ni, As, iAs, Cd, Pb, Hg) elements in Paracentrotus lividus gonads from...... three South West Atlantic production areas subjected to distinct environmental and anthropogenic pressures. In all studied areas, the elements profile in sea urchin gonads was Cl > K > P > Ca > S > Zn > Br > Fe > Sr > I > Rb > Cu > Se > Cr > Ni, suggesting an element guide profile with special interest...

The International Macro-Environment of an Organization

Directory of Open Access Journals (Sweden)

Ileana (Badulescu Anastase

2016-01-01

Full Text Available The international macro-environment (supranational macro-environment brings together allthe uncontrollable factors with a global impact, and it is related to the organization’s indirectrelationships on international markets. Romania’s globalization and the EU integration increasedthe importance of the macro-environment for all organizations, regardless of their degree ofinternationalization. In marketing, we must master the main agreements between countries and theregulations emanating from general international bodies, reflecting on their business, on differentforeign markets. Knowledge of the international environment is possible only through an analysisof its components (Anastase, I., 2012, p.41.

The toxicity of sulfolane and DIPA from sour gas plants to aquatic species

International Nuclear Information System (INIS)

Lintott, D.R.; Goudey, J.S.; Wilson, J.; Swanson, S.; Drury, C.

1997-01-01

The ecological effects of sulfolane and diisopropanolamine (DIPA), which are used to remove sulfur compounds from natural gas, were studied to establish risk-based cleanup criteria and to evaluate effective remedial measures. Toxicity tests were conducted on both the parent compounds and the thermal and biological degradation products. Toxicity testing focused on aquatic species because surface outlets, such as creeks, were found to be the major pathways for the water soluble DIPA and sulfolane chemicals. Sulfolane proved to be relatively non-toxic to aquatic species, with the exception of bacteria. DIPA was relatively toxic to algae at pH found in ground and surface waters. Aqueous and methanol reclaimer bottom extracts from five different gas plant sites were also tested using modified acute toxicity screening tests with different species. The reclaimer bottoms were found to be highly toxic to all species tested. DIPA and sulfolane did not entirely account for the toxicity of the reclaimer bottoms. Inorganic salts and metals present in reclaimer bottoms were found not to contribute to toxicity directly. The same was true for DIPA and sulfolane degradation products. 3 refs., 7 tabs., 8 figs

The toxicity of sulfolane and DIPA from sour gas plants to aquatic species

Energy Technology Data Exchange (ETDEWEB)

Lintott, D.R.; Goudey, J.S. [HydroQual Consultants, Inc., Calgary, AB (Canada); Wilson, J.; Swanson, S. [Golder Associates, Calgary, AB (Canada); Drury, C. [Shell Canada Ltd., Calgary, AB (Canada). Calgary Research Centre

1997-12-31

The ecological effects of sulfolane and diisopropanolamine (DIPA), which are used to remove sulfur compounds from natural gas, were studied to establish risk-based cleanup criteria and to evaluate effective remedial measures. Toxicity tests were conducted on both the parent compounds and the thermal and biological degradation products. Toxicity testing focused on aquatic species because surface outlets, such as creeks, were found to be the major pathways for the water soluble DIPA and sulfolane chemicals. Sulfolane proved to be relatively non-toxic to aquatic species, with the exception of bacteria. DIPA was relatively toxic to algae at pH found in ground and surface waters. Aqueous and methanol reclaimer bottom extracts from five different gas plant sites were also tested using modified acute toxicity screening tests with different species. The reclaimer bottoms were found to be highly toxic to all species tested. DIPA and sulfolane did not entirely account for the toxicity of the reclaimer bottoms. Inorganic salts and metals present in reclaimer bottoms were found not to contribute to toxicity directly. The same was true for DIPA and sulfolane degradation products. 3 refs., 7 tabs., 8 figs.

Method and apparatus for lysing and processing algae

Science.gov (United States)

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.

Importance of algae oil as a source of biodiesel

International Nuclear Information System (INIS)

Demirbas, Ayhan; Fatih Demirbas, M.

2011-01-01

Algae are the fastest-growing plants in the world. Industrial reactors for algal culture are open ponds, photobioreactors and closed systems. Algae are very important as a biomass source. Algae will some day be competitive as a source for biofuel. Different species of algae may be better suited for different types of fuel. Algae can be grown almost anywhere, even on sewage or salt water, and does not require fertile land or food crops, and processing requires less energy than the algae provides. Algae can be a replacement for oil based fuels, one that is more effective and has no disadvantages. Algae are among the fastest-growing plants in the world, and about 50% of their weight is oil. This lipid oil can be used to make biodiesel for cars, trucks, and airplanes. Microalgae have much faster growth-rates than terrestrial crops. the per unit area yield of oil from algae is estimated to be from 20,000 to 80,000 l per acre, per year; this is 7-31 times greater than the next best crop, palm oil. The lipid and fatty acid contents of microalgae vary in accordance with culture conditions. Most current research on oil extraction is focused on microalgae to produce biodiesel from algal oil. Algal-oil processes into biodiesel as easily as oil derived from land-based crops.

Phthalate esters in marine algae

OpenAIRE

Gezgin, Tuncay; Güven, Kasim Cemal; Akçin, Göksel

2001-01-01

Abstract o-Phthalate esters as diethyl phthalate, dibutyl phthalate, di-isobutyl phthalate and diethylhexyl phthalate were identified at surface and inner part of algae collected in the Bosphorus, as Ulva lactuca, Enteromorpha linza, Cystoseria barbata, Pterocladia capillaceaeand Ceramium rubrum. The same esters were also detected in seawater samples taken from the same area. Thus parallelism in pollution was noted between the algae and the surrounding seawater,

Ecological traits of the algae-bearing Tetrahymena utriculariae (Ciliophora) from traps of the aquatic carnivorous plant Utricularia reflexa

Czech Academy of Sciences Publication Activity Database

Šimek, Karel; Pitsch, G.; Salcher, Michaela M.; Sirová, Dagmara; Shabarova, Tatiana; Adamec, Lubomír; Posch, T.

2017-01-01

Roč. 64, č. 3 (2017), s. 336-348 ISSN 1066-5234 R&D Projects: GA ČR(CZ) GA13-00243S Institutional support: RVO:60077344 ; RVO:67985939 Keywords : aquatic Utricularia * bacterial turnover rate * ciliate bacterivory and mixotrophy * microbial interactions Subject RIV: EE - Microbiology, Virology OBOR OECD: Ecology; Microbiology (BU-J) Impact factor: 2.692, year: 2016

Uptake of americium-241 by algae and bacteria

Energy Technology Data Exchange (ETDEWEB)

Geisy, J P; Paine, D

1978-01-01

Algae and bacteria are important factors in the transport and mobilization of elements in the biosphere. These factors may be involved in trophic biomagnification, resulting in a potential human hazard or environmental degradation. Although americium, one of the most toxic elements known, is not required for plant growth, it may be concentrated by algae and bacteria. Therefore, the availability of americium-241 to algae and bacteria was studied to determine their role in the ultimate fate of this element released into the environment. Both algae and bacteria concentrated americium-241 to a high degree, making them important parts of the biomagnification process. The ability to concentrate americium-241 makes algae and bacteria potentially significant factors in cycling this element in the water column. (4 graphs, numerous references, 3 tables)

Composition of phytoplankton algae in Gubi Reservoir, Bauchi ...

African Journals Online (AJOL)

Studies on the distribution, abundance and taxonomic composition of phytoplankton algae in Gubi reservoir were carried out for 12 months (from January to December 1995). Of the 26 algal taxa identified, 14 taxa belonged to the diatoms, 8 taxa were green algae while 4 taxa belonged to the blue-green algae. Higher cell ...

Radiation effects on algae and its application

International Nuclear Information System (INIS)

Dwivedi, Rakesh Kumar

2013-01-01

The effects of radiation on algae have been summarized in this article. Today, algae are being considered to have the great potential to fulfill the demand of food, fodder, fuel and various pharmaceutical products. Red algae are particularly rich in the content of polysaccharides present in their cell wall. For isolation of these polysaccharides, separation of cells cemented together by middle lamella is essential. The gamma rays are known to bring about biochemical changes in the cell wall and cause the breakdown of the middle lamella. These rays ate also known to speed up the starch sugar inter-conversion in the cells which is very useful for the tapping the potential of algae to be used as biofuel as well as in pharmaceutical industries. Cyanobacteria, among algae and other plants are more resistant to the radiation. In some cyanobacteria the radiation treatment is known to enhance the resistance against the antibiotics. Radiation treatment is also known to enhance the diameter of cell and size of the nitrogen fixing heterocyst. (author)

Can the primary algae production be measured precisely?

International Nuclear Information System (INIS)

Olesen, M.; Lundsgaard, C.

1996-01-01

Algae production in seawater is extremely important as a basic link in marine food chains. Evaluation of the algae quantity is based on 14CO 2 tracer techniques while natural circulation and light absorption in seawater is taken insufficiently into account. Algae production can vary by 500% in similar nourishment conditions, but varying water mixing conditions. (EG)

Automation of the Weighting and its Register Using Macros; Automatizacion de la Pesada y su Registro mediante el Uso de Macro-Instrucciones

Energy Technology Data Exchange (ETDEWEB)

Gasco, C.; Ampudia, J.

2005-07-01

Macros automate a repetitive or complex task that oneself otherwise would have to execute manually. Macros have been implemented (based on Visual Basic Applications) on the laboratory calculation sheets to obtain automatically the weight-registers from the Balances. The combined utilization of the programme Balint (trademark Precisa) and macros has allowed us to transfer in real time the weight data to the sheets and later information storage. The method for using these macros has been summarised in this report. This way of working permits: to register the data of all the laboratory samples and to be available for auditory purposes. (Author) 4 refs.

Sensitivity of the green algae Chlamydomonas reinhardtii to gamma radiation: Photosynthetic performance and ROS formation

Energy Technology Data Exchange (ETDEWEB)

Gomes, Tânia, E-mail: tania.gomes@niva.no [Norwegian Institute for Water Research (NIVA), Section of Ecotoxicology and Risk Assessment, Gaustadalléen 21, N-0349, Oslo (Norway); Centre for Environmental Radioactivity, Norwegian University of Life Sciences (NMBU), Post Box 5003, N-1432 Ås (Norway); Xie, Li [Norwegian Institute for Water Research (NIVA), Section of Ecotoxicology and Risk Assessment, Gaustadalléen 21, N-0349, Oslo (Norway); Centre for Environmental Radioactivity, Norwegian University of Life Sciences (NMBU), Post Box 5003, N-1432 Ås (Norway); Brede, Dag; Lind, Ole-Christian [Centre for Environmental Radioactivity, Norwegian University of Life Sciences (NMBU), Post Box 5003, N-1432 Ås (Norway); Department for Environmental Sciences, Faculty of Environmental Science & Technology, Norwegian University of Life Sciences (NMBU), Post Box 5003, N-1432, Ås (Norway); Solhaug, Knut Asbjørn [Centre for Environmental Radioactivity, Norwegian University of Life Sciences (NMBU), Post Box 5003, N-1432 Ås (Norway); Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences (NMBU), Postbox 5003, N-1432, Ås (Norway); Salbu, Brit [Centre for Environmental Radioactivity, Norwegian University of Life Sciences (NMBU), Post Box 5003, N-1432 Ås (Norway); Department for Environmental Sciences, Faculty of Environmental Science & Technology, Norwegian University of Life Sciences (NMBU), Post Box 5003, N-1432, Ås (Norway); and others

2017-02-15

Highlights: • Chlorophyll fluorescence parameters affected at higher dose rates. • Changes in PSII associated with electron transport and energy dissipation pathways. • Dose-dependent ROS production in algae exposed to gamma radiation. • Decrease in photosynthetic efficiency connected to ROS formation. - Abstract: The aquatic environment is continuously exposed to ionizing radiation from both natural and anthropogenic sources, making the characterization of ecological and health risks associated with radiation of large importance. Microalgae represent the main source of biomass production in the aquatic ecosystem, thus becoming a highly relevant biological model to assess the impacts of gamma radiation. However, little information is available on the effects of gamma radiation on microalgal species, making environmental radioprotection of this group of species challenging. In this context, the present study aimed to improve the understanding of the effects and toxic mechanisms of gamma radiation in the unicellular green algae Chlamydomonas reinhardtii focusing on the activity of the photosynthetic apparatus and ROS formation. Algal cells were exposed to gamma radiation (0.49–1677 mGy/h) for 6 h and chlorophyll fluorescence parameters obtained by PAM fluorometry, while two fluorescent probes carboxy-H{sub 2}DFFDA and DHR 123 were used for the quantification of ROS. The alterations seen in functional parameters of C. reinhardtii PSII after 6 h of exposure to gamma radiation showed modifications of PSII energy transfer associated with electron transport and energy dissipation pathways, especially at the higher dose rates used. Results also showed that gamma radiation induced ROS in a dose-dependent manner under both light and dark conditions. The observed decrease in photosynthetic efficiency seems to be connected to the formation of ROS and can potentially lead to oxidative stress and cellular damage in chloroplasts. To our knowledge, this is the first

Sensitivity of the green algae Chlamydomonas reinhardtii to gamma radiation: Photosynthetic performance and ROS formation

International Nuclear Information System (INIS)

Gomes, Tânia; Xie, Li; Brede, Dag; Lind, Ole-Christian; Solhaug, Knut Asbjørn; Salbu, Brit

2017-01-01

Highlights: • Chlorophyll fluorescence parameters affected at higher dose rates. • Changes in PSII associated with electron transport and energy dissipation pathways. • Dose-dependent ROS production in algae exposed to gamma radiation. • Decrease in photosynthetic efficiency connected to ROS formation. - Abstract: The aquatic environment is continuously exposed to ionizing radiation from both natural and anthropogenic sources, making the characterization of ecological and health risks associated with radiation of large importance. Microalgae represent the main source of biomass production in the aquatic ecosystem, thus becoming a highly relevant biological model to assess the impacts of gamma radiation. However, little information is available on the effects of gamma radiation on microalgal species, making environmental radioprotection of this group of species challenging. In this context, the present study aimed to improve the understanding of the effects and toxic mechanisms of gamma radiation in the unicellular green algae Chlamydomonas reinhardtii focusing on the activity of the photosynthetic apparatus and ROS formation. Algal cells were exposed to gamma radiation (0.49–1677 mGy/h) for 6 h and chlorophyll fluorescence parameters obtained by PAM fluorometry, while two fluorescent probes carboxy-H 2 DFFDA and DHR 123 were used for the quantification of ROS. The alterations seen in functional parameters of C. reinhardtii PSII after 6 h of exposure to gamma radiation showed modifications of PSII energy transfer associated with electron transport and energy dissipation pathways, especially at the higher dose rates used. Results also showed that gamma radiation induced ROS in a dose-dependent manner under both light and dark conditions. The observed decrease in photosynthetic efficiency seems to be connected to the formation of ROS and can potentially lead to oxidative stress and cellular damage in chloroplasts. To our knowledge, this is the first report

Isotopic Evidence of Nitrate Sources and its Relationship to Algae in the San Joaquin River, California

Science.gov (United States)

Silva, S. R.; Kendall, C.; Young, M. B.; Stringfellow, W. T.; Borglin, S. E.; Kratzer, C. R.; Dahlgren, R. A.; Schmidt, C.; Rollog, M. E.

2007-12-01

Many competing demands have been placed on the San Joaquin River including deep water shipping, use as agricultural and drinking water, transport of agricultural and urban runoff, and recreation. These long-established demands limit the management options and increase the importance of understanding the river dynamics. The relationships among sources of water, nitrate, and algae in the San Joaquin River must be understood before management decisions can be made to optimize aquatic health. Isotopic analyses of water samples collected along the San Joaquin River in 2005-2007 have proven useful in assessing these relationships: sources of nitrate, the productivity of the San Joaquin River, and the relationship between nitrate and algae in the river. The San Joaquin River receives water locally from wetlands and agricultural return flow, and from three relatively large tributaries whose headwaters are in the Sierra Nevada. The lowest nitrate concentrations occur during periods of high flow when the proportion of water from the Sierra Nevada is relatively large, reflecting the effect of dilution from the big tributaries and indicating that a large fraction of the nitrate is of local origin. Nitrogen isotopes of nitrate in the San Joaquin River are relatively high (averaging about 12 per mil), suggesting a significant source from animal waste or sewage and/or the effects of denitrification. The d15N of nitrate varies inversely with concentration, indicating that these high isotopic values are also a local product. The d15N values of nitrate from most of the local tributaries is lower than that in the San Joaquin suggesting that nitrate from these tributaries does not account for a significant fraction of nitrate in the river. The source of the non-tributary nitrate must be either small unmeasured surface inputs or groundwater. To investigate whether groundwater might be a significant source of nitrate to the San Joaquin River, groundwater samples are being collected

Microscopic Gardens: A Close Look at Algae.

Science.gov (United States)

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)

Method and apparatus for processing algae

Science.gov (United States)

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.

Bioremediation of Heavy Metal by Algae

Directory of Open Access Journals (Sweden)

Seema Dwivedi

2012-07-01

Full Text Available Instead of using mainly bacteria, it is also possible to use mainly algae to clean wastewater because many of the pollutant sources in wastewater are also food sources for algae. Nitrates and phosphates are common components of plant fertilizers for plants. Like plants, algae need large quantities of nitrates and phosphates to support their fast cell cycles. Certain heavy metals are also important for the normal functioning of algae. These include iron (for photosynthesis, and chromium (for metabolism. Because marine environments are normally scarce in these metals, some marine algae especially have developed efficient mechanisms to gather these heavy metals from the environment and take them up. These natural processes can also be used to remove certain heavy metals from the environment. The use of algae has several advantages over normal bacteria-based bioremediation processes. One major advantage in the removal of pollutants is that this is a process that under light conditions does not need oxygen. Instead, as pollutants are taken up and digested, oxygen is added while carbon dioxide is removed. Hence, phytoremediation could potentially be coupled with carbon sequestration. Additionally, because phytoremediation does not rely on fouling processes, odors are much less a problem. Microalgae, in particular, have been recognized as suitable vectors for detoxification and have emerged as a potential low-cost alternative to physicochemical treatments. Uptake of metals by living microalgae occurs in two steps: one takes place rapidly and is essentially independent of cell metabolism – “adsorption” onto the cell surface. The other one is lengthy and relies on cell metabolism – “absorption” or “intracellular uptake.” Nonviable cells have also been successfully used in metal removal from contaminated sites. Some of the technologies in heavy metal removals, such as High Rate Algal Ponds and Algal Turf Scrubber, have been justified for

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

International Nuclear Information System (INIS)

Deng Lin; Wang Hongli; Deng Nansheng

2006-01-01

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

Modeling and optimization of algae growth

NARCIS (Netherlands)

Thornton, Anthony Richard; Weinhart, Thomas; Bokhove, Onno; Zhang, Bowen; van der Sar, Dick M.; Kumar, Kundan; Pisarenco, Maxim; Rudnaya, Maria; Savcenco, Valeriu; Rademacher, Jens; Zijlstra, Julia; Szabelska, Alicja; Zyprych, Joanna; van der Schans, Martin; Timperio, Vincent; Veerman, Frits

2010-01-01

The wastewater from greenhouses has a high amount of mineral contamination and an environmentally-friendly method of removal is to use algae to clean this runoff water. The algae consume the minerals as part of their growth process. In addition to cleaning the water, the created algal bio-mass has a

Boron in Pariette Wetland Sediments, Aquatic Vegetation & Benthic Organisms

Science.gov (United States)

Vasudeva, P.; Jones, C. P.; Powelson, D.; Jacobson, A. R.

2015-12-01

The Pariette Wetlands are comprised of 20 ponds located in Utah's Uintah Basin. Boron concentration in the Pariette Wetlands have been observed to exceed the total maximum daily limit of 750 µg L-1. Considering water flow in and out of the wetlands, boron is accumulating within the wetlands where it is sorbed to sediments and bioconcentrated by wetland plant and macro invertebrates. Since boron is an avian teratogen, an estimate of boron ingestion exposure is warranted. Samples from 3 of the 23 Pariette Wetland ponds with one pond near the inlet, one near the outlet, and one in the middle were collected. Five sampling points were designated along a 100 m transect of each pond. At each sampling point duplicate (or triplicate) samples of water, sediments, benthic organisms and wetland vegetation were collected. The sediments were collected with a KB-corer and divided at depths of 0-2 cm, 2-7 cm, and 7+ cm from the sediment surface. Sample splits were sent to the USU Bug lab for identification of invertebrate species. Whenever this transect was not intercepting vegetation, 2-3 additional sample sites were identified at the pond within stands of representative vegetation where bird nests are located. The plant parts used for boron analyses will include seeds, shoot and roots of vascular plants, as well as algae or duckweeds skimmed from the surface. Samples were processed within 2 days of collection. Water samples filtered through a 0.45 μ membrane filter were analyzed for DOC, pH and ECe. The dried and washed vegetation samples were ground and stored. The benthic organisms and macro invertebrates were netted at the water surface. The dried samples were weighed, ground and stored. Samples were weighed, oven dried and reweighed. For plant and macro-invertebrate samples, a nitric and hydrogen peroxide digestion procedure is used to dissolve environmentally available elements. The Hot Water extraction and DTPA-Sorbitol extraction were compared to estimate wetland plant

Complex fluids with mobile charge-regulating macro-ions

Science.gov (United States)

Markovich, Tomer; Andelman, David; Podgornik, Rudi

2017-10-01

We generalize the concept of charge regulation of ionic solutions, and apply it to complex fluids with mobile macro-ions having internal non-electrostatic degrees of freedom. The suggested framework provides a convenient tool for investigating systems where mobile macro-ions can self-regulate their charge (e.g., proteins). We show that even within a simplified charge-regulation model, the charge dissociation equilibrium results in different and notable properties. Consequences of the charge regulation include a positional dependence of the effective charge of the macro-ions, a non-monotonic dependence of the effective Debye screening length on the concentration of the monovalent salt, a modification of the electric double-layer structure, and buffering by the macro-ions of the background electrolyte.

THE CULTURE AND ARTS ORGANIZATION: MACRO-SOCIOLOGICAL ASPECT

Directory of Open Access Journals (Sweden)

Margarita Rasimovna Pashaeva

2013-11-01

Full Text Available In this study we analyze the macro-sociological aspect of culture and arts organization. The subject of research is reputation policy and communication technologies in  macro-sociological aspect of culture and arts organization. The target is the research the effects of macro-sociological aspect in the activities of such organization. In the study were used such methods of research: theoretical study and  synthesis; quantative method of elicitation: questionnaire; information processing methods of primary analysis; interpretation. The results of research can be applied in the activities of different culture and arts organization. The research identified the negative and positive tendencies in the context of the macro-sociological aspect.DOI: http://dx.doi.org/10.12731/2218-7405-2013-8-49

A study of the flora of aquatic habitats in East and West of Mazandaran province, Iran

Directory of Open Access Journals (Sweden)

Samaneh Tavakoli

2013-09-01

Full Text Available To judge and to evaluate the ecological characteristics of a region, vegetation is of prime importance. In fact, it reflects the biological reactions against the environmental conditions, plant evolution process and geographical condition of the past. The purpose of this study was to collect and identify aquatic plants of the East and the West of Mazandaran province. Therefore, sampling sites viz. stagnant water stops and irrigated farms were selected, marked out on the map and the specimens were collected. The collected plants were identified using different references in the Herbarium of Nowshahr Botanical Garden as well as Herbarium of Research Institute of Plant Science, Ferdowsi University of Mashhad. In this survey, a total of 126 aquatic plant species, belonging to 44 families were recognized. Among them, 56 species of Dicotyledones, 63 species of Monocotyledones, 4 species of Pteridophytes, 1 species of algae and 2 species of bryophytes were reported. Chorological studies showed that most of the species belonged to the Euro-Siberian, Mediterranean, Irano-Turanian (triregional and the rest to Pluriregional and Cosmopolitan phytochoria.

Trend in coral-algal phase shift in the Mandapam group of islands, Gulf of Mannar Marine Biosphere Reserve, India

Science.gov (United States)

Machendiranathan, M.; Senthilnathan, L.; Ranith, R.; Saravanakumar, A.; Thangaradjou, T.; Choudhry, S. B.; Sasamal, S. K.

2016-12-01

The present study revealed proliferation of macro-algae modifying coral reef ecosystems in a different manner due to diseases and sedimentations in the Mandapam group of islands in the Gulf of Mannar. Benthic surveys were conducted with major attack of seven coral reefs diseases with high sedimentation rate, nine species of fleshy macro-algae ( Turbinaria ornata, Turbinaria conaides, Caulerpa scalpelliformis, Caulerpa racemosa, Kappaphycus alvarezii, Padina gymnosphora, Sargassum wightii, Ulva reticulata and Calurpa lentillifera) proliferation against major corals life forms (Acropora branching, Acropora digitate, Acropora tabulate, coral massive, coral submassive, coral foliose and coral encrusting). The results confirm that diseased corals most favor to macro-algae growth (15.27%) rather than the sedimentation covered corals (8.24 %). In the degradation of coral life forms, massive corals were more highly damaged (7.05%) than any other forms. Within a short period of time (May to September), coral coverage shrank to 17.4% from 21.9%, macro-algae increased 23.51% and the average sedimentation rate attained 77.52 mg cm-2d-1 with persisting coral reef diseases of 17.59%. The Pearson correlation showed that the coral cover decreased with increasing macro-algae growth, which was statistically significant ( r = -0.774, n = 100, P K. alvarezii, P. gymnosphora and C. lentillifera increased with percentages of 6.0, 5.8, 5.7, 4.9, 4.2, 3.7, 2.7 and 1.9, respectively. If this trend continues, the next generation of new recruit corals will undoubtedly lead to a phase shift in Gulf of Mannar corals.

Eutrophication in Poyang Lake (Eastern China) over the Last 300 Years in Response to Changes in Climate and Lake Biomass.

Science.gov (United States)

Liao, Mengna; Yu, Ge; Guo, Ya

2017-01-01

Poyang Lake is suffering from persistent eutrophication, which is degrading the local ecosystem. A better understanding of the mechanisms that drive eutrophication in lake systems is essential to fight the ongoing deterioration. In this study, hydraulic residence time (HRT) was used to evaluate Poyang Lake's trophic state. A hydrology and ecosystem forced model was constructed to simulate long-term changes in algae and aquatic plant biomass and total phosphorous (TP). A comparison analysis revealed that between 1812 and 1828 (i.e., a consistent-change stage), climate and hydrology were the main driving forces, while algae and aquatic plant biomass contributed only 20.9% to the trophic changes in Poyang Lake. However, between 1844 and 1860 the biomass predominated contributing 63.6%. This could be attributed to nutrient absorption by algae and aquatic plants. A correlation analysis of the water TP and algae and aquatic plant biomass revealed a strong positive relationship. However, the algae and aquatic plant growth rate tended to decline after the biomass reached half of the maximum. This research reconstructs the long-term trophic evolution of Poyang Lake and provides a better understanding of the relationship between climatic and hydrological changes and lake ecosystems.

Three hitherto unreported macro-fungi from Kashmir Himalaya

International Nuclear Information System (INIS)

Pala, S.A.; Wana, A.H.; Boda, R.H.

2012-01-01

The Himalayan state, Jammu and Kashmir due to its climate ranging from tropical deciduous forests to temperate and coniferous forests provides congenial habitat for the growth of diverse macro fungal species which in turn gives it the status of 'hub' of macro-fungal species. The macro fungal species richness of the state is directly related to its expansive forest communities and diverse weather patterns, but all the regions of the state have not been extensively surveyed till now. In this backdrop, a systematic survey for exploration and inventorization of macro fungal species of Western Kashmir Himalaya was undertaken during the year 2009 and 2010, which in turn resulted identification of the three species viz., Thelephora caryophyllea (Schaeff.) Pers., Coltricia cinnamomea (Pers.) Murr., and Guepinia helvelloides Fr. as new reports from the Kashmir. These species were identified on the basis of macro and microscopic characters and also the aid of taxonomic keys, field manuals, mushroom herbaria and help from expert taxonomists in the related field was taken into account. (author)

Sustaining America's Aquatic Biodiversity. Aquatic Insect Biodiversity and Conservation

OpenAIRE

Voshell, J. Reese

2005-01-01

Provides a description of the structure and appearance of aquatic insects, how they live and reproduce, the habitats they live in, how to collect them, why they are of importance, and threats to their survival; document also includes a brief illustrated summary of the eight major groups of aquatic insects and web links to more information. Part of a 12 part series on sustaining aquatic biodiversity in America.

Ammonium removal using algae-bacteria consortia: the effect of ammonium concentration, algae biomass, and light.

Science.gov (United States)

Jia, Huijun; Yuan, Qiuyan

2018-04-01

In this study, the effects of ammonium nitrogen concentration, algae biomass concentration, and light conditions (wavelength and intensity) on the ammonium removal efficiency of algae-bacteria consortia from wastewater were investigated. The results indicated that ammonium concentration and light intensity had a significant impact on nitrification. It was found that the highest ammonia concentration (430 mg N/L) in the influent resulted in the highest ammonia removal rate of 108 ± 3.6 mg N/L/days, which was two times higher than the influent with low ammonia concentration (40 mg N/L). At the lowest light intensity of 1000 Lux, algae biomass concentration, light wavelength, and light cycle did not show a significant effect on the performance of algal-bacterial consortium. Furthermore, the ammonia removal rate was approximately 83 ± 1.0 mg N/L/days, which was up to 40% faster than at the light intensity of 2500 Lux. It was concluded that the algae-bacteria consortia can effectively remove nitrogen from wastewater and the removal performance can be stabilized and enhanced using the low light intensity of 1000 Lux that is also a cost-effective strategy.

Macro-economic Impact Study for Bio-based Malaysia

NARCIS (Netherlands)

Meijl, van H.; Smeets, E.M.W.; Dijk, van M.; Powell, J.P.; Tabeau, A.A.

2012-01-01

This Macro-economic Impact Study (MES) provides quantitative insights into the macro-economic effects of introducing green, palmbased alternatives for electricity, fuels, chemicals and materials industries in Malaysia between now and 2030.

Accumulation of 210Po by benthic marine algae

International Nuclear Information System (INIS)

Gouvea, R.C.; Branco, M.E.C.; Santos, P.L.

1988-01-01

The accumulation of polonium 210 Po by various species of benthic marine seaweeds collected from 4 different points on the coast of Rio de Janeiro, showed variations by species and algal groups. The highest value found was in red alga, Plocamium brasiliensis followed by other organisms of the same group. In the group of the brown alga, the specie Sargassum stenophylum was outstanding. The Chlorophyta presented the lowest content of 210 Po. The algae collected in open sea, revealed greater concentration factors of 210 Po than the same species living in bays. The siliceous residue remaining after mineralization of the algae did not interfere with the detection of polonium. (author)

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

Energy Technology Data Exchange (ETDEWEB)

Deng Lin [School of Resources and Environmental Science, Wuhan University, Wuhan 430072 (China); Wang Hongli [School of Resources and Environmental Science, Wuhan University, Wuhan 430072 (China); Deng Nansheng [School of Resources and Environmental Science, Wuhan University, Wuhan 430072 (China)]. E-mail: nsdengwhu@163.com

2006-11-16

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

New methodologies for integrating algae with CO2 capture

NARCIS (Netherlands)

Hernandez Mireles, I.; Stel, R.W. van der; Goetheer, E.L.V.

2014-01-01

It is generally recognized, that algae could be an interesting option for reducing CO2 emissions. Based on light and CO2, algae can be used for the production various economically interesting products. Current algae cultivation techniques, however, still present a number of limitations. Efficient

Radiation sterilization of harmful algae in water

International Nuclear Information System (INIS)

Byung Chull An; Jae-Sung Kim; Seung Sik Lee; Shyamkumar Barampuram; Eun Mi Lee; Byung Yeoup Chung

2007-01-01

Complete text of publication follows. Objective: Drinking water, water used in food production and for irrigation, water for fish farming, waste water, surface water, and recreational water have been recently recognized as a vector for the transmission of harmful micro-organisms. The human and animal harmful algae is a waterborne risk to public health and economy because the algae are ubiquitous and persistent in water and wastewater, not completely removed by physical-chemical treatment processes, and relatively resistant to chemical disinfection. Gamma and electron beam radiation technology is of growing in the water industry since it was demonstrated that gamma and electron beam radiation is very effective against harmful algae. Materials and Methods: Harmful algae (Scenedesmus quadricauda(Turpin) Brebisson 1835 (AG10003), Chlorella vulgaris Beijerinck 1896 (AG30007) and Chlamydomonas sp. (AG10061)) were distributed from Korean collection for type cultures (KCTC). Strains were cultured aerobically in Allen's medium at 25□ and 300 umol/m2s for 1 week using bioreactor. We investigated the disinfection efficiency of harmful algae irradiated with gamma (0.05 to 10 kGy for 30 min) and electron beam (1 to 19 kGy for 5 sec) rays. Results and Conclusion: We investigated the disinfection efficiency of harmful algae irradiated with gamma and electron beam rays of 50 to 19000 Gy. We established the optimum sterilization condition which use the gamma and electron beam radiation. Gamma ray disinfected harmful algae at 400 Gy for 30 min. Also, electron beam disinfected at 1000 Gy for 5 sec. This alternative disinfection practice had powerful disinfection efficiency. Hence, the multi-barrier approach for drinking water treatment in which a combination of various disinfectants and filtration technologies are applied for removal and inactivation of different microbial pathogens will guarantee a lower risk of microbial contamination.

Indigenous algae: Potential factories for biodiesel production

CSIR Research Space (South Africa)

Maharajh, Dheepak M

2008-11-01

Full Text Available advantages. Approximately 30% of South African environments favourable for isolating algae have been sampled. Samples were enriched, purified and assessed for lipid content, resulting in a database of indigenous algae. Positive isolates were grown under...

Toxicity and mode of action of tritium alone and mixed with copper on the green algae Chlamydomonas reinhardtii

International Nuclear Information System (INIS)

Rety, Celine

2010-01-01

Liquid releases by Nuclear Power Plants (NPP) are composed of a mixture of radioactive and non-radioactive substances. When organisms are exposed to mixtures of contaminants the resultant toxicity can be enhanced, or reduced, due to interactions. In order to identify potential interactions between substances released by NPP, two substances representative of such effluents (in term of toxicity and of quantity) were selected for studies: Tritiated water (HTO) and copper (Cu). Effects of this binary mixture were studied on the unicellular green algae Chlamydomonas reinhardtii. HTO, when examined along, was not very toxic to C. reinhardtii. The most sensitive and early effect of HTO was an increase in oxidative stress at concentrations of 40 kBq mL -1 (0.13 μGy h -1 ). Algae exposure to the binary mixture HTO/Cu induced interactive effects on oxidative stress. Reactive Oxygen Species production was higher from exposure to the mixture of contaminants than the addition of the effect from each substance individually. This interaction was explained by an enhanced copper uptake by the algae when in the presence of HTO. The observed supra-additive effect could also be due to direct toxic interactions, especially on the antioxidant system. To conclude, this study showed that the effects of a mixture of radioactive and nonradioactive substances can be greater than what would be predicted based on mere addition of individual effects. Even thought this binary mixture is just a small part of NPP effluents, the study showed that potential interactions should be considered when determining ecological risks to aquatic ecosystems from NPP effluents. (author)

Phospholipids of New Zealand Edible Brown Algae.

Science.gov (United States)

Vyssotski, Mikhail; Lagutin, Kirill; MacKenzie, Andrew; Mitchell, Kevin; Scott, Dawn

2017-07-01

Edible brown algae have attracted interest as a source of beneficial allenic carotenoid fucoxanthin, and glyco- and phospholipids enriched in polyunsaturated fatty acids. Unlike green algae, brown algae contain no or little phosphatidylserine, possessing an unusual aminophospholipid, phosphatidyl-O-[N-(2-hydroxyethyl) glycine], PHEG, instead. When our routinely used technique of 31 P-NMR analysis of phospholipids was applied to the samples of edible New Zealand brown algae, a number of signals corresponding to unidentified phosphorus-containing compounds were observed in total lipids. NI (negative ion) ESI QToF MS spectra confirmed the presence of more familiar phospholipids, and also suggested the presence of PHEG or its isomers. The structure of PHEG was confirmed by comparison with a synthetic standard. An unusual MS fragmentation pattern that was also observed prompted us to synthesise a number of possible candidates, and was found to follow that of phosphatidylhydroxyethyl methylcarbamate, likely an extraction artefact. An unexpected outcome was the finding of ceramidephosphoinositol that has not been reported previously as occurring in brown algae. An uncommon arsenic-containing phospholipid has also been observed and quantified, and its TLC behaviour studied, along with that of the newly synthesised lipids.

Biological toxicity of lanthanide elements on algae.

Science.gov (United States)

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. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Macro-economic impact of loss of health; Macro-economische impact van gezondheidsverlies

Energy Technology Data Exchange (ETDEWEB)

Franchimon, F. [BAM Techniek, Capelle a/d IJssel (Netherlands); Ament, H.J.A. [Universiteit Maastricht, Maastricht (Netherlands); Knies, J.; Pernot, C.E.E. [Pernot Consulting, Heeze (Netherlands); Van Bronswijk, J.M.H. [Technische Universiteit Eindhoven TUE, Eindhoven (Netherlands)

2010-11-15

More healthy life years are achievable by dwelling improvements. This article computes the healthy life years that may be gained by increased ventilation rates. It concerns the diseases Asthma, COPD en lung cancer. Increased ventilation removes house dust mites and their allergens, as well as tobacco smoke, which are associated with these diseases. Costs and savings are computes and compared in order to test the macro-economical feasibility of increased ventilation in dwellings. [Dutch] Door verbetering van woningen zijn veel gezonde levensjaren te behalen. In dit artikel worden de gewonnen gezonde levensjaren uitgerekend door meer ventileren voor de ziekten astma, COPD en longkanker. Zowel huisstofmijtallergeen als tabaksrook zijn geassocieerd met astma, COPD en longkanker. De kosten en de opbrengsten van meer ventileren worden met elkaar vergeleken om de macro-economische haalbaarheid te toetsen.

Assessing exposure risks for aquatic organisms posed by Tamiflu use under seasonal influenza and pandemic conditions

International Nuclear Information System (INIS)

Chen, Wei-Yu; Lin, Chia-Jung; Liao, Chung-Min

2014-01-01

Environmental pollution by anti-influenza drugs is increasingly recognized as a threat to aquatic environments. However, little is known about empirical data on risk effects posed by environmentally relevant concentrations of anti-influenza drug based on recently published ecotoxicological researches in Taiwan. Here we linked ecotoxicology models with an epidemiological scheme to assess exposure risks of aquatic organisms and environmental hazards posed by antiviral oseltamivir (Tamiflu) use in Taiwan. Built on published bioassays, we used probabilistic risk assessment model to estimate potential threats of environmentally relevant hazards on algae, daphnid, and zerbrafish. We found that Tamiflu use was unlikely to pose a significant chronic environmental risk to daphnia and zebrafish during seasonal influenza. However, the chronic environmental risk posed by Tamiflu use during pandemic was alarming. We conclude that no significant risk to algal growth was found during seasonal influenza and high pandemic Tamiflu use. -- Highlights: • Environmentally relevant concentrations of anti-influenza drug have ecotoxicologically important effects. • Tamiflu is unlikely to pose a significant chronic environmental risk during seasonal influenza. • Chronic environmental risk posed by Tamiflu during pandemic is alarming. • Tertiary process in sewage treatment plants is crucial in mitigating Tamiflu exposure risk. -- A probabilistic framework can be used for assessing exposure risks posed by environmentally relevant concentrations of anti-influenza drug in aquatic ecosystems

Scenario studies for algae production

OpenAIRE

Slegers, P.M.

2014-01-01

Microalgae are a promising biomass for the biobased economy to produce food, feed, fuel, chemicals and materials. So far, large-scale production of algae is limited and as a result estimates on the performance of such large systems are scarce. There is a need to estimate large-scale biomass productivity and energy consumption, while considering the uncertainty and complexity in such large-scale systems. In this thesis frameworks are developed to assess 1) the productivity during algae culti...

Aquatic insects as the main food resource of fish the community in a Neotropical reservoir

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Ana Paula Vidotto-Magnoni

Full Text Available We evaluated the feeding of fish species of the Nova Avanhandava Reservoir, low Tietê River, São Paulo State, Brazil. Fishes were collected in two stretches of the reservoir: Santa Bárbara (14 samples and Bonito (two samples between September 2002 and March 2004, using gill and seining nets. The results of stomach contents analysis were expressed with the frequency of occurrence and gravimetric method, combined in the Alimentary Index (AI. The 20 species studied consumed 52 food items, grouped in 10 food categories: aquatic insects, terrestrial insects, crustaceans, fish, macroinvertebrates, microcrustaceans, algae, vegetal matter, detritus/sediment and scales. The aquatic insects (mainly Chironomidae, Odonata and Ephemeroptera were the most common food resources, consumed by 18 species. The diet composition of the community (species grouped indicated that the dominant food category in the diet of fishes was aquatic insects (AI = 77.6%, followed by crustaceans (AI = 7.1%. Four trophic guilds were identified according a cluster analysis (Pearson distance: insectivorous (10 species, omnivorous (4 species, detritivorous (3 species and piscivorous/carcinophagous (3 species. Despite the highest number of species, the insectivorous guild was responsible for more than 80% in captures in number and biomass (CPUEn and CPUEb. The low values of niche breadth presented by all species, along with the low values of diet overlap between species pairs indicate a high degree of food resources partitioning among species. The aquatic insects, despite being the main food resource of insectivorous fishes, also complemented the diet of other species, which demonstrate the importance of this food resource for the fish community, sustaining a high diversity, abundance and biomass of fishes.

Macro Dark Matter

CERN Document Server

Jacobs, David M; Lynn, Bryan W.

2015-01-01

Dark matter is a vital component of the current best model of our universe, $\\Lambda$CDM. There are leading candidates for what the dark matter could be (e.g. weakly-interacting massive particles, or axions), but no compelling observational or experimental evidence exists to support these particular candidates, nor any beyond-the-Standard-Model physics that might produce such candidates. This suggests that other dark matter candidates, including ones that might arise in the Standard Model, should receive increased attention. Here we consider a general class of dark matter candidates with characteristic masses and interaction cross-sections characterized in units of grams and cm$^2$, respectively -- we therefore dub these macroscopic objects as Macros. Such dark matter candidates could potentially be assembled out of Standard Model particles (quarks and leptons) in the early universe. A combination of earth-based, astrophysical, and cosmological observations constrain a portion of the Macro parameter space; ho...

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

Science.gov (United States)

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

How to Identify and Control Water Weeds and Algae.

Science.gov (United States)

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…

Agricultural importance of algae | Abdel-Raouf | African Journal of ...

African Journals Online (AJOL)

Algae are a large and diverse group of microorganisms that can carry out photosynthesis since they capture energy from sunlight. Algae play an important role in agriculture where they are used as biofertilizer and soil stabilizers. Algae, particularly the seaweeds, are used as fertilizers, resulting in less nitrogen and ...

Effects of macro-nutrient, micro-nutrient composition and cooking conditions on in vitro digestibility of meat and aquatic dietary proteins.

Science.gov (United States)

Luo, Jiaqiang; Taylor, Cheryl; Nebl, Thomas; Ng, Ken; Bennett, Louise E

2018-07-15

Animal and aquatic meats represent important sources of dietary protein and micro-nutrients. Although red and processed meats carry some risks for human health, sensory and nutritional advantages drive meat consumption. Therefore, it is important to understand how meat processing and cooking influence healthiness. The research aim was to investigate relationships of meat composition (proximates, amino acids and minerals) and cooking conditions (raw, 90 s microwave, 200 °C oven for 10 or 30 min) on protein digestibility, for a selection of four animal (beef, chicken, pork, kangaroo) and four aquatic meats (salmon, trout, prawn, oyster). Lean meats were minced before cooking followed by in vitro gastro-intestinal digestion and analysed for progress of hydrolysis, and size ranges of peptides using MALDI-TOF-MS. Correlation matrix analysis between compositional and functional parameters indicated that digestibility was significantly linked with protein and metal concentrations, likely reflecting moisture-dependent solubility and inter-mixing of sarcoplasmic metallo-proteins and insoluble myofibrillar proteins. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

Isoprenoid biosynthesis in eukaryotic phototrophs: A spotlight on algae

Energy Technology Data Exchange (ETDEWEB)

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.

Effects of TiO2 nanoparticles on the growth and metabolism of three species of freshwater algae

Science.gov (United States)

Cardinale, Bradley J.; Bier, Raven; Kwan, Courtney

2012-08-01

We examined how TiO2 nanoparticles ( nTiO2) impact the growth and metabolism of three species of freshwater green algae ( Scenedesmus quadricauda, Chlamydomonas moewusii, and Chlorella vulgaris) that are widespread throughout North America. We exposed laboratory cultures to five initial concentrations of nTiO2 (0, 50, 100, 200, and 300 ppm) and measured impacts on species population growth rates, as well as on metabolic rates of gross primary production (GPP) and respiration ( R). Population growth rates were consistently reduced by nTiO2, with reduction ranging from 11 to 27 % depending on the species. But the mechanisms of reduction differed among species. For Chlamydomonas, nTiO2 reduced both GPP and R, but effects on GPP were stronger. As a consequence, carbon was respired more quickly than it was fixed, leading to reduced growth. In contrast, nTiO2 stimulated both GPP and R in Chorella. But because R was stimulated to a greater extent than GPP, carbon loss again exceeded fixation, leading to reduced growth. For Scenedesmus, nTiO2 had no significant impact on R, but reduced GPP. This pattern also caused carbon loss to exceed fixation. Results suggest that nTiO2 may generally suppress the growth of pelagic algae, but these impacts are manifest through contrasting effects on species-specific metabolic functions. Because growth and metabolism of algae are fundamental to the functioning of ecosystems and the structure of aquatic food-webs, our study suggests nTiO2 has potential to alter important community and ecosystem properties of freshwater habitats.

Effects of TiO2 nanoparticles on the growth and metabolism of three species of freshwater algae

International Nuclear Information System (INIS)

Cardinale, Bradley J.; Bier, Raven; Kwan, Courtney

2012-01-01

We examined how TiO 2 nanoparticles (nTiO 2 ) impact the growth and metabolism of three species of freshwater green algae (Scenedesmus quadricauda, Chlamydomonas moewusii, and Chlorella vulgaris) that are widespread throughout North America. We exposed laboratory cultures to five initial concentrations of nTiO 2 (0, 50, 100, 200, and 300 ppm) and measured impacts on species population growth rates, as well as on metabolic rates of gross primary production (GPP) and respiration (R). Population growth rates were consistently reduced by nTiO 2 , with reduction ranging from 11 to 27 % depending on the species. But the mechanisms of reduction differed among species. For Chlamydomonas, nTiO 2 reduced both GPP and R, but effects on GPP were stronger. As a consequence, carbon was respired more quickly than it was fixed, leading to reduced growth. In contrast, nTiO 2 stimulated both GPP and R in Chorella. But because R was stimulated to a greater extent than GPP, carbon loss again exceeded fixation, leading to reduced growth. For Scenedesmus, nTiO 2 had no significant impact on R, but reduced GPP. This pattern also caused carbon loss to exceed fixation. Results suggest that nTiO 2 may generally suppress the growth of pelagic algae, but these impacts are manifest through contrasting effects on species-specific metabolic functions. Because growth and metabolism of algae are fundamental to the functioning of ecosystems and the structure of aquatic food-webs, our study suggests nTiO 2 has potential to alter important community and ecosystem properties of freshwater habitats.

21 CFR 73.185 - Haematococcus algae meal.

Science.gov (United States)

2010-04-01

... stabilized color additive mixture. Color additive mixtures for fish feed use made with haematococcus algae... in color additive mixtures for coloring foods. (b) Specifications. Haematococcus algae meal shall... salmonid fish in accordance with the following prescribed conditions: (1) The color additive is used to...

Bruce nuclear power development (BNPD) postoperational aquatic studies

International Nuclear Information System (INIS)

Carey, W.E.

1984-01-01

This report summarizes the results of three years of postoperational aquatic study conducted between 1979 and 1981 at the Bruce Nuclear Power Development site. An increase in the rate of organic and inorganic sedimentation during the summer was noted, and was possibly related to construction activity at the Bruce GS 'B' intake site. Vertical thermal stratification persisted later in the year at the 7 m contour of Bruce GS 'A' discharge than at other locations sampled. Water quality conditions reflected the oliogtrophic state of Lake Huron. Several changes were noted in the biotic community. The taxonomic composition of attached algae, zooplankton and benthic macroinvertebrates varied between sampling years. The number of common naids, amphipods and the trichopteran Cheumatopsyche increased substantially in the 1981 rock cage collections. The relative abundance of adult walleye, channel catfish and round whitefish in gill nets increased, with the former two species being more abundant (15 fish per net in September, 1980, and 33 fish per net in July, 1981, respectively) at the 3 m contour of the Bruce GS 'A' discharge transect than at other shoreline sampling locations

Heavy metal removal from aqueous solutions using engineered magnetic biochars derived from waste marine macro-algal biomass.

Science.gov (United States)

Son, Eun-Bi; Poo, Kyung-Min; Chang, Jae-Soo; Chae, Kyu-Jung

2018-02-15

Despite the excellent sorption ability of biochar for heavy metals, it is difficult to separate and reuse after adsorption when applied to wastewater treatment process. To overcome these drawbacks, we developed an engineered magnetic biochar by pyrolyzing waste marine macro-algae as a feedstock, and we doped iron oxide particles (e.g., magnetite, maghemite) to impart magnetism. The physicochemical characteristics and adsorption properties of the biochar were evaluated. When compared to conventional pinewood sawdust biochar, the waste marine algae-based magnetic biochar exhibited a greater potential to remove heavy metals despite having a lower surface area (0.97m 2 /g for kelp magnetic biochar and 63.33m 2 /g for hijikia magnetic biochar). Although magnetic biochar could be effectively separated from the solution, however, the magnetization of the biochar partially reduced its heavy metal adsorption efficiency due to the biochar's surface pores becoming plugged with iron oxide particles. Therefore, it is vital to determine the optimum amount of iron doping that maximizes the biochar's separation without sacrificing its heavy metal adsorption efficiency. The optimum concentration of the iron loading solution for the magnetic biochar was determined to be 0.025-0.05mol/L. The magnetic biochar's heavy metal adsorption capability is considerably higher than that of other types of biochar reported previously. Further, it demonstrated a high selectivity for copper, showing two-fold greater removal (69.37mg/g for kelp magnetic biochar and 63.52mg/g for hijikia magnetic biochar) than zinc and cadmium. This high heavy metal removal performance can likely be attributed to the abundant presence of various oxygen-containing functional groups (COOH and OH) on the magnetic biochar, which serve as potential adsorption sites for heavy metals. The unique features of its high heavy metal removal performance and easy separation suggest that the magnetic algae biochar can potentially

Radionuclides and trace metals in eastern Mediterranean Sea algae

International Nuclear Information System (INIS)

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

Enzymological evidence for the function of a plastid-located pyruvate carboxylase in the Haptophyte alga Emiliania huxleyi: a novel pathway for the production of C4 compounds.

Science.gov (United States)

Tsuji, Yoshinori; Suzuki, Iwane; Shiraiwa, Yoshihiro

2012-06-01

Pyruvate carboxylase (PYC) catalyzes the β-carboxylation of pyruvate to yield oxaloacetate (OAA). We previously isolated a cDNA encoding a putative PYC (EhPYC1) from the haptophyte alga Emiliania huxleyi and then proposed that EhPYC1 contributes to active anaplerotic β-carboxylation during photosynthesis although PYC activity was not detected in the cell extracts. Involvement of PYC in photosynthetic carbon metabolism is unique, since PYC generally functions in non-photosynthetic organisms. In the present study, we demonstrate that EhPYC1 is highly sensitive to endogenous proteases and therefore is easily degraded in cell extracts. By avoiding proteolytic degradation, PYC activity can be detected in the cell extracts of E. huxleyi. The activity of a recombinant His-tagged EhPYC1 expressed in Streptomyces lividans was inhibited by l-malate in a mixed non-competitive manner. Immunofluorescence labeling showed that EhPYC1 is located in the plastid. This result agrees with the prediction that a bipartite plastid-targeting signal is present that functions to deliver proteins into the four-membrane plastid of haptophyte algae. This is the first finding of a plastid-located PYC. These results indicate that E. huxleyi possesses a unique pathway to produce OAA catalyzed by PYC, and the pathway may provide carbon skeletons for amino acid biosynthesis in the plastid. A database search indicates that PYC genes are widespread in green algae, diatoms and brown algae, suggesting the crucial role of PYC in various aquatic phototrophs.

EnAlgae Decision Support Toolset: model validation

NARCIS (Netherlands)

Kenny, Philip; Visser, de Chris; Skarka, Johannes; Sternberg, Kirstin; Schipperus, Roelof; Silkina, Alla; Ginnever, Naomi

2015-01-01

One of the drivers behind the EnAlgae project is recognising and addressing the need for increased availability of information about developments in applications of algae biotechnology for energy, particularly in the NW Europe area, where activity has been less intense than in other areas of the

A screening method for cardiovascular active compounds in marine algae.

Science.gov (United States)

Agatonovic-Kustrin, S; Kustrin, E; Angove, M J; Morton, D W

2018-05-18

The interaction of bioactive compounds from ethanolic extracts of selected marine algae samples, separated on chromatographic plates, with nitric/nitrous acid was investigated. The nature of bioactive compounds in the marine algae extracts was characterised using UV absorption spectra before and after reaction with diluted nitric acid, and from the characteristic colour reaction after derivatization with anisaldehyde. It was found that diterpenes from Dictyota dichotoma, an edible brown algae, and sterols from green algae Caulerpa brachypus, bind nitric oxide and may act as a nitric oxide carrier. Although the carotenoid fucoxanthin, found in all brown marine algae also binds nitric oxide, the bonds between nitrogen and the fucoxanthin molecule are much stronger. Further studies are required to evaluate the effects of diterpenes from Dictyota dichotoma and sterols from green algae Caulerpa brachypus to see if they have beneficial cardiovascular effects. The method reported here should prove useful in screening large numbers of algae species for compounds with cardiovascular activity. Copyright © 2018 Elsevier B.V. All rights reserved.

Genome Annotation and Transcriptomics of Oil-Producing Algae

Science.gov (United States)

2015-03-16

AFRL-OSR-VA-TR-2015-0103 GENOME ANNOTATION AND TRANSCRIPTOMICS OF OIL-PRODUCING ALGAE Sabeeha Merchant UNIVERSITY OF CALIFORNIA LOS ANGELES Final...2010 To 12-31-2014 4. TITLE AND SUBTITLE GENOME ANNOTATION AND TRANSCRIPTOMICS OF OIL-PRODUCING ALGAE 5a. CONTRACT NUMBER FA9550-10-1-0095 5b...NOTES 14. ABSTRACT Most algae accumulate triacylglycerols (TAGs) when they are starved for essential nutrients like N, S, P (or Si in the case of some

Thermal algae in certain radioactive springs in Japan, (3)

International Nuclear Information System (INIS)

Mifune, Masaaki; Hirose, Hiroyuki.

1982-01-01

Shikano Hot Springs are located at five km to the south of Hamamura Station on the Sanin Line in Tottori Prefecture. The water temperature and the pH of the springs are 40.2 - 61.2 0 C, and 7.5 - 7.8, respectively. They belong to simple thermals. Hamamura Hot Springs are located in the neighbourhood of Hamamura Station. The highest radon content of the hot springs is 175.1 x 10 -10 Ci/l, and the great part of the springs belong to radioactive ones. From the viewpoint of the major ionic constituents, they are also classified under weak salt springs, sulfated salt springs, and simple thermals. Regarding the habitates of the algal flora, the water temperature and the pH of the springs are 28.0 - 68.0 0 C, and 6.8 - 7.4, respectively. The thermal algae found by Ikoma and Doi at Hamamura Hot Springs were two species of Cyanophyceae. By the authors, nine species and one variety of Cyanophyceae including Ikoma and Doi's two species were newly found at Shikano and Hamamura Hot Springs. Chlorophyceous alga was not found. The dominant thermal algae of these hot springs were Mastigocladus laminosus, and the other algae which mainly consist of Oscillatoriaceous algae. From these points, it seems that the thermal algae of Shikano and Hamamura Hot Springs belong to the normal type of thermal algae, and they are different from the thermal algae of Ikeda Mineral Springs and Masutomi Hot Springs which belong to strongly radioactive springs. (author)

Non-target effects of a glyphosate-based herbicide on Common toad larvae (Bufo bufo, Amphibia) and associated algae are altered by temperature.

Science.gov (United States)

Baier, Fabian; Gruber, Edith; Hein, Thomas; Bondar-Kunze, Elisabeth; Ivanković, Marina; Mentler, Axel; Brühl, Carsten A; Spangl, Bernhard; Zaller, Johann G

2016-01-01

Glyphosate-based herbicides are the most widely used pesticides in agriculture, horticulture, municipalities and private gardens that can potentially contaminate nearby water bodies inhabited by amphibians and algae. Moreover, the development and diversity of these aquatic organisms could also be affected by human-induced climate change that might lead to more periods with extreme temperatures. However, to what extent non-target effects of these herbicides on amphibians or algae are altered by varying temperature is not well known. We studied effects of five concentrations of the glyphosate-based herbicide formulation Roundup PowerFlex (0, 1.5, 3, 4 mg acid equivalent glyphosate L -1 as a one time addition and a pulse treatment of totally 4 mg a.e. glyphosate L -1 ) on larval development of Common toads ( Bufo bufo , L.; Amphibia: Anura) and associated algae communities under two temperature regimes (15 vs. 20 °C). Herbicide contamination reduced tail growth (-8%), induced the occurrence of tail deformations (i.e. lacerated or crooked tails) and reduced algae diversity (-6%). Higher water temperature increased tadpole growth (tail and body length (tl/bl) +66%, length-to-width ratio +4%) and decreased algae diversity (-21%). No clear relation between herbicide concentrations and tadpole growth or algae density or diversity was observed. Interactive effects of herbicides and temperature affected growth parameters, tail deformation and tadpole mortality indicating that the herbicide effects are temperature-dependent. Remarkably, herbicide-temperature interactions resulted in deformed tails in 34% of all herbicide treated tadpoles at 15 °C whereas no tail deformations were observed for the herbicide-free control at 15 °C or any tadpole at 20 °C; herbicide-induced mortality was higher at 15 °C but lower at 20 °C. These herbicide- and temperature-induced changes may have decided effects on ecological interactions in freshwater ecosystems. Although no clear dose

Non-target effects of a glyphosate-based herbicide on Common toad larvae (Bufo bufo, Amphibia and associated algae are altered by temperature

Directory of Open Access Journals (Sweden)

Fabian Baier

2016-11-01

Full Text Available Background Glyphosate-based herbicides are the most widely used pesticides in agriculture, horticulture, municipalities and private gardens that can potentially contaminate nearby water bodies inhabited by amphibians and algae. Moreover, the development and diversity of these aquatic organisms could also be affected by human-induced climate change that might lead to more periods with extreme temperatures. However, to what extent non-target effects of these herbicides on amphibians or algae are altered by varying temperature is not well known. Methods We studied effects of five concentrations of the glyphosate-based herbicide formulation Roundup PowerFlex (0, 1.5, 3, 4 mg acid equivalent glyphosate L−1 as a one time addition and a pulse treatment of totally 4 mg a.e. glyphosate L−1 on larval development of Common toads (Bufo bufo, L.; Amphibia: Anura and associated algae communities under two temperature regimes (15 vs. 20 °C. Results Herbicide contamination reduced tail growth (−8%, induced the occurrence of tail deformations (i.e. lacerated or crooked tails and reduced algae diversity (−6%. Higher water temperature increased tadpole growth (tail and body length (tl/bl +66%, length-to-width ratio +4% and decreased algae diversity (−21%. No clear relation between herbicide concentrations and tadpole growth or algae density or diversity was observed. Interactive effects of herbicides and temperature affected growth parameters, tail deformation and tadpole mortality indicating that the herbicide effects are temperature-dependent. Remarkably, herbicide-temperature interactions resulted in deformed tails in 34% of all herbicide treated tadpoles at 15 °C whereas no tail deformations were observed for the herbicide-free control at 15 °C or any tadpole at 20 °C; herbicide-induced mortality was higher at 15 °C but lower at 20 °C. Discussion These herbicide- and temperature-induced changes may have decided effects on ecological

Behaviour of technetium in marine algae

International Nuclear Information System (INIS)

Bonotto, S.; Kirchmann, R.; Van Baelen, J.; Hurtger, C.; Cogneau, M.; Van der Ben, D.; Verthe, C.; Bouquegneau, J.M.

1985-01-01

Uptake and distribution of technetium were studied in several green (Acetabularia acetabulum, Boergesenia forbesii, Ulva lactuca) and brown (Ascophyllum nodosum, Fucus serratus, Fucus spiralis and Fucus vesiculosus) marine algae. Technetium was supplied to the algae as Tc-95m-pertechnetate. Under laboratory conditions, the algae were capable of accumulating technetium, with the exception, however, of Boergesenia, which showed concentration factors (C.F.) comprised between 0.28 and 0.71. The concentration of technetium-99 in Fucus spiralis, collected along the Belgian coast, was measured by a radiochemical procedure. The intracellular distribution of technetium was studied by differential centrifugation in Acetabularia and by the puncturing technique in Boergesenia. The chemical forms of technetium penetrated into the cells were investigated by selective chemical extractions, molecular sieving and thin layer chromatography

Behaviour of technetium in marine algae

International Nuclear Information System (INIS)

Bonotto, S.; Kirchmann, R.; Baelen, J. van; Hurtgen, C.; Cogneau, M.; Ben, D. van der; Verthe, C.; Bouquegneau, J.M.

1986-01-01

Uptake and distribution of technetium were studied in several green (Acetabularia acetabulum, Boergesenia forbesii, Ulva lactuca) and brown (Ascophyllum nodosum, Fucus serratus, Fucus spiralis and Fucus vesiculosus) marine algae. Technetium was supplied to the algae as Tc-95-pertechnetate. Under laboratory conditions, the algae were capable of accumulating technetium, with the exception, however, of Boergesenia, which showed concentration factors (C.F.) comprised between 0.28 and 0.71. The concentration of technetium-99 in Fucus spiralis, collected along the Belgian coast, was measured by a radiochemical procedure. The intracellular distribution of technetium was studied by differential centrifugation in Acetabularia and by the puncturing technique in Boergesenia. The chemical forms of technetium penetrated into the cells were investigated by selective chemical extractions, molecular sieving and thin layer chromatography. (author)

Eutrophication in Poyang Lake (Eastern China over the Last 300 Years in Response to Changes in Climate and Lake Biomass.

Directory of Open Access Journals (Sweden)

Mengna Liao

Full Text Available Poyang Lake is suffering from persistent eutrophication, which is degrading the local ecosystem. A better understanding of the mechanisms that drive eutrophication in lake systems is essential to fight the ongoing deterioration. In this study, hydraulic residence time (HRT was used to evaluate Poyang Lake's trophic state. A hydrology and ecosystem forced model was constructed to simulate long-term changes in algae and aquatic plant biomass and total phosphorous (TP. A comparison analysis revealed that between 1812 and 1828 (i.e., a consistent-change stage, climate and hydrology were the main driving forces, while algae and aquatic plant biomass contributed only 20.9% to the trophic changes in Poyang Lake. However, between 1844 and 1860 the biomass predominated contributing 63.6%. This could be attributed to nutrient absorption by algae and aquatic plants. A correlation analysis of the water TP and algae and aquatic plant biomass revealed a strong positive relationship. However, the algae and aquatic plant growth rate tended to decline after the biomass reached half of the maximum. This research reconstructs the long-term trophic evolution of Poyang Lake and provides a better understanding of the relationship between climatic and hydrological changes and lake ecosystems.

Interspecific variation in total phenolic content in temperate brown algae

Directory of Open Access Journals (Sweden)

Anna Maria Mannino

2017-09-01

Full Text Available Marine algae synthesize secondary metabolites such as polyphenols that function as defense and protection mechanisms. Among brown algae, Fucales and Dictyotales (Phaeophyceae contain the highest levels of phenolic compounds, mainly phlorotannins, that play multiple roles. Four temperate brown algae (Cystoseira amentacea, Cystoseira compressa, Dictyopteris polypodioides and Padina pavonica were studied for total phenolic contents. Total phenolic content was determined colorimetrically with the Folin-Ciocalteu reagent. Significant differences in total phenolic content were observed between leathery and sheetlike algae and also within each morphological group. Among the four species, the sheet-like alga D. polypodioides, living in the upper infralittoral zone, showed the highest concentration of phenolic compounds. These results are in agreement with the hypothesis that total phenolic content in temperate brown algae is influenced by a combination of several factors, such as growth form, depth, and exposition to solar radiation.

Inventario de las macroalgas dulceacuícolas y marinas de Costa Rica

OpenAIRE

Bernecker Lucking, Andrea; Morales Zurcher, María

2011-01-01

Contiene un listado sobre los diferentes grupos de algas, sobre todo las macro algas de agua dulce y marinas para aumentar la lista de especies de algas de Costa Rica. Universidad de Costa Rica UCR::Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biología

Study on the effect of irradiation on algae by proteomics

International Nuclear Information System (INIS)

Choi, Jong Il; Yoon, Yo Han; Kim, Jae Hun

2010-06-01

Algae has been utilized as food material from long time ago, and recently newly recognized as functional materials and the source of bio-fuel. But, the study on the algae is just beginning and the study on protein expression and growth by the change of condition was not reported. In this study, the effect of radiation on the protein expression was investigated for the protection mechanisms and new genome source and furthermore, isolation of new mutant strains. To monitor the growth of algae, absorbance and FDA staining methods were developed and the content of lipid of algae species were measured. With these methods, the radiation sensitivity of algae species was determined. To investigate the proteome of algae, 2D-electrophoresis methods was applied. From the comparison of proteomes, the radiation specific expressed protein was identified as thioredoxin-h and its nucleotide sequences was defined. The expression of thioredoxin-h was further defined on the mRNA level. Also, the extract of algae species was analyzed for its antioxidant activity and polyphenolic content. The changes in antioxidant activity of extract by radiation was investigated. From the radiation experiments, mutant Spirogyra species having higher resistant against radical stress was obtained. The mutant strain has higher antioxidant activity. This results can provide the proteome date and mutation technology of algae and further contribute in the activation of fishery industry and national health enhancement

Dynamic Resource Partitioning for Downlink Femto-to-Macro-Cell Interference Avoidance

Directory of Open Access Journals (Sweden)

Zubin Bharucha

2010-01-01

Full Text Available Femto-cells consist of user-deployed Home Evolved NodeBs (HeNBs that promise substantial gains in system spectral efficiency, coverage, and data rates due to an enhanced reuse of radio resources. However, reusing radio resources in an uncoordinated, random fashion introduces potentially destructive interference to the system, both, in the femto and macro layers. An especially critical scenario is a closed-access femto-cell, cochannel deployed with a macro-cell, which imposes strong downlink interference to nearby macro user equipments (UEs that are not permitted to hand over to the femto-cell. In order to maintain reliable service of macro-cells, it is imperative to mitigate the destructive femto-cell to macro-cell interference. The contribution in this paper focuses on mitigating downlink femto-cell to macro-cell interference through dynamic resource partitioning, in the way that HeNBs are denied access to downlink resources that are assigned to macro UEs in their vicinity. By doing so, interference to the most vulnerable macro UEs is effectively controlled at the expense of a modest degradation in femto-cell capacity. The necessary signaling is conveyed through downlink high interference indicator (DL-HII messages over the wired backbone. Extensive system level simulations demonstrate that by using resource partitioning, for a sacrifice of 4% of overall femto downlink capacity, macro UEs exposed to high HeNB interference experience a tenfold boost in capacity.

Effects of acute {gamma}-irradiation on community structure of the aquatic microbial microcosm

Energy Technology Data Exchange (ETDEWEB)

Fuma, Shoichi, E-mail: fuma@nirs.go.j [Environmental Radiation Effects Research Group, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Ishii, Nobuyoshi; Takeda, Hiroshi [Environmental Radiation Effects Research Group, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Doi, Kazutaka; Kawaguchi, Isao [Regulatory Sciences Research Group, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Shikano, Shuichi [Center for Northeast Asian Studies, Tohoku University, 41 Kawauchi, Aoba-ku, Sendai, Miyagi 980-8576 (Japan); Tanaka, Nobuyuki [Marine Environment Section, Water and Soil Environment Division, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506 (Japan); Inamori, Yuhei [Faculty of Symbiotic Systems Science, Fukushima University, 1 Kanayagawa, Fukushima 960-1296 (Japan)

2010-11-15

To characterise indirect effects of ionising radiation on aquatic microbial communities, effects of acute {gamma}-irradiation were investigated in a microcosm consisting of populations of green algae (Chlorella sp. and Scenedesmus sp.) and a blue-green alga (Tolypothrix sp.) as producer; a ciliate protozoan (Cyclidium glaucoma), rotifers (Lecane sp. and Philodina sp.) and an oligochaete (Aeolosoma hemprichi) as consumer; and more than four species of bacteria as decomposers. Population changes in the constituent organisms were observed over 160 days after irradiation. Prokaryotic community structure was also examined by denaturing gradient gel electrophoresis (DGGE) of 16S rDNA. Principle response curve analysis revealed that the populations of the microcosm as a whole were not significantly affected at 100 Gy while they were adversely affected at 500-5000 Gy in a dose-dependent manner. However, some effects on each population, including each bacterial population detected by DGGE, did not depend on radiation doses, and some populations in the irradiated microcosm were larger than those of the control. These unexpected results are regarded as indirect effects through interspecies interactions, and possible mechanisms are proposed originating from population changes in other organisms co-existing in the microcosm. For example, some indirect effects on consumers and decomposers likely arose from interspecies competition within each trophic level. It is also likely that prey-predator relationships between producers and consumers caused some indirect effects on producers.

Mg-lattice associations in red coralline algae

Science.gov (United States)

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

2009-04-01

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

Investigation on the distribution of tritium and carbon-14 in the amino acids of labelled green algae (Scenedesmus Quadricauda ssp.)

International Nuclear Information System (INIS)

Nuernberger, E.; Clausen, E.; Kistner, G.

1982-01-01

Green algae (Scenedesmus quadricauda ssp. subspicatus), labelled twice tritium and carbon-14, showed an incorporation of nuclides into the cell mass of 0.02% and 95%, respectively. The distribution of radioactivity in the individual amino acids was examined in a protein fraction with special emphasis on the essential amino acids in view of their following incorporation into the next link of the aquatic food chain (Daphnia). The highest values were found in glutamine and asparagine acids as well as in the essential amino acids leucine and arginine, which are amino acids with a relatively high amount of non exchangeable H-positions per molecule and, therefore, a relatively high and stable labelling. (author)

Intake of macro- and micronutrients in Danish vegans

DEFF Research Database (Denmark)

Kristensen, Nadja B; Madsen, Mia L; H Hansen, Tue

2015-01-01

Since information about macro- and micronutrient intake among vegans is limited we aimed to determine and evaluate their dietary and supplementary intake. Seventy 18-61 years old Danish vegans completed a four-day weighed food record from which their daily intake of macro- and micronutrients was ...

SAS-macros for estimation and prediction in an model of the electricity consumption

DEFF Research Database (Denmark)

1998-01-01

SAS-macros for estimation and prediction in an model of the electricity consumption'' is a large collection of SAS-macros for handling a model of the electricity consumption in the Eastern Denmark. The macros are installed at Elkraft, Ballerup.......SAS-macros for estimation and prediction in an model of the electricity consumption'' is a large collection of SAS-macros for handling a model of the electricity consumption in the Eastern Denmark. The macros are installed at Elkraft, Ballerup....

Scaling up: Assessing social impacts at the macro-scale

International Nuclear Information System (INIS)

Schirmer, Jacki

2011-01-01

Social impacts occur at various scales, from the micro-scale of the individual to the macro-scale of the community. Identifying the macro-scale social changes that results from an impacting event is a common goal of social impact assessment (SIA), but is challenging as multiple factors simultaneously influence social trends at any given time, and there are usually only a small number of cases available for examination. While some methods have been proposed for establishing the contribution of an impacting event to macro-scale social change, they remain relatively untested. This paper critically reviews methods recommended to assess macro-scale social impacts, and proposes and demonstrates a new approach. The 'scaling up' method involves developing a chain of logic linking change at the individual/site scale to the community scale. It enables a more problematised assessment of the likely contribution of an impacting event to macro-scale social change than previous approaches. The use of this approach in a recent study of change in dairy farming in south east Australia is described.

Effects of TiO{sub 2} nanoparticles on the growth and metabolism of three species of freshwater algae

Energy Technology Data Exchange (ETDEWEB)

Cardinale, Bradley J., E-mail: bradcard@umich.edu [University of Michigan, School of Natural Resources and Environment (United States); Bier, Raven [Duke University, Department of Biology (United States); Kwan, Courtney [Evolution and Marine Biology, University of California, Department of Ecology (United States)

2012-08-15

We examined how TiO{sub 2} nanoparticles (nTiO{sub 2}) impact the growth and metabolism of three species of freshwater green algae (Scenedesmus quadricauda, Chlamydomonas moewusii, and Chlorella vulgaris) that are widespread throughout North America. We exposed laboratory cultures to five initial concentrations of nTiO{sub 2} (0, 50, 100, 200, and 300 ppm) and measured impacts on species population growth rates, as well as on metabolic rates of gross primary production (GPP) and respiration (R). Population growth rates were consistently reduced by nTiO{sub 2}, with reduction ranging from 11 to 27 % depending on the species. But the mechanisms of reduction differed among species. For Chlamydomonas, nTiO{sub 2} reduced both GPP and R, but effects on GPP were stronger. As a consequence, carbon was respired more quickly than it was fixed, leading to reduced growth. In contrast, nTiO{sub 2} stimulated both GPP and R in Chorella. But because R was stimulated to a greater extent than GPP, carbon loss again exceeded fixation, leading to reduced growth. For Scenedesmus, nTiO{sub 2} had no significant impact on R, but reduced GPP. This pattern also caused carbon loss to exceed fixation. Results suggest that nTiO{sub 2} may generally suppress the growth of pelagic algae, but these impacts are manifest through contrasting effects on species-specific metabolic functions. Because growth and metabolism of algae are fundamental to the functioning of ecosystems and the structure of aquatic food-webs, our study suggests nTiO{sub 2} has potential to alter important community and ecosystem properties of freshwater habitats.

Les algues sont-elles une ressource marine à exploiter pour développer durablement l’espace caribéen ? Can algae be a sea resource to be exploited to have a sustainable development of Caribbean?

Directory of Open Access Journals (Sweden)

Sophie Litzler

2010-12-01

Full Text Available L’algue est une ressource marine peu étudiée par la géographie ; elle offre pourtant des potentialités de développement économique. Les macro-algues cultivées à des fins alimentaires sont une alternative à la pêche. Les micro-algues constituent une biomasse valorisable : molécule pharmaceutique, Oméga 3 et biocarburants. De ces différents usages naît la question suivante : les algues sont-elles une ressource marine à exploiter pour développer durablement les territoires de la zone intertropicale ? Nous présenterons tout d’abord l’algoculture à l’échelle mondiale en soulignant le faible poids de cette activité dans le bassin caribéen. Puis nous montrerons que l’algoculture s’inscrit dans un processus de développement durable en assurant un revenu à des communautés rurales (Petites Antilles. Enfin, dans une approche comparative (États-Unis, nous verrons que l’espace caribéen est une région de projets et d’aménagements durables qui a des atouts pour développer l’algoculture : exposition solaire, hautes températures, proximité de la recherche américaine.Algae as sea resource have not been largely explored in Geography, yet it offers the potential for economic development. Macro-algae are cultivated for food purposes and they can substitute for fishing. Micro-algae can be valued as biomass: “nutraceutics”, Omega 3, biofuel. These various utilizations raise a question: are algae a key to a sustainable development in intertropical islands? We shall present Algaculture on a global scale, while emphasizing its low importance in the Caribbean. Then we shall show how algaculture can be part of a process of sustainable development by providing revenue to rural communities (Lesser Antilles. Finally, in a comparative approach (with the US, we shall see that the Caribbean Region has a number of assets for algaculture that make it suitable for sustainable projects and infrastructures: solar exposure

Green Algae and the Origins of Multicellularity in the Plant Kingdom

Science.gov (United States)

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

Are anti-fouling effects in coralline algae species specific?

Directory of Open Access Journals (Sweden)

Alexandre Bigio Villas Bôas

2004-03-01

Full Text Available The crustose coralline algae are susceptible to be covered by other algae, which in turn can be affected by anti-fouling effects. In this study the hypothesis tested was that these algae can inhibit the growth of epiphytes in a species specific way. In the laboratory, propagules of Sargassum furcatum and Ulva fasciata were liberated and cultivated on pieces of coralline algae and slide covers (controls and their survival and growth were compared. Spongites and Hydrolithon significantly inhibited the growth of U. fasciata but not Sargassum. In the field, pieces of three species of live and dead coralline algae and their copies in epoxy putty discs were fixed on the rock. After one month epiphytic algae were identified and their dry mass quantified. Lithophyllum did not affect the epiphyte growth. In contrast Spongites and an unidentified coralline significantly inhibited the growth of Enteromorpha spp., Ulva fasciata and Hincksia mitchelliae. Colpomenia sinuosa was absent on all living crusts, but present on controls. Results show that the epiphyte-host relation depends on the species that are interacting. The sloughing of superficial cells of coralline crusts points to the possible action of physical anti-fouling effect, though a chemical one is not rejected.As algas calcárias crostosas são susceptíveis ao recobrimento por outras algas, entretanto, estas podem ser afetadas por efeitos anti-incrustantes. Neste estudo foi testada a hipótese de que estas algas possam inibir o crescimento somente de algumas espécies de epífitas. No laboratório, propágulos de Sargassum furcatum e Ulva fasciata foram liberados e cultivados sobre pedaços de algas calcárias e lamínulas de microscopia (controle e as suas sobrevivência e crescimento comparadas. Spongites e Hydrolithon inibiram significativamente o crescimento de U. fasciata, mas não de Sargassum. No campo, pedaços de três espécies de algas calcárias vivas, mortas e cópias destas em

Bio diesel production from algae

International Nuclear Information System (INIS)

Khola, G.; Ghazala, B.

2011-01-01

Algae appear to be an emerging source of biomass for bio diesel that has the potential to completely displace fossil fuel. Two thirds of earth's surface is covered with water, thus alga e would truly be renewable option of great potential for global energy needs. This study discusses specific and comparative bio diesel quantitative potential of Cladophora sp., also highlighting its biomass (after oil extraction), pH and sediments (glycerine, water and pigments) quantitative properties. Comparison of Cladophora sp., with Oedogonium sp., and Spirogyra sp., (Hossain et al., 2008) shows that Cladophora sp., produce higher quantity of bio diesel than Spirogyra sp., whereas biomass and sediments were higher than the both algal specimens in comparison to the results obtained by earlier workers. No prominent difference in pH of bio diesel was found. In Pakistan this is a first step towards bio diesel production from algae. Results indicate that Cladophora sp., provide a reasonable quantity of bio diesel, its greater biomass after oil extraction and sediments make it a better option for bio diesel production than the comparing species. (author)

Mercury analysis of acid- and alkaline-reduced biological samples: identification of meta-cinnabar as the major biotransformed compound in algae.

Science.gov (United States)

Kelly, David; Budd, Kenneth; Lefebvre, Daniel D

2006-01-01

The biotransformation of Hg(II) in pH-controlled and aerated algal cultures was investigated. Previous researchers have observed losses in Hg detection in vitro with the addition of cysteine under acid reduction conditions in the presence of SnCl2. They proposed that this was the effect of Hg-thiol complexing. The present study found that cysteine-Hg, protein and nonprotein thiol chelates, and nucleoside chelates of Hg were all fully detectable under acid reduction conditions without previous digestion. Furthermore, organic (R-Hg) mercury compounds could not be detected under either the acid or alkaline reduction conditions, and only beta-HgS was detected under alkaline and not under acid SnCl2 reduction conditions. The blue-green alga Limnothrix planctonica biotransformed the bulk of Hg(II) applied as HgCl2 into a form with the analytical properties of beta-HgS. Similar results were obtained for the eukaryotic alga Selenastrum minutum. No evidence for the synthesis of organomercurials such as CH3Hg+ was obtained from analysis of either airstream or biomass samples under the aerobic conditions of the study. An analytical procedure that involved both acid and alkaline reduction was developed. It provides the first selective method for the determination of beta-HgS in biological samples. Under aerobic conditions, Hg(II) is biotransformed mainly into beta-HgS (meta-cinnabar), and this occurs in both prokaryotic and eukaryotic algae. This has important implications with respect to identification of mercury species and cycling in aquatic habitats.

Accumulation of 95mTc by marine algae and sea urchin

International Nuclear Information System (INIS)

Nakamura, Ryoichi; Nakahara, Motokazu; Matsuba, Mitsue; Suzuki, Yuzuru

1994-01-01

It is necessary to investigate the accumulation of technetium by marine algae popular in Japan and it is also important to examine the contribution of food to the accumulation of the nuclide by sea urchin which grazes algae. In the laboratory tracer experiment, some species of algae and sea urchin were kept separately for 7 days in sea water containing 95m Tc (uptake experiment) and then transferred into non-radioactive sea water to be held for 28 days with the frequent renewal of the sea water (excretion experiment). No food was given during the uptake experiment to prevent the urchins from accumulating 95m Tc through food. Another experiment was done by feeding urchins with 95m Tc labeled algae in the non-radioactive sea water. Five species of brown algae showed CFs in the range of 900 and 35000 but CFs of green and red algae were 1-4. Sea urchin accumulated more 95m Tc through food (brown algae) than directly from sea water, so that the main pathway of technetium accumulation by sea urchin was estimated to be brown algae which were the most favorite food of the organism. (author)

Biogas performance from co-digestion of Taihu algae and kitchen wastes

International Nuclear Information System (INIS)

Zhao, Ming-Xing; Ruan, Wen-Quan

2013-01-01

Highlights: • Co-digestion mode improves the biogas yield of Taihu algae and kitchen wastes. • Neutral protease enzyme reached maximum in algae only group. • The activity of dehydrogenase enzyme in mixed substrate groups was higher than that of algae and kitchen wastes only group. - Abstract: Co-digestion of Taihu algae with high carbon content substrate can balance the nutrients in the fermentation process. In this study, optimal mixing ratio for co-digestion of Taihu algae and kitchen wastes were investigated in order to improve biogas production potential. The results indicated that the biogas yield reached 388.6 mL/gTS at C/N15:1 group, which was 1.29 and 1.18 times of algae and kitchen wastes only. The maximum concentration of VFA reached 4239 mg/L on 8th day in kitchen wastes group, which was 1.21 times of algae group. Neutral protease enzyme activity in algae group reached maximum of 904.2 μg/(gTS h), while dehydrogenase enzyme at C/N 15:1 group reached maximum of 3402.2 μgTF/(gTS h). The feasibility of adjusting the C/N with co-digestion of Taihu algae and kitchen wastes to increase biogas production was demonstrated. Remarkably, the C/N of 15:1 was found to be the most appropriate ratio

The effects of ProAlgaZyme novel algae infusion on metabolic syndrome and markers of cardiovascular health

Directory of Open Access Journals (Sweden)

Hildreth DeWall J

2007-09-01

Full Text Available Abstract Background Metabolic Syndrome, or Syndrome X, is characterized by a set of metabolic and lipid imbalances that greatly increases the risk of developing diabetes and cardiovascular disease. The syndrome is highly prevalent in the United States and worldwide, and treatments are in high demand. ProAlgaZyme, a novel and proprietary freshwater algae infusion in purified water, has been the subject of several animal studies and has demonstrated low toxicity even with chronic administration at elevated doses. The infusion has been used historically for the treatment of several inflammatory and immune disorders in humans and is considered well-tolerated. Here, the infusion is evaluated for its effects on the cardiovascular risk factors present in metabolic syndrome in a randomized double-blind placebo-controlled study involving 60 overweight and obese persons, ages 25–60. All participants received four daily oral doses (1 fl oz of ProAlgaZyme (N = 22 or water placebo (N = 30 for a total of 10 weeks, and were encouraged to maintain their normal levels of physical activity. Blood sampling and anthropometric measurements were taken at the beginning of the study period and after 4, 8 and 10 weeks of treatment. Eight participants did not complete the study. Results ProAlgaZyme brought about statistically significant (p Conclusion ProAlgaZyme (4 fl oz daily consumption resulted in significant reductions in weight and blood glucose levels, while significantly improving serum lipid profiles and reducing markers of inflammation, thus improving cardiovascular risk factors in overweight and obese subjects over a course of 10 weeks with an absence of adverse side effects. Trial Registration US ClinicalTrials.gov NCT00489333

Evaluation of vitrification factors from DWPF's macro-batch 1

International Nuclear Information System (INIS)

Edwards, T.B.

2000-01-01

The Defense Waste Processing Facility (DWPF) is evaluating new sampling and analytical methods that may be used to support future Slurry Mix Evaporator (SME) batch acceptability decisions. This report uses data acquired during DWPF's processing of macro-batch 1 to determine a set of vitrification factors covering several SME and Melter Feed Tank (MFT) batches. Such values are needed for converting the cation measurements derived from the new methods to a ''glass'' basis. The available data from macro-batch 1 were used to examine the stability of these vitrification factors, to estimate their uncertainty over the course of a macro-batch, and to provide a recommendation on the use of a single factor for an entire macro-batch. The report is in response to Technical Task Request HLW/DWPF/TTR-980015

Phycobiliproteins: A Novel Green Tool from Marine Origin Blue-Green Algae and Red Algae.

Science.gov (United States)

Chandra, Rashmi; Parra, Roberto; Iqbal, Hafiz M N

2017-01-01

Marine species are comprising about a half of the whole global biodiversity; the sea offers an enormous resource for novel bioactive compounds. Several of the marine origin species show multifunctional bioactivities and characteristics that are useful for a discovery and/or reinvention of biologically active compounds. For millennia, marine species that includes cyanobacteria (blue-green algae) and red algae have been targeted to explore their enormous potential candidature status along with a wider spectrum of novel applications in bio- and non-bio sectors of the modern world. Among them, cyanobacteria are photosynthetic prokaryotes, phylogenetically a primitive group of Gramnegative prokaryotes, ranging from Arctic to Antarctic regions, capable of carrying out photosynthesis and nitrogen fixation. In the recent decade, a great deal of research attention has been paid on the pronouncement of bio-functional proteins along with novel peptides, vitamins, fine chemicals, renewable fuel and bioactive compounds, e.g., phycobiliproteins from marine species, cyanobacteria and red algae. Interestingly, they are extensively commercialized for natural colorants in food and cosmetics, antimicrobial, antioxidant, anti-inflammatory, neuroprotective, hepatoprotective agents and fluorescent neo-glycoproteins as probes for single particle fluorescence imaging fluorescent applications in clinical and immunological analysis. However, a comprehensive knowledge and technological base for augmenting their commercial utilities are lacking. Therefore, this paper will provide an overview of the phycobiliproteins-based research literature from marine cyanobacteria and red algae. This review is also focused towards analyzing global and commercial activities with application oriented-based research. Towards the end, the information is also given on the potential biotechnological and biomedical applications of phycobiliproteins. Copyright© Bentham Science Publishers; For any queries, please

Freshwater algae of the Nevada Test Site

International Nuclear Information System (INIS)

Taylor, W.D.; Giles, K.R.

1979-06-01

Fifty-two species of freshwater algae were identified in samples collected from the eight known natural springs of the Nevada Test Site. Although several species were widespread, 29 species were site specific. Diatoms provided the greatest variety of species at each spring. Three-fifths of all algal species encountered were diatoms. Well-developed mats of filamentous green algae (Chlorophyta) were common in many of the water tanks associated with the springs and accounted for most of the algal biomass. Major nutrients were adequate, if not abundant, in most spring waters - growth being limited primarily by light and physical habitat. There was some evidence of cesium-137 bioconcentration by algae at several of the springs

Technology strategy as macro-actor

DEFF Research Database (Denmark)

Tryggestad, Kjell

2003-01-01

-human entities to the explanatory repertoire of strategy research, another line of inquiry is pursued. The performative perspective thus proposed, is inspired by the classical work of Von Clausewitz and the recent anthropology of science, technology and organizational identities. In the proposed perspective...... case account for how the strategic technology and the strategic collective emerge and co-produce each other as a macro-actor, only to become transformed in unexpected ways - as common technology and reflective human subjects.In the concluding section, it is argued that the humanity of the reflective...... outcomes, as providers of explanations and observations. The expression `technological strategy as macro-actor' summarizes these findings and the associated implications for research and practice....

Macro-institutional Complexity in Logistics

DEFF Research Database (Denmark)

Wessel, Frederic; Kinra, Aseem; Kotzab, Herbert

2016-01-01

structure and transactional costs, the concept of environmental complexity is applied to the logistics management perspective. Thereby, the impacts which a given framework on a macro-institutional level might have on the situation and leeway in decision-making at the firm (micro) or the supply chain (meso......In this paper, the interlink between the concept of macro-institutional complexity in logistics and the dynamics in the logistics practice of Eastern Europe will be examined. Referring to the importance of different authors having ascribed to the external environmental uncertainty on organizational......) levels will be analysed. Furthermore, a quantitative modelling approach will be presented and exemplified by using the case of logistics infrastructure in Eastern Europe....

Bioconcentration, bioaccumulation, and metabolism of pesticides in aquatic organisms.

Science.gov (United States)

Katagi, Toshiyuki

2010-01-01

detoxification and bioactivation. Hydrophobic pesticides that are expected to be highly stored in tissues would not be bioconcentrated if susceptible to biotic transformation by aquatic organisms to more rapidly metabolized to hydrophilic entities are generally less toxic. By analogy, pesticides that are metabolized to similar entities by aquatic species surely are les ecotoxicologically significant. One feature of fish and other aquatic species that makes them more relevant as targets of environmental studies and of regulation is that they may not only become contaminated by pesticides or other chemicals, but that they constitute and important part of the human diet. In this chapter, we provide an overview of the enzymes that are capable of metabolizing or otherwise assisting in the removal of xenobiotics from aquatic species. Many studies have been performed on the enzymes that are responsible for metabolizing xenobiotics. In addition to the use of conventional biochemical methods, such studies on enzymes are increasingly being conducted using immunochemical methods and amino acid or gene sequences analysis. Such studies have been performed in algae, in some aquatic macrophytes, and in bivalva, but less information is available for other aquatic species such as crustacea, annelids, aquatic insecta, and other species. Although their catabolizing activity is often lower than in mammals, oxidases, especially cytochrome P450 enzymes, play a central role in transforming pesticides in aquatic organisms. Primary metabolites, formed from such initial enzymatic action, are further conjugated with natural components such as carbohydrates, and this aids removal form the organisms. The pesticides that are susceptible to abiotic hydrolysis are generally also biotically degraded by various esterases to from hydrophilic conjugates. Reductive transformation is the main metabolic pathway for organochlorine pesticides, but less information on reductive enzymology processes is available. The

Management of autotrophic mass cultures of micro-algae

CSIR Research Space (South Africa)

Toerien, DF

1987-01-01

Full Text Available Interest in the mass cultivation of micro-algae as feed and foodstuff has existed since the turn of the century (Robinson and Toerien, 1962). Experiments using algae in photosynthetic research (Warburg, 1919) also led to an appreciation...

Improvement of aquaponic performance through micro- and macro-nutrient addition.

Science.gov (United States)

Ru, Dongyun; Liu, Jikai; Hu, Zhen; Zou, Yina; Jiang, Liping; Cheng, Xiaodian; Lv, Zhenting

2017-07-01

Aquaponics is one of the "zero waste" industry in the twenty-first century, and is considered to be one of the major trends for the future development of agriculture. However, the low nitrogen utilization efficiency (NUE) restricted its widely application. To date, many attempts have been conducted to improve its NUE. In the present study, effect of micro- and macro-nutrient addition on performance of tilapia-pak choi aquaponics was investigated. Results showed that the addition of micro- and macro-nutrients improved the growth of plant directly and facilitated fish physiology indirectly, which subsequently increased NUE of aquaponics from 40.42 to 50.64%. In addition, remarkable lower total phosphorus concentration was obtained in aquaponics with micro- and macro-nutrient addition, which was attributed to the formation of struvite. Most of the added micro-nutrients were enriched in plant root, while macro-nutrients mainly existed in water. Moreover, no enrichment of micro- and macro-nutrients in aquaponic products (i.e., fish and plant leaves) was observed, indicating that it had no influence on food safety. The findings here reported manifest that appropriate addition of micro- and macro-nutrients to aquaponics is necessary, and would improve its economic feasibility.

Marine Algae as Source of Novel Antileishmanial Drugs: A Review

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Lauve Rachel Tchokouaha Yamthe

2017-10-01

Full Text Available Leishmaniasis is a vector-borne neglected tropical disease caused by protozoan parasites of the Leishmania genus and transmitted by the female Phlebotomus and Lutzomyia sand flies. The currently prescribed therapies still rely on pentavalent antimonials, pentamidine, paromomycin, liposomal amphotericin B, and miltefosine. However, their low efficacy, long-course treatment regimen, high toxicity, adverse side effects, induction of parasite resistance and high cost require the need for better drugs given that antileishmanial vaccines may not be available in the near future. Although most drugs are still derived from terrestrial sources, the interest in marine organisms as a potential source of promising novel bioactive natural agents has increased in recent years. About 28,000 compounds of marine origin have been isolated with hundreds of new chemical entities. Recent trends in drug research from natural resources indicated the high interest of aquatic eukaryotic photosynthetic organisms, marine algae in the search for new chemical entities given their broad spectrum and high bioactivities including antileishmanial potential. This current review describes prepared extracts and compounds from marine macroalgae along with their antileishmanial activity and provides prospective insights for antileishmanial drug discovery.

Influence of Algae Age and Population on the Response to TiO₂ Nanoparticles.

Science.gov (United States)

Metzler, David M; Erdem, Ayca; Huang, Chin Pao

2018-03-25

This work shows the influence of algae age (at the time of the exposure) and the initial algae population on the response of green algae Raphidocelis subcapitata to titanium dioxide nanoparticles (TiO₂ NPs). The different algae age was obtained by changes in flow rate of continually stirred tank reactors prior to NP exposure. Increased algae age led to a decreased growth, variations in chlorophyll content, and an increased lipid peroxidation. Increased initial algae population (0.3-4.2 × 10⁶ cells/mL) at a constant NP concentration (100 mg/L) caused a decline in the growth of algae. With increased initial algae population, the lipid peroxidation and chlorophyll both initially decreased and then increased. Lipid peroxidation had 4× the amount of the control at high and low initial population but, at mid-ranged initial population, had approximately half the control value. Chlorophyll a results also showed a similar trend. These results indicate that the physiological state of the algae is important for the toxicological effect of TiO₂ NPs. The condition of algae and exposure regime must be considered in detail when assessing the toxicological response of NPs to algae.

Algae Bloom in a Lake

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David Sanabria

2008-01-01

Full Text Available The objective of this paper is to determine the likelihood of an algae bloom in a particular lake located in upstate New York. The growth of algae in this lake is caused by a high concentration of phosphorous that diffuses to the surface of the lake. Our calculations, based on Fick's Law, are used to create a mathematical model of the driving force of diffusion for phosphorous. Empirical observations are also used to predict whether the concentration of phosphorous will diffuse to the surface of this lake within a specified time and under specified conditions.

Combining of radionuclides with constituent materials of marine algae

International Nuclear Information System (INIS)

Nakamura, Ryoichi; Nakahara, Motokazu; Ishii, Toshiaki; Ueda, Taishi; Shimizu, Chiaki.

1979-01-01

The relations between the accumulation-elimination of radionuclides and the constituent materials of marine algae were studied to determine more precisely the mechanism of the radioactive contamination of marine organisms. This will increase the information about the behavior of radionuclides in marine organisms in relation to the environmental conditions (temperature, physico-chemical state of radioisotope, and so on) and the biological conditions (feeding habits, species, and so on). Eisenia contaminated by 137 Cs and 106 Ru- 106 Rh was fractionated by solvent extraction into 6 fractions. The largest portion of 137 Cs was in the boiling water fraction; 106 Ru- 106 Rh was most extracted by 24% KOH solution. Elution patterns by Sephadex G-100 gel-filtration of samples differed largely from each other, both among the 3 kinds of radionuclides and between the 2 species of the algae. Therefore, the accumulation of the radionuclides by the marine algae was proved to be not only due to a physical absorption to the surface of the algae but also to the biological combining of the radionuclides with the constituents of the algae. Furthermore, it was found that radionuclides which combine with a few constituents of alga are not eliminated equally. This is considered to be useful for the physiological analysis of elimination curves. (author)

Biodiesel Production From Algae to Overcome the Energy Crisis

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Suliman Khan

2017-10-01

Full Text Available The use of energy sources has reached at the level that whole world is relying on it. Being the major source of energy, fuels are considered the most important. The fear of diminishing the available sources thirst towards biofuel production has increased during last decades. Considering the food problems, algae gain the most attention to be used as biofuel producers. The use of crop and food-producing plants will never be a best fit into the priorities for biofuel production as they will disturb the food needs. Different types of algae having the different production abilities. Normally algae have 20%–80% oil contents that could be converted into different types of fuels such as kerosene oil and biodiesel. The diesel production from algae is economical and easy. Different species such as tribonema, ulothrix and euglena have good potential for biodiesel production. Gene technology can be used to enhance the production of oil and biodiesel contents and stability of algae. By increasing the genetic expressions, we can find the ways to achieve the required biofuel amounts easily and continuously to overcome the fuels deficiency. The present review article focusses on the role of algae as a possible substitute for fossil fuel as an ideal biofuel reactant.

Investigation about Role of Algae in Kazeroon Sasan Spring Odor

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A Hamzeian

2016-05-01

Full Text Available Introduction: As odor for potable water is unpleasant for costumers, it needs to do researches for finding the reasons of odorous water. Sasan spring that is located in, near kazeroon city, Fars, Iran, is potable water resource for Kazeroon and Booshehr city and many other villages. Water in Sasan spring has the odor problem. With regards to important   role of algae on ado r problems in this study the role of algae on   odor was investigated. Methods: After regular sampling, the TON (threshold odor number was indicated and algae species was distinguished and the number of total algae and any species  of algae was numbers by microscopic direct numbering method .as the algae mass  is related to nitrogen and phosphor concentration, results of concentration Of nitrogen and phosphor in this spring that was examined regularity by water company was investigated and compared to concentration of these component that are need for algae growing.   Results: results shows that TON was in range  of 4.477 to 6.2 that indicated  oderous limit . Regression and diagram between TON and number of total algae showed the linear relationship. The concentration of nitrogen and phosphor, showed adequate condition for algal grow. Result of determination of algae species showed high population of Oscilatoria and Microcystis species, which are known as essential case of mold odor in water resources. Investigation on geological maps in the region around the Sasan spring, show alluvium source and is effected by surface part of it’s around land. Conclusion: because of the algae was determined as the essential cause of odor   in the spring, and algal growth is related to nutrients, and because of the surface pollution can penetrate in the alluvium lands around the spring, and effect the water in spring, so nutrient control and management is the essential way for odor control in the spring.

Biological Macro and Micro Systems Co-existing in the “Fountain of the Two Dragons”, Palermo

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Enza Di Carlo

2017-06-01

Full Text Available Stone works of art located outdoors are exposed to natural deterioration, due to several physical, chemical and biological factors. Biological macro- and micro-systems (e.g. weeds, insects, algae, mosses, fungi and bacteria may induce the biodeterioration of stone materials. In February 2014, the state of conservation of the Fountain of the two Dragons in Palermo was examined, during which time biological colonization in some areas of the fountain and statues, was also detected. The monument represents an excellent substrate for the development and growth of microrganisms and organisms that need a continuous supply of water. Direct solar irradiance promotes the development of photoautotrophic organisms, bryophyte flora, in addition to several microbial genera, responsible for pigmentation, discoloring, efflorescence. After autotrophic colonization, some organisms find an ideal habitat also during wintertime, including two species of gastropods and two species of Hemiptera, omnivorous, a species of Collembola, mostly fungivorous. This interdisciplinary study has enabled the detection and identification of different biological communities, providing information for a subsequent project of preventive conservation of the fountain and its surroundings.

SOIL ALGAE OF BLADE OF COIL IN DONETSK REGION

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Maltseva I.A.

2011-12-01

Full Text Available On territory of Donbass for more than 200 years the underground coal mining has produced, accompanied by the formation of the mine dumps. Finding ways to reduce their negative impact on the environment should be based on their comprehensive study. The soil algae are active participants in the syngenetic processes in industrial dumps of different origin. The purpose of this paper is to identify the species composition and dominant algae groups in dump mine SH/U5 “Western” in the western part of Donetsk.The test blade is covered with vegetation to the middle from all sides, and on the north side of 20-25 m to the top. The vegetation cover of the lower and middle tiers of all the exposures range in 70-80%. Projective vegetation cover of upper tiers of the northern, north-eastern and north-western exposures are in the range of 20-40%, other – 5-10%. We revealed some 38 algae species as a result of our research in southern, northern, western, and eastern slopes of the blade “Western”. The highest species diversity has Chlorophyta - 14 species (36.8% of the total number of species, then Cyanophyta - 9 (23,7%, Bacillariophyta - 7 (18,4%, Xantophyta - 5 (13.2%, and Eustigmatophyta - 3 (7.9%. The dominants are represented by Hantzschia amphyoxys (Ehrenberg Grunow in Cleve et Grunow, Bracteacoccus aerius, Klebsormidium flaccidum (Kützing Silva et al., Phormidium autumnale, Pinnularia borealis Ehrenberg, Planothidium lanceolatum (Brebisson in Kützing Bukhtiyarova, Xanthonema exile (Klebs Silva.It should be noted that the species composition of algae groups in different slopes of the blade was significantly different. Jacquard coefficient was calculated for algae communities varied in the range of 15,4-39,1%. The smallest number of algae species was observed on the southern slope of the blade (14 species, maximum was registered in the areas of north and west slopes. Differences in the species composition of algae were also observed in three

Production and characterization of algae extract from Chlamydomonas reinhardtii

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Weston Kightlinger

2014-01-01

Conclusions: This study showed that algae extract derived from C. reinhardtii is similar, if not superior, to commercially available yeast extract in nutrient content and effects on the growth and metabolism of E. coli and S. cerevisiae. Bacto™ yeast extract is valued at USD $0.15–0.35 per gram, if algae extract was sold at similar prices, it would serve as a high-value co-product in algae-based fuel processes.

Multi-scale-nonlinear interactions among macro-MHD mode, micro-turbulence, and zonal flow

International Nuclear Information System (INIS)

Ishizawa, Akihiro; Nakajima, Noriyoshi

2007-01-01

This is the first numerical simulation demonstrating that macro-magnetohydrodynamic (macro-MHD) mode is exited as a result of multi-scale interaction in a quasi-steady equilibrium formed by a balance between zonal flow and micro-turbulence via reduced-two-fluid simulation. Only after obtaining the equilibrium which includes zonal flow and the turbulence caused by kinetic ballooning mode is this simulation of macro-MHD mode, double tearing mode, accomplished. In the quasi-steady equilibrium a macro-fluctuation which has the same helicity as that of double tearing mode is a part of the turbulence until it grows as a macro-MHD mode finally. When the macro-MHD grows it effectively utilize free energy of equilibrium current density gradient because of positive feedback loop between suppression of zonal flow and growth of the macro-fluctuation causing magnetic reconnection. Thus once the macro-MHD grows from the quasi-equilibrium, it does not go back. This simulation is more comparable with experimental observation of growing macro-fluctuation than traditional MHD simulation of linear instabilities in a static equilibrium. (author)

Macro-Micro Simulation for Polymer Crystallization in Couette Flow

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Chunlei Ruan

2017-12-01

Full Text Available Polymer crystallization in manufacturing is a process where quiescent crystallization and flow-induced crystallization coexists, and heat/mass transfer on a macroscopic level interacts with crystal morphology evolution on a microscopic level. Previous numerical studies on polymer crystallization are mostly concentrated at a single scale; they only calculate macroscale parameters, e.g., temperature and relative crystallinity, or they only predict microstructure details, e.g., crystal morphology and mean size of crystals. The multi-scale numerical works that overcome these disadvantages are unfortunately based on quiescent crystallization, in which flow effects are neglected. The objective of this work is to build up a macro-micro model and a macro-micro algorithm to consider both the thermal and flow effects on the crystallization. Our macro-micro model couples two parts: mass and heat transfer of polymeric flow at the macroscopic level, and nucleation and growth of spherulites and shish-kebabs at the microscopic level. Our macro-micro algorithm is a hybrid finite volume/Monte Carlo method, in which the finite volume method is used at the macroscopic level to calculate the flow and temperature fields, while the Monte Carlo method is used at the microscopic level to capture the development of spherulites and shish-kebabs. The macro-micro model and the macro-micro algorithm are applied to simulate polymer crystallization in Couette flow. The effects of shear rate, shear time, and wall temperature on the crystal morphology and crystallization kinetics are also discussed.

Two-step evolution of endosymbiosis between hydra and algae.

Science.gov (United States)

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. Copyright © 2016 Elsevier Inc. All rights reserved.

Two-Step Evolution of Endosymbiosis between Hydra and Algae

KAUST Repository

Ishikawa, Masakazu

2016-07-09

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.

Detection of viability of micro-algae cells by optofluidic hologram pattern.

Science.gov (United States)

Wang, Junsheng; Yu, Xiaomei; Wang, Yanjuan; Pan, Xinxiang; Li, Dongqing

2018-03-01

A rapid detection of micro-algae activity is critical for analysis of ship ballast water. A new method for detecting micro-algae activity based on lens-free optofluidic holographic imaging is presented in this paper. A compact lens-free optofluidic holographic imaging device was developed. This device is mainly composed of a light source, a small through-hole, a light propagation module, a microfluidic chip, and an image acquisition and processing module. The excited light from the light source passes through a small hole to reach the surface of the micro-algae cells in the microfluidic chip, and a holographic image is formed by the diffraction light of surface of micro-algae cells. The relation between the characteristics in the hologram pattern and the activity of micro-algae cells was investigated by using this device. The characteristics of the hologram pattern were extracted to represent the activity of micro-algae cells. To demonstrate the accuracy of the presented method and device, four species of micro-algae cells were employed as the test samples and the comparison experiments between the alive and dead cells of four species of micro-algae were conducted. The results show that the developed method and device can determine live/dead microalgae cells accurately.

Using the marine unicellular algae in biological monitoring

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Kapkov V. I.

2017-06-01

Full Text Available The possibility of using marine unicellular algae from natural plankton community in biomonitoring of pollution by heavy metals has been investigated. Algae of different taxa from the Mediterranean Sea have been allocated to culture. In the laboratory the culture conditions – i. e. growth medium, temperature, photoperiod, level of artificial light and initial density – have been selected for every species. The impact of heavy metals (Hg, Cd, Cu, Pb in the form of chloride salts on the growth of axenic algae culture has been studied in the modelling experiments. The unicellular marine algae have a very short life cycle, therefore it is possible to use them in the experiments of studying the effect of anthropogenic factors at cellular and population levels on the test-object. With biomonitoring pollution of marine environment by heavy metals and others dangerous toxicants, the major indicators of algae community condition are the cellular cycle and the condition of the photosynthetic apparatus of the cell. The subsequent lysis of cells under the influence of heavy metals leads to the excretion of secondary metabolites which can essentially affect the metal toxicity. The established scales of threshold and lethal concentration of heavy metals for algae of different taxon make it possible to use the ratio of sensitive and resistant species to heavy metals as biological markers when forecasting ecological consequences of pollution of the marine environment by heavy metals. Distinctions in the resistance of different taxon to heavy metals can result in implementing the strategy of selection of test-objects depending on the purposes of the research.

The integrated evaluation of the macro environment of companies providing transport services

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A. Žvirblis

2008-09-01

Full Text Available The article presents the main principles of the integrated evaluation of macro environment components and factors influencing the performance of transport companies as well as providing the validated quantitative evaluation models and results obtained in evaluating the macro environment of Lithuanian companies providing transport services. Since quantitative evaluation is growing in importance, the process of developing the principles and methods of business macro environment quantitative evaluation is becoming relevant from both theoretical and practical perspectives. The created methodology is based on the concept of macro environment as an integrated whole of components, formalization and the principle of three-stage quantitative evaluation. The methodology suggested involves the quantitative evaluation of primary factors and macro environment components as an integral dimension (expressed in points. On the basis of this principle, an integrated macro environment evaluation parameter is established as its level index. The methodology integrates the identification of significant factors, building scenarios, a primary analysis of factors, expert evaluation, the quantitative evaluation of macro environment components and their whole. The application of the multi-criteria Simple Additive Weighting (SAW method is validated. The integrated evaluation of the macro environment of Lithuanian freight transportation companies was conducted. As a result, the level indices of all components as well as the level index of macro environment considered as a whole of components were identified. The latter reflects the extent of deviation from an average level of a favourable macro environment. This is important for developing strategic marketing decisions and expanding a strategic area.

Toxicity of fluoride to aquatic species and evaluation of toxicity modifying factors.

Science.gov (United States)

Pearcy, Krysta; Elphick, James; Burnett-Seidel, Charlene

2015-07-01

The present study was performed to investigate the toxicity of fluoride to a variety of freshwater aquatic organisms and to establish whether water quality variables contribute substantively to modifying its toxicity. Water hardness, chloride, and alkalinity were tested as possible toxicity modifying factors for fluoride using acute toxicity tests with Hyalella azteca and Oncorhynchus mykiss. Chloride appeared to be the major toxicity modifying factor for fluoride in these acute toxicity tests. The chronic toxicity of fluoride was evaluated with a variety of species, including 3 fish (Pimephales promelas, O. mykiss, and Salvelinus namaycush), 3 invertebrates (Ceriodaphnia dubia, H. azteca, and Chironomus dilutus), 1 plant (Lemna minor), and 1 alga (Pseudokirchneriella subcapitata). Hyalella azteca was the most sensitive species overall, and O. mykiss was the most sensitive species of fish. The role of chloride as a toxicity modifying factor was inconsistent between species in the chronic toxicity tests. © 2015 SETAC.

Biological Nutrient Removal in Compact Biofilm Systems

OpenAIRE

Bassin, J.P.

2012-01-01

The removal of nutrients such as nitrogen and phosphorus from both domestic and industrial wastewaters is imperative since they potentially harm the environment. One of the main consequences of excessive availability of nitrogen and phosphorus in aquatic ecosystems (freshwater, marine and estuarine) is the overgrowth of algae and other aquatic plants, a phenomenon designated as eutrophication. Algae and aquatic plants induce depletion of oxygen in water basins, resulting in massive death of e...

Using AquaticHealth.net to Detect Emerging Trends in Aquatic Animal Health

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Geoff Grossel

2013-05-01

Full Text Available AquaticHealth.net is an open-source aquatic biosecurity intelligence application. By combining automated data collection and human analysis, AquaticHealth.net provides fast and accurate disease outbreak detection and forecasts, accompanied with nuanced explanations. The system has been online and open to the public since 1 January 2010, it has over 200 registered expert users around the world, and it typically publishes about seven daily reports and two weekly disease alerts. We document the major trends in aquatic animal health that the system has detected over these two years, and conclude with some forecasts for the future.

The Generalist Model: Where do the Micro and Macro Converge?

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Shari E. Miller

2008-12-01

Full Text Available Although macro issues are integral to social work, students continue to struggle with the acquisition of knowledge and skills pertaining to larger systems. Educators have developed innovative methods to integrate learning across systems of various sizes however it appears an imbalance persists. This challenge is supported by baccalaureate student responses to a social work program evaluation. Four years of data from 295 undergraduate students revealed that they felt less prepared to practice with larger, macro systems. Changes in curriculum to reflect collaboration and holism, and more research are needed to adequately provide macro learning and macro practice opportunities within the generalist model and in the context of the current socio-economic-political environment.

Genomics of Volvocine Algae

Science.gov (United States)

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

Algae as a Biofuel: Renewable Source for Liquid Fuel

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Vijay Kant Pandey

2016-09-01

Full Text Available Biofuels produced by algae may provide a feasible alternative to fossil fuels like petroleum sourced fuels. However, looking to limited fossil fuel associated with problems, intensive efforts have been given to search for alternative biofuels like biodiesel. Algae are ubiquitous on earth, have potential to produce biofuel. However, technology of biofuel from algae facing a number of hurdles before it can compete in the fuel market and be broadly organized. Different challenges include strain identification and improvement of algal biomass, both in terms of biofuel productivity and the production of other products to improve the economics of the entire system. Algal biofuels could be made more cost effective by extracting other valuable products from algae and algal strains. Algal oil can be prepared by culture of algae on municipal and industrial wastewaters. Photobioreactors methods provide a controlled environment that can be tailored to the specific demands of high production of algae to attain a consistently good yield of biofuel. The algal biomass has been reported to yield high oil contents and have good amount of the biodiesel production capacity. In this article, it has been attempted to review to elucidate the approaches for making algal biodiesel economically competitive with respect to petrodiesel. Consequently, R & D work has been carried out for the growth, harvesting, oil extraction and conversion to biodiesel from algal sources.

Molecular ecology of aquatic microbes

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-12-31

Abstracts of reports are presented from a meeting on Molecular Ecology of Aquatic Microbes. Topics included: opportunities offered to aquatic ecology by molecular biology; the role of aquatic microbes in biogeochemical cycles; characterization of the microbial community; the effect of the environment on aquatic microbes; and the targeting of specific biological processes.

Macro-elementwise preconditioning methods

Czech Academy of Sciences Publication Activity Database

Axelsson, Owe

2012-01-01

Roč. 82, č. 10 (2012), s. 1952-1963 ISSN 0378-4754 Institutional research plan: CEZ:AV0Z30860518 Keywords : heterogeniety * elementwise preconditioning * block matrix partitioning * macro-elements Subject RIV: BA - General Mathematics Impact factor: 0.836, year: 2012 http://www.sciencedirect.com/science/journal/03784754

Co-occurrence of the cyanotoxins BMAA, DABA and anatoxin-a in Nebraska reservoirs, fish, and aquatic plants.

Science.gov (United States)

Al-Sammak, Maitham Ahmed; Hoagland, Kyle D; Cassada, David; Snow, Daniel D

2014-01-28

Several groups of microorganisms are capable of producing toxins in aquatic environments. Cyanobacteria are prevalent blue green algae in freshwater systems, and many species produce cyanotoxins which include a variety of chemical irritants, hepatotoxins and neurotoxins. Production and occurrence of potent neurotoxic cyanotoxins β-N-methylamino-L-alanine (BMAA), 2,4-diaminobutyric acid dihydrochloride (DABA), and anatoxin-a are especially critical with environmental implications to public and animal health. Biomagnification, though not well understood in aquatic systems, is potentially relevant to both human and animal health effects. Because little is known regarding their presence in fresh water, we investigated the occurrence and potential for bioaccumulation of cyanotoxins in several Nebraska reservoirs. Collection and analysis of 387 environmental and biological samples (water, fish, and aquatic plant) provided a snapshot of their occurrence. A sensitive detection method was developed using solid phase extraction (SPE) in combination with high pressure liquid chromatography-fluorescence detection (HPLC/FD) with confirmation by liquid chromatography-tandem mass spectrometry (LC/MS/MS). HPLC/FD detection limits ranged from 5 to 7 µg/L and LC/MS/MS detection limits were <0.5 µg/L, while detection limits for biological samples were in the range of 0.8-3.2 ng/g depending on the matrix. Based on these methods, measurable levels of these neurotoxic compounds were detected in approximately 25% of the samples, with detections of BMAA in about 18.1%, DABA in 17.1%, and anatoxin-a in 11.9%.

KAROTENOID PADA ALGAE: KAJIAN TENTANG BIOSINTESIS, DISTRIBUSI SERTA FUNGSI KAROTENOID

OpenAIRE

Merdekawati, Windu; Karwur, Ferry F.; Susanto, A. B.

2017-01-01

ABSTRAK   Karotenoid terdistribusi pada archaea, bakteri, jamur, tumbuhan, hewan serta algae. Karotenoid dihasilkan dari komponen isopentenyl pyrophosphate (IPP) yang mengalami proses secara bertahap untuk membentuk beragam jenis karotenoid. Terdapat dua kelompok karotenoid yaitu karoten dan xantofil dengan berbagai jenis turunannya. Struktur kimia pada karotenoid algae yaitu allene, acetylene serta acetylated carotenoids. Algae mempunyai karotenoid spesifik yang menarik untuk dipe...

[Characteristics of heavy metals enrichment in algae ano its application prospects].

Science.gov (United States)

Lu, Kaixing; Tang, Jian-jun; Jiang, De'an

2006-01-01

Using algae to bio-remedy heavy metals-contaminated waters has become an available and practical approach for environmental restoration. Because of its special cell wall structure, high capacity of heavy metal-enrichment, and easy to desorption, algae has been considered as an ideal biological adsorbent. This paper briefly introduced the structural and metabolic characteristics adapted for heavy metals enrichment of algae, including functional groups on cell wall, extracellular products, and intracellular heavy metals-chelating proteins, discussed the enrichment capability of living, dead and immobilized algae as well as the simple and convenient ways for desorption, and analyzed the advantages and disadvantages of using algae for bioremediation of polluted water, and its application prospects.

New methodologies for the integration of power plants with algae ponds

NARCIS (Netherlands)

Schipper, K.; Gijp, S. van der; Stel, R.W van der; Goetheer, E.L.V.

2013-01-01

It is generally recognized that algae could be an interesting option for reducing CO2 emissions. Based on light and CO2, algae can be used for the production various economically interesting products. Current algae cultivation techniques, however, still present a number of limitations. Efficient

Assessment of in vitro antitumoral and antimicrobial activities of ...

African Journals Online (AJOL)

ONOS

2010-07-05

Jul 5, 2010 ... cell line, and it showed less than 10% cell viability after treatment. Antimicrobial ... marine macro algae have also been studied extensively. Antimicrobial ... Algae samples were washed twice with distilled water and air-dried.

Is there a risk for the aquatic environment due to the existence of emerging organic contaminants in treated domestic wastewater? Greece as a case-study.

Science.gov (United States)

Thomaidi, Vasiliki S; Stasinakis, Athanasios S; Borova, Viola L; Thomaidis, Nikolaos S

2015-01-01

The ecological threat associated with emerging pollutants detected in wastewater was estimated in country level. Treated wastewater was analyzed for pharmaceuticals and illicit drugs; whereas the concentrations of all emerging contaminants determined in Greek Sewage Treatment Plants were recorded through literature review. Toxicity data was collected after literature review or using ECOSAR and risk quotients (RQs) were calculated for treated wastewater and 25 Greek rivers, for 3 different aquatic organisms (fish, daphnia magna, algae). According to the results, monitoring data was available for 207 micropollutants belonging to 8 different classes. RQ>1 was calculated for 30 compounds in secondary treated wastewater. Triclosan presented RQ>1 (in algae) for all studied rivers; decamethylcyclopentasilane (in daphnia magna), caffeine (in algae) and nonylphenol (in fish) presented RQ>1 in rivers with dilution factors (DF) equal or lower to 1910, 913 and 824, respectively. The class of emerging contaminants that present the greatest threat due to single or mixture toxicity was endocrine disrupters. The mixture of microcontaminants seems to pose significant ecological risk, even in rivers with DF equal to 2388. Future national monitoring programs should include specific microcontaminants that seem to possess environment risk to surface water. Copyright © 2014 Elsevier B.V. All rights reserved.

Freshwater algae competition and correlation between their growth and microcystin production.

Science.gov (United States)

Álvarez, Xana; Valero, Enrique; Cancela, Ángeles; Sánchez, Ángel

2016-11-01

There are some different freshwater algae in Eutrophic reservoirs which bloom with specific environmental conditions, and some of them are cyanobacteria. In this investigation, we have cultivated microalgae present in natural water samples from a eutrophic reservoir. Variations in temperature and light were evaluated, as well as the competition among different green algae and cyanobacteria. There were three different freshwater algae growing together, Scenedesmus sp., Kirchneriella sp. and Microcystis aeruginosa, this cyanobacterium was the algae that reached the highest development and growth during the culture. While the algae grew, the concentration of toxin (microcystin-LR) increased until it reached the highest levels at 570 μg g -1 . Blooms occurred at temperatures of 28 ± 1.5 °C and light cycles of longer hours of light than dark. This took place during the summer months, from June to September (in the study area). At temperatures below 18 °C, algae did not grow. Blooms were reproduced to a laboratory scale in different conditions in order to understand the development of freshwater algae, as well as to help decision-making about water supply from that reservoir.

Inorganic carbon addition stimulates snow algae primary productivity

Science.gov (United States)

Hamilton, T. L.; Havig, J. R.

2017-12-01

Earth has experienced glacial/interglacial oscillations throughout its history. Today over 15 million square kilometers (5.8 million square miles) of Earth's land surface is covered in ice including glaciers, ice caps, and the ice sheets of Greenland and Antarctica, most of which are retreating as a consequence of increased atmospheric CO2. Glaciers are teeming with life and supraglacial snow and ice surfaces are often red due to blooms of photoautotrophic algae. Recent evidence suggests the red pigmentation, secondary carotenoids produced in part to thrive under high irradiation, lowers albedo and accelerates melt. However, there are relatively few studies that report the productivity of snow algae communities and the parameters that constrain their growth on snow and ice surfaces. Here, we demonstrate that snow algae primary productivity can be stimulated by the addition of inorganic carbon. We found an increase in light-dependent carbon assimilation in snow algae microcosms amended with increasing amounts of inorganic carbon. Our snow algae communities were dominated by typical cosmopolitan snow algae species recovered from Alpine and Arctic environments. The climate feedbacks necessary to enter and exit glacial/interglacial oscillations are poorly understood. Evidence and models agree that global Snowball events are accompanied by changes in atmospheric CO2 with increasing CO2 necessary for entering periods of interglacial time. Our results demonstrate a positive feedback between increased CO2 and snow algal productivity and presumably growth. With the recent call for bio-albedo effects to be considered in climate models, our results underscore the need for robust climate models to include feedbacks between supraglacial primary productivity, albedo, and atmospheric CO2.

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

Science.gov (United States)

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

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

Science.gov (United States)

Cui, Hongli; Yu, Xiaona; Wang, Yan; Cui, Yulin; Li, Xueqin; Liu, Zhaopu; Qin, Song

2013-07-08

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. 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. 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 green algae and higher plants

Ordered macro-microporous metal-organic framework single crystals

KAUST Repository

Shen, Kui

2018-01-16

We constructed highly oriented and ordered macropores within metal-organic framework (MOF) single crystals, opening up the area of three-dimensional-ordered macro-microporous materials (that is, materials containing both macro- and micropores) in single-crystalline form. Our methodology relies on the strong shaping effects of a polystyrene nanosphere monolith template and a double-solvent-induced heterogeneous nucleation approach. This process synergistically enabled the in situ growth of MOFs within ordered voids, rendering a single crystal with oriented and ordered macro-microporous structure. The improved mass diffusion properties of such hierarchical frameworks, together with their robust single-crystalline nature, endow them with superior catalytic activity and recyclability for bulky-molecule reactions, as compared with conventional, polycrystalline hollow, and disordered macroporous ZIF-8.

Ordered macro-microporous metal-organic framework single crystals

Science.gov (United States)

Shen, Kui; Zhang, Lei; Chen, Xiaodong; Liu, Lingmei; Zhang, Daliang; Han, Yu; Chen, Junying; Long, Jilan; Luque, Rafael; Li, Yingwei; Chen, Banglin

2018-01-01

We constructed highly oriented and ordered macropores within metal-organic framework (MOF) single crystals, opening up the area of three-dimensional–ordered macro-microporous materials (that is, materials containing both macro- and micropores) in single-crystalline form. Our methodology relies on the strong shaping effects of a polystyrene nanosphere monolith template and a double-solvent–induced heterogeneous nucleation approach. This process synergistically enabled the in situ growth of MOFs within ordered voids, rendering a single crystal with oriented and ordered macro-microporous structure. The improved mass diffusion properties of such hierarchical frameworks, together with their robust single-crystalline nature, endow them with superior catalytic activity and recyclability for bulky-molecule reactions, as compared with conventional, polycrystalline hollow, and disordered macroporous ZIF-8.

Ordered macro-microporous metal-organic framework single crystals

KAUST Repository

Shen, Kui; Zhang, Lei; Chen, Xiaodong; Liu, Lingmei; Zhang, Daliang; Han, Yu; Chen, Junying; Long, Jilan; Luque, Rafael; Li, Yingwei; Chen, Banglin

2018-01-01

We constructed highly oriented and ordered macropores within metal-organic framework (MOF) single crystals, opening up the area of three-dimensional-ordered macro-microporous materials (that is, materials containing both macro- and micropores) in single-crystalline form. Our methodology relies on the strong shaping effects of a polystyrene nanosphere monolith template and a double-solvent-induced heterogeneous nucleation approach. This process synergistically enabled the in situ growth of MOFs within ordered voids, rendering a single crystal with oriented and ordered macro-microporous structure. The improved mass diffusion properties of such hierarchical frameworks, together with their robust single-crystalline nature, endow them with superior catalytic activity and recyclability for bulky-molecule reactions, as compared with conventional, polycrystalline hollow, and disordered macroporous ZIF-8.

Act together – implications of symbioses in aquatic ciliates

Directory of Open Access Journals (Sweden)

Claudia eDziallas

2012-08-01

Full Text Available Mutual interactions in form of symbioses can increase the fitness of organisms and provide them with the capacity to occupy new ecological niches. The formation of obligate symbioses allows for rapid evolution of new life forms including multitrophic consortia. Microbes are important components of many known endosymbioses and their short generation times and strong potential for genetic exchange may be important drivers of speciation. Hosts provide endo- and ectosymbionts with stable, nutrient-rich environments and protection from environmental stresses. This is of particular importance in aquatic ecosystems, which are often highly variable, harsh and nutrient-deficient habitats. Thus it is not surprising that symbioses are widespread in both marine and freshwater environments. Symbioses in aquatic ciliates are good model systems for exploring symbiont-host interactions. Many ciliate species are globally distributed and have been intensively studied in the context of plastid evolution. Their relatively large cell size offers an ideal habitat for numerous microorganisms with different functional traits including commensalism and parasitism. Phagocytosis facilitates the formation of symbiotic relationships, particularly since some ingested microorganisms can escape the digestion. For example, photoautotrophic algae and methanogens represent endosymbionts that greatly extend the biogeochemical functions of their hosts. Consequently, symbiotic relationships between protists and prokaryotes are widespread and often result in new ecological functions of symbiotic communities. This enables ciliates to thrive under a wide range of environmental conditions including ultraoligotrophic or anoxic habitats. We summarize the current understanding of this exciting research topic to identify the many areas in which knowledge is lacking and to stimulate future research by providing an overview on new methodologies and by formulating a number of emerging

Recent Advances in Marine Algae Polysaccharides: Isolation, Structure, and Activities.

Science.gov (United States)

Xu, Shu-Ying; Huang, Xuesong; Cheong, Kit-Leong

2017-12-13

Marine algae have attracted a great deal of interest as excellent sources of nutrients. Polysaccharides are the main components in marine algae, hence a great deal of attention has been directed at isolation and characterization of marine algae polysaccharides because of their numerous health benefits. In this review, extraction and purification approaches and chemico-physical properties of marine algae polysaccharides (MAPs) are summarized. The biological activities, which include immunomodulatory, antitumor, antiviral, antioxidant, and hypolipidemic, are also discussed. Additionally, structure-function relationships are analyzed and summarized. MAPs' biological activities are closely correlated with their monosaccharide composition, molecular weights, linkage types, and chain conformation. In order to promote further exploitation and utilization of polysaccharides from marine algae for functional food and pharmaceutical areas, high efficiency, and low-cost polysaccharide extraction and purification methods, quality control, structure-function activity relationships, and specific mechanisms of MAPs activation need to be extensively investigated.

Benthic algae stimulate leaf litter decomposition in detritus-based headwater streams: a case of aquatic priming effect?

Science.gov (United States)

Danger, Michael; Cornut, Julien; Chauvet, Eric; Chavez, Paola; Elger, Arnaud; Lecerf, Antoine

2013-07-01

In detritus-based ecosystems, autochthonous primary production contributes very little to the detritus pool. Yet primary producers may still influence the functioning of these ecosystems through complex interactions with decomposers and detritivores. Recent studies have suggested that, in aquatic systems, small amounts of labile carbon (C) (e.g., producer exudates), could increase the mineralization of more recalcitrant organic-matter pools (e.g., leaf litter). This process, called priming effect, should be exacerbated under low-nutrient conditions and may alter the nature of interactions among microbial groups, from competition under low-nutrient conditions to indirect mutualism under high-nutrient conditions. Theoretical models further predict that primary producers may be competitively excluded when allochthonous C sources enter an ecosystem. In this study, the effects of a benthic diatom on aquatic hyphomycetes, bacteria, and leaf litter decomposition were investigated under two nutrient levels in a factorial microcosm experiment simulating detritus-based, headwater stream ecosystems. Contrary to theoretical expectations, diatoms and decomposers were able to coexist under both nutrient conditions. Under low-nutrient conditions, diatoms increased leaf litter decomposition rate by 20% compared to treatments where they were absent. No effect was observed under high-nutrient conditions. The increase in leaf litter mineralization rate induced a positive feedback on diatom densities. We attribute these results to the priming effect of labile C exudates from primary producers. The presence of diatoms in combination with fungal decomposers also promoted decomposer diversity and, under low-nutrient conditions, led to a significant decrease in leaf litter C:P ratio that could improve secondary production. Results from our microcosm experiment suggest new mechanisms by which primary producers may influence organic matter dynamics even in ecosystems where autochthonous

Association of thraustochytrids and fungi with living marine algae

Digital Repository Service at National Institute of Oceanography (India)

Raghukumar, C.; Nagarkar, S.; Raghukumar, S.

only in C. clavulatum, Sargassum cinereum and Padina tetrastromatica whilst mycelial fungi occurred in all. Growth experiments in the laboratory indicated that the growth of thraustochytrids was inhibited on live algae, whereas killed algae supported...

Quorum Sensing Inhibition by Asparagopsis taxiformis, a Marine Macro Alga: Separation of the Compound that Interrupts Bacterial Communication

Directory of Open Access Journals (Sweden)

Anton Hartmann

2013-01-01

Full Text Available The majority of the marine algal species, though completing their life cycle in seawater, are rarely susceptible to fouling, making them an important source of quorum sensing (QS inhibitory substances. The separation and characterization of QS inhibitors are crucial for any potential application. Thirty marine macroalgae were tested for QS inhibition activity by using Chromobacterium violaceum CV026 as the reporter strain, and among them, Asparagopsis taxiformis showed antibacterial, as well as antiquorum, sensing activities. Cinnamaldehyde (75 mM and methanol were used as positive and negative controls, respectively. The antiquorum sensing activity of A. taxiformis was further confirmed using the sensor strain, Serratia liquefaciens MG44, having green fluorescent protein (gfp. Methanolic extract of the alga was fractionated by solid phase extraction (SPE, and each fraction was tested for QS inhibition. Two types of activities were observed—zone of clearance (antibacterial activity and zone of inhibition with or without finger-like projections (QS inhibition. Out of five SPE cartridges, Bond Elut PH showed clear separation of these two fractions. The Ion Cyclotron Resonance Fourier Transformation Mass Spectrometer (ICR-FT/MS analysis of the fractions further supported the bioassay results. The presence of strong QS inhibitory compound in A. taxiformis indicates its potential use in antifouling preparations.

Method and apparatus for iterative lysis and extraction of algae

Science.gov (United States)

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.

Macro-Micro Interlocked Simulator

International Nuclear Information System (INIS)

Sato, Tetsuya

2005-01-01

Simulation Science is now standing on a turning point. After the appearance of the Earth Simulator, HEC is struggling with several severe difficulties due to the physical limit of LSI technologies and the so-called latency problem. In this paper I would like to propose one clever way to overcome these difficulties from the simulation algorithm viewpoint. Nature and artificial products are usually organized with several nearly autonomously working internal systems (organizations, or layers). The Earth Simulator has gifted us with a really useful scientific tool that can deal with the entire evolution of one internal system with a sufficient soundness. In order to make a leap jump of Simulation Science, therefore, it is desired to design an innovative simulator that enables us to deal with simultaneously and as consistently as possible a real system that evolves cooperatively with several internal autonomous systems. Three years experience of the Earth Simulator Project has stimulated to come up with one innovative simulation algorithm to get rid of the technological barrier standing in front of us, which I would like to call 'Macro-Micro Interlocked Algorithm', or 'Macro-Micro Multiplying Algorithm', and present a couple of such examples to validate the proposed algorithm. The first example is an aurora-arc formation as a result of the mutual interaction between the macroscopic magnetosphere-ionosphere system and the microscopic field-aligned electron and ion system. The second example is the local heavy rain fall resulting from the interaction between the global climate evolution and the microscopic raindrop growth process. Based on this innovative feasible algorithm, I came up with a Macro-Micro Multiplying Simulator

Healthy public policy in poor countries: tackling macro-economic policies.

Science.gov (United States)

Mohindra, K S

2007-06-01

Large segments of the population in poor countries continue to suffer from a high level of unmet health needs, requiring macro-level, broad-based interventions. Healthy public policy, a key health promotion strategy, aims to put health on the agenda of policy makers across sectors and levels of government. Macro-economic policy in developing countries has thus far not adequately captured the attention of health promotion researchers. This paper argues that healthy public policy should not only be an objective in rich countries, but also in poor countries. This paper takes up this issue by reviewing the main macro-economic aid programs offered by international financial institutions as a response to economic crises and unmanageable debt burdens. Although health promotion researchers were largely absent during a key debate on structural adjustment programs and health during the 1980s and 1990s, the international macro-economic policy tool currently in play offers a new opportunity to participate in assessing these policies, ensuring new forms of macro-economic policy interventions do not simply reproduce patterns of (neoliberal) economics-dominated development policy.

Biofuels from algae for sustainable development

International Nuclear Information System (INIS)

Demirbas, M. Fatih

2011-01-01

Microalgae are photosynthetic microorganisms that can produce lipids, proteins and carbohydrates in large amounts over short periods of time. These products can be processed into both biofuels and useful chemicals. Two algae samples (Cladophora fracta and Chlorella protothecoid) were studied for biofuel production. Microalgae appear to be the only source of renewable biodiesel that is capable of meeting the global demand for transport fuels. Microalgae can be converted to biodiesel, bioethanol, bio-oil, biohydrogen and biomethane via thermochemical and biochemical methods. Industrial reactors for algal culture are open ponds, photobioreactors and closed systems. Algae can be grown almost anywhere, even on sewage or salt water, and does not require fertile land or food crops, and processing requires less energy than the algae provides. Microalgae have much faster growth-rates than terrestrial crops. the per unit area yield of oil from algae is estimated to be from 20,000 to 80,000 liters per acre, per year; this is 7-31 times greater than the next best crop, palm oil. Algal oil can be used to make biodiesel for cars, trucks, and airplanes. The lipid and fatty acid contents of microalgae vary in accordance with culture conditions. The effect of temperature on the yield of hydrogen from two algae (C. fracta and C. protothecoid) by pyrolysis and steam gasification were investigated in this study. In each run, the main components of the gas phase were CO 2 , CO, H 2 , and CH 4 .The yields of hydrogen by pyrolysis and steam gasification processes of the samples increased with temperature. The yields of gaseous products from the samples of C. fracta and C. protothecoides increased from 8.2% to 39.2% and 9.5% to 40.6% by volume, respectively, while the final pyrolysis temperature was increased from 575 to 925 K. The percent of hydrogen in gaseous products from the samples of C. fracta and C. protothecoides increased from 25.8% to 44.4% and 27.6% to 48.7% by volume

Bio sorption of copper ions with biomass of algae and dehydrated waste of olives; Biosorcion de iones cobre con biomasa de algas y orujos deshidratados

Energy Technology Data Exchange (ETDEWEB)

Tapia, P.; Santander, M.; Pavez, O.; Valderrama, L.; Guzman, D.; Romero, L.

2011-07-01

They were carried out experiments of biosorption batch and in continuous to remove copper from aqueous solutions using as adsorbents green algae and olive residues under virgins conditions and chemically activated. The results of batch bio sorption indicate that the algae present mayor elimination capacities than the waste of olives, with uptakes of copper of the order of 96 % using activated algae with dissolution of Na{sub 2}SO{sub 4} under the optimum conditions. The results of the columns tests show that the virgin algae permits the removal of more copper ions than the activate algae, with removal efficiency of 98 % during the firth 20 min, a breakthrough time of 240 min and a saturation at time of 600 min. In the second cycle the regenerated biomass showed a best performance indicating that they can be used for another bio sorption cycle. (Author) 42 refs.

A review of the taxonomical and ecological studies on Netherlands’ Algae

NARCIS (Netherlands)

Koster, Joséphine Th.

1939-01-01

The earliest account of the Netherlands’ Algae appeared in 1781 in D. de Gorter, Flora VII Prov. Belgii foederati indigen. Here, however, in the Algae lichens and liverworts have been incorporated. The true Algae, of which 35 are enumerated, are principally marine, though also aërophytical and

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

Science.gov (United States)

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. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Washington State University Algae Biofuels Research

Energy Technology Data Exchange (ETDEWEB)

chen, Shulin [Washington State Univ., Pullman, WA (United States). Dept. of Biological Systems Engineering; McCormick, Margaret [Targeted Growth, Inc., Seattle, WA (United States); Sutterlin, Rusty [Inventure Renewables, Inc., Gig Harbor, WA (United States)

2012-12-29

The goal of this project was to advance algal technologies for the production of biofuels and biochemicals by establishing the Washington State Algae Alliance, a collaboration partnership among two private companies (Targeted Growth, Inc. (TGI), Inventure Chemicals (Inventure) Inc (now Inventure Renewables Inc) and Washington State University (WSU). This project included three major components. The first one was strain development at TGI by genetically engineering cyanobacteria to yield high levels of lipid and other specialty chemicals. The second component was developing an algal culture system at WSU to produce algal biomass as biofuel feedstock year-round in the northern states of the United States. This system included two cultivation modes, the first one was a phototrophic process and the second a heterotrophic process. The phototrophic process would be used for algae production in open ponds during warm seasons; the heterotrophic process would be used in cold seasons so that year-round production of algal lipid would be possible. In warm seasons the heterotrophic process would also produce algal seeds to be used in the phototrophic culture process. Selected strains of green algae and cyanobacteria developed by TGI were tested in the system. The third component was downstream algal biomass processing by Inventure that included efficiently harvesting the usable fuel fractions from the algae mass and effectively isolating and separating the usable components into specific fractions, and converting isolated fractions into green chemicals.

Influence of Algae Age and Population on the Response to TiO2 Nanoparticles

Directory of Open Access Journals (Sweden)

David M. Metzler

2018-03-01

Full Text Available This work shows the influence of algae age (at the time of the exposure and the initial algae population on the response of green algae Raphidocelis subcapitata to titanium dioxide nanoparticles (TiO2 NPs. The different algae age was obtained by changes in flow rate of continually stirred tank reactors prior to NP exposure. Increased algae age led to a decreased growth, variations in chlorophyll content, and an increased lipid peroxidation. Increased initial algae population (0.3−4.2 × 106 cells/mL at a constant NP concentration (100 mg/L caused a decline in the growth of algae. With increased initial algae population, the lipid peroxidation and chlorophyll both initially decreased and then increased. Lipid peroxidation had 4× the amount of the control at high and low initial population but, at mid-ranged initial population, had approximately half the control value. Chlorophyll a results also showed a similar trend. These results indicate that the physiological state of the algae is important for the toxicological effect of TiO2 NPs. The condition of algae and exposure regime must be considered in detail when assessing the toxicological response of NPs to algae.

Influence of Algae Age and Population on the Response to TiO2 Nanoparticles

Science.gov (United States)

Metzler, David M.; Erdem, Ayca; Huang, Chin Pao

2018-01-01

This work shows the influence of algae age (at the time of the exposure) and the initial algae population on the response of green algae Raphidocelis subcapitata to titanium dioxide nanoparticles (TiO2 NPs). The different algae age was obtained by changes in flow rate of continually stirred tank reactors prior to NP exposure. Increased algae age led to a decreased growth, variations in chlorophyll content, and an increased lipid peroxidation. Increased initial algae population (0.3−4.2 × 106 cells/mL) at a constant NP concentration (100 mg/L) caused a decline in the growth of algae. With increased initial algae population, the lipid peroxidation and chlorophyll both initially decreased and then increased. Lipid peroxidation had 4× the amount of the control at high and low initial population but, at mid-ranged initial population, had approximately half the control value. Chlorophyll a results also showed a similar trend. These results indicate that the physiological state of the algae is important for the toxicological effect of TiO2 NPs. The condition of algae and exposure regime must be considered in detail when assessing the toxicological response of NPs to algae. PMID:29587381

WASP7 BENTHIC ALGAE - MODEL THEORY AND USER'S GUIDE

Science.gov (United States)

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...

An Artificial Neural Network Based Short-term Dynamic Prediction of Algae Bloom

Directory of Open Access Journals (Sweden)

Yao Junyang

2014-06-01

Full Text Available This paper proposes a method of short-term prediction of algae bloom based on artificial neural network. Firstly, principal component analysis is applied to water environmental factors in algae bloom raceway ponds to get main factors that influence the formation of algae blooms. Then, a model of short-term dynamic prediction based on neural network is built with the current chlorophyll_a values as input and the chlorophyll_a values in the next moment as output to realize short-term dynamic prediction of algae bloom. Simulation results show that the model can realize short-term prediction of algae bloom effectively.

Cyanobacteria and Cyanotoxins: From Impacts on Aquatic Ecosystems and Human Health to Anticarcinogenic Effects

Science.gov (United States)

Zanchett, Giliane; Oliveira-Filho, Eduardo C.

2013-01-01

Cyanobacteria or blue-green algae are among the pioneer organisms of planet Earth. They developed an efficient photosynthetic capacity and played a significant role in the evolution of the early atmosphere. Essential for the development and evolution of species, they proliferate easily in aquatic environments, primarily due to human activities. Eutrophic environments are conducive to the appearance of cyanobacterial blooms that not only affect water quality, but also produce highly toxic metabolites. Poisoning and serious chronic effects in humans, such as cancer, have been described. On the other hand, many cyanobacterial genera have been studied for their toxins with anticancer potential in human cell lines, generating promising results for future research toward controlling human adenocarcinomas. This review presents the knowledge that has evolved on the topic of toxins produced by cyanobacteria, ranging from their negative impacts to their benefits. PMID:24152991

Cyanobacteria and Cyanotoxins: From Impacts on Aquatic Ecosystems and Human Health to Anticarcinogenic Effects

Directory of Open Access Journals (Sweden)

Giliane Zanchett

2013-10-01

Full Text Available Cyanobacteria or blue-green algae are among the pioneer organisms of planet Earth. They developed an efficient photosynthetic capacity and played a significant role in the evolution of the early atmosphere. Essential for the development and evolution of species, they proliferate easily in aquatic environments, primarily due to human activities. Eutrophic environments are conducive to the appearance of cyanobacterial blooms that not only affect water quality, but also produce highly toxic metabolites. Poisoning and serious chronic effects in humans, such as cancer, have been described. On the other hand, many cyanobacterial genera have been studied for their toxins with anticancer potential in human cell lines, generating promising results for future research toward controlling human adenocarcinomas. This review presents the knowledge that has evolved on the topic of toxins produced by cyanobacteria, ranging from their negative impacts to their benefits.

Cyanobacteria and cyanotoxins: from impacts on aquatic ecosystems and human health to anticarcinogenic effects.

Science.gov (United States)

Zanchett, Giliane; Oliveira-Filho, Eduardo C

2013-10-23

Cyanobacteria or blue-green algae are among the pioneer organisms of planet Earth. They developed an efficient photosynthetic capacity and played a significant role in the evolution of the early atmosphere. Essential for the development and evolution of species, they proliferate easily in aquatic environments, primarily due to human activities. Eutrophic environments are conducive to the appearance of cyanobacterial blooms that not only affect water quality, but also produce highly toxic metabolites. Poisoning and serious chronic effects in humans, such as cancer, have been described. On the other hand, many cyanobacterial genera have been studied for their toxins with anticancer potential in human cell lines, generating promising results for future research toward controlling human adenocarcinomas. This review presents the knowledge that has evolved on the topic of toxins produced by cyanobacteria, ranging from their negative impacts to their benefits.

Bacterial community changes in an industrial algae production system.

Science.gov (United States)

Fulbright, Scott P; Robbins-Pianka, Adam; Berg-Lyons, Donna; Knight, Rob; Reardon, Kenneth F; Chisholm, Stephen T

2018-04-01

While microalgae are a promising feedstock for production of fuels and other chemicals, a challenge for the algal bioproducts industry is obtaining consistent, robust algae growth. Algal cultures include complex bacterial communities and can be difficult to manage because specific bacteria can promote or reduce algae growth. To overcome bacterial contamination, algae growers may use closed photobioreactors designed to reduce the number of contaminant organisms. Even with closed systems, bacteria are known to enter and cohabitate, but little is known about these communities. Therefore, the richness, structure, and composition of bacterial communities were characterized in closed photobioreactor cultivations of Nannochloropsis salina in F/2 medium at different scales, across nine months spanning late summer-early spring, and during a sequence of serially inoculated cultivations. Using 16S rRNA sequence data from 275 samples, bacterial communities in small, medium, and large cultures were shown to be significantly different. Larger systems contained richer bacterial communities compared to smaller systems. Relationships between bacterial communities and algae growth were complex. On one hand, blooms of a specific bacterial type were observed in three abnormal, poorly performing replicate cultivations, while on the other, notable changes in the bacterial community structures were observed in a series of serial large-scale batch cultivations that had similar growth rates. Bacteria common to the majority of samples were identified, including a single OTU within the class Saprospirae that was found in all samples. This study contributes important information for crop protection in algae systems, and demonstrates the complex ecosystems that need to be understood for consistent, successful industrial algae cultivation. This is the first study to profile bacterial communities during the scale-up process of industrial algae systems.

Serpins in plants and green algae

DEFF Research Database (Denmark)

Roberts, Thomas Hugh; Hejgaard, Jørn

2008-01-01

. Serpins have been found in diverse species of the plant kingdom and represent a distinct clade among serpins in multicellular organisms. Serpins are also found in green algae, but the evolutionary relationship between these serpins and those of plants remains unknown. Plant serpins are potent inhibitors...... of mammalian serine proteinases of the chymotrypsin family in vitro but, intriguingly, plants and green algae lack endogenous members of this proteinase family, the most common targets for animal serpins. An Arabidopsis serpin with a conserved reactive centre is now known to be capable of inhibiting...

P-32 uptake in lentic algae

International Nuclear Information System (INIS)

Strange, J.R.; Williamson, G.D.; Fletcher, D.J.

1975-01-01

A study of the Flat Creek Embayment of Lake Sidney Lanier near Gainesville, Georgia revealed three genera of algae, Chlorococcum, Fragillaria and Nostoc, to be prominent in this eutrophic region of the lake. The algae was grown in phosphate-rich media and subsequently labelled with P-32. All species incorporated luxury amounts of phosphorus as determined by the uptake of P-32. The results indicate that the P-32 uptake is proportional to the surface-per-volume ratio. The higher surface-per-volume ratio resulted in greater uptake of P-32

Algas: cosmética y salud

OpenAIRE

Arenas, Patricia Marta; Guayta, Silvina L.

1998-01-01

El uso de las algas con fines estéticos y terapéuticos tiene su origen en tiempos muy antiguos. El auge de la utilización de “productos naturales” ha llevado a sobrevalorar las propiedades de los vegetales en general y de las algas en particular. Por tal razón, las mismas gozan de un elevado prestigio, incluso cuando las propiedades reales son en gran medida superadas por las popularmente atribuidas. De allí que surja la necesidad de abordar estudios interdisciplinarios y de naturaleza aplica...

Levels of some Trace Metals in Macroalgae from the Red Sea in Egypt

International Nuclear Information System (INIS)

Aboul-Naga, Wafiqa Mohamed

2005-01-01

The concentrations of iron (Fe), Zinc (Zn), manganese (Mn), Copper (Cu), chromium (Cr), nickel (Ni), and cobalt (Co) in ten macroalgae species from the Red Sea coastal water varied widely and also the trend of abundance of each metal also differed from one group to another. Concentration factors varied among species for iron (Fe) copper (Cu) manganese (Mn), but with iron (Fe) showing generally high concentration factors. Highly significant (P<0.05) relationships were found between manganese (Mn) and Nickel (Ni), and, Zinc (Zn) and copper (Cu). Moreover, moderate correlations were observed between manganese (Mn) and iron (Fe) and chromium (Cr), indicating that manganese (Mn) is the most accumulated metal in the macro algae of the Red Sea. In spite of the level of trace metals in the macro algae of the Red Sea. In spite of the level of trace metals in the macro algae, dominance is moderate relative to other sea areas subjected to intensive pollution. That is, the results indicated a nonpolluted environment. (author)

Algae Production from Wastewater Resources: An Engineering and Cost Analysis

Energy Technology Data Exchange (ETDEWEB)

Schoenung, Susan [Longitude 122 West, Inc.; Efroymson, Rebecca Ann [ORNL

2018-03-01

Co-locating algae cultivation ponds near municipal wastewater (MWW) facilities provides the opportunity to make use of the nitrogen and phosphorus compounds in the wastewater as nutrient sources for the algae. This use benefits MWW facilities, the algae biomass and biofuel or bioproduct industry, and the users of streams where treated or untreated waste would be discharged. Nutrient compounds can lead to eutrophication, hypoxia, and adverse effects to some organisms if released downstream. This analysis presents an estimate of the cost savings made possible to cultivation facilities by using the nutrients from wastewater for algae growth rather than purchase of the nutrients. The analysis takes into consideration the cost of pipe transport from the wastewater facility to the algae ponds, a cost factor that has not been publicly documented in the past. The results show that the savings in nutrient costs can support a wastewater transport distance up to 10 miles for a 1000-acre-pond facility, with potential adjustments for different operating assumptions.

Metagenomic Sequencing of Marine Periphyton: Taxonomic and Functional Insights into Biofilm Communities

Directory of Open Access Journals (Sweden)

Kemal eSanli

2015-10-01

Full Text Available Periphyton communities are complex phototrophic, multispecies biofilms that develop on surfaces in aquatic environments. These communities harbor a large diversity of organisms comprising viruses, bacteria, algae, fungi, protozoans and metazoans. However, thus far the total biodiversity of periphyton has not been described. In this study, we use metagenomics to characterize periphyton communities from the marine environment of the Swedish west coast. Although we found approximately ten times more eukaryotic rRNA marker gene sequences compared to prokaryotic, the whole metagenome-based similarity searches showed that bacteria constitute the most abundant phyla in these biofilms. We show that marine periphyton encompass a range of heterotrophic and phototrophic organisms. Heterotrophic bacteria, including the majority of proteobacterial clades and Bacteroidetes, and eukaryotic macro-invertebrates were found to dominate periphyton. The phototrophic groups comprise Cyanobacteria and the alpha-proteobacterial genus Roseobacter, followed by different micro- and macro-algae. We also assess the metabolic pathways that predispose these communities to an attached lifestyle. Functional indicators of the biofilm form of life in periphyton involve genes coding for enzymes that catalyze the production and degradation of extracellular polymeric substances, mainly in the form of complex sugars such as starch and glycogen-like meshes together with chitin. Genes for 278 different transporter proteins were detected in the metagenome, constituting the most abundant protein complexes. Finally, genes encoding enzymes that participate in anaerobic pathways, such as denitrification and methanogenesis, were detected suggesting the presence of anaerobic or low-oxygen micro-zones within the biofilms.

Preparation of desiccation-resistant aquatic-living Nostoc flagelliforme (Cyanophyceae) for potential ecological application

Science.gov (United States)

Gao, Xiang; Yang, Yi-Wen; Cui, Li-Juan; Zhou, De-Bao; Qiu, Bao-Sheng

2015-01-01

Nostoc flagelliforme is a terrestrial edible cyanobacterium that grows in arid and semi-arid steppes. The continued over-exploitation in the last century has led to a sharp decline of this resource and a severe deterioration of the steppe ecology. Liquid-cultured N. flagelliforme serves as promising algal ‘seeds’ for resource restoration. In this study, macroscopic (or visible) aquatic-living colonies (MaACs) of N. flagelliforme were developed under weak light and high nitrogen conditions. In a 24 day shake-flask culture, MaACs were propagated by about 4.5-fold in biomass without loss of their macro-morphology; at the same time, the addition of weak UV-B treatment resulted in slightly bigger MaACs. Polyvinylpyrrolidone (PVP) k30, a water-soluble polymer, was used to generate the coating around MaACs, and after full desiccation, the coated MaACs could recover their photosynthetic physiological activity when rehydrated, with 4% PVP k30 for coating being most effective. In contrast, PVP k30-coated microscopic aquatic-living colonies of N. flagelliforme and non-coated MaACs showed no resistance to full desiccation. The macroscopic morphology or structure of MaACs should be crucial for the formation of protection by PVP k30 coating. PVP k30-coated MaACs were more approaching to actual application for resource restoration. PMID:25847617

El debate micro-macro: dilemas y contextos

Directory of Open Access Journals (Sweden)

Vania Salles

2001-06-01

Full Text Available This paper discusses the general terms of the sociological debate on the micro macro question. Not only the main trends organizing the debate are examined, but also some ways to solve the dichotomies present in some proposals. It is held that contemporary theoretical practice produces —after the classics and with different focuses— a reflexivecorpus and research practices rooted in the blurring of the micro macro as polar questions, by the way of offering integrating proposals and overcoming reducing positions.

Toxic effects of some major polyaromatic hydrocarbons found in crude oil and aquatic sediments on Scenedesmus subspicatus

Energy Technology Data Exchange (ETDEWEB)

Djomo, J.E. [Universite de Dschang Cameroun, Toulouse (France). Laboratoire de Biologie Animale; Dauta, A. [Universite Paul Sabatier, Toulouse (France). CESAC; Ferrier, V. [UMR-CNRS 9925 affiliee a l' INSERM, Toulouse (France); Narbonne, J.F. [Universite de Bordeaux I, Talence (France). Laboratoire de Toxicologie Alimentaire; Monkiedje, A.; Njine, T. [Universite de Yaounde 1, Cameroun, Toulouse (France). Laboratoire de Biologie et Physiologie Animales; Garrigues, P. [Universite de Bordeaux I, Talence (France). UPRES A 5472 CNRS

2004-04-01

The green alga, Scenedesmus subspicatus was exposed for 7 days to a series of PAHs (polyaromatic hydrocarbons) of increased molecular weight from two to five rings [naphthalene (Nap), anthracene (Ant), phenanthrene (Phe), pyrene (Pyr) and benzo(a)pyrene (BaP)]. The toxicity measured as population growth inhibition by individual PAH to the S. subspicatus followed the order: BaP>Pyr>Ant>Phe>Nap. These results confirmed that the toxicity potential of PAHs seems to be strongly influenced by their physico-chemical properties (aqueous solubility, K{sub ow}, coefficient of volatilization, etc.) and the conditions of algae culture (light, presence of nitrate ions, etc.). Consequently, Nap, Phe and Ant having low K{sub ow} values and low coefficient of volatilization values were less toxic than BaP with the highest k{sub ow} value, indicating for example why Nap with the lowest EC{sub 50} value was nearly 2x10{sup 5} times lower than that of BaP. Moreover, nitrate ions seemed to act directly on the degree of hydroxylated radical reactivity of PAHs, since BaP always remained the most toxic of the compounds tested. The results were also agreed with the QSAR model for toxicity prediction of PAHs to many aquatic organisms. (author)

Influence of Algae Age and Population on the Response to TiO2 Nanoparticles

OpenAIRE

David M. Metzler; Ayca Erdem; Chin Pao Huang

2018-01-01

This work shows the influence of algae age (at the time of the exposure) and the initial algae population on the response of green algae Raphidocelis subcapitata to titanium dioxide nanoparticles (TiO2 NPs). The different algae age was obtained by changes in flow rate of continually stirred tank reactors prior to NP exposure. Increased algae age led to a decreased growth, variations in chlorophyll content, and an increased lipid peroxidation. Increased initial algae population (0.3−4.2 × 106 ...

A zwitterionic macro-crosslinker for durable non-fouling coatings.

Science.gov (United States)

Wang, Wei; Lu, Yang; Xie, Jinbing; Zhu, Hui; Cao, Zhiqiang

2016-03-28

A novel zwitterionic macro-crosslinker was developed and applied to fabricate durable non-fouling coatings on a polyurethane substrate. The zwitterionic macro-crosslinker coating exhibited superior durability over the traditional brush polymer coating and was able to retain its non-fouling property even after weeks of shearing in flowing liquid.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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

Life cycle assessment of biofuels from an integrated Brazilian algae-sugarcane biorefinery

International Nuclear Information System (INIS)

Souza, Simone P.; Gopal, Anand R.; Seabra, Joaquim E.A.

2015-01-01

Sugarcane ethanol biorefineries in Brazil produce carbon dioxide, electricity and heat as byproducts. These are essential inputs for algae biodiesel production. In this paper, we assessed ethanol's life cycle greenhouse gas emissions and fossil energy use produced in an integrated sugarcane and algae biorefinery where biodiesel replaces petroleum diesel for all agricultural operations. Carbon dioxide from cane juice fermentation is used as the carbon source for algae cultivation, and sugarcane bagasse is the sole source of energy for the entire facility. Glycerin produced from the biodiesel plant is consumed by algae during the mixotrophic growth phase. We assessed the uncertainties through a detailed Monte-Carlo analysis. We found that this integrated system can improve both the life cycle greenhouse gas emissions and the fossil energy use of sugarcane ethanol by around 10% and 50%, respectively, compared to a traditional Brazilian sugarcane ethanol distillery. - Highlights: • A high diesel consumption is associated to the ethanol sugarcane life-cycle. • Sugarcane industry can provide sources of carbon and energy for the algae growing. • The sugarcane-algae integration can improve the ethanol life-cycle performance. • This integration is a promising pathway for the deployment of algae biodiesel. • There are still significant techno-economic barriers associated with algae biodiesel

Macro-Finance Determinants of the Long-Run Stock-Bond Correlation

DEFF Research Database (Denmark)

Asgharian, Hossein; Christiansen, Charlotte; Hou, Ai Jun

itself. Macro-finance variables and the lagged realized correlation are simultaneously significant in forecasting the long-run stock-bond correlation. The behavior of the long-run stock-bond correlation is very different when estimated taking the macro-finance variables into account. Supporting......We investigate the long-run stock-bond correlation using a novel model that combines the dynamic conditional correlation model with the mixed-data sampling approach. The long-run correlation is affected by both macro-finance variables (historical and forecasts) and the lagged realized correlation...

Concentration factors for Cs-137 in marine algae from Japanese coastal waters

International Nuclear Information System (INIS)

Tateda, Yutaka; Koyanagi, Taku.

1994-01-01

Concentration factors (CF: Bq·kg -1 in wet algae/Bq·kg -1 in filtered seawater) for Cs-137 in Japanese coastal algae, were investigated during 1984-1990. Cs-137/Cs (stable) atom ratios were also examined to clarify the distribution equilibrium of Cs-137 in marine algae and sea water. The CFs in marine algae were within the range of 5.4-92, and the geometric mean of CF was 28±2 (standard error) in Japanese coastal species. The CFs in edible species were within the range of 5.4-67, and the geometric means of CF was 26±4 (standard error). The values of Cs-137/Cs atom ratios in marine algae and sea water indicated that Cs-137 reached an equilibrium state in partition between algae and sea water. Therefore, the CF value obtained in the present study can be regarded as an equilibrated value. Our results showed that hte CF for Cs-137 in Japanese coastal algae were consistent with the Japanese guideline CFs, but were smaller than the recommended value by IAEA. (author)

Rare species of fungi parasiting on algae. III.

OpenAIRE

Joanna Z. Kadłubowska

2014-01-01

The investigations csrried out on algae revealed the following species of fungi from the order of Chytridialis Hawksworth et al. (1995) parasitizing on algae: Rhizophydium subgulosum, R. ganlosporum, R. planctonicum, Entophlyctis rhizina and Harpochytrium hedinii. These species arc new to Poland. The figure of resting spore of Entophlyctis rhizina is the fint graphic documentation of this species.

The role of algae in agriculture: a mathematical study.

Science.gov (United States)

Tiwari, P K; Misra, A K; Venturino, Ezio

2017-06-01

Synthetic fertilizers and livestock manure are nowadays widely used in agriculture to improve crop yield but nitrogen and phosphorous runoff resulting from their use compromises water quality and contributes to eutrophication phenomena in waterbeds within the countryside and ultimately in the ocean. Alternatively, algae could play an important role in agriculture where they can be used as biofertilizers and soil stabilizers. To examine the possible reuse of the detritus generated by dead algae as fertilizer for crops, we develop three mathematical models building upon each other. A system is proposed in which algae recover waste nutrients (nitrogen and phosphorus) for reuse in agricultural production. The results of our study show that in so doing, the crop yield may be increased and simultaneously the density of algae in the lake may be reduced. This could be a way to mitigate and possibly solve the environmental and economic issues nowadays facing agriculture.

Nano/macro porous bioactive glass scaffold

Science.gov (United States)

Wang, Shaojie

Bioactive glass (BG) and ceramics have been widely studied and developed as implants to replace hard tissues of the musculo-skeletal system, such as bones and teeth. Recently, instead of using bulk materials, which usually do not degrade rapidly enough and may remain in the human body for a long time, the idea of bioscaffold for tissue regeneration has generated much interest. An ideal bioscaffold is a porous material that would not only provide a three-dimensional structure for the regeneration of natural tissue, but also degrade gradually and, eventually be replaced by the natural tissue completely. Among various material choices the nano-macro dual porous BG appears as the most promising candidate for bioscaffold applications. Here macropores facilitate tissue growth while nanopores control degradation and enhance cell response. The surface area, which controls the degradation of scaffold can also be tuned by changing the nanopore size. However, fabrication of such 3D structure with desirable nano and macro pores has remained challenging. In this dissertation, sol-gel process combined with spinodal decomposition or polymer sponge replication method has been developed to fabricate the nano-macro porous BG scaffolds. Macropores up to 100microm are created by freezing polymer induced spinodal structure through sol-gel transition, while larger macropores (>200um) of predetermined size are obtained by the polymer sponge replication technique. The size of nanopores, which are inherent to the sol-gel method of glass fabrication, has been tailored using several approaches: Before gel point, small nanopores are generated using acid catalyst that leads to weakly-branched polymer-like network. On the other hand, larger nanopores are created with the base-catalyzed gel with highly-branched cluster-like structure. After the gel point, the nanostructure can be further modified by manipulating the sintering temperature and/or the ammonia concentration used in the solvent

Algae: America's Pathway to Independence

National Research Council Canada - National Science Library

Custer, James

2007-01-01

.... Oil dependency is an unacceptable risk to U.S. national strategy. This paper advocates independence from foreign oil by converting the national transportation fleet to biodiesel derived from algae...

Role of algae in water quality regulation in NPP water reservoirs

International Nuclear Information System (INIS)

Klenus, V.G.; Kuz'menko, M.I.; Nasvit, O.I.

1985-01-01

Investigations, carried out in Chernobyl NPP water reservoir, show that sewage water inflow, being not sufficiently purified, enriched by mineral and organic substances, is accompanied by a considerable increase of algae productivity. The algae play a determining role in accumulation of radionuclides and their transformation into bottom depositions. Comparative investigation of accumulation intensity in alga cells 12 C and 14 C gives evidence that the rate of radioactive nuclide inclusions is practically adequate to the rate of inclusions of their stable analogues. Bacterial destruction of organic contaminations occurs more intensively under aerobic conditions, which are mainly provided due to photosynthetizing activity of algae

Characteristics of Red Algae Bioplastics/Latex Blends under Tension

Directory of Open Access Journals (Sweden)

M. Nizar Machmud

2013-10-01

Full Text Available Cassava, corn, sago and the other food crops have been commonly used as raw materials to produce green plastics. However, plastics produced from such crops cannot be tailored to fit a particular requirement due to their poor water resistance and mechanical properties. Nowadays, researchers are hence looking to get alternative raw materials from the other sustainable resources to produce plastics. Their recent published studies have reported that marine red algae, that has been already widely used as a raw material for producing biofuels, is one of the potential algae crops that can be turned into plastics. In this work, Eucheuma Cottonii, that is one of the red alga crops, was used as raw material to produce plastics by using a filtration technique. Selected latex of Artocarpus altilis and Calostropis gigantea was separately then blended with bioplastics derived from the red algae, to replace use of glycerol as plasticizer. Role of the glycerol and the selected latex on physical and mechanical properties of the red algae bioplastics obtained under a tensile test performed at room temperature are discussed. Tensile strength of some starch-based plastics collected from some recent references is also presented in this paperDoi: 10.12777/ijse.5.2.81-88 [How to cite this article: Machmud, M.N., Fahmi, R.,  Abdullah, R., and Kokarkin, C.  (2013. Characteristics of Red Algae Bioplastics/Latex Blends under Tension. International Journal of Science and Engineering, 5(2,81-88. Doi: 10.12777/ijse.5.2.81-88

Macro-Finance Determinants of the Long-Run Stock-Bond Correlation

DEFF Research Database (Denmark)

Asgharian, Hossein; Christiansen, Charlotte; Hou, Ai Jun

2016-01-01

We investigate long-run stock–bond correlation using a model that combines the dynamic conditional correlation model with the mixed-data sampling approach and allows long-run correlation to be affected by macro-finance factors (historical and forecasts). We use macro-finance factors related...... to inflation and interest rates, illiquidity, state of the economy, and market uncertainty. Macro-finance factors, particularly their forecasts, are good at forecasting long-run stock–bond correlation. Supporting the flight-to-quality phenomenon, long-run correlation tends to be small and negative when...

Time and Space Complexity of Inside-Out Macro Grammars

NARCIS (Netherlands)

Asveld, P.R.J.

1980-01-01

Starting form Fischer's IO Standard Form Theorem we show that for each inside-out (or IO-) macro language $L$ there exists a $\\lambda$-free IO macro grammar with the following property: for each $x$ in $L$ there is a derivation of $x$ of length at most linear in the length of $x$. Then we construct

Chemical and radioactivity study of sea alga distribution along the Syrian coast

International Nuclear Information System (INIS)

Al-Masri, M. S.; Mamish, S.; Budeir, Y.

2001-11-01

Three types of sea alga distributed along the Syrian coast have been studied from the chemical and radioactivity point of view. Results have shown the metals that red alga contains the highest levels of Ca and Mg while brown alga were found to contain relatively high concentrations of other elements and non metals such as Cl, I and Br. In addition, 137 Cs concentrations in all the analyzed sample were low while the levels of naturally occurring radionuclides such as 210 Po, 210 Pb and radium isotopes were found to be high in red alga which indicates their selectivity to these isotopes. On the other hand, brown alga and especially Cysteseira has shown a clear selectivity for some trace elements such as As, Cr, Cd, Cu and Co, this selectivity may encourage the use of brown alga as biological indicator for trace elements pollution. (author)

Sustainable Algae Biodiesel Production in Cold Climates

OpenAIRE

Baliga, Rudras; Powers, Susan E.

2010-01-01

This life cycle assessment aims to determine the most suitable operating conditions for algae biodiesel production in cold climates to minimize energy consumption and environmental impacts. Two hypothetical photobioreactor algae production and biodiesel plants located in Upstate New York (USA) are modeled. The photobioreactor is assumed to be housed within a greenhouse that is located adjacent to a fossil fuel or biomass power plant that can supply waste heat and flue gas containing CO2 as a ...

Photobiological hydrogen production with switchable photosystem-II designer algae

Science.gov (United States)

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.

Energy Productivity of the High Velocity Algae Raceway Integrated Design (ARID-HV)

Energy Technology Data Exchange (ETDEWEB)

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.

Bisphenol A in the aquatic environment and its endocrine-disruptive effects on aquatic organisms.

Science.gov (United States)

Kang, Jeong-Hun; Asai, Daisuke; Aasi, Daisuke; Katayama, Yoshiki

2007-01-01

Bisphenol A [BPA; 2,2-bis(4-hydroxyphenyl)propane], which is mainly used in the production of epoxy resins and polycarbonate plastics, is a known endocrine disruptor and is acutely toxic to aquatic organisms. Due to intensified usage of these products, exposure of organisms to BPA via several routes, such as the environment and food, has increased. The aquatic environment is an important area for the study of BPA. This report reviews the literature concerning contamination routes and degradation of BPA in the aquatic environment and its endocrine-disruptive effects on aquatic organisms.

Algae biotechnology: products and processes

National Research Council Canada - National Science Library

Bux, F; Chisti, Yusuf

2016-01-01

This book examines the utilization of algae for the development of useful products and processes with the emphasis towards green technologies and processes, and the requirements to make these viable...

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

Directory of Open Access Journals (Sweden)